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   2468453篇
  免费   173350篇
  国内免费   4889篇
耳鼻咽喉   33243篇
儿科学   81084篇
妇产科学   67418篇
基础医学   351189篇
口腔科学   71437篇
临床医学   222814篇
内科学   473767篇
皮肤病学   56132篇
神经病学   190722篇
特种医学   93853篇
外国民族医学   437篇
外科学   372462篇
综合类   54555篇
现状与发展   5篇
一般理论   767篇
预防医学   181060篇
眼科学   58998篇
药学   186919篇
  13篇
中国医学   6311篇
肿瘤学   143506篇
  2021年   19169篇
  2019年   19550篇
  2018年   28266篇
  2017年   21661篇
  2016年   24200篇
  2015年   27275篇
  2014年   37633篇
  2013年   54954篇
  2012年   75718篇
  2011年   79741篇
  2010年   47180篇
  2009年   44087篇
  2008年   73445篇
  2007年   78346篇
  2006年   78962篇
  2005年   75258篇
  2004年   72448篇
  2003年   69097篇
  2002年   66454篇
  2001年   128132篇
  2000年   131141篇
  1999年   108772篇
  1998年   28524篇
  1997年   24926篇
  1996年   25013篇
  1995年   23909篇
  1994年   21820篇
  1993年   20386篇
  1992年   82141篇
  1991年   79201篇
  1990年   77000篇
  1989年   73892篇
  1988年   67157篇
  1987年   65427篇
  1986年   61861篇
  1985年   58636篇
  1984年   42940篇
  1983年   36559篇
  1982年   20543篇
  1979年   38250篇
  1978年   26306篇
  1977年   22899篇
  1976年   20764篇
  1975年   22597篇
  1974年   26988篇
  1973年   25995篇
  1972年   24292篇
  1971年   22672篇
  1970年   20959篇
  1969年   19817篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Application of thiamine (1 X 10(-11)-1 X 10(-3) mol/l) on the membrane of cochlear round window increased the amplitude and decreased the latency of the auditory nerve action potential, waves I and II of brainstem auditory-evoked electrical potentials in response to acoustic clicks of different intensity. The mechanism of thiamine action on auditory-evoked electric potentials is discussed.  相似文献   
992.
Two million burns occur annually in the USA, of which 95% aretreated in an out-patient setting. The treatment of burns iscontroversial. There are few data from controlled studies toprovide rational guidelines for the frequency of both dressingchanges and patient visits for the physician. Conclusions concerninginfection drawn from studies on major burns are misleading whenapplied to the management of minor burns. Trauma to regeneratingepithelium caused by frequent dressing change is of relativelyless importance in treating major burns, because the controlof infection is of overriding importance. In the treatment ofminor burns, the traumatic consequences of too frequent changesof dressing may assume greater importance. There is a clearneed to study the variables in the treatment of minor burnsand to generate criteria for their clinical management thatare distinct from those of major burn management. Collaborativestudies of out-patient populations by providers of primary healthcare are suggested as a useful approach to such investigation.The effects of several additional therapies are reviewed, includinginitial cold therapy, debridement of blisters and antibiotics.  相似文献   
993.
994.
995.
We examined several possible causes for the high incidence of poor sensory acuity in the limbs of 176 patients with moderate to severe peripheral vascular insufficiency. We investigated the relationships of diabetes, alcoholism, and smoking, as well as the severity of peripheral vascular disease, to the integrity of basic sensory modalities such as two-point discrimination and perception of light touch. The presence or absence of diabetes exerted the strongest effect on peripheral sensation. In patients who did not have diabetes, sensation in the limbs was most strongly affected by whether the patient was an alcoholic. Smoking did not have a significant effect on limb sensation. Among nondiabetic, nonalcoholic patients, there was a weak residual effect related to the severity of the peripheral vascular insufficiency. Even among these patients, however, systemic factors predominated in determining the loss of sensation. We also examined the extent to which loss of sensation might be related to the development of ulcers. Among patients who were not diabetic, there was a highly significant relationship between loss of sensation and the presence of limb ulceration. Surprisingly, however, there was no discernable relationship between the presence of ulcers in diabetic patients and the degree of loss of peripheral sensation. This result suggests that a large percentage of ulcers seen in diabetic patients are not of neurogenic origin.  相似文献   
996.
Work therapy and return to work   总被引:2,自引:0,他引:2  
In summary, data were selected for 1 year on patients treated in the Work Tolerance Program at the Hand Rehabilitation Center in Philadelphia. The type of information obtained has been used to obtain a profile of the patient population in the Work Tolerance Program. Statistical analysis was used, not only to formulate patient demographics, but also to evaluate the length of treatment of patients in the Work Tolerance Program. This period averaged 6 weeks. The statistical analysis also revealed there was significant interaction between the type of injury and the patient's diagnosis, and the rate of return to work. The patients with injuries to bone and nerve required longer periods of treatment until they returned to work than did patients with injuries to soft tissue or combination injuries. Our statistical analysis revealed that in 1982, 75 per cent of the patients in the Work Tolerance Program returned to work to regular or modified jobs. The length of time from injury to return to work was 63 per cent longer for patients with Workers' Compensation coverage than for patients with private insurance coverage. Because the statistical analysis that 60 per cent of the patients treated in the Work Tolerance Program were Workers' Compensation insured, and 80 per cent of the patients treated in the Work Tolerance Program were secondarily referred, it should be recognized that all patients with severe hand injuries would benefit from an immediate referral to a Hand Rehabilitation Center of excellence to facilitate their therapeutic management and expedite their recovery from time of injury to return to work. This study was restricted to the analysis of length of treatment and rate of return to work. Future studies should study the effect of early referral and the application of specific treatments.  相似文献   
997.
Supplementation of the diet of adult male rats with 4,000 ppm zinc as ZnSO4 for 30 to 32 days increased the zinc content in the testis and sperm by 25 and 18 per cent respectively, but did not change the same in accessory reproductive tissues, e.g. epididymis, seminal vesicle and prostate. The incidence of conception from mating between normal females and zinc fed males was lower as compared to mating between normal females and control males. This observation indicated reduced fertility of the males resulting from additional zinc ingestion. Motility of the sperm collected from the epididymis (tail) of the zinc treated rats was found to be inhibited. It has been suggested that excess zinc in the sperm was responsible for their poor motility and hence a reduced fertilising capacity.  相似文献   
998.
999.
Others have reported that spinal cord transection non-uniformly affects the activities of the cardiac, renal and splenic nerves. We were unable to confirm this finding while recording the wide band (1-1000 Hz) discharges of these sympathetic nerves in baroreceptor-denervated, chloralose-anesthetized cats. Most of the power in nerve discharges was below 6 Hz. There was high coherence between the low frequency discharges of different nerves, and power below 15 Hz was essentially eliminated by spinal transection. Evidence is presented that the disparities between this and past studies are, in part, due to the use of a 30-Hz high-pass filter in the earlier studies.  相似文献   
1000.
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