The study of natural and artificial radionuclides incorporation in teeth and head bones of animals lived nearby Caetité uranium mine, Brazil

This study aimed at assessing the incorporation of radionuclides in animals in the proximity of the uranium mine in Caetité, Brazil. In 2014, samples of bovine and equine teeth and skull bones were collected and their contents of natural and artificial isotopes were assessed using nuclear spectrometry techniques. Gamma ray emission from ^226,228Ra and ⁴⁰K isotopes was determined using high-purity germanium (HPGe) spectrometry, ⁹⁰Sr radioactivity was measured with liquid scintillation, and ^234,238U, ^232,230,228Th, ²¹⁰Po and ^239+240Pu radioactivity was assessed with alpha-spectrometry. Prior to the measurements, sample dissolutions and isotope separations were performed. Our results indicate a high ²²⁸Th isotope content in the skull bones and the teeth of animals, up to 179 Bq per kg of ash. The ²²⁶Ra and ²²⁸Ra concentrations were slightly lower. Activity concentrations of other isotopes were significantly lower or below the detection limit. We could not identify sources of technologically enhanced levels of ²²⁸Ra in the area we investigated; therefore we suggest that their origin is natural.

Correlação entre digestibilidade dos nutrientes e o comportamento ingestivo de novilhos em pastejo

Objetivou-se com esse estudo avaliar as correlações existentes entre o consumo de nutrientes e o comportamento ingestivo de novilhos mestiços ½ Holandês x Zebu na fase de recria em pastagem de Brachiaria brizantha "Marandu", no período das águas. Foram utilizados 22 novilhos com média de sete meses de idade e peso corporal médio inicial de 164,09±12,13 kg, distribuídos em delineamento inteiramente casualizado, com dois tipos de suplemento e onze repetições por tipo de suplementação e manejados em pastejo rotacionado numa área de 6,5 ha. Efetuou-se a análise de correlação linear de Pearson entre as variáveis comportamentais estudadas e os coeficientes de digestibilidade dos nutrientes encontrados. Os coeficientes de correlação foram testados por meio do teste t. O tempo de ruminação apresentou correlação positiva com o coeficiente de digestibilidade dos nutrientes. O tempo de alimentação no cocho correlacionou positivamente com o coeficiente de digestibilidade da matéria seca (MS), matéria orgânica (MO), proteína bruta (PB) e extrato etéreo (EE). Correlação positiva foi observada entre o tempo de mastigação total e o coeficiente de digestibilidade dos nutrientes. O número de períodos de ócio e ruminação apresentaram correlações positivas com o coeficiente de digestibilidade dos nutrientes e o numero de períodos de alimentação no cocho correlacionou positivamente com o coeficiente de digestibilidade da PB. A taxa de bocados e o número de bocados por dia correlacionaram-se positivamente com o coeficiente de digestibilidade dos nutrientes. Correlação positiva foi observada entre o número de mastigações merícicas por dia e o coeficiente de digestibilidade da MS, MO e carboidratos totais (CT). Correlações positivas foram observadas entre as eficiências de alimentação e ruminação da matéria seca e da fibra em detergente neutro com o coeficiente de digestibilidade dos nutrientes estudados. A digestibilidade dos nutrientes exerce influência direta sobre as expressões comportamentais apresentadas pelos animais estudados.

LevRad software as a tool to learn how to proceed with an evaluation of barriers

We developed the software LevRad with the objective of teaching how to proceed in an analysis of barriers shielding against x-rays to minimize the contact of the professional or the student with x-rays and also to prevent wearing out of the x-ray equipment. Some tests of the software were made, and preliminary results indicate that LevRad is efficient as a complementary tool for the development of professionals related to diagnostic radiology. In the case of education, an advantage is gained when the beginner uses the software before his or her first contact with x-ray equipment in locu. The software introduces a basic knowledge about evaluation of barriers, prevents wearing out of the x—ray tube, reinforces teaching of evaluation of barriers, and reduces the collective effective dose by avoiding unnecessary exposures when possible.

Quantitative and qualitative interferences of pentoxifillyne on hepatic Schistosoma mansoni granulomas: effects on extracellular matrix and eosinophil population

Mast cells and eosinophils actively participate in tissue repair and are prominent components of Schistosoma mansoni granulomas. Since pentoxifillyne (PTX) is an immunomodulatory and antifibrotic substance, we aimed to characterize, by morphological techniques, the effect of this drug on fibrosis developed inside murine hepatic schistosomal granulomatous reaction, beyond the quantification of eosinophil and mast cell populations. The drug (1 mg/100 g animal weight) was administrated from 35 to 90 days post-infection, when the animals were killed. The intragranulomatous interstitial collagen network was analyzed by confocal laser scanning microscopy, the number of eosinophils and mast cells was quantified and the results were validated by t-student test. Treatment did not interfere on the granuloma evolution but caused a significant decrease in the total and involutive number of hepatic granulomas (p = 0.01 and 0.001, respectively), and in the intragranulomatous accumulation of eosinophils (p = 0.0001). Otherwise, the number of mast cells was not significantly altered (p = 0.9); however, it was positively correlated with the number of granulomatous structures (r = 0.955). In conclusion, PTX does not affect development and collagen deposition in S. mansoni murine granuloma, but decreases the intragranulomatous eosinophil accumulation possibly due to its immunomodulatory capability, interfering in cellular recruitment and/or differentiation.

TL, EPR and optical absorption studies on natural alexandrite compared to natural chrysoberyl

The TL, optical absorption (OA) and EPR properties of natural Brazilian alexandrite and chrysoberyl have been investigated. The TL measurements for natural alexandrite show five peaks between 100 and 450 degrees C, with their emission spectrum having 370 and/or 570 nm components. The intensity of the 320 degrees C TL peak was found to be enhanced with pre-annealing treatment, more prominently above 600 degrees C. The OA and EPR measurements showed that this kind of heat treatment induces the Fe2+ --> Fe3+ conversion in the natural sample. Chrysoberyl samples exhibited the TL peaks at the same temperatures as alexandrite samples, but the glow curves were more than 200 times less intense than alexandrite ones.

Experimental infection of newborn mice with murine EDIM rotavirus

All four-day old Swiss mice whose dams were seronegative to rotavirus developed diarrhea 72 h after oral infection with EDIM rotavirus (HP strain). Electron microscopy of infected small intestine showed rotavirus particles of different sizes and morphology in the intestinal absorptive cells. In these cells rotavirus particles of 30 to 60 nm representing the various steps of virus maturation were visualized in viroplasm near the rough endoplasmic reticulum (RER). Mature rotavirus particles of 70 nm approximately were observed inside the RER of the intestinal absorptive cells. In the lamina propria rotavirus particles of approximately 30 nm and tubules were observed in phagosome-like structures of subepithelial phagocytes and were probably destroyed by lysosomal enzymes. The absence of signs of viral replication in phagocytes of lamina propria suggests that this may be the mechanism for viral antigen presentation to the host immunological system and may be one of the reasons for the fact that rotavirus infection is limited to the intestine.