Carnosine in health and disease     

Guilherme Giannini Artioli  Craig Sale  Rebecca Louise Jones 《European Journal of Sport Science》2019,19(1):30-39

Abstract

Carnosine was originally discovered in skeletal muscle, where it exists in larger amounts than in other tissues. The majority of research into the physiological roles of carnosine have been conducted on skeletal muscle. Given this and the potential for muscle carnosine content to be increased with supplementation, there is now a large body of research examining the ergogenic effects (or otherwise) of carnosine. More recent research, however, points towards a potential for carnosine to exert a wider range of physiological effects in other tissues, including the brain, heart, pancreas, kidney and cancer cells. Taken together, this is suggestive of a potential for carnosine to have therapeutic benefits in health and disease, although this is by no means without complication. Herein, we will provide a review of the current literature relating to the potential therapeutic effects of carnosine in health and disease.  相似文献   

Optimizing recovery to support multi-evening cycling competition performance     

Normand A Richard  Michael S Koehle 《European Journal of Sport Science》2019,19(6):811-823

Road criterium and track bicycle racing occur at high speeds, demand repeated high power outputs, last 10–90?min, and offer little chance for recovery after the event. Consecutive evenings of criterium and track racing are respectively known as speed-week or six-day events and take place in evening hours over the course of a week. Given the schedule and timing of these competitions, return to homeostasis can be compromised. No recommendations exist on how to optimize recovery for cyclists participating in these types of repeated evening competitions. Criterium and track cyclists spend considerable time, near and above the individual lactate threshold and therefore mostly utilize carbohydrate as their chief energy substrate. Henceforth, pre – and post-race nutrition and hydration is examined and recommendations are brought forward for carbohydrate, protein, and fluid intake. As evening high-intensity exercise perturbs sleep, strategies to optimize sleep are discussed and recommendations for an optimal sleep environment are given. Active recovery is examined, and the benefits of a short duration low intensity exercise reviewed. Passive recovery methods such as compression garments and cold water immersion are recommended, while evidence for massage, pneumatic compression devices, and neuromuscular electrical stimulation is still lacking. Optimizing recovery strategies will facilitate a return to the resting state following strenuous night competition.  相似文献   

Body composition differences by age and playing standard in male rugby union and rugby league: A systematic review and meta-analysis     

Tom Geeson-Brown  Ben Jones  Kevin Till  Sarah Chantler  Kevin Deighton 《Journal of sports sciences》2020,38(19):2161-2176

ABSTRACT

This systematic review and meta-analysis aimed to determine differences in body compositionn between playing standard and age in male rugby union and rugby league athletes. The MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines for design, implementation, and reporting were followed. Studies were required to be in male rugby union or league and have body composition as the primary or secondary outcome. Data was required to be presented separately for positional groups and body composition presented as whole-body. A systematic search was performed in PubMed, Cochrane Library, MEDLINE, SPORTDiscus, and CINHAHL via EBSCOhost. 57 studies were included for meta-analysis. Results highlighted significantly higher fat-free mass in senior elite than senior sub-elite or junior elite athletes for all RU and RL forwards. Small and non-significant differences were found in fat mass between rugby union playing standards and age categories. Rugby league senior elite forwards had less fat mass than junior elite forwards. Practitioners should prioritise training and nutritional strategies that maximise fat-free mass development, especially in junior elite cohorts.  相似文献   

The effect of exercise interventions on resting metabolic rate: A systematic review and meta-analysis     

Kristen MacKenzie-Shalders  Jaimon T. Kelly  Daniel So  Vernon G. Coffey  Nuala M. Byrne 《Journal of sports sciences》2020,38(14):1635-1649

ABSTRACT

The systematic review and meta-analysis evaluated the effect of aerobic, resistance and combined exercise on RMR (kCal·day^-1) and performed a methodological assessment of indirect calorimetry protocols within the included studies. Subgroup analyses included energy/diet restriction and body composition changes. Randomized control trials (RCTs), quasi – RCTs and cohort trials featuring a physical activity intervention of any form and duration excluding single exercise bouts were included. Participant exclusions included medical conditions impacting upon RMR, the elderly (≥65 years of age) or pregnant, lactating or post-menopausal women. The review was registered in the International Prospective Register of Systematic Reviews (CRD 42,017,058,503). 1669 articles were identified; 22 were included in the qualitative analysis and 18 were meta-analysed. Exercise interventions (aerobic and resistance exercise combined) did not increase resting metabolic rate (mean difference (MD): 74.6 kCal·day^-1[95% CI: ?13.01, 161.33], P = 0.10). While there was no effect of aerobic exercise on RMR (MD: 81.65 kCal·day^-1[95% CI: ?57.81, 221.10], P = 0.25), resistance exercise increased RMR compared to controls (MD: 96.17 kCal·day^-1[95% CI: 45.17, 147.16], P = 0.0002). This systematic review effectively synthesises the effect of exercise interventions on RMR in comparison to controls; despite heterogenous methodologies and high risk of bias within included studies.  相似文献   

Application of colour metallography in the examination of ancient metals     

David A. Scott 《文物保护研究》2014,59(2):113-122

The use of colour in the metallographic examination of ancient metals is useful both for research and teaching purposes. Application of different optical methods of examination include: polarized light, with or without a first-order red compensator, and differential interference contrast microscopy (DIC). The use of DIC can be combined with the other techniques mentioned in the text for the examination of etched or unetched metal surfaces, which are best observed microscopically using a metallograph. Colour techniques are now used routinely in industrial metallography, and are available for a variety of metals and alloys. Colour tint etching can be used to enhance grain structure or different phases present in the metallic artefact which may not be visible in conventional etched samples, or which lack optical contrast. Many more applications of these techniques in the examination of ancient metals will be published in the literature as they become better known and second-hand equipment with DIC lenses enter the market at a price suitable for conservation laboratories to purchase them.  相似文献   

Mathematica互交功能在物理教学中的应用     

马军 《中国现代教育装备》2011,(21):17-19

数学软件Mathematica是一款功能强大的软件,有着广泛的应用。通过机械波的干涉和光栅衍射的实例,简单介绍了如何利用Mathematica来制作互动应用。以此来加强课堂教学效果,激发学生的兴趣,加深他们的理解。  相似文献   

论我国财政投融资体系的改革和完善     

刘标胜 《江苏经贸职业技术学院学报》2007,(2)

根据新古典经济学及凯恩斯主义的观点和博弈论的分析方法,政府干预经济具有其必要性。在市场经济中,政府干预经济最有效的手段之一就是财政投融资。针对我国财政投融资刚刚起步,在体制、法律和运作方式等方面还存在很多不足的现状,研究借鉴发达国家的财政投融资运作模式,探讨我国财政投融资的发展方向、运作模式及相关法律制度建设,有助于完善我国的财政投融资体系。  相似文献   

石墨炉原子吸收直接法测定海水镍和钒     

黄卓尔  杨秀环  郭越生  张展霞 《中山大学学报论丛》1990,(1)

本文研究了海水基体和共存离子对镍和钒的影响,选用酒石酸、乙酸铵分别作为镍和钒的基体改进剂。未加基体改进剂前,海水镍回收率只有77％,钒的测量精度为11％;加人改进剂后均有改善。采用塞曼效应背景校正技术,热解涂层石墨管,建立了石墨炉原子吸收直接测定海水镍和钒的分析方法。镍和钒的特征质量值(mo)分别为8.4pg和17pg;实际检测限:镍为0.25μgL~(-1)和钒为0.41μgL~(-1)。回收率镍为86～110％,钒为88～106％范围。最大相对标准偏差为谋5.5％,钒4.2％。  相似文献   

我国公共卫生支出的发展效应分析   总被引：2，自引：0，他引：2  

孙菊 《中国软科学》2003,(11):22-26,32

本文认为，公共卫生支出不仅是政府干预卫生服务市场失灵的手段，而且还通过改善人们的健康状况等多种途径作用于经济增长和社会公平。与此同时，加强公共卫生支出还可缓解经济增长过程中收入分配不公平所带来的健康不平等。  相似文献   

双语词汇通达：理论、范式及其研究进展     

王亚鹏  李继利  丁小兵 《宁波大学学报(教育科学版)》2011,33(5):19-24

从双语词汇通达的理论假设、研究范式、实验研究等方面介绍了当前双语词汇通达的研究现状与进展。指出了目前双语词汇通达研究面临的一些问题以及未来的研究方向,认为未来的研究一方面要运用多种研究范式探讨双语词汇通达的机制,另一方面要探讨双语词汇通达的机制是否因为双语类型的不同而不同。  相似文献