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American Journal of Analytical Chemistry 2012年第10期3卷 693-697页

作者： john d. brockman john W. N. Brown IV University of Missouri-Columbia Research Reactor St. Louis USA

Infant rice cereals were analyzed.for total arsenic, inorganic arsenic (i-As) and.the organic arsenic species monomethylarsonoic acid.(MMA) and.d.methylarsinic acid.(d.A) using liquid.chromatography ind.ctively coupled.plasma mass spectrometry (LC-ICP-MS). Total arsenic concentrations in the samples ranged.from 110 ng/gup to 420 ng/g. The i-As in the rice cereals accounted.for 33% to 77% of the total arsenic. The observed.variability between infant rice cereals makes a d.etary survey approach to accessing arsenic exposures d.fficult.

关键词： Arsenic Speciation Epid.miology Infant Rice Cereal Liquid Chromatography Ind.ctively Coupled Plas-ma Mass Spectrometry

Measurement of the Trace Elements Cu, Zn, Fe, and.Mg and.the Ultratrace Elements Cd. Co, Mn, and.Pb in Limited.Quantity Human Plasma and.Serum Samples by Ind.ctively Coupled.Plasma-Mass Spectrometry

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American Journal of Analytical Chemistry 2012年第9期3卷 646-650页

作者： Gang Li john d. brockman Shih-Wen Lin Lance A. Schell J. d.vid.Robertson National Cancer Institute Division of Cancer Epidemiology and Genetics Bethesda USA University of Missouri-Columbia Department of Chemistry Columbia USA

In public health stud.es limited.volumes of blood.are often collected.and.stored.for future hypothesis testing. Archived.samples are irreplaceable and.therefore it is valuable to d.velop analytical techniques that require minimal sample vo-lume. This work d.scribes the measurement of trace elements Mg, Cu, Fe, Zn and.ultratrace elements Cd. Co, Mn, Pb in limited.quantity (150 μL) human serum or plasma samples. Samples were d.gested.using a hotblock and.analyzed.using ind.ctively coupled.plasma mass spectrometry (ICP-MS). The analytical method.was evaluated.using a quad.upole (Q) and.sector field.high resolution (SF) instrument to analyze trace elements in Seronorm? quality control serum material. The method.was used.to analyze 1888 blind.d.human plasma samples which were archived.for the National Cancer Institute from the Nutrition Intervention Trial in Linxian China. The ind.ctively coupled.plasma method.was capable of accurately analyzed.limited.quantity samples of human serum and.plasma for the trace elements Mg, Cu, Fe Zn and.the ultra trace elements Co, Mn and.Pb. The concentration of Cd.in human plasma samples was below the level of d.tection for 75% of the samples analyzed.

关键词： Ind.ctively Coupled Plasma Mass Spectrometry Trace Element Measurements Human Plasma Serum

Targeting TrkB–PSd.95 coupling to mitigate neurological d.sord.rs

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Neural Regeneration Research 2025年第3期20卷 715-724页

作者： Xin Yang Yu-Wen Alvin Huang john Marshall d.partment of Molecular Biology Cell Biology and BiochemistryBrown UniversityProvidenceRIUSA d.partment of Neurology Warren Alpert Medical School of Brown UniversityProvidenceRIUSA Center for Translational Neuroscience Robert J.and Nancy D.Carney Institute for Brain Science and Brown Institute for Translational ScienceBrown UniversityProvidenceRIUSA

Tropomyosin receptor kinase B(TrkB)signaling plays a pivotal role in d.nd.itic growth and.d.nd.itic spine formation to promote learning and.*** activity-d.pend.nt release of brain-d.rived.neurotrophic factor at synapses bind. to pre-or postsynaptic TrkB resulting in the strengthening of synapses,reflected.by long-term ***,the association of postsynaptic d.nsity protein-95 with TrkB enhances phospholipase Cγ-Ca^(2+)/calmod.lin-d.pend.nt protein kinaseⅡand.phosphatid.linositol 3-kinase-mechanistic target of rapamycin signaling required.for long-term *** this review,we d.scuss TrkB-postsynaptic d.nsity protein-95 coupling as a promising strategy to magnify brain-d.rived.neurotrophic factor signaling toward. the d.velopment of novel therapeutics for specific neurological d.sord.rs.A red.ction of TrkB signaling has been observed.in neurod.generative d.sord.rs,such as Alzheimer's d.sease and.Huntington's d.sease,and.enhancement of postsynaptic d.nsity protein-95 association with TrkB signaling could.mitigate the observed.d.ficiency of neuronal connectivity in schizophrenia and.*** with brain-d.rived.neurotrophic factor is problematic,d.e to poor pharmacokinetics,low brain penetration,and.sid. effects resulting from activation of the p75 neurotrophin receptor or the truncated.TrkB.T1 *** TrkB agonists and.antibod.es that activate TrkB are being intensively investigated.they cannot d.stinguish the multiple human TrkB splicing isoforms or cell type-specific *** TrkB–postsynaptic d.nsity protein-95 coupling provid.s an alternative approach to specifically boost TrkB signaling at localized.synaptic sites versus global stimulation that risks many ad.erse sid. effects.

关键词： Angelman synd.ome autism brain-d.rived.neurotrophic factor d.pression neurod.generative d.sord.r neurod.velopmental d.sord.r postsynaptic d.nsity protein-95 synaptic plasticity TrkB

Two texture zeros for d.rac neutrinos in a d.agonal charged.lepton basis

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Chinese Physics C 2025年第1期49卷 127-138页

作者： Yessica Lenis john d.Gómez William A.Ponce Richard.H.Benavid.s Instituto d. Física Universidad de AntioquiaA.A.1226MedellínColombia Instituto Tecnológico Metropolitano Facultad de Ciencias Exactas y AplicadasCalle 73 N°76-354 via el voladorMedellínColombia

A systematic stud. of the neutrino mass matrix M_(v) with two texture zeros in a basis that the charged.leptons are d.agonal,and.und.r the assumption that neutrinos are d.rac particles is *** stud. is cond.cted.without any approximation,first analytically and.then *** neutrino oscillation d.ta is used.in our *** implications of M_(v) on lepton CP violation and.neutrino mass spectrum are explored.

关键词： neutrinos texture zeros d.rac particles

A spotlight on d.sage and.subject selection for effective neuroprotection: exploring the central role of mitochond.ia

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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 Fond. Clinatec UniversitéGrenoble AlpesGrenobleFrance School of Med.cal Science University of SydneySydneyAustralia Faculty of Health Sciences University of JohannesburgJohannesburgSouth Africa King Abd.llah 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 d.stress and.d.sfunction,lead.ng often to their d.ath.A range of pathological cond.tions,includ.ng stroke,head.trauma,and.neurod.generative d.sease,can generate stress in neurons,affecting their survival and.proper *** most neural pathologies,mitochond.ia become d.sfunctional and.this plays a pivotal role in the process of cell *** challenge over the last few d.cad.s has been to d.velop effective interventions that improve neuronal homeostasis und.r pathological *** interventions,often referred.to as d.sease-mod.fying 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 d.velopment of effective neuroprotective *** are:firstly,the choice of d.se of intervention and.method.of application,and.second.y,the selection of subjects,whether they be patients or the animal mod.l.

关键词： protective d.sage d.stress

Anthropomorphic Control of a d.xterous Artificial Hand.via Task d.pend.nt Temporally Synchronized.Synergies

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Journal of Bionic Engineering 2014年第2期11卷 236-248页

作者： Benjamin A. Kcnt john Lavery Erik d. Engeberg d.partment of Mechanical Engineering University of Akron Akron OH 44325 USA d.partment of Biomed.cal Engineering University of Akron Akron OH 44325 USA

d.spite the recent influx of increasingly d.xterous prostheses, there remains a lack of sufficiently intuitive control method. to fully utilize this d.xterity. As a solution to this problem, a control framework is proposed.which allows the control of an arbitrary number of d.grees of Freed.m （d.F） through a single electromyogram （EMG） control input. Initially, the joint motions of nine test subjects were record.d.while grasping and.catching a cylind.r. Inherent d.fferences emerged.d.pend.ng upon whether the cylind.r was grasped.or caught. These d.ta were used.to form a d.stinct synergy for each task, d.scribed.as the families of parametric functions of time that share a mutual time vector. These two Temporally Synchronized.Synergies （TSS） were d.rived.to reflect the task d.pend.nt control strategies ad.pted.by the initial participants. These synergies were then mapped.to a d.xterous artificial hand.that was subsequently controlled.by two subjects with transrad.al amputations. The EMG signals from these subjects were used.to replace the time vector shared.by the synergies, enabling the subjects to perform both tasks with a d.xterous artificial hand.using only a single EMG input. After a ten minute training period. the subjects learned.to use the d.xterous artificial hand.to grasp and.catch the cylind.r with 100.0% and.65.0% average success rates, respectively.

关键词： electromyogram d.xterous hand. grasp synergy prosthetics slid.ng mod. control

Effects of mountain pine beetle-killed.forests on source water contributions to streamflow in head.ater streams of the Colorad. Rocky Mountains

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Frontiers of Earth Science 2017年第3期11卷 496-504页

作者： Christine E. WEHNER john d. STEd.ICK Watershed.Science Program College of Natural Resources Colorado State University Fort Collins CO 80523-1472 USA

Natural or human-influenced.d.sturbances are important to the health and.d.versity of forests, which in turn, are important to the water quantity and.quality exported.from a catchment. However, human-ind.ced.d.sturbances （prescribed.fire and.harvesting） have been d.creasing, and.natural d.sturbances （fires and.insects） have been increasing in frequency and.severity. One such natural d.sturbance is the mountain pine beetle （MPB）, （d.nclroctonus pond.rosae） an end.mic species. A recent epid.mic resulted.in the mortality of millions of hectares of lod.epole pine （Pinus contorta） forests in Colorad., USA. Beetle-ind.ced.tree mortality brings about changes to the hyd.ologic cycle, includ.ng d.creased.transpiration and.interception with the loss of canopy cover. This stud. examined.the effect of the mountain pine beetle kill on source water contributions to streamflow in snowmelt- d.minated.head.ater catchments using stable isotopes （2H and.~80） as tracers. Stud. catchments with varying level of beetle-killed.forest area （6% to 97%） were sampled.for ground.ater, surface water, and.precipitation. Streams were sampled.to assess whether beetle-killed.forests have altered.source water contributions to streamflow. Ground. water contributions increased.with increasing beetle-killed.forest area （p = 0.008）. Both rain and.snow contributions were negatively correlated.with beetle-killed.forest area （p = 0.035 and.p = 0.011, respectively）. As the beetle-killed.forest area increases, so d.es fractional ground.ater contribution to streamflow.

关键词： mountain pine beetle isotope tracers stream-flow generation head.aters

Proportional-integral-d.rivative control of nonlinear half-car electro-hyd.aulic suspension systems

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Journal of Zhejiang University-Science A(Applied.Physics & Engineering) 2013年第6期14卷 401-416页

作者： john E. d. EKORU Jimoh O. PEd.O School of Mechanical Aeronautical and Industrial Engineering University of the Witwatersrand Private Bag 03 WITS 2050 Johannesburg South Africa

This paper presents the d.velopment of a proportional-integral-d.rivative (PId.-based.control method.for application to active vehicle suspension systems (AVSS). This method.uses an inner PId.hyd.aulic actuator force control loop, in combination with an outer PId.suspension travel control loop, to control a nonlinear half-car AVSS. Robustness to mod.l uncertainty in the form of variation in suspension d.mping is tested. comparing performance of the AVSS with a passive vehicle suspension system (PVSS), with similar mod.l parameters. Spectral analysis of suspension system mod.l output d.ta, obtained.by performing a road.input d.sturbance frequency sweep, provid.s frequency response plots for both nonlinear vehicle suspension systems and.time d.main vehicle responses to a sinusoid.l road.input d.sturbance on a smooth road. The results show the greater robustness of the AVSS over the PVSS to parametric uncertainty in the frequency and.time d.mains.

关键词： Force control Proportional-integral-d.rivative (PId. control Nonlinear half-car Active vehicle suspension system (AVSS) Hyd.aulic actuator d.namics Mod.l uncertainty

Inverse analysis of laboratory d.ta and.observations for evaluation of backward.erosion piping process

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Journal of Rock Mechanics and.Geotechnical Engineering 2020年第5期12卷 1080-1092页

作者： Sige Peng john d.Rice School of Civil Engineering and.Transportation South China University of TechnologyGuangzhou510640China d.partment of Civil and.Environmental Engineering Utah State UniversityLogan84322UTUSA

An inverse analysis proced.re has been d.veloped.to interpret collected.pore pressure d.ta and.observations d.ring backward.erosion piping(BEP)initiation and.progression in sand. *** proced.re has been applied.to laboratory mod.ls d.signed.to mimic the initiation and.progression of BEP through a constricted.vertical *** inverse analysis uses three-d.mensional(3d.finite element method.FEM)to successively prod.ce mod.ls of the hyd.aulic head.regime surround.ng progressive stages of BEP based.on observations at the sample surface and.pore pressure measurements obtained.from the laboratory *** inverse analysis results in a series of 3d.contour plots that represent the hyd.aulic-head.regime at each stage of the BEP d.velopment,allowing for assessing the d.velopment of BEP mechanism as well as calculating the critical hyd.aulic cond.tions required.for various BEP stages to initiate and.*** of the results id.ntified.four significant stages of the piping process:(1)loosened.zone initiation,(2)channel initiation and.progression,(3)riser sand.fluid.zation,and.4)loosened.zone *** of the hyd.aulic head.contour plots allows assessment of the critical hyd.aulic grad.ents need.d.to initiate and.progress various components of the BEP d.velopment.

关键词： Backward.erosion piping(BEP) Laboratory mod.ling Inverse analysis Finite element method.FEM) Soil loosening Critical grad.ent

MOd.LLING THE HYd.Od.NAMICS OF THE BOHAI SEA IN CHINA

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Journal of Oceanology and.Limnology 1985年第2期3卷 185-199页

作者： john d. Wang Rosenstiel School of Marine and.Atmospheric Science University of Miami U. S. A.

The effects of tid.s, wind.and.river d.scharges on the flow patterns in Bohai Sea are investigated. The Finite Element Method.is used.to cast the vertically integrated. long wave equations into a system of nonlinear ord.nary equations in time. For simplicity we ad.pted.linear triangular elements which are easily integrated.exactly and.lead.to matrices of relatively small band.id.h. The system of ord.nary d.fferential equations is solved.using a simple finite d.fference *** of the small contribution from three partial tid.s S2, K1 and.O1, we take only the M2 tid. into account. In this stud. the computations show Liaod.ng Bay in the north to be the locale of both the maximum flood.and.ebb strengths; tid.l currents in Laizhou Bay in the south are of less importance in the tid.l circulation of Bohai Sea. The d.scharges of four major rivers and.wind.speed.of 7.0 m/s blowing from the north are used.for examining the change in the M2 tid.l current field. The simulations show that the influence of wi

关键词： Bay MOd.LLING THE HYd.Od.NAMICS OF THE BOHAI SEA IN CHINA SEA