Search

Understanding how the structure of molecules affects their permeability across cell membranes is crucial for many topics in biomedical research, including the development of drugs. In this work, we examine the transport rates of structurally similar triphenylmethane dyes, malachite green (MG) and brilliant green (BG), across the membranes of living Escherichia coli (E. coli) cells and biomimetic liposomes. Using the time-resolved second harmonic light scattering technique, we found that BG passively diffuses across the E. coli cytoplasmic membrane (CM) 3.8 times faster than MG. In addition, BG exhibits a diffusion rate 3.1 times higher than MG across the membranes of liposomes made from E. coli polar lipid extracts. Measurements on these two molecules, alongside previously studied crystal violet (CV), another triphenylmethane molecule, are compared against the set of propensity rules developed by Lipinski and co-workers for assessing the permeability of hydrophobic ion-like drug molecules through biomembranes. It indicates that BG's increased diffusion rate is due to its higher lipophilicity, with a distribution coefficient 25 times greater than MG. In contrast, CV, despite having similar lipophilicity to MG, shows negligible permeation through the E. coli CM on the observation scale, attributed to its more hydrogen bonding sites and larger polar surface area. Importantly, cell viability tests revealed that BG's antimicrobial efficacy is ∼2.4 times greater than that of MG, which aligns well with its enhanced diffusion into the E. coli cytosol. These findings offer valuable insights for drug design and development, especially for improving the permeability of poorly permeable drug molecules. [ABSTRACT FROM AUTHOR]

Due to the advancement of industrialization, water pollution has become an alarming global issue. Many organic dyes, such as crystal violet and rhodamine B, present in industrial wastewater are causing severe health problems. Both of these dyes are carcinogenic. For their degradation, ferrites are synthesized in this research. Ferrites have high absorbing potential in visible regions and fast movement of charge carrier species. Therefore, the ferrites are potentially used in photocatalysis to purify contaminated water. Graphitic carbon nitride shows enhanced separation of charges, which lowers the rate of recombination of charge carrier species. Lithium nickel ferrite, lithium nickel ferrite doped with terbium, and its composite with graphitic carbon nitride (g-C 3 N 4) are synthesized by sol-gel and ultra-sonication methods, respectively. The prepared samples are analyzed by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), Electrochemical impedance spectroscopy (EIS), and Mott-Schottky analysis. The bandgap of LiNiFe 2 O 4 and LiNiTbFe 2 O 4 was 2.35 eV, and 1.87 eV, respectively. LiNiTbFe 2 O 4 @g-C 3 N 4 degraded 86 % crystal violet and 83 % rhodamine B in 120 min. The LiNiTbFe 2 O 4 @g-C 3 N 4 composite showed the maximum degradation and can be potentially used in wastewater treatment. [ABSTRACT FROM AUTHOR]

The rampant misuse of organic dyes has exacerbated environmental pollution to an alarming degree. SrBi 4 Ti 4 O 15 , a layered perovskite semiconductor material, demonstrates considerable potential in the degradation of organic dyes, and efforts have been made to enhance its photocatalytic efficiency. In this study, La3+ doping was utilized to synthesize SrBi 4-x La x Ti 4 O 15 (x = 0, 0.10, 0.15, 0.25, 0.40) nanosheet photocatalysts, and their photocatalytic performance and underlying mechanisms were comprehensively investigated. XRD and Raman spectroscopy revealed that La3+ doping replaced Bi3+ at the A-site, resulting in a reduction of the interlayer spacing of [TiO 6 ] octahedra. Combined with DFT calculations, La3+ doping was found to widen the band gap of SrBi 4 Ti 4 O 15 and raise the Fermi level. Additionally, La3+ doping significantly increased the ratio of the Ti 3d component at the bottom of the conduction band, favoring the migration of photogenerated electrons along the [TiO 6 ] octahedra and accelerating the separation of photogenerated carriers. SEM and BET analyses revealed that La3+ doping not only increased the size of the nanosheets but also significantly enhanced their specific surface area, thereby exposing more active sites. Degradation experiments of Rhodamine B (Rh B) under UV light demonstrated that the photocatalytic efficiency of SrBi 3.75 La 0.25 Ti 4 O 15 (k = 0.0514 min-1) was 2.66 times higher than that of the original SrBi 4 Ti 4 O 15 (k = 0.0193 min-1). The theoretical degradation pathway of Rh B was elucidated using LC-MS analysis and the developmental toxicity of potential intermediates was analyzed. Moreover, the SrBi 3.75 La 0.25 Ti 4 O 15 photocatalyst also exhibited excellent degradation efficacy against Methylene Blue (MB), Crystal Violet (CV), and Methyl Orange (MO). This study provides both theoretical and experimental insights into improving the photocatalytic performance of SrBi 4 Ti 4 O 15 , thereby enhancing its potential for industrial application. [Display omitted] [ABSTRACT FROM AUTHOR]

Fabrication of a novel nanocomposite named calcium ferrite/polyaniline (CaFe2O4-PANI) was reported and its potential for adsorption of toxic cationic dye named Victoria blue (VB) was studied in this work. The CaFe2O4-PANI has showcased improved adsorptive potential for VB dye with approximately 95.35 (±1.48)% of removal efficiency at solution pH 8.0, CaFe2O4-PANI dose of 0.5 g/L, contact time of 20 min and initial VB dye concentration of 50 mg/L. The adsorption process follows pseudo-second-order kinetic model and Freundlich isotherm model with a maximum uptake capacity of 266.67 mg/g. The adsorbent was also tested against surface and ground water sample loaded with VB dye and in presence of several ions. It was found that surface water has caused less interference (∼2 (±0.85)% reduction in VB dye removal efficiency) followed by ground water (∼4 (±0.91)% reduction) and wastewater (∼8 (±1.24)% reduction) and also the removal efficiencies are affected the most by bicarbonate ions (∼12 (±1.39)%–14 (±1.62)% reduction in VB dye removal efficiency). The experimental process was optimized utilizing a five level, three factor based response surface methodology (RSM) approach and the experimental parameters were optimized to CaFe2O4-PANI dosage = 0.5 g/L, contact time = 65 min and initial VB dye conc. = 60 mg/L, using the developed quadratic model to achieve a maximum VB removal efficiency of 98.63 (±2.13)%. Regeneration study suggests that the fabricated adsorbent can be reused up to five cycles with ∼10 (±1.13)% decrease in the VB dye removal efficiency. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusion Routine prescription of antibiotics to treat chronic rhinosinusitis (CRS) exacerbations may contribute to the propagation of antibiotic resistance. Hops bitter β‐acids lupulone and colupulone possess potent antibacterial activities and, as T2R1, T2R14, and/or T2R40 agonists, may improve the impaired mucociliary clearance described in CRS patients. We investigated these molecules as alternative treatments to antibiotics in CRS management based on their antibacterial and T2Rs agonists properties.Human nasal primary cells (HNECs) and RPMI2650 cells cultures were used as study models. T2Rs expression in cell culture models and human nasal tissue was assessed using immunofluorescence, quantitative PCR, and Western blot. We performed calcium imaging and cilia beat frequency experiments to investigate T2Rs activation in study models in response to lupulone and colupulone stimulations. Finally, we studied hops β‐acids cytotoxicity on cells using CellEvent, crystal violet, lactate dehydrogenase assays, immunofluorescence, and transepithelial electrical resistance assays.We confirmed lupulone and colupulone potent antibacterial effect on CRS‐relevant methicillin‐resistant Staphylococcus aureus but found minimal impact on P. aeruginosa. We also report T2R1, T2R14 and T2R40 expression in HNECs and RPMI2650 cell cultures. Lupulone and colupulone induced an increase in cytosolic calcium that appeared dependent on T2Rs signaling. This response was accompanied by mitochondrial membrane depolarization, cellular energy stress, decreased cell proliferation, ciliostasis, and HNECs remodeling after a single exposure to lupulone at micromolar concentrations.Our data suggest that hops β‐acids may not be beneficial as treatments in CRS patients and instead contribute to the disease by impairing cell health and further deteriorating the MCC. [ABSTRACT FROM AUTHOR]

Nitrocellulose (NC) finds widespread use in propellants and launchers. Nanoscale modification can effectively enhance its combustion performance by shortening the mass and heat transfer distance. However, it also presents greater safety challenges for storage and application. To further investigate the thermal safety characteristics of nanoscale NC, this study explores the impact of additives on nanoscale NC. Nanoscale NC was prepared via electrospinning, and the samples were characterized using focused ion beam scanning electron microscopy to examine the influence of precursor concentration and stabilizer on sample morphology, leading to the formulation determination. Samples incorporating triphenylamine and lithium carbonate (Li2CO3) were fabricated using both electrospinning and traditional mechanical mixing techniques. Following preparation, fourier transform infrared spectroscopy, the methyl violet test, and thermogravimetry–differential scanning calorimetry were performed on six samples, each prepared using different methods and additives. These analyses aimed to investigate the thermal decomposition characteristics of the samples under varying heating rates. The study also compared the impact of nanoscale modification on the thermal performance of composite nitrocellulose. Various model-free methods were employed to calculate the relationship between activation energy and conversion rate and to analyze alterations in activation energy. Considering the thermal decomposition characteristic parameters, the study delved into the stabilizing effect of typical stabilizers in nanocomposite fibers. This research is instrumental in guiding preparation process optimization, promoting the application of NC-stabilizer mixtures, and providing valuable references for the preparation and thermal stability investigations of similar nanomaterials. [ABSTRACT FROM AUTHOR]

Background: Conventional antibacterial compounds can inhibit the growth of microorganisms, but their adverse effects and the development of drug limit their widespread use. The current study aimed to synthesize PEG-coated UIO-66-NH2 nanoparticles loaded with vancomycin and amikacin (VAN/AMK-UIO-66-NH2@PEG) and evaluate their antibacterial and anti-biofilm activities against vancomycin-resistant Staphylococcus aureus (VRSA) clinical isolates. Methods: The VAN/AMK-UIO-66-NH2@PEG were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS) to determine their size, polydispersity index (PDI), encapsulation efficiency (EE%), zeta-potential, drug release profile, and physical stability. Antibacterial activity was evaluated using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill assays. Biofilm formation by VRSA was assessed using the crystal violet (CV) and minimum biofilm eradication concentration (MBEC) assays. The effect of sub-MIC concentrations of the formulations on the expression of biofilm-related genes (icaA, icaD) and resistance-related genes (mecA, vanA) was investigated using quantitative real-time polymerase chain reaction (RT-qPCR). Results: As demonstrated by MIC, MBC and time-kill assay, the VAN/AMK-UIO-66-NH2@PEG nanoparticles exhibited enhanced antibacterial activity against VRSA isolates compared to free drugs and prepared formulations. Furthermore, CV and MBEC tests indicated that the VAN/AMK-UIO-66@NH2/PEG can reduce biofilm formation dramatically compared to VAN/AMK and VAN/AMK-UIO-66@NH2, due to its great drug release properties. This study also found that the expression level of the mecA, vanA, icaA, and icaD genes in VAN/AMK-UIO-66@NH2/PEG treated VRSA isolates was substantially decreased compared to other groups. Conclusions: These findings highlighted the efficiency of VAN/AMK-UIO-66@NH2/PEG in combating antimicrobial resistance and biofilm formation in VRSA isolates. Future studies, particularly in vivo models, are necessary to evaluate the safety, efficacy, and clinical applicability of these nanoparticles for the treatment of bacterial infections. [ABSTRACT FROM AUTHOR]

Background : Acinetobacter baumannii (AB) is a notable cause of hospital-acquired infections, with carbapenem-resistant Acinetobacter baumannii (CRAB) classified as a high-priority critical pathogen. Bacteriophage therapy is emerging as a promising alternative to combat drug-resistant bacterial infections. In this study, a lytic phage, HZY2308, was isolated from hospital sewage, and the biological properties, biosafety and anti-biofilm properties of phage HZY2308 were characterized and identified. Moreover, the antibacterial effect of phage HZY2308 in combination with antibiotics was investigated, and the apparent characteristics of phage-resistant strain AB48-R were demonstrated, which provided data support for further studies to elucidate the mechanism of generating phage resistance. Methods: Phage HZY2308 was isolated by double agar plate method using clinical strain AB48 as the host bacterium. The morphology of phage HZY2308 was identified by transmission electron microscopy (TEM), and biological characteristics of phage HZY2308 were identified by host range, the efficiency of plating (EOP), sensitivity to temperature, pH, and chloroform, one-step growth curve, the optimal multiplicity of infection (MOI), and detection of endotoxin and cytotoxicity. Besides, the complete genome map of HZY2308 was constructed using CGview, and the phylogenetic tree of HZY2308 was constructed with MEGA. Additionally, the full genomic sequence of phage HZY2308 and the selected phage were compared using Easyfig. Checkerboard test of phage HZY2308 in combination with tigecycline (TGC) was performed to investigate their synergistic effect and bactericidal kinetics. The effect of HZY2308 on biofilm was investigated by semi-quantitative staining of biofilm with crystal violet, determination of bacterial activity in biofilm by 2,3-Bis (2-methoxy-4-nitro-5-sulfophenyl) -2 H-tetrazolium-5-carboxanilide (XTT) assay and observation of biofilm structure by fluorescence microscopy. Finally, Phage-resistant bacteria AB48-R were characterized by colony-forming capacity, morphology, growth curves, adsorption efficiency, and antibiotic susceptibility assays. Results: A lytic phage, HZY2308, was isolated from hospital sewage, which exhibited advantageous traits such as a brief incubation period, large burst size, and robust stability. Safety assessments conducted at both genetic and cellular levels also have yielded positive outcomes. Besides, phage HZY2308 effectively inhibited AB biofilm formation and disrupted established biofilm structures. Furthermore, a synergistic antibacterial effect was noted when phage HZY2308 was combined with tigecycline. Interestingly, the phage-resistant strain, AB48-R was screened through natural selection. Compared to the wild strain AB48, the adsorption efficiency of the phage to AB48-R diminished. However, AB48-R's sensitivity to antibiotics such as cefepime, gentamicin, amikacin, and tobramycin increased, indicating an evolutionary trade-off. Conclusions: Phage HZY2308 shows strong antimicrobial potential, especially in combination with tigecycline, and the phage-resistant strain exhibits increased antibiotic sensitivity. [ABSTRACT FROM AUTHOR]

The search for materials to treat wastewater is especially crucial. Herein, we have prepared 1D molybdenum oxide (MoO 3) nanobelts through a hydrothermal approach. The binary (MoO 3 /SiO 2) and ternary composites of MoO 3 /SiO 2 /MXene were synthesized via ultrasonication route. The as-prepared MoO 3 , MoO 3 /SiO 2, and MoO 3 /SiO 2 /MXene composites were employed to investigate the photocatalytic behavior of two organic dyes, methyl orange (MO) and crystal violet (CV). The % degradation of MO in the presence of MoO 3 nanobelts and MoO 3 /SiO 2 was calculated to be 48.9 % and 74.4 %, respectively. In the case of CV dye, the degradation (%) was observed at 53.7 % and 75.9 %. The MoO 3 /SiO 2 /MXene composite revealed the best photocatalytic behavior against both MO and CV dyes by removing 94.7 % and 97.7 % under visible light irradiation. The rate constant values of MoO 3 nanobelts, MoO 3 /SiO 2 and MoO 3 /SiO 2 /MXene composite for MO dye were calculated to be 0.00568 min−1, 0.01156 min−1, and 0.02399 min−1 and for CV dye 0.00679 min−1, 0.01208 min−1, and 0.02798 min−1 respectively. A scavenging test was carried out to monitor the main photo-active species that take part during the photocatalysis and hydroxyl radicals were found to be the highly active species during whole photodegradation progression. The SiO 2 particles function as a good adsorbent medium and transfer the adsorbed organics toward more active sites to advance the reaction. 2D MXene nanosheets, as good conductors, reduce the recombination rate of charges, offer large surface area, and facilitate fast transfer of charges. The results suggest that MoO 3 /SiO 2 /MXene composite is a potential contender for wastewater remediation applications. [Display omitted] • Ternary composite (MoO 3 /SiO 2 /MXene) was synthesized using an ultrasonication approach, with a crystallite size of 19.48 nm. • SEM analysis confirmed the successful synthesis of MoO 3 nanobelts and their ternary composite with SiO 2 and MXene sheets. • The synthesized samples were utilized for the photodegradation of two organic dyes, Crystal Violet and Methyl Orange. • The MoO 3 /SiO 2 /MXene nanocomposite demonstrated the highest photocatalytic activity against both dyes. [ABSTRACT FROM AUTHOR]

Background/Objectives: To assess the cytocompatibility, antibacterial and anti-biofilm efficacy of grape seed extract (GSE) and quercetin hydrogels versus calcium hydroxide (CH) as intracanal medications (ICMs) against an endodontic ex vivo biofilm model. Methods: Single-rooted teeth (n = 50) were prepared and sterilized before being infected with E. faecalis to develop a mature biofilm. They were divided into five equal groups according to the ICM used: G1: medicated with CH paste, G2: medicated with GSE hydrogel, G3: medicated with quercetin hydrogel, G4: positive control group that was infected and not medicated, and G5: negative control group that was neither infected nor medicated. After 1 week, the ICM was removed, and the root canals were cultured to assess the antibacterial efficacy by counting the colony-forming units and the anti-biofilm efficacy by the crystal violet assay. Dead/live bacterial viability was assessed by CFLSM examination, while the cytocompatibility was assessed using the MTT assay. Results: CH had the best antibacterial efficacy, followed by GSE and quercetin hydrogels (p < 0.001). Regarding the anti-biofilm efficacy, GSE was superior, followed by quercetin and CH (p < 0.001). CFLSM examination showed CH and GSE hydrogel to be highly effective in comparison to the positive control (p < 0.0001), with no statistical difference between them (p > 0.05). CH showed significantly higher cell viability percentages using a 500 μg/mL, while quercetin and GSE started to show cell viability > 70% at concentrations of 125 μg/mL and 62.5 μg/mL. Conclusions: CH fulfilled the ideal requirements of ICM as being both antibacterial and non-cytotoxic compared to the other materials tested. [ABSTRACT FROM AUTHOR]

Monomers: gentian violet (GV), brilliant green (BG), aniline, and methyl violet (MV), as well as their copolymers, were electropolymerized and used to modify glassy carbon electrode (GCE) by enhancing the sensitivity of the electrode. This is due to their special characteristics of sensing ability of the electropolymerized polymers. The electropolymerization and characterization of these monomers and their copolymers were done using cyclic voltammetry (CV) on GCE as a working electrode against Ag/AgCl reference electrode and platinum wire as the counter electrode. The copolymers showed higher current peaks than their corresponding homopolymers. The electrochemical characterization of these polymers and copolymers was studied by scan rate effect each between 10 and 300 mV/s and pH effect between 1.56 and 5.30. After being modified by the copolymers: poly(BG-GV) and poly(BG-MV), the modified GCE showed good results in resolving the peaks of ascorbic acid and uric acid which otherwise showed an overlapped broad peak on bare GCE. The CV in bare GCE was scanned at different scan rates of 4 mM K3[Fe(CN)6] in 1 M KNO3 solution. The square root of scan rate dependence of peak current was plotted and the Randles–Sevcik equation was applied to determine the diffusion coefficient of Fe(CN)63− ion and which was 1.13 × 10–14 cm2/s. This was used to determine the area of the modified electrode after running the CV of 4 mM K3[Fe(CN)6] in 1 M KNO3 at different scan rates. Therefore, the electrochemical polymerization of organic dye polymers was able to increase the sensitivity of the electrode by increasing its area. [ABSTRACT FROM AUTHOR]

As a noninvasive and label-free optical technique, Raman spectroscopy offers significant advantages in studying the structure and properties of biomacromolecules, as well as real-time changes in cellular molecular structure. However, its practical applications are hindered by weak scattering responses, low signal intensity, and poor spectral uniformity, which affect the subsequent accuracy of spectral analysis. To address these issues, we report a novel surface-enhanced Raman scattering (SERS) substrate based on a pyramidal pitted silicon (PPSi) array structure adhered with Au-shell Ag-core nanospheres (Au@Ag NSs). By preparing a highly uniform PPSi array substrate with controllable size and arrangement, and constructing SERS-active Au@Ag NSs on this substrate, a three-dimensional (3D) composite SERS substrate is realized. The enhancement performance and spectral uniformity of 3D composite SERS substrate were examined using crystal violet (CV) and Rhodamine 6G (R6G) molecules, achieving a minimum detectable concentration of R6G at 10−9 M and the analytical enhancement factor (AEF) of 4.2 × 108. Moreover, SERS detection of biological samples with varying concentrations of Staphylococcus aureus demonstrated excellent biocompatibility of the SERS substrate and enabled quantitative analysis of bacterial concentration (R2 = 99.7 %). Theoretical simulations using finite-difference time-domain (FDTD) analysis were conducted to examine the electromagnetic field distribution of the three-dimensional SERS composite substrate, confirming its local electric field enhancement effect. These experimental and theoretical results indicate that the Au@Ag NSs/PPSi substrate with a regulable pyramidal pitted array is a promising candidate for sensitive, label-free SERS detection in medical and biotechnological applications. [ABSTRACT FROM AUTHOR]

In this study, chromium‐based metal–organic framework (MIL‐101(Cr)) was incorporated into polyvinyl alcohol nanofibers (PVA NFs) via green electrospinning followed by heat treatment to fabricate MIL‐101(Cr)@PVA NFs composite without the need for any organic solvent or other dispersants. The fabricated MIL‐101(Cr)@PVA NFs were comprehensively characterized using a suite of common techniques. Morphological characteristics of MIL‐101(Cr)@PVA NFs showed a fibrous structure with an average diameter of 228 ± 37 nm and decorated with MIL‐101(Cr) particles arranged in a nanoneedle‐like pattern. Subsequently, its adsorption efficiency towards the cationic crystal violet dye (CV) was evaluated through batch adsorption experiments. The influence of various experimental parameters on CV removal efficiency was systematically optimized using a factorial design approach. The Langmuir isotherm and kinetic pseudo‐second‐order (PSO) model provided an excellent fit to the adsorption equilibrium data, indicating a maximum adsorption capacity (qmax) of 344.18 mg/g for MIL‐101(Cr)@PVA NFs compared with 83.94 mg/g for pristine PVA NFs. Furthermore, the MIL‐101(Cr)@PVA NFs composite demonstrated excellent reusability and stability, maintaining a significant portion of its removal capacity even after six adsorption–desorption cycles. These findings highlight the potential of the fabricated composite as a highly efficient and reusable adsorbent for CV removal from wastewater treatment applications. Highlights: The MIL‐101(Cr)@PVA NFs nanocomposite fabricated by electrospinning technique.The MIL‐101(Cr) particle arranged in a nanoneedle‐like pattern in the PVA NFs.Incorporation of MIL‐101(Cr) improved qmax of PVA by 391.5%.The MIL‐101(Cr)@PVA NFs membrane has excellent stability and reusability. [ABSTRACT FROM AUTHOR]

Biofilms are a severe problem for public health because of the contributing recurrence of infections. Therefore, combating biofilms is a critical issue. In our study, we loaded zinc oxide (ZnO), zinc oxide borax (ZnOBorax), zinc copper oxide (ZnCuO2) nanoparticles and borax into bacterial cellulose (BC) to impart anti-biofilm and wound healing activity. The prepared BC loaded with nanoparticles (BC–NPs) was analysed via scanning electron microscopy. The nanoparticles' geometric structure and placement in BC fibres were observed. We evaluated the biofilm inhibition and biofilm degradation activities of the BC–NPs against some pathogens via a crystal violet (CV) assay and XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2 H-tetrazolium-5-carboxanilide) reduction assay. The effects of BC–NPs on cell proliferation and wound-healing ability were analysed in L929 cell line. BC–NPs exhibited better biofilm degradation activity than biofilm inhibition activity. According to the results of the CV assay, BC–ZnONPs, BC–Borax and BC–ZnOBoraxNPs inhibited 65.53%, 71.74% and 66.60% of biofilm formation of Staphylococcus aureus, respectively. BC–ZnCuO2NPs showed the most degradation activity on Pseudomonas aeruginosa and Listeria innocua biofilms. The XTT reduction assay results indicated a considerable reduction in the metabolic activity of the biofilms. Moreover, compared to the control group, BC loaded with borax and ZnO nanoparticle promoted cell migration without cytotoxicity. [ABSTRACT FROM AUTHOR]

Biofilms reduce antibiotic efficacy and lead to complications and mortality in human and equine patients with orthopedic infections. Equine bone marrow-derived mesenchymal stromal cells (MSC) kill planktonic bacteria and prevent biofilm formation, but their ability to disrupt established orthopedic biofilms is unknown. Our objective was to evaluate the ability of MSC to reduce established S. aureus or E. coli biofilms in vitro. We hypothesized that MSC would reduce biofilm matrix and colony-forming units (CFU) compared to no treatment and that MSC combined with the antibiotic, amikacin sulfate, would reduce these components more than MSC or amikacin alone. MSC were isolated from 5 adult Thoroughbred horses in antibiotic-free medium. 24-hour S. aureus or E. coli biofilms were co-cultured in triplicate for 24 or 48 hours in a transwell plate system: untreated (negative) control, 30 μg/mL amikacin, 1 x 106 passage 3 MSC, and MSC with 30 μg/mL amikacin. Treated biofilms were photographed and biofilm area quantified digitally. Biomass was quantified via crystal violet staining, and CFU quantified following enzymatic digestion. Data were analyzed using mixed model ANOVA with Tukey post-hoc comparisons (p < 0.05). MSC significantly reduced S. aureus biofilms at both timepoints and E. coli biofilm area at 48 hours compared to untreated controls. MSC with amikacin significantly reduced S. aureus biofilms versus amikacin and E. coli biofilms versus MSC at 48 hours. MSC significantly reduced S. aureus biomass at both timepoints and reduced S. aureus CFU at 48 hours versus untreated controls. MSC with amikacin significantly reduced S. aureus biomass versus amikacin at 24 hours and S. aureus and E. coli CFU versus MSC at both timepoints. MSC primarily disrupted the biofilm matrix but performed differently on S. aureus versus E. coli. Evaluation of biofilm-MSC interactions, MSC dose, and treatment time are warranted prior to testing in vivo. [ABSTRACT FROM AUTHOR]

AbstractThe purpose of this work was to characterize and identify the bacteria isolated from highly polluted locations that could potentially be able to withstand extremely toxic heavy metals. The study area selected for bacterial isolation from sediment samples was Kuzhikandam Creek, a tributary of the Periyar River and one of the world’s most hazardous hotspots, located in Kochi’s Eloor industrial region. Heavy metal analysis of chromium, copper, and lead in sediment samples was performed, and the results showed that the concentrations were greater than permissible limits. Several metal-resistant bacteria were isolated from sediments, which, upon further screening in solid media at different concentrations of chromium, copper, and lead, found three highly resistant species (S1B1, S2B2, and S3B3), one from each site. The phenotypic and biochemical characterization of these bacteria was examined using standard procedures. The ability of these species to generate biofilm was examined using methods like the crystal violet assay (qualitative assessment) and also using the scanning electron microscope. The antibiotic susceptibility of these species was tested with six different antibiotics, which are used in various disease treatments. These isolates, sequenced using the 16S rRNA Sanger dideoxy method, have been identified as Staphylococcus arlettae, Bacillus paramycoides, and Cellulosimicrobium funkei. [ABSTRACT FROM AUTHOR]

ABSTRACT Three novel complexes of copper(II), ruthenium(III), and thorium(IV) ions with quinaldine azo dye ligand HL were synthesized in nanoscale. Applying mass spectroscopy, electronic, infrared, 1H NMR, elemental, and thermal investigations, their structures were examined. By using azo nitrogen and hydroxyl oxygen atoms to coordinate as a monobasic bidentate, it was found that the ligand displayed bicapped square antiprism geometry with thorium(IV) metal ion, square pyramidal arrangement in copper(II) complex and octahedral configuration in ruthenium(III) complex. In order to confirm the complexes' geometrical arrangement, theoretical investigations were carried out using DFT/B3LYP/6–311 + G(d,p)/LANLDZ. The dipole moment, geometrical configuration, energetic parameters, and HOMO–LUMO gap of energy have been calculated. The compounds were formed in nanometric forms, as indicated by the mean particle sizes obtained by applying TEM. Based on TEM images for the complexes of copper(II), ruthenium(III), and thorium(IV), their average particle sizes were 11.04, 3.89, and 1.52 nm, respectively. PANC‐1 and A‐549 cells were used in the tests to evaluate the compounds' anticancer activity against the vinblastine reference. The findings confirm the great cytotoxicity effect of the free ligand and its complexes against the investigated cell lines using different doses of the examined compounds. Ru(III) and Cu(II) complexes exhibited cytotoxic effectiveness greater than that of vinblastine. The azo ligand, HL, exhibited the strongest antibacterial activity that is superior to that of the conventional medicines themselves and greater than that of its metal complexes. The most physiologically active compound's ideal conformation was found using molecular docking research, and the manner in which the Ru(III) complex and the enzyme of Panc‐1 link together was determined. It interacts in three different modes with the target receptor (PANC‐1): hydrophobic force, electrostatic force, and H‐bond. In addition to increasing the candidate activity, these interactions can be used to design and predict new, effective compounds. The capacity of the ligand and its complexes to act as heterogeneous catalysts for the oxidation of methyl violet 2B was examined. The ruthenium(III) and thorium(IV) complexes generated the greatest catalytic efficiencies. [ABSTRACT FROM AUTHOR]

This paper presents the preparation of Al‐doped mixed transition metal ferrite (AlxCo0.7Mn0.3Fe2−xO4 where x=0.1, 0.3, 0.5, 0.7 and 0.9) via a solution combustion method, followed by an application for the removal of dyes from aqueous solution. Various physicochemical techniques were employed to determine the morphological, structural, magnetic behaviour and adsorption characteristics of the synthesized ferrites by through Scanning Electron Microscope (SEM), X‐ray powder Diffraction (XRD), Fourier Transform Infra‐Red spectroscopy (FT‐IR), Vibrating Sample Magnetometer (VSM), and Brunauer‐Emmett‐Teller (BET) analysis. Furthermore, the as‐synthesized ferrite materials were utilized for adsorbing dyes (Methylene blue (MB), Crystal violet (CV), Methyl orange (MO), and Congo red (CR)) from aqueous solutions, with the results reported using UV‐visible spectroscopy. The findings indicate that Al‐doped mixed transition metal ferrites serve as potential adsorbents for dye removal. [ABSTRACT FROM AUTHOR]

Energy and water are essential resources currently facing high demand due to the depletion of fossil fuels and increasing water pollution. Conducting polymers like polyaniline (PANI) have gained attention for addressing these challenges. In this study, polyaniline/pullulan composites (PANI/Pul Cps) are synthesized via oxidative polymerization. The influence of the aniline‐to‐pullulan mass ratio on the composite properties is evaluated using various techniques. XRD analysis showed enhanced crystallinity with the addition of pullulan, while TEM results revealed that the composites exhibited a rod‐like shape, with dimensions of 51–55 nm in width and 131–152 nm in length. The photocatalytic potential of the composites is assessed by testing their ability to degrade Crystal Violet dye, with the highest degradation rate observed at 0.0086 min⁻¹. The electrochemical performance of the PANI/Pul Cps is also evaluated, with specific capacitance values ranging from 92 to 123 F/g. These results suggest that PANI/Pul Cps have potential for both wastewater treatment and energy storage applications. [ABSTRACT FROM AUTHOR]

Background: Biofilm formation is an essential virulence factor that creates a highly protected growth mode for Staphylococcus aureus (S. aureus) to survive in any hostile environment. Antibiotic sub-minimal inhibitory concentration (sub-MIC) may modulate the biofilm formation ability of bacterial pathogens, thereby affecting bacterial pathogenesis and infection outcomes. Intense antimicrobial therapy to treat biofilm-associated infections can control the pathogenic infection aggravation but cannot guarantee its complete eradication. Objective: This study aimed to assess the sub-MICs effect of 5 different antimicrobial classes on biofilm-forming capacity among Staphylococcus aureus clinical isolates using three different biofilm quantitation techniques. Methods: In this study, the effects of 5 different antimicrobial agents, namely, azithromycin, gentamicin, ciprofloxacin, doxycycline, and imipenem, at sub-MICs of 12.5%, 25%, and 50% were tested on 5 different clinical isolates of S. aureus. The biofilms formed in the absence and presence of different antimicrobial sub-MICs were then assessed using the following three different techniques: the crystal violet (CV) staining method, the quantitative PCR (qPCR) method, and the spread plate method (SPM). Results: Biofilm formation was significantly induced in 64% of the tested conditions using the CV technique. On the other hand, the qPCR quantifying the total bacterial count and the SPM quantifying the viable bacterial count showed significant induction only in 24% and 17.3%, respectively (Fig. 1). The difference between CV and the other techniques indicates an increase in biofilm biomass without an increase in bacterial growth. As expected, sub-MICs did not reduce the viable cell count, as shown by the SPM. The CV staining method revealed that sub-MICs of imipenem and ciprofloxacin had the highest significance rate (80%) showing an inductive effect on the biofilm development. On the other hand, doxycycline, azithromycin, and gentamicin displayed lower significance rates of 73%, 53%, and 47%, respectively. Conclusion: Exposure to sub-MIC doses of antimicrobial agents induces the biofilm-forming capacity of S. aureus via increasing the total biomass without significantly affecting the bacterial growth of viable count. [ABSTRACT FROM AUTHOR]

ABSTRACT The rapid increase of water pollution globally is a vital environmental concern that requires the immediate attention of researchers to find new innovative ways to remove unwanted environmental pollutants from our water sources. With the advances in the field of sustainable engineering, there is a high demand for the effective utilization of biomass resources for the removal of aqueous environmental contaminants. Biochar is carbon carbon‐enriched substance obtained by biomass pyrolysis; it is inexpensive and has received wide attention in the field of wastewater treatment. Herein, we describe the synthesis of pea pod (PO) biochar‐reinforced zeolitic imidazolate framework (ZIF‐8) nanocomposite (PO@ZIF‐8) through the in situ precipitation of ZIF‐8 onto the biochar surface. The crystal growth, morphology, chemical composition, and optical characteristics of fabricated PO@ZIF‐8 nanocomposite were scrutinized through PXRD, SEM, TEM, UV‐DRS, PL, and XPS analysis. The dodecahedral‐shaped PO@ZIF‐8 particles have an average size between 140 and 160 nm. The biochar‐reinforced ZIF‐8 nanocomposite showed significantly higher photocatalytic activity than the pure ZIF‐8 for the degradation of two commonly found organic dyes crystal violet (CV) and Victoria Blue (VB) in the presence of direct sunlight irradiation. The PO@ZIF‐8 nanocomposite showed the highest degradation efficiency of ~87% and ~80% within 50 min of irradiation time at a catalyst dosage of 20 mg for 30 ppm CV and VB dye solutions at pH 8. First‐order kinetics were obeyed during the photodegradation with 0.041 and 0.030 min−1 as the constant of degradation for the removal of CV and VB. The radical scavenger experiment and the photoluminescence analysis confirm the active participation of ·OH radical in the degradation of both dyes. LC–MS and TOC analysis was also performed to determine the degradation products and for evaluation of the degradation progress. Moreover, the synthesized PO@ZIF‐8 composite also exhibit good stability till the fourth cycle with high degradation efficiency thus making it a good choice of catalyst in the field of environmental decontamination. [ABSTRACT FROM AUTHOR]

Introduction: Food spoilage and pathogenic bacteria on food-contact surfaces, especially biofilm-forming strains, can transfer to meats during processing. The objectives of this study were to survey the bacterial communities of beef cuts that transfer onto two commonly used food-contact surfaces, stainless steel (SS) and high-density polyethylene (HDPE) and identify potentially biofilm-forming strains. Methods: Top round, flank, chuck, and ground beef were purchased from 3 retail stores. SS and HDPE coupons (approximately 2cm × 5cm) were placed on beef portions (3h, 10°C), after which, the coupons were submerged halfway in PBS (24h, 10°C). Bacteria from the beef cuts and coupon surfaces (n = 3) were collected, plated on tryptic soy agar plates and incubated (5 days, 25°C). Bacterial isolates were identified by 16S rRNA gene amplicon sequencing and assayed for biofilm formation using a crystal violet binding (CV) assay (72h, 10°C). Additionally, beef and coupon samples were collected for bacterial community analysis by 16S rRNA gene amplicon sequencing. Results and discussion: Sixty-one of 972 beef isolates, 29 of 204 HDPE isolates, and 30 of 211 SS isolates were strong biofilm-formers (Absorbance>1.000 at 590 nm in the CV assay). Strong-binding isolates identified were of the genera Pseudomonas, Acinetobacter, Psychrobacter, Carnobacterium, and Brochothrix. Coupon bacterial communities among stores and cuts were distinct (p < 0.001, PERMANOVA), but there was no distinction between the communities found on HDPE or SS coupons (p > 0.050, PERMANOVA). The bacterial communities identified on the coupons may help determine the communities capable of transferring and colonizing onto surfaces, which can subsequently cross-contaminate foods. [ABSTRACT FROM AUTHOR]

Sodium alginate beads were explored as an adsorbent for exclusion of CV dye in batch mode by optimizing various parameters such as solution pH, effect of dye concentration, adsorbent's dose, contact time, and temperature. Experimental results revealed that maximum sorption, i.e., 97% was obtained at pH 12 in 20 minutes of contact time, 0.4 g of beads for 10 mL of dye solution at 30 °C. Characterization of sodium alginate beads confirmed that hydroxyl, carboxyl, amine, and sulfate functional groups are involved in dye adsorption on heterogeneous and porous surface of adsorbent. Isotherm study shows that Freundlich model fits best to experimental data having highest possible adsorption capacity of 4.797 mg g − 1 . Further, kinetic study revealed that pseudo-second order model plays a significant role in adsorption mechanism with R 2 = 0.9996. Suitability of each model is also checked by five error analysis models namely Hybrid, MPSD, EABS, ERRSQ, and ARE. Thermodynamic studies implied that CV dye adsorption on sodium alginate beads was spontaneous and endothermic in nature as confirmed from Δ G = −7.8 to −5.8 kJ mol−1 and Δ H = 10.201 kJ mol−1, respectively. Results also show that 92% of dye adsorption take place with tap water. Based on experimental outcomes, it has been concluded that sodium alginate beads are an excellent adsorbent to remove the CV dye from the solution. [ABSTRACT FROM AUTHOR]

Drinking water distribution systems (DWDSs) may be contaminated to various degrees when different microorganisms attach to the pipe walls. Understanding the characteristics of biofilms on pipe walls can help prevent and control microbial contamination in DWDSs. The biofilm formation, interspecific interactions, and chlorine resistance of 10 dual-species biofilms in polyethylene (PE) and cast iron (CI) pipes were investigated in this paper. The biofilm biomass (heterotrophic bacterial plate count and crystal violet) of dual species in CI pipes is significantly higher than that in PE pipes, but the biofilm activity in CI pipes is significantly lower than that in PE pipes. The interspecific interaction of Sphingomonas-containing group presented synergistic or neutral relationship in PE pipes, whereas the interspecific interaction of the Acidovorax-containing group showed a competitive relationship in CI pipes. Although interspecific relationships may help bacteria resist chlorine, the chlorine resistance was more reliant on dual-species groups and pipe materials. In CI pipes, the Microbacterium containing biofilm groups showed better chlorine resistance, whereas in PE pipes, most biofilm groups with Bacillus exhibited better chlorine resistance. The biofilm groups with more extracellular polymeric substance (EPS) secretion showed stronger chlorine resistance. The biofilm in the PE pipe is mainly protected by EPS, while both EPS and corrosion products shield the biofilms within CI pipe. These results supported that dual-species biofilms are affected by pipe materials and interspecific interactions and provided some ideas for microbial control in two typical pipe materials. [ABSTRACT FROM AUTHOR]

Featured Application: Although this is a fundamental microbiological study, its results indicate the necessity of changing the approach to fish ponds maintenance and focusing all hygiene measures on the eradication of biofilms and not on a simple disinfection. Also, the practical laboratory approach to testing biofilms of A. salmonicida subspecies salmonicida should be changed. Biofilm formation of clinical isolates of Aeromonas salmonicida subspecies salmonicida was compared using scarce (minimal M9 and ABTG w/o amino acids) and enriched nutrient media (Tryptone Soya broth) at 8 °C, 16 °C, and 25 °C using direct enumeration of viable cells in biofilm (log CFU), crystal violet staining (ODc) of the formed biofilm biomass, and liquid–air border biofilm formation (pellicle test). Whole-genome sequencing (WGS) was performed with the usage of an Oxford nanopore system by Genomics and Transcriptomics Labor Düsseldorf (Heinrich-Heine-Universität Düsseldorf, Germany). A bioinformatic analysis was performed with the usage of Geneious Prime® 2023.0.4 (Biomatters, Inc., Boston, MA, USA). All data were analyzed using Statistica software version 13.0, and changes in biofilm production in correlation to changes in the type of nutritional medium and temperature were compared between groups using a one-way ANOVA analysis and Tukey's test. All isolates formed biofilms in minimal M9 at 8 °C and 16 °C, and nine isolates failed to form biofilms in minimal M9 at 25 °C. In an ABTG medium, all isolates produced biofilms at 8 °C; however, three isolates at 16 °C and seven isolates at 25 °C failed to form any biofilms. Significant biofilm formation was observed in TSB at all temperatures. Some strains that formed a good biofilm in solid–liquid interface did not have the ability to form a pellicle (liquid–air border biofilm), and vice versa. In all cases of nutritional medium and temperature changes, there were statistically significant differences in the intensity of biofilm production, especially in the detected number of viable cells inside biofilms (log CFU, p < 0.005). Multiple biofilm-production genes, including polar flagella (filM) LuxR family (transcriptional regulators) and VapA family of histidine-kinase-associated genes, were sequenced from all studied isolates. Genetic differences based on geographical origin were not observed among the isolates. Significant variations in isolates' ability to form biofilms were observed, possibly due to epigenetic factors. The optimal temperature for biofilm formation of A. salmonicida subspecies salmonicida in scarce media was 8 °C, and the majority of isolates were not capable of biofilm formation at 25 °C without enriched nutrient media. [ABSTRACT FROM AUTHOR]

Industrial effluents, especially those containing dyes, have become the main cause of contamination of water resources. In this context, Brazilian bentonite/MgO composites, with excellent adsorptive properties, were prepared and investigated for their effectiveness in removing cationic and anionic dyes from aqueous solutions. The new adsorbents were obtained using Brazilian bentonites and MgO using the mechanochemical method followed by heat treatment (at 700 °C for 4 h). Different characterization techniques were used for the chemical, mineralogical, thermal, surface, and morphological analysis of the raw clays and the composites. The experimental adsorption isotherms were quantified under different conditions of initial concentration, contact time, pH, adsorbent dosage, and temperature variation to interpret the adsorption mechanism of the crystal violet (CV) and Congo red (CR) dyes. The modeling results were obtained from the empirical Sips equation and Pseudo Second Order (PSO) kinetics, indicating that the adsorption of molecules is a heterogeneous phenomenon that occurs in a monolayer on the surface (ns > 1), with the adsorption rate determined by chemisorption. The composites showed the best removal efficiency performance compared to the raw bentonites, with an increase of 12% for the CV dye and 46% for the CR dye. In addition, the qmax values obtained were 423.02 mg/g and 479.86 mg/g (AM01). This research underscores the potential of Brazilian bentonite/MgO composites as a promising solution for the removal of cationic and anionic dyes from water, offering hope for future applications in the field of environmental engineering and materials science. [ABSTRACT FROM AUTHOR]

Abstract\nHIGHLIGHTSDespite rapid advances in drug production, bacteria have adopted several drug resistance strategies, such as biofilm production. Therefore, research to develop and/or discover alternative antibacterial agents, such as natural products from plants becomes a necessity. Rosemary (Rosmarinus officinalis) is a well-known potent source of bioactive molecules with antibacterial and antibiofilm activities. The aim of this study was to determine the phytochemical composition, to evaluate the antibacterial and antibiofilm activities of Tunisian wild rosemary essential oils (REOs). Molecular docking tools were used to investigate the antibacterial effects of REOs bioactive molecules. GC-MS analysis revealed thirty-one compounds. The main components that define the chemotype were eucalyptol, camphor and α-pinene. The antibacterial activity evaluated by disc diffusion and the microdilution methods and the antibiofilm activity assessed by crystal violet test proved that REOs had strong activity against all the bacterial strains (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Salmonella typhimurium). The molecular docking study revealed that the investigated main compounds of REOs exhibited the best binding scores with two target proteins (Fts-Z and FimH). These results prove that REOs exhibited interesting biological activities as antibacterial and antibiofilm agents which could be explored for complementary medicine, food and pharmaceutical industries.Chemical composition of rosemary essential oils (REOs), analyzed by GC–MS, revealed the presence of 31 compounds which the main components that define the chemotype were eucalyptol (40.77–55.47%), camphor (5.42–18.65%) and α-pinene (9.88–13.83%)The antibacterial activity was evaluated by disc diffusion and micro-dilution method, and the anti-biofilm activity assessed using a crystal violet test was tested against two Gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis) and two Gram-negative strains (Escherichia coli and Salmonella typhimurium) and the results showed that all the tested REOs showed a strong activity against all bacterial strains.Furthermore, the studied REOs showed a potential anti-biofilm activity. Similarly, in the eradication activity, the majority of the tested REOs were able to eradicate the bacterial preinstalled biofilmsMolecular docking tools were performed to investigate the binding affinities and the interactions between the main components of REOs and two target proteins of a bacterial cell Fts-Z and FimH, in order to suggest a potent inhibitor against bacterial function. docking verification has shown a good affinity of some chemical compounds from REOs with target receptor protein explaining the assessed biological activitiesChemical composition of rosemary essential oils (REOs), analyzed by GC–MS, revealed the presence of 31 compounds which the main components that define the chemotype were eucalyptol (40.77–55.47%), camphor (5.42–18.65%) and α-pinene (9.88–13.83%)The antibacterial activity was evaluated by disc diffusion and micro-dilution method, and the anti-biofilm activity assessed using a crystal violet test was tested against two Gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis) and two Gram-negative strains (Escherichia coli and Salmonella typhimurium) and the results showed that all the tested REOs showed a strong activity against all bacterial strains.Furthermore, the studied REOs showed a potential anti-biofilm activity. Similarly, in the eradication activity, the majority of the tested REOs were able to eradicate the bacterial preinstalled biofilmsMolecular docking tools were performed to investigate the binding affinities and the interactions between the main components of REOs and two target proteins of a bacterial cell Fts-Z and FimH, in order to suggest a potent inhibitor against bacterial function. docking verification has shown a good affinity of some chemical compounds from REOs with target receptor protein explaining the assessed biological activities [ABSTRACT FROM AUTHOR]

This study systematically investigates the optimization of synthesis parameters for ternary layered double hydroxide (LDH) to achieve a pure phase and high crystallinity. The [Co0.52+Al0.253+Fe0.253+(OH)2].(CO32−)0.125.mH2O$[{\mathrm{Co}}_{0.5}^{2 + }{\mathrm{Al}}_{0.25}^{3 + }{\mathrm{Fe}}_{0.25}^{3 + }({\mathrm{OH}})_2 ].({\mathrm{CO}}_3^{2 - })_{0.125}.{\mathrm{m}}{\mathrm{H}}_2{\mathrm{O}}$, LDH is synthesized using the coprecipitation method and applied for wastewater treatment. The ternary LDH is synthesized at 60 °C for 24 h and exhibited maximum crystallinity with a crystallite size of 4 nm. The crystallinity index (CI) is a quantitative indicator of crystallinity, which is calculated using the X‐ray diffraction (XRD) method. The influence of reaction time on the structural characteristics of this LDH was thoroughly investigated, mainly focusing on achieving well‐crystalline LDH. Experimental results revealed a direct correlation between reaction time and crystallinity. This study highlights the significant influence of controlled synthesis and reaction time on producing high crystalline ternary LDH. The role of different parameters, such as solution pH, adsorbent dosage, contact time, and dye concentration, has been investigated. The adsorption isotherm data is analyzed using different isotherm models, which shows this material having a significant adsorption capacity of 82.92 mg/g for Congo Red dye. [ABSTRACT FROM AUTHOR]

In this study, we report the efficient removal of organic dyes from aqueous solutions using a newly synthesized pyrene-appended Zn(II)-based metal–organic framework (MOF), ZnSiF6Pyrene MOF, with the chemical formula C52H32F6N4SiZn·4(CHCl3). The MOF was synthesized through a facile method at room temperature using a dipyridylpyrene ligand and ZnSiF6 metal source, resulting in a highly crystalline structure with pyrene functional groups forming the framework. The synthesized MOF was characterized using various analytical techniques, including Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD) analysis, and scanning electron microscopy (SEM). Thermal stability was assessed using thermogravimetric analysis (TGA), while the surface area of the MOF was determined using a Brunauer–Emmett–Teller (BET) surface analyzer. Furthermore, the single-crystal X-ray diffraction (SCXRD) structure was studied to authenticate its solid-state structure. The as-synthesized MOF exhibited remarkable adsorption capacity towards various organic dyes, including Congo red (CR), rhodamine B (RhB), and methyl violet (MV), due to its ample surface area and strong π–π interactions between the pyrene moieties and dye molecules, as demonstrated by experimental and in silico docking studies. The photocatalytic degradation of MV dye was also investigated. Detailed trapping tests indicate that hydroxyl (˙OH) and superoxide (O2˙−) radicals are likely the primary active species responsible for the photodegradation of the dye under study. Furthermore, the photocatalytic property of the MOF was investigated under visible light irradiation, demonstrating excellent ability to generate singlet oxygen. This study highlights the potential of pyrene-appended Zn(II)-based MOFs as promising materials for environmental remediation applications. [ABSTRACT FROM AUTHOR]

The fabrication of cross-linked 1,10-diaminodecane-poly methyl methacrylate/carbon nanotubes/graphene nanocomposites PMMA/CNTs/GNP(a–c) has been executed effectively using a multistep chemical cross-linking reaction. The environmental response of the fabricated material has been extensively investigated. The synthesized PMMA@CNTs/GNP nanocomposite effectively removed crystal violet (CV) and methylene blue (MB) from the simulated textile wastewater solution. The comprehensive delineation of the prepared nanocomposite was examined using SEM, X-ray diffraction (XRD), and FTIR analysis. The outcomes revealed that adsorption capacity was influenced by six variables (e.g., contact duration, starting concentration, adsorbent mass, the effect of the solution pH, temperature, and the impact of KNO3). Additionally, studies on thermodynamics and isotherm have been published. The elimination process involves chemical adsorption based on the pseudo-second-order kinetics model. This model predicted that the maximal adsorption capacities of the MB and CV dyes would be 20.83 and 22.42 mg g−1, respectively, best fitting the experimental results. This work is a pilot case study highlighting the outstanding potential of PMMA/CNTs/GNP nanocomposites as materials for CV and MB dye elimination. [ABSTRACT FROM AUTHOR]

Rising concerns over water scarcity, driven by industrialization and urbanization, necessitate the need for innovative solutions for wastewater treatment. This study focuses on developing an eco‐friendly and cost‐effective biochar‐zeolite composite (BZC) adsorbent using waste materials—spent coffee ground biochar (CGB) and steel slag zeolite (SSZ). Initially, the biochar was prepared from spent coffee ground, and zeolite was prepared from steel slag; their co‐pyrolysis resulted in novel adsorbent material. Later, the physicochemical characteristics of the BZC were examined, which showed irregular structure and well‐defined pores. Dye removal studies were conducted, which indicate that BZC adsorption reach equilibrium in 2 h, exhibiting 95% removal efficiency compared to biochar (43.33%) and zeolite (74.58%). Moreover, the removal efficiencies of the novel BZC composite toward dyes methyl orange (MO) and crystal violet (CV) were found to be 97% and 99.53%, respectively. The kinetic studies performed with the dyes and phosphate with an adsorbent dosage of 0.5 g L−1 suggest a pseudo‐second‐order model. Additionally, the reusability study of BZC proves to be effective through multiple adsorption and regeneration cycles. Initially, the phosphate removal remains high but eventually decreases from 92% to 70% in the third regeneration cycle, highlighting the robustness of the BZC. In conclusion, this study introduces a promising, cost‐effective novel BZC adsorbent derived from waste materials as a sustainable solution for wastewater treatment. Emphasizing efficiency, reusability, and potential contributions to environmentally conscious water treatment, the findings highlight the composite's significance in addressing key challenges for the removal of toxic pollutants from the aqueous solutions. Practitioner Points: A novel biochar‐zeolite composite (BZC) material has been synthesized.Excellent removal of dyes by BZC (~95%) was achieved as compared to their counterpartsThe kinetic studies performed suggest a pseudo‐second‐order model.BZC proves to be highly effective for multiple adsorption studies.Excellent reusability showed potential as a robust adsorbent [ABSTRACT FROM AUTHOR]

Background: This study focused on evaluating the physiochemical characteristics and antibacterial activity of Octoprohibitin-encapsulated CNPs (Octoprohibitin-CNPs) against Acinetobacter baumannii. Methods: Octoprohibitin was encapsulated into CNPs via ionotropic gelation with carboxymethyl chitosan (CMC) and low molecular weight chitosan (CS). Octoprohibitin-CNPs were dispersed in phosphate-buffered saline and the release kinetic profile was determined. Then Octoprohibitin-CNPs were examined using field-emission transmission electron microscopy and physicochemical characterization was performed. Antibacterial activity of Octoprohibitin-CNPs against A. baumannii was evaluated. Biofilm inhibition and eradication assays were performed using the crystal violet (CV) staining-based method for biofilm quantification. Results: The average diameter, zeta potential, encapsulation efficiency, and loading capacity of Octoprohibitin-CNPs were 244.5 ± 21.97 nm, +48.57 ± 0.38 mV, and 85.7% and 34.2%, respectively. TEM analysis imaging revealed that Octoprohibitin-CNPs are irregularly shaped, with fewer aggregates than CNPs. Octoprohibitin-CNPs exhibited a biphasic release pattern, characterized by an initial rapid phase followed by a sustained release over time, extending up to 93.68 ± 6.48% total release until 96 h. In vitro, Octoprohibitin-CNPs showed lower cytotoxicity compared to Octoprohibitin alone. Time-kill kinetic and bacterial viability reduction assays showed Octoprohibitin-CNPs exhibited slightly higher antibacterial activity against A. baumannii than Octoprohibitin. Conclusions: Octoprohibitin-CNP-treated A. baumannii exhibited higher levels of morphological deviation, increased membrane permeability, and the production of reactive oxygen species, as well as antibiofilm activity with greater biofilm inhibition and eradication than Octoprohibitin. These findings show that Octoprohibitin-CNPs perform better against A. baumannii compared to Octoprohibitin alone. [ABSTRACT FROM AUTHOR]

Studies have shown that natural products can induce paraptosis in tumour cell lines. Paraptosis is characterized by cytoplasmic vacuolation arising from the endoplasmic reticulum (ER) and mitochondria. The mechanism of paraptosis is unclear; however, dysregulation of Ca2+ homeostasis is believed to affect paraptosis induction. This study investigated the mechanism of cell death induced by a phytocannabinoid ratio in the MCF7 breast cancer cell line. The crystal violet assay was used to detect changes in viability and morphology changes were investigated using light and transmission electron microscopy. Various inhibitors, fluorescent staining with high‐content screening, and Western blot analysis were used to investigate different cell death mechanisms. The phytocannabinoid ratio induced significant cell death and cytoplasmic vacuolation in MCF7 cells; however, no apoptosis, necrosis, autophagy, or ferroptosis was detected. Vacuolation induced by phytocannabinoid treatment was inhibited by cycloheximide, suggesting paraptosis induction. The mechanism of paraptosis induction was investigated, and it was found that treatment (1) induced ER dilation and mitochondrial swelling, (2) induced significant ER stress and mitochondrial Ca2+ overload and dysfunction, which appeared to be mediated by the voltage‐dependent anion channel, and (3) significantly impaired all mitochondrial metabolic pathways. The data demonstrated that paraptosis induced by the cannabinoid ratio was mediated by Ca2+ flux from the ER to the mitochondria. These findings highlight a novel mechanism of cannabinoid‐induced cell death and emphasize the anti‐cancer potential of cannabinoid ratios, which exhibited enhanced effects compared to individual cannabinoids. [ABSTRACT FROM AUTHOR]

Analytical studies of ancient Chinese handmade papers and paper-based materials have long faced challenges, due to the need for high-quality, scientifically sound data that can lead to suitable diagnostic criteria. This study applies Herzberg staining, micro-computed tomography (micro-CT), Raman spectroscopy, pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), and high-resolution mass spectrometry (HRMS) to five Hetian Administration Banknotes (HABs), a particular type of regional banknotes issued by Ma Hu-shan (1910–1954), a Hui warlord, in southern Xinjiang between 1933 and 1937. The results shed important insights into the use of fiber and dyes on HABs, revealing how locally handmade Sangpi (bark of the mulberry tree, Morus alba L.) papers and imported synthetic dyes (Rhodamine B, Methyl Violet 2B, Direct Black 38, and presumably Sudan II) were combined to serve the needs of the regional economy in southern Xinjiang during the 1930s. We conclude the paper by tentatively proposing guidelines for applying low- and high-resolution analytical methods to understand the manufacture and use of ancient Chinese handmade papers and paper-based materials. [ABSTRACT FROM AUTHOR]

Considering the correlation between survival microenvironment of E. faecalis and acidic pH value, this study aimed to investigate the potential of utilizing pH-responsive DMAEM monomers and their copolymers with resin-based root canal sealers to inhibit E. faecalis. Broth microdilution assay, crystal violet staining and qPCR were performed to evaluate antibacterial effects of DMAEM monomers against E. faecalis at different pH. Methacrylate-resin based root canal sealers were prepared and copolymerized with DMAEM. The flow, solubility, water sorption, apical sealing ability and cytotoxicity of sealers were investigated to optimize formulation. The anti -E. faecalis effects of DMAEM copolymers with sealers were evaluated by direct contact test, colony-forming unit counting and live/dead staining. DMAEM monomers inhibited the growth, biofilm formation and virulence factors expression of E. faecalis in a concentration- and pH-dependent manner. Incorporation of 1.25 % and 2.5 % DMAEM into experimental sealers would not affect the flowability, solubility and periapical sealing ability (P > 0.05), but increased the water sorption of sealers (P < 0.01). Cells viability was higher than 90 % in both 1.25 % and 2.5 % DMAEM groups at pH 7.0. DMAEM copolymers with sealers reduced E. faecalis counts, inhibited biofilm formation and decreased live cells within the biofilm in response to pH values. DMAEM monomers and their copolymers with resin-based sealers possessed antibacterial and antibiofilm effects on E. faecalis in response to pH values. DMAEM is promising to inhibit intraradicular E. faecalis in response to its acidic survival environment and maintain low cytotoxicity under neutral conditions, ensuring their biosafety in case of inadvertent entry into periapical tissues. [Display omitted] • DMAEM monomers inhibit E. faecalis in response to acidic pH values. • DMAEM incorporated resin-based root canal sealers achieve good physical properties. • DMAEM incorporated sealers maintain good biocompatibilities at neutral pH. • DMAEM incorporated sealers inhibit E. faecalis in response to acidic pH values. [ABSTRACT FROM AUTHOR]

The use of magnetic nanomaterials (MNPs) as adsorbents to eliminate pollution causing dyes from water has attracted substantial attention in recent years because they can be easily isolated and reused. In this work, core–shell Fe3O4@SiO2 MNPs in which magnetic Fe3O4 NPs as a core enclosed with a thick SiO2 shell were successfully synthesized by chemical co–precipitation followed by hydrolysis and condensation of alkoxysilanes in a mixture of ammonia, ethanol and water. The formation of core–shell Fe3O4@SiO2 MNPs has been characterized by TEM, TEM-EDS, XRD, FT-IR and VSM. TEM characterization revealed that several Fe3O4 NPs (around 10 nm) aggregated to form a Fe3O4 magnetic core and surrounded by an uniform SiO2 shell of 40-50 nm thickness to obtain Fe3O4@SiO2 magnetic core–shell NPs. As synthesized core–shell NPs were employed as adsorbent for elimination of two cationic toxic dyes, crystal violet (CV) and malachite green (MG) from aqueous solutions. Further, different adsorption parameters such as pH, adsorbent dosage and contact times of the dyes were found to enhance the adsorption of cationic dyes. At neutral pH 7 the cationic dyes could be speedily removed from aqueous solution with high efficiency. It has been observed that 0.35 g of adsorbent dosage is sufficient for 95% of dye removal efficiency. The contact time is optimised for 20 min for both the dyes. The Langmuir model adsorption isotherm is best suitable which indicates that the cationic dyes adsorption behaviour of Fe3O4@SiO2 is a homogeneous monolayer chemisorption process. The adsorptive binding of CV/MG with Fe3O4@SiO2 was directed through electrostatic interactions. Moreover, the magnetic adsorbents could be easily reused and regenerated with almost no adsorption capability is significantly reduced up to 5 cycles. So, the Fe3O4@SiO2 is an efficient and reusable adsorbent for rapid and removal of cationic dyes from the aqueous solution. [ABSTRACT FROM AUTHOR]

Currently, water pollution caused by dyes is a serious problem since they are toxic and carcinogenic to living beings. To reduce the presence of these contaminants, natural adsorbents have been considered as they are easy to obtain, inexpensive, and have high removal efficiency. In this work, the adsorption process using natural brushite (nDCPD) was studied for the removal of phenol red (PR), achieving a removal rate of 99.15% and an adsorption capacity of 82.24 mg/g, and gentian violet (GV), achieving a removal rate of 97.03% and an adsorption capacity of 74.22 mg/g. Equilibrium adsorption occurs for both dyes in multiple layers on the surface. The adsorption process is spontaneous for both dyes. The kinetics of the adsorption process involve using a single active site on the surface for PR adsorption, while for GV, two active sites on the surface are required. Analysis via FTIR, EDS, and XRD revealed various mechanisms that intervene in the adsorption process of both dyes on the surface of nDCPD, such as electrostatic forces, functional groups, physisorption, and ion exchange. [ABSTRACT FROM AUTHOR]

Removal of toxic pollutants is of the greatest concerns facing wastewater treatment. In this study, a chemical modification method was used to prepare the maleic anhydride-modified water hyacinth (MA-EC) for the removal of methylene blue (MB) and methyl violet (MV) from water. The maleic anhydride-modified water hyacinth biosorbent was characterized and adsorption experiments were conducted. The prepared MA-EC demonstrated considerable adsorptive efficiency toward MV and MB. It was confirmed that the maximum adsorptive capacities were 1373.58 and 434.70 mg/g for MV and MB, respectively. The adsorptive data were also fitted using Langmuir and Freundlich isotherms, and the results showed that the Langmuir isotherm adsorption model could better describe the adsorptive process. Adsorption–desorption cycling experiments demonstrated that the MA-EC adsorbent had good reusability, with adsorptive capacities of 538.88 mg/g for MV and 215.56 mg/g for MB after four cycles of desorption–adsorption. [ABSTRACT FROM AUTHOR]

In this work, sunflower (Helianthus annuus) seed pericarp (SSPC) was converted into mesoporous activated carbon (SSPCAC) via microwave-assisted ZnCl2 activation to be a cost-effective and renewable adsorbent for crystal violet (CV) dye removal. The obtained SSPCAC exhibits a preferable surface area of 641 m2/g with mesoporous characteristics. A statistical optimization by Box-Behnken Design (BBD) with Response Surface Methodology (RSM) was adopted to achieve the optimal operational conditions for CV dye including SSPCAC dose, solution pH, and contact time. Moreover, desirability functions confirm the maximum CV removal of 91% was attended at SSPC-AC dose (0.083 g/100 mL), solution pH (9.8), and contact time (5.38 min). Thus, the equilibrium data were best described by the Langmuir isotherm model with a maximum adsorption capacity of 111.9 mg/g at 25 0C. Thus, the adsorption kinetics were well described by a pseudo-second order (PSO) model. The adsorption mechanism of CV onto SSPCAC surface can be assigned to the electrostatic attraction, hydrogen bonding, pore filling, and pi-pi interactions. This research highlights the potential of sunflower seed pericarp as a renewable precursor for activated carbon production with promising applications in toxic dye removal from wastewater. [ABSTRACT FROM AUTHOR]

The present study describes the facile synthesis of graphene oxide (GO) and GO/carboxymethyl tamarind kernel gum (CMTKG)‐based hydrogel composite. The synthesized GO/CMTKG/PAM hydrogel composite was applied as an adsorbent for the selective sequestration of toxic crystal violet (CV) and methylene blue (MB) from an aqueous medium. The impact of various controlling parameters such as contact time, pH, concentration, adsorbent dosage, and temperature was studied. The experimental data obtained from the isotherm and kinetics modeling showed a good correlation with the Langmuir isotherm and pseudo‐second‐order kinetics model, respectively. The optimized concentration of dye was 40 mg L−1 for CV and 20 mg L−1 for MB, and the adsorption capacity (qmax) was calculated to be 111 mg g−1 for CV dye and 25 mg g−1 for MB dye. The synthesized adsorbent exhibits excellent recyclability for dye uptake after six consecutive cycles. Furthermore, the simultaneous adsorption of CV and MB from the binary system was carried out to ascertain the utility of the adsorbent in a wide range of adsorption systems. The adsorbent was also found to act as a proficient adsorbent in various water samples. These results demonstrated that synthesized hydrogel can be successfully applied as an adsorbent for the sequestration of dye effluents in real‐time applications. Highlights: Hydrogel composite was successfully synthesized via a free radical mechanism.It is an efficient adsorbent for removing cationic dyes from aqueous solutions.It shows selectivity towards cationic dyes and works in a binary mixture of cationic dyes.It shows good removal efficacy in different water samples, including real wastewater samples.It also shows proficient removal efficacy after six consecutive regeneration cycles. [ABSTRACT FROM AUTHOR]

Facile, controllable and efficient SERS substrate preparation has always been the focus project in the SERS field, especially the solid-state nanoarray substrate. Herein, a simple and convenient method for preparing a series of homogeneous Ag-stepped nanocone arrays (Ag-SNCAs) using polymer nanocompression printing is presented. By analyzing the 1162cm−1 characteristic peak of crystal violet (CV), the relative standard deviation (RSD) of the Raman intensity was only 4.71%. The detection limit of malachite green (MG) reached 0.001ppm, and it also has good SERS detection results for drug molecules such as melamine, methadone, morphine, methamphetamine and thiabendazole. This work provides a large area uniform and controllable preparation method of sharp cone nanostructure array, which has important application in plasmonic photocatalysis and deep light field regulations. [ABSTRACT FROM AUTHOR]

Background: Bioinspired nanomaterials have widely been employed as suitable alternatives for controlling biofilm and pathogens due to their distinctive physico-chemical properties. Methodology: This study explored the antibiofilm as well as photocatalytic potential of silver (Ag) nanoparticles (NPs) synthesized using the cell-free supernatant of Lactobacillus acidophilus for the disinfection of multi-drug-resistant (MDR) strains of enteroaggregative E. coli (EAEC), Salmonella Typhimurium, S. Enteritidis and methicillin-resistant Staphylococcus aureus (MRSA) on exposure to LED light. In addition, the removal of toxic cationic dyes i.e., methylene blue (MB), rhodamine B (RhB) and crystal violet (CV) was explored on exposure to sunlight, LED and UV lights. Results: Initially, the synthesis of AgNPs was verified using UV- Vis spectroscopy, X-ray diffraction and transmission electron microscopy. The synthesized AgNPs exhibited MIC and MBC values of 7.80 and 15.625 µg/mL, respectively. The AgNPs exhibited significant inhibition (P < 0.001) in the biofilm-forming ability of all the tested MDR isolates. On exposure to LED light, the AgNPs could effectively eliminate all the tested MDR isolates in a dose-dependent manner. While performing photocatalytic assays, the degradation of RhB was observed to be quite slower than MB and CV irrespective of the tested light sources. Moreover, the sunlight as well as UV light exhibited better photodegradation capacity than LED light. Notwithstanding the light sources, RhB followed zero-order kinetics; however, MB and CV followed primarily second-order kinetics. Conclusion: The green synthesized AgNPs were found to be an effective photocatalytic as well as antifouling candidate that could be applied in therapeutics and wastewater treatment. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa biofilms shield the bacteria from antibiotics and the body's defenses, often leading to chronic infections that are challenging to treat. This study aimed to assess the impact of sub-lethal doses of antimicrobial photodynamic inactivation (sAPDI) utilizing carbon dots (CDs) derived from gentamicin and imipenem on biofilm formation and the expression of genes (pelA and pslA) associated with P. aeruginosa biofilm formation. The anti-biofilm effects of sAPDI were evaluated by exposing P. aeruginosa to sub-minimum biofilm inhibitory concentrations (sub-MBIC) of CDsGEN-NH2, CDsIMP-NH2, CDsGEN-IMP, and CDsIMP-GEN, combined with sub-lethal UVA light irradiation. Biofilm formation ability was assessed by crystal violet (CV) assay and enumeration method. Additionally, the impact of sAPDI on the expression of pelF and pslA genes was evaluated using real-time quantitative polymerase chain reaction (RT-qPCR). Compared to the control group, the sAPDI treatment with CDsGEN-NH2, CDsIMP-NH2, CDsGEN-IMP, and CDsIMP-GEN resulted in a significant reduction in biofilm activity of P. aeruginosa ATCC 27853 (P < 0.0001). The CV assay method demonstrated reductions in optical density of 83.70%, 81.08%, 89.33%, and 75.71%, while the CFU counting method showed reductions of 4.03, 3.76, 4.39, and 3.21 Log10 CFU/mL. qRT-PCR analysis revealed decreased expression of the pelA and pslA genes in P. aeruginosa ATCC 27853 following sAPDI treatment compared to the control group (P < 0.05). The results indicate that sAPDI using CDs derived from gentamicin and imipenem can decrease the biofilm formation of P. aeruginosa and the expression of the pelA and pslA genes associated with its biofilm formation. [ABSTRACT FROM AUTHOR]

The textile industry's waste often contains excessive amounts of crystal violet (CV), leading to environmental concerns. Graphene oxide has been studied as a promising adsorbent for removing crystal violet, a cationic dye, from aqueous solutions. The study involved a comprehensive analysis of various experimental parameters, including initial concentration, pH, adsorbent mass, contact time, and temperature. Graphene oxide underwent thorough analysis using Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), and specific surface area determination via the Brunauer–Emmett–Teller (BET) method. Energy‐dispersive X‐ray spectroscopy (EDS) was also employed. This study aimed to optimize the synthesis yield of graphene oxide from graphite using the Hummers method and response surface methodology (RSM), achieving a yield of 106.14% with 5 g of KMnO4 and 1 g of NaNO3 for 8 hours. The graphene oxide was analyzed via FTIR, XRD, SEM, BET, pHpzc, and EDS. Optimal conditions for maximal adsorption included 0.016 g of graphene oxide, 18 minutes of contact time, pH 10, and a temperature of 25°C, resulting in a 97.38% reduction in crystal violet with a monolayer adsorption capacity of 470.78 mg/g. Kinetic data were best fitted by the pseudosecond‐order model, and the Langmuir isotherm accurately depicted adsorption. Thermodynamic analysis indicated spontaneous (ΔG° < 0) and exothermic (ΔH° < 0) crystal violet adsorption. Density functional theory (DFT) explored interactions between graphene oxide and crystal violet, supporting experimental findings and confirming graphene oxide's efficacy as an adsorbent for crystal violet removal from aqueous solutions. [ABSTRACT FROM AUTHOR]

Herein, a novel hydrogel (HG-cl-poly(AA)) was synthesized by grafting acrylic acid (AA) onto Hing gum (HG) using methylene-bis-acrylamide (MBA) as a cross-linker and ammonium persulfate (APS) as an initiator in a hot air oven. The percentage swelling of the hydrogel was examined by optimizing various reaction parameters to ensure its maximum swelling percentage. The formation of crosslinked networks was confirmed using Fourier-Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA) techniques. The surface area and hydrophilicity of the prepared hydrogel were determined using Brunauer–Emmett–Teller analyzer and wettability studies, demonstrating a clear correlation with adsorption. The adsorption of crystal violet (CV) dye on the prepared hydrogel was studied via a batch adsorption system based on the amount of adsorbent, immersion time, pH level, and initial dye concentration. The prepared hydrogel showed a 99% removal rate and an excellent adsorption capacity of 492.61mg/g due to the electrostatic, H-bonding, and dipole–dipole interactions between the adsorbent surface and dye molecules. The results were further analyzed using the Langmuir, Freundlich, and Tempkin isotherm models. The study suggests consistency with the pseudo-second-order kinetic model (R2=0.998), further supported by the best data fit with the Langmuir isotherm model (R2=0.991). The thermodynamic study results indicated that the adsorption process is endothermic and spontaneous. Regeneration (desorption) studies showed that the prepared hydrogel could remove CV dye from an aqueous solution and maintain the highest adsorption capacity even after multiple adsorption and desorption cycles. Therefore, the prepared HG-cl-poly(AA) hydrogel could be a potential adsorbent for dye removal and have an admirable capacity for cleaning the aquatic environment. [ABSTRACT FROM AUTHOR]

Metal organic framework (MOF) materials have attracted widespread interests because of their potential application prospects in the field of heterogeneous catalysis. In this work, a cobalt-based MOF Co3-btca was developed as an efficient heterogeneous catalyst for the degradation of organic dye pollutants in water by activating peroxymonosulfate (PMS). Detailed characterizations showcased that the as-prepared nitrogen-rich Co-MOF Co3-btca possessed micron size and good stability. In the presence of both Co3-btca and PMS, the methyl violet (MV) degradation rate reached 99.78% within 9 min, while the rhodamine B (RhB) degradation rate reached 99.58% within 15 min. The effect of dye concentrations, reaction temperature, PMS and catalyst dosages on degradation reactions was studied. More importantly, successive degradation experiments demonstrated that the as-prepared Co3-btca catalyst possessed good stability with easy recycling for eliminating organic contaminants from wastewater. Radical trapping measurements confirmed that SO4−˙ and ˙OH radicals were the main active species for the removal of organic dyes. Moreover, we speculated the possible degradation mechanism of organic dyes. These features make Co3-btca a stable heterogeneous catalyst for the efficient activation of PMS in environmental remediation. [ABSTRACT FROM AUTHOR]

Klebsiella pneumoniae is a pathogen that commonly causes hospital‐acquired infections. Bacterial biofilms are structured bacterial communities that adhere to the surface of objects or biological tissues. In this study, we investigated the genome homology and biofilm formation capacity of ESBL‐producing K. pneumoniae. Thirty ESBL‐producing K. pneumoniae isolates from 25 inpatients at Ruijin Hospital, Shanghai, were subjected to pulsed‐field gel electrophoresis (PFGE) to estimate genomic relatedness. Based on the chromosomal DNA patterns we obtained, we identified 21 PFGE profiles from the 30 isolates, eight of which had high homology indicating that they may have genetic relationships and/or potential clonal advantages within the hospital. Approximately 84% (21/25) of the clinical patients had a history of surgery, urinary tract catheterization, and/or arteriovenous intubation, all of which may have increased the risk for nosocomial infections. Biofilms were observed in 73% (22/30) of the isolates and that strains did not express type 3 fimbriae did not have biofilm formation capacity. Above findings indicated that a high percentage of ESBL‐producing K. pneumoniae isolates formed biofilms in vitro and even though two strains with cut‐off of PFGE reached 100% similarity, they generated biofilms differently. Besides, the variability in biofilm formation ability may be correlated with the expression of type 3 fimbriae. Thus, we next screened four ESBL‐producing K. pneumoniae isolates (Kpn5, Kpn7, Kpn11, and Kpn16) with high homology and significant differences in biofilm formation using PFGE molecular typing, colony morphology, and crystal violet tests. Kpn7 and Kpn16 had stronger biofilm formation abilities compared with Kpn5 and Kpn11. The ability of above four ESBL‐producing K. pneumoniae isolates to agglutinate in a mannose‐resistant manner or in a mannose‐sensitive manner, as well as RNA sequencing‐based transcriptome results, showed that type 3 fimbriae play a significant role in biofilm formation. In contrast, type 1 fimbriae were downregulated during biofilm formation. Further research is needed to fully understand the regulatory mechanisms which underlie these processes. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus infections are the primary causes of morbidity, and mortality, particularly in immuno-compromised individuals. S. aureus associated infections are acquired from community, as well as hospital settings, and difficult to treat because of the emerging resistance against available antibiotics. One of the key factors of its resistance is the biofilm formation, which can be targeted to treat S. aureus-induced infections. Currently, there is no drug available that function by targeting the biofilm. This unmet need demands the discovery of drug candidates against S. aureus biofilm. The present study was designed to evaluate coumarin derivatives 1–21 against S. aureus biofilm. The 96-well plate crystal violet assay was employed for the quantification of biofilm. Results showed that the coumarin derivatives 2–4, 10, and 17 possess potent antibiofilm activity, with MBIC values between 25–100 μg/mL. The results were further confirmed through atomic force microscopy (AFM), scanning electron (SEM), and fluorescence microscopic studies. The quantitative RT-PCR analysis revealed the downregulation of biofilm associated genes, icaA and icaD. These coumarin derivatives were also found to be non-cytotoxic to fibroblasts. This study, therefore, identifies the antibiofilm potential of coumarin derivatives that will pave the way for further research on these derivatives. [ABSTRACT FROM AUTHOR]