RVB signatures in the spin dynamics of the square-lattice Heisenberg antiferromagnet

We investigate the spin dynamics of the square-lattice spin-1/2 Heisenberg antiferromagnet by means of an improved mean field Schwinger boson calculation. By identifying both, the long range N\'eel and the RVB-like components of the ground state, we propose an educated guess for the mean field triplet excitation consisting on a linear combination of local and bond spin flips to compute the dynamical structure factor. Our main result is that when this triplet excitation is optimized in such a way that the corresponding sum rule is fulfilled, we recover the low and high energy spectral weight features of the experimental spectrum. In particular, the anomalous spectral weight depletion at $(\pi,0)$ found in recent inelastic neutron scattering experiments can be attributed to the interference of the triplet bond excitations of the RVB component of the ground state. We conclude that the Schwinger boson theory seems to be a good candidate to adequately interpret the dynamic properties of the square-lattice Heisenberg antiferromagnet.Comment: 6 pages with 3 figure

Interplay between spatial anisotropy and further exchange interactions in the triangular Heisenberg model

We investigate the interplay between spatial anisotropy and further exchange interactions in the spin-$\frac{1}{2}$ Heisenberg antiferromagnetic model on a triangular lattice. We use the Schwinger boson theory by including Gaussian fluctuations above the mean-field approach. The phase diagram exhibits a strong reduction of the long range collinear and incommensurate spirals regions with respect to the mean-field ones. This reduction is accompanied by the emergence of its short range order counterparts, leaving an ample room for $0$-flux and nematic spin liquid regions. Remarkably, within the neighborhood of the spatially isotropic line, there is a range where the spirals are so fragile that only the commensurate $120^{\circ}$ N\'eel ones survive. The good agreement with recent variational Monte Carlo predictions gives support to the rich phase diagram induced by spatial anisotropy.Comment: 8 pages, 8 figure

Longer breastfeeding duration is associated with lower consumption of ultraprocessed foods in a sample of spanish preschoolers: The SENDO project

Background: Breastfeeding has been linked to a higher consumption of fruit and vegetables at ages 4 to 5 years. More recently, it has been suggested that it may also be associated with lower ultraprocessed food (UPF) consumption in childhood. Objective: The aim of this study was to assess whether breastfeeding duration was associated with consumption of UPF in a sample of Mediterranean preschoolers. Design: This study involved a cross-sectional analysis of baseline information of children in the Child Follow-Up for Optimal Development cohort. Children were enrolled at ages 4 to 5 years and information was gathered through an online questionnaire completed by parents. Dietary information was collected with a previously validated semi-quantitative food frequency questionnaire and foods were classified based on the degree of processing according to the NOVA classification. Participants/setting: This study used baseline information for 806 participants enrolled in the Child Follow-Up for Optimal Development cohort between January 2015 and June 2021 in Spain. Main outcomes measures: Main study outcome measures were difference in grams per day and in the percentage of total energy intake from UPF consumption related to breastfeeding duration, and odds ratio that UPF represents a high percentage of total energy intake. Statistical analyses: Crude and multivariable adjusted estimates were calculated with generalized estimating equations to account for intracluster correlation between siblings. Results: The prevalence of breastfeeding in the sample was 84%. After adjusting for potential confounders, children who were breastfed for some time reported significantly lower consumption of UPF than children who were not breastfed at all. The mean differences were -19.2 g (95% CI -44.2 to 10.8) for children who were breastfed for <6 months, -42.5 g (95% CI -77.2 to -7.80) for those who were breastfed for 6 to 12 months, and -43.6 g (95% CI -79.8 to -7.48) for those who were breastfed for 12 months or more (P value for trend = 0.01). After adjusting for potential confounders, compared with children who were not breastfed, those who were breastfed for ≥12 months had consistently lower odds of UPF representing more than 25%, 30%, 35%, and 40% of total energy intake. Conclusions: Breastfeeding is associated with lower consumption of UPF in Spanish preschoolers

Quantic Analysis of Formation of a Biomaterial of Latex, Retinol, and Chitosan for Biomedical Applications

The present work shows the quantum theoretical analysis and practical tests for the formation of a homogeneous mixture with Latex (Lx), Chitosan (Qn) and Retinol (Rl), which work as possible biomaterial for regeneration of epithelial tissue. Lx, Qn, and Rl compounds molecules were designed through Hyperchem to get the coefficient of electrostatic potential calculations. The amounts used to create the biomaterial are minimum depending on the quantities of molecules used in chemical design. A positive calculation was obtained for the reaction of these three compounds and the formation of the biomaterial in physical checking theory etc

Galanin and neuropeptide Y interactions linked to neuronal precursor cells of the dentate gyrus in the hippocampus. Role in depression and cognitive impairment.

Galanin (GAL) interacts with Neuropeptide Y Y1 receptors (NPYY1R) in several regions of the central nervous system associated with mood and motivation, through GAL receptor 2 and NPYY1 receptor 1 (GALR2/NPYY1R) heterodimers. The current work is to evaluate GALR2 and NPYY1R interactions concerning newborn cell proliferation in the ventral and dorsal hippocampal Dentate Gyrus. Rats (n = 6-8 per group) were randomly assigned to the groups. Each group received i.c.v. injections of artificial Cerebro Spinal Fluid (aCSF), GAL or NPYY1R agonist [Leu31,Pro34]NPY alone or in combination and 24 h later rats were subjected to a 5-min swimming session (test). A different set of rats received ip injections of BrdU 50mg/Kg at 2 and 4 hours after icv injections. 24 hours later brains collected for immunostaining to evaluate cell proliferation. We observed that the icv injection of GAL and NPYY1R agonist significantly enhanced the decrease in the immobility and the increase in the swimming behavior compared with the NPYY1R agonist alone. Furthermore, GALR2 is involved in this GALR/NPYY1R interaction, since the presence of the GALR2 antagonist M871 counteracted all the parameters. In parallel, coadministration of GAL and NPYY1R agonist increased BrdU-labeled cells located in the SGZ compared with aCSF, GAL and the NPYY1R group. Similar results were observed in dorsal hippocampus. Our results may provide the basis for the development of heterobivalent agonist pharmacophores, targeting GALR2/NPYY1R heteromers, especially in the neuronal precursor cells of the dentate gyrus in the hippocampus for the novel treatment of depression or cognitive impairments. Study supported by Proyecto UMA18- FEDERJA-100, Proyecto Puente-Universidad de Málaga, proyecto jóvenes investigadores UMA to MNP.Study supported by Proyecto UMA18- FEDERJA-100, Proyecto Puente-Universidad de Málaga, proyecto jóvenes investigadores UMA to MNP.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Coexistence and Criticality in Size-Asymmetric Hard-Core Electrolytes

Liquid-vapor coexistence curves and critical parameters for hard-core 1:1 electrolyte models with diameter ratios lambda = sigma_{-}/\sigma_{+}=1 to 5.7 have been studied by fine-discretization Monte Carlo methods. Normalizing via the length scale sigma_{+-}=(sigma_{+} + sigma_{-})/2 relevant for the low densities in question, both Tc* (=kB Tc sigma_{+-}/q^2 and rhoc* (= rhoc sigma _{+-}^{3}) decrease rapidly (from ~ 0.05 to 0.03 and 0.08 to 0.04, respectively) as lambda increases. These trends, which unequivocally contradict current theories, are closely mirrored by results for tightly tethered dipolar dimers (with Tc* lower by ~ 0-11% and rhoc* greater by 37-12%).Comment: 4 pages, 5 figure

Study of the spatial variability of copper and cadmium concentration along the Meuse River margin.

O conhecimento dos n?veis de concentra??o de metais pesados no ambiente e sua dissemina??o no solo e nas ?guas s?o de primordial import?ncia em estudos ambientais, por constituir um dos indicadores de ?medi??o? do equil?brio da biodiversidade e da estabilidade dos ecossistemas. O presente trabalho teve como objetivo, estudar a distribui??o espacial de dois metais pesados (Cobre e C?dmio) ao longo das margens do rio Meuse, por forma a medir os n?veis de contamina??o por esses metais. Foram usados dados da concentra??o de Cd e Cu amostrados em 155 pontos georeferenciados. Estes dados foram obtidos no programa R no pacote ?gstat? cuja base de dados denomina-se ?Meuse?. A metodologia de an?lise dos dados consistiu em ajustar semivariogramas para an?lise da depend?ncia espacial, e foram ajustados os modelos esf?ricos e gaussiano para a concentra??o de Cobre e C?dmio, respectivamente. O grau de depend?ncia espacial foi classificado como forte para a concentra??o de Cobre e moderada para a concentra??o de C?dmio. A estima??o da concentra??o destes metais pesados em pontos n?o amostrados, foi feita usando o m?todo de krigagem produzindo mapas de distribui??o espacial da concentra??o de Cobre e C?dmio que apresentaram um padr?o similar entre si. Verificou-se que dentre os dois metais pesados, o Cobre apresenta concentra??es muito altas que chegam a atingir os 130 mg/Kg de solo.The knowledge of the concentration levels of heavy metals in the environment and their dissemination in soil and water are of paramount importance in environmental studies, as one of the indicators of "measuring" the balance of biodiversity and the stability of ecosystems. The objective of this study was to study the spatial distribution of two heavy metals (Copper and Cadmium) along the banks of the Meuse River, in order to measure the levels of contamination by these metals. Cd and Cu concentration data were sampled at 155 georeferenced points. These data were obtained in the program R in the package "gstat" whose database is called "Meuse". The data analysis methodology consisted in adjusting semivariograms for spatial dependence analysis, and the spherical and Gaussian models were adjusted for the copper and cadmium concentration, respectively. The degree of spatial dependence was classified as strong for the copper concentration and moderate for the cadmium concentration. The estimation of the concentration of these heavy metals in non-sampled points was done using the kriging method, producing spatial distribution maps of the copper and cadmium concentrations that presented a similar pattern. It was verified that of the two heavy metals, Copper has very high concentrations that reach 130 mg / kg of soil

Engineered dual affinity protein fragments to bind collagen and capture growth factors

Collagen type I lacks affinity for growth factors (GFs) and yet it is clinically used to deliver bone morphogenic protein 2 (BMP-2), a potent osteogenic growth factor. To mitigate this lack of affinity, supra-physiological concentrations of BMP-2 are loaded in collagen sponges leading to uncontrolled BMP-2 leakage out of the material. This has led to important adverse side effects such as carcinogenesis. Here, we design recombinant dual affinity protein fragments, produced in E. Coli, which contain two regions, one that spontaneously binds to collagen and a second one that binds BMP-2. By adding the fragment to collagen sponges, BMP-2 is sequestered enabling solid phase presentation of BMP-2. We demonstrate osteogenesis in vivo with ultra-low doses of BMP-2. Our protein technology enhances the biological activity of collagen without using complex chemistries or changing the manufacturing of the base material and so opens a pathway to clinical translation