全文获取类型
收费全文 | 5486篇 |
免费 | 369篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 90篇 |
妇产科学 | 75篇 |
基础医学 | 799篇 |
口腔科学 | 79篇 |
临床医学 | 532篇 |
内科学 | 1187篇 |
皮肤病学 | 88篇 |
神经病学 | 775篇 |
特种医学 | 469篇 |
外科学 | 672篇 |
综合类 | 60篇 |
一般理论 | 1篇 |
预防医学 | 276篇 |
眼科学 | 110篇 |
药学 | 321篇 |
中国医学 | 3篇 |
肿瘤学 | 288篇 |
出版年
2024年 | 7篇 |
2023年 | 61篇 |
2022年 | 85篇 |
2021年 | 163篇 |
2020年 | 91篇 |
2019年 | 121篇 |
2018年 | 133篇 |
2017年 | 127篇 |
2016年 | 149篇 |
2015年 | 156篇 |
2014年 | 202篇 |
2013年 | 260篇 |
2012年 | 414篇 |
2011年 | 429篇 |
2010年 | 250篇 |
2009年 | 203篇 |
2008年 | 368篇 |
2007年 | 369篇 |
2006年 | 348篇 |
2005年 | 309篇 |
2004年 | 304篇 |
2003年 | 242篇 |
2002年 | 240篇 |
2001年 | 80篇 |
2000年 | 61篇 |
1999年 | 73篇 |
1998年 | 66篇 |
1997年 | 61篇 |
1996年 | 31篇 |
1995年 | 25篇 |
1994年 | 28篇 |
1993年 | 21篇 |
1992年 | 32篇 |
1991年 | 40篇 |
1990年 | 30篇 |
1989年 | 32篇 |
1988年 | 28篇 |
1987年 | 26篇 |
1986年 | 24篇 |
1985年 | 30篇 |
1984年 | 21篇 |
1983年 | 19篇 |
1982年 | 16篇 |
1981年 | 5篇 |
1979年 | 18篇 |
1978年 | 12篇 |
1977年 | 7篇 |
1976年 | 11篇 |
1974年 | 5篇 |
1967年 | 4篇 |
排序方式: 共有5874条查询结果,搜索用时 15 毫秒
41.
Saleh A Wiedermann D Schroeter M Jonkmanns C Jander S Hoehn M 《NMR in biomedicine》2004,17(4):163-169
Brain inflammation contributes to the tissue injury caused by ischemic stroke. Macrophages as the most abundant inflammatory cell population in stroke lesions can be visualized using ultrasmall superparamagnetic iron oxide (USPIO) as a cell-specific contrast agent for magnetic resonance imaging (MRI). The aim of our present study was to delineate the inflammatory response during experimental cerebral infarction by means of USPIO-enhanced MRI and to correlate the spatial distribution of USPIO-induced MR signal alterations with cellular infiltration and iron deposition. To this end USPIOs were administered to Wistar rats 5 days after photothrombotic cerebral infarction. MR imaging at 7 T performed 24 h later displayed a rim-like signal loss around the infarction in the USPIO treated animals. On histological brain sections obtained from the same animals after MRI the distribution of iron and ED1+ phagocytes was in full spatial agreement with the signal loss seen on T2*-weighted images. Our study validates USPIO-enhanced MRI as an important tool for the noninvasive visualization of brain inflammation in stroke and other CNS pathologies. 相似文献
42.
43.
Balbo SL Mathias PC Bonfleur ML Alves HF Siroti FJ Monteiro OG Ribeiro FB Souza AC 《Research communications in molecular pathology and pharmacology》2000,108(5-6):291-296
In order to study the role of vagus nerve activity at the onset of obesity induced by monosodium glutamate (MSG), 30-day-old MSG-rats were vagotomized or sham operated. Body weight and food intake were recorded until animals were 90 days old and then sacrificed. Naso-anal length was recorded for all animals. Periepididymal and retroperitoneal fat pads were isolated and weighed. Reduction of body weight and naso-anal length were registered in 30-day-old MSG-rats. Obesity could also be observed, as increase of Lee index indicated. Results were most evident in 90-day-old MSG-rats. In both groups neither body weight gain nor food intake was changed by vagotomy. However, fat accumulation on tissues was reduced by vagotomy in MSG-rats. The results showed that MSG-obesity is not related to an increment in food intake behavior. Vagotonia might play a role at the onset of MSG-obesity. 相似文献
44.
45.
46.
47.
48.
Nowak KW Strowski MZ Switonska MM Kaczmarek P Singh V Fabis M Mackowiak P Nowak M Malendowicz LK 《International journal of molecular medicine》2005,15(6):969-972
Orexins are recently identified neuropeptides that appear to play a role in the regulation of energy homeostasis and arousal. They bind to and activate two closely related G protein-coupled receptors (OXR1 and OXR2), previously described as orphans. In this study we examined involvement of orexins in regulation of insulin secretion from rat pancreatic islets utilizing an in situ perfused pancreas and isolated pancreatic islet models. By means of RT-PCR we found that both OXR1 and OXR2 are expressed in rat pancreatic islets. Furthermore, the expression levels of OXR1 were higher than OXR2. In both experimental models applied, orexins A and B (1, 10 and 100 nmol/l) concentration dependently stimulated insulin secretion at two different glucose concentrations (6.66 or 26.4 mmol/l), with orexin A being more potent than orexin B. This study demonstrates that orexins A and B modulate insulin secretion in vitro. 相似文献
49.
Joachim Ktz Mathias Hahn Burkart Philipp Esen A. Bekturov Sarkyt E. Kudaibergenov 《Macromolecular chemistry and physics.》1993,194(2):397-410
Employing polyampholytes (inclusively polybetaines) of different chemical structure containing carboxylic groups and various basic nitrogen functions, homosymplex formation, as well as the competition between homo- and heterosymplex formation on addition of an appropriate polyelectrolyte, was investigated in dependence of pH and ionic strength by means of viscometry and turbidimetry. With most, but not with all, of the polyampholytes, the expected viscosity minimum at the isoelectric point, with its steepness depending on polyampholyte structure, was observed. Competition of homo- and heterosymplex formation at and near the isoelectric point is mainly governed by the pK values of the species involved, the level of zwitter-ion formation of the polyampholyte and the effect of non-Coulombic interactions, for example, via hydrogen bonds. 相似文献