Strong connections, with lots of ion flow, indicated that social experiences were rewarding.
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They led Dr. Gilroy and his team to look into calcium ion flow.
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Conversely, weak connections (those with little ion flow) indicated that social experiences were not triggering a reward.
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Unlike lithium-ion, flow batteries become cheaper as you scale them because the electrical charge comes from external tanks of liquid.
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The results were measured up to an hour after consumption using selected ion flow tube mass spectrometry, a piece of equipment which analyses trace gases and compounds in exhaled breath.
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The surface of the chip is outfitted with 500 gridded tips, built on top of several layers of porous metal that mediate ion flow from a liquid plasma chamber at the base.
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Some other techniques are Secondary electrospray ionization (SESI), Electrospray ionization (ESI), and Selected-ion flow-tube mass spectrometry (SIFT).
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Physical changes in these proteins increase ion flow across the membrane, and can generate an action potential or a graded potential in the sensory neurons.
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The abnormal ion flow results in the activation of biochemical processes (pathways) that lead to increased aldosterone production, causing the hypertension associated with familial hyperaldosteronism type III. The genetic cause of familial hyperaldosteronism type II is unknown.
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The instrument is an extension of the selected ion flow tube, SIFT, technique, which was first described in 1976 by Adams and Smith."The selected ion flow tube (SIFT); A technique for studying ion-neutral reactions" Adams N.G., Smith D.; International Journal of Mass Spectrometry and Ion Physics 21 (1976) pp349-359. It is a fast flow tube/ion swarm method to react positive or negative ions with atoms and molecules under truly thermalised conditions over a wide range of temperatures. It has been used extensively to study ion- molecule reaction kinetics.
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Thorson, Timothy A. Ion Flow and Fusion Reactivity Characterization of a Spherically Convergent Ion Focus. Thesis. Wisconsin Madison, 1996. Madison: University of Wisconsin, 1996. Print. The halo mode occurs in higher pressure tanks, and as the vacuum improves, the device transitions to star mode.
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IPTBO is both a convulsant and a stimulant, essentially causing an overload of chemical signals in the brain and overexciting neurons. Because IPTBO causes unusually large amounts of overexcitation in neurons, GABA is no longer able to stop the buildup of internal charge, and thereby triggers a convulsion. IPTBO additionally acts as a non-competitive GABA antagonist that does not bond to the receptor site for GABA, and instead interferes with chloride ion flow in the physical channel of the receptor, making it an allosteric antagonist. IPTBO disrupts chloride ion flow out of the channel, causing charge buildup and signal disturbance as well as causing an overexcitation in neurons.
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Even so, in terms of "in-out", the direction of chloroplast H ion flow is in the opposite direction compared to oxidative phosphorylation in mitochondria. In addition, in terms of function, the inner chloroplast membrane, which regulates metabolite passage and synthesizes some materials, has no counterpart in the mitochondrion.
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IPTBO (isopropylbicyclophosphate) is a bicyclic phosphate convulsant. It is an extremely potent GABA receptor antagonist that can cause violent convulsions in mice. IPTBO is found among a group of highly toxic bicyclic phosphates. Generally, bicyclic phosphates disrupt chlorine ion flow through GABA receptors, causing CNS overstimulation and lethal convulsions within minutes.
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Voltage-gated ion channel. When the membrane is polarized, the voltage sensing domain of the channel shifts, opening the channel to ion flow (ions represented by yellow circles). Voltage-gated ion channels open and close in response to the electrical potential across the cell membrane. Portions of the channel domain act as voltage sensors.
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The atmospheric potential gradient leads to an ion flow from the positively charged atmosphere to the negatively charged earth surface. Over a flat field on a day with clear skies, the atmospheric potential gradient is approximately 120 V/m. Objects protruding these fields, e.g. flowers and trees, can increase the electric field strength to several kilovolts per meter.
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An arrhythmia can present itself as either bradycardia or tachycardia. Untreated arrhythmias may progress to atrial fibrillation or ventricular fibrillation. Treatment is aimed at normalizing cardiac rhythm by altering ion flow across the membrane. Antiarrhythmic agents can reduce arrhythmia related symptoms such as palpitations or syncope; however, they often have a narrow therapeutic index and can also be proarrhythmic.
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Kaitocephalin acts by inhibiting glutamate receptors. Glutamate is the most abundant neurotransmitter in the vertebrate nervous system and is involved in learning, memory, and neuroplasticity.Masanori Kawasaki et al., "Total Synthesis of (-)-Kaitocephalin", Organic Letters 7 (2005): 4165-4167 It is an excitatory neurotransmitter, so binding of glutamate to its receptors increases ion flow through the postsynaptic membrane.
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Komarov was ordered to re-orient the craft using the ion flow sensors on orbits 15 to 17. The ion sensors failed. Komarov did not have enough time to attempt a manual re-entry until orbit 19. Manual orientation relied on using the equipped Vzor periscope device, but to do this, Komarov had to be able to see the Sun.
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A lithium-ion flow battery is a flow battery that uses a form of lightweight lithium as its charge carrier. The flow battery stores energy separately from its system for discharging. The amount of energy it can store is determined by tank size; its power density is determined by the size of the reaction chamber. Dissolving a material changes its chemical behavior significantly.
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The interplay between opening and inactivation controls the firing pattern of a neuron by changing the rate and amount of ion flow through the channels. Voltage-gated ion channels open upon depolarization of the cell membrane. This creates a current caused by the flow of ions through the channel. Shortly after opening, the channel is blocked by the peptide ball.
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An electro-chemical oxidation process. The organic waste is treated by the generation of highly oxidising species in an electro-chemical cell. The cell is separated into two compartments by a membrane that allows ion flow but prevents bulk mixing of the anolyte and catholyte. In the anolyte compartment a highly reactive species of silver ion attacks organic material ultimately converting it to CO2, H2O and non-toxic inorganic compounds.
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The action potential travels from one location in the cell to another, but ion flow across the membrane occurs only at the nodes of Ranvier. As a result, the action potential signal jumps along the axon, from node to node, rather than propagating smoothly, as they do in axons that lack a myelin sheath. The clustering of voltage-gated sodium and potassium ion channels at the nodes permits this behavior.
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Electrodialysis reversal (EDR) is an electrodialysis reversal water desalination membrane process that has been commercially used since the early 1960s. An electric current migrates dissolved salt ions, including fluorides, nitrates and sulfates, through an electrodialysis stack consisting of alternating layers of cationic and anionic ion exchange membranes. Periodically (3-4 times per hour), the direction of ion flow is reversed by reversing the polarity of the applied electric current.
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A 2006 study found that, while not structurally similar to GABA, picrotoxin prevents ion flow through the chloride channels activated by GABA. It likely acts within the ion channels themselves, rather than at GABA recognition sites. Because it inhibits channels activated by GABA, GABA-enhancing drugs like barbiturates and benzodiazepines can be used as an antidote. Other research suggests that the toxin acts instead as a non-competitive antagonist, or inhibitor, for GABA receptors.
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Prototypical depiction of ionotropic receptor in the case of Ca2+ ion flow Ionotropic receptors, otherwise known as ligand-gated ion channels, are fast acting receptors that mediate neural and physiological function by ion channel flow with ligand-binding. Nicotinic, GABA, and Glutamate receptors are among some of the cell surface receptors regulated by ligand-gated ion channel flow. GABA is the brain's main inhibitory neurotransmitter and glutamate is the brain's main excitatory neurotransmitter.
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Short-term inhibitory synaptic plasticity often occurs because of limited neurotransmitter supply at the synapse, and long-term inhibition can occur through decreased receptor expression in the postsynaptic cell. Short-term complementary synaptic plasticity often occurs because of residual or increased ion flow in either the presynaptic or postsynaptic terminal, while long-term synaptic plasticity can occur through the increased production of AMPA and NMDA glutamate receptors, among others, in the postsynaptic cell.
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Potassium channels play a role in many cellular processes including the maintenance of the action potential, muscle contraction, hormone secretion, osmotic regulation, and ion flow. This gene encodes the K2P4.1 protein, a lipid-gated ion channel that belongs to the superfamily of potassium channel proteins containing two pore-forming P domains. K2P4.1 homodimerizes and functions as an outwardly rectifying channel. It is expressed primarily in neural tissues and is stimulated by membrane stretch and polyunsaturated fatty acids.
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A flowing afterglow is an ion source that is used to create ions in a flow of inert gas, typically helium or argon. Flowing afterglow ion sources usually consist of a dielectric discharge that gases are channeled through to be excited and thus made into plasma. Flowing afterglow ion sources can be coupled with a selected-ion flow- tube for selection of reactant ions. When this ion source is coupled with mass spectrometry it is referred to as flowing afterglow mass spectrometry.
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Ion Flow and Fusion Reactivity, Characterization of a Spherically convergent ion Focus. PhD Thesis, Dr. Timothy A Thorson, Wisconsin-Madison 1996. Designs have been proposed to avoid the problems associated with the cage, by generating the field using a non-neutral cloud. These include a plasma oscillating device,"Stable, thermal equilibrium, large-amplitude, spherical plasma oscillations in electrostatic confinement devices", DC Barnes and Rick Nebel, PHYSICS OF PLASMAS VOLUME 5, NUMBER 7 JULY 1998 a penning trap and the polywell.
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Each outgoing ion generated by an electron allows a number of electrons to be emitted. This number is approximately equal to the square root of the ratio of the ion mass to the electron mass. It can be seen in the below chart what a typical I-V curve looks like for a hollow cathode in electron emission mode. Given a certain keeper geometry (the ring in the figure above that the electrons exit through), ion flow rate, and Vp, the I-V profile can be determined.
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The TRPM8 channel is a homotetramer, composed of four identical subunits with a transmembrane domain with six helices (S1–6). The first four, S1–4, act as the voltage sensor and allow binding of menthol, icilin and similar channel agonists. S5 and S6 and a connecting loop, also part of the structure, make up the pore, a non-selective cation channel which consists of a highly conserved hydrophobic region, A range of diverse components are required for the high level of specificity in responding to result in ion flow to cold and menthol stimuli.
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This results in ion-vapor reactions dominating the majority of the ionization region. As charging ions originate from nano-droplets, and no high energy ions are involved at any point of the ionization process nor the creation of ionizing agents, fragmentation in SESI is remarkably low, and the resulting spectra are very clean. This allows for a very high dynamic range, where low intensity peaks are not affected by more abundant species. Some related techniques are laser ablation electrospray ionization, proton- transfer-reaction mass spectrometry and selected-ion flow-tube mass spectrometry.
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A neurotransmitter can influence the function of a neuron through a remarkable number of mechanisms. In its direct actions in influencing a neuron's electrical excitability, however, a neurotransmitter acts in only one of two ways: excitatory or inhibitory. A neurotransmitter influences trans-membrane ion flow either to increase (excitatory) or to decrease (inhibitory) the probability that the cell with which it comes in contact will produce an action potential. Thus, despite the wide variety of synapses, they all convey messages of only these two types, and they are labeled as such.
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They showed that a rare CACNA1B mutation identified in a three-generation family with a myoclonus dystonia-like syndrome impacts single CaV2.2 channel activity by altering ion flow. In collaborations with colleagues at the Stanley Center of the Broad Institute, the Lipscombe Lab described the electrophysiological consequences of rare missense variations in CACNA1. They also showed that rare de novo variants of CACNA1I linked to schizophrenia impacts membrane trafficking of CaV3.3 with expected alterations in burst firing in thalamic relay neurons. Tool building The Lipscombe’s lab clones are available through Addgene.
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The nAChR is unable to bind ACh when bound to any of the snake venom α-neurotoxins. These α-neurotoxins antagonistically bind tightly and noncovalently to nAChRs of skeletal muscles and in neurons, thereby blocking the action of ACh at the postsynaptic membrane, inhibiting ion flow and leading to paralysis and death. The nAChR contains two binding sites for snake venom neurotoxins. Progress towards discovering the dynamics of binding action of these sites has proved difficult, although recent studies using normal mode dynamics have aided in predicting the nature of both the binding mechanisms of snake toxins and of ACh to nAChRs.
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The sensory neurons that initially respond are no longer stimulated to respond; this is an example of neural adaptation. All sensory and neural systems have a form of adaptation to constantly detect changes in the environment. Neural receptor cells that process and receive stimulation go through constant changes for mammals and other living organisms to sense vital changes in their environment. Some key players in several neural systems include Ca2+ions (see Calcium in biology) that send negative feedback in second messenger pathways that allow the neural receptor cells to close or open channels in response to the changes of ion flow.
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In 1979, Francis Crick suggested that controlling all cells from one type in the brain while leaving the others more or less unaltered is a real challenge for neuroscience. Francis Crick speculated that a technology using light might be useful to control neuronal activity with temporal and spatial precision but at the time there was no technique to make neurons responsive to light. By early 1990s LC Katz and E Callaway had shown that light could uncage glutamate. Heberle and Büldt in 1994 had already shown functional heterologous expression of a bacteriorhodopsin for light-activated ion flow in yeast.
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Subunit composition of iGluRs heavily influences the efficacy of philanthotoxins. For example, AMPA receptors lacking the GluA2 subunit are highly sensitive to PhTX-433, whereas receptors containing the GluA2 subunit are predominantly insensitive. Study into the exact interactions that occur between the philanthotoxin molecules and the ion channels coupled with glutamate receptors has indicated that the molecules could bind to the narrowest region of the channel, thereby blocking ion flow, and that membrane potential is important to toxin-receptor interaction, making PhTXs highly voltage-dependent antagonists of iGluRs. PhTX-433 inhibits both vertebrate and insect nAChRs predominantly by non- competitively blocking the ion channel in its open conformation.
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Although voltage-gated ion channels are typically activated by membrane depolarization, some channels, such as inward-rectifier potassium ion channels, are activated instead by hyperpolarization. The gate is thought to be coupled to the voltage sensing regions of the channels and appears to contain a mechanical obstruction to ion flow. While the S6 domain has been agreed upon as the segment acting as this obstruction, its exact mechanism is unknown. Possible explanations include: the S6 segment makes a scissor-like movement allowing ions to flow through, the S6 segment breaks into two segments allowing of passing of ions through the channel, or the S6 channel serving as the gate itself.
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Ionotropic glutamate receptors, by definition, are ligand-gated nonselective cation channels that allow the flow of K+, Na+ and sometimes Ca2+ in response to glutamate binding. (In C. elegans and Drosophila, invertebrate-specific subunits enable the flow of negative chloride ions rather than cations.) Upon binding, the agonist will stimulate direct action of the central pore of the receptor, an ion channel, allowing ion flow and causing excitatory postsynaptic current (EPSC). This current is depolarizing and, if enough glutamate receptors are activated, may trigger an action potential in the postsynaptic neuron. All produce excitatory postsynaptic current, but the speed and duration of the current is different for each type.
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Liu 2008 This α7-nAChR functions to allow calcium ion influx into cells, and thus when blocked by ingested bungarotoxin will produce damaging effects, as ACh signaling will be inhibited. Likewise, the use of α-bungarotoxin can be very useful in neuroscience if it is desirable to block calcium flux in order to isolate effects of other channels. Additionally, different forms of bungarotoxin may be useful for studying inhibited nAChRs and their resultant calcium ion flow in different systems of the body. For example, α-bungarotoxin is specific for nAChRs found in the musculature and κ-bungarotoxin is specific for nAChRs found in neurons.
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A solar-powered charger for rechargeable AA batteries During charging, the positive active material is oxidized, producing electrons, and the negative material is reduced, consuming electrons. These electrons constitute the current flow in the external circuit. The electrolyte may serve as a simple buffer for internal ion flow between the electrodes, as in lithium-ion and nickel-cadmium cells, or it may be an active participant in the electrochemical reaction, as in lead–acid cells. The energy used to charge rechargeable batteries usually comes from a battery charger using AC mains electricity, although some are equipped to use a vehicle's 12-volt DC power outlet.
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Neurotransmitter receptors will either signal postsynaptic channels to "open" or "close" which will affect the rates that ions are able to cross the synaptic membrane. The relative change in ion flow will polarize the membrane based on the properties of the affected ion channel. For example, opening a potassium ion channel in the presynaptic membrane will create a flow of positive potassium ions out of the neuron; loss of the positively charged potassium ions will cause the neuron to become more negatively charged. It is through the use of a variety of neurotransmitters and receptors that neurons are able to send a plethora of potential signals to each other.
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Picture of SIFT-MS profile 3. Selected-ion flow-tube mass spectrometry (SIFT- MS) is a quantitative mass spectrometry technique for trace gas analysis which involves the chemical ionization of trace volatile compounds by selected positive precursor ions during a well-defined time period along a flow tube. Absolute concentrations of trace compounds present in air, breath or the headspace of bottled liquid samples can be calculated in real time from the ratio of the precursor and product ion signal ratios, without the need for sample preparation or calibration with standard mixtures. The detection limit of commercially available SIFT-MS instruments extends to the single digit pptv range.
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The causes of cardiac arrhythmias are numerous, from structural changes in the conduction system (the sinoatrial and atrioventricular nodes, or His-Purkinje system) and cardiac muscle, to mutations in genes coding for ion channels of the heart. Movement of ions, particularly Na+, Ca2+ and K+, causes depolarizations of cell membranes in node cells, which are then transmitted to cardiac muscle cells to induce contraction. After depolarization, the ions are moved back to their original locations, leading to repolarization of the membrane and relaxation. Disruptions in ion flow affect the heart's ability to contract by altering the resting membrane potential, affecting the cell's ability to conduct or transmit an action potential (AP), or by affecting the rate or force of contraction.
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Structure of alpha-bungarotoxin (blue) in complex with the alpha-9 nAChR subunit (orange), showing interactions with loops I and II. α-neurotoxins antagonistically bind irreversibly to nAChRs of skeletal muscles, thereby blocking the action of ACh at the postsynaptic membrane, inhibiting ion flow and leading to paralysis. nAChRs contain two binding sites for snake venom neurotoxins. The observation that a single molecule of the toxin suffices to inhibit channel opening is in agreement with experimental data on the amount of toxin per receptor. Some computational studies of the mechanism of inhibition using normal mode dynamics suggest that a twist-like motion caused by ACh binding may be responsible for pore opening, and that this motion is inhibited by toxin binding.
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He coined the names Biefeld–Brown effect and electrogravitics in conjunction with his devices. Brown tested his asymmetrical capacitor devices in a vacuum, supposedly showing it was not a more down-to-earth electrohydrodynamic effect generated by high voltage ion flow in air. Electrogravitics is a popular topic in ufology, anti-gravity, free energy, with government conspiracy theorists and related websites, in books and publications with claims that the technology became highly classified in the early 1960s and that it is used to power UFOs and the B-2 bomber. There is also research and videos on the internet purported to show lifter-style capacitor devices working in a vacuum, therefore not receiving propulsion from ion drift or ion wind being generated in air.
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Celivarone is a non-iodinated benzofuran derivative, structurally related to amiodarone, a drug commonly used to treat arrhythmias. Celivarone has potential as an antiarrhythmic agent, attributable to its multifactorial mechanism of action; blocking Na+, L-type Ca2+ and many types of K+ channels (IKr, IKs, IKACh and IKv1.5), as well as inhibiting β1 receptors, all in dose-dependent manners. The mechanisms by which celivarone modifies ion flow through these channels is unknown, but hearts demonstrate longer PQ intervals and decreased cell shortening, indicative of blocked L-type Ca2+ channels, depressed maximum current with each action potential with no change in the resting membrane potential, caused by blocked Na+ channels, and longer action potential duration due to K+ channel blocks. Celivarone is therefore described as having class I, II, III, and IV antiarrhythmic properties.
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As the electron decays down to the ground state (minimum energy level), energy conservation requires radiation to be emitted by the impurity ion. This emission has discrete values of energy, or wavelength, which correspond to the energy differences between the initial and final atomic levels of a particular electron transition. For example, consider charge exchange between a deuterium atom and a C+6 ion: if the electron is transferred to the n=7 energy level of the carbon ion, then the ion will emit radiation at discrete energies given by the difference in energy between the n=7 and n=6 levels, the n=6 and n=5 levels, the n=5 and n=4 levels, and so on (down to n=1). This line emission is Doppler-broadened as a result of ion thermal motion, and Doppler-shifted as a result of ion flow.
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In the selected ion flow tube mass spectrometer, SIFT-MS, ions are generated in a microwave plasma ion source, usually from a mixture of laboratory air and water vapor. From the formed plasma, a single ionic species is selected using a quadrupole mass filter to act as "precursor ions" (also frequently referred to as primary or reagent ions in SIFT-MS and other processes involving chemical ionization). In SIFT-MS analyses, H3O+, NO+ and O2+ are used as precursor ions, and these have been chosen because they are known not to react significantly with the major components of air (nitrogen, oxygen, etc.), but can react with many of the very low level (trace) gases. The selected precursor ions are injected into a flowing carrier gas (usually helium at a pressure of 1 Torr) via a Venturi orifice (~1 mm diameter) where they travel along the reaction flow tube by convection.
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