604 research outputs found

    Epimedium brevicornu Maxim extract shows protective activity against Alzheimer's disease in mice

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    Purpose: To investigate the protective effect of Epimedium brevicornu Maxim extract (EBME) against Alzheimer's disease in 3xTg-AD mice. Methods: The cognitive function of 3xTg-AD mice was assessed using Morris water maze test. The levels of amyloid beta deposits and NeuN in the mouse hippocampus were evaluated by immunohistochemistry. Brain neurotrophic-derived factor (BDNF) and tyrosine kinase B (TrkB) expressions were examined by western blot analysis. Results: EBME treatment significantly ameliorated learning and memory deficits in AD mice, as shown by the increased time spent in the target zone during probe tests. Compared with the 3xTg-AD mice (8.4 ± 1.1 s), the escape latency in animals treated with 600 mg/kg EBME (21.5 ± 1.1 s) was significantly increased (p < 0.01). In addition, EBME significantly decreased Aβ deposits, increased NeuN-positive cells, and upregulated the expressions of BDNF (1.5 ± 0.2, p < 0.05) and TrkB (1.6 ± 0.2, p < 0.05) in the 3xTg AD mice. Conclusion: EBME treatment may be a useful therapeutic strategy for managing memory impairment

    Floquet Weyl semimetal phases in light-irradiated higher-order topological Dirac semimetals

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    Floquet engineering, the concept of tailoring a system by a periodic drive, is increasingly exploited to design and manipulate topological phases of matter. In this work, we study periodically driven higher-order topological Dirac semimetals associated with a kk-dependent quantized quadrupole moment by applying circularly polarized light. The undriven Dirac semimetals feature gapless higher-order hinge Fermi arc states which are the consequence of the higher-order topology of the Dirac nodes. Floquet Weyl semimetal phases with hybrid-order topology, characterized by both a kk-dependent quantized quadrupole moment and a kk-dependent Chern number, emerge when illumining circularly polarized light. Such Floquet Weyl semimetals support both hinge Fermi arc states and topological surface Fermi arc states. In addition, Floquet Weyl semimetals with tilted Weyl cones in higher-order topological Dirac semimetals are also discussed. Considering numerous higher-order topological Dirac semimetal materials were recently proposed, our findings can be testable soon.Comment: Accepted for publication as a Letter in Phys. Rev.

    Poly[(acetato-κ2 O,O′)aqua­(μ4-1H-benzimidazole-5,6-dicarboxyl­ato-κ5 N 3:O 5,O 5′:O 5,O 6:O 6′)praseodymium(III)]

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    In the title complex, [Pr(C9H4N2O4)(C2H3O2)(H2O)]n, the PrIII ion is coordinated by five O atoms and one N atom from four benzimidazole-5,6-dicarboxyl­ate ligands, two O atoms from an acetate ligand and one water mol­ecule, giving a tricapped trigonal-prismatic geometry. The benzimidazole-5,6-dicarboxyl­ate and acetate ligands connect the PrIII ions, forming a layer in the ac plane; the layers are further linked by N—H⋯O and O—H⋯O hydrogen bonding and π–π stacking inter­actions between neighboring pyridine rings [the centroid–centroid distance is 3.467 (1) Å], assembling a three-dimensional supra­molecular network. The acetate methyl group is disordered over two positions with site-occupancy factors of 0.75 and 0.25

    AT2022cmc: a Tidal Disruption Event with Two-component Jet in a Bondi-profile Circumnuclear Medium

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    A supermassive black hole can launch a relativistic jet when it violently disrupts a star that passes too close. Such jetted tidal disruption events (TDEs) are rare and unique tools to investigate quiescent supermassive black holes, jet physics, and circumnuclear environment at high redshift. The newly discovered TDE AT2022cmc (z1.193z\sim 1.193) providing rich multi-band (X-ray, UV, optical, sub-millimeter, and radio) data, has been interpreted as the fourth on-axis jetted TDE. In this work, we constrain the circumnuclear medium (CNM) density profile with both closure relation (CR) test and detailed forward shock model fit with Markov chain Monte Carlo (MCMC) approach to the multi-band (optical, sub-millimeter, and radio) data of AT2022cmc.We find that the CNM density profile of AT2022cmc is nRkn\propto R^{-k} with k1.68k \sim 1.68, implying a Bondi accretion in history. Furthermore, our model fit result suggests a two-component jet in AT2022cmc, indicating a similar jet physics to well-studied jetted TDE Sw J1644+57.Comment: accepted in Ap

    Transplantation of a Peripheral Nerve with Neural Stem Cells Plus Lithium Chloride Injection Promote the Recovery of Rat Spinal Cord Injury

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    Transplantation of neural stem cells (NSCs) holds great potential for the treatment of spinal cord injury (SCI). However, transplanted NSCs poorly survive in the SCI environment. We injected NSCs into tibial nerve and transplanted tibial nerve into a hemisected spinal cord and investigated the effects of lithium chloride (LiCl) on the survival of spinal neurons, axonal regeneration, and functional recovery. Our results show that most of the transplanted NSCs expressed glial fibrillary acidic protein, while there was no obvious expression of nestin, neuronal nuclei, or acetyltransferase found in NSCs. LiCl treatment produced less macrosialin (ED1) expression and axonal degeneration in tibial nerve after NSC injection. Our results also show that a regimen of LiCl treatment promoted NSC differentiation into NF200-positive neurons with neurite extension into the host spinal cord. The combination of tibial nerve transplantation with NSCs and LiCl injection resulted in more host motoneurons surviving in the spinal cord, more regenerated axons in tibial nerve, less glial scar area, and decreased ED1 expression. We conclude that lithium may have therapeutic potential in cell replacement strategies for central nervous system injury due to its ability to promote survival and neuronal generation of grafted NSCs and reduced host immune reaction

    6-Methyl-2-p-tolyl-4-[3-(trifluoro­meth­yl)phen­yl]pyridazin-3(2H)-one

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    In the title mol­ecule, C19H15F3N2O, the benzene rings of the tolyl and trifluoro­methyl­phenyl groups form dihedral angles of 64.1 (2) and 38.5 (2)°, respectively, with the pyridazine ring. The CF3 group is disordered over two orientations, with site-occupancy factors of ca 0.56 and 0.44

    Two-scale topology of optimization of functionally graded lattice structures with varying volume fraction - 变体分比功能梯度点阵结构两尺度拓扑优化设计

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    Functionally graded lattice structures enjoy widespread attention due to their lightweight, high specific stiffness/strength, high fracture resistance and other good performances, yet design optimization of these structures is still a challenging task due its cross-scale and spatially graded geometrical characteristics. In this work, a two-step optimization strategy is proposed to design functionally graded lattice structures. In the first step, the Discrete Material Optimization (DMO) is conducted to obtain optimal macro structural configuration and micro structural distribution. In the second step, parametric optimization is conducted to obtain graded lattice structures with varying volume fraction. The advantage of this work includes the adoption of the varying volume fraction operation, which enables the management of complex microstructures, and the pattern of spatially graded microstructure, which further broadens design space and improves structural stiffness, facilitating efficient use of materials. Finally, several numerical examples are presented to verify the effectiveness of the proposed method which significantly expands design space and effectively improve the structural stiffness

    Visualizing the elongated vortices in γ\gamma-Ga nanostrips

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    We study the magnetic response of superconducting γ\gamma-Ga via low temperature scanning tunneling microscopy and spectroscopy. The magnetic vortex cores rely substantially on the Ga geometry, and exhibit an unexpectedly-large axial elongation with aspect ratio up to 40 in rectangular Ga nano-strips (width ll << 100 nm). This is in stark contrast with the isotropic circular vortex core in a larger round-shaped Ga island. We suggest that the unusual elongated vortices in Ga nanostrips originate from geometric confinement effect probably via the strong repulsive interaction between the vortices and Meissner screening currents at the sample edge. Our finding provides novel conceptual insights into the geometrical confinement effect on magnetic vortices and forms the basis for the technological applications of superconductors.Comment: published in Phys. Rev. B as a Rapid Communicatio

    Evaluation of three high abundance protein depletion kits for umbilical cord serum proteomics

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    <p>Abstract</p> <p>Background</p> <p>High abundance protein depletion is a major challenge in the study of serum/plasma proteomics. Prior to this study, most commercially available kits for depletion of highly abundant proteins had only been tested and evaluated in adult serum/plasma, while the depletion efficiency on umbilical cord serum/plasma had not been clarified. Structural differences between some adult and fetal proteins (such as albumin) make it likely that depletion approaches for adult and umbilical cord serum/plasma will be variable. Therefore, the primary purposes of the present study are to investigate the efficiencies of several commonly-used commercial kits during high abundance protein depletion from umbilical cord serum and to determine which kit yields the most effective and reproducible results for further proteomics research on umbilical cord serum.</p> <p>Results</p> <p>The immunoaffinity based kits (PROTIA-Sigma and 5185-Agilent) displayed higher depletion efficiency than the immobilized dye based kit (PROTBA-Sigma) in umbilical cord serum samples. Both the PROTIA-Sigma and 5185-Agilent kit maintained high depletion efficiency when used three consecutive times. Depletion by the PROTIA-Sigma Kit improved 2DE gel quality by reducing smeared bands produced by the presence of high abundance proteins and increasing the intensity of other protein spots. During image analysis using the identical detection parameters, 411 ± 18 spots were detected in crude serum gels, while 757 ± 43 spots were detected in depleted serum gels. Eight spots unique to depleted serum gels were identified by MALDI- TOF/TOF MS, seven of which were low abundance proteins.</p> <p>Conclusions</p> <p>The immunoaffinity based kits exceeded the immobilized dye based kit in high abundance protein depletion of umbilical cord serum samples and dramatically improved 2DE gel quality for detection of trace biomarkers.</p
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