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Stellar structure model in hydrostatic equilibrium in the context of f(R)-gravity

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Research in Astronomy and Astrophysics 2017年第12期17卷 31-40页

作者： raíla Andr Gilberto M.Kremer Departamento de Fisica Universidade Federal do Parana81531-980 CuritibaBrazil Manipal Centre for Natural Sciences Manipal UniversityManipal 576104India

In this work we present a stellar structure model from the f（R）-gravity point of view capable of describing some classes of stars（white dwarfs, brown dwarfs, neutron stars, red giants and the Sun）. This model is based on f（R）-gravity field equations for f（R） = R ＋ f2R2, hydrostatic equilibrium equation and a polytropic equation of state. We compare the results obtained with those found by Newtonian theory. It has been observed that in these systems, where high curvature regimes emerge,stellar structure equations undergo modifications. Despite the simplicity of this model, the results are satisfactory. The estimated values of pressure, density and temperature of the stars are within those determined by observations. This f（R）-gravity model has proved to be necessary to describe stars with strong fields such as white dwarfs, neutron stars and brown dwarfs, while stars with weaker fields, such as red giants and the Sun, are best described by Newtonian theory.

关键词： cosmology:theory stars:general massive brown dwarfs white dwarfs neutron

Periodic Solutions of Evolution Variational Inequalities—a Method of Guiding Functions

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Chinese Annals of Mathematics,Series B 2009年第3期30卷 261-272页

作者： Samir ADLY Daniel GOELEVEN Michel THra Département de Math'ematiques et Informatique Laboratoire XLIM(Unité Mixte 6172 du CNRS)Université de Limoges123 Avenue A.Thomas87060 Limoges CedexFrance. Laboratoire d' Informatique et de Mathématiques Université de La Réunion97400 Saint-DenisFrance.

This paper focuses on a part of the presentation given by the third author at the Shanghai Forum on Industrial and Applied Mathematics(Shanghai 2006).It is related to the existence of a periodic solution of evolution ... 详细信息

关键词： Variational inequality Differential inclusion Topological degree Guiding function Periodic solution

ROBUST HIGH ORDER CONVERGENCE OF AN OVERLAPPING SCHWARZ METHOD FOR SINGULARLY PERTURBED SEMILINEAR REACTION-DIFFUSION PROBLEMS

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Journal of Computational Mathematics 2013年第5期31卷 509-521页

作者： S. Chandra Sekhara ra~ Sunil Kumar Department of Mathematics Indian Institute of Technology Delhi Hauz khas New Delhi-110016 India

In this article we propose an overlapping Schwarz domain decomposition method for solving a singularly perturbed semilinear reaction-diffusion problem. The solution to this problem exhibits boundary layers of width O（√ε ln（1/√ε）） at both ends of the domain due to the presence of singular perturbation parameter ε. The method splits the domain into three overlapping subdomains, and uses the Numerov or Hermite scheme with a uniform mesh on two boundary layer subdomains and a hybrid scheme with a uniform mesh on the interior subdomain. The numerical approximations obtained from this method are proved to be almost fourth order uniformly convergent （in the maximum norm） with respect to the singular perturbation parameter. Furthermore, it is proved that, for small ε, one iteration is sufficient to achieve almost fourth order uniform convergence. Numerical experiments are given to illustrate the theoretical order of convergence established for the method.

关键词： Singular perturbation Semilinear reaction-diffusion Overlapping Schwarzmethod Robust convergence Numerov scheme.

Effect of high shear homogenization on quality characteristics of bael fruit pulp

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Food Quality and Safety 2022年第1期6卷 81-92页

作者： Meenatai G.Kamble anurag Singh Pramod Kumar Prabhakar Murlidhar Meghwal Sukh Veer Singh Ajay V.Chinchkar Department of Food Science and Technology National Institute of Food Technology Entrepreneurship and Management(NIFTEM)SonipatHaryana-131028India

Response surface methodology was used to investigate the influence of high shear homogenization speed(A:3000-12000 r/min)and processing time(B:30-120 min)on bael fruit pulp quality *** experimental results were best fitted in the suggested quadratic model to delineate and envision the responses in terms of color(values of L^(*),meaning brightness to blackness,1oo-0;a^(*),meaning green-a^(*)to red+a^(*);and b^(*),meaning blue-b^(*)to yellow+b),total soluble solids,ascorbic acid,viscosity,andβ-carotene content with the highest coefficients of determination(R2)ranging from 0.80 to ***(Praction effect of homogenization showed a significant difference in a^(*)value and total soluble solid content of the *** best homogenization conditions were determined via multiple response optimization as 10682 r/min speed and 43.18 min process *** quality parameters of the pulp at optimized conditions were observed as L^(*)15.35,a^(*)4.51,b^(*)10.25,ascorbic acid 18.64 mg/100 g,viscosity 5349 cP,andβ-carotene 4.14μg/100 *** addition,total phenolic content,flavonoid content,and antioxidant content of homogenized bael fruit pulp was found to significantly(Prategy could be used in fruit processing industries to process highly fibrous fruits and nonuniform-textured fruit pulptoavoid sedimentation whileretaining functionality.

关键词： Aegle marmelos L. underutilized fruit viscosity bioactive compounds color values

Future prospectives for the management of chronic hepatitis B

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World Journal of Gastroenterology 2007年第18期13卷 2554-2567页

作者： WF Leemans HLA Janssen ra de Man Department of Gastroenterology & Hepatology Erasmus MC University Medical Center Rotterdam The Netherlands

Chronic hepatitis B virus infection affects about 400 million people around the globe and causes approximately a million deaths a year. Since the discovery of interferon-α as a therapeutic option the treatment of hepatitis B has evolved fast and management has become increasingly complicated. The amount of viral replication reflected in the viral load （HBV-DNA） plays an important role in the development of cirrhosis and hepatocellular carcinoma. The current treatment modalities for chronic hepatitis B are immunomodulatory （interferons） and antiviral suppressants （nucleoside and nucleotide analogues） all with their own advantages and limitations. An overview of the treatment efficacy for both immunomodulatory as antiviral compounds is provided in order to provide the clinician insight into the factors influencing treatment outcome. With nucleoside or nucleotide analogues suppression of viral replication by 5-7 log10 is feasible, but not all patients respond to therapy. Known factors influencing treatment outcome are viral load, ALT levels and compliance. Many other factors which might influence treatment are scarcely investigated. Identifying the factors associated with response might result in stopping rules, so treatment could be adapted in an early stage to provide adequate treatment and avoid the development of resistance. The efficacy of compounds for the treatment of mutant virus and the cross-resistance is largely unknown. However, genotypic and phenotypic testing as well as small clinical trials provided some data on efficacy in this population. Discontinuation of nucleoside or nucleotide analogues frequently results in viral relapse; however, some patients have a sustained response. Data on the risk factors for relapse are necessary in order to determine when treatment can be discontinued safely. In conclusion： chronic hepatitis B has become a treatable disease; however, much research is needed to tailor therapy to an individual patient, to predict the susta

关键词： Hepatitis B virus Cirrhosis Treatment Interferon Nucleoside analogues Nucleotide analogues Lamivudine Adefovir Entecavir Telbivudine Tenofovir Resistance Genotype

Existence Results for a Class of Periodic Evolution Variational Inequalities

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Chinese Annals of Mathematics,Series B 2007年第6期28卷 629-650页

作者： Samir ADLY Daniel GOELEVEN Michel THra DMI-XLIM UMR-CNRS 6172Université de Limoges123 Avenue A.Thomas87060 Limoges CedexFrance. IREMIA Université de La Réunion97400 Saint-DenisFrance.

In this paper, using the Brouwer topological degree, the authors prove an existence result for finite variational inequalities. This approach is also used to obtain the existence of periodic solutions for a class of e... 详细信息

关键词： Variational inequalities Differential inclusions Topological degree Guiding functions Periodic solutions

Is there a potential of circulating miRNAs as biomarkers in rheumatic diseases?

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Genes & Diseases 2023年第4期10卷 1263-1278页

作者： Klára Prajzlerová Ladislav Senolt Mária Filková Institute of Rheumatology Prague 12800Czech Republic Department of Rheumatology First Faculty of MedicineCharles UniversityPrague 12800Czech Republic

t MicroRNAs(miRNAs)are small non-coding single-stranded RNAs of about 22 nucle-otides in length that act as post-transcriptional regulators of gene *** on the complementarity between miRNA and target mRNA,cleavage,destabilization,or transla-tional suppression of mRNA occurs within the RISC(RNA-induced silencing complex).As gene expression regulators,miRNAs are involved in a variety of biological *** of miRNAs and their target genes contribute to the pathophysiology of many diseases,including autoimmune and inflammatory *** are also present extracellularly in their sta-ble form in body *** incorporation into membrane vesicles or protein complexes with Ago2,HDL,or nucleophosmin 1 protects them against ***-free miRNAs can be deliv-ered to another cell in vitro and maintain their functional ***,miRNAs can be considered mediators of intercellular *** remarkable stability of cell-free miRNAs and their accessibility in body fluid makes them potential diagnostic or prognostic bio-markers and potential therapeutic *** we provide an overview of the potential role of circulating miRNAs as biomarkers of disease activity,therapeutic response,or diagnosis in rheumatic *** circulating miRNAs reflect their involvement in the pathogenesis,while for plenty,their pathogenetic mechanisms remain to be *** miRNAs described as biomarkers were also shown to be of therapeutic potential,and some miRNAs arealready tested in clinical trials.

关键词： Biomarker Diagnosis miRNA Rheumatic diseases Therapy

Metasurfaces for next-generation wireless communication systems

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National Science Review 2023年第8期10卷 17-19页

作者： Younes ra'di Nikita Nefedkin Petar Popovski Andrea Alù Department of Electrical Engineering and Computer Science Syracuse University Photonics Initiative Advanced Science Research Center City University of New York Department of Electronic Systems Aalborg University Physics Program Graduate Center City University of New York

The pace of development in the world of 5G communication systems has proven to be much more demanding than previous generations, with 5G-Advanced seemingly around the corner [1]. Extensive research is already underway to structure the next generation of wireless systems(i.e. 6G), which may potentially enable an unprecedented level of human–machine interaction [2].

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Hölder,Sobolev,weak-type and BMO estimates in mixed-norm with weights for parabolic equations

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Science China Mathematics 2021年第1期64卷 129-154页

作者： Pablo raúl Stinga José L.Torrea Department of Mathematics Iowa State UniversityAmesIA50011USA Departamento de Matemáticas Universidad Autónoma de MadridMadrid28049Spain

We prove weighted mixed-norm Lqt(W2,px)and Lqt(C2,αx)estimates for 10,x∈Rn.x∈Rn,The coefficients a(t)=(aij(t))are just bounded,measurable,symmetric and uniformly ***,we show strong,weak type and BMO-Sobolev estimat... 详细信息

We prove weighted mixed-norm Lqt(W2,px)and Lqt(C2,αx)estimates for 1rabolic equations of the form∂tu−aij(t)∂iju+u=f,t∈,x∈n and for the Cauchy problem{∂tv−aij(t)∂ijv+v=fv(0,x)forfort>0,x∈Rn.x∈Rn,The coefficients a(t)=(aij(t))are just bounded,measurable,symmetric and uniformly ***,we show strong,weak type and BMO-Sobolev estimates with parabolic Muckenhoupt *** is quite remarkable that most of our results are new even for the classical heat equation∂tu−Δu+u=f.

关键词： Calderón-Zygmund parabolic singular integrals weak type and BMO estimates representation formulas parabolic equations mixed-norm Sobolev and Schauder estimates