Fabrication and Electrical Characterization of Translucent Bi 12

The production of high-density Bi12TiO20 ceramics, their transmission spectrum, and impedance features are reported. The samples were synthesized at 700°C/6 h and sintered at 800°C/3 h. This procedure yielded translucent ceramics with relative density of 99.2±0.5% and average grain size of 3.1±1.6 μm. Samples with 0.5 mm thickness were translucent with optical transmission of about 30% at 800 nm. The electrical and dielectric properties of the high-density ceramics were studied and compared with those measured for samples with lower density and also with the literature about Bi12TiO20 single crystals. The activation energy for the conduction process in high-density ceramic was 0.99 eV, and the dielectric permittivity was 40 at 200°C. These values are comparable to those reported for single crystals

Efeito da aplicação de composto de lixo urbano na acumulação de nitrato pela cenoura (Daucus carota, L.).

Portanto, o objetivo do presente trabalho foi o de determinar até que ponto o uso agrícola do composto de lixo pode ser limitado por problemas de exposição da população pela ingestão de alimentos com níveis de nitrato acima do tolerável.bitstream/CNPS/11595/1/comtec20_2003_lixo-urbano_cenoura.pd

Ocorrência de horizontes antrópicos (Terra Preta de Índio) em Neossolos Quartzarênicos no município de Parintins - AM - Brasil.

Este trabalho teve por objetivo caracterizar três perfis com horizonte antrópico na localidade conhecida como comunidade do Lago da Valeria, no município de Parintins - AM

Kinetic description of particle interaction with a gravitational wave

The interaction of charged particles, moving in a uniform magnetic field, with a plane-polarized gravitational wave is considered using the Fokker-Planck- Kolmogorov (FPK) approach. By using a stochasticity criterion, we determine the exact locations in phase space, where resonance overlapping occurs. We investigate the diffusion of orbits around each primary resonance of order (m) by deriving general analytical expressions for an effective diffusion coeficient. A solution to the corresponding diffusion equation (Fokker-Planck equation) for the static case is found. Numerical integration of the full equations of motion and subsequent calculation of the diffusion coefficient verifies the analytical results.Comment: LaTeX file, 15 page

Molecular fingerprints for a novel enzyme family in actinobacteria with glucosamine kinase activity

Actinobacteria have long been the main source of antibiotics, secondary metabolites with tightly controlled biosynthesis by environmental and physiological factors. Phosphorylation of exogenous glucosamine has been suggested as a mechanism for incorporation of this extracellular material into secondary metabolite biosynthesis, but experimental evidence of specific glucosamine kinases in Actinobacteria is lacking. Here, we present the molecular fingerprints for the identification of a unique family of actinobacterial glucosamine kinases. Structural and biochemical studies on a distinctive kinase from the soil bacterium Streptacidiphilus jiangxiensis unveiled its preference for glucosamine and provided structural evidence of a phosphoryl transfer to this substrate. Conservation of glucosamine-contacting residues across a large number of uncharacterized actinobacterial proteins unveiled a specific glucosamine binding sequence motif. This family of kinases and their genetic context may represent the missing link for the incorporation of environmental glucosamine into the antibiotic biosynthesis pathways in Actinobacteria and can be explored to enhance antibiotic production. IMPORTANCE The discovery of novel enzymes involved in antibiotic biosynthesis pathways is currently a topic of utmost importance. The high levels of antibiotic resistance detected worldwide threaten our ability to combat infections and other 20th-century medical achievements, namely, organ transplantation or cancer chemotherapy. We have identified and characterized a unique family of enzymes capable of phosphorylating glucosamine to glucosamine-6-phosphate, a crucial molecule directly involved in the activation of antibiotic production pathways in Actinobacteria, nature’s main source of antimicrobials. The consensus sequence identified for these glucosamine kinases will help establish a molecular fingerprint to reveal yet-uncharacterized sequences in antibiotic producers, which should have an important impact in biotechnological and biomedical applications, including the enhancement and optimization of antibiotic production.We acknowledge the European Synchrotron Radiation Facility (Grenoble, France) for provision of synchrotron radiation facilities and thank their staff for help with data collection. Part of these experiments were performed at beamline BL13-XALOC of ALBA Synchrotron (Cerdanyola del Vallès, Spain), with the collaboration of ALBA staff and CALIPSOplus (grant 730872) funding. The support of the X-ray Crystallography Scientific Platform of i3S (Porto, Portugal) is also acknowledged. We thank Pedro Lamosa from CERMAX, ITQB-NOVA (Oeiras, Portugal), for acquiring and interpreting the NMR data. This work was supported by the Structured Program on Bioengineered Therapies for Infectious Diseases and Tissue Regeneration (Norte-01-0145-FEDER-‏000‏012), funded by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through Fundo Europeu de Desenvolvimento Regional (FEDER) and by FEDER through the COMPETE 2020-Operational Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT-Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of project Institute for Research and Innovation in Health Sciences (POCI-01-0145-FEDER-007274) and also by grants UID/NEU/04539/2019 and POCI-01-0145-FEDER-029221. D.N.-C. acknowledges the European Regional Development Fund (CENTRO-01-0145-FEDER-000012-ealthyAging2020) for a research fellowship and FCT for Ph‏D f‏ellowship SFRH/BD/117777/2016

Fortalecimento da ovinocultura de corte no Município de Dormentes, Alto Sertão de Pernambuco.

Publicado também na Revista Brasileira de Agroecologia, v. 4, n. 2, 2009

Role of crotoxin, a phospholipase A2 isolated from Crotalus durissus terrificus snake venom, on inflammatory and immune reactions.

BACKGROUND: Crotoxin (CTX) is a potent neurotoxin from Crotalus durissus terrificus snake venom (CdtV) composed of two subunits: one without catalytic activity (crotapotin), and a basic phospolipase A2. Recent data have demonstrated that CdtV or CTX inhibit some immune and inflammatory reactions. AIM: The aim of this paper was to investigate the mechanisms involved in these impaired responses. MATERIALS AND METHODS: Male Swiss mice were bled before and at different intervals of time after subcutaneous injection of CTX or bovine serum albumin (BSA) (control animals). The effect of treatments on circulating leukocyte mobilisation and on serum levels of interleukin (IL)-6, IL-10, interferon (IFN)-gamma and corticosterone were investigated. Spleen cells from treated animals were also stimulated in vitro with concanavalin A to evaluate the profile of IL-4, IL-6, IL-10 or IFN-gamma secretion. Cytokine levels were determined by immunoenzymatic assay and corticosterone levels by radioimmunoassay. To investigate the participation of endogenous corticosteroid on the effects evoked by CTX, animals were treated with metyrapone, an inhibitor of glucocorticoid synthesis, previous to CTX treatment. RESULTS: Marked alterations on peripheral leukocyte distribution, characterised by a drop in the number of lymphocytes and monocytes and an increase in the number of neutrophils, were observed after CTX injection. No such alteration was observed in BSA-treated animals. Increased levels of IL-6, IL-10 and corticosterone were also detected in CTX-injected animals. IFN-gamma levels were not modified after treatments. In contrast, spleen cells obtained from CTX-treated animals and stimulated with concanavalin A secreted less IL-10 and IL-4 in comparison with cells obtained from control animals. Metyrapone pretreatment was effective only to reverse the neutrophilia observed after CTX administration. CONCLUSIONS: Our results suggest that CTX may contribute to the deficient inflammatory and immune responses induced by crude CdtV. CTX induces endogenous mechanisms that are responsible, at least in part, for these impaired responses

Right subclavian artery evaluation during first trimester ultrasound scan

OBJETIVO: Avaliar a artéria subclávia direita durante a ecografia do primeiro trimestre, descrever a técnica para a sua avaliação e, em caso de identificação de artéria subclávia direita aberrante (ARSA), determinar sua associação com alterações cromossómicas e/ou malformações cardíacas e sua orientação.MÉTODOS: Estudo prospectivo que consistiu na avaliação da artéria subclávia direita no primeiro trimestre (comprimento crânio caudal entre 45 e 84 milímetros), em todas as gestações únicas, consecutivas, por um único examinador, ecógrafo Voluson E8 (GE Healthcare, Zipf, Áustria) com sonda transabdominal RAB 4-8-D, 2 a 8 MHz, por um período não superior a 2 minutos, numa população geral de baixo risco. Com a ajuda do power/color Doppler, a artéria subclávia direita foi classificada como normal ou aberrante. Foi utilizada análise de regressão estatística (IBM SPSS Statistics for Windows, versão 20.0) para estudar o grau de associação entre a falha na avaliação/classificação da artéria subclávia direita e o comprimento crânio-caudal fetal e o índice de massa corporal materno.RESULTADOS: A mediana da idade materna foi de 30 anos (variando entre 17 e 43 anos) e a mediana do tempo de gestação no momento da avaliação da artéria subclávia direita foi de 12 semanas de gestação (variando entre 11 e 13 semanas de gestação). A avaliação da artéria subclávia direita foi possível em 138/176 (78,4%) dos casos. ARSA foi diagnosticada em um único caso (0,7%). Esse feto com ARSA também apresentou um foco hiperecogênico no ventrículo cardíaco esquerdo. Foi realizada ecocardiografia fetal às 16 semanas de gestação, que confirmou o diagnóstico de ARSA e foco hiperecogênico. A amniocentese revelou cariótipo normal, 46, XX.CONCLUSÃO: É possível fazer o diagnóstico de ARSA na ecografia do primeiro trimestre. O nosso único caso de ARSA apresentou um cariótipo normal sem malformações cardíacas associadas

Empresas desenvolvedoras de software para o agronegócio: um retrato preliminar.

Este trabalho tem por objetivo apresentar um retrato parcial das empresas desenvolvedoras de software para o agronegócio, no Brasil, no que tange à distribuição geográfica e às barreiras de inserção no mercado. A metodologia contou com duas etapas: a elaboração de um questionário semi-estruturado para entrevistar as empresas e a criação de um banco de dados online para armazenar e gerar relatórios dos dados levantados. As conclusões apontam uma concentração geográfica nas regiões sudeste e sul e, como principais barreiras ao ingresso no mercado, a falta de mão-de-obra qualificada e desconhecimento de mercado.SBIAgro 2009