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Plasma electrolytic oxidation of the magnesium alloy MA8 in electrolytes containing TiN nanoparticles

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Journal of Materials Science & Technology 2017年第5期33卷 461-468页

作者： D.v.Mashtalyar S.v.Gnedenkov S.l.Sinebryukhov I.M.Imshinetskiy A.v.Puz Institute of Chemistty Far Eastern BranchRussian Academy of Sciences 159Prosp.100-1etya VladivostokaVladivostok 690022Russia Far Eastern Federal University 8 Sukhanova St.Vladivostok690950Russia

The formation of protective multifunctional coatings on magnesium alloy MA8 using plasma electrolyt- ic oxidation （PEO） in an electrolytic system containing nanosized particles of titanium nitride was investigated. Electrochemical and mechanical properties of the obtained layers were examined. It was established that microhardness of the coating with the nanoparticle concentration of 3 gl-1 increased twofold （4.2 ± 0.5 GPa）, while wear resistance decreased （4.97 × 10-6 mm3 N-1 m-1）, as compared to re- spective values for the PEO-coating formed in the electrolyte without nanoparticles （2.1 ± 0.3 GPa, 1.12 × 10.5 mm3 N-1 m-1）.

关键词： Magnesium alloys Protective coatings Plasma electrolytic oxidation Corrosion titanium nitride Nanoparticles

Hydroxyapatite-containing PEO-coating design for biodegradable Mg-0.8Ca alloy: Formation and corrosion behaviour

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Journal of Magnesium and Alloys 2023年第12期11卷 4468-4484页

作者： A.S.Gnedenkov S.l.Sinebryukhov v.S.Filonina S.v.Gnedenkov Institute of Chemistry of FEB RAS 159 Pr.100-letiya VladivostokaVladivostok690022Russian Federation

In this study, the biocompatible protective coating was formed using plasma electrolytic oxidation(PEO) on bioresorbable Mg-0.8Ca alloy. The composition of the formed coating was studied using XRD, SEM-EDX analysis, and micro-Raman spectroscopy. The uniform distribution of hydroxyapatite over the thickness of protective PEO-layer was established. Using traditional(EIS, PDP, OCP) and local scanning electrochemical methods(SvET, SIET with H^(+)-selective microelectrode), the level of protective properties of PEO-layer in a biological environment(mammalian cell culture medium, MEM) was determined. It was established that modification of Mg-0.8Ca alloy surface by PEO contributes to a significant increase in the corrosion resistance of the surface layer, making it possible to control the process of material‘s biodegradation. The maximum local electrochemical activity was recorded after 72 h of testing, while for the uncoated sample,intense corrosion degradation was recorded in the first 12 min of exposure to the cell culture medium. Formation of the PEO-coating results in a twofold decrease in the corrosion current density(2.8·10^(-6)A cm^(-2)) and an increase in the impedance modulus measured at a low frequency(1.7·10^(4)Ω cm^(2)) in comparison with the uncoated material(9.5·10^(-6)A cm^(-2);8.1·10^(3)Ω cm^(2)). The mechanism of material bioresorption was established and a model for biodegradation process of Mg-0.8Ca alloy with hydroxyapatite-containing PEO-coating in MEM was proposed. Analysis of these results and comparing with others obtained by various scientific groups indicate the prospects for application of biocompatible PEO-coating on Mg-Ca alloy in implant surgery.

关键词： Magnesium-calcium alloy Biodegradation Implant surgery Plasma electrolytic oxidation Electrochemistry Minimum essential medium Hydroxyapatite

Expression of juvenile hormone acid O-methyltransferase and juvenile hormone synthesis in Blattella germanica

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Insect Science 2018年第5期25卷 787-796页

作者： Claudia v. Dominguez Jose l. Maestro Institute of Evolutionary Biology CSIC-Universitat Pompeu Fabra Barcelona Spain

Juvenile hormone （JH）, a sesquiterpenoid synthetized by the insect corpora allata （CA）, plays critical roles in metamorphosis and reproduction. Penultimate or last step of JH synthesis is catalyzed by juvenile hormone acid O-methyltransferase （JHAMT）. Here we report the cloning and expression analysis of the JHAMT orthologue in the cockroach, Blattella germanica （l.）（BgJHAMT）. BgJHAMT is mainly expressed in CA, with only expression traces in ovary. Three different isoforms, differing in the 3＇-UTR sequence, were identified. Isoform A shows between 35 and 65 times higher expression than B and C in CA from penultimate nymphal instar and adult females. RNAi-triggered knock down of BgJHAMT produces a dramatic reduction of JH synthesis, concomitant with a decrease of fat body viteUogenin expression and basal follicle length. BgJHAMT mRNA levels in CA of females along the gonadotrophic cycle parallel, with a slight advancement, JH synthesis profile. BgJHAMT mRNA levels were reduced in starved females and in females in which we reduced nutritional signaling by knocking down insulin receptor and target of rapamycin （TOR）. Results show that conditions that modify JH synthesis in adult B. germanica females show parallel changes of BgJHAMT mRNA levels and that the JH-specifie branch of the JH synthesis pathway is regulated in the same way as the mevalonate branch. Furthermore, we demonstrate that nutrition and its signaling through the insulin receptor and TOR pathways are essential for activating BgJHAMT expression, which suggests that this enzyme can be a checkpoint for the regulation of JH production in relation to nutritional status.

关键词： Blattella germanica corpora allata JHAMT juvenile hormone nutritionalsignaling

Dynamo saturation in rapidly rotating solar-type stars

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Research in Astronomy and Astrophysics 2015年第11期15卷 1801-1812页

作者： leonid l.Kitchatinov Serge v.Olemskoy Institute for Solar-Terrestrial Physics Pulkovo Astronomical Observatory

The magnetic activity of solar-type stars generally increases with stellar rotation rate. The increase, however, saturates for fast rotation. The Babcock-leighton mechanism of stellar dynamos saturates as well when the mean tilt angle of active regions approaches ninety degrees. Saturation of magnetic activity may be a consequence of this property of the Babcock-leighton mechanism. Stellar dynamo models with a tilt angle proportional to the rotation rate are constructed to probe this *** versions of the model- treating the tilt angles globally and using Joy＇s law for its latitude dependence- are considered. Both models show a saturation of dynamogenerated magnetic flux at high rotation rates. The model with latitude-dependent tilt angles also shows a change in dynamo regime in the saturation region. The new regime combines a cyclic dynamo at low latitudes with an（almost） steady polar dynamo.

关键词： saturation stellar latitude rotation rotating stars polar regime meridional consequence

ＣＯＭＰＬＥＸＩＴＹＯＦＬＡＲＧＥＴＩＭＥＢＥＨＡＶＩＯＵＲＯＦＥＶＯＬＵＴＩＯＮＥＱＵＡＴＩＯＮＳＷＩＴＨＢＯＵＮＤＥＤＤＡＴＡ

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Chinese Annals of Mathematics,Series B 2002年第2期23卷 293-310页

作者： J.l.vZQUEZ E.ZUAZUA Departamento de Matematicas Universidad AutonomaDepartamento de Matematica AplicadaUniversidadComplutense 28049MadridSpain28040 M

The authors study the asymptotic behaviour of solutions of the heat equation and a number of evolution equations using scaling techniques. It is proved that in the framework of bounded data stabilization need not occur and the general asymptotic behaviour is complex. This behaviour reflects for large times, even on compact sets, the complexity of the initial data at infinity.

关键词： Asymptotic behaviour Scaling Omega-limit Heat equation Hyperbolic conservation laws

New approach to formation of coatings on Mg-Mn-Ce alloy using a combination of plasma treatment and spraying of fluoropolymers

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Journal of Magnesium and Alloys 2022年第4期10卷 1033-1050页

作者： D.v.Mashtalyar K.v.Nadaraia I.M.Imshinetskiy S.l.Sinebryukhov S.v.Gnedenkov Institute of Chemistry FEB RAS 159 Pr.100-letiyaVladivostok 690022Russia Far Eastern Federal University 10 Ajax BayRussky IslandVladivostok 690922Russia

This paper presents a method of the formation of composite polymer-containing coatings on a Mg–Mn–Ce magnesium alloy by forming a ceramic-like layer using plasma electrolytic oxidation(PEO)and subsequent spraying superdispersed polytetrafluoroethylene *** coating composition and their morphological features were studied by SEM,EDS,GDOES,and *** presented data confirm the embedding of fluoropolymer in the PEO *** evaluation of the corrosion properties of the formed composite polymer-containing coatings indicates a decrease in the corrosion current density by more than 3 orders of magnitude in comparison with the base PEO *** incorporation of a fluoropolymer in a PEO layer by more than 32%increases the load value at which abrasion of the coating to the substrate occurs and reduces the wear of the coating by more than 27 fold in comparison with the PEO *** has been established that composite coatings possess hydrophobic properties:the value of the contact angle attains 152°.

关键词： Plasma electrolytic oxidation Polytetrafluoroethylene Composite coatings Corrosion Wear Superhydrophobicity

Emerging role of A-kinase anchoring protein 5 signaling in reward circuit function

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Neural Regeneration Research 2025年第10期20卷 2913-2914页

作者： William J.Flerlage Mark l.Dell’Acqua Brian M.Cox Fereshteh S.Nugent Uniformed Services University of the Health Sciences Department of Pharmacology and Molecular TherapeuticsBethesdaMDUSA Department of Pharmacology University of Colorado School of MedicineAnschutz Medical CampusAuroraCOUSA

There is a strong evidence supporting the hypothesis of synaptic dysfunction as a major contributor to neural circuit and network disruption underlying emotional and mood dysregulation in psychiatric disorders(Simmons et al.,2024).Diverse sets of distinct molecular signaling pathways converge on the synapse to regulate synaptogenesis,synaptic function,and synaptic plasticity in brain regions and circuits through complex interactions organized by numerous multivalent protein scaffolds,including the family of proteins known as A-kinase anchoring proteins(AKAPs).

关键词： function supporting

Deep bed filtration model for cake filtration and erosion

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Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 355-372页

作者： l.I.KUZMINA Y.v.OSIPOv A.R.PESTEREv Department of Applied Mathematics HSE UniversityMoscow 101000Russia Department of Computer Science and Applied Mathematics Moscow State University of Civil EngineeringMoscow 129337Russia

Many phenomena in nature and technology are associated with the filtration of suspensions and colloids in porous media. Two main types of particle deposition,namely, cake filtration at the inlet and deep bed filtration throughout the entire porous medium, are studied by different models. A unified approach for the transport and deposition of particles based on the deep bed filtration model is proposed. A variable suspension flow rate, proportional to the number of free pores at the inlet of the porous medium, is considered. To model cake filtration, this flow rate is introduced into the mass balance equation of deep bed filtration. For the cake filtration without deposit erosion,the suspension flow rate decreases to zero, and the suspension does not penetrate deep into the porous medium. In the case of the cake filtration with erosion, the suspension flow rate is nonzero, and the deposit is distributed throughout the entire porous medium. An exact solution is obtained for a constant filtration function. The method of characteristics is used to construct the asymptotics of the concentration front of suspended and retained particles for a filtration function in a general form. Explicit formulae are obtained for a linear filtration function. The properties of these solutions are studied in detail.

关键词： deep bed filtration cake filtration porous medium particle deposition and erosion analytical solution concentration front

Inhibition of M2 tumor-associated macrophages polarization by modulating the Wnt/β-catenin pathway as a possible liver cancer therapy method

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World Journal of Gastroenterology 2024年第40期30卷 4399-4403页

作者： vladislav v Tsukanov Julia l Tonkikh Edward v Kasparov Alexander v vasyutin Clinical Department of the Digestive System Pathology of Adults and Children Federal Research Center“Krasnoyarsk Science Center”of the Siberian Branch of the Russian Academy of SciencesScientific Research Institute of Medical Problems of the NorthKrasnoyarsk 660022Russia

The problem of liver cancer is becoming increasingly important due to the epi-demic of metabolic diseases and persistent high alcohol *** deter-mines great attention to the development and improvement of methods for early diagnosis and treatment of liver *** et al presented a study in the World Journal of Gastroenterology,in which they showed that the use of the traditional Chinese medicine Calculus bovis(CB)can suppress tumor growth in mice by inhibiting M2 tumor-associated macrophages(TAM)through modulating the activity of the Wnt/β-catenin *** interaction of CB components with the Wnt/β-catenin pathway,M2 TAM polarization,and tumor dynamics were studied using network pharmacology,transcriptomics,and molecular *** is now generally accepted that the polarization of TAM and the differentiation of the functions of M1 and M2 phagocytes are of great importance for the progression of *** is assumed that M2 TAM promote proliferation and migration of tumor *** to medicinally influence the Wnt/β-catenin pathway in order to modulate phagocyte polarization now belong to one of the most promising areas of immunotherapy of oncological ***,the work of the Chinese authors deserves attention and further development.

关键词： liver cancer Treatment Calculus bovis Tumor-associated macrophages M2 tumor Macrophage polarization Wnt/β-catenin pathway