4,190 research outputs found

    Probing the catalytic activity of sulfate-derived Pristine and post-treated porous TiO2(101) anatase mesocrystals by the oxidative desulfurization of dibenzothiophenes

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    Mesocrystals (basically nanostructures showing alignment of nanocrystals well beyond crystal size) are attracting considerable attention for modeling and optimization of functionalities. However, for surface-driven applications (heterogeneous catalysis), only those mesocrystals with excellent textural properties are expected to fulfill their potential. This is especially true for oxidative desulfuration of dibenzothiophenes (hard to desulfurize organosulfur compounds found in fossil fuels). Here, we probe the catalytic activity of anatases for the oxidative desulfuration of dibenzothiophenes under atmospheric pressure and mild temperatures. Specifically, for this study, we have taken advantage of the high stability of the (101) anatase surface to obtain a variety of uniform colloidal mesocrystals (approximately 50 nm) with adequate orientational order and good textural properties (pores around 3-4 nm and surface areas around 200 m2/g). Ultimately, this stability has allowed us to compare the catalytic activity of anatases that expose a high number of aligned single crystal-like surfaces while differing in controllable surface characteristics. Thus, we have established that the type of tetrahedral coordination observed in these anatase mesocrystals is not essential for oxidative desulfuration and that both elimination of sulfates and good textural properties significantly improve the catalytic activity. Furthermore, the most active mesocrystals have been used to model the catalytic reaction in three-(oil-solvent-catalyst) and two-phase (solvent-catalyst) systems. Thus, we have been able to observe that the transfer of DBT from the oil to the solvent phase partially limits the oxidative process and to estimate an apparent activation energy for the oxidative desulfuration reaction of approximately 40 kJ/mol in the two-phase system to avoid mass transfer limitations. Our results clearly establish that (101) anatase mesocrystals with excellent textural properties show adequate stability to withstand several post-treatments without losing their initial mesocrystalline character and therefore could serve as models for catalytic processes different from the one studied here.Fil: Rivoira, Lorena Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; ArgentinaFil: Martinez, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; ArgentinaFil: Falcon, Horacio. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Beltramone, Andrea Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; ArgentinaFil: Campos-Martin, Jose M.. Consejo Superior de Investigaciones Científicas; EspañaFil: García Fierro, José Luis. Instituto de Catalisis y Petroleoquimica-csic; EspañaFil: Tartaj, Pedro. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; Españ

    Germinal Matrix-Intraventricular Hemorrhage of the Preterm Newborn and Preclinical Models: Inflammatory Considerations

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    The germinal matrix-intraventricular hemorrhage (GM-IVH) is one of the most important complications of the preterm newborn. Since these children are born at a critical time in brain development, they can develop short and long term neurological, sensory, cognitive and motor disabilities depending on the severity of the GM-IVH. In addition, hemorrhage triggers a microglia-mediated inflammatory response that damages the tissue adjacent to the injury. Nevertheless, a neuroprotective and neuroreparative role of the microglia has also been described, suggesting that neonatal microglia may have unique functions. While the implication of the inflammatory process in GM-IVH is well established, the difficulty to access a very delicate population has lead to the development of animal models that resemble the pathological features of GM-IVH. Genetically modified models and lesions induced by local administration of glycerol, collagenase or blood have been used to study associated inflammatory mechanisms as well as therapeutic targets. In the present study we review the GM-IVH complications, with special interest in inflammatory response and the role of microglia, both in patients and animal models, and we analyze specific proteins and cytokines that are currently under study as feasible predictors of GM-IVH evolution and prognosis

    Considerations on the low-pressure exhaust gas recirculation system control in turbocharged diesel engines

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    Although high-pressure exhaust gas recirculation has been commonly used in turbocharged diesel engines for controlling the NOx formation, recent advances in after-treatment and material technology make possible using a low-pressure architecture, which recirculates the exhaust gas upstream the compressor. This brief article presents a basic study of control aspect related to the low-pressure architecture, emphasising the similarities and differences with the highpressure system. Data from experimental tests with both configurations and from a one-dimensional wave action model simulations are combined for the analysis of the input–output paring, linearity and the transient performance of both systems.This research has been partially financed by the Spanish Ministerio de Economia y Competitividad, through project IPT-370000-2010-022 'Investigacion y desarrollo de tecnologias de EGR adaptadas a las nuevas arquitecturas y requerimientos de refrigeracion en motores diesel sobrealimentados para automocion (HIREFIRE)'.Lujan Martinez, JM.; Guardiola García, C.; Plá Moreno, B.; Cabrera López, P. (2014). Considerations on the low-pressure exhaust gas recirculation system control in turbocharged diesel engines. International Journal of Engine Research. 15(2):250-260. https://doi.org/10.1177/1468087413485209S25026015

    Spatial variation of the vegetative roughness in Mediterranean torrential streams affected by check dams

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    This is an Accepted Manuscript of an article published in Hydrological Sciences Journal on 2018, available online: http://www.tandfonline.com/10.1080/02626667.2017.1414384[EN] This study focuses on the spatial variations in vegetative roughness associated with morphological channel adjustments due to the presence of check dams in Mediterranean torrential streams. Manning's n values were estimated using methods established by previous studies of submerged and non-submerged vegetation in laboratory flume experiments and field work. The results showed a linear decrease in shrub density and rate of variation of the roughness coefficient versus degree of submergence with increasing distance upstream from the check dam, while downstream, the filling of the check dam and the bed incision had the most influence. A regression analysis was applied by fitting the data to different models: relationships between Manning's n and the flow velocity were found to be of the power type for shrubs in all upstream sections, while relationships of flow velocity versus hydraulic radius in the sections closest to check dams showed a good fit to second-order polynomial equations.This work was supported by project PI/13 (Hydrological and geomorphological response to the fluvial torrential systems affected by forestry-hydrological restoration works in semiarid catchments in southeast of Spain), from the Euromediterranean Institute of Hydrotechnics, European Council, and the Autonomous Community of Murcia, Spain.Conesa-García, C.; Sánchez-Tudela, JL.; Pérez-Cutillas, P.; Martinez-Capel, F. (2018). Spatial variation of the vegetative roughness in Mediterranean torrential streams affected by check dams. Hydrological Sciences Journal. 63(1):114-135. doi:10.1080/02626667.2017.1414384S11413563

    Fomento de la empleabilidad y el emprendimiento entre los alumnos de Grado en Geología

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    En la actualidad, el acceso al mercado laboral constituye un reto importante para un buen número de titulados universitarios. Esto se hace especialmente patente en aquellos sectores que, como la obra pública, el medio ambiente, la docencia o la investigación, han resultado fuertemente afectados por la crisis económica. Es el caso de los egresados del Grado en Geología, un colectivo que tradicionalmente encontraba acomodo profesional en algunos de estos campos y que se ha visto sumido en una situación de baja empleabilidad en España a lo largo de los últimos años. Esto ha redundado en que muchos de los geólogos de reciente titulación se han visto forzados a emigrar al extranjero. En tiempos recientes se ha observado una incipiente recuperación del mercado laboral nacional, lo que se viene traduciendo en más oportunidades de empleo para los geólogos. Sin embargo, entre los titulados a menudo se observa la ausencia de determinadas destrezas que resultan importantes a la hora de buscar trabajo, así como una cierta desorientación ante la realidad del mercado laboral. Este proyecto tiene por objeto contribuir a subsanar dichas carencias, fomentando con ello la empleabilidad de los egresados.Depto. de Mineralogía y PetrologíaDepto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasFALSEsubmitte

    Evaluation of Bayesian Networks in Participatory Water Resources Management, Upper Guadiana Basin, Spain

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    Stakeholder participation is becoming increasingly important in water resources management. In participatory processes, stakeholders contribute by putting forward their own perspective, and they benefit by enhancing their understanding of the factors involved in decision making. A diversity of modeling tools can be used to facilitate participatory processes. Bayesian networks are well suited to this task for a variety of reasons, including their ability to structure discussions and visual appeal. This research focuses on developing and testing a set of evaluation criteria for public participation. The advantages and limitations of these criteria are discussed in the light of a specific participatory modeling initiative. Modeling work was conducted in the Upper Guadiana Basin in central Spain, where uncontrolled groundwater extraction is responsible for wetland degradation and conflicts between farmers, water authorities, and environmentalists. Finding adequate solutions to the problem is urgent because the implementation of the EU Water Framework Directive requires all aquatic ecosystems to be in a “good ecological state” within a relatively short time frame. Stakeholder evaluation highlights the potential of Bayesian networks to support public participation processes

    Simulation of retrospective morphological channel adjustments using high-resolution differential digital elevation models versus predicted sediment delivery and stream power variations

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    [EN] This work proposes a methodological approach applied to ephemeral gravel-bed streams to verify the change in the magnitude and frequency of hydrological events affecting the morphological dynamics and sediment budget in this type of channel. For the case study, the Azohia Rambla, located in southeastern Spain, was chosen, emphasizing the research on two reference riverbed sections (RCRs): an upper one, with a predominance of erosion, and a middle one, where processes of incision, transport, and deposition were involved. First, this approach focuses on relationships between peak discharges and sediment budgets during the period 2018-2022. For this purpose, water level measurements from pressure sensors, a One-Dimensional Hydrodynamic model, and findings from comparative analyses of high-resolution differential digital elevation models (HRDEM of Difference-HRDoD) based on SfM-MVS and LiDAR datasets were used. In a second phase, the GeoWEPP model was applied to the period 1996-2022 in order to simulate runoff and sediment yield at the event scale for the watersheds draining into both RCRs. During the calibration phase, a sensitivity analysis was carried out to detect the most influential parameters in the model and confirm its capacity to simulate peak flow and sediment delivery in the area described above. Values of NS (Nash-Sutcliffe efficiency) and PBIAS (percent bias) equal to 0.86 and 7.81%, respectively, were found in the calibration period, while these indices were 0.81 and -4.1% in the validation period. Finally, different event class patterns (ECPs) were established for the monitoring period (2018-2022), according to flow stage and morphological channel adjustments (overtopping, bankfull and sub-bankfull, and half-sub-bankfull), and then retrospectively extrapolated to stages of the prior simulated period (1996-2018) from their typical sequences (PECPs). The results revealed a significant increase in the number of events and PECPs leading to lower bed incision rates and higher vertical accretion, which denotes a progressive increase in bed armoring and bank erosion processes.This research was funded by ERDF/Spanish Ministry of Science, Innovation and Universities-State Research Agency (AEI)/Project CGL2017-84625-C2-1-R. State Program for Research, Develop-ment and Innovation focused on the Challenges of SocietyConesa-García, C.; Martínez-Salvador, A.; Puig-Mengual, C.; Martinez-Capel, F.; Pérez-Cutillas, P. (2023). Simulation of retrospective morphological channel adjustments using high-resolution differential digital elevation models versus predicted sediment delivery and stream power variations. Water. 15(15):1-35. https://doi.org/10.3390/w15152697135151

    AMELIE: Authoring Multimedia-Enhanced Learning Interactive Environment for e-Health Contents

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    This paper presents the AMELIE Authoring Tool for e-health applications. AMELIE provides the means for creating video-based contents with a focus on e-learning and telerehabilitation processes. The main core of AMELIE lies in the efficient exploitation of raw multimedia resources, which may be already available at clinical centers or recorded ad hoc for learning purposes by health professionals. Three real use cases scenarios involving different target users are presented: (1) cognitive skills? training of surgeons in minimally invasive surgery (medical professionals), (2) training of informal carers for elderly home assistance and (3) cognitive rehabilitation of patients with acquired brain injury. Preliminary validation in the field of surgery hints at the potential of AMELIE; and its versatility in different medical applications is patent from the use cases described. Regardless, new validation studies are planned in the three main application areas identified in this work

    Empagliflozin reduces vascular damage and cognitive impairment in a mixed murine model of Alzheimer's disease and type 2 diabetes

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    Background Both Alzheimer's disease (AD) and type 2 diabetes (T2D) share common pathological features including inflammation, insulin signaling alterations, or vascular damage. AD has no successful treatment, and the close relationship between both diseases supports the study of antidiabetic drugs to limit or slow down brain pathology in AD. Empagliflozin (EMP) is a sodium-glucose co-transporter 2 inhibitor, the newest class of antidiabetic agents. EMP controls hyperglycemia and reduces cardiovascular comorbidities and deaths associated to T2D. Therefore, we have analyzed the role of EMP at the central level in a complex mouse model of AD-T2D. Methods We have treated AD-T2D mice (APP/PS1xdb/db mice) with EMP 10 mg/kg for 22 weeks. Glucose, insulin, and body weight were monthly assessed. We analyzed learning and memory in the Morris water maze and the new object discrimination test. Postmortem brain assessment was conducted to measure brain atrophy, senile plaques, and amyloid-beta levels. Tau phosphorylation, hemorrhage burden, and microglia were also measured in the brain after EMP treatment. Results EMP treatment helped to maintain insulin levels in diabetic mice. At the central level, EMP limited cortical thinning and reduced neuronal loss in treated mice. Hemorrhage and microglia burdens were also reduced in EMP-treated mice. Senile plaque burden was lower, and these effects were accompanied by an amelioration of cognitive deficits in APP/PS1xdb/db mice. Conclusions Altogether, our data support a feasible role for EMP to reduce brain complications associated to AD and T2D, including classical pathological features and vascular disease, and supporting further assessment of EMP at the central level

    The location of the tibial accelerometer does influence impact acceleration parameters during running

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    Tibial accelerations have been associated with a number of running injuries. However, studies attaching the tibial accelerometer on the proximal section are as numerous as those attaching the accelerometer on the distal section. This study aimed to investigate whether accelerometer location influences acceleration parameters commonly reported in running literature. To fulfil this purpose, 30 athletes ran at 2.22, 2.78 and 3.33 m · s–1 with three accelerometers attached with double-sided tape and tightened to the participants’ tolerance on the forehead, the proximal section of the tibia and the distal section of the tibia. Time-domain (peak acceleration, shock attenuation) and frequency-domain parameters (peak frequency, peak power, signal magnitude and shock attenuation in both the low and high frequency ranges) were calculated for each of the tibial locations. The distal accelerometer registered greater tibial acceleration peak and shock attenuation compared to the proximal accelerometer. With respect to the frequency-domain analysis, the distal accelerometer provided greater values of all the low-frequency parameters, whereas no difference was observed for the high-frequency parameters. These findings suggest that the location of the tibial accelerometer does influence the acceleration signal parameters, and thus, researchers should carefully consider the location they choose to place the accelerometer so that equivalent comparisons across studies can be made. © 2016 Informa UK Limited, trading as Taylor & Francis GroupThis study was supported by the Spanish Government [Ministerio de Educacion, Cultura y Deporte, Grant FPU12/00574; and Ministerio de Economia y Competitividad, Subdireccion General de Proyectos de Investigacion, Convocatoria Proyectos I+D "Excelencia", Subprograma de Generacion de Conocimiento, 2013, Grant DEP2013-48420-P].Lucas Cuevas, ÁG.; Encarnacion Martinez, A.; Camacho García, A.; Llana Belloch, S.; Pérez Soriano, P. (2016). The location of the tibial accelerometer does influence impact acceleration parameters during running. Journal of Sports Sciences. 35(17):1734-1738. https://doi.org/10.1080/02640414.2016.123579217341738351
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