检索结果-南通市图书馆

Clinical and Genetic Study of Friedreich’s Ataxia and Ataxia with Vitamin E Deficiency in 44 Moroccan Families

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Neuroscience 2014年第4期4卷 299-305页

作者： Fatima Imounan Naima Bouslam El Hachmia Aitbenhaddou Wafa Regragui Ahmed Bouhouche ali benomar Mohammed Yahyaoui Center for Research in Clinical Epidemiology and Therapeutic Trials (CRECET) Faculty of Medicine and Pharmacy Mohammed V University at Souissi Rabat Morocco Neurology B and Neurogentics Specialty Hospital ONO CHU Rabat-Sale Morocco

Introduction: Friedreich ataxia (FRDA) is a multi-system autosomal-recessive disease, the most common one of the genetically inherited ataxias. FRDA occurs as a consequence of mutations in the frataxin gene, with an expansion of a GAA trinucleotide. Ataxia with vitamin E deficiency (AVED) is characterized clinically by neurological symptoms with often striking resemblance to those of Friedreich’s ataxia (FA) but serum concentrations of vitamin E are low. Aim of study: To study clinical and genetic features of the Friedreich’s ataxia and AVED patients in 44 Moroccan families. Patients and Methods: Retrospective series of 72 Moroccan patients displaying Friedreich’s ataxia syndrome was recruited over a period of 22 years (1987-2009). All patients had a clinical and ophtalmological examinations, 30 patients underwent electromyography, and CT scan was performed in 29 patients. GAA repeats in the frataxin gene and the 744 del A mutation α-TTP gene were performed in all patients. Results: 17 patients (24% of cases) had the 744 del A mutation in the α-TTP gene responsible of ataxia with vitamin E deficiency (AVED) phenotype. 55 patients ?(76% of cases) had GAA expanded allele in the first intron of the frataxin gene. Phenotype-genotype correlation revealed a high frequency of head titubation, decreased visual acuity and slower disease progression in AVED than in Friedreich’s ataxia phenotype (p Our study represents a large series which highlight the clinical and genetic differences between AVED and Friedreich’s ataxia. AVED patients have a better prognosis after alpha-tocopherol treatment.

关键词： Friedreich’s Ataxia Ataxia with Vitamin E Deficiency GAA Expansion 744 Del A Mutation

Vitamin E in ataxia and neurodegenerative diseases:A review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Neuroscience 2012年第4期2卷 217-222页

作者： Fatima Imounan Naima Bouslam Jehanne Aasfara Kaoutar El Alaoui Wafa Regragui El Hachmia Ait Benhaddou Ahmed Bouhouche ali benomar Mohamed Yahyaoui Mohammed V Souissi University CHU Ibn SinaNeurology B and Neurogenetics DepartmentHopital des SpecialitesRabatMorocco Mohammed V Souissi University Faculte de Medecine et de Pharmacie RabatCentre de Recherche en Epidemiologie Clinique et Essais Therapeutiques(CRECET)RabatMorocco

Vitamin E is one of the most important lipid-soluble antioxidants. It is essential for the neurological function but its role in the central nervous system has not fully been elucidated. It is known that tocopherol acts in protecting cell membranes from oxidative damage and it can act as an anti-in?ammatory agent, which may also be neuroprotective, as well as regulating speci?c enzymes. There is growing evidence that oxidative stress plays a key role in the pathophysiology of several neurodegenerative disorders. These diseases are defined by the progressive loss of speci?c neuronal cell populations and are associated with protein aggregates. We reviewed some aspects related to the role of antioxidant properties of Vitamin E in preventing and/or curing neurodegenerative disorders such as the Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, ataxia, tardive dyskinesia and Huntington’s disease.

关键词： Vitamin E Neurodegenerative Diseases Ataxia with Vitamin E Deficiency

Genuine entanglement under squeezed generalized amplitude damping channels with memory

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第2期33卷 158-163页

作者： Mazhar ali Department of Electrical Engineering Faculty of EngineeringIslamic University MadinahMadinah 107Saudi Arabia

We study genuine entanglement among three qubits undergoing a noisy process that includes dissipation, squeezing,and decoherence. We obtain a general solution and analyze the asymptotic quantum states. We find that most of these asymptotic states can be genuinely entangled depending upon the parameters of the channel, memory parameter, and the parameters of the initial states. We study Greenberger–Horne–Zeilinger(GHZ) states and W states, mixed with white noise,and determine the conditions for them to be genuinely entangled at infinity. We find that for these mixtures, it is possible to start with a bi-separable state(with a specific mixture of white noise) and end with genuine entangled states. However, the memory parameter μ must be very high. We find that in contrast to the two-qubit case, none of the three-qubit asymptotic states for n → ∞ are genuinely entangled.

关键词： genuine entanglement squeezed thermal baths multipartite states

Heat transfer analysis in particle-laden flows using the immersed boundary method

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第7期90卷 394-403页

作者： ali Abbas Zaidi Department of Mechanical Engineering University of Manitoba75A Chancellors CircleWinnipegR3T 5V6Canada

This paper investigates an efficient immersed boundary method(IBM)for multiple-core CPU machines with local grid refinement for the calculation of heat transfer between fluids and finite-sized *** fluid momentum equations are solved by using the fractional step method,while the energy equation is solved by employing the second-order Adams-Bashforth *** efficient load balancing between the CPU cores,the coupling between particles and fluid is obtained by applying the body force in the fluid equations,which depends on the solid volume fraction of particles contained in each grid cell,and then by linearly interpolating the particle temperature and velocity on the fluid grid cell(in place of the delta function commonly used in literature).Several test cases from the literature are studied,and good agreement is observed between the simulation results and the ***,a scaling study on multiple core machines is performed,demonstrating the proposed IBM's capabilities for a significant reduction in processing time.

关键词： Heat transfer Immersed boundary method Particle resolved direct numerical simulations Fluid solid interactions

Simulation of the deformable lateral boundaries in biaxial test using DEM

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第5期88卷 161-175页

作者： ali Momeni Barry Clarke Yong Sheng ali Hassanpour WSP 3 Wellington PlaceLeedsLS1 4APUK Hull University HullHU6 7RXUK School of Civil Engineering University of LeedsLeedsLS2 9JTUK School of Computer Science University of HullHullHU6 7RXUK School of Chemical and Process Engineering University of LeedsLeedsLS2 9JTUK

Applying the discrete element method(DEM)in soil mechanics can provide abundant information at the particle-scale and facilitates illustration of the macro-mechanical behaviour of soils based on the inter-particle *** triaxial test is one of the most common laboratory methods to study the macro-mechanical behaviour of particulate materials such as ***,many problems in geotechnical design can be assumed and simplified as a plane strain *** a biaxial test can be conducted to reproduce the macro-mechanical behaviour of soil,where the sample is enclosed by two horizontal rigid platens and a vertical latex membrane,which is a deformable continuous element and allows the enclosed specimen to deform freely while maintaining confining stress during *** paper presents an algorithm to represent physical and mechanical characteristics of latex membrane in the 2D DEM simulation of biaxial test using the PFC^(2D) *** investigate the impact of the lateral boundary conditions on the micro-macro mechanical behaviours of soil samples,two sets of DEM biaxial tests are conducted,*** rigid and deformable lateral boundary *** DEM modeling results indicate that the lateral boundary conditions have a significant effect on the micro-scale fabric properties,thickness and inclination of the shear *** comparison between these two simulations also demonstrates that the lateral boundary conditions play a major role in the peak and post-peak stress-strain behaviours as well as the dilation and critical state behaviours of granular soils.

关键词： Discrete element method Biaxial test Deformable boundaries Shear band Critical state Fabric anisotropy Geometrical stability index

Sensing the heavy water concentration in an H_(2)O-D_(2)O mixture by solid-solid phononic crystals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第4期33卷 493-498页

作者： Mohammadreza Rahimi ali Bahrami Optoelectronic and Nanophotonics Research Laboratory(ONRL) Faculty of Electrical EngineeringSahand University of TechnologyTabrizIran

A new method based on phononic crystals is presented to detect the concentration of heavy water(D_(2)O)in an H_(2)O-D_(2)O *** have been obtained and analyzed in the concentration range of 0%-10%and 90%-100%D_(2)O.A proposed structure of tungsten scatterers in an aluminum host is *** order to detect the target material,a cavity region is considered as a sound wave resonator in which the target material with different concentrations of D_(2)O is *** changing the concentration of D_(2)O in the H_(2)O-D_(2)O mixture,the resonance frequency undergoes a frequency *** 1%change in D_(2)O concentration in the H_(2)O-D_(2)O mixture causes a frequency change of about 120 *** finite element method is used as the numerical method to calculate and analyze the natural frequencies and transmission spectra of the proposed *** performance evaluation index shows a high Q factor up to 1475758 and a high sensitivity up to 13075,which are acceptable values for sensing *** other figures of merit related to the detection performance also indicate high-quality performance of the designed sensor.

关键词： phononic crystals sensor H_(2)O-D_(2)O mixture cavity

Note on Lower Triassic Gondolelloid Conodont Rediversifications with Emphasis on the Spathian Recovery

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年第4期35卷 1236-1242页

作者： ali Murat Kilic Department of Geological Engineering Faculty of EngineeringBalikesir UniversityBalikesir99100Turkey

Conodonts,as a biotic group,next to ammonoids,pollen and spores,crustaceans and vertebrates,provide proxy clues for environment and age assessments of the rocks in which they *** are widely used for Triassic marine ***,there are various discussions about their multielement taxonomy and evolutionary lineages(e.g.,generation,speciation).Although first studies reported that most Triassic conodont species were unimembrate,studies carried out in the following years maintained that all Triassic conodonts were *** statistical reconstructions of a number of Triassic apparatuses were attempted,the discovery of fused clusters and natural assemblages has subsequently demonstrated that Triassic conodonts are indeed multimembrate,and all of the elements exist together in the same *** present paper aims to clarify the evolutionary relationship and array of some Lower Triassic *** dagisi *** described.

关键词： Triassic Spathian conodont Columbitella Siberia environmental geology

Experimental Study on Heat Storage Properties Comparison of Paraffin/Metal Foams Phase Change Material Composites

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第2期33卷 469-478页

作者： Waqar AHMED Abid HUSSAIN Hanzla SHAHID Imran ali Hafiz Muhammad ali Department of Mechanical Engineering University of Engineering and TechnologyTaxila47080Pakistan Department of Mechanical Engineering Institute of Space TechnologyIslamabadPakistan Department of Mechanical Mechatronics and Manufacturing EngineeringUniversity of Engineering and Technology LahoreFaisalabad CampusPunjabPakistan Mechanical Engineering Department King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia Interdisciplinary Research Center for Renewable Energy and Power Systems(IRC-REPS) King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia

Heat storage properties of phase change materials(PCMs) are essential characteristics that perform a key role in thermal heat energy storage *** thermal properties of PCMs can be improved by developing metal foam/PCM *** addition of metal foam in PCMs has a significant effect on the thermal characteristics of *** this paper,the heat storage properties of two different metal foam/PCM composites were experimentally *** behavior of paraffin in metal foam(copper and iron-nickel)/paraffin composites concerning pure paraffin at a constant heat flux of 1000 W/m^(2) in three directions simultaneously(x,y,and z) was *** was infiltrated into copper and iron-nickel foams to develop composite materials which resulted in enhancing the thermal conductivity of the paraffin.A comparative analysis is made on the heat storage properties of paraffin in copper and iron-nickel foams/paraffin *** temperature distribution during the phase transition process is experimentally *** comparison indicates that temperature uniformity in copper foam/paraffin composite is better than in iron-nickel foam/paraffin composite and pure paraffin at the same heat *** results show that at heat flux of 1000 W/m^(2),the heat storage time for copper foam/paraffin composite is 20.63% of that of iron-nickel foam/paraffin composite.

关键词： heat storage capacity paraffin/metal foam composite temperature uniformity heat storage rate phase transition process

Association Study of Two Polymorphisms in Vitamin D Pathway with Multiple Sclerosis in the Moroccan Population

在线全文

学校读者我要写书评

暂无评论

World Journal of Neuroscience 2017年第4期7卷 363-375页

作者： Asmae Skalli El Hachmia Ait Ben Haddou Rachid Tazi-Ahnini Ghislain Armel Mpandzou Houyam Tibar Naima Bouslam ali benomar Khadija Hajjout Mohamed Yahyaoui Elmostafa El Fahime Ahmed Bouhouche Research Team in Neurology and Neurogenetics Medical School and Pharmacy Mohammed V University Rabat Morocco Department of Neurology and Neurogenetics Specialties Hospital Rabat Morocco Laboratory of Biotechnology Medical School and Pharmacy Mohammed V University Rabat Morocco National Blood Transfusion Center Rabat Morocco Assistance Units for Scientific and Technical Research Rabat Morocco

Background: Hypovitaminosis D is reported through the literature to be involved in autoimmune diseases such as multiple sclerosis (MS). In the last decade, numerous studies have investigated the association of single nucleotide polymorphisms (SNPs) with MS, including rs2248359 (CYP24A1) and rs703842 (CYP27B1) that are involved in vitamin D metabolic pathway. However, results were conflicting, probably due to ethnic differences between the studied populations. In this context, the present study aimed to analyze the association between these two SNPs and MS within the Moroccan population. Methods: rs2248359 and rs703842 were genotyped in 113 patients and 146 healthy controls. To assess their association with the disease risk, we compared the genotypic and allelic frequencies between the study groups. We also explored their possible influence on certain clinical features (age at onset, type, disability status and severity score) and with vitamin D3 serum level (DSL) by comparing mean values of these variables between the different genotypes. Results: No statistically significant differences in the distribution of both SNPs were found between patients and controls. A trend has emerged concerning the minor G allele of rs703842 which appears to have a protective effect on developing MS, but this result remained slightly below significance. Also, the two polymorphisms had no impact on the clinical features tested and the DSL. Conclusion: There is no convincing evidence that rs2248359 and rs703842 are associated with MS risk, its clinical features or vitamin D level in Moroccans. Further larger investigations are needed to confirm these findings.

关键词： Multiple Sclerosis Risk rs2248359 rs703842 Clinical Features Serum 25(OH)D3 Level