Publications by authors named "Yongyi Hu"

Background & Aims: Previous observational studies have yielded inconsistent findings regarding associations between red/processed meat intake and the risk of cardiovascular disease (CVD). Some studies have suggested positive relationships, while others have demonstrated no significant associations. However, causal effects remain uncertain.

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A novel α,β-regioselective [3+2] cycloaddition reaction of arylallene with C,N-cyclic azomethine imine is reported. The axial-to-central chirality transfer phenomenon has been disclosed with chiral allenes in the reaction. The wide substrate scope, including different functional groups and natural products, reveals the generality of the methodology.

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A highly efficient and environmentally-friendly base-mediated transition metal-free direct thiophilic catalytic approach is reported for the synthesis of -benzhydryl-phosphorothioates by reacting phosphite nucleophiles with diarylmethanethione. A wide variety of thioketones were coupled with different phosphite derivatives to provide the corresponding phosphorothioates in good to excellent yields. The control experiments and density functional theory (DFT) calculations rely on the regio-selective thiophilic addition of a phosphite nucleophile umpolung protocols.

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A multishell mold structure and water-immersion cooling method (MSMWI) is proposed for the directional solidification of castings. A four-layer-shell sand mold was designed for a bar with diameter of 40 mm. As the aluminum melt was poured, the multishell mold was gradually immersed in water, and the water level drove the advancement of the solidification front from bottom to top.

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The author-proposed skeletal sand mold, which mainly includes a shell, air cavities and a truss support structure, has been experimentally proven to be very useful in controlling the cooling of casting at local areas and at different periods of the casting process. The modeling and simulation of the casting process using a skeletal sand mold were systemically analyzed. Complicated casting/mold and mold/air boundaries, and the thermal and mechanical behavior of the skeletal sand mold during the casting process were highlighted.

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A regio- and stereoselective hydrosilylation of 1,3-diynes has been developed relying on catalysts generated from bench-stable Co(acac) and dppp ligand. A variety of symmetrical and unsymmetrical 1,3-diynes undergo this transformation, yielding the corresponding silyl-functionalized 1,3-enynes in high yields with excellent regioselectivity. Gram-scale reactions and further transformations of the silyl-containing 1,3-enyne products highlight the synthetic utilities of this Co-catalyzed hydrosilylation of 1,3-diynes.

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Hydrophobic segments and amino moieties in polymeric nonviral gene vectors play important roles in overcoming a cascade of barriers for efficient gene delivery. However, it remains a great challenge to facilely construct well-defined multifunctional polymers through optimization of the amino and hydrophobic groups. Herein, we choose thiolactone chemistry to perform the ring opening reaction of varying hydrophobic groups-modified thiolactones by various amines to generate mercapto groups for further Michael addition reaction with poly[2-(acryloyloxy)ethyl methacrylate] (PAOEMA).

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