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1.
We have fabricated a molecular organic light-emitting device comprising indium–tin oxide/a molecular organic layer/aluminum in which the organic layer is a green fluorescent protein. The device exhibits peak external quantum and power efficiencies of 8?±?0.2% and 13?±?0.7?lm?W???1 at a current of J?=?1.5?A?m?2, respectively. In addition, the turn-on voltage is 2.5?V for 1?cd?m?2 and the maximum luminance achieved is 1275?cd?m?2. This good performance can be explained by the presence of singlet-excited states, leading to a high internal efficiency.  相似文献   
2.
刘少林  张均田 《心理学报》1998,31(2):224-229
对海马突触传递长时程增强效应的研究已取得许多重要进展,其中发现很多蛋白激酶的参与,近年来由于转基因和基因打靶等分子生物学实验手术的应用,PKC,CaMKⅡ和PKA等多种蛋白激酶的同功酶或其不同亚单位在LTP中的作用已在相应的变异小鼠上得到直接证实,文章概述了这些目前被认为参与了海马突触传递长时程增强过程的蛋白激酶及其作用。  相似文献   
3.
We studied the role of free radicals on brain oxidative damage in rats after acute immobilization stress (restraint) and mild emotional stress (handling). To investigate brain oxidative damage, CuZn and Mn dependent superoxide dismutase (CuZn SOD, Mn SOD) activities, lipid peroxidation (TBARs), Na + K + ATPase activity, protein carbonyl (PrC), and reduced and oxidized glutathione (GSH, GSSG) levels were measured in the cerebral cortex (CTX), hippocampus (HIP), and striatum (ST) of the animals after the two different stress stimuli. Because stress produces abnormalities in the hypothalamic-pituitary-adrenal axis, the intensity of the two stress conditions were measured by plasmatic corticosteroid (COR) levels: particularly, COR levels doubled in handled rats and increased 15-fold in restrained animals. The SOD activities increased in CTX and decreased in HIP of the handled rats, while in ST a significant decrease in handled animals but an increase in restrained animals occurred. TBARs, GSH, and GSSG levels remained unchanged, while an index of glutathione redox decreased significantly in ST of handled animals and in CTX of restrained ones. Na + K + ATPase activity increased significantly in the HIP and ST of both groups of stressed rats. The stress induced a remarkable increase in PrC levels in all studied cerebral areas. These findings provide evidence to support the idea that stress produces oxidants but that the oxidative damage in stress differs in cerebral areas and could contribute to the degenerative mechanism of aging.  相似文献   
4.
Charles F. Smith 《Zygon》2000,35(1):181-187
DNA is an important agent not only in chemistry and biology but also in technology and modern culture. A number of books approach the double helix from different angles. These perspectives include (1) the science of DNA and genetics; (2) genetic engineering; (3) the ethics of manipulating genetic material; and (4) DNA in culture and religion. Various views of DNAprovide insights into human nature beyond its molecular composition.  相似文献   
5.
Entorhinal neurons receive extensive intracortical projections, and form the primary input to the hippocampus via the perforant pathway. The glutamatergic cells of origin for the perforant pathway are distinguished by their expression of reelin, a glycoprotein involved in learning and synaptic plasticity. The functional significance of reelin signaling within the entorhinal cortex, however, remains unexplored. To determine whether interrupting entorhinal reelin signaling might have consequences for learning and memory, we administered recombinant receptor-associated protein (RAP) into the lateral entorhinal cortex (LEC) of young Long-Evans rats. RAP prevents reelin from binding to its receptors, and we verified the knockdown of reelin signaling by quantifying the phosphorylation state of reelin’s intracellular signaling target, disabled-1 (DAB1). Effective knockdown of reelin signaling was associated with impaired performance in the hippocampus-dependent version of the water maze. Moreover, inhibition of reelin signaling induced a localized loss of synaptic marker expression in the LEC. These observations support a role for entorhinal reelin signaling in spatial learning, and suggest that an intact reelin signaling pathway is essential for synaptic integrity in the adult entorhinal cortex.  相似文献   
6.
植物药复方是中医辨证施治的主要手段。药物是通过蛋白质起作用的。蛋白质复杂多样的功能与其时空的复杂演变密切相关,复方如何对蛋白质时空产生影响、如何对其结构与功能发生作用以及两者之间相互作用、相互影响的深入研究可能发现新的生命现象,为阐明疾病发病机理以及植物药的创新研制奠定理论基础和提供技术支持。  相似文献   
7.
双酚A (bisphenol, BPA)是一种广泛应用于塑料制品的环境内分泌干扰物, 具有弱雌激素和抗雄激素活性, 与雌激素受体有一定的亲和力。本实验探讨长期BPA暴露对成年小鼠恐惧记忆的影响及其神经机制。将9周龄雄性小鼠暴露于BPA (0.4、4、40 mg/kg/d) 90 d, 建立小鼠亚慢性BPA暴露模型后, 进行场景性条件恐惧训练, 然后分别在电击后1 hr及24 hr检测小鼠的僵立时间, 同时在电击前、电击后1 hr及24 hr检测海马相关蛋白表达变化。结果表明, BPA (4、40 mg/kg/d)暴露延长小鼠场景性条件恐惧训练后1 hr及24 hr的僵立时间。Western blot蛋白检测结果显示, 行为训练前, BPA降低了小鼠NMDA受体NR1亚基表达水平, 上调组蛋白去乙酰化酶2表达。行为训练后1 hr及24 hr, BPA促进海马NMDA受体亚基NR1和组蛋白H3乙酰化表达, 抑制组蛋白去乙酰化酶2表达, 同时促进ERK1/2磷酸化水平。以上结果表明, 长期BPA暴露提高成年小鼠恐惧记忆获得的同时延长恐惧记忆的保持; 该作用可能通过激活海马的ERK1/2通路而改变核内组蛋白乙酰化和NMDA受体水平进行。  相似文献   
8.
重组人类活性蛋白C(rhAPC)为治疗重症脓毒症的药物,目前有证据表明rhAPC的市场策略有可能已经影响到专业机构诊治指南的制定与执行;rhAPC的临床疗效亦未能被大型临床试验继续证实,因此目前rhAPC的临床应用以及疗效评价要慎重进行。同时,有必要深入反思药品生产商与专业组织的利益关系,并制订对策以加强监管。  相似文献   
9.
高危型别人乳头瘤病毒(HPV)感染在宫颈癌发生发展中具有重要作用。由于HPV L1蛋白结构特征及其精确的抗原特性,在粘附宿主细胞、识别病毒受体、协助病毒DNA的入胞转运中均发挥重要作用。检测患者宫颈损伤组织中L1蛋白的表达将有助于对患者是否具有传染性进行评估。本文将深刻思考HPV L1功能及其在感染机体并引发癌变的机制,以期更好的解读宫颈癌发病原理并最终应用于,强床治疗。  相似文献   
10.
总结肿瘤标记物在大肠癌临床诊治中的应用进展。对有关大肠癌临床诊治中肿瘤标记物的文献进行综述,重点讨论血清、基因和急性期蛋白三类标记肿瘤物对大肠癌临床诊治方面的价值和潜力。结果是恰当选择肿瘤标记物有助于大肠癌临床诊治。目前,基因和急性期蛋白为大肠癌肿瘤标记物探索的新方向,有望成为提高大肠癌诊治效率的新检查方法。三类肿瘤标记物对大肠癌诊治有临床意义,联合检测可提高大肠癌诊治的准确性和有效性。  相似文献   
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