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   35219篇
  免费   2347篇
  国内免费   1119篇
耳鼻咽喉   147篇
儿科学   613篇
妇产科学   361篇
基础医学   3856篇
口腔科学   742篇
临床医学   4160篇
内科学   6799篇
皮肤病学   420篇
神经病学   2218篇
特种医学   613篇
外国民族医学   4篇
外科学   2432篇
综合类   5024篇
现状与发展   5篇
预防医学   1269篇
眼科学   200篇
药学   7766篇
  9篇
中国医学   1151篇
肿瘤学   896篇
  2023年   432篇
  2022年   706篇
  2021年   1260篇
  2020年   1022篇
  2019年   964篇
  2018年   893篇
  2017年   955篇
  2016年   919篇
  2015年   1132篇
  2014年   1935篇
  2013年   2442篇
  2012年   1918篇
  2011年   2188篇
  2010年   1747篇
  2009年   1584篇
  2008年   1582篇
  2007年   1653篇
  2006年   1414篇
  2005年   1281篇
  2004年   1116篇
  2003年   1000篇
  2002年   829篇
  2001年   761篇
  2000年   681篇
  1999年   597篇
  1998年   546篇
  1997年   567篇
  1996年   509篇
  1995年   491篇
  1994年   466篇
  1993年   442篇
  1992年   432篇
  1991年   390篇
  1990年   415篇
  1989年   366篇
  1988年   318篇
  1987年   290篇
  1986年   288篇
  1985年   332篇
  1984年   274篇
  1983年   219篇
  1982年   272篇
  1981年   194篇
  1980年   182篇
  1979年   141篇
  1978年   97篇
  1977年   97篇
  1976年   74篇
  1975年   64篇
  1974年   54篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
1.
2.
When the COVID-19 pandemic hit, blood transfusion services worldwide started collection of convalescent plasma as early as possible, as exemplified by the response in Norway. There were challenges related to donor selection, donor safety, testing for relevant antibodies and indications for and dosing of the convalescent plasma. As more knowledge became available, the product quality was more standardised. Multiple case reports, observational studies and some randomized studies were published during the pandemic, as well as laboratory studies reporting different approaches to antibody testing. The results were conflicting and the importance of convalescent plasma was disputed.Even though there has been strong international collaboration with involvement of many key organisations, we may better prepare for the next pandemic. An even stronger, more formalised collaboration between these organisations could provide more clear evidence of the importance of convalescent plasma, based on the principles of passive immunisation.  相似文献   
3.
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   
4.
We review the spectrum of cutaneous disorders associated with inflammatory and neoplastic plasmacytic pathology. Because plasma cells are derived from B‐lymphocytes our overview includes discussion of certain lymphoplasmacytic proliferations. It is structured along histopathological lines, addressing conditions characterized by (a) cutaneous plasma cell infiltrates, (b) deposits of plasma cell products or their derivatives in the skin and (c) miscellaneous, poorly understood cutaneous complications of plasmacytic disorders. Lesions arising primarily in the skin and those due to cutaneous involvement by multisystem disorders are addressed. The range includes a spectrum of tumefactive and circulatory manifestations. We highlight key clinical and pathological features of the different conditions and outline recent advances in our understanding of these entities. By emphasizing the dermatopathological characteristics of this spectrum of disorders we hope to hone the diagnostic accuracy of practitioners in the field.  相似文献   
5.
目的 探讨健脾消积颗粒治疗脾胃湿热型功能性消化不良的临床疗效及其对脑肠肽的影响。方法 按照随机数字表法将2018年2月-2019年2月我院收治的80例功能性消化不良患儿均分为对照组和观察组,对照组给予多潘立酮片治疗,观察组在对照组基础上加用健脾消积颗粒治疗,比较2组治疗效果。结果 治疗后2组主要临床症状积分均显著下降,观察组下降更为明显。观察组总有效率为95%,显著高于对照组的79.5%。观察组治疗后胃电节律异常例数明显低于对照组,治疗后2组胃动素(MTL)显著上升,神经肽Y(NPY)、神经降压素(NT)显著下降,且观察组和对照组相比,差异有统计学意义。2组治疗期间均未发生不良反应及肝肾功能异常。结论 健脾消积颗粒能够明显改善脾胃湿热型功能性消化不良患儿临床症状,改善胃动力水平,调节脑肠肽分泌水平。  相似文献   
6.
7.
Plasma provided by COVID-19 convalescent patients may provide therapeutic relief as the number of COVID-19 cases escalates steeply worldwide. Prior findings in various viral respiratory diseases including SARS-CoV-related pneumonia suggest that convalescent plasma can reduce mortality, although formal proof of efficacy is still lacking. By reducing viral spread early on, such an approach may possibly downplay subsequent immunopathology. Identifying, collecting, qualifying and preparing plasma from convalescent patients with adequate SARS-CoV-2-neutralizing Ab titres in an acute crisis setting may be challenging, although well within the remit of most blood establishments. Careful clinical evaluation should allow to quickly establish whether such passive immunotherapy, administered at early phases of the disease in patients at high risk of deleterious evolution, may reduce the frequency of patient deterioration, and thereby COVID-19 mortality.  相似文献   
8.
9.
10.
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