Efecto de la radiación visible sobre la supervivencia de Acinetobacter baumannii sobre soportes inertes

Acinetobacter baumannii es una bacteria de gran importancia clínica debido a las infecciones nosocomiales a las que se asocia. La amenaza que supone en el ámbito hospitalario está directamente relacionada con su capacidad para sobrevivir a condiciones hostiles tales como cambios de temperatura, estrés lumínico y sequedad. En este contexto, se ha estudiado el efecto de la radiación visible sobre poblaciones de A. baumannii (ATCC 19606) mantenidas a temperatura ambiente en medio líquido (condiciones de ayuno) y sobre soporte sólido (condiciones de ayuno y sequedad). Para determinar la posible pérdida de cultivabilidad y la entrada en estado viable no cultivable (VNC), las poblaciones de A. baumannii se inocularon en solución salina estéril o se fijaron a filtros de acetato de celulosa estériles y se incubaron a 20ºC en condiciones de oscuridad (control) o exposición a luz visible. A lo largo de la supervivencia, utilizando microscopía de epifluerescencia, se cuantificaron las células totales, viables y cultivables. Además, se determinó la capacidad de formar biofilms de estas poblaciones. Bajo condiciones de oscuridad, tanto en soportes sólidos como en medio líquido, no se detectó pérdida de cultivabilidad, actividad o integridad celular durante al menos 7 días. Sin embargo, la luz visible tuvo un efecto negativo sobre las poblaciones de A. baumannii expuestas tanto en medio líquido como sobre soporte sólidos. En medio líquido, si bien la radiación luminosa no afectó a la integridad celular, al finalizar el periodo de exposición (7 días) el número de células cultivables descendió 1,5 log y el 27% de la población se encontraba en estado VNC. En condiciones de sequedad, la pérdida de cultivabilidad se detectó ya desde el primer día de exposición, situándose por debajo del límite de detección tras 5 días; la densidad de células viable también disminuyó, de modo que tras 7 días de exposición el 4% de la población era VNC. Además, la capacidad de formar biofilms se vio negativamente afectada a lo largo de la permanencia tanto en luz como en oscuridad. El efecto negativo de la luz fue especialmente relevante en poblaciones mantenidas en soportes sólidos. Bajo condiciones de ayuno, A. baumannii es capaz de persistir durante periodos de tiempo de al menos una semana incluso en ausencia de humedad. Sin embargo, la exposición de radiación luminosa induce la entrada en estado VNC en estas mismas condiciones, siendo este efecto negativo más acusado en condiciones de ayuno y sequedad.

Efecto de la radiación visible sobre la supervivencia de Vibrio harveyi en el medio marino

Vibrio harveyi es un microorganismo marino perteneciente a la familia Vibrionaceae, patógeno de numerosos animales marinos; tanto invertebrados como vertebrados, pudiendo producir pérdidas económicas en países que se benefician de la acuicultura. Se trata de un microorganismo que vive en un medio natural con escasa cantidad de nutrientes, por ello es un microorganismo oligotrofo. Además el medio marino es un medio con una gran cantidad de sales, con lo cual V. harveyi es una bacteria halófila. 3 V. harveyi es capaz de entrar en lo que se conoce como estado Viable No Cultivable (VNC), en dicho estado es capaz de sobrevivir a situaciones de estrés manteniendo niveles bajos de actividad y perdiendo la cultivabilidad. La radiación luminosa visible, a pesar de tener efectos beneficiosos en los seres vivos, puede provocar efectos negativos en las poblaciones microbianas marinas. En este trabajo se determinó la entrada en estado VNC en sus condiciones de temperatura ambiente (20ºC) tanto en un control en oscuridad así como bajo estrés lumínico. Los resultados mostraron como las células mantenidas en oscuridad no entraron en estado VNC, aunque sí se produjo una pérdida de cultivabilidad relacionada con lesiones celulares provocadas por los nutrientes de determinados medios de cultivo. En cambio, las células que fueron expuestas a la luz visible indicaron una pérdida de cultivabilidad a lo largo de los días de exposición, manteniéndose al finalizar el trabajo experimental el 93% de la población en estado VNC. Por lo tanto, la luz visible provoca un efecto negativo en la población de V. harveyi que es capaz de mantenerse en un estado VNC para sobrevivir a las condiciones adversas.

Respuesta a la sequía de Pinus radiata D. Don y su implicación en los procesos de tolerancia

160 p. (Bibliogr. 141-160)

Ajuste psicológico y salud mental de la población inmigrante : influencia del género y la cultura

481 p.

Diplodia pinea (Desm.) Kickx y Fusarium circinatum Niremberg & O'Donell, principales hongos de chancro de las masas forestales de Pinus radiata D. Don del País Vasco

228 p.

Mecanismos fisiológicos de respuesta de la cebada al impacto de la sequía y el elevado CO2 : adaptación al cambio climático

251 p. : il., col.

¿Actores o consumidores de imágenes?

Revista con LCC: Reconocimiento – NoComercial – SinObraDerivada (by-nc-nd)

Análisis del coste energético de la osmorregulación en el decápodo Pachygrapsus marmoratus

El crustáceo decápodo Pachygrapsus marmoratus , conocido como "cangrejo corredor" o "cangrejo zapatero", es un organismo que habita en la zona intermareal rocosa de la costa. No se caracteriza precisamente por su interés económico pero resulta muy útil para el análisis de ciertas variables fisiológica s relacionadas con su modo de vida. En su condición de osmorregulador eurihalino, es capaz de regular los cambios bruscos de salinidad a los que se encuentra sometido debido , principalmente , a la acción de las mareas . Es evidente que la regulación del medi o inte rno implica un gasto energético que se ve traducido en un aumento de la t asa metabólica. En este estudio se aborda el análisis del coste energético de la osmorregulación cuando estos animales son sometidos a diferentes salinidad es así como la influen cia que tienen otras variables, tales como la masa corporal y el tiempo que transcurren los animales en dicha condición , sobre la tasa metabólica en un proceso de aclimatación. Debido a su gran importancia tanto fisiológica como ecológica, en el presente estudio se trata de analizar la relación alométrica que presentan el peso y el metabolismo a fin de evaluar en qué medida influye la talla de los organismos sobre éste último. T al y como se esperaba la salinidad presenta un efecto claro sobre el metabolismo puesto que una dilución de ésta supone un aumento en la tasa de consumo de oxígeno. Por otro lado, la influencia de la masa corporal y del tiempo es también muy notoria ya que a medida que transcurren los días expuestos a la nueva condición , los cangrejos de mayor tamaño registran tasas de consumo de oxígeno que van en aumento mientras que los de pequeño tamaño descienden sus tasas de consumo de oxígeno. Cabe destacar que el he cho de haber estado expuestos a las condiciones del laboratorio, lugar en el que son mantenidos los ejemplares de este crustáceo, hace que estén sometidos a un estrés continuo que puede influenciar en menor medida , las tasas metabólicas analizadas.

Mindfulness: guía práctica para educadores

[ES] Esta guía está dirigida a docentes del ámbito de la educación tanto formal como no formal que se apunten a un curso de mindfulness para liberar su estrés, ansiedad… y poder llevar así una vida más sana. No obstante, también se puede aplicar para educadores de educación informal, a saber, a todo tipo de personas que quieran vivir mejor a nivel físico-psíquico. Los objetivos de esta guía del mindfulness son los siguientes: -Aprender qué es y en qué consiste el mindfulness. -Aprender a meditar -Conocer los beneficios que aporta el mindfulness a nivel neurobiológico, físico y psíquico. Aprender a afrontar las emociones negativas. -Aprender a reconocer nuestras emociones -Aprender a relajarnos en momentos en los que nos sintamos tensos -Aprender a aplicar el mindfulness con nuestr@s hij@s (ejercicios prácticos)

Papel de E2F1 y E2F2 en la instauración de esteatosis inducida por dieta rica en grasa

Los factores de transcripción E2F son cruciales en la transición G1/S del ciclo celular. El factor de transcripción E2F1 regula el metabolismo oxidativo y su falta genera resistencia a obesidad. Se desconoce si E2F1 y E2F2 están implicados en la regulación de la homeostasis metabólica hepática. Por ello, el objetivo fue investigar el papel de E2F1 y E2F2 en la modulación del metabolismo lipídico hepático y su repercusión a nivel orgánico. Se utilizaron ratones macho de 3 meses E2F1-/-, E2F2-/- y sus controles que serán alimentados con dieta control o rica en grasa (HFD) durante 10 semanas. Se analizaron parámetros séricos en estado de alimento y tras 13 horas de ayuno. Se investigaron in vivo los flujos metabólicos hepáticos implicados en la disponibilidad de fosfolípidos, diglicéridos y triglicéridos (TG) tras administración de sustratos radiactivos.

Advanced Reaction Systems for Hydrogen Production

[EN] This PhD work started in March 2010 with the support of the University of the Basque Country (UPV/EHU) under the program named “Formación de Personal Investigador” at the Chemical and Environmental Engineering Department in the Faculty of Engineering of Bilbao. The major part of the Thesis work was carried out in the mentioned department, as a member of the Sustainable Process Engineering (SuPrEn) research group. In addition, this PhD Thesis includes the research work developed during a period of 6 months at the Institut für Mikrotechnik Mainz GmbH, IMM, in Germany. During the four years of the Thesis, conventional and microreactor systems were tested for several feedstocks renewable and non-renewable, gases and liquids through several reforming processes in order to produce hydrogen. For this purpose, new catalytic formulations which showed high activity, selectivity and stability were design. As a consequence, the PhD work performed allowed the publication of seven scientific articles in peer-reviewed journals. This PhD Thesis is divided into the following six chapters described below. The opportunity of this work is established on the basis of the transition period needed for moving from a petroleum based energy system to a renewable based new one. Consequently, the present global energy scenario was detailed in Chapter 1, and the role of hydrogen as a real alternative in the future energy system was justified based on several outlooks. Therefore, renewable and non-renewable hydrogen production routes were presented, explaining the corresponding benefits and drawbacks. Then, the raw materials used in this Thesis work were described and the most important issues regarding the processes and the characteristics of the catalytic formulations were explained. The introduction chapter finishes by introducing the concepts of decentralized production and process intensification with the use of microreactors. In addition, a small description of these innovative reaction systems and the benefits that entailed their use were also mentioned. In Chapter 2 the main objectives of this Thesis work are summarized. The development of advanced reaction systems for hydrogen rich mixtures production is the main objective. In addition, the use and comparison between two different reaction systems, (fixed bed reactor (FBR) and microreactor), the processing of renewable raw materials, the development of new, active, selective and stable catalytic formulations, and the optimization of the operating conditions were also established as additional partial objectives. Methane and natural gas (NG) steam reforming experimental results obtained when operated with microreactor and FBR systems are presented in Chapter 3. For these experiments nickel-based (Ni/Al2O3 and Ni/MgO) and noble metal-based (Pd/Al2O3 and Pt/Al2O3) catalysts were prepared by wet impregnation and their catalytic activity was measured at several temperatures, from 973 to 1073 K, different S/C ratios, from 1.0 to 2.0, and atmospheric pressure. The Weight Hourly Space Velocity (WHSV) was maintained constant in order to compare the catalytic activity in both reaction systems. The results obtained showed a better performance of the catalysts operating in microreactors. The Ni/MgO catalyst reached the highest hydrogen production yield at 1073 K and steam-to-carbon ratio (S/C) of 1.5 under Steam methane Reforming (SMR) conditions. In addition, this catalyst also showed good activity and stability under NG reforming at S/C=1.0 and 2.0. The Ni/Al2O3 catalyst also showed high activity and good stability and it was the catalyst reaching the highest methane conversion (72.9 %) and H2out/CH4in ratio (2.4) under SMR conditions at 1073 K and S/C=1.0. However, this catalyst suffered from deactivation when it was tested under NG reforming conditions. Regarding the activity measurements carried out with the noble metal-based catalysts in the microreactor systems, they suffered a very quick deactivation, probably because of the effects attributed to carbon deposition, which was detected by Scanning Electron Microscope (SEM). When the FBR was used no catalytic activity was measured with the catalysts under investigation, probably because they were operated at the same WHSV than the microreactors and these WHSVs were too high for FBR system. In Chapter 4 biogas reforming processes were studied. This chapter starts with an introduction explaining the properties of the biogas and the main production routes. Then, the experimental procedure carried out is detailed giving concrete information about the experimental set-up, defining the parameters measured, specifying the characteristics of the reactors used and describing the characterization techniques utilized. Each following section describes the results obtained from activity testing with the different catalysts prepared, which is subsequently summarized: Section 4.3: Biogas reforming processes using γ-Al2O3 based catalysts The activity results obtained by several Ni-based catalysts and a bimetallic Rh-Ni catalyst supported on magnesia or alumina modified with oxides like CeO2 and ZrO2 are presented in this section. In addition, an alumina-based commercial catalyst was tested in order to compare the activity results measured. Four different biogas reforming processes were studied using a FBR: dry reforming (DR), biogas steam reforming (BSR), biogas oxidative reforming (BOR) and tri-reforming (TR). For the BSR process different steam to carbon ratios (S/C) from 1.0 to 3.0, were tested. In the case of BOR process the oxygen-to-methane (O2/CH4) ratio was varied from 0.125 to 0.50. Finally, for TR processes different S/C ratios from 1.0 to 3.0, and O2/CH4 ratios of 0.25 and 0.50 were studied. Then, the catalysts which achieved high activity and stability were impregnated in a microreactor to explore the viability of process intensification. The operation with microreactors was carried out under the best experimental conditions measured in the FBR. In addition, the physicochemical characterization of the fresh and spent catalysts was carried out by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), N2 physisorption, H2 chemisorption, Temperature Programmed Reduction (TPR), SEM, X-ray Photoelectron Spectroscopy (XPS) and X-ray powder Diffraction (XRD). Operating with the FBR, conversions close to the ones predicted by thermodynamic calculations were obtained by most of the catalysts tested. The Rh-Ni/Ce-Al2O3 catalyst obtained the highest hydrogen production yield in DR. In BSR process, the Ni/Ce-Al2O3 catalyst achieved the best activity results operating at S/C=1.0. In the case of BOR process, the Ni/Ce-Zr-Al2O3 catalyst showed the highest reactants conversion values operating at O2/CH4=0.25. Finally, in the TR process the Rh-Ni/Ce-Al2O3 catalyst obtained the best results operating at S/C=1.0 and O2/CH4=0.25. Therefore, these three catalysts were selected to be coated onto microchannels in order to test its performance under BOR and TR processes conditions. Although the operation using microreactors was carried out under considerably higher WHSV, similar conversions and yields as the ones measured in FBR were measured. Furthermore, attending to other measurements like Turnover Frequency (TOF) and Hydrogen Productivity (PROD), the values calculated for the catalysts tested in microreactors were one order of magnitude higher. Thus, due to the low dispersion degree measured by H2-chemisorption, the Ni/Ce-Al2O3 catalyst reached the highest TOF and PROD values. Section 4.4: Biogas reforming processes using Zeolites L based catalysts In this section three type of L zeolites, with different morphology and size, were synthesized and used as catalyst support. Then, for each type of L zeolite three nickel monometallic and their homologous Rh-Ni bimetallic catalysts were prepared by the wetness impregnation method. These catalysts were tested using the FBR under DR process and different conditions of BSR (S/C ratio of 1.0 and 2.0), BOR (O2/CH4 ratio of 0.25 and 0.50) and TR processes (at S/C=1.0 and O2/CH4=0.25). The characterization of these catalysts was also carried out by using the same techniques mentioned in the previous section. Very high methane and carbon dioxide conversion values were measured for almost all the catalysts under investigation. The experimental results evidenced the better catalytic behavior of the bimetallic catalysts as compared to the monometallic ones. Comparing the catalysts behavior with regards to their morphology, for the BSR process the Disc catalysts were the most active ones at the lowest S/C ratio tested. On the contrary, the Cylindrical (30–60 nm) catalysts were more active under BOR conditions at O2/CH4=0.25 and TR processes. By the contrary, the Cylindrical (1–3 µm) catalysts showed the worst activity results for both processes. Section 4.5: Biogas reforming processes using Na+ and Cs+ doped Zeolites LTL based catalysts A method for the synthesis of Linde Type L (LTL) zeolite under microwave-assisted hydrothermal conditions and its behavior as a support for heterogeneously catalyzed hydrogen production is described in this section. Then, rhodium and nickel-based bimetallic catalysts were prepared in order to be tested by DR process and BOR process at O2/CH4=0.25. Moreover, the characterization of the catalysts under investigation was also carried out. Higher activities were achieved by the catalysts prepared from the non-doped zeolites, Rh-Ni/D and Rh-Ni/N, as compared to the ones supported on Na+ and Cs+ exchanged supports. However, the differences between them were not very significant. In addition, the Na+ and Cs+ incorporation affected mainly to the Disc catalysts. Comparing the results obtained by these catalysts with the ones studied in the section 4.4, in general worst results were achieved under DR conditions and almost the same results when operated under BOR conditions. In Chapter 5 the ethylene glycol (EG) as feed for syngas production by steam reforming (SR) and oxidative steam reforming (OSR) was studied by using microchannel reactors. The product composition was determined at a S/C of 4.0, reaction temperatures between 625°C and 725°C, atmospheric pressure and Volume Hourly Space Velocities (VHSV) between 100 and 300 NL/(gcath). This work was divided in two sections. The first one corresponds to the introduction of the main and most promising EG production routes. Then, the new experimental procedure is detailed and the information about the experimental set-up and the measured parameters is described. The characterization was carried out using the same techniques as for the previous chapter. Then, the next sections correspond to the catalytic activity and catalysts characterization results. Section 5.3: xRh-cm and xRh-np catalysts for ethylene glycol reforming Initially, catalysts with different rhodium loading, from 1.0 to 5.0 wt. %, and supported on α-Al2O3 were prepared by two different preparation methods (conventional impregnation and separate nanoparticle synthesis). Then, the catalysts were compared regarding their measured activity and selectivity, as well as the characterization results obtained before and after the activity tests carried out. The samples prepared by a conventional impregnation method showed generally higher activity compared to catalysts prepared from Rh nanoparticles. By-product formation of species such as acetaldehyde, ethane and ethylene was detected, regardless if oxygen was added to the feed or not. Among the catalysts tested, the 2.5Rh-cm catalyst was considered the best one. Section 5.4: 2.5Rh-cm catalyst support modification with CeO2 and La2O3 In this part of the Chapter 5, the catalyst showing the best performance in the previous section, the 2.5Rh-Al2O3 catalyst, was selected in order to be improved. Therefore, new Rh based catalysts were designed using α-Al2O3 and being modified this support with different contents of CeO2 or La2O3 oxides. All the catalysts containing additives showed complete conversion and selectivities close to the equilibrium in both SR and OSR processes. In addition, for these catalysts the concentrations measured for the C2H4, CH4, CH3CHO and C2H6 by-products were very low. Finally, the 2.5Rh-20Ce catalyst was selected according to its catalytic activity and characterization results in order to run a stability test, which lasted more than 115 hours under stable operation. The last chapter, Chapter 6, summarizes the main conclusions achieved throughout this Thesis work. Although very high reactant conversions and rich hydrogen mixtures were obtained using a fixed bed reaction system, the use of microreactors improves the key issues, heat and mass transfer limitations, through which the reforming reactions are intensified. Therefore, they seem to be a very interesting and promising alternative for process intensification and decentralized production for remote application.

Effects of global change on the functioning of Mediterranean Rivers

138 p.

Efecto antitumoral de la terfenadina, antagonista del receptor H1 de la histamina, mediado por el complejo I mitocondrial

180 p.

Evaluation of a programme to improve emotional intelligence during adolescence

348 p.

Programa de apoyo psicológico a inmigrantes: estudio de casos

419 p.