48 research outputs found

    Electroacupuncture Suppresses Discrete Cue-Evoked Heroin-Seeking and Fos Protein Expression in the Nucleus Accumbens Core in Rats

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    Relapse to drug seeking was studied using a rodent model of reinstatement induced by exposure to drug-related cues. Here, we used intravenous drug self-administration procedures in rats to further investigate the beneficial effects of electroacupuncture (EA) on heroin-seeking behavior in a reinstatement model of relapse. We trained Sprague-Dawley rats to nose-poke for i.v. heroin either daily for 4 h or 25 infusions for 14 consecutive days. Then the rats were abstinent from heroin for two weeks. 2 Hz EA stimulation was conducted once daily for 14 days during heroin abstinence. We tested these animals for contextual and discrete cue-induced reinstatement of active responses. We also applied immunohistochemistry to detect Fos-positive nuclei in the nucleus accumbens (NACc) core and shell after reinstatement test. We found that active responses elicited by both contextual cues and discrete cues were high in the rats trained with heroin than in saline controls. EA treatment significantly reduced active responses elicited by discrete cues. EA stimulation attenuated Fos expression in the core but not the shell of the NACc. Altogether, these results highlight the therapeutic benefit of EA in preventing relapse to drug addiction

    Sam50 Regulates PINK1-Parkin-Mediated Mitophagy by Controlling PINK1 Stability and Mitochondrial Morphology

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    PINK1 and Parkin mediate mitophagy, the cellular process that clears dysfunctional mitochondria. Mitophagy is regulated by mitochondrial dynamics, but the molecules linking these two processes remain poorly understood. Here, we show that Sam50, the core component of the sorting and assembly machinery (SAM), is a critical regulator of mitochondrial dynamics and PINK1-Parkin-mediated mitophagy. In response to Sam50 depletion, normal tubular mitochondria are first fragmented and subsequently merged into large spheres. Sam50 interacts with PINK1 to facilitate its processing and degradation. Depletion of Sam50 results in PINK1 accumulation, Parkin recruitment, and mitophagy. Interestingly, Sam50 deficiency induces a piecemeal mode of mitophagy that eliminates mitochondria “bit by bit” but spares mtDNA. In C. elegans, the Sam50 homolog gop-3 is required for the maintenance of mitochondrial morphology and mass. Our findings reveal that Sam50 directly links mitochondrial dynamics and mitophagy and that Sam50 depletion induces elimination of mitochondria without affecting mtDNA content

    Boosting Oxygen and Peroxide Reduction Reactions on PdCu Intermetallic Cubes

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    Palladium‐based nanocatalysts have the potential to replace platinum‐based catalysts for fuel‐cell reactions in alkaline electrolytes, especially PdCu intermetallic nanoparticles with high electrochemical activity and stability. However, unlike the synthetic methods for obtaining the nanoparticles, the effect of PdCu shape on the performance is relatively less well studied. Here, we demonstrate the facet dependence of PdCu intermetallics on the oxygen reduction reaction (ORR) and peroxide reduction, and reveal that the {100} dominant PdCu cubes have a much higher ORR mass activity and specific activity than spheres at 0.9 V vs. RHE, which is four and five times that of commercial Pd/C and Pt/C catalysts, respectively, and show only a 31.7 % decay after 30 000 cycles in the stability test. Moreover, cubic PdCu nanoparticles show higher peroxide electroreduction activity than Pd cubes and PdCu spheres. Density functional theory (DFT) calculation reveals that the huge difference originates from the reduction in oxygen adsorption energy and energy barrier of peroxide decomposition on the ordered {100} PdCu surface. Given the relationship between the shape and electrochemical performance, this study will contribute to further research on electrocatalytic improvements of catalysts in alkaline environments.Shape the future: PdCu intermetallic cubes and spheres are synthesized to investigate the facet dependence on the oxygen reduction reaction and peroxide reduction. The cubes show large improvements in mass activity towards both reactions, compared with the spheres. DFT calculation uncovers that the dominant {100} faces of the cubes offer more appropriate oxygen adsorption and are thermodynamically favorable for peroxide reduction compared to the surface of spheres.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155903/1/celc202000381.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155903/2/celc202000381_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155903/3/celc202000381-sup-0001-misc_information.pd

    A Non‐Pt Electronically Coupled Semiconductor Heterojunction for Enhanced Oxygen Reduction Electrocatalytic Property

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    Hybrid faceted‐Ag3PO4/cube‐Cu2O composite materials have been fabricated and employed as oxygen reduction electrocatalysts for proton exchange membrane fuel cells (PEMFCs). The charge separation effect via the formation of PN junction has been demonstrated to boost the electrocatalysis toward oxygen reduction reaction. The as‐prepared rhombic dodecahedron‐Ag3PO4/cube‐Cu2O/C hybrid catalyst shows a mass‐specific activity of 109.80 mA/mgAg, which is about 6.4 times that of pure rhombic dodecahedron‐Ag3PO4/C catalyst (17.20 mA/mgAg). The density functional theory (DFT) calculation based on the density of states (DOS) further proved the optimal tunable effect, which is in pace with demonstration of electron transfer direction revealed by X‐ray photoelectron spectroscopy (XPS) analysis. Our work establishes a theoretical and practical basis for the rational design of newly non‐Pt hybrid catalysts, moreover, advances the future efficient application of PEMFCs.A cost effective electronically coupled semiconductor heterojunction between facet‐Ag3PO4 and Cu2O cube is reported. Its high electrocatalytic activity towards oxygen reduction reaction (ORR) indicates that electron distribution can be controlled through the interfacial engineering between Ag3PO4 and Cu2O. This paves way to rationally design new non‐Pt hybrid catalysts, and moreover advances the future efficient applications of proton exchange membrane fuel cells (PEMFCs).Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149290/1/slct201900615.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149290/2/slct201900615-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149290/3/slct201900615_am.pd

    Marine Organism Detection and Classification from Underwater Vision Based on the Deep CNN Method

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    Seabed fishing depends on humans in common, for instance, the sea cucumber, sea urchin, and scallop fishing, which is always a very dangerous task. Considering the underwater complex environment conditions such as low temperature, dim vision, and high pressure, collecting the marine products using underwater robots is commonly regarded as a feasible solution. The key technique of the underwater robot development is to detect and locate the main target from underwater vision. This research is based on the deep convolutional neural network (CNN) to realize the target recognition from underwater vision. The RPN (Region Proposal Network) is used to optimize the feature extraction capability. Deep learning dataset is prepared using an underwater video obtained from a sea cucumber fishing ROV (Remote Operated Vehicle). The inspiration of the network structure and the improvements come from the Faster RCNN and Hypernet method, and for the underwater dataset, the method proposed in this paper shows a good performance of recall and object detection accuracy. The detection runs with a speed of 17 fps on a GPU, which is applicable to be used for real-time processing

    Bow Flare Water Entry Impact Prediction and Simulation Based on Moving Particle Semi-Implicit Turbulence Method

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    Prandtl’s mixing length method and the k-epsilon method are introduced into the Moving Particle Semi-Implicit (MPS) method for the purpose of modeling turbulence effects associated with water entries of two-dimensional (2D) bow flare section. The presented numerical method is validated by comparing its numerical prediction with experimental data and other numerical results obtained from the Boundary Element Method (BEM). The time histories of the pressure and the vertical slamming force acting on the dropping ship section subjected to various conditions with different dropping velocity and inclined angles are analyzed. The results show that both the pressure and the vertical slamming force are in good agreement with the experimental data
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