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The present study has the following purposes: to provide a general description of work release in this country, to provide specific descriptions of the work release programs at two federal institutions, and to relate the descriptions of these programs to societal reactions to crime and theories of criminal etiology and epidemiology.

Dehiscence is a means by which some wild plants release their seeds. In Brassicas the mature fruit or 'pod', strictly a silique, releases seed by a sometimes explosive mechanism triggered by mechanical pressure and referred to as 'shatter'. This mechanism is a problem in Brassica crop plants and results in loss of seed, and hence loss of revenue, during harvesting. This problem is further compounded by the distribution of volunteers which contaminate future crops and the environment. The post-fertilisation development of the carpel wall of a number of Brassica species has been examined including, a range of Arabidopsis ecotypes and mutants, and fruits from two other Brassicas, Brassica napus and Brassica juncea, which exhibit differences in the dehiscence characteristic. These have been studied by a combination of cytological, cytochemical and molecular techniques. Following fertilisation, dehiscence zones form at the carpel margins, separating the carpel walls from the replum and forming two valves. Cells within the dehiscence zone exhibit reduced cellular cohesion due to breakdown of the middle lamella. Differentiation of the carpel wall layers results in a thickened exocarp, a senescing mesocarp, and modification of the endocarp layers in which the inner layer Enϸ lignifies whilst Enα collapses. It is proposed that the patterns of differentiation result in the development of the dehiscence mechanism. The dehiscence mechanism and pod 'shatter' is a result of; 1) weakening of valve attachment due to reduced cell cohesion in the dehiscence zone, and, 2) tensions which develop within the carpel walls due to desiccation and shrinkage of the mesocarp which is attached to a thickened, non-shrinking endocarp.The fruits from all of the Arabidopsis ecotypes examined exhibited a similar pattern of carpel wall development and similar dehiscence characteristics. Light microscopical examination of the fruits of Brassica napus and Brassica juncea which do not shatter as easily as those of Arabidopsis showed a different pattern of endocarp development in the post fertilised fruit. Enα tangential walls thickened considerably in the post-fertilised Brassica napus and Brassica juncea fruit, prior to the collapse of this cell layer. In Indian mustard, the Brassica juncea variety which had a non-shattering phenotype, the lignified walls of En6 were surrounded by a highly pectinised layer. This deposition of pectins confers more elasticity to the carpel walls, hence reducing the tensions which normally result in dehiscence and cause pod shatter. The model of the shattering and non-shattering phenotypes described in this study suggest a number of strategies which may be used to reduce the problems of pod shatter. These include modification of the separation layer to increase cellular cohesion, and modifications to the patterns of differentiation in the carpel wall to reduce the tensions which normally develop during fruit ripening.

Sustained concentrations of active compound were maintained in vitro and in vivo for an oral and a parenteral dosage form respectively. The vehicle of a oral dosage form was modified and the molecular structure of a parenteral dosage form was modified. An oral dosage form was tested in vitro using dissolution apparatus. A parenteral dosage form was tested in vivo using rats. A new oral suspension dosage form for acetylsalicylic acid was compared to two controlled release forms and two immediate release dosage forms which are currently commercially available. A parenteral thrombomodulin analogue conjugated to polyethylene glycol was compared to the unconjugated thrombomodulin analogue. In each case the goal was to maintain sustained concentrations of active compound. / Graduation date: 1991

The benefits of controlled release drug delivery are important to the pharmaceutical industry. With a controlled release device, local administration of a drug is possible and release profiles can be created that remain within therapeutic limits for prolonged periods. Made from biodegradable and bioerodable polymers, unwanted side effects and the need of return trips for treatment diminish. However, a usable device must be free of organic solvents normally used to dissolve large drug molecules. Many of these solvents are toxic themselves. Therefore, steps must be taken to either remove residual solvent from the final device or limit their use during synthesis. Ideally, it is desirable to remove the organic solvents from the process entirely. Supercritical carbon dioxide (scCO2) has been used as a replacement for these solvents. Carbon dioxide is inexpensive, environmentally acceptable, and safe for use in human consumables. However, many drug molecules have very low solubility in scCO2, resulting in extended polymer impregnation times. An organic co-solvent can be used to increase drug solubility, leading to a more efficient polymer impregnation. Using only a small amount of organic co-solvent, a single phase stream is possible that results in significantly increased solubility. This meets the original task of limiting organic solvents in the process and increases efficiency over scCO2 alone. This study uses supercritical carbon dioxide with ethanol as a co-solvent. Ethanol increases the solubility of β-estradiol in scCO2 for impregnation into the glassy polymer polyvinylpyrrolidone (PVPP). Experimental conditions cover a range of temperatures from 40 °C to 50 °C and pressure up to 2500 psi. The effect of polymer swelling time on the sorption process is also studied. A dual mode sorption model describes the sorption of drug into the glassy polymer, and a plug flow and stirred tank compartmental model predicts breakthrough profiles. The determined sorption parameters allow analysis of polymer conformation and suggest optimum impregnation conditions.

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Thesis (doctoral)--Ume̊a Universitet, 1982. / Extra t.p. with thesis statement inserted. eContent provider-neutral record in process. Description based on print version record. Includes bibliographies.