不同极简指数跑鞋对髌股关节受力特征的影响

聚焦跑步时髌股关节生物力学特征,探究穿着不同极简指数(MI)跑鞋对髌股关节接触力、应力等的即刻影响。选取15名习惯后跟着地的健康男性跑者,分别穿着两种MI跑鞋(MI 86%极简跑鞋和MI 26%缓冲跑鞋),使用Vicon红外运动捕捉系统、Kistler三维测力台同步采集3.33 m/s(速度变化范围±5%)跑速下的膝、踝关节运动学和地面反作用力,通过逆向动力学等计算股四头肌肌力、髌股关节接触力、髌股关节接触面积以及髌股关节接触应力。结果显示:两种跑鞋条件下的冲击力峰值和蹬地力峰值均无明显差异。与缓冲跑鞋相比,穿着极简跑鞋跑步时,膝关节最大屈曲角度显著降低(P<0.01);髌股关节接触面积显著减小(P<0.01);膝关节伸肌峰值力矩显著下降(P<0.01);髌股关节接触力和应力峰值均显著减小(P<0.05)。研究表明,相比缓冲跑鞋,穿着极简跑鞋在未影响触地后冲击力峰值的同时,通过降低伸膝力矩大幅度减少髌股关节接触力(下降17.02%)、降低髌股关节接触应力,从而有效改善支撑期髌股关节负荷,为进一步减小髌股关节疼痛综合征风险提供可能。     

Physical activity levels in American and Japanese men from the ERA-JUMP Study and associations with metabolic syndrome

Background:Metabolic syndrome(MetS) is a global health problem.Physical activity(PA) is a known modifiable risk factor for MetS and individual MetS components.However,the role of PA could differ between sub-populations due to differences in the variability of PA and other MetS risk factors.To examine these differences,multi-country studies with standardized outcome measurement methods across cohorts are needed.Methods:Cross-sectional PA levels(total and domain specific) in healthy middle-aged(44-56 years) men in the Risk Factor Assessment among Japanese and U.S.Men in the Post-World War Ⅱ Birth Cohort(ERA-JUMP) Study(n=730;American:n=417;Japanese:n=313;from population-representative samples in Pittsburgh,Pennsylvania,USA,and Kusatsu,Shiga,Japan) were compared.The relationships between PA levels and MetS(overall and specific components) in/across the American and Japanese sub-cohorts(adjusting for age,smoking,and alcohol consumption)were also assessed using the same instruments(pedometer and validated questionnaire) to measure PA in both cohorts.Results:A total of 510 individuals provided complete data on PA(American:n=265;Japanese:n=245).The American cohort had significantly lower mean±SD steps/day(7878±3399 steps/day) vs.the Japanese cohort(9055±3797 steps/day)(p <0.001) but had significantly higher self-reported moderate-vigorous leisure PA(American:15.9(7.4-30.3) metabolic task equivalent hours per week(MET-b/week) vs.Japanese:4.0(0-11.3) METh/week,p <0.0001).In both sub-cohorts,each 1000 steps/day increase was associated with lower odds of having MetS(American:OR=0.90,95%CI:0.83-0.98;Japanese:OR=0.87,95%CI:0.79-0.95) and the individual MetS component of high waist circumference(American:OR=0.86,95%CI:0.79-0.94;Japanese:OR=0.87,95%CI:0.80-0.95).In the American cohort only,higher self-reported leisure PA(Met-b/week) was associated with lower odds of MetS and high waist circumference(OR=0.98,95%CI:0.97-0.99 for MetS and waist circumference,respectively).Conclusion:Higher total step counts/day had an important protective effect on MetS prevalence in both the Japanese and American cohorts,despite differences in PA levels and other MetS risk factors.The effect of steps/day(across all intensity levels) was much greater than domainspecific moderate-vigorous PA captured by questionnaire,suggesting the need for measurement tools that can best capture total movement when examining the effects of PA on MetS development.     

脂代谢紊乱与糖尿病及运动的干预作用

脂代谢紊乱是糖尿病极常见的一种代谢紊乱,与糖尿病的发生、发展有着密切的联系,而且两者互为因果。本文就脂代谢紊乱对糖尿病及其并发症的影响以及运动疗法对糖尿病的良性干预作用进行了综述。     

功率放大器预失真系统的TCP／IP协议栈的研究

嵌入式功率放大器预失真系统是一种当前快速发展的射频功率放大器线性化技术。在嵌入式功率放大器预失真系统的工程实现中,远程控制和实时监测功能正逐渐成为必备性能。虽然TCP／IP协议栈是实现这些功能的最具代表性和实用性的通信协议栈,但其在存储和计算能力有限的嵌入式系统中难以完全实现。针对嵌入式预失真系统的特点精简和优化TCP／IP协议,以适应嵌入式预失真系统并使其通信能力得到提高。     

Lipoproteins and cholesterol homeostasis in paediatric nephrotic syndrome patients

IntroductionThe aim of this study was to investigate lipoprotein particle distributions and the likelihood of achieving cholesterol homeostasis in the remission phase of nephrotic syndrome (NS) in paediatric patients. We hypothesized that lipoprotein particle distributions moved toward less atherogenic profile and that cholesterol homeostasis was achieved.Materials and methodsThirty-three children, 2 to 9 years old with NS were recruited. Blood sampling took place both in the acute phase and during remission. Serum low-density lipoprotein particles (LDL) and high-density lipoprotein particles (HDL) were separated using non-denaturing polyacrylamide gradient gel (3-31%) electrophoresis. Serum non-cholesterols sterols (NCSs), desmosterol, lathosterol, 7-dehydrocholesterol (7-DHC), campesterol and β-sitosterol were measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).ResultsAll patients had desirable serum HDL cholesterol concentrations during remission. The dominant lipoprotein diameters and LDL subclass distribution did not change significantly during follow-up. In contrast, HDL lipoprotein particle distribution shifted towards larger particles. The absolute concentration of desmosterol was significantly lower during remission (P = 0.023). β-sitosterol concentration markedly increased during remission (P = 0.005). Desmosterol/β-sitosterol (P < 0.001) and 7-DHC/β-sitosterol (P = 0.005) ratios significantly declined during disease remission.ConclusionsFavourable changes in the serum lipid profiles, HDL particle subclass distribution and cholesterol metabolism in paediatric patients with NS during remission took place. For the first time, we found that cholesterol homeostasis changed in favour of increased cholesterol absorption during disease remission. Nevertheless, complete cholesterol homeostasis was not achieved during disease remission.     

Verbal Short‐term Memory Performance in Pupils with Down Syndrome

Research has shown that verbal short‐term memory span is shorter in individuals with Down syndrome than in typically developing individuals of equivalent mental age, but little attention has been given to variations within or across groups. Differences in the environment and in particular educational experiences may play a part in the relative ease or difficulty with which children remember verbal material. This article explores the performance of 26 Egyptian pupils with Down syndrome and 26 Egyptian typically developing children on two verbal short‐term memory tests: digit recall and non‐word repetition tasks. The findings of the study revealed that typically developing children showed superior performance on these tasks to that of pupils with Down syndrome, whose performance was both lower and revealed a narrower range of attainment. Comparisons with the performance of children with Down syndrome in this study suggested that not only did the children with Down syndrome perform more poorly than the typically developing children, their profile also appeared worse than the results of studies of children with a similar mental age with Down syndrome carried out in western countries. The results from this study suggested that, while deficits in verbal short‐term memory in Down syndrome may well be universal, it is important to recognise that performances may vary as a consequence of culture and educational experiences. The significance of these findings is explored with reference to approaches to education and how these are conceptualised in relation to children with disabilities.     

Age-Related Changes of Serum Soluble Interleukin 9 Receptor (sIL-9Rα) in Healthy Subjects

Most cytokine receptors including interleukin (IL)-9 have soluble counterparts in body fluids. We planned to investigate the pathophysiological significance of the serum soluble IL-9 receptor (sIL-9R) level. We determined the serum sIL-9Rα chain (sIL-9Rα) levels in 96 healthy Japanese individuals to establish a control value by means of specific human sIL-9Rα ELISA, followed by a preliminary application in a patient with diarrhea positive hemolytic uremic syndrome. Age was negatively correlated with the sIL-9Rα level (Spearman r = −0.241, n = 96, p = 0.0180). The serum sIL-9Rα level showed a progressive decline to the normal adult level by the age of 30. The serum sIL-9Rα level of the patient with HUS was markedly higher than those of the age-matched control from the onset of the disease. Because of the remarkable age-dependent variability of sIL-9Rα in healthy subjects, disease-related changes, as well as therapy-dependent alterations, should be considered with caution. Thus, it is recommended that when the serum sIL-9Rα levels of patients are evaluated, the values should be compared with those of age-matched controls. The established control value will be used to discriminate between normal and the pathological conditions in our future studies.     

Uric acid as one of the important factors in multifactorial disorders--facts and controversies

With considering serum concentration of the uric acid in humans we are observing hyperuricemia and possible gout development. Many epidemiological studies have shown the relationship between the uric acid and different disorders such are obesity, metabolic syndrome, hypertension and coronary artery disease. Clinicians and investigators recognized serum uric acid concentration as very important diagnostic and prognostic factor of many multifactorial disorders. This review presented few clinical conditions which are not directly related to uric acid, but the concentrations of uric acid might have a great impact in observing, monitoring, prognosis and therapy of such disorders. Uric acid is recognized as a marker of oxidative stress. Production of the uric acid includes enzyme xanthine oxidase which is involved in producing of radical-oxigen species (ROS). As by-products ROS have a significant role in the increased vascular oxidative stress and might be involved in atherogenesis. Uric acid may inhibit endothelial function by inhibition of nitric oxide-function under conditions of oxidative stress. Down regulation of nitric oxide and induction of endothelial dysfunction might also be involved in pathogenesis of hypertension. The most important and well evidenced is possible predictive role of uric acid in predicting short-term outcome (mortality) in acute myocardial infarction (AMI) patients and stroke. Nephrolithiasis of uric acid origin is significantly more common among patients with the metabolic syndrome and obesity. On contrary to this, uric acid also acts is an "antioxidant", a free radical scavenger and a chelator of transitional metal ions which are converted to poorly reactive forms.     

Do resource bases enable social inclusion of students with Asperger syndrome in a mainstream secondary school?

This research identifies the way in which one secondary school with a resourced provision for students with Asperger syndrome promotes social inclusion for them, and the perceptions of staff members and parents on the social experience of schooling for these children. Interviews were conducted with five teachers, two learning support assistants, and the head of the resourced provision. Questionnaires were completed by eight parents of students with Asperger syndrome who attend the provision. The research found that a positive social experience of schooling was perceived by members of staff and parents due to the additional support of the resource in teaching social skills, providing a safe place and support from the learning support assistants. Some negative perceptions of social experience were also reported, which highlighted the need for educational provision for students on the autism spectrum to be considered at an individual level.