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   5868篇
  免费   422篇
  国内免费   18篇
耳鼻咽喉   91篇
儿科学   191篇
妇产科学   185篇
基础医学   677篇
口腔科学   138篇
临床医学   704篇
内科学   1030篇
皮肤病学   66篇
神经病学   472篇
特种医学   135篇
外科学   674篇
综合类   70篇
一般理论   7篇
预防医学   654篇
眼科学   101篇
药学   409篇
中国医学   7篇
肿瘤学   697篇
  2023年   27篇
  2022年   47篇
  2021年   119篇
  2020年   95篇
  2019年   112篇
  2018年   150篇
  2017年   124篇
  2016年   112篇
  2015年   151篇
  2014年   201篇
  2013年   292篇
  2012年   355篇
  2011年   407篇
  2010年   249篇
  2009年   190篇
  2008年   369篇
  2007年   371篇
  2006年   362篇
  2005年   328篇
  2004年   315篇
  2003年   295篇
  2002年   277篇
  2001年   105篇
  2000年   70篇
  1999年   93篇
  1998年   85篇
  1997年   73篇
  1996年   60篇
  1995年   64篇
  1994年   49篇
  1993年   44篇
  1992年   54篇
  1991年   68篇
  1990年   49篇
  1989年   51篇
  1988年   44篇
  1987年   42篇
  1986年   27篇
  1985年   35篇
  1984年   45篇
  1983年   33篇
  1982年   28篇
  1981年   18篇
  1980年   20篇
  1979年   16篇
  1978年   15篇
  1976年   18篇
  1975年   12篇
  1974年   14篇
  1973年   15篇
排序方式: 共有6308条查询结果,搜索用时 15 毫秒
91.
Chromosomal aberrations (CAs) in human peripheral blood lymphocytes (PBL) measured with the conventional cytogenetic assay have been used for human biomonitoring of genotoxic exposure for decades. CA frequency in peripheral blood is a marker of cancer susceptibility. Previous studies have shown associations between genetic variants in metabolic pathway, DNA repair and major mitotic checkpoint genes and CAs. We conducted a genome-wide association study on 576 individuals from the Czech Republic and Slovakia followed by a replication in two different sample sets of 482 (replication 1) and 1288 (replication 2) samples. To have a broad look at the genetic susceptibility associated with CA frequency, the sample sets composed of individuals either differentially exposed to smoking, occupational/environmental hazards, or they were untreated cancer patients. Phenotypes were divided into chromosome- and chromatid-type aberrations (CSAs and CTAs, respectively) and total chromosomal aberrations (CAtot). The arbitrary cutoff point between individuals with high and low CA frequency was 2% for CAtot and 1% for CSA and CTA. The data were analyzed using age, sex, occupation/cancer and smoking history as covariates. Altogether 11 loci reached the P-value of 10−5 in the GWAS. Replication 1 supported the association of rs1383997 (8q13.3) and rs2824215 (21q21.1) in CAtot and rs983889 (5p15.1) in CTA analysis. These loci were found to be associated with genes involved in mitosis, response to environmental and chemical factors and genes involved in syndromes linked to chromosomal abnormalities. Identification of new genetic variants for the frequency of CAs offers prediction tools for cancer risk in future. Environ. Mol. Mutagen. 60:17–28, 2019. © 2018 Wiley Periodicals, Inc.  相似文献   
92.
93.
The Young Forum of the German Society for Thoracic and Cardiovascular Surgery (GSTCVS) was founded during the 41st annual meeting of the German Society for Thoracic and Cardiovascular Surgery in Freiburg in 2012. The idea was to establish a stronger representation of the needs and problems of young colleagues within the GSTCVS and to improve the communication between residents, students and representatives of the GSTCVS. The aims are to improve residency programs in Germany in general and in particular, to improve the clinical and scientific exchange of residents in Germany, Europe and foreign countries. Attempts will also be made to find solutions that could lead to a better work-life balance in cardiothoracic surgery and therefore make this field more attractive for young physicians.  相似文献   
94.

Background  

Atrial fibrillation (AF) is the most common sustained dysrhythmia and appears to be an independent predictor of sudden cardiac death. The irregular ventricular rhythm contains both linear and non-linear patterns; however, it remains unclear whether vagally mediated effects are present within these patterns.  相似文献   
95.
96.
97.
98.
Epichloë festucae is an endophytic fungus that infects systemically the aerial tissues of the host grass Festuca rubra. This fungus is transmitted vertically from the mother plant to seeds. Hypothetically, the presence of E. festucae could affect the infection of a plant by other fungal species. This could occur if E. festucae metabolites produced in planta interfere negatively with other fungal infections; or alternatively, if the modulation of plant defenses by the endophyte favour further fungal infections. We have analyzed the presence of culturable non-systemic endophytes in plants of F. rubra infected (E+) and not infected (E?) by E. festucae in two subarctic habitats, meadows and riverbanks in Northern Finland. The observed non-systemic endophyte infection frequencies were similar among E+ and E? plants from riverbanks, and E+ plants from meadows. In contrast to these, the infection frequency was significantly lower in E? plants from meadows. This result suggests that the presence of E. festucae is not a main factor determining the presence of non-systemic endophytes in plants. Instead, plant genetic characteristics related to compatibility with E. festucae and other endophytes in the more stable meadow populations might play a role in these fungus–fungus–plant interactions. As a result of the survey, 18 different taxa of non-systemic endophytes were identified in plants of F. rubra. All were ascomycetes except for one basidiomycete. Three endophytic taxa could not be ascribed to a genus, but sequence data indicated that they were conspecific with other unidentified endophytes that have been isolated in cold biomes at different locations.  相似文献   
99.
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