55 research outputs found

    Down-modulation of endoplasmic reticulum stressinitiated apoptosis by huperzine A in isoproterenolprovoked myocardial infarction rat model: Role of Nrf2/HO- 1 signaling axis

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    Purpose: To investigate the myocardial protective effect of huperzine A (HPA), a sesquiterpene alkaloid, in a rat model of isoproterenol (ISP)- provoked MI and ER stress.Methods: Three groups of rats were used: control, ISP and ISP+HPA groups. The following indices were assayed using standard protocols: oxidative stress parameters, including NADPH oxidase 4 (NOX4), reactive oxygen species (ROS), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1); indices of calcium homeostasis, namely, sarcoplasmic and endoplasmic reticulum calcium ATPase isoform 2a (SERCA2a); ER stress parameters, viz, protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), glucose-regulated protein 78 (GRP78), and C/EBP homologous protein (CHOP); and indices of apoptosis, i.e., B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax) and caspase-12].Results: Oxidative/ER stress and cardiomyocyte apoptosis were up-modulated (p < 0.05), while SERCA2a, a key calcium handling channel, was downmodulated in the ISP group (p < 0.05). In contrast, HPA treatment ameliorated these ISP-induced myocardial aberrations. (p < 0.05).Conclusion: These results indicate that HPA might be a potential therapeutic candidate for MI and associated cardiac problems. Keywords: Caspase-12, ER stress, Huperzine A, Myocardial infarction, SERCA2

    Large-area, freestanding single-crystal gold of single nanometer thickness

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    Two-dimensional single-crystal metals are highly sought after for next-generation technologies. Here, we report large-area (>10^4 {\mu}m2), single-crystal two-dimensional gold with thicknesses down to a single-nanometer level, employing an atomic-level-precision chemical etching approach. The ultrathin thickness and single-crystal quality endow two-dimensional gold with unique properties including significantly quantum-confinement-augmented optical nonlinearity, low sheet resistance, high transparency and excellent mechanical flexibility. By patterning the two-dimensional gold into nanoribbon arrays, extremely-confined near-infrared plasmonic resonances are further demonstrated with quality factors up to 5. The freestanding nature of two-dimensional gold allows its straightforward manipulation and transfer-printing for integration with other structures. The developed two-dimensional gold provides an emerging platform for fundamental studies in various disciplines and opens up new opportunities for applications in high-performance ultrathin optoelectronic, photonic and quantum devices

    A Virtual Experience System of Bamboo Weaving for Sustainable Research on Intangible Cultural Heritage Based on VR Technology

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    As an important national cultural treasure, intangible cultural heritage (ICH) faces certain problems in inheritance and sustainability. With the development of digital technology, the increasing research and application of virtual reality technology in ICH have been presented. This paper proposes a virtual experience system for Dongyang bamboo weaving, a traditional form of ICH craftsmanship, to display its historical background, cultural connotation, and technical craftsmanship. The learning module of the system is evaluated through the comparative experiments by 8 subjects. From the experimental data, compared with the computer, the average time for subjects to learn bamboo weaving in the system is shorter. The results of the questionnaire indicate that the learning module arouse their interest in bamboo weaving. The result shows the system is able to create an immersive and interactive scene for the users to understand bamboo weaving culture and learn the skills, which may encourage the sustainable development of bamboo weaving culture from the perspective of diffusion and provide research methods for other studies on traditional craftsmanship of ICH

    Dynamic modulation of Ca2+ sparks by mitochondrial oscillations in isolated guinea pig cardiomyocytes under oxidative stress

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    Heavy metal soil pollution from anthropogenic sources such as historical use of fertilizers, poor waste disposal, and spills from industries are a serious environmental problem. This can be especially damaging in developing countries where incentives are limited to remediate these soils, and some of the poorest regions are the most affected. Soil remediation can clean heavy metal polluted soil to a level that is sustainable for the environment and the organisms that inhabit it. Many conventional soil remediation techniques can be very expensive, and resource and energy intensive, making them poor choices for developing countries. However, phytoremediation, an emerging soil remediation technology, is much cheaper and less intensive by using the natural ability of certain plants to clean polluted soils. Although phytoremediation has been considered the best available technology for developing countries with heavy metal polluted soil, it is still being underutilized. In this thesis, through the examination of case studies from the U.S., several barriers are identified that are preventing further implementation of phytoremediation projects in developing countries. These barriers include, the difficulties for developing countries in recognising the scale of heavy metal pollution, a lack of enforcement of environmental legislation and standards, prohibitive costs of projects, problems with the effectiveness of phytoremediation as a soil remediation technology, and a lack of technological knowledge.2018-10-30</p

    A Virtual Experience System of Bamboo Weaving for Sustainable Research on Intangible Cultural Heritage Based on VR Technology

    No full text
    As an important national cultural treasure, intangible cultural heritage (ICH) faces certain problems in inheritance and sustainability. With the development of digital technology, the increasing research and application of virtual reality technology in ICH have been presented. This paper proposes a virtual experience system for Dongyang bamboo weaving, a traditional form of ICH craftsmanship, to display its historical background, cultural connotation, and technical craftsmanship. The learning module of the system is evaluated through the comparative experiments by 8 subjects. From the experimental data, compared with the computer, the average time for subjects to learn bamboo weaving in the system is shorter. The results of the questionnaire indicate that the learning module arouse their interest in bamboo weaving. The result shows the system is able to create an immersive and interactive scene for the users to understand bamboo weaving culture and learn the skills, which may encourage the sustainable development of bamboo weaving culture from the perspective of diffusion and provide research methods for other studies on traditional craftsmanship of ICH

    Electron-Beam Irradiation Induced Regulation of Surface Defects in Lead Halide Perovskite Thin Films

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    Organic-inorganic hybrid perovskites (OIHPs) have been intensively studied due to their fascinating optoelectronic performance. Electron microscopy and related characterization techniques are powerful to figure out their structure-property relationships at the nanoscale. However, electron beam irradiation usually causes damage to these beam-sensitive materials and thus deteriorates the associated devices. Taking a widely used CH3NH3PbI3 film as an example, here, we carry out a comprehensive study on how electron beam irradiation affects its properties. Interestingly, our results reveal that photoluminescence (PL) intensity of the film can be significantly improved along with blue-shift of emission peak at a specific electron beam dose interval. This improvement stems from the reduction of trap density at the CH3NH3PbI3 surface. The knock-on effect helps expose a fresh surface assisted by the surface defect-induced lowering of displacement threshold energy. Meanwhile, the radiolysis process consistently degrades the crystal structure and weaken the PL emission with the increase of electron beam dose. Consequently, the final PL emission comes from a balance between knock-on and radiolysis effects. Taking advantage of the defect regulation, we successfully demonstrate a patterned CH3NH3PbI3 film with controllable PL emission and a photodetector with enhanced photocurrent. This work will trigger the application of electron beam irradiation as a powerful tool for perovskite materials processing in micro-LEDs and other optoelectronic applications
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