Introduction: The Six-Minute Walk Test (6MWT) is an inexpensive method to objectively evaluate physical capacity or limitation and stratify prognosis in patients with Heart Failure (HF). Since the clinical p...Introduction: The Six-Minute Walk Test (6MWT) is an inexpensive method to objectively evaluate physical capacity or limitation and stratify prognosis in patients with Heart Failure (HF). Since the clinical perception of symptoms may be adapted or compromised, regular evaluation from medical interviews often fails to determine functional classification. This study aimed to assess the correlation between New York Heart Association Functional Class (NYHA-FC) and the distance walked in the 6MWT. Methods: We conducted a cross-sectional observational study that included patients with HF with reduced ejection fraction followed up at an outpatient service of a teaching hospital, from August 2018 to April 2019. Patients in NYHA-FC I, II, or III were included. We compared NYHA-FC subjectively obtained during the consultation with the 6MWT performed after medical consultation, and the correlation between these two parameters was assessed. Results: The study included 70 patients with HF, 41 (58.6%) of whom were female. The mean age was 61.2 ± 12.7 years. The most prevalent etiologies were dilated idiopathic cardiomyopathy (35.7%) followed by ischemic cardiomyopathy (25.7%). The mean ejection fraction was 34.1% ± 9.8%. The average distance walked in the 6MWT by NYHA-FC I patients was 437.8 ± 95.8 meters, NYHA-FC II 360.1 ± 96.4, and NYHA-FC III 248.4 ± 98.3. Functional class measured by the 6MWT was different than that estimated by NYHA-FC in 34 patients (48.6%), 23 (32.9%) for a higher functional class and 11 (15.7%) for a lower one (p = 0.07). Pearson’s correlation coefficient between NYHA-FC and the 6MWT was -0.55. Conclusion: There was a moderate correlation between the subjective NYHA-FC and the 6MWT. The 6MWT revealed a different classification from NYHA-FC in almost half of the patients. Among those who presented discrepancies between methods, 6MWT reclassification towards a higher functional class was more common.展开更多
BACKGROUND Patients with cirrhosis are at risk of cirrhotic cardiomyopathy,with resulting cardiac dysfunction and exercise limitations.Six minute walking test(6MWT)assesses functional status and predicts morbidity and...BACKGROUND Patients with cirrhosis are at risk of cirrhotic cardiomyopathy,with resulting cardiac dysfunction and exercise limitations.Six minute walking test(6MWT)assesses functional status and predicts morbidity and mortality in cardiopulmonary diseases.AIM To determine if it associates with mortality by analyzing 6MWT performance in patients with liver cirrhosis.METHODS A cohort of 106 cirrhotic patients was evaluated in the outpatient setting with echocardiogram and 6MWT and follow up for one year to document hepatic decompensation and mortality.The distance in meters was recorded at the end of 6 min(6MWD).RESULTS This cohort had a mean age of 51 years and 56%male;patients were staged as Child A in 21.7%,B 66%and C 12.3%.Walk distance inversely correlated with Child scores,and was significantly reduced as Child stages progresses.Patients who died(10.4%)showed shorter mean 6MWD(P=0.006).Low 6MWD was an independent predictor of mortality(P=0.01).CONCLUSION 6MWT is a noninvasive inexpensive test whose result is related to Child scores and mortality.It is useful to identify patients with liver cirrhosis at high risk of mortality for closer monitoring and potential early intervention.展开更多
In the metropolises of China, the metro plays an increasingly important role in commuting because of its efficiency, affordability, and cleanliness. This paper attempts to explore the relationship between walking acce...In the metropolises of China, the metro plays an increasingly important role in commuting because of its efficiency, affordability, and cleanliness. This paper attempts to explore the relationship between walking access distance to metro stations and the demographic characteristics of passengers, such as age, monthly income, travel frequency, gender, and travel purpose, as well as the influence of the urban context. Nanjing Metro Line 2 is selected as the case study. By using different methods such as a questionnaire survey, spatial decay function, analysis of covariance(ANOVA), network analysis of routes, and K-means cluster analysis, it is suggested that demographic characteristics have a significant impact on the pedestrian walking distance, with the exception of gender. Furthermore, the paper finds a spatial decay effect in walking access distance, the decay rate of which, however, varies across stations. Terminal stations have a larger pedestrian catchment area than in regular and exchange stations. Moreover, the passengers of Nanjing Metro Line 2 can be classified into six groups according to their demographic characteristics, among which education and occupation are vital indicators in determining their willingness to walk to the stations. Middle-class passengers have a higher dependence on the metro and tend to walk longer than other groups do. This study provides an important reference for planners and transport sectors to optimize land-use and transport infrastructures.展开更多
Use of the six-minute walk test has been proposed as a prognostic marker in liver cirrhosis.In the Letter to the Editor presented here,the authors highlight some important points,which were raised after the article wa...Use of the six-minute walk test has been proposed as a prognostic marker in liver cirrhosis.In the Letter to the Editor presented here,the authors highlight some important points,which were raised after the article was published in the November issue of the World Journal of Hepatology.展开更多
Objectives To analyze the six-minute walk test （6MWT） and gas exchange of 5 heart transplantation patients and to approach the variation tendency of exercise tolerance, oxygen uptake （ VO2 ） and heart rate chronot...Objectives To analyze the six-minute walk test （6MWT） and gas exchange of 5 heart transplantation patients and to approach the variation tendency of exercise tolerance, oxygen uptake （ VO2 ） and heart rate chronotropic response. Methods 5 cases of heart transplantation patients （ age 25 - 52 years） were undertaken 6MWT 6 - 30 months after operation, synchronizing gas exchanging parameters were measured by wireless portable remote sensing K4B^2 gas analyzer, 51 normal controls were compared. Results The six-minute walk distance （6MWD） of 5 patients were （592.6 ± 26.7 ） m （558 - 625 ） m, the ascending tendency during exercise was slower, the maximum heart rates were 80% ± 6% of age-predicting maximal heart rate, lower than normal control （86%） ; the end point VO2/kg were （21.8 ± 1.4 ） mL/min · kg （ 19. 94 - 23.60） mL/min · kg. Conclusions The 6WMD and VO2 of 5 patients reached normal range, but the heart rate chronotropic response and VO2 ascending tendency were slower than those of normal controls.展开更多
Objectives To assess the relationship between peak oxygen consumption （PVO2） and the ambulation distance in six-minute walk test （6MWT）among the healthy subjects. Methods The 51 healthy subjects were recruited for...Objectives To assess the relationship between peak oxygen consumption （PVO2） and the ambulation distance in six-minute walk test （6MWT）among the healthy subjects. Methods The 51 healthy subjects were recruited for the six-minute walk test. Data of pulmonary gas exchange breath by breath, such as VO2 , VCO2 were real-time measured with wireless remote sensing K4B2, so to study the relationship between peak oxygen uptake and the ambulation distance. Results It was noticed that there was a positive linear correlation between the ambulation distance and PVO2 （ r =0. 619, P 〈0. 001 ） in six-minute walk test. The regression equation was set up （ VO2/kg =0. 05D -6. 331, P 〈 0. 001 ）. PVO2 〉 PVCO2 ,R 〈 1 were found,which suggested that 6MWT was a test below anaerobic threshold. Conclusions There was a closely positive linear correlation between the ambulation distance and PVO2, which is safety, convenient and valuable for the evaluation of cardiopulmonary function and the treatment of cardiopulmonary rehabilitation.展开更多
Background: Venous thromboembolism (VTE) is among the leading causes of hospital-related disability-adjusted life years lost. We aimed to determine the prevalence and determinants of functional capacity impairment six...Background: Venous thromboembolism (VTE) is among the leading causes of hospital-related disability-adjusted life years lost. We aimed to determine the prevalence and determinants of functional capacity impairment six to twelve months after an acute VTE event. Methods: This was a cross-sectional study conducted between January and April 2021 in two referral hospitals of Yaoundé, including consenting adult patients admitted to these hospitals six to twelve months ago for VTE. We excluded dead patients and those with any comorbidity or symptoms limiting physical activity. The functional outcome was assessed with the six-minute walk test. Functional capacity impairment was defined as walking distance lower than the expected value. Results: We included 27 cases in this study with a mean age of 53.2 ± 14.4 years. The prevalence of functional capacity impairment was 29.6% (95% CI: 14.8 - 48.1). Factors associated with poor functional outcome were obesity (OR: 59.5;95% CI: 4.6 - 767.2;p - 207.4;p = 0.017), massive PE (OR: 30;95% CI: 2.5 - 354;p = 0.004), and poor adherence to treatment (OR: 30.3;95% CI: 2.5 - 333.3;p = 0.004). Conclusion: Functional capacity impairment is common in the medium-term after VTE and factors associated with this poor outcome are obesity, the severity of the VTE, and poor adherence to treatment.展开更多
作为现代主义文学先驱的艾米丽·狄金森,一生传世的作品有一千七百多首。她的大量作品是歌颂自然之美的。其中一首动人的诗作:"A Bird Came down from the Walk"体现了她深谙自然界蕴含的灵动之美。本文以朱光潜的文艺心...作为现代主义文学先驱的艾米丽·狄金森,一生传世的作品有一千七百多首。她的大量作品是歌颂自然之美的。其中一首动人的诗作:"A Bird Came down from the Walk"体现了她深谙自然界蕴含的灵动之美。本文以朱光潜的文艺心理学中的审美距离理论为依据。通过两个角度分析了这首诗作:一是审美者与审美对象要保持一定的心理距离。二是审美者与审美对象要达到物我同一的境界。结论:在文学作品创作,尤其是诗歌创作中,若即若离是创造美感的最佳距离。展开更多
We analyze the localization of quantum walks on a one-dimensional finite graph using vector-distance. We first vectorize the probability distribution of a quantum walker in each node. Then we compute out the probabili...We analyze the localization of quantum walks on a one-dimensional finite graph using vector-distance. We first vectorize the probability distribution of a quantum walker in each node. Then we compute out the probability distribution vectors of quantum walks in infinite and finite graphs in the presence of static disorder respectively, and get the distance between these two vectors. We find that when the steps taken are small and the boundary condition is tight, the localization between the infinite and finite cases is greatly different. However, the difference is negligible when the steps taken are large or the boundary condition is loose. It means quantum walks on a one-dimensional finite graph may also suffer from localization in the presence of static disorder. Our approach and results can be generalized to analyze the localization of quantum walks in higher-dimensional cases.展开更多
Aging induces decrease of locomotor capacity and its decrease is associated with an increased risk of falls. Several lines of evidence indicate that both change in muscle power and aerobic fitness are causative. Mobil...Aging induces decrease of locomotor capacity and its decrease is associated with an increased risk of falls. Several lines of evidence indicate that both change in muscle power and aerobic fitness are causative. Mobility tests are usually based on a maximal exercise stress test;however, this test is often difficult and sometimes frightening to older persons. Therefore, the objective of this study was to examine age and gender differences in 3-min walk distance test (3WDT), and time of chair-rising test (CRT) of functional mobility. 153 men and 159 women aged from 20 to 78 years were recruited as subjects of the present study. The body composition measured the height, body mass (BM), body mass index (BMI), lean tissue mass (LTM), and waist circumference (WC). The Functional mobility tests measured the peak oxygen uptake (VO2peak), 3WDT, leg extension strength (LES), and times of CRT. Both in men and women, height and BMI, WC decreased and increased, respectively, with age. Height, BM, LTM, WC in men are higher than in women. We found no correlation between ages and 3WDT in women and a significant, negative correlation in men. All parameters of fitness performance were negatively correlated with age. Both in men and women, all parameters of fitness performance were positively correlated with sex. Both in men and women, VO2peak, 3WDT, and LES decreased with age. All parameters of fitness performance in men are higher than in women. Both in men and women were observed for the correlation between 3WDT and VO2peak, LES and CRT respectively. Although as the correlation coefficient between 3WTD and VO2peak, LES and CRT were low (r = 0.28 - 0.38), an error may occur, this study shows that 3WDT and CRT test can be a feasible method of providing the information for muscle power and aerobic fitness, possibly avoiding the need for a maximal stress test.展开更多
In this paper, we analytically discuss the scaling properties of the average square end-to-end distance <R2> for anisotropic random walk in D-dimensional space ( D ≥ 2), and the returning probability Pn(ro) for...In this paper, we analytically discuss the scaling properties of the average square end-to-end distance <R2> for anisotropic random walk in D-dimensional space ( D ≥ 2), and the returning probability Pn(ro) for the walker into a certain neighborhood of the origin. We will not only give the calculating formula for <R2> and Pn (ro), but also point out that if there is a symmetric axis for the distribution of the probability density of a single step displacement, we always obtain <R2⊥n> ～ n, where ⊥ refers to the projections of the displacement perpendicular to each symmetric axes of the walk; in D-dimensional space with D symmetric axes perpendicular to each other, we always have <R2n> ～ n and the random walk will be like a purely random motion; if the number of inter-perpendicular symmetric axis is smaller than the dimensions of the space, we must have <R2n> ～ n2 for very large n and the walk will be like a ballistic motion. It is worth while to point out that unlike the isotropic random walk in one and two dimensions, which is certain to return into the neighborhood of the origin, generally there is only a nonzero probability for the anisotropic random walker in two dimensions to return to the neighborhood.展开更多
目的比较4种手术方法治疗重度慢性阻塞性肺疾病伴肺大疱的临床疗效。方法回顾性选取2019年1月—2021年12月广元市第一人民医院心胸外科79例重度慢性阻塞性肺疾病伴肺大疱手术患者,根据切口类型不同为开胸组(n=12)、小切口组(n=15)、单孔...目的比较4种手术方法治疗重度慢性阻塞性肺疾病伴肺大疱的临床疗效。方法回顾性选取2019年1月—2021年12月广元市第一人民医院心胸外科79例重度慢性阻塞性肺疾病伴肺大疱手术患者,根据切口类型不同为开胸组(n=12)、小切口组(n=15)、单孔组(n=23)、两孔组(n=29),4组患者均施行单侧肺减容、肺大疱切除术。统计患者一般资料、手术时间、术中出血量、重症加强护理病房(intensive care unit,ICU)时间、术后总引流量、胸管留置时间、住院时间、不良事件发生率、肺功能、血气指标、6 min步行距离并进行对比分析。结果79例患者无围术期死亡,术后2个月开胸组因严重的肺部感染合并呼吸衰竭死亡1例。4组患者手术时间、死亡发生率比较,差异无统计学意义(P>0.05)。单孔和两孔胸腔镜组术中出血量、ICU时间、术后总引流量、胸管留置时间、住院时间、不良事件发生率较小切口及开胸手术比较,差异有统计学意义(P<0.05)。4组患者术后7 d第1秒用力呼气容积占预计值百分比(63.55±25.15)、(61.69±24.53)、(64.02±24.22)、(64.20±30.09)较术前比较(44.48±12.55)、(42.01±13.15)、(43.89±13.21)、(42.59±14.76)均明显改善,差异有统计学意义(P<0.05)。结论单孔和两孔明显优于小切口及开胸手术,术后患者呼吸困难及生活质量明显改善。是一种创伤小、有效、可靠和安全的手术技术,可以让患者在几年内获得更好的生活质量,更适合肺功能差的患者。展开更多
目的 分析模拟仿真功能评估训练系统(BTE Primus RS)对踝关节创伤性关节炎患者三维步态参数的影响。方法 收集2019年12月至2021年12月宝鸡市中医医院康复医学科收治的96例踝关节创伤性关节炎患者,根据电脑数字表法进行随机分组,对照组4...目的 分析模拟仿真功能评估训练系统(BTE Primus RS)对踝关节创伤性关节炎患者三维步态参数的影响。方法 收集2019年12月至2021年12月宝鸡市中医医院康复医学科收治的96例踝关节创伤性关节炎患者,根据电脑数字表法进行随机分组,对照组48例予以常规训练,观察组48例予以BTE Primus RS训练,比较2组患者的干预效果、关节活动度、三维步态参数及无痛步行距离。结果 训练后,观察组患者的总优良率是93.8%,高于对照组的79.2%(P<0.05);观察组患者踝关节的外翻、背伸、外展、跖屈及内收角度均高于对照组(P<0.05);观察组患者患足廓清地面的最大距离、步长均长于对照组,同时步频与步速也高于对照组(P<0.05);观察组中无痛步行200~500 m及>500 m的患者数高于对照组,而无痛步行距离<200 m的患者数则低于对照组(P<0.05)。结论 BTE Primus RS训练在踝关节创伤性关节炎患者中的应用效果显著,有助于提升其干预效果,改善关节活动度与三维步态参数,并且促进无痛步行距离延长。展开更多
文摘Introduction: The Six-Minute Walk Test (6MWT) is an inexpensive method to objectively evaluate physical capacity or limitation and stratify prognosis in patients with Heart Failure (HF). Since the clinical perception of symptoms may be adapted or compromised, regular evaluation from medical interviews often fails to determine functional classification. This study aimed to assess the correlation between New York Heart Association Functional Class (NYHA-FC) and the distance walked in the 6MWT. Methods: We conducted a cross-sectional observational study that included patients with HF with reduced ejection fraction followed up at an outpatient service of a teaching hospital, from August 2018 to April 2019. Patients in NYHA-FC I, II, or III were included. We compared NYHA-FC subjectively obtained during the consultation with the 6MWT performed after medical consultation, and the correlation between these two parameters was assessed. Results: The study included 70 patients with HF, 41 (58.6%) of whom were female. The mean age was 61.2 ± 12.7 years. The most prevalent etiologies were dilated idiopathic cardiomyopathy (35.7%) followed by ischemic cardiomyopathy (25.7%). The mean ejection fraction was 34.1% ± 9.8%. The average distance walked in the 6MWT by NYHA-FC I patients was 437.8 ± 95.8 meters, NYHA-FC II 360.1 ± 96.4, and NYHA-FC III 248.4 ± 98.3. Functional class measured by the 6MWT was different than that estimated by NYHA-FC in 34 patients (48.6%), 23 (32.9%) for a higher functional class and 11 (15.7%) for a lower one (p = 0.07). Pearson’s correlation coefficient between NYHA-FC and the 6MWT was -0.55. Conclusion: There was a moderate correlation between the subjective NYHA-FC and the 6MWT. The 6MWT revealed a different classification from NYHA-FC in almost half of the patients. Among those who presented discrepancies between methods, 6MWT reclassification towards a higher functional class was more common.
文摘BACKGROUND Patients with cirrhosis are at risk of cirrhotic cardiomyopathy,with resulting cardiac dysfunction and exercise limitations.Six minute walking test(6MWT)assesses functional status and predicts morbidity and mortality in cardiopulmonary diseases.AIM To determine if it associates with mortality by analyzing 6MWT performance in patients with liver cirrhosis.METHODS A cohort of 106 cirrhotic patients was evaluated in the outpatient setting with echocardiogram and 6MWT and follow up for one year to document hepatic decompensation and mortality.The distance in meters was recorded at the end of 6 min(6MWD).RESULTS This cohort had a mean age of 51 years and 56%male;patients were staged as Child A in 21.7%,B 66%and C 12.3%.Walk distance inversely correlated with Child scores,and was significantly reduced as Child stages progresses.Patients who died(10.4%)showed shorter mean 6MWD(P=0.006).Low 6MWD was an independent predictor of mortality(P=0.01).CONCLUSION 6MWT is a noninvasive inexpensive test whose result is related to Child scores and mortality.It is useful to identify patients with liver cirrhosis at high risk of mortality for closer monitoring and potential early intervention.
基金Under the auspices of National Nature Science Foundation of China(No.41701180)
文摘In the metropolises of China, the metro plays an increasingly important role in commuting because of its efficiency, affordability, and cleanliness. This paper attempts to explore the relationship between walking access distance to metro stations and the demographic characteristics of passengers, such as age, monthly income, travel frequency, gender, and travel purpose, as well as the influence of the urban context. Nanjing Metro Line 2 is selected as the case study. By using different methods such as a questionnaire survey, spatial decay function, analysis of covariance(ANOVA), network analysis of routes, and K-means cluster analysis, it is suggested that demographic characteristics have a significant impact on the pedestrian walking distance, with the exception of gender. Furthermore, the paper finds a spatial decay effect in walking access distance, the decay rate of which, however, varies across stations. Terminal stations have a larger pedestrian catchment area than in regular and exchange stations. Moreover, the passengers of Nanjing Metro Line 2 can be classified into six groups according to their demographic characteristics, among which education and occupation are vital indicators in determining their willingness to walk to the stations. Middle-class passengers have a higher dependence on the metro and tend to walk longer than other groups do. This study provides an important reference for planners and transport sectors to optimize land-use and transport infrastructures.
文摘Use of the six-minute walk test has been proposed as a prognostic marker in liver cirrhosis.In the Letter to the Editor presented here,the authors highlight some important points,which were raised after the article was published in the November issue of the World Journal of Hepatology.
文摘Objectives To analyze the six-minute walk test （6MWT） and gas exchange of 5 heart transplantation patients and to approach the variation tendency of exercise tolerance, oxygen uptake （ VO2 ） and heart rate chronotropic response. Methods 5 cases of heart transplantation patients （ age 25 - 52 years） were undertaken 6MWT 6 - 30 months after operation, synchronizing gas exchanging parameters were measured by wireless portable remote sensing K4B^2 gas analyzer, 51 normal controls were compared. Results The six-minute walk distance （6MWD） of 5 patients were （592.6 ± 26.7 ） m （558 - 625 ） m, the ascending tendency during exercise was slower, the maximum heart rates were 80% ± 6% of age-predicting maximal heart rate, lower than normal control （86%） ; the end point VO2/kg were （21.8 ± 1.4 ） mL/min · kg （ 19. 94 - 23.60） mL/min · kg. Conclusions The 6WMD and VO2 of 5 patients reached normal range, but the heart rate chronotropic response and VO2 ascending tendency were slower than those of normal controls.
文摘Objectives To assess the relationship between peak oxygen consumption （PVO2） and the ambulation distance in six-minute walk test （6MWT）among the healthy subjects. Methods The 51 healthy subjects were recruited for the six-minute walk test. Data of pulmonary gas exchange breath by breath, such as VO2 , VCO2 were real-time measured with wireless remote sensing K4B2, so to study the relationship between peak oxygen uptake and the ambulation distance. Results It was noticed that there was a positive linear correlation between the ambulation distance and PVO2 （ r =0. 619, P 〈0. 001 ） in six-minute walk test. The regression equation was set up （ VO2/kg =0. 05D -6. 331, P 〈 0. 001 ）. PVO2 〉 PVCO2 ,R 〈 1 were found,which suggested that 6MWT was a test below anaerobic threshold. Conclusions There was a closely positive linear correlation between the ambulation distance and PVO2, which is safety, convenient and valuable for the evaluation of cardiopulmonary function and the treatment of cardiopulmonary rehabilitation.
文摘Background: Venous thromboembolism (VTE) is among the leading causes of hospital-related disability-adjusted life years lost. We aimed to determine the prevalence and determinants of functional capacity impairment six to twelve months after an acute VTE event. Methods: This was a cross-sectional study conducted between January and April 2021 in two referral hospitals of Yaoundé, including consenting adult patients admitted to these hospitals six to twelve months ago for VTE. We excluded dead patients and those with any comorbidity or symptoms limiting physical activity. The functional outcome was assessed with the six-minute walk test. Functional capacity impairment was defined as walking distance lower than the expected value. Results: We included 27 cases in this study with a mean age of 53.2 ± 14.4 years. The prevalence of functional capacity impairment was 29.6% (95% CI: 14.8 - 48.1). Factors associated with poor functional outcome were obesity (OR: 59.5;95% CI: 4.6 - 767.2;p - 207.4;p = 0.017), massive PE (OR: 30;95% CI: 2.5 - 354;p = 0.004), and poor adherence to treatment (OR: 30.3;95% CI: 2.5 - 333.3;p = 0.004). Conclusion: Functional capacity impairment is common in the medium-term after VTE and factors associated with this poor outcome are obesity, the severity of the VTE, and poor adherence to treatment.
文摘作为现代主义文学先驱的艾米丽·狄金森,一生传世的作品有一千七百多首。她的大量作品是歌颂自然之美的。其中一首动人的诗作:"A Bird Came down from the Walk"体现了她深谙自然界蕴含的灵动之美。本文以朱光潜的文艺心理学中的审美距离理论为依据。通过两个角度分析了这首诗作:一是审美者与审美对象要保持一定的心理距离。二是审美者与审美对象要达到物我同一的境界。结论:在文学作品创作,尤其是诗歌创作中,若即若离是创造美感的最佳距离。
基金Project supported by the National Natural Science Foundation of China(Grant No.11174370)
文摘We analyze the localization of quantum walks on a one-dimensional finite graph using vector-distance. We first vectorize the probability distribution of a quantum walker in each node. Then we compute out the probability distribution vectors of quantum walks in infinite and finite graphs in the presence of static disorder respectively, and get the distance between these two vectors. We find that when the steps taken are small and the boundary condition is tight, the localization between the infinite and finite cases is greatly different. However, the difference is negligible when the steps taken are large or the boundary condition is loose. It means quantum walks on a one-dimensional finite graph may also suffer from localization in the presence of static disorder. Our approach and results can be generalized to analyze the localization of quantum walks in higher-dimensional cases.
文摘Aging induces decrease of locomotor capacity and its decrease is associated with an increased risk of falls. Several lines of evidence indicate that both change in muscle power and aerobic fitness are causative. Mobility tests are usually based on a maximal exercise stress test;however, this test is often difficult and sometimes frightening to older persons. Therefore, the objective of this study was to examine age and gender differences in 3-min walk distance test (3WDT), and time of chair-rising test (CRT) of functional mobility. 153 men and 159 women aged from 20 to 78 years were recruited as subjects of the present study. The body composition measured the height, body mass (BM), body mass index (BMI), lean tissue mass (LTM), and waist circumference (WC). The Functional mobility tests measured the peak oxygen uptake (VO2peak), 3WDT, leg extension strength (LES), and times of CRT. Both in men and women, height and BMI, WC decreased and increased, respectively, with age. Height, BM, LTM, WC in men are higher than in women. We found no correlation between ages and 3WDT in women and a significant, negative correlation in men. All parameters of fitness performance were negatively correlated with age. Both in men and women, all parameters of fitness performance were positively correlated with sex. Both in men and women, VO2peak, 3WDT, and LES decreased with age. All parameters of fitness performance in men are higher than in women. Both in men and women were observed for the correlation between 3WDT and VO2peak, LES and CRT respectively. Although as the correlation coefficient between 3WTD and VO2peak, LES and CRT were low (r = 0.28 - 0.38), an error may occur, this study shows that 3WDT and CRT test can be a feasible method of providing the information for muscle power and aerobic fitness, possibly avoiding the need for a maximal stress test.
文摘In this paper, we analytically discuss the scaling properties of the average square end-to-end distance <R2> for anisotropic random walk in D-dimensional space ( D ≥ 2), and the returning probability Pn(ro) for the walker into a certain neighborhood of the origin. We will not only give the calculating formula for <R2> and Pn (ro), but also point out that if there is a symmetric axis for the distribution of the probability density of a single step displacement, we always obtain <R2⊥n> ～ n, where ⊥ refers to the projections of the displacement perpendicular to each symmetric axes of the walk; in D-dimensional space with D symmetric axes perpendicular to each other, we always have <R2n> ～ n and the random walk will be like a purely random motion; if the number of inter-perpendicular symmetric axis is smaller than the dimensions of the space, we must have <R2n> ～ n2 for very large n and the walk will be like a ballistic motion. It is worth while to point out that unlike the isotropic random walk in one and two dimensions, which is certain to return into the neighborhood of the origin, generally there is only a nonzero probability for the anisotropic random walker in two dimensions to return to the neighborhood.
文摘目的比较4种手术方法治疗重度慢性阻塞性肺疾病伴肺大疱的临床疗效。方法回顾性选取2019年1月—2021年12月广元市第一人民医院心胸外科79例重度慢性阻塞性肺疾病伴肺大疱手术患者,根据切口类型不同为开胸组(n=12)、小切口组(n=15)、单孔组(n=23)、两孔组(n=29),4组患者均施行单侧肺减容、肺大疱切除术。统计患者一般资料、手术时间、术中出血量、重症加强护理病房(intensive care unit,ICU)时间、术后总引流量、胸管留置时间、住院时间、不良事件发生率、肺功能、血气指标、6 min步行距离并进行对比分析。结果79例患者无围术期死亡,术后2个月开胸组因严重的肺部感染合并呼吸衰竭死亡1例。4组患者手术时间、死亡发生率比较,差异无统计学意义(P>0.05)。单孔和两孔胸腔镜组术中出血量、ICU时间、术后总引流量、胸管留置时间、住院时间、不良事件发生率较小切口及开胸手术比较,差异有统计学意义(P<0.05)。4组患者术后7 d第1秒用力呼气容积占预计值百分比(63.55±25.15)、(61.69±24.53)、(64.02±24.22)、(64.20±30.09)较术前比较(44.48±12.55)、(42.01±13.15)、(43.89±13.21)、(42.59±14.76)均明显改善,差异有统计学意义(P<0.05)。结论单孔和两孔明显优于小切口及开胸手术,术后患者呼吸困难及生活质量明显改善。是一种创伤小、有效、可靠和安全的手术技术,可以让患者在几年内获得更好的生活质量,更适合肺功能差的患者。
文摘目的 分析模拟仿真功能评估训练系统(BTE Primus RS)对踝关节创伤性关节炎患者三维步态参数的影响。方法 收集2019年12月至2021年12月宝鸡市中医医院康复医学科收治的96例踝关节创伤性关节炎患者,根据电脑数字表法进行随机分组,对照组48例予以常规训练,观察组48例予以BTE Primus RS训练,比较2组患者的干预效果、关节活动度、三维步态参数及无痛步行距离。结果 训练后,观察组患者的总优良率是93.8%,高于对照组的79.2%(P<0.05);观察组患者踝关节的外翻、背伸、外展、跖屈及内收角度均高于对照组(P<0.05);观察组患者患足廓清地面的最大距离、步长均长于对照组,同时步频与步速也高于对照组(P<0.05);观察组中无痛步行200~500 m及>500 m的患者数高于对照组,而无痛步行距离<200 m的患者数则低于对照组(P<0.05)。结论 BTE Primus RS训练在踝关节创伤性关节炎患者中的应用效果显著,有助于提升其干预效果,改善关节活动度与三维步态参数,并且促进无痛步行距离延长。
