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11.
Riad Emil Michael Emam Manal Asem Ebeid Nahed Hassan El-bayoumy Ahmed Sami Sallam Khaled Mohamed Mehany Nagy Lahzy Fathy Shadia Abdel-Hamid 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(3):1389-1396
Journal of Radioanalytical and Nuclear Chemistry - The aim of this study was the development and analytically validation of a radioimmunoassay system for the measurement of the serum ferritin... 相似文献
12.
Modelling non-Fourier heat conduction with periodic thermal oscillation using the finite integral transform 总被引:4,自引:0,他引:4
Bishri Abdel-Hamid 《Applied Mathematical Modelling》1999,23(12):899-914
The non-Fourier heat conduction in a finite medium subjected to a periodic heat flux is modelled using the finite integral transform technique and an analytic solution is obtained. An analogy between thermal oscillation and oscillation of mechanical and electrical systems is drawn. A transition criterion from the non-Fourier heat conduction formulation to the Fourier formulation is obtained and a simple analytical expression of the phase and amplitude of thermal oscillation is derived. 相似文献
13.
The electrochemistry of the bis(1,4,7-triazacyclodecane) cobalt(III) complex at a mercury electrode, HMDE, in aqueous Britton–Robinson buffer solutions was investigated using cyclic voltammetry, double-potential-step chronoamperometry and chronocoulometry. The cyclic voltammetric data were analyzed by digital simulation to confirm and to measure the heterogeneous and homogeneous parameters for the suggested electrode mechanism. Generally, the complex is electrochemically reduced giving rise to two cyclic voltammetric waves. The first wave is a diffusion-controlled reversible wave. It is assigned to the stable Co(III)/Co(II) redox couple. The second one is found to be irreversible and corresponding to a reduction of Co(II) to Co(I) species. The monovalent cobalt, highly unstable, is rapidly protonated, and then forms cobalt hydride. The hydride decomposes to hydrogen molecules and regenerates Co(II) species following a disproportionation pathway. The overall reduction mechanism is concluded to be an EECC kinetics. 相似文献
14.
Ohne Zusammenfassung 相似文献
15.
Refat Abdel-Hamid 《Monatshefte für Chemie / Chemical Monthly》1988,119(4):429-438
The electrochemical reduction of phenolphthalein in dimethylformamide solution containing 0.1 mol dm–3 tetraethylammonium perchlorate at the hanging dropping mercury electrode showed an irreversible two-electron voltammetric peak. It was found that the CV peak is diffusion-controlled at low concentrations (0.4 mmol dm–3). At higher concentration (0.5 mmol dm–3) a postpeak was developed besides the diffusion-controlled one which was assigned to the adsorbed depolarizer. Cyclic voltammetric studies indicate that phenolphthalein follows an ECEC mechanism. Convolution and deconvolution potential sweep voltammetry confirm that mechanism.
Mechanismus der voltametrischen Reduktion von Phenolphthalein an der Quecksilberelektrode inDMF
Zusammenfassung Die elektrochemische Reduktion von Phenolphthalein an der tropfenden Quecksilberelektrode in Dimethylformamidlösung mit einem Gehalt von 0.1 mol dm–3 an Tetraethylammoniumperchlorat zeigte ein irreversibles voltametrisches Maximum für zwei Elektronen. Es zeigte sich, daß der CV-Peak bei niederen Konzentrationen (0.4 mmol dm–3) diffusionskontrolliert ist. Bei höheren Konzentrationen (0.5 mmol dm–3) entwickelte sich ein nachkommendes Maximum neben dem diffusionskontrollierten, welches dem adsorbierten Depolarisator zugeordnet wurde. Untersuchungen mittels cyclischer Voltametrie zeigten, daß Phenolphthalein einem ECEC-Mechanismus folgt. Konvolutions-und Dekonvolutions-Potential-Sweep-Voltametrie bestätigten diesen Mechanismus.相似文献
16.
Tasneem Mokhtar Radwan Maher Abdel-Aziz El-Hashash Ashraf Abdel-Hamid Farouk Wasfy Suzan Abdelhalim Abdallah 《Journal of heterocyclic chemistry》2020,57(3):1111-1122
Heterocyclic compounds with different heterocycle moieties, namely benzoxazinone, benzimidazole, quinazolinone, and benzofuranone heterocyclic rings, were synthesized, characterized, and evaluated for their anticancer activity against human hepatocellular carcinoma cell line (HepG2) using sulforhodamine B (SRB) and dimethylthiazol-diphenyltetrazolium bromide (MTT) assays. Also, their cytotoxic activities were tested against human epithelioid carcinoma (Hela) cell line in comparison with normal cell, amniotic epithelial (WISH) cell line, as an in vitro toxicity estimation model. The results showed clearly that 2-(2-benzyl-4-oxoquinazolin-3(4H)-yl)acetohydrazide 4 is the most potent antioxidant and anticancer agents. Although, 3-amino-2-benzylquinazolin-4(3H)-one 5 is less potent anticancer agent against Hela but it is more safe against normal cell (WISH). 相似文献
17.
El-Moselhy MA Abdel-Hamid NM Abdel-Raheim SR 《Applied biochemistry and biotechnology》2009,152(3):449-459
Despite the fact that dietary habits and lifestyles are incredibly advancing, gastric ulceration is still a terrible complaint.
Extensive use of non-steroidal anti-inflammatory drugs (NSAIDs) and alcohol, in addition to stress, are all predisposing factors
for ulcers. Most medical treatments are always time consuming and not efficient or satisfactory to the patients. Cardiovascular
patients always need NSAIDs, or mostly cannot quit alcohols, while using many cardiovascular drugs. We aim to study a possible
benefit of a common nitrogen oxide donor, anti-anginal drug, nicorandil [N-(2-hydroxyethyl) nicotinamide nitrate ester], in managing acute gastric ulcers through studying its effect on some relevant
intermediates to ulcerogenesis as lipid peroxidation, tumor necrosis factor-alpha (TNF-α), and nitric oxide (NO). In addition,
gastric mucosal histology was studied to pursue the drug effects on tissue level. Our study revealed that both indomethacin
and alcohol induced gastric ulcer mainly through up-regulation of gastric mucosal lipid peroxidation, local tissue inflammation,
leukocytic infiltration, and necrosis. Both ulcerogens significantly elevated TNF-α and decreased NO, initiating ulcer formation.
Nicorandil pretreatment depicted a higher preventive index in indomethacin- (89.8%) and alcohol-induced (77.7%) acute ulceration.
On the tissue level, it also protected the gastric mucosa combating leukocyte infiltration and tissue congestion. Nicorandil
protected tissue necrosis through decreasing oxidative stress, elevating NO levels, and down-regulating the ulcerogen-induced
TNF-α elevation and improved sub-mucosal blood supply. We conclude that nicorandil may be a suitable bimodal treatment for
cardiovascular patients who are at high risk of gastric ulcers by using variable analgesics to alleviate possible cardiac
pain episodes, and probably frequent doses will offer a more established and long-lasting protection. 相似文献
18.
This communication presents the optical studies associated with transition doped (metallic)-neutral (semiconductor or insulator) state for conducting polymers. Special attention is focused on the electronic properties of polyaniline. The interconversion of different oxidation states of polyanilines has been studied by chemical and radiolytic methods. The polyaniline system is described by three sets of chromophores of three different oxidation states: fully reduced leucoemeraldine base (LB), partially oxidized emeraldine base (EB), and fully oxidized pernigraniline (PB). Each oxidation state can exist in its protonated form by treatment with an acid. All members of polyaniline family are spectroscopically distinguishable. The radiolytic study presents evidence that the polyaniline can exist in a continuum of oxidation states. The highly conducting form of polymer, i.e. emeraldine salt can be converted by using ionizing radiation into leucoemeraldine salt. The leucoemeraldine base is the final product of radiolysis of emeraldine base solution. The fully oxidized form of polyaniline can also be obtained by the irradiation of EB in the presence of CCl4 or chlorobenzene. 相似文献
19.
M. F. Barakat M. M. Abdel-Hamid 《Journal of Radioanalytical and Nuclear Chemistry》1996,207(1):171-182
Polyvalent ions are very sensitive to gamma irradiation in aqueous solutions. The present work is a part of a more comprehensive study dealing with the stabilization of certain oxidation states of some polyvalent ions during their gamma irradiation in aqueous systems. Sulphite ions, being well known reducing agents has been used for stabilizing Fe(II) ions in aqueous solutions during gamma radiolysis. Fe(II) ions in solution are known to be readily oxidized by gamma radiations in such a way that a 10–3N solution decays completely in about 2 hours at a dose rate 310 Gy/hr. In presence of an excess of sulphite ions it was found that Fe(II) ions were stabilized for extended time periods depending on the amount of sulphite ions used. The conditions of stabilization and its limits in the studied case has been identified. 相似文献
20.
Mohamed A.H. Kharaba Ahmed M.G. Nassar Abdel-Hamid A. Youssef Mohamed M. El-Banna 《中国化学会会志》1989,36(3):211-218
The rates of reaction of a series of substituted naphthoxides with 1-chloro-2,4-dinitrobenzene in methanol, and the pKa values of the naphthols in 50% methanol have been measured. A linear free energy relationship applies well to these reactions. The rate constants are correlated with the pKa values of the corresponding naphthols via the Brönsted equation giving a β values of 0.94. A linear correlation between ΔH? and ΔS? is indicative of single mechanism. The nmr spectra of the substituted naphthols have been measured in DMSO·d6. 相似文献