(n.) A colorless, tasteless, odorless, gaseous element occurring in the free state in the atmosphere, of which it forms about 23 per cent by weight and about 21 per cent by volume, being slightly heavier than nitrogen. Symbol O. Atomic weight 15.96.
(n.) Chlorine used in bleaching.
Example Sentences:
(1) Steady-state values of cell, glucose, and cellulase concentration oxygen tension, and outlet gas oxygen partial pressure were recorded.
(2) It is concluded that amlodipine reduces myocardial ischemic injury by mechanism(s) that may involve a reduction in myocardial oxygen demand as well as by positively influencing transmembrane Ca2+ fluxes during ischemia and reperfusion.
(3) Heart rate (HR), pulmonary ventilation (V), oxygen consumption (VO2), carbon dioxide production (VCO2), and respiratory quotient (RQ) were measured.
(4) Manometric studies with resting cells obtained by growth on each of these sulfur sources yielded net oxygen uptake for all substrates except sulfite and dithionate.
(5) The data indicate that ebselen is likely to be useful in the therapy of inflammatory conditions in which reactive oxygen species, such as peroxides, play an aetiological role.
(6) These membrane perturbation effects not observed with bleomycin-iron in the presence of a hydroxyl radical scavenger, dimethyl thiourea, or a chelating agent, desferrioxamine, were correlated with the ability of the complex to generate highly reactive oxygen species.
(7) Microelectrodes were used to measure the oxygen tension (PO2) profile within individual spheroids at different stages of growth.
(8) However, time in greater than 21% oxygen was significantly longer in infants less than 1000 g (median 30 days, 8.5 days in patients greater than 1000 g, p less than 0.01).
(9) Previous studies have not evaluated the potential for oxygen toxicity at 9.5 psia.
(10) The pH of ST solutions varied with the mode of oxygenation as follows: 7.9-8.2 in Groups I and IV; 8.7-8.9 in Groups II and V; 7.1-7.4 in Groups III and VI.
(11) The aim of this study was to plot the course of the transcutaneously measured PCO2 (tcPCO2) in the fetus during oxygenation of the mother.
(12) Blood gas variables produced from a computed in vivo oxygen dissociation curve, PaeO2, P95 and C(a-x)O2, were introduced in the University Hospital of Wales in 1986.
(13) Also for bronchogenic carcinoma with that a dependence could be shown between haemoglobin concentration--and by this the oxygen supply of the tumor--and the reaction of the primary tumor after radiotherapy.
(14) The present results using approximately 12% hemoglobin concentration in 0.1 M Bistris buffer at pD 7 and 27 degrees C with and without organic phosphate show that there is no significant line broadening on oxygenation (from 0 to 50% saturation) to affect the determination of the intensities or areas of these resonances.
(15) There was good agreement between the survival of normally oxygenated cells in culture and bright cells from tumors and between hypoxic cells in culture and dim cells from tumors over a radiation dosage range of 2-5 Gray.
(16) In presence of oxygen (air) the phototactic reaction values are somewhat lower than in its absence.
(17) A fiberoptic flow-directed catheter inserted into the hepatic vein continuously measures hepatic venous oxygen hemoglobin saturation (ShvO2).
(18) Anaesthesia was achieved by a mixture of oxygen, nitrous oxide and fluothane without use of muscle relaxants.
(19) The use of 100% oxygen to calculate intrapulmonary shunting in patients on PEEP is misleading in both physiological and methodological terms.
(20) Tachycardia, pulmonary hypertension, increased venous oxygen desaturation, and increasing core temperature develop as the syndrome progresses.
Peroxide
Definition:
(n.) An oxide containing more oxygen than some other oxide of the same element. Formerly peroxides were regarded as the highest oxides. Cf. Per-, 2.
Example Sentences:
(1) The hypothesis that proteins are critical targets in free radical mediated cytolysis was tested using U937 mononuclear phagocytes as targets and iron together with hydrogen peroxide to generate radicals.
(2) The data indicate that ebselen is likely to be useful in the therapy of inflammatory conditions in which reactive oxygen species, such as peroxides, play an aetiological role.
(3) Furthermore, high-density catalase-positive--but not catalase-negative--E. coli can survive and multiply in the presence of competitive, peroxide-generating streptococci.
(4) Studies were conducted in isolated, buffer-perfused rat lungs to determine if prostaglandin (PG) E1 attenuated pulmonary edema provoked by hydrogen peroxide (H2O2).
(5) Spontaneous lipid peroxidation in washed human spermatozoa was induced by aerobic incubation at 32 C and measured by malonaldehyde production; loss of motility during the incubation was determined simultaneously.
(6) Changes in the plasma lipid composition are observed in patients and animals with malignancy and certain other diseases that are consistent with peroxidation of plasma lipoprotein lipids.
(7) Phenobarbital pretreatment increased peroxidation due to exposure of the cells to CCl4 but not that associated with NADPH addition.
(8) Both fatty acid composition and the degree of lipid peroxidation were measured in this study in 23 OTC fish oil preparations.
(9) With the use of two methods, measurement of conjugated dienes and thiobarbituric acid reactivity, brain lipid peroxidation could be documented as a result of exposure to CO at a concentration sufficient to cause unconsciousness.
(10) In the cytochrome P-450-reconstituted system, CCl4 stimulated NADPH-dependent lipid peroxidation of the system containing the P-450 form to a much greater extent than that of the system containing the P-448 form.
(11) The in vivo hepatic lipid peroxide content of rats was increased by aspirin or 4-pentenoic acid (4-PA) administration but was decreased by clofibrate (CPIB) administration.
(12) A water based 5% benzoyl peroxide gel (Benzac W5) was compared with topical 1% clindamycin phosphate solution (Cleocin T) in the treatment of acne vulgaris using a randomized, investigator blind study design.
(13) M & B 22948, a guanosine 3',5'-cyclic monophosphate (cGMP)-selective phosphodiesterase inhibitor, enhanced the vasodilation or relaxation to the peroxide in both preparations.
(14) Accordingly, the 30-fold differences in aging rate among the mammalian species could be determined in part by peroxidation defense processes.
(15) Hence, the 2-NOF:N-acetoxy-N-2-fluorenylacetamide ratios reflect the relative contributions of the two peroxidative pathways to the metabolism of N-OH-2-FAA.
(16) Vanadate-dependent oxidation of either pyridine nucleotide was inhibited by the addition of either superoxide dismutase or catalase, indicating that both superoxide and hydrogen peroxide may be intermediates in the process.
(17) Compared with 39 control subjects, 39 antioxidant-supplemented men experienced the following net reductions during the double-blind period: 20% (P = 0.012) in serum lipid peroxides, 24% (P = 0.035) in ADP-induced platelet aggregation, 42% (P = 0.040) in the rate of ATP release during aggregation, 51% (P = 0.018) in serum (platelet-produced) thromboxane B2, and 29% (P = 0.024) in plasma beta-thromboglobulin concentration.
(18) Protection against O2 toxicity was assessed in terms of lethality and pulmonary edema and of lung lipid peroxidation (assessed by measuring malondialdehyde).
(19) Serum GSSRase activity, however, was significantly decreased while serum vitamin E, and lipid peroxidation levels were significantly increased.
(20) From these results it is suggested that the lipid peroxidation of the brush-border membranes by addition of dithiothreitol plus Fe2+ is sensitively changed with change in ionic strength.