Orientador: Luis Roberto Marcondes Martins / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-27T11:02:43Z (GMT). No. of bitstreams: 1 Stape_ThiagoHenriqueScarabello_D.pdf: 2806642 bytes, checksum: ff8fdbed5d394599068a4bc1d64d36c2 (MD5) Previous issue date: 2015 / Resumo: Essa tese avaliou um novo protocolo adesivo, que consiste no pré-tratamento dentinário com dimetilsulfóxido (DMSO) 50%, com o intuito de otimizar a durabilidade de interfaces adesivas produzidas pelos mecanismos de união convencional e autocondicionante envolvendo o substrato dentinário. Para isso, foram realizados dois estudos independentes para avaliar: (i) o efeito do uso do dimetilsufóxido (DMSO) na resistência de união imediata e na exposição de matriz colágena decorrente da hibridização dentinária na interface adesiva; e (ii) para avaliar o efeito do protocolo proposto na conversão monomérica na camada híbrida e na resistência de união após envelhecimento. Terceiros molares hígidos foram coletados e limpos, a face oclusal foi seccionada, expondo uma superfície dentinária de profundidade média, que foi saturada com uma solução aquosa de DMSO 50% (pH 8.2) após o condicionamento ácido para o sistema convencional de três passos (Adper Scothbond Multi-Purpose: 3M ESPE: SBMP) e previamente a aplicação do sistema autocondicionante de dois passos (Clearfil SE Bond: Kuraray; CF) no substrato mineralizado. Nos grupos controles, as amostras não foram tratadas com DMSO. Os segmentos restaurados com resina composta foram seccionados e submetidos ao ensaio de microtração após 24 h à 0,5 mm/min até a fratura (n=12) e no segundo estudo (n=10), após 1 ano e 2 anos. Foi realizada Two-way ANOVA para análise dos dados imediatos e no segundo estudo foi utilizada ANOVA medidas repetidas (proc mixed), ambos seguidos pelo Teste de Tukey (?=0.05). Foi realizado a análise histomorfométrica (n=12) para avaliação da extensão de matriz colágena exposta na interface adesiva por meio de microscopia ótica e coloração de Tricrômica de Masson após 24 h. Esses dados foram submetidos a Two-way ANOVA, seguido do Teste de Tukey (?=0.05). O grau de conversão monomérica (DC) na camada híbrida foi avaliado por espectroscopia micro-raman após 24 h (n=10), sendo submetidos a One-way ANOVA e Teste de Tukey (?=0.05). A interação entre protocolo adesivo e sistema adesivo influenciou significativamente a extensão de matriz colágena exposta (p<0,0001) e resistência de união imediata (p=0,0091). O protocolo adesivo com DMSO reduziu significativamente o grau de exposição de matriz colágena exposta (SBMP: 85,3% e CF: 61,5%), melhorando a qualidade da hibridização dentinária para ambos sistemas adesivos. Não houve influência negativa do DMSO na conversão monomérica do SBMP (p=0.892); já para o CF, houve aumento na conversão monomérica (p=0.033). O pré-tratamento com DMSO aumentou a resistência de união imediata do SBMP (p<0.0001). Considerando as amostras não tratadas, houve uma redução significativa (SBMP: 45,6% e CF: 36,8%) na resistência de união do SBMP (p<0.0001) e CF (p<0.0001) após dois anos de envelhecimento. Independentemente do tipo de adesivo, não houve diferença estatística na resistência de união entre valores imediatos e após 2 dois anos quando o DMSO foi empregado (p>0,05). A análise dos padrões de falha evidenciou uma tendência na redução no número de falhas adesivas após dois anos para as amostras tratadas com DMSO. Portanto, o protocolo adesivo proposto utilizando o DMSO é uma abordagem promissora para reduzir degradação da interface adesiva para os adesivos convencional e autocondicionante testados / Abstract: This work highlights a new bonding concept using 50% dimethyl sulfoxide (DMSO) as a dentin pre-treatment to optimize resin-dentin bonding for both etch-and rinse and self-etch adhesive systems after long-term aging. Two independent studies were performed: (i) to evaluate the effect of dimethyl sulfoxide wet-bonding technique on resin infiltration depths at the bonded interface and dentin bond strength; and (ii) to examine the effect of dentin pre-treatment with DMSO on the degree of conversion and dentin bond strength after long-term aging. Flat dentin surfaces derived from extracted sound human third molars were saturated with 50% DMSO (pH 8.2) after acid etching for a water-based etch-and-rinse adhesive system (Adper Scothbond Multi-Purpose: 3M ESPE; SBMP), and before acid primer application for a 10-MDP self-etch adhesive (Clearfil SE Bond: Kuraray; CF). In control groups, specimens were not treated with DMSO. The restored tooth segments were sectioned and submitted to microtensile bond strength test at 24 h (n=12), 1 year (n=10) and 2 years (n=10) at 0.5 mm/min until specimen fracture. One slab per tooth (n=12) was stained by Masson Trichrome and the extent of exposed collagen matrix at the bonded interface was evaluated using optical microscopy and a histomorphometric software at 24 h. Statistical analysis of the extension of collagen exposure was performed by two-way ANOVA followed by Tukey Test (?=0.05). The degree of conversion (DC) was measured inside the hybrid layer by micro-raman spectroscopy (n=10) at 24 h. DC statistical analysis was performed by One-way ANOVA and Tukey Test (?=0.05). Immediate microtesnile data was statistically analyzed Two-way ANOVA and aged data was analyzed by repeated measurres ANOVA (proc mixed). Post hoc multiple comparisons were performed by Tukey Test (?=0.05). The interaction between "dentin pre-treatment" and "adhesive system" significantly influence the extent of exposed collagen matrix (p<0.0001) and dentin bond strength (p=0.0091). The adhesive protocol with DMSO significantly reduced the extent of exposed collagen matrix (SBMP: 85.3% and CF: 61.5%), improving the quality of dentin hybridization for both adhesive systems. There was no negative influence of DMSO in monomer conversion for SBMP (p=0.892); nevertheless, there was an increase in monomer conversion (p=0.033) for CF. Dentin pretreatment with DMSO increased the immediate bond strength of SBMP (p<0.0001). Considering the untreated samples, there was a significant reduction (SBMP: 45.6% and CF: 36.8%) on the bond strength of SBMP (p<0.0001) and CF (p<0.0001) after two years of aging. Regardless of adhesive type, no significant reduction in bond strength at two years for DMSO-treated samples was observed. Fracture pattern analysis showed a tendency toward reduction in the number of adhesive failures when the DMSO-wet bonding was performed. Therefore, DMSO-wet bonding is a promising approach to reduce resin-dentin bond degradation of etch-and-rinse and self-etch adhesives / Doutorado / Dentística / Doutor em Clínica Odontológica

No / Transmembrane pore formation is central to many biological processes such as ion transport, cell fusion, and viral infection. Furthermore, pore formation in the ceramide bilayers of the stratum corneum may be an important mechanism by which penetration enhancers such as dimethylsulfoxide (DMSO) weaken the barrier function of the skin. We have used the potential of mean constraint force (PMCF) method to calculate the free energy of pore formation in ceramide bilayers in both the innate gel phase and in the DMSO-induced fluidized state. Our simulations show that the fluid phase bilayers form archetypal water-filled hydrophilic pores similar to those observed in phospholipid bilayers. In contrast, the rigid gel-phase bilayers develop hydrophobic pores. At the relatively small pore diameters studied here, the hydrophobic pores are empty rather than filled with bulk water, suggesting that they do not compromise the barrier function of ceramide membranes. A phenomenological analysis suggests that these vapor pores are stable, below a critical radius, because the penalty of creating water-vapor and tail-vapor interfaces is lower than that of directly exposing the strongly hydrophobic tails to water. The PMCF free energy profile of the vapor pore supports this analysis. The simulations indicate that high DMSO concentrations drastically impair the barrier function of the skin by strongly reducing the free energy required for pore opening. / EPSRC

DMSO (dimethyl sulfoxide) is a liquid with a high boiling point (189 oC) that has been extensively utilized in various industries owing to its ability to dissolve various organic and inorganic compounds. DMSO is increasingly being adopted as a detergent or a photo-resistant stripping solvent in manufacturing semiconductors and liquid crystal displays (LCD). Therefore, DMSO is now a major component of wastewater. The biological treatment of DMSO-containing wastewater generates noxious DMS (dimethyl sulfide) and other compounds that may cause odor problems. Also having a high water solubility and a moderate boiling point (110 oC), tetrafluoro propanol (TFP) has been extensively applied in the manufacture of CD-R and DVD-R, due to its ability to dissolve organic dyes. The spin coating process produces a large amount of wastewater containing TFP. No reports have been written on the biodegradability of TFP to the authors¡¦ knowledge. Additionally, HMDS (hexamethyldisilazane) has been extensively used in life science microscopy and material science. For instance, the semiconductor industry employs HMDS to promote the adhesion of photo-resistant material to oxide(s). HMDS is classified as a carcinogen, and has an ammonia odor. Condensing incinerators have been found to be unsuitable for treating HMDS-containing waste gases, because of the formation of silicon dioxide, which blocks porous adsorbents. Biological treatment also appears to be unpromising due to its low water solubility and limited biodegradability. This investigation evaluates the feasibility, effectiveness and oxidation characteristics of aqueous DMSO, TFP and gaseous HMDS (hexamethyldisilazane) by UV/O3 processes. A reactor made entirely of acrylic plastic with an effective volume of 10 L was employed for the reactions. The tested VOCs concentrations were adjusted to 400¡V890mg/L and 772¡V887 mg/L for DMSO and TFP, respectively, and the gas (ozone-enriched air) flow rate was controlled at 3L/min. The effects of various solution pH values (acidic, alkaline, uncontrolled), solution temperatures (26 oC, 37 oC, 48 oC and 60 oC), and UV wavelengths (254 nm and 185+254 nm) on the removal of tested VOCs were studied . Additionally, the operation costs of treating DMSO and TFP by UV/O3 were estimated. Experimental results demonstrate that acidic conditions (pH = 3.6) favored the degradation of DMSO, and that the removal efficiency could reach 95% at a volumetric UV intensity P/V of 2.25 W/L and a reaction time of 120 min. However, alkaline conditions (pH = 9.5) favored the decomposition of TFP, with the removal efficiency reaching 95% at P/V = 2.5 W/L and a reaction time of 60 min. Both DMSO and TFP exhibited zero-order degradation kinetics when sufficient ozone was supplied. Raising the oxidation temperature did not increase the UV/O3 oxidation of TFP in the tested concentration and temperature ranges. Operation costs of the UV/O3 per unit volume of wastewater with DMSO or TFP are comparable to those of the methods described in the literature. For the gaseous HMDS oxidation, two batch reactors with effective volumes of 1.2 and 5.8 L were used employed with the decomposition occurred under UV (185+254 nm) irradiation and UV (254 nm)/O3 processes. Tests were performed with initial HMDS concentrations of 32¡V41mg/m3 under various initial ozone dosages (O3 (mg)/HMDS (mg) =1¡V5), atmospheres (N2, O2, and air), temperatures (28 oC, 46 oC, 65 oC and 80 oC), relative humilities (20%, 50%, 65% and 99%) and volumetric UV power inputs (0.87 W/L, 1.74 W/L, 4.07 W/L and 8.16 W/L) to assess their effects on the HMDS degradation rate. Results of this study demonstrate that the decomposition rates for the UV (185+254 nm) irradiation exceeded those for the UV (254 nm)/O3 process for all conditions. UV (185+254 nm) decompositions of HMDS displayed apparent first-order kinetics. A process with irradiation of UV (185+254 nm) to HMDS in air saturated with water at temperatures of 46¡V80 oC favors the HMDS degradation. With the above conditions and a P/V of around 8 W/L, k≈ 0.20 s−1, and over 90% of the initial HMDS was degraded in a time of 12s. The main mechanisms for the HMDS in wet air streams irradiated with UV (185+254 nm) were found to be caused by OH free radical oxidation produced from photolysis of water or O (1D) produced from photolysis of oxygen. Economic evaluation factors of UV (185+254 nm) and UV (254 nm)/O3 processes at various UV power inputs were also estimated.

Made available in DSpace on 2015-12-06T23:01:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2001 / O presente estudo teve como objetivo verificar o estresse oxidativo causado a culturas de queratinocitos atraves de sua exposicao a privacao de glicose e a hipoxia, com e sem o uso de um antioxidante, o Dimetil Sulfoxido (DMSO), avaliado atraves da dosagem do malonaldeido (MDA). O material e metodo constituiu-se de tres experimentos. No primeiro deles, 12 garrafas de cultura de queratinocitos foram preparadas ate atingir-se a confluencia desejada e divididas em quatro grupos (com e sem uso de DIVISO, com e sem hipoxia). Foram colhidas amostras do meio de cultura para dosagem do malonaldeido em diferentes fases do experimento: a) pre-experimento, b) 24 horas apos o inicio da privacao de glicose (antes da provocacao de hipoxia), c) 24 horas apos o inicio da privacao de glicose e imediatamente depois da provocacao de hipoxia, d) 48 horas apos a privacao de glicose (24 horas apos a hipoxia). O Experimento 2 constituiu-se das 12 garrafas do final do primeiro experimento e outras 12 garrafas que foram utilizadas como controle, sendo que foi colhido o material celular das 24 garrafas e realizada dosagem do MDA no homogeneizado celular de cada garrafa. O Experimento 3 foi realizado com 80 garrafas divididas em 10 grupos (meio de cultura com e sem glicose, uso ou nao de DIVISO, realizacao de hipoxia ou nao, alem das associacoes entre esses fatores), das quais foi colhido e homogeneizado o material celular para dosagem do MDA. A analise estatistica realizada com os resultados dos tres experimentos mostrou que o DIVISO foi eficiente na reducao do estresse oxidativo de culturas de queratinocitos, causado pela privacao de glicose e hipoxia, avaliado pelos valores de MDA comparando-se aos grupos controle / BV UNIFESP: Teses e dissertações

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Platelet-rich plasma (PRP) is defined as a plasma volume with a higher platelet count than that of whole blood. PRP has been widely used for treatment of different lesions, both in human and in veterinary medicine. The aim of this study was to search for an effective method of storing equine PRP, without loss of viability. Blood (500 ml) was collected from 8 clinically healthy ponies, where 100 ml were used to prepare PRP; 2 ml were used to determine platelet count and mean platelet volume (MPV). Whole blood was centrifuged at 1000 rpm for 10 minutes to obtain plasma. The plasma obtained was centrifuged again at 1400rpm for 10 minutes to obtain 10 ml of PRP. PRP was divided into 3 samples of 2 ml, one being considered the fresh sample and the other 2 were frozen. Platelet count, determination of MPV and morphological evaluation were performed on the fresh sample. Morphologic evaluation consisted of counting 200 platelets under light-microscopy and their classification in inactive (discoid), activated (with pseudopodia) or uncertain state (who lost the discoid form but showed no pseudopodia). The samples to be cryopreserved were stored in a freezer at -80 ° C for 14 days, containing 6% dimethyl sulfoxide (DMSO) as a cryoprotectant or without any addition of cryoprotectants. After this period, samples were thawed and submitted to the same analysis of the fresh sample. The fresh and DMSO frozen samples showed no difference in the total number of platelets, activated platelets and MPV (617.9 ± 65.5 x103/μL, 5.3 ± 0.06 fL, 9.6%) However, samples frozen without DMSO showed fewer platelets (519.6 ± 66 x103/μL), higher MPV (5.71 ± 0.08 fL) and a higher percentage of activated platelets (13.87%). 6% DMSO proved be an effective cryoprotectant in storing equine PRP at -80°C for 14 days. / O plasma rico em plaquetas (PRP) é definido como plasma com quantidade de plaquetas três vezes superior ou mais à do sangue total. O PRP vem sendo largamente utilizado no tratamento de diferentes lesões, tanto na medicina humana quanto na medicina veterinária. O objetivo deste estudo foi buscar um método eficaz de armazenar o PRP eqüino, sem perda significativa de sua viabilidade. Foram coletados 500 ml de sangue de oito pôneis clinicamente saudáveis, dos quais 100 ml foram utilizados para o preparo do PRP e 2 ml foram enviados à análise laboratorial, para contagem de plaquetas e determinação do volume plaquetário médio (VPM). O sangue total passou por uma primeira centrifugação, de 1000rpm (224g) por 10 minutos para obtenção do plasma. O plasma obtido foi novamente centrifugado, a 1400rpm (440g) por mais 10 minutos para obtenção de 10 ml de PRP. O PRP foi dividido em três amostras de 2 ml, sendo uma considerada a amostra fresca e as outras duas destinadas à criopreservação. A amostra fresca foi enviada ao laboratório para contagem plaquetária, determinação do VPM e avaliação morfológica. A avaliação morfológica consistiu na contagem de 200 plaquetas, sob microscopia óptica e na classificação quanto à sua forma: em inativas (discóides), ativadas (com emissão de pseudópodes) ou em estado incerto (que perderam a forma discóide, mas não apresentavam pseudópodes). As amostras destinadas à criopreservação foram armazenadas em freezer, a -80°C, durante 14 dias, contendo 6% de dimetil sulfóxido (DMSO) como crioprotetor ou sem adição de crioprotetor. Após este período, as amostras foram descongeladas e submetidas às mesmas análises laboratoriais da amostra fresca. As amostras frescas e congeladas com DMSO não apresentaram diferença quanto ao número total de plaquetas, VPM e plaquetas ativadas (617,9 ± 65,5 x103/μL; 5,3±0,06fL; 9,6%) (p>0,05). Entretanto, as amostras sem DMSO apresentaram um número menor de plaquetas (519,6 ± 66 x103/μL), maior VPM (5,71±0,08fL) e maior percentagem de plaquetas ativadas (13,87%) (p<0,05). O DMSO 6% se mostrou um crioprotetor eficaz no armazenamento do PRP eqüino a -80°C por 14 dias.

No description available.

Dimethylsulphoniopropionate (DMSP) and dimethylsulphoxide (DMSO) (collectively DMSP/O) are produced by marine algae, including symbiotic algae within corals. These sulphur compounds are important not only in sulphur cycle dynamics but also in potentially mediating atmospheric conditions, alleviating the effects of climate change and contributing to reef health. Most research has focused on the production of DMSP and its major degradation product, the climatically active gas, dimethylsulphide (DMS) by Acropora corals in the Great Barrier Reef. However, mechanisms for the production and release of DMSP/O by different reef taxa is poorly understood. Recently the importance of mesophotic reefs as refugia for shallow water corals has been postulated, however their role in the marine sulphur cycle is unknown. This research aimed to improve our understanding of the contemporary and climate change induced seawater and tissue production of DMSP/O in a range of reef environments and taxa. This was achieved through a combination of laboratory and field - based studies, using modern and established techniques. An effect of both elevated temperature and OA on increased tissue and seawater concentrations of DMSP/O production is reported in field and laboratory studies. Contrasting effects of benthic cover on tissue DMSP/O distributions and seawater DMSP are also noted. The importance of the physical and hydrodynamic environment on biogeochemical connectivity both within a reef and between neighbouring reefs is also focussed on. Crucially, however, the novel tissue and seawater data from mesophotic sites suggests that deeper reefs could affect the biogeochemistry of their shallow water counterparts. The key finding from this work is that climate change will result in increased seawater DMSP concentrations via two mechanisms; through the increase of cellular production of DMSP/O in all reef taxa, and by increasing the biomass of prolific DMSP producers as reefs transition to a fleshy/macroalgal assemblage. Whilst this could potentially mediate the effects of climate change, it will probably also worsen overall reef health, lead to a restructuring of reef communities from the microbial level upwards and will have possibly permanent and deleterious effects on overall ecosystem function.

The thesis entitled “Design and Development of Metal-Free Cross Dehydrogenative Coupling Reactions for the construction of C-S, C-O and C-C bonds” is divided into three Chapters. Chapter 1 is presented in five parts, which reveals the cross dehydrogenative coupling (CDC) strategies for the C–S bond forming reactions through C–H functionalization strategy using heterocyclic thiols and thiones. Chapter 2 presents tetrabutyl ammonium iodide (TBAI) catalyzed chemoselective α-aminoxylation of ketones with N-hydroxyimidates using TBHP as oxidant under cross dehydrogenative coupling (CDC) strategy. Chapter 3 describes a transition metal-free Minisci reaction for the acylation of isoquinolines, quinolines, and quinoxaline. Chapter 1 Iodine Promoted C-S Bond Forming Reactions using Dimethyl Sulfoxide as an Oxidant Chapter 1 reveals the utility of cross dehydrogenative coupling (CDC) reactions for the formation of C–S bonds by employing C–H functionalization strategies.1 The direct functionalization of C–H bonds to form C–C and C–X (N, O, S and P) bonds using metal-free reaction conditions is an interesting research topic in recent years.2 Use of dimethyl sulfoxide as an oxidant is emerging as one of the research topics of great interest and utility.3 Heterocyclic thiols and thiones are important precursors for synthesizing a variety of pharmaceuticals and biologically active compounds.4 Therefore it is useful to develop CDC reactions using heterocyclic thiols and thiones as precursors. In this chapter, we describe CDC reactions of heterocyclic thiols and thiones for the sulfenylation of ketones, aldehydes, α, β unsaturated methyl ketone derivatives, pyrazolones, enaminones and imidazoheterocycles using DMSO as an oxidant Chapter 1: Part 1 Iodine Promoted Regioselective α-Sulfenylation of Carbonyl Compounds using Dimethyl Sulfoxide as an Oxidant: In this chapter, a rare regioselective C–H sulfenylation of carbonyl compounds with heterocyclic thiones and thiols have been described using iodine and dimethyl sulfoxide as reagents. Thus, dimethyl sulfoxide (as an oxidant) and stoichiometric amount of iodine have been used for the sulfenylation of ketones using heterocyclic thiones. Whereas the sulfenylation of ketones with heterocyclic thiols required catalytic amount of iodine. This protocol offers a rare regioselective sulfenylation of (i) methyl ketones in the presence of more reactive α-CH2 or α-CH groups, and (ii) aldehydes under CDC method. A few representative examples are highlighted in Scheme 1.5 The application of this methodology has been demonstrated by synthesizing a few precursors for Julia-Kocienski olefination intermediates. Scheme 1. Iodine promoted rare regioselective α-sulfenylation of ketones and aldehydes Siddaraj , Y.; Prabhu, K. R. Org. Lett. 2016, 18, 6090 Chapter 1: Part 2 Regioselective Sulfenylation of α’-CH3 or α’-CH2 Groups of α, β Unsaturated Ketones using Dimethyl Sulfoxide as an Oxidant: In this chapter, an interesting regioselective sulfenylation of α’-CH3 or α’-CH2 groups of α, β unsaturated ketones using dimethyl sulfoxide as an oxidant and catalytic amount of aq. HI (20 mol %) as an additive has been described. This eco-friendly method uses readily available, inexpensive I2 or HI and DMSO. This methodology exhibits a high regioselectivity without forming Michael addition product in the presence of strong acid such as aq. HI or iodine, which is difficult to achieve under cross dehydrogenative coupling (CDC) conditions. Current methodology exhibits a broad substrate scope. A few examples are shown in Scheme 2.6 Scheme 2. HI and DMSO promoted α’-sulfenylation of α, β unsaturated ketones Siddaraju, Y.; Prabhu, K. R. (Manuscript submitted) Chapter 1: Part 3 Iodine Catalyzed Sulfenylation of Pyrazolones using Dimethyl Sulfoxide as an Oxidant: In this chapter, a sustainable and efficient strategy for the sulfenylation of pyrazolones has been described using metal-free conditions by employing DMSO as an oxidant and iodine as a catalyst. A variety of heterocyclic thiols, heterocyclic thiones and disulfides undergo C–H functionalization reaction with pyrazolone derivatives furnishing the corresponding sulfenylated products in short time. Most of the products are isolated in pure form without column purification. A few examples are presented in Scheme 3.7 Scheme 3. Iodine promoted sulfenylation of pyrazolones Siddaraju, Y.; Prabhu, K. R. Org. Biomol. Chem. 2017, 15, 5191 Chapter 1: Part 4 Iodine-Catalyzed Cross Dehydrogenative Coupling Reaction: Sulfenylation of Enaminones using Dimethyl Sulfoxide as an Oxidant: In this chapter, synthesis of poly functionalized aminothioalkenes has been described using substoichiometric amount of iodine and DMSO as an oxidant. This metal-free methodology enables a facile sulfenylation of enaminones with heterocyclic thiols and thiones. This methodology is one of the simple approaches for the sulfenylation of enaminones under cross dehydrogenative coupling method. A few examples are highlighted in Scheme 4.8 Scheme 4. Cross-dehydrogenative coupling approach for sulfenylation of enaminones Siddaraju, Y.; Prabhu, K. R. J. Org. Chem. 2017, 82, 3084 Chapter 1: Part 5 Iodine-Catalyzed Cross Dehydrogenative Coupling Reaction: A Regioselective Sulfenylation of Imidazoheterocycles using DMSO as an Oxidant: In this chapter, a simple synthetic approach for the regioselective sulfenylation of imidazoheterocycles using iodine as a catalyst and DMSO as an oxidant under cross dehydrogenative coupling (CDC) reaction conditions has been demonstrated. This protocol provides an efficient, mild and inexpensive method for coupling heterocyclic thiols and heterocyclic thiones with imidazoheterocycles. This is the first report on sulfenylation of imidazoheterocycles with heterocyclic thiols and heterocyclic thiones under metal-free conditions. A few examples are shown in Scheme 5.9 Scheme 5. Cross-dehydrogenative coupling approach for sulfenylation of imidazoheterocycles Siddaraju, Y.; Prabhu, K. R. J. Org. Chem. 2016, 81, 7838 Chapter 2 Chemoselective α-Aminoxylation of Aryl Ketones: Cross Dehydrogenative Coupling Reactions Catalyzed by Tetrabutyl Ammonium Iodide: In this chapter, chemoselective α-aminoxylation of ketones with N-hydroxyimidates catalyzed by tetrabutyl ammonium iodide (TBAI) has been presented. The coupling reaction of a variety of ketones with N-hydroxysuccinimide (NHSI), N-hydroxyphthalimide (NHPI), N-hydroxybenzotriazole (HOBt) or 1-hydroxy-7-azabenzotriazole (HOAt) using TBHP as oxidant has been investigated. This α-aminoxylation of ketones is chemoselective as aryl methyl ketones, aliphatic ketones as well as benzylic position are inactive under the reaction condition. A few examples are highlighted in Scheme 6.10 The application of this method has been demonstrated by transforming a few coupled products into synthetically useful vinyl phosphates. Scheme 6. Chemoselective α-aminoxylation of ketones with N-hydroxyimidates Siddaraju, Y.; Prabhu, K. R. Org. Biomol. Chem. 2015, 13, 11651 Chapter 3 A Transition Metal-Free Minisci Reaction: Acylation of Isoquinolines, Quinolines, and Quinoxaline: In this chapter, transition metal-free acylation of isoquinoline, quinoline and quinoxaline derivatives with aldehydes has been described by employing TBAB (tetrabutyl ammonium bromide, 30 mol %) and K2S2O8 as an oxidant under cross dehydrogenative coupling (CDC) reaction. This intermolecular acylation of electron-deficient heteroarenes provides an easy access and a novel acylation method of heterocyclic compounds. The application of this CDC strategy has been illustrated by synthesizing isoquinoline-derived natural products. A few representative examples are shown in Scheme 7.11 Scheme 7. CDC reactions of heteroarenes with aldehydes Siddaraju, Y.; Lamani, M.; Prabhu, K. R. J. Org. Chem. 2014, 79, 3856

>Magister Scientiae - MSc / A comparative study of electrolysers using different anodic materials for the electrolysis of brine (sodium chloride) for the production of sodium hypochlorite as a source of A comparative study of electrolysers using different anodic materials for the electrolysis of brine (sodium chloride) for the production of sodium hypochlorite as a source of available chlorine for disinfection of rural water supplies has been undertaken. The electrolyser design used was tubular in form, having two chambers i.e. anode inside and cathode outside, separated by a tubular inorganic ceramic membrane. The anode was made of titanium rod coated with a thin layer of platinum and a further coat of metal oxide. The cathode was made of stainless steel wire. available chlorine for disinfection of rural water supplies has been undertaken. The electrolyser design used was tubular in form, having two chambers i.e. anode inside and cathode outside, separated by a tubular inorganic ceramic membrane. The anode was made of titanium rod coated with a thin layer of platinum and a further coat of metal oxide. The cathode was made of stainless steel wire. An assessment of these electrolysers was undertaken by studying the effects of some variable parameters i.e. current, voltage and sodium chloride concentration. The flow rate was kept unchanged at 50ml/h anolyte and 140ml/h catholyte since it was found to be optimum flow rate for chlorine generation. Figures of merit of the electrolysers were calculated on the basis of three sets of measurements. Analytical methods used for the determination of sodium hypochlorite concentration were iodometric and N, N-Diethyl-p- Phenylenediamine (DPD) titration methods. The DPD titration method was used to determine the chlorine concentration of less than 1mg/L, while the iodometric titration method was used to determine chlorine concentration of ImgIL and above. Sodium chlorate present in the hypochlorite solution was also determined using a spectrophotometric method. The cobalt oxide electrolyser has been shown to be superior as compared to the ruthenium dioxide and manganese dioxide electrolysers in terms of hypochlorite generation. Sodium chlorate was present but at concentration levels not hazardous for use in dosing water for drinking purposes. Analysis of hydroxyl radicals was undertaken since there were claims that these are produced during brine electrolysis. Hydroxyl radical analysis was not successful, since sodium hypochlorite and hypochlorous acid interfere using the analytical method described in this study.

<p>U ovoj doktorskoj disertaciji proučavano je građenje&nbsp;kompleksa kobalta(II) sa hloridnim i &nbsp;bromidnim jonima u&nbsp;rastopima koji sadrže jednu neorgansku so i jedno organsko&nbsp;jedinjenje i/ili vodu pri različitom sastavu sistema i na različitim&nbsp;temperaturama. Jedan od sistema je amonijum-nitrat &ndash;&nbsp;acetamid &ndash; voda sastava NH₄NO₃∙(2,61-z)CH₃CONH₂∙zH₂O (z =&nbsp;0,0 1,61 i 2,61), a drugi sistem je amonijum&ndash;nitrat &ndash; dimetilsulfoksid&nbsp;(DMSO) sastava NH₄NO₃∙zDMSO (z = 1 &ndash; 6), &nbsp;na&nbsp;različitim temperaturama (35, 45, 55 i 65 ^oC).&nbsp;Cilj ovog istraživanja je bio određivanje stabilnosti&nbsp;kompleksa kobalta koji se grade sa sa halogenidnim jonima i&nbsp;komponentama rastvarača, pronalaženje kvalitativne i kvantitativne&nbsp;zavisnosti konstanti stabilnosti kompleksa kobalta(II) sa&nbsp;halogenidnim jonima od temperature i molskog odnosa&nbsp;komponenti sistema NH₄NO₃∙(2,61-z)CH₃CONH₂∙zH₂O odnosno &nbsp;NH₄NO₃∙zDMSO, određivanje termodinamičkih parametara koji&nbsp;karakteri&scaron;u reakcije asocijacije u ovim sistemima.</p> / <p>In this dissertation the complex formation between cobalt(II) and halide ions in the melts consisting of one inorganic salt, an organic compound and/or water has been studied at different temperatures. Two molten salt systems have been investigated: 1) &nbsp;ammonium nitrate-acetamide-water system NH₄NO₃∙(2,61-z)CH₃CONH₂∙zH₂O (z = 0.0 1.61 2.61) and 2) ammonium nitratedimethyl sulfoxide NH₄NO₃∙zDMSO (z = 1 &ndash; 6), at four different temperatures: 35, 45, 55 and 65 ^oC. The purpose of this work was to determine stability of cobalt(II) complexes formed with the halide ions and the components of the solvents, to discribe the qualitative and quantitative relationships between the stability of the complexes and the melt composition, as well as the changes in the cobalt(II) coordination due to a complex formation. Thermodynamic parameters for cobalt(II) &ndash; halide association process in these melts were alsodetermined.</p>