全文获取类型
收费全文 | 671篇 |
免费 | 43篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 41篇 |
妇产科学 | 12篇 |
基础医学 | 91篇 |
口腔科学 | 30篇 |
临床医学 | 45篇 |
内科学 | 123篇 |
皮肤病学 | 17篇 |
神经病学 | 11篇 |
特种医学 | 144篇 |
外国民族医学 | 1篇 |
外科学 | 41篇 |
综合类 | 50篇 |
预防医学 | 43篇 |
眼科学 | 7篇 |
药学 | 25篇 |
中国医学 | 4篇 |
肿瘤学 | 32篇 |
出版年
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 14篇 |
2017年 | 12篇 |
2016年 | 14篇 |
2015年 | 12篇 |
2014年 | 20篇 |
2013年 | 33篇 |
2012年 | 27篇 |
2011年 | 24篇 |
2010年 | 44篇 |
2009年 | 45篇 |
2008年 | 27篇 |
2007年 | 20篇 |
2006年 | 10篇 |
2005年 | 7篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 34篇 |
1997年 | 33篇 |
1996年 | 34篇 |
1995年 | 36篇 |
1994年 | 23篇 |
1993年 | 20篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 7篇 |
1989年 | 15篇 |
1988年 | 14篇 |
1987年 | 10篇 |
1986年 | 13篇 |
1985年 | 9篇 |
1984年 | 12篇 |
1983年 | 14篇 |
1982年 | 12篇 |
1981年 | 13篇 |
1980年 | 15篇 |
1979年 | 4篇 |
1978年 | 8篇 |
1977年 | 2篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1955年 | 1篇 |
1950年 | 1篇 |
1949年 | 1篇 |
排序方式: 共有718条查询结果,搜索用时 31 毫秒
711.
The incidence of hepatocellular carcinoma is increasing worldwide as well as the associated risk factors, some of which include exposure to aflatoxin B1, Hepatitis B (HBV) virus and hepatitis C (HCV) virus. Mutation of tumour suppressor gene p53 at codon 249ser at exon 7 has been found to contribute significantly to replication of damaged DNA and subsequent tumour progression. The x gene of HBV (HBx) is the most common open reading frame integrated into the host genome in hepatocellular carcinoma and the integrated HBx is frequently mutated in hepatocellular carcinoma. Mutant HBx proteins still retain their ability to bind to p53 thereby attenuating DNA repair and p53-mediated apoptosis. 相似文献
712.
MI Strakhova CA Cuff AM Manelli TL Carr DG Witte JL Baranowski TA Vortherms TR Miller L Rundell MJ McPherson RM Adair AA Brito BM Bettencourt BB Yao JM Wetter KC Marsh H Liu MD Cowart JD Brioni TA Esbenshade 《British journal of pharmacology》2009,157(1):44-54
Background and purpose:
The histamine H4 receptor is widely expressed in cells of immune origin and has been shown to play a role in a variety of inflammatory processes mediated by histamine. In this report, we describe the in vitro and in vivo anti-inflammatory properties of a potent histamine H4 receptor antagonist, A-940894 (4-piperazin-1-yl-6,7-dihydro-5H-benzo[6,7]cyclohepta[1,2-d]pyrimidin-2-ylamine).Experimental approach:
We have analysed the pharmacological profile of A-940894 at mouse native, rat recombinant and human recombinant and native, histamine H4 receptors by radioligand binding, calcium mobilization, mast cell shape change, eosinophil chemotaxis assays and in the mouse model of zymosan-induced peritonitis.Key results:
A-940894 potently binds to both human and rat histamine H4 receptors and exhibits considerably lower affinity for the human histamine H1, H2 or H3 receptors. It potently blocked histamine-evoked calcium mobilization in the fluorometric imaging plate reader assays and inhibited histamine-induced shape change of mouse bone marrow-derived mast cells and chemotaxis of human eosinophils in vitro. In a mouse mast cell-dependent model of zymosan-induced peritonitis, A-940894 significantly blocked neutrophil influx and reduced intraperitoneal prostaglandin D2 levels. Finally, A-940894 has good pharmacokinetic properties, including half-life and oral bioavailability in rats and mice.Conclusions and Implications:
These data suggest that A-940894 is a potent and selective histamine H4 receptor antagonist with pharmacokinetic properties suitable for long-term in vivo testing and could serve as a useful tool for the further characterization of histamine H4 receptor pharmacology. 相似文献713.
Objective: The aim of this study is to assess the correlation between traditional cardiovascular risk factors and elevated plasma tHcy level in Nigerian hypertensive. Methods: Thirty-six hypertensive patients were recruited with 36 age and sex-matched controls. The age, sex and anthropometric measurements including height, weight and body mass index (BMI) were taken. Plasma total cholesterol, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), triglycerides and tHcy were analyzed. The results of the two groups were compared. Results: The mean total cholesterol and LDL- C were significantly higher in the subjects than in the controls (P = 0.01 and 0.03 respectively). On the other hand, means of HDL-C and triglycerides were not significantly different between the two groups (P =0.06 and 0.68 respectively). Mean total plasma tHcy was ( 12.95 ±4.9) μmol/L in hypertensive patients when compared with ( 11.29 ±3.6) μmol/L in the controls (P = 0.09) , however the mean tHcy was significantly higher in hypertensive patients who had stroke or myocardial infarction than those without these complications (one way Anova F = 3.63, P = 0.04). Significant positive correlation was seen between tHcy and systolic blood pressure, diastolic blood pressure, BMI and LDL-C. Conclusion : The study suggests that elevated plasma tHcy may predict occurrence of cardiovascular complications in hypertensive individuals. 相似文献
714.
AA da Silva L Bingle PM Speight CD Bingle T Mauad LFF da Silva PA Vargas 《Oral diseases》2011,17(3):258-264
Oral Diseases (2011) 17 , 258–264 Objective: To analyse and compare the expression of Palate, Lung, and Nasal Epithelium Clone (PLUNC) proteins in salivary glands from patients with and without AIDS (control group) using autopsy material. Methods: We analysed the expression of PLUNCs using immunohistochemistry in parotid (n = 45), submandibular (n = 47) and sublingual gland (n = 37) samples of AIDS patients [30 with normal histology, 21 with mycobacteriosis, 14 with cytomegalovirus (CMV) infection, 30 with chronic non‐specific sialadenitis, and 30 HIV‐negative controls. In situ hybridization (ISH) for SPLUNC 2 in the HIV‐negative group was performed. Results: SPLUNC 1 expression was detected in the mucous acini of submandibular and sublingual glands, and SPLUNC 2 were seen in the serous cells. LPLUNC 1 expression was only positive in the salivary ducts. There was a higher expression of SPLUNC 2 in AIDS patients with CMV infection and mycobacteriosis when compared with all other groups. The intensity of staining for SPLUNC 2 was greater around the lesions than the peripheral ones. ISH for SPLUNC 2 showed perinuclear positivity in the serous cells in all HIV‐negative cases. Conclusions: SPLUNC 1 and LPLUNC 1 proteins were similarly expressed in the salivary glands of AIDS patients and non‐HIV patients. CMV infection and mycobacteriosis increase SPLUNC 2 expression in serous cells in the salivary gland of AIDS patients. 相似文献
715.
Deminice R Vannucchi H Simões-Ambrosio LM Jordao AA 《European journal of applied physiology》2011,111(11):2663-2670
The aim of this study was to evaluate the effect of creatine supplementation on homocysteine (Hcy) metabolism after acute
aerobic and anaerobic exercise. A total of 112 Wistar rats were divided into four groups: aerobic exercise (A), aerobic exercise
plus creatine supplementation (ACr), anaerobic exercise (An), and anaerobic exercise plus creatine-supplemented (AnCr). Creatine
supplementation consisted of the addition of 2% creatine monohydrate to the diet. After 28 days, the rats performed an acute
moderate aerobic exercise bout (1 h swimming with 4% of total body weight load) or an acute intense anaerobic exercise bout
(6 × 30-s vertical jumps into the water with a 30-s rest between jumps, with 50% of total body weight load). The animals were
killed before (pre) and at 0, 2, and 6 h (n = 8) after acute exercise. Plasma Hcy concentration increased significantly (P < 0.05) up to 2 h after anaerobic exercise (An group: pre 8.7 ± 1.2, 0 h 13.2 ± 2.3, 2 h 13.5 ± 4.2, and 6 h 12.1 ± 2.2,
μmol/l). The same did not occur in acute aerobic exercised animals. Nevertheless, creatine supplementation significant decreased
(P < 0.05) homocysteine concentration independent of exercise intensity (AnCr group: pre 17%, 0 h 80%, 2 h 107%, and 6 h 48%;
ACr group: pre 17%, 0 h 19%, 2 h 28%, and 6 h 27%). Increased S-adenosylhomocysteine was also found in the An group. In conclusion, acute intense anaerobic exercise increased plasma Hcy
concentration. On the other hand, creatine supplementation decreased plasma Hcy independent of exercise intensity. 相似文献
716.
Hanekamp MN Mazer P van der Cammen-van Zijp MH van Kessel-Feddema BJ Nijhuis-van der Sanden MW Knuijt S Zegers-Verstraeten JL Gischler SJ Tibboel D Kollée LA 《Critical care (London, England)》2006,10(5):R127-11
Introduction
Extracorporeal membrane oxygenation (ECMO) is a supportive cardiopulmonary bypass technique for babies with acute reversible cardiorespiratory failure. We assessed morbidity in ECMO survivors at the age of five years, when they start primary school and major decisions for their school careers must be made. 相似文献717.
BM McDermott AA Mamun JM Najman GM Williams MJ O'Callaghan W Bor 《Acta paediatrica (Oslo, Norway : 1992)》2010,99(1):68-71
Aim: To report the stability of parent-perceived child irregular eating from 6 months to 14 years of age and to investigate a predictive model inclusive of child and parent factors.
Methods: Of the 7223 singleton children in a birth cohort, 5122 children were re-interviewed at 5 years and 4554 for the 14-year analysis. Information was obtained from structured interviews including questions answered by parents of the child at birth, 6 months, 5 years and 14 years; and by teenagers at age 14 years and from physical measures of the child. The mother's perception that the child was an irregular eater at age 14 years was the major outcome variable of interest.
Results: Approximately 40% of irregular eaters at age 5 will still be irregular eaters at age 14 years. This was not related to maternal education or socio-economic class. Significant at multivariate analysis were infant feeding problems and the children's ability to regulate their sleep and mood. Significant maternal factors were greater age, not feeling positive about the baby and persistent maternal anxiety during the child's early years.
Conclusion: Irregular eating behaviour displays considerable continuity from childhood to mid-adolescence. Independent contributions to this behavioural phenotype include child biological and psychological factors and maternal anxiety during the child's early years. 相似文献
Methods: Of the 7223 singleton children in a birth cohort, 5122 children were re-interviewed at 5 years and 4554 for the 14-year analysis. Information was obtained from structured interviews including questions answered by parents of the child at birth, 6 months, 5 years and 14 years; and by teenagers at age 14 years and from physical measures of the child. The mother's perception that the child was an irregular eater at age 14 years was the major outcome variable of interest.
Results: Approximately 40% of irregular eaters at age 5 will still be irregular eaters at age 14 years. This was not related to maternal education or socio-economic class. Significant at multivariate analysis were infant feeding problems and the children's ability to regulate their sleep and mood. Significant maternal factors were greater age, not feeling positive about the baby and persistent maternal anxiety during the child's early years.
Conclusion: Irregular eating behaviour displays considerable continuity from childhood to mid-adolescence. Independent contributions to this behavioural phenotype include child biological and psychological factors and maternal anxiety during the child's early years. 相似文献
718.