Anatomical and functional brain approach along short abrupt changes in G-levels

To conduct experiments under abrupt changes in g-levels, a single-engine aerobatic aircraft has been used, providing 6-8 seconds of reduced gravity, preceded and followed by 5-7 seconds of hypergravity periods. Due to the specific conditions of the flight and previous findings [1], the hypothesis of the present work lies on the idea that some sensory inputs could have a notorious effect on brain final responses when gravity is altered. Therefore, this study focuses on the evaluation of such hypothesis, based on the analysis of the evolution in time of intracranial activity of limbic, visual and auditory cortices. Five subjects (N=5, age 41¿14 years) have flown in parabolic flight with their eyes both open and closed. Electroencephalogram signals were recorded with an Emotive Epoc headset, synchronized with a triaxial accelerometer. The intracranial brain bioelectric activity (standardized current density) throughout the parabola, was calculated by applying Standard Low Resolution Brain Electromagnetic Tomography, and it was analyzed for the limbic, visual and auditory cortices. Intracranial activity of the Temporal, Parietal and Occipital lobes were carried out as well in order to compare the different periods/phases of the flight. Results detected a lower brain activity during the hypogravity phase in all lobes and cortices, only in the case of open eyes. The bioelectrical brain activity along the parabola showed similar patterns in all lobes and cortices, when visual inputs are highlighted. Suppressing the sight, two major behaviors were detected in brain activity: one for temporal lobe and auditory cortex, and second one for the rest of the lobes and visual cortex. It Seemed that, flying with closed eyes, other sensory stimuli were enhanced, in this case the auditory cortex. To confirm the validity of the results two-way ANOVA (factors lobe/phases) and Fisher post hoc test have been applied on mean intracranial activity values in all cases. Spectral entropy evolution in time has been considered as a fast indicator of the sudden extracranial brain activity variation during short g-changes. For open eyes, spectral entropy values indicated a slight decrease at the onset of the hypogravity phase, whereas in case of closed eyes, this change was detected in the last seconds of the parabola, even though these fluctuations were statistically non-significant. Results suggest that some of the sensory inputs can indeed have an impact on brain final response, when gravity conditions are altered.Peer ReviewedPostprint (published version

Search for Long-Lived Heavy Neutrinos at the LHC with a VBF Trigger

The charged current production of long-lived heavy neutrinos at the LHC can use a prompt charged lepton for triggering the measurement of the process. However, in order to fully characterize the heavy neutrino interactions, it is necessary to also probe Higgs or $Z$ mediated neutral current production. In this case the charged lepton is not available, so other means of triggering are required. In this work, we explore the possibility of using a vector boson fusion trigger in the context of a GeV-scale Type I Seesaw model. We consider a minimal model, where both Higgs and Z-mediated contributions produce one heavy neutrino, as well as an extended model where the Higgs can decay into two heavy ones. Both scenarios are tested through displaced dilepton and displaced multitrack jet searches.Comment: 31 pages, 1 appendix, 5 figures; v2: improved version, accepted for publication in EPJ

Anti-Angiogenic Treatment (Sunitinib) for Disseminated Malignant Haemangiopericytoma: A Case Study and Review of the Literature

Introduction: A meningeal haemangiopericytoma (HP) is a mesenchymal tumour that makes up less than 1% of all CNS tumours. HPs arise from pericytes and present high rates of recurrence and distant metastasis. The primary treatment option is surgery. When the disease is disseminated, chemotherapy produces a weak and short-lived response; therefore, new drugs are needed. Case Presentation: We describe the case of a 65-year-old woman with a 13-year history of recurrent HP. After local treatment with radiotherapy, she developed metastases that required systemic treatment, and treatment with sunitinib, an oral inhibitor of the vascular endothelial growth factor receptor and the platelet-derived growth factor receptor, was initiated. As a result, radiological stabilisation of the systemic disease was maintained for over 12 months. Conclusions: Anti-angiogenic agents can be useful for treating disseminated HP, but further studies are needed to confirm their possible role in controlling metastatic disease

A zinc-doped endodontic cement facilitates functional mineralization and stress dissipation at the dentin surface

The purpose of this study was to evaluate nanohardness and viscoelastic behavior of dentin surfaces treated with two canal sealer cements for dentin remineralization. Dentin surfaces were subjected to: i) 37% phosphoric acid (PA) or ii) 0.5 M ethylenediaminetetraacetic acid (EDTA) conditioning prior to the application of two experimental hydroxyapatite-based cements, containing sodium hydroxide (calcypatite) or zinc oxide (oxipatite), respectively. Samples were stored in simulated body fluid during 24 h or 21 d. The intertubular and peritubular dentin were evaluated using a nanoindenter to assess nanohardness (Hi). The load/displacement responses were used for the nano-dynamic mechanical analysis to estimate complex modulus (E*) and tan delta (?). The modulus mapping was obtained by imposing a quasistatic force setpoint to which a sinusoidal force was superimposed. AFM imaging and FESEM analysis were performed. After 21 d of storage, dentin surfaces treated with EDTA+calcypatite, PA+calcypatite and EDTA+oxipatite showed viscoelastic discrepancies between peritubular and intertubular dentin, meaning a risk for cracking and breakdown of the surface. At both 24 h and 21 d, tan ? values at intertubular dentin treated with the four treatments performed similar. At 21 d time point, intertubular dentin treated with PA+oxipatite achieved the highest complex modulus and nanohardness, i.e., highest resistance to deformation and functional mineralization, among groups. Intertubular and peritubular dentin treated with PA+oxipatite showed similar values of tan ? after 21 d of storage. This produced a favorable dissipation of energy with minimal energy concentration, preserving the structural integrity at the dentin surface

Ac magnetic susceptibility of a molecular magnet submonolayer directly patterned onto a microSQUID sensor

We report the controlled integration, via Dip Pen Nanolithography, of monolayer dots of ferritin-based CoO nanoparticles (12 Bohr magnetons) into the most sensitive areas of a microSQUID sensor. The nearly optimum flux coupling between these nanomagnets and the microSQUID improves the achievable sensitivity by a factor 100, enabling us to measure the linear susceptibility of the molecular array down to very low temperatures (13 mK). This method opens the possibility of applying ac susceptibility experiments to characterize two-dimensional arrays of single molecule magnets within a wide range of temperatures and frequencies.Comment: 4 pages 3 figure

Obtención de cemento eco-eficiente a base de ceniza procedente de caldera de lecho fluidizado

El objetivo principal de este trabajo ha sido la valorización de una ceniza procedente de un combustor de lecho fluidizado de biomasa forestal (CCBF) para su posible empleo como adición puzolánica con el fin de obtener un material base cemento más ecoeficiente. Esta ceniza es un residuo procedente de un combustor que es alimentado fundamentalmente por restos de corteza de eucalipto para la fabricación de pasta de papel, originando toneladas de dichas cenizas. La ceniza CCBF tiene importantes contenidos en SiO2, CaO, Al2O3 y K2O, como componentes mayoritarios. Estos óxidos la hacen atractiva para el campo de los materiales de construcción. Para su valorización se somete a la ceniza a un tratamiento hidrotermal (TH) durante un periodo de 4h a dos temperaturas (150 y 200ºC) en contacto con dos medios, agua desmineralizada y una disolución de NaOH 1M, en ambos casos se ha empleado una relación líquido/sólido de 10. Los cambios que se producen en la fase sólida resultante del TH se analizan mediante diferentes técnicas de caracterización Después del TH, se identifica, como fase predominante, la fase tipo tobermorita, precursora del gel C-S-H. La obtención de dicha fase, se optimiza durante el TH a 200ºC, temperatura en la que desapareen prácticamente la fase cuarzo y disminuye la de calcita, lo que favorece la formación de las fases tobermorita por incorporación de iones calcio y silicio, a su estructura. Previa a la incorporación de la ceniza a la matriz de cemento es necesario determinar su activididad puzolánica. Por ello, se ha estudiado la actividad puzolánica de la ceniza CCBF y de la ceniza CCBF activada hidrotermalmente (200ºC/4h). Para determinar esta activiad se ha empleado en ambos casos el método de la disolución saturada de cal, desarrollado en el Instituto Ciencias de la Construcción “Eduardo Torroja”. En ambas cenizas, CCBF y CCBF-200º/4h, se alcanzan valores de cal fijada a los 28 días, de 52,1 y 98,2% respectivamente. Debido a la alta actividad puzolánica que presentan, se procedió a una sustitución parcial de cemento Portland por ambas cenizas, en porcentajes del 0, 10 y 20% del cemento por ceniza, según la EN 196-3. Para evaluar el efecto de las mismas, se fabricaron probetas de 1x1x6cm, las cuales se sometieron a pruebas de resistencia mecánica a compresión a diferentes edades de hidratación (2, 7 y 28 días). Se pudo observar como con la adición de ambos tipos de ceniza mejoraba hasta un 30% la resistencia mecánica a los 28 días en relación a la referencia (0%), obteniendo mayores resistencias en ambos casos (CCBF y CCBF-200ºC-4h) con el 10% de sustitució

Diseño y validación analítica de una PCR duplex para la detección de Ehrlichia y Rickettsia en garrapatas

ABSTRACT: Ehrlichia and Rickettsia are two major rickettsial genera transmitted by ticks that affect a number of wild and domestic animal species and human populations around the world. Objective: To design and validate a duplex PCR for Ehrlichia and Rickettsia in ticks. Methods:Assay validation included testing for sensitivity,specificity, reproducibility, and robustness of the PCR. The groELand 23sr RNAgenes were used for Ehrlichia and Rickettsia, respectively. Results: The limit of detection was one hundred gene copies per 50 μLof reaction for Ehrlichia spp, and one gene copy of Rickettsia per 50 μL of reaction. In general, the primers of the test only amplified in silico those bacterial agents for which they were originally designed, with the exception of the primers for Rickettsia that also amplified Methylocystis sp. The test was reproducible (intermediate precision) 96.7% of the times for both agents. The test was robust enough to tolerate concentration changes of all reagents with the exception of Taq DNA polymerase. Conclusions: The validation results indicated that this PCR is useful for detection in both bacterial genera and it is a good candidate for diagnostic validation.RESUMEN: Ehrlichia spp. y Rickettsia spp.son dos de los principales géneros rickettsiales transmitidos por garrapatas que afectan a animales silvestres, domésticos y humanos alrededor del mundo. Objetivo: diseñar y validar una prueba PCR duplex para Ehrlichia y Rickettsia en garrapatas. Métodos: la validación de la prueba incluyó ensayos de sensibilidad, especificidad, reproducibilidad y robustez. En la PCR se usó groEL y ARNr 23S como genes blanco para Ehrlichia y Rickettsia, respectivamente. Resultados: el límite de detección fue de 100 copias del gen por 50 μL de reacción para Ehrlichia spp y una copia del gen de Rickettsia por 50 μLde reacción. En general, los cebadores de la prueba solo amplificaron in silico los agentes bacterianos para los cuales fueron originalmente diseñados, con la excepción de los cebadores de Rickettsia que también amplificaron Methylocystis sp. La prueba fue reproducible (precisión intermedia) en un 96.7% de las veces para ambos agentes. La prueba fue suficientemente robusta como para tolerar cambios de concentración de los diferentes reactivos, con excepción de la Taq DNA polimerasa. Conclusión: los resultados de validación indican que la PCR es útil para detectar ambos géneros bacterianos y podría usarse para validación diagnóstica

Expression and characterization of the Trypanosoma cruzi dihydrofolate reductase domain

We have cloned and expressed in Escherichia coli a 702-base pair gene coding for the dihydrofolate reductase (DHFR) domain of the bifunctional dihydrofolate reductase-thymidylate synthase (DHFR-TS) from Trypanosoma cruzi. The DHFR domain was purified to homogeneity by methotrexate-Sepharose chromatography followed by an anion-exchange chromatography step in a mono Q column, and displayed a single 27-kDa band on SDS-PAGE. Gel filtration showed that the catalytic domain was expressed as a monomer. Kinetic parameters were similar to those reported for the wild-type bifunctional enzyme with Km values of 0.75 microM for dihydrofolate and 16 microM for NADPH and a kcat value of 16.5 s-1. T. cruzi DHFR is poorly inhibited by trimethoprim and pyrimethamine and the inhibition constants were always lower for the bifunctional enzyme. The binding of methotrexate was characteristic of a class of inhibitors that form an initial complex which isomerizes slowly to a tighter complex and are referred to as 'slow, tight-binding' inhibitors. While the slow-binding step of inhibition was apparently unaffected in the individually expressed DHFR domain, the overall inhibition constant was two-fold higher as a consequence of the superior inhibition constant value obtained for the initial inhibitory complex

New multifunctional sulfonato-containing metal phosphonates proton conductors

Anchoring of acidic functional groups to organic linkers acting as ligands in metal phosphonates has been demonstrate to be a valid strategy to develop new proton conductor materials, which exhibit tunable properties and are potentially applicable to proton exchange membranes, such as those used in PEMFCs [1,2]. In this work, the structural and proton conductivity properties of several families of divalent and trivalent metal amino-sulfophosphonates are presented. The chosen ligand, (H2O3PCH2)2-N-(CH2)2-SO3H, was reacted with the appropriate metal salt using highthrough-put screening and/or microwave-assisted synthesis. Different crystal structures haven been solved displaying a variety of metal ligand coordination modes, in whose frameworks acidic groups contribute to create strong H-bond networks; together with lattice and bound water molecules. Proton conductivity values oscillate between 10-4 and 10-2 S.cm-1, at 80 ºC and 95 % relative humidity, most of them showing activation energies characteristic of a Grotthuss-type proton transport mechanism.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. MINECO: MAT2016-77648-R Junta de Andalucía: P-12-FQM-1656 y FQM-11