全文获取类型
收费全文 | 1220篇 |
免费 | 88篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 30篇 |
妇产科学 | 16篇 |
基础医学 | 184篇 |
口腔科学 | 78篇 |
临床医学 | 90篇 |
内科学 | 312篇 |
皮肤病学 | 29篇 |
神经病学 | 98篇 |
特种医学 | 45篇 |
外科学 | 93篇 |
综合类 | 4篇 |
一般理论 | 2篇 |
预防医学 | 63篇 |
眼科学 | 42篇 |
药学 | 94篇 |
中国医学 | 1篇 |
肿瘤学 | 132篇 |
出版年
2023年 | 8篇 |
2022年 | 32篇 |
2021年 | 44篇 |
2020年 | 25篇 |
2019年 | 32篇 |
2018年 | 49篇 |
2017年 | 30篇 |
2016年 | 33篇 |
2015年 | 50篇 |
2014年 | 57篇 |
2013年 | 62篇 |
2012年 | 101篇 |
2011年 | 93篇 |
2010年 | 47篇 |
2009年 | 49篇 |
2008年 | 67篇 |
2007年 | 84篇 |
2006年 | 81篇 |
2005年 | 66篇 |
2004年 | 54篇 |
2003年 | 45篇 |
2002年 | 30篇 |
2001年 | 11篇 |
2000年 | 19篇 |
1999年 | 8篇 |
1998年 | 13篇 |
1997年 | 11篇 |
1996年 | 9篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 12篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 8篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1984年 | 3篇 |
1983年 | 8篇 |
1982年 | 2篇 |
1979年 | 7篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1973年 | 2篇 |
1971年 | 3篇 |
1968年 | 2篇 |
1966年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有1318条查询结果,搜索用时 15 毫秒
1.
2.
3.
Dr. Paolo Bechi Rosanna Del Andrea Amorosi Giovanna Marcuzzo Camillo Cortesini 《Digestive diseases and sciences》1992,37(3):378-384
The relationships between gastric pH and Helicobacter pylori infection were studied in 37 consecutive subjects affected with nonulcer dyspepsia. Each underwent esophagogastroduodenoscopy with multiple gastric biopsies for both H. pylori and histologic assessment, and 24-hr antral pH monitoring. H. pylori was harbored by 59.5% of the subjects with whole gastric spread of infection in all but one patient. Histologic gastritis was shown in 70.3% of the subjects. H. pylori was strongly associated with gastritis, both antral nonatrophic and multifocal atrophic. The ranges of 24-hr pH values were 1.3-6.9 in the H. pylori-positive and 1.2-6.8 in the H. pylori-negative group. Differences in pH values between the two groups were not significant. Moreover, the mean percent time duration of pH above 2, 4, and 6 did not significantly differ between the two groups. Therefore, this study has shown that chronic H. pylori infection is not related to luminal gastric pH. 相似文献
4.
P Pratesi E Grana M G Santagostino Barbone M I La Rotonda C Silipo A Vittoria 《Il Farmaco; edizione scientifica》1986,41(5):336-345
Proceeding in our study on the muscarinic receptor site, a refinement of its topology by means of Quantitative Structure-Activity Relationships has been carried out. Specific key structures have been selected considering not only muscarine and the corresponding desether derivative, but also a set of cyclopentenyltrimethylammoniummethyl salts. These derivatives, considered in a correlation equation extended to all of the five-membered cyclic structures previously examined, significantly improve understanding of contributions of critical ligand substructures to the overall interaction. The results obtained reinforce the reliability of correlation equations in structure-activity studies. 相似文献
5.
Giuseppina Mariucci Michela Tantucci Antonio Giuditta Maria Vittoria Ambrosini 《Neuroscience letters》2007
Transient focal ischemia induced in rat brain by occlusion of the middle cerebral artery (MCAo) elicits a generalized induction of the 72 kDa heat-shock protein (hsp72) heralding functional recovery. As this effect implies activation of protein synthesis, and local systems of protein synthesis are present in brain synapses, and may be analyzed in preparations of brain synaptosomes, we evaluated hsp72 expression and protein synthesis in synaptosomal fractions of spontaneously hypertensive rats (SHRs) subjected to permanent MCAo. SHRs were randomly divided in ischemics and sham controls, anaesthesia controls and passive controls. Focal ischemia was induced under chloral hydrate anaesthesia by unilateral permanent MCAo. Protein synthesis was determined by [35S]methionine incorporation into synaptosomal proteins from ischemic and contralateral cortex/striatum, and from cerebellum. Hsp72 expression was measured in the same fractions by immunoblotting. Our data demonstrate that under these conditions synaptic hsp72 markedly increases in the ischemic hemisphere 1 and 2 days after MCAo, progressively declining in the following 2 days, while no significant change occurs in control rats. In addition, in the ischemic hemisphere the rate of synaptic protein synthesis increases more than two-fold between 1 and 4 days after MCAo, without showing signs of an impending decline. The present data provide the first demonstration that synaptic protein synthesis is massively involved in brain plastic events elicited by permanent focal ischemia. 相似文献
6.
Domenico Ribatti Renato Contino Fabio Quondamatteo Vittoria Formica Alfredo Tursi 《Anatomy and embryology》1992,186(3):241-244
Summary Two mast cell populations, connective tissue mast cells (CTMCs) and mucosal mast cells, (MMCs) containing different proteoglycans in their granules, can be distinguished in several animal species by means of histochemical methods. In this study we documented the presence of these two types of mast cell in the chick embryo lung, from the 15th incubation day for the MMCs, and from the 18th incubation day for the CTMCs. Lungs of embryos treated with compound 48/ 80, which produces degranulation of the CTMCs, showed a decrease in the number of this type of mast cell and an unchanged number of MMCs. In the lungs of embryos treated with dexamethasone, which degranulates MMCs, a reduction in the number of these cells and an unchanged number of the CTMs were found. 相似文献
7.
Brunetti-Pierri N Andreucci MV Tuzzi R Vega GR Gray G McKeown C Ballabio A Andria G Meroni G Parenti G 《American journal of medical genetics. Part A》2003,(2):164-168
Partial trisomy of the long arm of chromosome 10 is a well-defined but rare syndrome. Clinical features of this chromosomopathy are a distinctive dysmorphic appearance, developmental delay, growth retardation, and in some cases, abnormalities of the extremities and renal, cardiac and ocular anomalies. This report describes a neonate with symmetric growth retardation and multiple dysmorphic features, in whom chromosomal analysis revealed a partial trisomy of chromosome 10q with a monosomy of the 13q34 region. The phenotype shares many common features with previously published cases. In addition to the typical features, our case also shows renal hypoplasia with early renal insufficiency and some genital anomalies. 相似文献
8.
Alfredo Vittoria Tiziana Cocca Elena La Mura Aldo Cecio 《Anatomical record (Hoboken, N.J. : 2007)》1992,233(1):18-24
The aim of this study is to describe the presence of neuroendocrine (NE) cells (paraneurons), producing biogenic amines and/or peptidergic hormones, in the female urethra of cattle, sheep, pigs, and horses, by means of histochemical and double labeling immunofluorescent techniques. 5-Hydroxytryptamine-, chromogranin A-, cholecystokinin- and somatostatin-containing NE cells are present in the urethral epithelium of all the species studied, with the unique exception of the lack of somatostatin cells in the horse. Paraneurons containing 5-hydroxytryptamine colocalized with chromogranin A or cholecytokinin were also found in all subjects. Such active substances are hypothesized to play a role in the contraction of the urethral musculature, emission of urogenital fluids, and inhibition of endocrine and exocrine secretions. © 1992 Wiley-Liss, Inc. 相似文献
9.
Anthony J Sharp Paul E Polak Vittoria Simonini Shao X Lin Jill C Richardson Ernesto R Bongarzone Douglas L Feinstein 《Journal of neuroinflammation》2008,5(1):33
Background
The purinergic receptor P2x7 is expressed on myeloid cells as well as on CNS glial cells, and P2x7 activation has been shown to increase both glial and T-cell activation. These properties suggest a role in the development of autoimmune disease including multiple sclerosis. 相似文献10.