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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

A Comparison of Analytical Methods for Quantifying Denatured Whey Proteins and Their Correlation to Solubility

Allen, Michelle D 01 July 2010 (has links) (PDF)
Protein structure affects the bioactivity and functionality of whey protein ingredients in food systems. Bioactivity of whey proteins and their derivatives are highly dependent upon primary, secondary and tertiary structure. The degree of denaturation of whey proteins is an important factor for determining how whey protein ingredients will perform in a food system. Several analytical methods have been developed to quantify protein denaturation of whey proteins. The goal of this project was to use a variety of analytical methods to quantify whey protein denaturation and to evaluate the correlation of denaturation to the functionality of whey protein powders. The objective of the first series of experiments was to compare three different analytical methods to measure denaturation of whey proteins in liquid whey obtained by various methods of separation and with varying degrees of heat treatment. A split plot experimental design was used. Raw bovine milk was skimmed and liquid whey was separated from the skim milk at natural pH. Three separation methods: 1) centrifugation, 2) membrane filtration and 3) enzyme coagulation, made up the first split plot. Each sub-plot of liquid whey was then divided into three split plots to receive heat treatment. Heat treatments were no heat, 76°C for fifteen seconds and 85°C for three minutes. Each of the resulting nine treatment combinations was analyzed by 1) polyacrylamide gel electrophoresis, 2) bicinchoninic acid-soluble protein assay and 3) fluorescence spectroscopy to determine the amount of denatured protein in the liquid whey. Fluorescence spectroscopy was found to be the most sensitive and reliable method for detecting differences in structure due to denaturation, while native polyacrylamide gel electrophoresis was found to be the least sensitive method. The sample which received the centrifugal treatment of isolation with no heat was found to be the most undenatured in structure while the sample which received the enzyme treatment of isolation with high heat was found to be the most denatured in structure. The objective of the second series of experiments was to evaluate the effect of denaturation on whey protein solubility in dried whey protein powders. Solubility is one of the most important functional properties to consider when selecting a whey protein ingredient, especially for beverage systems. Processing parameters are often manipulated in efforts to improve solubility. The protein structures of whey are considered to have an effect on solubility. Specifically, the degree of denaturation of whey proteins is thought to play a role in solubility. In this experimental design, raw bovine milk was skimmed and pasteurized then enzyme-coagulated at natural pH to separate the whey. Liquid whey was then split into three aliquots and each received one of the following treatments: 1) mild heat/ freeze dry, 2) mild heat/spray dry and 3) high heat/spray dry. Heat treatment was applied to liquid whey prior to concentration. Heat treated whey was then concentrated and dried. Powders were reconstituted and analyzed for denaturation using 1) bicinchoninic acid assay for soluble protein and 2) fluorescence spectroscopy and for solubility using an insolubility index. pH 4.6 solubility and fluorescence spectroscopy for quantifying denaturation correlated well to one another. Both found that the low heat treated samples were less denatured in structure than the sample which received the high heat treatment, regardless of drying method. However, the drying method of the protein powders was correlated to solubility rather than heat treatment. A correlation of denaturation measured in whey protein powders and solubility was apparent for the low heat, freeze dried sample and the high heat, spray dried sample. Several conclusions were made in this research. 1) Centrifugal force causes less denaturation than membrane filtration and enzyme coagulation, thus unheated liquid whey obtained by centrifugal force can be used as a control in research on denaturation. 1) Fluorescence spectroscopy is a better method for quantifying denaturation in liquid and powdered whey compared to native PAGE and pH 4.6 solubility measured by BCA. 3) Functional solubility is dependent on denaturation and can be correlated to analytical methods of measuring denaturation.
2

Relativní abundance patatinu ve vztahu k antioxidativní kapacitě hlíz vybrané skupiny kulturních a planých druhů brambor / Patatin proteins relative abundance in correlation to antioxidative activity of tubers of cultivated and wild potato species

MEJZLÍK, Petr January 2015 (has links)
The aim of the thesis was to determine the content of pure tuber proteins, patatin relative abundance in total tuber protein, and subsequently its antioxidant potential. The theoretical part dealt with general potato characteristics, potato tuber chemical composition and description of analyzed cultivated and wild potato species. In the practical part results of laboratory analysis were presented. It was determined statistically significant genotype variability of antioxidant activity for potato tuber protein as well as for potato tuber dry matter here ranging from 0.221 (Solanum berthaultii 07S0300031) to 0.0066 mg of ascorbic acid/g dry matter (Solanum tuberosum cultivar Kuras). Any direct relationship between potato tuber protein content or patatin relative abundance and antioxidant activity was found. The findings are compared with the literature.
3

Hodnocení transfekce nukleových kyselin v in vitro podmínkách. / IN VITRO assays for investigating nucleic acid delivery.

Mihaličoková, Dajana January 2018 (has links)
Charles University, Faculty of Pharmacy in Hradec Králové, Department of Biochemical Sciences University of Vienna, Faculty center for Pharmacy, Department of Pharmaceutical Chemistry, Laboratory of MacroMolecular Cancer Therapeutics Candidate: Dajana Mihaličoková Supervisor (Charles University): PharmDr. Anna Jirkovská, Ph.D. Supervisor (University of Vienna): Univ.Prof. Dipl. Ing. Dr. Manfred Ogris Co-supervisor (University of Vienna): Dr. Haider Sami, Ph.D. Title of diploma thesis: In vitro assays for investigating nucleic acid assay Keywords: transfection, splice correction, BCA assay, polyplexes One of the most important tasks of biochemical research is to find out the right way how to cure cancer, genetic disorders and other illnesses which are still not curable. Towards this, gene therapy is emerging as a potential treatment owing to its ability to deliver genetic material inside the cell. Reporer gene based transfection process can be used to study gene expression. Transfection is mediated by vectors, either of viral or non-viral origin. Non-viral vectors offer several advantages over the viral counterparts like easier to synthesize, relatively cheap and the most important is their non-immunogenicity. Cationic polymers based on polyethylenimine form complexes with plasmid DNA reffered to as...
4

Záchyt submikroskopických aberací u fenotypově abnormálních nosičů zjevně balancovaných chromozomových přestaveb metodou array CGH / Detection of submicroscopic chromosomal aberrations in phenotypically abnormal carriers of apparently balanced rearrangements using array CGH

Slámová, Zuzana January 2020 (has links)
Carriers of apparently balanced chromosomal aberrations (BCA) are usually phenotypically normal. However, it has been estimated that up to 27% of these BCA may be associated with an abnormal phenotype, most often caused by cryptic imbalances at the breakpoints, gene disruption by the breakpoint or via the position effect. In contrast to conventional karyotyping, molecular cytogenetic techniques enable more detailed BCA characterization and better correlation between genotype and phenotype of the patient. The aim of this thesis was to evaluate the presence of copy number variants (CNVs) at breakpoints or elsewhere in the genome in patients with abnormal phenotype who carry de novo or inherited BCA. 54 BCA were investigated using array CGH (20 de novo cases, 27 inherited and 7 cases of unknown origin) including 32 reciprocal translocations, 6 robertsonian translocations, 12 inversions and 4 complex chromosomal rearrangements. If possible, the parents were also examined to ascertain the inheritance of the relevant CNVs. In order to specify microarray findings or exclude gene disruption, FISH was used in selected patients. Among the patients included, in 31,5% (17/54) at least one (in 8 patients more than one) significant CNV was detected. Four cases carried cryptic imbalances only at the breakpoints,...
5

Unilateral Environmental Policy and Offshoring

Bolz, Simon J., Naumann, Fabrice, Richter, Philipp M. 06 May 2024 (has links)
Expanding on a general equilibrium model of offshoring, we analyze the effects of a unilateral emissions tax increase on the environment, income, and inequality. Heterogeneous firms allocate labor across production tasks and emissions abatement, while only the most productive can benefit from lower labor and/or emissions costs abroad and offshore. We find a non-monotonic effect on global emissions, which decline if the initial difference in emissions taxes is small. For a sufficiently large difference, global emissions rise, implying emissions leakage of more than 100%. The underlying driver is a global technique effect: While the emissions intensity of incumbent non-offshoring firms declines, the cleanest firms start offshoring. Moreover, offshoring firms become dirtier, induced by a reduction in the foreign effective emissions tax in general equilibrium. Implementing a BCA prevents emissions leakage, reduces income inequality in the reforming country, but raises inequality across countries.
6

Ciclobutanonas em ração canina após o processamento por radiação ionizante / Cyclobutanones in dog feed after ionizing radiation processing

Campos, Alexsandra Maria de 17 November 2017 (has links)
O segmento Pet, no agronegócio, está relacionado ao desenvolvimento das atividades de criação, produção e comercialização de animais de estimação. Este mercado cresceu 7,6% entre 2014/2015, gerou R$ 18 milhões no Brasil e 67,3% desse valor refere-se a produtos para alimentação animal, comumente chamados de Pet Food. Na alimentação animal, o alimento pode ser um único ingrediente ou uma formulação elaborada. Os ingredientes são categorizados em proteínas, carboidratos, fibras, gorduras, vitaminas e minerais. Eles são selecionados considerando os seguintes aspectos: disponibilidade, níveis de nutrientes, funcionalidade, palatabilidade, digestibilidade, custo e segurança. As matérias-primas são escolhidas de acordo com o (s) método (s) de processamento (s) em que o produto passa, sua estabilidade no processo e sua fonte nutricional durante a validade do produto. Na preservação de alimentos, o processo de irradiação é um tratamento que busca reduzir a carga microbiana dos mesmos. No entanto, também pode alterar a composição dos ingredientes presentes e formar produtos radiolíticos na formulação que ainda estão em estudo. Nos alimentos, as gorduras atuam como aporte de ácidos graxos essenciais são palatabilizantes e uma fração energética importante das rações. Nos produtos que contêm a presença de gordura, a principal preocupação são as 2-Alcilciclobutanonas (2-ACBs), que são produtos radiolíticos formados exclusivamente pós-processamento com radiação ionizante. A formação de 2- ACBs está diretamente relacionada à concentração lipídica e à dose de irradiação. O objetivo deste trabalho é descrever os possíveis subprodutos radiolíticos formados em rações caninas extrusadas contendo gordura após irradiação e determinar se a formação de 2-ACBs depende do aumento da dose de radiação, assim como , verificar sua citotoxicidade e genotoxicidade em cães. / In agribusiness, the Pet segment is related to the development of the activities of creation, production and commercialization of pet food. This market grew 7.6% between 2014/2015, generated R$ 18 million in Brazil and 67.3% of this amount refers to products for animal feed, commonly called pet food. In animal nutrition the food may be a single ingredient or an elaborate formulation. Ingriedients are categorized into proteins, carbohydrates, fiber, fat, vitamins and minerals. They are selected considering the following aspects: availability, nutrient levels, functionality, palatability, digestibility, cost and safety. The raw materials are chosen according to the method (s) of processing (s) in which the product is submit, its stability in the process and its nutritional source during the validity of the product. In food preservation the irradiation process is a treatment that seeks to reduce the microbial load of the food. However, it can also alter the composition of the ingredients present and form radiolytic products in the formulation that are still under study. In foods, fats act as a contribution of essential fatty acids are palatabilizing and an important energetic fraction of the rations. In products containing the presence of fat, the main concern are 2- alkylcyclobutanones (2-ACBs), which are radiolytic products formed exclusively post-processing with ionizing radiation. The formation of 2-ACBs is directly related to the lipid concentration and the dose of irradiation. The objective of this work is to describe the possible radiolytic by-products formed in extruded fat-containing canine rations after irradiation and to determine if the formation of 2-ACBs is dependent on the radiation dose, and as well as verify their cytotoxicity and genotoxicity.
7

Ciclobutanonas em ração canina após o processamento por radiação ionizante / Cyclobutanones in dog feed after ionizing radiation processing

Alexsandra Maria de Campos 17 November 2017 (has links)
O segmento Pet, no agronegócio, está relacionado ao desenvolvimento das atividades de criação, produção e comercialização de animais de estimação. Este mercado cresceu 7,6% entre 2014/2015, gerou R$ 18 milhões no Brasil e 67,3% desse valor refere-se a produtos para alimentação animal, comumente chamados de Pet Food. Na alimentação animal, o alimento pode ser um único ingrediente ou uma formulação elaborada. Os ingredientes são categorizados em proteínas, carboidratos, fibras, gorduras, vitaminas e minerais. Eles são selecionados considerando os seguintes aspectos: disponibilidade, níveis de nutrientes, funcionalidade, palatabilidade, digestibilidade, custo e segurança. As matérias-primas são escolhidas de acordo com o (s) método (s) de processamento (s) em que o produto passa, sua estabilidade no processo e sua fonte nutricional durante a validade do produto. Na preservação de alimentos, o processo de irradiação é um tratamento que busca reduzir a carga microbiana dos mesmos. No entanto, também pode alterar a composição dos ingredientes presentes e formar produtos radiolíticos na formulação que ainda estão em estudo. Nos alimentos, as gorduras atuam como aporte de ácidos graxos essenciais são palatabilizantes e uma fração energética importante das rações. Nos produtos que contêm a presença de gordura, a principal preocupação são as 2-Alcilciclobutanonas (2-ACBs), que são produtos radiolíticos formados exclusivamente pós-processamento com radiação ionizante. A formação de 2- ACBs está diretamente relacionada à concentração lipídica e à dose de irradiação. O objetivo deste trabalho é descrever os possíveis subprodutos radiolíticos formados em rações caninas extrusadas contendo gordura após irradiação e determinar se a formação de 2-ACBs depende do aumento da dose de radiação, assim como , verificar sua citotoxicidade e genotoxicidade em cães. / In agribusiness, the Pet segment is related to the development of the activities of creation, production and commercialization of pet food. This market grew 7.6% between 2014/2015, generated R$ 18 million in Brazil and 67.3% of this amount refers to products for animal feed, commonly called pet food. In animal nutrition the food may be a single ingredient or an elaborate formulation. Ingriedients are categorized into proteins, carbohydrates, fiber, fat, vitamins and minerals. They are selected considering the following aspects: availability, nutrient levels, functionality, palatability, digestibility, cost and safety. The raw materials are chosen according to the method (s) of processing (s) in which the product is submit, its stability in the process and its nutritional source during the validity of the product. In food preservation the irradiation process is a treatment that seeks to reduce the microbial load of the food. However, it can also alter the composition of the ingredients present and form radiolytic products in the formulation that are still under study. In foods, fats act as a contribution of essential fatty acids are palatabilizing and an important energetic fraction of the rations. In products containing the presence of fat, the main concern are 2- alkylcyclobutanones (2-ACBs), which are radiolytic products formed exclusively post-processing with ionizing radiation. The formation of 2-ACBs is directly related to the lipid concentration and the dose of irradiation. The objective of this work is to describe the possible radiolytic by-products formed in extruded fat-containing canine rations after irradiation and to determine if the formation of 2-ACBs is dependent on the radiation dose, and as well as verify their cytotoxicity and genotoxicity.
8

Ion beam processing of surfaces and interfaces – Modeling and atomistic simulations

Liedke, B. 14 March 2012 (has links) (PDF)
Self-organization of regular surface pattern under ion beam erosion was described in detail by Navez in 1962. Several years later in 1986 Bradley and Harper (BH) published the first self-consistent theory on this phenomenon based on the competition of surface roughening described by Sigmund’s sputter theory and surface smoothing by Mullins-Herring diffusion. Many papers that followed BH theory introduced other processes responsible for the surface patterning e.g. viscous flow, redeposition, phase separation, preferential sputtering, etc. The present understanding is still not sufficient to specify the dominant driving forces responsible for self-organization. 3D atomistic simulations can improve the understanding by reproducing the pattern formation with the detailed microscopic description of the driving forces. 2D simulations published so far can contribute to this understanding only partially. A novel program package for 3D atomistic simulations called trider (TRansport of Ions in matter with DEfect Relaxation), which unifies full collision cascade simulation with atomistic relaxation processes, has been developed. The collision cascades are provided by simulations based on the Binary Collision Approximation, and the relaxation processes are simulated with the 3D lattice kinetic Monte-Carlo method. This allows, without any phenomenological model, a full 3D atomistic description on experimental spatiotemporal scales. Recently discussed new mechanisms of surface patterning like ballistic mass drift or the dependence of the local morphology on sputtering yield are inherently included in our atomistic approach. The atomistic 3D simulations do not depend so much on experimental assumptions like reported 2D simulations or continuum theories. The 3D computer experiments can even be considered as ’cleanest’ possible experiments for checking continuum theories. This work aims mainly at the methodology of a novel atomistic approach, showing that: (i) In general, sputtering is not the dominant driving force responsible for the ripple formation. Processes like bulk and surface defect kinetics dominate the surface morphology evolution. Only at grazing incidence the sputtering has been found to be a direct cause of the ripple formation. Bradley and Harper theory fails in explaining the ripple dynamics because it is based on the second-order-effect ‘sputtering’. However, taking into account the new mechanisms, a ‘Bradley-Harper equation’ with redefined parameters can be derived, which describes pattern formation satisfactorily. (ii) Kinetics of (bulk) defects has been revealed as the dominating driving force of pattern formation. Constantly created defects within the collision cascade, are responsible for local surface topography fluctuation and cause surface mass currents. The mass currents smooth the surface at normal and close to normal ion incidence angles, while ripples appear first at θ ≥ 40°. The evolution of bimetallic interfaces under ion irradiation is another application of trider described in this thesis. The collisional mixing is in competition with diffusion and phase separation. The irradiation with He+ ions is studied for two extreme cases of bimetals: (i) Irradiation of interfaces formed by immiscible elements, here Al and Pb. Ballistic interface mixing is accompanied by phase separation. Al and Pb nanoclusters show a self-ordering (banding) parallel to the interface. (ii) Irradiation of interfaces by intermetallics forming species, here Pt and Co. Well-ordered layers of phases of intermetallics appear in the sequence Pt/Pt3Co/PtCo/PtCo3/Co. The trider program package has been proven to be an appropriate technique providing a complete picture of mixing mechanisms.
9

Bio-BCA (Bio-Barcode Cascade Amplification) : development of a photosensitive, DNA-based exponential amplification platform technology for the detection of nucleic acid biomarkers

Lehnus, Massimiliano January 2018 (has links)
No description available.
10

Aproveitamento sustent?vel do baga?o de cana de a??car para obten??o do acetato de celulose

Silva, Valdic Luiz da 15 August 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-14T18:51:54Z No. of bitstreams: 1 ValdicLuizDaSilva_DISSERT.pdf: 3002851 bytes, checksum: a27175bc5e66f1e203ed3d2f6e60d562 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-15T19:22:11Z (GMT) No. of bitstreams: 1 ValdicLuizDaSilva_DISSERT.pdf: 3002851 bytes, checksum: a27175bc5e66f1e203ed3d2f6e60d562 (MD5) / Made available in DSpace on 2016-01-15T19:22:11Z (GMT). No. of bitstreams: 1 ValdicLuizDaSilva_DISSERT.pdf: 3002851 bytes, checksum: a27175bc5e66f1e203ed3d2f6e60d562 (MD5) Previous issue date: 2014-08-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / O aproveitamento sustent?vel de res?duos decorrente da agroind?stria ? atualmente foco de pesquisas, com destaque para o baga?o de cana de a??car (BCA), por ser o res?duo lignocelul?sico produzido em maior volume na agroind?stria brasileira, onde a biomassa residual tem sido aplicada na produ??o de energia el?trica e bioprodutos. Neste trabalho, foi produzida celulose com elevada pureza, a partir do (BCA), por polpa??o soda/antraquinona e, posterior convers?o em acetato de celulose. A celulose comercial Avicel foi utilizada para compara??o. A obten??o do acetato de celulose ocorreu por rea??o de acetila??o homog?nea, modificando-se as vari?veis, tempo reacional, em horas, (8, 12, 16, 20 e 24) e temperatura, em ?C, (25 e 50). Os espectros de FTIR indicaram bandas caracter?sticas id?nticas para os materiais celul?sicos, o que demonstra a efici?ncia da separa??o por polpa??o. A caracteriza??o da celulose e do acetato obtidos ocorreu por espectroscopia de infravermelho (FTIR), difra??o de raios X (DRX), an?lises termogravim?tricas (TG/DTG/DSC), microscopia eletr?nica de varredura (MEV) e determina??o do grau de substitui??o (GS) para o acetato de celulose, para confirma??o da acetila??o. Os tempos reacionais ?timos para a obten??o de diacetatos e triacetatos, em ambas as temperaturas foram 20 h e 24 h. O acetato de celulose, produzido do BCA, apresentou GS entre 2,57 e 2,7 na temperatura de 25?C e, a 50 ?C, os GS obtidos foram 2,66 e 2,84, indicando real convers?o da celulose do BCA em di e triacetatos. De modo comparativo, a celulose comercial Avicel apresentou GS de 2,78 e 2,76 a 25 ?C e 2,77 e 2,75 a 50 ?C. Os dados foram obtidos no tempo de 20 h e 24 h, respectivamente. O melhor resultado ocorreu para a s?ntese do acetato de celulose obtida do BCA, com GS de 2,84 a 50?C e 24 h, sendo classificado como triacetato de celulose, que apresentou resultado superior ao acetato produzido com a celulose comercial Avicel, demonstrando a potencialidade de convers?o da celulose obtida a partir de um res?duo lignocelul?sicos (BCA), de baixo custo, com perspectivas de utiliza??o comercial do acetato de celulose / The sustainable use of waste resulting from the agribusiness is currently the focus of research, especially the sugar cane bagasse (BCA), being the lignocellulosic waste produced in greater volume in the Brazilian agribusiness, where the residual biomass has been applied in production energy and bioproducts. In this paper, pulp was produced in high purity from the (BCA) by pulping soda / anthraquinone and subsequent conversion to cellulose acetate. Commercial cellulose Avicel was used for comparison. The obtained cellulose acetate was homogeneous acetylation reaction by modifying the variables, the reaction time in hours (8, 12, 16, 20 and 24) and temperature in ? C (25 and 50). FTIR spectra showed characteristic bands identical to cellulosic materials, demonstrating the efficiency of separation by pulping. The characterization of cellulose acetate was obtained and by infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TG / DTG / DSC), scanning electron microscopy (SEM) and determining the degree of substitution (DS ) for the cellulose acetate to confirm the acetylation. The optimal reaction time for obtaining diacetates and triacetates, at both temperatures were 20 and 24 h. Cellulose acetate produced BCA presented GS between 2.57 and 2.7 at 25 ? C and 50 ? C GS obtained were 2.66 and 2.84, indicating the actual conversion of cellulose BCA of di- and triacetates. Comparative mode, commercial cellulose Avicel GS showed 2.78 and 2.76 at 25 ? C and 2.77 to 2.75 at 50 ? C. Data were collected in time of 20 h and 24 h, respectively. The best result was for the synthesis of cellulose acetate obtained from the BCA GS 2.84 to 50 ? C and 24 hours, being classified as cellulose triacetate, which showed superior result to that produced with the commercial ethyl cellulose Avicel, demonstrating converting potential of cellulose derived from a lignocellulosic residue (BCA), low cost, prospects of commercial use of cellulose acetate

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