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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.
91

The effect of applied fields on crystallisation

Miller, Marina Maria January 2000 (has links)
The thesis provides a background on crystallisation, the effects of applied fields and summarises the techniques used for characterisation and analysis. The study of applied magnetic fields was carried out on three crystallising systems (a) sucrose, (b) lactose and (c) cocoa butter. Both sucrose and lactose were crystallised from aqueous solutions in incubators at 50°C in applied magnetic fields and the resulting crystals compared to the those obtained under zero field conditions. The results for the sucrose study where the magnetic treatment was carried out under static, dynamic pumped and dynamic syphoned conditions domonstrated that changes in phase, crystallinity, morphology and microcrystallinity were a result of the applied magnetic fields and additional strongly bound water was found to be present within the sucrose crystals most likely to be sucrose hydrates. The resulting sucrose crystals were dependant on the type of field applied, the purity of the sucrose solution and the residence time within the applied field. The lactose study under static conditions provided similar results concluding that applied fields resulted in a more controlled crystallisation resulting in increased crystal size, increased crystallinity and changes in morphology. Crystallisation of cocoa butter from the melt, under normal production conditions in applied fields, resulted in changes in morphology and the time taken to reach optimum tempering which were dependant on the type of applied field and the residence time in the applied field.
92

Engineering a fungal β-fructofuranosidase

Trollope, Kim Mary 04 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: β-fructofuranosidases are hydrolytic enzymes that act on sucrose to yield the products glucose and fructose. Under high substrate conditions these enzymes display fructosyltransferase activity which results in the synthesis of fructooligosaccharides (FOS). Some enzymes display higher propensities for FOS synthesis than others, with the determinants of this activity remaining unclear. The consumption of FOS produces a prebiotic effect that positively alters the composition of the colonic microflora, and as a result is linked to improved human and animal health. The increased demand for FOS has necessitated the industrial production of these nutraceuticals. In enzymatic sucrose biotransformation processes operating at high substrate loading and temperatures between 50 and 60°C, β-fructofuranosidase activity is negatively influenced by glucose product inhibition and thermal instability. The aim of this study was therefore to engineer the Aspergillus japonicus β-fructofuranosidase, FopA, to improve a FOS synthesis bioprocess. A dual approach was employed to engineer FopA so as to increase the probability of obtaining an improved enzyme variant(s). A random mutagenesis approach was applied to harness the potential of the randomness of introduced mutations as precise structural knowledge of the enzyme regions involved in the phenotypic presentation of product inhibition, specific activity and thermal stability was unavailable. A semi-rational approach afforded the additional opportunity to reduce the number of variants to be screened, yet theoretically increased the functional content of the library. This study details the development of a method to rapidly quantify FOS using Fourier transform mid infrared attenuated total reflectance spectroscopy and multivariate data analysis. The method offers improvements over conventionally used high performance liquid chromatography in terms of reduced sample analysis times and the absence of toxic waste products. This is the first report on the direct screening of an enzyme variant library for FOS synthesis to identify improved variants and will significantly support future engineering of β-fructofuranosidases using random mutagenesis approaches. The random mutagenesis approach yielded a variant displaying limited relief from glucose inhibition. At the peak difference in performance, the variant produced 28% more FOS from the same amount of sucrose, when compared to the parent. The semi-rational approach, using a combined crystal structure and evolutionary-guided approach, yielded a four amino acid combination variant displaying improved specific activity and thermostability that was able to reduce the time to completion of an industrial-like FOS synthesis reaction by 26%. The positive outcome of the semi-rational approach showed that engineering loops regions in an enzyme is a feasible strategy to improve both specific activity and thermostability, most probably due to the modification of enzyme structural flexibility. A bioinformatic tool that enables the identification of β-fructofuranosidases displaying high-level FOS synthesis from protein sequence alone was also developed during the study. These investigations revealed conserved sequence motifs characteristic of enzymes displaying low- and high-level FOS synthesis and a structural loop, unique to the latter group, that were readily applicable identifiers of FOS synthesis capacity. The tool presented may also be useful to improve the understanding of the structure-function relationships of β-fructofuranosidases by facilitating the identification of variations in groups of enzymes that have been functionally sub-classified. / AFRIKAANSE OPSOMMING: β-fruktofuranosidases is hidrolitiese ensieme wat op sukrose inwerk en glukose en fruktose as produkte vorm. Onder toestande met hoë substraatkondisies vertoon hierdie ensieme fruktosieltransferase-aktiwiteit wat tot die sintese van frukto-oligosakkariede (FOS) lei. Sommige ensieme neig na ʼn hoër FOS-sintese as ander, maar die bepalende faktore vir hierdie aktiwiteit is nog onbekend. Die verbruik van FOS veroorsaak ʼn prebiotiese effek wat die samestelling van kolon mikroflora positief beïnvloed en met verhoogde mens- en dieregesondheid verbind word. Die verhoogde aanvraag vir FOS het die industriële produksie van hierdie nutraseutiese middel genoodsaak. Tydens ensiemgedrewe sukrose-biotransformasieprosesse by hoë substraatladings en temperature tussen 50 en 60 °C, word β-fruktofuranosidase-aktiwiteit negatief deur glukose produkonderdrukking en termiese onstabiliteit beïnvloed. Die doel van hierdie studie was dus om die Aspergillus japonicus β-fruktofuranosidase, FopA, vir ʼn verbeterde FOS-sintese bioproses te manipuleer. ʼn Tweeledige benadering is vir FopA manipulasie gevolg om die waarskynlikheid van verbeterde variant(e) te verhoog. ʼn Lukrake mutagenese benadering, wat die potensiaal van ingevoegde mutasie ewekansigheid inspan, is in die lig van onvoldoende akkurate kennis van die strukturele gedeeltes betrokke by produkinhibisie-, spesifieke aktiwiteit- en termiese stabiliteit fenotipes gevolg. Die toepassing van ʼn semi-rasionele benadering het ook geleentheid vir die sifting van ʼn kleiner variantbibioloteek geskep, terwyl die funksionele inhoud teoreties verhoog word. Die studie beskryf die ontwikkeling van ʼn metode vir die vinnige kwantifisering van FOS, gebaseer op Fourier transform middel infrarooi geattenueerde totale refleksie spektroskopie en meerveranderlike data-analise. Dit is die eerste melding van ʼn direkte sifting van ʼn ensiemvariantversameling vir FOS-sintese om verbeterde variante te identifiseer, en kan die toekomstige manipulasie van β-fruktofuranosidases deur middel van lukrake mutagenese-benaderings beduidend ondersteun. Die lukrake mutagenese-benadering het ʼn variant met beperkte opheffing van glukose-onderdrukking gelewer. By die punt waar die prestasie die meeste verskil, het die variant 28% meer FOS vanaf dieselfde hoeveelheid sukrose geproduseer in vergelyking met die ouer-ensiem. Die semi-rasionele benadering, gegrond op ʼn kombinasie van kristalstruktuur en evolusionêre-geleide benaderings, het ʼn vier-aminosuurkombinasie variant met hoër spesifieke aktiwiteit en termostabiliteit gelewer wat die voltooiingstyd van ʼn tipiese industriële FOS sintesereaksie met 26% kon verkort. Die positiewe uitkoms van die semi-rasionele benadering het aangedui dat manipulasie van die lusgedeeltes in ʼn ensiem ʼn lewensvatbare strategie is om beide spesifieke aktiwiteit en termostabiliteit te verbeter, moontlik as gevolg van wysigings in die buigsaamheid van die ensiemstruktuur. ʼn Bioïnformatika-hulpmiddel vir die identifikasie van β-fruktofuranosidases met hoë vlakke van FOS-sintese op grond van proteïenvolgordes is ook tydens die studie ontwikkel. Motiewe met gekonserveerde volgordes kenmerkend van lae- en hoë-vlak FOS-produserende ensieme en ʼn strukturele lus, uniek tot die laasgenoemde groep, is tydens die ondersoek onthul wat as maklike identifiseerders van FOS-sintesekapasiteit kan dien. Die voorgestelde hulpmiddel kan ook nuttig wees om die struktuur-funksie-verwantskap van β-fruktofuranosidases beter te verstaan deur die identifikasie van variasie in ensiemgroepe wat funksioneel gesubklassifiseer is.
93

The Effects of Sucrose on Ethanol Consumption in Ethanol Naïve and Non-naïve Rats

Dove, Rachel Jolene 05 1900 (has links)
Sucrose fading and intermittent access are two common procedures that induce alcohol consumption in rodents. Sucrose fading procedures involve exposing ethanol naïve rats to a mixture of ethanol and sucrose and gradually reducing the concentration of sugar. Intermittent access procedures involve providing rats with access to ethanol on alternating days. Given that rats will consume ethanol without sucrose, the role of sugar in the sucrose fading procedure is unclear. Rats must be ethanol naïve when they are exposed to treatment with sucrose fading, so there is no point of comparison to show that exposure to sugar in sucrose fading produces higher levels of drinking. There has yet to be any work that isolates the effects of sugar on the consumption of alcohol. The purpose of the present experiment was to examine the effects of sucrose on ethanol consumption in rats with different alcohol histories. Two groups of six rats were exposed to two successive sucrose fading procedures, 30 days apart and their drinking was measured 30 days after each one. One group was exposed to an intermittent access procedure to establish drinking prior to treatment with sucrose fading, the other was ethanol naïve. Following sucrose fading, all rats drank pharmacologically active doses of ethanol. For both groups consumption correlated with the concentration of sucrose and decreased in a step-wise manner as it was faded. For the ethanol experienced rats, consumption dropped below baseline levels as sucrose was faded and decreased further with the second exposure. In contrast, the ethanol-naïve rats did not decrease consumption from the first sucrose fading procedure to the second. Slight differences in peak force of responses were also observed.
94

Scientific Considerations of Olestra as a Fat Substitute

Rattagool, Kullakan 12 1900 (has links)
Olestra is, a sucrose polyester, a noncaloric fat substitute, made from sucrose and several fatty acid esters. It has been approved by the FDA as a food additive used in preparing low-fat deep-frying foods such as savory snacks. Available literature on olestra was evaluated that had both positive and negative connotations. Clinical trials in numerous species of animals including humans were conducted to determine if olestra would affect the utilization and absorption of macro- and micronutrients; the effects of olestra on growth, reproduction, or its toxicity were also examined. The roles of olestra as a fat substitute, how it could effect on humans and the environment, and the potential impacts from its use in large amounts were assessed. Olestra can be removed from the environment by aerobic bacteria and fungi which may be isolated from activated sludge and soils.
95

Effect of sugar supplementation in lactating dairy cows

Vargas Rodriguez, Claudio Fabian January 1900 (has links)
Master of Science / Department of Animal Science and Industry / Barry Bradford / During the past decades, the dairy industry has been challenged to find alternative approaches in order to feed cows without affecting their performance or increasing production costs. To accomplish these objectives, some options that have been implemented are the inclusion of short chain carbohydrates to replace starch and the addition of synthetic supplements to increase feed efficiency. In order to assess the impact of these strategies, an experiment was conducted to evaluate productive responses of lactating dairy cattle when they received sucrose and/or exogenous amylase in low starch diets. The results indicated that milk production, milk component profile, and feed efficiency were not significantly altered by the use of the enzyme, sucrose inclusion, or the combination of both. Comparing these results with the literature revealed apparent inconsistencies in responses to the inclusion of sugar in dairy rations. For that reason, a meta-analysis was performed to determine the impact of different sugar sources on milk production, and also to evaluate the impact of other dietary factors on response to dietary sugar. The results indicated that dry matter intake responses were significantly (P < 0.05) affected by an interaction between added sugar and dietary forage neutral detergent fiber content, but overall, dry matter intake tended to increase when sugar replaced corn grain in diets. Energy corrected milk was not affected by dietary sugar, but milk production showed a tendency to respond to treatment, dependent on an interaction between added sugar and rumen undegradable protein. In summary, sugar inclusion may promote small increases in dry matter intake, but the impact on milk production is inconsistent; both factors may be influenced by the diet to which sugar is added.
96

Limites de tolerância do espermatozóide caprino a soluções hiperosmóticas de sacarose e taxa de sobrevivência após criopreservação em diluentes contendo sacarose ou trealose e concentrações reduzidas de crioprotetores permeantes / Tolerance limits of goat spermatozoa to hyperosmotic sucrose solutions and survival rate after cryopreservation in extenders containing sucrose or trehalose and reduced concentrations of permeant cryoprotectants

Becker-Silva, Sandra Cristina 31 August 2004 (has links)
Foi conduzida uma série de experimentos onde se buscou definir: 1) o limite de tolerância do espermatozóide caprino a soluções hiperosmóticas de sacarose; 2) um diluente para criopreservação de sêmen que minimizasse as flutuações de volume celular. O limite de tolerância da membrana, avaliado pelo corante eosina-nigrosina, foi de 930 mOsm em soluções de sacarose em Ringer-lactato a 38oC. Os danos à integridade de membrana (IM), em osmolalidades acima deste valor, se estabeleceram no primeiro minuto de exposição e não se agravaram até 10 minutos depois. A motilidade (MOT) foi mais afetada que a IM. A rediluição abrupta em meio isosmótico causou dano extenso e proporcional ao grau de desidratação prévia. Nos experimentos seguintes, adição de 375 mM de sacarose ao diluidor TRIS-gema com 6,8% de glicerol (TGG), 5 minutos antes da congelação, resultou em MOT e IM similares ao controle TGG sem sacarose. Descongelação e rediluição a 4oC favoreceram a MOT e, a 38oC, favoreceram a IM. O diluente TRIS-gema com 375 mM de sacarose e concentração de glicerol reduzida para 1,7% apresentou melhor MOT e IM que o controle (65% e 187% vs 52% e 100%, respectivamente). A MOT após 2 h e o vigor após 6 h foram maiores quando a rediluição pós-descongelação foi em 5 passos se comparado a 3 passos (28% e 9% vs 19% e 2%, respectivamente). Na fase seguinte do trabalho, diluentes elaborados com 300 mM após 6 h a 38oC, melhor MOT e vigor que o controle (33% e 26% vs 15% e 10%, respectivamente). A descongelação a 20oC favoreceu a MOT e o vigor nos tempos zero, 2 h e 6 h pós-descongelação em todos os grupos contendo sacarose. O etilenoglicol não diferiu do glicerol na concentração de 3,4% quando adicionado a diluente contendo 300 mM de sacarose. Nestes diluentes, a rediluição em 5 passos a 20oC não diferiu em MOT e IM da feita em 1 passo a 38oC. No último experimento, sêmen congelado em diluente contendo 300 mM de trealose e zero% de glicerol mostrou melhor IM após descongelação em um passo a 38oC (320% vs 100% no controle) e maior MOT às 6 h após descongelação e rediluição em 5 passos a 20oC (56% vs 26% no controle). Conclui-se que o sêmen caprino tolera soluções de sacarose até o limite de 930 mOsm, mas a rediluição deve ser progressiva. A desidratação parcial, causada por soluções concentradas de sacarose ou trealose, permite a congelação de sêmen sem adição de crioprotetores permeantes. Os melhores resultados foram obtidos em diluente TRIS-gema sem glicerol e adicionado de 300 mM de trealose. / The objective of this study was to: 1) define the tolerance limits of goat sperm to hyperosmotic sucrose solutions; 2) establish an extender that minimizes cell volume variations during the processes of freezing and thawing. Boer goat semen was diluted with Ringer-lactate-Sucrose solutions at 38oC. The hyperosmotic tolerance limit was 930 mOsm evaluated with eosin-nigrosin stain. At osmolalities above this value, damage was evident after 1 min and was not affected by further exposure. Redilution in a single step resulted in massive membrane damage that was nearly proportional to the dehydration intensity previously undergone. Motility (MOT) was more distinctly impaired than membrane integrity (MI). In the next experiments, addition of 375 mM sucrose (Suc) 5 min previous to freezing to TRIS-egg yolk extender containing 6.8% glycerin (TYG) resulted in sperm motility (MOT) and MI similar to control extender TYG without sucrose. Thawing and redilution at 4oC affected favorably the MOT, and at 38oC, was favorable to MI. When freezing in TRIS-egg yolk-Suc extenders with low glycerin concentration (1.7%) MOT and MI were significantly higher than in the control TYG (65% and 187% vs 52% and 100%, respectively). MOT 2 h after thawing and intensity of motility (INTMOT) after 6 h after thawing were better preserved after a redilution of 5 increasing volume-steps than after redilution of 3 steps (28% and 9% vs 19% and 2%, respectively). In sequence, extenders containing 300 mM sucrose and thawed-rediluted 5 steps at 20oC improved MOT and INTMOT after 6 h (33% and 26% vs 15% and 10% in the control Group). The thawing-redilution at 20oC improved the results in all groups containing sucrose. At a concentration of 3.4% added to TRIS-yolk extender with 300 mM sucrose, the cryoprotectant ethylene glycol gave similar results as glycerin. MOT and INTMOT in the different time intervals were not influenced by redilution in 5 steps at 20oC or in one step at 38<SUPoC. In the last experiment made, semen frozen in a TRIS-yolk extender with 300 mM trehalose and devoid of glycerin showed the best MI after thawing-redilution in 1 step at 38oC (320% vs 100% in the control Group). The highest MOT after 6 h incubation was observed when this group was thawed-rediluted at 20oC in 5 steps (56% vs 26% in the control). From the results obtained it may be concluded that the upper tolerance limit of goat spermatozoa to hyperosmotic sucrose solutions is 930 mOsm. The redilution and return to isosmolality should be stepwise made. Goat semen can be frozen in extenders devoid of permeant cryoprotectants like glycerin when, previous to freezing, the cells are partially dehydrated by concentrated sucrose or trehalose solutions. The best survival rate was obtained when freezing goat spermatozoa in a glycerin-free TRIS-yolk-extender containing 300 mM of trehalose.
97

Alívio de dor em neonatos pré-termo: avaliação da eficácia do uso continuado de sacarose / Pain relief in preterm neonates: assessment of the efficacy of sucrose used in continued form.

Gaspardo, Claudia Maria 09 November 2010 (has links)
A trajetória de desenvolvimento do neonato pré-termo se inicia no contexto da Unidade de Terapia Intensiva Neonatal, permeado pela presença contínua de diversos estímulos dolorosos. As experiências iniciais e repetidas de dor podem ter efeito em longo prazo para os neonatos vulneráveis. A Academia Americana de Pediatria e a Sociedade Pediátrica Canadense recomendam o uso da solução de sacarose como intervenção não-farmacológica para alívio de dor em neonatos, entretanto, a eficácia e segurança do uso continuado da sacarose necessitam de investigação. O presente estudo randomizado controlado duplo-cego teve por objetivos avaliar a eficácia da administração via oral da solução de sacarose a 25%, em esquema de doses repetidas no alívio da dor em neonatos pré-termo e avaliar os possíveis efeitos colaterais advindos do uso continuado da sacarose para os neonatos. Trinta e três neonatos pré-termo com muito baixo peso ao nascer foram distribuídos em dois grupos: Grupo Sacarose (n = 17) e Grupo Água (n = 16). Os neonatos foram avaliados durante quatro dias consecutivos, durante procedimento de punção para coleta de sangue. Cada avaliação foi dividida em cinco fases: Linha de Base, Preparação para Punção (antissepsia), Punção, Recuperação com Manuseio (curativo) e Recuperação sem Manuseio. O indicador de dor foi avaliado pela atividade facial, mensurada pelo Neonatal Facial Coding System (NFCS). O nível de ativação dos neonatos foi mensurado pelo estado de vigília e sono e pela frequência cardíaca. Na primeira avaliação, os neonatos de ambos os grupos não receberam nenhuma substância antes do procedimento doloroso. Nos três dias seguintes, o Grupo Sacarose recebeu 0,5ml/kg de sacarose oral e o Grupo Água recebeu água estéril, dois minutos antes de cada procedimento doloroso. Foram obtidos dados de evolução clínica dos neonatos nos prontuários médicos. Os resultados encontrados revelaram que no primeiro dia de avaliação os neonatos de ambos os grupos anteciparam a reação ao estímulo doloroso de punção, apresentando elevação significativa do escore do NFCS, do estado de vigília e sono e da frequência cardíaca, já na antissepsia, sendo que durante a recuperação a frequência cardíaca continuou elevada em comparação à fase de Linha de Base. A partir do segundo dia de avaliação, o Grupo Sacarose apresentou menores escores do NFCS e do estado de vigília e sono, durante o procedimento, em comparação ao Grupo Água. O indicador fisiológico de frequência cardíaca não apresentou diferença significativa entre os grupos, entretanto, a sacarose reduziu o tempo necessário para o neonato se recuperar e atingir a estabilidade fisiológica após passar pelo procedimento doloroso de punção. Não houve diferença significativa na evolução clinica dos neonatos de ambos os grupos, o que demonstra que a sacarose não causou efeitos colaterais em curto prazo aos neonatos. Conclui-se que a dose de 0,5ml/kg de solução de sacarose a 25% administrada em esquema de doses repetidas foi eficaz para o alívio da dor em neonatos pré-termo e não trouxe efeitos colaterais imediatos para o estado de saúde dos neonatos. / The development pathway of the preterm neonate begins in the context of the Neonatal Intensive Care Unit, permeated by the presence of several painful stimuli. Initial and repetitive pain may have long-term effect for vulnerable newborns. The American Academy of Pediatrics and Canadian Pediatric Society recommends the use of sucrose solution as non-pharmacological intervention for pain relief in neonates, however, the efficacy and safety of continued use of sucrose needs investigation. The present randomized controlled double-blind study aimed to assess the efficacy of oral administration of sucrose solution to 25% in repeated doses to relief pain in preterm neonates and to assess the possible side effects arising from the continued use of sucrose to newborns. Thirty-three preterm neonates with very low birth weight were divided into two groups: Sucrose Group (n = 17) and Water Group (n = 16). The newborns were assessed during four consecutive days during puncture procedure for blood collection. Each assessment was divided into five phases: Baseline, Antisepsis, Puncture, Dressing, and Recovery. The indicator of pain was assessed by facial activity, measured by the Neonatal Facial Coding System (NFCS). The level of activation of the neonates was measured by the sleep-wake states and heart rate. In the first assessment, the newborns of both groups did not receive any substance before the painful procedure. During the next three days, Sucrose Group received 0.5ml/kg of oral sucrose and Water Group received sterile water two minutes before each painful procedure. Clinical outcomes data of newborns were obtained in the medical records. The results showed that on the first day of assessment newborns of both groups have anticipated the reactivity to painful stimuli, with significant increase of NFCS score, sleep-wake states and heart rate as early as antisepsis, and during recovery heart rate remained increased in comparison to the Baseline phase. From the second day of assessment, the Sucrose Group had lower NFCS scores and sleep-wake states during the procedure, compared to the Water Group. The physiological indicator of heart rate showed no significant difference between groups, however, sucrose has reduced the time required for the infant to recover and achieve physiological stability after passing through the painful procedure of puncture. There was no significant difference in clinical outcome of newborn in both groups, demonstrating that sucrose did not cause short term side effects in neonates. The finding was that the dose of 0.5 ml/kg of sucrose solution to 25% administered in repeated doses was effective for pain relief in preterm and did not caused short term side effects to the health of newborns.
98

Processo de peroxidação de açúcar tipo VHP na produção de açúcar refinado: implicações químicas, tecnológicas e microbiológicas / Clarification of the type VHP sugar syrup by hydrogen peroxide: chemical implications, technological and microbiological

Mandro, Juliana Lorenz 28 June 2016 (has links)
Atualmente, o setor sucroenergético está se tornando cada vez mais competitivo, o que de fato é incentivado, principalmente, pela representativa demanda e exigências do mercado externo. Ao se analisar a produção do açúcar refinado, podem-se encontrar barreiras para a sua ampla aceitação nacional e internacional devido ao método de clarificação empregado, uma vez que este é realizado através da queima de enxofre elementar em câmaras de combustão. O uso do sulfito acima dos limites permitidos pode ocasionar potenciais problemas de saúde pública. Neste sentido, o Brasil tem realizado estudos sobre a adoção de novas tecnologias para a substituição da sulfitação, sem alteração da qualidade do açúcar refinado a ser produzido. Partindo deste pressuposto, fez-se a avaliação do uso do peróxido de hidrogênio (H2O2) em solução comercial (35% v/v) como reagente alternativo ao dióxido de enxofre para obtenção de açúcar refinado com menor cor ICUMSA. Para isso, na calda de açúcar do tipo VHP, foram testadas doses distintas de peróxido de hidrogênio, aliadas a diferentes pH e temperaturas frente a um Delineamento composto central composto central, permitindo a otimização e o acompanhamento das transformações decorrentes do processo. Com isso, obteve-se como melhores condições o pH 7,5 e 10, temperaturas entre 50 e 70 °C e dosagens entre 500 e 797,6 ppm de H2O2. A análise a partir da cinética química da peroxidação da calda permitiu observar maiores reduções da cor ICUMSA em geral nos tempos de 50 a 75 minutos e nos 30 primeiros minutos para os pontos extremos de pH, temperatura e dose de H2O2. A degradação de sacarose não foi um fator expressivo quanto ao tempo, pois a mesma na maioria dos casos foi degradada nos 5 primeiros minutos e após esse tempo se mantinha sem muitas alterações, sendo mais vulnerável as condições de pH 3,32 e 11,68, altas temperaturas (83,6 °C) e máxima dosagem H2O2 (1000 ppm) aplicados. Além de favorecer a redução da cor ICUMSA da calda, o H2O2 também se mostrou como um bom agente antimicrobiano, principalmente quando associado às altas temperaturas. Agindo com maior intensidade na diminuição da carga bactériana do que na diminuição da carga fungica. A rede neural artificial (RNA) mostrou um bom ajuste e indicou a variável °Brix (teor de sólidos solúveis) como a que apresentou maior influência na redução da cor ICUMSA e a variável tempo a que menor influenciou na redução de cor. / Nowadays, the sugar-energy industry is becoming increasingly competitive, which indeed is encouraged mainly by representative demand and requirements of foreign markets. When analyzing the production of refined sugar can be found barriers to their widespread international acceptance due to the clarification method employed, since this is performed by burning elemental sulfur in combustion boilers. The use of sulfite above the permitted limits can result in potential public health problems. In this regard, Brazil has conducted studies on the adoption of new technologies to replace the sulfite, without changing the quality of the produced refined sugar. On that basis, it was done the evaluation of the use of hydrogen peroxide (H2O2) in commercial solution (35% v/v) as an alternative reagent to sulfur dioxide to obtain refined sugar with less ICUMSA color. For this the sugar liquor VHP different doses of hydrogen peroxide were tested, together with different pH and temperatures outside a central composite design, enabling optimization and monitoring of changes resulting from the process. Thus there was obtained as the best pH conditions 7.5 to 10, temperatures between 50 and 70 °C and dosages between 500 and 797.6 ppm H2O2. The analysis from the chemical kinetics of the peroxidation of the liquor has observed greater reductions in ICUMSA color in general in the time of 50 minutes to 75 minutes and in the first 25 minutes to the extremes of pH, temperature and H2O2 dose. As for sucrose degradation was not a significant factor, since it in most cases was first degraded within 5 minutes and after this time remained without many changes, being more vulnerable conditions (3.32 and 11.68), high temperatures (83.6 °C) and H2O2 maximum dosage (1000 ppm) applied. In addition to further reduce color ICUMSA H2O2 Liquor also showed such a good antimicrobial agent, particularly when combined with high temperatures. Acting with more intensity in the decrease of bacteria than the reduction of fungi. The artificial neural network (ANN) showed good fit and indicated the variable ° Brix (soluble solids) as the one with the greatest influence in reducing the ICUMSA color and variable time that less influenced the color reduction.
99

Dor em neonatos pré-termo em Unidade de Terapia Intensiva Neonatal: avaliação e intervenção com sacarose / Pain in preterm neonates in a Neonatal Intensive Care Unit: assessment and intervention with sucrose

Gaspardo, Claudia Maria 11 August 2006 (has links)
A dor encontra-se inerente aos procedimentos de tratamento intensivo dos recém-nascidos pré-termo em Unidade de Terapia Intensiva Neonatal. As experiências precoces e repetidas de dor podem ter efeitos a longo prazo para os recém-nascidos vulneráveis. A Academia Americana de Pediatria e a Sociedade Pediátrica Canadense recomendam o uso da solução de sacarose como rotina para alívio da dor em Unidade de Terapia Intensiva Neonatal, durante os procedimentos invasivos e dolorosos. O presente estudo teve por objetivo avaliar as reações de dor de neonatos pré-termo durante procedimento de coleta de sangue, analisando o momento da punção, assim como os efeitos do manuseio dos neonatos para a anti-sepsia e o curativo e avaliar a eficácia da intervenção com solução de sacarose a 25% no alívio da dor administrando-a em dose única de 0,5ml/Kg. Trinta e três neonatos foram distribuídos randomicamente em dois grupos: Grupo Sacarose (n=17) e Grupo Água (n=16). Os neonatos foram avaliados durante dois dias consecutivos. Na primeira avaliação, os neonatos de ambos os grupos não receberam nenhuma substância antes do procedimento doloroso. Na segunda avaliação, o Grupo Sacarose recebeu sacarose oral e o Grupo Água recebeu água estéril, dois minutos antes do procedimento invasivo e doloroso de punção para coleta de sangue. Cada avaliação foi dividida em cinco fases: Linha de Base, Preparação para Punção (anti-sepsia), Punção, Recuperação com Manuseio (curativo) e Recuperação sem Manuseio. O indicador de dor foi avaliado pela atividade facial, que foi mensurada pelo Neonatal Facial Coding System. O nível de ativação dos neonatos foi medido pelo estado de vigília e sono e pela freqüência cardíaca. A análise entre grupos e intra-grupo dos dados revelou que no primeiro dia de avaliação os neonatos anteciparam a reação ao estímulo doloroso de punção, apresentando elevação significativa dos indicadores atividade facial, estado de vigília e sono e freqüência cardíaca avaliados na Preparação para Punção. Ambos os grupos mostraram alta reatividade comportamental e fisiológica na fase de Punção, em comparação à Linha de Base. Durante a recuperação, o indicador fisiológico de freqüência cardíaca continuou elevado. No segundo dia de avaliação os neonatos que receberam 0,5ml/Kg de solução de sacarose a 25% apresentaram menores escores de atividade facial, indicativo de menos dor, em comparação aos neonatos que receberam água estéril, antes, durante e após o procedimento de punção para coleta de sangue. Entretanto, o indicador fisiológico de freqüência cardíaca não apresentou diferença significativa entre os grupos. Conclui-se que a dose de 0,5ml/Kg de solução de sacarose a 25%, recomendada para a administração da substância em doses repetidas, foi eficaz no alívio de dor, avaliada por meio da redução de indicadores comportamentais. Entretanto, o indicador fisiológico continuou elevado, sugerindo a necessidade de outras medidas de conforto associadas à sacarose, com a finalidade de atenuação do estado de ativação e irritabilidade do sistema nervoso central. / Pain is inherent to the intensive treatment procedures offered to preterm neonates in Neonatal Intensive Care Units. The early and repeated experiences of pain may have a long-term effects for the vulnerable neonates. The American Academy of Pediatrics and the Canadian Pediatric Society recommend using a sucrose solution for pain relief in NICU during invasive and painful procedures. The present study had the purpose to assess the pain reactions of preterm neonates during a procedure for blood collection, evaluating the moment of puncture as well as the effects of handling the neonates for antisepsis and for bandages, and evaluating the efficacy of the intervention with the sucrose solution at 25% for pain relief by administering a single dose of 0.5 ml/Kg. Thirty-three neonates were randomly assigned to two groups: Sucrose Group (n=17) and Water Group (n=16). The neonates were evaluated during two consecutive days. In the first assessment, the neonates from both groups did not receive the solution before the painful procedure. In the second assessment, the Sucrose Group received oral sucrose and the Water Group received sterile water, two minutes before the invasive painful procedure of puncture for blood collection. Each evaluation was divided into five phases: Baseline, Preparation for Puncture (antisepsis), Puncture, Recovery with Handling (bandage), and Recovery without Handling. The indicators of pain were evaluated by the facial activity, measured by the Neonatal Facial Coding System. The level of activation of the neonates was measured by their sleep-awake state and heart rate. The between and within-group data analysis revealed that, on the first day of evaluation, the neonates anticipated their reaction to the painful puncture stimulus, and showed a significant increase in the behavioral indicators of facial activity, sleep-awake state, and heart rate evaluated at the Preparation for Puncture. Both groups showed a high behavioral and physiological reactivity in the Puncture phase, in comparison to the Baseline. During recovery, the physiological indicator of heart rate continued high. In the second day of evaluation, the neonates who received 0.5 ml/Kg of the sucrose solution at 25% showed lower scores of facial activity, which indicates they experienced less pain in comparison to the neonates who received sterile water before, during, and after the procedure of puncture for blood collection. However, there were no significant differences in terms of the physiological indicator of heart rate. It is concluded that the dose of 0.5 ml/kg of sucrose solution at 25%, recommended for the administration in repeated doses, was efficient for pain relief, evaluated by means of the reduction of behavioral indicators. However, the physiological indicator remained high, which suggests there is a need for other comfort manegement associated to sucrose, with the aim to diminish the state of activation and irritability of the central nervous system.
100

Dor em neonatos pré-termo em Unidade de Terapia Intensiva Neonatal: avaliação e intervenção com sacarose / Pain in preterm neonates in a Neonatal Intensive Care Unit: assessment and intervention with sucrose

Claudia Maria Gaspardo 11 August 2006 (has links)
A dor encontra-se inerente aos procedimentos de tratamento intensivo dos recém-nascidos pré-termo em Unidade de Terapia Intensiva Neonatal. As experiências precoces e repetidas de dor podem ter efeitos a longo prazo para os recém-nascidos vulneráveis. A Academia Americana de Pediatria e a Sociedade Pediátrica Canadense recomendam o uso da solução de sacarose como rotina para alívio da dor em Unidade de Terapia Intensiva Neonatal, durante os procedimentos invasivos e dolorosos. O presente estudo teve por objetivo avaliar as reações de dor de neonatos pré-termo durante procedimento de coleta de sangue, analisando o momento da punção, assim como os efeitos do manuseio dos neonatos para a anti-sepsia e o curativo e avaliar a eficácia da intervenção com solução de sacarose a 25% no alívio da dor administrando-a em dose única de 0,5ml/Kg. Trinta e três neonatos foram distribuídos randomicamente em dois grupos: Grupo Sacarose (n=17) e Grupo Água (n=16). Os neonatos foram avaliados durante dois dias consecutivos. Na primeira avaliação, os neonatos de ambos os grupos não receberam nenhuma substância antes do procedimento doloroso. Na segunda avaliação, o Grupo Sacarose recebeu sacarose oral e o Grupo Água recebeu água estéril, dois minutos antes do procedimento invasivo e doloroso de punção para coleta de sangue. Cada avaliação foi dividida em cinco fases: Linha de Base, Preparação para Punção (anti-sepsia), Punção, Recuperação com Manuseio (curativo) e Recuperação sem Manuseio. O indicador de dor foi avaliado pela atividade facial, que foi mensurada pelo Neonatal Facial Coding System. O nível de ativação dos neonatos foi medido pelo estado de vigília e sono e pela freqüência cardíaca. A análise entre grupos e intra-grupo dos dados revelou que no primeiro dia de avaliação os neonatos anteciparam a reação ao estímulo doloroso de punção, apresentando elevação significativa dos indicadores atividade facial, estado de vigília e sono e freqüência cardíaca avaliados na Preparação para Punção. Ambos os grupos mostraram alta reatividade comportamental e fisiológica na fase de Punção, em comparação à Linha de Base. Durante a recuperação, o indicador fisiológico de freqüência cardíaca continuou elevado. No segundo dia de avaliação os neonatos que receberam 0,5ml/Kg de solução de sacarose a 25% apresentaram menores escores de atividade facial, indicativo de menos dor, em comparação aos neonatos que receberam água estéril, antes, durante e após o procedimento de punção para coleta de sangue. Entretanto, o indicador fisiológico de freqüência cardíaca não apresentou diferença significativa entre os grupos. Conclui-se que a dose de 0,5ml/Kg de solução de sacarose a 25%, recomendada para a administração da substância em doses repetidas, foi eficaz no alívio de dor, avaliada por meio da redução de indicadores comportamentais. Entretanto, o indicador fisiológico continuou elevado, sugerindo a necessidade de outras medidas de conforto associadas à sacarose, com a finalidade de atenuação do estado de ativação e irritabilidade do sistema nervoso central. / Pain is inherent to the intensive treatment procedures offered to preterm neonates in Neonatal Intensive Care Units. The early and repeated experiences of pain may have a long-term effects for the vulnerable neonates. The American Academy of Pediatrics and the Canadian Pediatric Society recommend using a sucrose solution for pain relief in NICU during invasive and painful procedures. The present study had the purpose to assess the pain reactions of preterm neonates during a procedure for blood collection, evaluating the moment of puncture as well as the effects of handling the neonates for antisepsis and for bandages, and evaluating the efficacy of the intervention with the sucrose solution at 25% for pain relief by administering a single dose of 0.5 ml/Kg. Thirty-three neonates were randomly assigned to two groups: Sucrose Group (n=17) and Water Group (n=16). The neonates were evaluated during two consecutive days. In the first assessment, the neonates from both groups did not receive the solution before the painful procedure. In the second assessment, the Sucrose Group received oral sucrose and the Water Group received sterile water, two minutes before the invasive painful procedure of puncture for blood collection. Each evaluation was divided into five phases: Baseline, Preparation for Puncture (antisepsis), Puncture, Recovery with Handling (bandage), and Recovery without Handling. The indicators of pain were evaluated by the facial activity, measured by the Neonatal Facial Coding System. The level of activation of the neonates was measured by their sleep-awake state and heart rate. The between and within-group data analysis revealed that, on the first day of evaluation, the neonates anticipated their reaction to the painful puncture stimulus, and showed a significant increase in the behavioral indicators of facial activity, sleep-awake state, and heart rate evaluated at the Preparation for Puncture. Both groups showed a high behavioral and physiological reactivity in the Puncture phase, in comparison to the Baseline. During recovery, the physiological indicator of heart rate continued high. In the second day of evaluation, the neonates who received 0.5 ml/Kg of the sucrose solution at 25% showed lower scores of facial activity, which indicates they experienced less pain in comparison to the neonates who received sterile water before, during, and after the procedure of puncture for blood collection. However, there were no significant differences in terms of the physiological indicator of heart rate. It is concluded that the dose of 0.5 ml/kg of sucrose solution at 25%, recommended for the administration in repeated doses, was efficient for pain relief, evaluated by means of the reduction of behavioral indicators. However, the physiological indicator remained high, which suggests there is a need for other comfort manegement associated to sucrose, with the aim to diminish the state of activation and irritability of the central nervous system.

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