Pohang University of Science and Technology

For five decades, Mussel Watch has provided an unparalleled record of coastal contamination using bivalve sentinels. However, contemporary marine pollution is increasingly complex, involving chemical mixtures modulated by climate change and tightly linked to ecosystems and human health. Traditional pollutant-by-pollutant monitoring approaches, while essential for tracking regulatory contaminants, are poorly suited to capture mixture effects, emerging contaminants, and cumulative exposures, which characterize real-world environmental risks. This Perspective paper reassesses Mussel Watch through the lenses of the chemical exposome and One Health frameworks. We argue that the program could evolve from a primarily descriptive monitoring system into a mechanistic observatory capable of linking environmental exposures to biological responses and ecosystem-level processes. Achieving this transition requires integrating emerging tools-including non-traditional stable isotopes, high-resolution non-target screening, and omics-based biomarkers-to better characterize complex exposure patterns and their biological consequences. We propose a dual-track architecture in which long-term routine monitoring is maintained to preserve the historical record, while a complementary research track supports hypothesis-driven investigations into biogeochemical transformation, exposure pathways, mixture effects, and biological responses. By combining these approaches, Mussel Watch could strengthen its capacity to detect emerging risks, support mechanistic understanding, and enhance the policy relevance of coastal monitoring in a rapidly changing environment.

Dissimilar fusion welding between NiTi shape memory alloy and AlCoCrFeNi 2.1 , eutectic high entropy alloy was achieved using a combination of Nb and Cu interlayers. Both base metals exhibit unique properties that complement each other making them attractive for integration in smart systems. However, direct joining of these materials is not feasible due to the formation of brittle intermetallic compounds that compromise the joint integrity. Thus, to avoid this metallurgical issue dissolution of the Nb and Cu interlayers promoted elemental intermixing and altered solidification pathways, leading to the formation and intensification of topologically close-packed phases. Phase evolution was assessed through thermodynamic CALPHAD simulations and validated using synchrotron X-ray diffraction, while further microstructural characterization employed backscattered electron imaging and energy dispersive spectroscopy. The weld exhibited pronounced spatial heterogeneity, with a peak hardness of 856 HV 0.3 near the NiTi-side interfacial region, consistent with enrichment of TCP phases and Ti-rich intermetallics. Tensile testing showed fracture at an ultimate tensile strength of 372 MPa and a fracture strain of 1.11%, with crack initiation in the hardened interfacial region followed by mixed-mode fracture toward the fusion zone. Although tensile ductility remains limited, the multi-interlayer strategy enabled defect-free joint formation and confined embrittlement to a narrow region compared with direct joining. • Fusion welding of NiTi shape memory alloy with AlCoCrFeNi 2.1 eutectic high entropy alloy is investigated using multiple interlayers to minimize intermetallic formation. • Interlayer dissolution produced a heterogeneous microstructure, promoting the formation of topologically close-packed phases that influenced the mechanical behaviour of the joint. • CALPHAD simulations and synchrotron X-ray diffraction revealed the impact of elemental intermixing and phase evolution across the composite weld zone.

Abstract Objectives To reveal the underlying micro-mechanisms of deformation and strengthening in particle-reinforced aluminum matrix composites (PRAMCs) with different microstructures. Methods A nonlocal physically-based crystal plasticity (CP) model is developed for a TiB2/Al–Zn–Mg–Cu composite with varied particle and grain structures. Results TiB2 particles interrupt the inherent deformation bands in the particle-free matrix, induce additional intragranular deformation bands, and increase the number of activated intragranular slip systems. Conclusion Particle-induced constraint and elastic-modulus mismatch intensify local strain/stress gradients and promote geometrically necessary dislocation (GND) accumulation, thereby exacerbating deformation inhomogeneity; the effects of particle size and grain size are secondary compared with these mechanisms. Particles affect strain partitioning and GND distribution more strongly in coarse grains than in fine grains, whereas crystal orientation dominates stress partitioning. Fine particles are more effective than coarse particles in dispersing inherent strain concentrations within the matrix. The proposed model reproduces these microstructural characteristics. This work provides novel insights into the microstructural design and strengthening mechanisms of PRAMCs for optimizing high performance.

Tellurium (Te) is increasingly gaining attention as a scalable p-type channel material owing to its inherently high carrier mobility and ambient stability. However, in sub-5 nm Te channels, high contact resistance remains a major obstacle to achieving high-performance device operation. In this study, an estimated contact resistance of ≈1.7 kΩ·μm is obtained in 4 nm-thick Te channels by engineering the band structure in the source and drain (S/D) regions using a raised source and drain (RSD) structure. To isolate intrinsic contact behavior, electrical measurements are conducted at 77 K, in which thermally activated defect states are suppressed, and carrier injection is dominated by the metal-semiconductor interface. Transport characterization reveals a more than 17-fold increase in on-state current and a more than 50-fold reduction in contact resistance relative to Te devices without the RSD structure. This enhancement is attributed to selectively increasing the Te thickness at the S/D terminals, which tunes the bandgap by thickness-dependent modulation. The resulting RSD architecture enhances tunneling current by narrowing the barrier width─modulated by gate bias. This scalable, low-temperature approach offers broad applicability to other ultrathin channel materials.

Biological production of adipic acid, a crucial building block in nylon and polymer manufacturing, from renewable feedstocks has attracted attention as a sustainable alternative to the traditional petrochemical production. The enzymatic conversion of ε-caprolactone into adipic acid via alcohol dehydrogenase (ADH2) and aldehyde dehydrogenase (ALDH) represents a promising route due to its short pathway and high theoretical yield. To optimize this conversion route in Escherichia coli and enhance conversion efficiency, we constructed an adipic acid-responsive biosensor for high-throughput screening. By systematically optimizing the biosensor system, we achieved a 7.15-fold dynamic range. Using this biosensor system, we performed directed evolution of the low-activity ALDH and identified variants with improved conversion performance. The K23Q mutant showed a 2.33-fold increase in adipic acid conversion efficiency and subsequent fed-batch fermentation achieved 30.1 g/L of adipic acid production from ε-caprolactone with 92.7% of theoretical maximum yield. These results demonstrate the potential of biosensor-guided enzyme engineering to enhance catalytic efficiency and support the sustainable biological production of adipic acid.

Interferon regulatory factor 3 (IRF3) is classically recognized for antiviral immunity, yet emerging evidence implicates it in sterile inflammation. This study investigated whether IRF3 regulates macrophage-stromal signaling driving corneal pathology and evaluated the therapeutic potential of targeting IRF3. In vitro assays utilized human macrophages stimulated with lipopolysaccharide (LPS) and interferon-γ (IFNγ) to generate an inflammatory macrophage population (Mϕ-LPS/IFNγ cells), along with primary human corneal stromal fibroblasts (HCFs) stimulated with LPS. IRF3 was silenced by small interfering RNA (siRNA), and inflammatory mediators and toll-like receptor 4 (TLR4)/MyD88 transcripts were quantified. Macrophage-HCF interactions were assessed in Transwell cocultures. In vivo, Irf3-/- and wild-type mice underwent corneal epithelial debridement followed by topical LPS to evaluate corneal opacity, fibrotic markers, cytokine expression, and myeloid-cell subsets. Piceatannol, a stilbenoid compound known to inhibit IRF3, was tested in vitro and as topical eye drops. IRF3 expression was upregulated in both macrophages and HCFs under inflammatory conditions. Silencing IRF3 significantly reduced inflammatory cytokines, including CXCL10, and decreased TLR4-associated transcripts in HCFs. In cocultures, IRF3-silenced macrophages partially attenuated HCF activation. In vivo, Irf3 deficiency markedly reduced LPS-induced corneal opacity, stromal inflammatory transcripts, monocyte recruitment, and macrophage-associated markers. Piceatannol suppressed IRF3-dependent inflammatory responses in vitro and, when applied topically, reduced corneal Irf3 expression and myeloid/inflammatory signatures. IRF3 is a pivotal regulator of innate immune-driven stromal inflammation and opacity. Both genetic and pharmacologic inhibition of IRF3 attenuated cytokine and myeloid responses, suggesting that targeting IRF3, potentially via piceatannol (PIC), offers a therapeutic strategy for preserving corneal transparency.

ABSTRACT Self‐assembled monolayers (SAMs) have emerged as promising hole‐transporting layers (HTLs) for organic photovoltaics (OPVs). However, their practical application is often hindered by inherent aggregation issues and the difficulty of forming uniform thin films over large areas. To overcome these limitations, we developed a novel interfacial modification process using nicotinic hydrazide (NH) designed to eliminate residual SAM aggregates. We demonstrate that NH effectively eliminates the aggregated 2PACz by forming an energetically favorable complex with the phosphonic acid groups, yielding an uniform and aggregate‐free SAM layer. Comprehensive characterization confirms that this treatment enhances film quality and surface wettability, thereby improving the HTL/active layer interfacial contact. Integrating this optimized SAM into OPV devices leads to significantly improved efficiency of 15.38% using a blade‐coated 1 cm 2 active area, primarily due to improved charge extraction and reduced trap‐assisted recombination, which enhance both open‐circuit voltage and fill factor. Furthermore, the superior uniformity and reproducibility of NH‐treated HTL facilitates successful large‐area fabrication. As a result, the power conversion efficiency (PCE) of OPV modules are enhanced from 14.07% to 15.02%, and the resulting perovskite‐organic tandem module achieves a PCE of 19.89% at 16.41 cm 2 active area, demonstrating a robust pathway for high‐performance scalable photovoltaics.