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   8427篇
  免费   638篇
  国内免费   31篇
耳鼻咽喉   111篇
儿科学   194篇
妇产科学   224篇
基础医学   1313篇
口腔科学   142篇
临床医学   761篇
内科学   1901篇
皮肤病学   136篇
神经病学   787篇
特种医学   261篇
外科学   1193篇
综合类   111篇
现状与发展   1篇
一般理论   14篇
预防医学   699篇
眼科学   221篇
药学   472篇
中国医学   8篇
肿瘤学   547篇
  2023年   95篇
  2022年   179篇
  2021年   292篇
  2020年   170篇
  2019年   293篇
  2018年   303篇
  2017年   186篇
  2016年   200篇
  2015年   248篇
  2014年   302篇
  2013年   426篇
  2012年   549篇
  2011年   608篇
  2010年   281篇
  2009年   307篇
  2008年   456篇
  2007年   518篇
  2006年   435篇
  2005年   458篇
  2004年   475篇
  2003年   423篇
  2002年   410篇
  2001年   78篇
  2000年   59篇
  1999年   71篇
  1998年   79篇
  1997年   70篇
  1996年   59篇
  1995年   60篇
  1994年   55篇
  1993年   53篇
  1992年   40篇
  1991年   36篇
  1990年   36篇
  1989年   47篇
  1988年   42篇
  1987年   48篇
  1986年   30篇
  1985年   31篇
  1984年   38篇
  1983年   34篇
  1982年   33篇
  1981年   32篇
  1980年   25篇
  1978年   27篇
  1977年   25篇
  1976年   29篇
  1974年   26篇
  1973年   31篇
  1972年   24篇
排序方式: 共有9096条查询结果,搜索用时 15 毫秒
101.
Objective Our aim was to cross-culturally validate Chinese Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) in patients with knee osteoarthritis (OA) scheduled for total knee replacement in Singapore. Methods Chinese WOMAC was translated from the original English version following standard guidelines. Patients were asked to complete a questionnaire containing the WOMAC (twice within 6 days), the Short Form 36 (SF-36), and the EuroQoL EQ-5D. Reliability was assessed using Cronbach’s alpha and intraclass correlation coefficients (ICC), dimensionality using item-to-domain correlations and factor analyses. Convergent and discriminant construct validity was assessed using six each a priori hypotheses. Results Chinese WOMAC was well accepted by the patients in the pilot test. The Chinese and English versions were therefore administered to a consecutive sample of 131 Chinese- and 127 English-speaking subjects, respectively, with knee OA. Cronbach’s alpha exceeded 0.7 for all domains except for Chinese pain domain, whereas the ICC exceeded 0.7 for all domains. Hypothesized item-to-domain correlations were observed for all items except for four items in Chinese physical function domain. The factor analyses yielded seven and five factors with eigenvalues of more than 1.0 in the Chinese and English versions, respectively. A total of 10/12 a priori construct validity hypotheses were satisfied for the Chinese version. Weak correlations between WOMAC pain and SF-36 bodily pain and moderate correlation between WOMAC pain and EQ-5D anxiety/depression were observed. Conclusions Chinese WOMAC was well accepted and demonstrated acceptable psychometric properties in Singaporean patients with severe knee OA.  相似文献   
102.
Introduction:HIV confers increased risk of myocardial infarction (MI), but there has been little study of ischemic electrocardiogram (ECG) findings among people with HIV in sub-Saharan Africa.Objectives:To compare the prevalence of ischemic ECG findings among Tanzanians with and without HIV and to identify correlates of ischemic ECG changes among Tanzanians with HIV.Methods:Consecutive adults presenting for routine HIV care at a Tanzanian clinic were enrolled. Age- and sex-matched HIV-uninfected controls were enrolled from a nearby general clinic. All participants completed a standardized health questionnaire and underwent 12-lead resting ECG testing, which was adjudicated by independent physicians. Prior MI was defined as pathologic Q-waves in contiguous leads, and myocardial ischemia was defined as ST-segment depression or T-wave inversion in contiguous leads. Pearson’s chi-squared test was used to compare the prevalence of ECG findings among those with and without HIV and multivariate logistic regression was performed to identify correlates of prior MI among all participants.Results:Of 497 participants with HIV and 497 without HIV, 272 (27.8%) were males and mean (sd) age was 45.2(12.0) years. ECG findings suggestive of prior MI (11.1% vs 2.4%, OR 4.97, 95% CI: 2.71–9.89, p < 0.001), and myocardial ischemia (18.7% vs 12.1% OR 1.67, 95% CI: 1.18–2.39, p = 0.004) were significantly more common among participants with HIV. On multivariate analysis, ECG findings suggestive of prior MI among all participants were associated with HIV infection (OR 4.73, 95% CI: 2.51–9.63, p = 0.030) and self-reported family history of MI or stroke (OR 1.96, 95% CI: 1.08–3.46, p = 0.023).Conclusions:There may be a large burden of ischemic heart disease among adults with HIV in Tanzania, and ECG findings suggestive of coronary artery disease are significantly more common among Tanzanians with HIV than those without HIV.  相似文献   
103.
104.
105.
Two decades of studies suggest that computerized cognitive training (CCT) has an effect on cognitive improvement and the restoration of brain activity. Nevertheless, individual response to CCT remains heterogenous, and the predictive potential of neuroimaging in gauging response to CCT remains unknown. We employed multivariate pattern analysis (MVPA) on whole-brain resting-state functional connectivity (rsFC) to (neuro)monitor clinical outcome defined as psychosis-likeness change after 10-hours of CCT in recent onset psychosis (ROP) patients. Additionally, we investigated if sensory processing (SP) change during CCT is associated with individual psychosis-likeness change and cognitive gains after CCT. 26 ROP patients were divided into maintainers and improvers based on their SP change during CCT. A support vector machine (SVM) classifier separating 56 healthy controls (HC) from 35 ROP patients using rsFC (balanced accuracy of 65.5%, P < 0.01) was built in an independent sample to create a naturalistic model representing the HC-ROP hyperplane. This model was out-of-sample cross-validated in the ROP patients from the CCT trial to assess associations between rsFC pattern change, cognitive gains and SP during CCT. Patients with intact SP threshold at baseline showed improved attention despite psychosis status on the SVM hyperplane at follow-up (p < 0.05). Contrarily, the attentional gains occurred in the ROP patients who showed impaired SP at baseline only if rsfMRI diagnosis status shifted to the healthy-like side of the SVM continuum. Our results reveal the utility of MVPA for elucidating treatment response neuromarkers based on rsFC-SP change and pave the road to more personalized interventions.Subject terms: Predictive markers, Psychosis  相似文献   
106.
locStra is an ‐package for the analysis of regional and global population stratification in whole‐genome sequencing (WGS) studies, where regional stratification refers to the substructure defined by the loci in a particular region on the genome. Population substructure can be assessed based on the genetic covariance matrix, the genomic relationship matrix, and the unweighted/weighted genetic Jaccard similarity matrix. Using a sliding window approach, the regional similarity matrices are compared with the global ones, based on user‐defined window sizes and metrics, for example, the correlation between regional and global eigenvectors. An algorithm for the specification of the window size is provided. As the implementation fully exploits sparse matrix algebra and is written in C++, the analysis is highly efficient. Even on single cores, for realistic study sizes (several thousand subjects, several million rare variants per subject), the runtime for the genome‐wide computation of all regional similarity matrices does typically not exceed one hour, enabling an unprecedented investigation of regional stratification across the entire genome. The package is applied to three WGS studies, illustrating the varying patterns of regional substructure across the genome and its beneficial effects on association testing.  相似文献   
107.
108.

Background

The Veterans Health Administration (VHA) faces challenges in providing comprehensive, gender-sensitive care for women. National policies have led to important advancements, but local leadership also plays a vital role in implementing changes and operationalizing national priorities. In this article, we explore the notions of ideal women veterans' health care articulated by women's health leaders at local VHA facilities and regional networks, with the goal of identifying elements that could inform practice and policy.

Methods

We conducted semistructured interviews with 86 local and regional women's health leaders at 12 VHA medical centers across four regions. At the conclusion of interviews about women's primary care, participants were asked to imagine “ideal care” for women veterans. Interviews were transcribed and coded using a hybrid inductive/deductive approach.

Results

In describing ideal care, participants commonly touched on whether women veterans should have separate primary care services from men; the need for childcare, expanded reproductive health services, resources, and staffing; geographic accessibility; the value of input from women veterans; the physical appearance of facilities; fostering active interest in women's health across providers and staff; and the relative priority of women's health at the VHA.

Conclusions

Policy and practice changes to care for women veterans must be mindful of key stakeholders' vision for that care. Specific features of that vision include clinic construction that anticipates a growing patient population, providing childcare and expanded reproductive health services, ensuring adequate support staff, expanding mechanisms to incorporate women veterans' input, and fostering a culture oriented towards women's health at the organizational level.  相似文献   
109.
This study was conducted to investigate the effect of Plasmodium falciparum and intestinal helminth coinfection on maternal anemia and birth outcomes. A cross-sectional study of 746 women who delivered in two hospitals in Kumasi was conducted. Data were collected using an investigator-administered questionnaire and from patients'' medical records. Blood was collected for determination of P. falciparum and hemoglobin levels. Adverse pregnancy outcomes were high (44.6%). Coinfection (versus no infection) was associated with 3-fold increase in low birth weight. For women with anemia, coinfection was 2.6 times and 3.5 times as likely to result in preterm deliveries and small for gestational age infants. The odds of having anemia was increased almost 3-fold by coinfection. Coinfection (versus helminth only) resulted in increased risks of anemia, low birth weight, and small for gestational age infants. This study demonstrates that women with malaria and intestinal helminth coinfection are at particular risk of adverse birth outcomes.  相似文献   
110.
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