The CO2 fixation mechanism by Alcaligenes faecalis ZS-1 in a biocathode microbial fuel cell (MFC) was investigated. The closed-circuit MFC (CM) exhibited a significantly higher CO2 fixation rate (10.7%) compared to the open-circuit MFC (OC) (2.0%), indicating that bioelectricity enhances CO2 capture efficiency. During the inward extracellular electron transfer (EET) process, riboflavin concentration increased in the supernatant while cytochrome levels decreased. Genome sequencing revealed diverse metabolic pathways for CO2 fixation in strain ZS-1, with potential dominance of rTCA and C4 pathways under electrotrophic conditions as evidenced by significant upregulation of the ppc gene. Differential metabolite analysis using LC-MS demonstrated that CM promoted upregulation of various lipid metabolites. These findings collectively highlight that ZS-1 simultaneously generated electricity and fixed CO2 and that the ppc associated with bioelectricity played a critical role in CO2 capture. In conclusion, bioelectricity resulted in a significant enhancement in the efficiency of CO2 fixation and lipid production.

Electrolysis of seawater is a promising approach to address freshwater scarcity and indirectly mitigate the energy crisis. In this context, the oxygen evolution reaction (OER) plays a crucial role as one of the half -reactions in water electrolysis. However, the development of cost-effective non -precious metal catalysts for OER remains a challenging issue. In this study, we present a facile method for synthesizing Prussian blue sulfides supported on nickel foam (NF) at ambient temperature. The resulting S-FeNi@NF catalyst demonstrates remarkable electrocatalytic performance with an overpotential of only 330 mV at a current density of 100 mA cm -2 in simulated seawater. Notably, the catalyst exhibits excellent corrosion resistance and electrochemical stability, maintaining its effectiveness for over 120 h following vulcanization. Furthermore, we assessed the catalysts for their resistance to chloride ion corrosion in natural seawater and observed no significant signs of etching for more than 30 days. This outstanding stability of the S-FeNi@NF material can be attributed to its dual protective mechanisms against chloride ions, which encompass both corrosion resistance and the repulsion of chloride ions during electrochemical processes. Our findings offer a fresh perspective on catalyst design, particularly in the context of shielding against chloride -induced degradation in direct seawater electrolysis.

Polymeric heart valves (PHVs) present a promising alternative for treating valvular heart diseases with satisfactory hydrodynamics and durability against structural degeneration. However, the cascaded coagulation, inflammatory responses, and calcification in the dynamic blood environment pose significant challenges to the surface design of current PHVs. In this study, we employed a surface-initiated polymerization method to modify polystyrene-block-isobutylene-block-styrene (SIBS) by creating three hydrogel coatings: poly(2-methacryloyloxy ethyl phosphorylcholine) (pMPC), poly(2-acrylamido-2-methylpropanesulfonic acid) (pAMPS), and poly(2-hydroxyethyl methacrylate) (pHEMA). These hydrogel coatings dramatically promoted SIBS's hydrophilicity and blood compatibility at the initial state. Notably, the pMPC and pAMPS coatings maintained a considerable platelet resistance performance after 12 h of sonication and 10 000 cycles of stretching and bending. However, the sonication process induced visible damage to the pHEMA coating and attenuated the anti-coagulation property. Furthermore, the in vivo subcutaneous implantation studies demonstrated that the amphiphilic pMPC coating showed superior anti-inflammatory and anti-calcification properties. Considering the remarkable stability and optimal biocompatibility, the amphiphilic pMPC coating constructed by surface-initiated polymerization holds promising potential for modifying PHVs. Three surface-initiated hydrogel coatings (pMPC, pAMPS, pHEMA) are constructed on polymeric heart valves. The zwitterionic pMPC coating displays optimal performances, including durable anti-coagulation, anti-inflammation, and anti-calcification.

The sprayable hydrogel coatings that can establish robust adhesion onto diverse materials and devices hold enormous potential; however, a significant challenge persists due to monomer hydration, which impedes even coverage during spraying and induces inadequate adhesion post-gelation. Herein, a polycation-reinforced (PCR) surface bridging strategy is presented to achieve tough and sprayable hydrogel coatings onto diverse materials. The polycations offer superior wettability and instant electrostatic interactions with plasma-treated substrates, facilitating an effective spraying application. This PCR-based hydrogel coatings demonstrate tough adhesion performance to inert PTFE and silicone, including remarkable shear strength (161 ± 49 kPa for PTFE), interfacial toughness (198 ± 27 J m-2 for PTFE), and notable tolerance to cyclic tension (10 000 cycles, 200% strain, silicone). Meanwhile, this method can be applied to various hydrogel formulations, offering diverse functionalities, including underwater adhesion, lubrication, and drug delivery. Furthermore, the PCR concept enables the conformal construction of durable hydrogel coatings onto sophisticated medical devices like cardiovascular stents. Given its simplicity and adaptability, this approach paves an avenue for incorporating hydrogels onto solid surfaces and potentially promotes untapped applications.

The stable adhesion of hydrogel-based bioadhesives with tissue-matchable mechanical properties in biological environments remains a significant challenge. In this work, we propose a polyethyleneimine-polyacrylic acid (PEI-PAA, PEA) double-network polyelectrolyte hydrogel with swelling resistant capacity and tunable mechanical properties via one-step UV-initiated polymerization. Driven by electrostatic interactions and polymer-chain entanglement, this PEA hydrogel displays a distinctive microphase separation behavior, which facilitates a wide tunability in mechanical properties. Specifically, the modulus varies from 0.4 MPa to 106 MPa, and the toughness ranges from 1479 kJ/m3 to 7641 kJ/m3, respectively. Besides, the microphase separation endows PEA hydrogel with notable anti-swelling properties in saline, TBS buffer, and blood, leading to consistent adhesion to diverse moist tissues. We further demonstrate that our PEA hydrogels provide matchable mechanical properties and long-lasting adhesion to rat skin and arteries, which promote skin injury healing and effectively halt artery rupture bleeding in vivo. This work presents a straightforward method to generate non-swelling hydrogels and offers novel insight into the development of bioadhesives to meet diverse mechanical requirements.

Astringency is a common issue in squid processing and consumption. Various techniques such as soaking in salt water, adding acids, and using enzymes have been used to eliminate astringency. However, these methods have their limitations, and the search for a better solution is ongoing. In recent years, ultrasound technology has been proposed as an effective method for removing astringency in squid. This study used four proteins, including lysozyme, bovine serum albumin, collagen, and whey protein, to simulate saliva in the human oral cavity. This study aimed to determine the removal effect of squid astringency after saliva soaking and ultrasound treatment. Physicochemical indicators such as polyphenols and flavonoids, antioxidant activity, relative polymerization degree, and solution zeta potential were used as physicochemical indicators. Sensory evaluation and volatile salt nitrogen content were used as quality indicators of squid. The results indicated that artificial simulated saliva treatment significantly reduces polyphenols and antioxidant activity in squid muscle, reduces the content of volatile base nitrogen, eliminates the astringency of squid, and improves the taste and overall quality of squid. The technique of using ultrasound technology and artificial simulated saliva is a scientific and effective method for removing astringency in squid. This method has several advantages over traditional methods, including being a non-invasive method that does not require adding any chemicals, making it an environmentally friendly solution. The use of ultrasound technology allows for removing astringency in a shorter time than traditional methods. Finally, the technique is cost-effective and easily scaled up for industrial applications. In conclusion, using ultrasound technology and artificial simulated saliva treatment is a promising method for removing astringency in squid. The technique effectively removes astringency in squid muscle, improves the taste and overall quality of the squid, and is a non-invasive, environmentally friendly, cost-effective solution that can be easily scaled up for industrial application.

The synchronous bioelectricity generation and dissimilatory nitrate reduction to ammonium (DNRA) pathway in Klebsiella variicola C1 was investigated. The presence of bioelectricity facilitated cell growth on the anodic biofilms, consequently enhancing the nitrate removal efficiency decreasing total nitrogen levels and causing a negligible accumulation of NO2 - in the supernatant. Genomic analysis revealed that K. variicola C1 possessed a complete DNRA pathway and largely annotated electron shuttles. The up-regulated expression of genes narG and nirB, encoding nitrite oxidoreductase and nitrite reductase respectively, was closely associated with increased extracellular electron transfer (EET). High-throughput sequencing analysis was employed to investigate the impact of bioelectricity on microbial community composition within cathodic biofilms. Results indicated that Halomonas, Marinobacter and Prolixibacteraceae were enriched at the cathode electrodes. In conclusion, the integration of a DNRA strain with MFC facilitated the efficient removal of wastewater containing high concentrations of NO3- and enabled the environmentally friendly recovery of NH4+.

Air-cathode microbial fuel cell (AMFC) is a promising technology with considerable potential for treating con-taminants, while obtaining energy has gained a substantial interest. The oxygen reduction reaction (ORR) per-formance of the cathode electrode is the pivotal factor for boosting AMFC ability. In this study, nitrogen-doped GO cathodic catalysts were prepared using direct heat treatment (NGO) and one-step hydrothermal method (H-NGO). The electrochemical experiments showed the AMFC equipped with NGO10 (wt% of urea: GO was 10:1) achieved the highest output voltage of 391.8 mV with a power density of 1800 mWm-3 in comparison with H-NGO and Pt/C electrodes, i.e. The diversity of bacterial communities for different biofilms was analyzed using high-throughput sequencing, the result showed the relative abundance of denitrifying bacteria including Mar-inobacter (34.9 %), Methylophaga (4.6 %), Pseudidiomarina (2.7 %) and Glaciecola (3.0 %) significantly increased at cathodic biofilms, moreover, Marinobacter, Methylophaga and Arcobacter were enriched at NGO10 cathode electrode. Reconstruction of Unobserved States (PICRUSt2) predicted differences in metabolic pathways between anode and cathode biofilm, indicating that L-threonine metabolism was significantly down-regulated, while spirilloxanthin, 2,2 '-diketo-spirilloxanthin biosynthesis and syringate degradation were significantly up -regulated. A real-time PCR (RT-PCR) represented the genes related to denitrification involving napA, nirK, nirS, nosZ and norB possessed relative higher expression in NGO10 cathode biofilm.

The mining of microbial resources has always been the focus of researchers. In the traditional microbial isolation method, due to the competition among dominant bacteria and the limitation of culture conditions, many microorganisms are unculturable, which are referred to as "microbial dark matter". Isolating bacteria before they begin to grow can eliminate interspecific competition and provide a conductive environment for subsequent cultivation. However, this approach does not alleviate the growth limitations caused by laboratory culture conditions on many microorganisms. Resuscitationpromoting factors can resuscitate and promote the growth of many bacteria. It has been widely used by researchers to isolate functional strains. Therefore, addition of the resuscitation-promoting factor can improve the isolation efficiency of low-activity and slow-growing microorganisms. However, no study has investigated the performance of the combination of these two methods. The Qinghai-Tibet Plateau harbors a huge reserve of microbial resources. The recent industrial development has accelerated resource exploitation in cold area in recent years. The fragile ecological environment of the Qinghai-Tibet Plateau is threatened by several factors including the crude oil and persistent organic pollutants. Given the prolonged low temperature environment in the plateau, digging indigenous microbial resources is of great significance to cold environment pollution remediation. In this study, we combined single-cell isolation and resuscitation-promoting factor addition. Droplet microfluidic was used to isolate single cells and resuscitation-promoting factor was added during the culture process. In this way, potentially low-temperature biphenyl-degrading strains were isolated from the surface soil samples at different altitudes of the Qinghai-Tibet Plateau. We also investigated the response of isolated strains to resuscitation-promoting factor. A total of 24 strains that could grow at low temperature (15 degrees C) with biphenyl as the sole carbon source were obtained, among which 18 strains were from the resuscitation-promoting factor addition group. Resuscitation-promoting factor addition significantly improved the efficiency of functional bacteria screen. The obtained strains belonged to 9 genera including Microbacterium. Most of the obtained strains showed obvious response to resuscitation-promoting factor, and some strains showed marked resuscitation-promoting factor dependence indicating that they almost did not grow without resuscitation-promoting factor addition. This demonstrates the mechanism by which the resuscitation-promoting factor improves single-cell isolation for functional bacteria. The successful isolation of potential low-temperature biphenyl-degrading bacteria from the Qinghai-Tibet Plateau provides the microbial resources for the subsequent prevention and control of biphenyl pollution in the Qinghai-Tibet Plateau and other cold areas. This study presents a new method for isolating and screening of functional bacteria through the combination of resuscitation-promoting factor and single-cell isolation. This method has high efficiency, low cost, and a broad application spectrum. It is a new method for the mining of "microbial dark matter".

Microbial remediation is a green and sustainable technology, but harsh environmental conditions could lead to microbial dormancy, such as entering a viable but non-culturable (VBNC) state. However, the evidence of VBNC is controversial and limited. In this study, heat stress (60 °C), one of the leading challenges for mesophilic degrading bacteria, was mimicked to investigate the physiological response of Rhodococcus biphenylivorans TG9. After 2 h of heat stress, the culturable TG9 cell count decreased from 108 cells/mL to undetectable while the viable cell count was still 105 cells/mL. The biphenyl degradation efficiency of stressed TG9 dropped by 50% compared to that of cells at logarithmic phase. During heat stress, the respiratory activity of TG9 declined dramatically while the intracellular ATP level initially increased and then decreased. Notably, the corresponding indicators recovered when restored to 30 °C. These characteristics were in consistent with bacteria entering into VBNC state. Furthermore, fluorescence activated cell sorting together with single cell as seed culture detection verified the unculturability and viability of VBNC state of TG9 cells. Also, we found that single cells in VBNC state could resuscitate and regrowth with significantly extended lag phase (LP). Our results highlight the potential of TG9 for microbial remediation and hint LP duration as an indicator for survival state of bacteria.

Molecule packing behavior at organic and graphene interface is essential for graphene-based organic electronics since charge carriers are transported within the very few organic layers nearest to graphene substrate. Although organic molecules especially the ones with planar aromatic rings usually adopt recumbent geometry on graphene substrate owning to the maximized pi-pi interaction, the alignment of organic molecules may be influenced by modifying the interfacial nature between organic molecules and graphene. Here, epitaxy growth of twodimensional ultra-thin pentacene film with standing-up molecular geometry was observed for the first time on graphene with periodic nano-sized buckling structure. The curvature and strain of graphene was found collectively responsible for the standing-up geometry of pentacene and its oriented growth on graphene surface. This study provides a feasible way for controlling molecular epitaxy on 2D materials interfaces toward functional heterostructures.

Soil microorganisms represent one of the largest biodiversity reservoirs. However, most low-abundance, slow-growing or dormant microorganisms in soils are difficult to capture with traditional enrichment culture methods. These types of microorganisms represent a valuable "microbial seed bank". To better exploit and utilize this "microbial dark matter", we developed a novel strategy that integrates single-cell-level isolation with microfluidics technology and culture with resuscitation-promoting factor (Rpf) to isolate biphenyl-degrading bacteria from four typical soils (paddy soil, red soil, alluvial soil and black soil) in eastern China. Multitudinous bacteria were successfully isolated and cultured; some of the identified clades have not been previously linked to biphenyl biodegradation, such as Actinotalea, Curtobacterium and Rothia. Soil microcosmic experiments validated that some bacteria are responsible for biphenyl degradation in soil. In addition, genomic sequencing and Illumina MiSeq sequencing of 16S rRNA genes indicated that exogenous Rpf mainly promotes the recovery and growth of bacteria containing endogenous Rpf-encoding genes. In summary, this study provides a novel strategy for capturing target functional microorganisms in soils, indicates potential bioresources for the bioremediation of contaminated soils, and enhances our current understanding of the mechanisms involved in the response to exogenous Rpf.

With the increasing demand for clean water and energy, microbial fuel cell (MFC) as a promising technology for obtaining energy from wastewater has attracted great research interest in the last two decades. The performance of the anode electrode is the most critical factor limiting the large-scale application of MFC. Graphene materials as a suitable candidate have been successfully used as the anode due to their excellent biocompatibility and efficient extracellular electron transfer (EET) ability. Here, nitrogen-doped graphene oxide (NGO) was prepared by a simple one-step hydrothermal method. X-ray photoelectron spectroscopy (XPS) was used to analyse the valence states of the surface chemical elements and their associated molecular species. Fourier transform infrared spectroscopy (FTIR) was used to identify the surface functional groups, and Raman spectroscopy was used to analyse the information about surface defects. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) revealed the increased electrochemical activity and rapid EET ability from the NGO electrodes. Scanning electron microscopy demonstrated the two-dimensional layered structure of the NGO with some wrinkled texture. MFCs equipped with the modified NGO anode achieved the highest power density of 708.3 mW/m2 with an output voltage of 498.6 mV in comparison with the other graphene-based electrodes, i.e., graphene and graphene oxide. Moreover, the chemical oxygen demand (COD) removal rate increased significantly from 18.1% to 45.6%. The analysis of the bacterial community using a high-throughput sequencing indicated that the relative abundance of the electricigens increased on the NGO electrode biofilim, and the relative expression of ccoN gene coding cytochrome-c oxidase (Cco) was markedly up-regulated. These results demonstrated that NGO modification effectively enhanced the bio-electrocatalytic activity of MFC with improved wastewater treatment capacity.

Magnetic tunnel junctions (MTJs), ferroelectric/antiferroelectric tunnel junctions (FTJs/AFTJs), and multiferroic tunnel junctions (MFTJs) have recently attracted significant interest for technological applications of nanoscale memory devices. Until now, most of them are based on perovskite oxide heterostructures with a relatively high resistance-area (RA) product and low resistance difference unfavorable for practical applications. The recent discovery of the two-dimensional (2D) van der Waals (vdW) ferroelectric (FE) and magnetic materials has opened a new route to realize tunnel junctions with high performance and atomic-scale dimensions. Here, using first-principles calculations, we propose a new type of 2D tunnel junction: an antiferroelectric magnetic tunnel junction (AFMTJ), which inherits the features of both MTJ and AFTJ. This AFMTJ is composed of monolayer CuInP2S6 (CIPS) sandwiched between 2D magnetic electrodes of CrSe2. The AFTJ with nonmagnetic electrodes of TiSe2 on both sides of CIPS and the asymmetric AFTJ with both CrSe2 and TiSe2 electrodes are also investigated. Based on quantum-mechanical modeling of the electronic transport, sizeable tunneling electroresistance effects and multiple nonvolatile resistance states are demonstrated. More importantly, a remarkably low RA product (less than 0.1 Ω·μm2) makes the proposed vdW AFMTJs superior to the conventional MFTJs in terms of their promising nonvolatile memory applications. Our calculations provide new guidance for the experiment and application of nanoscale memory devices.