884 research outputs found

    A rare case of xanthogranuloma of the stomach masquerading as an advanced stage tumor

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    <p>Abstract</p> <p>Background</p> <p>Xanthogranuloma of the stomach is an extremely rare disease, and this lesion has only been found to coexist with early gastric cancer in 2 cases in the literature.</p> <p>Case presentation</p> <p>We report a case of xanthogranuloma of the stomach combined with early gastric cancer that mimicked an advanced stage tumor. A 65-year-old female was referred to our hospital because of epigastralgia. During a physical examination, a defined abdominal mass was palpable in the region of the left hypochondrium. Imaging studies revealed an advanced gastric cancer, which was suspected of having infiltrated the abdominal wall. Total gastrectomy and resection of the regional lymph node and abdominal wall were performed. Histopathologic examination of the resected specimen demonstrated xanthogranuloma combined with early gastric cancer.</p> <p>Conclusion</p> <p>Xanthogranuloma presenting as a form of SMT (submucosal tumor) of the stomach is an extremely rare disease, and diagnosing it preoperatively is difficult. Further accumulation and investigation of this entity is necessary.</p

    First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

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    Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

    Vulnerabilidad climática de Puerto Iguazú, Argentina: Camino hacia la adaptación

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    Las ciudades ocupan un papel vital en el combate contra el cambio climático. Su importancia como actores esenciales se basa en el hecho de que concentran gran parte de la actividad económica y se espera que alberguen a dos terceras partes de la población del planeta para mediados de siglo. En este sentido, las acciones que las ciudades pueden realizar para enfrentar este desafío son significativas. Estas acciones incluyen esfuerzos para mitigar los efectos adversos del calentamiento global, así como gestiones para protegerse y adaptarse a eventos climáticos extremos, los cuales es probable que se tornen más intensos y frecuentes en un futuro. Hasta el momento, la atención se ha volcado predominantemente hacia las grandes metrópolis, dejando a un lado las ciudades medianas y pequeñas, las cuales a menudo son las que registran los niveles de crecimiento más altos y las que carecen de recursos de diversa índole para hacer frente a este desafío. Bajo este contexto, el presente artículo se enfoca a examinar la vulnerabilidad climática de Puerto Iguazú, una ciudad argentina situada en la llamada región de la "Triple Frontera", ya que comparte límites territoriales con Ciudad del Este (Paraguay) y Foz do Iguaçu (Brasil). El análisis se base en un enfoque de métodos mixtos. En términos cuantitativos, se desarrolló un Índice de Vulnerabilidad Urbana (IVU), el cual incluye 73 indicadores económicos, sociales, físicos, climáticos y ambientales, con el propósito de cuantificar la sensitividad de la ciudad a eventos climáticos extremos, así como su capacidad para responder y adaptarse. En términos cualitativos, información derivada de entrevistas fue utilizada para complementar los hallazgos. Este estudio forma parte de la iniciativa Ciudades Resilientes al Clima (CRC) en América Latina. El artículo, en este sentido, también hace una reflexión sobre la experiencia de conducir un proyecto bajo dicha iniciativa, y sobre las lecciones que estos resultados ofrecen a otras ciudades en contextos similares en América Latina

    All-sky search for periodic gravitational waves in the O1 LIGO data

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    We report on an all-sky search for periodic gravitational waves in the frequency band 20-475 Hz and with a frequency time derivative in the range of [-1.0,+0.1]×10-8 Hz/s. Such a signal could be produced by a nearby spinning and slightly nonaxisymmetric isolated neutron star in our galaxy. This search uses the data from Advanced LIGO\u27s first observational run, O1. No periodic gravitational wave signals were observed, and upper limits were placed on their strengths. The lowest upper limits on worst-case (linearly polarized) strain amplitude h0 are ∼4×10-25 near 170 Hz. For a circularly polarized source (most favorable orientation), the smallest upper limits obtained are ∼1.5×10-25. These upper limits refer to all sky locations and the entire range of frequency derivative values. For a population-averaged ensemble of sky locations and stellar orientations, the lowest upper limits obtained for the strain amplitude are ∼2.5×10-25
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