Determinação da acidez de substâncias húmicas de diferentes ambientes: avaliação da metodologia empregada

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em Química.Grupos funcionais ácidos (carboxílicos e fenólicos) de Substâncias Húmicas - SH de diferentes ambientes foram quantificados através do método de Schnitzer e Gupta. As SH foram previamente caracterizadas por análise elementar e por espectroscopia no infravermelho. Os dados de análise estrutural e espectral apresentaram as tendências esperadas para cada tipo de material. Diferentemente a esses, os resultados de acidez não mostraram as tendências esperadas para cada tipo de material, como as SH aquáticas apresentando valores excessivamente altos de acidez fenólica, por exemplo. Assim, uma série de experimentos, usando compostos modelos, foi realizada para testar possíveis interferências na determinação da acidez de SH. Como modelo de SH foram utilizadas diferentes misturas contendo três ácidos benzenocarboxílicos (ácido 2,4-dihidroxibenzóico; ácido 3,5-dihidroxibenzóico; ácido ftálico) e dois peptídeos (DL-alanil-DL-alanina; glicil-L-leucina). Os resultados mostraram que, na ausência de peptídeo, grupos fenólicos com valores de pKa muito altos não são detectados na reação com o Ba(OH)2 e os resultados obtidos não representam a concentração real dos grupos ácidos. Para as misturas contendo peptídeo, os resultados relativos à acidez total, são distorcidos principalmente porque nas condições severas da reação com o Ba(OH)2 ocorre a hidrólise do peptídeo, consumindo um grupo hidroxila extra, aumentando artificialmente a acidez fenólica. Tais condições não são minimizadas pela redução do tempo de reação. Assim, os valores de acidez obtidos para as amostras reais não têm um significado absoluto, mas devem ser usados somente em comparações com amostras que tenham analisadas pelo mesmo método

Caracterização química e reatividade de substâncias húmicas, solos e turfas

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em QuímicaAmostras de solos, turfas e suas substâncias húmicas (SH) foram caracterizadas através de análise termogravimétrica (TG), análise elementar, espectroscopia de infravermelho (IV) e ressonância magnética nuclear de 13C (RMN 13C). Os resultados demonstraram que as amostras de matéria orgânica (MO) apresentaram uma estrutura mais alifática e rica em polissacarídeos do que suas SH. Entretanto, as razões atômicas assim como a IV e RMN 13C puderam ser usadas para caracterizar e diferenciar amostras de MO. A acidez de SH de ambientes distintos foi determinada pela titulação indireta. Os resultados geraram dúvidas com relação à validade da metodologia e de possíveis interferências ocasionadas pelas características das amostras. Desta forma, experimentos foram idealizados para testar a validade dos valores de acidez de SH determinados por diferentes métodos e tratados por diferentes modelos matemáticos. Os resultados de acidez mostraram dependência do modelo aplicado e das condições experimentais. A remoção do azul de metileno (AM), do 17ß-estradiol e do 17a-etinilestradiol de soluções aquosas pela turfa foi avaliada. Para o AM, a remoção foi maior para as soluções diluídas. Para os hormônios, a turfa apontou ser uma alternativa viável nos testes de adsorção. A turfa mostrou-se eficiente, demonstrando a sua potencialidade para a recuperação de efluentes contaminados com estes compostos

Atitudes dos estudantes de enfermagem em relação à pessoa idosa: Nursing students’ attitudes toward older people

OBJECTIVE: To identify nursing students’ attitudes toward older people. METHOD: Second-year undergraduate nursing students were invited to complete a questionnaire at the beginning of the geriatric nursing curricular unit. A quantitative study was conducted by administering the validated Portuguese version of Kogan’s attitudes toward old people scale (KOAP). RESULTS: The sample included 39 students who answered the data collection instrument. The mean KOAP score was 135.56, which was slightly above the median value (119). No statistically significant relationships were found between any of the variables: gender, age, experience with older people, and living with older people. CONCLUSIONS: The nursing students’ mean score for attitude toward older people was slightly positive, which could serve as a starting point for the development of an intervention to modify their attitudes with respect to aging.info:eu-repo/semantics/publishedVersio

An aging simulation game’s impact on the attitudes of Nursing students

Background & Aim: The aging of the population poses new challenges, among others, a greater concern with the teaching of geriatrics and gerontology, especially to future health professionals. The simulation game "Aging Nursing Game" ® was used with the objective of evaluating the impact of an aging simulation game on nursing students' attitudes towards the elderly. Methods & Materials: A pre-test and post-test type quasi-experimental study was performed, without control group. The research was developed between February and July 2018. The subjects of this study were second-year undergraduate nursing students. A game was used as an intervention. To measure the effectiveness of the game, a questionnaire was applied before and after the intervention. The data collection instrument consisted of a questionnaire composed of two parts, the first part for sociodemographic characterization, and another consisting of the Portuguese version of the Kogan Scale (KAOP). Results: The sample consisted of 45 undergraduate nursing students from the 2nd year corresponding to 75% of the population. The attitude towards the elderly person improved significantly before and after the intervention. Of the 34 items on the Kogan Scale (KAOP), 21 improved significantly. Conclusion: The simulation game has proven to be effective in teaching students changing attitudes towards the elderly (p <0.05).info:eu-repo/semantics/publishedVersio

Combined therapy with m-TOR-dependent and -independent autophagy inducers causes neurotoxicity in a mouse model of Machado-Joseph disease

A major pathological hallmark in several neurodegenerative disorders, like polyglutamine disorders (polyQ), including Machado-Joseph disease (MJD), is the formation of protein aggregates. MJD is caused by a CAG repeat expansion in the ATXN3 gene, resulting in an abnormal protein, which is prone to misfolding and forms cytoplasmic and nuclear aggregates within neurons, ultimately inducing neurodegeneration. Treatment of proteinopathies with drugs that up-regulate autophagy has shown promising results in models of polyQ diseases. Temsirolimus (CCI-779) inhibits the mammalian target of rapamycin (m-TOR), while lithium chloride (LiCl) acts by inhibiting inositol monophosphatase, both being able to induce autophagy. We have previously shown that chronic treatment with LiCl (10.4 mg/kg) had limited effects in a transgenic MJD mouse model. Also, others have shown that CCI-779 had mild positive effects in a different mouse model of the disease. It has been suggested that the combination of mTOR-dependent and -independent autophagy inducers could be a more effective therapeutic approach. To further explore this avenue toward therapy, we treated CMVMJD135 transgenic mice with a conjugation of CCI-779 and LiCl, both at concentrations known to induce autophagy and not to be toxic. Surprisingly, this combined treatment proved to be deleterious to both wild-type (wt) and transgenic animals, failing to rescue their neurological symptoms and actually exerting neurotoxic effects. These results highlight the possible dangers of manipulating autophagy in the nervous system and suggest that a better understanding of the potential disruption in the autophagy pathway in MJD is required before successful long-term autophagy modulating therapies can be developed.Fundação para a Ciência e Tecnologia through the projects [FEDER/FCT, POCI/SAU-MMO/60412/2004], [PTDC/SAU-GMG/64076/2006]. This work was supported by Fundação para a Ciência e Tecnologi

Processo de obtenção de membrana polimérica, membrana polimérica e uso da membrana polimérica

Universidade Federal do Rio Grande do SulQuímicaDepositad

Micro/mesoporous LTL derived materials for catalytic transfer hydrogenation and acid reactions of bio-based levulinic acid and furanics

The biomass-derived platform chemicals furfural and 5-(hydroxymethyl)furfural (HMF) may be converted to α-angelica lactone (AnL) and levulinic acid (LA). Presently, LA (synthesized from carbohydrates) has several multinational market players. Attractive biobased oxygenated fuel additives, solvents, etc., may be produced from AnL and LA via acid and reduction chemistry, namely alkyl levulinates and γ-valerolactone (GVL). In this work, hierarchical hafnium-containing multifunctional Linde type L (LTL) related zeotypes were prepared via top-down strategies, for the chemical valorization of LA, AnL and HMF via integrated catalytic transfer hydrogenation (CTH) and acid reactions in alcohol medium. This is the first report of CTH applications (in general) of LTL related materials. The influence of the post-synthesis treatments/conditions (desilication, dealumination, solid-state impregnation of Hf or Zr) on the material properties and catalytic performances was studied. AnL and LA were converted to 2-butyl levulinate (2BL) and GVL in high total yields of up to ca. 100%, at 200°C, and GVL/2BL molar ratios up to 10. HMF conversion gave mainly the furanic ethers 5-(sec-butoxymethyl)furfural and 2,5-bis(sec-butoxymethyl)furan (up to 63% total yield, in 2-butanol at 200°C/24 h). Mechanistic, reaction kinetics and material characterization studies indicated that the catalytic results depend on a complex interplay of different factors (material properties, type of substrate). The recovered-reused solids performed steadily.publishe

Profiling microglia in a mouse model of Machado-Joseph disease

Microglia have been increasingly implicated in neurodegenerative diseases (NDs), and specific disease associated microglia (DAM) profiles have been defined for several of these NDs. Yet, the microglial profile in Machado–Joseph disease (MJD) remains unexplored. Here, we characterized the profile of microglia in the CMVMJD135 mouse model of MJD. This characterization was performed using primary microglial cultures and microglial cells obtained from disease-relevant brain regions of neonatal and adult CMVMJD135 mice, respectively. Machine learning models were implemented to identify potential clusters of microglia based on their morphological features, and an RNA-sequencing analysis was performed to identify molecular perturbations and potential therapeutic targets. Our findings reveal morphological alterations that point to an increased activation state of microglia in CMVMJD135 mice and a disease-specific transcriptional profile of MJD microglia, encompassing a total of 101 differentially expressed genes, with enrichment in molecular pathways related to oxidative stress, immune response, cell proliferation, cell death, and lipid metabolism. Overall, these results allowed us to define the cellular and molecular profile of MJD-associated microglia and to identify genes and pathways that might represent potential therapeutic targets for this disorder.This work was supported by Fundação para a Ciência e a Tecnologia (FCT) (PTDC/NEUNMC/3648/2014) and COMPETE-FEDER (POCI-01-0145-FEDER-016818). It was also supported by Portuguese funds through FCT in the framework of the Project POCI-01-0145-FEDER-031987 (PTDC/MED-OUT/31987/2017). A.B.C. was supported by a doctoral fellowship from FCT (PD/BD/ 127828/2016). S.P.N. was also supported by FCT (PD/BD/114120/2015). Work in the JBR laboratory was financed by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operational Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT in the framework of the Project POCI-01-0145- FEDER030647 (PTDC/MED-NEU/31318/2017). This work was funded by ICVS Scientific Microscopy Platform, member of the national infrastructure PPBI (Portuguese Platform of Bioimaging) (PPBIPOCI-01-0145-FEDER-022122), and by National funds, through FCT—project UIDB/50026/2020 and UIDP/50026/2020

First stage of the development of an eco-friendly detergent formulation for efficient removal of carbonized soil

Detergent formulations for cleaning a carbonized soil-degreasers-typically comprise surfactants, organic solvents, phosphate-based cleaning agents, and alkaline agents, which results in high pH values (>11) that raise human and environmental risks. It is important to develop eco-friendly and safer degreasers, while maintaining their cleaning efficiency. In this work, simple degreaser formulations, with a pH below 11 and without phosphates, were developed by using a mixture of solvent, surfactant, and water to remove carbonized soil. The efficiency of the new degreaser formulations (with 5 wt% solvent, 5 wt% nonionic or ionic surfactant, and 90 wt% water) was evaluated by an abrasion test in the removal of carbonized soil from ceramic and stainless steel surfaces and compared with a commercial product. The results obtained show that the formulations comprising isopropylene glycol (IPG) with C11-C13 9EOs and diethylene glycol butyl ether (BDG) with octyltrimethylammonium octanoate ([N1118][C8O2]) present the best cleaning efficiency for both surfaces. The composition of these formulations was optimized for each surface using a mixture design. The resulting formulations, despite having a simpler composition, a pH lower than 11, and being phosphate-free, presented a cleaning efficiency equal or slightly higher than the commercial control. These results show that it is possible to design degreasers that are much less aggressive to the environment and user, while simultaneously fulfilling the market requirements.publishe

Avaliação de risco a casais homossexuais

Poster apresentado no IX Congresso Iberoamericano de Psicologia / 2º Congresso da Ordem dos Psicólogos Portugueses. Lisboa, 9-13 Setembro de 2014