Zugl.: Bielefeld, Univ., Diss., 2009

Stuttgart, Univ., Diss., 2004.

Universiẗat, Diss., 2003--Frankfurt (Main).

Universiẗat, Diss., 2002--Dortmund.

No description available.

In this investigation a number of post-genomic technologies have be applied to study the dermatological disorders of psoriasis and keloid disease. In spite of considerable research focus on these diseases the pathogenesis remains unclear and currently no cure is available however, both diseases are manageable by drug intervention. It is common place that patients who are suffering from skin disorders are diagnosed and the extent of the disease assessed by a dermatologist which may be subjective due to human error. The availability and application of methods to screen patients and quantify the level of disease or response to treatment has obvious benefits in disease management. The work has incorporated a two-pronged approach combining the spectroscopic analysis of excised tissue samples and the phenotypic profiling of a rapidly proliferating cell line in response to drug intervention. The initial analysis of psoriatic skin samples by MALDI-MS provided poor results which remain relatively unexplained; however similar problems have been observed by other research groups. In a complementary approach the HaCaT cell line was exposed to increasing concentrations of three anti-psoriatic drugs namely dithranol, methotrexate and ciclosporin and the cells profiled using both metabolomic and proteomic methods. A number of metabolic pathways were highlighted including glycolysis and the TCA cycle. This has resulted in a selection of potential biomarkers which could be investigated in further work. In a small follow on study a collection of plasma samples from patients undergoing methotrexate treatment were analysed. The level of patient metadata and the number of samples was relatively limiting however, a subset of metabolites were significantly altered between responders and non-responders and with further validation could be potential biomarkers of successful treatment. The analysis of excised keloid samples was conducted using FT-IR microspectroscopy where it was possible to successfully discriminate between keloid and normal tissue. The use of imaging FTIR illustrated the complex cellular composition within a keloid scar, with increased lipid, amide and phosphate levels being observed. These measurable variations could, in the future, be incorporated into surgical procedures to allow targeted excision ensuring all keloid areas are removed. Finally a SERS-based analysis was conducted to investigate the possibility of probing dynamic enzymatic processes. This was successful and with the use of varying reporter molecules could be a beneficial tool for the analysis of metabolic processes.This project has successfully used a number of bio-analytical techniques to investigate dermatological problems. While the ultimate goal would be the application of a single analytical technique to provide answers to biological questions, it has been found that a number of complimentary techniques and statistical data handling approaches can provide a valuable insight into the problems posed.

Prostate cancer is the second most common cause of cancer fatalities in males in the UK (2006) [1]. Therefore any advances in the diagnosis or screening for this form of cancer will yield significant benefits in the treatment of this disease. FT-IR has already been successfully used to assess and grade prostate biopsies by Gazi et al 2006 [2]. The collection of prostate biopsy is however a highly invasive procedure and as current screening methods are highly sensitive, but not very specific, large numbers of patients are referred for biopsy procedures that later come back as negative for prostate cancer [3]. Harvey et al used Raman spectroscopy to classify live cells of a number of prostate cell lines as a first step towards a possible urine screening protocol for prostate cancer [3]. Due to the complementary nature of Raman and FT-IR spectroscopy a similar live cell study should be possible using FT-IR and the combination of this technique with a high-throughput microfluidic device could lead to a useful screening tool for prostate cancer.The aim of the project was therefore to develop a microfluidic system which would enable higher through-put FT-IR analysis of live single cells in an aqueous carrier solution such as PBS or urine than has been previously possible. The design of the microfluidic device must also account for the fact that the materials used to produce the analysis chamber must be highly transparent to mid-IR radiation. The microfluidic device and peripheral systems must be easily transportable as it will be necessary to perform experiments in multiple locations. A design and manufacturing protocol for such a device has been developed.The development of a spectral contribution removal algorithm for the aqueous carrier fluid will also be necessary in order to allow the accurate interpretation of the IR data obtained. A least squares fitting based spectral subtraction algorithm was developed and validated for this purpose.Although it did not prove possible during the project to investigate the possible application of this device to a prostate cancer screening protocol other applications in cell line classification and drug cell interaction studies were performed and yielded encouraging results.

Une pénurie de C4 s'est produite au cours des dernières années en partie à cause de la révolution naissante du gaz de schiste. Le faible coût et la grande abondance de cette source d'énergie nouvellement découverte sont rapidement devenues un facteur de changement pour l'industrie chimique. Bien que la concurrence avec cette source d'énergie non renouvelable ne soit pas une tâche facile, ses lacunes, telles qu'une production minimale en C3 et en C4, créent de nouvelles opportunités pour les molécules biosourcées. Dans ce travail, nous rapportons la conversion nouvellement découverte du (bio) isobutanol en n-butènes sur un catalyseur zéolitique. Ce catalyseur conduit à un rendement exceptionnel en butènes linéaires, ce qui est paradoxal car la FER est un catalyseur bien connu pour l'isomérisation squelettale des butènes. Bien que la recherche sur le dernier ait débuté il y a 30 ans, aucune conclusion définitive n'a encore été faite sur le mécanisme dominant : une réaction de monomoléculaire ou un mécanisme de "carbon pool". Acquérir des connaissances plus approfondies sur ce sujet est alors nécessaire pour expliquer la sélectivité inattendue en n-butène de cette réaction.Un criblage de catalyseurs a confirmé la sélectivité supérieure de FER pour les n-butènes (81%). Ceci est une augmentation significative par rapport aux catalyseurs de déshydratation couramment utilisés, alumine  (1%) et MFI (23%). Comme la sélectivité en n-butène pour les deux zéolites est significativement plus élevée que pour l’alumine un premier indice est que l'environnement confiné et cristallin de la porosité de la zéolite est crucial pour la sélectivité du n-butène. Cependant nous avons démontré que l'isobutanol est incapable d'accéder aux micropores de la structure FER; sa déshydratation doit donc se produire sur la surface externe de la zéolithe, en particulier sur ses sites acides de Brønsted.Nous avons déterminé l'identité du site actif responsable de l'isomérisation. En raison des similitudes avec la réaction d'isomérisation squelettale de du butène 1 à l'isobutène, un mécanisme de "carbon pool" a dû être envisagé. Cependant, aucun lien n'a été trouvé entre ces espèces et l’évolution de la sélectivité du n-butène, ne permettant pas de conclure quant à la participation de ces espèces carbonées comme sites actifs d'isomérisation. Par la suite, nous avons cherché à déterminer si les n-butènes sont formés directement ou via un mécanisme de type râteau dans lequel l'isobutène serait un intermédiaire. Nous avons établi que les constantes de vitesse pour l'isomérisation individuelle des butènes sont très inférieures à la constante de vitesse globale, excluant ainsi le mécanisme de type râteau. Par conséquent, le site actif d'isomérisation doit être identique ou situé à proximité du site actif de déshydratation pour éviter la désorption des espèces intermédiaires de surface sous forme d’isobutène. Nous avons ensuite démontré la nécessité d'une densité minimale d'acidité de Brønsted externe pour une sélectivité élevée en n-butène, également valable pour différentes zéolites, (10 MR ZSM-5 et ZSM-22 et 8 MR Erionite). Ces résultats nous ont ainsi amener à conclure que la sélectivité exceptionnelle des zéolithes de type FER en n-butène est le résultat de leur forte densité de sites acide de Brønsted externes. Cependant, une trop forte densité a un effet indésirable en terme de désactivation.L’ensemble de ces résultats nous permet de conclure que le catalyseur idéal doit présenter une densité de site d'acide de Brønsted externe très spécifique, suffisamment importante pour produire une sélectivité élevée en n-butène tout en évitant une désactivation excessive. Alors que les sites acides de Brønsted internes ne semblent pas jouer le rôle de site actifs pour la transformation de l'isobutanol en butènes linéaires, il n’est pas exclus qu’elle ait un impact sur le taux de formation des espèces carbonées. / A C4-shortage has been arising during the recent years partly as a result of the nascent shale gas revolution. The low cost and vast abundance of this newly discovered energy source rapidly became a game changer for the chemical industry. Although competing with this non-renewable energy source is not an easy task, its shortcomings such as a minimal C3 and C4 production, are creating new opportunities for bio-based molecules. In this work, we report on the newly discovered conversion of (bio)isobutanol to n-butenes over a zeolitic (ferrierite, FER structure) catalyst. It displays an exceptional yield in linear butenes. However, this is remarkable since FER is a well-known catalyst for the skeletal isomerisation of n- towards iso-butene. Although research on the n- to iso-butene skeletal isomerisation started 30 years ago, no firm conclusion has yet been made on the prevailing mechanism: a monomolecular reaction or a carbon pool mechanism. Acquiring deeper knowledge on this topic is required to explain the unexpected n-butene selectivity of this reaction. A screening of catalysts confirmed the superior selectivity of FER for n-butenes (~ 80 %). This is a significant increase compared to the commonly used dehydration catalysts, γ-alumina (~ 1 %) and MFI (~ 25 %). Since n-butene selectivity for both zeolites is significantly higher, a first hint is found that the confined and crystalline zeolite environment should be crucial for n-butene selectivity. However, we have demonstrated that isobutanol is unable to access the micropores of the FER structure; its dehydration must therefore occur on the external surface, in particular its acidic Brønsted sites.We have determined the identity of the active site responsible for isomerisation. Due to similarities with the 1- to isobutene skeletal isomerisation reaction, a carbon pool mechanism had to be considered. However, no correlation was found, hence allowing to exclude the carbonaceous species as possible isomerisation active sites. Next, we have investigated whether the n-butenes are formed directly or via a rake-type mechanism where isobutene is an intermediate. We have established that the rate constants for the individual butene isomerisation are lower than the over-all rate constant of iso-butanol transformation to n-butenes, thus excluding the rake-type mechanism. Hence, either dehydration-isomerisation occur in the same site or isomerisation occurs on a site located in the immediate neighbouring of the dehydration site in order to avoid the desorption of intermediate species as isobutene. With this respect, we have subsequently demonstrated the requirement of a minimal external Brønsted acid density for a high n-butene selectivity. Strikingly, the latter held also for different zeolites, (10 MR ZSM-5 and ZSM-22 and 8 MR Erionite) which suggests a general trend relating the n-butene selectivity to the density of external Brønsted acid sites with the existence of a “critical threshold” of external BAS density beneath which the selectivity towards n-butene is severely degraded. We concluded that the exceptional n-butene selectivity of FER is a result of its high external Brønsted acid density. However, an adverse effect was observed on isobutanol conversion as a high density of external sites is also linked to a faster deactivation. Additionally, we have determined that the selectivity for a secondary set of products, octenes, decreased with increasing the external Brønsted sites density; isolated external Brønsted acid sites should therefore function as active sites for octene formation.Finally, we conclude that the ideal catalyst should contain a very specific external Brønsted acid site density, sufficiently dense to produce high n-butene selectivity while avoiding excessive deactivation. While internal Brønsted acidity does not function as active sites for the one-step transformation, it is not excluded that they can impact the rate of carbonaceous species formation

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-01-26T14:34:24Z No. of bitstreams: 1 2016 - Danielle Affonso Sampaio.pdf: 3006939 bytes, checksum: 839c5d77a13fd99ad3c749c33dc2530a (MD5) / Made available in DSpace on 2017-01-26T14:34:25Z (GMT). No. of bitstreams: 1 2016 - Danielle Affonso Sampaio.pdf: 3006939 bytes, checksum: 839c5d77a13fd99ad3c749c33dc2530a (MD5) Previous issue date: 2016-05-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Seed integument plays an important role in the plant life cycle, monitoring the embryo development and germination. Informations about cell structure and physico-chemical characteristics of the Araucaria angustifolia seed coat are important to its correct functional interpretation. Thus, the aim of this study was the anatomical and physico-chemical characterization of the Araucaria angustifolia seed integument. Anatomical features were observed using different microscopy techniques (brightfield microscopy, fluorescence microscopy and scanning electron microscopy) and histochemical tests (Lugol, Wiesner, Sudan IV and potassium dichromate ? K2Cr2O7). Chemical analysis included the extractive, holocelulose and Klason lignin contents (untreated and treated with sodium hydroxide ? NaOH). Functional groups of the integument layers and lignin were observed by Fourier transformed infrared spectroscopy using a VARIAN 640-IR FT-IR spectrometer. Colour analyses were performed in CIE 1976 L*a*b* space colour according to ISO 11664-4:2008 standard using CM 2600d spectrometer. Wettability of the layers was evaluated by contact angle analysis with the drop shape analyser DSA 100. The Araucaria angustifolia seed integument is composed by three distinct layers: exotesta, mesotesta and endotesta. The layers have different chemical and anatomical characteristics. Lignin structure of the integument layers was classified as guayacil (G) type. The endotesta was the layer with higher chromaticity due to higher extractive content and phenolic substances. The wettability varied between layers according to ther strusture. The results of this study contribute to a better understanding of the functioning of the Araucaria angustifolia seed integument and corroborate to future studies on seed physiology / O tegumento de semente desempenha um papel importante no ciclo de vida do vegetal, controlando o desenvolvimento do embri?o e a germina??o. O conhecimento da estrutura celular e das caracter?sticas f?sico-qu?micas do tegumento da semente de Araucaria angustifolia ? importante para a correta interpreta??o funcional do mesmo. Sendo assim, o objetivo deste estudo consistiu na caracteriza??o anat?mica e f?sico-qu?mica do tegumento da semente de Araucaria angustifolia. As caracter?sticas anat?micas foram observadas atrav?s de diferentes t?cnicas de microscopia (microscopia de campo claro, microscopia de fluoresc?ncia e microscopia eletr?nica de varredura) e testes histoqu?micos (Lugol, Wiesner, Sudan IV e dicromato de pot?ssio ? K2Cr2O7). Nas an?lises qu?micas, determinou-se os teores de extrativos, holocelulose e lignina de Klason tratada e n?o-tratada com hidr?xido de s?dio ?NaOH. Os grupos funcionais das camadas do tegumento e da lignina foram observados por espectroscopia no infravermelho por transformada de Fourier atrav?s do espectr?metro VARIAN 640-IR FT-IR. As an?lises colorim?tricas foram realizadas no espa?o de cor L*a*b* CIE 1976 segundo a norma ISO 11664-4: 2008 utilizando o espectrofot?metro CM 2600d. A molhabilidade das camadas foi avaliada atrav?s de an?lises de ?ngulo de contato com o sistema de formato da gota DSA 100. O tegumento da semente de Araucaria angustifolia ? composto por tr?s camadas distintas: exotesta, mesotesta e endotesta. As camadas apresentam caracter?sticas qu?micas e anat?micas distintas. A estrutura da lignina das camadas do tegumento foi classificada como guaiac?lica (G). A endotesta foi a camada com maior cromaticidade devido ao maior teor de extrativos e subst?ncias fen?licas. A molhabilidade variou entre as camadas em fun??o da sua estrutura. Os resultados deste estudo contribuem para uma melhor compreens?o do funcionamento do tegumento da semente de Araucaria angustifolia, podendo corroborar com estudos futuros sobre a fisiologia da semente

Šiame darbe nagrinėjami radiaciniai defektai bei jų tarpusavio reakcijos silicyje. Atlikti eksperimentai, kurių metu pasitelkus minkštąją Rentgeno spinduliuotę buvo generuojami defektai. Vėliau bandiniai buvo tiriami FT-IR spektroskopijos metodais. Darbo apimtis 52 puslapiai. Darbas susideda iš 5 dalių. Pirmoje dalyje apžvelgiami Rentgeno spinduliuotės šaltiniai ir spinduliuotės savybės. Antroje - dalyje radiaciniai defektai silicyje. Trečioje - defektų tyrimo metodai. Ketvirtoje - dalyje defektų reakcijos. Penktoje - eksperimento metodika ir eksperimento rezultatai. / In this work, we are researching radiation defects and their reactions in silicon. During experiments defects were generated using soft Rentgen radiance. Later samples were researched using FT-IR methods of spectroscopy. Work amount is 52 pages. Work consists from 5 parts. First part - overview of sources and features of Rentgen radiance. Second part – radiation defects in silicon. Third part – methods of defect researching. Fourth part – reactions of defects. Fifth part – Methods and results of experiment.