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   2969260篇
  免费   217242篇
  国内免费   4421篇
耳鼻咽喉   41555篇
儿科学   92118篇
妇产科学   79015篇
基础医学   433209篇
口腔科学   84549篇
临床医学   266978篇
内科学   574246篇
皮肤病学   64525篇
神经病学   233850篇
特种医学   112469篇
外国民族医学   558篇
外科学   455749篇
综合类   60895篇
现状与发展   12篇
一般理论   1031篇
预防医学   225212篇
眼科学   69586篇
药学   224178篇
  14篇
中国医学   6033篇
肿瘤学   165141篇
  2019年   23053篇
  2018年   32298篇
  2017年   24443篇
  2016年   27498篇
  2015年   30929篇
  2014年   43506篇
  2013年   65107篇
  2012年   89550篇
  2011年   94924篇
  2010年   56423篇
  2009年   53482篇
  2008年   90052篇
  2007年   95720篇
  2006年   97067篇
  2005年   93985篇
  2004年   90045篇
  2003年   86790篇
  2002年   84339篇
  2001年   142823篇
  2000年   146848篇
  1999年   123404篇
  1998年   34185篇
  1997年   29919篇
  1996年   30176篇
  1995年   28489篇
  1994年   26264篇
  1993年   24581篇
  1992年   95555篇
  1991年   92711篇
  1990年   90505篇
  1989年   87313篇
  1988年   80102篇
  1987年   78554篇
  1986年   73331篇
  1985年   70621篇
  1984年   51884篇
  1983年   44169篇
  1982年   25307篇
  1979年   47221篇
  1978年   33202篇
  1977年   27829篇
  1976年   26042篇
  1975年   28204篇
  1974年   34034篇
  1973年   32276篇
  1972年   30352篇
  1971年   28815篇
  1970年   26807篇
  1969年   25525篇
  1968年   23255篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
92.

Background

Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.

Methods

Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.

Results

Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).

Conclusions

Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF.  相似文献   
93.
94.
Purpose: To review the systemic and ocular manifestations of specific emergent viral infectious diseases relevant to the ophthalmologist with particular emphasis on anterior uveitis

Methods: Review of literature.

Results: Arboviral diseases are among the most important emergent and resurgent human infections, occurring mostly in tropical and subtropical zones, but appearing in virtually all regions of the world as a result of climate change, travel, and globalization. Arboviral infections are transmitted to humans by the bite of hematophagous arthropods, mainly mosquitoes. Systemic disease may range from asymptomatic to life-threatening. A wide variety of ocular manifestations, including uveitis, has been reported in association with these emerging viral diseases. Numerous viruses other than arboviruses also have been recently recognized as a potential cause of uveitis.

Conclusions: Proper clinical diagnosis of any emerging infectious disease is based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. The diagnosis is usually confirmed by detection of virus-specific DNA or antivirus antibodies in serum.  相似文献   
95.
Background Anti-EGFR-based therapies have limited success in HNSCC patients. Predictive biomarkers are greatly needed to identify the patients likely to be benefited from these targeted therapies. Here, we present the prognostic and predictive association of biomarkers in HPV-negative locally advanced (LA) HNSCC patients.Methods Treatment-naive tumour tissue samples of 404 patients, a subset of randomised Phase 3 trial comparing cisplatin radiation (CRT) versus nimotuzumab plus cisplatin radiation (NCRT) were analysed to evaluate the expression of HIF1α, EGFR and pEGFR by immunohistochemistry and EGFR gene copy change by FISH. Progression-free survival (PFS), locoregional control (LRC) and overall survival (OS) were estimated by Kaplan–Meier method. Hazard ratios were estimated by Cox proportional hazard models.Results Baseline characteristics of the patients were balanced between two treatment groups (CRT vs NCRT) and were representative of the trial cohort. The median follow-up was of 39.13 months. Low HIF1α was associated with better PFS [HR (95% CI) = 0.62 (0.42–0.93)], LRC [HR (95% CI) = 0.56 (0.37–0.86)] and OS [HR (95% CI) = 0.63 (0.43–0.93)] in the CRT group. Multivariable analysis revealed HIF1α as an independent negative prognostic biomarker. For patients with high HIF1α, NCRT significantly improved the outcomes [PFS:HR (95% CI) = 0.55 (0.37–0.82), LRC:HR (95% CI) = 0.55 (0.36–0.85) and OS:HR (95% CI) = 0.54 (0.36–0.81)] compared to CRT. While in patients with low HIF1α, no difference in the clinical outcomes was observed between treatments. Interaction test suggested a predictive value of HIF1α for OS (P = 0.008).Conclusions High HIF1α expression is a predictor of poor clinical response to CRT in HPV-negative LA-HNSCC patients. These patients with high HIF1α significantly benefited with the addition of nimotuzumab to CRT.Clinical trial registration Registered with the Clinical Trial Registry of India (Trial registration identifier—CTRI/2014/09/004980).Subject terms: Tumour biomarkers, Head and neck cancer, Tumour biomarkers, Head and neck cancer, Predictive markers  相似文献   
96.
97.
98.
ContextIt is especially important that patients are well informed when making high-stakes, preference-sensitive decisions like those on the Physician Orders for Life-Sustaining Treatment (POLST) form. However, there is currently no way to easily evaluate whether patients understand key concepts when making these important decisions.ObjectivesTo develop a POLST knowledge survey.MethodsExpert (n = 62) ratings of key POLST facts were used to select items for a POLST knowledge survey. The survey was administered to nursing facility residents (n = 97) and surrogate decision-makers (n = 112). A subset (n = 135) were re-administered the survey after a standardized advance care planning discussion to assess the scale's responsiveness to change.ResultsThe 19-item survey demonstrated adequate reliability (α = 0.72.). Residents' scores (x = 11.4, standard deviation 3.3) were significantly lower than surrogate scores (x = 14.7, standard deviation 2.5) (P < 0.001). Scores for both groups increased significantly after administration of a standardized advance care planning discussion (P < 0.001). Although being a surrogate, age, race, education, cognitive functioning, and health literacy were significantly associated with higher POLST Knowledge Survey scores in univariate analyses, only being a surrogate (P < 0.001) and being white (P = 0.028) remained significantly associated with higher scores in multivariate analyses.ConclusionThe 19-item POLST Knowledge Survey demonstrated adequate reliability and responsiveness to change. Findings suggest the survey could be used to identify knowledge deficits and provide targeted education to ensure adequate understanding of key clinical decisions when completing POLST.  相似文献   
99.
100.
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