Improved polymeric medical devices for active substances delivery

The work presented in this thesis was developed in collaboration with a Portuguese company, BeyonDevices, devoted to pharmaceutical packaging, medical technology and device industry. Specifically, the composition impact and surface modification of two polymeric medical devices from the company were studied: inhalers and vaginal applicators. The polyethylene-based vaginal applicator was modified using supercritical fluid technology to acquire self-cleaning properties and prevent the transport of bacteria and yeasts to vaginal flora. For that, in-situ polymerization of 2-substituted oxazolines was performed within the polyethylene matrix using supercritical carbon dioxide. The cationic ring-opening polymerization process was followed by end-capping with N,N-dimethyldodecylamine. Furthermore, for the same propose, the polyethylene matrix was impregnated with lavender oil in supercritical medium. The obtained materials were characterized physical and morphologically and the antimicrobial activity against bacteria and yeasts was accessed. Materials modified using 2-substituted oxazolines showed an effective killing ability for all the tested microorganisms, while the materials modified with lavender oil did not show antimicrobial activity. Only materials modified with oligo(2-ethyl-2-oxazoline) maintain the activity during the long term stability. Furthermore, the cytotoxicity of the materials was tested, confirming their biocompatibilty. Regarding the inhaler, its surface was modified in order to improve powder flowability and consequently, to reduce powder retention in the inhaler´s nozzle. New dry powder inhalers (DPIs), with different needle’s diameters, were evaluated in terms of internal resistance and uniformity of the emitted dose. It was observed that they present a mean resistance of 0.06 cmH2O0.5/(L/min) and the maximum emitted dose obtained was 68.9% for the inhaler with higher needle´s diameter (2 mm). Thus, this inhaler was used as a test and modified by the coating with a commonly-used force control agent, magnesium stearate, dried with supercritical carbon dioxide (scCO2) and the uniformity of delivered dose tests were repeated. The modified inhaler showed an increase in emitted dose from 68.9% to 71.3% for lactose and from 30.0% to 33.7% for Foradil.

A built-in self-test technique for high speed analog-to-digital converters

Fundação para a Ciência e a Tecnologia (FCT) - PhD grant (SFRH/BD/62568/2009)

Insurance segmentation as unfair discrimination: what to expect next in the wake of Test-Achats

Proceedings of the 16th Annual Conference organized by the Insurance Law Association of Serbia and German Foundation for International Legal Co-Operation (IRZ), entitled "Insurance law, governance and transparency: basics of the legal certainty" Palic Serbia, 17-19 April 2015.

Indicadores de prognóstico em utentes com disfunção do ombro submetidos a uma intervenção terapêutica direcionada para a estabilidade dinâmica da escápulo-torácica

RESUMO: Introdução/ Objetivo: Segundo a revisão sistemática de Chester e colaboradores (2013b)apenas dois fatores de prognóstico demonstraram uma associação consistente com o resultado que foram a duração dos sintomas e a funcionalidade na avaliação inicial. O objetivo do estudo é identificar indicadores de bom e mau prognóstico em utentes com disfunção do complexo articular do ombro (DCAO), tendo por base, aspetos da avaliação inicial do utente e critérios de alta de abolição da dor, aumento da funcionalidade e da estabilidade dinâmica considerando uma intervenção terapêutica direcionada para o aumento da estabilidade dinâmica da escápulo-torácica. Metodologia: Efetuou-se um estudo de coorte clínico retrospetivo. Para tal, aplicou-se um protocolo de intervenção terapêutica e analisou-se os resultados. A amostra foi constituída por 82 indivíduos com DCAO [53 com síndrome do conflito subacromial (SCSA) e 29 com instabilidade da glenoumeral (IGU)], residentes nos distritos de Lisboa, Setúbal e Santarém com o intuito de iniciar tratamento de fisioterapia. A análise dos dados foi efetuada tendo em consideração dois procedimentos: análise univariada (através do método de Kaplan-Meier para cada CVP) e análise multifatorial (pela análise de regressão de Cox e regressão logística nos grupos de utentes com SCSA, IGU e DCAO). Resultados: O tempo mediano de continuação no tratamento em fisioterapia foi de 7 semanas para os utentes com SCSA e 6 semanas para utentes com IGU. Segundo o teste de Logrank, na análise univariada, existem sete e oito covariáveis preditoras (CVP) com associação estatisticamente significativa (p<0,05) para o subgrupo SCSA e IGU, respectivamente. De acordo com estes resultados, a primeira parte da DASH e a SPADI são as únicas CVP com associação comuns às duas disfunções. Pela análise multifatorial e, em congruência com o teste de Wald, nenhuma das CVP contribui estatisticamente para o modelo preditivo de continuidade do tratamento de fisioterapia em qualquer um dos três modelos estudados: subgrupo SCSA, subgrupo IGU e utentes com DCAO. Conclusão: Por uma análise univariada verificou-se que existem CVP associadas à alta dos tratamentos em fisioterapia e estas não são as mesmas em ambas as DCAO. Contudo, a magnitude do efeito de cada CVP nos modelos multifatoriais definidos para os grupos de utentes com SCSA, IGU e DCAO não demonstraram valor estatisticamente significativo pelo que não foi possível determinar modelos de prognóstico em utentes com DCAO.-------------ABSTRACT: Background/ Purpose: According with the systematic review from Chester and collaborators (2013b) just two prognostic factors demonstrated a consistent association with the outcome: the duration of symptoms and functionality in the initial assessment. The purpose of the study is to identify indicators of good and poor prognosis in patients with shoulder’s dysfunctions, based on aspects of the initial assessment and discharge criteria of absence of pain, increased functionality and dynamic stability considering a therapeutic intervention used to increase the dynamic stability of scapulo-thoracic. Methodology: It was conducted a retrospective study of clinical cohort. For this purpose it was applied a protocol with therapeutic intervention and the results were analyzed. The sample consisted of 82 individuals with shoulder’s dysfunction (53 with subacromial impingement (SIMP) and 29 with shoulder instability (SINS) residing in the districts of Lisbon, Setúbal and Santarém in order to start physiotherapy. Data analysis was performed taking into account two procedures: univariate analysis [using the Kaplan-Meier method for each co-variant predictor variable (CVP)] and multifactorial analysis [analysis by Cox regression and logistic regression on groups of patients with SIMP, SINS and shoulder’s dysfunction (SD)]. Results: The median time of follow-up treatment at physical therapy was 7 weeks for patients with SIMP and 6 weeks for patients with SINS. According to the Logrank test in the univariate analysis, there are seven and eight CVP with a statistically significant association (p<0.05) for the patients with SIMP and SINS, respectively. According to these results, the first part of the DASH and SPADI are the only CVP common to both disorders association. By multifatorial analyses, and in agreement with the Wald test, none of the CVP contributes statistically to the predictive model of continuity of physiotherapy treatment in any of the three studied models: patients with SIMP, patients with SINS and patients with SD. Conclusion: In an univariate analysis, it was verified that there are CVP associated with discharge from treatments of physical therapy and these are not the same in both SD. However, the magnitude of effect of each CVP in multifactorial models for defined patients groups with SIMP, SINS and SD showed no statistically significant. Therefore, it was not possible to determine prognostic models for patients with SD.

Effects of quantitative easing on the USA economy: A test for policy effectiveness

The catastrophic disruption in the USA financial system in the wake of the financial crisis prompted the Federal Reserve to launch a Quantitative Easing (QE) programme in late 2008. In line with Pesaran and Smith (2014), I use a policy effectiveness test to assess whether this massive asset purchase programme was effective in stimulating the economic activity in the USA. Specifically, I employ an Autoregressive Distributed Lag Model (ARDL), in order to obtain a counterfactual for the USA real GDP growth rate. Using data from 1983Q1 to 2009Q4, the results show that the beneficial effects of QE appear to be weak and rather short-lived. The null hypothesis of policy ineffectiveness is not rejected, which suggests that QE did not have a meaningful impact on output growth.

Continuidade e mudança. O sistema internacional no post‐Guerra Fria

O fim da Guerra Fria é um caso inédito de mudança pacífica da estrutura internacional, em que os Estados Unidos e a União Soviética transcendem a divisão bipolar para decidir os termos da paz no quadro das instituições que definem o modelo de ordenamento multilateral, consolidando a sua legitimidade. Nesse contexto, ao contrário dos casos precedentes de reconstrução internacional no fim de uma guerra hegemónica, o novo sistema do post-Guerra Fria, caracterizado pela unipolaridade, pela regionalização e pela homogeneização, forma-se num quadro de continuidade institucional. A ordem política do post-Guerra Fria é um sistema misto em que as tensões entre a hierarquia unipolar e a anarquia multipolar, a integração global e a fragmentação regional e a homogeneidade e a heterogeneidade política, ideológica e cultural condicionam as estratégias das potências. As crises internacionais vão pôr à prova a estabilidade da nova ordem e a sua capacidade para garantir mudanças pacíficas. A primeira década do post-Guerra Fria mostra a preponderância dos Estados Unidos e a sua confiança crescente, patente nas Guerras do Golfo Pérsico e dos Balcãs, bem como na crise dos Estreitos da Formosa. A reacção aos atentados do "11 de Setembro" revela uma tentação imperial da potência unipolar, nomeadamente com a invasão do Iraque, que provoca uma crise profunda da comunidade de segurança ocidental. A vulnerabilidade do centro da ordem internacional é confirmada pela crise constitucional europeia e pela crise financeira global. Essas crises não alteram a estrutura de poder mas aceleram a erosão da ordem multilateral e criam um novo quadro de possibilidades para a evolução internacional, que inclui uma escalada dos conflitos num quadro de multipolaridade regional, uma nova polarização entre as potências democráticas conservadoras e uma coligação revisionista autoritária, bem como a restauração de um concerto entre as principais potências internacionais.

A practical approach to execute and test a lean startup

This paper practically applies the “Lean Startup Approach” by identifying, analyzing and executing a newly developed web-based business idea. Hypotheses were designed and tested with the construction of a minimum viable product – i.e. a landing page. In-depth interviews allowed deciding either to pivot or persevere the initial launch strategy. Overall, the aim was to collect as much valuable response as possible from customers and ultimately decide for a superior strategy while devoting the smallest amount of time and money.