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  • 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

Responsive Polymer Composites: LLDPE and Phenolphtalein Disodium Blends

Asfour, fadi 08 1900 (has links)
<P> Responsive polymer composites were developed by incorporating a functional component into a nonpolar amorphous polymer. The response of the polymer composite is the change in color observed upon exposing the composite to different acids. One application could be a device to monitor the diffusion of different acids in different polymers. </p> <p> The research contained within this thesis deals with an investigation of basic properties of polymer composites. This was accomplished, first through the preparation of a composite of phenolphthalein disodium and Linear Low Density Polyethylene (LLDPE), second, by monitoring the decolorizing process and the aspects that affect it. The investigations included the extrusion parameters, types of acid, acid concentration and indicator concentration, and lastly by quantifying the process through the comparison of empricial diffusion coefficients and corresponding diffusion rates. </p> <p> This study has shown that decolorization occurs at a fast pace in the presence of acetic acid and slow in the presence of hydrochloric acid. Further as the indicator concentration increases, the decolorization process becomes slower. Techniques used to monitor the properties were Scanning Electron Microscopy (SEM) micrographs of freeze fractured composites, Differential Scanning Calorimetry (DSC) scans for the starting materials as well as the composites, and photography of the cross-sections of sample composite cylinders. </p> / Thesis / Master of Science (MSc)
2

The Effects of EDTA Chelation Therapy on Plaque Calcium and Mineral Metabolism in Atherosclerotic Rabbits

Walker, Foster M. 05 1900 (has links)
New Zealand albino rabbits exhibited calcified aortic plaques and maximum average serum cholesterol levels of 1200 mg percent after twenty-three weeks on an atherogenic diet (250 to 500 mg percent cholesterol in ten percent corn oil; 200,00 I.U. vitamin D3 per month). One month following termination of the atherogenic diet, rabbits were treated with disodium edetate (Na2EDTA, 50 mg/kg body weight) via the marginal ear vein, on alternating days for a total of twenty infusions each. Aortae were examined for tissue calcium both quantitatively (direct microcomplexometric analysis) and histologically six weeks after completion of EDTA chelation therapy.
3

Turnover do carbono (δ13C) em tecidos corporais e desempenho de leitões desmamados alimentados com dietas contendo nucleotídeos

Miassi, Gabriela de Mello. January 2016 (has links)
Orientador: Dirlei Antonio Berto / Resumo: Objetivou-se com este estudo avaliar a influência dos nucleotídeos (inosinato e guanilato dissódico) sobre o desempenho, peso relativo e turnover do 13C no intestino delgado, baço, fígado e pâncreas de leitões desmamados com idade média de 21 dias. Foram avaliados os seguintes tratamentos: dieta controle sem suplementação de nucleotídeos (Nu); dietas contendo 0,2% de Nu; 0,4% de Nu e 0,6% de Nu. No primeiro experimento 84 leitões desmamados (6,04 ± 0,25 kg) foram distribuídos em um delineamento experimental em blocos ao acaso com quatro tratamentos (níveis de Nu), sete repetições e três animais por unidade experimental, para avaliação do desempenho. No segundo experimento foram utilizados 87 leitões desmamados (6,03 ± 0,23 kg) em delineamento experimental em blocos ao acaso, com os mesmos tratamentos, sendo abatidos três leitões no dia do desmame (dia zero) e três leitões por tratamento nos dias 3, 5, 8, 12, 23, 35 e 49 após o desmame, para avaliar o turnover do 13C na mucosa e na parede intestinal (duodeno e jejuno), no baço, fígado e pâncreas, e o peso relativo do intestino delgado e do baço, fígado e pâncreas. No primeiro experimento não foi verificado efeito dos tratamentos (P > 0,05) nas variáveis de desempenho dos leitões no período de 21 a 36 dias de idade. No período de 21 a 48 dias de idade dos leitões houve efeito quadrático (P < 0,01) dos níveis de Nu no consumo diário de ração e ganho diário de peso. No período experimental total (21 a 55 dias de idade dos leitões... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study was conducted to evaluate effects of dietary supplementation of nucleotide (disodium 5´guanylate and disodium 5´inosinate) on the growth performance, relative weight and carbon turnover 13C of the small intestine, spleen, liver and pancreas of weaned piglets of 21 days of age. The treatments were dietary supplementation with 0% (control); 0.2%; 0.4% or 0.6% nucleotide of diet. In the first trial eighty-four weaned piglets (6.04 ± 0.25 kg average initial BW) were allotted to four dietary treatments (Nu levels) with seven pens per treatment and three pigs per pen, in a randomized complete block design to evaluate the performance. In the second trial eighty-seven weaned piglets (6.03 ± 0.23 kg average initial BW) were used in a randomized complete block design, with the same treatments, and on the day of weaning (day zero) were slaughtered three piglets and days 3, 5, 8, 12, 23, 35 and 49 after weaning, three pigs per treatment were slaughtered, to evaluate the effect of nucleotide on the turnover 13C in the mucosa and intestinal wall (duodenum and jejunum), spleen, liver and pancreas and relative weight of the small intestine and spleen, liver and pancreas. During the first period (21 to 36 days of age), no differences were detected on the performance. During the second period (21 to 48 days of age), a quadratic effect (P < 0.01) of the levels of nucleotide was verified on average daily feed intake and average daily weight gain. During the whole experimental period ... (Complete abstract click electronic access below) / Doutor
4

Turnover do carbono (δ13C) em tecidos corporais e desempenho de leitões desmamados alimentados com dietas contendo nucleotídeos / Carbon turnover (δ13C) in body tissues and performance of weanling pigs fed diets containing nucleotide

Miassi, Gabriela de Mello [UNESP] 19 August 2016 (has links)
Submitted by GABRIELA DE MELLO MIASSI null (gabimello@zootecnista.com.br) on 2016-08-29T14:52:32Z No. of bitstreams: 1 Tese Gabriela de Mello Miassi.pdf: 1914149 bytes, checksum: 98cbbb91f9acc7240a628f9536a25065 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-08-30T17:36:58Z (GMT) No. of bitstreams: 1 miassi_gm_dr_bot.pdf: 1914149 bytes, checksum: 98cbbb91f9acc7240a628f9536a25065 (MD5) / Made available in DSpace on 2016-08-30T17:36:58Z (GMT). No. of bitstreams: 1 miassi_gm_dr_bot.pdf: 1914149 bytes, checksum: 98cbbb91f9acc7240a628f9536a25065 (MD5) Previous issue date: 2016-08-19 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Objetivou-se com este estudo avaliar a influência dos nucleotídeos (inosinato e guanilato dissódico) sobre o desempenho, peso relativo e turnover do 13C no intestino delgado, baço, fígado e pâncreas de leitões desmamados com idade média de 21 dias. Foram avaliados os seguintes tratamentos: dieta controle sem suplementação de nucleotídeos (Nu); dietas contendo 0,2% de Nu; 0,4% de Nu e 0,6% de Nu. No primeiro experimento 84 leitões desmamados (6,04 ± 0,25 kg) foram distribuídos em um delineamento experimental em blocos ao acaso com quatro tratamentos (níveis de Nu), sete repetições e três animais por unidade experimental, para avaliação do desempenho. No segundo experimento foram utilizados 87 leitões desmamados (6,03 ± 0,23 kg) em delineamento experimental em blocos ao acaso, com os mesmos tratamentos, sendo abatidos três leitões no dia do desmame (dia zero) e três leitões por tratamento nos dias 3, 5, 8, 12, 23, 35 e 49 após o desmame, para avaliar o turnover do 13C na mucosa e na parede intestinal (duodeno e jejuno), no baço, fígado e pâncreas, e o peso relativo do intestino delgado e do baço, fígado e pâncreas. No primeiro experimento não foi verificado efeito dos tratamentos (P > 0,05) nas variáveis de desempenho dos leitões no período de 21 a 36 dias de idade. No período de 21 a 48 dias de idade dos leitões houve efeito quadrático (P < 0,01) dos níveis de Nu no consumo diário de ração e ganho diário de peso. No período experimental total (21 a 55 dias de idade dos leitões) verificou-se efeito quadrático dos níveis de Nu no ganho diário de peso. No segundo experimento foram observadas diminuições da meia-vida do 13C para a mucosa e parede do duodeno nos animais que receberam dietas com 0,4% de Nu e para a mucosa e parede do jejuno naqueles alimentados com dietas com 0,2% de Nu. No 12º dia de abate houve efeito linear (P < 0,01) dos níveis de Nu no peso relativo do intestino delgado. Os valores da meia-vida do carbono foram para o baço de 19,5; 18,1; 18,4 e 17,1 dias, para o fígado de 10,4; 10,1; 10,1 e 11,3 dias, e para o pâncreas de 17,2; 14,6; 13,8 e 15,4 dias, respectivamente, para os leitões que receberam dietas com adição com 0%; 0,2%; 0,4% e 0,6% de Nu. Observou-se menores valores de meia-vida do baço, fígado e pâncreas dos animais que receberam dietas com adição de 0,6%; 0,2% e 0,4% de Nu, respectivamente. A suplementação de Nu na dieta de leitões melhora o desempenho e acelera o turnover do carbono da parede e mucosa intestinal, no baço fígado e pâncreas, sugerindo recuperação e crescimento mais rápido no período pós-desmame. / This study was conducted to evaluate effects of dietary supplementation of nucleotide (disodium 5´guanylate and disodium 5´inosinate) on the growth performance, relative weight and carbon turnover 13C of the small intestine, spleen, liver and pancreas of weaned piglets of 21 days of age. The treatments were dietary supplementation with 0% (control); 0.2%; 0.4% or 0.6% nucleotide of diet. In the first trial eighty-four weaned piglets (6.04 ± 0.25 kg average initial BW) were allotted to four dietary treatments (Nu levels) with seven pens per treatment and three pigs per pen, in a randomized complete block design to evaluate the performance. In the second trial eighty-seven weaned piglets (6.03 ± 0.23 kg average initial BW) were used in a randomized complete block design, with the same treatments, and on the day of weaning (day zero) were slaughtered three piglets and days 3, 5, 8, 12, 23, 35 and 49 after weaning, three pigs per treatment were slaughtered, to evaluate the effect of nucleotide on the turnover 13C in the mucosa and intestinal wall (duodenum and jejunum), spleen, liver and pancreas and relative weight of the small intestine and spleen, liver and pancreas. During the first period (21 to 36 days of age), no differences were detected on the performance. During the second period (21 to 48 days of age), a quadratic effect (P < 0.01) of the levels of nucleotide was verified on average daily feed intake and average daily weight gain. During the whole experimental period (21 to 55 days of age), there was a quadratic effect of the levels of nucleotide (P < 0.01) on average daily weight gain. In the second experiment were observed decrease half-life to the duodenum mucosal and wall in treatment 0.4% Nu and jejunum mucosa and wall in treatment 0.2% Nu and 12th day of slaughter there was a linear effect (P < 0.01) of Nu levels relative weight of the small intestine. The values of carbon half-life to the spleen were 19.5; 18.1; 18.4 and 17.1, to the liver were 10.4; 10.1; 10.1 and 11.3 day, to the pancreas were 17.2; 14.6; 13.8 and 15.4 day, respectively, for the piglets fed 0,0%; 0.2%; 0.4% and 0,6% de Nu, respectively. Lower values of half-life was observed to the spleen, liver and pancreas of animal were dietary supplementation with 0.6%, 0.2% and 0.4% Nu, respectively. The nucleotide supplementation in the diets of pigs improves performance and accelerates the carbon turnover of mucosa and intestinal wall, in the spleen, liver and pancreas suggesting a faster recovery and growth in the post-weaned period. / CNPq: 141843/2013-6 / FAPESP: 2013/17964-2
5

Effects of Soluble Calcium-to-Protein Ratio on Age Gelation of Ultra

Ryue, Je Hong 01 May 1994 (has links)
Reverse osmosis (RO) and ultrafiltration (UF) retentates were ultra-high temperature (UHT) processed and compared for storage life at room temperature. Viscosity studies indicated that UHT-treated, RO retentate delayed age gelation longer than UF retentate at the same total solids level (26% TS). When compared at 6.4% protein level (2x RO vs 2.7x UF where x=ratio of the feed volume to concentrate volume), the storage life for both RO and UF retentates was about 6 to 8 months. Sodium hexametaphosphate (SHMP) and disodium phosphate (DSP) at 1, 3, 5, 10, and 20 mM concentrations were incorporated prior to UHT processing of each sample to improve the shelf life. SHMP at 1 and 3 mM concentrations was effective in delaying age gelation, whereas all levels of DSP accelerated gelation. However, SHMP accelerated age gelation at concentrations of 10 and 20 mM. SHMP at 1 mM in RO retentate was more effective in delaying age gelation than the same SHMP level in two UF samples (22 and 26% TS). Analysis showed that RO/UHT-treated samples had higher soluble calcium and ionic calcium than did UF/UHT-treated samples. The coefficient of determination (R2) was .80 between soluble calcium-to-protein ratio and shelf life.
6

Influencia do cromoglicato de sodio no processo de necrose muscular em camundongos mdx jovens / Cromolyn therapy decreases dystrophic skeletal muscle necrosis

Machado, Rafael Ventura, 1977- 18 September 2006 (has links)
Orientadores: Maria Julia Marques, Elaine Minatel / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-07T06:25:49Z (GMT). No. of bitstreams: 1 Machado_RafaelVentura_M.pdf: 800859 bytes, checksum: 1bb3eb2604bb7183c771d752b2478081 (MD5) Previous issue date: 2006 / Resumo: Neste trabalho foi verificado se o cromoglicato de sódio protege os músculos distróficos de camundongos mdx da necrose. Camundongos mdx (n=8) com 14 dias de vida pós-natal, antes do início dos ciclos de degeneração e regeneração, foram tratados com cromoglicato de sódio (50mg/Kg/dia; intraperitoneal) por 16 dias. Camundongos mdx (n=8) com a mesma idade foram utilizados como grupo controle, recebendo salina pela mesma via e período. A necrose muscular foi quantificada através do marcador azul de Evans (AE), que penetra na fibra muscular somente quando há lesão do sarcolema. Secções do terço médio dos músculos esternomatóideo e tibial anterior foram obtidas para análise em HE e AE. Foram avaliados o número de fibras musculares positivas ao AE, de fibras musculares com núcleo periférico e de fibras com núcleo central. Foram quantificadas as áreas com infiltrado inflamatório exuberante com células no estágio inicial de regeneração muscular (Área Infl/Reg) e áreas com infiltrado inflamatório escasso com células em estágio avançado de regeneração. O cromoglicato de sódio promoveu diminuição significativa da mionecrose (p<0,05; teste t de Student) em ambos músculos e aumento da porcentagem de fibras com núcleo periférico. No músculo tibial anterior, a diminuição da mionecrose foi de 26% e o aumento de fibras com núcleo periférico, 30%. A área de Infl/Reg aumentou em ambos os músculos (p<0,05; teste t de Student). Os resultados mostram que o cromoglicato de sódio, ministrado antes do início dos ciclos de degeneração/regeneração, protege os músculos distróficos da mionecrose e interfere nos estágios iniciais da regeneração / Abstract: In the present study, we verified whether disodium cromoglycate (cromolyn), an anti-allergic drug, could protect dystrophic mdx muscIe fibers ITom degeneration. Treated mdx mice (n=8; 14 days of age) received daily intraperitoneal iDJections of cromolyn at a dose of 50mglkg body weight in saline, during 15 days. Cromolyn treatment started before the cycIes of muscIe degeneration-regeneration had started. Control non-treated mice (n=8 mdx) were injected with na equivalent amount of saline. For visualization of muscle fiber damage, treated (n=5) and non­ treated mdx (n=5) mice were injected with Evans blue dye (EBD), a marker of sarcolemmal lesion. Cryostat cross-sections of t.he stemomastoid (STN) and tibialis anterior (TA) muscles were stained with HE. The whole cross-sectional area of the muscIes was divided into a regenerated area, a.Tl area of inflammatory celI infiltration/regeneration a.Tld an area of regeneration. The number of regenerated muscle fibers (central nucIeated fibers), fibers with peripheral c.ell nuclei and degenerated fibers (positive to EBD) was counted in the regenerated area. The areas of inflammatory cell infiltrationlregeneration and of regeneration were expressed as a percentage of the total transverse graft area. Cromolyn lead to a significant decrease in myonecrosis and in t.he percentage of central nucleated fibers (p<O.O5; Student's t test). The number of fibers with peripheral nuclei increased in about 30% in t.he TA muscle. The area of inflammation-regeneration increased (p<O.O5; Student's t test) in the cromolyn treated group. These results show that cromolyn treatment before the cycles of muscle fiber degeneration­ regeneration started protects dystrophic muscIe fiber ITom myonecrosis and promotes the earlier stages ofmuscle fiber regeneration / Mestrado / Anatomia / Mestre em Biologia Celular e Estrutural
7

Proposição de metodologia para estudo de uridina 5'-trifosfato trissódica e citidina 5'-monosfato dissódica e derivados em matriz biológica durante neuropatias periféricas / Proposition methodology for uridine 5'-triphosphate study trissódica and cytidine disodium 5'- monosfato and derivatives in biological matrix for peripheral neuropathies

Suchmacher Neto, Mendel January 2015 (has links)
Made available in DSpace on 2016-03-15T14:17:03Z (GMT). No. of bitstreams: 2 7.pdf: 1019934 bytes, checksum: df1b248bb9c258918248c73b73272de2 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2015 / Fundação Oswaldo Cruz. Instituto de Tecnologia em Fármacos/Farmanguinhos. Rio de Janeiro, RJ, Brasil. / Uridina 5'-trifosfato trissódica (UTPt) e citidina 5'-monofosfato dissódica (CMPd) são nucleotídeos pirimidínicos do ácido nucleico. Eficácia e segurança de fármacos baseados na UTPt e CMPd, usados no tratamento para neuropatias periféricas já foram estudadas, no entanto informações sobre farmacocinética desses fármacos ainda não são conhecidas. O objetivo deste estudo foi propor metodologias para quantificar UTPt e CMPd em matrizes biológicas, baseando-se numa revisão sistemática da literatura. Levando em consideração que a biodisponibilidade das pirimidinas, durante as neuropatias periféricas é diferente da observada em voluntários sadios, os dados disponíveis acerca das concentrações plasmáticas do UTPt e CMPd não devem ser usados para estimar a dose de fármacos baseados nessas pirimidinas. Para diferenciar pirimidinas endógenas e exógenas em matrizes biológicas, estas últimas devem ser marcadas, antes da administração, com material radioativo tais como trício [3H] ou carbono 14 [14C]. Além disso, a cromatografia líquida de alta performance é a técnica mais aplicada para identificação e quantificação de pirimidinas radioativas. Nós concluímos que a radiomarcação de UTPt e CMPd, seguida de separação cromatográfica e detecção por UV e cintilografia líquida, seria uma metodologia factível para estudos de detecção e quantificação de derivados de UTPt e CMPd em matriz biológica / Pyrimidines uridine 5'-triphosphate trisodium (UTPt) and cytidine 5'-monophosphate disodium (CMPd) are standard nucleosides which make up nucleic acids. Efficacy and safety from UTPt and CMPd based drugs on peripheral neuropathies has already been studied. However, information regarding pharmacokinetics of UTPt and CMPd based drugs during pathological condition remains unknown. The aim of this study was to propose methodologies to quantify UTPt and CMPd in biological matrices, based on a systematic literature review. Concerning that the bioavailability of pyrimidines during peripheral neuropathies is different of observed in healthy volunteers, the available data regarding plasmatic levels of UTPt and CMPd should not be used to estimate the dose of UTPt and CMPd based drugs. Furthermore, to differentiate endogenous and exogenous pyrimidines in biological matrices the exogenous pyrimidines must be labeled with [3H] or [14C] before administration. Next, high-performance liquid chromatography (HPLC) has been the most applied technique for identification and quantitation of radiolabeled pyrimidines. We concluded that UTPt and CMPd radiolabelling, followed by chromatographic separation and detection by UV and liquid scintigraphy, is a feasible methodology for detection and quantitation of UTPt and CMPd derivatives in biological matrices.
8

Self-assembly of lyotropic chromonic liquid crystals: Effects of additives and applications

Park, Heung-Shik 30 November 2010 (has links)
No description available.

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