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      • SCIESCOPUSKCI등재

        Bioactive Levan-Type Exopolysaccharide Produced by Pantoea agglomerans ZMR7: Characterization and Optimization for Enhanced Production

        ( Safaa A. S. Al-qaysi ),( Halah Al-haideri ),( Sana M. Al-shimmary ),( Jasim M. Abdulhameed ),( Othman I. Alajrawy ),( Mohammad M. Al-halbosiy ),( Tarek A. A. Moussa ),( Mohamed G. Farahat ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.5

        Levan is an industrially important, functional biopolymer with considerable applications in the food and pharmaceutical fields owing to its safety and biocompatibility. Here, levan-type exopolysaccharide produced by Pantoea agglomerans ZMR7 was purified by cold ethanol precipitation and characterized using TLC, FTIR, <sup>1</sup>H, and <sup>13</sup>C NMR spectroscopy. The maximum production of levan (28.4 g/l) was achieved when sucrose and ammonium chloride were used as carbon and nitrogen sources, respectively, at 35°C and an initial pH of 8.0. Some biomedical applications of levan like antitumor, antiparasitic, and antioxidant activities were investigated in vitro. The results revealed the ability of levan at different concentrations to decrease the viability of rhabdomyosarcoma and breast cancer cells compared with untreated cancer cells. Levan appeared also to have high antiparasitic activity against the promastigote of Leishmania tropica. Furthermore, levan had strong DPPH radical scavenging (antioxidant) activity. These findings suggest that levan produced by P. agglomerans ZMR7 can serve as a natural biopolymer candidate for the pharmaceutical and medical fields.

      • SCOPUSKCI등재

        Thiazolylazo 화합물의 분광학적, 자기적, 그리고 열적성질

        Masoud, M.S.,Mohamed, G.B.,Abdul-Razek Y.H.,Ali A.E.,Khairy F.N. 대한화학회 2002 대한화학회지 Vol.46 No.2

        Thiazolylazo 화합물과 barbituric산, uracil, thiouracil, citrazinic산 chromotrotropic산, gallict산, pyrogallol 그리고 salicylic산의 Co(II), Ni(II) 그리고 Cu(II) 착화합물의 제조하였고, $^1H$ NMR, IR, 그리고 전기 흡수 스펙트럼에 대한 pHdudgid에 의하여 규명하였다. 이온화형태, 전기적 전이 그리고 해리상수에 대하여 설명하였다. 구리 착화합물은 등방형 ESR스펙트럼이었으며 자기적으로 궤도 기여를 갖는 묽은 성질이었다. 상세한 DTA데이타를 얻었고, 그 결과를 토론하였다. The thiazolylazo compounds and their Co(II), Ni(II) and Cu(II) complexes of barbituric acid, uracil, thiouracil, citrazinic acid, chromotropic acid, gallic acid, pyrogallol and salicylic acid were pre-pared and characterized by $^1H$ NMR , IR and the effect of pH on the electronic absorption spectra . The mode of ionization, the electronic transitions and the dissociation constants were discussed. The stoichiometries of the complexes were of 1:1, 2:1 and 3:2 (M:L). The copper complexes are of isotropic ESR spectra (except that of gallic acid which showed a complicated one) and are of magnetically diluted behaviour with orbital con-tribution. Detailed DTA data were obtained and discussed.

      • SCISCIESCOPUS

        The stimulatory effects of Stewartia koreana extract on the proliferation and migration of fibroblasts and the wound healing activity of the extract in mice

        Lee, T.H.,Lee, G.W.,Park, K.H.,Mohamed, M.A.A.,Bang, M.H.,Baek, Y.S.,Son, Y.,Chung, D.K.,Baek, N.-I.,Kim, J. Spandidos Publications 2014 INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE Vol.34 No.1

        Stewartia koreana (S. koreana) has been used in the treatment of inflammatory diseases, such as acute gastroenteritis and aches, in Korean folk medicine and has been reported to have a number of biological activities, such as anti-inflammatory activity and the promotion of angiogenesis. In this study, we aimed to determine the effects of S. koreana extract (SKE) and its components on dermal fibroblast growth and migration, and to investigate the wound healing activity of the extract in mice. In vitro experiments revealed that the numbers of SKE-treated cells increased by approximately 2.5- and 3.7-fold with 50 and 100 mu g/ml of SKE, respectively. 5-bromo-2'-deoxy-uridine (BrdU) incorporation was also increased in the SKE-treated cells by 2.3-fold. SKE promoted the migration of human skin fibroblasts and, among the isolated compounds, hyperin increased the proliferation and migration of the fibroblasts to almost the same degree as SKE. Western blot analysis demonstrated that SKE stimulated the MEK/ERK1/2 and PI3K/Akt signaling pathways. In in vivo experiments, the SKE-treated wound lesions of mice decreased by approximately 7% in diameter after 2 days of treatment with SKE compared with the wound lesions on the 1st day of the experiment. On the 9th day of treatment, the diameter of the lesions was further reduced by approximately 83% in the SKE-treated wound areas compared with the wound areas on the 1st day of treatment. Our results demonstrate that methanol extracts of S. koreana leaves promote the proliferation and migration of skin fibroblasts and possess effective wound healing activity through the activation of the MEK/ERK1/2 and PI3K/Akt signaling pathways. Hyperin was identified as an active compound responsible for the stimulation of fibroblast growth and migration.

      • SCISCIESCOPUS

        On the contributions of different micromechanisms for enhancement in the strength of TI-6Al-4V alloy upon B addition: A nanomechanical analysis

        Seok, M.Y.,Zhao, Y.,Lee, J.A.,Mohamed, R.M.,Al-Harbi, L.M.,Al-Ghamdi, M.S.,Singh, G.,Ramamurty, U.,Jang, J.i. Elsevier Sequoia 2016 Materials science & engineering Structural materia Vol.649 No.-

        <P>The addition of small amount of boron to Ti and it alloys refines the as-cast microstructure and enhances the mechanical properties. In this paper, we employ nanoindentation on each of the constituent phases in the microstructure and 'rule-of-mixture' type analysis to examine their relative contributions to the strength enhancement in a Ti-6Al-4V alloy modified with 0.3 wt% B. Our results indicate to two main contributors to the relatively higher flow strength of B-modified alloy vis-a-vis the base alloy: (a) strengthening of alpha phase due to the reduction in the effective slip length that occurs as a result of the microstructural refinement that occurs upon B addition, and (b) composite strengthening caused by the TiB whiskers present in the alloy. (C) 2015 Elsevier B.V. All rights reserved.</P>

      • Construction Claims Prediction and Decision Awareness Framework using Artificial Neural Networks and Backward Optimization

        Hosny, Ossama A.,Elbarkouky, Mohamed M.G.,Elhakeem, Ahmed Korea Institute of Construction Engineering and Ma 2015 Journal of construction engineering and project ma Vol.5 No.1

        This paper presents optimized artificial neural networks (ANNs) claims prediction and decision awareness framework that guides owner organizations in their pre-bid construction project decisions to minimize claims. The framework is composed of two genetic optimization ANNs models: a Claims Impact Prediction Model (CIPM), and a Decision Awareness Model (DAM). The CIPM is composed of three separate ANNs that predict the cost and time impacts of the possible claims that may arise in a project. The models also predict the expected types of relationship between the owner and the contractor based on their behavioral and technical decisions during the bidding phase of the project. The framework is implemented using actual data from international projects in the Middle East and Egypt (projects owned by either public or private local organizations who hired international prime contractors to deliver the projects). Literature review, interviews with pertinent experts in the Middle East, and lessons learned from several international construction projects in Egypt determined the input decision variables of the CIPM. The ANNs training, which has been implemented in a spreadsheet environment, was optimized using genetic algorithm (GA). Different weights were assigned as variables to the different layers of each ANN and the total square error was used as the objective function to be minimized. Data was collected from thirty-two international construction projects in order to train and test the ANNs of the CIPM, which predicted cost overruns, schedule delays, and relationships between contracting parties. A genetic optimization backward analysis technique was then applied to develop the Decision Awareness Model (DAM). The DAM combined the three artificial neural networks of the CIPM to assist project owners in setting optimum values for their behavioral and technical decision variables. It implements an intelligent user-friendly input interface which helps project owners in visualizing the impact of their decisions on the project's total cost, original duration, and expected owner-contractor relationship. The framework presents a unique and transparent hybrid genetic algorithm-ANNs training and testing method. It has been implemented in a spreadsheet environment using MS Excel$^{(R)}$ and EVOLVERTM V.5.5. It provides projects' owners of a decision-support tool that raises their awareness regarding their pre-bid decisions for a construction project.

      • KCI등재

        Anti-cancer Effect of Hyoscyamus muticus Extract via Its Activation of Fas/FasL-ASK1-p38 Pathway

        Amer Ali Abd El-Hafeez,Hala Mohamed M. Marzouk,Mohamed A. A. Abdelhamid,Hazim O. Khalifa,Tamer H. A. Hasanin,Ahmed G. K. Habib,Fatma Mahmoud Abdelwahed,Fatma M. Barakat,Eslam M. Bastawy,Eman M. B. Abd 한국생물공학회 2022 Biotechnology and Bioprocess Engineering Vol.27 No.5

        Hyoscyamus muticus L. is a traditional medicine used as antispasmodic and sedative. Herein, we aimed to determine the phytochemical constituents and for the first time its anti-cancer activities. The phytochemical constituents of the different extracts were evaluated by calorimetric methods. The anti-cancer activities of the extracts were tested against leukemia, breast, renal, and prostate cancers cell lines. 4, 6-Diamidino-2-phenylindole (DAPI) staining, flow cytometric analysis, knockdown of ASK1, and reactive oxygen species (ROS) production were evaluated to clarify the mechanism of action. Phytochemical screening confirmed the presence of wide range of phytoconstituents. Hyoscyamus muticus methanolic extracts (HMME) showed the highest anti-cancer activities against leukemia, breast, renal, and prostate cancers as compared to ethanol and aqueous extracts. Specifically, HMME exerted cytotoxic effect against the MDA-MB-231 and MDA-MB-468 triple-negative breast cancer (TNBC) cell lines with IC50 values of 8.75 and 7.25 μg/mL, respectively. Mechanistically, DAPI staining and flow cytometric analysis revealed that HMME induces apoptosis via the death receptor, FAS, but not the mitochondrial pathway. Moreover, ASK1 and p38 were rapidly activated in response to HMME, and knockdown of ASK1 by a small interference of RNA specific to Ask1 attenuated p38 and caspase-3 activation and suppressed apoptosis, implying that HMME-induced apoptosis relies on the ASK1-p38-caspase-3 pathway. Furthermore, we confirmed that cellular ROS generation was a critical mediator in HMME-induced apoptosis because the ROSscavenger N-acetyl cysteine significantly decreased the phosphorylation of ASK1 and HMME-induced apoptosis. Our results confirmed HMME cytotoxic effects in TNBCs via ROS-dependent activation of the Fas/FasL-ASK1-p38 axis.

      • Seismic response evaluation of fixed jacket-type offshore structures by random vibration analysis

        Shehata E. Abdel Raheem,Elsayed M. Abdel Aal,Aly G.A. AbdelShafy,Mohamed F.M. Fahmy 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.42 No.2

        Offshore platforms in seismically active areas must be designed to survive in the face of intense earthquakes without a global structural collapse. This paper scrutinizes the seismic performance of a newly designed and established jacket type offshore platform situated in the entrance of the Gulf of Suez region based on the API-RP2A normalized response spectra during seismic events. A nonlinear finite element model of a typical jacket type offshore platform is constructed taking into consideration the effect of structure-soil-interaction. Soil properties at the site were manipulated to generate the pile lateral soil properties in the form of load deflection curves, based on API-RP2A recommendations. Dynamic characteristics of the offshore platform, the response function, output power spectral density and transfer functions for different elements of the platform are discussed. The joints deflection and acceleration responses demands are presented. It is generally concluded that consideration of the interaction between structure, piles and soil leads to higher deflections and less stresses in platform elements due to soil elasticity, nonlinearity, and damping and leads to a more realistic platform design. The earthquake-based analysis for offshore platform structure is essential for the safe design and operation of offshore platforms.

      • KCI등재

        Study of Thin Double-Gap RPCs for the CMS Muon System

        K. S. Lee,S. W. Cho,S. Choi,B. Hong,M. Kang,J. H. Lim,Y. M. Jo,S. K. Park,K. R. Ryoo,R. Aly,S. Aly,Y. Assran,A. Mohamed,A. Mahrous,S. Constantini,M. Abbrescia,A. Gelmi,M. Maggi,G. Iaselli,G. Pugliese 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.73 No.8

        High-sensitivity double-gap phenolic resistive plate chambers (RPCs) are studied for the Phase-2 upgrade of the Compact Muon Solenoid (CMS) muon system at high pseudorapidity . Whereas the present CMS RPCs have a gas gap thickness of 2 mm, we propose to use thinner gas gaps, which will improve the performance of these RPCs. To validate this proposal, we constructed double-gap RPCs with two different gap thicknesses of 1.2 and 1.4 mm by using high-pressure laminated plates having a mean resistivity of about 5 1010 -cm. This paper presents test results using cosmic muons and 137Cs gamma rays. The rate capabilities of these thin-gap RPCs measured with the gamma source exceed the maximum rate expected in the new high- endcap RPCs planned for future Phase-2 runs of the Large Hadron Collider (LHC).

      • SCOPUSKCI등재

        Physical Properties of Some Acetylbenzaldehydehydrazone Metal Complexes

        Abd El Wahed, M. G.,Bayoumi, H. A.,Mohammed, M. I. Korean Chemical Society 2003 Bulletin of the Korean Chemical Society Vol.24 No.9

        A series of complexes of bivalent transition metal ions with acetyl benzal dehydehydrazone and its derivatives of general formula ML have been prepared and characterized with the help of conductometric, photometric and infrared studies. The stability constants and related thermodynamic functions of complexes were determined using the potentiometric technique at different temperatures. The formation of complexes is exothermic process with covalency nature. The electrical conductivity of some solid complexes was measured in the temperature range 289-353 K. The results revealed semiconducting properties for the studied complexes.

      • KCI등재

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