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   533297篇
  免费   25030篇
  国内免费   480篇
耳鼻咽喉   6696篇
儿科学   16949篇
妇产科学   12537篇
基础医学   92670篇
口腔科学   12369篇
临床医学   48561篇
内科学   95622篇
皮肤病学   11877篇
神经病学   34094篇
特种医学   19766篇
外国民族医学   53篇
外科学   78112篇
综合类   7612篇
现状与发展   2篇
一般理论   107篇
预防医学   38547篇
眼科学   11957篇
药学   41435篇
  11篇
中国医学   1126篇
肿瘤学   28704篇
  2019年   3982篇
  2018年   5745篇
  2017年   4137篇
  2016年   4883篇
  2015年   5365篇
  2014年   7117篇
  2013年   10499篇
  2012年   15575篇
  2011年   17393篇
  2010年   9955篇
  2009年   8824篇
  2008年   15712篇
  2007年   17445篇
  2006年   16940篇
  2005年   16265篇
  2004年   15883篇
  2003年   15265篇
  2002年   14790篇
  2001年   22430篇
  2000年   22970篇
  1999年   18919篇
  1998年   5232篇
  1997年   4364篇
  1996年   4397篇
  1995年   4124篇
  1992年   14413篇
  1991年   15817篇
  1990年   15949篇
  1989年   15625篇
  1988年   14308篇
  1987年   14198篇
  1986年   13168篇
  1985年   12686篇
  1984年   9394篇
  1983年   8000篇
  1982年   4177篇
  1979年   8937篇
  1978年   6382篇
  1977年   5149篇
  1976年   5504篇
  1975年   6613篇
  1974年   7419篇
  1973年   7158篇
  1972年   6597篇
  1971年   6309篇
  1970年   5887篇
  1969年   5467篇
  1968年   5161篇
  1967年   4621篇
  1966年   3963篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
51.
52.
BackgroundMicrobial whole genome sequencing (WGS) has many advantages over standard microbiological methods. However, it is not yet widely implemented in routine hospital diagnostics due to notable challenges.ObjectivesThe aim was to extract managerial, financial and clinical criteria supporting the decision to implement WGS in routine diagnostic microbiology, across different operational models of implementation in the hospital setting.MethodsThis was a systematic review of literature identified through PubMed and Web of Science. English literature studies discussing the applications of microbial WGS without limitation on publication date were eligible. A narrative approach for categorization and synthesis of the sources identified was adopted.ResultsA total of 98 sources were included. Four main alternative operational models for incorporating WGS in clinical microbiology laboratories were identified: full in-house sequencing and analysis, full outsourcing of sequencing and analysis and two hybrid models combining in-house/outsourcing of the sequencing and analysis components. Six main criteria (and multiple related sub-criteria) for WGS implementation emerged from our review and included cost (e.g. the availability of resources for capital and operational investment); manpower (e.g. the ability to provide training programmes or recruit trained personnel), laboratory infrastructure (e.g. the availability of supplies and consumables or sequencing platforms), bioinformatics requirements (e.g. the availability of valid analysis tools); computational infrastructure (e.g. the availability of storage space or data safety arrangements); and quality control (e.g. the existence of standardized procedures).ConclusionsThe decision to incorporate WGS in routine diagnostics involves multiple, sometimes competing, criteria and sub-criteria. Mapping these criteria systematically is an essential stage in developing policies for adoption of this technology, e.g. using a multicriteria decision tool. Future research that will prioritize criteria and sub-criteria that were identified in our review in the context of operational models will inform decision-making at clinical and managerial levels with respect to effective implementation of WGS for routine use. Beyond WGS, similar decision-making challenges are expected with respect to future integration of clinical metagenomics.  相似文献   
53.
54.
ObjectivesHigh-quality diagnosis of bloodstream infections (BSI) is important for successful patient management. As knowledge on current practices of microbiological BSI diagnostics is limited, this project aimed to assess its current state in European microbiological laboratories.MethodsWe performed an online questionnaire-based cross-sectional survey comprising 34 questions on practices of microbiological BSI diagnostics. The ESCMID Study Group for Bloodstream Infections, Endocarditis and Sepsis (ESGBIES) was the primary platform to engage national coordinators who recruited laboratories within their countries.ResultsResponses were received from 209 laboratories in 25 European countries. Although 32.5% (68/209) of laboratories only used the classical processing of positive blood cultures (BC), two-thirds applied rapid technologies. Of laboratories that provided data, 42.2% (78/185) were able to start incubating BC in automated BC incubators around-the-clock, and only 13% (25/192) had established a 24-h service to start immediate processing of positive BC. Only 4.7% (9/190) of laboratories validated and transmitted the results of identification and antimicrobial susceptibility testing (AST) of BC pathogens to clinicians 24 h/day. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry from briefly incubated sub-cultures on solid media was the most commonly used approach to rapid pathogen identification from positive BC, and direct disc diffusion was the most common rapid AST method from positive BC.ConclusionsLaboratories have started to implement novel technologies for rapid identification and AST for positive BC. However, progress is severely compromised by limited operating hours such that current practice of BC diagnostics in Europe complies only partly with the requirements for optimal BSI management.  相似文献   
55.
56.
On August 30, 2017 the US Food and Drug Administration approved tisagenlecleucel (Kymriah; Novartis, Basel, Switzerland), a synthetic bioimmune product of anti-CD19 chimeric antigen receptor T cells (CAR-T), for the treatment of children and young adults with relapsed/refractory B cell acute lymphoblastic leukemia (B-ALL). With this new era of personalized cancer immunotherapy, multiple challenges are present, ranging from implementation of a CAR-T program to safe delivery of the drug, long-term toxicity monitoring, and disease assessments. To address these issues experts representing the American Society for Blood and Marrow Transplant, the European Society for Blood and Marrow Transplantation, the International Society of Cell and Gene Therapy, and the Foundation for the Accreditation of Cellular Therapy formed a global CAR-T task force to identify and address key questions pertinent for hematologists and transplant physicians regarding the clinical use of anti CD19 CAR-T therapy in patients with B-ALL. This article presents an initial roadmap for navigating common clinical practice scenarios that will become more prevalent now that the first commercially available CAR-T product for B-ALL has been approved.  相似文献   
57.
Purpose

Intermittent hypoxia training/treatment (IHT) is an emerging therapeutic approach to alleviate chronic diseases, such as diabetes. The present study investigated the effects of IHT on blood leucocyte pyruvate dehydrogenase kinase 1 (PDK-1) mRNA expression and its relationship with the changes in blood insulin level.

Methods

Seven adult healthy volunteers and 11 prediabetic patients participated in this study. A 3-week course of IHT consisted of a 40-min session of 4 cycles of 5-min 12% O2 and 5-min room air breathing per day, 3 sessions per week for 3 weeks (i.e., total 9 sessions of IHT). Plasma insulin levels and leukocyte PDK-1 mRNA expression were determined at various time points either under fasting condition or following oral glucose tolerance test (OGTT). Correlation between the IHT-induced changes in PDK-1 mRNA and insulin or glucose levels in the same serological samples was analyzed.

Results

At pre-IHT baseline, PDK-1 mRNA expression was two times higher in prediabetes than control subjects. IHT resulted in significant augmentation in PDK-1 mRNA expression (> twofold) in prediabetes at the end of 3-week IHT and remained elevated 1 month after IHT, which was correlated with a significantly reduced insulin release and lower blood glucose after glucose loading with OGTT.

Conclusion

IHT can trigger beneficial effects in normalizing blood insulin levels in prediabetic patients under oral glucose load, which were closely correlated with an enhanced mRNA expression of PDK-1 in leukocytes. Further clinical trials are warranted to validate the utility of IHT as a non-invasive complementary therapy against diabetes-associated pathologies.

  相似文献   
58.
59.
AimTo investigate clinico-pathological features of lymphoma of the lips, and review the literature.Materials and MethodsRetrospective analysis and review of English literature, 1996-2016.ResultsAnalysis included 23 cases, 7 new cases and 16 from literature, 12 M: 11 F, age 7–82 years. Four occurred in children, mean age 10.1; 19 in adults, mean 61.1 years.The lower lip was involved in the majority of cases (16, 69.56%). 14 (60.87%) were isolated to the lips, 8 (34.78%) were multifocal. Nine (39.13%) occurred in association with Sjogren's syndrome, of which one also had Hashimoto thyroiditis. IgG4-related disease and HIV were reported in one case each. The lip salivary glands were involved in most cases (19, 82.6%); 3 (13.6%) showed only cutaneous involvement.The typical presentation was single or multiple nodules (15, 65.21%), with surface ulceration in only two (8.69%). Constituent symptoms were absent in all cases, paresthesia was reported in one (4.34%). The majority (18, 78.26%) was extranodal marginal zone B-cell lymphoma - mucosa-associated lymphoid tissue lymphoma (EMZB-MALT), and one case each was mantle cell, NK-T cell, CD30 positive and plasmablastic lymphoma.ConclusionThe lips seem to have a unique pattern of non-Hodgkin lymphoma dominated by EMZB-MALT lymphoma, rarely other types. In more than half, neither Sjogren's syndrome nor other chronic inflammation was identified. Lesions tend to present as asymptomatic slowly progressing, non-ulcerated submucosal masses. Lymphoma should be considered even in the absence of constituent symptoms, as most cases showed none. Although the number of reported cases is rather small, disease course is usually prolonged and prognosis seems to be good.  相似文献   
60.
This review presents the first detailed presentation of the parallelism between the Tuskegee Syphilis Study and the Captain America graphic novel ‘TRUTH: Red, White and Black’, published as a graphic novel by Marvel Comics in 2004 as a paperback, and then in 2009 as a hardcover. First written, published and distributed monthly in 2003 as pre-sequel seven comic book series to tell the story of the origins of the WWII superhero Captain America. In 2003, Marvel Comics chose to tell a ‘very dark story’ to explain the origins of Captain America, a half century after the initial introduction of Captain America as a WWII action hero in 1940. By detailing—for the first time—nine parallel aspects between these two storylines, this review demonstrates how Marvel Comics brought the tragic Tuskegee Syphilis Study story into the popular press, thus reaching an audience far beyond traditional bioethics academicians. This review is intended to stimulate and guide classroom discussions on the ethical issues at the core of the infamous Tuskegee Syphilis Study allowing bioethical issues to be made more accessible to the general public, via school curriculums, by the use of graphic novels.  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