A set of exactly solvable Ising models with half-odd-integer spin

We present a set of exactly solvable Ising models, with half-odd-integer spin-S on a square-type lattice including a quartic interaction term in the Hamiltonian. The particular properties of the mixed lattice, associated with mixed half-odd-integer spin-(S,1/2) and only nearest-neighbour interaction, allow us to map this system either onto a purely spin-1/2 lattice or onto a purely spin-S lattice. By imposing the condition that the mixed half-odd-integer spin-(S,1/2) lattice must have an exact solution, we found a set of exact solutions that satisfy the {\it free fermion} condition of the eight vertex model. The number of solutions for a general half-odd-integer spin-S is given by $S+1/2$. Therefore we conclude that this transformation is equivalent to a simple spin transformation which is independent of the coordination number

Equivalence between non-bilinear spin-SS Ising model and Wajnflasz model

We propose the mapping of polynomial of degree 2S constructed as a linear combination of powers of spin-$S$ (for simplicity, we called as spin-$S$ polynomial) onto spin-crossover state. The spin-$S$ polynomial in general can be projected onto non-symmetric degenerated spin up (high-spin) and spin down (low-spin) momenta. The total number of mapping for each general spin-$S$ is given by $2(2^{2S}-1)$. As an application of this mapping, we consider a general non-bilinear spin-$S$ Ising model which can be transformed onto spin-crossover described by Wajnflasz model. Using a further transformation we obtain the partition function of the effective spin-1/2 Ising model, making a suitable mapping the non-symmetric contribution leads us to a spin-1/2 Ising model with a fixed external magnetic field, which in general cannot be solved exactly. However, for a particular case of non-bilinear spin-$S$ Ising model could become equivalent to an exactly solvable Ising model. The transformed Ising model exhibits a residual entropy, then it should be understood also as a frustrated spin model, due to competing parameters coupling of the non-bilinear spin-$S$ Ising model

Efecto de los diferentes tiempos de grabado ácido sobre la resistencia de unión de un sistema adhesivo autoacondicionante en esmalte bovino.

Effect of the different acid etching times over the bond strength of a self etching adhesive system in bovine enamel

Causas de exodoncias en dientes permanentes de pacientes adultos atendidos en un establecimiento de salud público. Piura 2018 - 2020

El objetivo del presente estudio fue determinar las causas de exodoncias en dientes permanentes de pacientes adultos atendidos en un establecimiento de salud público de Piura durante el año 2018 al 2020. La investigación es de tipo básica, no experimental, transversal, observacional, descriptivo y retrospectivo; la data fue de 616 tratamientos de extracciones realizadas en el periodo 2018 al 2020. Según resultados obtenidos, la necrosis pulpar fue la causa más frecuente con 33.11%; las piezas dentales más frecuentes a extraerse son el primer premolar superior izquierdo con 7.3%; las causas predominantes según grupo etario son: en joven, la caries dental con 9.74%; en adulto, la necrosis pulpar con 24.35% y en adulto mayor, la periodontitis crónica con 6.49% mostrándose relación entre éstas variables; la causa de extracción según género, en varones fue periodontitis crónica con 6.33% y en mujeres fue necrosis pulpar con 29.22% encontrándose significancia estadística entre las variables. Se concluye que la necrosis pulpar fue la causa más frecuente de exodoncias

Generalized Transformation for Decorated Spin Models

The paper discusses the transformation of decorated Ising models into an effective \textit{undecorated} spin models, using the most general Hamiltonian for interacting Ising models including a long range and high order interactions. The inverse of a Vandermonde matrix with equidistant nodes $[-s,s]$ is used to obtain an analytical expression of the transformation. This kind of transformation is very useful to obtain the partition function of decorated systems. The method presented by Fisher is also extended, in order to obtain the correlation functions of the decorated Ising models transforming into an effective undecorated Ising models. We apply this transformation to a particular mixed spin-(1/2,1) and (1/2,2) square lattice with only nearest site interaction. This model could be transformed into an effective uniform spin-$S$ square lattice with nearest and next-nearest interaction, furthermore the effective Hamiltonian also include combinations of three-body and four-body interactions, particularly we considered spin 1 and 2.Comment: 16 pages, 4 figure

Aplicación de la topología molecular en la predicción de la inhibición de Trypanosoma cruzi Hexokinasa y un grupo de derivados bifosfonatos

A topological-mathematical model has been arranged to search for new derivatives of bisphosphonate compounds actingas inhibitors against Trypanosoma cruzi hexokinase. By using linear discriminant analysis, a four-variable function wasachieved allowing an accurate prediction of the IC50 for each compound of the training and test series. After carryingout a virtual screening based upon such a model, new structures potentially actives against T. cruzi are proposedSe ha desarrollado un modelo topológico-matemático para la búsqueda de nuevos derivados bisfosfonatos activosfrente a la hexokinasa de Trypanosoma cruzi. Utilizando el análisis lineal discriminante se ha seleccionado una funcióncon cuatro variables capaz de predecir adecuadamente la CI50 para cada compuesto de las series de entrenamientoy test. El modelo propuesto se ha aplicado a una librería molecular y se han propuesto nuevas estructuraspotencialmente activas frente a T. cruzi

Sustainable sugarcane vinasse biorefinement for trans-aconitic acid-based biopolymer synthesis and bioenergy generation

This study aimed at developing a multiproduct biorefinery scheme for vinase valorization. It involved the extraction of trans-aconitic acid, its transformation into biopolymers using microwave irradiation and the use of the raffinated-vinasse for biogas production. Each technology was assessed individually, followed by a process integration at bench scale, from which a mass balance was calculated, supporting the feasibility of the approach. As a renewable source derived from a residue, these bioproducts can replace crude-oil-based materials in various chemical industrial processes; however, a detailed techno-economic and life-cycle analysis are required to defined the sustainability of the process

Essential oils as antibacterial agents against food-borne pathogens: are they really as useful as they are claimed to be ?

Original articleMost studies evaluating the use of essential oils (EO) as antibacterial agents focus mainly on minimal inhibitory concentrations (MIC) rather than minimal bactericidal concentrations (MBC). In this work, we compared MICs and MBCs of EO from condiment plants commonly used in Mediterranean Europe, namely Origanum vulgare, Salvia lavandulaefolia, Salvia officinalis, Salvia sclarea and Rosmarinus officinalis, aiming to evaluate their application as disinfecting agents in minimally processed produce. Outbreaks-related pathogens such as Listeria monocytogenes, Pseudomonas aeruginosa and Yarrowia lipolytica were used. Results showed that all EO were able to reduce bacterial growth in all bacterial strains tested, particularly O. vulgare. However, fewer EO exhibited bactericidal activities, and were only effective against one or two bacterial strains, hence eliminating the possibility to use them as broad range disinfectants. Furthermore, the necessary concentrations were too high for food application. Hence, our work suggests the need to evaluate MBC rather than MIC and questions EO usefulness in controlling undesired microorganisms. Overall, and despite the large volume of data published on EO, results obtained were not very encouraging for a realistic application on produce and question the viability of EOs as disinfecting agents in foodinfo:eu-repo/semantics/publishedVersio

Inadequate glucose control in type 2 diabetes is associated with impaired lung function and systemic inflammation: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Inadequate glucose control may be simultaneously associated with inflammation and decreased lung function in type 2 diabetes. We evaluated if lung function is worse in patients with inadequate glucose control, and if inflammatory markers are simultaneously increased in these subjects.</p> <p>Methods</p> <p>Subjects were selected at the Colombian Diabetes Association Center in Bogotá. Pulmonary function tests were performed and mean residual values were obtained for forced expiratory volume (FEV₁₎, forced vital capacity (FVC) and FEV₁/FVC, with predicted values based on those derived by Hankinson et al. for Mexican-Americans. Multiple least-squares regression was used to adjust for differences in known determinants of lung function. We measured blood levels of glycosylated hemoglobin (HBA_1c), interleukin 6 (IL-6), tumor necrosis factor (TNF-α), fibrinogen, ferritin, and C-reactive protein (C-RP).</p> <p>Results</p> <p>495 diabetic patients were studied, out of which 352 had inadequate control (HBA_1c> 7%). After adjusting for known determinants of lung function, those with inadequate control had lower FEV₁(-75.4 mL, IC95%: -92, -59; P < 0.0001) and FVC (-121 mL, IC95%: -134, -108; P < 0,0001) mean residuals, and higher FEV₁/FVC (0.013%, IC95%: 0.009, 0.018, P < 0.0001) residuals than those with adequate control, as well as increased levels of all inflammatory markers (P < 0.05), with the exception of IL-6.</p> <p>Conclusions</p> <p>Subjects with type 2 diabetes and inadequate control had lower FVC and FEV₁than predicted and than those of subjects with adequate control. It is postulated that poorer pulmonary function may be associated with increased levels of inflammatory mediators.</p