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91.
NADPH diaphorase histochemistry is commonly used to identify cells containing nitric oxide synthase (NOS), the enzyme catalyzing the production of nitric oxide from L-arginine. NADPH diaphorase activity and NOS immunostaining was demonstrated in different cells of the vertebrate retina; photoreceptors, horizontal cells, amacrine cells, ganglion cells, and Müller cells. However, the physiological role of nitric oxide (NO) in the retina has yet to be elucidated. In this study, we tested the assumption that NADPH diaphorase activity in the retinas of rabbits and rats depended on the state of visual adaptation. In the rabbit, light adaptation enhanced NADPH diaphorase activity in amacrine cells and practically eliminated it in horizontal cells. Dark adaptation induced the opposite effects; the NADPH diaphorase activity was reduced in amacrine cells and enhanced in horizontal cells. Retinas from eyes that were injected intravitreally with L-glutamate exhibited a pattern of NADPH diaphorase activity that was similar to that seen in dark-adapted retinas. In rats, the NADPH diaphorase activity of amacrine and horizontal cells exhibited adaptation dependency similar to that of the rabbit retina. But, the most pronounced effect of dark adaptation in the rat's retina was an enhancement of NADPH diaphorase activity in Müller cells, especially of the endfoot region. Assuming that NADPH diaphorase activity is a marker for NOS, these findings suggest that NO production in the mammalian retina is modulated by the level of ambient illumination and support the notion that NO plays a physiological role in the retina. 相似文献
92.
C_MPS的设计与实现 总被引:1,自引:0,他引:1
元程序设计系统是进行元程序设计的有效工具。C_MPS(CMetaProgra-mming System)是我们在PC机上开发的C语言的元程序设计系统,本文介绍了该系统的设计思想和实现技术。 相似文献
93.
Void formation and growth in a class of compressible solids 总被引:1,自引:0,他引:1
A new class of compressible elastic solids, which includes the Blatz-Ko material as a special case, is proposed. A closed-form solution is constructed and studied for a bifurcation problem modeling void formation in this class of compressible elastic solids. The relation between the void-formation condition and the material parameters is obtained analytically. An energy comparison of the void-formation deformation and the homogeneous expansion deformation is carried out. 相似文献
94.
Cleavage fracture in an Al-Li alloy 8090 总被引:1,自引:0,他引:1
Jiang Daming Wang Yinong Hong Bande Lei Tingquan Sun Fenglian 《Journal of Materials Science Letters》1996,15(18):1597-1600
95.
使用1246与3762复合催化剂加氢裂化处理含焦化蜡油(50%以上)混合原料油时,催化剂不仅具有高脱氮能力、高转化率,同时,还具有好的加氢活性稳定性,为焦化蜡油的合理加工找到一条新路,并有显著的经济效益 。 相似文献
96.
97.
基于NURBS的PDE曲面构造法研究及应用 总被引:2,自引:0,他引:2
由非均匀有理B样条曲线曲面给定边界条件,用偏微分方程来构造曲面,以参数“a”控制其整体形状,本文分析其思路原理及过程,并列举了在CAD上的应用,最后分析了优缺点。 相似文献
98.
应用Gleeble-1500热模拟实验机进行等温压缩试验,研究了变形工艺参数对34CrMoV结构钢动态再结晶行为的影响.结果表明,其流变应力随变形温度升高而降低,随应变速率提高而增大;随着应变速率的降低,应变量的增加和变形温度的升高,动态再结晶速度加快且奥氏体晶粒得到细化. 相似文献
99.
强化会计内部控制促进高校科学管理 总被引:1,自引:0,他引:1
建立和强化完善的会计内部控制体系,对于高校优化资源,促进科学管理有着重要意义.针对当前高校会计内部控制的不足,提出了若干解决对策. 相似文献
100.
Gradient Boundary Detection for Time Series Snapshot Construction in Sensor Networks 总被引:1,自引:0,他引:1
Jie Lian Lei Chen Naik K. Yunhao Liu Agnew G.B. 《Parallel and Distributed Systems, IEEE Transactions on》2007,18(10):1462-1475
In many applications of sensor networks, the sink needs to keep track of the history of sensed data of a monitored region for scientific analysis or supporting historical queries. We call these historical data a time series of value distributions or snapshots. Obviously, to build the time series snapshots by requiring all of the sensors to transmit their data to the sink periodically is not energy efficient. In this paper, we introduce the idea of gradient boundary and propose the gradient boundary detection (GBD) algorithm to construct these time series snapshots of a monitored region. In GBD, a monitored region is partitioned into a set of subregions and all sensed data in one subregion are within a predefined value range, namely, the gradient interval. Sensors located on the boundaries of the subregions are required to transmit the data to the sink and, then, the sink recovers all subregions to construct snapshots of the monitored area. In this process, only the boundary sensors transmit their data and, therefore, energy consumption is greatly reduced. The simulation results show that GBD is able to build snapshots with a comparable accuracy and has up to 40 percent energy savings compared with the existing approaches for large gradient intervals. 相似文献