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   48429篇
  免费   4697篇
  国内免费   3655篇
耳鼻咽喉   314篇
儿科学   449篇
妇产科学   495篇
基础医学   5738篇
口腔科学   765篇
临床医学   7006篇
内科学   7435篇
皮肤病学   604篇
神经病学   2644篇
特种医学   1956篇
外国民族医学   23篇
外科学   4478篇
综合类   7921篇
现状与发展   15篇
一般理论   7篇
预防医学   2926篇
眼科学   1486篇
药学   5168篇
  92篇
中国医学   2948篇
肿瘤学   4311篇
  2024年   134篇
  2023年   805篇
  2022年   1833篇
  2021年   2754篇
  2020年   2062篇
  2019年   1704篇
  2018年   1816篇
  2017年   1569篇
  2016年   1516篇
  2015年   2253篇
  2014年   2729篇
  2013年   2410篇
  2012年   3545篇
  2011年   3977篇
  2010年   2432篇
  2009年   1897篇
  2008年   2526篇
  2007年   2602篇
  2006年   2514篇
  2005年   2582篇
  2004年   1497篇
  2003年   1348篇
  2002年   1129篇
  2001年   1107篇
  2000年   1162篇
  1999年   1214篇
  1998年   789篇
  1997年   800篇
  1996年   623篇
  1995年   570篇
  1994年   515篇
  1993年   305篇
  1992年   383篇
  1991年   309篇
  1990年   284篇
  1989年   245篇
  1988年   232篇
  1987年   203篇
  1986年   151篇
  1985年   110篇
  1984年   50篇
  1983年   38篇
  1982年   19篇
  1981年   12篇
  1980年   13篇
  1979年   12篇
  1966年   1篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
1.
ObjectiveEach pulmonary segment is an anatomical and functional unit. However, it is fundamentally difficult to precisely distinguish every pulmonary segment using the conventional pulmonary intersegmental planes from computed tomography images. Building arteriopulmonary segments is likely to be an effective way to identify pulmonary segments.MethodsThe thoracic computed tomography images of 40 patients were collected. The anatomic structures of interest were extracted in the transverse, sagittal, and coronal planes using the semi-automated segmentation tools provided by Amira software. The intrapulmonary vessels were subsequently segmented and reconstructed. The distributions of the pulmonary arteries, veins, and bronchi were observed. In patients with pulmonary masses, the mass was also reconstructed.ResultsThe three-dimensional reconstructed images showed the branches of the pulmonary artery ramified up to their eighth order covering the entire lung as well as evident intersegmental gaps without pulmonary arteries. The segmental artery was closely accompanied by the segmental bronchi in 486 pulmonary segments (90% of total number of segments). The size and spatial location of the pulmonary mass within a pulmonary segment were also clearly visible.ConclusionsDemarcation of arteriopulmonary segments can be used to precisely distinguish every pulmonary segment and provide its detailed anatomical structure before pulmonary segmentectomy.  相似文献   
2.
“三全育人”是高校思政教育工作的关键一环,也是中医药高校推动思政教育的重要内容。以“三全育人”为视角对北京中医药大学思想政治教育举措“杏林成长导师”计划路径、内容深入分析,运用统计分析和文献研究方法,剖析该计划对中医学专业大学生的学业、思想和实践等多个层面的现实成效,从而为“三全育人”理念在中医药院校制度建构中的应用提供新的视角与方法。  相似文献   
3.
4.
Inappropriate use of acetaminophen (APAP) can lead to morbidity and mortality secondary to hepatic necrosis. Ginsenoside Rg1 is a major active ingredient in processed Panax ginseng, which is proved to elicit biological effects. We hypothesized the beneficial effect of Rg1 on APAP-mediated hepatotoxicity was through Nrf2/ARE pathway. The study was conducted in cells and mice, comparing the actions of Rg1. Rg1 significantly improved cell survival rates and promoted the expression of antioxidant proteins. Meanwhile, Rg1 reduced the excessive ROS and the occurrence of cell apoptosis, which were related to Nrf2/ARE pathway. Expression of Nrf2 has a certain cell specificity.

  相似文献   

5.
目的:探讨电视胸腔镜(VATS)解剖性肺段切除术与肺叶切除术治疗Ia 期非小细胞肺癌(NSCLC)患者的手术情况及对患者肺功能的影响。方法:选取我院手术治疗的Ⅰa期NSCLC患者,收集时间2014年1月至2016年12月,根据术式不同分为两组,均采用VATS手术治疗,A组(54例)患者采用解剖性肺段切除术、B组(60例)采用肺叶切除术治疗,对比两组患者的手术效果及术后肺功能变化。结果:A组患者的手术时间、清扫淋巴结数目与B组比较差异无统计学意义(P>0.05);A组患者的手术出血量、术后胸腔引流量、术后拔管时间、术后住院时间均显著的低于B组患者(P<0.05);术前,A组和B组患者的FEV1%、FVC%、MVV%测定值差异无统计学意义(P>0.05),术后3个月复查,A组患者的FEV1%、FVC%、MVV%测定值均显著高于B组患者(P<0.05);手术后,A组患者的并发症发生率(7.41%)低于B组患者(13.33%),但是差异无统计学意义(P>0.05)。结论:VATS解剖性肺段切除术治疗Ⅰa期NSCLC患者具有手术创伤小、术后恢复快、对患者肺功能影响更小的优势。  相似文献   
6.
目的:观察非霍奇金淋巴瘤(non-Hodgkin's lymphoma,NHL)患者自体造血干细胞移植(autologous hematopoietic stem cell transplantation,ASCT)术后应用重组人α-2b干扰素(α-2b IFN)进行早期干预治疗的临床疗效。方法:选取18例行ASCT的NHL患者为研究对象,移植前疾病评估均未达到完全缓解(complete remission,CR),试验组血象恢复后给予IFN 3 000 000 U次/隔日干预治疗,3个月后停用;对照组未行干扰素干预治疗,分析总体疗效及两组对比的生存情况。结果:随访中位时间为34(10~50)个月,患者中位生存时间为37(31~45)个月,3年总体无进展生存(progressive free survival,PFS)、总生存(overall survivial,OS)分别为54.7%、66.8%。ASCT后试验组1年内无疾病复发,2年内复发率为12.5%;对照组1年内复发率为20%,2年内复发率为30%。结论:NHL患者在ASCT后给予重组人α-2b IFN早期干预治疗,患者耐受性好,可能降低移植后早期复发率。  相似文献   
7.
BackgroundDual antiplatelet therapy (DAPT) is the cornerstone treatment of acute myocardial infarction (AMI).ObjectiveThe present study aimed to investigate the efficacy and safety of triple antiplatelet therapy (TAPT) in elderly female patients with diabetes and ST segment elevation myocardial infarction (STEMI), who had undergone percutaneous coronary intervention (PCI).MethodsWe designed a randomized, single-blind study. Control group A (97 elderly male patients with diabetes and STEMI, whose CRUSADE scores were < 30) received aspirin, ticagrelor, and tirofiban. A total of 162 elderly female patients with diabetes and STEMI were randomly divided into two groups according to CRUSADE score. Group B (69 patients with CRUSADE score > 31) received aspirin and ticagrelor. Group C (93 patients with CRUSADE score < 30) received aspirin, ticagrelor and tirofiban. P values < 0.05 were considered statistically significant.ResultsCompared to the findings in group A, post-PCI Thrombolysis in Myocardial Infarction (TIMI) grade 3 blood flow and TIMI myocardial perfusion grade 3 were significantly less prevalent in group B (p < 0.05). When compared to groups A and C, the incidence of major adverse complications was significantly higher in group B (p < 0.05).ConclusionTAPT could effectively reduce the incidence of major complications in elderly female patients with diabetes and STEMI. However, close attention should be paid to hemorrhage in patients receiving TAPT. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)  相似文献   
8.
皮肤损伤后的异常愈合会导致病理性瘢痕的产生。病理性瘢痕的出现不仅影响美观,严重时还会造成心理和生理功能障碍。病理性瘢痕的机制研究对于瘢痕治疗有极为重要的意义。其中,动物瘢痕模型是目前研究病理性瘢痕的重要模型手段之一。理想的动物瘢痕模型应该在组织学、细胞学等层面尽可能接近于人类的病理性瘢痕。该文分别从传统技术动物瘢痕中的啮齿类动物模型、兔耳模型和猪模型,以及新技术动物瘢痕模型这两个方面,结合近年来在瘢痕领域应用较多的研究,进行了相应系统的阐述。  相似文献   
9.
This study investigated the hypocholesterolaemic effects of bitter melon aqueous extracts (BMAE) in vitro, the inhibitory effects of BMAE on pancreatic cholesterol esterase (CEase) and incorporation of cholesterol into micelles were investigated. BMAE decreased the in vitro micellar solubility of cholesterol in a dose-dependent manner. The conformation of CEase was investigated by means of circular dichroism (CD) and fluorescence. The result revealed the decrease of α-helix contents, increase of β-sheet and exposure of aromatic amino acid residuals. The incorporation of cholesterol into micelles was inhibited by BMAE. A complex was observed by transmission electron microscopy (TEM), which indicated interaction between cholesterol and BMAE. The result revealed that BMAE can play a role in decreased intestinal cholesterol absorption via inhibition of CEase, and of micelle formation.  相似文献   
10.
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