Detection of 2-photon photosensitized singlet oxygen in hollow-core photonic crystal fibres

Photosensitized production of singlet oxygen is used in the treatment of cancer by photodynamic therapy (PDT), in which a photosensitizer is administered and excited locally in the tumour tissue, generating singlet oxygen to destroy, selectively, malignant cells. The use of two-photon excitation (2PE) in PDT has significant advantages in achieving enhanced spatial selectivity and greater depth of penetration through tissue. This is driving the development of new photosensitizers with high 2-photon cross-sections, but progress is inhibited by the difficulty of determining, in vitro, the efficiency of singlet oxygen production in response to TPE. In conventional experiments, the extremely high photon flux needed to achieve two-photon absorption is created by focusing a pulsed laser beam into a spot of about 1 μm in diameter. This minuscule (femtolitre) excitation volume makes the detection of two-photon-induced singlet oxygen generation extremely challenging. This thesis describes the development of an optofluidic system for the measurement of singlet oxygen quantum yields under 2PE, using hollow-core photonic crystal fibre (HC-PCF). HC-PCF allows the guidance of light in a well-defined fundamental mode within the hollow core, sustaining 2PE over long path lengths. When the fibre core is filled with photosensitizer solution, the intense light-matter interaction over a long path length enables ultra-sensitive detection of singlet oxygen. In the present work, the detection was achieved using a singlet oxygen-specific fluorescent probe, singlet oxygen sensor green (SOSG), employing a two-colour pump-probe methodology, with an 800-nm pump beam (2PE of photosensitizer) and a 488-nm probe beam (excitation of fluorescent probe) co-coupled into the hollow core of the fibre. Using this approach, it was possible to detect quantitatively singlet oxygen produced by 2PE of sub-micromolar concentrations ofphotosensitizer in an aqueous solution. The efficiency of singlet oxygen generation for a variety of PSs, including aluminium (III) phthalocyanine chloride tetrasulfonate chloride (AlPcS4), Meso-tetrakis (4-sulfonatophenyl) tetrasulfonate porphyrin (TPPS4), Protoporphyrin IX (PPIX), Zinc phthalocyanine tetrasulfonate (ZnPcS4), Chlorin E6 (CE6), Flavin Mononucleotide (FMN) and Hypericin (Hyp), was measured relative to a reference standard, Rose Bengal (RB). The parameter obtained directly from these measurements was the product of the cross-section for two-photon absorption (2PA) and the singlet oxygen quantum yield. To extract the value of the 1O2 quantum yield, the 2PA cross-section was measured in separate, cuvette-based experiments. 2PA cross-sections were determined by measuring the two-photon brightness (product of 2PA cross-section and fluorescence quantum yield) of the PS relative to a standard fluorescent dye. To extract the value of the 2PA cross-section, the fluorescence quantum yield was measured, under one-photon excitation. For many of the PSs, this was the first time that the 2PA cross-section had been determined in biologically relevant, aqueous conditions. In some cases, aggregation effects were seen, where the 2PA cross-section value depended on the concentration of the PS. Singlet oxygen quantum yields were also measured under one-photon excitation, in cuvette experiments, using SOSG, to provide reference values for comparison with those measured under 2PE in HC-PCF. These experiments also revealed the effects of aggregation on singlet oxygen quantum yields. The work presented in this thesis has demonstrated, for the first time, that the unique optofluidic properties of hollow-core photonic crystal fibre enable singlet oxygen quantum yields of two-photon-excited photosensitizers to be measured, under conditions relevant to clinical application, in aqueous solution and using low pulse-energy excitation

Medicion de la sensacion de confort operativo a estudiantes del curso de transferencia de calor utilizando como mediador didactico un simulador de sotfware para procesos de transferencia de calor

TablasEl presente trabajo responde a las inquietudes expresadas por parte de estudiantes y tutores que son usuarios de la mediación virtual en cursos metodológicos que ofrece la Universidad Nacional Abierta y a Distancia UNAD. Se encuentra dividido en unidades las cuales son: Unidad 1. Título del trabajo de investigación el cual indica el problema de investigación abordado y que está enmarcado dentro de las líneas de investigación de la ECBTI. Unidad 2. La justificación del problema de investigación , en el cual se propone encontrar diferencias en habilidades procedimentales entre dos grupos de estudiantes que utilizaron un simulador de laboratorio virtual, disponible en el campus de la UNAD y otro grupo que utilizó prácticas de laboratorio tradicional. Unidad 3. Muestra los objetivos general y específicos que se pretender alcanzar on el trabajo de investigación. Unidad 4. Se muestra el planteamiento del problema que se presenta al interior de la mediación virtual. Unidad 5. Se muestra la metodología utilizada. Unidad 6. Se muestra el estado del arte en simuladores en la ingeniería química.This paper responds to the concerns expressed by students and tutors who are users of the virtual mediation courses methodological featuring the National Open and Distance University UNAD . It is divided into units which are: Unit 1 . Title of the research work which indicates the problem addressed research and is framed within lines ECBTI research . Unit 2 . The justification of the research problem , which is proposed find differences in procedural skills between two groups Students who used a virtual lab simulator , available at UNAD campus and another group using traditional laboratory practices . Unit 3 . Displays the general and specific objectives that hope to achieve on the research work . Unit 4 . The problem statement presented within Shown virtual mediation . Unit 5 . The methodology used is displayed. Unit 6 . The art shown in simulators in chemical engineerin

Fatty Acids on Osteoclastogenesis

Excessive bone resorption is a hallmark on the onset and development of bone diseases, including osteoporosis, periodontitis, and rheumatoid arthritis. Osteoclasts are bone‐resorbing multinucleated cells that differentiate from hematopoietic progenitors of the myeloid lineage. The regulation of this differentiation process is considered an effective therapeutic intervention to the treatment of pathological bone loss. Dietary fatty acids (FAs), transported in the form of postprandial triglyceride‐rich lipoproteins, have been linked with inflammation and oxidative stress associated to the overactivation of circulating leukocytes. Monocyte differentiation by soluble cytokines is known to up‐regulate osteoclast maturation via increased expression levels of receptor activator for nuclear factor‐κB ligand relative to osteoprotegerin. This review summarizes the effects of dietary omega‐3 long‐chain polyunsaturated fatty acids, monounsaturated fatty acids, and saturated fatty acids on plasticity during osteoclast formation and function

Plan de marketing para el lanzamiento de F5 producciones

F5 Producciones. Será una empresa dedicada al audio y video ubicada en la ciudad de Bogotá, siendo la creación de jingle musicales su principal actividad las cuales irán dirigidas a empresas de audio y video, artistas y productores musicales. En F5 se caracteriza por ofrecer a sus clientes trabajos de alta calidad, ya que contaremos con equipo de última tecnología para la elaboración de los jingles, ofreceremos gran respaldo y garantía de los servicios vendidos a nuestros clientes, siendo estas grandes ventajas que nos diferencian del mercado actual. Nuestra empresa tiene como objetivo Incursionar en el mercado nacional con productos y servicios de calidad, contando con un excelente recurso humano y con productos de calidad, brindando para ellos equipos de última tecnología y así lograr nuestro posicionamiento. Realizar los mejores jingles musicales y comerciales, entregándolos a tiempo y con excelente calidad para así lograr reconocimiento. F5 contara con un gerente general el cual estará a cargo de los clientes y manejo de la empresa, estará siempre al tanto de cada uno de los servicio solicitados y será quien se encargue de dar el visto final cada una de los servicio ya listos para ser entregados al cliente. Se contara también con personas expertas en el tema de sonido, arreglos musicales, entre otros. Aunque este tipo de personal no estará incluido en el nomina, se les pagara por trabajo o labor, sin dejar a un lado la posibilidad de ser contratados directamente

Nutrigenomics and Atherosclerosis: The Postprandial and Long-Term Effects of Virgin Olive Oil Ingestion

Metals technology / metallurg

Chapter Beyond Dietary Fatty Acids as Energy Source: A Point of View for the Prevention and Management of Type 2 Diabetes

Medical genetic

Membrane composition and dynamics: A target of bioactive virgin olive oil constituents

AbstractThe endogenous synthesis of lipids, which requires suitable dietary raw materials, is critical for the formation of membrane bilayers. In eukaryotic cells, phospholipids are the predominant membrane lipids and consist of hydrophobic acyl chains attached to a hydrophilic head group. The relative balance between saturated, monounsaturated, and polyunsaturated acyl chains is required for the organization and normal function of membranes. Virgin olive oil is the richest natural dietary source of the monounsaturated lipid oleic acid and is one of the key components of the healthy Mediterranean diet. Virgin olive oil also contains a unique constellation of many other lipophilic and amphipathic constituents whose health benefits are still being discovered. The focus of this review is the latest evidence regarding the impact of oleic acid and the minor constituents of virgin olive oil on the arrangement and behavior of lipid bilayers. We highlight the relevance of these interactions to the potential use of virgin olive oil in preserving the functional properties of membranes to maintain health and in modulating membrane functions that can be altered in several pathologies. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy

Study of the effects of thermally thin and thermally thick particle approaches on the Eulerian modeling of a biomass combustor operating with wood chips

Two particle treatments, thermally thin and thick, are applied to Eulerian combustion modeling for biomass packed beds and tested through the simulation of an experimental plant. The paper shows the efficiency of the Eulerian approach for large packed beds and tests the behavior of both particle treatments, tested with in-bed and flame temperatures and released volatiles measurements at different locations, which is not common in the literature for a full size boiler. Both approaches are implemented in a model with a comprehensive framework that includes several submodels for the thermal conversion kinetics, bed motion, heat and mass transfer with the gas phase, and gas flow and reaction. Two experiments are performed with wood chips fuels with different moisture contents. The simulations of the two cases result in reasonably good predictions for both particle treatments. The results are similar for higher moisture content and, for the low-moisture test, the bed temperature distribution and reaction fronts are slightly different due to the different predictions of the drying and devolatilization fronts. The volatile measurements show that the T. Thin model results in slightly more accurate predictions than the T. Thick, possibly because the wood chips have a more thermally thin behaviorMinisterio de Ciencia, Innovación y Universidades | Ref. PID2021-126569OB-I00Universidade de Vigo/CISU