Catalytic asymmetric hydrogenation of enamido phosphorus derivatives is one of the most efficient methods for the construction of chiral amino phosphorus products, among which the congested tetra-substituted substrates remains an unaddressed challenge. In this study, we utilize a commercially available Rh-Josiphos system for the efficient and stereoselective hydrogenation of a wide set of tetra-substituted cyclic β-enamido phosphonates/phosphine oxides, thus enabling access to chiral β-amino phosphorus compounds featuring two vicinal stereocenters. This protocol was broadly applicable to different ring systems possessing various phosphonate/phosphine oxide groups and further applied in the preparation of amino-phosphine ligands. DFT mechanistic explorations indicate that the C=C migratory insertion into Rh III À H bond could be the rateand stereo-determining step. The origins of stereoselectivity are revealed through distortion/interaction analysis, which is primarily regulated by distinguished dispersion interactions and steric repulsions.
The fast development of solid-liquid phase change materials calls for nanomaterials with large specific surface area for rapid heat transfer and encapsulation of phase change materials to prevent potential leakage. Here we report a combined miniemulsion/emulsion polymerization method to prepare poly(styrene-co-acrylic acid)-encapsulated paraffin (paraffin@P(St-co-AA)) nanocapsules. The method could suppress the shortcomings of common miniemulsion polymerization (such as evaporation of monomer and decomposition of initiator during ultrasonication). The paraffin@P(St-co-AA) nanocapsules are uniform in size and the polymer shell can be controlled by the weight ratio of St to paraffin. The phase change behavior of the nanocapsules is similar to that of pure paraffin. We believe our method can also be utilized to synthesize other core-shell phase change materials.
The commercial development of lithium -sulfur batteries (Li -S) is severely limited by the shuttle effect of lithium polysulfides (LPSs) and the non-conductivity of sulfur. Herein, porous g-C 3 N 4 nanotubes (PCNNTs) are synthesized via a self-template method and utilized as an efficient sulfur host material. The one-dimensional PCNNTs have a high specific surface area (143.47 m 2 •g −1 ) and an abundance of macro-/mesopores, which could achieve a high sulfur loading rate of 74.7wt%. A Li-S battery bearing the PCNNTs/S composite as a cathode displays a low capacity decay of 0.021% per cycle over 800 cycles at 0.5 C with an initial capacity of 704.8 mAh•g −1 . PCNNTs with a tubular structure could alleviate the volume expansion caused by sulfur and lithium sulfide during charge/discharge cycling. High N contents could greatly enhance the adsorption capacity of the carbon nitride for LPSs. These synergistic effects contribute to the excellent cycling stability and rate performance of the PCNNTs/S composite electrode.
To improve the sulfur loading capacity of lithium-sulfur batteries (Li-S batteries) cathode and avoid the inevitable "shuttle effect", hollow N doped carbon coated CoO/SnO 2 (CoO/SnO 2 @NC) composite has been designed and prepared by a hydrothermal-calcination method. The specific surface area of CoO/SnO 2 @NC composite is 85.464 m 2 •g -1 , and the pore volume is 0.1189 cm 3 •g -1 . The hollow core-shell structure as a carrier has a sulfur loading amount of 66.10%. The initial specific capacity of the assembled Li-S batteries is 395.7 mAh•g -1 at 0.2 C, which maintains 302.7 mAh•g -1 after 400 cycles. When the rate increases to 2.5 C, the specific capacity still has 221.2 mAh•g -1 . The excellent lithium storage performance is attributed to the core-shell structure with high specific surface area and porosity. This structure effectively increases the sulfur loading, enhances the chemical adsorption of lithium polysulfides, and reduces direct contact between CoO/SnO 2 and the electrolyte.
Catalytic asymmetric hydrogenation of enamido phosphorus derivatives is one of the most efficient methods for the construction of chiral amino phosphorus products, among which the congested tetra-substituted substrates remains an unaddressed challenge. In this study, we utilize a commercially available Rh-Josiphos system for the efficient and stereoselective hydrogenation of a wide set of tetra-substituted cyclic β-enamido phosphonates/phosphine oxides, thus enabling access to chiral β-amino phosphorus compounds featuring two vicinal stereocenters. This protocol was broadly applicable to different ring systems possessing various phosphonate/phosphine oxide groups and further applied in the preparation of amino-phosphine ligands. DFT mechanistic explorations indicate that the C=C migratory insertion into Rh III À H bond could be the rateand stereo-determining step. The origins of stereoselectivity are revealed through distortion/interaction analysis, which is primarily regulated by distinguished dispersion interactions and steric repulsions.
Our goal is to investigate the connection between serum 25(OH)D and carotid artery intima-media thickness (CIMT) in men with erectile dysfunction (ED).Serum 25(OH)D and CIMT were measured in 124 participants with erectile dysfunction and 39 healthy controls. The relationship between them and different patient-related parameters and disease-related parameters was studied. Compared with the control group and mild ED group, the level of serum 25(OH)D in moderate ED group and severe ED group decreased significantly(P<0.05). The CIMT values of moderate ED group and severe ED group were higher than those of the control group(P<0.05). The CIMT value of severe ED group was significantly higher than that of mild ED group(P<0.05). IIEF-5 score was positively correlated with serum 25(OH)D level, but negatively correlated with CIMT value(P<0.05). After adjusting for the influence of confounding factors, The CIMT values, 25(OH)D and IIEF-5 score were substantially associated(P<0.05). The serum level of 25(OH)D and IIEF-5 score were positively correlated, while the CIMT values and IIEF-5 score were negatively correlated. The level of serum 25(OH)D should be analyzed in men with ED, especially in patients with vasculogenic ED, and supplementation is recommended for those who were with vitamin D deficiency.
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