[Objective]To systematically isolate and purify the polysaccharide from the mycelium of Streptomyces rochei D74(SRP),elucidate its fine structure,and evaluate the effect of the purified polysaccharide fraction on the ...[Objective]To systematically isolate and purify the polysaccharide from the mycelium of Streptomyces rochei D74(SRP),elucidate its fine structure,and evaluate the effect of the purified polysaccharide fraction on the growth of Salvia miltiorrhiza hairy roots and the biosynthesis of tanshinones,along with the underlying mechanism.[Methods]The crude polysaccharide was extracted using hot water,which was followed by ethanol precipitation and deproteinization via the Sevag method.Further purification was performed using DEAE-52 anionexchange chromatography and Sephadex G-100 gel filtration chromatography.The physicochemical properties and structural features of the main active fraction,SRP-W-2,were systematically characterized by Fourier transform infrared spectroscopy(FTIR),high performance liquid chromatography-mass spectrometry(HPLC-MS),and nuclear magnetic resonance(NMR).The effects of SRP-W-2 on hairy root growth and the biosynthesis of tanshinones were assessed by measuring biomass,tanshinone content,and the expression levels of key biosynthetic genes.[Results]SRP-W-2 was obtained with a yield of 2.41%.It was primarily composed of glucose and galactose at a molar ratio of 12.53:1.Structural analysis revealed that the backbone of SRP-W-2 consisted of→4)-α-D-Glcp-(1→and→4)-α-D-Galp-(1→residues,with branching points at→4,6)-α-D-Glcp-(1→and→4,6)-α-D-Galp-(1→.The side chain was identified asα-D-Glcp-(1→4)-α-DGlcp-(1→.Bioactivity assays demonstrated that SRP-W-2 significantly enhanced both the biomass of S.miltiorrhiza hairy roots and the accumulation of tanshinones.After 15 d of treatment with 50 mg/L SRP-W-2,the dry weight of the hairy roots increased by 37.52%.Meanwhile,the content of cryptotanshinone(CT),dihydrotanshinone I(DT-I),tanshinone I(T-I),and tanshinone IIA(TIIA)was increased by 19.0-fold,6.4-fold,2.8-fold,and 4.8-fold,respectively.Gene expression analysis further indicated that SRP-W-2 up-regulated key genes involved in the tanshinone biosynthetic pathway,including HMGR,DXS,DXR,and GGPPS.[Conclusion]The polysaccharide fraction SRP-W-2 from S.rochei D74 simultaneously promoted the growth of S.miltiorrhiza hairy roots and the biosynthesis of tanshinones,demonstrating its potential as an effective elicitor.This study provided a new strategy for the utilization and development of S.miltiorrhiza resources.展开更多
Cells actively sense and transduce microenvironmental mechanical inputs into chemical signals via cytoskeletal rearrangements.During these mechanosensation and mechanotransduction processes,the role of the actin cytos...Cells actively sense and transduce microenvironmental mechanical inputs into chemical signals via cytoskeletal rearrangements.During these mechanosensation and mechanotransduction processes,the role of the actin cytoskeleton is well-understood,whereas the role of the tubulin cytoskeleton remains largely elusive.Here,we report the dynamic changes in microtubules in response to microenvironmental stiffness during chondrocyte mitosis.Mechanical stiffness was found to be coupled with microtubule generation,directing microtubule dynamics in mitotic chondrocytes.Refilin B was found to be a key regulator of microtubule assembly in chondrocytes in response to mechanical stiffness.It was found to play its role in microtubule formation via the p-Smad3 signaling pathway.Additionally,integrin-linked kinase(ILK),triggered by mechanical stiffness,was found to play an indispensable role in the process of microtubule dynamics mediated by refilin B.Our data emphasizes stiffness-mediated dynamic changes in the microtubules of chondrocytes in a quiescent state(G0)and at anaphase,which improves our understanding of the mechanical regulation of microtubule assembly during the chondrocyte cell cycle and provides insights into microenvironment mechanics during tissue maintenance,wound healing,and disease occurrence.展开更多
Dimethylphenols serve as important intermediates in synthesizing pharmaceuticals and agrochemicals,yet traditional distillation struggles to separate their isomers due to minimal boiling point differences,and the deve...Dimethylphenols serve as important intermediates in synthesizing pharmaceuticals and agrochemicals,yet traditional distillation struggles to separate their isomers due to minimal boiling point differences,and the development of melt crystallization is hampered by lacking solid–liquid equilibrium (SLE) data for some isomers.Therefore,the SLE data of both binary and ternary mixtures of 2,3-dimethylphenol (2,3-DMP),3,5-dimethylphenol (3,5-DMP),and 3,4-dimethylphenol (3,4-DMP) were determined by using differential scanning calorimetry in this work.Additionally,crystallographic analysis was conducted to investigate the thermodynamic characteristics of these mixtures.The experimental results indicated that all the systems investigated in this research exhibited eutectic behavior.The experimentally obtained SLE data were well correlated with the Wilson and non-random two-liquid models.The excess thermodynamic functions were calculated to analyze the types and intensities of the molecular interactions occurring in the mixtures.Furthermore,this study developed a model for the correlation between the theoretical crystallization yield and the actual cooling yield and final yield in melt crystallization.This study has furnished reliable data essential for developing and optimizing the melt crystallization process of mixtures of 2,3-DMP,3,5-DMP,and 3,4-DMP.展开更多
Structural instability and sluggish lithium-ion(Li+) kinetics of spinel NiCo_(2)O_(4) anodes severely hinder their applications in high-energy-density lithium-ion batteries.Mesocrystalline structures exhibit promising...Structural instability and sluggish lithium-ion(Li+) kinetics of spinel NiCo_(2)O_(4) anodes severely hinder their applications in high-energy-density lithium-ion batteries.Mesocrystalline structures exhibit promising potential in balancing structural stability and enhancing reaction kinetics.However,their controlled synthesis mechanisms remain elusive.Herein,a substrate interface engineering strategy is developed to achieve controllable synthesis of mesocrystalline and polycrystalline NiCo_(2)O_(4) nanorods.Remarkably,mesocrystalline NiCo_(2)O_(4) exhibits a high capacity retention rate of 85.7% after 500 cycles at 2 A/g,attributed to its porous structure facilitating Li^(+) transport kinetics and unique stress-buffering effect validated by ex-situ TEM.Theoretical calculations and interfacial chemical analysis reveal that substratecrystal surface engineering regulates the nucleation-growth pathways:Acid-treated nickel foam enables epitaxial growth via lattice matching,acting as a low-interfacial-energy template to reduce nucleation barriers and promote low-temperature oriented crystallization.In contrast,carbon cloth requires hightemperature thermal activation to overcome surface diffusion barriers induced by elevated interfacial energy.This substrate-driven crystallization kinetic modulation overcomes the limitations of random nucleation in conventional hydrothermal synthesis.The established substrate-crystal interfacial interaction model not only clarifies the kinetic essence of crystal orientation regulation but also provides a universal theoretical framework for lattice-matching design and mesostructural optimization of advanced electrode materials.展开更多
Ischemic stroke is a secondary cause of mortality worldwide,imposing considerable medical and economic burdens on society.Extracellular vesicles,serving as natural nanocarriers for drug delivery,exhibit excellent bioc...Ischemic stroke is a secondary cause of mortality worldwide,imposing considerable medical and economic burdens on society.Extracellular vesicles,serving as natural nanocarriers for drug delivery,exhibit excellent biocompatibility in vivo and have significant advantages in the management of ischemic stroke.However,the uncertain distribution and rapid clearance of extracellular vesicles impede their delivery efficiency.By utilizing membrane decoration or by encapsulating therapeutic cargo within extracellular vesicles,their delivery efficacy may be greatly improved.Furthermore,previous studies have indicated that microvesicles,a subset of large-sized extracellular vesicles,can transport mitochondria to neighboring cells,thereby aiding in the restoration of mitochondrial function post-ischemic stroke.Small extracellular vesicles have also demonstrated the capability to transfer mitochondrial components,such as proteins or deoxyribonucleic acid,or their sub-components,for extracellular vesicle-based ischemic stroke therapy.In this review,we undertake a comparative analysis of the isolation techniques employed for extracellular vesicles and present an overview of the current dominant extracellular vesicle modification methodologies.Given the complex facets of treating ischemic stroke,we also delineate various extracellular vesicle modification approaches which are suited to different facets of the treatment process.Moreover,given the burgeoning interest in mitochondrial delivery,we delved into the feasibility and existing research findings on the transportation of mitochondrial fractions or intact mitochondria through small extracellular vesicles and microvesicles to offer a fresh perspective on ischemic stroke therapy.展开更多
文摘[Objective]To systematically isolate and purify the polysaccharide from the mycelium of Streptomyces rochei D74(SRP),elucidate its fine structure,and evaluate the effect of the purified polysaccharide fraction on the growth of Salvia miltiorrhiza hairy roots and the biosynthesis of tanshinones,along with the underlying mechanism.[Methods]The crude polysaccharide was extracted using hot water,which was followed by ethanol precipitation and deproteinization via the Sevag method.Further purification was performed using DEAE-52 anionexchange chromatography and Sephadex G-100 gel filtration chromatography.The physicochemical properties and structural features of the main active fraction,SRP-W-2,were systematically characterized by Fourier transform infrared spectroscopy(FTIR),high performance liquid chromatography-mass spectrometry(HPLC-MS),and nuclear magnetic resonance(NMR).The effects of SRP-W-2 on hairy root growth and the biosynthesis of tanshinones were assessed by measuring biomass,tanshinone content,and the expression levels of key biosynthetic genes.[Results]SRP-W-2 was obtained with a yield of 2.41%.It was primarily composed of glucose and galactose at a molar ratio of 12.53:1.Structural analysis revealed that the backbone of SRP-W-2 consisted of→4)-α-D-Glcp-(1→and→4)-α-D-Galp-(1→residues,with branching points at→4,6)-α-D-Glcp-(1→and→4,6)-α-D-Galp-(1→.The side chain was identified asα-D-Glcp-(1→4)-α-DGlcp-(1→.Bioactivity assays demonstrated that SRP-W-2 significantly enhanced both the biomass of S.miltiorrhiza hairy roots and the accumulation of tanshinones.After 15 d of treatment with 50 mg/L SRP-W-2,the dry weight of the hairy roots increased by 37.52%.Meanwhile,the content of cryptotanshinone(CT),dihydrotanshinone I(DT-I),tanshinone I(T-I),and tanshinone IIA(TIIA)was increased by 19.0-fold,6.4-fold,2.8-fold,and 4.8-fold,respectively.Gene expression analysis further indicated that SRP-W-2 up-regulated key genes involved in the tanshinone biosynthetic pathway,including HMGR,DXS,DXR,and GGPPS.[Conclusion]The polysaccharide fraction SRP-W-2 from S.rochei D74 simultaneously promoted the growth of S.miltiorrhiza hairy roots and the biosynthesis of tanshinones,demonstrating its potential as an effective elicitor.This study provided a new strategy for the utilization and development of S.miltiorrhiza resources.
基金supported by the National Natural Science Foundation of China(grant numbers 81771047 to J.X.,11932014,12372315 to X.L.,and 82273837 to L.S.)Sichuan Science and Technology Innovation Talent Project(2022JDRC0044)。
文摘Cells actively sense and transduce microenvironmental mechanical inputs into chemical signals via cytoskeletal rearrangements.During these mechanosensation and mechanotransduction processes,the role of the actin cytoskeleton is well-understood,whereas the role of the tubulin cytoskeleton remains largely elusive.Here,we report the dynamic changes in microtubules in response to microenvironmental stiffness during chondrocyte mitosis.Mechanical stiffness was found to be coupled with microtubule generation,directing microtubule dynamics in mitotic chondrocytes.Refilin B was found to be a key regulator of microtubule assembly in chondrocytes in response to mechanical stiffness.It was found to play its role in microtubule formation via the p-Smad3 signaling pathway.Additionally,integrin-linked kinase(ILK),triggered by mechanical stiffness,was found to play an indispensable role in the process of microtubule dynamics mediated by refilin B.Our data emphasizes stiffness-mediated dynamic changes in the microtubules of chondrocytes in a quiescent state(G0)and at anaphase,which improves our understanding of the mechanical regulation of microtubule assembly during the chondrocyte cell cycle and provides insights into microenvironment mechanics during tissue maintenance,wound healing,and disease occurrence.
基金funded by the National Natural Science Foundation of China(22308358,22208346,22421003)IPE Project for Frontier Basic Research(QYJC-2023-05)CAS Project for Young Scientists in Basic Research(YSBR-038).
文摘Dimethylphenols serve as important intermediates in synthesizing pharmaceuticals and agrochemicals,yet traditional distillation struggles to separate their isomers due to minimal boiling point differences,and the development of melt crystallization is hampered by lacking solid–liquid equilibrium (SLE) data for some isomers.Therefore,the SLE data of both binary and ternary mixtures of 2,3-dimethylphenol (2,3-DMP),3,5-dimethylphenol (3,5-DMP),and 3,4-dimethylphenol (3,4-DMP) were determined by using differential scanning calorimetry in this work.Additionally,crystallographic analysis was conducted to investigate the thermodynamic characteristics of these mixtures.The experimental results indicated that all the systems investigated in this research exhibited eutectic behavior.The experimentally obtained SLE data were well correlated with the Wilson and non-random two-liquid models.The excess thermodynamic functions were calculated to analyze the types and intensities of the molecular interactions occurring in the mixtures.Furthermore,this study developed a model for the correlation between the theoretical crystallization yield and the actual cooling yield and final yield in melt crystallization.This study has furnished reliable data essential for developing and optimizing the melt crystallization process of mixtures of 2,3-DMP,3,5-DMP,and 3,4-DMP.
基金financially supported by the National Nature Science Foundation of China (No.52401273)Science and Technology Department of Henan (Nos.242102241007,252102320178 and 252102321067)Training Program for Young Backbone Teachers in Higher Education Institutions in Henan Province (No.2024GGJS101)。
文摘Structural instability and sluggish lithium-ion(Li+) kinetics of spinel NiCo_(2)O_(4) anodes severely hinder their applications in high-energy-density lithium-ion batteries.Mesocrystalline structures exhibit promising potential in balancing structural stability and enhancing reaction kinetics.However,their controlled synthesis mechanisms remain elusive.Herein,a substrate interface engineering strategy is developed to achieve controllable synthesis of mesocrystalline and polycrystalline NiCo_(2)O_(4) nanorods.Remarkably,mesocrystalline NiCo_(2)O_(4) exhibits a high capacity retention rate of 85.7% after 500 cycles at 2 A/g,attributed to its porous structure facilitating Li^(+) transport kinetics and unique stress-buffering effect validated by ex-situ TEM.Theoretical calculations and interfacial chemical analysis reveal that substratecrystal surface engineering regulates the nucleation-growth pathways:Acid-treated nickel foam enables epitaxial growth via lattice matching,acting as a low-interfacial-energy template to reduce nucleation barriers and promote low-temperature oriented crystallization.In contrast,carbon cloth requires hightemperature thermal activation to overcome surface diffusion barriers induced by elevated interfacial energy.This substrate-driven crystallization kinetic modulation overcomes the limitations of random nucleation in conventional hydrothermal synthesis.The established substrate-crystal interfacial interaction model not only clarifies the kinetic essence of crystal orientation regulation but also provides a universal theoretical framework for lattice-matching design and mesostructural optimization of advanced electrode materials.
基金supported by the grants from University of Macao,China,Nos.MYRG2022-00221-ICMS(to YZ)and MYRG-CRG2022-00011-ICMS(to RW)the Natural Science Foundation of Guangdong Province,No.2023A1515010034(to YZ)。
文摘Ischemic stroke is a secondary cause of mortality worldwide,imposing considerable medical and economic burdens on society.Extracellular vesicles,serving as natural nanocarriers for drug delivery,exhibit excellent biocompatibility in vivo and have significant advantages in the management of ischemic stroke.However,the uncertain distribution and rapid clearance of extracellular vesicles impede their delivery efficiency.By utilizing membrane decoration or by encapsulating therapeutic cargo within extracellular vesicles,their delivery efficacy may be greatly improved.Furthermore,previous studies have indicated that microvesicles,a subset of large-sized extracellular vesicles,can transport mitochondria to neighboring cells,thereby aiding in the restoration of mitochondrial function post-ischemic stroke.Small extracellular vesicles have also demonstrated the capability to transfer mitochondrial components,such as proteins or deoxyribonucleic acid,or their sub-components,for extracellular vesicle-based ischemic stroke therapy.In this review,we undertake a comparative analysis of the isolation techniques employed for extracellular vesicles and present an overview of the current dominant extracellular vesicle modification methodologies.Given the complex facets of treating ischemic stroke,we also delineate various extracellular vesicle modification approaches which are suited to different facets of the treatment process.Moreover,given the burgeoning interest in mitochondrial delivery,we delved into the feasibility and existing research findings on the transportation of mitochondrial fractions or intact mitochondria through small extracellular vesicles and microvesicles to offer a fresh perspective on ischemic stroke therapy.
