全文获取类型
收费全文 | 74191篇 |
免费 | 6665篇 |
国内免费 | 158篇 |
专业分类
耳鼻咽喉 | 675篇 |
儿科学 | 2720篇 |
妇产科学 | 2466篇 |
基础医学 | 8918篇 |
口腔科学 | 882篇 |
临床医学 | 11378篇 |
内科学 | 13604篇 |
皮肤病学 | 1169篇 |
神经病学 | 7175篇 |
特种医学 | 1727篇 |
外科学 | 8341篇 |
综合类 | 787篇 |
现状与发展 | 1篇 |
一般理论 | 98篇 |
预防医学 | 9556篇 |
眼科学 | 1295篇 |
药学 | 4906篇 |
中国医学 | 86篇 |
肿瘤学 | 5230篇 |
出版年
2023年 | 757篇 |
2022年 | 961篇 |
2021年 | 2180篇 |
2020年 | 1403篇 |
2019年 | 2190篇 |
2018年 | 2439篇 |
2017年 | 1918篇 |
2016年 | 2117篇 |
2015年 | 2169篇 |
2014年 | 3102篇 |
2013年 | 4146篇 |
2012年 | 5719篇 |
2011年 | 5743篇 |
2010年 | 3243篇 |
2009年 | 2896篇 |
2008年 | 4700篇 |
2007年 | 4697篇 |
2006年 | 4369篇 |
2005年 | 4128篇 |
2004年 | 3715篇 |
2003年 | 3253篇 |
2002年 | 2962篇 |
2001年 | 774篇 |
2000年 | 675篇 |
1999年 | 756篇 |
1998年 | 672篇 |
1997年 | 546篇 |
1996年 | 517篇 |
1995年 | 488篇 |
1994年 | 408篇 |
1993年 | 365篇 |
1992年 | 484篇 |
1991年 | 406篇 |
1990年 | 437篇 |
1989年 | 420篇 |
1988年 | 336篇 |
1987年 | 332篇 |
1986年 | 352篇 |
1985年 | 335篇 |
1984年 | 307篇 |
1983年 | 300篇 |
1982年 | 219篇 |
1981年 | 234篇 |
1980年 | 187篇 |
1979年 | 236篇 |
1978年 | 219篇 |
1976年 | 173篇 |
1975年 | 159篇 |
1974年 | 153篇 |
1973年 | 164篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
63.
M. Laurin Council Jennifer M. Gardner Cynthia Helms Ying Liu Lynn A. Cornelius Anne M. Bowcock 《Experimental dermatology》2009,18(5):485-487
Abstract: The risks of developing malignant melanoma (MM) include ultraviolet irradiation and genetic factors. To examine the contribution of rare and common variation within known MM genes in sporadic US MM patients, coding regions of known MM susceptibility genes [cyclin-dependent kinase inhibitor 2A ( CDKN2A ), cyclin-dependent kinase 4, melanocortin 1 receptor ( MC1R ) and tyrosinase ( TYR )] were resequenced in 109–135 MM cases. The significance of variants was examined by comparing their frequencies in 390 cancer-free controls. Potential deleterious mutations in CDKN2A were found in two patients and two others had variants of unknown significance. Cases were more likely than controls to harbour the MC1R 'R' variants known or predicted to alter its function ( P = 0.002), particularly the R160W variant ( P = 0.0035). The associated TYR R402Q variant (rs1126809*A) was found in 29% of cases, similar to what has been described previously. One MM patient with a family history of MM, who had developed other skin cancers, was homozygous for a novel TYR variant (P406L) of unknown significance. Hence, rare variants in TYR may be important risk factors for skin cancer. 相似文献
64.
Betsy D. Kennard Susan G. Silva Simon Tonev Paul Rohde Jennifer L. Hughes Benedetto Vitiello Christopher J. Kratochvil John F. Curry Graham J. Emslie Mark Reinecke John March 《Journal of the American Academy of Child and Adolescent Psychiatry》2009,48(2):186-195
ObjectiveWe examine remission rate probabilities, recovery rates, and residual symptoms across 36 weeks in the Treatment for Adolescents with Depression Study (TADS).MethodThe TADS, a multisite clinical trial, randomized 439 adolescents with major depressive disorder to 12 weeks of treatment with fluoxetine, cognitive–behavioral therapy, their combination, or pill placebo. The pill placebo group, treated openly after week 12, was not included in the subsequent analyses. Treatment differences in remission rates and probabilities of remission over time are compared. Recovery rates in remitters at weeks 12 (acute phase remitters) and 18 (continuation phase remitters) are summarized. We also examined whether residual symptoms at the end of 12 weeks of acute treatment predicted later remission.ResultsAt week 36, the estimated remission rates for intention-to-treat cases were as follows: combination, 60%; fluoxetine, 55%; cognitive–behavioral therapy, 64%; and overall, 60%. Paired comparisons reveal that, at week 24, all active treatments converge on remission outcomes. The recovery rate at week 36 was 65% for acute phase remitters and 71% for continuation phase remitters, with no significant between-treatment differences in recovery rates. Residual symptoms at the end of acute treatment predicted failure to achieve remission at weeks 18 and 36.ConclusionsMost depressed adolescents in all three treatment modalities achieved remission at the end of 9 months of treatment. 相似文献
65.
Paul M. Brunet Jennifer J. Heisz Catherine J. Mondloch David I. Shore Louis A. Schmidt 《Journal of anxiety disorders》2009,23(7):909-914
Contrary to popular beliefs, a recent empirical study using eye tracking has shown that a non-clinical sample of socially anxious adults did not avoid the eyes during face scanning. Using eye-tracking measures, we sought to extend these findings by examining the relation between stable shyness and face scanning patterns in a non-clinical sample of 11-year-old children. We found that shyness was associated with longer dwell time to the eye region than the mouth, suggesting that some shy children were not avoiding the eyes. Shyness was also correlated with fewer first fixations to the nose, which is thought to reflect the typical global strategy of face processing. Present results replicate and extend recent work on social anxiety and face scanning in adults to shyness in children. These preliminary findings also provide support for the notion that some shy children may be hypersensitive to detecting social cues and intentions in others conveyed by the eyes. Theoretical and practical implications for understanding the social cognitive correlates and treatment of shyness are discussed. 相似文献
66.
Thomas R. Russell 《American journal of surgery》2009,197(6):826-827
In recent years, the surgical profession has attempted to incorporate into clinical practice certain techniques that the airline industry has used to improve safety. These mechanisms have proven to be valuable components of our efforts to ensure that surgical patients receive safe, high-quality care. However, as the authors of “Cost and workforce implications of subjecting all physicians to aviation industry work hour restrictions” note, it would be a mistake to extend aviation's work-hour restrictions to medicine, particularly to resident training programs. 相似文献
67.
68.
69.
Megan A. O’Grady Kristina Wilson Jennifer J. Harman 《The journal of primary prevention》2009,30(6):716-731
The purpose of this study was to evaluate a single-session peer-led safer sex intervention, based on the Information-Motivation-Behavioral
Skills theoretical model, for college students residing in campus residence halls. Participants (N = 108) were assigned to either an hour long control or 5-module intervention session. Compared to the control condition,
the intervention increased participants’ information and women’s subjective norms about preventative behavior. Both the control
and intervention sessions increased intentions to perform preventative behaviors (e.g., keep condoms available). These preliminary
results suggest that this intervention is promising for increasing constructs associated with safer sexual behavior and could
easily be implemented by residence hall staff. 相似文献
70.
Aaron M Kipp Jennifer A Lehman Richard A Bowen Patricia E Fox Michael R Stephens Kaci Klenk Nicholas Komar Michel L Bunning 《The American journal of tropical medicine and hygiene》2006,75(4):688-690
To better understand the potential environmental health risk presented by West Nile virus (WNV)-contaminated feces, we quantified the amount of WNV present in the feces of experimentally infected American crows (Corvus brachyrhynchos) and fish crows (Corvus ossifragus). Peak fecal titers ranged from 10(3.5) to 10(8.8) plaque-forming units (PFU)/g for 10 American crows and from 10(2.3) to 10(6.4) PFU/g for 10 fish crows. The presence of infectious WNV in bird feces indicates a potential for direct transmission of WNV. Thus, handlers of sick or dead birds should take appropriate precautions to avoid exposure to fecal material. 相似文献