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   2707085篇
  免费   195533篇
  国内免费   7657篇
耳鼻咽喉   36312篇
儿科学   89481篇
妇产科学   74705篇
基础医学   382583篇
口腔科学   74359篇
临床医学   245457篇
内科学   535858篇
皮肤病学   65877篇
神经病学   226126篇
特种医学   105158篇
外国民族医学   736篇
外科学   404520篇
综合类   50917篇
现状与发展   5篇
一般理论   1018篇
预防医学   203593篇
眼科学   59644篇
药学   197017篇
  8篇
中国医学   5513篇
肿瘤学   151388篇
  2021年   21139篇
  2019年   21978篇
  2018年   32096篇
  2017年   25003篇
  2016年   29230篇
  2015年   31929篇
  2014年   43228篇
  2013年   65594篇
  2012年   86767篇
  2011年   92050篇
  2010年   55116篇
  2009年   51803篇
  2008年   86562篇
  2007年   91977篇
  2006年   93155篇
  2005年   89273篇
  2004年   85969篇
  2003年   83334篇
  2002年   80404篇
  2001年   131870篇
  2000年   135832篇
  1999年   113108篇
  1998年   32439篇
  1997年   28913篇
  1996年   28965篇
  1995年   28008篇
  1994年   25686篇
  1993年   24043篇
  1992年   85755篇
  1991年   82063篇
  1990年   79262篇
  1989年   76604篇
  1988年   69885篇
  1987年   68493篇
  1986年   63964篇
  1985年   61153篇
  1984年   45604篇
  1983年   38481篇
  1982年   23035篇
  1981年   20511篇
  1979年   39435篇
  1978年   27874篇
  1977年   23717篇
  1976年   21951篇
  1975年   23243篇
  1974年   27175篇
  1973年   25752篇
  1972年   24014篇
  1971年   22235篇
  1970年   20454篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
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   
113.
114.
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   
115.
116.
117.
118.
Behçet disease is a complex, multisystem disease characterized by recurrent oral and genital ulcerations. It rarely occurs in infants or children. Neonatal Behçet disease has been reported in infants whose ulcers resolve at or before 9 weeks of age. Few cases of neonatal Behçet disease persisting into childhood have previously been reported. We report the case of a 1‐month‐old infant who presented with severe recurrent genital ulcerations and at 6 months developed recurrent oral ulcerations. Her orogenital ulcerations continue to recur. Human leukocyte antigen testing revealed HLA‐B51 and B44 positivity. This is a case of pediatric Behçet disease in the neonatal period. Behçet disease should be considered in the differential diagnosis of recurrent genital and oral ulcerations in infants and children.  相似文献   
119.
Objectives:To report if the association of epilepsy in pediatric patients (below the age of 15 years) with Insulin-dependent Diabetes (IDDM) at King Fahad Medical City (KFMC) is higher than the prevalence of epilepsy in the same age group (who have no IDDM) in our community. Consequently, we would determine if there is a relationship between the presence of epilepsy in diabetic children and the presence of positive antiGAD65 antibodies.Methods:This cohort study included 305 pediatric patients below the age of 15 years with Insulin-dependent Diabetes Mellitus (IDDM). They were randomly recruited at the Pediatric Endocrinology Clinic in KFMC. The patients’ caregivers were given a questionnaire between December 2015 till March 2019 to determine the seizure disorder history. There was also a retrospective review of 214 patients’ files for anti-GAD 65 positivity.Results:Our study found a significant relation between the presence of epilepsy in children with IDDM. Therefore, we could confirm the relationship between the existence of epilepsy in children with IDDM and having positive GAD65 antibodies.Conclusion:Our study supports the presence of consistent relation between having IDDM and having epilepsy in children and between the latter and the presence of positive GAD65 antibodies.

Insulin dependent diabetes Mellitus (IDDM) is a common condition in children and adolescents worldwide and so is epilepsy.1,2 Recently, there were increasing reports suggesting a potential association between having IDDM and the occurrence of epilepsy.3 Their association might represent simply a chance to relate their underlying mechanisms. However, the cause-effect relationship is not fully well defined. Literature from other countries have shown the increased prevalence of seizure disorders in this group of patients.4,5 There are scarce studies in the literature investigating IDDM characteristics contributing to having epilepsy, including positive GAD 65 antibodies. In this study that ran in King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia (KSA) we are aiming to determine if the prevalence of epilepsy among 1DDM children under the age of 15 years (in our center) is higher than controls (same age without IDDM), and to check the positivity of anti-GAD 65 amongst those patients in order to find if there is a relationship between epilepsy in children with diabetes and the presence of positive GAD65 Antibodies.  相似文献   
120.
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