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81.
Phenylethanoid glycosides are naturally occurring water-soluble compounds with remarkable biological properties that are widely distributed in the plant kingdom. Verbascoside is a phenylethanoid glycoside that was first isolated from mullein but is also found in several other plant species. It has also been produced by in vitro plant culture systems, including genetically transformed roots (so-called ‘hairy roots’). Verbascoside is hydrophilic in nature and possesses pharmacologically beneficial activities for human health, including antioxidant, anti-inflammatory and antineoplastic properties in addition to numerous wound-healing and neuroprotective properties. Recent advances with regard to the distribution, (bio)synthesis and bioproduction of verbascoside are summarised in this review. We also discuss its prominent pharmacological properties and outline future perspectives for its potential application.  相似文献   
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83.
Frank B. Hu 《Aging cell》2014,13(3):391-400
Excess body weight and adiposity cause insulin resistance, inflammation, and numerous other alterations in metabolic and hormonal factors that promote atherosclerosis, tumorigenesis, neurodegeneration, and aging. Studies in both animals and humans have demonstrated a beneficial role of dietary restriction and leanness in promoting health and longevity. Epidemiological studies have found strong direct associations between increasing body mass index (BMI) and risks of developing type 2 diabetes, cardiovascular disease, and several types of cancer, beginning from BMI of 20–21 kg m−2. Although a recent meta-analysis suggests that overweight individuals have significantly lower overall mortality than normal-weight individuals, these data are likely to be an artifact produced by serious methodological problems, especially confounding by smoking, reverse causation due to existing chronic disease, and nonspecific loss of lean mass and function in the frail elderly. From a clinical and public health point of view, maintaining a healthy weight through diet and physical activity should remain the cornerstone in the prevention of chronic diseases and the promotion of healthy aging.  相似文献   
84.
Dynamic gait stability can be quantified by the relationship of the motion state (i.e. the position and velocity) between the body center of mass (COM) and its base of support (BOS). Humans learn how to adaptively control stability by regulating the absolute COM motion state (i.e. its position and velocity) and/or by controlling the BOS (through stepping) in a predictable manner, or by doing both simultaneously following an external perturbation that disrupts their regular relationship. Post repeated-slip perturbation training, for instance, older adults learned to forward shift their COM position while walking with a reduced step length, hence reduced their likelihood of slip-induced falls. How and to what extent each individual joint influences such adaptive alterations is mostly unknown. A three-dimensional individualized human kinematic model was established. Based on the human model, sensitivity analysis was used to systematically quantify the influence of each lower limb joint on the COM position relative to the BOS and the step length during gait. It was found that the leading foot had the greatest effect on regulating the COM position relative to the BOS; and both hips bear the most influence on the step length. These findings could guide cost-effective but efficient fall-reduction training paradigm among older population.  相似文献   
85.
Approximately 320,000 anterior cruciate ligament (ACL) injuries in the United States each year are non-contact injuries, with many occurring during a single-leg jump landing. To reduce ACL injury risk, one option is to improve muscle strength and/or the activation of muscles crossing the knee under elevated external loading. This study?s purpose was to characterize the relative force production of the muscles supporting the knee during the weight-acceptance (WA) phase of single-leg jump landing and investigate the gastrocnemii forces compared to the hamstrings forces. Amateur male Western Australian Rules Football players completed a single-leg jump landing protocol and six participants were randomly chosen for further modeling and simulation. A three-dimensional, 14-segment, 37 degree-of-freedom, 92 muscle-tendon actuated model was created for each participant in OpenSim. Computed muscle control was used to generate 12 muscle-driven simulations, 2 trials per participant, of the WA phase of single-leg jump landing. A one-way ANOVA and Tukey post-hoc analysis showed both the quadriceps and gastrocnemii muscle force estimates were significantly greater than the hamstrings (p<0.001). Elevated gastrocnemii forces corresponded with increased joint compression and lower ACL forces. The elevated quadriceps and gastrocnemii forces during landing may represent a generalized muscle strategy to increase knee joint stiffness, protecting the knee and ACL from external knee loading and injury risk. These results contribute to our understanding of how muscle?s function during single-leg jump landing and should serve as the foundation for novel muscle-targeted training intervention programs aimed to reduce ACL injuries in sport.  相似文献   
86.
布鲁氏菌病(简称布病)是由布鲁氏菌属细菌侵入机体引起的人畜共患传染病.近年来,布病疫情在世界范围内呈反弹趋势,我国尤甚.进入2000年以后,人间布病在我国成为报告发病数上升速度最快的传染病之一,令我国布病防治形势严峻.为了明确我国布病防治工作的现状和需求、最新研究现状和研究动态以及面临的挑战和机遇,深入研讨分析我国布病防治研究中的重大科学和关键技术问题,凝练和提出今后我国布病防治研究发展中亟需关注、解决的重要基础科学问题,在国家自然科学基金委员会资助下,由中国疾病预防控制中心地方病控制中心主办,哈尔滨医科大学、中国疾病预防控制中心传染病预防控制所和内蒙古地方病防治研究中心共同协办,于2013年6月21日召开了由来自全国布病防治与基础研究领域专家共同参加的“布鲁氏菌病防治基础研究发展战略研讨会”.会议在我国布病疫情最重的省份内蒙古自治区呼和浩特市召开,中国疾病预防控制中心传染病预防控制所、军事医学科学院疾病预防控制所、石河子大学、中国兽医药品监察所等19家从事布病防治与基础研究的科研院所、高等院校、疾病防治机构的40余位专家参加了此次会议.现结合文献资料以及本次会议的内容,对国内外布病流行现状、研究进展,以及影响我国布病防治的亟需解决的科学问题和建议作一综述.  相似文献   
87.
70年代以来柑桔灾害性天气综述及防御措施   总被引:1,自引:0,他引:1  
张名福 《生态学杂志》2001,20(4):79-80,F004
20世纪 70年代以来 ,我国柑桔 (Citrsreticulata)生产有了迅速增长 ,但由于全球气候的变化 ,出现不利于柑桔生长的灾害性天气 ,并有愈演愈烈的趋势 ,给柑桔生产带来了极大的影响。弄清灾害性天气的发生及规律 ,并提出其防御措施 ,对于进一步科学指导柑桔生产 ,完善柑桔与生境的理论 ,都有一定的现实意义。1 灾害性天气1.1 周期性大冻害据统计 ,公元 14 5 0 - 1979年的 5 2 9年中共出现了 79个严重冻害年 ,平均 10年中有 1.5次。从顺昌县及福建省的气象资料看出 ,约 9~ 10年有 1次周期性的大冻害 ,并在福建省几个县市均有…  相似文献   
88.
Objective: The goal of this study was to evaluate the effect of a parent‐focused behavioral intervention on parent and child eating changes and on percentage of overweight changes in families that contain at least one obese parent and a non‐obese child. Research Methods and Procedures: Families with obese parents and non‐obese children were randomized to groups in which parents were provided a comprehensive behavioral weight‐control program and were encouraged to increase fruit and vegetable intake or decrease intake of high‐fat/high‐sugar foods. Child materials targeted the same dietary changes as their parents without caloric restriction. Results: Changes over 1 year showed that treatment influenced targeted parent and child fruit and vegetable intake and high‐fat/high‐sugar intake, with the Increase Fruit and Vegetable group also decreasing their consumption of high‐fat/high‐sugar foods. Parents in the increased fruit and vegetable group showed significantly greater decreases in percentage of overweight than parents in the decreased high‐fat/high‐sugar group. Discussion: These results suggest that focusing on increasing intake of healthy foods may be a useful approach for nutritional change in obese parents and their children.  相似文献   
89.
黑土稻田CH4与N2O排放及减排措施研究   总被引:11,自引:0,他引:11  
岳进  梁巍  吴杰  史奕  黄国宏 《应用生态学报》2003,14(11):2015-2018
通过对黑土稻田CH4和N2O排放的观测,发现水稻生长季CH4和N2O排放量低于全国其它地区稻田CH4和N2O排放之间存在互为消长关系(r=-0.513,P<0.05),但在同样施肥水平条件下,间歇灌溉与长期淹灌相比,CH4排放明显减少而N2O略有增加,其相对综合温室效应被大大减少且水稻产量未受影响。为此,间歇灌溉可作为减少稻田温室气体排放的水分管理措施。另外,通过对CH4和N2O排放的相关微生物过程探讨,揭示产甲烷菌数与CH4排放问呈显著性正相关(R2=0.82,P<0.05),硝化菌数和反硝化菌数与N2O排放有重要关系。  相似文献   
90.
Abstract. We investigated germination responses and seed recruitment in the clonal grassland herb Knautia arvensis (Dipsacaceae) throughout its distributional range in Norway. Four predicted relationships between germination responses and field regeneration behaviour were tested using phytotron experiments and experimental and observational field studies. Seedlings appeared in all experimental microsites in the field, corroborating phytotron predictions that gap‐ or depth‐sensing strategies should be absent in the species. Seasonal timing patterns were predicted from a cold stratification response in the phytotron, but these were not supported in the field. The relationship between dormancy, germinability during storage, and seed carry‐over in the field largely conformed to expectations. Seeds from four different geographical regions responded differently to temperature and cold stratification and storage. Dormancy and seed carry‐over was higher in seeds from a coastal population, where winters are relatively mild and the probability of repeated freeze‐thaw events is high, than in populations from mountain and inland areas, where winters are colder. This is discussed against two alternative hypotheses about the relationship between climate and dormancy in seasonal climates.  相似文献   
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