全文获取类型
收费全文 | 1078篇 |
免费 | 64篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 54篇 |
妇产科学 | 22篇 |
基础医学 | 146篇 |
口腔科学 | 70篇 |
临床医学 | 87篇 |
内科学 | 192篇 |
皮肤病学 | 37篇 |
神经病学 | 75篇 |
特种医学 | 15篇 |
外科学 | 119篇 |
综合类 | 20篇 |
一般理论 | 1篇 |
预防医学 | 81篇 |
眼科学 | 38篇 |
药学 | 88篇 |
中国医学 | 6篇 |
肿瘤学 | 84篇 |
出版年
2023年 | 10篇 |
2022年 | 10篇 |
2021年 | 40篇 |
2020年 | 13篇 |
2019年 | 38篇 |
2018年 | 44篇 |
2017年 | 21篇 |
2016年 | 27篇 |
2015年 | 25篇 |
2014年 | 42篇 |
2013年 | 53篇 |
2012年 | 98篇 |
2011年 | 85篇 |
2010年 | 48篇 |
2009年 | 43篇 |
2008年 | 59篇 |
2007年 | 69篇 |
2006年 | 68篇 |
2005年 | 47篇 |
2004年 | 36篇 |
2003年 | 41篇 |
2002年 | 44篇 |
2001年 | 12篇 |
2000年 | 8篇 |
1999年 | 11篇 |
1998年 | 5篇 |
1995年 | 6篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 8篇 |
1985年 | 5篇 |
1984年 | 8篇 |
1983年 | 10篇 |
1982年 | 4篇 |
1980年 | 5篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 4篇 |
1970年 | 6篇 |
1969年 | 3篇 |
1968年 | 4篇 |
1967年 | 9篇 |
1965年 | 9篇 |
排序方式: 共有1143条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
Vidya P Kulkarni Kaiwen Lin Selim R Benbadis 《Journal of clinical neurophysiology》2007,24(6):433-437
The definition of the persistent vegetative state (PVS) is relatively straightforward, but its diagnosis can be challenging. We reviewed a series of EEG performed in patients with PVS to assess the diagnostic value of EEG. We reviewed records of all hospital patients with a diagnosis of persistent vegetative PVS. EEG findings included normal, continuous generalized slowing, intermittent generalized slowing, background slowing, background suppression, alpha, generalized periodic pattern, PLEDS, and triphasic waves. EEG findings had no association with etiology and varied from one pattern to another in the same patients' EEGs obtained at different times (see table). We conclude that EEG findings in PVS are heterogeneous and too variable to be of diagnostic value. 相似文献
6.
7.
The present study deals with the in vitro and in vivo effects of methyl isocyanate (MIC) on rat brain mitochondrial function. Addition of MIC to tightly coupled brain mitochondria in vitro resulted in a mild stimulation of state 4 respiration, abolition of respiratory control, decrease in ADP/O ratio, and inhibition of state 3 oxidation. The oxidation of NAD+-linked substrates (glutamate + malate) was more sensitive (fourfold) to the inhibitory action of MIC than succinate while cytochrome oxidase was unaffected. Administration of MIC subcutaneously at a lethal dose affected respiration only with glutamate + malate as the substrate (site I) and caused a 20% decrease in state 3 oxidation leading to a significant decrease in respiratory control index while state 4 respiration and ADP/O ratio remained unaffected. As both the malondialdehyde and iron contents of brain mitochondria were not altered, it may be inferred that the observed in vivo inhibition of state 3 oxidation is induced by MIC through systemic stagnant hypoxia leading to ischemia of brain, which further contributes to the cerebral hypoxia. 相似文献
8.
Nitric oxide (NO) is a physiological species involved in inhibition of platelet adhesion and aggregation. A novel NO delivery device was utilized to quantitatively assess the effects of gaseous NO on platelet deposition to agonist-coated biomaterials in the presence of a platelet suspension. Platelet deposition was evaluated as a function of agonist (collagen, fibrinogen, or IgG), shear rate (250, 500, and 750 s–1), and perfusion time (5, 7.5, and 15 min). The minimal aqueous surface NO concentrations and fluxes necessary for significant inhibition of platelet deposition were quantified. Platelet deposition was completely inhibited at a gaseous NO exposure of 0.1 ppm, irrespective of the platelet agonist, shear rate, and perfusion time. The corresponding aqueous surface NO concentration was 0.09 nM at 250 s–1 as predicted by a validated model. Surface fluxes ranged between 0.3 and 0.6 femtomoles cm–2 s–1. The results of this study are useful for establishing generalized guidelines (i.e., NO flux requirements in the presence of agonists, shear rate, and perfusion time) for the design and development of suitable biomaterials incorporating NO to reduce platelet deposition. Further studies incorporating blood, rather than platelet suspensions, are required to provide a more complete assessment of the required NO flux necessary to inhibit platelet deposition. © 2000 Biomedical Engineering Society.
PAC00: 8717-d, 8719Tt 相似文献
9.
Conversion of myoblasts to physiologically active neuronal phenotype 总被引:13,自引:0,他引:13
Watanabe Y Kameoka S Gopalakrishnan V Aldape KD Pan ZZ Lang FF Majumder S 《Genes & development》2004,18(8):889-900
10.
Hyaluronan (HA) gels (hylans) crosslinked with divinyl sulfone (DVS) are highly biocompatible and can be structurally modified to obtain desired mechanical properties that are attractive for their use as tissue-engineering scaffolds. However, unmodified hylan gels are not good substrates for cell attachment or infiltration, likely as a result of their smooth surface and the highly anionic nature of HA. This study investigated whether the cell-adhering characteristics of hylan gels could be enhanced by irradiation with ultraviolet (UV) light, with or without prior dehydration. The attachment and proliferation of neonatal rat smooth muscle cells atop these gels was compared with that on unmodified (control; C) or dehydrated (D) gels. UV-induced changes to gel structure and chemistry were characterized by confocal and electron microscopy, and fluorphore-assisted carbohydrate electrophoresis (FACE). Cell attachment was sparse on both unmodified (C) and dehydrated (D) gels. Significantly higher levels of cell attachment were observed on the surface of irradiated (UV) and dehydrated-irradiated (DUV) gels, likely because of texturing of the gel surface by UV light. In addition, dehydration of gels before UV irradiation created irregular pore-like structures through which cells appeared to migrate into the interior. FACE assays demonstrated that UV-irradiation alters the chemistry of HA, causing limited breakdown of HA chains and DVS crosslinks within gel and possibly creating new crosslinks that have not yet been identified. Because the hylan gels are altered structurally and chemically, binding of cells to the material is likely to be more permanent than possible by other approaches, such as coating of cell-adhesive matrix factors on the gel surface, described previously. The significance of this work is that we have developed a technique for the modification of DVS-crosslinked HA (hylans) to enhance their performance as a cellular scaffold for tissue-engineering applications. 相似文献