首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1242篇
  免费   4篇
  国内免费   1篇
化学工业   4篇
金属工艺   1篇
机械仪表   5篇
建筑科学   1篇
能源动力   2篇
一般工业技术   1篇
冶金工业   1230篇
自动化技术   3篇
  2019年   1篇
  2018年   2篇
  2017年   1篇
  2015年   2篇
  2013年   2篇
  2011年   1篇
  2008年   1篇
  2006年   2篇
  2004年   1篇
  2003年   2篇
  2000年   1篇
  1999年   42篇
  1998年   401篇
  1997年   201篇
  1996年   145篇
  1995年   80篇
  1994年   53篇
  1993年   77篇
  1992年   4篇
  1991年   17篇
  1990年   18篇
  1989年   12篇
  1988年   24篇
  1987年   15篇
  1986年   13篇
  1985年   8篇
  1983年   2篇
  1982年   6篇
  1981年   10篇
  1980年   12篇
  1979年   1篇
  1978年   6篇
  1977年   23篇
  1976年   59篇
  1975年   2篇
排序方式: 共有1247条查询结果,搜索用时 15 毫秒
31.
In the treatment of diabetes, the importance of kinesitherapy increases steadily. In fact, a prospective study (1996) which was done on 897 Finnish middle-aged males over a period of 4 years, showed that the risk of diabetes can be reduced to 50% by moderate physical exercise of 40 minutes per week compared with less active persons of the same age. The amount of kinesitherapeutic measures depends on the physiological resilience of the diabetes patient and on the extent of existing diabetes-induced lesions. An endurance kinesitherapy activates the carbohydrate metabolism and affects the glucosensitive receptors situated in peripheral and central organs. A muscle activity of ten minutes can already multiply by fifteen the increase of glucose absorption from the blood. Another positive result by physical effort is to be seen in the preventine and therapeutic effect of an increased insuline action. The individually adapted kinesitherapeutic endurance stimulation should last from five to ten minutes each day and reach at least 50% of maximum capacity but not more than 70%. This maximum capacity can among other things be gauged from the heart rate as well as from the breathing rate.  相似文献   
32.
Unlike chlamydial lipopolysaccharide, which is released from the developing inclusion to the surface of infected genital epithelial cells, both Chlamydia trachomatis heat shock protein (hsp) 60 and 70 antigens remained confined within the inclusion during the course of the chlamydial developmental cycle. Exposure of the infected cells to penicillin to induce a persistent infection or to a lipophilic microbicide did not potentiate secretion or exocytosis of the chlamydial hsp.  相似文献   
33.
A regression model for the analysis of survival data adjusting for concomitant information is developed. The model presented can lead to the log linear exponential model (Glasser [1967]) and the life table regression model of Cox [1972]. In addition, the model described can be used to analyze data from the commonly employed actuarial life table. A discussion of the special case where one is comparing two survival curves is presented. The methods developed are illustrated using data from a clinical trial investigating treatments for lung cancer.  相似文献   
34.
35.
OBJECTIVE: To examine the temporal integration of vascular endothelial growth factor (VEGF), which has been shown to be present in wound fluid, with the putatively related processes of wound fluid oxygen content, wound angiogenesis, and granulation tissue formation. SUMMARY BACKGROUND DATA: During cutaneous wound repair, new tissue formation starts with reepithelialization and is followed by granulation tissue formation, including neutrophil and macrophage accumulation, fibroblast ingrowth, matrix deposition, and angiogenesis. Because angiogenesis and increased vascular permeability are characteristic features of wound healing, VEGF may play an important role in tissue repair. METHODS: A ventral hernia, surgically created in the abdominal wall of female swine, was repaired using silicone sheeting and skin closure. Over time, a fluid-filled wound compartment formed, bounded by subcutaneous tissue and omentum. Ultrasonography was performed serially to examine the anatomy and dimensions of the subcutaneous tissue and wound compartment. Serial wound fluid samples, obtained by percutaneous aspiration, were analyzed for PO2, PCO2, pH, and growth factor concentrations. RESULTS: Three independent assays demonstrate that VEGF protein is present at substantially elevated levels in a wound fluid associated with the formation of abdominal granulation tissue. However, the wound fluid is not hypoxic at any time. Serial sampling reveals that transforming growth factor beta-1 protein appears in the wound fluid before VEGF. CONCLUSIONS: The results suggest that VEGF is a prominent regulator of wound angiogenesis and vessel permeability. A factor other than hypoxia, perhaps the earlier appearance of another growth factor, transforming growth factor beta-1, may positively regulate VEGF appearance in the wound fluid.  相似文献   
36.
37.
This study established the emergence of stable individual differences in neurobehavioral functioning prior to birth and examined their relation to subsequent infant temperament. Fetal heart rate and movement were recorded longitudinally for 31 fetuses at 6 gestational ages beginning at 20 weeks' gestation. Maternally reported temperament data were collected at 3 and 6 months. Moderate stability in all measures except reactivity was apparent at some time before birth. By 36 weeks, fetal neurobehavior accounted for between 22% and 60% of the variance in prediction of temperament scores. In general, more active fetuses were more difficult, unpredictable, unadaptable, and active infants. Higher fetal heart rate was associated with lower emotional tone, activity level, and predictability. We conclude that features of fetal neurobehavior provide the basis for individual differences in reactivity and regulation in infancy.  相似文献   
38.
39.
40.
Computerizing an organization's policies and guidelines is difficult but rewarding. The assessment, planning, implementation, and evaluation of converting all paper policies and procedures into a computerized system are outlined, with particular focus on organizing guidelines according to the Joint Commission on Accreditation of Healthcare Organization's (JCAHO) functional standards.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号