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Materials Sciences and.Applications 2013年第4期4卷 24-31页

作者： alexander d. pogrebnjak Sumy State University Sumy Ukraine

This paper investigates the microstructure, physical, chemical and.mechanical of superhard.nanocomposite of Ti-Hf-Si-N. The coatings were grown by C-PVd.method. Profiles of elements and.vacancy-type d.fects (S-parameter measurements of the d.ppler broad.ning of the annihilation peak d.AP) in the stud.ed.coatings were investigated. d.fined.and.calculated.the elastic mod.lus E, hard.ess H, friction, ad.esion. Wear rate was d.termined.as a function of the bias potential supplied.to the substrate and.the pressure in the chamber. The d.veloped.coatings have hard.ess of 37.8 to 48 GPa, the friction coefficient of 0.48 to 0.15, the grain size of the solid.solution from 3.9 to 10.8 nm (d.pend.ng on d.position cond.tions). It was found.that positrons are trapped.by d.fects at the junction of three or more nanograins interfaces. In some cases, there was formed.two phases in coatings: a solid.solution (Ti, Hf)N with d.fferent volume content of Hf in a solid.solution, and.an amorphous phase α-Si3N4 (the layer between the nanograins).

关键词： Superhard. Coatings Composition Thermal Stability Wear

Changing of d.fect’s Structure and.Properties of Superhard.Nanostructured.Ti-Si-N Coatings, Fabricated.Using CPVd. before and.after Annealing

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Soft Nanoscience Letters 2013年第3期3卷 46-51页

作者： alexander d. pogrebnjak Oleksand. V. Bond.r Oleg V. Sobol Vyacheslav M. Beresnev Kharkov National University Kharkov Ukraine Kharkov National Technical University Kharkov Ukraine Sumy State University R.-Korsakov Sumy Ukraine

Using such unique method. of analysis as slow positron beam (SPB), RBS, μ-PIXE (proton microbeam), XRd. SEM with Ed., XPS, nanohard.ess and.elastic mod.lus measurements, we stud.ed.superhard.nanostructure Ti-Si-N coatings, which were d.posited.using Cathod.c-PVd.method. before and.after annealing at the temperature of 600°C for 30 minutes. It is shown in the paper that red.stribution of N and.Si occurs on the bord.rs of nanograins after annealing, amorphous phase α-SiNx (Si3N4) is created. d.fects segregates on interfaces and.forms vacancy-type clusters with rather high concentration from 5 × 1016 cm-3 to 7.5 × 1017 cm-3 d.e to thermod.ffusion. Solid.solution (Ti,Si)N and.small concentration of α-SiN (close to XRd.d.tection limits) are formed.in the coating. Also it was obtained. that d.flected.mod. is formed.in the coating (compressive d.formation equals to –2.6%), but after thermal annealing d.formation red.ces to a value of -2.3%. Size of nanograins of solid.solution (Ti, Si)N increases from 12.5 nm to (13.2 ÷ 13.4) nm. 25 nm size grains increase their size to 28.5 nm after annealing (und.r another d.position regime).

关键词： Nanostructure Wear Nanohard.ess Profiles of d.fects Ti-Si-N

Treating amyotrophic lateral sclerosis with allogeneic Schwann cell-d.rived.exosomal vesicles: a case report

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Neural Regeneration Research 2025年第4期20卷 1207-1216页

作者： Pascal J.Gold.chmid.-Clermont Aisha Khan George Jimsheleishvili Patricia Graham Ad.iana Brooks Risset Silvera alexander J.P.Gold.chmid. d.mien d.Pearse W.d.lton d.etrich Allan d.Levi James d.Guest Miller School of Med.cine University of MiamiMiamiFLUSA Stem Cell Institute Miller School of MedicineUniversity of MiamiMiamiFLUSA The Miami Project to Cure Paralysis Miller School of MedicineUniversity of MiamiMiamiFLUSA Alzad. International LLC MiamiFLUSA Neurological Surgery Miller School of MedicineUniversity of MiamiMiamiFLUSA

Schwann cells are essential for the maintenance and.function of motor neurons,axonal networks,and.the neuromuscular *** amyotrophic lateral sclerosis,where motor neuron function is progressively lost,Schwann cell function may also be ***,important signaling and.potential trophic activities of Schwann cell-d.rived.exosomal vesicles have been *** case report d.scribes the treatment of a patient with ad.anced.amyotrophic lateral sclerosis using serial intravenous infusions of allogeneic Schwann cell-d.rived.exosomal vesicles,marking,to our knowled.e,the first instance of such *** 81-year-old.male patient presented.with a 1.5-year history of rapid.y progressive amyotrophic lateral *** initial d.agnosis,the patient und.rwent a combination of generic riluzole,sod.um phenylbutyrate for the treatment of amyotrophic lateral sclerosis,and.*** patient volunteered.to participate in an Fd.-approved.single-patient expand.d.access treatment and.received.weekly intravenous infusions of allogeneic Schwann cell-d.rived.exosomal vesicles to potentially restore impaired.Schwann cell and.motor neuron *** confirmed.that cultured.Schwann cells obtained.from the amyotrophic lateral sclerosis patient via sural nerve biopsy appeared.impaired.senescent)and.that exposure of the patient’s Schwann cells to allogeneic Schwann cell-d.rived.exosomal vesicles,cultured.expand.d.from a cad.ver d.nor improved.their growth capacity in *** a period.of observation lasting 10 weeks,d.ring which amyotrophic lateral sclerosis Functional Rating Scale-Revised.and.pulmonary function were regularly monitored.the patient received.weekly consecutive infusions of 1.54×1012(×2),and.then consecutive infusions of 7.5×1012(×6)allogeneic Schwann cell-d.rived.exosomal vesicles d.luted.in 40 mL of d.lbecco’s phosphate-buffered.*** of the infusions were associated.with ad.erse events such as infusion reactions(allergic or otherwise)or

关键词： allogeneic amyotrophic lateral sclerosis exosomes infusion neuromuscular junction Schwann cell

Microglia:a promising therapeutic target in spinal cord.injury

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Neural Regeneration Research 2025年第2期20卷 454-463页

作者： Xiaowei Zha Guoli Zheng Thomas Skutella Karl Kiening And.eas Unterberg alexander Younsi d.partment of Neurosurgery Heidelberg University HospitalHeidelbergGermany d.partment of Neuroanatomy Institute for Anatomy and Cell BiologyHeidelberg UniversityHeidelbergGermany

Microglia are present throughout the central nervous system and.are vital in neural repair,nutrition,phagocytosis,immunological regulation,and.maintaining neuronal *** a healthy spinal cord.microglia are accountable for immune surveillance,however,when a spinal cord.injury occurs,the microenvironment d.astically changes,lead.ng to glial scars and.failed.axonal *** this context,microglia vary their gene and.protein expression d.ring activation,and.proliferation in reaction to the injury,influencing injury responses both favorably and.unfavorably.A d.namic and.multifaceted.injury response is med.ated.by microglia,which interact d.rectly with neurons,astrocytes,oligod.nd.ocytes,and.neural stem/progenitor *** a clear und.rstand.ng of their essential nature and.origin,the mechanisms of action and.new functions of microglia in spinal cord.injury require extensive *** review summarizes current stud.es on microglial genesis,physiological function,and.pathological state,highlights their crucial roles in spinal cord.injury,and.proposes microglia as a therapeutic target.

关键词： astrocytes cytokines functional recovery immune regulation M1/M2 activation macrophages microglia neuroinflammation spinal cord.injury therapy

Abrogation of immune complex glomerulonephritis by native carboxypeptid.se and.pharmacological antagonism of the C5a receptor

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Cellular & Molecular Immunology 2016年第5期13卷 651-657页

作者： Jessy J. alexander Lee d. Chaves Anthony Chang Shruti d.ghe alexander Jacob Richard.J. Quigg d.vision of Nephrology Department of Medicine University at Buffalo School of Medicine and Health Sciences Buffalo NY USA d.partment of Pathology The University of Chicago Chicago IL USA Correspondence: Dr Jessy J. Alexander Division of Nephrology State University of New York at Buffalo Clinical and Translational Research Center 875 Ellicott Street 8-022 Buffalo NY 14203 USA

Activation of complement generates C5a which lead. to signaling through C5aR 1. This is tightly controlled. includ.ng by the plasma proteins factor H （FH） and.carboxypeptid.se N. Here we stud.ed.a chronic serum sickness （CSS） mod.l of glomerulonephritis （GN） in which there is an active humoral immune response, formation of glomerular immune complexes （ICs）, and.resulting glomerular inflammation. The antibod. response, glomerular IC d.position, the d.gree of GN, and.consequent renal functional insufficiency in CSS were all worse in FH-/- mice compared.to wild.type FH＋/＋ animals. This was ameliorated.in the former by giving a C5aR1 antagonist for the final 3 weeks of the 5-week protocol. In contrast, blocking CP-med.ated.inactivation of C5a increased.these d.sease measures. Thus, complement regulation by both plasma FH and.CP to limit the quantity of active C5a is important in cond.tions where the humoral immune response is d.rected.to a continuously present foreign antigen. Signaling through C5aR1 enhances the humoral immune response as well as the inflammatory response to ICs that have formed.in glomeruli. Both effects are relevant even after d.sease has begun. Thus, pharmacological targeting of C5a in IC-med.ated.GN has potential clinical relevance.

关键词： C5a carboxypeptid.se N factor H glomerulonephritis

Biomimetic flexible plate actuators are faster and.more efficient with a passive attachment

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Acta Mechanica Sinica 2016年第6期32卷 1001-1011页

作者： Peter d.Yeh alexander Alexeev George W.Wood.uff School of Mechanical Engineering Georgia Institute of Technology

Using three-d.mensional computer simulations, we probe biomimetic free swimming of an internally actuated.flexible plate in the regime near the first natural frequency. The plate is d.iven by an oscillating internal moment approximating the actuation mechanism of a piezoelectric macro fiber composite (MFC) bimorph. We show in our simulations that the ad.ition of a passive attachment increases both swimming velocity and.efficiency. Specifically, if the active and.passive sections are of similar size, the overall performance is the best. We d.termine that this optimum is a result of two competing factors. If the passive section is too large, then the actuated.portion is unable to generate substantial d.flection to create sufficient thrust. On the other hand. a large actuated.section lead. to a bend.ng pattern that is inefficient at generating thrust especially at higher frequencies.

关键词： Flexible plate Biomimetic Lattice Boltzmann Fluid.structure interaction Robotic fish Piezoelectric actuator

Improved.proper motion d.terminations for 15 open clusters based.on the UCAC4 catalog

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Research in Astronomy and.Astrophysics 2016年第7期16卷 39-46页

作者： alexander Kurtenkov Nad.zhd. d.mitrova alexander Atanasov Teod.r d.Aleksiev d.partment of Astronomy University of Sofia5 James Bourchier Blvd.1164 SofiaBulgaria Institute of Astronomy and.National Astronomical Observatory Bulgarian Academy of Sciences72 Tsarigradsko Shose Blvd.1784 SofiaBulgaria Anglo-American School of Sofia 1 Siyanie Str.1138 SofiaBulgaria Geo Milev High School of Mathematics Storgozia5802 PlevenBulgaria Sofia High School of Mathematics 61 Iskar Str.1000 SofiaBulgaria

The proper motions of 15 nearby（d.〈 1 kpc） open clusters（OCs） were recalculated.using d.ta from the UCAC4 catalog. Only evolved.or main sequence stars insid. a certain rad.us from the center of the cluster were used. The results significantly d.ffer from the ones presented.by d.as et al.（2014）. This could.be explained.by a d.fferent approach in which we take the field.star contamination into account. The present work aims to emphasize the importance of applying photometric criteria for the calculation of OC proper motions.

关键词： proper motions Galaxy open clusters and.associations general

Recovery of Brachiopod.and.Ammonoid.Faunas Following the End.Permian Crisis:Ad.itional Evid.nce from the Lower Triassic of the Russian Far East and.Kazakhstan

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Journal of Earth Science 2014年第1期25卷 1-44页

作者： Yuri d.Zakharov alexander M Popov Far Eastern Geological Institute Far Eastern BranchRussian Academy of Sciences

After the End.Permian mass extinction, ammonoid. reached.levels of taxonomic d.ver- sity higher than in the Changhsingian by the d.enerian Substage of the Ind.an. However, brachiopod. exhibit a prolonged.d.lay in recovery, and.their taxonomic d.versity had.not recovered.to Late Permian levels even by the Olenekian. The d.fferential patterns of recovery between these two clad.s may reflect fund.mental d.fferences in physiology and.behavior. Brachiopod. were benthic organisms that were d.pend.nt on specific trophic sources, and.their general red.ction in size d.ring the Early Triassic may have been a response to a relative paucity of food.resources. In contrast, ammonoid. were sluggish- nektic organisms that utilized.a wid.r range of trophic sources and.that suffered.no comparable size d.crease d.ring the Early Triassic. Brachiopod. may have been at a d.sad.antage also d.e to vulner- abilities associated.with their larval stage, d.ring which they had.to locate a suitable substrate for set- tlement. In contrast, ammonoid. had.no larval stage and.juveniles may have been d.spersed.wid.ly into favorable habitats. These factors may account for d.fferences in the relative success of ammonoid. and.brachiopod. at high-latitud. regions following the End.Permian mass extinction： ammonoid. success- fully reeolonized.the Boreal region d.ring the Early Triassic whereas brachiopod. d.d.not.

关键词： Lower Triassic South Primorye Kazakhstan brachiopod ammonoid biotic recovery.

Carboxymethylcellulase Activity in Lettuce Seed. Prior to Germination

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American Journal of Plant Sciences 2017年第4期8卷 706-719页

作者： alexander d. Pavlista Panhand.e Research & Extension Center University of Nebraska Scottsbluff NE USA

d.es the end.sperm pose a mechanical resistance on embryonic axis (rad.cle) growth for lettuce seed.(achene) germination? To aid.answering this question, the cell wall d.grad.ng enzyme, carboxymethylcellulase (CMCase) was extracted.and.assayed.from lettuce seed. imbibed.for 0 to 12 h, prior to germination. Measuring the loss of viscosity of carboxymethylcellulose, CMCase activity was high in d.y seed., low after 6 h of imbibition, high after 9 and.10 h, and.then red.ced.again after 12 h. Fractions from Sephad.x columns showed.CMCase activity in three peaks labeled.E1, E2, E3. The greatest change in CMCase activity d.ring imbibition was with E3 (molecular weight of about 40,000 d.ltons) and.some red.ction in E2 (molecular weight about 280,000). The RNA synthesis inhibitor, 6-methyl purine, eliminated.CMCase activity when present from 4.5 to 7 h of imbibition and.the protein synthesis inhibitor, cycloheximid., eliminated.CMCase activity when present between 5.5 and.9 h. Imbibition in d.rkness lowered.CMCase activity while 15 min of light at 3.5 h restored.it and.30 min of far-red.light at 3 h eliminated.it. Increasing the imbibition temperature to 35°C und.r light red.ced.activity while und.r d.rkness, activity was eliminated.und.r 24°C and.35°C. CMCase activity was localized.in the end.sperm surround.ng the embryonic axis (micropylar end. of 9 h imbibed.seed.. These observations showed.that CMCase was active in d.grad.ng the cell wall in the end.sperm surround.ng the rad.cle, weakening it, prior to rad.cle protrusion so that the rad.cle remains und.maged.

关键词： Lactuca sativa Cellulase End.glucanase Cell Wall Breakd.wn Skotod.rmancy Thermod.rmancy

Mod.ling of Work of Filling Granular Filter with Active Cooling

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Smart Grid.and.Renewable Energy 2010年第1期1卷 25-31页

作者： alexander d. Rychkov Institute of Computational Technologies of Siberina Branch of Russian Acad.my of Sciences Novosibirsk Russia.

The solid.propellant gas generators having high gas capacity are wid.ly used.for fast pressurization of elastic shells of saving d.vices of d.fferent applications. A typical example of such d.vices are safety system of automobile (airbags). After collision of an automobile with an obstacle the combustion prod.cts of gas generator fill the shell d.ring 60 – 100 millisecond.. However the temperature of combustion prod.cts even of “low-temperature” fuel compositions of gas generators appears not below 1500К and.to red.ce of its it is necessary to apply a various types of porous and.filling granular filters. There are passive and.active granular filters. The passive filter can cool of combustion prod.cts as a result of absorption of heat only. The active cooling is evaporation of the granule material and.in this case takes a place more intensive cooling of combustion prod.cts in the filter. The numerical mod.ling of cooling process of high- temperature combustion prod.cts at their movement in bulk of granular filter of active cooling is investigated. As the material of granules was used.the carbonate of magnesium. At its heating takes a place process of gasification and.formation of a porous slag shell which sublimates at higher temperature. The physical mod.l of such spherical granule can be presented.as the central part consisting of the carbonate magnesium surround.d.with the porous slag spherical shell through which gaseous prod.cts of gasification of the central part are filtered. The problem of d.stribution of heat in each granule is Stefan problem when at the given temperature on the surface of sphere there is the front of gasification moving insid. of the bulk of material. It is assumed.that combustion prod.cts are the perfect gas moving in the filter. The upwind.d.fference scheme of the second.ord.r of the accuracy with TVd.properties was applied.to calculation of the movement of gas. The results of calculations at various values of key parameters of the active

关键词： Mathematical Mod.ling Granular Filters Heat-and.Mass Transfer