集训对舞龙队女大学生血常规及内皮祖细胞的影响     

孔明涯  任路遥 《体育科技文献通报》2020,(4):156-158

目的:分析舞龙运动对女大学生血常规及内皮祖细胞含量的影响。方法:选取2017级舞龙队女大学生10人为训练组,2017级普通女大学生10人作为对照组。舞龙队女大学生备战比赛进行连续4周,每周3次,每次90min的赛前集训,普通女大学生除日常活动外,没有额外进行任何其他运动队的集训。集训结束后,在受试者都处于空腹状态下对两组受试者进行静脉采血并进行血常规、早期内皮祖细胞和晚期内皮祖细胞的检测。所得数据进行统计学分析。结果:参加舞龙集训的女大学生的血常规指标与普通女大学生的血常规指标无显著差异,早期EPCs和晚期EPCs无显著性差异,但在数值上显示出不同的趋势。结论:参加舞龙集训的女大学生身体处于健康状态。参加舞龙集训有可能增强运动员血管的自我修复能力。  相似文献   

Acute cardiovascular responses to interval exercise: A systematic review and meta-analysis     

Kym Joanne Price  Brett Ashley Gordon  Stephen Richard Bird  Amanda Clare Benson 《Journal of sports sciences》2020,38(9):970-984

ABSTRACT

Interval exercise training is increasingly recommended to improve health and fitness; however, it is not known if cardiovascular risk is different from continuous exercise protocols. This systematic review with meta-analyses assessed the effect of a single bout of interval exercise on cardiovascular responses that indicate risk of cardiac fibrillation and infarction compared to continuous exercise. Electronic databases Medline, CINAHL, Embase, Scopus and Cochrane were searched. Key inclusion criteria were: (1) intervals of the same intensity and duration followed by a recovery period and (2) reporting at least one of blood pressure, heart rate variability, arterial stiffness or function. Cochrane Risk of Bias tool and GRADE approach were used. Meta-analyses found that systolic blood pressure responses to interval exercise did not differ from responses to continuous exercise immediately (MD 8 mmHg [95% CI ?32, 47], p = 0.71) or at 60 min following exercise (MD 0 mmHg [95% CI ?2, 1], p = 0.79). However, reductions in diastolic blood pressure and flow-mediated dilation with interval exercise were observed 10–15 min post-exercise. The available evidence indicates that interval exercise does not convey higher cardiovascular risk than continuous exercise. Further investigation is required to establish the safety of interval exercise for clinical populations.  相似文献   

低负荷加压训练改善自发性高血压大鼠的血压效果及机制研究     

谭朝文  赵彦  俞莹莹  马晓缓  郑玉婵 《体育科学》2020,(3):46-53,63

目的:探究低负荷加压训练对自发性高血压大鼠的降压效果及其作用机制。方法:选取4周龄雄性自发性高血压大鼠,随机分为对照组(高血压安静组)、低负荷训练组、低负荷加压训练组和高负荷训练组。低负荷训练组进行35%~55%1RM递进式低负荷爬梯训练,低负荷加压训练组进行30%~40%血流受限结合35%~55%1RM递进式低负荷爬梯训练,高负荷训练组进行55%~75%1RM递进式高负荷爬梯训练,训练后测定血压、血液中内皮素-1、血管内皮生长因子、一氧化氮合成酶的表达和心肌组织中内皮型一氧化氮合成酶的表达。结果:1)与对照组、高负荷训练组相比,低负荷加压训练组收缩压、舒张压显著下降(P<0.05);与低负荷训练组相比,低负荷加压训练组舒张压显著下降(P<0.05)。2)与对照组相比,低负荷加压训练组血液中内皮素-1表达显著下调(P<0.05),血管内皮生长因子和一氧化氮合成酶表达显著上调(P<0.05);3)与对照组相比,低负荷加压训练组心肌中内皮型一氧化氮合成酶表达显著上调(P<0.05);4)在低负荷加压训练组中,收缩压与内皮素-1呈正相关,相关性分析具有统计学意义(P<0.05);收缩压与一氧化氮合成酶、血管内皮生长因子、内皮型一氧化氮合成酶均呈负相关,相关性分析具有统计学意义(P<0.05)。结论:1)低负荷加压训练降压效果优于高负荷训练;2)低负荷加压训练能够通过下调血液中内皮素-1的表达,上调血液中血管内皮生长因子和一氧化氮合成酶的表达,同时上调心肌中内皮型一氧化氮合成酶表达,改善内皮细胞功能,达到降压的效果。  相似文献   

Combined effects of exposure to hypoxia and cool on walking economy and muscle oxygenation profiles at tibialis anterior     

Masahiro Horiuchi  Yoko Handa-Kirihara  Daijiro Abe  Yoshiyuki Fukuoka 《Journal of sports sciences》2019,37(14):1638-1647

We investigated combined effects of ambient temperature (23°C or 13°C) and fraction of inspired oxygen (21%O₂ or 13%O₂) on energy cost of walking (C_w: J·kg^?1·km^?1) and economical speed (ES). Eighteen healthy young adults (11 males, seven females) walked at seven speeds from 0.67 to 1.67 m s^?1 (four min per stage). Environmental conditions were set; thermoneutral (N: 23°C) with normoxia (N: 21%O₂) = NN; 23°C (N) with hypoxia (H: 13%O₂) = NH; cool (C: 13°C) with 21%O₂ (N) = CN, and 13°C (C) with 13%O₂ (H) = CH. Muscle deoxygenation (HHb) and tissue O₂ saturation (StO₂) were measured at tibialis anterior. We found a significantly slower ES in NH (1.289 ± 0.091 m s^?1) and CH (1.275 ± 0.099 m s^?1) than in NN (1.334 ± 0.112 m s^?1) and CN (1.332 ± 0.104 m s^?1). Changes in HHb and StO₂ were related to the ES. These results suggested that the combined effects (exposure to hypoxia and cool) is nearly equal to exposure to hypoxia and cool individually. Specifically, acute moderate hypoxia slowed the ES by approx. 4%, but acute cool environment did not affect the ES. Further, HHb and StO₂ may partly account for an individual ES.  相似文献   

Effects of periodic carbohydrate ingestion on endurance and cognitive performances during a 40-km cycling time-trial under normobaric hypoxia in well-trained triathletes     

Yi-Hung Liao  Toby Mündel  Yan-Ting Yang  Chen-Chan Wei  Shiow-Chwen Tsai 《Journal of sports sciences》2019,37(16):1805-1815

The purpose of this study was to examine CHO ingestion on a cognitive task using a field-simulated time-trial (TT) under hypoxia in well-trained triathletes. Ten male triathletes (age: 22.1 ± 1.1 years; VO₂max: 59.4 ± 1.4 ml/kg/min) participated in this double-blind/crossover/counter-balanced design study. Participants completed 3 TT trials: 1) normoxic placebo (NPLA; FiO₂ = 20.9%), 2) hypoxic placebo (HPLA; FiO₂ = 16.3%), and 3) hypoxic CHO (HCHO; 6% CHO provided as 2 ml/kg/15 min; FiO₂ = 16.3%). During the TT, physiological responses (SpO₂, HR, RPE, and blood glucose/lactate), cognitive performance, and cerebral haemodynamics were measured. Hypoxia reduced TT performance by ~3.5–4% (p < 0.05), but CHO did not affect TT performance under hypoxia. For the cognitive task, CHO slightly preserved exercise-induced cognitive reaction speed but did not affect response accuracy during hypoxic exercise. However, CHO did not preserve the decreased Hb-Diff (cerebral blood flow, CBF) and increased HHb in the prefrontal lobe (p < 0.05) during hypoxic exercise, and CHO failed to preserve hypoxia-suppressed prefrontal CBF and tissue oxygen saturation. In conclusion, the present study demonstrates that CHO is effective in sustaining reaction speed for a cognitive task but not promoting TT performance during hypoxic exercise, which would be important for strategy-/decision-making when athletes compete at moderate high-altitude.  相似文献   

中外历史比较札记六则     

葛志毅 《大连大学学报》2007,28(5):1-10

在世界历史的发展中,往往会在不同的民族间发生些彼此相近似的社会现象。一方面可能是在相近似的社会历史条件下,人们可能采用相类似的应对方法所致;另一方面则可能是不同民族间在文化上相互借鉴的结果;也有可能是偶然如此,无从考察说明其联系。但世界历史的整体性、相互关联性,从来是无可否认的,更有些同中有异,异中见同的历史现象耐人寻味。通过比较的方法研究这类现象,对人们认识历史应该有所启发。这篇文章以比较的方法,指出领土主权、血缘原则与地缘原则、盟约仪式、采地与永佃权、城邦制度与专制制度、法律传统与专制制度等政治法权概念在中外历史上反映出的不同意义,以及与之相关的中外历史发展中的不同社会文化特征,同时也借以追溯相关制度在中外历史上的各自渊源与差别之所在。  相似文献   

SPOC整合翻转课堂教学模式在输血与输血技术课程中的应用和效果评价     

李宗吉  丁淑琴 《科教导刊》2021,(2):146-147,182

探索解决输血与输血技术课程中知识点复杂、实践性强、教学效果不理想等问题的教学新模式,以期提升学生将医学理论知识和临床技能结合用于分析解决临床实际问题的能力.  相似文献   

元极学与针灸学的内在关联     

牛壮志 《人天科学研究》1997,6(2):20-23

根据元极学理论，结合针灸学原理及其医疗实施加以研讨，可知元极图理论对于认识，掌握，运化人体经络气血的功能富有启示；人天整体观，和率等对于掌握和运用天时，地利、人和和条件进行针灸的医疗实施富有启示。  相似文献   

三碘苯酚乙基纤维素微球的制备     

刘瑞丽  姜庆军  刘士远  李文新 《中国科学院研究生院学报》2005,1(5):575-578

为提高造影剂的颗粒度,减少血池造影剂透过血管壁向组织间质渗出,影响血池造影剂的造影效果,采用液中干燥法( in-liquid drying method)制备了三碘苯酚乙基纤维素微球，研究了三碘苯酚与乙基纤维素的比例对微球成球性，粒径以及载药量的影响，发现两者的比例为1：2时成球性最好，所得微球为规整的球形，微球粒径最小，平均粒径D50为3.68um, 载药量为41.4%。  相似文献   

噪声应激对血压及心率变异性的影响     

胡军祥  杨琼霞  黄佩龙  朱栋奎  姜玉新 《科技通报》2007,23(5):681-683,740

对被试者分别进行80dB和100dB的噪声刺激，并在第1、5、10、15和20d测定被试者的动脉血压和心电图，并分析心率变异性变化。实验结果表明：噪声应激使被试者的收缩压升高，心率加快．但对舒张压影响不明显，心率变异性频谱分析显示，高频成分、低频成分增大，而R-R间期减小，而且100dB的作用比80dB显著。提示噪声应激对人体心血管系统的活动有明显的影响。  相似文献