(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.
Ozone
Definition:
(n.) A colorless gaseous substance (O/) obtained (as by the silent discharge of electricity in oxygen) as an allotropic form of oxygen, containing three atoms in the molecule. It is a streng oxidizer, and probably exists in the air, though by he ordinary tests it is liable to be confused with certain other substances, as hydrogen dioxide, or certain oxides of nitrogen. It derives its name from its peculiar odor, which resembles that of weak chlorine.
Example Sentences:
(1) We studied the effect of a 2-hour exposure to 0.6 ppm of ozone on bronchial reactivity in 8 healthy, nonsmoking subjects by measuring the increase in airway resistance (Raw) produced by inhalation of histamine diphosphate aerosol (1.6 per cent, 10 breaths).
(2) Carbon monoxide accelerates the reaction as measured by nitric oxide oxidation or ozone formation.
(3) It is suggested that the atmosphere of Athens favours the formation of secondary direct-acting mutagens due to the oxidation and nitration of PAH by ozone and nitrogen oxides, which are more abundant in the late spring months.
(4) Therefore, more research of the effects of ozone on birds seems to be necessary, both from a mechanistic and an ecological point of view.
(5) Using this assay, we studied the effects of exposure to ozone (O3), hexachlorobenzene (HCB), and bis(tri-n-butyltin)oxide (TBTO) on NK activity in rat lung.
(6) The campaign’s focus was the damage to the ozone layer caused by fluorinated gases, such as HFCs.
(7) Particular attention was given to both the qualitative and quantitative evaluation of ciliated cells in the nasal respiratory epithelium in response to ozone exposure.
(8) Results indicate also that ozone sensitivity, radiosensitivity, and mucoidy are pleiotropic properties of the lon gene.
(9) Endothelial prostacyclin synthesis returned to baseline levels by 12H after ozone exposure, a time point which was similar to the recovery time of unexposed endothelium treated with 0.5 uM acetylsalicylic acid.
(10) After ozone-exposed mice had been returned to ambient air for 10 days, ciliary regeneration occurred and, the major airways had a surface appearance approaching the normal state.
(11) Pulmonary fibrosis is a consequence of severe injury from some toxic agents including high doses of ozone.
(12) In the first experiment, rats were fed fat-free diets and exposed to ozone for 0, 1, 2, and 4 weeks.
(13) A mathematical model of ozone absorption, or for any soluble gas that has similar transport properties, is developed for a branching network of liquid-lined cylinders.
(14) Serial exposures to peak levels of ozone on several consecutive days are more characteristic of pollution episodes in the Northeast United States and may be associated with recurrent symptoms.
(15) The enhancement of metastasis due to ozone exposure varied with length of exposure and concentration of ozone.
(16) The present data indicate that the incidence of skin cancer would increase by approximately 2% for each percent ozone reduction.
(17) And yet, trusting the science, and with international leadership, an agreement – the Montreal Protocol – was signed within two years of the discovery of a hole in the ozone layer in the southern polar region.
(18) Ozonized water placed in an open dish kept up antimicrobial activity for the first 20 minutes, but after 30 minutes this activity decreased substantially.
(19) However, single, 40-min exposures of RTE cells to approximately 10 ppm ozone did result in approximately 40% decreases in colony-forming efficiency.
(20) The present studies were undertaken to examine the effects of exposing asthmatics to ozone concentrations that occur in the environment.