外层型人工视网膜中CMOS感应无线电能接收电路

针对外层型人工视网膜电路对感应无线电能的需求特性,提出了一种适用于外层型人工视网膜的CMOS感应无线电能接收电路。主要实现方法是用CMOS整流器输出作为稳压电路和自偏置电路的电源,而自偏置电路为输出稳压电路提供与电源无关的偏置。采用Cadence 工具和Chartered 0.35 μm CMOS工艺器件模型进行设计,用外层型人工视网膜中的振荡电路阵列作负载,仿真结果表明该外层型人工视网膜中的CMOS感应无线电能接收电路能提供稳定的3.3 V电压输出和大于1 mA的电流负载能力,其版图面积为62 μm×195 μm。     

Large negative hyperpolarizabilities (β) of the protonated Schiff bases of the azulenic retinal analogues

The molecular first hyperpolarizabilities (β) and electronic properties of some azulenic retinal analogues and their derivatives have been investigated theoretically by employing semiempirical approaches. The results indicate that the protonated Schiff bases (PSB) of the 2-substituted azulenic retinal analogues possess extremely large negative β values and very good transparency. These can be attributed to the large difference between the ground state dipole moment and the first excited state dipole moment according to the electronic property analysis. The characteristic blueshifted absorption in polar solvents of the 2-substituted PSB chromophores can be well explained by the negative solvatochromic effects. The largest calculated |μβ| value can reach the magnitude of 10⁻⁴⁴ esu, which is close to the highest reported values of synthesized chromophores.     

一种新颖的视网膜血管形态识别相关网点法

利用人体生物特征的视网膜血管进入个人身份鉴别的研究，提出了一种高层次保安识别应用的相关网点法，包括方法的构思、视网膜血管图像特征交点的提取，网点质心和最远网点的水平方位对准以及图像相关网点匹配的判定。实验结果显示其识别效果良好。     

rHEPO对大鼠急性视网膜光损伤的保护作用及时效性研究

目的探讨重组人促红细胞生成素(r HEPO)对大鼠急性视网膜光损伤的保护作用及时效性.方法选取4周龄雄性SD大鼠48只,随机分成5组:正常对照组、模型对照组、模型治疗1、2、3组,其中正常对照组8只,其余各组均为10只,应用手术显微镜(光照强度为(22 000±1 000)lux)对模型各组造模.模型治疗1、2、3组:分别在光照前4 h、光照后立即、光照后3 d按照5 000 IU/kg腹腔注射r HEPO 1次.模型对照组:光照前后均未给予药物干预.7 d后处死所有大鼠,摘取眼球,应用苏木精-伊红(HE)染色观察视网膜的变化;应用免疫组织化学的方法检测Caspase-3的表达.结果 1)HE染色:正常对照组中大鼠视网膜各层结构完整,层次分明,排列整齐,细胞核形态规整,染色均匀.模型对照组中大鼠视网膜光感受器内、外节排列紊乱,有空泡形成,部分断裂;外核层较正常对照组明显变薄(P0.05),核间隙加大,部分有碎核现象.模型治疗各组大鼠视网膜光感受器内、外节排列紊乱,有小空泡形成;外核层较正常对照组有不同程度变薄(P0.05),模型治疗1、2组好于模型对照组(P0.05),且1组优于2组(P0.05),模型治疗3组与模型对照组比较差异无统计学意义.2)Caspase-3表达:与正常对照组相比,模型各组的Caspase-3表达均有所增强(P0.05);模型治疗1、2、3组表达依次增强,两两比较差异具有统计学意义;模型对照组与模型治疗3组表达最强,二者之间无差异(P0.05).结论 r HEPO对视网膜光损伤具有保护作用,并具有一定的时效性,早期用药效果好,其中光损伤前4 h预用药优于光损伤后立即用药.     

Lipid peroxidation caused by chinoform-ferric chelate in cultured neural retinal cells

Summary Incorporation of chinoform-ferric chelate was demonstrable in cultured neural retinal cells of chick embryos after 1 h of incubation, and the lipid peroxide level in the cells was increased strikingly 1 h thereafter. On the other hand, free ferric ions were scarcely incorporated into the cells, and a significant increase in the lipid peroxide level in the cells was not observed. These data indicate that chinoform is carrier of iron for its passage through cell membranes and that the incorporated iron induces lipid peroxidation which in turn leads to neural cell degeneration.This work was supported in part by a grant from the Ministry of Health and Welfare of Japan     

Effect of temperature on in vitro proliferative activity of human umbilical vein endothelial cells

Human umbilical vein endothelial cells, skin fibroblasts, and retinal pigment epithelial cells are cultivated in medium supplemented with 15 to 20% serum in our laboratory. The effects of various incubation temperatures on the proliferation of these cells was examined. Our study shows that the mitogenic response of the endothelial cells to a change of temperature differed markedly from that of the fibroblasts and epithelial cells. Cultivation of human umbilical vein endothelial at 37°C required seeding densities as high as 1–2×10⁴ cells/cm², and yet resulted in a low growth rate and premature senescence. However, under the same culture conditions, but at 33°C, the proliferative capacity of these endothelial cells was potentiated. The results were striking; at 33°C the cells grew actively and the life span was extended. The number of cumulative population doublings increased fourfold compared with that for the same cells cultivated at 37°C. The inoculum size could be reduced, since at 33°C the endothelial cells were able to replicate at seeding densities as low as 20 cells/cm². The cells serially subcultured at 33°C retained morphological features and specific immunological markers of endothelial cells.     

A survey of 3-dehydroretinal as a visual pigment chromophore in various species of crayfish and other freshwater crustaceans

Summary 3-Dehydroretinal (vitamin A₂ aldehyde) was found in the eyes of three species among 10 species of freshwater crayfish examined. Since dark-adapted eyes contained the 11-cis form of 3-dehydroretinal, this compound must be the chromophore of the visual pigment. 3-Dehydroretinal always coexisted with retinal (vitamin A₁ aldehyde), indicating the presence of a rhodopsin-porphyropsin visual pigment system.     

视神经损伤后视网膜细胞凋亡的研究

目的：探讨凋亡在视神经撞击和挤压的损伤导致视网膜视网膜神经节细胞死亡中的作用。方法：应用活细菌悬液荧光染色法和流式细胞仪ＰＩ染色法检测损伤后多膜神经元凋亡的形态和数据。结果：荧光染色法见视野内有散在细胞出现核染色质凝聚现象（不规则核块）,流式细胞仪ＤＮＡ直方图见正常对照组有直而高的Ｇ０／Ｇ１峰和低平的Ｇ２峰,在Ｇ０／Ｇ１之前有一细胞群体大约占细胞总数的１．６３％,损伤组在Ｇ０／Ｇ１之前有一低小的亚     

视网膜血管形态自识别方法初探

本文就视网膜血管形态生物信息的自识别方法所展开的初步探索，介绍相关研究方法的状况，提出以最大根部网孔表征和提取其形态特征，由网孔拓扑关系建立弹性拓朴匹配模式，实现与网孔方向特征定位无关的形态匹配以及利用多级判据措施提高识别率等方法问题。