Template-based fluoroethylenepropylene piezoelectrets with tubular channels for transducer applications

We describe the concept, the fabrication, and the most relevant properties of a piezoelectric-polymer system: Two fluoroethylenepropylene (FEP) films with good electret properties are laminated around a specifically designed and prepared polytetrafluoroethylene (PTFE) template at 300 degrees C. After removing the PTFE template, a two-layer FEP film with open tubular channels is obtained. For electric charging, the two-layer FEP system is subjected to a high electric field. The resulting dielectric barrier discharges inside the tubular channels yield a ferroelectret with high piezoelectricity. d(33) coefficients of up to 160 pC/N have already been achieved on the ferroelectret films. After charging at suitable elevated temperatures, the piezoelectricity is stable at temperatures of at least 130 degrees C. Advantages of the transducer films include ease of fabrication at laboratory or industrial scales, a wide range of possible geometrical and processing parameters, straightforward control of the uniformity of the polymer system, flexibility, and versatility of the soft ferroelectrets, and a large potential for device applications e.g., in the areas of biomedicine, communications, production engineering, sensor systems, environmental monitoring, etc.

On the template synthesis of nanostructured inorganic/organic hybrid films

Prussian Blue has been introduced as a mediator to achieve stable, sensitive, reproducible, and interference-free biosensors. However, Na(+), Li(+), H(+), and all group II cations are capable to block the activity of Prussian Blue and, because Na(+) can be found in most human fluids, Prussian Blue analogs have already been developed to overcome this problem. These analogs, such as copper hexacyanoferrate, have also been introduced in a conducting polypyrrole matrix to create hybrid materials (copper hexacyanoferrate/polypyrrole, CuHCNFe/Ppy) with improved mechanical and electrochemical characteristics. Nowadays, the challenges in amperometric enzymatic biosensors consist of improving the enzyme immobilization and in making the chemical signal transduction more efficient. The incorporation of nanostructured materials in biosensors can optimize both steps and a nanostructured hybrid CuHCNFe/Ppy mediator has been developed using a template of colloidal polystyrene particles. The nanostructured material has achieved sensitivities 7.6 times higher than the bulk film during H(2)O(2) detection and it has also presented better results in other analytical parameters such as time response and detection limit. Besides, the nanostructured mediator was successfully applied at glucose biosensing in electrolytes containing Prussian Blue blocking cations. (C) 2008 The Electrochemical Society.

Ciratefi: An RST-invariant template matching with extension to color images

Template matching is a technique widely used for finding patterns in digital images. A good template matching should be able to detect template instances that have undergone geometric transformations. In this paper, we proposed a grayscale template matching algorithm named Ciratefi, invariant to rotation, scale, translation, brightness and contrast and its extension to color images. We introduce CSSIM (color structural similarity) for comparing the similarity of two color image patches and use it in our algorithm. We also describe a scheme to determine automatically the appropriate parameters of our algorithm and use pyramidal structure to improve the scale invariance. We conducted several experiments to compare grayscale and color Ciratefis with SIFT, C-color-SIFT and EasyMatch algorithms in many different situations. The results attest that grayscale and color Ciratefis are more accurate than the compared algorithms and that color-Ciratefi outperforms grayscale Ciratefi most of the time. However, Ciratefi is slower than the other algorithms.

Rotation-discriminating template matching based on Fourier coefficients of radial projections with robustness to scaling and partial occlusion

We consider brightness/contrast-invariant and rotation-discriminating template matching that searches an image to analyze A for a query image Q We propose to use the complex coefficients of the discrete Fourier transform of the radial projections to compute new rotation-invariant local features. These coefficients can be efficiently obtained via FFT. We classify templates in ""stable"" and ""unstable"" ones and argue that any local feature-based template matching may fail to find unstable templates. We extract several stable sub-templates of Q and find them in A by comparing the features. The matchings of the sub-templates are combined using the Hough transform. As the features of A are computed only once, the algorithm can find quickly many different sub-templates in A, and it is Suitable for finding many query images in A, multi-scale searching and partial occlusion-robust template matching. (C) 2009 Elsevier Ltd. All rights reserved.

Dynamic susceptibility investigation of maghemite nanoparticles incorporated in bovine serum albumin template

Room-temperature measurements of the magnetic susceptibility of Bovine Serum Albumin-based nanocapsules (50 to 300 nm in size) loaded with different amounts of maghemite nanoparticles (7.6 nm average diameter) have been carried out in this study The field (H) dependence of the imaginary peak susceptibility (f(P)) of the nanocomposite samples was investigated in the range of 0 to 4 kOe. From the analysis of the f(P) x H curves the concentration (N) dependence of the effective maghemite magnetocrystalline energy barrier (E) was obtained. Analysis of the E x N data was performed using a modified Morup-Tronc [Phys. Rev. Lett. 72, 3278 (1994)] model, from which a huge contribution from the magnetocrystalline surface anisotropy was observed.

Template-based quadrilateral meshing

Generating quadrilateral meshes is a highly non-trivial task, as design decisions are frequently driven by specific application demands. Automatic techniques can optimize objective quality metrics, such as mesh regularity, orthogonality, alignment and adaptivity; however, they cannot make subjective design decisions. There are a few quad meshing approaches that offer some mechanisms to include the user in the mesh generation process; however, these techniques either require a large amount of user interaction or do not provide necessary or easy to use inputs. Here, we propose a template-based approach for generating quad-only meshes from triangle surfaces. Our approach offers a flexible mechanism to allow external input, through the definition of alignment features that are respected during the mesh generation process. While allowing user inputs to support subjective design decisions, our approach also takes into account objective quality metrics to produce semi-regular, quad-only meshes that align well to desired surface features. Published by Elsevier Ltd.

Estabilidade oxidativa e microbiol��gica em carne de galinha mecanicamente separada e adicionada de antioxidantes durante per��odo de armazenamento a -18 °C

Com o objetivo de acompanhar a estabilidade f��sico-qu��mica e microbiol��gica da carne mecanicamente separada (CMS) de diferentes origens e estocada durante 99 dias a -18 °C, foi realizada pr��via mistura de conservante (nitrito de s��dio) e antioxidante (eritorbato de s��dio) em CMS obtida de duas linhagens de aves: galinhas matrizes de corte e galinhas poedeiras comerciais brancas. Na CMS de cada linhagem foram realizados tr��s diferentes tratamentos: 1) controle (sem aditivos); 2) adi����o de 150 ppm de nitrito; e 3) adi����o de 150 ppm de nitrito e 500 ppm de eritorbato. Os resultados encontrados demonstraram que a adi����o de nitrito isoladamente n��o impediu a oxida����o lip��dica, avaliada atrav��s do ��ndice de TBARS, nem a altera����o na cor, avaliada em color��metro. Por outro lado, a adi����o de nitrito juntamente com eritorbato foi efetiva na redu����o dos problemas de oxida����o lip��dica na CMS de galinhas matrizes, e em menor grau, na CMS de poedeiras. A adi����o de nitrito e eritorbato na CMS tamb��m melhorou a preserva����o da cor vermelha desej��vel (a*) ao longo do tempo. A avalia����o da estabilidade microbiol��gica da CMS, realizada no primeiro e ��ltimo dia de estocagem congelada, para microrganismos mes��filos, Escherichia coli, Staphylococcus aureus, Clostridium perfringens e Pseudomonas spp., e quinzenalmente para microrganismos psicrotr��ficos, indicou que n��o houve uma varia����o significativa nas contagens em fun����o do tratamento utilizado (diferentes aditivos adicionados). N��o foi detectada Salmonella spp. em nenhuma das amostras analisadas. Em fun����o da melhoria da estabilidade oxidativa, recomenda-se a adi����o de nitrito (150 ppm) e eritorbato (500 ppm) em CMS de galinhas matrizes a ser estocada congelada por um per��odo prolongado.

Vitaminas D e C para poedeiras na fase inicial de produ����o de ovos

Um experimento foi conduzido com o objetivo de avaliar os efeitos de duas fontes de vitamina D e tr��s n��veis de vitamina C sobre as caracter��sticas de desempenho, a qualidade interna e externa dos ovos, os n��veis de c��lcio total e i��nico s��ricos e a resist��ncia ��ssea de poedeiras. Foram utilizadas 288 galinhas da linhagem ISA Babcock B300�� com 23 semanas de idade, durante um per��odo experimental de 12 semanas. Utilizou-se o delineamento inteiramente ao acaso em arranjo fatorial 2 × 3, com os fatores: fontes de vitamina D (colecalciferol e 25-hidroxicolecalciferol - 25(OH)D3) e de vitamina C (0, 100 e 200 ppm), totalizando seis tratamentos com oito repeti����es de seis aves. O n��vel basal de colecalciferol foi de 2.756 UI/kg, correspondendo a 5,51 g do produto comercial Hy.D��/t de ra����o, como fonte de 25(OH)D3. Os fatores estudados n��o influenciaram o consumo de ra����o, a produ����o, o peso e a massa de ovos. Observou-se efeito da intera����o de fontes de vitamina sobre a convers��o alimentar, que foi melhor quando utilizado metab��lito 25(OH)D3 na aus��ncia de vitamina C. Intera����es foram observadas para porcentagem de alb��men e porcentagem de gema, que aumentaram na presen��a de 200 ppm de vitamina C. O peso espec��fico dos ovos, as concentra����es de c��lcio s��rico, cinzas ��sseas e a resist��ncia �� quebra n��o foram influenciadas pelas fontes de vitamina D e C. Houve intera����o para porcentagem e espessura de casca, cujos maiores valores foram obtidos com a suplementa����o de vitamina C na presen��a de 25(OH)D3. Em poedeiras na fase inicial de produ����o, a convers��o alimentar �� melhor com a utiliza����o do 25(OH)D3 e a espessura e porcentagem de casca tamb��m melhoram com a utiliza����o de 25(OH)D3 e a suplementa����o de vitamina C nas dietas (100 ou 200 ppm, respectivamente).

Efeito da lavagem e da adi����o de aditivos sobre a estabilidade de carne mecanicamente separada de til��pia do Nilo (Oreochromis niloticus) durante estocagem a -18 ��C

Este estudo teve como objetivo avaliar a influ��ncia da lavagem e da adi����o de eritorbato de s��dio e tripolifosfato de s��dio na estabilidade de Carne Mecanicamente Separada (CMS) de til��pia de Nilo (Oreochromis niloticus) durante 6 meses de armazenamento a -18 ��C. A CMS obtida por meio de m��quina separadora de carne e ossos foi dividida em quatro tratamentos (CMS lavada com e sem aditivos, e CMS n��o lavada com e sem aditivos) e mantida sob congelamento a -18 ��C, por 180 dias. A estabilidade foi avaliada por meio de an��lises microbiol��gicas e determina����es de nitrog��nio n��o proteico (NNP), bases nitrogenadas vol��teis (BNV), subst��ncias reativas ao ��cido tiobarbit��rico (TBARS), pH e drip (perda de ��gua no descongelamento). O processo de lavagem causou redu����o de aproximadamente 41, 44 e 66% nos teores de prote��na bruta, lip��dios e cinzas, respectivamente, reduzindo tamb��m os valores iniciais de NNP, BNV e TBARS. Durante o armazenamento, foram observados aumentos (p < 0,05) nos teores de NNP, BNV e pH em praticamente todos os tratamentos, exceto na CMS lavada com aditivos, que n��o apresentou aumentos significativos nos teores de NNP e pH. O uso de aditivos nas CMS diminuiu o drip ao longo do armazenamento, mas n��o alterou (p > 0,05) os teores de TBARS. Os par��metros microbiol��gicos avaliados n��o ultrapassaram os limites permitidos pela legisla����o. As CMS permaneceram est��veis e em boas condi����es de utiliza����o, independentemente da inclus��o de aditivo, sendo vi��vel sua estocagem a -18 ��C por 180 dias.

Phylogenetic analyses of Cladophora vagabunda (L.) C. Hoek (Cladophorales, Chlorophyta) from Brazil based on SSU rDNA sequences

The complete SSU rDNA was sequenced for 10 individuals of Cladophora vagabunda collected along the coast of Brazil. For C. rupestris (L.) K��tz. a partial SSU rDNA sequence (1634 bp) was obtained. Phylogenetic trees indicate that Cladophora is paraphyletic, but the section Glomeratae sensu lato including C. vagabunda from Brazil, Japan and France, C. albida (Nees) K��tz., C. sericea (Hudson) K��tz., and C. glomerata (L.) K��tz. is monophyletic. Within this group C. vagabunda is paraphyletic. The sequence identity for the SSU rDNA varied from 98.9% to 100% for the Brazilian C. vagabunda, and from 98.3% to 99.7% comparing the Brazilian individuals to the ones from France and Japan. Sequence identity of the Brazilian C. vagabunda to C. albida and C. sericea vary from 98.0% to 98.6%. The SSU rDNA phylogeny support partially the morphological characteristics presented by Brazilian populations of C. vagabunda. On the other hand, C. rupestris from Brazil does not group with C. rupestris from France, both sequences presenting only 96.9% of identity. The inclusion of sequences of individuals from Brazil reinforces the need of taxonomical revision for the genus Cladophora and for the complex C. vagabunda.

Deleterious effect of TRIS buffer on growth rates and pigment content of Gracilaria birdiae Plastino & E.C. Oliveira (Gracilariales, Rhodophyta)

This work evaluated the effects of Tris (hydroxymethyl)-aminomethane (TRIS) buffer and its interaction with nutrient concentration on the development of Gracilaria birdie, a common species on the Brazilian coast that has been exploited for agar production. Responses to different conditions were assessed through growth rates and pigment content (chlorophyll a, phycoerythrin, phycocyanin and allophycocyanin). Provasoli's nutrient solution with and without TRIS addition was tested at concentrations of 12.5, 25 and 50%. The pH was also monitored. G. birdiae grew better in the absence of TRIS and at low nutrient concentrations, 12.5 and 25% (growth rates of 10.8-11.3%.day-1). Higher contents of phycoerythrin and chlorophyll a were observed without TRIS at 12.5 and 25% (Phycoerythrin, 649.6-698.0 &#956;g g-1 fresh biomass; Chlorophyll a, 156.0-168.6 &#956;g g-1 fresh biomass). These findings highlight the deleterious effect of TRIS on growth and phycoerythrin and chlorophyll a content. They also demonstrate the importance of appropriate nutrient concentration for laboratory cultures, depending on the intrinsic characteristics of each species.

Phenology of an agarophyte Gracilaria birdiae Plastino and E.C. Oliveira (Gracilariales, Rhodophyta) in Northeastern Brazil

The reproductive phenology and thallus length of Gracilaria birdiae were studied over a period of 12 months in a natural bed in Northeastern Brazil. Fertile specimens of G. birdiae were observed during the entire study period. Tetrasporophytes were the most common with an annual mean of 80.1��5.6%, followed by cystocarpic plants (9.3��3.4%), male gametophytes (8.3��3.6%) and infertile plants (2.2��3.4%). Only male gametophytes and infertile plants showed a variation in occurrence frequency during the year (p<0.05). With respect to thallus length, a distinct seasonal variation was observed for all reproductive stages (p<0.05), with the highest values recorded during the rainy season (March to August) and the lowest in the dry season (September to February). The results demonstrate that the size of individuals in this population is significantly affected by the periodic changes in the environment caused by rainfall regimes and hydrodynamism.

COL18A1 is highly expressed during human adipocyte differentiation and the SNP c.1136C > T in its "frizzled" motif is associated with obesity in diabetes type 2 patients

Collagen XVIII can generate two fragments, NC11-728 containing a frizzled motif which possibly acts in Wnt signaling and Endostatin, which is cleaved from the NC1 and is a potent inhibitor of angiogenesis. Collagen XVIII and Wnt signaling have recently been associated with adipogenic differentiation and obesity in some animal models, but not in humans. In the present report, we have shown that COL18A1 expression increases during human adipogenic differentiation. We also tested if polymorphisms in the Frizzled (c.1136C>T; Thr379Met) and Endostatin (c.4349G>A; Asp1437Asn) regions contribute towards susceptibility to obesity in patients with type 2 diabetes (113 obese, BMI =30; 232 non-obese, BMI < 30) of European ancestry. No evidence of association was observed between the allele c.4349G>A and obesity, but we observed a significantly higher frequency of homozygotes c.1136TT in obese (19.5%) than in non-obese individuals (10.9%) [P = 0.02; OR = 2.0 (95%CI: 1.07-3.73)], suggesting that the allele c.1136T is associated to obesity in a recessive model. This genotype, after controlling for cholesterol, LDL cholesterol, and triglycerides, was independently associated with obesity (P = 0.048), and increases the chance of obesity in 2.8 times. Therefore, our data suggest the involvement of collagen XVIII in human adipogenesis and susceptibility to obesity.

Avalia����o da cicatriza����o de feridas em dorso de ratos tratados com mitomicina C t��pica e posterior refor��o com injet��vel

Estudo experimental em animais. A mitomicina C vem sendo usada como inibidor de fibroblastos, acarretando, com isso, diminui����o do processo cicatricial em feridas cir��rgicas. OBJETIVO: Este trabalho visa avaliar o uso de Mitomicina C para diminuir o processo cicatricial, atrav��s de seu uso t��pico com refor��os posteriores injet��veis. MATERIAL E M��TODOS: Foi usado um modelo de feridas em dorso de ratos, com retirada circular da pele e cicatriza����o por segunda inten����o. Foram usados 18 ratos, divididos em tr��s grupos: controle; com uso t��pico; e com refor��o de mitomicina C injet��vel, mensalmente e por 2 meses. Ap��s 3 meses os animais foram sacrificados e as cicatrizes retiradas cirurgicamente e submetidas a estudo histol��gico. RESULTADOS: Notou-se sob v��rios crit��rios que a cicatriza����o com o uso t��pico �� menos intensa, mas ao se usar o refor��o injet��vel os par��metros voltam a ser comparados ao do grupo controle. DISCUSS��O: Acreditamos que a administra����o injet��vel de mitomicina C nas cicatrizes, pela sua elevada caracter��stica t��xica, acarreta destrui����o tecidual e neoforma����o cicatricial. CONCLUS��ES: A mitomicina C diminui o processo cicatricial quando usada topicamente, mas acarreta aumento da cicatriza����o quando nestas feridas s��o feitos refor��os injet��veis.

��cido clavul��nico e cefamicina c: uma perspectiva da bioss��ntese, processos de isolamento e mecanismo de a����o

The present article reviews different aspects of the chemistry of two widely used &#946;-lactam antibiotics Clavulanic Acid and Cephamycin C. The article discusses important details of the biosynthesis of these compounds, their action mechanism and, principally, the methods employed in their isolation and purification, in accordance with the available literature. Despite the large quantity of available articles and patents concerning &#946;-lactam antibiotics, those which describe the isolation and purification of Clavulanic Acid and Cephamycin C are rare. Overall, the intention of this article is to discuss the up-to-date scientific research related to the compounds under review.