133 research outputs found
Effects of Coronal Density and Magnetic Field Distributions on a Global Solar EUV Wave
We investigate a global extreme-ultraviolet (EUV) wave associated with a
coronal mass ejection (CME)-driven shock on 2017 September 10. The EUV wave is
transmitted by north- and south-polar coronal holes (CHs), which is observed by
the Solar Dynamics Observatory (SDO) and Solar Terrestrial Relations
Observatory A (STEREO-A) from opposite sides of the Sun. We obtain key findings
on how the EUV wave interacts with multiple coronal structures, and on its
connection with the CME-driven shock: (1) the transmitted EUV wave is still
connected with the shock that is incurvated to the Sun, after the shock has
reached the opposite side of the eruption; (2) the south CH transmitted EUV
wave is accelerated inside an on-disk, low-density region with closed magnetic
fields, which implies that an EUV wave can be accelerated in both open and
closed magnetic field regions; (3) part of the primary EUV wavefront turns
around a bright point (BP) with a bipolar magnetic structure when it approaches
a dim, low-density filament channel near the BP; (4) the primary EUV wave is
diffused and apparently halted near the boundaries of remote active regions
(ARs) that are far from the eruption, and no obvious AR related secondary waves
are detected; (5) the EUV wave extends to an unprecedented scale of ~360{\deg}
in latitudes, which is attributed to the polar CH transmission. These results
provide insights into the effects of coronal density and magnetic field
distributions on the evolution of an EUV wave, and into the connection between
the EUV wave and the associated CME-driven shock.Comment: 16 pages, 8 figures, and 3 animations available at
http://doi.org/10.13140/RG.2.2.12408.29442 ,
http://doi.org/10.13140/RG.2.2.25830.06723 , and
http://doi.org/10.13140/RG.2.2.19119.18088 ; published in Ap
A nonlinear dynamic model of fiber-reinforced composite thin plate with temperature dependence in thermal environment
Modeling of the nonlinear dynamic degradation characteristics of fiber-reinforced composite thin plates in thermal environment
A new nonlinear vibration model of fiber-reinforced composite thin plate with amplitude-dependent property
A new nonlinear vibration model of fiber-reinforced composite thin plate with amplitude-dependent property
Collaborative Technology
Ken Koltun-Fromm and Miriam Pallant
Handing technology off to students distances their education from the more vibrant, co-creative process of active learning in the classroom. But when students and teachers engage technology collaboratively, a sense of communal involvement and commitment energizes the learning environment and produces strong pedagogical results. For this presentation, we offer various strategies and concrete examples of our collaborative involvements with technology in the classroom: deploying iPads for active student content creation, using TEI markup software to develop close reading skills, and creating a visual syllabus with Prezi as a final student paper. Each of these projects involve close teacher/student and student/student collaborations, advancing pedagogical strategies and cultivating student interactive engagement. But each technology has its limitations, and requires creatively adapting classroom use to fit designed learning goals. When students fail to understand the value and benefit of the technological medium, they tend to disengage from and so drastically alter the learning process. Collaborative technology is an active, pedagogical process that develops a more egalitarian classroom: leveling the playing field, as it were, by fostering collaboration among verbal students and those less inclined to participate in more traditional ways. Students learn from and with each other in a communal, engaged learning environment
Visual and fluorogenic detection of a nerve agent simulant via a Lossen rearrangement of rhodamine-hydroxamate
A visual and fluorogenic detection method for a nerve agent simulant was developed based on a Lossen rearrangement of rhodamine-hydroxamate, in the presence of diethyl chlorophosphate, under alkaline conditions.Molecular Cloning Laboratories (South San Francisco, CA) ; National Natural Science Foundation of China [20802060
Trimetazidine Attenuates Cardiac Dysfunction in Endotoxemia and Sepsis by Promoting Neutrophil Migration
Aims: Cardiac dysfunction can be a fatal complication during severe sepsis. The migration of neutrophils is significantly impaired during severe sepsis. We sought to determine the role of trimetazidine (TMZ) in regulation of neutrophil migration to the heart in a mouse model of sepsis and endotoxemia, and to identify the mechanism whereby TMZ confers a survival advantage.Methods and Results: C57/BL6 mice were (1) injected with LPS followed by 24-h TMZ administration, or (2) treated with TMZ (20 mg/kg/day) for 1 week post cecal ligation and puncture (CLP) operation. Echocardiography and Millar system detection showed that TMZ alleviated cardiac dysfunction and histological staining showed the failure of neutrophils migration to heart in both LPS- and CLP-induced mice. Bone marrow transplantation revealed that TMZ-pretreated bone marrow cells improved LPS- and CLP-induced myocardial dysfunction and enhanced neutrophil recruitment in heart. In CXCL2-mediated chemotaxis assays, TMZ increased neutrophils migration via AMPK/Nrf2-dependent up-regulation of CXCR2 and inhibition of GRK2. Furthermore, using luciferase reporter gene and chromatin immunoprecipitation assays, we found that TMZ promoted the binding of the Nrf2 and CXCR2 promoter regions directly. Application of CXCR2 inhibitor completely reversed the protective effects of TMZ in vivo. Co-culture of neutrophils and cardiomyocytes further validated that TMZ decreased LPS-induced cardiomyocyte pyroptosis by targeting neutrophils.Conclusion: Our findings suggested TMZ as a potential therapeutic agent for septic or endotoxemia associated cardiac dysfunction in mice.STUDY HIGHLIGHTSÂ What is the current knowledge on the topic?Migration of neutrophils is significantly impaired during severe sepsis, but the underlying mechanisms remain unknown.What question did this study address?The effects of TMZ on cardiac dysfunction via neutrophils migration.What this study adds to our knowledgeTMZ attenuated LPS-induced cardiomyocyte pyroptosis and cardiac dysfunction by promoting neutrophils recruitment to the heart tissues via CXCR2.How this might change clinical pharmacology or translational scienceOur findings suggested TMZ as a potential therapeutic agent for septic cardiac dysfunction
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