The doctoral thesis is aimed at research of application possibilities of low-temperature co-fired ceramics, especially its non-conventional usage. It deals with particular topics ensue from electronic chips package design. The thesis also touches optoelectronic sensor application of this ceramics.

[EN] Nowadays, due to the fast development of wireless communication systems, the need to have radiating elements has arisen. These elements allow an efficient radiation of electromagnetic waves that transmit the information among the different points of the system. Owing to this growing demand and based on certain requirements, several prototype antennas fabricated with planar technologies such as PCB "Printed Circuit Board" and LTCC "Low Temperature Co-fired Ceramic" are presented in this thesis. Every proposed prototype is presented as a solution for a project which requires an antenna with specific characteristics. Based on the requested specifications such as working frequency, bandwidth, polarization type, size and shape, the most appropriate design alternatives were selected. For satellite communications at 5.8 GHz, two types of antennas with circular polarization are proposed. The former is a square patch with a diagonal slot, the latter is a polarization reconfigurable antenna fabricated with LTCC technology. For the operation in Ku band at 17 GHz, slot arrays with substrate integrated waveguide technology were proposed, whereas for vehicular applications, monopole antennas were the better solution due to the restrictions in the form and space available for assembly. In addition, due to the growing interest in the applications operating at no licensed frequency bands, patch antenna arrays conformed in a cylindrical shape to operate at 2.4 GHz and 5.8 GHz, were designed. These arrays will be placed in UAVs. Each proposed design meets with the required specifications for the different projects such as: appropriate matching levels, radiation patterns according to the application, specific dimensions and material type / [ES] En la actualidad, con el rápido desarrollo de los sistemas de comunicaciones inalámbricos, se presenta la necesidad de contar con elementos radiantes que permitan la radiación eficiente de las ondas electromagnéticas que transportan la información. Ante la creciente demanda y en base a ciertos requerimientos, en esta tesis se presentan varios prototipos de antenas fabricados con tecnologías planares como PCB "Printed Circuit Board" y LTCC "Low Temperature Co-fired Ceramic". Cada prototipo que se propone, se plantea como solución para proyectos que requieren que la antena presente determinadas características. En base a las especificaciones solicitadas como: frecuencia de trabajo, ancho de banda, tipo de polarización, tamaño y forma, se buscaron las alternativas de diseño más apropiadas. Para aplicaciones satelitales a 5.8 GHz se proponen dos tipos de antenas con polarización circular: la primera que es un parche cuadrado con ranura inclinada y la segunda que es una antena reconfigurable en polarización fabricada con tecnología LTCC. Para operar en la banda Ku a 17 GHz, se propuso utilizar agrupaciones de ranuras en guía de onda integrada en sustrato, mientras que para aplicaciones vehiculares, los monopolos fueron las antenas que mejor se adaptaron a las formas y espacios disponibles para su montaje. Además, por el gran interés que han despertado las aplicaciones que operan en bandas de frecuencia que no requieren de permiso o licencia para su utilización, se diseñaron agrupaciones de antenas tipo parche conformados a una forma cilíndrica para operar a 2.4 GHz y 5.8 GHz. Estas agrupaciones serán ubicadas en vehículos aéreos no tripulados. Cada diseño propuesto cumple con especificaciones planteadas por las necesidades de los diferentes proyectos como: niveles adecuados de adaptación, diagramas de radiación acorde con la aplicación, dimensiones y material específico. / [CA] En l'actualitat, amb el ràpid desenvolupament dels sistemes de comunicacions sense fils, es presenta la necessitat de comptar amb elements radiants que permitisquen la radiació eficient de les ones electromagnètiques que transporten la informació. Davant la creixent demanda y en base a certs requeriments, en aquesta tesi es presenten diversos prototips d'antenes fabricades amb tecnologies planars com PCB "Printed Circuit Board" i LTCC "Low Temperature Co-fired Ceramic". Cada prototip que es proposa es planteja com a solució per projectes que requereixen que l'antena presente determinades característiques. D'acord amb les especificacions sol·licitades, com poden ser la freqüència de treball, l'ample de banda, el tipus de polarització, o la mida y la forma, es buscaren les alternatives de disseny més apropiades. Per aplicacions satel·litals, a 5.8 GHz es proposen dos tipus d'antenes amb polarització circular: la primera és una antena plana "patch antena" quadrada amb ranura inclinada y la segona és una antena reconfigurable en polarització fabricada amb tecnologia LTCC. Per tal d'operar a la banda Ku a 17 GHz, es va proposar utilitzar agrupacions de ranures en guia d'ona integrada en substrat, mentre que per aplicacions vehiculars, el monopols foren les antenes que millor s'adaptaren a les formes y espais disponibles per al seu muntatge. A més a més, pel gran interès que han despertat les aplicacions que operen en bandes de freqüència que no requereixen de permís o llicència per a la seua utilització, es dissenyaren agrupacions d'antenes planes conformades a una forma cilíndrica per operar a 2.4 GHz i 5.8 GHz. Estes agrupacions seran ubicades en vehicles aeris no tripulats. Cada disseny proposat compleix amb les especificacions plantejades per les necessitats dels diferents projectes com: nivells adequats d'adaptació, diagrames de radiació d'acord amb l'aplicació, dimensions i material específic. / Navarro Méndez, DV. (2015). NUEVOS SISTEMAS RADIANTES REALIZADOS CON TECNOLOGÍAS IMPRESAS [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/54118

Compromised calcium homeostasis in the central nervous system (CNS) is implicated as a major contributor in the pathology of neurodegeneration. Dysregulation of Ca2+ homeostasis initiates downstream Ca2+–dependent events that lead to apoptotic and/or necrotic cell death. Increases in the intracellular free calcium concentration ([Ca2+]i) may be the result of Ca2+ influx from the extracellular environment or Ca2+ release from intracellular Ca2+ stores such as the endoplasmic reticulum (ER). Influx from the extracellular environment is controlled predominantly by voltage gated calcium channels (VGCC), such as L–type calcium channels (LTCC) and ionotropic glutamate receptors, such as the N–methyl–D–aspartate (NMDA) receptors. Ca2+ release from the ER occurs through the inositol–1,4,5–triphosphate receptors (IP3Rs) or ryanodine receptors (RyRs) via IP3–induced or Ca2+–induced mechanisms. Mitigation of Ca2+ overload through these Ca2+ channels offers an opportunity for pharmacological interventions that may protect against neuronal death. In the present study the ability of a novel series of polycyclic compounds, both the pentacycloundecylamines and triquinylamines, to regulate calcium influx through LTCC was evaluated in PC12 cells using calcium imaging with Fura–2/AM in a fluorescence microplate reader. We were also able for the first time to determine IC50 values for these compounds as LTCC blockers. In addition, selected compounds were evaluated for their ability to offer protection in apoptosis–identifying assays such as the lactate dehydrogenase release assay (LDH–assay), trypan blue staining assay and immunohistochemistry utilizing the Annexin V–FITC stain for apoptosis. We were also able to obtain single crystal structures for the tricyclo[6.3.0.02,6]undecane–4,9–dien–3,11–dione (9) and tricyclo[6.3.0.02,6]undecane–3,11–dione (10) scaffolds as well as a derivative, N–(3–methoxybenzyl)–3,11–azatricyclo[6.3.0.02,6]undecane (14f). We also evaluated the possibility that the polycyclic compounds might be able to modulate Ca2+ flux through intracellular Ca2+ channels. Computational methods were utilized to accurately predicted IC50 values and develop a QSAR model with marginal error. The linear regression model delivered r2 = 0.83, which indicated a favorable correlation between the predicted and experimental IC50 values. This model could thus serve as valuable predictor for future structural design and optimization efforts. Data obtained from the crystallographic analysis confirmed the NMR–data based structural assignments done for these compounds in previous studies. Obtaining structural information gave valuable insight into the differences in size and geometric constrains, which are key features for the LTCC activity of these compounds. vii In conclusion, we found that all of the compounds evaluated were able to attenuate Ca2+ influx through the LTCC, with some compounds having IC50 values comparable with known LTCC blockers such as nimodipine. Representative compounds were evaluated for their ability to afford protection against apoptosis induced by 200 ?M H2O2. With the exception of compound 14c (the most potent LTCC blocker in the series, IC50 = 0.398 ?M), most compounds were able to afford protection at two or more concentrations evaluated. Compound 14c displayed inherent toxicity at the highest concentrations evaluated (100 ?M). We concluded that compounds representing both types of structures (pentacycloudecylamines and triquinylamines) have the ability to attenuate excessive Ca2+ influx through the LTCC. In general the aza–pentacycloundecylamines (8a–c) were the most potent LTCC blocker which also had the ability to offer protection in the cell viability assays. However, NGP1–01 (7a) had the most favorable pharmacological profile overall with good activity as an LTCC blocker (IC50 = 86 ?M) and the ability to significantly attenuate cell death in the cell viability assays, exhibiting no toxicity. In addition to their ability to modulate Ca2+ influx from the extracellular environment, these compounds also displayed the ability to modulate Ca2+ flux through intracellular Ca2+ channels. The mechanisms by which they act on intracellular Ca2+ channels still remains unclear, but from this preliminary study it would appear that these compounds are able to partially inhibiting Ca2+–ATPase activity whilst possibly simultaneously inhibiting the IP3R. In the absence of extracellular Ca2+ these compounds showed the ability in inhibit voltage–induced Ca2+ release (VICaR), possibly by modulating the gating charge of the voltage sensor being the dihydropyridine receptors. In future studies it might be worthwhile to do an expanded QSAR study and evaluate the aza–pentacycloundecylamines. To clarify the mechanisms by which the polycyclic compounds interact with intracellular Ca2+ channels we should examine the direct interaction with the individual Ca2+ channels independently. The polycyclic compounds evaluated in this study demonstrate potential as multifunctional drugs due to their ability to broadly regulate calcium homeostasis through multiple pathways of Ca2+ entry. This may prove to be more effective in diseases where perturbed Ca2+ homeostasis have devastating effects eventually leading to excitotoxicity and cell death. / Thesis (Ph.D. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2012.

Compromised calcium homeostasis in the central nervous system (CNS) is implicated as a major contributor in the pathology of neurodegeneration. Dysregulation of Ca2+ homeostasis initiates downstream Ca2+–dependent events that lead to apoptotic and/or necrotic cell death. Increases in the intracellular free calcium concentration ([Ca2+]i) may be the result of Ca2+ influx from the extracellular environment or Ca2+ release from intracellular Ca2+ stores such as the endoplasmic reticulum (ER). Influx from the extracellular environment is controlled predominantly by voltage gated calcium channels (VGCC), such as L–type calcium channels (LTCC) and ionotropic glutamate receptors, such as the N–methyl–D–aspartate (NMDA) receptors. Ca2+ release from the ER occurs through the inositol–1,4,5–triphosphate receptors (IP3Rs) or ryanodine receptors (RyRs) via IP3–induced or Ca2+–induced mechanisms. Mitigation of Ca2+ overload through these Ca2+ channels offers an opportunity for pharmacological interventions that may protect against neuronal death. In the present study the ability of a novel series of polycyclic compounds, both the pentacycloundecylamines and triquinylamines, to regulate calcium influx through LTCC was evaluated in PC12 cells using calcium imaging with Fura–2/AM in a fluorescence microplate reader. We were also able for the first time to determine IC50 values for these compounds as LTCC blockers. In addition, selected compounds were evaluated for their ability to offer protection in apoptosis–identifying assays such as the lactate dehydrogenase release assay (LDH–assay), trypan blue staining assay and immunohistochemistry utilizing the Annexin V–FITC stain for apoptosis. We were also able to obtain single crystal structures for the tricyclo[6.3.0.02,6]undecane–4,9–dien–3,11–dione (9) and tricyclo[6.3.0.02,6]undecane–3,11–dione (10) scaffolds as well as a derivative, N–(3–methoxybenzyl)–3,11–azatricyclo[6.3.0.02,6]undecane (14f). We also evaluated the possibility that the polycyclic compounds might be able to modulate Ca2+ flux through intracellular Ca2+ channels. Computational methods were utilized to accurately predicted IC50 values and develop a QSAR model with marginal error. The linear regression model delivered r2 = 0.83, which indicated a favorable correlation between the predicted and experimental IC50 values. This model could thus serve as valuable predictor for future structural design and optimization efforts. Data obtained from the crystallographic analysis confirmed the NMR–data based structural assignments done for these compounds in previous studies. Obtaining structural information gave valuable insight into the differences in size and geometric constrains, which are key features for the LTCC activity of these compounds. vii In conclusion, we found that all of the compounds evaluated were able to attenuate Ca2+ influx through the LTCC, with some compounds having IC50 values comparable with known LTCC blockers such as nimodipine. Representative compounds were evaluated for their ability to afford protection against apoptosis induced by 200 ?M H2O2. With the exception of compound 14c (the most potent LTCC blocker in the series, IC50 = 0.398 ?M), most compounds were able to afford protection at two or more concentrations evaluated. Compound 14c displayed inherent toxicity at the highest concentrations evaluated (100 ?M). We concluded that compounds representing both types of structures (pentacycloudecylamines and triquinylamines) have the ability to attenuate excessive Ca2+ influx through the LTCC. In general the aza–pentacycloundecylamines (8a–c) were the most potent LTCC blocker which also had the ability to offer protection in the cell viability assays. However, NGP1–01 (7a) had the most favorable pharmacological profile overall with good activity as an LTCC blocker (IC50 = 86 ?M) and the ability to significantly attenuate cell death in the cell viability assays, exhibiting no toxicity. In addition to their ability to modulate Ca2+ influx from the extracellular environment, these compounds also displayed the ability to modulate Ca2+ flux through intracellular Ca2+ channels. The mechanisms by which they act on intracellular Ca2+ channels still remains unclear, but from this preliminary study it would appear that these compounds are able to partially inhibiting Ca2+–ATPase activity whilst possibly simultaneously inhibiting the IP3R. In the absence of extracellular Ca2+ these compounds showed the ability in inhibit voltage–induced Ca2+ release (VICaR), possibly by modulating the gating charge of the voltage sensor being the dihydropyridine receptors. In future studies it might be worthwhile to do an expanded QSAR study and evaluate the aza–pentacycloundecylamines. To clarify the mechanisms by which the polycyclic compounds interact with intracellular Ca2+ channels we should examine the direct interaction with the individual Ca2+ channels independently. The polycyclic compounds evaluated in this study demonstrate potential as multifunctional drugs due to their ability to broadly regulate calcium homeostasis through multiple pathways of Ca2+ entry. This may prove to be more effective in diseases where perturbed Ca2+ homeostasis have devastating effects eventually leading to excitotoxicity and cell death. / Thesis (Ph.D. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2012.