Pelchem, a commercial subsidiary of Necsa (South African Nuclear Energy Corporation), produces a range of commercial fluorocarbon products while driving research and development initiatives to support the fluorine product portfolio. One such initiative is to develop improved analytical techniques to analyse product composition during development and to quality assure produce. Generally the C–F type products produced by Necsa are in a solution of anhydrous HF, and cannot be directly analyzed with traditional techniques without derivatisation. A technique such as vibrational spectroscopy, that can analyze these products directly without further preparation, will have a distinct advantage. However, spectra of mixtures of similar compounds are complex and not suitable for traditional quantitative regression analysis. Multivariate data analysis (MVA) can be used in such instances to exploit the complex nature of spectra to extract quantitative information on the composition of mixtures. A selection of fluorocarbon alcohols was made to act as representatives for fluorocarbon compounds. Experimental design theory was used to create a calibration range of mixtures of these compounds. Raman and infrared (NIR and ATR–IR) spectroscopy were used to generate spectral data of the mixtures and this data was analyzed with MVA techniques by the construction of regression and prediction models. Selected samples from the mixture range were chosen to test the predictive ability of the models. Analysis and regression models (PCR, PLS2 and PLS1) gave good model fits (R2 values larger than 0.9). Raman spectroscopy was the most efficient technique and gave a high prediction accuracy (at 10% accepted standard deviation), provided the minimum mass of a component exceeded 16% of the total sample. The infrared techniques also performed well in terms of fit and prediction. The NIR spectra were subjected to signal saturation as a result of using long path length sample cells. This was shown to be the main reason for the loss in efficiency of this technique compared to Raman and ATR–IR spectroscopy. It was shown that multivariate data analysis of spectroscopic data of the selected fluorocarbon compounds could be used to quantitatively analyse mixtures with the possibility of further optimization of the method. The study was a representative study indicating that the combination of MVA and spectroscopy can be used successfully in the quantitative analysis of other fluorocarbon compound mixtures. / Thesis (M.Sc. (Chemistry))--North-West University, Potchefstroom Campus, 2012.

Die Nah-infrarot-Spektroskopie (NIRS) bestimmt kontinuierlich und nicht-invasiv anhand der Absorptionsänderung von nah-infrarotem Licht den Oxy- und Desoxyhämoglobingehalt sowie den Redoxstatus von Cytochrom a/a3 im Gewebe. Veränderungen von zerebralem Oxy- und Desoxyhämoglobingehalt und der daraus abgeleiteten Parameter reflektieren vor allem den venösen Sauerstoffstatus des Gehirns. Sie können ein früher und sensitiver Indikator für eine zerebrale Hypoxie sein. Der Redoxzustandes von Cytochrom a/a3 gibt als Korrelat des zerebralen Energiezustandes Hinweise auf ein kritisches Sauerstoffdefizit. Ziel der Untersuchung. In der experimentellen und klinischen Studie sollten mit einem kommerziell erhältlichen Gerät die Eignung der NIRS zur Überwachung des zerebralen Sauerstoffstatus während Anästhesie und Intensivtherapie bei Hund und Katze, die Messqualität, die auftretenden technischen Probleme und die darstellbaren Ereignisse geprüft werden. In der experimentellen Studie sollten die Veränderungen der zerebralen Oxygenierung und des Redoxzustandes von Cytochrom a/a3 nach verschiedenen zur Narkoseeinleitung beim Hund etablierten Protokollen sowie nach deren Antagonisierung ebenso untersucht werden wie der Zusammenhang der mittels NIRS erfassten Parameter mit denen des pulmonalen Gaswechsels und der Herz-Kreislauf-Funktion. Material und Methoden. In der klinischen Studie wurden Daten von 33 Hunden und 4 Katzen während Anästhesie oder Intensivüberwachung aufgezeichnet. Die experimentelle Studie wurde an 84 Foxhounds und 32 Beagle mit einem mittleren Alter von 12,96 Monaten (STD 13,42; 6,33–94,43 Monate) und einer mittleren Körpermasse von 24,76 kg (STD 6,6; 12,7–43 kg) durchgeführt, die zufällig auf vier Versuchsgruppen verteilt wurden. Die Sensorapplikation erfolgte in beiden Studien in Höhe der Ohrbasis auf geschorener Haut. Versuchsgruppen und –ablauf der experimentellen Studie: Gruppe Acepromazin/l-Methadon(AM): Narkoseeinleitung 0,1 mg/kg KM Acepromazin und 0,5 mg/kg KM l-Methadon i.v., keine weitere Erhaltung Gruppe Diazepam/l-Methadon(DM): 0,5 mg/kg KM Diazepam und 0,5 mg/kg KM l-Methadon i.v., keine weitere Erhaltung Gruppe Medetomidin/l-Methadon(MM): 40 mikrog/kg KM Medetomidin und 0,5 mg/kg KM l-Methadon i.v., keine weitere Erhaltung Propofol(P): Einleitung 0,1 mg/kg KM Propofol i.v., Erhaltung in dieser Gruppe 0,3 mg/kg/min Propofol i.v. In den Gruppen AM, DM und MM Antagonisierung 8 mikrog/kg KM Naloxon i.v. 30 min nach Einleitung, in der Gruppe MM zusätzlich 200 mikrog/kg KM Atipamezol i.v. 5 min später Kontinuierliche Überwachung von Herzfrequenz, EKG, Temperatur, invasiver Blutdruck,Pulsoxymetrie, Nah-infrarot-Spektroskopie. Blutgasanalyse 0, 5, 10, 15, 20, 25, 30 min nach Einleitung, 0, 2, 7 min nach Antagonisierung/Propofol-Ende Ergebnisse. Die Nah-infrarot-Spektroskopie ist prinzipiell bei Hund und Katze anwendbar, nicht jedoch bei schwarzhaarigen Tieren. Hauptprobleme sind Sensorbefestigung, Bewegungsartefakte und mangelnde Signalqualität. In der experimentellen Studie besteht im Mittel zu 80 % der ausgewerteten Zeit eine gute Messqualität. 14 % der Messungen sind ohne Störung, bei 17 % tritt in mehr als 50 % der Messzeit eine Störmeldung auf. Vor Narkoseeinleitung beträgt die regionale zerebrale Sauerstoffsättigung etwa 65 % (n=109, STD 7 %). Schon 1 Minute nach Einleitung bestehen signifikante Gruppenunterschiede. In Gruppe P steigt die zerebrale regionale Sauerstoffsättigung um etwa 8 %, sie fällt in Gruppe AM um 5 %, in Gruppe DM um bis zu 10 %, in Gruppe MM um maximal 20 % auf etwa 48 %, im weiteren Verlauf verweilt sie annähernd auf diesem Niveau. Zerebraler Oxy- und Desoxyhämoglobingehalt verhalten sich entsprechend. Der zerebrale Gesamthämoglobingehalt zeigt keine Gruppenunterschiede. Nach Antagonisierung erfolgt eine Änderung auf die Ausgangswerte vor Narkose ebenso prompt. Narkoseeinleitung und Antagonisierung haben keinen Effekt auf den Redoxzustand von Cytochrom a/a3. Korrelationen der zerebralen Oxygenierung mit arteriellem Sauerstoffstatus und Kohlendioxidpartialdruck bestehen. Eine periodische Atmung und eine Erhöhung des intraabdominellen Drucks spiegeln sich in parallelen Schwankungen der NIRS-Parameter wider. Die Auswirkungen von wechselnder Narkosetiefe, Erwachen, Hypoxie, Hyperventilation, Adrenalin, Pentobarbital, Herz-Kreislauf-Stillstand auf die NIRS-Parameter können dargestellt werden. Bewegungsartefakte stören häufig die Überwachung von Intensivpatienten. Bei Hunden mit Schädel-Hirn-Trauma ist die Signalqualität der limitierende Faktor. Diskussion. Die Nutzung eines für die Anwendung am Menschen bestimmten Gerätes bedingt aufgrund des spezifischen Weglängenfaktors einen Fehler unbekannter Bedeutung. Die zerebrale Messung konnte gesichert werden, der mögliche extrazerebrale Signalanteil bleibt unbekannt. Die nicht mögliche Nutzung bei schwarzen Tieren und die Artefaktanfälligkeit schränken den Wert der NIRS ein. Die ermittelten Störindizes sind stark methodisch beeinflusst, so dass ihre Beurteilung kritisch erfolgen sollte. Die NIRS ist geeignet, die durch Narkoseeinleitung und Antagonisierung beim Hund verursachten Veränderungen der zerebralen Oxygenierung aufzuzeigen. Eine Abnahme der regionalen zerebralen Sauerstoffsättigung um etwa 20 % (Gruppe MM) über die gesamte Messdauer scheint von klinischer Relevanz. Werte in dieser Höhe werden als Indiz einer kritischen zerebralen Sauerstoffversorgung beurteilt. Parallele Verläufe, positive Zusammenhänge mit dem arteriellen Sauerstoffstatus und negative zum Kohlendioxidpartialdruck zeigen ebenso wie die Effekte der Antagonisierung den entscheidenden Einfluss der Anästhetikabedingten Atemdepression auf den vaskulären zerebralen Sauerstoffstatus. Die mangelnde Reduktion von Cytochrom a/a3 deutet auf das Fehlen einer Störung der intrazellulären Sauerstoffversorgung hin. Die Reaktion der NIRS-Parameter auf eine Narkosekomplikation erfolgt schnell, jedoch unspezifisch, eine Interpretation ist nur in Zusammenhang mit anderen Parametern möglich. Die Beurteilung des Redoxzustandes von Cytochrom a/a3 erscheint schwierig, messtechnische Probleme sind nicht ausgeschlossen. Trotz aller messtechnischen und anwendungsbedingten Probleme wird die NIRS als Bereicherung der Überwachungsmöglichkeiten bei Hund und, sehr eingeschränkt, auch bei der Katze beurteilt. Sie eröffnet erstmals die Möglichkeit, die Auswirkungen von in der klinischen Routine eingeführten Verfahren auf die zerebrale Oxygenierung darzustellen. / ON NEAR-INFRARED-SPECTROSCOPY IN DOG AND CAT - EXPERIMENTAL AND CLINICAL STUDY ON PERIOPERATIVE MONITORING AS WELL AS EFFECTS OF ANAESTHESIA ON CEREBRAL OXYGEN STATUS Alef, Michaele Department of Small Animal Medicine, Faculty of Veterinary Medicine, University of Leipzig Habilitation thesis, 4. Dezember 2002 Near-Infrared-spectroscopy (NIRS) is a method to determine continuously and non-invasively the content of oxy- and deoxyhemoglobin as well as the redox status of cytochrome a/a3 in tissue via absorption changes of near-infrared light. Variations in cerebral content of oxy- and deoxyhemoglobin and parameters derived thereof reflect above all the venous oxygen status of the brain and may thus serve as an early and sensitive indicator of cerebral hypoxia. The redox status of cytochrome a/a3 correlates with the cerebral energy status and may thus serve as an indicator of a critical oxygen deficit. Aim of the study. The study was aimed at assessing in dogs and cats the suitability of NIRS and of an equipment used in human medicine for monitoring the cerebral oxygen status during anaesthesia and intensive therapy. The quality of the measurements, technical problems and the achievable results should be critically checked in experimental and clinical situations. Changes of cerebral oxygenation and of the redox status of cytochrome a/a3 with different established protocols of anaesthesia in dogs and after antagonising had to be investigated in the experimental study as well as well as relationships between parameters obtainable with NIRS and those of pulmonary gas exchange and cardiovascular function. Materials and methods. During the clinical study data from 33 dogs and 4 cats were recorded during anaesthesia and intensive supervision. The experimental investigations were performed with 84 foxhounds and 32 Beagles with a mean age of 12,96 months (STD 13,42; range 6,33–94,43) and a mean weight of 24.76 kg (STD 6.6, range 12.7–43), which were distributed at random into four experimental groups. Sensors were applied near the ear base on shaved skin. Experimental groups and design. Group Acepromazine/l-Methadone(AM): INduction 0.1 mg/kg BW Acepromazine and 0.5 mg/kg BW l-Methadonr i.v., no additional maintenance Group Diazepam/l-Methadone(DM): 0.5 mg/kg BW Diazepam and 0.5 mg/kg BW l-Methadone i.v., no additional maintenance Group Medetomidine/l-Methadone(MM): 40 mikrog/kg BW Medetomidine and 0.5 mg/kg BW l-Methadone i.v., no additional maintenance Group Propofol(P): Induction 0.1 mg/kg BW Propofol i.v., Maintenance 0.3 mg/kg/min Propofol i.v. In groups AM, DM und MM antagonization of the opioide with 8 mikrog/kg BW Naloxone i.v. 30 min after induction, in group MM 200 mikrog/kg BE Atipamezole i.v. 5 min later Continuos Monitoring of heart rate, ECG, temperature, invasive blood pressure,pulse oxymetry, near-infrared-spectroscopy. Blood gas analysis 0, 5, 10, 15, 20, 25, 30 min post induction and 0, 2, 7 min post Naloxone/end of infusion. Results. NIRS is in principle applicable in dogs and cats but not, however, in black-haired animals. The main problems are the application of the sensor, movement artefacts and poor quality of the measurement signals. In the experimental study good measurement quality could be obtained in on average 80% of the investigation time, 14% of the recordings are without disturbance, in 17% disturbances are recorded in more than 50% of the investigation time. Before the start of anaesthesia the regional cerebral oxygen saturation amounts to about 65% (n=109, STD 7%). Already one minute after the beginning of anaesthesia significant differences between groups are found: In group P the regional cerebral oxygen saturation increases by about 8% while it decreases in group AM by 5%, in group DM by up to 10% and in group MM by maximally 20% to a value of about 48% where it remains roughly during the following time. Cerebral oxy- and deoxyhemoglobin content display an analogous behaviour. There are no inter-group differences in total cerebral hemoglobin content. After antagonising the initial values before the start of anaesthesia are rapidly attained again. Start of anaesthesia and antagonising do not show any influences on the redox status of cytochrome a/a3 while there are correlations between the cerebral oxygenation and the arterial oxygen status and the partial pressure of carbon dioxide. Periodic breathing and an increase of the intra-abdominal pressure are mirrored by variations of the NIRS-parameters, The effects of changing depth of anaesthesia, waking up, hypoxia, hyperventilation, adrenaline, pentobarbital and circulatory arrest can be demonstrated by the NIRS-parameters. Movement artefacts frequently interfere with the monitoring of intensive patients. The signal quality is frequently not sufficient in dogs with severe head trauma. Discussion. The direct application of factors established in humans leads to poorly defined errors. For cerebral measurements the applicability of the method could be confirmed, the possible contribution of extracerebral signals, however, remains unknown. The fact that black-haired animals cannot be investigated and proneness to artefacts limit the value of NIRS. Determined disturbance indices depend strongly on the methods used and should be seen critically. NIRS is suitable to give an indication of changes of cerebral oxygenation caused by the start of anaesthesia and antagonising. A decrease of about 20% in the regional cerebral oxygen saturation during the total measurement time (group MM) appears to be of clinical relevance. Values in this range are taken to be indicative of a critical cerebral oxygen supply. Parallelisms and positive correlations with the arterial oxygen status as well as negative correlations with carbon dioxide partial pressure and the effects of antagonising demonstrate the decisive influence of anaesthesia-related depression of breathing on the vascular cerebral oxygen status. The lack of cytochrome a/a3 reduction indicates that the intracellular oxygen supply is not disturbed. The reaction of NIRS-parameters on the start of anaesthesia is fast, but unspecific, and a meaningful interpretation is only possible in conjunction with other parameters. The evaluation of cytochrome a/a3 redox status appears to be difficult, and technical problems with the measurement cannot be excluded. In spite of these limitations in terms of measurements and applicability NIRS can be judged as a valuable addition for the clinical observation of dogs, less so with cats. The method opens for the first time the possibility to monitor the influence of clinical routines on cerebral oxygenation.

This dissertation describes the advantages and feasibility of newly synthesized near-infrared (NIR) bis-heptamethine cyanine (BHmC) dyes for non-covalent labeling schemes. The NIR BHmCs were synthesized for biomolecule assay. The advantages of NIR BHmCs for biomolecule labeling and the instrumental advantages of the near-infrared region are also demonstrated. Chapter 1 introduces the theory and applications of dye chemistry. For bioanalysis, this chapter presents covalent and non-covalent labeling. The covalent labeling depends on the functionality of amino acids and the non-covalent labeling relies on the binding site of a protein. Due to the complicated binding process in non-covalent labeling, this chapter also discusses the binding equilibria in spectroscopic and chromatographic analyses. Chapter 2 and 3 evaluate the novel BHmCs for non-covalent labeling with human serum albumin (HSA) and report the influence of micro-environment on BHmCs. The interesting character of BHmCs in aqueous solutions is that the dyes exhibit non- or low-fluorescence compared to their monomer counterpart, RK780. It is due to their H-type closed clam-shell form in the solutions. The addition of HSA or organic solvents opens up the clam-shell form and enhances fluorescence. The binding equilibria are also examed. Chapter 4 provides a brief introduction that summaries the use of capillary electrophoresis (CE), and offers a detailed instrumentation that discusses the importance and advantage of a detector in NIR region for CE separation. Chapter 5 focuses on the use of NIR cyanine dyes with capillary electrcophoresis with near-infrared laser induce fluorescence (CE-NIR-LIF) detection. The NIR dyes with different functional groups show that RK780 is a suitable NIR dye for HSA labeling. The use of BHmCs with CE-NIR-LIF reduces signal noises that are commonly caused by the interaction between NIR cyanine dyes and negatively charged capillary wall. In addition, bovine carbonic anhydrase II (BCA II) is applied to study the influence of hydrophobicity on non-covalent labeling. Finally, chapter 6 presents the conformational dependency of BHmCs on the mobility in capillary and evaluates the further possibility of BHmCs for small molecule detection. Acridine orange (AO) is used as a sample and it breaks up the aggregate and enhances fluorescence. The inserted AO into BHmC changes the mobility in capillary, owing to the conformational changes by AO.

No description available.

De tout temps, les humains ont cherché différents moyens pour améliorer leur quotidien. Avec les avancées technologiques actuelles, cette quête s’en trouve facilitée, notamment dans la volonté d’accroître leurs capacités cognitives et/ou motrices. La neuro imagerie permet dorénavant de renseigner les aires cérébrales activées lors de différentes tâches fonctionnelles. Il est aussi possible de moduler l’activité cérébrale en stimulant localement le cerveau avec de faibles courants électriques. Une des techniques les plus répandues à cet effet est appelée tDCS pour transcranial direct current stimulation. Il s’agit en fonction de la polarité du courant induit de moduler à la hausse (stimulation anodale) ou à la baisse (stimulation cathodale) l’excitabilité cortico-spinale en dépolarisant ou en hyperpolarisant la membrane des neurones, respectivement. Malgré une démocratisation grandissante de la neuromodulation via tDCS, les résultats rapportés par la communauté scientifique sont relativement hétérogènes. Les travaux initiés au début des années 2000 sont remis en cause par des résultats actuels faisant état d’une variabilité inter et intra individuelle assez importante. Cette pierre d’achoppement nécessite de développer de nouveaux protocoles d’application de la tDCS. Dans cette thèse, nous avons étudié plusieurs modalités d’application de la tDCS afin d’accroître la persistance des effets neuroplastiques induits et d’augmenter les performances comportementales. Deux études ont été menées afin de révéler dans un premier temps les apports induits par le couplage tâche motrice-tDCS pour ensuite mettre en avant les effets cumulatifs de la répétition de sessions de tâche motrice-tDCS avec pré conditionnement sur la performance motrice. La première étude à travers l’utilisation de la spectroscopie dans le proche infrarouge a permis de rapporter des changements hémodynamiques distincts subséquents au couplage tâche motrice-tDCS par rapport à des protocoles tDCS plus conventionnels. La primauté de l’utilisation concomitante de la tDCS à la tâche motrice a été révélée par la moindre activation du cortex sensorimoteur durant la stimulation ainsi que par une activation cérébrale retardée accrue qui pourrait représenter une réorganisation neuroplastique. La seconde étude s’est intéressée aux effets de la polarité du conditionnement lors de sessions répétées avec comme objectif d’améliorer l’apprentissage et la rétention du système sensorimoteur. Le conditionnement par tDCS était plus propice lors de sessions répétées à engendrer des performances motrices supérieures contrairement à la condition sham. La polarité cathodale engendrait une persistance prolongée. Les premiers résultats de ces travaux de thèse ont permis de défendre l’usage concomitant de la tDCS avec la tâche motrice. De futures recherches sont nécessaires afin d’étudier le transfert de ces résultats dans le monde de l’entraînement ainsi que celui de la réhabilitation. / Historically, humans have sought various ways to improve their daily lives. With the current technological advances, this quest is facilitated, especially in the desire to increase their cognitive and / or motor skills. Neuro imagery now makes it possible to inform the areas activated during different functional tasks. Today, it is now possible to modulate brain activity by stimulating the brain locally with weak electrical currents. One of the most common techniques for this purpose is called tDCS for transcranial direct current stimulation. The polarity of the induced current (anodal or cathodal stimulation) allows to modulate upward or downward cortico-spinal excitability by depolarizing or hyperpolarizing the membrane of the neurons, respectively. Despite a growing interest of neuromodulation techniques via tDCS, the results reported by the scientific community are relatively heterogeneous. The work initiated at the beginning of the 2000s is called into question by current results showing a rather large inter and intra variability. This stumbling block requires the development of new protocols for the application of anodal tDCS (atDCS). In this thesis, we were interested in optimizing atDCS protocols in order to increase the persistence of the induced-neuroplastic effects and to increase the behavioral performances. Two studies were carried out in order to first reveal the impact from the motor task/atDCS coupling and then to highlight the cumulative effects of multiple motor-tDCS task sessions with priming atDCS on motor performance. The first study through the use of near infrared spectroscopy allowed to report various hemodynamic changes subsequent to the motor task/atDCS coupling with respect to independent and controlled stimulation protocols. The primacy of the concomitant use of tDCS with the motor task was revealed by the slightest activation of the sensorimotor cortex during stimulation and by an increased delayed cerebral activation which could represent a neuroplastic reorganization. The second study examined the effects of repeated atDCS sessions with anoadal or cathodal tDCS priming in order to improve the learning and retention gains of the sensorimotor system. TDCS priming was more favorable for repeated atDCS sessions to generate higher motor performances contrary to sham. The cathodal polarity produced prolonged persistence. The major findings of this work allow to support the concomitant use of atDCS with the motor task. Future research is needed to study the transfer of these results into the fields of coaching and rehabilitation.

Submitted by Maurilio Gustavo Nespeca (mauriliogn@hotmail.com) on 2018-08-31T21:01:07Z No. of bitstreams: 1 TESE - MAURILIO G NESPECA.pdf: 12338235 bytes, checksum: 0ffb2ce70bfeb2d88ea11b6f84d923e9 (MD5) / Approved for entry into archive by Ana Carolina Gonçalves Bet null (abet@iq.unesp.br) on 2018-09-04T12:54:22Z (GMT) No. of bitstreams: 1 nespeca_mg_dr_araiq_int.pdf: 8911620 bytes, checksum: d6033930d5b3d08e08ac463efd5ad737 (MD5) / Made available in DSpace on 2018-09-04T12:54:22Z (GMT). No. of bitstreams: 1 nespeca_mg_dr_araiq_int.pdf: 8911620 bytes, checksum: d6033930d5b3d08e08ac463efd5ad737 (MD5) Previous issue date: 2018-08-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Segundo dados, de 2017, da Companhia Ambiental do Estado de São Paulo (CETESB), os postos de combustíveis são responsáveis pela contaminação ambiental de 72% das 5942 áreas contaminadas cadastradas no estado de São Paulo. A contaminação de solos e águas subterrâneas por combustíveis fósseis causam imensos danos ambientais devido à alta toxicidade dos constituintes destes combustíveis, além de apresentarem propriedades carcinogênicas e elevada permanência no solo. O monitoramento ambiental em áreas de risco potencial de contaminação, como postos de combustíveis, é realizado através da análise de hidrocarbonetos totais do petróleo (TPH), entre outros hidrocarbonetos individuais. Estas análises são realizadas através de métodos cromatográficos em fase gasosa que requerem etapas de extração com solventes halogenados, purificação e, muitas vezes, pré-concentração. O elevado custo e o tempo demandado para a quantificação de TPH em solo tornam-se barreiras para o crescimento do monitoramento e acompanhamento de processos de remediação das áreas contaminadas. Desta forma, este trabalho objetivou o desenvolvimento de métodos analíticos mais rápidos e de menor custo para a identificação e quantificação de TPH em solo através da espectroscopia na região do infravermelho próximo (NIR). Três métodos NIR foram desenvolvidos: (i) sem preparo de amostra; (ii) após extração por hexano; e (iii) após extração por etanol. Os modelos de classificação foram desenvolvidos pelo método de análise discriminante por mínimos quadrados parciais (PLS-DA) e os modelos de calibração por mínimos quadrados parciais (PLS). No desenvolvimento dos modelos, nove diferentes pré-processamentos e seleção de variáveis pelo algoritmo genético (GA) foram avaliados. Os modelos foram desenvolvidos usando-se amostras de solo fortificado com os contaminantes (gasolina, diesel e óleo lubrificantes) e validados com amostras de solo contaminado, adquiridas no monitoramento ambiental de postos de combustíveis. O modelo PLS-DA proporcionou 100% de classificações corretas das amostras contaminadas sem a necessidade de preparo de amostra, enquanto a predição da concentração dos analitos tornou-se possível através dos modelos PLS após a etapa de extração com etanol. Como objetivos secundários deste trabalho, foram desenvolvidos métodos de quantificação das diferentes frações de TPH e dos compostos benzeno, tolueno, etilbenzeno e xilenos (BTEX) por cromatografia em fase gasosa ultrarrápida com detector de ionização por chama (UFGC-FID). Além do desenvolvimento dos métodos UFGC-FID, otimizou-se o processo de extração dos analitos por sonicação através de planejamentos experimentais, avaliando-se diferentes solventes, tempo de sonicação, agitação por vórtex e volume de solvente. Os métodos UFGC-FID proporcionaram análises de 3 a 17 vezes mais rápidas que o método cromatográfico de acordo com a norma EPA 8015. Ao final deste trabalho, os métodos desenvolvidos e o método EPA 8015 foram comparados segundo aspectos analíticos, ambientais e financeiros. De forma geral, os três métodos apresentaram mesma exatidão; o método cromatográfico (EPA 8015) foi o método mais preciso; o método UFGC-FID foi o de menor investimento inicial e de menor tempo para retorno financeiro; e, finalmente, o método NIR após extração com etanol foi o mais sensível, rápido, favorável à química verde e de menor custo por análise. / According to the Environmental Company of the State of São Paulo (CETESB), the gas stations are responsible for the environmental contamination of 72% of the 5942 contaminated areas registered in the state of São Paulo. Contamination of soils and groundwater by fossil fuels causes immense environmental damages due to their high toxicity, carcinogenic properties and high permanence in the soil. Environmental monitoring in areas of potential contamination risk, such as gas stations, is carried out through the analysis of total petroleum hydrocarbons (TPH), among other individual compounds. These analyzes are performed by gas chromatographic methods which require some sample preparation steps, such as extraction with halogenated solvents, purification, and often preconcentration. The high cost and time demanded for the quantification of TPH in the soil become barriers for the growth of the monitoring program and remediation processes of the contaminated areas. Therefore, this work aimed at the development of faster and lower cost analytical methods for the identification and quantification of TPH in soil through near-infrared spectroscopy (NIR). Three NIR methods were developed: (i) without sample preparation; (ii) after hexane extraction; and (iii) after extraction with ethanol. The classification models were developed by partial least squares discriminant analysis (PLS-DA) method and the calibration models by partial least squares (PLS) method. In the development of the models, we evaluated nine different preprocessing and selection of variables by the genetic algorithm (GA). The models were developed using soil samples fortified with contaminants (gasoline, diesel and lubricant oil) and validated with samples of contaminated soil acquired in the environmental monitoring of gas stations. The PLS-DA model provided 100% correct classifications without sample preparation, while the prediction of the concentration of the analytes was possible by PLS models after the ethanol extraction. As secondary objectives of this work, we developed quantification methods for the different fractions of TPH and benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds by ultrafast gas chromatography with flame ionization detector (UFGC-FID). In addition to the UFGC-FID methods, the TPH extraction by sonication was optimized through experimental design, evaluating different solvents, sonication time, agitation and solvent volume. The UFGC-FID methods provided analyzes 3 to 17 times faster than the chromatographic method according to EPA 8015. At the end of this work, the developed methods and the EPA 8015 method were compared according to analytical, environmental and financial aspects. In general, the three methods presented the same accuracy; the EPA 8015 method was the most precise; the UFGC-FID method presented lower initial investment and less time for financial return; and the NIR method after ethanol extraction was the most sensitive, fast, favorable to green chemistry and presented the lowest cost per analysis.

Le centre de la Galaxie abrite un trou noir supermassif, Sagittarius A*. Sa proximité en fait un laboratoire privilégié pour étudier les phénomènes d’accrétion à l’œuvre autour des trous noirs et contraindre le cycle d’activité de ces astres. Sgr A* est actuellement extrêmement peu lumineux et malgré des sursauts d’activité quotidiens sa luminosité demeure au moins huit ordres de grandeur en dessous de sa luminosité d’Eddington. Cet objet est ainsi l’un des trous noirs supermassifs connus les moins lumineux. Les mécanismes radiatifs à l’origine des variations quotidiennes observées ne sont pas clairement identifiés. Nous présentons les résultats d’une campagne d’observation multi-longueurs d’onde visant à mesurer le spectre de ces événements simultanément en rayons X et en infrarouge proche, à l’aide de l’observatoire XMM-Newton et de l’instrument VLT/NACO. Les données infrarouges obtenues grâce à la technique de spectro-imagerie en bande large ont permis d’étudier la variabilité du spectre de Sgr A* en infrarouge. Les incertitudes liées aux erreurs systématiques sont encore importantes mais les premiers tests réalisés semblent indiquer que l’indice spectral pourrait dépendre de la luminosité du trou noir. Sur des échelles de temps plus grandes, nous montrons également que Sgr A* n’a pas toujours été aussi peu actif. Des traces de son activité passée sont en effet visibles dans la matière moléculaire directement autour du trou noir, notamment sous la forme d’un rayonnement réfléchi visible dans la raie de fluorescence du fer à 6.4 keV. Nous avons réalisé une étude complète et systématique des variations de cette émission détectée dans la zone moléculaire centrale en utilisant les observatoires Chandra et XMM-Newton. Nos résultats confirment que Sgr A* a connu des sursauts intenses au cours des derniers siècles, au moins six ordre de grandeur en dessus de la luminosité actuelle. En particulier, nous avons mis en évidence, pour la première fois, la présence de deux événements transitoires distincts de relativement courte durée, probablement liés à des événements catastrophiques. Ces résultats constituent une première étape pour relier l’activité de ce trou noir spécifique aux autres noyaux de galaxie présents dans l’Univers. / Sagittarius A⋆ is the supermassive black hole at the Galactic center. Due to its proximity, this specimen is an excellent laboratory to study the accretion processes occurring around black holes and to constrain the duty cycle of these objects. Sgr A* is currently extremely faint and despite the detection of daily flares, its luminosity remains at least eight orders of magnitude below its Eddington luminosity, making this specimen one of the least luminous known supermassive black holes. The radiative processes responsible for the daily variations of its luminosity have not been clearly identified yet. We present the results of a multi-wavelength campaign observing Sgr A* simultaneously in X-rays and in the near-infrared, using the XMM-Newton observatory and the VLT/NACO instrument. We studied the spectral variability of Sgr A* using the infrared data we obtained through a spectro-imaging technique. Uncertainties linked to the systematic errors are still large but the first tests applied seem to show that the spectral index of Sgr A* could depend on the black hole luminosity. On longer timescales, we demonstrate that Sgr A* experienced a higher level of activity in the recent past. Indeed, echoes of its past activity can be detected in the molecular material surrounding the black hole. They are traced by a strong signal in the iron fluorescence line at 6.4 keV. We achieved a complete and systematic study of this variable emission detected from the central molecular zone, using Chandra and XMM-Newton observatories. Our results confirm that Sgr A* experienced intense flares in the past few centuries, with a luminosity at least six orders of magnitude higher than its current one. In particular, we highlight for the first time the existence of two distinct transient events of relatively short duration, which are probably due to catastrophic events. These results are the first step needed to include Sgr A*’s activity into a broader understanding of the galactic nuclei.

Made available in DSpace on 2015-07-22T20:49:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-10-28 / Ha evidencias de que o fluxo microvascular de oxigenio (QO2mv) limita a taxa de aumento da captacao de oxigenio ( O2) no inicio do exercicio intenso em pacientes com doenca pulmonar obstrutiva cronica (DPOC). Entretanto, ainda nao esta claro se a suplementacao de O2 poderia acelerar a cinetica do O2 atraves da melhora do QO2mv em pacientes nao-hipoxemicos ou levemente hipoxemicos. Assim, o objetivo do estudo foi investigar se a suplementacao aguda de O2 (HiOX=50%O2) poderia alterar a dinamica entre oferta e O2 microvascular na transicao do exercicio leve para o intenso, alem de avaliar se os possiveis efeitos da HiOX na oxigenacao tecidual tissular teriam efeito modulador na cinetica da utilizacao muscular de O2. Para tal, foram avaliados 19 pacientes do sexo masculino, nao-hipoxemicos ou levemente hipoxemicos (PaO2>60mmHg) portadores de DPOC de gravidade moderada a acentuada (VEF1/CVF < 0,7 e VEF1 entre 30 e 60% do previsto) e estaveis clinicamente, durante exercicio submaximo de alta intensidade (80% da maxima atingida no exercicio incremental em cicloergometro). Neste contexto, foram investigados os efeitos da HiOX em comparacao com normoxia (NOX = 21% O2) na cinetica do O2 mensurado em nivel pulmonar (p) e da extracao fracional de O2 (HHb mensurada pela espectroscopia por raios quase infravermelhos - NIRS) no vasto lateral. A HiOX esteve associada com aumento na tolerancia ao exercicio (p<0,05) alem de reducao da concentracao de lactato, sensacao de dispneia e desconforto muscular corrigidos para o tempo de duracao do exercicio (Tlim) (N=19). Nos 11 individuos com sinais adequados para estudo da cinetica, a extracao fracional de O2 estimada acelerou-se (DHHb: t= 4.8 } 2.4 s vs. 6.7 } 3.0 s; P<0.05) e um subsequente fenomeno de govershoot h foi observado em 7/11 pacientes, sugerindo prejuizo no QO2mv. Entretanto, durante o periodo estado-estavel, houve reducao dos valores de HHb em 9/11 pacientes sugerindo melhora do QO2mv. Como consequencia desse efeito dual da HiOX no QO2mv (i.e, reducao seguida de melhora), a cinetica do O2p foi acelerada em 6 pacientes mas lentificada em outros 5 pacientes. De forma interessante, observamos que pacientes que apresentaram aceleracao da cinetica do O2p com HiOX tambem apresentaram maiores reducoes dos valores de DHHb no estado-estavel comparados aos demais pacientes (HiOX . NOX= -23.4 (-55.5 to -5.8) ƒÊM/cm vs. -0.62 (-22.6 to 10.7) ƒÊM/cm; p<0.05). Adicionalmente, houve correlacao significativa entre reducao dos valores de DHHb no estado-estavel e aceleracao na cinética do O2 com HiOX (R= 0.61; p<0.05). Em conclusão, HiOX melhorou a tolerância ao exercício físico, além de ter resultado em redução significativa da dispnéia, percepção de fadiga periférica e lactato corrigidos pelo tempo de exercício em pacientes com DPOC não-hipoxêmicos ou levemente hipoxêmicos. Entretanto, nosso resultados indicam que houve prejuízo transitório no QO2mv no início do exercício, que foi compensado por melhora subseqüente, justificando assim os efeitos heterogêneos do O2 na cinética do O2p. Portanto, as consequências da HiOX na taxa de aumento do metabolismo oxidativo no início do exercício intenso nessa sub-população de pacientes parece depender de um complexo balanço entre os efeitos negativos iniciais no fluxo sanguíneo microvascular e as posteriores conseqüências positivas nos determinantes difusivos e/ou convectivos do transporte capilar-muscular de O2. / There is convincing evidence that impaired microvascular O2 delivery (Q LO2mv) to the peripheral muscles limits the rate of increase in pulmonary O2 uptake ( O2p) at the onset of supra-gas exchange threshold exercise in patients with chronic obstructive pulmonary disease (COPD). It is currently unclear, however, whether O2 supplementation could actually improve Q LO2mv thereby accelerating O2p kinetics in patients who are not overtly hypoxemic (PaO2 > 60 mmHg). We therefore investigated the effects of hyperoxia (HiOX= 50% O2) and normoxia (NOX) on the kinetics of O2p and fractional O2 extraction in the vastus lateralis ( [deoxy- Hb+Mb] by near-infrared spectroscopy) in 11 non- or mildly-hypoxemic patients. HiOX increased exercise tolerance compared to NOX (P<0.05). At the on-exercise transient, however, HiOX was associated with faster [deoxy-Hb+Mb] kinetics (= 4.8 } 2.4 s vs. 6.7 } 3.0 s; P<0.05) and a response govershoot h in 7/11 patients suggesting impaired Q LO2mv. Subsequently, however, [deoxy-Hb+Mb] decreased to lower steady-state values compared to NOX in 9/11 patients (P<0.05). As a likely consequence of these opposite effects of HiOX on Q LO2mv (i.e., early impairment followed by later improvement), O2p kinetics were accelerated in 6 but slowed in 5 patients. Interestingly, patients in whom HiOX accelerated O2p kinetics showed consistently-larger reductions in gsteady-state h ..[deoxy-Hb+Mb] compared to their counterparts (HiOX . NOX= -23.4 (-55.5 to -5.8) ƒÊM/cm vs. -0.62 (-22.6 to 10.7) ƒÊM/cm; p<0.05). In conclusion, HiOX can transitorily impair the convective flow of O2 to the working peripheral muscles at the onset of heavy intensity exercise in patients with COPD who are not overtly hypoxemic. This effect, however, might be (over)compensated by a subsequent increase in local O2 availability in selected patients. These data seem to provide a mechanistic explanation for the heterogeneous effects of HiOX on O2p kinetics in this patient sub-population. / TEDE / BV UNIFESP: Teses e dissertações

Ce travail porte sur la conception, la fabrication et la caractérisation de lentilles planaires nano-structurées dédiées aux capteurs d’images CMOS dans le proche-infrarouge. L’étude des applications et des systèmes d’imagerie optronique mis en jeu ont mis en évidence l’intérêt de l’utilisation des capteurs d’images CMOS dans la bande 800-1100 nm. Les inconvénients liés au silicium et à la structure du pixel justifient l’intégration de lentilles planaires nano-structurées compatibles avec le procédé de fabrication CMOS : une lentille plasmonique, une lentille diffractive métallique dite de Huygens, une lentille diélectrique dite de phase de Fresnel et une lentille à gradient d’indice effectif. Les simulationsélectromagnétiques 2D d’un pixel CMOS complet avec chaque lentille planaire ont démontré l’intérêt de la lentille métallique dans un pixel à faible facteur de remplissage et de la lentille de phase de Fresnel pour un pixel standard. Les simulations électromagnétiques 3D ont permis la conception de ces deux dernières lentilles pour leur fabrication tandis que la lentille à gradient d’indice effectif, susceptible d’approcher le profil de phase idéal, a montré son potentiel pour les pixels CMOS. La caractérisation électro-optique a mis en évidence la performance expérimentale de la lentille de phase de Fresnel fabriquée en "post-process" au LPN-CNRS et de la lentille de Huygens fabriquée "in-process" en fonderie CMOS. Les nombreuses perspectives de ce travail liés à la fabrication et à la marge de progression des lentilles ont été explorées. / This work deals with the design, fabrication and characterization of nanostructuredplanar lenses dedicated to near infrared detection for CMOS image sensors.Applications and optronic systems involved in near infrared imaging have been investigatedin order to highlight the strong interest of CMOS images sensors for the 800-1100 nmspectral band. Limitations of silicon and pixel structure explain the integration of nanostructuredplanar lenses compatible with CMOS fabrication process : a plasmonic lens, a dielectricphase-Fresnel lens, a metallic Huygens lens and a gradient-index lens. 2D electromagneticsimulations of a CMOS pixel with each planar lens have demonstrated the good performanceof the Huygens lens for low fill factor pixels and the phase-Fresnel lens for standard pixels.3D simulations of these lenses have been performed for their integration and fabrication inCMOS image sensors. The 3D design by numerical simulations of a gradient-index lens hasshown its potential interest for CMOS pixels. The experimental performance of a dielectriclens "post-process" integrated/fabricated at LPN-CNRS and a metallic lens "in-process" by aCMOS foundy have been evaluated by electro-optical characterization. Several perspectivesof this work about lens fabrication and potential for improvement have been explored.

Orientador: Prof. Dr. João Ricardo Sato / The brain is a complex system organized in structurally segregated and functionally specialized regions. The brain areas are composed of neuronal networks interconnected by axonal pathways that integrate through correlated neural activity. Recent studies on neural connectivity using graph theoretical analysis have revealed that brain networks interact through densely connected regions with high topological value called hubs. Previous studies of Default Mode Network (DMN), one of the most important resting-state networks, have improved the understanding of the intrinsic neuronal activity and the dynamics of the human brain. Spontaneous brain activity and Resting-State Functional Connectivity (RSFC) patterns of Resting-State Network (RSN) are essential for the comprehension of the brain function. Neuroimaging techniques such as functional Near Infrared Spectroscopy (fNIRS) make these studies possible. Thus, the main objective of this study was to investigate the RSFC using Eigenvector Centrality (EVC) measure of graph theory in fNIRS data. This work has demonstrated the effectiveness of the graph analysis for detection of hubs and mcommunities, and identified brain regions associated with rich-club, that integrates highly interconnected hubs and plays a central role in the flow and integration of Information throughout the brain. One can also conclude from the RSFC analysis the existence of functional hubs associated with DMN. / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia da Informação, 2017. / O cérebro é um sistema complexo organizado em regiões segregadas estruturalmente e especializadas funcionalmente que são compostas por redes neuronais interconectadas por vias axonais que se integram através de atividade neural correlacionada. Estudos recentes sobre conectividade neural usando teoria de grafos revelaram que as redes cerebrais interagem através de regiões densamente conectadas e com alto valor topológico denominadas hubs. Dentre as redes existentes destaca-se, por sua contribuição para a melhor compreensão do funcionamento do cérebro humano, a rede de modo padrão (Default Mode Network, DMN). A atividade espontânea do cérebro e os padrões de conectividade funcional (Resting-State Functional Connectivity, RSFC) das redes cerebrais na condição de repouso (Resting-State Network, RSN) também se tornam essenciais nos estudos que visam compreender a função desse órgão, estudos esses possibilitados graças às técnicas de neuroimagem destacando-se a espectroscopia funcional no infravermelho próximo (functional Near Infrared Spectroscopy, fNIRS). Assim, o objetivo principal deste estudo foi investigar a RSFC usando a medida de centralidade do autovetor (Eigenvector Centrality, EVC), técnica pertencente à teoria de grafos, em dados de fNIRS. Este estudo pode demonstrar a eficácia da metodologia empregada para analisar a RSFC além de revelar a existência de um núcleo estrutural, denominado hub complex, densamente conectado (rich-club), que integra hubs altamente interligados e desempenha papel central no fluxo e integração da informação ao longo do cérebro. Pode-se também concluir a partir da análise da RSFC a existência de hubs funcionais associados à DMN.