Minute volume

Anthropologic features of humans, their physical activities, ventilation capacities, and the state of their circulation all affect exposure to chemical compounds. Some of the physiological determinants of exposure will be dealt with below. Exercise typically increases cardiac output, facilitates circulation, increases the minute volume of ventilation, is associated with vasodilation of the skin circulation, and increases perspiration and secretory activity of the sweat glands. All of these changes tend to facilitate the absorption of chemicals through multiple routes. 

In an alternative procedure designed to deal with minute volumes of liquid, Walter38 set up a layer cell based upon the technique employed in instant colour photographic films, Such a cell designed to determine potassium ions made use of two layer assemblies terminating in valinomycin electrodes, so that with a standard potassium chloride solution added to one assembly, and the... 

When considering the thermal management of very exothermic reactions and the avoidance of corresponding explosions, it is the minute volume of micro readors that is addressed [4]. 

Hyphenation in capillary electrophoresis is still in its infancy. Critical aspects of CE hyphenation include the minute volumes of sample injected (typically a few nL) and small flow-rates (in the order of nLmin-1). Interfaces are not commercially available. CZE-UV can be used for the analysis of higher polyamide oligomers in HF1P solution [859]. A solvent elimination design with nebuliser has been described for CE-FTIR and CEC-FTIR coupling absolute detection limits are hundreds of pg [860]. An advantage of CE-FTIR is that analytes may be detected and identified without derivatisation. CE(C)-NMR [861-863] is advancing rapidly. 

Total ventilation. The total ventilation (minute volume) is the volume of air that enters the lungs per minute. It is determined by tidal volume and breathing frequency ... 

Subsequently, individual data on exposure are converted to dose by using conversion factors (OECD/NEA, 1983). The choice of the appropriate numerical value depends on physiological parameters (e.g. respiratory minute volume) as well as physical characteristics of the inhaled aerosol (e.g. particle size). Mean values range typically from about 5 mSv/WLM (non-occupational exposure) to about 10 mSv/WLM (occupational exposure). 

The resulting AEGL-3 values are shown in Table 3-11. Conversion of animal exposure data to human equivalent concentrations based upon minute volume and body weight relationships was not appropriate. Such a conversion predicted that monkeys and dogs would be more sensitive than rodents, a contention that is not supported by the animal data. Furthermore, the conversion to human equivalent concentrations assumes 100% absorption of inhaled monomethylhydrazine such absorption efficiency has not been verified. 

Six male Wistar rats inhaled HCN at 55 ppm for 30 min (Bhattacharya et al. 1984). HCN was generated by reaction of KCN with sulfuric acid and circulated through the chamber at the rate of 1 L/min. The rats were fitted with a lung mechanics analyzer (Buxco Electronic Inc.), and changes in air flow, transthoracic pressure, tidal volume, compliance, resistance, respiratory rate, and minute volume were determined every 10 min. Animals were sacrificed immediately following the exposure, and lungs were excised and analyzed for phospholipids (surfactant). 

The absorption of inhaled -hexane has been investigated in six healthy male volunteers (Veulemans et al. 1982). Three different trials were performed on each volunteer 4-hour exposure at 102 ppm -hexane 4-hour exposure at 204 ppm, and exposure during exercise on a stationary bicycle ergometer at 102 ppm. Each trial was done at least two weeks apart. Lung clearance (from alveolar air to blood) and retention were calculated from -hexane concentrations in inhaled and expired air. After exposure, /7-hcxane in exhaled air was measured for up to 4 hours to determine respiratory elimination. Retention of -hexane (calculated from lung clearance and respiratory minute volume) was approximately 20-25%... 

Species Body Weight (kg) Lung Volume (ml) Minute Volume (ml min-1) Alveolar Surface Area (m2) Lung Volume % Surface Area Minute Volume % Lung Volume Minute Volume % Surface area... 

By simultaneous monitoring of tidal volume and respiratory rate, or minute volume, and the concentration of an inhaled vapor in the bloodstream and the vapor in the exposure atmosphere, pharmacokinetic studies on the C t relationship have shown that the effective dose was nearly proportional to the exposure concentration for vapors such as 1,1,1-trichloroethane (Dallas et al., 1986), which has a saturable metabolism, found that the steady-state plasma concentrations were disproportion-ally greater at higher exposure concentrations. 

At Paco2 of 5 kPa The line should demonstrate that, under normal conditions, the minute volume (MV) remains relatively constant around 6 l.min 1 until the Pao2 falls below 8 kPa. Show that the rise in MV following this is extremely steep. This illustrates the hypoxic drive, which is so often talked about in the setting of COPD. 

PaC02 in vivo, respiration rate, tidal volume, minute volume Responses to C02 and NaCN... 

Respiratory Respiration rate, inspiratory and expiratory times, tidal volume, minute volume, peak inspiratory, and expiratory flows Whole body piety smography Rat McMahon et al.185... 

Desflurane causes an increase in the rate of ventilation, a decrease in tidal volume, and a decrease in minute volume as inspired concentrations only slightly exceed 1 MAC. Thus should anesthesiologists require desflurane to be administered near or above MAC levels, patients are likely to have marked reductions in PCO2. 

Three-dimensional (3D) structuring of materials allows miniaturization of photonic devices, micro-(nano-)electromechanical systems (MEMS and NEMS), micro-total analysis systems (yu,-TAS), and other systems functioning on the micro- and nanoscale. Miniature photonic structures enable practical implementation of near-held manipulation, plasmonics, and photonic band-gap (PEG) materials, also known as photonic crystals (PhC) [1,2]. In micromechanics, fast response times are possible due to the small dimensions of moving parts. Femtoliter-level sensitivity of /x-TAS devices has been achieved due to minute volumes and cross-sections of channels and reaction chambers, in combination with high resolution and sensitivity of optical con-focal microscopy. Progress in all these areas relies on the 3D structuring of bulk and thin-fllm dielectrics, metals, and organic photosensitive materials. 

Morphine depresses all phases of respiration (respiratory rate, tidal volume, and minute volume) when given in subhypnotic and subanalgesic doses (Figure 47.6). In humans, a morphine overdose causes respiratory arrest and death. Therefore, morphine and other narcotic analgesics should be used with extreme caution in patients with asthma, emphysema, and cor pulmonale, and in disorders that may involve hypoxia, such as chest wound, pneumothorax, or bulbar poliomyelitis. 

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