Abdel-Aleam Hefney Mohamed

Schiff base macromolecules have been successfully synthesized, utilizing a classical chemistry route and a dielectric barrier discharge (DBD) plasma technique. The synthesis of monomeric units has been accomplished through typical reactions of aldehyde and amine functional molecules. The condensation polymerization of the Schiff base molecules has been instigated chemically, using p-toluene sulfonyl chloride in refluxed ethanol. The molecular weight of the obtained polymers was discovered to be 524,664 and 1,503,228 for polymers 4a and 4b, respectively. Additionally, the polymerization reactions were prompted, employing a Dielectric Barrier Discharge (DBD) atmospheric pressure air plasma technique. The DBD plasma demonstrated a very powerful routine to produce high molecular weights macromolecules, which could be an ecofriendly strategy to acquire this class of materials. Moreover, the complexation of polymer 4b with various metal moieties, Ru (II), Co (II), Cu (II), and Ni (II), has been executed in order to have a comparative study of their antitumor activity against MCF-7, A-549, HCT-116, and HepG-2 cell lines. Furthermore, the density functional theory was exploited to optimize the polymers and their complexes, and their HOMO-LUMO and energy gap were calculated, which was utilized to examine the inter/intra molecular charge transfer. The molecular electrostatic potential map was similarly quantified to investigate the reactive sites that are present in the investigated molecules. The result for the docking study confirmed that these complexed polymers adopted numerous important interactions with the amino acid of the targeted enzyme.

Methylene blue dye, being toxic, carcinogenic and non-biodegradable, poses a serious threat for human health and environmental safety. The effective and time-saving removal of such industrial dye necessitates the use of innovative technologies such as silver nanoparticle-based catalysis. Utilizing a pulsed Nd:YAG laser operating at the second harmonic generation of 532 nm with 2.6 J energy per pulse and 10 ns pulse duration, Ag nanoparticles were synthesized via an eco-friendly method with sodium dodecyl sulphate (SDS) as a capping agent. Different exposure times (15, 30, and 45 min) resulted in varying nanoparticle sizes. Characterization was achieved through UV–Vis absorption spectroscopy, scanning electron microscopy (SEM) imaging, and energy dispersive X-ray (EDX). Lorentzian fitting was used to model nanoparticle size, aligning well with SEM results. Mie’s theory was applied to evaluate the absorption, scattering, and extinction cross-sectional area spectra. EDX revealed increasing Ag and carbon content with exposure time. The SDS-caped AgNPs nanoparticles were tested as catalyst for methylene blue degradation, achieving up to 92.5% removal in just 12 min with a rate constant of 0.2626 min⁻¹, suggesting efficient and time-saving catalyst compared to previously reported Ag-based nanocatalysts.

Background: The emergence of dental implants has revolutionized the management of tooth loss. However, the placement of clinical implants exposes them to complex oral environment and numerous microscopic entities, such as bacteria. Cold atmospheric plasma (CAP) is often used to treat the surfaces of dental implants, which alters morphological features and effectively reduces bacterial load. Purpose: This systematic review aims to assess the existing literature on the bactericidal properties of CAP when used on various kinds of dental implant surfaces. Review Method: An in-depth examination of MEDLINE/PubMed and EMBASE was performed to identify relevant studies, with the most recent search conducted in May 2023. Studies were selected based on their exploration of CAP’s effects on dental implants compared to control groups, focusing on CAP’s bactericidal efficacy. However, studies that lacked a control group or that failed to measure bactericidal effects were excluded. Results: After applying the selection criteria, 15 studies were ultimately included in the systematic review. The collected data suggest that CAP can effectively reduce bacterial loads on dental implant surfaces, including pathogens like Streptococcus mitis and Staphylococcus aureus. Furthermore, CAP appears to combat biofilms and plaques that are key contributors to periimplantitis. Conclusion: CAP emerges as a promising treatment option, exhibiting significant bactericidal activity on dental implant surfaces. CAP can decrease the rates of bacterial biofilm and plaque formation, leading to improved outcomes for dental implant patients.

PVP/CMC/ZnS–NiO blends were produced by casting, solgel and solid state reactions methods. Both ZnS and NiO have a nanonature with a crystallite size of 3 and 70 nm, respectively. The effect of laser irradiation with different energies (70–150) mJ/cm2 on the structural and morphology of the blends was investigated using x-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy techniques. The optical bandgap energy values decreased gradually from 4.5 eV (for unirradiated blend) to reach 4.1 eV (for blends irradiated with higher laser energy of 150 mJ/cm2) in the case of direct transition, while for indirect transition, values decrease from 3.4 to 3 eV. The effect of laser irradiation on the absorption, transmittance, extinction coefficient, refractive index, dielectric parameters, optical conductivity, and the nonlinear parameters of the blends was examined using UV spectrophotometer technique. The enhancements in both optical and structural properties play a necessary role as a strong support for the future use of polyvinyl pyrrolidone/carboxymethyl cellulose nanocomposite blends in the field of optoelectronic devices applications.

Nonthermal equilibrium atmospheric pressure plasma jet gained great interest due to its multidisciplinary applications. This work is focused on studying the characteristics of an argon atmospheric pressure plasma jet and the laminar‐to‐turbulent flow mode transition. By increasing the applied voltage from 10 to 25 kV, the plasma can run in four operational modes depending on the number of current pulses per half a cycle of the applied voltage. The plasma jet gas temperature increases from 310 to 370 K and the laminar‐to‐turbulent transition value shifts toward lower flow rate values from 3.75 to 2.6 slpm as a result of increasing the applied voltage. A clear border between the laminar and the turbulent regions has been resolved at different applied voltages and flow rates at a fixed applied frequency of 24 kHz.

Non-thermal atmospheric pressure plasmas are a powerful tool to impact seed germination and microbial decontamination. Air large volume atmospheric pressure glow discharge plasma was developed and investigated to improve the biological activities ofMoringa oleiferaseeds. Ninty ns magnetic pulse compression high voltage system was used to generate the plasma. The plasma discharges current increases with increasing applied voltage and it decreases with increasing discharge gap. There was a steady reduction in the count of seedborne fungi on the application of air cold plasma with complete elimination of fungi at ≥ 10.94 mJ per pulse. The low doses of plasma (2.46 and 4.35 mJ) induced an increase in the seed germination, a significant increase in chlorophyll content (chlaand chlb) and antioxidant activities of the seedlings emerged from soaked or wet seeds rather than dry seeds. At lower plasma doses (2.46 and 4.35 mJ) there was a significant increase in leaf area and chlorophyll content (chlaand chlb) of the seedlings that emerged from H₂O₂soaked seeds rather than that of free from H₂O₂. The plasma was harmful when applied at higher doses (≥ 10.94 mJ) and more harmful to the wet seeds compared to the dry ones.

Cold atmospheric pressure sterilization is one of the nominated and efficient techniques to prevent the spread of diseases. Reactive species such as O and OH and other radicals play a major role in the mechanism of plasma sterilization. Therefore, in this work, oxygen was mixed with different parentage from (0.2 to 1.2%) to argon to enhance the generation of the reactive species and increase the argon atmospheric pressure plasma sterilization efficacy. The emission spectra from the jet increase the radicle line intensities by increasing the percentage admixture of O₂ with the argon gas to reach a maximum power at 0.8; then, it gradually decreases with a higher O² percentage. The OH band intensity decreases with increasing the admixture of O₂. The jet with different O₂ percentages was tested against Gram-positive S. epidermidis, which is the causal agent of nosocomial infections. The maximum reduction in colony-forming units (CFU) was observed at 0.2% O₂. No bacterial growth was observed at the later concentration applied for 8 min and the same case was detected at 0.4% O₂ applied to 16 min.