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   21551篇
  免费   1407篇
  国内免费   108篇
耳鼻咽喉   347篇
儿科学   521篇
妇产科学   482篇
基础医学   2726篇
口腔科学   628篇
临床医学   1748篇
内科学   5573篇
皮肤病学   486篇
神经病学   1804篇
特种医学   479篇
外科学   3501篇
综合类   138篇
一般理论   8篇
预防医学   1334篇
眼科学   630篇
药学   1134篇
  1篇
中国医学   47篇
肿瘤学   1479篇
  2023年   155篇
  2022年   311篇
  2021年   724篇
  2020年   381篇
  2019年   642篇
  2018年   794篇
  2017年   461篇
  2016年   520篇
  2015年   642篇
  2014年   860篇
  2013年   1069篇
  2012年   1814篇
  2011年   1845篇
  2010年   966篇
  2009年   906篇
  2008年   1455篇
  2007年   1494篇
  2006年   1379篇
  2005年   1254篇
  2004年   1099篇
  2003年   935篇
  2002年   864篇
  2001年   173篇
  2000年   173篇
  1999年   196篇
  1998年   201篇
  1997年   150篇
  1996年   127篇
  1995年   134篇
  1994年   116篇
  1993年   115篇
  1992年   114篇
  1991年   68篇
  1990年   61篇
  1989年   68篇
  1988年   53篇
  1987年   54篇
  1986年   59篇
  1985年   44篇
  1984年   60篇
  1983年   51篇
  1982年   62篇
  1981年   58篇
  1980年   43篇
  1979年   37篇
  1978年   32篇
  1977年   31篇
  1976年   28篇
  1974年   22篇
  1973年   23篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
73.

Objectives  

This study was designed to assess the prevalence of adverse drug reactions (ADRs) in the internal medicine wards of two teaching Hospitals, identify the most common ADRs, the principal medications involved, and determine the risk factors implicated in the occurrence of such ADRs.  相似文献   
74.
75.
: The use of needle-localization breast biopsy (NLBB) for the early diagnosis of breast cancer is common. The therapeutic adequacy of tumor-free margins following NLBB is unknown. We hypothesized that the presence of residual tumor after reexcision (mastectomy, tylectomy, or quadrantectomy) does not depend on the margin status following NLBB. : Retrospective cohort analysis was performed on 890 consecutive NLBBs executed between January 1990 and June 1994. Patients with invasive breast neoplasia were divided into two groups based on the tumor margins after NLBB. Group 1 were the women with positive margins, and group 2 had negative margins. Breast specimens after reexcision were reviewed for evidence of residual invasive carcinoma. : Invasive neoplasia was present in 107 patients (12%). Surgical margins and definitive records of care were avaliable for 96 of them (90%). All 45 patients in group 1 and 38 (75%) of 51 patients in group 2 underwent reexcision of the initial biopsy site (P = 0.36). Residual invasive carcinoma was present in 10 patients (22%) in group 1 and 3 (8%) in group 2 (P = 0.13). : Invasive breast neoplasia diagnosed by NLBB requires reexcision regardless of tumor margins to achieve complete local surgical eradication of tumor.  相似文献   
76.
77.
Maternal group B streptococcal infection is an uncommon entity. Herein we describe a case of a 27-year-old-woman who presented life-threateniing group B streptococcus meningitis with an ectopic cervical pregnancy. No other infectious focus have been found. To our knowledge this is the first time that this association has been reported.  相似文献   
78.
Summary An infant with pulmonary arteriovenous fistulas is described. Surgical ligation of the fistulas and limited resection of paraenchyma from the right lung was followed at 11 months of age, by successful steel coil embolization of residual fistulas.  相似文献   
79.
In search of genes possibly involved in the regulation of hindbrain segmentation, we have isolated mouse cDNA clones corresponding to putative protein kinase genes by polymerase chain reaction amplification of cDNA from 9.5-day-old embryo hindbrains. In situ hybridization analysis revealed that one of these genes, Sek, was expressed in an alternating segment-restricted pattern in the developing hindbrain. Isolation and analysis of Sek cDNAs covering the entire coding sequence indicated that Sek encoded a putative receptor protein tyrosine kinase, belonging to the Eph family. These data are consistent with a role of the Sek gene product in a signal transduction process involved in pattern formation in the hindbrain.  相似文献   
80.
The pulmonary flow pattern was analysed by pulsed Doppler in 77 normal neonates, at < 48 hours (36 subjects), 49 to 96 hours (25 subjects) and 97 to 148 hours (16 subjects). From the flow velocity spectrum, using an built in computer system, the acceleration time and the ejection time were measured, and the ratio was calculated. This ratio was 0.24 +/- 0.08 in the subjects within 48 hours whereas this ratio was 0.53 +/- 0.11 in the subjects above 97 hours; thus the ratio increased with age. We noticed that the ratio obtained from the pulsed Doppler is useful in assessing the pulmonary vascular status, even in neonates.  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