• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 41
  • 41
  • 12
  • 12
  • 3
  • 2
  • 1
  • 1
  • Tagged with
  • 146
  • 74
  • 38
  • 28
  • 17
  • 12
  • 10
  • 9
  • 9
  • 9
  • 9
  • 7
  • 7
  • 7
  • 7
  • 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.
131

Efeito in situ de uma solução de bicarbonato de sódio em esmalte dental após simulação de desafios erosivos endógenos / In situ effect of a sodium bicarbonate solution on enamel after simulation of endogenous dental erosion.

Danielle Cristine Furtado Messias 10 February 2010 (has links)
Uma das medidas recomendadas para o controle da progressão de lesões de erosão dental de origem intrínseca é o enxágüe bucal com solução de bicarbonato de sódio, visando à neutralização de ácidos gástricos presentes na boca. Contudo, a prescrição de tal solução faz-se em bases empíricas. Assim, este estudo avaliou, através de um modelo in situ, o efeito de uma solução de bicarbonato de sódio no controle da erosão dental causada por desafios ácidos endógenos. Este estudo caracterizou-se por um experimento do tipo cross-over 2x2, composto por duas fases experimentais de 5 dias cada. Após um período de lead-in de 2 dias, quatorze voluntários utilizaram dispositivos intrabucais contendo, em cada lado (direito e esquerdo), um fragmento de esmalte bovino polido, esterilizado e delimitado de modo a obter áreas hígidas de referência. Duas vezes ao dia, um dos espécimes foi exposto, ex-vivo, à solução de ácido clorídrico (0,01 M, pH = 2) por 2 min. Imediatamente após, os aparelhos foram reinseridos na boca e os voluntários realizaram enxágüe bucal com solução de bicarbonato de sódio ou água deionizada por 1 min. Após um período de wash-out de 2 dias, os voluntários iniciaram a segunda fase empregando a substância alternativa para o enxágüe bucal. Ao término das duas etapas, foram avaliadas a profundidade de desgaste através de perfilometria ótica e a microdureza Knoop. ANOVA e o teste de Tukey demonstraram que o desgaste do esmalte foi significativamente reduzido quando se empregou a solução de bicarbonato de sódio para o enxágüe bucal. Para a microdureza, ANOVA demonstrou apenas presença de diferença significativa em função da condição do substrato (p < 0,0001). Os espécimes erodidos apresentaram valores de microdureza significativamente menores do que o grupo não submetido ao desafio ácido. O enxágüe bucal com solução de bicarbonato de sódio controlou a erosão no esmalte submetido a simulações de episódios erosivos endógenos. / One of the recommended measures to control dental erosion of intrinsic origin is the oral rinse with sodium bicarbonate solution, which has been suggested to neutralize the gastric acid regurgitated into the oral cavity. However, the efficacy of this prescription has not yet been proved. Therefore, the aim of this study was to evaluate in situ the effect of a sodium bicarbonate rinse in the control of dental erosion in enamel exposed to gastric acid-like solution. This study comprised two experimental legs. After a 2-day lead-in period, fourteen volunteers wore palatal devices containing two polished, sterilized enamel slabs. Throughout the experimental period of 5-d, one of the two specimens was exposed twice daily extra-orally to hydrochloric acid solution (0,01 M, pH=2) for 2 min. Immediately after, devices were reinserted in the mouth and volunteers rinsed their oral cavity with a sodium bicarbonate solution or deionized water for 60s. In the second leg of this study, after a 2-day washout period, appliances were refilled with a new set of enamel specimens and participants were crossed over to receive the alternate rinse. The wear depth accessed using optical profilometry and Knoop surface microhardness were evaluated. Analysis of Variance (ANOVA) and Tukey\'s test demonstrated that wear of enamel was significantly reduced when a sodium bicarbonate solution was used to rinse the oral cavity following erosive episodes. For microhardness, ANOVA demonstrated only significant differences in function of the enamel condition (p < 0,0001). The eroded specimens presented microhardness values significantly lower than the group not submitted to the acid challenge. Sodium bicarbonate rinse controlled erosion of enamel caused by gastric acid-like solution.
132

Buffered vs. Unbuffered Local Anesthesia in Mandibular Molars Diagnosed with Symptomatic Irreversible Pulpitis: A Controlled, Randomized, Double-Blind Study

Alena, Peter January 2022 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: Profound pulpal anesthesia is not always adequate in mandibular teeth after the administration of local anesthesia, especially in the presence of irreversible pulpitis. Failure to achieve anesthesia has been seen in 30–80% of patients in teeth with a diagnosis of irreversible pulpitis. Onpharma™ developed an FDA-approved device that uses sodium bicarbonate to buffer a standard local anesthetic (LA) solution so that its pH may become closer to its pKa. Claims have been made that buffering a local anesthetic increases the anesthetic’s effect. Previous studies on the anesthetic efficacy of Onpharma’s Onset buffering system were inconclusive and may be dependent on the techniques used. Objectives: The aim of this study is to determine whether a buffered local anesthetic can lead to more profound and faster pulpal anesthesia in mandibular molars diagnosed with symptomatic irreversible pulpitis as compared to a standard, unbuffered local anesthetic. Materials and Methods: 40 total subjects completed the study. Screened and eligible subjects with a mandibular molar diagnosed with symptomatic irreversible pulpitis were randomly allocated into 2 groups so 1 group received a total of 3 cartridges of a standard, unbuffered 2% lidocaine with 1:100,000 epinephrine via inferior alveolar nerve block (IANB) followed by supplemental buccal and lingual infiltrations, while the other received the equivalent yet buffered formulation. An electronic pulp tester (EPT) was used to objectively determine baseline pulpal status of the affected tooth, followed by 2-minute interval testing following the administration of all local anesthesia. The onset of pulpal anesthesia was defined by the first of 2 consecutive EPT=80 readings, and the endodontic treatment could begin. Profound pulpal anesthesia was ultimately determined if the patient reported a comfortable pulpotomy as reflected on the Wong-Baker FACES Visual Analog Scale. Null Hypothesis 1: Subjects possessing mandibular molars diagnosed with symptomatic irreversible pulpitis will not achieve pulpal anesthesia more profoundly using buffered 2% lidocaine w/ 1:100,000 epinephrine in comparison to the standard, unbuffered anesthetic formulation. Null hypothesis 2: Subjects possessing mandibular molars diagnosed with symptomatic irreversible pulpitis will not achieve pulpal anesthesia faster using buffered 2% lidocaine w/ 1:100,000 epinephrine in comparison to the standard, unbuffered anesthetic formulation. Results: We observed a local anesthetic success rate of 45% in the buffered group, 70% in the unbuffered group, and ultimately 57.5% between both groups. The findings further indicate that the VAS scores after pulpotomy is significantly different between the 2 groups (p=0.019), with the unbuffered group having a more profound mean VAS score of 1.2 (as opposed to a buffered mean of 3.1). Regarding the time of onset for pulpal anesthesia, there was no statistically significant difference noted between the buffered and unbuffered groups. Conclusion: Based on the findings of this study, the null hypothesis 1 cannot be rejected since unbuffered 2% lidocaine with 1:100,000 epinephrine had a statistically significant increase in profound pulpal anesthesia compared to the buffered equivalent. The null hypothesis 2 cannot be rejected since there was no evidence of a significant difference in the time to pulpal anesthesia between the buffered and unbuffered groups.
133

Evaluation of Inhibitory Antibodies against the Muscarinic Acetylcholine Receptor Type 3 in Patients with Primary Biliary Cholangitis and Primary Sclerosing Cholangitis

Wilde, Anne-Christin Beatrice, Greverath, Lena Marie, Steinhagen, Lara Marleen, de Chamorro, Nina Wald, Leicht, Elise, Fischer, Janett, Herta, Toni, Berg, Thomas, Preuss, Beate, Klein, Reinhild, Tacke, Frank, Müller, Tobias 02 June 2023 (has links)
Background: Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) constitute rare chronic inflammatory biliary diseases which likely comprise genetic, environmental and autoimmune factors. Specific inhibitory (auto-) antibodies against the muscarinic acetylcholine receptor type 3 (mAChR3 auto-ab) may contribute to the pathogenesis of chronic biliary inflammation by modulating mAChR3− mediated signaling. Aims: The aim of this study was to analyze the prevalence and relevance of inhibitory mAChR3 auto-ab (mAChR3inh+ auto-ab) in a large cohort of PBC patients from two independent tertiary centers in Berlin and Leipzig in comparison to a large PSC cohort. Baseline parameters and response rates to standard treatment with ursodeoxycholic acid (UDCA) were characterized with respect to the individual mAChR3 auto-ab status. Methods: In total, the study population comprised 437 PBC patients, 187 PSC patients and 80 healthy controls. Clinical and laboratory baseline characteristics were retrieved from medical records. The response to ursodeoxycholic acid (UDCA) therapy after 12 months of treatment was available in 176 PBC and 45 PSC patients. Results: The prevalence of mAChR3inh+ auto-ab was significantly higher among PBC patients (11.2%, 49/437; p = 0.008 vs. healthy controls) and PSC patients (33.6%, 63/187; p < 0.0001 vs. healthy controls) compared to healthy controls (2.5%, 2/80), respectively. PBC patients with mAChR3inh+ auto-ab exhibited significantly higher levels of alkaline phosphatase (ALP) and bilirubin, which constitute established parameters for PBC risk stratification. Moreover, mAChR3inh+ PBC patients tended to show decreased response rates to UDCA therapy compared to PBC patients without mAChR3inh+ auto-ab (mAChR3− PBC). In contrast, PSC patients with mAChR3inh+ auto-ab showed no significant differences in laboratory findings compared to mAChR3 auto-ab negative (mAChR3−) PSC patients. Conclusion: MAChR3inh+ auto-ab might be involved in the pathogenesis and treatment response of chronic biliary inflammation in patients with PBC but not in patients with PSC.
134

New Advances in Capillary Electrophoresis for Biomonitoring in Population Health and Newborn Screening of Cystic Fibrosis

Mathiaparanam, Stellena January 2022 (has links)
Biological markers (i.e., biomarkers) are essential in clinical and epidemiological studies as they may provide mechanistic insights into the developmental origins of disease, as well as improve diagnostic testing and risk assessment for disease prevention. However, major challenges remain due to the lack of rapid yet selective analytical methods for high throughput screening that are also amenable to volume-restricted specimens. This thesis includes two major research themes that take advantage of capillary electrophoresis (CE) separations, including (1) the targeted analysis of urinary iodide and thiocyanate for assessment of nutritional adequacy and tobacco smoke exposures in the population, and (2) the discovery of new biomarkers in sweat specimens that may improve universal newborn screening programs for cystic fibrosis (CF) infants beyond impaired chloride transport. Chapter II examines the prevalence and risk factors associated with iodine deficiency in 24 h urine samples collected from 800 participants across four clinical sites in Canada as part of the Prospective Urban and Rural Epidemiological (PURE) study when using CE with UV detection in conjunction with sample self-stacking. Importantly, regional variations in iodine status were revealed with participants from Quebec City and Vancouver at greater risk for iodine deficiency than Hamilton and Ottawa. Overall, iodine supplement use, thyroxine prescription, urinary sodium excretion, and self-reported dairy intake were found to be protective factors against iodine deficiency. Chapter III applied a validated CE assay to measure urinary thiocyanate as a biomarker of tobacco smoke and dietary exposures in an international cohort of 1000 participants from the PURE study spanning 14 countries with varied income status, smoking habits, and diet quality. Current smokers residing in high-income countries had the highest extent of cyanide exposure indicative of greater harms from tobacco smoke compared to middle- and low-income countries after adjusting for smoking intensity and other covariates. Chapter IV introduces a rapid CE method with indirect UV detection to simultaneously measure sweat chloride and bicarbonate from presumptive CF infants’ residual sweat samples. Although bicarbonate did not provide clinical value in neonatal CF diagnosis, sweat chloride testing by CE may reduce test failure rates due to insufficient volumes from infants in a clinical setting. Lastly, Chapter V applied an untargeted strategy to characterize the sweat metabolome from presumptive CF infants when using multisegment injection-capillary electrophoresis-mass spectrometry (MSI-CE-MS). A panel of sweat metabolites were found to discriminate CF from non-CF (i.e., unaffected carriers) infants, including aspartic acid, glutamine, oxoproline, and pilocarpic acid, which also correlated with sweat chloride. The clinical utility of these sweat metabolites to prognosticate late-onset CF infants from indeterminate sweat chloride test results was also explored. In summary, this thesis contributes innovative separation methods for biomarker screening and discovery in clinical and epidemiological studies for the prevention and early treatment of human diseases that benefit from optimal nutrition. / Dissertation / Doctor of Philosophy (PhD)
135

EFFECTS OF ADDITIONAL SODIUM BICARBONATE ON EXTRA/INTRA CELLULAR FACTORS IN A CONTINUOUS FLOW BIOREACTOR FOR THE PRODUCTION OF TISSUE ENGINEERED ARTICULAR CARTILAGE

Khan, AASMA ARIF 31 October 2012 (has links)
Articular cartilage has a low propensity for self-repair, due to which 27 million people are affected by osteoarthritis every year in North America. The current repair techniques used for cartilage defects possess flaws that reduce long-term clinical success. Tissue engineering carries with it the promise of engineering hyaline-like cartilage with physical and biochemical properties, similar to that of native cartilage. This being said, the primary objective of my project was to engineer clinically relevant sized articular cartilage constructs. To achieve my objective, first, I investigated the effect of continuous culture on cartilaginous tissue growth. Constructs grown under continuous media flow significantly accumulated more collagen and glycosaminoglycan, and displayed a stratified morphology, similar to that found in native cartilage. The second goal was to further increase chondrocyte proliferation, and extracellular matrix (ECM) accumulation. To achieve this, constructs were grown in a bioreactor with media supplemented with 14 mM sodium bicarbonate (NaHCO3). Constructs cultivated in the bioreactor with NaHCO3 supplementation exhibited a significant (p<0.05) increase in ECM accumulation (a 98-fold increase in glycosaminoglycans and a 25-fold increase in collagen content), cell proliferation (a 13-fold increase), and thickness (a 28-fold increase) compared to all other conditions (static and reactor without NaHCO3 supplementation). The third goal was to engineer cartilage constructs with as little cells as possible, reducing donor site morbidity. From the results obtained, it was evident that the monolayer constructs outperformed all the other constructs (pellet, biopsy, and minced). The final goal was to understand the underlying reason for the increased proliferation. First, I investigated if there were any differences present in intracellular pH (pHi) and intracellular buffering capacity. Second, I determined the role of extracellular pH (pHe) on cell proliferation. In an effort to accurately achieve this, I, for the first time, have reported on measuring pHi of chondrocytes while still in culture (2D and 3D cultures) using a confocal microscope. This study demonstrated the importance of extracellular environments, such as pHe, extracellular buffering capacity, and the presence of carbon dioxide and bicarbonate ions for chondrocyte proliferation. / Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2012-10-30 19:19:32.026
136

Chemismus paleofluid z ložisek typu "orogenic gold": nové analytické přístupy a případové studie z Českého masívu / Paleofluid chemistry of orogenic gold deposits: novel analytical methods and case studies from the Bohemian Massif

Hrstka, Tomáš January 2012 (has links)
PALEOFLUID CHEMISTRY OF OROGENIC GOLD DEPOSITS: NOVEL ANALYTICAL METHODS AND CASE STUDIES FROM THE BOHEMIAN MASSIF Tomáš Hrstka1 1 Charles University in Prague, Faculty of Science, Institute of Geochemistry, Mineralogy and Mineral Resources, Albertov 6, Praha 2, CZ-128 43 Abstract of the Ph.D. Thesis Fluid inclusions represent a unique tool for understanding the processes leading to the formation of mineral deposits and fluid-rock interactions in general. Orogenic gold deposits in the central part of the Bohemian Massif (Libčice and Kasejovice deposits) were studied in order to provide a better understanding of their genesis. A multifaceted approach was adopted including a broad spectrum of micro-analytical methods. While traditional methods were used as the basis of this study (e.g., microthermometry, SEM and optical microscopy), the application and improvement/development of modern analytical methods (e.g., LA-ICP- MS and Raman spectroscopy) or introduction of alternative innovative techniques (CLSM, Nano- tomography, QEMSCAN) constituted a significant part of this study. This study reveals the importance of the HCO3 - species in hydrothermal fluids (i.e., >100 řC to ~350 řC). Previously, the prevalence of Cl- and other anions was reported for hydrothermal paleofluids and the majority of studies suggested...
137

Oxidation Processes: Experimental Study and Theoretical Investigations

Al Ananzeh, Nada 29 April 2004 (has links)
Oxidation reactions are of prime importance at an industrial level and correspond to a huge market. Oxidation reactions are widely practiced in industry and are thoroughly studied in academic and industrial laboratories. Achievements in oxidation process resulted in the development of many new selective oxidation processes. Environmental protection also relies mainly on oxidation reactions. Remarkable results obtained in this field contributed to promote the social image of chemistry which gradually changes from being the enemy of nature to becoming its friend and savior. This study dealt with two aspects regarding oxidation process. The first aspect represented an experimental study for the partial oxidation of benzene to phenol using Pd membrane in the gaseous phase. The second part was a theoretical study for some of the advanced oxidation process (AOPs) which are applied for contaminant destructions in polluted waters. Niwa and coworkers reported a one step catalytic process to convert benzene to phenol using Pd membrane. According to their work, this technique will produce a higher yield than current cumene and nitrous oxide based industrial routes to phenol. A similar system to produce phenol from benzene in one step was studied in this work. Results at low conversion of benzene to phenol were obtained with a different selectivity from the reported work. High conversion to phenol was not obtained using the same arrangement as the reported one. High conversion to phenol was obtained using a scheme different from the one reported by Niwa et al1. It was found that producing phenol from benzene is not related to Pd-membrane since phenol was produced by passing all reactants over a Pd catalyst. Within the studied experimental conditions, formation of phenol was related to Pd catalyst since Pt catalyst was not capable of activating benzene to produce phenol. Other evidence was the result of a blank experiment, where no catalyst was used. From this experiment no phenol was produced. A kinetic model for the advanced oxidation process using ultraviolet light and hydrogen peroxide (UV/H2O2) in a completely mixed batch reactor has been tested for the destruction of humic acid in aqueous solutions. Known elementary chemical reactions with the corresponding rate constants were taken from the literature and used in this model. Photochemical reaction parameters of hydrogen peroxide and humic acid were also taken from the literature. Humic acid was assumed to be mainly destroyed by direct photolysis and radicals. The rate constant for the HA- reaction was optimized from range of values in the literature. Other fitted parameters were the rate constant of direct photolysis of hydrogen peroxide and humic acid. A series of reactions were proposed for formation of organic byproducts of humic acid destruction by direct photolysis and radicals. The corresponding rate constants were optimized based on the best fit within the range of available published data. This model doesn't assume the net formation of free radicals species is zero. The model was verified by predicting the degradation of HA and H2O2 for experimental data taken from the literature. The kinetic model predicted the effect of initial HA and H2O2 concentration on the process performance regarding the residual fraction of hydrogen peroxide and nonpurgeable dissolved organic carbon (NPDOC). The kinetic model was used to study the effect of the presence of carbonate/bicarbonate on the rate of degradation of NPDOC using hydrogen peroxide and UV (H2O2/UV) oxidation. Experimental data taken from literature were used to test the kinetic model in the presence of carbonate/bicarbonate at different concentrations. The kinetic model was able to describe the trend of the experimental data. The kinetic model simulations, along with the experimental data for the conditions in this work, showed a retardation effect on the rate of degradation of NPDOC due to the presence of bicarbonate and carbonate. This effect was attributed to the scavenging of the hydroxyl radicals by carbonate and bicarbonate. A kinetic model for the degradation of methyl tert-butyl ether (MTBE) in a batch reactor applying Fenton's reagent (FeII/ H2O2) and Fenton-like reagent (Feo/ H2O2) in aqueous solutions was proposed. All of the rate and equilibrium constants for hydrogen peroxide chemistry in aqueous solutions were taken from the literature. Rate and equilibrium constants for ferric and ferrous ions reactions in this model were taken from the reported values in the literature, except for the rate constant for the reaction of ferric ions with hydrogen peroxide where it was fitted within the range that was reported in the literature. Rate constant for iron dissolution was also a fitted parameter. The mechanism of MTBE degradation by the hydroxyl radicals was proposed based on literature studies. The kinetic model was tested on available experimental data from the literature which involved the use of Fenton's reagent and Fenton-like reagent for MTBE degradation. The degradation of MTBE in Fenton's reagent work was characterized to proceed by two stages, a fast one which involved the reaction of ferrous ions with hydrogen peroxide (FeII/H2O2 stage) and another, relatively, slower stage which involved the reaction of ferric ions with hydrogen peroxide (FeIII/H2O2 stage). The experimental data of MTBE degradation in the FeII/H2O2 stage were not sufficient to validate the model, however the model predictions of MTBE degradation in the FeIII/H2O2 stage was good. Also, the model was able to predict the byproducts formation from MTBE degradation and their degradation especially methyl acetate, and tert-butyl alcohol. The effect of each proposed reaction on MTBE degradation and the byproducts formation and degradation was elucidated based on a sensitivity analysis. The kinetic model predicted the degradation of MTBE for Fenton-like reagent for the tested experimental data. Matlab (R13) was used to solve the set of ordinary nonlinear stiff differential equations that described rate of species concentrations in each advanced oxidation kinetic model. Niwa, S. et al., Science 295 (2002) 105
138

Caracterização de cultivares de feijão para pré- de grãos desidratados de cozimento rápido e processamento industrial / Characterization of bean cultivars for preprocessing of dehydrated quick-cooking grains and industrial canning

Schoeninger, Vanderleia 26 October 2015 (has links)
Made available in DSpace on 2017-07-10T19:24:03Z (GMT). No. of bitstreams: 1 Tese revisada_ (Vanderleia) 29 10 2015.pdf: 2119451 bytes, checksum: 2a331a8e454522cd4dc600544af51cd4 (MD5) Previous issue date: 2015-10-26 / Currently an alternative that meets the demands of the modern consumer is the industrial processing. Due to the necessity of scientific materials about beans industrial processing in the national literature, then the objective in the first stage of this work (Paper 1) was prepare a review about this topic. Were presented some concepts and details of the industrial processing, unit operations and quality parameters evaluated in canned beans. In sequence (Paper 2) were presented the results of the study that evaluated the adaptability of eight bean cultivars for industrial processing. Cultivars evaluated were by commercial Carioca class: BRS Perola, BRS Estilo, BRS Ametista e BRS Notável and also the Black class: IPR Uirapuru, BRS Campeiro, BRS Esteio and BRS Esplendor. First the physical parameters of the grains were evaluated: water content, measurement of the size, roundness, weight of 100 seeds, density, bulk density, apparent moisture ratio and color components. Then the beans were processed at an industry of canning, using cans with a capacity of 420 g, in which the samples were put without the use of soaking. For sauce was used water at a temperature of 75°C and the cooking process and sterilization was performed in a rotary retort. The quality parameters were evaluated in canned beans: total, net and drained weight, headspace, damage index, color, soluble solids and total solids in the sauce, texture, acidity and pH. Data were submitted to multivariate analysis: Principal Components and Hierarchical Clustering. As a result it was found that the Carioca class BRS Estilo differs from others due to low drained weight that contributed to the increase of total solids in the broth, with low hardness values, not adapting to the type of process used in this experiment. In Black class were observed similar quality characteristics between cultivars BRS Esplendor and IPR Uirapuru, and between BRS Campeiro and BRS Esteio, especially this last one by having smaller index of damaged grains after processing. Lastly, in the last work (Paper 3) was presented information about a different option of product by beans, the quick cooking dehydrated, pointing details of the processing and the performance of Brazilian bean varieties, as well as the technological quality of the final product. In the processing of quick-cooking dried beans was used a Central Composite Design (CCD) with two factors. The first factor was cultivar, evaluating BRS Pérola, BRS Madrepérola, BRS Estilo and IAPAR 81. The second factor was concentration of NaHCO3 used in soaking operation followed by drying of the beans. Were evaluated the parameters: cooking time, damage index and color difference in the processed product. It was found that the effects on these quality parameters are dependent upon the cultivar factor, because BRS Estilo and BRS Madrepérola stood out due to reduced cooking time and color difference when compared to BRS Pérola and IAPAR 81. For BRS Estilo cultivar the increased of NaHCO3 concentration in the soaking reduced significantly the cooking time, with lower rates of damage when compared to BRS Madrepérola. Finally, the information in this work intends to contribute with future research on this topic and therefore increase the bean consumption, whether in the form of an innovative product like the quick cooking dehydrated or as canned beans. / Atualmente uma alternativa alimentar que atende às demandas do consumidor moderno é o processamento industrial do feijão. Devido à necessidade de materiais científicos sobre processamento industrial do feijão na literatura nacional, objetivou-se na primeira etapa deste trabalho (Artigo 1) elaborar uma revisão de literatura sobre o tema. São apresentados alguns conceitos e detalhes do processamento industrial, das operações unitárias e dos parâmetros de qualidade avaliados no feijão enlatado. Na sequência (Artigo 2), apresentam-se os resultados do trabalho que avaliou a adaptabilidade de oito cultivares de feijão ao processamento industrial. Foram avaliados cultivares da classe comercial Carioca: BRS Pérola, BRS Estilo, BRS Ametista e BRS Notável; da classe Preto: IPR Uirapuru, BRS Campeiro, BRS Esteio e BRS Esplendor. Primeiramente, foram verificados os parâmetros físicos nos grãos: teor de água, aferição das dimensões, esfericidade, massa de 100 grãos, densidade, massa específica aparente, coeficiente de hidratação e componentes de cor. Em seguida, os grãos foram processados em uma indústria do setor, utilizando-se embalagens metálicas com capacidade de 420 g, nas quais as amostras foram acondicionadas sem o emprego de hidratação prévia. Como calda, utilizou-se água na temperatura de 75 °C e o processo de cozimento e esterilização foi realizado em autoclave rotativa. No feijão enlatado, avaliaram-se os parâmetros de qualidade: peso bruto, líquido e drenado, altura de headspace, índice de danos, cor, sólidos solúveis e sólidos totais no caldo, textura, acidez e pH. Os dados foram submetidos à análise multivariada: componentes principais e de agrupamento. Como resultado, verificou-se que, na classe Carioca, o cultivar BRS Estilo diferencia-se dos demais, devido ao baixo peso drenado que contribuiu para o aumento de sólidos totais no caldo, com baixos valores de dureza, não se adaptando ao tipo de processo utilizado neste experimento. Na classe Preto, observaram-se características de qualidade semelhantes entre BRS Esplendor e IPR Uirapuru, e entre BRS Esteio e BRS Campeiro, destacando-se esta última por apresentar menores índices de grãos danificados após o processamento. Por fim, no último trabalho (Artigo 3), apresentam-se informações sobre uma opção diferenciada de produto derivado do feijão, o desidratado de cozimento rápido, apontando-se detalhes sobre o processamento e a performance de diferentes cultivares brasileiros, assim como a qualidade tecnológica. No processamento do feijão desidratado de cozimento rápido foi empregado um delineamento composto central (DCC) com dois fatores. O primeiro fator foi cultivar, avaliando-se BRS Pérola, BRS Madrepérola, BRS Estilo e IAPAR 81; o segundo fator foi a concentração de NaHCO3 (bicarbonato de sódio) empregado na hidratação, seguida da secagem dos grãos. Foram avaliados os parâmetros tempo de cozimento, índice de dano e diferença de cor no produto processado. Verificou-se que os efeitos nos parâmetros de qualidade são dependentes do fator cultivar, visto que BRS Estilo e BRS Madrepérola destacaram-se devido ao menor tempo de cozimento e diferença de cor, quando comparados ao BRS Pérola e IAPAR 81. Para BRS Estilo, o aumento na concentração de NaHCO3 reduz significativamente o tempo de cozimento, com menor índice de dano quando comparado ao cultivar BRS Madrepérola. Por fim, com as informações presentes neste trabalho pretende-se contribuir com pesquisas futuras sobre o tema e dessa forma incrementar o consumo do feijão, seja na forma de um produto inovador como o desidratado de cozimento rápido ou na forma de enlatado.
139

Caracterização de cultivares de feijão para pré- de grãos desidratados de cozimento rápido e processamento industrial / Characterization of bean cultivars for preprocessing of dehydrated quick-cooking grains and industrial canning

Schoeninger, Vanderleia 26 October 2015 (has links)
Made available in DSpace on 2017-05-12T14:47:17Z (GMT). No. of bitstreams: 1 Tese revisada_ (Vanderleia) 29 10 2015.pdf: 2119451 bytes, checksum: 2a331a8e454522cd4dc600544af51cd4 (MD5) Previous issue date: 2015-10-26 / Currently an alternative that meets the demands of the modern consumer is the industrial processing. Due to the necessity of scientific materials about beans industrial processing in the national literature, then the objective in the first stage of this work (Paper 1) was prepare a review about this topic. Were presented some concepts and details of the industrial processing, unit operations and quality parameters evaluated in canned beans. In sequence (Paper 2) were presented the results of the study that evaluated the adaptability of eight bean cultivars for industrial processing. Cultivars evaluated were by commercial Carioca class: BRS Perola, BRS Estilo, BRS Ametista e BRS Notável and also the Black class: IPR Uirapuru, BRS Campeiro, BRS Esteio and BRS Esplendor. First the physical parameters of the grains were evaluated: water content, measurement of the size, roundness, weight of 100 seeds, density, bulk density, apparent moisture ratio and color components. Then the beans were processed at an industry of canning, using cans with a capacity of 420 g, in which the samples were put without the use of soaking. For sauce was used water at a temperature of 75°C and the cooking process and sterilization was performed in a rotary retort. The quality parameters were evaluated in canned beans: total, net and drained weight, headspace, damage index, color, soluble solids and total solids in the sauce, texture, acidity and pH. Data were submitted to multivariate analysis: Principal Components and Hierarchical Clustering. As a result it was found that the Carioca class BRS Estilo differs from others due to low drained weight that contributed to the increase of total solids in the broth, with low hardness values, not adapting to the type of process used in this experiment. In Black class were observed similar quality characteristics between cultivars BRS Esplendor and IPR Uirapuru, and between BRS Campeiro and BRS Esteio, especially this last one by having smaller index of damaged grains after processing. Lastly, in the last work (Paper 3) was presented information about a different option of product by beans, the quick cooking dehydrated, pointing details of the processing and the performance of Brazilian bean varieties, as well as the technological quality of the final product. In the processing of quick-cooking dried beans was used a Central Composite Design (CCD) with two factors. The first factor was cultivar, evaluating BRS Pérola, BRS Madrepérola, BRS Estilo and IAPAR 81. The second factor was concentration of NaHCO3 used in soaking operation followed by drying of the beans. Were evaluated the parameters: cooking time, damage index and color difference in the processed product. It was found that the effects on these quality parameters are dependent upon the cultivar factor, because BRS Estilo and BRS Madrepérola stood out due to reduced cooking time and color difference when compared to BRS Pérola and IAPAR 81. For BRS Estilo cultivar the increased of NaHCO3 concentration in the soaking reduced significantly the cooking time, with lower rates of damage when compared to BRS Madrepérola. Finally, the information in this work intends to contribute with future research on this topic and therefore increase the bean consumption, whether in the form of an innovative product like the quick cooking dehydrated or as canned beans. / Atualmente uma alternativa alimentar que atende às demandas do consumidor moderno é o processamento industrial do feijão. Devido à necessidade de materiais científicos sobre processamento industrial do feijão na literatura nacional, objetivou-se na primeira etapa deste trabalho (Artigo 1) elaborar uma revisão de literatura sobre o tema. São apresentados alguns conceitos e detalhes do processamento industrial, das operações unitárias e dos parâmetros de qualidade avaliados no feijão enlatado. Na sequência (Artigo 2), apresentam-se os resultados do trabalho que avaliou a adaptabilidade de oito cultivares de feijão ao processamento industrial. Foram avaliados cultivares da classe comercial Carioca: BRS Pérola, BRS Estilo, BRS Ametista e BRS Notável; da classe Preto: IPR Uirapuru, BRS Campeiro, BRS Esteio e BRS Esplendor. Primeiramente, foram verificados os parâmetros físicos nos grãos: teor de água, aferição das dimensões, esfericidade, massa de 100 grãos, densidade, massa específica aparente, coeficiente de hidratação e componentes de cor. Em seguida, os grãos foram processados em uma indústria do setor, utilizando-se embalagens metálicas com capacidade de 420 g, nas quais as amostras foram acondicionadas sem o emprego de hidratação prévia. Como calda, utilizou-se água na temperatura de 75 °C e o processo de cozimento e esterilização foi realizado em autoclave rotativa. No feijão enlatado, avaliaram-se os parâmetros de qualidade: peso bruto, líquido e drenado, altura de headspace, índice de danos, cor, sólidos solúveis e sólidos totais no caldo, textura, acidez e pH. Os dados foram submetidos à análise multivariada: componentes principais e de agrupamento. Como resultado, verificou-se que, na classe Carioca, o cultivar BRS Estilo diferencia-se dos demais, devido ao baixo peso drenado que contribuiu para o aumento de sólidos totais no caldo, com baixos valores de dureza, não se adaptando ao tipo de processo utilizado neste experimento. Na classe Preto, observaram-se características de qualidade semelhantes entre BRS Esplendor e IPR Uirapuru, e entre BRS Esteio e BRS Campeiro, destacando-se esta última por apresentar menores índices de grãos danificados após o processamento. Por fim, no último trabalho (Artigo 3), apresentam-se informações sobre uma opção diferenciada de produto derivado do feijão, o desidratado de cozimento rápido, apontando-se detalhes sobre o processamento e a performance de diferentes cultivares brasileiros, assim como a qualidade tecnológica. No processamento do feijão desidratado de cozimento rápido foi empregado um delineamento composto central (DCC) com dois fatores. O primeiro fator foi cultivar, avaliando-se BRS Pérola, BRS Madrepérola, BRS Estilo e IAPAR 81; o segundo fator foi a concentração de NaHCO3 (bicarbonato de sódio) empregado na hidratação, seguida da secagem dos grãos. Foram avaliados os parâmetros tempo de cozimento, índice de dano e diferença de cor no produto processado. Verificou-se que os efeitos nos parâmetros de qualidade são dependentes do fator cultivar, visto que BRS Estilo e BRS Madrepérola destacaram-se devido ao menor tempo de cozimento e diferença de cor, quando comparados ao BRS Pérola e IAPAR 81. Para BRS Estilo, o aumento na concentração de NaHCO3 reduz significativamente o tempo de cozimento, com menor índice de dano quando comparado ao cultivar BRS Madrepérola. Por fim, com as informações presentes neste trabalho pretende-se contribuir com pesquisas futuras sobre o tema e dessa forma incrementar o consumo do feijão, seja na forma de um produto inovador como o desidratado de cozimento rápido ou na forma de enlatado.
140

Associação entre carga ácida da dieta e bicarbonato sérico em portadores de doença renal crônica / Association between dietary acid load and serum bicarbonate in patients with chronic kidney disease

Angeloco, Larissa Rodrigues Neto 15 December 2017 (has links)
A acidose metabólica é um achado comum em pacientes portadores de Doença Renal Crônica (DRC). Acredita-se que a dieta pode afetar o equilíbrio ácidobase do corpo por meio do fornecimento de precursores ácidos ou de base. No entanto, os resultados inconclusivos apontados na literatura indicam que ainda são necessários estudos bem delineados para comprovar a existência dessa associação. O principal objetivo desse estudo foi determinar o potencial de carga ácida renal (PRAL) proveniente da dieta e avaliar a sua associação com o bicarbonato sérico (HCO3) em pacientes com DRC enquanto em suas dietas habituais. Associações do HCO3 com o gasto energético de repouso (GER) e com oxidações proteicas e lipícas também foram estudadas. Trata-se de um estudo transversal realizado com 100 pacientes distribuídos igualmente nos estágios 3 e 4 da DRC entre 20 e 69 anos. Avaliação do estado nutricional foi feita por meio da antropometria, registro alimentar e exames bioquímicos, o qual incluiu os produtos proteicos de oxidação avançada e os isoprostanos. O HCO3 foi determinado por meio da gasometria venosa. GER foi medido pela calorimetria indireta. O PRAL foi determinado por meio do registro alimentar usando um algoritmo que inclui dados dietéticos da ingestão de proteína, fósforo, magnésio, cálcio e potássio descritos por Remer e Manz (1995). Também foi feita a diferenciação no consumo de proteína animal e vegetal. A análise dos resultados foi feita em quartis de HCO3 para as variáveis GER e parâmetros de oxidação, o restante das análises foram feitas por quartis de PRAL. Para comparação das variações médias dos quartis foi utilizado o teste one-way ANOVA. A associação entre a estimativa do PRAL e o HCO3 foi avaliada por modelos de regressão linear ajustados. A maior parte dos nossos pacientes portadores de DRC encontravam-se com excesso de peso associado a um aumento da circunferência abdominal e da porcentagem de gordura corporal. A mediana do PRAL foi de 6,8 mEq/dia com uma variação entre -24 a 52 mEq/dia. O PRAL mais elevado foi associado com o HCO3 mais baixo de uma forma graduada (p < 0.02). Encontramos uma diferença de 2,07 mmol/L no HCO3 entre o primeiro e o último quartil, sendo o valor do último quartil de PRAL menor em relação ao primeiro. A proteína animal apresentou uma correlação inversa com o bicarbonato sérico. O GER e os marcadores de oxidação lipíca e proteica não apresentaram associações com os níveis de HCO3. Esses resultados reforçam a possibilidade de que dietas com alto teor de carga ácida podem desempenhar um papel relevante no equilíbrio ácidobase em pacientes portadores de DRC, além de consolidar o uso da carga ácida da dieta como uma abordagem diferencial e complementar às outras estratégias no tratamento dietético da DRC. / Metabolic acidosis is a common complication in patients with chronic kidney disease (CKD). Acid-inducing diets are believed to impact on acid-base balance. However, well-designed studies are still needed to prove the association between dietary acid load and serum bicarbonate. The main aim of this study was to calculate the potential renal acid load (PRAL) of selected, frequently consumed foods and to evaluate its association with serum bicarbonate (HCO3) in patients with CKD. Associations of HCO3 with resting energy expenditure (REE) and with protein and lipid oxidation were also studied. It is a cross-sectional study with 100 patients equally distributed in stages 3 and 4 of CKD between 20 and 69 years. Nutritional status was assessed by anthropometric measurements, 3-day food recall, biochemical analysis including advanced oxidation protein products and isoprostanes. Venous blood gases was used to measure HCO3. GER was measured by indirect calorimetry. PRAL was determined by food record using an algorithm that includes protein, phosphorus, magnesium, calcium and potassium intake described by Remer and Manz (1995). Dietary intake of animal and vegetable protein were also evaluate. For analysis, we used quartiles of HCO3 for GER and oxidation parameters and for the others variables we used quartilhes of PRAL. ANOVA one-way test was used to compare the mean of the quartiles. The association between PRAL and HCO3 was assessed by linear regression models. Most of the patients were overweight with increased waist circumference and body fat. The median PRAL was 6.8 mEq/day with a variation between -24 to 52 mEq/day. Higher PRAL was associated with lower serum bicarbonate in a graded fashion (P trend 0.02). Serum bicarbonate was 2.07 mEq/L lower among those in the highest compared with the lowest quartile of PRAL. Animal protein was inversely correlated with serum bicarbonate. REE and lipid and protein oxidation markers showed no association with HCO3 levels. These results reinforce the possibility that diets with high dietary acid load may play a relevant role in the acid-base balance in CKD patients. In addition to consolidating the use of PRAL as a differential and complementary approach to other strategies in the nutritional treatment of CKD.

Page generated in 0.0678 seconds