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   5382篇
  免费   606篇
  国内免费   168篇
耳鼻咽喉   55篇
儿科学   218篇
妇产科学   135篇
基础医学   106篇
口腔科学   78篇
临床医学   1226篇
内科学   1254篇
皮肤病学   113篇
神经病学   300篇
特种医学   186篇
外科学   1576篇
综合类   11篇
预防医学   316篇
眼科学   326篇
药学   41篇
肿瘤学   215篇
  2023年   106篇
  2021年   62篇
  2020年   96篇
  2019年   40篇
  2018年   124篇
  2017年   170篇
  2016年   180篇
  2015年   134篇
  2014年   221篇
  2013年   294篇
  2012年   85篇
  2011年   107篇
  2010年   226篇
  2009年   333篇
  2008年   114篇
  2007年   60篇
  2006年   98篇
  2005年   67篇
  2003年   44篇
  2001年   105篇
  2000年   68篇
  1999年   133篇
  1998年   175篇
  1997年   199篇
  1996年   301篇
  1995年   257篇
  1994年   195篇
  1993年   116篇
  1992年   130篇
  1991年   134篇
  1990年   70篇
  1989年   133篇
  1988年   102篇
  1987年   80篇
  1986年   100篇
  1985年   84篇
  1984年   87篇
  1983年   74篇
  1982年   66篇
  1981年   62篇
  1980年   80篇
  1979年   39篇
  1978年   60篇
  1977年   42篇
  1976年   43篇
  1975年   46篇
  1972年   38篇
  1964年   49篇
  1963年   47篇
  1955年   34篇
排序方式: 共有6156条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
45.
46.

Purpose

Intravenous lidocaine given both intraoperatively and postoperatively decreases pain scores, reduces opioid consumption, and promotes faster return of bowel function following abdominal surgery. The purpose of this trial was to determine if intravenous lidocaine limited to the intraoperative period reduces length of hospital stay and improves functional recovery following abdominal hysterectomy.

Methods

Following Research Ethics Board approval and informed consent, women of American Society of Anesthesiologists’ class I and II undergoing abdominal hysterectomy were assigned randomly to lidocaine and control groups. Lidocaine subjects received an intravenous bolus of 1.5 mg·kg?1 followed by an infusion of 3 mg·kg?1·hr?1, while control subjects received matching placebo. Patients, anesthesiologists, and study personnel were blinded, and anesthesia and multimodal perioperative analgesia were standardized. The primary outcome of this trial was discharge from hospital on or before the second postoperative day (POD2). Additional criteria were assessed for secondary outcomes, i.e., discharge fitness on POD2, length of hospital stay, opioid use, numeric rating scores for pain, quality of recovery, and recovery of bowel function.

Results

Ninety of the 93 women who were recruited completed the study protocol. The characteristics of the patients in both groups were similar—lidocaine group (n = 44) and control group (n = 46)—and no difference was noted between groups in the numbers of women discharged from hospital on POD2 (10 lidocaine, 15 control; P = 0.295). Days to discharge fitness (P = 0.666) and length of hospital stay (P = 0.456) were also similar. Differences in opioid consumption, pain scores, and recovery were neither clinically nor statistically significant.

Conclusion

Intraoperative administration of intravenous lidocaine did not reduce hospital stay or improve objective measures of analgesia and recovery following abdominal hysterectomy. This trial was registered at ClinicalTrials.gov (NCT00382499).  相似文献   
47.
48.
Background. The outcome of valvular heart operations in patients with previous mediastinal radiation therapy was studied.

Methods. This is a single center retrospective study of 60 patients (37 females, 23 males) with a mean age of 62 ± 15 years (28 to 88 years old) operated on from January 1976 to December 1998. Valvular heart operations performed included aortic valve replacements (n = 26), mitral valve procedures (n = 16), tricuspid valve procedures (n = 6), and multiple valve procedures (n = 12). A total of 264 clinical, hemodynamic, electrocardiographic and echocardiographic variables were analyzed.

Results. Total follow-up was 199 patient-years with a mean of 3.3 ± 3.1 years and a range of 0 to 12.4 years old. Early mortality was 7 patients (12%). Early mortality in patients with constrictive pericarditis was 40% (4 of 10) compared with 6% (3 of 50) in patients without constrictive pericarditis. By univariate analysis, early mortality was associated with constrictive pericarditis (p = 0.011), reduced preoperative ejection fraction (p = 0.015), and longer cardiopulmonary bypass times (p = 0.037). A total of 14 patients (23%) required permanent pacemaker placement before (n = 7), during (n = 1), or early (n = 6) after valvular heart operations. There were 19 late deaths (malignancies, 7; heart failures, 5; other cardiac, 4; and other noncardiac, 3). Overall survival and freedom from late cardiac death and cardiac reoperation at 5 years for hospital survivors were 66% ± 8%, 82% ± 7%, and 93% ± 4%, respectively. By univariate analysis, late cardiac death was associated with low ejection fraction (p = 0.002), New York Heart Association (NYHA) functional class IV (p = 0.004), preoperative congestive heart failure (p = 0.02), and preoperative atrial fibrillation (p = 0.038). Eighty-five percent of the discharged patients were in NYHA functional class I or II at follow-up.

Conclusions. Early results of valve replacement after mediastinal radiation therapy were good except in the presence of constrictive pericarditis. Long-term outcome was limited by malignancy and heart failure. Early surgical intervention is recommended before the development of risk factors for late death, namely, severe symptoms, left ventricular dysfunction, and atrial fibrillation.  相似文献   

49.
50.

Introduction

Incidental gallbladder cancer is found in 0.6–2.1% of patients undergoing laparoscopic cholecystectomy for symptomatic gallstones. Patients with Tis or T1a tumours generally undergo no further intervention. However, spilled stones during surgery may have catastrophic consequences. We present a case and suggest aggressive management in patients with incidental gallbladder cancer who had spilled gallstones at surgery.

Case History

A 37-year-old woman underwent a laparoscopic cholecystectomy for symptomatic gallstones, during which some stones were spilled into the peritoneal cavity. Subsequent histological examination confirmed incidental pT1a gallbladder cancer. Hepatopancreatobiliary multidisciplinary team discussion agreed on regular six-monthly follow-up. The patient developed recurrent pain two years after surgery. Computed tomography revealed a lesion in segment 6 of the liver. At laparotomy, multiple tumour embedded gallstones were found on the diaphragm. Histological examination showed features (akin to the original pathology) consistent with a metastatic gallbladder tumour.

Conclusions

This case highlights the potential for recurrence of early stage disease resulting from implantation of dysplastic or malignant cells carried through spilled gallstones. It is therefore important to know if stones were spilled during original surgery in patients with incidental gallbladder cancer following a laparoscopic cholecystectomy. Aggressive and early surgical management should be considered for these patients.  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