Cell Reports Physical Science最新文献

Tracking genomic sequences as microbial biomarkers in wastewater has been used to determine community prevalence of infectious diseases, contributing to public health surveillance programs worldwide. Here, we report upon a low-cost, rapid, and user-friendly paper microfluidic platform for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza detection, using loop-mediated isothermal amplification, with signal read using a mobile phone camera. Sample-to-answer results were collected in less than 1.5 h, providing rapid multiplexed detection of viruses in wastewater, with a detection limit of <20 copies mL⁻¹. The device was subsequently used for on-site testing of SARS-CoV-2 in wastewater samples from four quarantine hotels at London Heathrow Airport, showing comparable results to those obtained using polymerase chain reaction. This sensing platform, which enables rapid and localized testing without requiring samples to be sent to centralized laboratories, provides a potentially important public health tool for pandemic preparedness, with a variety of future wastewater surveillance applications in community settings.

A common failure mode for solid-state lithium-metal batteries is solid-electrolyte fracture during lithium plating, but fracture initiation is complicated to diagnose. Here, an electrochemically and mechanically coupled steady-state lithium-plating model is implemented numerically to study fracture initiation at the lithium/solid-electrolyte interface. The solid electrolyte is treated as a linear elastic solid, while lithium is modeled as a Newtonian fluid. An electrochemical connection between the two phases is made via the stress-modified Butler-Volmer equation at the Gaussian-curved interface, where lithium protrudes into the solid electrolyte. The model simulations demonstrate that the couplings result in significantly different electrochemical and mechanical behaviors from those predicted by the model without the couplings. The J-integrals—an indicator of fracture—of the coupled and uncoupled models are six orders of magnitude apart. The coupled model supports a shear-traction-driven fracture concentrated at the asperity base instead of the commonly attributed pressure-driven fracture at the asperity tip. Finally, our sensitivity analysis reveals that lithium pseudo-viscosity and asperity geometry are important parameters determining fracture initiation.

Doping is a key strategy for enhancing the charge mobility and thermoelectric properties of polymers. While advancements utilizing the anion exchange technique have notably enhanced doping efficiency, there is a need for further optimization of the doping process. This study introduces a two-step doping approach combining solid-state diffusion with anion exchange, applied to poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene] (PBTTTC14) films. Initial 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (F4TCNQ) diffusion doping followed by anion exchange with F4TCNQ/ionic liquid achieved higher conductivity than one-step anion exchange doping. Spectral and structural analyses elucidated the enhanced doping mechanism. Additionally, adjusting the molecular weight (MW) of PBTTTC14 from 11,867 to 175,199 improved doping levels and conductivity, reaching 1,103.8 S cm⁻¹. A medium MW (MW = 99,407) optimized thermoelectric performance by balancing conductivity and Seebeck coefficients. These findings provide insights into controlling doping and performance of conductive semiconductor polymers through a two-step doping process and MW engineering.

Electromagnetic wave absorbers (EWAs) exert considerable influence in the information age, and polarization relaxation has been vital to regulating the electromagnetic response toward high-performance EWAs. However, polarization relaxation still confronts several hurdles in understanding the intrinsic mechanisms and modulating the performance. In view of this, we first introduce the main dielectric polarizations including dipole polarization, interface polarization, and defect-induced polarization. The concepts of corresponding polarization relaxations and their correlations are then clarified, and the influencing factors of polarization relaxations in EWAs are elucidated. Subsequently, we detail the tailoring strategies of dielectric polarization from the perspectives of components modulation and structure regulation, together with state-of-the-art achievements. Finally, the challenges and future exploration directions for dielectric EWAs are proposed.

Collagen fibrils are the building blocks of many tissues from fish scales and tendons to bone. Synchrotron small-angle X-ray scattering (SAXS) with in situ mechanical testing is a powerful tool to investigate collagen fibril deformation. There is a need to combine data from SAXS studies to investigate structure-function relationships. A literature search used the concepts of mechanical properties, collagen, and SAXS, with 52 articles meeting the eligibility criteria. Here, we report that mineralized tissues transfer a greater proportion of tissue-scale deformation to the fibril: 67% for cortical bone, 49% for tendon, 10% for ligament, and 3% for skin. Across non-mineralized tissues, tissues with less complexity and greater elastin content transfer less deformation to the fibril. The meta-analysis finds 20%–40% lower fibril strain in human aging and disease compared to controls, which contributes toward fracture risk. This synthesis demonstrates how variations in composition and structure tune material properties in collagen-based tissues.

The surge in plastic waste has become one of the most pressing environmental challenges of our time. Traditional methods of plastic disposal, such as landfilling and incineration, pose significant environmental hazards, whereas mechanical recycling processes often yield downgraded materials with limited applications. Recent advancements in catalytic science have led to the development of innovative catalytic systems enabling the efficient deconstruction and upcycling of plastic polymers. In this Voices article, we ask a panel of experts worldwide: how can catalysis address this plastic crisis?

Tryptophan and its metabolites, produced by the gut microbiota, are pivotal for human physiological and mental health. Yet, quantifying these structurally similar compounds with high specificity remains a challenge, hindering point-of-care diagnostics and targeted therapeutic interventions. Leveraging the innate specificity and adaptability of biological systems, we present a biosensing approach capable of identifying specific metabolites in complex contexts with minimal cross-activity. This study introduces a generalizable strategy that combines evolutionary analysis, key ligand-binding residue identification, and mutagenesis scanning to pinpoint ligand-specific transcription factor variants. Furthermore, we uncover regulatory mechanisms within uncharacterized ligand-binding domains, whether in homodimer interfaces or monomers, through structural prediction and ligand docking. Notably, our “plug-and-play” strategy broadens the detection spectrum, enabling the exclusive biosensing of indole-3-acetic acid (an auxin), tryptamine, indole-3-pyruvic acid, and other tryptophan derivatives in engineered probiotics. This groundwork paves the way to create highly specific transcriptional biosensors for potential clinical, agricultural, and industrial use.

Designing a soft manipulator that effectively serves human applications presents significant challenges, especially in motion robustness and accuracy. The elephant trunk, with its flexibility, strong load-bearing capacity, and dexterous yet soft tip, provides an inspiring model. Inspired by the elephant trunk’s thrust-deformation mechanism under multi-muscle action, we present the design principles of a composite tendon and pneumatic hybrid-driven tapered soft manipulator (TSM). Simulation and testing show that the TSM achieves a repeatability accuracy of 0.69 $\pm$$\pm$ 0.43 mm and single-axis errors below 2 mm. With a 2-kg load, it maintains less than 37 mm of deformation in all poses. Additionally, the TSM reduces contact pressure by 35.7% through active softening. These results highlight the manipulator’s strengths in motion stability, load-bearing capacity, and safety during human contact, showcasing its potential as a flexible limb for mobile or humanoid robots.