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   1434篇
  免费   75篇
  国内免费   8篇
耳鼻咽喉   13篇
儿科学   110篇
妇产科学   148篇
基础医学   121篇
口腔科学   77篇
临床医学   116篇
内科学   317篇
皮肤病学   31篇
神经病学   115篇
特种医学   36篇
外科学   215篇
综合类   15篇
预防医学   29篇
眼科学   73篇
药学   62篇
中国医学   2篇
肿瘤学   37篇
  2023年   16篇
  2022年   21篇
  2021年   43篇
  2020年   41篇
  2019年   37篇
  2018年   49篇
  2017年   46篇
  2016年   65篇
  2015年   64篇
  2014年   54篇
  2013年   103篇
  2012年   110篇
  2011年   144篇
  2010年   87篇
  2009年   63篇
  2008年   103篇
  2007年   113篇
  2006年   95篇
  2005年   97篇
  2004年   66篇
  2003年   45篇
  2002年   34篇
  2001年   11篇
  2000年   5篇
  1999年   1篇
  1998年   2篇
  1996年   1篇
  1993年   1篇
排序方式: 共有1517条查询结果,搜索用时 31 毫秒
91.
Saricaoglu F  Dal D  Salman AE  Doral MN  Kilinç K  Aypar U 《Anesthesia and analgesia》2005,101(3):904-9, table of contents
We studied the effect of ketamine sedation on oxidative stress during arthroscopic knee surgery with tourniquet application by determining blood and tissue malonyldialdehyde (MDA) and hypoxanthine (HPX) levels. Thirty ASA I-II patients undergoing arthroscopic knee surgery with tourniquet were randomly divided into two groups. Spinal anesthesia induced with 12.5 mg bupivacaine was administered to all patients. In the ketamine group, after IV administration of 0.01 mg/kg midazolam, a continuous infusion of ketamine (0.5 mg . kg(-1) . h(-1)) was used until the end of surgery whereas the placebo group received a volume-equivalent placebo infusion. Ramsey Sedation Scale (RSS) was used for assessing the sedation level. Venous blood and synovial membrane tissue samples were obtained before ketamine infusion, at 30 min of tourniquet ischemia, and at 5 min after tourniquet deflation for MDA and HPX measurements. Tissue MDA and HPX levels were significantly less in the ketamine group than the control group after reperfusion. RSS scores were higher in the ketamine group without any adverse effect. We conclude that ketamine sedation attenuates lipid peroxidation markers in arthroscopic knee surgery with tourniquet application.  相似文献   
92.
93.
94.
95.
AIM/OBJECTIVE: The aim of this study was to perform periodontal assessment, using the CPITN index, on patients undergoing renal dialysis. METHODS: The periodontal conditions of 342 subjects undergoing renal dialysis from eight renal dialysis centres were examined using CPITN. Subjects were distributed into four age groups, 16-19, 20-34, 35-44 and > or =45 years. The study was conducted during a 6-month period. All clinical examinations were performed by one examiner. RESULTS: There was a significant positive relationship between the CPITN scores and age (r=0.164, p=0.002) and dialysis duration (r = 0.240, p=0.000). There was no statistically significant difference between male and female patients (p>0.05). None of the age groups had healthy sextants. The 35-44 year-age group had a higher number of sextants with deep pockets (0.19) than the other age groups and edentulous sextants were the highest among the oldest age group (1.89). CONCLUSION: A very small portion of the renal dialysis population is affected by severe forms of periodontitis requiring complex periodontal treatment. However, all such patients should be given oral hygiene education as a priority.  相似文献   
96.
Albuterol overdose can lead to tachycardia, hypotension, tremor, hypokalemia, and hyperglycemia in children. Hypoglycemia had been previously reported in only one child. We describe a 3-year-old boy who ingested high-dose albuterol in this report. On arrival to the emergency department, the child was agitated and had noticeable restlessness, sinus tachycardia, mild hypokalemia (3.2 mEq/L), and hyperglycemia (187 mg/dL). Activated charcoal and intravenous hydration were given, and electrocardiogram monitoring was performed. Sinus tachycardia resolved within 4 to 6 hours. Hypoglycemia (45 mg/dL) was identified 4 hours after admission. The child recovered uneventfully within 24 hours with glucose replacement. This case suggests that hypoglycemia could be a late complication of acute albuterol overdose; thus, the period of observation should be extended in these cases.  相似文献   
97.
OBJECTIVE: This prospective study investigated the occurrence of hyperhomocysteinemia in a population of patients with gestational diabetes. The aim was to determine whether elevated plasma homocysteine is associated with gestational diabetes in Turkish women. STUDY DESIGN: This prospective controlled study was conducted in the Department of Obstetrics and Gynecology of the Baskent University Faculty of Medicine between April 2002 and June 2003, and involved 304 Turkish women with uncomplicated pregnancies who were at 24-28 weeks gestation. The women in the study were assigned to one of three groups according to the results of the 50-g glucose screening and the oral glucose tolerance test (OGTT): group 1 comprised women who had normal glucose levels (< or = 135 mg/dL) after the 50-g challenge; group 2 comprised women with abnormal screening test results (> 135 mg/dL) but normal OGTT results; and group 3 comprised patients with gestational diabetes mellitus (GDM) according to the OGTT. Levels of fasting glucose, homocysteine, vitamin B(12) and folic acid, total cholesterol, high density lipoprotein (HDL) cholesterol, and triglycerides, low density lipoprotein (LDL) cholesterol and very low density lipoprotein (VLDL) cholesterol levels were measured in the three groups. Levels of insulin sensitivity were calculated using the homeostasis model assessment (HOMA) formula. RESULTS: The mean level of homocysteine in group 1 was significantly lower than the levels in groups 2 and 3 (p < 0.001) The mean triglyceride and VLDL levels in group 3 were significantly higher than the corresponding levels in group 1 (p < 0.05 for both). There were no significant differences among the groups with respect to levels of total cholesterol, vitamin B(12), folic acid, creatinine, fasting glucose or insulin. The mean HOMA value in group 3 was significantly higher than that in group 1 (p < 0.05). Only the blood glucose level after the 50-g glucose screening [p = 0.000, 95% confidence interval (CI) 0.009-0.027] had a significant correlation with homocysteine levels. CONCLUSION: In this prospective study of Turkish women, we found that patients with gestational diabetes and women with abnormal screening test results (> 135 mg/dL) but normal OGTT results have higher homocysteine levels than normal pregnant women. This increased level seems to be related to an abnormal 50-g test but not to insulin resistance. Further investigations are needed to follow up for these patients in the postpartum period and later in their life.  相似文献   
98.
Sinovenous thrombosis is a definite cause of mortality or morbidity in newborns. Perinatal hypoxia is one of the well known risk factors. Two term newborns were diagnosed to have cerebral venous thrombosis after a hypoxic-ischemic insult. They were later found to have carnitine deficiency. Both of the patients died. Carnitine was previously shown to have inhibitory effects on thrombogenesis in experimental studies. The possible contribution of carnitine in thrombogenesis was discussed.  相似文献   
99.
Aydar E  Palmer CP  Djamgoz MB 《Cancer research》2004,64(15):5029-5035
The sigma (sigma) receptor and its agonists have been implicated in a myriad of cellular functions, biological processes and diseases. Whereas the precise molecular mechanism(s) of sigma receptors and their involvement in cancer cell biology have not been elucidated, recent work has started to shed some light on these issues. A molecular model has been proposed for the cloned sigma1 receptor; the precise molecular nature of the sigma2 receptor remains unknown. sigma receptors have been found to be frequently up-regulated in human cancer cells and tissues. sigma2 receptor drugs particularly have been shown to have antiproliferative effects. An interesting possibility is that sigma and/or sigma1 drugs could produce anticancerous effects by modulating ion channels. As well as proliferation, a variety of other metastatic cellular behaviors such as adhesion, motility, and secretion may also be affected. Other mechanisms of sigma receptor action may involve interaction with ankyrin and modulation of intracellular Ca(2+) and sphingolipid levels. Although more research is needed to further define the molecular physiology of sigma receptors, their involvement in the cellular pathophysiology of cancer raises the possibility that sigma drugs could be useful as novel therapeutic agents.  相似文献   
100.
Philadelphia chromosome negative chronic myeloproliferative disorders (Ph- CMPD) comprise haematopoietic stem cell disorders with currently unknown underlying molecular defect. Insulin-like growth factor 2 (IGF-2) is an imprinted gene that is known to be involved in the regulation of normal cell growth and that is overexpressed by a variety of tumors. The expression of IGF-2 in bone marrow cells is largely unknown. In order to elucidate gene expression level, protein expression pattern, and a potential role of IGF-2 in the pathogenesis of Ph- CMPD, we quantitatively analyzed the expression of the IGF-2 gene in bone marrow cells of 69 cases with Ph- CMPD and 31 control cases by applying real-time RT-PCR. IGF-2 gene expression in idiopathic myelofibrosis (IMF) was significantly increased by up to 11-fold as compared to the control group (P < 0.0001). IMF also expressed higher IGF-2 gene level as compared to essential thrombocythaemia (ET) and polycythaemia vera (PV) (P < 0.0001, P = 0.005, respectively). Paranuclear IGF-2 protein could be demonstrated in IMF, ET, and PV exclusively in megakaryocytes and myeloid progenitor cells in contrast to undetectable IGF-2 protein in control cases. We conclude that overexpression of the IGF-2 gene is a pathogenic feature in IMF. In addition, an abundant translational and post-translational processing could explain the accumulation of IGF-2 protein detectable in all Ph- CMPD entities in contrast to non-neoplastic haematopoiesis. We conclude that IGF-2 represents a new molecular target for evaluation of underlying fundamental pathomechanisms in Ph- CMPD.  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