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   1420篇
  免费   46篇
  国内免费   5篇
耳鼻咽喉   19篇
儿科学   70篇
妇产科学   83篇
基础医学   92篇
口腔科学   74篇
临床医学   108篇
内科学   282篇
皮肤病学   29篇
神经病学   76篇
特种医学   36篇
外科学   423篇
综合类   15篇
预防医学   25篇
眼科学   33篇
药学   64篇
中国医学   5篇
肿瘤学   37篇
  2023年   4篇
  2022年   6篇
  2021年   15篇
  2020年   7篇
  2019年   14篇
  2018年   20篇
  2017年   13篇
  2016年   20篇
  2015年   14篇
  2014年   27篇
  2013年   28篇
  2012年   67篇
  2011年   82篇
  2010年   46篇
  2009年   27篇
  2008年   96篇
  2007年   104篇
  2006年   118篇
  2005年   120篇
  2004年   114篇
  2003年   115篇
  2002年   98篇
  2001年   66篇
  2000年   73篇
  1999年   56篇
  1998年   5篇
  1997年   14篇
  1996年   6篇
  1995年   6篇
  1994年   5篇
  1993年   3篇
  1992年   16篇
  1991年   13篇
  1990年   16篇
  1989年   16篇
  1988年   4篇
  1987年   5篇
  1986年   2篇
  1985年   3篇
  1984年   1篇
  1982年   1篇
  1979年   1篇
  1977年   1篇
  1976年   1篇
  1966年   2篇
排序方式: 共有1471条查询结果,搜索用时 15 毫秒
41.
We analyzed the postoperative short- and mid-term outcomes of a series of patients with annuloaortic ectasia who underwent a modified Bentall operation in our clinic from September 2000 through March 2006. The study included 44 patients. Their average age was 53.4 +/- 14.1 years. The underlying disease was degenerative aortic aneurysm in 42 patients (95.5%) and acute aortic dissection in 2 patients (4.5%). Six patients (13.6%) had Marfan phenotype. Aortic insufficiency was moderate in 30 patients (68.2%) and severe in 14 patients (31.8%). In our modification of the Bentall technique, we completed the resection of the aortic root while leaving 5 to 10 mm of native aortic wall tissue to support the anastomosis. A long piece of Teflon felt (width, 0.5-1 cm) was laid on the annulus, and nonpledgeted 2-0 polyester sutures were passed in turn through the Teflon felt, the preserved aortic tissue, and the aortic annulus. A thin piece of Teflon felt was also used in the coronary artery reimplantation sites. Fibrin glue was routinely applied to all anastomoses. There were no intraoperative deaths. One patient died in the hospital after surgery for acute type I aortic dissection. Another patient died 1 year after the operation from prosthetic-valve endocarditis. No patient required surgical correction of excessive postoperative bleeding. Kaplan-Meier curves showed overall survival of 0.94 (95% confidence intervals, 0.9-0.99). We consider our approach an easy, effective way to minimize bleeding from the anastomoses and at the aortic root--a common challenge in aortic surgery.  相似文献   
42.
43.
BACKGROUND: Despite the tremendous advances made in the management of genital herpes, neonatal herpes has not been completely eradicated. In addition, the time from the onset of symptoms in the neonate to the diagnosis of herpes and institution of antiviral medication has remained unchanged in the past 20 years. CASE: Neonatal herpes infection resulted from primary, first-episode peripartum genital herpes in the mother. Due to a high index of suspicion, herpes testing was performed on the infant and neonatal herpes diagnosed. Subsequently, the mother developed evidence of primary herpes infection. CONCLUSION: This case report illustrates the problems with current management strategies for prevention of neonatal herpes.  相似文献   
44.
45.
BACKGROUND/AIMS: The timing of GpIIb/IIIa inhibitor administration may be important in achieving early epicardial and myocardial reperfusion. We evaluated the effect of early tirofiban on myocardial salvage and cardiovascular outcome in patients with acute myocardial infarction (AMI) undergoing infarct-related artery stenting. METHODS: Patients (n = 66) with a first AMI presenting <6 h from onset of symptoms were randomized to either early administration of tirofiban in the emergency room (n = 32) or later administration in the catheterization laboratory (n = 34) (tirofiban bolus dose of 10 microg/kg, followed by 0.15 microg/kg for 24 h). The primary end-point was the degree of myocardial salvage, determined by means of serial scintigraphic studies with technetium-99m sestamibi. Thirty-day major adverse cardiac events were also assessed. RESULTS: There were no significant differences in patient characteristics or in their presentation. The mean door-to-balloon time was similar in both groups (43 +/- 12 and 53 +/- 9 min, p = 0.08). The early and late treatment groups received tirofiban 18 +/- 4 and 52 +/- 10 min after admission, respectively. Angiographic analysis revealed a higher initial frequency of TIMI grade 3 flow in the early group (31% vs. 12%, p = 0.04). Procedural success was achieved in all patients. Myocardial risk area were comparable between early and late treatment groups (35.6 +/- 12.2% vs. 39.3 +/- 14.0%, p = 0.6). Scintigraphic outcomes demonstrated a significant reduction in the final infarction size (11.8 +/- 5.2% vs. 22.4 +/- 6.2%, p = 0.01), and improvement in salvage index (0.68 +/- 0.22 vs. 0.44 +/- 0.18, p = 0.003) in favor of the early tirofiban group. The thirty-day composite end-point of death, recurrent MI or rehospitalization also favored the early group (6% early, 15% late, p = 0.06). CONCLUSION: Early tirofiban administration enhanced the degree of myocardial salvage and clinical outcome in patients with AMI undergoing infarct-related artery stenting.  相似文献   
46.
1. The importance of insulin in diabetic gastro-intestinal complications has been postulated. The present study was designed to investigate short-term effect of insulin on different smooth muscles isolated from non-diabetic animals. 2. The contractile responses of isolated guinea-pig ileum to acetylcholine and histamine and the serotonin-induced contractions of rat stomach fundus strips were inhibited by insulin in a non-competitive manner. The contractions of rat vas deferens elicited by noradrenaline and tyramine were also inhibited in the presence of insulin. 3. Insulin caused dose-dependent relaxation on the isolated rat duodenum. The relaxing response to insulin was not affected in the presence of atropine, phentolamine, propranolol, nicotinic acid, tetrodotoxin, tetraethylammonium, ouabain and nifedipine. The relaxing effect of insulin on the isolated rat duodenum was inhibited by sodium orthovanadate, trifluoperazine, verapamil, aspirin and dexamethasone, non-competitively. 4. The above results strongly suggest that the relaxing or inhibitory effect of insulin on the smooth muscles is closely related with prostanoid metabolism. Furthermore, it is concluded that this effect of insulin on the smooth muscles may be due to activation of Ca2+-pump ATPase(s).  相似文献   
47.
48.
The aim of the study was to evaluate the presence of aromatase cytochrome P450 enzyme (P450AROM) expression in normal pituitary tissues and tumor tissues of patients with prolactinoma and to examine the impact of the P450AROM expression on clinical outcome. Twenty-six consecutive human pituitary tissue samples were obtained from autopsies performed at the Institute of Forensic Medicine. Sixty-four patients who had an adenomectomy between 2000 and 2009 after prolactinoma diagnosis with histologically confirmed pituitary tumor tissues were retrospectively included in this study. The slices from the pituitary tissues were subjected to immunohistochemical staining for evaluation of P450AROM and estrogen receptor beta (ER beta) subunit. Immunohistochemistry results were compared according to age, gender, remission rate, resistance and invasion status of the patients. Higher than normal P450AROM expression was found in the pituitary tissues of the patients with prolactinoma (p < 0.001). P450AROM intensity had no relation to resistance or remission in patients with prolactinoma (p = 0.44, p = 0.45, respectively). The subgroup analysis showed that compared to males without invasive adenoma, males with invasive adenoma had higher P450AROM expression (p = 0.048). ER beta was found to have an impact on resistance (p = 0.049). This study shows that P450AROM expression is present in the pituitary tissues of patients with prolactinoma and that this presence could be important in development and tumor behavior of prolactinomas.  相似文献   
49.
We report the case of an enormous right atrial hemangioma in an asymptomatic 42-year-old woman. The diagnosis was made by echocardiogram after the patient was found to have an abnormal EKG during a routine medical exam. The hemangioma is the largest described in English literature. The tumor was surgically resected and the patient did well postoperatively. In this case report, we discuss the discovery of the tumor and treatment of our patient. A brief discussion of cardiac hemangiomas follows.  相似文献   
50.
The use of phosphodiesterase inhibitors such as milrinone in the treatment of severe heart failure is frequently restricted because they cause vasodilation and hypotension. In patients with decompensated heart failure with hypotension after treatment with milrinone, low doses of vasopressin restored blood pressure without inhibiting the inotropic effect of milrinone.  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