首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1510917篇
  免费   106441篇
  国内免费   3371篇
耳鼻咽喉   20871篇
儿科学   49185篇
妇产科学   41382篇
基础医学   222825篇
口腔科学   42145篇
临床医学   130971篇
内科学   297190篇
皮肤病学   33099篇
神经病学   114270篇
特种医学   58609篇
外国民族医学   405篇
外科学   232437篇
综合类   32319篇
现状与发展   2篇
一般理论   393篇
预防医学   109792篇
眼科学   34594篇
药学   111370篇
  3篇
中国医学   3929篇
肿瘤学   84938篇
  2018年   15714篇
  2017年   12294篇
  2016年   13516篇
  2015年   15231篇
  2014年   21153篇
  2013年   32377篇
  2012年   43144篇
  2011年   45701篇
  2010年   27518篇
  2009年   25997篇
  2008年   43279篇
  2007年   46261篇
  2006年   46705篇
  2005年   45097篇
  2004年   43525篇
  2003年   41814篇
  2002年   41011篇
  2001年   72139篇
  2000年   73834篇
  1999年   62228篇
  1998年   16835篇
  1997年   14930篇
  1996年   15034篇
  1995年   14209篇
  1994年   13303篇
  1993年   12376篇
  1992年   48049篇
  1991年   46871篇
  1990年   45855篇
  1989年   44595篇
  1988年   40992篇
  1987年   40172篇
  1986年   38437篇
  1985年   36300篇
  1984年   26950篇
  1983年   22965篇
  1982年   13322篇
  1979年   24827篇
  1978年   17401篇
  1977年   14733篇
  1976年   14080篇
  1975年   15481篇
  1974年   18353篇
  1973年   17506篇
  1972年   16522篇
  1971年   15331篇
  1970年   14771篇
  1969年   13753篇
  1968年   12921篇
  1967年   11816篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
11.
12.
13.
Gestational trophoblastic neoplasia (GTN) patients are treated according to the eight-variable International Federation of Gynaecology and Obstetrics (FIGO) scoring system, that aims to predict first-line single-agent chemotherapy resistance. FIGO is imperfect with one-third of low-risk patients developing disease resistance to first-line single-agent chemotherapy. We aimed to generate simplified models that improve upon FIGO. Logistic regression (LR) and multilayer perceptron (MLP) modelling (n = 4191) generated six models (M1-6). M1, all eight FIGO variables (scored data); M2, all eight FIGO variables (scored and raw data); M3, nonimaging variables (scored data); M4, nonimaging variables (scored and raw data); M5, imaging variables (scored data); and M6, pretreatment hCG (raw data) + imaging variables (scored data). Performance was compared to FIGO using true and false positive rates, positive and negative predictive values, diagnostic odds ratio, receiver operating characteristic (ROC) curves, Bland-Altman calibration plots, decision curve analysis and contingency tables. M1-6 were calibrated and outperformed FIGO on true positive rate and positive predictive value. Using LR and MLP, M1, M2 and M4 generated small improvements to the ROC curve and decision curve analysis. M3, M5 and M6 matched FIGO or performed less well. Compared to FIGO, most (excluding LR M4 and MLP M5) had significant discordance in patient classification (McNemar's test P < .05); 55-112 undertreated, 46-206 overtreated. Statistical modelling yielded only small gains over FIGO performance, arising through recategorisation of treatment-resistant patients, with a significant proportion of under/overtreatment as the available data have been used a priori to allocate primary chemotherapy. Streamlining FIGO should now be the focus.  相似文献   
14.
Journal of Immigrant and Minority Health - COVID-19 has disproportionally affected underrepresented minorities (URM) and low-income immigrants in the United States. The aim of the study is to...  相似文献   
15.
16.
In this paper we present a coupled Finite Element Method – Boundary Element Method (FEM-BEM) approach for the solution of the free-boundary axi-symmetric plasma equilibrium problem. The proposed method, obtained from an improvement of the Hagenow-Lackner coupling method, allows to efficiently model the equilibrium problem in unbounded domains by discretizing only the plasma region; the external conductors can be modelled either as 2D or 3D models, according to the problem of interest. The paper explores different iterative methods for the solution of the nonlinear Grad-Shafranov equation, such as Picard, Newton-Raphson and Newton-Krylov, in order to provide a robust and reliable tool, able to handle large-scale problems (e.g. high resolution equilibria). This method has been implemented in the FRIDA code (FRee-boundary Integro-Differential Axisimmetric – https://github. om/matteobonotto/ FRIDA), together with a suitable Adaptive Integration Technique (AIT) for the computation of the source term. FRIDA has been successfully tested and validated against experimental data from RFX-mod device, and numerical equilibria of an ITER-like device.  相似文献   
17.
18.
19.
Introduction: Percutaneous renal mass biopsy has evolved over the last decade with improvements on previous pitfalls including low tissue yield, high non-diagnostic rates, and complications. As understanding of tumor biology and natural history of renal cortical neoplasms has improved, percutaneous renal mass biopsy is poised to have an expanding role in an area characterized by individualized management and refined risk stratification.

Areas covered: This review summarizes the evolution of renal mass biopsy to its current state with respect to outcomes, indications, and clinical guidelines.

Expert opinion: With improved understanding of differential biological potential of renal cortical neoplasms combined with technical improvements in diagnostic yield and accuracy, utilization of renal mass biopsy is becoming an important adjunct to patient care in a broad range of clinical scenarios, including active surveillance, thermal ablation, and use of primary systemic therapy in localized and advanced settings.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号