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A network thermodynamic method is presented which utilizes SPICE2, a computer program for simulating nonlinear electrical circuits, to model and simulate a number of nonlinear, dynamic physiological systems. Ordinary circuit diagrams are presented along with bond graph representations to facilitate translation into the simulation language. Examples discussed are a compartmental model of sodium flow in frog skin, coupled salt and volume flow in kidney proximal tubule and a cancer chemotherapeutic agent's permeation and metabolism in a cancer cell. 相似文献
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Abstract This study examined the perceptions of certified public accountants concerning deterrents to participation in Web‐based continuing professional education. A survey instrument was mailed to a random sample of the Georgia Society of Certified Public Accountants’ membership, and 444 usable surveys were returned. Four broad dimensions of deterrence to participation in Web‐based education were identified through factor analysis. The two most influential deterrents were Concerns about Electronically Mediated Communication and Concerns about the Quality of Course Offerings. The other two were Concerns about Access to Technology‐Associated Resources and Concerns about the Availability of Necessary Personal Resources. The vast majority of respondents reported that they had access to the technology and that they perceived themselves as having the personal characteristics necessary for participation in Web‐based education activities. However, the proportion of respondents using Web‐based education for continuing professional learning in 1998 was minimal. 相似文献
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Effects of exercise intensity on salivary antimicrobial proteins and markers of stress in active men 总被引：2，自引：0，他引：2
In the present study, we assessed the effects of exercise intensity on salivary immunoglobulin A (s-IgA) and salivary lysozyme (s-Lys) and examined how these responses were associated with salivary markers of adrenal activation. Using a randomized design, 10 healthy active men participated in three experimental cycling trials: 50% maximal oxygen uptake (VO2max), 75%VO2max, and an incremental test to exhaustion. The durations of the trials were the same as for a preliminary incremental test to exhaustion (22.3 min, sx = 0.8). Timed, unstimulated saliva samples were collected before exercise, immediately after exercise, and 1 h after exercise. In the incremental exhaustion trial, the secretion rates of both s-IgA and s-Lys were increased. An increase in s-Lys secretion rate was also observed at 75%VO2max. No significant changes in saliva flow rate were observed in any trial. Cycling at 75%VOmax and to exhaustion increased the secretion of alpha-amylase and chromogranin A immediately after exercise; higher cortisol values at 75%VO2max and in the incremental exhaustion trial compared with 50%VO2max were observed 1 h immediately after exercise only. These findings suggest that short-duration, high-intensity exercise increases the secretion rate of s-IgA and s-Lys despite no change in the saliva flow rate. These effects appear to be associated with changes in sympathetic activity and not the hypothalamic - pituitary - adrenal axis. 相似文献
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