86 research outputs found

    Estudo comparativo entre refractance window e liofilização na secagem de polpa de maracujá-azedo

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    Trabalho de Conclusão de Curso, apresentado para obtenção do grau de Engenheiro Químico, no Curso de Engenharia Química da Universidade do Extremo Sul Catarinense, UNESC.O maracujá-azedo (Passiflora edulis Sims) é um fruto tropical altamente perecível, devido à intensa atividade respiratória e à excessiva perda de água. Isto diminui a sua qualidade e deprecia seu valor comercial. Este problema pode ser solucionado através do uso de técnicas de conservação, sendo uma das alternativas a secagem. Por retirar a água do produto, a secagem reduz a deterioração microbiológica e as reações de degradação, aumentando assim a vida de prateleira do alimento. O processo de secagem também proporciona a redução no peso e volume do produto, facilitando o armazenamento e transporte. A liofilização é caracterizada principalmente por ser uma das melhores técnicas quando o foco é manter a qualidade do produto. A secagem por refractance window vem sendo bastante estudada como processo alternativo para a secagem de alimentos por manter suas características sensoriais (sabor e cor) e menor tempo de secagem. Neste contexto, o objetivo deste trabalho foi realizar um estudo comparativo entre as técnicas de secagem refractance window e liofilização para avaliar as perdas de vitamina C durante os processos. Foram realizadas as análises de cor, umidade, atividade de água e de vitamina C, na matéria prima in natura e após os processos de secagem. Para realizar a secagem por refractance window foi construído um secador de bancada com base nos equipamentos descritos na literatura. A secagem por refractance window foi realizada utilizando água como agente de aquecimento nas temperaturas de 60 e 80°C. Os produtos desidratados apresentaram estabilidade microbiológica (baixa umidade e atividade de água). Os resultados de vitamina C encontrados nos produtos para os dois processos estudados indicaram que a secagem por RW na temperatura de 60°C foi eficiente já que obteve valores próximos aos encontrados pelo processo de liofilização. Podendo ser utilizado em substituição a liofilização e gerando produtos com maior valor agregado já que apresenta baixo custo e menor tempo de processo

    Nonclinical psychotic‐like experiences and schizotypy dimensions: Associations with hippocampal subfield and amygdala volumes

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    Schizotypy and psychotic‐like experiences (PLE) form part of the wider psychosis continuum and may have brain structural correlates in nonclinical cohorts. This study aimed to compare the effects of differential schizotypy dimensions, PLE, and their interaction on hippocampal subfields and amygdala volumes in the absence of clinical psychopathology. In a cohort of 367 psychiatrically healthy individuals, we assessed schizotypal traits using the Oxford‐Liverpool Inventory of Life Experiences (O‐LIFE) and PLE using the short form of the Prodromal Questionnaire (PQ‐16). Based on high‐resolution structural MRI scans, we used automated segmentation to estimate volumes of limbic structures. Sex and total intracranial volume (Step 1), PLE and schizotypy dimensions (Step 2), and their interaction terms (Step 3) were entered as regressors for bilateral amygdala and hippocampal subfield volumes in hierarchical multiple linear regression models. Positive schizotypy, but not PLE, was negatively associated with left amygdala and subiculum volumes. O‐LIFE Impulsive Nonconformity, as well as the two‐way interaction between positive schizotypy and PLE, were associated with larger left subiculum volumes. None of the estimators for right hemispheric hippocampal subfield volumes survived correction for multiple comparisons. Our findings support differential associations of hippocampus subfield volumes with trait dimensions rather than PLE, and support overlap and interactions between psychometric positive schizotypy and PLE. In a healthy cohort without current psychosis risk syndromes, the positive association between PLE and hippocampal subfield volume occurred at a high expression of positive schizotypy. Further studies combining stable, transient, and genetic parameters are required

    Suppression of RhoG activity is mediated by a syndecan 4–synectin–RhoGDI1 complex and is reversed by PKCα in a Rac1 activation pathway

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    Fibroblast growth factor 2 (FGF2) is a major regulator of developmental, pathological, and therapeutic angiogenesis. Its activity is partially mediated by binding to syndecan 4 (S4), a proteoglycan receptor. Angiogenesis requires polarized activation of the small guanosine triphosphatase Rac1, which involves localized dissociation from RhoGDI1 and association with the plasma membrane. Previous work has shown that genetic deletion of S4 or its adapter, synectin, leads to depolarized Rac activation, decreased endothelial migration, and other physiological defects. In this study, we show that Rac1 activation downstream of S4 is mediated by the RhoG activation pathway. RhoG is maintained in an inactive state by RhoGDI1, which is found in a ternary complex with synectin and S4. Binding of S4 to synectin increases the latter's binding to RhoGDI1, which in turn enhances RhoGDI1's affinity for RhoG. S4 clustering activates PKCα, which phosphorylates RhoGDI1 at Ser96. This phosphorylation triggers release of RhoG, leading to polarized activation of Rac1. Thus, FGF2-induced Rac1 activation depends on the suppression of RhoG by a previously uncharacterized ternary S4–synectin–RhoGDI1 protein complex and activation via PKCα

    Modelling the overlap and divergence of autistic and schizotypal traits on hippocampal subfield volumes and regional cerebral blood flow.

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    Psychiatric disorders show high co-morbidity, including co-morbid expressions of subclinical psychopathology across multiple disease spectra. Given the limitations of classical case-control designs in elucidating this overlap, new approaches are needed to identify biological underpinnings of spectra and their interaction. We assessed autistic-like traits (using the Autism Quotient, AQ) and schizotypy - as models of subclinical expressions of disease phenotypes and examined their association with volumes and regional cerebral blood flow (rCBF) of anterior, mid- and posterior hippocampus segments from  structural MRI scans in 318 and arterial spin labelling (ASL) in 346 nonclinical subjects, which overlapped with the structural imaging sample (N = 298). We demonstrate significant interactive effects of positive schizotypy and AQ social skills as well as of positive schizotypy and AQ imagination on hippocampal subfield volume variation. Moreover, we show that AQ attention switching modulated hippocampal head rCBF, while positive schizotypy by AQ attention to detail interactions modulated hippocampal tail rCBF. In addition, we show significant correlation of hippocampal volume and rCBF in both region-of-interest and voxel-wise analyses, which were robust after removal of variance related to schizotypy and autistic traits. These findings provide empirical evidence for both the modulation of hippocampal subfield structure and function through subclinical traits, and in particular how only the interaction of phenotype facets leads to significant reductions or variations in these parameters. This makes a case for considering the synergistic impact of different (subclinical) disease spectra on transdiagnostic biological parameters in psychiatry

    RhoG regulates endothelial apical cup assembly downstream from ICAM1 engagement and is involved in leukocyte trans-endothelial migration

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    During trans-endothelial migration (TEM), leukocytes use adhesion receptors such as intercellular adhesion molecule-1 (ICAM1) to adhere to the endothelium. In response to this interaction, the endothelium throws up dynamic membrane protrusions, forming a cup that partially surrounds the adherent leukocyte. Little is known about the signaling pathways that regulate cup formation. In this study, we show that RhoG is activated downstream from ICAM1 engagement. This activation requires the intracellular domain of ICAM1. ICAM1 colocalizes with RhoG and binds to the RhoG-specific SH3-containing guanine-nucleotide exchange factor (SGEF). The SH3 domain of SGEF mediates this interaction. Depletion of endothelial RhoG by small interfering RNA does not affect leukocyte adhesion but decreases cup formation and inhibits leukocyte TEM. Silencing SGEF also results in a substantial reduction in RhoG activity, cup formation, and TEM. Together, these results identify a new signaling pathway involving RhoG and its exchange factor SGEF downstream from ICAM1 that is critical for leukocyte TEM

    Exploring the association between attention-deficit/hyperactivity disorder and entrepreneurship

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    Objective: To investigate the association between attention-deficit/hyperactivity disorder (ADHD) symptoms and entrepreneurial profiles and the effects of entrepreneurial characteristics in individuals who screen positive for ADHD and self-identify as entrepreneurs. Methods: We sent 4,341 questionnaires by e-mail to applicants for a career development course for entrepreneurs. We used the propensity score covariate adjustment to balance differences between included and excluded individuals. ADHD symptoms were evaluated with the Adult ADHD Self-Report Scale. The Individual Entrepreneurial Orientation scale was used to assess the entrepreneurial profile of the participants. Impairment from ADHD symptoms was assessed with the Barkley Functional Impairment Scale. Results: Those who screened positive for ADHD had higher risk-taking scores (p-value = 0.016) and lower proactivity (p-value = 0.001) than those who screened negative. Higher inattention scores were related to lower proactivity (p-value o 0.001), while higher hyperactive symptom scores were related to a more generalized entrepreneurial profile (p-value = 0.033). Among ADHD-positive participants, entrepreneurial profile scores were not significantly associated with company profits or impairment. Conclusion: Inattention symptoms were related to less proactivity, whereas hyperactive symptoms were positively associated with a general entrepreneurial orientation. ADHD-positive individuals had a higher risk-taking profile, and these characteristics did not negatively impact their lives

    Microglia Control Vascular Architecture via a TGFβ1 Dependent Paracrine Mechanism Linked to Tissue Mechanics

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    © 2020, The Author(s). Tissue microarchitecture and mechanics are important in development and pathologies of the Central Nervous System (CNS); however, their coordinating mechanisms are unclear. Here, we report that during colonization of the retina, microglia contacts the deep layer of high stiffness, which coincides with microglial bipolarization, reduction in TGFβ1 signaling and termination of vascular growth. Likewise, stiff substrates induce microglial bipolarization and diminish TGFβ1 expression in hydrogels. Both microglial bipolarization in vivo and the responses to stiff substrates in vitro require intracellular adaptor Kindlin3 but not microglial integrins. Lack of Kindlin3 causes high microglial contractility, dysregulation of ERK signaling, excessive TGFβ1 expression and abnormally-patterned vasculature with severe malformations in the area of photoreceptors. Both excessive TGFβ1 signaling and vascular defects caused by Kindlin3-deficient microglia are rescued by either microglial depletion or microglial knockout of TGFβ1 in vivo. This mechanism underlies an interplay between microglia, vascular patterning and tissue mechanics within the CNS

    Sleep disorders are associated with both morning temporal and jaw pain among adults and elderly: a population-based study in Brazil

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    Objective Purpose: To assess the influence of sleep disorders on temporal and jaw pain in the morning in adults and elderly people. Methods: Population-based study with representative individuals aged 18 years or over. Individuals were selected using a multistage sampling procedure. The outcomes of morning jaw pain and morning temporal pain were assessed. Sleep bruxism, obstructive sleep apnea, and sleep quality were evaluated as exposure variables. Adjusted analysis was conducted using Poisson regression. All analysis was sex stratified. Results: 820 individuals were studied. Female with sleep bruxism were 1.37 times more likely to have morning temporal pain (p=0.041). Male and female with bruxism had a prevalence 160% and 97%, respectively, higher of morning jaw pain (male: p=0.003; female: p<0.001). Women with obstructive sleep apnea were 1.52 times more likely to have morning temporal pain (p=0.023). Men with poor sleep quality had a prevalence 190% higher of morning temporal pain (p=0.005). Conclusion: Morning craniofacial pain is more frequent in individuals with sleep disorders, and there are differences between sexes. Since more than one sleep disorder can be present in the same individual, studies that adjust the analyses for possible confounders are important to avoiding possible overlap between them
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