Στην παρούσα ερευνητική εργασία μελετάται η φωτοηλεκτροχημική διάσπαση δύο οργανικών ενώσεων: της χρωστικής Methylene Blue (MB), και της γλυκόζης. Η φωτοκαταλυτική διεργασία πραγματοποιήθηκε με φωτοβόληση υπεριώδους ακτινοβολίας UV (λάμπα Hg, 125 W). Για το σκοπό αυτό χρησιμοποιήθηκαν δύο φωτοκαταλύτες: η νανοκρυσταλλική τιτάνια (TiO2) και το οξείδιο του βολφραμίου (WO3). Η φωτοδιάσπαση των οργανικών ρύπων πραγματοποιήθηκε σε μία φωτοηλεκτροχημική κυψελίδα, η οποία αποτελείται από τα εξής μέρη: 1)Το ηλεκτρόδιο της ανόδου το οποίο φέρει το φωτοκαταλύτη. Στη φωτοάνοδο παράγονται τα ηλεκτρόνια και πραγματοποιόυνται οι αντιδράσεις οξείδωσης. 2)Το ηλεκτρόδιο της καθόδου, το οποίο φέρει τον ηλεκτροκαταλύτη, ο οποίος διευκολύνει τη μεταφορά των ηλεκτρονίων από το ηλεκτρόδιο στο διάλυμα. Στη φωτοκάθοδο πραγματοποιούνται αντιδράσεις αναγωγής. Ως ηλεκτροκαταλύτης χρησιμοποιήθηκε ο λευκόχρυσος ο οποίος είναι ευγενές μέταλλο. 3)Τον ηλεκτρολύτη, ο οποίος ρυθμίζει το pH του διαλύματος και αυξάνει την ιοντική αγωγιμότητα. Ο ηλεκτρολύτης που χρησιμοποιήθηκε είναι το καυστικό νάτριο (NaOH). Όταν ο φωτοκαταλύτης διεγείρεται με ακτινοβολία ενέργειας ίσης ή μεγαλύτερης του ενεργειακού του χάσματος, δημιουργούνται ζεύγη οπών-ηλεκτρονίων. Ένα μέρος των δημιουργούμενων ζευγών φορτίου επανασυνδέονται χάνοντας τη φωτεινή ενέργεια σε θερμότητα. Οι οπές οξειδώνουν το ρύπο απελευθερώνοντας ιόντα υδρογόνου. Τα ηλεκτρόνια ρέουν μέσω του εξωτερικού κυκλώματος στην κάθοδο, όπου αντιδρούν με τα ιόντα υδρογόνου, σχηματίζοντας είτε μοριακό υδρογόνο (υπό αναερόβιες συνθήκες), είτε νερό (υπό αερόβιες συνθήκες). Το πρώτο και σημαντικότερο στάδιο της φωτοκαταλυτικής διεργασίας είναι η προσρόφηση του ρύπου στην επιφάνεια του φωτοκαταλύτη. Ο μηχανισμός προσρόφησης γίνεται σύμφωνα με το κινητικό μοντέλο Langmuir-Hinshelwood. To TiO2 αποτελεί έναν από τους πιο διαδεδομένους και αποδοτικούς φωτοκαταλύτες. Τα υμένια TiO2 εναποτέθηκαν σε υπόστρωμα γυαλιού με τη μέδοδο Doctor Blade. Το WO3 είναι ένας εξίσου αποδοτικός φωτοκαταλύτης με το TiO2, αλλά λιγότερο δημοφιλής. Η εναπόθεση των υμενίων WO3 σε γυάλινα υποστρώματα έγινε με τη μέθοδο του ψεκασμού. Η παρασκευή του αντιηλεκτροδίου, δηλαδή του ηλεκτροδίου της καθόδου, έγινε με τη μέθοδο της ηλεκτροαπόθεσης. Το υψηλό pH του ηλεκτρολύτη (NaOH) είναι απαραίτητο για τη φωτοδιάσπαση οργανικών ενώσεων. Εκτός από την ιοντική αγωγιμότητα που προσφέρει στο φωτοηλεκτροχημικό κελί, επηρεάζει και την επιφανειακή φόρτιση του φωτοκαταλύτη. Η αύξηση της συγκέντρωσης του NaOH, δηλαδή η αύξηση των ιόντων ΟΗ-, είχε σαν αποτέλεσμα την αύξηση της σταθεράς ταχύτητας της φωτοκαταλυτικής αντίδρασης kapp και επομένως ταχύτερη φωτοδιάσπαση του ρύπου. Στα διαλύματα με τις μεγαλύτερες συγκεντρώσεις ηλεκτρολύτη ο χρόνος ημιζωής του ρύπου είναι πολύ μικρότερος συγκριτικά με τα διαλύματα χαμηλής συγκέντρωσης NaOH. Η μέτρηση της συγκέντρωσης των οργανικών ενώσεων στα υδατικά διαλύματα έγινε με φασματοφωτομετρία απορρόφησης ορατού-υπεριώδους (UV/vis). Οι φωτοαποικοδομούμενες ουσίες, λειτουργούν ως «θυσιαστήριες ενώσεις», αφού μειώνουν το ρυθμό επανασύνδεσης ηλεκτρονίων-οπών και επομένως συμβάλλουν στην αύξηση της απόδοσης του συστήματος, ενώ παράλληλα η διάσπασή τους προσφέρει τεράστιο περιβαλλοντικό όφελος. Από τις δύο οργανικές ενωσεις που μελετήθηκαν, μόνο η χρωστική Methylene Blue λειτούργησε αποτελεσματικά ως θυσιαστήρια ένωση. Αντιθέτως η γλυκόζη, που είναι πολύπλοκο μόριο, δεν κατάφερε να διασπαστεί. Τέλος έγινε σύγκριση της δραστικότητας των δύο φωτοκαταλυτών, κατά τη φωτοαποικοδόμηση των οργανικών ρύπων που μελετήθηκαν. Παρατηρήθηκε ότι και το TiO2 και το WO3 είναι εξίσου αποδοτικοί φωτοκαταλύτες. Σε αντίθεση με το TiO2, το WO3 δεν είναι ανθεκτικό στη φωτοδιάβρωση, καθιστώντας αδύνατη την επαναχρησιμοποίησή του σε περισσότερες από δύο φωτοκαταλυτικές διεργασίες. / The present study deals with the photo electrochemical degradation of two organic compounds, namely Methylene Blue and glucose. The photocatalytic process was carried out using UV radiation (Hg lamp, 125 W). The employed photo catalysts were titanium dioxide (TiO2) and tungsten oxide (WO3) deposited in the form of thin films on SnO2:F-coated glass. The photodecomposition of organic wastes was carried out in a photo electrochemical (PEC) cell with the following components: 1) The anode electrode which carries the photo catalyst. The photo anode produces electrodes and oxidation reactions take place there. 2) The cathode electrode, which carries the electro catalyst and facilitates the transfer of electrons from the cathode to the liquid phase. Reduction reactions take place at the cathode. In this study, a noble metal, Pt was used as electro catalyst. Thin films of Pt were obtained by electrodeposition on SnO2:F-coated glass slides. 3) The electrolyte which is added to adjust the Ph in order to increase the ionic conductivity. In this study, an aqueous solution of NaOH has been used as electrolyte. The operation of such a PEC cell is as follows: The absorption of photons by the photocatalyst leads to the creation of electron-hole pairs. The photodegradable substance is oxidized by the holes, liberating hydrogen ions in the aqueous solution. Electrons are transferred through the external circuit towards the cathode, where they reduce hydrogen ions producing hydrogen molecules (in the absence of oxygen). The initial step of the photoelectrocatalytic decomposition is the adsorption of the organic waste on the surface of the photocatalyst according to the Langmuir-Hinshelwood mechanism. TiO2 is among the most successful photo catalysts for heterogeneous photo catalytic degradation of organic wastes. Thin films of nano crystalline titania were deposited on glass substrates using the Doctor Blade method. Another wide band gap semiconductor with that can be used in heterogeneous photo catalysis is WO3. It was also tested and compared with TiO2. The pH value of the electrolyte (NaOH) was found to affect strongly the process. High pH values were required to obtain high OH- concentration because efficient hole scavenging and production of hydrogen radicals is ensured, especially when an organic sacrificial agent is added. As a consequence, the apparent rate constant kapp was increased with increasing NaOH concentrations. The photodegradable substances act like “sacrificial agents” preventing the recombination of electron-hole pairs, which is the main cause for low efficiencies. Of the two organic wastes that have been studied, only MB could be successfully degraded. Finally, the photo catalytic activity of TiO2 and WO3 was compared. Although both catalysts were equally efficient, WO3 is characterized by low stability. .

Thesis (M.Sc.(Chemistry)) -- University of Limpopo, 2018. / Refer to the document / NRF-Sasol Inzalo Foundation

Sputum induction by inhalation of hypertonic saline has been used for more than15 years. It has become one of the most intriguing methods to study airway inflammation. It is the only direct, non-invasive method for measuring airway inflammation indices.Sputum induction has been used in the diagnosis of many respiratory illnesses including asthma, chronic pulmonary obstructive disease, tuberculosis, chronic cough, lung cancer and Pneumocystis Carinii on patients who are unable to produce sputum spontaneously. There are currently many different methods used worldwide to induce sputum, but there is a lack of one generally accepted gold standard method. The proposed protocols for sputum induction proved to be safe, simple and produced satisfactory amount of expectorate. However, it did not contain enough cells from the lower respiratory tract and was contaminated by squamous cells when compared to another method based on the work of F. E. Hargreave. Investigation demonstrated that the use of impulse oscillometry, which requires no effort from patients, needs further research with larger study samples before it could be used instead of spirometry to evaluate airway obstruction. Initial methylene blue stain of the fresh expectorate smear was shown to be useful tool for identifying grossly contaminated sputum samples by squamous epithelial cells.Our first study group included 20 volunteers in good health. Sputum was induced by inhalation of 3% saline mist created by ultrasonic nebulizer at maximum output (4ml/min). Sputum induction intervals lasted 4-5 minutes with cumulative duration of induction about 4-15 minutes which was tolerated well. Lung function was evaluated for obstruction at baseline and every 5 minutes with spirometry and impulse oscillometry.The whole expectorated sample was processed and slides were stained with HEMA 3stain. With this method we were able to collect a mean of 6.1 ml expectorate. The mean total cell count was 804 000 with high proportion of squamous cells. The second study group included 5 volunteers in good health. This method utilized 3%, 4% and 5% saline mist for inhalation, 7 minutes each. Ultrasonic nebulizer was set at low output of 0.9 ml/min. This procedure was also tolerated well without major adverse effects. Lung function was evaluated at baseline and every 7 minutes for obstruction. Only dense portions of expectorate were selected and processed. Slides were stained with Wright stain. This method produced much more total cells with a mean of 3 385 000 per gram of sputum which came from the lower airways and were not contaminated by squamous cells. The second method was far superior producing adequate sputum sample with cells from the lower airways and minimal squamous cell contamination and will be used in our Breath Lab.

Malaria is a challenging infection with increasing and wide-spread treatment failure risk due to resistance. With a estimated death toll of 1-3 Million per year, most cases of Malaria affect children under the age of five years in Sub-Saharan Africa. In this thesis, I analyse the current status of malaria control (focussing on diagnosis and therapy) in Burkina Faso to show how this disease burdens public health in endemic countries and to identify possible approaches to improvement. MB is discussed as a therapeutic option under these circumstances. Burkina Faso is used as a representative example for a country in Sub-Saharan Africa with high endemicity for malaria and is here portrayed, its health system characterised and discussed under socioeconomic aspects. More than half of this country’s population live in absolute poverty. The burden that malaria, especially treatment cost, poses on these people cannot be under-estimated. A retrospective study of case files from the university pediatric hospital in Burkina Faso’s capital, Ouagadougou, shows that the case load is huge, and especially the specific diagnosis of severe malaria is difficult to apply in the hospital’s daily routine. Treatment policy as proposed by WHO is not satisfactorily implemented neither in home treatment nor in health services, as data for pretreatment clearly show. In the face of growing resistance in malaria parasites, pharmacological combination therapies are important. Artemisinins currently are the last resort of malaria therapy. As I show with homology models, even this golden bullet is not beyond resistance development. Inconsidered mass use has rendered other drugs virtually useless before. Artemisinins should thus be protected similar to reserve antibiotics against multi-resistant bacteria. There is accumulating evidence that MB is an effective drug against malaria. Here the biological effects of both MB alone and in combination therapy is explored via modeling and experimental data. Several different lines of MB attack on Plasmodium redox defense were identified by analysis of the network effects. Next, CQ resistance based on Pfmdr1 and PfCRT transporters as well as SP resistance were modeled in silico. Further modeling shows that MB has a favorable synergism on antimalarial network effects with these commonly used antimalarial drugs, given their correct application. Also from the economic point of view MB shows great potential: in terms of production price, it can be compared to CQ, which could help to diminuish the costs of malaria treatment to affordable ranges for those most affected and struk by poverty. Malaria control is feasible, but suboptimal diagnosis and treatment are often hindering the achievment of this goal. In order to achieve malaria control, more effort has to be made to implement better adjusted and available primary treatment strategies for uncomplicated malaria that are highly standardised. Unfortunately, campaigns against malaria are chronically underfinanced. In order to maximize the effect of available funds, a cheap treatment option is most important, especially as pharmaceuticals represent the biggest single matter of expense in the fight against malaria. / Malaria ist eine Krankheit, die uns vor große Herausforderungen stellt. Insbesondere die weltweit verbreiteten Resistenzen, die viele Therapieoptionen nutzlos werden lassen, haben den Kampf gegen die Malaria in den letzten Jahrzehnten deutlich verkompliziert. Schätzungen gehen davon aus, dass Malaria jährlich 1 bis 3 Millionen Todesopfer fordert. Mortalität und Morbidität der Erkrankung konzentrieren sich dabei in besonderer Weise auf Kinder unter fünf Jahren in Afrika südlich der Sahara. In der hier vorgestellten Doktorarbeit analysiere ich den aktuellen Stand der Malaria-Kontrolle in Burkina Faso und zeige beispielhaft auf, warum diese Krankheit eine derart große Bürde für die Volksgesundheit darstellt und wo Ansatzpunkte zur Verbesserung der Kontrollmaßnahmen zu sehen sind, mit einem besonderen Fokus auf Diagnostik und Therapieoptionen. Dabei wird MB als Therapieoption genauer beleuchtet. Um die besonderen Gegebenheiten eines Landes wie Burkina Faso - welches hier als repräsentatives Beispiel für einen Staat mit hoher Endemizität für Malaria herangezogen wird - aufzuzeigen, wird ein Porträt des Landes und seines Gesundheitssystems insbesondere unter Sozio- Ökonomischen Gesichtspunkten gezeichnet. Burkina Faso ist ein sehr armes Land, über die Hälfte seiner Bevölkerung lebt unterhalb der Armutsgrenze. Die Kosten von Malaria sind für diese Menschen gigantisch, und insbesondere die Kosten von Medikamenten wiegen schwer. Eine retrospektive Studie aus Fallakten des Universitäts-Kinderkrankenhauses in Burkina Fasos Hauptstadt Ouagadougou zeigt vor allem, dass allein die Fallzahlen überwältigend sind, und vor allem die spezifische Diagnose der schweren Verlaufsform der Malaria ist unter den vorherrschenden Bedingungen eine Mammutaufgabe. Die Behandlungsvorschriften wie von der WHO vorgegeben werden weder vom Gesundheitssystem noch von der Therapie zu Hause erfüllt, wie in den präsentierten Daten für die Vorbehandlung zeigen. Die zur Verfügung stehenden Malaria-wirksamen Therapeutika sind leider dank Resistenzentwicklung - oft durch unbedachten Masseneinsatz verursacht - sehr begrenzt. Artemisinine sind momentan das einzige Mittel gegen welches noch keine Resistenzen im Feld nachgewiesen wurden. Mittels Homologie-Modellierung zeige ich auf wie einfach eine solche Resistenzentwicklung jedoch denkbar wäre. Artemisinine sollten daher durch sehr gezielten Einsatz als ”letzter Trumpf” möglichst lange vor Resistenzentwicklung geschützt werden, ähnlich wie Reserveantibiotika gegen Multi-resistente Keime. MB ist ein hervorragender Kandidat für eine Kombinationsbehandlung gegen Malaria und eventuell eine Option, Artemisinine länger zu ”schonen”. Hier wird dieses Medikament mit bioinformatischen Mitteln genauer in seinen Wirkmechanismen beleuchtet und in Kombination mit anderen Medikamenten getestet mittels einer experimentell gestützten bioinformatischen Pathway-Modellierung. Durch diese Netzwerk-Analyse wurden verschiedene Angriffspunkte von MB auf das Redox-Netzwerk der Malariaerreger identifiziert. Daraufhin wurden CQ und SP-Resistenzen in silico simuliert. Weitere Analysen zeigten dabei, dass MB synergisitische Wirkungen mit anderen Therapeutika gegen Malaria aufzeigt, wenn sie zielgerichtet eingesetzt werden. Finanziell gesehen hat MB Potenzial, ein zweites CQ zu werden, und somit endlich wieder die Kosten der Behandlung für Menschen die in Armut leben erschwinglich zu machen. Malaria Kontrolle ist erreichbar, aber suboptimale Diagnosestellung und Behandlung behindern das Erreichen dieses Zieles. Hierfür muss eine angepasste, dezentrale und hochgradig standardisierte Primärbehandlung unkomplizierter Malaria implementiert werden und für eine bessere Verfügbarkeit dieser gesorgt werden. Leider leidet die Finanzierung der Kampagnen gegen Malaria an chronischer Unterversorgung. Um den maximalen Nutzen aus den vorhandenen Mitteln ziehen zu können ist eine günstigere medikamentöse Therapie ein entscheidender Beitrag, zumal Medikamente den größten Einzelbetrag im Kampf gegen Malaria verbrauchen.

Nanostructured molybdenum trioxide (MoO3) was synthesized and used as a precursor in a comparative study, along with commercial MoO3, to synthesize molybdenum dioxide (MoO2) nanoparticles. Scanning electron microscope (SEM) images revealed the particles to be approximately 30-50 nm in diameter. X-ray diffraction (XRD) confirmed MoO3 was fully reduced to MoO2 in all cases. Time dependent experiments showed that within two hours no traces of MoO3 are present. All of the experiments showed the materials were excellent absorbent materials, as well as photocatalysts. Both MoO2 materials performed almost exactly the same, with both samples being able to remove 100% of the methylene blue (MB) in one minute with light, and in two minutes without light. The morphology of MoO2 was controlled in a comparative study by varying the concentration of cetyltrimethylammonium bromide (CTAB) present during the hydrothermal reaction. As the concentration of CTAB increased, the morphology of the material changed from nanoparticles, to nanospheres, to microspheres, to hollow microspheres, and finally a highly agglomerated version of microspheres and particles combined, as confirmed by SEM images. A formation mechanism for the formation of the various sized spheres was proposed with a combination of aggregation and Ostwald ripening. XRD confirmed that all of the MoO3 was reduced to MoO2, along with no residual peaks from the CTAB that was present during the reaction. Upon trying to mix some of the materials into the MB solutions, it became obvious that some of the materials were hydrophobic. The decontamination results once again showed that the synthesized MoO2 materials were not only photocatalysts, but adsorbents as well. Samples synthesized with 0.1-5 mM CTAB were able to remove 100% of the MB in 10 minutes or less. Samples synthesized with 10 mM CTAB were able to remove 54.4% and 35% of the MB in 10 minutes, with and without light, respectively. Samples synthesized with 15 mM CTAB were able to remove 29.4% and 26.3% of the MB in 10 minutes, with and without light, respectively. The apparent decrease in decontamination performance was proposed to be caused by surface morphology induced hydrophobicity. A mechanism to describe why the hydrophobic particles were still able to decontaminate the water was proposed to be caused by coming into direct contact with the magnetic stirrer as the water level dropped due to sample collection. MoO2 nanoparticles were successfully synthesized onto a copper substrate, in a single step, via a hydrothermal synthesis technique. It is believed to be the first report of such a synthesis method. XRD confirmed all of the MoO3 had been reduced to MoO2, and also confirmed that no other compounds had formed between the molybdenum and copper. SEM images of the MoO2 coated copper substrate showed uniform nanoparticles ranging from 30-50 nm. The MoO2 coated copper substrate was able to decontaminate 57.5% of the MB from water in 10 minutes without exposure to light, while it was able to decontaminate 71.7% of the MB from water in 10 minutes with exposure to light.

The elderly are at increased risk for developing psychiatric diseases, which include Alzheimer's disease, depression, anxiety and suicide. The probability of multiple disease comorbidity is also increased in the elderly. At the cellular level, the loss of protein homeostasis is often at the root of disease emergence, and thus the scientific community is searching for ways to help maintain this balance. A vast group of proteins that are paramount to balancing and counterbalancing protein levels is the molecular chaperone protein group, which has evolved a tremendous variety of functions in the cell. They aid in protein trafficking, folding, receptor signaling, neurotransmission, vesicle forming and fusion, protein degradation, and apoptosis, among other activities. Despite their best efforts, disease still ensues, but because of their vast number and multiple abilities, it may be possible to modulate these proteins as a way to treat and prevent disease. Chaperones are of particular interest in diseases of aging, because chaperone induction and effectiveness is reduced with age. In addition, many diseases of the elderly are brought on by aberrant protein accumulation, like Alzheimer's disease. As a result, the hypothesis of this dissertation is whether the modulation of molecular chaperones changes disease pathology. A molecular chaperone family that is important to protein degradation is the Hsp70 chaperone complex. Hsp70 proteins have specialized function depending on cell type and cellular compartment, but Hsp70 proteins are very important for protein synthesis and degradation. As a result, they are in a position to contribute to the regulation of proteins that become aberrant. In recent years scientific literature has indicated that compounds that inhibit the enzymatic ATP hydrolysis of these proteins promote tau degradation, which accumulates in Alzheimer's disease. Alzheimer's disease is the sixth leading cause of death in the U.S., it is a progressive neurodegenerative disease, and is caused by the aberrant accumulation of the amyloid beta and tau proteins. Here, we show that treatment with the Hsp70 inhibitor methylene blue, reduces tau, saves neurons, and restores cognition, in a mouse model of tau accumulation (rTg4510). Cognitive rescue occurred despite a severe tangle load, equal to control treated tau transgenic mice. This study shows that reducing soluble tau can restore cognition, reducing tangles is not necessarily to ameliorate cognition, and saving neurons is not sufficient to increase cognition if they are burdened with soluble tau. This work shows that methylene blue does not affect the the number of tau tangles in this model, as suggested by in vitro data. It also suggests that further work into the development of Hsp70 ATPase inhibitors may find success in alleviating the soluble tau burden found in Alzheimer's disease. The co-chaperone FKBP5 is also of extreme importance, not because it is essential, but because research has implicated this protein with a host of psychiatric diseases. Single nucleotide polymorphisms in this gene, which increase the levels of FKBP5, interact with averse traumatic events to enhance the likelihood of developing mood and anxiety disorders, including major depressive disorder, post-traumatic stress disorder, bipolar disorder, and suicide. Moreover, we have found that FKBP5 protein levels increase with age in the human brain, increasing the risk for the elderly of developing disease if exposed to traumatic stress. Here, we tested the hypothesis that FKBP5 negatively regulates resilient behavior. We found that FKBP5 levels increase with age in the wild type mouse brain, and that wild type mice display reduced resiliency with age. FKBP5-/- mice, on the other hand, show enhanced resiliency to stress at all ages tested, and are protected from aging-induced despair. At the molecular level, FKBP5 is a robust inhibitor of the glucocorticoid receptor, which is responsible for the shut-off of the hypothalamic-pituitary-adrenal axis. In addition, excess glucocorticoid levels in the blood is a robust marker of psychiatric disease. Consequently, FKBP5 may be causing disease through enhanced levels of glucocorticoids. FKBP5-/- mice display reduced corticosterone after stress. Moreover, corticosterone production increases with age, and FKBP5-/- mice are protected from this increase. These studies are the first to show that reducing the levels of FKBP5 is a promising therapeutic option for the treatment of mood disorders in the elderly, resiliency naturally declines with age due to FKBP5, corticosterone levels after stress rise due to FKBP5, and that the ablation of this gene increases resiliency and prevents aging- induced despair. As a whole, these data show that the modulation of chaperone proteins has the potential for developing new therapies for the treatment of psychiatric diseases of the elderly.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

In this research, the use of gold nanostructures (AuNS) was explored to evaluate the interaction between molecules and the nanoparticle (NP) surface. In that way, three different projects were developed; one project using fluorescence and two projects using Raman spectroscopy as measuring technique. The fluorescence spectroscopy project used the fluorescence lifetime imaging microscope (FLIM) to evaluate the relative position of the molecules methylene blue (MB) and cucurbit[7]uril (CB) on the gold nanoparticle (AuNP) surface. Although the inclusion complex is favored in solution, it was found that MB forms an exclusion complex with CB, when CB is attached to the AuNP surface. The first project utilizing Raman spectroscopy, specifically surface enhanced Raman scattering (SERS), took advantage of a confined system (a reverse micelle) to evaluate the Raman signal of water molecules in close proximity to the AuNP surface. It was observed that the SERS water signal had a big shift to higher energies compared with the Raman signal of the bulk water; indicating the water molecules in the system are subjected to different bond-stretching energies. The second Raman project studied the modification of two different AuNS (specifically AuNP and gold nanorod -AuNR) with thiols. Different thiols were used to evaluate the kinetics of the modification of the AuNS surface, also the different AuNS presented different ligands on their surface. In general, and considering the difference in the bonding strength of the ligands present on the AuNS surface (by synthesis) and the size of the thiol, at least 2 h are required to modify the complete AuNS surface.

Submitted by Programa de Pós-graduação em Biotecnologia (mebiotec.ufba@gmail.com) on 2017-04-06T12:35:58Z No. of bitstreams: 1 DISSERTACAO EVARISTO FINAL (1).pdf: 3619384 bytes, checksum: ce2f500cb5c5efadf38bd2d0f730d863 (MD5) / Approved for entry into archive by Delba Rosa (delba@ufba.br) on 2017-06-29T14:36:51Z (GMT) No. of bitstreams: 1 DISSERTACAO EVARISTO FINAL (1).pdf: 3619384 bytes, checksum: ce2f500cb5c5efadf38bd2d0f730d863 (MD5) / Made available in DSpace on 2017-06-29T14:36:51Z (GMT). No. of bitstreams: 1 DISSERTACAO EVARISTO FINAL (1).pdf: 3619384 bytes, checksum: ce2f500cb5c5efadf38bd2d0f730d863 (MD5) / CNPq / A leishmaniose é uma doença de grande relevância à saúde pública em que a Leishmania braziliensis é um dos agentes etiológicos. Seu tratamento é realizado através da administração de medicamentos considerados tóxicos às células humanas, caros e ineficientes às diversas espécies de Leishmania, podendo resultar em cepas resistentes e por essas razões, estudos que abordem novas terapias com vista a reduzir os efeitos indesejados são de suma importância. A terapia fotodinâmica (TFD), é uma das técnicas ditas como sendo promissoras no tratamento de inúmeras doenças parasitárias. Portanto, foi proposto este trabalho com o objectivo de avaliar os efeitos da TFD na L. braziliensis, bem como a interação deste parasito com macrófagos J774, utilizando como fotossensibilizador, o azul de metileno na concentração de 12,5 µg/mL associado ao LASER vermelho de baixa potência com λ = 660 nm; 40 mW; 8,4J /cm2. Os testes foram realizados em triplicata, e as amostras foram distribuídas em quatro grupos: Grupo Controle, Grupo Fotossensibilizador, Grupo LASER, Grupo TFD. Como métodos avaliativos da morfologia e ultraestrura das promastigotas face aos efeitos da TFD sobre a Leishmania, foram utilizadas as microscopias eletrônicas de varredura e de transmissão. Para a avaliação da interação, foi utilizada a microscopia ótica. Nela, foram realizadas contagens de macrófagos infetados e não infetados. Como resultado, foi observado que a TFD foi capaz de criar deformações morfológicas e estruturais compatíveis com alterações promovidas por ‘stress’ oxidativo. Após a analise dos ensaios de interação foi observado que a infecção de macrófagos no grupo TFD apresentou taxa de infecção menor que no controle com uma significância de p=0.0339 e p=0.0181 nos períodos respetivos de 24 e 48 horas. Aavaliação estatística foi realizada através do teste ANOVA com pós-teste de Tukey, p <0,05. Assim, conclui-se que a TFD além de ser eficaz em causar danos potencialmente letais à promastigotas de Leishmania braziliensis ela também, é capaz de estimular a resposta do sistema imune, desempenhando um papel sinergístico. / Leishmaniasis is a disease of great importance to public health in what Leishmania braziliensis is one of the etiological agents. The treatment is performed by administering drugs considered toxic to human cells, expensive and inefficient to several species of Leishmania and can result in resistant strains and for these reasons, studies that address new therapies to reduce the unwanted effects are of paramount importance. Photodynamic therapy (PDT) is a technique said to be promising in the treatment of many parasitic diseases. Therefore, we proposed this work aimed to evaluate the effects of PDT in L. braziliensis and the interaction of this parasite with J774 macrophages, using as a photosensitizer, methylene blue at a concentration of 12.5 µg/mL associated with red Low power LASER with λ = 660 nm; 40 mW; 8,4 J/cm2. The tests were performed in triplicate, and the samples were divided into four groups: control Group, photosensitizer Group, LASER Group and TFD Group. As evaluative methods of morphology and structure, promastigotes against the effects of PDT on Leishmania, electronic microscopy scanning and transmission were used. For the evaluation of the interaction, the optical microscope was used. Here, infected macrophage counts were performed and uninfected. As a result, it was found that PDT was able to create morphological and structural deformation compatible with alterations resulting Oxidative stress. After the analysis of the interaction tests was observed that infection of macrophages in the PDT group showed lower infection rate than the control with a significance of p = 0.0339 and p = 0.0181 in the respective periods of 24 and 48 hours. Statistical analysis was performed using ANOVA with Tukey's post-test, p <0.05. Thus, the conclution is that PDT is effective in causing potentially lethal damage to Leishmania braziliensis promastigotes it is able to stimulate the immune system response and plays a synergistic role.

Made available in DSpace on 2014-10-09T12:52:41Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:13Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP