Hokkaido University

Chronic pruritus is common and often difficult to treat. Although several studies have examined how cleansing agents used during bathing relate to pruritus, the effect of washcloth use during bathing, including whether discontinuation is associated with lower itch, remains unclear. We conducted a single-center retrospective observational study of 79 washcloth users with diverse skin diseases to evaluate pruritus before and after washcloth withdrawal without treatment escalation. Pruritus severity was measured using a 0 to 10 Numerical Rating Scale (NRS), and scores were compared within patients. At baseline, the mean NRS score among users was 4.79, with cotton and synthetic-fiber washcloths showing comparable scores. Among those who discontinued washcloth use without treatment escalation, mean NRS scores decreased from 4.89 to 1.90 (p < 0.0001), while those who continued showed no significant change in pruritus scores (from 3.86 to 3.60; p > 0.9999). Our data suggest that discontinuing washcloth use may be associated with lower pruritus scores and could represent a practical, low-cost, and none-invasive measure for pruritus management warranting prospective evaluation.

• Multiscale chain-based FE framework for double-network gel mechanics • Coupled damage and viscoelasticity drive path-dependent anisotropy • Predicts hysteresis, damage localization, and crack initiation • Energy-based formulation captures fracture resistance evolution • Physics-informed framework for designing tough soft materials Double-network (DN) gels exhibit an exceptional combination of stretchability, toughness, and energy dissipation, making them promising materials for soft robotics, biomedical devices, and flexible electronics. These outstanding properties arise from the interplay between a brittle, sacrificial primary network and a ductile, extensible secondary network. However, capturing the complex, anisotropic, and path-dependent mechanical response of DN gels - especially under multiaxial and non-uniform loading - remains a major modeling challenge. This work introduces a three-dimensional multiscale constitutive model that integrates progressive chain scission, anisotropic damage, viscoelastic relaxation, and inter-network interactions. The primary network is modeled as an entropic assembly of chains with stochastic lengths undergoing irreversible damage, upscaled via microsphere integration to capture directionality. The secondary network follows a generalized Maxwell formulation to reproduce rate-dependent dissipation. Energy coupling between the two networks enables the model to reflect microstructural rearrangement, directional softening, and residual anisotropy. The model is implemented as a UMAT in ABAQUS/Standard and validated against experimental data under both homogeneous and non-uniform loading conditions. It accurately captures nonlinear stress-strain behavior, hysteresis, and anisotropic softening resulting from prior deformation. In pre-notched specimens under pure shear, simulations reproduce force-displacement response, stress localization, and damage evolution up to crack initiation. An energy-based analysis highlights the roles of reversible and dissipated energy, with predicted critical energy release rates closely matching experiments across pre-stretch levels. The model offers a predictive, physically grounded framework for understanding and engineering tough, damage-resistant DN gels.

We report the selective nucleophilic addition of aryllithium species to acyl cyanides-electrophiles bearing both carbonyl and cyano functional groups-under catalyst-free continuous flow conditions. Using benzoyl cyanide as a model substrate, we demonstrate that the flow microreactor system enables highly selective addition to the carbonyl moiety while eliminating the cyano group as a leaving group, affording polyfunctional ketones in significantly improved yields compared to traditional batch processes.

Despite the growing concern over per- and polyfluoroalkyl substances (PFAS) exposure in companion animals, dietary intake through commercial pet food remains poorly characterized. In this study, we conducted a comprehensive analysis of 100 commercially available pet food products for dogs and cats in Japan, encompassing both dry and wet types, to quantify 34 target PFAS compounds. PFAS were frequently detected, with concentrations varying by food type, ingredients, and country of origin. Fish-based products contained elevated levels of perfluorooctanesulfonic acid (PFOS), perfluoroundecanoic acid (PFUnDA), and perfluorotridecanoic acid (PFTrDA), and regional patterns suggested the influence of Asian-specific PFAS sources such as F-53B. Hazard quotient (HQ) assessments based on EFSA tolerable weekly intakes indicated that average HQs exceeded 1 for both dogs and cats in several products, signaling potential health risks. However, due to the lack of species-specific toxicokinetic information for dogs and cats, the EFSA-based risk characterization presented here should be interpreted as a preliminary assessment. Although dry food had higher PFAS concentrations when converted to feeding amounts, estimated exposure was higher for wet food due to higher consumption. These findings provide the first evidence of ingredient-driven and country-of-origin-dependent PFAS contamination in pet food. Fish used as ingredients are a significant source of exposure to PFAS. They also highlight the urgent need for regulatory oversight and toxicological evaluations specific to companion animals. These animals serve as vulnerable populations and as sentinels of human co-exposure in domestic environments.