全文获取类型
收费全文 | 2276篇 |
免费 | 359篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 62篇 |
妇产科学 | 342篇 |
基础医学 | 188篇 |
口腔科学 | 43篇 |
临床医学 | 928篇 |
内科学 | 231篇 |
皮肤病学 | 57篇 |
神经病学 | 84篇 |
特种医学 | 249篇 |
外科学 | 92篇 |
综合类 | 57篇 |
一般理论 | 1篇 |
预防医学 | 142篇 |
眼科学 | 6篇 |
药学 | 74篇 |
肿瘤学 | 85篇 |
出版年
2023年 | 43篇 |
2021年 | 10篇 |
2020年 | 37篇 |
2019年 | 28篇 |
2018年 | 64篇 |
2017年 | 94篇 |
2016年 | 79篇 |
2015年 | 110篇 |
2014年 | 114篇 |
2013年 | 111篇 |
2012年 | 56篇 |
2011年 | 82篇 |
2010年 | 110篇 |
2009年 | 111篇 |
2008年 | 61篇 |
2007年 | 69篇 |
2006年 | 68篇 |
2005年 | 53篇 |
2004年 | 54篇 |
2003年 | 63篇 |
2002年 | 50篇 |
2001年 | 62篇 |
2000年 | 43篇 |
1999年 | 67篇 |
1998年 | 101篇 |
1997年 | 113篇 |
1996年 | 108篇 |
1995年 | 96篇 |
1994年 | 67篇 |
1993年 | 51篇 |
1992年 | 29篇 |
1991年 | 28篇 |
1990年 | 21篇 |
1989年 | 42篇 |
1988年 | 42篇 |
1987年 | 28篇 |
1986年 | 31篇 |
1985年 | 33篇 |
1984年 | 25篇 |
1983年 | 18篇 |
1982年 | 28篇 |
1981年 | 13篇 |
1980年 | 20篇 |
1979年 | 5篇 |
1978年 | 24篇 |
1977年 | 21篇 |
1976年 | 14篇 |
1975年 | 13篇 |
1972年 | 4篇 |
1913年 | 3篇 |
排序方式: 共有2643条查询结果,搜索用时 234 毫秒
1.
2.
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
3.
4.
Monoclonal origin of vulvar intraepithelial neoplasia and some vulvar hyperplasias. 总被引:2,自引:1,他引:1 下载免费PDF全文
J. E. Tate G. L. Mutter K. A. Boynton C. P. Crum 《The American journal of pathology》1997,150(1):315-322
Squamous neoplasms of the female genital tract, including vulvar intraepithelial neoplasia, presumably are derived from a single cell. This study addressed this hypothesis and determined the clonal status of other squamous epithelial alterations associated with vulvar carcinoma, including hyperplasia and lichen sclerosis. X chromosome inactivation patterns of 22 epithelial lesions and matched normal epithelium were determined using a polymerase chain reaction (PCR)-based assay targeting the X-linked human androgen receptor gene (HUMARA). Clonality was inferred by comparing matched lesional and control tissues as follows: 1) monoclonal, if intensity of either PCR product was skewed relative to normal reference epithelium (control), 2) polyclonal, if both lesional and control were unskewed, and 3) unknown, if both lesion and control tissues were skewed toward the same allele. Two cases were excluded because of noninformative homozygous HUMARA alleles. Of 8 vulvar intraepithelial neoplasias analyzed, 7 were scored monoclonal and 1 polyclonal. Of 12 hyperplasias, 6 were monoclonal, including one with lichen sclerosis, 2 were polyclonal, and in 4, the clonal status could not be determined. The PCR-based clonal assay supports a monoclonal derivation for vulvar intraepithelial neoplasia and, in some cases, vulvar hyperplasia, and lichen sclerosis. The finding of monoclonal hyperplasia and lichen sclerosis suggests that clonal expansion may evolve before the development of morphological atypia in these epithelia. 相似文献
5.
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
6.
7.
8.
9.
M.M. Bialoskurski MA RN RM C.L. Cox MSc PhD RN & R.D. Wiggins PhD 《Journal of advanced nursing》2002,37(1):62-69
AIM: The aim of this study was to investigate the nature and organization of maternal needs and priorities in a neonatal unit. BACKGROUND: The relationship between maternal needs and priorities appears to be an under studied area in neonatal nursing. METHODS: A quantitative survey was carried out based on 209 mothers with premature infants. Two self-assessment schedules were used: critical care maternal needs inventory (J. Leske, Heart and Lung 15, 27-42) and a ranking scale. The data were analysed with multivariate analysis. FINDINGS: Data analysis revealed clear priorities in maternal needs. In particular the need for accurate infant related information was a priority for 93% of the mothers. Good communication practices with professionals were also valued. The mothers displayed altruistic behaviour, and self-related needs took second place. It is proposed that maternal needs demonstrate a hierarchical organization. CONCLUSION: It is important for nurses to consider the individual needs of the mothers, simply because the satisfaction of these needs is essential for maternal well-being. 相似文献
10.