(a.) Not permeable; not permitting passage, as of a fluid. through its substance; impervious; impenetrable; as, India rubber is impermeable to water and to air.
Example Sentences:
(1) On the other hand, changing pH on only one side by addition of an impermeant buffer fails to induce any change in n. At the single-channel level, pH had an effect both on the unitary conductance, doubling it in going from pH 4.5 to 8.2, as well as on the fraction of time the channels stay open, F(v).
(2) EAI can penetrate a membrane, whereas IAI is membrane impermeant.
(3) Both the internal and external solutions were prepared with impermeant anions.
(4) Replacement of Cl-o with other impermeant anions, such as gluconate and methylsulphate, had a similar action on contractile activity as for Ise-replacement.
(5) When sulfhydryl groups present at the cell surface were blocked with cell-impermeant sulfhydryl reagent, the initial phase of disulfide cleavage was inhibited, indicating that cleavage began at the cell surface.
(6) To explain the opposite effects of GTP in the absence and presence of oxalate, it is proposed that GTP activates a transmembrane conveyance of Ca2+ between oxalate-permeable and -impermeable compartments.
(7) Measurement of (140)La uptake by the living skin shows that lanthanum moves across the external surface of the skin readily, into and out of a compartment that has a limited capacity and is bounded on its internal side by a barrier impermeable to lanthanum.
(8) When permeant anions in the bath (Cl-) were replaced with relatively impermeant anions (gluconate, MOPS, propionate, or Hepes), the Po vs. voltage relationship was shifted by approximately -35 mV.
(9) Currents through both the voltage-activated potassium channels, IK,V, and the calcium-activated potassium channels, IK,Ca, can be blocked by the membrane-impermeant K channel blocker tetraethylammonium (TEA).
(10) The outcome is a belief that the Earth is being slowly strangled by a gaudy coat of impermeable plastic waste that collects in great floating islands in the world's oceans; clogs up canals and rivers; and is swallowed by animals, birds and sea creatures.
(11) Local hypoxia due to a diffusion block by the impermeable pericapillary cuffs, partially due to a reduction of capillaries in the superficial layers.
(12) The connective hyperpolarizes in the propionate saline, whereas the abdominal region undergoes the transient depolarization that is expected when a permeant anion (Cl) is replaced with an impermeant one (propionate).
(13) In forest, removal of olfactory substances from the human skin, by vigorous washing and application of petroleum jelly, or by wearing impermeable clothing, greatly reduced the numbers of flies attracted.
(14) By the use of double-chamber tissue culture flasks, with the 2 cell populations separated by a cell impermeable membrane, it was found that T-T interaction does not require cell contact and is thus mediated by factor(s).
(15) This discrepancy could be ascribed to impermeability, as E. coli cells with modified permeability show greater sensitivity to minosaminomycin.
(16) The perinephric membrane in the Lepidoptera is impermeable to the dyes.
(17) The relatively membrane-impermeant pyridoxal phosphate labels all proteins of the intact myelin except basic protein.
(18) Monobromobimane and dibromobimane are effective on intact cells while red cell membranes may be impermeable to the positively charged monobromotrimethylammoniobimane, the latter being effective only on lysed cells.
(19) This failure was shown to be due to the impermeability of mycobacteria to these drugs by use of "membrane-active" agents along with the antibiotics in growth inhibition studies.
(20) Chloride dependence was assessed by replacing chloride with the impermeant anion gluconate, or by addition of the anion transport blocker 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS).
Permeability
Definition:
(n.) The quality or state of being permeable.
Example Sentences:
(1) We conclude that chloramphenicol resistance encoded by Tn1696 is due to a permeability barrier and hypothesize that the gene from P. aeruginosa may share a common ancestral origin with these genes from other gram-negative organisms.
(2) These effects are similar to those reported for AVP and phorbol esters, activators of protein kinase C. Forskolin and isoproterenol, which induce cAMP accumulation, activated extractable topoisomerase II (maximum 5-15 min after treatment), but not topoisomerase I. Permeable cyclic nucleotide analogs dBcAMP and 8BrcGMP selectively activated extractable topoisomerase II and topoisomerase I activities, respectively.
(3) Inhibition of thymidine uptake is attributed to an observed decrease in thymidine kinase activity caused by growth in 1 mM dibutyryl cyclic AMP, and possibly to a simultaneous alteration in membrane permeability.
(4) In the course of the syndrome development blood vessel permeability was increased in the anterior chamber of the eye.
(5) This promotion of repetitive activity by the introduction of additional potassium channels occurred up to an "optimal" value beyond which a further increase in paranodal potassium permeability narrowed the range of currents with a repetitive response.
(6) [125I]AaIT was shown to cross the midgut of Sarcophaga through a morphologically distinct segment of the midgut previously shown to be permeable to a cytotoxic, positively charged polypeptide of similar molecular weight.
(7) Catheters containing 0% and 10% heparin were compared in each individual using ultrasound microflow velocimetry, permeability test, sequential determinations of activated partial thromboplastin time, heparin levels and generation of Fibrinopeptide A, beta thromboglobulin and Platelet factor 4.
(8) Comparison of the 50% binding concentrations of the compounds for the various PBPs of the five strains with their antibacterial activity indicates that the different antibiotics are excluded to a greater or lesser degree by the outer membrane permeability barrier and that the exclusion is most pronounced in P. aeruginosa.
(9) Immunoactive levels of DSIP in the plasma correlated with brain immunoactive levels and with BBB permeability to 125I-DSIP.
(10) Cellular aging is accompanied by increased cellular permeability to zinc(II).
(11) These results indicate that FMLP increased a pulmonary microvascular permeability in isolated buffer-perfused rabbit lungs that is PMN dependent and mediated by LT produced possibly by a result of ROS production.
(12) Dacryography is the only means of exploring the permeability of the lacrymal ducts and to conclude as the whether watering of the eyes is organic or functional.
(13) Rhesus monkey BAT mitochondria (BATM) possess an uncoupling protein that is characteristic of BAT as evidenced by the binding of [3H]GDP, the inhibition by GDP of the high Cl- permeability or rapid alpha-glycerol-3-phosphate oxidation.
(14) Whereas the tight junctions of endoneurial capillaries are known to prevent certain blood-borne substances from entering the endoneurium, it was not clear whether the permeability of the pulpal capillaries, which are distant from the nerve fibres, could affect the nerve fibre environment.
(15) In the companion paper, we quantitatively account for the observation that the ability of a solute to promote fusion depends on its permeability properties and the method of swelling.
(16) [14C]Sucrose biliary clearance increased in treated animals, suggesting an increased permeability of the biliary system to sucrose.
(17) The stimulation was not due to increased permeability of the inner mitochondrial membrane.
(18) The roles of Mg, K, Na, and Cl ions in the biphasic K-permeability response (86Rb release) to receptor activation in the parotid gland were investigated.
(19) Investigation of the mechanism of action of the synergistic effect between kanamycin and HA led to the tentative conclusion that potentiation was mediated through an initial alteration of cell permeability by the aminoglycoside antibiotic which permitted accumulation of each of the six HA into the cell, at which point each interacted with pyridoxal phosphate.
(20) Values obtained for the permeability of the epithelium of each of these regions, after separation from the connective tissue with EDTA, did not differ significantly from those obtained for the intact tissue; however, the connective tissue alone had a permeability 2-8 times greater than that of the whole tissue.