Efeito dos parâmetros de síntese na transição sol-gel e nas propriedades físicas de Ambigéis de Nióbia (Nb2O5)

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Ciência e Engenharia de Materiais, Florianópolis, 2016.O processo sol-gel, é um método bottom-up de síntese de nanomateriais que, mediante reações de hidrólise e condensação, envolve a obtenção de um sol e a sua posterior gelificação. Neste trabalho, foi estudado, por meio de um planejamento experimental, o efeito de parâmetros de síntese como razão molar de água (H2O:Nb+5), razão molar de catalisador (HNO3: Nb+5) e razão molar de óxido de propileno (OP:Nb+5) na transição sol-gel e nas propriedades reológicas de alcogéis e em propriedades físicas tais como: área superficial especifica, distribuição de tamanho de poro, cor, transmissão no espectro visível e energia de band gap de ambigéis de nióbia (Nb2O5). Duas diferentes rotas de síntese usando pentaetóxido de nióbio (Nb(OEt)5) (Rota A) e pentacloreto de nióbio (NbCl5) (Rota B) como precursores foram estudadas com o objetivo de comparar e validar uma nova rota de preparação. Mediante o ensaio de viscosidade em função do tempo, foi possível identificar um comportamento comum, independentemente da rota e das composições utilizadas, que pode ser divido em quatro regiões principais: uma primeira região de gelificação, uma segunda região de envelhecimento, uma terceira região de platô (viscosidade constante) e uma última região onde o gel começa a quebrar-se. Todos os géis produzidos apresentaram estrutura amorfa, comportamento pseudoplástico, tensão de escoamento e tixotropia. O tempo de gelificação diminuiu com o aumento da razão molar de H2O:Nb+5 e aumentou com a diminuição do pH (aumento da razão molar de H2O:HNO3). Os géis produzidos mediante a Rota B apresentaram maiores viscosidades do que os géis produzidos pela Rota A. A área superficial específica aumentou com o aumento da razão molar de H2O:Nb+5 para a Rota A e com a diminuição do pH para a Rota B. Os géis e ambigéis apresentaram cor branca e translucidez para a Rota A e Rota B respectivamente. A maior área superficial especifica obtida para a Rota A foi 106 m2/g e de 99 m2/g para a Rota B. A Rota A apresentou uma transmitância no espectro visível entre 50.8% e 64.7% e a Rota B entre 67.5% e 76%. Obtiveram-se valores de band gap de 5.3 eV e 2.9 eV para a Rota A e para a Rota B respectivamente. A Rota B (NbCl5) demonstrou ser uma rota adequada para preparar ambigéis com área superficial comparável aos produzidos mediante a Rota A (Nb(OEt)5).Abstract : Sol-gel process is a bottom-up method used to synthetize nanomaterials that, through hydrolysis and condensation reactions, involves the preparation of a sol and its gelification. In this work was investigated, using an experimental design, the influence of synthesis parameters like water molar ratio (H2O:Nb+5), catalyst molar ratio (HNO3: Nb+5) and propylene oxide molar ratio (OP:Nb+5) on sol-gel transition and rheological properties of Nb2O5 alcogels and physical properties like specific surface area, pore size distribution, color, transmittance in the visible spectrum and band gap energy of Nb2O5 ambigels. Two different synthesis routes using niobium pentaethoxide (Nb(OEt)5) (Route A) and niobium pentachloride (NbCl5) (Route B) as precursors were studied in order to compare and validate a new preparation route. In the viscosity in function of time curves, it was possible to identify a common behavior independently of the route and compositions used. This behavior can be divided in four main regions: a first region of gelification, a second region of plateu (constant viscosity) and a last region where the gel starts to break down. All gels had amorphous structure, pseudoplastic behavior, yield stress and thyxotropy. Gel time decreased with the increasing H2O:Nb+5 molar ratio and decreasing pH (increasing H2O:HNO3 molar ratio). Gels made with Route B presented higher viscosities than the ones made with Route A. Specific surface area increased with the increasing H2O:Nb+5 molar ratio for Route A and with the decreasing pH for Route B. Gels and ambigels made using Route A presented white color while gels and ambigels prepared with Route B presented translucity. The higher specific surface areas obtained were 106 m2/g for Route A and 99 m2/g for Route B. Transmittance in the visible spectrum varied between 50.8% and 64.7% for Route A and 67.5% and 76% for Route B. Band gaps of 5.3 eV and 2.9 eV were obtained for Route A and Route B respectively. Route B (NbCl5) demonstrated to be an adequate route for preparing ambigels with comparable specific surface area to ambigels produced by Route A (Nb(OEt)5)

Lung cancer in Spain: information from the Thoracic Tumors Registry (TTR study)

[Background] Lung cancer remains a leading cause of cancer incidence and mortality worldwide. Although Spain contributes to global statistics related to cancer, it is difficult to discern aspects linked to clinical presentation of the disease or molecular testing. The Thoracic Tumor Registry (TTR) was created with the aim of filling this gap.[Methods] Observational cohort multicenter study performed in Spain, including patients with lung cancer or other types of thoracic tumors undergoing active treatment or palliative care only. Enrollment took place between August 2016 and December 2018. The evaluation included a review of demographic, epidemiological, clinical and molecular data.[Results] A total of 6,600 patients diagnosed with non-small cell lung cancer (NSCLC) were recruited at 56 Spanish hospitals. The mean age at diagnosis was 64 years. The majority of patients (80%) presented with advanced disease, being adenocarcinoma the most frequent histological type. Up to 86% of patients were current- or ex-smokers, with men starting to smoke earlier than women (average age 17.9 vs. 19.2 years). Sixty-seven percent of patients underwent some type of molecular testing. Mutations in EGFR and KRAS genes were found in 18% and 28% of patients, respectively.[Conclusions] Our findings suggest that the TTR study accurately describes the clinical reality of lung cancer in Spain, including useful information on smoking status as well as molecular profiling and tumor histology, and can therefore be used to drive improvements in health care. Social and political pressure to reduce tobacco consumption among the population should be reinforced, particularly among youth.This work was supported by Grupo Español de Cáncer de Pulmón (GECP), Novartis, Lilly and Merck Sharp & Dohme (MSD)

Perovskite solar cells for building integrated photovoltaics

Building integrated photovoltaics (BIPV) have an advantage of generating electricity in the vicinity of energy use. Opportunities exist for thin film photovoltaics such as the rapidly evolving perovskite solar cells. However, long-term durability is essential, requiring research into application-specific requirements that may be affected by perovskite-specific instabilities (to e.g. temperature, oxygen and moisture). The first part of this thesis studies thermal implications of integrating perovskite solar cells in insulated and laminated glazing. To calculate total radiative heat transfer and hence temperature accurately, total hemispherical thermal emittance (ε_H) as a function of temperature is required as the reflectance and emittance of solar cells are strongly angle-dependent. In this thesis, a new method for measuring ε_H is developed by transient calorimetry performed in a cavity under vacuum based on the Stefan-Boltzmann law. Using ε_H values measured, a heat transfer model is developed for determining solar cell and internal glass surface temperatures. It is concluded that the solar cell front and rear emittance, location within the glazing, encapsulation method used and the type of the glazing system affect the solar cell and internal glass temperatures. The second part of this thesis focuses on low temperature (< 150°C) and hermetic encapsulations suitable for the integration of perovskite solar cells in architectural glazing. A review of silicate glass-to-glass bonding technologies and hermetic electrical feedthrough is carried out identifying promising low-temperature techniques. Hydrated sodium silicate “water glass” is then selected as an interlayer for glass-to-glass bonding at low-temperature for encapsulating perovskite solar cells. The influence of bonding parameters on bond strength and encapsulation feasibility are studied and the complete fabrication process is described and durability testing is performed for an encapsulated perovskite layer

El proyecto en la investigación formativa

This article puts in a nutshell what is expressed in a book with a similar title, developed by the authors and is also being published. In this paper develops a way to structure formative research projects in which special emphasis on the problem description with facts, figures and statistics for clarity in its approach is made. Steps are then presented to relate the history and state of the art and how to properly prepare project justification, emphasizing the human, social and environmental impact is required. Also presents a way to develop objectives, ingredients and the importance of checking the feasibility of the project is explained. Likewise, the central aspects relate to develop the theoretical framework, the methodological framework and the budget timeline. Finally, the way the literature and how to present the citations is made is explained.L’article présent met en peu de mots l’exprimé à un livre avec un titre similaire, élaboré par les auteurs et qui est dans un processus de publication également. Dans le présent écrit une forme se développe pour structurer des projets de recherche formative, dans qu’une emphase spéciale est faite dans la description du problème avec données, des chiffres ou les statistiques pour obtenir une clarté dans son établissement. Tout de sui- te les pas se présentent pour rattacher les antécédents et l’état de l’art et on a besoin de la forme d’élaborer d’une manière appro- priée la justification du projet, en privilégiant l’impact humain, social et environnemental. On présente également une forme d’élaborer les objectifs, avec ses composants et il ex- plique l’importance de vérifier la faisabilité du projet. De même, les aspects centraux se rattachent pour élaborer le cadre théorique, le cadre méthodologique et le budget avec le chronogramme.  Finalement,  s’explique la forme dans laquelle est élaborée la bi- bliographie  et  la  forme  de  présenter  les rendez-vous bibliographiques.El presente artículo pone en pocas palabras lo expresado en un libro con título similar,  elaborado por los autores y que está en proceso de publicación igualmente. En el presente escrito se desarrolla una forma para estructurar proyectos de investigación formativa, en el que se hace especial énfasis en la descripción del problema con datos, cifras o estadísticas para obtener claridad en su planteamiento. Luego se presentan los pasos para relacionar los antecedentes y el estado del arte y se precisa la forma de elaborar de manera apropiada la justificación del proyecto, privilegiando el impacto humano, social y ambiental. Igual- mente, se presenta una forma de elaborar los objetivos, con sus componentes y se explica la importancia de verificar la factibilidad del proyecto. Así mismo, se relacionan los aspectos centrales para elaborar el marco teórico, el marco metodológico y el presupuesto con el cronograma. Por último, se explica la forma en que se elabora la bibliografía y la forma de presentar las citas bibliográficas

Human Plasma Metabolomics for Biomarker Discovery: Targeting the Molecular Subtypes in Breast Cancer

Purpose: The aim of this study is to identify differential metabolomic signatures in plasma samples of distinct subtypes of breast cancer patients that could be used in clinical practice as diagnostic biomarkers for these molecular phenotypes and to provide a more individualized and accurate therapeutic procedure. Methods: Untargeted LC-HRMS metabolomics approach in positive and negative electrospray ionization mode was used to analyze plasma samples from LA, LB, HER2+ and TN breast cancer patients and healthy controls in order to determine specific metabolomic profiles through univariate and multivariate statistical data analysis. Results: We tentatively identified altered metabolites displaying concentration variations among the four breast cancer molecular subtypes. We found a biomarker panel of 5 candidates in LA, 7 in LB, 5 in HER2 and 3 in TN that were able to discriminate each breast cancer subtype with a false discovery range corrected p-value &lt; 0.05 and a fold-change cutoff value &gt; 1.3. The model clinical value was evaluated with the AUROC, providing diagnostic capacities above 0.85. Conclusion: Our study identifies metabolic profiling differences in molecular phenotypes of breast cancer. This may represent a key step towards therapy improvement in personalized medicine and prioritization of tailored therapeutic intervention strategies

Human Plasma Metabolomics for Biomarker Discovery: Targeting the Molecular Subtypes in Breast Cancer.

The aim of this study is to identify differential metabolomic signatures in plasma samples of distinct subtypes of breast cancer patients that could be used in clinical practice as diagnostic biomarkers for these molecular phenotypes and to provide a more individualized and accurate therapeutic procedure. Untargeted LC-HRMS metabolomics approach in positive and negative electrospray ionization mode was used to analyze plasma samples from LA, LB, HER2+ and TN breast cancer patients and healthy controls in order to determine specific metabolomic profiles through univariate and multivariate statistical data analysis. We tentatively identified altered metabolites displaying concentration variations among the four breast cancer molecular subtypes. We found a biomarker panel of 5 candidates in LA, 7 in LB, 5 in HER2 and 3 in TN that were able to discriminate each breast cancer subtype with a false discovery range corrected p-value 1.3. The model clinical value was evaluated with the AUROC, providing diagnostic capacities above 0.85. Our study identifies metabolic profiling differences in molecular phenotypes of breast cancer. This may represent a key step towards therapy improvement in personalized medicine and prioritization of tailored therapeutic intervention strategies