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   234664篇
  免费   22314篇
  国内免费   16731篇
耳鼻咽喉   2065篇
儿科学   2404篇
妇产科学   3243篇
基础医学   28196篇
口腔科学   4175篇
临床医学   32654篇
内科学   34119篇
皮肤病学   2382篇
神经病学   12939篇
特种医学   8836篇
外国民族医学   144篇
外科学   23212篇
综合类   39022篇
现状与发展   57篇
一般理论   20篇
预防医学   14243篇
眼科学   7158篇
药学   24618篇
  216篇
中国医学   13715篇
肿瘤学   20291篇
  2024年   593篇
  2023年   3406篇
  2022年   8368篇
  2021年   12246篇
  2020年   9196篇
  2019年   8055篇
  2018年   8598篇
  2017年   7612篇
  2016年   7128篇
  2015年   11015篇
  2014年   13443篇
  2013年   11638篇
  2012年   17354篇
  2011年   19353篇
  2010年   11552篇
  2009年   9108篇
  2008年   12225篇
  2007年   12087篇
  2006年   12221篇
  2005年   12272篇
  2004年   7738篇
  2003年   7410篇
  2002年   6188篇
  2001年   5441篇
  2000年   5743篇
  1999年   6002篇
  1998年   3708篇
  1997年   3645篇
  1996年   2948篇
  1995年   2708篇
  1994年   2240篇
  1993年   1438篇
  1992年   1962篇
  1991年   1653篇
  1990年   1337篇
  1989年   1115篇
  1988年   1046篇
  1987年   890篇
  1986年   736篇
  1985年   545篇
  1984年   337篇
  1983年   247篇
  1982年   150篇
  1981年   145篇
  1980年   112篇
  1979年   143篇
  1978年   49篇
  1977年   53篇
  1975年   57篇
  1974年   56篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
61.
62.
世界各地均在加速推进教育信息化建设,但快速的 e 化发展,会因民众自身条件的不同造成不均的现象,并导致阶层、地域及群体间的“数位落差”。数位落差是世界各地政府在推动信息化的过程中都无法避免的,大陆地区也不例外。由于中国台湾地区具有与大陆相似的文化氛围和相近的教育发展历史,该文通过梳理和解读中国台湾地区现有的缩减数位落差政策,以期为大陆地区研制专门化政策来应对当前挑战,推进教育信息化的均衡发展提供借鉴。  相似文献   
63.
随着腔镜技术的进一步发展以及微创理念应用于结直肠外科疾病的诊治中,结直肠相关疾病的诊治发生了翻天覆地的变化。由传统的经腹手术到腹腔镜手术、经自然腔道手术,再到经自然腔道取标本手术(NOSES),结直肠疾病的外科诊治在微创领域取得了巨大成果。NOSES技术是目前结直肠外科在微创领域前沿的手术方式之一,它通过经直肠、阴道取标本来避免了腹壁的辅助取标本切口,从而将结直肠外科手术进一步微创化。NOSES技术集传统腹腔镜手术的优势与现代微创外科的理念于一体,它在确保手术效果的基础上集中体现了微创、加速康复外科、功能外科、"无疤"等理念的特点。本文主要就国内外各中心开展NOSES技术在结直肠外科诊治开展中的相关经验、心得和体会进行综述。  相似文献   
64.
65.
Advancing nanomedicines from concept to clinic requires integration of new science with traditional pharmaceutical development. The medical and commercial success of nanomedicines is greatly facilitated when those charged with developing nanomedicines are cognizant of the unique opportunities and technical challenges that these products present. These individuals must also be knowledgeable about the processes of clinical and product development, including regulatory considerations, to maximize the odds for successful product registration. This article outlines these topics with a goal to accelerate the combination of academic innovation with collaborative industrial scientists who understand pharmaceutical development and regulatory approval requirements—only together can they realize the full potential of nanomedicines for patients.  相似文献   
66.
Background:Gastrointestinal complications and malnutrition are common problems that affect postoperative rehabilitation and survival of patients with esophageal cancer. Evidence has shown that probiotics have a positive effect on improving gastrointestinal complications and nutritional status of patients with esophageal cancer after surgery, but there is a lack of prospective studies on this topic. We designed this prospective randomized controlled trial to evaluate the effects of probiotics on gastrointestinal complications and nutritional status in patients with postoperative esophageal cancer.Methods:This is a prospective, randomized, double-blind, placebo-controlled trial. It was approved by the Clinical Research Ethics Committee of our hospital. 192 patients will be randomly divided into probiotics group and the placebo group in a 1:1 ratio. After operation, probiotics and placebo will be given orally for 8 weeks. The indexes of nutritional status and incidence of digestive tract complications will be recorded and the data will be analyzed by SPSS 18.0 software.Discussion:This study will evaluate the effect of probiotics on gastrointestinal complications and nutritional status of postoperative patients with esophageal cancer. The results of this study will provide clinical basis for the use of probiotics in postoperative treatment of esophageal cancer.Trial registration:OSF Registration number: D DOI 10.17605/OSF.IO/QHW86  相似文献   
67.
miR-30c has been acknowledged as a tumor suppressor in various human cancers, such as ovarian cancer, gastric cancer, and prostate cancer. However, the role of miR-30c in glioblastoma (GBM) needs to be investigated. In our study, we found that the expression of miR-30c was significantly downregulated in GBM tissues and cell lines. We found that overexpression of miR-30c inhibited cellular proliferation of GBM cells in vitro and in vivo. More GBM cells were arrested in the G0 phase after miR-30c overexpression. Moreover, we showed that miR-30c overexpression suppressed the migration and invasion of GBM cells. Mechanistically, we found that SOX9 was a direct target of miR-30c in GBM cells. Overexpression of miR-30c inhibited the mRNA and protein levels of SOX9 in GBM cells. Moreover, there was a negative correlation between the expression of miR-30c and SOX9 in GBM tissues. Finally, we showed that restoration of SOX9 in GBM cells reversed the proliferation, migration, and invasion of GBM cells transfected with miR-30c mimic. Collectively, our results demonstrated that miR-30c suppressed the proliferation, migration, and invasion of GBM cells via targeting SOX9.  相似文献   
68.
69.
1. To investigate Genkwa Flos hepatotoxicity, a cell metabolomics strategy combined with serum pharmacology was performed on human HL-7702 liver cells in this study.

2. Firstly, cell viability and biochemical indicators were determined and the cell morphology was observed to confirm the cell injury and develop a cell hepatotoxicity model. Then, with the help of cell metabolomics based on UPLC-MS, the Genkwa Flos group samples were completely separated from the blank group samples in the score plots and seven upregulated as well as two down-regulated putative biomarkers in the loading plot were identified and confirmed. Besides, two signal molecules and four enzymes involved in biosynthesis pathway of lysophosphatidylcholine and the sphingosine kinase/sphingosine-1-phosphate pathway were determined to investigate the relationship between Genkwa Flos hepatotoxicity and these two classic pathways. Finally, the metabolic pathways related to specific biomarkers and two classic metabolic pathways were analyzed to explain the possible mechanism of Genkwa Flos hepatotoxicity.

3. Based on the results, lipid peroxidation and oxidative stress, phospholipase A2/lysophosphatidylcholine pathway, the disturbance of sphingosine-1-phosphate metabolic profile centered on sphingosine kinase/sphingosine-1-phosphate pathway and fatty acid metabolism might be critical participators in the progression of liver injury induced by Genkwa Flos.  相似文献   

70.
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