检索结果-南通市图书馆

Olefin Polymerization Behavior of Titanium(IV) Complexes with Fluorinated and Non-fluorinated Aliphatic Phenoxyimine Ligands

引用

Chinese Journal of Polymer science 2024年第1期42卷 52-62,I0007页

作者： Vladislav A.Tuskaev Kasim F.Magomedov svetlana Ch.Gagieva Dmitry A.Kurmaev Yulia V.Nelyubina Evgenii K.Golubev Maria D.Evseeva Viktor G.Vasil'ev Galina G.Nikiforova Mikhail I.Buzin vyacheslav s.bogdanov Boris M.Bulychev Department of Chemistry M.V.Lomonosov Moscow State UniversityMoscow 119992Russian Federation A.N.Nesmeyanov Institute of Organoelement Compounds Russian Academy of SciencesMoscow119991Russian Federation Enikolopov Institute of synthetic Polymer Materials Russian Academy of SciencesMoscow 117393Russian Federation

A series of Ti(Ⅳ) dichloride and dialkoxide com plexes with phenoxyimine ligands containing fluorinated and nonfluorinated aliphatic imine fragments have been *** molecular structures of complexes 1 and 4 were established by single-crystal X-ray diffraction *** complexes adopt a distorted octahedral coordination structure around the titanium atom and two oxygen atoms are situated in trans position while two nitrogen atoms and two outgoing ligands(Cl or iPrO) are situated in cis *** of activators(MMAO-12 and combinations Et_nAICl_(3-n)+Bu_(2)Mg) and outgoing ligand(Cl or iPrO) nature on the catalytic activity and properties of the resulting polymers was *** Ti complexes,despite the nature of the outgoing ligands(Cl or iPrO) in the presence of Al/Mg activators,was found to display a high ethylene polymerization activity in the range 1600-3830 kg_(polymer)·mol_(Ti)^(-1)·h^(-1)·atm^(-1) with a viscosity average molecular weight(M_v) value in the range 1.1×10~6-7.1×10~6 Dalton(Da).The resulting UHMWPE can be processed by a solventless method into high-strength and high-modulus oriented *** rheological characteristics of a polymer melt have been *** absence of a cross-over point did not allow to compare the values of the molecular weight distribution of polymers obtained on fluorinated and non-fluorinated pre-catalysts,however,the estimation of the entanglement density is in good agreement with the mechanical characteristics of oriented film *** activation with methylalumoxane,the activity of the com plexes decreased very significantly;however,a polymer with a molecular weight of about 12 million Da was *** the process of ethylene/octene-1 copolymerization,fluorine-containing precatalysts showed a clear advantage over non-fluorinated analogues both in activity and in comonomer content.

关键词： FI catalysts Titanium(IV) (Co)polymerization Al/Mg co-catalyst Ultra-high molecular weight polyethylene

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Gut Microbiota and Cytokine Profile in Cirrhosis

引用

Journal of Clinical and Translational Hepatology 2024年第8期12卷 689-700页

作者： Irina Efremova Roman Maslennikov Anna Kudryavtseva Anastasia Avdeeva George Krasnov Mikhail Diatroptov vyacheslav Bakhitov salekh Aliev Natalia sedova Maria Fedorova Elena Poluektova Oxana Zolnikova Nariman Aliev Anna Levshina Vladimir Ivashkin Department of Internal Medicine Gastroenterology and HepatologySechenov UniversityMoscowRussia Post-Genomic Research Laboratory Engelhardt Institute of Molecular BiologyRussian Academy of SciencesMoscowRussia V.A.Nasonova Research Institute of Rheumatology MoscowRussia Consultative and Diagnostic Center 2 of the Moscow Health Department MoscowRussia First Hospital surgery Department Pirogov Russian National Research Medical UniversityMoscowRussia Department of Clinical Laboratory Diagnostics FGBOU DPO“Russian Medical Academy of Continuing Professional Education of the Ministry of Health of the Russian Federation”MoscowRussia The Interregional Public Organization“scientific Community for the Promotion of the Clinical study” MoscowRussia

Background and Aims:Gut dysbiosis and abnormal cytokine profiles are common in *** study aimed to evaluate the correlations between ***:In the blood plasma of cirrhosis patients and controls,27 cytokines were examined using a multiplex *** plasma levels of nitrites(stable metabolites of the endothelial dysfunction biomarker nitric oxide)and lipopolysaccharide(LPs)were *** fecal microbiota was assessed by 16s rRNA gene ***:Levels of IL-1b,IL-2,IL-6,IL-13,IP-10,IFN-g,TNF-a,LPs,and nitrites were higher in cirrhosis patients than in controls,while levels of IL-4,IL-7,and PDGF-BB were *** LPs level was directly correlated with the levels of IL-1b,IL1-Ra,IL-9,IL-17,PDGF-BB,IL-6,TNF-a,and *** nitrite level was significantly directly correlated with the levels of TNF-a,GM-CsF,IL-17,and IL-12,and inversely correlated with the IL-7 ***-a levels were directly correlated with ascites severity and the abundance of Negativicutes,Enterobacteriaceae,Veillonellaceae,and Klebsiella,while inversely correlated with the abundance of Firmicutes,Clostridia,and ***-g levels were directly correlated with the abundance of Bacteroidaceae,Lactobacillaceae,Bacteroides,and Megasphaera,and inversely correlated with the abundance of Verrucomicrobiota,Akkermansiaceae,Coriobacteriaceae,Akkermansia,Collinsella,and ***-1b levels were directly correlated with the abundance of Comamonadaceae and Enterobacteriaceae and inversely correlated with the abundance of Marinifilaceae and ***-6 levels were directly correlated with the abundance of Enterobacteriaceae,hepatic encephalopathy,and ascites severity,and inversely correlated with the abundance of Peptostreptococcaceae,streptococcaceae,and ***:The abundance of harmful gut microbiota taxa and endotoxinemia directly correlates with the levels of proinflammatory cytokines.

关键词： Endotoxin Leaky gut Gut microbiome systemic inflammation Gut-liver axis Endotoxemia

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Change of photosensitizer fluorescence at its diffusion in viscous liquid flow

引用

Journal of Innovative Optical Health sciences 2016年第2期9卷 25-30页

作者： Valeriya s.Maryakhina vyacheslav V.Gun'kov Orenburg state University 13 Pobedy st. Orenburg 460018Russia

In this paper,the mathematical model of distribution of the injected compound in biological liquid flow has been *** is considered that biological liquid contains a few phases such as water,peptides and *** injected compound(for example,photosensitizer)can interact with peptides and *** the time,viscosity of the biological liquid depends on pathology present in *** obtained distribution of the compound connects on changes of its fluorescence spectra which are registered during fluorescent diagnostics of *** is obtained that the curves do not have monotonic *** is a sharp curves decline in the first few seconds after *** of curves rises after *** is especially pronounced for wavelength 590 nm and 580 nm(near the"transparency window"of biological tissues).Time of inflection point shifts from 8.4 s to 6.9 s for longer ***,difference between curves is little for di®erent viscosity means of the biological ***,additional pathology present in organism does not impact to the results of in vivo biomedical investigations.

关键词： Fluorescence diffusion biomedical diagnostics photosensitizer viscosity

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

submonolayer Eu superstructures—A class of 2D magnets

引用

Nano Research 2023年第1期16卷 1500-1506页

作者： Dmitry V.Averyanov Ivan s.sokolov Alexander N.Taldenkov Oleg E.Parfenov Andrey M.Tokmachev vyacheslav G.storchak National Research Center“Kurchatov Institute” Kurchatov Sq.1Moscow 123182Russia

Two-dimensional(2D)magnetic materials promise unconventional properties and quantum phases as well as advances in ultracompact *** of 2D magnets often reaches a single monolayer but in general can go beyond this limit,as demonstrated by 2D magnetism of submonolayer Eu superstructures coupled with *** question is whether the submonolayer magnetism constitutes a general ***,we demonstrate that regular Eu lattices form a class of 2D magnets displaying various structures,stoichiometries,and chemical *** synthesized and studied a set of Eu superstructures on Ge(001).Their magnetic properties are consistent with the emergence of a magnetic order such as ferro-or *** particular,control over the magnetic transition temperature by weak magnetic fields indicates the 2D nature of the *** together,Eu/Ge and Eu/si superstructures seed a nucleus of the research area addressing the emergence of magnetism in submonolayer chemical species.

关键词： two-dimensional(2D)magnetism submonolayer superstructure surface reconstruction germanium

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A class of high-mobility layered nanomaterials by design

引用

Journal of Materials science & Technology 2023年第33期164卷 179-187页

作者： Dmitry V.Averyanov Ivan s.sokolov Oleg E.Parfenov Alexander N.Taldenkov Oleg A.Kondratev Andrey M.Tokmachev vyacheslav G.storchak National Research Center “Kurchatov Institute” Kurchatov Sq.1Moscow 123182Russia

Design of materials with particular functional properties is indispensable albeit very *** and structural analogies can be helpful in this endeavor,especially when a particular combination of properties is sought *** aim is to bundle together 3 characteristics:high carrier mobility,magnetism,and scalability to nanomaterials in the form of a film–such a combination is particularly advantageous for ***,inspired by recent studies of MAl_(2)si_(2)and related compounds,we develop magnetic EuAl_(2)Ge_(2)and non-magnetic srAl_(2)Ge_(2)nanomaterials with high carrier *** syntheses employing sacrificial 2D templates result in epitaxial films of MAl_(2)Ge_(2)seamlessly integrated with *** syntheses are followed by a study of the atomic structure,magnetic and electron transport *** particular,the films demonstrate high carrier mobility,exceeding 10,000 cm^(2)V^(-1)s^(-1)in the case of EuAl_(2)Ge_(2),making the materials appealing for *** together,MAl_(2)Ge_(2)and MAl_(2)si_(2)form a class of high-mobility layered nanomaterials.

关键词： High carrier mobility Magnetism srAl_(2)Ge_(2) EuAl_(2)Ge_(2) Germanium

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

L-Norvaline, a new therapeutic agent against Alzheimer’s disease

引用

Neural Regeneration Research 2019年第9期14卷 1562-1572页

作者： Baruh Polis Kolluru D.srikanth vyacheslav Gurevich Hava Gil-Henn Abraham O.samson Drug Discovery Laboratory The Azrieli Faculty of MedicineBar-Ilan UniversitySafedIsrael Laboratory of Cell Migration and Invasion The Azrieli Faculty of MedicineBar-Ilan UniversitySafedIsrael Laboratory of Cancer Personalized Medicine and Diagnostic Genomics The Azrieli Faculty of MedicineBar-Ilan UniversitySafedIsrael

Growing evidence highlights the role of arginase activity in the manifestation of Alzheimer’s disease(AD).Upregulation of arginase was shown to contribute to *** of arginase activity appears to be a promising approach for interfering with the pathogenesis of ***,the enzyme represents a novel therapeutic *** this study,we administered an arginase inhibitor,L-norvaline(250 mg/L),for 2.5 months to a triple-transgenic model(3×Tg-AD)harboring Ps1M146V,APPswe,and tauP301L ***,the neuroprotective effects of L-norvaline were evaluated using immunohistochemistry,proteomics,and quantitative polymerase chain reaction ***,we identified the biological pathways activated by the ***,L-norvaline treatment reverses the cognitive decline in AD *** treatment is neuroprotective as indicated by reduced beta-amyloidosis,alleviated microgliosis,and reduced tumor necrosis factor transcription ***,elevated levels of neuroplasticity related postsynaptic density protein 95 were detected in the hippocampi of mice treated with ***,we disclosed several biological pathways,which were involved in cell survival and neuroplasticity and were activated by the *** these modes of action,L-norvaline has the potential to improve the symptoms of AD and even interferes with its *** such,L-norvaline is a promising neuroprotective molecule that might be tailored for the treatment of a range of neurodegenerative *** study was approved by the Bar-Ilan University Animal Care and Use Committee(approval No.82-10-2017)on October 1,2017.

关键词： dementia arginase inhibition arginine urea cycle microgliosis neuroinflammation cytokines tumor necrosis factor mTOR neurodegeneration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

some Aspects of Analysis of Dolphins’ Acoustical signals

引用

Open Journal of Acoustics 2011年第2期1卷 41-54页

作者： vyacheslav Ryabov 不详

Dolphins produce various types of sounds in a wide range of frequencies. Characteristics of some sounds till now have not been correctly registered, that influenced on interpretation of their functions. studying of the characteristics and functions of dolphins’ acoustical signals is the purpose of the present work. In this work the acoustical signals of two dolphins (Tursiops truncatus) were registered by two-channel system in the frequencies band up to 200 kHz at quasi-stationary position of the dolphins. The dolphins along with whistles are producing the packs of coherent and non-coherent broadband pulses. The waveform and spectrum of coherent pulses was invariable within a pack, but considerably varies from a pack to a pack. The waveform of each non-coherent pulse vary from a pulse to a pulse in each pack, therefore their spectrum also vary from a pulse to a pulse and have many extremums in the band of 6 - 200 kHz. It is very likely that the non-coherent pulses play a part of phonemes of a dolphin spoken language and the probing signals of dolphin’s non- coherent sonar. The use possibility of the signals by dolphins for communication and orientation was considered, as the signals apparently are bimodal. Results of the work have significance for further studying of the dolphin’s sonar and spoken language.

关键词： Dolphins Hearing sonar Acoustical signals Language Orientation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Relationship between Energy of Motion and D-Entropy in the Physics of Evolution

引用

World Journal of Mechanics 2023年第9期13卷 173-185页

作者： vyacheslav Mikhailovich somsikov ITPM Al-Farabi Kazakh National University Almaty Kazakhstan

The purpose of the paper is to substantiate the possibility of constructing the physics of the evolution of matter based on the fundamental laws of physics. It is shown how this can be done within the framework of an extension of classical mechanics. Its expansion is based on the motion equation of a structured body. The fundamental difference between this equation and Newton’s motion equation is that instead of a model of a body in the form of a material point, it uses a structured body in the form of a system of potentially interacting material points. To obtain this equation, the principle of symmetry dualism, new for classical mechanics, was used. According to this principle, the dynamics of a body are determined not only by the symmetries of space, as in the case of a structureless body, but also by its symmetries. Thanks to this derivation of the equation, it takes into account the fact that the work of external forces, in addition to changing the body’s motion energy, also changes its internal energy. This change occurs due to the body’s motion energy when it moves in a non-uniform field of forces. It is shown why the motion equation of a structured body is irreversible. Its irreversibility made it possible to introduce the concept of D-entropy into extended classical mechanics. It is defined as the value of the relative increase in the body’s internal energy due to the motion energy. The relationship between the values of motion energy and D-entropy in the process of matter evolution is considered. It is shown how this connection is realized during the transition from one hierarchical level of matter to the next level. As a result, it was possible to prove that the evolution of the hierarchical structure of matter is characterized by the relationship between D-entropy and the motion energy of elements at each of its hierarchical levels.

关键词： Dynamics symmetry Mechanics Energy Entropy Evolution

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Incubation of Pbse Thin Films in a Tin(Ⅱ) salt Aqueous solution:Modification and Ion-Exchange Reactions

引用

Journal of Materials science & Technology 2015年第8期31卷 790-797页

作者： Zinaida I.smirnova Larisa N.Maskaeva vyacheslav F.Markov Vladimir I.Voronin Mikhail V.Kuznetsov Ural Federal University(named after the First President of Russia B.N.Yeltsin) ul.Mira 19Yekaterinburg620002Russia Ural Institute of state Fire service of EMERCOM of Russia Yekaterinburgul.Mira 22620062Russia Institute of Metal Physics Ural BranchRussian Academy of Sciencesul.S.Kovalevskoy 18Yekaterinburg620041Russia Institute of solid state Chemistry Ural BranchRussian Academy of Sciencesul.Pervomaiskaya 91Yekaterinburg620990Russia

Topochemical ion-exchange reactions between solid micro- and nanostructured metal chalcogenides and aqueous salt solutions are generally used for formation of composite structures based on initial metal chalcogenides and products of their ion-exchange transformation. However, ion exchange has promises as a route to obtaining both composites and solid solutions based on the initial and the end chalcogenide phases. With the help of the ion-exchange technique, single-phase films of Phi xsnxse substitutional solid solutions with a tin content up to -2 at.%, which are promising for mid- and long-wavelength infrared radiation （IR） optoelectronics, have been obtained at the interface between Pbse poly- crystalline thin films and snCl2 aqueous solutions containing sodium citrate. It has been shown that the pH value and temperature of the reaction system play an important role in the ion-exchange process. Incubation of lead selenide （Pbse） films in a tin（II） salt aqueous solution also leads to their modification with oxygen-containing tin compounds to a depth of-3 nm. Differences in the film structure, such as changes in the coherent scattering region sizes and orientation of crystallites along the [220] direction, which arise during the contact with citrate-containing snCl2 solutions, have also been revealed. For the first time, an idea of the existence of a relatively wide reaction zone of an intragranular topochemical ion-exchange reaction in an aqueous solution, within which substitutional solid solutions can form in micro- and nanostructured systems, has been set forth.

关键词： Ion-exchange synthesis Thin films Lead selenide Tin selenide substitutional solid solutions Topochemical reaction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Tertiary montane origin of the Central Asian flora,evidence inferred from cpDNA sequences of Atraphaxis(Polygonaceae)

引用

Journal of Integrative Plant Biology 2014年第12期56卷 1125-1135页

作者： Ming-Li Zhang stewart C.sanderson Yan-Xia sun vyacheslav V.Byalt Xiao-Li Hao Key Laboratory of Biogeography and Bioresource in Arid Land Xinjiang Institute of Ecology and Geography the Chinese Academy of Sciences Institute of Botany the Chinese Academy of Sciences shrub sciences Laboratory Intermountain Research Station Forest Service US Department of Agriculture Provo UT 84601 USA Wuhan Botanical Garden the Chinese Academy of Sciences Komarov Botanical Institute Russian Academy of Sciences St Petersburg RU‐197376 Russia school of Life science Shihezi University

Atraphaxis has approximately 25 species and a distribution center in Central Asia. It has been previously used to hypothesize an origin from montane forest. We sampled 18 species covering three sections within the genus and sequenced five cpDNA spacers, atpB -rbcL, psbK -psbI, psbA -trnH, rbcL, and trnL -trnF. BEAsT was used to reconstruct phylogenetic relationship and time divergences, and s-DIVA and Lagrange were used, based on distribution area and ecotype data, for reconstruction of ancestral areas and events. Our results appear compatible with designation of three taxonomic sections within the genus. The generic stem and crown ages were Eocene, approximately 47 Ma, and Oligocene 27 Ma,respectively. The origin of Atraphaxis is confirmed as montane,with an ancestral area consisting of the Junggar Basin and uplands of the Pamir-Tianshan-Alatau-Altai mountain chains,and ancestral ecotype of montane forest. Two remarkable paleogeographic events, shrinkage of the inland Paratethys sea at the boundary of the late Oligocene and early Miocene, and the time intervals of cooling and drying of global climate from24（22） Ma onward likely facilitated early diversification of Atraphaxis, while rapid uplift of the Tianshan Mountains during the late Miocene may have promoted later diversification.

关键词： Allopatric diversification Atraphaxis biogeography Central Asia flora molecular clock montane origin phylogeny Polygonaceae

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：