Association between physical activity and visceral adiposity index (VAI) in U.S. population with overweight or obesity: a cross-sectional study.

BACKGROUND: Previous studies have revealed the effects of different physical activity (PA) types on visceral adipose tissue (VAT) accumulation in individuals with overweight/obesity. However, the independent association (especially the dose-response relationship) between PA and VAT in individuals with and without overweight/obesity remains less explored. Visceral adiposity index (VAI), calculated from waist circumference, body mass index (BMI), triglyceride and high-density lipoprotein cholesterol, is a novel indicator of VAT. This study aims to elucidate the association between PA and VAI in participants with and without overweight/obesity. METHODS: Participants who are overweight or obese and with complete data on VAI, PA, and other essential covariates from the National Health and Nutrition Examination Survey (NHANES) database (2015-2018) were included in this study. PA was evaluated by the PA questionnaire and converted into metabolic equivalent task (MET) hours per week (MET-h/wk) based on the suggested MET scores. Multivariate linear regression models were used to identify the association between PA and VAI. Subgroup analyses, combined with interaction tests and restricted cubic spline (RCS) regression analyses, were utilized to explore the stability and nonlinearity of PA-VAI association, respectively. RESULTS: A total of 4, 312 participants with complete data on PA and VAI was included in this study, with 3, 441 of them being overweight or obese. After adjusting for all potential covariates, increased PA was found to be significantly associated with remarkable lower level of VAI in all participants (ß = -0.0004, P = 0.003), participants with (ß = -0.0013, P = 0.012) and without (ß = -0.0004, P = 0.003) overweight/obesity. Subgroup analyses and interaction tests revealed that the PA-VAI association was not modified by other covariates in individuals with overweight/obesity. Furthermore, RCS analyses revealed that PA was significantly, linearly and negatively associated with VAI in all participants, participants with and without overweight/obesity (all P < 0.05, all P for nonlinearity > 0.05). Noteworthily, as opposed to individuals without overweight/obesity, PA was significantly associated with lower VAI in participants with overweight/obesity after exceeding the threshold of 150 MET-h/wk. CONCLUSION: Increased PA was significantly associated with lower level of VAI, but a higher level of PA (> 150 MET-h/wk) was needed to obtain significantly lower level of VAI in individuals with overweight/obesity.

Screening and characterization of a novel linear B-cell epitope on orf virus F1L protein.

Background: Orf, also known as contagious ecthyma (CE), is an acute, contagious zoonotic disease caused by the orf virus (ORFV). The F1L protein is a major immunodominant protein on the surface of ORFV and can induce the production of neutralizing antibodies. Methods: The prokaryotic expression system was used to produce the recombinant F1L protein of ORFV, which was subsequently purified and used to immunize mice. Positive hybridoma clones were screened using an indirect enzyme-linked immunosorbent assay (ELISA). The reactivity and specificity of the monoclonal antibody (mAb) were verified through Western blot and indirect immunofluorescence (IFA). The linear antigenic epitope specific to the mAb was identified through Western blot, using truncated F1L proteins expressed in eukaryotic cells. A multiple sequence alignment of the ORFV reference strains was performed to evaluate the degree of conservation of the identified epitope. Results: After three rounds of subcloning, a mAb named Ba-F1L was produced. Ba-F1L was found to react with both the exogenously expressed F1L protein and the native F1L protein from ORFV-infected cells, as confirmed by Western blot and IFA. The mAb recognized the core epitope 103CKSTCPKEM111, which is highly conserved among various ORFV strains, as shown by homologous sequence alignment. Conclusion: The mAb produced in the present study can be used as a diagnostic reagent for detecting ORFV and as a basic tool for exploring the mechanisms of orf pathogenesis. In addition, the identified linear epitope may be valuable for the development of epitope-based vaccines.

Molecular detection and phylogenetic analysis of Orf viruses from goats in Jiangxi province, China.

Orf is a zoonosis caused by the Orf virus (ORFV), which is endemic in goats, sheep, and wild ruminants worldwide. Orf infection is prevalent in China, with outbreaks reported in several provinces. Currently, there is limited information available regarding the characterization of ORFV strains in Jiangxi province. This study investigated an acute outbreak of Orf that occurred in 2021 in a goat herd in the Jiangxi province of China. Clinical signs in this case included lesions on the lips, nose, and inside the mouth. The presence of ORFV was confirmed from tissue samples by polymerase chain reaction (PCR). The nucleotide sequences of the B2L and F1L genes were fully sequenced and used to construct phylogenetic trees. The results of this investigation identified the ORFV JXxy2021 as the cause of the outbreak. The phylogenetic analysis revealed that the ORFV strain JXxy2021 had the highest similarity to the ORFV strains GO and FJ-SL from the neighboring province of Fujian. This suggests that JXxy2021 was likely transmitted from Fujian province. The results have provided valuable information on the genetic characteristics of JXxy2021 and the endemic situations of Orf in China.

Experimental Warming Increased Cooked Rice Stickiness and Rice Thermal Stability in Three Major Chinese Rice Cropping Systems.

Climate warming is a critical environmental issue affecting rice production. However, its effects on cooked rice texture and rice thermal properties remain unstudied in China. To address this gap, we conducted a two-year multi-site field warming experiment using free-air temperature increase facilities across three major Chinese rice cropping systems. Interestingly, warming had a minimal impact on the hardness of cooked rice, while it significantly increased stickiness by an average of 16.3% under warming conditions. Moreover, compared to control treatments, rice flour exhibited a significant increase in gelatinization enthalpy, onset, peak, and conclusion temperatures under warming conditions, with average increments of 8.7%, 1.00 °C, 1.05 °C, and 1.17 °C, respectively. In addition, warming significantly declined the amylose content, remarkedly elevated the protein content and relative crystallinity, and altered the weight distribution of the debranched starch. Correlation analysis revealed significant relationships between cooked rice stickiness, rice flour thermal properties, amylose content, protein content, and partial starch structures. Therefore, warming-induced alterations in rice composition and starch structure collectively enhanced cooked rice stickiness and rice thermal stability.

Complete coding genome sequence of a Teschovirus A genotype strain.

This study reports the complete coding genome sequence of a novel Teschovirus A genotype strain, SG2, isolated from the fecal sample of an infected indigenous pig in western Jiangxi, China.

Starch multiscale structure and physicochemical property alterations in high-quality indica rice quality and cooked rice texture under different nitrogen panicle fertilizer applications.

The starch multiscale structure, physiochemical properties, grain quality and cooked rice texture of high-quality early and late indica were analyzed under nitrogen panicle fertilizer (low panicle fertilizer, LPF; middle panicle fertilizer, MPF; high panicle fertilizer, HPF) treatments and their internal relations were investigated. Compared to the MPF treatment, the starch granules in HPF and LPF had more surface-proteins and irregular voids for high-quality early and late indica rice cultivars, respectively. Nitrogen panicle fertilization application increased amylopectin medium and long chains as well as protein content, resulting in higher relative crystallinity and gelatinization temperatures. Moderate changes in starch multistructures and physicochemical properties such as branching degree, amylopectin medium chain, and pasting viscosities derived from MPF treatment significantly improved processing, appearance qualities and cooked rice texture. Additionally, the decrease in starch branching, gelatinization temperatures, and granule uniformity along with an increase in large granules, breakdown, and △Hgel under MPF treatment were the main reasons for improving rice textural properties.

Grain yield and quality performances of different late-season rice cultivars in response to experimental warming in subtropical China.

Introduction: Climate warming has pronounced effects on rice production in China. However, late-seasons rice cultivars are diverse in double rice cropping systems, and the actual responses in grain yield and quality of different late-season rice cultivars to climate warming are still unclear. Methods: A two-year field warming experiment was conducted by using free-air temperature increase facilities with three widely-planted late-season rice cultivars, including Taiyou398 (TY, short growth duration indica hybrid rice), Jiuxiangnian (JXN, long growth duration indica inbred rice), and Yongyou1538 (YY, long growth duration indica-japonica hybrid rice) in a double rice cropping system in subtropical China. Results: Warming (1.9-2.0°C) had no significant effects on the grain yields of TY and JXN, but significantly decreased that of YY by 4.8% relative to ambient treatment due to a reduction of spikelet number. Compared to ambient treatment, the head rice yields of TY and YY did not change while that of JXN increased by 6.3% under warming conditions. Warming significantly increased the head rice rates of JXN and YY by 6.6% and 7.8%, and the chalky grain rates of TY, JXN, and YY by 79.1%, 21.6%, and 7.6%, respectively. Under warming conditions, the amylose content of JXN and YY decreased significantly by 7.5% and 8.8%, and the setback of three cultivars decreased significantly by an average of 41.5%. Conclusion: Warming could improve the milling and eating qualities of long growth duration late-season rice (JXN and YY) and increase or maintain their head rice yield, even though decreased the grain yield of indica-japonica hybrid rice (YY). These results will provide a better understanding for the selection of suitable late-season rice cultivars under future climate warming conditions.

All-printed multiplexed electrocatalytic biosensors with rationally designed nanoparticle inks.

Inkjet printing, capable of rapid and template-free fabrication with high resolution and low material waste, is a promising method to construct electrochemical biosensor devices. However, the construction of fully inkjet-printed electrochemical biosensor remains a challenge owing to the lack of appropriate inks, especially the sensing inks of bioactive materials. Herein, we demonstrate a fully inkjet-printed, integrated and multiplexed electrochemical biosensor by combining rationally designed nanoparticle Inks. The stable gold (Au) nanoparticles ink with lower sintering temperature is prepared by using L-cysteine as stabilizer, and it is used to print the interconnects, the counter electrodes, and the working electrodes. The SU-8 ink is used to serve as dielectric layer for the biosensor, whereas the silver electrode is printed on the Au electrode by using commercially silver nanoparticles ink before it is chlorinated to prepare Ag/AgCl reference electrode. Moreover, we synthesize an inkjet-printable and electroactive ink, by the 'one-pot method', which is composed of conductive poly 6-aminoindole (PIn-6-NH2) and gold-palladium (Au-Pd) alloy nanoparticle (Au-Pd@PIn-6-NH2) to enhance the sensing performance of gold electrode towards hydrogen peroxide (H2O2). Especially, the amino groups in PIn-6-NH2can be further used to immobilizing glucose oxidase (GOx) and lactic acid oxidase (LOx) by glutaraldehyde to prepare printable sensing ink for the detection of glucose and lactate. The fully inkjet-printed electrochemical biosensor enabled by advanced inks can simultaneously detect glucose and lactate with good sensitivity and selectivity, as well as facile and scalable fabrication, showing great promise for metabolic monitoring.

PEDOT:PSS hydrogels with high conductivity and biocompatibility for in situ cell sensing.

Conducting polymer hydrogels, especially poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) hydrogels, show great promise in soft bioelectronics due to their high conductivity and the ability of electrical coupling with tissues for sensing and stimulation. However, it is challenging to solve the problem of poor biocompatibility of PEDOT:PSS hydrogels due to the existing harsh preparation methods with the use of toxic and harmful reagents. Herein, we report the synthesis of PEDOT:PSS hydrogels with positively charged conductive polymers as a cross-linker and the application of PEDOT:PSS hydrogels as in situ electrochemical sensors for living cells. The conductivities of PEDOT:PSS hydrogels prepared using this method without any toxic or harmful reagents can reach up to 3265 S m-1. The facile synthesis approach with a simple mixture of PEDOT:PSS aqueous solution and the monomers of conductive polymers at room temperature also enables the printability of PEDOT:PSS hydrogels to fabricate patterned electrodes. Moreover, all the proposed PEDOT:PSS hydrogels demonstrated good biocompatibility. The in situ electrochemical detection of dopamine secreted from PC12 cells cultured within PEDOT:PSS hydrogels suggests that our PEDOT:PSS hydrogels with high conductivity and biocompatibility offer great potential for the integration of biosensors within 3D cell culture.

Genome-resolved metagenomics reveals depth-related patterns of microbial community structure and functions in a highly stratified, AMD overlaying mine tailings.

Acid mine drainage (AMD) is a worldwide environmental problem, yet bioremediation is hampered by a limited knowledge of the reductive microbial processes in the AMD ecosystem. Here, we generate extensive metagenome and geochemical datasets to investigate how microbial populations and metabolic capacities driving major element cycles are structured in a highly stratified, AMD overlaying tailings environment. The results demonstrated an explicit depth-dependent differentiation of microbial community composition and function profiles between the surface and deeper tailings layers, paralleling the dramatic shifts in major physical and geochemical properties. Specifically, key genes involved in sulfur and iron oxidation were significantly enriched in the surface tailings, whereas those associated with reductive nitrogen, sulfur, and iron processes were enriched in the deeper layers. Genome-resolved metagenomics retrieved 406 intermediate or high-quality genomes spanning 26 phyla, including major new groups (e.g., Patescibacteria and DPANN). Metabolic models involving nitrogen, sulfur, iron, and carbon cycles were proposed based on the functional potentials of the abundant microbial genomes, emphasizing syntrophy and the importance of lesser-known taxa in the degradation of complex carbon compounds. These results have implications for in situ AMD bioremediation.

Phytostabilization mitigates antibiotic resistance gene enrichment in a copper mine tailings pond.

Mining-impacted environments are distributed globally and have become increasingly recognized as hotspots of antibiotic resistance genes (ARGs). However, there are currently no reports on treatment technologies to deal with such an important environmental problem. To narrow this knowledge gap, we implemented a phytostabilization project in an acidic copper mine tailings pond and employed metagenomics to explore ARG characteristics in the soil samples. Our results showed that phytostabilization decreased the total ARG abundance in 0-10 cm soil layer by 75 %, which was companied by a significant decrease in ARG mobility, and a significant increase in ARG diversity and microbial diversity. Phytostabilization was also found to drastically alter the ARG host composition and to significantly reduce the total abundance of virulence factor genes of ARG hosts. Soil nutrient status, heavy metal toxicity and SO42- concentration were important physicochemical factors to affect the total ARG abundance, while causal mediation analysis showed that their effects were largely mediated by the changes in ARG mobility and microbial diversity. The increase in ARG diversity associated with phytostabilization was mainly mediated by a small subgroup of ARG hosts, most of which could not be classified at the genus level and deserve further research in the future.

Metagenomic and metatranscriptomic insights into sulfate-reducing bacteria in a revegetated acidic mine wasteland.

The widespread occurrence of sulfate-reducing microorganisms (SRMs) in temporarily oxic/hypoxic aquatic environments indicates an intriguing possibility that SRMs can prevail in constantly oxic/hypoxic terrestrial sulfate-rich environments. However, little attention has been given to this possibility, leading to an incomplete understanding of microorganisms driving the terrestrial part of the global sulfur (S) cycle. In this study, genome-centric metagenomics and metatranscriptomics were employed to explore the diversity, metabolic potential, and gene expression profile of SRMs in a revegetated acidic mine wasteland under constantly oxic/hypoxic conditions. We recovered 16 medium- to high-quality metagenome-assembled genomes (MAGs) containing reductive dsrAB. Among them, 12 and four MAGs belonged to Acidobacteria and Deltaproteobacteria, respectively, harboring three new SRM genera. Comparative genomic analysis based on seven high-quality MAGs (completeness >90% and contamination <10%; including six acidobacterial and one deltaproteobacterial) and genomes of three additional cultured model species showed that Acidobacteria-related SRMs had more genes encoding glycoside hydrolases, oxygen-tolerant hydrogenases, and cytochrome c oxidases than Deltaproteobacteria-related SRMs. The opposite pattern was observed for genes encoding superoxide reductases and thioredoxin peroxidases. Using VirSorter, viral genome sequences were found in five of the 16 MAGs and in all three cultured model species. These prophages encoded enzymes involved in glycoside hydrolysis and antioxidation in their hosts. Moreover, metatranscriptomic analysis revealed that 15 of the 16 SRMs reported here were active in situ. An acidobacterial MAG containing a prophage dominated the SRM transcripts, expressing a large number of genes involved in its response to oxidative stress and competition for organic matter.

Analysis of the Influence of Network Continuous Care on the Quality of Life of Patients with Coronary Artery Disease (CAD) after PIC.

Studies have shown that most patients after PCI cannot adhere to the cardiac rehabilitation program. The survey found that due to the lack of secondary prevention of cardiac rehabilitation, the phenomenon of drug reduction and withdrawal after PCI is very common after discharge, leading to recurrence of the patient's disease or worsen and repeated hospitalizations, so continuity of care is very important. In this paper, in addition to proposing a network care continuum with artificial intelligence handler in order to improve the healthcare system and provide new ideas for improving the postoperative recovery of CHD patients, we analyze the impact of PCI on the coronary heart disease patients' PCI postoperative quality of life. In the method part, this article introduces the concepts of continuation care and PCI after surgery, introduces the marker delivery algorithm in the field of artificial intelligence, and introduces the SF-36 scale for patient quality of life analysis. This article designs an experiment combining artificial intelligence processors to carry out network continuity care for patients and divides 100 eligible patients into an experimental group and a control group. In the analysis part, the two groups of patients were analyzed in terms of general data comparison, physical function, biochemical indicators, quality of life, and dependence. It can be seen from the experimental analysis that the anxiety and depression of the two groups of subjects have different degrees of decline. The HAMA value of the experimental group is 9.06 ± 0.77, and the HAMD value is 9.18 ± 1.20, which is significantly lower than that of the control group, P < 0.05. It can be seen that the use of network continuation care can reduce the negative emotions of patients more than general care. Through psychological counseling and postoperative follow-up, it can improve the optimism and positive emotions of the patients, reduce the negative emotions of the patients, and improve it to a certain extent.

Relation of cooked rice texture to starch structure and physicochemical properties under different nitrogen managements.

Nitrogen management, especially panicle nitrogen fertilization (PNF), can affect cooked rice textures by altering starch quality, but the details are unclear. In this study, the starch multi-level structures, physicochemical properties and cooked rice textures of indica under different nitrogen managements were analysed and their internal relations were investigated. With an increase in PNF, large granules, amylopectin short chains, amylose content, thermal temperatures, setback, and hardness first exhibited decreasing trends and then increasing trends, which were relatively lower under moderate PNF (N3), whereas α-1,6 linkage, relative crystallinity, protein content, enthalpy of gelatinization (△Hgel), peak viscosity, breakdown and stickiness exhibited the opposite trends. N3 treatment significantly increased △Hgel and breakdown and decreased setback, hardness and chewiness, suggesting that it might contribute to better starch thermal stability and pasting properties, ultimately improving cooked rice texture. Nitrogen management affected the texture of cooked rice mainly by improving starch multi-level structures, thermal and pasting viscosities.

Template-free, controllable and scalable synthesis of poly(5-aminoindole) nanoparticles for printable electrochemical immunosensor with ultra-high sensitivity.

Conductive polymer polyindole derivatives have good conductivities and abundant functional groups, which would offer great potential for versatile applications including biosensors, bioelectronics and energy devices. However, the polyindole derivatives are mainly synthesized by the electropolymerization method on conductive electrode surfaces, which limits large-scale synthesis and practical applications. Herein, we explore a strategy of template-free, controllable and scalable synthesis of poly-5-aminoindole (PIn-5-NH2) nanoparticles (NPs) and demonstrate the application of PIn-5-NH2 NPs in printable multiplexed electrochemical biosensors with ultra-high sensitivity. The synthesis of PIn-5-NH2 NPs is based on a self-templated method since the In-5-NH2 monomer with amphiphilic structures can form micelles by self-assembly in an aqueous solution. The diameter of PIn-5-NH2 NPs could be controlled by adjusting the synthesis conditions, such as monomer concentration, oxidant/monomer ratio and reaction time. The PIn-5-NH2 NPs possess distinct features, including good conductivity, large surface area, and abundant -NH2 functional groups for covalent binding of the antibody, and therefore offer substantial possibilities for developing an all-printable process to fabricate multiplexed electrochemical immunosensors. The printed multiplexed electrochemical immunosensors on the basis of the aqueous suspension of PIn-5-NH2 NPs linked with antibodies can simultaneously detect multiple cancer markers, and exhibit high sensitivity and good selectivity. Our facile and scalable synthesis strategy would offer great opportunities for versatile applications of PIn-5-NH2 NPs.

Genomic Insights into the Ecological Role and Evolution of a Novel Thermoplasmata Order, "Candidatus Sysuiplasmatales".

Recent omics studies have provided invaluable insights into the metabolic potential, adaptation, and evolution of novel archaeal lineages from a variety of extreme environments. We utilized a genome-resolved metagenomic approach to recover eight medium- to high-quality metagenome-assembled genomes (MAGs) that likely represent a new order ("Candidatus Sysuiplasmatales") in the class Thermoplasmata from mine tailings and acid mine drainage (AMD) sediments sampled from two copper mines in South China. 16S rRNA gene-based analyses revealed a narrow habitat range for these uncultured archaea limited to AMD and hot spring-related environments. Metabolic reconstruction indicated a facultatively anaerobic heterotrophic lifestyle. This may allow the archaea to adapt to oxygen fluctuations and is thus in marked contrast to the majority of lineages in the domain Archaea, which typically show obligately anaerobic metabolisms. Notably, "Ca. Sysuiplasmatales" could conserve energy through degradation of fatty acids, amino acid metabolism, and oxidation of reduced inorganic sulfur compounds (RISCs), suggesting that they may contribute to acid generation in the extreme mine environments. Unlike the closely related orders Methanomassiliicoccales and "Candidatus Gimiplasmatales," "Ca. Sysuiplasmatales" lacks the capacity to perform methanogenesis and carbon fixation. Ancestral state reconstruction indicated that "Ca. Sysuiplasmatales," the closely related orders Methanomassiliicoccales and "Ca. Gimiplasmatales," and the orders SG8-5 and RBG-16-68-12 originated from a facultatively anaerobic ancestor capable of carbon fixation via the bacterial-type H4F Wood-Ljungdahl pathway (WLP). Their metabolic divergence might be attributed to different evolutionary paths. IMPORTANCE A wide array of archaea populate Earth's extreme environments; therefore, they may play important roles in mediating biogeochemical processes such as iron and sulfur cycling. However, our knowledge of archaeal biology and evolution is still limited, since the majority of the archaeal diversity is uncultured. For instance, most order-level lineages except Thermoplasmatales, Aciduliprofundales, and Methanomassiliicoccales within Thermoplasmata do not have cultured representatives. Here, we report the discovery and genomic characterization of a novel order, "Ca. Sysuiplasmatales," within Thermoplasmata in extremely acidic mine environments. "Ca. Sysuiplasmatales" are inferred to be facultatively anaerobic heterotrophs and likely contribute to acid generation through the oxidation of RISCs. The physiological divergence between "Ca. Sysuiplasmatales" and closely related Thermoplasmata lineages may be attributed to different evolutionary paths. These results expand our knowledge of archaea in the extreme mine ecosystem.

Characterization of porcine sapelovirus prevalent in western Jiangxi, China.

BACKGROUND: Porcine sapelovirus (PSV) infection can lead severe polioencephalomyelitis with high morbidity and mortality, which result in significant economic losses. Infection with the PSV is believed to be common yet limited information is available on the prevalence and molecular characterization of PSV in China. Therefore, the objective of this study was to characterize the prevalence and genome of PSV strains identified in the western Jiangxi province of China. RESULTS: A high specificity and sensitivity SYBR Green I-based RT-PCR method for PSV detection was developed. Two hundred and ninety four fecal samples were collected from December 2018 to March 2019 in 4 farms. An overall PSV-positivity rate of 11.22% (33/294) was detected with the real-time RT-PCR method, and a high infection rate and viral load of PSV were found in nursery pigs. In total, complete VP1 gene sequences of 11 PSV strains (PSV-YCs) were obtained. Homology comparisons of the VP1 gene of the 11 PSV-YCs with previously reported PSVs revealed nucleotide sequence identities ranging from 63% to 96.8%, and deduced amino acid sequence identities from 61.4% to 99.7%. Phylogenetic analyses based on the VP1 gene exhibited 2 main clades corresponding to PSV-1 and PSV-2, and all PSV-YCs prevalent in western Jiangxi belonged to the traditional genotype (PSV-1). In addition, the pairwise distances of VP1 gene sequences between PSV-YCs ranged from 0.009 to 0.198, which indicating that substantial genetic diversity among the PSVs in western Jiangxi. CONCLUSIONS: To the authors' knowledge, this is the first description of PSV in the Jiangxi province pig herds in China, and it is crucial to understand the epidemiology of the viruses in China. The results also provide an important theoretical foundation for diagnosis and early warning of epidemic diseases caused by PSVs prevailing in this region.

Highly Conductive PPy-PEDOT:PSS Hybrid Hydrogel with Superior Biocompatibility for Bioelectronics Application.

Conductive polymer hydrogels (CPHs) hold significant promise in broad applications, such as bioelectronics and energy devices. Hitherto, the development of a facile and scalable synthesis method for CPHs with high electrical conductivity and biocompatibility has still been a challenge. Herein, we demonstrate highly conductive PPy-PEDOT:PSS hybrid hydrogels which are prepared by a simple solution-mixing method. This fabrication method involves the mixing of a pyrrole monomer with a PEDOT:PSS dispersion, followed by in situ chemical oxidative polymerization to form polypyrrole (PPy). The electrostatic interaction between negatively charged PSS and positively charged conjugated PPy facilitates the formation of PPy-PEDOT:PSS hybrid hydrogels. The conductivity of the PPy-PEDOT:PSS hybrid hydrogels is 867 S m-1. The PPy-PEDOT:PSS hybrid hydrogels show excellent biocompatibility. Moreover, the PPy-PEDOT:PSS hybrid hydrogels have a hierarchical porous structure which facilitates the 3D cell culture within the hydrogels. The PPy-PEDOT:PSS hybrid hydrogels exhibit excellent in situ biomolecular detection and real-time cell proliferation monitoring performance, indicating their potential as highly sensitive electrochemical biosensors for bioelectronics applications. Our strategy for the fabrication of CPHs with the electrostatic interaction between the negatively charged conductive polymer and positively charged conductive polymer would provide new opportunities for the design of highly conductive conjugated hydrogels for bioelectronics applications and energy devices.

Poly(indole-5-carboxylic acid)/reduced graphene oxide/gold nanoparticles/phage-based electrochemical biosensor for highly specific detection of Yersinia pseudotuberculosis.

Yersinia pseudotuberculosis is an enteric bacterium causing yersiniosis in humans. The existing Yersinia pseudotuberculosis detection methods are time-consuming, requiring a sample pretreatment step, and are unable to discriminate live/dead cells. The current work reports a phage-based electrochemical biosensor for rapid and specific detection of Yersinia pseudotuberculosis. The conductive poly(indole-5-carboxylic acid), reduced graphene oxide, and gold nanoparticles are applied for surface modification of the electrode. They possess ultra-high redox stability and retain 97.7% of current response after performing 50 consecutive cycles of cyclic voltammetry.The specific bacteriophages vB_YepM_ZN18 we isolated from hospital sewage water were immobilized on modified electrodes by Au-NH2 bond between gold nanoparticles and phages. The biosensor fabricated with nanomaterials and phages were utilized to detect Yersinia pseudotuberculosis successfully with detection range of 5.30 × 102 to 1.05 × 107 CFU mL-1, detection limit of 3 CFU mL-1, and assay time of 35 min. Moreover, the biosensor can specifically detect live Yersinia pseudotuberculosis without responding to phage-non-host bacteria and dead Yersinia pseudotuberculosis cells. These results suggest that the proposed biosensor is a promising tool for the rapid and selective detection of Yersinia pseudotuberculosis in food, water, and clinical samples.

The role of intestinal microbiota of the marine fish (Acanthopagrus latus) in mercury biotransformation.

Both inorganic (IHg) and organic (MeHg) forms of Hg can be converted into each other by methylation or demethylation, leading to changes of Hg speciation and distribution in fish. However, Hg biotransformation in fish is not thoroughly understood and the key factors in this process are unclear. The present study investigated the in vivo Hg transformation in a marine fish (Acanthopagrus latus) and explored the roles of intestinal microbiota in Hg biotransformation. We first demonstrated that Hg methylation or demethylation occurred in the fish gut under dietary IHg or MeHg exposure, respectively. The demethylation was observed to be faster than methylation, suggesting that demethylation could significantly influence the Hg speciation in fish. This study also strongly suggested that intestinal microbiota played a predominant role in Hg biotransformation and thus significantly affected the overall Hg accumulation and distribution in fish body. The richness of Hg methylators or demethylators was elevated under IHg or MeHg treatment, respectively. Furthermore, the intestinal microbiota composition was also altered by Hg exposure. This study highlights the importance of intestinal microbiota in Hg biotransformation in fish body, and suggests that modulating the gut microbiome could be a possible solution to minimize Hg contamination in fish.