Interfacial Properties of Amphiphilic Dendritic Polymers

The self-assembly behavior of arborescent polystyrene-graft-poly(ethylene oxide) copolymers (PS-g-PEO) at the air-water interface and the solubilization/release properties of arborescent polystyrene-graft-poly(2-vinylpyridine) (PS-g-P2VP) copolymers were investigated. These amphiphilic dendritic molecules are covalently bonded unimolecular micelles incorporating a highly branched hydrophobic polystyrene core surrounded by a hydrophilic poly(ethylene oxide) or poly(2-vinylpyridine) shell. Molecules of PS-g-PEO copolymers spontaneously formed supramolecular assemblies at the air-water interface. The type of superstructures formed was found to depend upon copolymer composition, while the level of association was more directly related to the branching density of the polymers. At low surface pressures the PEO segments apparently remained adsorbed on the water subphase, but desorbed into water at very high surface pressures, in the condensed monolayer state. Controlled degradation of the PEO chains with UV light greatly enhanced molecular association, resulting in the formation of either large clusters or long ribbon-like superstructures. The PS-g-P2VP copolymers were found to efficiently solubilize and release hydrophobic small molecules in aqueous media. The partition coefficient and solubilization capacity of the copolymers for hydrophobic polyaromatic hydrocarbons increased with the polystyrene content of the copolymers, while the rate of solubilization decreased with increasing branching functionality of the copolymers. The release profiles for two model drugs displayed an initial burst in release followed by gradual approach to equilibrium. The diffusion coefficients of the drugs in the micelles increased with the branching functionality and the generation number of the micelles, presumably due to increased electrostatic repulsions of the protonated vinylpyridine units

Interfacial Properties of Amphiphilic Dendritic Polymers

I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically to the public ii The self-assembly behavior of arborescent polystyrene-graft-poly(ethylene oxide) copolymers (PS-g-PEO) at the air-water interface and the solubilization/release properties of arborescent polystyrene-graft-poly(2-vinylpyridine) (PS-g-P2VP) copolymers were investigated. These amphiphilic dendritic molecules are covalently bonded unimolecular micelles incorporating a highly branched hydrophobic polystyrene core surrounded by a hydrophilic poly(ethylene oxide) or poly(2-vinylpyridine) shell. Molecules of PS-g-PEO copolymers spontaneously formed supramolecular assemblies at the air-water interface. The type of superstructures formed was found to depend upon copolymer composition, while the level of association was more directly related to the branching density of the polymers. At low surface pressures the PEO segments apparently remained adsorbed on the water subphase, but desorbed into water at very high surface pressures, in the condensed monolayer state. Controlled degradation of the PEO chains with UV light greatly enhanced molecular association, resulting in the formation of either large clusters or long ribbon-like superstructures. The PS-g-P2VP copolymers were found to efficiently solubilize and release hydrophobic small molecules in aqueous media. The partition coefficient and solubilization capacity of the copolymers for hydrophobic polyaromatic hydrocarbons increased with the polystyrene content of the copolymers, while the rate of solubilization decreased with increasing branching functionality of the copolymers. The release profiles for two model drugs displayed an initial burst in release followed by gradual approach to equilibrium. The diffusion coefficients of the drugs in the micelles increased with the branching functionality and the generation number of the micelles, presumably due to increased electrostatic repulsions of the protonated vinylpyridine units. ii

Challenges faced by telemedicine in Africa : case study from Cameroon

Telemedicine implementation in Africa is increasingly becoming am important topic of discussion; in and out of Africa, investigated, and implemented, yet the term lacks conceptual clarity and definition to health workers within the African continent itself. The primary purpose was to examine perceived susceptibility, some common barriers, and self-efficacy associated with the implementation put in place. Furthermore, the components, process, and outcomes of telemedicine as it is delivered in the African health structure have not been clearly expressed. This report provides an exemplary analysis concept, through available literature; even though very insufficient. During the study, a qualitative finding method was employed. Whereby the interpretative research method has been the key method to interpret all phenomena, it provides a useful tool with which to analyze existing literature on the development, scope and the extent to which telemedicine is used within Africa and other low income countries. From the finding, it was basically identified that the high cost of telemedicine infrastructure tools is so far the greatest challenge African have in the effort put in place to sustain the implementation of telemedicine. This is compared to the economic situation of the nation. Other related factors are technical and organisational challenges, infrastructural difficulties, cost distribution and cost recovery policies put in place, the direct benefit of telemedicine, African health policies and educational challenges. Despite the successes as well as failures within the African nations, telemedicine programs are still working to achieve the results needed to propel this new approach of health care forward, telemedicine today is outstandingly from many other studies very promising due to the great value that can be brought by its implementation

Integration and hegemonic relationship of labour market inequality : an investigation of immigrants/policy officials perceptions on immigrant's labour inclusion in Jyvaskyla-Finland

The aim of the research was to investigate the perceptions of immigrants (students, refugees and others) and public officials, on the value of Finnish economic integration within the broader context of immigrant-host labour relationship. Employing Gramsci theory of Hegemony, this study examined those discursive hegemonies in defining the economic and labour market importance of migration and integration, and how does such "hegemonic definitions" resonate within the views of Non-EU foreign students and other migrants. How does hegemonic labour inequality explicate when certain notions of belonging and identity resonates within labour market inclusions of Immigrants. To understand how perceptions were made, two conceptual variables (Finnish Language and Immigrant Ethnicity) were identified as instruments which influence perceptions towards labour market equality. Datas were collected through administered semi-structured interviews with immigrants and Finns at policy level of administration in Jyvaskyla. Employing rhetorical analysis on research data, result finding shows that perceptions of labour inequality were created differs within immigrant statues. It was difficult to problematized integration policies and framework as a phenomenon resulting to hegemonic labour inequality between Finns and immigrants groups in Jyvaskyla-Finland. However, this study was able to ascertained that, the Finnish integration policies/framework make available certain privileges towards certain immigrant groups (refugees and family-reunion migrants) with exceptions of student immigrants; unconsciously laying a framework under which immigrant groups are unequally integrated into the Jyvaskyla-Finnish labour market. Nevertheless, on the broader scope of multicultural hegemonic encounters, this study was able to problematize that, the desire to maintain their cultural hegemony, certain dominant values (Finnish language and Finnishness in whiteness) were power phenomenon which were unconsciously and consciously employed by the dominant group (labour market institutions) to influence immigrant labour market inclusion. A situation we further conceptualised as hegemonic relationship of labour market inequalities. The implications of the research findings were discussed

To Examine Blood and Lymphatic Microvasculature Densities in Endometrial Polyps, Adjacent and Distant Endometrium

Endometrial polyps (EPs) are overgrowths of endometrial glands that are protruding into the uterine cavity. EPs are benign in nature and affect both reproductive age and postmenopausal women. The aims were to quantify the blood and lymphatic microvasculature of EPs, adjacent and distant endometria. Assess the variation of these vasculatures across the menstrual cycle. Determine if these vasculatures are related to common symptoms of EPs. It was hypothesised that Microvasculature densities of EPs would be higher compared to normal endometrium, with no variation of these vessel densities across the menstrual cycle and that it would differ in women with and without symptoms. Archived samples were collected from 20 women with confirmed endometrial polyps and 32 women without endometrial polyps during the stages of the menstrual cycle. Immunohistochemistry was performed with CD31 (blood vessels) and D2-40 (lymphatic vessels). There were no significant differences in blood vessels between endometrial polyps and adjacent, distant and control endometria (F (3,70) = 2.36, p = 0.079) and like wise in lymphatic vessel density (F (3,70) = 0.16, p = 0.920). Although there was a numerical difference in the mean blood vessel density, there were no significant differences observed in blood vessels between endometrial polyps and normal endometrium