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   10292篇
  免费   780篇
  国内免费   270篇
耳鼻咽喉   1465篇
儿科学   179篇
妇产科学   52篇
基础医学   887篇
口腔科学   1075篇
临床医学   1157篇
内科学   1770篇
皮肤病学   59篇
神经病学   798篇
特种医学   490篇
外科学   1052篇
综合类   1298篇
现状与发展   1篇
预防医学   112篇
眼科学   173篇
药学   352篇
  6篇
中国医学   107篇
肿瘤学   309篇
  2024年   19篇
  2023年   152篇
  2022年   237篇
  2021年   365篇
  2020年   339篇
  2019年   352篇
  2018年   336篇
  2017年   358篇
  2016年   392篇
  2015年   379篇
  2014年   622篇
  2013年   612篇
  2012年   545篇
  2011年   621篇
  2010年   475篇
  2009年   481篇
  2008年   499篇
  2007年   530篇
  2006年   467篇
  2005年   440篇
  2004年   379篇
  2003年   295篇
  2002年   247篇
  2001年   232篇
  2000年   210篇
  1999年   194篇
  1998年   148篇
  1997年   155篇
  1996年   116篇
  1995年   125篇
  1994年   102篇
  1993年   96篇
  1992年   90篇
  1991年   77篇
  1990年   67篇
  1989年   78篇
  1988年   66篇
  1987年   64篇
  1986年   58篇
  1985年   63篇
  1984年   49篇
  1983年   42篇
  1982年   46篇
  1981年   38篇
  1980年   25篇
  1979年   18篇
  1978年   10篇
  1977年   11篇
  1976年   7篇
  1972年   6篇
排序方式: 共有10000条查询结果,搜索用时 35 毫秒
101.
经血管内栓塞治疗颈外动脉—海绵窦瘘   总被引:2,自引:0,他引:2  
目的:探讨经血管内栓塞治疗3例颈外动脉海绵窦瘘的临床意义。材料和方法:3例颈外动脉海棉窦瘘均经股动脉入路栓塞,采用微螺旋圈和聚乙烯醇颗粒将瘘口闭塞。结果:术后患者临床症状显著改善。随访1个月至1年病情无复发。结论:颅内无血管杂音是其重要体征。将微导管置入瘘口是栓塞成功的关键  相似文献   
102.
颞下窝病变CT MRI诊断   总被引:1,自引:0,他引:1  
本文报告了87例经病理证实颞下窝病变CT或MRI表现,发现该窝病变以继发肿瘤为主(79/87),也可见于炎症(4/87),原发肿瘤少见(4/87)。继发侵犯可来自窝壁各方向,但以鼻咽癌内侧壁、上颌窦癌前壁侵入为主。文内讨论了颞下窝解剖定位及继发侵犯的改变特点,指出横切CT和MRI对观察颞下窝病变具有基本等同诊断作用,并应为首选扫描方位。  相似文献   
103.
Our objective was to establish the age-related 3D size of maxillary, sphenoid, and frontal sinuses. A total of 179 magnetic resonance imaging (MRI) of children under 17 years (76 females, 103 males) were included and sinuses were measured in the three axes. Maxillary sinuses measured at birth (mean+/-standard deviation) 7.3+/-2.7 mm length (or antero-posterior)/4.0+/-0.9 mm height (or cranio-caudal)/2.7+/-0.8 mm width (or transverse). At 16 years old, maxillary sinus measured 38.8+/-3.5 mm/36.3+/-6.2 mm/27.5+/-4.2 mm. Sphenoid sinus pneumatization starts in the third year of life after conversion from red to fatty marrow with mean values of 5.8+/-1.4 mm/8.0+/-2.3 mm/5.8+/-1.0 mm. Pneumatization progresses gradually to reach at 16 years 23.0+/-4.5 mm/22.6+/-5.8 mm/12.8+/-3.1 mm. Frontal sinuses present a wide variation in size and most of the time are not valuable with routine head MRI techniques. They are not aerated before the age of 6 years. Frontal sinuses dimensions at 16 years were 12.8+/-5.0 mm/21.9+/-8.4 mm/24.5+/-13.3 mm. A sinus volume index (SVI) of maxillary and sphenoid sinus was computed using a simplified ellipsoid volume formula, and a table with SVI according to age with percentile variations is proposed for easy clinical application. Percentile curves of maxillary and sphenoid sinuses are presented to provide a basis for objective determination of sinus size and volume during development. These data are applicable to other techniques such as conventional X-ray and CT scan.  相似文献   
104.
目的分析肥厚性硬脑膜炎(HCP)的临床特点,提高对该病的认识。方法对2例特殊的HCP患者的临床资料结合文献进行回顾性分析。结果 2例HCP患者均以头痛起病,其中1例初诊为静脉窦血栓形成,经治疗未见好转;另1例逐渐出现面神经麻痹和硬膜下积液,综合分析临床特点、影像学之后,最终确诊为HCP。经激素治疗后取得良好疗效。结论 HCP患者可发生静脉窦血栓形成和硬膜下积液。HCP少见,临床缺乏特征性,易被漏诊、误诊,应引起临床医生重视。  相似文献   
105.
目的:了解胆道术后不同时期T管窦道的结构特点并探讨其临床意义.方法:选择胆总管切开探查T管引流术病人.术中测量胆道压力及术后测量胆道压力和T管窦道的牢固性;检查拔T管后胆瘘的位置;对术后行纤维胆道镜检查者,测量T管窦道的长度和宽度,取部分窦道壁组织进行病理检查;对再次手术者,术中形成窦道,术后对窦道壁进行病理检查.结果:T管窦道的长度为(6.3±4.1) cm,宽度为(0.74±0.09) cm,厚度及牢固性术后不同时期各不相同,并受一些因素影响,窦道与胆总管和腹壁连接处较薄弱.结论:T管窦道有其本身的结构特点,了解T管窦道的结构特点对术后胆汁漏的防治以及选择时期经T管窦道行胆道内的各种检查和治疗有意义.  相似文献   
106.
患者,女,30岁。5年前发现右侧额部头皮有一黄豆大结节,质软,无压痛、头痛及头皮周围软组织触痛,无发热、头昏、恶心、呕吐,无视物模糊、肢体麻木。一直未予重视。3个月前无明显诱因下感肿块逐渐增大,约鸡蛋大小。体格检查:精神反应正常,问答切题。心肺听诊无异常。右侧额部可见一大小约4cm×3cm头皮肿块,基底宽,肿块边界尚清,活动度差,质韧,顶部偏软,顶部无压痛,周边轻压痛,局部头皮无红肿、破溃,毛发无脱落,无血管扩张,未闻及血管杂音,皮温无殊。耳前、颌下及颈部等全身浅表淋巴结未及肿大。实验室检查:血、尿、便常规及肝功能正常。影像学表现:头颅CT示右侧额部头皮下见一大小约3.2cm×4.3cm宽基底的软组织肿块影,边缘清楚,密度较均匀,CT值约27.8HU,局部颅骨见不规则孔状骨质破坏,边界较清楚,未见明显硬化缘,局部头皮下脂肪层受压变薄(图1a-1d)。MRI示右侧额骨局  相似文献   
107.
目的:采用尿生殖窦植入法建立大鼠良性前列腺增生模型并进行组织形态学半定量及免疫组化研究。方法:7周龄雄性SD大鼠32只,随机分为4组:假手术对照组,尿生殖窦模型2周组,尿生殖窦模型3周组,尿生殖窦模型6周组。尿生殖窦植入各模型组大鼠,分别饲养指定周期后,分离各组大鼠前列腺组织,测量湿重及体积,右侧前列腺腹前叶切片并进行半定量组织形态学测量,采用免疫组化法检测上皮、间质、平滑肌中相关表达因子。结果:各模型组大鼠右侧前列腺腹叶湿重及指数、体积及指数随模型培养时间延长而增加(P<0.05),间质面积比例、间质相对总体积随时间延长显著增加(P<0.01),3周模型组的间质平均比例高达75.32%;模型组上皮相对总体积随时间延长亦增加。与假手术对照组相比,腺腔面积、上皮面积比例,腺腔面积比例减少。广谱细胞角蛋白免疫组化染色阳性颗粒定位于上皮细胞,波形蛋白于间质细胞丰富表达,平滑肌肌动蛋白于腺腔周围表达。结论:大鼠尿生殖窦良性前列腺增生模型以间质增生为主,相关因子表达部位与人类良性前列腺增生相似。  相似文献   
108.
Aim With the introduction of single‐port surgery, expected advantages are improved cosmesis, decrease of pain and shorter length of stay. The aim of this study was to compare early outcomes of single‐port colectomy with those of conventional laparoscopic colectomy. Method All consecutive patients undergoing single‐port colectomy between January and June 2010 were identified from a prospective database. They were matched for age, sex, body mass index, American Society of Anesthesiology score and type of resection with patients who had conventional laparoscopic colectomy. All perioperative data, analgesic requirement, pain scores and inflammatory response were compared using the Wilcoxon signed‐rank and McNemar tests. Results Fourteen patients [five men, nine women; median age (interquartile range) 56 (30–73) years, body mass index (interquartile range) 22 (20–24) kg/m2] underwent single‐port colectomy and were matched with patients who had conventional laparoscopic colectomy. Median operating times, estimated blood loss, pain scores, analgesic requirement, inflammatory response and length of hospital stay were similar. Median increase in incision length was significantly higher in the single‐port group (P = 0.004), but maximal incision length for specimen extraction was comparable. There were no anastomotic leaks, wound infections or 30‐day readmissions. Conclusion In a case‐matched setting with a small sample size, single‐port laparoscopic colectomy has comparable outcomes to conventional laparoscopic colectomy.  相似文献   
109.
ObjectiveNew-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.MethodsWe performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.ResultsPOAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).ConclusionsThe results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established.  相似文献   
110.
ObjectiveThe objective of this study was to investigate the association between morphological variation and postsurgical pulmonary vein (PV) stenosis (PPVS) in patients with cardiac total anomalous pulmonary venous connection (TAPVC).MethodsThis single-center, retrospective study included 168 pediatric patients who underwent surgical repair of cardiac TAPVC from 2013 to 2019 (connection to the coronary sinus [CS], n = 136; connection directly to the right atrium [RA], n = 32). Three-dimensional computed tomography modeling and geometric analysis were performed to investigate the morphological features; their relevance to the PPVS was examined.ResultsThe connection type had no association with PPVS (CS type: 18% vs right atrial type: 19%; P = .89) but there was a higher incidence of PPVS in patients with a single PV orifice than > 1 orifice (P < .001). Confluence-to-total PV area ratio (hazard ratio, 4.78, 95% CI, 1.86-12.32; P = .001) and length of drainage route (hazard ratio, 1.22; 95% CI, 1.14-1.31; P < .001) had a 4- and 1-fold increase in the risk for PPVS in the CS type after adjustment for age and preoperative pulmonary venous obstruction. In the right atrial type, those with anomalous PV return to the RA roof were more likely to develop PPVS than to the posterior wall of the RA (P < .001).ConclusionsThe number of inter-junction PV orifice correlated with PPVS development in cardiac TAPVC. The confluence-to-total PV ratio, length of drainage route, and anomalous PV return to the RA roof are important predictors for PPVS. Morphological subcategorization in this clinical setting can potentially assist in surgical decision-making.  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