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   69206篇
  免费   7385篇
  国内免费   2714篇
耳鼻咽喉   803篇
儿科学   827篇
妇产科学   998篇
基础医学   6891篇
口腔科学   1471篇
临床医学   6725篇
内科学   8805篇
皮肤病学   561篇
神经病学   4740篇
特种医学   2029篇
外国民族医学   1篇
外科学   7632篇
综合类   11809篇
现状与发展   4篇
预防医学   7582篇
眼科学   875篇
药学   6395篇
  81篇
中国医学   2920篇
肿瘤学   8156篇
  2024年   158篇
  2023年   1328篇
  2022年   2329篇
  2021年   3714篇
  2020年   3335篇
  2019年   2608篇
  2018年   2562篇
  2017年   2697篇
  2016年   2695篇
  2015年   2821篇
  2014年   4970篇
  2013年   5016篇
  2012年   4464篇
  2011年   4916篇
  2010年   3770篇
  2009年   3820篇
  2008年   3762篇
  2007年   3714篇
  2006年   3202篇
  2005年   2750篇
  2004年   2215篇
  2003年   1907篇
  2002年   1413篇
  2001年   1319篇
  2000年   1199篇
  1999年   1019篇
  1998年   745篇
  1997年   671篇
  1996年   510篇
  1995年   492篇
  1994年   445篇
  1993年   338篇
  1992年   335篇
  1991年   256篇
  1990年   253篇
  1989年   212篇
  1988年   185篇
  1987年   177篇
  1986年   120篇
  1985年   181篇
  1984年   134篇
  1983年   78篇
  1982年   94篇
  1981年   76篇
  1980年   77篇
  1979年   62篇
  1978年   40篇
  1977年   32篇
  1976年   30篇
  1975年   19篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
1.
We have updated recommendations on 12 controversial topics that were published in the 2013 National Consensus on the diagnosis, risk stratification and treatment of patients with pulmonary embolism (PE). A comprehensive review of the literature was performed for each topic, and each recommendation was evaluated in two teleconferences. For diagnosis, we recommend against using the Pulmonary Embolism Rule Out Criteria (PERC) rule as the only test to rule out PE, and we recommend using a D-dimer cutoff adjusted to age to rule out PE. We suggest using computed tomography pulmonary angiogram as the imaging test of choice for the majority of patients with suspected PE. We recommend using direct oral anticoagulants (over vitamin K antagonists) for the vast majority of patients with acute PE, and we suggest using anticoagulation for patients with isolated subsegmental PE. We recommend against inserting an inferior cava filter for the majority of patients with PE, and we recommend using full-dose systemic thrombolytic therapy for PE patients requiring reperfusion. The decision to stop anticoagulants at 3 months or to treat indefinitely mainly depends on the presence (or absence) and type of risk factor for venous thromboembolism, and we recommend against thrombophilia testing to decide duration of anticoagulation. Finally, we suggest against extensive screening for occult cancer in patients with PE.  相似文献   
2.
In clinical and epidemiological studies, there is a growing interest in studying the heterogeneity among patients based on longitudinal characteristics to identify subtypes of the study population. Compared to clustering a single longitudinal marker, simultaneously clustering multiple longitudinal markers allow additional information to be incorporated into the clustering process, which reveals co-existing longitudinal patterns and generates deeper biological insight. In the current study, we propose a Bayesian consensus clustering (BCC) model for multivariate longitudinal data. Instead of arriving at a single overall clustering, the proposed model allows each marker to follow marker-specific local clustering and these local clusterings are aggregated to find a global (consensus) clustering. To estimate the posterior distribution of model parameters, a Gibbs sampling algorithm is proposed. We apply our proposed model to the primary biliary cirrhosis study to identify patient subtypes that may be associated with their prognosis. We also perform simulation studies to compare the clustering performance between the proposed model and existing models under several scenarios. The results demonstrate that the proposed BCC model serves as a useful tool for clustering multivariate longitudinal data.  相似文献   
3.
Collagens are the most abundant proteins in the extracellular matrix. They provide a framework to build organs and tissues and give structural support to make them resistant to mechanical load and forces. Several intra‐ and extracellular modifications are needed to make functional collagen molecules, intracellular post‐translational modifications of proline and lysine residues having key roles in this. In this article, we provide a review on the enzymes responsible for the proline and lysine modifications, that is collagen prolyl 4‐hydroxylases, 3‐hydroxylases and lysyl hydroxylases, and discuss their biological functions and involvement in diseases.  相似文献   
4.
Acute Coma     
《Neurologic Clinics》2021,39(2):257-272
  相似文献   
5.
深化家庭医生签约服务是深化医药卫生体制改革、强化基层医疗卫生服务、实现"健康中国"战略目标的重要选择,也是当前更好维护人民群众健康的重要途径。为有效推进签约服务工作,国家陆续推出各项政策,全国各地也在积极进行实践探索,成效明显。但是,签约服务仍面临诸多问题,其中"执行难"是签约服务深度推进的一大困境。通过史密斯政策执行过程模型,结合签约服务政策执行过程,发现签约服务仍存在法治性不足、政策执行人员水平不高、激励不足、政策环境影响等诸多制约因素。因此,需要从法律和制度方面进行顶层设计、提升执行人员素质和职业认同、建立医患互信、优化政策执行环境等角度进行政策创新,探索家庭医生签约服务可持续发展的路径。  相似文献   
6.
《Molecular therapy》2022,30(8):2856-2867
  1. Download : Download high-res image (173KB)
  2. Download : Download full-size image
  相似文献   
7.
8.
9.
《Value in health》2022,25(6):1010-1017
ObjectivesSurvival extrapolation for chimeric antigen receptor T-cell therapies is challenging, owing to their unique mechanistic properties that translate to complex hazard functions. Axicabtagene ciloleucel is indicated for the treatment of relapse or refractory diffuse large B-cell lymphoma after 2 or more lines of therapy based on the ZUMA-1 trial. Four data snapshots are available, with minimum follow-up of 12, 24, 36, and 48 months. This analysis explores how survival extrapolations for axicabtagene ciloleucel using ZUMA-1 data can be validated and compared.MethodsThree different parametric modeling approaches were applied: standard parametric, spline-based, and cure-based models. Models were compared using a range of metrics, across the 4 data snapshot, including visual fit, plausibility of long-term estimates, statistical goodness of fit, inspection of hazard plots, point-estimate accuracy, and conditional survival estimates.ResultsStandard and spline-based parametric extrapolations were generally incapable of fitting the ZUMA-1 data well. Cure-based models provided the best fit based on the earliest data snapshot, with extrapolations remaining consistent as data matured. At 48 months, the maximum survival overestimate was 8.3% (Gompertz mixture-cure model) versus the maximum underestimate of 33.5% (Weibull standard parametric model).ConclusionsWhere a plateau in the survival curve is clinically plausible, cure-based models may be helpful in making accurate predictions based on immature data. The ability to reliably extrapolate from maturing data may reduce delays in patient access to potentially lifesaving treatments. Additional research is required to understand how models compare in broader contexts, including different treatments and therapeutic areas.  相似文献   
10.
目的 建立苏州市肺结核发病的SARIMA模型并预测发病,为苏州市肺结核防控提供参考。方法 收集结核病信息管理系统(新)中苏州市2010年1月—2018年12月肺结核月发病数,通过时间序列分析建立SARIMA模型并预测苏州市2019年肺结核的发病情况。结果 苏州市肺结核发病数具有明显的季节周期性,每年的发病最高峰为5月,发病最低谷为2月。苏州市肺结核发病数的最佳拟合模型为SARIMA (0,1,1)×(0,1,1)12,AIC=9.590,SBC=9.644,模型参数均具有统计学意义,模型残差为白噪声序列,模型的预测值与实际值平均绝对百分比误差MAPE=7.943%,模型预测精度较高。预测苏州市2019年肺结核发病数为3 467例,月发病数平均值为289例,发病水平较2018年略有下降。结论 SARIMA(0,1,1)×(0,1,1)12模型能较好拟合出苏州市肺结核发病数的时间变化趋势,可应用于苏州市肺结核月发病数的短期预测。  相似文献   
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