1,015 research outputs found

    General displacement arch-cantilever element method for stress analysis of arch dam

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    AbstractBased on the general displacement method and the basic hypothesis of the trial load method, a new advanced trial load method, the general displacement arch-cantilever element method, was proposed to derive the transformation relation of displacements and loads between the surface nodes and middle plane nodes. This method considers the nodes on upstream and downstream surfaces of the arch dam to be exit nodes (master nodes), and the middle plane nodes to be slave nodes. According to the derived displacement and load transformation matrices, the equilibrium equation treating the displacement of middle plane nodes as a basic unknown variable is transformed into one that treats the displacement of upstream and downstream nodes as a basic unknown variable. Because the surface nodes have only three degrees of freedom (DOF), this method can be directly coupled with the finite element method (FEM), which is used for foundation simulation to analyze the stress of the arch dam with consideration of dam-foundation interaction. Moreover, using the FEM, the nodal load of the arch dam can be easily obtained. Case studies of a typical cylindrical arch dam and the Wudongde arch dam demonstrate the robustness and feasibility of the proposed method

    N-Acetyl-N-{2-[(Z)-2-chloro-3,3,3-tri­fluoro­prop-1-en­yl]phen­yl}acetamide

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    The title compound, C13H11ClF3NO2, adopts a Z conformation. Halogen⋯oxygen inter­actions [Cl⋯O = 2.967 (3) Å] in the crystal packing lead to the formation of a dimer joined by two Cl⋯O bonds

    Domain-dependent evolution explains functional homology of protostome and deuterostome complement C3-like proteins

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    Complement proteins emerged early in evolution but outside the vertebrate clade they are poorly characterized. An evolutionary model of C3 family members revealed that in contrast to vertebrates the evolutionary trajectory of C3-like genes in cnidarian, protostomes and invertebrate deuterostomes was highly divergent due to independent lineage and species-specific duplications. The deduced C3-like and vertebrate C3, C4 and C5 proteins had low sequence conservation, but extraordinarily high structural conservation and 2-chain and 3-chain protein isoforms repeatedly emerged. Functional characterization of three C3-like isoforms in a bivalve representative revealed that in common with vertebrates complement proteins they were cleaved into two subunits, b and a, and the latter regulated inflammation-related genes, chemotaxis and phagocytosis. Changes within the thioester bond cleavage sites and the a-subunit protein (ANATO domain) explained the functional differentiation of bivalve C3-like. The emergence of domain-related functions early during evolution explains the overlapping functions of bivalve C3-like and vertebrate C3, C4 and C5, despite low sequence conservation and indicates that evolutionary pressure acted to conserve protein domain organization rather than the primary sequence.info:eu-repo/semantics/publishedVersio

    Evaluation of parameters affecting Agrobacterium-mediated transient expression in citrus

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    Abstract Agrobacterium-mediated transient expression assays are a convenient alternative to stable expression because they are simple, easy to perform, and achieve gene expression rapidly. This study investigated the factors affecting transient gene expression efficiency in citrus by observing the cryo-sectioning of leaf samples under a laser confocal microscope. These factors included the composition of the infiltration buffer, the Agrobacterium cell density, the leaf development stage, the incubation temperature, and plant genotype. The highest transient expression level of yellow fluorescent protein (YFP) was detected in Mexican lime (Citrus aurantifolia) on the third day after the intermediate-aged leaves were infiltrated with the improved infiltration buffer 1 (15 mmol L−1 2-(N-morpholino) ethanesulfonic acid, 10 mmol L−1 MgCI2, and 200 pmol L−1 acetosyringone), which had an optical density of 0.8 and was incubated at 22°C. Additionally, this transient expression assay was applied to other citrus genotypes. Of note, trifoliate orange (Poncirus trifoliata) and kumquat (Fortunella obovate) had higher expression efficiency than other six genotypes of the Citrus genus. Our study provides research basis for the selection of optimization strategies in transient gene expression and improves the method for available genome investigation in citrus

    Changes of Nuclear Matrix Proteins Following the Differentiation of Human Osteosarcoma MG-63 Cells

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    Human osteosarcoma MG-63 cells were induced into differentiation by 5mmol/L hexamethylene bisacetamide (HMBA). Their nuclear matrix proteins (NMPs) were selectively extracted and subjected to two-dimensional gel electrophoresis analysis. The results of protein patterns were analyzed by Melanie software. The spots of differentially expressed NMPs were excised and subjected to in situ digestion with trypsin. The maps of peptide mass fingerprinting were obtained by MALDI-TOF-MS analysis, and were submitted for NCBI database searches by Mascot tool. There were twelve spots changed remarkably during the differentiation induced by HMBA, nine of which were identified. The roles of the regulated proteins during the MG-63 differentiation were analyzed. This study suggests that the induced differentiation of cancer cells is accompanied by the changes of NMPs, and confirms the presence of some specific NMPs related to the cancer cell proliferation and differentiation. The changed NMPs are potential markers for cancer diagnosis or targets for cancer therapy

    More on volume dependence of spectral weight function

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    Spectral weight functions are easily obtained from two-point correlation functions and they might be used to distinguish single-particle from multi-particle states in a finite-volume lattice calculation, a problem crucial for many lattice QCD simulations. In previous studies, it is shown that the spectral weight function for a broad resonance shares the typical volume dependence of a two-particle scattering state i.e. proportional to 1/L31/L^3 in a large cubic box of size LL while the narrow resonance case requires further investigation. In this paper, a generalized formula is found for the spectral weight function which incorporates both narrow and broad resonance cases. Within L\"uscher's formalism, it is shown that the volume dependence of the spectral weight function exhibits a single-particle behavior for a extremely narrow resonance and a two-particle behavior for a broad resonance. The corresponding formulas for both A1+A^+_1 and T1T^-_1 channels are derived. The potential application of these formulas in the extraction of resonance parameters are also discussed

    6-Hy­droxy-4-(pyridin-3-yl)-5-(2-thienyl­carbon­yl)-6-trifluoro­meth­yl-3,4,5,6-tetra­hydro­pyrimidin-2(1H)-one

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    In the title compound, C15H12F3N3O3S, the pyrimidine ring adopts a half-chair conformation with the mean plane formed by the ring atoms excluding the C atom bonded to thio­phene-2-carbonyl group lying nearly perpendicular to the pyridine and thio­phene rings, making dihedral angles of 84.91 (4) and 87.40 (5)°, respectively. The dihedral angle between the pyridine and thio­phene rings is 54.44 (5)°. The crystal structure is stabilized by inter­molecular O—H⋯O and N—H⋯N hydrogen bonds and weak C—H⋯O inter­actions further consolidate the structure
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