No description available.

Since Shakespeare was introduced to China at the beginning of the 20th Century, the Chinese have translated the English playwright's plays and performed them on the Chinese stage either in the form of spoken drama or the traditional Chinese opera. No matter which approach is chosen to perform the dramatist, it is an intercultural form in introducing him to the Chinese.

Since Shakespeare was introduced to China at the beginning of the 20th Century, the Chinese have translated the English playwright's plays and performed them on the Chinese stage either in the form of spoken drama or the traditional Chinese opera. No matter which approach is chosen to perform the dramatist, it is an intercultural form in introducing him to the Chinese.

No description available.

A study of the design and development of transversely excited atmospheric pressure carbon dioxide lasers has been carried out. Three lasers were constructed with output energies ranging from a few millijoules to several joules. Damage in transmitting output mirrors is one of the limiting factors in the development of high energy density carbon dioxide lasers. One form of damage in uncoated germanium components is characterised by regular patterns. A detailed examination of these damage patterns on several mirrors has been carried out using both optical and electron microscopy. A semi-quantitative physical model describing the damage structure formation is proposed, and good agreement with experimental observation is found. The thesis goes on to examine in depth particular aspects of the model with the object of making the analysis fully quantitative. The thesis concludes by preparing the necessary data base for quantitative computer modelling. A full description is prepared of the behaviour of all the relevant physical parameters characterising germanium from room temperature to melting point temperature (300K - 1210K). The technique adopted is to use a theoretical (or sometimes empirical) framew6rk within which to extrapolate from available published data into parameter ranges not hitherto available. For germanium, numerical values have been assigned to all relevant physical parameters (thermal, electrical and optical) over the full temperature range. The way is now open for computer simulation of. the interaction between laser radiation and germanium under a wide variety of circumstances. A significant refinement of the model describing damage structure has already occurred. When the magnitudes and temperature variation of Ε' and Ε" for germanium were established, the particular model behaviour of germanium suggested a generalised view of the behaviour of other materials. At the time of writing, the model is being adapted to account for the observations of other workers on a wide variety of other materials.

No description available.

The pharmacology of the rat adipocyte beta-adrenoceptor has been examined using radioligand binding techniques as well as analysis of biochemical and functional effector responses. The ligand binding properties of beta-adrenoceptors on isolated adipocyte membranes have been compared to those in rat lung and whole fat pad membranes. This study demonstrated that binding sites could be identified on adipocytes which had all the characteristics expected of beta-adrenoceptors. Furthermore, inhibition of binding by agents selective for beta, or beta2 adrenoceptors indicated that the receptor subtype present on adipocytes was predominantly beta1 whereas lung and whole fat pad membranes contained mainly beta2 Adrenoceptors. The characteristics of the beta-adrenoceptor mediating lipolysis have also been examined. Evidence is presented which showed that inhibition of lipolysis stimulated through beta-adrenoceptors was inhibited by selective beta-adrenoceptor antagonists with a lower potency than that expected at beta1 or beta2 adrenoceptors. This suggested that an atypical beta-adrenoceptor was responsible for mediating the lipolytic response. The apparently atypical beta-adrenoceptor has been further investigated by analysis of cAMP-accumulation in whole cells and adenylate cyclase activity in membranes. These studies confirmed the results from lipolysis studies where it was again shown that antagonists had low potencies. In addition, the stereospecificity displayed by antagonist isomers was lower to that expected at typical beta-adrenoceptors. In order to investigate whether typical beta1 and atypical beta-adrenoceptors could be separated, an irreversible beta-adrenoceptor antagonist has been used to selectively inhibit typical beta-adrenoceptors. The results demonstrated that whereas beta1 binding sites could be irreversibly blocked, the beta-adrenoceptor-stimulated adenylate cyclase activity was unaffected. This further suggested that the receptors identified by binding studies are not the same as those mediating the lipolytic response to catecholamines.

Following an introduction into areas of memory and anxiety, detailed critical reviews of both anxiety and diazepam effects in memory are presented. Although detrimental effects of arousal have been frequently observed, the effects of state anxiety have not been so systmatically studied. Furthermore, although the deleterious effect of diazepam has often been observed in memory performance, one would expect a facilitative effect with subject stratified for symptoms of high anxiety. The first two experiments investigated the effects of diazepam in anxious and nonanxious volunteers in two different memory paradigms. In these experiments, encoding in short term memory and retrieval from semantic memory were both adversely affected by anxiety, and diazepam ameliorated this effect under certain test conditions. It seemed possible that the use of another group of anxiolytic agents whose mainly peripheral mode of anxiolytic activity should mimic the centrally-mediated facilitative effect of the drug by indirectly reducing the feedback of peripheral stimuli towards the central state of anxiety. This was investigated in Experiment 3 using an identical procedure to Experiment 1. Oxprenolol did not facilitate the performance of anxious subjects which either indicated that the facilitative effects of diazepam may be affecting underlying mechanisms more directly, or that an absence of heightened autonomic activity in normal subjects was responsible for these results. Experiment 4 repeated the procedure of earlier experiments in order to examine the robustness of the anxiety difference, and although not replicated several methodological explanations were given. The remaining two experiments explored the possibility that the drug-anxiety interactions observed previously were directly attributable to differences in strategy usage, flexibility and preferences underlying the two anxiety groups. There was no direct evidence of differences between anxious and nonanxious subjects and alternative explanations for these anxiety differences were discussed.

No description available.

The aim of this programme was to design and synthesize triazinobenzimidazoles that are analogous to the antihypertensive agents, hydralazine and dihydralazine. Retrosynthetic analysis of these analogues showed that the key intermediates in the synthesis were the novel [1,2,4]triazino[4,5-a]benzimidazol-l-ones and the related 1,4-diones. Existing routes to this tricyclic ring system were either limited in scope or needed expensive starting materials. Therefore, a new synthetic route to these compounds was developed using the readily available 2-acylbenzimidazoles as starting materials. These acyl derivatives were converted to hydrazones, ethoxycarbonylhydrazones and benzimidazole-2-carboxylic acid ethoxycarbonylhydrazides. The substituted hydrazines were cyclized to the desired tricyclic lactam intermediates either thermally, or acylatively using ethyl chloroformate in pyridine. The versatility of these cyclization methods has been demonstrated by the synthesis of a variety of novel N-2 substituted [1,2,4]triazino[4,5-a]benzimidazol- 1-ones which may or may not have a substituent at C-4. In addition, it has been shown that these types of cyclizations provide a better route to existing triazinobenzimidazoles. Although attempts to chlorinate or thiate these lactams were unsuccessful, use of the dithio analogue of ethyl carbazate, methyl dithiocarbazate, afforded sulphur-containing hydrazones which were cyclized to the desired [1,2,4]triazino[4,5-a]benzimi dazole-1-thiones. Displacement of the enolized 1-thione by hydrazine produced the desired target molecules, 1-hydrazino- [1,2,4]triazino[4,5-a]benzimidazoles. In preliminary screening, these compounds exhibited in vivo vasodilatory activity. In an attempt to vary the 4-substituent of the tricyclic system further, the synthesis of a variety of modified 2-acylbenzimidazoles was undertaken. In particular, the structure and reactions of one of these modified ketones, 2-bromoacetylbenzimidazole, was investigated in an attempt to explain its bromination pattern. Other workers have suggested that the unusual bromination pattern of 2-acetyl and 2-bromoacetylbenzimidazole may arise from the influence of intramolecular hydrogen bonding between the imine proton and the carbonyl group. However, a computer-aided reinvestigation of this reaction has shown that a more plausible intermediate is an intramolecularly hydrogen bonded enol of the ketone. The synthesis of two novel triazepinobenzimidazole ring systems has been examined. The acylative-cyclization (ethyl chloroformate-pyridine) developed for the preparation of the novel triazines has been extended to the synthesis of the hitherto unknown [1,2,4]triazepino[4,5-a]benzimidazole ring system. A series of new 1,2-diacylbenzimidazoles were prepared as precursors to [1,2,5]triazepino[5,4-a]benzimidazoles. However, attempts to add hydrazine across the dicarbonyl groups gave only novel benzimidazole hydrazine or hydrazide derivatives instead of the desired triazepinobenzimidazoles. Many of the compounds described in this thesis have been screened for possible pharmacological activity.