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Optogenetics methods are rapidly being developed as therapeutic tools for treating neurological diseases, in particular, retinal degenerative diseases. A critical component of the development is testing the safety of the light stimulation used to activate the optogenetic proteins. While the stimulation needs to be sufficient to produce neural responses in the targeted retinal cell class, it also needs to be below photochemical and photothermal limits known to cause ocular damage. The maximal permissible exposure is determined by a variety of factors, including wavelength, exposure duration, visual angle, pupil size, pulse width, pulse pattern, and repetition frequency. In this paper, we develop utilities to systematically and efficiently assess the contributions of these parameters in relation to the limits, following directly from the 2014 American National Standards Institute (ANSI). We also provide an array of stimulus protocols that fall within the bounds of both safety and effectiveness. Additional verification of safety is provided with a case study in rats using one of these protocols. [ABSTRACT FROM AUTHOR]

Abstract Corrosion behaviors of the friction welded dissimilar aluminum alloys were investigated to understand how galvanic effect plays a role in altering corrosion properties of the dissimilar weld. From the fact that the weld had the similar OCP value to that of AA2017, it can be inferred that the corrosion characteristics of the weld is under the control of the AA2017 part in the weld and as a result, only the AA2017 part in the weld had experienced severe corrosion, leaving AA6063 under cathodic protection. Intense corrosion occurring near the interface implies that the area near the interface is placed under the effect of galvanic corrosion and there was the effective distance where the galvanic effect exerts an impact due to the increase in the resistance of the electrolyte with the distance from the interface. The disappearance of Warburg diffusion plot in Nyquist plots for the weld seemed to be the breakdown of the passivation layer related to the formation of the micro-galvanic cell, which in turn presented the shrinkage in the capacitance response, indicating that charge reactions in the form of corrosion occurred. Graphical Abstract Unlabelled Image Highlights • Corrosion properties of friction welded dissimilar aluminum alloys seem to be governed by the anode part in the weld. • Intense corrosion near the interface has the limited region due to insufficient ionic transport. • Self-formation of a micro-galvanic cell is a main reason for the inferior corrosion performance. [ABSTRACT FROM AUTHOR]

Retinal pigment epithelium-specific protein 65 kDa (RPE65) is a protein responsible for isomerization of all-trans-retinaldehyde to its photoactive 11-cis-retinaldehyde and is essential for the visual cycle. RPE65 mutations can cause severe, early onset retinal diseases such as Leber congenital amaurosis (LCA). A naturally occurring rodent model of LCA with a recessive nonsense Rpe65 mutation, the rd12 mouse, displays a profoundly diminished rod electroretinogram (ERG), an absence of 11-cis-retinaldehyde and rhodopsin, an overaccumulation of retinyl esters in retinal pigmented epithelial (RPE) cells, and photoreceptor degeneration. rd12 mice were injected subretinally at postnatal day 14 with rAAV5-CBA-hRPE65 vector. RPE65 expression was found over large areas of RPE soon after treatment. This led to improved rhodopsin levels with ERG signals restored to near normal. Retinyl ester levels were maintained at near normal, and fundus and retinal morphology remained normal. All parameters of restored retinal health remained stable for at least 7 months. The Morris water maze behavioral test was modified to test rod function under very dim light; rd12 mice treated in one eye performed similar to normally sighted C57BL/6J mice, while untreated rd12 mice performed very poorly, demonstrating that gene therapy can restore normal vision-dependent behavior in a congenitally blind animal.Molecular Therapy (2006) 13, 565–572; doi: 10.1016/j.ymthe.2005.09.001 [ABSTRACT FROM AUTHOR]