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   353018篇
  免费   26618篇
  国内免费   2835篇
耳鼻咽喉   7691篇
儿科学   10769篇
妇产科学   6704篇
基础医学   30275篇
口腔科学   8599篇
临床医学   37587篇
内科学   90166篇
皮肤病学   12299篇
神经病学   30185篇
特种医学   10917篇
外国民族医学   1篇
外科学   63582篇
综合类   1161篇
现状与发展   72篇
一般理论   37篇
预防医学   28568篇
眼科学   8255篇
药学   15264篇
  9篇
中国医学   766篇
肿瘤学   19564篇
  2024年   1200篇
  2023年   6041篇
  2022年   2532篇
  2021年   6600篇
  2020年   7826篇
  2019年   5776篇
  2018年   13023篇
  2017年   10744篇
  2016年   11873篇
  2015年   12336篇
  2014年   20106篇
  2013年   22472篇
  2012年   17603篇
  2011年   18329篇
  2010年   16767篇
  2009年   18991篇
  2008年   16245篇
  2007年   15194篇
  2006年   17127篇
  2005年   14041篇
  2004年   12447篇
  2003年   10823篇
  2002年   10378篇
  2001年   8781篇
  2000年   8523篇
  1999年   7509篇
  1998年   4586篇
  1997年   4085篇
  1996年   3966篇
  1995年   3755篇
  1994年   2388篇
  1993年   1924篇
  1992年   3670篇
  1991年   3462篇
  1990年   3069篇
  1989年   2882篇
  1988年   2650篇
  1987年   2383篇
  1986年   2458篇
  1985年   2202篇
  1984年   1626篇
  1983年   1459篇
  1979年   1542篇
  1977年   1217篇
  1975年   1173篇
  1974年   1359篇
  1973年   1411篇
  1972年   1426篇
  1971年   1286篇
  1970年   1269篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Resident physicians are continually exposed to fatigue, which can lead to work, academic and personal problems, so it is important to have reliable and valid instruments to measure it. One of the most used is Fatigue Severity Scale, but, there are versions with different number of items in different populations. Therefore, the purpose of this work was to translate, adapt culturally relevant and compare versions with different numbers of items, to identify the most appropriate in Mexican resident physicians. With three different groups of participants; first one for translation by seven expert judges in the language, second for psychometric validation with 100 resident physicians, and third for confirmatory factor analysis and invariance test by type of program (specialty and high specialty) with 182 resident physicians. Distribution, discrimination, reliability and factor structure of the scale were tested in an exploratory and confirmatory analysis, leaving a final scale of 6 items with good fit (X2[9] = 9,39, p = 0,40; CFI = 0,99; RMSEA = 0,02), with a reliability = 0,91 and strict factorial invariance by type of residence program.  相似文献   
43.
44.
Brain Structure and Function - Accumulating evidence suggests that besides its function in early facial feature processing, the role of the right occipital face area (rOFA) extends to higher level,...  相似文献   
45.
46.
BackgroundFluoroquinolones are a popular alternative to trimethoprim-sulfamethoxazole for Stenotrophomonas maltophilia infections.ObjectivesTo compare the effects of fluoroquinolones and trimethoprim-sulfamethoxazole on mortality of S. maltophilia infections.Data sourcesPubMed and EMBASE.Study eligibility criteriaClinical studies reporting mortality outcomes of S. maltophilia infections.ParticipantsPatients with clinical infections caused by S. maltophilia.InterventionsFluoroquinolone monotherapy in comparison with trimethoprim-sulfamethoxazole monotherapy.MethodsSystematic review with meta-analysis technique.ResultsSeven retrospective cohort and seven case–control studies were included. Three cohort studies were designed to compare the two drugs, whereas others had other purposes. A total of 663 patients were identified, 332 of which were treated with trimethoprim-sulfamethoxazole (50.1%) and 331 with fluoroquinolones (49.9%). Three cohort studies were designed to compare the effect of the two drugs, whereas the others had other purposes. Levofloxacin was most frequently used among fluoroquinolones (187/331, 56.5%), followed by ciprofloxacin (114/331, 34.4%). The overall mortality rate was 29.6%. Using pooled ORs for the mortality of each study, fluoroquinolone treatment (OR 0.62, 95% CI 0.39–0.99) was associated with survival benefit over trimethoprim-sulfamethoxazole treatment, with low heterogeneity (I2 = 18%). Specific fluoroquinolones such as ciprofloxacin (OR 0.44, 95% CI 0.17–1.12) and levofloxacin (OR 0.78, 95% CI 0.48–1.26) did not show a significant difference in comparison with trimethoprim-sulfamethoxazole. In the sub-group analyses of adult and bacteraemic patients, significant differences in mortality were not observed between fluoroquinolones and trimethoprim-sulfamethoxazole.ConclusionsBased on a meta-analysis of non-randomized studies, fluoroquinolones demonstrated comparable effects on mortality of S. maltophilia infection to trimethoprim-sulfamethoxazole, supporting the use of fluoroquinolones in clinical S. maltophilia infections. Although the pooled analysis of overall studies favoured fluoroquinolones over trimethoprim-sulfamethoxazole, the studies included were observational, and sub-group analyses of certain fluoroquinolone agents did not show statistical differences with trimethoprim-sulfamethoxazole. Randomized clinical studies are needed to address these issues.  相似文献   
47.
European Journal of Applied Physiology - We examined the possibility that old adults use flexibility in joint coordination as a compensatory mechanism for the age-related decline in muscle strength...  相似文献   
48.
49.
The measures for leishmaniasis control include the precise diagnosis of disease. However, although several recombinant antigens have been tested with this biotechnological purpose, no effective product exists, which could detects patients with the active disease, as well as differentiates them from cured and treated patients. In this study, a conserved Leishmania hypothetical protein, which was identified in Leishmania infantum parasites, but evaluated to presents high homology in the amino acid sequences between distinct parasite species, was evaluated for the diagnosis of tegumentary and visceral leishmaniasis. In addition, PBMCs collected from treated and untreated mucosal leishmaniasis (ML) and visceral leishmaniasis (VL) patients, as well as in healthy subjects living in endemic region of disease, were in vitro stimulated, when IFN-γ, IL-4 and IL-10 levels were evaluated in the cell supernatant. Regarding the serological analyses, ELISA experiments using the recombinant protein (rLiHyL) and a human serological panel revealed high sensitivity and specificity values to detect both diseases, while control antigens showed worst results. Regarding the cellular response, results showed that rLiHyL-stimulated cells produced higher IFN-γ and lower IL-4 and IL-10 levels in the supernatants. Also, the anti-protein antibody production was evaluated in these patients, and data showed higher IgG2 and lower IgG1 levels found in the treated patients and healthy controls, demonstrating the stimulation of a Th1-type response induced by the rLiHyL protein. In conclusion, this hypothetical protein can be considered as antigenic in TL and VL, as well as a vaccine candidate to be tested in future studies to protect against disease.  相似文献   
50.
BackgroundDendritic cells (DCs) are usually immunogenic, but they are also capable of inducing tolerance under anti-inflammatory conditions. Immunotherapy based on autologous DCs loaded with an allogeneic melanoma cell lysate (TRIMEL/DCs) induces immunological responses and increases melanoma patient survival. Glucocorticoids can suppress DC maturation and function, leading to a DC-mediated inhibition of T cell responses.MethodsThe effect of dexamethasone, a glucocorticoid extensively used in cancer therapies, on TRIMEL/DCs phenotype and immunogenicity was examined.ResultsDexamethasone induced a semi-mature phenotype on TRIMEL/DC with low maturation surface marker expressions, decreased pro-inflammatory cytokine induction (IL-1β and IL-12) and increased release of regulatory cytokines (IL-10 and TGF-β). Dexamethasone-treated TRIMEL/DCs inhibited allogeneic CD4+ T cell proliferation and cytokine release (IFNγ, TNF-α and IL-17). Co-culturing melanoma-specific memory tumor-infiltrating lymphocytes with dexamethasone-treated TRIMEL/DC inhibited proliferation and effector T cell activities, including cytokine secretion and anti-melanoma cytotoxicity.ConclusionsThese findings suggest that dexamethasone repressed melanoma cell lysate-mediated DC maturation, generating a potent tolerogenic-like DC phenotype that inhibited melanoma-specific effector T cell activities. These results suggest that dexamethasone-induced immunosuppression may interfere with the clinical efficacy of DC-based melanoma vaccines, and must be taken into account for optimal design of cellular therapy against cancer.  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