全文获取类型
收费全文 | 2869篇 |
免费 | 389篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 81篇 |
妇产科学 | 296篇 |
基础医学 | 245篇 |
口腔科学 | 35篇 |
临床医学 | 1019篇 |
内科学 | 332篇 |
皮肤病学 | 68篇 |
神经病学 | 127篇 |
特种医学 | 259篇 |
外科学 | 157篇 |
综合类 | 90篇 |
一般理论 | 2篇 |
预防医学 | 208篇 |
眼科学 | 13篇 |
药学 | 122篇 |
肿瘤学 | 208篇 |
出版年
2023年 | 54篇 |
2022年 | 7篇 |
2021年 | 20篇 |
2020年 | 50篇 |
2019年 | 39篇 |
2018年 | 97篇 |
2017年 | 111篇 |
2016年 | 97篇 |
2015年 | 127篇 |
2014年 | 134篇 |
2013年 | 144篇 |
2012年 | 90篇 |
2011年 | 128篇 |
2010年 | 134篇 |
2009年 | 129篇 |
2008年 | 78篇 |
2007年 | 94篇 |
2006年 | 84篇 |
2005年 | 96篇 |
2004年 | 57篇 |
2003年 | 64篇 |
2002年 | 48篇 |
2001年 | 76篇 |
2000年 | 52篇 |
1999年 | 87篇 |
1998年 | 110篇 |
1997年 | 117篇 |
1996年 | 114篇 |
1995年 | 103篇 |
1994年 | 65篇 |
1993年 | 54篇 |
1992年 | 40篇 |
1991年 | 54篇 |
1990年 | 29篇 |
1989年 | 55篇 |
1988年 | 55篇 |
1987年 | 37篇 |
1986年 | 43篇 |
1985年 | 49篇 |
1984年 | 22篇 |
1983年 | 26篇 |
1982年 | 25篇 |
1981年 | 21篇 |
1980年 | 17篇 |
1979年 | 12篇 |
1978年 | 26篇 |
1977年 | 17篇 |
1976年 | 21篇 |
1975年 | 14篇 |
1971年 | 11篇 |
排序方式: 共有3273条查询结果,搜索用时 0 毫秒
1.
2.
3.
D Van Neste† RM Trüeb‡ 《Journal of the European Academy of Dermatology and Venereology》2006,20(5):578-583
BACKGROUND: Computer-assisted image analysis has been proposed for human hair growth studies. METHODS: The performances of Trichoscan, a commercially available automated system combining epiluminiscence microscopy with digital image analysis, developed for office-based hair growth measurements, have been evaluated comparatively on the same skin sites using standardized photographic equipment and calibrated processing for contrast-enhanced phototrichogram (CE-PTG) analysis. This reference method has been validated with scalp biopsies and histological examination of serial sectioning. RESULTS: Besides edge effects, hair fibres escaped the Trichoscan analysis for various reasons including, but not limited to, thickness, pigmentation, closeness and crossing. CONCLUSION: Most of these problems have been identified in the late 1980s and remain largely unsolved by the processing software that was evaluated in 2004. Therefore claims promoting the Trichoscan method for accurate hair measurements in clinical trials on scalp and body hair are not supported by the present investigation. The speed at which the analysis is performed is outweighed by the errors in signal detection. Therefore we suggest that improvements must be clearly documented before Trichoscan is established for quantified diagnostic purposes and detailed hair cycle monitoring during hair trials. 相似文献
4.
5.
The junctional zone (Jz) of the mouse placenta consists of two main trophoblast populations, spongiotrophoblasts and glycogen cells (GCs), but the development and function of both cell types are unknown. We conducted a quantitative analysis of GC size, number, and invasion of cells into the decidua across gestation. Furthermore, we identified markers of GC function to investigate their possible roles in the placenta. While the spongiotrophoblast cell volume doubles, and cell number increases steadily from E12.5 to E16.5, there is a remarkable 80-fold increase in GC numbers. This finding is followed by a notable decrease by E18.5. Surprisingly, the accumulation of GCs in the decidua did not fully account for the decrease in GC number in the Jz, suggesting loss of GCs from the placenta. Glucagons were detected on GCs, suggesting a steady glucose release throughout gestation. Connexin31 staining was shown to be specific for GCs. GC migration and invasion may be facilitated by temporally regulated expression of matrix metalloproteinase 9 and the imprinted gene product, Decorin. Expression of the clearance receptor for type II insulin-like growth factor (IGF-II), IGF2R, in a short developmental window before E16.5 may be associated with regulating the growth effects of IGF-II from glycogen cells and/or labyrinthine trophoblast on the expansion of the Jz. Thus stereology and immunohistochemistry have provided useful insights into Jz development and function of the glycogen cells. 相似文献
6.
7.
V Schleyer† S Radakovic-Fijan‡ S Karrer† T Zwingers§ A Tanew‡ M Landthaler† RM Szeimies† 《Journal of the European Academy of Dermatology and Venereology》2006,20(7):823-828
BACKGROUND: Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials. OBJECTIVE: A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis. METHODS: In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm(2) and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI). RESULTS: The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation. CONCLUSION: Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile. 相似文献
8.
9.
10.
As more patients survive cancer, and as more sophisticated multidrug antineoplastic protocols are developed, the chances of an anesthesiologist's coming into contact with patients who have been treated with such protocols are increasing. The anesthesiologist who must administer anesthesia to a patient who has had chemotherapy must be cognizant of the particular antineoplastic agents that have the potential for producing occult pulmonary dysfunction. Anesthetic management of these cases must be carefully planned and titrated to prevent further lung injury. 相似文献