238 research outputs found

    Performance of a high T (sub c) superconducting ultra-low loss microwave stripline filter

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    Discussed here is the successful fabrication of a five-pole interdigital stripline filter made of the 93 K superconductor (Y1Ba2Cu3O sub y) coated on a silver substrate, with center frequency of 8.5 GHz and an extremely high rejection ratio of 80 dB. The lowest injection loss measured was 0.1 dB at 12 K, with a return loss of better than 16 dB, representing a significant improvement over a similar copper filter, and is comparable to low critical temperature filters. The insertion loss appears to be limited by extrinsic factors, such as tuning mismatch and joint losses, and not by superconducting material losses

    On 32-GHz cryogenically cooled HEMT low-noise amplifiers

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    The cryogenic noise temperature performance of a two-stage and a three-stage 32 GHz High Electron Mobility Transistor (HEMT) amplifier was evaluated. The amplifiers employ 0.25 micrometer conventional AlGaAs/GaAs HEMT devices, hybrid matching input and output microstrip circuits, and a cryogenically stable dc biasing network. The noise temperature measurements were performed in the frequency range of 31 to 33 GHz over a physical temperature range of 300 K down to 12 K. Across the measurement band, the amplifiers displayed a broadband response, and the noise temperature was observed to decrease by a factor of 10 in cooling from 300 K to 15 K. The lowest noise temperature measured for the two-stage amplifier at 32 GHz was 35 K with an associated gain of 16.5 dB, while the three-stage amplifier measured 39 K with an associated gain of 26 dB. It was further observed that both amplifiers were insensitive to light

    Perfil microbiológico y sensibilidad a antibióticos de microorganismos aislados de infecciones conjuntivales en el Instituto de Oftalmología Fundación Conde de Valenciana. Reporte del año 2012

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    ResumenIntroducciónLa conjuntiva es el tejido ocular que se infecta con mayor frecuencia. Los agentes patógenos más frecuentes de la conjuntivitis suelen ser los virus y las bacterias. El uso indiscriminado de antibióticos de amplio espectro para tratar la conjuntivitis ha generado microorganismos resistentes.ObjetivoIdentificar los microorganismos más frecuentes aislados de muestras de origen conjuntival y conocer su susceptibilidad antibiótica.Material y métodosRevisión retrospectiva de cultivos provenientes de raspados conjuntivales obtenidos durante el 2012.ResultadosSe obtuvieron 44 muestras de origen conjuntival. Estas provinieron de 21 varones y 23 mujeres. La mediana (25%, 75%) de la edad fue 62 años (39-68). El cultivo fue positivo en 13 de las muestras obtenidas, identificándose 5 microorganismos diferentes. Staphylococcus epidermidis fue el microorganismo aislado con mayor frecuencia (9 cepas). Todas las cepas de S. epidermidis fueron sensibles a vancomicina, gentamicina, cefotaxima, moxifloxacino y ofloxacino. La mayoría de las cepas de S. epidermidis (6/9) mostraron resistencia a múltiples antibióticos.ConclusionesStaphylococcus epidermidis fue el microorganismo aislado con mayor frecuencia en muestras provenientes de infecciones conjuntivales. Todas las cepas de S. epidermidis fueron sensibles a vancomicina, gentamicina y moxifloxacino y la mayoría de ellas fueron multirresistentes a los antibióticos en evaluación.AbstractIntroductionThe conjunctiva is the tissue of the eye that gets infected with more frequency. The most common pathogens of conjunctivitis are viruses and bacteria. The indiscriminate use of broad-spectrum antibiotics to treat conjunctivitis generated resistant microorganisms.ObjectiveIdentify the most common microorganisms isolated from samples of conjunctival origin and know their antibiotic susceptibility.Material and methodsRetrospective review of culture from conjunctival swabs obtained during 2012.ResultsWe collected 44 samples of conjunctival origin. They came from 21 males and 23 women. The median (25%, 75%) of age was 62 years (39-68). The culture was positive in 13 samples, identifying five different microorganisms. Staphylococcus epidermidis was the most common isolated microorganism (9 strains). All strains of S. epidermidis were sensitive to vancomycin, gentamicin, cefotaxime, ofloxacin and moxifloxacin. The multiple antibiotic resistance was identified in the majority of strains of S. epidermidis (6/9).ConclusionsStaphylococcus epidermidis was the most common isolated microorganism from samples of conjuntival infections. All strains of S. epidermidis were sensitive to vancomycin and moxifloxacin and most of them showed multidrug resistance to antibiotics

    Desarrollo de esmaltes vitrocerámicos con propiedades antideslizantes para baldosas de gres porcelánico

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    Ponència presentada a Qualicer 2008 - X World Congress on Ceramic Tile Quality, celebrat a Castelló (Spain) del 10 al 13 de febrer de 2008.La resistencia al deslizamiento es una prestación mecánica que se debe evaluar dentro de la selección de un pavimento cerámico, teniendo siempre en cuenta la aplicación a la cual será destinado. El aumento en el empleo de pavimentos cerámicos en locales de uso público, ambientes exteriores y/o húmedos, ha generado que el mercado demande, cada vez más, una elevada resistencia al deslizamiento como requisito básico de seguridad, del que se derivan requisitos de responsabilidad civil. Para tratar de solventar esta problemática, se han desarrollado esmaltes que permiten modificar el acabado superficial de los pavimentos, adecuando sus prestaciones de resistencia al deslizamiento a las exigencias establecidas para cualquier tipo de aplicación. Su efecto antideslizante ha sido originado en parte por la desvitrificación en el seno del esmalte vitrocerámico de fases cristalinas dentro del sistema cuaternario CaO – MgO – Al2O3 – SiO2. Tanto las fases desvitrificadas como la cantidad de cristales han sido estudiadas y controladas mediante DRX, SEM y ATD–TG. Una vez caracterizados los sistemas vitrocerámicos seleccionados, han sido aplicados en baldosas de gres y gres porcelánico por vía húmeda (serigrafías y barbotinas) y por vía seca (granillas) y se han determinado las propiedades superficiales de dichos sistemas

    Morphological, molecular and phylogenetic analyses of the spirurid nematode Stegophorus macronectes (Johnston & Mawson, 1942)

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    ©2015. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Accepted, version of a Published Work that appeared in final form in Journal of Helminthology. To access the final edited and published work see https://doi.org/10.1017/S0022149X15000218Stegophorus macronectes (Johnston & Mawson, 1942) is a gastrointestinal parasite found in Antarctic seabirds. The original description of the species, which was based only on females, is poor and fragmented with some unclear diagnostic characters. This study provides new morphometric and molecular data on this previously poorly described parasite. Nuclear rDNA sequences (18S, 5.8S, 28S and internal transcribed spacer (ITS) regions) were isolated from S. macronectes specimens collected from the chinstrap penguin Pygoscelis antarctica Forster on Deception Island, Antarctica. Using 18S rDNA sequences, phylogenetic analyses (maximum likelihood, maximum parsimony and Bayesian inference) of the order Spirurida were performed to determine the phylogenetic location of this species. Primer pairs of the ITS regions were designed for genus-level identification of specimens, regardless of their cycle, as an alternative to coprological methods. The utility of this molecular method for identification of morphologically altered specimens is also discussed

    The Latin American Consortium of Studies in Obesity (LASO)

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    Current, high-quality data are needed to evaluate the health impact of the epidemic of obesity in Latin America. The Latin American Consortium of Studies of Obesity (LASO) has been established, with the objectives of (i) Accurately estimating the prevalence of obesity and its distribution by sociodemographic characteristics; (ii) Identifying ethnic, socioeconomic and behavioural determinants of obesity; (iii) Estimating the association between various anthropometric indicators or obesity and major cardiovascular risk factors and (iv) Quantifying the validity of standard definitions of the various indexes of obesity in Latin American population. To achieve these objectives, LASO makes use of individual data from existing studies. To date, the LASO consortium includes data from 11 studies from eight countries (Argentina, Chile, Colombia, Costa Rica, Dominican Republic, Peru, Puerto Rico and Venezuela), including a total of 32 462 subjects. This article describes the overall organization of LASO, the individual studies involved and the overall strategy for data analysis. LASO will foster the development of collaborative obesity research among Latin American investigators. More important, results from LASO will be instrumental to inform health policies aiming to curtail the epidemic of obesity in the region

    New young planetary nebulae in IPHAS

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    Original article can be found at: http://www.aanda.org/ Copyright The European Southern Observatory. DOI: 10.1051/0004-6361/200811575Aims. We search for very small-diameter galactic planetary nebulae (PNe) representing the earliest phases of PN evolution. The IPHAS catalogue of H-emitting stars provides a useful basis for this study since all sources present in this catalogue must be of small angular diameter. Methods. The PN candidates are selected based on their location in two colour-colour diagrams: IPHAS (r' - H) vs. (r' - i'), and 2MASS (J - H) vs. (H - ). Spectroscopic follow-up was carried out on a sample of candidates to confirm their nature. Results. We present a total of 83 PN candidates. We were able to obtain spectra or find the classification from the literature for 35 candidates. Five of these objects are likely to be new PNe, including one large bipolar PN discovered serendipitously close to an emission-line star. PN distances deduced from extinction-distance relations based on IPHAS field-star photometry are presented for the first time. These yield distance estimates for our objects in the range 2 kpc and 6 kpc. From the data in hand, we conclude that four of the discovered objects are probably young PNe.Peer reviewe

    Medical imaging: Foundations and scope

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    Indexación: Scopus; Radalyc.En la actualidad es innegable la utilidad de las diversas modalidades de imagenología médica como apoyo clínico tanto en la generación de diagnósticos de un buen número de enfermedades como en la planeación de tratamientos tendientes a proporcionar una alternativa de solución a las personas que, por una u otra razón, manifiestan algún desequilibrio en su salud. Entre las modalidades imagenológicas que, frecuentemente, se utilizan en el ámbito médico se pueden mencionar: Ultrasonido (US), Resonancia Magnética (MRI), Tomografía Computarizada sencilla (CT) y multicapa (MSCT), Tomografía Computarizada por Emisión de Positrones (PET) y Tomografía Computarizada por Emisión de Fotones simples (SPECT). En este sentido, este artículo tiene como finalidad presentar una descripción ordenada, coherente y sistemática de cada una de las mencionadas modalidades y establecer la vinculación de la MSCT con situaciones clínicas íntimamente relacionadas con la anatomía cardiaca y procesos de hipertensión. La razón por la cual se hace énfasis en la MSCT es debido a que, por una parte, se cuenta con un número importante de bases de datos tanto de sujetos fisiológicos como de sujetos patológicos y, por la otra, que se tiene previsto presentar un conjunto de técnicas computacionales que serán exploradas en el desarrollo de futuras investigaciones en el contexto de aspectos anatómico-cardiológicos que influyen directa o indirectamente en la aparición, desarrollo y prevalencia de procesos hipertensivos.Nowdays, several forms of medical imaging are usefulness in clinical support for both diagnostics diseases generation and treatment planning designed to provide an alternative solution to people who, for one or another reason, manifest an imbalance in your health. Among the imaging modalities that frequently are used in the medical field may include: Ultrasound (US), magnetic resonance imaging (MRI), simple computed tomography (CT) and multilayer computed tomography (MSCT), CT positron emission tomography (PET) Computed tomography and single photon emission (SPECT). In this sense, this article presents an orderly, coherent and systematic description of these modalities and it establishes relationship with the MSCT modality and clinical situations closely related to cardiac anatomy and hypertension processes. The reason emphasis on MSCT is done is because, on the one hand, we have a large number of databases both physiological subjects and pathological subjects and, on the other, we plan to present a set of computational techniques that will be explored in future research, in the context of cardiologic anatomical aspects, with directly or indirectly influence in the emergence, development and prevalence of hypertensive processes.http://www.redalyc.org/articulo.oa?id=5594990700

    In silico Analyses of Immune System Protein Interactome Network, Single-Cell RNA Sequencing of Human Tissues, and Artificial Neural Networks Reveal Potential Therapeutic Targets for Drug Repurposing Against COVID-19

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    Background: There is pressing urgency to identify therapeutic targets and drugs that allow treating COVID-19 patients effectively.Methods: We performed in silico analyses of immune system protein interactome network, single-cell RNA sequencing of human tissues, and artificial neural networks to reveal potential therapeutic targets for drug repurposing against COVID-19.Results: We screened 1,584 high-confidence immune system proteins in ACE2 and TMPRSS2 co-expressing cells, finding 25 potential therapeutic targets significantly overexpressed in nasal goblet secretory cells, lung type II pneumocytes, and ileal absorptive enterocytes of patients with several immunopathologies. Then, we performed fully connected deep neural networks to find the best multitask classification model to predict the activity of 10,672 drugs, obtaining several approved drugs, compounds under investigation, and experimental compounds with the highest area under the receiver operating characteristics.Conclusion: After being effectively analyzed in clinical trials, these drugs can be considered for treatment of severe COVID-19 patients. Scripts can be downloaded at

    Código Cáncer: resultados preliminares

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    Antecedentes: Los retrasos en la atención de personas con cáncer impactan negativamente su calidad de vida y aumentan los costos al sistema de salud. / Objetivo: Describir las fases del proyecto Código Cáncer y sus resultados preliminares. / Métodos: Se organizaron siete grupos de investigación para: a) entender las causas de los retrasos que enfrentan las personas con cáncer en México, sus trayectorias y costos asociados; b) conocer los mecanismos de referencia formales e informales que constituyen su trayectoria en el sistema de salud, y c) entender la infraestructura existente y la necesaria para responder a las necesidades epidemiológicas del país. / Resultados: Estos resultados sientan las bases para la implementación de un programa de referencia rápida de pacientes. / Conclusión: Las políticas de diagnóstico y tratamiento oportuno del cáncer basadas en la evidencia son imprescindibles para atender los retrasos en la atención. Código Cáncer representa un proyecto innovador para lograr este objetivo en México
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