Purpose: This study aimed to explore neuromuscular fatigue and recovery profiles im individuals with intellectual disability(ID) after exhausting submaximal contraction.Methods: Ten men with ID were compared to 10 men...Purpose: This study aimed to explore neuromuscular fatigue and recovery profiles im individuals with intellectual disability(ID) after exhausting submaximal contraction.Methods: Ten men with ID were compared to 10 men without ID. The evaluation of neuromuscular function consisted in brief(3 s) isometric maximal voluntary contraction(IMVC) of the knee extension superimposed with electrical nerve stimulation before, immediately after, and during33 min after an exhausting submaximal isometric task at 15% of the IMVC. Force, voluntary activation level(VAL), potentiated twitch(Ptw), and electromyography(EMG) signals were measured during IMVC and then analyzed.Results: Individuals with ID developed lower baseline IMVC, VAL, Ptw; and RMS/M_(max) ratio(root-mean-square value normalized to the maximal peak-to-peak amplitude of the M-wave) than controls(p < 0.05). Nevertheless, the time to task failure was significantly longer in ID vs. controls(p < 0.05). The 2 groups presented similar IMVC decline and recovery kinetics after the fatiguing exercise. However. individuals with ID presented higher VAL and RMS/M_(max) ratio declines but lower Ptw decline compared to those without ID. Moreover, individuals with ID demonstrated a persistent central fatigue but faster recovery from peripheral fatigue.Conclusion: These differences in neuromuscular fatigue profiles and recovery kinetics should be acknowledged when prescribing training programs for individuals with ID.展开更多
Using Arsenazo Ⅲ as a myoplasmic calcium indicator, we have studied the calcium transients evoked by voltage-clamp depolarizing pulses in frog twitch muscle fibres which had been temporarily depolarized by 80 mmol/LK...Using Arsenazo Ⅲ as a myoplasmic calcium indicator, we have studied the calcium transients evoked by voltage-clamp depolarizing pulses in frog twitch muscle fibres which had been temporarily depolarized by 80 mmol/LK^+ in the absence or presence of myoplasmic Li^+. After the high K^+ exposure, for either a short (15 rain) or long(1 h) time, the post-K^+ calcium transients could gradually be restored to the level of the pre-K^+ ones, if the fibres were not loaded with Li^+.In contrast, the post-K^+ calcium transients of Li^+-loaded fibres could not fully recover,and were depressed in a Li^+ concentration-dependent manner.The mean amplitude of the post-K^+ responses recorded more than 3.5 h after 15 min high K^+ exposure was reduced to 56% of pre-K^+ control in the fibres which had been loaded with Li^+ in 20 mmol/L Li^+ Ringer's solution.This depression could be prevented or partially reversed by exogenous myo-inositol.More depression could be induced by 1 h high K^+ exposure, but the presence of exogenous myo-inositol could not clearly prevent the post-K^+ calcium transients from reduction.Assuming that high K^+ exposure caused a depletion of myo-inositol and probably other changes in the metabolism of inositol phospholipids in Li^+ loaded fibres,we conclude that some metabolites of phosphoinositides may play modulation roles in excitation-contraction coupling in frog twitch muscle fibres.展开更多
The dynamic properties of the assistant sounders in the black cicada are given and the twitching properties of Contraction in the sounding muscle are revealed in this paper.For the operculum, tymbal cover and joint me...The dynamic properties of the assistant sounders in the black cicada are given and the twitching properties of Contraction in the sounding muscle are revealed in this paper.For the operculum, tymbal cover and joint membrane, each of their vibration periods consists of three subgroup vibrations (SGV_(a,b,c)) corresponding to amplitude-modulation pulse trains (AMPT_(1,2,3)) in every syllable of synchro song. In comparison with the vibration at dorsum, the SGV_(a-c) have a subband with the function of regulating the tone. During calling song continuously, the pressure change inside the resonant cavity and the airspeed through the spiracles on both sides are about 7. 94—15.88 Paand 0.59—0.84 cm^3/s respectively, and they increase by about 7 and 2.6 times as the abdomen is moved. When the contraction motion of the sounding muscle comes up to the critical Sounding state, it further produces the twitching process, and drives the sounding membrane and the toning plate-membrane to produce AMPT_(1-3) and SGV_(a-c).展开更多
Background Skeletal muscle dysfunction is one of important systemic manifestations of chronic obstructive pulmonary disease （COPD） and is associated with mortality in patients with COPD, thus quantifying its strengt...Background Skeletal muscle dysfunction is one of important systemic manifestations of chronic obstructive pulmonary disease （COPD） and is associated with mortality in patients with COPD, thus quantifying its strength is of great clinical interest and of particular value. Quadriceps maximal volitional contraction （MVC） is often used for the routine measurements of this muscle＇s strength; while twitch tension （TwQ） evoked by magnetic stimulation of the femoral nerve has been employed for measurement of quadriceps strength non-volitionally. We aimed to investigate the prevalence and severity of skeletal muscle dysfunction in COPD patients by measurement of quadriceps strength with volitional and non-volitional techniques, and to probe into some methodological issues. Methods We recruited 71 COPD patients and 60 control subjects. Quadriceps strength was measured with both maximality of TwQ and MVC force. The reproducibility for TwQ and MVC was investigated using within-occasion variability from three repeated maneuvers. Results Maximal TwQ was achieved in 121 participants at a mean of 90% of the stimulator＇s maximum output. The mean maxmality of TwQ was decrease by about 44%-47% in COPD patients as compared with controls （P 〈0.05）, so was MVC. There was a significant correlation between quadriceps TwQ and MVC, and the mean ratio of TwQ/MVC was 0.29 in controls and 0.33 in patients. The coefficient of variation showed that TwQ yielded lower within-occasion variability than MVC in both groups. Conclusions Quadriceps strength is commonly and substantially impaired in patients with COPD, in terms of MVC as well as TwQ. The magnetic stimulation of the femoral nerve presents a higher reproducibility and is a better technique for measurement of quadriceps strength for the general population, especially for those who are too unwell to perform a full MVC; while it may not be applied to subjects who are over-weighted.展开更多
目的观察氨磺必利辅以无抽搐电休克治疗精神分裂症的疗效。方法我院2018年5月-2019年5月收治的74例精神分裂症患者为本次研究对象,按照是否行氨磺必利辅以无抽搐电休克治疗将所有患者分为对照组(37例:未辅以无抽搐电休克治疗)与试验组(3...目的观察氨磺必利辅以无抽搐电休克治疗精神分裂症的疗效。方法我院2018年5月-2019年5月收治的74例精神分裂症患者为本次研究对象,按照是否行氨磺必利辅以无抽搐电休克治疗将所有患者分为对照组(37例:未辅以无抽搐电休克治疗)与试验组(37例:辅以无抽搐电休克治疗),比较两组患者预后。结果试验组患者治疗3个疗程后总有效率(75.68%)、神经元特异性烯醇化酶(neuron specific enolase,NSE)、髓鞘碱性蛋白(myelin basic protein,MBP)、泌乳素等相关数值均优于对照组(P<0.05)。结论精神分裂症患者氨磺必利辅以无抽搐电休克治疗效果明显优于单一氨磺必利治疗。展开更多
In the field of natural language processing(NLP),the advancement of neural machine translation has paved the way for cross-lingual research.Yet,most studies in NLP have evaluated the proposed language models on well-r...In the field of natural language processing(NLP),the advancement of neural machine translation has paved the way for cross-lingual research.Yet,most studies in NLP have evaluated the proposed language models on well-refined datasets.We investigatewhether amachine translation approach is suitable for multilingual analysis of unrefined datasets,particularly,chat messages in Twitch.In order to address it,we collected the dataset,which included 7,066,854 and 3,365,569 chat messages from English and Korean streams,respectively.We employed several machine learning classifiers and neural networks with two different types of embedding:word-sequence embedding and the final layer of a pre-trained language model.The results of the employed models indicate that the accuracy difference between English,and English to Korean was relatively high,ranging from 3%to 12%.For Korean data(Korean,and Korean to English),it ranged from 0%to 2%.Therefore,the results imply that translation from a low-resource language(e.g.,Korean)into a high-resource language(e.g.,English)shows higher performance,in contrast to vice versa.Several implications and limitations of the presented results are also discussed.For instance,we suggest the feasibility of translation from resource-poor languages for using the tools of resource-rich languages in further analysis.展开更多
The purpose of this study was to examine the effects of a 1-h downhill running exercise on the elbow flexor muscles’neuromuscular functions.Seventeen adults(Control[CON]:n=9;Experimental[EXP]:n=8)completed this study...The purpose of this study was to examine the effects of a 1-h downhill running exercise on the elbow flexor muscles’neuromuscular functions.Seventeen adults(Control[CON]:n=9;Experimental[EXP]:n=8)completed this study.The CON rested for 30 min while the EXP performed the downhill running.Before,10 min,24 h,and 48 h after the interventions,dependent variables(knee extensor muscle soreness,elbow flexion and knee extension isometric strength,elbow flexion resting twitch and voluntary activation[VA],and the biceps surface electromyography[EMG]amplitude)were measured.Knee extensor muscle soreness was significantly greater in the EXP than the CON group following the intervention throughout the entire 48 h.This was accompanied by the greater decline in the knee extension strength in the EXP than the CON(mean±SD:-6.9±3.4%vs.1.0±3.2%,p=0.044).The elbow flexion strength,VA,and EMG amplitude were not affected by the exercise.However,the decline of the elbow flexion resting twitch was greater in the EXP than the CON(±19.6±6.3%vs.8.7±5.9%,p=0.003).Therefore,the downhill running impaired the remote elbow flexor muscles at a peripheral level.展开更多
Purpose To examine and compare the effects of three days of dynamic constant external resistance(DCER)and isokinetic(ISOK)training and subsequent detraining on thigh muscle cross-sectional area(TMCSA)and thigh lean ma...Purpose To examine and compare the effects of three days of dynamic constant external resistance(DCER)and isokinetic(ISOK)training and subsequent detraining on thigh muscle cross-sectional area(TMCSA)and thigh lean mass(TLM),ISOK peak torque(PT),DCER strength,isometric force,muscle activation,and percent voluntary activation(%VA).Methods Thirty-one apparently-healthy untrained men(mean±SD age=22.2±4.2 years;body mass=77.9±12.9 kg;height=173.9±5.4 cm)were randomly assigned to a DCER training group(n=11),ISOK training group(n=10)or control(CONT)group(n=10).Subjects visited the laboratory eight times.The first visit was a familiarization session,the second visit was a pre-training assessment,the subsequent three visits were for unilateral training of the quadriceps(if assigned to a training group),and the last three visits were the post-training assessments conducted at three days,one week,and two weeks after training ended.Results DCER strength increased from pre-to post-training assessment 1 in both limbs for the DCER group only,and remained elevated during post-training assessments 2 and 3(P<0.05).In addition,surface EMG for the biceps femoris was higher at post-training assessment 3 than at the pre-training assessment,and post-training assessments 1 and 2(P<0.05).No other training-related changes were found.Conclusion The primary finding of this study was that DCER strength of the trained and untrained limbs can be increased with three days of training.This has important implications for injury rehabilitation,where in the initial period post-injury strength gains on an injured limb can possibly be obtained with short-term contralateral resistance training.展开更多
文摘Purpose: This study aimed to explore neuromuscular fatigue and recovery profiles im individuals with intellectual disability(ID) after exhausting submaximal contraction.Methods: Ten men with ID were compared to 10 men without ID. The evaluation of neuromuscular function consisted in brief(3 s) isometric maximal voluntary contraction(IMVC) of the knee extension superimposed with electrical nerve stimulation before, immediately after, and during33 min after an exhausting submaximal isometric task at 15% of the IMVC. Force, voluntary activation level(VAL), potentiated twitch(Ptw), and electromyography(EMG) signals were measured during IMVC and then analyzed.Results: Individuals with ID developed lower baseline IMVC, VAL, Ptw; and RMS/M_(max) ratio(root-mean-square value normalized to the maximal peak-to-peak amplitude of the M-wave) than controls(p < 0.05). Nevertheless, the time to task failure was significantly longer in ID vs. controls(p < 0.05). The 2 groups presented similar IMVC decline and recovery kinetics after the fatiguing exercise. However. individuals with ID presented higher VAL and RMS/M_(max) ratio declines but lower Ptw decline compared to those without ID. Moreover, individuals with ID demonstrated a persistent central fatigue but faster recovery from peripheral fatigue.Conclusion: These differences in neuromuscular fatigue profiles and recovery kinetics should be acknowledged when prescribing training programs for individuals with ID.
基金Project supported by the National Natural Science Foundation of China.
文摘Using Arsenazo Ⅲ as a myoplasmic calcium indicator, we have studied the calcium transients evoked by voltage-clamp depolarizing pulses in frog twitch muscle fibres which had been temporarily depolarized by 80 mmol/LK^+ in the absence or presence of myoplasmic Li^+. After the high K^+ exposure, for either a short (15 rain) or long(1 h) time, the post-K^+ calcium transients could gradually be restored to the level of the pre-K^+ ones, if the fibres were not loaded with Li^+.In contrast, the post-K^+ calcium transients of Li^+-loaded fibres could not fully recover,and were depressed in a Li^+ concentration-dependent manner.The mean amplitude of the post-K^+ responses recorded more than 3.5 h after 15 min high K^+ exposure was reduced to 56% of pre-K^+ control in the fibres which had been loaded with Li^+ in 20 mmol/L Li^+ Ringer's solution.This depression could be prevented or partially reversed by exogenous myo-inositol.More depression could be induced by 1 h high K^+ exposure, but the presence of exogenous myo-inositol could not clearly prevent the post-K^+ calcium transients from reduction.Assuming that high K^+ exposure caused a depletion of myo-inositol and probably other changes in the metabolism of inositol phospholipids in Li^+ loaded fibres,we conclude that some metabolites of phosphoinositides may play modulation roles in excitation-contraction coupling in frog twitch muscle fibres.
基金Project supported by the National Natural Science Foundation of China.
文摘The dynamic properties of the assistant sounders in the black cicada are given and the twitching properties of Contraction in the sounding muscle are revealed in this paper.For the operculum, tymbal cover and joint membrane, each of their vibration periods consists of three subgroup vibrations (SGV_(a,b,c)) corresponding to amplitude-modulation pulse trains (AMPT_(1,2,3)) in every syllable of synchro song. In comparison with the vibration at dorsum, the SGV_(a-c) have a subband with the function of regulating the tone. During calling song continuously, the pressure change inside the resonant cavity and the airspeed through the spiracles on both sides are about 7. 94—15.88 Paand 0.59—0.84 cm^3/s respectively, and they increase by about 7 and 2.6 times as the abdomen is moved. When the contraction motion of the sounding muscle comes up to the critical Sounding state, it further produces the twitching process, and drives the sounding membrane and the toning plate-membrane to produce AMPT_(1-3) and SGV_(a-c).
文摘Background Skeletal muscle dysfunction is one of important systemic manifestations of chronic obstructive pulmonary disease （COPD） and is associated with mortality in patients with COPD, thus quantifying its strength is of great clinical interest and of particular value. Quadriceps maximal volitional contraction （MVC） is often used for the routine measurements of this muscle＇s strength; while twitch tension （TwQ） evoked by magnetic stimulation of the femoral nerve has been employed for measurement of quadriceps strength non-volitionally. We aimed to investigate the prevalence and severity of skeletal muscle dysfunction in COPD patients by measurement of quadriceps strength with volitional and non-volitional techniques, and to probe into some methodological issues. Methods We recruited 71 COPD patients and 60 control subjects. Quadriceps strength was measured with both maximality of TwQ and MVC force. The reproducibility for TwQ and MVC was investigated using within-occasion variability from three repeated maneuvers. Results Maximal TwQ was achieved in 121 participants at a mean of 90% of the stimulator＇s maximum output. The mean maxmality of TwQ was decrease by about 44%-47% in COPD patients as compared with controls （P 〈0.05）, so was MVC. There was a significant correlation between quadriceps TwQ and MVC, and the mean ratio of TwQ/MVC was 0.29 in controls and 0.33 in patients. The coefficient of variation showed that TwQ yielded lower within-occasion variability than MVC in both groups. Conclusions Quadriceps strength is commonly and substantially impaired in patients with COPD, in terms of MVC as well as TwQ. The magnetic stimulation of the femoral nerve presents a higher reproducibility and is a better technique for measurement of quadriceps strength for the general population, especially for those who are too unwell to perform a full MVC; while it may not be applied to subjects who are over-weighted.
文摘目的观察氨磺必利辅以无抽搐电休克治疗精神分裂症的疗效。方法我院2018年5月-2019年5月收治的74例精神分裂症患者为本次研究对象,按照是否行氨磺必利辅以无抽搐电休克治疗将所有患者分为对照组(37例:未辅以无抽搐电休克治疗)与试验组(37例:辅以无抽搐电休克治疗),比较两组患者预后。结果试验组患者治疗3个疗程后总有效率(75.68%)、神经元特异性烯醇化酶(neuron specific enolase,NSE)、髓鞘碱性蛋白(myelin basic protein,MBP)、泌乳素等相关数值均优于对照组(P<0.05)。结论精神分裂症患者氨磺必利辅以无抽搐电休克治疗效果明显优于单一氨磺必利治疗。
基金This work was supported by Institute of Information&communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(No.2021-0-00358,AI·Big data based Cyber Security Orchestration and Automated Response Technology Development).
文摘In the field of natural language processing(NLP),the advancement of neural machine translation has paved the way for cross-lingual research.Yet,most studies in NLP have evaluated the proposed language models on well-refined datasets.We investigatewhether amachine translation approach is suitable for multilingual analysis of unrefined datasets,particularly,chat messages in Twitch.In order to address it,we collected the dataset,which included 7,066,854 and 3,365,569 chat messages from English and Korean streams,respectively.We employed several machine learning classifiers and neural networks with two different types of embedding:word-sequence embedding and the final layer of a pre-trained language model.The results of the employed models indicate that the accuracy difference between English,and English to Korean was relatively high,ranging from 3%to 12%.For Korean data(Korean,and Korean to English),it ranged from 0%to 2%.Therefore,the results imply that translation from a low-resource language(e.g.,Korean)into a high-resource language(e.g.,English)shows higher performance,in contrast to vice versa.Several implications and limitations of the presented results are also discussed.For instance,we suggest the feasibility of translation from resource-poor languages for using the tools of resource-rich languages in further analysis.
文摘The purpose of this study was to examine the effects of a 1-h downhill running exercise on the elbow flexor muscles’neuromuscular functions.Seventeen adults(Control[CON]:n=9;Experimental[EXP]:n=8)completed this study.The CON rested for 30 min while the EXP performed the downhill running.Before,10 min,24 h,and 48 h after the interventions,dependent variables(knee extensor muscle soreness,elbow flexion and knee extension isometric strength,elbow flexion resting twitch and voluntary activation[VA],and the biceps surface electromyography[EMG]amplitude)were measured.Knee extensor muscle soreness was significantly greater in the EXP than the CON group following the intervention throughout the entire 48 h.This was accompanied by the greater decline in the knee extension strength in the EXP than the CON(mean±SD:-6.9±3.4%vs.1.0±3.2%,p=0.044).The elbow flexion strength,VA,and EMG amplitude were not affected by the exercise.However,the decline of the elbow flexion resting twitch was greater in the EXP than the CON(±19.6±6.3%vs.8.7±5.9%,p=0.003).Therefore,the downhill running impaired the remote elbow flexor muscles at a peripheral level.
文摘Purpose To examine and compare the effects of three days of dynamic constant external resistance(DCER)and isokinetic(ISOK)training and subsequent detraining on thigh muscle cross-sectional area(TMCSA)and thigh lean mass(TLM),ISOK peak torque(PT),DCER strength,isometric force,muscle activation,and percent voluntary activation(%VA).Methods Thirty-one apparently-healthy untrained men(mean±SD age=22.2±4.2 years;body mass=77.9±12.9 kg;height=173.9±5.4 cm)were randomly assigned to a DCER training group(n=11),ISOK training group(n=10)or control(CONT)group(n=10).Subjects visited the laboratory eight times.The first visit was a familiarization session,the second visit was a pre-training assessment,the subsequent three visits were for unilateral training of the quadriceps(if assigned to a training group),and the last three visits were the post-training assessments conducted at three days,one week,and two weeks after training ended.Results DCER strength increased from pre-to post-training assessment 1 in both limbs for the DCER group only,and remained elevated during post-training assessments 2 and 3(P<0.05).In addition,surface EMG for the biceps femoris was higher at post-training assessment 3 than at the pre-training assessment,and post-training assessments 1 and 2(P<0.05).No other training-related changes were found.Conclusion The primary finding of this study was that DCER strength of the trained and untrained limbs can be increased with three days of training.This has important implications for injury rehabilitation,where in the initial period post-injury strength gains on an injured limb can possibly be obtained with short-term contralateral resistance training.
