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ABCD^(2) risk score does not predict the presence of cerebral microemboli in patients with hyper-acute symptomatic critical carotid artery stenosis

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Stroke & Vascular Neurology 2017年第2期2卷 41-46页

作者： Mahmud Saedon Charles E Hutchinson Christopher H E Imray donald r j singer Warwick Medical School University of WarwickCoventryUK University Hospitals Coventry Warwickshire NHS Trust CoventryUK Fellowship of Postgraduate Medicine LondonUK Yale School of Medicine New HavenConnecticutUSA

Introduction:ABCD^(2) risk score and cerebral microemboli detected by transcranial Doppler(TCD)have been separately shown to the predict risk of recurrent acute *** studied whether ABCD2 risk score predicts cerebral microemboli in patients with hyper-acute symptomatic carotid artery *** and methods:We studied 206 patients presenting within 2 weeks of transient ischaemic attack or minor stroke and found to have critical carotid artery stenosis(≥50% ).86 patients(age 70±1(SEM:years),58 men,83 Caucasian)had evidence of microemboli;72(84% )of these underwent carotid endarterectomy(CEA).120 patients(age 72±1 years,91 men,113 Caucasian)did not have microemboli detected;102(85% )of these underwent *** were analysed using X2 and Mann–Whitney U tests and receiver operating characteristic(rOC)***:140/206(68% :95% CI 61.63 to 74.37)patients with hyper-acute symptomatic critical carotid stenosis had an ABCD2 risk score≥*** was no significant difference in the NICE red flag criterion for early assessment(ABCD^(2) risk score≥4)for patients with cerebral microemboli versus those without microemboli(59/86 vs 81/120 patients:Or 1.05 ABCD2 risk score≥4(95% CI 0.58 to 1.90,p=0.867)).The ABCD2 risk score wasrebral *** adjusting for pre-neurological event antiplatelet treatment(APT),area under the curve(AUC)of rOC for ABCD2 risk score showed no prediction of cerebral microemboli(no pre-event APT,n=57:AUC 0.45(95% CI 0.29 to 0.60,p=0.531);preevent APT,n=147:AUC 0.51(95% CI 0.42 to 0.60,p=0.804)).Conclusions:The ABCD2 score did not predict the presence of cerebral microemboli or carotid disease in over one-quarter of patients with symptomatic critical carotid artery *** the basis of NICE guidelines(refer early if ABCD2≥4),assessment of high stroke risk based on ABCD2 scoring may lead to inappropriate delay in urgent treat

关键词： patients cerebral emboli

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registry report on prediction by Pocock cardiovascular score of cerebral microemboli acutely following carotid endarterectomy

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Stroke & Vascular Neurology 2018年第3期3卷 147-152页

作者： Mahmud Saedon Athanasios Saratzis rachel W S Lee Charles E Hutchinson Christopher H E Imray donald r j singer Nottingham University Hospitals NHS Trust NottinghamUK University Hospitals Coventry and Warwickshire NHS Trust CoventryUK Leicester royal Infirmary LeicesterUK Yale School of Medicine New HavenConnecticutUSA Fellowship of Postgraduate Medicine LondonUK

background Cerebral microemboli may lead to ischaemic neurological complications after carotid endarterectomy(CEA).The association between classical cardiovascular risk factors and acute cerebral microemboli following carotid surgery has not been *** aim of this study was to explore whether an established cardiovascular risk score(Pocock score)predicts the presence of cerebral microemboli acutely after *** and methods Pocock scores were assessed for the 670 patients from the Carotid Surgery registry(age 71±1(SEM)years,474(71%)male,652(97%)Caucasian)managed from january 2002 to December 2012 in the regional Vascular Centre at University Hospitals Coventry and Warwickshire NHS Trust,which serves a population of *** was undertaken in 474(71%)patients for symptomatic carotid stenosis and in 196(25%)asymptomatic patients during the same period.74% of patients were hypertensive,71%were smokers and 49% had *** A high Pocock score(≥2.3%)was significantly associated with evidence of cerebral microemboli acutely following CEA(P=0.039,Mann-Whitney(MW)test).A Pocock score(≥2.3%)did not predict patients who required additional antiplatelet therapy(microemboli signal(MES)rate>50 hour-1:P=0.164,MW test).receiver operating characteristic analysis also showed that the Pocock score predicts acute postoperative microemboli(area under the curve(AUC)0.546,95%CI 0.502 to 0.590,P=0.039)but not a high rate of postoperative microemboli(MES>50 hour−1:AUC 0.546,95% CI 0.482 to 0.610,P=0.164).A Pocock score≥2.3% showed a sensitivity of 74% for the presence of acute postoperative cerebral microemboli.A Pocock score≥2.3% also showed a sensitivity of 77% and a negative predictive value of 90% for patients who developed a high microembolic rate>50 hour−1 after carotid *** These findings demonstrate that the Pocock score could be used as a clinical tool to identify patients at high risk of developing acute postoperative microemboli.

关键词： cerebral Surgery registry

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Mathematical modelling of ball and plate system with experimental and correlation function-based model validation

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Control Theory and Technology 2024年第2期22卷 326-341页

作者： T.r.Dil Kumar S.j.Mija Department of Electrical Engineering National Institute of Technology CalicutKozhikode673601KeralaIndia

The ball and plate system is an inherently nonlinear under actuated benchmark system used for validating the performance of various control schemes. A mathematical model depicting the dynamics close to that of the system is very much required for such a test bed. In this correspondence, the complete nonlinear model, a simplified nonlinear model, and a linearized model of the ball and plate system are developed. The system comprises a ball and plate mechanism and a rotary servo unit. The ball and plate mechanism is modelled using the Euler–Lagrange method, whereas the rotary servo subsystem is modelled from the first principles. The nonlinear model of the combined system is developed by including the dynamics of the servo motor with gear and rolling resistance between the ball and the plate. The simplified nonlinear model of the system is obtained with suitable assumptions. The model is linearized around the operating point using the jacobian. The validity of the developed models is investigated through correlation function analysis. The open-loop response of the three models, viz., nonlinear, simplified nonlinear, and linearized models, is analyzed in the MATLAB/Simulink platform. Since the open-loop system is unstable, the experimental validation of the model is performed with a double-loop PSO (particle swarm optimization) PID control scheme.

关键词： Ball and plate system Correlation function Model validation Particle swarm optimization(PSO) PSO PID controller

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On an isotropic porous solid cylinder:the analytical solution and sensitivity analysis of the pressure

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Applied Mathematics and Mechanics(English Edition) 2024年第9期45卷 1499-1522页

作者： H.ASGHArI L.MILLEr r.PENTA j.MErODIO Departamento de Matematica Aplicada a las TIC ETS de Ingenieria de Sistemas InformaticosUniversidad Politecnica de MadridMadrid 28031Spain School of Mathematics and Statistics University of GlasgowGlasgow G128QQU.K.

Within this work,we perform a sensitivity analysis to determine the influence of the material input parameters on the pressure in an isotropic porous solid *** provide a step-by-step guide to obtain the analytical solution for a porous isotropic elastic cylinder in terms of the pressure,stresses,and elastic *** obtain the solution by performing a Laplace transform on the governing equations,which are those of Biot's poroelasticity in cylindrical polar *** enforce radial boundary conditions and obtain the solution in the Laplace transformed domain before reverting back to the time *** sensitivity analysis is then carried out,considering only the derived pressure *** analysis finds that the time t,Biot's modulus M,and Poisson's ratio ν have the highest influence on the pressure whereas the initial value of pressure P_(0) plays a very little role.

关键词： sensitivity analysis Laplace transform cylindrical polar coordinate Biot's modulus cylinder

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Stable diffusion gradients in microfluidic conduits bounded by fluid walls

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Microsystems & Nanoengineering 2024年第3期10卷 357-367页

作者： Federico Nebuloni Cyril Deroy Peter r.Cook Edmond j.Walsh Department of Engineering Science Osney Thermo-Fluids InstituteUniversity of OxfordOxford OX20ESUK Sir William Dunn School of Pathology University of OxfordOxford OX13REUK

Assays mimicking in vitro the concentration gradients triggering biological responses like those involved in fighting infections and blood clotting are essential for biomedical *** assays prove especially attractive as they allow precise control of gradient shape allied to a reduction in *** microfluidic devices are fabricated using solid plastics that prevent direct access to responding ***-walled microfluidics allows the manufacture of circuits on standard Petri dishes in seconds,coupled to simple operating methods;cell-culture medium sitting in a standard dish is confined to circuits by fluid walls made of an immiscible *** develop and experimentally validate an analytical model of diffusion between two or more aqueous streams flowing at different rates into a fluid-walled conduit with the cross-section of a circular *** solid walls,fluid walls morph during flows as pressures fall,with wall shape changing down the *** model is validated experimentally for Fourier numbersrescein diffusing between laminar *** enables a priori prediction of concentration gradients throughout a conduit,so allowing rapid circuit design as well as providing bioscientists with an accurate way of predicting local concentrations of bioactive molecules around responsive and nonresponsive cells.

关键词： walls diffusion attractive

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Single-atom Pt on carbon nanotubes for selective electrocatalysis

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Carbon Energy 2024年第1期6卷 63-71页

作者： Samuel S.Hardisty Xiaoqian Lin Anthony r.j.Kucernak David Zitoun Department of Chemistry Bar Ilan Institute of Nanotechnology and Advanced Materials(BINA)Bar Ilan UniversityRamat GanIsrael Department of Chemistry Molecular Science Research HubImperial College LondonLondonUK

Utilizing supported single atoms as catalysts presents an opportunity to reduce the usage of critical raw materials such as platinum,which are essential for electrochemical reactions such as hydrogen oxidation reaction(HOr).Herein,we describe the synthesis of a Pt single electrocatalyst inside single-walled carbon nanotubes(SWCNTs)via a redox *** via electron microscopy,X-ray photoelectron microscopy,and X-ray absorption spectroscopy show the single-atom nature of the *** electrochemical behavior of the sample to hydrogen and oxygen was investigated using the advanced floating electrode technique,which minimizes mass transport limitations and gives a thorough insight into the activity of the *** single-atom samples showed higher HOr activity than state-of-the-art 30%Pt/C while almost no oxygen reduction reaction activity in the proton exchange membrane fuel cell operating *** selective activity toward HOr arose as the main fingerprint of the catalyst confinement in the SWCNTs.

关键词： confinement electrocatalysis hydrogen platinum single atom catalysts

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Stand dynamics of old-growth hemlock forests in central Bhutan are shaped by natural disturbances

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Forest Ecosystems 2024年第4期11卷 434-447页

作者： Karma Tenzin Craig r.Nitschke Kathryn j.Allen raphael Trouve Thiet V.Nguyen Patrick j.Baker School of Agriculture Foodand Ecosystem SciencesUniversity of Melbourne500 Yarra BlvdRichmondVictoriaAustralia School of Geography Planningand Spatial SciencesUniversity of TasmaniaSandy BayTasmaniaAustralia Forest Science Institute of South Vietnam 1 Pham Van Hai StreetTan Binh DistrictHo Chi Minh CityViet Nam

Understanding how past disturbances have influenced the development of forests is critical for deciphering their current structure and composition and forecasting future *** this study,dendrochronological methods were applied to uncover the disturbance history of old-growth hemlock-dominated forests in central *** of tree-ring samples from two old-growth hemlock stands,located in two different topographic settings,identified the importance of gap-phase dynamics in facilitating recruitment and growth releases and producing complex,multi-aged structure s over *** site showed evidence of a near stand-replacing disturbance in the late 1700s,while the other showed no evide nce of high-severity disturbance at any time over the last 400 *** both sites low-to medium-severity disturbances,some of which appear to be associated with cyclones originating in the Bay of Bengal,dominated the disturbance *** hemlock stands exhibited a significant positive association between cyclone occurrence and growth release events and between recruitment pulses and growth release *** 1800 to 1970 there was an increase in recruitment of angiosperm tree species at most sites and a corresponding decline in conifer *** the past 50 years there has been little new recruitment;this may be due to light limitation in the understory from shade-tolerant angiosperms and bamboo in the lower strata of these *** variations in disturbance dynamics and recruitment were observed across the study sites,suggesting that other factors,such as topography and climate,may be influencing long-term stand development *** study highlights the complex interplay between historical disturbance regimes and tree recruitment in shaping the age and size structures of old-growth hemlock forests in central *** also provides new insights into the dynamics of these forests that can be used to support effective forest conservation and management i

关键词： Forest structure Hemlock forest Himalaya Natural disturbance

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Analysis of mid-spatial frequency wavefront distortions from a liquid-cooled flash-lamp pumped Nd:phosphate laser amplifier

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High Power Laser Science and Engineering 2024年第1期12卷 24-29页

作者： Pierre-Marie Dalbies Sandy Cavaro Edouard Bordenave Nathalie Blanchot julien G.Moreau jérôme Neauport CEA CESTA Le BarpFrance

Mid-spatial frequency wavefront deformation can be deleterious for the operation of high-energy laser systems. When fluid cooled high-repetition-rate amplifiers are used, the coolant flow is likely to induce such detrimental mid-spatial frequency wavefront deformations. Here, we describe the design and performance of a 90 mm × 90 mm aperture, liquid-cooled Nd:phosphate split-slab laser amplifier pumped by flash-lamps. The performance of the system is evaluated in terms of wavefront aberration and gain at repetition rates down to 1 shot per minute. The results show that this single cooled split-slab system exhibits low wavefront distortions in the medium to large period range, compatible with a focus on target, and despite the use of liquid coolant traversed by both pump and amplified wavelengths. This makes it a potential candidate for applications in large high-energy laser facilities.

关键词： flash-lamp pumping high-power laser laser cooling neodymium glass wavefront error

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Europium recovery process by means of polymeric nanoparticles functionalized with acrylic acid,curcumin and fumaramide

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journal of rare Earths 2024年第10期42卷 1950-1959页

作者： P.A.Martínez-Montoya j.M.del río A.de j.Morales-ramirez M.Corea Escuela Superior de Ingeniería Química e Industrias Extractivas ESIQIE-IPNDepartamento de Ingeniería Metalúrgica UPALM S/N Col.Lindavista Escuela Superior de Ingenieria Química e Industrias Extractivas ESIQIE-IPNLaboratorio de Investigación en Polímeros y NanomaterialesUPALM S/N Col.Lindavista Centra de Investigación e Innovación Tecnológica CIITEC-IPNCda.de CECATIs/n

Polymeric nanoparticles of poly(methyl methacrylate) were obtained by emulsion polymerization techniques in a proce ss of two *** particles were functionalized with acrylic acid,curcumin,and fumaramide and three series of polymeric particles were *** incorporation of functional groups was confirmed by Fourier transform-infrared spectrosocopy(FT-Ir) and ultraviolet-visible(UV-Vis) *** spherical morphology of particles with an average diameter of 100 nm was observed by scartning electron microscopy(SEM).The polymeric materials were used for recovery of [Eu]from synthetic *** nanoparticles show excellent chelation capacity to trap rare-earth ions,because they recover more than 85% of [Eu] at pH of *** images of SEM after extraction process show arrays between particles with larger average particle sizes to 1.5 *** addition,the particles have a good stripping capacity,exceeding 50% of it,maintaining their homogeneity in morphology and good stability in dispersion for the recovery and stripping processes.A pseudo-second model order is obtained for the extraction and stripping processes while the best results of stripping process are obtained at pH of6.

关键词： [Eu] recovery Chelating effect Extraction process Stripping process Emulsion polymerization rare earths

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Error field penetration in j-TEXT tokamak based on two-fluid drift-MHD model

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Chinese Physics B 2024年第4期33卷 545-551页

作者：王文徐涛张仪 the j-TEXT team State Key Laboratory of Advanced Electromagnetic Technology International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma PhysicsSchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074China

An externally generated resonant magnetic perturbation can induce complex non-ideal MHD responses in their resonant *** have studied the plasma responses using Fitzpatrick's improved two-fluid model and program *** calculated the error field penetration threshold for *** addition,we find that the island width increases slightly as the error field amplitude increases when the error field amplitude is below the critical penetration ***,the island width suddenly jumps to a large value because the shielding effect of the plasma against the error field disappears after the *** scanning the natural mode frequency,we find that the shielding effect of the plasma decreases as the natural mode frequency ***,we obtain the m/n=2/1 penetration threshold scaling on density and temperature.

关键词： plasma responses drift-MHD model error field penetration

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