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Ashraf S. A. El-Sayed 한국미생물학회 2011 The journal of microbiology Vol.49 No.1
L-Methioninase was purified to electrophoretic homogeneity from cultures of Aspergillus flavipes using anionexchange and gel filtration chromatography by 12.1 fold compared to the crude enzyme preparation. The purified enzyme had a molecular mass of 47 kDa under denaturing conditions and an isoelectric point of 5.8 with no structural glycosyl residues. The enzyme had optimum activity at pH 7.8 and pH stability from 6.8-8.0 at 35°C. The enzyme appeared to be catalytically stable below 40°C. The enzyme activity was strongly inhibited by DL-propargylglycine, hydroxylamine, PMSF, 2-mercaptoethanol, Hg^(2+), Cu^(2+), and Fe^(2+), with slight inhibition by Triton X-100. A. flavipes L-methioninase has a higher catalytic affinity towards L-methionine (Km, 6.5 mM and Kcat, 14.1 S^(-1)) followed by a relative demethiolating activity to L-homocysteine (Km, 12 mM and Kcat, 9.3 S^(-1)). The enzyme has two absorption maxima at 280 and 420 nm,typical of other PLP-enzymes. Apo-L-methioninase has the ability to reconstitute its structural catalytic state completely upon addition of 0.15 mM PLP. L-Methioninase has neither an appreciable effect on liver function, platelet aggregation, nor hemolysis of human blood. The purified L-methioninase from solid cultures of A. flavipes displayed unique biochemical and catalytic properties over the currently applied Pseudomonad enzyme.
Dynamic Clustering and User Association in Wireless Small-Cell Networks With Social Considerations
Ashraf, Muhammad Ikram,Bennis, Mehdi,Saad, Walid,Katz, Marcos,Hong, Choong-Seon IEEE 2017 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY Vol.66 No.7
<P>In this paper, a novel social network-aware user association in wireless small cell networks with underlaid device-to-device (D2D) communication is investigated. The proposed approach exploits strategic social relationships between user equipments (UEs) and their physical proximity to optimize the overall network performance. This problem is formulated as a matching game between UEs and their serving nodes (SNs) in which, an SN can be a small cell base station (SCBS) or an important UE with D2D capabilities. The problem is cast as a many-to-one matching game in which UEs and SNs rank one another using preference relations that capture both the wireless aspects (i.e., received signal strength, traffic load, etc.) and users' social ties (e.g., UE proximity and social distance). Due to the combinatorial nature of the network-wide UE-SN matching, the problem is decomposed into a dynamic clustering problem in which SCBSs are grouped into disjoint clusters based on mutual interference. Subsequently, an UE-SN matching game is carried out per cluster. The game under consideration is shown to belong to a class of matching games with externalities arising from interference and peer effects due to users social distance, enabling UEs and SNs to interact with one another until reaching a stable matching. Simulation results show that the proposed social-aware user association approach yields significant performance gains, reaching up to 26%, 24%, and 31% for 5th, 50th, and 95th percentiles for UE throughputs, respectively, as compared to the classical social-unaware baseline.</P>
( Ashraf M. Zenkour ) 호남수학회 2016 호남수학학술지 Vol.38 No.3
This paper investigates the effect of dual-phase-lags on a thermoviscoelastic orthotropic solid with a cylindrical cavity. The cylindrical cavity is subjected to a thermal shock varying heat and its material is taken to be of Kelvin-Voigt type. The phase-lag thermoelastic model, Lord and Shulman`s model and the coupled thermoelasticity model are employed to study the thermomechanical coupling, thermal and mechanical relaxation (viscous) effects. Numerical solutions for temperature, displacement and thermal stresses are obtained by using the method of Laplace transforms. Numerical results are plotted to illustrate the effect phase-lags, viscoelasticity, and the variability thermal conductivity parameter on the studied fields. The variations of all field quantities in the context of dual-phase-lags and coupled thermoelasticity models follow similar trends while the Lord and Shulman`s model may be different. The influence of viscosity parameter and variability of thermal conductivity is very pronounced on temperature and thermal stresses of the thermoviscoelastic solids.
ON SEMIDERIVATIONS IN 3-PRIME NEAR-RINGS
Ashraf, Mohammad,Boua, Abdelkarim Korean Mathematical Society 2016 대한수학회논문집 Vol.31 No.3
In the present paper, we expand the domain of work on the concept of semiderivations in 3-prime near-rings through the study of structure and commutativity of near-rings admitting semiderivations satisfying certain differential identities. Moreover, several examples have been provided at places which show that the assumptions in the hypotheses of various theorems are not altogether superfluous.
Ashraf Youssef Nasr,Rasha A,Alshali 대한해부학회 2020 Anatomy & Cell Biology Vol.53 No.2
Adriamycin (ADR) efficacy in cancer chemotherapy is well-established. However, ADR-induced cardiotoxicity remains a significant challenge. Aged garlic extract (AGE) is a natural polyphenol with high antioxidant potential. This study was planned to determine the cytoprotective and antioxidant actions of AGE against the cardiotoxic effect of ADR in rats. Six equal groups, control, ADR-treated (single dose of 10 mg/kg on day 8); AGE-treated (one dose of 250 mg/kg for 14 days); AGE plus ADR-treated (one dose of 250 mg/kg AGE for one week plus ADR injection of 10 mg/kg on day 8); ADR plus AGE-treated (single ADR injection of 10 mg/kg on day 8 plus AGE of 250 mg/kg once from 8th to 14th day); combined AGE plus ADR plus AGE-treated (one dose of 250 mg/kg AGE for 14 days plus single ADR injection of 10 mg/kg on day 8). Sera and cardiac samples were collected on day 15 and prepared for histological, ultrastructural and biochemical study. Disorganization, focal degeneration and necrosis with apoptotic changes of the cardiac myofibrils were observed in ADR-treated rats. Also, reduction in level of total creatine kinase, lactic dehydrogenase, alkaline phosphatase enzymes, glutathione, glutathione- peroxidase, superoxide dismutase, and catalase activities and elevation in malondialdehyde concentration were detected in ADR-treated rats. However, combination of AGE attenuated most of the histopathological, ultrastructural, and biochemical changes induced by ADR. Combination of AGE attenuated the cardiotoxic effects-induced by ADR through its antioxidant and cytoprotective potentials. Therefore, AGE can use as adjunct during administration of ADR in cancer therapy.
Fungal biopriming increases the resistance of wheat to abiotic stress
Ashraf S. A. El-Sayed,Hanan E. Dief,El-Sayed A. Hashem,Ahmed M. Desouky,Zamarud Shah,Salwa Fawzan 한국식물생명공학회 2022 JOURNAL OF PLANT BIOTECHNOLOGY Vol.49 No.2
Increasing soil salinity is one of the global challenges that the agriculture sector in Egypt has been facing; 33% of the cultivated land in Egypt, which includes merely 3% of the entire land area, is already salinized. The present review sheds light on the role of fungal biopriming, a technique in which hydrated seeds are inoculated with beneficial fungal flora, in mitigating the deleterious influence of NaCl tension. Endophytic fungi were recognized to be able to interact with several plant species, markedly contributing to the mitigation of NaCl stress in these plants, such that some plants get impoverished to their absent associated microbes under stressful conditions
Quality of Life among Iranian Infertile Women in Postmenopausal Period: A Cross-sectional Study
( Ashraf Direkvand-moghadam ),( Ali Delpisheh ),( Ali Montazeri ),( Kourosh Sayehmiri ) 대한폐경학회 2016 대한폐경학회지 Vol.22 No.2
Objective: Infertility has a significant impact on a women``s quality of life (QOL). Infertile women face with physical and mental challenges during their postmenopausal period. Therefore, the present study aimed to evaluate the QOL among Iranian infertile women in the postmenopausal period using a valid and reliable instrument. Methods: In this cross-sectional study both snowball and social networking methods were used for sampling. Two demographic and QOL questionnaire were used for data collection. The QOL questionnaire includes 41 items which measure the QOL in five dimensions: socioeconomic, mental health, religiousness, physical health and future imagining. Data analyzed was carried out in IBM SPSS ver. 20.0 using descriptive statistic, x² test, and Fisher test. A P value of 0.01 or less was considered significant. Results: Overall 211 eligible participants were studied. Some participants obtained full score on socioeconomic, religiousness, physical health and future imagining dimensions of QOL but none on the mental health dimension of the QOL. Only, 6.6% of study participants have a good QOL. There was a significant relationship between age and financial provider whit status of QOL. Conclusion: Most Iranian infertile women in the postmenopausal period have poor or moderate QOL. Therefore, improving the QOL among these women should be considered. (J Menopausal Med 2016;22:108-113)
Anticancer activities of some newly synthesized pyrazole and pyrimidine derivatives
Ashraf M. Mohamed,Weal A. El-Sayed,Musaed A. Alsharari,Husam R. M. Al-Qalawi,Mousa O. Germoush 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.9
A series of pyrazolopyridine and pyridopyrimidinederivatives 2–6 were newly synthesized using3,5-bisarylmethylene-1-methylpiperidone as the startingmaterial. The anticancer activities of the synthesizedcompounds were evaluated using 59 different human tumorcell lines, representing cancers of CNS, ovary, renal,breast, colon, lung, leukemia, and melanoma, prostate aswell as kidney. Some of the tested compounds, especiallythose with a fluorine substituent at the para-position in thephenyl ring and those with a pyridopyrimidine-2-thionewith a free –NH or –SH, exhibited greater in vitro antitumoractivities at low concentrations (log 10 [GI50] =-4.6) against the human tumor cell lines. Additionally,some of the compounds had moderate inhibitory effects onthe growth of the cancer cell lines. The detailed synthesis,spectroscopic data and antitumor properties of the synthesizedcompounds are reported.
Benzylamides from Salvadora persica
Ashraf Taha Khalil 대한약학회 2006 Archives of Pharmacal Research Vol.29 No.11
A phytochemical investigation of stems from Salvadora persica resulted in the first isolation of four benzylamides from a natural source. The isolated compounds were identified as butanediamide, N1,N4-bis(phenylmethyl)-2(S)-hydroxy-butanediamide (1), N-benzyl-2-phenylacetamide (2), N-benzylbenzamide (3) and benzylurea (4). The structure elucidation was accomplished using spectroscopic methods, especially 2D NMR and HREIMS. Compound 2 revealed a significant inhibitory effect on human collagen-induced platelet aggregation, and a moderate antibacterial activity against Escherichia coli.