1. Oxygen breath tests were performed in nine patients with diffuse pulmonary infiltration whose resting arterial PO2 (Pa, O2) ranged from 8-9 kPa to 11-8 kPa. The inspired air was suddenly replaced with oxygen for 30 s and the percentage fall in ventilation over the last 10 s was measured. 2. Pa,O2 rose rapidly and exceeded 16 kPa within 20 s in each patient. 3. The ventilation fell significan...

The experiments reported in this paper are concerned with the inhibitory action of oxygen at 1 atmosphere pressure on the carbohydrate metabolism of heart muscle studied in vitro. It has been observed by several investigators that oxygen at 1 atmosphere pressure may have a harmful effect on the metabolism of mammalian tissue in vitro or on individual enzyme systems (l-5). Dickens (6, 7) and Sta...

microembolic signals (mes) are frequently observed in transcranial ‎doppler (tcd) recordings of patients with mechanical heart valve (mhv). if gaseous bubbles are the underlying cause, number of mes produced by mhv could be reduced with oxygen ‎inhalation. from september 2003 to september ‎2004, a consecutive series of 14 patients ‎with st jude aortic valve visited in the cardiology clinic were...

introduction: hypoxemia can occur during upper gastrointestinal endoscopy with or without pharmacological sedation. pulse oximetry saturation (spo2) levels were assessed in patients attending for routine unsedated diagnostic upper gastrointestinal endoscopy to identify factors associated with oxygen desaturation. methods: a total of 300 patients who underwent upper gastrointestinal endoscopy wi...

The mechanisms by which the placenta adapts to exogenous stimuli to create a stable and healthy environment for the growing fetus are not well known. Low oxygen tension influences placental function, and is associated with preeclampsia, a condition displaying altered development of placental trophoblast. We hypothesized that oxygen tension affects villous trophoblast by modulation of gene expre...

CaMnO(3) and Ca(2)Mn(3)O(8) were synthesized and characterized by SEM, XRD, FTIR and BET. Both oxides showed oxygen evolution activity in the presence of oxone, cerium(IV) ammonium nitrate and H(2)O(2). Oxygen evolution from water during irradiation with visible light (λ > 400 nm) was also observed upon adding these manganese oxides to an aqueous solution containing tris(2,2'-bipyridyl) rutheni...

In this work, the thermal reaction of aluminum (Al) and nickel oxide (NiO) was investigated by molecular dynamics simulations. Some effective features of reaction such as reaction temperature, the reaction mechanism, and diffusion rate of oxygen into aluminum structure were studied. ReaxFF force field was performed to study the Al/NiO thermite reaction behavior at five different temperatures (5...

AIM To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide. METHODS Domestic pigs were used as experimental animals. Oxygen tension was measured by means of a polarographic electrode in the vitreous...

Intracellular singlet oxygen generation in photofrin-loaded cells caused cell death without discrimination between nonmalignant and malignant cells. In contrast, extracellular singlet oxygen generation caused apoptosis induction selectively in tumor cells through singlet oxygen-mediated inactivation of tumor cell protective catalase and subsequent reactivation of intercellular ROS-mediated apop...