In dogs anaesthetized with either halothane or chloralose cardiac output was measured at three levels of arterial carbon dioxide tension. As the carbon dioxide tension was raised there were significant increases in cardiac output. After the administration of a selective cardiac beta-receptor blocking agent (practolol) there were no significant changes in cardiac output as the carbon dioxide ten...

A silicon micromachining method that is able to create deep silicon dioxide blocks at selected locations in a silicon substrate is presented. The process combines deep-reactive-ion etching (DRIE), thermal oxidation, deposition of silicon dioxide and optional planarization. Design issues and parameters for the creation of such blocks are discussed. The selectively defined silicon dioxide blocks ...

We have studied 14 female patients undergoing elective laparoscopy under general anaesthesia with peritoneal insufflation of carbon dioxide in order to examine changes in physiological deadspace (VDphys), arterial to end-tidal carbon dioxide partial pressure difference (PaCO2-PE' CO2) and PaCO2. VCO2 increased after insufflation of carbon dioxide with a mean (SD) maximum increase of 32 (28)% co...

We present three patients with respiratory failure in whom conventional mechanical lung ventilation resulted in unacceptably high levels of carbon dioxide, severe acidosis and high vasopressor requirements. A pumpless arteriovenous extracorporeal carbon dioxide removal device (Novalung) was inserted. Arterial carbon dioxide levels were reduced rapidly with a corresponding increase in pH, reduct...

The metabolism of rat retina was found to be sensitive to the concentration of the carbon dioxide-bicarbonate buffer system. Increasing the carbon dioxide from 1 per cent to 5 per cent at constant pH nearly doubled both respiration and glycolysis. Increasing the carbon dioxide at constant pH from 5 per cent to 20 per cent had no effect on glycolysis, but depressed the Q(O(O2) ) from 31 to 19. I...

Chlorine dioxide is a disinfectant used worldwide. In this article, a new enzymatic method for the determination of chlorine dioxide has been developed. This rapid spectophotometric assay is able to detect from 0.2 to 4 mg/liter of chlorine dioxide. The method is based on the capacity of horseradish peroxidase to decolorize reactive yellow 17 in the presence of chlorine dioxide. The effects of ...

Titanium is a successful biomaterial that possesses good biocompatibility. It is covered by a surface layer of titanium dioxide, and this oxide may play a critical role in inhibiting reactive oxygen species, such as peroxynitrite, produced during the inflammatory response. In the present study, titanium dioxide was coated onto silicone substrates by radio-frequency sputtering. Silicone coating ...

For the purpose of estimating a very small amount of carbon dioxide in general biological problems, two pieces of apparatus have been already described.* The principle of the apparatus is as follows : 1. Exceedingly minute quantities of carbon dioxide can be precipitated as barium carbonate on the surface of a small drop of barium hydroxide solution. 2. When a drop of barium hydroxide is expose...

Assessment of blood gas status is important in the management of patients with chronic pulmonary disease. Arterial puncture is often painful and may damage the arterial wall. Measurement of oxygen saturation by transcutaneous oximetry offers a non-invasive alternative to arterial methods but does not allow assessment of partial pressure of carbon dioxide. We have examined the value of oximetry ...

Photosynthetic oxygen evolution by isolated spinach (Spinacia oleracea L.) chloroplasts approached complete inhibition in the presence of a 5 mm concentration of sulfur dioxide. A similar inhibition was observed in the presence of equimolar concentrations of bisulfite ions, suggesting a parallel mode of action. In contrast, an equimolar concentration of sulfite ions was markedly less inhibitory...