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      • KCI등재

        Investigating the Effects of Resveratrol on Chronically Ischemic Myocardium in a Swine Model of Metabolic Syndrome: A Proteomics Analysis

        Ashraf A. Sabe,Ahmed A. Sadek,Nassrene Y. Elmadhun,Rahul S. Dalal,Michael P. Robich,Cesario Bianchi,Frank W. Sellke 한국식품영양과학회 2015 Journal of medicinal food Vol.18 No.1

        Resveratrol has been shown to improve cardiac perfusion and ventricular function after chronic ischemic injury. Using proteomic analysis, we sought to objectively investigate potential mechanisms, by which resveratrol exerts its cardioprotective effects in the setting of metabolic syndrome and chronic myocardial ischemia. Yorkshire swine were divided into two groups based on diet: high cholesterol (n = 7) or a high-cholesterol diet with supplemental resveratrol (n = 6). Four weeks later, all animals underwent surgical placement of an ameroid constrictor to their left circumflex artery. Diets were continued for another 7 weeks, and then the ischemic myocardium was harvested for proteomics analysis. Proteomic analysis identified 669 common proteins between the two groups. Of these proteins, 76 were statistically different, of which 41 were characterized (P < .05). Pathway analysis demonstrated that in animals supplemented with resveratrol, there was a downregulation in several proteins involved with mitochondrial dysfunction, cell death, and unfavorable cardiac remodeling. Furthermore, there was an upregulation in proteins involved in free radical elimination. We conclude that resveratrol supplementation significantly alters several critical protein markers in the chronically ischemic myocardium. Further investigation of these proteins may help elucidate the mechanisms by which resveratrol exerts its cardioprotective effects.

      • KCI등재

        FPGA-based Centralized Controller for Multiple PV Generators Tied to the DC Bus

        Ashraf Ahmed,Pradeep Ganeshkumar,Joung-Hu Park,Hojin Lee 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.4

        The integration of photovoltaic (PV) energy sources into DC grid has gained considerable attention because of its enhanced conversion efficiency with reduced number of power conversion stages. During the integration process, a local control unit is normally included with every power conversion stage of the PV source to accomplish the process of maximum power point tracking. A centralized monitoring and supervisory control unit is required for monitoring, power management, and protection of the entire system. Therefore, we propose a field-programmable gate array (FPGA) based centralized control unit that integrates all local controllers with the centralized monitoring unit. The main focus of this study is on the process of integrating many local control units into a single central unit. In this paper, we present design and optimization procedures for the hardware implementation of FPGA architecture. Furthermore, we propose a transient analysis and control design methodology with consideration of the nonlinear characteristics of the PV source. Hardware experiment results verify the efficiency of the central control unit and controller design.

      • Flurbiprofen–antioxidant mutual prodrugs as safer nonsteroidal anti-inflammatory drugs: synthesis, pharmacological investigation, and computational molecular modeling

        Ashraf, Zaman,Alamgeer,Kanwal, Munazza,Hassan, Mubashir,Abdullah, Sahar,Waheed, Mamuna,Ahsan, Haseeb,Kim, Song Ja Dove Medical Press 2016 Drug design, development and therapy Vol.10 No.-

        <P>Flurbiprofen–antioxidant mutual prodrugs were synthesized to reduce the gastrointestinal (GI) effects associated with flurbiprofen. For reducing the GI toxicity, the free carboxylic group (–COOH) was temporarily masked by esterification with phenolic –OH of natural antioxidants vanillin, thymol, umbelliferone, and sesamol. The in vitro hydrolysis of synthesized prodrugs showed that they were stable in buffer solution at pH 1.2, indicating their stability in the stomach. The synthesized prodrugs undergo significant hydrolysis in 80% human plasma and thus release free flurbiprofen. The minimum reversion was observed at pH 1.2, suggesting that prodrugs are less irritating to the stomach than flurbiprofen. The anti-inflammatory, analgesic, antipyretic, and ulcerogenic activities of prodrugs were evaluated. All the synthesized prodrugs significantly (<I>P</I><0.001) reduced the inflammation against carrageenan and egg albumin-induced paw edema at 4 hours of study. The reduction in the size of the inflamed paw showed that most of the compounds inhibited the later phase of inflammation. The prodrug 2-oxo-2<I>H</I>-chromen-7-yl-2-(2-fluorobiphenyl-4-yl)propanoate (<B>4b</B>) showed significant reduction in paw licking with percentage inhibition of 58%. It also exhibited higher analgesic activity, reducing the number of writhes with a percentage of 75%, whereas flurbiprofen showed 69% inhibition. Antipyretic activity was investigated using brewer’s yeast-induced pyrexia model, and significant (<I>P</I><0.001) reduction in rectal temperature was shown by all prodrugs at all times of assessment. The results of ulcerogenic activity showed that all prodrugs produced less GI irritation than flurbiprofen. Molecular docking and simulation studies were carried out with cyclooxygenase (COX-1 and COX-2) proteins, and it was observed that our prodrugs have more potential to selectively bind to COX-2 than to COX-1. It is concluded that the synthesized prodrugs have promising pharmacological activities with reduced GI adverse effects than the parent drug.</P>

      • Synthesis, Bioevaluation and Molecular Dynamic Simulation Studies of Dexibuprofen–Antioxidant Mutual Prodrugs

        Ashraf, Zaman,Alamgeer,,Rasool, Raqiqatur,Hassan, Mubashir,Ahsan, Haseeb,Afzal, Samina,Afzal, Khurram,Cho, Hongsik,Kim, Song Ja,Zhang, Ge,Lu, Aiping MDPI 2016 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.17 No.12

        <P>Dexibuprofen–antioxidant conjugates were synthesized with the aim to reduce its gastrointestinal effects. The esters analogs of dexibuprofen <B>5a</B>–<B>c</B> were obtained by reacting its –COOH group with chloroacetyl derivatives <B>3a</B>–<B>c</B>. The in vitro hydrolysis data confirmed that synthesized prodrugs <B>5a</B>–<B>c</B> were stable in stomach while undergo significant hydrolysis in 80% human plasma and thus release free dexibuprofen. The minimum reversion was observed at pH 1.2 suggesting that prodrugs are less irritating to stomach than dexibuprofen. The anti-inflammatory activity of <B>5c</B> (<I>p</I> < 0.001) is more significant than the parent dexibuprofen. The prodrug <B>5c</B> produced maximum inhibition (42.06%) of paw-edema against egg-albumin induced inflammation in mice. Anti-pyretic effects in mice indicated that prodrugs <B>5a</B> and <B>5b</B> showed significant inhibition of pyrexia (<I>p</I> < 0.001). The analgesic activity of <B>5a</B> is more pronounced compared to other synthesized prodrugs. The mean percent inhibition indicated that the prodrug <B>5a</B> was more active in decreasing the number of writhes induced by acetic acid than standard dexibuprofen. The ulcerogenic activity results assured that synthesized prodrugs produce less gastrointestinal adverse effects than dexibuprofen. The ex vivo antiplatelet aggregation activity results also confirmed that synthesized prodrugs are less irritant to gastrointestinal mucosa than the parent dexibuprofen. Molecular docking analysis showed that the prodrugs <B>5a</B>–<B>c</B> interacts with the residues present in active binding sites of target protein. The stability of drug–target complexes is verified by molecular dynamic simulation study. It exhibited that synthesized prodrugs formed stable complexes with the COX-2 protein thus support our wet lab results. It is therefore concluded that the synthesized prodrugs have promising pharmacological activities with reduced gastrointestinal adverse effects than the parent drug.</P>

      • KCI등재

        COOPERATIVE CRUISE CONTROLLER FOR HOMOGENEOUS AND HETEROGENEOUS VEHICLE PLATOON SYSTEM

        Ashraf Saleem,Ahmed Al Maashri,Muna A. Al-Rahbi,Medhat Awadallah,Hadj Bourdoucen 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.6

        Autonomous cars have become a reality due to breakthroughs in technology enablers such as embedded computing systems and artificial intelligence. Automated platooning, which can be employed in autonomous cars, allows grouping of vehicles into platoons. Using this technology in highways brings forth a number of benefits such as improving traffic throughput, increasing fuel efficiency, and reducing collisions. Towards that end, this paper proposes a cooperative cruise controller for both homogeneous and heterogeneous vehicle platoon systems. The controller consists of two control layers; namely, platoon supervisory control layer and cruise control layer. The developed controller was validated and evaluated through an intensive set of simulation scenarios. The results show that the controller outperforms other contenders by 40 % in improving the road capacity. In addition, the results indicate that the controller is capable of handling different traffic scenarios (i.e. homogeneous vs. heterogeneous vehicle platoons) as well as being fault-tolerant to disruptions such as loss of communication between vehicles.

      • KCI등재

        Power Management of Open Winding PM Synchronous Generator for Unbalanced Voltage Conditions

        Ashraf EL- Bardawil,Mona Fouad Moussa 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

        Wind energy is currently the fastest-growing electricity source worldwide. The cost efficiency of wind generators must be high because these generators have to compete with other energy sources. In this paper, a system that utilizes an open-winding permanent-magnet synchronous generator is studied for wind-energy generation. The proposed system controls generated power through an auxiliary voltage source inverter. The VA rating of the auxiliary inverter is only a fraction of the system-rated power. An adjusted control system, which consists of two main parts, is implemented to control the generator power and the grid-side converter. This paper introduces a study on the effect of unbalanced voltages for the wind-generation system. The proposed system is designed and simulated using MATLAB/Simulink software. Theoretical and experimental results verify the validity of the proposed system to achieve the power management requirements for balanced and unbalanced voltage conditions of the grid.

      • Energy Efficient Online Power Allocation for Two Users With Energy Harvesting

        Ashraf, Mateen,Jung, Jaehoon,Shin, Hun Min,Lee, Inkyu IEEE 2019 IEEE signal processing letters Vol.26 No.1

        <P>In this letter, we propose an online power allocation (PA) method to maximize energy efficiency (EE) in energy harvesting systems with realistic battery constraints for two receivers. The optimization problem in this system configuration is challenging since it has a non-convex fractional form and the information of channel quality and the harvested energy can only be obtained causally in practice. To overcome these issues, we design time-average EE maximization through Lyapunov optimization techniques where the transmission power is computed with current battery information and channel fading. Moreover, based on random matrix theory, we present a simplified online EE algorithm. Numerical experiments verify that the proposed PA outperforms conventional online approaches with much reduced computational complexity.</P>

      • SCOPUSKCI등재

        An Ideal-based Extended Zero-divisor Graph on Rings

        Ashraf, Mohammad,Kumar, Mohit Department of Mathematics 2022 Kyungpook mathematical journal Vol.62 No.3

        Let R be a commutative ring with identity and let I be a proper ideal of R. In this paper, we study the ideal based extended zero-divisor graph 𝚪'<sub>I</sub> (R) and prove that 𝚪'<sub>I</sub> (R) is connected with diameter at most two and if 𝚪'<sub>I</sub> (R) contains a cycle, then girth is at most four girth at most four. Furthermore, we study affinity the connection between the ideal based extended zero-divisor graph 𝚪'<sub>I</sub> (R) and the ideal-based zero-divisor graph 𝚪<sub>I</sub> (R) associated with the ideal I of R. Among the other things, for a radical ideal of a ring R, we show that the ideal-based extended zero-divisor graph 𝚪'<sub>I</sub> (R) is identical to the ideal-based zero-divisor graph 𝚪<sub>I</sub> (R) if and only if R has exactly two minimal prime-ideals which contain I.

      • KCI등재

        A New Soft-Fusion Approach for Multiple-Receiver Wireless Communication Systems

        Ashraf M. Aziz,Ahmed M. ElBakly,Mohamed H.A. Azeem,Gamal A. Hamid 한국전자통신연구원 2011 ETRI Journal Vol.33 No.3

        In this paper, a new soft-fusion approach for multiple-receiver wireless communication systems is proposed. In the proposed approach, each individual receiver provides the central receiver with a confidence level rather than a binary decision. The confidence levels associated with the local receiver are modeled by means of soft-membership functions. The proposed approach can be applied to wireless digital communication systems, such as amplitude shift keying, frequency shift keying, phase shift keying, multi-carrier code division multiple access, and multiple inputs multiple outputs sensor networks. The performance of the proposed approach is evaluated and compared to the performance of the optimal diversity, majority voting, optimal partial decision, and selection diversity in case of binary noncoherent frequency shift keying on a Rayleigh faded additive white Gaussian noise channel. It is shown that the proposed approach achieves considerable performance improvement over optimal partial decision, majority voting, and selection diversity. It is also shown that the proposed approach achieves a performance comparable to the optimal diversity scheme.

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