Search Results (4,580)

Bovine Viral Diarrhea Virus (BVDV) is a globally important cattle pathogen causing substantial economic losses. In Kazakhstan, BVDV’s epidemiological status remains poorly characterized due to the absence of systematic surveillance. We carried out a cross-sectional study of cattle herds across Kazakhstan, using ELISA to detect anti-BVDV antibodies and RT-PCR to identify active infections. Positive samples underwent sequencing for phylogenetic analysis of circulating strains. Additionally, a standard reference serum panel was developed to measure virus neutralization titers (ND₅₀) and to evaluate cross-neutralization with Border Disease virus (BDV). Antibodies against BVDV were prevalent, with seropositivity ranging from 28.89% to 96.13% across surveyed regions. Active BVDV infection was confirmed by RT-PCR in 17 animals. Phylogenetic analysis with 2 samples from Mangystau region classified the virus as BVDV2 genotype. The reference serum panel exhibited high neutralizing titers ND₅₀ up to 1:286 against the local BVDV-1 isolate. Notably, these sera also neutralized BDV, albeit at lower titers ND₅₀ 1:45. These findings provide crucial baseline epidemiological data and enhanced diagnostic tools for BVDV in Kazakhstan. They highlight the need for improved surveillance and will inform strategic control measures against this economically significant cattle disease. Full article

Electrochemical CO₂ reduction reaction (CO₂RR) is a key technology for achieving carbon neutrality and efficient utilization of renewable energy, capable of converting CO₂ into high-value-added carbon-based fuels and chemicals. Copper (Cu)-based catalysts have attracted significant attention due to their unique performance in generating multi-carbon (C₂₊) products such as ethylene and ethanol; however, there are still many controversies regarding their complex reaction mechanisms, active sites, and the dynamic evolution of intermediates. In situ Raman spectroscopy, with its high surface sensitivity, applicability in aqueous environments, and precise detection of molecular vibration modes, has become a powerful tool for studying the structural evolution of Cu catalysts and key reaction intermediates during CO₂RR. This article reviews the principles of electrochemical in situ Raman spectroscopy and its latest developments in the study of CO₂RR on Cu-based catalysts, focusing on its applications in monitoring the dynamic structural changes of the catalyst surface (such as Cu⁺, Cu⁰, and Cu²⁺ oxide species) and identifying key reaction intermediates (such as *CO, *OCCO(*O=C-C=O), *COOH, etc.). Numerous studies have shown that Cu-based oxide precursors undergo rapid reduction and surface reconstruction under CO₂RR conditions, resulting in metallic Cu nanoclusters with unique crystal facets and particle size distributions. These oxide-derived active sites are considered crucial for achieving high selectivity toward C₂₊ products. Time-resolved Raman spectroscopy and surface-enhanced Raman scattering (SERS) techniques have further revealed the dynamic characteristics of local pH changes at the electrode/electrolyte interface and the adsorption behavior of intermediates, providing molecular-level insights into the mechanisms of selectivity control in CO₂RR. However, technical challenges such as weak signal intensity, laser-induced damage, and background fluorescence interference, and opportunities such as coupling high-precision confocal Raman technology with in situ X-ray absorption spectroscopy or synchrotron radiation Fourier transform infrared spectroscopy in researching the mechanisms of CO₂RR are also put forward. Full article

Terminal forensics in large mobile networks is a vital activity for identifying compromised devices and analyzing malicious actions. In contrast, the study described here begins with the domain of terminal forensics as the primary focus, rather than the threat itself. This paper proposes a new multi-criteria decision-making (MCDM) model that integrates complex picture fuzzy sets (CPFS) with the combinative distance-based assessment (CODAS), referred to throughout as complex picture fuzzy CODAS (CPF-CODAS). The aim is to assist in forensic analysis for detecting mobile botnet command and control (C&C) systems. The CPF-CODAS model accounts for the uncertainty, hesitation, and complex numerical values involved in expert decision-making, using degrees of membership as positive, neutral, and negative values. An illustrative forensic case study is constructed where three mobile devices are evaluated by three cybersecurity professionals based on six key parameters related to botnet activity. The results demonstrate that the model can effectively distinguish suspicious devices and support the use of the CPF-CODAS approach in terminal forensics of mobile networks. The robustness, symmetry, and advantages of this model over existing MCDM methods are confirmed through sensitivity and comparison analyses. In conclusion, this paper introduces a novel probabilistic decision-support tool that digital forensic specialists can incorporate into their workflow to proactively identify and prevent actions of mobile botnet C&C servers. Full article

Background/Objectives: Urinary tract infections (UTIs) represent a major healthcare challenge due to antimicrobial resistance and biofilm formation. Our aim was to evaluate whether repurposed drugs and efflux pump inhibitors (EPIs) could provide alternative strategies by investigating their antibacterial, anti-biofilm, and resistance-modifying properties against Gram-negative uropathogens under varying pH conditions. Methods: Clinical isolates of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis were tested. Minimum inhibitory concentrations (MICs) of thioridazine (TZ), promethazine (PMZ), fluoxetine (Fx), sertraline (Sr), phenylalanine arginine β-naphthylamide (PAβN), carbonyl cyanide m-chlorophenyl hydrazone (CCCP), and the glutamine uptake inhibitor V9302 were determined at pH 5–8. Biofilm inhibition was assessed by crystal violet staining, while MIC reduction assays tested antibiotic combinations. Efflux pump inhibition was examined using an ethidium bromide accumulation assay. Results: TZ reduced biofilm formation in sensitive K. pneumoniae at all pH levels and enhanced ciprofloxacin (CIP) activity, whereas PMZ showed a weaker effect, limited mainly to neutral pH. Fx and Sr exhibited pH-dependent anti-biofilm activity, with Fx particularly effective against P. mirabilis at alkaline pH. PAβN consistently decreased biofilm biomass in both sensitive and resistant K. pneumoniae and, at pH 7–8, potentiated CIP activity with a 16-fold MIC reduction in the sensitive strain. CCCP showed pH-dependent activity, with stronger effects under acidic conditions, notably in E. coli and P. mirabilis. V9302 was a potent biofilm inhibitor in K. pneumoniae and resistant E. coli and interfered with efflux activity, showing strong effects in acidic environments. Conclusions: Repurposed drugs and EPIs may be useful as antibiotic adjuvants or biofilm inhibitors in treating resistant UTIs. Full article

Although transition metal catalysts have been used extensively for the polymerization of hydrocarbon monomers, several cationic aluminum catalysts have been also known to promote polymerization of ethylene and 1,3-butadiene. Transition-metal catalyzed polymerization generally proceeds via coordination and insertion of the monomer on one metal center. In contrast, in ethylene polymerization using aluminum catalysts, a bimolecular chain growth mechanism, including the reaction between neutral aluminum species and the monomer activated by cationic aluminum species, is proposed. Although previously reported aluminum catalysts are based on a monoaluminum complex, a dialuminum complex is expected to catalyze the polymerization more efficiently, considering the proposed mechanism. In this work, we found that a combination of diphosphines and MAO promotes polymerization of ethylene and 1,3-butadiene. The 1,4-bis(diphenylphosphino)butane (DPPB)/methylaluminoxane (MAO) system showed a much higher activity toward ethylene polymerization than other monophosphine or diphosphine/MAO systems. NMR analysis of a mixture of diphosphine and MAO indicates the formation of cationic dialuminum species in the presence of DPPB, whereas the formation of cationic monoaluminum species occurs in the presence of other diphosphines. The 2,2′-bis(diphenylphosphino)-1,1′-biphenyl (BIPHEP)/MAO system promoted 1,3-butadiene polymerization to give polybutadiene having a cis-1,4 selectivity of up to 93.8%. Full article

With the increasing demands of the grid on power electronic converters, active neutral-point-clamped (ANPC) converters have been widely adopted due to their flexible modulation strategies and wide-range power regulation capabilities. To address grid-integration testing requirements for ANPC converters, this paper comparatively studies three electromagnetic transient (EMT) modeling approaches: switch-state prediction method (SPM), associated discrete circuit (ADC), and time-averaged method (TAM). Steady-state and transient simulations reveal that the SPM model achieves the highest accuracy (error ≤ 0.018%), while the TAM-based switching function model optimizes the efficiency–accuracy trade-off with 6.4× speedup versus traditional methods and acceptable error (≤2.62%). Consequently, the TAM model is implemented in a real-time hardware-in-the-loop (HIL) platform. Validation under symmetrical/asymmetrical grid faults confirms both the model’s efficacy and the controller’s robust fault ride-through capability. Full article

Mpox virus (MPXV), a member of the Orthopoxvirus genus in the Poxviridae family, has long been endemic in Africa. The interaction between MPXV infection and peripheral immune responses is of great significance. However, the activation of signaling pathways and molecular changes in peripheral blood mononuclear cells (PBMCs) following MPXV infection remain poorly understood. This study evaluated the transcriptomic profiles of rabbit PBMCs during the mpox acute and recovery phases. The results showed that MPXV infection significantly altered the transcriptomic profiles of PBMCs. At 6 days post-infection, pathways related to pathogenic infection and IL-1 response were enriched, while at 14 days post-infection, the T cell receptor signaling pathway was enriched. During the mpox acute phase, inflammatory cytokines in serum such as IL-1α, IL-1β, IL-8, and IL-21 were upregulated, while MMP-9 and NCAM-1 were downregulated. In rabbits and rhesus monkeys, key genes upregulated in common during the mpox acute period were associated with the interferon pathway (e.g., the ISG15, OAS, and IFIT families), while downregulated genes were related to B-cell activation and differentiation (e.g., the MS4A1 and FCRL families). Additionally, rabbits developed protective immunity against reinfection, with neutralizing antibodies effectively activated. These findings provide insights into the molecular characteristics of PBMCs changes in in vivo models of MPXV infection, and offer references for the diagnosis, vaccine development, and therapeutic research of mpox. Full article

The activation of persulfate (PS) to oxidize and degrade 2,4-dichlorophenol (2,4-DCP) in aqueous solution represents a prevalent advanced oxidation technology. This study established a PS activation system using sulfide-modified nanoscale zero-valent iron supported on biochar (S-nZVI@BC). The optimal conditions included a PS:2,4-DCP mass ratio of 70:1 and S-nZVI@BC:PS of 1.5:1. The activator had excellent stability after being reused five times, which lead to high cost-effectiveness and sustainable usability. This system exhibited broad pH adaptability (3–11), with enhanced efficiency under acidic/neutral conditions. Chloride ion, nitrate, and carbonate had effects during the degradation. During the initial degradation phase, S-nZVI@BC played a primary role, with a greater contribution rate of adsorption than reduction. Fe⁰ played a dominant role in the PS activation process; reactive species—including HO•, SO₄•⁻, and O₂•⁻—were identified as key agents in subsequent degradation stages. The overall degradation processes comprised three distinct stages: dechlorination, ring-opening, and mineralization. Full article

Background: The quest for well-defined immunoadjuvants remains one of the highest priorities for the successful development of effective vaccines. Combination adjuvants, which are designed to integrate both the ability to activate a variety of immune mechanisms and synergistically improve the delivery of vaccine components, are well-positioned to address the unmet needs. The development of a preventive vaccine against hepatitis C virus (HCV)—a major public health concern—is a particular instance in which the choice of the immunoadjuvant is of utmost importance. Methods: We assembled a lipid A Toll-like receptor 4 (TLR4) agonist BECC438 and TLR7/8 agonist resiquimod (R848) on a polyphosphazene macromolecule (PCPP) to create a nanoscale immunoadjuvant-vaccine delivery system: PCPP-R+BECC438. This aqueous-based system was formulated with the HCV sE2 antigen, and the resulting vaccine candidate was evaluated in vivo for the ability to induce immune responses. Results: Co-assembly of adjuvants resulted in a visually clear aqueous system of nanoscale dimensions, monomodal size distribution, and entropy-driven interactions between components. Intramuscular immunization of mice with HCV sE2 antigen formulated in a polyphosphazene-based nano-system induced ten-fold higher IgG and IgG2a titers than the antigen adjuvanted with BECC438 alone. PCPP-R+BECC438 formulated HCV sE2 also produced statistically significant improvements in IgG2a/IgG1 ratio and more robust HCVpp neutralization ID₅₀ titers than control formulations. Conclusions: Polyphosphazene-assembled adjuvant nano-system promotes in vivo immune responses of enhanced quantity and quality of antibodies with increased potency of HCV neutralization. Full article

The effects of polymer concentration on rheology, surface tension, and electrical conductivity of polymer–surfactant mixtures are investigated experimentally. The polymer studied is a cationic quaternary ammonium salt of hydroxyethyl cellulose, and the surfactant used is anionic sodium lauryl sulfate. The polymer concentration is varied from 1000 to 4000 ppm, and the surfactant concentration varied from 0 to 500 ppm. Polymer concentration affects the properties of the mixtures substantially. At a given surfactant concentration, the consistency of the polymer–surfactant mixture rises sharply with the increase in polymer concentration. The mixture also becomes more shear-thinning with the increase in polymer concentration. The surface tension decreases substantially, and the electrical conductivity increases with the increase in polymer concentration at a fixed surfactant concentration. At a given polymer concentration, the consistency index generally exhibits a maximum and the surface tension exhibits a minimum at some intermediate surfactant concentration. With the increase in polymer concentration, the maximum in the consistency index and the minimum in surface tension shift to higher surfactant concentrations. Although the exact mechanisms are not clear at present, a possible explanation for the observed initial changes in rheological and surface-active properties of polymer–surfactant mixtures with the addition of surfactant is charge neutralization and entanglement of polymer chains. At high surfactant concentrations, recharging and disentanglement of polymer chains probably take place. Full article

Background/Objectives: Periradicular disease is largely microbial in origin. Even gutta-percha (GP) cones manufactured under aseptic conditions can acquire contaminants during handling or storage, undermining otherwise adequate canal preparation. To assess residual antimicrobial activity on GP cones after brief exposure to five endodontic disinfectants: sodium hypochlorite (NaOCl) 1%, 2.5%, 5.25%; chlorhexidine (CHX) 2%; and glutaraldehyde 2% against Enterococcus faecalis and Candida albicans. Methods: Standardized GP cones were dipped for 5–120 s, blotted on neutralizing gauze, and placed on agar inoculated with either organism. Using an agar diffusion approach, inhibition-zone diameters were recorded at 0, 24, and 48 h. Data were summarized using descriptive statistics (means, standard deviations, and 95% confidence intervals) for each disinfectant–dip-time combination. Results: By 24 h, inhibition zones were observed for most disinfectants; for C. albicans, glutaraldehyde 2% showed no measurable effect. At later time points, performance depended on both disinfectant and contact time. For E. faecalis, NaOCl 2.5% and 5.25% yielded the largest zones at 48 h (20–21 mm at 120 s), whereas NaOCl 1% was smaller (10 mm) and glutaraldehyde 2% modest (9 mm). For C. albicans, NaOCl 2.5% and CHX 2% were most effective at 48 h (17–19 mm at 120 s); NaOCl 5.25% was intermediate, NaOCl 1% weak, and glutaraldehyde 2% showed no measurable antifungal effect. Longer immersions (≥45 s) consistently increased inhibition zone diameters. Conclusions: Residual antimicrobial activity on GP cones depends on both the agent and the immersion time. For E. faecalis, higher concentration NaOCl produced the largest zones at short contact time, whereas for C. albicans, CHX 2% and NaOCl 2.5% provided the most reliable carryover. Selecting an appropriate concentration and allowing sufficient dip time may reduce reinfection risk at obturation. Full article

The ethanol oxidation reaction (EOR) is a key process for direct ethanol fuel cells (DEFCs), offering a high-energy-density and carbon-neutral pathway for sustainable energy conversion. However, the practical implementation of DEFCs is significantly hindered by the EOR due to its sluggish kinetics, complex multi-electron transfer pathways, and severe catalyst poisoning by carbonaceous intermediates. This review provides a comprehensive and mechanistically grounded overview of recent advances in EOR electrocatalysts, with a particular emphasis on the structure–activity relationships of noble metals (Pt, Pd, Rh, Au) and non-noble metals. The effects of catalyst composition, surface structure, and electronic configuration on C–C bond cleavage efficiency, product selectivity (C1 vs. C2), and CO tolerance are critically evaluated. Special attention is given to the mechanistic distinctions among different metal systems, highlighting how these factors influence reaction pathways and catalytic behavior. Key performance-enhancing strategies—including alloying, nanostructuring, surface defect engineering, and support interactions—are systematically discussed, with mechanistic insights supported by in situ characterization and theoretical modeling. Finally, this review identifies major challenges and emerging opportunities, outlining rational design principles for next-generation EOR catalysts that integrate high activity, durability, and scalability for real-world DEFC applications. Full article

Photodynamic inactivation and antimicrobial photodynamic therapy (PDI/APDT) based on the toxic properties of reactive oxygen species (ROS), which are generated by a number of photoexcited dyes, are promising for preventing and treating infections, especially those associated with drug-resistant pathogens. The negatively charged bacterial cell surface attracts polycationic photosensitizers, which contribute to the vulnerability of the bacterial plasma membrane to ROS. The integrity of the plasma membrane is critical for the viability of the bacterial cell. Polycationic phthalocyanines are regarded as promising photosensitizers due to their high quantum yields of ROS generation (mainly singlet oxygen), high extinction coefficients in the far-red spectral range, and low dark toxicity. For application in PDI/APDT, the wide range of possibilities of modifying the chemical structure of phthalocyanines is particularly valuable, especially by introducing various peripheral and non-peripheral substituents into the benzene rings. Depending on the type and location of such substituents, it is possible to obtain photosensitizers with different photophysical properties, photochemical activity, solubility in an aqueous medium, biocompatibility, and tropism for certain structures of photoinactivation targets. In this study, we tested novel water-soluble Zn (II) phthalocyanines bearing four 4-((diethylmethylammonium)methyl)phenoxy substituents with symmetric and asymmetric charge distributions for photodynamic antibacterial activity and compared them with those of water-soluble octacationic zinc octakis(cholinyl)phthalocyanine. The obtained results allow us to conclude that the studied tetracationic aryloxy-substituted Zn(II) phthalocyanines effectively bind to the oppositely charged cell wall of the Gram-negative bacteria E. coli. This finding is supported by data on bacteria’s zeta potential neutralization in the presence of phthalocyanine derivatives and fluorescence microscopy images of stained bacterial cells. Asymmetric substitution influences the aggregation and fluorescent characteristics but has little effect on the ability of the studied tetracationic phthalocyanines to sensitize the bioluminescent E. coli K12 TG1 strain. Both symmetric and asymmetric aryloxy-substituted phthalocyanines are no less effective in PDI than the water-soluble zinc octakis(cholinyl)phthalocyanine, a photosensitizer with proven antibacterial activity, and have significant potential for further studies as antibacterial photosensitizers. Full article

In the marine environment, plastic fragments are constantly engaged in a complex degradation process under exposure to various physical and chemical factors, one of which is ultraviolet (UV) radiation. These processes result in the formation of smaller micro- and nano-sized plastic particles, which are highly bioavailable to marine organisms. To clarify the toxicological effects of the exposure of degraded plastic on the marine organisms, the model used in this study was the Pacific mussel Mytilus trossulus and polymethylmethacrylate (PMMA), which is commonly found in marine debris. Using molecular and biochemical markers (DNA damage, lysosomal membrane stability, integral antiradical activity (IAA) of biological samples, and malondialdehyde (MDA) as a product of lipid peroxidation), the toxicity of pristine PMMA and photoaged (PMMA-UV) particles was assessed. Using Fourier transform infrared spectroscopy, the characteristics of the macromolecular changes in the chemical structure of PMMA-UV were obtained, with an oxidation index of 6.83 ± 0.46, compared to the pristine PMMA of 5.15 ± 0.54. Using a laser analyzer, the sizes of PMMA particles were determined, and it was found that after UV irradiation, the ratio of size groups changed—the proportion of particles with sizes of 500–1000 μm decreased, and the number of particles with sizes of 50–125 μm increased twofold. Analysis of mussel cell viability showed that after exposure to both types of PMMA microparticles, there was a decrease in the ability to retain neutral red dye in lysosomes: PMMA and PMMA-UV had a similar effect on hemocytes, reducing dye retention in cells to 55.2 ± 3.24% and 61.1 ± 1.99%, respectively. In gill and digestive gland cells, PMMA-UV particles reduced the stability of lysosomal membranes to a greater extent than PMMA. After PMMA and PMMA-UV particle exposure, the levels of DNA damage were as follows: in hemocytes, 10.1 ± 1.4% and 12.7 ± 0.8%, respectively; in gills, 7.8 ± 1.1% and 14.4 ± 2.9%, respectively; and in the digestive gland, 19.0 ± 1.3% and 21.9 ± 2.8%, respectively, according to the control values 3.6 ± 1.3%, 4.6 ± 1.1%, 5.1 ± 1.5%, respectively. According to the results of biochemical markers, the reaction of mussels to the presence of PMMA and PMMA-UV particles in the environment was tissue-specific: in the cells of the digestive gland, the level of IAA increased by 2 and 1.3 times compared to the control group of mussels (76.22 ± 6.77 nmol trolox/g wet weight and 52.43 ± 2.36 nmol trolox/g wet, respectively), while in the gill cells, the non-significant increase in antiradical activity was noted. An increase in MDA content was also observed in gill cells (255.8 ± 9.12 nmol MDA/g wet weight and 263.46 ± 9.45 nmol MDA/g wet weight, respectively) compared with the control group. This study showed that UV irradiation of PMMA microparticles increases their bioavailability and toxicity to M. trossulus. Full article

Mamba (Dendroaspis species) snakebites are critical medical emergencies across sub-Saharan Africa. Envenomings can result in the rapid onset of complex neurotoxic symptoms, often leading to high rates of mortality without timely intervention with antivenom. The ancestral state of mambas is the green coloured, forest dwelling type, with the tan/grey coloured, savannah dwelling D. polylepis (Black Mamba) representing a derived state both ecologically and morphologically. However, it has not been tested whether these changes are paralleled by changes in venom biochemistry or if there are differential molecular evolutionary patterns. To fill these knowledge gaps, this study evaluated the neurotoxic effects of all Dendroaspis species venoms using the chick biventer cervicis nerve-muscle preparation, assessed the neutralizing efficacy of three antivenoms commercially available in Africa, and reconstructed the molecular evolutionary history of the toxin types to ascertain whether some were unique to particular species. All Dendroaspis venoms demonstrated potent flaccid-paralysis due to postsynaptic neurotoxicity. The only exception was D. angusticeps venom, which conversely exhibited spastic-paralysis due to presynaptic/synaptic neurotoxicity characterised by potentiation of acetylcholine presynaptic release and sustained synaptic activity of this neurotransmitter. Antivenom efficacy varied significantly. All three antivenoms neutralized to some degree the flaccid-paralysis postsynaptic effects for all species, with D. viridis venom being the best neutralized, and this pattern extended to all the antivenoms. However, neutralisation of flaccid-paralysis postsynaptic effects unmasked spastic-paralysis presynaptic/synaptic neurotoxicity within non-angusticeps venoms. Spastic-paralysis presynaptic effects were poorly neutralized for all species by all antivenoms, consistent with prior clinical reports of poor neutralisation of spastic-paralytic effects. Geographic variation in D. polylepis venom was evident for the relative neutralisation of both spastic-paralysis presynaptic/synaptic and flaccid-paralysis postsynaptic/synaptic neurotoxic pathophysiological effects, with differential neutralization capabilities noted between the Kenyan and South African populations studied. Molecular phylogenetic analyses confirmed spastic-paralysis and flaccid- paralysis toxins to be a trait that emerged in the Dendroaspis last common ancestor, with all species sharing all toxin types. Therefore, differences in venoms’ pathophysiological actions between species are due to differential expression of toxin isoforms rather than the evolution of species-specific novel toxins. Our findings highlight the synergistic nature of flaccid-paralysis postsynaptic and spastic-paralysis presynaptic/synaptic toxins, while contributing significant clinical and evolutionary knowledge of Dendroaspis venoms. These data are crucial for the continued development of more effective therapeutic interventions to improve clinical outcomes and for evidence-based design of clinical management strategies for the envenomed patient. Full article