Development of iridium porphyrin arrays by axial coordination trough N-bidentate ligand: Synthesis and evaluation of the optical, electrochemical and thermal properties

Several organic compounds have been used in optoelectronics devices; porphyrins, due to their interesting optical and electronic properties, have shown an attractive potential to be used on molecular electronics. Among other advantages, porphyrins easily coordinate with several metal ions, which allows the assembly with peripheral or axial ligands introducing new properties to the supramolecular porphyrin. In this work, a new metalloporphyrin system with 5,10,15,20-(tetra-p-tolyl)porphyrin (ttp) and iridium(III) where 4,4’-bipyridine (bpy) coordinate in the axial positions was successfully synthetized, through the formation of “shish kebab” structures. This new compound was characterized through ultraviolet-visible, proton nuclear magnetic resonance, Fourier-transform infrared and Raman spectroscopies, thermogravimetry, differential scanning calorimeter and cyclic voltammetry. The introduction of the bpy on the metalloporphyrin moiety exhibited important influence on the optical, thermal and electrochemical properties.The authors acknowledge the Portuguese Foundation of Science and Technology (TSSiPRO – TECHNOLOGIES FOR SUSTAINABLE AND SMART INNOVATIVE PRODUCTS – NORTE-01-0145-FEDER-000015) and UID/CTM/50025/2013 for the financial support.info:eu-repo/semantics/publishedVersio

Emprego de titulação potenciométrica e ferramentas quimiométricas para determinação de constituintes em amostras de silagem.

O ensilamento constitui um dos métodos mais seguros para armazenar o alimento para o gado durante inverno e secas prolongadas. Esse processo é alcançado por meio de fermentações que geram ácidos orgânicos e reduzem o pH do ambiente. Dos ácidos gerados, quanto maior for a concentração de ácido lático mais energética e agradável em relação ao sabor e ao aroma se torna a silagem para os animais. Sendo por isso a concentração desse ácido um importante critério para a verificação da qualidade da silagem produzida.1 Kowalky & Lindberg2 (1988) propuseram a determinação seletiva de ácidos orgânicos com pka muito próximos utilizando titulação potenciométrica e calibração por mínimos quadrados parciais (PLS) alcançando bons resultados para soluções padrão. Em vista disso, o objetivo desse trabalho foi propor um método simples e seletivo para a análise dos constituintes gerados no processo de ensilamento utilizando titulação potenciométrica e calibração por mínimos quadrados parciais. Neste resumo são apresentados os resultados obtidos para o ácido lático

Microbial treatment approaches for high-purity fructo-oligosaccharides production

The production of high-purity fructooligosaccharides (FOS), known as prebiotics, by sucrose fermentation using whole microbial cells has been recently explored. At the end of the fermentation process, FOS are present in mixture with small saccharides that are known to have an inhibitory effect of transfructosylating enzymes and to decrease the prebiotic activity of the mixture. This issue can be overcome by reducing the small saccharides present in FOS broth, which can be done using a combined microbial treatment, among others, improving as well the further purification of FOS by Simulated Moving Bed (SMB) chromatography. The main goal of this work was the use of combined microbial treatment approaches to improve FOS production and enhance a high purity FOS content. Aureobasidium pullulans and Saccharomyces cerevisiae were used combined to produce FOS and reduce the small sugars in the culture, respectively. FOS-producing microorganism was used free, immobilized to a non-conventional carrier or encapsulated in Ca-alginate beads, in mixture with the non-oligosaccharides consuming microorganism, free or encapsulated in Ca-alginate beads. A factorial design, considering three different variables, was performed, to select the microbial treatment approach through which increased FOS levels and yields can be obtained. The 38 assays were performed in shaken-flasks and the most suitable one was scaled-up to a 3L bioreactor. The inoculation time of S. cerevisiae showed to be the most relevant variable for FOS production, and the use of immobilized A. pullulans, mixed with encapsulated S. cerevisiae inoculated after 20h of fermentation, was the best combination, with statistical relevance (p<0.01), to obtain enhanced FOS concentration, percentage in the medium, yield and productivity. Results in bioreactor showed a higher fermentation time (20 to 25h) needed to obtain an increased maximal production of FOS (around 132 g.L-1) and yielded 0.70 ± 0.05 g of FOS per gram of initial sucrose. Also, the approach selected improved the percentage of FOS in the medium throughout the fermentation time, providing a pre-purified broth, with lower levels of mono-saccharides for further purification by SMB

Maternal depression and offspring mental health at age 5: MINA-Brazil cohort study

OBJECTIVE: To identify longitudinal patterns of maternal depression between three months and five years after child’s birth, to examine predictor variables for these trajectories, and to evaluate whether distinct depression trajectories predict offspring mental health problems at age 5 years. METHODS: We used data from the Maternal and Child Health and Nutrition in Acre (MINA-Brazil) study, a population-based birth cohort in the Western Brazilian Amazon. Maternal depressive symptoms were assessed with the Edinburgh Postnatal Depression Scale (EPDS) at 3 and 6–8 months, and 1 and 2 years after delivery. Mental health problems in 5-year-old children were evaluated with the Strengths and Difficulties Questionnaire (SDQ) reported by parents. Trajectories of maternal depression were calculated using a group-based modelling approach. RESULTS: We identified four trajectories of maternal depressive symptoms: “low” (67.1%), “increasing” (11.5%), “decreasing” (17.4%), and “high-chronic” (4.0%). Women in the “high/ chronic” trajectory were the poorest, least educated, and oldest compared with women in the other trajectory groups. Also, they were more frequently multiparous and reported smoking and having attended fewer prenatal consultations during pregnancy. In the adjusted analyses, the odds ratio of any SDQ disorder was 3.23 (95%CI: 2.00–5.22) and 2.87 (95%CI: 1.09–7.57) times higher among children of mothers belonging to the “increasing” and “high-chronic” trajectory groups, respectively, compared with those of mothers in the “low” depressive symptoms group. These differences were not explained by maternal and child characteristics included in multivariate analyses. CONCLUSIONS: We identified poorer mental health outcomes for children of mothers assigned to the “chronic/severe” and “increasing” depressive symptoms trajectories. Prevention and treatment initiatives to avoid the adverse short, medium, and long-term effects of maternal depression on offspring development should focus on women belonging to these groups

Degradabilidade in situ da matéria seca e proteína bruta das silagens de seis genótipos de sorgo (Sorghum bicolor (L.) Moench) em diferentes estádios de maturação.

In order to evaluate the in situ degradability of the dry matter (DM) and crude protein (CP) of silages of six sorghum genotypes in different stages of maturation, four fistulated crossbred Holstein-Zebu steers, fed with grass hay ad libitum, were utilized. The silage samples were dried and milled at 5 mm screen and 5 g of each sample was placed in 12x18 cm nylon bags with a 50 micro m porous size, and were introduced into the fistulas. After incubation (6, 12, 24, 48, 72 and 96 h), the nylon bags were removed, the samples from the same genotype, animal and time of incubation were transformed in a homogenous pool and milled at 1 mm screen, and stored for further analysis of DM and CP. It used the split-split plot design in which the parcels contained the silages of the different genotypes. In this study, there were differences in DM and CP disappearance of the sorghum silages, although these cannot be attributed to the percentage of grains in the different genotypes. The age of the plant influenced the effective degradability of digestible fractions, benefiting early stages.