全文获取类型
收费全文 | 2055篇 |
免费 | 312篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 64篇 |
妇产科学 | 283篇 |
基础医学 | 125篇 |
口腔科学 | 27篇 |
临床医学 | 876篇 |
内科学 | 248篇 |
皮肤病学 | 51篇 |
神经病学 | 79篇 |
特种医学 | 241篇 |
外科学 | 59篇 |
综合类 | 58篇 |
预防医学 | 104篇 |
眼科学 | 8篇 |
药学 | 82篇 |
中国医学 | 1篇 |
肿瘤学 | 68篇 |
出版年
2024年 | 5篇 |
2023年 | 44篇 |
2022年 | 8篇 |
2021年 | 18篇 |
2020年 | 36篇 |
2019年 | 19篇 |
2018年 | 58篇 |
2017年 | 91篇 |
2016年 | 80篇 |
2015年 | 103篇 |
2014年 | 109篇 |
2013年 | 105篇 |
2012年 | 51篇 |
2011年 | 67篇 |
2010年 | 110篇 |
2009年 | 105篇 |
2008年 | 57篇 |
2007年 | 56篇 |
2006年 | 52篇 |
2005年 | 30篇 |
2004年 | 27篇 |
2003年 | 43篇 |
2002年 | 32篇 |
2001年 | 42篇 |
2000年 | 24篇 |
1999年 | 52篇 |
1998年 | 94篇 |
1997年 | 112篇 |
1996年 | 107篇 |
1995年 | 94篇 |
1994年 | 66篇 |
1993年 | 51篇 |
1992年 | 28篇 |
1991年 | 28篇 |
1990年 | 18篇 |
1989年 | 41篇 |
1988年 | 43篇 |
1987年 | 31篇 |
1986年 | 33篇 |
1985年 | 37篇 |
1984年 | 20篇 |
1983年 | 19篇 |
1982年 | 22篇 |
1981年 | 16篇 |
1980年 | 16篇 |
1979年 | 6篇 |
1978年 | 18篇 |
1977年 | 15篇 |
1976年 | 14篇 |
1975年 | 16篇 |
排序方式: 共有2376条查询结果,搜索用时 0 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.
To investigate the simultaneous effects of dexamethasone on peripheral and central adrenocorticotropic hormone (ACTH) systems, rats were treated with dexamethasone or saline for 4 days. Pituitary, plasma, hypothalamus and cerebrospinal fluid (CSF) were then collected and analyzed for ACTH immunoreactivity. Additionally, hypothalamic tissue extracts were analyzed for corticotropin-releasing hormone (CRH) immunoreactivity. Dexamethasone significantly lowered peripheral levels of ACTH as measured in pituitary and plasma. Hypothalamic ACTH content significantly increased while CSF ACTH significantly decreased with dexamethasone treatment. Hypothalamic CRH concentrations showed a small but statistically insignificant decrease. These results suggest that prolonged exposure to dexamethasone affects central as well as peripheral ACTH activity, corroborate our previous findings in rhesus monkeys of decreased CSF ACTH in response to prolonged dexamethasone treatment, suggest that dexamethasone may inhibit the release of ACTH from hypothalamic neurons into the CSF, and provide evidence that the effect of dexamethasone on pituitary ACTH content is of greater magnitude than its effect on hypothalamic CRH. 相似文献
4.
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
5.
6.
7.
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
8.
9.
10.
Stressful life events are commonly associated with the onset and maintenance of psychopathology and much research has focused on the role of the corticotropin-releasing factor (CRF) system in mediating psychopathology. Since CRF serves to integrate the stress response, it is possible that the CRF system plays a role as a neurochemical linkage between stress and psychopathology. CRF-binding protein (CRF-BP) is thought to modulate CRF activity by decreasing its actions. Therefore, in some psychopathological states, alterations in CRF-BP function may contribute to dysregulation of the CRF system. Since the amygdala CRF system mediates stress- and anxiety-related behaviors and alterations in amygdala function are associated with psychopathology, we examined amygdala CRF-BP gene expression in post-mortem brains from subjects with major depression, bipolar disorder, and schizophrenia as well as in controls. In addition to characterizing the anatomic distribution of CRF-BP mRNA in the human amygdala and medial temporal lobe region, we found a significant decrease in CRF-BP mRNA levels in the basolateral amygdala of male bipolar and male schizophrenic subjects and the lateral amygdala of male bipolar subjects. These results raise the possibility that men with decreased amygdala CRF-BP may be more vulnerable to the effects of stress exposure on the etiology or maintenance of bipolar disorder or schizophrenia. 相似文献