Converting polyethylene terephthalate(PET)wastes to its monomer and valuable chemicals via ecofriendly chemical method is still a challenge task.Previously,phase transfer catalysts used for alkaline hydrolysis were so...Converting polyethylene terephthalate(PET)wastes to its monomer and valuable chemicals via ecofriendly chemical method is still a challenge task.Previously,phase transfer catalysts used for alkaline hydrolysis were soluble in reaction media and hardly separated after reaction.Here,we reported several pH-responsive catalysts combined alkyl quaternary ammonium units with heteropolyacid anion for achieving stepwise product/catalyst separation and catalyst recycling.The properties of homogeneous/heterogeneous transfer behavior allow catalyst to be easily separated from reaction media by adjusting of pH value.Among them,[C_(16)H_(33)N(CH_(3))_(3)]_(3)PW_(12)O_(40)(abbreviated as[CTA]_(3)PW)exhibits the highest activity and the most suitable pH responsive values.Such a pH triggered switchable catalytic system not only shows good performance for depolymerization of pure PET,but also some real PET wastes such as coloured trays and PE/PET complex films could be completely degraded into terephthalic acid.Additionally,the reaction kinetics and activation energy of PET alkaline hydrolysis also studied with and without pH-responsive[CTA]_(3)PW.展开更多
The conversion of carbon dioxide into valuable organic compounds is a highly promising approach to address the energy issues and environmental problems(e.g., global warming). Herein, we presents a facile and efficient...The conversion of carbon dioxide into valuable organic compounds is a highly promising approach to address the energy issues and environmental problems(e.g., global warming). Herein, we presents a facile and efficient method to prepare highly dense and well-dispersed SnO2 nanocrystals on 1 D N-doped carbon nanowires as advanced catalysts for the efficient electroreduction of CO2 to formate. The ultrasmall SnO2 coated on the N-doped carbon nanowires(SnO2@N-CNW) has been synthesized via the simple hydrothermal treatment coupled with a pyrolysis process. The unique structure enables to expose the active tin oxide and also provides the facile pathways for rapid transfer of electron and electrolyte along with the highly porous carbon foam composed with interconnected carbon nanowires. Therefore, SnO2@NCNW electrocatalyst exhibits good durability and high selectivity for formate formation with a Faradaic efficiency of ca. 90%. This work demonstrates a simple method to rationally design high-dense tin oxide nanocrystals on the conductive carbon support as advanced catalysts for CO2 electroreduction.展开更多
We present in this paper the comparison of an electric double layer(DL)in argon helicon plasma and magnetized direct current(DC)discharge plasma.DL in high-density argon helicon plasma of 13.56 MHz RF discharge was in...We present in this paper the comparison of an electric double layer(DL)in argon helicon plasma and magnetized direct current(DC)discharge plasma.DL in high-density argon helicon plasma of 13.56 MHz RF discharge was investigated experimentally by a floating electrostatic probe and local optical emission spectroscopy(LOES).The DL characteristics at different operating parameters,including RF power(300-1500 W),tube diameter(8-60 mm),and external magnetic field(0-300 G),were measured.For comparison,DL in magnetized plasma channel of a DC discharge under different conditions was also measured experimentally.The results show that in both cases,DL appears in a divergent magnetic field where the magnetic field gradient is the largest and when the plasma density is sufficiently high.DL strength(or potential drop of DL)increases with the magnetic field in two different structures.It is suggested that the electric DL should be a common phenomenon in dense plasma under a gradient external magnetic field.DL in magnetized plasmas can be controlled properly by magnetic field structure and discharge mode(hence the plasma density).展开更多
[Objectives] To establish a method for determining the content of chlorogenic acid in Wuli Huichun Wan. [Methods] The content of chlorogenic acid in Wuli Huichun Wan was determined by high performance liquid chromatog...[Objectives] To establish a method for determining the content of chlorogenic acid in Wuli Huichun Wan. [Methods] The content of chlorogenic acid in Wuli Huichun Wan was determined by high performance liquid chromatography( HPLC) combined with Agilent Eclipse Plus C18 column( 4. 6 mm × 250 mm,5 μm),in mobile phase of 0. 4% phosphoric acid solution-acetonitrile( 12∶ 88) at flow rate of1. 0 m L/min,and detection wavelength of 327 nm. [Results] The linearity of chlorogenic acid in the range of 4-48 μg injection was good( r = 1); the average recovery rate was 99. 61% and the RSD was 0. 98%. [Conclusions] The established method is simple and accurate and has high reproducibility,thus can be used as quality control method for Wuli Huichun Wan.展开更多
Pancreatic cancer(PC)is an aggressive malignant tumor with low rate of surgical resection and poor prognosis.Transforming growth factor-β(TGF-β)is a cytokine that has both protumor and antitumor activities,depending...Pancreatic cancer(PC)is an aggressive malignant tumor with low rate of surgical resection and poor prognosis.Transforming growth factor-β(TGF-β)is a cytokine that has both protumor and antitumor activities,depending on tumor microenvironment.The interaction be-tween TGF-β signaling and the tumor microenvironment in PC is complex.Here,we reviewed the role of TGF-β in the tumor microenvironment of PC,highlighting producers of TGF-β and TGF-β responders in the tumor microenvironment of PC.展开更多
基金the support of the National Natural Science Foundation of China(22005276)。
文摘Converting polyethylene terephthalate(PET)wastes to its monomer and valuable chemicals via ecofriendly chemical method is still a challenge task.Previously,phase transfer catalysts used for alkaline hydrolysis were soluble in reaction media and hardly separated after reaction.Here,we reported several pH-responsive catalysts combined alkyl quaternary ammonium units with heteropolyacid anion for achieving stepwise product/catalyst separation and catalyst recycling.The properties of homogeneous/heterogeneous transfer behavior allow catalyst to be easily separated from reaction media by adjusting of pH value.Among them,[C_(16)H_(33)N(CH_(3))_(3)]_(3)PW_(12)O_(40)(abbreviated as[CTA]_(3)PW)exhibits the highest activity and the most suitable pH responsive values.Such a pH triggered switchable catalytic system not only shows good performance for depolymerization of pure PET,but also some real PET wastes such as coloured trays and PE/PET complex films could be completely degraded into terephthalic acid.Additionally,the reaction kinetics and activation energy of PET alkaline hydrolysis also studied with and without pH-responsive[CTA]_(3)PW.
基金financially supported by Guangdong Province Science and Technology Plan Project for Public Welfare Fund and Ability Construction Project(JCYJ20180301171324915)the National Natural Science Foundation of China(No.21503116)+1 种基金Taishan Scholars Program of Shandong Province(No.tsqn20161004)the Youth 1000 Talent Program of China。
文摘The conversion of carbon dioxide into valuable organic compounds is a highly promising approach to address the energy issues and environmental problems(e.g., global warming). Herein, we presents a facile and efficient method to prepare highly dense and well-dispersed SnO2 nanocrystals on 1 D N-doped carbon nanowires as advanced catalysts for the efficient electroreduction of CO2 to formate. The ultrasmall SnO2 coated on the N-doped carbon nanowires(SnO2@N-CNW) has been synthesized via the simple hydrothermal treatment coupled with a pyrolysis process. The unique structure enables to expose the active tin oxide and also provides the facile pathways for rapid transfer of electron and electrolyte along with the highly porous carbon foam composed with interconnected carbon nanowires. Therefore, SnO2@NCNW electrocatalyst exhibits good durability and high selectivity for formate formation with a Faradaic efficiency of ca. 90%. This work demonstrates a simple method to rationally design high-dense tin oxide nanocrystals on the conductive carbon support as advanced catalysts for CO2 electroreduction.
基金supported by National Natural Science Foundation of China(No.11975047)。
文摘We present in this paper the comparison of an electric double layer(DL)in argon helicon plasma and magnetized direct current(DC)discharge plasma.DL in high-density argon helicon plasma of 13.56 MHz RF discharge was investigated experimentally by a floating electrostatic probe and local optical emission spectroscopy(LOES).The DL characteristics at different operating parameters,including RF power(300-1500 W),tube diameter(8-60 mm),and external magnetic field(0-300 G),were measured.For comparison,DL in magnetized plasma channel of a DC discharge under different conditions was also measured experimentally.The results show that in both cases,DL appears in a divergent magnetic field where the magnetic field gradient is the largest and when the plasma density is sufficiently high.DL strength(or potential drop of DL)increases with the magnetic field in two different structures.It is suggested that the electric DL should be a common phenomenon in dense plasma under a gradient external magnetic field.DL in magnetized plasmas can be controlled properly by magnetic field structure and discharge mode(hence the plasma density).
文摘[Objectives] To establish a method for determining the content of chlorogenic acid in Wuli Huichun Wan. [Methods] The content of chlorogenic acid in Wuli Huichun Wan was determined by high performance liquid chromatography( HPLC) combined with Agilent Eclipse Plus C18 column( 4. 6 mm × 250 mm,5 μm),in mobile phase of 0. 4% phosphoric acid solution-acetonitrile( 12∶ 88) at flow rate of1. 0 m L/min,and detection wavelength of 327 nm. [Results] The linearity of chlorogenic acid in the range of 4-48 μg injection was good( r = 1); the average recovery rate was 99. 61% and the RSD was 0. 98%. [Conclusions] The established method is simple and accurate and has high reproducibility,thus can be used as quality control method for Wuli Huichun Wan.
基金supported by the National Natural Science Foundation of China(22175108)the Natural Scientific Foundation of Shandong Province+1 种基金Taishan Scholars Program of Shandong Province(ZR2020JQ09 and ZR2022ZD27)Project for Scientific Research Innovation Team of Young Scholar in Colleges,Universities of Shandong Province(2019KJC025)。
基金supported by The National Natural Science Foundation of China(No.81402568)Open Fund of Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy(Three Gorges University,China)(No.2019KZL02,2020KZL03)。
文摘Pancreatic cancer(PC)is an aggressive malignant tumor with low rate of surgical resection and poor prognosis.Transforming growth factor-β(TGF-β)is a cytokine that has both protumor and antitumor activities,depending on tumor microenvironment.The interaction be-tween TGF-β signaling and the tumor microenvironment in PC is complex.Here,we reviewed the role of TGF-β in the tumor microenvironment of PC,highlighting producers of TGF-β and TGF-β responders in the tumor microenvironment of PC.
基金the National Natural Science Foundation of China (No.21503116)Taishan Scholars Program of Shandong Province (No.tsqn20161004)the Youth 1000 Talent Program of China are also acknowledged.
