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91.
Bone turnover is affected by exercise throughout the lifespan, especially during childhood and adolescence. The objective of this study was to investigate the impact of different sports on total and regional bone mineral density in male Brazilian adolescent athletes. Forty-six adolescents aged 10-18 years participated in the study: 12 swimmers, 10 tennis players, 10 soccer players, and 14 sedentary individuals. The athletes had engaged in physical activities for more than 10 h per week in the previous 6 months. Bone mineral density of the lumbar spine (L1-L4), left proximal femur region, and whole body was evaluated by dual-energy X-ray absorptiometry. Results showed higher mean values in the proximal femur region of tennis and soccer players (1.02 ± 0.18; 0.96 ± 0.16, respectively) than swimmers and controls (0.91 ± 0.14 and 0.87 ± 0.06, respectively) (P < 0.05). In relation to the impact of sporting activities based on bone age determination, we observed significant differences in bone mineral density at all evaluated sites at the end of puberty (16-18 years) compared with 10-12 years, with increases of 78% in the lumbar spine, 47% in the proximal femur, and 38% in the whole body. 相似文献
92.
Seckel María José Vásquez Claudia Samuel Marjorie Breda Adriana 《Education and Information Technologies》2022,27(3):2955-2975
Education and Information Technologies - Computational thinking in the educational environment has awaken a rising interest, having been included as part of the curricula from the very beginnings... 相似文献
93.
José O. Díaz 《The Reference Librarian》2014,55(3):224-233
Changes in information and technology continue to test how librarians interact with and support patrons. Now, engaged librarians have the opportunity to immerse themselves in their user’s workflows and become partners in the research enterprise. Engagement represents a model of librarianship in which librarians are challenged to move from the traditional collection-centered model to an engaged-focused one. It requires new roles and tasks, as well as a deeper understanding of the academic setting. This article discusses working in a large research institution and articulates the engagement model. 相似文献
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95.
体育运动对免疫系统及上呼吸道影响的研究 总被引:2,自引:0,他引:2
曾三明 《武汉体育学院学报》2001,35(2):98-100
激烈运动及较高的心理压力会抑制运动员体内的免疫系统;相反,适度的有氧运动则有提高运动员体内免疫功能的效果。保持适当的运动量,养成良好的卫生习惯,避免接触传染,对运动员的健康维护与体质的增强都将有所裨益。 相似文献
96.
Su San 《中外文化交流(英文版)》2005,(9):20-23
Silk screen printing is an innovative modern art genre highly relying on technologies and media materials. Although it was only introduced into China twenty years ago, it has quickly stood out of the shadow of wood printing and broken through the confines of materials and tools, developing into an independent style integrating modern art and oriental culture. 相似文献
97.
98.
Rupprecht P Golé L Rieu JP Vézy C Ferrigno R Mertani HC Rivière C 《Biomicrofluidics》2012,6(1):14107-1410712
We have developed a method for studying cellular adhesion by using a custom-designed microfluidic device with parallel non-connected tapered channels. The design enables investigation of cellular responses to a large range of shear stress (ratio of 25) with a single input flow-rate. For each shear stress, a large number of cells are analyzed (500–1500 cells), providing statistically relevant data within a single experiment. Besides adhesion strength measurements, the microsystem presented in this paper enables in-depth analysis of cell detachment kinetics by real-time videomicroscopy. It offers the possibility to analyze adhesion-associated processes, such as migration or cell shape change, within the same experiment. To show the versatility of our device, we examined quantitatively cell adhesion by analyzing kinetics, adhesive strength and migration behaviour or cell shape modifications of the unicellular model cell organism Dictyostelium discoideum at 21 °C and of the human breast cancer cell line MDA-MB-231 at 37 °C. For both cell types, we found that the threshold stresses, which are necessary to detach the cells, follow lognormal distributions, and that the detachment process follows first order kinetics. In addition, for particular conditions’ cells are found to exhibit similar adhesion threshold stresses, but very different detachment kinetics, revealing the importance of dynamics analysis to fully describe cell adhesion. With its rapid implementation and potential for parallel sample processing, such microsystem offers a highly controllable platform for exploring cell adhesion characteristics in a large set of environmental conditions and cell types, and could have wide applications across cell biology, tissue engineering, and cell screening. 相似文献
99.
The aim of this paper is to characterize the distribution of number of hits and spent time by web session. It also expects to find if there are significant differences between the length and the duration of a session with regard to the point of access–search engine, link or root. Web usage mining was used to analyse 17,174 web sessions that were identified from the webometrics.info web site. Results show that both distribution of length and duration follow an exponential decay. Significant differences between the different origins of the visits were also found, being the search engines’ users those who spent most time and did more clicks in their sessions. We conclude that a good SEO policy would be justified, because search engines are the principal intermediaries to this web site. 相似文献
100.
Training and psychosocial patterns during the early development of Portuguese national team athletes
This study explored the early development of expert athletes compared to a group of athletes that did not achieve an expert level of performance despite being involved in youth events with their national squads. In particular, the activities, training patterns, and psychosocial influences that characterized their paths in competitive sports were examined. Male and female participants (N?=?42) from different sports were interviewed. Overall, athletes showed several commonalities. However, experts were selected to national squads later and also started thinking about investing in becoming elite athletes later. Non-experts revealed more parental pressure and less individual training with coaches. 相似文献