This research involves the development of a totally new approach to thermal analysis in which microwave energy is used not only to heat the sample but also to detect thermally induced transformations via the effects of changes in its dielectric properties. Use of these properties, rather than the more usual mass or enthalpy changes of conventional thermal analysis, provide a unique insight into thermal processes. Microwave thermal analysis (MWTA) is a technique for studying the efficiency of the conversion of microwave to thermal energy by measuring the microwave power-temperature relationship for different materials. Power/temperature verses time profiles in some cases give an indication of physical and chemical changes occurring in the sample, via changes in the dielectric constant. An instrument for performing microwave thermal analysis (MWTA) has been designed, constructed and applied to an extensive range of chemical systems exhibiting a variety of physicochemical transformations, including melting, decomposition and solid-solid phase changes. MWTA has been shown to provide both qualitative and quantitative information with sample masses ranging from the analytical (1 to 20 mg) to semi-preparative (0.5 to 5.0 g) scales. It has been demonstrated that MWTA can be used in conjunction with complementary techniques such as differential thermal analysis (DTA) and X-ray powder diffraction (XRD) to provide additional data. MWTA has the potential to be extended to incorporate some of the latest developments in thermal analysis, including methods involving temperature modulation and evolved gas analysis. MWTA has the potential to have applications in the design of industrial processes by providing detailed information on the effect of microwave radiation on both physical (e.g. phase changes) and chemical processes.

Phytoextraction in the UAE desert soil (sandy, calcareous, less than 0.5% humus, and pH 7.9) has been studied. Twelve suspected polluted sites were investigated for contamination with eight heavy metals and sixteen local plants from the UAE desert were evaluated for their ability to accumulate heavy metals. The soil of Ajman industrial zone demonstrated high amounts of total chromium (1800 mg/kg) and of hexavalent chromium (97 mg/kg) which is a significant environmental threat. Portulaca oleracea (Purslane) has been shown to be the best candidate for Cr(VI) accumulation. Total chromium concentration exceeded 4600 mg/kg in roots and 1400 mg/kg in stems confirming the role of P. oleracea as a Cr(VI) accumulator. More than 95% of the accumulated Cr(VI) was reduced to the less toxic Cr(III) within the plant. The uptake of Cr(VI) by this plant has been investigated. The uptake of Cr(VI) increased as its concentration in soil increased between 50 and 400 mg/kg. The highest Cr(VI) uptake was observed at the high pH and low organic matter content of soil confirming the phytoextraction efficiency of P. oleracea in soils found in the UAE. The uptake of Cr(VI) increased in the presence of sulfate anion (suggesting that chromate uses the same carriers of sulfate in root cells) while nitrate and phosphate retarded the uptake. Potassium and ammonium ions, but not sodium ions, enhanced the uptake of Cr(VI) confirming the effect of accompanying cations. EDTA enhanced the translocation factor of chromium from roots to shoots in plants irrigated with either Cr(III) or Cr(VI). HPLC-MS analysis showed that ascorbic acid is the main antioxidant that reduced Cr(VI) to Cr(III) which is then mostly translocated to shoots after chelation with organic acids such as oxalate since glutathione and phytochelatins were not observed at significant levels in the tissues of plants exposed to Cr(VI).

Described herein, is the synthesis and coordination chemistry of seven novel ligands L1 - L7. These ligands form metallosupramolecular assemblies upon coordination of transition metal ions resulting in heterodi- and hetreotrimetallic double helicates and penta- and tetranuclear cyclic helicates. Described in Chapter 2 is a new class of ditopic segmental pyridyl-thiazole(py-tz) N-donor ligands L1 - L3. Reaction of L1 with ZnII ions results in the formation of a dinuclear double helicate [Zn2(L1)2]4+. Reaction of L2 with either ZnII or HgII results in the formation of the L2-containing dinuclear double helicates [Zn2(L2)2]4+ and [Hg2(L2)2]4+. However, reaction with both ZnII or HgII results in the sole formation of the heterodimetallic helicate [HgZn(L2)2]+. Both metal ions are 6-coordinate but the HgII ion is coordinated by the two py-tz-py units whereas the ZnII ion is coordinated by the py-py-tz domain. The reason that these isomeric sites have different preferences for each of the metal ions is due to the position of the thiazole unit within the terdentate domains, as in the central position the thiazole unit increases the “bite angle” of the donor unit making it more suitable for the larger HgII. Conversely the py-py-tz domain has a smaller bite angle and it more suited to the smaller ZnII ion. Reaction of L3 with ZnII, HgII and CuII results in the formation of a heterometallic trinuclear double helicate [HH-[HgCuZn(L3)2]5+. In a similar fashion to L2, the ZnII ion coordinated by the terdentate py-py-tz domain and the HgII coordinated by the py-tz-py domain. The central bipyridine unit coordinates the tetrahedral CuII ion resulting in the first reported example of a heterotrimetallic double helicate. Described in Chapter 4 is a potentially hexadentate N-donor ligand L4, which upon reaction with CdII results in the formation of a dinuclear double helicate [Cd2(L4)2]4+. In this structure the ligand partitions into two tridentate tz-py-py domains each of which coordinate a different metal ion. However, reaction of L4 with ZnII results in the formation of a pentanuclear circular helicate [Zn5(L4)5]10+, with all the five zinc ions adopting a octahedral coordination geometry arising from the coordination of the two tridentate tz-py-py domains from two different ligand strands. This difference in structure is attributed to unfavourable steric interactions which prevent the formation of [Zn2(L4)2]4+ but these unfavourable interactions are not present with the larger Cd2+ ion. Described in Chapter 5 are the potentially pentadentate and tetradentate ligands L5 and L6, respectively. The ligand L5 contains both a bidentate and tridentate binding site separated by a phenylene spacer unit. Reaction of L5 with CuII results in the formation of a pentanuclear circular helicate [Cu5(L5)5]10+. Each of the CuII ions adopts a 5-coordinate geometry formed by coordination of the bidentate domain of one ligand strand and the tridentate domain of a different ligand. As a result this gives a head-to-tail pentanuclear double helicate. Reaction of L6 and L4 (Chapter 4) with CuII results in the formation of a heteroleptic pentanuclear circular helicate [Cu5(L4)3(L6)2]10+. The cyclic array consists of five copper(II) ions, coordinated by three strands of L4 and two strands of L6. In this species four of the CuII adopt a 5- coordinate geometry arising from coordination of a tridentate domain from L4 and a bidentate domain from L6. The remaining copper ion is coordinated by two tridentate domains from L4 resulting in an octahedral coordination geometry. Described in Chapter 6 is the potentially hexadentate N-donor ligand L7 which comprises of two identical tridentate py-py-tz N3 binding domains separated by a pyrene unit. Reaction of L7 with ZnII results in the formation of a tetranuclear circular helicate [Zn4(L7)4]8+ with all four zinc metal ions adopting a six-coordinate geometry arising from the coordination of two tridentate pypy- tz units from two different ligand strands. The formation of this lower nuclearity species (e.g. tetranuclear rather than pentanuclear) is attributed to the p-stacking between the pyrene unit and the py-py-tz domain.

Heparan Sulphate plays an important role in many life processes and so an understanding of its role as a universal co-receptor is of great importance. Traditionally oligosaccharides derived from the related molecule heparin have been at the forefront of molecular drug design, due to its similarity in structure and function. To obtain a more complex and detailed picture of the role of HS in structural biology further complex work must be undertaken on HS. Here in this study a number of HS derived octasaccharides have been purified. Alongside this is work carried on HS derived decasaccharides, of which all have undergone extensive molecular modelling simulations. The role of the Iduronates in the HS structure, at monosaccharide level has indicated a major role for these structures in biological activity. Further work has indicated the level of sulphation is also a requirement which in turn influences conformational behaviour. Up until now this has only really been studied at the monosaccharide level and so this study has generated a number of different HS models which can confirm the importance of iduronate conformation in biological activity. Not only that but it has also been identified that certain torsional geometries within the glycosidic bonds between monosaccharides also has a major influence on conformation. Local deviations in the molecular modelling data suggest there is a slight difference between active and inactive oligosaccharides with the ability to bind and activate the HS:FGF2:FGFR IIIc complex. The implications of these and other structural insights are discussed with the implication heavily towards a combination of both torsional geometry and iduronate conformation in biological activity. To further aid our understanding HS dp10 oligosaccharides were docked into a FGF2 which was in a complex with a heparin hexasaccharide. Docking experiments were carried in order to attain structural information on the binding of these molecules. The Goodger oligosaccharides were docked into the X-ray crystal structure and were chosen specifically for their iduronate conformation or the torsional geometry.

Oat β-glucan is a water soluble polysaccharide which has been approved as a functional bioactive ingredient. In this thesis, β-glucan was successfully isolated from oat flour and samples of different molecular weights were produced. The structural features and molecular weights(Mw) were characterized by 13C–NMR spectroscopy and high performance size-exclusion chromatography, respectively. The rheological properties and microstructure of aqueous oat β-glucan solutions were investigated by rheometry and atomic force microscopy (AFM),respectively. The samples with β-glucan content between 78-86 % on a dry weight basis had Mw, intrinsic viscosity ([η]) and critical coil overlap concentration (c*) in the range of 142 - 2800 x 103 g/mol, 1.7 - 7.2 dL/g and 0.25 - 1.10 g/dL, respectively. The flow and viscoelasticvbehaviour was highly dependent on Mw and on the concentration of the β-glucan solutions. AFM images revealed the formation of cluster or aggregates linked via individual polymer chains scattered heterogeneously throughout the system. The aggregate size was also dependent on molecular weight of the samples and influences the rheological behaviour of β-glucan solutions. The isothermal phase behaviour at 5 oC of β-glucan/sodium caseinate mixtures were investigated by means of phase diagram construction, rheometry, electrophoresis and fluorescence microscopy. Phase diagrams indicated that the compatibility of the β-glucan/sodium caseinate system increases as β-glucan Mw decreases. Images of the mixtures taken at various biopolymer concentrations revealed phase separation with the presence of β-glucan aggregates,whose size depends on Mw and concentration. At the same protein concentration in the mixtures, the viscosity increases with increasing Mw and concentration of β-glucan. However, the results also revealed that in the state of thermodynamic equilibrium with comparable polymer concentrations in mixture, the lower Mw samples yielded similar or higher viscosity. At equivalent hydrodynamic volume of β-glucan component in the mixture, all the samples exhibited similar viscosity/flow behaviour. A deviation dependent on the protein concentration was observed for the high Mw sample in the concentrated regime due to the size of the β-glucan aggregates formed. Results demonstrate that by controlling the structural features of β-glucan in mixture with sodium caseinate, informed manipulation of rheological properties in these systems can be achieved.

Aldehyde oxidase (AO) and xanthine oxidoreductase (XOR) are molybdo-flavoenzymes (MFEs) involved in the oxidation of hundreds of endogenous and exogenous aldehydes and N-heterocyclic compounds many of which are drugs, vitamins and environmental pollutants. Mutations in the XOR and molybdenum cofactor sulfurase (MCS) genes result in a deficiency of XOR or dual AO/XOR deficiency respectively. At present despite AO and XOR being classed as detoxification enzymes the definitive experimental proof of this has not been assessed in any animals thus far. The aim of this project was to evaluate ry and ma-l strains of Drosophila melanogaster as experimental models for XOR and dual AO/XOR deficiencies respectively and to determine if MFEs have a role in the protection against chemical and physical stress. An additional aim was to determine the molecular basis for deficiency in ma-l strains by cloning and sequencing the MCS gene. Spectrophotometric and HPLC assays demonstrated that Drosophila AO and XOR were able to catalyse the biotransformation of numerous substrates of the well-scrutinised mammalian orthologs. These included several aromatic aldehydes and N-heterocyclic pollutants, drugs and endogenous vitamins. Investigation of the enzyme activity in ry strain revealed a compromised ability to biotransform several XOR substrates that reflected the situation in human hereditary xanthinuria type I. Both ma-l strains were found to be unable to biotransform all AO substrates tested. These results confirmed that Drosophila were good experimental models for testing the role of MFEs as detoxification enzymes. In order to test the role of the enzymes in chemoprotection, MFE substrates were administered to Drosophila in media and survivorship monitored. It was demonstrated that several methylated xanthines were toxic to XOR-deficient strains. In addition a range of AO substrates including N-heterocycles and aldehydes were significantly more toxic to ma-l AO-null strains. This study therefore provides definitive proof that both AO and XOR are involved in detoxification. Investigations to determine the effect of MFE deficiencies on lifespan revealed that ry and ma-l strains had significantly reduced lifespan when compared with the wild type strain with the mean lifespan being reduced approximately 60% and 30% respectively ii in these strains. The effect the MFE deficiencies have on heat and cold stress indicated that ry and ma-l strains had significantly reduced ability to survive, with the survivorship of the AO-null ma-l strain being most compromised in these conditions. The effect of the toxic chemicals, lifespan and temperature stress were rescued in ry mutant animals that had the normal ry (XOR) gene reinserted by transgenesis. Cloning and DNA sequencing of the MCS gene in the ma-l strains revealed that the mal-1 and mal-f1 strains had a 6 bp insertion and a 23 bp deletion in exon 4 respectively that are predicted to lead to alterations of the deduced MCS protein structure, thus explaining the dual AO/XOR deficiency in these strains.

A study in search of new heterogeneous catalysts that can be used in place of homogeneous catalysts for biodiesel synthesis has been carried out. The objective of this study is to investigate and evaluate the use of solid catalysts for transesterification of triglycerides and esterification of free fatty acid for biodiesel synthesis. Two types of heterogeneous catalyst have been studied that are solid acid and solid base. Three different solid acids and two solid bases were explored. The solid acids investigated were sulfonated hypercrosslinked polystyrene resin, sulfonated polyvinyl alcohol and sulfated zirconia. The solid bases were lithium zirconate and composite calcium oxide-magnetite. Sulfonated hypercrosslinked polystyrene resin has been studied in the esterification reaction of oleic acid with methanol and rearrangement of α-pinene to camphene and limonenes. The activity of this catalyst was compared with conventional macroporous polystyrene sulfonic acids such as Amberlyst-15, Amberlyst-35 and Nafion SAC-13 which is a composite of Nafion and silica. The activity of this catalyst is superior to those of Amberlysts and SAC-13 in the esterification of oleic acid. This catalyst also has high reusability at elevated temperature. Sulfonated polyvinyl alcohol catalyst has been studied in the same way the esterification of oleic acid and rearrangement of α-pinene. The activity of the catalyst was compared with sulfonated macroreticular polystyrene resin Amberlyst-35 and Nafion SAC-13. In the esterification reaction, sulfonated polyvinyl alcohol shows a better activity than SAC-13 and the Amberlyst-35 resin catalyst. In the rearrangement/isomerisation reaction, the sulfonated polyvinyl alcohol is the least active. The activity of sulfated zirconia as a solid acid catalyst has been studied in the esterification of oleic acid and in simultaneous esterification- transesterification of a mixture oleic acid and triglycerides. In the simultaneous reaction, the activity of this catalyst was compared with sulfonated polystyrene catalysts (Amberlyst-15 Amberlyst-35 and Purolite D5081) and commercial sulfated zirconia XZO-1720. The result showed that in the transesterification reaction, the sulfated zirconias are more active but in the esterification reaction the sulfonated polystyrene catalysts are better than sulfated zirconia. The effect of calcination temperature on the catalytic activity of the catalyst was also studied. The study shows that 600 oC calcination gives the best catalytic activity. The lithium zirconate is one of the solid base catalysts evaluated in this study. The catalyst was very active in the transesterification of tributyl glycerate with methanol. The effect of calcination temperature on its activity in the transesterification reaction of tributyl glycerate was studied. The study shows that 700 oC calcination yielded the highest catalytic activity which is associated with the formation of the tetragonal phase which gives the highest concentration of basic sites and basic strength. A composite between calcium oxide and magnetite is the last catalyst reported in this study. The study of this catalyst is due to ease of separation by an external magnetic field. The catalytic performance in the transesterification of tributyl glycerate and methanol was studied. The catalytic activity of the catalyst was maximum at the calcination temperature of 700 oC. Loss of catalytic activity and magnetic properties were shown at higher calcination temperature. Despite the relatively high activities found for the catalysts studied, further improvement is needed if the catalysts are to be applied for industrial use. However, sulfonated hypercrossliked polystyrene resin catalysts showed promising activity for the pre-esterification reaction and it is one of the best catalysts for reducing free fatty acid in low grade vegetable oil.

This thesis describes three areas of research which involve preparation of novel pyridyl-thiazole-containing ligands and the formation of their complexes with transition metal ions. Chapter 2 describes the preparation, complexation chemistry and photophysical behaviour of ligands L1 and L2 which contain pyrene moieties. The emission properties of pyrene are highly dependent on its environment, and so it was proposed that it could be used as a probe to elucidate solution conformations of complexes. It was shown that incorporation of a pyrene moiety into the ligand strand and subsequent measurement of the emission spectra of its complexes with Cu+ and Cd2+ gave information about their solution state conformations which correlated well with the solid state structures. In Chapter 3, synthesis and coordination complexes of ligands L3 and L4, which contain substituents capable of binding anions, are described. L3 forms a mononuclear complex with Zn(II) which binds two perchlorate anions via the amide groups on the two substituents. However, with Cu(I), L3 and L4 form dinuclear double helicates which have a binding “pocket” at each end of the complex. Both [Cu2(L3)2](ClO4)2 and [Cu2(L4)2](PF6)2 form one-dimensional polymers; the complexes are held together by bridging perchlorate and hexafluorophosphate anions, respectively. Finally, in Chapter 4, allosteric control of the complexation behaviour of ligand L5 is described. L5 contains amine groups on the 3,3’-positions of the bipyridine core which can react with ketones, forming a cyclic aminal product. Reaction with cyclohexanone was used to control the metal specificity of the ligand by restraining the torsion angle between the two pyridine groups and forcing the ligand into planarity. In general, L5 formed dinuclear double helicates with tetrahedral metals and mononuclear complexes with octahedral metals, as expected. Upon reaction with cyclohexanone, mononuclear species were observed with Hg2+, Zn2+, Cd2+ and Ag+. Experiments were then carried out with mixtures of metal ions and two trends were observed: firstly, when L5 is mixed with octahedral and tetrahedral metals, species containing the octahedral metal are favoured. Where two octahedral metals are used species containing the metal with the larger ionic radius are formed preferentially. After reaction with cyclohexanone, only mononuclear species of the octahedral metals are observed in every case.

Body fluid identification (BFID) forms a crucial aspect within forensic investigations. BFID is particularly important where the origin of a DNA profile is also needed e.g. sexual assaults. The aim of this work was to develop a RNA-based BFID for use in forensic casework. The test was developed in three stages: exploring co-isolation and single isolation strategies, screening and selecting RNA markers and different casework conditions e.g. low-level, non-human, degraded and mixed samples. Blood, saliva, skin, semen and vaginal material samples were collected. Samples underwent single or co-isolation (DNA, total RNA or messenger RNA), DNA quantification, cDNA synthesis and qPCR using a number of different candidate markers and reference genes for microRNA (miRNA) and messenger RNA. During the development of the test the following novel findings were observed: utilisation of complex co-isolation methods was not need for co-analysis of RNA and DNA; six highly discriminative miRNA markers were identified for miRNA analysis: blood (miR-451 and miR-194); saliva (miR-205); vaginal material (miR-224 and miR-335) and semen (miR-891a). In terms of casework applications, microRNA analysis showed potential for greater sensitivity than current enzymatic methods with the use of appropriate reference gene; species specificity was observed for reference gene RNU44; sample stability was observed in 1-yr bloodstains with miR-451 and RNU44 and successful resolution of major and minor components was achieved.

Megaselia scalaris (Diptera, Phoridae) is a common species found amongst indoor and outdoor crime scenes and plays an important role in the decomposition of human remains and can be used following the forensic entomology approach for the estimation of the post mortem interval particularly in indoor cases. Several questions concerning the biology and the chronobiology of this species remain open. Circadian clocks have evolved to synchronize physiology, metabolism and behaviour to the 24-h geophysical cycles of the Earth. The understanding of the circadian clock mechanism is a crucial element of forensic entomology because it is able to control routines such as feeding, mating, ovipositing or emergence times. To describe the behaviour and the potential role that the circadian clock may have on both the locomotor activity and emergence times of the M.scalaris, using Trikinetics technology, used previously in Drosophilia studies allows for factual data rather than observational data seen in many journals. The activity rhythms of M.scalaris were monitored using light/dark photoperiods at 20 °C. Males and females both demonstrate that there are significant differences between dark and light conditions and further results establish that the flies are both diurnal and nocturnal in activity. The pupa emergence shows that there are different rhythms during full darkness conditions and light/dark conditions. In addition our experiments demonstrated that the activity of this species is clock regulated. Differences in locomotor activity between male and female flies were observed in the absence of food in continuous dark (DD), in contrast the activity of the two sexes don’t differ in continuous light (LL) or in presence of food both in DD and in LL conditions. Cold White, Blue, Green, Red and Yellow lights were used to test the light attractiveness. Males and females show different behaviour. In contrast females seem to be attracted to red light and they don’t present any directional behaviour under other light. Colonisation of carrion by insects allow for the post mortem interval (PMI) to be determined. However it is thought by some, that flies are not active during the night time period and therefore are not able to oviposit during this time. To put that into a forensic context, if eggs were located on a cadaver, the conclusion would be that death occurred during the previous day or before. Determining nocturnal oviposition in forensically important flies is of fundamental importance so that the PMI can be determined correctly by the forensic entomologist. Our experiments have demonstrated that M.scalaris were able to oviposit in dark conditions during the night. Insects colonise a cadaver in a predictable pattern otherwise known as the succession. Succession patterns may vary due to intrinsic and environmental factors, for example, has the cadaver been buried or is it located above ground. Colonisation in buried remains depend on the slower decomposition rate of buried bodies, reduced dispersion of the decomposition odours but as well the reduced accessibility to the body. Phoridae are commonly found amongst the entomofauna of exhumed bodies or coffins. The phorid M.scalaris has been reported as being able to dig up to 6 feet. Little information is available about the kind of soil this fly is able to dig through to reach a cadaver; two different kinds of soil were investigated: sand and sandy loam garden soil. The results showed that M.scalaris was able to excavate garden soil but not sand. Insect development rate is mainly temperature dependent, although other parameters like photoperiod, overcrowding and food availability can affect the developments. In addition several studies demonstrated that drugs and other chemicals can affect the growth of larvae, feeding on the dead body, leading to Inc.orrect mPMI estimations. Amitriptyline is a commonly used antidepressant in cases of major depressive disorder. It is a tricyclic molecule absorbed in the gastrointestinal tract and metabolized into the liver. This molecule shows a high toxicity results in cases of overdose. Studies on the effect of Amitriptyline on insect development and accumulation/excretion have been performed in the 1990’s on Parasarcophaga ruficornis (Diptera: Sarcophagidae) and on Calliphora vicina (Diptera: Calliphoridae) whereas no data are available for other taxa. The results of these studies demonstrated the non-effect of the molecule on the growth rate. In the same years Amitriptyline and derivates have been isolated from empty puparia of Megaselia scalaris and from skin and faecal material of Dermestes maculatus (Coleoptera: Dermestidae) collected from a mummified body in New England. The aim of our study was to investigate the effect that Amitriptyline, often found on cadavers, may have on the development of Megaselia scalaris. Our experiment showed that Amitriptyline had no effect on the size but saw a decrease in the developmental time of M.scalaris, so the mPMI estimation can be affected if based on the larval size and not on the complete development. The results reported and discussed in this thesis improve the knowledge about the biology of M.scalaris and its applicability in the forensic context.