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   350874篇
  免费   9459篇
  国内免费   590篇
耳鼻咽喉   4047篇
儿科学   11770篇
妇产科学   6924篇
基础医学   40076篇
口腔科学   8645篇
临床医学   23623篇
内科学   74198篇
皮肤病学   6253篇
神经病学   30697篇
特种医学   12848篇
外国民族医学   2篇
外科学   50808篇
综合类   3364篇
一般理论   53篇
预防医学   34449篇
眼科学   6562篇
药学   21485篇
中国医学   1571篇
肿瘤学   23548篇
  2023年   1072篇
  2022年   1785篇
  2021年   5110篇
  2020年   2603篇
  2019年   4698篇
  2018年   27710篇
  2017年   20641篇
  2016年   22708篇
  2015年   5177篇
  2014年   6707篇
  2013年   8985篇
  2012年   19679篇
  2011年   34253篇
  2010年   25690篇
  2009年   17098篇
  2008年   29723篇
  2007年   32432篇
  2006年   11091篇
  2005年   12592篇
  2004年   12620篇
  2003年   12888篇
  2002年   10374篇
  2001年   4790篇
  2000年   5451篇
  1999年   4210篇
  1998年   1260篇
  1997年   1026篇
  1996年   781篇
  1995年   731篇
  1994年   592篇
  1993年   453篇
  1992年   1610篇
  1991年   1397篇
  1990年   1289篇
  1989年   1026篇
  1988年   889篇
  1987年   808篇
  1986年   802篇
  1985年   712篇
  1984年   522篇
  1983年   455篇
  1979年   457篇
  1978年   331篇
  1974年   416篇
  1973年   404篇
  1972年   344篇
  1971年   367篇
  1970年   352篇
  1969年   373篇
  1968年   327篇
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
21.
Lasers in Medical Science - Studies reported the harmful effects of 2,4-D on body tissues, provoking changes in the anatomy and physiology of the kidneys, liver, and testicles. Thus, the objective...  相似文献   
22.
23.
24.
25.
The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous.  相似文献   
26.
27.
Hailey–Hailey disease (HHD), also known as benign familial pemphigus, is an autosomal dominant skin condition that affects the adhesion of epidermal keratinocytes. Although the initial manifestation of flaccid vesicles on erythematous or normal skin in flexure sites frequently goes unnoticed, large, macerated, exudative plaques of superficial erosions with crusting are observed at the time of diagnosis. There is no specific treatment for HHD, and most cases are symptomatically supported. However, infrared laser ablation has been somewhat helpful. We present a case successfully treated with fractional CO2 laser showing a long-term favourable outcome and no adverse effects. Thus, this modality could be an alternative to full ablation for this condition.  相似文献   
28.
29.
30.
Chlorpyrifos is the most used insecticide in Argentina. Cnesterodon decemmaculatus is a widely distributed, endemic fish from Neotropical America. It attains high densities in the shallow water assemblages of Argentina and Brazil. The aim of this study was to assess the acute toxicity of chlorpyrifos to C. decemmaculatus. The mean 96-h LC50 of three independent determinations was 105.3 (±?3.1) μg/L. Sublethal effects were observed. Swimming behavioral changes at each chlorpyrifos exposure concentration were reported. C. decemmaculatus represents a good model for ecotoxicological risk assessment.  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