59 research outputs found
Exploratory Analytical Study of a 20th century Portuguese Mural Painting by Julio Resende (1917-2011)
This paper unveils for the first time the technical and material features of the mural painting entitled Pentecost’s, executed by the Portuguese artist Julio Resende in 1955. The painting depicting twelve Apostles covers the altarpiece of a small church in the countryside of Évora (southern Portugal) and it was rediscovered in 2013 by art historians. The research was carried out with both non-invasive and micro-destructive techniques. In situ examination included technical photography in visible (Vis/Vis-RAK) and in infrared (NIR) light range, ultraviolet induced visible fluorescence (UVF), portable optical microscopy, visible spectrophotometry and handheld energy dispersive X-ray fluorescence spectroscopy (hXRF). Further analysis on paint layers micro-samples were undertaken by dark field optical microscopy (OM), scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM-EDS) and micro-Fourier transform infrared spectroscopy (μ-FTIR). According to the acquired data, the mural was executed in a fresco technique (true and most likely lime fresco). Full size cartoons and handmade sketches were used for transferring the composition to the wall. No traces of organic binder were found with the analytical setup and the analysis of paint layers revealed the use of cobalt blue, a wide range of ochres, chromium green, green earth and barium white. The use of chrome orange and cadmium-based pigments are hypothesized
An Insight into the Green Deteriorated Paint Layers at the Maritime Station of Alcântara (Lisbon): an Archeometric Study
This study reports the first results of the analysis carried out in 2022 on deteriorated green paint layers from the mural paintings made by Almada Negreiros at the Maritime Station of Alcantara, in Lisbon (Portugal). These murals painted in 1945 are one of the most emblematic painting sets done by the modernist artist and exhibit a bright chromatic palette that displays different states of conservation, with the green paint layers particularly damaged, showing severe flaking and powdering in the lightest shades.
To understand the decay phenomenon, in-situ and laboratory analyses were done in an attempt to identify the green chromophores, the painting technique, and the decay agents causing the visible degradation. The analytical setup comprised in-situ technical photography (Vis, Vis-Rak, and UVF), handheld optical microscopy (h-OM), handheld energy dispersive X-ray fluorescence (h-EDXRF), colorimetry, and spectrophotometry in the visible light range. Microsamples of selected paint layers from deteriorated and stable green areas were collected and further analysed in the laboratory by optical microscopy in visible and ultraviolet modes (OM-UV-Vis), variable pressure scanning electron microscopy coupled with energy dispersive spectrometry (VP-SEM-EDS), micro-X-ray diffraction (μ-XRD), micro-Fourier-transform infrared spectroscopy (μ-FT-IR) and micro-Raman spectroscopy.
Results show the presence of both natural and industrial synthetic organic pigments, such as green earths and PG8, used alone or in mixtures with other chromophores (e.g., Fe-based yellow and red pigments, bone and carbon black, ultramarine blue, and the synthetic green PG1 and the yellow PY1). Concerning the decay phenomena, the main hypothesis for the powdering and flaking of the green paint layers is the activity of calcium sulphates (e.g., gypsum), which probably originated from both intrinsic and extrinsic sources and whose presence was found to be widespread in all the microsamples analyzed
Marta Buchaca : una lectura global de la seva obra
El treball en qüestió pretén de fer una anàlisi global de l'obra de Marta Buchaca: en primer lloc, hem examinat les diferents obres que ha publicat a partir de les seves temàtiques i eixos principals -les relacions afectives i la solitud-; en segon lloc, hem mirat si presenten un enfocament feminista mitjançant l'anàlisi dels personatges femenins de la seva obra, com també a partir de les desigualtats de gènere que s'hi presenten i, en concret, ens hem centrat en Només una vegada (2018), per poder examinar a fons el tema de la violència de gènere a partir dels personatges, l'espai i el temps
Prevalence of diabetes-associated gene variants and its association with blood glucose levels in the Algarve population, Portugal
The global rise in incidence of type 2 (T2D) has been called a pandemic, constituting a major public health concern.
Although environmental factors play a substantial role in the etiology of T2D, genetic susceptibility has been
established as a key component in T2D risk. Given the absence of studies regarding the prevalence of T2D associated
variants in the Portuguese population, our aim was to determine the prevalence of disease-associated variants and
determine its relative contribution to this phenotype. For this purpose, we have recruited 221 individuals (93 males
and 128 females), between 26-91 years old (mean age 57.1), who were enrolled in the Health Centre of S. Brás de
Alportel (Algarve). For each participant, we have measured total glucose levels and collected DNA. In addition, each
participant has answered an exhaustive questionnaire including socio-demographic information, health history and
lifestyle. We have selected and analysed three of the most significant loci previously reported to be associated with
T2D in Caucasian populations (TCF7L2 rs7903146, PARPG rs1801282 and FTO rs9939609) and performed an
association analysis between glucose levels in this population and the selected gene variants. The mean total
population glucose level was 103.85±35.3 g/dl. We found a significant difference in the mean glucose levels between
males (mean = 111.5±51.3 g/dl) and females (mean = 98.4±17.6 g/dl) (Mann-Whitney test P < 0.001). The relative
allele frequencies of the genotyped variants have been established. Genotype distribution for all investigated SNPs
was in Hardy-Weinberg equilibrium. We found a marginal association between glucose levels and genotypes at the
TCF7L2 locus (Mann-Whitney test P = 0.045) in females but not in males, with carriers of the T allele displaying
higher levels of blood glucose than homozygous for the A allele. This difference is also observed in males, although
not reaching significance. No association was found between glucose levels and the other genotyped variants. These
results suggest that the pathophysiology of the disease may be different between males and females, or that
environmental factors are influencing this trait in males. We are currently investigating the later hypothesis by
increasing our sample size and by analysing lifestyle information provided by the participants in order to evaluate
gene-environment interactions influencing glucose levels in the Portuguese population.The pilot study of the Portuguese Component of the European Health
Examination Survey (EHES) project has received funding from the European
Commission/DG Sanco (Agreement number: 20092301 – EHES JA – EAHC). This
study has also received funding from the Portuguese Foundation for Science
and Technology (FCT) (Project Reference: PTDC/SAU-ESA/101743/2008)
Prevalence of alpha-1 antitrypsin deficiency and hereditary hemochromatosis gene mutations in Algarve, Portugal
Alpha-1 antitrypsin (AAT) deficiency and hereditary hemochromatosis (HH) are two of the most fatal genetic disorders in adult life, affecting million individuals worldwide. They are often under-diagnosed conditions and diagnosis is only made when the patient is already in the advanced stages of damage. AAT deficiency results from mutations in one highly pleiomorphic gene located on chromosome 14, SERPINA 1, being Z and S mutations the most relevant clinically. These mutations will lead to an AAT deficit that compromises the lungs protection, originating emphysema, chronic bronchitis, asthma or even chronic obstructive pulmonary disease (COPD) and it is also strongly associated with various liver diseases. On the other hand, C282Y and H63D mutations in the HFE gene, located on chromosome 6, are reported to be mostly responsible for the iron accumulation in HH disorder, leading to severe damage in different organs. Disease manifestations include cirrhosis, hepatic fibrosis, diabetes mellitus, arthropathy and hepatocarcinoma.
Given the insufficient population-based information about the prevalence of these gene variants in the Portuguese population, the aim of this study was to assess their frequency in a representative sample from São Brás de Alportel, in the South of Portugal. To achieve our goal, we have genotyped a total of 208 adult subjects, including 118 females and 90 males (mean age: 58 years, range: 26-91). Regarding AAT deficiency, we found 4,3% MZ, 0,5% SS and 15,4% MS genotypes. The calculated frequency for the Z allele was 2,2% (95% CI: 0-11,7%) and for the S allele was 8,2% (95% CI: 0-17,4%). About HH, we found 1,4% C282Y/H63D, 2,4% H63D/H63D, 5,8% C282Y/N and 23,6% H63D/N genotypes. Frequencies of C282Y and H63D alleles were 3,6% (95% CI: 0-13%) and 14,9% (95% CI: 6-23,8%), respectively. The observed allele frequencies were in Hardy-Weinberg Equilibrium and no association was found with related diseases likely due to the smaller sample available.
Our findings show the highest prevalence of Z allele from SERPINA1 gene found, when compared to other populations. The remaining findings are in agreement with previously published studies. Future studies involving a larger sample size will be necessary to evaluate the penetrance of the studied gene mutations and to assess gene-environment interactions that influence disease risk, contributing to reduce the burden of these diseases which can have a great public health impact.The pilot study of the Portuguese Component of the European Health
Examination Survey (EHES) project has received funding from the European
Commission/DG Sanco (Agreement number: 20092301 – EHES JA – EAHC). This
study has also received funding from the Portuguese Foundation for Science
and Technology (FCT) (Project Reference: PTDC/SAU-ESA/101743/2008)
Genetic variation at the CY2C19 gene associated with Metabolic Syndrome susceptibility in a South Portuguese population
Metabolic syndrome (MetS) is a cluster of conditions — increased blood pressure, high blood glucose level, excess body fat around the waist and abnormal cholesterol levels — that occur together, increasing the risk of heart disease, stroke and diabetes. In Portugal, the MetS prevalence is estimated to be 27,5% with regional variations, being highest in the Alentejo (30,99%) and lowest in the Algarve (24,42%), constituting a public health problem.
Although for clinical settings, a binary definition of MetS enabling a yes or no diagnosis is useful, it is clear that dichotomizing a continuous outcome variable reduces the statistical power of the MetS association studies. Therefore, the aim of the present study is to identify genetic risk factors involved in MetS etiology, using a continuous MetS score. To achieve our goal, a principal component analysis was performed to compute a score using the six normalized risk factors for MetS (waist circumference, diastolic and systolic blood pressure, glucose, triglycerides and HDL blood levels), with a higher MetS score indicating a less favorable MetS profile. After calculating this score, an association study was performed using 37 SNPs in candidate genes involved in MetS related diseases. A total of 206 subjects, including 119 women and 87 men (mean age: 56,31± 16,37 years, range: 26-91 years) were included in this analysis. We found 4 SNPs significantly associated with higher MetS scores (rs4244285 (CYP2C19), rs279871 (GABRA2), rs1647 (NPY) and rs1142345(TPMT)). P-values are 4,36x10-4, 1,3x10-2, 1,7x10-2 and 9,76x10-3 respectively. After correcting for multiple testing only rs4244285 (CYP2C19) remains significant (p=0,016). In addition, we have performed a multiple regression analysis considering the CYP2C19 genotype as the independent variable, adjusted for age. The resulting model explains 17% of the MetS score variance. After adding the remaining SNP genotypes that do not survive the multiple testing correction, the same model is able to explain 23,1% of the score. Our findings support the evidence of an association between CYP2C19 rs4244285 gene polymorphism and the MetS score, emphasizing the importance of lipid metabolism, thought cytochrome P450 enzymes, in the MetS etiology. However, further studies will be necessary to replicate these findings in different populations as well as functional studies to clarify the role of this variant in the etiology of MetS.The pilot study of the Portuguese Component of the European Health
Examination Survey (EHES) project has received funding from the European
Commission/DG Sanco (Agreement number: 20092301 – EHES JA – EAHC). This
study has also received funding from the Portuguese Foundation for Science
and Technology (FCT) (Project Reference: PTDC/SAU-ESA/101743/2008)
On the Two Working Palettes of Almada Negreiros at DN Building in Lisbon (1939–1940): First Analytical Approach and Insight on the Use of Cd Based Pigments
This paper reports the first analytical approach carried out on two working palettes by
Portuguese modernist master Almada Negreiros, found in 1991 behind old wood cabinets at the
DN building in Lisbon. This is the only known occasion Almada left behind the color experiments
done before starting to paint in the nearby walls and as such, it is a unique opportunity to analyze
the materials and painting techniques that were originally used. The analytical setup comprised in
loco technical photography in Vis, UVF and NIR; p-OM, spectrophotometry in Vis and h-EDXRF,
complemented by OM-Vis, µ-FT-IR and VP-SEM-EDS of painting micro-samples and pigments in
powder form. Preliminary results suggested the use of fresco painting technique and revealed some
technical details, such as the use of a coarse lime sand finishing mortar mixed with natural vegetable
fibers, and the extensive use of cadmium-based pigments that were not commonly used (or even
recommended) in an alkaline environment. The Cd pigments were used alone or in mixtures with Fe
based pigments in the warm hues and with cobalt and ultramarine blue pigments in some green paint
layers. No clear evidence of organic materials that could have been used as binders was detecte
Facts related to the collection of biological samples in the National Health Examination Survey - Portuguese Component of the European Health Examination Survey
Abstrat disponível em: http://www.ichg2011.org/cgi-bin/showdetail.pl?absno=11013The objective of the National Health Examination Survey (NHES), which corresponds to the Portuguese
component of the European Health Examination Survey (EHES), is to collect health data, related risk factors
and biological samples of the Portuguese population, using the EHES recommended methodology. These
surveys involve an interview, clinical and physical measurements and blood collection. In this context, we
herein describe the pilot study performed in S. Brás de Alportel in the Algarve region. For this pilot study, we
have recruited 221 individuals (95 males and 126 females), between 25 and 91 years old, who were enrolled in
the Health Centre of S. Brás de Alportel (Algarve). For each participant, we have collected 16.5 ml of total
blood, in five different Vacutainer® tubes, which was later processed into serum, plasma and DNA. We have
performed several biochemical analyses(total cholesterol, LDL,HDL, glucose, tryglicerides, creatinine, ALT,
AST, -GT, CRP and iron) and a complete blood count. From the 221 participants in this pilot study, we were
able to collect blood to 219 (99.5%). To 185 of these (84.5%) we were able to collect the total amount of blood.
The biochemical analyses were performed in all the samples. The total blood count was performed in 103
samples (47%) due to transport constraints. We have also collected DNA from 210 participants (95.9%). We
have created a biobank comprising 1847 serum aliquots and 959 plasma aliquots, which have been stored at -
80°C and 210 DNA aliquots which have been stored at 4°C. In conclusion, during this study, we have
optimized the logistics and procedures to perform the large scale study for the NHES and EHES. In addition,
we have created a biobank comprising detailed questionnaire data, physical and clinical data and biological
samples from a representative sample of S. Brás de Alportel in Algarve, Portugal. This biobank will allow us to
perform future studies, including the determination of the prevalence of gene variants of public health interest,
the characterization of gene-environment interactions in the development of chronic diseases and the genetic
structure of the Portuguese population. The success rate, the quality of the data and of the biological samples
was high and comparable to similar studies.Fundação para a Ciência e Tecnologia e European Commission/DG Sanc
Corrosividade de sais de lítio para armazenamento de energia em centrais de concentração solar
RESUMO: O presente trabalho tem como objetivo estudar a corrosão de um aço inoxidável em contacto com um fluido de transferência de calor alternativo, para que possa ser utilizado como material estrutural no sistema de armazenamento de energia térmica numa central de energia solar de concentração (CSP). A atividade experimental envolveu a imersão do aço AISI 316L, em condições estáticas, numa mistura de sal ternário com Li2CO3-Na2CO3-K2CO3 (32,1; 33,4; 34,5 % m/m) durante 3000 h a 650 °C. A perda de massa ao longo do tempo de exposição é elevada com um aumento linear a partir das 120 horas de exposição. Através das técnicas SEM/EDS e DRX foi possível verificar a existência de várias camadas de óxidos com diferentes composições químicas, o que aliado ao aumento das suas espessuras ao longo do tempo, permitiu compreender os mecanismos de corrosão envolvidos. As amostras de sal retiradas ao longo do tempo foram caracterizadas por DSC e comparadas com a mistura pura de modo avaliar a sua estabilidade.info:eu-repo/semantics/publishedVersio
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