Many simply don't have the kind of brains wired for precision marching and crisp solutes.
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AQP1 is thus a selective filter for small polar solutes, whereas GlpF is highly permeable to small solutes and less permeable to larger solutes.
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The earliest solutes, Coleicarpus and Castericystis, lived during the Drumian age of the Cambrian. Solutes were the last of the four carpoid classes to appear in the fossil record. Solutes appear to have evolved in Laurentia, but became more widespread during the Ordovician.
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Receptor- mediated endocytosis is a form of pinocytosis where a cell takes in specific molecules or solutes. Proteins with receptor sites are located on the plasma membrane, binding to specific solutes. The receptor proteins that are attached to the specific solutes go inside coated pits, forming a vesicle. The vesicles then surround the receptors that are attached to the specific solutes, releasing their molecules.
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Penetrating solutes can diffuse through the cell membrane, causing momentary changes in cell volume as the solutes "pull" water molecules with them. Non-penetrating solutes cannot cross the cell membrane; therefore, the movement of water across the cell membrane (i.e., osmosis) must occur for the solutions to reach equilibrium. A solution can be both hyperosmotic and isotonic.
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These properties are colligative in systems where the solute is essentially confined to the liquid phase. Boiling point elevation (like vapour pressure lowering) is colligative for non-volatile solutes where the solute presence in the gas phase is negligible. Freezing point depression is colligative for most solutes since very few solutes dissolve appreciably in solid solvents.
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Some solutes such as noble gases can be extracted from one phase to another without the need for a chemical reaction (see absorption). This is the simplest type of solvent extraction. When a solvent is extracted, two immiscible liquids are shaken together. The more polar solutes dissolve preferentially in the more polar solvent, and the less polar solutes in the less polar solvent.
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Transport proteins that pump solutes into the cell can be regulated by cell turgor pressure. Lower values allow for an increase in the pumping of solutes; which in turn increases osmotic pressure. This function is important as a plant response when under drought conditions (seeing as turgor pressure is maintained), and for cells which need to accumulate solutes (i.e. developing fruits).
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Phloem loading is the process of loading carbon into the phloem for transport to different 'sinks' in a plant. Sinks include metabolism, growth, storage, and other processes or organs that need carbon solutes to persist. It can be a passive process, relying on a pressure gradient to generate diffusion of solutes through the symplast, or an active process, requiring energy to create membrane-bound transporter proteins that move solutes through the apoplast against a gradient. Passive phloem loading transports solutes freely through plasmodesma in the symplast of the minor veins of leaves.
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Concentrations of solutes in subglacial lakes, including major ions and nutrients like sodium, sulfate, and carbonates, are low compared to typical surface lakes. These solutes enter the water column from glacial ice melting and from sediment weathering. Despite their low solute concentrations, the large volume of subglacial waters make them important contributors of solutes, particularly iron, to their surrounding oceans. Subglacial outflow from the Antarctic Ice Sheet, including outflow from subglacial lakes, is estimated to add a similar amount of solutes to the Southern Ocean as some of the world's largest rivers.
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Its main function is as a barrier to movement of water and solutes.
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As such, larger numbers indicate a greater concentration of solutes in the plasma.
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Dissolved stream solutes can be considered either reactive or conservative. Reactive solutes are readily biologically assimilated by the autotrophic and heterotrophic biota of the stream; examples can include inorganic nitrogen species such as nitrate or ammonium, some forms of phosphorus (e.g., soluble reactive phosphorus), and silica. Other solutes can be considered conservative, which indicates that the solute is not taken up and used biologically; chloride is often considered a conservative solute.
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Chemical erosion is the loss of matter in a landscape in the form of solutes. Chemical erosion is usually calculated from the solutes found in streams. Anders Rapp pioneered the study of chemical erosion in his work about Kärkevagge published in 1960.
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With other solvents and solutes, varying steric and kinetic factors can also affect the solvation shell.
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Solutes, both small and large, get dragged through the membrane at a similar rate by the flow of water that has been engendered by the hydrostatic pressure. Thus convection overcomes the reduced removal rate of larger solutes (due to their slow speed of diffusion) seen in hemodialysis.
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Both of these solutes are disaccharide heterosides which are extremely rare in thermophiles. Both are important in osmotic adaptation in microbes as well. With many questions to be answered about these two solutes, further research could benefit biotechnology in application to production of things such as food preservatives and textiles. Also, for scientists who are looking to further answer why and how hyperthermophiles survive, these two solutes could help fill in the missing pieces of the puzzle.
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H-bond donor ability is classified on a scale (α). Protic solvents can solvate solutes that can accept hydrogen bonds. Similarly, solvents that can accept a hydrogen bond can solvate H-bond-donating solutes. The hydrogen bond acceptor ability of a solvent is classified on a scale (β).
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This allows the plant to select the solutes that pass further into the plant. It thus forms an important barrier to harmful solutes. For example, mangroves use suberin to minimize salt intake from their littoral habitat. Suberin is found in the phellem layer of the periderm (or cork).
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If it does, the creatinine level is often normal. The toxins show various cytotoxic activities in the serum and have different molecular weights, and some of them are bound to other proteins, primarily to albumin. Uremic toxins are classified into three groups as small water-soluble solutes, middle molecular- weight solutes, and protein-bound solutes. Hemodialysis with high-flux dialysis membrane, long or frequent treatment, and increased blood/dialysate flow has improved removal of water-soluble small molecular weight uremic toxins.
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Osmolarity and tonicity are related but distinct concepts. Thus, the terms ending in -osmotic (isosmotic, hyperosmotic, hyposmotic) are not synonymous with the terms ending in -tonic (isotonic, hypertonic, hypotonic). The terms are related in that they both compare the solute concentrations of two solutions separated by a membrane. The terms are different because osmolarity takes into account the total concentration of penetrating solutes and non-penetrating solutes, whereas tonicity takes into account the total concentration of non- freely penetrating solutes only.
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At the beginning of the run, a mixture of solutes to be separated is applied to the column, under conditions selected to promote high retention. The higher-affinity solutes are preferentially retained near the head of the column, with the lower-affinity solutes moving farther downstream. The fastest moving component begins to form a pure zone downstream. The other components also begin to form zones, but the continued supply of the mixed feed at head of the column prevents full resolution.
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The salinity in the lake gradually builds up through years as water evaporates and leaves its solutes behind.
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Tight junctions present in different types of epithelia are selective for solutes of differing size, charge, and polarity.
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Artery walls are analogous to a selectively permeable membrane, and they allow solutes, including sodium and chloride, to pass through (or not), depending on osmosis. Circulating water and solutes in the body maintain blood pressure in the blood, as well as other functions such as regulation of body temperature. When salt is ingested, it is dissolved in the blood as two separate ions – Na+ and Cl−. The water potential in blood will decrease due to the increase solutes, and blood osmotic pressure will increase.
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Additionally, osmoprotectants provide a method to regulate gene expression in response to environmental osmolarity. The presence of compatible solutes even in small concentrations has been shown to affect gene expression. Their effects range from inducing production of more compatible solutes to regulating components involved in infection, such as phospholipase C in Pseudomonas aeruginosa.
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Most solutes were free-living, but the basal solutan Coleicarpus used its homoiostele as a holdfast, as did juvenile Castericystis.
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Thus, the glomerular filtrate becomes more concentrated, which is one of the steps in forming urine. Reabsorption allows many useful solutes (primarily glucose and amino acids), salts and water that have passed through Bowman's capsule, to return to the circulation. These solutes are reabsorbed isotonically, in that the osmotic potential of the fluid leaving the proximal convoluted tubule is the same as that of the initial glomerular filtrate. However, glucose, amino acids, inorganic phosphate, and some other solutes are reabsorbed via secondary active transport through cotransport channels driven by the sodium gradient.
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Found in vertebrate epithelia, tight junctions act as barriers that regulate the movement of water and solutes between epithelial layers. Tight junctions are classified as a paracellular barrier which is defined as not having directional discrimination; however, movement of the solute is largely dependent upon size and charge. There is evidence to suggest that the structures in which solutes pass through are somewhat like pores. Physiological pH plays a part in the selectivity of solutes passing through tight junctions with most tight junctions being slightly selective for cations.
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At room temperature, intergranular fracture is commonly associated with altered cohesion resulting from segregation of solutes or impurities at the grain boundaries. Examples of solutes known to influence intergranular fracture are sulfur, phosphorus, arsenic, and antimony specifically in steels, lead in aluminum alloys, and hydrogen in numerous structural alloys. At high impurity levels, especially in the case of hydrogen embrittlement, the likelihood of intergranular fracture is greater. Solutes like hydrogen are hypothesized to stabilize and increase the density of strain-induced vacancies, leading to microcracks and microvoids at grain boundaries.
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Transport of soil solutes is termed leaching. Soluble constituents are deposited due to differences in soil chemistry, especially soil pH and redox potential.
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This latter equation is named after him. Using these equations one can calculate the molar mass of solutes from the osmotic pressure data.
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Another related process is zone remelting, in which two solutes are distributed through a pure metal. This is important in the manufacture of semiconductors, where two solutes of opposite conductivity type are used. For example, in germanium, pentavalent elements of group V such as antimony and arsenic produce negative (n-type) conduction and the trivalent elements of group III such as aluminum and boron produce positive (p-type) conduction. By melting a portion of such an ingot and slowly refreezing it, solutes in the molten region become distributed to form the desired n-p and p-n junctions.
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This is well known in reverse osmosis where solutes from the feedwater diffuse to the product water, however in the case of forward osmosis the situation can be far more complicated. In FO processes we may have solute diffusion in both directions depending on the composition of the draw solution and the feed water. This does two things; the draw solution solutes may diffuse to the feed solution and the feed solution solutes may diffuse to the draw solution. Clearly these phenomena have consequences in terms of the selection of the draw solution for any particular FO process.
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Solvophobic theory attempts to explain interactions between polar solvents and non-polar solutes. In the pure solvent, there are relatively strong cohesive forces between the solvent molecules due to hydrogen bonding or other polar interactions. Hence, non-polar solutes tend not to be soluble in polar solvents because these solvent-solvent binding interactions must be overcome first. When applied to liquid chromatography (LC), solvophobic theory attributes the retention of solutes on the stationary phase partly to the rejection of solute molecules by the solvent, and partly to the attraction of the solute molecules by the stationary phase.
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As in dialysis, in hemofiltration one achieves movement of solutes across a semi-permeable membrane. However, solute movement with hemofiltration is governed by convection rather than by diffusion. With hemofiltration, dialysate is not used. Instead, a positive hydrostatic pressure drives water and solutes across the filter membrane from the blood compartment to the filtrate compartment, from which it is drained.
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Diffusion is controlled by other factors such as pore size and soil skeleton, tortuosity of flow path, and distribution of the solvent (water) and solutes.
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Research has found that PMA may plausibly decrease the absorbency of guard cell membranes to solutes, thereby retarding all stomatal movements that are osmotically prompted.
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By the use of active transport, the tuna could move solutes out of their cells and use the kidneys as a means to preserve fluidity.
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Since laboratories measure serum solutes in terms of freezing point depression, the reported units are properly units of osmolality. When a measure of serum solutes is calculated, it is often done in units of osmolarity. While it is possible to convert between osmolality and osmolarity,Converting between osmolality and osmolarity. thereby deriving a more mathematically correct osmol gap calculation, in actual clinical practice this is not done.
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The adsorption of gases and solutes is usually described through isotherms, that is, the amount of adsorbate on the adsorbent as a function of its pressure (if gas) or concentration (for liquid phase solutes) at constant temperature. The quantity adsorbed is nearly always normalized by the mass of the adsorbent to allow comparison of different materials. To date, 15 different isotherm models have been developed.
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A red blood cell in a hypotonic solution, causing water to move into the cell. A hypotonic solution has a lower concentration of solutes than another solution. In biology, a solution outside of a cell is called hypotonic if it has a lower concentration of solutes relative to the cytosol. Due to osmotic pressure, water diffuses into the cell, and the cell often appears turgid, or bloated.
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Osmotic nephrosis refers to structural changes that occur at the cellular level in the human kidney. Cells, primarily of the straight proximal tubule, swell due to the formation of large vacuoles in the cytoplasm. These vacuoles occur in the presence of large amounts of certain solutes circulating in the tubules. However, despite the condition's name, the solutes do not cause change through osmotic forces but through pinocytosis.
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Larger plants direct solutes into the xylem via ray cells, or in tracheids, via osmosis through bordered pits. Solutes attract water, the pressure rises and vapor can redissolve. In some trees, the sound of the cavitation is audible, particularly in summer, when the rate of evapotranspiration is highest. Some deciduous trees have to shed leaves in the autumn partly because cavitation increases as temperatures decrease.
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NKCC proteins are membrane transport proteins that transport sodium (Na), potassium (K), and chloride (Cl) ions across the cell membrane. Because they move each solute in the same direction, NKCC proteins are considered symporters. They maintain electroneutrality by moving two positively charged solutes (sodium and potassium) alongside two parts of a negatively charged solute (chloride). Thus the stoichiometry of the transported solutes is 1Na:1K:2Cl.
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Depending on the concentration of solutes in the feed (which dictates the necessary concentration of solutes in the draw) and the intended use of the product of the FO process, this step may be all that is required. The forward osmosis process is also known as osmosis or in the case of a number of companies who have coined their own terminology 'engineered osmosis' and 'manipulated osmosis'.
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The major facilitator superfamily (MFS) is a superfamily of membrane transport proteins that facilitate movement of small solutes across cell membranes in response to chemiosmotic gradients.
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That is, as solutes are off- loaded into sink cells (by active or passive transport), the density of the phloem liquid decreases locally, creating a pressure gradient.
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This allows direct cytoplasm-to-cytoplasm flow of water and other nutrients along concentration gradients. In particular, symplastic flow is used in the root systems to bring in nutrients from soil. It moves these solutes from epidermis cells through the cortex into the endodermis. Once solutes reach the endodermal cells through apoplastic flow, they are forced into the symplastic pathway due to the presence of the Casparian strip.
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The slime mold Labyrinthula zosterae can cause the wasting disease of Zostera, with Z. marina being particularly susceptible, causing a decrease in the populations of the fauna that depend on Zostera. Zostera is able to maintain its turgor at a constant pressure in response to fluctuations in environmental osmolarity. It achieves this by losing solutes as the tide goes out and gaining solutes as the tide comes in.
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Water- bears (Tardigrada), microscopic multicellular organisms, can survive freezing by replacing most of their internal water with the sugar trehalose, preventing it from crystallization that otherwise damages cell membranes. Mixtures of solutes can achieve similar effects. Some solutes, including salts, have the disadvantage that they may be toxic at intense concentrations. In addition to the water-bear, wood frogs can tolerate the freezing of their blood and other tissues.
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A red blood cell in a hypertonic solution, causing water to move out of the cell. A hypertonic solution has a greater concentration of solutes than another solution. In biology, the tonicity of a solution usually refers to its solute concentration relative to that of another solution on the opposite side of a cell membrane; a solution outside of a cell is called hypertonic if it has a greater concentration of solutes than the cytosol inside the cell. When a cell is immersed in a hypertonic solution, osmotic pressure tends to force water to flow out of the cell in order to balance the concentrations of the solutes on either side of the cell membrane.
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In a typical scenario, an industrial process will use an extraction step in which solutes are transferred from the aqueous phase to the organic phase; this is often followed by a scrubbing stage in which unwanted solutes are removed from the organic phase, then a stripping stage in which the wanted solutes are removed from the organic phase. The organic phase may then be treated to make it ready for use again. After use, the organic phase may be subjected to a cleaning step to remove any degradation products; for instance, in PUREX plants, the used organic phase is washed with sodium carbonate solution to remove any dibutyl hydrogen phosphate or butyl dihydrogen phosphate that might be present.
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However, since the patient is unable to concentrate urine to excrete the excess solutes, the resulting urine fails to decrease serum osmolarity and the cycle repeats itself, hence polyuria.
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ProP is a bacterial membrane protein that is a member of the major facilitator superfamily. It functions as an osmosensory and osmoregulatory transporter, responding to changes in osmotic pressure by importing compatible solutes such as proline or glycine betaine; most substrates for ProP are zwitterions. The activity of ProP increases with osmotic pressure in cells and proteoliposomes. ProP is a symporter of hydrogen ions and compatible solutes, and is responsive to potassium concentrations.
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The solutes appear at the bottom of the column as a series of contiguous zones, each consisting of one purified component, with the concentration within each individual zone effectively uniform.
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The eluate is the analyte material that emerges from the chromatograph. It specifically includes both the analytes and solutes passing through the column, while the eluent is only the carrier.
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If there are N solutes or solvents, this procedure requires at least N measured wavelengths to create a solvable system of simultaneous equations, although using more wavelengths gives more reliable data.
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The concept of dialysis was introduced in 1861 by a British chemist, Thomas Graham. He used this technique to separate sucrose (small molecule) and gum Arabic solutes (large molecule) in aqueous solution. He called the diffusible solutes crystalloids and those that would not pass the membrane colloids. From this concept dialysis can be defined as a spontaneous separation process of suspended colloidal particles from dissolved ions or molecules of small dimensions through a semi permeable membrane.
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The mechanical properties of titanium foams are sensitive to the presence of interstitial solutes, which present limitations to processing routes and utilization. Titanium has a high affinity for atmospheric gases. In foams, this is evidenced by the metal's tendency to trap oxides within cell edges. Micro- hardness of cell walls, elastic modulus, and yield strength increase as a result of interstitial solutes; ductility, which is a function of the quantity of interstitial impurities, is consequently reduced.
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Though crystallized urinary solutes, such as oxalates, urates, or sulfonamides, may become enmeshed within a ketanaline cast during its formation, the clinical significance of this occurrence is not felt to be great.
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The osmotic potential is made possible due to the presence of both inorganic and organic solutes in the soil solution. As water molecules increasingly clump around solute ions or molecules, the freedom of movement, and thus the potential energy, of the water is lowered. As the concentration of solutes is increased, the osmotic potential of the soil solution is reduced. Since water has a tendency to move toward lower energy levels, water will want to travel toward the zone of higher solute concentrations.
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Ultrafiltration (UF) is a variety of membrane filtration in which forces like pressure or concentration gradients lead to a separation through a semipermeable membrane. Suspended solids and solutes of high molecular weight are retained in the so-called retentate, while water and low molecular weight solutes pass through the membrane in the permeate (filtrate). This separation process is used in industry and research for purifying and concentrating macromolecular (103 \- 106 Da) solutions, especially protein solutions. Ultrafiltration is not fundamentally different from microfiltration.
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The first strategy is employed by the majority of halophilic bacteria, some archaea, yeasts, algae, and fungi; the organism accumulates organic compounds in the cytoplasm—osmoprotectants which are known as compatible solutes. These can be either synthesised or accumulated from the environment. The most common compatible solutes are neutral or zwitterionic, and include amino acids, sugars, polyols, betaines, and ectoines, as well as derivatives of some of these compounds. The second, more radical adaptation involves selectively absorbing potassium (K+) ions into the cytoplasm.
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Once the solutes are passively filtered, they eventually reach the pericycle, where it can be moved into the xylem for long distance transport. It is contrasted with the apoplastic flow, which uses cell wall transport.
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Singly substituted isotopologues may be used for nuclear magnetic resonance experiments, where deuterated solvents such as deuterated chloroform (CDCl3) do not interfere with the solutes' 1H signals, and in investigations of the kinetic isotope effect.
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Depiction of a red blood cell in an isotonic solution. A solution is isotonic when its effective osmole concentration is the same as that of another solution. In biology, the solutions on either side of a cell membrane are isotonic if the concentration of solutes outside the cell is equal to the concentration of solutes inside the cell. In this case the cell neither swells nor shrinks because there is no concentration gradient to induce the diffusion of large amounts of water across the cell membrane.
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This results in favorable solute-solvent interactions and is also entropically favorable as the mixture is more disordered than when the solute and solvent are not mixed. Dissolution often occurs when the solute-solvent interactions are similar to the solvent-solvent interactions, signified by the term like dissolves like. Hence, polar solutes dissolve in polar solvents, whereas nonpolar solutes dissolve in nonpolar solvents. There is no one measure of solvent polarity and so classification of solvents based on polarity can be carried out using different scales.
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In 1889 Hamburger used hemolysis of erythrocytes to determine the permeability of various solutes. By measuring the time required for the cells to swell past their elastic limit, the rate at which solutes entered the cells could be estimated by the accompanying change in cell volume. He also found that there was an apparent nonsolvent volume of about 50% in red blood cells and later showed that this includes water of hydration in addition to the protein and other nonsolvent components of the cells.
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The "elution time" of a solute is the time between the start of the separation (the time at which the solute enters the column) and the time at which the solute elutes. In the same way, the elution volume is the volume of eluent required to cause elution. Under standard conditions for a known mix of solutes in a certain technique, the elution volume may be enough information to identify solutes. For instance, a mixture of amino acids may be separated by ion-exchange chromatography.
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The phospholipid bilayer is most permeable to small, uncharged solutes. Protein channels float through the phospholipids, and, collectively, this model is known as the fluid mosaic model. Aquaporins are protein channel pores permeable to H2O water.
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Empirical parameters are used to quantify the behaviour of solutions of ionic and non-ionic solutes which are not ideal solutions in the thermodynamic sense. The Pfeffer cell was developed for the measurement of osmotic pressure.
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A urinometer is a medical hydrometer designed for urinalysis. As urine's specific gravity is dictated by its ratio of solutes (wastes) to water, a urinometer makes it possible to quickly assess a patient's overall level of hydration.
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It is vital for organisms to be able to maintain their fluid levels in very narrow ranges. The goal is to keep the interstitial fluid, the fluid outside the cell, at the same concentration as the intracellular fluid, fluid inside the cell. This condition is called isotonic and occurs when the same level of solutes are present on either side of the cell membrane so that the net water movement is zero. If the interstitial fluid has a higher concentration of solutes than the intracellular fluid it will pull water out of the cell.
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The separatory funnel relies on the concept of "like dissolves like", which describes the ability of polar solvents to dissolve polar solutes and non-polar solvents to dissolve non-polar solutes. When the separatory funnel is agitated, each solute migrates to the solvent (also referred to as "phase") in which it is more soluble. The solvents normally do not form a unified solution together because they are immiscible. When the funnel is kept stationary after agitation, the liquids form distinct physical layers - lower density liquids will stay above higher density liquids.
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The use of micelles in high performance liquid chromatography was first introduced by Armstrong and Henry in 1980.D.W. Armstrong, Sep. Purif. Methods 14 (1985) 213 The technique is used mainly to enhance retention and selectivity of various solutes that would otherwise be inseparable or poorly resolved. Micellar liquid chromatography (MLC) has been used in a variety of applications including separation of mixtures of charged and neutral solutes, direct injection of serum and other physiological fluids, analysis of pharmaceutical compounds, separation of enantiomers, analysis of inorganic organometallics, and a host of others.
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Semipermeable membrane The principle of hemodialysis is the same as other methods of dialysis; it involves diffusion of solutes across a semipermeable membrane. Hemodialysis utilizes counter current flow, where the dialysate is flowing in the opposite direction to blood flow in the extracorporeal circuit. Counter-current flow maintains the concentration gradient across the membrane at a maximum and increases the efficiency of the dialysis. Fluid removal (ultrafiltration) is achieved by altering the hydrostatic pressure of the dialysate compartment, causing free water and some dissolved solutes to move across the membrane along a created pressure gradient.
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The end result is that solutes from the blood, particularly chloride, are secreted into the lumen of these exocrine glands, increasing the luminal concentration of solutes and causing water to be secreted by osmosis. In addition to exocrine glands, NKCC1 is necessary for establishing the potassium-rich endolymph that bathes part of the cochlea, an organ necessary for hearing. Inhibition of NKCC1, as with furosemide or other loop diuretics, can result in deafness. NKCC1 is also expressed in many regions of the brain during early development, but not in adulthood.
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Also included is a small catalog of unsaturated soil hydraulic properties, as well as pedotransfer functions based on neural networks. Both HYDRUS models also consider various provisions for simulating non-equilibrium flow and transport. The flow equation for the latter purpose can consider dual-porosity-type flow with a fraction of the water content being mobile, and a fraction immobile. The transport equations additionally were modified to allow consideration of kinetic attachment/detachment processes of solutes to the solid phase, and hence of solutes having a finite size.
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A chaotropic agent is a substance which disrupts the structure of, and denatures, macromolecules such as proteins and nucleic acids (e.g. DNA and RNA). Chaotropic solutes increase the entropy of the system by interfering with intermolecular interactions mediated by non-covalent forces such as hydrogen bonds, van der Waals forces, and hydrophobic effects. Macromolecular structure and function is dependent on the net effect of these forces (see protein folding), therefore it follows that an increase in chaotropic solutes in a biological system will denature macromolecules, reduce enzymatic activity and induce stress on a cell (i.e.
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Haloarchaea can grow at an aw close to 0.75, yet a water activity (aw) lower than 0.90 is inhibitory to most microbes. The number of solutes causes osmotic stress on microbes, which can cause cell lysis, unfolding of proteins and inactivation of enzymes when there is a large enough imbalance. Haloarchaea combat this by retaining compatible solutes such as potassium chloride (KCl) in their intracellular space to allow them to balance osmotic pressure. Retaining these salts is referred to as the “salt-in” method where the cell accumulates a high internal concentration of potassium.
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Typically, the draw solutes are sugars such as glucose or fructose, which provide the additional benefit of nutrition to the user of the FO device. A point of additional interest with such bags is that they may be readily used to recycle urine, greatly extending the ability of a backpacker or soldier to survive in arid environments. This process may also, in principle, be employed with highly concentrated saline feedwater sources such as seawater, as one of the first intended uses of FO with ingestible solutes was for survival in life rafts at sea.
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This fungus is xerotolerant as it can thrive in environments with low water activity caused by high salinity (halotolerant) or other dissolved solutes. This fungus has been observed to grow in as low as 0.815 aw in vitro.
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Solute flow is driven by a difference in hydraulic pressure created from the unloading of solutes in the sink tissues.Lambers, Hans (2008). Plant Physiological Ecology. 233 Spring Street, New York, NY: Springer Science+Business Media, LLC. p. 153. .
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The same phenomenon was noted for some halotolerant fungi. But, the concentration of MAAs within cyanobacteria living in hyper-saline environments is far from the amount required to balance the salinity. Therefore, additional osmotic solutes must be present as well.
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Tight junction strands serve as a physical barrier to prevent solutes and water from passing freely through the paracellular space between epithelial or endothelial cell sheets. Two alternatively spliced transcript variants that encode different isoforms have been identified for this gene.
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The symbiosome membrane is separated from the endosymbiont membrane by a space known as the symbiosome space, which allows for the exchange of solutes between the symbionts. In the plant root nodule the symbiosome membrane is also called the peribacteroid membrane.
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Solvents with a dielectric constant (more accurately, relative static permittivity) greater than 15 (i.e. polar or polarizable) can be further divided into protic and aprotic. Protic solvents solvate anions (negatively charged solutes) strongly via hydrogen bonding. Water is a protic solvent.
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Hemofiltration is sometimes used in combination with hemodialysis, when it is termed hemodiafiltration. Blood is pumped through the blood compartment of a high flux dialyzer, and a high rate of ultrafiltration is used, so there is a high rate of movement of water and solutes from blood to dialysate that must be replaced by substitution fluid that is infused directly into the blood line. However, dialysis solution is also run through the dialysate compartment of the dialyzer. The combination is theoretically useful because it results in good removal of both large and small molecular weight solutes.
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Effect of different solutions on red blood cells Micrographs of osmotic pressure on red blood cells Tonicity is a measure of the effective osmotic pressure gradient; the water potential of two solutions separated by a semipermeable cell membrane. In other words, tonicity is the relative concentration of solutes dissolved in solution which determine the direction and extent of diffusion. It is commonly used when describing the response of cells immersed in an external solution. Unlike osmotic pressure, tonicity is influenced only by solutes that cannot cross the membrane, as only these exert an effective osmotic pressure.
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A mixture of solutes is thus separated into two physically separate solutions, each enriched in different solutes. The valve may be opened after the two phases separate to allow the bottom layer to escape the separator funnel. The top layer may be retained in the separatory funnel for further extractions with additional batches of solvent or drained out into a separate vessel for other uses. If it is desired to retain the bottom layer in the separatory funnel for further extractions, both layers are taken out separately, and then the former bottom layer is returned to the separatory funnel.
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After a taxonomic revision in 2005 two other species were recognised in the genus, W. muriae (another xerophilic species) and the halophilic W. ichthyophaga. Wallemia sebi was distinguished from the other two in that it showed growth also on media without additional solutes, while W. ichthyophaga and W. muriae grow only in the present of additional solutes. In 2015 W. sebi was further split into W. sebi sensu stricto and three new species described as W. mellicola, W. canadensis, and W. tropicalis. The species differ in their conidial size, xerotolerance, halotolerance, chaotolerance, growth temperature regimes, extracellular enzyme activity profiles, and secondary metabolite patterns.
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After the entire sample is loaded, the feed is switched to the displacer, chosen to have higher affinity than any sample component. The displacer forms a sharp-edged zone at the head of the column, pushing the other components downstream. Each sample component now acts as a displacer for the lower-affinity solutes, and the solutes sort themselves out into a series of contiguous bands (a "displacement train"), all moving downstream at the rate set by the displacer. The size and loading of the column are chosen to let this sorting process reach completion before the components reach the bottom of the column.
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Methods for identifying baseflow sources and residence/transit time include using solutes and tracers. Solutes that originate in distinct areas of the watershed can be used to source baseflow-geochemical signatures. Tracers may be inserted into different parts of the watershed to identify flow paths and transit times. Methods for summarizing baseflow from an existing streamflow record include event based low flow statistics, flow duration curve, metrics that explain proportioning of baseflow to total flow, and the baseflow recession curve which can be used on ungauged streams based on empirical relationship between watershed characteristics and baseflow at gauged sites.
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Filtration. Filtration is movement of water and solute molecules across the cell membrane due to hydrostatic pressure generated by the cardiovascular system. Depending on the size of the membrane pores, only solutes of a certain size may pass through it. For example, the membrane pores of the Bowman's capsule in the kidneys are very small, and only albumins, the smallest of the proteins, have any chance of being filtered through. On the other hand, the membrane pores of liver cells are extremely large, but not forgetting cells are extremely small to allow a variety of solutes to pass through and be metabolized.
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Because of this, pressurization drives waste fluids from the inside of the animal, and they are pulled through small perforations in the terminal cells and into the protonephridium. The perforations in the terminal cell are large enough for small molecules to pass, but larger proteins are retained within the animal. From the bottom of the protonephridium the solutes are led through the tube, formed by the canal cells, and exits the animal from a small opening formed by the nephridiopore. Selective reabsorption of useful molecules by the canal cells occurs as the solutes pass down the tubule.
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In the preceding section, boiling points of pure compounds were covered. Vapor pressures and boiling points of substances can be affected by the presence of dissolved impurities (solutes) or other miscible compounds, the degree of effect depending on the concentration of the impurities or other compounds. The presence of non- volatile impurities such as salts or compounds of a volatility far lower than the main component compound decreases its mole fraction and the solution's volatility, and thus raises the normal boiling point in proportion to the concentration of the solutes. This effect is called boiling point elevation.
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As the polarity of the components decreases, the time spent in the column increases. Thus, a separation of components is achieved based on polarity. The addition of micelles to the mobile phase introduces a third phase into which the solutes may partition.
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In general, bulk flow in plant biology typically refers to the movement of water from the soil up through the plant to the leaf tissue through xylem, but can also be applied to the transport of larger solutes (e.g. sucrose) through the phloem.
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They hypothesized that this was due to a semipermeable membrane that protected the central nervous system from the passive diffusion of solutes in the bloodstream.Biedl, A; Kraus, R (1898). "Über eine bisher unbekannte toxische Wirkung der Gallensäure auf das Zentralnervensystem". Zentralbl. Inn.
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Insects may have one to hundreds of Malpighian tubules (element 20). These tubules remove nitrogenous wastes from the hemolymph of the insect and regulate osmotic balance. Wastes and solutes are emptied directly into the alimentary canal, at the junction between the midgut and hindgut.
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Members of the Solute:Sodium Symporter (SSS) Family (TC# 2.A.21) catalyze solute:Na+ symport. The SSS family is within the APC Superfamily. The solutes transported may be sugars, amino acids, organo cations such as choline, nucleosides, inositols, vitamins, urea or anions, depending on the system.
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The interactions between the analytes and the stationary phase and mobile phase lead to the separation of the analytes. In capillary electrochromatography capillaries, packed with HPLC stationary phase, are subjected to a high voltage. Separation is achieved by electrophoretic migration of solutes and differential partitioning.
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Fig. 1 A binary phase diagram displaying solid solutions over the full range of relative concentrations. A solid solution is a solid-state solution of one or more solutes in a solvent. Such a multi-component system is considered a solution rather than a compound when the crystal structure of the solvent remains unchanged by addition of the solutes, and when the chemical components remain in a single homogeneous phase. This often happens when the two elements (generally metals) involved are close together on the periodic table; conversely, a chemical compound generally results when two metals involved are not near each other on the periodic table.
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Scientific studies documenting the widespread alteration of sediment dynamics (i.e. sediment supply, sediment entrainment, transport, erosion, deposition and storage) by humans lead to the evidence that human activities have come to dominate erosional, depositional and geochemical processes in ecosystems. This is especially pronounced in river systems, given that rivers are the lowest topographic points of any landscape and consequently collect water, solutes, mineral sediment and particular organic matter from the landscape, but also precipitation, solutes and particulates from the atmosphere. Furthermore, increased sediment supply to rivers but reduced sediment transport within a fluvial network resulted in the creation of legacy effects along almost all rivers across the world.
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Water removal is based on the natural and non-destructive phenomenon of osmosis across cell membranes. The driving force for the diffusion of water from the tissue into the solution is provided by the higher osmotic pressure of the hyper-tonic solution. The diffusion of water is accompanied by the simultaneous counter diffusion of solutes from the osmotic solution into the tissue. Since the cell membrane responsible for osmotic transport is not perfectly selective, solutes present in the cells (organic acids, reducing sugars, minerals, flavors and pigment compounds) can also be leaked into the osmotic solution, which affects the organoleptic and nutritional characteristics of the product.
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The evaluation of the ecological role of bioturbators has largely been species-specific. However, their ability to transport solutes, such as dissolved oxygen, enhance organic matter decomposition and diagenesis, and alter sediment structure has made them important for the survival and colonization by other macrofaunal and microbial communities. Microbial communities are greatly influenced by bioturbator activities, as increased transport of more energetically favorable oxidants, such as oxygen, to typically highly reduced sediments at depth alters the microbial metabolic processes occurring around burrows. As bioturbators burrow, they also increase the surface area of sediments across which oxidized and reduced solutes can be exchanged, thereby increasing the overall sediment metabolism.
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The coefficient lies always in range <0,1> and 0 indicates worst case of separation (all Rf values equal to 0 or 1), value 1 indicates ideal equal-spreading of the spots, for example (0.25,0.5,0.75) for three solutes, or (0.2,0.4,0.6,0.8) for four solutes. This coefficient was proposed as an alternative to earlier approaches, such as D (separation response), Ip (performance index) or Sm (informational entropy). Besides its stable range, the advantage is a stable distribution as a random variable, regardless of compounds investigated. In contrast to the similar concept called Retention distance, Ru is insensitive to Rf values close to 0 or 1, or close to themselves.
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The coefficient lies always in range <0,1> and 0 indicates worst case of separation (all Rf values equal to 0 or 1), value 1 indicates ideal equal-spreading of the spots, for example (0.25,0.5,0.75) for three solutes, or (0.2,0.4,0.6,0.8) for four solutes. This coefficient was proposed as an alternative to earlier approaches, such as delta-Rf, delta-Rf product or MRF (Multispot Response Function). Besides its stable range, the advantage is a stable distribution as a random variable, regardless of compounds investigated. In contrast to the similar concept called Retention uniformity, Rd is sensitive to Rf values close to 0 or 1, or close to themselves.
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In cellular biology, membrane transport refers to the collection of mechanisms that regulate the passage of solutes such as ions and small molecules through biological membranes, which are lipid bilayers that contain proteins embedded in them. The regulation of passage through the membrane is due to selective membrane permeability - a characteristic of biological membranes which allows them to separate substances of distinct chemical nature. In other words, they can be permeable to certain substances but not to others. The movements of most solutes through the membrane are mediated by membrane transport proteins which are specialized to varying degrees in the transport of specific molecules.
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The energy required to move solutes across the cell membrane is provided by the electrochemical gradient of sodium. Sodium's electrochemical gradient is established by the Na-K ATPase, which is an ATP-dependent enzyme. Since NKCC proteins use sodium's gradient, their activity is indirectly dependent on ATP; for this reason, NKCC proteins are said to move solutes by way of secondary active transport. There are three isoforms of NKCC2 created by alternative splicing (NKCC2A, B and F). Each one of these isoforms is expressed at different portions of the thick ascending limb and they have different affinity for sodium that correlates with its localization.
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The idea of a semipermeable membrane, a barrier that is permeable to solvent but impermeable to solute molecules was developed at about the same time. The term osmosis originated in 1827 and its importance to physiological phenomena realized, but it was not until 1877 when the botanist Wilhelm Pfeffer proposed the membrane theory of cell physiology. In this view, the cell was seen to be enclosed by a thin surface, the plasma membrane, and cell water and solutes such as a potassium ion existed in a physical state like that of a dilute solution. In 1889, Hamburger used hemolysis of erythrocytes to determine the permeability of various solutes.
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At this time, the tight junctions are quite 'leaky' allowing movement of fluid and solutes between the epithelial cells.Lindsay, L. A., & Murphy, C. R. (2004). Redistribution of aquaporins in uterine epithelial cells at the time of implantation in the rat. Acta histochemica, 106(4), 299-307.
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They function as a selective and semipermeable paracellular barrier between apical and basolateral compartments of the epithelial layer. They function to facilitate the passage of small ions and water-soluble solutes through the paracellular space while preventing the passage of luminal antigens, microorganisms and their toxins.
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When abscisic acid signals the guard cells, free Ca2+ ions enter the cytosol from both outside the cell and internal stores, reversing the concentration gradient so the K+ ions begin exiting the cell. The loss of solutes makes the cell flaccid and closes the stomatal pores.
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At Bonn, where he had studied as an undergraduate, he occupied Kekulé's chair. Pfeiffer's work spanned many themes. The Pfeiffer effect, which involves interactions between chiral solutes, is named after his discoveries. His group first made the salen ligands, which gave the first artificial oxygen carriers.
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In neonates, normal urine specific gravity is 1.003. Hypovolemic patients usually have a specific gravity >1.015. Decreased specific gravity (hyposthenuria, i.e. decreased concentration of solutes in urine) may be associated with renal failure, pyelonephritis, diabetes insipidus, acute tubular necrosis, interstitial nephritis, and excessive fluid intake (e.g.
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The volume of the fluid is reduced by allowing permeate flow to occur. Solvent, solutes, and particles smaller than the membrane pore size pass through the membrane, while particles larger than the pore size are retained, and thereby concentrated. In bioprocessing applications, concentration may be followed by diafiltration.
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For some examples of this effect, see liquid-liquid extraction. It is possible to extract a solute from one liquid phase to another without a chemical reaction. Examples of such solutes are noble gases and osmium tetroxide. The process of absorption means that a substance captures and transforms energy.
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MFSD8 is a ubiquitous integral membrane protein which contains a transporter domain and a major facilitator superfamily (MFS) domain. Other members of the major facilitator superfamily transport small solutes through chemiosmotic ion gradients. The substrate transported by this protein is unknown. The protein, likely localizes to lysosomal membranes.
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Macropinosomes serve primarily in the uptake of solutes from the extracellular fluid. Once inside the cell, macropinosomes undergo a process of maturation characterized by increasing expression of Rab7 as they progress through the endocytic pathway, until they fuse with lysosomes where the contents of the macropinosome are degraded.
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All the metabolic wastes are excreted in a form of water solutes through the excretory organs (nephridia, Malpighian tubules, kidneys), with the exception of CO2, which is excreted together with the water vapor throughout the lungs. The elimination of these compounds enables the chemical homeostasis of the organism.
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In contrast to elution chromatography, solutes separated in displacement mode form sharp-edged zones rather than spreading peaks. Zone boundaries in displacement chromatography are self-sharpening: if a molecule for some reason gets ahead of its band, it enters a zone in which it is more strongly retained, and will then run more slowly until its zone catches up. Furthermore, because displacement chromatography takes advantage of the non-linearity of the isotherms, loadings are deliberately high; more material can be separated on a given column, in a given time, with the purified components recovered at significantly higher concentrations. Retention conditions can still be adjusted, but the displacer controls the migration rate of the solutes.
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The glymphatic system (or glymphatic clearance pathway, or paravascular system) is a functional waste clearance pathway for the vertebrate central nervous system (CNS). The pathway consists of a para-arterial influx route for cerebrospinal fluid (CSF) to enter the brain parenchyma, coupled to a clearance mechanism for the removal of interstitial fluid (ISF) and extracellular solutes from the interstitial compartments of the brain and spinal cord. Exchange of solutes between CSF and ISF is driven primarily by arterial pulsation and regulated during sleep by the expansion and contraction of brain extracellular space. Clearance of soluble proteins, waste products, and excess extracellular fluid is accomplished through convective bulk flow of ISF, facilitated by astrocytic aquaporin 4 (AQP4) water channels.
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Insensible perspiration is the loss of water through the skin which does not occur as perceivable sweat. Insensible perspiration takes place at an almost constant rate and reflects evaporative loss from the epithelial cells of the skin. Unlike in sweating, the fluid lost is pure water, i.e. no solutes are lost.
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Glycerol facilitators function as solute nonspecific channels, and may transport glycerol, dihydroxyacetone, propanediol, urea and other small neutral molecules in physiologically important processes. Some members of the family, including the yeast Fps1 protein (TC# 1.A.8.5.1) and tobacco NtTIPa (TC# 1.A.8.10.2) may transport both water and small solutes.
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Thermal (heat) stress is defined as temperatures lethal or inhibitory towards growth. MAA concentrations have been shown to be up- regulated when an organism is under thermal stress. Multipurpose MAAs could also be compatible solutes under freezing conditions, because a high incidence of MAA producing organisms have been reported in cold aquatic environments.
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The blood-brain barrier appears to be functional by the time of birth. P-glycoprotein, a transporter, exists already in the embryonal endothelium. Measurement of brain uptake of various blood-borne solutes showed that newborn endothelial cells were functionally similar to those in adults, indicating that a selective BBB is operative at birth.
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Solid countermeasures to radiation damage consist of three approaches. Firstly, saturating the matrix with oversized solutes. This acts to trap the swelling that occurs as a result of the creep and dislocation motion. They also act to help prevent diffusion, which restricts the ability of the material to undergo radiation induced segregation.
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Dialysis works on the principles of the diffusion of solutes and ultrafiltration of fluid across a semi-permeable membrane. Diffusion is a property of substances in water; substances in water tend to move from an area of high concentration to an area of low concentration.Mosby’s Dictionary of Medicine, Nursing, & Health Professions. 7th ed.
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Retention in elution chromatography is usually controlled by adjusting the composition of the mobile phase (in terms of solvent composition, pH, ionic strength, and so forth) according to the type of stationary phase employed and the particular solutes to be separated. The mobile phase components generally have lower affinity for the stationary phase than do the solutes being separated, but are present at higher concentration and achieve their effects due to mass action. Resolution in elution chromatography is generally better when peaks are strongly retained, but conditions that give good resolution of early peaks lead to long run-times and excessive broadening of later peaks unless gradient elution is employed. Gradient equipment adds complexity and expense, particularly at large scale.
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The heat transport equation considers conduction as well as advection with flowing water. The solute transport equations assume advective-dispersive transport in the liquid phase, and diffusion in the gaseous phase. The transport equations further include provisions for nonlinear and/or non-equilibrium reactions between the solid and liquid phases, linear equilibrium reactions between the liquid and gaseous phases, zero-order production, and two first-order degradation reactions: one which is independent of other solutes, and one which provides the coupling between solutes involved in sequential first order decay reactions. In addition, physical non-equilibrium solute transport can be accounted for by assuming a two-region, dual-porosity type formulation which partitions the liquid phase into mobile and immobile regions.
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Stool osmotic gap is a measure of the concentration of those other compounds. Stool osmotic gap is calculated as 290 mOsm/kg − 2 × (stool Na + stool K). 290 mOsm/kg is the presumed stool osmolality, and the measured concentration of sodium and potassium cations is doubled to account for the corresponding anions which must be present. A normal gap is between 50 and 100 mOsm/kg, corresponding to the concentration of other solutes such as magnesium salts and sugars. A low stool osmotic gap suggests secretory diarrhea, wherein the digestive tract is hyperpermeable and losing electrolytes, while a high gap suggests osmotic diarrhea, wherein the digestive tract is unable to absorb solutes from the chyme, either because the digestive tract is hypopermeable (e.g.
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Osmotic Membrane Processes Forward osmosis (FO) is an osmotic process that, like reverse osmosis (RO), uses a semi-permeable membrane to effect separation of water from dissolved solutes. The driving force for this separation is an osmotic pressure gradient, such that a "draw" solution of high concentration (relative to that of the feed solution), is used to induce a net flow of water through the membrane into the draw solution, thus effectively separating the feed water from its solutes. In contrast, the reverse osmosis process uses hydraulic pressure as the driving force for separation, which serves to counteract the osmotic pressure gradient that would otherwise favor water flux from the permeate to the feed. Hence significantly more energy is required for reverse osmosis compared to forward osmosis.
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Aquaporin-9 is a protein that in humans is encoded by the AQP9 gene. The aquaporins/major intrinsic protein are a family of water-selective membrane channels. Aquaporin 9 has greater sequence similarity with AQP3 and AQP7 and they may be a subfamily. Aquaporin 9 allows passage of a wide variety of noncharged solutes.
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Pure lipid bilayers are generally permeable only to small, uncharged solutes. Hence, whether or not a molecule is ionized will affect its absorption, since ionic molecules are charged. Solubility favors charged species, and permeability favors neutral species. Some molecules have special exchange proteins and channels to facilitate movement from the lumen into the circulation.
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Solutes able to freely cross the membrane do not affect tonicity because they will always equilibrate with equal concentrations on both sides of the membrane without net solvent movement. It is also a factor affecting imbibition. There are three classifications of tonicity that one solution can have relative to another: hypertonic, hypotonic, and isotonic.
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For example, the intracellular fluid and extracellular can be hyperosmotic, but isotonic – if the total concentration of solutes in one compartment is different from that of the other, but one of the ions can cross the membrane (in other words, a penetrating solute), drawing water with it, thus causing no net change in solution volume.
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Inborn errors of renal tubular transport are metabolic disorders which lead to impairment in the ability of solutes, such as salts or amino acids, to be transported across the brush border of the renal tubule. This results in disruptions of renal reabsorption. Examples of these disorders include Iminoglycinuria, renal tubular acidosis and Gitelman syndrome.
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Many laboratories rely on only the color of the cerebrospinal fluid to determine the presence or absence of xanthochromia. However, recent guidelines suggest that spectrophotometry should be performed. Spectrophotometry relies on the different transmittance, or conversely, absorbance, of light by different substances or materials, including solutes. Bilirubin absorbs light at wavelengths between 450–460 nm.
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When one substance dissolves into another, a solution is formed. A solution is a homogeneous mixture consisting of a solute dissolved into a solvent. The solute is the substance that is being dissolved, while the solvent is the dissolving medium. Solutions can be formed with many different types and forms of solutes and solvents.
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Ogston AG, Phelps CF. The partition of solutes between buffer solutions and solutions containing hyaluronic acid. Biochem J 1960;78:827–833. HA is commonly injected intra-articular (IA) into diseased joints, but its exact mechanism of action is unknown. HA concentration and molecular weight are sometimes lower in diseased joints, but this is not always the case.
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A second vial is also sent to the laboratory. This vial is put in an instrument that measures the freezing point depression of all the solutes in the plasma. This measurement gives the true plasma osmolality. The calculated osmolality is then subtracted from the measured osmolality to provide the osmol gap, or the difference between these two values.
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Yuri Gamalei first described the different types of phloem-loading mechanisms in 1989, correlating loading strategy with the leaf's anatomy. He found that plasmodesmatal abundance in the minor veins of leaves was correlated with a plant's loading strategy. Plasmodesmata allow solutes to diffuse through the symplast. Thus, plants with a lot of plasmodesmata are generally passive loaders.
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Dongling Lake lies on the north edge of the Qarhan Playa at an elevation of above sea level. It has an area of . Its depth does not usually exceed . Dongling's position at the northern end of the playa means that its waters are far more influenced by the mineral springs and their high concentrations of solutes.
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It is when there is an elevated level of solutes within the soil that inhibit the growth and metabolic capabilities of crops. Salinity stress is a problem that affects A. desertorum in the more semiarid parts of North America.Golpalvar, A. R. (2011). Multivariate analysis of germination ability and tolerance to salinity in Agropyron desertorum genotypes in greenhouse condition.
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The structure of the tetracyclic ring of cholesterol contributes to the fluidity of the cell membrane, as the molecule is in a trans conformation making all but the side chain of cholesterol rigid and planar. In this structural role, cholesterol also reduces the permeability of the plasma membrane to neutral solutes, hydrogen ions, and sodium ions.
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His current research interest is in understanding the effects of solutes on mechanical properties of magnesium and its hot workability. A major recent research programme addressed basic issue of fracture toughness in single phase and dilute alloys. He has to his credit nearly 160 journal papers, 30 edited volumes and over 50 publications in conference proceedings.
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Kharakoz DP, Sarvazyan AP. Hydrational and intrinsic compressibilities of globular proteins. Biopolymers, 1993; 33: 11-26. He continued these studies on the hydration of biopolymers at the Laboratory of Biomolecular Acoustics, which he organized at Rutgers University, NJ, US in 1992.Chalikian TV, Sarvazyan AP, Breslauer KJ. Hydration and compressibility of biological solutes. Biophys. Chem. 1994; 51: 89-109.
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Whereas chaotropicity was first applied to studies of ions, it is equally applicable to alcohols, aromatics, ion mixtures and other solutes. Furthermore, hydrophobic substances known to stress cellular systems (including benzene and toluene) can chaotropically disorder macromolecules, and induce a chaotrope-stress response in microbial cells, even though they partition into the hydrophobic domains of macromolecular systems.
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The normal human kidney, through suppression of anti-diuretic hormone, is normally able to excrete vast amounts of dilute urine. Thus a normal adult can drink up to 20 liters per day of water without becoming hyponatremic. However, the intake of solutes is also necessary to excrete free water. Under normal circumstances, this is clinically irrelevant.
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This reduces the total amount of water leaving the blood. Another function of AVT is its ability to increase permeability of the collecting ducts by opening protein water channels. These channels, called aquaporins, allow more solutes to leave the collecting duct and water will follow through osmosis. These two functions of AVT allow birds to maintain a concentrated urine.
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These porous channels act like a sponge, and capillary action draws in liquids over time, along with any dissolved salts and other solutes. Very porous stone, such as sandstone absorb liquids relatively quickly, while denser igneous stones such as granite are significantly less porous; they absorb smaller volumes, and more slowly, especially when absorbing viscous liquids.
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Int J Syst Evol Microbiol 62: 1613–1618. This haloalkaliphilic bacterium synthesizes and intracellularly accumulates organic solutes such as ectoine that are of biotechnological interest.Shetty, S.A., Marathe, N.P., Munot, H., Antony, C.P., Dhotre, D.P., Murrell, J.C., and Shouche, Y.S., Draft genome sequence of Methylophaga lonarensis MPL, a haloalkaliphilic (non- methane-utilizing) methylotroph, Genome Announc., 2013, vol.
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The Malpighian tubules are significant for excretory features by throwing out excess and unnecessary solutes. Ileum, on the other hand, has the function of balancing the ion, water, organic compounds, and protein balance in the body. Together, the two organs work together to achieve homeostasis within the Bombus morios bodies despite the lack of rectal papillae.
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Superplasticizers are concrete admixtures designed to increase the concrete fluidity and workability of concrete or to decrease its water-to-cement (w/c) ratio. By reducing the water content in concrete, it decreases its porosity, improving so the mechanical properties (compressive and tensile strength) and the durability of concrete (lower water, gas and solutes transport properties).
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Many gels and colloids are thixotropic materials, exhibiting a stable form at rest but becoming fluid when agitated. Thixotropy arises because particles or structured solutes require time to organize. An overview of thixotropy has been provided by Mewis and Wagner. Some fluids are anti-thixotropic: constant shear stress for a time causes an increase in viscosity or even solidification.
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Many salts behave like barium nitrate and disodium hydrogen arsenate, and show a large increase in solubility with temperature (ΔG > 0). Some solutes (e.g. sodium chloride in water) exhibit solubility that is fairly independent of temperature (ΔG ≈ 0). A few, such as calcium sulfate (gypsum) and cerium(III) sulfate, become less soluble in water as temperature increases (ΔG < 0).
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Analysis of genetically modified mice that lacked the AQP4 gene revealed that the bulk flow-dependent clearance of interstitial solutes decreases by 70% in the absence of AQP4. Based upon this role of AQP4-dependent glial water transport in the process of paravascular interstitial solute clearance, Iliff and Nedergaard termed this brain-wide glio-vascular pathway the "glymphatic system".
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Discharge of untreated water from industrial uses is pollution. Pollution includes discharged solutes (chemical pollution) and increased water temperature (thermal pollution). Industry requires pure water for many applications and utilizes a variety of purification techniques both in water supply and discharge. Most of this pure water is generated on site, either from natural freshwater or from municipal grey water.
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The CRFs in thin layer chromatography characterize the equal-spreading of the spots. The ideal case, when the RF of the spots are uniformly distributed in <0,1> range (for example 0.25,0.5 and 0.75 for three solutes) should be characterized as the best situation possible. The simplest criteria are \Delta R_F and \Delta R_F product (Wang et al., 1996).
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Preparative- scale ion exchange column used for protein purification. Ion exchange chromatography can be used to separate proteins because they contain charged functional groups. The ions of interest (in this case charged proteins) are exchanged for another ions (usually H+) on a charged solid support. The solutes are most commonly in a liquid phase, which tends to be water.
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Destouni was a research fellow at the Swedish Natural Science Research Council from 1992 to 1998. Here she worked on hydrological transport models, and spent a year as a visiting scientist at the University of Florida. Her early research included the transport of solutes by groundwater in aquifers. In particular, she looked at hydrological transport in soil-groundwater systems.
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The vapour contacts a cool surface where it condenses as a liquid. Because the solutes are not normally vaporised, they remain in the boiling solution. Even distillation does not completely purify water, because of contaminants with similar boiling points and droplets of unvapourised liquid carried with the steam. However, 99.9% pure water can be obtained by distillation.
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Unlike the widely used automotive antifreeze, ethylene glycol, AFPs do not lower freezing point in proportion to concentration. Rather, they work in a noncolligative manner. This phenomenon allows them to act as an antifreeze at concentrations 1/300th to 1/500th of those of other dissolved solutes. Their low concentration minimizes their effect on osmotic pressure.
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The proximal tubule as a part of the nephron can be divided into an initial convoluted portion and a following straight (descending) portion. Fluid in the filtrate entering the proximal convoluted tubule is reabsorbed into the peritubular capillaries, including more than half of the filtered salt and water and all filtered organic solutes (primarily glucose and amino acids).
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Other potential traits that C. geophilum may employ for water stress tolerance include the production and accumulation of compatible osmolytes Jennings, D. H., & Burke, R. M. (1990). Compatible solutes–the mycological dimension and their role as physiological buffering agents. New Phytologist,116(2), 277-283.Bois, G., Bertrand, A., Piché, Y., Fung, M., & Khasa, D. P. (2006).
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This gene encodes a member of the claudin family. Claudins are integral membrane proteins and components of tight junction strands. Tight junction strands serve as a physical barrier to prevent solutes and water from passing freely through the paracellular space between epithelial or endothelial cell sheets. Mutations in this gene have been found in patients with velocardiofacial syndrome.
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High concentrations of some solutes can be very damaging. ; Extracellular ice formation: When tissues are cooled slowly, water migrates out of cells and ice forms in the extracellular space. Too much extracellular ice can cause mechanical damage to the cell membrane due to crushing. ; Dehydration: Migration of water, causing extracellular ice formation, can also cause cellular dehydration.
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This gene encodes a member of the claudin family. Claudins are integral membrane proteins and components of tight junction strands. Tight junction strands serve as a physical barrier to prevent solutes and water from passing freely through the paracellular space between epithelial or endothelial cell sheets, and also play critical roles in maintaining cell polarity and signal transductions. [provided by RefSeq, Jun 2010].
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In addition, the entropy change of solution is usually positive for most solid solutes like ionic compounds, which means that their solubility increases when the temperature increases. There are some unusual ionic compounds such as cerium(III) sulfate, where this entropy change is negative, due to extra order induced in the water upon solution, and the solubility decreases with temperature.
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A collecting column at the top collects the foam being produced. The foam is then collected and collapsed in another container. In the continuous foam separation process a continuous gas line is fed into the solution, therefore causing continuous foaming to occur. Continuous foam separation may not be as efficient in separating solutes as opposed to separating a fixed amount of solution.
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Mixed-mode chromatography (MMC), or multimodal chromatography, refers to chromatographic methods that utilize more than one form of interaction between the stationary phase and analytes in order to achieve their separation. What is distinct from conventional single-mode chromatography is that the secondary interactions in MMC cannot be too weak, and thus they also contribute to the retention of the solutes.
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Such a transformation is responsible for MscL's unitary conductance of 3nS and the channel's lack of selectivity, allowing any particles with a molecular weight smaller than ~1,000. This property of MscL fulfills its role as an emergency valve to release solutes under osmotic shock. Two models have been proposed in explaining the gating mechanism of MS channels: membrane-mediated mechanism and trapdoor mechanism.
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Thiazide diuretics are used in treatment because diabetes insipidus causes the excretion of more water than sodium (i.e., dilute urine). This condition results in a net concentrating effect on the serum (increasing its osmolarity). This high serum osmolarity stimulates polydipsia in an attempt to dilute the serum back to normal and provide free water for excreting the excess serum solutes.
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In contrast to phagocytosis, it generates very small amounts of ATP from the wastes of alternative substances such as lipids (fat). Unlike receptor-mediated endocytosis, pinocytosis is nonspecific in the substances that it transports. The cell takes in surrounding fluids, including all solutes present. Pinocytosis also works as phagocytosis; the only difference is that phagocytosis is specific in the substances it transports.
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CP affects almost all the available membrane separation processes. In RO, the solutes retained at the membrane layer results in higher osmotic pressure in comparison to the bulk stream concentration. So the higher pressures are required to overcome this osmotic pressure. Concentration polarisation plays a dominant role in ultrafiltration as compared to microfiltration because of the small pore size membrane.
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A proinflammatory cytokine affects functions of transporters and ion channels from the nephron. As a result, there is a change in the activity of the potassium ion (K+) channels that changes the transepithelial transport of solutes and water in the kidney. The kidney proximal tubule cells produce proinflammatory cytokines in response to lipopolysaccharide. Proinflammatory cytokines affect the renal K+ channels.
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A protein mutated in the rare human genetic disease, nephropathic intermediate cystinosis, also called cystinosin (TC# 2.A.43.1.1), is encoded by the CTNS gene. In cystinotic renal proximal tubules (RPTs), diminished cystinosin function appears to result in reduced reabsorption of solutes by other secondary transporters such as the Na+/Phosphate cotransporter, due to decreased expression of these other transport proteins.
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Paracellular permeability depends on transport through the spaces that exist between epithelial cells. It is regulated by cellular junctions that are localized in the laminal membranes of the cells. This is the main route of passive flow of water and solutes across the intestinal epithelium. Regulation depends on the intercellular tight junctions which have the most influence on paracellular transport.
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Aquaglyceroporins are recognized as a subset of the aquaporin family of proteins which conduct water, glycerol and other small, uncharged solutes. They are the only mammal proteins which are able to permeate glycerol through the plasma membrane. Aquaglyceroporins are found in many species including bacteria, plants and humans. Because of their ubiquitous nature they are important in agriculture as well as medicine.
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Dialyzers come in many different sizes. A larger dialyzer with a larger membrane area (A) will usually remove more solutes than a smaller dialyzer, especially at high blood flow rates. This also depends on the membrane permeability coefficient K0 for the solute in question. So dialyzer efficiency is usually expressed as the K0A – the product of permeability coefficient and area.
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The diffusion of water through a selectively permeable membrane is called osmosis. This allows only certain particles to go through including water and leaving behind the solutes including salt and other contaminants. In the process of reverse osmosis, thin film composite membranes (TFC or TFM) are used. These are semipermeable membranes manufactured principally for use in water purification or desalination systems.
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Membrane channels are a family of biological membrane proteins which allow the passive movement of ions (ion channels), water (aquaporins) or other solutes to passively pass through the membrane down their electrochemical gradient. They are studied using a range of channelomics experimental and mathematical techniques. Insights have suggested endocannabinoids (eCBs) as molecules that can regulate the opening of these channels during diverse conditions.
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The separation factor is one distribution ratio divided by another; it is a measure of the ability of the system to separate two solutes. For instance, if the distribution ratio for nickel (DNi) is 10 and the distribution ratio for silver (DAg) is 100, then the silver/nickel separation factor (SFAg/Ni) is equal to DAg/DNi = SFAg/Ni = 10.
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The blood–brain barrier (BBB) is a highly selective semipermeable border of endothelial cells that prevents solutes in the circulating blood from non- selectively crossing into the extracellular fluid of the central nervous system where neurons reside. The blood-brain barrier is formed by endothelial cells of the capillary wall, astrocyte end-feet ensheathing the capillary, and pericytes embedded in the capillary basement membrane. This system allows the passage of some molecules by passive diffusion, as well as the selective transport of various nutrients, ions, organic anions, and macromolecules such as glucose, water and amino acids that are crucial to neural function. The blood-brain barrier restricts the passage of pathogens, the diffusion of solutes in the blood, and large or hydrophilic molecules into the cerebrospinal fluid, while allowing the diffusion of hydrophobic molecules (O2, CO2, hormones) and small polar molecules.
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The concentrations of solutes normally found in the urine (for example potassium, phosphorus and urea) are undesirably high in the blood, but low or absent in the dialysis solution, and constant replacement of the dialysate ensures that the concentration of undesired solutes is kept low on this side of the membrane. The dialysis solution has levels of minerals like potassium and calcium that are similar to their natural concentration in healthy blood. For another solute, bicarbonate, dialysis solution level is set at a slightly higher level than in normal blood, to encourage diffusion of bicarbonate into the blood, to act as a pH buffer to neutralize the metabolic acidosis that is often present in these patients. The levels of the components of dialysate are typically prescribed by a nephrologist according to the needs of the individual patient.
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Examples of this include borax, calomel, milk of magnesia, muriatic acid, oil of vitriol, saltpeter, and slaked lime. Soluble ionic compounds like salt can easily be dissolved to provide electrolyte solutions. This is a simple way to control the concentration and ionic strength. The concentration of solutes affects many colligative properties, including increasing the osmotic pressure, and causing freezing-point depression and boiling-point elevation.
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Because the solutes are charged ions they also increase the electrical conductivity of the solution. The increased ionic strength reduces the thickness of the electrical double layer around colloidal particles, and therefore the stability of emulsions and suspensions. The chemical identity of the ions added is also important in many uses. For example, fluoride containing compounds are dissolved to supply fluoride ions for water fluoridation.
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There are two types of companion cells. #Ordinary companion cells, which have smooth walls and few or no plasmodesmatal connections to cells other than the sieve tube. #Transfer cells, which have much-folded walls that are adjacent to non- sieve cells, allowing for larger areas of transfer. They are specialized in scavenging solutes from those in the cell walls that are actively pumped requiring energy.
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Solubility of gases in liquids is influenced by the nature of the solvent liquid and the solute, the temperature, pressure, and the presence of other solutes in the solvent. Diffusion is faster in smaller, lighter molecules of which helium is the extreme example. Diffusivity of helium is 2.65 times faster than nitrogen. The concentration gradient, can be used as a model for the driving mechanism of diffusion.
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Halothiobacillus is a genus in the Gammaproteobacteria. Both species are obligate aerobic bacteria; they require oxygen to grow. They are also halotolerant; they live in environments with high concentrations of salt or other solutes, but don't require them in order to grow. The type species of this genus, Halothiobacillus neapolitanus used to be members of the genus Thiobacillus, before they were reclassified in 2000.
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The pia mater is a thin fibrous tissue that is permeable to water and small solutes. The pia mater allows blood vessels to pass through and nourish the brain. The perivascular space between blood vessels and pia mater is proposed to be part of a pseudolymphatic system for the brain (glymphatic system). When the pia mater becomes irritated and inflamed the result is meningitis.
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Monoliths exhibit no shear forces or eddying effects. High interconnectivity of the mesopores allows for multiple avenues of convective flow through the column. Mass transport of solutes through the column is relatively unaffected by flow rate. This is completely at odds to traditional particulate packings, whereby eddy effects and shear forces contribute greatly to the loss of resolution and capacity, as seen in the vanDeemter curve.
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Charles Clément Burlureaux was a French physician and psychiatrist. He also worked as an associate professor at Val de Grâce in Paris. Buruleaux was born in Dijon, France on July 24, 1851 and died on January 18, 1927. While at Val de Grâce, he designed an early perfusion apparatus to deliver solutes via perfusion and also studied using creosote oil injections as a treatment for tuberculosis.
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In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration. A concentration can be any kind of chemical mixture, but most frequently solutes and solvents in solutions. The molar (amount) concentration has variants such as normal concentration and osmotic concentration.
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The following types of liposomes are visible: small monolamellar vesicles, large monolamellar vesicles, multilamellar vesicles, oligolamellar vesicles. A liposome has an aqueous solution core surrounded by a hydrophobic membrane, in the form of a lipid bilayer; hydrophilic solutes dissolved in the core cannot readily pass through the bilayer. Hydrophobic chemicals associate with the bilayer. A liposome can be hence loaded with hydrophobic and/or hydrophilic molecules.
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Sediment cover slows the cooling and reduces the flow of water. There is little evidence of microbe activity in older (more than 10 million year old) crust. Near subduction zones, volcanoes can form in island arcs and back- arc regions. The subducting plate releases volatiles and solutes to these volcanoes, resulting in acidic fluids with higher concentrations of gases and metals than in the mid-ocean ridge.
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Two conditions usually required to allow vitrification are an increase of the viscosity and a decrease of the freezing temperature. Many solutes do both, but larger molecules generally have a larger effect, particularly on viscosity. Rapid cooling also promotes vitrification. For established methods of cryopreservation, the solute must penetrate the cell membrane in order to achieve increased viscosity and decrease freezing temperature inside the cell.
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Osmotic diuretics (e.g. mannitol) are substances that increase osmolarity but have limited tubular epithelial cell permeability. They work primarily by expanding extracellular fluid and plasma volume, therefore increasing blood flow to the kidney, particularly the peritubular capillaries. This reduces medullary osmolality and thus impairs the concentration of urine in the loop of Henle (which usually uses the high osmotic and solute gradient to transport solutes and water).
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Beads of sweat emerging from eccrine glands Sweat is mostly water. A microfluidic model of the eccrine sweat gland provides details on what solutes partition into sweat, their mechanisms of partitioning, and their fluidic transport to the skin surface. Dissolved in the water are trace amounts of minerals, lactic acid, and urea. Although the mineral content varies, some measured concentrations are: sodium (), potassium (), calcium (), and magnesium ().
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The temperature dependence of the soil hydraulic properties was included by considering the effects of temperature on surface tension, dynamic viscosity and the density of water. The heat transport equation in CHAIN_2D considered transport due to conduction and advection with flowing water. The solute transport equations considered advective-dispersive transport in the liquid phase, as well as diffusion in the gaseous phase. The transport equations also included provisions for nonlinear nonequilibrium reactions between the solid and liquid phases, linear equilibrium reactions between the liquid and gaseous phase, zero-order production and two first- order degradation reactions: one which was independent of other solutes, and one which provided the coupling between solutes involved in the sequential first-order decay reactions. The SWMS_2D and CHAIN_2D models formed the bases of versions 1.0 (for 16-bit Windows 3.1) and 2.0 (for 32-bit Windows 95) of HYDRUS-2D (Šimůnek et al.
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When light is absorbed by the retinal molecule, the molecule isomerises. This drives the protein to change shape and pump a proton across the membrane. The hydrogen ion gradient can then be used to generate ATP, transport solutes across the membrane, or drive a flagellar motor. One particular flavobacterium cannot reduce carbon dioxide using light, but uses the energy from its rhodopsin system to fix carbon dioxide through anaplerotic fixation.
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To survive in extremely salty environments, this archaeon—as with other halophilic Archaeal species—utilizes compatible solutes (in particular potassium chloride) to reduce osmotic stress. Potassium levels are not at equilibrium with the environment, so H. salinarum expresses multiple active transporters which pump potassium into the cell. At extremely high salt concentrations protein precipitation will occur. To prevent the salting out of proteins, H. salinarum encodes mainly acidic proteins.
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Solvents such as water can both donate and accept hydrogen bonds, making them excellent at solvating solutes that can donate or accept (or both) H-bonds. Some chemical compounds experience solvatochromism, which is a change in color due to solvent polarity. This phenomenon illustrates how different solvents interact differently with the same solute. Other solvent effects include conformational or isomeric preferences and changes in the acidity of a solute.
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Conservative solutes are often used as hydrologic tracers for water movement and transport. Both reactive and conservative stream water chemistry is foremost determined by inputs from the geology of its watershed, or catchment area. Stream water chemistry can also be influenced by precipitation, and the addition of pollutants from human sources. Large differences in chemistry do not usually exist within small lotic systems due to a high rate of mixing.
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Chaotropicity describes the entropic disordering of lipid bilayers and other biomacromolecules which is caused by substances dissolved in water. According to the original usage and work carried out on cellular stress mechanisms and responses, chaotropic substances do not necessarily disorder the structure of water. The chaotropic activities of solutes in the aqueous phase (e.g. ethanol, butanol, urea, MgCl2 and phenol) have been quantified using an agar- gelation assay.
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This may include velocity changes and turbulence in fluids and local tensile loads in solids and semi-solids. Lipids and other hydrophobic surfaces may reduce surface tension (blood vessel walls may have this effect). Dehydration may reduce gas solubility in a tissue due to higher concentration of other solutes, and less solvent to hold the gas. Another theory presumes that microscopic bubble nuclei always exist in aqueous media, including living tissues.
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Like all ductile iron, ADI is characterized by its spheroidal graphite nodules spaced within the matrix. These nodules reduce microsegregation of solutes within the material. For ADI, the material has been austempered such that the matrix is transformed into ausferrite, or a mixture of acicular ferrite and austenite. The microstructure is used to classify ADI into grades, which depend on the heat treatment process and not the composition of the material.
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Through the process of reabsorption, the majority of the fluid volume and solutes are transported from the urine to the blood. Next, secretion of materials from the renal epithelia into the urine occurs. Finally, urine as the end product travels to the ureters to be excreted. The kidneys of a common raven filter about eleven times its total body water daily, and more than 95% of the filtered water is reabsorbed.
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Although much research into mechanism of pre-eclampsia has taken place, its exact pathogenesis remains uncertain. Pre-eclampsia is thought to result from an abnormal placenta, the removal of which ends the disease in most cases. During normal pregnancy, the placenta vascularizes to allow for the exchange of water, gases, and solutes, including nutrients and wastes, between maternal and fetal circulations. Abnormal development of the placenta leads to poor placental perfusion.
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Dunaliella also serves as a very important model organism in understanding how algae adapts to and regulates itself in different salt concentrations. In fact, the idea for developing solutes to maintain osmotic balance in other organic matter originated from the osmoregulatory abilities of Dunaliella. D. salina and D. bardawil are also widely studied and currently used in biopharmaceuticals. An example includes nuclear transformations that led to the production HBsAg protein.
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The BIOMARUN model allows tracking of two substrates (or food), two microbial communities, and up to 8 solutes, and it was used to predict oil biodegradation under natural conditions (Geng et al. 2015) Geng, X., M. C. Boufadel, K. Lee, S. Abrams and M. Suidan (2015). "Biodegradation of subsurface oil in a tidally influenced sand beach: Impact of hydraulics and interaction with pore water chemistry." Water Resources Research.
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Clinical urine tests ( also known as urinalysis, UA) is an examination of urine for certain physical properties, solutes, cells, casts, crystals, organisms, or particulate matter, and mainly serves for medical diagnosis. The word is a blend of the words urine and analysis. Urine culture (a microbiological culture of urine) and urine electrolyte levels are part of urinalysis. There are three basic components to urinalysis: gross examination, chemical evaluation, and microscopic examination.
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John W. Hill, Ralph H. Petrucci, General Chemistry, 2nd edition, Prentice Hall, 1999. In liquid water at high temperatures, (e.g. that approaching the critical temperature), the solubility of ionic solutes tends to decrease due to the change of properties and structure of liquid water; the lower dielectric constant results in a less polar solvent and in a change of hydration energy affecting the ΔG of the dissolution reaction.
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Gaseous solutes exhibit more complex behavior with temperature. As the temperature is raised, gases usually become less soluble in water (exothermic dissolution reaction related to their hydration) (to minimum, which is below 120 °C for most permanent gases), but more soluble in organic solvents (endothermic dissolution reaction related to their solvatation). The chart shows solubility curves for some typical solid inorganic salts (temperature is in degrees Celsius i.e. kelvins minus 273.15).
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The resulting chronic edema is due to the breakdown of lymphatic clearance and the accumulation of interstitial solutes. In 2015, the presence of a meningeal lymphatic system was first identified. Downstream of the glymphatic system's waste clearance from the ISF to the CSF, the meningeal lymphatic system drains fluid from the glymphatic system to the meningeal compartment and deep cervical lymph nodes. The meningeal lymphatics also carry immune cells.
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High performance liquid chromatography or high pressure liquid chromatography is a form of chromatography applying high pressure to drive the solutes through the column faster. This means that the diffusion is limited and the resolution is improved. The most common form is "reversed phase" HPLC, where the column material is hydrophobic. The proteins are eluted by a gradient of increasing amounts of an organic solvent, such as acetonitrile.
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Root pressure is often high in some deciduous trees before they leaf out. Transpiration is minimal without leaves, and organic solutes are being mobilized so decrease the xylem water potential. Sugar maple accumulates high concentrations of sugars in its xylem early in the spring, which is the source of maple sugar. Some trees "bleed" xylem sap profusely when their stems are pruned in late winter or early spring, e.g.
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In fresh water, the osmolality (the concentration of solutes that contribute to a solution's osmotic pressure) in the plasma is much higher than it is in the surrounding water. The animals are well-hydrated, and the urine in the cloaca is abundant and dilute, nitrogen being excreted as ammonium bicarbonate.Grigg and Gans, pp. 333–334. Sodium loss is low and mainly takes place through the skin in freshwater conditions.
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Multilayer laminates have a structure similar to nacre, which provides mechanical strength at water free conditions. Helium cannot pass through the membranes in humidity free conditions, but penetrates easily when exposed to humidity, whereas water vapor passes with no resistance. Dry laminates are vacuum-tight, but immersed in water, they act as molecular sieves, blocking some solutes. A third project produced graphene sheets with subnanoscale (0.40 ± 0.24 nm) pores.
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The external factors involved in protein denaturation or disruption of the native state include temperature, external fields (electric, magnetic), molecular crowding, and even the limitation of space (i.e. confinement), which can have a big influence on the folding of proteins. High concentrations of solutes, extremes of pH, mechanical forces, and the presence of chemical denaturants can contribute to protein denaturation, as well. These individual factors are categorized together as stresses.
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Both limbs of the loop of Henle are lined with the simple squamous epithelium. Their main function is to regulate the levels of water and solutes in the primary urine. The basement membrane of the thin limb in humans has very uniform nodular thickenings that form a network that surrounds the tubule and acts as a support structure that is homologous to the collenchyma in plants. Smith, RA et al.
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This separation forces water and solutes to pass through the plasma membrane via a symplastic route in order to cross the endodermis layer. Casparian strips differentiate after an outward growth of the cortex is completed. At this level of the root development, the primary xylem of its vascular cylinder is only partly advanced. In gymnosperms and angiosperms displaying secondary growth, the roots commonly develop only endodermis with Casparian strips.
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In areas where the water is "hard" (that is, containing significant dissolved calcium salts), boiling decomposes the bicarbonate ions, resulting in partial precipitation as calcium carbonate. This is the "fur" that builds up on kettle elements, etc., in hard water areas. With the exception of calcium, boiling does not remove solutes of higher boiling point than water and in fact increases their concentration (due to some water being lost as vapour).
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A protic solvent is a solvent that has a hydrogen atom bound to an oxygen (as in a hydroxyl group), a nitrogen (as in an amine group), or fluoride (as in hydrogen fluoride). In general terms, any solvent that contains a labile H+ is called a protic solvent. The molecules of such solvents readily donate protons (H+) to solutes, often via hydrogen bonding. Water is the most common protic solvent.
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When a plant cell is placed in a solution that is hypotonic relative to the cytoplasm, water moves into the cell and the cell swells to become turgid. Osmosis is responsible for the ability of plant roots to draw water from the soil. Plants concentrate solutes in their root cells by active transport, and water enters the roots by osmosis. Osmosis is also responsible for controlling the movement of guard cells.
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Soluta is an extinct class of echinoderms that lived from the Middle Cambrian to the Early Devonian. The class is also known by its junior synonym Homoiostelea. Soluta is one of the four "carpoid" classes, alongside Ctenocystoidea, Cincta, and Stylophora, which made up the obsolete subphylum Homalozoa. Solutes (or solutans) were asymmetric animals with a stereom skeleton and two appendages, an arm extending anteriorly and a posterior appendage called a homoiostele.
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Thus each half of the protein forms 3.5 TMSs surrounding the channel. The structure explains why GlpF is selectively permeable to straight chain carbohydrates, and why water and ions are largely excluded. Aquaporin-1 (AQP1) and the bacterial glycerol facilitator, GlpF can transport O2, CO2, NH3, glycerol, urea, and water to varying degrees. For small solutes passing through AQP1, there is an anti-correlation between permeability and solute hydrophobicity.
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Ctenocystoidea is an extinct clade of echinoderms, which lived during the Cambrian and Ordovician periods. Unlike other echinoderms, ctenocystoids had bilateral symmetry, or were only very slightly asymmetrical. They are believed to be one of the earliest-diverging branches of echinoderms, with their bilateral symmetry a trait shared with other deuterostomes. Ctenocystoids were once classified in the taxon Homalozoa, also known as Carpoidea, alongside cinctans, solutes, and stylophorans.
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The solutes present in the aqueous phase are extracted by a complexation reaction with the extracting agent and transferred into the organic phase in which the formed complexes are soluble. The second step, known as stripping, is obtained by reversing the complexation reaction, where the solutes are back-extracted into another aqueous solution usually different in acidity compared to the previous one. The main goal is to develop reliable and affordable industrial separation processes by lipophilic and hydrophilic ligands to selectively extract minor actinides from the (3–4) M acidic target waste downstream of the PUREX process, but with the more challenging goal to minimize the amount of solid secondary waste. The CHON principle was born to meet this further process requirement, according to which all extractants and molecular reagents used in the developed processes have only to contain atoms of carbon (C), hydrogen (H), oxygen (O) and nitrogen (N), thus incinerable waste to easily release into the environment.
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His work appeared with the first issue, and a total of 120 of his articles were published by the journal, up until 1956. The death of Loeb in 1924 left a vacancy at the Rockefeller Institute, and Osterhout joined the staff in 1926. There he performed much productive research. During the 1930s, he was the first to suggest the active transport mechanism of a carrier molecule for moving solutes across a cell membrane.
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These additional solutes eventually lead to the formation of disinfection by-products (DBP's). The sieve baskets are easily removed daily for cleaning as is the sand unit, which should be back-washed at least once a week. A perfectly maintained consecutive dilution system drastically reduces the build-up of chloramines and other DBP's. The water returned to the pool should have been cleared of all organic waste above 10 microns in size.
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In liquid-state NMR spectroscopy, the sample to be studied is dissolved in a solvent. Typically, the concentration of the solvent is much higher than the concentration of the solutes of interest. The signal from the solvent can overwhelm that of the solute, and the NMR instrument may not collect any meaningful data. Solvent suppression techniques are particularly important in protein NMR where the solvent often includes H2O as well as D2O.
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2) that has been purified from oyster mushroom (Pleurotus ostreatus). These act in concert to perforate natural and artificial lipid membranes with high cholesterol and sphingomyelin contents. The complex has a 13-meric rosette-like structure with a central lumen that is ~ 4-5 nm in diameter. The opened transmembrane pore is non-selectively permeable to ions and smaller neutral solutes, and is a cause of cytolysis of a colloid-osmotic type.
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Water potential integrates a variety of different potential drivers of water movement, which may operate in the same or different directions. Within complex biological systems, many potential factors may be operating simultaneously. For example, the addition of solutes lowers the potential (negative vector), while an increase in pressure increases the potential (positive vector). If flow is not restricted, water will move from an area of higher water potential to an area that is lower potential.
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Although the northern springs contribute much less volume, their waters carry far greater concentrations of solutes and are important to the chemical composition of the lake. Below, the alternating beds of mud and halite extend at least in some places. In addition to common salt, it also has an abundance of carnallite (potassium magnesium chloride) in an area of and magnesium sulfate. The known beds are exposed at the surface or buried by of sedimentation.
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Haloferax volcanii grown in laboratory conditions and imaged using a phase contrast microscope. Cells were mounted on an agar pad. The membranes of this organism are made of the typical ether linked membrane lipids found solely in archaea and also contain a high level of carotenoids including lycopene, which gives them their distinctive red colour. H. volcanii use a salt in method to maintain osmostasis, rather than the typical compatible solutes method seen in bacteria.
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The contractile vacuole is a specialized type of vacuole that regulates the quantity of water inside a cell. In freshwater environments, the concentration of solutes is hypotonic, lesser outside than inside the cell. Under these conditions, osmosis causes water to accumulate in the cell from the external environment. The contractile vacuole acts as part of a protective mechanism that prevents the cell from absorbing too much water and possibly lysing (rupturing) through excessive internal pressure.
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The shells of testate amoebae may be composed of various substances, including calcium, silica, chitin, or agglutinations of found materials like small grains of sand and the frustules of diatoms. testate amoeba Difflugia acuminata. To regulate osmotic pressure, most freshwater amoebae have a contractile vacuole which expels excess water from the cell. This organelle is necessary because freshwater has a lower concentration of solutes (such as salt) than the amoeba's own internal fluids (cytosol).
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Solvent drag, also known as bulk transport, refers to solutes in the ultrafiltrate that are transported back from the renal tubule by the flow of water rather than specifically by ion pumps or other membrane transport proteins. Page 791 This is a phenomenon primarily in renal physiology, but it also occurs in gastrointestinal physiology. It generally occurs in the paracellular, rather than transcellular, pathway between the tubular cells. It is seen e.g.
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It is opposed by osmotic pressure (30 mmHg, 4.0 kPa) and hydrostatic pressure (20 mmHg, 2.7 kPa) of solutes present in capsular space. This difference in pressure is called effective pressure (25 mmHg, 3.3 kPa). In hemodialysis centers, ultrafiltration takes place in a hemofilter on the hemodialysis machines, when the blood pressure is greater than the dializate pressure (difference = transmembrane pressure (TMP)). This removes fluid from the blood while keeping its blood cells intact.
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Wallemia sebi can grow slowly on specialized fungal media with low water activity without additional solutes. On agar, W. sebi forms small brown colonies with a fine velvety texture, that have long rows of spores that may round up and become free at maturity. The colonies usually can grow to 2-2.5 millimeters, and sometimes to 4 to 5 millimeters in diameter. Wallemia sebi typically grow on MEA, MY50G, W-4 and W-10 agar.
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To achieve 0.6-0.84 water activity in food products, partial drying is employed for raw food that naturally have a high amount of humectants such as raisins, apricots, prunes and sultanas. Humectants are solutes (such as sugar or salt) that immobilize water in food. The drying process removes free water, and the humectants in the product bind the rest of the water, not allowing it to be utilized for chemical reactions or for microbial use.
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The continuity between the brain interstitial fluid and the CSF was confirmed by H. Cserr and colleagues from Brown University and Kings College London. The same group postulated that interstitial solutes in the brain parenchyma exchange with CSF via a bulk flow mechanism, rather than diffusion. However other work from this same laboratory indicated that the exchange of CSF with interstitial fluid was inconsistent and minor, contradicting the findings of Grady and colleagues.
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Opposition or criticisms against the hypothesis are often voiced. Some argue that mass flow is a passive process while sieve tube vessels are supported by companion cells. Hence, the hypothesis neglects the living nature of phloem. Moreover, it is found that amino acids and sugars (examples of organic solutes) are translocated at different rates, which is contrary to the assumption in the hypothesis that all materials being transported would travel at uniform speed.
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Lipid bilayers are generally impermeable to ions and polar molecules. The arrangement of hydrophilic heads and hydrophobic tails of the lipid bilayer prevent polar solutes (ex. amino acids, nucleic acids, carbohydrates, proteins, and ions) from diffusing across the membrane, but generally allows for the passive diffusion of hydrophobic molecules. This affords the cell the ability to control the movement of these substances via transmembrane protein complexes such as pores, channels and gates.
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This ability to replenish oxygen and other solutes at sediment depth allows for enhanced respiration by both bioturbators as well as the microbial community, thus altering estuarine elemental cycling. The marine nitrogen cycle. The effects of bioturbation on the nitrogen cycle are well-documented. Coupled denitrification and nitrification are enhanced due to increased oxygen and nitrate delivery to deep sediments and increased surface area across which oxygen and nitrate can be exchanged.
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They excrete highly concentrated urine which is approximately isosmotic to blood plasma, i.e. urine solute to plasma solute ratio is close to 1 (U/P≅1). Because of this, solely excreting urine is not sufficient to resolve the osmoregulatory problem in tunas. In turn, they excrete only the minimum volume of urine necessary to rid of solutes that are not excreted by other routes, and the salt is mostly excreted via gills.
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Scheme of selective permeability routes of epithelial cells (red arrows). The transcellular (through the cells) and paracellular (between the cells) routes control the passage of substances between the intestinal lumen and blood. This consists of specific transport of solutes across the epithelial cells. It is predominantly regulated by the activities of specialised transporters that translocate specific electrolytes, amino acids, sugars, short chain fatty acids and other molecules into or out of the cell.
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This is because slow diffusion of the solutes within the pores does not restrict the separation quality. The beads containing positively charged groups, which attract the negatively charged proteins, are commonly referred to as anion exchange resins. The amino acids that have negatively charged side chains at pH 7 (pH of water) are glutamate and aspartate. The beads that are negatively charged are called cation exchange resins, as positively charged proteins will be attracted.
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The Köhler curve is the visual representation of the Köhler equation. It shows the supersaturation at which the cloud drop is in equilibrium with the environment over a range of droplet diameters. The exact shape of the curve is dependent upon the amount and composition of the solutes present in the atmosphere. The Köhler curves where the solute is sodium chloride are different from when the solute is sodium nitrate or ammonium sulfate.
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The term diffusion pressure deficit (DPD) was coined by B.S Meyer in 1938. Originally DPD was described as suction pressure by Renner (1915). It is a reduction in the diffusion pressure of water in solution or cell over its pure state due to the presence of solutes in it and forces opposing diffusion. Diffusion pressure deficit or Diffusion pressure of pure water is maximum and its theoretical value is 1245.69 atm at STP.
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A rule-of-thumb is that any molecule that will dissolve in methanol or a less polar solvent is compatible with SFC, including polar solutes. CO2 has polarity similar to n-heptane at its critical point, but the solvent strength can be increased by increasing density or using a polar cosolvent. In practice, when the fraction of cosolvent is high, the mobile phase is not truly supercritical, but this terminology is used regardless.
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Osmoprotectants or compatible solutes are small organic molecules with neutral charge and low toxicity at high concentrations that act as osmolytes and help organisms survive extreme osmotic stress. Osmoprotectants can be placed in three chemical classes: betaines and associated molecules, sugars and polyols, and amino acids. These molecules accumulate in cells and balance the osmotic difference between the cell's surroundings and the cytosol. In plants, their accumulation can increase survival during stresses such as drought.
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Excessive ADH causes an inappropriate increase in the reabsorption in the kidneys of solute-free water ("free water"): excess water moves from the distal convoluted tubules (DCT)s and collecting tubules of the nephrons - via activation of aquaporins, the site of the ADH receptors - back into the circulation. This has two consequences. First, in the extracellular fluid (ECF) space, there is a dilution of blood solutes, causing hypoosmolality, including a low sodium concentration - hyponatremia.
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Greenwood and Earnshaw, p. 1074 Ruthenium, like the other platinum group metals, is obtained commercially as a by-product from nickel, and copper, and platinum metals ore processing. During electrorefining of copper and nickel, noble metals such as silver, gold, and the platinum group metals precipitate as anode mud, the feedstock for the extraction. The metals are converted to ionized solutes by any of several methods, depending on the composition of the feedstock.
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Each works effectively for separating analytes by relative polar differences. HILIC bonded phases have the advantage of separating acidic, basic and neutral solutes in a single chromatographic run. from review The polar analytes diffuse into a stationary water layer associated with the polar stationary phase and are thus retained. The stronger the interactions between the polar analyte and the polar stationary phase (relative to the mobile phase) the longer the elution time.
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H. halophila could play a strong role in hydrogen generation, as hydrogen gas is a byproduct of the nitrogen fixation catalyzed by its nitrogenase. H. halophila also serves in the production of organic solutes such as glycine, betaine, ectoine, and trehalose. Photoactive yellow protein, PYP, is a blue- light sensor from the bacterium H. halophila. Photoactive proteins such as PYP are generally accepted as model systems for studying protein signal state formation.
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In soil, macropores are defined as cavities that are larger than 75 μm. Functionally, pores of this size host preferential soil solution flow and rapid transport of solutes and colloids. Macropores increase the hydraulic conductivity of soil, allowing water to infiltrate and drain quickly, and shallow groundwater to move relatively rapidly via lateral flow. In soil, macropores are created by plant roots, soil cracks, soil fauna, and by aggregation of soil particles into peds.
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Tight junctions, also known as occluding junctions or zonulae occludentes (singular, zonula occludens) are multiprotein junctional complexes whose general function is to prevent leakage of transported solutes and water and seals the paracellular pathway. Tight junctions may also serve as leaky pathways by forming selective channels for small cations, anions, or water. Tight junctions are present mostly in vertebrates (with the exception of Tunicates). The corresponding junctions that occur in invertebrates are septate junctions.
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Phenomena which can cause damage to cells during cryopreservation mainly occur during the freezing stage, and include: solution effects, extracellular ice formation, dehydration and intracellular ice formation. Many of these effects can be reduced by cryoprotectants. Once the preserved material has become frozen, it is relatively safe from further damage. ; Solution effects: As ice crystals grow in freezing water, solutes are excluded, causing them to become concentrated in the remaining liquid water.
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Tight junction proteins (TJ proteins) are molecules situated at the tight junctions of epithelial, endothelial and myelinated cells. This mutliprotein junctional complex has a regulatory function in passage of ions, water and solutes through the paracellular pathway. It can also coordinate the motion of lipids and proteins between the apical and basolateral surfaces of the plasma membrane. Thereby tight junction conducts signaling molecules, that influence the differentiation, proliferation and polarity of cells.
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This TJ protein also participate in a selective diffusion of solutes along concentration gradient and transmigration of leukocytes across the endothelium and epithelium. Therefore the result of the overexpression of mutant occludin in epithelial cells leads to break down the barrier function of tight junction and changes in a migration of neutrophils. Occludin cooperates with members of the claudin family directly or indirectly and together they form the long strands of tight junction.
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The blood contains the copper-rich protein hemocyanin, which is used for oxygen transport at low ocean temperatures and low oxygen concentrations, and makes the oxygenated blood a deep, blue color. As systemic blood returns via two vena cavae to the branchial hearts, excretion of urine, carbon dioxide, and waste solutes occurs through outpockets (called nephridial appendages) in the vena cavae walls that enable gas exchange and excretion via the mantle cavity seawater.
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Other things being equal, compounds that readily donate hydrons (Brønsted acids, see below) are generally polar, hydrophilic solutes and are often soluble in solvents with high relative static permittivity (dielectric constants). Examples include organic acids like acetic acid (CH3COOH) or methanesulfonic acid (CH3SO3H). However, large nonpolar portions of the molecule may attenuate these properties. Thus, as a result of its alkyl chain, octanoic acid (C7H15COOH) is considerably less hydrophilic compared to acetic acid.
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In most binary systems, alloying above a concentration given by the phase diagram will cause the formation of a second phase. A second phase can also be created by mechanical or thermal treatments. The particles that compose the second phase precipitates act as pinning points in a similar manner to solutes, though the particles are not necessarily single atoms. The dislocations in a material can interact with the precipitate atoms in one of two ways (see Figure 2).
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The main intravascular fluid in mammals is blood, a complex mixture with elements of a suspension (blood cells), colloid (globulins), and solutes (glucose and ions). The blood represents both the intracellular compartment (the fluid inside the blood cells) and the extracellular compartment (the blood plasma). The average volume of plasma in the average () male is approximately . The volume of the intravascular compartment is regulated in part by hydrostatic pressure gradients, and by reabsorption by the kidneys.
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Historically, the theory was used to model nonuniform adsorbates and multi-components solutes. For certain pairs of adsorbates and adsorbents, the mathematical parameters of the Polyani theory can be related to the physicochemical properties of both adsorbents and adsorbates. The theory has been used to model the adsorption of carbon nanotubes and carbon nanoparticles. In the study done by Yang and Xing, the theory have been shown to better fit the adsorption isotherm than Langmuir, Freundlich, and partition.
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Octopus vulgaris will reduce the amount of ammonia excreted in order to use the excess solutes that it would have otherwise excreted due to the increased metabolic rate. Octopuses do not regulate their internal temperatures until it reaches a threshold where they must begin to regulate to prevent death. The increase in metabolic rate shown with increasing temperatures is likely due to the octopus swimming to shallower or deeper depths to stay within its preferential temperature zone.
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Claudin-14 is a protein that in humans is encoded by the CLDN14 gene. It belongs to a related family of proteins called claudins. The protein encoded by CLDN14 is an integral membrane protein and a component of tight junctions, one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets. Tight junctions form continuous seals around cells and serve as a physical barrier to prevent solutes and water from passing freely through the paracellular space.
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Very aggressive environments require novel materials approaches in order to combat declines in mechanical properties over time. One method researchers have sought to use is introducing features to stabilize displaced atoms. This can be done by adding grain boundaries, oversized solutes, or small oxide dispersants to minimize defect movement. By doing this, there would be less radiation-induced segregation of elements, which would in turn lead to more ductile grain boundaries and less intergranular stress corrosion cracking.
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The name is also used for compounds that can be viewed as result of substituting various functional groups for the hydrogen atoms in such a molecule, as well as similar molecules with one or more double bonds in the ring. Cyclitols and their derivatives are some of the compatible solutes which are formed in a plant as a response to salt or water stress. Some cyclitols (e.g. quinic or shikimic acid) are parts of hydrolysable tannins.
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Its importance can be measured by the many and continuing citations it has received and its use by other. She applied this simple model to solvation dynamics in confined environments, predicting that chromophore- surfactant interactions can lead to dramatically different results for solutes that repelled by and attracted to the surfactant layer. She also showed that solute motion relative to the interface plays a role, opening up a relaxation channel that is absent in bulk liquids.
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Alpine habitat on thumb Most alpine plants are faced with low temperature extremes at some point in their lives. There are a number of ways that a plant can survive these extremes. Plants can avoid exposure to low temperature by using different forms of seasonal phenology, morphology, or by variable growth form preference. They can also avoid the freezing of their exposed tissues by increasing the amount of solutes in their tissues, known as freezing-point depression.
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Second, this stops the uptake of any further K+ into the cells and, subsequently, the loss of K+. The loss of these solutes causes an increase in water potential, which results in the diffusion of water back out of the cell by osmosis. This makes the cell plasmolysed, which results in the closing of the stomatal pores. Guard cells have more chloroplasts than the other epidermal cells from which guard cells are derived. Their function is controversial.
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In chemical separation terminology, the raffinate (from French raffiner, to refine) is a product which has had a component or components removed. The product having the removed materials is referred to as the extract. For example, in solvent extraction, the raffinate is the liquid stream which remains after solutes from the original liquid are removed through contact with an immiscible liquid. In metallurgy, raffinating refers to a process in which impurities are removed from liquid material.
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The secondary constituents are often called solutes. If there is a mixture of only two types of atoms (not counting impurities) such as a copper-nickel alloy, then it is called a binary alloy. If there are three types of atoms forming the mixture, such as iron, nickel and chromium, then it is called a ternary alloy. An alloy with four constituents is a quaternary alloy, while a five-part alloy is termed a quinary alloy.
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The apoplastic pathway is one of the two main pathways for water transport in plants, the other being symplastic pathway. In apoplastic transport, water and minerals flow in an upward direction via the apoplast to the xylem in the root. The concentration of solutes transported in aboveground organs is established through a combination of import from the xylem, absorption by cells, and export by the phloem. Transport velocity is higher in the apoplast than the symplast.
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He was recognised for his expertise on translocation and published around 30 papers about vegetative reproduction, translocation, temperature and water relations of plants. He was the author of the monograph The Translocation of Solutes in Plants in 1935 that, through critical review, encouraged further research in this area. He also posthumously co-authored An Introduction to Plant Physiology with D. G. Clark. Upon his death he was survived by his widow, two sons, a daughter, and six grandchildren.
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The ionization of solutes occurred by direct evaporation or ion- molecule reactions induced by the solvent. This interface was able to handle up to 2 ml/min of eluate from the LC column and would efficiently introduce it into the MS vacuum system. TSP was also more suitable for LC-MS applications involving reversed phase liquid chromatography (RT-LC). The TSP system had a dual function acting as an interface and a solvent-mediated chemical ionization source.
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NKCC1 is widely distributed throughout the body, especially in organs that secrete fluids, called exocrine glands. In cells of these organs, NKCC1 is commonly found in the basolateral membrane, the part of the cell membrane closest to the blood vessels. Its basolateral location gives NKCC1 the ability to transport sodium, potassium, and chloride from the blood into the cell. Other transporters assist in the movement of these solutes out of the cell through its apical surface.
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Homalozoans were traditionally considered to be stem-group echinoderms, \- pages 401-404 but had also been considered to lie in the stem lineage of the chordates (calcichordates). However, it is now generally accepted that homalozoans were echinoderms because their calcite skeleton was composed of the typical stereom crystalline structure. They include the unusual stylophorans (mitrates and cornutes), Homoiostelea (solutes), the Homostelea (cinctans), and the Ctenocystoidea (ctenoid-bearing homalozoans). They have recently been recognised as a polyphyletic group.
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Compatible solutes have a functional role in agriculture. In high stress conditions, such as drought or high salinity, plants that naturally create or take up osmoprotectants show increased survival rates. By inducing expression or uptake of these molecules in crops in which they are naturally not present, there is an increase in the areas in which they are able to be grown. One documented reason for increased growth is regulation of toxic reactive oxygen species (ROS).
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The time that it takes for the liquid to flow through the capillary from one reservoir to the other is an indication of the viscosity of the liquid. Using a reference solution, the viscosity of the liquid can be quantified. Ostwald typically used this device to study the behavior of solutes in water solutions. These devices came to be known as Ostwald viscometers and are in widespread use in contemporary times for research and quality control purposes.
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Sugars do not readily permeate through the membrane. Those solutes that do, such as dimethyl sulfoxide, a common cryoprotectant, are often toxic in intense concentration. One of the difficult compromises of vitrifying cryopreservation concerns limiting the damage produced by the cryoprotectant itself due to cryoprotectant toxicity. Mixtures of cryoprotectants and the use of ice blockers have enabled the Twenty-First Century Medicine company to vitrify a rabbit kidney to −135 °C with their proprietary vitrification mixture.
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SIRs can be reused for different separation tasks by just rinsing one complexing agent out and re-impregnating them with another more suitable extractant. This way, potentially expensive design and production steps of e.g. affinity resins can be avoided. Finally, by filling the whole volume of the particle pores with an extractant (complexing agent), a higher capacity for solutes can be achieved than with ordinary adsorption or ion exchange resins, where only the surface area is available.
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At about 1.15 metres of water pressure, the water is filtered through the membrane with a pore size of 20 to 100 nm. The device removes bacteria with an efficiency of 99.999% (measurement Institut Fresenius, E. coli and Coliform) and viruses to 99.9% (measured Bonn University, coliphages). A system based on ultrafiltration system (unlike Reverse osmosis based units) is not able to filter out solutes like salts or liquids like mineral oils. They pass through the membrane.
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The blood tests allow for the detection of different solutes in the plasma, as well as the glucose levels. Moreover, further laboratory tests will measure ketone levels as an indication of ketosis. A high ketone count is found in the urine samples means that the body is sourcing its energy through the burning of fat at a fast rate, turning fatty acids into ketones. High blood sugar levels may cause a decrease in sodium levels, which is another potential indicator of hyperosmolar syndrome.
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Vertebrates originated in fresh water, where water was drawn into their bodies by the osmotic pressure of their body fluids. Their kidneys excreted the extra water while also retrieving their supply of small solutes. He concludes with an admiring discussion of another of his interests: how rapidly the piano can be played by an educated nervous system sustained by the kidneys. He also served on the board of trustees of Science Service, now known as Society for Science & the Public, from 1952–1955.
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Function of symporters and antiporters. In an antiporter two species of ion or other solutes are pumped in opposite directions across a membrane. One of these species is allowed to flow from high to low concentration which yields the entropic energy to drive the transport of the other solute from a low concentration region to a high one. An example is the sodium-calcium exchanger or antiporter, which allows three sodium ions into the cell to transport one calcium out.
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Since a variety of systems have been investigated, a study was done to investigate the individual adsorption of a mixed solution. This phenomenon is also called competitive adsorption because solutes tend to compete for the same adsorption sites. In the experiment conducted by Rosene and Manes, the competitive adsorption of glucose, urea, benzoic acid, phthalide, and p-nitrophenol. Using the Polanyi adsorption model, they were able to calculate the relative adsorption of each compound onto the surface of activated carbon.
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Plasma and interstitial fluid are very similar because water, ions, and small solutes are continuously exchanged between them across the walls of capillaries, through pores and capillary clefts. Interstitial fluid consists of a water solvent containing sugars, salts, fatty acids, amino acids, coenzymes, hormones, neurotransmitters, white blood cells and cell waste-products. This solution accounts for 26% of the water in the human body. The composition of interstitial fluid depends upon the exchanges between the cells in the biological tissue and the blood.
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Sweat diagnostics is an emerging non-invasive technique used to provide insights to the health of the human body. Common sweat diagnostic tests include testing for cystic fibrosis and illicit drugs. Most testing of human sweat is in reference to the eccrine sweat gland which in contrast to the apocrine sweat gland, has a lower composition of oils. Although sweat is mostly water, there are many solutes which are found in sweat that have at least some relation to biomarkers found in blood.
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Death Valley, Spring 2005: ephemeral Lake Badwater in the flooded Badwater Basin An endorheic lake, or sink lake, is a collection of water within an endorheic basin, or sink, with no evident outlet. Endorheic lakes are generally saline as a result of being unable to get rid of solutes left in the lake by evaporation. These lakes can be used as indicators of anthropogenic change, such as irrigation or climate change, in the areas surrounding them. Lakes with subsurface drainage are considered cryptorheic.
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Tempering methods for alloy steels may vary considerably, depending on the type and amount of elements added. In general, elements like manganese, nickel, silicon, and aluminum will remain dissolved in the ferrite during tempering while the carbon precipitates. When quenched, these solutes will usually produce an increase in hardness over plain carbon- steel of the same carbon content. When hardened alloy-steels, containing moderate amounts of these elements, are tempered, the alloy will usually soften somewhat proportionately to carbon steel.
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The chvE-gguAB gene in Agrobacterium tumefaciens encodes glucose and galactose importers that are also associated with virulence. Transporters are extremely vital in cell survival such that they function as protein systems that counteract any undesirable change occurring in the cell. For instance, a potential lethal increase in osmotic strength is counterbalanced by activation of osmosensing ABC transporters that mediate uptake of solutes. Other than functioning in transport, some bacterial ABC proteins are also involved in the regulation of several physiological processes.
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The solubility of a substance is an entirely different property from the rate of solution, which is how fast it dissolves. The smaller a particle is, the faster it dissolves although there are many factors to add to this generalization. Crucially, solubility applies to all areas of chemistry, geochemistry, inorganic, physical, organic and biochemistry. In all cases it will depend on the physical conditions (temperature, pressure and concentration) and the enthalpy and entropy directly relating to the solvents and solutes concerned.
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Cotransporters are capable of moving solutes either up or down gradients at rates of 1000 to 100000 molecules per second. They may act as channels or transporters, depending on conditions under which they are assayed. The movement occurs by binding to two molecules or ions at a time and using the gradient of one solute's concentration to force the other molecule or ion against its gradient. Some studies show that cotransporters can function as ion channels, contradicting the classical models.
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Diabetic ketoacidosis arises because of a lack of insulin in the body. The lack of insulin and corresponding elevation of glucagon leads to increased release of glucose by the liver (a process that is normally suppressed by insulin) from glycogen via glycogenolysis and also through gluconeogenesis. High glucose levels spill over into the urine, taking water and solutes (such as sodium and potassium) along with it in a process known as osmotic diuresis. This leads to polyuria, dehydration, and polydipsia.
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The interstitium is a contiguous fluid-filled space existing between a structural barrier, such as a cell wall or the skin, and internal structures, such as organs, including muscles and the circulatory system. The fluid in this space is called interstitial fluid, comprises water and solutes, and drains into the lymph system. The interstitial compartment is composed of connective and supporting tissues within the body - called the extracellular matrix - that are situated outside the blood and lymphatic vessels and the parenchyma of organs.
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Chromatographic response function, often abbreviated to CRF, is a coefficient which measures the quality of the separation in the result of a chromatography. The CRF concept have been created during the development of separation optimization, to compare the quality of many simulated or real chromatographic separations. Many CRFs have been proposed and discussed. In high performance liquid chromatography the CRF is calculated from various parameters of the peaks of solutes (like width, retention time, symmetry etc.) are considered into the calculation.
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The majority of the common ostrich's internal solutes are made up of sodium ions (Na+), potassium ions (K+), chloride ions (Cl-), total short-chain fatty acids (SCFA), and acetate. The caecum contains a high water concentration with reduced levels nearing the terminal colon, and exhibits a rapid fall in Na+ concentrations and small changes in K+ and Cl-. The colon is divided into three sections and take part in solute absorption. The upper colon largely absorbs Na+ and SCFA, and partially absorbs KCl.
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The Severinghaus electrode is an electrode that measures carbon dioxide (CO2). It was developed by Dr. John W. Severinghaus and his technician A. Freeman Bradley in 1958. It utilizes a CO2-sensitive glass electrode in a surrounding film of bicarbonate solution covered by a thin plastic carbon dioxide permeable membrane, but impermeable to water and electrolytic solutes. The carbon dioxide pressure of a sample gas or liquid equilibrates through the membrane and the glass electrode measures the resulting pH of the bicarbonate solution.
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Primary purification is then done by forcing water through a membrane with very tiny pores, a so-called reverse osmosis membrane. This lets the water pass, but holds back even very small solutes such as electrolytes. Final removal of leftover electrolytes is done by passing the water through a tank with ion-exchange resins, which remove any leftover anions or cations and replace them with hydroxyl and hydrogen ions, respectively, leaving ultrapure water. Even this degree of water purification may be insufficient.
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The glomerulus is the network known as a tuft, of filtering capillaries located at the vascular pole of the renal corpuscle in Bowman's capsule. Each glomerulus receives its blood supply from an afferent arteriole of the renal circulation. The glomerular blood pressure provides the driving force for water and solutes to be filtered out of the blood plasma, and into the interior of Bowman's capsule, called Bowman's space. Only about a fifth of the plasma is filtered in the glomerulus.
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These surfaces are the vertebral endplates which are in direct contact with the intervertebral discs and form the joint. The endplates are formed from a thickened layer of the cancellous bone of the vertebral body, the top layer being more dense. The endplates function to contain the adjacent discs, to evenly spread the applied loads, and to provide anchorage for the collagen fibers of the disc. They also act as a semi-permeable interface for the exchange of water and solutes.
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Stool osmotic gap is a measurement of the difference in solute types between serum and feces, used to distinguish among different causes of diarrhea. Feces is normally in osmotic equilibrium with blood serum, which the human body maintains between 290–300 mOsm/kg. However, the solutes contributing to this total differ. Serum is mostly sodium and potassium salts (as reflected in the formulas for serum osmol gap and anion gap), while the digestive tract contains significant amounts of other compounds.
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In materials, the motion of dislocations is a discontinuous process. When dislocations meet obstacles during plastic deformation (such as particles or forest dislocations), they are temporarily arrested for a certain time. During this time, solutes (such as interstitial particles or substitutional impurities) diffuse around the pinned dislocations, further strengthening the obstacles' hold on the dislocations. Eventually these dislocations will overcome the obstacles with sufficient stress and will quickly move to the next obstacle where they are stopped and the process can repeat.
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Turgor pressure within cells is regulated by osmosis and this also causes the cell wall to expand during growth. Along with size, rigidity of the cell is also caused by turgor pressure; a lower pressure results in a wilted cell or plant structure (i.e. leaf, stalk). One mechanism in plants that regulate turgor pressure is its semipermeable membrane, which only allows some solutes to travel in and out of the cell, which can also maintain a minimum amount of pressure.
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The morphology of subglacial lakes has the potential to change their hydrology and circulation patterns. Areas with the thickest overlying ice experience greater rates of melting. The opposite occurs in areas where the ice sheet is thinnest, which allows re-freezing of lake water to occur. These spatial variations in melting and freezing rates lead to internal convection of water and circulation of solutes, heat, and microbial communities throughout the subglacial lake, which will vary among subglacial lakes of different regions.
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The factor it displaces, I-TAC, is a T-cell attractant. This peptide may also be involved in increased risk for type 1 diabetes as zonulin production is also a factor. This triggering of zonulin ultimately results in the degradation of tight junctions allowing large solutes, such as proteolytic resistant gliadin fragments to enter behind the brush border membrane cells. One study examined the effect of ω-5 gliadin, the primary cause of WD-EIA, and found increased permeability of intestinal cells.
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Kt/V has been criticized because quite high levels can be achieved, particularly in smaller patients, during relatively short dialysis sessions. This is especially true for small people, where "adequate" levels of Kt/V often can be achieved over 2 to 2.5 hours. One important part of dialysis adequacy has to do with adequate removal of salt and water, and also of solutes other than urea, especially larger molecular weight substances and phosphorus. Phosphorus and similar molecular weights remain elusive to filtration of any degree.
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Active transport occurs apoplastically and does not use plasmodesmata. An intermediate type of loading exists that uses symplastic transport but utilizes a size-exclusion mechanism to ensure diffusion is a one-way process between the mesophyll and phloem cells. This process is referred to as polymer-trapping, in which simple solutes such as sucrose are synthesized into larger molecules such as stachyose or raffinose in intermediary cells. The larger molecules cannot diffuse back to the mesophyll but can move into the phloem's sieve cells.
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Implicit solvent models such as PB, GB, and SASA lack the viscosity that water molecules impart by randomly colliding and impeding the motion of solutes through their van der Waals repulsion. In many cases, this is desirable because it makes sampling of configurations and phase space much faster. This acceleration means that more configurations are visited per simulated time unit, on top of whatever CPU acceleration is achieved in comparison to explicit solvent. It can, however, lead to misleading results when kinetics are of interest.
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The helium experiments, started with students S. Goyal and D. Schutt, provided the first molecular spectra of solutes in liquid helium, a unique superfluid solvent [7]. Frank Stienkemeier joined the group as a postdoc and together with graduate students John Higgins and Carlo Callegari (and sabbatical visitor Wolfgang Ernst) established the “Alkali age” of the group which provided a rich vein to explore chemical dynamics in this fascinating state of mater [8]. Graduate student James Reho brought time resolved spectroscopy techniques into the mix [9].
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Unlike animal cells, almost every plant cell is surrounded by a polysaccharide cell wall. Neighbouring plant cells are therefore separated by a pair of cell walls and the intervening middle lamella, forming an extracellular domain known as the apoplast. Although cell walls are permeable to small soluble proteins and other solutes, plasmodesmata enable direct, regulated, symplastic transport of substances between cells. There are two forms of plasmodesmata: primary plasmodesmata, which are formed during cell division, and secondary plasmodesmata, which can form between mature cells.
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Origin of diderm (Gram-negative) bacteria: antibiotic selection pressure rather than endosymbiosis likely led to the evolution of bacterial cells with two membranes. Antonie van Leeuwenhoek. 100:171-182. In diderm bacteria, the periplasm contains a thin cell wall composed of peptidoglycan. In addition, it includes solutes such as ions and proteins, which are involved in wide variety of functions ranging from nutrient binding, transport, folding, degradation, substrate hydrolysis, to peptidoglycan synthesis, electron transport, and alteration of substances toxic to the cell (xenobiotic metabolism).
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The descending portion of the loop of Henle is extremely permeable to water and is less permeable to ions, therefore water is easily reabsorbed here and solutes are not readily reabsorbed. The 300 mOsm/L fluid from the loop loses water to the higher concentration outside the loop and increases in tonicity until it reaches its maximum at the bottom of the loop. This area represents the highest concentration in the nephron, but the collecting duct can reach this same tonicity with maximum ADH effect.
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Membrane filtration processes can be distinguished by three major characteristics: driving force, retentate stream and permeate streams. The microfiltration process is pressure driven with suspended particles and water as retentate and dissolved solutes plus water as permeate. The use of hydraulic pressure accelerates the separation process by increasing the flow rate (flux) of the liquid stream but does not affect the chemical composition of the species in the retentate and product streams.Cheryan, M 1998, Fouling and Cleaning in Ultrafiltration and Microfiltration Handbook 2nd edn.
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Once inside the cytoplasm, pinocytic vacuoles combine with each other and with lysosomes to form large vacuoles that appear transparent under microscopic examination. There may be no symptomatic presentation with this condition, or it may confused with other nephrotic conditions such as Tubular calcineurin-inhibitor toxicity. Affected cells of the proximal tubule may be passed in the urine, but a kidney biopsy is the only sure way to make a diagnosis. Responsible exogenous solutes include sucrose-containing IVIg, mannitol, dextran, contrast dye, and hydroxyethyl starch.
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Different connexins may exhibit differing specificities for solutes. For example, adenosine passed about 12-fold better through channels formed by Cx32 while AMP and ADP passed about 8-fold better, and ATP greater than 300-fold better, through channels formed by Cx43. Thus, addition of phosphate to adenosine appears to shift its relative permeability from channels formed by Cx32 to channels formed by Cx43. This may have functional consequence because the energy status of a cell could be controlled via connexin expression and channel formation.
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The apoplastic and symplastic pathways Inside a plant, the apoplast is the space outside the plasma membrane within which material can diffuse freely. It is interrupted by the Casparian strip in roots, by air spaces between plant cells and by the plant cuticle. Structurally, the apoplast is formed by the continuum of cell walls of adjacent cells as well as the extracellular spaces, forming a tissue level compartment comparable to the symplast. The apoplastic route facilitates the transport of water and solutes across a tissue or organ.
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This is why the composition of solutes in urine differs significantly from that of the blood plasma. Urine has a high concentration of divalent ions, such as Mg2+ and SO42− (U/P>>1), as these ions are mostly excreted by the kidneys keeping their concentration in blood plasma from rising. Monovalent ions (Na+, Cl−, K+) are excreted by the gills, so their U/P ratios in the urine are below 1. The excretion of inorganic ions by structures other than kidneys is called the extrarenal salt excretion.
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Solutes that are transported by the various SLC group members are extremely diverse and include both charged and uncharged organic molecules as well as inorganic ions and the gas ammonia. As is typical of integral membrane proteins, SLCs contain a number of hydrophobic transmembrane alpha helices connected to each other by hydrophilic intra- and extra-cellular loops. Depending on the SLC, these transporters are functional as either monomers or obligate homo- or hetero-oligomers. Many SLC families are members of the major facilitator superfamily.
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According to the so-called in silico method quantum cluster equilibrium (QCE) theory of liquids W8 clusters dominate the liquid water bulk phase followed by W5 and W6 clusters. In order to facilitate a water triple point the presence of a W24 cluster is invoked. In another model bulk water is built up from a mixture of hexamer and pentamer rings containing cavities capable of enclosing small solutes. In yet another model an equilibrium exists between a cubic water octamer and two cyclic tetramers.
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A pKa value obtained in a mixed solvent cannot be used directly for aqueous solutions. The reason for this is that when the solvent is in its standard state its activity is defined as one. For example, the standard state of water:dioxane mixture with 9:1 mixing ratio is precisely that solvent mixture, with no added solutes. To obtain the pKa value for use with aqueous solutions it has to be extrapolated to zero co-solvent concentration from values obtained from various co-solvent mixtures.
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Claudin-16 is a protein that in humans is encoded by the CLDN16 gene. It belongs to the group of claudins. Tight junctions represent one mode of cell- to-cell adhesion in epithelial or endothelial cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the paracellular space. These junctions are composed of sets of continuous networking strands in the outwardly facing cytoplasmic leaflet, with complementary grooves in the inwardly facing extracytoplasmic leaflet.
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In the case where the desired product is fresh water that does not contain draw solutes, a second separation step is required. The first separation step of FO, driven by an osmotic pressure gradient, does not require a significant energy input (only unpressurized stirring or pumping of the solutions involved). The second separation step, however does typically require energy input. One method used for the second separation step is to employ RO. This approach has been used, for instance, in the treatment of landfill leachate.
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Prof. Maroncelli's research interests include solvation and solvent effects on chemical reaction, liquid- phase dynamics, electron and proton transfer reactions, supercritical fluids and expanded liquids, ionic liquids, ultrafast spectroscopy, and computer simulation. Maroncelli’s research seeks to develop a fundamental understanding of the molecular nature of solvation and how it affects chemical reactions taking place in solution. Solvation involves the interactions between dissolved molecules (solutes) and molecules of the solvent. Favorable arrangements of solvent molecules around the solute lower its energy, which leads to dissolution.
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Stylised diagram of the last part of the insect's digestive tract showing malpighian tubule (Orthopteran type) The Malpighian tubule system is a type of excretory and osmoregulatory system found in some insects, myriapods, arachnids, and tardigrades. The system consists of branching tubules extending from the alimentary canal that absorbs solutes, water, and wastes from the surrounding hemolymph. The wastes then are released from the organism in the form of solid nitrogenous compounds and calcium oxalate. The system is named after Marcello Malpighi, a seventeenth-century anatomist.
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Complex cycling systems of Malpighian tubules have been described in other insect orders. Hemipteran insects use tubules that permit movement of solutes into the distal portion of the tubules while reabsorption of water and essential ions directly to the hemolymph occurs in the proximal portion and the rectum. Both Coleoptera and Lepidoptera use a cryptonephridial arrangement where the distal end of the tubules are embedded in fat tissue surrounding the rectum. Such an arrangement may serve to increase the efficiency of solute processing in the Malpighian tubules.
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Something which reduces surface tension, or adsorbs gas molecules, or locally reduces solubility of the gas, or causes a local reduction in static pressure in a fluid may result in a bubble nucleation or growth. This may include velocity changes and turbulence in fluids and local tensile loads in solids and semi-solids. Lipids and other hydrophobic surfaces may reduce surface tension (blood vessel walls may have this effect). Dehydration may reduce gas solubility in a tissue due to higher concentration of other solutes, and less solvent to hold the gas.
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Antidiuretic hormone (ADH) deficiency leads to the syndrome of diabetes insipidus (unrelated to diabetes mellitus): inability to concentrate the urine, leading to polyuria (production of large amounts of clear urine) that is low in solutes, dehydration and—in compensation—extreme thirst and constant need to drink (polydipsia), as well as hypernatremia (high sodium levels in the blood). ADH deficiency may be masked if there is ACTH deficiency, with symptoms only appearing when cortisol has been replaced. Oxytocin (OXT) deficiency generally causes few symptoms, as it is only required at the time of childbirth and breastfeeding.
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Plants with few or absent plasmodesmata are usually active loaders since they do not have a way for solutes to pass through the symplast. In 2001, Robert Turgeon and colleagues found that plasmodesmatal frequency is not the sole indicator of a plant's phloem-loading strategy. While the presence of abundant plasmodesmata does allow for passive, symplastic transport, it does not exclude the possibility of active, apoplastic transport. The amount of plasmodesmata in a leaf is an aspect of a species' anatomy and not necessarily a determinant of phloem- loading strategy.
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The extracellular fluids may be divided into three types: interstitial fluid in the "interstitial compartment" (surrounding tissue cells and bathing them in a solution of nutrients and other chemicals), blood plasma and lymph in the "intravascular compartment" (inside the blood vessels and lymphatic vessels), and small amounts of transcellular fluid such as ocular and cerebrospinal fluids in the "transcellular compartment". The interstitial and intravascular compartments readily exchange water and solutes but the third extracellular compartment, the transcellular, is thought of as separate from the other two and not in dynamic equilibrium with them.
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The acutely toxic dose of aspirin is generally considered greater than 150 mg per kg of body mass. Moderate toxicity occurs at doses up to 300 mg/kg, severe toxicity occurs between 300 and 500 mg/kg, and a potentially lethal dose is greater than 500 mg/kg. Chronic toxicity may occur following doses of 100 mg/kg per day for two or more days. Monitoring of biochemical parameters such as electrolytes and solutes, liver and kidney function, urinalysis, and complete blood count is undertaken along with frequent checking of salicylate and blood sugar levels.
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Although, liquid water will only move in response to such differences in osmotic potential if a semipermeable membrane exists between the zones of high and low osmotic potential. A semipermeable membrane is necessary because it allows water through its membrane while preventing solutes from moving through its membrane. If no membrane is present, movement of the solute, rather than of the water, largely equalizes concentrations. Since regions of soil are usually not divided by a semipermeable membrane, the osmotic potential typically has a negligible influence on the mass movement of water in soils.
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Without the stiffness of the plant cells the plant would fall under its own weight. Turgor pressure allows plants to stay firm and erect, and plants without turgor pressure (known as flaccid) wilt. A cell will begin to decline in turgor pressure only when there is no air spaces surrounding it and eventually leads to a greater osmotic pressure than that of the cell. Vacuoles play a role in turgor pressure when water leaves the cell due to hyperosmotic solutions containing solutes such as mannitol, sorbitol, and sucrose.
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This is because as the solution surrounding the cell is hypertonic, exosmosis takes place and the space between the cell wall and cytoplasm is filled with solutes, as most of the water drains away and hence the concentration inside the cell becomes more hypertonic. There are some mechanisms in plants to prevent excess water loss in the same way as excess water gain. Plasmolysis can be reversed if the cell is placed in a hypotonic solution. Stomata help keep water in the plant so it does not dry out.
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A rete mirabile (Latin for "wonderful net"; plural retia mirabilia) is a complex of arteries and veins lying very close to each other, found in some vertebrates, mainly warm-blooded ones. The rete mirabile utilizes countercurrent blood flow within the net (blood flowing in opposite directions) to act as a countercurrent exchanger. It exchanges heat, ions, or gases between vessel walls so that the two bloodstreams within the rete maintain a gradient with respect to temperature, or concentration of gases or solutes. This term was coined by Galen.
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Cellular osmolytes are polar small molecules that are synthesized or taken up by cells to maintain the integrity of cellular components during periods of osmotic or other forms of stress. Osmolytes are diverse in chemical structure, and include polyols, sugars, methylamines, and free amino acids and their derivatives. Examples of these include glycerol, trehalose, trimethylamine n-oxide (TMAO), and glycine. Despite being most active at relatively high concentrations, osmolytes don’t display any effects on normal cellular processes – for this reason, they are also commonly referred to as “compatible solutes”.
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One of the kidneys’ important functions is to reabsorb water after glomerular filtration. The complex process of reabsorption is usually one of the first renal functions to be affected by disease. The specific gravity of urine is a measure of its density compared to H2O and depends on the quantity and density of solutes (molecules with more mass per volume increase measure of specific gravity). The measurement of specific gravity should not be confused with the measurement of osmotic concentration, which is more related to the number of particles than with their mass.
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Additionally, as the cells shrink, the solutes inside the cells are concentrated in the remaining water, increasing the intracellular ionic strength and interfering with the organization of the proteins and other organized intercellular structures. Eventually, the solute concentration inside the cells reaches the eutectic and freezes. The final state of frozen tissues is pure ice in the former extracellular spaces, and inside the cell membranes a mixture of concentrated cellular components in ice and bound water. In general, this process is not reversible to the point of restoring the tissues to life.
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Reabsorption of molecules and ions back into the blood from the proximal tube is done via epithelial cells. The epithelial cell create a low Na+ concentration within the cell by actively pumping out Na+ into the blood via a Na+/K+ ATPase pump on the basolateral membrane. The osmotic gradient allows for the cotransport of Na+ with molecules such as Cl-, glucose, and vitamins into the epithelial cell from the apical side (side facing the proximal tubule). Water freely crosses the apical side into the epithelial cell following the solutes entering actively.
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These are liquid solutions of one or more organic scintillators in an organic solvent. The typical solutes are fluors such as p-terphenyl (), PBD (), butyl PBD (), PPO (), and wavelength shifter such as POPOP (). The most widely used solvents are toluene, xylene, benzene, phenylcyclohexane, triethylbenzene, and decalin. Liquid scintillators are easily loaded with other additives such as wavelength shifters to match the spectral sensitivity range of a particular PMT, or 10B to increase the neutron detection efficiency of the scintillation counter itself (since 10B has a high interaction cross section with thermal neutrons).
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The CSDMS architecture employs frameworks and services that convert stand-alone models into flexible "plug- and-play" components to be assembled into larger applications. CSDMS focuses on the movement of fluids and the sediment and solutes they transport through landscapes, seascapes and sedimentary basins. Began in 2007 under the leadership of James Syvitski, formerly the director of the Institute of Arctic and Alpine Research (INSTAAR), Boulder, CO, CSDMS operates under continuing funding from the National Science Foundation (NSF) to coordinate this national effort related to surface dynamic modeling.
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In conjunction with the gene research is another theory of how the disease manifests. This is called the free particle theory. This theory says that the increasing concentration of lithogenic solutes along the segments of the nephron leads to the formation, growth, and collection of crystals that might get trapped in the tubular lumen and begin the process of stone formation. Some of the backing behind this theory is the speed of growth of the crystals, the diameter of the segments of the nephron, and the transit time in the nephron.
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When glutamine eventually reaches the leaves, it is broken down and used to synthesise protein and non-amide amino acids such as aspartate, threonine, serine, glutamate, glycine, alanine and cystine. Together with sucrose and other solutes, these are then circulated in the phloem. The phloem sap of B. prionotes is unusual in having an extremely low ratio of potassium to sodium cations, and very low concentrations of phosphate and amino acids compared to chloride and sulfate anions. The low levels of potassium and phosphate reflect the extremely low availability of these minerals in the soil.
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Physical impacts or vibrations, though crucial for animals, have little effect on microbes such as E. coli. In comparison, osmotic force greatly affects individual cells or microbes within their aquatic environment. When bacteria is under osmotic downshock, which is during the transition from media of high osmolarity to low, water inflow gives rise to a substantial increase in the turgor pressure, which is capable of bursting the cell envelope. Mechanosensitive channels are major pathways for the release of cytoplasmic solutes to achieve a rapid reduction of the turgor pressure, therefore avoiding lysis.
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Nanotechnology offers the potential of novel nanomaterials for the treatment of surface water, groundwater, wastewater, and other environmental materials contaminated by toxic metal ions, organic and inorganic solutes, and microorganisms. Due to their unique activity toward recalcitrant contaminants, many nanomaterials are under active research and development for use in the treatment of water and contaminated sites. The present market of nanotech-based technologies applied in water treatment consists of reverse osmosis(RO), nanofiltration, ultrafiltration membranes. Indeed, among emerging products one can name nanofiber filters, carbon nanotubes and various nanoparticles.
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Semi-moist pet food such as chewy dog treats and soft cat treats are shelf-stable, soft and do not have a high moisture content. Ingredients added to intermediate moisture pet food to achieve lower water activity are soy flakes and wheat flour in addition to solutes such as glycerol, salt, and sugar. Processing techniques such as extrusion are employed to attain the final intermediate moisture pet food. Intermediate moisture pet food are convenient products because they leave less odor and are less messy than canned wet pet food.
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When high purity is required, such as in semiconductor industry, the impure end of the boule is cut off, and the refining is repeated. In zone refining, solutes are segregated at one end of the ingot in order to purify the remainder, or to concentrate the impurities. In zone leveling, the objective is to distribute solute evenly throughout the purified material, which may be sought in the form of a single crystal. For example, in the preparation of a transistor or diode semiconductor, an ingot of germanium is first purified by zone refining.
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Alloying a metal is done by combining it with one or more other elements. The most common and oldest alloying process is performed by heating the base metal beyond its melting point and then dissolving the solutes into the molten liquid, which may be possible even if the melting point of the solute is far greater than that of the base. For example, in its liquid state, titanium is a very strong solvent capable of dissolving most metals and elements. In addition, it readily absorbs gases like oxygen and burns in the presence of nitrogen.
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These metals were typically lead, antimony, bismuth or copper. These solutes were sometimes added individually in varying amounts, or added together, making a wide variety of objects, ranging from practical items such as dishes, surgical tools, candlesticks or funnels, to decorative items like ear rings and hair clips. The earliest examples of pewter come from ancient Egypt, around 1450 BC. The use of pewter was widespread across Europe, from France to Norway and Britain (where most of the ancient tin was mined) to the Near East.Hull, Charles (1992) Pewter.
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Example of a Langmuir isotherm, for a population of binding sites having uniform affinity. In this case the vertical axis represents the amount bound per unit of stationary phase, the horizontal axis the concentration in the mobile phase. In this case, the dissociation constant is 0.5 and the capacity 10; units are arbitrary. The basic principle of displacement chromatography is: there are only a finite number of binding sites for solutes on the matrix (the stationary phase), and if a site is occupied by one molecule, it is unavailable to others.
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In elution mode, solutes are applied to the column as narrow bands and, at low concentration, move down the column as approximately Gaussian peaks. These peaks continue to broaden as they travel, in proportion to the square root of the distance traveled. For two substances to be resolved, they must migrate down the column at sufficiently different rates to overcome the effects of band spreading. Operating at high concentration, where the isotherm is curved, is disadvantageous in elution chromatography because the rate of travel then depends on concentration, causing the peaks to spread and distort.
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The apoplastic and symplastic pathways The symplast of a plant is the inner side of the plasma membrane in which water and low-molecular-weight solutes can freely diffuse. Symplast cells have more than one nucleus. (Water and low molecular weight pass through pore in the adjacent cell walls)And cytoplasmic connection through pore are known as plasmodesmata.. The plasmodesmata allow the direct flow of small molecules such as sugars, amino acids, and ions between cells. Larger molecules, including transcription factors and plant viruses, can also be transported through with the help of actin structures.
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There are different pieces of evidences that support the hypothesis. Firstly, there is an exudation of solution from the phloem when the stem is cut or punctured by the Stylet of an aphid, a classical experiment demonstrating the translocation function of phloem, indicating that the phloem sap is under pressure. Secondly, concentration gradients of organic solutes are proved to be present between the sink and the source. Thirdly, when viruses or growth chemicals are applied to a well-illuminated (actively photosynthesising) leaf, they are translocated downwards to the roots.
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Dry oxygen does not react with crystalline LiH unless heated strongly, when an almost explosive combustion occurs. LiH is highly reactive toward water and other protic reagents: :LiH + H2O → Li+ \+ H2 \+ OH− LiH is less reactive with water than Li and thus is a much less powerful reducing agent for water, alcohols, and other media containing reducible solutes. This is true for all the binary saline hydrides. LiH pellets slowly expand in moist air, forming LiOH; however, the expansion rate is below 10% within 24 hours in a pressure of 2 Torr of water vapor.
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Osmosis diffusion ultrafiltration and dialysis The two main types of dialysis, hemodialysis and peritoneal dialysis, remove wastes and excess water from the blood in different ways. Hemodialysis removes wastes and water by circulating blood outside the body through an external filter, called a dialyzer, that contains a semipermeable membrane. The blood flows in one direction and the dialysate flows in the opposite. The counter-current flow of the blood and dialysate maximizes the concentration gradient of solutes between the blood and dialysate, which helps to remove more urea and creatinine from the blood.
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The change in chemical potential of a solvent when a solute is added explains why boiling point elevation takes place. The boiling point elevation is a colligative property, which means that it is dependent on the presence of dissolved particles and their number, but not their identity. It is an effect of the dilution of the solvent in the presence of a solute. It is a phenomenon that happens for all solutes in all solutions, even in ideal solutions, and does not depend on any specific solute–solvent interactions.
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The main application of gel-filtration chromatography is the fractionation of proteins and other water-soluble polymers, while gel permeation chromatography is used to analyze the molecular weight distribution of organic-soluble polymers. Either technique should not be confused with gel electrophoresis, where an electric field is used to "pull" or "push" molecules through the gel depending on their electrical charges. The amount of time a solute remains within a pore is dependent on the size of the pore. Larger solutes will have access to a smaller volume and vice versa.
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The impact that formed the Argyre basin probably struck an ice cap or a thick permafrost layer. Energy from the impact melted the ice and formed a giant lake that eventually sent water to the North. The lakes's volume was equal to that of Earth's Mediterranean Sea. The deepest part of the lake may have taken more than a hundred thousand years to freeze, but with the help of heat from the impact, geothermal heating, and dissolved solutes it may have had liquid water for many millions of years.
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Another extremely important factor in dealing with drought stress and regulating the uptake and export of water is aquaporins (AQPs). AQPs are integral membrane proteins that make up channels. These channels' main job is the transport of water and other necessary solutes. AQPs are both transcriptionally and post transcriptionally regulated by many different factors such as ABA, GA3, pH and Ca2+ and the specific levels of AQPs in certain parts of the plant, such as roots or leaves, helps to draw as much water into the plant as possible.
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S1PR1 is one of the main receptors responsible for vascular growth and development, at least during embryogenesis. In vascular endothelial cells the binding of S1P to S1PR1 induces migration, proliferation, cell survival and morphogenesis into capillary-like structures. Moreover, the binding of S1P to S1PR1 is implicated in the formation of cell-cell adherens junctions, therefore inhibiting paracellular permeability of solutes and macromolecules. It was also shown in vivo that S1P synergizes with angiogenic factors such as FGF-2 and VEGF in inducing angiogenesis and vascular maturation through S1PR1.
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Auxins activate proton pumps, decreasing the pH in the cells on the dark side of the plant. This acidification of the cell wall region activates enzymes known as expansins which disrupt hydrogen bonds in the cell wall structure, making the cell walls less rigid. In addition, increased proton pump activity leads to more solutes entering the plant cells on the dark side of the plant, which increases the osmotic gradient between the symplast and apoplast of these plant cells. Water then enters the cells along its osmotic gradient, leading to an increase in turgor pressure.
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Na+/K+ATPase Transmembrane ATPases import many of the metabolites necessary for cell metabolism and export toxins, wastes, and solutes that can hinder cellular processes. An important example is the sodium-potassium exchanger (or Na+/K+ATPase) that maintains the cell membrane potential. And another example is the hydrogen potassium ATPase (H+/K+ATPase or gastric proton pump) that acidifies the contents of the stomach. ATPase is genetically conserved in animals; therefore, cardenolides which are toxic steroids produced by plants that act on ATPases, make general and effective animal toxins that act dose dependently.
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Liquid acetic acid is a hydrophilic (polar) protic solvent, similar to ethanol and water. With a moderate relative static permittivity (dielectric constant) of 6.2, it dissolves not only polar compounds such as inorganic salts and sugars, but also non-polar compounds such as oils as well as polar solutes. It is miscible with polar and non-polar solvents such as water, chloroform, and hexane. With higher alkanes (starting with octane), acetic acid is not miscible at all compositions, and solubility of acetic acid in alkanes declines with longer n-alkanes.
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The osmolar gap is the difference between the measured osmolality and the calculated osmolarity. The difference in units is attributed to the difference in the way that blood solutes are measured in the laboratory versus the way they are calculated. The laboratory value measures the freezing point depression, properly called osmolality while the calculated value is given in units of osmolarity. Even though these values are presented in different units, when there is a small amount of solute compared to total volume of solution, the absolute values of osmolality vs.
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The second Kedem–Katchalsky equation explains the trans endothelial transport of solutes, J_s . Glomerular capillaries have a continuous glycocalyx layer in health and the total transendothelial filtration rate of solvent ( J_v ) to the renal tubules is normally around 125 ml/ min (about 180 litres/ day). Glomerular capillary J_v is more familiarly known as the glomerular filtration rate (GFR). In the rest of the body's capillaries, J_v is typically 5 ml/ min (around 8 litres/ day), and the fluid is returned to the circulation via afferent and efferent lymphatics.
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Claudin 3, also known as CLDN3, is a protein which in humans is encoded by the CLDN3 gene. It is a member of the claudin protein family. Tight junctions represent one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the paracellular space. These junctions are composed of sets of continuous networking strands in the outwardly facing cytoplasmic leaflet, with complementary grooves in the inwardly facing extracytoplasmic leaflet.
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The theory of eddy diffusion was developed by Sir Geoffrey Ingram Taylor. Because the microscopic processes responsible for atmospheric mixing are too complex to model in detail, atmospheric modelers generally treat atmospheric mixing as a macroscopic "eddy" diffusion process. In this approach, the diffusion rate at each pressure level is parameterized by a quantity known as the eddy diffusion coefficient, K (also sometimes called eddy diffusivity, with units of m2 s−1).The eddy diffusion coefficient is used in the diffusion equation, to describe the dispersion or mixing of solutes in fluid or atmospheric systems.
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Tight junctions represent one mode of cell-to-cell adhesion in endothelial cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the paracellular space. The protein encoded by this immunoglobulin superfamily gene member is localized in the tight junctions between high endothelial cells. It acts as an adhesive ligand for interacting with a variety of immune cell types and may play a role in lymphocyte homing to secondary lymphoid organs. It is purported to promote lymphocyte transendothelial migration.
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For instance the loss of draw solution may affect the feed solution perhaps due to environmental issues or contamination of the feed stream, such as in osmotic membrane bioreactors. An additional distinction between the reverse osmosis (RO) and forward osmosis (FO) processes is that the permeate water resulting from an RO process is in most cases fresh water ready for use. In the FO process, this is not the case. The membrane separation of the FO process in effect results in a "trade" between the solutes of the feed solution and the draw solution.
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An area of current research in FO involves direct removal of draw solutes, in this case by means of a magnetic field. Small (nanoscale) magnetic particles are suspended in solution creating osmotic pressures sufficient for the separation of water from a dilute feed. Once the draw solution containing these particles has been diluted by the FO water flux, they may be separated from that solution by use of a magnet (either against the side of a hydration bag, or around a pipe in-line in a steady state process).
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375px Osmosis is the process in which water flows from an area with a low solute concentration, to an adjacent area with a higher solute concentration until equilibrium between the two areas is reached. All cells are surrounded by a lipid bi-layer cell membrane which permits the flow of water in and out of the cell while also limiting the flow of solutes. In hypertonic solutions, water flows out of the cell which decreases the cell's volume. When in a hypotonic solution, water flows into the membrane and increases the cell's volume.
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When measuring turgor pressure in plants, many things have to be taken into account. It is generally stated that fully turgid cells have a turgor pressure value which is equal to that of the cell and that flaccid cells have a value at or near zero. Other cellular mechanisms taken into consideration include the protoplast, solutes within the protoplast (solute potential), transpiration rates of the plant and the tension of cell walls. Measurement is limited depending on the method used, some of which are explored and explained below.
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SEDEX deposits form in sedimentary basins under a regional tectonic extensional environment, under the ocean where cold seawater (blue arrows) is mixed with basin water and through sinsedimentary faults flow towards the bottom of the basin, which are heated by the geothermal gradient, and later ascends by convective currents (red arrows). Model for the origin of the Red Sea sulfide deposits. Cold seawater (blue arrows) enters the seafloor via deep-seated fractures. As it descends, it heats up and leaches silicon, metals and other solutes from the seafloor basalts.
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Yield and related morphological characters responded better at certain of the field capacity compared when with other treatments. A study was conducted in the experimental field of Sher-e-Bangla Agricultural University, in Dhaka, Bangladesh to study the effect of water stress on fruit quality and osmotic adjustment in different types. The plants had a tendency to adjust against drop in potential in soil by producing organic solutes such as glucose, fructose, sucrose and proline. The quality of fruits was improved as a result of the synthesis of ascorbic acid, citric acid and malic acid.
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The centrifugation process itself has four variables that can be controlled to selectively remove desired components. The first is spin speed and bowl diameter, the second is "sit time" in centrifuge, the third is solutes added, and the fourth is not as easily controllable: plasma volume and cellular content of the donor. The end product in most cases is the classic sedimented blood sample with the RBC's at the bottom, the buffy coat of platelets and WBC's (lymphocytes/granulocytes, PMN's, basophils, eosinophils/monocytes) in the middle and the plasma on top.
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Adults generally have a specific gravity in the range of 1.010 to 1.030. Increases in specific gravity (hypersthenuria, i.e. increased concentration of solutes in the urine) may be associated with dehydration, diarrhea, emesis, excessive sweating, urinary tract/bladder infection, glucosuria, renal artery stenosis, hepatorenal syndrome, decreased blood flow to the kidney (especially as a result of heart failure), and an excess of antidiuretic hormone caused by the syndrome of inappropriate antidiuretic hormone secretion.Explanation of Hepatorenal Syndrome on MedlinePlus A specific gravity greater than 1.035 is consistent with frank dehydration.
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Tolerance of such conditions is reached through the use of stress proteins and compatible cytoplasm osmotic solutes. To exist in such conditions, halophytes tend to be subject to the uptake of high levels of salt into their cells, and this is often required to maintain an osmotic potential lower than that of the soil to ensure water uptake. High salt concentrations within the cell can be damaging to sensitive organelles such as the chloroplast, so sequestration of salt is seen. Under this action, salt is stored within the vacuole to protect such delicate areas.
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When used as a rinse after washing cars, windows, and similar applications, purified water dries without leaving spots caused by dissolved solutes. Deionized water is used in water-fog fire-extinguishing systems used in sensitive environments, such as where high-voltage electrical and sensitive electronic equipment is used. The 'sprinkler' nozzles use much finer spray jets than other systems, and operate at up 35 MPa (350 bar; 5,000 psi) of pressure. The extremely fine mist produced takes the heat out of a fire rapidly, and the fine droplets of water are nonconducting (when deionized) and are less likely to damage sensitive equipment.
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Vascular tissues are used to move hormones from one part of the plant to another; these include sieve tubes or phloem that move sugars from the leaves to the roots and flowers, and xylem that moves water and mineral solutes from the roots to the foliage. Not all plant cells respond to hormones, but those cells that do are programmed to respond at specific points in their growth cycle. The greatest effects occur at specific stages during the cell's life, with diminished effects occurring before or after this period. Plants need hormones at very specific times during plant growth and at specific locations.
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The most well-studied and well- established function of viroporins is the permeabilization of the cell membrane to ions and small solutes. Before viroporins themselves were understood as a class, it was well known that many viruses induce membrane permeabilization in infected cells; viroporins are at least partially responsible for this effect, particularly when it occurs late in the viral replication cycle. Viroporins expressed transgenically, in the absence of their virus of origin, induce the same effect, a feature that has facilitated viroporin discovery. In most cases, pores formed by viroporins are nonselective or only weakly selective for particular ions or small molecules.
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Photographs showing xylem elements in the shoot of a fig tree (Ficus alba): crushed in hydrochloric acid, between slides and cover slips. Water and nutrients in the form of inorganic solutes are drawn up from the soil by the roots and transported throughout the plant by the xylem. Organic compounds such as sucrose produced by photosynthesis in leaves are distributed by the phloem sieve tube elements. The xylem consists of vessels in flowering plants and tracheids in other vascular plants, which are dead hard-walled hollow cells arranged to form files of tubes that function in water transport.
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The human body and even its individual body fluids may be conceptually divided into various fluid compartments, which, although not literally anatomic compartments, do represent a real division in terms of how portions of the body's water, solutes, and suspended elements are segregated. The two main fluid compartments are the intracellular and extracellular compartments. The intracellular compartment is the space within the organism's cells; it is separated from the extracellular compartment by cell membranes. About two- thirds of the total body water of humans is held in the cells, mostly in the cytosol, and the remainder is found in the extracellular compartment.
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Photographer: Armin Kübelbeck, CC-BY-SA, Wikimedia Commons Solvent polarity is the most important factor in determining how well it solvates a particular solute. Polar solvents have molecular dipoles, meaning that part of the solvent molecule has more electron density than another part of the molecule. The part with more electron density will experience a partial negative charge while the part with less electron density will experience a partial positive charge. Polar solvent molecules can solvate polar solutes and ions because they can orient the appropriate partially charged portion of the molecule towards the solute through electrostatic attraction.
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The action of the Na+/K+/2Cl− transporter therefore creates a hypoosmolar solution in the tubular fluid and a hyperosmolar fluid in the interstitium, since water cannot follow the solutes to produce osmotic equilibrium. Equilibration: Since the descending limb of the loop of henle consists of very leaky epithelium, the fluid inside the descending limb becomes hyperosmolar. Shift: The movement of fluid through the tubules causes the hyperosmotic fluid to move further down the loop. Repeating many cycles causes fluid to be near isosmolar at the top of Henle's loop and very concentrated at the bottom of the loop.
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Analytical laboratories use solid phase extraction to concentrate and purify samples for analysis. Solid phase extraction can be used to isolate analytes of interest from a wide variety of matrices, including urine, blood, water, beverages, soil, and animal tissue. SPE uses the affinity of solutes dissolved or suspended in a liquid (known as the mobile phase) for a solid through which the sample is passed (known as the stationary phase) to separate a mixture into desired and undesired components. The result is that either the desired analytes of interest or undesired impurities in the sample are retained on the stationary phase.
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The requirement for high pressures increases the cost compared to conventional liquid extraction, so SFE will only be used where there are significant advantages. Carbon dioxide itself is non-polar, and has somewhat limited dissolving power, so cannot always be used as a solvent on its own, particularly for polar solutes. The use of modifiers increases the range of materials which can be extracted. Food grade modifiers such as ethanol can often be used, and can also help in the collection of the extracted material, but reduces some of the benefits of using a solvent which is gaseous at room temperature.
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The term is typically applied in contexts wherein a chemical reaction is to take place, such as one involving the transfer of an electron at a battery electrode. In a battery, an electrochemical potential arising from the movement of ions balances the reaction energy of the electrodes. The maximum voltage that a battery reaction can produce is sometimes called the standard electrochemical potential of that reaction (see also Electrode potential and Table of standard electrode potentials). In instances pertaining specifically to the movement of electrically charged solutes, the potential is often expressed in units of volts.
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Vapor phase osmometry (VPO), also known as vapor-pressure osmometry, is an experimental technique for the determination of a polymer's number average molecular weight, Mn. It works by taking advantage of the decrease in vapor pressure that occurs when solutes are added to pure solvent. This technique can be used for polymers with a molecular weight of up to 20,000 though accuracy is best for those below 10,000. Although membrane osmometry is also based on the measurement of colligative properties, it has a lower bound of 25,000 for sample molecular weight that can be measured owing to problems with membrane permeation.
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For the solvent isotope effects to be measurable, a finite fraction of the solvent must have a different isotopic composition than the rest. Therefore, large amounts of the less common isotopic species must be available, limiting observable solvent isotope effects to isotopic substitutions involving hydrogen. Detectable kinetic isotope effects occur only when solutes exchange hydrogen with the solvent or when there is a specific solute-solvent interaction near the reaction site. Both such phenomena are common for protic solvents, in which the hydrogen is exchangeable, and they may form dipole-dipole interactions or hydrogen bonds with polar molecules.
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The contraction of the contractile vacuole and the expulsion of water out of the cell is called systole. Water always flows first from outside the cell into the cytoplasm, and is only then moved from the cytoplasm into the contractile vacuole for expulsion. Species that possess a contractile vacuole typically always use the organelle, even at very hypertonic (high concentration of solutes) environments, since the cell tends to adjust its cytoplasm to become even more hyperosmotic than the environment. The amount of water expelled from the cell and the rate of contraction are related to the osmolarity of the environment.
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Osmotic shock or osmotic stress is physiologic dysfunction caused by a sudden change in the solute concentration around a cell, which causes a rapid change in the movement of water across its cell membrane. Under conditions of high concentrations of either salts, substrates or any solute in the supernatant, water is drawn out of the cells through osmosis. This also inhibits the transport of substrates and cofactors into the cell thus “shocking” the cell. Alternatively, at low concentrations of solutes, water enters the cell in large amounts, causing it to swell and either burst or undergo apoptosis.
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The Marine Unsaturated Model (MARUN model) is a two-dimensional (vertical slice) finite element model capable of simulating the migration of water and solutes in saturated-unsaturated porous media while accounting for the impact of solute concentration on water density and viscosity, as saltwater is heaving and more viscous than freshwater. The detailed formulation of the MARUN model is found in (Boufadel et al. 1998)Boufadel, M. C., M. T. Suidan, C. H. Rauch, A. D. Venosa and P. Biswas (1998). "2-D variably-saturated flow: Physical scaling and Bayesian estimation." Journal of Hydrologic Engineering 3(10): 223-231.
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Frank and Hess studies the Sporendonema epizoum (synonym of W. sebi) that grow on dried salted fish and suggested it to be halophilic in 1941. Wallemia sebi is now recognized as xerophilic fungi because of independence of solute used to lower the water activity. Pitt and Hocking report that W.sebi grows more rapidly in NaCl that other solutes at neutral pH, but have no requirement for NaCl as a solute in 1977. This species is abundant in house dust and suspected to be a causative agent for atopic diseases in the study conducted by Sakamono et al.
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Counter current multiplier diagram The loop of Henle is supplied by blood in a series of straight capillaries descending from the cortical efferent arterioles. These capillaries (called the vasa recta; recta is from the Latin for "straight") also have a countercurrent multiplier mechanism that prevents washout of solutes from the medulla, thereby maintaining the medullary concentration. As water is osmotically driven from the descending limb into the interstitium, it readily enters the capillaries. The low bloodflow through the vasa recta allows time for osmotic equilibration, and can be altered by changing the resistance of the vessels' efferent arterioles.
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Microdialysis takes advantage of a semi-permeable membrane, across which small molecules and ions can pass, while proteins and large polymers cannot cross. By establishing a gradient of solute concentration across the membrane and allowing the system to progress toward equilibrium, the system can slowly move toward supersaturation, at which point protein crystals may form. Microdialysis can produce crystals by salting out, employing high concentrations of salt or other small membrane-permeable compounds that decrease the solubility of the protein. Very occasionally, some proteins can be crystallized by dialysis salting in, by dialyzing against pure water, removing solutes, driving self-association and crystallization.
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In the 1st phase, organic solutes (such as phosphates, amino acids, glucose and anions), sodium ions, and hydronium ions are reabsorbed from the filtrate fluid into the interstitial fluid. This is an important step because this creates the concentration gradient in which chloride concentration in the lumen will increase in comparison to the chloride concentration in the interstitial fluid. In phase 2, chloride will diffuse along the concentration gradient, which means chloride ions will travel from areas of high concentration to areas of low concentration. One suggested mechanism leading to hyperchloremia, there is a decrease in chloride transporter proteins along the nephron.
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Bi-directional movements of solutes in translocation process as well as the fact that translocation is heavily affected by changes in environmental conditions like temperature and metabolic inhibitors are two defects of the hypothesis. An objection leveled against the pressure flow mechanism is that it does not explain the phenomenon of bidirectional movement i.e. movement of different substances in opponent directions at the same time. The phenomenon of bidirectional movement can be demonstrated by applying two different substances at the same time to the phloem of a stem at two different points, and following their longitudinal movement along the stem.
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Welton works in the field of sustainable chemistry, and has spent most of his career studying the properties of ionic liquids, their interactions with solutes, and the resulting effects on chemical reactions. He was the world's first Professor of Sustainable Chemistry. His research group also works on applications for these phenomena in developing environmentally safe organic synthesis methods and in the production of biofuels. Ionic liquids became commercially available in 1999, meaning that you 'no longer had to be an expert in the synthesis of ionic liquids to be able to use these in your research'.
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Bioturbators are deemed ecosystem engineers because they alter resource availability to other species through the physical changes they make to their environments. This type of ecosystem change affects the evolution of cohabitating species and the environment, which is evident in trace fossils left in marine and terrestrial sediments. Other bioturbation effects include altering the texture of sediments (diagenesis), bioirrigation, and displacement of microorganisms and non-living particles. Bioturbation is sometimes confused with the process of bioirrigation, however these processes differ in what they are mixing; bioirrigation refers to the mixing of water and solutes in sediments and is an effect of bioturbation.
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In medicine, dialysis (from Greek διάλυσις, dialysis, "dissolution"; from διά, dia, "through", and λύσις, lysis, "loosening or splitting") is the process of removing excess water, solutes, and toxins from the blood in people whose kidneys can no longer perform these functions naturally. This is referred to as renal replacement therapy. The first successful dialysis was performed in 1943. Dialysis may need to be initiated when there is a sudden rapid loss of kidney function, known as acute kidney injury (previously called acute renal failure), or when a gradual decline in kidney function -chronic kidney disease reaches stage 5.
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St. Louis, MO; Mosby: 2006 Blood flows by one side of a semi-permeable membrane, and a dialysate, or special dialysis fluid, flows by the opposite side. A semipermeable membrane is a thin layer of material that contains holes of various sizes, or pores. Smaller solutes and fluid pass through the membrane, but the membrane blocks the passage of larger substances (for example, red blood cells and large proteins). This replicates the filtering process that takes place in the kidneys when the blood enters the kidneys and the larger substances are separated from the smaller ones in the glomerulus.
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The boiling point elevation happens both when the solute is an electrolyte, such as various salts, and a nonelectrolyte. In thermodynamic terms, the origin of the boiling point elevation is entropic and can be explained in terms of the vapor pressure or chemical potential of the solvent. In both cases, the explanation depends on the fact that many solutes are only present in the liquid phase and do not enter into the gas phase (except at extremely high temperatures). Put in vapor pressure terms, a liquid boils at the temperature when its vapor pressure equals the surrounding pressure.
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For a solute that adsorbs at surface, diffusioosmotic flow is away from regions of high solute concentration, while for solutes that are repelled by the surface, flow is away from regions of low solute concentration.This schematic illustrates diffusioosmotic flow above a surface in contact with a solution that has a concentration gradient of a solute (red). The flow as a function of height above the surface is shown as black arrows of length proportional to the flow velocity at that height. The flow is left-to-right as this solute is repelled by the surface, and its concentration increases from left-to-right.
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Magnetic micro particles are proven research instruments for the separation of cells and proteins from complex media. The technology is available under the name Magnetic-activated cell sorting or Dynabeads among others. More recently it was shown in animal models that magnetic nanoparticles can be used for the removal of various noxious compounds including toxins, pathogens, and proteins from whole blood in an extracorporeal circuit similar to dialysis. In contrast to dialysis, which works on the principle of the size related diffusion of solutes and ultrafiltration of fluid across a semi-permeable membrane, the purification with nanoparticles allows specific targeting of substances.
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Tight junctions represent one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the paracellular space. These junctions are composed of sets of continuous networking strands in the outwardly facing cytoplasmic leaflet, with complementary grooves in the inwardly facing extracytoplasmic leaflet. The protein encoded by this gene, a member of the claudin family, is an integral membrane protein and a component of tight junction strands. Loss of function mutations result in neonatal ichthyosis-sclerosing cholangitis syndrome.
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Both HYDRUS models may be used to simulate movement of water, heat, and multiple solutes in variably saturated media. Both programs use linear finite elements to numerically solve the Richards equation for saturated-unsaturated water flow and Fickian-based advection dispersion equations for both heat and solute transport. The flow equation also includes a sink term to account for water uptake by plant roots as a function of both water and salinity stress. The unsaturated soil hydraulic properties can be described using van Genuchten, Brooks and Corey, modified van Genuchten, Kosugi, and Durner type analytical functions.
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Tight junctions represent one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the paracellular space. The protein encoded by this immunoglobulin superfamily gene member is an important regulator of tight junction assembly in epithelia. In addition, the encoded protein can act as (1) a receptor for reovirus, (2) a ligand for the integrin LFA1, involved in leukocyte transmigration, and (3) a platelet receptor. Multiple transcript variants encoding two different isoforms have been found for this gene.
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Modeling eddy development, as it relates to turbulence and fate transport phenomena, is vital in grasping an understanding of environmental systems. By understanding the transport of both particulate and dissolved solids in environmental flows, scientists and engineers will be able to efficiently formulate remediation strategies for pollution events. Eddy formations play a vital role in the fate and transport of solutes and particles in environmental flows such as in rivers, lakes, oceans, and the atmosphere. Upwelling in stratified coastal estuaries warrant the formation of dynamic eddies which distribute nutrients out from beneath the boundary layer to form plumes.
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Being involved in water uptake and regulation of solutes into and out of the membrane, the exodermal cells must adapt to their external environment to ensure that the plant can survive. Because there are so many individual species of plant, each with different environmental conditions and with different nutrient requirements, it is the variability of this membrane that provides the option to ensure appropriate nutrient levels are reached. Exodermal cells can modify their Casparian strips to fit changing stimuli. Exodermal barriers can change their permeability as necessary to ensure that adequate nutrients are reaching the plant.
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Appropriate ADH secretion is regulated by osmoreceptors on the hypothalamic cells that synthesize and store ADH: plasma hypertonicity activates these receptors, ADH is released into the blood stream, the kidney increases solute-free water return to the circulation, and the hypertonicity is alleviated. Inappropriate (increased) ADH secretion causes an unrelenting increase in solute-free water ("free water") absorption by the kidneys, with two consequences. First, in the extracellular fluid (ECF) space, there is a dilution of blood solutes, causing hypoosmolality, including a low sodium concentration - hyponatremia. Then virtually simultaneously, in the intracellular space, cells swell, i.e.
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The normal function of ADH on the kidneys is to control the amount of water reabsorbed by kidney nephrons. ADH acts in the distal portion of the renal tubule (Distal Convoluted Tubule) as well as on the collecting duct and causes the retention of water, but not solute. Hence, ADH activity effectively dilutes the blood (decreasing the concentrations of solutes such as sodium), causing hyponatremia; this is compounded by the fact that the body responds to water retention by decreasing aldosterone, thus allowing even more sodium wasting. For this reason, a high urinary sodium excretion will be seen.
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The endodermis prevents water, and any solutes dissolved in the water, from passing through this layer via the apoplast pathway. Water can only pass through the endodermis by crossing the membrane of endodermal cells twice (once to enter and a second time to exit). Water moving into or out of the xylem, which is part of the apoplast, can thereby be regulated since it must enter the symplast in the endodermis. This allows the plant to control to some degree the movement of water and to selectively uptake or prevent the passage of ions or other molecules.
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For example, it is impossible to separate the constituents of azeotropic liquids or solutes which form isomorphic crystals by distillation or recrystallization but such separations can be achieved using membrane technology. Depending on the type of membrane, the selective separation of certain individual substances or substance mixtures is possible. Important technical applications include the production of drinking water by reverse osmosis (worldwide approximately 7 million cubic metres annually), filtrations in the food industry, the recovery of organic vapours such as petro-chemical vapour recovery and the electrolysis for chlorine production. In waste water treatment, membrane technology is becoming increasingly important.
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They allow for the filtration of fluid, blood plasma solutes and protein, at the same time preventing the filtration of red blood cells, white blood cells, and platelets. The glomerulus has a glomerular basement membrane consisting mainly of laminins, type IV collagen, agrin and nidogen, which are synthesized and secreted by both endothelial cells and podocytes: thus the glomerular basement membrane is sandwiched between the glomerular capillaries and the podocytes. The glomerular baement membrane is 250–400 nm in thickness, which is thicker than basement membranes of other tissue. It is a barrier to blood proteins such as albumin and globulin.
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Gas-vaculate cyanobacterium are the ones generally responsible for water-blooms. They have the ability to float due to the accumulation of gases within their vacuole, and the role of turgor pressure and its effect on the capacity of these vacuoles has been observed in varying scientific papers. It is noted that the higher the turgor pressure, the lower the capacity of the gas-vacuoles in different cyanobacterium. Experiments used to correlate osmosis and turgor pressure in prokaryotes have been used to show how diffusion of solutes into the cell have a play on turgor pressure within the cell.
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Molecular weight cut-off or MWCO refers to the lowest molecular weight solute (in daltons) in which 90% of the solute is retained by the membrane, or the molecular weight of the molecule (e.g. globular protein) that is 90% retained by the membrane. This definition is not however standardized, and MWCOs can also be defined as the molecular weight at which 80% of the analytes (or solutes) are prohibited from membrane diffusion. Commercially available microdialysis probes typically have molecular weight cutoffs that range from 1,000 to 300,000 Da, and larger thresholds of filtration are measured in µm.
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V-ATPase is a complex situated mainly in the membrane of the vacuolar system of cells that uses ATP as an energy source to enable storage of solutes in the vacuolar system against their concentration gradient. In most living creatures, it is a necessary component for life but Nelson discovered that yeast can overcome the constraints of non-function V-ATPase when living in high acidity. This finding opened the door for research of the proteins comprising this complex and the genes coding for them, many of which were discovered in his lab. The structure of one sub-unit was solved by x-ray crystallography in Nelson's group as well.
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Several salt-tolerance mechanisms of H. werneckii have been studied on molecular level. For example, it is known that its major compatible solutes are glycerol, erythritol, arabitol, and mannitol; melanin accumulation of the cell wall aids in retention of at least glycerol inside of the cell. Several components of the high osmolarity glycerol (HOG) signalling pathway (which controls responses to osmotic shock) have been studied in detail and some seem to differ in function compared to their counterparts in Saccharomyces cerevisiae. Adaptation to high concentrations of salt are also accompanied by changes in membrane lipid composition, mainly by increasing the unsaturation of the phospholipid fatty acids.
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There was opposition to this new view, but by the time of his review in the 1981 Annual Review of Plant Physiology further experimental work made it clear that he was right. In the period of the 1970s and 1980s he continued to make major contributions to the new thinking. He showed that two distinct proton pumping ATPases were present in plasmalemma and tonoplast, with different inhibitor characteristics. He also showed that the gradients of pH and membrane potential generated by the primary proton pump in the plasmalemma could be used to drive secondary active transport of other solutes, sugars, amino acids and other ions.
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There are three fundamental ways plants uptake nutrients through the root: # Simple diffusion occurs when a nonpolar molecule, such as O2, CO2, and NH3 follows a concentration gradient, moving passively through the cell lipid bilayer membrane without the use of transport proteins. # Facilitated diffusion is the rapid movement of solutes or ions following a concentration gradient, facilitated by transport proteins. # Active transport is the uptake by cells of ions or molecules against a concentration gradient; this requires an energy source, usually ATP, to power molecular pumps that move the ions or molecules through the membrane. Nutrients can be moved within plants to where they are most needed.
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Thus, gelatin filtration works by freezing a gelatin- containing, water-based solution and then allowing it to thaw in a mesh strainer at just above the freezing temperature of water. The gelatin and other solutes concentrate in the unfrozen, associated water, and the gelatin forms a stable network through cross-linking, just as it would in a standard gel. This stable network acts as a filter, trapping large particles of fat or protein, while allowing water and smaller, flavor-active compounds to pass. As the bulk water melts, it passes first through the gelatin network and then through the mesh strainer, into a receiving vessel.
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Ole Albert Lamm (December 25, 1902 in Gothenburg - August 14, 1964 in Stockholm), was a Swedish physical chemist whose research included diffusion and sedimentation phenomena. Lamm was a graduate student under Nobel Prize laureate The Svedberg at Uppsala University and received his doctorate in 1937 with the thesis Measurements of concentration gradients in sedimentation and diffusion by refraction methods: Solubility properties of potato starch.Libris record In 1945, he was appointed professor of theoretical chemistry, from 1953 physical chemistry, at the Royal Institute of Technology in Stockholm. Lamm introduced the Lamm equation which describes the concentration distribution of solutes resulting from sedimentation and diffusion under ultracentrifugation in typical sector-shaped cells.
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With surface chemistries that are weakly ionic, the choice of pH can affect the ionic nature of the column chemistry. Properly adjusted, the pH can be set to reduce the selectivity toward functional groups with the same charge as the column, or enhance it for oppositely charged functional groups. Similarly, the choice of pH affects the polarity of the solutes. However, for column surface chemistries that are strongly ionic, and thus resistant to pH values in the mid-range of the pH scale (pH 3.5-8.5), these separations will be reflective of the polarity of the analytes alone, and thus might be easier to understand when doing methods development.
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High levels of stimulation and subsequent ionic influx through activated ion channels can result in cellular swelling as osmotically-obliged water is drawn into neurons along with ionic solutes. This phenomenon is known as excitotoxicity. KCC2 has been shown to be activated by cell-swelling, and may therefore play a role in eliminating excess ions following periods of high stimulation in order to maintain steady-state neuronal volume and prevent cells from bursting. This role may also account for the fact that KCC2 has been known to colocalize near excitatory synapses, even though its primary role is to establish the chloride gradient for postsynaptic inhibition.
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The use of membrane vesicles from various sources has become a standard tool for testing models and performing hypothesis-driven research. Kaback demonstrated quantitatively that an electrochemical H+ gradient is the immediate driving force for accumulation of many different solutes. Peter Mitchell who conceived and formulated the ‘’Chemiosmotic Hypothesis’’ considered these findings to be the most conclusive experimental support for the Hypothesis with respect to membrane transport. Kaback extended his interest to the molecular mechanism of membrane transport by focusing on the lactose permease of Escherichia coli (LacY; aka the lactose/H+ symporter), which is now a paradigm for the Major Facilitator Superfamily, arguably the largest group of membrane transport proteins.
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Adding cobalt or molybdenum can cause the steel to retain its hardness, even at red-hot temperatures, forming high-speed steels. Often, small amounts of many different elements are added to the steel to give the desired properties, rather than just adding one or two. Most alloying elements (solutes) have the benefit of not only increasing hardness, but also lowering both the martensite start temperature and the temperature at which austenite transforms into ferrite and cementite. During quenching, this allows a slower cooling rate, which allows items with thicker cross-sections to be hardened to greater depths than is possible in plain carbon-steel, producing more uniformity in strength.
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Ladanyi contributed to research on the molecular aspects of solvation thermodynamics in polar liquids. She and her coworkers calculated quantities of significance in electronic spectroscopy and electron transfer reactions. This work generally found that solvation free energies exhibit relatively weak deviations from linearity, but that nonlinearities are more evident in free energy derivatives. She considered both simple model solutes and realistic representations of chromophores used in experiments in supercritical CO2 and CHF3 to investigate how the density- and temperature- dependence of solvatochromic shifts in solute electronic spectra relate to local solvation structure and how different types of solute-solvent interactions contribute to the predicted shifts.
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It was not until 1992 that the first aquaporin, 'aquaporin-1' (originally known as CHIP 28), was reported by Peter Agre, of Johns Hopkins University. In 1999, together with other research teams, Agre reported the first high-resolution images of the three- dimensional structure of an aquaporin, namely, aquaporin-1. Further studies using supercomputer simulations identified the pathway of water as it moved through the channel and demonstrated how a pore can allow water to pass without the passage of small solutes. The pioneering research and subsequent discovery of water channels by Agre and his colleagues won Agre the Nobel Prize in Chemistry in 2003.
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Comparison of transport proteins Antiporter illustration An antiporter (also called exchanger or counter-transporter) is a cotransporter and integral membrane protein involved in secondary active transport of two or more different molecules or ions across a phospholipid membrane such as the plasma membrane in opposite directions, one into the cell and one out of the cell. Na+/H+ antiporters have been reviewed. In secondary active transport, one species of solute moves along its electrochemical gradient, allowing a different species to move against its own electrochemical gradient. This movement is in contrast to primary active transport, in which all solutes are moved against their concentration gradients, fueled by ATP.
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While the high strength of steel results when diffusion and precipitation is prevented (forming martensite), most heat- treatable alloys are precipitation hardening alloys, that depend on the diffusion of alloying elements to achieve their strength. When heated to form a solution and then cooled quickly, these alloys become much softer than normal, during the diffusionless transformation, but then harden as they age. The solutes in these alloys will precipitate over time, forming intermetallic phases, which are difficult to discern from the base metal. Unlike steel, in which the solid solution separates into different crystal phases (carbide and ferrite), precipitation hardening alloys form different phases within the same crystal.
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In any form of chromatography, the rate at which the solute moves down the column is a direct reflection of the percentage of time the solute spends in the mobile phase. To achieve separation in either elution or displacement chromatography, there must be appreciable differences in the affinity of the respective solutes for the stationary phase. Both methods rely on movement down the column to amplify the effect of small differences in distribution between the two phases. Distribution between the mobile and stationary phases is described by the binding isotherm, a plot of solute bound to (or partitioned into) the stationary phase as a function of concentration in the mobile phase.
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As there is no enzymatic proteolytic activity at this stage, the level of H-NMR, a spectrum used to determine the structure, is still constant because there is no change going on. However, when pepsin takes action, TD-NMR, a special technique used for measuring mobile water population with macromolecular solutes, reveals that progressive unbundling of meat fibers helps pepsin activity to digest. TD-NMR data proves that bolus structure changes considerably during the first part of digestion and water molecules, consequently, leave the spaces inside the myofibrils and fiber bundles. This results in a low level of water that can be detected in duodenal stage.
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At the onset of this condition, fluid outside the cells has an excessively low amount of solutes, such as sodium and other electrolytes, in comparison to fluid inside the cells, causing the fluid to move into the cells to balance its concentration. This causes the cells to swell. In the brain, this swelling increases intracranial pressure (ICP), which leads to the first observable symptoms of water intoxication: headache, personality changes, changes in behavior, confusion, irritability, and drowsiness. These are sometimes followed by difficulty breathing during exertion, muscle weakness & pain, twitching, or cramping, nausea, vomiting, thirst, and a dulled ability to perceive and interpret sensory information.
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The advantages of this method include good separation of large molecules from the small molecules with a minimal volume of eluate, and that various solutions can be applied without interfering with the filtration process, all while preserving the biological activity of the particles to separate. The technique is generally combined with others that further separate molecules by other characteristics, such as acidity, basicity, charge, and affinity for certain compounds. With size exclusion chromatography, there are short and well-defined separation times and narrow bands, which lead to good sensitivity. There is also no sample loss because solutes do not interact with the stationary phase.
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Heteroarm polymers have been shown to aggregate into particularly interesting supramolecular formations such as stars, segmented ribbons, and core-shell-corona micellar assemblies depending on their arms' solubility in solution, which can be affected by changes in temperature, pH, solvent, etc. These self-assembly properties have implications for solubility of the whole star polymers themselves and for other solutes in solution. For Heteroarm polymers, increasing the molecular weight of soluble chains increases the overall solubility of the star. Certain Heteroarm star-block polymers have been shown to stabilize water-organic solvent emulsions, while others have demonstrated the ability to increase the solubility of inorganic salts in organic solutions.
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The protein binding principles in EBA are the same as in classical column chromatography and the common ion-exchange, hydrophobic interaction and affinity chromatography ligands can be used. After the adsorption step is complete, the fluidized bed is washed to flush out any remaining particulates. Elution of the adsorbed proteins was commonly performed with the eluent flow in the reverse direction; that is, as a conventional packed bed, in order to recover the adsorbed solutes in a smaller volume of eluent. However, a new generation of EBA columns has been developed, which maintain the bed in the expanded state during this phase, producing high-purity, high yields of e.g.
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The microdialysis technique requires the insertion of a small microdialysis catheter (also referred to as microdialysis probe) into the tissue of interest. The microdialysis probe is designed to mimic a blood capillary and consists of a shaft with a semipermeable hollow fiber membrane at its tip, which is connected to inlet and outlet tubing. The probe is continuously perfused with an aqueous solution (perfusate) that closely resembles the (ionic) composition of the surrounding tissue fluid at a low flow rate of approximately 0.1-5μL/min. Once inserted into the tissue or (body)fluid of interest, small solutes can cross the semipermeable membrane by passive diffusion.
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A depletion force is an effective attractive force that arises between large colloidal particles that are suspended in a dilute solution of depletants, which are smaller solutes that are preferentially excluded from the vicinity of the large particles. One of the earliest reports of depletion forces that lead to particle coagulation is that of Bondy, who observed the separation or 'creaming' of rubber latex upon addition of polymer depletant molecules (sodium alginate) to solution. More generally, depletants can include polymers, micelles, osmolytes, ink, mud, or paint dispersed in a continuous phase. Depletion forces are often regarded as entropic forces, as was first explained by the established Asakura–Oosawa model.
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In addition, interactions can be homophilic (between identical proteins) or heterophilic (between different proteins). Similar to adherens junctions, the intracellular domains of tight junctions interact with different scaffold proteins, adapter proteins and signaling complexes to regulate cytoskeletal linking, cell polarity, cell signaling and vesical trafficking. Tight junctions provide a narrow but modifiable seal between adjacent cells in the epithelial layer and thereby provide selective paracellular transport of solutes. While previously thought to be static structures, tight junctions are now known to be dynamic and can change the size of the opening between cells and thereby adapt to the different states of development, physiologies and pathologies.
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A colloid being something between a solution and a suspension, where Brownian motion is sufficient to prevent sedimentation. The idea of a semipermeable membrane, a barrier that is permeable to solvent but impermeable to solute molecules was developed at about the same time. The term osmosis originated in 1827 and its importance to physiological phenomena realized, but it wasn’t until 1877, when the botanist Pfeffer proposed the membrane theory of cell physiology. In this view, the cell was seen to be enclosed by a thin surface, the plasma membrane, and cell water and solutes such as a potassium ion existed in a physical state like that of a dilute solution.
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This is known as native PAGE. Adding SDS solves this problem, as it binds to and unfolds the protein, giving a near uniform negative charge along the length of the polypeptide. Urea (; mW: 60.06) is a chaotropic agent that increases the entropy of the system by interfering with intramolecular interactions mediated by non-covalent forces such as hydrogen bonds and van der Waals forces. Macromolecular structure is dependent on the net effect of these forces, therefore it follows that an increase in chaotropic solutes denatures macromolecules, Ammonium persulfate (APS) (; mW: 228.2) is a source of free radicals and is often used as an initiator for gel formation.
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For example, in co-transport use is made of the gradients of certain solutes to transport a target compound against its gradient, causing the dissipation of the solute gradient. It may appear that, in this example, there is no energy use, but hydrolysis of the energy provider is required to establish the gradient of the solute transported along with the target compound. The gradient of the co-transported solute will be generated through the use of certain types of proteins called biochemical pumps. The discovery of the existence of this type of transporter protein came from the study of the kinetics of cross-membrane molecule transport.
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For certain solutes it was noted that the transport velocity reached a plateau at a particular concentration above which there was no significant increase in uptake rate, indicating a log curve type response. This was interpreted as showing that transport was mediated by the formation of a substrate- transporter complex, which is conceptually the same as the enzyme-substrate complex of enzyme kinetics. Therefore, each transport protein has an affinity constant for a solute that is equal to the concentration of the solute when the transport velocity is half its maximum value. This is equivalent in the case of an enzyme to the Michaelis–Menten constant.
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Passive diffusion on a cell membrane. Diffusion is the net movement of material from an area of high concentration to an area with lower concentration. The difference of concentration between the two areas is often termed as the concentration gradient, and diffusion will continue until this gradient has been eliminated. Since diffusion moves materials from an area of higher concentration to an area of lower concentration, it is described as moving solutes "down the concentration gradient" (compared with active transport, which often moves material from area of low concentration to area of higher concentration, and therefore referred to as moving the material "against the concentration gradient").
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For a substance in solution (solute), the standard state is the hypothetical state it would have at the standard state molality or amount concentration but exhibiting infinite-dilution behavior. The reason for this unusual definition is that the behavior of a solute at the limit of infinite dilution is described by equations which are very similar to the equations for ideal gases. Hence taking infinite-dilution behavior to be the standard state allows corrections for non-ideality to be made consistently for all the different solutes. Standard state molality is 1 mol kg−1, while standard state amount concentration is 1 mol dm−3.
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Adenosine triphosphate Adenosine diphosphate Adenosine monophosphate ATPases (, adenylpyrophosphatase, ATP monophosphatase, triphosphatase, SV40 T-antigen, adenosine 5'-triphosphatase, ATP hydrolase, complex V (mitochondrial electron transport), (Ca2+ \+ Mg2+)-ATPase, HCO3−-ATPase, adenosine triphosphatase) are a class of enzymes that catalyze the decomposition of ATP into ADP and a free phosphate ion or the inverse reaction. This dephosphorylation reaction releases energy, which the enzyme (in most cases) harnesses to drive other chemical reactions that would not otherwise occur. This process is widely used in all known forms of life. Some such enzymes are integral membrane proteins (anchored within biological membranes), and move solutes across the membrane, typically against their concentration gradient.
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Schematic of semipermeable membrane during hemodialysis, where blood is red, dialysing fluid is blue, and the membrane is yellow. Semipermeable membrane is a type of biological or synthetic, polymeric membrane that will allow certain molecules or ions to pass through it by Osmosis—or occasionally by more specialized processes of facilitated diffusion, passive transport or active transport. The rate of passage depends on the pressure, concentration, and temperature of the molecules or solutes on either side, as well as the permeability of the membrane to each solute. Depending on the membrane and the solute, permeability may depend on solute size, solubility, properties, or chemistry.
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Tight junctions represent one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the paracellular space. The protein encoded by this immunoglobulin superfamily gene member is localized in the tight junctions between high endothelial cells. Unlike other proteins in this family, this protein is unable to adhere to leukocyte cell lines and only forms weak homotypic interactions. The encoded protein is a member of the junctional adhesion molecule protein family and acts as a receptor for another member of this family.
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Osmosis may be used directly to achieve separation of water from a solution containing unwanted solutes. A "draw" solution of higher osmotic pressure than the feed solution is used to induce a net flow of water through a semi- permeable membrane, such that the feed solution becomes concentrated as the draw solution becomes dilute. The diluted draw solution may then be used directly (as with an ingestible solute like glucose), or sent to a secondary separation process for the removal of the draw solute. This secondary separation can be more efficient than a reverse osmosis process would be alone, depending on the draw solute used and the feedwater treated.
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Thiazide-type diuretics such as hydrochlorothiazide act on the distal convoluted tubule and inhibit the sodium-chloride symporter leading to a retention of water in the urine, as water normally follows penetrating solutes. Frequent urination is due to the increased loss of water that has not been retained from the body as a result of a concomitant relationship with sodium loss from the convoluted tubule. The short-term anti-hypertensive action is based on the fact that thiazides decrease preload, decreasing blood pressure. On the other hand, the long-term effect is due to an unknown vasodilator effect that decreases blood pressure by decreasing resistance.
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The porcupine river stingray (Potamotrygon histrix, sometimes incorrectly modified to Potamotrygon hystrix) is a species of river stingray in the family Potamotrygonidae, the type of the Potamotrygon genus. It is found in the basins of the Paraná and Paraguay River basins in South America. Most chemical weathering of minerals seems to take place in the upland drainage basins rather than on the floodplains, and most major solutes display conservative mixing in the river-floodplain system.Hamilton, Stephen K., Sippel, Suzanne J., Calheiros, DÓbora F., Melack, John M., ( 1997), An anoxic event and other biogeochemical effects of the Pantanal wetland on the Paraguay River, Limnology and Oceanography, 42, doi: 10.4319/lo.1997.42.2.0257.
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Landscape limnology is the spatially explicit study of lakes, streams, and wetlands as they interact with freshwater, terrestrial, and human landscapes to determine the effects of pattern on ecosystem processes across temporal and spatial scales. Limnology is the study of inland water bodies inclusive of rivers, lakes, and wetlands; landscape limnology seeks to integrate all of these ecosystem types. The terrestrial component represents spatial hierarchies of landscape features that influence which materials, whether solutes or organisms, are transported to aquatic systems; aquatic connections represent how these materials are transported; and human activities reflect features that influence how these materials are transported as well as their quantity and temporal dynamics.Soranno, P.A., K.E. Webster, K.S. Cheruvelil and M.T. Bremigan. 2009.
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Generally, higher solubility is seen when solvent and solute atoms are similar in atomic size (15% according to the Hume-Rothery rules) and adopt the same crystal structure in their pure form. Examples of completely miscible binary systems are Cu-Ni and the Ag-Au face-centered cubic (FCC) binary systems, and the Mo-W body-centered cubic (BCC) binary system. Interstitial solutes in lattice Interstitial solid solutions form when the solute atom is small enough (radii up to 57% the radii of the parent atoms) to fit at interstitial sites between the solvent atoms. The atoms crowd into the interstitial sites, causing the bonds of the solvent atoms to compress and thus deform.
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That negative pressure pulls the center of the cell inward until the cell wall can no longer withstand the strain. The inward pressure causes the majority of the collapse to occur in the central region of the cell, pushing the organelles within the remaining cytoplasm against the cell walls. Unlike in plasmolysis (a phenomenon that does not occur in nature), the plasma membrane maintains its connections with the cell wall both during and after cellular collapse. Cytorrhysis of plant cells can be induced in laboratory settings if they are placed in a hypertonic solution where the size of the solutes in the solution inhibit flow through the pores in the cell wall matrix.
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In CEC positive ions of the electrolyte added along with the analyte accumulate in the electrical double layer of the particles of the column packing on application of an electric field they move towards the cathode and drag the liquid mobile phase with them. The relationship between the linear velocity u of the liquid in the capillary and the applied electric field is given by the Smoluchowski equation as : u = \epsilon_r\epsilon_0 \zeta E \eta where ζ is the potential across the Stern layer (zeta potential), E is the electric field strength, and η is the viscosity of the solvent. Separation of components in CEC is based on interactions between the stationary phase and differential electrophoretic migration of solutes.
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Ronald Kaback became interested in membrane transport at a time when studies on biological membranes were in their infancy, and in the early phase of his career, he developed a cell-free membrane system to study active transport. The system consisted of osmotically sealed membrane vesicles of defined orientation (right-side-out) that catalyze active transport essentially as well as intact cells, but lack subsequent metabolism of the solutes accumulated. These vesicles were dubbed Kabackosomes by the Dutch scientist Wilhelmus N. Konings, Kaback's close friend and early collaborator. In addition to transforming the field of transport from phenomenology to biochemistry, this seminal development caused him to forego the practice of pediatrics for a career in basic science.
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Tight junctions are normally present in epithelial and endothelial tissues, where they seal gaps and regulate paracellular transport of solutes and extracellular fluids in these tissues that function as barriers. Tight junction is formed by transmembrane proteins, including claudins, occludins and tricellulins, that bind closely to each other on adjacent membranes in a homophilic manner. Similar to anchoring junctions, intracellular domains of these tight junction proteins are bound with scaffold proteins that keep these proteins in clusters and link them to actin filaments in order to maintain structure of the tight junction. Claudins, essential for formation of tight junctions, form paracellular pores which allow selective passage of specific ions across tight junctions making the barrier selectively permeable.
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The ascending limb of the loop of Henle receives an even lower volume of fluid and has different characteristics compared to the descending limb. In the ascending portion, the loop becomes impermeable to water and the cells of the loop actively reabsorb solutes from the luminal fluid; therefore water is not reabsorbed and ions are readily reabsorbed. As ions leave the lumen via the Na-K-2Cl symporter and the Na-H antiporter, the concentration becomes more and more hypotonic until it reaches approximately 100-150 mOsm/L. The ascending limb is also called the diluting segment of the nephron because of its ability to dilute the fluid in the loop from 1200 mOsm/L to 100 mOsm/L.
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The thoracic duct drains into the left subclavian vein, near its junction with the left internal jugular vein. It carries lymph (water and solutes) from the lymphatic system, as well as chylomicrons or chyle, formed in the intestines from dietary fat and lipids, allowing these to enter the bloodstream; the products of fats and lipids can then be carried by the bloodstream to the hepatic portal vein, and then finally to the liver, making it so that the left subclavian vein plays a key role in the absorption of these fats and lipids. The right lymphatic duct drains its lymph into the junction of the right internal jugular vein, and the right subclavian vein.
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A Conversation With Peter Agre: Using a Leadership Role to Put a Human Face on Science, By Claudia Dreifus, New York Times, January 26, 2009 Aquaporins selectively conduct water molecules in and out of the cell, while preventing the passage of ions and other solutes. Also known as water channels, aquaporins are integral membrane pore proteins. Some of them, known as aquaglyceroporins, also transport other small uncharged dissolved molecules including ammonia, CO2, glycerol, and urea. For example, the aquaporin 3 channel has a pore width of 8–10 Ångströms and allows the passage of hydrophilic molecules ranging between 150 and 200 Da. However, the water pores completely block ions including protons, essential to conserve the membrane's electrochemical potential difference.
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Given two compounds that differ in polarity, the more polar compound has a stronger interaction with the silica and is, therefore, better able to displace the mobile phase from the available binding sites. As a consequence, the less polar compound moves higher up the plate (resulting in a higher Rf value). If the mobile phase is changed to a more polar solvent or mixture of solvents, it becomes better at binding to the polar plate and therefore displacing solutes from it, so all compounds on the TLC plate will move higher up the plate. It is commonly said that "strong" solvents (eluents) push the analyzed compounds up the plate, whereas "weak" eluents barely move them.
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The primary function of the plant cuticle is as a water permeability barrier that prevents evaporation of water from the epidermal surface, and also prevents external water and solutes from entering the tissues. In addition to its function as a permeability barrier for water and other molecules (prevent water loss), the micro and nano-structure of the cuticle have specialised surface properties that prevent contamination of plant tissues with external water, dirt and microorganisms. Aerial organs of many plants, such as the leaves of the sacred lotus (Nelumbo nucifera) have ultra-hydrophobic and self-cleaning properties that have been described by Barthlott and Neinhuis (1997). The lotus effect has applications in biomimetic technical materials.
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The cleansed blood is then returned via the circuit back to the body. Ultrafiltration occurs by increasing the hydrostatic pressure across the dialyzer membrane This usually is done by applying a negative pressure to the dialysate compartment of the dialyzer. This pressure gradient causes water and dissolved solutes to move from blood to dialysate and allows the removal of several litres of excess fluid during a typical 4-hour treatment. In the United States, hemodialysis treatments are typically given in a dialysis center three times per week (due in the United States to Medicare reimbursement rules); however, as of 2005 over 2,500 people in the United States are dialyzing at home more frequently for various treatment lengths.
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Equilibrium segregation is associated with the lattice disorder at interfaces, where there are sites of energy different from those within the lattice at which the solute atoms can deposit themselves. The equilibrium segregation is so termed because the solute atoms segregate themselves to the interface or surface in accordance with the statistics of thermodynamics in order to minimize the overall free energy of the system. This sort of partitioning of solute atoms between the grain boundary and the lattice was predicted by McLean in 1957. Non-equilibrium segregation, first theorized by Westbrook in 1964, occurs as a result of solutes coupling to vacancies which are moving to grain boundary sources or sinks during quenching or application of stress.
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Her main environment of interest is the largest actively flowing aquifer system on Earth, the fluids circulating through oceanic crust underlying the oceans and sediments. There is a vast flow of fluid exchanging between ocean basins and crustal reservoirs and mediating transport of heat, solutes, genetic material, microorganisms, and viruses. Despite our advancing knowledge about life in the deep ocean, our understanding of microorganisms in the rocky oceanic crust and the fluids flowing through it is limited. The biogeochemical consequences of an extensive population of microbes living in the subseafloor remains unknown, and the potential for production of new biomass within the crust is rarely considered in traditional oceanographic paradigms of carbon cycling or microbial food webs.
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Roy has developed silicon nanopore membranes (SNM) to achieve high-efficiency blood ultrafiltration while selectively retaining specific solutes and serving as an immunoprotective barrier for encapsulated cells. The SNM are the fundamental underlying technology for the development of an implantable bioartificial kidney. Using this technology, he is now developing an implantable bioartificial pancreas (iBAP). Previous attempts to develop a bioartificial pancreas have been severely limited by insufficient mass transfer and a limited supply of beta cells, but Roy says that ultra-high hydraulic permeability characteristic of the SNM will enable appropriate mass transport (especially oxygen, glucose, and insulin) to achieve optimal beta cell performance, while the ultra-selective pore characteristic of the SNM enable unprecedented immunoisolation.
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Unlike many other types of echinoderm, solute homalozoans lack radial symmetry (such as the five limbs of a starfish).A. B. Smith Deuterostome phylogeny and the interpretation of problematic fossil echinoderms, page 543-544 in Thomas Heinzeller, James H. Nebelsick Echinoderms: München, CRC Press, 2004 , Solutes are the sole order of the class Homoiostelea. Solute fossils have an irregularly shaped flattened body covered in calcite plates, and are up to about 10 cm long. The body has two appendages, interpreted as a "feeding arm" at one end, bearing tube feet at its end, and a "stele" at the other, which may have been used by the animal to propel itself along the sea floor.
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As the blood and the surrounding cells continually add and remove substances from the interstitial fluid, its composition continually changes. Water and solutes can pass between the interstitial fluid and blood via diffusion across gaps in capillary walls called intercellular clefts; thus, the blood and interstitial fluid are in dynamic equilibrium with each other. Interstitial fluid forms at the arterial (coming from the heart) end of capillaries because of the higher pressure of blood compared to veins, and most of it returns to its venous ends and venules; the rest (up to 10%) enters the lymph capillaries as lymph. Thus, lymph when formed is a watery clear liquid with the same composition as the interstitial fluid.
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The endodermis does not allow gas bubbles to enter the xylem and helps prevent embolisms from occurring in the water column. Passage cells are endodermal cells of older roots which have retained thin walls and Casparian strips rather than becoming suberized and waterproof like the other cells around them, to continue to allow some symplastic flow to the inside. Experimental evidence suggests that passage cells function to allow transfer of solutes such as calcium and magnesium into the stele, in order to eventually reach the transpiration system. For the most part, however, old roots seal themselves off at the endodermis, and only serve as a passageway for water and minerals taken up by younger roots "downstream".
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Distribution law or the Nernst's distribution law gives a generalisation which governs the distribution of a solute between two non miscible solvents. This law was first given by Nernst who studied the distribution of several solutes between different appropriate pairs of solvents. C1/C2 = Kd Where Kd is called the distribution coefficient or the partition coefficient. Concentration of X in solvet A/concentration of X in solvent B=Kď If C1 denotes the concentration of solute X in solvent A & C2 denotes the concentration of solute X in solvent B; Nernst's distribution law can be expressed as C1/C2 = Kd. This law is only valid if the solute is in the same molecular form in both the solvents.
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Penicillium spinulosum is psychrophilic, meaning that it is able to grow and reproduce at low temperature, and xerophile as it can germinate in decreased water activity environment (down to 0.8 Aw) by producing compatible solutes using enzyme systems. In vitro, P. spinulosum does not grow at 37 °C. Jussila stated that no mycotoxin production by P. spinulosum have been reported, however, based on the work of Overy and colleagues, a mixed culture of P. glabrum and P. spinulosum was involved in chestnuts spoilage and mycotoxin production. Colonies growth and germination of Penicillium spinulosum were extremely sensitive to several different disinfectants and preservatives, among them, potassium sorbate and Suma Bac imposed the strongest inhibition effect.
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By measuring the time required for the cells to swell past their elastic limit, the rate at which solutes entered the cells could be estimated by the accompanying change in cell volume. He also found that there was an apparent nonsolvent volume of about 50% in red blood cells and later showed that this includes water of hydration in addition to the protein and other nonsolvent components of the cells. Ernest Overton (a distant cousin of Charles Darwin) first proposed the concept of a lipid (oil) plasma membrane in 1899. The major weakness of the lipid membrane was the lack of an explanation of the high permeability to water, so Nathansohn (1904) proposed the mosaic theory.
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In renal physiology, reabsorption or tubular reabsorption is the process by which the nephron removes water and solutes from the tubular fluid (pre-urine) and returns them to the circulating blood. It is called reabsorption (and not absorption) both because these substances have already been absorbed once (particularly in the intestines) and because the body is reclaiming them from a postglomerular fluid stream that is well on its way to becoming urine (that is, they will soon be lost to the urine unless they are reclaimed). Substances are reabsorbed from the tubule into the peritubular capillaries. This happens as a result of sodium transport from the lumen into the blood by the Na+/K+ATPase in the basolateral membrane of the epithelial cells.
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Diagram of a crenated leaf Crenation (from modern Latin crenatus meaning 'scalloped or notched', from popular Latin crena meaning 'notch') in botany and zoology, describes an object's shape, especially a leaf or shell, as being round-toothed or having a scalloped edge. The descriptor can apply to objects of different types, including cells, where one mechanism of crenation is the contraction of a cell after exposure to a hypertonic solution, due to the loss of water through osmosis. In a hypertonic environment, the cell has a lower concentration of solutes than the surrounding extracellular fluid, and water diffuses out of the cell by osmosis, causing the cytoplasm to decrease in volume. As a result, the cell shrinks and the cell membrane develops abnormal notchings.
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Potomania is a specific hypo-osmolality syndrome related to massive consumption of beer, which is poor in solutes and electrolytes. With little food or other sources of electrolytes, consumption of large amounts of beer or other dilute alcoholic drinks leads to electrolyte disturbances, where the body does not have enough nutrients known as electrolytes, namely sodium, potassium, and magnesium. The symptoms of potomania are similar to other causes of hyponatremia and include dizziness, muscular weakness, neurological impairment and seizures, all related to hyponatremia and hypokalaemia. While the symptoms of potomania are similar to other causes of hyponatremia and acute water intoxication, it should be considered an independent clinical entity because of its often chronic nature of onset, pathophysiology, and presentation of symptoms.
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After completing a BSc (Special) degree from Imperial College in 1961, he conducted biochemical research with Henrik Lundegårdh at the University of Upsala, Sweden for 1 year. Then he continued his postgraduate research at Oxford University where he received his D.Phil in 1966 for a thesis concerned with the processes of ion uptake in plant roots. During his post-doctoral fellowship at the University of Cambridge, he was in the laboratory of Enid MacRobbie and studied the ionic status of chloroplasts. He investigated the role of compatible solutes in energy transduction in chloroplasts and wrote the paper Ionic Relations of Chloroplasts in Vivo published in Nature, showing that chloroplasts have much higher salt concentrations than the surrounding cytoplasm and that this difference is involved in energy transduction.
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In many simulations of a solute-solvent system the main focus is on the behavior of the solute with little interest of the solvent behavior particularly in those solvent molecules residing in regions far from the solute molecule. Solvents may influence the dynamic behavior of solutes via random collisions and by imposing a frictional drag on the motion of the solute through the solvent. The use of non-rectangular periodic boundary conditions, stochastic boundaries and solvent shells can all help reduce the number of solvent molecules required and enable a larger proportion of the computing time to be spent instead on simulating the solute. It is also possible to incorporate the effects of a solvent without needing any explicit solvent molecules present.
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The subglacial water column is influenced by the exchange of water between lakes and streams under ice sheets through the subglacial drainage system; this behavior likely plays an important role in biogeochemical processes, leading to changes in microbial habitat, particularly regarding oxygen and nutrient concentrations. Hydrologic connectivity of subglacial lakes also alters water residence times, or amount of time that water stays within the subglacial lake reservoir. Longer residence times, such as those found beneath the interior Antarctic Ice Sheet, would lead to greater contact time between the water and solute sources, allowing for greater accumulation of solutes than in lakes with shorter residence times. Estimated residence times of currently studied subglacial lakes range from about 13,000 years in Lake Vostok to just decades in Lake Whillans.
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When the urine becomes supersaturated (when the urine solvent contains more solutes than it can hold in solution) with one or more calculogenic (crystal-forming) substances, a seed crystal may form through the process of nucleation. Heterogeneous nucleation (where there is a solid surface present on which a crystal can grow) proceeds more rapidly than homogeneous nucleation (where a crystal must grow in a liquid medium with no such surface), because it requires less energy. Adhering to cells on the surface of a renal papilla, a seed crystal can grow and aggregate into an organized mass. Depending on the chemical composition of the crystal, the stone-forming process may proceed more rapidly when the urine pH is unusually high or low.
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Hildebrand challenged this popular view in a series of papers in the late 1960s and 1970s and concluded that methane has a just a 40% lower diffusivity in water than in carbon tetrachloride. If water was enclatherated or in an iceberg-type structure, then he predicted that this diffusivity difference between water and carbon tetrachloride ought to be significantly larger. This conflict of ideas still exists in the literature with publications between 2000 and 2010 for the clathrate-type hydrophobic hydration still being submitted in computer simulations of various types. There are papers, however, which cite Hildebrand's earlier criticisms of this model and suggest that hydrophobicity arises from the small size of water increasing the free energy required to develop a suitable cavity for certain solutes to occupy.
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Tubular reabsorption is the process by which solutes and water are removed from the tubular fluid and transported into the blood. It is called reabsorption (and not absorption) both because these substances have already been absorbed once (particularly in the intestines) and because the body is reclaiming them from a postglomerular fluid stream that is well on its way to becoming urine (that is, they will soon be lost to the urine unless they are reclaimed). Reabsorption is a two- step process beginning with the active or passive extraction of substances from the tubule fluid into the renal interstitium (the connective tissue that surrounds the nephrons), and then the transport of these substances from the interstitium into the bloodstream. These transport processes are driven by Starling forces, diffusion, and active transport.
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Ladanyi's work improved our understanding of the molecular mechanisms of solvation dynamics and their dependence on the solute, the solvent, and the perturbation in solute-solvent interactions. She was the first to show that the solvent's response is highly nonlinear for a variety of solutes in hydrogen bonding solvents and that solute-solvent hydrogen-bond formation is an important solvation mechanism in these systems. She developed methods, including instantaneous normal mode analysis, to uncover mechanistic information about solvation in systems that exhibit approximately linear response. With the advent of ultrafast spectroscopic techniques, the short- time nondiffusive dynamics in liquids became experimentally accessible and Ladanyi actively developed and implemented the theoretical framework for identifying and analyzing the molecular mechanisms contributing to the short- time response of fluids to perturbations relevant to experimental probes.
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The coupling between ATP hydrolysis and transport is more or less a strict chemical reaction, in which a fixed number of solute molecules are transported for each ATP molecule that is hydrolyzed; for example, 3 Na+ ions out of the cell and 2 K+ ions inward per ATP hydrolyzed, for the Na+/K+ exchanger. Transmembrane ATPases harness the chemical potential energy of ATP, because they perform mechanical work: they transport solutes in a direction opposite to their thermodynamically preferred direction of movement—that is, from the side of the membrane where they are in low concentration to the side where they are in high concentration. This process is considered active transport. For example, the blocking of the vesicular H+-ATPases would increase the pH inside vesicles and decrease the pH of the cytoplasm.
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Oasys FO Pilot System Brine concentration using forward osmosis may be achieved using a high osmotic pressure draw solution with a means to recover and regenerate it. One such process uses the ammonia-carbon dioxide (NH3/CO2) forward osmosis process invented at Yale University by Rob McGinnis, who subsequently founded Oasys Water to commercialize the technology. Because ammonia and carbon dioxide readily dissociate into gases using heat, the draw solutes can effectively be recovered and reused in a closed loop system, achieving separation through the conversion between thermal energy and osmotic pressure. NH3/CO2 FO brine concentration is was initially demonstrated in the oil and gas industry to treat produced water in the Permian Basin area of Texas, and is currently being used in power and manufacturing plants in China.
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Plateau mountains, such as the Catskills, are formed from the erosion of an uplifted plateau. In Earth science, erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transport it away to another location (not to be confused with weathering which involves no movement). The particulate breakdown of rock or soil into clastic sediment is referred to as physical or mechanical erosion; this contrasts with chemical erosion, where soil or rock material is removed from an area by its dissolving into a solvent (typically water), followed by the flow away of that solution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres.
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Of equal importance to the storage and movement of water in soil is the means by which plants acquire it and their nutrients. Most soil water is taken up by plants as passive absorption caused by the pulling force of water evaporating (transpiring) from the long column of water (xylem sap flow) that leads from the plant's roots to its leaves, according to the cohesion-tension theory. The upward movement of water and solutes (hydraulic lift) is regulated in the roots by the endodermis and in the plant foliage by stomatal conductance, and can be interrupted in root and shoot xylem vessels by cavitation, also called xylem embolism. In addition, the high concentration of salts within plant roots creates an osmotic pressure gradient that pushes soil water into the roots.
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The urine test strip test for specific gravity is based on the change in dissociation constant (pKa) of an anionic polyelectrolyte (poly-(methyl vinyl ether/maleic anhydride)) in an alkali medium that is ionised and releases hydrogen ions in proportion to the number of cations present in the solution. The greater the cation concentration of the urine the more hydrogen ions are released, thereby reducing the pH. The pad also includes bromothymol blue, which measures this change in pH. It should be remembered that the test strip only measures cation concentration, it is therefore possible that urine with a high concentration of non-ionic solutes (such as glucose or urea) or with high molecular weight compounds (such as the media used to provide radiographic contrast) will yield a result that will be erroneously lower than that measured by densitometry.
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The border zones between brain tissue "behind" the blood- brain barrier and zones "open" to blood signals in certain CVOs contain specialized hybrid capillaries that are leakier than typical brain capillaries, but not as permeable as CVO capillaries. Such zones exist at the border of the area postrema—nucleus tractus solitarii (NTS), and median eminence—hypothalamic arcuate nucleus. These zones appear to function as rapid transit regions for brain structures involved in diverse neural circuits—like the NTS and arcuate nucleus—to receive blood signals which are then transmitted into neural output. The permeable capillary zone shared between the median eminence and hypothalamic arcuate nucleus is augmented by wide pericapillary spaces, facilitating bidirectional flow of solutes between the two structures, and indicating that the median eminence is not only a secretory organ, but may also be a sensory organ.
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Between 1984 and 1989 he worked at the Mathematical Institute at the University of Oxford, largely on both applications and modelling within physiology and biology. In 1989 he joined a commercial consulting company working in the environmental sciences, building up a mathematical modelling group on multidisciplinary projects in the UK, Europe, US and Japan. His research ranged from the application of fractals to simulating subsurface environments (micro medium structure controlling channelling flow and dispersion phenomena at the macroscopic scale), and non-linear multiphase (solutes, gases, and especially colloidal) dispersion processes, fully coupled chemical-temperature–hydration systems, through to the development of frameworks for estimating uncertainties within risk assessments, and the analysis of public risk perception. He has developed models and methods for analyzing large networks (range dependent random graphs) occurring within the biosciences, such as in genome, proteome and metabolome interactions.
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The interstitial fluid is a reservoir and transportation system for nutrients and solutes distributing among organs, cells, and capillaries, for signaling molecules communicating between cells, and for antigens and cytokines participating in immune regulation. The composition and chemical properties of the interstitial fluid vary among organs and undergo changes in chemical composition during normal function, as well as during body growth, conditions of inflammation, and development of diseases, as in heart failure and chronic kidney disease. The total fluid volume of the interstitium during health is about 20% of body weight, but this space is dynamic and may change in volume and composition during immune responses and in conditions such as cancer, and specifically within the interstitium of tumors. The amount of interstitial fluid varies from about 50% of the tissue weight in skin to about 10% in skeletal muscle.
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Normally there are homeostatic processes in the body which maintain the concentration of body solutes within a narrow range, both inside and outside cells. The process occurs as follows: in some hypothalamic cells there are osmoreceptors which respond to hyperosmolality in body fluids by signalling the posterior pituitary gland to secrete ADH. This keeps serum sodium concentration - a proxy for solute concentration - at normal levels, prevents hypernatremia and turns off the osmoreceptors. Specifically, when the serum sodium rises above 142 mEq/L, ADH secretion is maximal (and thirst is stimulated as well); when it is below 135 mEq/L, there is no secretion. ADH activates V2 receptors on the basolateral membrane of principal cells in the renal collecting duct, initiating a cyclic AMP-dependent process that culminates in increased production of water channels (aquaporin 2), and their insertion into the cells’ luminal membranes.
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Firstly, the warm and humid climate allows for a rapid decomposition rate, meaning that nutrients do not stay present in or on top of the soil for long before being absorbed by the biota. Secondly, the acidity of the soil, caused by the few cation exchange sites to be occupied by hydrogen ions, increases the loss of minerals such as iron, aluminium oxides and phosphorus. Thirdly, leaching, which is the continuous downward movement and loss of solutes and minerals from the soil, happens regularly due to the heavy rainfall. An observer would not be able to tell that the soil is poor from the lush, dense vegetation in these wet tropical forests; but shortly after an area of forest is cleared for agriculture (usually through slash-and-burn) the small amount of nutrients wash away and the soil becomes infertile.
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Renal tubular acidosis (RTA) is a medical condition that involves an accumulation of acid in the body due to a failure of the kidneys to appropriately acidify the urine. In renal physiology, when blood is filtered by the kidney, the filtrate passes through the tubules of the nephron, allowing for exchange of salts, acid equivalents, and other solutes before it drains into the bladder as urine. The metabolic acidosis that results from RTA may be caused either by failure to reabsorb sufficient bicarbonate ions (which are alkaline) from the filtrate in the early portion of the nephron (the proximal tubule) or by insufficient secretion of hydrogen ions (which are acidic) into the latter portions of the nephron (the distal tubule). Although a metabolic acidosis also occurs in those with chronic kidney disease, the term RTA is reserved for individuals with poor urinary acidification in otherwise well-functioning kidneys.
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Studies in the brine shrimp have examined how water affects cell functions; these saw that a 20% reduction in the amount of water in a cell inhibits metabolism, with metabolism decreasing progressively as the cell dries out and all metabolic activity halting when the water level reaches 70% below normal. Although water is vital for life, the structure of this water in the cytosol is not well understood, mostly because methods such as nuclear magnetic resonance spectroscopy only give information on the average structure of water, and cannot measure local variations at the microscopic scale. Even the structure of pure water is poorly understood, due to the ability of water to form structures such as water clusters through hydrogen bonds. The classic view of water in cells is that about 5% of this water is strongly bound in by solutes or macromolecules as water of solvation, while the majority has the same structure as pure water.
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In a 2007 New York Times article, Harold McGee popularized an alternative method for clarifying broths, originating among chefs of the molecular gastronomy movement: gelatin filtration. Gelatin-filtration is a novel method of clarification, relying on some of the properties of a super-saturated solution of gelatin, created by freezing, to remove macroscopic particles that cause cloudiness from a water-based stock. This method is distinct from traditional consommé both in technique and in final product, as gelatin filtration results in a gelatin-free broth, while traditional consommé gives a final product rich in gelatin, with a correspondingly rich mouthfeel. Freezing a water-based solution converts all bulk water into ice crystals, but water associated with solutes—in the case of a soup stock, gelatin, fat, and flavor compounds—remains unfrozen to much lower temperatures; in practice, the freezing temperature of this associated water is well below the reach of conventional freezers.
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This increases the chance of contamination from any contacting surface, and so must be melted in vacuum induction-heating and special, water-cooled, copper crucibles.Metals Handbook: Properties and selection By ASM International – ASM International 1978 Page 407 However, some metals and solutes, such as iron and carbon, have very high melting-points and were impossible for ancient people to melt. Thus, alloying (in particular, interstitial alloying) may also be performed with one or more constituents in a gaseous state, such as found in a blast furnace to make pig iron (liquid-gas), nitriding, carbonitriding or other forms of case hardening (solid-gas), or the cementation process used to make blister steel (solid-gas). It may also be done with one, more, or all of the constituents in the solid state, such as found in ancient methods of pattern welding (solid-solid), shear steel (solid-solid), or crucible steel production (solid-liquid), mixing the elements via solid-state diffusion.
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For more than a century the prevailing hypothesis was that the flow of cerebrospinal fluid (CSF), which surrounds, but does not come in direct contact with the parenchyma of the CNS, could replace peripheral lymphatic functions and play an important role in the clearance of extracellular solutes. The majority of the CSF is formed in the choroid plexus and flows through the brain along a distinct pathway: moving through the cerebral ventricular system, into the subarachnoid space surrounding the brain, then draining into the systemic blood column via arachnoid granulations of the dural sinuses or to peripheral lymphatics along cranial nerve sheathes. Many researchers have suggested that the CSF compartment constitutes a sink for interstitial solute and fluid clearance from the brain parenchyma. However, the distances between the interstitial fluid and the CSF in the ventricles and subarachnoid space are too great for the efficient removal of interstitial macromolecules and wastes by simple diffusion alone.
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The largest and most important application of reverse osmosis is the separation of pure water from seawater and brackish waters; seawater or brackish water is pressurized against one surface of the membrane, causing transport of salt-depleted water across the membrane and emergence of potable drinking water from the low-pressure side. The membranes used for reverse osmosis have a dense layer in the polymer matrix—either the skin of an asymmetric membrane or an interfacially polymerized layer within a thin-film- composite membrane—where the separation occurs. In most cases, the membrane is designed to allow only water to pass through this dense layer while preventing the passage of solutes (such as salt ions). This process requires that a high pressure be exerted on the high-concentration side of the membrane, usually 2–17 bar (30–250 psi) for fresh and brackish water, and 40–82 bar (600–1200 psi) for seawater, which has around 27 bar (390 psi) natural osmotic pressure that must be overcome.
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In vascular plant biology, electro-osmosis is also used as an alternative or supplemental explanation for the movement of polar liquids via the phloem that differs from the cohesion-tension theory supplied in the mass flow hypothesis and others, such as cytoplasmic streaming.Clegg, C. J., Mackean, D. G. (2006) "Advanced Biology – principles & applications" Hodder Stoughton Publishers, pp. 340–343. Companion cells are involved in the "cyclic" withdrawal of ions (K+) from sieve tubes, and their secretion parallel to their position of withdrawal between sieve plates, resulting in polarisation of sieve plate elements alongside potential difference in pressure, and results in polar water molecules and other solutes present moved upward through the phloem. In 2003, St Petersburg University graduates applied direct electric current to 10 mm segments of mesocotyls of maize seedlings alongside one-year linden shoots; electrolyte solutions present in the tissues moved toward the cathode that was in place, suggesting that electro-osmosis might play a role in solution transport through conductive plant tissues.
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This adaptation is restricted to the moderately halophilic bacterial order Halanaerobiales, the extremely halophilic archaeal family Halobacteriaceae, and the extremely halophilic bacterium Salinibacter ruber. The presence of this adaptation in three distinct evolutionary lineages suggests convergent evolution of this strategy, it being unlikely to be an ancient characteristic retained in only scattered groups or passed on through massive lateral gene transfer. The primary reason for this is the entire intracellular machinery (enzymes, structural proteins, etc.) must be adapted to high salt levels, whereas in the compatible solute adaptation, little or no adjustment is required to intracellular macromolecules; in fact, the compatible solutes often act as more general stress protectants, as well as just osmoprotectants. Of particular note are the extreme halophiles or haloarchaea (often known as halobacteria), a group of archaea, which require at least a 2 M salt concentration and are usually found in saturated solutions (about 36% w/v salts).
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A unique feature of HYDRUS-2D was that it used a Microsoft Windows based Graphics User Interface (GUI) to manage the input data required to run the program, as well as for nodal discretization and editing, parameter allocation, problem execution, and visualization of results. It could handle flow regions delineated by irregular boundaries, as well as three-dimensional regions exhibiting radial symmetry about the vertical axis. The code includes the MeshGen2D mesh generator, which was specifically designed for variably-saturated subsurface flow and transport problems. The mesh generator may be used for defining very general domain geometries, and for discretizing the transport domain into an unstructured finite element mesh. HYDRUS-2D has been recently fully replaced with HYDRUS (2D/3D) as described below. The HYDRUS (2D/3D) (version 1) software package (Šimůnek et al., 2006;Šimůnek, J., M. Th. van Genuchten, and M. Šejna. 2006. The HYDRUS Software Package for Simulating Two- and Three-Dimensional Movement of Water, Heat, and Multiple Solutes in Variably-Saturated Media, Technical Manual, Version 1.0, PC Progress, Prague, Czech Republic, pp. 241.
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'Methods of pH homeostasis and energy generation in acidophiles' (with reference to Baker-Austin & Dopson, 2007 and Apel, Dugan, & Tuttle, 1980): (1) Direction of transmembrane electrochemical gradient (pH) and blocking of H+ by the cell membrane; (2) Reversed membrane potential through potassium transport, a modification towards maintaining a stable Donnan potential; (3) Secondary transporter protein; the H+ and Na+ gradient is harnessed to drive transport of nutrients and solutes; (4) Proton pump actively removes H+, balancing the energy gained from the H+ entry to the cytoplasm. (5) Vesicles containing protons avoid acidification of the cytoplasm, but still generate ATP from the electrochemical gradient (in A.ferrooxidans); (6) Uncouplers (uncharged compounds), such as organic acids, permeate the membrane and release their H+, leading to acidification of the cytoplasm; (7) To avoid this, heterotrophic acidophiles may degrade the uncouplers; (8) Alternatively, cytoplasmic enzymes or chemicals may bind or sequester the protons. The outflow of acidic liquids and other pollutants from mines is often catalysed by acid-loving microorganisms; these are the acidophiles in acid mine drainage. Acidophiles are not just present in exotic environments such as Yellowstone National Park or deep-sea hydrothermal vents.
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