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   250050篇
  免费   12342篇
  国内免费   431篇
耳鼻咽喉   3334篇
儿科学   7920篇
妇产科学   5253篇
基础医学   35567篇
口腔科学   6029篇
临床医学   19699篇
内科学   54480篇
皮肤病学   6548篇
神经病学   22216篇
特种医学   7777篇
外国民族医学   101篇
外科学   31783篇
综合类   1110篇
一般理论   66篇
预防医学   22849篇
眼科学   4972篇
药学   17579篇
中国医学   751篇
肿瘤学   14789篇
  2023年   1344篇
  2022年   914篇
  2021年   3698篇
  2020年   2252篇
  2019年   4106篇
  2018年   7771篇
  2017年   5186篇
  2016年   5262篇
  2015年   5866篇
  2014年   6140篇
  2013年   9842篇
  2012年   16761篇
  2011年   16816篇
  2010年   8464篇
  2009年   6384篇
  2008年   14310篇
  2007年   15404篇
  2006年   14197篇
  2005年   14096篇
  2004年   13260篇
  2003年   12191篇
  2002年   11472篇
  2001年   6604篇
  2000年   6687篇
  1999年   5950篇
  1998年   1069篇
  1997年   885篇
  1996年   841篇
  1992年   3471篇
  1991年   3108篇
  1990年   2977篇
  1989年   2737篇
  1988年   2609篇
  1987年   2405篇
  1986年   2310篇
  1985年   2124篇
  1984年   1583篇
  1983年   1347篇
  1982年   771篇
  1979年   1390篇
  1978年   972篇
  1977年   905篇
  1975年   921篇
  1974年   1132篇
  1973年   1139篇
  1972年   1087篇
  1971年   1038篇
  1970年   963篇
  1969年   1042篇
  1968年   905篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
62.
63.
64.

Background

Spontaneous decolonization of antibiotic-resistant bacteria (ARB) takes time: approximately 25% after 30 days for carbapenem-producing Enterobacteriaceae or extended-spectrum beta-lactamase-producing Enterobacteriaceae. Faecal microbiota transplantation (FMT) has been proposed as a new strategy to promote decolonization in order to reduce the risk of superinfection due to these ARB. This paper discusses the literature on the use of FMT for this indication, and the improvement levers available to promote its efficacy.

Methods

Literature available to date concerning the use of FMT to eradicate ARB was reviewed, and the different factors that may have influenced the efficacy of decolonization were evaluated.

Results

Four axes that could have played major roles in the efficacy of FMT were identified: bowel preparation before FMT; donor; dose; and thermal conditioning of faeces. The positive or negative impact of each on the outcome of FMT is discussed.

Conclusion

Although FMT is very efficient for the eradication of Clostridium difficile, the same ‘recipe’ cannot be used for the eradication of ARB. Working together with expert centres may help to improve the efficacy of FMT for this indication, and enable the reduction of in-hospital isolation precautions.  相似文献   
65.

Background

The ZOE-50 (NCT01165177) and ZOE-70 (NCT01165229) phase 3 clinical trials showed that the adjuvanted recombinant zoster vaccine (RZV) was ≥90% efficacious in preventing herpes zoster in adults. Here we present a comprehensive overview of the safety data from these studies.

Methods

Adults aged ≥50 (ZOE-50) and ≥70 (ZOE-70) years were randomly vaccinated with RZV or placebo. Safety analyses were performed on the pooled total vaccinated cohort, consisting of participants receiving at least one dose of RZV or placebo. Solicited and unsolicited adverse events (AEs) were collected for 7 and 30?days after each vaccination, respectively. Serious AEs (SAEs) were collected from the first vaccination until 12?months post-last dose. Fatal AEs, vaccination-related SAEs, and potential immune-mediated diseases (pIMDs) were collected during the entire study period.

Results

Safety was evaluated in 14,645 RZV and 14,660 placebo recipients. More RZV than placebo recipients reported unsolicited AEs (50.5% versus 32.0%); the difference was driven by transient injection site and solicited systemic reactions that were generally seen in the first week post-vaccination. The occurrence of overall SAEs (RZV: 10.1%; Placebo: 10.4%), fatal AEs (RZV: 4.3%; Placebo: 4.6%), and pIMDs (RZV: 1.2%; Placebo: 1.4%) was balanced between groups. The occurrence of possible exacerbations of pIMDs was rare and similar between groups. Overall, except for the expected local and systemic symptoms, the safety results were comparable between the RZV and Placebo groups irrespective of participant age, gender, or race.

Conclusions

No safety concerns arose, supporting the favorable benefit-risk profile of RZV.  相似文献   
66.

Background

Influenza viruses (FLUV) are continuously evolving, which explain the occurrence of seasonal influenza epidemics and the need to review the vaccine strain composition annually. The aim is to describe the genetic diversity and clinical outcomes of FLUV detected at a tertiary university hospital in Barcelona (Spain) during the 2012–2016 seasons.

Methods

The detection of FLUV from patients attended at the Emergency Department or admitted to the hospital was performed by either immunofluorescence or PCR-based assays. A specific real-time one-step multiplex RT-PCR was performed for influenza A (FLUAV) subtyping. The complete coding haemagglutinin domain 1 (HA1) and neuraminidase (NA) (2015–2016) protein sequences from a representative sampling were molecular characterised.

Results

A total 1774 (66.1%) FLUAV and 910 (33.9%) influenza B (FLUBV) cases were laboratory-confirmed. The hospitalisation rate was different between seasons, being the highest (81.4%) during the 2014–2015 season. FLUV were genetically close to vaccine strains except to the 2014–2015, in which most characterised A(H3N2) viruses belonged to a genetic group different from the vaccine strain. During the 2015–2016 season, B/Victoria-like viruses were the most predominant, but this component was not included in the trivalent vaccine used. Mutations D222G or D222N in HA1-domain were found in 3 A(H1N1)pdm09 strains from ICU-admitted cases. Three A(H1N1)pdm09 strains carried the NA H275Y (2) and S247N (1) mutations, respectively related to resistance or decreased susceptibility to oseltamivir.

Conclusions

The circulation of drifted A(H3N2) strains during the 2014–2015 season was related to the high hospitalisation rate due to the mismatch with the vaccine strains. The predominance of a FLUBV lineage not included in the trivalent influenza vaccine during the 2015–2016 season highlights the need to use a tetravalent influenza vaccine. Virological surveillance of viral variants carrying protein changes that alter tropism and susceptibility to antivirals features should be strengthened in hospital settings.  相似文献   
67.
The efforts for the development and testing of vaccines against Trypanosoma cruzi infection have increased during the past years. We have designed a TcVac series of vaccines composed of T. cruzi derived, GPI-anchored membrane antigens. The TcVac vaccines have been shown to elicit humoral and cellular mediated immune responses and provide significant (but not complete) control of experimental infection in mice and dogs. Herein, we aimed to test two immunization protocols for the delivery of DNA-prime/DNA-boost vaccine (TcVac1) composed of TcG2 and TcG4 antigens in a BALB/c mouse model. Mice were immunized with TcVac1 through intradermal/electroporation (IDE) or intramuscular (IM) routes, challenged with T. cruzi, and evaluated during acute phase of infection. The humoral immune response was evaluated through the assessment of anti-TcG2 and anti-TcG4 IgG subtypes by using an ELISA. Cellular immune response was assessed through a lymphocyte proliferation assay. Finally, clinical and morphopathological aspects were evaluated for all experimental animals. Our results demonstrated that when comparing TcVac1 IDE delivery vs IM delivery, the former induced significantly higher level of antigen-specific antibody response (IgG2a?+?IgG2b?>?IgG1) and lymphocyte proliferation, which expanded in response to challenge infection. Histological evaluation after challenge infection showed infiltration of inflammatory cells (macrophages and lymphocytes) in the heart and skeletal tissue of all infected mice. However, the largest increase in inflammatory infiltrate was observed in TcVac1_IDE/Tc mice when compared with TcVac1_IM/Tc or non-vaccinated/infected mice. The extent of tissue inflammatory infiltrate was directly associated with the control of tissue amastigote nests in vaccinated/infected (vs. non-vaccinated/infected) mice. Our results suggest that IDE delivery improves the protective efficacy of TcVac1 vaccine against T. cruzi infection in mice when compared with IM delivery of the vaccine.  相似文献   
68.
69.
Introduction and objectivesChronic kidney disease has a high prevalence and economic impact, and an increased risk of hospitalization. Although there are public regional and country registries, we have not found references to estimate the impact of renal replacement therapy (RRT) on hospital admissions.MethodsWe obtained authorization from the ethics committee and health authorities to integrate the REMER [Madrid Kidney Disease Registry] (2013-2014) and Minimum Basic Data Set (2013-2015) databases and to analyze the admissions during the first year of RRT.Results767 patients started RRT in all the hospitals of our region across all RRT modalities. More than a third of the patients start dialysis during a hospital admission. This unplanned start, more common in HD than PD, shows relevant differences in patient profile or admission characteristics.Without considering this initial episode, almost 60% of patients were admitted during their first year. The hospitalization rate was 1.2 admissions/patient, higher in HD than in TX or PD; the mean length of stay was 8.6 days.The estimated cost of admissions during the first year is €12,006/patient. Our analysis ensures the exhaustive inclusion of all episodes and accurate estimation based on the discharge form.ConclusionThe impact of RRT on hospitals has been underestimated and is very relevant when calculating the total cost of RRT. Results from other countries cannot be extrapolated due to differences in the health system and patient profile. The integration of clinical databases could open up an opportunity that needs only institutional support for its development.  相似文献   
70.

Objective

This paper constitutes the first attempt to draw lessons from the recent uptake of health economic evaluation of innovative drugs in the French regulatory framework.

Study Design

Taking the example of new direct-acting antivirals against hepatitis C virus, the paper asks whether and how the cost-effectiveness (CE) opinions issued by the French National Health Authority improve the information available to support the pricing decisions.

Methods

The analysis compares the assessment of these drugs based on three different sources: CE opinions, clinical opinions, and the published cost-utility analyses (CUA) available in the literature and identified through a systematic review.

Results

The results show that CE opinions bring to the fore three issues prone to impact the incremental cost utility ratio and those were not available to the decision maker through clinical opinions or published CUA: the stage of treatment initiation, the modeling of the disease progression, and the uncertainty around the efficacy rates.

Conclusions

France has introduced the criterion of the cost per QALY gained in the pricing and regulation of innovative pharmaceuticals since 2013. Our analysis shows that the use of CUA does enhance the information available to the decision makers on the value of the treatments.  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