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   2428987篇
  免费   198290篇
  国内免费   4445篇
耳鼻咽喉   35145篇
儿科学   74306篇
妇产科学   64035篇
基础医学   340993篇
口腔科学   68762篇
临床医学   221006篇
内科学   479258篇
皮肤病学   48853篇
神经病学   206074篇
特种医学   97713篇
外国民族医学   891篇
外科学   369371篇
综合类   56885篇
现状与发展   1篇
一般理论   1040篇
预防医学   195421篇
眼科学   56579篇
药学   181035篇
  4篇
中国医学   4469篇
肿瘤学   129881篇
  2018年   25546篇
  2017年   19762篇
  2016年   21637篇
  2015年   24436篇
  2014年   35287篇
  2013年   53416篇
  2012年   72421篇
  2011年   76085篇
  2010年   44630篇
  2009年   42766篇
  2008年   72109篇
  2007年   76625篇
  2006年   77440篇
  2005年   75460篇
  2004年   72541篇
  2003年   70012篇
  2002年   68996篇
  2001年   112872篇
  2000年   116863篇
  1999年   98799篇
  1998年   28401篇
  1997年   26017篇
  1996年   25894篇
  1995年   25000篇
  1994年   23528篇
  1993年   21880篇
  1992年   79661篇
  1991年   76666篇
  1990年   73795篇
  1989年   71037篇
  1988年   66040篇
  1987年   64990篇
  1986年   61537篇
  1985年   58676篇
  1984年   44545篇
  1983年   37928篇
  1982年   23309篇
  1981年   20713篇
  1980年   19415篇
  1979年   41471篇
  1978年   29212篇
  1977年   24558篇
  1976年   22993篇
  1975年   24140篇
  1974年   29776篇
  1973年   28186篇
  1972年   26341篇
  1971年   24241篇
  1970年   22824篇
  1969年   21154篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Factitious illness in children is a phenomenon that results in adverse consequences for the child. Munchausen by proxy is a factitious disorder, first described by Meadow (1977), in which a parent induces or creates the appearance of illness in the child. This article highlights the importance of social work skills in the identification and management of this syndrome, and proposes a format for decision making at various points in the process.  相似文献   
992.
J Schara 《Der Anaesthesist》1986,35(7):395-396
  相似文献   
993.
The morphology of neurons is an important factor for the identification and the study of the changes that occur in the nervous system during development or as a result of disease or an experimental treatment. A number of methods to describe the topological aspects of neuronal morphology is discussed. Furthermore it is illustrated how different groups of neurons can be compared. Although both topological and metrical aspects are considered in the comparative sections emphasis is put on counting instead of measuring. Our intention is to present quick and easy methods that are applicable to camera lucida drawings.  相似文献   
994.
Hirschsprung's disease in young adults   总被引:3,自引:0,他引:3  
Hirschsprung's disease is rarely seen in the young adult, and presents unique problems in management because of the massive dilatation and hypertrophy that occur proximal to the aganglionic rectum or the rectosigmoid colon. The diagnosis, which may be suspected by barium enema, is confirmed by suction or full-thickness biopsy of the rectum that may be complemented by anal manometry. Based on our experience with eight patients, a two-stage surgical reconstruction is recommended, with a preliminary sigmoid colostomy through the normally innervated colon and an associated defunctionalized stoma constituting the initial operation. The distal colonic stoma permits cleansing of the caudal colon while the normally innervated proximal colon reverts to near normal caliber, usually within 2 to 6 months. This approach is in accord with the recommendation of Fairgrieve. Reconstruction using a Duhamel or Soave procedure has given good results. The Duhamel procedure seems preferable when a considerable discrepancy remains between the ganglionic and aganglionic segments of rectum.  相似文献   
995.
996.
Arthroscopy in the treatment of young patients with anterior knee pain   总被引:1,自引:0,他引:1  
Arthroscopy plays an important role in diagnosis in the management of anterior knee pain and may be used for treating the underlying pathology.  相似文献   
997.
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   
998.
Leuko-araiosis.   总被引:1,自引:0,他引:1  
Leuko-araiosis is an unspecific radiologic sign, seen with CT scan or with MRI. It can be found as well in normal elderly persons as in pathological conditions. For the sake of clarity, CT scan and MRI images have to be distinguished. CT leuko-araiosis is linked with vascular risk factors and with age. The situation is more complex for MRI leuko-araiosis (likely on account of the higher sensitivity of MRI). Some images (caps and rims), frequently seen in normal, even young, individuals, are more frequent in aging. On the contrary, abnormal images at a distance from the ventricle are more difficult to interpret. Some of them are due to pathological well defined conditions (small infarcts, Binswanger's disease, cysts, plaques). Others may be secondary to remote pathologies (such as infarcts). Others are due to little specific conditions, such as perivascular dilatations ('état criblé' due to brain vasogenic edema, or to brain atrophy whatever its cause, and more frequently seen in the elderly). Other changes, such as incomplete infarction or myelin pallor with gliosis, have been described. At last, in some cases, no clearcut pathological lesion could be found. Leuko-araiosis may be present in primary degenerative dementia of the Alzheimer type, but it is neither necessary nor sufficient to establish the diagnosis of Alzheimer's disease, and it does not seem more frequent than in elderly controls. The mechanism of leuko-araiosis in Alzheimer's disease is likely multifactorial (for example, cerebral atrophy, amyloid angiopathy, associated hypertensive arteriolosclerosis could be involved). The relationship between leuko-araiosis, myelin pallor and white matter atrophy is poorly understood, and remains to be studied.  相似文献   
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.
Obsessive-compulsive disorder is increasingly recognized in patients of different age groups. Serotonergic agents, such as clomipramine, have been recently found to be useful in the management of this condition. However, unexpected side effects, such as dysphoria, aggressiveness, and paranoid ideation, may occur with therapeutic doses of this compound, as evidenced in the cases of two male adolescents presented here. Possible pathogenetic factors, involving serotonin and serotonin-receptor abnormalities are discussed. Management of these side effects is based on adequate dose reduction and monitorization.  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