Büchwald-Hartwig reaction applied to synthesis of new luminescent liquid crystal triarylamines derived from isoxazoles

© 2015 Taylor & Francis Group, LLC. The present work describes the synthesis and characterization of novel series of triarylamines isoxazoles (TAA) addressed to the organic photovoltaic materials. Diarylisoxazoles were synthesized by sequential [3+2] 1,3-dipolar cycloaddition reaction between arylnitrile oxides and selected arylalkenes followed by MnO2-oxidation. Isoxazoles were coupled to diarylamines by Büchwald-Hartwig reaction to afford desired compounds 6a-k. Some TAA display liquid-crystalline behaviour and UV-Vis absorption and fluorescence emission were analysed for all samples of TAA 6a-k

Geometry, stochastic calculus and quantum fields in a non-commutative space-time

The algebras of non-relativistic and of classical mechanics are unstable algebraic structures. Their deformation towards stable structures leads, respectively, to relativity and to quantum mechanics. Likewise, the combined relativistic quantum mechanics algebra is also unstable. Its stabilization requires the non-commutativity of the space-time coordinates and the existence of a fundamental length constant. The new relativistic quantum mechanics algebra has important consequences on the geometry of space-time, on quantum stochastic calculus and on the construction of quantum fields. Some of these effects are studied in this paper.Comment: 36 pages Latex, 1 eps figur

Sex-related dietary changes of Portuguese university students after migration to London, UK

Aim: To assess the changes in eating habits and food choice motives of Portuguese university students after migration to London, according to sex. Methods: Fifty-five Portuguese university students (52.7% female) from 12 randomly selected London universities underwent a face-to-face interview. Trained interviewers administered a structured questionnaire comprising questions on socio-demographic characteristics, the frequency of consumption of selected food and beverage items, and the motives underlying food choices regarding Portugal and London practices. Results: Some dietary changes occurred in both male and female Portuguese students such as a decrease in the intake of red meat, fish, pastries and vegetable soup, and an increase in the intake of hamburger and tea with milk. Men also reported a decrease in the intake of cheese, dairy desserts, eggs, smoked sausages, ham, sweet spreads, potatoes, rice and fresh fruit, and an increase in the intake of bacon. For women, the consumption frequency of chips and chocolate increased and of vegetables decreased. Regarding food choice, the motives related to food purchasing and preparation became more important after migration to London for both sexes. The importance of nutritional information for women and weight control for men also increased after migration. Conclusions: A shift from a Mediterranean diet towards a more Western diet was observed after migration. Men were more likely to change their dietary habits whereas women were more likely to maintain. Food choice in London was greatly influenced by food purchasing and preparation

Chrono-Nutrition: The Relationship between Time-of-Day Energy and Macronutrient Intake and Children's Body Weight Status

The time of eating has been considered to have an important role in weight regulation. However, it is unknown if there are specific daily patterns of energy and macronutrient distribution that could be more beneficial for metabolic outcomes, especially obesity. This study aimed to assess the effect of time-of-day energy and macronutrient intake at 4 y of age on the weight status at 7 y of age. The study sample included 1961 children from the population-based birth cohort Generation XXI, with data on 3-day food diaries at 4 y and body mass index (BMI) z-scores at 7 y. Dietary patterns based on the collected data were obtained for the distribution of energy and macronutrients across eating occasions. Having a relatively higher energy intake at lunch and supper (OR = 1.19, 95% CI = 1.05 to 1.34) or at mid-afternoon (OR = 1.18, 95% CI = 1.05 to 1.34) at 4 y was associated with higher odds of becoming overweight/obese at 7 y. A relatively higher intake of fat at lunch was positively associated with later children’s odds for being overweight or obese (OR = 1.17, 95% CI = 1.03 to 1.32). These associations were independent of the effect on children’s eating behaviors related to appetite. Our results also show a detrimental relation between skipping breakfast and eating late in the day and children’s body weight. Considering all daily eating occasions, a higher proportion of energy and macronutrient intake at the main meals and a lower proportion during the afternoon and evening seems to be more beneficial for children’s weight. These results emphasize the important role of daily food intake rhythm on excessive weight gain in childhood

On the optimal control of a cascade of hydro-electric power stations

In this paper we consider a model for a cascade of hydroelectric power stations where some of the stations have reversible turbines. The objective of our work is to optimize the profit of power production satisfying restrictions on the water level in the reservoirs. The problem is considered in the framework of discretetime optimal control and is solved using numerical methods. The optimization uses real data of market prices of electricity, water levels at the reservoirs, and water flows in different types of days

Isolamento e caracterização de bactérias celulolíticas de serrapilheira da Caatinga.

Resumo: O bioma Caatinga, ainda pouco estudado quanto a biodiversidade microbiana e bioprospecção, pode representar uma nova frente para descoberta de microrganismo de interesse biotecnológico. Dentro desse enfoque, este trabalho teve por finalidade isolar e caracterizar bactérias celulolíticas da Caatinga visando uma possível aplicação na indústria. Após isolamento em meio solido, foi realizada seleção das linhagens com capacidade de degradar celulose. Em seguida, após obtenção a melhor linhagem bacteriana, foi realizada a determinação da atividade de celulase total (FPase) adicionando papel filtro como substrato e atividade de endoglucanase (CMCase) com CMC como substrato. Um total de 73 bactérias foram isoladas e, destas, 34% apresentaram halo de degradação da celulose. O isolado 6.1 bac-15 foi o que apresentou o maior halo de degradação de celulose (29,5 mm± 0,288). Com relação à atividade de celulase total, a linhagem apresentou alta atividade enzimática (0,043 U.ml-1). Para a endoglucanase, o pico de atividade também foi observado após 4 horas, com valor de 0,80 U.ml-1. Após identificação do isolado por sequenciamento da região 16S DNA e otimização do processo, o isolado poderá servir futuramente para aplicações em processos industriais. Abstract: The Bioma Caatinga (white forest) which can be useful for biotechnological purposes can harbor thermotolerant microorganism by use biotechnology. This study was conducted to isolate and evaluate bacteria able to degrade cellulose obtained from semiarid region, in northeast Brazil. After the isolation, it was conduced the screening of strains for their ability to degrade cellulose in solid medium with carboxymethylcellulose (CMC). After the selection of the best isolate; the determination of total cellulase activity in filter paper (FPase) and endoglucanase (CMCase) on CMC as substrate was performed. A total of 73 bacteria were isolated and among them, 34% showed degradation of the polymer when stained with Gram iodine solution. The isolate 6.1 bac-15, showed the largest cellulose degradation halo (29,5 mm± 0,288). Regarding activity of the total cellulase, after a 4 hour-period incubation, the highest enzyme activity was observed (0,043 U.ml-1). For endoglucanase, the highest activity was also observed after 4 hours, with value of 0,80 U.ml-1. After the identification of the strain by sequencing of 16S DNA and optimization of the process, this bacterial stain could serve for future applications in industrial processes