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Fingermarks are one of the most important and frequently encountered pieces of evidence in a crime scene. Ballistic material may also be recovered from a crime scene where firearms have been involved. The current recovery rate of identifiable fingermarks on ballistic evidence is quite low. The study herein aims to improve the knowledge base in relation to the enhancement of fingermarks on ballistic surfaces by employing various fingermark enhancement techniques that have been underutilised, while also using Gas Chromatography - Mass Spectrometry and a new fingermark deposition protocol to further strengthen our understanding of mark enhancement. A quick and cost-effective Gun Blue protocol with exceptional results on unfired ballistic material that had been exposed to a variety of environmental conditions and some well enhanced fingermarks (from various donors) on cartridges fired by different firearms is studied and proposed as a routine police casework technique. Vacuum metal deposition, a technique that was mostly visited for enhancing marks on plastic surfaces, is revisited for mark enhancement on ballistic material. The results of 2 different studies with different donor pools, showcase the suitability of the technique for brass surfaces and fired brass cartridge cases with a wide range of donors (20), while also being effective on older fingermarks (2 months old). Our results show the potential of VMD to be a used in police routine casework, when the surface in question is brass. The use of Gas Chromatography - Mass Spectrometry lead to the identification and quantification of compounds that are able to withstand the extreme conditions of firing, and thus providing information on which fingermark enhancement methods would be the best candidates for fired cartridge cases. Squalene, palmitic acid and cholesterol were the compounds that were most consistently present in the fingermark samples, while also being less affected by the time elapsed after deposition. Our findings in this chapter explain the favourable results Gun Blue enhancement generated on old fingermark samples. An artificial fingermark was created as a way to generate reproducible fingermarks by loading the fake fingermark with a precise amount of compounds found in fingermarks prior to each deposition. Our preliminary results demonstrate the additional advantage of this protocol, which is the potential it has to pinpoint, which compounds facilitate fingermark enhancement for different development methods. This could result in a better understanding of all fingermark enhancement methods and therefore could lead to improved recovery rates of fingermarks.

Gunshot residue (GSR) mixture consists of partially burned particles of propellant and characteristic particles of elements originating from the primer, bullet, propellant and some additives in the propellant. Since Harrison and Gillory [1] drew forensic scientists’ attention to the fact that GSR contained trace amounts of inorganic compounds such as lead, barium and antimony, a number of analytical techniques have been tested trying to find and establish sensitive, selective and reliable methods to identify and analyse gunshot residues. The standard procedure for the analysis of gunshot residues involves imaging these small metallic particles using scanning electron microscopy (SEM) and subsequent compositional analysis using Energy Dispersive X-ray Analysis (EDX). This study focuses on the analysis organic compounds in GSR. It is motivated by the increasing need to overcome the problems with the analysis of lead-free ammunitions. A comprehensive literature review was performed in order to determine the most commonly encountered organic compounds in GSR. These compounds include diphenylamine, methylcentralite, ethylcentralite, nitroglycerine, 2-nitrodiphenylamine and 4-nitrodiphenylamine. It has been clearly demonstrated using standard materials and appropriate calibration curves that gas chromatograph and mass spectrometry (GC/MS) is capable of providing limits of detection that are consistent with the concentrations of the key organic constituents found in gunshot residues. Furthermore, we have demonstrated that the relative concentrations of seven key components can be used to provide branding information on the shotgun cartridges. A strong relationship was found between the chemical composition of fired and unfired powder. Therefore, it is possible to differentiate between two ammunition brands through the analysis of the organic constituents. Traditional fingerprint powders such as titanium dioxide, aluminium, carbon black, iron oxide, lycopodium spores and rosin are used to enhance fingerprint left at the scene of crime. More recently nanoparticles have been demonstrated to be highly effective for the enhancement of the fingerprints [2]. Silica nano-particulates of defined size and shape were synthesised and functionalised with two different functional groups (phenyl and long chain hydrocarbon) using a Tri- phasic Reverse Emulsion (TPRE) method. These nano-particulates were characterised using scan electron microscope (SEM), transmission electron microscopy (TEM), elemental analysis, particles size analyser, BET surface area and solid-state nuclear magnetic resonance (NMR) spectroscopy. These powders were used as an effective agent to visualise latent fingerprints on different surfaces. Furthermore, they have been utilised to absorb any organic materials within the fingerprint from the discharged of weapon. Analyses of the adsorbed organic residues were performed using GC/MS and Raman spectroscopy. The results showed that the synthesised silica nano-particulate fingerprint powder gave better result in term of their ability to absorb organic materials in GSR and enhance the visualisation of the latent fingerprint compared to a single commercial powder.

A series of core and core-shell nanoparticles with superparamagnetic properties were synthesised and surface functionalised using three different amino-silanes by a chemical conjugation method. The functionalised nanoparticles were characterised and further modified by chemical conjugation with two different classes of bio-molecules; (i) enzymes and (ii) single stranded DNA primers. The resultant nanoparticles (nano-bio conjugates) were used for applications in (i) enzyme catalysis and (ii) bio-separation / bio-sensing. Magnetite and amorphous silica-coated core-shell nanoparticles were synthesised on both small (5 g) and large (20 g) scales and were characterised using transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area measurement and vibrating sample magnetometry (VSM). Silica-coated core-shell nanoparticles were functionalised by silanisation with three different aminosilanes [3-aminopropyl tri-ethoxysilane (APTS), 3-aminopropyl di-ethoxymethylsilane (APDS) and 3-aminopropyl mono-ethoxydimethylsilane (APMS)] and two different methods: water (classical method) or a Tri-phasic Reverse Emulsion (TPRE) using toluene and a surfactant (Triton X-100). It was observed that the materials prepared using the TPRE method produced higher surface amine density values on average. The first application involved bio-catalysis where lipases [Pseudomonas Fluorescens lipase (PFL) and Candida Rugosa lipase (CRL)] were chemically conjugated (covalently linked) via glutaraldehyde-modification onto the amino-functionalised nanoparticles for applications such as: (i) hydrolysis of p-nitrophenyl palmitate to produce palmitic acid and p-nitrophenol (model reaction), (ii) transesterification of ethyl butyrate with n-butanol to produce butyl butyrate and (iii) partial and selective hydrolysis of cis-3,5-diacetoxy-1-cyclopentene to produce pharmaceutically important and expensive chiral intermediate molecules. Various reaction parameters such as (a) water concentration in a bi-phasic solvent mixture and (b) temperature were investigated to determine the optimum conditions. All reactions were carried out using free lipases and the physically adsorbed lipases in order to compare the performance with chemically conjugated nano-biomaterials. It was observed from the bio-catalytic reaction (i) that the conversion values given by lipase-immobilised materials were comparable to those given by free lipases with the added advantage of being re-usable for further catalytic cycles. PFL-immobilised nanoparticles were shown to be more effective catalysts than CRL-immobilised materials. In the bio- catalytic reaction (ii), Lipase-immobilised materials were shown to exhibit reasonable conversion values (maximum 53%) along with easy separability by one-step magnetic separation from the reaction mixture and re-usability. Finally, in the bio-catalytic reaction (iii), lipase-immobilised materials were shown to give lower total conversion values compared to free enzymes, but a higher proportion of desired products [(1S,4R)-cis-4-acetoxy-2-cyclopenten-1-ol and (1R,4S)-cis-4-acetoxy-2-cyclopenten-1-ol]. PFL (both free and immobilised) materials were shown to give higher conversion and enantioselectivity towards the desired (1S,4R)-enantiomer (93-100% ee) than CRL materials (30-40% ee). The second application involved bio-separation and bio-sensing where 5ʹ-NH2-modified oligonucleotide sequences specific to either Listeria Monocytogenes (LM) or Escherichia Coli (EC) were immobilised onto the surface of glutaraldehyde modified nanoparticles to assess the specific capture and enhance the sensitivity of detection of pathogenic bacterial DNAs from food samples. Firstly, the oligonucleotide-grafted nanoparticles were used in a hybrid capture assay (model assay) at UCLan using specific single stranded DNA primers of our interest followed by the application in real food samples at Q-Bioanalytic GmbH, Germany. Capture of the complementary sequences was reasonably high (48-70% for LM-specific materials and 48-55% for EC-specific materials) when calculated as a molar ratio of conjugated oligonucleotides to complementary oligonucleotides captured. Specific capture was determined to be 33-52% for LM-specific oligonucleotide-grafted nano-materials and 59-60% for EC-specific oligonucleotide-grafted nano-materials. Dehybridisation of captured sequences was shown to be efficient for all oligonucleotide-grafted materials (72-97% for LM-specific materials and 86-87% for EC-specific materials), indicating that the materials were ready for real applications using food matrices at Q-Bioanalytic GmbH, Germany. Nucleic acid DNA was extracted from a real food sample inoculated with either LM or EC and the extracted DNA was used for specific capture using the oligonucleotide-grafted materials tested at UCLan. Dehybridised oligonucleotides were amplified and analysed using quantitative real-time PCR (qPCR). The results showed that using a one-step hybrid capture assay, LM-specific oligonucleotide-grafted materials were successful at detecting LM from an undiluted solution of LM only and from a 1:1 mixture of LM and EC. Using a two-step assay where the forward and reverse oligonucleotide-grafted materials were applied for capture separately, only EC-specific materials were successful for the detection of EC from an undiluted solution, and also from a 1:1 mixture of LM and EC.

The ability to adapt to changing environments is essential for survival. Bacteria have developed sophisticated means by which they sense and respond to stresses imposed by changes in the environment. Escherichia coli (E. coli) have served as a model organism for studies in molecular genetics and physiology since the 1960s. I have undertaken this study and address three outstanding questions. Firstly, the involvement of morphogene bolA and RNA polymerase sigma factor (rpoS) in biofilm formation. Secondly, the effect on respiratory activity of E. coli in presence and absence of these two genes and thirdly, the adherence pattern and formation of biofilm by E. coli on stainless steel, polypropylene and silicon surfaces under various stress-induced conditions. Bacterial biofilms are structural assemblages of microbial cells that encase themselves in a protective self produced matrix and irreversibly attach to surface. Their intense resistance to antibiotic and various environmental stresses has implicated them as playing a possible role in the pathogenesis of many chronic diseases. Although, the role of rpoS and bolA genes in long term stationary phase growth conditions and their response to it is now well-known, their objective presence and importance in short term response to different environmental cues which may lead to biofilm formation remains unknown. The rpoS gene encodes a stationary phase specific sigma factor of RNA polymerase and is a key regulator of E. coli stationary phase responses. It has been experiential under laboratory conditions that gene expression is induced by stressful environmental conditions and certain metabolic intermediates. Various stress environments were employed both in planktonic and biofilm phases to examine the sudden response of rpoS against different environmental conditions. However, it was observed that sudden rpoS response varies from stress to stress conditions. The gene bolA has been shown to trigger the formation of round cells when over expressed in stationary phase. From this research, it is concluded that bolA is not only confined to stationary phase, it also involves in biofilm formation under stress environments and essential for normal cell morphology. It also plays a major role in respiration and attachment of E. coli under diverse environmental stress surroundings. The main objective of this study was to understand the impact of heat, cold, acid and hydrogen peroxide on E. coli K-12 MG1655 and its stress response in presence and absence of rpoS and bolA genes. E. coli cells were exposed to sub-lethal levels of each stress for 15 minutes in both planktonic and biofilm phases and post-stress response i.e. gene expression level was evaluated. A real-time reverse transcription polymerase chain reaction (RT-PCR) assay, using the Applied Biosystems 7500™ real-time cycler, was developed for the purpose of this investigation of rpoS and bolA genes transcription. The assay was used specifically to quantify rpoS and bolA mRNA levels; however the method can readily be applied to the study of other E. coli genes. The method was uniquely applied to the investigation of these two genes throughout the growth cycle of E. coli in planktonic and biofilm phase in LB broth, in order to ascertain the patterns of expression for these genes. Scanning electron microscopy (SEM) was used for direct examining the cell attachment and biofilm formation on various surfaces under different stress conditions. In summary, this thesis embodies research investigating the role of rpoS and bolA genes in E. coli K-12 MG1655 biofilm formation and provides further evidence, that bacterial biofilms play a major role in resistance to various environmental cues.

Heat shock protein 90 (Hsp90), a highly conserved molecular chaperone, has been proposed to play a vital role in tumorigenesis. Hsp90 has two isoforms, of which Hsp90α is the major isoform of the Hsp90 complex and has an inducible expression profile. The molecular chaperone Hsp90α has been recognized in different cancers and it is implicated to play a role in cell cycle progression, apoptosis, regulates invasion, angiogenesis and metastasis. It is being recognized as a promising target in cancer treatment. Previous studies in our laboratory have demonstrated hsp90α expression in both primary glioma tissue and cell lines, but not in normal healthy brain tissues and cell lines. Enhanced chemosensitivity was observed upon specific inhibition of hsp90α expression by siRNA, suggesting that inhibiting hsp90α expression could possibly be a favourable therapeutic approach compared to conventional chemotherapies. In this novel study, Hsp90 was inhibited by either treatment with 17AAG or shRNA oligonucleotide targeting hsp90α (shhsp90α) in the U87-MG glioma cell line. The inhibition profile of Hsp90α was observed at the protein levels in control and treated cells by FACS analysis (quantitative) using a flow cytometer and Hsp90α ELISA kit. The results demonstrated a significant reduction of Hsp90α protein levels post treatment with 17AAG and shhsp90α. The activity of Hsp90α was assayed by quantifying the levels of Akt/PKB in the samples. Significant reductions (>50 %) of Akt/PKB levels were observed post hsp90α inhibition. Cell cycle analysis carried out reported S and G2 phase arrest, post Hsp90 inhibition by either 17AAG or shhsp90α. Interestingly, it was reported that 17AAG shows a better silencing profile compared to shhsp90α. To analyse the downstream effects of Hsp90 inhibition and to determine the client proteins affected, proteomic analysis was performed. Proteomic analysis identified several proteins which were either upregulated/downregulated post Hsp90 inhibition. IPA analysis further identified “cancer” as the top network significantly transformed post Hsp90 inhibition. Upregulated proteins include Hsp70 family members, Hsp27 and gp96, thereby suggesting the role of Hsp90 co-chaperones in compensating for Hsp90 function post Hsp90 inhibition. Moreover, members of the glycolysis/glucogenesis pathway were also upregulated, demonstrating increased dependency on glycolysis for energy supply by the treated glioma cells. Considering Hsp70 and its role in anti-apoptosis, it was postulated that a combination therapy involving a multi-target approach could be carried out. Subsequently, inhibition of both Hsp90 and Hsp70 in U87-MG glioma cell line was carried out resulting in 60 % cell death along with S and G2 phase arrest. Thus, in the effective treatment of glioma, the inhibition of multiple targets needs to be taken into consideration. Conclusion: It can be thus concluded that, combination therapy involving silencing of Hsp90 and Hsp70 could be of possible significance in glioma therapy.

Undifferentiated cancer stem cells (CSCs) with their unique potential of self-renewal and multi-lineage differentiation fuel tumour growth and relapse. Efficacy of glioma therapy can be considerably improved if the target is focused towards successful identification and elimination of CSCs. The aim of this research lies in defining specific and selective marker(s) to isolate glioma stem cells, to explore the differentiation state of brain tumour cells and to determine the protein profile changes that assist tumour cells to sustain stem cell-like characteristics. The three stem cell-related protein (CD133, Oct4-A and BMP3) expressions were investigated in control, hypoxic and serum-deprived U87-MG cells in order to shed light on the influence the micro-environment has in generating stem cells. Hypoxia offered a rapid state of undifferentiation as compared to serum deprivation by expressing a basal level of CD133 protein, a designated stem cell marker. Subsequent measurements of chemosensitivity and cell cycle analysis under undifferentiation conditions added to the cytotoxic potential of Taxol and showed an enhanced sensitivity of serum-deprived cells towards chemotherapeutic drugs. Moreover, proteomic analysis produced a wide dataset, depicting the changes that occur at the proteomic level in the differentiated and undifferentiated U87-MG cells. With ingenuity pathway analysis (IPA), human protein research database (HPRD) and the literature review, several proteins were proposed to be tested as potential biomarkers. They included Uracil DNA glycosylase (UDG), Phosphoglycerate kinase 1 (PGK1), Heterogeneous nuclear riboprotein K (HNRNPK) and moesin that can be used as differentiated markers for glioma cells. Vimentin, Eukaryotic translation initiation factor 4e (EIF4e), Casein kinase II alpha 1 (CSNK2A1) should be further investigated to study their precise role in gliomagenesis. Laminin binding protein associated with Integrin α6β1 and BMP2 should also be explored as a potential biomarker for isolation of glioma stem cells. This novel study envelops diverse aspects related to CSCs such as biomarkers, stem cell niche, chemoresistance, cell cycle and proteomics and also suggests the existence of two sub-types of CSCs within glioma population. It can be concluded that the finding thus obtained may be a step in the right direction in helping treat brain tumours.

Chromium(VI) is a reactive and highly toxic pollutant species which is present in certain industrial effluent streams as well as sea water and polluted ground water. Chromium(III), however, is relatively inert and less toxic. Conventional methods used to eliminate Cr(VI) from aqueous phase include its reduction to Cr(III) at acidic pH by reaction with strong reducing agents such as thiosulphate, FeSO4 and SO2, followed by precipitation as hydroxide in alkaline media. However, this procedure is not suitable for Cr(VI) elimination in dilute aqueous solutions. Thus, semiconductor photocatalysis has been studied as a possible alternative. Photocatalysis is the process of using light to promote catalysis of reactions and normally involves the photoexcitation of a semiconductor catalyst. During photocatalysis, light of a wavelength corresponding to an energy greater than that of the band gap, Eg, of the material is incident on the catalyst, resulting in electrons being excited from the semiconductor valence band to its conduction band. These electrons can then reduce the Cr(VI) to Cr(III). The semi-conductor used consists of nanoparticulate iron oxide embedded in a clay matrix. Clays are micro-crystalline layered minerals. This gives rise to interlayer spaces in which the iron oxide is ‘grown’. The clay structure restricts the growth of the iron oxide, resulting in nano-particulate sized semiconductor particles. To monitor the changes in Cr(VI) concentration, a new, stable potentiometric method has been developed that involves the successful use of a gold electrode to measure Cr(VI) concentration, that has to date, not been reported elsewhere in literature. Results show that the nanocomposite does photo-reduce Cr(VI) to Cr(III) and does photo-oxidise ethanol. Modelling of the time dependence of the measured (photo-induced) potential has allowed for the extraction of key rate parameters for the Cr(VI) reduction process with a view to system optimisation.

Polyetheretherketone (PEEK) is a polymer with outstanding performance, particularly concerning temperature resistance, chemical resistance and mechanical characteristics. Literature shows a gap in the knowledge with regards to PEEK flammability and decomposition products. The aim of this thesis is to describe the decomposition and flammability behaviour of PEEK, in order to develop new fire safe PEEK-based materials. By relating the measured thermal decomposition behaviour and changes in physical properties of PEEK materials to their performance in standard flammability tests, the dependence of these tests has been investigated with regards to orientation, thickness, presence of fillers, moisture absorption and absorption of infrared radiation. This understanding can inform the development of modified PEEK materials with enhanced fire safety. Various industry standard tests have been utilised to examine PEEK such as the Cone Calorimeter (ISO 5660), UL-94 (EN 60695-10-11), Limiting Oxygen Index (LOI), Thermogravimetric Analysis (TGA) in both air and inert atmospheres and the Small Flame Ignitability Test (ISO 11925). PEEK decomposition has been investigated using Thermogravimetric Analysis (TGA), Simultaneous Thermal Analysis coupled with Fourier Transform Infrared (STA-FTIR) and Pyrolysis Gas Chromatography coupled with Mass Spectrometry (pyGC/MS). Residue analysis has been carried out using Diamond Attenuated Total Reflectance coupled with Fourier Transform Infrared (dATR-FTIR), Solid State Nuclear Magnetic Resonance (MAS-NMR) and Scanning Electron Microscopy coupled with Electron Dispersive X-ray Analysis (SEM-EDX). Thermal analysis shows a rapid mass loss around 580°C followed by a slower mass loss of the resultant char. The stages of decomposition have been investigated by using FTIR and NMR on the condensed phase residues. Samples subjected to various temperature regimes have been observed in the dATR-FTIR and MAS-NMR and the results shows differences in the structures of the residue during decomposition. Generally, filled PEEK materials (with glass fibre, carbon fibre and talc) tend to have lower flammability in the Cone Calorimeter with a longer time to ignition and a lower peak heat release rate compared to the unfilled materials. The same is true in the LOI, where filled materials give a higher oxygen index, and in the UL-94 test where shorter burn times are recorded. PEEK shows inconsistent behaviour in some flammability tests, possibly due to the critical heat flux for ignition of PEEK being so close to the heat fluxes employed in many industry standard tests. The presence of moisture within the samples also reduces the time to ignition of PEEK in the Cone Calorimeter and increases the burning time in the UL-94, possibly due to the formation of a foamed sample close to the melting temperature of the polymer.