Browse Articles
Discover research articles across all indexed journals
Impacts of climate change on the suitable habitat of Angelica sinensis and analysis of its drivers in China
Correction for Austin et al., Death-receptor activation halts clathrin-dependent endocytosis
Description of current status of implementation and management of cardiac arrest in China
Publisher Correction: Optimization and prediction of paver block properties with ceramic waste as fine aggregate using response surface methodology
Superpixel guided spectral-spatial feature extraction and weighted feature fusion for hyperspectral image classification with limited training samples
Daily briefing: The infinite optimism of polymath Gottfried Leibniz
The link between sleep bruxism and oxidative stress based on a polysomnographic study
Publisher Correction: Rethinking the four-wing problem in plesiosaur swimming using bio-inspired decentralized control
Correction for Khadim et al., Continental freshwater discharge influences sea surface salinity variability near world’s megadeltas
In-pixel foreground and contrast enhancement circuits with customizable mapping
Abstract This paper presents an in-pixel contrast enhancement circuit that performs image processing directly within the pixel circuit. The circuit leverages HyperFET, a hybrid device combining a MOSFET and a phase transition material (PTM), to enhance performance. It can be tuned for different modes of operation. In foreground enhancement mode, it suppresses low-intensity background pixels to nearly zero, isolating the foreground for better object visibility. In contrast enhancement mode, it improves overall image contrast. The contrast enhancement function is customizable both during the design phase and in real-time, allowing the circuit to adapt to specific applications and varying lighting conditions. A model of the designed pixel circuit is developed and applied to a full pixel array, demonstrating significant improvements in image quality. Simulations performed in HSPICE show a nearly 6x increase in Michelson Contrast Ratio (CR) in the foreground enhancement mode. Furthermore, process variation and Signal-to-Noise Ratio (SNR) analysis has been conducted to evaluate the robustness of the design under manufacturing variations. The simulation results indicate its potential for real-time, adaptive contrast enhancement across various imaging environments.
SARS-CoV-2 S-protein expression drives syncytia formation in endothelial cells
Correction for Thompson and Fronhofer, The conflict between adaptation and dispersal for maintaining biodiversity in changing environments
Nectar-robbing bees commit floral larceny
Correction to Supporting Information for Sutter et al., Electrochemical cofactor recycling of bacterial microcompartments
Our remote fieldwork taught us how to band together as scientists
Correction for Zioga et al., Observed carbon decoupling of subnational production insufficient for net-zero goal by 2050
Chaos erupts in US science as Trump’s team declares freeze on federal grants
Coupling Cu2O clusters and imine-linked COFs on microfiltration membranes for fast and robust water sterilization
Convergent evolution of oxidized sugar metabolism in commensal and pathogenic microbes in the inflamed gut
Abstract Inflammation-associated perturbations of the gut microbiome are well characterized, but poorly understood. Here, we demonstrate that disparate taxa recapitulate the metabolism of the oxidized sugars glucarate and galactarate, utilizing enzymatically divergent, yet functionally equivalent, gud/gar pathways. The divergent pathway in commensals includes a putative 5-KDG aldolase (GudL) and an uncharacterized ABC transporter (GarABC) that recapitulate the function of their non-homologous counterparts in pathogens. A systematic bioinformatic search for the gud/gar pathway in gut microbes identified 887 species putatively capable of metabolizing oxidized sugars. Previous studies showed that inflammation-derived nitrate, formed by nitric oxide reacting with superoxide, promotes pathogen growth. Our findings reveal a parallel phenomenon: oxidized sugars, also produced from reactions with nitric oxide, serve as alternative carbon sources for commensal microbes. Previously considered a pathogen virulence factor, oxidized sugar metabolism is also present in specific commensals and may contribute to their increased relative abundance in gastrointestinal inflammation.
3D N-heterocyclic covalent organic frameworks for urea photosynthesis from NH3 and CO2
Abstract Artificial photosynthesis of urea from NH3 and CO2 seems to remain still essentially unexplored. Herein, three isomorphic three-dimensional covalent organic frameworks with twofold interpenetrated ffc topology are functionalized by benzene, pyrazine, and tetrazine active moieties, respectively. A series of experiment results disclose the gradually enhanced conductivity, light-harvesting capacity, photogenerated carrier separation efficiency, and co-adsorption capacity towards NH3 and CO2 in the order of benzene-, pyrazine-, and tetrazine-containing framework. This in turn endows tetrazine-containing framework with superior photocatalytic activity towards urea production from NH3 and CO2 with the yield of 523 μmol g−1 h−1, 40 and 4 times higher than that for benzene- and pyrazine-containing framework, respectively, indicating the heterocyclic N microenvironment-dependent catalytic performance for these three photocatalysts. This is further confirmed by in-situ spectroscopic characterization and density functional theory calculations. This work lays a way towards sustainable photosynthesis of urea.