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   3535183篇
  免费   306141篇
  国内免费   14118篇
耳鼻咽喉   48460篇
儿科学   113611篇
妇产科学   93032篇
基础医学   562318篇
口腔科学   94577篇
临床医学   318508篇
内科学   628327篇
皮肤病学   93652篇
神经病学   306461篇
特种医学   138798篇
外国民族医学   494篇
外科学   545224篇
综合类   107968篇
现状与发展   24篇
一般理论   2399篇
预防医学   295780篇
眼科学   81129篇
药学   243649篇
  17篇
中国医学   10555篇
肿瘤学   170459篇
  2021年   55380篇
  2020年   35342篇
  2019年   58432篇
  2018年   72172篇
  2017年   54730篇
  2016年   60606篇
  2015年   74287篇
  2014年   108704篇
  2013年   174010篇
  2012年   102212篇
  2011年   103134篇
  2010年   118953篇
  2009年   122949篇
  2008年   89595篇
  2007年   93614篇
  2006年   103811篇
  2005年   99137篇
  2004年   100376篇
  2003年   90578篇
  2002年   79847篇
  2001年   118335篇
  2000年   111790篇
  1999年   107730篇
  1998年   66787篇
  1997年   64359篇
  1996年   62198篇
  1995年   57612篇
  1994年   51541篇
  1993年   48093篇
  1992年   73902篇
  1991年   69890篇
  1990年   65554篇
  1989年   64308篇
  1988年   59196篇
  1987年   57980篇
  1986年   54517篇
  1985年   54338篇
  1984年   49268篇
  1983年   44694篇
  1982年   41778篇
  1981年   39145篇
  1980年   36831篇
  1979年   39915篇
  1978年   35282篇
  1977年   31876篇
  1976年   29288篇
  1975年   27660篇
  1974年   28818篇
  1973年   27887篇
  1972年   26180篇
排序方式: 共有10000条查询结果,搜索用时 781 毫秒
71.
Two Janus-associated kinase inhibitors (JAKi) (initially ruxolitinib and, more recently, fedratinib) have been approved as treatment options for patients who have intermediate-risk and high-risk myelofibrosis (MF), with pivotal trials demonstrating improvements in spleen volume, disease symptoms, and quality of life. At the same time, however, clinical trial experiences with JAKi agents in MF have demonstrated a high frequency of discontinuations because of adverse events or progressive disease. In addition, overall survival benefits and clinical and molecular predictors of response have not been established in this population, for which the disease burden is high and treatment options are limited. Consistently poor outcomes have been documented after JAKi discontinuation, with survival durations after ruxolitinib ranging from 11 to 16 months across several studies. To address such a high unmet therapeutic need, various non-JAKi agents are being actively explored (in combination with ruxolitinib in first-line or salvage settings and/or as monotherapy in JAKi-pretreated patients) in phase 3 clinical trials, including pelabresib (a bromodomain and extraterminal domain inhibitor), navitoclax (a B-cell lymphoma 2/B-cell lymphoma 2-xL inhibitor), parsaclisib (a phosphoinositide 3-kinase inhibitor), navtemadlin (formerly KRT-232; a murine double-minute chromosome 2 inhibitor), and imetelstat (a telomerase inhibitor). The breadth of data expected from these trials will provide insight into the ability of non-JAKi treatments to modify the natural history of MF.  相似文献   
72.
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   
73.
Vaccination is a vital health care initiative to prevent individual and population infection. To increase vaccination rates the federal government implemented the ‘No Jab, No Pay’ policy, where eligibility for several government benefits required children to be fully vaccinated by removing ‘conscientious objections’ and expanding the age range of children whose families receive benefits. This study assesses the impact of this policy at a local area within a single medical practice community in NSW, Australia. A retrospective clinical audit was performed between 2012 and 2017 on a single general practice's vaccination records for children ≤19 years. Catch-up vaccinations were assessed based on age at vaccination. Incidence of catch-up vaccinations was assessed for each of four years before and two years after the implementation of the ‘No Jab, No Pay’ policy in January 2016, along with the age of children and vaccination(s) given. Catch-up vaccinations were assessed temporally either side of implementation of ‘No Jab, No Pay’. Comparing the average annual vaccination catch-up incidence rate of 6.2% pre-implementation (2012–2015), there was an increase to 9.2% in 2016 (p < .001) and 7.8% in 2017 (p = .027). Secondary outcome measurement of catch-up vaccination incidence rates before (2012–2015) and after (2016–2017) ‘No Jab, No Pay’ implementation showed statistically significant increases for children aged 8–11 years (3.2%–5.6%, p = .038), 12–15 years (7.5%–14.7%, p < .001) and 16–19 years (3.3%–10.2%, p < .001) along with a statistically significant reduction in children aged 1–3 years (11.4%–6.2%, p = .015). Also, catch-up rates for DTPa significantly increased after program implementation. This study demonstrates that the Australian federal government vaccination policy ‘No Jab, No Pay’ was coincident with an increase in catch-up vaccinations within a rural NSW community served by one medical practice, especially for older children.  相似文献   
74.
Patient navigation is a strategy for overcoming barriers to reduce disparities and to improve access and outcomes. The aim of this umbrella review was to identify, critically appraise, synthesize, and present the best available evidence to inform policy and planning regarding patient navigation across the cancer continuum. Systematic reviews examining navigation in cancer care were identified in the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Cumulative Index of Nursing and Allied Health (CINAHL), Epistemonikos, and Prospective Register of Systematic Reviews (PROSPERO) databases and in the gray literature from January 1, 2012, to April 19, 2022. Data were screened, extracted, and appraised independently by two authors. The JBI Critical Appraisal Checklist for Systematic Review and Research Syntheses was used for quality appraisal. Emerging literature up to May 25, 2022, was also explored to capture primary research published beyond the coverage of included systematic reviews. Of the 2062 unique records identified, 61 systematic reviews were included. Fifty-four reviews were quantitative or mixed-methods reviews, reporting on the effectiveness of cancer patient navigation, including 12 reviews reporting costs or cost-effectiveness outcomes. Seven qualitative reviews explored navigation needs, barriers, and experiences. In addition, 53 primary studies published since 2021 were included. Patient navigation is effective in improving participation in cancer screening and reducing the time from screening to diagnosis and from diagnosis to treatment initiation. Emerging evidence suggests that patient navigation improves quality of life and patient satisfaction with care in the survivorship phase and reduces hospital readmission in the active treatment and survivorship care phases. Palliative care data were extremely limited. Economic evaluations from the United States suggest the potential cost-effectiveness of navigation in screening programs.  相似文献   
75.
76.
Cancer Causes & Control - Congenital malformations are strong risk factors for childhood cancer. Our objective was to determine whether cancer survival differs by birth defect status among...  相似文献   
77.
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   
78.
79.
80.
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