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   5803篇
  免费   248篇
  国内免费   24篇
耳鼻咽喉   27篇
儿科学   126篇
妇产科学   107篇
基础医学   715篇
口腔科学   63篇
临床医学   344篇
内科学   1453篇
皮肤病学   184篇
神经病学   453篇
特种医学   131篇
外科学   1045篇
综合类   24篇
一般理论   1篇
预防医学   101篇
眼科学   54篇
药学   298篇
中国医学   18篇
肿瘤学   931篇
  2023年   52篇
  2022年   84篇
  2021年   119篇
  2020年   80篇
  2019年   86篇
  2018年   96篇
  2017年   89篇
  2016年   114篇
  2015年   113篇
  2014年   152篇
  2013年   201篇
  2012年   293篇
  2011年   416篇
  2010年   222篇
  2009年   181篇
  2008年   364篇
  2007年   393篇
  2006年   331篇
  2005年   390篇
  2004年   383篇
  2003年   353篇
  2002年   316篇
  2001年   46篇
  2000年   51篇
  1999年   87篇
  1998年   101篇
  1997年   96篇
  1996年   107篇
  1995年   95篇
  1994年   89篇
  1993年   56篇
  1992年   50篇
  1991年   47篇
  1990年   34篇
  1989年   28篇
  1988年   33篇
  1987年   16篇
  1986年   20篇
  1985年   19篇
  1984年   20篇
  1981年   16篇
  1980年   26篇
  1979年   12篇
  1978年   18篇
  1977年   18篇
  1975年   15篇
  1957年   23篇
  1956年   16篇
  1955年   17篇
  1954年   11篇
排序方式: 共有6075条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Background: Ketamine potentiates intravenous or epidural morphine analgesia. The authors hypothesized that very-low-dose ketamine infusion reduces acute and long-term postthoracotomy pain.

Methods: Forty-nine patients scheduled to undergo open thoracotomy were randomly assigned to receive one of two anesthesia regimens: continuous epidural infusion of ropivacaine and morphine, along with intravenous infusion of ketamine (0.05 mg [middle dot] kg-1 [middle dot] h-1 [approximately 3 mg/h], ketamine group, n = 24) or placebo (saline, control group, n = 25). Epidural analgesia was continued for 2 days after surgery, and infusion of ketamine or placebo was continued for 3 days. Pain was assessed at 6, 12, 24, and 48 h after surgery. Patients were asked about their pain, abnormal sensation on the wound, and inconvenience in daily life at 7 days and 1, 3, and 6 months after surgery.

Results: The visual analog scale scores for pain at rest and on coughing 24 and 48 h after thoracotomy were lower in the ketamine group than in the control group (pain at rest, 9 +/- 11 vs. 25 +/- 20 and 9 +/- 11 vs. 18 +/- 13; pain on coughing, 26 +/- 16 vs. 50 +/- 17 and 30 +/- 18 vs. 43 +/- 18, mean +/- SD; P = 0.002 and P = 0.01, P < 0.0001 and P = 0.02, respectively). The numerical rating scale scores for baseline pain 1 and 3 months after thoracotomy were significantly lower in the ketamine group (0.5 [0-4] vs. 2 [0-5] and 0 [0-5] vs. 1.5 [0-6], median [range], respectively; P = 0.02). Three months after surgery, a higher number of control patients were taking pain medication (2 vs. 9; P = 0.03).  相似文献   

5.
Background and Aim: Duodenal lymphangitis carcinomatosa has been sporadically described, but so far little attention has been paid to duodenal lymphangitis carcinomatosa. Methods: Four cases with duodenal lymphangitis carcinomatosa were endoscopically and histologically examined. Results: The four cases exhibited multiple polypoid lesions along the Kerckring's folds and/or were covered by characteristically granular, non‐ulcerated mucosa upon thickening. The granularity seems to been caused by dilated lymph vessels containing the carcinoma cells. The lesions were microscopically characterized by: (i) involvement of lymph vessels located in the upper portion of the lamina propria; (ii) no inflammatory changes; and (iii) no desmoplastic changes. Primary sites were thought to be the stomach in case 1, the pancreas in cases 2 and 4, and unknown in case 3. All patients died within 6 months after admission or endoscopic examination. Conclusions: As duodenal lymphangitis carcinomatosis shows characteristic endoscopic appearance, endoscopic diagnosis is not difficult. We should realize that the lesion represents extremely poor prognosis, and it should be distinguished from ordinary metastatic duodenal carcinoma.  相似文献   
6.
7.
PURPOSE: To determine the effect of an interposition nerve graft on sexual function after radical prostatectomy. METHODS: This study includes 64 patients, without hormonal therapy, who underwent a radical prostatectomy and intraoperative electrophysiological confirmation of cavernous nerve preservation. Twelve patients underwent a unilateral interposition sural nerve graft (UNG) for the resected neurovascular bundle. Twenty-one and 31 patients underwent bilateral nerve-sparing (BNS) and unilateral nerve-sparing (UNS) surgery without a nerve graft, respectively. As the age of patients was significantly younger in the UNG group than in the other groups, age-matched analysis also was conducted. Sexual function, evaluated by a self-administered questionnaire using the University of California Los Angeles-Prostate Cancer Index, was compared statistically among the three groups. RESULTS: In the age-matched analysis, the postoperative sexual function (SXF) score of the UNG group showed an intermediate level of recovery between those of the BNS and UNS groups at 12 months and reached the same level as the score at 12 months of the BNS group at 18 months postoperatively. The difference in the SXF score between the UNG and UNS groups began to appear after 6 months postoperatively and increased steadily with time. However, the background factors, such as the baseline SXF score, the usage rate of phosphodiesterase 5 inhibitors, and the rate of comorbidities were different between the UNG and UNS groups. CONCLUSIONS: The difference of the SXF score between the UNG and UNS groups increased with time after 6 months postoperatively. However, it might be difficult at present to attribute a better recovery of the SXF score to the nerve graft because of the difference in the background factors between the groups.  相似文献   
8.
OBJECTIVE: Standard chemotherapy shows relatively low long-term survival in patients with poor-risk testicular germ cell tumor (GCT). First-line high-dose chemotherapy (HD-CT) may improve the result. High-dose carboplatin, etoposide, ifosfamide chemotherapy followed by autologous peripheral blood stem cell transplantation (PBSCT) was investigated as first-line chemotherapy in patients with advanced testicular GCT. METHODS: Fifty-five previously untreated testicular GCT patients with Indiana 'advanced disease' criteria received three cycles of bleomycin, etoposide and cisplatin (BEP) followed by one cycle of HD-CT plus PBSCT, if elevated serum tumor markers were observed after three cycles of the BEP regimen. RESULTS: Thirty patients were treated with BEP alone, because the tumor marker(s) declined to normal range. Twenty-five patients received BEP and HD-CT. One patient died of rhabdomyolysis due to HD-CT. Three and six (13% and 25%) out of 24 patients treated with BEP and HD-CT achieved marker-negative and marker-positive partial responses, respectively. The other patients achieved no change. Fifteen (63%) are alive and 14 (58%) are free of disease at a median follow-up time of 54 months. Severe toxicity included treatment-related death (4%). CONCLUSIONS: HD-CT with peripheral stem cell support can be successfully applied in a multicenter setting. HD-CT demonstrated modest anticancer activity for Japanese patients with advanced testicular GCT and was well tolerated. This regimen might be examined for further investigation in randomized trials in first-line chemotherapy for patients with poor-risk testicular GCT.  相似文献   
9.
10.
Abstract: Biliobiliary fistula is a rare clinical entity. The case of a 72 year old female, who presented with epigastric pain and jaundice, is detailed herein. Endoscopic retrograde cholangiopancreatography (ERCP) revealed two stones, one each in the common bile duct and the gallbladder. Continuous endoscopic nasobiliary drainage (ENBD) was performed to relieve obstructive jaundice. Further study with contrast medium administered via the ENBD tube revealed a fistula between the neck of the gallbladder and the common bile duct. The cystic duct was intact. A stone was considered to have migrated into the common bile duct through the fistula. A diagnosis of biliobiliary fistula, Corlette type I was made. However, in this particular case, a biliobiliary fistula was noted at a site below the junction of the cystic duct and common bile duct. Removal of the gallbladder stones was followed by cholecystectomy. The common bile duct was then repaired by utilizing a T-tube. No evidence of malignancy was recognized in the resected gallbladder specimen. In the one year to date since surgery, the patient has been asymptomatic and without signs of biliary disease.  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