Source identification of uranium-containing materials at mine legacy sites in Portugal.

Whilst prior nuclear forensic studies have focused on identifying signatures to distinguish between different uranium deposit types, this paper focuses on providing a scientific basis for source identification of materials from different uranium mine sites within a single region, which can then be potentially used within nuclear forensics. A number of different tools, including gamma spectrometry, alpha spectrometry, mineralogy and major and minor elemental analysis, have been utilised to determine the provenance of uranium mineral samples collected at eight mine sites, located within three different uranium provinces, in Portugal. A radiation survey was initially conducted by foot and/or unmanned aerial vehicle at each site to assist sample collection. The results from each mine site were then compared to determine if individual mine sites could be distinguished based on characteristic elemental and isotopic signatures. Gamma and alpha spectrometry were used to differentiate between samples from different sites and also give an indication of past milling and mining activities. Ore samples from the different mine sites were found to be very similar in terms of gangue and uranium mineralogy. However, rarer minerals or specific impurity elements, such as calcium and copper, did permit some separation of the sites examined. In addition, classification rates using linear discriminant analysis were comparable to those in the literature.

Toxicidade subaguda do extrato etanólico das folhas de Myracrodruon urundeuva sobre o ciclo estral de ratas Wistar / Subacute toxicity of Myracrodruon urundeuva leave ethanolic extract and its effects on the estrous cycle of female Wistar rats

RESUMO A fitoterapia, abrangendo o uso popular e empírico de plantas medicinais no combate e prevenção de doenças, deve ser aliada a estudos científicos que comprovem a eficácia e segurança desses compostos. No Brasil, a ampla biodiversidade vegetal da região nordeste favorece o uso e estudo de plantas com potenciais terapêuticos. A Aroeira do Sertão (Myracrodruon urundeuva Allem.) é uma espécie pertencente à família Anacardiaceae, comum no semiárido, desde o Piauí até Minas Gerais. Seu uso é diverso e disseminado por todo o País, sendo indispensáveis estudos de suas potencialidades e riscos. Devido à ampla utilização da Myracrodruon Urundeuva de forma empírica, este trabalho tem por objetivo a pesquisa de efeitos tóxicos com doses repetidas do extrato etanólico de Myracrodruon urundeuva Allem. (EEMU) e sua influência no ciclo estral de ratas Wistar. No protocolo de toxicidade subaguda foram utilizadas 25 ratas Wistar, divididas em 5 grupos (n=5), tratadas com diferentes doses do EEMU (125, 250, 500 e 1000 mg/kg) e água destilada (controle) por um período de 28 dias. Nesse período foram realizadas mensurações do consumo de água e ração e avaliação comportamental. Esses animais foram avaliados diariamente quanto a fase do ciclo estral, por meio de esfregaço vaginal a fresco, sendo observada a frequência de cada fase bem como o intervalo interestro. As ratas foram anestesiadas e o sangue foi coletado para a realização dos ensaios bioquímicos. Em seguida, foram eutanasiadas para coleta e avaliação dos órgãos internos. Durante o período de avaliação, não foram observadas alterações de comportamento, nem de consumo de água ou ração. A evolução ponderal dos animais não diferiu entre os grupos tratados. A concentração sérica de ALT foi maior nos animais tratados com EEMU 1000 mg/kg. As ratas tratadas com o extrato não apresentaram alterações significativas na frequência das fases do ciclo estral bem como duração do estro e intervalo entre estros, quando comparadas ao grupo controle. Os resultados obtidos neste estudo não apontam alterações tóxicas significativas, sistêmicas ou sobre o ciclo estral, de ratas Wistar tratadas com o extrato, nas doses avaliadas, por um período de 28 dias.

ABSTRACT The herbal medicine, comprising the popular and empirical use of medicinal plants in combating and preventing diseases, should be combined with scientific studies that prove the effectiveness and safety of these compounds. In Brazil, the vast plant biodiversity of the Northeast favors the use and study of plants with therapeutic potential. Aroeira (Myracrodruon urundeuva Allem.) is a species of the Anacardiaceae family, common in the semiarid region, from Piauí to Minas Gerais. Its use is diverse and widespread throughout the country, making studies of its potential and risks necessary. Due to the wide use of Myracrodruon urundeuva in an empirical form, this paper aims to research toxic effects with repeated doses of Myracrodruon urundeuva Allem.ethanol extract (EEMU) and its influence on the estrous cycle of female Wistar rats. In a subacute toxicity protocol 35 female Wistar rats were used, divided into 5 groups (n=5) treated with different doses of EEMU (125, 250, 500 and 1000 mg/kg) and distilled water (control) for 28 days. In this period measurements of water intake, feed consumption were carried out and a behavioral assessment was performed. The estrous cycles of these animals were evaluated daily by fresh vaginal smear, it the frequency of each phase as well as the inter-estrus intervals were observed. The rats were anesthetized and blood was collected for the biochemical assays. Then they were euthanized for the collection and evaluation of internal organs. During the evaluation period, there were no observed behavioral changes nor were the water or food consumption variations. The weight gain of the animals did not differ between treatment groups. The serum ALT was higher in animals treated with EEMU 1000 mg/kg. The rats treated with the extract showed no significant changes in the frequency of the phases of the estrous cycle, estrus duration and estrus interval when compared to the control group. The results of this study do not indicate significant toxic alterations, neither systemic nor on the estrous cycle in female rats treated with the extract, at the evaluated doses, over a period of 28 days.

Toxicidade reprodutiva do extrato hidroalcóolico de Samanea tubulosa Benth em ratas wistar / Reproductive toxicity study in Wistar rats treated with hydroalcoholic extract of the pods of bordão-de-velho (Samanea tubulosa Benth)

RESUMOO objetivo deste trabalho foi avaliar possíveis efeitos do extrato das vargens de bordão-de-velho (Samanea tubulosa benth) sobre a reprodução em ratas Wistar. O extrato foi preparado a partir da secagem e trituração das vagens, seguida por maceração com etanol e, posteriormente, concentrado em rotavapor. Ratas Wistar gestantes foram tratadas com 75 mg.100 g-1 de peso corporal de extrato de S. tubulosa e o grupo controle recebeu 1ml/100 g-1 de peso corporal de solução salina por gavagem durante 19 dias. Após eutanásia no 20º dia, as seguintes variáveis foram analisadas: peso corporal fetal, peso dos fetos e placentas, número de corpos lúteos e de reabsorções, implantação, fetos vivos e mortos. O extrato de vagens de S. tubulosa apresenta toxicidade para o feto causando malformações, reabsorções fetais e diminuição pronunciada do peso ao nascer. Contudo, o extrato de vagens de S. tubulosanão influencia no número de corpos lúteos e número de implantações.

ABSTRACTThe aim of this study was to evaluate possible effects of pods from bordão-de-velho (Samanea tubulosa benth) extract on the reproduction of female rats.The extract was prepared by maceration wtith ethanol of dried and crushed pods, then it was concentrated in rotary evaporator. The pregnant Wistar rats were treated with a dose of 75 mg.100 g-1of body weight of Samanea tubulosa extract, by gavage , whereas the control group received 1ml.100g-1of saline by the same route for 19 days. After the euthanasia of the animals at day 20th,the following variables were analyzed: fetal body weight, weight of fetuses and placentas, number of corpora lutea, resorption points, live and dead fetuses and number of embryonic implantations. The extract from S. tubulosa pods, at the dose studied, showed toxicity causing fetal abnormalities, fetal resorption and pronounced decrease in the weight of offspring at birth. On the other hand, , the treatment with extract of S.tubulosa pods had no influence over corpora lutea and implantation numbers.

Ex vivo culturing of stromal cells with dexamethasone-loaded carboxymethylchitosan/poly(amidoamine) dendrimer nanoparticles promotes ectopic bone formation.

Recently, our group has proposed a combinatorial strategy in tissue engineering principles employing carboxymethylchitosan/poly(amidoamine) dendrimer nanoparticles (CMCht/PAMAM) towards the intracellular release and regimented supply of dexamethasone (Dex) aimed at controlling stem cell osteogenic differentiation in the absence of typical osteogenic inducers, in vivo. In this work, we have investigated if the Dex-loaded CMCht/PAMAM dendrimer nanoparticles could play a crucial role in the regulation of osteogenesis, in vivo. Macroporous hydroxyapatite (HA) scaffolds were seeded with rat bone marrow stromal cells (RBMSCs), whose cells were expanded in MEM medium supplemented with 0.01 mg ml(-1) Dex-loaded CMCht/PAMAM dendrimer nanoparticles and implanted subcutaneously on the back of rats for 2 and 4 weeks. HA porous ceramics without RBMSCs and RBMSCs/HA scaffold constructs seeded with cells expanded in the presence and absence of 10(-8) M Dex were used as controls. The effect of initial cell number seeded in the HA scaffolds on the bone-forming ability of the constructs was also investigated. Qualitative and quantitative new bone formation was evaluated in a non-destructive manner using micro-computed tomography analyses of the explants. Haematoxylin and Eosin stained implant sections were also used for the histomorphometrical analysis. Toluidine blue staining was carried out to investigate the synthesis of proteoglycan extracellular matrix. In addition, alkaline phosphatase and osteocalcin levels in the explants were also quantified, since these markers denote osteogenic differentiation. At 4 weeks post-implantation results have shown that the novel Dex-loaded carboxymethylchitosan/poly(amidoamine) dendrimer nanoparticles may be beneficial as an intracellular nanocarrier, supplying Dex in a regimented manner and promoting superior ectopic de novo bone formation.

Radioactivity in the environment around past radium and uranium mining sites of Portugal.

Measurements of ambient radiation doses and determination of radionuclide concentrations in mining waste and soils were performed in 60 areas of former radium and uranium mining. In several places, mining waste and low-grade uranium ore left on the surface contain radioactivity above regional background. Most of the former mining sites present no enhanced radionuclide concentrations. However, in the mining facilities where the radioactive ore was chemically extracted, mill tailings contain materials with elevated levels of radioactivity, up to 200 times the levels in unaffected soils of the region. Mud from neutralization ponds used to treat acid mine waters contains also elevated radionuclide concentrations. Furthermore, depending on the type of waste, the radioelement composition varies. Environmental rehabilitation measures shall take these differences into account in order to prevent in the long term the radioactive contamination of agriculture soils and water resources, and to ensure adequate radiological protection to the public and to the environment.

Role of acid attack in the in vitro bioactivity of a glass-ceramic of the 3CaO.P2O5-CaO.SiO2-CaO.MgO.2SiO2 system.

A non-bioactive glass-ceramic (GC13) that contains hydroxyapatite (Ca5(PO4)3OH), diopside (CaMg(SiO3)2) and althausite (Mg2 PO4OH) as crystalline phases has been obtained by thermal treatment of a parent bioactive glass (G13) of nominal composition (wt%) 40.0 CaO-34.5 SiO2-16.5 P2O5-8.5 MgO-0.5CaF2. To induce bioactivity, GC13 was chemically treated with 1 M HCl for different periods of time. After chemical etching the in vitro studies showed formation of an apatite-like surface layer. In this article the influence of etching time both on the surface composition of the glass-ceramic and on the growth rate of the apatite layer is studied. It is concluded that the presence of hydroxyapatite in the glass-ceramic, associated to microstructural fluctuations, can favour apatite deposition in vitro.

Metabolic fate of AMP, IMP, GMP and XMP in the cytosol of rat brain: an experimental and theoretical analysis.

A systematic study of the metabolic fate of AMP, IMP, GMP and XMP (NMP) in the presence of cytosol from rat brain is here presented; the kinetics of both disappearance of NMP, and appearance of their degradation products was followed by HPLC. In the absence of ATP, AMP was preferentially degraded to adenosine with concomitant appearance of inosine and hypoxanthine. In the presence of ATP, AMP was preferentially degraded via IMP. The nucleosides generated in the course of the reactions are further degraded, almost exclusively, via nucleoside phosphorylase using as cofactor the P(i) generated in the reaction mixture. In order to quantify the effect of each one of the enzymes involved in the degradation of NMP, two complementary approaches were followed: (i) the V:(max) and K:(m) values of the enzymes acting in the intermediate steps of the reactions were determined; (ii) these data were introduced into differential equations describing the concentration of the nucleotides and their degradation products as a function of the time of incubation. Factors affecting kinetic parameters of the equation velocity as a function of ATP concentration were introduced when required. The differential equations were solved with the help of Mathematica 3.0. The theoretical method can be used to simulate situations not feasible to be carried out, such as to measure the influence of nM-microM concentrations of ATP on the metabolism of AMP.

Surface modifications of a glass and a glass-ceramic of the MgO-3CaO.P2O5-SiO2 system in a simulated body fluid.

A glass of nominal composition (wt%) 17.25 MgO-52.75 3CaO.P2O5-30 SiO2 and a glass-ceramic obtained from it showed surface modifications when immersed in an acellular medium having a composition similar to that of human blood plasma. A (Ca, P)-rich layer, with an approximate Ca/P atomic ratio of 1.7, identified as hydroxyapatite, developed on both samples. The precipitated film on the glassy sample was weakly bonded, whereas that formed on the glass-ceramic was strongly adherent. The apatite precipitated during the in vitro tests on both samples grew as a needle-like structure with crystals about 150-200 nm long and 50-70 nm thick, as measured on specimens soaked for 1 month in the simulated body fluid (SBF). The presence of calcium and phosphate ions in the SBF contributed to the precipitation of the (Ca, P)-rich layers on both specimens.

Tempo de protrombina e velocidade de hemossedimentaçao: uma analise em funçao do tempo, da temperatura e do anticoagulante empregado / Protrombin time and erythrocite sedimentation rate: an analysis in function of time, temperature and anticoagulant employed

A literatura recomenda o uso do citrato de sodio e do Paul Heller como anticoagulantes ideais para a determinaçao do tempo de protrombina (PT) e velocidade de hemossedimentaçao (VHS), respectivamente. A finalidade do presente trabalho foi investigar as possiveis alteraçoes no PT em funçao do tempo e da temperatura e na VHS 60 min utilizando-se uma comparaçao entre os resultados apresentados. Foram colhidas amostras de sangue de 30 individuos, em citrato de sodio, em Paul Heller e em EDTA, tendo sido a primeira amostra empregada para a determinaçao do PT apos 1, 3, 5 e 8 horas e as duas outras para a execuçaoda tecnica de VHS. Os resultados observados no PT e na VHS, quando comparados entre si mediante a analise pelo X2 nao apresentaram diferenças significativas.