Complexation of DNA with Cationic Surfactant

Transfection of an anionic polynucleotide through a negatively charged membrane is an important problem in genetic engineering. The direct association of cationic surfactant to DNA decreases the effective negative charge of the nucleic acid, allowing the DNA-surfactant complex to approach a negatively charged membrane. The paper develops a theory for solutions composed of polyelectrolyte, salt, and ionic surfactant. The theoretical predictions are compared with the experimental measurements.Comment: 9 pages, 3 figure

Processing and characterization of monoclinic-zirconia fibre-matrix interfaces in dense matrix alumina-alumina composites: Processamento e caracterização de interfaces fibra-matriz de zircônia não estabilizada em compósitos alumina-alumina de matriz densa

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Mecânica, Florianópolis, 2013.Interfaces fibra-matriz tem um papel muito importante no desempenho de compósitos de matriz cerâmica. Sendo a interação entre fibra e matriz for muito forte, o compósito se comportará como uma cerâmica monolítica, e sendo muito fraca, o compósito perderá sua integridade estrutural e suas propriedades interlaminares. Zircônia monoclínica (não-estabilizada) tem mostrado ser uma boa alternativa na produção de interfaces fibra-matriz para compósitos cerâmicos à base de alumina devido à sua baixa interação química durante a sinterização e também devido ao fenômeno de microtrincamento causado pela transformação tetragonal-monoclínica durante o resfriamento. Interfaces porosas à base de zircônia monoclínica, as quais apresentam baixa tenacidade devido à sua porosidade e microtrincamento, haviam sido usadas no passado para criar interfaces com baixa interação entre fibras de safira e matrizes de alumina. Neste sistema, as interfaces se mostraram quimicamente estáveis mesmo acima de 1300 °C. Compósitos tenazes à base de alumina haviam sido fabricados com zircônia monoclínica como interface. Entretanto, a porosidade da matriz era ? 13%, o que dificulta a interpretação dos resultados, pois as propriedades mecânicas do compósito não podem ser claramente atribuídas às propriedades da zircônia monoclínica. Neste trabalho, compósitos-modelo com matriz densa e fibras individuais de alumina foram produzidos. A interface fibra-matriz foi produzida através de recobrimento por dip-coating das fibras em suspensões cerâmicas de zircônia monoclínica. Diferentes tamanhos de partícula foram utilizados no processo de dip-coating com o objetivo de variar a porosidade e assim, as propriedades das interfaces. A tensão de cisalhamento interfacial foi determinada através do teste de pushin nas fibras. O fenômeno de deflexão de trincas foi avaliado através de trincas criadas por indentação Vickers e o fenômeno de pullout das fibras através de observações nas superfícies de fratura. Propriedades como tenacidade à fratura, dureza e módulo de elasticidade da matriz e interface foram avaliadas para determinar os parâmetros de deflexão de trincas propostos por He e Hutchinson.Abstract : Fibre-matrix interface properties play an important role on the performance of ceramic matrix composites. Being the fibre-matrix interaction too strong, the composite will behave such as a monolithic ceramic and being too weak, the composite will lose its structural integrity and its interlaminar properties. Monoclinic (unstabilized) zirconia has shown to be a suitable alternative for the production of fibre-matrix interfaces for alumina ceramic matrix composites due to its low chemical interaction during sintering and due to the microcracking phenomenon caused by the tetragonal-monoclinic transformation during cooling. Porous oxide coatings of monoclinic zirconia, which have low toughness because of their porosity and microcracking, have been used in the past to achieve debonding between sapphire fibres and alumina matrices and were to be chemically stable with sapphire above 1300 °C. Tough alumina matrix composites have been fabricated using monoclinic zirconia as fibres coating. However the matrix porosity was = 13%, which makes it difficult to interpret the results, because the toughness cannot be unambiguously attributed to the properties of the unstabilized zirconia interfaces. In this work, model composites with dense alumina matrix and single alumina fibres were fabricated. The fibre-matrix interface was produced via dip-coating single fibres in monoclinic zirconia suspensions. Different particle sizes were used for the dip-coating in order to vary the coating porosity. The interfacial sliding stress was determined via a modified fibre pushin test. The crack deflection behaviour was analysed from cracks created via Vickers indentations and the fibre pullout via surface fracture observations. Properties such as fracture toughness, hardness and elastic modulus for the interface and matrix were also evaluated in order to determine the crack deflection parameters established by He and Hutchinson

Framework conditions of academic entrepreneurship: An empirical investigation at Swiss Universities of Applied Sciences

Operating at the interface between scientific research and commercial exploitation of research, knowledge transfer in the form of academic entrepreneurship is considered integral to the so- called third mission of universities and universities of applied sciences. Spin-off engagement has been studied by both psychological and economistic scholars using institutional and motivational theories, yet there is still limited knowledge about how organizational conditions interact with scientist’s motivation and drive academic entrepreneurship. This research is urgently needed, as it is known from the literature that a lack of organizational support that addresses scientists' needs can lead to institutional barriers and a lack of academic spin-off engagement. Motivated by recent data demonstrating female entrepreneurial activity among academics in scientific fields lags behind that of men, the first manuscript presents an analysis of formal and informal entrepreneurial conditions at Swiss universities of applied sciences to identify the status of female entrepreneurship. By addressing the aforementioned gap, the descriptive approach of the first manuscript explored the lack of support for female scientists involved in entrepreneurship and shed light on how to promote their full entrepreneurial potential. Research has shown that while a positive environment promotes entrepreneurship, personal motives and satisfaction with the current work situation may also determine entrepreneurial careers. The second manuscript is concerned with job satisfaction as a moderator in entrepreneurial decision-making. Individuals make critical choices between employment and self-employment to maximize the benefits of career choice when considering expected outcomes. Prior research identified entrepreneurial careers as an escape from poor work environments; thus, there is a lack of understanding regarding how job-satisfaction triggers entrepreneurship within universities. Informed by Social Cognitive Careers Theory, a multigroup analysis aims to test if job dissatisfaction fosters the re-evaluation of outcome expectations to define entrepreneurial career goals. The third manuscript examined the robustness of intentional motivation theories in prior entrepreneurship research. By combining the Theory of Planned Behavior and Mindset Theory of Action, this investigation addresses the formation of entrepreneurial intention, focusing on the transition from motivation to implementation in the context of academia. Until recently, research mostly relied on cross-sectional data to predict and measure the strength of entrepreneurial intention in the phase preceding the launch of a new business, without 8 considering whether participants were in the motivational or actional phase. In turn, this creates a gap of knowledge concerning the cognitive and motivational processes involved in fostering entrepreneurial intention. The research questions above were addressed using a survey of academics from the Swiss universities of applied sciences. Overall, the thesis contributes new findings to the current literature in three primary ways. First, it highlights the lack of a stimulating entrepreneurial environment at Swiss UAS, thus serving as a basis for decision makers to start future incentives to foster female entrepreneurship. Second, it shows that academics are more likely to engage in entrepreneurial activities than spin-off activities when they have positive outcome expectations toward entrepreneurial actions and are dissatisfied with their current employment. Third, by showing a direct influence of entrepreneurial engagement on intention, a moderation effect of engagement on the Theory of planned behavior predictors and a threshold of intention-growth per the context after the initiation of the first entrepreneurial action, this thesis reignites prior discussion about studying entrepreneurial intention rather than behavior. The findings of this thesis highlight the need to transform intention-based research into action-based research when studying the impact of organizations on the creation of academic spin-offs since much more research untangling the cognitive mechanisms behind the business implementation is required. For policymakers, the results of the thesis are in line with SNSF-project outcomes, calling for new strategies for targeted and personalized support for academics at universities of applied sciences

Novel Viral Vector Systems for Gene Therapy

Over the last three decades, interest in the field of gene therapy seems to have fluctuated between hot and cold. Encouraging pre-clinical and clinical data has demonstrated the potential of genetic therapies and yet setbacks in clinical trials have cast doubts in some minds over the clinical future of gene therapy [1-3]. In the last two years, a number of studies have demonstrated therapeutic benefits in clinical trials aimed towards specific monogenetic disorders [4-6], and this has brought renewed optimism to the field. [...

A crowd-sourcing approach for the construction of species-specific cell signaling networks

Motivation: Animal models are important tools in drug discovery and for understanding human biology in general. However, many drugs that initially show promising results in rodents fail in later stages of clinical trials. Understanding the commonalities and differences between human and rat cell signaling networks can lead to better experimental designs, improved allocation of resources and ultimately better drugs. Results: The sbv IMPROVER Species-Specific Network Inference challenge was designed to use the power of the crowds to build two species-specific cell signaling networks given phosphoproteomics, transcriptomics and cytokine data generated from NHBE and NRBE cells exposed to various stimuli. A common literature-inspired reference network with 220 nodes and 501 edges was also provided as prior knowledge from which challenge participants could add or remove edges but not nodes. Such a large network inference challenge not based on synthetic simulations but on real data presented unique difficulties in scoring and interpreting the results. Because any prior knowledge about the networks was already provided to the participants for reference, novel ways for scoring and aggregating the results were developed. Two human and rat consensus networks were obtained by combining all the inferred networks. Further analysis showed that major signaling pathways were conserved between the two species with only isolated components diverging, as in the case of ribosomal S6 kinase RPS6KA1. Overall, the consensus between inferred edges was relatively high with the exception of the downstream targets of transcription factors, which seemed more difficult to predict. Contact: [email protected] or [email protected]. Supplementary information: Supplementary data are available at Bioinformatics onlin

„Rhinologisches Outcome nach endoskopischer transnasal-transsphenoidaler Resektion pathologischer Prozesse im Bereich der sellären Region – prospektive Studie“

157 Seiten, Diagramm

12-jährige Versuchswirthschaft mit Gründüngung und künstlichen Düngemitteln ohne Anwendung von Stalldünger

http://www.ester.ee/record=b3786836*es

Transformación de la movilidad en las ciudades

La producción en serie del automóvil, junto a la industria del asfalto, ha cambiado la forma del mundo en menos de cien años. No sólo la forma física de las ciudades, sino la forma de moverse de los ciudadanos y, por tanto, nuestra forma de vivir y de pensar. El coche proporciona a nivel individual y familiar la libertad de movimiento en tiempo y espacio. No obstante, no podemos olvidarnos de la cantidad de inconvenientes que genera el uso del coche y por ello va perdiendo peso entre la sociedad. A lo largo de los últimos años, incluso se puede decir la última década, las ciudades han tenido que reinventarse y volver al pensamiento de que la ciudad no es para el coche sino para el peatón por la alta contaminación que hay en muchas de ellas. Actualmente, todos somos conscientes del problema de movilidad que presentan la mayoría de las ciudades de todo el planeta y aparecen nuevas formas de movilidad. Hoy en día por las calles te encuentras gente caminando, patinetes eléctricos, bicicletas, transporte público, vehículos privados, motocicletas y un largo etcétera de posibilidades para moverse. En este Trabajo Final de Grado empezaré exponiendo cómo actúan algunas ciudades para tener una movilidad más amigable con el medio ambiente y poder reducir las consecuencias negativas que presenta el gran uso del automóvil. Para ello, haré un análisis de qué medidas se han tomado en otras urbes y que actuaciones está tomando Barcelona con el fin de poder compararlas. También expondré las medidas que está tomando la ciudad catalana en esta pandemia de la COVID-19. El último apartado del trabajo, tratará de un resumen de las medidas que se pueden tomar en nuestra ciudad de Barcelona, aparte de las ya consideradas en apartados anteriores, y que consecuencias pueden conllevar la puesta en marcha de esas medidas