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   700159篇
  免费   49134篇
  国内免费   1186篇
耳鼻咽喉   9151篇
儿科学   23181篇
妇产科学   17577篇
基础医学   109609篇
口腔科学   19919篇
临床医学   62852篇
内科学   132755篇
皮肤病学   16141篇
神经病学   49050篇
特种医学   25665篇
外国民族医学   76篇
外科学   104084篇
综合类   14749篇
一般理论   160篇
预防医学   50858篇
眼科学   16247篇
药学   53704篇
  3篇
中国医学   2291篇
肿瘤学   42407篇
  2019年   5312篇
  2018年   7710篇
  2017年   6031篇
  2016年   6745篇
  2015年   7464篇
  2014年   10227篇
  2013年   15348篇
  2012年   20467篇
  2011年   21481篇
  2010年   12688篇
  2009年   11896篇
  2008年   19961篇
  2007年   21492篇
  2006年   21874篇
  2005年   20409篇
  2004年   19970篇
  2003年   18904篇
  2002年   18414篇
  2001年   36283篇
  2000年   36837篇
  1999年   30219篇
  1998年   7524篇
  1997年   6307篇
  1996年   6577篇
  1995年   6602篇
  1994年   6073篇
  1993年   5568篇
  1992年   22950篇
  1991年   22924篇
  1990年   22298篇
  1989年   22069篇
  1988年   20020篇
  1987年   19412篇
  1986年   18459篇
  1985年   17298篇
  1984年   12683篇
  1983年   10728篇
  1982年   5902篇
  1979年   11499篇
  1978年   8121篇
  1977年   6811篇
  1976年   6570篇
  1975年   7247篇
  1974年   8481篇
  1973年   8119篇
  1972年   7650篇
  1971年   7119篇
  1970年   6871篇
  1969年   6295篇
  1968年   5777篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
AIDS and Behavior - Although misperceived norms often drive personal health behaviors, we do not know about this phenomenon in the context of antiretroviral therapy (ART) adherence. We conducted a...  相似文献   
3.
Spindler  L.  Alam  A.  Fathallah  N.  Rentien  A.-L.  Draullette  M.  Pommaret  E.  Thierry  M.-L.  Mituialy  A. El  Abbes  L.  Aubert  M.  Benfredj  P.  Far  E. Safa  Beaussier  H.  de Parades  V. 《Techniques in coloproctology》2022,26(2):143-146
Techniques in Coloproctology - The aim of our study was to assess the efficacy of sinus laser therapy (SiLaT) for the treatment of pilonidal disease. All adult patients treated with SiLaT in our...  相似文献   
4.
In the last decade, the development of new radiopharmaceuticals for the imaging and therapy of prostate cancer has been a highly active and important area of research, especially focusing on the prostate-specific membrane antigen (PSMA), an antigen which is upregulated in prostate, as well as in other tumor cells. A large variety of PSMA ligands have been radiolabeled, to date. Among the various derivatives, PSMA-617 resulted to be one of the most interesting in terms of interaction with the antigen and clinical properties, and its lutetium-177 labeled version has recently been approved by regulatory agencies for therapeutic purposes. For this reasons, the radiolabeling with fluorine-18 of a PSMA-617 derivative might be of interest. Beside other methodologies to radiolabel macromolecules with fluorine-18, the “click-chemistry” approach resulted to be very useful, and the copper-catalyzed azide-alkyne cycloaddition (CuAAC) is considered one of most efficient and reliable. This paper proposes the synthesis of a suitable precursor for the radiolabeling with fluorine-18 of a new PSMA-617 derivative. The whole radiosynthetic procedure has been fully automated, and the final product, which proved to be stable in plasma, has been obtained with radiochemical yield and purity suitable for subsequent preclinical studies.  相似文献   
5.
6.
7.
8.
Aristodemou  E.  Retzepi  M.  Calciolari  E.  Donos  N. 《Clinical oral investigations》2022,26(8):5223-5235
Clinical Oral Investigations - To evaluate the effect of membrane occlusiveness and experimental diabetes on early and late healing following guided bone regeneration. A total of 30 Wistar rats...  相似文献   
9.
The European Journal of Health Economics - Patient activation comprises the skills, knowledge and motivation necessary for patients’ effective contribution to their care. We adapted and...  相似文献   
10.
Objective

Suicide is the second-leading cause of death in youth. We tested whether having a mentoring relationship associated with lower risks for suicidality, particularly among youth at higher risk due to cyberbullying.

Methods

This study pooled the 2017 Youth Risk Behavior Survey (YRBS) data from five jurisdictions that asked students if there was at least one teacher or other adult in their school that they could talk with, if they have a problem (mentorship). Students self-reported cyberbullying exposure and suicidality in the past 12 months. Odds of suicidal ideation, planning, and attempts were estimated using multivariable weighted logistic regression in overall and sex-stratified stepwise models. Interactions between mentorship and cyberbullying were also tested.

Results

Of the 25,527 student respondents, 87% reported having a mentoring relationship. Mentoring relationships were associated with lower odds of suicidal ideation (aOR, 0.44; 95% CI 0.33–0.57), planning (aOR, 0.59; 95% CI 0.41–0.85), and suicide attempts (aOR, 0.42; 95% CI 0.31–0.56). Stratified analyses showed a significant interaction between cyberbullying and mentorship with suicidal attempts among males, and a near-significant association between cyberbullying and mentorship with suicidal thoughts among females. Compared to male students with no cyberbullying and no mentorship, odds of attempting suicide were lower for males with no cyberbullying and mentorship (aOR, 0.55, 95% CI 0.32–0.92), higher for males with cyberbullying and no mentorship (aOR, 7.78, 95% CI 3.47–17.47), but not significantly different for males with cyberbullying and mentoring relationships (aOR, 1.49, 95% CI 0.86–2.48). Similarly, compared with females with no cyberbullying and no mentorship, odds of having suicidal thoughts were lower for females with no cyberbullying and mentorship (aOR, 0.40, 95% CI 0.28–0.57), and higher for females with cyberbullying and no mentorship (aOR, 2.54, 95% CI 1.59–4.07).

Conclusion

School-based mentoring may mitigate risk of suicidality among adolescents and limit the toxic effects of cyberbullying.

  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