189 research outputs found
A NATUREZA ENQUANTO ATRAÇÃO E REPULSÃO NO MUNICÍPIO DE ANGRA DOS REIS – RJ
doi: 10.12957/geouerj.2011.248
Conceptual and empirical dimensions of students' evaluation-related goals
To clarify the current debate within achievement goal theory concerning performance goals, we suggest that there is more to students' evaluation-related goals than the concept of performance goals comprises.Goal theory identified three dimensions of performance goals: approach-avoidant, competition, and appearance concerns (Elliot & Harackiewicz, 1996; Grant & Dweck, 2003). However, whereas evaluation-related goals may include strong goal statements stressing competition and/or appearance, they mainly consist of weaker goal statements such as receiving positive evaluations or avoiding negative ones (Lemos, 1996). Moreover, research has questioned the very relevance of performance goals (Brophy, 2005; Lemos, 1996; Urdan, 2001). This study defined three main aims: to establish (1) the distinctiveness and (2) the relevance of competitive and appearance concerns (performance goals) within students' overall evaluation-related goals, and (3) whether approach and avoidant goals are empirically distinct. A pool of evaluation-related goals was formed combining three dimensions: approach-avoidance, appearance (present-absent), and competition (present-absent). From the eight resulting combinations, 2 refer to goals with appearance and competitive purposes, 2 to only appearance purposes, 2 to only competitive purposes, and 2 to evaluation goals (without reference to appearance or competition).120, fifth and sixth grade students from two city schools in the North of Portugal, answered the evaluation-related goals items (9 point Likert scale); two weeks later they also completed the personal goals scales of the PALS (Midgley et al, 2000).Principal component analysis confirmed that performance goals involving competition and/or appearance only partially cover the conceptual and empirical field of students' evaluation-related goals. Moreover, the analysis of goal priorities revealed that students focus mainly on getting positive evaluations and avoiding poor ones, and only to a smaller extent on competition
Efeito antiplaca e antiinflamatório de um gel contendo extrato de romã: estudo clínico duplo-cego em humanos
OBJECTIVES: The antiplaque and antigingivitis effects of a gel containing 10% Punica granatum Linn extract were evaluated using a 21-day partial-mouth experimental model of gingivitis. METHODS: 23 volunteers participated in this cross-over, double-blind study, carried out in 2 phases of 21 days each. For each period of the experiment, an acrylic toothshield was made for each volunteer to carry the test or placebo gel as well as to avoid brushing of the 4 experimental teeth (posterior teeth in the lower left quadrant). The subjects were randomly assigned to use either the placebo gel (control group) or the test gel (experimental group) and were instructed to brush the remaining teeth normally 3 times a day. On days 0 and 21, the visible plaque index (VPI) and gingival bleeding index (GBI) were recorded. RESULTS: The results did not show statistically significant difference between control and experimental groups for either of the indices (VPI and GBI). CONCLUSION: The gel containing 10% Punica granatum Linn extract was not efficient in preventing supragingival dental plaque formation and gingivitis.OBJETIVOS: O efeito antiplaca e antigengivite de um gel contendo extrato de romã a 10% foi avaliado utilizando um modelo de gengivite experimental parcial em humanos. MÉTODOS: 23 indivíduos participaram voluntariamente deste estudo cruzado, duplo-cego, compreendendo dois períodos de 21 dias cada um. Uma moldeira de acrílico foi confeccionada para cada participante, a qual foi utilizada como carreadora dos géis sobre a área a ser avaliada (hemiarco inferior esquerdo). Os sujeitos foram aleatoriamente designados para usar o gel placebo (grupo controle) ou o gel teste (grupo experimental), sendo instruídos a colocar o gel na moldeira e esta sobre os dentes teste, escovando os outros normalmente três vezes ao dia. No dia 0 e dia 21 os índices de placa visível (IPV) e índice de sangramento gengival (ISG) foram registrados. RESULTADOS: Os resultados não demonstraram diferença estatística significante entre os grupos controle e experimental para nenhum dos índices. CONCLUSÕES: O gel contendo extrato de romã a 10% não foi eficiente em evitar a formação de placa bacteriana supragengival e prevenir a inflamação gengival
Casbane diterpene as novel and natural antimicrobial agent against biofilm infections
Croton nepetaefolius is a plant native from northeastern Brazil and belongs to Euphorbiaceae family. The
essential oil of this plant is widely used in folk medicine from the treatment of gastrointestinal disorders to
the use as an antiseptic agent, with an antifungal action scientifically proven. The action of this plant has been
extensively explored by the scientific community, being the secondary metabolites, which are responsible
for their properties, alkaloids, diterpenes, and triterpenes. The aim of this study was to evaluate the ability
of the secondary metabolite, casbane diterpene (CD) (isolated of the species mentioned above), to inhibit
microbial growth and biofilm formation of several clinical relevant species (about 15 species among bacteria
and fungi). Minimal inhibitory concentration was assessed by the standard technique of microdilution and
biofilm inhibition was tested using microtiter plates with biomass quantification by crystal violet staining
method. It was found that the CD possessed biocidal and biostatic activity for the majority of the species
screened, with the minimal concentration active between 125 and 500 mg/L. Moreover, CD anti-biofilm action
was also observed for some of the species. In addition, it was noticed some biofilm formation inhibition even
when the planktonic growth was not significantly affected. In conclusion it can be speculated that casbane
diterpene shows potential to be a natural tool for the treatment of diseases caused by different infectious
microorganisms
Soybean (Glycine max) as a versatile biocatalyst for organic synthesis
A series of aliphatic and aromatic aldehydes and ketones were reduced using plant cell preparations of Glycine max seeds (soybean). The biotransformation of five aromatic aldehydes in water, at room temperature afforded the corresponding alcohols in excellent yields varying from 89 to 100%. Two prochiral aromatic ketones yielded the alcohol in very low conversion, 1% and to 4%; however with good enantiomeric excess (ee) of 99 and 79%, respectively. Additionally, three prochiral and one cyclic aliphatic ketones produced the corresponding alcohols in moderate yields varying from 10 to 58% and ee varying from 73 to 99%. Hydrolysis of two aromatic esters yielded the expected carboxylic acids in 49 and 66%. Most of the obtained alcohols have commercial value as cosmetic fragrances. Although, the enzymes present in soybean (reductase/lipase) has not been defined, the reaction is an important route for the preparation of pure alcohols and carboxylic acid, with low cost and environmental impact.Keywords: Glycine max, biocatalysis, bioreduction, aldehydes and ketones, ester hydrolysi
Avaliação do Consumo Alimentar Durante o Distanciamento Social Devido à Pandemia de COVID-19 em Belo Horizonte, Minas Gerais.
Objective: to analyse the eating habits of adults living in Belo Horizonte, Minas Gerais, during social distancing. Methodology: we applied a self-applicable questionnaire with questions based on Vigitel’s questionnaire and others related to stress and eating behavior. The participants received the link to Google forms via social media, they were people between the ages of 20 and 59 years old who were on par with the criteria of inclusion. The exclusion criteria included pregnant women, people who smoke, people who suffer from eating disorders, those in a dietetic or psychiatric treatment, people with a COVID-19 diagnosis and people who were not social distancing. The sample calculation was of 439 participants based on the effect size of 0,10. This value as calculated through a pilot sample with the test power of 80% and confidence interval of 90%, the program GPower 3.1 version was used to perform the sample computation. Results: 382 people answered the questionnaire, 68% of them were female and 32% were male. Around 69% of the participants were between the ages of 20 - 29 years old and 40,4% of them had not graduated from college yet. Women showed an increase of their consumption of sweets, pasta and highly processed foods related to stress. The produce consumption was inferior to the one shown in Vigitel from 2019, but the consumption of highly processed foods has shown an increase. Conclusion: The study concluded that the COVID-19 pandemic led to changes in the eating habits in the population of Belo Horizonte when compared to the Vigitel 2019 survey. The frequency of consumption of in-natura and least processed foods decreased and the increased consumption of highly processed foods. This one was linked to stress.Objetivo: Analisar o consumo alimentar durante o distanciamento social em adultos residentes em Belo Horizonte, Minas Gerais. Metodologia: Foi utilizado um questionário autoaplicável com questões retiradas da Vigitel 2019 e outras relacionadas ao estresse e comportamento alimentar. Os participantes receberam o link do questionário no Google forms via mídias sociais, esses eram entre a faixa dos 20 aos 59 anos de idade, que se enquadraram aos critérios de inclusão do estudo. Os critérios de exclusão foram: grávidas, alcoolista, fumantes, pessoas em tratamento dietético e/ou uso medicação psiquiátrica, indivíduos diagnosticados com transtorno alimentar e/ou com a COVID-19 durante a pandemia, além da população que não permaneceu em distanciamento social, saindo para atividades de natureza social. O cálculo amostral foi de 439 entrevistados feito com base em um tamanho de efeito de 0,10; valor esse calculado através de uma amostra piloto com o poder do teste de 80% e intervalo de confiança de 90%, a computação amostral foi realizada pelo programa GPower versão 3.1 . Resultados: Um total de 382 pessoas responderam ao questionário, destes 68% eram do sexo feminino e 32% do sexo masculino. Cerca de 69% estavam na faixa etária entre 20 e 29 anos de idade e 40,4% dos participantes possuíam ensino superior incompleto. Observou-se o aumento do consumo de doces, massas e ultraprocessados relacionados com o estresse pelas mulheres; já na população masculina observou-se o consumo inferior destes alimentos. A ingestão de hortaliças apresentada pelos participantes foi inferior ao resultado da VIGITEL de 2019, já o consumo de alimentos ultraprocessados foi superior. Conclusão: A pandemia causada pela COVID-19 levou a alterações nas práticas alimentares da população de Belo Horizonte, observando-se a diminuição da frequência do consumo de alimentos in-natura e minimamente processados e o aumento da ingestão de alimentos industrializados, relacionados ao estresse
Electrochemical determination of oncocalyxone A using an iron-phthalocyanine/iron-porphyrin modified glassy carbon electrode
The development of a highly sensitive voltammetric sensor for oncocalyxone A using a glassy carbon electrode modified with a bilayer iron(II) tetrasulfonated phthalocyanine (FeTSPc) and iron(III) tetra-(N-methyl-4-pyridyl)-porphyrin (FeT4MPyP) is described. The modified electrode showed high catalytic activity and stability for the oncocalyxone A reduction, provoking the anodic shift of the reduction peak potentials of ca. 30 mV and presenting much higher peak currents than those obtained on the bare GC electrode. A wide linear response range between 0.005-1.2 µmol L-1, with a sensitivity of 8.11 µA L µmol-1 and limits of detection (LOD) and quantification (LOQ) of 1.5 and 5 nmol L-1 were obtained with this sensor.Descreve-se, no presente trabalho, o desenvolvimento de um sensor voltamétrico altamente sensível para a oncocalixona A, utilizando-se eletrodo de carbono vítreo modificado com uma bi-camada de ftalocianina tetrassulfonada de ferro(II) (FeTSPc) e tetra-(N-metil-4-piridil)-porfirina de ferro(III) (FeT4MPyP). O eletrodo modificado apresentou alta atividade catalítica e estabilidade em relação à redução da oncocalixona, proporcionando deslocamento anódico de ca. de 30 mV e amplificação da corrente de pico, em relação a iguais parâmetros obtidos em eletrodo de carbono vítreo não modificado. Um ampla faixa linear de resposta entre 0.005-1.2 µmol L-1, com sensibilidade de 8.11 µA L µmol-1 e limites de detecção (LOD) e quantificação (LOQ) de 1.5 e 5 nmol L-1 foram obtidos, com o uso desse sensor.697703Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES
- …