2,643 research outputs found

    Construction of spirocarbocycles via gold-catalyzed intramolecular dearomatization of naphthols.

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    A highly efficient, gold-catalyzed intramolecular dearomatization reaction of naphthols via 5-endo-dig cyclization is described. This facile and direct approach furnishes spirocarbocycles in excellent yields under mild conditions

    Development of a BIM and Barcode based Material Management System for Curtain Wall Industry

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    The construction industry is slower to adopt new technologies than other industries. Traditional construction industry material management system involves tedious paperwork, frequent phone calls and challenging coordination, posing many difficulties for the project management. Recent development in the use of information and communication technologies in the Architecture, Engineering and Construction (AEC), namely the building information modeling (BIM), promises to introduce major changes in visualization, coordination and planning processes of the engineering projects. The impact of the building’s curtain wall has become increasingly more important when determining the operational and economic performance of construction projects. And as a recognized discipline of the construction industry, curtain wall design, and fabrication and installation process involves numerous stakeholders including designers, contractors, purchasing staff, suppliers, distributors, and on-site installers. It is believed that the material tracking system, when integrated with BIM, can successfully address the major problems of the curtain wall industry. In this paper, the authors analyzed the current practice of material management in the curtain wall industry and proposed a BIM and barcode integrated material management system, which aims to provide a BIM based material management framework from the design phase to the construction phase, streamlining material management process and promoting collaborative working processes in the curtain wall industry

    Smoothing noisy spectroscopic data with many-knot spline method

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    In this paper, we present the development of a many-knot spline method derived to remove the statistical noise in the spectroscopic data. This method is an expansion of the B-spline method. Compared to the B-spline method, the many-knot spline method is significantly faster.Comment: 3pages, 2 figure

    1,4-Bis{3-[4-(dimethyl­amino)benzyl­ideneamino]prop­yl}piperazine

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    The mol­ecule of the title compound, C28H42N6, has site symmetry with the centroid of the piperazine ring located on an inversion center. The piperazine ring adopts a chair conformation. The benzene ring and propyl­piperazine are on opposite sides of the C=N bond, showing an E configuration

    High-efficiency robust perovskite solar cells on ultrathin flexible substrates.

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    Wide applications of personal consumer electronics have triggered tremendous need for portable power sources featuring light-weight and mechanical flexibility. Perovskite solar cells offer a compelling combination of low-cost and high device performance. Here we demonstrate high-performance planar heterojunction perovskite solar cells constructed on highly flexible and ultrathin silver-mesh/conducting polymer substrates. The device performance is comparable to that of their counterparts on rigid glass/indium tin oxide substrates, reaching a power conversion efficiency of 14.0%, while the specific power (the ratio of power to device weight) reaches 1.96 kW kg(-1), given the fact that the device is constructed on a 57-μm-thick polyethylene terephthalate based substrate. The flexible device also demonstrates excellent robustness against mechanical deformation, retaining >95% of its original efficiency after 5,000 times fully bending. Our results confirmed that perovskite thin films are fully compatible with our flexible substrates, and are thus promising for future applications in flexible and bendable solar cells

    Duality between the deconfined quantum-critical point and the bosonic topological transition

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    Recently significant progress has been made in (2+1)(2+1)-dimensional conformal field theories without supersymmetry. In particular, it was realized that different Lagrangians may be related by hidden dualities, i.e., seemingly different field theories may actually be identical in the infrared limit. Among all the proposed dualities, one has attracted particular interest in the field of strongly-correlated quantum-matter systems: the one relating the easy-plane noncompact CP1^1 model (NCCP1^1) and noncompact quantum electrodynamics (QED) with two flavors (N=2N = 2) of massless two-component Dirac fermions. The easy-plane NCCP1^1 model is the field theory of the putative deconfined quantum-critical point separating a planar (XY) antiferromagnet and a dimerized (valence-bond solid) ground state, while N=2N=2 noncompact QED is the theory for the transition between a bosonic symmetry-protected topological phase and a trivial Mott insulator. In this work we present strong numerical support for the proposed duality. We realize the N=2N=2 noncompact QED at a critical point of an interacting fermion model on the bilayer honeycomb lattice and study it using determinant quantum Monte Carlo (QMC) simulations. Using stochastic series expansion QMC, we study a planar version of the S=1/2S=1/2 JJ-QQ spin Hamiltonian (a quantum XY-model with additional multi-spin couplings) and show that it hosts a continuous transition between the XY magnet and the valence-bond solid. The duality between the two systems, following from a mapping of their phase diagrams extending from their respective critical points, is supported by the good agreement between the critical exponents according to the proposed duality relationships.Comment: 14 pages, 9 figure

    MARCH9 Suppresses Lung Adenocarcinoma Progression by Downregulating ICAM-1

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    Background/Aims: To investigate the clinical significance and functional mechanisms of membrane-associated RING-CH protein 9 (MARCH9) in lung adenocarcinoma (LAC). Methods: Immunohistochemistry staining was performed to explore the expression of MARCH9 in LAC tissues and adjacent normal lung tissues. Patients’ prognosis was evaluated using overall survival. The prognostic role of MARCH9 was tested with univariate and multivariate analyses. To confirm the effect of MARCH9 in cell proliferation and invasion, overexpression of MARCH9 was induced in two LAC cell lines. Cell cycle, apoptosis, migration, invasion, and immunoprecipitation experiments were performed to further explore the signaling pathways involved. Results: Analysis of a series of 143 clinical samples revealed that MARCH9 was down-regulated in tumor tissues compared with normal lung tissues, and this was closely associated with lymph node metastasis (P = 0.004). Univariate and multivariate analyses indicated that MARCH9 was an independent prognostic biomarker for LAC; low MARCH9 expression indicated poor overall survival. Cellular studies with A549 and H1299 cells demonstrated that MARCH9 can attenuate tumor migration and invasion but had little effect on cell cycle or apoptosis. Moreover, an interaction between MARCH9 and ICAM-1 protein was identified, and overexpression of MARCH9 was found to attenuate the oncogenic effect of ICAM-1, suggesting that MARCH9 may inhibit tumor progression by downregulating ICAM-1 signaling. Conclusion: MARCH9 downregulation in LAC tissues correlated with poor clinical outcomes. MARCH9 may serve as a novel biomarker and potential therapeutic target for LAC
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