检索结果-南通市图书馆

A spotlight on dosage and subject selection for effective neuroprotection: exploring the central role of mitochondria

在线全文

学校读者我要写书评

暂无评论

Neural regeneration research 2025年第4期20卷 1081-1082页

作者： John mitrofanis Jonathan Stone michael r.Hamblin Pierre magistretti Alim-Louis Benabid Glen Jeffery Fonds Clinatec UniversitéGrenoble AlpesGrenobleFrance School of medical Science University of SydneySydneyAustralia Faculty of Health Sciences University of JohannesburgJohannesburgSouth Africa King Abdullah University of Science and Technology ThuwalSaudi Arabia Institute of Ophthalmology University College LondonLondonUK

Neurons are notoriously vulnerable cell *** the slightest change in their internal and/or external environments will cause much distress and dysfunction,leading often to their death.A range of pathological conditions,including stroke,head trauma,and neurodegenerative disease,can generate stress in neurons,affecting their survival and proper *** most neural pathologies,mitochondria become dysfunctional and this plays a pivotal role in the process of cell *** challenge over the last few decades has been to develop effective interventions that improve neuronal homeostasis under pathological *** interventions,often referred to as disease-modifying or neuroprotective,have,however,proved frustratingly elusive,at both preclinical and,in particular,clinical *** this perspective,we highlight two factors that we feel are key to the development of effective neuroprotective *** are:firstly,the choice of dose of intervention and method of application,and secondly,the selection of subjects,whether they be patients or the animal model.

关键词： protective dosage distress

Spectral Behavior and Flaring Activity ofⅡPeg in the Ultraviolet

在线全文

学校读者我要写书评

暂无评论

research in Astronomy and Astrophysics 2022年第8期22卷 191-197页

作者： m.r.Sanad Astronomy Department National Research Institute of Astronomy and GeophysicsHelwanCairoEgypt

We have studied the spectral behavior of theⅡPeg binary system in the ultraviolet band by using International Ultraviolet Explorer(IUE)observations over the period *** ultraviolet observations reveal indication of flare activity in both chromosphere and transition region with their enhanced emission *** and after the flare activity the ultraviolet emission lines show low,intermediate and high *** spectral behavior is compared with previous *** detect prominent flare activity in 1989,1990 and *** and after this period there is a gradual clear decrease in the level of *** reddening ofⅡPeg was determined from a 2200?absorption feature to be E(B-V)=0.10±*** ascertained the average mass loss rate to be≈1×10^(-8)m_(☉)yr^(-1),and an average ultraviolet luminosity to be≈6×10^(29)erg s^(-1).We attributed the spectral variations to a cyclic behavior of the underlying magnetic dynamo and the prominent activity can be interpreted by the model of a two-ribbon flare.

关键词： line:profiles magnetic fields stars:activity stars:flare ultraviolet:stars

Gene therapy for spinal muscular atrophy:perspectives on the possibility of optimizing SmN1 delivery to correct all neurological and systemic perturbations

在线全文

学校读者我要写书评

暂无评论

Neural regeneration research 2025年第7期20卷 2011-2012页

作者： Sharon J.Brown rafael J.Yáñez-muñoz Heidi r.Fuller School of Pharmacy and Bioengineering Keele UniversityKeeleUK Wolfson Center for Inherited Neuromuscular Disease TORCH BuildingRJAH Orthopaedic HospitalOswestryUK *** Center of Gene and Cell TherapyDepartment of Biological SciencesSchool of Life Sciences and the EnvironmentRoyal Holloway University of LondonEghamUK

Spinal muscular atrophy(SmA)is a genetic condition that results in selective lower motor neuron loss with concomitant muscle weakness and *** genetic cause of SmA was understood in 1995 when loss or impairment of the survival motor neuron 1(SmN1)gene was identified as the main contributing factor(Lefebvre et al.,1995).This,in combination with the discovery that humans have a“back-up”gene,SmN2,which can produce low levels(approximately 10%)of the full-length functional SmN protein,has led to the generation of SmA-specific gene *** was traditionally classified according to age of symptom onset and developmental milestones achieved,with life expectancy and severity varying between ***,SmN2 copy number is used as a proxy for the prediction of disease severity,with higher SmN2 copy number typically being associated with reduced severity of SmA,although this relationship is not absolute:some individuals with low SmN2 copy number have less severe SmA phenotypes and vice ***,the etiology of SmA is further complicated by other factors,such as non-typical nucleotide variants and SmN2-independent modifiers of disease severity.

关键词： atrophy traditionally absolute

multiple Parameter Based Clustering (mPC): Prospective Analysis for Effective Clustering in Wireless Sensor Network (WSN) Using K-means Algorithm

在线全文

学校读者我要写书评

暂无评论

Wireless Sensor Network 2012年第1期4卷 18-24页

作者： md. Asif Khan Israfil Tamim Emdad Ahmed m. Abdul awal 不详

In wireless sensor network cluster architecture is useful because of its inherent suitability for data fusion. In this paper we represent a new approach called multiple Parameter based Clustering (mPC) embedded with the traditional k-means algorithm which takes different parameters (Node energy level, Euclidian distance from the base station, rSSI, Latency of data to reach base station) into consideration to form clusters. Then the effectiveness of the clusters is evaluated based on the uniformity of the node distribution, Node range per cluster, Intra and Inter cluster distance and required energy level of each centroid. Our result shows that by varying multiple parameters we can create clusters with more uniformly distributed nodes, minimize intra and maximize inter cluster distance and elect less power consuming centroid.

关键词： K-means Algorithm Energy Efficient Uniform Distribution rSSI Latency

Gas pressure effect on plasma transport in a magnetic-filtered radio-frequency plasma source

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2020年第6期22卷 103-109页

作者： N OUDINI m m ALIm r TADJINE A BENDIB Laboratoire des Plasmas de Décharges Centre de Développement des Technologies AvancéesCitédu 20 Aout BP 17 Baba Hassen16081 AlgiersAlgeria Laboratoire d’Electronique Quantique Facultéde PhysiqueUSTHBEl Alia BP 32Bab Ezzouar 16111AlgiersAlgeria

Volume negative ion production relies on a magnetic filter(mF),where the plasma downstream of the mF is characterized by a strip-like pattern that consists of a bright and dense plasma *** this work,we study,in a radio-frequency plasma source,the effects of operating pressure on this *** investigation,conducted using a Langmuir probe,shows that the plasma uniformity might be controlled through the gas ***,the operating pressure determines on which hemi-cylinder(side of magnetic field lines)the strip *** side inversion of the high-density plasma hemi-cylinder is due to an inversion of an ambipolar electric field that changes the E?×?B drift direction.

关键词： magnetic filter radio-frequency plasma source Langmuir probe E×B drift ambipolar electric field

Nonlinear dynamic modeling of planar moving Timoshenko beam considering non-rigid non-elastic axial effects

在线全文

学校读者我要写书评

暂无评论

Applied mathematics and mechanics(English Edition) 2024年第3期45卷 479-496页

作者： m.ABBASI GAVArI m.r.HOmAEINEZHAD Faculty of mechanical Engineering K.N.Toosi University of TechnologyTehran 19991-43344Iran

Due to the importance of vibration effects on the functional accuracy of mechanical systems,this research aims to develop a precise model of a nonlinearly vibrating single-link mobile flexible *** manipulator consists of an elastic arm,a rotary motor,and a rigid carrier,and undergoes general in-plane rigid body motion along with elastic transverse *** accurately model the elastic behavior,Timoshenko’s beam theory is used to describe the flexible arm,which accounts for rotary inertia and shear deformation *** applying Newton’s second law,the nonlinear governing equations of motion for the manipulator are derived as a coupled system of ordinary differential equations(ODEs)and partial differential equations(PDEs).Then,the assumed mode method(Amm)is used to solve this nonlinear system of governing equations with appropriate shape *** assumed modes can be obtained after solving the characteristic equation of a Timoshenko beam with clamped boundary conditions at one end and an attached mass/inertia at the *** addition,the effect of the transverse vibration of the inextensible arm on its axial behavior is *** the axial rigidity,the effect makes the rigid body dynamics invalid for the axial behavior of the ***,numerical simulations are conducted to evaluate the performance of the developed model,and the results are compared with those obtained by the finite element *** comparison confirms the validity of the proposed dynamic model for the *** to the mentioned features,this model can be reliable for investigating the system’s vibrational behavior and implementing vibration control algorithms.

关键词： planar moving Timoshenko beam non-rigid non-elastic axial effect as-sumed mode method(Amm) nonlinear motion analysis

Nuclear radiation shielding effectiveness and corrosion behavior of some steel alloys for nuclear reactor systems

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2019年第4期15卷 621-628页

作者： m.m. Sadawy r.m. El Shazly mining and Petroleum Engineering Department Al-Azhar University Nasr City Cairo 11371 Egypt Physics Department Faculty of Science Al-Azhar University Nasr City Cairo 11884 Egypt

Different types of nuclear parameters and corrosion behavior were deduced for carbon steel(AISI 1018),austenitic(304 SS),and duplex(2507 SS)stainless steel *** types of neutron energies as well as nine gamma ray energy lines(121.78-1407.92 keV)were used to evaluate the macroscopic neutron cross-sections(∑,cm^-1)and mass attenuation coefficients[σ,cm^2·g^-1)of gamma ray *** corrosion behavior was investigated using different electrochemical *** results showed that the stainless-steel alloys had a good attitude than that of carbon steel alloy for neutron and gamma ray parameters,especially the duplex stainless *** calculated values of mass attenuation coefficient using WinXcom computer program(Version 3.1),exhibited a very good agreement with the experimental values of that ***,the results indicated that duplex stainless-steel exhibited corrosion resistance higher than 304 SS and AISI 1018 steel alloys.

关键词： Steel alloys macroscopic cross-section mass attenuation coefficient Passive film Pitting

Control over hysteresis curves and thresholds of optical bistability in different semiconductor double quantum wells

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2015年第8期24卷 373-380页

作者： Hamedi H r mehmannavaz m r Afshari Hadi Institute of Theoretical Physics and Astronomy Vilnius University Young researchers and Elite Club Mashhad Branch Islamic Azad University research Institute for Applied Physics University of Tabriz

The effects of optical field on the phenomenon of optical bistability(OB) are investigated in a K-type semiconductor double quantum well(SDQW) under various parametric conditions. It is shown that the OB threshold can be manipulated by increasing the intensity of coupling field. The dependence of the shift of OB hysteresis curve on probe wavelength detuning is then explored. In order to demonstrate controllability of the OB in this SDQW, we compare the OB features of three different configurations which could arise in this SDQW scheme, i.e., K-type, Y-type, and inverted Y-type systems. The controllability of this semiconductor nanostructure medium makes the presented OB scheme more valuable for applications in all-optical switches, information storage, and logic circuits of all optical information processing.

关键词： optical bistability semiconductor double quantum wells K-type Y-type and inverted Y-type schemes OB threshold intensity

robust H_∞ control for uncertain markovian jump systems with mixed delays

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2016年第7期25卷 108-113页

作者： r Saravanakumar m Syed Ali Department of mathematics Thiruvalluvar University

We scrutinize the problem of robust H∞control for a class of markovian jump uncertain systems with interval timevarying and distributed delays. The markovian jumping parameters are modeled as a continuous-time finite-state markov chain. The main aim is to design a delay-dependent robust H∞control synthesis which ensures the mean-square asymptotic stability of the equilibrium point. By constructing a suitable Lyapunov–Krasovskii functional（LKF）, sufficient conditions for delay-dependent robust H∞control criteria are obtained in terms of linear matrix inequalities（LmIs）. The advantage of the proposed method is illustrated by numerical examples. The results are also compared with the existing results to show the less conservativeness.

关键词： linear matrix inequality Lyapunov method markovian jumping parameters robust H∞ control