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   175958篇
  免费   942篇
  国内免费   5篇
耳鼻咽喉   1127篇
儿科学   6640篇
妇产科学   3099篇
基础医学   16520篇
口腔科学   1599篇
临床医学   12330篇
内科学   30808篇
皮肤病学   676篇
神经病学   16417篇
特种医学   8941篇
外科学   29015篇
综合类   2311篇
预防医学   18046篇
眼科学   2817篇
药学   9428篇
中国医学   625篇
肿瘤学   16506篇
  2021年   32篇
  2019年   37篇
  2018年   21943篇
  2017年   17367篇
  2016年   19528篇
  2015年   899篇
  2014年   800篇
  2013年   760篇
  2012年   6947篇
  2011年   20998篇
  2010年   18796篇
  2009年   11496篇
  2008年   19474篇
  2007年   21674篇
  2006年   522篇
  2005年   2153篇
  2004年   3357篇
  2003年   4327篇
  2002年   2457篇
  2001年   300篇
  2000年   443篇
  1999年   193篇
  1998年   212篇
  1997年   216篇
  1996年   97篇
  1995年   112篇
  1994年   107篇
  1993年   67篇
  1992年   92篇
  1991年   130篇
  1990年   155篇
  1989年   119篇
  1988年   103篇
  1987年   91篇
  1986年   58篇
  1985年   66篇
  1984年   62篇
  1983年   50篇
  1982年   29篇
  1980年   45篇
  1974年   22篇
  1970年   27篇
  1969年   26篇
  1968年   26篇
  1938年   60篇
  1937年   25篇
  1935年   22篇
  1934年   30篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.

Background  

It has been observed that ras-transformed cell lines in culture have a higher phosphatidylcholine (PC) biosynthesis rate as well as higher PC-degradation rate (increased PC-turnover) than normal cells. In correspondence to these findings, the concentrations of the PC-degradation product lyso-phosphatidylcholine (LPC) in cancer patients were found to be decreased. Our objective was the systematic investigation of the relationship between LPC and inflammatory and nutritional parameters in cancer patients. Therefore, plasma LPC concentrations were assessed in 59 cancer patients and related to nutritional and inflammatory parameters. To determine LPC in blood plasma we developed and validated a HPTLC method.  相似文献   
95.
96.
A rare case of a thrombus in the inferior vena cava (IVC) after retroperitoneal lymphadenectomy for a testicular tumor is reported. A computed tomograph performed after the operation incidentally showed a filling defect in the IVC. However, it was impossible to decide whether the defect was due to an ordinary or a neoplastic thrombus. For this reason, a thrombectomy was performed, and postoperatively it was diagnosed as an ordinary thrombus. The cause of thrombi found only in the IVC is reviewed and the indication for thrombectomy is discussed.  相似文献   
97.
The depth and extent of the invasion of the skull base by a tumor are the most critical information for successful en bloc resection of the tumor. The only means available for the evaluation of these factors are CT or MRI images. In order to clarify the ability of these imaging modes to delineate the invasion of the skull base, preoperative images of ten patients who underwent en bloc resection of skull base tumors at Kobe University Hospital were compared with the histopathological findings of the resected specimens. CT proved to be superior to MRI for evaluating bone destruction of the skull base. On the other hand, MRI provided more useful information about intracranial invasion than CT. As a hypertrophic linear shadow on Gd-enhanced MRI represented dural invasion or thickened dura mater adjacent to the tumor, this technique should be taken into consideration to determine the dural resection. We concluded that preoperative evaluation of the depth of skull base invasion by both CT and Gd-enhanced MRI is essential for planning complete tumor resection.  相似文献   
98.
99.
Summary To investigate the distribution of possible novel mutations from parkin gene in variant subset of patients with Parkinson’s disease (PD) in China and explore whether parkin gene plays an important role in the pathogenesis of PD, 70 patients were divided into early-onset group and late-onset group; 70 healthy subjects were included as controls. Genomic DNA from 70 normal controls and from those of PD patients were extracted from peripheral blood leukocytes by using standard procedures. Mutations of parkin gene (exon 1–12) in all the subjects were screened by PCR-single strand conformation polymorphism (SSCP), and further sequencing was performed in the samples with abnormal SSCP results, in order to confirm the mutation and its location. A new missense mutation Gly284Arg in a patient and 3 abnormal bands in SSCP electrophoresis from samples of another 3 patients were found. All the DNA variants were sourced from the samples of the patients with early-onset PD. It was concluded that Parkin point mutation also partially contributes to the development of early-onset Parkinson’s disease in Chinese. WANG Tao, male, born in 1961, Associate Professor This work was supported by grants from the key program of the special scientific project of Scientific & Technologic Agency of Hubei Province (Serial No. 2001AA308B01) and the Hygienic Research Project of Hygienic Agency of Hubei province (Serial No. WJ 01529).  相似文献   
100.
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