Though the equation appears complex, it simply means that the oxygen tension in the alveoli is predominantly determined by the concentration of inspired oxygen, the barometric pressure and the carbon dioxide tension in the alveoli. Because carbon dioxide is very freely diffusible across the alveolar membrane, often arterial and alveolar carbon dioxide tension will be equal. That is why PaCO2 wh...

BACKGROUND/AIM Hypoxia and carbon dioxide rebreathing are potential problems during eye surgery in spontaneously breathing patients. The aim of the present study was to determine effectiveness of nasal application of oxygen to prevent hypoxia and carbon dioxide accumulation in spontaneously breathing patients undergoing cataract surgery. METHODS Oxygenation and carbon dioxide rebreathing were...

In this work, the adsorption of carbon dioxide from model flue gas on different adsorbents has been investigated. Using simplified modeling, parameters such as the total mass transfer coefficient and the effective diffusivity have been determined. Experiments were carried out in two sections: firstly, adsorption of pure carbon dioxide on different adsorbents was measured at pressures ranging fr...

Copper trimesate (Cu-BTC) MOF has been pointed out as a promising adsorbent for separating carbon dioxide from methane. However, MOF’s need to be shaped prior to their use in packed bed adsorbers in order to reduce pressure drop; on the other hand, the production of mechanically resistant shaped bodies reduces their adsorption performance. In this work, Cu-BTC tablets provided by BASF are evalu...

The duration of respiratory depression induced by morphine 10 mg/70 kg was studied following the administration of one of two opioid antagonists. Respiratory measurements included: (i) the ventilatory response to carbon dioxide, described in two ways--the minute ventilation at an end-tidal carbon dioxide partial pressure of 8 kPa (VE8) and the log slope of the ventilatory response to carbon dio...

BACKGROUND AND AIMS The inverse relationship between atmospheric CO2 partial pressure (pCO2) and stomatal frequency in many species of plants has been widely used to estimate palaeoatmospheric CO2 (palaeo-CO2) levels; however, the results obtained have been quite variable. This study attempts to find a potential new proxy for palaeo-CO2 levels by analysing stomatal frequency in Quercus guyavifo...

[1] The gradient in the partial pressure of carbon dioxide (pCO2) across the air-sea boundary layer is the main driving force for the air-sea CO2 flux. Global data bases for surface seawater pCO2 are actually based on pCO2 measurements from several meters below the sea surface, assuming a homogeneous distribution between the diffusive boundary layer and the upper top meters of the ocean. Compil...

The authors describe a new methodologically improved behavioral treatment for panic patients using respiratory biofeedback from a handheld capnometry device. The treatment rationale is based on the assumption that sustained hypocapnia resulting from hyperventilation is a key mechanism in the production and maintenance of panic. The brief 4-week biofeedback therapy is aimed at voluntarily increa...

Three commercially-available combined PO2-PCO2 electrodes were assessed in vitro, and in adults breathing air, hypoxic and hypercapnic mixtures, for speed of response, correlation with end-tidal gas tensions and drift. Differences in the 90% response time of the individual electrodes were more marked in vitro than in vivo. Changes in end-tidal gas tensions were reflected by proportionate change...

[1] The role of saline lakes in CO2 exchange with the atmosphere was evaluated on the basis of calculated partial pressure (pCO2) and CO2 exchange rates with the atmosphere derived from a compilation of published data for 196 saline lakes around the world. The average surface water pCO2 exceeded atmospheric pCO2 by a factor of 5–8 times, indicative of a tendency for saline lakes to emit CO2 to ...