63 research outputs found
Analytical characterisation and pathology
Sem PDF.The aim of this work was to determine the physico-chemical characteristics of the stained-glass windows into the 19th century of two mausoleums located in the city of Belém do Parå (Brazil), and to evaluate their state of conservation. The glass chemical composition was determined by WXRF and SEM/EDS. The samples' morphology and the microorganisms' identification were carried out by optical microscopy. The results indicated that the samples were soda-lime silicate glass, with approximately 70wt. % of SiO2, which contributed to the resistance of the stained glass to the weathering. The concentration of Na2O was normally twice the K2O, which contrasts with the composition of other panels produced during the same period, as reported in the literature. The biofilm is composed by cyanobacteria and rotifers. Overall, the panels analysed were in a good state of conservation, despite their exposure to tropical climate conditions for more than a century with no preventive measures whatsoever.publishersversionpublishe
Familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC): Compound heterozygous mutation in the claudin 16 (CLDN16) gene
<p>Abstract</p> <p>Background</p> <p>Familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC) is an autosomal recessive disorder of renal calcium and magnesium wasting frequently complicated by progressive chronic renal failure in childhood or adolescence.</p> <p>Methods</p> <p>A 7 year old boy was investigated following the findings of marked renal insufficiency and nephrocalcinosis in his 18-month old sister. He too was found to have extensive nephrocalcinosis with increased fractional excretion of magnesium: 12.4% (<4%) and hypercalciuria: 5.7 mmol (< 2.5/24 hours). He had renal impairment, partial distal renal tubular acidosis and defective urinary concentrating ability. Therapy with thiazide diuretics and magnesium supplements failed to halt the progression of the disorder. Both children subsequently underwent renal transplantation. Both children's parents are unaffected and there is one unaffected sibling.</p> <p>Results</p> <p>Mutation analysis revealed 2 heterozygous mutations in the claudin 16 gene <it>(CLDN16</it>) in both affected siblings; one missense mutation in exon 4: C646T which results in an amino acid change Arg216Cys in the second extracellular loop of <it>CLDN16 </it>and loss of function of the protein and a donor splice site mutation which changes intron 4 consensus splice site from 'GT' to 'TT' resulting in decreased splice efficiency and the formation of a truncated protein with loss of 64 amino acids in the second extracellular loop.</p> <p>Conclusion</p> <p>The mutations in <it>CLDN16 </it>in this kindred affect the second extra-cellular loop of claudin 16. The clinical course and molecular findings suggest complete loss of function of the protein in the 2 affected cases and highlight the case for molecular diagnosis in individuals with FHHNC.</p
The mineralogy and chemistry of the German and Portuguese tiles used to face a historic building in the Amazon region and their natural susceptibility to tropical weathering
Da 'abominĂĄvel profissĂŁo de vampiros': EmĂlio Goeldi e Os mosquitos no ParĂĄ (1905)
Severe hypoalphalipoproteinaemia in a child with acute post-streptococcal glomerulonephritis (APSGN)
The historical glazed tiles from Nossa Senhora da Soledade Cemetery, Northern Brazil: microstructural, physical and mineralogical characterization
Abstract During the nineteenth century, historical glazed tiles were used in the mortuary architecture of Nossa Senhora da Soledade Cemetery, in Belém. These ceramic pieces are an extraordinary part of Brazilian cultural heritage but are at a high deterioration stage due to conditions to which they are subjected. The aim of this research was the microstructural, physical and mineralogical characterization of glazed tiles from Nossa Senhora da Soledade Cemetery. The samples consisted of Portuguese fragments from the nineteenth century, decorated by stamping. The characterization was performed by optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, water absorption test, and X-ray diffractometry. The results indicated that glazed and ceramic layers have manufacturing defects and a heterogeneous character due to the handmade production process. The porosities vary from 13.3% to 22.9%. The ceramics are composed of quartz, gehlenite, calcite, rutile, cristobalite, diopside, anorthite, hematite and wollastonite. According to the results, despite many similarities (country of origin, century of production, decorative technique), the samples have variations in their microstructure and mineralogy. Information regarding the compositions of the tiles and their variation is important to support future restorative interventions
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