Chrysotile within calcite veins from Northern Apennines

In the Northern Apennines several olistoliths made up of serpentinites, calpionelle limestones and ophiolitic breccias have been recognized within the Porcellara Complex, Monte Cassio Unit. These olistoliths are frequently crossed by a dense network of centimeter to decimeter veins generally filled by carbonate minerals (e.g. La Costa, Berceto, PR). Morphological and compositional data (SEM-EDS and XRPD) have revealed that these carbonate minerals consist mainly of well-formed, white to milky calcite crystals, strictly associated with chrysotile. This mineral is found as white thin fibers (< 1 micron), grew up in intimate association with calcite crystals. These fibers may be very rare and randomly scattered within the crystals of calcite, or can be grouped into bundles of millimeter to centimeter size. At times, the chrysotile can get to completely fill the vein. Chrysotile fibers are well-formed and euhedral at all scales from hand specimen to electron microscope images. In some cases, individual fibers of chrysotile are not visible in hand specimen or under the petrographic microscope; however, SEM images show the characteristic elongate crystal morphology. The fibers are also characteristically curved at the millimeter scale. It is important to note that the fibers of chrysotile appear, frequently, as a physical extension of calcite crystals, without any evident morphological discontinuity in the transition from a massive (calcite) to a fibrous (chrysotile) appearence. The results of detailed SEM-EDS elemental analyses carried out in various segments of the contact areas between calcite and chrysotile crystals seem to show a gradual transition in chemical composition from pure calcite to pure chrysotile phases, passing through various intermediate arrangements

Prismatic to asbestiform offretite from Northern Italy. Occurrence, morphology and crystal-chemistry of a new potentially hazardous zeolite

A multi-methodological approach, based upon field investigation, morphological characterization, chemical analysis and structure refinement was applied to different samples of fibrous offretite, a new potentially hazardous zeolite recently discovered in northern Italy. Their morphology ranges from stocky-prismatic to asbestiform. All the investigated fibers may be considered as "inhalable", and they are well within the range of the "more carcinogenic fibers" regarding diameter. As regards the length, the main mode observed in the asbestiform samples is 20-25 mu m, and similar to 93% of the measured fibers are >5 mu m and may be significantly associated with carcinogenesis also in terms of lengths. The chemical-structural features of the investigated fibers are comparable: the extra-framework cations K+, Mg2+ and Ca2+ are present in all samples in similar proportions, and refined cell parameters are similar among the samples. Offretite occurs in 60% of the investigated sites, with an estimated amount up to 75 vol % of the associated minerals. The presence of this mineral could be of concern for risk to human health, especially if one considers the vast number of quarries and mining-related activities that are operating in the zeolite host rocks

The Obelisk of Pelotas and its Iconographic Analisis

In the city of Pelotas, in the state of Rio Grande do Sul, in the Areal district, there is a monument erecter during the nineteenth century in favor of the republican ideal. The Republican Obelisk – or Obelisk Domingos José de Almeida or Republican Monument – was inaugurated April 7, 1885 honoring Domingos José de Almeida, a politician and investor who resided in Pelotas, and the Riograndense Republic, which existed during the Ragamuffin War (1835 – 1845). This column is the only republican monument erected in Brazil during the monarchial government. The aim of this paper is analyze the elements present in its structure – symbols, dates, location, format and plates – to interpret what message it’s creators sought to show about Domingos de Almeida and the republicanism.Na cidade de Pelotas, no estado do Rio Grande do Sul, no bairro Areal, há um monumento erguido no século XIX em prol do ideal republicano. O Obelisco Republicano - ou Obelisco Domingos José de Almeida ou Monumento Republicano – foi inaugurado em 7 de Abril de 1885, homenageando Domingos José de Almeida, político e investidor que residiu em Pelotas, e a República Rio-Grandense, que existiu durante a Guerra dos Farrapos (1835-1845).  Essa coluna é o único monumento de cunho republicano erguido no Brasil durante o governo monárquico. O objetivo desse artigo é analisar os elementos presentes em sua estrutura – símbolos, datas, localização, formato e placas – para interpretar que mensagem dos idealizadores do monumento buscavam mostrar a respeito de Domingos de Almeida e o republicanismo

Neutron activation analysis of the 30Si content of highly enriched 28Si: proof of concept and estimation of the achievable uncertainty

We investigated the use of neutron activation to estimate the 30Si mole fraction of the ultra-pure silicon material highly enriched in 28Si for the measurement of the Avogadro constant. Specifically, we developed a relative method based on Instrumental Neutron Activation Analysis and using a natural-Si sample as a standard. To evaluate the achievable uncertainty, we irradiated a 6 g sample of a natural-Si material and modeled experimentally the signal that would be produced by a sample of the 28Si-enriched material of similar mass and subjected to the same measurement conditions. The extrapolation of the expected uncertainty from the experimental data indicates that a measurement of the 30Si mole fraction of the 28Si-enriched material might reach a 4% relative combined standard uncertainty

Alpha1-antitrypsin deficiency and cardiovascular disease: questions and issues of a debated relation

Alpha1-antitrypsin (AAT) is one of the major inhibitors involved in protease/antiprotease homeostasis, and it is mainly produced by hepatocytes and pulmonary epithelial cells. Its deficiency, called alpha1-antitrypsin deficit (AATD), leads to severe hepatic and respiratory issues. Also, AAT is released into the bloodstream providing systemic anti-inflammatory effects. Apart from acting as an acute-phase anti-inflammatory protein, it can be a biomarker for monitoring disease evolution. A reduced or defective production leads to a loss of anti-inflammatory function, protease-antiprotease imbalance and cellular engorgement due to polymers deposition, with system-wide repercussions. This review aims to evaluate AATD condition in the major vessels of the head and neck, thoracic and abdominal districts. Also, a dedicated focus on autoimmune vascular diseases will be provided. A critical revision of the main literature findings starting from the 1980s until now has been performed. Studies conducted over the years have provided several contradictory pieces of evidence. Most authors acknowledge the protective and anti-inflammatory AAT role on the vascular endothelium. However, correlations between AATD and major arteries, cerebral and cardiovascular conditions, and autoimmune diseases remain unclear. Most studies recognize the role of AATD in vascular diseases but only as a cofactor inducing cellular and tissue structure impairments. However, this condition alone is not enough to determine new disease onset. Due to the opposing results reported over the years, there is still a considerable lack of knowledge on the role covered by AATD in vascular diseases. A renewed interest in this research field should be encouraged to grant new solid evidence and validate the putative role of AATD screening and replacement therapy as useful diagnostic and treatment tools

AS DUAS FACES DE UMA MESMA REPÚBLICA: O OBELISCO A DOMINGOS JOSÉ DE ALMEIDA - PELOTAS E O MONUMENTO A JÚLIO DE CASTILHOS - PORTO ALEGRE

RESUMOO presente texto é composto por uma breve análise do obelisco republicano erguido a Domingos José de Almeida na cidade de Pelotas, em 1885 e do monumento/obelisco erguido em homenagem a Júlio de Castilhos, na cidade de Porto Alegre, em 1913. Os dois indivíduos homenageados por esses monumentos foram políticos que defendiam o republicanismo no século XIX que atuaram em momentos diferentes - um na primeira metade do século e outro em sua segunda metade -, o que resultou em estruturas estéticas diferentes para os dois obeliscos. Neste artigo, demostra-se como ambos os obeliscos, construídos em situações históricas diferentes, remontam às origens republicanas da Revolução Farroupilha.ABSTRACTThe present text consists of a brief analysis of the republican obelisk erected to Domingos José de Almeida in the city of Pelotas in 1885 and the monument/obelisk erected in honor of Júlio de Castilhos, in the city of Porto Alegre, in 1913. The two individuals who were honored by these monuments were politicians who advocated republicanism in the nineteenth century and acted at different times - one in the first half of the century and another in its second half - resulting in different aesthetic structures for the two obelisks. In this article, it is shown how both obelisks, built in different historical situations, date back to the republican origins of the Farroupilha Revolution

AS DUAS FACES DE UMA MESMA REPÚBLICA: O OBELISCO A DOMINGOS JOSÉ DE ALMEIDA - PELOTAS E O MONUMENTO A JÚLIO DE CASTILHOS - PORTO ALEGRE

RESUMOO presente texto é composto por uma breve análise do obelisco republicano erguido a Domingos José de Almeida na cidade de Pelotas, em 1885 e do monumento/obelisco erguido em homenagem a Júlio de Castilhos, na cidade de Porto Alegre, em 1913. Os dois indivíduos homenageados por esses monumentos foram políticos que defendiam o republicanismo no século XIX que atuaram em momentos diferentes - um na primeira metade do século e outro em sua segunda metade -, o que resultou em estruturas estéticas diferentes para os dois obeliscos. Neste artigo, demostra-se como ambos os obeliscos, construídos em situações históricas diferentes, remontam às origens republicanas da Revolução Farroupilha.ABSTRACTThe present text consists of a brief analysis of the republican obelisk erected to Domingos José de Almeida in the city of Pelotas in 1885 and the monument/obelisk erected in honor of Júlio de Castilhos, in the city of Porto Alegre, in 1913. The two individuals who were honored by these monuments were politicians who advocated republicanism in the nineteenth century and acted at different times - one in the first half of the century and another in its second half - resulting in different aesthetic structures for the two obelisks. In this article, it is shown how both obelisks, built in different historical situations, date back to the republican origins of the Farroupilha Revolution

Prismatic to asbestiform offretite from Northern Italy. Occurrence, morphology and crystal-chemistry of a new potentially hazardous zeolite

A multi-methodological approach, based upon field investigation, morphological characterization, chemical analysis and structure refinement was applied to different samples of fibrous offretite, a new potentially hazardous zeolite recently discovered in northern Italy. Their morphology ranges from stocky-prismatic to asbestiform. All the investigated fibers may be considered as "inhalable", and they are well within the range of the "more carcinogenic fibers" regarding diameter. As regards the length, the main mode observed in the asbestiform samples is 20-25 mu m, and similar to 93% of the measured fibers are >5 mu m and may be significantly associated with carcinogenesis also in terms of lengths. The chemical-structural features of the investigated fibers are comparable: the extra-framework cations K+, Mg2+ and Ca2+ are present in all samples in similar proportions, and refined cell parameters are similar among the samples. Offretite occurs in 60% of the investigated sites, with an estimated amount up to 75 vol % of the associated minerals. The presence of this mineral could be of concern for risk to human health, especially if one considers the vast number of quarries and mining-related activities that are operating in the zeolite host rocks