Stabilization of a light bullet in a layered Kerr medium with sign-changing nonlinearity

Using the numerical solution of the nonlinear Schrodinger equation and a variational method, it is shown that (3+1)-dimensional spatiotemporal optical solitons, known as light bullets, can be stabilized in a layered Kerr medium with sign-changing nonlinearity along the propagation direction.

Mycelial growth and microscopic characteristics of Thermomyces lanuginosus Tsiklinskaya in YpSs medium with different carbon sources

Muitos fungos termofílicos são conhecidos como sendo produtores de lipases e o potencial dessas enzimas nas reações de esterificação (reação inversa à hidrólise), há muito tem sido reconhecida. O aspecto do micélio e diversas observações microscópicas foram efetuadas em Thermomyces lanuginosus cultivado em Placas de Petri com meios de culturas YpSs (extrato de levedura + amido + agar) e mais quatro variações na fonte de carbono neste meio. As matérias-primas usadas e avaliadas foram pentaeritritol, ácido oléico e dioleato de pentaeritritol como possíveis fontes de carbono disponíveis ao microrganismo são comumente encontradas na indústria química como intermediários clássicos na síntese de diversos ésteres. Com o crescimento de Thermomyces lanuginosus em todos os meios propostos e a manutenção da capacidade de reprodução mostramos ser esse fungo altamente promissor em futuros trabalhos de biocatálise com microrganismos vivos.

The comparison of the Butzler medium, filtration technique and their association with isolation of Campylobacter ssp

Do total de 622 amostras de fezes, sendo 200 de suínos, 220 de bezerros e 202 de cães, Campylobacter foi isolado em 178 amostras. Destas, o agente foi identificado em 64 (36%) amostras, isoladas somente em meio seletivo de Butzler (MSB); em 34 (19%) o microorganismo foi isolado a partir da técnica de filtração (TF) e em 80 (45%), através de ambos os procedimentos (MSB+TF). A comparação entre as proporções de positividade, pelas diferentes técnicas, revelou significância (c2 = 9.184; p > 0,001) sendo a MSB (36%) a mais eficiente comparada com a TF (19%) O uso associado de ambos os procedimentos proporcionou a positividade mais elevada de isolamento com 45%.

TiO2 films organofunctionalized with 2-aminothiazole ligand and adsorbed Pd(II) ions applied in the photocatalytic degradation of phenol in an aqueous medium

This paper describes the preparation of thin titanium films via sol-gel route and their subsequent chemical modification by anchoring with 2-aminothiazole ligand and Pd(II) ion sorption, aiming to maximize the photocatalytic activity. The material was characterized by diffuse reflectance infrared Fourier transform spectroscopy, ultraviolet and visible spectrometry, X-ray diffractometry, and scanning electronic microscopy. The amount of palladium adsorbed on the film's surface, determined by graphite furnace atomic absorption spectrometry, showed a value of 2.69 x 10(16) atoms CM-2. The photocatalytic tests indicated that the functionalization with 2-aminothiazole and the adsorption of palladium (II) were determinants in the semiconductor's enhanced photocatalytic activity. (c) 2007 Elsevier B.V. All rights reserved.

Spectrophotometric determination of formaldehyde with chromotropic acid in phosphoric acid medium assisted by microwave oven

In the present study. a spectrophotometric method for the determination of formaldehyde by using chromotropic acid was devised. in which the use of potentially hazardous and corrosive concentrated sulfuric acid was eliminated and advantageously C replaced by a mixture of H, concentrated H3PO4 and H2O2. The reaction between formaldehyde and chromotropic acid (CA) in a cone phosphoric acid medium was accelerate by irradiating the mixture with microwave energy for 35 s (1100 W), producing a violetred compound (lambda(max)=570 nm). Beer's Law is obeyed in a concentration range of 0.8-4.8 mg 1(-1) of formaldehyde with a good correlation coefficient (r = 0.9968). The proposed method was applied in the analysis of formaldehyde in commercial disinfectants. Recoveries were within 98.0-100.4%, with standard deviations ranging from 0.03 to 0.13%. (C) 2003 Elsevier B.V All rights reserved.

Soliton propagation in a medium with Kerr nonlinearity and resonant impurities: A variational approach

The soliton propagation in a medium with Kerr nonlinearity and resonant impurities was studied by a variational approach. The existence of a solitary wave was shown within the framework of a combined nonintegrable system composed of one nonlinear Schrödinger and a pair of Bloch equations. The analytical solution which was obtained, was tested through numerical simulations confirming its solitary wave nature.

Brazilian experience with the medium-term multi-organ bioassay: Scientific and regulatory developments

In 1996 the Brazilian Institute for the Environment (IBAMA) officially adopted a variation of the multiorgan initiation-promotion DMBDD bioassay as a valid source of evidence of the carcinogenic potential of pesticides. The protocol adopted by IBAMA was a modification of the one originally proposed by researchers led by Nobuyuki Ito, from the Nagoya City University Medical School. Among the modifications established in the Brazilian protocol were the use of both sexes of the outbreed Wistar strain of rats and two positive control test chemicals. The adoption of the modified DMBDD protocol was instrumental during the last decade for qualifying technical people and to spread knowledge on chemical carcinogenesis in Brazil.

The Taiwanese experience with small and medium-sized enterprises (SMEs): possible lessons for Latin America and the Caribbean

Includes bibliography

Production of medium-chain-length polyhydroxyalkanoate by Pseudomonas oleovorans grown in sugary cassava extract supplemented with andiroba oil

Pseudomonas oleovorans were grown on sugary cassava extracts supplemented with andiroba oil for the synthesis of a mediumchain- length polyhydroxyalkanoate (PHA_MCL). The concentration of total sugars in the extract was approximately: 40 g/L in culture 1, 15 g/L in cultures 2 and 3, and 10 g/L in culture 4. Supplementation with 1% andiroba oil and 0.2 g/L of (NH₄)₂HPO₄ was performed 6.5 hours after growth in culture 3, and supplementation with the same amount of andiroba oil and 2.4 g/L of (NH₄)₂HPO₄ was performed at the beginning of growth in culture 4. The synthesis resulted mainly in 3-hydroxy-decanoate and 3-hydroxy-dodecanoate units; 3-hydroxy-butyrate, 3-hydroxy-hexanoate; and 3-hydroxy-octanoate monomers were also produced but in smaller proportions. P. oleovorans significantly accumulated PHA_MCL in the deceleration phase of growth with an oxygen limitation but with sufficient nitrogen concentration to maintain cell growth. The sugary cassava extract supplemented with andiroba oil proved to be a potential substrate for PHA_MCL production.

Chronic reparative changes in medium-sized vessels in a case of primary cutaneous anaplastic large-cell lymphoma with angioinvasive features and cytotoxic phenotype: new histopathological findings in line with indolent clinical behavior

Angioinvasion/angiodestruction has been reported in a small subset of primary cutaneous anaplastic large-cell lymphomas (PCALCL). Recently, PCALCL with angioinvasive features and cytotoxic phenotype has been characterized as a variant associated with good clinical outcomes despite worrisome histopathologic features. We report a case of PCALCL with angioinvasive features and cytotoxic phenotype associated with reparative changes on the wall of medium-sized vessels involved by the neoplasm, including intimal fibroblastic proliferation and luminal obliteration. This vascular pattern, although previously unreported in PCALCL, is in accordance with the indolent behavior observed in this entity and provides a further link with lymphomatoid papulosis type E.