Publications by authors named "Medhat Ibrahim"

One of the biggest challenges in food packaging is the creation of sustainable and eco-friendly packaging materials to shield foods from ultraviolet (UV) photochemical damage and to preserve the distinctive physical, chemical, and biological characteristics of foods throughout the supply chain. Accordingly, this study focuses on enhancing the UV shielding properties and biological activity of carboxylmethyl cellulose sodium (CMC) through modifications using zinc oxide (ZnO), copper oxide (CuO), and graphene oxide (GO) using the solution casting technique. The hybrid nanocomposites were characterized by fourier-transform infrared (FTIR) spectrophotometer, ultraviolet-visible (UV-Vis) spectrophotometer, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and x-ray diffraction (XRD).

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Functionalization of cellulose with nanomaterials and functional groups is essential for enhancing its properties for specific applications, such as flexible sensors and printed electronics. This study employs Hartree Fock (HF) and Density Functional Theory (DFT) calculations to investigate the vibrational spectra of cellulose, identifying DFT: B3LYP/3-21 g** as the optimal model aligning with experimental spectra. Using this model, we examined the impact of functionalizing cellulose with various groups (OH, NH, COOH, CH, CHO, CN, SH) and graphene oxide (GO) on its electronic properties.

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Metals have a tendency to accumulate in the environment and can have carcinogenic effects. Accordingly, this study used density functional theory (DFT) calculations to investigate the adsorption of different metal ions on the glycine surface. Glycine has attracted a lot of research interest because of its remarkable metal-binding properties and cost effectiveness.

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Due to its appealing qualities, such as its miniature size and the ability to modify physical properties through chemical synthesis and molecular design, polymer material offers considerable advantages over traditional inorganic material-based electronics. Conjugate polymers are particularly interesting because of their molecular design capabilities, which enable the synthesis of conducting polymers with a variety of ionization potentials and electron affinities (EA), and their ability to control the energy gap and electronegativity (χ). Accordingly, density functional theory (DFT) at the B3LYP/SDD model was used to present possible interactions between polyaniline (PANi) and both alkali and heavy metal oxides.

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Because of the abundance of sodium resources, sodium-ion batteries (NIBs) offer a promising alternative electrochemical energy storage solution. One of the current roadblocks to the development of NIBs technology is a lack of electrode materials capable of reversibly storing/releasing sodium ions for a sufficiently long time. Thus, this work aims to study, theoretically, the effect of glycerin incorporation on polyvinyl alcohol (PVA)/sodium alginate (Na Alg) blend as electrode materials for NIBs.

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Article Synopsis
  • - Aplastic anemia (AA) and hypoplastic myelodysplastic syndrome (MDS) are similar bone marrow failure diseases, making diagnosis challenging; this study explored using flow cytometry for differentiation.
  • - Researchers analyzed bone marrow and blood samples from 44 participants: 17 with AA, 13 with hypoplastic MDS, and 14 healthy controls, focusing on CD34 levels and cell apoptosis.
  • - Findings revealed that hypoplastic MDS patients had more CD34+ cells with lower apoptosis, while AA patients had fewer CD34+ cells but higher apoptosis, suggesting distinct biological differences that could aid in accurate diagnosis.
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Modern laboratory medicine relies on analytical instruments for bacterial detection, focusing on biosensors and optical sensors for early disease diagnosis and treatment. Thus, Density Functional Theory (DFT) was utilized to study the reactivity of glycine interacted with metal oxides (ZnO, MgO, and CaO) for bacterial detection. Total dipole moment (TDM), frontier molecular orbitals (FMOs), FTIR spectroscopic data, electronic transition states, chemical reactivity descriptors, nonlinear optical (NLO) characteristics, and molecular electrostatic potential (MESP) were all investigated at the B3LYP/6-31G(d, p) level using DFT and Time-Dependent DFT (TD-DFT).

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Polylactic acid modified with graphene oxide (PLA/GO) is proposed to interact with ZnO through 6 different schemes. Density functional theory at B3LYP/LANL2DZ level was utilized to calculate total dipole moment (TDM), HOMO/LUMO energy gap (ΔE) and to map the molecular electrostatic potential (MESP). Results indicated that PLA/GO interacted with ZnO through O-atom forming PLA/GO/OZn composite.

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Atrazine is a widely used toxic herbicide that poses a threat to both the environment and human health. This study investigates the removal of Atrazine from water through armchair-hexagonal hexagonal graphene quantum dots (AHEX) simulations. The investigations are performed using density functional theory at the exchange-correlation hybrid functional B3LYP/3-21G level of theory.

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This study systematically investigated four types of graphene quantum dots (GQDs) AHEX, ZTRI, ZHEX, and ATRI, and their interactions with glycine to form GQD-glycine complexes. Utilizing density functional theory (DFT) and the PM6 semiempirical method, the study analyzed electronic properties and structure-activity relationships. Global reactivity indices were calculated using Koopmans' theorem, and quantitative structure-activity relationship (QSAR) parameters were assessed via SCIGRESS 0.

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In this work, molecular descriptors of N-(1-(2-bromobenzoyl)-4-cyano-1H-pyrazol-5-yl) halogenated benzamides (1a-h) have been computed using a quantum chemical technique through DFT. Prior work involved the synthesis of compounds (1a-h) and the assessment of their anticancer activity on breast, colon, and liver tumors: MCF-7, HCT-116, and HepG-2 cell lines respectively. Since 1a, 1b, and 1d showed the most potential anticancer impact, their ability to inhibit EGFR was investigated.

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The aquatic plant water hyacinth was dried then cross-linked with sodium alginate to produce ionic cross-linked microspheres. The mechanism of controlling cadmium (Cd) and lead (Pb) in wastewater was tested by DFT at B3LYP level using LANL2DZ basis set. Modeling results indicated that the hydrated metals could interact with sodium alginate (SA)/water hyacinth (WH) microspheres through hydrogen bonding.

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This study examined the functionalization of graphene with easily ionizable elements, such as lithium, and subsequently its interaction with the biopolymer sodium alginate (SA), to highlight its potential for biomedical applications. Utilizing Density Functional Theory (DFT), the research comprehensively investigated the structural, electronic, and spectroscopic properties of these graphene-based composites. The electronic properties of functionalized graphene were investigated using DFT at the B3LYP/6-31G(d,p) level.

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This groundbreaking research delves into the intricate molecular interactions between MXene and trihalomethanes (THs) through a comprehensive theoretical study employing density-functional theory (DFT). Trihalomethanes are common carcinogenic chlorination byproducts found in water sanitation systems. This study focuses on a pristine MXene [M·X] monolayer and its various terminal [T] functional groups [M·XT], strategically placed on the surface for enhanced performance.

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A 3-unit cellulose model molecule was built and optimized using DFT B3LYP/6-31G(d,p). The electronic properties of the optimized structure of cellulose were investigated in terms of total dipole moment (TDM), HOMO-LUMO band gap (ΔE), and molecular electrostatic potential (MESP). Cellulose demonstrated a TDM of 9.

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Nanoparticles have substantially contributed to the field of skincare products with ultraviolet (UV) filters to preserve human skin from sun damage. Thus, the current study aims to develop new polymer nanocomposites for the efficient block of UV light that results from the stratospheric ozone layer loss. Co-precipitation method was used to successfully synthesis CuO@ZnO core/shell NPs with a well-crystalline monoclinic CuO core and wurzite ZnO shell.

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Carbon doped ZnO nanoparticles have been synthesized from the thermal decomposition of Zinc citrate precursor. The precursor was synthesized from semi-solid paste and then subjected to calcination at 700 °C to produce ZnO nanoparticles. The precursor and ZnO were characterized by Fourier Transform Infrared Spectroscopy, UV-visible (UV-Vis) spectra, Transmission Electron Microscope, Field Emission Scanning Electron Microscope, Energy Dispersive Analysis by X-ray (EDAX), X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS).

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Bioactive glass (BG) was prepared by sol-gel method following the composition 60-([Formula: see text]) SiO.34CaO.6PO, where x = 10 (FeO, CuO, ZnO or GeO).

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Polytetrafluoroethylene (PTFE) is one of the most significant fluoropolymers, and one of the most recent initiatives is to increase its performance by using metal oxides (MOs). Consequently, the surface modifications of PTFE with two metal oxides (MOs), SiO and ZnO, individually and as a mixture of the two MOs, were modeled using density functional theory (DFT). The B3LYPL/LANL2DZ model was used in the studies conducted to follow up the changes in electronic properties.

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Ternary silicate glass (69SiO-27CaO-4PO) was synthesized with the sol-gel route, and different percentages of germanium oxide GeO (6.25, 12.5, and 25%) and polyacrylic acid (PAA) were added.

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A synergistic interaction between reduced graphene oxide (rGO) and a biodegradable natural polymer, sodium alginate, was developed to create unique microspheres with protruding spiky features at the surface (spiky microspheres) that act as a super encapsulation and sustained release system for the highly effective antibiotic cefotaxime. Three forms of microspheres, namely alginate (Alg), alginate-cefotaxime (Alg-CTX), and alginate-cefotaxime-reduced graphene (Alg-CTX-rGO) composites, were prepared using calcium chloride as a cross-linking agent. The microspheres were characterized using field emission scanning electron microscopy (FESEM), Fourier-transform infrared (FT-IR) spectroscopy, and X-ray diffraction to investigate their pores, roughness, surface morphology, functional groups, phase formation, purity, and structural properties.

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Relative humidity (RH) is one of the most important factors that deserve intensive study because of its impact on many aspects of life. In this work humidity sensor based on carbon nitride / graphene quantum dots (g-C3N4/GQDs) nanocomposites have been developed. The structure, morphology and composition properties of the g-C3N4/GQDs were investigated and analyzed by XRD, HR-TEM, FTIR, UV-Vis, Raman, XPS and BET surface area.

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Nanoparticles have made a substantial contribution to the field of skincare products with UV filters in preserving human skin from sun damage. The current study aims to create new polymer nanocomposite filters for the efficient block of UV light that results from the stratospheric ozone layer loss. The casting approach was used to add various mass fractions of copper oxide nanoparticles (CuO-NPs) to a solution of carboxymethyl cellulose (CMC).

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There are many challenges faced the soft tissue adhesives in the medical application field. For example, there is a limited effective binding between the medical adhesive and different types of soft tissues. Chitosan (CS) and dopamine (DA) were used as structural units for synthesizing nanocomposites utilized as a wet tissue adhesive.

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Due to modern industrialization and population growth, access to clean water has become a global challenge. In this study, a metal-semiconductor heterojunction was constructed between Cu NPs and the CoNiFeO/SiO/TiO composite matrix for the photodegradation of potassium permanganate, hexavalent chromium Cr(VI) and -nitroaniline (pNA) under UV light. In addition, the electronic and adsorption properties after Cu loading were evaluated using density functional theory (DFT) calculations.

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