Made available in DSpace on 2014-06-12T23:14:00Z (GMT). No. of bitstreams: 2 arquivo4310_1.pdf: 9058889 bytes, checksum: 523800767050929b4eae4629c71c3980 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Neo-glicoconjugados constituem uma classe de compostos em que os carboidratos estão conjugados a outras moléculas de interesse biológico. Os 1,2,4-oxadiazóis são heterociclos bastante conhecidos em química medicinal, apresentando várias atividades farmacológicas e tendo sido considerados bioisósteros de ésteres e amidas. Este trabalho descreve a síntese de oxadiazóis enantiomericamente enriquecidos através de biocatálise com Daucus carota, a fim de preparar compostos glico-heterocíclicos; a síntese de novos neo-glicoconjugados contendo heterociclos e aminoácidos através de catálise mediada por Pd(0) e click chemistry e a avaliação da atividade biológica de alguns dos produtos sintetizados. A biorredução de oxadiazóis-cetona com D. carota forneceu oxadiazóis enriquecidos enantiomericamente com excessos enantioméricos variando de 52 a 72%. Os álcoois obtidos têm configuração absoluta S, o que está de acordo com a regra de Prelog para as biorreduções utilizando este sistema enzimático. A seguir, oxadiazóis com uma função fenol foram anexados na posição C-4 de um carboidrato insaturado através de alquilação alílica mediada por Pd(0), de maneira regiosseletiva. Estes glicosídeos insaturados foram transformados em manopiranosídeos através de bis-hidroxilação seguida de bis-acetilação. Em outro momento, vários oxadiazóis, derivados da uracila e aminoácidos foram anexados a carboidratos diversos através da cicloadição 1,3-dipolar catalisada por Cu(I), fornecendo diversos glicoconjugados com um espaçador 1,2,3-triazol. Os produtos foram obtidos de maneira regiosseletiva e os glicoconjugados com a porção carboidrato insaturada foram bis-hidroxilados e bis-acetilados, formando os respectivos manopiranosídeos. Alguns dos glicoconjugados tiveram suas propriedades biológicas avaliadas. Nenhum dos compostos avaliados demonstrou atividade antimicrobiana contra os microorganismos testados. Alguns produtos demonstraram ter atividade citotóxica em linhagens de células cancerígenas HEp-2 e NCI-H292, com valores de CI50 menores que 10 ug/mL. Estudos de microscopia eletrônica de varredura (MEV) foram realizados nas células cancerígenas da linhagem HEp-2 e forneceram fortes indícios de que estas substâncias ativariam a apoptose nas células estudadas

The strain promoted azide alkyne cycloaddition (SPAAC) of azido nucleobase modified nucleosides and nucleotides with cyclooctynes to give fluorescent triazoles has been relatively unexplored. Thus, SPAAC between azido-nucleobases and various cyclooctynes in aqueous solution at ambient temperature resulted in the efficient formation (3 min - 2 h) of triazole products with inherent fluorescent properties. The 2- and 8-azidoadenine nucleosides reacted with fused cyclopropyl cyclooctyne, dibenzylcyclooctyne or monofluorocyclooctyne to produce click products functionalized with hydroxyl, amino, N-hydroxysuccinimide, or biotin moieties. The previously unexplored 5-azidouridine and labile 5-azido-2'-deoxyuridine were similarly converted to the analogous triazole products in quantitative yields in less than 5 minutes. The 8-azido-ATP quantitatively afforded the triazole product with fused cyclopropyl cyclooctyne (3 h). Addition of a triazole ring at the 2 or 8 position of adenine or 5-position of uracil induces fluorescent properties which were used for direct imaging with fluorescent microscopy in MCF-7 cancer cells without the need for traditional fluorogenic reporters. Fluorescent lifetime imaging microscopy of the click adducts in live cells were used to determine the lifetime of each fluorophore in the cellular nuclei demonstrating the potential utility of the synthesized triazole adducts for dynamic measuring and tracking of events inside single living cancer cells. The SPAAC methodology developed has also been applied to study the cellular targets in protozoal parasite, Trichomonas vaginalis and bacteria, Pseudomonas aeruginosa. The 9-(2-deoxy-2-fluoro-β,D-arabino-furanosyl)adenine (arabino-F-Ado) was modified with an azido moiety at the C8 position for use in click chemistry. Tagging and subcellular localization studies using azido modified arabino-F-Ado could provide insight into the mechanism of action of arabino-F-Ado. An activated analogue of S-adenosyl-L-methionine (SAM) with an EnYn group on the sulfur instead of a methyl group was prepared to study the transfer of the methyl group from SAM. I found that the EnYn group was transferred from SAM to a guanosine on tRNA by methytransferase Trm1. Thus, AdoEnYn is a competitive inhibitor of SAM and can be incorporated into tRNA in place of SAM.

Previous work in our group has been directed towards the synthesis of crown-ethers for use in the selective complexation of metal ions and as chiral ligands for use in asymmetric catalysis. The development of a modular approach to macrocycle assembly has enabled the synthesis of a library of pyridine-based macrocycles possessing multiple donor sites where chirality was readily introduced from simple amino acids.The nucleophilic ring opening of aziridines 181, 193 or 194, allowed the highly selective synthesis of thioether-based spacers and macrocycles. Extension of this basic approach to the synthesis of seleno-crown ethers was also investigated. The use of chiral-pool starting materials derived from D- or L-alanine, provided access to optically pure macrocycles. The use of the Sharpless-Huisgen 'click' reactions allowed the attachment of a carbohydrate residue directly to a macrocycle via a triazole unit. We hope to attach a macrocycle, carbohydrate residue and azo dye together, to be able to examine further diseases such as Alzheimer's. We have so far succeeded in attaching a macrocycle and sugar to a central scaffold by performing a one-pot double 'click' reaction. The distance between the points of attachment of the chromophore to the macrocycle metal binding site is probably, in this first generation sensor, too great to enable a metal-macrocycle binding event to be reported.

Over the past decades, numerous studies shown curcumin, a dietary compound derived from turmeric, has a variety of health-promoting actions, such as anti-oxidant, anti-microbial, anti-inflammatory, and anti-cancer effects, making curcumin the most promising dietary compound for disease prevention. However, the underlying mechanisms by which curcumin has these health-promoting effects are not well understood. A better understanding of the molecular mechanism of curcumin could help to develop novel strategies to reduce the risks of some human diseases. Protein thiols play important roles in cell signaling, and recent studies showed that curcumin could covalently react with protein thiols, supporting that curcumin-protein interactions could contribute to the health-promoting effects of curcumin. However, the curcumin-protein interactions are under-studied. Notably, it remains unknown whether oral intake of curcumin could covalently interact with protein in vivo. In this project, we synthesized a click chemistry probe of curcumin (Di-Cur), and used this probe to characterize curcumin-protein interactions both in vitro and in vivo using a click chemistry-based imaging approach. Our results demonstrate that orally administrated curcumin could form curcumin-protein adducts in specific tissues of the mice, which may contribute to the potent biological effects and poor pharmacokinetics of curcumin.

The construction and real estate sector contributed with about 18 tons of carbon dioxideequivalents which corresponds to almost 21 percent of Sweden’s total greenhouse gasemissions. Fact is that the construction and real estate sector contribute a significant part inthe climate impact.An approach to examine a building’s environmental impact is to implement Life CycleAssessment (LCA). By doing that a full picture of the climate impact during the building’slifetime can be seen. The results can be used to find out in what stage of the building processimprovements can be done to reduce the climate impact.The purpose of this study is to examine and understand how to execute Climate CycleAssessments and Life Cycle Assessments and how they can support the decisions forbuilding constructions with less climate impact. The aim is to examine digital conditions thatare required to be able to integrate the BIM-software Revit with One Click LCA. The study islimited to analyzing the frame and the foundation of a building. Only LCA-modules A1-3will be calculated because these modules are included in the mandatory climate declarationfrom year 2022. A1-3 includes raw material extraction, transport and manufacturing.The study is based on a qualitative method, where information is obtained from literaturestudies and semi-structured interviews to answer the questions of this study. The literaturestudy is done by using scientific articles, reports, and literature. Semi-structured interviewsare accomplished with relevant respondents. The software that is used to execute the analysisis One Click LCA, which is integrable with Revit due to an add-in in the program.The integration between BIM and LCA was tested by using One Click LCA:s add-in tool inRevit, a result was then available but a completion had to be done in One Click LCA:s webapplication to get a result that includes the carbon dioxide equivalents from the modulesA1-3. An update of One Click LCA:s add-in program should be developed to avoid extrawork and save more time. It is worth mentioning that the current add-in tool already haspossibilities to save money and time, it also increases the possibilities to reduce the climateimpact in an early stage.Keywords: Life cycle assessment, climate impact, BIM, Revit, One Click LCA

No description available.

The purpose of this study was to develop and evaluate a measurement model for Internet information retrieval strategy performance evaluation whose theoretical basis is a modification of the classical measurement model embodied in the Cranfield studies and their progeny. Though not the first, the Cranfield studies were the most influential of the early evaluation experiments. The general problem with this model was and continues to be the subjectivity of the concept of relevance. In cyberspace, information scientists are using quantitative measurement models for evaluating information retrieval performance that are based on the Cranfield model. This research modified this model by incorporating enduser relevance judgment rather than using objective relevance judgments, and by adopting a fundamental unit of measure developed for the cyberspace of Internet information retrieval rather than using recall and precision-type measures. The proposed measure, the Content-bearing Click (CBC) Ratio, was developed as a quantitative measure reflecting the performance of an Internet IR strategy. Since the hypertext "click" is common to many Internet IR strategies, it was chosen as the fundamental unit of measure rather than the "document." The CBC Ratio is a ratio of hypertext click counts that can be viewed as a false drop measure that determines the average number of irrelevant content-bearing clicks that an enduser check before retrieving relevant information. After measurement data were collected, they were used to evaluate the reliability of several methods for aggregating relevance judgments. After reliability coefficients were calculated, measurement model was used to compare web catalog and web database performance in an experimental setting. Conclusions were the reached concerning the reliability of the proposed measurement model and its ability to measure Internet IR performance, as well as implications for clinical use of the Internet and for future research in Information Science.

This research aims to add to the current knowledge available for miniemulsion polymerization reactions and to use this knowledge to synthesize multifunctional nanosized latex particles that have the potential to be used in catalysis. The physical properties of the latex can be adjusted to suit various environments due to the multiple functional groups present. For this research, styrene, pentafluorostyrene, azidomethyl styrene, pentafluorostyrene with azidomethyl styrene and pentafluorostyrene with styrene latexes were produced, and analyzed by dynamic light scattering. The latexes were synthesized using a miniemulsion polymerization technique found through this research. Potassium oleate and potassium 1,1,2,2,3,3,4,4-nonafluorobutane-1-sulfonate were used as surfactants during the miniemulsion polymerization reaction to synthesize pentafluorostyrene with azidomethyl styrene latex. Transmission electron microscopy data and dynamic light scattering data have been collected to analyze the structure of this latex, and it has been synthesized using a number of conditions, differing in reaction time, surfactant amount and sonication methods. We have also improved the solubility of the latex through a copper(I) catalyzed 1,3-dipolar azide-alkyne reaction, by clicking (polyethylene glycol)5000 onto the azide functional groups.

The development of cellular life on earth is coupled to the formation of lipid-based biological membranes. Although many tools to analyze their biophysical properties already exist, their variety and number is still relatively small compared to the field of protein studies. One reason for this, is their small size and complex assembly into an asymmetric tightly packed lipid bilayer showing characteristics of a two-dimensional heterogenous fluid. Since membranes are capable to form dynamic, nanoscopic domains, enriched in sphingolipids and cholesterol, their detailed investigation is limited to techniques which access information below the diffraction limit of light. In this work, I aimed to extend, optimize and compare three different labeling approaches for sphingolipids and their subsequent analysis by the single-molecule localization microscopy (SMLM) technique direct stochastic optical reconstruction microscopy (dSTORM). First, I applied classical immunofluorescence by immunoglobulin G (IgG) antibody labeling to detect and quantify sphingolipid nanodomains in the plasma membrane of eukaryotic cells. I was able to identify and characterize ceramide-rich platforms (CRPs) with a size of ~ 75nm on the basal and apical membrane of different cell lines. Next, I used click-chemistry to characterize sphingolipid analogs in living and fixed cells. By using a combination of fluorescence microscopy and anisotropy experiments, I analyzed their accessibility and configuration in the plasma membrane, respectively. Azide-modified, short fatty acid side chains, were accessible to membrane impermeable dyes and localized outside the hydrophobic membrane core. In contrast, azide moieties at the end of longer fatty acid side chains were less accessible and conjugated dyes localized deeper within the plasma membrane. By introducing photo-crosslinkable diazirine groups or chemically addressable amine groups, I developed methods to improve their immobilization required for dSTORM. Finally, I harnessed the specific binding characteristics of non-toxic shiga toxin B subunits (STxBs) and cholera toxin B subunits (CTxBs) to label and quantify glycosphingolipid nanodomains in the context of Neisseria meningitidis infection. Under pyhsiological conditions, these glycosphingolipids were distributed homogenously in the plasma membrane but upon bacterial infection CTxB detectable gangliosides accumulated around invasive Neisseria meningitidis. I was able to highlight the importance of cell cycle dependent glycosphingolipid expression for the invasion process. Blocking membrane accessible sugar headgroups by pretreatment with CTxB significantly reduced the number of invasive bacteria which confirmed the importance of gangliosides for bacterial uptake into cells. Based on my results, it can be concluded that labeling of sphingolipids should be carefully optimized depending on the research question and applied microscopy technique. In particular, I was able to develop new tools and protocols which enable the characterization of sphingolipid nanodomains by dSTORM for all three labeling approaches. / Die Entwicklung von zellulären Lebensformen auf der Erde basiert auf der Entstehung biologischer Lipid-Membranen. Obwohl viele Techniken zur Verfügung stehen, welche es erlauben deren biophysikalische Eigenschaften zu untersuchen, sind die Möglichkeiten, verglichen mit der Analyse von Proteinen, eher eingeschränkt. Ein Grund hierfür, ist die geringe Größe von Lipiden und deren komplexe Zusammenlagerung in eine asymmetrische dicht gepackte Lipiddoppelschicht, welche sich wie eine heterogene zweidimensionale Flüssigkeit verhält. Durch die lokale Anreicherung von Sphingolipiden und Cholesterol sind Membranen in der Lage dynamische, nanoskopische Domänen auszubilden, welche lediglich mit Techniken, welche die optische Auflösungsgrenze umgehen, detailliert untersucht werden können. Ein wesentliches Ziel meiner Arbeit war es, drei Färbeverfahren für Sphingolipide zu vergleichen, erweitern und optimieren, um eine anschliessende Untersuchung mit Hilfe der einzelmolekülsensitiven Technik dSTORM (direct stochastic optical reconstruction microscopy) zu ermöglichen. Zunächst verwendete ich das klassische Färbeverfahren der Immunfluoreszenz, um Sphingolipid-Nanodomänen auf eukaryotischen Zellen mit Hilfe von Farbstoff-gekoppelten Antikörpern zu detektieren und quantifizieren. Dieses Vorgehen ermöglichte es mir, Ceramid-angereicherte Plattformen mit einer Größe von ~ 75nm auf der basalen und apikalen Membran verschiedener Zell-Linien zu identifizieren und charakterisieren. Als nächstes Verfahren verwendete ich die Klick-Chemie, um Sphingolipid-Analoge in lebenden und fixierten Zellen zu untersuchen. Eine Kombination aus Fluoreszenz-Mikroskopie und Anisotropie-Messungen erlaubte es mir Rückschlüsse über deren Zugänglichkeit und Konfiguration innerhalb der Plasmamembran zu ziehen. Hierbei lokalisierten Azid-Gruppen am Ende kurzkettiger Fettsäurereste außerhalb des hydrophoben Membrankerns, wodurch sie mittels membran-undurchlässige Farbstoffe angeklickt werden konnten. Im Gegensatz dazu, waren Azide an längeren Fettsäureresten weniger zugänglich und konjugierte Farbstoffe tauchten tiefer in die Plasmamembran ein. Durch die Einführung photoreaktiver Diazirin-Gruppen oder chemisch modifzierbarer Amin-Gruppen wurden Wege geschaffen, welche eine Immobilisierung und anschließende Analyse mit Hilfe von dSTORM ermöglichen. Schließlich nutzte ich das spezifische Bindeverhalten der nicht toxischen B Untereinheiten von Shiga- (STxB) und Cholera-Toxin (CTxB) aus, um Glycosphingolipid Nanodomänen im Kontext einer Neisseria meningitidis Infektion zu untersuchen. Unter physiologischen Bedingungen waren diese homogen in der Plasmamembran verteilt, jedoch reicherten sich CTxB-detektierbare Ganglioside um eindringende Bakterien an. Darüber hinaus konnte ich einen Zusammenhang zwischen der zellzyklusabhängigen Expression von Glycosphingolipiden und dem Eindringen der Bakterien herstellen. Eine Absättigung der Zucker an der äußeren Membran durch CTxB-Vorbehandlung reduzierte die Anzahl von invasiven Bakterien signifikant und bestätigte die Schlüsselrolle von Gangliosiden bei der Aufnahme von Bakterien. Meine Ergebnisse legen Nahe, dass das Färbeverfahren für Sphingolipide an die jeweilige Fragestellung und Mikroskopietechnik angepasst werden sollte. Im Rahmen dieser Arbeit konnten neue Werkzeuge und Protokolle geschaffen werden, die die Charakterisierung von Sphingolipid-Nanodomänen mittels dSTORM für alle drei Färbeverfahren ermöglichen.

PURPOSE: It has been suggested in some studies that certain malocclusion features are related to Temporomandibular Joint (TMJ) clicking, which is a prevalent sign of Temporomandibular Disorders (TMD’s). This study aimed to evaluate different dental and skeletal malocclusion parameters and their relation to TMJ sounds. Also, to examine TMJ sounds with the presence of headache and TMJ pain using Diagnostic Criteria for Temporomandibular Disorders. MATERIALS & METHODS: A sample of 460 subjects seeking orthodontic treatment were evaluated using DC/TMD. Dental measures were recorded based on the initial records along with the clinical examination of the DC/TMD. Skeletal measurements were recorded after lateral cephalometric radiographs were traced. All measurements were confirmed before collection by one examiner using all the initial records. RESULTS: The sample was comprised of 283 females and 177 males. Clicking prevalence among the sample was 13%, of which 70% were females. Hispanic and Other group were significantly associated with opening and closing TMJ click. Class III dental was highly significant with TMJ click (OR: 0.35). Females who had headache had higher odds of having headache compared to males. Headache was significantly associated with all TMJ click variables (Open click [OR:10], lateral click [OR:10], self-reported click [OR:4.7]). Moreover, TMJ pain was significant with open click (OR:7.6), lateral click (OR:14.4), and self-reported click (OR:7.7). African-American group had 0.28 odds of having TMJ pain compared to Hispanics and Other. Finally, Males have 0.29 odds of having TMJ pain compared to females. CONCLUSION: In conclusion TMJ click upon opening and closing, lateral excursion, and self-reported click is highly associated with headache and chronic headache in general with a prevalence higher in females. Pain was highly associated with TMJ click of all sorts, with a higher prevalence in females and the Hispanic and other group. Finally, TMJ click was found more in the Hispanic and other group and class III dental occlusion subjects.