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   21819篇
  免费   1750篇
  国内免费   523篇
耳鼻咽喉   1648篇
儿科学   383篇
妇产科学   289篇
基础医学   1384篇
口腔科学   657篇
临床医学   3435篇
内科学   2819篇
皮肤病学   253篇
神经病学   1673篇
特种医学   1816篇
外科学   1657篇
综合类   2761篇
现状与发展   2篇
一般理论   4篇
预防医学   1409篇
眼科学   1956篇
药学   1193篇
  11篇
中国医学   442篇
肿瘤学   300篇
  2024年   36篇
  2023年   356篇
  2022年   529篇
  2021年   1030篇
  2020年   980篇
  2019年   900篇
  2018年   886篇
  2017年   812篇
  2016年   974篇
  2015年   902篇
  2014年   1575篇
  2013年   1620篇
  2012年   1243篇
  2011年   1296篇
  2010年   1077篇
  2009年   1086篇
  2008年   1057篇
  2007年   1097篇
  2006年   1017篇
  2005年   790篇
  2004年   649篇
  2003年   557篇
  2002年   437篇
  2001年   388篇
  2000年   312篇
  1999年   282篇
  1998年   244篇
  1997年   198篇
  1996年   156篇
  1995年   151篇
  1994年   173篇
  1993年   115篇
  1992年   137篇
  1991年   91篇
  1990年   95篇
  1989年   89篇
  1988年   84篇
  1987年   65篇
  1986年   73篇
  1985年   101篇
  1984年   78篇
  1983年   53篇
  1982年   78篇
  1981年   51篇
  1980年   57篇
  1979年   32篇
  1978年   34篇
  1977年   13篇
  1976年   13篇
  1975年   11篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
The availability of human papillomavirus (HPV) vaccines and screening tests has raised the possibility of globally eliminating cervical cancer, which is caused by HPV. Cervical cancer is a very common malignancy worldwide, especially among deprived women. High vaccination coverage is key to the containment and eventual elimination of the infection. Public HPV vaccination programmes in Italy and Denmark were swiftly established and are among the most successful worldwide. Still, in both countries, it has been challenging to achieve and maintain the recommended coverage of > 80% in girls. In a well‐studied Italian region, vaccination coverage in girls at age 15 years (World Health Organization''s gold standard) reached 76% in 2015 but decreased to 69% in 2018, likely due to work overload in public immunization centres. In Denmark, doubts about safety and efficacy of the HPV vaccine generated a decline in coverage among girls age 12–17, from 80% in 2013 down to 37% in 2015, when remedial actions made it rise again. Insights from these two countries are shared to illustrate the importance of monitoring coverage in a digital vaccine registry and promptly reacting to misinformation about vaccination.

Abbreviations

CC
cervical cancer
FVG
Friuli Venezia Giulia
HICs
high‐income countries
HPV
human papillomavirus
LMICs
middle‐income countries
WHO
World Health Organization
  相似文献   
32.
Calcified tissue is a common component of atherosclerotic plaques, and occurs most often in mature plaques. The process of calcification is a poorly understood risk factor that may contribute to a plaque's vulnerability to sudden rupture. In this study a solid-state imaging sequence, termed single-point imaging (SPI), was used to observe calcification directly in ex vivo atherosclerotic plaques. Standards were used to validate the ability of (31)P SPI to detect and differentiate calcification from crystalline cholesterol, phospholipids, and other plaque components. After suitable experimental parameters were found, human carotid specimens obtained by endarterectomy were imaged ex vivo by (31)P solid-state imaging and standard (1)H methods. In contrast to (1)H imaging methods, (31)P imaging detected only the calcification in the plaque.  相似文献   
33.
Background The Retinal Thickness Analyser (RTA) is intended to detect glaucomatous changes as well as macular pathologies at the posterior pole. We determined the diagnostic accuracy for eyes with manifest glaucoma or macular diseases.Methods We examined 71 eyes with long-term, established eye conditions. Included were 28 eyes with glaucoma, 21 with different macular diseases and 22 normal eyes. All examinations were evaluated in a blind-test by RTA experts without any clinical information on the patients. After comparison of the RTA interpretation with the clinical diagnosis, we determined sensitivity, specificity, positive and negative predictive values.Results Of 71 examinations, 15 (21%) were not interpretable. If these results are excluded, the following diagnostic accuracy values were calculated for glaucoma and macular disorders respectively: sensitivity 75 and 59%, specificity 55 and 97%, positive predictive value 48 and 90% and negative predictive value 80 and 84%. These values were not significantly different when both eyes of each patient were included in the final analysis (n=133).Conclusion The diagnostic values of the RTA determined in this case control study were not satisfactory. However, no clinical information was used in the assessment. The extent to which additional clinical information increases the diagnostic value remains to be determined.  相似文献   
34.
设计并试制了一种药用胶带纸层厚度在线检测系统.该系统将高精度电容传感器与计算机结合起来,同时配有丰富的外围器件,实现了多种实际生产中所需要的功能.它的出现,彻底解决了药用胶带纸胶层厚度在线检测这个难题,经过两年多的实际应用的检验,该系统实现了在线非接触测量,精度高,动态性能好,实现功能全面,价格合理,是药用胶带纸生产的必备检测仪器.由于该系统还可以很方便在纸张、塑料薄膜等其它生产线上进行推广,因而,其应用前景十分看好.  相似文献   
35.
目的:观察喉罩全麻下行颈动脉狭窄的造影诊断及介入治疗术的临床效果。方法:择期DSA下颈动脉狭窄患者23例,年龄42-78岁,无明显肺部疾患及喉罩禁忌症患者,异丙酚(Pmpofol)泵入静脉全麻下插入喉罩完成手术,观察其不同时段的BP(MAP)、SpO2、HR、ECG(ST-Ⅱ)。结果:各时段的BP(MAP)、Sp02、HR、ECG(ST-Ⅱ)比较无显著性差异。结论:喉罩全麻在行颈动脉狭窄的造影诊断及介入治疗术的临床效果是肯定的。喉罩全麻颈动脉狭窄造影介入治疗  相似文献   
36.
Summary In 1981 generalized anaphylaxis was registered on 166 occasions in Dutch general and academic hospitals. Clinical details of 120 of those patients revealed that in 107 anaphylaxis was either probable (n=90) or possible (n=17), whereas in 13 cases some other reaction than anaphylaxis had occurred. The series of confirmed cases contained 46 men and 61 women, with mean ages of 47 y and 48 y, respectively.There was a complete recovery in 102 patients and two patients died. Hypotension was present in 79 cases (74%), dyspnoea in 34 cases (32%) and a skin reaction, mainly urticaria, erythema or angioedema, was mentioned in 62 cases (58%). Most cases of anaphylaxis were drug-induced (76%), the main causes being the analgesic glafenine and contrast media. Glafenine was mentioned as the cause in 36% of all admissions for drug-induced anaphylaxis. Only 3.7% of cases had been reported to the voluntary reporting scheme of the Netherlands Centre for Monitoring of Adverse Reactions to Drugs.On the basis of reimbursement data, the risk of developing severe anaphylaxis to glafenine was estimated at 11.7–19.3-fold relative to indomethacin, and 13.4–20.2-fold relative to oral penicillins.  相似文献   
37.
Although common carotid artery (CCA) occlusions are rare, acute clinical presentations vary from mild to devastating strokes primarily due to tandem occlusions in the intracranial arteries. Three patients with acute CCA occlusions were treated with systemic tissue plasminogen activator (TPA). Blood pressures were kept at the upper limits allowed with TPA therapy with fluid balance and the 'head-down' position. Recanalization occurred in intracranial vessels only. Marked early neurological improvement occurred in two of three patients. CCA occlusions should not be considered contra-indication to systemic thrombolysis.  相似文献   
38.
39.
目的:研究载脂蛋白E(ApoE)基因多态性与颈动脉粥样硬化的相关性。方法:应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)技术,对25例B超检测颈动脉内中膜厚度(IMT)增厚患者(增厚组)和25例同期健康体检者(对照组)的ApoE基因多态性进行分析。结果:IMT增厚组ε3等位基因频率较对照组降低(P<0.05),ε4等位基因频率较对照组升高(P<0.01)。IMT增厚组的ε3/ε4基因型频率显著要高于对照组。对以上两组再按ApoE基因型分别分为3组:ApoE2(ε2/2 ε2/3),ApoE3(ε3/3)和ApoE4(ε3/4 ε4/4)。结果显示颈动脉IMT在不同基因型间差异显著,ApoE4组显著增加,颈动脉多发斑块率在此组也显著增加。结论:ApoE基因多态性与颈动脉粥样硬化形成有相关性,ε4基因是颈动脉粥样硬化形成的危险因子。  相似文献   
40.
目的:探讨高分辨率CT(HRCT)诊断慢性中耳炎的的价值。方法:回顾分析56例(耳)慢性化脓性中耳炎,比较术前HRCT检查与手术所见。结果:胆脂瘤型中耳炎30例HRCT表现为鼓室或(及)鼓窦内团块软组织影和骨质改变,包括听骨移位、破坏,盾板破坏及中耳腔扩大,有的伴有乙状窦、天盖,水平半规管破坏;骨疡型中耳炎21例HRCT表现多呈斑片状、条索状或网状软组织影,部分可见液平面,听骨移位及破坏较轻;单纯型中耳炎HRCT表现大多无异常。HRCT所见与手术结果基本相符,符合率为96.4%。结论:HRCT有助于慢性化脓性中耳炎的诊断分型。  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