Electron spin resonance investigation of Mn^{2+} ions and their dynamics in manganese doped SrTiO_3

Using electron spin resonance, lattice position and dynamic properties of Mn2+ ions were studied in 0.5 and 2 % manganese doped SrTiO3 ceramics prepared by conventional mixed oxide method. The measurements showed that Mn2+ ions substitute preferably up to 97 % for Sr if the ceramics is prepared with a deficit of Sr ions. Motional narrowing of the Mn2+ ESR spectrum was observed when temperature increases from 120 K to 240-250 K that was explained as a manifestation of off-center position of this ion at the Sr site. From the analysis of the ESR spectra the activation energy Ea = 86 mV and frequency factor 1/?0 ? (2-10)x10^(-14) 1/s for jumping of the impurity between symmetrical off-center positions were determined. Both values are in agreement with those derived previously from dielectric relaxation. This proves the origin of dielectric anomalies in SrTiO3:Mn as those produced by the reorientation dynamics of Mn2+ dipoles.Comment: 16 pages, 6 figure

Adaptabilidade e estabilidade de linhagens de feijão-caupi de porte prostrado em Roraima.

Esse trabalho teve como objetivo avaliar um conjunto de 20 linhagens de feijão-caupi nas condições edafoclimáticas do estado de Roraima. O ensaio foi conduzido nos meses de julho a outubro, em três ambientes e dois ambientes, respectivamente, nos anos de 2010 e 2011 - 2012. O delineamento experimental adotado foi o de blocos casualizados completos com quatro repetições. Cada parcela foi constituida por quatro fileiras de 5 m de comprimento cada e espaçadas por 0,8 m entre elas, sendo a área útil as duas fileiras centrais. Os dados de produtividade de grãos (peso de grãos na área útil da parcela transformados para kg/ha) foram submetidos à análise de variância e as médias comparadas pelo teste de Scott-Knott a 5% de probabilidade. Posteriormente, as médias dos genótipos em cada ambiente foram submetidas a análise de adaptabilidade e estabilidade, de acordo com duas metodologias distintas. A linhagem 11 foi a mais produtiva em todos os ambientes considerados, porém apresentou coeficiente de regressão superior a unidade, sendo indicada apenas para ambientes com bom uso de tecnologia. A linhagem 13 foi a segunda mais produtiva dentre as linhagens experimentais, apresentando também ampla adaptabilidade por ambas as metrodologias utilizadas. A cultivar BRS Xiquexique foi a única cultivar comercial, juntamente com a linhagem 11, que esteve no grupo das mais produtivas em todos os ambientes avaliados.CONAC 2012. Disponível em: http://www.conac2012.org/resumos/pdf/163b.pdf. Acesso em: 31 jul. 2013

LPIN1 deficiency: A novel mutation associated with different phenotypes in the same family

Free PMC Article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5050266/Rhabdomyolysis (RM) is characterized by acute and often severe skeletal muscle damage resulting in myoglobinuria and, in severe cases, acute renal failure. In adults is typically due to trauma, intoxication or infection, whereas in children is frequently associated with inherited muscle disorders. LPIN1 mutations were identified as a cause of severe recurrent RM, which usually begin in childhood, and infections are the most frequent trigger.info:eu-repo/semantics/publishedVersio

Práticas e custo de implantação de Sistema de Integração Lavoura-Pecuária-Floresta em propriedade de médio pecuarista em região de floresta de transição de Roraima.

bitstream/item/41046/1/COT-56-2010-ID-84.pd

Contribution to the knowledge of the Cu–Sn–Zn system for compositions close to brass alloys

The effect of tin content in the equilibrium phases of the Cu–Zn-based alloys, within the range of chemical compositions with interest to brass producers is described. For this purpose, ternary alloys with copper contents between 55.4 and 67.5 wt.% and tin contents up to 5.30 wt.% have been studied. The chemical composition of each alloy has been determined by X-ray fluorescence spectrometry (XRF). Isothermal homogenization, followed by rapid cooling, has been employed to determine the equilibrium phases at different temperatures. The homogenized alloys have been observed by scanning electron microscopy and the respective chemical analysis of the phases determined by electron probe microanalysis (EPMA). The statistical analysis of the obtained results enable to correlate the chemical composition of equilibrium phases with temperature. The chemical composition of the three-phase field, for the studied temperatures, has also been determined

ACOX2 deficiency: A disorder of bile acid synthesis with transaminase elevation, liver fibrosis, ataxia, and cognitive impairment

Acyl CoA Oxidase 2 (ACOX2) encodes branched-chain acyl-CoA oxidase, a peroxisomal enzyme believed to be involved in the metabolism of branched-chain fatty acids and bile acid intermediates. Deficiency of this enzyme has not been described previously. We report an 8-y-old male with intermittently elevated transaminase levels, liver fibrosis, mild ataxia, and cognitive impairment. Exome sequencing revealed a previously unidentified homozygous premature termination mutation (p.Y69*) in ACOX2 Immunohistochemistry confirmed the absence of ACOX2 expression in the patient's liver, and biochemical analysis showed marked elevation of intermediate bile acids upstream of ACOX2. These findings define a potentially treatable inborn error of bile acid biosynthesis caused by ACOX2 deficiency