Desenvolvimento de interacções pessoais na construção de blogues no âmbito da disciplina de biologia/geologia : um estudo preliminar

Este documento apresenta resultados preliminares de um estudo de caso desenvolvido no âmbito do Doutoramento em Didáctica das Ciências, onde se utilizaram as tecnologias informáticas em contexto educativo, numa turma do Ensino Secundário. O projecto desenvolvido propôs-se analisar a utilização de blogues como complemento nas aprendizagens em Biologia/Geologia, com enfoque nas CTSA. Pretendeu ainda analisar como se construíram as relações interpessoais entre os membros do projecto, realizado com recurso a trabalho de grupo. Estratégias que envolvam as chamadas “novas tecnologias” são importantes na Educação dos jovens para a sociedade actual também conhecida por “sociedade do conhecimento”

Simplex optimization and mathematical modeling of wheat straw dilute acid hydrolysisand

Wheat straw is an interesting biorefinery raw material, due to its abundance, chemical composition, and cost. Among the different pretreatments suitable for its processing, dilute acid hydrolysis still presents some benefits due to its simplicity. Nevertheless, it requires a careful optimization to avoid excessive by-products formation and catalyst spending. An attractive and simple optimization approach is the Sequential Simplex Method, an iterative procedure that enables to rapidly screen a large area ofoperational conditions and effectively encircle the optimal. In this work, dilute acid hydrolysis of wheat straw was optimized to selectively hydrolyze the hemicellulose fraction and obtain a pentose-rich fermentable hydrolyzate. The influence oftime (up to 180 min), and sulfuric acid concentration (up to 4%, w/w) were studied. The hydrolyzates obtained in the optimized conditions mainly contain free sugars (total content higher than 46 giL). The main potential microbial inhibitors found were acetic acid, furfural, and HMF, in concentrations lower than 4.8,1.7 and 0.3 giL, respectively. Empirical models describing the influence ofthe studied variables on sugars and by-products formation were validated for the entire domain. Sulfuric acid concentration was found to be the most influential variable, although both variables are statistically significant for xylose recovery. Interaction effects play a significant (negative) role. Data was also modeled based on the combined severity parameter (CS) and the results of these two approaches are compared and discussed. These hydrolyzates were easily utilized by Debaryomyces hansenii, a natural pentose assimilating yeast

Desenvolvimento de interacções pessoais na construção de blogues no âmbito da disciplina de biologia/geologia : um estudo preliminar

Este documento apresenta resultados preliminares de um estudo de caso desenvolvido no âmbito do Doutoramento em Didáctica das Ciências, onde se utilizaram as tecnologias informáticas em contexto educativo, numa turma do Ensino Secundário. O projecto desenvolvido propôs-se analisar a utilização de blogues como complemento nas aprendizagens em Biologia/Geologia, com enfoque nas CTSA. Pretendeu ainda analisar como se construíram as relações interpessoais entre os membros do projecto, realizado com recurso a trabalho de grupo. Estratégias que envolvam as chamadas "novas tecnologias" são importantes na Educação dos jovens para a sociedade actual também conhecida por "sociedade do conhecimento"

Leukocyte Associated Immunoglobulin Like Receptor 1 Regulation and Function on Monocytes and Dendritic Cells During Inflammation

Inhibitory receptors are crucial immune regulators and are essential to prevent exacerbated responses, thus contributing to immune homeostasis. Leukocyte associated immunoglobulin like receptor 1 (LAIR-1) is an immune inhibitory receptor which has collagen and collagen domain containing proteins as ligands. LAIR-1 is broadly expressed on immune cells and has a large availability of ligands in both circulation and tissues, implicating a need for tight regulation of this interaction. In the current study, we sought to examine the regulation and function of LAIR-1 on monocyte, dendritic cell (DC) and macrophage subtypes, using different in vitro models. We found that LAIR-1 is highly expressed on intermediate monocytes as well as on plasmacytoid DCs. LAIR-1 is also expressed on skin immune cells, mainly on tissue CD14(+) cells, macrophages and CD1c(+) DCs. In vitro, monocyte and type-2 conventional DC stimulation leads to LAIR-1 upregulation, which may reflect the importance of LAIR-1 as negative regulator under inflammatory conditions. Indeed, we demonstrate that LAIR-1 ligation on monocytes inhibits toll like receptor (TLR)4 and Interferon (IFN)-alpha- induced signals. Furthermore, LAIR-1 is downregulated on GM-CSF and IFN-gamma monocyte-derived macrophages and monocyte-derived DCs. In addition, LAIR-1 triggering during monocyte derived-DC differentiation results in significant phenotypic changes, as well as a different response to TLR4 and IFN-alpha stimulation. This indicates a role for LAIR-1 in skewing DC function, which impacts the cytokine expression profile of these cells. In conclusion, we demonstrate that LAIR-1 is consistently upregulated on monocytes and DC during the inflammatory phase of the immune response and tends to restore its expression during the resolution phase. Under inflammatory conditions, LAIR-1 has an inhibitory function, pointing toward to a potential intervention opportunity targeting LAIR-1 in inflammatory conditions

Oxidative Stress, DNA, Cell Cycle/Cell Cycle Associated Proteins and Multidrug Resistance Proteins: Targets of Human Amniotic Membrane in Hepatocellular Carcinoma

The anticancer effects of human amniotic membrane (hAM) have been studied over the last decade. However, the action mechanisms responsible for these effects are not fully understood until now. Previously results reported by our team proved that hAM is able to induce cytotoxicity and cell death in hepatocellular carcinoma (HCC), a worldwide high incident and mortal cancer. Therefore, this experimental study aimed to investigate the cellular targets of hAM protein extracts (hAMPE) in HCC through in vitro studies. Our results showed that hAMPE is able to modify oxidative stress environment in all HCC cell lines, as well as its cell cycle. hAMPE differently targets deoxyribonucleic acid (DNA), P21, P53, β-catenin and multidrug resistance (MDR) proteins in HCC cell lines. In conclusion, hAMPE has several targets in HCC, being clear that the success of this treatment depends of a personalized therapy based on the biological and genetic characteristics of the tumor

Tolerogenic versus Inflammatory Activity of Peripheral Blood Monocytes and Dendritic Cells Subpopulations in Systemic Lupus Erythematosus

Abnormalities in monocytes and in peripheral blood dendritic cells (DC) subsets have been reported in systemic lupus erythematosus (SLE). We aim to clarify the tolerogenic or inflammatory role of these cells based on ICOSL or IFN-α and chemokine mRNA expression, respectively, after cell purification. The study included 18 SLE patients with active disease (ASLE), 25 with inactive disease (ISLE), and 30 healthy controls (HG). In purified plasmacytoid DC (pDC) was observed a lower ICOSL mRNA expression in ASLE and an increase in ISLE; similarly, a lower ICOSL mRNA expression in monocytes of ALSE patients was found. However, a higher ICOSL mRNA expression was observed in ASLE compared to HG in myeloid DCs. Interestingly, clinical parameters seem to be related with ICOSL mRNA expression. Regarding the inflammatory activity it was observed in purified monocytes and CD14(-/low) CD16(+) DCs an increase of CCL2, CXCL9, and CXCL10 mRNA expression in ASLE compared to HG. In myeloid DC no differences were observed regarding chemokines, and IFN-α mRNA expression. In pDC, a higher IFN-α mRNA expression was observed in ASLE. Deviations in ICOSL, chemokine, and IFN-α mRNA expression in peripheral blood monocytes and dendritic cells subpopulations in SLE appear to be related to disease activity

Prevalence of Vitamin D Deficiency and its Predictors in the Portuguese Population: a Nationwide Population-Based Study

Vitamin D deficiency is prevalent worldwide, but its prevalence is unknown in adult Portuguese population. In Portugal, 66% of adults present Vitamin D insufficiency/deficiency. Winter, living in Azores, older age, and obesity were the most important risk factors. It highlights the need of strategies to prevent vitamin D deficiency in Portugal. Objective: To estimate the prevalence and risk factors of vitamin D deficiency in the adult Portuguese population. Methods: Adults (≥ 18 years old) from the EpiReumaPt Study (2011-2013) were included. Standardized questionnaires on socio-demographic and lifestyle features were obtained. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were evaluated using ADVIA Centaur VitD competitive immunoassay (Siemens Healthineers) in 2015-2017 as 25 (OH)D Level 0: ≤ 10 ng/mL; Level 1: 11-19 ng/mL; Level 2: 20-29 ng/mL, and Level 3: ≥ 30 ng/mL. Weighted multinomial regression analysis was conducted to evaluate the association between socio-demographic and lifestyle variables and vitamin D status. Results: Based on weighted analysis, the estimated prevalence of levels of 25(OH)D ≤ 10, < 20, and < 30 ng/mL was 21.2, 66.6, and 96.4%, respectively. The strongest independent predictors of serum 25 (OH)D ≤ 10 ng/mL were living in the Azores archipelagos (OR 9.39; 95%CI 1.27-69.6) and having the blood sample collection in winter (OR 18.53; 95%CI 7.83-43.87) or spring (11.55; 95%CI 5.18-25.74). Other significant predictors included older age (OR 5.65, 95%CI 2.08-15.35), obesity (OR 2.61; 95%CI 1.35-5.08), current smoking (OR 2.33; 95%CI 1.23-4.43), and female gender (OR 1.9, 95%CI 1.1-3.28). Conversely, physical exercise (OR 0.48, 95%CI 0.28-0.81) and occasional alcohol intake (OR 0.48, 95%CI 0.29-0.81) were associated with a lower risk of 25(OH)D ≤ 10 ng/mL. Conclusion: Vitamin D deficiency/insufficiency [25(OH)D 60% of all Portuguese adults, with strong geographical and seasonal variation. This study highlights the need to critically assess the relevance of vitamin D deficiency as a public health problem and the urgent need for a wide and scientifically robust debate about the most appropriate interventions at the individual and societal levels.info:eu-repo/semantics/publishedVersio

Semaphorin4A-Plexin D1 Axis Induces Th2 and Th17 While Represses Th1 Skewing in an Autocrine Manner

Semaphorin (Sema)4A is a transmembrane glycoprotein that is elevated in several autoimmune diseases such as systemic sclerosis, rheumatoid arthritis and multiple sclerosis. Sema4A has a key role in the regulation of Thelper Th1 and Th2 differentiation and we recently demonstrated that CD4(+) T cell activation induces the expression of Sema4A. However, the autocrine role of Sema4A on Th cell differentiation remains unknown. Naive Th cells from healthy controls were cell sorted and differentiated into Th1, Th2 and Th17 in the presence or absence of a neutralizing antibody against the Sema4A receptor PlexinD1. Gene expression was determined by quantitative PCR and protein expression by ELISA and flow cytometry. We found that the expression of Sema4A is induced during Th1, Th2 and Th17 differentiation. PlexinD1 neutralization induced the differentiation of Th1 cells, while reduced the Th2 and Th17 skewing. These effects were associated with an upregulation of the transcription factor T-bet by Th1 cells, and to downregulation of GATA3 and RORgammat in Th2 cells and Th17 cells, respectively. Finally, PlexinD1 neutralization regulates the systemic sclerosis patients serum-induced cytokine production by CD4(+) T cells. Therefore, the autocrine Sema4A-PlexinD1 signaling acts as a negative regulator of Th1 skewing but is a key mediator on Th2 and Th17 differentiation, suggesting that dysregulation of this axis might be implicated in the pathogenesis of CD4(+) T cell-mediated diseases

Lysophosphatidic acid enhances survival of human CD34(+) cells in ischemic conditions

Several clinical trials are exploring therapeutic effect of human CD34(+) cells in ischemic diseases, including myocardial infarction. Unfortunately, most of the cells die few days after delivery. Herein we show that lysophosphatidic acid (LPA)-treated human umbilical cord blood-derived CD34(+) cells cultured under hypoxic and serum-deprived conditions present 2.2-fold and 1.3-fold higher survival relatively to non-treated cells and prostaglandin E2-treated cells, respectively. The pro-survival effect of LPA is concentration- and time-dependent and it is mediated by the activation of peroxisome proliferator-activator receptor γ (PPARγ) and downstream, by the activation of pro-survival ERK and Akt signaling pathways and the inhibition of mitochondrial apoptotic pathway. In hypoxia and serum-deprived culture conditions, LPA induces CD34(+) cell proliferation without maintaining the their undifferentiating state, and enhances IL-8, IL-6 and G-CSF secretion during the first 12 h compared to non-treated cells. LPA-treated CD34(+) cells delivered in fibrin gels have enhanced survival and improved cardiac fractional shortening at 2 weeks on rat infarcted hearts as compared to hearts treated with placebo. We have developed a new platform to enhance the survival of CD34(+) cells using a natural and cost-effective ligand and demonstrated its utility in the preservation of the functionality of the heart after infarction.info:eu-repo/semantics/publishedVersio

Membrane separation and characterisation of lignin and its derived products obtained by a mild ethanol organosolv treatment of rice straw

ABSTRACT: An organosolv process using ethanol-water was optimized in order to recover high quality lignin from rice-straw previously pre-treated by autohydrolysis at 210 °C. The results showed a selective and appreciable removal of lignin under very mild conditions and the highest delignification yield occurred at 30 °C. The lignin extracts were characterised using capillary zone electrophoresis (CZE), size exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FT-IR) and 31P-NMR, and two-dimensional heteronuclear single quantum correlation NMR spectroscopy (2D-HSQC NMR), which enabled the identification of low molecular weight lignins with a syringyl/guaiacyl ratio of about 0.74 containing phenolic compounds with potential bioactive properties. In order to separate the target compounds, membrane technology has been used and an enriched extract containing value-added phenolic compounds such as tricin, vanillin, ferulic acid and p-coumaric acid was obtained. High membrane efficiency (around 80%) was obtained for target compounds.info:eu-repo/semantics/publishedVersio