Background: Since the minimum grip span of a standard Smedley hand dynamometer is 4 cm, the handgrip strength (HGS) value at a less than 4 cm grip span has not been reported. Objective: The present study examined the ...Background: Since the minimum grip span of a standard Smedley hand dynamometer is 4 cm, the handgrip strength (HGS) value at a less than 4 cm grip span has not been reported. Objective: The present study examined the impact of grip span on handgrip strength (HGS) in young children using a dynamometer ranging from 2 to 4.5 cm of grip span. Methods: A total of 93 (39 girls and 54 boys) children were recruited from a local kindergarten with the cooperation of their parents. Each participant performed one test trial and then five maximal trials using different grip spans (2.0, 3.0, 3.5, 4.0, and 4.5 cm) in random order and allowing a 1-minute rest between measures. Results: There was a statistically significant difference in HGS depending on which grip span was used, χ<sup>2</sup>(4) = 211.5 (p Conclusion: Our results recommended that the target grip span for measuring maximal HGS in young children is about 4 cm (4 ± 0.5 cm).展开更多
Background: Although handgrip strength is a biomarker for morbidity/mor-tality, there is lack of evidence on the effects of resistance training on handgrip strength in healthy adults of all ages. Objective: The aim of...Background: Although handgrip strength is a biomarker for morbidity/mor-tality, there is lack of evidence on the effects of resistance training on handgrip strength in healthy adults of all ages. Objective: The aim of this systematic review was to assess the impact of resistance training on handgrip strength in healthy adults. Methods: Five databases/search engines were searched. Studies comparing different types of resistance exercise interventions versus a non-exercised control group on handgrip strength were included. The available data did not allow us to conduct the pre-planned meta-analyses;therefore, only descriptive statistics were performed to summarize the data. Results: Twenty studies (17 randomized and three non-randomized controlled trials) were included, most of which were conducted in older adults. Twelve studies reported no significant difference in the change in handgrip strength between the resistance training and control groups. Two studies showed increases in handgrip strength in the resistance training group compared with the control group. Other studies included results for multi-training groups or left/right hands and found increasing handgrip strength compared to controls, but only in one training group or one hand. Overall, the randomized and non-ran-domized clinical trials presented moderate risk of bias. Conclusions: Due to the lack of low risk-of-bias randomized controlled trials of young and middle-aged adults, different training protocols, and small sample sizes, the existing evidence appears insufficient to support resistance training for increasing handgrip strength in healthy adults. Future studies may seek to discern the optimal way to develop and employ resistance training to improve hand-grip strength.展开更多
AIM:To evaluate the influence of taking low-dose aspirin for 4 wk on small intestinal complications and to examine the preventive effect of rebamipide.METHODS:This study was conducted as a single-center,randomized,dou...AIM:To evaluate the influence of taking low-dose aspirin for 4 wk on small intestinal complications and to examine the preventive effect of rebamipide.METHODS:This study was conducted as a single-center,randomized,double-blind,cross-over,placebo-controlled study.Eleven healthy male subjects were enrolled.Each subject underwent video capsule endos-copy after 1 and 4 wk of taking aspirin and omepra-zole,along with either rebamipide or placebo therapy.The primary endpoint was to evaluate small bowel damage in healthy subjects before and after taking low-dose aspirin for 4 wk.RESULTS:The number of subjects with mucosal breaks(defined as multiple erosions and/or ulcers)were 1 at 1 wk and 1 at 4 wk on the jejunum,and 6 at 1 wk(P = 0.0061)and 7 at 4 wk on the ileum(P =0.0019).Rebamipide significantly prevented mucosal breaks on the ileum compared with the placebo group(P = 0.0173 at 1 wk and P = 0.0266 at 4 wk).CONCLUSION:Longer-term,low-dose aspirin adminis-tration induced damage in the small bowel.Rebamipide prevented this damage,and may be a candidate drug for treating aspirin-induced small bowel complications.展开更多
Two-dimensional（2D） numerical simulations of thermochemical nonequilibrium inductively coupled plasma（ICP） flows inside a 10-kW inductively coupled plasma wind tunnel（ICPWT） were carried out with nitrogen as the...Two-dimensional（2D） numerical simulations of thermochemical nonequilibrium inductively coupled plasma（ICP） flows inside a 10-kW inductively coupled plasma wind tunnel（ICPWT） were carried out with nitrogen as the working gas.Compressible axisymmetric NavierStokes（N-S） equations coupled with magnetic vector potential equations were solved.A fourtemperature model including an improved electron-vibration relaxation time was used to model the internal energy exchange between electron and heavy particles.The third-order accuracy electron transport properties（3rd AETP） were applied to the simulations.A hybrid chemical kinetic model was adopted to model the chemical nonequilibrium process.The flow characteristics such as thermal nonequilibrium,inductive discharge,effects of Lorentz force were made clear through the present study.It was clarified that the thermal nonequilibrium model played an important role in properly predicting the temperature field.The prediction accuracy can be improved by applying the 3rd AETP to the simulation for this ICPWT.展开更多
The purpose of this study was to determine whether the training responses observed with low-load resistance exercise to volitional fatigue translates into significant muscle hypertrophy, and compare that response to h...The purpose of this study was to determine whether the training responses observed with low-load resistance exercise to volitional fatigue translates into significant muscle hypertrophy, and compare that response to high-load resistance training. Nine previously untrained men (aged 25 [SD 3] years at the beginning of the study, standing height 1.73 [SD 0.07] m, body mass 68.9 [SD 8.1] kg) completed 6-week of high load-resistance training (HL-RT) (75% of one repeti-tion maximal [1RM], 3-sets, 3x/wk) followed by 12 months of detraining. Following this, subjects completed 6 weeks of low load-resistance training (LL-RT) to volitional fatigue (30% 1 RM, 4 sets, 3x/wk). Increases (p 0.05) in magnetic resonance imaging-measured triceps brachii and pectorals major muscle cross-sectional areas were similar for both HL-RT (11.9% and 17.6%, respectively) and LL-RT (9.8% and 21.1%, respectively). In addition, both groups increased (p 0.05) 1RM and maximal elbow extension strength following training;however, the percent increases in 1RM (8.6% vs. 21.0%) and elbow extension strength (6.5% vs. 13.9%) were significantly (p 0.05) lower with LL-RT. Both protocols elicited similar increases in muscle cross-sectional area, however differences were observed in strength. An explanation of the smaller relative increases in strength may be due to the fact that detraining after HL-RT did not cause strength values to return to baseline levels thereby producing smaller changes in strength. In addition, the results may also suggest that the consistent practice of lifting a heavy load is necessary to maximize gains in muscular strength of the trained movement. These results demonstrate that significant muscle hypertrophy can occur without high-load resistance training and suggests that the focus on percentage of external load as the important deciding factor on muscle hypertrophy is too simplistic and inappropriate.展开更多
Dual-energy X-ray absorptiometry (DXA) is an attractive method for evaluating sarcopenia, age-related loss of skeletal muscle mass and function, using appendicular lean tissue (aLT) mass for criteria of diagnosis, alt...Dual-energy X-ray absorptiometry (DXA) is an attractive method for evaluating sarcopenia, age-related loss of skeletal muscle mass and function, using appendicular lean tissue (aLT) mass for criteria of diagnosis, although minimal radiation is exposed. Skeletal muscle (SM) mass can be estimated by using ultrasound-measured muscle thickness (MTH). However, the association between these two methods is unclear. To examine the relationship between DXA-derived aLT mass and total body SM mass estimated by ultrasound, thirty-six healthy adults (18 men and 18 women) aged 19 - 65 years participated in this study. Ultrasound-measured muscle thickness was used to estimate the total SM mass. DXA was used to estimate whole body and regional body composition, and aLT mass was considered equivalent to the sum of lean tissue in both the right and left arms and legs. Total SM mass (26.3 ± 4.4 kg for men and 15.7 ± 2.6 kg for women) estimated by ultrasound was similar to DXA-estimated aLT mass (24.5 ± 3.8 kg for men and 15.7 ± 2.7 kg for women). There was a strong correlation between DXA-measured aLT mass and total SM mass estimated by ultrasound in men (r = 0.927, n = 18) and women (r = 0.931, n = 18) as well as overall sample (r = 0.975, n = 36). The ratio of total SM mass to aLT mass was 1.07 for men and 1.00 for women. These results suggest that DXA-derived aLT mass can be accurately predicted from ultrasound estimated total SM mass, although the predicted value may underestimate in men (approximately 7% at the group level).展开更多
Numerical simulations of 10 kW and 110 kW inductively coupled plasma （ICP） wind tunnels were carried out to study physical properties of the flow inside the ICP torch and vacuum chamber with air as tile working gas....Numerical simulations of 10 kW and 110 kW inductively coupled plasma （ICP） wind tunnels were carried out to study physical properties of the flow inside the ICP torch and vacuum chamber with air as tile working gas. Two-dimensional compressible axisymmetric Navier- Stokes （N-S） equations that took into account 11 species and 49 chemical reactions of air, were solved. A heat source model was used to describe the heating phenomenon instead of solving the electromagnetic equations. In the vacuum chamber, a four-temperature model was coupled with N-S equations. Numerical results for tile 10 kW ICP wind tunnel are presented and discussed in detail as a representative case. It was found that the plasma flow in the vacuum chamber tended to be in local thermoehemical equilibrium. To study the influence of operation conditions on the flow field, simulations were carried out for different chamber pressures and/or input powers. The computational results for the above two ICP wind tunnels were compared with corresponding experimental data. The computational and experimental results agree well, therefore the flow fields of ICP wind tunnels can be clearly understood.展开更多
The purpose of this study was to determine the specific muscles that may contribute to sprint performance. Eleven female 100-m sprinters and nine non-sprinters volunteered. Thigh muscle volume (MV) was measured using ...The purpose of this study was to determine the specific muscles that may contribute to sprint performance. Eleven female 100-m sprinters and nine non-sprinters volunteered. Thigh muscle volume (MV) was measured using magnetic resonance imaging (MRI) images obtained from the spina iliaca anterior-superior to below the distal end of the femur. The MV of the adductors, quadriceps and hamstrings was calculated. Evidence for the null/alternative hypothesis was provided thorough the calculation of Bayes Factors (BF10). Differences represented as median δ(95% credible interval). Absolute MVs in the quadriceps [1.287 (0.315, 2.39), BF10: 14.3], hamstrings [3.032 (1.886, 4.482), BF10: 9487.4] and adductors [3.22 (1.994, 4.654), BF10: 23,360.2] were greater in sprinters than in non-sprinters. This was also observed when MV was normalized to body mass (cm3/kg). Absolute and relative MVs in the adductor longus, the adductor brevis, the adductor magnus, pectineus, and gracilis were also greater in the sprinters. However, percentage of component adductor relative to total adductors MV appeared similar between the two groups. There was no evidence for a correlation between sprint time and quadriceps, hamstrings and adductors MV relative to body mass. Within the adductors, there was evidence for a correlation between sprint time and adductor brevis MV relative to body mass [r = −0.652, BF10: 3.028, δ−0.548 (−0.870, 0.040)]. Although the credible interval was wide, our results suggest that the adductor brevis may contribute to sprint running performance in female sprinters. This may be related, in part, to supporting the flexion and medial rotation of the thigh.展开更多
文摘Background: Since the minimum grip span of a standard Smedley hand dynamometer is 4 cm, the handgrip strength (HGS) value at a less than 4 cm grip span has not been reported. Objective: The present study examined the impact of grip span on handgrip strength (HGS) in young children using a dynamometer ranging from 2 to 4.5 cm of grip span. Methods: A total of 93 (39 girls and 54 boys) children were recruited from a local kindergarten with the cooperation of their parents. Each participant performed one test trial and then five maximal trials using different grip spans (2.0, 3.0, 3.5, 4.0, and 4.5 cm) in random order and allowing a 1-minute rest between measures. Results: There was a statistically significant difference in HGS depending on which grip span was used, χ<sup>2</sup>(4) = 211.5 (p Conclusion: Our results recommended that the target grip span for measuring maximal HGS in young children is about 4 cm (4 ± 0.5 cm).
文摘Background: Although handgrip strength is a biomarker for morbidity/mor-tality, there is lack of evidence on the effects of resistance training on handgrip strength in healthy adults of all ages. Objective: The aim of this systematic review was to assess the impact of resistance training on handgrip strength in healthy adults. Methods: Five databases/search engines were searched. Studies comparing different types of resistance exercise interventions versus a non-exercised control group on handgrip strength were included. The available data did not allow us to conduct the pre-planned meta-analyses;therefore, only descriptive statistics were performed to summarize the data. Results: Twenty studies (17 randomized and three non-randomized controlled trials) were included, most of which were conducted in older adults. Twelve studies reported no significant difference in the change in handgrip strength between the resistance training and control groups. Two studies showed increases in handgrip strength in the resistance training group compared with the control group. Other studies included results for multi-training groups or left/right hands and found increasing handgrip strength compared to controls, but only in one training group or one hand. Overall, the randomized and non-ran-domized clinical trials presented moderate risk of bias. Conclusions: Due to the lack of low risk-of-bias randomized controlled trials of young and middle-aged adults, different training protocols, and small sample sizes, the existing evidence appears insufficient to support resistance training for increasing handgrip strength in healthy adults. Future studies may seek to discern the optimal way to develop and employ resistance training to improve hand-grip strength.
基金Supported by The Department of General Medicine and Gastroenterology,Oita University
文摘AIM:To evaluate the influence of taking low-dose aspirin for 4 wk on small intestinal complications and to examine the preventive effect of rebamipide.METHODS:This study was conducted as a single-center,randomized,double-blind,cross-over,placebo-controlled study.Eleven healthy male subjects were enrolled.Each subject underwent video capsule endos-copy after 1 and 4 wk of taking aspirin and omepra-zole,along with either rebamipide or placebo therapy.The primary endpoint was to evaluate small bowel damage in healthy subjects before and after taking low-dose aspirin for 4 wk.RESULTS:The number of subjects with mucosal breaks(defined as multiple erosions and/or ulcers)were 1 at 1 wk and 1 at 4 wk on the jejunum,and 6 at 1 wk(P = 0.0061)and 7 at 4 wk on the ileum(P =0.0019).Rebamipide significantly prevented mucosal breaks on the ileum compared with the placebo group(P = 0.0173 at 1 wk and P = 0.0266 at 4 wk).CONCLUSION:Longer-term,low-dose aspirin adminis-tration induced damage in the small bowel.Rebamipide prevented this damage,and may be a candidate drug for treating aspirin-induced small bowel complications.
基金supported by Grant-in-Aid for Scientific Research(No.23560954)sponsored by the Japan Society for the Promotion of Science
文摘Two-dimensional（2D） numerical simulations of thermochemical nonequilibrium inductively coupled plasma（ICP） flows inside a 10-kW inductively coupled plasma wind tunnel（ICPWT） were carried out with nitrogen as the working gas.Compressible axisymmetric NavierStokes（N-S） equations coupled with magnetic vector potential equations were solved.A fourtemperature model including an improved electron-vibration relaxation time was used to model the internal energy exchange between electron and heavy particles.The third-order accuracy electron transport properties（3rd AETP） were applied to the simulations.A hybrid chemical kinetic model was adopted to model the chemical nonequilibrium process.The flow characteristics such as thermal nonequilibrium,inductive discharge,effects of Lorentz force were made clear through the present study.It was clarified that the thermal nonequilibrium model played an important role in properly predicting the temperature field.The prediction accuracy can be improved by applying the 3rd AETP to the simulation for this ICPWT.
文摘The purpose of this study was to determine whether the training responses observed with low-load resistance exercise to volitional fatigue translates into significant muscle hypertrophy, and compare that response to high-load resistance training. Nine previously untrained men (aged 25 [SD 3] years at the beginning of the study, standing height 1.73 [SD 0.07] m, body mass 68.9 [SD 8.1] kg) completed 6-week of high load-resistance training (HL-RT) (75% of one repeti-tion maximal [1RM], 3-sets, 3x/wk) followed by 12 months of detraining. Following this, subjects completed 6 weeks of low load-resistance training (LL-RT) to volitional fatigue (30% 1 RM, 4 sets, 3x/wk). Increases (p 0.05) in magnetic resonance imaging-measured triceps brachii and pectorals major muscle cross-sectional areas were similar for both HL-RT (11.9% and 17.6%, respectively) and LL-RT (9.8% and 21.1%, respectively). In addition, both groups increased (p 0.05) 1RM and maximal elbow extension strength following training;however, the percent increases in 1RM (8.6% vs. 21.0%) and elbow extension strength (6.5% vs. 13.9%) were significantly (p 0.05) lower with LL-RT. Both protocols elicited similar increases in muscle cross-sectional area, however differences were observed in strength. An explanation of the smaller relative increases in strength may be due to the fact that detraining after HL-RT did not cause strength values to return to baseline levels thereby producing smaller changes in strength. In addition, the results may also suggest that the consistent practice of lifting a heavy load is necessary to maximize gains in muscular strength of the trained movement. These results demonstrate that significant muscle hypertrophy can occur without high-load resistance training and suggests that the focus on percentage of external load as the important deciding factor on muscle hypertrophy is too simplistic and inappropriate.
文摘Dual-energy X-ray absorptiometry (DXA) is an attractive method for evaluating sarcopenia, age-related loss of skeletal muscle mass and function, using appendicular lean tissue (aLT) mass for criteria of diagnosis, although minimal radiation is exposed. Skeletal muscle (SM) mass can be estimated by using ultrasound-measured muscle thickness (MTH). However, the association between these two methods is unclear. To examine the relationship between DXA-derived aLT mass and total body SM mass estimated by ultrasound, thirty-six healthy adults (18 men and 18 women) aged 19 - 65 years participated in this study. Ultrasound-measured muscle thickness was used to estimate the total SM mass. DXA was used to estimate whole body and regional body composition, and aLT mass was considered equivalent to the sum of lean tissue in both the right and left arms and legs. Total SM mass (26.3 ± 4.4 kg for men and 15.7 ± 2.6 kg for women) estimated by ultrasound was similar to DXA-estimated aLT mass (24.5 ± 3.8 kg for men and 15.7 ± 2.7 kg for women). There was a strong correlation between DXA-measured aLT mass and total SM mass estimated by ultrasound in men (r = 0.927, n = 18) and women (r = 0.931, n = 18) as well as overall sample (r = 0.975, n = 36). The ratio of total SM mass to aLT mass was 1.07 for men and 1.00 for women. These results suggest that DXA-derived aLT mass can be accurately predicted from ultrasound estimated total SM mass, although the predicted value may underestimate in men (approximately 7% at the group level).
基金supported by Grant-in-Aid for Scientific Research(No.23560954)sponsored by the Japan Society for the Promotion of Science
文摘Numerical simulations of 10 kW and 110 kW inductively coupled plasma （ICP） wind tunnels were carried out to study physical properties of the flow inside the ICP torch and vacuum chamber with air as tile working gas. Two-dimensional compressible axisymmetric Navier- Stokes （N-S） equations that took into account 11 species and 49 chemical reactions of air, were solved. A heat source model was used to describe the heating phenomenon instead of solving the electromagnetic equations. In the vacuum chamber, a four-temperature model was coupled with N-S equations. Numerical results for tile 10 kW ICP wind tunnel are presented and discussed in detail as a representative case. It was found that the plasma flow in the vacuum chamber tended to be in local thermoehemical equilibrium. To study the influence of operation conditions on the flow field, simulations were carried out for different chamber pressures and/or input powers. The computational results for the above two ICP wind tunnels were compared with corresponding experimental data. The computational and experimental results agree well, therefore the flow fields of ICP wind tunnels can be clearly understood.
文摘The purpose of this study was to determine the specific muscles that may contribute to sprint performance. Eleven female 100-m sprinters and nine non-sprinters volunteered. Thigh muscle volume (MV) was measured using magnetic resonance imaging (MRI) images obtained from the spina iliaca anterior-superior to below the distal end of the femur. The MV of the adductors, quadriceps and hamstrings was calculated. Evidence for the null/alternative hypothesis was provided thorough the calculation of Bayes Factors (BF10). Differences represented as median δ(95% credible interval). Absolute MVs in the quadriceps [1.287 (0.315, 2.39), BF10: 14.3], hamstrings [3.032 (1.886, 4.482), BF10: 9487.4] and adductors [3.22 (1.994, 4.654), BF10: 23,360.2] were greater in sprinters than in non-sprinters. This was also observed when MV was normalized to body mass (cm3/kg). Absolute and relative MVs in the adductor longus, the adductor brevis, the adductor magnus, pectineus, and gracilis were also greater in the sprinters. However, percentage of component adductor relative to total adductors MV appeared similar between the two groups. There was no evidence for a correlation between sprint time and quadriceps, hamstrings and adductors MV relative to body mass. Within the adductors, there was evidence for a correlation between sprint time and adductor brevis MV relative to body mass [r = −0.652, BF10: 3.028, δ−0.548 (−0.870, 0.040)]. Although the credible interval was wide, our results suggest that the adductor brevis may contribute to sprint running performance in female sprinters. This may be related, in part, to supporting the flexion and medial rotation of the thigh.
