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Abstract A pioneering integration of oxide semiconductor memristors with optoelectronic features is presented, surpassing binary limitations to realize multi‐valued synaptic operations. Through Pt/Ga2O3/Pt memristors, their structural and electronic attributes via atomic force microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy are explored. Demonstrating unipolar resistance switching with remarkable endurance and retention, the devices exhibit intricate light‐resistance correlations, yielding substantial photoelectric effects in distinct resistance states. Investigating synaptic behaviors, potentiation, and depression akin to biological synapses are unveiled, facilitating learning and memory processes. The standout achievement lies in attaining quaternary memory storage within a single device. Empirical data and simulations validate this concept, showcasing the potential for encoding and sustaining multiple memory states. This innovation heralds transformative possibilities, emphasizing oxide semiconductor memristors as a gateway to quaternary memory storage and enhanced synaptic functions. In essence, this work pioneers optoelectronic synaptic devices with expanded memory capabilities.

Advances in nanophotonics have created numerous pathways for light–matter interactions in nanometer scale, enriched by physical and chemical mechanisms. Over the avenue, electrically tunable photonic response is highly desired for optical encryption, optical switch, and structural color display. However, the perceived obstacle, which lies in the energy-efficient tuning mechanism and/or its weak light–matter interaction, is treated as a barrier. Here, we introduce electrochromic nanopixels made of hybrid nanowires integrated with polyaniline (PANI). The device shows optical duality between two resonators: (i) surface plasmon polariton (SPP)-induced waveguide (wavelength-selective absorber) and (ii) ultrathin resonator (broadband absorber). With switching effect of between resonant modes, we achieve enhanced chromatic variation spanning from red to green and blue while operating at a sub-1-volt level, ensuring compatibility with the CMOS voltage range. This modulation is achieved by improving the light–matter interaction, effectively harnessing the intrinsic optical property transition of PANI from lossy to dielectric in response to the redox states. In our experimental approach, we successfully scaled up device fabrication to an 8-inch wafer, tailoring the nanowire array to different dimensions for optical information encryption. Demonstrating distinct chromaticity modulation, we achieve optical encryption of multiple data bits, up to 8 bits per unit cell. By capitalizing on the remarkable sensitivity to the angular dependence of the waveguiding mode, we further enhance the information capacity to an impressive 10 bits per unit cell.

Abstract Identifying environmental effects on the reproduction cycle and sex hormones is essential for ensuring the sustainable productivity of Pacific bluefin tuna (PBT, Thunnus orientalis) aquaculture. In the present study, 70 PBTs, commercially farmed in sea cages near Yokjido Island, South Korea, were investigated from April 2020 to March 2021. Environmental data, including water temperature and photoperiod duration, were collected. The gonadosomatic index (GSI) was calculated, and male and female maturity stages were classified monthly in proportions based on histological analysis of the gonads. Male and female gonadal developmental stages were classified into four major stages. Mature male and female PBTs were observed from May to August and June to August, respectively. Monthly changes in sex steroid hormone levels in PBT plasma were evaluated. The GSI and sex steroid hormones of males and females increased in May, peaked in June, and decreased thereafter. Our results confirmed the reproductive potential of farmed PBT and verified that reproductive maturity is reached in July. This study, to the best of our knowledge, is the first to investigate the reproductive biology of PBT in South Korea, and our results constitute a reference for future research on PBT aquaculture.

This study investigates the effects of sway and roll excitations on sloshing liquid loads in a tank, using Ansys Fluent software. The model considered in the study is a 1:50 scaled membrane-type tank, based on a KC-1 membrane LNG tank designed by Korea Gas Corporation (KOGAS). The volume of fluid (VOF) method is used to track the free surface inside the tank, and the standard k-ε model is applied to express the turbulent flow of the liquid. To explore the motion of the tank under excitation, a user-defined function (UDF) and a dynamic mesh technique are employed to control the external forces exerted on the tank through its motion. The results, in the form of time series data on the sloshing pressures in the tank under pure sway, roll, and coupled sway-roll, are analysed, with specific ranges for the excitation amplitudes and frequencies. We show that variations in excitation frequency and amplitude significantly influence the sloshing loads. Sloshing loads are found to intensify when the excitation frequency matches the tank’s primary natural frequency, 1.0 ω1′. Furthermore, with coupled sway-roll excitations, the sloshing loads are weakened when the sway and roll are in-phase and are intensified when these are out-of-phase. Fast Fourier transform analysis provides insights into the frequency domain, showing that the dominant frequency is 0.88 Hz and it is approximately equal to the tank’s primary natural frequency, 1.0 ω1′.

A 10-week feeding trial was conducted to evaluate the effects of different feeding rates on growth performance, nutrient deposition, plasma metabolite, and immunity of juvenile starry flounder. Fish (initial mean body weight, 183.6 ± 2.3 g) were subjected to eight feeding rates (0.4, 0.8, 1.2, 1.6, 2.0, 2.4, 2.8, and 3.2% body weight/day [BW/d]) with a commercial diet containing 53.5% crude protein and 10.2% crude lipid. After the feeding trial, fish growth increased significantly (p < 0.05) from 0.4% to 2.0% BW/d, with no significant differences being observed beyond 2.0% BW/d. Protein and lipid gains in the whole body and liver of the fish fed 2.0–3.2% BW/d were significantly (p < 0.05) higher than those of the fish fed 0.4% and 0.8% BW/d. Conversely, protein retention in the whole body and the liver decreased with an increased feeding rate. Lysozyme activity was significantly (p < 0.05) higher in the fish fed 1.6–2.8% BW/d than in those fed 0.4–1.2% BW/d. The best-fit model analyses for optimum feeding rate (OFR) revealed that the estimate for each parameter varied between 0.7% (feed conversion ratio) and 3.1% (lipid gain in carcass) BW/d. The OFR for productivity (weight gain) and enhanced innate immunity (lysozyme) were estimated at 2.4% and 1.7% BW/d, respectively.

Presbycusis, also referred to as age-related hearing loss (ARHL), is a multifaceted condition caused by the natural aging process affecting the auditory system. Genome-wide association studies (GWAS) in human populations can identify potential genes linked to ARHL. Despite this, our knowledge of the biochemical and molecular mechanisms behind the condition remains incomplete. This study aims to evaluate a potential protective tool for ARHL treatment by comparing human blood-based target gene-miRNA associations regulated in ARHL. To identify promising target genes for ARHL, we utilized an mRNA assay. To determine the role of miRNA in ARHL, we investigated the expression profile of miRNA in whole blood in ARHL patients with real-time polymerase chain reaction (RT-qPCR). A reporter gene assay was performed to confirm the regulation of candidate genes by microRNA. Through RT-qPCR validation analysis, we finally confirmed the relationship between ARHL and the role of the interferon-gamma (IFNG) gene. This gene can be regarded as an age-related gene. Through gene ontology (GO) analysis, it has been found that these genes are enriched in pathways related to apoptosis. Among them, IFNG induces an inflammatory response, apoptotic cell death, and cellular senescence. We found that miR-409-3p downregulates the expression of the IFNG in vitro. In addition, the downregulation of the IFNG by miRNA 409-3p promoted cell apoptosis and suppressed proliferation. In conclusion, our study produced gene signatures and associated microRNA regulation that could be a protective key for ARHL patients. IFNG genes and miR-409-3p should be investigated for their usefulness as a new biomarker for treatment modality.

Abstract Human-machine interface has been considered as a prominent technology for numerous smart applications due to their direct communication between humans and machines. In particular, wearable electronic skins with a free form factor have received a lot of attention due to their excellent adherence to rough and wrinkled surfaces such as human skin and internal organs. However, most of the e-skins reported to date have some disadvantages in terms of mechanical instability and accumulation of by-products at the interface between the human skin and the device. Here, we report a mechanically stable e-skin via a newly designed pattern named the “eyes.” The ingeniously designed pattern of the eyes allowed mechanical stress and strain to be dissipated more effectively than other previously reported patterns. E-skin permeability of by-product was experimentally confirmed through sweat removal tests, showing superior sweat permeability compared to conventional e-skins. Finally, the real-time monitoring of the body temperature was carried out using our resistive-type thermometer in the e-skin.

Abstract Background Bioplastics are attracting considerable attention, owing to the increase in non-degradable waste. Using microorganisms to degrade bioplastics is a promising strategy for reducing non-degradable plastic waste. However, maintaining bacterial viability and activity during culture and storage remains challenging. With the use of conventional methods, cell viability and activity was lost; therefore, these conditions need to be optimized for the practical application of microorganisms in bioplastic degradation. Therefore, we aimed to optimize the feasibility of the lyophilization method for convenient storage and direct use. In addition, we incoporated protective reagents to increase the viability and activity of lyophilized microorganisms. By selecting and applying the best protective reagents for the lyophilization process and the effects of additives on the growth and PHB-degrading activity of strains were analyzed after lyophilization. For developing the lyophilization method for protecting degradation activity, it may promote practical applications of bioplastic-degrading bacteria. Results In this study, the polyhydroxybutyrate (PHB)-degrading strain, Bacillus sp. JY14 was lyophilized with the use of various sugars as protective reagents. Among the carbon sources tested, raffinose was associated with the highest cell survival rate (12.1%). Moreover, 7% of raffionose showed the highest PHB degradation yield (92.1%). Therefore, raffinose was selected as the most effective protective reagent. Also, bacterial activity was successfully maintained, with raffinose, under different storage temperatures and period. Conclusions This study highlights lyophilization as an efficient microorganism storage method to enhance the applicability of bioplastic-degrading bacterial strains. The approach developed herein can be further studied and used to promote the application of microorganisms in bioplastic degradation.