全文获取类型
收费全文 | 1237944篇 |
免费 | 101156篇 |
国内免费 | 22303篇 |
专业分类
耳鼻咽喉 | 14908篇 |
儿科学 | 36580篇 |
妇产科学 | 31392篇 |
基础医学 | 175395篇 |
口腔科学 | 31790篇 |
临床医学 | 125224篇 |
内科学 | 225957篇 |
皮肤病学 | 25139篇 |
神经病学 | 92521篇 |
特种医学 | 47599篇 |
外国民族医学 | 503篇 |
外科学 | 172493篇 |
综合类 | 66912篇 |
现状与发展 | 74篇 |
一般理论 | 411篇 |
预防医学 | 91978篇 |
眼科学 | 30442篇 |
药学 | 98774篇 |
293篇 | |
中国医学 | 17450篇 |
肿瘤学 | 75568篇 |
出版年
2021年 | 18029篇 |
2020年 | 14828篇 |
2019年 | 16372篇 |
2018年 | 20001篇 |
2017年 | 16576篇 |
2016年 | 17300篇 |
2015年 | 22540篇 |
2014年 | 29089篇 |
2013年 | 34254篇 |
2012年 | 47204篇 |
2011年 | 51871篇 |
2010年 | 31280篇 |
2009年 | 27281篇 |
2008年 | 41775篇 |
2007年 | 43431篇 |
2006年 | 44215篇 |
2005年 | 43220篇 |
2004年 | 36890篇 |
2003年 | 35157篇 |
2002年 | 32929篇 |
2001年 | 52088篇 |
2000年 | 53927篇 |
1999年 | 46821篇 |
1998年 | 15118篇 |
1997年 | 14097篇 |
1996年 | 13097篇 |
1995年 | 13183篇 |
1994年 | 11909篇 |
1993年 | 10349篇 |
1992年 | 34279篇 |
1991年 | 33173篇 |
1990年 | 32478篇 |
1989年 | 31106篇 |
1988年 | 28224篇 |
1987年 | 28193篇 |
1986年 | 26073篇 |
1985年 | 25134篇 |
1984年 | 18677篇 |
1983年 | 15656篇 |
1982年 | 9344篇 |
1979年 | 16903篇 |
1978年 | 12191篇 |
1977年 | 10281篇 |
1976年 | 9718篇 |
1975年 | 10153篇 |
1974年 | 12298篇 |
1973年 | 11827篇 |
1972年 | 10878篇 |
1971年 | 10104篇 |
1970年 | 9370篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
85.
Loren Saulsberry PhD Ankur Bhargava MD MPH Sharon Zeng BA Jason B. Gibbons PhD Cody Brannan MS Diane S. Lauderdale PhD Robert D. Gibbons PhD 《Health services research》2023,58(4):873-881
Objective
To derive and validate a new ecological measure of the social determinants of health (SDoH), calculable at the zip code or county level.Data Sources and Study Setting
The most recent releases of secondary, publicly available data were collected from national U.S. health agencies as well as state and city public health departments.Study Design
The Social Vulnerability Metric (SVM) was constructed from U.S. zip-code level measures (2018) from survey data using multidimensional Item Response Theory and validated using outcomes including all-cause mortality (2016), COVID-19 vaccination (2021), and emergency department visits for asthma (2018). The SVM was also compared with the existing Centers for Disease Control and Prevention's Social Vulnerability Index (SVI) to determine convergent validity and differential predictive validity.Data Collection/Extraction Methods
The data were collected directly from published files available to the public online from national U.S. health agencies as well as state and city public health departments.Principal Findings
The correlation between SVM scores and national age-adjusted county all-cause mortality was r = 0.68. This correlation demonstrated the SVM's robust validity and outperformed the SVI with an almost four-fold increase in explained variance (46% vs. 12%). The SVM was also highly correlated (r ≥ 0.60) to zip-code level health outcomes for the state of California and city of Chicago.Conclusions
The SVM offers a measurement tool improving upon the performance of existing SDoH composite measures and has broad applicability to public health that may help in directing future policies and interventions. The SVM provides a single measure of SDoH that better quantifies associations with health outcomes. 相似文献86.
Thomas Fuchs-Buder Sorin J. Brull Malin Jonsson Fagerlund J. Ross Renew Guy Cammu Glenn S. Murphy Michiel Warlé Matias Vested Béla Fülesdi Reka Nemes Malachy O. Columb Daniela Damian Peter J. Davis Hajime Iwasaki Lars I. Eriksson 《Acta anaesthesiologica Scandinavica》2023,67(8):994-1017
The set of guidelines for good clinical research practice in pharmacodynamic studies of neuromuscular blocking agents was developed following an international consensus conference in Copenhagen in 1996 (Viby-Mogensen et al., Acta Anaesthesiol Scand 1996, 40 , 59–74); the guidelines were later revised and updated following the second consensus conference in Stockholm in 2005 (Fuchs-Buder et al., Acta Anaesthesiol Scand 2007, 51 , 789–808). In view of new devices and further development of monitoring technologies that emerged since then, (e.g., electromyography, three-dimensional acceleromyography, kinemyography) as well as novel compounds (e.g., sugammadex) a review and update of these recommendations became necessary. The intent of these revised guidelines is to continue to help clinical researchers to conduct high-quality work and advance the field by enhancing the standards, consistency, and comparability of clinical studies. There is growing awareness of the importance of consensus-based reporting standards in clinical trials and observational studies. Such global initiatives are necessary in order to minimize heterogeneous and inadequate data reporting and to improve clarity and comparability between different studies and study cohorts. Variations in definitions of endpoints or outcome variables can introduce confusion and difficulties in interpretation of data, but more importantly, it may preclude building of an adequate body of evidence to achieve reliable conclusions and recommendations. Clinical research in neuromuscular pharmacology and physiology is no exception. 相似文献
87.
Guoliang Zhang & Tao Xiong 《Communications In Computational Physics》2022,32(1):126-155
We propose a high order finite difference linear scheme combined with a
high order bound preserving maximum-principle-preserving (MPP) flux limiter to
solve the incompressible flow system. For such problem with highly oscillatory structure but not strong shocks, our approach seems to be less dissipative and much less
costly than a WENO type scheme, and has high resolution due to a Hermite reconstruction. Spurious numerical oscillations can be controlled by the weak MPP flux
limiter. Numerical tests are performed for the Vlasov-Poisson system, the 2D guiding-center model and the incompressible Euler system. The comparison between the linear
and WENO type schemes, with and without the MPP flux limiter, will demonstrate the
good performance of our proposed approach. 相似文献
88.
Huo Jia Fu Lijun Jin Mengyuan Li Zhaoming Zhang Mingzhi 《Investigational new drugs》2022,40(3):537-545
Investigational New Drugs - Background Chemotherapy resistance is a main reason for treatment failure in extranodal NK/T-cell lymphoma (ENKTL). Interleukin-10 (IL-10) is closely related to... 相似文献
89.
Yue Wentao Zhang Enjie Liu Ruixia Zhang Yue Wang Chengrong Gao Shen Su Shaofei Gao Xiao Wu Qingqing Yang Xiaokui Papageorghiou Aris T. Yin Chenghong 《European journal of epidemiology》2022,37(3):295-304
European Journal of Epidemiology - The China birth cohort study (CBCS) is a prospective longitudinal, mega-cohort study and the first national-based birth cohort study, aiming to establish a birth... 相似文献
90.
目的 克隆菊花脑芳樟醇合酶基因CnTPS1的全长编码序列,利用原核系统表达融合蛋白,为进一步研究该基因在菊花脑萜类合成中的功能提供理论依据。方法 以菊花脑基因组数据为基础,设计特异性引物,PCR扩增CnTPS1的全长编码序列,利用生物信息学分析软件分析序列特征。利用qRT-PCR技术分析CnTPS1基因在不同组织中的基因表达量。构建原核表达载体,体外诱导目的蛋白表达。结果 CnTPS1编码序列全长1749bp,编码582个氨基酸;基因表达模式分析表明该基因在茎和管状花中表达量较高;原核表达系统能诱导出67.58kDa大小的蛋白。结论 首次从菊花脑中克隆得到一个芳樟醇合酶基因CnTPS1,运用生物信息学方法对其编码蛋白的理化性质、结构特征等进行了分析预测,分析了该基因的组织表达模式,并在原核表达系统中成功诱导表达出目标蛋白,这些结果将为菊花脑萜类合酶基因的功能以及萜类物质生物合成途径的解析提供理论依据。 相似文献