The Critical Behaviour of the Spin-3/2 Blume-Capel Model in Two Dimensions

The phase diagram of the spin-3/2 Blume-Capel model in two dimensions is explored by conventional finite-size scaling, conformal invariance and Monte Carlo simulations. The model in its $\tau$-continuum Hamiltonian version is also considered and compared with others spin-3/2 quantum chains. Our results indicate that differently from the standard spin-1 Blume-Capel model there is no multicritical point along the order-disorder transition line. This is in qualitative agreement with mean field prediction but in disagreement with previous approximate renormalization group calculations. We also presented new results for the spin-1 Blume-Capel model.Comment: latex 18 pages, 4 figure

Development and validation of a reversed phase HPLC method for determination of anacardic acids in cashew (Anacardium occidentale) nut shell liquid.

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Acute TNFα levels predict cognitive impairment 6-9 months after COVID-19 infection.

A neurocognitive phenotype of post-COVID-19 infection has recently been described that is characterized by a lack of awareness of memory impairment (i.e., anosognosia), altered functional connectivity in the brain's default mode and limbic networks, and an elevated monocyte count. However, the relationship between these cognitive and brain functional connectivity alterations in the chronic phase with the level of cytokines during the acute phase has yet to be identified. Determine whether acute cytokine type and levels is associated with anosognosia and functional patterns of brain connectivity 6-9 months after infection. We analyzed the predictive value of the concentration of acute cytokines (IL-1RA, IL-1β, IL-6, IL-8, IFNγ, G-CSF, GM-CSF) (cytokine panel by multiplex immunoassay) in the plasma of 39 patients (mean age 59 yrs, 38-78) in relation to their anosognosia scores for memory deficits via stepwise linear regression. Then, associations between the different cytokines and brain functional connectivity patterns were analyzed by MRI and multivariate partial least squares correlations for the whole group. Stepwise regression modeling allowed us to show that acute TNFα levels predicted (R <sup>2</sup> = 0.145; β = -0.38; p = .017) and were associated (r = -0.587; p < .001) with scores of anosognosia for memory deficits observed 6-9 months post-infection. Finally, high TNFα levels were associated with hippocampal, temporal pole, accumbens nucleus, amygdala, and cerebellum connectivity. Increased plasma TNFα levels in the acute phase of COVID-19 predict the presence of long-term anosognosia scores and changes in limbic system functional connectivity

Brain functional connectivity alterations associated with neuropsychological performance 6-9 months following SARS-CoV-2 infection.

Neuropsychological deficits and brain damage following SARS-CoV-2 infection are not well understood. Then, 116 patients, with either severe, moderate, or mild disease in the acute phase underwent neuropsychological and olfactory tests, as well as completed psychiatric and respiratory questionnaires at 223 ± 42 days postinfection. Additionally, a subgroup of 50 patients underwent functional magnetic resonance imaging. Patients in the severe group displayed poorer verbal episodic memory performances, and moderate patients had reduced mental flexibility. Neuroimaging revealed patterns of hypofunctional and hyperfunctional connectivities in severe patients, while only hyperconnectivity patterns were observed for moderate. The default mode, somatosensory, dorsal attention, subcortical, and cerebellar networks were implicated. Partial least squares correlations analysis confirmed specific association between memory, executive functions performances and brain functional connectivity. The severity of the infection in the acute phase is a predictor of neuropsychological performance 6-9 months following SARS-CoV-2 infection. SARS-CoV-2 infection causes long-term memory and executive dysfunctions, related to large-scale functional brain connectivity alterations

PRODUÇÃO EM LARGA ESCALA DE FIBRAS POR ELETROFIAÇÃO E OUTROS MÉTODOS ALTERNATIVOS.

O termo nanotecnologia está cada vez mais presente no dicionário da ciência e inovação. Nos últimos anos, diversas áreas do conhecimento têm explorado cada vez mais o uso de nanomateriais, i.e., que possuem dimensões de 1 até 100nm (maiores detalhes no Capítulo 1), os quais podem ser considerados a próxima geração de materiais com propriedades especificas melhoradas. As nanofibras estão entre esses materiais em escala nanométrica com várias propriedades interessantes. Dentre as propriedades especificas, a alta área superficial ativa, elevada flexibilidade e capacidade de incorporação de partículas atribuem às nanofibras um potencial elevado para diversas aplicações, incluindo: filtração, (bio)sensores, liberação controlada de drogas, curativos para feridas, engenharia de tecidos, entre outras. Tal versatilidade e vasta gama de plicações evidenciam a necessidade de escalabilidade da produção de micro/nanofibras. Dentre as diversas técnicas de produção de fibras, a eletrofiação (do inglês, electrospinning) é reconhecida como a mais difundida e eficiente, capaz de produzir fibras poliméricas, cerâmicas, compósitas, etc. (maiores detalhes no Capítulo 2). Além disso, essa técnica é capaz de gerar de forma contínua fibras ultrafinas para diferentes aplicações, conforme apresentado nos capítulos anteriores

Effect of different solvent ratios (water/ethylene glycol) on the growth process of CaMo'O IND.4' crystals and their optical properties

ABSTRACT: In this paper, calcium molybdate (CaMoO4) crystals (meso- and nanoscale) were synthesized by the coprecipitation\ud method using different solvent volume ratios (water/ethylene glycol). Subsequently, the obtained suspensions were\ud processed in microwave-assisted hydrothermal/solvothermal systems at 140 C for 1 h. These meso- and nanocrystals processed\ud were characterized by X-ray diffraction (XRD), Fourier transform Raman (FT-Raman), Fourier transform infrared (FT-IR),\ud ultraviolet-visible (UV-vis) absorption spectroscopies, field-emission gun scanning electron microscopy (FEG-SEM),\ud transmission electron microscopy (TEM), and photoluminescence (PL) measurements. XRD patterns and FT-Raman spectra\ud showed that these meso- and nanocrystals have a scheelite-type tetragonal structure without the presence of deleterious phases.\ud FT-IR spectra exhibited a large absorption band situated at around 827 cm-1, which is associated with the Mo-O antisymmetric\ud stretching vibrations into the [MoO4] clusters. FEG-SEM micrographs indicated that the ethylene glycol concentration\ud in the aqueous solution plays an important role in the morphological evolution of CaMoO4 crystals. High-resolution\ud TEM micrographs demonstrated that the mesocrystals consist of several aggregated nanoparticles with electron diffraction\ud patterns of monocrystal. In addition, the differences observed in the selected area electron diffraction patterns of CaMoO4\ud crystals proved the coexistence of both nano- and mesostructures. First-principles quantum mechanical calculations based on\ud the density functional theory at the B3LYP level were employed in order to understand the band structure and density of states\ud for the CaMoO4. UV-vis absorption measurements evidenced a variation in optical band gap values (from 3.42 to 3.72 eV) for\ud the distinct morphologies. The blue and green PL emissions observed in these crystals were ascribed to the intermediary energy\ud levels arising from the distortions on the [MoO4] clusters due to intrinsic defects in the lattice of anisotropic/isotropic crystals.FAPESP (09/50303-4)CNPqCAPE