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   4125672篇
  免费   330988篇
  国内免费   14653篇
耳鼻咽喉   57650篇
儿科学   131135篇
妇产科学   109047篇
基础医学   634703篇
口腔科学   113857篇
临床医学   370023篇
内科学   740605篇
皮肤病学   104766篇
神经病学   342131篇
特种医学   164069篇
外国民族医学   593篇
外科学   638278篇
综合类   118672篇
现状与发展   23篇
一般理论   2386篇
预防医学   335628篇
眼科学   96196篇
药学   295496篇
  26篇
中国医学   11694篇
肿瘤学   204335篇
  2021年   55928篇
  2020年   35628篇
  2019年   58704篇
  2018年   73433篇
  2017年   55698篇
  2016年   61746篇
  2015年   75364篇
  2014年   109897篇
  2013年   175544篇
  2012年   110088篇
  2011年   113441篇
  2010年   122652篇
  2009年   125286篇
  2008年   100665篇
  2007年   107007篇
  2006年   116500篇
  2005年   111671篇
  2004年   112743篇
  2003年   103549篇
  2002年   93416篇
  2001年   149350篇
  2000年   143773篇
  1999年   134646篇
  1998年   69991篇
  1997年   66294篇
  1996年   64277篇
  1995年   59696篇
  1994年   53708篇
  1993年   49862篇
  1992年   97597篇
  1991年   93757篇
  1990年   90785篇
  1989年   88858篇
  1988年   82227篇
  1987年   80138篇
  1986年   76283篇
  1985年   74780篇
  1984年   63155篇
  1983年   56745篇
  1982年   46542篇
  1981年   43328篇
  1980年   40820篇
  1979年   54330篇
  1978年   44088篇
  1977年   40139篇
  1976年   36628篇
  1975年   37075篇
  1974年   39806篇
  1973年   38366篇
  1972年   36196篇
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
941.
942.
943.
944.
李焱  翟凤霞 《陕西中医》2020,(5):660-662
妊娠期间,咳嗽不已,称"妊娠咳嗽",亦称"子嗽",孕妇咳嗽日久未见好转,咳嗽胸痛甚则咳而呕吐,或咳嗽剧烈或久咳不愈,可损伤胎气,导致堕胎、小产。笔者运用六经辨证治疗外感型中表寒里热证子嗽,认为此类患者病在太阳阳明,属于寒热错杂之表寒里热,采用《伤寒论》中方证麻杏甘石汤合止嗽散,使热从外泄,宣发卫气,散寒不助热、解表不伤正,故辨证论治取得了显著的疗效。同时子嗽治疗还需注意健脾固肾安胎,应将顾护胎元贯穿治疗妊娠咳嗽的始终。  相似文献   
945.
946.
947.
Understanding the contribution of endothelial cells to the progenitor pools of adult tissues has the potential to inform therapies for human disease.To address whether endothelial cells transdifferentiate into non-vascular cell types,we performed cell lineage tracing analysis using transgenic mice engineered to express a fluorescent marker following activation by tamoxifen in vascular endothelial cadherin promoter-expressing cells(VEcad-CreERT2;B6 Cg-Gt(ROSA)26Sortm9(CAG-tdTomato)Hze).Activation of target-cell labeling following 1.5 months of ad libitum feeding with tamoxifen-laden chow in 4–5 month-old mice resulted in the tracing of central nervous system and peripheral cells that include:cerebellar granule neurons,ependymal cells,skeletal myocytes,pancreatic beta cells,pancreatic acinar cells,tubular cells in the renal cortex,duodenal crypt cells,ileal crypt cells,and hair follicle stem cells.As Nestin expression has been reported in a subset of endothelial cells,Nes-CreERT2 mice were also utilized in these conditions.The tracing of cells in adult Nes-CreERT2 mice revealed the labeling of canonical progeny cell types such as hippocampal and olfactory granule neurons as well as ependymal cells.Interestingly,Nestin tracing also labeled skeletal myocytes,ileal crypt cells,and sparsely marked cerebellar granule neurons.Our findings provide support for endothelial cells as active contributors to adult tissue progenitor pools.This information could be of particular significance for the intravenous delivery of therapeutics to downstream endothelial-derived cellular targets.The animal experiments were approved by the Boise State University Institute Animal Care and Use Committee(approval No.006-AC15-018)on October 31,2018.  相似文献   
948.
ABSTRACT

Abortion is legal in South Africa, but negative abortion attitudes remain common and are poorly understood. We used nationally representative South African Social Attitudes Survey data to analyze abortion attitudes in the case of fetal anomaly and in the case of poverty from 2007 to 2016 (n = 20,711; ages = 16+). We measured correlations between abortion attitudes and these important predictors: religiosity, attitudes about premarital sex, attitudes about preferential hiring and promotion of women, and attitudes toward family gender roles. Abortion acceptability for poverty increased over time (b = 0.05, p < .001), but not for fetal anomaly (b = ?0.008, p = .284). Highly religious South Africans reported lower abortion acceptability in both cases (Odds Ratio (OR)anomaly = 0.85, p = .015; ORpoverty = 0.84, p = .02). Premarital sex acceptability strongly and positively predicted abortion acceptability (ORanomaly = 2.63, p < .001; ORpoverty = 2.46, p < .001). Attitudes about preferential hiring and promotion of women were not associated with abortion attitudes, but favorable attitudes about working mothers were positively associated with abortion acceptability for fetal anomaly ((ORanomaly = 1.09, p = .01; ORpoverty = 1.02, p = .641)). Results suggest negative abortion attitudes remain common in South Africa and are closely tied to religiosity, traditional ideologies about sexuality, and gender role expectations about motherhood.  相似文献   
949.
ABSTRACT

Objectives: The present study investigated the relationships of enculturation and depressive symptoms with health risk behavior engagement in Mexican-American college students and examined how these relationships differed by gender. Previous research has noted consistent gender differences in health risk behavior (e.g. alcohol use, substance use, and risky sexual behavior) among Latina/os, and emphasized the role of U.S. acculturation in this difference. Research examining the role of heritage cultural retention (i.e. enculturation), and including the added influence of mental health variables, such as depressive symptoms, is currently lacking. This study sought to address this gap.

Design: A large sample (N?=?677) of Mexican-American college students from four universities (located in New York, California, Florida, and Texas) completed an online questionnaire assessing health risk behaviors and corresponding variables.

Results: We found that males who endorsed more behavioral enculturation and depressive symptoms were more likely to engage in health risk behavior than all others in the sample. Contrary to previous literature, no relationship was found between behavioral enculturation and health risk behavior in females.

Conclusion: The current study found behavioral enculturation to be associated with depressive symptoms, and in turn with health risk behaviors among the males in our sample. Additional research will be needed to identify the mechanism underlying the relationship between enculturation and depressive symptoms as well as between depressive symptoms and risky behavior.  相似文献   
950.
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