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Lead Induces Different Responses of Two Subpopulations of Phagocytes in the Holothurian Eupentacta fraudatrix

Journal of Ocean University of China 2018年第6期17卷 1391-1403页

作者： dolmatovA Lyu.mila S. dolmatov igor yu. Laboratory of Biochemistry V.I.Il'ichev Pacific Oceanological Institute Far Eastern Branch Russian Academy of Sciences Laboratory of Comparative Cytology National Scientific Center of Marine Biology Far Eastern Branch Russian Academy of Sciences Department of Cell Biology and Genetics Far Eastern Federal University

In view of increasing lead pollution(Pb^(2+)) of coastal waters, the compensatory abilities of holothurians need to be assessed. The goal of the work is to clarify the functional and phenotypical differences between two types of phagocytes(P1 and P2) in Eupentacta fraudatrix exposed to Pb(NO_3)_2. It has been shown that 2 mg L^(-1) lead exposure for 48 h increases the number of P2 phagocytes as compared to P1 cells, does not significantly affect cell viability in both P1 and P2 phagocyte fractions, and significantly enhances chromatin condensation in P2 but not in P1 phagocytes. A lead concentration of 4 mg L^(-1) increases the number of P1 phagocytes compared to that of P2 type, and does not change cell viability and chromatin condensation in P1 phagocytes. In the P2 type, it decreases cell viability and does not influence the level of apoptosis. The protection against lead-induced apoptosis is apparently mediated by the activities of antioxidant enzymes, especially glutathione S-transferase. The differences in labeling cell surface receptors of P1 and P2 phagocytes by plant lectins also indicate the specific phenotypic properties of these cells. The results clarify the potential and GSH-dependent mechanisms of immune adaptation in holothurians that have been shortly exposed to lead at concentrations close to the maximum environmentally relevant level in coastal waters. Additionally, P1 and P2 phagocytes are first shown to have different functions and phenotypes during the response to lead, which indicates the complexity of the phagocytic system in holothurians and contributes to understanding the immunity evolution.

关键词： amoebocytes antioxidant capacity apoptosis cell adaptation lead plant lectin con A DBA PNA SBA

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Four-wave mixing in a laser diode gain medium induced by the feedback from a high-Q microring resonator

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Photonics Research 2025年第1期13卷 59-68页

作者： DARIA M.SOKOL NIKITA yu.DMITRIEV DMITRY A.CHERMOSHENTSEV SERGEY N.KOPTYAEV ANATOLY V.MASALOV VALERY E.LOBANOV igor A.BILENKO ARTEM E.SHITIKOV Russian Quantum Center Moscow Institute of Physics and Technology (MIPT) Skolkovo Institute of Science and Technology Lebedev Physical Institute Russian Academy of Sciences Faculty of Physics M.V.Lomonosov Moscow State University

Laser diodes are widely used and play a crucial role in myriad modern applications including nonlinear optics and ***,we explore the four-wave mixing effect in a laser diode gain medium induced by the feedback from the high-Q microring *** phenomenon can be observed at a laser frequency scan close to the microresonator eigenfrequency,prior to the transition of the laser diode from a free-running to a self-injection locking *** effect opens up the possibility for generation of remarkably low-noise,stable,and adjustable microwave *** provide a detailed numerical study of this phenomenon proven with experimental results and demonstrate the generation of the signals in the GHz *** obtained results reveal the stability of such regime and disclose the parameter ranges enabling to achieve ***,our findings uncover,to our knowledge,a novel laser diode operation regime and pave the way for the creation of new types of chip-scale,low-noise microwave sources,which are highly demanded for diverse applications,including telecommunication,metrology,and sensing.

关键词： Four wave mixing

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Single‑Photon Sources Based on Novel Color Centers in Silicon Carbide P–I–N Diodes: Combining Theory and Experiment

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Nano-Micro Letters 2021年第5期13卷 192-203页

作者： igor A.Khramtsov Dmitry yu.Fedyanin Laboratory of Nanooptics and Plasmonics Center for Photonics and 2D MaterialsMoscow Institute of Physics and Technology141700DolgoprudnyRussian Federation

Point defects in the crystal lattice of SiC,known as color centers,have recently emerged as one of the most promising single-photon emitters for non-classical light ***,the search for the best color center that satisfies all the requirements of practical applications has only just *** color centers in SiC have been recently discovered but not yet ***,it is extremely challenging to understand their optoelectronic properties and evaluate their potential for use in practical single-photon ***,we present a theoretical approach that explains the experiments on single-photon electroluminescence(SPEL)of novel color centers in SiC p-i-n diodes and gives the possibility to engineer highly efficient single-photon emitting diodes based on ***,we develop a novel method of determining the electron and hole capture cross sections by the color center from experimental measurements of the SPEL rate and second-order *** other methods,the developed approach uses the experimental results at the single defect level that can be easily obtained as soon as a single-color center is identified in the i-type region of the SiC p-i-n diode.

关键词： Color centers Electron capture cross section Single-photon emitting diodes Single-photon electroluminescence Charge state control

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Hecke-Langlands Duality and Witten’s Gravitational Moonshine

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Journal of High Energy Physics, Gravitation and Cosmology 2021年第2期7卷 391-402页

作者： igor yu. Potemine Institut de Mathématiques Université Paul Sabatier Toulouse France

The purpose of this research is to give a dual description of conformal blocks of d=2 rational CFT (conformal field theory) in terms of Hecke eigenforms and eigensheaves. In particular, partition functions, conformal characters and lattice theta functions may be reconstructed from the action of Hecke operators. This method can be applied to: 1) rings of integers of Galois number fields equipped with the trace (or anti-trace) form;2) root lattices of affine Kac-Moody algebras and WZW-models;3) minimal models of Belavin-Polyakov-Zamolodchikov and related d=2 spin-chain/lattice models;4) vertex algebras of Leech and Niemeier lattices and others. We also use the original Witten’s idea to construct the 3-dimensional quantum gravity as the AdS/CFT-dual of c=24 Monster vertex algebra of Frenkel-Lepowsky- Meurman. Concerning the geometric Langlands duality, we use results of Beilinson-Drinfeld, Frenkel-Ben-Zvi, Gukov-Kapustin-Witten and many others (cf. references). The main new result in this paper is the construction of number-theoretical lattice vertex superalgebras in Section 5 and applications to conformal field theories and quantum gravity.

关键词： Conformal Field Theory Modular Invariance Quantum Gravity S-Duality Vertex Algebra

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Hyperverse, 5-Dimensional Gravity and Multiverses as Nested Gogberashvili Shells

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Journal of High Energy Physics, Gravitation and Cosmology 2022年第4期8卷 983-989页

作者： igor yu. Potemine Institut de Mathématiques Université Paul Sabatier Toulouse France

We consider the Hyperverse as a collection of multiverses in 5-dimensional spacetime with gravitational constant G. Each multiverse in our simplified model is a bouquet of nested spherical Gogberashvili shells. If gk is the gravitational constant of a thin shell Sk and εk, its thickness then G ~ εkgk. The physical universe is supposed to be one of those shells inside the local nested bouquet called Local Multiverse. We relate this construction to Robinson-Trautman metrics describing expanding spacetimes with spherical gravitational waves. Supermassive astronomical black holes, located at cores of elliptic/spiral galaxies, are also conjecturally described within this theory. Our constructions are equally consistent with the modern theory of cosmological coupling.

关键词： 5-Dimensional Gravity Black Hole Multiverse Spherical Shell

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Multiverse/Hyperverse Models: (4 + 1)-Dimensional Landscape (Black Saturns, Bousso-Hawking Nucleation, Gogberashvili Multiverses, Schwarzschild-De Sitter Nurseries) and a (3 + 1)-Dimensional Model for Dark Energy

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Journal of High Energy Physics, Gravitation and Cosmology 2024年第4期10卷 1866-1877页

作者： igor yu. Potemine Werner Krause Institut de Mathmatiques Universit Paul Sabatier Toulouse France Independent Researcher Berlin Germany

We consider the Hyperverse as a collection of multiverses in a (4 + 1)-dimensional spacetime with gravitational constant G. Multiverses in our model are bouquets of thin shells (with synchronized intrinsic times). If gis the gravitational constant of a shell Sand εits thickness, then G~εg. The physical universe is supposed to be one of those thin shells inside the local bouquet called Local Multiverse. Other remarkable objects of the Hyperverse are supposed to be black holes, black lenses, black rings and (generalized) Black Saturns. In addition, Schwarzschild-de Sitter multiversal nurseries can be hidden inside those Black Saturns, leading to their Bousso-Hawking nucleation. It also suggests that black holes in our physical universe might harbor embedded (2 + 1)-dimensional multiverses. This is compatible with outstanding ideas and results of Bekenstein, Hawking-Vaz and Corda about “black holes as atoms” and the condensation of matter on “apparent horizons”. It allows us to formulate conjecture 12.1 about the origin of the Local Multiverse. As an alternative model, we examine spacetime warping of our universe by external universes. It gives data for the accelerated expansion and the cosmological constant Λ, which are in agreement with observation, thus opening a possibility for verification of the multiverse model.

关键词： 5-Dimensional Gravity Black Hole Black Saturn Cosmological Constant Dark Energy Multiverse Spacetime Warping Thin Shell

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Esterified cellulose nanocrystals for reinforced epoxy nanocomposites

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Progress in Natural Science:Materials International 2022年第3期32卷 328-333页

作者： Lachlan Thompson Mostafa Nikzad igor Sbarski Aimin yu Department of Chemistry and Biotechnology Swinburne University of Technology

The surface of cellulose nanocrystals(CNCs) was successfully modified with methacryloyl chloride to create esterified CNCs(M/CNCs). The modification was confirmed by Fourier Transfer Infra-Red Spectroscopy, X-ray Photoelectron Spectroscopy and Zeta potential measurement. With increased surface hydrophobicity, this modified CNC material exhibited improved compatibility with organic network. When used as a filler to be incorporated into a model epoxy resin, TEM results indicated that M/CNCs particles dispersed well in the epoxy network. It was observed that the inclusion of the M/CNCs had an impact upon the heat flow for the curing of the epoxy nanocomposite, leading to an improvement in the storage modulus when tested via dynamic mechanical analysis.

关键词： Cellulose nanocrystals Epoxy nanocomposites Surface modification

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Continuous wafer-scale graphene on cubic-SiC（O01）

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Nano Research 2013年第8期6卷 562-570页

作者： Alexander N. Chaika Olga V. Molodtsova Alexei A. Zakharov Dmitry Marchenko Jaime Sanchez-Barrig Andrei Varykhalov igor V. Shvets Victor yu. Aristov Institute of Solid State Physics RAS Chemogolovka Moscow District 142432 Russia Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) School of Physics Trinity College Dublin 2 Ireland HASYLAB at DESY D-22607 Hamburg Germany MAX-lab Lund University Box 118 22100 Lund Sweden Helmholtz-Zentrum Berlin für Materialien und Energie D- 12489 Berlin Germany

The atomic and electronic structure of graphene synthesized on commercially available cubic-SiC（001）/Si（001） wafers have been studied by low energy electron microscopy （LEEM）, scanning tunneling microscopy （STM）, low energy electron diffraction （LEED）, and angle resolved photoelectron spectroscopy （ARPES）. LEEM and STM data prove the wafer-scale continuity and uniform thickness of the graphene overlayer on SIC（001）. LEEM, STM and ARPES studies reveal that the graphene overlayer on SIC（001） consists of only a few monolayers with physical properties of quasi-freestanding graphene. Atomically resolved STM and micro-LEED data show that the top graphene layer consists of nanometer-sized domains with four different lattice orientations connected through the 〈110〉-directed boundaries. ARPES studies reveal the typical electron spectrum of graphene with the Dirac points close to the Fermi level. Thus, the use of technologically relevant SiC（001）/Si（001） wafers for graphene fabrication repre-sents a realistic way of bridging the gap between the outstanding properties of graphene and their applications.

关键词： graphene cubic-SiC(001) STM ARPES LEEM LEED

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Influence of Pt/Pd state on ceria-based support in CO oxidation

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Journal of Rare Earths 2023年第12期41卷 1963-1968,I0005页

作者： igor V.Zagaynov Elena yu.Liberman Alexander V.Naumkin A.A.Baikov Institute of Metallurgy and Materials Science MoscowRussia D.I.Mendeleev University of Chemical Technology of Russia MoscowRussia A.N.Nesmeyanov Institute of Organoelement Compounds MoscowRussia

Noble metal(M:Pt,Pd,PtPd) supported on ceria system catalysts were *** oxidized and reduced forms of the active component were examined in CO *** catalysts become more active after a reduction pretreatment,which shifts the temperature of CO *** of the data obtained from characterization techniques indicates that the strong interaction of metal ions with the support prevent the reduction of the initial MO_(x)to metallic *** formation of M-ceria interfaces efficiently boosts the oxygen activation during CO oxidation,leading to the formation of chemisorbed O on M and the regeneration of the ceria lattice oxygen,thus greatly improving the catalytic performance.

关键词： Ceria Platinum Palladium CO oxidation Rare earths

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Building African Ecosystem Research Network for Sustaining Local Ecosystem Goods and Services

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Chinese Geographical Science 2015年第4期25卷 414-425页

作者： Armand Sedami igor YEVIDE WU Bingfang yu.Xiubo LI Xiaosong LIU yu.LIU Jian Key Lab of Digital Earth Sciences Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences International Ecosystem Management Partnership (IEMP) United Nations Environment Programme (UNEP)

A new form of producing and sharing knowledge has emerged as an international(United States of America,Asia,and Europe) research collaboration,known as the Long-Term Ecological Research(LTER) *** Africa boasts rich biodiversity,including endemic species,it lacks the long-term initiatives to underpin sustainable biodiversity *** present,climate change may exacerbate hunger and poverty concerns in addition to resulting in ecosystem degradation,land use change,and other threats in ***,ecosystem monitoring was suggested to understanding the effects of climate change and setting strategies to mitigate these *** paper aimed to investigate ecosystem monitoring ground sites and address their coverage gaps in Africa to provide a foundation for optimizing the African Ecosystem Research Network(AERN) ground *** geographic coordinates and characteristics of ground sites-based ecosystem monitoring were collected from various networks aligned with the LTER implementation in ***,climatic data and biodiversity distribution maps were retrieved from various *** data were used to assess the size of existing ground sites and the gaps in description,ecosystems and *** results reveal that there were 1089 sites established by various *** these sites,30.5%,27.5%,and 28.8% had no information of area,year of establishment,current status,***,68.0% of them had an area equal to or greater than 1 *** were created progressively over the course of the years,with 68.9% being created from 2000 to *** date,only 41.5% of the sites were *** sites were scattered across Africa,but they were concentrated in Eastern and Southern *** unbalanced distribution pattern of the sites left Central and Northern Africa hardly covered,and many unique ecosystems in Central Africa were not *** sustain these sites,the AERN should be based on operational sites,seeking secur

关键词： ecosystem monitoring Long-Term Ecological Research(LTER) biodiversity ground site gap analysis network Africa

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