全文获取类型
收费全文 | 1156篇 |
免费 | 88篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 16篇 |
妇产科学 | 14篇 |
基础医学 | 134篇 |
口腔科学 | 74篇 |
临床医学 | 111篇 |
内科学 | 264篇 |
皮肤病学 | 13篇 |
神经病学 | 70篇 |
特种医学 | 30篇 |
外科学 | 183篇 |
综合类 | 1篇 |
预防医学 | 45篇 |
眼科学 | 56篇 |
药学 | 138篇 |
中国医学 | 1篇 |
肿瘤学 | 76篇 |
出版年
2023年 | 13篇 |
2022年 | 25篇 |
2021年 | 62篇 |
2020年 | 23篇 |
2019年 | 42篇 |
2018年 | 45篇 |
2017年 | 37篇 |
2016年 | 30篇 |
2015年 | 47篇 |
2014年 | 42篇 |
2013年 | 61篇 |
2012年 | 101篇 |
2011年 | 116篇 |
2010年 | 60篇 |
2009年 | 48篇 |
2008年 | 77篇 |
2007年 | 60篇 |
2006年 | 48篇 |
2005年 | 44篇 |
2004年 | 36篇 |
2003年 | 43篇 |
2002年 | 33篇 |
2001年 | 13篇 |
2000年 | 14篇 |
1999年 | 13篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 13篇 |
1987年 | 11篇 |
1986年 | 7篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1967年 | 3篇 |
1965年 | 2篇 |
1957年 | 1篇 |
1946年 | 1篇 |
1943年 | 1篇 |
排序方式: 共有1249条查询结果,搜索用时 0 毫秒
1.
2.
A viscoelastic constitutive model for the periodontal ligament (PDL) capable of accounting for large strains, anisotropy, and inelastic time-dependent effects was developed. Anisotropy characteristics are determined by the composite nature of the tissue and, in particular, by the distribution of collagen fibres. Time-dependent viscous phenomena are due to microstructural modifications during loading, such as fluid fluxes moving through the solid matrix and the internal rearrangement of fibers and constitutive adaptation. The viscoelastic model presented here was implemented in a general purpose finite element code. In vitro experimental tests were carried out on the PDL specimens of adult pigs to obtain stress-relaxation and cyclic stress-strain curves. The comparison of experimental and numerical results revealed good correspondence and confirmed the capability of the formulation assumed to properly interpret the viscoelastic behavior of the PDL. 相似文献
3.
4.
Juliana Pavan Zuliani José María Gutiérrez Luciana Lyra Casais e Silva Sandra Coccuzzo Sampaio Bruno Lomonte Catarina de Fátima Pereira Teixeira 《Toxicon》2005,46(5):523-532
The in vitro effects of myotoxin III (MT-III), an Asp-49 catalytically-active phospholipase A(2), and myotoxin II (MT-II), a catalytically-inactive Lys-49 variant, isolated from Bothrops asper snake venom, on phagocytosis and production of hydrogen peroxide (H(2)O(2)) by thioglycollate-elicited macrophages were investigated. MT-II and MT-III were cytotoxic to mouse peritoneal macrophages at concentrations higher than 25 microg/ml. At non-cytotoxic concentrations, MT-II stimulated Fcgamma, complement, mannose and beta-glucan receptors-mediated phagocytosis, whereas MT-III stimulated only the mannose and beta-glucan receptors-mediated phagocytosis. Moreover, both myotoxins induced the release of H(2)O(2) by thioglycollate-elicited macrophages, MT-III being the most potent stimulator. MT-II induced the release of H(2)O(2) only at a concentration of 3.2 microg/ml (130% increment) while MT-III induced this effect at all concentrations tested (0.5-2.5 microg/ml; average of 206% increment). It is concluded that, at non-cytotoxic concentrations, MT-II and MT-III activate defense mechanisms in macrophages up regulating phagocytosis, mainly via mannose and beta-glucan receptors, and the respiratory burst. 相似文献
5.
Stella Regina Zamuner Juliana Pavan Zuliani Cristina Maria Fernandes José Maria Gutiérrez Catarina de Fátima Pereira Teixeira 《Toxicon》2005,46(7):806-813
Bothrops asper venom (BaV) causes systemic and local effects characterized by an acute inflammatory reaction with accumulation of leukocytes and release of endogenous mediators. In this study, the effects of BaV on the release of the cytokines IL-1, IL-6 and TNF-alpha and the eicosanoids LTB4 and TXA2 in the peritoneal cavity of mice were analyzed. We also investigated the participation of beta2 integrin chain, l-selectin, LFA-1, ICAM-1 and PECAM-1 adhesion molecules in the BaV-induced leukocyte accumulation. Levels of proinflammatory cytokines IL-6 and TNF-alpha, as well as eicosanoids LTB4 and TXA2 were significantly increased after BaV injection (250 microg/kg), whereas no increment in IL-1 was observed. Anti-mouse l-selectin, LFA-1, ICAM-1, PECAM-1 and beta2 integrin chain monoclonal antibodies resulted in a reduction of neutrophil accumulation induced by BaV injection compared with isotype-matched control injected animals. These data suggest that BaV is able to induce the activation of leukocytes and endothelium to express adhesion molecules involved in the recruitment of neutrophils into the inflammed site. Furthermore, these results showed that BaV induces the release of cytokines and eicosanoids in the local of the venom injection; these inflammatory mediators may be important for the initiation and amplification of the inflammatory reaction characteristic from Bothrops sp envenomation. 相似文献
6.
7.
Melanoma is a relentless type of skin cancer which involves myriad signaling pathways which regulate many cellular processes. This makes melanoma difficult to treat, especially when identified late. At present, therapeutics include chemotherapy, surgical resection, biochemotherapy, immunotherapy, photodynamic and targeted approaches. These interventions are usually administered as either a single-drug or in combination, based on tumor location, stage, and patients’ overall health condition. Howe... 相似文献
8.
9.
In the current landscape of endothelial cell isolation for building in vitro models of the blood-brain barrier, our work moves towards reproducing the features of the neurovascular unit to achieve glial compliance through an innovative biomimetic coating technology for brain chronic implants. We hypothesized that the autologous origin of human brain microvascular endothelial cells (hBMECs) is the first requirement for the suitable coating to prevent the glial inflammatory response triggered by foreign neuroprosthetics. Therefore, this study established a new procedure to preserve the in vitro viability of hBMECs isolated from gray and white matter specimens taken from neurosurgery patients. Culturing adult hBMECs is generally considered a challenging task due to the difficult survival ex vivo and progressive reduction in proliferation of these cells. The addition of 10 nM β-estradiol 17-acetate to the hBMEC culture medium was found to be an essential and discriminating factor promoting adhesion and proliferation both after isolation and thawing, supporting the well-known protective role played by estrogens on microvessels. In particular, β-estradiol 17-acetate was critical for both freshly isolated and thawed female-derived hBMECs, while it was not necessary for freshly isolated male-derived hBMECs; however, it did counteract the decay in the viability of the latter after thawing. The tumor-free hBMECs were thus cultured for up to 2 months and their growth efficiency was assessed before and after two periods of cryopreservation. Despite the thermal stress, the hBMECs remained viable and suitable for re-freezing and storage for several months. This approach increasing in vitro viability of hBMECs opens new perspectives for the use of cryopreserved autologous hBMECs as biomimetic therapeutic tools, offering the potential to avoid additional surgical sampling for each patient. 相似文献
10.