711 research outputs found
Reducing social inequalities in the oral health of an adult population
The objective of this study was to evaluate the association between social inequality indicators and oral health conditions in an adult population. This prospective cohort study assessed a probabilistic sampling of adults (aged 20-64 years) living in Piracicaba, São Paulo, Brazil. Oral examinations were performed in 2011 and 2015, conducted at home, and used the decay-missing-filled (DMFT) index of permanent teeth, the Community Periodontal Index (CPI), and the visible biofilm criterion. A questionnaire was administered to determine demographic and socioeconomic aspects and dental services used, and collect oral health-related quality of life (OHRQoL) data. Social inequality indicators were evaluated according to social class (high, middle or low) and type of dental service used (public, health insurance or private), and compared with oral health conditions (visible biofilm, DMFT and incidence of tooth loss, periodontal pockets and bleeding, and OHRQoL), evaluated between 2011 and 2015. Analysis using chi-squared or Fisher tests (p < 0.05) and Cochran's Q test was conducted separately for each category analyzed between 2011 and 2015 (p < 0.05). A total of 143 adults who participated in an earlier study were examined after four years of follow-up. Although the occurrence of oral disease did not decrease over the study period (4 years), there was a reduction in inequality among lower social classes in regard to presence of tooth decay and oral health impact on self-perceived quality of life between 2011 and 2015 (p < 0.05). These results suggest that the Brazilian National Oral Health Policy has achieved its principles, especially that of greater equity33COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2014/15184-22009/16560-0; 2011/00545-
Extensional flow behaviour of natural fibre-filled dough and its relationship with structure and properties
There is an increasing awareness about the role of fibres as multifunctional substances, positively affecting the activity of the human body. From
the structural point of view, insoluble fibres are known to have a strong impact on food texture. This work is part of a broader project aimed at
understanding the role of fibres from different sources in traditional cookies delectableness. The impact on cookie dough characteristics, when
enriched with dietary fibre, was evaluated by dynamic oscillatory tests, transient uniaxial extensional viscosity measurements and texture profile
analysis. Three different sources of fibre were added: oat from cereals, orange from fruits and pea from legumes, at contents ranging from 0 to 10 g.
In terms of processibility, there were serious difficulties in processing some of these doughs, especially those with fibre addition levels over 8 g
for oat and orange and 9–10 g for pea. However, the results for the mechanical spectra of these doughs are similar to that of the standard dough
without fibre. Tests in compression with a 4mm cylinder in a 25mm flask filled with dough showed to be more sensitive than oscillatory tests
but still the results were somewhat difficult to interpret in terms of describing the differences in the processing behaviour of these doughs. Thus,
extensional uniaxial tests were performed (for the first time in this type of materials, i.e., with no developed gluten) and showed to be suitable to
describe the modification in dough structure, showing an increase of extensional viscosity for the dough with orange or oat fibre at levels of 4, 8
and 10 g, whereas for the pea fibre dough, no significant changes on the extensional behaviour were observed for formulations with up to 10 g of
fibre, which was in general agreement with the processibility studies
Simultaneous determination of ethanol and methanol in fuel ethanol using cyclic voltammetry
AbstractA new and simple strategy for the simultaneous determination of ethanol and methanol in fuel ethanol using cyclic voltammetry at a gold electrode is reported. A fuel ethanol aliquot was added into an electrochemical cell containing 0.5molL−1 NaOH and 0.1% (v/v) of methanol as the electrolyte and both analytes were determined using cyclic voltammetry. Ethanol was selectively detected at +0.19V and both compounds were detected at +1.20V. Current subtraction (using a correction factor) could be used for the selective determination of methanol. The limits of detection were estimated to be 0.028% and 0.045% (v/v) for ethanol and methanol, respectively. The proposed method presented similar results to those obtained by gas chromatography at a 95% confidence level
Massive 3+1 Aharonov-Bohm fermions in an MIT cylinder
We study the effect of a background flux string on the vacuum energy of
massive Dirac fermions in 3+1 dimensions confined to a finite spatial region
through MIT boundary conditions. We treat two admissible self-adjoint
extensions of the Hamiltonian. The external sector is also studied and
unambiguous results for the Casimir energy of massive fermions in the whole
space are obtained.Comment: 12 pages, 5 figures, LaTe
Genetic Divergence Among Accessions Of Cassava (manihot Esculenta Crantz) Sampled In The Tapajós Region, State Of Pará, Using Agronomic Characters And Microsatellite Markers
The aim of this work was to estimate the genetic divergence among accessions of cassava sampled in the Tapajós region in the State of Pará, Brazil, and conserved at the Regional Germplasm Bank of Eastern Amazon, using agronomic descriptors and molecular markers. Twenty-two accessions of cassava were evaluated in the field for two successive years, based on six agronomic descriptors in twelve-months-old plants without a specific experimental design. Accessions were also evaluated with eleven microsatellite loci in an automatic DNA analyser. Descriptive and multivariate statistical analyses were applied. Based on principal components analysis, the character weight of the aerial portion of the plant contributed most to the phenotypical variation. The six traits were used in the analysis of genetic dissimilarity between accessions, and the correlation between matrices generated by morphological and molecular data was estimated. The matrices of genetic dissimilarity were used in the construction of dendrograms using the UPGMA method. We observed a high variation of agronomical descriptors and molecular markers evaluated, which were capable to separate the accessions into distinct groups. A weak positive correlation was detected among the two matrices of genetic distances, which indicates the possibility to explore the genetic diversity using crossings and accessions Amarelinha 36 and Olho roxo 13 are divergent and potentially promising for the generation of heterotic hybrids.3752989300
Behaviour of the antioxidant tert-butylhydroquinone on the storage stability and corrosive character of biodiesel
AbstractThe behaviour of the antioxidant tert-butylhydroquinone (TBHQ) on the storage stability of biodiesel was investigated. Storage conditions were simulated through static immersion corrosion tests in biodiesel (with and without TBHQ) using copper coupons. Measurements of oxidation stability (Rancimat induction period) and metal release at different stages of corrosion were performed. After 24h of the static immersion test, the neat and TBHQ-doped biodiesels presented induction times below the EN 14214 limit (6h). Copper release was more intense in the neat biodiesel which evidenced that TBHQ retarded the corrosion process as a corrosion inhibitor. Ion trap–time-of-flight mass spectrometry (IT–TOF-MS) revealed the presence of considerable amounts of tert-butylquinone (TBQ) in the TBHQ-doped biodiesel exposed to the corrosion process. As TBHQ molecules adsorb at the copper surface to inhibit corrosion, these molecules are catalytically oxidised to TBQ. IT–TOF-MS also indicated the formation of new molecules of high molecular weight only presented in the TBHQ-doped biodiesel deteriorated by the corrosion process. MS2 spectra gave clear evidence of the formation of new complexes between free radicals of long-chain molecules (fatty acid derivatives) and TBQ radicals during biodiesel deterioration
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