4,793 research outputs found

    First tests of the applicability of γ\gamma-ray imaging for background discrimination in time-of-flight neutron capture measurements

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    In this work we explore for the first time the applicability of using γ\gamma-ray imaging in neutron capture measurements to identify and suppress spatially localized background. For this aim, a pinhole gamma camera is assembled, tested and characterized in terms of energy and spatial performance. It consists of a monolithic CeBr3_3 scintillating crystal coupled to a position-sensitive photomultiplier and readout through an integrated circuit AMIC2GR. The pinhole collimator is a massive carven block of lead. A series of dedicated measurements with calibrated sources and with a neutron beam incident on a 197^{197}Au sample have been carried out at n_TOF, achieving an enhancement of a factor of two in the signal-to-background ratio when selecting only those events coming from the direction of the sample.Comment: Preprint submitted to Nucl. Instr. and Meth.

    Using the Social-Local-Mobile App for Smoking Cessation in the SmokeFreeBrain Project: Protocol for a Randomized Controlled Trial

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    Background: Smoking is considered the main cause of preventable illness and early deaths worldwide. The treatment usually prescribed to people who wish to quit smoking is a multidisciplinary intervention, combining both psychological advice and pharmacological therapy, since the application of both strategies significantly increases the chance of success in a quit attempt. Objective: We present a study protocol of a 12-month randomized open-label parallel-group trial whose primary objective is to analyze the efficacy and efficiency of usual psychopharmacological therapy plus the Social-Local-Mobile app (intervention group) applied to the smoking cessation process compared with usual psychopharmacological therapy alone (control group). Methods: The target population consists of adult smokers (both male and female) attending the Smoking Cessation Unit at Virgen del Rocío University Hospital, Seville, Spain. Social-Local-Mobile is an innovative intervention based on mobile technologies and their capacity to trigger behavioral changes. The app is a complement to pharmacological therapies to quit smoking by providing personalized motivational messages, physical activity monitoring, lifestyle advice, and distractions (minigames) to help overcome cravings. Usual pharmacological therapy consists of bupropion (Zyntabac 150 mg) or varenicline (Champix 0.5 mg or 1 mg). The main outcomes will be (1) the smoking abstinence rate at 1 year measured by means of exhaled carbon monoxide and urinary cotinine tests, and (2) the result of the cost-effectiveness analysis, which will be expressed in terms of an incremental cost-effectiveness ratio. Secondary outcome measures will be (1) analysis of the safety of pharmacological therapy, (2) analysis of the health-related quality of life of patients, and (3) monitoring of healthy lifestyle and physical exercise habits. Results: Of 548 patients identified using the hospital’s electronic records system, we excluded 308 patients: 188 declined to participate and 120 did not meet the inclusion criteria. A total of 240 patients were enrolled: the control group (n=120) will receive usual psychopharmacological therapy, while the intervention group (n=120) will receive usual psychopharmacological therapy plus the So-Lo-Mo app. The project was approved for funding in June 2015. Enrollment started in October 2016 and was completed in October 2017. Data gathering was completed in November 2018, and data analysis is under way. The first results are expected to be submitted for publication in early 2019. Conclusions: Social networks and mobile technologies influence our daily lives and, therefore, may influence our smoking habits as well. As part of the SmokeFreeBrain H2020 European Commission project, this study aims at elucidating the potential role of these technologies when used as an extra aid to quit smoking

    Soil pH effects on the Toxicity of zinc oxide nanoparticles to soil bacterial communities.

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    The environmental levels of ZnO nanoparticles (nZnO) are increasing continually given the widespread and expanding applications of this material. Soil pH appears to be one of the key factors affecting the behavior and toxicity of metal nanoparticles in soi

    Assessing Single Upconverting Nanoparticle Luminescence by Optical Tweezers

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    We report on stable, long-term immobilization and localization of a single colloidal Er3+/Yb3+ codoped upconverting fluorescent nanoparticle (UCNP) by optical trapping with a single infrared laser beam. Contrary to expectations, the single UCNP emission differs from that generated by an assembly of UCNPs. The experimental data reveal that the differences can be explained in terms of modulations caused by radiation-trapping, a phenomenon not considered before but that this work reveals to be of great relevanceThis work was supported by the Spanish Ministerio de Educación y Ciencia (MAT2010–16161 and MAT2013–47395-C4–1-R). P.H.G. thanks the Spanish Ministerio de Economía y Competitividad (MINECO) for the Juan de la Cierva program. P.R.S thanks the Spanish Ministerio de Economía y Competitividad (MINECO) for the “Promoción 14 del talento y su Empleabilidad en I+D+i” statal program. Fondazione Cariverona (Verona, Italy) is gratefully acknowledged for financial support in the frame of the project “Verona Nanomedicine Initiative

    Effects of acepromazine on capture stress in roe deer (Capreolus capreolus)

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    The aim of this study was to evaluate effect of a short-acting neuroleptic (acepromazine) on capture stress response in roe deer (Capreolus capreolus). Sixteen roe deer were captured by drive-nets in the winters of 1998, 1999, and 2001. Roe deer were divided into two groups: animals in the treatment group received an intramuscular injection of acepromazine (0.093 mg/kg +/- 0.003 SEM; n = 8) while animals in the control group (n = 8) did not receive tranquilizer. Heart rate and body temperature, as well as hematologic and biochemical indicators of stress, were used to evaluate effect of the neuroleptic over 3 hr. Heart rate decreased over time after capture in both groups (P < 0.05), but stabilized sooner in the treated roe deer (75 min after capture) than in the controls (105 min after capture). Body temperature decreased over 45 min and then stabilized in both groups (P < 0.05). Comparisons of blood parameters revealed significantly lower red blood cell count (RBC), lymphocyte count, hemoglobin concentration, packed cell volume (PCV), and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase (CK), and lactate dehydrogenase (LDH) activities in tranquilized animals compared with controls (at least P < 0.05). A reduction in PCV, lymphocyte count, and serum cortisol concentrations (at least P < 0.05) and an increase in serum creatinine levels (P < 0.05) were recorded over time in control animals, while a reduction in RBC and hemoglobin concentration (at least P < 0.05) and an increase in serum urea concentrations (P < 0.05) over time were observed in the treated group. Finally, a decrease in serum lactate and potassium levels and an increase in CK, AST, ALT, and LDH activities were recorded over time in both groups. Results obtained showed the suitability of using acepromazine in capture operations in order to reduce stress response and prevent its adverse effects in roe deer. The beneficial effect was not only due to the sedative effect of acepromazine, but also to peripheral vasodilatation

    Situational analysis of the subjective well-being of university software developers in Puebla

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    Integral well-being is vital for the optimal functioning of people. The requirements for a software developer in the performance of their professional activity are varied and complex. These requirements range from working in multidisciplinary and multilingual teams, going through the challenge of technological advances of the discipline to commit to quality and innovation. To face these demands, it is essential that the developers have an optimal functioning, where the experience emotional and satisfaction with life play an important role. The objective of this article is to analyze the subjective well-being of university software developers in Puebla. The research is a quantitative cross-correlation study to identify statistically significant relationships between the different welfare variables. The study involved 47 university software developers from the city of Puebla. We use Pearson's multivariate correlation to validate the instruments and find relationships between variables, and Chi-squared statistics to calculate the dependency between them. The results reveal that the university software developers experience with higher incidence and intensity, the positive affections over the negatives. The affective balance (Net Affect), calculated as the difference of the weighted averages by duration between positive affective states and negative, was positive (mean = 1.31). "Concentrated" is the positive affective state with the highest incidence and with the highest reported intensity. "Tired" is the most experienced negative affect and highest in intensity. Developers spend 40% of their time experiencing negative affective states (U-index) and are moderately satisfied with their lives in general

    Dexmedetomidine Restores Autophagic Flux, Modulates Associated microRNAs and the Cholinergic Anti-inflammatory Pathway upon LPS-Treatment in Rats

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    Infections and perioperative stress can lead to neuroinflammation, which in turn is linked to cognitive impairments such as postoperative delirium or postoperative cognitive dysfunctions. The alpha 2-adrenoceptor agonist dexmedetomidine (DEX) prevents cognitive impairments and has organo-protective and anti-inflammatory properties. Macroautophagy (autophagy) regulates many biological processes, but its role in DEX-mediated anti-inflammation and the underlying mechanism of DEX remains largely unclear. We were interested how a pretreatment with DEX protects against lipopolysaccharide (LPS)-induced inflammation in adult male Wistar rats. We used Western blot and activity assays to study how DEX modulated autophagy- and apoptosis-associated proteins as well as molecules of the cholinergic anti-inflammatory pathway, and qPCR to analyse the expression of autophagy and inflammation-associated microRNAs (miRNA) in the spleen, cortex and hippocampus at different time points (6 h, 24 h, 7 d). We showed that a DEX pretreatment prevents LPS-induced impairments in autophagic flux and attenuates the LPS-induced increase in the apoptosis-associated protein cleaved poly(ADP-ribose)-polymerase (PARP) in the spleen. Both, DEX and LPS altered miRNA expression and molecules of the cholinergic anti-inflammatory pathway in the spleen and brain. While only a certain set of miRNAs was up- and/or downregulated by LPS in each tissue, which was prevented or attenuated by a DEX pretreatment in the spleen and hippocampus, all miRNAs were up- and/or downregulated by DEX itself - independent of whether or not they were altered by LPS. Our results indicate that the organo-protective effect of DEX may be mediated by autophagy, possibly by acting on associated miRNAs, and the cholinergic anti-inflammatory pathway

    Pressure dependence of Raman modes in double wall carbon nanotubes filled with α-Fe.

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    The preparation of highly anisotropic one-dimensional (1D) structures confined into carbon nanotubes (CNTs) in general is a key objective in CNTs research. In this work, the capillary effect was used to fill double wall carbon nanotubes with iron. The samples are characterized by Mössbauer and Raman spectroscopy, transmission electron microscopy, scanning area electron diffraction, and magnetization. In order to investigate their structural stability and compare it with that of single wall carbon nanotubes (SWNTs), elucidating the differences induced by the inner-outer tube interaction, unpolarized Raman spectra of tangential modes of double wall carbon nanotubes (DWNTs) filled with 1D nanocrystallin α-Fe excited with 514 nm were studied at room temperature and elevated pressure. Up to 16 GPa we find a pressure coefficient for the internal tube of 4.3 cm−1 GPa−1 and for the external tube of 5.5 cm−1 GPa−1. In addition, the tangential band of the external and internal tubes broadens and decreases in amplitude. All findings lead to the conclusion that the outer tube acts as a protection shield for the inner tubes (at least up 16 GPa). Structural phase transitions were not observed in this range of pressure

    La red MARHIS. Una alianza estratégica para la ingeniería y las EERR marinas en España

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    MARHIS agradece la financiación recibida por MINECO a través de las Acciones de dinamización “Redes de Excelencia” Convocatoria 2015

    Análisis de la línea base de metales pesados en zonas agrícolas de Colombia

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    Los recursos naturales ofertan una serie de bienes y servicios necesarios para el desarrollo económico y el bienestar social del hombre. El recurso suelo, oferta servicios ecosistémicos fundamentales entre las que se resaltan: el soporte para la producción de alimentos y su importancia en la mitigación de los efectos del cambio climático debido a la dinámica del carbono. Sin embargo, actividades antrópicas como la densificación urbana, la industrialización y principalmente la agrícultura aportan elementos como metales pesados y estos son responsables de la degradación del suelo en algunas regiones del mundo. Naturalmente los suelos en su base geoquímica tienen metales pesados y en la mayoría de las regiones éstas concentraciones no representan riesgo ambiental, aunque en zonas con mayor presión antrópica las concentraciones han aumentado. En este sentido, el propósito de la presente investigación fue recopilar los estudios de metales pesados desarrollados en sistemas de producción agrícola en Colombia, y con esto establecer una línea base que permita identificar necesidades futuras de investigación en esta temática. Entre los resultados encontrados, se identificó que los metales pesados estudiados en el país son Cd>Pb>Hg>Cr>Ni>Cu=Zn=As>Mn>Fe, destacándose el Cd, Pb y Hg metales de mayor toxicidad. Sin embargo, en Colombia la producción científica es relativamente baja: apenas en las bases de datos se localizaron 31 artículos relacionados con metales pesados en la producción agrícola (suelo, cultivos o insumo). Asimismo, estos trabajos se localizaron en la región central del país, evidenciando que en regiones como la Orinoquia, considerada como la frontera y despensa agrícola del país, únicamente se reportaron tres estudios publicados en los últimos años. Finalmente con esto se resalta la importancia de generar investigaciones en áreas productoras de alimentos y además de generar valores de referencia para estos elementos en los suelos colombianos que permitan evaluar posible contaminación.Trabajo publicado en Acta Bioquímica Clínica Latinoamericana; no. 52, supl. 2, parte I, diciembre de 2018.Universidad Nacional de La Plat
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