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   34439篇
  免费   3175篇
  国内免费   2559篇
耳鼻咽喉   391篇
儿科学   396篇
妇产科学   367篇
基础医学   4045篇
口腔科学   580篇
临床医学   4774篇
内科学   4993篇
皮肤病学   367篇
神经病学   1986篇
特种医学   1266篇
外国民族医学   24篇
外科学   3192篇
综合类   6464篇
现状与发展   11篇
预防医学   2122篇
眼科学   1107篇
药学   3512篇
  26篇
中国医学   1871篇
肿瘤学   2679篇
  2024年   125篇
  2023年   674篇
  2022年   1583篇
  2021年   1821篇
  2020年   1413篇
  2019年   1207篇
  2018年   1250篇
  2017年   1189篇
  2016年   1024篇
  2015年   1578篇
  2014年   1941篇
  2013年   1687篇
  2012年   2636篇
  2011年   2736篇
  2010年   1625篇
  2009年   1306篇
  2008年   1570篇
  2007年   1677篇
  2006年   1677篇
  2005年   1697篇
  2004年   1060篇
  2003年   1011篇
  2002年   883篇
  2001年   786篇
  2000年   810篇
  1999年   937篇
  1998年   604篇
  1997年   669篇
  1996年   496篇
  1995年   416篇
  1994年   356篇
  1993年   206篇
  1992年   277篇
  1991年   247篇
  1990年   204篇
  1989年   185篇
  1988年   173篇
  1987年   133篇
  1986年   101篇
  1985年   77篇
  1984年   34篇
  1983年   20篇
  1982年   27篇
  1981年   15篇
  1980年   8篇
  1979年   9篇
  1965年   2篇
  1940年   3篇
  1935年   2篇
  1934年   1篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
993.
目的 分析2012年和2014年流行性腮腺炎(腮腺炎)流行特征,探讨山东省2剂次含腮腺炎成分疫苗(MuCV)接种的预防效果。方法 在一定模型假定基础上,结合相关文献设置合理参数,构建状态空间模型,利用迭代滤波对模型进行参数估计。结果 2012年和2014年托幼及学生人群基础再生数(R0)分别为4.49(95%CI:4.30~4.67)和2.50(95%CI:2.38~2.61)。结论 状态空间模型能够很好地描述腮腺炎传播过程;山东省实行2剂MuCV能够有效降低腮腺炎在人群中的传播;托幼和学生是实现腮腺炎进一步控制的重要人群,应进一步提高2剂次MuCV接种率。  相似文献   
994.
Diffuse large B-cell lymphoma (DLBCL) is the most main subtype in non-Hodgkin lymphoma. After chemotherapy, about 30% of patients with DLBCL develop resistance and relapse. This study was to identify potential therapeutic drugs for DLBCL using the bioinformatics method. The differentially expressed genes (DEGs) between DLBCL and non-cancer samples were downloaded from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO). Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of DEGs were analyzed using the Database for Annotation, Visualization, and Integrated Discovery. The R software package (SubpathwayMiner) was used to perform pathway analysis on DEGs affected by drugs found in the Connectivity Map (CMap) database. Protein–protein interaction (PPI) networks of DEGs were constructed using the Search Tool for the Retrieval of Interacting Genes online database and Cytoscape software. In order to identify potential novel drugs for DLBCL, the DLBCL-related pathways and drug-affected pathways were integrated. The results showed that 1927 DEGs were identified from TCGA and GEO. We found 54 significant pathways of DLBCL using KEGG pathway analysis. By integrating pathways, we identified five overlapping pathways and 47 drugs that affected these pathways. The PPI network analysis results showed that the CDK2 is closely associated with three overlapping pathways (cell cycle, p53 signaling pathway, and small cell lung cancer). The further literature verification results showed that etoposide, rinotecan, methotrexate, resveratrol, and irinotecan have been used as classic clinical drugs for DLBCL. Anisomycin, naproxen, gossypol, vorinostat, emetine, mycophenolic acid and daunorubicin also act on DLBCL. It was found through bioinformatics analysis that paclitaxel in the drug-pathway network can be used as a potential novel drug for DLBCL.  相似文献   
995.
996.
Current pemetrexed/platinum chemotherapy does not produce a satisfactory therapeutic response in advanced lung cancer patients. The aim of this study was to determine whether the administration of gefitinib, a tyrosine kinase inhibitor (TKI), intercalated with pemetrexed/platinum could improve the efficacy in chemotherapy-naïve patients with advanced non-squamous NSCLC without subsequent gefitinib maintenance therapy. Treatment-naïve patients with stage IIIB or IV NSCLC were randomly assigned to receive pemetrexed (500 mg/m2 d1) and either cisplatin (75 mg/m2 d1) or carboplatin (AUC = 5 d1) plus gefitinib (250 mg/d on days 3 to 16 of a 3-week cycle) (PC-G) or pemetrexed–platinum (PC) alone. Randomization was stratified according to the tobacco smoking status and EGFR mutational status of the patients. The primary endpoint was the non-progression rate (NPR) at 12 weeks. Secondary endpoints included progression-free survival (PFS), overall response rate (ORR), overall survival (OS), and biosafety. The NPR at 12 weeks was 84.5% for the PC-G treatment arm and 83.1% for the PC treatment arm (P = 0.87). Median PFS was 7.9 months for the PC-G arm and 7.0 months for the PC arm (P = 0.57). The ORR was 50.0% for the PC-G arm and 47.4% for the PC arm (P = 0.78). Median survival was 25.4 mo for the PC-G arm and 20.8 mo for the PC arm (P = 0.54). The incidence of adverse events was similar between the two treatment arms, except for a higher incidence of skin rash with PC-G. Predefined subgroup analyses demonstrated that PC-G significantly increased the PFS compared with the PC regimen in patients with EGFR mutations (P = 0.017). Although gefitinib intercalated with pemetrexed/platinum chemotherapy did not improve the NPR at 12 weeks compared with chemotherapy, an improvement in the PFS for the intercalated treatment arm was seen in the subgroup of patients with EGFR mutations.  相似文献   
997.
998.
This review systematically assessed those studies investigating the association between air pollution and birth outcomes using land use regression (LUR) models for exposure assessment. Fifty-four studies were identified which were published between 2007 and 2019. Most of these were conducted in America, Spain and Canada, while only five were conducted in China. One hundred and ninety-seven LUR models were developed for different pollutants. The main pollutants that these studies assessed were NO2 and PM2.5, and the main pregnancy outcomes investigated were preterm birth (PTB), small for gestational age (SGA) and birth weight. Studies consistently found that NO2 exposure during pregnancy was associated with reduced fetal growth and development. The effect of NO2 on other adverse pregnancy outcomes is unclear. In addition, it was found that increased PM2.5 (aerodynamic equivalent diameter ≤ 2.5 um) exposure during pregnancy reduced birth weight. The effect of PM2.5 on other adverse pregnancy outcomes is also unclear. The relationship between other pollutants and adverse pregnancy outcomes is uncertain based on the existing research. Exposure assessment with LUR modeling has been widely used in Europe and North America, but used less in China. Future studies are recommended to use LUR modeling for individual exposure evaluation in China to better characterize the relationship between air pollution and adverse pregnancy outcomes. In addition, further research is required given that a lot of the associations looked at in the review were inconclusive.  相似文献   
999.
1000.
目的构建护理人员薪酬管理体系。方法应用文献研究、专家访谈、Delphi、层次分析法、调查性研究、因子分析、信息化等技术研究方法,共分为5个阶段9个步骤构建了护理人员薪酬管理体系。结果薪酬管理体系由基本工资、绩效、福利津贴3部分构成,其中的绩效工资以护理单元为考核单位从3个方面进行量化考核。结论护理人员薪酬管理体系的构成合理,研究方法适用,研究结果可信度高,充分激发了护理人员的积极性,实现了效益最大化的管理理念。  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