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Gas-phase hydrogenation influence on defect behavior in titanium-based hydrogen-storage material

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Progress in natural Science:Materials International 2017年第1期27卷 105-111页

作者： Roman S.Laptev viktor n.kudiiarov Yuri S.Bordulev Andrey A.Mikhaylov Andrey M.Lider Department of General Physics Institute of Physics and Technology National Research Tomsk Polytechnic University

Titanium and its alloys are promising materials for hydrogen storage. However, hydrogen penetration accompanies the exploitation of hydrogen storage alloys. In particular, hydrogen penetration and accumulation in titanium alloys changes their mechanical properties. Therefore, the research works of such materials are mainly focused on improving the reversibility of hydrogen absorption-liberation processes, increasing the thermodynamic characteristics of the alloys, and augmenting their hydrogen storage capacity. In the process of hydrogenation-dehydrogenation, the formed defects both significantly reduce hydrogen storage capacity and can also be used to create effective traps for hydrogen. Therefore, the investigation of hydrogen interaction with structural defects in titanium and its alloys is very important. The present work, the hydrogen-induced formation of defects in the alloys of commercially pure titanium under temperature gas-phase hydrogenation（873 K） has studied by positron lifetime spectroscopy and Doppler broadening spectroscopy. Based on the evolution of positron annihilation parameters τ_f, τd, their corresponding intensities If, Idand relative changes of parameters S/S0and W/W0, the peculiarities of hydrogen interaction with titanium lattice defects were investigated in a wide range of hydrogen concentrations from 0.8at% to 32.0at%.

关键词： Titanium Hydrogen Lattice defects Positron annihilation Positron lifetime Doppler broadening

Stone–Wales defects in hexagonal boron nitride as ultraviolet emitters

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npj Computational Materials 2020年第1期6卷 169-175页

作者： Hanen Hamdi GergőThiering Zoltán Bodrog viktor Ivády Adam Gali Wigner Research Centre for Physics P.O.Box 49Budapest 1525Hungary Department of Physics Chemistry and BiologyLinköping UniversityLinköping SE-58183Sweden Budapest University of Technology and Economics Budafokiút 8.Budapest 1111Hungary

Many quantum emitters have been measured close or near the grain boundaries of the two-dimensional hexagonal boron nitride where various Stone–Wales defects *** show by means of first principles density functional theory calculations that the pentagon–heptagon Stone–Wales defect is an ultraviolet emitter and its optical properties closely follow the characteristics of a 4.08-eV quantum emitter,often observed in polycrystalline hexagonal boron *** also show that the square–octagon Stone–Wales line defects are optically active in the ultraviolet region with varying gaps depending on their density in hexagonal boron *** results may introduce a paradigm shift in the identification of fluorescent centres in this material.

关键词： Wales boron hexagonal

Poly(1-vinylimidazole) Prospects in Gene Delivery

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Chinese Journal of Polymer Science 2019年第7期37卷 637-645页

作者： Elena n.Danilovtseva Stanislav n.Zelinskiy viktor A.Pal'shin Gayathri Kandasamy Uma Maheswari Krishnan Vadim V.Annenkov Limnological Institute of the Siberian Branch of the Russian Academy of Sciences 3Ulan-Batorskaya St.P.O. Box 278Irkutsk 664033Russia Centre for nanotechnology &Advanced Biomaterials (CenTAB) School of Chemical and BiotechnologySASTRA UniversityThanjavur 613401 Tamil NaduIndia

Polymeric amines are being studied intensively as components of systems for gene delivery in genetic engineering and gene therapy of genetic disorders, including cancer. Despite remarkable achievements in the field, polymeric amines, such as polyethyleneimine, show some disadvantages. Strong interaction between the amine-containing polymer and nucleic acid hampers the release of nucleic acid in the cell cytoplasm. Amine groups can interact with the cell membrane which results in cell death. These limitations of polymeric amines stimulated an investigation of new structures for gene delivery. Imidazole-containing polymers have attracted attention as lesser basic substances, while they are able to interact with polymeric acids. Further development of imidazole-based gene delivery agents requires knowledge about some fundamental aspects of interaction between nucleic acids, and polymeric imidazoles. In this work, we studied the complexation of poly(1-vinylimidazole) and oligomeric DnA. We found that the number of active sites capable of binding with negatively charged phosphate groups is comparable with the number of protonated imidazole units in the case of high molecular weight polymer. The increase in polymer charge by 1-bromopropane quaternizating 1%?5% imidazole units or by decreasing the pH to 6.5?7 considerably increased the ability of poly(1-vinylimidazole) to interact with oligonucleotides. The pH sensitivity of this interaction is interesting for cancer gene therapy because the tumours have a lowered intercellular pH (stable oligonucleotide complex) and a higher extracellular pH which can lead to complex dissociation. Minimal critical length for complexation of quaternized poly(1-vinylimidazole) and DnA is below eight units which corresponds to polymers with amine groups. Fluorescence-tagged poly(1-vinylimidazole) samples were obtained and their potential for monitoring the polymer and polymer-oligonucleotide complex internalization into living cells was demo

关键词： Polymeric amines Oligonucleotides Fluorescence Poly(1-vinylimidazole) Gene delivery

Bioinspired Water-soluble Polymers with Grafted Polyamine Chains： Synthesis and Complexation with Oligonucleotides

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Chinese Journal of Polymer Science 2018年第10期36卷 1114-1122页

作者： Vadim V.Annenkov Uma Maheswari Krishnan viktor A.Pal'shin Stanislav n.Zelinskiy Gayathri Kandasamy Elena n.Danilovtseva Limnological Institute of the Siberian Branch of the Russian Academy of Sciences 3 Ulan-Batorskaya St. P.O. Box 278 Irkutsk 664033 Russia Centre for nanotechnology & Advanced Biomaterials (CenTAB) School of Chemical and Biotechnology SASTRA University Thanjavur - 613401 Tamil Nadu India

The siliceous frustules of diatom algae contain complex proteins known as silaffins, which consist of a peptide chain with grafted polyamine chains. These polyamines contain twenty or more nitrogen atoms with trimethylene groups between the nitrogens. We synthesized a set of polymers containing grafted long-chain polyamine fragments by using acryloyl chloride （ACh） polymers and activated acrylic acid copolymers as the starting materials. The new polymers contained 0.05 mol%-3.2 mol% of polyamine chains, which corresponded to 0.06-3.56 mmol·g- 1 amine groups. The new amine-containing polymers formed complexes with short （19-21-mer） deoxyribonucleic acid （DnA） and ribonucleic acid （RnA） strands, and these complexes penetrated into model yeast cells and A549 lung cancer cell. This study demonstrates the potential of these species based on long-chain polyamines to serve as novel gene delivery systems.

关键词： Polyamine Polymeric amine Gene delivery Acryloyl chloride

Supercritical fluids:Clean solvents for green chemistry

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Chinese Journal of Chemistry 1999年第3期17卷 212-222,201页

作者： POLIAKOFF Martyn GEORGE Michael W. HOWDLE Steven M. BAGRATASHVILI viktor n. 韩布兴闫海科 LaserChem Scientific Centre for Technological Lasers of the Russian Academy of Sciences Troitzk (Moscow Region) Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China Department of Chemistry The University of Nottingham Nottingham NG7 2RD England

Supercritical fluids are becoming increasingly attractive as environmentally acceptable replacement for organic solvents in chemical reactions and material processing. This paper highlights some of the properties of supercritical fluids, especially supercritical CO2, which offer particular advantages for the handling of polymers, metal complexes and the environmentally more friendly synthesis and manufacture of chemicals. The paper includes same of the researches in University of nottingham and a number of recent reviews which together provide a comprehensive introduction.

关键词： Green chemistry supercritical fluids chemical reaction water rapid expansion antisolvent

Distribution of secretory inhibitor of platelet microbicidal protein among anaerobic bacteria isolated from stool of children with diarrhea

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World Journal of Gastroenterology 2008年第35期14卷 5428-5431页

作者： Iuri B Ivanov viktor A Gritsenko Department of Human Microbiology Institute of Cellular and Intracellular SymbiosisRussian Academy of SciencesPionerskaya st.11Orenburg 460000Russia

AIM： To study the secretory inhibitor of platelet microbicidal protein （SIPMP） phenotypes of faecal anaerobic isolates from patients with diarrhea.METHODS： Faecal isolates of anaerobic bacteria （B. fragilis, n = 42; B. longum, n = 70; A. israelii, n = 21; E. lentum, n = 12） from children with diarrhea were tested. SIPMP production was tested by inhibition of platelet microbicidal protein （PMP） bioactivity against B. subtilis and was expressed as percentage of inhibition of PMP bactericidal activity.RESULTS： Among anaerobic isolates 80% of B. longum strains, 85.7% of A. israeli/strains, 50% of E. lentum strains and 92.86% of B. fragilis strains were SIPMP-positive. The isolated anaerobic organisms demonstrated SIPMP production at a mean level of 13.8% ± 0.7%, 14.7% ± 1.8%, 3.9% ± 0.9% （P 〈 0.05） and 26.8% ± 7.5% （P 〈 0.05） for bifidobacteria, A. israelii, E. lentum and B. fragilis, respectively.COnCLUSIOn： Data from the present study may have significant implications in understanding the pathogenesis of microecological disorders in the intestine, as well as for future improvement in the prevention and therapy of anaerobe-associated infections.

关键词： Platelet microbicidal protein Secretory inhibitor Anaerobic bacteria Intestine

Coexisting charge density wave and ferromagnetic instabilities in monolayer InSe

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npj Computational Materials 2022年第1期8卷 1101-1109页

作者： Evgeny A.Stepanov viktor Harkov Malte Rösner Alexander I.Lichtenstein Mikhail I.Katsnelson Alexander n.Rudenko CPHT CNRSEcole PolytechniqueInstitut Polytechnique de ParisF-91128PalaiseauFrance I.Institute of Theoretical Physics University of HamburgNotkestraße 922607HamburgGermany European X-Ray Free-Electron Laser Facility Holzkoppel 422869SchenefeldGermany Radboud University Institute for Molecules and Materials6525AJNijmegenThe Netherlands The Hamburg Centre for Ultrafast Imaging Luruper Chaussee 14922761HamburgGermany

Recently fabricated InSe monolayers exhibit remarkable characteristics that indicate the potential of this material to host a number of many-body *** this work,we systematically describe collective electronic effects in hole-doped InSe monolayers using advanced many-body *** this end,we derive a realistic electronic-structure model from first principles that takes into account the most important characteristics of this material,including a flat band with prominent van Hove singularities in the electronic spectrum,strong electron–phonon coupling,and weakly screened long-ranged Coulomb *** calculate the temperature-dependent phase diagram as a function of band filling and observe that this system is in a regime with coexisting charge density wave and ferromagnetic instabilities that are driven by strong electronic Coulomb *** regime can be achieved at realistic doping levels and high enough temperatures,and can be verified *** find that the electron–phonon interaction does not play a crucial role in these effects,effectively suppressing the local Coulomb interaction without changing the qualitative physical picture.

关键词： ferromagnetic charge wave

Passive vectoring of entomopathogenic fungus Beauveria bassiana among the wax moth Galleria mellonella larvae by the ectoparasitoid Habrobracon hebetor females

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Insect Science 2018年第4期25卷 643-654页

作者： Vadim Yu. Kryukov natalia A. Kryukova Maksim V. Tyurin Olga n. Yaroslavtseva viktor V. Glupov Institute of Systematics and Ecology of Animals Siberian Branch of Russian Academy of Science Novosibirsk Russia

Females of the ectoparasitoid Habrobracon hebetor attack and envenomate numerous host individuals during oviposition. The vectoring of the entomopathogenic fungus Beauveria bassiana during the adhesion stage by ectoparasitoid females among the wax moth larvae Galleria mellonella was explored under laboratory conditions. Vectoring occurred both from infected parasitoids to wax moth larvae and from infected to healthy wax moth larvae by parasitoids. The efficacy of vectoring in both cases was dose dependent. Parasitoid females were unable to recognize infected larvae in a labyrinth test. In addition, the presence of H. hebetor females significantly （1.5-13 fold） increased the mycoses level in clusters of G. mellonella, with 40% of the larvae infected with ftmgal conidia. Envenomation by H. hebetor increased conidia germination on the cuticles of the wax moth larvae by 4.4 fold. An enhanced germination rate （2 fold） was registered in the n- hexane epicuticular extract of envenomated larvae compared to that of healthy larvae. Both envenomation and mycoses enhanced the phenoloxidase （PO） activity in the integument of G. mellonella and, in contrast, decreased the encapsulation rate in hemolymphs. We hypothesize that changes in the integument property and inhibition of cellular immunity provide the highest infection efficacy of entomopathogenic fungi with H. hebetor.

关键词： Galleria mellonella immunity integuments mycoses parasitoid vectoring

Anti-apoptotic effect of retinoic acid on retinal progenitor cells mediated by a protein kinase A-dependent mechanism

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Cell Research 2007年第2期17卷 151-162页

作者： RomanKholodenko IrinaKholodenko viktor Sorokin AnnaTolmazova OlgaSazonova AntonBuzdin Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry 16/10 Miklukho-MaklayaMoscow 117997Russia Russian State Medical University Ostrovityanova 1Moscow 117312Russia

Retinal progenitor cells (RPCs) are neural stem cells able to differentiate into any normal adult retinal cell type,except for pigment epithelial cells. Retinoic acid (RA) is a powerful growth/differentiation factor that generallycauses growth inhibition,differentiation and/or *** this study,we demonstrate that RA not only affectsmouse RPC differentiation but also improves cell survival by reducing spontaneous apoptotic rate without affectingRPC *** enhanced cell survival was accompanied by a significant upregulation of the expression ofprotein kinase A (PKA) and several protein kinase C (PKC) *** of cells grown in RA-free mediawith 8-bromoadenosine3′,5′-cyclic monophosphate,a known activator of PKA,resulted in an anti-apoptotic effectsimilar to that caused by RA;whereas the PKA inhibitor n-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesul-fonamide dihydrochloride led to a significant (～32%) increase in *** contrast,treatment of RPCs withany of two PKC selective inhibitors,2,2′,3,3′,4,4′-hexahydroxy-1,1′-biphenyl-6,6′-dimethanol dimethyl ether andbisindolylmaleimide Ⅺ,led to diminished apoptosis;while a PKC activator,phorbol 12-myristate 13-acetate,in-creased *** and other data suggest that the effect of RA on RPC survival is mostly due to the increasedanti-apoptotic activity elicited by PKA,which might in turn be antagonized by *** a mechanism is a newexample of tight regulation of important biological processes triggered by *** the detailed mechanismsremain to be elucidated,we provide evidence that the pro-survival effect of RA on RPCs is not mediated by changedexpression of p53 or bcl-2,and appears to be independent of β-amyloid,Fas ligand,TnF-α,ganglioside GM1 andceramide C 16-induced apoptotic pathways.

关键词： retinal progenitor cells apoptosis retinoic acid protein kinase A protein kinase C