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Peculiarities of Ethylene Polymerization Reactions with Bis(imino)pyridyl Complexes of CoCl_(2) and FeCl_(2)

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Chinese Journal of Polymer Science 2024年第4期42卷 492-500页

作者： Laura A.Rishina yury v.Kissin Svetlana S.Lalayan Artem A.Antonov vadim G.Krasheninnikov Alexander A.Gulin N.N.Semenov Federal Research Center for Chemical Physics Russian Academy of Sciences4 Kosygin St.Moscow119991Russia Department of Chemistry and Chemical Biology RutgersThe State University of New Jersey123 Bevier Rd.PiscatawayNJ08854USA Boreskov institute of Catalysis Russian Academy of Sciences5 Lavrentieva Prosp.Novosibirsk630090Russia

The article describes ethylene polymerization reactions with transition metal catalysts based on complexes of CoCl_(2) and FeCl_(2) with an N,N,N-tridentate ligand 2,6-bis[1-(2,6-dimethylphenylimino)ethyl]pyridine. The complexes are converted into polymerization catalysts by reacting them either with polymethylalumoxane (MAO) or with a combination of Al(C2H5)2Cl and Mg(C4H9)2 at an [Al]:[Mg] ratio of ~3. Both MAO-activated complexes readily polymerize ethylene at 35 ℃ with the formation of linear, low molecular weight polymers with a narrow molecular weight distribution. The same complexes, when activated with the Al(C2H5)2Cl-Mg(C4H9)2 combination, form multi-center catalysts and generate polyethylenes with a broad molecular weight distribution.

关键词： Ethylene polymerization Bis(imino)pyridyl complexes of CoCl_(2)and FeCl_(2) Molecular-weight distribution Polymer chain structure

Effect of Ta_(2)O_(5)nanoparticles on bioactivity,composition,structure,in vitro and in vivo behavior of PEO coatings on Mg-alloy

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Journal of Magnesium and Alloys 2024年第6期12卷 2360-2379页

作者： D.v.Mashtalyar i.M.imshinetskiy v.v.Kashepa K.v.Nadaraia M.A.Piatkova A.i.Pleshkova K.A.Fomenko A.Yu.Ustinov S.L.Sinebryukhov S.v.Gnedenkov institute of Chemistry Far Eastern BranchRussian Academy of SciencesVladivostok690022Russia Far Eastern Federal University Vladivostok690950Russia Regional Clinical Dermatovenerological Dispensary Vladivostok690033Russia

The present study investigates the physical and chemical characteristics,behavior in vitro and in vivo,and biocompatibility of coatings containing Ta_(2)O_(5),which are obtained by plasma electrolytic oxidation(PEO)on MA8 magnesium *** obtained coatings demonstrate in vivo biocompatibility and in vitro *** to the base PEO coating,the layers containing Ta_(2)O_(5)facilitate the development of apatite in simulated body fluid,suggesting that the inclusion of nanoparticles improves bioactivity of the *** was found that incorporation of Ta_(2)O_(5)nanoparticles increases roughness and porosity of the formed layers by increasing particle concentration in electrolytes for the PEO process contributing to sufficient soft tissue ingrowth in *** on in vivo studies,these coatings also provide favorable tissue response and minimal inflammatory reaction in comparison with the bare magnesium alloy due to protection of living tissues from deleterious corrosion events of magnesium implant such as local alkalization and intense hydrogen *** results obtained in the present study concluded biocompatibility,tissue integration of the PEO coatings containing Ta_(2)O_(5)nanoparticles making them a promising protective layer for biodegradable magnesium implants.

关键词： Plasma electrolytic oxidation Bioactive coatings Tantalum pentoxide Simulated body fluid(SBF) Apatite formation Histology

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

Antibacterial HA-coatings on bioresorbable Mg alloy

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Journal of Magnesium and Alloys 2024年第5期12卷 1965-1985页

作者： K.v.Nadaraia D.v.Mashtalyar M.A.Piatkova A.i.Pleshkova i.M.imshinetskiy M.S.Gerasimenko E.A.Belov v.v.Kumeiko D.N.Kozyrev K.A.Fomenko v.v.Mostovaya B.R.Torpanov A.R.Biktimirov i.S.Osmushko S.L.Sinebryukhov S.v.Gnedenkov institute of Chemistry FEB RAS 159 Pr.100-letiya VladivostokaVladivostok 690022Russia Far Eastern Federal University 10 Ajax BayRussky IslandVladivostok 690922Russia A.v.Zhirmunsky National Scientific Center of Marine Biology FEB RAS 17 St.PalchevskogoVladivostok 690041Russia Regional Clinical Dermatovenerological Dispensary 18 V St.GamarnikaVladivostok 690033Russia NMiC“Treatment and Rehabilitation Center” 3 Ivankovskoe highwayMoscow 125367Russia

in this study,a calcium-phosphate coating was formed on a Mg-Mn-Ce alloy by the plasma electrolytic oxidation(PEO).The antibiotic vancomycin,widely used in the treatment of infections caused by Staphylococcus aureus(***),was impregnated into the *** with vancomycin showed high bactericidal activity against *** mechanical and electrochemical properties of the formed coatings were studied,as well as in vitro cytotoxicity tests and in vivo tests on mature male rats were *** to SEM,EDS,XRD and XPS data,coatings had a developed morphology and contained hydroxyapatite,which indicates high *** analysis of roughness of coatings without and with vancomycin did not reveal any differences,confirming the high roughness of the *** electrochemical tests,an increase in corrosion resistance by more than two times after the application of PEO coatings was *** to the results of an in vivo study,after 28 days of the implantation of samples with calcium phosphate PEO coating and vancomycin,no signs of inflammation were observed,while an inflammatory reaction developed in the area of implantation of bare alloy,followed by *** release tests from the coatings show a sharp decrease in the concentration of the released antibiotic on day 7 and then a gradual decrease until day *** the experiment,no significant deviations in the condition and behavior of the animals were observed;clinical tests did not reveal a systemic toxic reaction.

关键词： Bioactive coatings Biocompatibility Mg alloy Plasma electrolytic oxidation Hydroxyapatite vancomycin

Photoluminescence,structural and antibacterial properties of co-dopedβ-Ca_(3)(PO_(4))_(2)-type phosphates Ca_(8)CuRE(PO_(4))_(7)(RE=Eu-Er)

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Journal of Rare Earths 2024年第9期42卷 1658-1668,I0002页

作者： ivan v.Nikiforov Ekaterina v.iliin Bogdan i.Lazoryak Sergey M.Aksenov Pavel v.Slukin Dina v.Deyneko Department of Chemistry Lomonosov Moscow State University119991MoscowRussia Laboratory of Arctic Mineralogy and Material Sciences Kola Science CentreRussian Academy of Sciences184209ApatityRussia Geological institute Kola Science CentreRussian Academy of Sciences184209ApatityRussia State Scientific Center of Applied Microbiology and Biotechnology of Rospotrebnadzor 24 Block A142279ObolenskRussia

Novel Ca_(8)CuRE(PO_(4))_(7)where RE^(3+)=Eu^(3+),Tb^(3+),Dy^(3+),Ho^(3+)and Er^(3+)were synthesized by a solid-state method in *** structures of the samples were characterized by powder X-ray diffraction using Rietveld refinement to determine the occupation of crystal *** samples are found to have a centrosymmetric structure with space group R3c,as shown by dielectric *** synthesized Ca_(8)CuRE(PO_(4))_(7)samples have multifunctional *** Cu^(2+)ions provide antibacterial properties,while the rare earth elements ions exhibit luminescence properties,and theβ-Ca_3(PO_(4))_(2)-type host is *** photoluminescence properties of RE^(3+)ions were studied and compared with other simmilar Ca_(8)MRE(PO_(4))_(7)phosphates,where M is a divalent *** photoluminescence intensity quenching in terms of energy transfer from RE^(3+)to Cu^(2+)is *** bioactive properties were studied in relation to antibacterial activity against *** and *** syntesized Ca_(8)CuRE(PO_(4))_(7)samples demonstrate very high and stable inhibition of bacteria *** correlation between crystal structure and properties is *** combining multiple approaches to the directio nal design of such materials,several important properties within a single chemical compound to achieve biovisualization and bioactive properties simultaneously can be combined.

关键词： β-Ca_(3)(PO_(4))_(2) Whitlockite-type structure Bioactive phosphates TCP Photoluminescence Rare earths

Apolipoprotein A-i binding protein-mediated neuroprotection in glaucomatous neuroinflammation and neurodegeneration

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Neural Regeneration Research 2025年第5期20卷 1414-1415页

作者： Sinwoo Hwang Seunghwan Choi Soo-Ho Choi Keun-Young Kim yury i.Miller Won-Kyu Ju Hamilton Glaucoma Center and Shiley Eye institute The Viterbi Family Department of OphthalmologyUniversity of California San DiegoLa JollaCAUSA Department of Medicine University of California San DiegoLa JollaCAUSA National Center for Microscopy and imaging Research Department of NeurosciencesUniversity of California San DiegoLa JollaCAUSA

Glaucoma is a multifactorial eye disorder that can cause vision loss and irreversible blindness,affecting individ uals aged 40 to 80 yea rs *** to the aging population,it is expected that the number of people affected by glaucoma will surpass 111 million by 2040 as the disease becomes more *** primarily contributes to optic nerve axon loss and the progressive degeneration of retinal ganglion cells (RGCs),subsequently leading to vision impairment.

关键词： irreversible pass primarily

Phase composition,conductivity,and sensor properties of cerium-doped indium oxide

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Nano Materials Science 2024年第2期6卷 193-200页

作者： M.i.ikim G.N.Gerasimov v.F.Gromov O.J.ilegbusi L.i.Trakhtenberg N.N.Semenov Federal Research Center for Chemical Physics of RAS MoscowRussia University of Central Florida OrlandoFLUSA Moscow institute of Physics and Technology(State University) DolgoprudnyMoscow RegionRussia Lomonosov Moscow State University MoscowRussia

The hydrothermal synthesis of in_(2)O_(3)and CeO_(2)–in_(2)O_(3)is investigated as well as the properties of sensor layers based on these *** the synthesis of in_(2)O_(3),intermediate products in(OH)_(3)and inOOH are formed,which are the precursors of stable cubic(c-in_(2)O_(3))and metastable rhombohedral(rh-in_(2)O_(3))phases,respectively.A transition from c-in_(2)O_(3)to rh-in_(2)O_(3)is observed with the addition of CeO_(2).The introduction of cerium into rh-in_(2)O_(3)results in a decrease in the sensor response to hydrogen,while it increases in composites based on c-in_(2)O_(3).The data on the sensor activity of the composites correlate with XPS results in which CeO_(2)causes a decrease in the concentrations of chemisorbed oxygen and oxygen vacancies in rh-in_(2)O_(3).The reverse situation is observed in composites based on c-in_(2)O_(3).Compared to in_(2)O_(3)and CeO_(2)–in_(2)O_(3)obtained by other methods,the synthesized composites demonstrate maximum response to H_(2)at low temperatures by 70–100℃,and have short response time(0.2–0.5 s),short recovery time(6–7 s),and long-term stability.A model is proposed for the dependence of sensitivity on the direction of electron transfer between in_(2)O_(3)and CeO_(2).

关键词： Cerium oxide indium oxide Nanocomposite Hydrothermal method Cubic phase Rhombohedral phase Sensor response Conductivity Hydrogen Response/recovery time

Design of Biologically Active Macromolecular Ligands and Their Luminescent Complexes with Terbium ions

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Chinese Journal of Polymer Science 2024年第5期42卷 604-611,I0007页

作者： Tatiana N.Nekrasova Andrei i.Fischer Natalia A.Nesterova Anatoliy v.Dobrodumov Anzhelika v.Garshinina Olga D.Shuvaeva Natalya v.Zakharova Evgenii F.Panarin institute of Macromolecular Compounds Russian Academy of Sciences31 Bolshoy pr.St Petersburg199004Russia Smorodintsev Research institute of influenza Russian Ministry of Health15/17 ul.prof.PopovaSt Petersburg197376Russia

Water-soluble copolymers of p-methacrylamidobenzoic acid(MABA)with neutral comonomers(N-vinylpyrrolidone(vP),N-methyl-N-vinylacetamide(MvAA),N-methacryloyl glucosamine(MAG))and anionic comononer sodium styrene sulfonate(NaSS)were synthesized by radical *** interactions between the prepared copolymers and Tb^(3+)ions in aqueous solutions were studied;the significant influence of chemical structure of a comonomer on luminescence intensity of Tb^(3+)complexes with the copolymers was *** luminescence intensity of Tb^(3+)complexes with the copolymers containing N-vinylamide units(vP,MvAA)is three times more intense than that observed for the complexes between Tb^(3+)and MAG-containing *** the case of NaSS-containing copolymers,the luminescence intensity is controlled by the values of binding constants between Tb^(3+)and MABA and the content of MABA units in a *** studied copolymers and their complexes with Tb^(3+)have low cytotoxicity and a pronounced antiviral activity against human respiratory syncytial virus.

关键词： Luminescence Water-soluble copolymers Lanthanide complexes Antiviral activity Cytotoxicity

Microstructure， electrochemical， wear and corrosive wear performance of laser-based powder bed fusion(lpbf) and wrought biomedical Ti-6Al-4v alloys

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Transactions of Nonferrous Metals Society of China 2024年

作者： A.G.Lekatou B.v.Efremenko v.Haoui v.G.Efremenko S.Emmanouilidou v.i.Zurnadzhy i.Petryshynets Yu.G.Chabak i.i.Sili Laboratory of Applied Metallurgy， Department of Materials Science and Engineering， School of Engineering， University of ioannina institute of Materials Science and Computing， University Research Center of ioannina (URCi) Pryazovskyi State Technical University， Department of Physics institute of Materials Research of Slovak Academy of Sciences

Wrought and laser powder bed fusion （LPBF） Ti-6Al-4v specimens were comparatively evaluated， with the objective to determine LPBF Ti-6-4’s suitability for biomedical applications. Testing included nanoindentation， cyclic polarization in simulated body fluid （SBF， 37 ℃ ）， and dry and SBF “Ball-on-Plate” sliding. Wrought Ti-6-4 exhibited a lamellar （α+β） microstructure， whereas LPBF displayed a fine-grained α'-martensite microstructure. LPBF Ti-6-4 demonstrated ～3% higher indentation modulus and ～32% higher hardness， while wrought Ti-6-4 showed ～8% higher plasticity. Both alloys exhibited low corrosion rates (10–5mA/cm2order) and true passivity (10–4mA/cm2order). No localized corrosion was observed in either alloy， except for occasional metastable pitting in the LPBF alloy. However， LPBF Ti-6-4 presented higher corrosion rate and passive current， ascribed to its martensitic structure. During dry sliding， LPBF Ti-6-4 exhibited ～14% lower volume loss compared to wrought Ti-6-4. Sliding in SBF increased volume losses for both alloys， with wear resistances nearly equalized， as the advantage of LPBF Ti-6-4 decreased due to more intensive wear-accelerated corrosion induced by the stressed martensite. Overall， the results demonstrate the suitability of LPBF Ti-6Al-4v for biomedical uses.

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