Physicochemical analysis of structural alteration and advanced glycation end products generation during glycation of H2A histone by 3-deoxyglucosone : GLYCATING POTENTIAL OF 3-DG WITH H2A HISTONE PROTEIN

Ashraf, Jalaluddin M.,Ahmad, Saheem,Rabbani, Gulam,Jan, Arif Tasleem,Lee, Eun Ju,Khan, Rizwan Hasan,Choi, Inho Wiley (John WileySons) 2014 IUBMB life Vol.66 No.10

<P>Advanced glycation end-products comprise a complex and heterogeneous group of compounds that have been implicated in diabetes-related complications. The importance of the Maillard reaction is depicted by the formation of reactive intermediate products known as α-oxoaldehydes, such as 3-deoxyglucosone (3-DG). This product has been found to be involved in accelerated vascular damage in diabetes. In the present study, calf thymus histone H2A was reacted with 3-DG, and the generation of advanced glycation end products was investigated by determining the degree of side chain modifications (lysine and arginine residues), Amadori products, carbonyl content, N(ε) -carboxymethyl lysine, and pentosidine using various physicochemical techniques. Moreover, fluorescence, absorbance as well as structural characteristics of glycated-H2A were comprehensively investigated. Overall, this study demonstrates structural perturbation, formation of different intermediates, and AGEs that are believed to hamper the normal functioning of H2A histone, compromising the integrity of chromatin structures and function in secondary complications of diabetes.</P>

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'_I (R) and prove that 𝚪'_I (R) is connected with diameter at most two and if 𝚪'_I (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'_I (R) and the ideal-based zero-divisor graph 𝚪_I (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'_I (R) is identical to the ideal-based zero-divisor graph 𝚪_I (R) if and only if R has exactly two minimal prime-ideals which contain I.

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>

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.

Prediction of Mortality in Nonagenarians Following the Surgical Repair of Hip Fractures

Ashraf Fansa,Scott Huff, BA,Nabil Ebraheim 대한정형외과학회 2016 Clinics in Orthopedic Surgery Vol.8 No.2

Background: The purpose of this study is to report on the mortality of nonagenarians who underwent surgical treatment for a hip fracture, specifically in regards to preexisting comorbidities. Furthermore, we assessed the effectiveness of the Deyo score in predicting such mortality. Methods: Thirty-nine patients over the age of 90 who underwent surgical repair of a hip fracture were retrospectively analyzed. Twenty-six patients (66.7%) suffered femoral neck fractures, while the remaining 13 (33.3%) presented with trochanteric type fractures. Patient charts were examined to determine previously diagnosed patient comorbidities as well as living arrangements and mobility before and after surgery. Results: Deyo index scores did not demonstrate statistically significant correlations with postoperative mortality or functional outcomes. The hazard of in-hospital mortality was found to be 91% (p = 0.036) and 86% (p = 0.05) less in patients without a history of congestive heart failure (CHF) and chronic pulmonary disease (CPD), respectively. Additionally, the hazard of 90-day mortality was 88% (p = 0.01) and 81% (p = 0.024) less in patients without a history of dementia and CPD, respectively. The hazard of 1-year mortality was also found to be 75% (p = 0.01) and 80% (p = 0.01) less in patients without a history of dementia and CPD, respectively. Furthermore, dementia patients stayed in-hospital postoperatively an average of 5.3 days (p = 0.013) less than nondementia patients and only 38.5% returned to preoperative living conditions (p = 0.036). Conclusions: Nonagenarians with a history of CHF and CPD have a higher risk of in-hospital mortality following the operative repair of hip fractures. CPD and dementia patients over 90 years old have higher 90-day and 1-year mortality hazards postoperatively. Dementia patients are also discharged more quickly than nondementia patients.

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>

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.

Regulation of senescence associated signaling mechanisms in chondrocytes for cartilage tissue regeneration

Ashraf, S.,Cha, B.H.,Kim, J.S.,Ahn, J.,Han, I.,Park, H.,Lee, S.H. Published for the Society by Baillère Tinda 2016 OSTEOARTHRITIS AND CARTILAGE Vol.24 No.2

<P>Adult articular chondrocytes undergo slow senescence and dedifferentiation during in vitro expansion, restricting successful cartilage regeneration. A complete understanding of the molecular signaling pathways involved in the senescence and dedifferentiation of chondrocytes is essential in order to better characterize chondrocytes for cartilage tissue engineering applications. During expansion, cell fate is determined by the change in expression of various genes in response to aspects of the microenvironment, including oxidative stress, mechanical stress, and unsuitable culture conditions. Rapid senescence or dedifferentiation not only results in the loss of the chondrocytic phenotype but also enhances production of inflammatory mediators and matrix-degrading enzymes. This review focuses on the two groups of genes that play direct and indirect roles in the induction of senescence and dedifferentiation. Numerous degenerative signaling pathways associated with these genes have been reported. Upregulation of the genes interleukin 1 beta (IL-1 beta), p53, p16, p21, and p38 mitogen-activated protein kinase (MAPK) is responsible for the direct induction of senescence, whereas downregulation of the genes transforming growth factor-beta (TGF-beta), bone morphogenetic protein-2 (BMP-2), SRY (sex determining region Y)-box 9 (SOX9), and insulin-like growth factor-1 (IGF-1), indirectly induces senescence. In senescent and dedifferentiated chondrocytes, it was found that TGF-beta, BMP-2, SOX9, and IGF-1 are downregulated, while the levels of IL-1 beta, p53, p16, p21, and p38 MAPK are upregulated followed by inhibition of the normal molecular functioning of the chondrocytes. This review helps to elucidate the underlying mechanism in degenerative cartilage disease, which may help to improve cartilage tissue regeneration techniques. (C) 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.</P>