Outer Layer Thickness Research Articles

Influence of Nitrogen Content on the Microstructure Evolution and Oxidation Resistance toward Ambient Air of CrAlSiN Coatings Deposited by FCVAD Technique.

In this study, CrAlSiN coatings with nitrogen contents ranging from approximately 42 to 54 at. % were deposited and subsequently exposed to temperatures of 700 or 900 °C for 2 h in ambient air to investigate the impact of nitrogen content on the microstructure evolution and high-temperature oxidation resistance. It was found that the CrAlSiN coating with nitrogen content of 42-45 at. % exhibited an amorphous/nanocrystalline hybrid structure, comprising pure metallic Cr and (Al,Cr)N phases within the matrix, as determined by the TEM, XRD, and XPS analysis. In contrast, as the nitrogen content exceeded 52 at. %, the coatings transformed to a dominantly columnar structure featuring solely Cr(Al)N phase. The CrAlSiN coating with a nitrogen content of ∼52 at. % retained amorphous fraction of around 20% but demonstrated superior oxidation resistance with the lowest parabolic rate constant of 1.1 × 10-14 cm2/s at 900 °C compared to other coatings. This enhanced performance was primarily attributed to the high stability of Cr(Al)N phase and formation of a fine-columnar/amorphous microstructure devoid of metallic Cr, resulting in a significantly thin (∼60 nm) yet dense Al2O3-rich monolayer atop the coating surface during the oxidation. Conversely, substoichiometric CrAlSiN coatings with N content ≤45 at. % would form a thick Cr2O3 outer layer over an underlying Al2O3 layer. Additionally, elemental segregation of Cr, Si, and Al was observed in all CrAlSiN coatings after exposure to 900 °C for 2 h, which was induced by the spinodal decomposition of the ternary nitride phases.

The Influence of the Parameters of the Skew Rolling Process for Bimetallic Elements on the Mechanical Properties and Structure of Materials.

This paper presents selected results of theoretical and experimental research into the manufacture of axisymmetric bimetallic components using three-tool skew rolling technology. In the tests, it was assumed that the outer layer would be a material intended for heat treatment. However, low-carbon steel was used for the core. Experimental investigations were carried out in an innovative CNC skew rolling mill. Tests were carried out at different technological parameters of the process. In addition, the geometric parameters of the billet and the way it was heated were analyzed in relation to the quality of the resulting weld between the two materials. The quality of the weld was assessed based on metallographic observation and on strength tests (shear method). On the other hand, theoretical studies were based on numerical modeling (FEM). The numerical analysis made it possible to determine the distribution of temperature, deformation and stress in the rolling bimetallic component. The results obtained indicated that it is possible to produce bimetallic materials from the proposed steel grades. In addition, a significant effect of the method of heating the billet in the chamber furnace on the microstructure in the joining zone and the shear strength was found. There was an increase in Rc strength of about 35% when using oxidation protection. The results indicated better strength when the billet is rolling with a smaller outer layer thickness (about 50 MPa). This was confirmed by the results obtained from the FEM analysis, which indicated higher values of plastic strain and the occurrence of higher compressive stresses in the near-surface zones of the rolled bimetallic forging, both of which facilitate the welding process. From the temperature distribution (in the range of (600-1200) °C) obtained during the rolling of the bimetal forging, it can be seen that contact with cold tools does not affect the temperature in the welding zone.

Controlling η phase distribution and its effects on carburized graded cemented carbides via extrusion additive manufacturing

Functionally Gradient cemented carbides (FGCCs) are promising substrates for polycrystalline diamond composite (PDC). Carburization is the mainstream method for preparing FGCCs, but limited carburizing depth often leads to excessive retention of brittle low-carbon phase (η phase) in the core. This study used Powder Extrusion 3D Printing (PEP) to create dual-layered cemented carbide parts with varying thicknesses of low-carbon outer layers. After pre-sintering and carburization, three new FGCCs were produced. Results showed the η phase was confined to the interface region before carburization. With 3.84 mm carbon-depleted layer, the maximum η phase thickness was 1/10 compared to homogeneous FGCCs, with Co gradient of about 4.5 wt%. The two FGCCs with thinner low-carbon layers had smaller Co gradient with no detected η phase. Additionally, the novel FGCCs displayed enhanced fracture toughness in the core. This study achieved controlled η phase distribution, offering new insights for fabricating high-toughness carburized FGCCs without the η phase.

The study on the magnetic interaction between the duel magnetic layers and the FINEMET ribbon

Due to the sensitive magnetic field response of the GMI effect, the peak field in magneto impedance curves obtained from the composite magnetic ribbons shows great dependence on the magnetic interaction, which has gained intensive attention in the study of the diversity and the mechanism of magnetic interaction. In this work, FINEMET/Fe20Ni80/SiO2/Fe20Ni80 composite ribbons with a fixed thickness of outer Fe20Ni80 layer (200 nm) and variable thickness ratio of the inner Fe20Ni80 and SiO2 layers, ranging from the 1:4 to 4:1 were prepared. Then the GMI response was utilized to investigate the influence of the exchange couple and the dipole interaction to magnetic properties of the base ribbon. The experimental results indicated that additional SiO2 layer can successfully induce slight magnetic differences of the two Fe20Ni80 layers, which results in the emergence of four-peak GMI profiles. Besides, the frequency-dependent nature of the peaks was explored, revealing that both dipole interaction and exchange couple influence the magnetic properties, contributing to the occurrence of four-peak GMI curves. Thus, the insights presented in this work are thought to be valuable for understanding the mechanisms of multilayer composite ribbons in future sensing applications.

FIB-SEM Study of Archaeological Human Petrous Bones: 3D Structures and Diagenesis

The petrous bone generally preserves ancient DNA better than other fossil bones. One reason for this is that the inner layer of the petrous bone of pigs and humans contains about three times as many osteocytes as other bones, and hence more DNA. A FIB-SEM study of modern pig petrous bones showed that the 3D structure of the thin inner layer is typical of woven bone that forms in the fetus, whereas the thicker outer layer has a lamellar structure. The lamellar structure is common in mammalian bones. Here we study human petrous bones that are about 2500 years old, obtained from three Phoenician sites in Sicily, Italy. A detailed FIB-SEM study of two of these bones, one well preserved and the other poorly preserved, shows that the 3D bone type structure of the human petrous inner layer is woven bone, and the outer layer is lamellar bone. These are the same bone type structures found in pig petrous bones. Furthermore, by comparing nine differently preserved petrous bones from the same archaeological region and age, we show that their collagen contents vary widely, implying that organic material can be significantly altered during diagenesis. The mineral crystals are better preserved and hence less crystalline in the inner layers compared to the outer layers. We therefore infer that the best-preserved DNA in fossil petrous bones should be found in the thin inner layers immediately adjacent to the otic cavity where much more DNA is initially present and the mineral phase tends to be better preserved.

Thickened photoreceptor outer segment layer in children with hyperopic anisometropic amblyopia.

To quantitatively investigate the reflectivity and structure of the outer retinal layers in children with hyperopic anisometropic amblyopia by using swept-source optical coherence tomography (SS-OCT). Seventy-eight patients with amblyopia and 64 age-matched children with normal vision were included in this study. All participants underwent SS-OCT and detailed ophthalmic examinations. Longitudinal reflectance profile measurements were measured using Image J. The reflectivity of outer retinal layers was measured at the three selected positions: subfovea, 1 mm nasal to the fovea, and 1 mm temporal to the fovea. The reflectivity ratios were calculated by outer retinal layers divided by the nuclear layer (ONL) for normalization. Photoreceptor outer segment layer thickness was also measured. The results were compared between the amblyopia and normal controls. The possible effects of age, sex, and axial length on results were adjusted by generalized estimating equations. Photoreceptor outer segment layer thickness was significantly greater in amblyopic eyes than in normal control eyes at all three regions (18.41 ± 1.83 vs. 16.84 ± 1.39, P < 0.001 at the fovea; 14.78 ± 1.34 vs. 14.19 ± 1.40, P = 0.030 at 1 mm nasal to the foveal; 14.92 ± 1.48 vs. 14.41 ± 1.32, P = 0.049 at 1 mm temporal to the fovea). The reflectivity ratio of outer segment/ONL was higher only at 1 mm nasal to the fovea (2.94 ± 0.61 vs. 2.70 ± 0.42, P = 0.02). Subfoveal OS thickness was positively correlated with choroidal thickness (r = 0.248, P = 0.018) but was not correlated with spherical equivalent, age, axial length, or logMAR visual acuity. Quantitative measurement of SS-OCT images revealed greater photoreceptor outer segments in both eyes of children with amblyopia than in normal control eyes. A thicker OS thickness is somehow related to amblyopia, and this may be a new useful diagnostic parameter for amblyopia.

Integrating Machine Learning and Traditional Survival Analysis to Identify Key Predictors of Foveal Involvement in Geographic Atrophy.

The purpose of this study was to investigate the incidence of foveal involvement in geographic atrophy (GA) secondary to age-related macular degeneration (AMD), using machine learning to assess the importance of risk factors. Retrospective, longitudinal cohort study. Patients diagnosed with foveal-sparing GA, having GA size ≥ 0.049mm² and follow-up ≥ 6months, were included. Baseline GA area, distance from the fovea, and perilesional patterns were measured using fundus autofluorescence. Optical coherence tomography assessed foveal involvement, structural biomarkers, and outer retinal layers thickness. Onset of foveal involvement was recorded. Foveal survival rates were estimated using Kaplan-Meier curves. Hazard ratios (HRs) were assessed with mixed model Cox regression. Variable Importance (VIMP) was ranked with Random Survival Forests (RSF), with higher scores indicating greater predictive significance. One hundred sixty-seven eyes (115 patients, average age = 75.8 ± 9.47years) with mean follow-up of 50 ± 29months, were included in this study. Median foveal survival time was 45months (95% confidence interval [CI] = 38-55). Incidences of foveal involvement were 26% at 24months and 67% at 60months. Risk factors were GA proximity to the fovea (HR = 0.97 per 10-µm increase, 95% CI = 0.96-0.98), worse baseline visual acuity (HR = 1.37 per 0.1 LogMAR increase, 95% CI = 1.21-1.53), and thinner outer nuclear layer (HR = 0.59 per 10-µm increase, 95% CI = 0.46-0.74). RSF analysis confirmed these as main predictors (VIMP = 16.7, P = 0.002; VIMP = 6.2, P = 0.003; and VIMP = 3.4, P = 0.01). Lesser baseline GA area (HR = 1.09 per 1-mm2 increase, 95% CI = 1.01-1.16) and presence of a double layer sign (HR = 0.42, 95% CI = 0.20-0.88) were protective but less influential. This study identifies anatomic and functional factors impacting the risk of foveal involvement in GA. These findings may help identify at-risk patients, enabling tailored preventive strategies.

Analysis of boundary layer characteristics in supergravitational turbulent thermal convection

We investigate the boundary layer characteristics within annular centrifugal Rayleigh–Bénard convection (ACRBC) considering a Rayleigh number Ra∈[108,1011], a Prandtl number Pr = 10.7, and an inverse Rossby number Ro−1=16. Our study is based on the temperature and velocity data obtained from direct numerical simulations. Different from the flow over a flat plate, the ACRBC system bifurcates into three regions: the plume-impacting regions, plume-ejecting regions, and plume-sweeping regions, and all three regions are moving with the zonal flow. Our focus is primarily on the temperature dynamics within the plume-sweeping region, where the wind of large-scale circulation shears the boundary. We determine the transient thermal boundary layer thickness over time using the slope method, relying on the temperature curve's orientation relative to the wall. Notably, the probability density function distribution of the thermal boundary layer thickness is reminiscent of traditional RBC systems, albeit with a more extended exponential tail. Employing a dynamic frame based on time resampling, we discern that the temperature boundary layer traits align with the Prandtl–Blasius boundary layer theory. In conclusion, we show that the exponential decay index for the thermal boundary layer thickness harmonizes with the system's heat transfer scaling law. It is found that the ratio between the inner and outer boundary layer thickness remains stable, providing theoretical guidance for the design and control of the internal flow field of high-speed rotating machinery.

Experiments and DFT calculations on the effects of interstitial hydrogen on Ti corrosion products in high temperature water

The effects of the interstitial hydrogen on the characteristics of corrosion product of pure Ti in high temperature water was studied by a double exposure corrosion experiment and DFT calculations. A double-layer corrosion product was found in both internally hydrogen charged specimen and internally vacuumed specimen. The main difference in corrosion product was the thickness of outer layer. The adsorption energies of Fe, Ti and O atoms on three surfaces (Ti, TiO2 and FeTiO3) with and without an interstitial hydrogen were considered in the DFT calculation. The correlations between the experimental results and DFT calculations were also discussed.

Microstructural development and oxidation resistance of MSi2-type multicomponent silicide coatings on Nb alloys by spark plasma sintering

MSi2-type multicomponent silicide coatings were prepared on Nb alloys by spark plasma sintering using mixed powders of Mo, Ta, W, Zr, Ti and Si. The coatings were composed of thick outer layers and thin inner layers (interdiffusion zone). A two-phase structure consisting of C11b (Mo,Ta,W,Ti)Si2 and C40 (Ti,Ta,Zr)Si2 was observed in the outer layers of all the coatings sintered for holding times ranging from 15 s to 5 min, but the distribution of these elements in each phase gradually became uniform with increasing holding time. The coatings demonstrated excellent protection during oxidation at 1300 °C for 100 h, and a continuous dense oxide scale mainly composed of ZrSiO4 and SiO2 was generated. The alternation of heating and cooling during oxidation caused cracks to appear at the interface between the outer layer and inner layer due to a mismatch of thermal expansion coefficients. However, crack extension was observed only along the inner layer toward the interior due to the multicomponent structure of the outer layer of the coating. The microstructural development and oxidation behavior of the coatings were discussed.

Guinea fowl eggshell structural analysis at different scales reveals how organic matrix induces microstructural shifts that enhance its mechanical properties

Guinea fowl eggshells have an unusual structural arrangement that is different from that of most birds, consisting of two distinct layers with different microstructures. This bilayered organization, and distinct microstructural characteristics, provides it with exceptional mechanical properties. The inner layer, constituting about one third of the eggshell thickness, contains columnar calcite crystal units arranged vertically as in most bird shells. However, the thicker outer layer has a more complex microstructural arrangement formed by a switch to smaller calcite domains with diffuse/interlocking boundaries, partly resembling the interfaces seen in mollusk shell nacre. The switching process that leads to this remarkable second-layer microstructure is unknown. Our results indicate that the microstructural switching is triggered by changes in the inter- and intracrystalline organic matrix. During production of the outer microcrystalline layer in the later stages of eggshell formation, the interactions of organic matter with mineral induce an accumulation of defects that increase crystal mosaicity, instill anisotropic lattice distortions in the calcite structure, interrupt epitaxial growth, reduce crystallite size, and induce nucleation events which increase crystal misorientation. These structural changes, together with the transition between the layers and each layer having different microstructures, enhance the overall mechanical strength of the Guinea fowl eggshell. Additionally, our findings provide new insights into how biogenic calcite growth may be regulated to impart unique functional properties. Statement of significanceAvian eggshells are mineralized to protect the embryo and to provide calcium for embryonic chick skeletal development. Their thickness, structure and mechanical properties have evolved to resist external forces throughout brooding, yet ultimately allow them to crack open during chick hatching. One particular eggshell, that of the Guinea fowl, has structural features very different from other galliform birds – it is bilayered, with an inner columnar mineral structure (like in most birds), but it also has an outer layer with a complex microstructure which contributes to its superior mechanical properties. This work provides novel and new fundamental information about the processes and mechanisms that control and change crystal growth during the switch to microcrystalline domains when the second outer layer forms.

Axisymmetric vibration and stability of dielectric-elastic tubular bilayer system

Modern transducers and actuators may have functional layers with multi-field coupling and some elastic layers. This paper considers a tubular bilayer system consisting of a thin dielectric tube coated with a thick elastic layer. We study the nonlinear electromechanical response and the linear axisymmetric vibration of the system subject to different applied voltages and inner/outer pressures within the framework of the general nonlinear theory of electro-elasticity, the related linear incremental theory, and by considering the continuity conditions at the interface. We investigate instability behaviour using the same basic formulae. The state-space method provides efficient and accurate free vibration analysis, considering the dynamic response at the lowest frequencies, so we can neglect the viscous and damping effects, which is well suited to this problem. New results indicate that the bilayer system improves its frequency capability and stability compared to the monolayer dielectric tube. The thick outer elastic layer stiffens the bilayer system against axisymmetric bifurcation, bulging and necking instabilities. It also performs better in front of axisymmetric instability, increasing the system’s capability to receive or produce higher voltages, especially for long waves.This work thoroughly explains bilayer functional systems’ behaviour when exposed to extreme environments such as high voltage or pressure.

Interfacial engineering of core–shell structured FeCoNi@SnO2 magnetic composites for tunable radar-infrared compatible stealth

Radar-Infrared (IR) compatible camouflage is challenging as the spectral requirements for two bands differ or even collide with each other. Hence, the development of compatible stealth materials is urgently needed. This study employed a simple method to synthesize core–shell FeCoNi@SnO2 composite materials (MCCMs) with different alloy and SnO2 thicknesses. The unique interfacial engineering, the synergistic effect between multiple components, and the low IR emissivity of SnO2 allow this material to excel in radar-IR compatible stealth. Notably, the electromagnetic (EM) parameters, microwave absorption (MA) capacity, and IR radiation characteristics can be tuned by adjusting the atomic ratios and outer layer thickness, resulting in excellent MA performance along with low IR emissivity. Thereinto, the product has an effective absorption bandwidth (EAB) of 7.20 GHz at 1.20 mm and reflection loss (RL) of −53.54 dB at 5.80 GHz. The core–shell FeCoNi@SnO2 MCCM modified by the SnO2 layer can enhance the EAB and RL values to 8.12 GHz (1.61 mm) and −65.55 dB (11.08 GHz) due to the increased interface polarization. Furthermore, thanks to the strong IR reflection of the SnO2 layer, the obtained composites achieve an IR emissivity of approximately 0.50. This work provides a straightforward for developing radar-IR compatible stealth materials.

Are there any differences in the retina and optic nerve anatomies in attention deficit hyperactivity disorder?

Aims/Purpose: To compare different macular, peripapillary and papillary parameters between attention deficit hyperactivity disorder (ADHD) and normotypical subjects.Methods: In this observational, prospective, case–control study a group of 50 subjects with ADHD were compared with a group of 50 normotypical subjects (controls). Both groups underwent a complete ophthalmological study and optical coherence tomography (OCT) measurements including thickness of the entire retina, inner and outer layers thickness at the macula using 1–3‐6 mm Early Treatment Diabetic Retinopathy Study (ETDRS) grid, peripapillary nerve fibre layer (pRFNL) thickness and Bruch's membrane opening‐minimum rim width (BMO‐MRW) parameters. Both eyes, the right and the left one, were compared independently between both groups.Results: When analysing the macula, it was seen a diffuse thinning of complete retina, inner retina and outer retina presenting symmetrical thinning patterns in both eyes in ADHD. The thickness of all pRNFL sectors were also significantly reduced in both eyes in ADHD in all the quadrants. However, BMO‐MRW parameters did not show any differences in any eye between both groups.Conclusions: Attention deficit hyperactivity disorder is associated with a diffuse thinning of the entire retina, inner retina and outer retina, furthermore pRNFL was also significantly reduced in both eyes.

Determination of the embryotoxic effects of propofol injected into eggs on the cerebellum and spinal cord using histologic methods: an animal study.

This study aims to determine the possible embryotoxic effects of propofol on the cerebellum and spinal cord using fertile chicken eggs. A total of 430 fertile eggs were divided into 5 groups: control, saline, 2.5 mg.kg-1, 12.5 mg.kg-1, and 37.5 mg.kg-1 propofol. Injections were made immediately before incubation via the air chamber. On the 15th, 18th, and 21st day of incubation, 6 embryos from each group were evaluated. Serial paraffin sections taken from the cerebellum and spinal cord were stained with hematoxylin-eosin, Kluver-Barrera, toluidine blue, and periodic acid-Schiff's reaction. The outer granular layer and total cortex thickness were measured, and the linear density of the Purkinje cells was determined. The ratios of the substantia grisea surface area to the total surface area of the spinal cord were calculated. The transverse and longitudinal diameters of the canalis centralis were also assessed. No structural malformation was observed in any embryos examined macroscopically. No significant difference was observed between the groups in terms of development and histologic organization of the cerebellum and spinal cord. However, on the 15th, 18th, and 21st day, the outer granular layer (p < 0.001 for all days) and the total cortex thickness (p < 0.01, p < 0.001, and p < 0.001, respectively) decreased significantly in different propofol dose groups in varying degrees in the cerebellum. Similarly, in the spinal cord, there were significant changes in the ratios of the substantia grisea surface area to the total surface area (p < 0.01 and p < 0.001, respectively). It was concluded that the in-ovo-administered propofol given immediately before incubation has adverse effects on the developing cerebellum and spinal cord. Therefore, it is important for anesthesiologists always to remain vigilant when treating female patients of childbearing age.

Липидный анализ слезной жидкости в диагностике дисфункции мейбомиевых желез

The tear film lipid layer plays a crucial role in maintaining ocular surface homeostasis by preventing excessive evaporation of the aqueous layer and reducing heat transfer from the corneal and conjunctival surface. The lipid composition of the tear film is unique and consists of two main layers: the outer (nonpolar lipids) and the inner (polar lipids). The thick outer layer of the tear film is composed of non-polar lipids that lack internal distributed charge, while the thin inner layer is formed by polar lipids with positive and negative charges at the ends of the molecule. Both types of lipids are synthesized in the meibomian glands (MG) and contribute to tear film stability. Meibomian gland dysfunction (MGD) alters the composition and physical properties of lipids, leading to pathological changes in both the MG and tear film. In meibomian gland dysfunction (MGD), the meibum thickens and acquires a higher melting point than normal. This leads to a decrease in the amount of nonpolar and amphiphilic lipids in the meibomian gland secretion and tear film. Consequently, the protective effect of the tear lipid layer is impaired, and its stability is compromised. Lipid mapping analyzes the lipid composition of biological samples, such as tear fluid, to study the mechanisms of the development and progression of various ocular surface diseases, including dry eye syndrome, MGD, and recurrent blepharoconjunctivitis. This method provides fundamental data on the properties of the tear film in various ocular surface diseases. It has the potential to establish hallmarks of disease course and develop personalized treatment approaches for specific clinical cases. KEYWORDS: tear, tear film lipids, ocular surface, meibomian gland dysfunction, lipid analysis. FOR CITATION: Takhauova L.R., Guseva A.A., Krylova A.A., Krivosheina O.I. Lipid analysis of tear fluid as a diagnostic tool for meibomian gland dysfunction. Russian Journal of Clinical Ophthalmology. 2024;24(2):83–87 (in Russ.). DOI: 10.32364/2311-7729-2024-24-2-7.

Enhanced corrosion resistance of Mg alloy embedded in Cl--containing Portland cement with the formation of CaCO3-coated Mg(Al)O passive film via one-step pulse electrodeposition

In this study, a novel CaCO3/Mg(Al)O coating system was successfully synthesized via one-step pulse electrodeposition. The thickness of inner passivation layer and outer CaCO3 layer was tailored by modulating the pulse voltage. Anticorrosion performance of the coated Mg alloy was assessed by both electrochemical methods and embedment tests. The coated Mg alloy demonstrated improved corrosion resistance, attributed to the synergistic impact of a compact outer CaCO3 layer and an Al-assisted inner passivation layer. Both layers' quality primarily governed the alloy's anticorrosion performance. Remarkably, embedment tests revealed a re-passivation phenomenon instead of corrosion, with its mechanism discussed comprehensively.

Visual Acuity-Related Outer Retinal Structural Parameters on Swept Source Optical Coherence Tomography and Angiography in XLRS Patients and Carriers.

To assess the quantitative differences in vessel density and retinal thickness of X-linked retinoschisis (XLRS) patients and RS1 mutation carriers, and the correlation with best-corrected visual acuity (BCVA) with swept source optical coherence tomography (SS-OCT) and OCT angiography (OCTA). We analyzed the correlation between the BCVA of XLRS patients and the SS-OCT and OCTA findings including the detailed structural characteristics of XLRS patients. Besides the schitic changes in various retinal layers, the structural disturbance of outer retina was universally found. In 29 eyes included in the quantitative analysis, XLRS patients showed lower vessel density of the superficial capillary plexus, deep capillary plexus and lower thickness of the outer nuclear layer. BCVA was correlated with the thickness of the outer plexiform layer and outer nuclear layer and the thickness from the outer limiting membrane to the retinal pigment epithelium. Carriers showed higher thickness of outer plexiform layer and smaller foveal avascular zone area. SS-OCT and OCTA could identify the pathological alterations of the individual retinal layers and capillaries, which could pinpoint the exact location of the damages related to visual impairment. In the carriers, the subtle alterations that can be detected with SS-OCT, despite their normal visual acuity, may be caused by the lyonization. Swept source optical coherence tomography can be used as an efficient technique to expose the retinal damage related to visual impairment for prognosis and follow-up.

Highly durable and flexible transparent electrode on PET based on copper and cupronickel multilayer

Multilayer grid electrodes consisting of Cu0.7Ni0.3/Cu/Cu0.7Ni0.3 utilize the high conductivity of Cu to realize low electrical resistance and the high corrosion resistance of CuNi to improve reliability. The effect of thickness of outer CuNi layer on corrosion resistance and visibility was investigated. Samples prepared with 2 μm line width on PET having grid mesh side length of 300 μm, and 60° internal angle with 280 nm thickness showed a transmittance of 90.1% at 550 nm and sheet resistance of 2.4 Ω/□ after grid pattern formation. The low process temperature enabled electrode formation on thin substrate, 23 μm-thick PET and accomplish highly durable and flexible electrode on PET. The superior bending properties showed no change in sheet resistance after 200 000 cycles of outer/inner fatigue bending tests at 3 mm radius of curvature. Additionally, the potential for foldable usage was further supported by demonstrating the ability to form electrodes on both sides of the film.

The Role of Sphingosine-1-Phosphate Receptor 2 in Mouse Retina Light Responses.

The bioactive sphingolipid sphingosine-1-phosphate (S1P) acts as a ligand for a family of G protein-coupled S1P receptors (S1PR1-5) to participate in a variety of signaling pathways. However, their specific roles in the neural retina remain unclear. We previously showed that S1P receptor subtype 2 (S1PR2) is expressed in murine retinas, primarily in photoreceptors and bipolar cells, and its expression is altered by retinal stress. This study aims to elucidate the role of S1PR2 in the mouse retina. We examined light responses by electroretinography (ERG), structural differences by optical coherence tomography (OCT), and protein levels by immunohistochemistry (IHC) in wild-type (WT) and S1PR2 knockout (KO) mice at various ages between 3 and 6 months. We found that a- and b-wave responses significantly increased at flash intensities between 400~2000 and 4~2000 cd.s/m2, respectively, in S1PR2 KO mice relative to those of WT controls at baseline. S1PR2 KO mice also exhibited significantly increased retinal nerve fiber layer (RNFL) and outer plexiform layer (OPL) thickness by OCT relative to the WT. Finally, in S1PR2 KO mice, we observed differential labeling of synaptic markers by immunohistochemistry (IHC) and quantitative reverse transcription polymerase chain reaction (RT-qPCR). These results suggest a specific involvement of S1PR2 in the structure and synaptic organization of the retina and a potential role in light-mediated functioning of the retina.