2,979 research outputs found

    Radar-based nowcasting by combining centroid tracking and motion vector of convective storm

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    Póster presentado en: 3rd European Nowcasting Conference, celebrada en la sede central de AEMET en Madrid del 24 al 26 de abril de 2019

    Formation characteristics and photoluminescence of Ge nanocrystals in HfO[sub 2]

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    Genanocrystals (NCs) are shown to form within HfO₂ at relatively low annealing temperatures (600–700 °C) and to exhibit characteristic photoluminescence(PL) emission consistent with quantum confinement effects. After annealing at 600 °C, sample implanted with 8.4×10¹⁵ Ge cm⁻² show two major PL peaks, at 0.94 and 0.88 eV, which are attributed to no-phonon and transverse-optical phonon replica of Ge NCs, respectively. The intensity reaches a maximum for annealing temperatures around 700 °C and decreases at higher temperatures as the NC size continues to increase. The no-phonon emission also undergoes a significant redshift for temperatures above 800 °C. For fluences in the range from 8.4×1015 to 2.5×10¹⁶ cm⁻², the average NC size increases from ∼13.5±2.6 to ∼20.0±3.7 nm. These NC sizes are much larger than within amorphous SiO₂. Implanted Ge is shown to form Ge NCs within the matrix of monoclinic (m)-HfO₂ during thermal annealing with the orientation relationship of [101]m-HfO₂//[110]Ge NC.S.H.C. and R.G.E. acknowledge supports from the Korea Research Foundation Grant Grant No. KRF-2007-521- C00094 and from the Australian Research Council Discovery Project, respectively

    Massive transfusion protocol: the reason it is necessary

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    Objective. The purpose of this study is to identify problems of emergency transfusion at the bedside and to determine need for massive transfusion protocol. Methods. We included patients who met the criteria for “trauma team activation” and were admitted to division of trauma. The amount of blood product transfused in each unit was investigated for balanced transfusion. We also investigated the compliance with assessment of blood consumption score. The correlation between the time elapsed from patient visit to first transfusion order and time elapsed from first transfusion order to transfusion start was analyzed. Finally, we investigated various factors which serve to influence the decision-making process regarding early transfusion order. Results. Ratio of packed Red blood cells (pRBC): Fresh frozen plasma (FFP) was well-balanced, but platelet transfusion done was much lower than pRBC and FFP in emergency room. The application of emergency blood release did not match the criteria of assessment of blood consumption (ABC) score. The time from the first transfusion order to the transfusion start was found to be constant irrespective of time from patient visit to first transfusion order. And, the time from the first transfusion order to transfusion start did not differ significantly among patients with early transfusion order and delayed transfusion order. Only systolic blood pressure of < 90 mmHg was identified as a major predictor for early transfusion order. Conclusion. Balanced transfusion is not easy and emergency transfusion could be delayed at the bedside. Integrated and systematic structures for massive transfusion protocol would be invaluable and indispensable

    Imaging Findings of Adenocarcinoma Arising from Lingual Foregut Duplication Cyst

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    Lingual foregut duplication cysts are rare developmental anomalies with varied symptoms, and adenocarcinomas may develop from them. Radiological evaluations, including computed tomography and magnetic resonance imaging, can help diagnose these lesions and determine their extent. Abnormal enhancement should raise the suspicion of malignancy of a lingual foregut duplication cyst. Early detection and complete surgical resection of lingual foregut duplication cysts are necessary to prevent malignant transformations. Complete tumor resection with adjuvant radiotherapy or radiochemotherapy is recommended. The teaching point is that mucinous adenocarcinoma can develop from a lingual foregut duplication cyst, and radiological studies may aid in the diagnosis. Teaching Point: Adenocarcinomas can develop from lingual foregut duplication cysts, which are rare developmental anomalies, and radiologic studies may aid in the diagnosis

    Fabrication of graphene-based electrode in less than a minute through hybrid microwave annealing

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    Highly efficient and stable MoS 2 nanocrystals on graphene sheets (MoS 2 /GR) are synthesized via a hybrid microwave annealing process. Through only 45 second-irradiation using a household microwave oven equipped with a graphite susceptor, crystallization of MoS 2 and thermal reduction of graphene oxide into graphene are achieved, indicating that our synthetic method is ultrafast and energy-economic. Graphene plays a crucial role as an excellent microwave absorber as well as an ideal support material that mediates the growth of MoS 2 nanocrystals. The formed MoS 2 /GR electrocatalyst exhibits high activity of hydrogen evolution reaction with small onset overpotential of 0.1 V and Tafel slope of 50mV per decade together with an excellent stability in acid media. Thus our hybrid microwave annealing could be an efficient generic method to fabricate various graphene-based hybrid electric materials for broad applications.open2

    Normal stress difference-driven particle focusing in nanoparticle colloidal dispersion

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    Colloidal dispersion has elastic properties due to Brownian relaxation process. However, experimental evidence for the elastic properties, characterized with normal stress differences, is elusive in shearing colloidal dispersion, particularly at low Peclet numbers (Pe &lt; 1). Here, we report that single micrometer-sized polystyrene (PS) beads, suspended in silica nanoparticle dispersion (8 nm radius; 22%, v/v), laterally migrate and form a tightly focused stream by the normal stress differences, generated in pressure-driven microtube flow at low Pe. The nanoparticle dispersion was expected to behave as a Newtonian fluid because of its ultrashort relaxation time (2 mu s), but large shear strain experienced by the PS beads causes the notable non-Newtonian behavior. We demonstrate that the unique rheological properties of the nanoparticle dispersion generate the secondary flow in perpendicular to mainstream in a noncircular conduit, and the elastic properties of blood plasma-constituting protein solutions are elucidated by the colloidal dynamics of protein molecules

    Inactivation of Photosystem I in Cucumber Leaves Exposed to Paraquat-Induced Oxidative Stress

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    Cucumber leaves subjected to light chilling stress exhibit a preferential inactivation of photosystem (PS) I relative to PSII, resulting in the photoinhibition of photosynthesis. In light-chilled cucumber leaves, Cu/Zn-Superoxide dismutase (SOD) is regarded as a primary target of the light chilling stress and its inactivation is closely related to the increased production of reactive oxygen species. In the present study, we further explored that inactivation of PSI in cucumber leaves is not a light chilling specific, but general to various oxidative stresses. Oxidative stress in cucumber leaves was induced by treatment of methylviologen (MV), a producer of reactive oxygen species in chloroplasts. MV treatment decreased the maximal photosynthetic O 2 evolution, resulting in the photoinhibition of photosynthesis. The photoinhibition of photosynthesis was attributable to the decline in PSI functionality determined in vivo by monitoring absorption changes around 820 nm. In addition, MV treatment inactivated both antioxidant enzymes Cu/Zn-superoxide dismutase and ascorbate peroxidase known sensitive to reactive oxygen species. From these results, we suggest that chloroplast antioxidant enzymes are the primary targets of photooxidative stress, followed by subsequent inactivation of PSI

    Involvement of Heme Oxygenase-1 Induction in the Cytoprotective and Immunomodulatory Activities of Viola patrinii in Murine Hippocampal and Microglia Cells

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    A number of diseases that lead to injury of the central nervous system are caused by oxidative stress and inflammation in the brain. In this study, NNMBS275, consisting of the ethanol extract of Viola patrinii, showed potent antioxidative and anti-inflammatory activity in murine hippocampal HT22 cells and BV2 microglia. NNMBS275 increased cellular resistance to oxidative injury caused by glutamate-induced neurotoxicity and reactive oxygen species generation in HT22 cells. In addition, the anti-inflammatory effects of NNMBS275 were demonstrated by the suppression of proinflammatory mediators, including proinflammatory enzymes (inducible nitric oxide synthase and cyclooxygenase-2) and cytokines (tumor necrosis factor-α and interleukin-1β). Furthermore, we found that the neuroprotective and anti-inflammatory effects of NNMBS275 were linked to the upregulation of nuclear transcription factor-E2-related factor 2-dependent expression of heme oxygenase-1 in HT22 and BV2 cells. These results suggest that NNMBS275 possesses therapeutic potential against neurodegenerative diseases that are induced by oxidative stress and neuroinflammation

    Radiation exposure from computed tomography in blunt trauma patients

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    Introduction. Computed tomography (CT) has many diagnostic advantages, spurring growth in the number of CT examinations. As the use of CT increases, the potential for radiation-induced adverse effects has become an issue. The primary objective of this study was to assess the liberal use of CT induced radiation exposure in patients with multiple blunt traumas. The secondary objective was to investigate the factors affecting the estimated effective dose resulting from CTs unrelated to final diagnosis. Methods. Using data from our hospital information system, we selected patients assigned a trauma code, according to the Korean Standard Classification of Diseases, and with three or more body lesions assessed by CT at the same time in the emergency department. Each CT conducted was categorized into ‘CT related to the final diagnosis’ or ‘CT unrelated to final diagnosis’. The characteristics and estimated effective dose of CTs unrelated to the final diagnosis were analyzed. The factors affecting the estimated effective dose of CTs unrelated to final diagnosis were investigated. Results. More than half of all CT examinations were not associated with the final diagnosis. The additional estimated effective dose due to CTs being unrelated to the final diagnosis in each patient was a sufficient amount of radiation exposure to increase the possibility of fatal cancer. Conclusion. A considerable number of CT scans were unrelated to the patient’s final diagnosis, which exposes the patient to additional radiation exposure
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