Fabrication and characterization of a new eco-friendly sulfonamide-chitosan derivative with enhanced antimicrobial and selective cytotoxicity properties

Chitosan (CH) exhibits low antimicrobial activity. This study addresses this issue by modifying the chitosan with a sulfonamide derivative, 3-(4-(N,N-dimethylsulfonyl)phenyl)acrylic acid. The structure of the sulfonamide-chitosan derivative (DMS-CH) was confirmed using Fourier transform infrared spectroscopy and Nuclear magnetic resonance. The results of scanning electron microscopy, thermal gravimetric analysis, and X-ray diffraction indicated that the morphology changed to a porous nature, the thermal stability decreased, and the crystallinity increased in the DMS-CH derivative compared to chitosan, respectively. The degree of substitution was calculated from the elemental analysis data and was found to be moderate (42%). The modified chitosan exhibited enhanced antimicrobial properties at low concentrations, with a minimum inhibitory concentration (MIC) of 50 µg/mL observed for B. subtilis and P. aeruginosa, and a value of 25 µg/mL for S. aureus, E. coli, and C. albicans. In the case of native chitosan, the MIC values doubled or more, with 50 µg/mL recorded for E. coli and C. albicans and 100 μg/mL recorded for B. subtilis, S. aureus, and P. aeruginosa. Furthermore, toxicological examinations conducted on MCF-7 (breast adenocarcinoma) cell lines demonstrated that DMS-CH exhibited greater toxicity (IC50 = 225.47 μg/mL) than pure CH, while still maintaining significant safety limits against normal lung fibroblasts (WI-38). Collectively, these results suggest the potential use of the newly modified chitosan in biomedical applications.

An Eco-Friendly Approach Utilizing Green Synthesized Titanium Dioxide Nanoparticles for Leather Conservation against a Fungal Strain, Penicillium expansum AL1, Involved in the Biodeterioration of a Historical Manuscript

The main hypothesis of the present research is investigating the efficacy of titanium oxide nanoparticles (TiO₂-NPs) to prevent the growth of fungal strains when applied on leather under an experimental study. Therefore, fifteen fungal strains were isolated from a deteriorated historical manuscript (papers and leathers) and identified by traditional methods and ITS sequence analysis, including Aspergillus chevalieri (one isolate), A. nidulans (two strains), A. flavus (four strains), A. cristatus (one strain), A. niger (one strain), Paecilomyces fulvus (two strains), Penicillium expansum (two strains), and P. citrinum (two strains). The enzymes cellulase, amylase, pectinase, and gelatinase, which play a crucial role in biodegradation, were highly active in these fungal strains. TiO₂-NPs were formed using the cell-free filtrate of the probiotic bacterial strain, Lactobacillus plantarum, and characterized. Data showed that the TiO₂-NPs were successfully formed with a spherical shape and anatase phase with sizes of 2-8 nm. Moreover, the EDX analysis revealed that the Ti and O ions occupied the main component with weight percentages of 41.66 and 31.76%, respectively. The in vitro cytotoxicity of TiO₂-NPs toward two normal cell lines, WI38 and HFB4, showed a low toxicity effect against normal cells (IC₅₀ = 114.1 ± 8.1µg mL^-1 for Wi38, and 237.5 ± 3.5µg mL^-1 for HFB4). Therefore, concentrations of 100 μg mL^-1 were used to load on prepared leather samples before inoculation with fungal strain P. expansum AL1. The experimental study revealed that the loaded TiO₂-NPs have the efficacy to inhibit fungal growth with percentages of 73.2 ± 2.5%, 84.2 ± 1.8%, and 88.8 ± 0.6% after 7, 14, and 21 days, respectively. Also, the analyses including SEM, FTIR-ART, color change, and mechanical properties for leather inoculated with fungal strain AL1 in the absence of NPs showed high damage aspects compared to those inoculated with fungal strains in the presence of TiO₂-NPs.

Synthesis, characterization, and biological evaluation of new chitosan derivative bearing diphenyl pyrazole moiety

This work reports the synthesis of a new pyrazole derivative by reacting 5-amino-1,3-diphenyl pyrazole with succinic anhydride and bearing the product chemically on the chitosan chains via amide linkage to achieve a new chitosan derivative (DPPS-CH). The prepared chitosan derivative was analyzed by IR, NMR, elemental analysis, XRD, TGA-DTG, and SEM. As compared with chitosan, DPPS-CH showed an amorphous and porous structure. Coats-Redfern results showed that the thermal activation energy for the first decomposition of DPPS-CH is 43.72 KJ mol^-1 lower than that required for chitosan (88.32 KJ mol^-1), indicating the accelerating effect of DPPS on the thermal decomposition of DPPS-CH. The DPPS-CH manifested a powerful wide spectrum antimicrobial potential against pathogenic gram-positive and gram-negative bacteria and Candida albicans at minute concentrations (MIC = 50 μg mL^-1) compared to chitosan (MIC = 100 μg mL^-1). The MTT assay proved the toxic properties of DPPS-CH against a cancer cell line (MCF-7) at a minute concentration (IC50 = 15.14 μg mL^-1) while affecting normal cells (WI-38) at seven times this concentration (IC50 = 107.8 μg mL^-1). According to the current findings, the chitosan derivative developed in this work appears to be a promising material for use in biological domains.

Exploring the antimicrobial, antioxidant, anticancer, biocompatibility, and larvicidal activities of selenium nanoparticles fabricated by endophytic fungal strain Penicillium verhagenii

Herein, four endophytic fungal strains living in healthy roots of garlic were used to produce selenium nanoparticles (Se-NPs) via green synthesis. Penicillium verhagenii was found to be the most efficient Se-NPs producer with a ruby red color that showed maximum surface plasmon resonance at 270 nm. The as-formed Se-NPs were crystalline, spherical, and well-arranged without aggregation, and ranged from 25 to 75 nm in size with a zeta potential value of -32 mV, indicating high stability. Concentration-dependent biomedical activities of the P. verhagenii-based Se-NPs were observed, including promising antimicrobial activity against different pathogens (Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Candida albicans, C. glabrata, C. tropicalis, and C. parapsilosis) with minimum inhibitory concentration (MIC) of 12.5-100 µg mL^-1. The biosynthesized Se-NPs showed high antioxidant activity with DPPH-scavenging percentages of 86.8 ± 0.6% at a concentration of 1000 µg mL^-1 and decreased to 19.3 ± 4.5% at 1.95 µg mL^-1. Interestingly, the Se-NPs also showed anticancer activity against PC3 and MCF7 cell lines with IC₅₀ of 225.7 ± 3.6 and 283.8 ± 7.5 µg mL^-1, respectively while it is remaining biocompatible with normal WI38 and Vero cell lines. Additionally, the green synthesized Se-NPs were effective against instar larvae of a medical insect, Aedes albopictus with maximum mortality of 85.1 ± 3.1, 67.2 ± 1.2, 62.10 ± 1.4, and 51.0 ± 1.0% at a concentration of 50 µg mL^-1 for I, II, III, and IV-instar larva, respectively. These data highlight the efficacy of endophytic fungal strains for cost-effective and eco-friendly Se-NPs synthesis with different applications.

Antifungal Activity of Cell-Free Filtrate of Probiotic Bacteria Lactobacillus rhamnosus ATCC-7469 against Fungal Strains Isolated from a Historical Manuscript

Herein, twelve fungal strains were isolated from a deteriorated historical manuscript dated back to the 18th century. The obtained fungal strains were identified, using the traditional method and ITS sequence analysis, as Cladosporium herbarum (two strains), Aspergillus fumigatus (five strains), A. ustus (one strain), A. flavus (two strains), A. niger (one strain), and Penicillium chrysogenum (one strain). The ability of these fungal strains to degrade the main components of the paper was investigated by their activity to secrete extracellular enzymes including cellulase, amylase, gelatinase, and pectinase. The cell-free filtrate (CFF) ability of the probiotic bacterial strain Lactobacillus rhamnosus ATCC-7469 to inhibit fungal growth was investigated. The metabolic profile of CFF was detected by GC-MS analysis, which confirmed the low and high molecular weight of various active chemical compounds. The safe dose to be used for the biocontrol of fungal growth was selected by investigating the biocompatibility of CFF and two normal cell lines, Wi38 (normal lung tissue) and HFB4 (normal human skin melanocyte). Data showed that the CFF has a cytotoxic effect against the two normal cell lines at high concentrations, with IC₅₀ values of 525.2 ± 9.8 and 329.1 ± 4.2 µg mL^-1 for Wi38 and HFB4, respectively. The antifungal activity showed that the CFF has promising activity against all fungal strains in a concentration-dependent manner. The highest antifungal activity (100%) was recorded for a concentration of 300 µg mL^-1 with a zone of inhibition (ZOI) in the ranges of 21.3 ± 0.6 to 17.7 ± 0.5 mm. At a concentration of 100 µg mL^-1, the activity of CFF remained effective against all fungal strains (100%), but its effectiveness decreased to only inhibit the growth of eight strains (66%) out of the total at 50 µg mL^-1. In general, probiotic bacterial strains containing CFF are safe and can be considered as a potential option for inhibiting the growth of various fungal strains. It is recommended that they be used in the preservation of degraded historical papers.

Green Synthesis of Zinc Oxide Nanoparticles Using an Aqueous Extract of Punica granatum for Antimicrobial and Catalytic Activity

The peel aqueous extract of Punica granatum was utilized to fabricate zinc oxide nanoparticles (ZnO-NPs) as a green approach. The synthesized NPs were characterized by UV-Vis spectroscopy, Fourier transform infrared (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy, which was attached to an energy dispersive X-ray (SEM-EDX). Spherical, well arranged, and crystallographic structures of ZnO-NPs were formed with sizes of 10-45 nm. The biological activities of ZnO-NPs, including antimicrobial and catalytic activity for methylene blue dye, were assessed. Data analysis showed that the antimicrobial activity against pathogenic Gram-positive and Gram-negative bacteria, as well as unicellular fungi, was observed to occur in a dose-dependent manner, displaying varied inhibition zones and low minimum inhibitory concentration (MIC) values in the ranges of 6.25-12.5 µg mL^-1. The degradation efficacy of methylene blue (MB) using ZnO-NPs is dependent on nano-catalyst concentration, contact time, and incubation condition (UV-light emission). The maximum MB degradation percentages of 93.4 ± 0.2% was attained at 20 µg mL^-1 after 210 min in presence of UV-light. Data analysis showed that there is no significant difference between the degradation percentages after 210, 1440, and 1800 min. Moreover, the nano-catalyst showed high stability and efficacy to degrade MB for five cycles with decreasing values of 4%. Overall, P. granatum-based ZnO-NPs are promising tools to inhibit the growth of pathogenic microbes and degradation of MB in the presence of UV-light emission.

Mechanistic In Situ ATR-FTIR Studies on the Adsorption and Desorption of Major Intermediates in CO2 Electrochemical Reduction on CuO Nanoparticles

Increasing levels of carbon dioxide (CO₂) from human activities is affecting the ecosystem and civilization as we know it. CO₂ removal from the atmosphere and emission reduction by heavy industries through carbon capture, utilization, and storage (CCUS) technologies to store or convert CO₂ to useful products or fuels is a popular approach to meet net zero targets by 2050. One promising process of CO₂ removal and conversion is CO₂ electrochemical reduction (CO₂ER) using metal and metal oxide catalysts, particularly copper-based materials. However, the current limitations of CO₂ER stem from the low product selectivity of copper electrocatalysts due to existing knowledge gaps of the reaction mechanisms using surfaces that normally have native oxide layers. Here, we report systematic control studies of the surface interactions of major intermediates in CO₂ER, formate, bicarbonate, and acetate, with CuO nanoparticles in situ and in real time using attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR). Spectra were collected as a function of concentration, pH, and time in the dark and the in absence of added electrolytes. Isotopic exchange experiments were also performed to elucidate the type of surface complexes from H/D exchange. Our results show that the organics and bicarbonate form mostly outer-sphere complexes mediated by hydrogen bonding with CuO nanoparticles with Gibbs free energy of adsorption of about -25 kJ mol^-1. The desorption kinetics of the surface species indicated relatively fast and slow regions reflective of the heterogeneity of sites that affect the strength of hydrogen bonding. These results suggest that hydrogen bonding, whether intermolecular or with surface sites on CuO nanoparticles, might be playing a more important role in the CO₂ER reaction mechanism than previously thought, contributing to the lack of product selectivity.

Fungal Biodeterioration of a Historical Manuscript Dating Back to the 14th Century: An Insight into Various Fungal Strains and Their Enzymatic Activities

This study aims to assess the deterioration aspects of a historical manuscript dating back to the 14th century that was deposited in the Library of the Arabic Language Academy, Cairo, Egypt. The study aims at the exploration of the role of various fungal strains that had colonized this deteriorated manuscript in its biodeterioration through their efficacy in the secretion of various hydrolytic enzymes. To evaluate the deterioration, various techniques, including visual inspection, attenuated total reflectance Fourier transform infrared (ATR-FTIR), scanning electron microscopy (SEM), X-Ray diffraction analysis (XRD), color change, and pH value, were utilized. The fungal strains linked to the historical document were isolated, identified, and evaluated for their deterioration activities. The findings demonstrate that the manuscript exhibits a variety of deterioration signs including color change, brittleness and weakness, erosion, and removal of the grain surface pattern in leather binding. According to the ATR-FTIR, the chemical composition of the historical paper and leather underwent some alterations. The historical paper has a lower level of cellulose crystallinity than the control sample. Penicillium chrysogenum (two isolates), P. citrinum (four isolates), Aspergillus ustus (three isolates), A. terreus (two isolates), A. chinensis (one isolate), Paecilomyces sp. (one isolate), and Induratia sp. (one isolate) were among the fourteen fungal strains identified as being associated with the historical manuscript. These fungal strains produced several hydrolytic enzymes with high activity, such as cellulase, amylase, gelatinase, and pectinase, which play a key role in biodegradation.

Alleviate the Drought Stress on Triticum aestivum L. Using the Algal Extracts of Sargassum latifolium and Corallina elongate Versus the Commercial Algal Products

Herein, two seaweed extracts (Sargassum latifolium and Corallina elongate), and two commercial seaweed products (Canada power and Oligo-X) with a concentration of 5% were used to alleviate the drought stress on wheat plants. The extract of C. elongate had the highest capacity to ameliorate the deleterious effects of water scarcity followed by S. latifolium and the commercial products. The drought stress reduced wheat shoots length and the contents of pigments (chlorophyll and carotenoids), carbohydrates, and proteins. While the highest increment in the total carbohydrates and protein contents of the wheat shoot after two stages, 37-and 67-days-old, were noted in drought-stressed plants treated with C. elongate extract with values of (34.6% and 22.8%) and (51.9% and 39.5%), respectively, compared to unstressed plants. Decreasing the activity of antioxidant enzymes, peroxidase, superoxidase dismutase, and polyphenol oxidase in drought-stressed plants treated with algal extracts indicated amelioration of the response actions. Analysis of phytohormones in wheat plants exhibited increasing GA3 and IAA contents with percentages of (20.3-13.8%) and (72.7-25%), respectively. Interestingly, all morphological and metabolic characteristics of yield were improved due to the algal treatments compared with untreated drought-stressed plants. Overall, the algal extracts, especially those from seaweed of C. elongate, could represent a sustainable candidate to overcome the damage effects of water deficiency in the wheat plant.

Mycosynthesis, Characterization, and Mosquitocidal Activity of Silver Nanoparticles Fabricated by Aspergillus niger Strain

Herein, silver nanoparticles (Ag-NPs) were synthesized using an environmentally friendly approach by harnessing the metabolites of Aspergillus niger F2. The successful formation of Ag-NPs was checked by a color change to yellowish-brown, followed by UV-Vis spectroscopy, Fourier transforms infrared (FT-IR), Transmission electron microscopy (TEM), and X-ray diffraction (XRD). Data showed the successful formation of crystalline Ag-NPs with a spherical shape at the maximum surface plasmon resonance of 420 nm with a size range of 3–13 nm. The Ag-NPs showed high toxicity against I, II, III, and IV instar larvae and pupae of Aedes aegypti with LC50 and LC90 values of 12.4–22.9 ppm and 22.4–41.4 ppm, respectively under laboratory conditions. The field assay exhibited the highest reduction in larval density due to treatment with Ag-NPs (10× LC50) with values of 59.6%, 74.7%, and 100% after 24, 48, and 72 h, respectively. The exposure of A. aegypti adults to the vapor of burning Ag-NPs-based coils caused a reduction of unfed individuals with a percentage of 81.6 ± 0.5% compared with the positive control, pyrethrin-based coils (86.1 ± 1.1%). The ovicidal activity of biosynthesized Ag-NPs caused the hatching of the eggs with percentages of 50.1 ± 0.9, 33.5 ± 1.1, 22.9 ± 1.1, and 13.7 ± 1.2% for concentrations of 5, 10, 15, and 20 ppm, whereas Ag-NPs at a concentration of 25 and 30 ppm caused complete egg mortality (100%). The obtained data confirmed the applicability of biosynthesized Ag-NPs to the biocontrol of A. aegypti at low concentrations.

Synthesis and characterization of new functionalized chitosan and its antimicrobial and in-vitro release behavior from topical gel

Recently, chitosan and its derivatives have been gaining more attention due to their high integration into various biomedical applications. Herein, a new chitosan derivative was prepared by linking the chitosan (Cs) with a novel heterocyclic compound, Benzoimidazolyl-thiadiazole (BzimTD) to form Cs-BzimTD. The synthesis of the new chitosan derivative was confirmed by Fourier-Transform Infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (¹H NMR), thermogravimetric (TGA-DTG) analysis, elemental analysis, and UV-Visible spectrophotometer. Data showed the high efficacy of functionalized Cs-BzimTD to inhibit the growth of pathogenic microbes, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans, with inhibition zones of 15.3 ± 0.6 - 9.2 ± 0.3 mm. Also, Cs-BzimTD was applied in a topical gel formulation by using two different polymers, Carbopol 940 (CP) and Carboxymethyl Cellulose (CMC) to form three gel formulations: Cs-BzimTD-CP, Cs-BzimTD-CMC, and Cs-BzimTD-CP-CMC. The new gels were checked for physical appearance, viscosity, Cs-BzimTD release, pH, spread-ability, and drug content. The results showed that all formulations were clear, transparent, and homogeneous with non-irritant pH values for skin (6.4 - 6.8). The spread-ability was found in the range of 7.1 - 9.4 g.cm/s. The Cs-BzimTD-CP formula showed the maximal Cs-BzimTD content percentage (86.5%) and the Cs-BzimTD release varied from 89.9 to 81.6% after 8 h depending on the gel formulation, with a maximum release achieved for Cs-BzimTD-CMC.

Enhanced Antimicrobial, Cytotoxicity, Larvicidal, and Repellence Activities of Brown Algae, Cystoseira crinita-Mediated Green Synthesis of Magnesium Oxide Nanoparticles

Herein, the metabolites secreted by brown algae, Cystoseira crinita, were used as biocatalyst for green synthesis of magnesium oxide nanoparticles (MgO-NPs). The fabricated MgO-NPs were characterized using UV-vis spectroscopy, Fourier transforms infrared spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy linked with energy-dispersive X-ray (SEM-EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Data showed successful formation of crystallographic and spherical MgO-NPs with sizes of 3–18 nm at a maximum surface plasmon resonance of 320 nm. Moreover, EDX analysis confirms the presence of Mg and O in the sample with weight percentages of 54.1% and 20.6%, respectively. Phyco-fabricated MgO-NPs showed promising activities against Gram-positive bacteria, Gram-negative bacteria, and Candida albicans with MIC values ranging between 12.5 and 50 μg mL⁻¹. The IC₅₀ value of MgO-NPs against cancer cell lines (Caco-2) was 113.4 μg mL⁻¹, whereas it was 141.2 μg mL⁻¹ for normal cell lines (Vero cell). Interestingly, the green synthesized MgO-NPs exhibited significant larvicidal and pupicidal activity against Musca domestica. At 10 μg mL⁻¹ MgO-NPs, the highest mortality percentages were 99.0%, 95.0%, 92.2%, and 81.0% for I, II, III instars’ larvae, and pupa of M. domestica, respectively, with LC₅₀ values (3.08, 3.49, and 4.46 μg mL⁻¹), and LC₉₀ values (7.46, 8.89, and 10.43 μg mL⁻¹), respectively. Also, MgO-NPs showed repellence activity for adults of M. domestica at 10 μg mL⁻¹ with 63.0%, 77.9%, 84.9%, and 96.8% after 12, 24, 48, and 72 h, respectively.

Green Synthesis of Zinc Oxide Nanoparticles (ZnO-NPs) by Pseudomonas aeruginosa and Their Activity against Pathogenic Microbes and Common House Mosquito, Culex pipiens

The synthesis of nanoparticles by green approaches is gaining unique importance due to its low cost, biocompatibility, high productivity, and purity, and being environmentally friendly. Herein, biomass filtrate of Pseudomonas aeruginosa isolated from mangrove rhizosphere sediment was used for the biosynthesis of zinc oxide nanoparticles (ZnO-NPs). The bacterial isolate was identified based on morphological, physiological, and 16S rRNA. The bio-fabricated ZnO-NPs were characterized using color change, UV-visible spectroscopy, FT-IR, TEM, and XRD analyses. In the current study, spherical and crystalline nature ZnO-NPs were successfully formed at a maximum SPR (surface plasmon resonance) of 380 nm. The bioactivities of fabricated ZnO-NPs including antibacterial, anti-candida, and larvicidal efficacy were investigated. Data analysis showed that these bioactivities were concentration-dependent. The green-synthesized ZnO-NPs exhibited high efficacy against pathogenic Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), and unicellular fungi (Candida albicans) with inhibition zones of (12.33 ± 0.9 and 29.3 ± 0.3 mm), (19.3 ± 0.3 and 11.7 ± 0.3 mm), and (22.3 ± 0.3 mm), respectively, at 200 ppm. The MIC value was detected as 50 ppm for E. coli, B. subtilis, and C. albicans, and 200 ppm for S. aureus and P. aeruginosa with zones of inhibition ranging between 11.7 ± 0.3-14.6 ± 0.6 mm. Moreover, the biosynthesized ZnO-NPs showed high mortality for Culex pipiens with percentages of 100 ± 0.0% at 200 ppm after 24 h as compared with zinc acetate (44.3 ± 3.3%) at the same concentration and the same time.

The influence of gamma radiation on organic compounds having carbon ring and its application in dosimetry

The formation of highly oxidizing radicals in multifunctional-solid compounds upon irradiation with gamma-ray had been investigated. Five organic compounds having a single carbon ring had been used in the present investigation; these materials are 1-chloro-4-nitrobenzene, 4′-aminoacetophenone, 3′-hydroxyacetophenone, n-anthranilic acid, and triphenylmethane. These material were irradiated using 60Co radiation with different doses between 20 and 100 kGy. Electron spin resonance spectroscopy spotted increases of the resonance absorption having landé factor around 2.0113 ± 0.003 upon irradiation with the increasing of dose. This resonance absorption was related to the formation of long-lived oxygen radicals that were attached to one of the radiation synthesized compounds. The method of infrared absorption spectroscopy emphasized the formation of cyclic and aliphatic hexane in addition to the active oxygen radicals. n-Anthranilic acid was found to be suitable for radiation the dosimetry with long-lasting radiation signature as electron spin and also to determine the exposure dose. The time-lapse infrared and electron spin resonance measurements had been used to tracked the formation of active species within the time-lapsed after the end of exposure; results showed that the dosimetric signature may be used as a tracker for the time when the exposure happens.

An Eco-Friendly Approach to the Control of Pathogenic Microbes and Anopheles stephensi Malarial Vector Using Magnesium Oxide Nanoparticles (Mg-NPs) Fabricated by Penicillium chrysogenum

The discovery of eco-friendly, rapid, and cost-effective compounds to control diseases caused by microbes and insects are the main challenges. Herein, the magnesium oxide nanoparticles (MgO-NPs) are successfully fabricated by harnessing the metabolites secreted by Penicillium chrysogenum. The fabricated MgO-NPs were characterized using UV-Vis, XRD, TEM, DLS, EDX, FT-IR, and XPS analyses. Data showed the successful formation of crystallographic, spherical, well-dispersed MgO-NPs with sizes of 7-40 nm at a maximum wavelength of 250 nm. The EDX analysis confirms the presence of Mg and O ions as the main components with weight percentages of 13.62% and 7.76%, respectively. The activity of MgO-NPs as an antimicrobial agent was investigated against pathogens Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans, and exhibited zone of inhibitions of 12.0 ± 0.0, 12.7 ± 0.9, 23.3 ± 0.8, 17.7 ± 1.6, and 14.7 ± 0.6 mm respectively, at 200 µg mL-1. The activity is decreased by decreasing the MgO-NPs concentration. The biogenic MgO-NPs exhibit high efficacy against different larvae instar and pupa of Anopheles stephensi, with LC50 values of 12.5-15.5 ppm for I-IV larvae instar and 16.5 ppm for the pupa. Additionally, 5 mg/cm2 of MgO-NPs showed the highest protection percentages against adults of Anopheles stephensi, with values of 100% for 150 min and 67.6% ± 1.4% for 210 min.

Rhizopus oryzae-Mediated Green Synthesis of Magnesium Oxide Nanoparticles (MgO-NPs): A Promising Tool for Antimicrobial, Mosquitocidal Action, and Tanning Effluent Treatment

The metabolites of the fungal strain Rhizopus oryaze were used as a biocatalyst for the green-synthesis of magnesium oxide nanoparticles (MgO-NPs). The production methodology was optimized to attain the maximum productivity as follows: 4 mM of precursor, at pH 8, incubation temperature of 35 °C, and reaction time of 36 h between metabolites and precursor. The as-formed MgO-NPs were characterized by UV-Vis spectroscopy, TEM, SEM-EDX, XRD, DLS, FT-IR, and XPS analyses. These analytical techniques proved to gain crystalline, homogenous, and well-dispersed spherical MgO-NPs with an average size of 20.38 ± 9.9 nm. The potentiality of MgO-NPs was dose- and time-dependent. The biogenic MgO-NPs was found to be a promising antimicrobial agent against the pathogens including Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans with inhibition zones of 10.6 ± 0.4, 11.5 ± 0.5, 13.7 ± 0.5, 14.3 ± 0.7, and 14.7 ± 0.6 mm, respectively, at 200 μg mL-1. Moreover, MgO-NPs manifested larvicidal and adult repellence activity against Culex pipiens at very low concentrations. The highest decolorization percentages of tanning effluents were 95.6 ± 1.6% at 100 µg/ 100 mL after 180 min. At this condition, the physicochemical parameters of tannery effluents, including TSS, TDS, BOD, COD, and conductivity were reduced with percentages of 97.9%, 98.2%, 87.8%, 95.9%, and 97.3%, respectively. Moreover, the chromium ion was adsorbed with percentages of 98.2% at optimum experimental conditions.

Harnessing Bacterial Endophytes for Promotion of Plant Growth and Biotechnological Applications: An Overview

Endophytic bacteria colonize plants and live inside them for part of or throughout their life without causing any harm or disease to their hosts. The symbiotic relationship improves the physiology, fitness, and metabolite profile of the plants, while the plants provide food and shelter for the bacteria. The bacteria-induced alterations of the plants offer many possibilities for biotechnological, medicinal, and agricultural applications. The endophytes promote plant growth and fitness through the production of phytohormones or biofertilizers, or by alleviating abiotic and biotic stress tolerance. Strengthening of the plant immune system and suppression of disease are associated with the production of novel antibiotics, secondary metabolites, siderophores, and fertilizers such as nitrogenous or other industrially interesting chemical compounds. Endophytic bacteria can be used for phytoremediation of environmental pollutants or the control of fungal diseases by the production of lytic enzymes such as chitinases and cellulases, and their huge host range allows a broad spectrum of applications to agriculturally and pharmaceutically interesting plant species. More recently, endophytic bacteria have also been used to produce nanoparticles for medical and industrial applications. This review highlights the biotechnological possibilities for bacterial endophyte applications and proposes future goals for their application.

Comparative Study between Exogenously Applied Plant Growth Hormones versus Metabolites of Microbial Endophytes as Plant Growth-Promoting for Phaseolus vulgaris L

Microbial endophytes organize symbiotic relationships with the host plant, and their excretions contain diverse plant beneficial matter such as phytohormones and bioactive compounds. In the present investigation, six bacterial and four fungal strains were isolated from the common bean (Phaseolus vulgaris L.) root plant, identified using molecular techniques, and their growth-promoting properties were reviewed. All microbial isolates showed varying activities to produce indole-3-acetic acid (IAA) and different hydrolytic enzymes such as amylase, cellulase, protease, pectinase, and xylanase. Six bacterial endophytic isolates displayed phosphate-solubilizing capacity and ammonia production. We conducted a field experiment to evaluate the promotion activity of the metabolites of the most potent endophytic bacterial (Bacillus thuringiensis PB2 and Brevibacillus agri PB5) and fungal (Alternaria sorghi PF2 and, Penicillium commune PF3) strains in comparison to two exogenously applied hormone, IAA, and benzyl adenine (BA), on the growth and biochemical characteristics of the P. vulgaris L. Interestingly, our investigations showed that bacterial and fungal endophytic metabolites surpassed the exogenously applied hormones in increasing the plant biomass, photosynthetic pigments, carbohydrate and protein contents, antioxidant enzyme activity, endogenous hormones and yield traits. Our findings illustrate that the endophyte Brevibacillus agri (PB5) provides high potential as a stimulator for the growth and productivity of common bean plants.

Multifunctional Aspects of the Synthesized Pyrazoline Derivatives for AP1 5L X60 Steel Protection Against MIC and Acidization: Electrochemical, In Silico, and SRB Insights

The inhibitory impact of low-cost synthesized pyrazoline derivatives named Pz series (Pz1 and Pz2) on the corrosion of API 5L X60 carbon steel in 5 M HCl was inspected to serve as corrosion inhibitors against such a solution for its usage in the oilfield well acidization process. Also, the same compounds were unitized as biocides for sulfate-reducing bacteria (SRBs) to inhibit the microbial-induced corrosion effect. This study was conducted via several electrochemical techniques, namely, electrochemical potentiodynamic polarization (EP) and electrochemical impedance spectroscopy (EIS), in addition to computational density functional theory (DFT). The inhibition efficiency (IE) of Pz series on the corrosion of 5L X60 carbon steel in 5 M HCl was found to increase whenever the Pz series molecule concentration was increased. EP measurements revealed that Pz1 and Pz2 have both cathodic and anodic features (mixed inhibitor) and their corrosion IEs were around 90%. The physicochemical properties of the Pz1 and Pz2 compounds were studied using Langmuir adsorption isotherms, where the equilibrium adsorption data were found to follow it accurately. EIS outputs were found to comply with the values obtained from EP. Scanning electron microscopy was used to examine the topographic anisotropy between the inhibited and uninhibited 5L X60 carbon steel samples to double-check the electrochemical findings. DFT calculations and Monte Carlo simulations were utilized to predict the behavior of inhibitors and to rationalize the experimental results. The serial dilution bioassay technique was used to assess the Pz series as potential biocides to counter the effect of SRBs in compliance with the TM0194-2014-SG standard test method, and the results showed the potency of Pz series in inhibiting such bacterial growth.

Plant Growth-Promoting Endophytic Bacterial Community Inhabiting the Leaves of Pulicaria incisa (Lam.) DC Inherent to Arid Regions

In this study, 15 bacterial endophytes linked with the leaves of the native medicinal plant Pulicaria incisa were isolated and identified as Agrobacterium fabrum, Acinetobacter radioresistant, Brevibacillus brevis, Bacillus cereus, Bacillus subtilis, Paenibacillus barengoltzii, and Burkholderia cepacia. These isolates exhibited variant tolerances to salt stress and showed high efficacy in indole-3-acetic acid (IAA) production in the absence/presence of tryptophan. The maximum productivity of IAA was recorded for B. cereus BI-8 and B. subtilis BI-10 with values of 117 ± 6 and 108 ± 4.6 μg mL-1, respectively, in the presence of 5 mg mL-1 tryptophan after 10 days. These two isolates had a high potential in phosphate solubilization and ammonia production, and they showed enzymatic activities for amylase, protease, xylanase, cellulase, chitinase, and catalase. In vitro antagonistic investigation showed their high efficacy against the three phytopathogens Fusarium oxysporum, Alternaria alternata, and Pythium ultimum, with inhibition percentages ranging from 20% ± 0.2% to 52.6% ± 0.2% (p ≤ 0.05). Therefore, these two endophytic bacteria were used as bio-inoculants for maize seeds, and the results showed that bacterial inoculations significantly increased the root length as well as the fresh and dry weights of the roots compared to the control plants. The Zea mays plant inoculated with the two endophytic strains BI-8 and BI-10 significantly improved (p ≤ 0.05) the growth performance as well as the nutrient uptake compared with an un-inoculated plant.

Endophytic Streptomyces laurentii Mediated Green Synthesis of Ag-NPs with Antibacterial and Anticancer Properties for Developing Functional Textile Fabric Properties

Improvement of the medical textile industry has received more attention recently, especially with widespread of microbial and viral infections. Medical textiles with new properties, such as bacterial pathogens self-cleaning, have been explored with nanotechnology. In this study, an endophytic actinomycetes strain of Streptomyces laurentii R-1 was isolated from the roots of the medicinal plant Achillea fragrantissima. This is used as a catalyst for the mediated biosynthesis of silver nanoparticles (Ag-NPs) for applications in the textile industry. The biosynthesized Ag-NPs were characterized using UV-vis spectroscopy, Fourier transform infrared (FT-IR), transmission electron microscopy (TEM), and X-ray Diffraction (XRD), which confirmed the successful formation of crystalline, spherical metal nanoparticles. The biosynthesized Ag-NPs exhibited broad-spectrum antibacterial activity. Our data elucidated that the biosynthesized Ag-NPs had a highly cytotoxic effect against the cancerous caco-2 cell line. The selected safe dose of Ag-NPs for loading on cotton fabrics was 100 ppm, regarding their antibacterial activity and safe cytotoxic efficacy. Interestingly, scanning electron microscope connected with energy dispersive X-ray spectroscopy (SEM-EDX) of loaded cotton fabrics demonstrated the smooth distribution of Ag-NPs on treated fabrics. The obtained results highlighted the broad-spectrum activity of nano-finished fabrics against pathogenic bacteria, even after 5 and 10 washing cycles. This study contributes a suitable guide for the performance of green synthesized NPs for utilization in different biotechnological sectors.

Novel Technique of Pneumatic Posterior Capsulorhexis for Treatment and Prevention of Posterior Capsular Opacification

PURPOSE

To evaluate a new technique of posterior capsulorhexis using air support to treat primary posterior capsular opacification (PCO) during cataract extraction surgery or to prevent postoperative PCO.

SETTING

(1) Ophthalmology department, Faculty of Medicine, Minia University, 61519, El-Minia, Egypt. (2) Security Forces Hospital, Ophthalmology Department, Riyadh, Kingdom of Saudi Arabia.

DESIGN

Prospective, randomized, consecutive case comparative non controlled study.

METHODS

One hundred eyes of 100 patients with a mean age of 63.3 years with dense cataract were enrolled in the study. Fifty of them (group (1)) were with primary PCO (discovered during the operations) and fifty (group (2)) with clear posterior capsule. All of the patients underwent phacoemulsification and posterior capsulorhexis using the air to support the posterior capsule. Then, IOL implantations were done between the anterior and posterior capsular rims. Postoperatively, each patient was evaluated for the following: visual acuity (UCVA and BCVA), manifest refractive spherical equivalent (MRSE), intraocular pressure, intraocular lens (IOL) stability, visual axis opacification, and posterior segment complications as retinal breaks, retinal detachment, or cystoid macular edema (CME).

RESULTS

There were no significant differences in UCVA, BCVA, and MRSE. All cases had a clear visual axis, with stable IOL and normal IOP during the follow-up period without posterior segment complications. The VA improved significantly throughout the follow-up periods in both groups without significant clinical difference.

CONCLUSION

Pneumatic posterior capsulorhexis is a new effective technique for the treatment of primary PCO in dense cataract and for prevention of postoperative PCO with the good visual outcomes and minimal complications. This trial is registered with NCT04007965.

Macrophage recruitment and activation: a model for comparing resistance to Salmonella enteritidis in different broiler breeds

A model for comparing resistance to Salmonella Enteritidis was evaluated in different broiler breeds. The recruitment and phagocytic activity of peritoneal macrophages were assessed in three different broiler breeds (A, B and C) which are farmed world-wide. Assessment was performed after three days of intraperitoneal (i.p.) administration of 3% Sephadex G-200 (10 ml), initiated at twenty-one days of age, followed by contact with i.p. live S. Enteritidis (10 ml, 1.2 x 10(8) colony forming units/ml) for 45 min. Assessment included determination of the number of i.p. macrophages recruited, the number of i.p. phagocytized S. Enteritidis cells per macrophage, the levels of degranulated i.p. beta-glucuronidase and beta-galactosidase, and the count of surviving S. Enteritidis cells. Confirmation of the significance of the model was obtained by comparing resistance to field infection by S. Enteritidis in the three broiler breeds. The recruitment of i.p. macrophages in response to challenge with Sephadex and S. Enteritidis was significantly higher (P < 0.05) in birds of breed A (mean cumulative i.p. macrophage count, in 10 fields of microscopic slide smear magnified at x1,000, was equal to 81.7), compared to recruitment in birds of breed B (33.3) or breed C (41.2). The mean number of phagocytized S. Enteritidis cells per i.p. macrophage in birds of breed A (2.68) was significantly higher (P < 0.05) than in breed B (0.83) and insignificantly higher (P > 0.05) than in breed C (2.35). In addition, the highest level of recruitment and phagocytic activity of macrophages, in birds of breed A, was associated with a higher significant mean i.p. beta-glucuronidase activity (10,425.5 units/ml) than in breed B (3,438.2 units/ml) or breed C (3,356.94 units/ml) (P < 0.05). Moreover, birds of breed A demonstrated a higher mean i.p. beta-galactosidase activity (2.225 units/ml) than birds of breed B (0.852 units/ml) or breed C (1.852 units/ml) (P > 0.05). The higher level of recruitment and activity of i.p. macrophages and the higher rate of degranulation of i.p. enzymes in breed A were associated with a greater number of surviving i.p. S. Enteritidis cells. In response to outbreaks of S. Enteritidis in the field, the average mortality was significantly higher in flocks of breed A (3.2%) than in flocks of breed B (1.2%) or breed C (0.96%) (P < 0.05). These data provide an indication of the significance of the model in reflecting the differences in resistance of S. Enteritidis of broiler breeds reared in a farm environment.

Acute haematogenous osteomyelitis and ABO blood groups and secretor status

A correlation was found between the incidence of acute haematogenous osteomyelitis (AHO) and ABO blood groups but not between AHO and the secretory function of the saliva. AHO is more common among children of blood group O and, to a lesser extent, group A. Although it was found to occur more commonly among secretors than non-secretors, the difference from a control group was not statistically significant. At present this possibility can only be taken as a tentative suggestion for further research in this field.

Fractures of the pelvis

Pelvic fractures in this series constituted 3.3% of all traumatic admissions and 5.7% of all fractures. A classification of pelvic fractures was adopted in which five types were identified. Type I (24.2%) comprised fractures without a break in the pelvic ring. Type II (17.7%) comprised those with a single break in the pelvic ring. Fractures with a double break of the pelvic ring constituted Type III (23.6%). Multiple fractures of the pelvis were identified as Type IV (10.8%). Fractures of the acetabulum were grouped separately as Type V (23.7%). On the basis of blood loss, mortality and potential disability, Types I and II constituted the 'minor' fractures of the pelvis. Types III, IV and V were the 'major' fractures of the pelvis, of which Type IV were the worst. The commonest fracture encountered was that of a single pubic ramus. The pubic area was involved in 43.0% of the cases. Associated injuries were common (2.19 per patient). Some of these lesions were the result of the causative trauma. Some others, however, were related to certain types of pelvic fractures.

Early urinary complications of fractures of the pelvis

The occurrence, relation to a particular type of fracture of the pelvis and the possible mechanism of early urinary complications were studied in 186 consecutive patients with fracture of the pelvis. Eighty-eight patients (47.3%) showed early urinary complications. These complications were minor in 73 patients (83.0%; 32.9% of all pelvic features) and major in 15 (17.0%; 8.1% of all pelvic fractures). The former comprised retention of urine in 41 patients (33.0%; 15.6% of all pelvic fractures), haematuria in 29 patients (33.0%; 15.6% of all pelvic fractures), and oliguria in three (3.4%; 1.6% of all pelvic fractures). The latter comprised rupture of the posterior urethra in nine patients (10.2%; 4.8% of all pelvic fractures), rupture of the bladder in five (5.7%; 2.7; of all pelvic fractures), and combined injury to the bladder and posterior urethra in one (1.1%; 0.5% of all pelvic fractures). These complications were common in relation to run-over and collision accidents. The common pelvic fracture encountered in these patients was the Type III and the individual pelvic fracture was that of both pubic rami on one or both sides; fractures of the acetabulum and posterior segment of the pelvis were next in frequency. On the other hand, fractures of a single ischial ramus or wing of the ilium were not commonly encountered. Fractures with intact pelvic ring were associated with only 9.1% of these complications; all were minor.

Aetiological factors in non-union following Küntscher intramedullary nailing of the femur

One hundred and three consecutive patients who underwent Küntscher intramedullary nailing for recent non-pathological single fracture of the femoral shaft showed 13.6% incidence of non-union. The latter complication was not significantly influenced by the type, site, and cause of the fracture nor by sex, timing of the operation, and reaming of the medullary cavity. Conversely, non-union was more common in older patients and in those who were in bad general condition prior to and at the time of operation. Similarly, non-union increased significantly when the nail was too thin, or its lower end did not reach the optimum level (2 cm higher than the joint line), when weight-bearing was started 6 weeks or less after operation and in the presence of post-operative knee stiffness. Two patients presented with broken nails and four with angulated nails in the presence of non-union. Three patients with segmental fracture of the femur showed non-union of the fracture nearer to the middle of the shaft.

Some immunological aspects of staphylococcal haematogenous osteomyelitis

Patients with primary (haematogenous) staphylococcal osteomyelitis have been suspected for being deficient in their immune response. Serum levels of the three major circulating immunoglobulins (IgG, IgA, and IgM) have been determined in 90 patients with this disease of varying duration and activity and in 100 control subjects. Of 270 measurements in the patient group, 80% fell within or below the normal (control) range. A small group of eight patients, however, were found to have sufficiently large increases in IgM levels to raise the mean value of the whole series to a statistically significnat level. Similarly IgA production was increased in chronic infection. These findings, on the whole, indicate that a majority of patients suffering from primary osteomyelitis may have depression of their normal immune response to infection.

Aetiological factors in infection following open retrograde intramedullary nailing of the femur

Thirty-three patients with chronic osteomyelitis of the femur following open retrograde Küntscher intramedullary nailing of the femur were studied to determine possible reasons for the development of infection. In 32 patients the indication for the operation was a closed fracture of the shaft of the femur (recent or malunited) and in one it was to shorten the femur. In 6 patients (18·2%) there was evidence of skin, urinary and upper respiratory tract infection. In 14 patients (42·4%) it was felt that potential infection was present in poor skin overlying the fracture and unhealed laparotomy wounds. Four patients were under the age of 15 years. The operating theatres lacked facilities for room-air exchange, for provision of filtered air or for modern body-exhaust systems. Twenty-two (66·7%) operations were performed by surgeons under training.

Osteomalacia as a contributing factor in fracture of the femoral neck in the elderly in Quatar

Eighty-seven patients with femoral neck fractures were investigated for possible evidence of osteomalacia. Eighteen patients were under the age of 50, or had sustained the fracture following severe injury. No evidence of osteomalacia was demonstrated in this group. In the remaining 69 patients the fracture was associated with a trivial injury, and in some patients no history of injury could be obtained. Only 16 (23.2%) of these showed evidence of osteomalacia; in 7 (10.1%) the disease was suspected. This occurred more often in women than men, and in trochanteric rather than cervical fractures.

Reduction of displaced supracondylar fracture of the humerus in children by manipulation in flexion

Sixty-one children with posteriourly displaced supracondylar fractures of the humerus were treated by minipulation with the elbow flexed 40 degrees-60 degrees. This method proved to be safe, easy to apply and was followed by a high rate of success. The elbow was immobilized using a collar-and-cuff or a broad sling and binding of the arm to the forearm with zinc oxide adhesive plaster. In difficult children, the limb was put under the child's clothing to avoid its being used. Redisplacement occurred in only 8.2 per cent of the patients and in none of these was it severe enough to justify remanipulation.

Treatment of chronic haematogenous osteomyelitis of the os calcis

Twenty-five patients suffering from chronic haematogenous osteomyelitis of the os calcis were studied. The disease often presents in a subacute or chronic form, and the pathological process is well established in the majority of the cases by the time treatment is begun. For this reason, conservative treatment was found to be ineffective. Similarly, limited surgical procedures, such as curettage, sequestrectomy or partial excision, were also inadequate because of the wide-spread nature of the infection. Complete excision of the os calcis and stitching of the Achilles tendon to the plantar fascia was followed by a high rate of success, provided the other tarsal bones were not involved in the infective process. The infection was cured and reasonably normal function was obtained in 14 out of 19 patients (73.7 per cent). A "new heel" is often formed after the operation by the laying down of plaques of calcification within the toughened scar tissue of the heel pad.