排序方式: 共有27条查询结果,搜索用时 15 毫秒
1.
Hassan A. Zedan M. Alghamdi Seham Sh. Tantawy 《Mathematical Methods in the Applied Sciences》2015,38(17):4357-4364
We study in this paper the Q‐symmetry and conditional Q‐symmetries of Drinfel'd–Sokolov–Wilson equations. The solutions which we obtain in this paper take the form of convergent power series with easily computable components. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
2.
A convenient synthesis of intermediate 4,5‐diamino‐3‐aryl‐1‐phenylpyrazoles 4a – 4c was reported. The different cyclization reactions were carried out with chalcone, 2‐mercaptoacetic acid and p‐anisialdehyde, ethyl chloroformate, glyoxal and thiourea to afford different N and S containing heterocycles. The reaction conditions were compared by conventional heating and microwave irradiation. The structures of the cyclization products were determined by analytical and spectroscopic data. All the synthesized compounds were screened for antibacterial activities in vitro. 相似文献
3.
It is shown that existing equations for predicting the holdups of wakes behind bubbles in three-phase fluidized beds are not entirely satisfactory. A new model is then developed whereby the wake is treated as the sphere-completing volume of a spherical cap bubble, due allowance being made for hydrodynamic interactions between bubbles. The generalized wake equations of Bhatia & Epstein (1974) are applied to compute the ratio of solids holdup in the wakes to that in the remaining liquid of the bed. Using experimental data from the literature, a rational equation is then generated for predicting this ratio from measured variables, and a mechanism for wake solids entrainment is proposed which is consistent with this equation. 相似文献
4.
Yahia Nasser Mabkhot Nahed Ahmed Kaal Seham Alterary Mohammad S. Mubarak Abdulrhman Alsayari Abdullatif Bin Muhsinah 《Journal of heterocyclic chemistry》2019,56(10):2845-2953
Phenacylbromide derivatives constitute a multilateral group of precursors for the synthesis of numerous heterocycles of organic compounds. Briefly, 5‐(2‐bromo‐acetyl)‐substituted‐thiophene derivative has been used as a synthon for synthesis of new thiophene‐containing compounds through the reaction with nucleophilic nitrogen compounds and thioamides. The suggested structures of the newly synthesized thiophene compounds were confirmed and assured with different spectroscopic tools and with CHN elemental analysis. Additionally, the antimicrobial activity of these thiophene compounds was recorded to investigate their potency against various types of bacteria and fungi. Results showed that these compounds exhibit significant inhibitory activity against the growth of tested bacterial and fungal strains and that some derivatives were more potent than the employed reference drugs. 相似文献
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Reaction of phthalaldehydic acid with different substituted aniline as well as hydrazine derivatives
Sherine N. Khattab Seham Y. Hassan Ayman El‐Faham Abdel Moneim M. El Massry Adel Amer 《Journal of heterocyclic chemistry》2007,44(3):617-626
Phthalaldehydic acid 1 is often represented as having two tautomeric forms 1a and 1b. The reaction of phthalaldehydic acid with different aryl amine and heterocyclic aryl hydrazine derivatives afforded different products depending on the reaction conditions such as solvent and temperature. 相似文献
7.
Mohamed A. El‐Borai Hala F. Rizk Seham A. Ibrahim Amira K. Fares 《Journal of heterocyclic chemistry》2019,56(10):2787-2795
5‐Amino‐3‐phenyl‐1‐(2,4,6‐trichlorophenyl)‐1H‐thieno[3,2‐c]pyrazole‐6‐carbonitrile ( 2 ) was designed and synthesized by one‐pot multicomponent reaction. Compound 2 was reacted with different reagents to obtain new condensed moieties with our thienopyrazole skeleton. The compounds were prepared by using environmentally benign techniques as microwave irradiation, ultrasonic irradiation, and ball‐milling. The structure of the prepared compounds was elucidated through spectroscopic methods. The new compounds were evaluated for their in vitro antibacterial and antifungal potentialities. 相似文献
8.
Mohammed A. Huneif Seham M. Alqahtani Alqahtani Abdulwahab Sultan A. Almedhesh Mater H. Mahnashi Muhammad Riaz Najm Ur-Rahman Muhammad Saeed Jan Farhat Ullah Muhammad Aasim Abdul Sadiq 《Molecules (Basel, Switzerland)》2022,27(11)
Diabetes mellitus is a metabolic disorder and is a global challenge to the current medicinal chemists and pharmacologists. This research has been designed to isolate and evaluate antidiabetic bioactives from Fragaria indica. The crude extracts, semi-purified and pure bioactives have been used in all in vitro assays. The in vitro α-glucosidase, α-amylase and DPPH free radical activities have been performed on all plant samples. The initial activities showed that ethyl acetate (Fi.EtAc) was the potent fraction in all the assays. This fraction was initially semi-purified to obtain Fi.EtAc 1–3. Among the semi-purified fractions, Fi.EtAc 2 was dominant, exhibiting potent IC50 values in all the in vitro assays. Based on the potency and availability of materials, Fi.EtAc 2 was subjected to further purification to obtain compounds 1 (2,4-dichloro-6-hydroxy-3,5-dimethoxytoluene) and 2 (2-methyl-6-(4-methylphenyl)-2-hepten-4-one). The two isolated compounds were characterized by mass and NMR analyses. The compounds 1 and 2 showed excellent inhibitions against α-glucosidase (21.45 for 1 and 15.03 for 2 μg/mL), α-amylase (17.65 and 16.56 μg/mL) and DPPH free radicals (7.62 and 14.30 μg/mL). Our study provides baseline research for the antidiabetic bioactives exploration from Fragaria indica. The bioactive compounds can be evaluated in animals-based antidiabetic activity in future. 相似文献
9.
Mamdouh M. Shawki Alaa El Sadieque Seham Elabd Maisa E. Moustafa 《Molecules (Basel, Switzerland)》2022,27(14)
Cancer remains a leading cause of death worldwide, despite extraordinary progress. So, new cancer treatment modalities are needed. Tumor-treating fields (TTFs) use low-intensity, intermediate-frequency alternating electric fields with reported cancer anti-mitotic properties. Moreover, nanomedicine is a promising therapy option for cancer. Numerous cancer types have been treated with nanoparticles, but zinc oxide nanoparticles (ZnO NPs) exhibit biocompatibility. Here, we investigate the activity of TTFs, a sub-lethal dose of ZnO NPs, and their combination on hepatocellular carcinoma (HepG2), the colorectal cancer cell line (HT-29), and breast cancer cell lines (MCF-7). The lethal effect of different ZnO NPs concentrations was assessed by sulforhodamine B sodium salt assay (SRB). The cell death percent was determined by flow cytometer, the genotoxicity was evaluated by comet assay, and the total antioxidant capacity was chemically measured. Our results show that TTFs alone cause cell death of 14, 8, and 17% of HepG2, HT-29, and MCF-7, respectively; 10 µg/mL ZnO NPs was the sub-lethal dose according to SRB results. The combination between TTFs and sub-lethal ZnO NPs increased the cell death to 29, 20, and 33% for HepG2, HT-29, and MCF-7, respectively, without reactive oxygen species increase. Increasing NPs potency using TTFs can be a novel technique in many biomedical applications. 相似文献
10.
Gamal A. H. Mekhemer Hussein A. Khalaf Seham A. A. Mansour Ahmed K. H. Nohman 《Monatshefte für Chemie / Chemical Monthly》2005,136(12):2007-2016
Summary. Consequences of the loading level of sulfate ions (3, 6, and 10-wt%) as well as the source of sulfate (H2SO4 or (NH4)2SO4) on the structural, textural, and surface acid–base properties as well as the impacts on catalytic activity towards 2-propanol
conversions on γ-Al2O3 and on aluminum hydroxide gel is described. Structural investigations of the catalysts by XRD revealed that the sulfation
processes do not remarkably affect the γ-phase of alumina irrespective of the sulfate content or source. N2-adsorption at 77 K indicated that sulfated gel catalysts exhibit the highest SBET areas and, in general, SBET for all catalysts were found to decrease with the increase of sulfate content, such a decrease is more pronounced for the
10% loaded catalysts. Pyridine adsorption as followed by FTIR indicated that sulfation of alumina increases the strength of
its Lewis acid sites and creates Br?nsted acidity in the case of highly loaded catalysts. The catalytic decomposition of 2-propanol in the gas phase indicated that,
amongst all the catalysts investigated, the 6% loaded ones exhibited 100% activity (2-propanol conversion) and the highest
propene (dehydration product) selectivity. 相似文献