Biology subjects

Chen, X. C.

Publications and source records attributed to Chen, X. C..

3 recordsLinked to original sources

bioRxiv2025

Highly Adaptive Conductive Polymer Electronics Enhance Neural Data and Learning Accuracy

Human skin, the bodys largest organ, plays a vital role in sensing and transmitting neuronal, mechanical, and biochemical signals, making it an essential non-invasive interface for health monitoring, rehabilitation, and human-machine interaction. However, aging-related changes, including thinning, increased wrinkling, dryness, and altered collagen structure, significantly impact electrical impedance, conductance, and contact stability, challenging the fidelity and consistency of bioelectronic signal acquisition. Here, we address this gap by developing "AdapSkin," an age-adaptive, skin-mimicking, bio-adhesive, and stretchable polymeric electronic skin interface that seamlessly conforms to diverse skin properties, enabling high-fidelity and high-density electrophysiological recording. The soft electrodes of AdapSkin are composed of an aqueously processed, homogeneously mixed organic nanocomposite with a conductive polymer percolation network, forming a gel-like interface that reduces modulus and enhances skin-electrode contact. The materials platform achieves extraordinary softness and electrical stretchability of up to 1200% through a double-network composite structure. AdapSkin significantly minimizes age-induced variations in interfacial impedance and signal-to-noise ratio (SNR), improving signal consistency for neuromuscular assessment, prosthetic control, and rehabilitation applications. Scalable fabrication enables the creation of large-area electrode arrays, which reduces motion artifacts, improves sEMG mapping reliability, and ensures long-term signal stability across various age groups. Machine learning analysis further demonstrates AdapSkins superior accuracy in gesture classification for elderly users, highlighting its potential to enhance prosthetic control, assistive robotics, and rehabilitation for individuals with sarcopenia and neuromuscular decline. By improving signal quality and adaptability in aging populations, AdapSkin advances fair bioelectronic interfaces, fostering more equitable and effective healthcare technologies for age-related conditions.

bioengineering↗

bioRxiv2024

Identification of a Cluster of Benzene Activation Enzymes in a Strictly Anoxic Methanogenic Consortium

The Oil Refinery (OR) consortium is a model methanogenic enrichment culture used to study anaerobic benzene degradation. Over half of the cultures bacterial community consists of two closely related Desulfobacterota strains, designated ORM2a and ORM2b, whose mechanisms of benzene activation are unknown. Two new metagenomes, including a complete circularized metagenome-assembled genome (MAG) for ORM2a, enabled a thorough investigation of this cultures proteome. Among the proteins identified were Bam-like subunits of an ATP-independent benzoyl-CoA degradation pathway, as well as downstream {beta}-oxidation proteins yielding acetate. The most abundant proteins identified mapped to two ORM2a gene clusters of unknown function. Homologous and syntenic gene clusters were identified in genomes of ORM2b and a sulfate-reducing Pelotomaculum that also degrades benzene, as well as in nine contigs assembled from hydrothermal vent metagenomes. Extensive homology and structural predictions suggest that the first cluster - termed the "Magic" gene cluster - encodes for enzymes catalyzing the chemically challenging activation of benzene and subsequent transformation steps yielding benzoyl-CoA. The second ("Nanopod") gene cluster encodes a transmembrane complex that may facilitate benzene transport across the cell membrane. Phylogenomic analyses place ORM2a and ORM2b within a novel genus of strict anaerobes specialized for benzene degradation, which we propose naming "Candidatus Anaerobenzenivorax". IMPORTANCEBenzene is a widespread, persistent and toxic pollutant that can accumulate in anoxic environments such as groundwater and sediments. Despite decades of study, the biochemical mechanisms by which benzene is activated under anaerobic conditions remain unproven. This study provides strong genetic and proteomic evidence for a new class of enzymes that initiate anaerobic benzene activation and proposes a preliminary model for their underlying biochemistry. These findings lay a foundation for future biochemical studies and expand our understanding of how microbes carry out extreme redox chemistry in the absence of oxygen.

microbiology↗

bioRxiv2022

Transient Oxygen Exposure Causes Profound and Lasting Changes to a Benzene-Degrading Methanogenic Community

We investigated the impact of oxygen on a strictly anaerobic, methanogenic benzene-degrading enrichment culture derived decades ago from oil-contaminated sediment. The culture includes a benzene fermenter from Deltaproteobacteria Candidate clade Sva0485 (referred to as ORM2) and methanogenic archaea. A relatively small one-time injection of air, simulating a small leak into a batch culture bottle, had no measurable impact on benzene degradation rates, although retrospectively, a tiny enrichment of aerobic taxa was detected. A subsequent 100 times larger injection of air stalled methanogenesis and caused drastic perturbation of the microbial community. A benzene-degrading Pseudomonas became highly enriched and consumed benzene and all available oxygen. Anaerobic benzene-degrading ORM2 cell numbers plummeted during this time; re-growth and associated recovery of methanogenic benzene degradation took almost one year. These results highlight the oxygen-sensitivity of this methanogenic culture and confirm that the mechanism for anaerobic biotransformation of benzene is independent of oxygen, fundamentally different from established aerobic pathways, and is carried out by distinct microbial communities. The study further highlights the importance of including microbial decay in characterizing and modelling and mixed microbial communities. SYNOPSISMethanogenic benzene degradation in a highly enriched anaerobic consortium was inhibited for a year after transient exposure to oxygen, causing mass decay of benzene-fermenting bacteria. GRAPHIC FOR ABSTRACT ART O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

microbiology↗