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   528316篇
  免费   28261篇
  国内免费   483篇
耳鼻咽喉   6684篇
儿科学   16928篇
妇产科学   12562篇
基础医学   92493篇
口腔科学   12354篇
临床医学   48243篇
内科学   94929篇
皮肤病学   11879篇
神经病学   33929篇
特种医学   19759篇
外国民族医学   53篇
外科学   78115篇
综合类   7629篇
现状与发展   2篇
一般理论   107篇
预防医学   38446篇
眼科学   11890篇
药学   41389篇
  1篇
中国医学   1108篇
肿瘤学   28560篇
  2019年   3907篇
  2018年   5747篇
  2017年   4138篇
  2016年   4879篇
  2015年   5378篇
  2014年   7132篇
  2013年   10531篇
  2012年   15605篇
  2011年   17433篇
  2010年   9987篇
  2009年   8846篇
  2008年   15737篇
  2007年   17478篇
  2006年   16976篇
  2005年   16292篇
  2004年   15906篇
  2003年   15283篇
  2002年   14793篇
  2001年   22447篇
  2000年   22997篇
  1999年   18943篇
  1998年   5241篇
  1997年   4352篇
  1996年   4125篇
  1995年   4111篇
  1992年   14424篇
  1991年   15844篇
  1990年   15967篇
  1989年   15643篇
  1988年   14320篇
  1987年   14198篇
  1986年   13181篇
  1985年   12688篇
  1984年   9393篇
  1983年   8000篇
  1982年   4167篇
  1979年   8932篇
  1978年   6378篇
  1977年   5135篇
  1976年   5511篇
  1975年   6608篇
  1974年   7421篇
  1973年   7161篇
  1972年   6594篇
  1971年   6312篇
  1970年   5885篇
  1969年   5462篇
  1968年   5159篇
  1967年   4618篇
  1966年   3967篇
排序方式: 共有10000条查询结果,搜索用时 593 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.
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   
6.
Microbial co-infections are another primary concern in patients with coronavirus disease 2019 (COVID-19), yet it is an untouched area among researchers. Preliminary data and systematic reviews only show the type of pathogens responsible for that, but its pathophysiology is still unknown. Studies show that these microbial co-infections are hospital-acquired/nosocomial infections, and patients admitted to intensive care units with invasive mechanical ventilation are highly susceptible to it. Patients with COVID-19 had elevated inflammatory cytokines and a weakened cell-mediated immune response, with lower CD4+ T and CD8+ T cell counts, indicating vulnerability to various co-infections. Despite this, there are only a few studies that recommend the management of co-infections.  相似文献   
7.
8.
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   
9.
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   
10.
There is evidence that caesarean section delivery can impact on neonatal weight loss and weight gain patterns in the first 5 days of life. We conducted an integrative systematic review to examine the association of mode of delivery on early neonatal weight loss. Pubmed, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Excerpta Medica dataBASE, and Medical Literature Analysis and Retrieval System Online were searched for relevant papers published before June 2019. Reference lists from the relevant papers were then backwards and forwards searched. As neonatal weight loss was reported in different formats, a meta‐analysis could not be carried out. Most studies did not distinguish between elective and emergency caesarean sections or instrumental and nonassisted vaginal deliveries. Seven papers were included. All papers except one found that caesarean section was associated with higher weight loss in the early days of life. Two papers presented data from studies on babies followed up to 1 month. One study found that on day 25, babies born by caesarean section had significantly higher weight gain than those born vaginally, while another found that by day 28, babies born vaginally gained more weight per day (11.9 g/kg/day) than those born by caesarean section (10.9 g/kg/day; p = .02). Overall, infants born by caesarean section lost more weight than those born vaginally, but due to the small number of studies included, more are needed to look at this difference and why it may occur. This discrepancy in weight between the two groups may be corrected over time, but future studies will need larger sample sizes and longer follow‐up periods to examine this.  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