Bacterial infection presents formidable challenges that frequently culminate in the malfunction of metal implants.Traditional surface treatment methods struggle to effectively achieve controllable management of bacter...Bacterial infection presents formidable challenges that frequently culminate in the malfunction of metal implants.Traditional surface treatment methods struggle to effectively achieve controllable management of bacterial infections associated with metal implants.To effectively enhance the antibacterial capabilities and preventing bacterial adhesion,electroactive materials have emerged as a groundbreaking strategy for surface modification of metal.By responding to external signals,the electroactive materials can improve antibacterial properties and resistance to bacterial adhesion on the implant surface through harnessing the electrostatic interaction of charges,ion release,oxidation of reactive oxygen species(ROS),electron transfer,and the involvement of cellular immunity.This review delves into the principles of how electroactive materials confer implants with antibacterial properties and antibacterial adhesion,while also summarizing the latest research breakthroughs in their application for surface modification.These strategies successfully strike a balance between the antibacterial and the antimicrobial performance of the implant surface.Lastly,the review examines the limitations and ongoing challenges faced by electroactive material modification technology in implant applications,and sketches out the future trajectory and potential innovative avenues in this promising field.展开更多
Oral ulcers may greatly diminish patient life quality and potentially result in malignant transformations.Using gels or films as pseudomembrane barriers is an effective method for promoting ulcer healing.However,these...Oral ulcers may greatly diminish patient life quality and potentially result in malignant transformations.Using gels or films as pseudomembrane barriers is an effective method for promoting ulcer healing.However,these pseudomembranes face challenges such as saliva flushing,dynamic changes,and the presence of abundant microorganisms in the complex oral environment.Herein,we developed an injectable,photoinduction,in situ-enhanceable oral ulcer repair hydrogel(named as GIL2)by incorporating dynamic phenylboronic acid ester bonds and imidazole ions into a methacrylated gelatin matrix.GIL2 exhibited rapid gelation(3 s),low swelling properties(1.07 g/g),robust tensile strength(56.83 kPa)and high adhesive strength(63.38 kPa),allowing it to adhere effectively to the ulcer surface.Moreover,the GIL2 demonstrated intrinsic antibacterial and antioxidant qualities.Within a diabetic rat model for oral ulcers,GIL2 effectively eased oxidative stress and decreased the inflammation present in ulcerated wounds,thereby greatly hastening the healing process of these ulcers.Together,GIL2 hydrogel demonstrates remarkable adaptability within the oral milieu,revitalizing clinical strategy advancements for treating bacterialinfected oral ulcers.展开更多
This review systematically summarizes recent advancements in the design of antibacterial hydrogels and the surface-related factors influencing microbial adhesion to polymeric materials.Hydrogels,characterized by their...This review systematically summarizes recent advancements in the design of antibacterial hydrogels and the surface-related factors influencing microbial adhesion to polymeric materials.Hydrogels,characterized by their three-dimensional porous architecture and ultra-high water content,serve as ideal platforms for incorporating antibacterial agents(e.g.,metal ions,natural polymers)through physical/chemical interactions,enabling sustained release and enhanced antibacterial efficacy.For traditional polymers,surface properties(e.g.,roughness,charge,superhydrophobicity,free energy,nanoforce gradients)play critical roles in microbial adhesion.Modifying the surface properties of polymers through surface treatment can regulate antibacterial performance.In particular,by referencing the micro/nanostructures found on natural surfaces such as lotus leaves and cicada wings,antibacterial surfaces with multiple superior functions can be fabricated.Collectively,these findings provide a theoretical basis for the rational design of multifunctional antibacterial materials,offering material-based solutions to address complex infection scenarios and advance infection management strategies.展开更多
Microorganisms are crucial for the breakdown of proteins and lipids in dry-fermented sausages and are intimately associated with the flavor profile of sausages.In this study,we used a mixed starter culture to ferment ...Microorganisms are crucial for the breakdown of proteins and lipids in dry-fermented sausages and are intimately associated with the flavor profile of sausages.In this study,we used a mixed starter culture to ferment sausages and investigated the flavor turnover.During the fermentation of salami,the data from free amino acids(FAAs),free fatty acids(FFAs)and volatile flavor substances were used to assess the quality of salami.At the end of fermentation,the total FAAs increased from 1171.32 to 4582.48 mg/kg in the control group and 5053.25 mg/kg in the experimental group.Additionally,following inoculation with the mixed starter culture,the levels of glutamic acid,lysine,methionine,valine and leucine were significantly higher(P<0.05)than those in the control group.Oleic acid(C_(18:1))and chondritic acid(C_(16:0))were the two most abundant FFAs in both salami samples with 45.86%and 26.07%on the 23^(th)day in mixed culture inoculated salami.The mixed starter inoculated group had significantly lower saturated fatty acids and higher percentage levels of monounsaturated fatty acids than the control group(P<0.05).In the volatile flavor substance analysis,a total of 61 volatile compounds were found.Ester compounds were progressively enriched with drying time,significantly increasing the flavor substances,like ethyl diphosgene,1-octen-3-ol,and 2,3-butanediol at P<0.05.The correlation analysis between the core flora and volatile flavor compounds during fermentation and maturation of salami indicates Lactobacillus sakei and Lactobacillus rhamnosus were significantly higher and positively correlated with the major volatile organic compounds,which are the key core microorganisms affecting the flavor quality of fermented sausages.展开更多
The shear adhesive strength at the clay‒metal interfaces serves as a critical parameter for evaluating the soil adhesion and metal interface mudding phenomena.However,its rapid determination remains challenging becaus...The shear adhesive strength at the clay‒metal interfaces serves as a critical parameter for evaluating the soil adhesion and metal interface mudding phenomena.However,its rapid determination remains challenging because of the demanding requirements for high-precision instrumentation and complex calibration procedures.In this study,an integrated framework was presented that combined physical experiments,theoretical approaches,and machine learning to enable the autonomous determination of the shear adhesive strength of soil under multiple influencing factors.We developed an improved particle swarm optimization-optimized ordinary kriging(IPOK)surrogate testing method to enhance the limited experimental datasets,and a lightweight residual neural network(RLNet)was then used for effective intra-and extra-domain predictions.A comprehensive model discussion,comparison,and interpretability analysis were conducted.The results from 64 physical experiments considering the consistency index,normal stress,clay content,rotation rate,and disc material effectively characterized the shear adhesion behaviour of kaolin.The IPOK surrogate experiments successfully replicated the physical data points while enriching the dataset details.The RLNet model trained with IPOK data achieved superior prediction performance,with a root mean square error of 7.491 and a determination coefficient of 0.927 in 16 orthogonal validation tests,and high similarity was attained between the predicted and measured values.A detailed model discussion analysis confirmed the superiority of the IPOK-RLNet framework.This methodology provides a cost-effective rapid analysis technique for assessing clay‒metal interface shear adhesion,significantly reducing laboratory testing requirements and experimental costs while increasing engineering efficiency.展开更多
As a specific spoilage organism of seafood under refrigerated temperature conditions,Shewanella spp.tend to form biofilms that exacerbate the occurrence of seafood spoilage.Biofilm-promoting factor A(BpfA)has been rep...As a specific spoilage organism of seafood under refrigerated temperature conditions,Shewanella spp.tend to form biofilms that exacerbate the occurrence of seafood spoilage.Biofilm-promoting factor A(BpfA)has been reported to promote the adhesion and biofilm formation of Shewanella spp.,but its role in adhesion and biofilm formation of S.putrefaciens under cold stress needs to be further investigated.To better comprehend the effect of BpfA on adhesion and biofilm formation of S.putrefaciens under cold stress(4℃),bacterial adhesion and biofilm phenotype of S.putrefaciens CN32 WT andΔbpfA at 4℃were analyzed and performed transcriptomics.The results showed that the deletion of bpfA had almost no effect on the growth of S.putrefaciens CN32 at 4℃,but weakened the unicellular adhesion capacity of S.putrefaciens CN32 and destabilized the stability of the multicellular adhesion layer.In addition,the biomass of the mature biofilm formed byΔbpfA was merely around 50%of that observed in the mature biofilm of S.putrefaciens CN32 WT,the average thickness and volume of the biofilm decreased by 18%and 27%,respectively,and the composition of the biofilm changed.Transcriptome analysis demonstrated that the deletion of bpfA led to differential expression of genes involved in metabolic pathways such as bacterial chemotaxis,two-component system,tyrosine metabolism,drug metabolism-other enzymes and biofilm formation-Vibrio cholerae,which in turn influenced bacterial adhesion and biofilm formation.Those results advance our acknowledgment of the character of BpfA on adhesion and biofilm formation of S.putrefaciens CN32,which contributes to understanding bacterial adhesion and the control of biofilm formation.展开更多
Objective:To explore the effects of Punica granatum L.(P.granatum,Shi Liu)seed in the management of peritoneal adhesions(PAs)in rats.Methods:The mature male rats were separated into the following groups,each containin...Objective:To explore the effects of Punica granatum L.(P.granatum,Shi Liu)seed in the management of peritoneal adhesions(PAs)in rats.Methods:The mature male rats were separated into the following groups,each containing six animals:a sham group without peritoneal adhesion induction,a negative control group,and four intervention groups with both peritoneal adhesion induction and administration of 2 mL of vehicle or 0.1%,0.3%,1%,or 3%w/v P.granatum seed Soxhlet(PSS).Peritoneal adhesions were assessed through macroscopic examination,transforming growth factor-β1(TGF-β1),vascular endothelial growth factor(VEGF),and inflammatory cytokine tumor necrosis factor-α(TNF-α)levels were evaluated using biochemical methods.Results:The findings revealed no notable differences in adhesin scores between the therapeutic and negative control groups,but PSS(1 and 3%w/v)significantly reduced TNF-α,VEGF,and TGF-β1 levels compared with those in the negative control group(all P<.01).Conclusion:The results indicate that PSS is a potential treatment option for intraperitoneal adhesions.展开更多
Natural product(NPT)derived from traditional Chinese medicine has a rich history as an integral part of Chinese healthcare for thousands of years.Recently,the application of NPT in sonodynamic antibacterial therapy(SD...Natural product(NPT)derived from traditional Chinese medicine has a rich history as an integral part of Chinese healthcare for thousands of years.Recently,the application of NPT in sonodynamic antibacterial therapy(SDAT)has emerged as a promising area of research.This perspective summarizes the recent NPT-based sonosensitizers in SDAT.Currently,common NPT-based sonosensitizers include curcumin,chlorophyll derivatives,hypericin,and berberine.Compared with other sonosensitizers,natural sources of NPT-based sonosensitizers with reactive oxide species production performance under ultrasound conditions,low biotoxicity,and other additional biological activity make them have application prospects in bacterial removal.Finally,the potential benefits and challenges of NPT-based nanosonosensitizers were also discussed.展开更多
Bio-upcycling is an emerging end-of-life strategy for the polymer waste treatment that uses the power of mi-croorganisms to biocatalyticaly convert the pre-treated polymer waste monomers into high-added materials.Poly...Bio-upcycling is an emerging end-of-life strategy for the polymer waste treatment that uses the power of mi-croorganisms to biocatalyticaly convert the pre-treated polymer waste monomers into high-added materials.Poly(ethylene terephthalate)(PET),one of the leading synthetic polyesters in the global polymer market,produced from petrol based feedstock,still has no completely green alternative to meet global demand.Therefore,putting the PET based waste into a circular loop has become one of the major challenges of plastic waste management.In that context,the present study addressed the conversion of PET containing hydrolysates collected after the thermal pretreatment into bacterial nanocellulose(BNC),nowadays one of the most promising biopolymers produced in a sustainable manner.After the optimization of the BNC production cultivated under different conditions in PET hydrolysates,in a static way,the optimal conditions(yield of 3.0 mg/ml)was applied for scaling up.To further open the applicative potential of the BNC produced from PET containing plastic waste,platinum nanoparticles were deposited onto BNC developing new catalyst active in the methanol oxidation re-action.In order to enhance BNC ability to support Pt nanoparticles,it was blended with poly(vinyl alcohol),PVA,producing new PVA/BNC composites,recognized as an improved solid support,rich in hydroxyl groups that serve as an anchor points to Pt deposition.Due to the enrichment of BNC by PVA,it was possible to prepare highly active Pt-based catalyst with only 3 wt% of loaded Pt,which significantly reduce the cost of catalyst production.The cost-effective catalyst was prepared using sodium boron hydride as a reducing agent associated with film casting and fully characterized using FTIR,TGA,XRD,XPS,TEM,SEM-EDX analysis and its potential was confirmed in methanol oxidation reaction.This study explored the circular pathway from PET plastic waste to BNC and further to its potential application in direct methanol fuel cell(DMFC).展开更多
The development of highly efficient and multifunctional nanozymes holds promise for addressing the challenges posed by drugresistant bacteria.Here,copper single-atom-loaded MoS_(2) nanozymes(CuSAs/MoS_(2))were develop...The development of highly efficient and multifunctional nanozymes holds promise for addressing the challenges posed by drugresistant bacteria.Here,copper single-atom-loaded MoS_(2) nanozymes(CuSAs/MoS_(2))were developed to effectively combat drug-resistant bacteria by synergistically integrating the triple strategies of oxidative damage,cuproptosis-like death and disruption of cell wall synthesis.Density functional theory revealed that each Cu center coordinated with three sulfur ligands,enhancing the adsorption of H_(2)O_(2),which reduced the activation energy of the key step by 17%,thereby improving peroxidase-like(PODlike)activity.The generation of reactive oxygen species in combination with CuSAs/MoS_(2) glutathione peroxidase-like(GSH-Px-like)for glutathione scavenging resulted in an imbalance in redox homeostasis within bacteria.CuSAs/MoS_(2),which act as nanopioneers,drive oxidative stress to initiate the process of cuproptosis-like death,leading to abnormal aggregation of lipoylated proteins and inactivation of iron-sulfur cluster proteins.Moreover,CuSAs/MoS_(2) inhibited the biosynthesis of the peptidoglycan synthesis precursors D-glutamate and m-diaminopimelic acid and disrupted the peptidoglycan cross-linking process mediated by penicillin-binding proteins,effectively blocking the compensatory cell wall remodeling pathway ofβ-lactam-resistant bacteria.Overall,CuSAs/MoS_(2) with multiple functions can not only efficiently kill bacteria but also decelerate the development of bacterial resistance to combat drug-resistant bacterial infections.展开更多
Systematic understanding of the interaction between cells and their microenvironment is of wide interest.To investigate this interaction,a flexible micropillar array device integrating dual functions of cell behavior ...Systematic understanding of the interaction between cells and their microenvironment is of wide interest.To investigate this interaction,a flexible micropillar array device integrating dual functions of cell behavior regulation and adhesion measurement is developed.Micropillar arrays with high and low densities are designed to explore the role of substrate topography in the behavior of human bone marrow mesenchymal stem cells.In addition,a method is established for quantifying weak cell adhesion forces on the basis of micropillar deflections.The results show that cell cytoplasmic adhesion is greater on a low-density micropillar array than that on a high-density array and is localized mainly in the perinuclear region of the cytoplasm rather than in pseudopods.It is also found that the micropillar array topography facilitates the oriented spreading of cell morphology and pseudopod formation,and a reduction in focal adhesion aggregation and F-actin polarization compared with a flat substrate.Notably,cells cultured on a low-density micropillar array exhibited a higher number of pseudopods,stronger adhesion forces,and greater stiffness compared with those on a high-density array.In summary,this work employs an adhesion force sensor,immunofluorescence staining,and atomic force microscopy to investigate the mechanical properties of cells and elucidate the mechanisms by which micropillar topographical cues regulate the adhesion of mesenchymal stem cells to the substrate.The micropillar array force sensor developed in this study provides an effective tool for simultaneously modulating cell behavior and quantifying adhesion forces,offering valuable insights for biomechanical research.展开更多
The effect of antibacterial adhesive on the biological corrosion resistance of mortar in seawater environment was studied by means of scanning electron microscope,thermogravimetric analysis,X-ray diffraction,Fourier t...The effect of antibacterial adhesive on the biological corrosion resistance of mortar in seawater environment was studied by means of scanning electron microscope,thermogravimetric analysis,X-ray diffraction,Fourier transform infrared spectroscopy,and ultra-depth microscope.The results show that the antibacterial adhesive can effectively inhibit the growth of sulfur-oxidizing bacteria in seawater,hinder their metabolism to produce biological sulfate,and reduce the formation of destructive product gypsum.The mineral composition and thermal analysis showed that the peak value of plaster diffraction peak and the mass loss of plaster dehydration in antibacterial adhesive group were significantly lower than those in blank group(without protective coating group).In addition,the electric flux of chloride ions(>400 C)in the blank group of mortar samples was higher than that in the antibacterial adhesive group(<200 C),indicating that the antibacterial adhesive can effectively reduce the permeability of chloride ions in mortar,and thus hinder the Cl-erosion in seawater.展开更多
BACKGROUND Edwardsiella tarda(E.tarda)belongs to the family Enterobacteriaceae and is generally seen to cause infections mainly in fish,but is also capable of infecting humans.Extraintestinal infections occur in patie...BACKGROUND Edwardsiella tarda(E.tarda)belongs to the family Enterobacteriaceae and is generally seen to cause infections mainly in fish,but is also capable of infecting humans.Extraintestinal infections occur in patients with certain risk factors,including immunocompromised status.We recently diagnosed a case of spontaneous bacterial peritonitis(SBP)due to E.tarda in an immuno-compromised dialysis patient.CASE SUMMARY Patient was a 55-year-old male,with a history of diabetic nephropathy being treated with hemodialysis three times a week.He was referred to our hospital due to an increased volume of ascites,and blood examination revealed increased inflammatory reaction.At our emergency department,he developed fever,disturbance of consciousness,abdominal distension,and abdomen-wide pain.In addition,a dialysis shunt was confirmed in his right forearm,and the shunt site showed no signs of inflammation.No wounds were confirmed on or in his body.A blood examination revealed increased values of white blood cells,C-reactive protein,and creatinine.Plain chest and abdominal computed tomography scanning revealed increased ascites volume.Abdominal paracentesis was performed and a Gram stain revealed Gramnegative bacillus.These findings prompted diagnosis of SBP.The patient was admitted and treated with cefmetazole,causing fever resolution and symptom improvements.Later,E.tarda was identified in ascites culture.The patient improved with decreased inflammatory response and was discharged on the 12th day of hospitalization.The antibiotic was terminated after 14 days of treatment.SBP in this case may have developed from chronic renal failure and diabetes mellitus.CONCLUSION We report the first known case of SBP due to E.tarda in an immuno-compromised dialysis patient.展开更多
Microscopy imaging is fundamental in analyzing bacterial morphology and dynamics,offering critical insights into bacterial physiology and pathogenicity.Image segmentation techniques enable quantitative analysis of bac...Microscopy imaging is fundamental in analyzing bacterial morphology and dynamics,offering critical insights into bacterial physiology and pathogenicity.Image segmentation techniques enable quantitative analysis of bacterial structures,facilitating precise measurement of morphological variations and population behaviors at single-cell resolution.This paper reviews advancements in bacterial image segmentation,emphasizing the shift from traditional thresholding and watershed methods to deep learning-driven approaches.Convolutional neural networks(CNNs),U-Net architectures,and three-dimensional(3D)frameworks excel at segmenting dense biofilms and resolving antibiotic-induced morphological changes.These methods combine automated feature extraction with physics-informed postprocessing.Despite progress,challenges persist in computational efficiency,cross-species generalizability,and integration with multimodal experimental workflows.Future progress will depend on improving model robustness across species and imaging modalities,integrating multimodal data for phenotype-function mapping,and developing standard pipelines that link computational tools with clinical diagnostics.These innovations will expand microbial phenotyping beyond structural analysis,enabling deeper insights into bacterial physiology and ecological interactions.展开更多
Stroke induces profound neuroinflammation and systemic immune dysregulation,including disturbances in gut homeostasis.Experimental evidence suggests that intestinal barrier permeability(IBP)and bacterial translocation...Stroke induces profound neuroinflammation and systemic immune dysregulation,including disturbances in gut homeostasis.Experimental evidence suggests that intestinal barrier permeability(IBP)and bacterial translocation(BT)critically influence stroke outcomes.However,biological variability among commonly used rodent substrains has received limited attention.In this pilot study,we compared poststroke immune responses in two Wistar rat substrains obtained from different suppliers:RccHan(Envigo)and RjHan(Janvier).Naive animals(n=4)and rats subjected to permanent cerebral ischemia(n=8 per substrain)were evaluated 72 h after middle cerebral artery occlusion and stratified according to the presence or absence of BT.Immune cell populations in blood and bone marrow were analyzed using flow cytometry,and leukocyte infiltration into ischemic brain tissue was quantified using immunohisto-chemistry.Differences were considered statistically significant when p<0.05.Both substrains developed significant infarcts and neurological deficits.RccHan rats exhibited larger infarct volumes and more extensive BT across multiple organs.In contrast,RjHan rats exhibited BT mainly confined to mesenteric lymph nodes but exhibited greater IBP.Although dissemination was broader in RccHan rats,overall bacterial burden was slightly lower compared with RjHan,and extraintestinal bacterial composition differed between groups.Particularly,RjHan rats exhibited stronger systemic and central immune activation,with significant alterations in lymphocyte and monocyte populations and enhanced granulocyte and T-cell infiltration within ischemic lesions.These findings demonstrate that substrain origin profoundly influences poststroke intestinal barrier integrity,bacterial dissemination,and immune responses considering substrain-related variability is essential to improve reproducibility and translational relevance in preclinical stroke research.展开更多
Background:The bacterial biofilm poses a significant challenge to traditional antibiotic therapy.There is a great need to develop novel antibiofilm agents combined with biofilm disrupting and bacteria-killing without ...Background:The bacterial biofilm poses a significant challenge to traditional antibiotic therapy.There is a great need to develop novel antibiofilm agents combined with biofilm disrupting and bacteria-killing without the dependence of antibiotic.Methods:Herein,we prepared ultrasound/magnetic field-responsive ferroferric oxide nanoparticles(Fe_(3)O_(4))/glucose oxidase microbubbles(FGMB)to form a cascade catalytic system for effective removing methicillin-resistant Staphylococcus aureus biofilms.FGMB were prepared through interfacial self-assembly of Fe_(3)O_(4) nanoparticles(NPs)and glucose oxidase(GOx)at the gas-liquid interface stabilized by surfactants.Under ultrasound/magnetic field stimulation,FGMB disrupted biofilm architecture through microbubble collapse-induced microjets and magnetically driven displacement.Simultaneously,ultrasound-triggered rupture of FGMB released GOx and Fe_(3)O_(4) NPs.Glucose can be oxidized by GOx to generate gluconic acid and hydrogen peroxide which was subsequently catalyzed into hydroxyl radicals by Fe_(3)O_(4) NPs,enabling chemical eradication of biofilm-embedded bacteria.Results:Optical microscopy images demonstrated that FGMB have spherical structure with average size of approximately 17μm.FGMB showed a 65.4%decrease in methicillin-resistant Staphylococcus aureus biofilm biomass and 1.1 log bacterial inactivation efficiency(91.2%),suggesting effective biofilm elimination.In vitro experimental results also indicate that FGMB have good biocompatibility.Conclusion:This antibiofilm strategy integrated dual modes of physical biofilm disruption with chemical bacteria-killing shows great potential as a versatile,non-resistant strategy for bacterial biofilm elimination.展开更多
Methicillin-resistant Staphylococcus aureus(MRSA) causes widespread infections and poses serious public health concerns. Its high level of resistance to multiple antibiotics has garnered growing interest in identifyin...Methicillin-resistant Staphylococcus aureus(MRSA) causes widespread infections and poses serious public health concerns. Its high level of resistance to multiple antibiotics has garnered growing interest in identifying and applying novel antibacterial compounds derived from natural sources. In this study, we purified a biosurfactant(BS) from Bacillus rugosus HH2 to develop a natural antibacterial agent. This agent was then reinforced with chitooligosaccharide(COS) and polyvinyl alcohol(PVA) to create a hydrogel that promoted healing in MRSA-infected wounds. The COS/PVA/BS hydrogel was readily fabricated via the freeze-thaw method and demonstrated excellent mechanical strength, biological activity,and biocompatibility. In vitro assays confirmed that the hydrogel significantly enhanced the proliferation, migration, angiogenesis, and extracellular matrix deposition of fibroblasts,keratinocytes, and endothelial cells. Moreover, it exhibited strong bacteriostatic and bactericidal activities against MRSA, along with potent antibiofilm activity and inhibition of virulence factors relevant to MRSA-induced wound infections. Its anti-virulence effects have been linked to the downregulation of quorum sensing and virulence-related genes in MRSA. In an in vivo model of MRSA-induced infection, the COS/PVA/BS hydrogel significantly accelerated wound healing and markedly reduced the MRSA burden. Immunofluorescence staining confirmed enhanced neovascularization and regulated macrophage responses,underscoring the angiogenic and immunomodulatory effects of the hydrogel. Overall,the COS/PVA/BS hydrogel represents a promising therapeutic strategy for addressing antibiotic-resistant bacterial infections and promoting wound repair, supported by the use of common raw materials, a simple fabrication process, and high-yield production of natural antibacterial agents.展开更多
In this paper,our main goal is to study a new mathematical model which describes the frictional contact between a foundation and a deformable body which is composed of viscoplastic materials and where the process is c...In this paper,our main goal is to study a new mathematical model which describes the frictional contact between a foundation and a deformable body which is composed of viscoplastic materials and where the process is considered dynamic.The contact condition on the normal plane is modeled by a unilateral constraint condition for a version of normal velocity in which the memory effect and the adhesion are considered.On the tangential plane a frictional contact condition is governed by the Clarke subdifferential of a locally Lipschitz function,and the evolution of the bonding field is governed by an ordinary differential equation.We formulate this problem as coupled system that consists of two ordinary differential equations and a variational-hemivariational inequality.Then,the existence,uniqueness and continuous dependence of the solution on the data results concerning the abstract system are established.Finally,we use the abstract results to show the existence and uniqueness of the solution to the contact problem.展开更多
Bacterial growth requires strategic allocation of limited intracellular resources,especially under cold stress,where stabilized messenger ribonucleic acid(mRNA)secondary structures slow translation by impairing riboso...Bacterial growth requires strategic allocation of limited intracellular resources,especially under cold stress,where stabilized messenger ribonucleic acid(mRNA)secondary structures slow translation by impairing ribosome binding.Escherichia coli(E.coli)counters this bottleneck by inducing the cold-shock protein A(CspA),an RNA chaperone that remodels inhibitory structures.However,synthesizing CspA diverts biosynthetic capacity from ribosome production and metabolism,creating a fundamental resource-allocation trade-off.In this work,we develop a dynamical model capturing the interplay between metabolic precursors,ribosomes,and CspA,and use it to examine how growth and allocation patterns shift with temperature.Steady-state analysis shows that each temperature produces a distinct,locally stable equilibrium,illustrating how cold environments reshape cellular priorities.We then formulate growth maximization as an optimal control problem,solved using Pontryagin’s Maximum Principle,to identify allocation strategies that balance translation maintenance and biomass production.The resulting optimal strategies exhibit bang-bang and singular structures,highlighting periods of extreme and intermediate allocation that reflect how bacteria might dynamically prioritize competing cellular functions.These control patterns converge to their corresponding steady state allocations and provide quantitative insight into optimal resource management under cold stress.These results provide a quantitative optimal-control framework linking RNA-level cold-shock adaptation to proteome allocation and growth,yielding testable predictions for how bacteria balance translational maintenance and biomass production at suboptimal temperatures.展开更多
Soil bacteria are integral to ecosystem functioning,significantly contributing to nutrients cycling and organic matter decomposition,and enhancing soil structure.This research considered the composition and dynamics o...Soil bacteria are integral to ecosystem functioning,significantly contributing to nutrients cycling and organic matter decomposition,and enhancing soil structure.This research considered the composition and dynamics of soil bacterial communities under different vegetation types(native Quercus brantii Lindl.and Amygdalus scoparia Spach,and non-native Pinus eldarica Medw.and Cupressus arizonica Greene.)in Zagros mountain area of Iran.This study involved a comparative analysis of soil culturable heterotrophic bacterial communities in spring(wet season)and summer(dry season)to clarify the effects of seasonal changes and vegetation on the dynamics of soil microorganisms.Soil samples were randomly collected under the canopies of various tree species and a control area,yielding a total of 48 composite samples analyzed for bacterial composition.Results indicated that 11 Gram-negative(e.g.,Citrobacter freundii,Enterobacter cloacae,Escherichia coli,Klebsiella oxytoca,Klebsiella pneumoniae,etc.)and 2 Gram-positive(Staphylococcus epidermidis and Staphylococcus aureus)bacteria were identified,showing significant seasonal variation.Specifically,53.85%of bacterial species were common to both seasons,with notable shifts in community composition observed between spring and summer,highlighting a higher abundance of Gram-negative species in spring.Bacterial community structure was significantly influenced by vegetation type,with various tree species shaping distinct microbial assemblages.Moreover,Pearson's correlations revealed that soil properties,particularly pH,phosphorus,and moisture content,were critical drivers of bacterial diversity and abundance.Our findings underscore the dynamic nature of soil bacterial communities in response to seasonal and vegetation changes,emphasizing the importance of repeated temporal sampling for accurate assessments of microbial diversity.Understanding these microbial dynamics is essential for improving soil management strategies and enhancing ecosystem resilience,particularly in arid and semi-arid areas where environmental fluctuations play a pivotal role.This research not only confirms our hypotheses but also enhances our understanding of soil biogeochemical processes and informs future vegetation management practices.展开更多
基金financially supported by the National Key Research and Development Program of China(Nos.2022YFC2406000 and 2021YFC2400402)the National Natural Science Foundation of China(Nos.52101285,51932002,U21A2055 and U22A20160)
文摘Bacterial infection presents formidable challenges that frequently culminate in the malfunction of metal implants.Traditional surface treatment methods struggle to effectively achieve controllable management of bacterial infections associated with metal implants.To effectively enhance the antibacterial capabilities and preventing bacterial adhesion,electroactive materials have emerged as a groundbreaking strategy for surface modification of metal.By responding to external signals,the electroactive materials can improve antibacterial properties and resistance to bacterial adhesion on the implant surface through harnessing the electrostatic interaction of charges,ion release,oxidation of reactive oxygen species(ROS),electron transfer,and the involvement of cellular immunity.This review delves into the principles of how electroactive materials confer implants with antibacterial properties and antibacterial adhesion,while also summarizing the latest research breakthroughs in their application for surface modification.These strategies successfully strike a balance between the antibacterial and the antimicrobial performance of the implant surface.Lastly,the review examines the limitations and ongoing challenges faced by electroactive material modification technology in implant applications,and sketches out the future trajectory and potential innovative avenues in this promising field.
基金funding from the National Natural Science Foundation of China(Nos.82071170 and 82371016)the Zhejiang Provincial Science and Technology Project for Public Welfare(No.LGF21H140004).
文摘Oral ulcers may greatly diminish patient life quality and potentially result in malignant transformations.Using gels or films as pseudomembrane barriers is an effective method for promoting ulcer healing.However,these pseudomembranes face challenges such as saliva flushing,dynamic changes,and the presence of abundant microorganisms in the complex oral environment.Herein,we developed an injectable,photoinduction,in situ-enhanceable oral ulcer repair hydrogel(named as GIL2)by incorporating dynamic phenylboronic acid ester bonds and imidazole ions into a methacrylated gelatin matrix.GIL2 exhibited rapid gelation(3 s),low swelling properties(1.07 g/g),robust tensile strength(56.83 kPa)and high adhesive strength(63.38 kPa),allowing it to adhere effectively to the ulcer surface.Moreover,the GIL2 demonstrated intrinsic antibacterial and antioxidant qualities.Within a diabetic rat model for oral ulcers,GIL2 effectively eased oxidative stress and decreased the inflammation present in ulcerated wounds,thereby greatly hastening the healing process of these ulcers.Together,GIL2 hydrogel demonstrates remarkable adaptability within the oral milieu,revitalizing clinical strategy advancements for treating bacterialinfected oral ulcers.
基金supported by Science and Technology Plan of Luzhou under Grant No.2024JYJ039.
文摘This review systematically summarizes recent advancements in the design of antibacterial hydrogels and the surface-related factors influencing microbial adhesion to polymeric materials.Hydrogels,characterized by their three-dimensional porous architecture and ultra-high water content,serve as ideal platforms for incorporating antibacterial agents(e.g.,metal ions,natural polymers)through physical/chemical interactions,enabling sustained release and enhanced antibacterial efficacy.For traditional polymers,surface properties(e.g.,roughness,charge,superhydrophobicity,free energy,nanoforce gradients)play critical roles in microbial adhesion.Modifying the surface properties of polymers through surface treatment can regulate antibacterial performance.In particular,by referencing the micro/nanostructures found on natural surfaces such as lotus leaves and cicada wings,antibacterial surfaces with multiple superior functions can be fabricated.Collectively,these findings provide a theoretical basis for the rational design of multifunctional antibacterial materials,offering material-based solutions to address complex infection scenarios and advance infection management strategies.
基金supported by the National Key Research and Development Program of China(2023YFD2100104)Henan Provincial Major Science and Technology Special Fund(231100110400).
文摘Microorganisms are crucial for the breakdown of proteins and lipids in dry-fermented sausages and are intimately associated with the flavor profile of sausages.In this study,we used a mixed starter culture to ferment sausages and investigated the flavor turnover.During the fermentation of salami,the data from free amino acids(FAAs),free fatty acids(FFAs)and volatile flavor substances were used to assess the quality of salami.At the end of fermentation,the total FAAs increased from 1171.32 to 4582.48 mg/kg in the control group and 5053.25 mg/kg in the experimental group.Additionally,following inoculation with the mixed starter culture,the levels of glutamic acid,lysine,methionine,valine and leucine were significantly higher(P<0.05)than those in the control group.Oleic acid(C_(18:1))and chondritic acid(C_(16:0))were the two most abundant FFAs in both salami samples with 45.86%and 26.07%on the 23^(th)day in mixed culture inoculated salami.The mixed starter inoculated group had significantly lower saturated fatty acids and higher percentage levels of monounsaturated fatty acids than the control group(P<0.05).In the volatile flavor substance analysis,a total of 61 volatile compounds were found.Ester compounds were progressively enriched with drying time,significantly increasing the flavor substances,like ethyl diphosgene,1-octen-3-ol,and 2,3-butanediol at P<0.05.The correlation analysis between the core flora and volatile flavor compounds during fermentation and maturation of salami indicates Lactobacillus sakei and Lactobacillus rhamnosus were significantly higher and positively correlated with the major volatile organic compounds,which are the key core microorganisms affecting the flavor quality of fermented sausages.
基金financial support pro-vided by National Natural Science Foundation of China(Grant No.52178402).
文摘The shear adhesive strength at the clay‒metal interfaces serves as a critical parameter for evaluating the soil adhesion and metal interface mudding phenomena.However,its rapid determination remains challenging because of the demanding requirements for high-precision instrumentation and complex calibration procedures.In this study,an integrated framework was presented that combined physical experiments,theoretical approaches,and machine learning to enable the autonomous determination of the shear adhesive strength of soil under multiple influencing factors.We developed an improved particle swarm optimization-optimized ordinary kriging(IPOK)surrogate testing method to enhance the limited experimental datasets,and a lightweight residual neural network(RLNet)was then used for effective intra-and extra-domain predictions.A comprehensive model discussion,comparison,and interpretability analysis were conducted.The results from 64 physical experiments considering the consistency index,normal stress,clay content,rotation rate,and disc material effectively characterized the shear adhesion behaviour of kaolin.The IPOK surrogate experiments successfully replicated the physical data points while enriching the dataset details.The RLNet model trained with IPOK data achieved superior prediction performance,with a root mean square error of 7.491 and a determination coefficient of 0.927 in 16 orthogonal validation tests,and high similarity was attained between the predicted and measured values.A detailed model discussion analysis confirmed the superiority of the IPOK-RLNet framework.This methodology provides a cost-effective rapid analysis technique for assessing clay‒metal interface shear adhesion,significantly reducing laboratory testing requirements and experimental costs while increasing engineering efficiency.
基金funded by the National Natural Science Foundation of China(32472401).
文摘As a specific spoilage organism of seafood under refrigerated temperature conditions,Shewanella spp.tend to form biofilms that exacerbate the occurrence of seafood spoilage.Biofilm-promoting factor A(BpfA)has been reported to promote the adhesion and biofilm formation of Shewanella spp.,but its role in adhesion and biofilm formation of S.putrefaciens under cold stress needs to be further investigated.To better comprehend the effect of BpfA on adhesion and biofilm formation of S.putrefaciens under cold stress(4℃),bacterial adhesion and biofilm phenotype of S.putrefaciens CN32 WT andΔbpfA at 4℃were analyzed and performed transcriptomics.The results showed that the deletion of bpfA had almost no effect on the growth of S.putrefaciens CN32 at 4℃,but weakened the unicellular adhesion capacity of S.putrefaciens CN32 and destabilized the stability of the multicellular adhesion layer.In addition,the biomass of the mature biofilm formed byΔbpfA was merely around 50%of that observed in the mature biofilm of S.putrefaciens CN32 WT,the average thickness and volume of the biofilm decreased by 18%and 27%,respectively,and the composition of the biofilm changed.Transcriptome analysis demonstrated that the deletion of bpfA led to differential expression of genes involved in metabolic pathways such as bacterial chemotaxis,two-component system,tyrosine metabolism,drug metabolism-other enzymes and biofilm formation-Vibrio cholerae,which in turn influenced bacterial adhesion and biofilm formation.Those results advance our acknowledgment of the character of BpfA on adhesion and biofilm formation of S.putrefaciens CN32,which contributes to understanding bacterial adhesion and the control of biofilm formation.
基金financially supported by Mashhad University of Medical Sciences(961726).
文摘Objective:To explore the effects of Punica granatum L.(P.granatum,Shi Liu)seed in the management of peritoneal adhesions(PAs)in rats.Methods:The mature male rats were separated into the following groups,each containing six animals:a sham group without peritoneal adhesion induction,a negative control group,and four intervention groups with both peritoneal adhesion induction and administration of 2 mL of vehicle or 0.1%,0.3%,1%,or 3%w/v P.granatum seed Soxhlet(PSS).Peritoneal adhesions were assessed through macroscopic examination,transforming growth factor-β1(TGF-β1),vascular endothelial growth factor(VEGF),and inflammatory cytokine tumor necrosis factor-α(TNF-α)levels were evaluated using biochemical methods.Results:The findings revealed no notable differences in adhesin scores between the therapeutic and negative control groups,but PSS(1 and 3%w/v)significantly reduced TNF-α,VEGF,and TGF-β1 levels compared with those in the negative control group(all P<.01).Conclusion:The results indicate that PSS is a potential treatment option for intraperitoneal adhesions.
基金supported by the Innovation and Entrepreneurship Training Program for College Students(X2025102911746,X2025102910483).
文摘Natural product(NPT)derived from traditional Chinese medicine has a rich history as an integral part of Chinese healthcare for thousands of years.Recently,the application of NPT in sonodynamic antibacterial therapy(SDAT)has emerged as a promising area of research.This perspective summarizes the recent NPT-based sonosensitizers in SDAT.Currently,common NPT-based sonosensitizers include curcumin,chlorophyll derivatives,hypericin,and berberine.Compared with other sonosensitizers,natural sources of NPT-based sonosensitizers with reactive oxide species production performance under ultrasound conditions,low biotoxicity,and other additional biological activity make them have application prospects in bacterial removal.Finally,the potential benefits and challenges of NPT-based nanosonosensitizers were also discussed.
基金financially supported from the European Union’s Horizon Europe EIC Pathfinder programme under agreement No 101046758(EcoPlastiC)by the Ministry of Science,Innovation and Technological Development of the Republic of Serbia(Agreement No.451-03-66/2024-03/200042 and No.451-03-66/2024-03/2000026)by the Science Fund of the Republic of Serbia under the grant No 7739802.
文摘Bio-upcycling is an emerging end-of-life strategy for the polymer waste treatment that uses the power of mi-croorganisms to biocatalyticaly convert the pre-treated polymer waste monomers into high-added materials.Poly(ethylene terephthalate)(PET),one of the leading synthetic polyesters in the global polymer market,produced from petrol based feedstock,still has no completely green alternative to meet global demand.Therefore,putting the PET based waste into a circular loop has become one of the major challenges of plastic waste management.In that context,the present study addressed the conversion of PET containing hydrolysates collected after the thermal pretreatment into bacterial nanocellulose(BNC),nowadays one of the most promising biopolymers produced in a sustainable manner.After the optimization of the BNC production cultivated under different conditions in PET hydrolysates,in a static way,the optimal conditions(yield of 3.0 mg/ml)was applied for scaling up.To further open the applicative potential of the BNC produced from PET containing plastic waste,platinum nanoparticles were deposited onto BNC developing new catalyst active in the methanol oxidation re-action.In order to enhance BNC ability to support Pt nanoparticles,it was blended with poly(vinyl alcohol),PVA,producing new PVA/BNC composites,recognized as an improved solid support,rich in hydroxyl groups that serve as an anchor points to Pt deposition.Due to the enrichment of BNC by PVA,it was possible to prepare highly active Pt-based catalyst with only 3 wt% of loaded Pt,which significantly reduce the cost of catalyst production.The cost-effective catalyst was prepared using sodium boron hydride as a reducing agent associated with film casting and fully characterized using FTIR,TGA,XRD,XPS,TEM,SEM-EDX analysis and its potential was confirmed in methanol oxidation reaction.This study explored the circular pathway from PET plastic waste to BNC and further to its potential application in direct methanol fuel cell(DMFC).
基金supported by the National Natural Science Foundation of China(82372552)the Excellent Youth of Natural Science Research Projects in Anhui Province Universities(2023AH030060)+1 种基金Anhui Provincial Natural Science Foundation(2408085Y016)Anhui Province Excellent Research and Innovation Team Project(2024AH010013)。
文摘The development of highly efficient and multifunctional nanozymes holds promise for addressing the challenges posed by drugresistant bacteria.Here,copper single-atom-loaded MoS_(2) nanozymes(CuSAs/MoS_(2))were developed to effectively combat drug-resistant bacteria by synergistically integrating the triple strategies of oxidative damage,cuproptosis-like death and disruption of cell wall synthesis.Density functional theory revealed that each Cu center coordinated with three sulfur ligands,enhancing the adsorption of H_(2)O_(2),which reduced the activation energy of the key step by 17%,thereby improving peroxidase-like(PODlike)activity.The generation of reactive oxygen species in combination with CuSAs/MoS_(2) glutathione peroxidase-like(GSH-Px-like)for glutathione scavenging resulted in an imbalance in redox homeostasis within bacteria.CuSAs/MoS_(2),which act as nanopioneers,drive oxidative stress to initiate the process of cuproptosis-like death,leading to abnormal aggregation of lipoylated proteins and inactivation of iron-sulfur cluster proteins.Moreover,CuSAs/MoS_(2) inhibited the biosynthesis of the peptidoglycan synthesis precursors D-glutamate and m-diaminopimelic acid and disrupted the peptidoglycan cross-linking process mediated by penicillin-binding proteins,effectively blocking the compensatory cell wall remodeling pathway ofβ-lactam-resistant bacteria.Overall,CuSAs/MoS_(2) with multiple functions can not only efficiently kill bacteria but also decelerate the development of bacterial resistance to combat drug-resistant bacterial infections.
基金supported by the National Natural Science Foundation of China(Grant No.32371471).
文摘Systematic understanding of the interaction between cells and their microenvironment is of wide interest.To investigate this interaction,a flexible micropillar array device integrating dual functions of cell behavior regulation and adhesion measurement is developed.Micropillar arrays with high and low densities are designed to explore the role of substrate topography in the behavior of human bone marrow mesenchymal stem cells.In addition,a method is established for quantifying weak cell adhesion forces on the basis of micropillar deflections.The results show that cell cytoplasmic adhesion is greater on a low-density micropillar array than that on a high-density array and is localized mainly in the perinuclear region of the cytoplasm rather than in pseudopods.It is also found that the micropillar array topography facilitates the oriented spreading of cell morphology and pseudopod formation,and a reduction in focal adhesion aggregation and F-actin polarization compared with a flat substrate.Notably,cells cultured on a low-density micropillar array exhibited a higher number of pseudopods,stronger adhesion forces,and greater stiffness compared with those on a high-density array.In summary,this work employs an adhesion force sensor,immunofluorescence staining,and atomic force microscopy to investigate the mechanical properties of cells and elucidate the mechanisms by which micropillar topographical cues regulate the adhesion of mesenchymal stem cells to the substrate.The micropillar array force sensor developed in this study provides an effective tool for simultaneously modulating cell behavior and quantifying adhesion forces,offering valuable insights for biomechanical research.
基金Funded by the National Natural Science Foundation of China(Nos.52278269,52278268,52178264)Tianjin Outstanding Young Scholars Science Fund Project(No.22JCJQJC00020)Key Project of Tianjin Natural Science Foundation(No.23JCZDJC00430)。
文摘The effect of antibacterial adhesive on the biological corrosion resistance of mortar in seawater environment was studied by means of scanning electron microscope,thermogravimetric analysis,X-ray diffraction,Fourier transform infrared spectroscopy,and ultra-depth microscope.The results show that the antibacterial adhesive can effectively inhibit the growth of sulfur-oxidizing bacteria in seawater,hinder their metabolism to produce biological sulfate,and reduce the formation of destructive product gypsum.The mineral composition and thermal analysis showed that the peak value of plaster diffraction peak and the mass loss of plaster dehydration in antibacterial adhesive group were significantly lower than those in blank group(without protective coating group).In addition,the electric flux of chloride ions(>400 C)in the blank group of mortar samples was higher than that in the antibacterial adhesive group(<200 C),indicating that the antibacterial adhesive can effectively reduce the permeability of chloride ions in mortar,and thus hinder the Cl-erosion in seawater.
文摘BACKGROUND Edwardsiella tarda(E.tarda)belongs to the family Enterobacteriaceae and is generally seen to cause infections mainly in fish,but is also capable of infecting humans.Extraintestinal infections occur in patients with certain risk factors,including immunocompromised status.We recently diagnosed a case of spontaneous bacterial peritonitis(SBP)due to E.tarda in an immuno-compromised dialysis patient.CASE SUMMARY Patient was a 55-year-old male,with a history of diabetic nephropathy being treated with hemodialysis three times a week.He was referred to our hospital due to an increased volume of ascites,and blood examination revealed increased inflammatory reaction.At our emergency department,he developed fever,disturbance of consciousness,abdominal distension,and abdomen-wide pain.In addition,a dialysis shunt was confirmed in his right forearm,and the shunt site showed no signs of inflammation.No wounds were confirmed on or in his body.A blood examination revealed increased values of white blood cells,C-reactive protein,and creatinine.Plain chest and abdominal computed tomography scanning revealed increased ascites volume.Abdominal paracentesis was performed and a Gram stain revealed Gramnegative bacillus.These findings prompted diagnosis of SBP.The patient was admitted and treated with cefmetazole,causing fever resolution and symptom improvements.Later,E.tarda was identified in ascites culture.The patient improved with decreased inflammatory response and was discharged on the 12th day of hospitalization.The antibiotic was terminated after 14 days of treatment.SBP in this case may have developed from chronic renal failure and diabetes mellitus.CONCLUSION We report the first known case of SBP due to E.tarda in an immuno-compromised dialysis patient.
基金financially supported by the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2022WNLOKF009)the National Natural Science Foundation of China(No.62475216)+2 种基金the Key Research and Development Program of Shaanxi(No.2024GH-ZDXM-37)the Fujian Provincial Natural Science Foundation of China(No.2024J01060)the Startup Program of XMU,and the Fundamental Research Funds for the Central Universities.
文摘Microscopy imaging is fundamental in analyzing bacterial morphology and dynamics,offering critical insights into bacterial physiology and pathogenicity.Image segmentation techniques enable quantitative analysis of bacterial structures,facilitating precise measurement of morphological variations and population behaviors at single-cell resolution.This paper reviews advancements in bacterial image segmentation,emphasizing the shift from traditional thresholding and watershed methods to deep learning-driven approaches.Convolutional neural networks(CNNs),U-Net architectures,and three-dimensional(3D)frameworks excel at segmenting dense biofilms and resolving antibiotic-induced morphological changes.These methods combine automated feature extraction with physics-informed postprocessing.Despite progress,challenges persist in computational efficiency,cross-species generalizability,and integration with multimodal experimental workflows.Future progress will depend on improving model robustness across species and imaging modalities,integrating multimodal data for phenotype-function mapping,and developing standard pipelines that link computational tools with clinical diagnostics.These innovations will expand microbial phenotyping beyond structural analysis,enabling deeper insights into bacterial physiology and ecological interactions.
基金Leducq Trans-Atlantic Network of Excellence,Grant/Award Number:TNE-21CVD04Spanish Ministry of Science and Innovation,Grant/Award Number:PID2020-117765RB-I00 and PID2022-140616OB-I00+1 种基金Instituto de Salud Carlos Ⅲ,European Development Regional Fund,RICORS-ICTUS Grant/Award Number:RD21/0006/0001the FORTALECE program. Grant/Award Number:FORT23/00023。
文摘Stroke induces profound neuroinflammation and systemic immune dysregulation,including disturbances in gut homeostasis.Experimental evidence suggests that intestinal barrier permeability(IBP)and bacterial translocation(BT)critically influence stroke outcomes.However,biological variability among commonly used rodent substrains has received limited attention.In this pilot study,we compared poststroke immune responses in two Wistar rat substrains obtained from different suppliers:RccHan(Envigo)and RjHan(Janvier).Naive animals(n=4)and rats subjected to permanent cerebral ischemia(n=8 per substrain)were evaluated 72 h after middle cerebral artery occlusion and stratified according to the presence or absence of BT.Immune cell populations in blood and bone marrow were analyzed using flow cytometry,and leukocyte infiltration into ischemic brain tissue was quantified using immunohisto-chemistry.Differences were considered statistically significant when p<0.05.Both substrains developed significant infarcts and neurological deficits.RccHan rats exhibited larger infarct volumes and more extensive BT across multiple organs.In contrast,RjHan rats exhibited BT mainly confined to mesenteric lymph nodes but exhibited greater IBP.Although dissemination was broader in RccHan rats,overall bacterial burden was slightly lower compared with RjHan,and extraintestinal bacterial composition differed between groups.Particularly,RjHan rats exhibited stronger systemic and central immune activation,with significant alterations in lymphocyte and monocyte populations and enhanced granulocyte and T-cell infiltration within ischemic lesions.These findings demonstrate that substrain origin profoundly influences poststroke intestinal barrier integrity,bacterial dissemination,and immune responses considering substrain-related variability is essential to improve reproducibility and translational relevance in preclinical stroke research.
基金supported by the National Natural Science Foundation of China(22375101)the Natural Science of Colleges and Universities in Jiangsu Province(24KJB430027).
文摘Background:The bacterial biofilm poses a significant challenge to traditional antibiotic therapy.There is a great need to develop novel antibiofilm agents combined with biofilm disrupting and bacteria-killing without the dependence of antibiotic.Methods:Herein,we prepared ultrasound/magnetic field-responsive ferroferric oxide nanoparticles(Fe_(3)O_(4))/glucose oxidase microbubbles(FGMB)to form a cascade catalytic system for effective removing methicillin-resistant Staphylococcus aureus biofilms.FGMB were prepared through interfacial self-assembly of Fe_(3)O_(4) nanoparticles(NPs)and glucose oxidase(GOx)at the gas-liquid interface stabilized by surfactants.Under ultrasound/magnetic field stimulation,FGMB disrupted biofilm architecture through microbubble collapse-induced microjets and magnetically driven displacement.Simultaneously,ultrasound-triggered rupture of FGMB released GOx and Fe_(3)O_(4) NPs.Glucose can be oxidized by GOx to generate gluconic acid and hydrogen peroxide which was subsequently catalyzed into hydroxyl radicals by Fe_(3)O_(4) NPs,enabling chemical eradication of biofilm-embedded bacteria.Results:Optical microscopy images demonstrated that FGMB have spherical structure with average size of approximately 17μm.FGMB showed a 65.4%decrease in methicillin-resistant Staphylococcus aureus biofilm biomass and 1.1 log bacterial inactivation efficiency(91.2%),suggesting effective biofilm elimination.In vitro experimental results also indicate that FGMB have good biocompatibility.Conclusion:This antibiofilm strategy integrated dual modes of physical biofilm disruption with chemical bacteria-killing shows great potential as a versatile,non-resistant strategy for bacterial biofilm elimination.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education (RS-2021-NR060118,RS-2024-00408404, and RS-2025-00555808)supported by the Korea Institute of Marine Science&Technology Promotion (KIMST)funded by the Ministry of Oceans and Fisheries (RS-2024-00404977)。
文摘Methicillin-resistant Staphylococcus aureus(MRSA) causes widespread infections and poses serious public health concerns. Its high level of resistance to multiple antibiotics has garnered growing interest in identifying and applying novel antibacterial compounds derived from natural sources. In this study, we purified a biosurfactant(BS) from Bacillus rugosus HH2 to develop a natural antibacterial agent. This agent was then reinforced with chitooligosaccharide(COS) and polyvinyl alcohol(PVA) to create a hydrogel that promoted healing in MRSA-infected wounds. The COS/PVA/BS hydrogel was readily fabricated via the freeze-thaw method and demonstrated excellent mechanical strength, biological activity,and biocompatibility. In vitro assays confirmed that the hydrogel significantly enhanced the proliferation, migration, angiogenesis, and extracellular matrix deposition of fibroblasts,keratinocytes, and endothelial cells. Moreover, it exhibited strong bacteriostatic and bactericidal activities against MRSA, along with potent antibiofilm activity and inhibition of virulence factors relevant to MRSA-induced wound infections. Its anti-virulence effects have been linked to the downregulation of quorum sensing and virulence-related genes in MRSA. In an in vivo model of MRSA-induced infection, the COS/PVA/BS hydrogel significantly accelerated wound healing and markedly reduced the MRSA burden. Immunofluorescence staining confirmed enhanced neovascularization and regulated macrophage responses,underscoring the angiogenic and immunomodulatory effects of the hydrogel. Overall,the COS/PVA/BS hydrogel represents a promising therapeutic strategy for addressing antibiotic-resistant bacterial infections and promoting wound repair, supported by the use of common raw materials, a simple fabrication process, and high-yield production of natural antibacterial agents.
基金supported by the NSF of Shanxi(202303021221168)the Industry-university-research project of Shanxi Datong University(2022CXY10,2022CXY13).
文摘In this paper,our main goal is to study a new mathematical model which describes the frictional contact between a foundation and a deformable body which is composed of viscoplastic materials and where the process is considered dynamic.The contact condition on the normal plane is modeled by a unilateral constraint condition for a version of normal velocity in which the memory effect and the adhesion are considered.On the tangential plane a frictional contact condition is governed by the Clarke subdifferential of a locally Lipschitz function,and the evolution of the bonding field is governed by an ordinary differential equation.We formulate this problem as coupled system that consists of two ordinary differential equations and a variational-hemivariational inequality.Then,the existence,uniqueness and continuous dependence of the solution on the data results concerning the abstract system are established.Finally,we use the abstract results to show the existence and uniqueness of the solution to the contact problem.
基金supported by NASA Oklahoma Established Program to Stimulate Competitive Research(EPSCoR)Infrastructure Development,“Machine Learning Ocean World Biosignature Detection from Mass Spec,”(PI:Brett McKinney),Grant No.80NSSC24M0109Tandy School of Computer Science,The University of Tulsa.
文摘Bacterial growth requires strategic allocation of limited intracellular resources,especially under cold stress,where stabilized messenger ribonucleic acid(mRNA)secondary structures slow translation by impairing ribosome binding.Escherichia coli(E.coli)counters this bottleneck by inducing the cold-shock protein A(CspA),an RNA chaperone that remodels inhibitory structures.However,synthesizing CspA diverts biosynthetic capacity from ribosome production and metabolism,creating a fundamental resource-allocation trade-off.In this work,we develop a dynamical model capturing the interplay between metabolic precursors,ribosomes,and CspA,and use it to examine how growth and allocation patterns shift with temperature.Steady-state analysis shows that each temperature produces a distinct,locally stable equilibrium,illustrating how cold environments reshape cellular priorities.We then formulate growth maximization as an optimal control problem,solved using Pontryagin’s Maximum Principle,to identify allocation strategies that balance translation maintenance and biomass production.The resulting optimal strategies exhibit bang-bang and singular structures,highlighting periods of extreme and intermediate allocation that reflect how bacteria might dynamically prioritize competing cellular functions.These control patterns converge to their corresponding steady state allocations and provide quantitative insight into optimal resource management under cold stress.These results provide a quantitative optimal-control framework linking RNA-level cold-shock adaptation to proteome allocation and growth,yielding testable predictions for how bacteria balance translational maintenance and biomass production at suboptimal temperatures.
文摘Soil bacteria are integral to ecosystem functioning,significantly contributing to nutrients cycling and organic matter decomposition,and enhancing soil structure.This research considered the composition and dynamics of soil bacterial communities under different vegetation types(native Quercus brantii Lindl.and Amygdalus scoparia Spach,and non-native Pinus eldarica Medw.and Cupressus arizonica Greene.)in Zagros mountain area of Iran.This study involved a comparative analysis of soil culturable heterotrophic bacterial communities in spring(wet season)and summer(dry season)to clarify the effects of seasonal changes and vegetation on the dynamics of soil microorganisms.Soil samples were randomly collected under the canopies of various tree species and a control area,yielding a total of 48 composite samples analyzed for bacterial composition.Results indicated that 11 Gram-negative(e.g.,Citrobacter freundii,Enterobacter cloacae,Escherichia coli,Klebsiella oxytoca,Klebsiella pneumoniae,etc.)and 2 Gram-positive(Staphylococcus epidermidis and Staphylococcus aureus)bacteria were identified,showing significant seasonal variation.Specifically,53.85%of bacterial species were common to both seasons,with notable shifts in community composition observed between spring and summer,highlighting a higher abundance of Gram-negative species in spring.Bacterial community structure was significantly influenced by vegetation type,with various tree species shaping distinct microbial assemblages.Moreover,Pearson's correlations revealed that soil properties,particularly pH,phosphorus,and moisture content,were critical drivers of bacterial diversity and abundance.Our findings underscore the dynamic nature of soil bacterial communities in response to seasonal and vegetation changes,emphasizing the importance of repeated temporal sampling for accurate assessments of microbial diversity.Understanding these microbial dynamics is essential for improving soil management strategies and enhancing ecosystem resilience,particularly in arid and semi-arid areas where environmental fluctuations play a pivotal role.This research not only confirms our hypotheses but also enhances our understanding of soil biogeochemical processes and informs future vegetation management practices.
