30 research outputs found

    Radio-Optically- and Thermally Stimulated Luminescence of Zn(BO2)2:Tb3+ exposed to Ionizing Radiation

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    The optical absorption of zinc tetraborate at different concentrations of the terbium impurity (0, 0.5, 1, 2, 4, 8 mol%) was analyzed. The radioluminescence (RL) emission spectra was obtained after beta irradiation of a 90Sr/90Y source. The RL spectrum showed the characteristics bands of Tb3+ with two main emissions at 489 nm and 546 nm which corresponding to the5D4→7F6 and 5D4→7F5 transitions respectively in this ion. The OSL and TL characteristics have been analyzed. The stimulation blue light (497 nm) of a diode laser at 500 mA was used to bleach the thermoluminescent (TL) signals obtained with 5Gy of 60Co source. The two main glow peaks (79 and 161 °C) are sensitives under 497 nm stimulation, and they were shifted to higher temperature values and faded their TL intensities. Similar behavior of TL glow curves before and after OSL stimulation with blue light was observed when the samples were exposed to 30 Gy gamma dose of 137Cs irradiator. The OSL signal response was linear with the dose range of 1-10 Gy and increased their response up to 200 Gy gamma dose. The OSL shows a bleaching sensitive shallow traps and diminishing the intensity of the TL glow curves remaining a complex traps distribution. The RL, TL and OSL properties were investigated in Zn(BO2)2:Tb3+ phosphor

    Neuropathic Pain in Dogs and Cats: Current Evaluation and Treatment Perspectives: Review

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    Abstract: During the past decade, the number of scientific papers on the recognition and multimodal management of pain in small animals increased exponentially. However, the variable of neuropathic pain, or adaptive disorder, has not yet been characterized completely. Its genesis is related to several diseases and injuries of the nervous system that change the neuroanatomical structures that participate in pain processing. Finding novel neurobiological mechanisms and the development of techniques for diagnosis and treatment in Human Medicine, are opening great opportunities for research and the understanding of neuropathic pain in pets

    A Performance Analysis Framework for WiFi/WiMAX Heterogeneous Metropolitan Networks Based on Cross-Layer Design

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    The communication between network nodes within different protocol domains is often regarded simply as a black box with unknown configuration conditions in the path. We address network heterogeneity using a white box approach and focus on its interconnection processes. To achieve this purpose, a Performance Analysis Framework (PAF) is proposed which is composed of the formalization of the latter using process algebra (PA) and the corresponding teletraffic performance models. In this contribution, we target the IEEE 802.16 and IEEE 802.11 protocols. For the teletraffic models, we extend previous models for such scenario with the inclusion of the following protocol operational parameters (metrics): bit error rate (BER), packet error ratio (PER), and packet length (pl). From the framework teletraffic models, the optimal packet length (OPL), end to end throughput, delay, and packet loss are obtained. The PAF outperforms previous modeling solutions in terms of delay and throughput relative to NS3 simulation results. </jats:p

    Polymer-Cement Mortar with Quarry Waste as Sand Replacement

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    The activities of carved Quarry extraction generate problems of landscape pollution such is the case of solid waste discharged into open land dumps in central Mexico. This article presents the technological application of this solid waste in a new polymeric material with properties similar to those of a traditional mortar. It is concluded that the polymeric material uses low amounts of cement with respect to the traditional mortar, and it is elaborated with the recycled quarry as they are presented in its granulometry. The polymer used favored a low water/cement ratio (0.3) which did not allow to decrease resistance due to the fine nature of the materials (residues and cement) in addition to maintaining the workability of the material. The quarry residue was classified as silt with low plasticity and was characterized by X-ray diffraction and Fluorescence to identify 76% of SiO2, which is why it was used as a stone aggregate even though the fines content was approximately 93%. The maximum compression resistance obtained at 28 days were 8 Mpa with the polymer/solid ratios of 0.10, water/solids of 0.30, and quarry/solids of 0.67. Linear equations were analyzed for more representative values with R squared adjustment

    P. brasiliensis virulence is affected by SconC, the negative regulator of inorganic sulfur assimilation

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    Conidia/mycelium-to-yeast transition of Paracoccidioidesbrasiliensis is a critical step for the establishment of paracoccidioidomycosis, a systemic mycosis endemic in Latin America. Thus, knowledge of the factors that mediate this transition is of major importance for the design of intervention strategies. So far, the only known pre-requisites for the accomplishment of the morphological transition are the temperature shift to 37°C and the availability of organic sulfur compounds. In this study, we investigated the auxotrophic nature to organic sulfur of the yeast phase of Paracoccidioides, with special attention to P. brasiliensis species. For this, we addressed the role of SconCp, the negative regulator of the inorganic sulfur assimilation pathway, in the dimorphism and virulence of this pathogen. We show that down-regulation of SCONC allows initial steps of mycelium-to-yeast transition in the absence of organic sulfur compounds, contrarily to the wild-type fungus that cannot undergo mycelium-to-yeast transition under such conditions. However, SCONC down-regulated transformants were unable to sustain yeast growth using inorganic sulfur compounds only. Moreover, pulses with inorganic sulfur in SCONC down-regulated transformants triggered an increase of the inorganic sulfur metabolism, which culminated in a drastic reduction of the ATP and NADPH cellular levels and in higher oxidative stress. Importantly, the down-regulation of SCONC resulted in a decreased virulence of P. brasiliensis, as validated in an in vivo model of infection. Overall, our findings shed light on the inability of P. brasiliensis yeast to rely on inorganic sulfur compounds, correlating its metabolism with cellular energy and redox imbalances. Furthermore, the data herein presented reveal SconCp as a novel virulence determinant of P. brasiliensis.J.F.M. and J.G.R. were supported by a PhD grant from Fundacao para a Ciencia e Tecnologia (FCT). This work was supported by a grant from FCT (PTDC/BIA-MIC/108309/2008). M. Sturme. and M. Saraiva are Ciencia 2008 fellows. The authors would also like to thank FAPESP (Fundacao para Amparo a Pesquisa do Estado de Sao Paulo) and CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico) for financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Role of CD45 Signaling Pathway in Galactoxylomannan-Induced T Cell Damage

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    Previously, we reported that Galactoxylomannan (GalXM) activates the extrinsic and intrinsic apoptotic pathways through an interaction with the glycoreceptors on T cells. In this study we establish the role of the glycoreceptor CD45 in GalXM-induced T cell apoptosis, using CD45+/+ and CD45−/− cell lines, derived from BW5147 murine T cell lymphoma. Our results show that whereas CD45 expression is not required for GalXM association by the cells, it is essential for apoptosis induction. In CD45+/+ cells, CD45 triggering by GalXM reduces the activation of Lck, ZAP70 and Erk1/2. Conversely, in CD45−/− cells, Lck was hyperphosphorylated and did not show any modulation after GalXM stimulation. On the whole, our findings provide evidence that the negative regulation of Lck activation occurs via CD45 engagement. This appears to be related to the capacity of GalXM to antagonize T cell activation and induce T cell death. Overall this mechanism may be responsible for the immune paralysis that follows GalXM administration and could explain the powerful immunosuppression that accompanies cryptococcosis

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

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    Use of anticoagulants and antiplatelet agents in stable outpatients with coronary artery disease and atrial fibrillation. International CLARIFY registry

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    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

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    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field
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