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   36595篇
  免费   2742篇
  国内免费   214篇
耳鼻咽喉   353篇
儿科学   886篇
妇产科学   678篇
基础医学   4993篇
口腔科学   714篇
临床医学   4096篇
内科学   7874篇
皮肤病学   658篇
神经病学   3222篇
特种医学   1183篇
外国民族医学   3篇
外科学   5688篇
综合类   856篇
现状与发展   1篇
一般理论   14篇
预防医学   2295篇
眼科学   708篇
药学   2281篇
  1篇
中国医学   146篇
肿瘤学   2901篇
  2023年   276篇
  2022年   504篇
  2021年   900篇
  2020年   616篇
  2019年   907篇
  2018年   1025篇
  2017年   766篇
  2016年   819篇
  2015年   999篇
  2014年   1270篇
  2013年   1648篇
  2012年   2626篇
  2011年   2849篇
  2010年   1479篇
  2009年   1363篇
  2008年   2183篇
  2007年   2162篇
  2006年   2090篇
  2005年   2105篇
  2004年   1930篇
  2003年   1714篇
  2002年   1703篇
  2001年   795篇
  2000年   660篇
  1999年   627篇
  1998年   346篇
  1997年   300篇
  1996年   225篇
  1995年   220篇
  1994年   169篇
  1993年   156篇
  1992年   343篇
  1991年   317篇
  1990年   312篇
  1989年   296篇
  1988年   274篇
  1987年   276篇
  1986年   250篇
  1985年   231篇
  1984年   169篇
  1983年   141篇
  1982年   120篇
  1981年   131篇
  1980年   112篇
  1979年   130篇
  1978年   109篇
  1977年   97篇
  1976年   76篇
  1975年   72篇
  1973年   72篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
The patellar ligament (PL) is an epiphyseal ligament and is part of the extensor complex of the knee. The ligament has gained attention due to its clinical relevance to autograft and tendinopathy. A variety of anatomical variations of the PL such as aplasia, numerical variations, and vascularity are being reported recently by clinicians and anatomists. The aim of this literature was to review the available literature to provide a consensus regarding anatomic variations of the PL, neurovasculature surrounding the PL, histology of the PL, and various aspects of PL measurements with relevance to the surgical considerations and sex and age-related differences. A narrative review of the patellar ligament was performed by conducting a detailed literature search and review of relevant articles. A total of 90 articles on the patellar ligament were included and were categorized into studies based on anatomical variations, neurovasculature, morphometrics, microanatomy, sex and age-related difference, and ACL reconstruction. The anatomical variations and morphometrics of the PL were found to correlate with the frequency of strain injuries, tendinopathy, and efficacy of the PL autograft in anterior cruciate ligament reconstruction. The sex differences in PL measurements and the effect of estrogen on collagen synthesis explained a higher incidence of patellar tendinopathy in women. An awareness of its variations enables careful selection of surgical incisions, thereby avoiding complications related to nerve injury. Accurate knowledge of the PL microanatomy assists in understanding the mechanism of ligament degeneration, rupture, autograft harvesting, and ligamentization results.  相似文献   
7.
We evaluated RNA stability of Ebola virus in EDTA blood and urine samples collected from infected patients and stored in West Africa’s environmental conditions. In blood, RNA was stable for at least 18 days when initial cycle threshold values were <30, but in urine, RNA degradation occurred more quickly.  相似文献   
8.
9.
10.
Phytonutrients extracted from natural resources are receiving much attention among researchers due to their highly antioxidative characteristics which prevent several degenerative diseases including cardiovascular diseases and cancers. These nutraceutical compounds can be used in food, pharmaceutical and cosmetic products as natural antioxidants, preservatives, colourants and functional foods. Huge volume of food wastes are generated from the processing industry and these low-value food residues are rich in various phytonutrients worth recovering. This approach of valorisation reduces the generation of food wastes and is cost-effective considering the cheap feedstock, reduced waste management expenses and high market value of extracted compounds. In light of the health and safety risks posed by commonly used organic extraction solvents derived from the petrochemical industry, there is a need to recover the phytonutrients using green, sustainable and efficient solvents that are safe for human consumption. This work discusses ethyl lactate as a safe, green, efficient and potentially cheap solvent to recover phytonutrients from fruit and vegetable by-products. Ethyl lactate is compared with other organic solvents commonly used from the aspects of safety, environmental impacts and efficiency. Current challenges when employing ethyl lactate are also discussed.  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