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   25885篇
  免费   1300篇
  国内免费   66篇
耳鼻咽喉   363篇
儿科学   2029篇
妇产科学   610篇
基础医学   2954篇
口腔科学   467篇
临床医学   1403篇
内科学   4823篇
皮肤病学   986篇
神经病学   1136篇
特种医学   962篇
外科学   3889篇
综合类   916篇
一般理论   10篇
预防医学   1275篇
眼科学   1312篇
药学   2118篇
中国医学   140篇
肿瘤学   1858篇
  2023年   147篇
  2022年   377篇
  2021年   729篇
  2020年   406篇
  2019年   478篇
  2018年   687篇
  2017年   452篇
  2016年   657篇
  2015年   582篇
  2014年   917篇
  2013年   1086篇
  2012年   1537篇
  2011年   1633篇
  2010年   891篇
  2009年   706篇
  2008年   1236篇
  2007年   1309篇
  2006年   1127篇
  2005年   1068篇
  2004年   961篇
  2003年   892篇
  2002年   800篇
  2001年   723篇
  2000年   683篇
  1999年   596篇
  1998年   244篇
  1997年   180篇
  1996年   145篇
  1995年   136篇
  1994年   114篇
  1993年   130篇
  1992年   356篇
  1991年   390篇
  1990年   343篇
  1989年   359篇
  1988年   309篇
  1987年   277篇
  1986年   269篇
  1985年   279篇
  1984年   219篇
  1983年   181篇
  1979年   241篇
  1978年   158篇
  1977年   148篇
  1976年   135篇
  1975年   163篇
  1974年   154篇
  1973年   176篇
  1972年   138篇
  1971年   122篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
161.
During the last 4 yr, fine-needle aspiration cytology (FNAC) has been employed in 1,474 patients in 0-15-yr age group at our institute. Of these, 245 patients were found to have malignant disease, including primitive neuroectodermal tumors, hepatoblastoma, nephroblastoma, sarcoma, and epithelial malignancies. Four metastases from medulloblastoma and two each from astrocytoma and meningioma were confirmed without open biopsy. FNAC interpretation was easy when cytologic findings were correlated with relevant clinical and radiologic data.  相似文献   
162.
We report a patient with bilateral microphthalmia with cyst, limb anomalies, and multiple facial malformations. This patient has clinical features similar to Waardenburg ophthalmo-acromelic syndrome, cerebro-oculo-nasal syndrome, and craniotelencephalic dysplasia. Although all of these syndromes are characterized by microphthalmia, the presently reported patient does not have the complete pattern of any of these syndromes, It is possible that he has a previously undescribed syndrome, most closely related to the cerebro-oculo-nasal syndrome with malformations outside the craniofacial region. More case reports are needed to further delineate this possibly new syndrome.  相似文献   
163.
Though a ventriculoperitoneal shunt has been associated with myriads of unusual complications, so has been that with roundworms. A case of a three-year-old boy is presented who had an unusual complication of roundworm migration along the shunt tract that presented as shunt tract infection.  相似文献   
164.
165.
To determine whether liver repopulation with cell transplantation could be of therapeutic value in acute hepatic failure, it is necessary to establish the fate of transplanted hepatocytes. This study used dipeptidyl peptidase IV-deficient F344 rats as recipients to analyse the engraftment and proliferation of transplanted hepatocytes. Syngeneic hepatocytes were transplanted intrasplenically 24-30 h after induction of liver injury by D-galactosamine (GalN). Portosystemic shunting was analysed with 99m-Tc-labelled albumin microspheres. GalN-treated rats showed characteristic hepatic necrosis, inflammation, gamma-glutamyl transpeptidase activation, and regenerative activity, without increased portosystemic shunting (>99% 99m-Tc activity was in the liver in normal and GalN-treated rats). Transplanted cells entered hepatic sinusoids promptly and were observed in liver plates at 48 h. The number of transplanted cells increased in GalN-treated rats by approximately seven-fold (range two- to 12-fold), along with evidence for DNA synthesis between 3 and 14 days after cell transplantation and greater prevalence of larger transplanted cell clusters. These findings indicate that the liver can be safely repopulated in animals with acute liver failure, although the time required for regenesis of plasma membrane structures and proliferation in transplanted hepatocytes will need to be considered in developing therapeutic strategies.  相似文献   
166.
167.
Summary In the attempt to explain the difference in discharge pattern of atrial endings, 131 endings were localized by punctate stimulation, 44 were type A, 77 type B and 10 of an intermediate type. All were located on the dorsal wall of the atria with none on the ventral wall or in the appendage. On the right side, 74% of type A were located in the atria and 63% of type B in or near the veins. On the left side, 67% of type A and 94% of type B were located in or near the veins. Thus, there appeared to be some difference in the location of type A and type B endings on the right side, but on the left side both types of endings were for the most part confined to the venous region. Further, on both right and left sides, these endings were present both in the central part of the atria and in or adjacent to veins. This leads to the suggestion that the difference in discharge patterns is not caused by the location but may be due to some other reasons, e. g. difference of arrangement in the atrial wall with respect to the contractile elements.  相似文献   
168.
The astrocyte is the most abundant cell within the central nervous system (CNS). This cell subserves a multiplicity of important functions that contribute to the process of neural development as well as to the integrity of normal brain function. Adding to the already exhaustive list of capabilities, the astrocyte has now been demonstrated to function as an intracerebral antigen presenting cell. These findings are serving to revise our view of the brain as an immunoprivileged site and perhaps will shed some light on the pathogenetic mechanisms involved in a number of CNS disorders of immune dysregulation. In this review we provide some perspective on the regulatory mechanisms that influence astrocyte immune functions. Specifically, we address the role played by the major histocompatibility complex (MHC) antigens as well as adhesion molecules in the initiation of brain immune responses.  相似文献   
169.
170.
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