373 research outputs found

    Mantle dynamics of the Andean Subduction Zone from continent-scale teleseismic S-wave tomography

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    The Andean Subduction Zone is one of the longest continuous subduction zones on Earth. The relative simplicity of the two-plate system has makes it an ideal natural laboratory to study the dynamics in subduction zones. We measure teleseismic S and SKS traveltime residuals at >1000 seismic stations that have been deployed across South America over the last 30 yr to produce a finite-frequency teleseismic S-wave tomography model of the mantle beneath the Andean Subduction Zone related to the Nazca Plate, spanning from ~5°N to 45°S and from depths of ~130 to 1200 km. Within our model, the subducted Nazca slab is imaged as a fast velocity seismic anomaly. The geometry and amplitude of the Nazca slab anomaly varies along the margin while the slab anomaly continues into the lower mantle along the entirety of the subduction margin. Beneath northern Brazil, the Nazca slab appears to stagnate at ~1000 km depth and extend eastward subhorizontally for >2000 km. South of 25°S the slab anomaly in the lower mantle extends offshore of eastern Argentina, hence we do not image if a similar stagnation occurs. We image several distinct features surrounding the slab including two vertically oriented slow seismic velocity anomalies: one beneath the Peruvian flat slab and the other beneath the Paraná Basin of Brazil. The presence of the latter anomaly directly adjacent to the stagnant Nazca slab suggests that the plume, known as the Paraná Plume, may be a focused upwelling formed in response to slab stagnation in the lower mantle. Additionally, we image a high amplitude fast seismic velocity anomaly beneath the Chile trench at the latitude of the Sierras Pampeanas which extends from ~400 to ~1000 km depth. This anomaly may be the remnants of an older, detached slab, however its relationship with the Nazca-South America subduction zone remains enigmatic.Fil: Rodríguez, Emily E.. University of Arizona; Estados UnidosFil: Portner, Daniel Evan. No especifíca;Fil: Beck, Susan L.. University of Arizona; Estados UnidosFil: Rocha, Marcelo P.. Universidade do Brasília; BrasilFil: Bianchi, Marcelo B.. Universidade de Sao Paulo; BrasilFil: Assumpção, Marcelo. Universidade de Sao Paulo; BrasilFil: Ruiz, Mario. Escuela Politécnica Nacional; EcuadorFil: Alvarado, Patricia Monica. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Geofísica y Astronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Condori, Cristobal. Universidade do Brasília; BrasilFil: Lynner, Colton. University Of Delaware; Estados Unido

    BAJA INCIDENCIA DE PATOLOGIA ENDOMETRIAL EN MUJERES POSTMENOPAUSICAS CON SANGRADO ANORMAL QUE RECIBEN TERAPIA DE REEMPLAZO HORMONAL

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    Se realiza un estudio para analizar la frecuencia de patología endometrial en mujeres posmenopáusicas sanas con sangrado uterino anormal bajo terapia de reemplazo hormonal (TRH). Se estudiaron 104 mujeres posmenopáusicas que presentaron sangrado uterino anormal (irregular o excesivo) durante TRH con estrógenos y progesterona en diferentes esquemas (57% secuencial continuo; 31% combinado continuo; 12% secuencial discontinuo. A todas las pacientes se les realizó una biopsia ambulatoria aspirativa de endometrio. El procedimiento fue bien tolerado y no se observaron complicaciones hemorrágicas o infecciosas. Los resultados histológicos fueron los siguientes: endometrio secretor 38,5%; endometrio proliferativo 25%; endometrio atrófico 11,5%; hierplasia endometrial sin atipias 4,8%; pólipo endometrial benigno 2,9%; tejido endometrial benigno, inactivo o fragmentos de epitelio 11,5%; adenocarcinoma de endometrio 1% y ausencia de tejido endometrial 4,8%. La biopsia aspirativa de endometrio permitió conocer la situación endometrial en alrededor del 95% de las pacientes. Muestra insuficiente para diagnóstico se obtuvo en un 5% de los casos sugiriendo atrofia endometrial o patología focal no diagnosticada por el método. La ausencia de lesiones premalignas y la baja incidencia de patología maligna de endometrio en nuestro estudio confirman su baja incidencia en mujeres que reciben esquemas adecuados de terapia de reemplazo hromona

    Oestradiol-17β plasma concentrations after intramuscular injection of oestradiol benzoate or oestradiol cypionate in llamas (Lama glama)

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    <p>Abstract</p> <p>Background</p> <p>Llamas (<it>Lama glama</it>) are induced ovulators and the process of ovulation depends on dominant follicular size. In addition, a close relationship between behavioural estrus and ovulation is not registered in llamas. Therefore, the exogenous control of follicular development with hormones aims to predict the optimal time to mate. Oestradiol-17β (E<sub>2</sub>) and its esters are currently used in domestic species, including camelids, in synchronization treatments. But, in llamas, there is no reports regarding the appropriate dosages to be used and most protocols have been designed by extrapolation from those recommended for other ruminants. The aim of the present study was to characterize plasma E<sub>2 </sub>concentrations in intact female llamas following a single intramuscular (i.m.) injection of two oestradiol esters: oestradiol benzoate (EB) and oestradiol cypionate (ECP).</p> <p>Methods</p> <p>Twelve non pregnant and non lactating sexually mature llamas were i.m. injected on day 0 with 2.5 mg of EB (EB group, n = 6) or ECP (ECP group, n = 6). Blood samples were collected immediately before injection, at 1, 6, 12, 24 h after treatment and then daily until day 14 post injection. Changes in hormone concentrations with time were analyzed in each group by analysis of variance (ANOVA) using a repeated measures (within-SS) design. Plasma E<sub>2 </sub>concentrations and area under the concentration-time curve (AUC) values were compared between groups by ANOVA. In all cases a Least-Significant Difference test (LSD) was used to determine differences between means. Hormonal and AUC data are expressed as mean ± S.E.M.</p> <p>Results</p> <p>Peak plasma E<sub>2 </sub>concentrations were achieved earlier and were higher in EB group than in ECP group. Thereafter, E<sub>2 </sub>returned to physiological concentrations earlier in EB group (day 5) than in ECP group (day 9). Although plasma E<sub>2 </sub>profiles differed over time among groups there were no differences between them on AUC values.</p> <p>Conclusions</p> <p>The i.m. injection of a single dose of both oestradiol esters resulted in plasma E<sub>2 </sub>concentrations exceeding physiological values for a variable period. Moreover, the plasma E<sub>2 </sub>profiles observed depended on the derivative of oestradiol administered. This basic information becomes relevant at defining treatment protocols including oestrogens in llamas.</p

    Contactless doping characterization of Ga_2O_3 using acceptor Cd probes

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    Finding suitable p-type dopants, as well as reliable doping and characterization methods for the emerging wide bandgap semiconductor beta-Ga_2O_3 could strongly influence and contribute to the development of the next generation of power electronics. In this work, we combine easily accessible ion implantation, diffusion and nuclear transmutation methods to properly incorporate the Cd dopant into the beta-Ga_2O_3 lattice, being subsequently characterized at the atomic scale with the Perturbed Angular Correlation (PAC) technique and Density Functional Theory (DFT) simulations. The acceptor character of Cd in beta-Ga_2O_3 is demonstrated, with Cd sitting in the octahedral Ga site having a negative charge state, showing no evidence of polaron deformations nor extra point defects nearby. The possibility to determine the charge state of Cd will allow assessing the doping type, in particular proving p-type character, without the need for ohmic contacts. Furthermore, a possible approach for contactless charge mobility studies is demonstrated, revealing thermally activated free electrons for temperatures above similar to 648 K with an activation energy of 0.54(1) and local electron transport dominated by a tunneling process between defect levels and the Cd probes at lower temperatures

    CK2 Phosphorylation of Schistosoma mansoni HMGB1 Protein Regulates Its Cellular Traffic and Secretion but Not Its DNA Transactions

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    parasite resides in mesenteric veins where fecundated female worms lay hundred of eggs daily. Some of the egg antigens are trapped in the liver and induce a vigorous granulomatous response. High Mobility Group Box 1 (HMGB1), a nuclear factor, can also be secreted and act as a cytokine. Schistosome HMGB1 (SmHMGB1) is secreted by the eggs and stimulate the production of key cytokines involved in the pathology of schistosomiasis. Thus, understanding the mechanism of SmHMGB1 release becomes mandatory. Here, we addressed the question of how the nuclear SmHMGB1 can reach the extracellular space. eggs of infected animals and that SmHMGB1 that were localized in the periovular schistosomotic granuloma were phosphorylated.We showed that secretion of SmHMGB1 is regulated by phosphorylation. Moreover, our results suggest that egg-secreted SmHMGB1 may represent a new egg antigen. Therefore, the identification of drugs that specifically target phosphorylation of SmHMGB1 might block its secretion and interfere with the pathogenesis of schistosomiasis

    Low prevalence of renal, cardiac, pulmonary, and neurological extra-articular clinical manifestations in spondyloarthritis: analysis of the Brazilian Registry of Spondyloarthritis

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    OBJECTIVE: To describe the extra-articular manifestations (cardiac, renal, pulmonary, and neurological), usually not related to spondyloarthritis (SpA), in a large cohort of Brazilian patients. MATERIALS AND METHODS: This retrospective study analyzed 1,472 patients diagnosed with SpA and cared for at 29 health care centers distributed in the five major geographic regions in the country, participating in the Brazilian Registry of Spondyloarthritis (BRS). All patients were assessed for the prevalence of major extra-articular manifestations (cardiac, renal, pulmonary, and neurological), classified according to the diagnosis [ankylosing spondylitis (AS), psoriatic arthritis (PsA), reactive arthritis (ReA), arthritis associated with inflammatory bowel disease (IBD), undifferentiated spondyloarthritis (uSpA), and juvenile SpA], and according to the clinical presentation (axial, peripheral, mixed, and enthesitis). RESULTS: Of the patients with SpA assessed, 963 had AS, 271 PsA, 49 ReA, 48 arthritis associated with IBD, 98 uSpA, and 43 juvenile SpA. Cardiac involvement was reported in 44 patients (3.0%), pulmonary involvement in 19 (1.3%), renal involvement in 17 (1.2%), and neurological involvement in 13 patients (0.9%). Most patients with visceral involvement had AS or PsA, and the mixed (axial + peripheral) and/or predominantly axial clinical form. CONCLUSION: Cardiac, renal, pulmonary, and neurological extra-articular manifestations are quite infrequent in SpA, ranging from 0.9% to 3% in this large Brazilian cohort, and affected predominantly patients with AS and PsA.OBJETIVO: Descrever as manifestações extra-articulares (cardíacas, renais, pulmonares e neurológicas) geralmente não relacionadas às espondiloartrites (EpA) em uma grande coorte de pacientes brasileiros. MÉTODOS: Este estudo retrospectivo analisou 1.472 pacientes com o diagnóstico de EpA atendidos em 29 centros distribuídos pelas cinco principais regiões geográficas do Brasil, integrantes do Registro Brasileiro de Espondiloartrites. Todos os pacientes foram avaliados para a prevalência das principais manifestações extra-articulares (cardíacas, renais, pulmonares e neurológicas), divididas por diagnóstico [espondilite anquilosante (EA), artrite psoriásica (AP), artrite reativa (ARe), artrite associada a doença inflamatória intestinal (DII), EpA indiferenciada (EI) e EpA juvenil] e por forma clínica (axial, periférica, mista e entesítica). RESULTADOS: Dentre os pacientes avaliados com EpA, 963 apresentavam EA, 271 AP, 49 ARe, 48 artrite associada a DII, 98 EI e 43 EpA juvenil. Acometimento cardíaco foi observado em 44 pacientes (3,0%), seguido por acometimento pulmonar em 19 (1,3%), renal em 17 (1,2%) e neurológico em 13 pacientes (0,9%). A maioria dos casos de acometimento visceral ocorreu nos pacientes com EA ou AP e naqueles com forma clínica mista (axial e periférica) e/ou predominantemente axial. CONCLUSÃO: As manifestações extra-articulares cardíacas, renais, pulmonares e neurológicas são muito pouco frequentes nas EpA, variando de 0,9%-3% nesta grande coorte brasileira, estando mais associadas a EA e AP.37938

    Quality of life in spondyloarthritis : analysis of a large Brazilian cohort

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    Objetivo: analisar as variáveis demográficas e clínicas associadas à diminuição da qualidade de vida em uma grande coorte brasileira de pacientes com espondiloartrite (EpA). Métodos: Foi aplicado um protocolo de pesquisa único a 1.465 pacientes brasileiros classificados como tendo EpA de acordo com os critérios do European Spondyloarthropaties Study Group (ESSG), atendidos em 29 centros de referência em reumatologia do Brasil. Foram registradas as variáveis clínicas e demográficas. A qualidade de vida foi analisada por meio do questionário Ankylosing Spondylitis Quality of Life (ASQoL). Resultados: A pontuação média do ASQoL foi de 7,74 (+ 5,39). Ao analisar doenças específicas no grupo de EpA, as pontuações do ASQoL não apresentaram diferença estatisticamente significativa. Os dados demográficos mostraram piores escores de ASQoL associados ao gênero feminino (p = 0,014) e etnia negra (p < 0,001). Quanto aos sintomas clínicos, a dor na região glútea (p = 0,032), a dor cervical (p < 0,001) e a dor no quadril (p = 0,001), estiveram estatisticamente associadas a piores escores no ASQoL. O uso contínuo de fármacos anti-inflamatórios não esteroides (p < 0,001) e agentes biológicos (p = 0,044) esteve associado a escores mais elevados de ASQoL, enquanto outros medicamentos não interferiram nos escores do ASQoL. Conclusão: Nesta grande série de pacientes com EpA, o sexo feminino e a etnia negra, bem como sintomas predominantemente axiais, estiveram associados a uma qualidade de vida reduzida.Objective: to analyze quality of life and demographic and clinical variables associated to its impairment in a large Brazilian cohort of patients with spondyloarthritis (SpA). Methods: A common protocol of investigation was applied to 1465 Brazilian patients classified as SpA according to the European Spondyloarthropaties Study Group (ESSG) criteria, attended at 29 reference centers for Rheumatology in Brazil. Clinical and demographic variables were recorded. Quality of life was analyzed through the Ankylosing Spondylitis Quality of Life (ASQoL) questionnaire. Results: The mean ASQoL score was 7.74 (± 5.39). When analyzing the specific diseases in the SpA group, the ASQoL scores did not present statistical significance. Demographic data showed worse scores of ASQoL associated with female gender (p = 0.014) and African-Brazilian ethnicity (p < 0.001). Regarding clinical symptoms, buttock pain (p = 0.032), cervical pain (p < 0.001) and hip pain (p = 0.001), were statistically associated with worse scores of ASQoL. Continuous use of nonsteroidal anti-inflammatory drugs (p < 0.001) and biologic agents (p = 0.044) were associated with higher scores of ASQoL, while the other medications did not interfere with the ASQoL scores. Conclusion: In this large series of patients with SpA, female gender and African-Brazilian ethnicity, as well as predominant axial symptoms, were associated with impaired quality of life
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