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   28880篇
  免费   2125篇
  国内免费   154篇
耳鼻咽喉   268篇
儿科学   1084篇
妇产科学   836篇
基础医学   4307篇
口腔科学   410篇
临床医学   2986篇
内科学   5791篇
皮肤病学   659篇
神经病学   3061篇
特种医学   664篇
外科学   2865篇
综合类   186篇
一般理论   37篇
预防医学   3285篇
眼科学   456篇
药学   1759篇
  1篇
中国医学   44篇
肿瘤学   2460篇
  2023年   356篇
  2022年   606篇
  2021年   1256篇
  2020年   800篇
  2019年   1058篇
  2018年   1160篇
  2017年   873篇
  2016年   947篇
  2015年   1018篇
  2014年   1304篇
  2013年   1601篇
  2012年   2373篇
  2011年   2374篇
  2010年   1255篇
  2009年   1080篇
  2008年   1612篇
  2007年   1562篇
  2006年   1454篇
  2005年   1303篇
  2004年   1133篇
  2003年   992篇
  2002年   879篇
  2001年   344篇
  2000年   302篇
  1999年   267篇
  1998年   185篇
  1997年   159篇
  1996年   142篇
  1995年   125篇
  1994年   96篇
  1993年   104篇
  1992年   140篇
  1991年   154篇
  1990年   127篇
  1989年   156篇
  1988年   142篇
  1987年   116篇
  1986年   111篇
  1985年   107篇
  1984年   90篇
  1983年   64篇
  1982年   51篇
  1981年   60篇
  1980年   50篇
  1979年   51篇
  1975年   53篇
  1972年   46篇
  1936年   47篇
  1933年   53篇
  1932年   50篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
A detailed study comparing the distribution of D2 receptors and tyrosine hydroxylase-immunoreactive fibers in the hippocampus and parahippocampal cortices of the rat, cat, and human was conducted. The distribution of [125I]epidepride binding to D2 receptors along the transverse and longitudinal axes of the hippocampus and parahippocampus differed among the species. In rat hippocampus, the number of sites was highest in septal portions of lacunosum-moleculare of CA1 and stratum moleculare of the subiculum. Virtually no binding to D2 receptors existed in the temporal hippocamps. For the cat hippocampus, the highest binding existed in the inner one-third of the molecular layer of the dentate gyrus (DG). There were also significant numbers of D2 receptors in strata radiatum and oriens of the CA subfields, with almost undetectable levels in lacunosum moleculare and subiculum. The number of sites was higher in the septal than temporal hippocampus. In the human hippocampus, highest binding was observed in the molecular layer of DG and the subiculum, with lower levels in strata oriens and lacunosum-moleculare of CA3, and very low binding in CA1. The histochemical demonstration of the pattern of mossy fibers revealed an organization complementary to that of D2 receptors in cat and human. In none of the species was there significant expression of D2 receptors in the entorhinal cortex, except in the caudal extreme of this region in the rat. In that region a trilaminar pattern was exhibited that continued into the perirhinal cortex. A trilaminar pattern of D2 receptor expression was observed in the perirhinal cortex of all species, with the highest values in the external and deep laminae and low expression in the middle laminae. The organization of dopamine fibers was assessed by comparing the distribution of tyrosine hydroxylase-positive and dopamine β-hydroxylase-immunoreactive fibers in these same regions. It revealed consistent mismatches between the pattern of D2 receptor expression and dopaminergic innervation in all three species. The implications for this mismatch are discussed. It is hypothesized that the distribution of D2 receptors, and not of dopamine fibers, determines what neural systems dopamine influences in the hippocampal complex. © 1994 Wiley-Liss, Inc.  相似文献   
62.
63.
64.
The effects of recombinant human erythropoietin (rhEPO, RecormonR, CAS 122312-54-3) on the differential leucocyte counts and platelets of rabbits were investigated after the repeated application of a single dose of rhEPO. Therefore, 150 IU rhEPO (n = 5), 300 IU rhEPO (n = 6), or 600 IU rhEPO (n = 5) per animal was injected once on three separate occasions with an interval of 5–6 weeks between each injection. Six animals were used to study the potential effect of the solvent alone.rhEPO showed a significant time effect on the differential leucocyte counts and platelets of rabbits. The decrease in total white blood cells count (WBC) on the third, fourth and sixth day after rhEPO administration was due to a decrease in lymphocytes. These results support the hypothesis that the enhanced demand of one cell line leads to a down-modulation of the production of other cell line(s).  相似文献   
65.
The principles of promoting autonomy and independence underpin many approaches to improving the quality of nursing care for older people in whatever setting, and are in line with wider developments in health care such as the Patient's Charter. However, these concepts require careful definition if nursing practices which might promote autonomy and independence are to be identified. Although the generalizability of the research-based literature in this field is limited by a focus upon older people in continuing-care settings, a review of the literature found a number of indicators associated with attempts to promote patient autonomy and independence. These were grouped into the following categories: systems of care delivery which promote comprehensive individualized assessment and multidisciplinary care planning; attempts to encourage patients/clients to participate in decisions about their care; patterns of communication which avoid exerting power and control over patients/clients and attempts to modify the environment to promote independence and minimize risk. It is suggested that the review identifies a number of principles for nursing practice which can be applied in a range of care settings in order to promote the autonomy and independence of older people.  相似文献   
66.
We report on a woman with a an 8-year history of multiple system atrophy with predominance of parkinsonism who developed jaw-locking oromandibular dystonia within hours after insertion of ill-fitting dentures. Dystonia spread rapidly to involve other facial muscles and the larynx causing stridor with respiratory failure necessitating crush intubation.  相似文献   
67.
68.
69.
Anatomically, the thigh is well covered by soft tissue in the form of the muscles surrounding the shaft. In the assessment of the severity of an injury, not only the obvious skin wound but also the mechnism of the trauma has to be considered. The extent and severity of the soft tissue damage cannot usually be fully established until later in the course of treatment, when necrosis of the skin, the subcutaneous fat and the musculature and also compartment syndrome or a secondary disturbance of perfusion may become obvious. Therefore, when extensive soft tissue injuries are present, following the primary débridement, a repeat wound débridement after 24–48 hours is generally indicated. Only after consolidation of the wounds and the successful treatment of any infection is definitive soft tissue reconstruction performed. The main danger in the treatment of soft tissue injuries of the thigh is underestimation of their total extent.  相似文献   
70.
We report on a 26-year-old female affected by Noonan syndrome (NS), a congenital disorder characterized by various phenotypic features and congenital anomalies) associated with a variety of autoimmune diseases, including systemic lupus erythematosus, celiac disease, and Hashimoto thyroiditis. Autoimmunity is seldom described in NS and the association between this congenital disease and three autoimmune disorders has not been previously reported. Should the occurrence of autoimmune disorders in NS be confirmed, a relevant clinical and laboratory evaluation of NS patients should be performed in order to clarify whether the immune system involvement represents only an occasional event or is a feature of the disease.  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