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   2876篇
  免费   227篇
  国内免费   7篇
耳鼻咽喉   37篇
儿科学   82篇
妇产科学   68篇
基础医学   415篇
口腔科学   54篇
临床医学   288篇
内科学   540篇
皮肤病学   73篇
神经病学   338篇
特种医学   47篇
外科学   335篇
综合类   19篇
预防医学   378篇
眼科学   60篇
药学   182篇
中国医学   15篇
肿瘤学   179篇
  2024年   6篇
  2023年   63篇
  2022年   98篇
  2021年   227篇
  2020年   140篇
  2019年   146篇
  2018年   175篇
  2017年   102篇
  2016年   105篇
  2015年   94篇
  2014年   134篇
  2013年   158篇
  2012年   230篇
  2011年   241篇
  2010年   136篇
  2009年   105篇
  2008年   148篇
  2007年   144篇
  2006年   131篇
  2005年   123篇
  2004年   115篇
  2003年   80篇
  2002年   62篇
  2001年   11篇
  2000年   15篇
  1999年   10篇
  1998年   10篇
  1997年   11篇
  1996年   11篇
  1995年   13篇
  1994年   2篇
  1993年   10篇
  1992年   3篇
  1991年   5篇
  1990年   10篇
  1989年   7篇
  1988年   4篇
  1987年   8篇
  1985年   2篇
  1984年   2篇
  1983年   1篇
  1982年   3篇
  1981年   3篇
  1980年   2篇
  1975年   2篇
  1937年   1篇
  1928年   1篇
排序方式: 共有3110条查询结果,搜索用时 295 毫秒
91.
92.
Journal of Autism and Developmental Disorders - Cognitive reappraisal is associated with reduced emotional distress; however, little is known about the nature of this relationship in autism. This...  相似文献   
93.
94.

Purpose

Decreased vitamin D levels have been associated with prostate cancer, but it is unclear whether this association is causal. A functional single-nucleotide polymorphism (SNP) in the group-specific component (GC) gene (T > G, rs2282679) has been associated with 25-hydroxy (25-OH) vitamin D and 1.25 dihydroxy (1.25-OH2) vitamin D levels.

Methods

To examine the hypothesized inverse relationship between vitamin D status and prostate cancer, we studied the association between this SNP and prostate cancer outcome in the prospective PROCAGENE study comprising 702 prostate cancer patients with a median follow-up of 82 months.

Results

GC rs2282679 genotypes were not associated with biochemical recurrence [hazard ratios (HR) 0.91, 95 % confidence interval (CI) 0.73–1.12; p = 0.36], development of metastases (HR 1.20, 95 % CI 0.88–1.63; p = 0.25) or overall survival (HR 1.10; 95 % CI 0.84–1.43; p = 0.50).

Conclusions

A causal role of vitamin D status, as reflected by GC rs2282679 genotype, in disease progression and mortality in prostate cancer patients is unlikely.
  相似文献   
95.
Prenatal forms of autosomal dominant polycystic kidney disease (ADPKD) are rare but can be recurrent in some families, suggesting a common genetic modifying background. Few patients have been reported carrying, in addition to the familial mutation, variation(s) in polycystic kidney disease 1 (PKD1) or HNF1 homeobox B (HNF1B), inherited from the unaffected parent, or biallelic polycystic kidney and hepatic disease 1 (PKHD1) mutations. To assess the frequency of additional variations in PKD1, PKD2, HNF1B, and PKHD1 associated with the familial PKD mutation in early ADPKD, these four genes were screened in 42 patients with early ADPKD in 41 families. Two patients were associated with de novo PKD1 mutations. Forty patients occurred in 39 families with known ADPKD and were associated with PKD1 mutation in 36 families and with PKD2 mutation in two families (no mutation identified in one family). Additional PKD variation(s) (inherited from the unaffected parent when tested) were identified in 15 of 42 patients (37.2%), whereas these variations were observed in 25 of 174 (14.4%, P=0.001) patients with adult ADPKD. No HNF1B variations or PKHD1 biallelic mutations were identified. These results suggest that, at least in some patients, the severity of the cystic disease is inversely correlated with the level of polycystin 1 function.  相似文献   
96.
97.

Background

We examined whether enhancing self-affirmation among a population of drinkers, prior to viewing threatening alcohol pictorial health warning labels, would reduce defensive reactions and promote reactions related to behaviour change. We also examined how health warning severity influences these reactions and whether there is an interaction between self-affirmation and severity.

Methods

In this experimental human laboratory study, participants (n =?128) were randomised to a self-affirmation or control group. After the self-affirmation manipulation was administered, we tracked participants’ eye movements while they viewed images of six moderately-severe and six highly-severe pictorial health warning labels presented on large beer cans. Self-reported responses to the pictorial health warning labels were then measured, including avoidance, reactance, effectiveness, susceptibility and motivation to drink less. Finally, participants reported their self-efficacy to drink less and their alcohol use.

Results

There was no clear evidence that enhancing self-affirmation influenced any outcome. In comparison to moderately-severe health warnings, highly-severe health warnings increased avoidance and reactance and were perceived as more effective and increased motivation to drink less.

Conclusions

These findings call into question the validity of the self-affirmation manipulation, which is purported to reduce defensive reactions to threatening warnings. We discuss possible explanations for this null effect, including the impact of participants’ low perceived susceptibility to the risks shown on these pictorial health warning labels. Our finding that highly-severe health warnings increase avoidance and reactance but are also perceived as being more effective and more likely to motivate people to drink less will inform future health warning design and have implications for health warning label theory.
  相似文献   
98.

Aim

Nutritional screening may not always lead to intervention. The present study aimed to determine: (i) the rate of nutritional screening in hospitalised older adults; (ii) whether nutritional screening led to dietitian consultation and (iii) factors associated with malnutrition.

Methods

In this prospective study of patients aged ≥70 years admitted to a Geriatric Evaluation and Management Unit (GEMU), malnutrition was screened for using the Mini Nutritional Assessment Short Form (MNA‐SF) and identified using the Mini Nutritional Assessment (MNA).

Results

Of the 172 patients participating in the study, 53 (30.8%) patients were malnourished, and 84 (48.8%) were at risk of malnutrition. Mean (SD) age was 85.2 (6.4 years), with 131 patients (76.2%) female. Nutritional screening was performed for all patients; however, it was incomplete in 59 (34.3%) because of omission of the anthropometric measurement. Overall, 62 (36.0%) of the total number of patients were seen by the dietitian, which included 26 (49%) of malnourished patients, 27 (32%) of at‐risk patients and 9 (26%) of the well‐nourished patients. No patients lost >1% of body weight during GEMU stay. Malnourished patients were more likely to be frail, have poor appetite, depression, and have lower levels of: albumin, cognition, physical function, grip strength and quality of life.

Conclusions

The full benefits of nutritional screening by MNA‐SF may not be realised if it does not result in malnourished patients receiving a dietitian consultation. However, it is possible that enrichment of the foodservice with high protein/high‐energy options minimised patient weight loss in the GEMU.  相似文献   
99.
100.
Introduction: A seasonal affective disorder (SAD) is a subtype of unipolar and bipolar major depressive disorders. It is characterized by its annual recurrence of depressive episodes at a particular season, mostly seen in winter and is responsible for 10–20% of the prevalence of major depressive disorders. Some pathophysiological hypotheses, such as the phase delay and the monoamine depletion hypotheses, have been postulated but the exact cause has not been fully unraveled yet. Studies on treatment for SAD in the last decade are lacking. To tackle this chronic disease, attention needs to be drawn to the gaps in this research field.

Areas covered: In this systematic review, the authors give a broad overview of the pharmacological therapy available for SAD. Also, nutritional substances fitting well with the postulated hypotheses are reviewed for the treatment and prevention of SAD. There is a specific focus on the quality of the currently performed studies.

Expert opinion: Light therapy and fluoxetine are the only proven and effective acute treatment options for SAD, while bupropion is the only registered drug for prevention of SAD. This area of research is in dire need of valid large-scale and sufficiently reproducible randomized control trials.  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