AIM To assess for passive expansion of sub-maximally dilated transjugular intrahepatic portosystemic shunts(TIPS) and compare outcomes with maximally dilated TIPS.METHODS Polytetrafluoroethylene covered TIPS(Viatorr) ...AIM To assess for passive expansion of sub-maximally dilated transjugular intrahepatic portosystemic shunts(TIPS) and compare outcomes with maximally dilated TIPS.METHODS Polytetrafluoroethylene covered TIPS(Viatorr) from July 2002 to December 2013 were retrospectively reviewed at two hospitals in a single institution. Two hundred and thirty patients had TIPS maximally dilated to 10 mm(m TIPS), while 43 patients who were at increased risk for hepatic encephalopathy(HE), based on clinical evaluation or low pre-TIPS portosystemic gradient(PSG), had 10 mm TIPS sub-maximally dilated to 8 mm(sm TIPS). Group characteristics(age, gender, Model for End-Stage Liver Disease score, post-TIPS PSG and clinical outcomes were compared between groups, including clinical success(ascites or varices), primary patency,primary assisted patency, and severe post-TIPS HE. A subset of fourteen patients with sm TIPS underwent follow-up computed tomography imaging after TIPS creation, and were grouped based on time of imaging(< 6 mo and > 6 mo). Change in diameter and crosssectional area were measured with 3D imaging software to evaluate for passive expansion.RESULTS Patient characteristics were similar between the sm TIPS and m TIPS groups, except for pre-TIPS portosystemic gradient, which was lower in the sm TIPS group(19.4 mm Hg ± 6.8 vs 22.4 mm Hg ± 7.1, P = 0.01). Primary patency and primary assisted patency between sm TIPS and m TIPS was not significantly different(P = 0.64 and 0.55, respectively). Four of the 55 patients(7%) with sm TIPS required TIPS reduction for severe refractory HE, while this occurred in 6 of the 218 patients(3%) with m TIPS(P = 0.12). For the 14 patients with follow-up computed tomography(CT) imaging, the median imaging follow-up was 373 d. There was an increase in median TIPS diameter, median percent diameter change, median area, and median percent area change in patients with CT follow-up greater than 6 mo after TIPS placement compared to follow-up within 6 mo(8.45 mm, 5.58%, 56.04 mm^2, and 11.48%, respec展开更多
Based on a series of recent papers, a powerful algorithm is reformulated for computing the maximal eigenpair of self-adjoint complex tridiagonal matrices. In parallel, the same problem in a particular case for computi...Based on a series of recent papers, a powerful algorithm is reformulated for computing the maximal eigenpair of self-adjoint complex tridiagonal matrices. In parallel, the same problem in a particular case for computing the sub-maximal eigenpair is also introduced. The key ideas for each critical improvement are explained. To illustrate the present algorithm and compare it with the related algorithms, more than 10 examples are included.展开更多
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
A nonlinear dynamical system is proposed as a qualitative mathematical model with the twofold aim to reasonably describe the force behavior in a fatiguing sub-maximal contraction and to be possibly employed in assessi...A nonlinear dynamical system is proposed as a qualitative mathematical model with the twofold aim to reasonably describe the force behavior in a fatiguing sub-maximal contraction and to be possibly employed in assessing muscular activation indexes. The model＇s properties are studied in terms of its equilibria and their stability properties and the existence of the fatigue equilibrium is ensured as the only system＇s attractor in the feasibility range of the parameters. Suitable mathematical indicators -- related to the dynamical properties of resilience and reactivity -- are introduced to characterize the asymptotic and the transient system＇s behavior. The practical impact of the analytical results is elucidated and a connection is established between the introduced mathematical indicators and muscle functionality indexes as rate of force development, task failure time and complete restore time. Experimental validation with handgrip force signal at high load and possible practical applications are also presented.展开更多
目的:研究采用中等强度范围一次递增负荷跑台运动过程中的主观感觉等级(RPE)和心率(HR)来预测最大耗氧量(VO2max)的可靠性。方法:体育专业大学生22名(男生10名,女生12名)在中等强度范围完成跑台递增负荷运动,测定不同运动负荷阶段的RPE...目的:研究采用中等强度范围一次递增负荷跑台运动过程中的主观感觉等级(RPE)和心率(HR)来预测最大耗氧量(VO2max)的可靠性。方法:体育专业大学生22名(男生10名,女生12名)在中等强度范围完成跑台递增负荷运动,测定不同运动负荷阶段的RPE等级、心率以及耗氧量(VO2),分别采用RPE等级9和13及其对应VO2、RPE等级9和15及其对应的VO2建立RPE等级与VO2的线性模型,然后,以此线性模型确定RPE20和RPE19所对应的VO2即为VO2max预测值;同样,在中等强度范围内,分别采用RPE等级9和13、RPE等级9和15所对应的心率与VO2建立心率与VO2之间的线性模型,然后,确定最大心率所对应的VO2即为VO2max预测值,其中,最大心率分别采用220-年龄和206.9-0.67×年龄来计算。结果:1)从预测值与测试值的比较来看,RPE9-13(RPE20)(表示线性方程采用RPE9和RPE13来建立,预测点为RPE20,下同)、RPE9-15(RPE20)、RPE9-15(RPE19)、HR9-13(220-年龄)、HR9-13(206.9-0.67×年龄)、HR9-15(220-年龄)的VO2max预测值与实际测试值均无显著差异。2)从Pearson相关来看,RPE9-13(RPE20)、RPE9-13(RPE19)、RPE9-15(RPE20)和RPE9-15(RPE19)的VO2max预测值与实际测试值之间存在一定相关,其中,RPE9-13(RPE20)和RPE9-13(RPE19)的VO2max预测值与实际测试值之间的相关系数较高(r>0.90,P<0.001);而心率VO2max预测值与实际测试值的相关系数较低(r<0.60)。3)从组内相关结果来看,RPE9-13(RPE20)、RPE9-13(RPE19)、RPE9-15(RPE20)、RPE9-15(RPE19)的VO2max预测值与实际测试值组内相关系数(intra-class correlation coefficient,ICC)均在0.80以上(P<0.01),其中,RPE9-13(RPE20)和RPE9-13(RPE19)的VO2max预测值与实际测试值之间的组内相关系数较高(ICC>0.90,P<0.001),而心率VO2max预测值与实际测试值的组内相关系数较低。4)Bland-Altman法及一致性限度(limits of agreement,95%LoA)分析结果表明,心率预测值与实际测试值的一致性限度范围较大,而RPE预测值与实测值的�展开更多
探讨急性亚极量运动诱发机体免疫抑制蛋白(Immune Suppressive Protein of Stress,ISPS)出现的最短时间。方法:以北京体育大学研究生院8名健康学生为研究对象,实施急性亚极量强度跑台运动,受试者分别于运动前、运动后24 h无菌采集静脉...探讨急性亚极量运动诱发机体免疫抑制蛋白(Immune Suppressive Protein of Stress,ISPS)出现的最短时间。方法:以北京体育大学研究生院8名健康学生为研究对象,实施急性亚极量强度跑台运动,受试者分别于运动前、运动后24 h无菌采集静脉血进行指标测定。结果发现,急性亚极量运动后24 h机体内ISPS水平升高,证实在急性运动后短至24 hISPS就能在人体内被诱导出现。结论:与运动前相比,急性亚极量运动应激24 h后,受试者血清对正常小鼠ConA诱导的淋巴细胞增殖具有明显的抑制作用,是血清中ISPS蛋白水平升高引起。展开更多
文摘AIM To assess for passive expansion of sub-maximally dilated transjugular intrahepatic portosystemic shunts(TIPS) and compare outcomes with maximally dilated TIPS.METHODS Polytetrafluoroethylene covered TIPS(Viatorr) from July 2002 to December 2013 were retrospectively reviewed at two hospitals in a single institution. Two hundred and thirty patients had TIPS maximally dilated to 10 mm(m TIPS), while 43 patients who were at increased risk for hepatic encephalopathy(HE), based on clinical evaluation or low pre-TIPS portosystemic gradient(PSG), had 10 mm TIPS sub-maximally dilated to 8 mm(sm TIPS). Group characteristics(age, gender, Model for End-Stage Liver Disease score, post-TIPS PSG and clinical outcomes were compared between groups, including clinical success(ascites or varices), primary patency,primary assisted patency, and severe post-TIPS HE. A subset of fourteen patients with sm TIPS underwent follow-up computed tomography imaging after TIPS creation, and were grouped based on time of imaging(< 6 mo and > 6 mo). Change in diameter and crosssectional area were measured with 3D imaging software to evaluate for passive expansion.RESULTS Patient characteristics were similar between the sm TIPS and m TIPS groups, except for pre-TIPS portosystemic gradient, which was lower in the sm TIPS group(19.4 mm Hg ± 6.8 vs 22.4 mm Hg ± 7.1, P = 0.01). Primary patency and primary assisted patency between sm TIPS and m TIPS was not significantly different(P = 0.64 and 0.55, respectively). Four of the 55 patients(7%) with sm TIPS required TIPS reduction for severe refractory HE, while this occurred in 6 of the 218 patients(3%) with m TIPS(P = 0.12). For the 14 patients with follow-up computed tomography(CT) imaging, the median imaging follow-up was 373 d. There was an increase in median TIPS diameter, median percent diameter change, median area, and median percent area change in patients with CT follow-up greater than 6 mo after TIPS placement compared to follow-up within 6 mo(8.45 mm, 5.58%, 56.04 mm^2, and 11.48%, respec
基金supported in part the National Natural Science Foundation of China (Grant No. 11771046)the Project from the Ministry of Education in Chinathe Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Based on a series of recent papers, a powerful algorithm is reformulated for computing the maximal eigenpair of self-adjoint complex tridiagonal matrices. In parallel, the same problem in a particular case for computing the sub-maximal eigenpair is also introduced. The key ideas for each critical improvement are explained. To illustrate the present algorithm and compare it with the related algorithms, more than 10 examples are included.
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.
文摘A nonlinear dynamical system is proposed as a qualitative mathematical model with the twofold aim to reasonably describe the force behavior in a fatiguing sub-maximal contraction and to be possibly employed in assessing muscular activation indexes. The model＇s properties are studied in terms of its equilibria and their stability properties and the existence of the fatigue equilibrium is ensured as the only system＇s attractor in the feasibility range of the parameters. Suitable mathematical indicators -- related to the dynamical properties of resilience and reactivity -- are introduced to characterize the asymptotic and the transient system＇s behavior. The practical impact of the analytical results is elucidated and a connection is established between the introduced mathematical indicators and muscle functionality indexes as rate of force development, task failure time and complete restore time. Experimental validation with handgrip force signal at high load and possible practical applications are also presented.
文摘目的:研究采用中等强度范围一次递增负荷跑台运动过程中的主观感觉等级(RPE)和心率(HR)来预测最大耗氧量(VO2max)的可靠性。方法:体育专业大学生22名(男生10名,女生12名)在中等强度范围完成跑台递增负荷运动,测定不同运动负荷阶段的RPE等级、心率以及耗氧量(VO2),分别采用RPE等级9和13及其对应VO2、RPE等级9和15及其对应的VO2建立RPE等级与VO2的线性模型,然后,以此线性模型确定RPE20和RPE19所对应的VO2即为VO2max预测值;同样,在中等强度范围内,分别采用RPE等级9和13、RPE等级9和15所对应的心率与VO2建立心率与VO2之间的线性模型,然后,确定最大心率所对应的VO2即为VO2max预测值,其中,最大心率分别采用220-年龄和206.9-0.67×年龄来计算。结果:1)从预测值与测试值的比较来看,RPE9-13(RPE20)(表示线性方程采用RPE9和RPE13来建立,预测点为RPE20,下同)、RPE9-15(RPE20)、RPE9-15(RPE19)、HR9-13(220-年龄)、HR9-13(206.9-0.67×年龄)、HR9-15(220-年龄)的VO2max预测值与实际测试值均无显著差异。2)从Pearson相关来看,RPE9-13(RPE20)、RPE9-13(RPE19)、RPE9-15(RPE20)和RPE9-15(RPE19)的VO2max预测值与实际测试值之间存在一定相关,其中,RPE9-13(RPE20)和RPE9-13(RPE19)的VO2max预测值与实际测试值之间的相关系数较高(r>0.90,P<0.001);而心率VO2max预测值与实际测试值的相关系数较低(r<0.60)。3)从组内相关结果来看,RPE9-13(RPE20)、RPE9-13(RPE19)、RPE9-15(RPE20)、RPE9-15(RPE19)的VO2max预测值与实际测试值组内相关系数(intra-class correlation coefficient,ICC)均在0.80以上(P<0.01),其中,RPE9-13(RPE20)和RPE9-13(RPE19)的VO2max预测值与实际测试值之间的组内相关系数较高(ICC>0.90,P<0.001),而心率VO2max预测值与实际测试值的组内相关系数较低。4)Bland-Altman法及一致性限度(limits of agreement,95%LoA)分析结果表明,心率预测值与实际测试值的一致性限度范围较大,而RPE预测值与实测值的�
文摘探讨急性亚极量运动诱发机体免疫抑制蛋白(Immune Suppressive Protein of Stress,ISPS)出现的最短时间。方法:以北京体育大学研究生院8名健康学生为研究对象,实施急性亚极量强度跑台运动,受试者分别于运动前、运动后24 h无菌采集静脉血进行指标测定。结果发现,急性亚极量运动后24 h机体内ISPS水平升高,证实在急性运动后短至24 hISPS就能在人体内被诱导出现。结论:与运动前相比,急性亚极量运动应激24 h后,受试者血清对正常小鼠ConA诱导的淋巴细胞增殖具有明显的抑制作用,是血清中ISPS蛋白水平升高引起。
