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Engineered Regeneration 2024年第2期5卷 269-281页

作者： Greg Sacks Vincent DeStefano Claire parker Ryan Lebens Harry Mushlin Renaissance School of Medicine at Stony Brook University Stony BrookNYUSA

Nucleus Pulposus(NP)Replacement is a developing surgical methodology for the treatment of pathology related to degeneration of intervertebral discs(IVDs).This article provides necessary context regarding the patholo-gies treated with this technology,the biomechanical structure and function of the IVD,and the procedures this technology aims to ***,it provides an overview and discussion of commercial and experimental preformed and in situ curing prosthesis designs reported in the scientific literature and summarizes the results of biomechanical and clinical studies evaluating their *** and updated information on the most recent research into NP replacement with novel hydrogel and tissue engineering(TE)strategies is *** of the NP allows for potential improvement in the treatment of degenerative spinal pathologies through minimally invasive surgical techniques.

关键词： Nucleus Pulposus Intradiscal Prosthesis Hydrogel Artificial Disc Implant Spine Surgery

Solar Activity and Classical Physics

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Chinese Journal of Astronomy and Astrophysics 2001年第2期1卷 99-124页

作者： E. N. parker (Department of Physics, University of Chicago, Chicago, IL 60637) Department of Physics University of Chicago Chicago IL 60637

This review of solar physics emphasizes several of the more conspicuous scientific puzzles posed by contemporary observational knowledge of the magnetic activity of the Sun. The puzzles emphasize how much classical physics we have yet to learn from the Sun. The physics of solar activity is based on the principles of Newton, Maxwell, Lorentz, Boltzmann, et. al., along with the principles of radiative transfer. In the large, these principles are expressed by magnetohydro dynamics. A brief derivation of the magnetohydrodynamic induction and moment um equations is provided, with a discussion of popular misconceptions.

关键词： Sun: activety - Magnetohydro dynamics - radiative transfer

Translational genomics in cancer research: converting profiles into personalized cancer medicine

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Cancer Biology & Medicine 2013年第4期10卷 214-220页

作者： Lalit Patel Brittany parker Da Yang Wei Zhang Department of Pathology The University of Texas MD Anderson Cancer Center The University of Texas Graduate School of Biomedical Sciences

Cancer genomics is a rapidly growing discipline in which the genetic molecular basis of malignancy is studied at the scale of whole *** the discipline has been successful with respect to identifying specific oncogenes and tumor suppressors involved in oncogenesis,it is also challenging our approach to managing patients suffering from this deadly *** cancer genomics is driving clinical oncology to take a more molecular approach to diagnosis,prognostication,and treatment *** review here recent work undertaken in cancer genomics with an emphasis on translation of genomic ***,we discuss scientific challenges and research opportunities emerging from findings derived through analysis of tumors with high-depth sequencing.

关键词： Cancer genomics translation personalized medicine

Atmospheric and kinetic studies of OH and HO_2 by the FAGE technique

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Journal of Environmental Sciences 2012年第1期24卷 78-86页

作者： D.Amedro K.Miyazaki A.parker C.Schoemaecker C.Fittschen Laboratoire PC2A Universit de Lille 1- Ba timent C1159655 Villeneuve d'AscqFrance Department of Applied Chemistry Tokyo Metropolitan UniversityJapan

A new FAGE setup has recently been built at the University of Lille,*** permits the quantification of OH and HO 2 in the atmosphere with a detection limit of 3×10 5 molecules/（cm 3 ·min） for OH and 1×10 6 molecules/（cm 3 ·min） for HO *** coupling to a photolysis cell enables the measurement of the total reactivity of the hydroxyl radical in ambient air and kinetic studies in *** configurations have been considered：one with the photolysis cell at 90° to the FAGE nozzle,the other on line with the FAGE *** two configurations have been tested and validated by measuring the well known rate constants of OH with CH 4,C 3 H 8 and *** advantages and drawbacks of each configuration have been *** ＂on line＂ configuration limits losses and permits measurements over a larger reactivity range but is affected by OH formation from the laser beam striking the FAGE nozzle,thus limiting the ability to carry out energy dependence studies which can,in contrast,be successfully performed in the 90° configuration.

关键词： OH kinetic reactivity laser induced fluorescence

Chemistry of sediments from the Dobczyce Reservoir,Poland,and the environmental implications

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International Journal of Sediment Research 2010年第1期25卷 28-38页

作者： Witold RECZYNSKI Malgorzata JAKUBOWSKA Janusz GOLAS Andrew parker Barbara KUBICA University of Science and Technology University of Reading Institute of Nuclear Physics

Sediments samples of the Dobczyce Reservoir(South Poland) were taken in three successive years(2004-06) at 17 points,analyzed for 12 elements by atomic absorption *** variations in elemental composition due to hydrological and environmental reasons were *** use of statistical and chemometric tools enabled objective and effective analysis of the data obtained,both in case of long term observations as well as in terms of interpretation of incidental changes in metal *** proposed methodology can be useful in:a) dividing monitored territories(lakes,rivers,catchments) into similar and dissimilar areas;b) distinguishing between typical and non-typical contaminants distribution;c) reducing the number of essential analytes and sampling points that should be controlled in the future,without loss of important environmental information.

关键词： Dobczyce Reservoir Sediments Metals CA PCA

On the use of residual dipolar couplings in multi-state structure calculation of two-domain proteins

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Magnetic Resonance Letters 2022年第2期2卷 61-68,I0002页

作者： Alexandra Born Morkos A.Henen parker J.Nichols Beat Vogeli University of Colorado Anschutz Medical Campus Department of Biochemistry and Molecular Genetics12801 East 17th AvenueAuroraCO80045USA Faculty of Pharmacy Mansoura UniversityMansoura35516Egypt

Residual dipolar couplings(RDCs)are powerful nuclear magnetic resonance(NMR)probes for the structure calculation of ***,an alignment tensor that defines the orientation of the entire molecule relative to the magnetic field is determined either before refinement of individual bond vectors or simultaneously with this *** single-domain proteins this approach works well since all bond vectors can be described within the same coordinate frame,which is given by the alignment ***,novel approaches are sought after for systems where no universal alignment tensor can be ***,we present an approach that can be applied to two-domain proteins that enables the calculation of multiple states within each domain as well as with respect to the relative positions of the two domains.

关键词： RDC Residual dipolar coupling Two-domain protein Multi-state structure

The Impact of Exchange Rate on Economic Growth in Central Africa

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The Impact of Exchange Rate on Economic Growth in Central Af...

作者： Sosso Ngando Nelson parker 浙江工商大学

学位级别：硕士

20世纪90年代以来,非洲国家经济逐步复苏,实现了快速增长。其中,中非经济增长相对显著。中非经济增长的主要原因可分为外部环境和内部因素的多个方面,包括战争和冲突的持续减少和政治稳定的显著增加。各国实施的宏观经济改革措施增强了... 详细信息

20世纪90年代以来,非洲国家经济逐步复苏,实现了快速增长。其中,中非经济增长相对显著。中非经济增长的主要原因可分为外部环境和内部因素的多个方面,包括战争和冲突的持续减少和政治稳定的显著增加。各国实施的宏观经济改革措施增强了中非经济的增长潜力,国际市场上商品成本和资本流入量的上升,有力地证明了中非国家的贸易和融资条件。由于不同的初始条件,中非国家在经济转型过程中面临的困难将大于其他国家。本文从重要经济体和货币市场两个维度出发,总结了影响中非国家经济的汇率波动途径,包括贸易规模效应、资本流动效应和货币稳定效应。利用2000-2016年中非主要经济体月度面板数据,采用TGARCH模型测算汇率波动性指标,采用PVAR模型实证检验汇率波动对中非经济的影响。研究发现,利率波动促进了资本流动,但它绝对不是国际贸易事件的附属因素。它在一定程度上加剧了货币市场的动荡,这不是中非经济事件的附庸,阻碍了中非经济的复苏。在此基础上,本文提出了相应的对策。

关键词：中非汇率经济增长

Dendroclimatic analysis of white pine (Pinus strobus L.)using long-term provenance test sites across eastern North America

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Forest Ecosystems 2018年第3期5卷 221-235页

作者： Sophan Chhin Ronald S.Zalesny Jr William C.parker John Brissette Division of Forestry and Natural Resources West Virginia University322 Percival HallPO Box 6125MorgantownWV26506USA USDA Forest Service Northern Research Station5985Highway KRhinelanderWI 54501USA Ontario Forest Research Institute 1235Queen St.ESault Ste.MarieON P6A 2E5Canada USDA Forest Service Northern Research Station271Mast RoadDurhamNH 03824USA

Background: The main objective of this study was to examine the climatic sensitivity of the radial growth response of 13 eastern white pine(Pinus strobus L.) provenances planted at seven test sites throughout the northern part of the species’ native distribution in eastern North ***: The test sites(i.e., Wabeno, Wisconsin, USA; Manistique, Michigan, USA; Pine River, Michigan, USA; Newaygo,Michigan, USA; Turkey Point, Ontario, Canada; Ganaraska, Ontario, Canada; and Orono, Maine, USA) examined in this study were part of a range-wide white pine provenance trial established in the early 1960 s in the eastern United States and Canada. Principal components analysis(PCA) was used to examine the main modes of variation [first(PC1) and second(PC2) principal component axes] in the standardized radial growth indices of the provenances at each test *** year scores for PC1 and PC2 were examined in relation to an array of test site climate variables using multiple regression analysis to examine the commonality of growth response across all provenances to the climate of each test site. Provenance loadings on PC1 and PC2 were correlated with geographic parameters(i.e., latitude, longitude,elevation) and a suite of biophysical parameters associated with provenance origin ***: The amount of variation in radial growth explained by PC1 and PC2 ranged from 43.4% to 89.6%. Dendroclimatic models revealed that white pine radial growth responses to climate were complex and differed among sites. The key dendroclimatic relationships observed included sensitivity to high temperature in winter and summer, cold temperature in the spring and fal(i.e., beginning and end of the growing season), summer moisture stress, potential sensitivity to storminduced damage in spring and fal, and both positive and negative effects of higher winter snowfal. Separation of the loadings of provenances on principal component axes was mainly associated with temperature-related bioclima

关键词： Adaptation Climate change Dendrochronology Seed source

Numerical Analysis of Tilted Cutting and F128 Brushes

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Computer Modeling in Engineering & Sciences 2019年第10期121卷 23-47页

作者： Libardo V.Vanegas-Useche Magd M.Abdel-Wahab Graham A.parker Facultad de Ingeniería Mecánica Universidad Tecnológica de PereiraLa JulitaPereira 660003Colombia Division of Computational Mechanics Ton Duc Thang UniversityHo Chi Minh CityViet Nam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityViet Nam Soete Laboratory Faculty of Engineering and ArchitectureGhent UniversityTechnologiepark Zwijnaarde 46B-9052 ZwijnaardeBelgium Faculty of Engineering and Physical Sciences University of Surrey.Guildford GU27XHUK.

Road sweeping is an essential service that has to be conducted for public health,as well as aesthetic *** many countries,sweeping vehicles are used for this *** usually comprise a gutter brush that sweeps the debris that is located in the road *** work studies the performance of two kinds of gutter brushes:a cutting brush and a flicking(F128)*** is carried out by means of a 3-D dynamic,nonlinear Finite Element(FE)brush model developed by the *** this model,inertia forces are applied to the bristle,and its clamped end is ***,the surface(road)is rotated,translated,and ***-road interaction is modelled as flexible-to-rigid *** particular,the aim of this article is to compare the performance of a conventional brush and a brush rotating at variable *** brushes normally work tilted,FE analyses are carried out for tilted cutting and F128 brushes,rotating at speeds that fluctuate at different *** is concluded that brush oscillations have a significant effect on bristle tip velocities and bristle-road ***,at certain frequencies,oscillations seem to improve sweeping performance of the F128 ***,they do not appear to improve significantly the performance of the cutting brush.

关键词： Gutter brushes cutting brush flicking brush FEM variable speed brushing

Determination of the Normal Contact Stiffness and Integration Time Step for the Finite Element Modeling of Bristle-Surface Interaction

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Computers, Materials & Continua 2018年第7期56卷 169-184页

作者： Libardo V.Vanegas-Useche Magd M.Abdel-Wahab Graham A.parker Facultad de Ingeniería Mecánica Universidad Tecnológica de Pereira.Pereira 660003Colombia Division of Computational Mechanics Ton Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityVietnam Soete Laboratory Faculty of Engineering and ArchitectureGhent UniversityTechnologiepark Zwijnaarde 903Zwijnaarde B-9052Belgium Faculty of Engineering and Physical Sciences University of Surrey.GuildfordUK

In finite element modeling of impact,it is necessary to define appropriate values of the normal contact stiffness,Kn,and the Integration Time Step(ITS).Because impacts are usually of very short duration,very small ITSs are ***,the selection of a suitable value of Kn is a critical issue,as the impact behavior depends dramatically on this *** this work,a number of experimental tests and finite element analyses have been performed in order to obtain an appropriate value of Kn for the interaction between a bristle of a gutter brush for road sweeping and a concrete ***,a suitable ITS is *** experiments consist of releasing a steel bristle that is placed vertically at a certain distance from a concrete surface and tracking the ***,in the finite element analyses,a beam is modeled in free fall and impacting a surface;contact and target elements are attached to the beam and the surface,*** results of the experiments and the modeling are integrated through the principle of conservation of energy,the principle of linear impulse and momentum,and Newton’s second *** results demonstrate that,for the case studied,Kn and the impact time tend to be independent of the velocity just before impact and that Kn has a very large variation,as concrete is a composite material with a rough ***,the ratio between the largest height of the bristle after impact and the initial height tends to be constant.

关键词： Brush street sweeping finite element modeling contact mechanics