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Journal of Diabetes Mellitus 2012年第1期2卷 82-87页

作者： Saad Abdulrahman Hussain Zheen Aorahman ahmed Taha Othman Mahwi tavga ahmed aziz Department of Pharmacology and Toxicology College of Pharmacy University of Baghdad Baghdad Iraq

Postprandial hyperglycemia is a major risk factor for diabetic complications leading to disabilities and mortality in diabetics. Quercetin, a flavonoid, has been tried in traditional medicine for treating diabetes. The present study was designed to evaluate the potential of quercetin to control postprandial blood glucose level after maltose and glucose loading in normal and STZ-induced diabetic rats. Normal male Albino wistar rats and STZ-induced diabetic rats were treated with 300 and 600 mg/kg quercetin orally to evaluate the effect on postprandial hyperglycemia after carbohydrate loading, using acarbose as comparator. The results clearly showed ameliorated postprandial hyperglycemia due to the use of quercetin (300 and 600 mg/kg), it significantly dampened the postprandial hyperglycemia by 32.0% and 64.0% respectively, in maltose loaded diabetic rats, and 30.3% after 300 mg/kg dose in normal rats, compared to control;while acarbose produced 51% and 54% decrease in this respect in the two models respecttively. Quercetin in 600 mg/kg dose produces significantly more reduction in postprandial hyperglycemia compared to acarbose, while in rats that received glucose and quercetin, postprandial hyperglycemia was not significantly affected. In conclusion, quercetin effectively suppresses postprandial hyperglycemia in STZ-induced diabetic rats loaded with maltose, which may be attributed to α-glucosidase inhibition. Quercetin could be used as a potential supplement for treating postprandial hyperglycemia.

关键词： Quercetin Postprandial Hyperglycemia Diabetes α-Glucosidase Rats

A toughness based deformation limit for X- and K-joints under brace axial tension

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Frontiers of Structural and Civil Engineering 2016年第3期10卷 345-362页

作者： Bo GU Xudong QIAN aziz ahmed Department of Civil and Environmental Engineering National University of Singapore 1 Engineering Drive 2 Singapore 117576 Singapore

This study reports a deformation limit for the initiation of ductile fracture failure in fatigue-cracked circular hollow section （CHS） X- and K-joints subjected to brace axial tension. The proposed approach sets the deformation limit as the numerically computed crack driving force in a fatigue crack at the hot-spot location in the tubular joint reaches the material fracture toughness measured from standard fracture specimens. The calibration of the numerical procedure predicates on reported numerical computations on the crack driving force and previously published verification study against large-scale CHS X-joints with fatigue generated surface cracks. The development of the deformation limit includes a normalization procedure, which covers a wide range of the geometric parameters and material toughness levels. The lower-bound deformation limits thus developed follow a linear relationship with respect to the crack-depth ratio for both X- and K-joints. Comparison of the predicated deformation limit against experimental on cracked tubular X- and K- joints demonstrates the conservative nature of the proposed deformation limit. The proposed deformation limit, when extrapolated to a zero crack depth, provides an estimate on the deformation limits for intact X- and K-joints under brace axial loads.

关键词： circular hollow section (CHS) tubular joint fracture failure deformation limit J-integral

Electromagnetic effects on the orbital motion of a charged spacecraft

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Research in Astronomy and Astrophysics 2014年第5期14卷 589-600页

作者： Yehia ahmed Abdel-aziz Khalil Ibrahim Khalil National Research Institute of Astronomy and Geophysics (NRIAG) Helwan Cairo 11721Egypt Department of Mathematics Hail University Hail 2440 Kingdom of Saudi Arabia

This paper deals with the effects of electromagnetic forces on the orbital motion of a spacecraft. The electrostatic charge which a spacecraft generates on its surface in the Earth＇s magnetic field will be subject to a perturbative Lorentz force. A model incorporating all Lorentz forces as a function of orbital elements has been developed on the basis of magnetic and electric fields. This Lorentz force can be used to modify or perturb the spacecraft＇s orbits. Lagrange＇s planetary equations in the Gauss variational form are derived using the Lorentz force as a perturbation to a Keplerian orbit. Our approach incorporates orbital inclination and the true anomaly. The numer- ical results of Lagrange＇s planetary equations for some operational satellites show that the perturbation in the orbital elements of the spacecraft is a second order perturba- tion for a certain value of charge. The effect of the Lorentz force due to its magnetic component is three times that of the Lorentz force due to its electric component. In addition, the numerical results confirm that the strong effects are due to the Lorentz force in a polar orbit, which is consistent with realistic physical phenomena that occur in polar orbits. The results confirm that the magnitude of the Lorentz force depends on the amount of charge. This means that we can use artificial charging to create a force to control the attitude and orbital motion of a spacecraft.

关键词： space vehicles -- atmospheric effects -- celestial mechanics -- kine-matics and dynamics

Darcy–Forchheimer Three-Dimensional Flow of Williamson Nanofluid over a Convectively Heated Nonlinear Stretching Surface

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Communications in Theoretical Physics 2017年第9期67卷 387-394页

作者： Tasawar Hayat Arsalan aziz Taseer Muhammad ahmed Alsaedi Department of Mathematics Quaid-I-Azam University Nonlinear Analysis and Applied Mathematics (NAAM) Research Group Department of Mathematics Faculty of ScienceKing Abdulaziz University

The present study elaborates three-dimensional flow of Williamson nanoliquid over a nonlinear stretchable surface. Fluid flow obeys Darcy–Forchheimer porous medium. A bidirectional nonlinear stretching surface generates the flow. Convective surface condition of heat transfer is taken into consideration. Further the zero nanoparticles mass flux condition is imposed at the boundary. Effects of thermophoresis and Brownian diffusion are considered. Assumption of boundary layer has been employed in the problem formulation. Convergent series solutions for the nonlinear governing system are established through the optimal homotopy analysis method(OHAM). Graphs have been sketched in order to analyze that how the velocity, temperature and concentration distributions are affected by distinct emerging flow parameters. Skin friction coefficients and local Nusselt number are also computed and discussed.

关键词： three-dimensional flow Williamson fluid nanoparticles Darcy-Forchheimer porous medium con-vective boundary condition nonlinear stretching surface

Study of the degradation behavior and the biocompatibility of Mg-0.8Ca alloy for orthopedic implant applications

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Journal of Magnesium and Alloys 2019年第2期7卷 249-257页

作者： Aya Mohamed ahmed MEl-aziz Hans-Georg Breitinger Materials Engineering Department German University in Cairo(GUC)11835 New CairoEgypt Department of Biochemistry German University in Cairo(GUC)11835 New CairoEgypt

Mg-Ca alloys have recently attracted great attention towards the research in the field of orthopedic biodegradable *** study presents an in vitro degradation assessment of Mg-0.8Ca(0.8 wt.%of Ca)alloy in Hank’s balanced salt solution(HBSS).Immersion,hydrogen evolution and electrochemical behavior was studied as well as the cytotoxicity of the degradation *** and phase composition of the corrosion products were studied using SEM,EDX and XRD *** in HBSS resulted in the formation of the needle-shaped carbonated hydroxyapatite which was similar to the biological apatite in the human *** kinetics showed that Mg-0.8Ca alloy had approximately 3-fold faster degradation rate than the pure Mg(1.08±0.38 mm/year for Mg-0.8Ca and 0.35±0.17 mm/year for pure Mg),as observed in two independent ***,pure Mg and Mg-0.8Ca alloy were biocompatible,generating no cytotoxic degradation products against human-derived HEK 293 ***,the Mg-0.8Ca alloy was found to be a promising biodegradable implant in terms of bioactivity and compatibility with human cell *** on the application of the implant and the estimated healing time of the bone,the desired degradation rate of an implant can be controlled by the Mg-Ca composition of such alloys.

关键词： Mg-Ca alloys Biodegradability Orthopedic implants Biocompatibility Toxicity Hydroxyapatite

Autumn larval fish assemblages in the northwest African Atlantic coastal zone

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Chinese Journal of Oceanology and Limnology 2017年第3期35卷 515-527页

作者： ABDELOUAHAB Hinde BERRAHO Amina BAIBAI Tarik AGOUZOUK aziz MAKAOUI ahmed ERRHIF ahmed Faculty of Sciences Ain Chock Hassan 1I UniversityB.P.5366MaarifCasablanca20100Morocco National Institute of Halieutic Research Street Sidi Abderrahmane Club equestre Ould JmelCasablanca20100Morocco

A study on the assemblage composition and vertical distribution of larval fish was conducted in the southern area of the Moroccan Atlantic coast in Autumn 2011. A total of I 680 fish larvae taxa were identified from 21 families. The majority of the larvae were present in the upper layers. Clupeids were the most abundant larvae taxa followed by Myctophidae, Gadidae and Sparidae, hence the larval fish assemblages （LFA） were variable in different depth layers. Total fish larvae showed a preference for surface layers, and were mainly found above 75 m depth, with some exceptions. The maximum concentration of fish larvae was concentrated up to 25 m essentially above the thermocline, where chlorophyll a and mesozooplankton were abundant. Spatially, neritic families were located near the coast and at some offshore stations especially in the northern part, while oceanic families were more distributed towards offshore along the study area. Cluster analysis showed a segregation of two groups of larvae. However, a clear separation between neritic families and oceanic families was not found. Multivariate analysis highlighted the relationship between the distribution of larvae of different families and environmental parameters. Temperature and salinity seem to have been the factors that acted on associations offish larvae. Day/night vertical distributions suggest there was not a very significant vertical migration, probably due to adequate light levels for feeding.

关键词： fish larvae vertical distribution association hydrology multivariate analysis

Destructive and non-destructive evaluation of concrete for optimum sand to aggregate volume ratio

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Frontiers of Structural and Civil Engineering 2021年第6期15卷 1400-1414页

作者： Tarek Uddin MOHAMMED aziz Hasan MAHMOOD Mohammad Zunaied-Bin-HARUN Jamil ahmed JOY MdAsif ahmed Department of Civil and Environmental Engineering Islamic University of Technology(IUT)Organization of Islamic Cooperation(OIC)Board BazarGazipur 1704Bangladesh Centre for Infrastructure Engineering and Safety School of Civil and Environmental EngineeringThe University of New South WalesSydneyNSW 2052Australia Department of Civil Engineering European University of BangladeshMirpurDhaka 1216Bangladesh

Aggregates are the biggest contributor to concrete volume and are a crucial parameter in dictating its mechanical *** such,a detailed experimental investigation was carried out to evaluate the effect of sand-toaggregate volume ratio(s/a)on the mechanical properties of concrete utilizing both destructive and non-destructive testing(employing UPV(ultrasonic pulse velocity)measurements).For investigation,standard cylindrical concrete samples were made with different s/a(0.36,0.40,0.44,0.48,0.52,and 0.56),cement content(340 and 450 kg/m^(3)),water-to-cement ratio(0.45 and 0.50),and maximum aggregate size(12 and 19 mm).The effect of these design parameters on the 7,14,and 28 d compressive strength,tensile strength,elastic modulus,and UPV of concrete were *** careful analysis demonstrates that aggregate proportions and size need to be optimized for formulating mix designs;optimum ratios of s/a were found to be 0.40 and 0.44 for the maximum aggregate size of 12 and 19 mm,respectively,irrespective of the W/C(water-to-cement)and cement content.

关键词： aggregates non-destructive testing sand-to-aggregate volume ratio(s/a) maximum aggregate size(MAS)

Application of Synthetic Iron Oxyhydroxide with Influencing Factors for Removal of As(Ⅴ) and As(Ⅲ) from Groundwater

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Journal of Earth Science 2024年第3期35卷 998-1009页

作者： Shakeel ahmed Talpur Muhammad Yousuf Jat Baloch Chunli Su Javed Iqbal aziz ahmed Hafeez ahmed Talpur School of Environmental Studies China University of GeosciencesWuhan 430078China DiSPUTer Department of PsychologicalHealth and Territory SciencesUniversity“G.d′Annunzio”Chieti-Pescara66100 ChietiItaly College of New Energy and Environment Jilin UniversityChangchun 130021China School of Plant Environment and Soil SciencesLouisiana State University Agricultural CentreBaton Rouge LA 70803USA Department od Engineering and Geology University“G.d′Annunzio”Chieti-Pescara66100 ChietiItaly

Synthesized iron oxyhydroxide was applied for the adsorptive removal of As(V)and As(III)from the aquas ***,this investigation highlighted the synergistic effect of calcium carbonate in conjunction with iron oxyhydroxide,resulting in enhanced removal *** experiment was conducted under various conditions:concentration,dosage,pH,agitation,and *** characterizations such as Brunauer Emmett Teller,X-ray diffraction,scanning electron microscopy,and Fourier transform infrared spectroscopy were implied to understand adsorption *** Langmuir model revealed optimal concentrations for As(V)=500μg/L at pH-5 and As(III)=200μg/L at pH-7,resulting in 95%and 93%adsorption efficiencies,*** adsorption capacities“qm”were found to be 1266.943μg/g for As(V)and 1080.241μg/g for As(III).Freundlich model demonstrated favorable adsorption by indicating“n>1”such as As(V)=2.542 and As(III)=2.707;similarly,the speciation factor“RL<1”for both species as As(V)=0.1 and As(III)=0.5,*** kinetic study presented a pseudo-second-order model as best fitted,indicating throughout chemisorption processes for removing As(V)and As(III).Furthermore,incorporating calcium carbonate presented a significant leap in the removal efficiency,indicating As(V)from 95%to 98%and As(III)from 93%to 96%,*** findings offer profound motivation for developing effective and sustainable solutions to tackle arsenic contamination,underscoring the exceptional promise of iron oxyhydroxide in conjunction with calcium carbonate to achieve maximum removal efficiency.

关键词： adsorption arsenic As(V) As(III) iron oxyhydroxide isotherms kinetics groundwater.

Time-dependent reliability and resilience of aging structures exposed to multiple hazards in a changing environment

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Resilient Cities and Structures 2022年第3期1卷 40-51页

作者： Cao Wang Bilal M.Ayyub aziz ahmed School of Civil Mining and Environmental EngineeringUniversity of WollongongWollongongNSW 2522Australia Center for Technology and Systems Management Department of Civil and Environmental EngineeringUniversity of MarylandCollege ParkMaryland 20742United States

Engineering structures are often subjected to the influences of performance deterioration and multiple hazards during their service lives,and consequently may suffer from damage/failure as a result of external *** reliability and resilience assessment is a powerful tool for quantifying the structural ability to withstand these environmental or operational *** paper proposes new formulas for structural time-dependent reliability and resilience analyses in the presence of multiple hazards,which are functions of the duration of the reference period of *** joint impacts of nonstationarities in multiple hazards due to a changing environment,as well as the deterioration of structural performance,are explicitly *** correlation between the structural resistances/capacities associated with different hazard types is modeled by employing a copula *** is observed that,under the context of multiple hazards and aging effects,the time-dependent resilience takes a generalized form of time-dependent *** proposed formulas can be used to guide the adaptive design of structures,where adaptive strategies are identified across a range of possible future service *** example is presented to demonstrate the applicability of the proposed method for structural reliability and resilience analyses.

关键词： Time-dependent reliability Time-dependent resilience Repairable structures Climate change Multiple hazards Adaptive design

Dendritic cell co-stimulatory and co-inhibitory markers in chronic HCV: An Egyptian study

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World Journal of Gastroenterology 2013年第43期19卷 7711-7718页

作者： Hanan Fouad Maissa Saeed El Raziky Rasha ahmed Abdel aziz Dina Sabry Ghada Mahmoud Abdel aziz Manal Ewais ahmed Reda Sayed Medical Biochemistry Department Faculty of MedicineCairo University11562 CairoEgypt Gastroenterology and Tropical Department Faculty of MedicineCairo University11562 CairoEgypt Medical Biochemistry Department Faculty of MedicineBeni Sueif University19206 Kornish Al NileBani SweifEgypt

AIM:To assess co-stimulatory and co-inhibitory markers of dendritic cells(DCs)in hepatitis C virus(HCV)infected subjects with and without ***:Three subject groups were included in the study:group 1 involved 50 control subjects,group2 involved 50 patients with chronic HCV infection and group 3 involved 50 HCV uremic subjects undergoing ***83,CD86 and CD40 as co-stimulatory markers and PD-L1 as a co-inhibitory marker were assessed in peripheral blood mononuclear cells by realtime polymerase chain ***-10(IL-10)and hyaluronic acid(HA)levels were also *** findings were correlated with disease activity,viral load and ***:There was a significant decrease in costimulatory markers;CD83,CD86 and CD40 in groups2 and 3 vs the control ***-stimulatory markers were significantly higher in group 3 vs group *** was a significant elevation in PD-L1 in both HCV groups vs the control ***-L1 was significantly lower in group 3 vs group *** was a significant elevation in IL-10 and HA levels in groups 2 and 3,where IL-10was higher in group 3 and HA was lower in group 3 vs group *** level was significantly correlated with disease activity and fibrosis grade in group ***-10 was significantly correlated with fibrosis grade in group *** were significant negative correlations between co-stimulatory markers and viral load in groups 2 and3,except CD83 in dialysis *** was a significant positive correlation between PD-L1 and viral load in both HCV ***:A significant decrease in DC co-stimulatory markers and a significant increase in a DC coinhibitory marker were observed in HCV subjects and to a lesser extent in dialysis patients.

关键词： Hepatitis C virus Uremia Hemodialysis Dendritic cells CD83 CD86,CD40 PD-L1 Interleukin-10 Hyaluronic acid