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Over the last forty years the steady use of radical reactions as the key steps in syntheses has increased. The most commonly used radical reagent is tributyl tinhydride. However such tin based radical reagents are toxic and often contaminate the product as they are difficult to remove. As an alternative to these tin reagents, a novel NaBH4/U.V. system was developed. This system was successfully used to effect the radical reduction of various aromatic halides. In light of these results it was thought that other useful transformations such as C-C bond formation could be achieved. Radical cyclisation onto unsaturated bonds, halogen atom transfers radical cyclisation (HATRC) and 1-5 hydrogen atom translocations were explored. This, 1-5 hydrogen atom translocations, methodology has been successfully applied to the synthesis of the spirocyclic natural products (±) horsfiline and coerulescine. With this success the use of the NaBH4/U.V. system on pyridine substrates was explored. Unfortunately this was not achieved with our current understanding of this reaction. However the use of tributylgernamium hydride, which is considered a ‘green’ radical reagent when compared to tin based reagents, proved successful. The novel application of this reagent in the 1-5 hydrogen atom transfer reaction on pyridine substrates was successfully demonstrated. Its use was successfully employed in the synthesis of a pyridine based bioisostere derivative of horsfiline.

The main aim of this thesis is to analyse and explore the philosophical justifications for freedom of speech during the nineteenth century and their application as political praxis. In this work, specific types of free speech argument are identified and examined in the light of the ideological stance of those who sought to argue for freedom of speech, primarily from key ideological perspectives of the nineteenth century, utilitarianism, liberalism and socialism. Initially three types of free speech argument are identified: the accountability argument, the liberty argument and the truth argument. However, on an inspection of socialist arguments for freedom of speech, the author suggests that a fourth sufficiently distinct type of free speech argument is present, particularly within the more mature works of socialist radicals and agitators. Though the arguments for freedom of speech overlap within different ideological and historical contexts, a case is made for a relatively distinct type of free speech argument within the socialist political praxis of free speech. Furthermore, in examining key political and philosophical texts, and an analysis of the free speech arguments in nineteenth century political pamphlets and newspapers, the argument is made that in order to gain a thorough understanding of political history and philosophy a holistic approach should be adopted, one which looks at ideas, context, history, artefact, and political praxis.

The problem with which this investigation is concerned is that of determining the properties of three radicals defined on an arbitrary ring and determining when these radicals coincide. The three radicals discussed are the nil radical, the Jacobsson radical, and the Brown-McCoy radical.

O ácido 3-indol acético (IAA), um conhecido hormônio de planta, e seu metabólito indol-3-carboxialdeído (ICA) têm sido envolvidos em várias patologias humanas como fenilcetonúria e doenças renais. A formação de espécies reativas de oxigênio e de estados eletronicamente excitados, como o oxigênio singlete (1O2) e a carbonila triplete (R2-C=O*), durante a oxidação aeróbica do IAA catalisada por peroxidase de raiz forte (HRP) têm sido relacionada com efeitos citotóxicos do IAA. Nossos resultados indicam aumento na formação de 8-oxo-7,8-dihidro-2\'desoxiguanosina (8-oxodGuo) após o tratamento da base com o sistema IAA/HRP/O2 in vitro, medido por um detector eletroquímico acoplado a um sistema de cromatografia líquida de alta performance (HPLC-EC). O tratamento de células de mamíferos (CV1-P e neutrófilos) com este sistema induziu o aumento na formação de 8-oxodGuo no DNA, assim como o aumento no nível de lipoperoxidação das células CV1-P quando comparadas ao controle. Detectamos a presença do adulo 1,N2-etenodesoxiguanosina em DNA de neutrófilos submetidos ao IAA. Portanto, neste estudo, apresentamos evidências de danos em biomoléculas promovidos pelo sistema IAA/HRP/O2. / Indole-3-acetic acid (IAA), a2 plant hormone, and its metabolite indole-3-carboxialdehyde (ICA) has been involved in several human pathologies as phenylketonuria and renal diseases. Formation of reactive oxygen species and electronically excited states as singlet oxygen (1O2) and triplet carbonyl (R2-C=O*), during the aerobic oxidation catalyzed by horseradish peroxidase (HRP) has been reported to be involved in the IAA cytotoxic effects. Our results show an increase in the formation of 8-oxo-7,8-dihydro-2\'deoxiguanosine (8-oxoxdGuo) after IAA/HRP/O2 system treatment in vitro as inferred from high performance liquid chromatography-electrochemical detection (HPLC-EC) measurements. Treatment of mammalian cells (CV1-P and neutrophils) with the system induces 8-oxoxdGuo formation in DNA as well increased levels of lipid peroxidation CV1-P cells when compared to controls. The 1,N2-etenodeoxyguanosine was detected in neutrophils DNA. Therefore, in this study, we presented evidence of biomolecule damage by IAA/HRP/O2 system.

by Wang, Wei Vivian. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 237-266). / ACKNOWLEDGEMENTS --- p.viii / SUMMARY --- p.ix / PUBLICATION --- p.xiv / STATEMENT OF ORIGINALITY --- p.xv / LIST OF ABBREVIATIONS --- p.xvi / Chapter CHAPTER 1 --- INTRODUCTION --- p.3 / Chapter 1.1 --- Preamble --- p.3 / Chapter 1.2 --- Free oxygen radicals --- p.7 / Chapter 1.2.1 --- Free oxygen radicals and mechanism of radical damage / Chapter 1.2.1.1 --- What is a free radical? / Chapter 1.2.1.2 --- Mechanism of free radical damage / Chapter 1.2.2 --- Detection and characterisation of free radical species / Chapter 1.2.2.1 --- Direct methods / Chapter 1.2.2.1.1 --- Electron spin resonance (ESR) spectroscopy / Chapter 1.2.2.1.2 --- Chemiluminescence / Chapter 1.2.2.2 --- Indirect methods / Chapter 1.2.2.2.1 --- Lipid peroxidation / Chapter 1.2.2.2.2 --- Protein and DNA oxidation / Chapter 1.2.2.2.3 --- Purine and pyrimidine metabolites / Chapter 1.2.3 --- Free oxygen radicals and major disease / Chapter 1.2.4 --- Oxygen-derived free radicals and fetal hypoxia / Chapter 1.3 --- Acid-base status in cord blood --- p.41 / Chapter 1.3.1 --- Correlation between obstetric clinical events and cord blood acid-base / Chapter 1.3.2 --- Practical implications of cord blood acid-base studies / Chapter 1.4 --- Intrapartum cardiotocography (CTG) analysis --- p.58 / Chapter 1.4.1 --- Base line / Chapter 1.4.1.1 --- Baseline rate / Chapter 1.4.1.2 --- Baseline variability / Chapter 1.4.2 --- Accelerations and decelerations / Chapter 1.4.3 --- Fetal outcome of labour / Chapter 1.4.3.1 --- Fetal heart rate (FHR) changes during labour / Chapter 1.4.3.2 --- Acidaemia during labour / Chapter 1.4.4 --- Computerised analysis of cardiotocogram / Chapter 1.5 --- Intrapartum complications --- p.83 / Chapter 1.5.1 --- Meconium stained amniotic fluid / Chapter 1.5.2 --- Nuchal cord entanglement / Chapter 1.5.3 --- Prolonged 1st and 2nd stage of labour / Chapter 1.6 --- Objectives of project --- p.93 / Chapter CHAPTER 2 --- MATERIALS AND METHODS --- p.98 / Chapter 2.1 --- Materials --- p.98 / Chapter 2.1.1 --- Clinical materials / Chapter 2.1.2 --- Chemicals and reagents / Chapter 2.1.2.1 --- The measurement of malondialdehyde (MDA) / Chapter 2.1.2.2 --- The measurement of organic hydroperoxides (OHP) / Chapter 2.1.2.3 --- The measurement of purine and pyrimidine metabolites / Chapter 2.1.3 --- Equipment / Chapter 2.1.3.1 --- Fetal monitor / Chapter 2.1.3.2 --- Fetal heart rate analysis system / Chapter 2.1.3.3 --- Blood gas analyser / Chapter 2.1.3.4 --- UV-VIS Spectrophotometer / Chapter 2.1.3.5 --- Fluorescence Spectrophotometer / Chapter 2.1.3.6 --- High Performance Liquid Chromatography (HPLC) / Chapter 2.2 --- Investigation Methods --- p.105 / Chapter 2.2.1 --- Blood gas / Chapter 2.2.2 --- Lipid peroxidation in umbilical cord blood / Chapter 2.2.2.1 --- The measurement of MDA / Chapter 2.2.2.2 --- The measurement of OHP / Chapter 2.2.3 --- Purine and pyrimidine metabolites in umbilical cord blood / Chapter 2.2.4 --- Computer analysis of CTG / Chapter 2.2.4.1 --- Data and signal processing / Chapter 2.2.4.2 --- The algorithm / Chapter 2.3 --- Statistical analysis --- p.112 / Chapter CHAPTER 3 --- RESULTS --- p.116 / Chapter 3.1 --- Umbilical blood pH and gas measurements --- p.118 / Chapter 3.2 --- Lipid peroxidation in cord blood plasma --- p.121 / Chapter 3.2.1 --- Validation of assay / Chapter 3.2.1.1 --- Performance characteristics of the MDA assay / Chapter 3.2.1.2 --- Performance characteristics of the OHP assay / Chapter 3.2.2 --- "Inter-relationship among MDA, OHP and acid-base status" / Chapter 3.3 --- Nucleotide metabolites in cord blood plasma --- p.142 / Chapter 3.3.1 --- Calibration of assay / Chapter 3.3.2 --- Inter-relationship among nucleotides and acid-base status / Chapter 3.4 --- Analysis of FHR patterns --- p.150 / Chapter 3.4.1 --- Umbilical blood gas and CTG analysis / Chapter 3.4.2 --- Biochemical parameters and CTG analysis / Chapter 3.5 --- "Relations of umbilical arterial blood pH and gas, lipid peroxidation, purine or pyrimidine metabolites and FHR patterns with intrapartum complications" --- p.166 / Chapter 3.5.1 --- Meconium stained amniotic fluid / Chapter 3.5.1.1 --- Clinical features / Chapter 3.5.1.2 --- Relationship between meconium stained amniotic fluid and biochemical parameters / Chapter 3.5.1.3 --- Relationship between meconium stained amniotic fluid and FHR patterns / Chapter 3.5.2 --- Nuchal cord / Chapter 3.5.2.1 --- Clinical features / Chapter 3.5.2.2 --- Relationship between nuchal cord and biochemical parameters / Chapter 3.5.2.3 --- Relationship between nuchal cord and FHR patterns / Chapter 3.5.3 --- The length of second stage of labour / Chapter 3.5.3.1 --- Clinical features / Chapter 3.5.3.2 --- Relationship between the length of second stage and acidaemia or FHR patterns / Chapter 3.5.4 --- Apgar scores / Chapter 3.5.4.1 --- Clinical features / Chapter 3.5.4.2 --- Relationship between Apgar scores and biochemical parameters / Chapter 3.5.4.3 --- Relationship between Apgar scores and FHR patterns / Chapter 3.5.4.4 --- "Relationship between Apgar scores and nuchal cord, meconium or second stage of labour" / Chapter CHAPTER 4 --- DISCUSSION --- p.189 / Chapter 4.1 --- Blood pH and gas in fetal asphyxia --- p.189 / Chapter 4.2 --- Lipid peroxidation in cord blood at birth --- p.194 / Chapter 4.2.1 --- Method for measurement of the cord plasma MDA / Chapter 4.2.2 --- Method for measurement of the cord plasma OHP / Chapter 4.2.3 --- Relationship between the fetal asphyxia and lipid peroxidation in cord plasma / Chapter 4.3 --- Purine and pyrimidine metabolites in cord blood at birth --- p.203 / Chapter 4.3.1 --- Limitations imposed by the tcchniqucs used / Chapter 4.3.2 --- Relationship between the fetal asphyxia and purine and pyrimidine metabolites in cord plasma / Chapter 4.4 --- Computerised analysis of CTG --- p.210 / Chapter 4.4.1 --- CTG patterns and cord blood acid base balance / Chapter 4.4.2 --- CTG patterns and cord blood biochemical parameters / Chapter 4.5 --- "Intrapartum complications 2,9" / Chapter 4.5.1 --- Meconium stained amniotic fluid / Chapter 4.5.2 --- Nuchal cord / Chapter 4.5.3 --- The length of second stage / Chapter 4.5.4 --- Apgar scores / Chapter CHAPTER 5 --- CONCLUSION --- p.233 / REFERENCES --- p.237

Ngai Lei-Ka. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 113-125). / Abstracts in English and Chinese. / List of Abbreviations --- p.ix / List of Tables --- p.x / List of Figures --- p.xii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Flavonoids --- p.1 / Chapter 1.1.1 --- The six major classes of flavonoids --- p.1 / Chapter 1.1.1.1 --- Flavonones --- p.1 / Chapter 1.1.1.2 --- Flavones --- p.2 / Chapter 1.1.1.3 --- Flavonols --- p.2 / Chapter 1.1.1.4 --- Isoflavonoids --- p.2 / Chapter 1.1.1.5 --- Anthocyanidins --- p.3 / Chapter 1.1.1.6 --- Flavans --- p.3 / Chapter 1.1.2 --- Structural variation of flavonoids --- p.3 / Chapter 1.1.3 --- The roles of flavonoids --- p.6 / Chapter 1.2 --- "Free radicals, oxidative stress and antioxidants" --- p.7 / Chapter 1.2.1 --- Oxidants and free radicals --- p.7 / Chapter 1.2.2 --- Lipid peroxidation (LPO) --- p.8 / Chapter 1.2.3 --- Oxidative stress and human diseases --- p.9 / Chapter 1.2.4 --- Role of food antioxidants --- p.10 / Chapter 1.2.5 --- Synthetic and natural food antioxidants --- p.11 / Chapter 1.3 --- Antioxidant activity of flavonoids --- p.12 / Chapter 1.4 --- Determination of antioxidant activity --- p.13 / Chapter 1.4.1 --- Trolox equivalent antioxidant capacity (TEAC) assay --- p.13 / Chapter 1.4.2 --- DPPH radical scavenging assay --- p.14 / Chapter 1.4.3 --- β-carotene bleaching assay --- p.15 / Chapter 1.5 --- Single cell gel electrophoresis assay (Comet assay) --- p.16 / Chapter 1.6 --- Determination of the genotoxicity --- p.18 / Chapter 1.7 --- Research objectives --- p.19 / Chapter 2 --- Materials and Methods --- p.26 / Chapter 2.1 --- Standards and reagents --- p.26 / Chapter 2.2 --- Sample Preparation --- p.26 / Chapter 2.3 --- Trolox equivalent antioxidant capacity (TEAC) assay --- p.27 / Chapter 2.4 --- DPPH´Ø radical scavenging assay --- p.28 / Chapter 2.5 --- β-carotene bleaching assay --- p.29 / Chapter 2.6 --- The comet assay --- p.30 / Chapter 2.6.1 --- Preparation of reagents --- p.31 / Chapter 2.6.2 --- Blood sample --- p.32 / Chapter 2.6.3 --- Optimal condition of comet assay --- p.32 / Chapter 2.6.3.1 --- Induction of DNA damage --- p.32 / Chapter 2.6.3.2 --- Antioxidant pre-treatment --- p.32 / Chapter 2.6.4 --- Hydrogen peroxide (H2O2) treatment --- p.32 / Chapter 2.6.4.1 --- Pre-incubation system --- p.32 / Chapter 2.6.4.2 --- Co-incubation system --- p.33 / Chapter 2.6.5 --- Slide preparation --- p.33 / Chapter 2.6.6 --- Cell lysis --- p.33 / Chapter 2.6.7 --- Alkaline treatment and electrophoresis --- p.34 / Chapter 2.6.8 --- Neutralization --- p.34 / Chapter 2.6.9 --- Quantification of DNA damage --- p.34 / Chapter 2.6.10 --- Cell viability analysis --- p.35 / Chapter 2.6.11 --- Statistical Analysis --- p.35 / Chapter 2.7 --- Mutatox® test --- p.36 / Chapter 2.8 --- Statistical analysis --- p.36 / Chapter 3 --- Result --- p.45 / Chapter 3.1 --- Determination of antioxidant activity using Trolox equivalent antioxidant capacity (TEAC) assay --- p.45 / Chapter 3.1.1 --- Trolox standard reference --- p.45 / Chapter 3.1.2 --- Antioxidant activity: ABTS´Ø+ scavenging capacity --- p.45 / Chapter 3.2 --- Evaluation of antioxidant activity using free radical scavenging assay --- p.46 / Chapter 3.2.1 --- Free radical scavenging abilities at 5 minutes --- p.46 / Chapter 3.2.2 --- Antiradical efficiency --- p.47 / Chapter 3.3 --- Evaluation of antioxidant activity using β-carotene bleaching assay --- p.47 / Chapter 3.3.1 --- Optimal incubation time --- p.47 / Chapter 3.2.2 --- Antioxidant activities on β-carotene bleaching assay --- p.47 / Chapter 3.4 --- Structure and antioxidant activities relationship (SAR) of flavonoids --- p.48 / Chapter 3.4.1 --- Effect of hydroxylation on the antioxidant activities of flavonoids --- p.48 / Chapter 3.4.1.1 --- Hydroxylation positions --- p.48 / Chapter 3.4.1.2 --- Polyhydroxylation --- p.48 / Chapter 3.4.2 --- Importance of B ring structure --- p.49 / Chapter 3.4.2.1 --- Increase hydroxylation in B ring --- p.49 / Chapter 3.4.2.2 --- The othro-dihydroxyl arranagement in B ring --- p.49 / Chapter 3.4.3 --- Importance of C ring structure --- p.50 / Chapter 3.4.3.1 --- The presence of a hydroxyl group at C3 --- p.50 / Chapter 3.4.3.2 --- The blockage of hydroxylation at C3 --- p.50 / Chapter 3.4.3.3 --- The presence of a double bond between C2 to C3 --- p.50 / Chapter 3.4.3.4 --- The presence of a carbonyl group at C4 --- p.50 / Chapter 3.4.3.5 --- The conjugation of a carbonyl at with a double bond between C2 to C3 --- p.51 / Chapter 3.4.4 --- Effect of glycosylation --- p.51 / Chapter 3.5 --- Evaluation of protective effects on DNA damage using comet assay --- p.51 / Chapter 3.5.1 --- Optimization of conditions fro the determination of H2O2-induced DNA damage --- p.52 / Chapter 3.5.1.1 --- H2O2 concentration & treatment temperature --- p.52 / Chapter 3.5.1.2 --- H2O2 treatment time --- p.52 / Chapter 3.5.1.3 --- Sample volume --- p.52 / Chapter 3.5.2 --- Protective effect of vitamin C on DNA damage --- p.53 / Chapter 3.5.3 --- Protective effect of selected flavonoids on DNA damage --- p.53 / Chapter 3.5.4 --- Structure and antioxidant activities relationship (SAR) of flavonoids in comet assay --- p.54 / Chapter 3.5.4.1 --- The importance of B ring structures --- p.54 / Chapter 3.5.4.2 --- The importance of C ring structures --- p.54 / Chapter 3.6 --- Evaluation of genotoxicity of flavonoids using Mutatox test --- p.55 / Chapter 4 --- Discussion --- p.96 / Chapter 4.1 --- Comparison of antioxidant activities between hydrophilic and lipophilic assays --- p.97 / Chapter 4.2 --- Structure and antioxidant activity relationship of flavonoids --- p.98 / Chapter 4.3 --- The comet assay --- p.103 / Chapter 4.4 --- Comparison of protective effect on DNA damage between pre-incubation and co-incubation systems --- p.105 / Chapter 4.5 --- Structure and protective effect of flavonoids in the comet assay --- p.106 / Chapter 4.6 --- Genotoxicity of flavonoids --- p.108 / Chapter 4.7 --- Significance and future works --- p.108 / Chapter 5 --- Conclusion --- p.111 / References --- p.113

Typescript (photocopy). / Digitized by Kansas Correctional Industries

This thesis describes an experimental study of elastic electron scattering from CF2 radicals, in the intermediate energy regime. Measurements of the absolute differential, integral and momentum transfer cross sections for CF2 are presented. These measurements were performed using a new crossed beam spectrometer, incorporating a supersonic gas source and normalised using a new technique, with both of these features being extensively developed as a major part of this study. The organisation of this thesis is as follows: A brief justification for this research is presented in Chapter 1, together with a review of the spectroscopy and electron collision cross sections which are currently available for the CF2 radical. The crossed beamed apparatus and experimental techniques used to perform the present cross section measurements are then described in detail in Chapter 2, and the theory behind the new normalisation technique is subsequently presented in Chapter 3. Results from the present study are given in Chapter 4. Firstly, differential cross sections measurements for stable molecules are presented, to validate the new normalisation method. Characterisation data for the dissociation dynamics of C2F4 into CF2 radicals are then presented and, finally, differential cross section measurements for the CF2 radical are explored. Where possible, the measured data for CF2 are compared against results from theoretical calculations and the implications of the present results are discussed. The major findings of this research are then summarised in Chapter 5, and directions for future research using the present apparatus are also discussed here. Finally, some additional findings from this research and calibration data for the current apparatus are given in the appendices.