860 research outputs found

    Conjunctival Melanoma: A New Clinical and Therapeutical Approach

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    Melanoma involving the conjunctiva is extremely rare. Graver prognosis has been reported with primary conjunctival melanoma than with their cutaneous counterparts [Collin et al.: Aust N Z J Ophthalmol 1986;14:29–34]. Among conjunctival melanomas, two significant risk factors for tumour-related death have been identified: (i) age older than 55 years and (ii) unfavourable tumour location (caruncle, cornea, fornix, palpebral conjunctiva) [Werschnik and Lommatzsch: Am J Clin Oncol 2002;25:248–255]. Here we present a rare case of lentigo maligna involving the palpebral, bulbar conjunctiva and the caruncle. We describe dermoscopic patterns observed and the use of a novel ocular melanoma therapy with topical imiquimod

    ¿Es adecuado el sistema español de evaluación de la actividad investigadora para su aplicación a las Ciencias de la Tierra y otros campos afines?

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    Through the survey «Research activities in the R&D system in Earth Sciences in Spain (1990-1994)>>, information about different aspects of the professional activity of Spanish researchers in this field has been retrieved, as well as their opinion about prevailing research evaluation criteria. Starting from survey's results, we discuss the suitability of the present Spanish scientific evaluation system for assessing research activity of said researchers. Results show scientist's disagreement with the prevailing evaluation procedures and criteria. More than 70 % of both University and CSIC researchers consider that evaluation criteria are inappropriate or unacceptable, being this percentage significantly higher than the obtained from scientists belonging to other institutions. Disagreement with evaluation criteria is significantly lower among authors that only publish in foreign journals. Positive correlation has been found between opinion about evaluation criteria and the level of consolidation and stability of research teams. Main cause of disagreement is concerned with the over-valuation of papers published in SCI journals and the scarce consideration given to high quality papers published in serious domestic journals and to other scientific contributions. Results suggest that the evaluation system could have been detrimental to researchers working in some scientific fields, but does not seem to have discriminate among basic and applied research or among research of local or national interest and those more internationally-oriented. The research evaluation system should consider the idiosyncrasy of the different scientific fields, as well as their particular and distinctive characteristics and dynamics. It should take into the adequate consideration quality scientific work that, despite being of particular importance in fields as Earth Sciences, is not published in SCI joumals.A través de la opinión expresada por los propios investigadores, se discute la idoneidad del actual sistema español de evaluación de la actividad investigadora, para su aplicación en el campo de las Ciencias de la Tierra. Dicha opinión ha sido obtenida a través de la encuesta «Actividades de investigación realizadas en el Sistema de I+D en Ciencias de la Tierra en España, 1990-1994», que recoge información sobre distintos aspectos de la actividad profesional de los investigadores españoles en este campo. Los resultados muestran su desacuerdo con los criterios y el procedimiento de evaluación actualmente vigentes. Más del 70 % tanto de los profesores universitarios como de los investigadores del CSIC considera que los criterios de evaluación son inadecuados o inaceptables, siendo su grado de disconformidad con los mismos significativamente más elevado que el de los investigadores del resto de instituciones. Este porcentaje es significativamente menor entre los científicos que publican exclusivamente en revistas extranjeras. Asimismo, se ha detectado una correlación positiva entre la opinión acerca de los criterios de evaluación y el nivel de consolidación y estabilidad de los equipos de investigación, de modo que cuanto mayor es éste más elevada es la proporción de juicios favorables a los mismos. El principal motivo de disconformidad con el procedimiento de evaluación se refiere a la excesiva importancia que se concede a los trabajos publicados en revistas del SCI, en detrimento de los publicados en revistas españolas de calidad y de otras contribuciones científicas. Los resultados indican que el sistema de evaluación podría estar produciendo una discriminación entre los investigadores pertenecientes a distintos campos científicos, más que entre investigación básica y aplicada o entre investigación de interés local y/o nacional y aquella de ámbito internacional. Consideramos que el sistema de evaluación debe tener en cuenta la idiosincrasia y características propias y distintivas de cada campo científico y debe tomar en la adecuada consideración los trabajos de contrastada calidad que, por diversos motivos, no se publican en revistas del SCI, los cuales tienen una especial importancia en ciertos campos científicos, entre los que se encuentran las Ciencias de la Tierra

    Low-Voltage 0.81mW, 1-32 CMOS VGA with 5% Bandwidth variations and 38dB DC rejection

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    A CMOS low-voltage amplifier with approximately constant bandwidth and DC rejection is introduced. The design is based on the cascade of a wide linear input range OTA, an op-amp and a servo-loop with extremely large time constants. It operates with ±0.45V supplies and a power consumption of 0.81mW in 180nm technology. The bandwidth changes only from 9.08MHz to 9.54MHz over a gain range from 1 to 32, it has a 9.8Hz low cutoff frequency and a DC attenuation of 38dBs. DC floating voltage sources are used to keep the gates of all differential pairs at a constant value close to a supply rail in order to operate the amplifier circuit with minimum supply voltage. The proposed circuit has small and large signal figures of merit FOM SS = 5380 (MHz*pF/mW) and FOM LS = 0.0085((V/ns)*pF/mA) for a nominal gain A = 32

    Self-sufficient asymmetric reduction of β-ketoesters catalysed by a novel and robust thermophilic alcohol dehydrogenase co-immobilised with NADH

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    β-Hydroxyesters are essential building blocks utilised by the pharmaceutical and food industries in the synthesis of functional products. Beyond the conventional production methods based on chemical catalysis or whole-cell synthesis, the asymmetric reduction of β-ketoesters with cell-free enzymes is gaining relevance. To this end, a novel thermophilic (S)-3-hydroxybutyryl-CoA dehydrogenase from Thermus thermophilus HB27 (Tt27-HBDH) has been expressed, purified and biochemically characterised, determining its substrate specificity towards β-ketoesters and its dependence on NADH as a cofactor. The immobilization of Tt27-HBDH on agarose macroporous beads and its subsequent coating with polyethyleneimine has been found the best strategy to increase the stability and workability of the heterogeneous biocatalyst. Furthermore, we have embedded NADH in the cationic layer attached to the porous surface of the carrier. Since Tt27-HBDH catalyses cofactor recycling through 2-propanol oxidation, we achieve a self-sufficient heterogeneous biocatalyst where NADH is available for the immobilised enzymes but its lixiviation to the reaction bulk is avoided. Taking advantage of the autofluorescence of NADH, we demonstrate the activity of the enzyme towards the immobilised cofactor through single-particle analysis. Finally, we tested the operational stability in the asymmetric reduction of β-ketoesters in batch, succeeding in the reuse of both the enzyme and the co-immobilised cofactor up to 10 reaction cycles

    Encapsulated pine bark polyphenolic extract during gastrointestinal digestion: bioaccessibility, bioactivity and oxidative stress prevention

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    Polyphenolic extracts from pine bark have reported different biological actions and promising beneficial effects on human health. However, its susceptibility to environmental stresses (temperature, storage, etc.) and physiological human conditions prequires the development of efficient protection mechanisms to allow effective delivering of functionality. The aim of this work was to encapsulate pine bark extract rich phenolic compounds by spray-drying using maltodextrin, and understand the influence of encapsulation on the antioxidant and antimicrobial activity and bioaccessibility of phenolic compounds during gastrointestinal digestion. The optimized process conditions allowed good encapsulation efficiency of antioxidant phenolic compounds. The microencapsulation was effective in protecting those compounds during gastrointestinal conditions, controlling their delivery and enhancing its health benefits, decreasing the production of reactive oxygen species implicated in the process of oxidative stress associated with some pathologies. Finally, this encapsulation system was able to protect these extracts against acidic matrices, making the system suitable for the nutritional enrichment of fermented foods or fruit-based beverages, providing them antimicrobial protection, because the encapsulated extract was effective against Listeria innocua. Overall, the designed system allowed protecting and appropriately delivering the active compounds, and may find potential application as a natural preservative and/or antioxidant in food formulations or as bioactive ingredient with controlled delivery in pharmaceuticals or nutraceuticals.This research was funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020-Programa Operacional Regional do Norte. The study was also supported by program INTERREG V-B Sudoe (REDVALUE, SOE1/P1/E0123) and by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant (MSCARISE; FODIAC; 778388). P.F.-S. is supported by a doctoral advanced training fellowship (call NORTE69-2015-15), funded under the scope of Norte2020 (NORTE-08-5369-FSE-000036). R.I. thanks the University of Lleida for the UdL-Impuls post-doctoral contract.info:eu-repo/semantics/publishedVersio

    Fox : a un año de la alternancia

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    Reflexiones críticas desde diversas disciplinas de las ciencias sociales acerca del primer año de gobierno de Vicente Fox Quesada. Entre los rubros que se analizan están: la política cultural, el sector rural, los jóvenes, los derechos humanos, la cultura indígena y la seguridad pública.ITESO, A.C

    Reflexiones sobre los retos y oportunidades de la educación híbrida

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    3er Coloquio Fortalecimiento de los Colectivos de Docencia.Reconociendo que esta educación tiene características y metodologías pedagógicas diferentes a las presenciales, de cara al futuro hay que pensar en un formato híbrido que combine la noción presencial y la noción virtual de manera funcional. La modalidad actual funciona como respuesta a una emergencia, pero hay que desarrollar estrategias que sostengan este nuevo modelo en el mediano plazo. Integrantes del Colectivo de Docencia de Diseño Industrial del Departamento de Evaluación, nos reunimos en conferencia vía zoom, para discurrir sobre el tema. Algunas de las reflexiones se integran a la presentación en forma directa con el fin de evitar cualquier mala interpretación relacionada a las propuestas y sugerencias

    The SOPHIE search for northern extrasolar planets. V. Follow-up of ELODIE candidates: Jupiter-analogs around Sun-like stars

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    We present radial-velocity measurements obtained in a programs underway to search for extrasolar planets with the spectrograph SOPHIE at the 1.93-m telescope of the Haute-Provence Observatory. Targets were selected from catalogs observed with ELODIE, mounted previously at the telescope, in order to detect long-period planets with an extended database close to 15 years. Two new Jupiter-analog candidates are reported to orbit the bright stars HD150706 and HD222155 in 16.1 and 10.9 yr at 6.7 (+4.0,-1.4) and 5.1(+0.6,-0.7) AU and to have minimum masses of 2.71 (+1.44,-0.66) and 1.90 (+0.67,-0.53) M_Jup, respectively. Using the measurements from ELODIE and SOPHIE, we refine the parameters of the long-period planets HD154345b and HD89307b, and publish the first reliable orbit for HD24040b. This last companion has a minimum mass of 4.01 +/- 0.49 M_Jup orbiting its star in 10.0 yr at 4.92 +/- 0.38 AU. Moreover, the data provide evidence of a third bound object in the HD24040 system. With a surrounding dust debris disk, HD150706 is an active G0 dwarf for which we partially corrected the effect of the stellar spot on the SOPHIE radial-velocities. HD222155 is an inactive G2V star. On the basis of the previous findings of Lovis and collaborators and since no significant correlation between the radial-velocity variations and the activity index are found in the SOPHIE data, these variations are not expected to be only due to stellar magnetic cycles. Finally, we discuss the main properties of this new population of long-period Jupiter-mass planets, which for the moment, consists of fewer than 20 candidates. These stars are preferential targets either for direct-imaging or astrometry follow-up to constrain the system parameters and for higher precision radial-velocity to search for lower mass planets, aiming to find a Solar System twin.Comment: accepted for publication in Astronomy & Astrophysic

    Planck intermediate results. XXXVI. Optical identification and redshifts of Planck SZ sources with telescopes at the Canary Islands observatories

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    Catalogs and data.-- et al.We present the results of approximately three years of observations of Planck Sunyaev-Zeldovich (SZ) sources with telescopes at the Canary Islands observatories as part of the general optical follow-up programme undertaken by the Planck Collaboration. In total, 78 SZ sources are discussed. Deep-imaging observations were obtained for most of these sources; spectroscopic observations in either in long-slit or multi-object modes were obtained for many. We effectively used 37.5 clear nights. We found optical counterparts for 73 of the 78 candidates. This sample includes 53 spectroscopic redshift determinations, 20 of them obtained with a multi-object spectroscopic mode. The sample contains new redshifts for 27 Planck clusters that were not included in the first Planck SZ source catalogue (PSZ1).The Planck Collaboration acknowledges the support of: ESA; CNES, and CNRS/INSU-IN2P3-INP (France); ASI, CNR, and INAF (Italy); NASA and DoE (USA); STFC and UKSA (UK); CSIC, MINECO, JA and RES (Spain); Tekes, AoF, and CSC (Finland); DLR and MPG (Germany); CSA (Canada); DTU Space (Denmark); SER/SSO (Switzerland); RCN (Norway); SFI (Ireland); FCT/MCTES (Portugal); ERC and PRACE (EU). A.S., R.B., H.L., and J.A.R.M. acknowledge financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) under the 2011 Severo Ochoa Program MINECO SEV-2011-0187, and the Consolider-Ingenio project CSD2010-00064 (EPI: Exploring the Physics of Inflation).Peer Reviewe

    Planck Intermediate Results. IX. Detection of the Galactic haze with Planck

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    Using precise full-sky observations from Planck, and applying several methods of component separation, we identify and characterize the emission from the Galactic "haze" at microwave wavelengths. The haze is a distinct component of diffuse Galactic emission, roughly centered on the Galactic centre, and extends to |b| ~35 deg in Galactic latitude and |l| ~15 deg in longitude. By combining the Planck data with observations from the WMAP we are able to determine the spectrum of this emission to high accuracy, unhindered by the large systematic biases present in previous analyses. The derived spectrum is consistent with power-law emission with a spectral index of -2.55 +/- 0.05, thus excluding free-free emission as the source and instead favouring hard-spectrum synchrotron radiation from an electron population with a spectrum (number density per energy) dN/dE ~ E^-2.1. At Galactic latitudes |b|<30 deg, the microwave haze morphology is consistent with that of the Fermi gamma-ray "haze" or "bubbles," indicating that we have a multi-wavelength view of a distinct component of our Galaxy. Given both the very hard spectrum and the extended nature of the emission, it is highly unlikely that the haze electrons result from supernova shocks in the Galactic disk. Instead, a new mechanism for cosmic-ray acceleration in the centre of our Galaxy is implied.Comment: 15 pages, 9 figures, submitted to Astronomy and Astrophysic
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