全文获取类型
收费全文 | 1442886篇 |
免费 | 119466篇 |
国内免费 | 6070篇 |
专业分类
耳鼻咽喉 | 18629篇 |
儿科学 | 47015篇 |
妇产科学 | 41344篇 |
基础医学 | 203556篇 |
口腔科学 | 38325篇 |
临床医学 | 130636篇 |
内科学 | 287306篇 |
皮肤病学 | 33776篇 |
神经病学 | 117993篇 |
特种医学 | 55259篇 |
外国民族医学 | 466篇 |
外科学 | 213434篇 |
综合类 | 42526篇 |
现状与发展 | 19篇 |
一般理论 | 487篇 |
预防医学 | 113020篇 |
眼科学 | 32259篇 |
药学 | 102698篇 |
52篇 | |
中国医学 | 6344篇 |
肿瘤学 | 83278篇 |
出版年
2021年 | 12391篇 |
2019年 | 12652篇 |
2018年 | 17588篇 |
2017年 | 13793篇 |
2016年 | 15249篇 |
2015年 | 17553篇 |
2014年 | 24565篇 |
2013年 | 35570篇 |
2012年 | 48577篇 |
2011年 | 51420篇 |
2010年 | 31011篇 |
2009年 | 29463篇 |
2008年 | 46846篇 |
2007年 | 49376篇 |
2006年 | 49754篇 |
2005年 | 47807篇 |
2004年 | 45507篇 |
2003年 | 43419篇 |
2002年 | 41728篇 |
2001年 | 74158篇 |
2000年 | 75319篇 |
1999年 | 62051篇 |
1998年 | 17278篇 |
1997年 | 15747篇 |
1996年 | 15815篇 |
1995年 | 14980篇 |
1994年 | 13490篇 |
1993年 | 12594篇 |
1992年 | 45856篇 |
1991年 | 43531篇 |
1990年 | 41502篇 |
1989年 | 39576篇 |
1988年 | 36168篇 |
1987年 | 35347篇 |
1986年 | 32846篇 |
1985年 | 31259篇 |
1984年 | 23786篇 |
1983年 | 19966篇 |
1982年 | 12162篇 |
1981年 | 10726篇 |
1979年 | 20658篇 |
1978年 | 14546篇 |
1977年 | 12034篇 |
1976年 | 11313篇 |
1975年 | 11583篇 |
1974年 | 13965篇 |
1973年 | 13512篇 |
1972年 | 12622篇 |
1971年 | 11459篇 |
1970年 | 10894篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
62.
63.
目的 利用频域光学相干断层扫描深度增强(enhanced depth imaging spectral domain optical coherence tomography,EDI SD-OCT)观察糖尿病黄斑水肿(diabetic macular edema,DME)患者脉络膜厚度(choroidal thickness,CT)的变化及结构特点,探讨DME病变程度与CT的关系。方法 纳入2型糖尿病患者共123例204眼,其中69眼诊断为DME(DME组),135眼无黄斑水肿为对照组。DME眼依据OCT形态学特点进一步分为视网膜弥漫性增厚(diffuse retinal thickness,DRT)型(34眼)、黄斑囊样水肿(cystoid macular edema,CME)型(19眼)和浆液性视网膜脱离(serous retinal detachment,SRD)型(16眼),利用EDI-OCT分别测量黄斑中心凹下CT和以黄斑为中心上、下、鼻、颞500 μm、1000 μm、1500 μm、2000 μm处CT。结果 DME组黄斑中心凹下CT为(326.72±90.15)μm,对照组为(320.17±106.46)μm,两组之间无统计学差异,但黄斑中心凹下CT与视网膜厚度间具有明显正相关关系(r=0.270,P=0.025)。DME亚型CT分别为:DRT型(303.94±81.47)μm、CME型(304.42±73.98)μm和SRD型(401.63±88.80)μm,SRD型CT明显高于其他亚型(P<0.05),此外,SRD型的周边CT同样呈现均匀一致的增厚;鼻侧CT从500 μm至2000 μm呈距离敏感性降低(P<0.05),但SRD型鼻侧CT降低幅度明显变缓(P=0.195)。结论 SRD型黄斑水肿患者CT在中心凹下及周边部均显著增厚,CT与DME病变程度之间有一定相关性。 相似文献
64.
Susan E. Hickman Alexia M. Torke Greg A. Sachs Rebecca L. Sudore Anne L. Myers Qing Tang Giorgos Bakoyannis Bernard J. Hammes 《Journal of pain and symptom management》2019,57(6):1143-1150.e5
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
65.
目的 对2014-2016年在甘肃省和政县开展的白内障综合防盲干预项目进行卫生经济学评价。设计 横断面调查。 研究对象 甘肃省和政县2014-2016年老年性白内障手术前407例患者及术后半年109例患者。方法 对所有调查对象进行卫生经济学问卷调查。通过净效益法、成本效益分析法和成本效果分析法评价项目产生的经济效益和总成本。主要指标 直接成本、间接成本、直接经济效益、间接经济效益、总成本、总效益、净效益、成本效益比、成本效果比。结果 2014-2016年项目期间甘肃省和政县白内障所致总体疾病经济负担为2142.28万元。白内障手术产生的总效益为3398424.98元,总成本为2939125.20元,净效益为459299.78元,效益成本比为1.16:1。项目每投入1万元可降低50岁以上白内障患者导致的0.027%的致盲率和0.164%致残率;项目每降低1%的50岁以上白内障患者的盲率,需投入36.47万元;每降低1%50岁以上白内障患者的残率,需投入6.11万元。结论 在甘肃省和政县开展的老年性白内障防盲综合干预项目具有较好的产出回报比和较高的防盲技术效率。(眼科,2020,29: 298-303) 相似文献
66.
Recurrent Oral and Genital Ulcers in an Infant: Neonatal Presentation of Pediatric Behçet Disease 下载免费PDF全文
Emma F. Johnson M.D. Danielle M. Hawkins M.D. Laura K. Gifford M.D. Aimee C. Smidt M.D. 《Pediatric dermatology》2015,32(5):714-717
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
67.
Dermoscopic difficult lesions: an objective evaluation of reflectance confocal microscopy impact for accurate diagnosis 下载免费PDF全文
68.
69.
Jinju Wang Shuzhen Chen Wenfeng Zhang Yanfang Chen Ji C. Bihl 《CNS Neuroscience & Therapeutics》2020,26(12):1255
AimsWe previously showed that the protective effects of endothelial progenitor cells (EPCs)‐released exosomes (EPC‐EXs) on endothelium in diabetes. However, whether EPC‐EXs are protective in diabetic ischemic stroke is unknown. Here, we investigated the effects of EPC‐EXs on diabetic stroke mice and tested whether miR‐126 enriched EPC‐EXs (EPC‐EXsmiR126) have enhanced efficacy.MethodsThe db/db mice subjected to ischemic stroke were intravenously administrated with EPC‐EXs 2 hours after ischemic stroke. The infarct volume, cerebral microvascular density (MVD), cerebral blood flow (CBF), neurological function, angiogenesis and neurogenesis, and levels of cleaved caspase‐3, miR‐126, and VEGFR2 were measured on day 2 and 14.ResultsWe found that (a) injected EPC‐EXs merged with brain endothelial cells, neurons, astrocytes, and microglia in the peri‐infarct area; (b) EPC‐EXsmiR126 were more effective than EPC‐EXs in decreasing infarct size and increasing CBF and MVD, and in promoting angiogenesis and neurogenesis as well as neurological functional recovery; (c) These effects were accompanied with downregulated cleaved caspase‐3 on day 2 and vascular endothelial growth factor receptor 2 (VEGFR2) upregulation till day 14.ConclusionOur results indicate that enrichment of miR126 enhanced the therapeutic efficacy of EPC‐EXs on diabetic ischemic stroke by attenuating acute injury and promoting neurological function recovery. 相似文献