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   1741篇
  免费   90篇
  国内免费   4篇
耳鼻咽喉   9篇
儿科学   44篇
妇产科学   45篇
基础医学   200篇
口腔科学   44篇
临床医学   224篇
内科学   401篇
皮肤病学   21篇
神经病学   161篇
特种医学   40篇
外科学   307篇
综合类   3篇
预防医学   57篇
眼科学   35篇
药学   92篇
中国医学   3篇
肿瘤学   149篇
  2023年   11篇
  2022年   15篇
  2021年   52篇
  2020年   32篇
  2019年   46篇
  2018年   55篇
  2017年   36篇
  2016年   64篇
  2015年   56篇
  2014年   77篇
  2013年   80篇
  2012年   145篇
  2011年   131篇
  2010年   68篇
  2009年   68篇
  2008年   88篇
  2007年   104篇
  2006年   79篇
  2005年   110篇
  2004年   95篇
  2003年   88篇
  2002年   80篇
  2001年   16篇
  2000年   26篇
  1999年   22篇
  1998年   15篇
  1997年   11篇
  1996年   14篇
  1995年   9篇
  1994年   6篇
  1993年   5篇
  1992年   11篇
  1991年   8篇
  1990年   7篇
  1989年   9篇
  1988年   11篇
  1987年   13篇
  1986年   13篇
  1985年   8篇
  1984年   5篇
  1983年   11篇
  1982年   3篇
  1981年   3篇
  1980年   3篇
  1979年   4篇
  1978年   2篇
  1977年   3篇
  1975年   6篇
  1967年   2篇
  1882年   1篇
排序方式: 共有1835条查询结果,搜索用时 15 毫秒
41.
Inflammatory bowel disease consists of Crohn's disease (CD) and ulcerative colitis (UC). A major clinical problem in some patients is to differentiate clearly between these entities, which is important when planning appropriate medical and surgical treatment. Connective tissue growth factor (CTGF), a novel peptide involved in fibrotic disorders, was analyzed in the present study in CD and UC patients to evaluate its possible role in these two disorders. Twenty-five normal human intestinal tissue samples were obtained through an organ donor program. CD tissues were obtained from 28 individuals undergoing partial intestinal resection (17 small bowel; 11 large bowel) due to complications of the disease. UC tissue samples were obtained from 16 patients undergoing colectomy due to complications of the disease. Expression of CTGF was studied by Northern blot analysis. In situ hybridization was used to localize mRNA moieties in the tissue samples. Northern blot analysis revealed an average 5-fold increase in CTGF mRNA expression in 89% (25/28) of CD tissue samples by comparison with normal controls (p < 0.0001). In contrast, in UC samples CTGF mRNA levels were comparable to those of normal controls. However, UC tissue samples exhibited enhanced TGF-beta1 mRNA levels (4-fold; p < 0.05). In situ hybridization in CD samples showed CTGF mRNA localized especially in fibroblasts within the submucosal layer, around lymph follicles and in some areas of intense damage in the proximity of the luminal surface, whereas inflammatory cells were devoid of any CTGF mRNA signal. The present data indicate that CTGF plays a different role in IBD and might be useful, especially in those cases with unusual disease presentation, to better differentiate UC and CD. In addition, our data indicate a crucial role for CTGF in CD, where fibrosis and stenosis are frequent complications that require surgery.  相似文献   
42.
43.
Introduction: Pain is commonly experienced by patients with cancer, particularly those with advanced disease. Alleviating pain is an important goal of cancer treatment. Opioids are the cornerstone of the analgesic treatment.

Areas covered: Pharmacology, characteristics, and use of opioids in clinical practice are presented.

Expert opinion: Although the use of opioids is largely accepted as a fundamental step for controlling cancer pain, existing data supporting this statement are poor. All opioids provide analgesia and are effective in controlling cancer pain. New drugs have been developed and experience is accumulating among clinicians. Despite these drugs having different pharmacokinetic and chemical properties, there is no proof that one opioid is better than another one. Thus, the optimum benefit depends on the experience of the users. Clinicians should weight evidence, clinical experience, patient preferences, and treatment costs when choosing the optimal treatment for an individual patient with cancer pain. New opioids with specific receptor activities are under investigation.  相似文献   

44.

Introduction and objectives

The PARIS score allows combined stratification of ischemic and hemorrhagic risk in patients with ischemic heart disease treated with coronary stenting and dual antiplatelet therapy (DAPT). Its usefulness in patients with acute coronary syndrome (ACS) treated with ticagrelor or prasugrel is unknown. We investigated this issue in an international registry.

Methods

Retrospective multicenter study with voluntary participation of 11 centers in 6 European countries. We studied 4310 patients with ACS discharged with DAPT with ticagrelor or prasugrel. Ischemic events were defined as stent thrombosis or spontaneous myocardial infarction, and hemorrhagic events as BARC (Bleeding Academic Research Consortium) type 3 or 5 bleeding. Discrimination and calibration were calculated for both PARIS scores (PARISischemic and PARIShemorrhagic). The ischemic-hemorrhagic net benefit was obtained by the difference between the predicted probabilities of ischemic and bleeding events.

Results

During a period of 17.2 ± 8.3 months, there were 80 ischemic events (1.9% per year) and 66 bleeding events (1.6% per year). PARISischemic and PARIShemorrhagic scores were associated with a risk of ischemic events (sHR, 1.27; 95%CI, 1.16-1.39) and bleeding events (sHR, 1.14; 95%CI, 1.01-1.30), respectively. The discrimination for ischemic events was modest (C index = 0.64) and was suboptimal for hemorrhagic events (C index = 0.56), whereas calibration was acceptable for both. The ischemic-hemorrhagic net benefit was negative (more hemorrhagic events) in patients at high hemorrhagic risk, and was positive (more ischemic events) in patients at high ischemic risk.

Conclusions

In patients with ACS treated with DAPT with ticagrelor or prasugrel, the PARIS model helps to properly evaluate the ischemic-hemorrhagic risk.  相似文献   
45.
46.
Bucello  Sebastiano  Annovazzi  Pietro  Ragonese  Paolo  Altieri  Marta  Barcella  Valeria  Bergamaschi  Roberto  Bianchi  Alessia  Borriello  Giovanna  Buscarinu  Maria Chiara  Callari  Graziella  Capobianco  Marco  Capone  Fioravante  Cavalla  Paola  Cavarretta  Rosella  Cortese  Antonio  De Luca  Giovanna  Di Filippo  Massimiliano  Dattola  Vincenzo  Fantozzi  Roberta  Ferraro  Elisabetta  Filippi  Maria Maddalena  Gasperini  Claudio  Grimaldi  Luigi Maria Edoardo  Landi  Doriana  Re  Marianna Lo  Mallucci  Giulia  Manganotti  Paolo  Marfia  Girolama Alessandra  Mirabella  Massimiliano  Perini  Paola  Pisa  Marco  Realmuto  Sabrina  Russo  Margherita  Tomassini  Valentina  Torri-Clerici  Valentina Liliana Adriana  Zaffaroni  Mauro  Zuliani  Cristina  Zywicki  Sofia  Filippi  Massimo  Prosperini  Luca 《Journal of neurology》2021,268(8):2922-2932
Journal of Neurology - To identify baseline factors associated with disease activity in patients with relapsing–remitting multiple sclerosis (RRMS) under teriflunomide treatment. This was an...  相似文献   
47.
International Journal of Mental Health and Addiction - Although the existence of dysfunctional love relationships is well known and the term “love addiction” dates back to the 1970s,...  相似文献   
48.
BackgroundThe health impact of antimicrobial resistance (AMR) has not been included in the Global Burden of Disease (GBD) report, as reliable data have been lacking. AMR burden estimates have been derived from models combining incidence and/or prevalence data from national and/or international surveillance systems and mortality estimates from clinical studies. Depending on utilized empirical data, statistical methodology and applied endpoints, the validity and reliability of results can differ substantially.ObjectivesWe assessed comprehensiveness, and internal and external validity of studies estimating the clinical impact of infections caused by the priority antibiotic resistant pathogens monitored by the WHO Global Antimicrobial Resistance Surveillance System.Data sourcesOvid MEDLINE, January 1950 to March 2019, In-Process and other non-indexed citations were searched.Study eligibility criteriaStudies reporting mortality, length of hospital stay, duration of the disease until remission and/or death, complications, hospital re-admissions, and follow-up beyond hospital discharge were eligible.MethodsThe literature was searched according to the Cochrane recommendations and reported according to Preferred Reporting Items for Systematic Reviews.ResultsTwo-hundred and eighty-six studies out of 3529 were eligible. Studies derived mainly from high-income countries (215, 75%) and relied on data from retrospective (226, 79%), single-centre (201, 70%), cohort studies (243, 85%). The health impact was mostly limited to all-cause mortality (128, 45%) with heterogeneity in timing of assessment; attributable length of hospital stay was seldom adjusted for pre-infection admission time and a few studies had enough follow-up for assessing long-term sequelae. Overall, adjustment for confounding has shown a substantial improvement. Data on health state definitions and duration of diseases are generally lacking, precluding calculation of disability-adjusted life years, critical for application of the GBD study methodology.ConclusionEfforts to improve harmonization, representativeness, quality of AMR surveillance data and cohort studies to determine AMR attributable mortality and morbidity are urgently required. Policy makers need accurate and detailed burden estimates to inform prioritization of resource allocation, and to select the most effective intervention strategies to halt the AMR crisis.  相似文献   
49.
Kohlschütter–Tönz syndrome (KTS) is a rare autosomal recessive disorder characterized by amelogenesis imperfecta, psychomotor delay or regression and seizures starting early in childhood. KTS was established as a distinct clinical entity after the first report by Kohlschütter in 1974, and to date, only a total of 20 pedigrees have been reported. The genetic etiology of KTS remained elusive until recently when mutations in ROGDI were independently identified in three unrelated families and in five likely related Druze families. Herein, we report a clinical and genetic study of 10 KTS families. By using a combination of whole exome sequencing, linkage analysis, and Sanger sequencing, we identify novel homozygous or compound heterozygous ROGDI mutations in five families, all presenting with a typical KTS phenotype. The other families, mostly presenting with additional atypical features, were negative for ROGDI mutations, suggesting genetic heterogeneity of atypical forms of the disease.  相似文献   
50.
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