510 research outputs found

    Hygienic Property and Water Resistance of Waterborne Polyacrylate/Flower-like ZnO Composite Coatings

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    Content: Polyacrylate as film-forming materials has been widely used in leather finishing, but its compactness significantly obstructs the hygienic property of upper leather. Therefore, considerable efforts have been made to endow polyacrylate with required properties. In this study, we demonstrated a facile and rapid sonochemical process to synthesis the flower-like ZnO nanostructures. The related morphology and structure of product were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Meanwhile, flower-like ZnO were introduced into the polyacrylate matrix by physical blending method, whose morphology, latex stability, water vapor permeability and water resistance were measured. The results showed that flower-like ZnO assembled by ellipsoid-like nanorods with the length of about 600 nm was successfully fabricated. The sizes of flower-like ZnO were 1.2 μm. According to SEM images, flower-like ZnO evenly dispersed were observed in composite matrix. Compared with pure polyacrylate, polyacrylate/flower-like ZnO composites exhibited the superior stability. Meanwhile, its water vapor permeability and water resistancewere increased by 52.91% and 53.13%, severally. The reason for this is that ZnO with rough structure can increase voids in polyacrylate film and thus improving hygienic property of polyacrylate film. Additionally, the hydrophilic groups on surface of ZnO can product the crosslinking with polyacrylate chains, which contributed to the enhancement of water resistance. Thus, a promising coating with hygienic property and water resistance for leather finishing agent was approved. Take-Away: 1. Polyacrylate/flower-like ZnO composites exhibited excellent hygienic property. 2. This composite coating achieves simultaneous enhancement in water vapor permeability and water resistance. 3. The morphology of ZnO can effect the properties of polyacrylate

    Multi-objective optimization of electrical distribution network operation considering reconfiguration and soft open points

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    High penetration levels of Distributed Generations (DG) significantly affect the operations of electrical distribution networks. In this paper, Distribution Network Reconfiguration (DNR), and the implementation of Soft Open Point (SOP) – a distribution-level power electronic device are investigated as effective solutions to facilitate large DG penetrations while meeting network operational constraints. DNR is developed based on the ant colony optimization, and the optimal SOP outputs are determined using the Taxi-cab algorithm after determining the network configuration. Both optimization problems are formulated within a multi-objective framework using the Pareto optimality. The performances of DNR and SOP to improve network operations are demonstrated on a modified 33-bus distribution system with various DG penetrations

    miR-126 promotes angiogenesis and attenuates inflammation after contusion spinal cord injury in rats

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    AbstractMicroRNAs are a class of small RNAs that regulate the expression of target mRNAs by inhibiting translation or destabilizing target mRNAs. miR-126 is a microRNA that is highly enriched in endothelial cells. miR-126 has been found to promote angiogenesis and inhibit vascular inflammation in endothelial cells by repressing three target genes Sprouty-related EVH1 domain-containing protein 1 (SPRED1), phosphoinositol-3 kinase regulatory subunit 2 (PIK3R2), and vascular cell adhesion molecule 1 (VCAM1). Our previous study showed that the expression of miR-126 was downregulated after spinal cord injury (SCI). Therefore, we wanted to examine whether upregulation of miR-126 could promote angiogenesis, inhibit inflammation, and exert a positive effect on recovery after contusion SCI. In this study, we found that increased levels of miR-126 promoted angiogenesis, and inhibited leukocyte extravasation into the injured spinal cord, which was concurrent with downregulation of mRNA and protein expression of three validated miR-126 target genes, SPRED1, PIK3R2, and VCAM1. Moreover, a dose-dependent effect of miR-126 was observed in rescuing tissue damage and improving the functional deficit after SCI. Thus, the present study indicated that miR-126 played an important role in angiogenesis and inflammation after SCI

    Multiple Unpinned Dirac Points in Group-Va Single-layers with Phosphorene Structure

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    Emergent Dirac fermion states underlie many intriguing properties of graphene, and the search for them constitute one strong motivation to explore two-dimensional (2D) allotropes of other elements. Phosphorene, the ultrathin layers of black phosphorous, has been a subject of intense investigations recently, and it was found that other group-Va elements could also form 2D layers with similar puckered lattice structure. Here, by a close examination of their electronic band structure evolution, we discover two types of Dirac fermion states emerging in the low-energy spectrum. One pair of (type-I) Dirac points is sitting on high-symmetry lines, while two pairs of (type-II) Dirac points are located at generic kk-points, with different anisotropic dispersions determined by the reduced symmetries at their locations. Such fully-unpinned (type-II) 2D Dirac points are discovered for the first time. In the absence of spin-orbit coupling, we find that each Dirac node is protected by the sublattice symmetry from gap opening, which is in turn ensured by any one of three point group symmetries. The spin-orbit coupling generally gaps the Dirac nodes, and for the type-I case, this drives the system into a quantum spin Hall insulator phase. We suggest possible ways to realize the unpinned Dirac points in strained phosphorene.Comment: 30 pages, 6 figure

    R-spondin1 synergizes with Wnt3A in inducing osteoblast differentiation and osteoprotegerin expression

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    AbstractR-spondins are a new group of Wnt/β-catenin signaling agonists, however, the role of these proteins in bone remains unclear. We reported herein that R-sponin1 (Rspo1) acted synergistically with Wnt3A to activate Wnt/β-catenin signaling in the uncommitted mesenchymal C2C12 cells. Furthermore, we found that Rspo1 at concentrations as low as 10ng/ml synergized strongly with Wnt3A to induce C2C12 osteoblastic differentiation and osteoprotegerin expression. These events were blocked by Wnt/β-catenin signaling antagonist Dickkopf-1. Finally, we demonstrated that Rspo1 synergized with Wnt3A to induce primary mouse osteoblast differentiation. Together, these findings suggest that Rpos1 may play an important role in bone remodeling

    Calcium Oxalate Induces Renal Injury through Calcium-Sensing Receptor

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    Objective. To investigate whether calcium-sensing receptor (CaSR) plays a role in calcium-oxalate-induced renal injury. Materials and Methods. HK-2 cells and rats were treated with calcium oxalate (CaOx) crystals with or without pretreatment with the CaSR-specific agonist gadolinium chloride (GdCl3) or the CaSR-specific antagonist NPS2390. Changes in oxidative stress (OS) in HK-2 cells and rat kidneys were assessed. In addition, CaSR, extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal protein kinase (JNK), and p38 expression was determined. Further, crystal adhesion assay was performed in vitro, and the serum urea and creatinine levels and crystal deposition in the kidneys were also examined. Results. CaOx increased CaSR, ERK, JNK, and p38 protein expression and OS in vitro and in vivo. These deleterious changes were further enhanced upon pretreatment with the CaSR agonist GdCl3 but were attenuated by the specific CaSR inhibitor NPS2390 compared with CaOx treatment alone. Pretreatment with GdCl3 further increased in vitro and in vivo crystal adhesion and renal hypofunction. In contrast, pretreatment with NPS2390 decreased in vitro and in vivo crystal adhesion and renal hypofunction. Conclusions. CaOx-induced renal injury is related to CaSR-mediated OS and increased mitogen-activated protein kinase (MAPK) signaling, which subsequently leads to CaOx crystal adhesion
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