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   22228篇
  免费   1776篇
  国内免费   39篇
耳鼻咽喉   228篇
儿科学   625篇
妇产科学   528篇
基础医学   2922篇
口腔科学   534篇
临床医学   2462篇
内科学   3996篇
皮肤病学   365篇
神经病学   2051篇
特种医学   803篇
外科学   3578篇
综合类   396篇
一般理论   29篇
预防医学   2061篇
眼科学   459篇
药学   1801篇
  3篇
中国医学   13篇
肿瘤学   1189篇
  2022年   156篇
  2021年   375篇
  2020年   243篇
  2019年   369篇
  2018年   408篇
  2017年   294篇
  2016年   356篇
  2015年   412篇
  2014年   577篇
  2013年   841篇
  2012年   1294篇
  2011年   1355篇
  2010年   741篇
  2009年   656篇
  2008年   1137篇
  2007年   1200篇
  2006年   1180篇
  2005年   1073篇
  2004年   1025篇
  2003年   982篇
  2002年   852篇
  2001年   521篇
  2000年   554篇
  1999年   468篇
  1998年   270篇
  1997年   180篇
  1996年   203篇
  1995年   174篇
  1994年   147篇
  1993年   161篇
  1992年   415篇
  1991年   366篇
  1990年   381篇
  1989年   344篇
  1988年   347篇
  1987年   327篇
  1986年   307篇
  1985年   335篇
  1984年   267篇
  1983年   222篇
  1982年   157篇
  1981年   135篇
  1980年   125篇
  1979年   237篇
  1978年   176篇
  1977年   125篇
  1976年   117篇
  1974年   121篇
  1973年   128篇
  1970年   115篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
A methaemoglobin former, 4-aminopropiophenone (p-aminopropiophenone, PAPP), which is active only after metabolic activation in vivo, exhibits a sex difference in male Beagle dogs and bitches. Bitches produced more methaemoglobin for a given dose of PAPP than male dogs. The probable reason for this difference was a lower rate of N-hydroxylation in male dogs.  相似文献   
42.
Four women presented with symptomatic hypercalcaemia and raised concentrations of serum parathyroid hormone (PTH). In each case, serum calcium returned spontaneously to normal. In two patients serum PTH also fell to the normal range and biochemical relapse has not occurred despite prolonged follow-up. In the others, serum PTH remained elevated and subsequent symptomatic hypercalcaemia necessitated parathyroidectomy. In the first two cases, autoparathyroidectomy is the most likely explanation; the initial fall in serum calcium in the other two patients is unexplained. Large fluctuations in serum calcium may occur in some patients with hyperparathyroidism and prolonged and careful observation is required when this occurs.  相似文献   
43.
Walking after stroke. Measurement and recovery over the first 3 months   总被引:4,自引:0,他引:4  
Sixty surviving patients had their walking ability and speed assessed regularly over the first 3 months after an acute stroke. Sixty-four matched controls were studied to allow categorisation of speed as 'slow' or 'normal'. Fourteen patients never had any significant loss of walking speed; fifteen patients never recovered the ability to walk and one patient remained dependent upon verbal support. Of the 30 showing significant recovery, only 10 regained normal speed, and 8 remained dependent upon a physical aid at 3 months. Plotting individual recovery curves of walking speed over time showed the wide range of change which may be expected. It is argued that timing of gait over 10 metres is a valid reliable measure that is currently underused.  相似文献   
44.
Traditionally, neuropsychological deficits due to Sickle Cell Disease (SCD) have been understudied in adults. We have begun to suspect, however, that symptomatic and asymptomatic Cerebrovascular Events (CVE) may account for an alarming number of deficits in this population. In the current brief review, we critically evaluated the pediatric and adult literatures on the neurocognitive effects of SCD. We highlighted the studies that have been published on this topic and posit that early detection of CVE via neurocognitive testing, neuropsychiatric evaluations, and neuroimaging may significantly reduce adult cognitive and functional morbidities.  相似文献   
45.
Background The aim of the present study was to identify factors associated with the level of psychological distress reported by family carers of children with intellectual disability living in a large urban conurbation. Method Information was collected by postal questionnaire (or interview for family carers who did not have English as their first language) from the family carers of 408 children with intellectual disability (31% of all children within the area administratively identified as having an intellectual disability). Results Results indicated that 47% of primary carers scored above the threshold for psychological distress on the GHQ and that scoring above the threshold was strongly related to the emotional and behavioural needs of the index child and South‐Asian ethnicity and moderately associated with the severity of the child's delay in communication. Conclusions The rates of psychological distress (47% overall, 70% among South‐Asian carers) were markedly higher than that found in previous studies of carers supporting a child with intellectual disabilities. It is suggested that these elevated rates of psychological distress may be mediated by socio‐economic deprivation.  相似文献   
46.
The existence of a novel cubic liquid crystalline phase is described within the pseudo-ternary system comprising lauric acid, monolaurin, and simulated endogenous intestinal fluid (SEIF). This phase behaviour has been characterized using cross-polarizing light microscopy (CPLM), and the structure of the cubic phase identified by small angle X-ray scattering (SAXS). The presence of the cubic phase was found to be temperature sensitive within the 20-37 degrees C range making it putative material for in situ gelation purposes. The cubic phase was shown to have a high capacity to solubilise a model poorly water-soluble drug, cinnarizine, and initial in vitro release data highlight the potential of this phase to provide sustained release. Absorption of cinnarizine from the cubic phase was studied in an unconscious rat model via duodenal administration and blood sampling via the carotid artery. The rate of absorption was significantly reduced when compared to a simple suspension formulation, a likely combination of retarded erosion of the cubic phase together with hindered drug release from the cubic matrix. The results of this study suggest that this cubic phase may potentially be of benefit in the delivery of poorly water-soluble compounds due to its high loading capacity and potential for sustained release. The ability to manipulate this system using temperature may warrant further interest in delivery applications via other routes of administration.  相似文献   
47.
Pudendal nerve palsy is a reported complication of hip arthroscopy. We report a technique using a deflated taped beanbag rather than a perineal post. The patient is placed in the supine or lateral position on a fracture table. The beanbag is contoured around the patient’s flank and thorax. The distal aspect of the beanbag is placed no further than the iliac crest, and care is taken to avoid compression of the posterior aspect of the axillary region or the posterior humerus. The molded beanbag is deflated, a blanket is positioned over the abdomen and lower thorax, and with the use of 3-in-wide cloth tape, the patient and beanbag are secured to the operative table circumferentially. The superior margin of the deflated beanbag remains firm, preventing compression of the thorax and avoiding compromised ventilation. The arm on the operative side is placed across the chest and secured to avoid obstruction of the operative field. This patient positioning provides sufficient stability for adequate traction and good visualization while minimizing the risk of a pudendal nerve palsy.  相似文献   
48.
49.
Chorioretinal neovascular membranes are a recognised but rare cause of late visual loss in eyes suffering contusional injuries. A series of eight cases is presented all with indirect choroidal ruptures involving the perifoveal region. Two main patterns of 'at risk' rupture were noted: a temporally situated rupture passing almost directly through the fovea, and a rupture which curves inferior or superior to the optic disc stopping just short of the fovea. In six of eight cases there was only a partial thickness rupture of the choroid. These neovascular membranes may present at any time after the original injury, either early (within six months of the injury), which could be related to persistence of the normal reparative neovascular response, or late (at least one year after the injury), which are more likely to have resulted from a secondary breakdown of the outer blood-retina barrier.  相似文献   
50.
A case of benign symmetrical lipomatosis (Madelung-Launois-Bensaude syndrome) is described. The characteristic clinical features and the association with chronic alcoholism are reported.  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