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A Neuro-Muscular Elasto-Dynamic Model of the Human Arm Part 1:Model Development

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Journal of Bionic Engineering 2009年第2期6卷 93-107页

作者： alan A.Barhorst lawrence schovanec Texas Tech University Department of Mechanical Engineering Texas Tech University Department of Mathematics and Statistics

In this paper we develop an elasto-dynamic model of the human arm for use in neuro-muscular control and dynamic interaction *** motivation for this work is to present a case for developing and using non-quasistatic models of human musculo-skeletal *** model is based on hybrid parameter multiple body system(HPMBs)variational projection *** this paper,we present an overview of the HPMBs variational principle applied to the full elasto-dynamic model of the *** generality of the model allows one to incorporate muscle effects as either loads transmitted through the tendon at points of origin and insertion or as an effective torque at a *** the technique is suitable for detailed bone and joint modeling,we present in this initial effort only simple geometry with the bones discretized as Rayleigh beams with elongation, while allowing for large *** demonstrate the viability of the mcthod for use in the companion paper and in future studies.

关键词： elasto-dynamics hybrid parameter system musculo-skeletal model neuro-muscular model

Vector-mode multiplexing brings an additional approach for capacity growth in optical fibers

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light(science & Applications) 2018年第1期7卷 1031-1033页

作者： alan E Willner Department of Electrical Engineering University of Southern CaliforniaLos AngelesCA 90089-2565USA

The paper‘Direct fiber vector eigenmode multiplexing transmission seeded by integrated optical vortex emitters’by J liu1 has successfully demonstrated that different data-carrying vector modes can be used to increase capacity through data-carrying,full-vectorial fiber eigenmode multiplexing communications in circular optical *** work uses compact,integrated optics to achieve capacity scaling by directly exploiting orthogonal spatial vector eigenmodes.

关键词： optical fiber multiplexing

Carbon pool trends and dynamics within a subtropical peatland during long-term restoration

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Ecological Processes 2017年第1期6卷 449-462页

作者： Paul Julian II stefan Gerber alan l.Wright Binhe Gu Todd Z.Osborne University of Florida Soil and Water Sciences DepartmentFt.PierceFL 34945USA. University of Florida Soil and Water Sciences DepartmentGainesvilleFL 32611USA. south Florida Water Management District Water Quality BureauWest Palm BeachFL 33406USA. University of Florida Whitney Laboratory for Marine BioscienceSt AugustineFL 32080USA.

Introduction:The Florida Everglades has undergone significant ecological change spanning the continuum of disturbance to *** the restoration effort is not complete and the ecosystem continues to experience short duration perturbations,a better understanding of long-term C dynamics of the Everglades is needed to facilitate new restoration *** study evaluated temporal trends of different aquatic carbon(C)pools of the northern Everglades Protection Area over a 20-year period to gauge historic C cycling *** inorganic C(DIC),dissolved organic C(DOC),particulate organic C(POC),and surface water carbon dioxide(pCO2(aq))were investigated between May 1,1994 and April 30,***:Annual mean concentrations of DIC,DOC,POC,and pCO2(aq)significantly decreased through time or remained constant across the Water Conservation Areas(WCAs).Overall,the magnitude of the different C pools in the water column significantly differed between *** of CO2 was dynamic across the Everglades ranging from 420 to 2001 kg CO2 year−***,the historic trend in CO2 flux from the marsh declined across our study area while pCO2(aq)largely remained somewhat constant with the exception of Water Conservation Area 2 which experienced significant declines in pCO2(aq).Particulate OC concentrations were consistent between WCAs,but a significantly decreasing trend in annual POC concentrations was ***:Hydrologic condition and nutrient inputs significantly influenced the balance,speciation,and flux of C pools across WCAs suggesting a subsidy-stress response in C dynamics relative to landscape scale responses in nutrient *** interplay between nutrient inputs and hydrologic condition exert a driving force on the balance between DIC and DOC production via the metabolism of organic matter which forms the base of the aquatic food *** the restoration trajectory as water quality and hydrology continues to improve,it is expect

关键词： Inorganic carbon Organic carbon Carbon dioxide Particulate carbon Hydrology Nutrients

A cAMP and CREB-mediated feed-forward mechanism regulates GsK3β in polycystic kidney disease

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Journal of Molecular Cell Biology 2016年第6期8卷 464-476页

作者： Vijayakumar R.Kakade shixin Tao Madhumitha Rajagopal Xia Zhou Xiaogang li alan s.l.Yu James P.Calvet Pankaj Pandey Reena Rao The Kidney Institute University of Kansas Medical CenterKansas CityKS 66160USA

Glycogen synthase kinase 3β(GsK3β),a serine/threonine protein kinase,is commonly known to be regulated at the level of its ***,in some diseases including polycystic kidney disease(PKD),GsK3βexpression is increased and plays a pathophysiological *** current studies aimed to determine the mechanism for the increased GsK3βexpression in PKD and its significance to disease *** mouse models of PKD,increases in renal GsK3βcorresponded with increases in renal cAMP levels and disease *** vivo and in vitro studies revealed that GsK3βis a cAMP-responsive gene,and elevated cAMP levels,as seen in PKD,can increase GsK3β*** normal mice,vasopressin signaling induced by water deprivation increased GsK3βexpression,which decreased following *** of the GsK3βpromoter revealed five potential binding sites for the transcription factor,cAMP response element binding protein(CREB).CREB was found to bind to GsK3βpromoter and essential for cAMP-mediated regulation of GsK3β.Importantly,this regulation was demonstrated to be part of a feedforward loop in which cAMP through CREB regulates GsK3βexpression,and GsK3βin turn positively regulates cAMP ***3βor CREB inhibition reduced transepithelial fluid secretion and cyst expansion in ***,disruption at any point of this destructive cycle may be therapeutically useful to reduce cyst expansion and preserve renal function in PKD.

关键词： GsK3β cAMP CREB in vitro cystogenesis PKD PKD1-knockout vasopressin

A versatile microfluidic device for multiple ex vivo/ in vitro tissue assays unrestrained from tissue topography

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Microsystems & Nanoengineering 2020年第1期6卷 806-819页

作者： Jose M.de Hoyos-Vega alan M.Gonzalez-suarez Jose l.Garcia-Cordero Unidad Monterrey Centro de Investigacion y de Estudios Avanzados del IPNVia del conocimiento 201Parque PIITApodacaNL 66628Mexico

Precision-cut tissue slices are an important in vitro system to study organ function because they preserve most of the native cellular microenvironments of organs,including complex intercellular ***,during sample manipulation or slicing,some of the natural surface topology and structure of these tissues is lost or ***,we introduce a microfluidic platform to perform multiple assays on the surface of a tissue section,unhindered by surface *** device consists of a valve on one side and eight open microchannels located on the opposite side,with the tissue section sandwiched between these two *** the valve is actuated,eight independent microfluidic channels are formed over a tissue *** strategy prevents cross-contamination when performing assays and enables *** irregular tissues such as an aorta,we conducted multiple in vitro and ex vivo assays on tissue sections,including short-term culturing,a drug toxicity assay,a fluorescence immunohistochemistry staining assay,and an immune cell assay,in which we observed the interaction of neutrophils with lipopolysaccharide(lPs)-stimulated *** microfluidic platform can be employed in other disciplines,such as tissue physiology and pathophysiology,morphogenesis,drug toxicity and efficiency,metabolism studies,and diagnostics,enabling the conduction of several assays with a single biopsy sample.

关键词： metabolism topography versatile

Massive energy storage systems enable secure electricity supply from renewables

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Journal of Modern Power systems and Clean Energy 2016年第4期4卷 659-667页

作者： alan J.sANGsTER school of Engineering and Physical sciences Heriot-Watt UniversityRiccarton CampusEdinburgh EH144ASUK

Climate change is mainly attributed to the burning of fossil *** solve the problem,current inhabitants have to dispense with fossil fuels as a source of *** has been demonstrated that this can be secured before 2050 by transitioning to renewable sources of *** energy storage(MEs)incorporated into long distance high voltage direct current(HVDC)transmission systems is the key technology for the *** paper describes the current state-of-the-art in electricity grid *** demonstrates how MEs,and other back-up local electricity storage schemes represent a natural way of buffering electricity consumers from the intermittency of inherent in the primary renewable ***,it can solve the base-load issues and facilitate a global transition to 100%renewable energy sources over the next fifteen to twenty years.

关键词： Electricity grid Energy storage Pumpedhydro lagoon storage Hydraulic piston Climate change

Numerical analysis and capacity evaluation of composite sprayed concrete lined tunnels

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Underground space 2018年第2期3卷 87-108页

作者： alan Bloodworth Jiang su school of Engineering University of WarwickLibrary RoadCoventry CV47ALUK Tunnels AECOMCroydonUK

spray-applied membranes for waterprooﬁng of sprayed concrete tunnels have led to the possibility of shear transfer between primary and secondary linings through the membrane interface,with the potential for reducing overall lining *** tests have shown a reasonable degree of composite action in beam *** this study,a numerical model previously calibrated against such tests is applied to a whole tunnel,considering soil–structure interaction and staged lining *** model shows composite action,and load sharing between the lining layers is expected in the tunnel as in the *** studies over the practical range of interface stiffness values show that composite action is maintained,although at high interface stiffness,excessive bending may be imposed on the secondary lining,requiring additional *** effcient composite shell design with minimal additional rein-forcement is achievable if the secondary lining thickness is reduced as compared to current *** of the system,measured in terms of the interface’s ability to transfer stress under unequal loading causing distortion on the tunnel,is found to be generally ***,adjacent construction in close proximity may provide insuffcient margin on membrane tensile de-bonding,particularly if the membrane is partially or fully saturated.

关键词： Composite sprayed concrete lining spray-applied waterproofing membrane Interface parameters lining eficiency

Altered Allogeneic Immune Responses in Middle-Aged Mice

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Cellular & Molecular Immunology 2004年第6期1卷 440-446页

作者： alan N.langnas Department of surgery University of Nebraska Medical CenterThe Lied Transplant CenterUNMCOmahaNEUSA.

It is well known that leukocyte composition,T cell phenotypes and immune function change in aged mice and ***,limited and conflicting results on the age-related immune changes in middle-aged mice were *** of the characteristics of allogeneic immune responses in aging mice may offer important information for transplantation *** major age-related changes in the immune cell phenotypes and function of 12 months old mice include:1)the significantly decreased CD4^+ cell population in the peripheral blood,the major peripheral CD4^+ cells is CD45RB^(low)CD62l^(low)memory phenotype;2)the in vitro responses to alloantigens and Con A of splenocytes markedly reduced;3)the in vivo secondary humoral immune responses to alloantigens significantly declined;4)the age-related alteration in the thymus mainly occurred in CD4/CD8 double positive(DP)stage;and 5)increased CD80^+ and MHC class II^+ cell population in ***,the major age-related immune changes in 12 months old mice occurred in CD4^+ T cells in the periphery and DP stage in the thymus,which may subsequently lead to the decreased allogeneic immune responses and the different sensitivity to immunosuppressive drugs and *** studies on the characteristics of allogeneic immunity in aging individuals may help to determine the appropriated treatment for transplant aging *** & Molecular Immunology.2004;1(6):440-446.

关键词： allogene middle-aged transplantation

large open-circuit voltage polymer solar cells by poly(3-hexylthiophene) with multi-adducts fullerenes

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science China Chemistry 2012年第5期55卷 743-748页

作者： HEEGER alan J. Department of Physics University of California Santa Barbara USA

Polymer solar cells (PsCs) made by poly(3-hexylthiophene) (P3HT) with multi-adducts fullerenes, [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), PC61BM-bisadduct (bisPC61BM) and PC61BM-trisadduct (trisPC61BM), were reported. Electrochemistry studies indicated that PC61BM, bisPC61BM and trisPC61BM had step-up distributional lowest unoccupied molecular orbital (lUMO) energy. PsCs made by P3HT with above PC61BMs show a trend of enlarged open-circuit voltages, which is in good agreement with the energy difference between the lUMO of PC61BMs and the HOMO of P3HT. On the contrary, reduced short-circuit currents (Jsc) were observed. The investigation of photo responsibility, dynamics analysis based on photo-induced absorption of composite films, P3HT:PC61BMs and n-channel thin film field-effect transistors of PC61BMs suggested that the short polaron lifetimes and low carrier mobilities were response for reduced Jsc. All these results demonstrated that it was important to develop an electron acceptor which has both high carrier mobility, and good compatibility with the electron donor conjugated polymer for approaching high performance PsCs.

关键词： fullerene derivative large open circuit voltage polaron lifetime charge carrier mobility