Size and shape of supported zirconia nanoparticles determined by x-ray photoelectron spectroscopy

6 pages, 7 figures, 1 table.-- PACS: 68.55.Ac; 68.55.Jk; 79.60.DpThe initial stages of growth of zirconia nanoparticles deposited on SiO2, Y2O3, and CeO2 substrates have been studied by the x-ray photoelectron spectroscopy peak shape analysis. ZrO2 was deposited by plasma decomposition of a volatile Zr(OtBu)4 precursor. The electronic interactions at each particular interface formed have been followed by means of the modified Auger parameter of the deposited Zr cations. They were quantified by means of Wagner plots and the chemical state vectors of the systems. The observed changes in these local electronic probes as the amount of deposit was increased have been correlated to the particular ZrO2 nanostructures identified on each substrate considered. A Volmer-Weber (islands) growth mechanism has been found for all the substrates considered. Moreover, clear indications have been found of a columnar growth for the case of ZrO2 deposited on SiO2.We thank the Spanish Ministry of Science and Education (MAT2004-01558) for financial support.Peer reviewe

Plasma-enhanced chemical vapor deposition of SiO2 from a Si(CH3)3Cl precursor and mixtures Ar/O2 as plasma gas

Silicon dioxide thin films have been prepared at room temperature by remote plasma-enhanced chemical vapor deposition in a downstream reactor by using Si(CH3)3Cl as a volatile precursor and a microwave electron cyclotron resonance external source. Experiments are done at constant pressure by changing the relative amount of Ar species R in the plasma gas. The aim was to obtain thin films with low density and, therefore, low refractive index. Characterization of the species of the plasma is carried out by optical emission spectroscopy. The changes of the plasma conditions are correlated with the growing rate and microstructure of the films, the latter determined by atomic force microscopy and infrared spectroscopy. It is found that the growing rate of the films decreases and their roughness increases as R increases. The optical properties of SiO2 thin films are analyzed by optical ellipsometry. A decrease in the refractive index is found for the films grown with high values of R. The possible routes for activation of the precursor and the formation of the SiO2 thin films are discussed.Ministerio de Ciencia y Tecnología MAT2001-2820European Union ERK6-CT-1999-0001

Haemophilus parasuis

The expression of chemokines (CCL-2 and CXCL-8) and cytokines (IL-1α, IL-1β, IL-6, TNF-α, and IL-10) was evaluated by RT-qPCR in colostrum-deprived pigs vaccinated and challenged with Haemophilus parasuis serovar 5. Two vaccines containing native proteins with affinity to porcine transferrin (NPAPTim and NPAPTit) were tested, along with two control groups: one inoculated with PBS instead of antigen (challenge group (CHG)), and another one nonimmunized and noninfected (blank group). The use of NPAPTim and NPAPTit resulted in complete protection against H. parasuis (no clinical signs and/or lesions), and both vaccines were capable of avoiding the expression of the proinflammatory molecules to levels similar to physiological values in blank group. However, overexpression of all proinflammatory molecules was observed in CHG group, mainly in the target infection tissues (brain, lungs, and spleen). High expression of CCL-2, CXCL-8, IL-1α, IL-1β, and IL-6 can be considered one of the characteristics of H. parasuis infection by serovar 5

Effect of surface roughness and sterilization on bacterial adherence to ultra-high molecular weight polyethylene

AbstractSterilization with ethylene oxide (EO) and gas plasma (GP) are well-known methods applied to ultra-high molecular weight polyethylene (UHMWPE) surfaces in the belief that they prevent major material changes caused by gamma irradiation. However, the influence of these surface sterilization methods on bacterial adherence to UHMWPE is unknown. UHMWPE samples with various degrees of roughness (0.3, 0.8 and 2.0 µm) were sterilized with either GP or EO. The variations in hydrophobicity, surface free energy and surface functional groups were investigated before and after sterilization. Sterilized samples were incubated with either Staphylococcus aureus or Staphylococcus epidermidis in order to study bacterial adherence to these materials. Fewer bacteria adhered to UHMWPE after sterilization with EO than after sterilization with GP, especially to the smoothest surfaces. No changes in chemical composition of the UHMWPE surface due to sterilization were observed using X-ray photoemission spectroscopy analysis. The decreased bacterial adherence to UHMWPE found at the smoothest surfaces after sterilization with EO was not directly related to changes in chemical composition. Increased bacterial adherence to rougher surfaces was associated with increased polar surface energy of EO-sterilized surfaces

Assessment by immunoproteomic study of the immune response developed by different subunit vaccines against glässer's disease

Comunicaciones a congreso

Age protects from harmful effects produced by chronic intermittent hypoxia

Producción CientíficaObstructive sleep apnoea (OSA) affects an estimated 3–7% of the adult population, the frequency doubling at ages >60–65 years. As it evolves, OSA becomes frequently associated with cardiovascular, metabolic and neuropsychiatric pathologies defining OSA syndrome (OSAS). Exposing experimental animals to chronic intermittent hypoxia (CIH) can be used as a model of the recurrent hypoxic and O2 desaturation patterns observed in OSA patients. CIH is an important OSA event triggering associated pathologies; CIH induces carotid body (CB)-driven exaggerated sympathetic tone and overproduction of reactive oxygen species, related to the pathogenic mechanisms of associated pathologies observed in OSAS. Aiming to discover why OSAS is clinically less conspicuous in aged patients, the present study compares CIH effects in young (3–4 months) and aged (22–24 months) rats. To define potential distinctive patterns of these pathogenic mechanisms, mean arterial blood pressure as the final CIH outcome was measured. In young rats, CIH augmented CB sensory responses to hypoxia, decreased hypoxic ventilation and augmented sympathetic activity (plasma catecholamine levels and renal artery content and synthesis rate). An increased brainstem integration of CB sensory input as a trigger of sympathetic activity is suggested. CIH also caused an oxidative status decreasing aconitase/fumarase ratio and superoxide dismutase activity. In aged animals, CIH minimally affected CB responses, ventilation and sympathetic-related parameters leaving redox status unaltered. In young animals, CIH caused hypertension and in aged animals, whose baseline blood pressure was augmented, CIH did not augment it further. Plausible mechanisms of the differences and potential significance of these findings for the diagnosis and therapy of OSAS are discussed.Ministerio de Ciencia, Innovación y Universidades (grant BFU2012-37459)Instituto de Salud Carlos III (grant CIBER CB06/06/0050)Portuguese Foundation for Science and Technology (grant EXP/NEU-SCC/2813/2013

Control of parameters of a porcine artificial insemination center

El uso de la inseminación artificial en España ha experimentado un gran crecimiento en estos últimos años. Conjuntamente ha crecido el número de centros de inseminación artificial (CIA) independientes o adosados a las explotaciones. Para rentabilizar al máximo dichos centros, se hace imprescindible una buena gestión, para el control de las condiciones ambientales donde se alojan los verracos, el estatus sanitario de los mismos, así como un seguimiento de la producción y calidad del semen. Con el fin de obtener dosis seminales con calidad y concentración adecuadas se pueden aplicar factores de corrección, en base a los diferentes parámetros espermáticos posibles de evaluar en un CIA, y así obtener un número adecuado de dosis inseminantes de cada verraco Así mismo, se hace necesario -realizar la programación del trabajo diario y maximizar la rentabilidad, controlando el ritmo de extracción de semen y optimizando el balance de dosis producidas, vendidas y desechadas. Cabe remarcar que la buena gestión de un CIA se facilita con el uso de programas informáticos.Artificial insemination has greatly developed in Spain in the past years. At the same time the number of artificial insemination centres (MC) has increased within the farms and independently. Good management is essential to render these centres profitable. Important factors are: environmental control, housing of the animals, health status and production and quality of semen. In order to get semen of high quality, correction factors based on the parameters which can be applied to semen evaluation in an AIC may be used. It is advisable tu establish a daily routine tu maximize rentability, control the collection rate and tu optimize the balance between semen obtained sold and wasted. Informatization of the AIC makes a good management easier.Facultad de Ciencias Veterinaria

Control of parameters of a porcine artificial insemination center

El uso de la inseminación artificial en España ha experimentado un gran crecimiento en estos últimos años. Conjuntamente ha crecido el número de centros de inseminación artificial (CIA) independientes o adosados a las explotaciones. Para rentabilizar al máximo dichos centros, se hace imprescindible una buena gestión, para el control de las condiciones ambientales donde se alojan los verracos, el estatus sanitario de los mismos, así como un seguimiento de la producción y calidad del semen. Con el fin de obtener dosis seminales con calidad y concentración adecuadas se pueden aplicar factores de corrección, en base a los diferentes parámetros espermáticos posibles de evaluar en un CIA, y así obtener un número adecuado de dosis inseminantes de cada verraco Así mismo, se hace necesario -realizar la programación del trabajo diario y maximizar la rentabilidad, controlando el ritmo de extracción de semen y optimizando el balance de dosis producidas, vendidas y desechadas. Cabe remarcar que la buena gestión de un CIA se facilita con el uso de programas informáticos.Artificial insemination has greatly developed in Spain in the past years. At the same time the number of artificial insemination centres (MC) has increased within the farms and independently. Good management is essential to render these centres profitable. Important factors are: environmental control, housing of the animals, health status and production and quality of semen. In order to get semen of high quality, correction factors based on the parameters which can be applied to semen evaluation in an AIC may be used. It is advisable tu establish a daily routine tu maximize rentability, control the collection rate and tu optimize the balance between semen obtained sold and wasted. Informatization of the AIC makes a good management easier.Facultad de Ciencias Veterinaria

Recommendations for reporting equivalent black carbon (eBC) mass concentrations based on long-term pan-European in-situ observations

A reliable determination of equivalent black carbon (eBC) mass concentrations derived from filter absorption photometers (FAPs) measurements depends on the appropriate quantification of the mass absorption cross-section (MAC) for converting the absorption coefficient (babs) to eBC. This study investigates the spatial–temporal variability of the MAC obtained from simultaneous elemental carbon (EC) and babs measurements performed at 22 sites. We compared different methodologies for retrieving eBC integrating different options for calculating MAC including: locally derived, median value calculated from 22 sites, and site-specific rolling MAC. The eBC concentrations that underwent correction using these methods were identified as LeBC (local MAC), MeBC (median MAC), and ReBC (Rolling MAC) respectively. Pronounced differences (up to more than 50 %) were observed between eBC as directly provided by FAPs (NeBC; Nominal instrumental MAC) and ReBC due to the differences observed between the experimental and nominal MAC values. The median MAC was 7.8 ± 3.4 m2 g-1 from 12 aethalometers at 880 nm, and 10.6 ± 4.7 m2 g-1 from 10 MAAPs at 637 nm. The experimental MAC showed significant site and seasonal dependencies, with heterogeneous patterns between summer and winter in different regions. In addition, long-term trend analysis revealed statistically significant (s.s.) decreasing trends in EC. Interestingly, we showed that the corresponding corrected eBC trends are not independent of the way eBC is calculated due to the variability of MAC. NeBC and EC decreasing trends were consistent at sites with no significant trend in experimental MAC. Conversely, where MAC showed s.s. trend, the NeBC and EC trends were not consistent while ReBC concentration followed the same pattern as EC. These results underscore the importance of accounting for MAC variations when deriving eBC measurements from FAPs and emphasize the necessity of incorporating EC observations to constrain the uncertainty associated with eBC.</p