全文获取类型
收费全文 | 25389篇 |
免费 | 2333篇 |
国内免费 | 73篇 |
专业分类
耳鼻咽喉 | 261篇 |
儿科学 | 589篇 |
妇产科学 | 343篇 |
基础医学 | 3091篇 |
口腔科学 | 812篇 |
临床医学 | 3265篇 |
内科学 | 5454篇 |
皮肤病学 | 617篇 |
神经病学 | 1857篇 |
特种医学 | 1038篇 |
外科学 | 3584篇 |
综合类 | 515篇 |
一般理论 | 24篇 |
预防医学 | 2678篇 |
眼科学 | 360篇 |
药学 | 1992篇 |
中国医学 | 23篇 |
肿瘤学 | 1292篇 |
出版年
2021年 | 365篇 |
2020年 | 208篇 |
2019年 | 343篇 |
2018年 | 375篇 |
2017年 | 273篇 |
2016年 | 340篇 |
2015年 | 394篇 |
2014年 | 529篇 |
2013年 | 833篇 |
2012年 | 1129篇 |
2011年 | 1123篇 |
2010年 | 635篇 |
2009年 | 597篇 |
2008年 | 1041篇 |
2007年 | 1055篇 |
2006年 | 1104篇 |
2005年 | 1098篇 |
2004年 | 1026篇 |
2003年 | 973篇 |
2002年 | 975篇 |
2001年 | 983篇 |
2000年 | 1008篇 |
1999年 | 854篇 |
1998年 | 339篇 |
1997年 | 283篇 |
1996年 | 276篇 |
1995年 | 266篇 |
1994年 | 218篇 |
1993年 | 227篇 |
1992年 | 611篇 |
1991年 | 636篇 |
1990年 | 585篇 |
1989年 | 524篇 |
1988年 | 508篇 |
1987年 | 487篇 |
1986年 | 482篇 |
1985年 | 487篇 |
1984年 | 346篇 |
1983年 | 297篇 |
1982年 | 220篇 |
1981年 | 208篇 |
1979年 | 324篇 |
1978年 | 238篇 |
1977年 | 204篇 |
1975年 | 168篇 |
1974年 | 214篇 |
1973年 | 204篇 |
1972年 | 169篇 |
1971年 | 192篇 |
1970年 | 170篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
Catherine M Lowndes Ellie Sherrard-Smith Ciara Dangerfield Yoon H Choi Nathan Green Mark Jit Rob D Marshall Catherine Mercer Emma Harding-Esch Anthony Nardone Rebecca Howell-Jones John Bason Owen A Johnson Christopher P Price Charlotte A Gaydos S Tariq Sadiq Peter J White 《Lancet》2014
BackgroundChlamydia trachomatis is the most commonly diagnosed bacterial sexually transmitted infection in Britain. Present standards specify treatment within 14 days of testing positive; point-of-care testing (POCT) can eliminate this delay and potentially reduce loss to follow-up; its greater convenience might increase testing. 90-min nucleic acid amplification tests are the best available POCTs for chlamydia, with alternatives under development. However, cost-effectiveness depends on cost-per-test, sensitivity and specificity, and the effect of POCT on transmission.MethodsWe developed a user-friendly web-based method, based on a transmission-dynamic model for chlamydia, to assess the epidemiological impact and cost-effectiveness of introducing POCT in different local settings. The model uses behavioural and prevalence data from the National Survey of Sexual Attitudes and Lifestyles, and Public Health England surveillance data; these data inform on local-level variation, which is represented by sampling parameter values from within their ranges of uncertainty and selecting parameter sets that reproduce local coverage and diagnosis rates. The user can select different local settings, and vary sensitivity and specificity for the tests, specify costs (fixed and unit costs, including staff time), and then assess the effect of introducing POCT in different clinical services by comparison with a situation with no POCT. In the model, presumptive treatment is represented, which we expect to be reduced with the introduction of POCT because test results would be rapidly available to guide treatment.FindingsChanges in numbers of infections and diagnoses occurring under different scenarios (including conventional testing) were estimated, with uncertainty ranges, allowing calculation of total costs, and cost per infection (and serious sequelae) averted, while accommodating the considerable variation in chlamydia testing coverage, positivity, and diagnosis rates. Potential changes in sexual behaviour between test and treatment could determine the relative contribution of increased treatment rates and reduced treatment delay to the reduction in prevalence as a consequence of POCT.InterpretationThe effect of POCT was dependent on both the test performance characteristics and the assumptions about the implementation of the test across local services. Exploration of many uncertainties surrounding chlamydia epidemiology and screening implementation is possible with this model. This method can complement local and national knowledge, and contribute to local-level management of chlamydia infection.FundingInnovate UK (Technology Strategy Board), UK Medical Research Council, and the National Institute for Health Research. The Electronic Self-Testing Instruments for Sexually Transmitted Infection (eSTI2) Consortium eSTI2 is Funded under the UKCRC Translational Infection Research (TIR) Initiative supported by the Medical Research Council (Grant Number G0901608) with contributions to the Grant from the Biotechnology and Biological Sciences Research Council, the National Institute for Health Research on behalf of the Department of Health, the Chief Scientist Office of the Scottish Government Health Directorates, and the Wellcome Trust 相似文献
943.
Silent cerebral infarction,income, and grade retention among students with sickle cell anemia 下载免费PDF全文
Allison A. King Mark J. Rodeghier Julie Ann Panepinto John J. Strouse James F. Casella Charles T. Quinn Michael M. Dowling Sharada A. Sarnaik Alexis A. Thompson Gerald M. Woods Caterina P. Minniti Rupa C. Redding‐Lallinger Melanie Kirby‐Allen Fenella J. Kirkham Robert McKinstry Michael J. Noetzel Desiree A. White Janet K. Kwiatkowski Thomas H. Howard Karen A. Kalinyak Baba Inusa Melissa M. Rhodes Mark E. Heiny Ben Fuh Jason M. Fixler Mae O. Gordon Michael R. DeBaun 《American journal of hematology》2014,89(10):E188-E192
Children with sickle cell anemia have a higher‐than‐expected prevalence of poor educational attainment. We test two key hypotheses about educational attainment among students with sickle cell anemia, as measured by grade retention and use of special education services: (1) lower household per capita income is associated with lower educational attainment; (2) the presence of a silent cerebral infarct is associated with lower educational attainment. We conducted a multicenter, cross‐sectional study of cases from 22 U.S. sites included in the Silent Infarct Transfusion Trial. During screening, parents completed a questionnaire that included sociodemographic information and details of their child's academic status. Of 835 students, 670 were evaluable; 536 had data on all covariates and were used for analysis. The students' mean age was 9.4 years (range: 5–15) with 52.2% male; 17.5% of students were retained one grade level and 18.3% received special education services. A multiple variable logistic regression model identified that lower household per capita income (odds ratio [OR] of quartile 1 = 6.36, OR of quartile 2 = 4.7, OR of quartile 3 = 3.87; P = 0.001 for linear trend), age (OR = 1.3; P < 0.001), and male gender (OR, 2.2; P = 0.001) were associated with grade retention; silent cerebral infarct (P = 0.31) and painful episodes (P = 0.60) were not. Among students with sickle cell anemia, household per capita income is associated with grade retention, whereas the presence of a silent cerebral infarct is not. Future educational interventions will need to address both the medical and socioeconomic issues that affect students with sickle cell anemia. Am. J. Hematol. 89:E188–E192, 2014. © 2014 Wiley Periodicals, Inc. 相似文献
944.
Jolene Sanders Kitty Wilkes Harris Jessica Nelson William L. White Thomas F. McGovern 《Alcoholism treatment quarterly》2014,32(2-3):248-270
Women and men share similar as well as different strategies in developing their spirituality as part of their overall 12-Step experience. Special attention is paid to gender differences to account for a variety of spiritual experiences in recovery. The language and use of metaphors as women and men work the 12 Steps in achieving a “spiritual awakening” is explored, recognizing the predominantly male ethos of Alcoholics Anonymous since its inception. The influence of age in expressions of spirituality, distinguishing between young adults, middle-age adults, and older adults, is referenced. Need for further understanding of gender differences, with a focus on the spiritual dimensions of recovery, is recommended. 相似文献
945.
David J. Whellan Pierluigi Tricoci Edmond Chen Zhen Huang David Leibowitz Pascal Vranckx Gregary D. Marhefka Claes Held Jose C. Nicolau Robert F. Storey Witold Ruzyllo Kurt Huber Peter Sinnaeve A. Teddy Weiss Jean-Pierre Dery David J. Moliterno Frans Van de Werf Philip E. Aylward Harvey D. White Paul W. Armstrong Lars Wallentin John Strony Robert A. Harrington Kenneth W. Mahaffey 《Journal of the American College of Cardiology》2014
946.
947.
948.
949.
Kevin W. McConeghy PharmD MS Elizabeth White APRN PhD Orestis A. Panagiotou MD PhD Christopher Santostefano RN BSN Christopher Halladay ScM Richard A. Feifer MD MPH Carolyn Blackman MD James L. Rudolph MD Vince Mor PhD Stefan Gravenstein MD MPH 《Journal of the American Geriatrics Society》2020,68(12):2716-2720
950.