检索结果-南通市图书馆

Soil erosion: An important indicator for the assessment of land degradation neutrality in Russia

International Soil and Water Conservation Research 2020年第4期8卷 418-429页

作者： Petr Tsvmbarovich German Kust mikhail Kumani Valentin Golosov Olga Andreeva Institute of Geography RAS Russian Academy of SciencesMoscowRussia Lomonosov Moscow State University MoscowRussia Kursk State University KurskRussia

This review of soil erosion(SE)studies in Russia focuses on two main tasks:(i)ensuring the completeness and reliability of SE data in Russia,a large country(17.1 million km2)with a variety of natural and socio-economic causes of land degradation,(ii)assessing the possibility of including a SE indicator among the indicators of land degradation neutrality(LDN).A wide range of statistical,remote sensing,mathematical modeling *** results of scientific and field studies obtained at different levels were *** is asserted that in Russia the total area of eroded lands and those under erosion risk occupy more than 50%of all agricultural lands,whereas soil fertility of croplands decreased in Soviet time(from 1950s to 1980s)by 30-60%only due to water ***,recent scientific studies indicate a decrease in erosion rate and in the area of eroded land during the last 30-40 years as a result of abandonment of arable land and subsequent overgrown with natural *** climate change resulting in decrease of the depth of soil freezing,flow of spring runoff also adds to the decrease of soil *** SE indicator was suggested as an important complement to three global LDN *** national and subnational level,it can be interpreted through such indices as"Rate of soil loss"(ton ha-1 yr-1)and"Total soil loss"(1000 tons,in certain area during selected time period).At local level the set of indices can be wider and site-specific,including those obtained through remote sensing data by using the classifier of thematic applications of remote sensing technologies;the example was tested at the local site.

关键词： Russian Federation Soil erosion Land degradation neutrality

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

Transient expression of inactive RB in mesenchymal stem cells impairs their adipogenic potential and is associated with hypermethylation of the PPARγ2 promoter

引用

Genes & Diseases 2022年第1期9卷 165-175页

作者： mikhail Baryshev Nikolai Petrov Vladimir Ryabov Boris Popov Institute of Cytology Russian Academy of Sciences St.Petersburg4Tikhoretsky Av.194064St.PetersburgRussia Institute of Microbiology and Virology Riga Stradins UniversityRatsupites 5LV-1067RigaLatvia Developmental Therapeutics Branch National Cancer InstituteNational Institutes of HealthBethesdaMaryland 20892USA

The retinoblastoma gene product(pRb)is a chromatin-associated protein that can either suppress or promote activity of key regulators of tissue-specific *** found that twelve weeks after transfection of the exogenous active(ΔB/X andΔр34)or inactive(ΔS/N)forms of RB into the 10T1/2 mesenchymal stem cells and clonal selection not a single cell line did contain exogenous RB,despite being G-418 ***,the consequences of the transient production of exogenous RB had different effects on the cell ***ΔB/X andΔр34 cells transfected with active form of RB showed elevated levels of inducible adipocyte differentiation(AD).On the contrary,theΔS/N cells transfected with inactive RB mutant were insensitive to induction of AD associated with abolishing of expression of the PPARγ***,the PPARγ2 promoter in undifferentiatedΔS/N cells was hypermethylated,but all except−60 position CpG became mostly demethylated after cells exposure to *** conclude that while transient expression of inactive exogenous RB induces long term epigenetic alterations that prevent adipogenesis,production of active exogenous RBs results in an AD-promoting epigenetic *** results indicate that pRb is involved in the establishment of hereditary epigenetic memory at least by creating a methylation pattern of PPARγ2.

关键词： Adipogenic differentiation DNA methyltransferase 1 Mesenchymal stem cells MSCs RB Retinoblastoma susceptibility gene

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

Clarifying the influence of albumin on the initial stages of magnesium corrosion in Hank's balanced salt solution

引用

Journal of Magnesium and Alloys 2021年第3期9卷 805-817页

作者： Di Mei Cheng Wang Sviatlana V.Lamaka mikhail L.Zheludkevich Magnesium Innovation Centre-MagIC Institute of Materials ResearchHelmholtz-Zentrum GeesthachtGeesthacht 21502Germany Institute for Materials Science Faculty of EngineeringKiel UniversityKiel 24103Germany

The corrosion behavior of Mg,a promising biodegradable metallic material,in protein-containing pseudophysiological environment is still not fully *** this work,the influence of albumin on the corrosion behavior of commercially pure magnesium(CP Mg)is investigated during short-term tests in Hank’s Balanced Salt Solution(HBSS).This work focuses on the reactions at the Mg/medium interface from the perspective of the interactions among albumin,media components and *** evolution tests demonstrate that the physiological amount of albumin(40 g L^(-1))accelerates Mg corrosion in HBSS during the first few hours but slows down the degradation *** presence of albumin decreases the concentration of free Ca^(2+)in HBSS and delays formation of protective co-precipitation products on Mg *** evolution of local pH(differs from typically monitored bulk pH)near Mg/medium interface in albumincontaining HBSS is reported for the first *** of local and bulk pH values elucidates the pH buffering effect of albumin during the immersion *** on these results,adsorption,chelating and pH buffering effects are summarized as three important aspects of albumin influence on Mg ***,constant replenishment of medium components is shown to be an influential factor during the Mg corrosion tests.

关键词： Magnesium Corrosion Albumin Biodegradable Local pH

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

Elaboration of a conceptual solution for the development of the Arctic shelf from seasonally flooded coastal areas

引用

International Journal of Mining Science and Technology 2022年第1期32卷 113-119页

作者： Vladimir S.Litvinenko mikhail V.Dvoynikov Vladimir L.Trushko Saint-Petersburg Mining University Saint-Petersburg 199106Russia

Currently,construction of facilities in the Arctic is carried out on sand islands,but there are limitations for remote coastal *** restrictions are associated with the lack of quarries with construction sand in the immediate vicinity of the work site,as well as the risk of seasonal flooding of the *** article includes conceptual solutions for construction of modular piling in Arctic nearshore conditions,upon which drilling rigs and auxiliary equipment can be placed for the purpose of subsequent wildcatting,development and exploratory extended reach drilling wells(with measured depth about 15000 m).During the construction of the modular piling foundations,a mathematical simulation of the thermodynamic condition of the frozen ground was conducted,and the bearing capacity of the foundations was *** proposed solutions will solve these problems by constructing modular pile foundations and placing the necessary infrastructure on them,taking into account the distribution of loads during operation in seasonally flooded areas.

关键词： Drilling&drillholes Stress analysis Offshore engineering Infrastructure planning Geotechnical engineering Extended reach drilling

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

Role of intergenic interactions among folate cycle genes in the development of fetal growth retardation

引用

Reproductive and Developmental Medicine 2023年第1期7卷 32-37页

作者： Olesya Efremova Irina Ponomarenko mikhail Churnosov Department of Biomedical Disciplines Belgorod State University308015 BelgorodRussia

Objective:Metabolic disturbances in the folate cycle in mothers can lead to fetal growth retardation(FGR).This study was to analyze the role of intergenic interactions among maternal folate cycle genes in the development of ***:This case-control study recruited 365 women in the third trimester of pregnancy,including 122 FGR patients and 243 *** women were genotyped for 5 polymorphisms of the 4 folate cycle genes:MTR(rs1805087),MTRR(rs1801394),serine hydroxymethyl transferase(SHMT1;rs1979277),and TYMS(rs699517 and rs2790).The SNP×SNP interactions in the two-,three-,and four-locus models were analyzed using the multifactor dimensionality reduction method and a modification of it(the model-based multifactor dimensionality reduction method).Results:Four loci of maternal folate cycle genes(rs1805087 MTR,rs2790 TYMS,rs1801394 MTRR,and rs1979277 SHMT1)were associated with FGR in 3 significant models of single nucleotide polymorphism(SNP)×SNP interactions(two-,three-,and four-locus models)(P<0.05).The highest contribution to FGR was made by polymorphic loci rs1979277 SHMT1(1.70%of entropy),rs1805087 MTR(0.96%),and interactions between rs1979277 SHMT1×rs1805087 MTR(-1.11%)and rs1801394 MTRR×rs1979277 SHMT1(-0.64%).The four-locus maternal genotype combination AG rs1801394 MTRR×AA rs1805087 MTR×CT rs1979277 SHMT1×AG rs2790 TYMS was associated with an increased risk of FGR(β=2.69,P=0.012).FGR-associated SNPs were correlated with the expression of 16 genes(MTR,MTRR,SHMT1,ALKBH5,CTD-2303H24.2,ENOSF1,FAM106A,FOXO3B,LGALS9C,LLGL1,MIEF2,NOS2P2,RP11-806L2.6,SMCR8,TOP3A,and USP32P2)in various tissues and organs related to FGR ***:SNP×SNP interactions of maternal folate cycle genes(MTR,MTRR,SHMT1,and TYMS)are associated with the development of FGR.

关键词： Polymorphism Associations Fetal growth retardation Folate SNP×SNP interactions

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

Inhibition and enhancement of neural regeneration by chondroitin sulfate proteoglycans

引用

Neural Regeneration Research 2017年第5期12卷 687-691页

作者： Heikki Rauvala mikhail Paveliev Juha Kuja-Panula Natalia Kulesskaya Neuroscience Center University of Helsinki Helsinki Finland Department of Biological and Environmental Sciences University of Helsinki Helsinki Finland

The current dogma in neural regeneration research implies that chondroitin sulfate proteoglycans（CSPGs） inhibit plasticity and regeneration in the adult central nervous system（CNS）. We argue that the role of the CSPGs can be reversed from inhibition to activation by developmentally expressed CSPG-binding factors. Heparin-binding growth-associated molecule（HB-GAM; also designated as pleiotrophin） has been studied as a candidate molecule that might modulate the role of CSPG matrices in plasticity and regeneration. Studies in vitro show that in the presence of soluble HB-GAM chondroitin sulfate（CS） chains of CSPGs display an enhancing effect on neurite outgrowth. Based on the in vitro studies, we suggest a model according to which the HB-GAM/CS complex binds to the neuron surface receptor glypican-2, which induces neurite growth. Furthermore, HB-GAM masks the CS binding sites of the neurite outgrowth inhibiting receptor protein tyrosine phosphatase sigma（PTPσ）, which may contribute to the HB-GAM-induced regenerative effect. In vivo studies using two-photon imaging after local HB-GAM injection into prick-injury of the cerebral cortex reveal regeneration of dendrites that has not been previously demonstrated after injuries of the mammalian nervous system. In the spinal cord, two-photon imaging displays HB-GAM-induced axonal regeneration. Studies on the HB-GAM/CS mechanism in vitro and in vivo are expected to pave the way for drug development for injuries of brain and spinal cord.

关键词： CNS injury axon regeneration dendrite regeneration proteoglycans aggrecan glypican HB-GAM pleiotrophin PTEN

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

Difference in formation of plasma electrolytic oxidation coatings on MgLi alloy in comparison with pure Mg

引用

Journal of Magnesium and Alloys 2021年第5期9卷 1745-1760页

作者： Ting Wu Carsten Blawert Xiaopeng Lu Maria Serdechnova mikhail L.Zheludkevich Institute of Surface Science Helmholtz-Zentrum Hereon21502 GeesthachtGermany Shenyang National Laboratory for Materials Science Northeastern University110819 ShenyangChina Institute for Materials Science Faculty of EngineeringKiel UniversityKaiserstrasse 224143 KielGermany

In order to study the substrate lattice structure(Li addition)on the growth of plasma electrolytic oxidation(PEO)coatings,Mg Li alloy(11.36 wt.%of Li,cubic)and pure Mg(hexagonal)were treated under a pulsed direct PEO mode in a phosphate electrolyte for different periods of *** results revealed that the presence of Li and Li-rich phases in the cubic Mg alloy seems to be essential for the treatment result rather than the original lattice structure.A modified discharge behavior of Mg Li alloy finally led to a different microstructure of the *** unstable coatings of Mg Li alloy tended to dissolve rapidly though shared the similar composition to that of pure *** was incorporated only in the primary conversion products at the interface of coating/Mg *** spite of the advanced efficiency of energy input during processing,the more porous and thinner PEO coatings on the Mg Li alloy were less resistant to abrasion and corrosion.

关键词： Plasma electrolytic oxidation Magnesium lithium alloy Pure magnesium Microstructure

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

Simulation of Secondary Electron and Backscattered Electron Emission in A6 Relativistic Magnetron Driven by Different Cathode

引用

Plasma Science and Technology 2015年第1期17卷 64-70页

作者：刘美琴李博轮刘纯亮 Fuks mikhail Edl SCHAMILOGLU Key Laboratory of Physical Electronics and Devices of the Ministry of Education Xi'an Jiaotong University Department of Electrical and Computer Engineering University of New Mexico

Prticle-in-cell（PIC） simulations demonstrated that,when the relativistic magnetron with diffraction output（MDO） is applied with a 410 kV voltage pulse,or when the relativistic magnetron with radial output is applied with a 350 kV voltage pulse,electrons emitted from the cathode with high energy will strike the anode block *** emitted secondary electrons and backscattered electrons affect the interaction between electrons and RF fields induced by the operating modes,which decreases the output power in the radial output relativistic magnetron by about 15%（10%for the axial output relativistic magnetron）,decreases the anode current by about 5%（5%for the axial output relativistic magnetron）,and leads to a decrease of electronic efficiency by 8%（6%for the axial output relativistic magnetron）.The peak value of the current formed by secondary and backscattered current equals nearly half of the amplitude of the anode current,which may help the growth of parasitic modes when the applied magnetic field is near the critical magnetic field separating neighboring ***,mode competition becomes more serious.

关键词： secondary electron and backscattered electron emission relativistic magnetron mode competition critical magnetic field output power anode current electronic efficiency transparent cathode solid cathode

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

A Pressure Relaxation Closure Model for One-Dimensional, Two-Material Lagrangian Hydrodynamics Based on the Riemann Problem

引用

Communications in Computational Physics 2010年第5期7卷 927-976页

作者： James R.Kamm mikhail J.Shashkov Applied Physics Division Los Alamos National LaboratoryLos AlamosNM 87545USA Theoretical Division Los Alamos National LaboratoryLos AlamosNM 87545USA

Despite decades of development, Lagrangian hydrodynamics of strengthfree materials presents numerous open issues, even in one dimension. We focus on theproblem of closing a system of equations for a two-material cell under the assumptionof a single velocity model. There are several existing models and approaches, eachpossessing different levels of fidelity to the underlying physics and each exhibitingunique features in the computed solutions. We consider the case in which the changein heat in the constituent materials in the mixed cell is assumed equal. An instantaneous pressure equilibration model for a mixed cell can be cast as four equations infour unknowns, comprised of the updated values of the specific internal energy andthe specific volume for each of the two materials in the mixed cell. The unique contribution of our approach is a physics-inspired, geometry-based model in which theupdated values of the sub-cell, relaxing-toward-equilibrium constituent pressures arerelated to a local Riemann problem through an optimization principle. This approachcouples the modeling problem of assigning sub-cell pressures to the physics associated with the local, dynamic evolution. We package our approach in the frameworkof a standard predictor-corrector time integration scheme. We evaluate our model using idealized, two material problems using either ideal-gas or stiffened-gas equationsof state and compare these results to those computed with the method of Tipton andwith corresponding pure-material calculations.

关键词： Lagrangian hydrodynamics compressible flow multi-material flow pressure relaxation

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 localized Fourier collocation method for 2D and 3D elliptic partial differential equations:Theory and MATLAB code

引用

International Journal of Mechanical System Dynamics 2022年第4期2卷 339-351页

作者： Yan Gu Zhuojia Fu mikhail V.Golub Department of Computational Mathematics School of Mathematics and StatisticsQingdao UniversityQingdaoChina Department of Engineering Mechanics College of Mechanics and MaterialsHohai UniversityNanjingChina Department of Applied Mathematics Institute for MathematicsMechanics and InformaticsKuban State UniversityKrasnodarRussian Federation

A localized Fourier collocation method is proposed for solving certain types of elliptic boundary value *** method first discretizes the entire domain into a set of overlapping small subdomains,and then in each of the subdomains,the unknown functions and their derivatives are approximated using the pseudo-spectral Fourier collocation *** key idea of the present method is to combine the merits of the quick convergence of the pseudo-spectral method and the high sparsity of the localized discretization technique to yield a new framework that may be suitable for large-scale *** present method can be viewed as a competitive alternative for solving numerically large-scale boundary value problems with complex-shape *** numerical experiments involving Poisson,Helmholtz,and modified-Helmholtz equations in both two and three dimensions are presented to demonstrate the accuracy and efficiency of the proposed method.

关键词： meshless method collocation method Fourier basis functions large-scale problem

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

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：