全文获取类型
收费全文 | 1217739篇 |
免费 | 93516篇 |
国内免费 | 4404篇 |
专业分类
耳鼻咽喉 | 17972篇 |
儿科学 | 32239篇 |
妇产科学 | 34172篇 |
基础医学 | 174041篇 |
口腔科学 | 36831篇 |
临床医学 | 103451篇 |
内科学 | 238032篇 |
皮肤病学 | 25345篇 |
神经病学 | 95913篇 |
特种医学 | 48506篇 |
外国民族医学 | 253篇 |
外科学 | 192810篇 |
综合类 | 33033篇 |
现状与发展 | 3篇 |
一般理论 | 322篇 |
预防医学 | 83336篇 |
眼科学 | 29491篇 |
药学 | 94086篇 |
1篇 | |
中国医学 | 3690篇 |
肿瘤学 | 72132篇 |
出版年
2018年 | 11620篇 |
2016年 | 10117篇 |
2015年 | 11978篇 |
2014年 | 16932篇 |
2013年 | 24274篇 |
2012年 | 33122篇 |
2011年 | 34278篇 |
2010年 | 20144篇 |
2009年 | 18951篇 |
2008年 | 31806篇 |
2007年 | 34455篇 |
2006年 | 34130篇 |
2005年 | 32929篇 |
2004年 | 31979篇 |
2003年 | 30820篇 |
2002年 | 29581篇 |
2001年 | 60462篇 |
2000年 | 61759篇 |
1999年 | 51936篇 |
1998年 | 13884篇 |
1997年 | 12365篇 |
1996年 | 11901篇 |
1995年 | 11142篇 |
1994年 | 10458篇 |
1993年 | 9743篇 |
1992年 | 41300篇 |
1991年 | 39721篇 |
1990年 | 38660篇 |
1989年 | 37626篇 |
1988年 | 34880篇 |
1987年 | 34082篇 |
1986年 | 32084篇 |
1985年 | 30790篇 |
1984年 | 22851篇 |
1983年 | 19298篇 |
1982年 | 11381篇 |
1981年 | 10256篇 |
1979年 | 21923篇 |
1978年 | 15278篇 |
1977年 | 13008篇 |
1976年 | 11466篇 |
1975年 | 12647篇 |
1974年 | 15532篇 |
1973年 | 14834篇 |
1972年 | 14229篇 |
1971年 | 13348篇 |
1970年 | 12631篇 |
1969年 | 12355篇 |
1968年 | 11042篇 |
1967年 | 10089篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
Alan. B. Franklin Sarah N. Bevins Jeremy W. Ellis Ryan S. Miller Susan A. Shriner J. Jeffrey Root Daniel P. Walsh Thomas J. Deliberto 《Transboundary and Emerging Diseases》2019,66(2):705-714
Using data on waterfowl band recoveries, we identified spatially explicit hotspots of concentrated waterfowl movement to predict occurrence and spatial spread of a novel influenza A virus (clade 2.3.4.4) introduced from Asia by waterfowl from an initial outbreak in North America in November 2014. In response to the outbreak, the hotspots of waterfowl movement were used to help guide sampling for clade 2.3.4.4 viruses in waterfowl as an early warning for the US poultry industry during the outbreak . After surveillance sampling of waterfowl, we tested whether there was greater detection of clade 2.3.4.4 viruses inside hotspots. We found that hotspots defined using kernel density estimates of waterfowl band recoveries worked well in predicting areas with higher prevalence of the viruses in waterfowl. This approach exemplifies the value of ecological knowledge in predicting risk to agricultural security. 相似文献
94.
95.
Toshiro Hara Rony Chanoch-Myers Nathan D. Mathewson Chad Myskiw Lyla Atta Lillian Bussema Stephen W. Eichhorn Alissa C. Greenwald Gabriela S. Kinker Christopher Rodman L. Nicolas Gonzalez Castro Hiroaki Wakimoto Orit Rozenblatt-Rosen Xiaowei Zhuang Jean Fan Tony Hunter Inder M. Verma Kai W. Wucherpfennig Itay Tirosh 《Cancer cell》2021,39(6):779-792.e11
96.
Stefaniuk Catherine M. Schlegelmilch June Meyerson Howard J. Harding Clifford V. Maitta Robert W. 《Journal of thrombosis and thrombolysis》2022,53(4):950-953
Journal of Thrombosis and Thrombolysis - Over the last few years data from our group have indicated that α-synuclein is important in development of immune cells as well as potentially... 相似文献
97.
98.
Yinong Young-Xu Julia Thornton Snider Robertus van Aalst Salaheddin M. Mahmud Edward W. Thommes Jason K.H. Lee David P. Greenberg Ayman Chit 《Vaccine》2019,37(11):1484-1490
Background
Observational studies of the relative effectiveness of influenza vaccines are essential for public health decision making. Their estimates, however, are subject to bias due to unmeasured confounders. Instrumental variable (IV) methods can control for observed and unobserved confounders.Methods
We used linked electronic medical record databases in the Veterans Health Administration (VHA) as well as Medicare administrative files to examine the relative vaccine effectiveness (rVE) of high-dose influenza vaccine (HD) versus standard-dose influenza vaccines (SD) in preventing hospitalizations among VHA-enrolled Veterans ≥65?years of age during 5 influenza seasons (2010–2011 through 2014–2015). Using multivariable IV Poisson regression modeling to address unmeasured confounding and bias, we analyzed the data by each season and through longitudinal analysis of all five seasons.Findings
We included 3,638,924 person–influenza seasons of observation where 158,636 (4%) were among HD vaccine recipients and 3,480,288 (96%) were among SD vaccine recipients. Of the 1,728,562 Veterans, 1,702,824 (98.5%) were male and 1,299,412 (75%) were non-Hispanic white. Based on the longitudinal analysis of all five seasons, the IV-adjusted rVE estimate of HD vs. SD was 10% (95% CI, 8–12%) against all-cause hospitalization; 18% (95% CI, 15–21%) against cardiorespiratory-associated hospitalization; and 14% (95% CI, 6–22%) against influenza/pneumonia-associated hospitalization. The findings by season were similar.Interpretation
Our analysis of VHA clinical data collected from approximately 1.7 million Veterans 65?years and older during five seasons demonstrates that high-dose influenza vaccine is more effective than standard-dose influenza vaccines in preventing influenza- or pneumonia-associated hospitalizations, cardiorespiratory hospitalizations, and all-cause hospitalizations. 相似文献99.
Katherine M. Duszynski Nicole L. Pratt John W. Lynch Jesia G. Berry Michael S. Gold 《Vaccine》2019,37(2):280-288
Objective
To determine whether differences in combination DTaP vaccine types at 2, 4 and 6?months of age were associated with mortality (all-cause or non-specific), within 30?days of vaccination.Design
Observational nationwide cohort study.Setting
Linked population data from the Australian Childhood Immunisation Register and National Death Index.Participants
Australian infants administered a combination trivalent, quadrivalent or hexavalent DTaP vaccine (DTaP types) between January 1999 and December 2010 at 2, 4 and 6?months as part of the primary vaccination series. The study population included 2.9, 2.6, & 2.3?million children in the 2, 4 and 6?month vaccine cohorts, respectively.Main outcome measures
Infants were evaluated for the primary outcome of all-cause mortality within 30?days. A secondary outcome was non-specific mortality (unknown cause of death) within 30?days of vaccination. Non-specific mortality was defined as underlying or other cause of death codes, R95 ‘Sudden infant death syndrome’, R96 ‘Other sudden death, cause unknown’, R98 ‘Unattended death’, R99 ‘Other ill-defined and unspecified cause of mortality’ or where no cause of death was recorded.Results
The rate of 30?day all-cause mortality was low and declined from 127.4 to 59.3 deaths per 100,000 person-years between 2 and 6?month cohorts. When compared with trivalent DTaP vaccines, no elevated risk in all-cause or non-specific mortality was seen with any quadrivalent or hexavalent DTaP vaccines, for any cohort.Conclusion
Use of routine DTaP combination vaccines with differing disease antigens administered during the first six months of life is not associated with infant mortality. 相似文献100.
Tarandovskiy Ivan D. Rajabi Ali A. Karnaukhova Elena Buehler Paul W. 《Journal of thrombosis and thrombolysis》2019,48(1):81-87
Journal of Thrombosis and Thrombolysis - C1-inhibitor (C1INH) was shown to enhance thrombin generation (TG) in the presence of thrombomodulin (TM) by reducing production of activated protein C.... 相似文献