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   15643篇
  免费   1011篇
  国内免费   680篇
耳鼻咽喉   522篇
儿科学   188篇
妇产科学   52篇
基础医学   447篇
口腔科学   82篇
临床医学   2083篇
内科学   4766篇
皮肤病学   66篇
神经病学   202篇
特种医学   1026篇
外国民族医学   2篇
外科学   3036篇
综合类   2576篇
预防医学   531篇
眼科学   69篇
药学   1108篇
  21篇
中国医学   208篇
肿瘤学   349篇
  2024年   34篇
  2023年   291篇
  2022年   623篇
  2021年   710篇
  2020年   711篇
  2019年   519篇
  2018年   554篇
  2017年   566篇
  2016年   654篇
  2015年   645篇
  2014年   1275篇
  2013年   1261篇
  2012年   1133篇
  2011年   1066篇
  2010年   859篇
  2009年   803篇
  2008年   854篇
  2007年   799篇
  2006年   660篇
  2005年   572篇
  2004年   458篇
  2003年   342篇
  2002年   278篇
  2001年   242篇
  2000年   191篇
  1999年   145篇
  1998年   149篇
  1997年   133篇
  1996年   107篇
  1995年   99篇
  1994年   89篇
  1993年   71篇
  1992年   61篇
  1991年   61篇
  1990年   53篇
  1989年   38篇
  1988年   46篇
  1987年   44篇
  1986年   21篇
  1985年   22篇
  1984年   12篇
  1983年   15篇
  1982年   24篇
  1981年   11篇
  1980年   11篇
  1979年   6篇
  1978年   2篇
  1977年   11篇
  1972年   3篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
81.
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   
82.
Flexible tantalum stents (Strecker) were used as an adjunct to percutaneous transluminal angioplasty (PTA) in the treatment of stenotic arterial or venous limbs of Brescia-Cimino hemodialysis fistulas. The diagnostic procedure was performed using retrograde fistulography. After PTA with unsatisfactory results, stents were placed in 5 patients with significant residual stenoses and poor fistula function. Within the mean follow-up period of 6.4 months (range 3–10 months) all fistulas were functioning. We conclude that Strecker stent is useful in the treatment of stenotic hemodialysis arteriovenous fistulas as an adjunct to PTA.  相似文献   
83.
One hundred and ten patients with common bile duct (CBD) stones were treated in the Department of Surgical Gastroenterology at SGPGIMS, Lucknow, India between January 1989 and December 1992. The primary modality of treatment was surgery in 62 patients (group I) and endoscopic sphincterotomy (ES) in 48 (group II). The two groups were well matched with respect to clinical features and presence of medical risk factors. Surgical clearance of CBD stones was achieved in 58 patients (93.5%; group Ia). Four patients (7%) had retained stones following surgery (group Ib). In group II, the CBD was cleared by endoscopic means in 20 out of 48 patients (42%) and was categorized into group IIa. In the remaining patients ES was followed by CBD exploration (group IIb). Significantly higher morbidity was seen in patients needing CBD surgery following attempted endoscopic clearance, because of ES-related complications, such as bleeding, cholangitis, septicaemia and numerous others. Use of ES to treat CBD stones on a routine basis was therefore not found to be any better than one-time surgical exploration.  相似文献   
84.
目的比较经皮椎体成形术与椎体后凸成形术治疗胸腰椎压缩性骨折的临床疗效。方法对98例胸腰椎压缩性骨折,根据手术方法不同分为椎体成形组和椎体后凸成形组。比较两组术前术后椎体前缘、中线、后缘高度变化,疼痛视觉模糊评分(VAS),手术时间,出血量等方面的差异。结果两组对椎体高度的恢复比较差异有统计学意义(P〈0.01),VAS、手术时间和出血量比较差异无统计学意义(P〉0.05)。结论经皮椎体成形术与椎体后凸成形术具有创伤小、手术时间短、出血量少等微创优点,而椎体后凸成形术具有较好的复位作用。  相似文献   
85.
A case history of a 32-year-old female Olympic pole vaulter is reported. Two months after endoscopic surgery for chronic Achilles tendinopathy, she developed a keloid lesion on the hindfoot area. She was treated with corticosteroids, topical and intralesional injections. A satisfactory result was obtained, and the athlete was able to resume her competitive activity at 5 months after surgery. Keloid pathogenesis, treatment, and prevention are briefly discussed.  相似文献   
86.
Objective: To evaluate the role of gastrointestinal (GI) endoscopy in human immunodeficiency virus (HIV)‐infected children with GI problems. Methods: From 1998 to 2002, we retrospectively reviewed all cases of HIV‐infected children presenting with GI problems in which an upper or lower GI endoscopy was indicated. The initial diagnostic endoscopic examination and any repeat endoscopic session leading to a new diagnosis were used in the data analysis. Tissue biopsies were obtained from all abnormal lesions and representative sites of normal‐appearancing GI mucosa. Results: Fourteen patients (median age: 22.5 months) underwent 23 sessions of GI endoscopy, including 10 esophagogastroduodenoscopy, nine colonoscopy and four flexible sigmoidoscopy. Chronic diarrhea was the most common indication, followed by lower GI bleeding, abdominal/retrosternal pain, dysphagia/odynophagia, and upper GI bleeding. Gross endoscopic abnormalities were observed in 78.3%; whereas histological inflammation and opportunistic pathogens were identified in 87% and 43.5%, respectively. Cytomegalovirus was the most common identified pathogen. Abnormal gross findings were significantly associated with histological inflammation and identification of pathogens (P = 0.006 and 0.046, respectively). Specific changes in medical management were made in 50% of cases as a result of endoscopic investigation. Conclusion: If non‐invasive investigations for HIV‐infected children with GI symptoms fail to establish a diagnosis, gastrointestinal endoscopy should be performed and often yields a positive result leading to changes in medical management.  相似文献   
87.
目的评价影像设备引导下,经皮穿刺与经支气管填塞,治疗耐多药肺结核空洞的临床疗效。方法CR、CT及生化,病理学确诊的耐多药肺结核空洞患者88例,用经皮穿刺治疗44例(A组)和经支气管填塞治疗44例(B组)。并对照分析其方法,并发症和疗效,评估其应用价值。结果A组闭塞性空洞愈合14例(32%)、净化性空洞愈合16例(36%),无变化及轻微缩小14例(32%),总治愈率为68%;B组闭塞性空洞愈合23例(52.27%),净化空洞愈合17例(38.64%),无变化及轻微变小4例(9%),总治愈率达91%。B组比A组总疗效高出23%(91%~68%),并发症低,疗程缩短1~2个月。结论支气管填塞治疗耐多药肺结核空洞的疗效要优于经皮穿刺的方法。是目前治疗耐多药肺结核空洞的比较有效方法。  相似文献   
88.
目的 观察X线电视引导下经皮穿刺腰椎间盘切吸术治疗腰椎间盘突出症的远期疗效。方法 32例经CT扫描证实的腰椎间盘突出症患者,其中,膨出型29例,游离型2例,以及突出型1例,均经X线电视引导下经皮穿刺腰椎间盘切吸术治疗,术后均经随访0.5~11.0a。结果 术后1周~3个月,32例中的24例临床症状与体征得到有效控制或明显减轻,随访5~11a观察表明,症状完全消失和明显减轻者分别见于23例和6例,总有效率90.6%,预后极好和较好者均见于膨出型腰椎间盘突出症患者。结论 游离型和突出型腰椎间盘突出症的疗效均不理想,因此,术前认真选择适应证是获得理想疗效的关键性因素。  相似文献   
89.
经皮胆囊碎石术后结石复发439例随访分析   总被引:1,自引:0,他引:1  
目的探讨经皮胆囊碎石术(PCCL)后长期临床预后和结石复发情况,了解与结石复发的相关因素。方法对439例PCCL患者随访10年,评估结石复发率和临床预后。结果439例患者中182例结石复发,总复发率41.46%,术后1~10年结石累计复发率分别为9·57%、18·91%、27·33%、34·14%、37·59%、39·86%、41·90%、42·73%、42·85%和43·21%。182例结石复发患者中,94例无症状,80例表现有非特异性上消化道不适症状,8例有上腹痛或胆绞痛,其中38例行胆囊切除术治疗。与结石复发相关的因素包括胆囊结石家族史、喜好油腻食品、伴发肝病、PCCL术前复发胆囊结石和胆囊功能不全。结论PCCL术后结石复发不可避免,术后前6年结石复发率逐年增加明显,随后增长缓慢,术后10年约50%的患者无结石复发。一些危险因素与结石复发有关。PCCL可作为高龄和高危胆囊结石患者有价值的治疗选择,治疗其他胆囊结石患者尚需慎重选择。  相似文献   
90.
OBJECTIVE: Pediatric gastric access for long-term enteral feeding may be performed via a laparotomy, laparoscopy, or a percutaneous approach. In children and adolescents, laparoscopic-assisted gastrostomy may be difficult due to a thick abdominal wall. Therefore, if the abdominal wall is estimated to be >2 cm on physical examination, or in children in whom a percutaneous endoscopic gastrostomy was unsuccessfully attempted by a gastroenterologist, we routinely perform a laparoscopic-assisted percutaneous endoscopic gastrostomy. METHODS: From January 1998 through February 2003, we retrospectively reviewed 15 cases of a laparoscopic-assisted percutaneous endoscopic gastrostomy. Instruments used to perform this technique are a percutaneous endoscopic gastrostomy kit, an Olympus flexible endoscope, and one 5-mm STEP port placed through an infraumbilical incision for a 5-mm, 30-degree scope. RESULTS: Age range was 2 years to 20 years (mean, 10). Operative time ranged from 20 minutes to 45 minutes. When a concurrent laparoscopic Nissen fundoplication was performed (n = 6), the percutaneous endoscopic gastrostomy was placed after completion of the Nissen fundoplication. No intraoperative complications occurred, and all tubes were successfully placed. Feeds were instituted the following day and advanced to goal. To date, no postoperative complications have occurred, and revision has not been necessary. CONCLUSIONS: Laparoscopic-assisted percutaneous endoscopic gastrostomy in children and adolescents is safe and effective. Utilizing laparoscopy permits evaluation of the peritoneum and lysis of adhesions, if necessary. Moreover, laparoscopy provides excellent exposure for accurate placement of the PEG, while avoiding injury to other organs.  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