Synthesis of dimethyl carbonate (DMC) from CO2 and methanol under milder reaction conditions was performed using reduced cerium oxide catalysts and reduced copper-promoted Ce oxide catalysts. Although the conversion of methanol was low (0.005-0.11%) for 2 h of reaction, DMC was synthesized as low as 353 K and at total pressure of as low as 1.3 MPa using reduced Cu-CeO2 catalyst (0.5 wt% of Cu)....

AIM To investigate the relation between metabolic parameters of the brain tissue, as direct indicators of real metabolic conditions within the brain, and intracranial pressure, as the consequence of pathophysiological changes. METHODS Twelve patients with closed head injuries were followed up for 24 hours after injury. A Codman parenchymal intracranial pressure and a Neurotrend electrode were...

Modeling and optimization of synthesis gas production via the non-catalytic partial oxidation of methane (NCPO) were studied by minimizing of Gibbs free energy, and comparison studies were carried out to analyze the mechanism of syngas production. For this purpose, concentrations of CO2 and H2O in the feed were optimized in specified pressure and temperature, such that the hydrogen to carbon mo...

We sought to characterize and quantify the performance of a portable dynamic end-tidal forcing (DEF) system in controlling the partial pressure of arterial CO2 (Pa(CO2)) and O2 (Pa(O2)) at low (LA; 344 m) and high altitude (HA; 5,050 m) during an isooxic CO2 test and an isocapnic O2 test, which is commonly used to measure ventilatory and vascular reactivity in humans (n = 9). The isooxic CO2 te...

We examined the physiological responses of steady-state iron (Fe)-replete and Fe-limited cultures of the biogeochemically critical marine unicellular diazotrophic cyanobacterium Crocosphaera at glacial (19 Pa; 190 ppm), current (39 Pa; 380 ppm), and projected year 2100 (76 Pa; 750 ppm) CO2 levels. Rates of N2 and CO2 fixation and growth increased in step with increasing partial pressure of CO2 ...

BACKGROUND Carbon dioxide (CO2) insufflation is increasingly used for endoscopic submucosal dissection (ESD) owing to the faster absorption of CO2 as compared to that of air. Studies comparing CO2 insufflation and air insufflation have reported conflicting results. OBJECTIVES This meta-analysis is aimed to assess the efficacy and safety of use of CO2 insufflation for ESD. METHODS Clinical t...

Two respiratory physiotherapy methods were evaluated by analyzing changes in the transcutaneous partial pressure of CO2 (tcPCO2) in 15 patients with respiratory insufficiency. All were receiving continuous oxygen therapy and had CO2 retention. The physiotherapy methods compared were thoracic compression (TC) and positive expiratory pressure (PEP). The mean decrease (+/- SD) in tcPCO2 was the sa...

Ap effective pore area CAM chorioallantoic membrane CO cardiac output CO2 carbon dioxide dCO2 carbon dioxide diffusion coefficient dH2O water vapor diffusion coefficient dO2 oxygen diffusion coefficient DO2 oxygen diffusing capacity EP external pipping FcOX mean corpuscular oxygenation velocity GCO2 carbon dioxide conductance GH2O water vapor conductance GO2 oxygen conductance Hb hemoglobin Hct...

Background: We measured Functional Residual Capacity (FRC) of the lungs with a CO2 partial rebreathing technique, first in a mechanical lung analog, and then in mechanically ventilated animals before, during, and subsequent to an acute lung injury induced by oleic acid. We compared the FRC from partial CO2 rebreathing with those of a nitrogen washout reference method. Materials and Methods: Usi...

Extracorporeal CO2 removal devices (ECCO2R) can be used in clinics to decarboxylate blood externally for patients suffering from pulmonary insufficiencies like acute respiratory distress syndrome. In this work, we propose a model of the respiratory system coupled with such a device to analyze the decrease of CO2 partial pressure in the blood as a function of the blood flow through the device. T...