High Rate Discharge Studies of LI/SO2 Batteries

A battery composed of twelve lithium/sulfur dioxide D size cells in series is forced discharged at 21 amperes. This current is established by the proposed use of the battery and represented a discharge condition which might produce venting. Discharge of the battery into voltage reversal results not only in cells venting but also in the violent rupture of at least one cell

Determining the influence and effects of manufacturing variables on sulfur dioxide cells

A survey of the Li/SO2 manufacturing community was conducted to determine where variability exists in processing. The upper and lower limits of these processing variables might, by themselves or by interacting with other variables, influence safety, performance, and reliability. A number of important variables were identified and a comprehensive design experiment is being proposed to make the proper determinations

Effect of phosphate and temperature on force exerted by white muscle fibres from dogfish.

Effects of Pi (inorganic phosphate) are relevant to the in vivo function of muscle because Pi is one of the products of ATP hydrolysis by actomyosin and by the sarcoplasmic reticulum Ca pump. We have measured the Pi sensitivity of force produced by permeabilized muscle fibres from dogfish (Scyliorhinus canicula) and rabbit. The activation conditions for dogfish fibres were crucial: fibres activated from the relaxed state at 5, 12, and 20°C were sensitive to Pi, whereas fibres activated from rigor at 12°C were insensitive to Pi in the range 5-25 mmol l. Rabbit fibres activated from rigor were sensitive to Pi. Pi sensitivity of force produced by dogfish fibres activated from the relaxed state was greater below normal body temperature (12°C for dogfish) in agreement with what is known for other species. The force-temperature relationship for dogfish fibres (intact and permeabilized fibres activated from relaxed) showed that at 12°C, normal body temperature, the force was near to its maximum value

Progestin Receptor-Mediated Reduction of Anxiety-Like Behavior in Male Rats

BACKGROUND: It is well known progesterone can have anxiolytic-like effects in animals in a number of different behavioral testing paradigms. Although progesterone is known to influence physiology and behavior by binding to classical intracellular progestin receptors, progesterone's anxiety reducing effects have solely been attributed to its rapid non-genomic effects at the GABA A receptor. This modulation occurs following the bioconversion of progesterone to allopregnanolone. Seemingly paradoxical results from some studies suggested that the function of progesterone to reduce anxiety-like behavior may not be entirely clear; therefore, we hypothesized that progesterone might also act upon progestin receptors to regulate anxiety. METHODOLOGY/PRINCIPAL FINDINGS: To test this, we examined the anxiolytic-like effects of progesterone in male rats using the elevated plus maze, a validated test of anxiety, and the light/dark chamber in the presence or absence of a progestin receptor antagonist, RU 486. Here we present evidence suggesting that the anxiolytic-like effects of progesterone in male rats can be mediated, in part, by progestin receptors, as these effects are blocked by prior treatment with a progestin receptor antagonist. CONCLUSION/SIGNIFICANCE: This indicates that progesterone can act upon progestin receptors to regulate anxiety-like behavior in the male rat brain

Beta-alanine supplementation improves isometric, but not isotonic or isokinetic strength endurance in recreationally strength-trained young men

Background: β-alanine (BA) supplementation may be ergogenic during high intensity exercise, primarily due to the buffering of hydrogen cations, although the effects of beta-alanine supplementationon strength endurance are equivocal. Aim: To determine the effects of 4 weeks of beta-alanine supplementation on skeletal muscle endurance using a battery of performance tests. Methods: This study employed a parallel group, repeated measures, randomised, double-blinded and placebo controlled design. Twenty recreationally strength-trained healthy males completed tests of isotonic strength endurance (repeated bench and leg press), along with tests of isometric and isokinetic endurance conducted using an isokinetic dynamometer. Tests were performed before and after a 4 week intervention, comprising an intake of 6.4g.day-1 10 of BA (n = 9) or placebo (maltodextrin, n = 11). Results: Time-to-exhaustion during the isometric endurance test improved by ~17% in the BA group (p 0.1) were shown for any of the performance variables in the isokinetic test (peak torque, fatigue index, total work) nor for the total number of repetitions performed in the isotonic endurance tests (leg or bench press). Conclusions: Four weeks of BA supplementation (6.4 g.day-1 15 ) improved isometric, but not isokinetic or isotonic endurance performance

Effects of ovine corticotropin-releasing hormone on adrenocorticotropin secretion in the absence of glucocorticoid feedback inhibition in man

We studied 1) the nature of the plasma ACTH response to ovine CRH (oCRH) in the absence of normal glucocorticoid negative feedback inhibition and 2) the cause of the diminished circadian peak in plasma ACTH in normal men the morning after 3–30 μg/kg BW doses of oCRH. Placebo or oCRH (3 μg/kg BW, iv) was administered as iv injections to five normal men given metyrapone to produce acute glucocorticoid deficiency. Four studies were performed: 1) placebo oCRH plus placebo hydrocortisone (HC), 2) oCRH plus placebo HC, 3) placebo oCRH plus HC, and 4) oCRH plus HC. HC was given as a variable rate iv infusion to mimic the plasma cortisol response to the same dose of oCRH in normal men. Plasma cortisol levels rose only slightly after oCRH, indicating nearly complete blockade of cortisol biosynthesis. Plasma cortisol levels during the HC infusion were similar to those in normal men given 3 μg/kg oCRH. There was an exaggerated rise in both the first and second peaks of the plasma ACTH response to oCRH in the metyrapone-treated men. HC infusion did not alter the plasma ACTH response during the first 60 min after oCRH, but markedly attenuated the response thereafter; however, it did not affect the timing of the second peak. This inhibitory effect continued for up to 11 h, which was 2–3 h longer than the period that plasma cortisol levels were increased. Thus, cortisol secreted in response to ACTH released by oCRH modulates, after about a 60-min delay, the continuing release of ACTH. Despite the greater oCRH-induced release of pituitary ACTH in the metyrapone-treated men, the magnitude of their next morning’s circadian plasma ACTH peak was similar to that after they received placebo oCRH. Thus, depletion of pituitary ACTH did not appear to explain the diminished circadian peak. Its magnitude was reduced by the combination of oCRH and HC, but not by HC alone. Administration of oCRH, alone or in combination with HC, delayed the onset of the circadian rise, while oCRH, HC, or the combination thereof delayed the time of the circadian peak. Thus, it appears that both the glucocorticoid response to oCRH and direct or indirect effect(s) of oCRH are required to produce these two phenomena