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   4412篇
  免费   426篇
  国内免费   28篇
耳鼻咽喉   41篇
儿科学   233篇
妇产科学   103篇
基础医学   525篇
口腔科学   153篇
临床医学   467篇
内科学   1130篇
皮肤病学   93篇
神经病学   286篇
特种医学   431篇
外科学   444篇
综合类   112篇
一般理论   1篇
预防医学   288篇
眼科学   45篇
药学   263篇
  1篇
中国医学   1篇
肿瘤学   249篇
  2023年   18篇
  2022年   18篇
  2021年   45篇
  2020年   43篇
  2019年   56篇
  2018年   73篇
  2017年   63篇
  2016年   70篇
  2015年   70篇
  2014年   88篇
  2013年   146篇
  2012年   155篇
  2011年   164篇
  2010年   163篇
  2009年   180篇
  2008年   146篇
  2007年   202篇
  2006年   203篇
  2005年   174篇
  2004年   163篇
  2003年   142篇
  2002年   110篇
  2001年   107篇
  2000年   121篇
  1999年   133篇
  1998年   151篇
  1997年   153篇
  1996年   149篇
  1995年   121篇
  1994年   118篇
  1993年   140篇
  1992年   102篇
  1991年   76篇
  1990年   78篇
  1989年   97篇
  1988年   87篇
  1987年   88篇
  1986年   67篇
  1985年   70篇
  1984年   59篇
  1983年   43篇
  1982年   34篇
  1981年   55篇
  1980年   38篇
  1979年   31篇
  1978年   36篇
  1977年   44篇
  1976年   34篇
  1975年   23篇
  1971年   17篇
排序方式: 共有4866条查询结果,搜索用时 0 毫秒
11.
12.
13.
Myositis is a rare complication following renal transplantation and is most commonly the result of drug-mediated myotoxicity. Other causative disorders include viral infection, electrolyte imbalance and myositis of autoimmune origin. We describe a 60-year-old patient who developed acute polymyositis 4 weeks after a 000 human leukocyte antigen (HLA) mismatch cadaveric renal transplant. Following an uncomplicated transplant course with maintenance triple immunosuppression (prednisolone, mycophenolate mofetil and cyclosporine), the patient presented with severe symmetrical proximal muscle weakness associated with a rise in serum creatine kinase to 46800 U/L. Electromyography confirmed myopathic changes and muscle biopsy demonstrated extensive muscle-fiber necrosis with an inflammatory infiltrate. There were no obviously culpable drugs and viral studies were negative. Prompt initiation of high-dose steroid therapy led to clinical and biochemical recovery. Acute polymyositis may occur following renal transplantation. Potential mechanisms include viral antigen transmission or a localized form of graft vs. host disease.  相似文献   
14.
Menorrhagia management options.   总被引:1,自引:0,他引:1       下载免费PDF全文
A prospective study of the management of menorrhagia in new patients presenting to gynaecological outpatients was undertaken at four centres in Northern Ireland and two in Great Britain. 325 patients were enrolled, the majority of whom (87%) had severe menorrhagia. Patients in all six centres were similar in relation to age, marital status, parity, use of contraception and severity of symptoms. 62% of the patients were managed medically, improved and were discharged. The rates of surgical intervention, in particular in women aged less than 40, appeared higher in the Northern Ireland hospitals than Great Britain. There is a need to review and audit current practices in the management of menorrhagia.  相似文献   
15.
Benefits of glucose and oxygen in multidose cold cardioplegia.   总被引:3,自引:0,他引:3  
We tested the effects of glucose and oxygen in cardioplegic solutions on myocardial protection in the isolated perfused working rat heart. Recovery from 2 hours' hypothermic (8 degrees C) cardioplegic arrest was examined in 93 hearts. Cardioplegic solution, which was delivered every 15 minutes, was supplemented with glucose 28 mmol/L as a substrate or sucrose 28 mmol/L as a nonmetabolizable osmotic control; it was equilibrated with either 98% oxygen or 98% nitrogen, both with 2% carbon dioxide. Four combinations of hyperkalemic cardioplegic solution were studied: nitrogen-sucrose, nitrogen-glucose, oxygen-sucrose, and oxygen-glucose. During hypothermic arrest, oxygenation of cardioplegic solution greatly reduced myocardial lactate production and prevented ischemic contracture as indicated by coronary vascular resistance. Glucose increased lactate production modestly but significantly only when the cardioplegic solution was nitrogenated. Although end-arrest myocardial adenosine triphosphate and creatine phosphate were greatly increased by oxygenation of cardioplegic solution (p less than 0.005), we could not detect improved preservation of these high-energy phosphates by glucose. Averaged over reperfusion, percent recovery of cardiac output for the nitrogen-sucrose, nitrogen-glucose, oxygen-sucrose, and oxygen-glucose solutions was 32.3% +/- 6.1%, 45.9% +/- 4.6%, 44.5% +/- 4.6%, and 62.2% +/- 4.5%, respectively. Oxygenation of the glucose solution or addition of glucose to the oxygenated solution significantly improved recovery of cardiac output. The benefits of glucose and oxygen were additive, so that the oxygen-glucose cardioplegic solution provided the best functional recovery. We conclude that the addition of glucose to the fully oxygenated multidose cold cardioplegic solution improves functional recovery without increasing lactate production during arrest.  相似文献   
16.
Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture.  相似文献   
17.
BACKGROUND. Pancreatic surgery is not uncommonly complicated by prolonged pancreatic drainage and fistula. Octreotide decreases pancreatic exocrine function and has been reported to improve closure of pancreatic and intestinal fistulae. This randomized, prospective trial was designed to evaluate the efficacy of postoperative octreotide in reducing pancreatic drainage and complications after resection of neuroendocrine tumors of the pancreas. METHODS. Patients with neuroendocrine tumors of the pancreas were entered into the study and randomized after operation to receive octreotide 150 micrograms subcutaneously every 8 hours or saline solution subcutaneously every 8 hours in a double-blinded fashion. Daily pancreatic drainage, total drainage, number of days to drain removal, and complications were recorded. RESULTS. Ten patients were given octreotide; eleven patients were given saline solution. The number of days to drain removal, daily drainage, and total drainage were not significantly different. Complications related to pancreatic drainage were not significantly different. CONCLUSIONS. Octreotide is not indicated for the routine postoperative management of patients with neuroendocrine tumors of the pancreas.  相似文献   
18.
Male genital oedema can be defined as swelling or the appearance of swelling of the scrotum and/or the penile shaft and prepuce. Despite the various causes of genital oedema reported in the published work, a concise approach to the evaluation and management has not been sufficiently addressed.  相似文献   
19.
Weight loss after gastric bypass procedures has been well studied, but the long-term metabolic sequelae are not known. Data on bone mineral density (BMD), calcium, parathyroid hormone, and vitamin D were collected preoperatively and at yearly intervals after gastric bypass procedures. A total of 230 patients underwent preoperative BMD scans. Fifteen patients were osteopenic preoperatively, and three patients subsequently developed osteopenia postoperatively within the first year. No patient had or developed osteoporosis. At 1 year, total forearm BMD decreased by 0.55% (n = 91; P = .03) and radius BMD had increased overall by 1.85% (n = 23; P = .008); both total hip and lumbar spine BMD decreased by 9.27% (n = 22; P < .001) and 4.53% (n = 31; P < .001), respectively. By the second postoperative year, BMD in the total forearm had decreased an additional 3.62% (n = 14; P<.001), whereas radius BMD remained unchanged. Although total hip and lumbar spine BMD significantly decreased at 1 year, by year 2 both total hip and lumbar spine BMD only slightly decreased and were not significantly different from before the operation. Serum calcium decreased from 9.8 mg/dL to 9.2 during the first year (not significant [NS]) and then to 8.8 (NS) by the second year. Parathyroid hormone increased from 59.7 pg/mL (nl 10-65 pg/mL) preoperatively to 63.1 during year 1 (NS) and continued to increase to 64.7 by year 2 (NS). No difference was noted among levels of 25-hydroxy vitamin D preoperatively (25.2 ng/mL; nl 10-65 ng/mL), at 1 year (34.4), and at 2 years (35.4). Our data indicate that bone loss is highest in the first year after gastric bypass with stabilization, and that, in some cases, there is an increase in bone density after the first year. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation).  相似文献   
20.
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