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Bone mineral density and disorders of mineral metabolism in chronic liver disease

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World Journal of Gastroenterology 2009年第28期15卷 3516-3522页

作者： Joe George Hosahithlu K Ganesh Shrikrishna Acharya Tushar R Bandgar Vyankatesh Shivane Anjana Karvat Shobna J Bhatia samir shah Padmavathy S Menon Nalini shah Department of Endocrinology Seth G.S. Medical College and KEM Hospital Department of Gastroenterology Seth G.S Medical College and KEM Hospital Department of Gastroenterology Jaslok Hospital

AIM： To estimate the prevalence and identify the risk factors for metabolic bone disease in patients with cirrhosis. METHODS： The study was performed on 72 Indian patients with cirrhosis （63 male, 9 female; aged 〈 50 years）. Etiology of cirrhosis was alcoholism （n = 37）, hepatitis B （n = 25） and hepatitis C （n = 10）. Twenty-three patients belonged to Child class A, while 39 were in class B and 10 in class C. Secondary causes for metabolic bone disease and osteoporosis were ruled out. Sunlight exposure, physical activity and dietary constituents were calculated. Complete metabolic profiles were derived, and bone mineral density （BMD） was measured using dual energy X ray absorptiometry. Low BMD was defined as a Z score below -2. RESULTS： Low BMD was found in 68% of patients. Lumbar spine was the most frequently and severely affected site. Risk factors for low BMD included low physical activity, decreased sunlight exposure, and low lean body mass. Calcium intake was adequate, with unfavorable calcium： protein ratio and calcium： phosphorus ratio. Vitamin D deficiency was highly prevalent （92%）. There was a high incidence of hypogonadism （41%）. Serum estradiol level was elevated significantly in patients with normal BMD. Insulin-like growth factor （IGF） 1 and IGF binding protein 3 levels were below the age-related normal range in both groups. IGF-1 was significantly lower in patients with low BMD. Serum osteocalcin level was low （68%） and urinary deoxypyridinoline to creatinine ratio was high （79%）, which demonstrated low bone formation with high resorption. CONCLUSION： Patients with cirrhosis have low BMD. Contributory factors are reduced physical activity, low lean body mass, vitamin D deficiency and hypogonadism and low IGF-1 level.

关键词： Bone mineral density Liver disease Chronic disease Cirrhosis Bone mineral metabolism Hepatic osteodystrophy

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小婴儿腰椎穿刺脑脊液参考值

中国循证儿科杂志 2019年第4期14卷 317-318页

作者： Joanna Thomson Heidi Sucharew Andrea T. Cruz Lise E. Nigrovic MD, MPH Stephen B. Freedman Aris C. Garro Fran Balamuth Rakesh D. Mistry Joseph L. Arms Paul T. Ishimine Dina M. Kulik Mark I. Neuman samir S. shah 郑继翠(译) 李凯(校) Divisions of Hospital Medicine Cincinnati Children's Hospital Medical CenterCincinnatiOhio Departments of Emergency Medicine and Pediatrics School of MedicineUniversity of CaliforniaSan Diego and Rady Children's Hospital-San DiegoSan DiegoCalifornia University of Toronto TorontoCanada 不详 Biostatistics and Epidemiology and lInfectious DiseasesCincinnati Children's Hospital Medical CenterCincinnatiOhio Sections of Emergency Medicine and Infectious Diseases Baylor College of MedicineHoustonTexas Division of Emergency Medicine Boston Children's HospitalBostonMassachusetts Sections of Pediatric Emergency Medicine and Gastroenterology Department of PediatricsAlberta Children's Hospital Research InstituteAlberta Children's HospitalCumming School of MedicineUniversity of CalgaryCalgaryCanada Warren Alpert Medical School Brown UniversityProvidenceRhode Island Perelman School of Medicine University of PennsylvaniaPhiladelphiaPennsylvania School of Medicine University of ColoradoAuroraColorado Children's Hospitals and Clinics of Minnesota MinneapolisMinnesota

研究背景既往有关脑脊液(CSF)参考值的研究为单中心研究,且样本量较小,因此其应用价值有限。研究新知这项多中心横断面调查研究确定了不同日龄段婴儿的CSF参考值,并且提供了日龄相关CSF百分位参考曲线。

关键词：参考值脑脊液小婴儿腰椎穿刺横断面调查 CSF 样本量多中心

Stabilization and Synchronization of Discrete-time Fractional Chaotic Systems with Non-identical Dimensions

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Acta Mathematicae Applicatae Sinica 2021年第3期37卷 523-538页

作者： samir BENDOUKHA Department of Electrical Engineering College of EngineeringYanbuTaibah UniversitySaudi Arabia

This paper investigates the stabilization and synchronization of two fractional chaotic maps proposed recently,namely the 2D fractional Hénon map and the 3D fractional generalized Hénon *** show that although these maps have non–identical dimensions,their synchronization is still *** proposed controllers are evaluated experimentally in the case of non–identical orders or time–varying *** methods are used to illustrate the results.

关键词： discrete chaos fractional discrete calculus Hénon based maps stabilization synchronization

DUALITY OF GENERALIZED DUNKL-LIPSCHITZ SPACES

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Acta Mathematica Scientia 2017年第6期37卷 1567-1593页

作者： samir KALLEL Department of Mathematics Higher Institute of Computer Sciences and Mathematics of MonastirMonastir University5000 MonastirTunisia

Abstract The aim of this paper is to prove duality and reflexivity of generalized Lipschitz spaces ∧κα,p,q（R）, α ∈R and 1≤〈 p, q ≤∞, in the context of Dunkl harmonic analysis.

关键词： Dunkl operator duality Herz spaces heat transform Dunkl transform gen-eralized Dunkl-Lipschitz spaces

The effects of exhaust air vent location on thermal comfort inside a residential building equipped with an evaporative cooling system

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Building Simulation 2021年第4期14卷 1063-1075页

作者： rmin Saraei samir Farid Moujaes Department of Mechanical Engineering College of EngineeringUniversity of Nevada Las VegasLas VegasNV89154USA

The location of exhaust air vents of an evaporative cooling system can have significant effects on providing thermal comfort and controlling humidity, temperature and air distribution in buildings. In the current study, four different strategies have been evaluated for exhaust air vent locations to provide the optimum thermal comfort inside a typical residential house. This study provides a numerical solution for temperature and relative humidity profiles in the residential house and within the living space in each room typically at a height of 1.8 m or less. By evaluating different exhaust air vent locations in a room, the best strategy(ies) to provide more appropriate thermal comfort condition and obtained and as a conclusion, the exhaust vents should be located on furthest wall away from the entrance of the room and in the middle. The results provided in the current study can eventually be applied in the design of evaporative cooler exhaust vent systems in residential buildings and lead to improve the performance of these systems.

关键词： thermal comfort CFD evaporative cooling system exhaust air vents

Finite Elementθ-Schemes for the Acoustic Wave Equation

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Advances in Applied Mathematics and Mechanics 2011年第2期3卷 181-203页

作者： samir Karaa Department of Mathematics and Statistics Sultan Qaboos UniversityP.O.Box 36Al-Khod 123MuscatSultanate of Oman

In this paper,we investigate the stability and convergence of a family of implicit finite difference schemes in time and Galerkin finite element methods in space for the numerical solution of the acoustic wave *** schemes cover the classical explicit second-order leapfrog scheme and the fourth-order accurate scheme in time obtained by the modified equation *** derive general stability conditions for the family of implicit schemes covering some well-known CFL *** error estimates are *** sufficiently smooth solutions,we demonstrate that the maximal error in the L^(2)-norm error over a finite time interval converges optimally as O(h^(p+1)+∆t^(s)),where p denotes the polynomial degree,s=2 or 4,h the mesh size,and∆t the time step.

关键词： Finite element methods discontinuous Galerkin methods wave equation implicit methods energy method stability condition optimal error estimates

Simulation and analysis of resin flow in injection machine screw

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第3期9卷 338-345页

作者： Ling-feng LI samir MEKID College of Mechanical and Energy Engineering Zhejiang University Hangzhou 310027 China School of Mechanical Aerospace and Civil Engineering University of Manchester Manchester UK

A method with simulation and analysis of the resin flow in a screw is presented to ease the control of some problems that may affect the efficiency and the quality of the product among existing screws in an injection machine. The physical model of a screw is established to represent the stress, the strain, the relationship between velocity and stress, and the temperature of the cells. In this paper, a working case is considered where the velocity and the temperature distributions at any section of the flow are obtained. The analysis of the computational results shows an ability to master various parameters depending on the specifications.

关键词： Screw Plasticity Velocity distribution Temperature distribution

Spatial Variability and Cartography of Maximum Annual Daily Rainfall under Different Return Periods in Northern Algeria

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Journal of Mountain Science 2015年第6期12卷 1403-1421页

作者： MEDDI Mohamed TOUMI samir National High School of Hydraulic (ENSH)

The estimation of precipitation quantiles has always been an area of great importance to meteorologists, hydrologists, planners and managers of hydrotechnical infrastructures. In many cases, it is necessary to estimate the values relating to extreme events for the sites where there is little or no measurement, as well as their return periods. A statistical approach is the most used in such cases. It aims to find the probability distribution that best fits the maximum daily rainfall values. In our study, 231 rainfall stations were used to regionalize and find the best distribution for modeling the maximum daily rainfall in Northern Algeria. The L-moments method was used to perform a regionalization based on discordance criteria and homogeneity test. It gave rise to twelve homogeneous regions in terms of LCoefficient of variation(L-CV), L-Skewness(L-CS) and L-Kurtosis(L-CK). This same technique allowed us to select the regional probability distribution for each group using the Z statistic. The generalized extreme values distribution(GEV) was selected to model the maximum daily rainfall of 10 groups located in the north of the steppe region and the generalized logistic distribution(GLO) for groups representing the steppes of Central and Western Algeria. The study of uncertainty by the bias and RMSE showed that the regional approach is acceptable. We have also developed maximum daily rainfall maps for 2, 5, 10, 20, 50 and 100 years return periods. We relied on a network of 255 rainfall stations. The spatial variability of quantiles was evaluated by semi-variograms. All rainfall frequency models have a spatial dependence with an exponential model adjusted to the experimental semi-variograms. The parameters of the fitted semi-variogram for different return periods are similar, throughout, while the nugget is more important for high return periods. Maximum daily rainfall increases from South to North and from West to East, and is more significant in the coastal areas of ea

关键词： Annual maximum daily rainfall Regionalisation L-moments Mapping Northern Algeria

BEZIER SPLINES INTERPOLATION ON STIEFEL AND GRASSMANN MANIFOLDS

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Journal of Computational Mathematics 2024年第6期42卷 1554-1578页

作者： Ines Adouani Chafik samir Department of Mathematics University of SousseTunisia LIMOS-CNRS University of Clermont AuvergneFrance

We propose a new method for smoothly interpolating a given set of data points on Grassmann and Stiefel manifolds using a generalization of the De Casteljau *** that end,we reduce interpolation problem to the classical Euclidean setting,allowing us to directly leverage the extensive toolbox of spline *** interpolated curve enjoy a number of nice properties:The solution exists and is optimal in many common *** applications,the structures with respect to chosen Riemannian metrics are detailed resulting in additional computational advantages.

关键词： Optimization B´ezier spline Curve fitting Grassmann manifolds Stiefel manifolds Canonical metrics