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71.
Theodor W. Güntert Horst H. A. Linde Mohamed S. Ragab Sigrid Spengel 《Helvetica chimica acta》1976,59(6):2138-2148
Synthesis of a homologous steroidal 17β-pyrrolinone. We describe the synthesis of 4′-[(3β-Hydroxy-androst-5-en-17β-yl)methyl]-3′-pyrrolin-2′-one ( 15 ) starting from 3β-acetoxy-23-diazo-21,24-dinorchol-6-en-22-one ( 1 ). 相似文献
72.
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74.
Inas A. Ahmed Ahmed H. Ragab Mohamed A. Habila Taghrid S. Alomar Enas H. Aljuhani 《Molecules (Basel, Switzerland)》2021,26(9)
In this work, low-cost and readily available limestone was converted into nanolimestone chitosan and mixed with alginate powder and precipitate to form a triple nanocomposite, namely limestone—chitosan–alginate (NLS/Cs/Alg.), which was used as an adsorbent for the removal of brilliant green (BG) and Congo red (CR) dyes in aqueous solutions. The adsorption studies were conducted under varying parameters, including contact time, temperature, concentration, and pH. The NLS/Cs/Alg. was characterized by SEM, FTIR, BET, and TEM techniques. The SEM images revealed that the NLS/Cs/Alg. surface structure had interconnected pores, which could easily trap the pollutants. The BET analysis established the surface area to be 20.45 m2/g. The recorded maximum experimental adsorption capacities were 2250 and 2020 mg/g for CR and BG, respectively. The adsorption processes had a good fit to the kinetic pseudo second order, which suggests that the removal mechanism was controlled by physical adsorption. The CR and BG equilibrium data had a good fit for the Freundlich isotherm, suggesting that adsorption processes occurred on the heterogeneous surface with a multilayer formation on the NLS/Cs/Alg. at equilibrium. The enthalpy change (ΔH0) was 37.7 KJ mol−1 for CR and 8.71 KJ mol−1 for BG, while the entropy change (ΔS0) was 89.1 J K−1 mol−1 for CR and 79.1 J K−1 mol−1 BG, indicating that the adsorption process was endothermic and spontaneous in nature. 相似文献
75.
Saleh HM El-Henawee MM Ragab GH El-Hay SS 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,67(5):1284-1289
A simple, accurate, precise and sensitive colorimetric method for the determination of some skeletal muscle relaxant drugs, namely orphenadrine citrate (I), baclofen (II), antihistaminic drugs as acrivastine (III) and fexofenadine hydrochloride (IV) is described. This method is based on the formation of charge transfer complex with 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) in non-aqueous medium. The orange color products were measured at 472, 465, 475 and 469 nm for drugs I, II, III and IV, respectively. The optimization of various experimental conditions was described. Beer's Law was obeyed in the range (2.5-17.5), (5-70), (2.5-25) and (10-50)microg/ml for drugs I, II, III and IV, respectively. The molar absorptivity (epsilon), sandell sensitivity, detection((LOD)) and quantitation limits((LOQ)) are calculated. The procedure was favorably applied for determination of certain pharmaceutical dosage forms containing the studied drugs. The obtained results were compared with the official and reported methods. There were no significant differences between proposed, reported and the official methods. 相似文献
76.
Mohamed F. Abdelhameed Gihan F. Asaad Tamer I. M. Ragab Rania F. Ahmed Abd El-Nasser G. El Gendy Sahar S. Abd El-Rahman Abdelbaset M. Elgamal Abdelsamed I. Elshamy 《Molecules (Basel, Switzerland)》2021,26(19)
Different parts of Araucaria bidiwillii (bunya pin) trees, such as nuts, seeds, bark, and shoots, are widely used in cooking, tea, and traditional medicines around the world. The shoots essential oil (EO) has not yet been studied. Herein, the chemical profile of A. bidiwillii shoots EO (ABSEO) was created by GC–MS analysis. Additionally, the in vivo oral and topical anti-inflammatory effect against carrageenan-induced models, as well as antipyretic potentiality of ABSEO and its nanoemulsion were evaluated. Forty-three terpenoid components were identified and categorized as mono- (42.94%), sesqui- (31.66%), and diterpenes (23.74%). The main compounds of the ABSEO were beyerene (20.81%), α-pinene (16.21%), D-limonene (14.22%), germacrene D (6.69%), β-humulene (4.14%), and sabinene (4.12%). The ABSEO and its nanoemulsion exhibited significant inflammation suppression in carrageenan-induced rat paw edema model, in both oral (50 and 100 mg/kg) and topical (5% in soyabean oil) routes, compared to the control and reference drugs groups. All the results demonstrated the significant inflammation reduction via the inflammatory cytokines (IL-1β and IL8), nitrosative (NO), and prostaglandin E2 (PGE2) supported by the histopathological studies and immunohistochemical assessment of MMP-9 and NF-κβ levels in paw tissues. Moreover, the oral administration of ABSEO and its nanoemulsion (50 and 100 mg/kg) exhibited antipyretic activity in rats, demonstrated by the inhibition of hyperthermia induced by intramuscular injection of brewer’s yeast. These findings advised that the use of ABSEO and its nanoemulsion against numerous inflammatory and hyperthermia ailments that could be attributed to its active constituents. 相似文献
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78.
Abass Mohamed Ragab Ibrahim Asmaa Bendary EL-Masry Eman Hassan Abou-Mesalam Mamdouh Mohamed 《Journal of Radioanalytical and Nuclear Chemistry》2021,329(2):849-855
Journal of Radioanalytical and Nuclear Chemistry - Gamma radiation at varying radiation doses was utilized to produce polyacrylonitrile ball clay nanocomposites (PAN/BC). Various... 相似文献
79.
In this paper we discuss the coupled dynamics, following from a suitable Lagrangian, of a harmonic or wave map ? and Einstein’s gravitation described by a metric g. The main results concern energy conditions for wave maps, harmonic maps from warped product manifolds, and wave maps from wave-like Lorentzian manifolds. 相似文献
80.
The transient current, electrical conductivity, dielectric constant (ε′), and dielectric loss factor (ε″) of starch and methylcellulose homopolymers and their blends with various compositions were studied under different conditions. The x-ray diffraction pattern was obtained for individual polymers and 50:50 wt/wt% blend sample to identify both the structure and degree of crystallinity. From transient current, the ionic and electronic transfer number as well as charge carrier density and drift mobility were determined. The values of activation energy in the temperature range 30–90 °C indicate that the conduction mechanism is due to combined electronic and ionic processes, while in the temperature range 100–160 °C, electronic contribution is predominant. The complex dielectric data of the present samples in an extended frequency and temperature range appear as different relaxation processes, which are connected with polymer dynamics. 相似文献