全文获取类型
收费全文 | 1024篇 |
免费 | 52篇 |
国内免费 | 59篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 54篇 |
妇产科学 | 21篇 |
基础医学 | 62篇 |
口腔科学 | 45篇 |
临床医学 | 144篇 |
内科学 | 252篇 |
皮肤病学 | 25篇 |
神经病学 | 32篇 |
特种医学 | 235篇 |
外科学 | 79篇 |
综合类 | 27篇 |
预防医学 | 28篇 |
眼科学 | 16篇 |
药学 | 71篇 |
中国医学 | 2篇 |
肿瘤学 | 41篇 |
出版年
2023年 | 4篇 |
2022年 | 2篇 |
2021年 | 13篇 |
2020年 | 8篇 |
2019年 | 6篇 |
2018年 | 20篇 |
2017年 | 12篇 |
2016年 | 11篇 |
2015年 | 25篇 |
2014年 | 26篇 |
2013年 | 34篇 |
2012年 | 30篇 |
2011年 | 26篇 |
2010年 | 31篇 |
2009年 | 30篇 |
2008年 | 18篇 |
2007年 | 55篇 |
2006年 | 16篇 |
2005年 | 24篇 |
2004年 | 24篇 |
2003年 | 12篇 |
2002年 | 7篇 |
2001年 | 20篇 |
2000年 | 12篇 |
1999年 | 19篇 |
1998年 | 55篇 |
1997年 | 35篇 |
1996年 | 63篇 |
1995年 | 45篇 |
1994年 | 41篇 |
1993年 | 51篇 |
1992年 | 17篇 |
1991年 | 18篇 |
1990年 | 23篇 |
1989年 | 34篇 |
1988年 | 39篇 |
1987年 | 36篇 |
1986年 | 25篇 |
1985年 | 31篇 |
1984年 | 18篇 |
1983年 | 10篇 |
1982年 | 12篇 |
1981年 | 22篇 |
1980年 | 19篇 |
1979年 | 7篇 |
1978年 | 10篇 |
1977年 | 15篇 |
1976年 | 9篇 |
1975年 | 9篇 |
1963年 | 1篇 |
排序方式: 共有1135条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
995.
996.
Background and purpose:
Earlier we reported that 7,8-dihydro-8-oxo-deoxyguanosine (8-oxo-dG), an oxidatively modified guanine nucleoside, exerted anti-inflammatory activity through inactivation of the GTP binding protein, Rac. In the present study, the effects of 8-oxo-dG were investigated on responses to antigen challenge in sensitized mice, as Rac is also involved at several steps of the immune process including antigen-induced release of mediators from mast cells.Experimental approach:
Mice were sensitized and challenged with ovalbumin without or with oral administration of 8-oxo-dG during the challenge. Effects of 8-oxo-dG were assessed by measuring lung function, cells and cytokines in broncho-alveolar lavage fluid (BALF) and serum levels of antigen-specific IgE. Rac activity in BALF cells was also measured.Key results:
8-oxo-dG inhibited the increased airway resistance and decreased lung compliance of sensitized and challenged mice to the levels of non-sensitized control mice and lowered the increased leukocytes particularly, eosinophils, in BALF. Furthermore, 8-oxo-dG suppressed allergy-associated immune responses, such as raised anti- ovalbumin IgE antibody in serum, increased expression of CD40 and CD40 ligand in lung, increased interleukin-4, -5, -13, interferon-γ and tumour necrosis factor-α in BALF and mRNA levels of these cytokines in BALF cells, dose-dependently. The corresponding purine, 8-oxo-guanine, showed no effects in the same experiments. Finally, 8-oxo-dG, but not 8-oxo-guanine, inhibited the increased Rac activity in sensitized and challenged mice.Conclusion and implications:
8-Oxo-dG had anti-allergic actions that might be mediated by Rac inactivation. This compound merits further evaluation of its therapeutic potential in allergic asthma. 相似文献997.
Mirabelli D Roberti S Gangemi M Rosato R Ricceri F Merler E Gennaro V Mangone L Gorini G Pascucci C Cavone D Nicita C Barbieri PG Marinaccio A Magnani C Montanaro F 《International journal of cancer. Journal international du cancer》2009,124(1):194-200
In some population-based studies, a shorter median survival was observed in peritoneal as compared with pleural, malignant mesothelioma, but in others, longer median survival times or higher proportions of long-term survivors were reported. Statistical instability could have caused these differences. We analyzed survival in peritoneal mesothelioma in a large and unselected population-based case series. Cases (338) registered from 1990 to 2001 by 9 Italian regional mesothelioma registries contributing to the network of the National Mesothelioma Registry were followed until December 31, 2005. Univariate (Kaplan-Meier) and multivariate (Cox proportional hazards regression) analyses of survival were performed according to selected individual characteristics, including limited treatment information in a subset of 194 cases. The results were compared with those obtained in a parallel study on pleural mesothelioma cases. Epithelioid histotype, younger age at diagnosis and, to a lesser degree, gender (women), and being diagnosed in a hospital with a thoracic surgery unit positively and significantly affected survival. The effect of treatment was positive but not statistically significant. No trend in the risk of death according to calendar period of diagnosis was present. Peritoneal mesothelioma cases had shorter median survival time than pleural cases, but a larger proportion of long-term survivors. Survival patterns after peritoneal and pleural mesothelioma differed markedly. Treatment was not associated with a statistically significant improvement in survival, but our study included cases first diagnosed before the introduction of the most recent therapeutic approaches. This provides a large historical comparison for future studies on survival trends at the population level. 相似文献
998.
Montanaro F Rosato R Gangemi M Roberti S Ricceri F Merler E Gennaro V Romanelli A Chellini E Pascucci C Musti M Nicita C Barbieri PG Marinaccio A Magnani C Mirabelli D 《International journal of cancer. Journal international du cancer》2009,124(1):201-207
A median survival time of about 9 months is generally reported among malignant pleural mesothelioma cases. Recently, better results in terms of survival and performance status have been reported in clinical trials that included highly selected patients. We describe the survival of pleural mesothelioma patients and the factors predictive of survival in an unselected, population-based setting. Pleural mesothelioma cases (4,100) registered from 1990 to 2001 by 9 Italian regional mesothelioma registries contributing to the network of the National Mesothelioma Registry were followed until December 31, 2005. Univariate (Kaplan-Meier) and multivariate (Cox proportional hazards regression) analyses of survival were carried out according to selected individual characteristics, including limited information on treatment in a subset of 578 cases. The median survival time was 9.8 months (95% confidence interval: 9.4-10.1). In multivariate analysis, younger age at diagnosis and epithelioid histotype were associated with significantly reduced hazard ratios. Positive effects of gender (women) and being diagnosed in a hospital with a thoracic surgery unit were of border-line statistical significance. No association with calendar period of diagnosis or asbestos exposure was present. Treatment was not associated with a statistically significant improvement in survival. This is the largest population-based study on survival in patients with pleural mesothelioma to date. Age and morphology were the main prognostic factors. Results regarding the effect of treatment were disappointing but may be useful to assess the future impact, at the population level, of recently introduced therapies. 相似文献
999.
Bongarzone S Tran HN Cavalli A Roberti M Carloni P Legname G Bolognesi ML 《Journal of medicinal chemistry》2010,53(22):8197-8201
A library of 11 entries, featuring a 2,5-diamino-1,4-benzoquinones nucleus as spacer connecting two aromatic prion recognition motifs, was designed and evaluated against prion infection. Notably, 6-chloro-1,2,3,4-tetrahydroacridine 10 showed an EC(50) of 0.17 μM, which was lower than that displayed by reference compound BiCappa. More importantly, 10 possessed the capability to contrast prion fibril formation and oxidative stress, together with a low cytotoxicity. This study further corroborates the bivalent strategy as a viable approach to the rational design of anti-prion chemical probes. 相似文献
1000.