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91.
The aims of this study were to examine the changes in plasma concentrations of inflammatory cytokines induced by training and competition in professional cyclists. We report the serum concentrations of interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-a), tumour necrosis factor receptors I and II (TNFR-I and -II) in a prospective, randomized, double-blind trial involving the administration of AM3 (Inmunoferon), an oral booster immunomodulator, or placebo to 16 professional cyclists (n = 8 in each group) for 65 consecutive days. Serum was collected just before treatment began (baseline), at the end of pre-competition training, before the mountain stage of the competition (60 days), 4 h after finishing this stage (62 days), and 18 h after the fifth and last day of competition (65 days). To determine the normal levels of cytokines and soluble TNF receptors, individual samples from 14 moderately trained healthy controls were studied. After 60 days of training, the serum concentrations of IL-6 did not differ significantly from those at the beginning of the study for either group of cyclists (placebo and AM3). A significant rise was seen in IL-6 concentrations in both the AM3 and placebo groups at 62 days, 4 h after finishing the mountain stage. The increase was significantly greater in the placebo group than in the AM3 group. At 65 days of treatment, 18 h after the fifth and last day of competition, IL-6 concentrations were similar to those recorded at the end of the training, but were significantly higher in the placebo group than in the AM3 group. At the end of training, serum TNFR-I concentrations in both groups of cyclists were significantly lower than at baseline. The concentrations of serum TNFR-I and -II both 4 h after finishing the mountain stage and 18 h after the fifth and last day of competition were significantly higher than those recorded after training in both groups. Professional cycling competition is associated with increases in serum IL-6 and TNFR-I and -II concentrations. Inmunoferon treatment reduced significantly the concentrations of IL-6 but not those of TNFR-I and -II. 相似文献
92.
The development of peak performances is a main research focus in sports science. It is unclear how many former top junior athletes achieve success in the elite class later. The aim of the present study was to examine the careers of athletes who participated in major junior or adult/elite cycling events using prospective and retrospective analysis of competition results. The official results of major junior (age < or = 18 years) and elite (age > 18 years) cycling races from 1980 to 2004 were analysed. Age-related aspects, career lengths, and success were compared between riders who presented results in both junior and elite races (JUNIOR ELITE) and riders who had no junior race results (ELITE ONLY). Altogether, 27,454 results of 8004 athletes from 108 countries were collected. We found that 29.4% of the elite athletes had participated in junior World Championships, and that 34% of the participants in junior World Championships later participated in major elite competitions. JUNIOR ELITE athletes are significantly more successful in several cycling disciplines and have their first and last elite result at a younger age than ELITE ONLY athletes. No difference was found in career lengths. The data presented here emphasize the importance of long-term training programmes in the development of peak performance in cycling. 相似文献
93.
The aim of this study was to examine the relationship between indicators of risk of disordered eating, body image and varied menstrual cycle lengths. Altogether, 151 female athletes were invited from 16 sports and 70 female non-athletic controls were recruited from a university lecture class. The participants completed several surveys, including demographics, menstrual cycle history, physical activity, Eating Disorder Inventory (EDI) and the Three Factor Eating Questionnaire (TFEQ). Selected EDI subscales were summed to reflect eating disorder risk and body image. Menstrual cyclicity was based on self-reported cycle length for the last 6 months (normal cycles = 26-32 days, irregular cycles < or =26 or >32 days). Athletes overall had more irregular cycles (29.1%) than the non-athletes (15.7%) (P < 0.05). There were significant differences in scores for eating disorder risk, body dissatisfaction, drive for thinness, cognitive restraint (TFEQ) and disinhibition (TFEQ), only when athletes were divided based on menstrual cyclicity (i.e. irregularly cycling athletes had higher scores than athletes with normal menstrual cycle lengths). No differences in these scores were found between non-athletes with normal or irregular menstrual cycle lengths. In conclusion, irregularly short or long menstrual cycle length is associated with subtle indications of higher risk of disordered eating in female athletes. 相似文献
94.
教师与学生关系的性质对学生自觉性和自尊心的形成有极重要的意义.教育工作的实际经验指出,假定教师能对个别学生表扬他的任何积极方面,那末,学生就能开始注意并培养自已的这些优点. 在很多情况中,学生对自己力量没有自信心的原因,就是在教师方面对他们的能力估计不足。这个事实指出了教师与学生建立的关系上所产生的感化作用是多麽巨大,它不仅能够破坏个别学生,而且还能破坏全级学生对自己力量的信任.女教师纳·克,为了对自己的工作做得不好作辩护,经常向学生们说,他们没有能力,总是不肯好好学习等话。结果,学生们本来能够学习得很好的,丧失了自信心,这样,他们就学习得更坏,成为学校里成绩最坏的一班。这就是说:女教师纳·克只看见了学生的弱点。但是在某一时期内,这个女教师的位置上派来了另一位新教师,她很有经验而且也富有钻研心.最初几天,她注意了学生思想上已有的习惯,和他们一班所以在“学校中最坏”的原因。她就在班上开始培养学生对自己力量的自信心.她从思想上去影响学生,告诉他们,如果能够坚持和系统地工作,便会学习得很好.女教师与学生们的新的关系和正确地组织教学工作,获得了非常良好的成绩.学生们对待自己也不同了,他们信任了自己的力量,对未来的发展前途表现了无限向往.这一班“眼看着”有了转变。过了几个月,学生们自己 相似文献
95.
在教学过程中进行经常而有系统的复习是学生进步条件之一。在语文课中的自然知识也应当进行综合复习的。在这种课上,只是复习已教过的最基本的和最重要的材料:明确学生的概念,扩大学生的理解力,补足学生的知能。一至三年级的综合复习课大概每一堂课可以复习一课。进行综合复习课时,必须尽量利用过去所应用过的一切教材(例如:实物教材:“活的和干燥的植物和动物标本”、图片、表格、模型、自然历、地图等等)。 相似文献
96.
一九……年五月十一日二十点十二分莫斯科时间。舱中映射着喷气式发动机和喷出的红色火焰的反照。仅历数分之一秒我们的“ЛК—3”号便稳静地与地球的新卫星——小月球分离开了。小月球是苏维埃人用自己的智慧和双手创造出来的。它是一切星球间航行艇的起点。 相似文献
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我們的地球和其他行星是怎樣形成的呢?人們很久就對這个问题感到興趣了。可是直到最近以前科学還不能给他一個正確的答案。僅僅是許多不同的科學假定。 蘇聯科学界去年宣佈了自己关於行星起源研究工作的總結。這是关於地球和其他行星起源的最正確的新理論,是由奥·尤·施密特院士最先提出來的。假如我們從遙遠的宇宙空间來看我們的地球,就可以看到這样的景像:地球和其他行星繞着太陽,一直向着一定的方向運博。行星的路徑成为圆形而且排列在一個平面内。此外,所有的行星好像陀螺一樣,依着一定的方向旋轉。這正说明了太陽系是一个非常精確的結構,各行星不是单独地而是在同一個時間內一起產生的。到形成行星時,太陽周圍有很多小分子——灰塵在運轉。這些灰麈互相黏在一起同時逐渐地結合成一個大的球體——行星。地球也是這樣產生的。 資本主義国家的科学家說:地球和行星是當着某星球經過太陽时,從太陽拋出的轉動物質形成的。因此,他們認 相似文献