The purpose of this study was to examine the hairdresser’s knowledge about the chemicals they handle in their business and how they were handling the chemicals and the risks that follows. 9 Salons were visited to gather information. The same questions were asked at the salons. A sample of hair color products was photographed to gather information about ingredients and labeling. The conclusions of the study were that hairdressers have good knowledge about the risks related to human health but they need to improve their knowledge when it comes to environmental risks. The deficiencies that were found were that they lack knowledge about the laws concerning the use and distribution of cosmetics products and that not all saloons are handling the hazardous waste and residues from treatments correctly. The risks that could follow are that not enough is done to protect human health and the environmental. To prevent that damage to human health and the environmental occurs they should use more sources that focus on health and environmental to gather information about the risks with the chemicals they are handling, they should also limit the treatments on children and always inform about the risks when they are using products that can cause an allergic reaction. Keywords: Risks hairdressing, cosmetics products, p-phenylenediamine, Toluene-2,5-diamine, ammonia.

Aromatic polyimides have found widespread applicability which can be partially attributed to their thermal stability, chemical resistance, and high glass transition temperature. However, deficiencies in their processability, solubility, transparency, and relatively high dielectric constants do not always provide the optimum properties for many specialty microelectronics applications. The incorporation of aliphatic segments to form partially aliphatic polyimides, has been used to counteract these shortcomings. Many of the potential uses of partially aliphatic polyimides require them to adhere to ceramic substrates, a main topic of this research. Polyimides and copolyimides that varied in chemical composition by their aliphatic content were characterized by their molecular weight, glass transition temperature, thermal stability, coefficient of thermal expansion, refractive index, dielectric behavior, and mechanical properties. Structure-property relationships were established. The gamma and beta sub-Tg viscoelastic relaxations were investigated to understand their molecular origins. The adhesion performance of a selected series of partially aliphatic polyimides to SiO2/Si was examined using a shaft loaded blister test, which was designed and instrumented for use in a dynamic mechanical analysis instrument. The adhesion was studied at high and low percent relative humidities and for several temperatures to examine if adhesion strength is influenced by polymer chemical composition. The adhesion energy could not be quantified for the entire series of polyimides. It was possible to interpret the quantitative adhesive fracture energies along with the qualitative adhesion strength behaviors, the failure surface analyses, and to offer an understanding of the adhesive chemical structure-physical property relationships. These understandings provide a conclusion that the incorporation of aliphatic segments into the polyimide chemical structure improves the durability of the adhesive bond to SiO2/Si under high percent relative humidities. / Ph. D.

N-methylputrescine oxidase (MPO) is a member of the diamine oxidase (DAO) class of enzymes believed to be responsible for synthesis of the alkaloid nicotine in the roots of Nicotiana tabacum (Mizusaki et al., 1972). A purportedly pure MPO protein from tobacco root culture extracts was used to generate immune antiserum in rabbits (McLauchlan et al., 1993). In an attempt to clone a cDNA encoding MPO, we used this antiserum to screen a tobacco cDNA expression library. Unexpectedly, two previously unreported genes with strong homology to members of a gene family encoding S-adenosylhomocysteine hydrolase (SAHH) in N. sylvestris and a gene encoding SAHH in N. tabacum were cloned instead. SAHH is an enzyme of the S-adenosylmethionine (SAM) recycling pathway, which also includes SAM synthetase (SAMS) and methionine synthase (MS). These results led to the hypothesis of a multi-enzyme complex, or metabolon, of at least one member of the nicotine biosynthesis pathway, i.e., MPO, and at least one member of the SAM recycling pathway, i.e., SAHH, during nicotine biosynthesis. Metabolons are stable noncovalent complexes in cells that ensure sufficient passage of the product of one enzyme reaction to the next enzyme in the pathway via a "channel" without equilibrating with the bulk solution (Ovádi, 1991). My research employed co-immunoprecipitation studies to determine if other SAM recycling enzymes are associated in a complex with MPO and SAHH, as well as Northern and Western blot analyses to determine if the genes encoding SAM recycling pathway enzymes are coordinately regulated during nicotine biosynthesis. Our results indicate that nicotine biosynthesis-inducing conditions result in differential mRNA accumulation patterns of the three enzymes of the SAM recycling pathway, although to different extents. However, protein levels of SAM recycling pathway members do not appear to reflect the differential mRNA accumulation patterns. We have firmly established an association of SAHH and an enzyme with DAO activity, purportedly MPO. If the enzyme is proven to be MPO, then our data would constitute the first documentation of an alkaloid metabolon. Finally, using a degenerate primer PCR approach, we have cloned a 986-bp gene fragment with homology to copper amine oxidases, the class to which MPO belongs. / Master of Science

Pour développer de nouveaux outils synthétiques, nous avons élaboré des variantes de la réaction de Petasis. L’utilisation des α-amino aldéhydes dans la réaction de Petasis a permis de synthétiser des diamines chirales avec une diastéréosélectivité totale. La réaction a donnée de bons résultats avec différents groupements protecteurs de l’amine (sulfonamide, carbamate, amide). Cependant au cours de la réaction, les amino aldéhydes s’épimérisent et l’excès énantiomérique des diamines préparées est donc faible (30%). La réaction de Petasis a été associée à la réaction de Diels-Alder dans un procédé domino pour aboutir à l’obtention de composés de type hexahydroisoindole. La réaction domino est complètement diastéréosélective et les molécules sont obtenues de manière énantiopure. Un second procédé domino, utilisant une réaction de métathèse croisée suivie d’une addition 1,4 intramoléculaire, a permis d’obtenir des composés possédant un motif morpholine de manière diastéréosélective. Une version intramoléculaire de la réaction de Petasis a été mise au point dans le but d’obtenir des carbocycles à six chainons. Cette réaction a permis de préparer la (+)-conduramine C-4 en peu d’étapes. La cyclisation a montré une diastéréosélectivité surprenante puisque la configuration entre l’amine nouvellement formée et l’alcool est trans. Cette configuration est opposée à celle obtenue dans la version intermoléculaire. / To develop new synthetic tools, we developed variants of the Petasis reaction. The use of α-amino aldehydes in the Petasis reaction allowed to synthesize chiral diamines with a total diastereoselectivity. The reaction gave good results with different protective groups of the amine (sulfonamide, carbamate, amide). However, during the reaction, the amino aldehydes are epimerized and the enantiomeric excess of the prepared diamines is low (30%). The Petasis reaction was associated with the Diels-Alder reaction in a domino process to achieve the preparation of hexahydroisoindole type compounds. The domino reaction is completely diastereoselective and the molecules are obtained as enantiopure. A second domino process, using a cross-metathesis reaction followed by an intramolecular 1,4-addition, yielded compounds with a morpholine moiety in a diastereoselective manner. Intramolecular version of the Petasis reaction was developed in order to obtain carbon-six-membered rings. This reaction led to the preparation of (+)-conduramine C-4 in few steps. The cyclization has shown a surprising diastereoselectivity since the configuration between the newly formed amine and alcohol is trans. This configuration is opposite to the one obtained in the intermolecular versions.

Des nouveaux ligands chiraux diamine N-aromatiques, dérivés de 1,2-diaminocyclohexane et des a et ß- cétones cycliques aromatiques, ont été synthétisés par alkylation-déshydrogénation catalysée par le palladium sur charbon (Pd/C). Cette méthode, nous a permis de préparer un série des ligands chiraux de types N,N-di-aryles diamine and N-aryle diamine avec de très bons rendements isolés.Premièrement, les efficacités des ligands synthétisés ont été examinées avec succès dans la réaction de réduction par transfert d'hydrure des cétones aromatiques, catalysée avec des catalyseurs homogènes d'iridium formés in situ iridium assistés par l'acide formique et son sel de sodium. Des cétones aromatiques variés ont été réduits, suivant la méthode y développée, en des alcools correspondants avec des complètes et des hautes énantiosélectivités (ee jusqu'au 93%). Ensuite, deux ligands diamine, N,N'-dinaphtyle diaminocylohexane et N-naphtyle diaminocylohexane complexés avec le Cu (II) ont été évalués dans la réaction asymétrique de Henry entre des dérivés de benzaldéhyde et le nitrométhane conduisant aux ß-nitro-aryle-alcools avec des bonnes énantiosélectivités (ee jusqu'au 83%) et des bons rendements isolés. On a aussi transformé ces deux ligands, en sels d'imidazolinium précurseurs des carbènes, pour des ultérieures application en catalyse asymétrique. Le dérrivé mono N-aryle diamine a été transformé en ligand mono-thio. Les trois ligands ainsi préparés ont été obtenus avec des bons rendements isolés / New chiral N-arylated diamine ligands, derived from 1,2-diaminocyclohexane and a and ß-cyclic-aromatic ketone, were synthesized by dehydrogenative alkylation catalyzed by palladium on carbon (Pd/C). This method, allowed to prepare a series of chiral N,N-diarylated diamine and N-aryl diamine ligands with very good isolated yield.First of all, the applicability of the synthesized chiral diamine ligands was successfully examined in asymmetric transfer hydrogenation with homogeneous iridium catalyst associated to formic acid and its sodium salt. Various aromatic ketones were reduced to chiral alchohol with a complete conversion and high enantioselectivity (ee up to 93%). Then, two of the prepared chiral diamine, N,N’-dinaphtyl diaminocylohexane and N-naphtyl diaminocylohexane combined to copper (II), have been evaluated in asymmetric Henry reaction between benzaldehyde derivatives and nitromethane leading to ß-nitro-aryl-alcohol with good enantioselectivities (ee up to 83%) and good isolated yields.Furthermore, we transform these two ligands into imidazolinium salts precursor of carbenes, for further application in asymmetric catalysis. The mono N-arylated diamine was transformed into mono-thiourea ligand. These three new ligands were obtained with very good isolated yields

A comparison of the antimicrobial efficacy of silver diamine fluoride and silver nitrate on various cariogenic bacteria: an ex vivo study By: Reham AlNajjar, D.D.S. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University. Virginia Commonwealth University, 2019 Thesis Advisor: William Dahlke, D.M.D., Associate Professor and Chair of Pediatric Dentistry, School of Dentistry Purpose: The use of silver-based antimicrobials is an emerging method for the treatment of dental caries. In this study, the authors compare the efficacy of the two most prominent silver- based therapeutics, silver diamine fluoride (SDF) and silver nitrate (AgNO3), on cariogenic and non-cariogenic multispecies biofilms. Currently there is a lack of studies comparing the efficacy of SDF to AgNO3. Methods: Plaque samples from anterior and posterior tooth sites from children presenting both with early childhood caries and caries-free children were collected, pooled, and utilized to create four ex vivo biofilm systems in artificial saliva. SDF and AgNO3 were administered to these biofilms and bacterial survival was quantified and compared to untreated controls. Results: Each of the four pooled sample types was applied to plates coated in artificial saliva + 1% sucrose. Both SDF and AgNO3 were very effective against plaque derived biofilms when compared to untreated biofilms (P0.05) in the potency of each compound. Conclusions: SDF and AgNO3 significantly inhibit ex vivo cariogenic and non-cariogenic biofilms at similar levels.

Thesis (Ph.D. (Nutrition))--North-West University, Potchefstroom Campus, 2007.

In this research water dispersed epoxy varnishes were produced by reacting solid epoxy resin with ethylene diamine (EDA) and maleinized fatty acids of linseed oil. Maleinized fatty acid (MFA) was produced by the maleinization process, in which, fatty acid and maleic anhydride were reacted under nitrogen atmosphere. Maleinization was performed in order to insert hydrophilic groups to the fatty acid chains, which were then inserted to the backbone of the epoxy resin. This was done to give water dispersibility to the hydrophobic epoxy resin. Solid epoxy resin was dissolved in 1,4-dioxane. Ethylene diamine was then added to the solution at 50&deg / C, and stirred for 4 hours. Then the temperature was increased to 80oC and kept for 2 hours. Maleinized fatty acids were then introduced, and the reaction was carried out at 90oC for 10 hours. 1,4-dioxane was used for the removal of the water, which forms as the byproduct. Then the driers were added. The carboxylic groups of the maleinized fatty acid were neutralized by morpholine and the product was dispersed in water. The varnish was applied on test panels and left for air-drying for 24 hours and then baked at 140&deg / C for 5 hours. The free epoxy content was determined by pyridinium-chloride titration and it was seen that all the epoxy groups reacted. Also, produced fatty acid was characterized by FTIR spectroscopy and maleinized fatty acid was characterized by H-NMR and FTIR spectroscopy. Hardness, bending, impact resistance, gloss, and abrasion resistance tests were carried out on hardened varnish specimens. The samples generally showed good mechanical and physical properties. While the baking time was increased the hardness of product increased. Samples showed superior impact resistance, gloss, and flexibility.

Background: The high prevalence of iron deficiency and anaemia among South African children highlights the need for iron fortification, especially with a highly bioavailable iron compound. Fortification of staple foods is an adequate strategy to provide additional iron to populations at risk. In South Africa it is mandatory to fortify maize meal and wheat flour with iron, as well as other micronutrients. Elemental iron, specifically electrolytic iron, is currently the preferred choice but other compounds that might be more effective in alleviating iron deficiency are under consideration. Objectives: The objective of this study was to provide information about the bioavailability of ferrous fumarate and NaFeEDTA from maize meal porridge in young children, which would assist in selecting a bioavailable alternative to electrolytic iron in the South African National Food Fortification Programme, Methods: A randomized parallel study design was used, with each of the 2 groups further randomised to receive either one of two test regimens in a crossover design in which each child acted as his/her own control. Iron bioavailability was measured with a stable-isotope technique based on erythrocyte incorporation 15 days after intake. Results: The mean absorption of iron from NaFeEDTA and ferrous fumarate from the maize porridge meal was 11.5% and 9.29% respectively. NaFeEDTA and ferrous fumarate are both sufficiently bioavailable from a maize based meal rich in phytates. Conclusion: Both NaFeEDTA and ferrous fumarate would provide a physiologically important amount of iron should they replace electrolytic iron as fortificant in maize flour fortification. The final choice between ferrous fumarate and NaFeEDTA as when it comes to finding the alternative iron fortificant will depend on factors such as technical compatibility, bioavailability, relative cost and organoleptic characteristics. / Thesis (Ph.D. (Nutrition))--North-West University, Potchefstroom Campus, 2007

Background: The high prevalence of iron deficiency and anaemia among South African children highlights the need for iron fortification, especially with a highly bioavailable iron compound. Fortification of staple foods is an adequate strategy to provide additional iron to populations at risk. In South Africa it is mandatory to fortify maize meal and wheat flour with iron, as well as other micronutrients. Elemental iron, specifically electrolytic iron, is currently the preferred choice but other compounds that might be more effective in alleviating iron deficiency are under consideration. Objectives: The objective of this study was to provide information about the bioavailability of ferrous fumarate and NaFeEDTA from maize meal porridge in young children, which would assist in selecting a bioavailable alternative to electrolytic iron in the South African National Food Fortification Programme, Methods: A randomized parallel study design was used, with each of the 2 groups further randomised to receive either one of two test regimens in a crossover design in which each child acted as his/her own control. Iron bioavailability was measured with a stable-isotope technique based on erythrocyte incorporation 15 days after intake. Results: The mean absorption of iron from NaFeEDTA and ferrous fumarate from the maize porridge meal was 11.5% and 9.29% respectively. NaFeEDTA and ferrous fumarate are both sufficiently bioavailable from a maize based meal rich in phytates. Conclusion: Both NaFeEDTA and ferrous fumarate would provide a physiologically important amount of iron should they replace electrolytic iron as fortificant in maize flour fortification. The final choice between ferrous fumarate and NaFeEDTA as when it comes to finding the alternative iron fortificant will depend on factors such as technical compatibility, bioavailability, relative cost and organoleptic characteristics. / Thesis (Ph.D. (Nutrition))--North-West University, Potchefstroom Campus, 2007