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   13837篇
  免费   1208篇
  国内免费   1173篇
耳鼻咽喉   1141篇
儿科学   277篇
妇产科学   194篇
基础医学   1931篇
口腔科学   120篇
临床医学   1629篇
内科学   4212篇
皮肤病学   28篇
神经病学   304篇
特种医学   345篇
外国民族医学   2篇
外科学   2385篇
综合类   1520篇
预防医学   357篇
眼科学   117篇
药学   544篇
  6篇
中国医学   69篇
肿瘤学   1037篇
  2024年   32篇
  2023年   326篇
  2022年   618篇
  2021年   755篇
  2020年   699篇
  2019年   644篇
  2018年   585篇
  2017年   478篇
  2016年   652篇
  2015年   700篇
  2014年   1164篇
  2013年   1037篇
  2012年   832篇
  2011年   888篇
  2010年   768篇
  2009年   710篇
  2008年   691篇
  2007年   670篇
  2006年   535篇
  2005年   463篇
  2004年   395篇
  2003年   339篇
  2002年   290篇
  2001年   253篇
  2000年   147篇
  1999年   153篇
  1998年   188篇
  1997年   168篇
  1996年   150篇
  1995年   124篇
  1994年   105篇
  1993年   89篇
  1992年   67篇
  1991年   79篇
  1990年   70篇
  1989年   64篇
  1988年   56篇
  1987年   49篇
  1986年   56篇
  1985年   26篇
  1984年   25篇
  1983年   16篇
  1982年   12篇
  1981年   14篇
  1980年   10篇
  1979年   5篇
  1978年   10篇
  1977年   5篇
  1976年   2篇
  1973年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Carcinoma of the papilla of Vater is classified as periampullary cancer representing 5% of all gastrointestinal tract malignancies. Early and accurate diagnosis is important for those patients with a tumor of the papilla, as the prognosis is more favorable than in other periampullary neoplasms. Endoscopically obtained biopsies from suspicious papillae can detect an early tumor, although even for skilled pathologists it is often difficult to differentiate carcinomas from noninvasive lesions on the basis of forceps biopsies. The purpose of this study was to assess the preoperative diagnostic accuracy of duodenoscopy appearance and biopsy in all cases with suspicion of tumor. Thirty patients with suspicion of carcinoma of the papilla of Vater and with final diagnosis established by pancreatoduodenectomy were included in this retrospective study. In each case, a comparison was made between endoscopic biopsy and duodenoscopic appearance. Duodenoscopic appearance sensitivity and accuracy for malignancy were 86% and 83%, respectively, whereas endoscopic biopsy sensitivity and accuracy were 65% and 67%, respectively. Although preoperative diagnosis of carcinoma of the papilla of Vater is useful for making therapeutic decisions, the diagnostic value of the endoscopic appearance was superior to endoscopic biopsy in this series. Presented at the 2003 American Hepato-Pancreato-Biliary Association Congress, Miami, Florida, February 27-March 3, 2003. Supported by FADA-CAPES/PROP 200J (M.L.D.).  相似文献   
72.
机械通气病人吸痰吸引负压研究现状   总被引:1,自引:0,他引:1  
蒋丰亦 《护理研究》2006,20(5):387-388
介绍了国内外机械通气病人吸痰时吸引负压的选择。提示护士在机械通气病人护理过程中应根据病人的具体情况合理选择。  相似文献   
73.
内镜黏膜下剥离术治疗直肠类癌   总被引:22,自引:1,他引:21  
目的探讨内镜黏膜下剥离术(ESD)治疗直肠类癌的应用价值。方法肠镜发现直肠黏膜下肿块后进行微探头超声检查,对诊断为类癌者应用头端弯曲的针形切开刀进行内镜黏膜下剥离术治疗:(1)黏膜下注射生理盐水抬高病灶,使病灶与肌层分离;(2)预切开病灶周围黏膜;(3)剥离病变下方黏膜下层结缔组织,完整切除病灶。结果5例直肠类癌患者,肿瘤直径0.4~1.2(平均1.1)cm,均成功完成ESD治疗。ESD手术时间(自黏膜下注射至完整剥离病变)20-45(平均35)min;术中创面少量出血,均经电凝、氩离子血浆凝固和止血夹成功止血。不需再次肠镜下止血。1例剥离深至肌层,出现皮下气肿,保守治疗好转。术后全部经病理确诊。基底和切缘未见病变累及。1个月后肠镜复查,创面基本愈合。结论ESD是治疗直肠类癌的新方法.以往需要外科手术切除的肿瘤通过ESD可以达到同样的治疗效果。  相似文献   
74.
解剖因素致单纯鼻源性头痛的鼻内镜手术   总被引:2,自引:0,他引:2  
目的 :探讨鼻内镜手术治疗解剖因素致单纯鼻源性头痛的方法和疗效。方法 :鼻内镜下切除或矫正鼻腔鼻窦区异常解剖结构。结果 :单一因素中鼻丘气房肥大 ,泡性中、上鼻甲及中隔偏曲分别为 7例、10例、12例 ,术后治愈率达 71.4 3%、6 0 .0 0 %、6 6 .6 7% ,合计治愈率达 6 5 .5 2 %。多因素者 4 4例 ,术后治愈率达38.6 4% ,与单一因素差异有显著性 (P <0 .0 2 5 )。患者治疗有效率达 10 0 %。结论 :鼻内镜手术是治疗解剖因素致单纯鼻源性头痛的有效方法之一 ,单一因素者疗效更佳。  相似文献   
75.
Standard imaging techniques using a curved linear array echoendocope are summarized to facilitate the attainment of expertise in endoscopic ultrasonography and endoscopic ultrasound‐guided fine needle aspiration, and to promote the widespread use of this diagnostic and therapeutic tool. Typical images of the mediastinal organs, the bilio‐pancreatic systems and neighboring organs by scanning from the esophagus, stomach, duodenal bulb, and descending portion of the duodenum, are shown in a sequential manner. The basic techniques of endoscopic ultrasound‐guided fine needle aspiration are also presented.  相似文献   
76.
One hundred and fifteen patients, between 6 months and 12 years of age, had bronchoscopy on suspicion of foreign body aspiration. The histories of these patients were studied to examine the diagnostic value of signs, symptoms and examinations, and to determine the time that passed between aspiration and removal of the foreign body. The sensitivity of the symptoms choking and coughing was fairly high (81 and 78%), but the specificity was poor. The sensitivity of a chest radiograph was 82%, the specificity 44%. The sensitivity of radiographs on inspiration and expiration was 80%, the specificity 55%. The patients had been referred with the initial diagnosis foreign body aspiration (80), pneumonia (34), or subglottic laryngitis (1). In 85 patients a foreign body was identified and extracted. The other 30 patients had respiratory tract infections. The initial diagnosis of foreign body aspiration was correct in 61 out of 85 patients. In these cases, the period between aspiration and extraction of the foreign body was a mean 6 days, compared with 55 days, if the initial diagnosis was pneumonia or sub-glottic laryngitis. We conclude that the diagnosis of foreign body aspiration is too often missed, and that, apart from bronchoscopy, diagnostic tools are of little value.  相似文献   
77.
Laparoscopic colposuspension is one of many new operations for treating female urinary stress incontinence. With initially reported success rates similar to those of the traditional open procedure, it appears to combine the advantages of laparoscopy (such as minimal invasiveness and quicker return to normal activities) with the effectiveness of the standard procedure. Different methods and approaches are used, but endoscopic suture techniques remain difficult and time-consuming. The use of endostapling devices for fixation of alloplastic material has been a tempting alternative. We present a case during which laparoscopic colposuspension was performed using staples and mesh. Incontinence did not improve, and the patient suffered severe chronic pain for 18 months postoperatively. Removal of the alloplastic material and traditional abdominal resuspension led to complete cure.  相似文献   
78.
目的:研究内镜Nd:YAG激光治疗食管和贲门早期表浅癌的远期疗效和DNA及p53表达与预后的关系。方法:对内镜激光治疗癌细胞消失的32例食管和贲门早期表浅癌病人进行33~78个月(平均55.3个月)的随访。并与117例早期食管癌和贲门癌的自然病程对比分析。应用ProductLimitEstimate方法计算其存活率。应用免疫组化染色法检测p53表达。应用分光光度计测定癌细胞DNA含量。结果:内镜激光治疗5年存活率为97%,自然病程5年存活率为67%(P<0.01)。p53阳性表达和DNA非整倍体型病人的复发率分别为76.9%和64.3%。结论:内镜Nd:YAG激光是治疗食管和贲门早期表浅癌的有效方法。抗癌基因p53和DNA倍体数与病人的预后有关。  相似文献   
79.
Two-step endoscopic resection of gastric leiomyomas   总被引:2,自引:0,他引:2  
Summary Our two-step technique for endoscopic treatment of gastric leiomyomas is illustrated. From January 1979 to June 1991, nine symptomatic patients with sessile leiomyomas of the stomach were treated at the Endoscopy Division of Istituto Nazionale Tumori, Milan.The diagnosis was achieved by means of endoscopic observation of the lesion and, when possible, by ultrasound endoscopy.This new technique consists of first removing superficial portion of the tumor by electrosurgical snare. Second, a cleavage plane is found within the proper muscle layer; the tumor is enucleated as much as possible by tightening the snare around it and creating a pseudo-stalk. No major complication occurred nor were any recurrences observed at 21.8 months in the 7/9 patients treated by endoscopy alone. Endoscopic therapy was performed on an outpatient basis and only large lesions required short hospitalization.  相似文献   
80.
目的比较基底节脑出血开颅手术治疗与钻颅抽吸治疗的有效性与安全性。方法回顾性分析我院近5年来基底节出血行外科开颅治疗和钻颅抽吸治疗的所有病例,应用统计学方法进行疗效比较。结果共136例基底节出血病例,其中30例行外科开颅清除血肿治疗,106例行钻颅抽吸治疗。两组病例在年龄、出血量、意识状态等预后影响因素方面差异无统计学意义(P〉0.05)。基底节出血开颅手术治疗有效性与安全性与钻颅抽吸治疗相比差异无统计学意义(P〉0.05)。结论基底节出血外科开颅治疗有效性与安全性并不优于钻颅抽吸治疗。  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