全文获取类型
收费全文 | 528篇 |
免费 | 85篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 43篇 |
妇产科学 | 11篇 |
基础医学 | 58篇 |
口腔科学 | 31篇 |
临床医学 | 108篇 |
内科学 | 126篇 |
皮肤病学 | 14篇 |
神经病学 | 24篇 |
特种医学 | 38篇 |
外科学 | 21篇 |
综合类 | 15篇 |
预防医学 | 43篇 |
眼科学 | 10篇 |
药学 | 36篇 |
肿瘤学 | 36篇 |
出版年
2024年 | 2篇 |
2023年 | 11篇 |
2021年 | 9篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 18篇 |
2017年 | 11篇 |
2016年 | 10篇 |
2015年 | 15篇 |
2014年 | 22篇 |
2013年 | 25篇 |
2012年 | 6篇 |
2011年 | 12篇 |
2010年 | 23篇 |
2009年 | 38篇 |
2008年 | 20篇 |
2007年 | 19篇 |
2006年 | 8篇 |
2005年 | 17篇 |
2004年 | 11篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 16篇 |
1998年 | 22篇 |
1997年 | 33篇 |
1996年 | 37篇 |
1995年 | 27篇 |
1994年 | 21篇 |
1993年 | 18篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 8篇 |
1989年 | 19篇 |
1988年 | 10篇 |
1987年 | 6篇 |
1986年 | 12篇 |
1985年 | 12篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1982年 | 10篇 |
1981年 | 6篇 |
1980年 | 10篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1965年 | 2篇 |
排序方式: 共有616条查询结果,搜索用时 13 毫秒
1.
AM Manganoni† C Farisoglio† G Tucci† F Facchetti‡ PG Calzavara Pinton† 《Journal of the European Academy of Dermatology and Venereology》2007,21(10):1333-1336
BACKGROUND: Development of more than one primary melanoma in a patient is a relatively uncommon but well-recognized phenomenon. Its frequency has ranged from 1.2% to 8.2% in several series. This subgroup of patients with multiple primary lesions has not been characterized sufficiently. We report the experience of the Melanoma Unit of University Hospital Spedali Civili of Brescia, Italy. METHOD: Study subjects were drawn from 1240 patients with histologically confirmed melanoma, including melanoma in situ. From this group, multiple melanomas developed in 47 patients (3.79%). Every one of our patients has been taught to perform self-examination of the skin to detect suspicious pigmented lesions. RESULTS: Of the 47 patients described in this study, 38 had two primary melanomas, 7 had three melanomas and 2 had 5 and 10 melanomas, respectively. Mean age at first diagnosis was 46.2 years. The majority of subsequent melanomas (74.5%) were removed within 5 years of the initial operation. Synchronous lesions were found in 10 patients. In male patients, the lesion appeared most frequently on the trunk; in female patients, melanoma appeared mostly on the lower extremities. The second primary melanomas developed in the same anatomic region from the first in 53.2% of our patients. The proportion of in situ to invasive melanomas was greater for the second melanomas compared with the first melanomas. Regarding invasive melanomas, the mean thickness of the first melanomas was 1.31 mm compared with 0.66 mm for the second ones. Dividing patients into two groups, of more and less than 50, it is highlighted that in older patients synchronous lesions appear more frequently (36.4% vs. 8.0%); the median time interval between sequential melanomas is longer (84 vs. 63.7 months); and the ratio between the primary and secondary melanoma mean thickness is lower (1.21 : 1.08 vs. 1.43 : 0.63 mm). CONCLUSIONS: The study confirms that second primary melanoma is usually thinner than the first lesion, and it is more common in the same region of the body as the initial melanoma. The highest risk for a second melanoma is during the first 5 years, but a much longer time interval of 28 years is possible. Continued medical follow-up with complete skin examinations seems prudent, but it is very important to promote self-skin evaluation in patients to detect not only metastases but also subsequent primary melanomas in their earliest phases. 相似文献
2.
3.
4.
Pathways to care for alcohol use disorders 总被引:1,自引:0,他引:1
5.
6.
7.
Heterogeneity in the ultrastructure of the mucous (goblet) cells of the rabbit palpebral conjunctiva
Aim: The purpose of this study was to assess objectively the ultrastructure of the secretory granules in rabbit conjunctival mucin‐producing ‘goblet’ cells. Method: The upper eyelids from five young adult dioestrous female rabbits were dissected out, stretched onto a cardboard support and prepared for transmission electron microscopy by repeated application of an isotonic two per cent glutaraldehyde fixative at room temperature. Post‐fixation treatment included osmium tetroxide and staining with uranyl acetate and lead citrate. Low magnification micrographs were taken of the goblet cells of the conjunctiva, printed at a magnification of approximately 6,000 and the number, size and features of the secretory granules assessed. Results: Across the entire palpebral conjunctiva of ail five rabbits, the majority of mucous cells displayed a goblet shape and the secretory granules were uniformly pale in staining. The average width of the goblet cells was 10.8 ± 1.1 μm and the diameter of the secretory granules was 0.82 ± 0.16 μm. However, in localised regions across the palpebral conjunctiva of two of the rabbits, some goblet cells were different in that the secretory granules had either a denser‐staining core, in which some of the granules were densely staining (while others were pale) or most of the granules were densely staining. These mucous cells had an average diameter of 10.3 ± 1.7 μm and the granule diameters averaged 0.88 ± 0.01 μm. For these abnormal goblet cells, inflammatory cells were found in their immediate vicinity. Occasionally, goblet cells were seen to be in the process of degranulation with associated apparent cell necrosis and the mucin granule diameter was close to 1 μm. Conclusions: The ultrastructure of the mucin‐containing secretory granules of the conjunctival mucous cells is not necessarily homogeneous in character and further attention needs to be given to the effects of localised inflammation in the tissue and to possible hormonal influences. 相似文献
8.
9.
γ-去氢骆驼蓬碱等咔啉类生物碱的辐射防护作用 总被引:8,自引:0,他引:8
γ- Harmine(Ⅰ),’harmine(Ⅱ )and harmaline(Ⅲ )were isolated from PeganumHarmala L.( Zygophylaceae).Tests were conducted with mice to detect whether γ- harmine( a newcompound), harmine,harmof(Ⅳ)and harmalol(Ⅴ) are effective radioprotective compounds againstγ-ray irradiation, Intraperitoneal injection of the hydrochlorides of the four alkaloids 50~80mg·kg-1×1 in NIH male mice 30~45 minutes before 8.6~9. 7 Gy whole body 60Co irradiationsignificantly increased the survival effects(1. 33~2. 61)and 30-day survivai rate in comparison withcontrol mice.The results indicatethat γ- harmine exhibited relatively good radioprotective effect.γ-harmine is the first alkaloid isolated from a plant having ptotective effects against whole-body lethal irradiation in mice. 相似文献
10.
Role of transforming growth factor beta in peritoneal fibrosis 总被引:11,自引:0,他引:11
SUMMARY: Technique survival of peritoneal dialysis is seriously limited by the development of peritoneal fibrosis. the mesothelial cell layer lining the peritoneum is important in the pathogenesis of peritoneal fibrosis. Mesothelial cells are able to produce transforming growth factor beta (TGF-β), and respond to stimulation by this cytokine. In this review, we will detail the evidence available so far for the role of the complex interaction between TGF-β and mesothelial cells in the development of peritoneal fibrosis. 相似文献