Dissertationen zum Thema „S 3-8“

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Furocoumarins (FCs) are an important class of photoactive compounds which may potentially bind to DNA forming intermolecular complexes, and once excited by UVA light (~ 365 nm) they re able to form photoadducts, which may result in mutagenicity and lethality. However, when the 8-methoxypsoralen (8-MOP) is added to the post-irradiation plating medium increases the sensitization probably by inhibiting repairs in damaged DNA. The FCs also have a protective effect against UVC (~254 nm) attributed to the inhibition of pyrimidine dimers. FCs associated with UVB light (312 nm), remain few known. The aim of the present study was to investigate the lethal effect of UVB light alone, and combined with solutions of 8-MOP, 4,5',8-trimethylpsoralen (TMP) and 3-carbetoxypsoralen (3-CPs) at different concentrations on Staphylococcus aureus growth. We also evaluated the effect of these FCs in the plating medium. Treatment with 8-MOP-UVB and TMP-UVB were more effective in inducing lethality than the UVB treatment alone. Increasing the solution concentration of 8-MOP resulted in a higher mortality while the increase in the concentration of the TMP led to a reduction in the lethality. For other hand, 3-CPs displayed a photoprotective effect against UVB damage in all concentrations tested. The results of FCs in the plating medium showed that the 8-MOP induzed a higher lethal effect and also increased mortality from bacterial strain treated by FC-UVB. The different behaviors shown by FCs may be related with differences in the sequence specificity of binding and photoreaction, inhibition of pyrimidine dimers formation by intercalated molecules and efficacy of repair systems. These results emphasize the need for further studies to elucidate the participation of FCs as photosensitizing and photoprotective agents in biological systems, when combined with UVB.
As furocumarinas (FCs) são uma importante classe de compostos fotoativos que potencialmente podem se ligar ao DNA formando complexos intermoleculares, e uma vez excitados por luz UVA (~365 nm) são capazes de formar fotoadições, que podem resultar em mutagênese e letalidade. Porém, quando a 8-metoxipsoraleína (8-MOP) está adicionada ao meio de plaqueamento pós-irradiação aumenta a sensibilidade provavelmente por inibir reparo de lesões no DNA. As FCs também possuem efeito protetor contra UVC (~254 nm) atribuído à inibição da formação de dímeros de pirimidina. As FCs associadas à UVB (312 nm) permanecem pouco conhecidas. O objetivo do presente estudo foi investigar o efeito da luz UVB, e combinada com soluções de 8-MOP, 4,5 ,8-trimetilpsoraleína (TMP) e 3-carbetoxipsoraleína (3-CPs) em diferentes concentrações, sobre o crescimento de Staphylococcus aureus. Avaliamos também o efeito destas FCs em meio de plaqueamento. O tratamento com 8-MOP-UVB e TMP-UVB foram mais eficazes em induzir letalidade do que o tratamento apenas com UVB. O aumento da concentração de 8-MOP resultou em mortalidade mais elevada enquanto que o aumento na concentração de TMP levou a redução na mortalidade. Por outro lado, 3-CPs exibiu efeito fotoprotetor contra danos causados por UVB em todas as concentrações testadas. Os resultados com FCs no meio de plaqueamento mostraram que a 8-MOP induziu o maior efeito letal e também aumentou a mortalidade da cepa bacteriana tratada por FC-UVB. Os diferentes efeitos apresentados pelas FCs podem estar relacionados com diferenças na especificidade por seqüência de ligação e fotorreação, a inibição da formação de dímeros de pirimidina por moléculas intercaladas e eficácia de sistemas de reparo. Esses resultados reforçam a necessidade de mais estudos para elucidar a participação das FCs como agentes fotossensibilizantes e fotoprotetores em sistemas biológicos, quando combinadas com UVB.

Purpose: Monoamine oxidase (MAO) plays a key role in the treatment of Parkinson‟s disease (PD), since it is the major enzyme responsible for the catabolism of dopamine in the substantia nigra of the brain. Inhibition of MAO-B may conserve dopamine in the brain and provide symptomatic relief. The MAO-B inhibitors that are currently used for the treatment of PD, are associated with a variety of adverse effects (psychotoxic and cardiovascular effects) along with additional disadvantages such as irreversible inhibition of the enzyme. Irreversible inhibition may be considered a disadvantage, since following treatment with irreversible inhibitors, the rate by which the enzyme activity is recovered may be variable and may require several weeks. In contrast, following the administration of reversible inhibitors, enzyme activity is recovered when the inhibitor is cleared from the tissues. There exists therefore, a need to develop new reversible inhibitors of MAO-B which are considered to be safer than irreversible MAO-B inhibitors. Rationale: Recently discovered reversible MAO-B inhibitors include safinamide and (E)-8-(3-chlorostyryl)caffeine (CSC). Safinamide has a benzyloxy side chain, which is thought to be important for inhibition of MAO-B. CSC, on the other hand, consists of a caffeine moiety with a styryl substituent at C-8, which is also a critical feature for its inhibitory activity. In a previous study, the caffeine ring and the benzyloxy side chain were combined to produce a series of 8-benzyloxycaffeine analogues which proved to be potent new MAO-B inhibitors. In this study, caffeine was substituted with the phenoxymethyl functional group at C-8, instead of the benzyloxy moiety. The aim of this study was therefore to compare the MAO-B inhibition potencies of selected 8-(phenoxymethyl)caffeine analogues with the previously studied 8-benzyloxycaffeine analogues. In the current study, 8-(phenoxymethyl)caffeine (1) and nine 8-(phenoxymethyl)caffeine analogues (2-10) were synthesized and evaluated as inhibitors of recombinant human MAOA and –B. These analogues only differed in substitution on C3 and C4 of the phenoxymethyl phenyl ring. The substituents that were selected were halogens (Cl, F, and Br), the methyl group, the methoxy group and the trifluoromethyl group. These substituents are similar to those selected in a previous study where 8-benzyloxycaffeine analogues were evaluated as MAO inhibitors. This study therefore explores the effect that a variety of substituents on C3 and C4 of the phenoxymethyl phenyl ring will have on the MAO-A and –B inhibition potencies of 8-(phenoxymethyl)caffeine. Based on the results, additional 8-(phenoxymethyl)caffeine analogues with improved MAO-A and –B inhibition potencies will be proposed for investigation in future studies. Methods: The target, 8-(phenoxymethyl)caffeine, analogues were synthesized by reacting 1,3- dimethyl-5,6-diaminouracil with the appropriately substituted phenoxyacetic acid in the presence of a carbodiimide coupling agent. Ring closure was catalyzed in basic conditions and methylation of the resulting theophyline intermediates at C-7 was carried out with iodomethane. The structures and purities of all the target compounds were verified by NMR, MS and HPLC analysis. All of the 8-(phenoxymethyl)caffeine analogues were subsequently evaluated as MAO-A and –B inhibitors using the recombinant human enzymes. The inhibition potencies of the analogues were expressed as the IC50 values (concentration of the inhibitor that produces 50% inhibition). In addition, the time-dependency of inhibition of both MAO-A and –B was evaluated for two inhibitors in order to determine if these inhibitors interact reversibly or irreversibly with the MAO isozymes. A Hansch-type quantitative structure-activity relationship (QSAR) study was carried out in order to quantify the effect that different substituents on the phenyl ring of the 8-(phenoxymethyl)caffeine analogues have on MAO-B inhibition activity. Results: The results showed that among the test compounds, several analogues potently inhibited human MAO-B. The most potent inhibitor was 8-(3-bromophenoxymethyl)caffeine with an IC50 value of 0.148 μM toward human MAO-B. There were also inhibitors which displayed inhibition activities towards human MAO-A with IC50 values ranging from 4.59 μM to 34.0 μM. Compared to the 8-benzyloxycaffeine analogues, that were in general non-selective inhibitors, the 8-(phenoxymethyl)caffeine analogues, evaluated here, were selective for MAO-B. For example, 8-(3-bromophenoxymethyl)caffeine was found to be 141 fold more selective as an inhibitor of MAO-B than of MAO-A. Also, compared to the 8-benzyloxycaffeine analogues, the 8-(phenoxymethyl)caffeine analogues were slightly less potent MAO-B inhibitors. For example, 8-benzyloxycaffeine is reported to have an IC50 value of 1.77 μM for the inhibition of human MAO-B while 8-(phenoxymethyl)caffeine was found to have an IC50 value of 5.78 μM for the inhibition of human MAO-B. This study also shows that two selected analogues bind reversibly to MAO-A and –B, respectively, and that the mode of MAO-B inhibition is competitive for one representative compound. Qualitative inspection of the results revealed interesting structure-activity relationships. For the 8-(phenoxymethyl)caffeine analogues, bearing both the C3 and C4 substituents on the phenyl ring, the MAO-B activity significantly increases with halogen substitution. Furthermore, increased MAO-B inhibition was observed with increased electronegativity of the halogen substituent. To quantify these apparent relationships, a Hansch-type QSAR study was carried out. The results showed that the logarithm of the IC50 values (logIC50) correlated with Hansch lipophilicity (π) and the Swain-Lupton electronic (F) constants of the substituents at C-3 of the phenoxymethyl ring. The correlation exhibited an R2 value of 0.87 and a statistical F value of 13.6. From these results it may be concluded that electron-withdrawing substituents at C3 with a high degree of lipophilicity enhance MAO-B inhibition potency. These results are similar to those previously obtained for the series of 8-benzyloxycaffeine analogues. For this series, the MAO-B inhibition potencies correlated with the Hansch lipophilicity (π) and Hammett electronic (σ) constants of the substituents at C-3 of the benzyloxy ring. Similarly to the 8-(phenoxymethyl)caffeine analogues, electron-withdrawing substituents with a high degree of lipophilicity also enhance the MAO-B inhibition potencies of 8-benzyloxycaffeine analogues.
Thesis (M.Sc. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2011

Rezension: Michael F. Runowski, Polnische Orgelmusik nach 1945 Zwar kann die moderne polnische Musik aufgrund des seit 1956 existierenden und seinerzeit so spektakulären Festivals Warszawska Jesien [Warschauer Herbst] auch im Ausland als immerhin in groben Grundzügen bekannt gelten. Da aber – wie Runowski selbst hervorhebt– geistliche Musik auf diesem Festival nie eine größere Rolle spielte, blieb dieser Bereich polnischen Musikschaffens nicht nur im Ausland, sondern auch in Polen selbst einem breiteren Publikum verborgen. Umso interessanter ist die Existenz einer durchgehenden polnischen Orgelmusiktraditionseit Kriegsende bis heute, und doppelt interessant ist diese Existenz angesichts der Spannung zwischen katholischem Glauben und kommunistischem System in der Volksrepublik Polen.

Zika (ZIKV), La Crosse (LACV), and Cache Valley (CVV) viruses are mosquito-vectored diseases that cause significant morbidity and mortality in humans and animals. Transmission of these viruses are dependent on numerous factors including vector competence and the effects of mosquito-virus interactions. We conducted vector competence studies of local Aedes and Culex mosquitoes for ZIKV and CVV, and found that all Aedes mosquitoes were competent for CVV and only Aedes albopictus and Aedes japonicus were competent for ZIKV. Vector competence for CVV was dose-dependent, where mosquitoes orally infected with high titers developed higher transmission rates. We also found that vector competence for ZIKV was limited by midgut and salivary gland barriers. Second, we looked at the effects of LACV and ZIKV infection on repellent response in Aedes mosquitoes and found that infected mosquitoes were refractory to low concentrations of DEET, picaridin, and PMD. Increasing concentrations of the repellents to ≥10% was able to increase percent protection (%p) against infected and uninfected mosquitoes. Lastly, we determined the effects of ZIKV and LACV infection on oxidative stress and glutathione-S-transferase (GST) activity in Aedes albopictus. Virus infection had no effect on oxidative stress, but GST activity was significantly different for mosquitoes 3-days post-exposure. We found that oxidative stress levels and GST activity had an inverse relationship for infected and uninfected mosquitoes, where oxidative stress decreased and GST activity increased over the 10-day test period. This indicates that GSTs may aid in controlling byproducts of oxidative stress. The results from this entire study identified competent vectors for emerging arboviruses and demonstrated the behavioral and physiological effects of virus infection in the mosquito vector.
Doctor of Philosophy
Zika (ZIKV), La Crosse (LACV), and Cache Valley (CVV) viruses are transmitted by mosquitoes and can make humans and animals very sick. There are many biological factors that determine if a mosquito can transmit a virus and these viruses can change the biology of a mosquito. We conducted laboratory studies to see if Aedes and Culex mosquitoes can transmit ZIKV and CVV. We found that all Aedes mosquitoes were able to transmit CVV and only the Asian tiger mosquito and Asian rock pool mosquito were able to transmit ZIKV. Mosquitoes infected with high amounts of CVV developed higher transmission rates. We also found that transmission of ZIKV was limited by barriers in the mosquito midgut and salivary glands. Second, we looked at the effects of LACV and ZIKV infection on how Aedes mosquitoes respond to repellents and found that infected mosquitoes were less sensitive to low concentrations of DEET, picaridin, and PMD. Increasing concentrations of the repellents to 10% or higher was able to provide adequate protection against infected and uninfected mosquitoes. Lastly, we determined the effects of ZIKV and LACV infection on oxidative stress and glutathione-S-transferase (GST) activity in the Asian tiger mosquito. Virus infection did not change oxidative stress, but GST activity was higher in infected mosquitoes tested after 3 days after infection. We found that oxidative stress decreased and GST activity increased over the 10-day test period. This indicates that GSTs may help control damaging products from oxidative stress. The results from this entire study identified what mosquitoes were able to transmit emerging mosquito-borne viruses and demonstrated the biological effects of virus infection in the mosquitoes.

De nouveaux outils pour la synthèse asymétrique sont proposés : des auxiliaires chiraux à centre d'aiguillage (R,S). Le passage du (1R,2S,5R)-2-diméthylphénylméthyl-5-méthylcyclohexyl carbaldéhyde à l'imine correspondante du glycinate de méthyle, suivi de la déprotonation (diisopropylamidure de lithium), puis de l'alkylation par des halogénures d'alkyles conduit après hydrolyse à des α-aminoacides de configuration (R) avec des e. E. >98%. Il a été montré que pour obtenir les α-aminoacides de configuration (S), il n'était pas nécessaire d'inverser la totalité des centres stéréogéniques de l'aldéhyde initial, l'inversion d'un seul centre étant suffisante. Ainsi, à partir de l'aldéhyde (1S,2S,5R), des α-aminoacides de configuration (S) ont été obtenus avec des e. E. >98%. La méthode a été généralisée à la synthèse d'un α-aminoacide à centre quaternaire la (R)-methyldopa avec un e. E. >98%. Les aldéhydes (1R,2S,5R) et (1S,2S,5R) sont aisément obtenus à partir de la (R)-(+)-pulégone et transformés facilement l'un en l'autre par épimérisation. L'aldéhyde utilisé est donc un auxiliaire chiral à centre d'aiguillage (R,S).

This study seeks to assess the level of women&rsquo
s participation and involvement in the promotion of effective governance during the African Peer Review Mechanism (APRM) implementation exercise in 2007, which was endorsed by the APRM Western Cape Province. The interest of the study arises from the concept of &lsquo
good governance&rsquo
and how the implementation of such a concept is carried out in the rendering of public services, specifically the role of women in rendering public service in the Western Cape Province, South Africa.

GONÇALVES, Fabricio Mota. Evapotranspiração e coeficientes de cultivo (KC) da cana-de-açúcar irrigada por gotejamento subsuperficial. 2010. 64 f. Dissertação (Mestrado em engenharia agrícola)- Universidade Federal do Ceará, Fortaleza-CE, 2010.
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Sugar cane is one of the crops with the highest level of water consumption, with a high evapotranspiration demand throughout most of its cycle. Knowledge of the sugar cane water demand, the time that irrigation should be applied, and how to irrigate the crop are becoming increasingly important for the sustainable development of irrigated sugar cane cultivation, especially in areas of low water availability, as it is the case in northea stern Brazil. The experiment was carried out at the Curu Experimental Field (property of the Embrapa Tropical Agroindustry), located in the Curu-Paraipaba Irrig ation Project, city of Paraipaba-CE (3 ° 29 '20''S, 39 ° 9' 45''W and elevation 30m), in order to determine the evapotrans piration and crop coefficients (Kc) of sugarcane (Saccharum L. officinarium), subsurface drip-irrigated. It was used the SP 6949 sugar cane variety, planted in a spacing of 1.8 m between double rows and 0.4 m between rows within the double row. As to t he irrigation, we used one lateral water line for each double row, buried at a depth of 0.15 m, w ith self-compensating drip emitters, with a flow rate of 1 L h-1, spaced 0.5 m on the water line. The crop was irrigated daily and there were three fertigations per week. The irrigation de pth was periodically adjusted, keeping the soil water potential between -8 kPa to -20 kPa. The crop evapotranspiration (ETc) was determined using a wei ghing lysimeter with a surface area of 2.25 m 2. The reference evapotranspiration (ETo) was estimated by the FAO Penman-Monteith method. The durations of the phenological stages of cane sugar were estimated through analysis of soil cover, with the use of digital images. Durations of 31, 49, 237 and 118 days were observed, respectively for initial, crop development, mid-season and late season stages. The yields achieved within and outside the lysimeter were respectively 144.4 and 108.8 t ha -1 . The total ETc observed during the cycle of the sugar cane was 1074.1 m m, with maximum values of 6.6 mm d-1 during the mid-season stage. Observed Kc values for initial, mid-season and late season stages were respectively 0.23, 1 .03 and 0.50. In the crop development stage, the relationship between Kc and the (crop) soil cover was represented with good accuracy by a negative quadratic model.
A cana-de-açúcar é uma das culturas com maior consumo de água, apresentando uma alta demanda evapotranspirativa ao longo da maior parte do seu ciclo. O conhecimento das necessidades hídricas da cana-de-açúcar, do momento de aplicação da água requerida pela mesma e a forma de aplicação torna-se cada vez mais importante para o desenvolvimento sustentável da sua produção irrigada, principalmente em regiões de pouca disponibilidade hídrica, como é o caso da região Nordeste do Brasil. O experimento foi conduzido no Campo Experimental do Curu, pertencente à Embrapa Agroindústria Tropical localizado no Perímetro Irrigado Curu-Paraipaba, município de Paraipaba-CE (3° 29’ 20’’ S, 39° 9’ 45’’ W e altitude de 30 m), com o objetivo de determinar a evapotranspiração e os coeficientes de cultivo (Kc) da cana-de-açúcar (Saccharum officinarium L.), irrigada por gotejamento subsuperficial. Utilizou-se a variedade de cana SP 6949, plantada no espaçamento de 1,8 m entre fileiras duplas e 0,4 m entre linhas dentro da fileira dupla. Na irrigação utilizou-se uma linha lateral para cada fileira dupla, enterrada na profundidade de 0,15 m, com gotejadores autocompensantes, com vazão de 1 L h-1, espaçados de 0,5 m na linha. A cultura foi irrigada com freqüência diária e foram realizadas três fertirrigações por semana. A lâmina de irrigação foi ajustada periodicamente, mantendo-se o potencial de água no solo entre -8 kPa e -20 kPa. A evapotranspiração da cultura (ETc) foi determinada utilizando-se um lisímetro de pesagem com área superficial de 2,25 m2. A evapotranspiração de referência (ETo) foi estimada pelo método FAO Penman-Monteith. As durações das fases fenológicas da cana-de-açúcar foram estimadas por meio da análise da cobertura do solo pela cultura, determinada com o uso de imagens digitais. Foram observadas durações de 31, 49, 237 e 118 dias, para as fases inicial, de desenvolvimento, intermediária e final, respectivamente. A produtividade alcançada dentro e fora do lisímetro foi de 144,4 e 108,8 t ha-1, respectivamente. A ETc total observada durante o ciclo da cana-de-açúcar foi de 1.074,1 mm, com valores máximos da ordem de 6,6 mm d-1 durante a fase intermediária. Foram observados valores de Kc iguais a 0,23, 1,03 e 0,50, para as fases inicial, intermediária e final, respectivamente. Na fase de desenvolvimento vegetativo a relação entre o Kc e a cobertura do solo pela cultura foi representada com bastante exatidão por um modelo quadrático negativo.

碩士
國立高雄師範大學
物理學系
89
Abstract The main purpose of this study is to investigate children''s concept and sub-concept developing of Newton’s Third law. A semi-structured interview was used to find out the factors that affected the thinking about it from 54 children. The results were found: 1. In those sub-concepts of Newton’s Third Law 「action force」、「reaction force」、「direction of action and reaction force」、「magnitude of action and reaction force」and「synchronism of action and reaction force」, children’s thinking were sequential order different between dynamic and static situation. 2.The conceptual development of children on Newton’s Third Law positively related to their grades and their CMS level. 3. The conceptual development of children on Newton’s Third Law, which present in dynamic motion, is more acceptable than static motion. Key words：Newton’s Third Law、concept、action force、reaction force、conceptual development.

This study was based on the Science and Indigenous Knowledge Systems Project (SIKSP) at the School of Science and Mathematics Education, University of the Western Cape. The project seeks to enhance educators’ understanding of and ability to implement a Science-IKS curriculum (Ogunniyi, 2007) through using the theoretical framework of argumentation (Toulmin Argument Pattern) to the extent that learners would value the significance of both worldviews. This study sought to find the effects of an Argumentation-Based Instruction on grade 10 learners’ understanding of the causes of pollution at a river site. Since the integration of Science and IKS are envisaged by Curriculum 2005 (C2005), two theoretical argumentation constructs have been used namely, Toulmin’s (1958) Argumentation Pattern (TAP) and Ogunniyi’s (1995) Contiguity Argumentation Theory (CAT).