175 research outputs found

    Effect of a heterotrimeric G protein α subunit on conidia germination, stress response, and roquefortine C production in Penicillium roqueforti

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    Summary. Heterotrimeric G protein signaling regulates many processes in fungi, such as development, pathogenicity, and secondary metabolite biosynthesis. For example, the Gα subunit Pga1 from Penicillium chrysogenum regulates conidiation and secondary metabolite production in this fungus. The dominant activating allele, pga1G42R, encoding a constitutively active Pga1 Gα subunit, was introduced in Penicillium roqueforti by transformation, resulting in a phenotype characterized by low sporulation and slow growth. In this work, the effect of the constitutively active Pga1G42R Gα subunit on conidial germination, stress tolerance, and roquefortine C production of P. roqueforti was studied. Pga1G42R triggered germination in the absence of a carbon source, in addition to negatively regulating thermal and osmotic stress tolerance. The presence of the Pga1G42R Gα subunit also had an important effect on roquefortine C biosynthesis, increasing production and maintaining high levels of the mycotoxin throughout a culture period of 30 days. Together, the results suggest that G protein-mediated signaling participates in the regulation of these three processes in P. roqueforti. [Int Microbiol 2009; 12(2):123-129

    First detection of the 448 GHz H2O transition in space

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    We present the first detection of the ortho-H2O 4_23-3_30 transition at 448 GHz in space. We observed this transition in the local (z = 0.010) luminous infrared (IR) galaxy ESO 320-G030 (IRAS F11506-3851) using the Atacama Large Millimeter/submillimeter Array (ALMA). The water 4_23-3_30 emission, which originates in the highly obscured nucleus of this galaxy, is spatially resolved over a region of ~65 pc in diameter and shows a regular rotation pattern compatible with the global molecular and ionized gas kinematics. The line profile is symmetric and well fitted by a Gaussian with an integrated flux of 37.0 +- 0.7 Jy km s-1 . Models predict this water transition as a potential collisionally excited maser transition. On the contrary, in this galaxy, we find that the 4_23-3_30 emission is primarily excited by the intense far-IR radiation field present in its nucleus. According to our modeling, this transition is a probe of deeply buried galaxy nuclei thanks to the high dust optical depths (tau_100{\mu}m > 1, N_H > 1e24 cm-2) required to efficiently excite it.Comment: Accepted for publication in A&A Letters; 4 pages, 5 figure

    Spectral Line Identification and Modelling (SLIM) in the MAdrid Data CUBe Analysis (MADCUBA) package: An interactive software for data cube analysis

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    In this paper we present the detailed formalism at the core of the Spectral Line Identification and Modelling (SLIM) within the MAdrid Data CUBe Analysis (MADCUBA) package and their main data handling functionalities. These tools have been developed to visualize, analyze and model large spectroscopic data cubes. We present the highly interactive on-the-fly visualization and modelling tools of MADCUBA and SLIM, which includes an stand-alone spectroscopic database. The parameters stored therein are used to solve the full radiative transfer equation under Local Thermodynamic Equilibrium (LTE). SLIM provides tools to generate synthetic LTE model spectra based on input physical parameters of column density, excitation temperature, velocity, line width and source size. SLIM also provides an automatic fitting algorithm to obtain the physical parameters (with their associated errors) better fitting the observations. Synthetic spectra can be overlayed in the data cubes/spectra to easy the task of multi-molecular line identification and modelling.We present the Java-based MADCUBA and its internal module SLIM packages which provide all the necessary tools for manipulation and analysis of spectroscopic data cubes. We describe in detail the spectroscopic fitting equations and make use of this tool to explore the breaking conditions and implicit errors of commonly used approximations in the literature. Easy-to-use tools like MADCUBA allow the users to derive the physical information from spectroscopic data without the need of resourcing to simple approximations. SLIM allows to use the full radiative transfer equation, and to interactively explore the space of physical parameters and associated uncertainties from observational data.Comment: 18 pages, 7 Figures, Accepted for publication in A&

    Characterization of the Hamamatsu S8664 Avalanche Photodiode for X-Ray and VUV-light detection

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    We present the first operation of the Avalanche Photodiode (APD) from Hamamatsu to xenon scintillation light and to direct X-rays of 22.1 keV and 5.9 keV. A large non-linear response was observed for the direct X-ray detection. At 415 V APD bias voltage it was of about 30 % for 22.1 keV and about 45 % for 5.9 keV. The quantum efficiency for 172 nm photons has been measured to be 69 +/- 15 %.Comment: 11 pages, 3 figures, submitted to Elsevie

    Structure, morphology, adhesion and in vitro biological evaluation of antibacterial multi-layer HA-Ag/SiO2/TiN/Ti coatings obtained by RF magnetron sputtering for biomedical applications

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    [EN] Biocompatible and antibacterial multi-layer coatings of hydroxyapatite (HA)-Ag/SiO2/TiN/Ti were obtained on the Ti-6Al-4V alloy, by means of the magnetron sputtering technique. During characterization of the coatings, the chemical composition was evaluated by energy dispersive X-ray spectroscopy and the phase analysis was carried out by X-ray diffraction. The morphology of the coatings was observed by field emission scanning electron microscopy, while transmission electron microscopy was used to appreciate their structure. The adhesion of the coatings to the substrate was evaluated by micro scratch test. The in vitro biological response was evaluated in terms of cytotoxicity, adhesion and differentiation of mouse mesenchymal stem cells, as well as adhesion and bacterial viability of Staphylococcus aureus strain. Through the compositional study carried out, the deposition of the HA phase was verified, with a Ca/P ratio close to 1.67 and the characteristic diffraction peaks of this compound. The structural study of the coatings evidenced the obtention of multi-layer architectures. The use of an intermediate SiO2/TiN/Ti trilayer was found to improve adhesion between HA-Ag and the substrate by 84%. Finally, the in vitro biological tests carried out indicated a potentially non-toxic character in the coatings. Additionally, an antibacterial effect was registered at low concentrations of Ag (3.0.co;2-3Lalueza, P., Monzón, M., Arruebo, M., & Santamaría, J. (2011). Bactericidal effects of different silver-containing materials. Materials Research Bulletin, 46(11), 2070-2076. doi:10.1016/j.materresbull.2011.06.041Peetsch, A., Greulich, C., Braun, D., Stroetges, C., Rehage, H., Siebers, B., … Epple, M. (2013). Silver-doped calcium phosphate nanoparticles: Synthesis, characterization, and toxic effects toward mammalian and prokaryotic cells. Colloids and Surfaces B: Biointerfaces, 102, 724-729. doi:10.1016/j.colsurfb.2012.09.040Yanovska, A. A., Stanislavov, A. S., Sukhodub, L. B., Kuznetsov, V. N., Illiashenko, V. Y., Danilchenko, S. N., & Sukhodub, L. F. (2014). Silver-doped hydroxyapatite coatings formed on Ti–6Al–4V substrates and their characterization. Materials Science and Engineering: C, 36, 215-220. doi:10.1016/j.msec.2013.12.011DeVasConCellos, P., Bose, S., Beyenal, H., Bandyopadhyay, A., & Zirkle, L. G. (2012). Antimicrobial particulate silver coatings on stainless steel implants for fracture management. Materials Science and Engineering: C, 32(5), 1112-1120. doi:10.1016/j.msec.2012.02.020VALLETREGI, M. (2004). Calcium phosphates as substitution of bone tissues. Progress in Solid State Chemistry, 32(1-2), 1-31. doi:10.1016/j.progsolidstchem.2004.07.001Surmenev, R. A., Surmeneva, M. A., Evdokimov, K. E., Pichugin, V. F., Peitsch, T., & Epple, M. (2011). The influence of the deposition parameters on the properties of an rf-magnetron-deposited nanostructured calcium phosphate coating and a possible growth mechanism. Surface and Coatings Technology, 205(12), 3600-3606. doi:10.1016/j.surfcoat.2010.12.039Surmeneva, M. A., Sharonova, A. A., Chernousova, S., Prymak, O., Loza, K., Tkachev, M. S., … Surmenev, R. A. (2017). Incorporation of silver nanoparticles into magnetron-sputtered calcium phosphate layers on titanium as an antibacterial coating. Colloids and Surfaces B: Biointerfaces, 156, 104-113. doi:10.1016/j.colsurfb.2017.05.016Mohseni, E., Zalnezhad, E., Bushroa, A. R., Abdel Magid Hamouda, Goh, B. T., & Yoon, G. H. (2015). Ti/TiN/HA coating on Ti–6Al–4V for biomedical applications. Ceramics International, 41(10), 14447-14457. doi:10.1016/j.ceramint.2015.07.081Ghasemi, S., Shanaghi, A., & Chu, P. K. (2017). Nano mechanical and wear properties of multi-layer Ti/TiN coatings deposited on Al 7075 by high-vacuum magnetron sputtering. Thin Solid Films, 638, 96-104. doi:10.1016/j.tsf.2017.07.049Hamdi, D. A., Jiang, Z.-T., No, K., Rahman, M. M., Lee, P.-C., Truc, L. N. T., … Dlugogorski, B. Z. (2019). Biocompatibility study of multi-layered hydroxyapatite coatings synthesized on Ti-6Al-4V alloys by RF magnetron sputtering for prosthetic-orthopaedic implant applications. Applied Surface Science, 463, 292-299. doi:10.1016/j.apsusc.2018.08.157Qi, J., Yang, Y., Zhou, M., Chen, Z., & Chen, K. (2019). Effect of transition layer on the performance of hydroxyapatite/titanium nitride coating developed on Ti-6Al-4V alloy by magnetron sputtering. Ceramics International, 45(4), 4863-4869. doi:10.1016/j.ceramint.2018.11.183Lenis, J. A., Hurtado, F. M., Gómez, M. A., & Bolívar, F. J. (2019). Effect of thermal treatment on structure, phase and mechanical properties of hydroxyapatite thin films grown by RF magnetron sputtering. Thin Solid Films, 669, 571-578. doi:10.1016/j.tsf.2018.11.045Lenis, J. A., Gómez, M. A., & Bolívar, F. J. (2019). Effect of deposition temperature and target-substrate distance on the structure, phases, mechanical and tribological properties of multi-layer HA-Ag coatings obtained by RF magnetron sputtering. Surface and Coatings Technology, 378, 124936. doi:10.1016/j.surfcoat.2019.124936Sofronia, A. M., Baies, R., Anghel, E. M., Marinescu, C. A., & Tanasescu, S. (2014). Thermal and structural characterization of synthetic and natural nanocrystalline hydroxyapatite. Materials Science and Engineering: C, 43, 153-163. doi:10.1016/j.msec.2014.07.023Lenis, J. A., Bejarano, G., Rico, P., Ribelles, J. L. G., & Bolívar, F. J. (2019). Development of multilayer Hydroxyapatite - Ag/TiN-Ti coatings deposited by radio frequency magnetron sputtering with potential application in the biomedical field. Surface and Coatings Technology, 377, 124856. doi:10.1016/j.surfcoat.2019.06.097Lenis, J. A., Toro, L. J., & Bolívar, F. J. (2019). Multi-layer bactericidal silver - calcium phosphate coatings obtained by RF magnetron sputtering. Surface and Coatings Technology, 367, 203-211. doi:10.1016/j.surfcoat.2019.03.038Valverde, A., Pérez-Álvarez, L., Ruiz-Rubio, L., Pacha Olivenza, M. A., García Blanco, M. B., Díaz-Fuentes, M., & Vilas-Vilela, J. L. (2019). Antibacterial hyaluronic acid/chitosan multilayers onto smooth and micropatterned titanium surfaces. Carbohydrate Polymers, 207, 824-833. doi:10.1016/j.carbpol.2018.12.039Surmeneva, M. A., Chaikina, M. V., Zaikovskiy, V. I., Pichugin, V. F., Buck, V., Prymak, O., … Surmenev, R. A. (2013). The structure of an RF-magnetron sputter-deposited silicate-containing hydroxyapatite-based coating investigated by high-resolution techniques. Surface and Coatings Technology, 218, 39-46. doi:10.1016/j.surfcoat.2012.12.023Nelea, V., Morosanu, C., Iliescu, M., & Mihailescu, I. N. (2003). Microstructure and mechanical properties of hydroxyapatite thin films grown by RF magnetron sputtering. Surface and Coatings Technology, 173(2-3), 315-322. doi:10.1016/s0257-8972(03)00729-1Ding, S.-J., Ju, C.-P., & Lin, J.-H. C. (1999). Characterization of hydroxyapatite and titanium coatings sputtered on Ti-6Al-4V substrate. Journal of Biomedical Materials Research, 44(3), 266-279. doi:10.1002/(sici)1097-4636(19990305)44:33.0.co;2-4Ivanova, A. A., Surmeneva, M. A., Tyurin, A. I., Pirozhkova, T. S., Shuvarin, I. A., Prymak, O., … Surmenev, R. A. (2016). Fabrication and physico-mechanical properties of thin magnetron sputter deposited silver-containing hydroxyapatite films. Applied Surface Science, 360, 929-935. doi:10.1016/j.apsusc.2015.11.087Contreras Romero, E., Cortínez Osorio, J., Talamantes Soto, R., Hurtado Macías, A., & Gómez Botero, M. (2019). Microstructure, mechanical and tribological performance of nanostructured TiAlTaN-(TiAlN/TaN)n coatings: Understanding the effect of quaternary/multilayer volume fraction. Surface and Coatings Technology, 377, 124875. doi:10.1016/j.surfcoat.2019.07.086Deligianni, D. (2001). Effect of surface roughness of the titanium alloy Ti–6Al–4V on human bone marrow cell response and on protein adsorption. Biomaterials, 22(11), 1241-1251. doi:10.1016/s0142-9612(00)00274-xZareidoost, A., Yousefpour, M., Ghaseme, B., & Amanzadeh, A. (2012). The relationship of surface roughness and cell response of chemical surface modification of titanium. Journal of Materials Science: Materials in Medicine, 23(6), 1479-1488. doi:10.1007/s10856-012-4611-9Surmeneva, M. A., Tyurin, A. I., Mukhametkaliyev, T. M., Pirozhkova, T. S., Shuvarin, I. A., Syrtanov, M. S., & Surmenev, R. A. (2015). Enhancement of the mechanical properties of AZ31 magnesium alloy via nanostructured hydroxyapatite thin films fabricated via radio-frequency magnetron sputtering. Journal of the Mechanical Behavior of Biomedical Materials, 46, 127-136. doi:10.1016/j.jmbbm.2015.02.025Quirama, A., Echavarría, A. M., Meza, J. M., Osorio, J., & Bejarano G, G. (2017). Improvement of the mechanical behavior of the calcium phosphate coatings deposited onto Ti6Al4V alloy using an intermediate TiN/TiO2 bilayer. Vacuum, 146, 22-30. doi:10.1016/j.vacuum.2017.09.024Surmeneva, M. A., Kleinhans, C., Vacun, G., Kluger, P. J., Schönhaar, V., Müller, M., … Surmenev, R. A. (2015). Nano-hydroxyapatite-coated metal-ceramic composite of iron-tricalcium phosphate: Improving the surface wettability, adhesion and proliferation of mesenchymal stem cells in vitro. Colloids and Surfaces B: Biointerfaces, 135, 386-393. doi:10.1016/j.colsurfb.2015.07.057Chen, Y., Zheng, X., Xie, Y., Ji, H., Ding, C., Li, H., & Dai, K. (2010). Silver release from silver-containing hydroxyapatite coatings. Surface and Coatings Technology, 205(7), 1892-1896. doi:10.1016/j.surfcoat.2010.08.073Actis, L., Gaviria, L., Guda, T., & Ong, J. L. (2013). Antimicrobial surfaces for craniofacial implants: state of the art. Journal of the Korean Association of Oral and Maxillofacial Surgeons, 39(2), 43. doi:10.5125/jkaoms.2013.39.2.43Parvizi, J., Aggarwal, V., & Rasouli, M. (2013). Periprosthetic joint infection: Current concept. Indian Journal of Orthopaedics, 47(1), 10. doi:10.4103/0019-5413.106884Redey, S. A., Nardin, M., Bernache-Assolant, D., Rey, C., Delannoy, P., Sedel, L., & Marie, P. J. (2000). Behavior of human osteoblastic cells on stoichiometric hydroxyapatite and type A carbonate apatite: Role of surface energy. Journal of Biomedical Materials Research, 50(3), 353-364. doi:10.1002/(sici)1097-4636(20000605)50:33.0.co;2-cSpriano, S., Bosetti, M., Bronzoni, M., Vernè, E., Maina, G., Bergo, V., & Cannas, M. (2005). Surface properties and cell response of low metal ion release Ti-6Al-7Nb alloy after multi-step chemical and thermal treatments. Biomaterials, 26(11), 1219-1229. doi:10.1016/j.biomaterials.2004.04.026Vogler, E. A. (1999). Water and the acute biological response to surfaces. Journal of Biomaterials Science, Polymer Edition, 10(10), 1015-1045. doi:10.1163/156856299x00667Lim, J. Y., Liu, X., Vogler, E. A., & Donahue, H. J. (2004). Systematic variation in osteoblast adhesion and phenotype with substratum surface characteristics. Journal of Biomedical Materials Research, 68A(3), 504-512. doi:10.1002/jbm.a.20087Sengstock, C., Diendorf, J., Epple, M., Schildhauer, T. A., & Köller, M. (2014). Effect of silver nanoparticles on human mesenchymal stem cell differentiation. Beilstein Journal of Nanotechnology, 5, 2058-2069. doi:10.3762/bjnano.5.214Sahuquillo Arce, J. M., Iranzo Tatay, A., Llácer Luna, M., Sanchis Boix, Y., Guitán Deltell, J., González Barberá, E., … Gobernado Serrano, M. (2011). Estudio in vitro de las propiedades antimicrobianas de una espuma de poliuretano que libera iones de plata. Cirugía Española, 89(8), 532-538. doi:10.1016/j.ciresp.2011.02.015Jamuna-Thevi, K., Bakar, S. A., Ibrahim, S., Shahab, N., & Toff, M. R. M. (2011). Quantification of silver ion release, in vitro cytotoxicity and antibacterial properties of nanostuctured Ag doped TiO2 coatings on stainless steel deposited by RF magnetron sputtering. Vacuum, 86(3), 235-241. doi:10.1016/j.vacuum.2011.06.011Chernousova, S., & Epple, M. (2012). Silver as Antibacterial Agent: Ion, Nanoparticle, and Metal. Angewandte Chemie International Edition, 52(6), 1636-1653. doi:10.1002/anie.20120592

    Cardio-ankle vascular index (CAVI) measured by a new device: protocol for a validation study

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    This study was funded by Consejeria de Economia e Infraestructura de la Junta de Extremadura (Spain) (Grant no: IB16218).Introduction Cardio-ankle vascular index (CAVI) is a new marker of arterial stiffness (AS) that can assess vascular wall stiffness in the aorta, femoral artery and tibial artery. CAVI is less affected by blood pressure at the time of measurement than the gold standard method (carotid-femoral pulse wave velocity (PWV)). Our group has developed a device called VOPITB (Velocidad Onda de Pulso Índice Tobillo Brazo) that uses the oscillometric method and easily and accurately measures the PWV in the arms and legs separately, allowing new AS indices to be studied. This article describes the research protocol to determine CAVI using VOPITB and to validate the device against a reference device (VaSera VS-1500) and assess its clinical utility. Methods and analyses A cross-sectional, descriptive and observational study will be conducted. In all, 120 subjects (a minimum of 40% of subjects from any one gender) will be evaluated. CAVI will be determined from the measurement by VOPITB and VaSera VS-1500. For each subject, the average of the three readings taken with each device will be calculated. The Bland-Altman plot will be used to determine whether any bias exists in the data -that is, a tendency of the size of the difference to vary with the mean. The participants will be divided roughly equally between the following age bands: 60 years. Ethics and dissemination The study has been approved by the ethics committee of the Hospital San Pedro de Alcántara, Cáceres, Spain. The participants will be required to sign an informed consent form before inclusion in the study, in accordance with the Declaration of Helsinki and WHO standards for observational studies. The dissemination plan of the research study results will be through presentations in relevant national and international conferences and scientific publications in peer-reviewed journals. Trial registration number NCT04303546.publishersversionpublishe

    Air and wet bulb temperature lapse rates and their impact on snowmaking in a Pyrenean ski resort

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    A set of 17 air temperature and relative humidity sensors were used to analyze the temporal variability of surface air temperature (Tair), wet bulb temperature (Twb), and daily snowmaking hours (SM, number of hours per day with Twb < − 2 °C), lapse rates, and the occurrence of thermal inversions at the Formigal ski resort (Spanish Pyrenees) from December to March during three consecutive ski seasons (2012–2013, 2013–2014, and 2014–2015). The Tair and Twb lapse rates showed strong hourly and daily variability, with both exhibiting almost identical temporal fluctuations. The Twb exhibited average lapse rates that were slightly steeper (− 5.2 °C/km) than those observed for Tair (− 4.9 °C/km). The less steep lapse rates and most thermal inversions were observed in December. Days having less (more) steep Tair and Twb lapse rates were observed under low (high) wind speeds and high (low) relative humidity and air pressure. The temporal dynamics of the SM lapse rates was more complex, as this involved consideration of the average Tair in the ski resort, in addition to the driving factors of the spatio-temporal variability of Twb. Thus, on a number of cold (warm) days, snowmaking was feasible at all elevations at the ski resort, independently of the slopes of the lapse rates. The SM exhibited an average daily lapse rate of 8.2 h/km, with a progressive trend of increase from December to March. Weather types over the Iberian Peninsula tightly control the driving factors of the Tair, Twb, and SM lapse rates (wind speed, relative humidity, and Tair), so the slopes of the lapse rates and the frequency of inversions in relation to elevation for the three variables are very dependent on the occurrence of specific weather types. The less steep lapse rates occurred associated with advections from the southeast, although low lapse rates also occurred during advections from the east and south, and under anticyclonic conditions. The steepest Tair and Twb lapse rates were observed during north and northwest advections, while the steepest rates for SM were observed during days of cyclonic circulation and advections from the northeast.This study was funded by the research project CGL2014-52599-P "Estudio del manto de nieve en la montaña española y su respuesta a la variabilidad y cambio climatico" (Ministry of Economy and Development, MINECO)

    Feedback and feeding in the context of galaxy evolution with SPICA: direct characterization of molecular outflows and inflows

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    A far-infrared observatory such as the {\it SPace Infrared telescope for Cosmology and Astrophysics} ({\it SPICA}), with its unprecedented spectroscopic sensitivity, would unveil the role of feedback in galaxy evolution during the last 10\sim10 Gyr of the Universe (z=1.52z=1.5-2), through the use of far- and mid-infrared molecular and ionic fine structure lines that trace outflowing and infalling gas. Outflowing gas is identified in the far-infrared through P-Cygni line shapes and absorption blueshifted wings in molecular lines with high dipolar moments, and through emission line wings of fine-structure lines of ionized gas. We quantify the detectability of galaxy-scale massive molecular and ionized outflows as a function of redshift in AGN-dominated, starburst-dominated, and main-sequence galaxies, explore the detectability of metal-rich inflows in the local Universe, and describe the most significant synergies with other current and future observatories that will measure feedback in galaxies via complementary tracers at other wavelengths.Comment: This paper belongs to the SPICA Special Issue on PASA. Accepted for publication in PAS
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