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   30443篇
  免费   2515篇
  国内免费   98篇
耳鼻咽喉   275篇
儿科学   1009篇
妇产科学   659篇
基础医学   4351篇
口腔科学   460篇
临床医学   3718篇
内科学   6200篇
皮肤病学   567篇
神经病学   3157篇
特种医学   562篇
外科学   3118篇
综合类   390篇
一般理论   36篇
预防医学   3429篇
眼科学   404篇
药学   2211篇
中国医学   44篇
肿瘤学   2466篇
  2023年   219篇
  2022年   166篇
  2021年   767篇
  2020年   572篇
  2019年   858篇
  2018年   899篇
  2017年   675篇
  2016年   738篇
  2015年   828篇
  2014年   1053篇
  2013年   1432篇
  2012年   2288篇
  2011年   2311篇
  2010年   1250篇
  2009年   1057篇
  2008年   1806篇
  2007年   1933篇
  2006年   1888篇
  2005年   1765篇
  2004年   1636篇
  2003年   1441篇
  2002年   1315篇
  2001年   377篇
  2000年   357篇
  1999年   334篇
  1998年   236篇
  1997年   162篇
  1996年   167篇
  1995年   187篇
  1994年   145篇
  1993年   141篇
  1992年   256篇
  1991年   266篇
  1990年   267篇
  1989年   265篇
  1988年   257篇
  1987年   229篇
  1986年   218篇
  1985年   169篇
  1984年   174篇
  1983年   136篇
  1982年   106篇
  1981年   115篇
  1980年   96篇
  1979年   130篇
  1978年   113篇
  1977年   95篇
  1976年   98篇
  1974年   132篇
  1973年   118篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Journal of Neuro-Oncology - Craniopharyngiomas are locally-aggressive tumors arising along the hypothalamic-pituitary axis. Treatment is nuanced as a result of their proximity and adherence to...  相似文献   
3.
4.
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Mit Beginn der Impfkampagne hat eine neue Phase der Bewältigung der Coronapandemie begonnen. Zulassung und Empfehlung...  相似文献   
5.
Journal of Neuro-Oncology - MYC-driven medulloblastomas are highly aggressive childhood tumors with dismal outcomes and a lack of new treatment paradigms. We identified that targeting replication...  相似文献   
6.
7.
8.
In some diseases, such as multiple sclerosis, lesion counts obtained from magnetic resonance imaging (MRI) are used as markers of disease progression. This leads to longitudinal, and typically overdispersed, count data outcomes in clinical trials. Models for such data invariably include a number of nuisance parameters, which can be difficult to specify at the planning stage, leading to considerable uncertainty in sample size specification. Consequently, blinded sample size re-estimation procedures are used, allowing for an adjustment of the sample size within an ongoing trial by estimating relevant nuisance parameters at an interim point, without compromising trial integrity. To date, the methods available for re-estimation have required an assumption that the mean count is time-constant within patients. We propose a new modeling approach that maintains the advantages of established procedures but allows for general underlying and treatment-specific time trends in the mean response. A simulation study is conducted to assess the effectiveness of blinded sample size re-estimation methods over fixed designs. Sample sizes attained through blinded sample size re-estimation procedures are shown to maintain the desired study power without inflating the Type I error rate and the procedure is demonstrated on MRI data from a recent study in multiple sclerosis.  相似文献   
9.
Aim: Clerkship-specific interactive reflective writing (IRW)-enhanced reflection may enhance professional identity formation (PIF), a fundamental goal of medical education. PIF process as revealed in students? reflective writing (RW) has been understudied.

Methods: The authors developed an IRW curriculum within a Family Medicine Clerkship (FMC) and analyzed students? reflections about challenging/difficult patient encounters using immersion-crystallization qualitative analysis.

Results: The qualitative analysis identified 26 unique emergent themes and five distinct thematic categories (1. Role of emotions, 2. Role of cognition, 3. Behaviorally responding to situational context, 4. Patient factors, and 5. External factors) as well as an emergent PIF model from a directed content analysis. The model describes students? backgrounds, emotions and previous experiences in medicine merging with external factors and processed during student?patient interactions. The RWs also revealed that processing often involves polarities (e.g. empathy/lack of empathy or encouragement/disillusionment) as well as dissonance between idealized visions and lived reality.

Conclusions: IRW facilitates and ideally supports grappling with the lived reality of medicine; uncovering a “positive hidden curriculum” within medical education. The authors propose engaging learners in guided critical reflection about complex experiences for meaning-making within a safe learning climate as a valuable way to cultivate reflective, resilient professionals with “prepared” minds and hearts for inevitable challenges of healthcare practice.  相似文献   
10.

Objective

Successful weight loss interventions for African-Americans adolescents are lacking. Cognitive-behavioral interventions seek to develop weight loss skills (e.g., counting calories, goal setting, managing one's environment). Little is known about how well adolescents implement such skills in their daily lives. Study aims were to (1) examine weight loss skills utilization at midpoint and end of a 6-month cognitive-behavioral/motivational interviewing weight loss sequential multiple assignment randomized trial (SMART), and (2) determine if greater skill utilization predicted weight loss at treatment end and 3 months post-treatment.

Method

One hundred and eighty six African-Americans adolescents with obesity and their caregiver were first randomly assigned to complete 3 months of cognitive-behavioral and motivational interviewing family-based weight loss treatment in their home or in the research office (Phase 1). Nonresponders (i.e., those who lost < 3% of initial weight, n?=?161) were rerandomized to 3 months of continued skills training (n?=?83) or contingency management (n?=?78) for Phase 2; responders were allocated to 3 months of relapse prevention (n?=?20). Adolescents’ frequency of weight loss skills utilization was assessed via questionnaire at treatment midpoint and end.

Results

Higher treatment attendance was associated with better skill utilization. Higher skill utilization was associated with more weight loss at treatment end, whereas higher baseline confidence was associated with more weight loss at follow-up.

Conclusions

This study indicates the importance of attending weight loss intervention sessions to develop and strengthen weight loss skills in African-American adolescents with obesity, and strengthening confidence to use such skills for continued weight loss.  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