全文获取类型
收费全文 | 1452篇 |
免费 | 94篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 38篇 |
妇产科学 | 74篇 |
基础医学 | 205篇 |
口腔科学 | 77篇 |
临床医学 | 115篇 |
内科学 | 363篇 |
皮肤病学 | 24篇 |
神经病学 | 106篇 |
特种医学 | 55篇 |
外科学 | 123篇 |
综合类 | 5篇 |
一般理论 | 2篇 |
预防医学 | 68篇 |
眼科学 | 42篇 |
药学 | 120篇 |
中国医学 | 1篇 |
肿瘤学 | 132篇 |
出版年
2023年 | 9篇 |
2022年 | 29篇 |
2021年 | 54篇 |
2020年 | 29篇 |
2019年 | 39篇 |
2018年 | 63篇 |
2017年 | 34篇 |
2016年 | 35篇 |
2015年 | 52篇 |
2014年 | 62篇 |
2013年 | 78篇 |
2012年 | 112篇 |
2011年 | 109篇 |
2010年 | 51篇 |
2009年 | 53篇 |
2008年 | 81篇 |
2007年 | 100篇 |
2006年 | 93篇 |
2005年 | 82篇 |
2004年 | 68篇 |
2003年 | 53篇 |
2002年 | 45篇 |
2001年 | 19篇 |
2000年 | 26篇 |
1999年 | 17篇 |
1998年 | 17篇 |
1997年 | 13篇 |
1996年 | 10篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 3篇 |
1992年 | 14篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1981年 | 2篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有1557条查询结果,搜索用时 31 毫秒
1.
2.
3.
Resection and radical lymphadenectomy for lung cancer: prognostic significance of lymphatic metastases 总被引:1,自引:0,他引:1
From 1979 to 1987, 1103 thoracotomies were performed in patients with lung cancer: 824 (74.7%) radical resections, 141 (12.7%) palliative resections and 138 (12.5%) exploratory thoracotomies. Among the 965 patients who underwent resection, 539 patients were N0, 190 patients N1 and 236 patients N2. Among patients with N1 disease we observed more frequent hilar metastases in the more advanced tumors (p less than 0.05). In 84 out of the 232 N2 patients (36.2%; 13.4% of all patients) a skipping of all pulmonary sites was observed. The most commonly invaded mediastinal levels were the paratracheal nodes on the right and the aortic nodes on the left, followed by the subcarinal nodes. The greater the neoplastic involvement of pulmonary nodal sites, the higher the percentage of patients with N2 disease and the number of mediastinal levels with tumor cells (p less than 0.05). The 5-year survival rate is 60% for N0, 46% for N1 and 23% for N2 disease. There is no significant difference in survival between N2 and N1 + N2 patients. Metastatic involvement of both upper and lower mediastinal levels carries a poorer prognosis compared to involvement of one compartment only (p less than 0.02). Patients with findings of mediastinal metastatic involvement should be selected: studies on lymphatic metastases are useful to better establish surgical indications for N2 patients. 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.
Fadda G Muie A Rufini V Ardito G Revelli L Fiorino MC Capelli A 《Endocrine pathology》2000,11(4):373-377
Cystic lesions of the thyroid are common findings. Although many thyroid cysts are of benign, some cases of hemorrhagic degenerative
changes occur in neoplastic nodules, mostly follicular neoplasms and papillary carcinomas. The occurrence of hemorrhagic changes
in medullary carcinomas has never been documented with aspirative cytological and histological pictures to the best of our
knowledge. A case of medullary thyroid carcinoma with a large central hemorrhagic cyst is described, and the literature regarding
the pathogenesis of this regression and the occurrence of cystic neoplasms in the thyroid is reviewed. 相似文献
7.
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
8.
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
9.
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
10.
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