The rapid development of the“Internet+”has ushered in a new era of global digital technology innovation.Concurrent with the deepening trends of economic globalization and integration,international trade is progressi...The rapid development of the“Internet+”has ushered in a new era of global digital technology innovation.Concurrent with the deepening trends of economic globalization and integration,international trade is progressively undergoing extensive digitization,with cross-border e-commerce emerging as a significant manifestation of this transformation.Within this landscape,the cross-border e-commerce B2B platform is anticipated to become a pivotal driver for China’s cross-border trade growth,representing a strategic opportunity for trade transformation.This paper provides a comprehensive examination of the concepts,characteristics,and development status of cross-border e-commerce and B2B platforms,considering both global and Chinese perspectives.Focusing on a prominent case study,Alibaba International Station,a B2B cross-border e-commerce platform,the paper delves into its business model and core competencies,offering a thorough analysis of its role in the intricacies of international e-commerce and its contribution to the field.Drawing on insights gained,the paper concludes by presenting targeted recommendations from both the platform and government perspectives.These suggestions are informed by a nuanced understanding of the development opportunities and challenges facing China’s cross-border e-commerce B2B platforms.展开更多
Essential oil(EO)has significant antifungal activity.However,there is limited information on the mechanism of the synergistic antifungal effect of the effective components of EO against fungi.In the present study,mole...Essential oil(EO)has significant antifungal activity.However,there is limited information on the mechanism of the synergistic antifungal effect of the effective components of EO against fungi.In the present study,molecular electrostatic potential and molecular docking were used for the first time to investigate the synergistic antifungal mechanism of eugenol and citral small molecule(C_(EC))against Penicillium roqueforti.The results showed that the C_(EC)treatment made the activity ofβ-(1,3)-glucan synthase(GS)and chitin synthase(CS)decreas by 20.2%and 11.1%,respectively,and the contents of which decreased by 85.0%and 27.9%,respectively compared with the control group.Molecular docking revealed that C EC small molecules could bind to GS and CS through different amino acid residues,inhibiting their activity and synthesis.The C EC can combine with tryptophan,tyrosine,and phenylalanine in the cell membrane,causing damage to the cell membrane.The binding sites between small molecules and amino acids were mainly around the OH group.In addition,C EC affected the energy metabolism system and inhibited the glycolysis pathway.Simultaneously,C EC treatment reduced the ergosterol content in the cell membrane by 58.2%compared with the control group.Finally,changes in𝛽-galactosidase,metal ion leakage,and relative conductivity confirmed the destruction of the cell membrane,which resulted in the leakage of cell contents.The above results showed that C EC can kill P.roqueforti by inhibiting energy metabolism and destroying the integrity of the cell membrane.展开更多
The direct conversion of unactivated alkanes and cycloalkanes into structurally diverse molecules through aliphatic C—H functionalization is a useful process, which has attracted intense interest from academia and in...The direct conversion of unactivated alkanes and cycloalkanes into structurally diverse molecules through aliphatic C—H functionalization is a useful process, which has attracted intense interest from academia and industry. Methods to control chemo- and site-selectivity, combined with asymmetric catalysis, provide appealing access to high value-added enantiomer-enriched compounds but are far less developed. This review focuses on recent progress in (i) asymmetric reactions of alkanes or cycloalkanes with prochiral substrates which generate a stereocenter adjacent to the cleaved C(sp3)–H bond, and (ii) C(sp3)–H enantiodiscriminatory reactions creating a new stereogenic center on the carbon of a cleaved C(sp3)–H bond. Elegant strategies are discussed, including (a) metal carbene-induced C—H insertions by chiral rhodium catalysts, (b) metal-oxo-mediated C—H oxidation by biomimetic manganese catalysts, (c) enzyme catalysis by cytochromes P450 variants, and (d) dual catalysis by a photocatalyst and a chiral Lewis acid (CLA) or a chiral phosphoric acid (CPA). These catalytic systems can not only precisely recognize primary, secondary and tertiary C—H bonds at specific positions in alkanes and cycloalkanes, but also support a high level of stereoselectivity in the reactions. It is expected that the advances will stimulate further progress in asymmetric catalysis, synthetic methodology, pharmaceutical development and industrial processes.展开更多
文摘The rapid development of the“Internet+”has ushered in a new era of global digital technology innovation.Concurrent with the deepening trends of economic globalization and integration,international trade is progressively undergoing extensive digitization,with cross-border e-commerce emerging as a significant manifestation of this transformation.Within this landscape,the cross-border e-commerce B2B platform is anticipated to become a pivotal driver for China’s cross-border trade growth,representing a strategic opportunity for trade transformation.This paper provides a comprehensive examination of the concepts,characteristics,and development status of cross-border e-commerce and B2B platforms,considering both global and Chinese perspectives.Focusing on a prominent case study,Alibaba International Station,a B2B cross-border e-commerce platform,the paper delves into its business model and core competencies,offering a thorough analysis of its role in the intricacies of international e-commerce and its contribution to the field.Drawing on insights gained,the paper concludes by presenting targeted recommendations from both the platform and government perspectives.These suggestions are informed by a nuanced understanding of the development opportunities and challenges facing China’s cross-border e-commerce B2B platforms.
基金supported by the National Natural Science Foundation of China(32202192)Special fund for Taishan Scholars Project,and Shandong Provincial Natural Science Foundation(ZR2020MC213).
文摘Essential oil(EO)has significant antifungal activity.However,there is limited information on the mechanism of the synergistic antifungal effect of the effective components of EO against fungi.In the present study,molecular electrostatic potential and molecular docking were used for the first time to investigate the synergistic antifungal mechanism of eugenol and citral small molecule(C_(EC))against Penicillium roqueforti.The results showed that the C_(EC)treatment made the activity ofβ-(1,3)-glucan synthase(GS)and chitin synthase(CS)decreas by 20.2%and 11.1%,respectively,and the contents of which decreased by 85.0%and 27.9%,respectively compared with the control group.Molecular docking revealed that C EC small molecules could bind to GS and CS through different amino acid residues,inhibiting their activity and synthesis.The C EC can combine with tryptophan,tyrosine,and phenylalanine in the cell membrane,causing damage to the cell membrane.The binding sites between small molecules and amino acids were mainly around the OH group.In addition,C EC affected the energy metabolism system and inhibited the glycolysis pathway.Simultaneously,C EC treatment reduced the ergosterol content in the cell membrane by 58.2%compared with the control group.Finally,changes in𝛽-galactosidase,metal ion leakage,and relative conductivity confirmed the destruction of the cell membrane,which resulted in the leakage of cell contents.The above results showed that C EC can kill P.roqueforti by inhibiting energy metabolism and destroying the integrity of the cell membrane.
基金funding from the National Natural Science Foundation of China(grant nos.22071209,22071206)the National Youth Talent Support Program,the Natural Science Foundation of Fujian Province of China(grant no.2017J06006)the Fundamental Research Funds for the Central Universities(grant no.20720190048).
文摘The direct conversion of unactivated alkanes and cycloalkanes into structurally diverse molecules through aliphatic C—H functionalization is a useful process, which has attracted intense interest from academia and industry. Methods to control chemo- and site-selectivity, combined with asymmetric catalysis, provide appealing access to high value-added enantiomer-enriched compounds but are far less developed. This review focuses on recent progress in (i) asymmetric reactions of alkanes or cycloalkanes with prochiral substrates which generate a stereocenter adjacent to the cleaved C(sp3)–H bond, and (ii) C(sp3)–H enantiodiscriminatory reactions creating a new stereogenic center on the carbon of a cleaved C(sp3)–H bond. Elegant strategies are discussed, including (a) metal carbene-induced C—H insertions by chiral rhodium catalysts, (b) metal-oxo-mediated C—H oxidation by biomimetic manganese catalysts, (c) enzyme catalysis by cytochromes P450 variants, and (d) dual catalysis by a photocatalyst and a chiral Lewis acid (CLA) or a chiral phosphoric acid (CPA). These catalytic systems can not only precisely recognize primary, secondary and tertiary C—H bonds at specific positions in alkanes and cycloalkanes, but also support a high level of stereoselectivity in the reactions. It is expected that the advances will stimulate further progress in asymmetric catalysis, synthetic methodology, pharmaceutical development and industrial processes.
