A Splicing Mutation in Slc4a5 Results in Retinal Detachment and Retinal Pigment Epithelium Dysfunction

Fluid and solute transporters of the retinal pigment epithelium (RPE) are core components of the outer blood–retinal barrier. Characterizing these transporters and their role in retinal homeostasis may provide insights into ocular function and disease. Here, we describe RPE defects in tvrm77 mice, which exhibit hypopigmented patches in the central retina. Mapping and nucleotide sequencing of tvrm77 mice revealed a disrupted 5’ splice donor sequence in Slc4a5, a sodium bicarbonate cotransporter gene. Slc4a5 expression was reduced 19.7-fold in tvrm77 RPE relative to controls, and alternative splice variants were detected. SLC4A5 was localized to the Golgi apparatus of cultured human RPE cells and in apical and basal membranes. Fundus imaging, optical coherence tomography, microscopy, and electroretinography (ERG) of tvrm77 mice revealed retinal detachment, hypopigmented patches corresponding to neovascular lesions, and retinal folds. Detachment worsened and outer nuclear layer thickness decreased with age. ERG a- and b-wave response amplitudes were initially normal but declined in older mice. The direct current ERG fast oscillation and light peak were reduced in amplitude at all ages, whereas other RPE-associated responses were unaffected. These results link a new Slc4a5 mutation to subretinal fluid accumulation and altered light-evoked RPE electrophysiological responses, suggesting that SLC4A5 functions at the outer blood–retinal barrier.     

ERG and Behavioral CFF in Light-Damaged Albino Rats

The full-field ERG is useful for index rod- or cone-mediated retinal function in rodent models of retinal degeneration. However, the relationship between the ERG response amplitudes and visually guided behavior, such as flicker detection, is not well understood. A comparison of ERG to behavioral responses in a light-damage model of retinal degeneration allows us to better understand the functional implications of electrophysiological changes. Flicker-ERG and behavioral responses to flicker were used to determine critical flicker frequency (CFF) under scotopic and photopic conditions before and up to 90 d after a 10-day period of low-intensity light damage. Dark- and light-adapted ERG flash responses were significantly reduced after light damage. The a-wave was permanently reduced, while the b-wave amplitude recovered over three weeks after light damage. There was a small, but significant dip in scotopic ERG CFF. Photopic behavioral CFF was slightly lower following light damage. The recovery of the b-wave amplitude and flicker sensitivity demonstrates the plasticity of retinal circuits following photopic injury.     

Azide-phenolic resin UV resist (MRL) for microlithography

Poly(4-vinylphenol) sensitized by an aromatic monoazide compound (4-azidochalcone), called MRL (Micro Resist for Longer wavelengths), has been prepared and evaluated as a negative UV resist. The resist is sensitive to radiation in the 300 to 400 nm region. The sensitivity of MRL is comparable to that of a positive quinonediazide photoresist under exposure to unfiltered light from a high pressure Hg lamp. An aqueous base developer removes the unexposed areas of MRL with no evidence of swelling of the exposed areas, indicating its high resolution capability. The main products in the exposure of MRL films are found to be primary and secondary amines. It is concluded that the formation of secondary amines attached to the polymer chain is responsible for the insolubilization of the exposed MRL in the base developer.     

Wavelength sensitivity of AATCC Blue wool lightfastness standards under light radiation

The fading characteristics of the AATCC Blue Wool L2 and L4 lightfastness standards were examined from the standpoint of wavelength sensitivity. Experiments were carried out by exposing a specimen to a narrow monochromatic band isolated from the dispersed polychromatic light emitted by a Xe lamp source. The wavelength sensitivity characteristics of Blue wool L2 and L4 lightfastness were determined on a radiant energy basis. Both Blue Wool Standards displayed peak maxima at 245 and 294 nm. The results indicated that UVA and UVB had a significant fading effect, whereas visible light caused fading to a small extent. Specific wavelengths caused Blue wool to significantly fade, suggesting that the total irradiated UV energy may not be an appropriate index. In addition, their spectral reflectances did not directly explain these characteristics of the standards.     

SIG-1451, a Novel,Non-Steroidal Anti-Inflammatory Compound,Attenuates Light-Induced Photoreceptor Degeneration by Affecting the Inflammatory Process

Age-related macular degeneration is a progressive retinal disease that is associated with factors such as oxidative stress and inflammation. In this study, we evaluated the protective effects of SIG-1451, a non-steroidal anti-inflammatory compound developed for treating atopic dermatitis and known to inhibit Toll-like receptor 4, in light-induced photoreceptor degeneration. SIG-1451 was intraperitoneally injected into rats once per day before exposure to 1000 lx light for 24 h; one day later, optical coherence tomography showed a decrease in retinal thickness, and electroretinogram (ERG) amplitude was also found to have decreased 3 d after light exposure. Moreover, SIG-1451 partially protected against this decrease in retinal thickness and increase in ERG amplitude. One day after light exposure, upregulation of inflammatory response-related genes was observed, and SIG-1451 was found to inhibit this upregulation. Iba-1, a microglial marker, was suppressed in SIG-1451-injected rats. To investigate the molecular mechanism underlying these effects, we used lipopolysaccharide (LPS)-stimulated rat immortalised Müller cells. The upregulation of C-C motif chemokine 2 by LPS stimulation was significantly inhibited by SIG-1451 treatment, and Western blot analysis revealed a decrease in phosphorylated I-κB levels. These results indicate that SIG-1451 indirectly protects photoreceptor cells by attenuating light damage progression, by affecting the inflammatory responses.     

Phototoxicities Caused by Continuous Light Exposure Were Not Induced in Retinal Ganglion Cells Transduced by an Optogenetic Gene

The death of photoreceptor cells is induced by continuous light exposure. However, it is unclear whether light damage was induced in retinal ganglion cells with photosensitivity by transduction of optogenetic genes. In this study, we evaluated the phototoxicities of continuous light exposure on retinal ganglion cells after transduction of the optogenetic gene mVChR1 using an adeno-associated virus vector. Rats were exposed to continuous light for a week, and visually evoked potentials (VEPs) were recorded. The intensities of continuous light (500, 1000, 3000, and 5000 lx) increased substantially after VEP recordings. After the final recording of VEPs, retinal ganglion cells (RGCs) were retrogradely labeled with a fluorescein tracer, FluoroGold, and the number of retinal ganglion cells was counted under a fluorescent microscope. There was no significant reduction in the amplitudes of VEPs and the number of RGCs after exposure to any light intensity. These results indicated that RGCs were photosensitive after the transduction of optogenetic genes and did not induce any phototoxicity by continuous light exposure.     

LED光源对PCB油墨革命性的影响

PCB油墨是指印制电路板(Printed Circuit Board,简称为PCB)所采用的油墨,光引发剂是PCB油墨的重要组分之一,目前常用引发剂最敏感的吸收波长在365nm左右,与高压汞灯(PCB油墨常用的固化光源)发出的最强波长一致;LED光源发出的光波长是395nm,基于光引发剂的吸收光谱与光源的发射光谱相匹配的原则,随着UVLED曝光机的出现,要求对传统PCB油墨中光引发剂的最大吸收波长做出相应的改变,光引发剂的改变将会给PCB油墨带来革命性的影响。     

Control of olfactory-induced behavior in alfalfa seed chalcid (Hymenoptera: Eurytomidae) by celestial light

The behavioral response of female alfalfa seed chalcids is dependent on the polarization of sky light when exposed to olfactory stimuli between 1100 and 1500 hr. Females made no orientation flights to or landings on eight unbaited targets, but when half the targets were baited with the host-plant odor of hexyl acetate, they did make orientation flights to and landed on baited targets. Female preference for baited targets disappeared when natural sky light was plane polarized (at right angles to natural sky light polarization at 1200 hr). When natural sky light was passed through a diffuser filter to completely depolarize the light, females made numerous orientation flights but displayed no preference for baited targets. Any alteration of the natural wavelengths of sky light between 345 and 425 nm with various Kodak Wratten filters that excluded certain wavelengths produced similar results wherein females had no preference for baited or unbaited targets. The hypothesis that chalcid response was controlled by the polarization characteristics of sky light was confirmed when females again preferred baited targets in tests that were conducted 6 hr after sunrise, but they displayed no preference for baited targets when exposed to the mixture of polarized and nonpolarized light present in the sky 1–2 hr after sunrise or 1–2 hr before sunset. The possibility that chalcid response was due to a circadian rhythm was eliminated by exposure of insects to different sequences of light-dark regimes prior to the olfactory test.     

Glial Cell Activation and Oxidative Stress in Retinal Degeneration Induced by β-Alanine Caused Taurine Depletion and Light Exposure

We investigate glial cell activation and oxidative stress induced by taurine deficiency secondary to β-alanine administration and light exposure. Two months old Sprague-Dawley rats were divided into a control group and three experimental groups that were treated with 3% β-alanine in drinking water (taurine depleted) for two months, light exposed or both. Retinal and external thickness were measured in vivo at baseline and pre-processing with Spectral-Domain Optical Coherence Tomography (SD-OCT). Retinal cryostat cross sections were immunodetected with antibodies against various antigens to investigate microglial and macroglial cell reaction, photoreceptor outer segments, synaptic connections and oxidative stress. Taurine depletion caused a decrease in retinal thickness, shortening of photoreceptor outer segments, microglial cell activation, oxidative stress in the outer and inner nuclear layers and the ganglion cell layer and synaptic loss. These events were also observed in light exposed animals, which in addition showed photoreceptor death and macroglial cell reactivity. Light exposure under taurine depletion further increased glial cell reaction and oxidative stress. Finally, the retinal pigment epithelial cells were Fluorogold labeled and whole mounted, and we document that taurine depletion impairs their phagocytic capacity. We conclude that taurine depletion causes cell damage to various retinal layers including retinal pigment epithelial cells, photoreceptors and retinal ganglion cells, and increases the susceptibility of the photoreceptor outer segments to light damage. Thus, beta-alanine supplements should be used with caution.     

Wavelength sensitivity of enhanced photodegradable polyethylenes,ECO, and LDPE/MX

The wavelength sensitivity for decrease in percent elongation at break of ethylene carbon monoxide copolymer (ECO) and a low density polyethylene containing a metal compound prooxidant (LDPE/MX) on exposure to a borosilicate-filtered xenon-arc source was determined using a set of sharp cut-on filters. The spectral region primarily responsible for the degradation at 60°C is 323–328 nm for ECO and 323–338 nm for LDPE/MX. At 77°C, the sensitivity shifts about 10 nm to longer wavelengths. Based on the wavelength sensitivity of these materials to solar simulated radiation and the transmission properties of window glass, these materials can be expected to lose desirable mechanical properties when exposed to window-glass-filtered sunlight. © 1996 John Wiley & Sons, Inc.     

Photodegradation of rigid PVC formulations. II. Spectral sensitivity to light-induced yellowing by polychromatic light

The wavelength sensitivity of a compounded extruded rigid poly(vinyl chloride) formulation to yellowing under exposure to filtered xenon radiation is determined using a cut-on filter technique. Spectral sensitivity of the formulation in the absence and the presence of 2.5 phr of rutile titanium dioxide was examined, and the results were compared to those previously reported for the yellowing of an identical vinyl formulation exposed to monochromatic light. Maximum in the activated spectrum for yellowing under exposure to filtered xenon radiation was found to be in the wavelength region 300–320 nm for both types of samples. The results agreed qualitatively with those previously obtained in the study of the same material exposed to monochromatic light.     

Ultraviolet photodetectors based on ZnO nanoparticles

Ultraviolet (UV) photodetectors based on ZnO nanoparticles (NPs) were fabricated and their optoelectronic properties were examined. The dominant photoluminescence (PL) peak of the ZnO NPs was located at a wavelength of 380 nm under the illumination of 325-nm wavelength light. The direct bandgap transition of the charge carriers at λ = 380 nm contributed to the photocurrent. The ratio of the photocurrent to the dark current (on/off ratio) was as high as 10⁶, which is favorable for photodetectors. The decay time constant in the photoresponse was relatively small, while the rise time constant was relatively large. The reasons for the high on/off ratio and photoresponse characteristics are discussed in this paper.     

Sodium-Iodate Injection Can Replicate Retinal Degenerative Disease Stages in Pigmented Mice and Rats: Non-Invasive Follow-Up Using OCT and ERG

Purpose: The lack of suitable animal models for (dry) age-related macular degeneration (AMD) has hampered therapeutic research into the disease, so far. In this study, pigmented rats and mice were systematically injected with various doses of sodium iodate (SI). After injection, the retinal structure and visual function were non-invasively characterized over time to obtain in-depth data on the suitability of these models for studying experimental therapies for retinal degenerative diseases, such as dry AMD. Methods: SI was injected into the tail vein (i.v.) using a series of doses (0–70 mg/kg) in adolescent C57BL/6J mice and Brown Norway rats. The retinal structure and function were assessed non-invasively at baseline (day 1) and at several time points (1–3, 5, and 10-weeks) post-injection by scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT), and electroretinography (ERG). Results: After the SI injection, retinal degeneration in mice and rats yielded similar results. The lowest dose (10 mg/kg) resulted in non-detectable structural or functional effects. An injection with 20 mg/kg SI did not result in an evident retinal degeneration as judged from the OCT data. In contrast, the ERG responses were temporarily decreased but returned to baseline within two-weeks. Higher doses (30, 40, 50, and 70 mg/kg) resulted in moderate to severe structural RPE and retinal injury and decreased the ERG amplitudes, indicating visual impairment in both mice and rat strains. Conclusions: After the SI injections, we observed dose-dependent structural and functional pathological effects on the retinal pigment epithelium (RPE) and retina in the pigmented mouse and rat strains that were used in this study. Similar effects were observed in both species. In particular, a dose of 30 mg/kg seems to be suitable for future studies on developing experimental therapies. These relatively easily induced non-inherited models may serve as useful tools for evaluating novel therapies for RPE-related retinal degenerations, such as AMD.     

Multivariate optimization of fecal bioindicator inactivation by coupling UV-A and UV-C LEDs

The development of new technologies for water recycling is a priority for arid and semi-arid countries such as those of the Mediterranean basin. The aim of this study was to test the efficiency of UV-A and UV-C light emitting diodes (UV-LEDs) on bacteria inactivation. We used Escherichia coli and Enterococcus faecalis, bioindicators of fecal pollution typically found in urban wastewaters. An experimental design was performed to discriminate weight of factors influencing bacteria inactivation yields and reactivation phenomena. Four parameters were tested on simple bacterial cultures: pH, bacterial density, exposure time and wavelength. It appears that the exposure time and wavelength used have a significant effect on the response. The 280/365 nm or 280/405 nm coupled wavelengths, have the most important bactericidal effect, and we also note the absence of bacterial reactivation after 60 s of exposure to UV.     

Continuous Wave Laser Irradiation of Explosives

Quantitative measurements of the levels of continuous wave (CW) laser light that can be safely applied to bare explosives during contact operations were obtained at 532 nm, 785 nm, and 1550 nm wavelengths. A thermal camera was used to record the temperature of explosive pressed pellets and single crystals while they were irradiated using a measured laser power and laser spot size. A visible light image of the sample surface was obtained before and after the laser irradiation. Laser irradiation thresholds were obtained for the onset of any visible change to the explosive sample and for the onset of any visible chemical reaction. Deflagration to detonation transitions were not observed using any of these CW laser wavelengths on single crystals or pressed pellets in the unconfined geometry tested. Except for the photochemistry of DAAF, TATB and PBX 9502, all reactions appeared to be thermal using a 532 nm wavelength laser. For a 1550 nm wavelength laser, no photochemistry was evident, but the laser power thresholds for thermal damage in some of the materials were significantly lower than for the 532 nm laser wavelength. No reactions were observed in any of the studied explosives using the available 300 mW laser at 785 nm wavelength. Tables of laser irradiance damage and reaction thresholds are presented for pressed pellets of PBX9501, PBX9502, Composition B, HMX, TATB, RDX, DAAF, PETN, and TNT and single crystals of RDX, HMX, and PETN for each of the laser wavelengths.     

Effects of Silica and Titanium Oxide Particles on a Human Neural Stem Cell Line: Morphology,Mitochondrial Activity,and Gene Expression of Differentiation Markers

Several in vivo studies suggest that nanoparticles (smaller than 100 nm) have the ability to reach the brain tissue. Moreover, some nanoparticles can penetrate into the brains of murine fetuses through the placenta by intravenous administration to pregnant mice. However, it is not clear whether the penetrated nanoparticles affect neurogenesis or brain function. To evaluate its effects on neural stem cells, we assayed a human neural stem cell (hNSCs) line exposed in vitro to three types of silica particles (30 nm, 70 nm, and <44 μm) and two types of titanium oxide particles (80 nm and < 44 μm). Our results show that hNSCs aggregated and exhibited abnormal morphology when exposed to the particles at concentrations ≥ 0.1 mg/mL for 7 days. Moreover, all the particles affected the gene expression of Nestin (stem cell marker) and neurofilament heavy polypeptide (NF-H, neuron marker) at 0.1 mg/mL. In contrast, only 30-nm silica particles at 1.0 mg/mL significantly reduced mitochondrial activity. Notably, 30-nm silica particles exhibited acute membrane permeability at concentrations ≥62.5 μg/mL in 24 h. Although these concentrations are higher than the expected concentrations of nanoparticles in the brain from in vivo experiments in a short period, these thresholds may indicate the potential toxicity of accumulated particles for long-term usage or continuous exposure.     

Light wavelengths of LEDs to improve the color discrimination in Ishihara test and Farnsworth Panel D‐15 test for deutans

This study was performed to determine significant light wavelengths to improve color discrimination ability of subjects with deutan. We conducted both the Ishihara test and the Farnsworth Panel D‐15 test for subjects with deutan and normal color vision. Seven different LED lights from 450 to 660 nm and an additional D65 white lamp were utilized to change the lighting conditions, including the wavelength and intensity. The results of the Ishihara test and D‐15 test showed that color identification of deutans was markedly improved with the longer wavelength LEDs regardless of the intensity of the additional D65 lamp. Notably, the error rates of deutans in the Ishihara test were <25% for LED wavelengths of 630 and 660 nm. In the case of subjects with normal color vision, the D65 lamp abolished the errors in the Ishihara test, regardless of the LED wavelength. Addition of the D65 lamp also decreased the number of crossings in the D‐15 test. These results suggested that illumination by LED light with longer wavelengths, such as 630 and 660 nm, may provide deutans with greater red‐green discrimination ability in both the Ishihara test and the Farnsworth Panel D‐15 test. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 424–430, 2017     

Detection of nerve agent stimulants based on photoluminescent porous silicon interferometer

Porous silicon (PSi) exhibiting dual optical properties, both Fabry-Pérot fringe and photolumincence, was developed and used as chemical sensors. PSi samples were prepared by an electrochemical etch of p-type silicon under the illumination of 300-W tungsten lamp during the etch process. The surface of PSi was characterized by cold field-emission scanning electron microscope. PSi samples exhibited a strong visible orange photoluminescence at 610 nm with an excitation wavelength of 460 nm as well as Fabry-Pérot fringe with a tungsten light source. Both reflectivity and photoluminescence were simultaneously measured under the exposure of organophosphate vapors. An increase of optical thickness and quenching photoluminescences under the exposure of various organophosphate vapors were observed.     

Cracking behavior of glazings with different thicknesses by radiant exposure

Fourteen experiments on cracking behavior of glazings with thicknesses of 3, 6, 8, and 10 mm by radiant exposure were carried out with a new experimental apparatus. The radiant power was controlled proportional to time square to simulate a time‐squared growth fire. An infrared thermal imaging camera was employed to monitor the temperature field of the unexposed glazing surface. Other important parameters including incident heat flux, local gas temperature, exposed surface temperature, and time of the first cracking were obtained. The relationship between the cracking behavior and glazing thickness was analyzed based on the experimental results. The results show that the protected edge temperature of glazing has a considerable rise when the first cracking occurred, which should be included in further modeling. It was also shown that thicker glazings have smaller surface temperature during the heating process and induce longer time to first crack. However, the critical temperature difference approximately remains constant for all glazings studied. Copyright © 2011 John Wiley & Sons, Ltd.     

Influence of Green,Red and Blue Light Emitting Diodes on Multiprotein Complex Proteins and Photosynthetic Activity under Different Light Intensities in Lettuce Leaves (Lactuca sativa L.)

The objective of this study was to investigate the response of light emitting diodes (LEDs) at different light intensities (70 and 80 for green LEDs, 88 and 238 for red LEDs and 80 and 238 μmol m⁻² s⁻¹ for blue LEDs) at three wavelengths in lettuce leaves. Lettuce leaves were exposed to (522 nm), red (639 nm) and blue (470 nm) LEDs of different light intensities. Thylakoid multiprotein complex proteins and photosynthetic metabolism were then investigated. Biomass and photosynthetic parameters increased with an increasing light intensity under blue LED illumination and decreased when illuminated with red and green LEDs with decreased light intensity. The expression of multiprotein complex proteins including PSII-core dimer and PSII-core monomer using blue LEDs illumination was higher at higher light intensity (238 μmol m⁻² s⁻¹) and was lowered with decreased light intensity (70–80 μmol m⁻² s⁻¹). The responses of chloroplast sub-compartment proteins, including those active in stomatal opening and closing, and leaf physiological responses at different light intensities, indicated induced growth enhancement upon illumination with blue LEDs. High intensity blue LEDs promote plant growth by controlling the integrity of chloroplast proteins that optimize photosynthetic performance in the natural environment.