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   1182篇
  免费   44篇
  国内免费   13篇
耳鼻咽喉   45篇
儿科学   17篇
妇产科学   48篇
基础医学   138篇
口腔科学   44篇
临床医学   117篇
内科学   186篇
皮肤病学   12篇
神经病学   118篇
特种医学   86篇
外科学   156篇
综合类   9篇
预防医学   78篇
眼科学   9篇
药学   87篇
中国医学   2篇
肿瘤学   87篇
  2023年   6篇
  2022年   14篇
  2021年   16篇
  2020年   15篇
  2019年   17篇
  2018年   31篇
  2017年   14篇
  2016年   20篇
  2015年   29篇
  2014年   30篇
  2013年   55篇
  2012年   85篇
  2011年   116篇
  2010年   65篇
  2009年   38篇
  2008年   90篇
  2007年   97篇
  2006年   72篇
  2005年   58篇
  2004年   58篇
  2003年   45篇
  2002年   34篇
  2001年   25篇
  2000年   38篇
  1999年   31篇
  1998年   11篇
  1997年   8篇
  1996年   10篇
  1994年   2篇
  1993年   2篇
  1992年   9篇
  1991年   10篇
  1990年   12篇
  1989年   8篇
  1988年   7篇
  1987年   4篇
  1986年   4篇
  1985年   9篇
  1984年   4篇
  1983年   3篇
  1981年   6篇
  1979年   4篇
  1978年   3篇
  1977年   2篇
  1975年   2篇
  1973年   2篇
  1970年   2篇
  1968年   2篇
  1967年   3篇
  1966年   4篇
排序方式: 共有1239条查询结果,搜索用时 15 毫秒
1.
The risks of induction must be carefully weighed against the risks of allowing the pregnancy to continue and not inducing labor. The aim of the study was to show labor and neonatal outcome of 335 deliveries inducted in 2004 at Institute of gynecology and obstetrics Clinical Center of Serbia. Inductions were performed with PGE2, PGE1 and Oxytocin. The best ripening effect was noted in PGE2 group. The average duration of labor was 8.6h in PGE1group, 5.9h in PGE2 group and 10.4h in OT group. Sixty eight labors finished with cesarean section (20%). Comparing duration of labor, percentage of emergency cesarean sections, incidence of fetal distress during the labor we suggest Dinoprostone, placed intracervically, as an agent of choice for induction of labor.  相似文献   
2.
Hepatitis is a rare complication of herpes simplex virus (HSV), often leading to acute liver failure (ALF), liver transplantation (LT), and/or death. Our aim was to identify variables associated with either survival or progression (death/LT), based on an analysis of cases in the literature and our institution. A total of 137 cases (132 literature, 5 institutional) of HSV hepatitis were identified. The main features at clinical presentation were fever (98%), coagulopathy (84%), and encephalopathy (80%). Rash was seen in less than half of patients. Most cases (58%) were first diagnosed at autopsy and the diagnosis was suspected clinically prior to tissue confirmation in only 23%. Overall, 74% of cases progressed to death or LT, with 51% in acyclovir-treated patients as compared to 88% in the untreated subjects (P=0.03). Variables on presentation associated with death or need for LT compared to spontaneous survival: male gender, age>40 yr, immunocompromised state, ALT>5,000 U/L, platelet count<75x10(3)/L, coagulopathy, encephalopathy, and absence of antiviral therapy. In conclusion, HSV hepatitis has a high mortality and is often clinically unsuspected. Patients who are male, older, immunocompromised, and/or presenting with significant liver dysfunction are more likely to progress to death and should thus be evaluated for LT early. Based on the frequent delay in HSV diagnosis, low risk-benefit ratio, and significantly improved outcomes, empiric acyclovir therapy for patients presenting with ALF of unknown etiology is recommended until HSV hepatitis is excluded.  相似文献   
3.
The referral pattern of 140 Dutch patients with oral mucosal lesions, who had been referred to a Department of Oral & Maxillofacial Surgery and Oral Pathology, shows that patients with oral mucosal lesions consult the dentist as often as the family doctor as the first source of help or information. Furthermore, family doctors were much more used to refer patients with oral mucosal disease to medical specialists rather than to the dentist or the oral and maxillofacial surgeon.  相似文献   
4.
Aim: Fas membrane-associated polypeptide antigen is a receptor molecule responsible for apoptosis-mediated signals. In animal models of acute viral hepatitis, apoptosis of hepatocytes is mediated by Fas-death receptors; therefore, the aim of this study was to evaluate the effect of interferon (IFN)-alpha on apoptotic markers and nuclease activity against different coding and non-coding single and double stranded RNAs during Fas-induced liver apoptosis. Methods: An in vivo experiment was performed with simultaneous administration of anti-Fas (CD95) antibodies and IFN-alpha, and an in vitro experiment was performed in hepatocyte cultures treated with anti-Fas antibodies and IFN-alpha. Results: Detection of apoptosis using Annexin V-FITC/propidium iodide, Bcl-2 and Bax expression in hepatocyte cultures confirmed the appearance of early apoptotic events and progression toward late apoptosis after anti-Fas antibody treatment. IFN-alpha had a tendency to retard the apoptosis process in Fas-induced apoptosis by increasing the number of viable cells and decreasing the number of cells in late apoptosis, by increasing the percentage of Bcl-2 positive cells, by decreasing the percentage of Bax positive cells, and by decreasing the nuclease activity compared to the anti-Fas antibody treated group. Total DNA and RNA concentration was much reduced in the Fas group and DNA fragmentation assay provided evidence for increased DNA degradation. Enhanced nuclease activity against DNA, rRNA, poly(A), poly(C), poly(U), poly(I:C), and poly(A:U) was manifested in the anti-Fas antibody treated group, except for the inhibitory-bound alkaline RNase. Conclusions: The results demonstrate that the RNA-degrading pathway in Fas-induced apoptosis can accelerate the liberation of the latent enzyme from the inhibitor complex. IFN-alpha prevented enormous, Fas-ligand induced degradation of all the substrates used in this experimental study, most probably due to similarities in the signal transduction pathways. Investigations of death receptor-induced apoptosis may lead to novel treatment combinations for patients with acute or chronic liver diseases.  相似文献   
5.
OBJECTIVE: To examine the effect of short-term improvements in glycaemic control on brachial artery endothelial function as a marker of cardiovascular health. METHODS: Persons with Type 2 diabetes who were poorly controlled on oral therapy were randomly assigned to monotherapy with repaglinide or combination therapy with repaglinide plus metformin. Brachial artery flow-mediated vasodilation was assessed by ultrasonography at randomization and following 16 weeks of therapy. The primary outcome was change in brachial artery endothelial function from baseline. Comparison of randomized groups was a secondary aim. RESULTS: Eighty-six participants were randomized, and 83 were followed to study completion. Post occlusion brachial artery vasodilation was 3.74% at baseline and 3.82% following 16 weeks of therapy (P = 0.77). The treatment effect was 0.08% (95% CI: -0.48%, 0.64%). No difference was seen between treatment groups (P = 0.69). Overall, A1C was reduced from 8.3% to 7.0%, with a greater reduction in the combination therapy group (from 8.4% to 6.7%) than in the monotherapy group (from 8.3% to 7.3%, p for difference between groups = 0.01). Statistically significant reductions were observed in fasting glucose, and plasminogen activator inhibitor-1. Statistically significant increases were observed for fasting insulin, uric acid, weight and BMI. CONCLUSIONS: Brachial artery endothelial function was not influenced by short-term improvements in glycaemic control. The CONTROL DM group was successful in lowering A1C. Future research should explore more intensive and longer-lasting improvements in glycaemic control on endothelial function. Some data previously published in abstract form (Diabetes 2001; 50 (Suppl. 2): A217).  相似文献   
6.
Clinical trials are the most widely accepted tools in the search for more effective supportive care drugs/interventions. The aim of our study was to determine Central Eastern European countries' (CEEC) involvement and future interest in conducting supportive care clinical trials. Our study was a part of an ESMO/MASCC program launched to support the development of supportive care in CEEC. The study was designed as a mailed questionnaire survey within the ESMO CEE Task Force. It involves national representatives from 18 countries. The purpose of the questionnaire was to assess the involvement and interest in conducting clinical trials in 13 representative supportive care fields: antiemetic therapy, cancer pain control, infections/febrile neutropenia, mucositis, fatigue, hypercalcemia, dyspnea, anorexia/cachexia, psychosocial support, toxicity reducing agents, hematopoietic growth factors, communication/education and quality of life. A total of 15 completed questionnaires were returned (83.3%). CEEC were mainly involved in clinical trials of hematopoietic growth factors (7/15), quality of life (6/15), antiemetic therapy (5/15), and cancer pain control (4/15). Increased interest was observed in the trials of fatigue, dyspnea, psychosocial support, infections / febrile neutropenia, communication / education and toxicity reducing agents. Clusters of CEEC that are similar in terms of their previous involvement and future interest in supportive care trials were identified. Our survey may prove to be a significant first step for CEEC active involvement in multinational clinical trials, which are crucial for improving supportive care standards.  相似文献   
7.
While an involvement of brain serotonin systems in schizophrenia has been suggested by many studies, the relative role of different serotonergic projections in the brain remains unclear. We therefore examined the effects of selective brain serotonin depletion on psychotropic drug-induced locomotor hyperactivity and prepulse inhibition, two animal models of aspects of schizophrenia. Pentobarbital-anesthetized (60 mg/kg, i.p.) male Sprague-Dawley rats were stereotaxically microinjected with 1 microl of a 5 microg/microl solution of the serotonergic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) into either the dorsal or median raphe nucleus. At 2 weeks after the surgery, rats with dorsal raphe lesions did not show changes in psychotropic drug-induced locomotor hyperactivity, but displayed partial disruption of prepulse inhibition. In contrast, rats with median raphe lesions showed significant enhancement of phencyclidine-induced, but not amphetamine-induced locomotor hyperactivity and a marked disruption of prepulse inhibition. These results provide evidence for differential involvement of serotonergic projections in locomotor hyperactivity and prepulse inhibition. This study may help to explain the role of different serotonin projections in the brain in the pathophysiology of schizophrenia.  相似文献   
8.
A case of Marfan syndrome with spontaneously and subsequently developed dissections of the aorta, one in the form of triple-barrel aorta, three times corrected by grafts is described. The autopsy revealed "healed" and acute dissections in almost the entire aorta outside the grafts. "Healed" thoracoabdominal dissection had true lumen (with entry and re-entry intimal tears), and old false lumen and in addition in its distal portion of a triple-barrel aorta was formed (dissection of healed aortic dissection). Lethal adventitial rupture occurred in the portion with an old false lumen. Dissection of the left subclavian artery, the right common carotid artery, resulting in saccular aneurysm, and avulsion of the right renal artery were also found.  相似文献   
9.
10.
Rapid Report     
Coexpression of KCNQ2 and KCNQ3 channels results in a 10-fold increased current amplitude compared to that of KCNQ2 alone, suggesting the formation of heteromultimeric channels. There is no interaction of either channel with KCNQ1. We evaluated the C-terminus as a potential interaction domain by construction of chimeras with interchanged C-termini of KCNQ1, KCNQ2 and KCNQ3 and functional expression in Xenopus oocytes. The chimera of KCNQ1 with a KCNQ2 C-terminus (Q1ctQ2) showed an 8-fold increase in current amplitude, and Q1ctQ3 a 3-fold increase when coexpressed with KCNQ3 and KCNQ2, respectively, indicating that the C-terminus contains an interaction domain. To characterize this interacting region, we studied further chimeras of KCNQ1 containing different parts of the KCNQ3 C-terminus for interaction with KCNQ2. We also evaluated short sequences of the KCNQ2 C-terminus for a dominant-negative effect on Q1ctQ3. According to the results of these experiments, functional interaction of KCNQ2 and KCNQ3 requires a highly conserved region of about 80 amino acids, previously called the A-domain, plus either 40 residues downstream of the A-domain (B-domain) or the proximal C-terminus between S6 and the A-domain. Furthermore, the chimeras Q1ctQ3 and Q2ctQ3 showed > 10-fold increased current amplitudes compared to KCNQ1 or KCNQ2 alone and a strong depolarizing shift of voltage-dependent activation. The proximal part of the KCNQ3 C-terminus was necessary to produce these effects. Our results indicate that specific parts of the C-terminus enable the interaction between KCNQ2 and KCNQ3 channels and that different parts of the KCNQ3 C-terminus are important for regulating current amplitude.  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