全文获取类型
收费全文 | 4038篇 |
免费 | 421篇 |
国内免费 | 102篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 147篇 |
妇产科学 | 53篇 |
基础医学 | 470篇 |
口腔科学 | 63篇 |
临床医学 | 547篇 |
内科学 | 866篇 |
皮肤病学 | 193篇 |
神经病学 | 256篇 |
特种医学 | 223篇 |
外科学 | 490篇 |
综合类 | 131篇 |
一般理论 | 2篇 |
预防医学 | 455篇 |
眼科学 | 36篇 |
药学 | 448篇 |
中国医学 | 3篇 |
肿瘤学 | 165篇 |
出版年
2021年 | 58篇 |
2020年 | 34篇 |
2019年 | 48篇 |
2018年 | 54篇 |
2017年 | 37篇 |
2016年 | 63篇 |
2015年 | 56篇 |
2014年 | 75篇 |
2013年 | 123篇 |
2012年 | 169篇 |
2011年 | 183篇 |
2010年 | 122篇 |
2009年 | 95篇 |
2008年 | 190篇 |
2007年 | 217篇 |
2006年 | 184篇 |
2005年 | 192篇 |
2004年 | 160篇 |
2003年 | 150篇 |
2002年 | 129篇 |
2001年 | 142篇 |
2000年 | 140篇 |
1999年 | 116篇 |
1998年 | 83篇 |
1997年 | 70篇 |
1996年 | 59篇 |
1995年 | 68篇 |
1994年 | 54篇 |
1993年 | 68篇 |
1992年 | 91篇 |
1991年 | 82篇 |
1990年 | 90篇 |
1989年 | 74篇 |
1988年 | 85篇 |
1987年 | 72篇 |
1986年 | 81篇 |
1985年 | 94篇 |
1984年 | 59篇 |
1983年 | 69篇 |
1982年 | 41篇 |
1981年 | 27篇 |
1980年 | 36篇 |
1979年 | 42篇 |
1978年 | 42篇 |
1977年 | 39篇 |
1976年 | 38篇 |
1975年 | 44篇 |
1974年 | 49篇 |
1973年 | 34篇 |
1972年 | 32篇 |
排序方式: 共有4561条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
Two parallel literatures on the physical activity (PA) identity and schema constructs have the potential to supplement traditional social cognitive approaches used for PA promotion. The purpose of this paper was to review schema/identity research and appraise its relationship with PA via meta-analysis followed by thematic analyses of its correlates, as well as its proposed mechanisms on PA. Eligible studies were from English, peer-reviewed published articles that examined identity and/or schema in the context of PA. Searches were completed in June 2015 in five databases. Sixty-two independent data-sets (32 available for meta-analysis), primarily of modest quality, were identified. Results of the random effects meta-analysis showed that the point-estimate between identity/schema and behaviour was r?=?.44 (CI?=?.39?.48), and invariant to selected study characteristics. Thematic review showed that identity/schema was associated with commitment, ability, affective judgments, identified/integrated regulation and social comparison and predicted intention, self-regulatory efficacy, and self-regulation strategy use. It had reliable evidence as a moderator of the intention–behavior relationship, was associated with increases in the speed of processing of relevant information and created negative affect under hypothetical identity–behavior discrepant situations. While this initial research is promising, more rigorous research designs, including interventions to increase identity/schema, are warranted. 相似文献
85.
For persons living with HIV, health-related quality of life (HRQOL) may be threatened by physical and mental conditions but may be protected by positive psychological traits. We performed an exploratory look at the risk and protective factors for HRQOL in older adults living with HIV. Cross-sectional analyses of baseline data from the Rush Center of Excellence on Disparities in HIV and Aging (CEDHA), a community-based cohort of persons ages ≥50 living with HIV (n?=?176) were performed. Analyses examined the relationship between risk/protective factors and two outcomes (i.e., self-reported health status [SRHS] and the healthy days index [HDI]). Having good/excellent health was associated with being a non-smoker (p?=?0.002), greater purpose in life (p?=?0.006), higher education (p?=?0.007), fewer depressive symptoms (p?=?0.004), fewer disabilities (p?=?0.000), and less loneliness (p?=?0.002) in bivariate analyses. Males (p?=?0.03) and African Americans/Blacks (p?=?0.03) reported higher HDI. Fewer depressive symptoms (p?=?0.000), disabilities (p?=?0.002), adverse life events (p?=?0.0103), and loneliness (p?=?0.000) were associated with higher HDI in bivariate analyses. In a logistic regression model, greater purpose in life, fewer disabilities, and being a non-smoker were associated with better SRHS after adjusting for covariates. For African Americans/Blacks, having fewer depressive symptoms and disabilities were associated with higher HDI after adjusting for covariates. Disabilities, depression, smoking status, race/ethnicity, and purpose in life were significantly associated with HRQOL. Findings support the need for research to examine the influence of cultural interpretations of life quality and focus on promoting physical function, smoking cessation, and psychological wellness in persons aging with HIV. 相似文献
86.
Rosemary Pimm Corneel Vandelanotte Ryan E. Rhodes Camille Short Mitch J. Duncan 《Behavioral medicine (Washington, D.C.)》2013,39(4):248-253
Physical activity is partly regulated by automatic processes such as habits (ie, well-learned responses to cues), but it remains unclear what cues trigger these processes. This study examined the relations of physical activity automaticity and behavior with the consistency of people, activity, routine, location, time, and mood cues present upon initiation of physical activity behavior. Australian adults (N = 1,244, 627 female, M age = 55 years) reported their physical activity automaticity, behavior, and the degree of consistency of these cues each time they start a physical activity behavior. Multiple regression models, which accounted for gender and age, revealed that more consistent routine and mood cues were linked to more physical activity automaticity; whereas more consistent time and people cues were linked to more physical activity behavior. Interventions may more effectively translate into long-lasting physical activity habits if they draw people's attention to the salient cues of time, people, routine, and mood. 相似文献
87.
88.
89.
Jennifer A. Fike Cecilia A. Hennessy Michael L. Kennedy Olin E. Rhodes Jr 《Conservation Genetics Resources》2013,5(3):679-681
The eastern gray squirrel (Sciurus carolinensis) often serves as a model organism for investigations of wildlife ecology. The authors developed 11 polymorphic microsatellite markers to facilitate future research questions. The number of alleles per locus ranged from three to ten and observed heterozygosities ranged from 0.143 to 0.786. Interspecific screening revealed that several loci were polymorphic in Sciurus niger (eight loci) and Tamiasciurus hudsonicus (four loci). These markers will aid in investigations of movements, social structure and mating tactics of eastern gray squirrel populations. 相似文献
90.
D.P. Miller J.V. McDowell D.V. Rhodes A. Allard M. Caimano J.K. Bell R.T. Marconi 《Molecular oral microbiology》2013,28(4):316-330
Treponema denticola is an anaerobic spirochete whose abundance in the subgingival crevice correlates with the development and severity of periodontal disease. The ability of T. denticola to survive and thrive in the hostile environment of the periodontal pocket is due, at least in part, to its ability to bind factor H (FH), a negative regulator of the alternative complement pathway. The FH binding protein of T. denticola has been identified as FhbB and its atomic structure has been determined. The interaction of FH with T. denticola is unique in that FH bound to the cell surface is cleaved by the T. denticola protease, dentilisin. It has been postulated that FH cleavage by T. denticola leads to immune dysregulation in periodontal pockets. In this study, we conduct a comparative assessment of the sequence, properties, structure and ligand binding kinetics of the FhbB proteins of strains 33521 and 35405. The biological outcome of the interaction of these strains with FH could differ significantly as 33521 lacks dentilisin activity. The data presented here offer insight into our understanding of the interactions of T. denticola with the host and its potential to influence disease progression. 相似文献