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Stable non-synonymous substitutions on NS gene (NS1 and NS2 proteins) of Qinghai lake H5N1 influenza virus (Clade 2.2) after successive passages in Muscovy ducks

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Science China(Life Sciences) 2009年第9期52卷 847-853页

作者： GAO george F. Key Laboratory of Pathogenic Microbiology and Immunology of CAS (CASPMI) Institute of Microbiology Chinese Academy of Sciences (CAS) China-Japan Joint Laboratory of Molecular Immunology and Molecular Microbiology Institute of Microbiology Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences Beijing Institutes of Life Science Chinese Academy of Sciences

Although worldwide concern has been raised since the large-scale outbreak of highly pathogenic avian influenza in wild birds at Qinghai Lake,China in 2005,the factors responsible for the ability to kill waterfowl remain unclear. The why and how questions of the H5N1 virus species-jump into its reservoir host need to be answered. In this report we test the pathogenicity and adaptation of Qinghai Lake (Clade 2.2) isolate to Muscovy ducks for further understanding of this virus. The isolate was highly pathogenic in ducks and retained its high pathogenicity even after 20 generations of passage in ducks. During the process of serial passages,only the NS gene developed non-synonymous substitutions,which caused two mutations in NS1 protein (Val23Ala and Leu207Pro) and one in NS2 (Phe55Leu). These mutations persisted immutably through all subsequent passages and the pathogenicity remained high,implying that highly pathogenic H5N1 virus remains stable in aquatic birds through oral transmission. Although the exact functions of these mutations are not known,our results provide an important foundation for further understanding the characteristics of the Qinghai Lake isolates.

关键词： avian influenza virus H5N1 mutation NS1/2 serial passages

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Default polyfunctional T helper 1 response to ample signal 1 alone

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Cellular & Molecular Immunology 2021年第7期18卷 1809-1822页

作者： Luca Danelli Georgina Cornish Julia Merkenschlager george Kassiotis Present address:Laboratory of Molecular Immunology The Rockefeller UniversityNew YorkNY10065USA Department of Medicine Faculty of MedicineImperial College LondonLondonW21PGUK Retroviral Immunology The Francis Crick Institute1 Midland RoadLondonNW11ATUK

CD4^(+)T cells integrate well-defined signals from the T-cell receptor(TCR)(signal 1)and a host of costimulatory molecules(signal 2)to initiate clonal expansion and differentiation into diverse functional T helper(Th)***,our ability to guide the expansion of context-appropriate Th subsets by deploying these signals in vaccination remains *** cell-based vaccines,we selectively amplified signal 1 by exclusive presentation of an optimized peptide:MHC II(pMHC II)complex in the absence of classic *** to expectations,amplified signal 1 alone was strongly immunogenic and selectively expanded highaffinity TCR clonotypes,despite delivering intense TCR *** contrast to natural infection or standard vaccines,amplified signal 1,presented by a variety of professional and nonprofessional antigen-presenting cells(APCs),induced exclusively polyfunctional Th1 effector and memory cells,which protected against retroviral infection and tumor challenge,and expanded tumor-reactive CD4^(+)T cells otherwise rendered unresponsive in tumor-bearing ***,our findings uncover a default Th1 response to ample signal 1 and offer a means to selectively prime such protective responses by vaccination.

关键词： CD4 T cell priming T helper differentiation peptide-MHC II complex

Hybrid competitive Lotka–Volterra ecosystems with a hidden Markov chain

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Journal of Control and Decision 2014年第1期1卷 51-74页

作者： Ky Tran george Yin Department of Mathematics Wayne State UniversityDetroitMIUSA

This work concerns Lotka–Volterra models that are formulated using stochastic differential equations with *** from the existing formulations,the Markov chain that models random environments is *** such partially observed systems,we use Wonham’s filter to estimate the Markov chain from the observable evolution of the population,and convert the original system to a completely observable *** then show that the positive solution of our model does not explode in finite time with probability *** properties including stochastic boundedness,finite moments,sample path continuity and large-time asymptotic behaviour are also ***,stochastic permanence,extinction and feedback controls are also investigated.

关键词： Lotka-Volterra model hidden Markov chain partially observed system

REGULARITY AND RECURRENCE OF SWITCHING DIFFUSIONS

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Journal of Systems Science & Complexity 2007年第2期20卷 273-283页

作者： george YIN Chao ZHU Department of Mathematics Wayne State University Detroit Michigan 48202 U.S.A.

This work is concerned with switching diffusion processes, also known as regime-switching diffusions. Our attention focuses on regularity, recurrence, and positive recurrence of the underlying stochastic processes. The main effort is devoted to obtaining easily verifiable conditions for the aforementioned properties. Continuous-state-dependent jump processes are considered. First general criteria on regularity and recurrence using Liapunov functions are obtained. Then we focus on a class of problems, in which both the drift and the diffusion coefficients are ＂linearizable＂ with respect to the continuous state, and suppose that the generator of the jump part of the process can be approximated by a generator of an ergodic Markov chain. Sufficient conditions for regularity, recurrence, and positive recurrence are derived, which are linear combination of the averaged coefficients （averaged with respect to the stationary measure of the Markov chain）.

关键词： Recurrence regularity switching diffusion

Numerical Solutions for Optimal Control of Stochastic Kolmogorov Systems

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Journal of Systems Science & Complexity 2021年第5期34卷 1703-1722页

作者： YIN george WEN Zhexin QIAN Hongjiang NGUYEN Huy Department of Mathematics University of ConnecticutStorrsCT 06269USA School of Mathematics and Statistics Central South UniversityChangsha 410083China Department of Mathematics Wayne State UniversityDetroitMI 48202USA

This work is concerned with controlled stochastic Kolmogorov *** systems have received much attention recently owing to the wide range of applications in biology and *** with the basic premise that the underlying system has an optimal control,this paper is devoted to designing numerical methods for *** from the existing literature on numerical methods for stochastic controls,the Kolmogorov systems take values in the first *** is,each component of the state is *** work is designing an appropriate discrete-time controlled Markov chain to be in line with(locally consistent)the controlled *** authors demonstrate that the Kushner and Dupuis Markov chain approximation method still *** of the numerical scheme is proved under suitable conditions.

关键词： Controlled diffusion controlled Markov chain Kolmogorov equation numerical approximation

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Hepatocellular carcinoma in chronic hepatitis B patients under antiviral therapy

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World Journal of Gastroenterology 2013年第47期19卷 8822-8830页

作者： John Vlachogiannakos george Papatheodoridis Academic Department of Gastroenterology Athens University Medical SchoolLaiko General Hospital11527 AthensGreece

Patients with chronic hepatitis B are at increased risk of hepatocellular carcinoma(HCC),while the inhibition of viral replication can represent a reasonable target for HCC ***-αtherapy results in decreased HCC risk,which is more evident in patients with high baseline HCC *** majority of chronic hepatitis B patients are treated with a nucleos(t)ide analogue(NA)for several reasons including the nonsustained response after interferon-α.The effect of the first licensed and low genetic barrier NA,lamivudine,on HCC incidence,has been repeatedly ***,compared to no treatment,reduces the HCC incidence,which may increase again in cases with lamivudine *** data with the currently first-line NAs,entecavir and tenofovir,suggest that they also reduce the HCC *** treatment benefit in reduction of the HCC incidence is always greater in patients with high baseline HCC risk,particularly cirrhotics,and without virological remission under entecavir/***,the HCC risk is not eliminated even in the vast majority of patients who remain in virological remission under entecavir/***,patients at increased baseline HCC risk should continue to undergo HCC surveillance even if they have achieved complete long-term inhibition of viral replication and improvements in liver histology.

关键词： Chronic hepatitis B Hepatocellular carcinoma Interferon Lamivudine Adefovir Entecavir Tenofovir Virological remission Cirrhosis

MODELING EPHEMERAL GULLY EROSION FOR CONSERVATION PLANNING

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International Journal of Sediment Research 2005年第3期20卷 3-21页

作者： george R. FOSTER Mississippi National Sedimentation Laboratory Oxford Research Hydraulic Engineer (retired) USA USDA-Agricultural Research Service

This paper discusses the overland flow and concentrated flow systems that occur in most farm fields. Concentrated flow areas, which are distinct from overland flow areas, can be a major sediment source and are the main conduits that convey runoff and sediment from most farm fields. Ephemeral gully erosion, which occurs in concentrated flow areas, is similar to but differs from both rill and classical gully erosion. Concentrated flow areas occupy much of the flow path between the end of overland flow areas and defined stream channels. This paper describes the erosion and deposition processes that occur in concentrated flow areas and the effect of soil and cover management on these processes. Ephemeral gully erosion is not estimated with rill-interrill erosion prediction methods, which can result in major errors in estimates of sediment yield leaving farm fields. Much deposition can occur in concentrated flow areas resulting in sediment load leaving a farm field being much less than the sediment produced by rill-interrill and ephemeral gully erosion within the field. This paper describes model structure, topographic representation, and features of ephemeral gully erosion control practices needed in mathematical models used in conservation planning for farm fields.

关键词： Ephemeral gully erosion Concentrated flow area Overland flow area Mathematical model

Interfacial Strategies for Smart Slippery Surfaces

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Journal of Bionic Engineering 2020年第4期17卷 633-643页

作者： Glen McHale Rodrigo Ledesma-Aguilar Gary george Wells Smart Materials&Surfaces Laboratory Faculty of Engineering and EnvironmentNorthumbria UniversityNewcastle upon TyneNE18STUK

The problem of contact line pinning on surfaces is pervasive and contributes to problems from ring stains to ice *** we provide a single conceptual framework for interfacial strategies encompassing five strategies for modifying the solid-liquid interface to remove pinning and increase droplet *** biomimetic strategies are included,(i)reducing the liquid-solid interfacial area inspired by the Lotus effect,(ii)converting the liquid-solid contact to a solid-solid contact by the formation of a liquid marble inspired by how galling aphids remove honeydew,and(iii)converting the liquid-solid interface to a liquid-lubricant contact by the use of a lubricant impregnated surface inspired by the Nepenthes Pitcher *** further strategies are,(iv)converting the liquid-solid contact to a liquid-vapor contact by using the Leidenfrost effect,and(v)converting the contact to a liquid-liquid-like contact using slippery omniphobic covalent attachment of a liquid-like coating(SOCAL).Using these approaches,we explain how surfaces can be designed to have smart functionality whilst retaining the mobility of contact lines and ***,we show how droplets can evaporate at constant contact angle,be positioned using a Cheerios effect,transported by boundary reconfiguration in an energy invariant manner,and drive the rotation of solid components in a Leidenfrost heat *** conceptual framework enables the rationale design of surfaces which are slippery to liquids and is relevant to a diverse range of applications.

关键词： superhydrophobicity SLIPS liquid marbles leidenfrost SOCAL

A new model to describe composition and temperature dependence of thermal conductivity for solution phases in binary alloys

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Journal of Materials Science & Technology 2020年第24期59卷 72-82页

作者： Shiyi Wen Yuling Liu george Kaptay Yong Du State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China University of Miskolc MiskolcEgyetemvaros3515Hungary

Modelling temperature-and composition-dependent thermal conductivity in alloys is challengeable and is seldom studied *** the present work,a new model is developed to describe the temperature and concentration dependence of thermal conductivity for binary *** this new model,firstly thermal conductivity of pure metals was modelled as the function of temperature for each phase and each magnetic state by the corresponding physically sound ***,in order to describe the composition and temperature dependence of thermal conductivity for solid phases,the combination of the theories of Nordheim and Mott for electric conductivity of alloys with the Wiedemann-Franz law was ***,the reliability of the new model was verified by presently measured thermal conductivities for pure Co,Ni and Co-Ni alloys at 300,600,900 and 1100 K as well as for binary Al-Zn,Mg-Zn and U-Zr systems using the data taken from the *** calculated thermal conductivities can well reproduce the measured ones in one-phase regions of a series of Co-Ni *** thermal conductivity in a two-phase region of the Co-Ni system is reasonably predicted as *** is demonstrated that the new model can be utilized to evaluate the thermal conductivity over the whole investigated composition and temperature ranges for the first time and is expected to be extended to ternary and multicomponent systems by CALPHAD method,which contributes significantly to the development of computational design of materials.

关键词： Thermal conductivity Co-Ni alloys CALPHAD method Measurement Modelling

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