2,581 research outputs found

    Isolated cutaneous Rosai-Dorfman disease: a case report

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    Background:Rosai-Dorfman also known as sinus histiocytosis with massive lymphadenopathy is a benign, idiopathic lymphoproliferative disorder that usually affects the lymph nodes. Cutaneous Rosai-Dorfman disease is a rare extranodal variant that occurs as histiocyte-rich inflammatory infiltrates, manifesting with a variable clinical morphology. Usually it appears as erythematous to brown papules, plaques, or nodules, with no predilection for site. The histological picture shows abnormal lymph node architecture, reactive germinal centers, fibrosis and emperipolesis in the dermis. On immunophenotypic analysis, S100 protein and CD68 are usually present on dendritic cells. Case Report: We report a case of purely cutaneous Rosai-Dorfman disease. A 55-year-old male presented to our clinic for an indurated nodule on the left malar region. He reported a slow and progressive growth of 2-year history without systemic symptoms. A cutaneous biopsy showed a nodular inflammatory infiltrate within the dermis consisting of histiocytes, local aggregates of plasma cells and lymphocytes. Histiocytes were enlarged with vesicular nuclei, and emperipolesis was observed. Furthermore, histiocytes stained positively for S-100 and CD68. Owing to local involvement, the patient received a surgery to exsect the lesion completely. Conclusions: Sinus histiocytosis is a rare inflammatory disease mainly affecting the cervical lymph nodes, presenting with skin lesions in 10% of cases. The diagnosis of cutaneous RDD is differentiated from other histiocytic conditions by the combination of clinical findings accompanied by histopathologic and immunohistochemical confirmationUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Methods for estimating the size of Google Scholar

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    The emergence of academic search engines (mainly Google Scholar and Microsoft Academic Search) that aspire to index the entirety of current academic knowledge has revived and increased interest in the size of the academic web. The main objective of this paper is to propose various methods to estimate the current size (number of indexed documents) of Google Scholar (May 2014) and to determine its validity, precision and reliability. To do this, we present, apply and discuss three empirical methods: an external estimate based on empirical studies of Google Scholar coverage, and two internal estimate methods based on direct, empty and absurd queries, respectively. The results, despite providing disparate values, place the estimated size of Google Scholar at around 160 to 165 million documents. However, all the methods show considerable limitations and uncertainties due to inconsistencies in the Google Scholar search functionalities.Comment: 22 pages, 4 figures and 6 tables. arXiv admin note: text overlap with arXiv:1407.623

    Active Temporal Multiplexing of Photons

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    Photonic qubits constitute a leading platform to disruptive quantum technologies due to their unique low-noise properties. The cost of the photonic approach is the non-deterministic nature of many of the processes, including single-photon generation, which arises from parametric sources and negligible interaction between photons. Active temporal multiplexing - repeating a generation process in time and rerouting to single modes using an optical switching network - is a promising approach to overcome this challenge and will likely be essential for large-scale applications with greatly reduced resource complexity and system sizes. Requirements include the precise synchronization of a system of low-loss switches, delay lines, fast photon detectors, and feed-forward. Here we demonstrate temporal multiplexing of 8 'bins' from a double-passed heralded photon source and observe an increase in the heralding and heralded photon rates. This system points the way to harnessing temporal multiplexing in quantum technologies, from single-photon sources to large-scale computation.Comment: Minor revision

    Web 2.0 en Topografía, Cartografía y Fotogrametría

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    La metodología 2.0 que desarrollamos se basa en la colaboración, compartiendo y trabajando en grupo, con la revisión permanente del entorno de enseñanza-aprendizaje en el ámbito de la Tecnologías de la Información Geográfica

    On the difference of torus geometry between hidden and non-hidden broad line active galactic nuclei

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    We present results from the fitting of infrared (IR) spectral energy distributions of 21 active galactic nuclei (AGN) with clumpy torus models. We compiled high spatial resolution (0.3\sim 0.3--0.70.7 arcsec) mid-IR NN-band spectroscopy, QQ-band imaging and nuclear near- and mid-IR photometry from the literature. Combining these nuclear near- and mid-IR observations, far-IR photometry and clumpy torus models, enables us to put constraints on the torus properties and geometry. We divide the sample into three types according to the broad line region (BLR) properties; type-1s, type-2s with scattered or hidden broad line region (HBLR) previously observed, and type-2s without any published HBLR signature (NHBLR). Comparing the torus model parameters gives us the first quantitative torus geometrical view for each subgroup. We find that NHBLR AGN have smaller torus opening angles and larger covering factors than those of HBLR AGN. This suggests that the chance to observe scattered (polarized) flux from the BLR in NHBLR could be reduced by the dual effects of (a) less scattering medium due to the reduced scattering volume given the small torus opening angle and (b) the increased torus obscuration between the observer and the scattering region. These effects give a reasonable explanation for the lack of observed HBLR in some type-2 AGN.Comment: 13 pages, 5 figures, accepted for publication in Ap

    Cross-talk between the RcsCDB and RstAB systems to control STM1485 gene expression in Salmonella Typhimurium during acid-resistance response

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    Bacterial survive and respond to adverse changes in the environment by regulating gene transcription through two-component regulatory systems. In Salmonella Typhimurium the STM1485 gene expression is induced under low pH (4.5) during replication inside the epithelial host cell, but it is not involved in sensing or resisting to this condition. Since the RcsCDB system is activated under acidic conditions, we investigated whether this system is able to modulate STM1485 expression. We demonstrated that acid-induced activation of the RcsB represses STM1485 transcription by directly binding to the promoter. Under the same condition, the RstA regulator activates the expression of this gene. Physiologically, we observed that RcsB-dependent repression is required for the survival of bacteria when they are exposed to pancreatic fluids. We hypothesized that STM1485 plays an important role in Salmonella adaptation to pH changes, during transition in the gastrointestinal tract. We suggest that bacteria surviving the gastrointestinal environment invade the epithelial cells, where they can remain in vacuoles. In this new environment, acidity and magnesium starvation activate the expression of the RstA regulator in a PhoPQ-dependent manner, which in turn induces STM1485 expression. These levels of STM1485 allow increased bacterial replication within vacuoles to continue the course of infection.Fil: Torrez Lamberti, Monica Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Biológica; ArgentinaFil: Farizano, Juan Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Biológica; ArgentinaFil: Lopez, Fabian Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Biológica; Argentina. Universidad Nacional de Chilecito; ArgentinaFil: Martinez Zamora, Martin Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Biológica; ArgentinaFil: Pescaretti, María de Las Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Biológica; ArgentinaFil: Táquez Delgado, Mónica Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Biológica; Argentin
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