Dissertations / Theses on the topic 'Iodine and Hydrogen iodide'

A PWC structure has developed for an industrial scale SITC plant. Based on the performance evaluation, it has been shown that the SITC plant developed via the proposed modified SOC structure can produce satisfactory performance – smooth and reliable operation. The SITC plant is capable of achieving a thermal efficiency of 69%, which is the highest attainable value so far. It is worth noting that the proposed SITC design is viable on the grounds of economic and controllability.

Since mankind's adoption of fossil fuels as its primary energy carrier for heating, elec- tricity and transportation, the release of greenhouse gases into the atmosphere has increased constantly . A potential replacement energy carrier is hydrogen. Current industrial techniques for dissociating hydrogen from its common substances are con- ventionally reliant on fossil fuels and thus greenhouse gases are still released. As a mechanism to develop a hydrogen economy current industrial techniques will suffice; however, a long-term sustainable solution to hydrogen mass production that does not release greenhouses gases is desired. The United States of America Government be- lieves that the Sulphur-Iodine thermochemical hydrogen production cycle, thermally powered by a nuclear source, is the most likely long-term solution. A critical part of the Sulphur-Iodine cycle is the point of interaction between the thermal source and sulphuric acid used within the cycle. A novel bayonet heat exchanger made from silicon carbide is theoretically applied to the point of interaction. Through a combination of experiments and theoretical modelling, the bayonet heat exchanger is characterised. The bayonet model is then modified to simulate the intended nuclear reactor favoured by the United States Department of Energy. In addition, the bayo- net heat exchanger is analysed for a solar thermal application. An advanced design of the bayonet is also presented and theoretically analysed for its increased thermal efficiency.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.B.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2006.
Includes bibliographical references (p. 63).
The Sulfur-Iodine Cycle for the thermochemical production of hydrogen offers many benefits to traditional methods of hydrogen production. As opposed to steam methane reforming - the most prevalent method of hydrogen production today - there are no carbon dioxide emissions. Compared to other methods of hydrogen production, the efficiency of the cycle is excellent. Due to the high temperatures necessary for the cycle, which are generally greater than 8500C, several of the Generation IV nuclear reactor concepts are attractive thermal energy sources. However, the high temperature and corrosive reaction conditions of the cycle, involving reactions including the decomposition of H2SO4 at 400-9000C, present formidable corrosion challenges. The conversion of sulfuric acid to sulfur dioxide was the focus of this study. The alloying of structural materials to platinum has been proposed as a solution to this problem. A catalytic loop to test the materials was constructed. Sulfuric acid was pumped over the material at 903+20C. The sulfur dioxide production of the catalyst was measured as a means of quantifying the efficiency of the system as a function of temperature.
(cont.) The maximum possible production of the material was calculated by using a mass balance. A gas chromatograph was used to calculate the actual production of sulfur dioxide. The results of the experiment show that an molecular conversion efficiency of 10% is attained when operating at 900C while using 800H + 5%Pt as a catalyst. The research confirms the catalytic activity of the material.
by Kevin Miu.
S.B.

O processo de reparo em alvéolo infectado de ratos foi avaliado após a utilização de três tipos de tratamento: (1) curetagem e irrigação com soro fisiológico seguida do preenchimento com uma pasta à base de metronidazol a 10%, lidocaína a 2%, menta e carboximetilcelulose, (2) irrigação única com solução de iodeto de sódio a 2% e peróxido de hidrogênio a 3% na proporção 1:1 e (3) irrigação diária, por 3 dias, com solução de iodeto sódio a 2% e peróxido de hidrogênio a 3% na proporção 1:1. Foram utilizados 75 ratos que constituíram os seguintes grupos: Grupo I: alvéolo não infectado (grupo controle positivo); Grupo II: alvéolo infectado sem nenhum tratamento; Grupo III: alvéolo infectado tratado com irrigação única de solução de iodeto de sódio a 2 % e peróxido de hidrogênio a 3% na proporção 1:1; Grupo IV: alvéolo infectado tratado com irrigação diária, por 3 dias, de solução de iodeto de sódio a 2 % e peróxido de hidrogênio a 3% na proporção 1:1; Grupo V: alvéolo infectado submetido à curetagem, irrigação com soro fisiológico e preenchimento com pasta à base de metronidazol a 10% e lidocaína a 2%, carboximetilcelulose e menta. Os animais, em número de 5 em cada grupo foram sacrificados aos 6, 15 e 28 dias após a exodontia do incisivo superior e as peças obtidas analisadas em microscopia óptica. Os resultados foram submetidos à análise qualitativa e quantitativa e evidenciaram melhor reparo nos grupos tratados em relação ao grupo sem tratamento. Com base nos resultados foi possível concluir que: os grupos III, IV e V apresentaram melhores condições de reparo frente ao grupo II, porém diferentes significantemente ao grupo I; o grupo V apresentou os melhores resultados quanto à neoformação óssea nos períodos de 15 e 28 dias, sendo uma opção interessante a ser considerada para o tratamento da alveolite.
The healing process in infected tooth sockets was evaluated after application of three types of treatment.: (1) surgical cleaning of the socket with alveolar curettes, saline solution irrigation and complete filling of the socket with a 10% metronidazole, 2% lidocaine, carboxymethylcelullose and mint as flavoring, (2) Single irrigation with 2% sodium iodide and 3% hydrogen peroxide solution (1:1) and (3) Daily irrigation, for three days, with 2% sodium iodide and 3% hydrogen peroxide solution (1:1). Seventy-five rats were randomly assigned to the following groups: Group I: Non-infected tooth socket (positive control group); Group II: Infected tooth socket without treatment; Group III: Infected tooth socket treated with single irrigation of 2% sodium iodide and 3% hydrogen peroxide solution (1:1); Group IV: Infected tooth socket treated daily, for three days, with irrigation of 2% sodium iodide and 3% hydrogen peroxide solution (1:1); Group V: Infected tooth socket treated with surgical cleaning of the socket with alveolar curettes, saline solution irrigation and complete filling of the socket with a 10% metronidazole, 2% lidocaine, carboxymethylcelullose and mint as flavoring. The rats were killed in number of five at each group after 6, 15 e 28 days of superior incisor extraction. The histological findings were measured by qualitative and quantitative methods. The results demostrated better results of tooth socket healing in treated groups. Based on the results it was possible to conclude that groups III, IV and V exhibited better conditions of alveolar healing, compared to group II, although significant difference was observed with group I. Group V showed the best results in bone formation at 15 and 28 days, consisting in an interesting option for dry socket treatment.

A chemical ionisation mass spectrometer (CIMS) was developed and utilised for measurements onboard the Facility for Atmospheric Airborne Measurements (FAAM) BAe-146 aircraft. The I- ionisation scheme was implemented to detect nitric acid (HNO3), formic acid (HC(O)OH), hydrogen cyanide (HCN) and dinitrogen pentoxide (N2O5) simultaneously at a sampling frequency of 1 Hz. Sensitivities ranged from 35±6 ion counts pptv-1 s-1 for HC(O)OH to 4±0.9 ion counts pptv-1 s-1 for HCN and limits of detection from 37 ppt for HNO3 and 5 ppt for HCN. Trace gas concentrations of species such as HC(O)OH are currently under predicted in global models. In order to understand their role in controlling air quality, it is crucial that their production pathways and abundance are accurately measured and constrained. To date, airborne measurements of these trace gases have been difficult as a result of instrumental limitations on an aircraft such as limit of detection and sampling frequency. The first UK airborne measurements of HC(O)OH and HNO3 confirmed that HC(O)OH is under predicted by up to a factor of 2 in a trajectory model that implements the full Master Chemical Mechanism (MCM) and Common Representative Intermediate Scheme (CRI). The inclusion of a primary vehicle source enabled the model to reproduce the concentrations observed; verifying that direct sources are under represented. Secondary formation of HC(O)OH was observed through its correlation with HNO3 and ozone (O3), indicating a strong photochemical production source. Hydroxyl (OH) concentrations were estimated for the first time in a flight around the UK using the HC(O)OH and HNO3 measurements. A biomass burning (BB) plume identification technique is applied to data obtained from Canadian biomass fires using HCN as a marker. A 6 sigma above background approach to defining a plume resulted in a higher R2 correlating value for the normalised excess mixing ratio (NEMR) to carbon monoxide (CO) when compared to current methods in the literature. The NEMR obtained from this work; 3.76±0.02 pptv ppbv-1, lies within the range found in the literature. This NEMR is then used to calculate a global emission total for HCN of 0.92 Tg (N) yr-1 when incorporated into the global tropospheric model STOCHEM CRI. The first direct N2O5 airborne measurements on an aircraft at night are compared to indirect measurements taken by a broadband cavity enhancement absorption spectrometer. An average R2 correlation coefficient of 0.87 observed over 8 flights for 1 Hz measurements indicates the selectiveness of the I- ionisation scheme to detect N2O5 directly, without nitrate (NO3) interference.

Iodine-129 is a high-yield fission product of 235U and 239Pu; is produced in nuclear power plants and is therefore present in substantial quantities in radioactive wastes. In the environment, iodine exists as a range of species: iodate (IO3-), iodide (I-), elemental iodine (I2), HOI and organic species are the most common. The behaviour of iodine in the environment is linked to its speciation which can be affected by different factors such as pH, redox potential and enzymatic reduction. Previous research has shown that iodine speciation can determine its fate in the environment; however the mechanisms of redox cycling amongst the different species are not yet fully understood. This research project has focused on improving the understanding of the changes on speciation of iodine in sediment and mineral systems undergoing redox cycling reactions. The fate and changes in iodine speciation were studied under reducing and oxidising conditions, with all experiments conducted under circumneutral pH conditions. Overall the results showed that when microbial activity is promoted in a sediment system, iodate is reduced to iodide with the reduction occurring during manganese reduction. Further, when nitrate is present at high concentrations the reduction of iodate is retarded. A net release of native iodine from sediments was observed in all experiments conducted with sediments; confirming previous observations that sediment bound iodine is released from sediments under reducing conditions. Modest abiotic reduction of iodate was observed under manganese and iron reduction; and iodate reduction happened faster in a mixed system with iron and pure culture bacteria than solely by the pure culture alone or via abiotic reduction with Fe(II). When reduced experiments were exposed to air, concentrations of iodide decreased with no iodate ingrowth or losses in total iodine in solution. This suggested that iodide had been oxidised to intermediate species (I2, HOI) that were not detected, although this reaction has been described in past research. Finally, when no microbial activity is promoted, iodine remains as iodate which showed modest sorption onto sediment systems and Fe(III) oxide. Overall, these results highlight the important role that bacteria play in the reduction of iodate. This research also confirms that iodine speciation impacts on the fate of 129I throughout the environment, where it may be less mobile in an oxic environment than under reducing conditions. Moreover, some techniques of bioremediation (e.g. promoting metal reducing conditions) may cause the release of radioactive iodine to solution.

Iodine, a minor constituent in ground water, is valuable as an indicator of subsurface sources of salinity. A review of iodine geochemistry reveals that exceptions to conservative behavior include sorption onto iron and aluminum oxides and incorporation into marine organic matter with additional enrichment due to sorption. Data from the Milk River aquifer in Alberta, Canada indicate that iodide in the ground water is derived from residual waters in the fine grained, marine sediments within the sandstone formation. This localized enrichment of iodide is superimposed on a more general enrichment of halides downgradient from the recharge area, probably due to ion filtration.

Structural studies using the synchrotron based Normal Incidence X-Ray Standing Wave (NIXSW) technique of the copper(III)- √3x√3))R30 grad.-Iodine and copper(111)- √3x√3)R30grad.-1/2(CdI2) surfaces are presented. For the copperiodine system, the iodine was shown to adsorb in a mixture of fcc and hcp hollow sites at a distance of 2.16 ± 0.05A from the copper surface, in a (√3x√3))R30 grad. mesh. The hollow site ratio observed was 50 ± 3 % in fcc sites and 50 ± 3 % in hcp sites. For the copper-cadmium iodide system, the iodine was again shown to adsorb in a mixture of the three fold hollows, at a slightly smaller distance of 2.10 ± 0.05A from the copper surface, again in a (√3x√3)R30 grad. mesh. The ratio of occupation of the hollow sites was determined to be 37 ± 3 % in fcc sites and 63 ± 3 % in hcp sites. The copper(111)-( √3x√3)R30 grad.-Iodine surface produced by annealing the copper(111)- 1/2(CdI2) surface, was shown to have a different ratio again, at 80± 3 % in fcc sites and 20 ± 3 % in hcp sites. Possible explanations for the changing ratios are discussed including sample temperature during surface preparation, step density of the crystal, co-adsorption of adsorbate or contamination and surface coverage. The cadmium in the copper-1/2(CdI2) surface was shown to be adsorbed randomly in a mixture of the three fold hollow sites, at 2.25 ± 0.05A from the copper surface. The ratio was found to be 48 ± 3 % in fcc sites and 52 ± 3 % in hcp sites. Both studies were found to be affected by the presence of non-dipole effects in the angular distribution of the core level photoelectrons used to collect some of the data. This caused incorrect values for the standing wave structural parameters to be determined, A novel experiment was performed using two analyser geometries which enabled the importance of including the non-dipole terms in the standing wave equations to be confinned. An updated version of the standing wave equations is presented which allows quantification of and correction for the non-dipole terms. The surface reactions of iodine and cadmium iodide on an aluminium(111) surface at room temperature are shown to result in etching of the surface and the production of aluminium iodide (A1I3). For both systems, iodine forms a close-packed chemisorbed layer that has a (..J7x-..J7)R19.1° symmetry, with an iodine coverage of 3/7 of a monolayer. For the cadmium iodide surface, the cadmium is proposed as being located randomly above the chemisorbed iodine layer. With the sample liquid nitrogen cooled to low temperatures, iodine produced physisorbed multilayers, and cadmium iodide adsorbs intact, but with no ordered growth. A novel technique, Line Of Sight Sticking Probability (LOSSP), which allows the measurement of sticking and reaction probabilities is presented and applied to the I/Al system. The initial sticking probability for iodine at 300 K was determined as 0.8 ± 0.1. Under steady state etching conditions at 300 K the overall reaction probability for I2 to form AlI3, was, Rss = 0.36 ± 0.07. The surface consisted of a majority of chemisorbed iodine, with a minority of coadsorbed AlI3, with a total iodine coverage of ~ 0.6 ML. The sticking probability of I2, to solid iodine at 103 K was measured as Sphys = 0.98 ± 0.02, while the sticking probability on the halogenated surface at 300 K was measured as ~ys > 0.8 ± 0.1 Variable temperature measurements gave an activation energy for the desorption of All, of approximately 57 kJmol-1.

This project has investigated the removal of iodine species from wastewater using LDH technology. This research focused on initial laboratory scale experiments to assess the suitability of this methodology as a cost effective means of treating water contaminated with radioiodine from industrial and medical wastes.

Thesis (Ed.D.)--Teachers College, Columbia University, 1994.
Includes tables. Typescript; issued also on microfilm. Sponsor: Jean Lythcott. Dissertation Committee: Roger O. Anderson. Includes bibliographical references (leaves 174-186).

Thesis (Ph. D.)--Ohio State University, 2003.
Title from first page of PDF file. Document formatted into pages; contains xiv, 133 p.; also includes graphics Includes bibliographical references (p. 116-133). Available online via OhioLINK's ETD Center

A alveolite é uma complicação pós-operatória de carácter inflamatório que acomete alvéolos de dentes recém-extraídos. A incidência dessa complicação varia de 1 a 4% e pode chegar a 30%. O objetivo deste estudo foi analisar os mecanismos biológicos envolvidos no processo de reparo de alvéolos intencionalmente infectados, em ratos; comparar diferentes modalidades de tratamento e correlacionar os resultados encontrados através de duas análises (microscópica e molecular). Foram utilizados 84 ratos, divididos nos grupos: I: alvéolo não infectado; II: alvéolo infectado sem nenhum tratamento; III: alvéolo infectado tratado com irrigação de solução de iodeto de sódio a 2% e peróxido de hidrogênio a 3% na proporção de 1:1; e IV: alvéolo infectado submetido à curetagem, irrigação com soro fisiológico e preenchimento com uma pasta à base de metronidazol. Os animais foram eutanasiados aos 6, 15 e 28 dias pós-operatório. Foi realizada a análise quantitativa da expressão de genes envolvidos no processo de reparo [colágeno tipo I (COL-I), fator de crescimento do endotélio vascular (VEGF), osteocalcina (OCN), fosfatase alcalina (ALP), runt-related transcription factor 2 (RUNX2) e fator de necrose tumoral alfa (TNF-\'alfa\')], através da RealTimePCR, correlacionando sua expressão com as características microscópicas observadas qualitativa e quantitativamente. Com base nos resultados da análise microscópica e molecular, podemos concluir que os marcadores RUNX2, OCN e TNF-\'alfa\' podem ser usados como indicadores para avaliar a neoformação óssea e a quantidade de infiltrado inflamatório em alveolite. Os marcadores ALP e VEGF não representaram adequadamente o que se observou microscopicamente. Embora o tratamento da alveolite com a pasta à base de metronidazol promova maior densidade de neoformação óssea aos 28 dias, não há diferenças entre os tratamentos.
Dry socket is an inflammatory postoperative complication that undertakes sockets of recently extracted teeth. The incidence of such complication varies from 1 to 4% and might reach up to 30%. The objective of this study was to analyze the biological mechanisms involved in the repair process of intentionally infected sockets in mice; compare different treatment conditions and correlate the results of two different analysis (microscopic and molecular). 84 mice were used in this study, divided according the following groups: I: uninfected socket; II: infected socket without any treatment; III: infected socket treated with irrigation of 2% sodium iodide and 3% hydrogen peroxide solution at 1:1 proportion; and IV: infected socket submitted to curettage, physiological saline solution irrigation and fulfillment with metronidazole base paste. The animals were killed at a postoperative period of 6, 15 and 28 days. A quantitative analysis was performed using a RealTimePCR to evaluate the genes expression involved [Collagen Type I (COL-I), vascular endothelial growth factor (VEGF), osteocalcin (OCN), alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2) and tumor necrosis factor-alpha (TNF-\'alpha\')], in the repair process, correlating its expression with the microscopic characteristics observed in both qualitative and quantitative manner. Based in the results of the microscopic and molecular analysis, it can be concluded that the RUNX2, OCN and TNF-\'alpha\' markers can be used as indicators to evaluate the dry socket bone neoformation and inflammatory infiltrate quantity. The ALP and VEGF markers did not represented appropriately what was observed microscopically. Although the dry socket treatment with metronidazole base paste promotes an increase in the bone neoformation density at 28 days, no difference was found among the treatments.

Cette thèse est consacrée à la conception d’un schéma de couplage entre un procédé de production d’hydrogène par le cycle thermochimique iode-soufre et un réacteur nucléaire. Le schéma du couplage proposé utilise un cycle moteur dont le travail produit sert directement au fonctionnement d’une pompe à chaleur. Cette association de cycles thermodynamiques a pour but de récupérer les rejets énergétiques à basse température d’un procédé afin de les revaloriser pour les besoins énergétiques à haute température de ce même procédé. Cette association est appliquée au couplage étudié. La construction du réseau de distribution d’énergie est réalisée par la méthode des pincements. Dans le cas d’un couplage conventionnel, le rendement de production d’hydrogène est de 22,0%. En intégrant l’association de cycles au couplage, le rendement de production est de 42,6%. Le rendement exergétique, représentatif de la qualité de l’utilisation de l’énergie, augmente de 58,7% à 85,4%
This thesis is devoted to the design of an assembly of a hydrogen production process by the thermochemical iodine-sulphur cycle and a nuclear reactor. The suggested coupling network uses a power cycle which produces a work which is directly used for the heat pump running. The purpose of this thermodynamic cycle association is to recover the rejected energy at low temperature of a process to provide the energy needs of this same process at high temperature. This association is applied to the studied coupling. The construction of the energy distribution network is designed by the pinch analysis. In the case of a conventional coupling, the efficiency of hydrogen production is 22. 0%. By integrating the associated cycles into the coupling, the efficiency of production is 42. 6%. The exergetic efficiency, representative of the energy using quality, increases from 58. 7% to 85. 4%

L’ion fluorure est beaucoup plus réactif dans l'acétonitrile que dans l'eau, à cause de sa faible solvatation. Des différences profondes se manifestent entre l'échelle pF- et les diagrammes E-pF-, établis dans les deux milieux. La réaction des fluorures sur l'iode dépend de la nature du sel utilisé

Cette étude se situe dans le cadre des recherches menées par le CEAEA sur la production massive d'hydrogène, sans émission de gaz à effet de serre, via un cycle thermo-chimique de décomposition de l'eau couplé à une source de chaleur à haute température d'origine nucléaire. Dans le cas particulier du cycle dit« Iode-Soufre», on doit extraire H2 à partir d'un mélange H2/HI/H20 très corrosif, opération pour laquelle des procédés membranaires ont été proposés. L'objectif de ce travail est le développement de membranes zéolithiques de type MFI susceptibles d'être utilisées dans ce contexte. Nous présentons les différents matériaux utilisés, la méthodologie de synthèse de couches minces de Silicalite-1 et de ZSM-5 synthétisée sans structurant organique, les techniques de caractérisation des membranes. Une étude cinétique nous a permis d'optimiser et de contrôler les conditions d'obtention de ces couches minces déposées sur des substrats tubulaires en Ti02 et plans en Al2O3-α. De nombreuses expériences de perméation ont été réalisées, pour des gaz simples (H2, He, Ar, N 2, C02, SF6) et des mélanges gazeux (H2/H20/Ar) et (H2/H20/HI/Ar). Les effets de la température, de la pression amont, de l'épaisseur et de la longueur de la couche mince ainsi que du gaz vecteur ont été étudiés en détail. Il apparaît que la présence de molécules d'H20 dans le système joue un rôle prépondérant sur la perméation des autres molécules
In the general context of massive and "carbon free" hydrogen production studies, the aim of this work was the development of zeolitic MFI membranes for hydrogen extraction and separation. The methodology of synthesis, the membranes characterization techniques as well as the permeation experimental setup are presented. Optimization and control of the elaboration of Ti02 supported Silicalite-1 and template free ZSM-5 membranes have been reached. Details of the full kinetic study that we performed are given. Numerous permeation experiments, involving pure gas (H2, He, Ar, N2, C02, SF6) and mixtures (H2/H20/Ar) and (H2/H 20/HI/Ar) have been carried on. The effects of temperature, feed pressure, thickness and length of the membranes, as well as the role of the sweeping gas have been emphasized. In the case of gas mixtures, the presence of H20 molecules appears to be a predominant factor

Layered doubly hydroxides (LDHs) also known as hydrotalcites or anionic clays are a group of clay minerals that have shown promise for the removal of toxic anions from water through both anion exchange and a process known as the reformation effect. This project has involved the preparation and characterisation of LDH materials as well as the investigation of their ability to remove selected anions from aqueous solutions by the reformation effect. The LDH materials were successfully prepared from magnesium, aluminium, zinc and chromium chloride salts using the co-precipitation method. Samples were characterised using powder X-ray diffraction (XRD) and thermogravimetry (TG) to confirm the presence of LDHs. Powder XRD revealed a characteristic LDH structure for all LDH samples. Thermal Analysis showed decomposition usual occurred through a three or four step process as expected for LDHs. Preliminary investigations of the removal of sulfate, nitrate and fluoride by an Mg/Al LDH were carried out, and the products were characterised using XRD and TG which showed that an LDH material similar to the original hydrotalcite was formed after reformation. A Zn/Al LDH was investigated as a potential sorbent material for the removal of iodine and iodide from water. It was found that the LDH was a suitable adsorbent which is able to remove almost all of the iodine present in the test solutions. Again, the products were characterised by XRD, TG and evolved gas mass spectrometry (EGMS) in an attempt to better understand the iodine removal process. Powder XRD showed successful reformation of the LDH structure and TG/EGMS showed that only a small amount of iodine species were lost during thermal decomposition. Finally, the mineral stichtite a Mg/Cr LDH was successfully synthesised and investigated using XRD, TG and EGMS. Unfortunately, due to lack of time it was not possible to identify any new uses for the mineral stichtite in the current project.

I. Etude des mécanismes de relaxation mis en jeu dans Cl2, Br2, I2 isolés en matrice, après excitation en UV proche ou lointain : émission structurée (transitions vibroniques) pour Cl2en UV proche et transitions électroniques avec interaction Rydberg-Valence en UV lointain; émission dans le visible pour Br2 et I2 quelle que soit l'énergie d'excitation; étude théorique des processus de relaxation. II. Observation d'ions moléculaires simplement ou doublement chargés, formés par échange de charge simple ou double étudié par spectrométrie de translation; analyse des règles de sélection : conservation du spin et observation des seuls états singlets pour Cl2, influence croissante du couplage spin-orbite lorsqu'on passe de Cl2, à Br2 puis I2.

Pacientes com câncer diferenciado de tireoide (CDT) são submetidos à tireoidectomia e usualmente necessitam de tratamento adjuvante para ablação do tecido tireoidiano remanescente. Para ocorrer uma captação de radioiodo adequada, é necessário elevar os níveis de TSH através da suspensão da reposição do hormônio tireoidiano (T3 ou T4), o que gera um quadro clínico de hipotireoidismo. Como alternativa, o TSH humano recombinante (rec-hTSH) foi desenvolvido e com seu uso, não é necessário suspender a reposição do hormônio, impedindo, assim, os sintomas observados quando da suspensão deste. O objetivo deste trabalho foi calcular a dosimetria para os restos tireoidianos e demais órgãos de 22 indivíduos com CDT, dos quais 11 pacientes receberam a terapia com 131I (grupo A) sob estímulo endógeno com supressão da reposição hormonal, e os outros 11, receberam o radioiodo precedido de rec-hTSH (grupo B), na vigência de hormonioterapia substitutiva; e comparar os resultados dosimétricos com os possíveis efeitos deletérios da radiação. A partir da metodologia do MIRD e dos softwares MIRDOSE-3 e OLINDA, foram calculadas as doses absorvidas para a região da tireoide e para o corpo inteiro. Com um detector Geiger-Müller foram realizadas medidas de taxa de exposição durante a internação para cálculos de meia-vida efetiva (Teff) e foram coletadas amostras sanguíneas para verificação de aberrações cromossômicas. As doses absorvidas médias para o corpo inteiro obtidas foram de 0,96 ± 0,23 Gy para o grupo A e 0,44 ± 0,21 Gy para o grupo B. Os valores de Teff também foram menores para o grupo B (11,2 ± 1,9 h) quando comparados aos do grupo A (13,9 ± 2,4 h). A análise citogenética mostrou a presença de vários tipos de aberrações cromossômicas estruturais. O cromossomo dicêntrico foi o mais frequentemente encontrado e pode ser considerado o melhor indicador de dano por radiação ionizante. As diferenças entre os valores de aberrações encontradas para os dois grupos não foram significativas, com o número de células afetadas relativamente pequeno, não causando danos severos durante o tratamento. A obtenção de doses e Teff menores para os pacientes do grupo B está de acordo com o descrito na literatura. O clareamento renal do radioiodo é mais rápido com o rec-hTSH (conforme observado com a dosimetria interna), mas a captação e consequente ablação ocorrem em taxas similares (como se observa pela análise citogenética). Portanto, com os resultados obtidos, o rec-hTSH se mostrou uma ferramenta útil ao dispensar a suspensão do hormônio tireoidiano, mantendo a qualidade de vida dos pacientes e auxiliando para uma menor irradiação dos tecidos extratireoidianos
Patients with differentiated thyroid cancer (DTC) are submitted to a thyroidectomy and usually require adjuvant therapy to ablate the remaining thyroid tissue. In order to have an adequate uptake of radioiodine, it is necessary to increase TSH levels by thyroid hormone withdrawal, which leads to a hypothyroidism state. As an alternative, the use of recombinant human thyroid stimulating hormone (rec-hTSH) may prevent the hormonal therapy withdrawal; therefore avoiding the hypothyroidism symptoms. The aim of this study was to calculate the dosimetry for thyroid remnants and total body of 22 individuals with DTC, of which 11 patients received 131I (group A) under endogenous stimulus, and the other 11 received 131I preceded by rec-hTSH (group B), and compare the dosimetric results with the potential harmful effects of radiation. Using the MIRD methodology and softwares MIRDOSE-3 and OLINDA, the absorbed doses were calculated for thyroid region and total body. Measurements of the exposure rates were made with a Geiger-Müller detector during the hospital stay, in order to calculate the effective half-lives (Teff), and blood samples were collected to verify chromosome aberrations. The average absorbed doses to the whole body obtained were 0.96 ± 0.23 Gy for group A and 0.44 ± 0.21 Gy for group B. Teff values were also lower for group B (11.2 ± 1.9 h) when compared to the results of group A (13.9 ± 2.4 h). The cytogenetic analysis showed the presence of various types of structural chromosome aberrations. The dicentric chromosome was the cytogenetic abnormality most frequently found and is considered to be the best indicator of ionizing radiation damage. The differences between the values of aberrations found in both groups were not significant, being the number of affected cells relatively small, causing no severe damage during treatment. The smaller doses and Teff obtained from the patients in group B are in agreement with the literature. The renal clearance of radioiodine is faster with rec-hTSH (as seen with the internal dosimetry), but the uptake and subsequent ablation occur at similar rates (as observed by cytogenetic analysis). Therefore, according to the above mentioned results, it is possible to observe that rec-hTSH is an useful alternative to the endogenous stimuli, while maintaining the patients\' quality of life and helping to reduce irradiation of extrathyroidal tissues

This thesis describes the use of copper and palladium to mediate transformations of carboranes, especially p-carborane.

1-(1-p-carboranyl)-N-methyl-N-(2-butyl)-3-isoquinolinecarboxamide, a carborane containing analogue of the peripheral benzodiazepine receptor (PBR) ligand PK11195, has been synthesised. A key step in the reaction is the copper (I) mediated coupling of p-carborane with ethyl 1-bromo-isoquinoline-3-carboxylate.

p-Carborane has been arylated on the 2-B-atom in high yields, using the Suzuki–Miyaura reaction. Thus the reaction between 2-I-p-carborane and various arylboronic acids [1-naphthyl-, phenyl-, 4-MeO-C₆H₄-, 3-CH₃CONH-C₆H₄-, 4-NC-C₆H₄-, 3-NO₂-C₆H₄-], gave the corresponding 2-aryl-p-carboranes in DME solution when reacted in the presence of cesium fluoride and the catalytic Pd₂(dba)₃–dppb system. Under the same conditions, the boron-boron bond forming reaction of two p-carboranylboronic esters (2-[(pinacolato)boron]-p-carborane and 2-[(neopentyl glycolato)boron]-p-carborane) was also shown feasible.

p-Carborane has been vinylated on the 2-B-atom in high yields by use of the Heck reaction. The coupling between 2-I-p-carborane and various styrenes [4-H-, 4-C₆H₄-, 4-Cl , 4-Br-, 4-NO₂-, 4-CH3O- and 4 CH₃ ] resulted in the formation of the correspondingtrans-β-(2-B-p-carboranyl) styrene in DMF solution when reacted in the presence of silver phosphate and the palladacycle Herrmann´s catalyst. The reaction was shown to proceed at higher rate with electron rich than with electron deficient olefins.

The feasibility of palladium-catalysed isotopic exchange of an iodinated closo-carborane with a radioisotope of iodine has been studied. 2-I-p-carborane was selected as a model compound. It was shown, that such isotopic exchange is possible and provides a high yield (83 ± 4.2 %) during 40 min long reaction. The reaction conditions were optimised, and it was demonstrated that presence of the tetra n-butylammonium hydrogensulphate is important in order to stabilise catalyst and provide reproducibility of labelling. In this work we have modified the methodology and extended the application to a wider range of iodinated carboranes. By the use of Herrmann’s catalyst in toluene at 100 °C this [¹²⁵I]-iodide labelling could be improved and extended. 2-I-p- 9-I-m-, 9-I-o-, 3-I-o-carborane, 1-phenyl-3-I-o-carborane and 1,2-diphenyl-3-I-o-carborane could be [¹²⁵I]-iodide labelled in high to excellent yields within 5 minutes.This reported palladium catalyzed radio-iodination of the uncharged closo-carboranes might find use in pharmacokinetic studies of carborane derivatives.

En cas accident grave dans un réacteur à eau pressurisée (REP), des Produits de Fission sont susceptibles d’être rejetés dans l’enceinte de confinement. Le manque de données expérimentales validées sur la chimie de l’iode dans ce type de conditions constitue un frein au développement de codes de calculs prédictifs. Pour remédier à ces lacunes, un réacteur expérimental de type brûleur à flamme plate a été développé afin d’établir une base de données expérimentales caractéristiques du système {I,O,H} via l’étude de flammes H2/H2O/O2/Ar enrichies en iode (HI). Les profils d’évolution de la température et d’espèces chimiques (HI, H2O, OH) présentes dans le milieu réactionnel ont été mesurés par différentes méthodes analytiques appropriées (IRTF, FIL, absorption laser). Des essais complémentaires ont été réalisés sur un réacteur à écoulement permettant l’injection d’iode moléculaire dans un flux d’hydrogène ou de vapeur d’eau dans des conditions de température représentatives. Les espèces iodées gazeuses formées ont été quantifiées par ICP-MS et par spectrométrie UV-Visible. La base de données expérimentale établie a servi de base pour le développement d’un mécanisme cinétique détaillé capable de rendre compte de la chimie de l’iode dans des conditions représentatives d’une situation accidentelle. La modélisation cinétique a été réalisée à l’aide du code PREMIX pour les essais en condition de flamme et avec le code SOPHAEROS pour les essais sur réacteur. La comparaison expérience-modélisation a permis de valider le mécanisme et une analyse des voies réactionnelles a également permis de mettre en évidence les réactions prépondérantes impliquées dans la chimie de l’iode
To assess kinetics aspects of iodine chemistry in an environment of a severe accident in a Pressurized Water Reactor (PWR), at the laboratory scale, an experimental reactor named “flat flame burner” has been implemented. Low pressure flames of H2/O2/Ar premixed gas seeded with known amounts of iodhydric acid and steam were studied. The quantification of chemical species (HI, H2O, OH) in such environment was obtained by specific analytical techniques (Fourier Transform InfraRed absorption spectrometry, FTIR and Laser Induced Fluorescence, LIF), the evolution of the temperature was determined by LIF and by thermocouple measurements. Further assays were performed in a flow reactor in which gaseous molecular iodine was injected and transported in a stream or hydrogen flow and a strong temperature gradient, representative of the primary circuit in the case of a severe accident. The resulting gaseous species (I2 and HI) were quantified by ICP-MS and UV-Visible spectrometry. This experimental database has been used as a support to develop a detailed kinetic mechanism for the {I, O, H} system. It is composed of 37 reversible reactions involving 5 iodinated species. The thermokinetic parameter database has been actualized by using theoretical chemistry tools and also completed with data found in the literature. Modelling was performed by using the PREMIX code for flame assays, and with the in IRSN’s severe accident simulation code ASTEC/SOPHAREOS code for flow reactor assays. The comparison between experiment and modelling shows that this detailed mechanism is able to reproduce the iodine chemistry in conditions representative of a PWR severe accident

Nous avons etudie par topographie aux rayons x, en utilisant principalement le rayonnement synchrotron, des monocristaux sous champ electrique tels que la forme alpha de l'iodate de lithium (-liio#3), l'orthophosphate potassium titanyl (ktp=ktiopo#4) et le niobate de lithium (linbo#3). Ces etudes ont ete menees dans le but d'elucider les mecanismes de formation des gradients de distorsion sous champ. Nous avons observe sur les topographies les effets qui se produisent sur les cristaux de -liio#3 et ktp lorsqu'un champ electrique est applique suivant l'axe c. Les resultats nouveaux, surtout les mesures en courant alternatif et les experiences a basse temperature, ont montre que la conductivite ionique unidimensionnelle n'est pas un phenomene preponderant a la base des lignes paralleles a l'axe c observees sous champ, comme cela a ete suppose jusqu'a present. Ceci nous a permis de remettre en cause les modeles mentionnes dans la litterature, et de proposer notre modele des canaux polarises. Sur les cristaux de linbo#3 (et -liio#3) implantes par l'hydrogene nous avons observe, sur les topographies en section, la couche associee a l'implantation. Les experiences ont montre que la couche implantee est monocristalline, legerement desorientee par rapport au volume, observable sans champ. Sous champ, elle n'est pas visible. Par contre, la couche traversee par les ions implantes est, sous champ, a l'origine de l'observation d'une ligne parallele a la surface, plus desorientee par rapport au volume que la couche implantee sans champ. La desorientation de cette image de la zone traversee semble etre fortement correlee avec l'effet piezoelectrique. Nous proposons deux hypotheses qui pourraient expliquer ce phenomene

Thermochemical water splitting cycles have been conceptualized and researched for over half a century, yet to this day none are commercially viable. The heavily studied Sulfur-Iodine cycle has been stalled in the early development stage due to a difficult HI-H₂O separation step and material compatibility issues. In an effort to avoid the azeotropic HI-H₂O mixture, an imidazolium-based ionic liquid was used as a reaction medium instead of water. Ionic liquids were selected based on their high solubility for SO₂, I₂, and tunable miscibility with water. The initial low temperature step of the Sulfur-Iodine cycle was successfully carried out in ionic liquid reaction medium. Kinetics of the reaction were investigated by I₂ colorimetry. The reaction also evolved H₂S gas, which led to the conceptual idea of a new Sulfur-Sulfur thermochemical cycle, shown below:
4I₂(l)+4SO₂(l)+8H₂O(l)↔4H₂SO₄(l)+ 8HI(l)
8HI(l)+H₂SO₄(l)↔ H₂S(g)+4H₂O(l)+4I₂(l)
3H₂SO₄(g)↔ 3H₂O(g)+3SO₂(g)+1½O₂(g)
H₂S(g)+2H₂O(g)↔ SO₂(g)+3H₂(g)
The critical step in the Sulfur-Sulfur cycle is the steam reformation of H₂S. This highly endothermic step is shown to successfully occur at temperatures in excess of 800˚C in the presence of a molybdenum catalyst. A parametric study varying the H₂O:H₂S ratio, temperature, and residence time in a simple tubular quartz reactor was carried out and Arrhenius parameters were estimated. All reactive steps of the Sulfur-Sulfur cycle have been either demonstrated previously or demonstrated in this work. A theoretical heat-to-hydrogen thermal efficiency is estimated to be 55% at a hot temperature of 1100 K and 59% at 2000 K. As a highly efficient, all-fluid based thermochemical cycle, the Sulfur-Sulfur cycle has great potential for feasible process implementation for the transformation of high quality heat to chemical energy.
Graduation date: 2012

Pathogenic viruses are frequently introduced into marine and estuarine waters through the discharge of treated and untreated sewage, since current treatments are unable to provide virus-free wastewater (WW) effluents, affecting the receiving waters quality and, consequently, human health. The removal of harmful constituents by the conventional treatments comprises a combination of chemical, physical and biological methods. Usually, WW from urban areas is secondarily, rarely tertiary, treated. Although the secondary effluent contains high concentrations of microorganisms, the effect of water dilution makes it acceptable in terms of quality indicators. In tertiary treatment, chlorination is the most common method used to ensure microbiological safety in tertiarily treated effluents. However, its massive utilization, both in free and combined chlorine forms, may lead to the formation of chemical disinfection by-products though the reaction with organic matter present in the effluents, being those chemicals toxic to aquatic organisms, representing potential health hazards. Unfortunately, these conventional methods are limited and may not be adequate to reach the quality levels specified by the guidelines. Photodynamic therapy (PDT) with porphyrins may be a promising approach for the inactivation of pathogens as they are effective in inactivating microorganisms without the formation of potentially toxic products. Some studies have reported an enhancer effect on antimicrobial photodynamic therapy (aPDT) by the combined used of some photosensitizer (PS) with potassium iodide (KI) and hydrogen peroxide (H2O2). The main objective of this study was to evaluate the aPDT efficacy of a PS based on a low-cost formulation constituted by five cationic porphyrins (Form) and its potentiation effect by KI and H2O2 in the inactivation of a T4-like bacteriophage in WW. The experiments were done in phosphate buffered saline and in filtered and non-filtered contaminated wastewater. The aPDT assays in filtered WW (0.45 μm pore-size) were performed with different concentrations of Form (1.0 to 10 μM). In a second phase was evaluated the effect of KI (100 mM) in the photodynamic action of Form (1.0 to 10 μM). The results of these experiments demonstrated that Form is efficient in filtered WW treatment and that the efficacy of bacteriophage photoinactivation is correlated with the concentration of the used PS. When combined with KI, the Form is clearly less effective to inactivate the bacteriophage. To evaluate if the organic matter present in water influences the efficiency of PS, the WW was filtered using three different pore-sized membranes (0.45, 0.30 and 0.22 μm). The results demonstrated that the increase of organic matter promote a significant decrease in the efficiency of Form. In order to evaluate if the efficiency of aPDT to inactivate bacteriophages is maintained when the treatments are performed in non-filtrated WW, the effect of Form alone (10 μM) and combined with H2O2 (2, 5 and 9%) in non-filtered WW was evaluated. The Form alone proved to be an efficient PS to photoinactivate the bacteriophage in non-filtered WW, but the presence of H2O2 enhanced the photodynamic effect. The FORM can be an effective alternative to control viruses in WW, particularly if combined with H2O2.
Os vírus patogénicos são frequentemente introduzidos nas águas marinhas e estuarinas através da descarga de esgoto tratado e não tratado, uma vez que os tratamentos atuais não inativam os vírus presentes nas águas residuais (WW), afetando a qualidade das águas recetoras e, consequentemente, a saúde humana. Nos tratamentos convencionais, a remoção de constituintes nocivos consiste no uso de métodos químicos, físicos e biológicos. Geralmente, a WW de áreas urbanas é tratada secundariamente e não terciariamente. Embora o efluente secundário contenha altas concentrações de microrganismos, o efeito da diluição na água torna-o aceitável em termos de indicadores de qualidade. A cloração é o método mais comum usado para garantir a segurança microbiológica em efluentes tratados terciariamente. No entanto, a sua utilização maciça, tanto na forma de cloro livre como combinada, pode levar à formação de subprodutos químicos como resultado da reação com a matéria orgânica presente nos efluentes, sendo esses produtos químicos tóxicos para os organismos aquáticos, apresentando riscos para a saúde. Os métodos convencionais são limitados e podem não ser adequados para manter os níveis de qualidade especificados nas diretrizes. As porfirinas quando usadas como fotossensibilizadores (PS) na terapia fotodinâmica (PDT) podem ser desinfetantes promissores para a inativação de microrganismos patógenicos, pois são eficazes na inativação de microrganismos sem formação de produtos tóxicos. Alguns estudos mostraram efeito potenciador de alguns PS usados em terapia fotodinâmica antimicrobiana (aPDT) quando estes são usados em combinação com iodeto de potássio (KI) e peróxido de hidrogénio (H2O2). O principal objetivo deste estudo foi avaliar a eficácia da aPDT de um PS baseado numa formulação de baixo custo constituída por cinco porfirinas catiónicas (Form) e o seu efeito potenciador por KI e H2O2 na inativação de um bacteriófago tipo T4. As experiências foram realizadas em solução salina tamponada com fosfato e em água residual contaminada filtrada e não filtrada. Os ensaios de aPDT em WW filtrada (tamanho do poro de 0,45 μm) foram realizados com diferentes concentrações de Form (1,0 a 10 μM). Numa segunda fase foi avaliado o efeito do KI (100 mM) na ação fotodinâmica da FORM (1,0 a 10 μM). Os resultados dessas experiências demonstraram que a Form é eficiente no tratamento de WW filtrada e que a eficácia da fotoinativação de bacteriófagos está correlacionada com a concentração do PS usado. Quando combinada com o KI, a Form é claramente menos eficaz na inativação do bacteriófago. Para avaliar se a matéria orgânica presente na água influencia a eficiência do PS, a WW foi filtrada usando três membranas com tamanho de poros diferentes (0,45, 0,30 e 0,22 μm). Os resultados mostraram que o aumento da matéria orgânica promove uma diminuição significativa na eficiência da Form. Para avaliar se a eficiência da aPDT para inativar bacteriófagos é mantida quando os tratamentos são realizados em WW não filtrada, o efeito da Form sozinha (10 μM) e combinado com H2O2 (2, 5 e 9%) em WW não filtrada foi avaliado. A Form por si só provou ser um PS eficiente para fotoinativar o bacteriófago em WW não filtrada, mas a presença de H2O2 aumentou significativamente o efeito fotodinâmico. A Form pode ser uma alternativa eficaz para controlar vírus na WW, principalmente se combinada com H2O2.
This work was supported by funding FEDER through COMPETE – Programa Operacional Factores de Competitividade, and by National funding through Fundação para a Ciência e Tecnologia (FCT) and Marine Studies (CESAM).
Mestrado em Biologia Molecular e Celular

Dość pobieżnie dotąd scharakteryzowane hybrydowe organiczno-nieorganiczne półprzewodniki są interesującą grupą materiałów o potencjalnym zastosowaniu w elektronice, fotokatalizie, fotowoltaice, optoelektronice i pokrewnych dziedzinach badań. Siła oddziaływań obecnych w strukturze krystalicznej znajduje odzwierciedlenie w strukturze elektronowej, co można zaobserwować analizując dystrybucję gęstości stanów elektronowych poszczególnych materiałów. Silne oddziaływania (kowalencyjne i jonowe) w półprzewodnikach nieorganicznych pozwalają na tworzenie się ciągłych pasm w strukturze elektronowej. Po drugiej stronie stoją półprzewodniki czysto organiczne których, właściwości zależą w głównej mierze od słabych oddziaływań międzycząsteczkowych. Dużo słabsze oddziaływania van der Waalsa, wiązania wodorowe i oddziaływania typu π prowadzą do powstania wąskich pasm energetycznych. W przypadku półprzewodników hybrydowych oba przypadki są możliwe, a przewaga słabych lub silnych oddziaływań w strukturze krystalicznej determinuje właściwości materiału. Półprzewodniki hybrydowe reprezentowane są w niniejszej pracy przez tetrajodkowe kompleksy cyny z ligandami organicznymi ([SnI4{(C6H5)3PO}2], [SnI4{(C6H5)2SO}2] oraz [SnI4(C5H5NO)2]). Obecny w nich atom jodu charakteryzuje się dużym promieniem oraz polaryzowalnością, co sprzyja tworzeniu się słabszych wiązań i oddziaływań międzycząsteczkowych. W przypadku tych kompleksów główną rolę odgrywają oddziaływania wodorowe z atomami jodu łączące fragmenty organiczne i nieorganiczne sąsiadujących cząsteczek. Im słabsze oddziaływania międzycząsteczkowe w strukturze krystalicznej tym dyskretniejsza struktura pasmowa i bardziej płaskie pasma w strukturze elektronowej. Jeśli oddziaływania te są odpowiednio słabe może dojść do powstania przypadku granicznego, w którym materiał może zostać sklasyfikowany jako izolator posiadający jednak jeszcze pewne cechy półprzewodnika. Przykładami tego typu materiałów są opisane w rozprawie organiczne sole trójjodkowe o dużych kationach organicznych. W ich strukturze krystalicznej brak silnych oddziaływań międzycząsteczkowych, a liniowo ułożone aniony I3 - są otoczone przez kationy zawierające liczne podstawniki aromatyczne. Mimo niewielkiej siły oddziaływania pomiędzy anionami trójjodkowymi orbitale atomów jodu budują zarówno krawędzie pasm walencyjnych jak i przewodnictwa. Inne słabe oddziaływania obecne w strukturze to oddziaływania wodorowe CH…I (w większości przypadków odległości H…I są zbyt duże aby nazywać je wiązaniami). Mimo niewielkiej mobilności nośników ładunku materiały te wydajnie generują fotoprądy w zakresie promieniowania ultrafioletowego, ponieważ zachodzi wówczas wzbudzenie elektronów do wyższych pasm przewodnictwa, na które składają się orbitale atomów węgla. Materiałem opierającym się głównie na silnych wiązaniach kowalencyjnych jest jodek ołowiu(II) - półprzewodnik szeroko opisany w literaturze. Głównym aspektem poruszanym w rozprawie jest tworzenie złącza Schottky'ego przez halogenki ołowiu(II) w kontakcie z powierzchnią niektórych metali. Stany powierzchniowe prowadzące do powstania bariery Schottky'ego mogą mieć swoje źródła w chemisorpcji cząsteczek półprzewodnika na powierzchni metalu, co może równocześnie powodować tzw. "pillow effect" przejawiający się redukcją pracy wyjścia metalu. Innym istotnym źródłem stanów powierzchniowych jest nakładanie się funkcji elektronowej metalu na stany obecne w przerwie energetycznej półprzewodnika wynikające ze skończonych rozmiarów kryształów. Niesymetryczne zapełnianie i opróżnianie stanów powierzchniowych obecnych na złączu PbI2|Cu zostało wykorzystane do zbudowania memrystora - elementu, który w wyniku przepływu ładunku zmienia swój opór. W pracy oprócz analizy mechanizmu działania tego urządzenia pokazano podobieństwo zbudowanego memrystora do synapsy oraz zastosowanie memrystora do prostej analizy sygnału. Opisany w pracy memrystor bazujący na złączu PbI2|Cu został wbudowany w układ rezerwuarowy - podtyp sieci neuronowej. Pozwoliło to na wykonanie prostych obliczeń, tj. na klasyfikację sygnałów ze względu na ich amplitudę. Innym zjawiskiem zaobserwowanym w tym układzie jest metaplastyczność. Efekt ten przejawia się jako zmiana podstawowych właściwości urządzenia ze względu na jego historię (tj. dłuższą ekspozycję na dodatni potencjał i związany z nim przepływ ładunku) i jest możliwy dzięki tworzeniu się dodatkowych oddziaływań pomiędzy metalem a półprzewodnikiem, które zmieniają opór takiego złącza. Źródłem tych nowych oddziaływań może być utlenianie atomów miedzi, które następnie mogą utworzyć wiązanie z obecnymi na powierzchni PbI2 atomami jodu. Działanie całego układu sprowadza się więc do oddziaływań powierzchni halogenku ołowiu(II) z powierzchnią metalu. W skład rozprawy wchodzi pięć publikacji poświęconych różnym aspektom fizykochemii półprzewodników oraz przetwarzaniu informacji. Trzy z tych publikacji koncentrują się na oddziaływaniach występujących w strukturach krystalicznych związków lub na granicy półprzewodnik/metal. Poddawane analizie związki różnią się znacząco składem i budową: 1) organiczne sole trójjodkowe oprócz anionu I3-zawierają duże kationy organiczne zawierające trzy lub sześć pierścieni aromatycznych; 2) jodkowe kompleksy cyny(IV) mają budowę molekularną a atom jodu jest związany jednym wiązaniem kowalencyjnym z atomem cyny; 3) jodek ołowiu(II) ma budowę warstwową, w której atom jodu ma rolę mostka łączącego sąsiednie atomy ołowiu. Odmienność przedstawionych struktur pozwala na prześledzenie różnorodnych oddziaływań - od silnych wiązań kowalencyjnych, jonowych przez słabsze π-π, wodorowe lub halogenowe, na oddziaływaniach van der Waalsa kończąc. Artykuły opisujące właściwości kompleksów SnI4 oraz soli trójjodkowych skupiają się na wpływie oddziaływania poszczególnych fragmentów struktury krystalicznej na strukturę elektronową, przewodnictwo, przerwę energetyczna, mobilność i koncentrację nośników ładunku, typ domieszkowania oraz potencjały krawędzi pasm. W publikacjach tych wykazane jest, że słabsze oddziaływania obecne w strukturze w dużych ilościach potrafią mieć dominujący wpływ na strukturę elektronową związku. Wyciągnięte wnioski poparte są między innymi pomiarami spektroktroskopowymi oraz obliczeniami teoretycznymi. W tych dwóch publikacjach zaprezentowano cztery nowe związki: [(C6H5CH2)3NO]2H+I3-, (C6H5CH2)3NH+I3- ∙ C6H5CH3, [SnI4{(C6H5)2SO}2] i [SnI4(C5H5NO)2] o nieopisanych wcześniej strukturach krystalicznych. Z kolei publikacja skupiająca się na urządzeniu zbudowanym na bazie PbI2 opisuje oddziaływania tego materiału z powierzchnią różnych metali (Au, Pt, Cu, Ag i Al) oraz wyjaśnia wpływ tego oddziaływania na barierę Schottky'ego, odpowiedzialną za działanie tego urządzenia. Rozprawę uzupełniają dwie prace przeglądowe, które dopełniają dwa nurty podjęte w pracy: pierwszy dotyczący analizy właściwości konkretnej grupy półprzewodników (chalkohalogenków) oraz drugi związany z budowaniem urządzeń na podstawie materiałów półprzewodnikowych i wykorzystaniem ich w bardziej skomplikowanych układach. W pierwszym przeglądzie nakreślono jak w obrębie jednej grupy związków - chalkohalogenków o stechiometrii MQX (gdzie: M = As, Sb, lub Bi; B = Se, S lub O; X = F, Cl, Br lub I) - zmiany polegające na wymianie atomu fluorowca lub stosunku atomów w cząsteczce wpływa na strukturę związku. W pracy tej zebrano informacje o strukturach różniących się między sobą jedynie atomem M, Q lub X, a także opisano cechy wspólne tych struktur i ich główne różnice. Dla części opisanych struktur możliwe okazało się też powiązanie tych niewielkich zmian strukturalnych ze zmianami w strukturze elektronowej. Drugi przegląd przedstawia między innymi obecny stan wiedzy na temat fotomemrystorów i układów wykazujących właściwości fotomemrystywne, ze szczególnym uwzględnieniem mechanizmu ich działania. W przeglądzie tym poruszono również tematykę obliczeń rezerwuarowych, zasady działania rezerwuarów, a także ich możliwe zastosowanie.
Quite briefly characterized hybrid organic-inorganic semiconductors are an interesting group of materials with potential applications in electronics, photocatalysis, photovoltaics, optoelectronics and related fields. The properties of molecular compounds depend profoundly on the weak intermolecular interaction. The strength of the interactions present in the crystal structure is reflected in the band structure and can be observed in the distribution of the density of the electronic states of individual materials. Strong interactions (covalent and ionic) in the inorganic semiconductors allow formation of continuous energy bands. On the other hand, much weaker van der Waals interactions, hydrogen bonds and stacking of the aromatic rings that occur in the purely organic semiconductors lead to narrower energy bands. In the case of hybrid semiconductors, both scenarios are possible and the predominance of weak or strong interactions in the structure determines the properties of the material. The hybrid semiconductors are represented in this dissertation by the tin-iodide complexes with organic ligands ([SnI4{(C6H5)3PO}2], [SnI4{(C6H5)2SO}2] and [SnI4(C5H5NO)2]). The iodine atoms present in these compounds are characterized by a large radius and polarizability which favors the formation of weaker bonds and intermolecular interactions. In these complexes, hydrogen interactions with iodine atoms combine the organic and inorganic fragments of the adjacent molecules. The weaker intermolecular interactions in the structure, the more discrete band structure and the more flat bands in the electronic structure. If these interactions are sufficiently weak, a border case may arise in which the material can be classified as an insulator with some of semiconductor features. This scenario in this work is represented by the organic triiodide salts. The crystal structures of these salts lack any strong intermolecular interactions and the linearly arranged I3 - anions are surrounded by large organic cations. Despite the weak interactions between the triiodide anions, orbitals of iodine atoms build both the edges of the valence and the conduction bands. Other weak interactions present in the structure encompass hydrogen interactions CH...I (distances H...I are usually too large to be called bonds). Despite their low charge carriers mobility, these materials efficiently generate photocurrents under the ultraviolet radiation due to the excitation of the electrons to the higher conduction bands that consist mostly of orbitals of the carbon atoms. The material based mainly on strong covalent bonds is lead (II) iodide - a semiconductor well described in the literature. Interestingly, PbI2 creates a Schottky junction with the surface of several metals. Surface states that lead to the formation of this barrier may have their sources in the chemisorption of a semiconductor molecules on the surface of the metal which may also cause the so-called "pillow effect" which reduces the work function of the metal. Another important source of surface states is the overlap of the electronic function of the metal with the electronic states (present in the energy gap of the semiconductor) created due to the finite dimensions of the crystals. An asymmetric filling and emptying of the surface states present at PbI2|Cu junction have been used to build a memristor - an element that changes its resistance as a result of the flow of the charge. In this work the analysis of the mechanism of operation of this device, the similarity of the constructed memristor to synapse and the use of a memristor for simple signal analysis are presented. The memristor was built into the reservoir system - a sub-type of the neural network - which allowed to perform simple calculations, e.g. on the classification of signals due to the amplitude. Another phenomenon observed in this system is metaplasticity. This type of neuromimetic behaviour manifests as the change of the basic properties of the device due to its history (i.e. flow of charges under prolonged positive bias). This effect is possible due to the formation of additional interaction between the metal and the semiconductor that changes the resistance of such joint. An example of this is an oxidation of the copper atoms that can subsequently form a bond with the iodine atoms present on the surface of PbI2. The operation of this entire system comes down to the interface interactions between the lead(II) halide and metal surface. This dissertation consists of five publications focusing on the physical chemistry of semiconductors and various aspects of information processing. Presented compounds differ significantly in composition and structure: 1) organic triiodide salts contain - in addition to the anion I3- large organic cations containing three or six aromatic rings; 2) tin(IV) iodide complexes have a molecular structure where the iodine atoms are bound by one covalent bond to a tin atom; 3) lead iodide(II) has a layered structure in which the iodine atom has the role of a bridge connecting neighbouring lead atoms. The diversity of the presented structures allows to investigate various interactions - strong covalent bonds, ionic bonds, weaker π-π interactions, hydrogen or halogen bonds and van der Waals interactions. The article that describes the properties of SnI4 complexes and triiodide salts focus on the impact of the individual structural elements on the electronic structure, e.g. conductivity, energy gap, mobility, type of doping and carrier concentration, and band edge potentials. In these publications it is shown that the weaker interactions present in the structure in large quantities can have a dominant influence on the electronic structure of the compound. The conclusions drawn are supported, among others, by spectroscopic measurements and theoretical calculations. Four compounds presented in this two articles: [(C6H5CH2)3NO]2H+I3-, (C6H5CH2)3NH+I3- ∙ C6H5CH3, [SnI4{(C6H5)2SO}2] and [SnI4(C5H5NO)2] are new with a structure that has never been described before. The third publication is focused on the device based on PbI2 and describes the interaction of this material with the surface of various metals (Au, Pt, Cu, Ag and Al). It also explains the effect of this interaction on the Schottky barrier responsible for the operation of this device. The dissertation is completed by two review papers that expands two topics taken in this work: the systematic analysis of the properties of the chalcohalogenides and the construction of the devices based on various semiconductors and their use in more complex systems. The first review outlines how in one group of compounds - chalcohalogenides with the stoichiometry MQX (where: M = As, Sb, or Bi; B = Se, S or O; X = F, Cl, Br or I) - the replacement of a halogen atom or the atomic ratio of atoms in the molecule affects the structure of the compound. In this work it was possible to gather information about structures differing only in M, Q or X atoms, to find the common features of these structures and their main differences. For some of the described structures, it was also possible to link these small structural differences with the changes in the electronic structure. The second review presents, among others, the current state of knowledge on photomemristors and systems exhibiting photomemristic properties, focusing on the mechanism of their operation. The review also touches on the subject of reservoir calculations, the principles of their work and their possible application.

129I is of major concern because of its biophilic nature, excessive inventory, long half-life (~16 million yrs), and high mobility in the natural environment that depends on its chemical speciation. Iodide (I-) has the highest mobility than iodate (IO3-) and is the predominant species in the terrestrial environment due to prevailing pH and Eh conditions. In order to transform I- to less mobile organo-iodine (OI), strong oxidants are necessary to activate the first electron transfer step from I- to reactive intermediates. The aim of this study was to determine the influence of naturally occurring aerobic bacteria isolated from an 129I contaminated aquifer (F-area of the Savannah River Site, SC) on I- oxidation and OI formation. It was demonstrated that 3 of 136 strains accumulated I- (0.2~2%) in the presence of H2O2, when incubated in the presence of an environmentally relevant concentration of I- (0.1 microM). The accumulation was likely through electrophilic substitution resulting in the iodination of cellular constituents. The results indicated that culturable I--accumulating bacteria are not directly responsible for the high fraction of oxidized iodine species (IO3- and OI, >50% of total I) present in the SRS F-area. Several bacterial strains were found to be capable of stimulating I- oxidation through excretion of oxidants and enzymes. Organic acids in spent liquid medium from 27 of 84 aerobic bacterial cultures enhanced H2O2-dependent I- oxidation 2-10 fold. Organic acids enhanced I- oxidation by (1) lowering the pH of the spent medium and (2) reacting with H2O2 to form peroxy carboxylic acids, which are strong oxidizing agents. In the absence of H2O2, spent medium from 44 of 84 bacteria cultures showed I- oxidizing capacities. One I- oxidizing bacterium was studied to characterize its extracellular I- oxidizing component(s). The I- oxidizing capability from the spent medium was inactive by treatments with heat and H2O2 and absent under anaerobic conditions. Conversely, NADH, NADPH and FMN additions stimulated I- oxidation in the spend medium. These results indicate an oxidase(s) catalyzed I- oxidation. Understanding the bacterial activities involved with I- oxidation and OI formation is expected to help reduce 129I mobility in water-soil systems.

Iodine is considered an essential nutrient as lack can cause severe metabolic and neurological issues in adults, with the added consequence of permanent developmental damage in children and infants. However, excessive iodine intake can result in similar symptoms, with a wide variance in adverse health outcomes. The safe range of iodine intake may be relatively low, with some studies suggesting the possibility of a high frequency of subclinical cases of iodine poisoning going unnoticed or misdiagnosed.

In this study, the zebrafish model was tested as an integrative whole animal model to demonstrate behavioral, morphological, and genetic responses to overt and subclinical iodine poisoning in developing humans. Zebrafish embryos were treated with sodium iodide (NaI) immediately after fertilization. Survivability was monitored every 24 hours until 120 hours post fertilization (hpf). Concentrations with no statistical significance on survival, plus the smallest dose of significant lethality were then examined using behavioral analysis at 120 hpf to compare both overt and subclinical outcomes. Morphology measurements of body length, head length, head width, brain length, swim bladder volume, jaw length, and ventral dissension were also recorded at 120 hpf. Gene expression of slc5a5, tpo, and tshba at 72 hpf was also measured using quantitative PCR (qPCR).

A significant decrease in survival rates were observed at 24 hpf for 25, 37.5, and 50 mM NaI treatments (p<0.0001). Morphological measurements taken at 120 hpf showed a significant increase in body length, head length, head width, jaw length, and swim bladder volume in the 10 mM NaI treatment group (p<0.0001) and a significant decrease in body length, head length, jaw length, and swim bladder volume in the 25 mM treatment group (p<0.0001). A ventral distension also developed near the location of the thyroid gland exclusively in the 25 mM group.

Behavioral analysis showed significant increases in movement for both the 10 mM and 25 mM treatment groups during dark phases (p<0.0001). The 25 mM treatment group had an increase in movement during dark phases for standard well environments (p<0.0001), but this did not hold true for larger well environments, instead trending towards a non-significant decrease (p>0.05). The 10 mM group had a significant decrease during the first light phase in standard wells (p=0.002), with a significant increase in the second light phase for large wells (p=0.005). There were no significant changes in the expression of selected genes associated with the thyroid pathway (slc5a5, tpo, or tshba) across all treatment groups (p>0.05).

Overall, the results suggest zebrafish larvae exhibit both overt and subclinical symptoms of excess iodine intake. Future studies are needed to determine internalization, biodistribution, clearance, and further characterization of adverse outcomes along the thyroid pathway for additional exploration into subclinical thyrotoxicosis due to excess iodine intake. Researchers should express caution with time points, as the Wolff-Chaikoff effect may influence exposure windows in zebrafish.

碩士
國立彰化師範大學
化學系
100
With the increased use of nuclear energy to meet our needs, nuclear waste management has become more important than ever. In our research, we previously created a cage type molecule, which was linked by three dynamic disulfide bonds, 1,3,5-triethyl-2,4,6-tris(2,2’-disulfanedianiliny[1]methyl)benzene (L). In this report, we used L and studied its behaviors of recognition and encapsulation of MeI and I2, two essential molecules in the nuclear waste. In toluene solution, MeI or I2 was captured inside the cavity of L through hydrogen bonding interactions and formed precipitates of LMeI or LI2, respectively. In addition, L showed a highly efficient capability to absorb I2(g) in its amorphous solid state, and LI2 was identified as a thermodynamically stable product by TGA measurement. We also used solid-state IR, solution NMR spectroscopies, and X-ray diffraction analyses to observe the interactions in LMeI or LI2. Besides, we synthesized a modified receptor 3, which does not have disulfide linkages, and studied its interactions with I2 or MeI through the analyses of IR, NMR spectroscopies. We also obtained the crystal structure of compound 5, which was the tri-methylated product of compound 3, and tried to give a reasonable explanation why the molecule L was not easily methylated.

Design and Development of Carbon-Carbon and Carbon-Heteroatom Bond Forming Reactions” is divided into two sections. Section-A, contains two chapters, describes the catalytic ability of iodine for cross coupling reactions. Section-B, divided into three chapters, presents the azidation of organic scaffolds under oxidative conditions. Section A Chapter 1 presents a C-H functionalization of tetrahydroisoquinolines using iodine as a catalyst under aerobic conditions.1 This methodology employs Cross Dehydrogenative Coupling (CDC) strategy as a key step, which is highly atom economical as it doesn’t require pre-functionalized starting materials.2 Owing to the importance of tetrahydroisoquinoline moiety which is present in the umpteen natural products, considerable attention has been put up to functionalize tetrahydroisoquinoline scaffold.3 Iodine a non-metal which is non-toxic was found to catalyze the C-H functionalization of tetrahydroisoquinolines with a variety of nucleophiles such as coumarin, alkyl phosphite, phenols, indoles, acetone and dialkyl malonoates were coupled to it. Significant mechanistic study has been carried out to find the possible intermediate and support the mechanistic proposal. A few representative examples are highlighted in Scheme 1.1 Synopsis Scheme 1: A CDC coupling of tetrahydroisoquinoline with variety of nucleophiles Chapter 2 describes the Cross Hetero Dehydrogenative Coupling (CHDC) reactions of amines, alcohols and sulfoximines with various phosphites.4 Phosphoramidates and phosphate esters are structural scaffolds that are present in a variety of biologically active molecules.5 The conventional methods for synthesizing phosphoramidates/phosphate esters largely involve treating alcohol/amine with appropriate phosphorus halides which generates stoichiometric amount of halogen waste.6 Due to the usage of stoichiometric reagents and difficulties associated with the reported methods, there is a need for developing a protocol which is catalytic and mild. Therefore, we developed a method which employs catalytic amount of iodine and aq. H2O2 as a sole oxidant under milder conditions. Using this methodology, variety of phosphoramidates, phosphorous triesters and sulfoximine derived Synopsis Scheme 2: Phosphorylation of amines, alcohols and sulfoximines phosphoramidates have been synthesized with great efficiency and environmentally benign conditions. A few representative examples are highlighted in Scheme 2.4 Section B Chapter 1 of Section B demonstrates a mild way of synthesizing quaternary azides from α-substituted active methylene compounds which will serve as surrogates for several unnatural amino acid derivatives.7 Azidation has emerged as one of the efficient methods to introduce nitrogen atom in to the organic molecules.8 Azides are versatile functional groups which can be converted to amine, amide, and nitro compounds by simple modification. Moreover, azides are potential handle for “click” chemistry and provide late stage modifications in drug candidates, biomolecules and polymers, etc.9 Azidation of 1,3-dicarbonyl compounds is challenging, as both azides and 1,3-dicarbonyl compounds are nucleophilic in nature. In this section of the thesis, azidation of 1,3-dicarbonyl compounds has been carried out using tetrabutyl ammonium iodide (TBAI) as a catalyst, aq. TBHP as an oxidant and TMSN3 as a azide source. This method uses water as a solvent under mild reaction conditions to generate Synopsis quaternary azides in good to excellent yields. This operationally simple, practical, mild and green method provides an opportunity for synthesizing a variety of azidated β-keto esters, amides and ketones in good yields, Scheme 3.7 The application of this methodology has been demonstrated by synthesising a few triazole and pyrazolone derivatives. Scheme 3: Azidation of 1,3-dicarbonyl compounds Chapter 2 of Section B comprises the azidation and peroxidation of β-napthol derivatives using dearomatization strategy. Azidation and peroxidation are efficient ways to introduce nitrogen and oxygen into organic molecules, which serve as surrogates for amines and alcohol functional groups. In the present study, the azidative or peroxidative dearomatization of naphthol derivatives have been described. The azidation of β-napthol derivatives has been achieved by using CuBr (5 mol %) as a catalyst, TMSN3 as an azide source and aq. TBHP as an oxidant. Whereas, the peroxidation β-napthol derivatives has been accomplished using CuBr (5 mol %) in the presence of aq. TBHP at ambient reaction conditions.10 The products obtained are naphthalenone derivatives, which serve as valuable Synopsis synthetic intermediates and has potential handle for further functionalization.11 Several α-amino or α-peroxy naphthalenones are synthesized using this method in good yields. The usefulness of the methodology has been illustrated by synthesizing a few chiral azides and peroxides in good yields and with moderate enantioselectivity Scheme 4.10 Scheme 4: Dearomatizative azidation and peroxidation of 2-naphthols Chapter 3 reveals the azidation of indole at C-2 position by employing CuBr (10 mol %) as a catalyst and aq. TBHP as an oxidant in acetonitrile under reflux conditions (Scheme 5).12 The C-H functionalization of indole at C-2 position is one of pivotal methods, since it paves a way for synthesizing a variety of indolo-alkaloids.13 Azide is a versatile functionality which can be converted to several other nitrogen containing functional groups such as Synopsis Scheme 5: Azidation of indoles amine, amide, triazole, etc.9 A variety of functional groups were tolerated under the reaction conditions, and furnished the azidated product in good to excellent yields. Through radical inhibition study, we presume that the reaction may be proceeding through radical mechanism. In Scheme 5, a few representative examples are depicted.

The sodium-iodide symporter (NIS) is expressed in the basolateral membrane of thyroid follicular cells and transports iodide into its interior. Its expression in thyroid cancers allows the use of radioactive iodine (RAI) as a therapeutic tool. Unfortunately, a significant proportion of patients lose the ability to uptake RAI due mainly to impairment of NIS function, without effective therapeutic alternatives. Our main purpose was to extend the analysis of the impact of the PI3K/Akt/mTOR and NF-κB oncogenic signalling pathways on NIS expression. In an attempt to achieve that goal we first determined if the activation of the canonical NF-κB pathway, induced by the tumour necrosis factor alpha (TNF-α), affects NIS transcriptional regulation. Next, we also evaluated the effect of simultaneous inhibition of PI3K and mTOR. This study pointed to a role of NF-κB on the down-regulation of NIS mRNA expression by treatment with TNF-α and phorbol 12-myristate 13-acetate (PMA) in PCCL3 cells. In the K1 cell line, which has very poor expression of NIS and a constitutively active PI3K pathway, we were able to restore NIS expression upon its inhibition. The extended knowledge of these pathways involved in the regulation of NIS will be relevant for the development of therapies for the enhancement of iodide uptake efficiency in RAI refractory thyroid carcinomas.

O simportador de sódio e iodo (NIS) é altamente expresso no tecido da tiróide. Uma vez que a expressão de NIS resulta na acumulação de iodeto, a sua expressão em células tumorais permite o uso de iodo radioativo (131I) no diagnóstico e no tratamento da doença. No entanto, os níveis de expressão de NIS e a absorção de iodo no carcinoma de tiróide são reduzidos quando comparados ao tecido normal. Estudos recentes mostraram que, embora desencadeadas por diferentes vias de sinalização, a estimulação da expressão de NIS envolve a indução da atividade da cinase mitogénica p38 pela GTPase RAC1. O nosso grupo também descreveu recentemente a sobre-expressão de RAC1b (uma variante hiperativa do RAC1) numa série de carcinomas papilares da tiróide, associada à mutação BRAF V600E. Notavelmente, a presença da mutação BRAF V600E tem sido igualmente correlacionada a uma diminuição da expressão do NIS. O objetivo do presente estudo foi investigar o papel das GTPases RAC1/1b na modulação da expressão do NIS e ainda desenvolver um sistema repórter para estudar e identificar reguladores pós-traducionais deste simportador. Utilizando como modelo experimental uma linha celular de tiróide normal, os resultados obtidos suportam um papel da sinalização RAC1/1b na regulação da expressão do NIS. RAC1b demonstrou ter um papel na inibição dos níveis de expressão do simportador, enquanto RAC1 demonstrou poder ter um papel na estimulação dos mesmos, ao reduzir a expressão do NIS após a sua inibição e ao induzir a ativação da cinase mitogénica p38. Este estudo suporta um efeito da sinalização RAC1/1b na regulação da expressão de NIS. A identificação de novos moduladores dos níveis funcionais deste simportador será de extrema relevância para o desenvolvimento de estratégias terapêuticas co-adjuvantes ao 131I que permitam um aumento da eficiência na captação de iodo por parte das células tumorais.
The sodium iodide symporter (NIS) is highly expressed in thyroid tissue. Since the expression of NIS results in the accumulation of iodide, its expression in tumor cells allows the use of radioactive iodine (131I) as a diagnostic and therapeutic tool. Recent studies showed that, although triggered by different intracellular signaling pathways, stimulation of NIS expression involves the induction of the p38 mitogenic kinase activity by the GTPase RAC1. Our group has recently described the overexpression of the RAC1b protein (a hyperactive variant of RAC1) in a number of papillary thyroid carcinomas with unfavorable outcome, carrying the activating mutation V600E in the mitogenic kinase BRAF. Notably, the presence of BRAF V600E mutation has been associated with downregulation of NIS. The aim of the present study was to investigate the role of RAC1/1b GTPases in modulating the expression of the symporter and also to develop a reporter system to study and identify post-translational regulators of this symporter. Using a normal thyroid cell line, the results obtained support a role for RAC1/1b signaling in the regulation of NIS expression. RAC1b was shown to play a role in inhibiting the expression levels of the symporter, whereas RAC1 seems to exert the opposite effect, since inhibition of endogenous RAC1 decreases the expression of NIS and it overexpression induces the activation of mitogenic p38 kinase. This study supports a role for RAC1/1b signaling in the regulation of NIS expression. The identification of new modulators of the functional levels of this symporter will be extremely relevant for the development of therapeutic strategies that allow an increase in the efficiency in 131I uptake by tumor cells.
Financiado por Bolsa Prof. E. Limbert Sociedade Portuguesa de Endocrinologia Diabetes e Metabolismo / Sanofi-Genzyme em Patologia da Tiróide

Iodine is an important element essential for higher animals. A large part of the global human population suffers from a lack of iodine; elucidation of transfer and mobility of this element in the environment, water, soil, air and in organisms is thus very important. The aim of this work was the elaboration and optimisation of the method for determination of very low concentrations of iodine in the waters. The mass spectrometry with inductively coupled plasma (ICP-MS) technique was used. It has been shown that using of different filter types during sample preparation had no significant effect on the content of impurities in the filtered sample. Antimony was recommended as an internal standard, despite commonly used elements (indium or tellurium). Samples were not preserved because nitric acid caused volatilization of iodine from the sample and the addition of aqueous ammonia had no significant effect. The optimised method was tested on several groups of water samples, including precipitation, surface water and lysimetric waters. From autumn 2009 to summer 2010, a part of the Blanice River (Šumava Mountains, South Bohemia) was sampled. The average content of iodine in samples ranged from 1.48 ? 0.30 ?g?dm-3 (April 2010) to 3.05 ? 0.38 ?g?dm-3 (July 2010). The average content of iodine in samples from all tributaries of the Blanice River ranged between 2.52 ? 1.63 ?g?dm-3 (March 2010) and 3.67 ? 1.37 ?g?dm-3 (July 2010). The concentration of iodine in the monitored surface waters did not change significantly along the flow of the river. The other two streams were sampled near Rapotín village (Jeseníky Mountains, north Moravia). The average contents of iodine were as follow: Annov (upper stream) 1.60 ? 0.65 ?g?dm-3, Annov (lower stream) 1.88 ? 1.18 ?g?dm-3, Salaš (upper stream) 1.77 ? 0.92 ?g?dm-3, Salaš (lower stream) 1.42 ? 0.58 ?g?dm-3. Generally, the data showed that considering iodine, the area of Šumava had slightly higher levels than those observed in the Jeseníky Mountains. Precipitation collected in the South Bohemia (Arnoštov village and city of České Budějovice) and in Jeseníky (Rapotín) contained less iodine compared to surface waters, and rarely exceeded 3 micrograms per liter of water. The situation has changed in the spring of 2010, because of the occurrence of volcanic dust and ash over the Czech Republic. This volcanic cloud came from the sudden activity of the Eyjafjallajökull Volcano (Iceland). In the mentioned period, the contents of iodine in precipitation were increased several times at all sample collection sites. This is an indirect evidence that iodine could be released during volcanic eruptions and transferred over long distances through the atmosphere. It turned out that the wastewater treatment plant can eliminate iodine in wastewater only partially. However, the wastewater treatment plants in the monitored region were too small to evaluate the overall impact on the environment. The maximum iodine content at the outlet of the wastewater treatment plant Prachatice town (South Bohemia) was 28.5 ?g?dm-3, which is several times higher than natural levels in the Živný stream, to which the treated water flows. Lysimetric water samples were collected from lysimeters installed in three nearby plots in Arnoštov village (Šumava, South Bohemia). The highest concentrations of iodine were found on plot where cattle were grazed. These values were significantly higher (average 4.38 ? 1.74 ?g?dm-3) than those obtained from a site used as hay meadow (average 2.69 ? 1.19 ?g?dm-3) or an untreated meadow (average 2.25 ? 1.39 ?g?dm-3). Iodine therefore probably originated from the urine and feces of grazed cattle. This thesis contributes to the total knowledge of iodine, particularly to the part concerning determination of iodine in the hydrosphere.

The thesis entitled “Design and Development of Synthetic Methods using Metal-mediated and Metal-free Redox Reactions: Novel C-H Activations, Reductions and Oxidative Transformations” is presented in 4 chapters Chapter 1; Iodine catalyzed amination of benzoxazoles: efficient metal free route to 2-aminobenzoxazoles under mild conditions. The Chapter 1 of this thesis describes iodine catalyzed C-H activation of benzoxazole with primary and secondary amines to form oxidative aminated products. Selective C-H oxidation is a frontline area of modern chemical research as it offers the opportunities to new avenues and more direct synthetic strategies for the synthesis of complex organic molecules.1 In this context, transition metals such as palladium copper, nickel etc, are used extensively for the functional group directed C-H activation, and thus provides new, rapid, low-cost, and environmentally benign protocols for the construction of new chemical bonds.2 During the past two decades iodine and hypervalent iodine have been focus of great attention as they provide mild, chemoselective and environmentally benign strategies in contrast to toxic metal oxidants.3 In this chapter, a facile metal-free route of oxidative amination of benzoxazole with secondary or primary amines in the presence of catalytic amount of iodine (5 mol%) in aq tert-butyl hydroperoxide (1equiv) and AcOH (1.1 equiv) at ambient temperature, under the solvent-free reaction condition is presented. This user-friendly method to form C-N bonds produces tert-butanol and water as the by-products, which are environmentally benign. A wide range of benzoxazole derivatives containing electron-donating and electron-withdrawing groups were coupled with both primary and secondary amines (Scheme 1). Application of this methodology is demonstrated by synthesizing therapeutically active benzoxazoles by reacting 5-chloro-7-methylbenzoxazole with N-methylpiperazine and N-ethylhomopiperazine to obtain corresponding N-aminatedbenzaxozoles, which exhibit antidiarrhetic activity (Scheme 2).4 Scheme 2 Chapter 2: NIS catalyzed reactions. amidation of acetophenones and oxidative amination of propiophenones Chapter 2 is divided in to 2 parts. Part 1 describes the synthesis of α-ketoamides by using acetophenone and secondary amine in the presence of N-iodosuccinamide and TBHP in acetonitrile at room temperature, whereas Part 2 reveals the synthesis of 2-aminoketones by reacting aryl alkyl ketones and suitable secondary amine in the presence of NIS and TBHP. Part 1: Oxidative amidation, synthesis of α-ketoamide: Alpha α-ketoamides are important intermediates in organic synthesis that are present in a variety of natural products, and pharmaceutically active compounds. Herein, a mild and efficient conversion of acetophenones to α-ketoamide is documented by using aq.TBHP and N-iodosuccinamide (NIS) as a catalyst, at ambient temperature. This amidation reaction was found to be versatile as several aetophenone derivitives containing electron-withdrawing and electron-donating substituents underwent a facile amidation. It was also found that acetyl derivatives of heterocylic compounds could be easily converted to their corresponding ketoamides (few examples are shown in Scheme 3).5 Scheme3 Part 2 of Chapter 2 narrates a novel amination of propiophenone and its derivatives catalysed by NIS in the presence of TBHP to furnish their corresponding 2-aminoketone derivatives (Scheme 4). These derivatives are ubiquitous scaffolds that are present in a wide variety of therapeutic agents. Some of these compounds are used in the treatment of depression, smoking cessation, as monoamine uptake inhibitors, rugs for cancer. They are photoinitiators, precursors to β-aminoalcohols, such as pseudoephedrine analogues. 2-Aminoacetophenone analogues are also important intermediates for the formation of several heterocyclic compounds and are active moieties in several important drugs such as ifenprodil, Scheme 4. Chapter 3: Efficient oxidation of primary azides to nitriles This Chapter is divided in to 2 parts, which presents the oxidation of primary azides to their corresponding nitriles. Part 1: An Efficient oxidation of primary azides catalyzed by copper iodide: a convenient method for the synthesis of nitriles In Part 1, an efficient oxidation of primary azides catalyzed by copper iodide to their corresponding nitriles is reported. Herein, the oxidation of primary azide to nitrile is performed using catalytic amount of copper iodide, and aq TBHP in water at 100 ° C. This methodology is compatible with a wide range of primary benzylic azides that contain electron-donating and electron-withdrawing functional groups. The oxidation was found to be selective and a number of oxidizable functional groups were well-tolerated during the reaction conditions (few examples are shown in Scheme 5).6 Scheme 6 Furthermore, oxidation of secondary azides furnished the corresponding ketones in excellent yields (Scheme 6).6 In the Part 2 of Chapter 3, a non-metal catalysed oxidation of primary azides to nitriles at ambient temperature is reported. This part reveals the oxidation of primary azides to nitriles by employing catalytic amounts of KI (25 mol%), DABCO (25 mol%) and aq. TBHP (3 equiv., 70% solution in water). This reaction provides a good selectivity, as double and triple bonds were not oxidized under the reaction conditions. Additionally, chemoselective oxidation of benzylicazides against aliphatic azides increases the potential application of the present method (Scheme 7).7 Chapter 4: Chemoeselective reduction of olefins Part 1: Iron chloride catalysed aerobic reduction of olefins using aqueous hydrazine at ambient temperature Chapter 4 describes the reduction olefins and acetylenes, which is presented in two Parts. Part 1 documents utility of hydrazine (1.5 equiv) for the chemoselective reduction of nonpolarised carbon-carbon bond using iron catalysts. In this part, a chemoselective reduction of alkenes and alkynes in the presence of a variety of reducible functional groups is demonstrated (Scheme 8). The highlight of the present method is that the reduction proceeds well at room temperature and requires only 1.5 equiv of hydrazine hydrate. The olefin reduction by hydrazine depends upon the controlled release of diimide during the reduction. Generally, metal catalyzed reduction of olefins employ a large excess of hydrazine (10-20 equiv), which might be attributed to uncontrolled release of diimide during the reduction.8 Scheme 8 Part 2: Guanidine catalyzed aerobic reduction: a selective aerobic hydrogenation of olefins using aqueous hydrazine In Chapter 4, part 2, organocatalytic generation of diimide and its utility to reduce the double bonds is presented. Generation of diimide in situ by using organo catalysts and its use for the reduction of carbon-carbon double bond is one of the interesting topics in organic chemistry. It has been shown in this part of the thesis that the reduction of olefin at room temperature can be efficiently performed by using 10 mol% of guanidine nitrate, 2 equiv of aqueous hydrazine in oxygen atmosphere. This method tolerates a variety of reducible functional groups such as nitro, azido, and bromo and protective groups such as methyl ethers, benzyl ethers, and Cbz groups. It is also shown that terminal olefin can be selectively reduced in the presence of internal olefin (Scheme 9). Unlike other methods that employ diimide strategy, the present method is shown to be efficient in reducing substrates those contain internal double bonds such as cinnamyl alcohol and its derivatives

Niniejsza rozprawa doktorska została poświęcona tematyce poszukiwania układów elektrokatalitycznych zdolnych do szybkiego przeniesienia elektronu w parze redoks jod/jodki i ich wykorzystania do przygotowania elektrolitów redoks zdolnych do szybkiej propagacji ładunku, co ma niezwykle istotne znaczenie w funkcjonowaniu barwnikowych sensybilizowanych ogniw słonecznych (DSSC), baterii przepływowych (RFB) czy superkondensatorów hybrydowych. Przedstawiona praca ma układ klasyczny, współtworzony przez część literaturową i eksperymentalną. Rozpoczyna się ona od ogólnej charakterystyki elektrochemicznej jodu w rozworach wodnych i organicznych. Następnie porusza tematykę DSSC, gdzie omówiono poszczególne komponenty ogniwa, w tym przede wszystkim elektrolity redoks zawierające jako mediator parę redoks jod/jodki. Energia elektryczna wytwarzana przez alternatywne źródła energii (w tym DSSC) może być magazynowana poprzez jej konwersję w inną formę energii, np. w energię chemiczną – co możliwe jest np. dzięki RFB lub bezpośrednio jako ładunki elektryczne, do czego wykorzystywane są superkondensatory. W kolejnych dwóch rozdziałach pracy skupiono się więc na obu tych technologiach. Wskazano główne cechy różniące RFB od tradycyjnych baterii, ich główne wady i zalety oraz typowy podział i przykłady ogniw, w których jako katolit wykorzystano parę redoks jod/jodki. Z kolei tematyka kondensatorów elektrochemicznych obejmowała szczegółową charakterystykę kondensatorów warstwy podwójnej (EDL), pseudokondensatorów oraz kondensatorów hybrydowych, w tym ich szczególny rodzaj obejmujący kondensatory hybrydowe z aktywnym elektrochemicznie elektrolitem (znane pod nazwą REHES, ang. redox electrolyte-aided hybrid energy storage), najczęściej opartym o jodki metali alkalicznych, które dzięki odwracalnym procesom redoks jonów Ina granicy faz elektroda dodatnia/elektrolit z wytworzeniem jodu i polijodków pozwalają na zwiększoną zdolność do magazynowania ładunku w tego typu urządzeniach. W pracy zwrócono również szczególną uwagę na kwestie podstawowe związane z mechanizmem przeniesienia ładunku w cienkich warstwach elektrodowych oraz materiałach stałych i półstałych typu ang. bulk posiadających mieszane stopnie utlenienia. W celu rozszerzenia tych zagadnień przedstawiono także szczegółową charakterystykę elektrochemii ciała stałego bez kontaktu z zewnętrzną fazą elektrolitu podstawowego oraz wskazano na możliwości diagnostyczne i analityczne pomiarów elektrochemicznych ciał stałych przy wykorzystaniu mikroelektrod. W kolejnym rozdziale zajęto się kwestią zwiększenia stałej szybkości reakcji poprzez wprowadzenie do układu katalizatora, co umożliwia konwersję energii w sposób maksymalnie wydajny, odwracalny i opłacalny. Poruszono również temat szczególnego rodzaju elektrokatalizy, a więc mediacji elektrokatalitycznej. Natomiast ostatni rozdział części teoretycznej uwzględnia opis stosowanych technik badawczych. Badania opisane w części eksperymentalnej podzielone zostały na cztery główne rozdziały. W pierwszym z nich w celu zwiększenia szybkości propagacji ładunku zaproponowano wykorzystanie nanocząstek Pt rozdrobnionych „trójwymiarowo” w półstałej cieczy jonowej zawierającej parę redoks jod/jodki. Pozwoliło to na indukowanie etapu chemicznego, a więc rozerwania wiązania jod-jod w cząsteczce I3 - odpowiedzialnego za ograniczenie przeniesienia elektronu w układzie. Powyższa koncepcja została zademonstrowana zarówno w pomiarach diagnostycznych z wykorzystaniem elektrochemii ciała stałego jak i pomiarach praktycznych w DSSC. Aby ograniczyć koszty związane z zastosowaniem nanocząstek Pt w kolejnym rozdziale pracy zaproponowano zastąpienie ich przez nanocząstki Pd przy wykorzystaniu tego samego elektrolitu redoks opartego o ciecz jonową. W ich przypadku do obliczeń efektywnego współczynnika dyfuzji wykorzystano trzy różne metody elektrochemiczne oparte na technikach: woltamperometrii cyklicznej, chronoamperometrii i chronokulometrii. Uprzednio, zarówno modyfikatory oparte na nanocząstkach Pt, jak i Pd zostały poddane charakterystyce fizykochemicznej (SEM, TEM, EDX, potencjał zeta) i rozszerzonej charakterystyce elektrochemicznej. Dalszą część pracy badawczej poświęcono wprowadzeniu opisanych modyfikatorów do elektrolitu na bazie rozpuszczalnika organicznego (acetonitrylu) o możliwie jak najprostszym składzie. Takie podejście miało na celu porównanie mechanizmu propagacji ładunku w dwóch różnych roztworach, charakteryzujących się odmienną lepkością. Jako alternatywę dla nanocząstek metali szlachetnych zaproponowano również wykorzystanie szeroko opisywanych w literaturze polimerów przewodzących (a dokładniej poli(3,4-etyleno-1,4-dioksytiofenu), PEDOT) i materiałów węglowych (węgla aktywnego). Ostatnia część rozprawy doktorskiej dotyczyła mechanizmu działania kondensatorów hybrydowych zawierających parę redoks jod/jodki świeżo po zmontowaniu układu, jak i po przeprowadzeniu testów stabilności. Do konstrukcji tych urządzeń wykorzystano dwa rodzaje materiałów elektrodowych charakteryzujących się zupełnie odmienną morfologią: węgiel aktywny i PEDOT, które scharakteryzowano przy pomocy najnowszych technik fizykochemicznych. Analiza procesów zachodzących w trakcie testów przyspieszonego starzenia wykonanych dla skonstruowanych w ten sposób kondensatorów pozwoliła na zdiagnozowanie przyczyn różnic w szybkości ich samorozładowania będącego wynikiem reakcji pasożytniczych zachodzących przede wszystkim na elektrodzie ujemnej.
Electrochemical systems characterized by fast (reversible) charge transfer have a practical significance, particularly in electrochemical storage and conversion systems such as dye-sensitized solar cells (DSSC), redox flow batteries (RFB) and redox electrolyte-aided hybrid energy storage (REHES)). Moreover, development of above-mentioned, alternative energy technologies have crucial importance of protecting the environment. One of the most commonly used redox couples responsible for efficient electron transfer in energy storage and conversion systems is the iodine/iodide. Therefore, the first Chapter of this doctoral dissertation is focused on the general electrochemical properties of iodine and its electrochemical characterization in aqueous and organic solutions. The next part is dedicated to DSSC, where its individual components are discussed and particular attention is paid to the redox electrolytes containing iodine/iodide redox mediator. In addition, it should be emphasized that the energy generated by alternative energy sources, including DSSC, can be stored by converting it into chemical energy for example by using RFB or can be directly stored as electrical charge in electrochemical capacitors. Consequently, the next two Chapters of my dissertation focus on these two energy storage technologies. The main differences between RFB and traditional batteries and the resulting pros and cons of these devices are indicated. Farther the typical classification of flow batteries and the examples of the cells where the iodine/iodide redox couple is used as the catholyte are presented. The next part of the dissertation is devoted to the electrochemical capacitors. These include the detailed characteristics of double-layer-type systems, pseudocapacitors and hybrid capacitors, i.e. combining the electrochemical signature of batteries and conventional supercapacitors. A specific class of hybrid capacitors containing electrochemically active electrolyte (widely known as REHES - redox electrolyte-aided hybrid energy storage) is also characterized. These systems are often based on alkali metal iodides and exhibit an increased charge storage capacity as a result of reversible redox reactions of iodide ions occurring at the positive electrode/electrolyte interface. This PhD thesis also does not omit the basic issues related to the mechanism of charge transfer in thin electrode layers, bulk solid and semi-solid materials having mixed oxidation states. In order to submit a more complete study, detailed characterization of solid electrochemistry without contact with the external phase of the supporting electrolyte is also given. Moreover the emphasis is put on the utilization of microelectrodes in electrochemical characterization of solids. The following Chapter is focused on the increment of the reaction rate constant by inserting the catalyst into the system which allows the conversion of energy in the most efficient, reversible and cost-effective way. Next an electrocatalytic mediation as a specific kind of electrocatalysis is also discussed. The theoretical part of this PhD thesis is finished by brief description of the research methods used in the experimental part. The research described in the experimental part has been divided into four main Chapters. In order to enhance charge propagation within the system, firstly the utilization of Pt nanoparticles "three-dimensionally" distributed in a semi-solid ionic liquid containing iodine/iodide redox pair is described. It allows the induction of a chemical stage, breaking of the iodine-iodine bond in the I3 - molecule, which is responsible for limiting electron transfer in the system. The above mentioned concept has been demonstrated in both, diagnostic measurements which utilized solid-state electrochemistry and a practical set-up in a DSSC. Pd nanoparticles, as a cheaper alternative to Pt nanoparticles, are also proposed with the same redox electrolyte based on the ionic liquid to enhance charge transfer within the system. With reference to Pd nanoparticles three different electrochemical methods based on cyclic voltammetry, chronoamperometry and chronoculometry were used to calculate the effective diffusion coefficient and apparent concentration of redox centers. The used modifiers based on Pt and Pd nanoparticles have been subjected to physicochemical (SEM, TEM, EDS, zeta potential) and extended electrochemical characterization). The subsequent part of the research involves introducing the aforementioned modifiers into the electrolyte based on organic solvent (acetonitrile) with the possible simplest composition. The aim of such approach is to compare the mechanism of charge propagation in two different solutions with different viscosities. As an alternative to noble metal nanoparticles, the use of conductive polymers (more specifically poly (3,4-ethylene-1,4-dioxythiophene), PEDOT)) and carbonaceous materials (activated carbon) have also been proposed. The last part of the doctoral dissertation refers to the operation mechanism of hybrid capacitors containing iodine/iodide redox-based electrolyte by addressing their performance changes in time and with a type of stability test used. Two types of electrode materials with different morphology and charge storage mechanism were used in the construction of these devices, i.e. activated carbon and PEDOT. Both of these materials were characterized using different physicochemical techniques. Analysis of processes occurring during potentiostatic accelerating-ageing stability tests allowed to diagnose the causes of differences in the rate of self-discharge as well as to describe the parasitic reactions responsible for high internal leakage by proposing a new mechanism of charge/self-discharge in the halogene-based electrolytes used in supercapacitors.