Analytical applications of porous cyclodextrin-based materials: a versatile strategy

La presente Tesis Doctoral contempla dos grandes líneas de actuación estrechamente relacionadas entre sí. La primera de ellas consiste en la síntesis, caracterización y modificación de materiales porosos basados en ciclodextrinas para su uso como fases sólidas adsorbentes en técnicas de extracción y muestreo ambiental de compuestos que puedan ser de interés en los campos de la seguridad alimentaria, clínico o medioambiental. La segunda línea de actuación consiste en la puesta a punto de procedimientos analíticos completos con capacidades mejoradas respecto a los ya existentes para la determinación de estos analitos que utilicen como fases sólidas extractantes los materiales desarrollados con anterioridad. La etapa de tratamiento de muestras con diversos orígenes constituye una tarea complicada y a la vez fundamental entre todas las etapas de un análisis químico debido al amplio espectro de interferentes que se pueden presentar en las mismas. Por tanto, el aislamiento, separación y preconcentración de los analitos de interés pueden verse comprometidos por las posibles interacciones de éstos con la matriz de la muestra, dificultando así su extracción y posterior análisis y pudiendo dar lugar de este modo a resultados tanto subestimados como sobreestimados. En este sentido, existe una gran variedad de métodos de adsorción y extracción que hoy en día ayudan al analista en tal fin. Asimismo, una diversidad de fases sólidas se encuentra comercialmente disponibles para llevar a cabo esta tarea, aunque muchas de las tradicionalmente distribuidas son poco selectivas, lo que contribuye en parte a un deterioro de los resultados analíticos obtenidos. Por este motivo, hoy en día se desarrollan constantemente metodologías de extracción, así como nuevos materiales adsorbentes y tratamientos de muestra que refuercen las técnicas instrumentales utilizadas posteriormente. De entre las características de los materiales utilizados que pueden ser moldeadas, la mejora de la selectividad en la adsorción mediante variaciones estructurales de los materiales utilizados se está desarrollando cada vez con más fuerza. Concretamente, el uso de la formación de complejos de inclusión reversibles entre los analitos de interés y las fases sólidas utilizadas es un campo en constante investigación. Las ciclodextrinas son una familia de oligosacáridos cíclicos obtenidas por la unión de monómeros de glucosa unidos por enlaces glicosídicos. Su forma tridimensional se asemeja a la de un cono truncado debido a la asimetría constitucional de los anillos de glucopiranosa, lo que las dota de una cavidad interna hidrofóbica capaz de capturar analitos con propiedades físicas y químicas que los hagan aptos para entrar en la misma con elevada afinidad y una cavidad externa hidrofílica que les facilita su modificación y enlace a distintos tipos de soportes sólidos. Debido a su capacidad de reconocimiento molecular, se han utilizado como nanoportadores en campos tan diversos como las industrias farmacéutica y alimentaria para mejorar las propiedades de los productos fabricados, así como también en medicina para suavizar la intensidad de ciertos tratamientos, focalizando su actuación en las partes del cuerpo humano que sean problemáticas en cada caso. Aunque su estructura y propiedades han sido ampliamente estudiadas desde hace algunas décadas, no ha sido hasta comienzos del siglo XXI cuando su uso en química analítica como parte de materiales adsorbentes para el tratamiento de muestra se empezó a popularizar. Este trabajo se centra por tanto en el estudio de nuevos soportes sólidos conteniendo ciclodextrinas para su aplicación en el campo de la química analítica. En este sentido, tanto la naturaleza del soporte como la de la ciclodextrina utilizada, así como también el tipo de muestra tratada, son los puntos centrales de la investigación llevada a cabo. Las individualidades de cada una y las posibles interacciones de todas estas variaciones entre ellas hacen que las conclusiones extraídas constituyan una contribución al campo de estudio

Grain grinding size of cereals in complete pelleted diets for growing lambs: Effects on ruminal microbiota and fermentation

[EN] Lambs from intensive dairy sheep production systems are sold out either after weaning as milk-fed lambs or after a fattening characterized by high intakes of concentrate feeds (mainly cereals) which can lead to ruminal disorders. Therefore, it is essential to explore different feeding alternatives in order to reach a balance between economic or productive benefits and animal welfare. Twenty weaned male lambs (6–8 weeks age, 14.8 ± 0.16 kg body weight) were allocated randomly to one of two different groups (n=10 per group) to study the effect of feeding a complete pelleted diet (CPD) in which cereal grains were ground at two different sieve sizes (either 2-mm with 13.5% dry matter (DM) of the particles>1.7mm or 6-mm with 47.1% DM of particles>1.7 mm) on DM intake, nutrient digestibility, ruminal microbiota and fermentation. Lambs were fed the corresponding CPD ad libitum and slaughtered when they reached 27 kg. DM intake was greater in the lambs fed 2-mm grains than in those fed 6-mm grains (P < .05). Feeding 2-mm grains in comparison to 6-mm grains resulted in darker colour of ruminal mucosa (100 vs. 127, from a scale where 0 is black and 256 white; SED=9.8; P=.017) and thicker stratum corneum (45.3 vs. 30.9 μm; SED=3.67; P=.001), suggesting more severe acidotic conditions in the rumen with the smaller cereal particle size. Analysis of microbial communities revealed that the presence of ruminal bacteria such as Prevotella and Quinella was increased in the digesta of animals fed the 2-mm diet. These data were corroborated by the odd- and branched-chain fatty acid profile of ruminal contents, which would indicate a shift from cellulolytic to amylolytic bacteria in the rumen of lambs fed the 2-mm diet. In conclusion, feeding 6-mm in comparison to 2-mm ground cereal grains included in CPD formulated for growing lambs is an alternative strategy that may reduce ruminal acidosis through changes in the microbiota.wSICSIC ( (Proyecto Intramural Especial; Project 201540E084)Ministerio de Economía y Competitividad (España

Medicaments i lactància materna

Treballs d'Educació Farmacèutica als ciutadans. Unitat Docent d'Estades en Pràctiques Tutelades. Facultat de Farmàcia, Universitat de Barcelona. Curs: 2015-2016. Tutors: Dolors Soy Muner, Neus Pagès i Marian March Pujol.En el present treball es desenvolupa un programa integral d’educació farmacèutica orientada a les famílies que es trobin en el període de lactància materna al nadó. Els objectius principals del treball són: 1) conscienciar de la importància i beneficis de la lactància materna, 2) aconsellar sobre els aspectes més rellevants per tal de facilitarla mitjançant informació sobre com afrontar els problemes que puguin originar-se, i 3) informar dels possibles efectes que poden ocasionar en el nadó els medicaments, els preparats de fitoteràpia o altres substàncies bioactives que passen a la llet materna. Per tal d’aconseguir-ho, s’han realitzat diferents activitats educatives, tals com una presentació tipus conferència (activitat 1), un vídeo (activitat 2), un tríptic informatiu (activitat 3) i un joc de preguntes (activitat 4)

Analytical Chemistry Laboratory II: Supporting Information Chromatography + Electrochemistry

El document forma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de València.Informació suplementària per a l'assignatura Laboratori de Química Analítica II. Teoria i conceptes bàsics per a les pràctiques corresponents a mètodes cromatogràfics i mètodes electroanalítics.Supplementary information for the subject Analytical Chemistry Laboratory II. Theory and basic concepts on the practicals corresponding to chromatographic and electroanalytical methods

First record of a Black Vulture (Coragyps atratus) nesting in Buenos Aires province

Wereporta nest of Black Vultures,the first for Buenos Aires Province.It was found on the ground in a coastal sand dune,covered by the endemic bush Neosparton darwinii

Bimodal porous silica nanomaterials as sorbents for an efficient and inexpensive determination of aflatoxin M1 in milk and dairy products

An extraction procedure was developed for the determination of aflatoxin M1 in milk and dairy products. A sorbent based on UVM-7 mesoporous silica was used as solid phase for the sample clean-up, and the analyte determination was carried out by HPLC coupled to a fluorescence detector. The material architecture was characterized by transmission electronic microscopy, X-ray diffraction, 29Si NMR and nitrogen adsorption-desorption. After the optimization of extraction parameters, the influence of the matrix has been evaluated, obtaining recoveries in the range 78-105% for whole and skimmed milk and yogurt matrix. The reusability of the material was also proved. The sensitivity of the method was also evaluated, and a LOQ (0.015 μg kg−1) below the European legislation limit was obtained. The procedure was successfully applied for the determination of aflatoxin M1 in real samples. The results were compared with those obtained with a reference method, being the results statistically comparabl

Cyclodextrins as a Key Piece in Nanostructured Materials: Quantitation and Remediation of Pollutants

Separation and pre-concentration of trace pollutants from their matrix by reversible formation of inclusion complexes has turned into a widely studied field, especially for the benefits provided to different areas. Cyclodextrins are non-toxic oligosaccharides that are well known for their host&ndash;guest chemistry, low prices, and negligible environmental impact. Therefore, they have been widely used as chiral selectors and delivery systems in the pharmaceutical and food industry over time. However, their use for extraction purposes is hampered by their high solubility in water. This difficulty is being overcome with a variety of investigations in materials science. The setting-up of novel solid sorbents with improved properties thanks to the presence of cyclodextrins at their structure is still an open research area. Some properties they can offer, such as an increased selectivity or a good distribution along the surface of a solid support, which provides better accessibility for guest molecules, are characteristics of great interest. This systematic review reports the most significant uses of cyclodextrins for the adsorption of pollutants in different-origin samples based on the works reported in the literature in the last years. The study has been carried out indistinctly for quantitation and remediation purposes

Embedded Fiber Bragg Grating Sensors for Monitoring Temperature and Thermo-Elastic Deformations in a Carbon Fiber Optical Bench

A composite optical bench made up of Carbon Fiber Reinforced Polymer (CFRP) skin and aluminum honeycomb has been developed for the Tunable Magnetograph instrument (TuMag) for the SUNRISE III mission within the NASA Long Duration Balloon Program. This optical bench has been designed to meet lightweight and low sensitivity to thermal gradient requirements, resulting in a low Coefficient of Thermal Expansion (CTE). In addition to the flight model, a breadboard model identical to the flight one has been manufactured, including embedded fiber Bragg temperature and strain sensors. The aim of this is to explore if the use of distributed fiber Bragg gratings (FBGs) can provide valuable information for strain and temperature mapping of an optical instrument on board a space mission during its operation as well as its on-ground testing. Furthermore, surface-mounted strain FBG sensors and thermocouples have been installed in the optical bench for intercomparison purposes. This paper presents the results obtained from a thermal vacuum test consisting of three thermal cycles with stabilization steps at 100 °C, 60 °C, 20 °C and −20 °C. Experimental results provide information about how FBG embedded temperature sensors can provide a proper and quick response to the temperature changes of the optical bench and that embedded FBG strain sensors are able to measure micro-deformation induced in a close-to-zero CTE optical bench.AEI/MCIN/10.13039/501100011033Depto. de ÓpticaFac. de Óptica y OptometríaTRUEpu

Study of silica-structured materials as sorbents for organophosphorus pesticides determination in environmental water samples

A novel sorbent based on a UVM-7 mesoporous silica doped with Ti has been synthesized and used for solid-phase extraction of several organophosphorus pesticides in environmental water samples followed by gas chromatography coupled to a nitrogen-phosphorus selective detector. Thus, mesoporous silica materials doped with Ti and Fe as well as immobilized cyclodextrin silica-based supports were prepared and morphologically characterized by several techniques such as transmission electronic microscopy, nitrogen adsorption-desorption and X-ray diffraction. These sorbents were comparatively evaluated, and Ti25-UVM-7 material was selected as the best solid phase. After optimization of extraction parameters such as amount of solid-phase, type and volume of eluent, pH and ionic strength and breakthrough volume, recoveries between 81% and 104.5% were achieved, with RSD values below 7.8% and 12% for intra-day and inter-day repeatability respectively. Moreover, limits of quantification in the range 0.5-4.4 μg L−1 were achieved for all target compounds using mass spectrometry detector. In addition, the developed method was applied for analysis of real water samples and it was validated with commercial C18 cartridges. Matrix effect was demonstrated in complex environmental matrices and the good reusability of synthesized material was also proved