Publications by authors named "Ayman Gouda"

The release of harmful organic dyes from different industries besides its degradation products is a major contributor to environmental contamination. The catalytic reduction of these organic pollutants using nanocomposites based on polymeric material presents potential advantages for the environment. In this study, novel nanocomposite based on cellulose acetate (CA)-derived from discharged cigarette butts and zinc oxide nanoparticles (ZnO NPs) was prepared utilizing a very simple and low-cost solution blending method and used as support for silver nanoparticles (Ag NPs).

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A new synthetic material, namely, (3-(((4-((5-(((S)-hydroxyhydrophosphoryl)oxy)-2-nitrobenzylidene) amino) phenyl) imino) methyl)-4-nitrophenyl hydrogen (R)-phosphonate)), was subjected to a quaternary ammonium salt and named (HNAP/QA). Several characterizations, such as FTIR spectrometry, H-NMR analysis, C-NMR analysis, P-NMR Analysis, TGA analysis, and GC-MS analysis, were performed to ensure its felicitous preparation. HNAP/QA is capable of the selective adsorption of W(VI) ions from its solutions and from its rock leachate.

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Purpose: Surgical removal of intra-bony calcific benign lesions is technically challenging regarding its accessibility, proximity to vital structures, and deteriorating effect on the remaining bony structures.

Methods: Computer-guided buccal cortical plate separation was performed for ten patients using patient-specific osteotomy locating guides and pre-bent plates. The guide was designed to outline the osteotomy, the buccal cortical plate was separated, the lesion was removed, and finally, the pre-bent plates were used to fix the separated cortex.

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Tannery industries are one of the extensive industrial activities which are the major source of chromium contamination in the environment. Chromium contamination has been an increasing threat to the environment and human health. Therefore, the removal of chromium ions is necessary to save human society.

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Spent Ni-Cd batteries are now considered an important source for many valuable metals. The recovery of cadmium, cobalt, and nickel from spent Ni-Cd Batteries has been performed in this study. The optimum leaching process was achieved using 20% HSO, solid/liquid (S/L) 1/5 at 80 °C for 6 h.

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Considering how important rare earth elements (REEs) are for many different industries, it is important to separate them from other elements. An extractant that binds to REEs inexpensively and selectively even in the presence of interfering ions can be used to develop a useful separation method. This work was designed to recover REEs from spent nickel-metal hydride batteries using ammonium sulfate.

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A low-cost, simple, and highly selective method was used for the assessment of total prostate specific antigen (tPSA) in the serum of prostate cancer patients. This method is based on quenching the intensity of luminescence displayed by the optical sensor Eu (TTA) phen/poly methylmethacrylate (PMMA) thin membrane or film upon adding different concentrations of tPSA. The luminescent optical sensor was synthesized and characterized through absorption, emission, scanning electron microscopy (SEM), and x-ray diffraction (XRD), and is tailored to present red luminescence at 614 nm upon excitation at 395 nm in water.

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We developed a novel, simple, sensitive, accurate, and precise method for the determination of calcitonin in different serum samples with medullar thyroid carcinoma. The designed flower-like thin film gold nanoparticles doped in a sol-gel/polyethylene glycol mold are used as an optical biosensor for the efficient determination of calcitonin. The sensor was characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray microanalysis, and Fourier-transform infrared spectroscopy.

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Purpose: The aim of this study was to evaluate available bone quality and quantity after performing sinus augmentation using simvastatin/β-TCP combination versus β-TCP alone.

Materials And Methods: This study included eight sinus lift procedures conducted on six patients. The sinuses were divided into two equal groups.

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Aim: This study was established to evaluate the amount of bone height changes in the posterior mandibular area of edentulous patients receiving screw-retained prostheses versus removable telescopic implant overdentures.

Material And Methods: Every patient received four inter-foraminal implants regarding the mandibular arch and four anterior implants for the maxillary arch, computer guided surgical guides were planned for the insertion of the implants accurately with a flapless technique. Panoramic radiographs were made immediately, six months and twelve months after the prostheses` use proportional area and vertical measurements were applied to determine changes in the bone height of the posterior mandibular edentulous area.

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A novel, simple and robust high-performance liquid chromatography (HPLC) method was developed and validated for simultaneous determination of xipamide (XIP), triamterene (TRI) and hydrochlorothiazide (HCT) in their bulk powders and dosage forms. Chromatographic separation was carried out in less than two minutes. The separation was performed on a RP C-18 stationary phase with an isocratic elution system consisting of 0.

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A new, sensitive and simple solid phase extraction (SPE), separation and preconcentration method of some heavy metal ions, Cd(II), Cu(II), Ni(II), Pb(II) and Zn(II) at trace levels using multiwalled carbon nanotubes (MWCNTs) impregnated with 2-(2-benzothiazolylazo)orcinol (BTAO) from food and water samples were investigated. The effect of analytical parameters was examined. The metals retained on the nanotubes at pH 7.

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A new simple and sensitive preconcentration, separation and environmentally friendly method based on carrier element free coprecipitation (CEFC) was developed using 4-(2-hydroxybenzylideneamino)-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one (APSAL) as a new organic co-precipitant to precipitate Cr(3+), Cu(2+), Fe(3+), Pb(2+) and Zn(2+) ions from water and food samples. The levels of the studied elements were detected by flame atomic absorption spectrometry (FAAS). The impact of several analytical parameters, such as pH, sample volume and coprecipitant amount as well as centrifugation rate and time was investigated to recover the examined metal ions.

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A new cloud point extraction (CPE) process using the nonionic surfactant Triton X-114 to extract manganese(II) from aqueous solution was investigated. The method is based on the complexation reaction of manganese(II) with 1,2,5,8-tetrahydroxyanthracene-9,10-dione (quinalizarin) in the presence of borate buffer at pH 8.5 and micelle-mediated extraction of the complex.

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Simple, rapid and accurate high performance liquid chromatographic (HPLC) and spectrophotometric methods are described for determination of antihistaminic acrivastine in capsules. The first method (method A) is based on accurate, sensitive and stability indicating chromatographic separation method. Chromolith® Performance RP-18e column, a relatively new packing material consisting of monolithic rods of highly porous silica, was used as stationary phase applying isocratic binary mobile phase of ACN and 25 mM NaH2PO4 pH 4.

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SIMPLE, RAPID, AND EXTRACTIVE SPECTROPHOTOMETRIC METHODS WERE DEVELOPED FOR THE DETERMINATION OF SOME FLUOROQUINOLONES ANTIBIOTICS: gemifloxacin mesylate (GMF), moxifloxacin hydrochloride (MXF), and enrofloxacin (ENF) in pure forms and pharmaceutical formulations. These methods are based on the formation of ion-pair complexes between the basic drugs and acid dyes, namely, bromocresol green (BCG), bromocresol purple (BCP), bromophenol blue (BPB), bromothymol blue (BTB), and methyl orange (MO) in acidic buffer solutions. The formed complexes were extracted with chloroform and measured at 420, 408, 416, 415, and 422 nm for BCG, BCP, BPB, BTB, and MO, respectively, for GMF; at 410, 415, 416, and 420 nm for BCP, BTB, BPB, and MO, respectively, for MXF; and at 419 and 414 nm for BCG and BTB, respectively, in case of ENF.

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A new, simple and sensitive cloud point extraction procedure was presented for the preconcentration and determination of copper(II) ion in food, water and biological samples. The analyte was complexed with a new synthesized reagent, 2-amino-4-(m-tolylazo)pyridine-3-ol (ATAP) as a new complexing agent and Triton X-114 as the surfactant. After centrifugation, dilution of the surfactant-rich phase with 0.

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Rapid, sensitive and validated spectrophotometric methods for the determination of two antiepileptics (gabapentin (GAB) and pregabalin (PRG)) in pure forms and in pharmaceutical formulations was developed. The method is based on the formation of charge transfer complex between drug and the chromogenic reagents quinalizarin (Quinz) and alizarin red S (ARS) producing charge transfer complexes in methanolic medium which showed an absorption maximum at 571 and 528 nm for GAB and 572 and 538 nm for PRG using Quinz and ARS, respectively. The optimization of the reaction conditions such as the type of solvent, reagent concentration and reaction time were investigated.

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A modified selective, highly sensitive and accurate procedure for the determination of trace amounts of cadmium which reacts with 1-(2-benzothiazolylazo)-2-hydroxy-3-naphthoic acid (BTAHNA) to give a deep violet complex with high molar absorptivity (7.05×10(6)Lmol(-1) cm(-1), 3.92×10(7)Lmol(-1)cm(-1), 1.

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A new highly sensitive and specific spectrofluorimetric method has been developed to determine a sympathomimetic drug pseudoephedrine hydrochloride. The present method was based on derivatization with 4-chloro-7-nitrobenzofurazan in phosphate buffer at pH 7.8 to produce a highly fluorescent product which was measured at 532 nm (excitation at 475 nm).

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Two new simple, sensitive, accurate, and precise spectrophotometric methods have been developed and validated for the determination of cefdinir (CFD) in bulk drug and in its pharmaceutical formulations. The first method was based on the reaction of CFD with 1, 2- napthaquinone-4- sulfonic acid sodium (NQS) in an alkaline medium (pH 11) to form an orange-coloured product that was measured at 490 nm. The second method depends on hydrolysis of CFD using 0.

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Studies were carried out, for the first time, to investigate the charge-transfer reactions of ganciclovir as n-electron donor with the sigma-acceptor iodine and various pi-acceptors: 7,7,8,8-tetracyanoquinodimethane; tetracyanoethylene; 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; p-chloranilic acid; 2,3,5,6-tetrabromo-1,4-benzoquinone; 2,3,5,6-tetrachloro-1,4-benzoquinone and 2,4,7-trinitro-9-fluorenone. The formation of the colored charge-transfer complexes was utilized in the development of simple, rapid and accurate spectrophotometric methods for the analysis of ganciclovir in pure form as well as in its pharmaceutical formulation (capsules). Different variables affecting the reactions were studied and optimized.

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Rapid, simple and sensitive validated spectrophotometric methods have been described for the assay of pipazethate HCl (PiCl) and dextromethorphan HBr (DEX) either in pure form or in pharmaceutical formulations. The proposed methods were based on the oxidation of the studied drugs by a known excess of potassium permanganate in acidic medium and estimating the unreacted permanganate with amaranth dye (method A), acid orange II (method B), indigocarmine (method C) and methylene blue (method D), in the same acid medium at a suitable λmax=521, 485, 610 and 664 nm, respectively. Beer's law is obeyed in the concentration range of 2.

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A new simple, very sensitive, selective and accurate procedure for the determination of trace amounts of iron(II) by solid-phase spectrophotometry (SPS) has been developed. The procedure is based on fixation of iron(II) as 2,3-dichloro-6-(3-carboxy-2-hydroxy-1-naphthylazo)quinoxaline on a styrene-divinylbenzene anion-exchange resin. The absorbance of resin sorbed iron(II) complex is measured directly at 743 and 830nm.

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Background: Etodolac (ETD) is a non-steroidal anti-inflamatory antirheumatic drug. A survey of the literature reveals that there is no method available for the determination of ETD in pure form and pharmaceutical formulations by oxidation-reduction reactions.

Results: We describe three simple, sensitive and reproducible spectrophotometric assays (A-C) for the determination of etodolac in pure form and in pharmaceutical formulations.

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