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Mechanical behavior of Cu-Zr bulk metallic glasses (BMGs): A molecular dynamics approach

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Chinese Physics B 2013年第9期22卷 490-495页

作者： Muhammad Imran Fayyaz Hussain Muhammad Rashid Yongqing Cai s.A.ahmad Department of Physics simulation Lab The Islamia University of Bahawalpur Department of Physics National University of Singapore2 Science Drive 3117542Singapore

In the present work, three-dimensional molecular dynamics simulation is carried out to elucidate the nanoinden- tation behaviors of CuZr Bulk metallic glasses （BMGs）. The substrate indenter system is modeled using hybrid interatomic potentials including both many-body Finnis sinclair （Fs） and two-body Morse potentials. A spherical rigid indenter （diameter= 60 A（1 A = 10 ^-10 m）） is employed to simulate the indentation process. Three samples of BMGs including Cu25Zr75, CusoZr50, and Cu75Zr25 are designed and the metallic glasses are formed by rapid cooling from the melt state at about 2000 K. The radial distribution functions are analyzed to reveal the dynamical evolution of the structure of the atoms with different compositions and different cooling rates. The mechanical behavior can be well understood in terms of load-depth curves and Hardness-depth curves during the nanoindentation process. Our results indicate a positive linear relationship between the hardness and the Cu concentration of the BMG sample. To reveal the importance of cooling rate provided during the processing of BMGs, we investigate the indentation behaviors of CusoZr50 at three different quenching rates. Nanoindentation results and radial distribution function （RDF） curves at room temperature indicate that a sample can be made harder and more stable by slowing down the quenching rate.

关键词： Bulk metallic glasses (BMGs) nanoindentation deformation quenching rate

Generalized Multiresolution structures in Reducing subspaces of Local Fields

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Acta Mathematica sinica,English series 2022年第12期38卷 2163-2186页

作者： Owais ahmad Neyaz ahmad sHEIKH Department of Mathematics National Institute of TechnologySrinagar 190006India

In this article,we introduce the notion of general multiresolution structure(GMs)in the reducing subspace over local *** show that the GMs is admitted by an arbitrary reducing subspace and characterize all those GMss which admit a pyramids *** the culmination,we obtain a frame-like expansion for signals in reducing subspaces in terms of GMs over local fields.

关键词： Frame frame like expansion reducing subspace generalized multiresolution structure local field Fourier transform

Effects of thermophoresis and thermal radiation in mixed convection three-dimensional flow of Jeffrey fluid

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Applied Mathematics and Mechanics(English Edition) 2015年第5期36卷 655-668页

作者： s.A.sHEHZAD T.HAYAT A.ALsAEDI B.ahmad Department of Mathematics Comsats Institute of Information Technology Department of Mathematics Quaid-i-Azam University Department of Mathematics Faculty of Science King Abdulaziz University

Mixed convection three-dimensional flow of Jeffrey fluid is studied in the presence of thermal radiation and thermophoresis. The relevant problems are formulated,and series solutions are presented for velocities, temperature, and concentration. Convergence of series solutions is obtained graphically and numerically. Effects of different emerging parameters on the velocities, temperature, and concentration fields are plotted and discussed.

关键词： convection formulated Jeffrey Prandtl convergent admissible illustrate relaxation stretching numerically

Effect of srCO_3 addition on the dynamic compressive strength of ZTA

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International Journal of Minerals,Metallurgy and Materials 2016年第4期23卷 481-489页

作者： Ali Arab Roslan ahmad Zainal Arifin ahmad school of Mechanical Engineering Universiti Sains Malaysia Engineering Campus structural Materials Niche Area School of Materials and Mineral Resources Engineering Universiti Sains Malaysia Engineering Campus

Ceramic parts usually experience dynamic load in armor applications. Therefore, studying the dynamic behaviors of ceramics is important. Limited data are available on the dynamic behaviors of ceramics; thus, it is helpful to predict the dynamic strength of ceramics on the basis of their mechanical properties. In this paper, the addition of srCO3 into zirconia-toughened alumina（ZTA） was demonstrated to improve the fracture toughness of ZTA due to the formation of the srAl12O19（sA6） phase. The porosity of ZTA was found to be increased by the addition of srCO3. These newly formed pores served as the nucleation sites of cracks under dynamic load; these cracks eventually coalesced to form damaged zones in the samples. Although the KIC values of the samples were improved, the dynamic strength was not enhanced because of the increase in porosity; in fact, the dynamic strength of ZTA ceramics decreased with the addition of srCO3.

关键词： ceramics strontium carbonate dynamic properties fracture toughness compressive strength

Pterostilbene induces cell apoptosis and inhibits lipogenesis in sKOV3 ovarian cancer cells by activation of AMPK-induced inhibition of Akt/mTOR signaling cascade

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BIOCelL 2021年第1期45卷 89-101页

作者： ATTALLA el-KOTT EMAN elBEALY FAHMY elsAID HAITHAM el-MEKKAWY ABD-el-KARIM ABD-LATEIF ABDULALI TAWEel HEBA KHALIFA ahmad KANDEel KAREEM MORsY EssAM IBRAHIM MAsHAel MOHAMMED BIN-MEFERIJ Biology Department College of ScienceKing Khalid UniversityAbha61413Saudi Arabia Zoology Department College of ScienceDamanhour UniversityDamanhour22511Egypt Biology Department College of Science for GirlsKing Khalid UniversityAbha61413Saudi Arabia Zoology Department College of ScienceMansoura UniversityMansoura35511Egypt Zoology Department College of ScienceFayoum UniversityFayoum63511Egypt Zoology Department Faculty of ScienceAl-Zawia UniversityAl-ZawiaLibya Biology Department Faculty of ScienceCairo UniversityCairo12611Egypt Research Center for Advanced Materials science(RCAMs) King Khalid UniversityAbha61413Saudi Arabia Blood Products Quality Control and Research Department National Organization for Research and Control of BiologicalsCairo12611Egypt Biology Department College of SciencePrincess Nourah bint Abdulrahman UniversityRiyadhSaudi Arabia

This study investigates if the anti-tumor effect of Pterostilbene in the sKOV3 ovarian cancer(OC)cell line involves inhibition of cell metabolism and tested in this effect involves modulating AMPK and Akt-induced regulation of ***,sKOV3 cells were cultured in the humidified conditions in DMEM media for 24 h with or without increasing concentration of ***,the cells were incubated with Pterostilbene(IC_(50)=50μM)under similar conditions with or without pre-incubation with Dorsomorphin,an AMPK *** a dose-dependent manner,Pterostilbene inhibited sKOV3 cell survival and increased their lysate levels of lactate dehydrogenase(LDH)and single-stranded DNA(ssDNA).When sKOV3 cells were treated with 50μM Pterostilbene,Pterostilbene significantly suppressed cell migration and invasion,reduced lysate levels of lactic acid and the optical density of Oil Red O staining,and increased lysate glucose *** also increased levels of malondialdehyde(MDA),reactive oxygen species(ROs),and induced intrinsic cell apoptosis by upregulating protein levels of Bax and cleaved caspase-3 and reducing protein levels of ***,Pterostilbene reduced mRNA levels of sterol regulatory element-binding protein 1(sREBP-1),fatty acid synthase(FAs),acetyl CoA carboxylase-1(ACC-1),and AMP-activated protein kinase(AMPK).Furthermore,Pterostilbene increased the protein levels of p-AMPK,p-p53,p-raptor,p-TsC-2,but significantly decreased protein levels of p-Akt,p-TsC-2,p-mTOR,p-s6K1,and *** with Dorsomorphin(CC)abolished all the anti-tumorigenesis effects afforded by Pterostilbene and prevented Pterostilbene-induced phosphorylation of Akt,p53,and *** conclusion,the tumorsuppressive effect of Pterostilbene in sKOV3 cells involves the induction of ROs and inhibition of dysregulation cell metabolism mainly due to AMPK-induced Akt-dependent or independent suppression of mTOR.

关键词： Pterostilbene Ovarian cancer Lipogenesis Apoptosis AMPK

Activation of cerebral Ras-related C3 botulinum toxin substrate(Rac) 1 promotes post-ischemic stroke functional recovery in aged mice

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Neural Regeneration Research 2024年第4期19卷 881-886页

作者： Fan Bu Jia-Wei Min Md Abdur Razzaque ahmad el Hamamy Anthony Patrizz Li Qi Akihiko Urayama Jun Li Department of Neurology University of Texas Health Science Center Department of Neurology&Psychology The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine

Brain functional impairment after stroke is common;however,the molecular mechanisms of post-stroke recovery remain *** is well-recognized that age is the most important independent predictor of poor outcomes after stroke as older patients show poorer functional outcomes following *** evidence suggests that axonal regeneration and angiogenesis,the major forms of brain plasticity responsible for post-stroke recovery,diminished with advanced *** studies suggest that Ras-related C3 botulinum toxin substrate(Rac)1 enhances stroke recovery as activation of Rac1 improved behavior recovery in a young mice stroke ***,we investigated the role of Rac1 signaling in long-term functional recovery and brain plasticity in an aged(male,18 to 22 months old C57BL/6J)brain after ischemic *** found that as mice aged,Rac1 expression declined in the *** overexpression of Rac1,using lentivirus encoding Rac1 injected day 1 after ischemic stroke,promoted cognitive(assessed using novel object recognition test)and sensorimotor(assessed using adhesive removal tests)recovery on days 14–*** was accompanied by the increase of neurite and proliferative endothelial cells in the periinfarct zone assessed by *** a reverse approach,pharmacological inhibition of Rac1 by intraperitoneal injection of Rac1 inhibitor NsC23766 for 14 successive days after ischemic stroke worsened the outcome with the reduction of neurite and proliferative endothelial ***,Rac1 inhibition reduced the activation of p21-activated kinase 1,the protein level of brain-derived neurotrophic factor,and increased the protein level of glial fibrillary acidic protein in the ischemic brain on day 28 after *** work provided insight into the mechanisms behind the diminished plasticity after cerebral ischemia in aged brains and identified Rac1 as a potential therapeutic target for improving functional recovery in the older adults after stroke.

关键词： aging angiogenesis brain-derived neurotrophic factor(BDNF) cerebral ischemia cognitive recovery neurite Pak1 Rac1 sensorimotor recovery

Energetic, economic, and environmental analysis of solid oxide fuel cell-based combined cooling, heating, and power system for cancer care hospital

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Building simulation 2022年第8期15卷 1437-1454页

作者： ahmad K.sleiti Wahib AAl-Ammari Raiha Arshad Tarek EI Mekkawy Department of Mechanical&Industrial Engineering College of EngineeringQatar UniversityDohaQatar

In this study,energetic,economic,and environmental analysis of solid oxide fuel cell-based combined cooling,heating,and power(sOFC-CCHP)system is proposed for a cancer care hospital *** energy required for the hospital power,cooling,and heating demands was obtained based on real and detailed field data,which could serve as a reference for future works in the *** data with a 3D model for the hospital building are constructed and created in eQUEsT software to precisely calculate the energy demands of the existing system(baseline case).Then,energetic,economic,and environmental models were developed to compare and assess the performance of the proposed sOFC-CCHP *** results show that the proposed system can cover about 49% to 77% of the power demand of the hospital with an overall efficiency of 78.3%.Also,the results show that the levelized cost of electricity of the system and its payback period at the designed capacity of the sOFC is 0.087s/kWh and 10 years,***,compared to the baseline system of the hospital,the sOFC-CCHP reduces the CO_(2) emission by 89% over the *** sensitivity analysis showed that a maximum sOFC efficiency of 52%and overall efficiency of 80%are achieved at cell operating temperature of 1027℃ and fuel utilization factor of 0.85.

关键词： combined cooling,heating,and power solid oxide fuel cell hospital power demand CO_(2)emissions levelized cost of electricity(LCOE)

Quantum state Tomography and Quantum Games

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Chinese Physics Letters 2012年第3期29卷 37-40页

作者： ahmad Nawaz National Centre for Physics Quaid-i-Azam University CampusIslamabadPakistan

A technique is developed for single qubit quantum state tomography using the mathematical setup of generalized quantization scheme for *** this technique,Alice sends an unknown pure quantum state to Bob who appends it with|0>s the unitary operators on the appended quantum state and finds the payoffs for Alice and *** is shown that for a particular set of unitary operators,these payoffs are equal to stokes parameters for an unknown quantum *** this way an unknown quantum state can be measured and *** speaking,this technique is not a game as no strategic competitions are involved.

关键词： state quantum operators

sOX9 in biliary atresia: New insight for fibrosis progression

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Hepatobiliary & Pancreatic Diseases International 2021年第2期20卷 154-162页

作者： Hanaa Ahmed el-Araby Magdy Anwar saber Noha Mohamed Radwan Doha Maher Taie Nermin Mohamed Adawy ahmad Mohamed sira Department of Pediatric Hepatology Gastroenterologyand NutritionNational Liver InstituteMenoufia University32511 Shebin El-koomMenoufiaEgypt Department of Pathology National Liver InstituteMenoufia University32511 Shebin El-koomMenoufiaEgypt

Background:Liver fibrosis is a hallmark determinant of morbidity in biliary atresia(BA)even in successfully operated *** factors for this rapid progression of fibrosis are not completely *** expression of the transcription factor sOX9 and hepatic progenitor cells(HPCs)proliferation have roles in fibrogenesis in cholestatic ***,they were not investigated sufficiently in *** aimed to delineate the relation of sOX9 and HPCs to fibrosis and its progression in ***:Forty-eight patients with BA who underwent an initial diagnostic liver biopsy(LB)and consequent intraoperative LB were recruited and compared to 28 cases with non-BA cholestasis that had an LB in their diagnostic *** fibrosis,tissue sOX9 and HPC expressions were studied in both BA and non-BA-cholestasis *** fibrosis,sOX9,and HPCs’dynamic changes in BA cases were *** of fibrosis and its progression to sOX9 and HPCs in BA was ***:sOX9 and HPCs in ductular reaction(DR)form were expressed in 100%of BA and their grades increased significantly in the second *** rapidly progressive fibrosis in BA,represented by fibrosis grade of the intraoperative LB,correlated significantly to sOX9-DR and HPC-DR at the diagnostic(r=0.420,P=0.003 and r=0.405,P=0.004,respectively)and the intraoperative(r=0.460,P=0.001 and r=0.467,P=0.001,respectively)*** the other hand,fibrosis,sOX9-DR,and HPC-DR were significantly lower in non-BA cases at a comparable age(Pspectively).Conclusions:Fibrosis in BA is rapidly progressive within a short time and is significantly correlated to sOX9 and *** of targeting sOX9 and HPCs on fibrosis progression is warranted.

关键词： Biliary atresia Fibrosis Hepatic progenitor cells Immunohistochemistry Neonatal cholestasis sOX9