In early 2019, a full 19 months after the treatment was administered, "the acute lymphoblastic leukemia was in complete remission and donor cells carrying the ablated CCR93 persisted," the scientists said in the paper.
|
|
Regenerative ablative armor is powered armor that can restore the ablated material.
|
|
Even though the fecundity of the ablated females may not differ significantly, the hatch rates of ablated females was found to be markedly less (37.8% to 58.1%) than that of unablated females (69.2%). It is also found that wild females are more fecund per unit weight than ablated females. However quantitatively the number of spawns, eggs and nauplii produced by ablated females is ten, eight and six times respectively that of unablated females. The size of females used for broodstock and spawning should preferably be above be and males above , as they mature at approximately and respectively.
|
|
A temperature range of and salinity of 30‰–35‰ is ideal for spawning. Although hatcheries in the developing countries still depend on wild seed, maturation can be induced by eyestalk ablation technique where eyestalks of females are unilaterally ablated to stimulate endocrine activity. The ablated females spawn after 4 days, with a peak observed at days 5–6. However it is expensive to raise spawners in captivity and ablated shrimps result in less hardy fry with low survival rate.
|
|
It is safe and about 75% effective. Symptomatic improvement is sustained for two plus years. Need for additional treatment varies from 16-20% and is largely dependent on the amount of fibroid that can be safely ablated; the higher the ablated volume, the lower the re- treatment rate. There are currently no randomized trial between MRgFUS and UAE.
|
|
Laser ablation is used in science to destroy nerves and other tissues to study their function. For example, a species of pond snail, Helisoma trivolvis, can have their sensory neurons laser ablated off when the snail is still an embryo to prevent use of those nerves. Another example is the trochophore larva of Platynereis dumerilii, where the larval eye was ablated and the larvae was not phototactic, anymore. However phototaxis in the nectochaete larva of Platynereis dumerilii is not mediated by the larval eyes, because the larva is still phototactic, even if the larval eyes are ablated.
|
|
Immediately following ablatio (at 5 hours), there were no noticeable differences in synaptic structure or functionality. Motor-end plate potentials were unaltered in the pre-ablated and the 5 hour ablated models, showing that PSCs are not essential for short-term maintenance of the NMJ. Approximately 13% of ablated NMJ were observed to be retracted partially or entirely one week after ablation and there was a 50% decrease in end plate potential frequency, meaning the NMJs were firing approximately half as often! This same ablation model cannot be performed in mammals, as the antibody mAB sA12 used in the frog model does not ablate mammalian PSCs.
|
|
Moreover, it may also serve as a barrier that prevents direct traumatic contact with the corneal stroma and hence it is highly involved in stromal wound healing and the associated restoration of anterior corneal transparency at the morphological level. Part of the Bowman's membrane is ablated by the photorefractive keratectomy refractive surgery (commonly known as PRK). As the layer is non-generative, the section of the membrane ablated in the procedure is lost forever.
|
|
Physics and Chemistry in Space (R. Schwenn and E. Marsch eds.). Springer-Verlag. pp. 204-275 The ablated material, called meteoric smoke, is thought to serve as condensation nuclei for noctilucent clouds.
|
|
Hepatosplenomegaly may also be observed. The symptoms and signs resolve if the renal cell carcinoma (or another associated tumor) is successfully ablated. It is due to release of IL-6 from cancerous cell.
|
|
To test their role in guidance, scientists (Sato and colleagues) ablated lot cells with a toxin called 6-OHDA. As a result, LOT axons were stalled in the areas where lot cells were destroyed, which confirmed lot cells as guidepost cells.
|
|
RFA, or rhizotomy, is sometimes used to treat severe chronic pain in the lower (lumbar) back, where radio frequency waves are used to produce heat on specifically identified nerves surrounding the facet joints on either side of the lumbar spine. By generating heat around the nerve, the nerve gets ablated thus destroying its ability to transmit signals to the brain. The nerves to be ablated are identified through injections of local anesthesia (such as lidocaine) prior to the RFA procedure. If the local anesthesia injections provide temporary pain relief, then RFA is performed on the nerve(s) that responded well to the injections.
|
|
Although MyoD marks myoblast commitment, muscle development is not dramatically ablated in mouse mutants lacking the MyoD gene. This is likely due to functional redundancy from Myf5 and/or Mrf4. Nevertheless, the combination of MyoD and Myf5 is vital to the success of myogenesis.
|
|
However, in contrast to these two endogenous pyrogens, the fever induced by MIP-1 is not inhibited by the cyclooxygenase inhibitor ibuprofen and CCL3 may participate in the febrile response that is not mediated through prostaglandin synthesis and clinically cannot be ablated by cyclooxygenase.
|
|
LA‐(MC)‐ICP‐MS Trends in 2006 and 2007 with Particular Emphasis on Measurement Uncertainties. Geostandards and Geoanalytical Research, 32(4), 469–488. The mineral sample surface is sputtered by a laser inside a sample cell. The ablated particles are collected and incorporated into a carrier gas.
|
|
In the absence of Tyk2, a cytoplasmic IFNAR1 motif is phosphorylated, inducing receptor internalization. IFNAR1 then localizes to the perinuclear endosomal compartment and is degraded. Tyk2 null cells retain some responsiveness to IFNβ. However, responsiveness to IFNα is ablated, likely due to the reduced IFNAR1 membrane expression.
|
|
Molecular chromium(II) hydrides with the formulae and have been isolated in solid gas matrices. The molecular hydrides are very unstable toward thermal decomposition. CrH2 is the major primary product in the reaction of laser-ablated chromium with molecular hydrogen. Dihydridochromium is the most hydrogenated, groundstate classical molecular hydride of chromium.
|
|
The metal plasma arc produces tremendous amounts of light energy from far infrared to ultraviolet. Surfaces of nearby objects, including people, absorb this energy and are instantly heated to vaporizing temperatures. The effects of this can be seen on adjacent walls and equipment - they are often ablated and eroded from the radiant effects.
|
|
But if the adult eyes are ablated, then the nectochaete is not phototactic anymore and thus phototaxis in the nectochaete larva is mediated by the adult eyes. Laser ablation can also be used to destroy individual cells during embryogenesis of an organism, like Platynereis dumerilii, to study the effect of missing cells during development.
|
|
It has been detected as a transient species in the gas phase;The Chemistry of Aluminium, Gallium, Indium and Thallium, Anthony John Downs, 1993, , also at low temperature (3.5 K) following the reaction of laser ablated gallium atoms and dihydrogen, and more recently in an argon matrix doped with vapour over solid digallane, Ga2H6.
|
|
Uranium(IV) hydride is a chemical compound with the chemical formula UH4, a metal hydride composed of uranium and hydrogen. In 1997, Souter et al. reported the production of UH4 reacting laser ablated uranium atoms with dihydrogen and capturing the product on solid argon. The assignment of the structure was made using infrared spectroscopic evidence supported by DFT calculations.
|
|
Fig.1 - Effects of glial ablation on follower neurons in Drosophila. 1 - Wild type situation; 2 - Ablated embryoWhen there is an absence of glia, follower axons misroute. Arrow indicates deviation. Adapted from Hidalgo A. and Booth GE. (2000) There are reciprocal interactions between neurons and glia during axon guidance, which restricts glial movement and axonal trajectories.
|
|
The outer layer of the pellet is ablated, providing a reaction force that compresses the central 10% of the fuel by a factor of 10 or 20 to 103 or times solid density. These microplasmas disperse in a time measured in nanoseconds. For a fusion power reactor, a repetition rate of several per second will be needed.
|
|
In Wasmannia auropunctata, queens produce more queens through parthenogenesis. Sterile workers usually are produced from eggs fertilized by males. In some of the eggs fertilized by males, however, the fertilization can cause the female genetic material to be ablated from the zygote. In this way, males pass on only their genes to become fertile male offspring.
|
|
By utilizing transplantation and ablation in the chick embryo stage, the neural tube and the neural crest cells of the chick were ablated, and replaced with the same parts from a quail. Once hatched, the quail feathers were visibly apparent around the wing area, whereas the rest of the chick’s body was made of its own chicken cells.
|
|
If any of the previously mentioned factors' functions are ablated, the default photoreceptor is a S cone. These events take place at different time periods for different species and include a complex pattern of activities that bring about a spectrum of phenotypes. If these regulatory networks are disrupted, retinitis pigmentosa, macular degeneration or other visual deficits may result.
|
|
Advantages include less bleeding, shorter surgery time, less risk of infection, and less post-op swelling. Applications include gynecology, dentistry, oral and maxillofacial surgery, and many others. The CO2 laser at the 9.25–9.6 μm wavelength is sometimes used in dentistry for hard-tissue ablation. The hard-tissue is ablated at temperatures as high as 5,000 °C, producing bright thermal radiation.
|
|
Ivan Bekey, "Project Orion: Orbital Debris Removal Using Ground-Based Sensors and Lasers.", Second European Conference on Space Debris, 1997, ESA-SP 393, p. 699. The laser would operate in pulsed mode to avoid self-shielding of the target by the ablated plasma. The power levels of lasers in this concept are well below the power levels in concepts for more rapidly effective anti- satellite weapons.
|
|
In 1984, he was commissioned to design a tapestry based on the painting Untitled (Shoalhaven Landscape) for the Great Hall at the new Parliament House in Canberra. The work is one of the world's largest tapestries. Yet Boyd could not find the strength to fight for the retention of the lower rectangle ablated by the building consultants. This tapestry was produced in the Victorian Tapestry Workshop, Melbourne.
|
|
First, the sample is mixed with a suitable matrix material and applied to a metal plate. Second, a pulsed laser irradiates the sample, triggering ablation and desorption of the sample and matrix material. Finally, the analyte molecules are ionized by being protonated or deprotonated in the hot plume of ablated gases, and then they can be accelerated into whichever mass spectrometer is used to analyse them.
|
|
The fuel capsule wall is synthesized using light elements ( like plastic, beryllium, or high density carbon, i.e. diamond) . The outer portion of fuel capsule explodes outward when ablated by the x-rays produced by the hohlraum wall upon irradiation by lasers. Due to Newton's third law, the inner portion the fuel capsule implodes, causing the D-T fuel to be supercompressed activating fusion reaction.
|
|
Increasing knowledge of the genetic basis of these diseases has linked proteins to the function of the synapse. Age-related cochlear synaptic and neural degeneration has also been demonstrated in mice. Molecules such as FMRP1 act as translational repressor thus when ablated such as in FXS result in varying degrees of cellular and behavioural abnormalities. Additional molecules thought to be involved include SynGAP and SHANK1.
|
|
Surgical removal of the adenoid is a procedure called adenoidectomy. Adenoid infection may cause symptoms such as excessive mucus production, which can be treated by its removal. Studies have shown that adenoid regrowth occurs in as many as 19% of the cases after removal. Carried out through the mouth under a general anaesthetic (or less commonly a topical), adenoidectomy involves the adenoid being curetted, cauterized, lasered, or otherwise ablated.
|
|
There is some low- quality evidence suggesting that mometasone may lead to symptomatic improvement in children with adenoid hypertrophy. Surgical removal of the adenoids is a procedure called adenoidectomy. Carried out through the mouth under a general anaesthetic, adenoidectomy involves the adenoids being curetted, cauterised, lasered, or otherwise ablated. Adenoidectomy is most often performed because of nasal obstruction, but is also performed to reduce middle ear infections and fluid (otitis media).
|
|
When the notochord is ablated during somitogenesis in the chick embryo, the proper number of somites forms, but the segmentation clock is delayed for the posterior two thirds of the somites. The anterior somites are not affected. In one study, this phenotype was mimicked by Shh inhibitors, and timely somite formation was rescued by exogenous Shh protein, showing that the missing signal produced by the notochord is mediated by Shh.
|
|
Asteroids vary greatly in their composition and shape. An asteroid's composition can range from entirely metallic, to entirely rocky, to a mix of rock and metals. The composition must be taken into account since each material behaves differently when ablated. Initial trials at the University of Strathclyde have shown that laser ablation could be more effective on dense metallic asteroids, because of the shape made by the ejecting material.
|
|
The design temperature of the shockwave, , emits ultraviolet light. Most materials and elements are opaque to ultraviolet especially at the pressures the plate experiences. This prevents the plate from melting or ablating. One issue that remained unresolved at the conclusion of the project was whether or not the turbulence created by the combination of the propellant and ablated pusher plate would dramatically increase the total ablation of the pusher plate.
|
|
In Drosophila, certain lateral neurons (LNs) have been shown to be important for circadian rhythms, including dorsal (LNd) and ventral (LNV) neurons. LNV neurons express PDF (pigment dispersion factor), which was initially hypothesized to be a clock output signal. Mutants for the pdf neuropeptide gene (pdf01) as well as flies selectively ablated for LNV produced similar behavioral responses. Both entrained to external light cues, but were largely arrhythmic in constant conditions.
|
|
Secondary processes involve ion- molecule reactions to form analyte ions. In the lucky survivor model, positive ions can be formed from highly charged clusters produced during break-up of the matrix- and analyte-containing solid. The lucky survivor model (cluster ionization mechanism) postulates that analyte molecules are incorporated in the matrix maintaining the charge state from solution. Ion formation occurs through charge separation upon fragmentation of laser ablated clusters.
|
|
Schematic of LSII Due to recent innovations to the laser spray technique, a new method of laser ablation using the spray method has surfaced. Laserspray inlet ionization (LSII) involves a matrix/analyte sample at atmospheric pressure being ablated, and the ionization process will take place in an ion transfer capillary tube located in the mass spectrometer inlet. The LSII method is also known as laserspray ionization vacuum (LSIV).
|
|
BMAL1 KO is not embryonically lethal and mice with BMAL1 ablated in adulthood do not express the symptoms of BMAL1 KO mice. BMAL1 binding is regulated in a tissue-specific manner by numerous factors including non-circadian ones. Following, tissue- specific KOs cause unique effects. BMAL1 has been shown to be important in bone metabolism as osteoblast BMAL1 KO mice have lower bone mass than their wild type counterparts.
|
|
Information sign at the nature trail The topmost Jurassic layer is called the White Jurassic due to its light colour. These layers can be up to 400 m thick in the Franconian Jura, but at Hesselberg they are mostly ablated; only 85 m is left. The rocks of the Malm are partly sediments and partly formed from reefs of ancient sea sponges. This rock is widely distributed on the main peak.
|
|
CTAB has been shown to have potential use as an apoptosis-promoting anticancer agent for head and neck cancer (HNC). In vitro, CTAB interacted additively with γ radiation and cisplatin, two standard HNC therapeutic agents. CTAB exhibited anticancer cytotoxicity against several HNC cell lines with minimal effects on normal fibroblasts, a selectivity that exploits cancer-specific metabolic aberrations. In vivo, CTAB ablated tumor-forming capacity of FaDu cells and delayed growth of established tumors.
|
|
Individuals with thyroid storm tend to have increased levels of free thyroid hormone, although total thyroid hormone levels may not be much higher than in uncomplicated hyperthyroidism. The rise in the availability of free thyroid hormone may be the result of manipulating the thyroid gland. In the setting of an individual receiving radioactive iodine therapy, free thyroid hormone levels may acutely increase due to the release of hormone from ablated thyroid tissue.
|
|
The effect is caused by the pyrophoric oxidation of the ablated metal particles. In this way, the Kopp–Etchells effect is similar to the sparks made by a grinder, which are also due to pyrophoricity. Abrasion strips made of titanium produce the brightest sparks, and the intensity increases with the size and concentration of sand grains in the air. Sand particles are more likely to hit the rotor when the rotorcraft is near the ground.
|
|
This huge building was covered by a pond and creek in the east as well as the south and by ringwalls on the north side. The massive, 1823 ablated watchtower at the northeast corner of the castle gave a wide view into the valley of Waldershof. The “Markt Waldershof” was pulled into the industrial age in 1907 with the construction of the Haviland porcelain factory. At times, this important industry employed over 1,000 workers.
|
|
The moraine was highly saturated and was subject to water seepage and landslides. Three fountains were built to dispose of the water and were used to supply Bietigheim station. Some animal remains ablated by Ice Age glaciation was found in the excavated earth. The most complex structure in the stretch was the Neckar Viaduct at Marbach, which was built as a five-span steel truss bridge with a total length of 345 m.
|
|
According to game theory, zebrafish who are positioned lateral and ventral to the predator are more likely to survive, rather than any alternate strategy. Finally, the faster (cm/s) the predator is moving, the faster downward the fish will move to escape predation. In vertebrates, the avoidance behaviour appears to be processed in the telencephalon. This has been shown repeatedly in goldfish, as individuals with ablated telencephalons were significantly impaired in acquiring avoidance behaviour.
|
|
Finally, laser ablation can be used to transfer momentum to a surface, since the ablated material applies a pulse of high pressure to the surface underneath it as it expands. The effect is similar to hitting the surface with a hammer. This process is used in industry to work-harden metal surfaces, and is one damage mechanism for a laser weapon. It is also the basis of pulsed laser propulsion for spacecraft.
|
|
Fly lines with ablated PDF neurons were created using Gal4-UAS-regulated transgenes and crossing two fly lines: UAS- rpr control group or UAS-hid. Ablation did not affect the flies' ability to entrain to LD cycles, but their evening locomotor phases showed a 0.5 hour advance. This indicates the rpr and hid ablation individuals that were persistently rhythmic in DD showed shorter period length. In addition, utilizing time-series immunostainings, Lin et al.
|
|
Mice models have also been used to test whether the lack of orexin neurons is correlated with narcolepsy. Mice whose orexin neurons have been ablated have shown sleep fragmentation, SOREMPs, and obesity. Rat models have been used to demonstrate the association between orexin deficiency and narcoleptic symptoms. Rats who lost the majority of their orexinergic neurons exhibited multiple SOREMPs as well as less wakefulness during nocturnal hours, shortened REM latency, and brief periods of cataplexy.
|
|
Research by Glenn Edwards and colleagues at Vanderbilt University's FEL Center in 1994 found that soft tissues including skin, cornea, and brain tissue could be cut, or ablated, using infrared FEL wavelengths around 6.45 micrometres with minimal collateral damage to adjacent tissue. This led to surgeries on humans, the first ever using a free-electron laser. Starting in 1999, Copeland and Konrad performed three surgeries in which they resected meningioma brain tumors.Glenn S. Edwards et al.
|
|
While at the University of Virginia, Foster and Menaker performed experiments where the suprachiasmatic nucleus (SCN) was tested by neural transplantation of donor's SCN to a recipient with an ablated SCN. In the experiment, the donor was a mutant strain of hamster with a shortened circadian period. The recipient was a wild-type hamster. Transplantation was done the other way around as well, with wild-type hamster as the donor and mutant strain hamster as the recipient.
|
|
Recently, some researchers reported successful results with genetic ablation. In particular, genetic ablation is potentially a much more efficient method of removing unwanted cells, such as tumor cells, because large numbers of animals lacking specific cells could be generated. Genetically ablated lines can be maintained for a prolonged period of time and shared within the research community. Researchers at Columbia University report of reconstituted caspases combined from C. elegans and humans, which maintain a high degree of target specificity.
|
|
Localised disease (carcinoma-in-situ) and the precursor condition, anal intraepithelial neoplasia (anal dysplasia or AIN) can be ablated with minimally invasive methods such as Infrared Photocoagulation. Previously, anal cancer was treated with surgery, and in early-stage disease (i.e., localised cancer of the anus without metastasis to the inguinal lymph nodes), surgery is often curative. The difficulty with surgery has been the necessity of removing the internal and external anal sphincter, with concomitant fecal incontinence.
|
|
The laser is fired at the matrix crystals in the dried-droplet spot. The matrix absorbs the laser energy and it is thought that primarily the matrix is desorbed and ionized (by addition of a proton) by this event. The hot plume produced during ablation contains many species: neutral and ionized matrix molecules, protonated and deprotonated matrix molecules, matrix clusters and nanodroplets. Ablated species may participate in the ionization of analyte, though the mechanism of MALDI is still debated.
|
|
It can be done with a local anesthetic on an outpatient basis.Transurethral needle ablation (TUNA) Why it's done - Mayo Clinic It takes about an hour to perform the procedure.Transurethral needle ablation (TUNA) What you can expect - Mayo Clinic It takes about 30 days for the ablated prostate tissue to resorb.Transurethral needle ablation (TUNA) Results - Mayo Clinic Patients should have an annual rectal prostate exam for their doctor to feel the prostate health with a lubricated gloved finger.
|
|
There are two possible mechanisms for stem cell renewal, symmetrical GSC division or de-differentiation of cystoblasts. Normally, GSCs will divide asymmetrically to produce one daughter cystoblast, but it has been proposed that symmetrical division could result in the two daughter cells remaining GSCs. If GSCs are ablated to create an empty niche and the cap cells are still present and sending maintenance signals, differentiated cystoblasts can be recruited to the niche and de-differentiate into functional GSCs.
|
|
Sterile workers usually are produced from eggs fertilized by males. In some of the eggs fertilized by males, however, the fertilization can cause the female genetic material to be ablated from the zygote. In this way, males pass on only their genes to become fertile male offspring. This is the first recognized example of an animal species where both females and males can reproduce clonally resulting in a complete separation of male and female gene pools.
|
|
The wavefront map of the eye may be transferred to a Lasik system and enable the surgeon to treat the aberration. Perfect alignment of the treatment and the pupil on which the Wavefront is measured is required, which is usually achieved through iris feature detection. An efficient eye tracking system and small spot size laser is necessary for treatment . Wavefront customization of ablation increases the depth of ablation because additional corneal tissue must be ablated to compensate for the high order aberrations.
|
|
Direct analysis in real time ambient ionization ion source In ambient ionization, ions are formed outside the mass spectrometer without sample preparation or separation. Ions can be formed by extraction into charged electrospray droplets, thermally desorbed and ionized by chemical ionization, or laser desorbed or ablated and post-ionized before they enter the mass spectrometer. Solid-liquid extraction based ambient ionization uses a charged spray to create a liquid film on the sample surface. Molecules on the surface are extracted into the solvent.
|
|
Diagram of ambient ionization in mass spectrometry indicating desorption/extraction (spray, heat, laser), optional post-ionization (electrospray, chemical ionization, plasma), ion formation, and entry into the vacuum of the mass spectrometer. Ambient ionization is a form of ionization in which ions are formed in an ion source outside the mass spectrometer without sample preparation or separation. Ions can be formed by extraction into charged electrospray droplets, thermally desorbed and ionized by chemical ionization, or laser desorbed or ablated and post-ionized before they enter the mass spectrometer.
|
|
Similar to these cells, CAR cells have correlated with reduced HSCs and LT-HSC activity when ablated. One difference between these cell types, despite the similarity in function, is that CAR cells may be found in both endosteal and perivascular niches, while nestin-positive MSCs are found exclusively in the perivascular niche. Finally, both ECs and adipocytes have been suggested to influence HSC activity in the bone marrow. Studies using antibody-mediated disruption of the VEGF receptors on ECs correlated with poor engraftment of donor cells.
|
|
A recent development in live-attenuated HSV vaccine design is the production of replicative vaccines that are ablated for nervous system infection. These vaccines infect the respiratory mucosa where their replication and localized spread provoke a robust immune response. The safety of these vaccines is based on their inability to invade the nervous system and establish life-long latent infections, as opposed to a general attenuation. Unlike other live-attenuated designs, these vaccines are cleared from the body once the immune response from vaccination has matured.
|
|
The eyestalks of female shrimps are often removed (ablated) to improve reproduction Eyestalk ablation is the removal of one (unilateral) or both (bilateral) eyestalks from a crustacean. It is routinely practiced on female shrimps (or prawns) in almost every marine shrimp maturation or reproduction facility in the world, both research and commercial. The aim of ablation under these circumstances is to stimulate the female shrimp to develop mature ovaries and spawn. Most captive conditions for shrimp cause inhibitions in females that prevent them from developing mature ovaries.
|
|
The chemotherapy or irradiation given immediately prior to a transplant is called the conditioning regimen, the purpose of which is to help eradicate the patient's disease prior to the infusion of HSCs and to suppress immune reactions. The bone marrow can be ablated (destroyed) with dose-levels that cause minimal injury to other tissues. In allogeneic transplants, a combination of cyclophosphamide with total body irradiation is conventionally employed. This treatment also has an immunosuppressive effect that prevents rejection of the HSCs by the recipient's immune system.
|
|
An Electrospray ionization (ESI) source is located above the sample for post-ablation ionization. The jet of ablated material is intersected and ionized by a spray plume from the ESI source located above the sample. The ionized molecules are then swept into the mass spectrometer for analysis. Because an ESI source is used for ionization, the LAESI mass spectra are similar to traditional ESI spectra, which can exhibit multiply charged analyte peaks, and extend the effective mass range of detection to biomolecules >100,000 Da in size.
|
|
Lava flows emanate from cones and make up the present-day surface of the volcano. Mount Morning is almost entirely covered with snow and ice except where it is ablated by southerly winds. Outcrops of volcanic rocks are found at the north-northeastern Riviera Ridge and northeastern Hurricane Ridge on the northern flank, Mason Spur on the southern flank and on Helms Bluff on the eastern flank. Gandalf Ridge is a promontory at the foot of Hurricane Ridge, and Pinnacle Valley is located on the Riviera Ridge.
|
|
Time of Flight Mass Spectrometer Using an Ion Reflector, R. Frey and E. Schlag, 1986 As earlier as 1985, Frey et al. reported on the gridless reflector that demonstrated mass resolution over 10,000 while mass analyzing the laser-ablated plumes that exhibited 3.3% kinetic energy spread at the exit of the ion source. In the 1980s, there were suggested several approaches to a design of gridless reflectrons, mainly aimed at finding the middle ground between higher transmission (i.e., directing a significant per cent of exiting ions toward the ion detector) and target mass resolution.
|
|
Trihydridoboron, also known as borane or borine, is an unstable and highly reactive molecule with the chemical formula . The preparation of borane carbonyl, BH3(CO), played an important role in exploring the chemistry of boranes, as it indicated the likely existence of the borane molecule. However, the molecular species BH3 is a very strong Lewis acid. Consequently it is highly reactive and can only be observed directly as a continuously produced, transitory, product in a flow system or from the reaction of laser ablated atomic boron with hydrogen.
|
|
A second, broader clinical study at ten centers independently confirmed the findings of the first study with a success rate of 80.5% where FIRM was used. The first and second set of trials reported success after the patients were followed for one year. At the beginning of 2014, three-year results showed a success rate of 78% compared to the traditional PVI success rate of 39%. Other published studies have shown that rotors are located in both atria of the heart and in locations that are not targeted and ablated in traditional procedures.
|
|
Thalamotomy (; ) is a surgical procedure in which an opening is made into the thalamus to improve the overall brain function in patients. First introduced in the 1950s, it is primarily effective for tremors such as those associated with Parkinson's disease, where a selected portion of the thalamus is surgically destroyed (ablated). Neurosurgeons use specialized equipment to precisely locate an area of the thalamus, usually choosing to work on only one side (the side opposite that of the worst tremors). Bilateral procedures are poorly tolerated because of increased complications and risk, including vision and speech problems.
|
|
Hephaestin has not yet been linked to a human disease. However, when the protein was ablated in murine models, both intestine-specific and whole-body hephaestin knockout (KO) strains exhibited similarly severe accumulation of iron in the duodenal enterocytes and suffered from microcytic, hypochromic anemia, indicative of systemic iron deficiency. The shared phenotype between the two strains suggests that intestinal hephaestin plays an important role in maintaining whole-body iron homeostasis. However, since both strains were viable, it is likely that hephaestin is not essential and other compensatory mechanisms exist to keep these mice alive.
|
|
DNA methylation's critical nature to corticogenesis has been shown through knockout experiments in mice. When DNMT3b and DNMT1 were ablated separately in mouse embryos they died due to impairment of neural tube development. DNMT3a silencing did not cause embryonic lethality, but did result in a severe detriment in postnatal neurogenesis. This is largely due to the timing in which these epigenetic mechanisms are active. DNMT3b is expressed in early neural progenitor cells and decrease as neural development proceeds and DNMT3a is barely detectable up until embryonic day 10 (E.10).
|
|
Cajal-Retzius cells are the first cells to cover the cortical sheet and hippocampal primordium, and regulate cortical lamination by Reelin. In order to make connections with GABAergic neurons in different regions of the hippocampus (stratum oriens, stratum radiatum, and inner molecular layer), pioneer entorhinal neurons make synaptic contacts with Cajal-Retzius cells. To test their role in guidance, scientists (Del Rio and colleagues) ablated Cajal-Retzius cells with 6-OHDA. As a result, entorhinal axons did not grow in the hippocampus and ruled Cajal-Retzuis cells as guidepost cells.
|
|
Renal sympathetic denervation (RSDN), is a minimally invasive, endovascular catheter based procedure using radiofrequency ablation or ultrasound ablation aimed at treating resistant hypertension (high blood pressure not controlled by medication). Nerves in the wall of the renal artery are ablated by applying radiofrequency pulses or ultrasound to the renal arteries. This causes reduction of sympathetic afferent and efferent activity to the kidney and blood pressure can be decreased. Early data from international clinical trials without sham controls was promising - demonstrating large blood pressure reductions in patients with treatment-resistant hypertension.
|
|
The wand consists of a base electrode and an active electrode, which have ceramic and flowing saline between them. The radio frequency current that is produced by the generator travels through the saline, breaking the molecular bonds and forming ions. This creates a plasma field around the electrodes, which is used for removing soft tissue. There should not be any smoke produced while the coblation wand is being used during the operation; if this occurs, it is a sign that ablated tissue has entered the coblation wand's electrode area.
|
|
Exposure to antimatter is the only known method for destroying a General Products hull until the 2007 novel Fleet of Worlds. In the story Flatlander, a GP Hull is exposed to a constant stream of diffuse antimatter during a visit to a star system with some exotic qualities. Whereas a conventional hull made of metal, for example, would simply have ablated under these conditions, the General Products hull instead simply unravelled. This was due to the fact that a GP Hull essentially consisted of a single incredibly large, highly complex molecule.
|
|
For low detection limits, interfering species and high precision, the counting time can increase substantially. The rapid scanning, large dynamic range and large mass range is ideally suited to measuring multiple unknown concentrations and isotope ratios in samples that have had minimal preparation (an advantage over TIMS), for example seawater, urine, and digested whole rock samples. It also lends well to laser ablated rock samples, where the scanning rate is so quick that a real time plot of any number of isotopes is possible. This also allows easy spatial mapping of mineral grains.
|
|
Functional changes to the heart becomes apparent well before structural changes are observed in the phenotype of ablated chicks. This is due to the embryo compromising morphological changes to the heart to maintain cardiac functioning via vasodilation. Despite an increase in embryonic stroke volume and cardiac output, this compensation of decreased contraction results in misalignment of the development vessels due to incomplete looping of the cardiac tube. In an adult heart, myocardium contraction occurs via excitation-contraction coupling whereby cellular depolarisation occurs and allows an influx of calcium via voltage-gated calcium channels.
|
|
These workers used positional cloning to prove that mice that could not respond to LPS had mutations that abolished the function of TLR4. This identified TLR4 as one of the key components of the receptor for LPS. The history of Toll-like receptors In turn, the other TLR genes were ablated in mice by gene targeting, largely in the laboratory of Shizuo Akira and colleagues. Each TLR is now believed to detect a discrete collection of molecules – some of microbial origin, and some products of cell damage – and to signal the presence of infections.
|
|
The external detector is typically a low-uranium mica flake, but plastics such as CR-39 have also been used. The resulting induced fission of the uranium-235 in the sample creates induced tracks in the overlying external detector, which are later revealed by chemical etching. The ratio of spontaneous to induced tracks is proportional to the age. Another method of determining uranium concentration is through LA-ICPMS, a technique where the crystal is hit with a laser beam and ablated, and then the material is passed through a mass spectrometer.
|
|
A common technique for creating a nanowire is vapor-liquid-solid method (VLS), which was first reported by Wagner and Ellis in 1964 for silicon whiskers with diameters ranging from hundreds of nm to hundreds of µm. This process can produce high-quality crystalline nanowires of many semiconductor materials, for example, VLS–grown single crystalline silicon nanowires (SiNWs) with smooth surfaces could have excellent properties, such as ultra-large elasticity. This method uses a source material from either laser ablated particles or a feed gas such as silane. VLS synthesis requires a catalyst.
|
|
The depth over which the laser energy is absorbed, and thus the amount of material removed by a single laser pulse, depends on the material's optical properties and the laser wavelength and pulse length. The total mass ablated from the target per laser pulse is usually referred to as ablation rate. Such features of laser radiation as laser beam scanning velocity and the covering of scanning lines can significantly influence the ablation process. Laser pulses can vary over a very wide range of duration (milliseconds to femtoseconds) and fluxes, and can be precisely controlled.
|
|
The suitability of RFA for a particular tumor depends on multiple factors. RFA can usually be administered as an outpatient procedure, though may at times require a brief hospital stay. RFA may be combined with locally delivered chemotherapy to treat hepatocellular carcinoma (primary liver cancer). A method currently in phase III trials uses the low-level heat (hyperthermia) created by the RFA probe to trigger release of concentrated chemotherapeutic drugs from heat-sensitive liposomes in the margins around the ablated tissue as a treatment for Hepatocellular carcinoma (HCC).
|
|
However, it has been found that large LNv working with other circadian neurons is sufficient to rescue the morning anticipation behavior and startle response in s-LNv-ablated flies. Thus, PDF's role in setting the free-running rhythm and the timing of light-dark cycles comes from both types of lateral ventral neurons. Further evidence of distinct E and M peaks in Drosophila was provided by Grima et al. This work confirmed that the small lateral ventral neurons, which express PDF, are necessary for the morning peak in Drosophila circadian rhythms.
|
|
Their dendrites branch out radiantly from a soma, and there is a significant dendritic overlap. Optical measurements of Ca2+ concentration showed that they respond strongly to the centrifugal motion (the outward motion from the soma to the dendrites), while they don't respond well to the centripetal motion (the inward motion from the dendritic tips to the soma). When the starburst cells were ablated with toxins, direction selectivity was eliminated. Moreover, their release of neurotransmitters itself, specifically calcium ions, reflect direction selectivity, which may be presumably attributed to the synaptic pattern.
|
|
A Coulomb explosion is a "cold" alternative to the dominant laser etching technique of thermal ablation, which depends on local heating, melting, and vaporization of molecules and atoms using less-intense beams. Pulse brevity down only to the nanosecond regime is sufficient to localize thermal ablation - before the heat is conducted far, the energy input (pulse) has ended. Nevertheless, thermally ablated materials may seal pores important in catalysis or battery operation, and recrystallize or even burn the substrate, thus changing the physical and chemical properties at the etch site. In contrast, even light foams remain unsealed after ablation by Coulomb explosion.
|
|
The direct use of nuclear explosives, by using the impact of ablated propellant plasma from a nuclear shaped charge acting on the rear pusher plate of a ship, was and continues to be seriously studied as a potential propulsion mechanism. Although likely never achieving orbit due to aerodynamic drag, the first macroscopic object to obtain Earth orbital velocity was a "900kg manhole cover" propelled by the somewhat focused detonation of test shot Pascal-B in August 1957. The use of a subterranean shaft and nuclear device to propel an object to escape velocity has since been termed a "thunder well".
|
|
There is no or only minor damage done to nearby tissues during the coblation procedure because charged particles move between the generated plasma field and the ablated tissue, hence the molecules breakdown without the temperatures rising high. The temperature for coblation tonsillectomy ranged from 60 °C to 70 °C, while other tonsillectomy operation procedures, such as electrosurgery require temperatures ranging from 400 °C to 600 °C, which is much higher. Thus, coblation is considered to be a non-heat focused medical procedure that is much better at causing minimal thermal damage to untargeted tissues near the targeted area.
|
|
A study that compared the lesions of two cerebral deafness patients to an auditory agnosia patient concluded that cerebral deafness is the result of complete de- afferentation of the auditory cortices, whereas in auditory agnosia some thalamo-cortical fibers are spared. In most cases the disorder is transient and the symptoms mitigate into auditory agnosia (although chronic cases were reported). Similarly, a monkey study that ablated both auditory cortices of monkeys reported of deafness that lasted 1 week in all cases, and that was gradually mitigated into auditory agnosia in a period of 3–7 weeks.
|
|
When Notch signaling is disrupted in zebrafish, neighboring cells no longer oscillate synchronously, indicating that Notch signaling is important for keeping neighboring populations of cells synchronous. In addition, some cellular inter-dependency has been displayed in studies concerning the protein Sonic hedgehog (Shh) in somitogenesis. Although expression of Shh pathway proteins has not been reported to oscillate in the pre-somitic mesoderm, they are expressed within the pre-somitic mesoderm during somitogenesis. When the notochord is ablated during somitogenesis in the chick embryo, the proper number of somites forms, but the segmentation clock is delayed for the posterior two-thirds of the somites.
|
|
In some conditions, especially forms of intra-nodal re-entry (the most common type of SVT), also called atrioventricular nodal reentrant tachycardia or AVNRT, ablation can also be accomplished by cryoablation (tissue freezing using a coolant which flows through the catheter) which avoids the risk of complete heart block – a potential complication of radiofrequency ablation in this condition. Recurrence rates with cryoablation are higher, though. Microwave ablation, where tissue is ablated by the microwave energy "cooking" the adjacent tissue, and ultrasonic ablation, creating a heating effect by mechanical vibration, or laser ablation have also been developed but are not in widespread use.
|
|
When a mid-IR laser beam is applied to a target which contains a hydroxide group, the target will absorb energy from this laser beam leading to evaporation of moisture from the targeted area. A small-scale explosion occurs in the target and a small portion of the sample is ablated into the gas phase by a short (5 ns), mid-IR (2,940 nm) laser pulse. The plume expands until it collapses into the sample due to the pressure exerted by the atmosphere. At this point a jet of material is ejected from the sample surface.
|
|
Prolonged spermatogenesis relies on the maintenance of SSCs, however, this maintenance declines with age and leads to infertility. Mice between 12 and 14 months of age show decreased testis weight, reduced spermatogenesis and SSC content. Although stem cells are regarded as having the potential to infinitely replicate in vitro, factors provided by the niche are crucial in vivo. Indeed, serial transplantation of SSCs from male mice of different ages into young mice 3 months of age, whose endogenous spermatogenesis had been ablated, was used to estimate stem cell content given that each stem cell would generate a colony of spermatogenesis.
|
|
Hydrogen gas is ducted through this core, heated, and expelled from a rocket nozzle. A second proposed engine type uses positron annihilation within a solid lead pellet or within compressed xenon gas to produce a cloud of hot gas, which heats a surrounding layer of gaseous hydrogen. Direct heating of the hydrogen by gamma rays was considered impractical, due to the difficulty of compressing enough of it within an engine of reasonable size to absorb the gamma rays. A third proposed engine type uses annihilation gamma rays to heat an ablative sail, with the ablated material providing thrust.
|
|
If an ice sheet were ablated down to bare ground, less light from the sun would be reflected back into space and more would be absorbed by the land. The Greenland Ice Sheet covers 84% of the island and the Antarctic Ice Sheet covers approximately 98% of the continent. Due to the significant thickness of these ice sheets, global warming analysis typically focuses on the loss of ice mass from the ice sheets increasing sea level rise, and not on a reduction in the surface area of the ice sheets. Until recently, ice sheets were viewed as inert components of the carbon cycle and were largely disregarded in global models.
|
|
The establishment of the dorsal-ventral axis during early embryological development has also been extensively studied in C. teleta. It is reported that micromere 2d, a cell that is born when the embryo has 16 cells, has organizing activity which enables it to induce dorsal-ventral polarity within the embryo. Fate map studies have demonstrated that cell 2d gives rise to ectoderm in the larval trunk and pygidium in C. teleta, while descendants of the first quartet micromeres give rise to structures in the larval head. When micromere 2d is laser ablated, 2d derived structures as well as dorsal-ventral organization in the head is lost.
|
|
Ablative propulsion will work in air or vacuum. Specific impulse values from 200 seconds to several thousand seconds are possible by choosing the propellant and laser pulse characteristics. Variations of ablative propulsion include double-pulse propulsion in which one laser pulse ablates material and a second laser pulse further heats the ablated gas, laser micropropulsion in which a small laser on board a spacecraft ablates very small amounts of propellant for attitude control or maneuvering, and space debris removal, in which the laser ablates material from debris particles in low Earth orbit, changing their orbits and causing them to reenter. University of Alabama Huntsville Propulsion Research Center has researched ALP.
|
|
After the initial nervous-muscle interface is formed, there is a striking growth in the number of PSCs at each newly developed NMJ. If, however, there is a lack of PSCs (for example in an ablated model) once the NMJ is formed, there is a lack of further axonal growth or even a retraction of axons can be observed. This is seen in a study on frog NMJs 8 and 12 days after ablation where there was a 44% retraction rate by the 12th day with no PSCs. This retraction shows that PSCs are not essential for the growth of axons, but are essential for the long-term maintenance of NMJs.
|
|
In these procedures, wires are passed from a vein or artery in the leg to the heart to find the abnormal area of tissue that is causing the arrhythmia. The abnormal tissue can be intentionally damaged, or ablated, by heating or freezing to prevent further heart rhythm disturbances. Whilst the majority of arrhythmias can be treated using minimally invasive catheter techniques, some arrhythmias (particularly atrial fibrillation) can also be treated using open or thoracoscopic surgery, either at the time of other cardiac surgery or as a standalone procedure. A cardioversion, whereby an electric shock is used to stun the heart out of an abnormal rhythm, may also be used.
|
|
The third stage is important to determine the quality of the deposited films. The high energetic species ablated from the target are bombarding the substrate surface and may cause damage to the surface by sputtering off atoms from the surface but also by causing defect formation in the deposited film. The sputtered species from the substrate and the particles emitted from the target form a collision region, which serves as a source for condensation of particles. When the condensation rate is high enough, a thermal equilibrium can be reached and the film grows on the substrate surface at the expense of the direct flow of ablation particles and the thermal equilibrium obtained.
|
|
Continuous-wave lasers used a high energy beam that ablated the target area and destroyed surrounding tissue structures as well as tattoo ink. Treatment tended to be painful and cause scarring. Before the development of laser tattoo removal methods, common techniques included dermabrasion, TCA (Trichloroacetic acid, an acid that removes the top layers of skin, reaching as deep as the layer in which the tattoo ink resides), salabrasion (scrubbing the skin with salt), cryosurgery and excision which is sometimes still used along with skin grafts for larger tattoos. Many other methods for removing tattoos have been suggested historically including the injection or application of tannic acid, lemon juice, garlic and pigeon dung.
|
|
While being less common in the past, is rapidly becoming popular has been used as a means of sample introduction, thanks to increased ICP-MS scanning speeds. In this method, a pulsed UV laser is focused on the sample and creates a plume of ablated material which can be swept into the plasma. This allows geochemists to spacially map the isotope composition in cross-sections of rock samples, a tool which is lost if the rock is digested and introduced as a liquid sample. Lasers for this task are built to have highly controllable power outputs and uniform radial power distributions, to produce craters which are flat bottomed and of a chosen diameter and depth.
|
|
If it is found that the wrong tissue is being frozen, the freezing process can quickly be stopped and the tissue return to normal temperature and function in a short time. If after freezing the tissue to −10 °C the desired result is obtained, the tissue can be further cooled to a temperature of −73 °C (-99.4 °F) and it will be permanently ablated. This therapy has further improved the treatment options for people with AVNRT (and other SVTs with pathways close to the AV node), widening the application of curative ablation to young patients with relatively mild but still troublesome symptoms who would not have accepted the risk of requiring a pacemaker.
|
|
R702C NM IIA mice show similar defects in placental formation and mice specifically ablated for NM IIA in the mouse trophoblast- lineage cells demonstrate placental defects similar to mice in which NMHC IIA is genetically replaced by NMHC IIB. There are significant differences in the relative abundance of the three NM II paralogs in various cells and tissues. However, NM IIA appears to be the predominant paralog in both tissues and cells in humans and mice. Mass spectroscopy analysis of the relative abundance of NMHC IIs in mouse tissues and human cell lines shows that NM IIA is predominant, although tissues like the heart vary from cell to cell; myocardial cells contain only NM IIB but NM IIA is more abundant in the non- myocyte cells.
|
|
The inlay is ablated with wavefront guided excimer laser, to correct the refractive errors of the eye, applying a cross linking solution to the inlay and stromal tissue of the cornea, replacing the corneal flap and cross linking the inlay with UV radiation, killing the cellular elements in the inlay and its surrounding cornea, preventing cellular migration in the inlay and its rejection or encapsulation by the host corneal cells. This new procedure is now called “Mesoick” (Meso means Inside, Implant, Crosslinking Keratomileusis (US Patent 9,037,033). This creates an immune privileged cell free space that does not initiate an immune response to an implant. A synthetic, crosslinked organic or polymeric lens can be implanted in the corneal pocket to compensate for the patient's refractive error.
|
|
Laser ablation is used as a sampling method for elemental and isotopic analysis, and replaces traditional laborious procedures generally required for digesting solid samples in acid solutions. Laser ablation sampling is detected by monitoring the photons emitted at the sample surface - a technology referred to as LIBS (Laser Induced Breakdown Spectroscopy) and LAMIS (Laser Ablation Molecular Isotopic Spectrometry), or by transporting the ablated mass particles to a secondary excitation source, like the inductively coupled plasma. Both mass spectroscopy (MS) and optical emission spectroscopy (OES) can be coupled with the ICP. The benefits of laser ablation sampling for chemical analysis include no sample preparation, no waste, minimal sample requirements, no vacuum requirements, rapid sample- analysis turn-around time, spatial (depth and lateral) resolution, and chemical mapping.
|
|
The energy is mostly deposited within about one X-ray optical thickness of the tamper/pusher outer surface, and the temperature of that layer can then be calculated. The velocity at which the surface then expands outwards is calculated and, from a basic Newtonian momentum balance, the velocity at which the rest of the tamper implodes inwards. Applying the more detailed form of those calculations to the Ivy Mike device yields vaporized pusher gas expansion velocity of 290 kilometres per second and an implosion velocity of perhaps 400 km/s if 3/4 of the total tamper/pusher mass is ablated off, the most energy efficient proportion. For the W-80 the gas expansion velocity is roughly 410 km/s and the implosion velocity 570 km/s.
|
|
Radiofrequency ablation (RFA), also called fulguration, is a medical procedure in which part of the electrical conduction system of the heart, tumor or other dysfunctional tissue is ablated using the heat generated from medium frequency alternating current (in the range of 350–500 kHz). RFA is generally conducted in the outpatient setting, using either local anesthetics or conscious sedation anesthesia. When it is delivered via catheter, it is called radiofrequency catheter ablation. Two important advantages of radio frequency current (over previously used low frequency AC or pulses of DC) are that it does not directly stimulate nerves or heart muscle and therefore can often be used without the need for general anesthesia, and that it is very specific for treating the desired tissue without significant collateral damage.
|
|
In terms of domain architecture, all of the enzymes are built upon a common PLC-δ backbone, wherein each family displays similarities, as well as obvious distinctions, that contribute to unique regulatory properties within the cell. Because it is the only family found expressed in lower eukaryotic organisms such as yeast and slime molds, it is considered the prototypical PLC isoform. The other family members more than likely evolved from PLC-δ as their domain architecture and mechanism of activation were expanded. Although a full crystal structure has not been obtained, high-resolution X-ray crystallography has yielded the molecular structure of the N-terminal PH domain complexed with its product IP3, as well as the remainder of the enzyme with the PH domain ablated.
|
|
The combination of the movements of the gantry and of the couch makes possible the computerized planning of the volume of tissue that is going to be irradiated. Devices with a high energy of 6 MeV are the most suitable for the treatment of the brain, due to the depth of the target. The diameter of the energy beam leaving the emission head can be adjusted to the size of the lesion by means of collimators. They may be interchangeable orifices with different diameters, typically varying from 5 to 40 mm in 5 mm steps, or multileaf collimators, which consist of a number of metal leaflets that can be moved dynamically during treatment in order to shape the radiation beam to conform to the mass to be ablated.
|
|
A Holter monitor is an EKG recorded over a 24-hour period, to detect arrhythmias that may happen briefly and unpredictably throughout the day. A more advanced study of the heart's electrical activity can be performed to assess the source of the aberrant heart beats. This can be accomplished in an electrophysiology study, an endovascular procedure that uses a catheter to "listen" to the electrical activity from within the heart, additionally if the source of the arrhythmias is found, often the abnormal cells can be ablated and the arrhythmia can be permanently corrected. ' (TAS) instead uses an electrode inserted through the esophagus to a part where the distance to the posterior wall of the left atrium is only approximately 5–6 mm (remaining constant in people of different age and weight).
|
|
A lineatus uses the shape of the waveform to determine distance by analyzing how much the waveform has changed since it was generated; this amount of change is extremely predictable and regular. The surface waveform has high frequencies near source, and lower frequencies farther away due to the dampening effect of the water surface; the amount of decrease diminishes with distance. A lineatus' possible use of the wavefront's curvature can be excluded since fish are still able to judge the distance of a wave's source with only a single functioning neuromast when all others have been ablated. When presented with single-frequency or upward frequency-modulated waves, fish underestimate the distance of the wave source; this suggests the normal downward FM of capillary waves, which arises almost immediately in wave dispersion, is necessary for A lineatus to judge distance.
|
|
Once fluid flow begins, biomechanical and hemodynamic inputs are applied to the system set up by vasculogenesis, and the active remodelling process can begin. Physical cues such as pressure, velocity, flow patterns, and shear stress are known to act on the vascular network in a number of ways, including branching morphogenesis, enlargement of vessels in high-flow areas, angiogenesis, and the development of vein valves. The mechanotransduction of these physical cues to endothelial and smooth muscle cells in the vascular wall can also trigger the promotion or repression of certain genes which are responsible for vasodilation, cell alignment, and other shear stress-mitigating factors. This relationship between genetics and environment is not clearly understood, but researchers are attempting to clarify it by combining reliable genetic techniques, such as genetically-ablated model organisms and tissues, with new technologies developed to measure and track flow patterns, velocity profiles, and pressure fluctuations in vivo.
|
|
LIBS makes use of optical emission spectrometry and is to this extent very similar to arc/spark emission spectroscopy. LIBS operates by focusing the laser onto a small area at the surface of the specimen; when the laser is discharged it ablates a very small amount of material, in the range of nanograms to picograms, which generates a plasma plume with temperatures in excess of 100,000 K. During data collection, typically after local thermodynamic equilibrium is established, plasma temperatures range from 5,000–20,000 K. At the high temperatures during the early plasma, the ablated material dissociates (breaks down) into excited ionic and atomic species. During this time, the plasma emits a continuum of radiation which does not contain any useful information about the species present, but within a very small timeframe the plasma expands at supersonic velocities and cools. At this point the characteristic atomic emission lines of the elements can be observed.
|
|
Moreover, the C-start can be evoked even with the M-cell ablated, although in this case the latency of the response increases. The most widely accepted model of the M-cell system, or brainstem escape network, is that the M-cell initiates a fixed action pattern to the left or right by activating a spinal motor circuit initially described by J. Diamond and colleagues, but the precise trajectory of the escape is encoded by population activity in the other classes of reticulospinal neurons functioning in parallel to the M-cell. This notion is supported by studies using in vivo calcium imaging in larval zebrafish which show that MiD2cm and MiD3cm are activated along with the M-cell when an offending stimulus is directed towards the head but not the tail, and are correlated with C-starts of a larger initial turn angle. Another component of the escape response is mediated by cranial relay neurons that are activated by the Mauthner cell spike.
|
|