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“Sitting-up vertigo as an expression of posterior semicircular canal heavy cupula and posterior semicircular canal short arm canalolithiasis”

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Journal of Otology 2022年第2期17卷 101-106页

作者： Darío H.Scocco María A.Barreiro ivan e.garcía Institute of Neuroscience Favaloro Foundation University HospitalBuenos AiresArgentina

Background:Vestibular symptoms on sitting-up are frequent on patients seen by vestibular ***,a benign paroxysmal positional vertigo(BPPV)variant which elicits vestibular symptoms with oculomotor evidence of posterior semicircular canal(P-SCC)cupula stimulation on sitting-up was described and named sitting-up vertigo BPPV.A periampullar restricted P-SCC canalolithiasis was proposed as a causal ***:To describe new mechanisms of action for the sitting-up vertigo BPPV ***:eighteen patients with sitting-up vertigo BPPV were examined with a pre-established set of positional maneuvers and follow-up until they resolved their symptoms and clinical ***:All patients showed up-beating torsional nystagmus(UBTN)and vestibular symptoms on coming up from either Dix-Hallpike(DHM)or straight head-hanging *** out of 18 patients presented a sustained UBTN with an ipsitorsional component to the tested side on half-Hallpike maneuver(HH).A slower persistent contratorsional down-beating nystagmus was found in eleven out18 patients tested on nose down position(ND).Conclusions:Persistent direction changing positional nystagmus on HH and ND positions indicative of PSCC heavy cupula was found in 11 patients.A sustained UBTN on HH with the absence of findings on ND,which is suggestive of the presence of P-SCC short arm canalolithiasis,was found on 5 *** patients were treated with canalith repositioning maneuvers without success,but they resolved their findings by means of Brandt-Daroff *** propose P-SCC heavy cupula and P-SCC short arm canalolithiasis as two new putative mechanisms for the sitting-up vertigo BPPV variant.

关键词： BPPV Benign paroxysmal positional vertigo Vertigo Residual dizziness Subjective BPPV Sitting up vertigo Heavy cupula Short arm canalolithiasis

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engineering of immunoinstructive extracellular matrices for enhanced osteoinductivity

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Bioactive Materials 2023年第6期24卷 174-184页

作者： Andrés garcía-garcía Sébastien Pigeot ivan Martin Department of Biomedicine University Hospital BaselUniversity of Basel4031BaselSwitzerland Department of Biomedical engineering University of Basel4123AllschwillSwitzerland

The increasing recognition of the contribution of the immune system to activate and prime regeneration implies that tissue engineering strategies and biomaterials design should target regulation of early immunological *** previously proposed the cell-based engineering and devitalization of extracellular matrices(eCMs)as a strategy to generate implant materials delivering custom-defined ***,in the context of bone regeneration,we aimed at enhancing the osteoinductivity of such eCMs by enriching their immunomodulatory factors *** with IL1βa cell line overexpressing BMP-2 enabled engineering of eCMs preserving osteoinductive signals and containing larger amounts of angiogenic(VeGF)and pro-inflammatory molecules(IL6,IL8 and MCP1).Upon implantation,these IL1β-induced materials enhanced processes typical of the inflammatory phase(e.g.,vascular invasion,osteoclast recruitment and differentiation),leading to‘regenerative’events(e.g.,M2 macrophage polarization)and ultimately resulting in faster and more efficient bone *** results bear relevance towards the manufacturing of potent off-the-shelf osteoinductive materials and outline the broader paradigm of engineering immunoinstructive implants to enhance tissue regeneration.

关键词： Immunomodulation Bone tissue engineering Inflammation Hypertrophic cartilage matrices Osteoinduction

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Influence of Methane-Hydrogen Mixture Characteristics on Compressor Vibrations

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Fluid Dynamics & Materials Processing 2024年第5期20卷 1031-1043页

作者： Vladimir Ya.Modorskii ivan e.Cherepanov High Performance Computing Center Perm National Research Polytechnic UniversityPerm614990Russia

A transition to clean hydrogen energy will not be possible until the issues related to its production, transportation,storage, etc., are adequately resolved. Currently, however, it is possible to use methane-hydrogen *** gas can be transported using a pipeline system with the required pressure being maintained by gascompression stations. This method, however, is affected by some problems too. Compressors emergency stopscan be induced by vibrations because in some cases, mechanical methods are not able to reduce the vibrationamplitude. As an example, it is known that a gas-dynamic flow effect in labyrinth seals can lead to increasedvibrations. This paper presents the numerical simulation of rotor oscillations taking into account a gas-dynamicload. The influence of a transported mixture on the oscillatory process is investigated. Mixtures consisting ofmethane and hydrogen in various proportions and an air mixture are considered. The results are discussed forvarious operating pressures and include the rotor motion trajectories and oscillation frequency spectra obtainednumerically. It is shown that the gas mixture composition has a significant effect on the oscillations and theiroccurrence. Hydrogen as a working fluid reduces the vibration amplitude. Operating a compressor with hydrogenleads to a decrease in the resonant frequency, bringing it closer to the operating one. However, the operatingpressure at which maximum oscillations are observed depends slightly on the gas mixture composition.

关键词： Seal stabilities vibration FSI CFD multiphase flows hydrogen

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LOW-RANK TeNSOR STRUCTURe OF SOLUTIONS TO eLLIPTIC PROBLeMS WITH JUMPING COeFFICIeNTS

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Journal of Computational Mathematics 2012年第1期30卷 14-23页

作者： Sergey Dolgov Boris N.Khoromskij ivan Oseledets eugene e.Tyrtyshnikov Moscow Institute of Physics and Technology Russia Max-Planck-Institute for Mathematics in Sciences Inselstr.22-26D-04103 LeipzigGermany Institute of Numerical Mathematics Russian Academy of SciencesGubkina 8119991 MoscowRussia Lomonosov Moscow State University Russia University of Siedlce Poland(visiting professor)

We study the separability properties of solutions to elliptic equations with piecewise constant coefficients in Rd, d ≥ 2. The separation rank of the solution to diffusion equation with variable coefficients is prese... 详细信息

关键词： Structured matrices elliptic operators Poisson equation Matrix approxima-tions Lowrank matrices Tensors Canonical decomposition.

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RF thermal and new cold part design studies on a TTF-Ⅲ input coupler for Project-X

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Chinese Physics C 2012年第2期36卷 173-178页

作者： PeI Shi-Lun Chris e Adolphsen LI Zeng-Hai Nikolay A Solyak ivan V Gonin Institute of High energy Physics Chinese Academy of SciencesBeijing 100049China SLAC National Accelerator Laboratory Menlo ParkCalifornia 94025USA Fermi National Accelerator Laboratory Batavia 60510IllinoisUSA

An RF power coupler is one of the key components in a superconducting （SC） linac. It provides RF power to the SC cavity and interconnects different temperature layers （1.8 K, 4.2 K, 70 K and 300 K）. The TTF-Ⅲ coupler is one of the most promising candidates for the High energy （He） linac of Project X, but it cannot meet the average power requirements because of the relatively high temperature rise on the warm inner conductor, so some design modifications will be required. In this paper, we describe our simulation studies on the copper coating thickness on the warm inner conductor with RRR values of 10 and 100. Our purpose is to rebalance the dynamic and static loads, and finally lower the temperature rise along tbe warm inner conductor. In addition, to get stronger coupling, better power handling and less multipacting probability, one new cold part design was proposed using a 60 mm coaxial line; the corresponding multipacting simulation studies have also been investigated.

关键词： RF thermal effect TTF-Ⅲ input coupler multipacting dynamic RF power loss static thermal loss

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effects of pre-existing cracks and infillings on strength of natural rocks--Cases of sandstone, argillite and basalt

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Journal of Rock Mechanics and Geotechnical engineering 2020年第6期12卷 1333-1338页

作者： Chen Cui ivan Gratchev School of engineering Griffith UniversityGold CoastAustralia

This study aims to examine the influence of pre-existing discontinuities on the strengths of four natural rocks of different origins.A series of unconfined compression tests was performed on specimens of two types of sandstones,argillite and basalt that contain open and filled *** was found that the presence of cracks tends to decrease the overall strength for all studied rocks;however,the magnitude of strength reduction is related to the property of *** larger strength decrease was observed for the relatively harder argillite and basalt,compared to the softer *** was also found that the infill material could increase the strength of rock specimens,while the obtained strength depended on the characteristics of the fill material.

关键词： Pre-existing crack Rock strength Infill material Laboratory test

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Oscillatory Dynamics of a Spherical Solid in a Liquid in an Axisymmetric Variable Cross Section Channel

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Fluid Dynamics & Materials Processing 2024年第6期20卷 1219-1232页

作者： ivan Karpunin Laboratory of Vibrational Hydromechanics Perm State Humanitarian Pedagogical UniversityPerm614990Russia

The dynamics of a solid spherical body in an oscillating liquid flow in a vertical axisymmetric channel of variable cross section is experimentally *** is shown that the oscillating liquid leads to the generation of intense averaged flows in each of the channel *** intensity and direction of these flows depend on the dimensionless oscillating *** the region of studied frequencies,the dynamics of the considered body is examined when the primary vortices emerging in the flow occupy the whole region in each *** a fixed frequency,an increase in the oscillation amplitude leads to a phase-inclusion holding effect,i.e.,the body occupies a quasi-stationary position in one of the cells of the vertical channel,while oscillating around its average *** is also shown that the oscillating motion of a liquid column generates an averaged force acting on the body,the magnitude of which depends on the properties of the body and its position in the *** quasi-stationary position is determined by the relative density and size of the body,as well as the dimensionless *** behavior of the body as a function of the amplitude and frequency of fluid oscillation and relative size is discussed in *** findings may be used in the future to control the position of a phase inclusion and/or to strengthen mass transfer effects in a channel of variable cross section by means of fluid oscillations.

关键词： Phase inclusion axisymmetric channel variable cross section oscillations dimensionless frequency averaged force viscous boundary layer

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Combined influence of Ce(Ⅲ)and iodide ions for corrosion protection of AA 2024-T3 in acidic to neutral chloride-rich environments:electrochemical and surface characterization studies

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Journal of Rare earths 2023年第2期41卷 309-320页

作者： Mohammed A.el-Hashemy Anthony e.Hughes Thomas Gengenbach A.Matthew Glenn ivan S.Cole Chemistry Department College of ScienceJouf UniversityP.O.Box 2014SakakaAljoufSaudi Arabia Air Pollution Research Department Environmental and Climate Change Research InstituteNational Research CentreDokkiGiza12622Egypt CSIRO Mineral Resources ClaytonVic3168Australia CSIRO Manufacturing ClaytonVic3168Australia School of engineering RMIT UniversityCarltonVic3053Australia

It has been reported that trivalent cerium salts are effective inhibitors for corrosion of AA2024-T3 in neutral to alkaline co rrosive enviro nments,but poor in acidic *** this study,work was done for extending corrosion resistance provided by Ce(NO_(3))_(3)to acidic pHs as low as 2.5 through the addition of iodide *** this end,potentiodynamic polarization was used to ascertain the optimum Ce(Ⅲ)concentration for the inhibition of AA2024-T3 corrosion in 3.5%NaCl *** optimum concentration is found to be in a range between 0.1 and 0.3 mmol/L Ce(Ⅲ).This optimum concentration also gives a maximum width of the passive region under the pitting potential(epit).Based on this optimization,further work was performed as a function of pH without and in the presence of 0.01 mol/L KI at five pH values(2.5,4,5,7,and 8).Without iodide the best inhibition provided by the Ce(Ⅲ)cation is at pH=7 but active corrosion is observed at pH=2.5 with an estimated inhibitor efficiency(-37.6%).The addition of iodide ions(I^(-))reverses the poor corrosion resistance whereby the inhibitor efficiency becomes 47.7%.Moreover,at pH=4 the efficiency is also increased from 54.0%to 81.0%with iodide addition providing a significant improvement over Ce(Ⅲ)cations alone under acidic *** is a synergistic effect between I-anion and Ce(Ⅲ)cation,which is determined to be 2.4 and 2.1 at pH=2.5and 4.0,*** pH=5 and 7 there is virtually no change in inhibition but at pH=8 the inhibition falls away due to a considerable amount of cerium precipitating out of solution as cerium *** protective film formed on sites in the aluminium alloy surface at different pH values was examined by both scanning electron microscopy with energy dispersive X-ray analysis and X-ray photoelectron spectroscopy to determine the role of these ions as a function of pH in surface *** is proposed that at pH=2.5 protection is provided by a bilayer adsorption of iodide with"cap

关键词： Aluminium alloy Cerium(Ⅲ)salt Potassium iodide Corrosion inhibitor XPS Rare earths

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Supercurrent decay in ballistic magnetic Josephson junctions

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npj Computational Materials 2022年第1期8卷 186-196页

作者： HervéNess ivan A.Sadovskyy Andrey e.Antipov Mark van Schilfgaarde Roman M.Lutchyn Department of Physics King’s College LondonStrand CampusLondonWC2R 2LSUK Microsoft Quantum Microsoft Station QUniversity of CaliforniaSanta BarbaraCA93106USA National Renewable energy Laboratory GoldenCO80401USA

We investigate transport properties of ballistic magnetic Josephson junctions and establish that suppression of supercurrent is an intrinsic property of the junctions,even in absence of *** studying the role of ferromagnet thickness,magnetization,and crystal orientation we show how the supercurrent decays exponentially with thickness and identify two mechanisms responsible for the effect:(i)large exchange splitting may gap out minority or majority carriers leading to the suppression of Andreev reflection in the junction,(ii)loss of synchronization between different modes due to the significant dispersion of the quasiparticle velocity with the transverse *** results for Nb/Ni/Nb junctions are in good agreement with recent experimental *** approach combines density functional theory and the Bogoliubov-de Gennes model and opens a path for material composition optimization in magnetic Josephson junctions and superconducting magnetic spin valves.

关键词： Josephson decay magnetic

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Hypertensive emergency versus preeclampsia in a patient with sickle cell disease:a case report

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World Journal of emergency Medicine 2023年第4期14卷 329-331页

作者： Jigar Patel Juan A Reyes ivan Berezowski Quincy K Tran Sarah e Frasure Ali Pourmand Division of Hospital Medicine Department of Medicinethe George Washington UniversityWashington DC 20037USA Department of emergency Medicine University of Maryland School of MedicineBaltimore 21201-1544USA Program in Trauma the R Adams Cowley Shock Trauma CenterUniversity of Maryland School of MedicineBaltimore 21201USA Department of emergency Medicine the George Washington University School of Medicine and Health SciencesWashington DC 20037USA

Sickle cell disease(SCD)is strongly associated with severe preeclampsia and has also been linked to poor pregnancy-related ***,sickle cell nephropathy(SCN)is a common complication of SCD and results in chronic *** patients with SCD who present to the emergency department(eD)with pulmonary edema,hypertension,and proteinuria may suffer from a hypertensive emergency with or without *** prior lab work to determine whether a patient’s proteinuria or kidney dysfunction is new or at baseline,it may be impossible for the emergency physician to determine which diagnosis is more ***,amultidisciplinary approach which involves cardiology,nephrology,medicine and obstetrics consultations should be utilized to help direct *** present the case of a 39-yearold patient with SCD,who was also 26 weeks pregnant,and presented to the eD with markedly elevated blood pressure and *** she was initially admitted to the obstetrics ward for blood pressure management given concern for preeclampsia,she was ultimately diagnosed with hypertensive emergency and sickle cell nephropathy.

关键词： hypertensive admitted markedly

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