Eurashe - Conferência do 10º Aniversário "Pan Metro Ariston"

Foi nos passados dias 26 e 27 de Maio, em Chania (Creta, Grécia), no âmbito da 10ª Conferência da Eurashe (European Association for Higher Education – uma associação europeia de instituições de ensino superior não universitário), que tive o prazer de, pela primeira vez, ouvir Sócrates Kaplanis, uma figura sui generis, de quem tinha já ouvido falar por diversas vezes, conhecida pela sua saudável irreverência e perturbante personalidade. Professor no Technological Educational Institute de Patras (Grécia), e membro fundador da Eurashe, Sócrates tem sido uma presença constante nas conferências anuais desta Associação e um elemento indispensável no reavivamento dos ensinamentos clássicos (ao mesmo tempo tão contemporâneos), não fosse ele um verdadeiro grego, até mesmo de semblante. Assim, só poderia ter iniciado a sua intervenção (tarde mas não tardia) com alguns diálogos de Platão e tê-la intitulado PAN METRON ARISTON

Bacillus Thuringiensis: diversidade gênica em isolados Lepidoptera-específicos.

O presente trabalho teve como objetivo caracterizar geneticamente 1.073 isolados de Bacillus thuringiensis, de três coleções brasileiras, provenientes da UNESP, Jaboticabal, ESALQ - Piracicaba e da EMBRAPA. Sete Lagoas, analisando os tipos de genes cryl apresentados pelos isolados. Para isso, foram elaborados oligonucleotídeos iniciadores a partir de 16 regiões conservadas e 4 regiôes não conservadas das seqüências de cada uma das 16 subclasses do gene cryl. Essas seqüências foram amplificadas por PCR e a presença de amplicons para cada subclasse foi calculada em porcentagem por gene e por coleção. Nessa análise, 55,7'?u dos isolados apresentaram amplificação para o gene cryl, e as subclasses cryl Aa, cryl Al>, cryl Ac. cryl Ad, cryl Ac, cryl Af, cryl 1 Ag, l e cryl 1 Bj; cryl Ca e cryl Fa estão presentes em ai ta proporção de isolados, variando de 43,4 % a 54, 9'?u. Verificou-se que existe uma distribuição das subclasses dentro do banco de isolados de B. thuringiensis em estudo, com maior porcentagem de isolados portadores dos genes cryl Al> (42,12%) e com menor porcentagem de representantes da subclasse cryl D/1 (0,6%). A variabilidade gênica, nas coleções analisadas, destaca as coleções de Jaboticabal e Piracicaba como fontes de isolados promissores para uso em programas de Controle Biológico de pragas da ordem Lepidoptera. A coleção de Sete Lagoas, na qual as freqüências das subclasses estudadas foram reIativamente baixas (a baixo de 20%), destaca somente o gene cryl A/1, presente em 38,5% dos isolados desta coleção

Development and validation of real-time PCR screening methods for detection of cry1A.105 and cry2Ab2 genes in genetically modified organisms

Primers and probes were developed for the element-specific detection of cry1A.105 and cry2Ab2 genes, based on their DNA sequence as present in GM maize MON89034. Cry genes are present in many genetically modified (GM) plants and they are important targets for developing GMO element-specific detection methods. Element-specific methods can be of use to screen for the presence of GMOs in food and feed supply chains. Moreover, a combination of GMO elements may indicate the potential presence of unapproved GMOs (UGMs). Primer-probe combinations were evaluated in terms of specificity, efficiency and limit of detection. Except for specificity, the complete experiment was performed in 9 PCR runs, on 9 different days and by testing 8 DNA concentrations. The results showed a high specificity and efficiency for cry1A.105 and cry2Ab2 detection. The limit of detection was between 0.05 and 0.01 ng DNA per PCR reaction for both assays. These data confirm the applicability of these new primer-probe combinations for element detection that can contribute to the screening for GM and UGM crops in food and feed samples

SILICA MORPHOLOGY CHARACTERIZED BY SEM - THE EFFECTS OF THE SOLVENT TREATMENT AND THE DRYING PROCESS

Scanning electron microscopy (SEM) was used to investigated the effects of volatile solvents (such as water, propanone, ethanol, methanol or ethyl ether), treatment and drying processes, microwave ovens, drying ovens, and vacuum desiccators or freeze driers, on silica morphology. Silica gel was obtained from diluted sodium silicate (1:5 w/w SiO2:H2O). The results showed that the drying process based on freeze drying is more efficient for structural conservation of the precipitate. Treatment with volatile solvents does not change the shape of the aggregates, but has an important role in the determination of aggregate surface roughness

Morphological evolution of zinc oxide originating from zinc hydroxide carbonate

Zinc oxide can be obtained by thermal decomposition of hydrozincite, a topochemical reaction. This work reports the relation between zinc oxide morphology and the precursor zinc hydroxide carbonate precipitation time. The morphological evolution was monitored by SEM, IR and XRD. Zinc oxide obtained from initially precipitated hydrozincite consists of porous spherical aggregates and shows a single Zn-O IR vibrational band. At longer periods of precipitation time the aggregates were transformed into spherulitic-shaped zinc oxide particles showing the Zn-O split vibrational band. X-ray patterns show that the hexagonal zinc oxide phase is substantially increased as a function of hydrozincite precipitation time. © 1997 Elsevier Science S.A

The effect of Eu3+ concentration on the Y2O3 host lattice obtained from citrate precursors

This work presents a thermal decomposition study of the precursor resin prepared from the citrate precursor along with structural features and optical properties materials composed by Y2O3 and Eu3+ containing Y2O3 in 0.5, 3, 5 and 7 mol%. The microcrystallite sizes were estimated from the Scherrer equation. The structural and optical properties revealed that the addition of 5 mol% of Eu3+ to the Y2O3 matrix gave rise to the highest relative emission intensity which was evidenced by the luminescence intensity. The lifetime of the 0.5 mol% Eu3+-doped sample suggested two different symmetry sites for Eu3+ ions because two different lifetime values were acquired for this sample, while for phosphors doped with 3 or 5 mol% of Eu3+ ions only one similar lifetime was observed. When the concentration of Eu3+ is 0.5 and 3 mol%, the luminescence intensity is weak due to the low probability of the O2--Eu3+ charge transfer transition. on the other hand, when the concentration of the Eu3+ ions is 7 mol%, a quenching effect is evidenced. (C) 2008 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Time-resolved spectroscopy studies of Gd2SiO5 : Ce3+ from spherical particles

This paper reports on time-resolved emission and excitation spectra measurement studies of Gd2SiO5:Ce3+ in powder or pellet samples, from spherical particles, in order to assign the Ce3+ ion transitions into two different symmetry sites. Samples were obtained from solid-state reaction of the spherical particles oxides, SiO2 and Gd2O3:Ce3+. From time-resolved spectroscopy measurements Ce3+ ion transitions occupying the two different gadolinium crystallographic sites in Gd2SiO5 were separated and assigned. (C) 2002 Elsevier B.V. B.V. All rights reserved