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Thesis (Ph. D.)--University of Wisconsin--Madison, 1946. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 96-100).

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Cowpea (Vigna unguiculata L. Walp) is an important legume mainly used for human consumption worldwide, particularly in developing countries. Cowpea legume is rich in protein (25%), carbohydrates (70%), dietary fibre, minerals and vitamins. Cowpea comprises a range of varieties that breeders release based primarily on agronomic characteristics, such as yield, early maturity and drought tolerance. However, consumers do not always adopt all the released cowpea varieties. Cooking characteristics such as cooking time and sensory properties (i.e. appearance, texture, flavour) of cooked cowpeas are believed to be quality characteristics for legume acceptability by consumers. Physicochemical characteristics are known to influence cooking characteristics of cowpeas. These characteristics may be influenced by seed coat and cotyledon structure. The present study focuses on the effect of seed coat and cotyledon structure on cooking and sensory characteristics of cowpeas and how this in turn influences consumer acceptability of cowpeas. The influence of seed coat thickness and cotyledon compactness on cooking characteristics of four cowpea types (thick seed coat/compact cotyledon (Bechuana White), thick seed coat/porous cotyledon (IT82E 18), thin seed coat/compact cotyledon (Black Eye) and thin seed coat/porous cotyledon (California Black) was studied. Seed coat thickness was found to influence water absorption during soaking. Cowpeas with thin seed coats had higher rates of water absorption during soaking due to its amorphous cell layer that rendered the seed coat more permeable compared to the palisade cell layer found in cowpeas with thick seed coats. Cotyledon compactness influenced cooking time of cowpeas. Cowpeas with porous cotyledons cooked faster compared to cowpeas with compact cotyledon probably because of the structural arrangement of porous cotyledon cells that provide more intercellular spaces for rapid water entry, cell expansion and separation favouring a faster cooking process compared to compact cotyledon. Seed coat and cotyledon structures directly influenced very few of the cooking and sensory characteristics. Sensory attributes such as cooked cowpea flavour, degree of sweetness, degree of sweet aftertaste, and degree of mushiness positively contributed to consumers’ liking of cowpeas. Raw cowpea flavour, bitter taste, degree of bitter aftertaste and degree of firmness contributed to consumers’ disliking of cowpeas. Chemical composition of cowpeas probably influences sensory characteristics of cowpeas more than seed coat and cotyledon structures. It is recommended that breeders work together with food scientists in order to release cowpeas types that are preferred by consumers (i.e. cowpeas with good appearance (low percentage of splitting), good flavour and soft texture upon cooking. Please cite as follows: Penicela, L 2010, The influence of seed coat and cotyledon structure on cooking characteristics of cowpeas, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-06292011-154445/ > E11/438/gm / Dissertation (MSc)--University of Pretoria, 2010. / Food Science / unrestricted

Orientador: Antonio Marsaioli Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T16:21:01Z (GMT). No. of bitstreams: 1 Vilalba_FabiodeAlbuquerque_M.pdf: 570013 bytes, checksum: 8f4e3f0349848d620390519a1dc8eee4 (MD5) Previous issue date: 2003 / Resumo: O cupuaçu (Theobroma grandiflorum) é uma fruta nativa da região amazônica Brasileira cujas sementes convenientemente fermentadas, secas e torradas podem ser utilizadas para a obtenção de um produto similar ao chocolate. Uma etapa deste processo deverá também envolver, portanto, a obtenção dos nibs (cotilédones fragmentados) das amêndoas secas, separando-o da casca e do gérmen, o que pode ser feito antes ou após a torração. Esta fase do processamento da amêndoa é, ainda, realizada manualmente, de modo totalmente artesanal e pouco eficiente. O objetivo deste trabalho consistiu em pesquisar uma forma alternativa de quebra da amêndoa seca sem torrar, realizada através de um beneficiador de cilindros, seguida da utilização de um jogo de peneiras para a separação das frações. Os fatores estudados no rendimento da obtenção dos nibs e na verificação de sua pureza (percentual de casca e gérmen) foram a umidade da amêndoa inteira e a velocidade diferencial do par de cilindros de borracha do beneficiador, sendo este último a diferença das velocidades tangenciais destes cilindros. Os valores estudados das umidades foram de 5, 6 e 7%. O fator velocidade diferencial foi estudado em duas faixas, a primeira com 2,10 , 2,66 e 3,23m/s e, a segunda, com 0,84 , 1,87 e 3,23m/s. Pelos resultados obtidos, foi verificado que a variável umidade apresenta a maior influência na quebra das amêndoas. O nível de umidade de 5% da amêndoa inteira apresentou os maiores rendimentos de obtenção de nibs. A velocidade diferencial não apresentou diferença significativa nos rendimentos. Em relação aos valores dos percentuais de casca e gérmen nos nibs, nenhuma variável em estudo apresentou influência significativa nos valores desta resposta, mesmo assim todos os resultados foram bastante satisfatórios. Os percentuais de casca e gérmen encontrados no material final (nibs) foram inferior a 1,75%. O rendimento deste processo alternativo está em torno de 90% de obtenção dos cotilédones encontrados em uma determinada massa de amêndoas. Concluindo, o processo proposto constitui uma alternativa mecanizada, tecnicamente válida e superior aos métodos artesanais, apresentando bom rendimento de recuperação dos nibs, com percentuais de casca e gérmen abaixo do tolerado / Abstract: Cupuassu (Theobroma grandiflorum) is a native fruit from the Brazilian Amazon region whose seeds suitably fermented, dried and roasted can be used to manufacture a product similar to chocolate. One phase of this process must also include, therefore, the extraction of nibs (scrapped cotyledons) from the dried kernels, separating it from the shells, what can be done before or after roasting. This part of processing the kernels is still done through manual operation, in an inefficient artisan way. This work aims at devising an alternative way of cracking the dried but not roasted kernels by using a roller crusher, followed by sieving for separating the fractions. The variables studied for determining the nibs acquisition yield as well the purity of such material (expressed as percentage of shell and embryo fragments) were the moisture of the whole kernel and the differential speed of the double rollers of the crusher, this last is the difference of the tangential speeds of those rollers. The studied values of the moisture were 5, 6 e 7%. The factor differential speed was studied in two bands, the first with 2.10 , 2.66 e 3.23m/s, the second with 0.84 , 1.87 e 3.23m/s. The results confirmed that the moisture of the whole kernel was the variable that most influenced the cracking of the kernels. The moisture level of 5% of the whole kernels showed greater yield obtainment of nibs. The variation of the differential speed did not present any significant difference at yield. With regard to the percentage values of shell and embryo found in nibs, the variables considered did not show any significant difference on the response parameter, although the results were very much satisfactory. The percentage of shell and embryo found in the final material (nibs) is below the 1.75%. The yield of this alternative process is 90% of the cotyledons acquisition from certain kernels mass. In conclusion, the proposed process sets up as a mechanized alternative, of technical value and superior to the artisan methods, showing good nibs acquirement yield, and percentage of shells and embryo below the tolerated. / Mestrado / Mestre em Engenharia de Alimentos

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21250号 / 理博第4420号 / 新制||理||1634(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 長谷 あきら, 教授 鹿内 利治, 准教授 小山 時隆 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

Cell dedifferentiation is a cell fate switching process in which a differentiated cell reverts to a status with competence for cell division and organ regeneration like an embryonic stem cell. Although the phenomenon of cell dedifferentiation has been known for over two and a half centuries in plants, little is known of the underlying mechanisms. Here, the proteome map of Arabidopsis cotyledons has been established and investigated the dynamic change of the cotyledon proteome in the time course of cell dedifferentiation. Among the 353 distinct genes, corresponding to 500 2-DE gel protein spots identified with high confidence, 12% have over twofold differential regulations within the first 48 h of induction of cell dedifferentiation. The distributions of these genes among different Gene Ontology categories and gene differential regulations within each of the categories have been examined. In addition, the cotyledon phosphoproteome has been investigated using Pro-Q Diamond Phosphoprotein in Gel Stain followed by mass spectrometry analyses. Among the 53 identified putative phosphoproteins, nine are differentially regulated during cell dedifferentiation. Arabidopsis cotyledon proteome at four different time points after the induction of cell dedifferentiation with MudPIT approach has been investigated and analyzed the protein quantity change using two labelree methods, the Spectral Count (SC) and SEQUEST Cross Correlation Coefficient (ÓXcorr) methods. Among the 662 MudPIT identified proteins, one hundred forty eight displayed differential regulation. The up-regulated proteins include transcription factors, calmodulins, translational regulators, and stress response proteins. The Spectral Count and the cross correlation coefficient quantification results are highly consistent in over 81% of the differentially regulated proteins. These studies have provided significant new insight into cell dedifferentiation process in Arabidopsis thaliana and also enhanced the Arabidopsis cotyledon proteome database established using gel based and non gel based methods. The results show that cell dedifferentiation involves extensive protein quantitative and qualitative changes in almost every cellular compartment and cellular process. Proteins like 14-3-3 proteins, Translational controlled tumor protein (TCTP) and its possible interaction protein-Translational elongation factor eEF1 alpha chain, GTP binding nuclear protein RAN2, GTP binding protein SAR1B and several other hypothetical and expressed proteins and nine other phosphoproteins showed significant differential expression during early dedifferentiation. Deciphering the molecular mechanisms regulating the cellular dedifferentiation certainly enhances the understandings and mechanisms of reprogramming all types of differentiated cells including animal cells.

Les femmes enceintes sont exposées à de nombreux médicaments et les essais cliniques sont difficilement réalisables dans cette population, c'est pourquoi avoir une méthode qui permet d'estimer l'ampleur des modifications de pharmacocinétique chez la femme enceinte et le passage transplacentaire est essentiel. En effet les modifications physiologiques prennent place durant cette période clé. Nous avons développé des modèles pharmacocinétiques basé sur la physiologie (PBPK) et intégré les modifications physiologiques connues survenant durant la grossesse. Ils décrivent bien la pharmacocinétique de 3 antirétroviraux éliminés par le rein, le ténofovir (TFV), l'emtricitabine (FTC) et la lamivudine (3TC) et d'une molécule métabolisée par le CYP3A4, 2D6 et 2B6, la névirapine (NVP) et ceci pour différentes voies d'administration et pour des populations enceintes et non enceintes. De plus les clairances individuelles disponibles pour le TFV, le FTC et le 3TC tout au long de la grossesse ont permis d'explorer l'évolution de la sécrétion rénale. Celle-ci évoluerait proportionnellement au débit plasmatique rénal. L'intégration dans les modèles PBPK, des paramètres estimés à partir de l'expérience ex-vivo de cotylédon humain perfusé, a permis la prédiction de la cinétique foetale en fin de grossesse du TFV, FTC et NVP. Les prédictions ont été validées en les comparants aux concentrations mesurées au sang de cordon à l'accouchement. De plus, pour la névirapine nous avons exploré le métabolisme foetal et en avons conclu que même si celui-ci existe et est proche voir un peu supérieur à celui du nouveau-né, il n'influence pas la cinétique foetale. / Pregnant women are exposed to numerous drugs and for obvious ethical reasons studies in this sensitive population arelimited. Information about the maternal pharmacokinetic (PK) changes and transplacental transfer of drugs prior to theiradministration to pregnant women would be highly useful. Indeed is it known that physiological changes during pregnancycan affect drug disposition. Time-varying pregnancy-related physiological parameters changes were implemented in fullPBPK models. They successfully predicted the disposition of 3 renally excreted drugs tenofovir (TFV), emtricitabine (FTC)and lamivudine (3TC) and one metabolized drug, nevirapine (NVP) for non-pregnant and pregnant populations. We foundthat both renal secretion and filtration changed during pregnancy. Changes in renal clearance secretion were related tochanges in renal plasma flow. Transplacental parameters estimated from ex vivo human placenta perfusion experiments implemented in PBPK models allowed good prediction of foetal TFV, FTC and NVP PK. Predictions were compared to observed cord blood concentrations to validate these models. Moreover, we have explored nevirapine foetal metabolism and concluded that even if the foetal metabolism is the same than the newborn one or a little more important, it is notlikely to impact foetal PK.

Thesis (MSc (Biomedical Technology))--Cape Peninsula University of Technology, 2018. / The challenge of antimicrobial resistance has increased drastically over the years as more microorganisms are becoming resistant to the available conventional treatments. The burden of antimicrobial resistant infections is intensified by the increase in immunocompromising conditions such as HIV/AIDS and cancer. Due to this challenge, pharmaceutical companies, health sectors and researches are in search of new antimicrobial agents that can solve the problem at hand. Medicinal plants are a reliable source for drug discovery as it is estimated that 25% of modern medicine originated from plants. They have also been used traditionally as sources of medicine in the treatment of many human ailments. Plants can also be applied in the field of nanotechnology. Nanotechnology is a promising field in medicine as it has the potential to offer improved methods for disease diagnostics and therapeutics. The use of plants in nanotechnology brings about biologically friendly nanomaterials. Cotyledon orbiculata is one of the well-known and common plants of South Africa that is used in traditional medicinal practices. The nanotechnology applications as well as the antimicrobial and immunomodulatory effects of this plant were evaluated. The ability of C. orbiculata to synthesize silver nanoparticles was determined. Optimisation of silver nanoparticle synthesis using water extract of C. orbiculata was done at different conditions. The conditions evaluated include, reaction temperature (25 and 70°C), silver nitrate concentration (1 and 3mM), plant extract concentration (1.5, 3 and 6mg/ml) and reaction time. The synthesis of silver nanoparticles using this plant was successful. The optimal conditions for the synthesis of silver nanoparticles using C. orbiculata were 3mg/ml of the C. orbiculata extract, 3mM silver nitrate at a reaction temperature of 70°C for 2 hours. Under these conditions, spherical, crystalline nanoparticles with sizes of 20-40nm were produced. The antimicrobial and immunomodulatory properties of C. orbiculata extracts and silver nanoparticles were evaluated. Antimicrobial activity was evaluated against Staphylococcus aureus, Staphylococcus epidermidis, Methicillin resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and Candida albicans, using the micro-dilution assay to determine the minimum inhibitory concentration (MIC). The results obtained revealed that all extracts of C. orbiculata have antimicrobial properties against all the microorganisms tested. The MICs of the extracts ranged from 3.13 to 50mg/ml and the MBC/MFC from 6.25 to >100mg/ml. The methanol extract exhibited better antimicrobial activity in comparison to the others extracts whereas the water extract had better antifungal properties. The chloroform extract showed the lowest activity in both antibacterial and antifungal studies. Silver nanoparticles also exhibited antimicrobial activity against all the microorganisms tested. It’s MICs against these microorganisms ranged from 5–80μg/ml and MBC/MFC from 20-160μg/ml. The silver nanoparticles were highly active than the water extract against both the bacteria and the fungi. Immunomodulatory effects of the plant extracts and silver nanoparticles were determined by evaluating cytokine production using the enzyme linked immunoassay (ELISA) assay. All the extracts and silver nanoparticles of C. orbiculata were found to have anti-inflammatory properties. The water extracts showed more anti-inflammatory activity against the cytokines than the other extracts. However the silver nanoparticles were more active than the water extract. The findings from this study confirmed that C. orbiculata have antimicrobial and immunomodulatory effects. This provided scientific evidence of the traditional use of this plant in the treatment of skin infections and inflammatory conditions.

The use of traditional and natural medicines in primary healthcare or alternative therapy is on the increase. However, the safety and efficacy of these medicines have not yet been confirmed. Pharmacognosy, the study of the properties of drugs, potential drugs or drug substances of natural origin and the search for new drugs from natural resources, is therefore of extreme importance in today’s healthcare environment. Cotyledon orbiculata L. var. orbiculata (Haw.) DC., a succulent shrub that is widely distributed over the whole of southern Africa, is an example of a plant used in traditional medicine for its antiepileptic effects. Oxidative stress can either be the cause of, or be secondary to epilepsy pathogenesis. Lipid peroxidation causes the disruption of cell membranes which leads to cell destruction and, in the case of neurological disorders, neurodegeneration. Reactive species have also been found to influence neurotransmission by affecting neurotransmitter metabolism and functions. Reactive species can therefore be responsible for the development of convulsions. Conventional anti-epileptics have shown to exert neuroprotective effects but information or research regarding their ability to prevent epilepsy from becoming chronic does either not exist or is not promising. Antioxidants have potential in the treatment of epileptic seizures as well as the prevention of chronic epilepsy by preventing the effects that oxidative stress has on neurotransmitter metabolism and functions that cause alterations in neuronal excitability and seizure threshold, ultimately leading to epileptic foci. The aim of this study was to evaluate the potential of the bufadienolide orbicusides of C. orbiculata and analogues as anti-epileptic treatment through antioxidant activity. Initially the isolation of novel antioxidants from C. orbiculata leaf juice was attempted. The antioxidant activity of the concentrated juice and fractions resulting thereof were evaluated with two assays. The thiobarbituric acid (TBA) assay was used to measure the extent of lipid peroxidation and nitroblue tetrazolium (NBT) assay was used to measure superoxide scavenging activity in rat brain homogenate. The low concentrations of orbicusides prompted the determination of the activity of two commercial bufadienolides (bufalin and cinobufotalin) and two bufadienolide analogues, synthesised by the esterification of trans-androsterone and androstanolone, respectively, using coumalic acid, producing Compound 1 and Compound 2. The toxicity of the commercial bufadienolides and synthesised analogues were evaluated by using the MTT assay (a cell viability assay). C. orbiculata juice showed significant pro-oxidant activity in both assays. Bufalin showed significant pro-oxidant activity in the TBA assay. Cinobufotalin showed no significant activity. Compound 1 showed pro-oxidant activity in the TBA assay and Compound 2 showed slight antioxidant activity in the NBT assay. The commercial bufadienolides showed low cell viability, indicating significant toxicity. The synthesised analogues showed a significant reduction in toxicity (despite Compound 2 being moderately toxic) when compared to the toxicity of the commercial bufadienolides. The low concentrations of orbicusides in the plant material and the antioxidant assay results of the two commercial bufadienolides suggested that the orbicusides may not be involved in the antioxidant properties of C. orbiculata. However, the antioxidant activity of Compound 2 showed that altering the pyrone moiety of bufadienolides could possibly improve antioxidant activity. The reduced toxicity and slight antioxidant activity of the synthesised bufadienolide analogues motivates further investigation. / MSc (Pharmaceutical Chemistry), North-West University, Potchefstroom Campus, 2014