组织工程技术在牙槽骨修复中的应用

牙槽骨缺损在临床上较为常见,利用骨组织工程修复牙槽骨缺损成为当今研究热点。本文就骨组织工程中的种子细胞、支架材料、生物活性物质等关键要素的进展以及骨组织工程在修复牙槽骨中的应用研究近况、成瘤性和未来发展趋势等进行综述。     

基于Kinect的虚拟放风筝系统设计

为了在虚拟环境中实现风筝放飞效果,采用Kinect作为输入设备,利用体感设备的骨骼跟踪技术,定义手臂上举、振臂和双手交叉模拟放风筝的常用姿势,设计了虚拟放风筝系统,让用户通过手臂动作在虚拟环境中放飞风筝。在WPF平台上实现风筝场景设计和风筝运动时的动画设计。通过单元测试和集成测试,表明系统使用骨骼数据跟踪技术结合用户自定义手势,操作合理,WPF动画实现场景及风筝运动突破了传统动画限制,用户能在虚拟场景中体验到放风筝的乐趣。     

释"辅车相依"之"辅车"

对"辅车相依"中"辅车"的解释,历来存在分歧.概言之,无非是"车之一物与车"和"面颊与牙床骨"的不同.这两种解释都可说明"辅车相依"的比喻义,但到底哪种说解更正确,更符合历史原义?"辅车相依"中"辅车"的意思到底是什么?通过对现存典籍及以前研究的考察,我们认为"辅"就是大车载物时两旁的挡板,"车"就是古代用来运物的大车.     

甲骨文核心词"人"的语义场初探

甲骨文中与“人”有关的词构成了一个语义场,文中对这些词进行了分析讨论,得出这个语义场的五个类义场:士卒、臣僚、民众、方族、人牲鬼神,其下位词即所分析的词。甲骨文核心词“人”的外延应该是奴隶、战俘、自由劳动者、臣僚、平民及周边少数民族。上位词“人”在甲骨文里面可能是“民”。     

低等真骨鱼类肌间小骨研究现状

鱼类肌间小骨指位于肌节之间的硬骨小刺,由肌隔结缔组织骨化而成。在总结国内外有关肌间小骨研究成果的基础上,从肌间小骨数目、形态和发生等方面对低等真骨鱼类肌间小骨的研究做了综述和展望,以期为今后肌间小骨的分子机制研究提供一些参考。     

Substitution of sedentary time with light physical activity is related to increased bone density in U.S. women over 50 years old. An iso-temporal substitution analysis based on the National health and Nutrition Examination Survey

Abstract

U.S. women are ageing. This is causing rises in osteoporosis prevalence and risk of fracture with related increases in health care costs. Replacing sedentary time with light physical activity may represent a cost effective public health solution to osteoporosis in elderly women. The National Health and Nutrition Examination Survey conducted over the period 2003–2006 provided cross-sectional data on bone mineral density and objectively assessed physical activity among 1,052 women aged 50–85 years old. Substitution analysis was applied to estimate increased bone mineral density and reduced osteoporosis for those women replacing 30?min of sedentary time with an equivalent amount of light physical activity. Substitution of 30?min of sedentary time with an equal amount of light physical activity was associated with increased bone mineral density of about 3?mg/cm2 and a 12% reduced risk of osteoporosis in the spine. When considering overweight women and women over 65 years of age, this association was reinforced and it extended to the pelvis, legs and trunk, resulting in a consistent bone mineral density increase of about 3–6?mg/cm2. The substitution of 30?min of sedentary time with an equal amount of light physical activity appears a possible primary prevention method to reduce osteoporosis and related increases in risk of fracture, mortality, and health care costs in women over 50 years old.     

优秀高山滑雪运动员体质、身体形态学及跟骨超声骨量的研究

在运动训练中,优秀高山滑雪运动员保持较好的体质、身体形态学、跟骨超声骨量对提高高山滑雪项目运动员的运动成绩是非常有好处的。采用文献资料法、测试法、数理统计法对优秀高山滑雪运动员体质、身体形态学与跟骨超声骨量现状进行研究,为其科学运动训练提供借鉴。结果显示：高山滑雪运动员体重、身体质量指数、体脂率、瘦体重显著低于对照组,身高与对照组差异不显著;高山滑雪女子运动员体脂率显著低于对照组,瘦体重显著高于对照组,其他各项指标与对照组差异不显著;运动员体质方面男子高山滑雪运动员握力体重指数显著低于体育大学生,其他各项指标显著高于对照组,女子高山滑雪运动员体质各项指数显著高于对照组;高山滑雪运动员跟骨超声骨量参数均显著高于对照组。     

Effects of physical activities that induce moderate external loading on bone metabolism in male athletes

Sports characterized by little or moderate weight bearing or impact have a low osteogenic effect. However, the action of such sports on bone turnover remains unclear. The objective of this study was to determine the effect on bone remodelling of physical activities that induce moderate external loading on the skeleton. Thirty-eight male athletes aged 18–39 years (cyclists, n?=?11; swimmers, n?=?13; triathletes, n?=?14) and 10 age-matched sedentary controls aged 22–35 years participated in the study. The study combined measurement of bone mineral density by dual-energy X-ray absorptiometry and bone turnover assessment from specific biochemical markers: serum bone-specific alkaline phosphatase, osteocalcin, urinary type I collagen C-telopeptide and calcium. Compared with the controls and swimmers, adjusted bone mineral density was higher (P?<?0.05) in triathletes at the total proximal femur and lower limbs. No differences in bone mineral density were found between cyclists, swimmers and controls. Compared with controls, osteocalcin was higher (P?<?0.05) in triathletes and swimmers and urinary type I collagen C-telopeptide was higher in swimmers only. Serum bone-specific alkaline phosphatase was lower (P?<?0.05) in cyclists than in all other groups. In conclusion, an osteogenic effect was found only in triathletes, mainly at bone sites under high mechanical stress. Bone turnover differed in athletes compared with controls, suggesting that bone turnover may be sport-practice dependent. Despite some encouraging observations, it was not possible to show that changes in the bone remodelling process were sport-discipline dependent.     

Enhancing Motor Learning Through Dyad Practice

Abstract

It has been shown that practice in dyads, as compared to individual practice, can enhance motor learning and increase the efficiency of practice (as two participants can be trained at the same time; Shea, Wulf, &; Whitacre, 1999). The dyad practice protocol used by Shea et al. included both observation and dialogue between partners. Thus, it was not clear whether the learning benefits of dyad practice were due to observation, dialogue, or both. The present study examined the individual and interactive effects of observation and dialogue. The task used was speed cup stacking. Participants practiced under one of four conditions: observation/dialogue, observation/no dialogue, no observation/dialogue, and no observation/no dialogue. The two conditions that included observational practice were more effective (i.e., produced faster movement times) than the two conditions without it, both during practice and on a retention test performed under individual performance conditions. This suggests that the learning advantages of dyad practice are primarily due to the opportunity to observe another learner.     

不同强度跑台运动对老龄雌性大鼠骨量及骨代谢的影响

目的:探讨不同负荷跑台运动对老龄雌性大鼠骨量及骨代谢相关指标的影响.方法:将40只12月龄雌性大鼠随机分为四组:对照组、低强度组、中强度组、高强度组每周6次共训练10周,观察不同强度运动对老龄雌性大鼠全身骨密度,股骨中点皮质骨密度、血清碱性磷酸酶(AKP)骨钙素(BGP)水平的影响.结果:低、中强度运动可使老龄雌性大鼠骨密度增加;三组均可使血清碱性磷酸酶(AKP)、血清骨钙素(BGP)水平升高.结论:低、中强度的跑台运动是一种适合于老年女性的健身方式,可以减缓伴随增龄而发生的骨量丢失,起到预防老年性骨质疏松的作用.