This dissertation describes the synthesis and characterization of fluorescent semiconductor nanoparticles (NPs) in order to optimize their biomedical utility for imaging and sensing applications. While both direct and indirect bandgap semiconductor NPs have been studied, control over their emission properties vary. Quantum confinement (QC), which primarily controls the emission wavelength of nanosized semiconductors, dictates that as the size of semiconductor NPs decrease, the magnitude of the bandgap increases, resulting in changes in the observed emission wavelength: smaller NPs have a larger bandgap, and thus a bluer emission. However, surface, interfacial, or shell defects can act as non-radiative or radiative recombination sites for excitons formed within the NP; the latter results in emission competition with the bandgap transition, as described Chapters 1 and 2. Because the emission wavelengths of direct bandgap semiconductor NPs correlate with size according to the expectations of QC, and are stable in aqueous environments with high quantum efficiencies (quantum yield, QY), current research focuses on their potential biomedical applications. Chapter 3 describes red-emitting CdSe/ZnS quantum dots (QDs) that exhibit a concentration-dependent decrease in fluorescence intensity in response to the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). A mechanistic study was performed to understand a 5-HT-dependent decrease in QD emission and calibration curves relating QD intensity loss to 5-HT concentration in ensemble and single QD studies were generated. Unfortunately, the known toxicity of CdSe-based QDs has generated interest in more benign semiconductor NPs to replace these QDs in biological applications, while maintaining the same degree of control over the emission color and QY. Bulk indirect bandgap semiconductors, such as Si, have low efficiency inter-band transitions, and Si NPs are known to contain radiative defects that can alter the emission wavelength from QC-based size expectations; these competitive emission pathways must be controlled in order for Si NPs to be successfully used in biological applications. In general, synthetic methods that gives precise control over both the particle size and surface termination are needed in order to produce emission controlled Si NPs. Relative to groups II and VI QDs, synthetic routes to prepare Si NPs are few in numbers, and the size vs. defect emission events are difficult to assign. Not only do these assignments vary amongst reports, but they also vary with particle size, solvent, sample age, and identities of the surface ligands. Si NPs have been prepared through two synthetic routes using the Zintl salt, sodium silicide (NaSi) and ammonium bromide (NH4Br) as precursors. Chapter 4 describes the synthesis performed in the solvent N,N,-dimethylformamide (DMF). This reaction produces blue-emitting Si NPs (5.02 ± 1.21 nm) that bear partial hydride surface termination. However, it was determined that the solvent was able to interact with the Si NP surface, and prevent subsequent functionalization. This observation was used advantageously, and Chapter 5 describes a one-pot Zintl salt metathesis of Si NPs (3.9 + 9.8 nm) performed in a bi-functional (amine or carboxylic acid) solvent ligand, where the observations indicated that the solvent ligands coordinate to the Si NP. The emission maxima of the Si NPs prepared from the Zintl salt metathesis exhibited a dependence on the excitation energy, and is indicative of emission that is influenced by QC, which likely originates from deeply oxide embedded 1-2 nm crystalline cores. The Si NPs prepared from the one-pot Zintl salt metathesis were exposed to metals salt ions of varying reduction potentials to determine the band edges by what will or will not be reduced (Chapter 6). By monitoring the emission intensity of the Si NPs, in addition to the UV-Vis of the metal ions, the band edge of Si NPs may be determined. The value of the band edge may lend insight into the origin of Si NP emission. To utilize fluorescent Si NPs for biological applications, red emission is strongly preferred. Unfortunately, when preparing aqueous Si NPs, red emission usually changes to blue, likely from the oxidation of the Si NP surface. Therefore, the red emission needs to be efficiently protected from surface oxidants. Because both increased chain lengths and steric modalities have been found to protect the emission properties of Si NPs, red-emitting, ester-functionalized Si NPs (5.51+1.35 nm) with varying chain lengths and ester termination moieties were prepared to determine the best method of preserving the observed red emission in the presence of potential alcoholic oxidants. By determining the best was to protect Si NPs emission, the red-emission from Si NPs may be preserved for biological applications.

Marineosins A and B are two spiroaminal-ring containing tripyrrole compounds isolated from the marine actinomycete, Streptomyces CNQ-617, and were found to possess potent and selective cytotoxic activity against leukemia and melanoma. Marineosins belong to the prodiginines class of natural products, examples of which are undecylprodiginine and streptorubin B. Unlike marineosins, prodiginines structures are characterized by the presence of fully conjugated tripyrrole nucleus linked to an alkyl chain (that lacks any oxygen). Cyclic prodiginines arise from an oxidative cyclization of the alkyl chain onto the tripyrrole, a step catalyzed by Rieske-oxygenase like enzymes such as RedG. The biosynthesis of prodiginines is directed via the red gene cluster. The unique structural differences between marineosin and other prodiginines spurred the proposal of a number of hypotheses for its biosynthesis, none of which have been experimentally tested. A red gene cluster homolog which has only one extra dehydratase-encoding gene; marA has been identified from the genomic library of Streptomyces CNQ-617, and the identified cluster was proposed to direct the biosynthesis of marineosin. In this study, the identified putative gene cluster was expressed in the heterologous host, S. venezuelae, and marineosin production in the new strain; JND2 was confirmed via LC/MS and 1H-NMR. The new engineered strain also produces a myriad of marineosin related shunt metabolites and pathway intermediates. This study hence presents the first identified gene cluster proved to direct the biosynthesis of marineosin; the mar gene cluster and proves that the cloned cluster encodes most, if not all the enzymes required to direct the biosynthesis of marineosin. Deletion of the Rieske-oxygenase encoding gene; marG (a RedG homolog) from the mar gene cluster led to the accumulation of 2-hydroxyundecylprodiginine; G410 with an m/z 410.28 and molecular formula C25H35O2N3. This data proves that MarG is not responsible for the introduction of the spiromaminal ring oxygen on the alkyl chain, but is required for catalyzing macrocyclic ring formation between C-8 and C-9 of G410. Undecylprodiginine production in marG deletion mutant was not observed which indicates that undecylprodiginine is likely not an intermediate along the pathway for marineosin biosynthesis, and indicates that the spiroaminal ring oxygen is introduced early in the pathway, possibly due to the incorporation of a 3-hydroxy-butyric acid starter unit. Deletion of the dehydratase-encoding gene; marA, from the mar gene cluster led to the accumulation of compounds JN408 and JN422 with m/z 408.26 and 422.24 and molecular formulae C25H33O2N3, and C25H31O3N3, respectively. Purification and structure elucidation of JN408 proves it to be an oxidized marineosin analog which has fully aromatic tripyrrole rings while; purification and structure elucidation of JN422 proves it to be a 9-keto-JN408 derivative. Both JN408 and JN422 compounds have a spiroaminal ring which indicates that MarA does not catalyze spiroaminal ring formation but catalyzes the reduction of pyrrole ring B of JN408 to yield marineosin. Therefore, we are proposing that MarA acts as a dehydrogenase, rather than a dehydratase. We are proposing that the intramolecular spiroaminal ring formation is catalyzed by either MarG or occurs non-enzymatically. JN422 is a shunt metabolite produced due to promiscuous activity of either MarG or an unidentified oxidase in the mar cluster, possibly MarT. From the data generated in this study, we present the first experimentally supported pathway for the biosynthesis of marineosin and the opportunity to generate novel compounds with potentially useful biological activities.

A search of the literature revealed that no study has sought to measure and compare the polarographic solvent properties of the anhydrous aliphatic diamines. In fact, there has been no reported instance of the use of anhydrous 1,3-propanediamine or 1,4-butanediamine in any electro- chemical system.

Like in any modern civilization, roads in Iceland have an important role in thedaily lives of inhabitants. Consequently, road quality is of equal importance, butIcelandic roads have shown problems when surface dressing is used where itlooks decent after being paved during summer but then deforming pretty rapidlyafter being hit by elements of winter. Roads in Sweden however, do not seem tohave the same problem.The aim of this study is to minimize this road deformation by examining surfacedressing and aggregates. The Icelandic climate is also a factor to this problemsince the humidity is comparatively high, summers are cool, winters are mild andthe climate is overall challenging. Furthermore, winter thaws are distinctivecharacteristic of the Icelandic weather, which increases strain on the asphalt.An experiment was conducted where the adhesion of surface dressing that iscommon in Sweden was tested with two different aggregates by Vialit plateshock test method. First it was tested with Swedish granite and then withIcelandic basalt. The results from the aggregates were compared where theadhesion with the granite was stronger than with the basalt.Previous study have found that by choosing binder and aggregate that have highadhesivity at low temperature reduces the risk of surface dressing defects,especially when paving takes place in the early and late summer season. Whenchoosing aggregates for road construction the main criteria is cost, thereforeaggregates that are used usually reflect the local geology because transportingaggregates for significant distances is expensive. Concluding from theexperiment, it is not recommended to use the basalt with the Swedish surfacedressing in practice now due to the lesser adhesion compared to the granite.However further research on the asphalt mix with the Swedish surface dressingand the basalt should be conducted.

This project was undertaken at one of AstraZeneca's substance factories in Södertälje, Ersättningsfabriken, EFA. The project aimed to facilitate discharge of different solvent streams from the factory. The manufacture of drugs necessitates the use of large quantities of solvent. This creates  a  huge volume of waste to be disposed of. As waste streams leave one of the units in the factory, they are categorized based on their contents and provided with different article numbers. After  the  waste streams leave the units they are sorted and later destroyed according to their article number. The aim of this project was to map out all those waste streams from EFA that travel via the tank cellar to the storage unit, before destruction/purification. Factors such as amount, time of depletion and the way the waste streams travel to AstraZeneca central unit for waste disposal, were evaluated. At the central unit for waste disposal the solvents are stored in destruction tanks before external or internal destruction/purification. The goal of the project was further to develop a plan to reduce the number of bottlenecks that occur whilst emptying units during production and to increase the efficiency of the emptying process. A number of different methods were employed in order to achieve the project's goals. Practical work and a one week internship in production were combined with interviews,  data  collection  from archives, documents  and the use of different programs. A survey of all the waste streams leaving units in the factory was produced. Furthermore, statistics regarding the load in the tanks in the tank cellar and usage of different articles were compiled. A comparison of the methods of sorting waste and the articles was made between AstraZeneca and the external company that collects the  waste. This comparison  led to a recommendation to eliminate one of the articles, as eliminationwould  enable more efficient  usage of  the tank cellar. / Projektet genomfördes på en av AstraZenecas substansfabriker i Södertälje som heter Ersättningsfabriken, EFA, med syftet att underlätta hanteringen av avfallsströmmar från fabriken. Vid läkemedelstillverkning används stora mängder lösningsmedel vilket leder till att stora mängder avfallsströmmar som måste tas om hand. De olika avfallsströmmarna erhåller ett artikelnummer baserat på dess innehåll då de lämnar en enhet i fabriken och sorteras samt destrueras beroende på detta artikelnummer. Projektets inledande mål var att kartlägga alla avfallsströmmar i fabriken som leds via tankkällaren till lagring innan destruktion/rening. Faktorer som undersöktes var mängd, tömningstid och tömningsväg till AstraZenecas centrala enhet för avfallshantering. Vid den centrala enheten lagras lösningsmedlen i destruktionstankar innan extern eller intern destruktion/rening. Målet med projektet var även att reducera antalet krockar som uppstår vid tömning i produktionen då flera enheter önskar tömmas samtidigt samt att utforma en plan för att effektivisera tömningama för smidigare produktion. För att uppfylla projektets olika mål krävdes ett brett arbetssätt för att inhämta information och data. Praktiskt arbete och praktik i produktionen i EFA har kombinerats med intervjuer och datainsamling från arkiv, dokument samt genom användning av olika datorprogram.

The photometric pararosaniline (pRA) method for determination of S(IV) has been adapted to flow injection sample processing (FIA). Prominent features of the method include a limit of detection of 0.010 ppm of dissolved sulfur dioxide and a sampling rate of 20 per hour. The concentration range investigated was 0.010 to 0.200 ppm S02. Sequential samples were collected from two rainstorms and SO2 concentrations were measured for 19 samples. The suppression of interference by Cr(III), Mn(II), and Fe(III) using 1,2-cyclohexylenedinitrilotetraacetic acid (CDTA) and ethylenediaminetetraacetic acid (EDTA) was investigated. A comparison of the adapted FIA method and its parent manual method has shown the FIA method to have the advantages of increased sample throughput, decreased reagent consumption, and increased precision.

The goal of this study is to find a more organized and directed approach to build models for mixture systems. An attempt is made to generate and then compare Scheffe (mixture) models with those generated by McGee using the ‘conventional’ method for neoprene data. The models are judged on their ability to predict physical properties of neoprene by comparing the following: predicted and actual values by inspection; the calculated % error of prediction; the squared multiple correlation coefficients; adjusted squared multiple correlation coefficients; the Fisher statistic and significance probability. Scheffe models do not have an intercept term and test statistics which appear on the computer printout are inflated. Pseudocomponents and Scheffe-equivalent models are procedures used to obtain accurate test statistics to describe the selected Scheffe models. The effectiveness of these two procedures is evaluated. Results indicate that Scheffe models are better predictors for the physical properties of neoprene than those generated by McGee using the ‘conventional’ method in 1980. Scheffe-equivalent equations are found to be more reliable than pseudocomponents for generating accurate test statistics to describe the selected Scheffe models.

This report discusses research concerning synthetic applications of enaminoketones. The work may be divided into four parts as follows: a) replacement of the dimethylamino group of certain enaminones by other amine groups through a simple procedure; b) formation of 3-alkyl-pyrazoles; c) formation of 2-amino-4-alkyl-pyrimidines; d) synthesis and subsequent reduction of iminium salts. The starting materials (E-1-(N,N-dimethylamino)-1-alkene-3-ones) have been condensed with hydrazine and guanidine to form pyrazoles and pyrimidines, respectively. The same starting materials have been reacted with POCl3 in CH2Cl2 to produce chlorovinyliminium salts. These have then been reacted in situ with reducing agents to produce chlorovinyl amines. Additionally, the experimental procedures used to produce these products are revealed, and the physical properties of the products are given. Recommendations for future research are made.

Colorimetric methods combined with color-changing chemical probes are widely used as simple yet effective tools for identifying and quantifying a wide variety of molecules in solution. For nucleic acids (DNA and RNA), perhaps the most commonly used colorimetric probe is potassium permanganate, which can be used to identify single-stranded pyrimidines (thymine and cytosine) in polymers. Unfortunately, permanganate is not an effective probe for identifying purines (adenine and guanine), especially in the presence of the more reactive pyrimidines. Therefore, robust methods for discriminating between the purines remain elusive, thereby creating a barrier toward developing more complex colorimetric applications. In this dissertation, we demonstrate that chromophores such as permanganate and bicinchoninic acid (BCA) and copper, however, when combined with nucleobase-specific chemical cleavage reactions, can be a colorimetric probe for the identification and quantification of cytosines, adenines and/or guanines in single-stranded DNA oligomers, even in the presence of thymines. Furthermore, the reactions are stoichiometric, which allows for the quantification of cytosine, adenine and/or guanine frequency in these oligomers. The BCA/copper reagent detects the reducing sugar, 2-deoxyribose, resulting from the chemical cleavage of a given nucleotide’s N-glycosidic bond. Therefore, these colorimetric assays are effectively detecting abasic sites in DNA oligomers, which are known to occur in damaged DNA. Our analytic approach termed colorimetric identification of exposed nucleic acids (CIENA) combines the use of BCA/copper, permanganate, and diphenylamine chromophores along with digital image capture to identify and quantify each nucleobase within DNA. The digital image color properties are quantified in terms of the image’s hue, saturation, and lightness using the CIELAB color space and ΔE quantification of color. CIENA is a simple, low-cost tool that could be applicable in various types of nucleic acid analyses, such as the quantification of nucleobase composition and the identification of damaged DNA.

Converting solar energyto fuels such as hydrogen by the reaction of water splitting is a promising solution for the future sustainable energy systems. The theme of this thesis is to design water splitting devices via molecular engineering; it concerns the studies of both electrochemical-driven and photo-electrochemical driven molecular functional devices for water splitting. The first chapter presents a general introduction about Solar Fuel Conversion. It concerns molecular water splitting catalysts, light harvesting materials and fabrication methods of water splitting devices. The second chapter describes an electrode by immobilizing a molecular water oxidation catalyston carbon nanotubes through the hydrophobic interaction. This fabrication method is corresponding to the question: “How to employ catalysts in functional devices without affecting their performances?” In the third chapter, molecular water oxidation catalysts were successfully immobilized on glassy carbon electrode surface via electrochemical polymerization method. The O-O bond formation pathways of catalysts on electrode surfaces were studied. This kinetic studyis corresponding to the question: “How to get kinetic information of RDS whena catalyst is immobilized on the electrode surface?” Chapter four explores molecular water oxidation catalysts immobilized on dye-sensitized TiO2 electrodeand Fe2O3 semiconductor electrode via different fabrication methods. The reasons of photocurrent decay are discussed and two potential solutions are provided. These studies are corresponding to the question: “How to improvethe stability of photo-electrodes?” Finally, in the last chapter, two novel Pt-free Z-schemed molecular photo-electrochemical cells with both photoactive cathode and photoactive anode for visible light driven water splitting driven were demonstrated. These studies are corresponding to the question: “How to utilizethe concept of Z-schemein photosynthesis to fabricate Pt-free molecular based PEC cells? / <p>QC 20160129</p>