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Organic electrochemical transistors (OECTs) are ideal devices for translating biological signals into electrical readouts and have applications in bioelectronics, biosensing, and neuromorphic computing. Despite their potential, developing programmable and modular methods for living systems to interface with OECTs has proven challenging. Here we describe hybrid OECTs containing the model electroactive bacteriumShewanella oneidensisthat enable the transduction of biological computations to electrical responses. Specifically, we fabricated planar p-type OECTs and demonstrated that channel de-doping is driven by extracellular electron transfer (EET) fromS. oneidensis. Leveraging this mechanistic understanding and our ability to control EET flux via transcriptional regulation, we used plasmid-based Boolean logic gates to translate biological computation into current changes within the OECT. Finally, we demonstrated EET-driven changes to OECT synaptic plasticity. This work enables fundamental EET studies and OECT-based biosensing and biocomputing systems with genetically controllable and modular design elements.

 

Tensor contractions are ubiquitous in computational chemistry andphysics, where tensors generally represent states or operators andcontractions express the algebra of these quantities. In this context,the states and operators often preserve physical conservation laws,which are manifested as group symmetries in the tensors. These groupsymmetries imply that each tensor has block sparsity and can be storedin a reduced form. For nontrivial contractions, the memory footprint andcost are lowered, respectively, by a linear and a quadratic factor inthe number of symmetry sectors. State-of-the-art tensor contractionsoftware libraries exploit this opportunity by iterating over blocks orusing general block-sparse tensor representations. Both approachesentail overhead in performance and code complexity. With intuition aidedby tensor diagrams, we present a technique, irreducible representationalignment, which enables efficient handling of Abelian group symmetriesvia only dense tensors, by using contraction-specific reduced forms.This technique yields a general algorithm for arbitrary group symmetriccontractions, which we implement in Python and apply to a variety ofrepresentative contractions from quantum chemistry and tensor networkmethods. As a consequence of relying on only dense tensor contractions,we can easily make use of efficient batched matrix multiplication viaIntel’s MKL and distributed tensor contraction via the Cyclops library,achieving good efficiency and parallel scalability on up to 4096 KnightsLanding cores of a supercomputer.

 

Traditional hydrophilic wound dressings, while common, fail to effectively drain wound exudate, creating conditions favorable for bacterial growth. Similarly, newer Janus‐type dressings with hydrophobic‐hydrophilic properties also fall short, as their hydrophobic side causes excessive dryness by pulling biofluids from the wound, disrupting moisture balance. Additionally, embedding antibiotics in dressings at fixed concentrations, regardless of the infection type, reduces effectiveness and contributes to the growing problem of antibiotic resistance. In response, a single‐layered Janus paper wound dressing, designed for efficient exudate absorption and precise antibiotic delivery, is developed. The approach differs from traditional Janus‐type dressings; a hydrophilic layer is placed directly against the wound for better moisture management, while antibiotics are applied through the hydrophobic layer. To further enhance exudate management, the hydrophilic section with four extra absorbent pads is extended. The dressing's antibiotic efficacy and dosage are tailored based on antibiotic susceptibility testing, ensuring targeted treatment. The selected antibiotic is manually added but automatically delivered directly to the wound bed. The in vitro and ex vivo evaluations, using bacterial cultures on agar and porcine skin assays, respectively, confirm the dressing's superior exudate drainage and its ability to inhibit pathogen growth and reproduction, marking a significant advancement in wound care.

 

Nitrogen dioxide (NO₂) and formaldehyde (HCHO) play vital roles in atmospheric photochemical processes. Their tropospheric vertical column density (TVCD) distributions have been monitored by satellite instruments. Evaluation of these observations is essential for applying these observations to study photochemistry. Assessing satellite products using observations at rural sites, where local emissions are minimal, is particularly useful due in part to the spatial homogeneity of trace gases. In this study, we evaluate OMI and TROPOMI NO₂and HCHO TVCDs using multi‐axis differential optical absorption spectroscopy (MAX‐DOAS) measurements at a rural site in the east coast of the Shandong province, China in spring 2018 during the Ozone Photochemistry and Export from China Experiment (OPECE) measurement campaign. On days not affected by local burning, we found generally good agreement of NO₂data after using consistent a priori profiles in satellite and MAX‐DOAS retrievals and accounting for low biases in scattering weights in one of the OMI products. In comparison, satellite HCHO products exhibited weaker correlations with MAX‐DOAS data, in contrast to satellite NO₂products. However, TROPOMI HCHO products showed significantly better agreement with MAX‐DOAS measurements compared to OMI data. Furthermore, case studies of the vertical profiles measured by MAX‐DOAS on burning days revealed large enhancements of nitrous acid (HONO), NO₂, and HCHO in the upper boundary layer, accompanied with considerable variability, particularly in HONO enhancements.

 

We demonstrate the first example of a wearable self-charging power system that offers (i) the high-energy harvesting function of a microbial fuel cell (MFC) and (ii) the high-power operation of a supercapacitor through charging and discharging. The MFC uses human skin bacteria as a biocatalyst to transform the chemical energy of human sweat into electrical power through bacterial metabolism, while the integrated supercapacitor stores the generated electricity for constant and high-pulse power generation even with the irregular perspiration of individuals. The all-printed paper-based power system integrates the horizontally structured MFC and the planar supercapacitor, representing the most favorable platform for wearable applications because of its lightweight and easy integrability into other wearable devices. The self-charging wearable system attains higher electrical power and longer-term operational capability, demonstrating considerable potential as a power source for wearable electronics.