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"Available online 6 May 2022", In this work we propose a theoretical study of odd-even effects in charge transport through a linear three terminal chain device. We use the Landauer approach, with the electronic structure treated at tight binding (TB) level and model the self-energy as an energy independent parameter. Moreover, we use decimation techniques to renormalize the system, reducing it into a 3 × 3 matrix, so as to make an analytical treatment. By varying the size of the chain, we alter not only the parity of the full system but also the parity of each possible pathway and show how odd-even effect appears in the transmission function, local density of states and the behavior of the electrical current as function of the parity. Our theoretical approach reveals, in a clear way, how the parity of each branch competes with the parity of the full system to the conductance values near the Fermi level., This research was carried out with financial support from Federal University of Pernambuco (Brazil). L. Marques acknowledge the financial support of the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/04650/2020 and projects SATRAP (POCI-01-0145-FEDER-028108), SATRAP+( EXPL/FIS-MAC/0947/2021). The authors also acknowledge the Texas Advanced Computing Center (TACC) at The University of Texas at Austin for providing access to STAMPEDE2 - HPC resources that have contributed to the research results reported within this paper.

Orientador: Prof. Dr. Fabio Furlan Ferreira Coorientador: Prof. Dr. Ronei Miotto Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Física, Santo André, 2022. O foco deste trabalho foi estudar como alguns fatores físicos influenciam na eficiência da magneto-hipertermia, para isso desenvolveu-se uma série de rotinas que executam um algoritmo baseado em Monte-Carlo cinético e que utiliza o modelo de Stoner-Wohlfarth como base. Esse algoritmo foi validado através de comparações entre resultados teóricos e experimentais e com comparações com outros algoritmos já validados na literatura. As rotinas criadas se mostraram uma poderosa ferramenta computacional útil para realização de estudos sistemáticos de fluídos magnéticos sobre diferentes condições. Com ele foi possível estudar as influências das características do campo magnético externo, da concentração dos fluídos magnéticos, das diferentes formas de aglomerados entre outros fatores. Do ponto de vista de custo computacional o algoritmo baseado no modelo de Stoner-Wohlfarth aliado ao método de Monte-Carlo cinético se mostrou mais barato do que algoritmos que integram a equação de Landau-Lifshitz-Gilbert diretamente, porém ambos observam mesmas tendências e o software desenvolvido neste trabalho permite simular sistemas mais próximos dos estudados experimentalmente, o que a torna uma ferramenta indicada para os estudos desejados neste trabalho. Além do legado de um algoritmo robusto e de baixo custo computacional, a partir do uso destas rotinas foi possível entender alguns aspectos fundamentais do processo de liberação de calor, como por exemplo o fato da formação de aglomerados poder contribuir para o aumento da energia liberada devido a criação de vínculos entre os eixos fáceis de magnetização das nanopartículas. As simulações mostraram que as cadeias lineares paralelas ao campo externo são o formato de aglomerado que mais contribui para o processo de liberação de calor. Por fim foi possível obter-se a demonstração de que deve haver um tamanho ótimo de cadeias lineares, fato já observado experimentalmente por colaboradores e que foi comprovado pelas simulações. The focus in this work was to study how some physical factors influence the efficiency of magneto-hyperthermia, thereunto a series of routines were developed, this routines run an algorithm based on kinetic Monte-Carlo and that uses the Stoner-Wohlfarth model as a basis. This algorithm was validated through comparisons between theoretical and experimental results besides comparisons with other algorithms already validated in the literature. The created routines proved to be a powerful computational tool useful for carrying out systematic studies of magnetic fluids under different conditions. Through the use of this algorithm was possible to study the influences of the characteristics of the external magnetic field, the concentration of magnetic fluids, the different forms of aggregates, among other factors. From the point of view of computational cost, the algorithm based on the Stoner-Wohlfarth model combined with the kinetic Monte-Carlo method proved to be more efficiency than algorithms that integrate the Landau-Lifshitz-Gilbert equation directly, but both observe the same trends and the software developed in this work allows simulating systems closer to those studied experimentally, which makes it a better tool for the desired studies in this work. Besides to the legacy of a robust and low computational cost algorithm, using these routines it was possible to understand some fundamental aspects of the heat release process, such as the fact that the formation of aggregates can contribute to the increase in the energy released due to creation of constraints between the easy magnetization axes of nanoparticles. The simulations showed that the linear chains parallel to the external field are the aggregates shape that most contributes to the heat release process. Finally, it was possible to demonstrate that there must be an optimal size of linear chains, a fact already observed experimentally by collaborators and which was proven by simulations as well.

The effect of magnetic interactions is a key issue for the performance of nanoparticles in magnetic fluid hyperthermia. There are reports informing on beneficial or detrimental effects in terms of the specific power absorption depending on the intrinsic magnetic properties and the spatial arrangement of the nanoparticles. To understand this effect, our model treats a simple system: an ensemble of identical nanoparticles arranged in an ideal chain with the easy axis of the effective uniaxial anisotropy of each particle aligned parallel to the chain. We study the magnetic relaxation of linear chains with low anisotropy in magnetic-fluid-hyperthermia experiments, a system that yields a larger hysteresis area than the noninteracting case (i.e., improved specific power absorption) for all orientations of the chain (even in the perpendicular configuration and the randomly oriented case). The most-favorable case is the chain parallel to the external field; however, we show that the incorporation of a dipolar-field component perpendicular to the external field is necessary for the correct modeling of chains nearly in the perpendicular configuration, which is not always done. The mechanism involved in the hysteresis-area increase can be interpreted as a shift between the local field and the applied field. Fil: Valdés, Daniela Paola. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche | Comision Nacional de Energia Atomica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche.; Argentina Fil: Lima, Enio Junior. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche; Argentina Fil: Zysler, Roberto Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche; Argentina Fil: de Biasi, Emilio. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche | Comision Nacional de Energia Atomica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche.; Argentina

The HOIP ubiquitin E3 ligase generates linear ubiquitin chains by forming a complex with HOIL‐1L and SHARPIN in mammals. Here, we provide the first evidence of linear ubiquitination induced by a HOIP orthologue in Drosophila. We identify Drosophila CG11321, which we named Linear Ubiquitin E3 ligase (LUBEL), and find that it catalyzes linear ubiquitination in vitro. We detect endogenous linear ubiquitin chain‐derived peptides by mass spectrometry in Drosophila Schneider 2 cells and adult flies. Furthermore, using CRISPR/Cas9 technology, we establish linear ubiquitination‐defective flies by mutating residues essential for the catalytic activity of LUBEL. Linear ubiquitination signals accumulate upon heat shock in flies. Interestingly, flies with LUBEL mutations display reduced survival and climbing defects upon heat shock, which is also observed upon specific LUBEL depletion in muscle. Thus, LUBEL is involved in the heat response by controlling linear ubiquitination in flies.

The paper deals with theoretical study of hysteretic magnetostriction of soft ferrogels – composite materials, consisting of the micron-sized magnetizable particles embedded into gel matrices. It is supposed that initially, before application of an external magnetic field, the particles are homogeneously and isotropically distributed in an elastic matrix. The theoretical explanation of the hysteresis phenomena is based on the conception that, under the field action, the particles rearrange into the linear chain-like aggregates. The typical length of the chains is determined by the competition between the force of magnetic attraction of the particles and the force of elastic deformation of the matrix., This work has been done under the financial support of the Russian Fund for Basic Research, 16-58-12003, 16-53- 12009, 16-32-00019 mol a, the Program of Russian Federation Ministry of Science and Education, projects 3.1438.2017/4.6, 11.10010.2017/5.2; 3.5214.2017/6.7; D.B. would like to acknowledge the financial support of the Deutsche Forschungsgemeinschaft (DFG) under Grant Bo 3343/1-1 within PAK 907. M.L-L was supported by the project FIS2013-41821-R (Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica, Ministerio de Economía y Competitividad, Spain, co-funded by ERDF, European Union) and by the project FIS2017-85954-R (Agencia Estatal de Investigación, AEI, Spain, cofunded by Fondo Europeo de Desarrollo Regional, ERDF, European Union).

Hepatic de-novo lipogenesis is a metabolic process implemented in the pathogenesis of type 2 diabetes. Clinically, the rate of this process can be ascertained by use of labeled acetate and stimulation by fructose administration. A systems pharmacology model of this process is desirable because it facilitates the description, analysis, and prediction of this experiment. Due to the multiple enzymes involved in de-novo lipogenesis, and the limited data, it is desirable to use single functional expressions to encapsulate the flux between multiple enzymes. To accomplish this we developed a novel simplification technique which uses the available information about the properties of the individual enzymes to bound the parameters of a single governing ‘transfer function’. This method should be applicable to any model with linear chains of enzymes that are well stimulated. We validated this approach with computational simulations and analytical justification in a limiting case. Using this technique we generated a simple model of hepatic de-novo lipogenesis in these experimental conditions that matched prior data. This model can be used to assess pharmacological intervention at specific points on this pathway. We have demonstrated this with prospective simulation of acetyl-CoA carboxylase inhibition. This simplification technique suggests how the constituent properties of an enzymatic chain of reactions gives rise to the sensitivity (to substrate) of the pathway as a whole.

International audience; The 1D discrete fractional Laplacian operator on a cyclically closed (periodic) linear chain with finite number $N$ of identical particles is introduced. We suggest a ''fractional elastic harmonic potential", and obtain the $N$-periodic fractional Laplacian operator in the form of a power law matrix function for the finite chain ($N$ arbitrary not necessarily large) in explicit form. In the limiting case $N\rightarrow \infty$ this fractional Laplacian matrix recovers the fractional Laplacian matrix of the infinite chain.The lattice model contains two free material constants, the particle mass $\mu$ and a frequency $\Omega_{\alpha}$.The ''periodic string continuum limit" of the fractional lattice model is analyzed where lattice constant $h\rightarrow 0$ and length $L=Nh$ of the chain (''string") is kept finite: Assuming finiteness of the total mass and total elastic energy of the chain in the continuum limit leads to asymptotic scaling behavior for $h\rightarrow 0$ of the two material constants, namely $\mu \sim h$ and $\Omega_{\alpha}^2 \sim h^{-\alpha}$. In this way we obtain the $L$-periodic fractional Laplacian (Riesz fractional derivative) kernel in explicit form. This $L$-periodic fractional Laplacian kernel recovers for $L\rightarrow\infty$ the well known 1D infinite space fractional Laplacian (Riesz fractional derivative) kernel. When the scaling exponent of the Laplacian takes integers, the fractional Laplacian kernel recovers, respectively, $L$-periodic and infinite space (localized) distributional representations of integer-order Laplacians.The results of this paper appear to be useful for the analysis of fractional finite domain problems for instance in anomalous diffusion (Levy flights), fractional Quantum Mechanics, and the development of fractional discrete calculus on finite lattices.

As an important application and extension of the foregoing ideas, and to obtain a first glimpse of wave phenomena, we consider the following system. Suppose we have N identical particles of mass m in a line, with each particle bound to its neighbors by a Hooke’s law force, with “spring constant” k. Let us assume the particles can only be displaced in one-dimension; label the displacement from equilibrium for the jth particle by qj , j = 1, ...,N. Let us also assume that particle 1 is attached to particle 2 on the right and a rigid wall on the left, and that particle N is attached to particle N 1 on the left and another rigid wall on the right., http://digitalcommons.usu.edu/foundation_wave/1004/thumbnail.jpg

7-(4-Fluorophenyl) and 7-phenyl-substituted 1,3-diphenyl-1,4-dihydro-1,2,4- benzotriazin-4-yl radicals were characterized by X-ray diffraction analysis and variable-temperature magnetic susceptibility studies. The radicals pack in 1D π stacks of equally spaced slipped radicals with interplanar distances of 3.59 and 3.67 Å and longitudinal angles of 40.97 and 43.47, respectively. Magnetic-susceptibility studies showed that both radicals exhibit antiferromagnetic interactions. Fitting the magnetic data revealed that the behavior is consistent with 1D regular linear antiferromagnetic chain with J=-12.9 cm-1, zJ'=-0.4 cm-1, g=2.0069 and J=-11.8 cm -1, zJ'=-6.5 cm-1, g=2.0071, respectively. Magnetic-exchange interactions in benzotriazinyl radicals are sensitive to the degree of slippage, and inter-radical separation and subtle changes in structure alter the fine balance between ferro- and antiferromagnetic interactions. Radically antiferromagnetic: The slippage of benzotrazinyl radicals inside stacked columns inhibited dimerization and promoted orthogonality however, the longer interplanar distances weakened the interaction. Magnetic studies revealed 1D antiferromagnetic interactions inside the columns (see figure). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. 18 48 15433 15438 Cited By :22

X-ray studies show that 1,3-diphenyl-7-(thien-2-yl)-1,4-dihydro-1,2,4- benzotriazin-4-yl (6) adopts a distorted, slipped π-stacked structure of centrosymmetric dimers with alternate short and long interplanar distances (3.48 and 3.52Å). Cyclic voltammograms of 7-(thien-2-yl)benzotriazin-4-yl 6 show two fully reversible waves that correspond to the -1/0 and 0/+1 processes. EPR and DFT studies on radical 6 indicate that the spin density is mainly delocalized over the triazinyl fragment. Magnetic susceptibility measurements show that radical 6 obeys Curie-Weiss behavior in the 5-300K region with C=0.378emuKmol -1 and Î̧=+4.72K, which is consistent with ferromagnetic interactions between S=1/2 radicals. Fitting the magnetic susceptibility revealed the behavior is consistent with an alternating ferromagnetic chain (g=2.0071, J 1=+7.12cm -1, J 2=+1.28cm -1). © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. 18 23 7109 7116 Cited By :28

We deduce the dynamic frequency-domain-lattice Green’s function of a linear chain with properties (masses and next-neighbor spring constants) of exponential spatial dependence. We analyze the system as discrete chain as well as the continuous limiting case which represents an elastic 1D exponentially graded material. The discrete model yields closed form expressions for the N × N Green’s function for an arbitrary number N = 2 , … , ∞ of particles of the chain. Utilizing this Green’s function yields an explicit expression for the vibrational mode density. Despite of its simplicity the model reflects some characteristics of the dynamics of a 1D exponentially graded elastic material. As a special case the well-known expressions for the Green’s function and oscillator density of the homogeneous linear chain are contained in the model. The width of the frequency band is determined by the grading parameter which characterizes the exponential spatial dependence of the properties. In the limiting case of large grading parameter, the frequency band is localized around a single finite frequency where the band width tends to zero inversely with the grading parameter. In the continuum limit the discrete Green’s function recovers the Green’s function of the continuous equation of motion which takes in the time domain the form of a Klein–Gordon equation.

A systematic investigation of the CuCl2/Mebta (Mebta = 1-methylbenzotriazole) reaction system is described, involving the determination of the influence of the Cu-II:Mebta ratio, the nature of solvent and the presence of counterions on the identity of the reaction products. As a consequence, complexes [Cu2Cl4(Mebta)(4)] (1), [CuCl2(Mebta)(2)] (2), {[Cu2Cl4(Mebta)(2)]}(n) (3), [Cu4OCl6(Mebta)(4)] . 0.25H(2)O (4 . 0.25H(2)O) and [Cu2Cl2(Mebta)(6)](ClO4)(2) (5) have been isolated and structurally characterized by single-crystal X-ray studies. Mebta behaves as a monodentate ligand binding through N(3). I is a dinuclear complex, the structure of 2 consists of discrete monomeric units, and that of 3 is composed of linear, well-separated polymeric chains of Cu-II atoms. The molecules of 4 . 0.25H(2)O have a central mu(4)-oxide ion surrounded tetrahedrally by four Cu-II atoms. In the cations of 5 the two Cu-II centres are asymmetrically bridged by two chloro ligands, with three Mebta molecules completing five coordination at each metal. Complexes were characterized by spectroscopic (IR, far-IR, solution UV/Vis) and thermal decomposition (TG, DTG, and DTA) techniques. Variable-temperature magnetic susceptibility data for 1, 3 and 5 showed intramolecular (1, 5) and intrachain (3) ferromagnetic exchange interactions. Estimates of the J parameters, experimentally derived, were in close agreement with a new magneto-structural criterion developed by us, holding for bis(mu-chloro) copper(II) dimers. A comparison between the CuCl2/Mebta and CuBr2/Mebta systems is also presented. (C) 2004 Elsevier B.V. All rights reserved. Inorganica Chimica Acta

En utilisant un modèle de liaisons fortes nous étudions la relaxation des distances dans un film mince de structure cubique en fonction de la taille. Nous discutons les résultats et les comparons à ceux obtenus pour une chaîne linéaire.

We show that spin S Heisenberg spin chains with an additional three-body interaction of the form (S_{i-1}S_{i})(S_{i}S_{i+1})+h.c. possess fully dimerized ground states if the ratio of the three-body interaction to the bilinear one is equal to 1/(4S(S+1)-2). This result generalizes the Majumdar-Ghosh point of the J_1-J_2 chain, to which the present model reduces for S=1/2. For S=1, we use the density matrix renormalization group method (DMRG) to show that the transition between the Haldane and the dimerized phases is continuous with central charge c=3/2. Finally, we show that such a three-body interaction appears naturally in a strong-coupling expansion of the Hubbard model, and we discuss the consequences for the dimerization of actual antiferromagnetic chains., Comment: 8 pages, 8 figures