This study investigates the influence of different anaerobic electron acceptors on the corrosion of Q235 carbon steel affected by Vreelandella titanicae IO. It was found that corrosion was accelerated when nitrate was utilized as the electron acceptor by the bacterium, while inhibited with fumarate. Genomic and metabolomic analyses revealed that gallic acid (GA) was secreted when nitrate was the electron acceptor, but it was absent in the case of fumarate. GA injection promoted steel corrosion in V. titanicae IO cultures but had no effect in sterile media, confirming its role in extracellular electron transfer (EET). The findings suggest that the EET capability of V. titanicae IO was regulated by the type of electron acceptors, with GA mediating EET only in the presence of nitrate. This study provides new insights into the mechanisms of microbiologically influenced corrosion (MIC) and highlights the potential for controlling corrosion through the manipulation of microbial electron transfer pathways.

Sulfate-reducing bacteria (SRB) play crucial roles in bioenergy production and bioremediation due to their ubiquitous distribution in diverse environments. The well-characterized dsrA and dsrB genes, encoding key subunits of dissimilatory sulfite reductase, are widely employed as phylogenetic markers for SRB identification and molecular analysis. In this study, we developed a target-assisted sensing platform for the analysis of dsrA and dsrB gene fragments based on CRISPR/Cas12a integrated with Au/Fe₃O₄ nanocomposites (Au/Fe₃O₄NCs). This ultrasensitive biosensor combines the trans-cleavage activity of CRISPR/Cas12a with a gold–iron oxide nanocomposite vector and Cas12a/crRNA-mediated rolling circle amplification to enable simultaneous dual-target detection. The sensing strategy relies on the fluorescence quenching property of gold nanoparticles to achieve a "signal-off to signal-on" response upon target recognition, while rolling circle amplification is employed to generate amplicons that activate the CRISPR/Cas12a system, thereby inducing cleavage of a reporter probe to produce fluorescence for enhanced signal output. The platform achieved detection limits as low as 2.75 fM for dsrA and 0.5 fM for dsrB, along with excellent sensitivity, specificity, and stability. Its practical utility was further confirmed by effective analysis of seawater and serum samples, pointing to promising applications in both environmental and biomedical fields.

This study revealed the function and mechanism of transcutaneous electrical nerve stimulation (TENS) in a rat model of lateral ankle sprain (LAS). The LAS rat model was randomly divided into Low/Medium/High intensity of TENS groups, Sham group, and Model control group. After 1, 2, and 3 weeks of treatment, the improvement of LAS rar was measured by gait analysis, morphology, micro-CT, osteogenesis markers, etc. The expressions of IL-1β/CXCL-10/NF-kB of ankle joint were analyzed by PCR, IF, IHC and WB. Furthermore, comprehensive profiling of differential gene expression in the LAS rat model was conducted through transcriptome sequencing. Following intra-articular reinfusion of chondrocytes induced by TENS and the downregulation of CXCL-10 expression, the improvements were analyzed. After TENS treatment, compared with the model control group, the ankle degeneration score increased in the medium/high intensity of TENS groups (P < 0.05). The degree of inclined plane test increased in the low intensity of TENS group (P < 0.05). The average step length, step frequency increased in the TENS group (P < 0.05). The bone mineral density (BMD)/ bone mineral content (BMC) increased in the TENS groups. The bio-mechanical indicators of LAS rats increased in the TENS groups (P < 0.05). The cartilage thickness of the LAS rat increased in the TENS groups (P < 0.05). There were 7 gene targets of LAS rat that were closely related to the IL-17 signaling pathway; TENS down-regulated the CXCL-10/IL-1β/NF-kB expressions (P < 0.0). After chondrocyte reinfusion which induced with TENS, similar improvements in LAS rats were obtained. TENS could improve the motor function and promote the osteogenic and chondrogenic effects in LAS rats. TENS inhibited the inflammation by regulating the IL-1β/CXCL-10/NF-kB expression. The chondrocyte reinfusion with low-expressed CXCL-10, which was induced by TENS, improved the LAS rat. TENS, chondrocyte reinfusion and CXCL-10 inhibitor had a potential effect on LAS in the clinic. In this study, a lateral ankle sprain (LAS) rat model was duplicated and treated with transcutaneous electrical nerve stimulation (TENS). After a period of treatment with TENS, the improvement of TENS in LAS rats was analyzed. The different regulated gene of articular cartilage was obtained by transcriptome analysis. In vitro, the CXCL-10/NF-kB expressions were analyzed and prepared as an intra-articular injection for LAS rats. Then, the chondrocyte whose CXCL-10/NF-kB expression were down-regulated and its therapeutic improvement was analyzed. The aim of this study is to elucidate the function and mechanism of TENS in LAS rats. This study found that TENS could improve the motor function and promote the osteogenic and chondrogenic effects on LAS rats. TENS inhibited the inflammation by regulating the IL-1β/CXCL-10/NF-kB expression. Reinfusion of chondrocytes with low levels of CXCL-10 yields comparable effects to TENS in LAS rats. Collectively, TENS, demonstrate a promising clinical potential for the treatment of LAS. Furthermore, chondrocyte reinfusion might become a therapeutic approach, substantial technical barriers currently limit its clinical applicability.

Knee osteoarthritis (KOA) is a common degenerative bone disease, and transcutaneous electrical nerve stimulation (TENS) is an alternative and complementary therapy (ACM). This study revealed the role of TENS in regulating the intestinal microbiota in KOA rats. This study concentrated on the intestinal microbiota of KOA rats which were treated with TENS for 1, 2, and 3 weeks. Three intensities of TENS were used to treat KOA rats, and the expressions of IL6/8, PI3K-AKT were measured. The intestinal microbiota was analyzed by 16 S rDNA sequencing. Compared with the Model Control group, TENS could improve symptoms of KOA rats and inhibit the expressions of IL6/8 by down-regulating the PI3K-AKT expression. After 3 weeks of treatment with TENS, compared with the Model Control group, the abundances of Bacteroidetes, Bacteroidetes, and Thermodesulfobacteria increased in the TENS groups; the abundances of Ficmicutes, Campylobacter, and Verruca decreased in the TENS groups. TENS could improve the histomorphology of knee and inhibit inflammation in KOA rats. After treatment with TENS, the intestinal microbiota gradually changed from 1,2,3 weeks and the abundance of them was different with three intensities of TENS. Further study will elucidate the underlying mechanisms of TENS in altering gut microbiota and the potential therapeutic applications of these intestinal microbiota for KOA.

Early detection and diagnosis are essential for effectively preventing and treating complex pathogenic bacterial infections. This study presents an innovative approach for on-site, ultrasensitive pathogen detection by integrating a uniquely designed probe binding mode with novel nanomaterial structures within a lateral flow immunoassay (LFIA) platform. Through a galvanic replacement reaction, gold is non-uniformly deposited onto a silver core, resulting in the formation of Ag@pore-Au structures. The abundant nanopores and porous surface of these structures create a high density of "hot spots", significantly enhancing their surface-enhanced Raman scattering (SERS) performance. We systematically characterized the SERS and detection capabilities of the synthesized Ag@pore-Au Raman-dye micron particles (MPs) probe. The results conclusively demonstrated that this structural probe exhibits a robust SERS signal, paving the way for its successful application in LFIA. By integrating the Ag@pore-Au Raman-dye MPs probe into the LFIA platform, we achieved rapid, quantitative detection of Escherichia coli and Staphylococcus aureus. This enhanced platform overcomes the limitations of traditional LFIA, notably its high detection limit of 10 CFU/mL and its inability to provide quantitative results. Furthermore, a dual-channel detection mode enabled the simultaneous and specific identification of both bacterial strains. The platform's efficacy was validated through successful detection in real sample matrices. This research offers novel insights and methodologies for pathogen detection in the medical field, providing an effective solution for on-site pathogen diagnosis and real-time environmental monitoring.

BACKGROUND:This study revealed the function and mechanism of the intestinal microbiota in knee osteoarthritis (KOA) rats treated using transcutaneous electrical nerve stimulation (TENS). METHODS:KOA model rats were randomly divided into low-/medium-/high-intensity TENS groups, sodium hyaluronate (SH)-positive control group (SH), and model control group (KOA rat). After 1, 2, and 3 weeks of treatment, the improvement in KOA severity was assessed, and the expression of interleukin-1β (IL-1β)/IL-6/IL-8/bone morphogenetic protein 2 (BMP-2)/transforming growth factor β (TGF-β) was analyzed. The diversity of the intestinal microbiota in KOA rats was analyzed via 16S ribosomal DNA (rDNA) sequencing. After fecal microbiota transplantation (FMT), which was induced by TENS, the improvement in the intestinal microbiota in KOA rats was analyzed. RESULTS:After 3 weeks of treatment using TENS, compared to those in the model control group, the biomechanical parameters increased in the SH and TENS groups (p < 0.05); the gait parameters improved in the SH and TENS groups; the bone mineral density (BMD) increased in the TENS group (p < 0.05); the Mankin scores of the distal femur and proximal tibiofibular muscles decreased in the SH and TENS groups (p < 0.05). IL-1β/6/8 expression levels decreased in the SH and TENS groups (p < 0.05). BMP-2/TGF-β expression in the distal femur increased in the TENS group (p < 0.05). 16S rDNA sequencing revealed that the intestinal microbiota of KOA rats was changed after TENS treatment, including increases in Escherichia-Shigella, Lachnospira, Eubacterium, Gastranaerophilales, and Rikenellaceae RC9 and decreases in Fusicatenibacter and Mycoplasma. After FMT, which is induced by TENS, similar improvements in KOA rats were obtained. CONCLUSIONS:TENS promoted anti-inflammatory and osteogenic effects by downregulating the Il-1β/6/8 expression levels and upregulating the BMP-2/TGF-β signaling pathway. 16S rDNA sequencing revealed that the intestinal microbiota of KOA rats was changed after TENS treatment via the gut-knee joint axis, and that these dominant genera of FMT elicited improvements in KOA rats. TENS caused improvements in KOA rats by regulating the intestinal microbiota; thus, TENS and induced FMT altered intestinal microbiota suggest a potential novel therapeutic avenue for KOA in clinical settings.

Licorice (Glycyrrhiza uralensis) roots are among the most widely used medicinal raw materials in traditional medicine and in numerous industries, with their polysaccharides serving as key bioactive constituents responsible for immunomodulation, tissue repair, and drug synergy. However, the low extraction yield and quality of the polysaccharides limit their extensive utilization. Presently, a highly efficient method for the extraction of polysaccharides from G. uralensis roots is lacking. Here, we developed an ultrasound-assisted deep eutectic solvent (UDE) method for extracting high-yield and premium-quality polysaccharides from G. uralensis roots. Eight extraction methods were systematically compared using deep eutectic solvents (DESs) and water as extraction media under various processing modes, including heat conduction, alkaline treatment, enzymatic hydrolysis, microwave irradiation, and ultrasound. Comparative analysis indicated that the UDE method resulted in the highest polysaccharide yield of 18.56% with a 1.71-fold increase over hot water extraction. UDE-extracted polysaccharides exhibited lower molecular weight, smaller particle size, higher solubility, improved thermal stability, and enriched galacturonic acid content, forming a weak gel-like structure with high elastic modulus. Density functional theory and independent gradient model analyses revealed that the DESs interacted with monosaccharide units through extensive hydrogen bonding and van der Waals forces. The UDE-extracted polysaccharides also displayed strong radical scavenging activity similar to vitamin C, and they alleviated IL-13-induced inflammation in BEAS-2B cells by reducing nitric oxide production, restoring antioxidant enzyme activity, and suppressing the STAT6/MYD88 axis. Thus, a green, efficient, and scalable UDE-mediated method is established for extracting highly bioactive polysaccharides for applications in numerous fields.

The persistent threat of infectious diseases underscores the critical need for point-of-care diagnostic tools that are both rapid and ultrasensitive. This study addresses this challenge by developing a novel dual-mode lateral flow assay (LFA) platform powered by a programmable, DNA framework-assembled surface-enhanced Raman scattering (SERS) nanotag. The innovation lies in the rational integration of a high-load SERS signal core and a tailored plasmonic enhancer through DNA nanotechnology. First, a three-dimensional rolling circle amplification (RCA)-DNA nanoassembly scaffold was fabricated RCA reaction. Pre-synthesized Raman signal probes conjugated with gold nanoparticles were then immobilized onto this scaffold. Because the RCA template had been designed to include bacteria-specific primers, the assembled DNA-based SERS nanotag exhibits both the ability to specifically capture target microorganisms and the capacity for strong SERS signal output. When deployed on a standard LFA strip, this nanotag enables two distinct yet complementary detection modes: a rapid colorimetric readout for immediate, instrument-free screening and a quantitative SERS measurement for ultrasensitive confirmation. The platform enabled rapid visual detection via test strips within 20 min and achieved single-digit colony SERS quantification, demonstrating an ultrasensitive detection limit while retaining high specificity and robustness in complex sample matrices. This work establishes a versatile and powerful paradigm for nextgeneration point-of-care diagnostics, merging the convenience of rapid testing with the precision of laboratory-grade quantification, and highlights the transformative potential of synthetic biology in advanced biosensing.

Globally, ballast water is a significant vector for the translocation of microorganisms across marine regions, posing potential ecological and public health risks. In this study, we integrated high-throughput metagenomic sequencing with conventional cultivation approaches to comprehensively characterize the microbial communities, pathogenic potential, antibiotic resistance genes (ARGs), and virulence factor genes (VFGs) in ballast water and corresponding harbor water samples collected from Qingdao Port. Metagenomic analysis revealed distinct microbial diversities, with 2,071 and 1,434 species identified in ballast and harbor water, respectively. Both environments were dominated by Proteobacteria, Bacteroidota, and Actinobacteriota, consistent with culture-based findings that showed Proteobacteria as the predominant phylum (68% in ballast water). Metagenome-assembled genomes (MAGs) analysis generated 500 species-level MAGs from ballast water (331 novel), further underscoring high microbial novelty. Pathogen screening at the assembly level identified 142 potential pathogens in ballast water, with Pseudomonas aeruginosa, Vibrio parahaemolyticus, and Vibrio cholerae exhibiting high detection frequencies (65.5%, 56.4%, and 49.1%, respectively). Functional profiling identified 111 ARG types and 215 VFG types in ballast water, compared with 55 ARG types and 110 VFG types in harbor water, with dominant VFGs involved in adherence, motility, and immune modulation—traits potentially enhancing colonization and survival in new environments. Our findings highlight that ballast water from Qingdao Port carries a substantial reservoir of diverse, potentially pathogenic microorganisms equipped with resistance and virulence determinants, emphasizing the need for integrated monitoring strategies that combine cultivation, metagenomics, and risk assessment to inform ballast water management and international biosecurity policies.

Objective:This study demonstrated that transcutaneous electrical nerve stimulation (TENS) and its induced fecal microbiota transplantation (FMT) could treat anterior talo-fibular ligament (ATFL) injury rat and modify the intestinal microbiota via the gut-joint axis. Methods:An ATFL injury model was duplicated and treated with low, medium, or high-intensity of TENS. After 1, 2, and 3 weeks of TENS treatment, the improvements and the expression levels of NOD2/IL-6/NF-κB/BMP-2/TGF-β were measured. The intestinal microbiota was analyzed via 16S rDNA sequencing. After FMT which induced by TENS, the improvement of ATFL injury rat was analyzed. Results:After TENS treatment, compared with the model control group, the bio-mechanical, gait, bone mineral density (BMD), etc. parameters were elevated in the TENS groups (p < 0.05); the expression of NOD2/IL-6 decreased and the BMP-2/TGF-β increased in the TENS groups (p < 0.05). The intestinal microbiota was altered, including increases in the abundances of Erysipelotrichaceae, Lachnospira, Eubacterium, Phascolarctobacterium, and Alloprevotella. After FMT, similar improvements were found in ATFL injury rats. Conclusion:TENS ameliorated ATFL injury rat by regulating the NOD2/IL-6/NF-κB/BMP-2/TGF-β and changed the intestinal microbiota through the gut-joint axis. Dominant intestinal microbiota was associated with FMT and could improve ATFL injury rat.

Natural polysaccharides are essential macromolecules found in both plant and animal kingdoms, playing significant roles in food, medicine, biomaterials, and packaging. Deep eutectic solvents (DES), formed through hydrogen-bond interactions, offer simple synthesis, eco-friendliness, and lower melting points. This review demonstrates DES-mediated multi-modal extraction techniques (ultrasound, microwave, pressure, etc.) achieves 1.45-4.30-fold higher polysaccharide yields versus hot water extraction. Specifically, wolfberry fruits showed 2.44-fold increase, Ganoderma lucidum exhibited 4.30-fold enhancement, and Camellia oleifera fruit shells demonstrated 1.45-fold improvement. DES modifies key structural parameters including molecular weight reduction, degree of esterification decrease, and morphology changes (smaller particle sizes with enhanced porosity). Enhanced bioactivities include: DPPH center dot scavenging capacity increased 15-30 %, anti-glycation inhibition reached 87.63 % versus 71.52 % for water extraction in Polygonatum odoratum, and superior alpha-glucosidase inhibition for diabetes management in multiple sources. This article reviews DES origins, synthesis, synergy with multi-modal techniques, and supports further research and industrial implementation.

High-entropy materials (HEMs) hold great promise for electrocatalytic applications owing to their tunable electronic structures, particularly in complex reactions involving multiple intermediates. However, HEMs prepared by conventional methods often suffer from a trade-off between site diversity and reaction specificity, resulting in limited catalytic efficiency. In this study, we address this challenge by developing a Janus-type high-entropy alloy/high-entropy layered hydroxide (HEA/HELH) heterostructure with synthetically controllable interfaces via Fe3+-mediated topochemical reconstruction with precisely controlled reconstruction times of 30-120min. Leveraging the Fe3+/Fe2+ redox-driven carbon-confined galvanic replacement reaction, we achieved epitaxial interfacial growth and formed a built-in electric field (BIEF) with a work-function difference of 0.54eV, which was associated with a 240mV decrease in the calculated potential-determining step of HMFOR. The optimized HEA/HELH heterostructure delivers a Faradaic efficiency of 93.5% for FDCA at 1.55V vs. RHE and retains more than 90% of its current response over 100h, comparing favorably with recently reported HMFOR electrocatalysts. Mechanistic studies suggest that interfacial charge redistribution associated with the BIEF facilitates the formation and utilization of high-valence Co/Ni/Fe species, thereby promoting cascade oxidation from HMF to FDCA. Furthermore, the controllable HEA/HELH demonstrates significant potential for broader adaptability in multistep electrocatalytic oxidation. This work provides an interfacial engineering strategy for designing high-entropy catalysts for electrocatalytic biomass valorization.

Microbiologically influenced corrosion (MIC) is a significant cause of metal infrastructure degradation in marine environments and industrial systems, resulting in substantial economic costs and safety hazards. This review focuses on the critical role of biofilms in MIC, discussing biofilm formation, the interactions among microbial communities within biofilms, and the impact of biofilm microenvironment on the corrosion process. First, two primary models of biofilm development, the five-stage model and the three-stage model, which delineate the progression from bacterial attachment to maturation and dispersion of biofilms, are reviewed. Following this, the proteins and genes involved in biofilm formation are highlighted, including surface proteins, synthesis of extracellular polymeric substances (EPSs), and the role of quorum-sensing systems in regulating biofilm development. The synergistic and competitive interactions, chemical signaling, electron transfer, and gene transfer among microorganisms within biofilms, which are crucial for the stability and functional performance of the entire community, are reviewed. Chemical signaling and electron transfer are particularly important for microbial metabolism and the corrosion process. Furthermore, the review investigates the impact of the biofilm microenvironment on corrosion, including oxygen concentration gradients, acidic microzones, the role of EPSs, metabolic products, and enzymes, as well as electron carriers within biofilms. These factors interact to create complex corrosion mechanisms that significantly influence the localized corrosion of metals. In addition, this review analyzes parameters within biofilms for MIC modeling, such as biofilm thickness, density, and porosity; microbial growth rates; and biofilm detachment parameters, which are vital for accurately predicting the MIC process. Finally, the review summarizes various techniques for measuring the biofilm microenvironment, including bioanalytical techniques, radiation detection techniques, microscopic analysis, and biosensing technology, providing essential tools for studying microbial-metal interactions.

AimThis study revealed the mechanism of transcutaneous electrical nerve stimulation (TENS) for improving the calcaneofibular ligament (CFL) injury rats by regulating the intestinal microbiota.MethodsAfter 1, 2, and 3 weeks of TENS treatment, the improvement of CFL injury rats model and the expressions of IL-1β/NF-κB/IL-17 signaling pathway were measured. Then the intestinal microbiota was analyzed by 16S rDNA sequencing and its functions related to improve CFL injury rat were analyzed.ResultsTENS could improved the athletic ability of CFL injury rats and reduced the expressions of IL-1β/NF-κB by regulating the IL-17 signaling pathway. By 16S rDNA sequencing analysis, the TENS treatment improved the intestinal dysbacteriosisof CFL injury rats and decrease pathogenic bacteria Ruminococcus and Dubosiella. The changed intestinal microbiota maybe relative with the ankle injury, whereas the increase in probiotics (Bacteroides and Lactobacillus) was relative with anti-inflammation.ConclusionTENS could down-regulate the expressions of IL-1β/NF-κB to improve CFL injury rat. TENS could change the intestinal microbiota of CFL rats and the changed bacteria whose function related to anti-inflammation could improve CFL rat. The intestinal microbiota could become a potential treatment for CFL injury.

Primary Biliary Cholangitis (PBC) is a chronic autoimmune liver disease characterized by immune-mediated destruction of intrahepatic bile ducts. This review synthesizes current knowledge on the critical role of innate immunity, specifically involving cholangiocytes, bile components, and associated immune cells. Cholangiocytes function not only as passive targets but also as active immunomodulators through mechanisms including Toll-like receptor (TLR) signaling, antigen presentation, and immune cell recruitment. Dysregulated bile acid signaling via receptors like TGR5 disrupts immune homeostasis, while apoptosis of biliary epithelial cells releases antigens (e.g., PDC-E2), triggering aberrant innate and adaptive immune responses. Innate lymphoid cells (ILCs), natural killer (NK) cells, and macrophages exhibit altered frequencies and functions in PBC, driving chronic inflammation and fibrosis through cytokine cascades (e.g., IL-17, IFNγ) and interactions within the gut-liver axis. Furthermore, biliary microbiota dysbiosis exacerbates disease by promoting bacterial translocation, modifying bile acid metabolism, and activating innate immune pathways. Current clinical management with ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) primarily addresses cholestasis. However, the immunomodulatory effects of these agents remain constrained. Targeted therapeutic strategies addressing innate immune pathways-exemplified by RIPK2 (Receptor Interacting Serine/Threonine Kinase 2) inhibition, IL-1 blockade(Canakinumab), and T cell immunoglobulin mucin domain-containing protein 3 (TIM-3) modulation-alongside cell-based interventions such as mesenchymal stem cell therapy, demonstrate considerable therapeutic potential. Advancing these modalities necessitates multidisciplinary integration to facilitate clinical translation. Additionally, Prognostic indices like the neutrophil-to-lymphocyte ratio (NLR) and monocyte-to-lymphocyte ratio (MLR) reflect systemic inflammation and correlate with disease progression. Achieving therapeutic precision requires deeper elucidation of the gut-biliary-immune axis, trained immunity mechanisms, and cholangiocyte senescence, paving the way for targeted interventions in PBC. Establishing a comprehensive treatment burden assessment system is imperative to facilitate the transition from investigational platforms to clinical care.

We have constructed a simple, enzyme-free and label-free detection method for bacterial DNA. First, bacterial DNA (T) is designed as a trigger to make the designed metastable hairpin probes P1, P2, P3 (carrying DNA silver nanoclusters sequences) autonomously cross-open to achieve catalytic self-assembly, inducing a three-way DNA junction formation through the catalyzed hairpin self-assembly (CHA) mode. Then, G-rich sequences are intro-duced to form DNA silver nanoclusters G quadruplex (DNA-AgNCs-G quadruplex), and a strong fluorescence signal can be collected under the action of silver nitrate and sodium borohydride solutions. Through the fluo-rescent reporter of DNA silver nanoclusters (DNA-AgNCs) and the amplification of CHA, we successfully detected target DNA at concentrations as low as 19.95 fM. Compared with the constructed acyclic system, the sensitivity of this cyclic system is improved about three orders of magnitude. Moreover, this recycling system achieves good selectivity for mismatched target DNA and excellent recovery rate in practical samples. Therefore, bacterial DNA analysis based on target-aided self-assembly cycle amplification coupled with DNA-AgNCs/three-way DNA junction is successfully developed, promising its great application in biological sensing.

Here a colorimetric sensing platform for sulfate-reducing bacterial DNA analysis was described by using a catalytic hemin/G-quadruplex loaded rigid DNA triangle assembly. This two-dimensional rigid DNA triangle structure was assembled by target bacterial DNA and three hairpin beacon probes. As three tips of hairpin probes carry specific recognition sites for G-quadruplex formation, target bacterial DNA trigger the opening of hairpin probes, not only forming a steady rigid DNA triangle but also activating the hemin/G-quadruplex horseradish peroxidase mimicking DNAzyme. The resultant hemin/G-quadruplex loaded rigid DNA triangle assembly catalyzes a colorimetric reaction with the signal intensity correlated to target concentrations, achieving target bacterial DNA detection with a detection limit as low as 23.99 fM. We further analyzed actual bacteria with this system, by acquiring bacterial DNA including bacteria-specific sequences with polymerase chain reaction (PCR), with the detection limit down to 1 cfu/mL. The system shows good selectivity for the target and resistance to interference, highly stable performance for serum samples application, showing great potential for application in the fields of genetic analysis, environmental monitoring, and medical testing.

The bacterial colonization of surfaces and subsequent biofilm formation are a great threat in medical therapy and clinical diagnosis. The complex internal structure and composition sets an enormous obstacle for the localization and removal of biofilms. In this study, we proposed a novel biofilm-targeted nanocontainer with successive responsive property toward pH and ATP for precise localization and simultaneous bacterial eradication, with an acidic and adenosine triphosphate (ATP)-rich micro environment within biofilms, formed due to the accumulation of fatty acids and ATP in the three-dimensional enclosed structure, integrated as two successive indicators to improve the precision of biofilm identification and removal. The biofilm-targeted nano container was composed of a ATP-responsive zeolitic imidazolate framework-90 (ZIF-90) core loaded with Rho 6G and doxorubicin hydrochloride (DOX) encapsulated in the pH-responsive amorphous calcium carbonate/poly(acrylic acid) (ACC/PAA) shell. In the presence of biofilms, the ACC/PAA shell and ZIF-90 core were successively degraded by the accumulated H+ and ATP within biofilms, resulting in the release of fluorescence indicators and antimicrobial agents. On the other hand, to meet the application requirements of different biofilm scenarios, the pH response ability of the nanocontainers could be adjusted by changing the metallic ions (Ni2+, Zn2+, and Cu2+) doped into the structure of the ACC/PAA shell. Owing to excellent water dispersion of the pH/ATP double-responsive ZIF-90@Zn-ACC/PAA nanocontainer, precise localization and simultaneous bacterial eradication was successfully realized via a simple spray process. The successive pH/ ATP two-step unlocking processes endowed the nanocontainers high precision for localization and simultaneous eradication of biofilms, which made the proposed nanocontainers high promising in food safety and medical treatment.

Carbon source starvation can promote steel corrosion in the presence of a pure culture through extracellular electron transfer (EET). However, the impact of carbon source starvation on corrosion induced by mixed strains is still unknown. This work investigated the impact of carbon source starvation on EH40 steel corrosion in the presence of Desulfovibrio vulgaris and Pseudomonas aeruginosa, typical species of sulfate- and nitrate-reducing bacteria. It was found that the impact of carbon source starvation on corrosion depended on nitrate addition. When nitrate (5 g∙L−1 NaNO3) was not added, the corrosion was promoted by carbon source starvation. However, the corrosion was initially promoted by carbon source starvation, but later inhibited with nitrate addition. The corrosion behaviors in different systems were closely related to different numbers of the strains in biofilms and their metabolic activities, and the mechanisms were revealed.

Introduction. Osteoporosis (OP) is characterized by microstructural degeneration of bone tissue, low bone mass, bone fragility and even brittle fracture (osteoporotic fracture, OPF). OP and OPF are common and there are many disadvantages to the current medications for OP/OPF. Osteoking is a traditional Chinese medicine (TCM) originating from the Yi nationality (Yunnan, China) that has been used to treat bone diseases for decades.Hypothesis/Gap Statement. This study will reveal the changes in the intestinal microbiota of OP rats after 70 days of osteoking treatment.Method. With duplication of sham and OP rats, eight groups were established, with six rats in each group. The intestinal microbiotas were analysed by 16S rDNA sequencing.Results. The results showed that osteoking changed the intestinal microbiota of sham rats and OP rats. The mechanism by which osteoking improves OP is related to the functions of the intestinal microbiota. After 70 days of treatment with osteoking, the contents of Pseudonocardia, Pedomicrobium, Variovorax, Niastella and Actinosynnema were decreased in OP rats. The functions of the above intestinal microbiota related to iron metabolism affected calcifediol and 25(OH)D, and measuring these bone metabolic indicators is required for further study.Conclusion. Osteoking changes the intestinal microbiota to improve OP, and further study which reveals these intestinal microbiota and mechanism is needed.