• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 14
  • 1
  • Tagged with
  • 18
  • 18
  • 12
  • 12
  • 12
  • 12
  • 10
  • 6
  • 4
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Efeitos do ultra-som pulsado de baixa intensidade em um modelo ósseo de ratas ovarectomizadas analisados por meio do ensaio de flexo-compressão / Low-intensity pulsed ultrasound effects on a bone pattern of ovariectomized female rats analyzed through flexion-compression test

Kodama, Ana Cristina 10 November 2003 (has links)
O osso é um tecido dinâmico que remodela em resposta a um estímulo mecânico aplicado. O ultra-som pulsado de baixa intensidade consiste da propagação de ondas de energia mecânica e o propósito desta investigação foi analisar seus efeitos em um modelo ósseo de ratas ovarectomizadas por meio do ensaio de flexo-compressão. O estudo foi composto por 28 ratas Wistar, com peso médio de 251,4 gramas. Os animais foram divididos em 3 grupos: 10 animais ovarectomizados, tratados com ultra-som (grupo tratado), 9 animais ovarectomizados para controle (grupo ovarectomizado) e 9 animais intactos que não sofreram nenhum tipo de intervenção (grupo intacto). No grupo tratado as aplicações do ultra-som foram iniciadas no primeiro dia após a cirurgia de ovarectomia, extendendo-se por 9 semanas, 6 dias por semana, durante 20 minutos diários. Por meio do ensaio de flexo-compressão, realizado na extremidade proximal dos fêmures, foi avaliado o limite máximo. A deformação do limite máximo não foi alterada nos diferentes grupos. No entanto, a média da carga do limite máximo do grupo ovarectomizado foi significativamente menor quando comparada com os grupos intacto e tratado, e entre os grupos intacto e tratado as médias não foram estatisticamente diferentes, sugerindo que apesar do grupo tratado também ter sido submetido à ovarectomia, a média da carga do limite máximo foi semelhante à do grupo intacto pela influência do ultra-som. Estes resultados fornecem indícios de que a perda de massa óssea provocou diminuição da carga do limite máximo e que a estimulação com ultra-som pulsado de baixa intensidade em fêmures de ratas ovarectomizadas contribuiu na preservação deste parâmetro mecânico / Bone is a dynamic tissue, which remodels to applied mechanical stimuli. The low-intensity pulsed ultrasound consists on the propagation of waves of mechanical energy and the motivation of this study was to analyze its effects on a ovariectomized female rat bone model through flexion-compression test. The study was carried out with 28 female Wistar rats with 251,4 grams average weight. The animals were divided in 3 groups: 10 ovariectomized rats exposed to ultrasound (treated animals), 9 control ovariectomized animals (ovariectomized group) and 9 intact animals that did not suffer any kind of intervention (intact group). In the treated group, the ultrasound exposition was initiated on the first day after the surgery, and it was extended for 9 weeks, 6 days per week, during 20 minutes per day. Through the flexion-compression test, carried out on the femur’s proximal extremity, the maximum limit was evaluated. The maximum limit deformation wasn’t altered in these different groups. Though, the maximum limit load average in the ovariectomized group was significantly lower when compared to the intact and treated groups, and between the intact and treated groups, the average wasn’t statistically different, suggesting that despite of the treated group was submitted to ovariectomy, the average value of the load maximum limit was similar to the intact group by the ultrasound influence. These results were indications that the loss of bone mass caused the load maximum limit decreasing and that the low-intensity pulsed ultrasound stimulation on femurs of ovariectomized female rats contributed to the preservation of this mechanical parameter
2

Efeito do ultra-som de baixa intensidade no colágeno da pele sadia de ratos / The effects of a low intensity ultrasound on health rat skin

Visnardi, Ana Rosa 11 September 2007 (has links)
O ultra-som de baixa intensidade é um recurso que vem sendo explorado em vários tipos de tecidos, inclusive a pele, porém os estudos buscam resultados em pele em reparação. Este estudo tem a finalidade de avaliar a eficáia do ultra-som de baixa intensidade no colágeno da pele sadia de ratos, visando analisar o comportamento das fibras de colágeno da derme, por meio da birrefringência e da análise histológica. Foi utilizado um aparelho de ultra-som de 30 mW/\'CM POT.2\' (SATA), modo pulsado, com frequência de 1,5 MHz, largura de pulso de 200 milisegundos. Os animais utilizados foram 15 ratos e divididos aleatoriamente em 3 grupos (5 animais cada): grupo Ultra-som (US), tratado com ultra-som; grupo Placebo (PL), submetido à irradiação simulada; e grupo Controle (C). A irradiação foi aplicada na pele do dorso dos animais durante 10 minutos, em 10 aplicações consecutivas com intervalo de 2 dias após a quinta aplicação. Amostras da pele dos animais foram submetidas à análise de birrefringência com microscopia de luz polarizada, através de medidas de retardo óptico (RO) e à análise histológica. As medidas de RO foram submetidas à análise estatística por meio do teste de variância Anova, com nível de significância de 5%, e ao teste de Tukey. O grupo US apresentou a menor média de RO (26,03), comparando com os grupos C (31,09) e PL (29,07) e as diferenças entre as médias foram significativas (p<0,01). Estes dados demonstram que a ação do ultra-som de baixa intensidade altera o comportamento das fibras de colágeno, causando uma desorganização das fibras uma vez que quanto maior o RO, maior a organização das fibras de colágeno. Analisando as medidas separadamente para cada camada da pele observa-se que a derme papilar e a derme reticular não apresentaram o mesmo comportamento. A ação do ultra-som mostrou-se mais acentuada na camada reticular, pois esta apresentou o menor valor de média de RO (22,51). Os dados do grupo PL demonstraram que há uma ação da irradiação simulada, porém não na mesma intensidade que a do grupo US. Nas áreas adjacentes à superfície da pele irradiada, não houve ação do ultra-som, pois as médias de RO não foram diferentes estatisticamente do grupo C. Na análise histológica pode observar as fibras de colágeno do grupo US com aspecto mais compacto em relação aos demais grupos, porém num nível moderado. Conclui-se que o ultra-som de baixa intensidade, nas condições deste estudo, altera a organização das fibras de colágeno na derme, de maneira mais acentuada na camada reticular, promovendo uma desorganização das fibras. / The low intensity ultrasound is a resource that is been explored over many different kinds of tissues, including skin. However, most studies attempt only to the skin healing process. The objective of this study was to evaluate the behavior of collagen fibers in the derm when exposed to the low intensity ultrasound through birefringence and histological analysis. The ultrasound equipment used had 30 mW/\'CM POT.2\' (SATA) pulsing model, frequency of 1.5 MHz and pulse width of 200 milliseconds. The 15 wistar rats used during the experiment were randomly divided into 3 distinct groups of 5 specimens each. The ultrasound group (US) was exposed to ultrasound; the placebo group (PL) was exposed to simulated ultrasound and the control group (C), with no exposition. The ultrasound irradiation was applied on the dorsal skin portion of the body for 10 minutes/day with two days rest between the sections after the fifth of the ten programmed sections. Skin samples collected were them submitted to a birefringence analysis under the polarized light microscopy and measured the optical delays (RO) as well as to a histological analysis. The optical delay (RO) analyses were them statistically analyzed under the ANOVA variance with 5% significance level and to the Tukey test. The statistical analyses demonstrated that the ultrasound group (US) had the lowest average of optical delay (RO) of the tested specimens (26.03) when compared with to control group (31.09) and the Placebo group (29.07) and the statistical difference between the series averages were significant (p<0.01). The data demonstrates that the low intensity ultrasound changes the behavior of the collagen fibers generating a disorganization of the fibers arrangement based on the concept that higher optical delay indicates a higher collagen fiber organization. Analyzing each individual skin layer was possible to see that papilar derm and reticular derm have the same behavior. The ultrasound action was more visible on the reticular derm were the optical delay average was 22.51. The placebo group also demonstrated that the simulated radiation had some effect over the area; however its level was lower than the ultrasound group. The skin surrounding the irradiated patch showed no change in behavior this fact was confirmed by the statistical analyses which matched the control group optical delay averages. The histological analyses allowed to see a more compacted collagen aspect on the ultrasound group than the observed on the other groups. Low intensity ultrasound, following this study conditions, changes the collagen fiber structure of the derm, presenting high intensity disorganization on the reticular layer.
3

Artrodese atlanto-axial em cães tratada por ultra-som de baixa intensidade / The atlanto-axial arthrodeses in dogs treated by low intensity ultrasound

Gama, Luiz Otavio Rosa 11 July 2002 (has links)
Neste estudo investigou-se em um modelo animal canino os efeitos do ultra-som de baixa intensidade na artrodese atlanto-axial com fixação metálica através do uso de parafusos compressivos. A investigação foi motivada pelos efeitos deste tratamento não-invasivo na consolidação óssea de fraturas recentes, com retardo de consolidação ou não-união (psedoartrose). A investigação foi realizada no segmento C1/C2 por este apresentar um elevado grau de mobilidade articular, quando em comparação com qualquer outra unidade motora da coluna vertebral. A artrodese foi realizada decorticando-se as faces articulares entre as duas primeiras vértebras cervicais para colocação de enxerto ósseo autólogo, coletado da cabeça do úmero. Após esse procedimento as vértebras foram fixadas por dois parafusos compressivos, colocados bilateralmente. Foram estabelecidos 2 grupos de estudo, sendo um de artrodeses tratadas por ultra-som de baixa intensidade (n=5) e outro de artrodeses não tratadas por ultra-som de baixa intensidade (n=3). O tempo do experimento para os animais de ambos os grupos foi de 60 dias após a cirurgia. Foram mantidos os parâmetros do ultra-som usado no tratamento de fraturas, mas a intensidade foi ligeiramente maior (38.17 2.66 mW/cm2). Os valores médio do grau de consolidação e da densidade mineral óssea (g/cm 2 ) nas artrodeses tratadas por ultra-som em comparação com as não tratadas foram 50% (p=0.002) e 29.3% (p=0.001) maiores, respectivamente. A apalpação manual das artrodese constatou 4 fusões sólidas e 1 fusão incompleta nos animais com artrodese tratada por ultra-som, e 3 fusões incompletas, ou seja, com a presença de movimento interarticular, nos animais com artrodese não tratada por ultra-som. / This study investigated the effect of low intensity ultrasound in spinal arthrodesis of the atlanto-axial vertebrae using dog as the animal model. The motivation for the investigation were the results of the same energy for treating fresh fractures, delayed union and non-unions. Eight mongrel dogs were randomly assigned to each of the two groups (treated and control) to undergo spinal fusion using compressive screws and autologous bone from the humerus. The vertebrae joint was decorticated before the bone graft. A specially designed constraint was used to focus the ultrasound over the dogs spine (treated group) 20 minutes per day. The animals were killed at 60 days for radiological, bone mineral density and manual palpation testing. The ultrasound parameters were the same used for treating fractures but the intensity was lightly higher (38.17 2.66 mW/cm2). The average value of the healing grade and the bone mineral density (g/cm2) were 50% (p=0.002) and 29.3% (p=0.001) higher in the arthrodesis treated by ultrasound, respectively. The manual palpation of the fusion sites indicated 4 solidly fused and 1 incomplete fusion in the arthrodesis treated by ultrasound.
4

EFFECT OF UV-C LIGHT, HIGH INTENSITY ULTRASOUND AND NONTHERMAL ATMOSPHERIC PLASMA TREATMENTS ON THE ALLERGENICITY OF MAJOR COW MILK PROTEINS

Tammineedi, Chatrapati Veera Raghava Kumar 01 August 2012 (has links)
Milk is one of the eight major food allergens. Cow's milk allergy is the most common allergy in children under 2 years of age. About 1.6 to 2.8 percent of children under this age are reported to have cow's milk allergy. Casein, β-lactoglobulin and α-lactalbumin are major milk protein allergens. Nonthermal treatments like high intensity ultrasound, ultraviolet (UV) light and nonthermal plasma treatments have been reported in the literature to be effective in reducing the allergenicity of different food proteins. Hence it was expected for these treatments to reduce cow milk allergenicity. The objective of this study was to investigate the effect of high intensity ultrasound, nonthermal atmospheric plasma and UV-C light treatments in reducing the allergenicity of isolated major milk proteins. Sonics Vibracell VC 505 ultrasonic liquid processor was used to perform high intensity ultrasound treatments. UV light treatments were performed using a DDK Scientific Corporation UV tunnel. A nonthermal atmospheric plasma setup assembled in Department of Microbiology lab was used to perform plasma treatments. Samples were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to estimate the change in protein concentration and enzyme linked immuno sorbent assays (ELISA) to observe the change in IgE binding. A one-way analysis of variance was conducted to evaluate the relationship between treatment time and percent IgE binding at 95% confidence level. Further investigation was conducted with nuclear magnetic resonance (NMR) spectroscopy on treated casein to assess any change in the structure of protein. SDS-PAGE results for ultrasound and plasma treatments didn't show any change in gel band intensities for casein, β-lactoglobulin and α-lactalbumin indicating no significant change in protein concentration. Ci-ELISA analysis showed that there was no significant difference (p>0.05) in IgE binding values for control and treated samples in ultrasound and plasma treatment conditions tested in this study. The intensities of all the three protein bands in SDS-PAGE gel were reduced by UV-C light treatment at 15 min treatment time. In Ci-ELISA, there was a significant difference (p< 0.05) in IgE binding values for control and treated samples and a reduction in allergenicity of proteins (25% reduction for casein and 28% reduction for whey protein fractions) was observed. Further investigations using in vivo clinical trials need to be conducted to confirm this result. NMR results didn't show any noticeable changes in the structures of casein with all three different treatments. In conclusion, UV-C light treatment can reduce the allergenicity of isolated major milk proteins to some extent. High intensity ultrasound and nonthermal atmospheric plasma treatments failed to generate effective results for reducing allergenicity at the conditions tested in this study. Higher intensity and longer treatment conditions might yield better results with ultrasound treatment. Different power and gas flow rates used to generate plasma with direct exposure of proteins might yield better results towards reducing the allergenicity of major milk allergens.
5

Efeito do ultra-som de baixa intensidade no colágeno da pele sadia de ratos / The effects of a low intensity ultrasound on health rat skin

Ana Rosa Visnardi 11 September 2007 (has links)
O ultra-som de baixa intensidade é um recurso que vem sendo explorado em vários tipos de tecidos, inclusive a pele, porém os estudos buscam resultados em pele em reparação. Este estudo tem a finalidade de avaliar a eficáia do ultra-som de baixa intensidade no colágeno da pele sadia de ratos, visando analisar o comportamento das fibras de colágeno da derme, por meio da birrefringência e da análise histológica. Foi utilizado um aparelho de ultra-som de 30 mW/\'CM POT.2\' (SATA), modo pulsado, com frequência de 1,5 MHz, largura de pulso de 200 milisegundos. Os animais utilizados foram 15 ratos e divididos aleatoriamente em 3 grupos (5 animais cada): grupo Ultra-som (US), tratado com ultra-som; grupo Placebo (PL), submetido à irradiação simulada; e grupo Controle (C). A irradiação foi aplicada na pele do dorso dos animais durante 10 minutos, em 10 aplicações consecutivas com intervalo de 2 dias após a quinta aplicação. Amostras da pele dos animais foram submetidas à análise de birrefringência com microscopia de luz polarizada, através de medidas de retardo óptico (RO) e à análise histológica. As medidas de RO foram submetidas à análise estatística por meio do teste de variância Anova, com nível de significância de 5%, e ao teste de Tukey. O grupo US apresentou a menor média de RO (26,03), comparando com os grupos C (31,09) e PL (29,07) e as diferenças entre as médias foram significativas (p<0,01). Estes dados demonstram que a ação do ultra-som de baixa intensidade altera o comportamento das fibras de colágeno, causando uma desorganização das fibras uma vez que quanto maior o RO, maior a organização das fibras de colágeno. Analisando as medidas separadamente para cada camada da pele observa-se que a derme papilar e a derme reticular não apresentaram o mesmo comportamento. A ação do ultra-som mostrou-se mais acentuada na camada reticular, pois esta apresentou o menor valor de média de RO (22,51). Os dados do grupo PL demonstraram que há uma ação da irradiação simulada, porém não na mesma intensidade que a do grupo US. Nas áreas adjacentes à superfície da pele irradiada, não houve ação do ultra-som, pois as médias de RO não foram diferentes estatisticamente do grupo C. Na análise histológica pode observar as fibras de colágeno do grupo US com aspecto mais compacto em relação aos demais grupos, porém num nível moderado. Conclui-se que o ultra-som de baixa intensidade, nas condições deste estudo, altera a organização das fibras de colágeno na derme, de maneira mais acentuada na camada reticular, promovendo uma desorganização das fibras. / The low intensity ultrasound is a resource that is been explored over many different kinds of tissues, including skin. However, most studies attempt only to the skin healing process. The objective of this study was to evaluate the behavior of collagen fibers in the derm when exposed to the low intensity ultrasound through birefringence and histological analysis. The ultrasound equipment used had 30 mW/\'CM POT.2\' (SATA) pulsing model, frequency of 1.5 MHz and pulse width of 200 milliseconds. The 15 wistar rats used during the experiment were randomly divided into 3 distinct groups of 5 specimens each. The ultrasound group (US) was exposed to ultrasound; the placebo group (PL) was exposed to simulated ultrasound and the control group (C), with no exposition. The ultrasound irradiation was applied on the dorsal skin portion of the body for 10 minutes/day with two days rest between the sections after the fifth of the ten programmed sections. Skin samples collected were them submitted to a birefringence analysis under the polarized light microscopy and measured the optical delays (RO) as well as to a histological analysis. The optical delay (RO) analyses were them statistically analyzed under the ANOVA variance with 5% significance level and to the Tukey test. The statistical analyses demonstrated that the ultrasound group (US) had the lowest average of optical delay (RO) of the tested specimens (26.03) when compared with to control group (31.09) and the Placebo group (29.07) and the statistical difference between the series averages were significant (p<0.01). The data demonstrates that the low intensity ultrasound changes the behavior of the collagen fibers generating a disorganization of the fibers arrangement based on the concept that higher optical delay indicates a higher collagen fiber organization. Analyzing each individual skin layer was possible to see that papilar derm and reticular derm have the same behavior. The ultrasound action was more visible on the reticular derm were the optical delay average was 22.51. The placebo group also demonstrated that the simulated radiation had some effect over the area; however its level was lower than the ultrasound group. The skin surrounding the irradiated patch showed no change in behavior this fact was confirmed by the statistical analyses which matched the control group optical delay averages. The histological analyses allowed to see a more compacted collagen aspect on the ultrasound group than the observed on the other groups. Low intensity ultrasound, following this study conditions, changes the collagen fiber structure of the derm, presenting high intensity disorganization on the reticular layer.
6

Artrodese atlanto-axial em cães tratada por ultra-som de baixa intensidade / The atlanto-axial arthrodeses in dogs treated by low intensity ultrasound

Luiz Otavio Rosa Gama 11 July 2002 (has links)
Neste estudo investigou-se em um modelo animal canino os efeitos do ultra-som de baixa intensidade na artrodese atlanto-axial com fixação metálica através do uso de parafusos compressivos. A investigação foi motivada pelos efeitos deste tratamento não-invasivo na consolidação óssea de fraturas recentes, com retardo de consolidação ou não-união (psedoartrose). A investigação foi realizada no segmento C1/C2 por este apresentar um elevado grau de mobilidade articular, quando em comparação com qualquer outra unidade motora da coluna vertebral. A artrodese foi realizada decorticando-se as faces articulares entre as duas primeiras vértebras cervicais para colocação de enxerto ósseo autólogo, coletado da cabeça do úmero. Após esse procedimento as vértebras foram fixadas por dois parafusos compressivos, colocados bilateralmente. Foram estabelecidos 2 grupos de estudo, sendo um de artrodeses tratadas por ultra-som de baixa intensidade (n=5) e outro de artrodeses não tratadas por ultra-som de baixa intensidade (n=3). O tempo do experimento para os animais de ambos os grupos foi de 60 dias após a cirurgia. Foram mantidos os parâmetros do ultra-som usado no tratamento de fraturas, mas a intensidade foi ligeiramente maior (38.17 2.66 mW/cm2). Os valores médio do grau de consolidação e da densidade mineral óssea (g/cm 2 ) nas artrodeses tratadas por ultra-som em comparação com as não tratadas foram 50% (p=0.002) e 29.3% (p=0.001) maiores, respectivamente. A apalpação manual das artrodese constatou 4 fusões sólidas e 1 fusão incompleta nos animais com artrodese tratada por ultra-som, e 3 fusões incompletas, ou seja, com a presença de movimento interarticular, nos animais com artrodese não tratada por ultra-som. / This study investigated the effect of low intensity ultrasound in spinal arthrodesis of the atlanto-axial vertebrae using dog as the animal model. The motivation for the investigation were the results of the same energy for treating fresh fractures, delayed union and non-unions. Eight mongrel dogs were randomly assigned to each of the two groups (treated and control) to undergo spinal fusion using compressive screws and autologous bone from the humerus. The vertebrae joint was decorticated before the bone graft. A specially designed constraint was used to focus the ultrasound over the dogs spine (treated group) 20 minutes per day. The animals were killed at 60 days for radiological, bone mineral density and manual palpation testing. The ultrasound parameters were the same used for treating fractures but the intensity was lightly higher (38.17 2.66 mW/cm2). The average value of the healing grade and the bone mineral density (g/cm2) were 50% (p=0.002) and 29.3% (p=0.001) higher in the arthrodesis treated by ultrasound, respectively. The manual palpation of the fusion sites indicated 4 solidly fused and 1 incomplete fusion in the arthrodesis treated by ultrasound.
7

Efeitos do ultra-som pulsado de baixa intensidade em um modelo ósseo de ratas ovarectomizadas analisados por meio do ensaio de flexo-compressão / Low-intensity pulsed ultrasound effects on a bone pattern of ovariectomized female rats analyzed through flexion-compression test

Ana Cristina Kodama 10 November 2003 (has links)
O osso é um tecido dinâmico que remodela em resposta a um estímulo mecânico aplicado. O ultra-som pulsado de baixa intensidade consiste da propagação de ondas de energia mecânica e o propósito desta investigação foi analisar seus efeitos em um modelo ósseo de ratas ovarectomizadas por meio do ensaio de flexo-compressão. O estudo foi composto por 28 ratas Wistar, com peso médio de 251,4 gramas. Os animais foram divididos em 3 grupos: 10 animais ovarectomizados, tratados com ultra-som (grupo tratado), 9 animais ovarectomizados para controle (grupo ovarectomizado) e 9 animais intactos que não sofreram nenhum tipo de intervenção (grupo intacto). No grupo tratado as aplicações do ultra-som foram iniciadas no primeiro dia após a cirurgia de ovarectomia, extendendo-se por 9 semanas, 6 dias por semana, durante 20 minutos diários. Por meio do ensaio de flexo-compressão, realizado na extremidade proximal dos fêmures, foi avaliado o limite máximo. A deformação do limite máximo não foi alterada nos diferentes grupos. No entanto, a média da carga do limite máximo do grupo ovarectomizado foi significativamente menor quando comparada com os grupos intacto e tratado, e entre os grupos intacto e tratado as médias não foram estatisticamente diferentes, sugerindo que apesar do grupo tratado também ter sido submetido à ovarectomia, a média da carga do limite máximo foi semelhante à do grupo intacto pela influência do ultra-som. Estes resultados fornecem indícios de que a perda de massa óssea provocou diminuição da carga do limite máximo e que a estimulação com ultra-som pulsado de baixa intensidade em fêmures de ratas ovarectomizadas contribuiu na preservação deste parâmetro mecânico / Bone is a dynamic tissue, which remodels to applied mechanical stimuli. The low-intensity pulsed ultrasound consists on the propagation of waves of mechanical energy and the motivation of this study was to analyze its effects on a ovariectomized female rat bone model through flexion-compression test. The study was carried out with 28 female Wistar rats with 251,4 grams average weight. The animals were divided in 3 groups: 10 ovariectomized rats exposed to ultrasound (treated animals), 9 control ovariectomized animals (ovariectomized group) and 9 intact animals that did not suffer any kind of intervention (intact group). In the treated group, the ultrasound exposition was initiated on the first day after the surgery, and it was extended for 9 weeks, 6 days per week, during 20 minutes per day. Through the flexion-compression test, carried out on the femur’s proximal extremity, the maximum limit was evaluated. The maximum limit deformation wasn’t altered in these different groups. Though, the maximum limit load average in the ovariectomized group was significantly lower when compared to the intact and treated groups, and between the intact and treated groups, the average wasn’t statistically different, suggesting that despite of the treated group was submitted to ovariectomy, the average value of the load maximum limit was similar to the intact group by the ultrasound influence. These results were indications that the loss of bone mass caused the load maximum limit decreasing and that the low-intensity pulsed ultrasound stimulation on femurs of ovariectomized female rats contributed to the preservation of this mechanical parameter
8

Effect of High Intensity Ultrasound on the Crystallization Behavior of Interesterified Fats

Kadamne, Jeta Vijay 01 May 2018 (has links)
The process of partial hydrogenation produces trans fats and the fats that undergo this process are called partially hydrogenated fats (PHF). Clinical studies have shown a strong association between PHF and coronary heart diseases. In 2015 The U.S. Food and Drug Administration removed the Generally recognized as safe or "GRAS" status of PHF. These fats were used in confectionary, margarines, shortenings, doughnuts, cookies, cakes, etc. The PHF serve a function in food by providing a higher shelf life and a desired harder structure due to their higher melting point. Hence, the food industry is currently looking for PHF alternatives which serve the function but have no harmful health effects. One of the alternatives to replace PHF is to use interesterified fats that have a low level of saturation that makes them healthier. However, these new fats are too soft with restricted use in many food applications. In this study, we explored the use of high intensity ultrasound (HIU) to improve the functional properties of interesterified fats and make them harder. Our study showed that HIU formed small crystals in these fats and increased their viscosity. The results from this study on the flavor release from the interesterified fats showed that the physical structure and hence the amount of solid fat in the sample affected its flavor perception. The solid fats had higher flavor perception than the liquid fat samples. The goal of this study is to improve the functionality of the interesterified fats using HIU and understand the flavor release from these fats to make substitution in food products easier.
9

Influência da estimulação ultra-sônica de baixa intensidade no reparo de osteotomias de tíbias com fixação flexível / The influence of low-intensity ultrasound on the tibia osteomy healing of rabbits, with flexible fixation

Jorge, Fernando Augusto Jeronymo 17 September 2004 (has links)
O ultra-som de baixa intensidade tem demonstrado ser um recurso acelerador do processo de consolidação óssea em fraturas. Este estudo experimental investigou a influência da estimulação ultra-sônica de baixa intensidade no processo de reparo ósseo em fraturas de tíbias tratadas por meio de fixação flexível. O estudo foi desenvolvido no laboratório de Bioengenharia da FMRP da Universidade de São Paulo Campus de Ribeirão Preto, utilizando 20 coelhos machos adolescentes da raça Nova Zelândia, que foram submetidos a uma osteotomia no terço médio da tíbia e tratados com fixador externo unilateral. Após o procedimento cirúrgico os animais foram divididos em três grupos: controle com n = 7 (membro contralateral, não fixado), grupo controle lesão com n = 7 (fixados e mantidos em gaiolas) e grupo ultra-som com n = 7, que recebeu estimulação com equipamento de ultra-som de baixa intensidade (30mW/'CM POT.2') e ciclo de trabalho de 1/5. No final de 20 dias de tratamento suas tíbias foram retiradas e submetidas a ensaio mecânico de torção. Na avaliação das propriedades mecânicas torque máximo e rigidez, não foi observada diferença significativa (p '< OU =' 0,05) entre os grupos estimulados e controle lesão. Estes resultados sugerem que a estimulação ultra-sônica de baixa intensidade aplicada ao reparo de fraturas na presença de fixação flexível não influencia a velocidade e o padrão de consolidação da fratura / The low-intensity ultrasound has demonstrated to be an accelerator device on the process of recovering of bone fractures. This experimental study investigated the influence of the low-intensity ultrasound stimulation on the process of bone repairing of fractures of tibia treated with flexible fixator. The study was developed at the FMRP Bioengineering laboratory, of the University of Sao Paulo, campus of Ribeirao Preto, using 20 teenager male rabbits from the New Zealand breed which were subjected to an osteomy in the median third of the tibia and treated with an unilateral external fixator. After the surgical procedure the animals were divided into three groups: control with n = 7 (paw contralateral, not fixed), group control injury with n = 7 (fixed and kept in cages) and group ultrasound with n = 7, that received stimulation with low-intensity ultrasound equipment (30mW/'CM POT.2') and duty cycle 1/5. At the end of 20 days of treatment, their tibia were removed and subjected to a mechanical twist test. At the evaluation of the mechanical properties: maximum torque and hardness, it was not observed significant differences (p '< OU =' 0,05) among the stimulated groups and the control injury. These outcomes suggest that the low-intensity ultrasound applied for fractures healing in the presence of flexible fixation does not have influence on the velocity nor the standard of the fracture recovering
10

Factors Affecting the Oxidative Stability of Foods-Interesterified Soybean Oil with High Intensity Ultrasound Treatment and Trona Mineral in Packaged Fresh Meats

Lee, Jiwon 01 May 2013 (has links)
Oxidation in oils and muscle foods has been studied for many years to understand its mechanism and furthermore to control and manage it. A series of different processing steps or different packaging techniques can alter oxidative stability. The objective of the current study was to examine oxidative stability of processed oil and to evaluate the effect of carbon dioxide generating mineral on quality of beef and chicken under different storage conditions. In Study 1 (Chapter 3), the effect of ultrasound on oxidative stability of interesterified soybean oil and soybean oil was examined. Sonication did not affect oxidation rate until the oils were highly oxidized. Sonicated interesterified soybean oil exhibited a slightly but significantly lower oxidation rate than non-sonicated oil during long-term storage, while sonication of non-interesterified soybean oil led to a significantly higher oxidation rate than in non-sonicated soybean oil after induction period. In Study 2 (Chapter 4), the feasibility of trona as a CO2 producing product in a model system and in modified atmosphere packaging of beef steaks was investigated. Trona was able to generate more carbon dioxide than sodium bicarbonate with salicylic acid in model systems. Steaks stored with trona/acid mixture had similar color stability and delayed lipid oxidation compared to those stored in high oxygen packaging. In Study 3 (Chapter 5), the effect of packets containing trona and acid placed in a simulated self serve retail case and closed butcher case on the quality of ground beef was studied. Mineral packets did not affect color, lipid oxidation, or microbial growth of ground beef since there was not a sufficient amount of moisture to generate CO2 effectively. In Study 4 (Chapter 6), the quality of chicken breast/thigh portions stored with mineral packets was compared to those without mineral packets during extended storage, and mineral packets had an antimicrobial effect of CO2 only on day 15. In conclusion, high intensity ultrasound did not affect the rate of oxidation of oil until the oil had already become noticeably rancid, and mineral packets containing trona and an acid with low water solubility can be used as CO2 generating sachet if sufficient moisture is given.

Page generated in 0.1233 seconds