Background Recombinant human endostatin （rh-endostatin, Endostar） has been proved to be an inhibitor of angiogenesis. Docetaxel has been also considered as a common chemotherapeutic agent with inhibition of angiogen...Background Recombinant human endostatin （rh-endostatin, Endostar） has been proved to be an inhibitor of angiogenesis. Docetaxel has been also considered as a common chemotherapeutic agent with inhibition of angiogenesis of malignancies. However, their function has been seldom compared and a best synergism protocol is not determined. This study aimed to compare the effects of two drugs, investigate their combined impact on human umbilical vein endothelial cells （HUVECs）, a molecular basis and find ideal protocols to inhibit endothelial cell proliferation. Methods HUVECs on confluent growth or activated by vascular endothelial growth factor （VEGF） were treated by rh-endostatin or/and docetaxel at respective gradient concentration in following operations as cell proliferation determined by MTT assay, cell cycle distribution, apoptosis and markers of CD146, CD62E and CD105 detected by flow cytometery, the structure of the channel formed by HUVECs measured by tube formation count. Results Rh-endostatin exhibited time dependent inhibition of proliferation while docetaxel showed both time and dose dependent inhibition. HUVECs accumulated in G0-G1 with decreased numbers of cells in G2 after a single treatment of rh-endostatin or that followed by docetaxel treatment. Cells accumulated in G2 after both a single docetaxel and simultaneous administration. Both the number of cells in Go-G1 and apoptotic cells were increased by docetaxel followed by rh-endostatin treatment. The number of non-apoptotic cells at Go-G1 was increased by first administering rh-endostatin then docetaxet. Sequential treatment of docetaxel followed by rh-endostatin resulted in the greatest increase in apoptosis （34.7%） and the second highest apoptosis was seen with simultaneous administration （18.2%）. Expression of CD146 and CD105 on confluent HUVECs was reduced at certain doses of rh-endostatin and/or docetaxel. However, rh-endostatin reduced CD105 without any apparent impact on either CD146 or CD62E expression, whereas these, mar展开更多
Lithium-sulfur batteries are severely restricted by low electronic conductivity of sulfur and Li_(2)S,shuttle effect,and slow conversion reaction of lithium polysulfides(LiPSs).Herein,we report a facile and highyield ...Lithium-sulfur batteries are severely restricted by low electronic conductivity of sulfur and Li_(2)S,shuttle effect,and slow conversion reaction of lithium polysulfides(LiPSs).Herein,we report a facile and highyield strategy for synthesizing dual-core single-atom catalyst(ZnCoN_(4)O_(2)/CN)with atomically dispersed nitrogen/oxygen-coordinated Zn-Co sites on carbon nanosheets.Based on density functional theory(DFT)calculations and LiPSs conversion catalytic ability,ZnCoN_(4)O_(2)/CN provides dual-atom sites of Zn and Co,which could facilitate Li^(+)transport and Li_(2)S diffusion,and catalyze LiPSs conversion more effectively than homonuclear bimetallic single-atom catalysts or their simple mixture and previously reported singleatom catalysts.Li-S cell with ZnCoN_(4)O_(2)/CN modified separator showed excellent rate performance(789.4 mA h g^(-1)at 5 C)and stable long cycle performance(0.05%capacity decay rate at 6C with 1000cycles,outperforming currently reported single atomic catalysts for LiPSs conversion.This work highlights the important role of metal active centers and provides a strategy for producing multifunctional dual-core single atom catalysts for high-performance Li-S cells.展开更多
More than 99%of the mass in the visible universe—the material that makes up ourselves,our planet,stars—is in the atomic nucleus.Although the matter has existed for billions of years,only over the past few decades ha...More than 99%of the mass in the visible universe—the material that makes up ourselves,our planet,stars—is in the atomic nucleus.Although the matter has existed for billions of years,only over the past few decades have we had the tools and the knowledge necessary to get a basic understanding of the structure and dynamic of nuclei.Nuclear physicists around the world have made tremendous strides by initiating a broad range of key展开更多
A series of non-isocyanate linear high molecular weight poly(ester urethane)s(PETUs)were prepared through an environmentallyfriendly route based on dimethyl carbonate,1,6-hexanediol and 1,6-hexanediamine.In this route...A series of non-isocyanate linear high molecular weight poly(ester urethane)s(PETUs)were prepared through an environmentallyfriendly route based on dimethyl carbonate,1,6-hexanediol and 1,6-hexanediamine.In this route,the polyurethane diol was first prepared by the reaction between bis-1,6-hexamethylencarbamate(BHC)and 1,6-hexanediol.A series of polyester soft segments of polyurethane have been synthesized from the polycondensation of adipic acid and different diols,including butanediol,hexanediol,octanediol and decanediol.The subsequent polycondensation of polyurethane diol and polyester diol led to linear PETUs.The resultant polymers were characterized by GPC,FTIR,^(1)H-NMR,^(13)C-NMR,DSC,WAXD,TGA and tensile test.The results indicated that PETUs possess weight-average molecular weights higher than 1×10^(5) and the tensile strength as high as 10 MPa.The thermal properties,crystallization behavior,microphase separation behavior and morphology were studied by DSC and AFM,and the results indicated that the degree of phase separation was affected by two factors,the crystallization and hydrogen bonding interaction between soft segment and hard segment.展开更多
The environmental effect of degraded ecosystem's vegetation restoration in low subtropical China was studied. Results indicated that the vegetation recovery on degraded lands significantly ameliorates surrounding ...The environmental effect of degraded ecosystem's vegetation restoration in low subtropical China was studied. Results indicated that the vegetation recovery on degraded lands significantly ameliorates surrounding environment, increases species diversity, improves soil structure, raises soil fertility, enhances productivity, and promotes regional agricultural production and social economic development dramatically. Through the combining engineering and biological measures, the restoration of degraded ecosystem in low subtropical area is possible and economical. The restoration experience in Xiaoliang, Wuhua and other sites are valuable for other degraded subtropical area was introduced.展开更多
文摘Background Recombinant human endostatin （rh-endostatin, Endostar） has been proved to be an inhibitor of angiogenesis. Docetaxel has been also considered as a common chemotherapeutic agent with inhibition of angiogenesis of malignancies. However, their function has been seldom compared and a best synergism protocol is not determined. This study aimed to compare the effects of two drugs, investigate their combined impact on human umbilical vein endothelial cells （HUVECs）, a molecular basis and find ideal protocols to inhibit endothelial cell proliferation. Methods HUVECs on confluent growth or activated by vascular endothelial growth factor （VEGF） were treated by rh-endostatin or/and docetaxel at respective gradient concentration in following operations as cell proliferation determined by MTT assay, cell cycle distribution, apoptosis and markers of CD146, CD62E and CD105 detected by flow cytometery, the structure of the channel formed by HUVECs measured by tube formation count. Results Rh-endostatin exhibited time dependent inhibition of proliferation while docetaxel showed both time and dose dependent inhibition. HUVECs accumulated in G0-G1 with decreased numbers of cells in G2 after a single treatment of rh-endostatin or that followed by docetaxel treatment. Cells accumulated in G2 after both a single docetaxel and simultaneous administration. Both the number of cells in Go-G1 and apoptotic cells were increased by docetaxel followed by rh-endostatin treatment. The number of non-apoptotic cells at Go-G1 was increased by first administering rh-endostatin then docetaxet. Sequential treatment of docetaxel followed by rh-endostatin resulted in the greatest increase in apoptosis （34.7%） and the second highest apoptosis was seen with simultaneous administration （18.2%）. Expression of CD146 and CD105 on confluent HUVECs was reduced at certain doses of rh-endostatin and/or docetaxel. However, rh-endostatin reduced CD105 without any apparent impact on either CD146 or CD62E expression, whereas these, mar
基金supported by the National Natural Science Foundation of P.R.China(22001082)the Applied Science and Technology Planning Project of Guangdong Province,Guangzhou,China(2017B090917002)+5 种基金the Guangdong Basic and Applied Basic Research Fund Project(2019B1515120027)the Research and Development(R&D)Projects in Key Areas of Guangdong Province(2020B0101028005)the Guangdong Natural Science Foundation Project(No.2019A1515010841)the Guangdong Province International Science and Technology Cooperation Project(No.2019A050510038)the Guangzhou Science and Technology Association Young Talents Promotion Project(X20210201043)the Guangzhou Basic and Applied Basic Research Project(202102020624)。
文摘Lithium-sulfur batteries are severely restricted by low electronic conductivity of sulfur and Li_(2)S,shuttle effect,and slow conversion reaction of lithium polysulfides(LiPSs).Herein,we report a facile and highyield strategy for synthesizing dual-core single-atom catalyst(ZnCoN_(4)O_(2)/CN)with atomically dispersed nitrogen/oxygen-coordinated Zn-Co sites on carbon nanosheets.Based on density functional theory(DFT)calculations and LiPSs conversion catalytic ability,ZnCoN_(4)O_(2)/CN provides dual-atom sites of Zn and Co,which could facilitate Li^(+)transport and Li_(2)S diffusion,and catalyze LiPSs conversion more effectively than homonuclear bimetallic single-atom catalysts or their simple mixture and previously reported singleatom catalysts.Li-S cell with ZnCoN_(4)O_(2)/CN modified separator showed excellent rate performance(789.4 mA h g^(-1)at 5 C)and stable long cycle performance(0.05%capacity decay rate at 6C with 1000cycles,outperforming currently reported single atomic catalysts for LiPSs conversion.This work highlights the important role of metal active centers and provides a strategy for producing multifunctional dual-core single atom catalysts for high-performance Li-S cells.
基金supported by the National Key R&D program of China (2016YFA0400504)the National Natural Science Foundation of China (11475014 and 11235002)
文摘More than 99%of the mass in the visible universe—the material that makes up ourselves,our planet,stars—is in the atomic nucleus.Although the matter has existed for billions of years,only over the past few decades have we had the tools and the knowledge necessary to get a basic understanding of the structure and dynamic of nuclei.Nuclear physicists around the world have made tremendous strides by initiating a broad range of key
基金the National Natural Science Foundation of China(Nos.52173009,81971711,21574137,51373186)Beijing Natural Science Foundation(No.2192065)National Key R&D Program of China(No.2016YFB1100800)。
文摘A series of non-isocyanate linear high molecular weight poly(ester urethane)s(PETUs)were prepared through an environmentallyfriendly route based on dimethyl carbonate,1,6-hexanediol and 1,6-hexanediamine.In this route,the polyurethane diol was first prepared by the reaction between bis-1,6-hexamethylencarbamate(BHC)and 1,6-hexanediol.A series of polyester soft segments of polyurethane have been synthesized from the polycondensation of adipic acid and different diols,including butanediol,hexanediol,octanediol and decanediol.The subsequent polycondensation of polyurethane diol and polyester diol led to linear PETUs.The resultant polymers were characterized by GPC,FTIR,^(1)H-NMR,^(13)C-NMR,DSC,WAXD,TGA and tensile test.The results indicated that PETUs possess weight-average molecular weights higher than 1×10^(5) and the tensile strength as high as 10 MPa.The thermal properties,crystallization behavior,microphase separation behavior and morphology were studied by DSC and AFM,and the results indicated that the degree of phase separation was affected by two factors,the crystallization and hydrogen bonding interaction between soft segment and hard segment.
文摘The environmental effect of degraded ecosystem's vegetation restoration in low subtropical China was studied. Results indicated that the vegetation recovery on degraded lands significantly ameliorates surrounding environment, increases species diversity, improves soil structure, raises soil fertility, enhances productivity, and promotes regional agricultural production and social economic development dramatically. Through the combining engineering and biological measures, the restoration of degraded ecosystem in low subtropical area is possible and economical. The restoration experience in Xiaoliang, Wuhua and other sites are valuable for other degraded subtropical area was introduced.
