全文获取类型
收费全文 | 18078篇 |
免费 | 1368篇 |
国内免费 | 520篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 682篇 |
妇产科学 | 568篇 |
基础医学 | 1166篇 |
口腔科学 | 82篇 |
临床医学 | 1726篇 |
内科学 | 6992篇 |
皮肤病学 | 82篇 |
神经病学 | 439篇 |
特种医学 | 213篇 |
外国民族医学 | 1篇 |
外科学 | 624篇 |
综合类 | 2705篇 |
现状与发展 | 4篇 |
预防医学 | 1100篇 |
眼科学 | 62篇 |
药学 | 2338篇 |
7篇 | |
中国医学 | 923篇 |
肿瘤学 | 245篇 |
出版年
2023年 | 215篇 |
2022年 | 279篇 |
2021年 | 551篇 |
2020年 | 488篇 |
2019年 | 493篇 |
2018年 | 527篇 |
2017年 | 560篇 |
2016年 | 578篇 |
2015年 | 554篇 |
2014年 | 932篇 |
2013年 | 1481篇 |
2012年 | 995篇 |
2011年 | 1068篇 |
2010年 | 850篇 |
2009年 | 846篇 |
2008年 | 936篇 |
2007年 | 900篇 |
2006年 | 746篇 |
2005年 | 639篇 |
2004年 | 647篇 |
2003年 | 599篇 |
2002年 | 450篇 |
2001年 | 419篇 |
2000年 | 386篇 |
1999年 | 333篇 |
1998年 | 290篇 |
1997年 | 276篇 |
1996年 | 200篇 |
1995年 | 178篇 |
1994年 | 175篇 |
1993年 | 157篇 |
1992年 | 151篇 |
1991年 | 138篇 |
1990年 | 98篇 |
1989年 | 115篇 |
1988年 | 117篇 |
1987年 | 113篇 |
1986年 | 104篇 |
1985年 | 138篇 |
1984年 | 131篇 |
1983年 | 71篇 |
1982年 | 115篇 |
1981年 | 106篇 |
1980年 | 122篇 |
1979年 | 102篇 |
1978年 | 80篇 |
1977年 | 73篇 |
1976年 | 64篇 |
1973年 | 63篇 |
1970年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 671 毫秒
21.
22.
目的运用siRNA技术在肝癌细胞株中建立稳定低表达人胰岛素样生长因子1类受体(IGF1R)基因的细胞株。方法构建包含封闭IGF1R基因的真核表达载体pSUPER-IGF1R-siRNA,转染SMMC7721和Hep3B细胞,G418筛选表达稳定的细胞株。通过RT-PCR、Western-blot分析与鉴定IGF1R mRNA和蛋白及cyclin D1、cyclinB1蛋白的表达,并绘制细胞生长曲线。结果在SMMC7721和Hep3B细胞中成功建立低表达IGF1R基因的细胞株,其生长明显减慢(P<0.05),且其cyclinD1表达亦明显下降(P<0.05)。结论pSUPER-IGF1R-siRNA能抑制SMMC7721和Hep3B细胞的生长。 相似文献
23.
Myriam Costa Stphanie Potvin Imane Hammana Arnaud Malet Yves Berthiaume Alphonse Jeanneret Annick Lavoie Rene Lvesque Joëlle Perrier Danielle Poisson Antony D. Karelis Jean-Louis Chiasson Rmi Rabasa-Lhoret 《Journal of cystic fibrosis》2007,6(6):376-383
BACKGROUND: Abnormal glucose tolerance is a frequent co-morbidity in cystic fibrosis patients (CF), and is associated with a worse prognosis. The objectives are to investigate (a) the relative contribution of insulinopenia and insulin resistance (IR) for glucose tolerance and (b) the association between various glucose parameters and CF clinical status. METHODS: Oral glucose tolerance tests were performed in 114 consecutive CF patients not known to be diabetic as well as 14 controls similar for age and BMI. RESULTS: Abnormal glucose tolerance was found in 40% of patients with CF: 28% had impaired glucose tolerance (IGT) and 12% had new cystic fibrosis related diabetes (CFRD). Compared to control subjects, all CF patients were characterized by an increased glucose excursion (AUC). While reduced early insulin release characterised CF, IGT and CFRD patients also present IR thus both mechanisms significantly contribute to glucose tolerance abnormalities. Increased glucose AUC and reduced early insulin release but not glucose tolerance categories were associated with a reduced pulmonary function (FEV(1)). CONCLUSION: In CF, early insulin secretion defect but also IR contribute to glucose intolerance. Early in the course of the disease, increased glucose AUC and reduced early insulin secretion are more closely associated with a worse clinical status than conventional glucose tolerance categories. 相似文献
24.
糖尿病患者甘油三酯/高密度脂蛋白胆固醇比值水平与胰岛素抵抗的关系 总被引:2,自引:1,他引:1
目的探讨血清甘油三酯/高密度脂蛋白胆固醇(TG/HDL-C)比值水平与胰岛素抵抗的关系。方法对146例2型糖尿病患者测定空腹胰岛素(FINS)、空腹血糖(FBG),TG,HDL-C,低密度脂蛋白胆固醇(LDL-C)水平,计算TG/HDL-C比值,并按TG/HDL-C和FBG水平分组,比较组间差异与胰岛素抵抗指数(HOMA-IR)的关系。结果糖尿病组TG/HDL-C比值水平(2.531±3.741)显著高于正常对照组(0.898±0.487),差异有显著性(t=4.279,P<0.001)。TG/HDL-C比值增高组HOMA-IR(3.291±2.004)明显高于TG/HDL-C比值正常组(2.403±1.789),差异有显著性(t=2.796,P<0.01)。血糖水平>10 mmol/L组HOMA-IR(3.575±2.216)明显大于血糖水平≤10mmol/L组(2.384±1.584),差异有显著性(t=3.760,P<0.001)。结论糖尿病患者TG/HDL-C比值水平与胰岛素抵抗存在着密切的相关性。 相似文献
25.
B. Hagander J. Holm† N.-G. Asp† S. Efendi‡ I. Lundquist§ P. Nilsson-Ehle B. Scherstén 《Journal of human nutrition and dietetics》1988,1(4):239-246
Test meals with 10.9 g dietary fibre from sugar beet and corresponding control meals were given to eight healthy subjects, aged 67 ± 9 years. The postprandial glucose, triglyceride, hormone and glycerol responses were monitored during 3 hours. After the beet fibre meal the insulin and C-peptide areas were reduced by 28 ( P < 0.01) and 22% ( P > 0.025), respectively, and the somatostatin levels increased by approximately 30% ( P > 0.05). Further, the maximum relative postprandial reduction of plasma glycerol levels was less evident after the fibre-rich meal than after the control meal (36 ± 4% v. 46 ± 4%, P < 0.05). There was no apparent difference in the overall glycaemic response between the meals. The triglyceride levels were similar after both test meals.
Suspension of beet fibre bread given to rats by oro-gastric intubation induced lower blood glucose response than a control bread at 15 and 30 min ( P < 0.001), respectively, but a similar insulin response.
The results suggest an effect of beet fibre on the rate of carbohydrate absorption, expressed as a lower insulin response in the healthy volunteers and a reduced glucose response in the rat.
The mechanism behind this effect in healthy subjects could possibly be mediated by an increased somatostatin response. 相似文献
Suspension of beet fibre bread given to rats by oro-gastric intubation induced lower blood glucose response than a control bread at 15 and 30 min ( P < 0.001), respectively, but a similar insulin response.
The results suggest an effect of beet fibre on the rate of carbohydrate absorption, expressed as a lower insulin response in the healthy volunteers and a reduced glucose response in the rat.
The mechanism behind this effect in healthy subjects could possibly be mediated by an increased somatostatin response. 相似文献
26.
27.
为有效开展糖尿病基因治疗,作为第一步,本研究构建了人胰岛素原基因与表达载体PRC/CMV的重组体。首先,从质粒PBCA中酶切回收260bp的人胰岛素原基因片段,利用中间载体PBS.SK构建了含人胰岛素原基困片段的过渡质粒PBS.INS,在此基础上构建了真核细胞表达的人胰岛素基因重组体PRC/CMV.INS。 相似文献
28.
29.
Peter R. Ellis Victoria J. Burley Anthony R. Leeds David B. Peterson† 《Journal of human nutrition and dietetics》1988,1(2):77-84
We have developed a guar wholemeal bread and tested its physiological efficacy and sensory qualities. The objective of the study was to estimate the optimum concentration of guar in bread required to reduce postprandial glycaemia and insulinaemia without adversely affecting the quality of the bread. Following overnight fasts, 15 normal weight, non-diabetic subjects consumed meals of wholemeal bread alone (controls) and supplemented with guar at three different concentrations (5, 10 and 15% replacement of wheat flour). Blood samples for glucose and insulin analysis were taken preprandially, and at 30 and 60 min after the start of each meal. The acceptability of the wholemeal control and guar breads was assessed using a hedonic scaling method. A significantly lower blood glucose rise at 30 min was found after the 15% guar bread meal compared to the control. Plasma insulin responses at 30 and 60 min were significantly lower after the 10 and 15% guar bread meals compared to the controls. Hedonic scores indicated that the subjects found the 5 and 10% guar breads acceptable and in the case of the 5% variety the mean score was identical to the control. We suggest that a guar concentration of between 5 and 10% replacement of wheat flour (wholemeal or white) should be used for the baking of guar wholemeal bread but further work is needed to define the precise quantity of guar required. 相似文献
30.