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>

Nine months versus 12 months of adjuvant trastuzumab for patients with HER2-positive breast cancer

Ashraf Mahmoud El-Enbaby,Nadia Ahmed Abd El Moneim,Gehan Abd El atti Khedr,Yasmine Mohamed Nagy Elwany 대한종양외과학회 2018 Korean Journal of Clinical Oncology Vol.14 No.2

Purpose: This study aimed to compare the results of treatment with adjuvant trastuzumab for 9 months versus 12 months in human epider�mal growth factor 2 (HER2)-positive breast cancer patients. The primary endpoint was disease-free survival. Secondary endpoints included cardiac safety, tolerability, and overall survival. Methods: The study included 60 non-metastatic HER2-positive breast cancer patients. All study patients underwent surgery, received adju�vant chemotherapy, radiotherapy and hormonal therapy if indicated. Thirty patients were randomized in each group. Group I patients received adjuvant trastuzumab for 12 months, while group II patients received adjuvant trastuzumab for 9 months. Patients were assessed by clinical examination and Echocardiography during treatment. Results: After median follow-up of 12 months, 90% of the patients in group I were disease free and 83.3% of patients in group II were dis�ease free (P=0.402). All studied population in both groups I and II were alive at the end of the 1-year follow-up period after the completion of adjuvant trastuzumab treatment thus overall survival is 100%. Conclusion: Trastuzumab is tolerable and its side effects are reversible. Nine months of adjuvant trastuzumab treatment is more cost effec�tive than the standard 12 months.

Analysis of composite frame structures with mixed elements – state of the art

Ashraf Ayoub 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.2

The paper presents a review of the application of the newly proposed mixed finite element model for seismic simulation of different types of composite frame structures. To evaluate the performance of the element, a comparison with displacement-based and force-based models is conducted. The study revealed that the mixed model is superior to the others in terms of both speed of convergence and numerical stability, and is therefore considered the most practical approach for modeling of composite structures. In this model, the element is derived using independent force and displacement shape functions. The nonlinear response of the frame element is based on the section discretization into fibers with uniaxial material models. The interfacial behavior is modeled using an inelastic interface element. Numerical examples to clarify the advantages of the model are presented for the following structural applications: anchored reinforcing bar problems, composite steel-concrete girders with deformable shear connectors, beam on elastic foundation elements, R/C girders strengthened with FRP sheets, R/C beam-columns with bond-slip, and prestressed concrete girders. These studies confirmed that the model represents a major advancement over existing elements in simulating the inelastic behavior of composite structures.

The effect of two temperatures on a FG nanobeam induced by a sinusoidal pulse heating

Ashraf M. Zenkour,Ahmed E. Abouelregal 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.51 No.2

The present investigation is concerned with the effect of two temperatures on functionally graded (FG) nanobeams subjected to sinusoidal pulse heating sources. Material properties of the nanobeam are assumed to be graded in the thickness direction according to a novel exponential distribution law in terms of the volume fractions of the metal and ceramic constituents. The upper surface of the FG nanobeam is fully ceramic whereas the lower surface is fully metal. The generalized two-temperature nonlocal theoryof thermoelasticity in the context of Lord and Shulman's (LS) model is used to solve this problem. The governing equations are solved in the Laplace transformation domain. The inversion of the Laplace transformation is computed numerically using a method based on Fourier series expansion technique. Somecomparisons have been shown to estimate the effects of the nonlocal parameter, the temperature discrepancy and the pulse width of the sinusoidal pulse. Additional results across the thickness of the nanobeam are presented graphically.

Thermoelastic interaction in functionally graded nanobeams subjected to time-dependent heat flux

Ashraf M. Zenkour,Ahmed E. Abouelregal 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.18 No.4

This paper investigates the vibration phenomenon of a nanobeam subjected to a time-dependent heat flux. Material properties of the nanobeam are assumed to be graded in the thickness direction according to a novel exponential distribution law in terms of the volume fractions of the metal and ceramic constituents. The upper surface of the functionally graded (FG) nanobeam is pure ceramic whereas the lower surface is pure metal. A nonlocal generalized thermoelasticity theory with dual-phase-lag (DPL) model is used to solve this problem. The theories of coupled thermoelasticity, generalized thermoelasticity with one relaxation time, and without energy dissipation can extracted as limited and special cases of the present model. An analytical technique based on Laplace transform is used to calculate the variation of deflection and temperature. The inverse of Laplace transforms are computed numerically using Fourier expansion techniques. The effects of the phase-lags (PLs), nonlocal parameter and the angular frequency of oscillation of the heat flux on the lateral vibration, the temperature, and the axial displacement of the nanobeam are studied.

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.

DNA Glycation from 3-Deoxyglucosone Leads to the Formation of AGEs: Potential Role in Cancer Auto-antibodies

Ashraf, J. M.,Shahab, U.,Tabrez, S.,Lee, E. J.,Choi, I.,Aslam Yusuf, M.,Ahmad, S. HUMANA PRESS INC 2016 CELL BIOCHEMISTRY AND BIOPHYSICS Vol.74 No.1

<P>The non-enzymatic glycation reaction results in the generation of free radicals which play an important role in the pathophysiology of aging, diabetes, and cancer. 3-Deoxyglucosone (3-DG) is a dicarbonyl species which may lead to the formation of advanced glycation end products (AGEs). 3-DG also reacts with free amino group of nucleic acids resulting in the formation of DNA-AGEs. While the establishment of nucleoside AGEs has been revealed before, no extensive studies have been done to probe the role of 3-DG in the generation of immunogenicity and induction of cancer auto-antibodies. In this study, we report the immunogenicity of AGEs formed by 3-DG-Arg-Fe3+ system. Spectroscopic analysis and melting temperature studies suggest structural perturbations in the DNA as a result of modification. Immunogenicity of native and 3-DG-Arg-Fe3+ DNA was probed in female rabbits. The modified DNA was highly immunogenic eliciting high-titer immunogen-specific antibodies, while the unmodified form was almost non-immunogenic. We also report the presence of auto-antibodies against 3-DG-Arg-Fe3+-modified DNA in the sera of patients with different types of cancers. The glycoxidative lesions were also detected in the lymphocyte DNA isolated from selected cancer patients. The results show structural perturbations in 3-DG-Arg-Fe3+-DNA generating new epitopes that render the molecule immunogenic.</P>

Precise Detection and Elimination of Grid Injected DC from Single Phase Inverters

Ashraf Abdel hafeez Ahmed Mahm,Ran Li 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

Single-phase voltage source inverters are used for connecting small scale renewable energy sources to low voltage distribution networks. They operate to supply the network with sinusoidal current. If output transformers are not used, these inverters must prevent excessive dc current injection, which may cause detrimental effects in the network. In this study, the causes of dc current injection in a common inverter topology are analyzed. This work explains the design and test of a passive filter circuit precisely measuring the dc component in the inverter output current. The filtered dc signal is then used to control the single phase inverter for the objective to keep the dc injection low – below the standard limit. Characteristics of the proposed method are illustrated using simulation and experimental results.

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.

Video Inpainting for Object Removal

Ashraf Siddique,Seungkyu Lee 한국정보과학회 2016 한국정보과학회 학술발표논문집 Vol.2016 No.12