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   551778篇
  免费   29834篇
  国内免费   578篇
耳鼻咽喉   6841篇
儿科学   17603篇
妇产科学   13014篇
基础医学   95223篇
口腔科学   13269篇
临床医学   50607篇
内科学   99548篇
皮肤病学   12145篇
神经病学   36278篇
特种医学   20727篇
外国民族医学   55篇
外科学   81715篇
综合类   7878篇
现状与发展   3篇
一般理论   141篇
预防医学   40438篇
眼科学   12466篇
药学   43042篇
  1篇
中国医学   1152篇
肿瘤学   30044篇
  2021年   4599篇
  2019年   4422篇
  2018年   6358篇
  2017年   4602篇
  2016年   5344篇
  2015年   5923篇
  2014年   7899篇
  2013年   11494篇
  2012年   17098篇
  2011年   18934篇
  2010年   10803篇
  2009年   9625篇
  2008年   17016篇
  2007年   18745篇
  2006年   18200篇
  2005年   17533篇
  2004年   17019篇
  2003年   16242篇
  2002年   15702篇
  2001年   22783篇
  2000年   23274篇
  1999年   19204篇
  1998年   5437篇
  1997年   4532篇
  1996年   4566篇
  1995年   4270篇
  1992年   14650篇
  1991年   16038篇
  1990年   16179篇
  1989年   15867篇
  1988年   14509篇
  1987年   14424篇
  1986年   13351篇
  1985年   12857篇
  1984年   9572篇
  1983年   8126篇
  1982年   4273篇
  1979年   9060篇
  1978年   6497篇
  1977年   5246篇
  1976年   5615篇
  1975年   6709篇
  1974年   7518篇
  1973年   7273篇
  1972年   6693篇
  1971年   6388篇
  1970年   5951篇
  1969年   5528篇
  1968年   5226篇
  1967年   4676篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
Journal of Behavioral Medicine - Evidence supports the use of graphic warnings to educate the public about the health harms of smoking and suggests warnings eliciting negative emotional responses...  相似文献   
2.
The adrenal cortex gives rise to a biologically heterogenous group of neoplasms, each with a distinct morphology, antigen expression and molecular profile. Adrenal cortical adenomas have excellent prognosis and are usually cured by surgical resection alone, while adrenal cortical carcinomas are very aggressive tumors with a poor prognosis regardless of therapy. These tumors are rare and often challenging for a pathologist to diagnose, as significant overlap exists between benign and malignant lesions in some cases. In this review, we attempt to summarize most important histologic and clinical features of adrenal cortical adenomas and carcinomas, clarify the use of different grading systems, the use of special stains and the differential diagnosis for practicing pathologists. Most relevant hereditary syndromes associated with adrenal cortical tumors are listed. Updates in molecular alterations in adrenal cortical neoplasms and hyperplastic diseases as well as their clinical significance and potential therapeutic implications are also discussed.  相似文献   
3.
4.
5.
6.
Journal of Immigrant and Minority Health - COVID-19 has disproportionally affected underrepresented minorities (URM) and low-income immigrants in the United States. The aim of the study is to...  相似文献   
7.
8.
The purpose of this investigation was to characterize noise levels in spaces designated as “effective quiet” areas on a U.S. Navy aircraft carrier. Noise dosimetry samples were collected in 15 designated spaces, representing 15 noise measurements, while at-sea during airwing carrier qualifications. Equivalent sound level (Leq) measurements were collected during flight operations (Leq (flt ops)), non-flight operations (Leq (non-flt ops)), and over 24-hr periods (Leq (24-hr)). These data were compared to the 70 dBA American Conference of Governmental Industrial Hygienists (ACGIH®) Threshold Limit Value (TLV®) for “effective quiet” areas intended for temporary threshold shift recovery when personnel live and work in a potentially noise hazardous environment for periods greater than 24?hr. The monitored areas were selected based on personnel occupancy/use during off-duty time periods. Areas were classified by either (1) leisure areas that included mess (eating areas), gyms, lounges, an internet cafe, and the fantail social area or (2) berthing (sleeping) areas. The Leq measurements in decibels “A” weighted (dBA) were compared to determine significant differences between Leq (flt ops), Leq (non-flt ops), and Leq (24-hr) and were compared between leisure area and berthing area. Measured noise levels according to time period ranged as follows: (1) Leq (24-hr): 70.8–105.4 dBA; (2) Leq (flt ops): 70–101.2 dBA; and (3) Leq (non-flt ops): 39.4–104.6 dBA. All area measurements over the 24-hr period and during flight operations and 46.7% of the areas during the non-flight operation time period exceeded the “effective quiet” 70 dBA ACGIH TLV. Mean Leqs were 15 dBA higher during flight operations compared to non-flight operations in “effective quiet” areas (p?=?0.001). The Leqs in leisure areas were significantly higher than berthing areas by approximately 21 dBA during non-flight operation periods (p?=?0.001). Results suggest noise levels in “effective quiet” areas frequented by aircraft carrier personnel during off-duty hours when at-sea may inhibit auditory recovery from occupational noise exposures that occur on-duty.  相似文献   
9.
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was...  相似文献   
10.
Bulletin of Experimental Biology and Medicine - Ammonium, an end-product of catabolism, in low doses can promote adaptation of metabolic pathways in erythrocytes under conditions of extreme...  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