Effects of stimulation frequency,amplitude, and impulse width on muscle fatigue

Introduction: We investigated the effect of stimulation intensity (in percent of maximal tolerated stimulation current, mTSC), frequency, and impulse width on muscle fatigue. Methods: Using a randomized crossover design, 6 parameter combinations (80% mTSC, 80 Hz , 400 μs; 60% mTSC, 80 Hz , 400 μs; 80% mTSC, 20 Hz , 400 μs; 60% mTSC, 20 Hz , 400 μs; 80% mTSC, 80 Hz , 150 μs; 60% mTSC, 80 Hz , 150 μs) were tested in both legs of 13 athletic men (age 26 ± 2.3). The slope of the linear regression line over all tetani (FIS) and the number of tetani whose force was above 50% of the initial tetanus (FIN) were used to quantify fatigue. Results: FIS and FIN were significantly lower in high‐frequency protocols. No effects on FIS and FIN were found for intensity and impulse width. Conclusions: Stimulation frequency, but not impulse width or intensity, affected fatigue kinetics. Muscle Nerve 53 : 608–616, 2016     

抗肿瘤药物的研究:N′,N″-二螺三哌嗪类化合物的合成

In order to search for new antitumor drugs, sixteen N′, N″-dispirotripiperazine derivatives were synthesized from N′, N″-dispirotripiperazinium dichloride dihydrochloride by substitution, acylation and Mannich reaction. Six compounds were selected for preliminary pharmacological test. The result showed that five compounds possess inhibitory action against carcinoma S₃₇ in rats. The inhibitory activity of compounds Ⅵ and Ⅹ was 55.0% and. 41.9% respectively.