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   48471篇
  免费   5043篇
  国内免费   1487篇
耳鼻咽喉   265篇
儿科学   1737篇
妇产科学   405篇
基础医学   6536篇
口腔科学   1378篇
临床医学   5134篇
内科学   10380篇
皮肤病学   1327篇
神经病学   2527篇
特种医学   849篇
外国民族医学   5篇
外科学   3624篇
综合类   7647篇
现状与发展   4篇
一般理论   1篇
预防医学   3077篇
眼科学   823篇
药学   4630篇
  28篇
中国医学   3268篇
肿瘤学   1356篇
  2024年   174篇
  2023年   1002篇
  2022年   1147篇
  2021年   2348篇
  2020年   2233篇
  2019年   1930篇
  2018年   1850篇
  2017年   2053篇
  2016年   2152篇
  2015年   1961篇
  2014年   3494篇
  2013年   3856篇
  2012年   3501篇
  2011年   3576篇
  2010年   2731篇
  2009年   2596篇
  2008年   2429篇
  2007年   2186篇
  2006年   1943篇
  2005年   1702篇
  2004年   1368篇
  2003年   1139篇
  2002年   987篇
  2001年   878篇
  2000年   681篇
  1999年   594篇
  1998年   577篇
  1997年   448篇
  1996年   459篇
  1995年   349篇
  1994年   317篇
  1993年   280篇
  1992年   280篇
  1991年   224篇
  1990年   190篇
  1989年   161篇
  1988年   147篇
  1987年   141篇
  1986年   124篇
  1985年   147篇
  1984年   125篇
  1983年   88篇
  1982年   92篇
  1981年   78篇
  1980年   62篇
  1979年   44篇
  1978年   39篇
  1977年   36篇
  1976年   34篇
  1974年   12篇
排序方式: 共有10000条查询结果,搜索用时 953 毫秒
61.
杨艳 《新中医》2020,52(4):40-43
目的:观察通心络胶囊联合阿托伐他汀、氯吡格雷治疗冠心病心绞痛的临床疗效。方法:选取84例冠心病心绞痛患者,按随机数字表法分为观察组与对照组,对照组40例给予阿托伐他汀联合氯吡格雷治疗,观察组44例在对照组基础上给予通心络胶囊治疗,3个月后比较2组临床疗效。结果:观察组总有效率(93.18%)显著高于对照组(70.00%),差异有统计学意义(P<0.05)。治疗前,2组心绞痛的持续时间、心绞痛发作次数、心功能指标、血管内皮功能指标比较,差异无统计学意义(P>0.05)。治疗后,2组心绞痛持续时间、心绞痛发作次数较治疗前明显降低,观察组心绞痛持续时间、心绞痛发作次数显著低于对照组(P<0.05);2组心功能指标包括心输出量(CO)、心博出量(SV)、心脏指数(CI)及射血分数(EF)均较治疗前明显上升,且观察组各项心功能指标明显高于对照组(P<0.05);2组内皮功能指标内皮素(ET)、血栓素B2(TXB2)水平较治疗前明显降低,一氧化氮(NO)水平较治疗前明显上升(P<0.05),观察组ET、TXB2水平明显低于对照组,NO水平明显高于对照组(P<0.05)。结论:对冠心病心绞痛患者给予通心络胶囊联合阿托伐他汀、氯吡格雷治疗疗效显著,可有效降低心绞痛持续时间和发作次数,改善患者心功能和内皮功能,值得临床推广应用。  相似文献   
62.
《Value in health》2020,23(10):1340-1348
ObjectivesWe applied principles for conducting economic evaluations of factorial trials to a trial-based economic evaluation of a cluster-randomized 2 × 2 × 2 factorial trial. We assessed the cost-effectiveness of atorvastatin, omega-3 fish oil, and an action-planning leaflet, alone and in combination, from a UK National Health Service perspective.MethodsThe Atorvastatin in Factorial With Omega EE90 Risk Reduction in Diabetes (AFORRD) Trial randomized 800 patients with type 2 diabetes to atorvastatin, omega-3, or their respective placebos and randomized general practices to receive a leaflet-based action-planning intervention designed to improve compliance or standard care. The trial was conducted at 59 UK general practices. Sixteen-week outcomes for each trial participant were extrapolated for 70 years using the United Kingdom Prospective Diabetes Study Outcomes Model v2.01. We analyzed the trial as a 2 × 2 factorial trial (ignoring interactions between action-planning leaflet and medication), as a 2 × 2 × 2 factorial trial (considering all interactions), and ignoring all interactions.ResultsWe observed several qualitative interactions for costs and quality-adjusted life-years (QALYs) that changed treatment rankings. However, different approaches to analyzing the factorial design did not change the conclusions. There was a ≥99% chance that atorvastatin is cost-effective and omega-3 is not, at a £20 000/QALY threshold.ConclusionsAtorvastatin monotherapy was the most cost-effective combination of the 3 trial interventions at a £20 000/QALY threshold. Omega-3 fish oil was not cost-effective, while there was insufficient evidence to draw firm conclusions about action planning. Recently-developed methods for analyzing factorial trials and combining parameter and sampling uncertainty were extended to estimate cost-effectiveness acceptability curves within a 2x2x2 factorial design with model-based extrapolation.  相似文献   
63.
目的分析研究绝经后女性2型糖尿病伴骨质疏松症患者骨密度与骨代谢指标的相关性。方法选取2013年10月至2017年05月于重庆医科大学附属第一医院内分泌内科住院的绝经后女性2型糖尿病患者385名。搜集其基本资料、骨代谢指标及骨密度等。根据T值将这些患者分为骨质疏松组(233例)、骨量减少组(101例)和骨量正常组(51例),比较三组间骨代谢指标的变化,并对骨密度(bone mineral density,BMD)与各项骨代谢指标进行相关性分析。结果 1型前胶原氨基末端前肽(Type I procollagen N-terminal propeptide,P1NP)、骨钙素(bone Gla protein,BGP)在骨质疏松组显著高于骨量减少组、骨量正常组(P0.05);随着骨密度的降低,1型胶原羧基端肽β特殊序列(β-Carboxyl terminal peptide,β-CTX)逐渐升高,骨质疏松组、骨量减少组与骨量正常组相比较差异有统计学意义(P0.05);Spearman等级相关分析示P1NP、BGP、β-CTX与骨密度呈负相关,25(OH)D_3与骨密度呈现正相关。结论绝经后女性2型糖尿病伴骨质疏松症患者骨密度与骨代谢指标有一定的相关性,有助于预测骨折风险并及时抗骨质疏松治疗。  相似文献   
64.
目的探讨眼睑恶性肿瘤切除术中应用Z形皮瓣及推进皮瓣I期修复眼睑缺损的临床效果。方法将50例眼睑恶性肿瘤切除术患者按不同缝合方法分为两组,即对照组25例,术中直接缝合;观察组25例,术中行Z形皮瓣及推进皮瓣I期修复;比较两组眼睑修复效果。结果观察组术后皮瓣成活率96.0%、切口Ⅰ期愈合率100%、修复满意率92.0%,均高于对照组的72.0%、68.0%、56.0%,差异有统计学意义(P<0.05)。观察组术后并发症发生率低于对照组,但差异无统计学意义(P>0.05)。结论眼睑恶性肿瘤切除术中眼睑缺损修复时,采用Z形皮瓣及推进皮瓣,眼睑修复良好,患者修复满意率高,值得推广应用。  相似文献   
65.
目的观察祛寒逐风合剂联合西医常规疗法对膝骨关节炎风寒痹阻证的临床疗效,以及对关节症状及相关实验室指标的影响。方法采用随机数字表法将94例膝骨关节炎风寒痹阻证患者分为观察组和对照组各47例。对照组采用常规药物疗法+康复训练,观察组在对照组基础上予祛寒逐风合剂,每次50m L,每日3次,口服。2组均连续治疗2周。比较2组临床疗效,观察2组治疗前后美国西大略湖和麦克马斯特大学骨关节炎指数(WOMAC)评分、视觉模拟评分法(VAS)评分、压痛指数、中医症状评分,白细胞介素(IL)-1β、IL-6、血管内皮生长因子(VEGF)、肿瘤坏死因子(TNF)-α、骨钙素、抗酒石酸盐酸性磷酸酶异构体(TRACP)-5b、骨特异性碱性磷酸酶(BALP)、纤维蛋白原、红细胞沉降率和红细胞聚集指数,对2组进行安全性评价。结果观察组总有效率为89.36%(42/47),对照组为74.47%(35/47),观察组明显优于对照组(P<0.05)。与本组治疗前比较,2组治疗后WOMAC评分、VAS评分、压痛指数、中医症状评分明显下降(P<0.05);2组治疗后比较,观察组WOMAC评分、VAS评分、压痛指数、中医症状评分明显低于对照组(P<0.05)。与本组治疗前比较,2组治疗后IL-1β、IL-6、TNF-α、VEGF、TRACP-5b水平明显下降,骨钙素、BALP水平明显升高(P<0.05);2组治疗后比较,观察组IL-1β、IL-6、TNF-α、VEGF、TRACP-5b水平明显低于对照组,骨钙素、BALP水平明显高于对照组(P<0.05)。与本组治疗前比较,观察组治疗后纤维蛋白原、红细胞沉降率、红细胞聚集指数明显下降(P<0.05);2组治疗后比较,观察组血液流变学各项指标明显低于对照组(P<0.05)。2组均未发生不良反应。结论祛寒逐风合剂联合西医常规疗法治疗膝骨关节炎风寒痹阻证患者疗效较好,可明显改善关节症状及相关实验室指标。  相似文献   
66.
67.
PURPOSE: The purpose of this study was to compare the dentin/adhesive interfacial characteristics when bonding to noncarious as well as caries-affected dentin. MATERIALS AND METHODS: Seven extracted, unerupted, third molars were sectioned into halves. Artificial caries was created on one-half of each tooth, leaving the other half as a control. Dentin surfaces were treated with UNO adhesive according to the manufacturer's instructions for the wet-bonding technique and under environmental conditions present in the oral cavity. Dentin/adhesive interface sections of each half-tooth were stained with Goldner's trichrome, a classic bone stain, and examined using light microscopy. The width of exposed collagen was measured directly from photomicrographs, and adhesive penetration was analyzed qualitatively. RESULTS: The degree and extent to which the adhesive encapsulated the demineralized dentin matrix were reflected in the color difference in the stained sections with the noncarious dentin sections showing a degree of collagen encapsulation superior to that of the caries-affected dentin sections. The overall mean widths of exposed collagen were significantly (p < or = .05) greater at the caries-affected dentin/adhesive interface, 8.6 (1.7) microm, as compared with those at the noncarious dentin/adhesive interface, 6.0 (1.5) microm. CONCLUSIONS: The morphologic characteristics of the caries-affected dentin/interface suggest an increase in the exposed collagen zone and a decrease in the quality of the adhesive infiltration when compared with noncarious dentin. The evidence suggests that dentin substrate characteristics have a significant effect on the dentin/adhesive interface structure.  相似文献   
68.
Many health-related research studies among Seventh-day Adventists (SDA) were published since 1958. Californian and Norwegian studies have shown that SDA have lower coronary mortality rates than the general population. This finding is usually attributed to the lifestyle advocated by the Seventh-day Adventist church with greater physical activity, lower median BMI, abstention from use of alcohol and tobacco, food habits characterized by a large intake of fruits, vegetables, cereal fiber, unsaturated fatty acids and a low consumption of saturated fats. The results about cancer incidence were discussed. Californian studies have shown significantly decreased relative risk in SDA than in the general population. Japanese studies have also reported lower risk of cancers in men with lifestyles similar to those of SDA. By contrast the Norwegian study of SDA has shown that the risk of cancer seems to be similar to that of the general population. Some studies reported a greater prevalence of type 2 diabetes in the non vegetarian SDA than the vegetarian. Compared with vegetarian, non vegetarian SDA reported more medication use, more chronic diseases, more hospitalizations and surgeries. Lifestyle choices of SDA as above described could prevent a great many coronary artery disease and type 2 diabetes. This lifestyle is now emphasized by French PNNS.  相似文献   
69.
精液中PAI-1含量与精液液化的关系   总被引:1,自引:1,他引:0  
目的测定精液中纤溶酶原激活物抑制剂-1(plasminogen activator inhibitor type-1,PAI-1)的含量,探讨精液的液化机制。方法分别检测门诊患者1h内不液化精液40例(A组)和1h内液化精液30例(B组)中PAI- 1的含量。结果A组PAI-1含量为(10.25±0.75)ng/ml,B组为(6.46±0.37)ng/ml,A组含量显著高于B组,P<0.01,差异有统计学意义。精液中PAI-1含量与精液液化时间的相关性r=0.362,P<0.01,呈正相关。结论精液中PAI-1含量升高,可导致精液液化时间延长,可作为检测精液粘稠度的一个相对指标。  相似文献   
70.
Objective: Induction chemoradiotherapy followed by anatomical resection is a current therapeutic strategy for non-small-cell lung cancer with mediastinal node involvement. Dense peritracheal fibrosis and sclerosis after chemoradiotherapy cause difficult mediastinal node dissection. We evaluated a novel technique to make the mediastinal node dissection easier after induction therapy. Methods: At the end of mediastinoscopic node biopsy for staging of lung cancer, cotton-type collagen was inserted anterior and lateral to the trachea in patients with pathologically confirmed mediastinal node involve-ment (n=45). The induction therapy consisted of concurrent use of platinum-based chemotherapy and hyperfractionated radiotherapy. After the chemoradiotherapy all patients underwent a pulmonary resection with complete mediastinal node dissection 7–12 weeks after the collagen insertion. Surgical findings of the mediastinum and the time for node dissection were compared with those without collagen insertion at mediastinoscopy after chemoradiotherapy (n=5). Results: All five patients without collagen insertion showed sclerotic and fibrotic change of mediastinal nodes with severe adhesion to the trachea. In 42 of 45 patients with collagen insertion (93.3%) the collagen remained unabsorbed and separated the mediastinal nodes from the trachea. Mediastinal node dissection was easily accomplished by removing mediastinal tissues lateral and anterior to the collagen. The rate of mediastinal node separation was significantly higher with collagen insertion than without (p< 0.0001). The times for node dissection in patients with and without collagen insertion showed no significant difference. Conclusion: Cotton-type collagen insertion at staging mediastinoscopy for lung cancer separates the mediastinal nodes from the trachea and makes the node dissection easier after induction chemoradiotherapy.  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