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   3214篇
  免费   164篇
  国内免费   19篇
耳鼻咽喉   76篇
儿科学   129篇
妇产科学   124篇
基础医学   223篇
口腔科学   126篇
临床医学   305篇
内科学   780篇
皮肤病学   144篇
神经病学   192篇
特种医学   130篇
外科学   743篇
综合类   43篇
预防医学   63篇
眼科学   98篇
药学   111篇
中国医学   7篇
肿瘤学   103篇
  2023年   29篇
  2022年   58篇
  2021年   84篇
  2020年   65篇
  2019年   68篇
  2018年   105篇
  2017年   79篇
  2016年   128篇
  2015年   119篇
  2014年   127篇
  2013年   202篇
  2012年   245篇
  2011年   247篇
  2010年   141篇
  2009年   103篇
  2008年   224篇
  2007年   228篇
  2006年   194篇
  2005年   188篇
  2004年   158篇
  2003年   147篇
  2002年   130篇
  2001年   75篇
  2000年   43篇
  1999年   43篇
  1998年   16篇
  1997年   7篇
  1996年   8篇
  1995年   5篇
  1994年   7篇
  1993年   6篇
  1992年   15篇
  1991年   8篇
  1990年   8篇
  1989年   8篇
  1988年   9篇
  1987年   9篇
  1986年   6篇
  1985年   7篇
  1984年   6篇
  1980年   2篇
  1979年   5篇
  1974年   3篇
  1972年   2篇
  1971年   2篇
  1970年   3篇
  1969年   2篇
  1967年   6篇
  1966年   3篇
  1909年   2篇
排序方式: 共有3397条查询结果,搜索用时 10 毫秒
991.
BACKGROUND: Although the use of opioids during general anaesthesia suppresses stress response to surgery and pain, the effects on antidiuretic hormone (ADH) are controversial. The aim of this study was to find the effects of morphine with either intravenous infusion or epidural route on ADH and other stress hormones. METHODS: Fifty children aging (1-15 years) undergoing major genito-urinary or abdominal operations were included in this study. The patients were allocated randomly to two groups receiving either a single dose of epidural morphine 0.1 mg.kg-1 (EP group, n = 25) postinduction or morphine infusion (INF group; n = 25) at 0.02 mg.kg-1.h-1 following 0.05 mg.kg-1 bolus. Blood samples were withdrawn for plasma ADH, osmolality, glucose, cortisol, insulin and morphine level analysis following induction and 1, 5, 12 and 24 h after initial morphine administration. RESULTS: The two groups were similar in demographic factors, pain scores, sedation scores, and incidence of nausea and vomiting. The amount of morphine received was different between groups and the changes in serum levels of morphine were statistically significant in EP group ( P < 0.05). The changes in cortisol, blood glucose and insulin levels were insignificant in both groups (P > 0.05). The changes of ADH levels were significant at time-points in both groups, reaching control levels at the 24th hour (P < 0.05). CONCLUSION: Despite the effective pain therapy and suppression of cortisol and insulin response to surgical stimulus, the increase in ADH secretion is not effected by systemic or epidural morphine administration.  相似文献   
992.
A new indole alkaloid, galanthindole, was isolated from Galanthus plicatus ssp. byzantinus (Amaryllidaceae), a plant native to northwestern Turkey. Incorporating a non-fused indole ring, galanthindole may represent the prototype of a new subgroup of the Amaryllidaceae alkaloids. Two other bases, (+)-11-hydroxyvittatine and hordenine, are also reported from the same plant.  相似文献   
993.
The rationale of this study is based on the fact that, both proteinuria and elevated asymmetric dimethyl arginine (ADMA) levels have been linked to the progression of vascular disease. Currently, there is not enough knowledge about any association between the levels of proteinuria and ADMA levels. Seventy-eight non-diabetic patients (42 men, 36 women, mean age of 26.1+/-5.2 years) with proteinuria having normal glomerular filtration rate were enrolled along with 38 healthy subjects (20 men, 18 women, mean age of 26.9+/-5.9 years). Proteinuria was below 3.5 g/day in 40 patients and above 3.5 g/day in 38 patients. Both groups had similar age, gender, and body mass index distributions. Serum ADMA, symmetric dimethyl arginine (SDMA), immunoreactive insulin, and high sensitivity C reactive protein (hsCRP) levels were measured. Insulin resistance was determined by homeostasis model assessment (HOMA). Serum ADMA, SDMA, insulin, hsCRP levels, and HOMA indexes were significantly higher in patients than in healthy control subjects. The above parameters were higher in the nephrotic range proteinuria group when compared to patients having protein levels below 3.5 g/day. There were significant correlations between the levels of proteinuria and the above parameters. According to the regression analysis, levels of proteinuria and hsCRP were significant determinants of serum ADMA levels. Our results indicate that, independent of other risk factors, ADMA is directly associated with proteinuria. Further studies are recommended to find out whether elevated ADMA levels are implicated in the high cardiovascular risk of proteinuric nephropathies.  相似文献   
994.
Human chorionic gonadotropin deteriorates the histology of rat testes   总被引:1,自引:0,他引:1  
OBJECTIVES: It is not yet certain whether early hormonal treatment in cryptorchidism is safe for germ cells. We investigated the histologic effects of human chorionic gonadotropin (hCG) therapy on descended testes of rats. DESIGN AND SETTING: Thirty male Wistar albino rats were randomized into two groups. The rats of the hCG group (n=15) were administered 50 IU/kg/day hCG once daily via the subcutaneous route for 15 days. Fifteen rats received subcutaneous isotonic saline and acted as controls. At the first month, testicular tissue was obtained after scarification in both groups. The histological examination was performed to evaluate the seminiferous tubular diameter, germinal membrane thickness, and the percentage of the open seminiferous tubule lumen in each testis to compare the two groups. RESULTS: The percentage of the open seminiferous tubular lumen in testicular tissues of hCG-treated rats was higher than that of controls (p<0.05). The mean germinal membrane thickness in testicular tissues of the hCG group was statistically lower than that of the control group (p<0.05). There was no statistical difference between mean seminiferous tubular diameter in testicular tissues of hCG-treated rats and controls, as expected (p>0.05). Additionally, there were two interesting cases of Sertoli cell only appearance in the hCG group. CONCLUSIONS: We may assume that hCG impairs the seminiferous tubule histology in normal testes of rats. Thus, further experimental studies on dose dependency and the reversibility of these effects are warranted.  相似文献   
995.
Bladder calculi: did the clinical picture change?   总被引:2,自引:0,他引:2  
Hammad FT  Kaya M  Kazim E 《Urology》2006,67(6):1154-1158
  相似文献   
996.
We report a case of peri-prosthetic tuberculous infection nine years after total hip arthroplasty in a patient with no history of tuberculosis before the procedure. Further investigation revealed active pulmonary tuberculosis which was thought to have spread haematogeneously to the arthroplasty. The infection did not respond to standard antituberculous drugs. Removal of the prosthesis and insertion of an antibiotic spacer were required.  相似文献   
997.
A 45-year-old woman whose MR images revealed a lobulated, complicated cyst with septations on the superior pole of left kidney underwent retroperitoneoscopic cyst marsupialization. In pathologic examination beneath the atrophic adrenal gland, hyalinized, calcification foci cyst wall without any surrounding epithelium was seen microscopically. It was reported to be “adrenal pseudocyst”.  相似文献   
998.
A cystic lesion of the liver extending into the inferior vena cava was discovered in a 33-year old female patient suffering from dyspnea, pain and swelling in the legs. Plain chest X-ray was normal. CT and MRI of the thorax showed a cystic lesion within the right pulmonary artery. The liver lesion was treated by a partial cystectomy and omentoplasty, inferior vena cava and bile ducts repair. Through a right thoracotomy, a hydatid cyst was found in the pulmonary artery and enucleated. Although very rare, pulmonary artery hydatidosis may be the cause of an unexplained dyspnea in patients with hydatidosis of the liver.  相似文献   
999.
PURPOSE: To report a case of late onset diffuse lamellar keratitis (DLK) 11 months after LASIK due to Ecballium elaterium exposure. METHODS: A 25-year-old man underwent bilateral LASIK. No complications were observed during the early postoperative period. RESULTS: Eleven months after LASIK surgery, grade II DLK was diagnosed after an Ecballium elaterium herb seed burst and splashed into the patient's left eye. Topical steroid treatment was administered and DLK healed in 2 weeks without complication. CONCLUSIONS: Although DLK typically develops in the early postoperative period, it could occur months after surgery. Treatment should begin as soon as DLK is diagnosed.  相似文献   
1000.
Blood stream infections due to Candida species are becoming increasingly important causes of morbidity and mortality in hospitalized patients. Risk factors that predispose patients to developing invasive Candida infections have been documented as, iatrogenic and/or nosocomial conditions and immunosuppression. In the present report, we want to emphasize the risk factors that predispose individuals to the development of candidemia, particularly those that are relevant to our patient. We describe a female patient with diabetes mellitus who had been receiving glucocorticoids for 20 years as replacement therapy for hypopituitarism resulting from hypophysis adenoma surgery. The patient received antibiotic therapy for recurrent wound infections and was hospitalized for a long time, including a period in the intensive care unit and instrumented. The patient eventually succumbed to fungemia caused by a fluconazole-resistant strain of C. albicans strain.  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