In this study, lanolin alcohol as well as lanolin alcohol-povidone films (1:1 . 5) were investigated as a potential drug delivery system. The in vitro drug release from these films was studied in terms of the effect of agitation, film thickness and drug concentration. The rate of release of Cortisol from lanolin alcohol films was not affected by the intensity of agitation. Moreover, the film matrix was found to remain essentially intact throughout the release process. Further analysis of the data revealed that Higuchi's diffusion-controlled granular matrix model explained the mechanism of Cortisol release from such films. The results of drug release from lanolin alcohol povidone films have shown that although Higuchi's release rate constant was found to be independent of film thickness, it was affected by the intensity of agitation, since the rate constant was found to increase as agitation speed was increased, especially at low speeds. In addition, povidone was found to leach out of the film matrix along with the drug. These factors, in conjunction with further analysis of the drug, explained the failure of this film system to conform to the matrix-controlled diffusion model. The release rate of Cortisol from this film system was found to follow first-order dependence on drug concentration. The drug was found to be completely insoluble in lanolin alcohol, and slightly soluble in povidone. Povidone was found to enhance the solubility of Cortisol in water.

The supposed thesis considers problem of heating of composite material for outdoor application. Basement of thesis is analysis of submitted sample of composite material. Measured values of composite material were compared and evaluated and than acceptable samples were choosen for next application. Part of thesis is creation of measuring software for analysis of sample. Other part of thesis is realization of equipment of control unit for heating of composite material. Control unit makes it possible to regulate heating and to set up parameters from computer.

Goal of this doctoral thesis is to focus to understand of behavior of working of basic electronics circuits and to appoint which parameters of these circuits is possible to control using external digital system. Further the examples of some digitally controlled analog circuits are present and the analysis of these circuits is achieved. Some of these blocks are realized and the results of that’s measuring is presented.

L'énergie nucléaire est l’un des moteurs de notre société moderne et, malgré des controverses, est considérée comme la forme d'énergie la plus efficace et la plus écologique. Néanmoins, elle est également à l'origine de nombreuses craintes : de part les déchets fortement radiotoxiques produits par les réacteurs et aussi les risques éventuels d’accidents nucléaires qui posent, sur la santé publique et l'environnement, de graves problèmes. Dans ce contexte, l'objectif de ce projet était de proposer de nouveaux matériaux innovants, capables de piéger efficacement les radionucléides dans les milieux aqueux contaminés. Un nouveau polymère est décrit et a été synthétisé à la fois en solution en utilisant la polymérisation radicalaire contrôlée de type Cu0-CRP mais également à partir de différents substrats comme le PET et le PVC, ce dernier s’étant révélé le plus efficace. Ces nouveaux matériaux ont ensuite été testés et se sont avérés très performants dans le piégeage de l'uranium et de nombreux lanthanides dans l'eau. Ces résultats ont de nombreuses applications potentielles dans l'industrie nucléaire. Ils peuvent être utilisés pour récupérer l'uranium de l'eau de mer comme une future source d'énergie renouvelable. Ils peuvent également contribuer à l'industrie de la gestion des déchets nucléaires, en permettant d’extraire les actinides et/ou lanthanides des effluents radioactifs. En plus, ces matériaux sont prometteurs dans le domaine du traitement des eaux radio-contaminées et la radiodétoxification des organismes vivants, y compris les humains. / Nuclear energy is the true engine of our modern day society and seen as the most efficient and clean form of energy. At the same time, it is the source of many concerns, with its highly radiotoxic waste produced by nuclear reactors and the public health and environmental risks that follow nuclear accidents. In this context, the aim of this project was to come up with new innovative materials, capable of efficiently trap radionuclides in contaminated aqueous media. A new polymer is reported and synthesized in solution as a free polymer, using the easy, cheap and fast metallic copper-mediated controlled radical polymerization (Cu0-CRP). The new polymer was also built from different substrates like PET and PVC, the latter being the most efficient. These new materials were later put to test and proved to be highly performing in trapping uranium and many lanthanides in water. These results have many implications in the nuclear industry. They can be used to harvest uranium from seawater as a future renewable energy source. They can also help the nuclear waste management industry. They are also a potential candidate for treating radio-contaminated environments and for radiodetoxification of living species, including humans.

Orientador: Luiz Francisco Malmonge / Resumo: Os fertilizantes de liberação modificada têm conquistado âmbitos cada vez maiores nas pesquisas e em utilizações agrícolas devido a suas principais características de menores perdas de nutrientes e por seu menor custo, que envolve menos aplicações no campo e menores quantidades de fertilizantes utilizados, comparado aos fertilizantes convencionais. Este trabalho teve como objetivo elaborar fertilizantes com possível comportamento de liberação modificada, através da incorporação do fosfato de potássio monobásico (KH2PO4) no polímero quitosana, contribuindo, dessa forma, com as três fontes de nutrientes primários essenciais requeridos pelas plantas: nitrogênio, fósforo e potássio, por apenas dois recursos. Foram elaboradas duas amostras diferentes para posterior comparação, análise e aplicação. Os métodos utilizados no preparo das amostras foram: gotejamento em solução básica coagulante e casting. Foram feitas soluções de 8% de quitosana (m/v) dissolvidas em soluções de 5% de ácido acético, e subsequentemente foi adicionado o KH2PO4 (em diferentes concentrações para análise e para aplicação agrícola, foi usada a concentração de 60% (m/m) em relação à massa de quitosana). Foram feitas Microscopia eletrônica de varredura (MEV) para análise morfológica das amostras, Energia dispersiva de raios-X (EDX) para constatação dos elementos contidos nas amostras, o estudo da liberação dos nutrientes em solução aquosa (em pHs 5,4 e 6,7) e por fim, as amostras foram aplicadas em mudas de alf... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Modified-release fertilizers have been increasingly used in research and in agricultural uses due to their main characteristics of lower nutrient losses and their lower cost, which involves fewer applications in the field and less quantities of utilized fertilizers, compared to the conventional ones. This work aimed to elaborate fertilizers with possible modified release behavior, through the incorporation of monobasic potassium phosphate (KH2PO4) in the chitosan polymer, thus contributing with the three sources of essential primary nutrients required by plants: nitrogen, phosphorus and potassium, from only two resources. Two different samples were prepared for later comparison, analysis and application. The methods used in preparing the samples were: dripping in a basic coagulant solution and casting. Solutions of 8% chitosan (w/v) were prepared dissolved in solutions of 5% acetic acid, and subsequently KH2PO4 was added (in different concentrations for analysis and for agricultural application, the concentration of 60% (w/w) in relation to the chitosan mass). Scanning electron microscopy (SEM) was performed for the morphological analysis of the samples, energy dispersive X ray (EDX) to verify the elements contained in the samples, the study of the release of nutrients in aqueous solution (at pH 5.4 and 6, 7) and finally, the samples were applied to lettuce seedlings for comparative effect and material efficiency. The results of the EDX spectra showed that in the samples made... (Complete abstract click electronic access below) / Mestre

The development of pyrethroid resistance in mosquitoes threatens the goal of malaria elimination in Africa. Alternative insecticides, e.g. organophosphates, can be considered to control pyrethroid resistant mosquitoes. The problem associated with the deployment of organophosphate-based insecticides is their high volatility. Conventional application forms have a fairly short residual efficacy. This study aimed at extending the residual efficacy of an organophosphate insecticide by using a polymer matrix as a slow release device. A multilayer film blower was used to produce a trilayer film. The middle layer comprised poly(ethylene-co-vinyl acetate), i.e. EVA polymer, impregnated with malathion. This was sandwiched by two low density polyethylene (LDPE) outer layers. These acted as semi-permeable membrane-like barriers that slowed down the release of the contact insecticide to the surfaces of the film. In theory, such a film could be deployed as a long-lasting insecticide-treated wall lining in pyrethroid resistant settings. Scanning electron microscopy (SEM) confirmed the trilayer film structure of the blown film. The malathion release from the film was tracked with Fourier transform infrared spectroscopy (FTIR). The malathion absorption band in the FTIR spectra disappeared gradually over time. Confocal Raman analysis showed a malathion concentration gradient across the thickness of the polyethylene layers. These results suggested diffusion-controlled transport through the LDPE membranes. Bioassays indicated that the residual efficacy of the malathion, against mosquitoes, was increased to about six months. This means that trilayer films, impregnated with an organophosphate, may have potential as alternative mosquito control interventions in pyrethroid resistant settings. / Dissertation (MEng)--University of Pretoria, 2017. / Chemical Engineering / MEng / Unrestricted

Extramedicínské (zne)užívání buprenorfinu v Gruzii a efektivní léčebná intervence MUDr. David Otiashvili Abstrakt Background Since early 2000s, the nonmedical abuse of buprenorphine (Subutex®) tablets, presumably smuggled from EU countries, has represented major phenomena of the problem drug scene in the Republic of Georgia. In a country with relatively high level of injecting drug use (estimated 40,000 persons, i.e. 1.5 % of population aged 15-64, of whom over 50% inject buprenorphine), this represent a major public health problem that needs detailed description and comprehensive set of interventions. Aim (i) To describe the extent of nonmedical buprenorphine ab/use in the Republic of Georgia, the characteristics of the nonmedical ab/users and their motivations for seeking and using the black market buprenorphine. Subsequently, (ii) to plan and pilot-test a treatment intervention that would be more specific and effective than the simple detoxification and/or harm reduction modalities available in Georgian on a routine basis. Setting Four regional centres of Georgia were included into the descriptive part of the study: the cities of Tbilisi, Gori, Zugdidi, and Batumi. The intervention (sub)study was conducted in one Tbilisi addiction treatment clinic. Participants and methods For the descriptive part of the...

Controlled foreign company (CFC) rules are anti-avoidance provisions designed to deter taxpayers from shifting their capital (and resultant income) to low-tax jurisdictions. Adoption of these rules in South Africa coincided with the relaxation of exchange control laws which opened up borders to inward and outward capital flows. South Africa's CFC regime has been amended over the years to become one of the most sophisticated amongst the G20 and aligned with the Organisation for Economic Co-operation and Development's (OECD) Action 3 recommendations (per the OECD's Base Erosion and Profit Shifting Action Project). Abusive profit-shifting tactics committed by multinational enterprises (MNEs) have caused the OECD to recommend that CFC rules be strengthened globally to combat this behaviour. However, in the United States and the United Kingdom, recent reforms appear to have weakened these countries' CFC (or CFC-equivalent) legislation, countering the OECD's recommendations. Such manoeuvres improve the profitability of these nations' MNEs by allowing their tax bills to remain lower than their international competitors'. As such, there is a danger of starting a race to the corporate tax-rate bottom where developing nations will be the losers, considering their greater reliance on corporate tax revenues than their developed counterparts. India and Brazil, both developing nations and BRICS members like South Africa, also aren't prioritising the strengthening of their CFC regulations – their focus is rather on improving transfer pricing (TP) legislation and enforcement to combat the damaging effects MNEs' avoidance practices are having on tax revenue collections in those countries. The existence of South Africa's advanced CFC legislation amongst a global trend of a weakening in, or the non-adoption of, CFC rules may hinder the competitiveness of South African MNEs. The current CFC regime could thus serve the purpose of stifling growth and foreign direct investment, instead of only deterring profitshifting behaviour. TP legislation targeted at MNEs (the biggest profit-shifting culprits) may yield the most effective anti-avoidance results. South Africa's recently enhanced TP reporting requirements are key to solving the offshore profit-shifting puzzle, as these reports will reveal information about an MNE's global operations and resultant profit-shifting activities. In addition, the revision to the TP arm's length principle to align compensation and value creation, will see profit-shifting MNEs bear the tax they were trying to avoid. It appears that the anti-avoidance purpose embodied within CFC regulations overlaps with the anti-avoidance mechanisms that these enhanced TP rules are designed to achieve. Thus, in a South African context, the most efficient way to curb tax avoidance may be to rely on TP, rather than CFC, legislation. As such, it is recommended that South Africa's CFC regulations be repealed.

The controlled release of therapeutics has been one of the major challenges for scientists and engineers during the past three decades. To address this outstanding problem, the design and fabrication of stimuli-responsive materials are pursued to guarantee the controlled release of cargo at a specific time and with an accurate amount. Upon applying different stimuli such as light, magnetic field, heat, pH change, enzymes or redox, functional materials change their physicochemical properties through physical transformation or chemical reactions, allowing the release of payload agents on demand. This dissertation studied three stimuli-responsive membrane systems for controlled release from films of macro sizes to microcapsules of nano sizes. The first membrane system is a polymeric composite film which can decrease and sustain diffusion upon light irradiation. The photo-response of membranes is based on the photoreaction of cinnamic derivatives. The second one is composite membrane which can improve diffusion upon heating. The thermo-response of membranes comes from the volume phase transition ability of hydrogels. The third one is microcapsule which can release encapsulated agents upon light irradiation. The photo-response of capsules results from the photoreaction of nitrobenzyl derivatives. The study on these membrane systems reveals that stimuli-responsive release can be achieved by utilizing different functional materials on either macro or micro level. Based on the abundant family of smart materials, designing and fabricating stimuli-responsive systems shall lead to various advanced release processes on demand for biomedical applications.

Background: There is an established need to manage teasing and bullying of children who stutter (CWS) through changing the attitudes of their peers. The intervention, the Classroom Communication Resource (CCR), was implemented by teachers in classrooms. The primary objective of the main study was to determine the effectiveness of the CCR through a cluster Randomised Controlled Trial (RCT). The secondary objective of this study was to determine the treatment effect of the Stuttering Resource Outcomes Measure (SROM) within the subscales of Positive Social Distance (PSD), Social Pressure (SP) and Verbal Interaction (VI). The subgroup objective was to determine the primary objective between and across lower and higher school quintile clusters. Method: A cluster RCT was conducted. Participants in grade 7, aged 11 years and older, were randomly assigned to control and intervention groups using school and subgroup (quintile) clusters classifications. Following randomisation, stratification took place using a 1:1 allocation ratio. Participants viewed a video of a child who stuttered at baseline. Teachers administered the CCR (social story, role-play, discussion) in intervention groups only over a 60-90 minute session after they received an hour of training. Peer attitudes were measured at baseline and at 6 months post-intervention using the SROM in intervention and control groups. Results: A total of 10 schools were included whereby they were randomly allocated to control (k=5) and intervention groups (k=5). Within the schools, 454 participants were included with n =223 participants in the intervention and n= 231 in the control group. The study showed no statistically significant difference on the global SROM score (mean difference: -0.11 [95% confidence interval: -1.56, 1.34]; p = 0.88). Similarly, no significant differences were noted on SROM subscales: PSD (1.04 [-1.02,311]; p =0.32), SP (-0.45 [-1.22, 0.26]; p=0.21) and VI (0.05 [-1.01, 1.11]; 0.93), the secondary objective of this study. No significant subgroup effect on the global SROM score (lower vs higher quintile subgroups) [interaction p-value = 0.52] was observed during subgroup analysis. Results were however consistent with the hypothesis and quintile subgroups behaved similarly. Results were found clinically important when considering confidence intervals as well as the magnitude and direction of treatment effect. Conclusion: While the treatment effect showed no statistically significant differences on the global SROM and within the constructs of PSD, SP and VI, a clinically important result was noted when evaluating the meaningfulness of this study as well as its implications. Subgroup analysis showed that the quintiles behaved similarly, showing that the CCR was appropriate for schools within the lower and higher quintiles.