Search Results (1,224)

Acidithiobacillus caldus is perpetually exposed to multiple extreme environmental stresses. CsrA, functioning as a post-transcriptional regulator of physiological metabolism, acts as a differential modulator, facilitating more economical and efficient adaptation to extreme environments. The csrA expression recombinant strain was constructed in A. caldus MTH-04 by conjugative transfer technology pJD215. Physiological characterization revealed enhanced acid tolerance, significantly elongated flagella, elevated extracellular secretion, and altered biofilm composition. Notably, intracellular concentrations of free glutamate and aspartate increased to 24.18 mg/L and 16.07 mg/L, respectively. The secondary structure of CsrA protein was determined in vitro through circular dichroism spectroscopy and size-exclusion chromatography. Electrophoretic Mobility Shift Assay (EMSA) successfully demonstrated in vitro binding activity of CsrA to the rpoS leader mRNA. CsrA suppresses rpoS mRNA translation by competing with ribosomes for binding sites, thereby negatively regulating rpoS expression. Critical binding sites were further validated through site-directed mutagenesis. Through EMSA, RT-qPCR and the translation reporter system, it was also found that CsrA has a dual regulatory function for nearby flagella- and motility-related gene clusters (flgC, 07035, motD, 15040), which also implies the global regulatory role of CsrA. In summary, a potential overall post-transcriptional regulatory mechanism based on CsrA and rpoS by extremophile A. caldus was proposed. Finally, the efficiency of bioleaching application by csrA overexpression strain was improved by 20.81%. Full article

According to the World Health Organization, antibiotic research remains insufficient, emphasizing the urgent need for new active molecules, particularly against resistant bacteria. Based on known antibacterial scaffolds, new fluoroquinolone derivatives have been synthesized by our research group, including compound 7a, a difluoroboranyl-fluoroquinolone that previously demonstrated activity against sensitive strains. Methods: The minimum inhibitory (MIC) and bactericidal (MBC) concentrations of compound 7a were determined against Staphylococcus aureus, Klebsiella pneumoniae, and Escherichia coli. The selective development of ciprofloxacin-resistant S. aureus was induced by reseeding the isolate on seven consecutive days with an antibiotic concentration that was not capable of inhibiting its development. Pharmacokinetic and toxicological properties were predicted using SwissADME, Way2Drug, and molecular docking (AutoDock Vina). In vivo toxicity was evaluated in BALB/c mice through histopathological liver and kidney analysis and serum biochemical markers. The antibacterial efficacy of 7a (80 mg/kg/day) was assessed in a murine pneumonia model induced by ciprofloxacin-resistant S. aureus. DNA gyrase inhibition was confirmed through plasmid electrophoresis assays in E. coli DH5-α cells. Results: Compound 7a exhibited both MIC and MBC values of 0.25 μg/mL, while ciprofloxacin-resistant S. aureus strains did not exhibit a detectable MIC within the concentration range tested (up to 1024 μg/mL). In silico predictions revealed favorable ADME profiles, low toxicity, and strong interaction with DNA gyrase. In vivo, 7a showed no signs of hepatotoxicity or nephrotoxicity and effectively reduced pneumonic tissue to 1.99% in infected mice. Electrophoretic assays confirmed DNA gyrase inhibition consistent with the mechanism of fluoroquinolones. Conclusions: Compound 7a evidenced activity against ciprofloxacin-resistant S. aureus in vitro and reduced infection progression in vivo. It also displays favorable drug-like properties, low predicted toxicity, and DNA gyrase inhibition. Full article

Background/Objectives: Differentiating minimal change disease (MCD) from focal segmental glomerulosclerosis (FSGS) remains a diagnostic challenge. We hypothesised that differences in glomerular protein selectivity could translate into distinct serum protein electrophoresis (SPEP) profiles, particularly in severe nephrotic syndrome. Methods: We retrospectively analysed SPEP profiles of adults with biopsy-proven MCD (n = 27), primary FSGS (n = 27), and secondary FSGS (n = 20). Diagnoses were established according to KDIGO guidelines and the Mayo Clinic classification. A severe subgroup was defined by a relative albumin fraction <40% to evaluate patterns in marked hypoalbuminaemia. Results: Secondary FSGS demonstrated significantly higher albumin-to-globulin (A/G) ratios compared with immune-mediated podocytopathies (MCD and primary FSGS), yielding excellent discrimination (AUC > 0.98). In contrast, discriminatory performance between MCD and primary FSGS in the overall cohort was limited (AUC = 0.657). However, within the severe subgroup, the A/G ratio provided clinically meaningful separation (AUC = 0.787). An A/G ratio > 0.49 identified primary FSGS with 86.7% sensitivity and 81.2% specificity. Correlation analysis revealed a strong inverse association between albumin and α2-globulin fractions in immune-mediated podocytopathies (ρ < −0.8), whereas this relationship was attenuated in secondary FSGS (ρ = −0.57). Conclusions: The A/G ratio may represent a practical adjunctive biomarker in the evaluation of podocytopathies. Values > 1.0 strongly favour secondary FSGS, while markedly reduced ratios in severe nephrosis are characteristic of MCD. These findings suggest that differences in glomerular selectivity and the hepatic compensatory response are reflected in routine electrophoretic profiles. Full article

Collagen is a major extracellular-matrix protein widely used in regenerative medicine, yet conventional terrestrial sources raise biosafety and acceptability concerns, motivating the search for marine alternatives. This study evaluates the jellyfish Rhizostoma pulmo (R. pulmo) from the Azov Sea as a sustainable collagen source and assesses its suitability for biomedical materials. Acid-soluble collagen was extracted using 0.5 M acetic acid and purified by salt precipitation and dialysis, followed by physicochemical/structural characterization (sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE), Limulus amebocyte lysate (LAL) endotoxin testing, transmission electron microscopy (TEM), and immunofluorescence with type I collagen antibodies) and biological evaluation in vitro (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity on MRC5 fibroblasts; adhesion and proliferation assays on HeLa cells). The extracted collagen showed a high yield (~26.2%), a type I-like electrophoretic profile with α-, β-, and γ-components, fibrillar ultrastructure by TEM, and positive type I collagen immunoreactivity; endotoxin levels were low (0.461 EU/µL), and no cytotoxicity was detected under the tested conditions. Porous collagen sponges/scaffolds were fabricated by lyophilization, displaying interconnected pores with an average size of ~80 µm and pH-dependent swelling, and they supported 3D cell growth and tumor-cell dissemination in an in vitro breast carcinoma scaffold model. Overall, Azov Sea R. pulmo collagen demonstrates promising structural quality, low endotoxin burden, and cytocompatibility, supporting its potential as a marine biomaterial for sponge/scaffold-based tissue engineering and wound-related applications. Full article

Pseudomonas aeruginosa is a major causative agent of nosocomial infections worldwide. Carbapenems are the first-line agents for combating severe P. aeruginosa infections. However, the increasing prevalence of carbapenem-resistant P. aeruginosa (CRPA) has developed as a critical threat to global healthcare systems. In this study, we demonstrated that a mutation in the core nitrogen metabolism regulatory gene glnK decreases carbapenem resistance in P. aeruginosa. OprD, the major porin for carbapenem uptake, is upregulated in the glnK mutant, resulting in decreased resistance. We further found that the NtrB/NtrC two-component regulatory system is upregulated in the glnK mutant. An electrophoretic mobility shift assay (EMSA) and genetic studies revealed a direct regulatory role of NtrC on the expression of oprD. Deletion of ntrB, ntrC, or oprD in the glnK mutant restored the bacterial resistance to carbapenems. These results reveal that a GlnK-NtrB/NtrC-OprD regulatory pathway affects carbapenem resistance, shedding light on the regulatory relationship between nitrogen metabolism and carbapenem resistance in P. aeruginosa. Full article

Electrophoretic Displays (EPDs) are widely adopted in e-readers and portable devices due to their ultra-low power consumption and eye-friendly reflective characteristics. However, inherent hardware limitations, such as low resolution, slow response speed, and display degradation, frequently result in blurred strokes and degraded text readability. While traditional driving waveform optimizations can mitigate these issues, they are device-dependent and require extensive manual calibration. To address these challenges, this paper proposes an Improved Whale Optimization Algorithm-based Multi-scale Fusion Attention-enhanced SwinIR (IWOA-MFA-SwinIR) model for super-resolution and recognition of text images on EPDs. Structurally, the model incorporates a multi-scale fused attention (MFA) module that synergistically integrates channel, spatial, and gated attention mechanisms to precisely capture high-frequency text details while suppressing background noise within the SwinIR architecture. Furthermore, to enhance model robustness and eliminate manual tuning, an Improved Whale Optimization Algorithm (IWOA) is employed to adaptively optimize critical hyperparameters, including embedding dimension (d), attention head count (h), learning rate ($lr$), and dimensionality reduction coefficient (r). Experiments conducted on the TextZoom and EPD datasets demonstrate that the proposed model achieves state-of-the-art performance. In the ablation study, it attains a Peak Signal-to-Noise Ratio (PSNR) of 24.406, a Structural Similarity Index (SSIM) of 0.8837, and a Character Recognition Accuracy (CRA) of 89.81%. In the comparative evaluation, the proposed model consistently outperforms the second-best comparison model across three difficulty levels, yielding approximately a 1% improvement in PSNR, a 0.8% improvement in SSIM, and an 8% improvement in CRA. This confirms the proposed model’s superiority over mainstream comparative models in restoring text fidelity and improving recognition rates. Full article

Rosehip-based products are rich in polyphenols with recognized health benefits, making accurate characterization essential for quality control and functional evaluation. Conventional analytical approaches for polyphenol determination are often time-consuming, costly, and environmentally demanding. In this study, a sustainable analytical method based on capillary zone electrophoresis coupled with diode array detection (CE–DAD) was developed as a green and accessible screening method for polyphenol analysis in rosehip-based products. Twelve polyphenolic compounds belonging to different classes (stilbenes, flavonols, flavanols, flavanones, and flavones) were used to optimize the electrophoretic conditions, including the buffer pH, voltage, and electrolyte concentration. Herbal tea and supplement samples were analyzed before and after a simple cartridge-based clean-up step to reduce matrix interferences. The method enabled simultaneous profiling of multiple polyphenol classes in a single CE–DAD run, showing excellent linearity (R² > 0.99), run to run reproducibility (RSD 0.8–1.6%), and sensitivity (LOD 0.4–1.4 μg/mL; LOQ 0.9–4.7 μg/mL). Eight target polyphenols were identified and quantified in real samples. Polyphenol profiling was complemented by DPPH and ABTS antioxidant assays, allowing a functional interpretation of compositional data and a case-based comparison between different product formulations. Specifically, the herbal tea showed the values of a 13.8 mg Trolox/g sample (80.5% DPPH inhibition) and 15.3 mg Trolox/g sample (98.5% ABTS inhibition), whereas the food supplement presented a 7.4 mg Trolox/g sample (34.2% DPPH inhibition) and 7.4 mg Trolox/g sample (54.1% ABTS inhibition). Method sustainability and applicability were also evaluated using the Blue Applicability Grade Index (BAGI), confirming a low environmental footprint. Full article

This study investigates the development and characterization of bioactive films incorporating silver nanoparticles (AgNPs) into biocompatible polymers, namely alginate and chitosan, fabricated using two methods, spin-coating and drop-casting, and aiming to enhance their antimicrobial properties. Dynamic light scattering (DLS) and electrophoretic mobility (EM) of the film precursor solutions revealed significant changes in the nanoparticles’ size and Zeta potential (ZP), reflecting the influence of polymer coatings. Alginate contributed to high electrostatic stability due to its negative charge, while chitosan facilitated specific interactions with negatively charged surfaces. Raman spectroscopy revealed that spin-coating conditions did not successfully result in film formation, highlighting the need for further optimization. Therefore, subsequent characterization studies were conducted only for the films formed by drop-casting. Topographical and nanomechanical assessments of these drop-cast films, using atomic force microscopy (AFM) and force spectroscopy, demonstrated that AgNPs reduced adhesion and elasticity in alginate films, while increasing rigidity and adhesion in chitosan-based films. Antimicrobial tests confirmed the efficacy of AgNPs in both precursor solutions and polymer films, with chitosan-based films that retained structural integrity, which makes them suitable for prolonged applications, while alginate films displayed rapid gelation upon hydration, potentially advantageous in short-term applications. The findings underscore the potential of these biopolymer-AgNP composites in creating antimicrobial materials for food packaging, wound dressings, and other biomedical applications. However, challenges related to film deposition methods, such as spin-coating, require further optimization to improve film formation and reproducibility. Full article

Biocompatible thin films are essential for advancing biomedical devices, as they enhance integration with biological tissues, improve device longevity, and reduce complications. The rapid evolution of both medical needs and materials science has led to a diverse array of deposition techniques, each offering unique advantages and challenges for tailoring surface properties without compromising the bulk characteristics of implants and sensors. While laser-based methods—such as pulsed laser deposition (PLD) and Matrix-Assisted Pulsed Laser Evaporation (MAPLE)—are renowned for their precision, ability to preserve complex material stoichiometry, and suitability for low-temperature processing, the broader landscape includes several other important approaches. Physical Vapor Deposition (PVD) techniques, including magnetron sputtering and pulsed electron deposition, are widely used for their ability to create uniform, adherent coatings with controlled thickness and composition, making them suitable for both hard and soft biomedical substrates. Chemical Vapor Deposition (CVD) and its plasma-enhanced variant (PECVD) offer conformal coatings and excellent control over film chemistry, which is particularly valuable for functional polymer and ceramic films. Other methods, such as sol–gel processing, ion beam deposition, and electrophoretic deposition, provide additional flexibility in terms of coating composition, adhesion, and processing temperature, allowing for the fabrication of films with tailored mechanical, chemical, and biological properties. Despite these advances, the field faces ongoing challenges in optimizing film properties for specific clinical applications, ensuring reproducibility, and scaling up production for widespread use. The necessity of this review lies in its comprehensive comparison of laser-based techniques with alternative deposition methods, providing critical insights into their respective strengths, limitations, and suitability for different biomedical scenarios. By synthesizing recent developments and highlighting current gaps, this review aims to guide researchers and clinicians in selecting the most appropriate thin-film deposition strategies to meet the evolving demands of next-generation biomedical devices. Full article

This paper focuses on analyzing the corrosion mechanism of stone cutting tool surfaces. Rare earth oxide films were prepared on the tool surface using the electrophoretic deposition–sintering method, and their corrosion resistance was investigated. Microstructural and compositional analyses of the surface layer of shot-peened tools and rare earth oxide films were conducted using characterization techniques such as SEM, EBSD, and XRD. The corrosion resistance of the rare earth oxide films was evaluated via an electrochemical workstation. The results indicate that the corrosion morphology on the stone cutting tool surface is pitting corrosion, which is significantly influenced by the friction of the tool coolant. Shot-peening treatment refines the grains in the tool surface layer, promoting the growth of rare earth oxide films. The rare earth oxide film is mainly composed of cerium oxide (CeO₂), presenting a continuous and dense structure with slight peeling after sintering. The Group 3 (0.1 mol/L, 3000 V/m, 5 min) rare earth oxide film exhibits the optimal electrochemical behavior and excellent corrosion resistance, with a corrosion potential (Ecorr) of −0.49 V and a corrosion current density (icorr) of 1.445 × 10⁻⁷ A/cm². Full article

In this work, we designed non-viral gene delivery vector systems based on three poly(2-ethyl-2-oxazoline)-ran-poly[2-(3-butenyl)-2-oxazoline] copolymers functionalized by primary, secondary, and tertiary amino groups. The impact of copolymer structure and composition was sought through the examination of basic physicochemical and biological parameters. The complexation ability of copolymers with plasmid DNA was studied by ethidium bromide quenching assay. The polyplex particles size and ζ-potential were determined by dynamic and electrophoretic light scattering. The release ability of copolymers was assessed by competitive displacement of DNA using dextran sulfate. The biological performance of amino-functionalized poly(2-ethyl-2-oxazoline)-ran-poly[2-(3-butenyl)-2-oxazoline] based gene delivery systems was evaluated, and their behavior under various environmental conditions, such as pH and ionic strength, was investigated. Cytotoxicity was assessed in two human lung-derived cell lines, and the ability of the copolymers to mediate plasmid DNA delivery and expression was examined. The resulting polyplex nanoparticles exhibited the ability to release DNA molecules and sensitivity to alterations in pH and ionic strength. All systems showed high biocompatibility and were able to mediate plasmid DNA delivery, resulting in detectable EGFP expression in vitro. The vector properties were found to be driven by a multifactorial interplay among hydrophobic character, thermoresponsive behavior, polymer mobility, charge accessibility, intracellular environmental responsiveness, secondary structure effects, etc. The copolymer bearing primary amino groups displayed a distinct balance between DNA binding and release, characterized by moderate complex stability and enhanced sensitivity to environmental changes. These findings provide mechanistic insight into how amino functionality and polymer structure influence the structure–property–behavior relationships of polyoxazoline-based non-viral gene delivery systems. Full article

Amphiphilic copolymers based on polystyrene and polyglycidol combine the chemical inertness of polystyrene with the biocompatibility of polyglycidol, making them attractive materials for polymeric micelles. While comb-like architectures have been explored to control micellization behavior and biological response, a direct comparison between comb-like and coil-comb topologies in polystyrene–polyglycidol copolymers at identical polyglycidol content remains insufficiently investigated. In this work, amphiphilic comb-like and coil-comb polystyrene–polyglycidol copolymers were synthesized via copper-catalyzed azide–alkyne click chemistry by grafting a monoalkyne-terminated polyglycidol precursor onto azide-functionalized random and block styrene copolymers. The copolymers were characterized by size exclusion chromatography and nuclear magnetic resonance. Polymeric micelles were prepared by nanoprecipitation, and their self-assembly in aqueous solution was investigated by critical micelle concentration determination, dynamic and electrophoretic light scattering, and atomic force microscopy. Both copolymers formed stable aqueous dispersions and exhibited comparable critical micelle concentrations. At identical polyglycidol content, the random copolymer formed a uniform, monomodal micellar population, whereas the block-based coil-comb architecture led to bimodal size distributions, indicating the coexistence of two distinct micellar populations. The investigated systems showed low cytotoxicity and did not induce significant oxidative stress within the studied concentration range. On isolated rat brain sub-cellular fractions (synaptosomes, mitochondria and microsomes), administered alone, the comb-like and coil-comb polystyrene-polyglycidol copolymers did not reveal statistically significant neurotoxic effects. The results demonstrate that macromolecular architecture plays a key role in governing micellar organization and in vitro biological response in polystyrene–polyglycidol copolymers, highlighting their potential as architecture-controlled polymer-based nanocarriers. Full article

We present a Genetic Algorithm (GA)-based inverse design framework for creating a single-layer, fabrication-compatible dielectric nano-patterned surface that enables efficient color routing in both transmissive and reflective optical systems. Unlike traditional multilayer or absorption-based color filters, the proposed structure employs a fabrication-compatible architecture that spatially routes red, green, and blue light into designated output channels, significantly enhancing light utilization and color fidelity. The design process integrates a GA with full-wave finite-difference time-domain (FDTD) simulations to optimize the structural pillar height distribution, using a figure of merit that simultaneously maximizes optical efficiency and minimizes spectral crosstalk. For CMOS image sensor-scale designs, the nano-patterned surface achieved peak optical efficiencies of 76%, 72%, and 78% for blue, green, and red channels, respectively, with an average efficiency of 75.5%. Parametric studies further revealed the dependence of performance on pillar geometry, refractive index, and unit cell scaling, providing practical design insights for scalable fabrication using nanoimprint or grayscale lithography. Extending the approach to reflective displays, we demonstrate tunable-mirror-based architectures that emulate electrophoretic microcapsules, achieving efficient color reflection and an expanded color gamut beyond the sRGB standard. This single-layer, inverse-designed nano-patterned surface offers a high-performance and fabrication-ready solution for compact, energy-efficient imaging and display technologies. Full article

Dye-sensitized solar cells (DSSCs) are a promising alternative to traditional silicon-based technologies due to their low production costs, ease of fabrication, and wide range of applications. Among the semiconductors used in DSSCs, TiO₂ stands out for its simple, inexpensive synthesis and lower environmental impact. However, TiO₂ has limitations due to its wide bandgap and high charge-carrier recombination. In this study, the incorporation of rGO and its effect on the degree of GO reduction on Cu-doped TiO₂ particles were evaluated to enhance light interaction, improve electronic mobility, and suppress recombination. Electrophoretic deposition was employed as an alternative method to obtain Cu-doped, rGO-decorated mesoporous TiO₂ films, which were evaluated for power conversion efficiency (PCE) in DSSCs. The materials were characterized using SEM, ICP-OES, UV-Vis, XRD, BET, DLS, and TEM, while the photoanodes were analyzed using FTIR, chronoamperometry, and photovoltaic efficiency tests. The results showed clusters between 1.4 and 2.6 µm, confirming doping, a decrease in the energy gap to 2.99 eV, a stable anatase crystalline phase, and an increase in the specific surface area to 234.82 m²/g. The fabricated cells exhibited a PCE of 2.26% with a TiO₂:Cu-rGO photoanode after 20 min of GO reduction, compared to 0.96% for DSSCs with a conventional configuration. Full article

The work provides novel insight into the development of advanced antibacterial surfaces using the combination of essential oils, cinnamon oil, thyme oil, and tea tree oil, as well as their active compounds, including cinnamaldehyde, thymol, and terpinene-4-ol, embedded in the chitosan and sodium alginate matrix. All coatings obtained in a two-stage electrophoretic deposition process on stainless steel and titanium substrates were characterized by high adhesion strength. The microstructural differences between the coatings were mainly related to the size and location of the additives. Structural investigation showed the impact of individual oil components on intermolecular bonds between polysaccharide chains and the formation of molecular interactions in a specific spatial conformation. The surface of all coatings was minimally rough and had a hydrophilic character. A clear matrix-dependent trade-off between antibacterial efficacy and cytocompatibility was observed: alginate-based coatings achieved strong anti-Staphylococcus aureus activity (2.81 log CFU/mL) at the expense of increased cytotoxicity, while chitosan-based systems provided a more favorable cytocompatibility profile, maintaining cell viability above 70% for selected formulations. This work provides insight into the development of natural antibacterial surfaces by the combination of active compounds and shows the distinctions on many levels between the coatings with various polysaccharide matrices. Full article