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   8231篇
  免费   1015篇
  国内免费   190篇
耳鼻咽喉   69篇
儿科学   183篇
妇产科学   112篇
基础医学   834篇
口腔科学   284篇
临床医学   1332篇
内科学   1463篇
皮肤病学   160篇
神经病学   636篇
特种医学   471篇
外国民族医学   1篇
外科学   740篇
综合类   989篇
预防医学   799篇
眼科学   200篇
药学   353篇
  20篇
中国医学   253篇
肿瘤学   537篇
  2024年   12篇
  2023年   223篇
  2022年   267篇
  2021年   523篇
  2020年   524篇
  2019年   457篇
  2018年   394篇
  2017年   415篇
  2016年   399篇
  2015年   381篇
  2014年   573篇
  2013年   583篇
  2012年   423篇
  2011年   451篇
  2010年   356篇
  2009年   356篇
  2008年   314篇
  2007年   315篇
  2006年   282篇
  2005年   248篇
  2004年   216篇
  2003年   196篇
  2002年   181篇
  2001年   195篇
  2000年   133篇
  1999年   88篇
  1998年   108篇
  1997年   107篇
  1996年   62篇
  1995年   78篇
  1994年   61篇
  1993年   55篇
  1992年   57篇
  1991年   33篇
  1990年   42篇
  1989年   36篇
  1988年   51篇
  1987年   30篇
  1986年   34篇
  1985年   33篇
  1984年   20篇
  1983年   17篇
  1982年   16篇
  1981年   12篇
  1980年   17篇
  1978年   7篇
  1977年   8篇
  1976年   12篇
  1975年   8篇
  1974年   14篇
排序方式: 共有9436条查询结果,搜索用时 31 毫秒
1.
目的:探讨消化道肿瘤中同源重组修复相关基因(homologous recombination repair related gene,HRR)突变的发生情况及临床意义。方法:共92例消化道肿瘤患者,79例患者进行了血液标本HRR检测,53例患者进行了组织标本HRR检测,40例患者同时行血液和组织的HRR基因检测,收集患者基因检测结果及临床相关资料。结果:在79例患者血液标本检测中发现10例(12.6%)有临床意义HRR突变,在53例患者组织标本检测中发现9例(17.0%)有临床意义HRR突变。40例同时行血液和组织的HRR基因检测患者中常见的有临床意义HRR突变为CDK12突变4例(10.0%)、ATM突变3例(7.5%)、BRCA1突变2例(5.0%)。13例有临床意义HRR突变患者中常见共存突变为TP53突变10例(76.9%)、APC突变5例(38.5%)、PIK3CA突变4例(30.8%)。40例患者中13例患者血液和/或组织中有临床意义HRR突变,27例患者血液和组织中均无任何临床意义HRR突变且两组相比,有临床意义HRR突变组肿瘤突变负荷(tumor mutational burden,TMB)为6.17(2.24~11.52),而未携带HRR突变组TMB为0.4(0~3.75),差异有统计学意义(P<0.05)。40例患者组织检测中7例HRR有临床意义的突变,33例无HRR突变,血液检测中10例HRR有临床意义的突变,30例无HRR突变,一致性检验的Kappa值为0.333(P=0.031)。结论:携带有临床意义HRR突变的消化道肿瘤患者TMB更高,血液和组织检测HRR突变有较好的一致性。  相似文献   
2.
3.
4.

Background

Purulent bacterial pericarditis is a rare and potentially fatal disease. The course may be fulminant, and the presentation may pose a diagnostic challenge.

Case report

An otherwise healthy 75-year-old male was brought to the emergency department in a state of general deterioration, confusion, and shock. Bedside ultrasound showed a significant pericardial effusion. His condition quickly deteriorated and the resuscitation included emergent bedside pericardiocentesis. The drainage was purulent and later cultures grew out Streptococcus pneumoniae.

Why should an emergency physician be aware of this?

Purulent pericarditis is extremely rare but should be considered in the patient with a fulminant infectious process (particularly pneumonia) and signs of pericardial effusion. Treatment should include appropriate antibiotics and early drainage.  相似文献   
5.
6.
胡山  赵波 《中国临床医学》2020,27(3):899-900
面对来势汹汹的新型冠状病毒肺炎(COVID-19),如何能够正确、快速诊断和筛检出确诊病例显得尤为重要,国内诸多科技工作者都在积极开展相关的诊断试验研究。本文回顾了目前正在开展的十余项诊断试验的注册信息,针对其中存在的共性问题进行了讨论,重点阐述了如何使用PICOS原则构造COVID-19诊断试验的研究问题,还对金标准的设置、受试者的代表性、样本量计算和同步、独立、盲法的测定等诊断试验的设计要点进行了详细说明。旨在为广大研究者提供开展COVID-19诊断试验的设计建议,帮助研究者在顶层设计阶段减少、避免偏倚,完成高质量的临床研究,为临床诊疗提供循证医学证据。  相似文献   
7.
8.
Fibroepithelial polyps (FEPs) are common, benign intraoral lesions that tend to develop slowly at predictable sites, often in response to local irritation or trauma. Historical precedent often results in referral to oral and maxillofacial surgery (OMFS) departments for biopsy, often irrespective of symptoms, and histological assessment. OMFS and pathology services are struggling to cope with an increasing workload that will potentially lead to widespread delays to diagnosis and treatment. Over the past 20 years, clinical pathways and guidance have been developed to ensure that healthcare interventions, such as the removal of third molars, tonsils, skin tags, and benign moles, are evidence-based, have a net patient benefit, and ensure the best use of finite NHS resources. However, no such guidance exists for intraoral lesions and we regard this as an oversight. We analysed the removal of 682 FEPs over a seven-year period and report sensitivities of 92.4% for a “confirmed clinical suspicion of an FEP” and 99.7% for a “confirmed clinical suspicion of a benign diagnosis”. The incidence of non-benign disease was 0.3%. Primary care dentists should be able to diagnose and monitor FEPs and refer only if symptoms are serious or in high-risk patients or sites. Adopting this practice across the UK could free up to 1825 four-hour OMFS clinics, 405 hours of consultant histopathologists’ time, and recurring savings to the NHS estimated to be in the region of £620 000/annum. We believe that the removal of FEPs should be reclassified as an “intervention not normally funded”, and the time and resources put to better use treating patients with lesions of questionable pathology.  相似文献   
9.
《Vaccine》2021,39(34):4759-4765
Dengue vaccination would enhance the control of dengue, one of the most frequent vector-borne viral diseases globally. CYD-TDV is the first dengue vaccine to be licensed, but global uptake has been hampered due to its use being limited to seropositive persons aged 9 years and above, and the need for a 3-dose schedule. The Partnership for Dengue Control (PDC) organized a meeting with key opinion leaders and stakeholders to deliberate on implementation strategies for the use of CYD-TDV. New data have emerged that support the shortening of the primary schedule from a 3 to 2 dose schedule, extending the age range below 9 to 6 years of age, and expanding the indication from endemic populations to also include travelers to endemic areas. Cost-effectiveness may improve with the modified 2-dose regimen and with multiple testing. Strategies to implement a dengue vaccination program have been developed, in particular school-based strategies. A range of delivery scenarios can then be considered, using various settings for each step of the intervention. However, several challenges remain, including communication about limiting the use of this vaccine to seropositive individuals only. Affordability will vary from country to country, as will government commitment and community acceptance. Well-tailored communication strategies that target key stakeholders are expected to make up a significant part of any future dengue vaccination program.  相似文献   
10.
Mutations in SH2D1A, encoding the intracellular adaptor signaling lymphocyte activation molecule associated protein (SAP), are associated with X‐linked lymphoproliferative disease type 1 (XLP1). We identified a novel hemizygous SH2D1A c.49G > A (p.E17K) variant in a 21‐year‐old patient with fatal Epstein‐Barr virus infection–associated hemophagocytic lymphohistiocytosis. Cellular and biochemical assays revealed normal expression of the SAP variant protein, yet binding to phosphorylated CD244 receptor was reduced by >95%. Three healthy brothers carried the SH2D1A c.49G > A variant. Thus, data suggest that this variant represents a pathogenic mutation, but with variable expressivity. Importantly, our results highlight challenges in the clinical interpretation of SH2D1A variants and caution in using functional flow cytometry assays for the diagnosis of XLP1.  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