2,581 research outputs found
Isolated cutaneous Rosai-Dorfman disease: a case report
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
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
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
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
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 (-- arcsec) mid-IR -band
spectroscopy, -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
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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