Cu- and P-co-doped nitrogen-doped hierarchical carbon for enhanced oxygen reduction reaction in zinc-air batteries.

High-performance Fe-based nitrogen-doped carbon oxygen reduction catalysts have been widely reported, but the Fenton reaction faced by such catalysts has hindered their practical application in fuel cells. The development of inexpensive, effective, and durable non-Fe nitrogen-doped carbon electrocatalysts is important for advancing fuel cell technology. In this work, we have introduced a molecular coordination chemistry method to synthesize a Cu- and P-co-doped nitrogen-doped hierarchical carbon (Cu-P-N-C) oxygen reduction reaction (ORR) electrocatalyst by pyrolyzing a mixture of phytate and melamine.

Oxygen-Coordinated Cr Single-Atom Catalyst for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells.

Carbon-supported metal single-atom catalysts (M-SACs) are promising oxygen reduction reaction (ORR) catalysts. Their ORR activity and selectivity are significantly affected by the heteroatoms that coordinate the central metal atoms. Previous reports found that oxygen-coordinated M-SACs promoted a 2e ORR rather than the 4e ORR that is more desirable for fuel cells.

A bipartite bacterial virulence factor targets the complement system and neutrophil activation.

The complement system and neutrophils constitute the two main pillars of the host innate immune defense against infection by bacterial pathogens. Here, we identify T-Mac, a novel virulence factor of the periodontal pathogen Treponema denticola that allows bacteria to evade both defense systems. We show that T-Mac is expressed as a pre-protein that is cleaved into two functional units.

Common regulatory mutation increases single-cell survival to antibiotic exposures in .

Typical antibiotic susceptibility testing (AST) of microbial samples is performed in homogeneous cultures in steady environments, which does not account for the highly heterogeneous and dynamic nature of antibiotic responses. The most common mutation found in lineages evolved in the human lung, a loss of function of repressor MexZ, increases basal levels of multidrug efflux MexXY, but does not increase resistance by traditional MIC measures. Here, we use single cell microfluidics to show that response to aminoglycosides is highly heterogeneous, with only a subpopulation of cells surviving exposure.

Drug Cocktail Formulation via Circuit Design.

Electronic circuits intuitively visualize and quantitatively simulate biological systems with nonlinear differential equations that exhibit complicated dynamics. Drug cocktail therapies are a powerful tool against diseases that exhibit such dynamics. We show that just six key states, which are represented in a feedback circuit, enable drug-cocktail formulation: 1) healthy cell number; 2) infected cell number; 3) extracellular pathogen number; 4) intracellular pathogenic molecule number; 5) innate immune system strength; and 6) adaptive immune system strength.

Efficient Binary Weight Convolutional Network Accelerator for Speech Recognition.

Speech recognition has progressed tremendously in the area of artificial intelligence (AI). However, the performance of the real-time offline Chinese speech recognition neural network accelerator for edge AI needs to be improved. This paper proposes a configurable convolutional neural network accelerator based on a lightweight speech recognition model, which can dramatically reduce hardware resource consumption while guaranteeing an acceptable error rate.

Zinc- Fe/FeC/FeS@Fe-N-C active sites grown on N-doped porous carbon toward efficient oxygen reduction reaction in zinc-air batteries.

The development of efficient non-precious metal oxygen reduction reaction catalysts to replace Pt-based catalysts is of great significance to accelerate the commercial application of fuel cells. In this study, a hierarchical porous carbon oxygen reduction reaction catalyst with Fe/FeC/FeS@Fe-N-C active sites was developed a simple and efficient solid-phase synthesis method. The introduction of zinc inhibited the growth and agglomeration of the nanoparticles and induced the formation of active nitrogen species and porosity, thus boosting the catalytic activity.

Rapid modeling of experimental molecular kinetics with simple electronic circuits instead of with complex differential equations.

Kinetic modeling has relied on using a tedious number of mathematical equations to describe molecular kinetics in interacting reactions. The long list of differential equations with associated abstract variables and parameters inevitably hinders readers' easy understanding of the models. However, the mathematical equations describing the kinetics of biochemical reactions can be exactly mapped to the dynamics of voltages and currents in simple electronic circuits wherein voltages represent molecular concentrations and currents represent molecular fluxes.

Movable type printing method to synthesize high-entropy single-atom catalysts.

The controllable anchoring of multiple isolated metal atoms into a single support exhibits scientific and technological opportunities, while the synthesis of catalysts with multiple single metal atoms remains a challenge and has been rarely reported. Herein, we present a general route for anchoring up to eleven metals as highly dispersed single-atom centers on porous nitride-doped carbon supports with the developed movable type printing method, and label them as high-entropy single-atom catalysts. Various high-entropy single-atom catalysts with tunable multicomponent are successfully synthesized with the same method by adjusting only the printing templates and carbonization parameters.

Bee Venom Induces Acute Inflammation through a HO-Mediated System That Utilizes Superoxide Dismutase.

Venoms from venomous arthropods, including bees, typically induce an immediate local inflammatory response; however, how venoms acutely elicit inflammatory response and which components induce an inflammatory response remain unknown. Moreover, the presence of superoxide dismutase (SOD3) in venom and its functional link to the acute inflammatory response has not been determined to date. Here, we confirmed that SOD3 in bee venom (bvSOD3) acts as an inducer of HO production to promote acute inflammatory responses.

Sorption of Cellulases in Biofilm Enhances Cellulose Degradation by .

Biofilm commonly forms on the surfaces of cellulosic biomass but its roles in cellulose degradation remain largely unexplored. We used to study possible mechanisms and the contributions of two major biofilm components, extracellular polysaccharides (EPS) and TasA protein, to submerged biofilm formation on cellulose and its degradation. We found that biofilm produced by is able to absorb exogenous cellulase added to the culture medium and also retain self-produced cellulase within the biofilm matrix.

Cytomorphic Electronic Systems: A review and perspective.

Boltzmann-exponential thermodynamic laws govern noisy molecular flux in chemical reactions as well as noisy subthreshold electron current flux in transistors. These common mathematical laws enable one to map and simulate arbitrary stochastic biochemical reaction networks in highly efficient systems built on subthreshold analog circuits. Such simulations can accurately model noisy, nonlinear, asynchronous, stiff, and non-modular feedback dynamics in interconnected networks in the physical circuits, automatically.

Early Warning Value of ASL-MRI to Estimate Premorbid Variations in Patients With Early Postoperative Cognitive Dysfunctions.

: Postoperative cognitive dysfunction (POCD) is a general complication following cardiac and major non-cardiac surgery amongst the elderly, yet its causes and mechanisms are still unknown. The present study aimed to detect whether regional cerebral blood flow (CBF) is altered in the brain before surgery in POCD patients compared with non-POCD (NPOCD) patients, thus, CBF variation may potentially predict the occurrence of early POCD. : Fifty patients scheduled for spinal stenosis surgery were enrolled in the study.

Measuring and modeling energy and power consumption in living microbial cells with a synthetic ATP reporter.

Background: Adenosine triphosphate (ATP) is the main energy carrier in living organisms, critical for metabolism and essential physiological processes. In humans, abnormal regulation of energy levels (ATP concentration) and power consumption (ATP consumption flux) in cells is associated with numerous diseases from cancer, to viral infection and immune dysfunction, while in microbes it influences their responses to drugs and other stresses. The measurement and modeling of ATP dynamics in cells is therefore a critical component in understanding fundamental physiology and its role in pathology.

Lipolytic Activity of a Carboxylesterase from Bumblebee () Venom.

Bee venom is a complex mixture composed of peptides, proteins with enzymatic properties, and low-molecular-weight compounds. Although the carboxylesterase in bee venom has been identified as an allergen, the enzyme's role as a venom component has not been previously elucidated. Here, we show the lipolytic activity of a bumblebee () venom carboxylesterase (BivCaE).

Prevalence of phase variable epigenetic invertons among host-associated bacteria.

Type I restriction-modification (R-M) systems consist of a DNA endonuclease (HsdR, HsdM and HsdS subunits) and methyltransferase (HsdM and HsdS subunits). The hsdS sequences flanked by inverted repeats (referred to as epigenetic invertons) in certain Type I R-M systems undergo invertase-catalyzed inversions. Previous studies in Streptococcus pneumoniae have shown that hsdS inversions within clonal populations produce subpopulations with profound differences in the methylome, cellular physiology and virulence.

Engineering the electronic and strained interface for high activity of PdM@Pt electrocatalysts for oxygen reduction reaction.

Alloyed nanoparticles with core-shell structures provide a favorable model to modulate interfacial interaction and surface structures at the atomic level, which is important for designing electrocatalysts with high activity and durability. Herein, core-shell structured PdM@Pt/C nanoparticles with binary PdM alloy cores (M = Fe, Ni, and Co) and a monolayer Pt shell were successfully synthesized with diverse interfaces. Among these, PdFe@Pt/C exhibited the best oxygen reduction reaction catalytic performance, roughly 5.

Coupling hollow FeO nanoparticles with oxygen vacancy on mesoporous carbon as a high-efficiency ORR electrocatalyst for Zn-air battery.

Designing a low-cost, high-efficiency and robust doped-carbon-based oxygen reduction reaction electrocatalyst for large-scale implementations of fuel cells is highly desirable but challenging. In this work, we report a new type of hollow FeO with oxygen vacancy incorporating on mesoporous carbon prepared by pyrolyzing mesoporous carbon enriched with oxygen-containing functional groups, in combination with ferric acetylacetonate. The catalysts possess high specific surface area with predominantly mesoporous architecture and ultrahigh nitrogen content (up to 7.

A di-iron protein recruited as an Fe[II] and oxygen sensor for bacterial chemotaxis functions by stabilizing an iron-peroxy species.

Many bacteria contain cytoplasmic chemoreceptors that lack sensor domains. Here, we demonstrate that such cytoplasmic receptors found in 8 different bacterial and archaeal phyla genetically couple to metalloproteins related to β-lactamases and nitric oxide reductases. We show that this oxygen-binding di-iron protein (ODP) acts as a sensor for chemotactic responses to both iron and oxygen in the human pathogen ().

A Novel Bioelectronic Reporter System in Living Cells Tested with a Synthetic Biological Comparator.

As the fields of biotechnology and synthetic biology expand, cheap and sensitive tools are needed to measure increasingly complicated genetic circuits. In order to bypass some drawbacks of optical fluorescent reporting systems, we have designed and created a co-culture microbial fuel cell (MFC) system for electronic reporting. This system leverages the syntrophic growth of Escheriachia.

UIO-66-NH -Derived Mesoporous Carbon Catalyst Co-Doped with Fe/N/S as Highly Efficient Cathode Catalyst for PEMFCs.

Efficient, low-cost catalysts are desirable for the sluggish oxygen reduction reaction (ORR). Herein, UIO-66-NH -derived multi-element (Fe, S, N) co-doped porous carbon catalyst is reported, Fe/N/S-PC, with an octahedral morphology, a well-defined mesoporous structure, and highly dispersed doping elements, synthesized by a double-solvent diffusion-pyrolysis method (DSDPM). The morphology of the UIO-66-NH precursor is perfectly inherited by the derived carbon material, resulting in a high surface area, a well-defined mesoporous structure, and atomic-level dispersion of the doping elements.

From Chlorella to Nestlike Framework Constructed with Doped Carbon Nanotubes: A Biomass-Derived, High-Performance, Bifunctional Oxygen Reduction/Evolution Catalyst.

The development of effective bifunctional catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is significant for energy conversion systems, such as Li-air batteries, fuel cells, and water splitting technologies. Herein, a Chlorella-derived catalyst with a nestlike framework, composed of bamboolike nanotubes that encapsulate cobalt nanoparticles, has been prepared through a facile pyrolysis process. It achieves perfect bifunctional catalysis both in ORR and OER on a single catalyst.

Well-Defined ZIF-Derived Fe-N Codoped Carbon Nanoframes as Efficient Oxygen Reduction Catalysts.

A series of ZIF-derived Fe-N codoped carbon materials with a well-defined morphology, high surface area, tunable sizes and porous nanoframe structure was successfully prepared by synthesizing Fe-doped ZIF-8 through the assembly of Zn ions with 2-methylimidazole in the presence of iron(III) acetylacetonate, followed by pyrolysis at a high temperature and in an Ar atmosphere. The prepared optimum catalyst materials exhibited excellent activity for the oxygen reduction reaction (ORR) and outstanding durability in both acidic and alkaline solutions. We found that Fe doping during the ZIF-8 synthesis stage was crucial to achieve the materials' well-defined morphology, tunable size, good particle dispersion, and high performance.

Complex carbohydrates reduce the frequency of antagonistic interactions among bacteria degrading cellulose and xylan.

Bacterial competition for resources is common in nature but positive interactions among bacteria are also evident. We speculate that the structural complexity of substrate might play a role in mediating bacterial interactions. We tested the hypothesis that the frequency of antagonistic interactions among lignocellulolytic bacteria is reduced when complex polysaccharide is the main carbon source compared to when a simple sugar such as glucose is available.

Lyme disease spirochaete Borrelia burgdorferi does not require thiamin.

Thiamin pyrophosphate (ThDP), the active form of thiamin (vitamin B), is believed to be an essential cofactor for all living organisms. Here, we report the unprecedented result that thiamin is dispensable for the growth of the Lyme disease pathogen Borrelia burgdorferi (Bb). Bb lacks genes for thiamin biosynthesis and transport as well as known ThDP-dependent enzymes, and we were unable to detect thiamin or its derivatives in Bb cells.