The non-isothermal reduction mechanisms of pyrite cinder-carbon composite pellets were studied at laboratory scale under argon （Ar） atmosphere. The composite pellets as well as the specimens of separate layers conta...The non-isothermal reduction mechanisms of pyrite cinder-carbon composite pellets were studied at laboratory scale under argon （Ar） atmosphere. The composite pellets as well as the specimens of separate layers containing pyrite cinder and coal were tested. The degree of reduction was measured by mass loss. The microstmctures of the reduced composite pellets were characterized by scanning electron mi- croscopy （SEM）. It is found that the reduction processes of the composite pellets may be divided into four stages： reduction via CO and H2 from volatiles in coal at 673-973 K, reduction via H2 and C produced by cracking of hydrocarbon at 973-1123 K, direct reduction by carbon via gaseous intermediates at 1123-1323 K, and direct reduction by carbon at above 1323 K. Corresponding to the four stages, the apparent activation energies （E） for the reduction of the composite pellets are 86.26, 78.54, 72.01, and 203.65 kJ.mol-1, respectively.展开更多
Two new daphnicyclidin-type Daphniphyllum alkaloids,daphmacrodins A and B(1 and 2)were isolated from the leaves and stems of Daphniphyllum macropodum.Their structures were elucidated by extensive spectroscopic techniq...Two new daphnicyclidin-type Daphniphyllum alkaloids,daphmacrodins A and B(1 and 2)were isolated from the leaves and stems of Daphniphyllum macropodum.Their structures were elucidated by extensive spectroscopic techniques,including 2D NMR spectroscopy and mass spectrometry.The relative configuration of 1 was further confirmed by a single-crystal X-ray diffraction analysis.Their cytotoxic activities against five human cancer cell lines,pesticidal activities against brine shrimp(Artemia salina),and antibacterial activities against five standard bacterial and fungal strains were evaluated.The structure of 1 was successfully transformed to 2 by a chemical method.展开更多
Five new toosendanin limonoids with highly oxidative furan ring walsurobustones A-D(1-4),and one new furan ring degraded limonoid walsurobustone E(5)together with one known compound toonapubesic acid B(6)were isolated...Five new toosendanin limonoids with highly oxidative furan ring walsurobustones A-D(1-4),and one new furan ring degraded limonoid walsurobustone E(5)together with one known compound toonapubesic acid B(6)were isolated from the leaves of Walsura robusta.Their structures were elucidated by NMR and MS data.Especially,the absolute configuration of toonapubesic acid B(6)was confirmed by X-ray diffraction study.Compounds 1-6 exhibited good cytotoxicity against the cancer cell lines HL-60,SMMC-7721,A-549,MCF-7,and SW480.展开更多
In the intricate process of natural product biosynthesis,a metabolon can enhance metabolic flux by associating sequential enzymes.A fungal metabolon,comprising of flavin-dependent monooxygenase Spe F and P450 monooxyg...In the intricate process of natural product biosynthesis,a metabolon can enhance metabolic flux by associating sequential enzymes.A fungal metabolon,comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G,is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B.Using notoamide E as a substance,Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation,followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit.Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement.This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.展开更多
The activation of conventional(a)and novel(δ)protein kinase C(PKC)isoforms promotes lysosomal biogenesis,a crit-ical process for clearance of pathogenic protein aggregates including β-amyloid(Aβ)and phosphorylated ...The activation of conventional(a)and novel(δ)protein kinase C(PKC)isoforms promotes lysosomal biogenesis,a crit-ical process for clearance of pathogenic protein aggregates including β-amyloid(Aβ)and phosphorylated Tau(p-Tau)in neurodegenerative disorders.Notably,PKC activators HEP14/15,characterized by 20-methyl moiety,fail to establish classical C1 B domain pharmacophore interactions,suggesting a non-canonical activation mechanism.In this study,structural diversification of 20-deoxyingenol through esterification and acetonide protection yielded 18 new deriva-tives(2-19).Systematic screening revealed their lysosome-promoting activities,with structure-activity relationship analysis identifying compounds 4 and 18 as superior autophagy inducers.At 20 pM,these derivatives enhanced autophagic flux by 2.45-fold and 2.31-fold versus vehicle control.Moreover,compounds 4 and 18 exhibited a dose-dependent increase in lysosome numbers,promoted TFEB nuclear translocation,and enhanced lysosome-mediated lipid droplet clearance.Western blot analysis further revealed that compounds 4/18 upregulated proteins associated with the autophagy-lysosome system,suggesting their potential as promising autophagy inducers.Mechanistically,molecular docking simulations indicated thier high-affinity binding to PKCδ,which may explain their autophagy-enhancing properties.展开更多
As an emerging channel resource for modern optics,big data,internet traffic and quantum technologies,twisted photons carrying orbital angular momentum(OAM)have been extended their applicable boundary in different medi...As an emerging channel resource for modern optics,big data,internet traffic and quantum technologies,twisted photons carrying orbital angular momentum(OAM)have been extended their applicable boundary in different media,such as optical fiber and atmosphere.Due to the extreme condition of loss and pressure,underwater transmission of twisted photons has not been well investigated yet.Especially,single-photon tests were all limited at a level of a few meters,and it is in practice unclear what will happen for longer transmission distances.Here we experimentally demonstrate the transmission of single-photon twisted light over an underwater channel up to 55 m,which reach a distance allowing potential real applications.For different order OAM states and their superposition,a good preservation of modal structure and topological charge are observed.Our results for the first time reveal the real transmission performance of twisted photons in a long-distance regime,representing a step further towards OAM-based underwater quantum communication.展开更多
文摘The non-isothermal reduction mechanisms of pyrite cinder-carbon composite pellets were studied at laboratory scale under argon （Ar） atmosphere. The composite pellets as well as the specimens of separate layers containing pyrite cinder and coal were tested. The degree of reduction was measured by mass loss. The microstmctures of the reduced composite pellets were characterized by scanning electron mi- croscopy （SEM）. It is found that the reduction processes of the composite pellets may be divided into four stages： reduction via CO and H2 from volatiles in coal at 673-973 K, reduction via H2 and C produced by cracking of hydrocarbon at 973-1123 K, direct reduction by carbon via gaseous intermediates at 1123-1323 K, and direct reduction by carbon at above 1323 K. Corresponding to the four stages, the apparent activation energies （E） for the reduction of the composite pellets are 86.26, 78.54, 72.01, and 203.65 kJ.mol-1, respectively.
基金This work was financially supported by the National Natural Science Foundation of China(30830114)the National Basic Research Program of China(973 Program,2009CB522303)The Syngenta postgraduate studentship awarded to Mingming Cao(2012-2015)is appreciated.
文摘Two new daphnicyclidin-type Daphniphyllum alkaloids,daphmacrodins A and B(1 and 2)were isolated from the leaves and stems of Daphniphyllum macropodum.Their structures were elucidated by extensive spectroscopic techniques,including 2D NMR spectroscopy and mass spectrometry.The relative configuration of 1 was further confirmed by a single-crystal X-ray diffraction analysis.Their cytotoxic activities against five human cancer cell lines,pesticidal activities against brine shrimp(Artemia salina),and antibacterial activities against five standard bacterial and fungal strains were evaluated.The structure of 1 was successfully transformed to 2 by a chemical method.
基金the National Natural Science Foundation of China(U1812403 to X.-J.Hao and 22177050 to M.Cao)Project of Yunnan Characteristic Plant Screening and R&D Service CXO Platform(2022YKZY001)+1 种基金Foundation of Central Asian Drug Discovery and Development Center of Chinese Academy of Sciences(CAM202103,China)Youth Innovation Promotion Association CAS to M.Cao(2022-2026).
文摘Five new toosendanin limonoids with highly oxidative furan ring walsurobustones A-D(1-4),and one new furan ring degraded limonoid walsurobustone E(5)together with one known compound toonapubesic acid B(6)were isolated from the leaves of Walsura robusta.Their structures were elucidated by NMR and MS data.Especially,the absolute configuration of toonapubesic acid B(6)was confirmed by X-ray diffraction study.Compounds 1-6 exhibited good cytotoxicity against the cancer cell lines HL-60,SMMC-7721,A-549,MCF-7,and SW480.
基金supported by the National Natural Science Foundation of China(U1812403 to Xiao-Jiang Hao,2193304 to Yun-Dong Wu,81573323 and 31770392 to Ying-Tong Di,and 22177050 to Ming-Ming Cao)the Project of Yunnan Characteristic Plant Screening and R&D Service CXO Platform(2022YKZY001)the Yunnan Provincial Science and Technology Department(202003AD150012 to Xiao-Jiang Hao,202201AS070040 and 202302AA310035 to Ying-Tong Di)。
文摘In the intricate process of natural product biosynthesis,a metabolon can enhance metabolic flux by associating sequential enzymes.A fungal metabolon,comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G,is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B.Using notoamide E as a substance,Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation,followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit.Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement.This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.
基金supported by the Yunnan Provincial Science and Technology Department(202203AC100009 to X.J.H,202201AS070040 and 202302AA310035 to Y.T.D)the National Natural Science Foundation of China(82293683 to X.J.H,and 22177050 to M.M.C.)+4 种基金CAMS Innovation Fund for Medical Sciences(CIFMS,2021-I2M-5-004)the Open Research Fund of Yunnan Characteristic Plant Extraction Laboratory(YKKF2024005)the Project of Yunnan Characteristic Plant Screening and R&D Service CXO Platform(2022YKZY001)the Reserve Talents of Young and Middle-aged Academic and Technical Leaders in Yunnan Province(Grant NO.202105AC160044)Guizhou Provincial Science and Technology Department(QKHJC-ZK[2021]YB557).
文摘The activation of conventional(a)and novel(δ)protein kinase C(PKC)isoforms promotes lysosomal biogenesis,a crit-ical process for clearance of pathogenic protein aggregates including β-amyloid(Aβ)and phosphorylated Tau(p-Tau)in neurodegenerative disorders.Notably,PKC activators HEP14/15,characterized by 20-methyl moiety,fail to establish classical C1 B domain pharmacophore interactions,suggesting a non-canonical activation mechanism.In this study,structural diversification of 20-deoxyingenol through esterification and acetonide protection yielded 18 new deriva-tives(2-19).Systematic screening revealed their lysosome-promoting activities,with structure-activity relationship analysis identifying compounds 4 and 18 as superior autophagy inducers.At 20 pM,these derivatives enhanced autophagic flux by 2.45-fold and 2.31-fold versus vehicle control.Moreover,compounds 4 and 18 exhibited a dose-dependent increase in lysosome numbers,promoted TFEB nuclear translocation,and enhanced lysosome-mediated lipid droplet clearance.Western blot analysis further revealed that compounds 4/18 upregulated proteins associated with the autophagy-lysosome system,suggesting their potential as promising autophagy inducers.Mechanistically,molecular docking simulations indicated thier high-affinity binding to PKCδ,which may explain their autophagy-enhancing properties.
基金National Key R&D Program of China(2019YFA0308700,2017YFA0303700)the National Natural Science Foundation of China(NSFC)(11761141014,61734005,11690033)+2 种基金Science and Technology Commission of Shanghai Municipality(STCSM)(17JC1400403)Shanghai Municipal Education Commission(SMEC)(2017-01-07-00-02-E00049)Shanghai Talent Program.
文摘As an emerging channel resource for modern optics,big data,internet traffic and quantum technologies,twisted photons carrying orbital angular momentum(OAM)have been extended their applicable boundary in different media,such as optical fiber and atmosphere.Due to the extreme condition of loss and pressure,underwater transmission of twisted photons has not been well investigated yet.Especially,single-photon tests were all limited at a level of a few meters,and it is in practice unclear what will happen for longer transmission distances.Here we experimentally demonstrate the transmission of single-photon twisted light over an underwater channel up to 55 m,which reach a distance allowing potential real applications.For different order OAM states and their superposition,a good preservation of modal structure and topological charge are observed.Our results for the first time reveal the real transmission performance of twisted photons in a long-distance regime,representing a step further towards OAM-based underwater quantum communication.
