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Carbon-carbon and carbon-nitrogen bond forming events are essential in chemistry. Although numerous stoichiometric/catalytic methods provided elegant and powerful solutions enabling those processes, the use of scarce/toxic reagents and harsh conditions is still ubiquitous in this field. As a result, extensive research has been conducted in the development of environmentally benign and inexpensive reagents for such transformations, however, general solutions remain a challenge. In this context, one of the focuses of our lab is to enable those processes in a more practical and sustainable fashion by using hypervalent iodine reagents. In this dissertation we demonstrate the synthetic applications of λ3-iodane reagents towards the formation of challenging carbon-carbon and carbon-nitrogen bonds in a complementary way to the methods already reported. Chapter 1 of this dissertation outlines the general electronic structure, geometry, synthesis and reactivity of λ3-iodanes as serves and background regarding these reagents. Chapter 2 highlights the applications of λ3-iodanes to access high-oxidation state transition metals until the year of 2017. This literature review provides detailed information about how λ3-iodanes can be applied to access 1st, 2nd and 3rd row high-oxidation complexes, as well as mechanistic details and synthetic utility of high-valent transition metals. Chapter 3 demonstrates our efforts to generate selective carbon-nitrogen and carbon-carbon products from a high-valent nickel complex. This led to important information of this mechanism adopted by the reaction and how the choice of oxidant can impact 1e- versus 2e- oxidative pathways on “hard” nickel pincer scaffolds. Chapter 4 describes our efforts towards the selective formation of α-C(sp2)-C(sp2) bonds at the α-position of enones via a reductive Iodonium-Claisen rearrangement. We demonstrate the utility of β-pyridinium silyl enol ethers as a platform for direct α-arylation, and how the 2-iodo-aryl-α-arylated enones can be used to access diverse heterocyclic structures. Chapter 5 demonstrates our initial efforts towards the selective C2 or C3 carbon-nitrogen bond formation on indoles. By exposing different indoles to (bis)cationic nitrogen-ligated HVI (N-HVI) reagents we found that selective C2 or C3 C-H indole-pyridinium salts can be formed in good to excellent yield. Although, this project is not finished yet, we anticipate the indole-pyridinium salts generated could serve as platform for accessing diverse piperidines, pyridones and primary amines through straightforward procedures. The combined chapters of this dissertation highlight the applications of λ3-iodanes towards transition metals and emphasize the applications of these reagents to enable challenging C–C and C–N bond formation events. More importantly, this dissertation serves as a guide for future development of the hypervalent iodine field. / Chemistry

<p> Iodine-125 is produced from Xe-124 at McMaster Nuclear Reactor (MNR) for medical applications. Excessive amounts of this isotope in the air of the reactor site can be hazardous especially for the staff members who are continuously working at the reactor building. Therefore there is a critical need to monitor the concentration of iodine released to the air. In the previous iodine monitoring system available at MNR, there were several technical and practical problems. Consequently a new monitoring system was designed to overcome the previous problems and to provide with further facilities for the staff. The system is developed in the LabVIEW1 platform and is easily maintainable. The external data acquisition board LabJack is used to transfer the data to the PC. Briefly, by using radiation monitoring techniques and statistical methods, a computerized embedded system is designed to keep the MNR a safe place for operators and visitors. This thesis examines in detail the design and implementation of the new monitoring system, MASIS.</p> / Thesis / Master of Applied Science (MASc)

Thesis. 1976. Ph.D.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences. / Microfiche copy available in Archives and Science. / Vita. / Bibliography: leaves 235-250. / Ph.D.

The National Aeronautics and Space Administration (NASA) is considering the use of iodine for disinfection of recycled wastewater and potable water in the International Space Station (ISS). Like Chlorine and other halogen compounds, iodine can form disinfection by-products (DBPs) in the presence of organic compounds. Recycled wastewater sources proposed for reuse in the space station include laundry, urine, and humidity condensate. These contain large concentrations of iodine-demanding compounds, including phenol (Barkely et al., 1992). Therefore, the potential for the formation of iodine disinfection by-products (IDBPs) is of concern. Based on the characteristics of the ISS recycled wastewater sources and potable water treatment system, a series of experiments was designed to evaluate the formation of IDBPs under different experimental conditions. Studies were conducted by reacting various concentrations of iodine with phenol at pH 5.5 and 8.0.Iodine concentrations of 10 and 50 mg/L and phenol concentrations of 5 and 50 mg/L were used. Reactions were monitored for up to 32 days for the formation of IDBPs. All reactions were maintained at 20 C in dark. High Performance Liquid Chromatography (HPLC) and Gas Chromatography/Mass Spectrometry (GC/MS) were used for identification and quantitative analysis of phenolic compounds. Spectrophotometry was used to monitor the iodine concentrations. Falvor Profile analysis (FPA) method was used to evaluate the odor characteristics of the phenolic compounds. Reactions of iodine with phenol resulted in the formation of the following by-products: 2-iodophenol, 4-iodophenol, diiodophenols, and 2,4,6-triiodophenol. Most reaction conditions studied resulted in the formation of all or some of the specified iodophenols. The initial mass ratio of iodine to phenol was the major determining factor in the concentrations and types of by-products formed. The IDBPs were formed within one hour after initiation of the reactions. Extended reaction times did not lead to significant increases in the concentration of IDBPs. Under most reaction conditions, mono-subsituted phenols were detected at significantly higher concentrations than di-substituted phenolic compounds; triiodophenol was the major by-product when iodine:phenol mass ratio was 10:1. The greatest number of IDBPs were formed when reaction solutions consisted of 1:1 mass ratio of iodine to phenol. FPA panel indicated the odor threshold concentrations for phenol, 2-iodophenol, and 4-iodophenol were 5 mg/L, less than 1 ug/L, and 1 mg/L respectively. The most common odor descriptions for all these compounds were &quot;chemical&quot;, &quot;phenolic&quot;, and &quot;medicinal&quot;. / Master of Science

The objective of this study was to determine if topical antimicrobials silver sulfadiazine and povidone-iodine ointment increase rates of healing of equine distal limb wounds that heal by second intention. Second, to determine the effect of bandaging with these topical antimicrobials. Six healthy adult horses were used to create thirty-six, 2.5 cm2 standardized full-thickness metacarpal/tarsal skin wounds. Each wound was exposed to a single treatment: 1.0 % silver sulfadiazine cream bandaged (SSD-B), 1.0 % silver sulfadiazine slow release matrix bandaged (SDX-B), 1.0% silver sulfadiazine slow release matrix not bandaged (SDX-NB), povidone-iodine ointment bandaged (PI-B), untreated control bandaged (C-B) and untreated control not bandaged (C-NB) until healing. Wound area, granulation tissue area and perimeter were measured with planimetry software from digital images obtained at each observation. Exuberant granulation tissue was excised when present. The days until healing, rate of healing parameter, rates of contraction and epithelialization were compared among groups using pair-wise analysis of least square means. The healing parameters and mean days to healing did not statistically differ between groups. Analysis of percent wound contraction and rate of epithelialization between groups was similar. Mean number of days to healing ranged from 83 (PI-B and C-B) to101 (SSD-B). All bandaged wounds produced exuberant granulation tissue requiring excision compared to none of the unbandaged. The identified rates of epithelialization and wound contraction found insignificant differences between antimicrobial treated versus untreated wounds. Similarly, rates of epithelialization and wound contraction found insignificant differences between bandaged versus unbandaged wounds. Topical povidone-iodine and silver sulfadiazine did not increase rates of healing under bandage. The 1.0% silver sulfadiazine slow release matrix not bandaged (SDX-NB) adhered well to dry wounds. Silver sulfadiazine slow-release matrix provides does not impede wound healing and provides good adherence to dry wounds not amenable to bandaging. / Master of Science

Huge amounts of anthropogenic 129I have been and still are released to the environment through liquid and gaseous discharges from the nuclear fuel reprocessing facilities worldwide and in particular the ones in Europe. Most of this 129I signal has been accumulated in the marine environment which plays a major role in the iodine natural pool.  In this thesis, an overview of available 129I concentrations in waters of the oceans and marginal seas together with new data about 129I and 127I spatial distribution in surface seawater along a transect between the North Sea and the northeastern Atlantic Ocean are presented. After comprehensive chemical separation, the concentrations of iodine isotopes (127I and 129I) and their species (iodide and iodate) were analysed using accelerator mass spectrometry and inductively-coupled plasma mass spectrometry. The results show that, generally, changes in the 127I and 127I-/127IO3- are comparable to data from other marine waters which are related to natural distribution patterns. A considerable variation of 129I along the transect is observed with the highest values occurring in the eastern English Channel and relatively low values obtained in the northeastern Atlantic Ocean. Inventory estimations of 129I in the North Sea and the English Channel are 147 kg and 78 kg, respectively, where more than 90% resides in the Southern Bight and the eastern English Channel. Iodate is the dominant iodine species for both 127I and 129I in most seawater samples from the North Sea to the Atlantic Ocean. 129I species variability suggests a slow process of 129I- oxidation in the open sea. It takes at least 10 years for the 129I-/129IO3- pair to reach their natural equilibrium as the water is transported from the English Channel. The results suggest a main transport of 129I from the western English Channel via the Biscay Bay into the northeastern Atlantic Ocean. Further, high 129I/127I and distinctive 129I-/129IO3- values south of 40°N indicate possible contribution of 129I through Mediterranean Outflow Water. The environmental radioactive impact of 129I and possible applications in ecosystem studies are also discussed.

A nutrição de iodo de uma população é avaliada por indicadores: a iodação do sal, excreção urinária de iodo e volume tiroidiano. A iodação do sal é eficiente no combate às doenças decorrentes da deficiência de iodo, sendo empregada em todo território nacional desde 1995 e o estado de São Paulo é considerado uma área iodo-suficiente. Para avaliar esta ingesta de iodo, foram selecionados aleatoriamente 964 escolares entre 6 a 14 anos, de seis regiões do Estado. Foram avaliados sob o ponto de vista ecográfico da tiróide, 484 meninas e 480 meninos. Os volumes da glândula tiróide elevaram-se progressivamente com a idade, guardando correlação positiva e significativa com a superfície corporal. Cerca de 2,9% dos escolares apresentava bócio. Outras anormalidades encontradas foram hemiagenesia (0,5%), nódulos (0,2%), cistos (0,7%) e hipoecogenicidade (11,7%). Notamos excessiva excreção urinária de iodo nesta população, com valores superiores a 300ug Iodo/L em 76,8% das amostras. As amostras de sal doméstico apresentavam valores entre 34,0 e 68,3mg Iodo/Kg de sal. Concluímos que a população de escolares estudados no estado de São Paulo apresenta excessiva ingestão diária de iodo, a qual, extrapolada para população em geral poderá induzir várias alterações da função tiroidiana, como hipertiroidismo subclínico (em idosos) e tiroidite crônica auto-imune na população adulta. / The salt iodization is efficient to prevent iodine deficient disorders and began in all of Brazil in 1995 and the state of São Paulo is considered an iodine sufficient area. To evaluate the iodine nutrition, 964 schoolchildren, aged between 6 and 14 years old (484 girls, 480 boys) were examined by ultrasonographic studies. There was a progressive increase of the thyroid volume with aging with a positive and significant correlation with the body surface area. The presence of enlarged thyroid gland was rarely seen, being present in only 2.9% of the studied cohort. A few thyroid gland abnormalities were noticed such as hemiagenesia (0.5%), nodules (0.2%), cysts (0.7%) and hypoechogenicity (11,7%). It was clearly demonstrated that the urinary excretion of iodine was elevated being above 300ug Iodine/L in 76,8% of the schoolchildren examined. Assays for the iodine concentration in domestic salt samples revealed values between 34.0 and 68.3 mgI/kg of salt. We conclude that the schoolchildren population of the State of São Paulo may be under an excessive daily ingestion of iodine. This may induce, if extrapolated to the general population, subclinical hyperthyroidism in the elderly and possibly an increment in the prevalence of cronic autoimmune thyroiditis.

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The main goal of my diploma thesis was to review the amount of iodine in meat of foodanimals. This diploma thesis brings current information about the iodine content in meat in The Czech Republic. The samples were extracted during the years 2004 to 2007. On the whole 63 samples, in which the content of iodine was set by Sandell - Kollthof method, were taken. The average content of iodine in meat was as follows : rabbits 19,2; domestic pigs 16,17; market pigs 16,96; wild pigs 57,72 and deer 38,31 &#61549;g I &#61655; kg-1 wet matter. Regional and seasonal differences were proved.