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The aim of the present study was to evaluate the antibacterial behavior of polypyrrole nanoparticles (PPy-NPs) in water against biofilm producer or not S. aureus isolated from cows and goats with mastitis. One hundred and thirty-eight isolates of S. aureus were initially evaluated for biofilm formation by spectrophotometry in microplates. In addition, the minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) of PPy-NPs in water for planktonic S. aureus were determined. From the bovine samples analyzed, 5 (4.46%) S. aureus isolates showed a strong biofilm production, 17 (15.18%) moderate production, 36 (32.14%) with weak production and 54 (48.21%) did not produce biofilms. Strains from goats (26) showed no biofilm production in 18 (69.23%) strains and weak biofilm production in 8 (30.76%) strains. The MIC and MBC of S. aureus to PPy-NPs were found in the same concentration (125搭/mL) in all strains tested, regardless of biofilm production or not. This finding provides a new insight into the interaction between PPy-NPs and S. aureus, and will offer potential benefits for the control of mastitis.(AU)

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The aim of the present study was to evaluate the antibacterial behavior of polypyrrole nanoparticles (PPy-NPs) in water against biofilm producer or not S. aureus isolated from cows and goats with mastitis. One hundred and thirty-eight isolates of S. aureus were initially evaluated for biofilm formation by spectrophotometry in microplates. In addition, the minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) of PPy-NPs in water for planktonic S. aureus were determined. From the bovine samples analyzed, 5 (4.46%) S. aureus isolates showed a strong biofilm production, 17 (15.18%) moderate production, 36 (32.14%) with weak production and 54 (48.21%) did not produce biofilms. Strains from goats (26) showed no biofilm production in 18 (69.23%) strains and weak biofilm production in 8 (30.76%) strains. The MIC and MBC of S. aureus to PPy-NPs were found in the same concentration (125搭/mL) in all strains tested, regardless of biofilm production or not. This finding provides a new insight into the interaction between PPy-NPs and S. aureus, and will offer potential benefits for the control of mastitis.(AU)

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AIMS: This study aimed to verify the formation of biofilms by Moraxella bovis, Moraxella ovis and Moraxella bovoculi isolates from ruminants. In addition, the lysozyme activity against the isolates of M. bovis, M. ovis and M. bovoculi in free form and in biofilms was determined. METHODS AND RESULTS: In this study, 54 isolates of Moraxella sp. obtained from bovine and ovine clinical samples were evaluated in vitro for capacity of biofilm formation and lysozyme susceptibility in planktonic and sessile cells. In addition, biofilms produced by four Moraxella sp. isolates were visualized under scanning electron microscope (SEM). It was possible to demonstrate, for the first time, the ability to form biofilms by M. ovis and M. bovoculi. The isolates of Moraxella sp. have the capacity to form biofilms in different intensities, varying among weak, moderate and strong. It was verified that the lysozyme shows activity on Moraxella sp. in planktonic form. However, on biofilms there was a reduction in the production, but without impairing its formation, and on consolidated biofilms the lysozyme did not have the capacity to eradicate the preformed biofilms. CONCLUSIONS: This work shows the capacity of biofilm formation by Moraxella sp. of veterinary importance. The lysozyme susceptibility of Moraxella sp. in planktonic form shows that this enzyme has bacteriostatic activity on this micro-organism and it reduced the production of biofilms. SIGNIFICANCE AND IMPACT OF THE STUDY: Based on the results, it is possible to infer that the biofilm formation capacity by Moraxella sp. and the resistance to lysozyme concentrations equal to or greater than the physiological levels of the ruminant tear may be linked not only to the capacity to colonize the conjunctiva, but also to remain in this place even after healing of the lesions, being a reservoir of Moraxella sp. in a herd.

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This study describes lesions that occur in the stifle joints of dogs with patellar luxation. These lesions are associated with the animal's age, body weight, and degree of luxation. The rate of redislocation was also evaluated. The patellar lesions found include articular cartilage erosion, subchondral bone exposure, a flattened or concave patellar surface, and enthesophytes. Extra-patellar lesions included synovitis, osteophytes, blunting of the trochlear groove, an absent trochlea, erosion of the condylar margins, capsule thickening, a long digital extensor tendon injury, cranial cruciate ligament rupture, and meniscal prolapse. Such lesions were frequently found in animals with Grade II or III luxation who were aged 24 months or more, and they were more severe in dogs weighing more than 15 kg. Patellar luxation causes changes that favor articular degeneration and should be treated surgically. Conservative treatment relieves pain, but does not address tissue alterations.(AU)

O estudo descreve as lesões articulares em cães com luxação de patela. Elas foram associadas com a idade do animal, massa corporal e grau de luxação. Foi avaliada também a porcentagem de casos com recidiva. As lesões patelares observadas foram erosão da cartilagem articular, exposição óssea subcondral, superfície patelar achatada ou côncava e entesófitos. As lesões extra patelares incluíram sinovite, osteófitos, ausência do sulco troclear, erosão das bordas condilares, espessamento da cápsula, lesão do tendão do músculo extensor digital, ruptura do ligamento cruzado cranial e prolapso de menisco. As lesões foram encontradas com maior frequência em animais com luxação de Grau II ou III e idade de 24 meses ou mais, sendo mais graves em cães com massa corporal superior a 15 kg. A luxação patelar ocasiona alterações que favorecem a degeneração articular e devem ser tratadas cirurgicamente. O tratamento conservativo alivia a dor, mas não corrige as alterações teciduais.(AU)

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This study describes lesions that occur in the stifle joints of dogs with patellar luxation. These lesions are associated with the animal's age, body weight, and degree of luxation. The rate of redislocation was also evaluated. The patellar lesions found include articular cartilage erosion, subchondral bone exposure, a flattened or concave patellar surface, and enthesophytes. Extra-patellar lesions included synovitis, osteophytes, blunting of the trochlear groove, an absent trochlea, erosion of the condylar margins, capsule thickening, a long digital extensor tendon injury, cranial cruciate ligament rupture, and meniscal prolapse. Such lesions were frequently found in animals with Grade II or III luxation who were aged 24 months or more, and they were more severe in dogs weighing more than 15 kg. Patellar luxation causes changes that favor articular degeneration and should be treated surgically. Conservative treatment relieves pain, but does not address tissue alterations.(AU)

O estudo descreve as lesões articulares em cães com luxação de patela. Elas foram associadas com a idade do animal, massa corporal e grau de luxação. Foi avaliada também a porcentagem de casos com recidiva. As lesões patelares observadas foram erosão da cartilagem articular, exposição óssea subcondral, superfície patelar achatada ou côncava e entesófitos. As lesões extra patelares incluíram sinovite, osteófitos, ausência do sulco troclear, erosão das bordas condilares, espessamento da cápsula, lesão do tendão do músculo extensor digital, ruptura do ligamento cruzado cranial e prolapso de menisco. As lesões foram encontradas com maior frequência em animais com luxação de Grau II ou III e idade de 24 meses ou mais, sendo mais graves em cães com massa corporal superior a 15 kg. A luxação patelar ocasiona alterações que favorecem a degeneração articular e devem ser tratadas cirurgicamente. O tratamento conservativo alivia a dor, mas não corrige as alterações teciduais.(AU)

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Two experiments were performed to evaluate the hematological and blood biochemistry parameters, biometry of digestive organs, enzyme activities, protein content and absolute weight of the pancreas of broilers fed pre-starter and pre-starter diets supplemented or not with amylase from Aspergillus awamori. In total, 120 male Cobb chicks were housed in heated cages in each experiment. A completely randomized experimental design, with two treatments (feed with and without amylase) and six replicates per treatment of 10 birds each was applied. The data were subjected to analysis of variance using the F-test at 5% probability level. The dietary amylase addition did not affect hematological and blood biochemistry parameters and the biometry of the gastrointestinal tract of 7- and 21-d-old broilers, nor the absolute weight, enzyme activities or protein concentration of the pancreas of 7-d-old broilers. However, the inclusion of amylase in the diet reduced amylase activity and pancreatic protein concentration in 21-d-old broilers. The application of amylase to broiler chicken pre-starter and starter feeds is not justified given the pancreatic amylase activity and protein concentrations.

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Two experiments were performed to evaluate the hematological and blood biochemistry parameters, biometry of digestive organs, enzyme activities, protein content and absolute weight of the pancreas of broilers fed pre-starter and pre-starter diets supplemented or not with amylase from Aspergillus awamori. In total, 120 male Cobb chicks were housed in heated cages in each experiment. A completely randomized experimental design, with two treatments (feed with and without amylase) and six replicates per treatment of 10 birds each was applied. The data were subjected to analysis of variance using the F-test at 5% probability level. The dietary amylase addition did not affect hematological and blood biochemistry parameters and the biometry of the gastrointestinal tract of 7- and 21-d-old broilers, nor the absolute weight, enzyme activities or protein concentration of the pancreas of 7-d-old broilers. However, the inclusion of amylase in the diet reduced amylase activity and pancreatic protein concentration in 21-d-old broilers. The application of amylase to broiler chicken pre-starter and starter feeds is not justified given the pancreatic amylase activity and protein concentrations.(AU)

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O objetivo do presente trabalho foi avaliar o produto iônico do biovidro 60S (BV60S) na diferenciação osteogênica de células-tronco mesenquimais de origem adiposa (CTM-AD) de cães. As CTM-AD foram diferenciadas sem OSTe com o produto iônico (PI OST) por sete, 14 e 21 dias. Avaliou-se o MTT, a fosfatase alcalina (FA), o colágeno, mineralização e as expressões de osterix (OSX), sialoproteína óssea (BSP), osteonectina (ON) e osteocalcina (OC). O grupo PI OSTmostrou menor conversão de MTT aos sete dias e maior conversão aos 21 dias. A atividade de FA foi maior no grupo OST, aos 14 e 21 dias. A síntese de colágeno foi maior no grupo OST aos sete e 21 dias. Verificou-se maior área mineralizada no grupo PI OSTem todos os tempos. Não houve diferenças nas expressões de OSX e OC entre os grupos. Observou-se maior expressão de BSP no grupo PI OST, aos 14 e 21 dias. A expressão de ON foi maior no grupo OST aos 14 dias. Concluiu-se que o produto iônico do BV60S favorece a osteogênese in vitro de CTM-AD de cães.(AU)

The aim was to evaluate the ionic product of 60S bioglass (BV60S) in osteogenic differentiation of mesenchymal stem cells from adipose tissue (ADMSCs) in dogs. ADMSCs were differentiated without the ionic product (OST) and with the ionic product (PI-OST) for 7, 14 and 21 days. We evaluated the MTT, alkaline phosphatase (ALP), collagen mineralization and expressions of osterix (OSX), bone sialoprotein (BSP), osteonectin (ON) and osteocalcin (OC). The PI-OST group had a lower MTT conversion to 7days and higher conversion at 21 days. The ALP activity was higher in the OST group at 14 and 21 days. Collagen synthesis was higher in the OST group at 7 and 21 days. A higher mineralized area in the PI-OST group was observed at all times. There were no differences in expressions of OSX and OC between groups. We observed increased expression of BSP in the PI-OST group at 14 and 21 days. The expression of ON was higher in the OST group at 14 days. It was concluded that the ionic product of BV60S promotes in vitro osteogenesis of MSC-AD from dogs.(AU)

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O objetivo do presente trabalho foi avaliar o produto iônico do biovidro 60S (BV60S) na diferenciação osteogênica de células-tronco mesenquimais de origem adiposa (CTM-AD) de cães. As CTM-AD foram diferenciadas sem OSTe com o produto iônico (PI OST) por sete, 14 e 21 dias. Avaliou-se o MTT, a fosfatase alcalina (FA), o colágeno, mineralização e as expressões de osterix (OSX), sialoproteína óssea (BSP), osteonectina (ON) e osteocalcina (OC). O grupo PI OSTmostrou menor conversão de MTT aos sete dias e maior conversão aos 21 dias. A atividade de FA foi maior no grupo OST, aos 14 e 21 dias. A síntese de colágeno foi maior no grupo OST aos sete e 21 dias. Verificou-se maior área mineralizada no grupo PI OSTem todos os tempos. Não houve diferenças nas expressões de OSX e OC entre os grupos. Observou-se maior expressão de BSP no grupo PI OST, aos 14 e 21 dias. A expressão de ON foi maior no grupo OST aos 14 dias. Concluiu-se que o produto iônico do BV60S favorece a osteogênese in vitro de CTM-AD de cães.

The aim was to evaluate the ionic product of 60S bioglass (BV60S) in osteogenic differentiation of mesenchymal stem cells from adipose tissue (ADMSCs) in dogs. ADMSCs were differentiated without the ionic product (OST) and with the ionic product (PI-OST) for 7, 14 and 21 days. We evaluated the MTT, alkaline phosphatase (ALP), collagen mineralization and expressions of osterix (OSX), bone sialoprotein (BSP), osteonectin (ON) and osteocalcin (OC). The PI-OST group had a lower MTT conversion to 7days and higher conversion at 21 days. The ALP activity was higher in the OST group at 14 and 21 days. Collagen synthesis was higher in the OST group at 7 and 21 days. A higher mineralized area in the PI-OST group was observed at all times. There were no differences in expressions of OSX and OC between groups. We observed increased expression of BSP in the PI-OST group at 14 and 21 days. The expression of ON was higher in the OST group at 14 days. It was concluded that the ionic product of BV60S promotes in vitro osteogenesis of MSC-AD from dogs.

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The aim of this study was to modify canine coxofemoral prostheses and the clinical evaluation of the implantation. Fifteen canine hips and femora of cadavers were used in order to study the surface points of modification in prostheses and develop a perforation guide. Femoral stems and acetabular components were perforated and coated with biphasic calcium phosphate layer. Twelve young adult male mongrel dogs were implanted with coxofemoral prostheses. Six were operated upon and implanted with cemented canine modular hip prostheses, establishing the control group. The remaining six were implanted with a novel design of cementless porous tricalcic phosphate-hydroxyapatite coated hip prostheses. Clinical and orthopedic performance, complications, and thigh muscular hypotrophy were assessed up to the 120th post-operatory day. After 120 days, animals with cementless prostheses had similar clinical and orthopedic performance compared to the cemented group despite the increased pain thigh hypotrophy. Animals that underwent cementless hip prosthesis evidenced more pain, compared to animals with cemented hip prosthesis that required longer recuperation time. No luxations, two fractures and two isquiatic neurapraxies were identified in the course of the study. Using both the cemented and the bioactive coated cementless model were suitable to dogs, showing clinical satisfactory results. Osseointegration and biological fixation were observed in the animals with the modified cementless hip prosthesis.

O objetivo deste estudo foi modificar a prótese coxofemoral canina cimentada e avaliar os efeitos clínicos. Foram utilizadas 15 pelves e 15 fêmures de cadáveres de cães para modificações da haste, do componente acetabular e para a confecção de guia de perfuração. As hastes e componentes acetabulares foram perfurados e revestidos com uma camada de fosfato de cálcio bifásico. Doze cães machos, adultos jovens, sem raça definida, foram submetidos à cirurgia para o implante de prótese coxofemoral total. Seis cães receberam prótese modular cimentada, grupo controle, e seis, a prótese modificada não cimentada com revestimento de fosfato de cálcio bifásico. Foram avaliados a técnica de implantação, o desempenho clínico, o grau de hipotrofia muscular da coxa e as complicações durante 120 dias. Os animais com prótese não cimentada mostraram desempenho clínico similar aos animais com a prótese cimentada, porém mostraram maior hipotrofia muscular decorrente de dor e maior tempo de recuperação. Não foram observadas luxações. No entanto, duas fraturas e dois casos de neurapraxia isquiádica foram observados. A utilização de ambas as próteses coxofemorais, cimentada e não cimentada, com recobrimento bioativo são eficientes no cão, com resultados clínicos satisfatórios, mas a osteointegração e fixação biológica ocorreram na prótese com recobrimento de fosfato de cálcio bifásico, objetivo do tratamento que previne afrouxamento futuro.

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The aim of this study was to modify canine coxofemoral prostheses and the clinical evaluation of the implantation. Fifteen canine hips and femora of cadavers were used in order to study the surface points of modification in prostheses and develop a perforation guide. Femoral stems and acetabular components were perforated and coated with biphasic calcium phosphate layer. Twelve young adult male mongrel dogs were implanted with coxofemoral prostheses. Six were operated upon and implanted with cemented canine modular hip prostheses, establishing the control group. The remaining six were implanted with a novel design of cementless porous tricalcic phosphate-hydroxyapatite coated hip prostheses. Clinical and orthopedic performance, complications, and thigh muscular hypotrophy were assessed up to the 120th post-operatory day. After 120 days, animals with cementless prostheses had similar clinical and orthopedic performance compared to the cemented group despite the increased pain thigh hypotrophy. Animals that underwent cementless hip prosthesis evidenced more pain, compared to animals with cemented hip prosthesis that required longer recuperation time. No luxations, two fractures and two isquiatic neurapraxies were identified in the course of the study. Using both the cemented and the bioactive coated cementless model were suitable to dogs, showing clinical satisfactory results. Osseointegration and biological fixation were observed in the animals with the modified cementless hip prosthesis.(AU)

O objetivo deste estudo foi modificar a prótese coxofemoral canina cimentada e avaliar os efeitos clínicos. Foram utilizadas 15 pelves e 15 fêmures de cadáveres de cães para modificações da haste, do componente acetabular e para a confecção de guia de perfuração. As hastes e componentes acetabulares foram perfurados e revestidos com uma camada de fosfato de cálcio bifásico. Doze cães machos, adultos jovens, sem raça definida, foram submetidos à cirurgia para o implante de prótese coxofemoral total. Seis cães receberam prótese modular cimentada, grupo controle, e seis, a prótese modificada não cimentada com revestimento de fosfato de cálcio bifásico. Foram avaliados a técnica de implantação, o desempenho clínico, o grau de hipotrofia muscular da coxa e as complicações durante 120 dias. Os animais com prótese não cimentada mostraram desempenho clínico similar aos animais com a prótese cimentada, porém mostraram maior hipotrofia muscular decorrente de dor e maior tempo de recuperação. Não foram observadas luxações. No entanto, duas fraturas e dois casos de neurapraxia isquiádica foram observados. A utilização de ambas as próteses coxofemorais, cimentada e não cimentada, com recobrimento bioativo são eficientes no cão, com resultados clínicos satisfatórios, mas a osteointegração e fixação biológica ocorreram na prótese com recobrimento de fosfato de cálcio bifásico, objetivo do tratamento que previne afrouxamento futuro.(AU)

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Avaliaram-se, por meio de estudo retrospectivo, o perfil epidemiológico, os sinais clínicos, as técnicas cirúrgicas utilizadas e a recuperação de cães apresentados para tratamento de luxação de patela no Hospital Veterinário da UFMG, no período de 2000 a 2010. Utilizaram-se as fichas clínico-cirúrgicas dos cães e registraram-se os dados referentes a cada animal. Foram estudadas 342 articulações nos registros de 210 animais. A luxação medial congênita bilateral foi a apresentação mais frequente, e as fêmeas foram mais acometidas. A idade dos animais variou de 32 dias a 16 anos, com maior ocorrência da luxação nos animais com até um ano de idade e massa corporal inferior a 9,1kg. Em 11,7% dos membros, a luxação era de grau I, em 39,8% grau II, em 20,5% grau III e em 28% grau IV. A frequência de claudicação pré-operatória foi maior nos cães com luxações graus III e IV. Das 342 articulações, 218 foram submetidas à cirurgia. Na avaliação pós-operatória, os animais com luxação grau IV mostraram maior frequência de claudicação. A luxação patelar acomete principalmente fêmeas, sendo a luxação congênita bilateral a apresentação mais comum, e animais jovens e de pequeno porte são mais susceptíveis. A recuperação funcional pós-operatória nas luxações grau IV é lenta e parcial.

The epidemiological profile, clinical signs, and surgical techniques used and the recovery of dogs presented for treatment of patellar luxation in the Veterinary Hospital of UFMG in the period from 2000 to 2010 were evaluated through a retrospective study. The clinical and surgical records of dogs and the data recorded for each animal were used. 342 joints in the records of 210 animals were studied. The congenital bilateral medial luxation was the most frequent occurrence and females were more affected. The age of the animals ranged from 32 days to 16 years, with higher incidence of luxation in animals under one year of age and body mass below 9.1kg. In 11.7% of the members had grade I luxation, 39.8% were grade II, 20.5% were grade III and 28% were grade IV. The frequency of preoperative claudicating was higher in dogs with luxation grades III and IV. Of the 342 joints, 218 underwent surgery. In the postoperative evaluation of animals, those with grade IV luxation showed higher claudicating frequency. The patellar luxation mainly affects females, and the bilateral congenital luxation is the most common occurrence, and young and small animals are more likely to have it. Functional recovery postoperative luxation in grade IV is slow and partial.

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Avaliaram-se, por meio de estudo retrospectivo, o perfil epidemiológico, os sinais clínicos, as técnicas cirúrgicas utilizadas e a recuperação de cães apresentados para tratamento de luxação de patela no Hospital Veterinário da UFMG, no período de 2000 a 2010. Utilizaram-se as fichas clínico-cirúrgicas dos cães e registraram-se os dados referentes a cada animal. Foram estudadas 342 articulações nos registros de 210 animais. A luxação medial congênita bilateral foi a apresentação mais frequente, e as fêmeas foram mais acometidas. A idade dos animais variou de 32 dias a 16 anos, com maior ocorrência da luxação nos animais com até um ano de idade e massa corporal inferior a 9,1kg. Em 11,7% dos membros, a luxação era de grau I, em 39,8% grau II, em 20,5% grau III e em 28% grau IV. A frequência de claudicação pré-operatória foi maior nos cães com luxações graus III e IV. Das 342 articulações, 218 foram submetidas à cirurgia. Na avaliação pós-operatória, os animais com luxação grau IV mostraram maior frequência de claudicação. A luxação patelar acomete principalmente fêmeas, sendo a luxação congênita bilateral a apresentação mais comum, e animais jovens e de pequeno porte são mais susceptíveis. A recuperação funcional pós-operatória nas luxações grau IV é lenta e parcial.(AU)

The epidemiological profile, clinical signs, and surgical techniques used and the recovery of dogs presented for treatment of patellar luxation in the Veterinary Hospital of UFMG in the period from 2000 to 2010 were evaluated through a retrospective study. The clinical and surgical records of dogs and the data recorded for each animal were used. 342 joints in the records of 210 animals were studied. The congenital bilateral medial luxation was the most frequent occurrence and females were more affected. The age of the animals ranged from 32 days to 16 years, with higher incidence of luxation in animals under one year of age and body mass below 9.1kg. In 11.7% of the members had grade I luxation, 39.8% were grade II, 20.5% were grade III and 28% were grade IV. The frequency of preoperative claudicating was higher in dogs with luxation grades III and IV. Of the 342 joints, 218 underwent surgery. In the postoperative evaluation of animals, those with grade IV luxation showed higher claudicating frequency. The patellar luxation mainly affects females, and the bilateral congenital luxation is the most common occurrence, and young and small animals are more likely to have it. Functional recovery postoperative luxation in grade IV is slow and partial.(AU)

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We study black hole formation during the gravitational collapse of a massless scalar field in asymptotically D-dimensional anti-de Sitter AdS(D) spacetimes for D = 4, 5. We conclude that spherically symmetric gravitational collapse in asymptotically AdS spaces is turbulent and characterized by a Kolmogorov-Zakharov spectrum. Namely, we find that after an initial period of weakly nonlinear evolution, there is a regime where the power spectrum of the Ricci scalar evolves as ω(-s) with the frequency, ω, and s ≈ 1.7 ± 0.1.

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In this work it was investigated the microemulsion formation using impedance spectroscopy analysis. The results indicated that the microemulsion formation is clearly observed on the impedance complex plane. The phase transition related with microemulsion formation is characterized by a time relaxation distribution. In the condition of the microemulsion formation, the impedance spectra are characterized by a single relaxation time.

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Avaliou-se mecanicamente o compósito de poli-hidroxibutirato 70 por cento e hidroxiapatita 30 por cento na forma de placas para fixação óssea. Foram utilizadas 15 placas do compósito com 60mm de comprimento por 10mm de largura e espessura variando de 3mm no centro a 5mm nas extremidades, com seis orifícios. As placas foram fixadas em um modelo acrílico de fêmur de gato, e o conjunto foi submetido aos testes de flexão com quatro pontos, compressão axial e torção, empregando-se como referência microplacas de aço ASTM-F138 2,0mm. As médias das forças máximas nos testes de flexão e de compressão foram, respectivamente, de 323,20N e 617,70N, para as placas de compósito, e de 352,33N e 547,70N, para as placa de aço. No teste de torção, as médias dos torques máximos foram de 1,01Nm para as placas de compósito e de 1,15Nm para as placas de aço. Não houve diferença estatística entre as placas de compósito e de aço. O comportamento físico do material foi diferente, pois as placas de compósito se romperam e as de aço apenas se deformaram, revelando baixa ductilidade das placas de compósito.

Fixation bone plates made of 70 percent polyhydroxybutyrate and 30 percent hydroxyapatite composite were mechanically evaluated. The fifteen composite plates employed presented six holes and measured 60 x 10mm, length and width, respectively, with thickness ranging from 3 to 5mm according to the region. The plates were fixed in acrylic models of cat femur, then were subjected to tests of four-points bending, axial compression, and torsion, using as reference 2mm stainless steel plates. The means of the maximum force in flexion and compression tests were, respectively, 323.20N and 617,70N for the composite plates and 352.33N and 547.70N for the steel plates. In the torsional test, the means of torque were 1.01Nm for the composite plates and 1.15Nm for steel plates. There were no statistical differences between the plates of composite and steel. The physical behavior of the material was different once the composite plates broke up while the stainless steel ones only presented deformation, revealing the low ductility of the composite plates.

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Avaliou-se mecanicamente o compósito de poli-hidroxibutirato 70 por cento e hidroxiapatita 30 por cento na forma de placas para fixação óssea. Foram utilizadas 15 placas do compósito com 60mm de comprimento por 10mm de largura e espessura variando de 3mm no centro a 5mm nas extremidades, com seis orifícios. As placas foram fixadas em um modelo acrílico de fêmur de gato, e o conjunto foi submetido aos testes de flexão com quatro pontos, compressão axial e torção, empregando-se como referência microplacas de aço ASTM-F138 2,0mm. As médias das forças máximas nos testes de flexão e de compressão foram, respectivamente, de 323,20N e 617,70N, para as placas de compósito, e de 352,33N e 547,70N, para as placa de aço. No teste de torção, as médias dos torques máximos foram de 1,01Nm para as placas de compósito e de 1,15Nm para as placas de aço. Não houve diferença estatística entre as placas de compósito e de aço. O comportamento físico do material foi diferente, pois as placas de compósito se romperam e as de aço apenas se deformaram, revelando baixa ductilidade das placas de compósito.(AU)

Fixation bone plates made of 70 percent polyhydroxybutyrate and 30 percent hydroxyapatite composite were mechanically evaluated. The fifteen composite plates employed presented six holes and measured 60 x 10mm, length and width, respectively, with thickness ranging from 3 to 5mm according to the region. The plates were fixed in acrylic models of cat femur, then were subjected to tests of four-points bending, axial compression, and torsion, using as reference 2mm stainless steel plates. The means of the maximum force in flexion and compression tests were, respectively, 323.20N and 617,70N for the composite plates and 352.33N and 547.70N for the steel plates. In the torsional test, the means of torque were 1.01Nm for the composite plates and 1.15Nm for steel plates. There were no statistical differences between the plates of composite and steel. The physical behavior of the material was different once the composite plates broke up while the stainless steel ones only presented deformation, revealing the low ductility of the composite plates.(AU)

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Avaliou-se o compósito de poli-hidroxibutirado (PHB) 70 por cento e hidroxiapatita (HA) 30 por cento na forma de placas para fixação óssea em gatos. Foram usadas placas do compósito com 60mm de comprimento por 10mm de largura e espessura variando de 3mm no centro a 5mm nas extremidades, com seis orifícios. A placa do compósito foi empregada na fixação de osteotomia de fêmur em quatro gatos, totalizando seis intervenções. Verificou-se a ruptura de cinco placas (83,3 por cento) até o quarto dia e de uma placa (16,7 por cento) aos 21 dias, quando se observou um calo ósseo exuberante. O resultado da implantação da placa no gato mostrou que o compósito não possui resistência suficiente para ser empregado como placas de fixação de fêmur em gatos.

The composite of polyhydroxybutyrate (PHB) 70 percent and hydroxyapatite (HA) 30 percent was evaluated as plate for bone fixation in cats. The employed composite plates presented six orifices and measured 60 x 10mm, length and width, respectively, with thickness ranging from 3 to 5mm according to the region. The composite plate was used in the fixation of femoral osteotomy in four cats, in a total of six interventions. There were ruptures in five plates (83.3 percent) until day 4 and in one plate (16.7 percent) on the day 21, when it was possible to observe an exuberant osseous callus. The result of the plate deployment in the cat showed that the composite does not have sufficient strength to be used as plate of femoral fixation in cats.

Asunto(s)

RESUMEN

Avaliou-se o compósito de poli-hidroxibutirado (PHB) 70 por cento e hidroxiapatita (HA) 30 por cento na forma de placas para fixação óssea em gatos. Foram usadas placas do compósito com 60mm de comprimento por 10mm de largura e espessura variando de 3mm no centro a 5mm nas extremidades, com seis orifícios. A placa do compósito foi empregada na fixação de osteotomia de fêmur em quatro gatos, totalizando seis intervenções. Verificou-se a ruptura de cinco placas (83,3 por cento) até o quarto dia e de uma placa (16,7 por cento) aos 21 dias, quando se observou um calo ósseo exuberante. O resultado da implantação da placa no gato mostrou que o compósito não possui resistência suficiente para ser empregado como placas de fixação de fêmur em gatos.(AU)

The composite of polyhydroxybutyrate (PHB) 70 percent and hydroxyapatite (HA) 30 percent was evaluated as plate for bone fixation in cats. The employed composite plates presented six orifices and measured 60 x 10mm, length and width, respectively, with thickness ranging from 3 to 5mm according to the region. The composite plate was used in the fixation of femoral osteotomy in four cats, in a total of six interventions. There were ruptures in five plates (83.3 percent) until day 4 and in one plate (16.7 percent) on the day 21, when it was possible to observe an exuberant osseous callus. The result of the plate deployment in the cat showed that the composite does not have sufficient strength to be used as plate of femoral fixation in cats.(AU)

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RESUMEN

A physico-chemical analysis of metronidazole-Eudragit copolymers L100 and RLPO (a cationic polymeric matrix with an electrophilic character) was carried out in order to explore the drug-polymer interaction and its possible effects on the encapsulation and release profiles. An oil-in-oil encapsulation procedure was designed to obtain more intimate drug-matrix mixtures and to obtain a better insight into the details of the interaction. The encapsulation efficiency obtained in these cases was high (in the range of 85-95%), but the release rates were quite rapid. Solubility and interaction between metronidazole and copolymers are discussed in detail with a view to explaining the results. Amphiphilic block copolymers of poly(ethylene)-b-(polyethylene oxide) (20, 50 and 80% PEO) were tested as a matrix for metronidazole release in order to improve drug profiles. The performance of RLPO as the matrix for drug release was improved by blending it with amphiphilic block copolymer poly(ethylene)-b-(polyethylene oxide) (20% PEO). The release mechanism of metronidazole is governed mainly by the swelling of RLPO, yielding a better fit with the second-order Schott equation.

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