noun
COLLOCATIONS FROM CORPUS
■ ADJECTIVE
negative
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It is charged with negative ions which generate a feeling of well-being.
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But if the receptor lets in negative ions , the downstream neuron is made more resistant to firing.
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But if positive and negative ions are separated and concentrated, a charge difference is developed-a difference measured in volts.
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If negative ions predominate, nothing happens.
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The cell is already negative and so adding more negative ions just pushes the cell farther in an electrically negative direction.
positive
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Negative ions pass through a membrane containing positive ions more easily than through one that is neutral or negatively charged.
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If the ion channel lets positive ions into the receiving neuron, the neuron is pushed toward firing.
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Plasma consists of positive ions and unbound electrons.
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When glutamate is released into a synapse, it docks at a receptor that lets positive ions rush in.
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As the impulse passes any point on the fibre, the membrane allows a sudden thrust of positive sodium ions .
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These channels let in a flood of even more positive ions , which obliterates the electrical charge at that spot.
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The positive ions are accelerated to a narrow beam by the use of negative plates and a high voltage.
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At low pressures, a plasma is established with a discharge of positive ions travelling towards the cathode.
■ NOUN
calcium
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As with Aplysia, a key player in this process appears to be calcium ions .
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The mineral calcite is made up of carbonate sheets and intervening planes of calcium ions .
channel
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This results in the neighbouring part of the axon also reaching this potential, thus causing its ion channel to open.
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And the particular proteins now under scrutiny are the ion channels we met earlier.
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For example, plasticity seems to depend on identifiable ion channels and catalytic molecules that activate or inhibit these channels.
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Sometimes receptors are ion channels , and the docking trips the channel open.
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The sodium is only able to pass into the membrane through sodium ion channels distributed along the axon.
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If the ion channel lets positive ions into the receiving neuron, the neuron is pushed toward firing.
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Here on the tongue, ion channels play a critical role in our sense of taste.
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Drifting away from the quivering ion channel , you notice legions of ethanol mol-Figure 2.
chloride
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What is important is that all the chlorine in the VOCs ends up as chloride ion rather than other potentially hazardous chlorinated compounds.
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More recent evidence suggests that there is cotransport of sodium, potassium, and two chloride ions together at this site.
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Burgmayer and Murray then used this membrane to separate two solutions containing negatively charged chloride ions .
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Both sodium and chloride ions are in six-coordination.
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At the same time the enterotoxin also promotes a net secretion of chloride ions into the gut lumen from the epithelial cells.
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When there are no chloride ions left in the specimen to react, the end-point is reached.
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The membrane starts off positively charged, and chloride ions can pass through easily.
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Some of the excess chloride ions in the lumen are exchanged for bicarbonate ions at the surface of the epithelium.
concentration
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The World Health Organisation recommends a sodium ion concentration of 90mmol/l.
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This is a symbol expressing hydrogen ion concentration in a solution; it is a measure of relative acidity or alkalinity.
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Acid output was calculated by multiplying the hydrogen ion concentration by the volume of the gastric aspirate.
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Conversely, in acidemia, the extracellular hydrogen ion concentration increases.
exchange
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The process produces a much smaller volume of chemically inert radioactive waste than conventional ion exchange techniques.
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A commercial filtering medium now on the market combines activated carbon and an ion exchange resin.
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The trade name Permutit was given to this patented ion exchange process, it being derived from the Latin verb to exchange.
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Protein bound leucine Leucine was separated from other amino acids in the protein hydrolysate by preparative ion exchange chromatography.
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An ion exchange process creates an aqueous slurry of platelets of molecular dimensions.
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The chapter focus then switches to chromatographic modes, reversed phase, ion exchange and size exclusion being examined.
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Check, recharge and/or change as required any ion exchange media that you may be using on a frequent and routine basis.
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Having proposed suitable nomenclature for gas chromatography and ion exchange , the commission then developed a unified nomenclature for chromatography.
hydrogen
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Proton concentrations for each sample were then calculated from the hydrogen ion activity and the combined sodium and potassium concentrations.
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Treatment is aimed at decreasing hydrogen ion loss.
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The principal body electrolytes are sodium, potassium and hydrogen ions .
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Diuretics should be stopped, if possible, to decrease renal hydrogen ion loss.
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Bennett and Williams suggest that the cells of opening or closing traps acidify their own walls by releasing hydrogen ions .
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This is a symbol expressing hydrogen ion concentration in a solution; it is a measure of relative acidity or alkalinity.
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The timing of active hydrogen ion secretion, however, remains unknown.
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Hypocapnia causes fewer hydrogen ions to be available for secretion in the renal tubular cell.
magnesium
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This displaces the calcium and magnesium ions from the resin and restores it to the sodium form.
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Typically a magnesium ion diffuses into the channel and gets trapped, unable to go all the way through.
metal
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The hydration enthalpies of some alkali metal ions and halide ions are shown in table 5.11.
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Trace metal ions in the solution are thereby reduced and plated on to the anodic electrode.
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Could metal ions be made to stick on to the outside of the fullerene football?
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For this reason concentrations of potentially interfering metal ions approximating the serum levels are used in the standards.
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High-temperature gas cleaning techniques remove the water and metal ions which are a natural constituent of silica glass, and attenuate light.
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Distortions due to the formation of hydrogen bonds are usually smaller than those due to co-ordination to metal ions .
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The nuclear industry produces waste streams which contain a variety of radioactive metal ions , the extraction of which minimises radioactive discharges.
sodium
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Pancreatic juice for example contains a high concentration of sodium ions , and variable concentrations of chloride and bicarbonate ions.
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Should the supply of sodium ions presented to the distal exchange sites decrease, potassium excretion decreases also.
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As the impulse passes any point on the fibre, the membrane allows a sudden thrust of positive sodium ions .
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Typically, sodium ions are excluded and potassium ions are hoarded.
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Following this permeability change, the sodium ions are pumped out from the fibre so restoring the original state.
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It allows sodium ions into the dendrite, which raises its voltage temporarily.
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The World Health Organisation recommends a sodium ion concentration of 90mmol/l.
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That blast of sodium ions entering the neuron is the impulse starting.
transport
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Potential difference did not change during the observed effects in ion transport in our study.
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The first changes of net water and ion transport were observed after the second or third hour after administration of cholera toxin.
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Cell scientists don't yet know how natural systems control ion transport .
■ VERB
charge
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It is charged with negative ions which generate a feeling of well-being.
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Sodium has a strong tendency to lose an electron and become the positively charged ion Na.
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These fixed negative charges attract a layer of residual positively charged ions which are free to move within the water.
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These positively charged ions are themselves highly hydrated.
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Hence when a current is applied, the positively charged ions move toward the cathode carrying water molecules with them.
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Some think the diet changes the rate at which electrically charged particles called ions cross the lipid membranes of nerve cells.
use
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This is an accelerator constructed for nuclear structure research using heavy ions , and it can produce exotic nuclei.
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Kilowatt-size ion drives do exist and some satellites use ion engines for manoeuvring purposes.
EXAMPLES FROM CORPUS
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A commercial filtering medium now on the market combines activated carbon and an ion exchange resin.
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Generally, one cupric ion complexes with four to six peptide linkages.
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However, such secretions also contain important ions which are essential for the normal functioning of the body.
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It only works in the direction in which it's throwing the ions.
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That blast of sodium ions entering the neuron is the impulse starting.
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The cliff top turf was bright with thrift and sea camp ion .
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The result is an excluded volume behind the target atom into which no ions penetrate.
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Typically, sodium ions are excluded and potassium ions are hoarded.