Incheon National University

Flow synthesis is emerging as a powerful method for the rapid and reproducible synthesis of conjugated polymers. However, chain scission is a potential side reaction that can limit the maximum obtainable molecular weight. In this report, the kinetics of conjugated polymer degradation in flow were studied using methods based on molecular weight models and monitoring the refractive index at the incipient portions of size‐exclusion chromatography peaks. After evaluating the suitability of these methods, they were used to calculate degradation rate constants. In addition to observing that degradation rates increased with increasing molecular weight, by studying the conjugated polymers PTB7 and PTB7‐Th, we found that degradation rates were also influenced by the size of the side chain on the conjugated polymer. These results provide new support for the mechanochemical nature of degradation and are expected to aid in the development of new flow syntheses for conjugated polymers.

How is economic inequality associated with gender inequality at the individual level? Even though previous literature has broadened our understanding of the impacts of economic inequality at the national level, the influence of attitudes toward income inequality on the attitudes toward gender equality has not been fully examined at the individual level. To contribute to the previous literature, relying on the World Value Survey dataset in Wave 5, 6, and 7, this article unveils the relationship between economic inequality and gender inequality at the individual level with the cases of 17 Asia-Pacific countries. Estimating ordered logistic regression models, this article demonstrates that there is a statistically and substantially significant relationship between the justification of income inequality on the confidence in the women’s movements. More interestingly, we find that male respondents compared to their female counterparts are more susceptible to the changes in the justification of income inequality. Our research advances the literature on the impacts of economic inequality concerning individual perspectives. At the same time, this article extends previous research on the influence of economic inequality by showing that the role of economic inequality in determining people’s attitudes toward gender equality is conditioned by the gender of individuals.

DNA possesses unique abilities such as informational self-assembly and digital data storage with high density. Here, we demonstrate the deep-UV photolithography for DNA data storage with diverse functionalities such as content addressing, identification, and long-term storage. Using fluorescent DNA hybridization for DNA deep-UV photolithography, single-strand breaks (SSB) showed clearer patterns. DNA deep-UV photolithography with fluorescent DNA hybridization created a quick response (QR) pattern, which has the functionality of content addressing. The fluorescent DNA QR patterns, which were created by SSB, were linked to different informational websites, using smartphone QR image applications. Furthermore, a sentence was encoded in a 29 × 29-pixel QR pattern with a Reed-Solomon error correction code, and DNA sequences were synthesized with fluorescence. The fluorescent DNA sequences were selectively hybridized on the QR pattern substrate, and the patterns were synthesized using fluorescent dNTP. The fluorescent QR DNA was synthesized using primers and patterned on the substrate for DNA data storage. Even though we provided limited demonstrations such as data capacity and content image for DNA data storage, the use of DNA photolithography to create and store 2D pattern information could be extended to diverse applications for random access storage.

Colloidal semiconductor nanocrystals (NCs) of ternary I–III–VI compounds are promising luminescent materials for photonic and optoelectronic applications. However, defect‐induced broad trap emission dominates, and achieving band‐edge photoluminescence (PL) without appropriate shell coating remains challenging. This study introduces a synthesis route and optical characterization results of weakly quantum‐confined In‐rich AgInS2 NCs, which exhibit spectrally narrow band‐edge PL in the red spectral range. Leveraging precursor stoichiometry and growth condition optimization, band‐edge emissive AgInS2 NCs with mitigated defect emission are realized. Structural analysis of the NCs reveals a stoichiometric AgInS2 core surrounded by an In‐enriched surface layer, facilitating efficient exciton radiative relaxation pathways. With NC diameters approaching the exciton Bohr diameter of the bulk semiconductor, the PL peak energies of AgInS2 NCs align closely with the bulk bandgap (2.0 eV), and these NCs exhibit spectrally pure emission with reduced batch‐to‐batch variation for red emission. The band‐edge PL properties are remarkably improved by coating a GaSx shell that effectively suppresses the residual trap emission and reduces nonradiative recombination, thereby enhancing the overall emission efficiency. These findings provide new insights into composition‐controlled optical property regulation of ternary semiconductor NCs and underscore their potential for photonic and optoelectronic applications.

This study presents a prototypical platform to sense fundamental low-energy excitations in µm-sized two-dimensional (2D) materials with sub-millimeter (mm)-wavelength electromagnetic (EM) radiation by harnessing a single antenna. Despite the large difference in diffraction-limited focusing of sub-mm-wavelength light and the µm-sized 2D materials, strong light-matter interaction is facilitated by specially designed antenna structures (slot or bowtie antennas) with the sample positioned in regions of enhanced three-dimensional (3D) field confinement. The interaction of the resonant meta-atoms and the sample of interest, here µm-sized graphite, MoS2, and hBN modifies the meta-atom’s dielectric properties, and hence, the single antenna’s transmittance changes remarkably in the presence of the µm-sized samples finely positioned by the dry transfer method. This result paves the route toward investigating low-energy excitations in various 2D materials in the regime of mm-wavelength EM waves.

Rational design of catalytic nanomaterials is essential for developing high‐performance fuel cell catalysts. However, structural degradation and elemental dissolution during operation pose significant challenges to achieving long‐term stability. Herein, the development of multi‐grained NiPt nanocatalysts featuring an atomically ordered Ni3Pt5 phase within intragrain is reported. Ultrasound‐assisted synthesis facilitates atomic transposition by supplying sufficient diffusion energy along grain boundaries, enabling unprecedented phase formation. The Ni3Pt5 embedded nanocatalysts exhibit outstanding proton exchange membrane fuel cell performance under both light‐duty and heavy‐duty vehicle conditions, with significantly reduced Ni dissolution. Under light‐duty vehicle conditions, the catalyst achieves a mass activity of 0.94 A mgPt⁻¹ and a 421 mA cm⁻² current density (@ 0.8 V in air), retaining 78% of its initial mass activity after long‐term operation. Under heavy‐duty vehicle conditions, the multi‐grained nanocrystal demonstrates only an 8% decrease in Pt utilization, a 5% power loss, and a 13 mV voltage drop, surpassing U.S. Department of Energy (DOE) durability targets. This study underscores the critical role of the atomically ordered Ni3Pt5 phase in stabilizing multi‐grained NiPt nanocrystals, enhancing both durability and catalytic activity. These findings establish Ni3Pt5 embedded nanocatalysts as promising candidate for next‐generation PEMFC applications, addressing key challenges in long‐term operation.

Typically, two-stage stochastic programs have been modeled and solved based on the finite support assumption, but the large number of scenarios makes it hard to solve, and there also are potential risks of inaccurate estimation of underlying distribution. In this paper, to mitigate the drawbacks, we present a novel risk-averse two-stage stochastic program with finite support, which we call partition-based risk-averse two-stage stochastic program. In the program, a set of scenarios is partitioned into several groups, and the second-stage cost is defined as the expectation of risk levels for all of the groups. In particular, the conditional value-at-risk is considered as a risk measure for each group, and so the risk level of the model is affected by a quantile parameter or a partition of a given set of scenarios. In order to solve the model exactly for a given partition, a column-and-constraint generation algorithm is proposed. In addition, a scenario partitioning algorithm to enable the risk level of the model to be close to a given target is devised, and partitioning schemes for combining it with the proposed column-and-constraint generation algorithm are proposed. Extensive numerical experiments were performed that demonstrated the effectiveness of the proposed partitioning schemes and the efficiency of the proposed solution approach.

Background Predicting immune checkpoint inhibitor (ICI) response remains a significant challenge in cancer immunotherapy. Many existing approaches rely on differential gene expression analysis or predefined immune signatures, which may fail to capture the complex regulatory mechanisms underlying immune response. Network-based models attempt to integrate biological interactions, but they often lack a quantitative framework to assess how individual genes contribute within pathways, limiting the specificity and interpretability of biomarkers. Given these limitations, we developed PathNetDRP, a framework that integrates biological pathways, protein-protein interaction networks, and machine learning to identify functionally relevant biomarkers for ICI response prediction. Results We introduce PathNetDRP, a novel biomarker discovery approach that applies the PageRank algorithm to prioritize ICI-associated genes, maps them to relevant biological pathways, and calculates PathNetGene scores to quantify their contribution to immune response. Unlike conventional methods that focus solely on gene expression differences, PathNetDRP systematically incorporates biological context to improve biomarker selection. Validation across multiple independent cancer cohorts showed that PathNetDRP achieved strong predictive performance, with cross-validation the area under the receiver operating characteristic curves increasing from 0.780 to 0.940. Interestingly, PathNetDRP did not merely improve predictive accuracy; it also provided insights into key immune-related pathways, reinforcing its potential for identifying clinically relevant biomarkers. Conclusion The biomarkers identified by PathNetDRP demonstrated robust predictive performance across cross-validation and independent validation datasets, suggesting their potential utility in clinical applications. Furthermore, enrichment analysis highlighted key immune-related pathways, providing a deeper understanding of their role in ICI response regulation. While these findings underscore the promise of PathNetDRP, future work will explore the integration of additional predictive features, such as tumor mutational burden and microsatellite instability, to further refine its applicability.

The swimming crab, Portunus trituberculatus, supports the world’s largest crab fishery. Hard-shell crabs have fully developed exoskeletons and are rich in meat, while soft-shell crabs, which have recently molted, contain less meat. To determine their nutritional status and feeding behavior, we measured amino acids (AAs), organic carbon (OC), δ¹³C, δ¹⁵N, and ²¹⁰Po in the muscle of hard- and soft-shell crabs collected from the eastern Yellow Sea in May 2024. The concentrations of total AAs (TAAs) and OC were approximately 1.4 and 1.3 times higher, respectively, in hard-shell crabs than in soft-shell crabs. A significant positive correlation between TAAs and OC (r² = 0.74, p < 0.05) suggests that hard-shell crabs have a better nutritional status, due to the consumption of higher-quality food. Hard-shell crabs also exhibited significantly higher δ¹³C values and ²¹⁰Po activities than soft-shell crabs, whereas δ¹⁵N values showed no significant difference between the two groups. These results indicate that hard-shell crabs primarily consume higher trophic-level prey compared with soft-shell crabs, despite both occupying the same trophic position. Thus, this difference in food sources may be influenced by post-molt hiding behavior in soft-shell crabs, which limits access to high-trophic prey, or alternatively, by competition for food in coastal waters.

This study presents several multivariate Generalizability theory designs for analyzing automatic item‐generated (AIG) based test forms. The study used real data to illustrate the analysis procedure and discuss practical considerations. We collected the data from two groups of students, each group receiving a different form generated by AIG. A total of 74 students participated in this study and responded to AIG‐based test forms. Then, we analyzed the data using four distinct designs based on the data collection design, and conceptualization of true scores and measurement conditions over hypothetical replications. This study also examined the theoretical relationships among the four data collection designs and highlighted the potential impact of confounding between item templates and item clones.

Modulating the oxidation states of transition metal species is a practical approach to enhance redox activity and increase the number of active sites in electrode materials. Herein, we describe a simple one-step hydrothermal approach to prepare CoxSy with two different phases, cobalt pyrite (CoS2) and cobalt pentlandite (Co9S8), to explain the influence of material microstructure and properties on electrochemical performance. The as-prepared CoS2 and Co9S8 were investigated as symmetric supercapacitor (SC) devices for potential energy storage applications. Co9S8 exhibited the highest specific gravimetric capacitance of 14.12 Fg⁻¹ at 0.2 mAcm⁻² with capacitance retention of 91.3% after 10,000 cycles, indicating robust cycling stability. In addition, the Co9S8 SC device showed the highest energy (E) and power (P) density of 9.14 Whkg⁻¹ and 0.23 kWkg⁻¹. These results highlight a simple approach of tailoring different phase syntheses of CoxSy structure toward high-performance electrode material for energy storage and conversion.

Alzheimer’s disease (AD) is a complex neurodegenerative disorder characterized by cognitive decline, oxidative stress, neuroinflammation, amyloid-beta (Aβ) accumulation, and tau protein hyperphosphorylation. In this study, we synthesized novel Ramalin derivatives and evaluated their therapeutic potential against AD, focusing on antioxidant, anti-inflammatory, and neuroprotective activities. RA-2OMe, RA-4OMe, RA-2CF3, and RA-4OCF3 showed strong antioxidant effects, while RA-2OMe exhibited potent NO and NLRP3 inhibition (~20%). RA-NAP, RA-PYD, and RA-2Q showed moderate anti-inflammatory activity. BACE-1 inhibition was significant in RA-3CF3, RA-NAP, and RA-PYD, with IC50 values lower than that of positive control, indicating greater inhibitory potency. RA-NAP and RA-PYD effectively inhibited both Aβ and tau aggregation, highlighting their multi-target potential for AD therapy. These findings indicate that Ramalin derivatives exhibit potential for multi-target activity in AD treatment. However, further studies on their pharmacokinetics, in vivo efficacy, and long-term safety are required to confirm their therapeutic applicability.

Simultaneous two-photon imaging and electrophysiological recordings offer considerable potential for advancing neurological research and therapies. However, traditional metal-based neural interfaces suffer from photoelectric artifacts, while existing transparent implants rely on opaque interconnect lines to address conductivity limitations. Herein, we developed an optically transparent poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) neural electrode array with transparent electrodes and interconnect lines. Through a formamide, phosphoric acid, and ethylene glycol treatment, the metal-free PEDOT:PSS array achieved an impedance of 45.8 kΩ (at 1 kHz) even with a 20 × 20 µm² size. This advanced performance surpasses previous metal-free transparent neural interfaces and facilitates precise electrophysiological recordings, including extracellular action potentials and low-noise local field potentials. In vivo experiments demonstrated artifact-free two-photon imaging and reliable neural signal acquisition, while biocompatibility tests confirmed negligible cytotoxicity or immune responses. The developed metal-free PEDOT:PSS array provides a robust platform for neural recording and bioimaging, representing an advancement in transparent neural interface technology and integrated optical modalities.

Iris bungei Maxim., a plant native to the desert grasslands of the Inner Mongolian Plateau and traditionally used in Mongolian medicine, has been shown to influence adipocyte differentiation in white adipose tissue. However, its effects on brown adipocyte differentiation have not been previously explored. This study aimed to investigate the effects of Iris bungei Maxim. (IB) extract on brown adipocyte differentiation, focusing on lipid accumulation, gene expression, mitochondrial biogenesis, and functionality. Immortalized murine brown preadipocytes were treated with IB extract during differentiation. Lipid accumulation, expression of brown adipocyte-specific genes, and mitochondrial biogenesis (MitoTracker Red staining, mitochondrial DNA content, oxidative phosphorylation protein levels) were evaluated. Additionally, mitochondrial respiration and isoproterenol-induced UCP-1 expression were analyzed to assess functional effects. Bioactive compounds in the IB extract were identified using feature-based molecular networking (FBMN) with the Global Natural Products Social Molecular Networking (GNPS). The IB extract significantly enhanced brown adipocyte differentiation, as evidenced by increased lipid accumulation and upregulation of brown adipocyte-specific genes, such as UCP-1, PGC-1α, and PRDM16. Moreover, mitochondrial biogenesis was notably elevated, as indicated by enhanced MitoTracker Red staining, increased mitochondrial DNA content, and upregulated oxidative phosphorylation protein expression. The extract also improved mitochondrial respiration, suggesting enhanced mitochondrial functionality. Furthermore, the IB extract amplified isoproterenol-induced UCP-1 expression, indicating its potential role in thermogenesis regulation. Additionally, FBMN-GNPS analysis identified the chemical constituents in the IB extract by mass replication in the spectral matching to those in online databanks. These findings suggest that the methanol extract of IB could be a promising agent for promoting brown adipocyte differentiation and enhancing mitochondrial activity, with potential applications in managing obesity and metabolic disorders.