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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

Study of metallophthalocyanines attached onto pre-modified gold surfaces

Mashazi, Philani Nkosinathi January 2007 (has links)
Tetra-carboxy acid chloride phthalocyanine complexes of cobalt, iron and manganese were synthesized and characterized using spectroscopic and electrochemical techniques. These complexes were fabricated as thin films on gold electrode following a covalent immobilization and self-assembling methods. Surface electrochemical and spectroscopic characterization showed that these complexes are surface-confined species. The characterization using spectroscopic and electrochemical methods confirmed the formation of thiol and MPc SAMs on gold electrode. The electrocatalytic behaviour of the SAM modified gold electrodes was studied for the detection of L-cysteine and hydrogen peroxide. The limits of detection (LoD) for Lcysteine were of the orders of 10[superscript -7] mol.L[superscript -1] for all the MPc complexes studied and the LoD for hydrogen peroxide at cobalt phthalocyanine modified gold electrode was of the orders of 10[superscript -7]mol.L[superscript -1] for both electrocatalytic oxidation and reduction. The modification process for gold electrodes was reproducible and showed good stability, if stored in pH 4 phosphate buffer solutions and can be used over a long period of time. The cobalt phthalocyanine modified gold electrode was also investigated for the fabrication of glucose oxidase (GOx)-based biosensor and as an electron mediator between the enzyme and gold electrode. The behaviour of the enzyme modified gold electrode towards the detection of glucose was studied and the results gave a limit of detection of the orders of 10[superscript -6] mol.L[superscript -1] with low binding constant (4.8 mM) of enzyme (GOx) to substrate (glucose) referred to as Michaelis-Menten constant. The practical applications, i.e. the real sample analysis and interference studies, for the enzyme modified gold electrodes were investigated. These studies showed that the enzyme electrode is valuable and can be used for glucose detection.
2

A simulation-based study on the application of artificial neural networks to the NIR spectroscopic measurement of blood glucose

Manuell, John David 01 April 2009 (has links)
Diabetes Mellitus is a major health problem which affects about 200 million people worldwide. Diabetics require their blood glucose levels to be kept within the normal range in order to prevent diabetes-related complications from occurring. Blood glucose measurement is therefore of vital importance. The current glucose measurement techniques are, however, painful, inconvenient and episodic. This document provides an investigation into the use of near-infrared spectroscopy for continuous, non-invasive measurement of blood glucose. Artificial neural networks are used for the development of multivariate calibration models which predict glucose concentrations based on the near-infrared spectral data. Simulations have been performed which make use of simulated spectral data generated from the characteristic spectra of many of the major components of human blood. The simulations show that artificial neural networks are capable of predicting the glucose concentrations of complex aqueous solutions with clinically relevant accuracy. The effect of interference, such as temperature changes, pathlength variations, measurement noise and absorption due other analytes, has been investigated and modelled. The artificial neural network calibration models are capable of providing acceptably accurate predictions in the presence of multiple forms of interference. It was found that the performance of the measurement technique can be improved through careful selection of the optical pathlength and wavelength range for the spectroscopic measurements, and by using preprocessing techniques to reduce the effect of interference. Although the simulations suggest that near-infrared spectroscopy is a promising method of blood glucose measurement, which could greatly improve the quality of life of diabetics, many further issues must be resolved before the long-term goal of developing a continuous non-invasive home glucose monitor can be achieved.
3

Glicosímetro de pulso / Pulse glucometer.

Castro Júnior, Roberto 07 April 2010 (has links)
Este trabalho descreve o desenvolvimento e a avaliação clínica de um instrumento para monitorização contínua e não-invasiva da concentração de glicose no sangue arterial adotando o mesmo método que a oximetria de pulso utiliza para determinação da saturação do sangue arterial. O sistema para medição de glicemia de pulso desenvolvido neste trabalho foi projetado a partir da utilização de um sensor óptico similar aos sensores de oximetria de pulso utilizando os comprimentos de onda de 805 e 1350 nm. Foi realizada uma avaliação clínica do instrumento com 20 voluntários masculinos e femininos entre 16 e 63 anos, de 48 a 112 kg e diferentes raças. Para estes voluntários, o instrumento apresentou uma exatidão (Arms) e desvio padrão (SDR) da ordem de 10 mg/dl, que podem ser considerados muito bons, quando comparado com monitores de glicemia do tipo ponta de dedo, que apresentam uma exatidão da leitura da ordem de 15 mg/dl para a faixa de medidas utilizada. / This paper describes the development and the clinical evaluation of a continuous non-invasive monitoring device for blood glucose concentration in arterial blood. The adopted method was the same one used in pulse oximetry for determining arterial blood saturation. The measurement system developed in this project to determine pulse blood glucose level was based on an optical sensor similar to the pulse oximetry sensors using wavelengths of 805 and 1350 nm. A clinical trial of the device was performed with 20 volunteers, both male and female, aged 16 to 63, weighting 48 to 112 kg and of different races. For this group of volunteers the device presented an accuracy (Arms) e standard deviation (SDR) in the magnitude of 10 mg/dl, considered very good when compared to blood glucose monitors of the fingertip type, which presents a reading accuracy in the magnitude of 15 mg/dl for the range of measurements employed.
4

Glicosímetro de pulso / Pulse glucometer.

Roberto Castro Júnior 07 April 2010 (has links)
Este trabalho descreve o desenvolvimento e a avaliação clínica de um instrumento para monitorização contínua e não-invasiva da concentração de glicose no sangue arterial adotando o mesmo método que a oximetria de pulso utiliza para determinação da saturação do sangue arterial. O sistema para medição de glicemia de pulso desenvolvido neste trabalho foi projetado a partir da utilização de um sensor óptico similar aos sensores de oximetria de pulso utilizando os comprimentos de onda de 805 e 1350 nm. Foi realizada uma avaliação clínica do instrumento com 20 voluntários masculinos e femininos entre 16 e 63 anos, de 48 a 112 kg e diferentes raças. Para estes voluntários, o instrumento apresentou uma exatidão (Arms) e desvio padrão (SDR) da ordem de 10 mg/dl, que podem ser considerados muito bons, quando comparado com monitores de glicemia do tipo ponta de dedo, que apresentam uma exatidão da leitura da ordem de 15 mg/dl para a faixa de medidas utilizada. / This paper describes the development and the clinical evaluation of a continuous non-invasive monitoring device for blood glucose concentration in arterial blood. The adopted method was the same one used in pulse oximetry for determining arterial blood saturation. The measurement system developed in this project to determine pulse blood glucose level was based on an optical sensor similar to the pulse oximetry sensors using wavelengths of 805 and 1350 nm. A clinical trial of the device was performed with 20 volunteers, both male and female, aged 16 to 63, weighting 48 to 112 kg and of different races. For this group of volunteers the device presented an accuracy (Arms) e standard deviation (SDR) in the magnitude of 10 mg/dl, considered very good when compared to blood glucose monitors of the fingertip type, which presents a reading accuracy in the magnitude of 15 mg/dl for the range of measurements employed.
5

Efeitos do emprego de amido resistente decorrente do processo de extrusão no controle glicêmico de cães diabéticos / Effects of employment of resistant starch from extrusion process on glycemic control of diabetic dogs

Teixeira, Fábio Alves 28 April 2016 (has links)
O diabetes mellitus (DM) é uma doença que causa hiperglicemia pela deficiência de insulina, a qual pode levar a morte. A administração de insulina e o manejo alimentar que minimize a variação glicêmica são a base do tratamento. A quantidade, fonte e o processamento do amido podem interferir na resposta glicêmica pós-prandial em cães, mas poucas pesquisas avaliaram estes aspectos em cães diabéticos. Este estudo objetivou avaliar os efeitos do amido menos processado durante o processo de extrusão, no controle glicêmico de cães diabéticos. Foram incluídos 15 cães diabéticos, sem outras afecções, selecionados na rotina do HOVET-FMVZ/USP. Os animais foram alimentados com três rações secas extrusadas: Ba (alta fibra e proteína, baixa gordura e moderado amido oriundos de diversas fontes), Co (ervilha e cevada como fontes de amido, moderada gordura,amido, proteína e fibra) e MP (a base de milho, menos processada para apresentar menor índice de gelatinização do amido). Foi realizada curva glicêmica de 48 horas por sistema de mensuração contínua de glicemia, após 60 dias de tratamento com cada dieta e mesma dose de insulina. Testes estatísticos paramétricos e não paramétricos foram utilizados para comparar a quantidade de alimento e nutrientes ingeridos, efeitos dietéticos em variáveis glicêmicas e lipídicas entre as diferentes dietas. Os animais alimentados com a ração Co apresentaram menor ingestão de amido (p<0,01) comparado à MP, e entre as duas, a Co resultou em maior tempo em hipoglicemia (p<0,01), menor tempo em hiperglicemia (p<0,01) e valores semelhantes de colesterolemia em relação ao alimento Ba, porém maiores que MP (p=0,01). Assim, pôde-se concluir que a ração Co (ervilha e cevada) resultou em melhores variáveis de controle glicêmico e lipídico de cães diabéticos, quando comparada ao alimento a base de milho processado para apresentar menor índice de gelatinização do amido. / Diabetes mellitus (DM) is a disease that causes hyperglycemia by insulin deficiency, which can lead to death. Administration of insulin and feeding management that minimizes glycemic fluctuation are the mainstay of treatment. The amount, source and starch processing may interfere on postprandial glycaemia in dogs, but few researches have evaluated these aspects in diabetic dogs. This study aimed to evaluate the effects of less processed starch, during extrusion process, on glycemic control of diabetic dogs. It was included 15 diabetic dogs without other disorders, selected in routine from Veterinary Hospital (School of Veterinary Medicine and Animal Science University of São Paulo). The animals were fed three extruded dry feed: Ba (high fiber and protein, low fat and moderate starch from various sources), Co (pea and barley as starch sources, moderate fat, starch, protein and fiber) and LP (use corn as a source of starch and was less processed to generate lower gelatinization index of starch). Glucose curve was performed by a continuous glucose measurement system for 48 hours, after 60 days of treatment in every diet and under the same dose of insulin. Statistical tests parametrics and non-parametrics were used to compare the amount of food and nutrient intake and dietary effects on variables of glucose and lipids concentration. The animals fed with Co presented less starch intake (p<0.01) compared to LP, and between Co and LP, Co resulted in greater time under hypoglycaemia (p<0.01), lesser time under hyperglycemia (p<0.01) and remained similar values of cholesterolemia compared to Ba and greater than LP (p=0.01). Thus, it was concluded that the diet with slow digestion starch (pea and barley) resulted in better glycemic and lipidic parameters in diabetic dogs when compared to based corn diet processed to have lower starch gelatinization index.
6

The use of polarized light for biomedical applications

Baba, Justin Shekwoga 15 November 2004 (has links)
Polarized light has the ability to increase the specificity of the investigation of biomedical samples and is finding greater utilization in the fields of medical diagnostics, sensing, and measurement. In particular, this dissertation focuses on the application of polarized light to address a major obstacle in the development of an optical based polarimetric non-invasive glucose detector that has the potential to improve the quality of life and prolong the life expectancy of the millions of people afflicted with the disease diabetes mellitus. By achieving the mapping of the relative variations in rabbit corneal birefringence, it is hoped that the understanding of the results contained herein will facilitate the development of techniques to eliminate the effects of changing corneal birefringence on polarimetric glucose measurement through the aqueous humor of the eye. This dissertation also focuses on the application of polarized light to address a major downside of cardiovascular biomechanics research, which is the utilization of toxic chemicals to prepare samples for histological examination. To this end, a polarization microscopy image processing technique is applied to non-stained cardiovascular samples as a means to eliminate, for certain cardiac samples, the necessity for staining using toxic chemicals. The results from this work have the potential to encourage more investigators to join the field of cardiac biomechanics, which studies the remodeling processes responsible for cardiovascular diseases such as myocardial infarct (heart attacks) and congestive heart failure. Cardiovascular disease is epidemic, particularly amongst the population group older than 65 years, and the number of people affected by this disease is expected to increase appreciably as the baby boomer generation transitions into this older, high risk population group. A better understanding of the responsible mechanisms for cardiac tissue remodeling will facilitate the development of better prevention and treatment regimens by improving the early detection and diagnosis of this disease.
7

Effekten av empowerment vid egenvård för personer med diabetes mellitus typ 2 / The effect of empowerment on self-care for people with diabetes mellitus type 2

Bremer, Alexandra, Karlsson, Sara January 2015 (has links)
Bakgrund: Diabetes mellitus typ 2 förväntas öka drastiskt de kommande åren. För att uppnå förändring behöver personerna få insikt och förståelse för sambandet mellan delar i egenvård. Empowerment har visat sig vara av betydelse för att uppnå egenkontroll och självständighet i egenvård. Syfte: Syftet var att beskriva effekten av empowerment på egenvård hos personer med diabetes mellitus typ 2. Metod: En litteraturöversikt har genomförts baserad på vetenskapliga artiklar med kvantitativ design och analyserades enligt Fribergs trestegsmodell. Resultat: Resultatet är en sammanställning av totalt tio artiklar bestående av ett sjukdoms- specifikt- eller patientdrivet program innehållande empowermentinterventioner. Intervention- erna visar på olika förbättringar i utfallen fysisk aktivitet, kosthållning, kunskap och attityder, egenmätning av blodglukos samt tillfredsställelse och livskvalitet i det dagliga livet. Utfall i egenvård har påvisat en signifikant effekt på reducerad blodglukosnivå i samtliga artiklar. Slutsats: Genom hela litteraturöversikten har effekter av empowerment bevisats ha en bety- delse då deltagarna har erhållit en förbättrad egenvård efter interventionerna. / Background: The prevalence of diabetes mellitus type 2 is expected to rise dramatically within the upcoming years. To achieve a difference, the persons need insight and understand- ing regarding the connections of the elements in the self-care. Patient empowerment has shown to be of great importance when it comes to being able to take control of their self-care. Aim: The aim was to describe the effect of empowerment on self-care in patients with diabe- tes mellitus type 2. Method: An overview of the literature was used, including relevant articles with a quantita- tive design analyzed according to Fribergs three step model. Results: The result is a compilation of a total of ten articles consisting of either a disease- specific or a patient-driven program containing interventions of empowerment. The interven- tion shows a variation of improvements in the events of physical activity, diet, knowledge and attitudes, the self-measurement of blood glucose together with an increased life quality and satisfaction in the everyday life. The outcome in self-care has shown a significant effect con- sidering the reduction in the blood glucose level in all of the articles. Conclusion: Throughout the literature review, it’s been found that empowerment has shown to be an important and positive factor to patients health and treatment programs, as patients have improved and maintained self-care as a result of interventions.
8

Efeitos do emprego de amido resistente decorrente do processo de extrusão no controle glicêmico de cães diabéticos / Effects of employment of resistant starch from extrusion process on glycemic control of diabetic dogs

Fábio Alves Teixeira 28 April 2016 (has links)
O diabetes mellitus (DM) é uma doença que causa hiperglicemia pela deficiência de insulina, a qual pode levar a morte. A administração de insulina e o manejo alimentar que minimize a variação glicêmica são a base do tratamento. A quantidade, fonte e o processamento do amido podem interferir na resposta glicêmica pós-prandial em cães, mas poucas pesquisas avaliaram estes aspectos em cães diabéticos. Este estudo objetivou avaliar os efeitos do amido menos processado durante o processo de extrusão, no controle glicêmico de cães diabéticos. Foram incluídos 15 cães diabéticos, sem outras afecções, selecionados na rotina do HOVET-FMVZ/USP. Os animais foram alimentados com três rações secas extrusadas: Ba (alta fibra e proteína, baixa gordura e moderado amido oriundos de diversas fontes), Co (ervilha e cevada como fontes de amido, moderada gordura,amido, proteína e fibra) e MP (a base de milho, menos processada para apresentar menor índice de gelatinização do amido). Foi realizada curva glicêmica de 48 horas por sistema de mensuração contínua de glicemia, após 60 dias de tratamento com cada dieta e mesma dose de insulina. Testes estatísticos paramétricos e não paramétricos foram utilizados para comparar a quantidade de alimento e nutrientes ingeridos, efeitos dietéticos em variáveis glicêmicas e lipídicas entre as diferentes dietas. Os animais alimentados com a ração Co apresentaram menor ingestão de amido (p<0,01) comparado à MP, e entre as duas, a Co resultou em maior tempo em hipoglicemia (p<0,01), menor tempo em hiperglicemia (p<0,01) e valores semelhantes de colesterolemia em relação ao alimento Ba, porém maiores que MP (p=0,01). Assim, pôde-se concluir que a ração Co (ervilha e cevada) resultou em melhores variáveis de controle glicêmico e lipídico de cães diabéticos, quando comparada ao alimento a base de milho processado para apresentar menor índice de gelatinização do amido. / Diabetes mellitus (DM) is a disease that causes hyperglycemia by insulin deficiency, which can lead to death. Administration of insulin and feeding management that minimizes glycemic fluctuation are the mainstay of treatment. The amount, source and starch processing may interfere on postprandial glycaemia in dogs, but few researches have evaluated these aspects in diabetic dogs. This study aimed to evaluate the effects of less processed starch, during extrusion process, on glycemic control of diabetic dogs. It was included 15 diabetic dogs without other disorders, selected in routine from Veterinary Hospital (School of Veterinary Medicine and Animal Science University of São Paulo). The animals were fed three extruded dry feed: Ba (high fiber and protein, low fat and moderate starch from various sources), Co (pea and barley as starch sources, moderate fat, starch, protein and fiber) and LP (use corn as a source of starch and was less processed to generate lower gelatinization index of starch). Glucose curve was performed by a continuous glucose measurement system for 48 hours, after 60 days of treatment in every diet and under the same dose of insulin. Statistical tests parametrics and non-parametrics were used to compare the amount of food and nutrient intake and dietary effects on variables of glucose and lipids concentration. The animals fed with Co presented less starch intake (p<0.01) compared to LP, and between Co and LP, Co resulted in greater time under hypoglycaemia (p<0.01), lesser time under hyperglycemia (p<0.01) and remained similar values of cholesterolemia compared to Ba and greater than LP (p=0.01). Thus, it was concluded that the diet with slow digestion starch (pea and barley) resulted in better glycemic and lipidic parameters in diabetic dogs when compared to based corn diet processed to have lower starch gelatinization index.

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