The directional production of benzene is achieved by the current-enhanced catalytic conversion of lignin. The synergistic effect between catalyst and current promotes the depolymerization of lignin and the selective r...The directional production of benzene is achieved by the current-enhanced catalytic conversion of lignin. The synergistic effect between catalyst and current promotes the depolymerization of lignin and the selective recombinant of the functional groups in the aromatic monomers. A high benzene yield of 175 gbenzene/kglignin was obtained with an excellent selectivity of 92.9 C-mol%. The process potentially provides a promising route for the production of basic petrochemical materials or high value-added chemicals using renewable biomass.展开更多
A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The tran...A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The transient expression of PpMinE using green fluorescent protein fusion in tobacco （Nicotiana tabacum L.） indicated that the PpMinE was a chloroplast-targeted protein. Overexpression of PpMinE in Escherichia coli caused division site misplacement and minicell formation, suggesting evolutionary functional conservation of MinE during plant phylogenesis. According to the phylogenetic tree, PpMinE protein has a close relationship with the highland plants, which suggests that the transfer events of MinE gene from plastid to nucleus might have occurred before the origin of the land plants.展开更多
Based on a series of aqua-planet and air–sea coupled experiments,the influence of unrealistic treatment of water substance in the Flexible Global Ocean–Atmosphere–Land System Model,spectral version 2（FGOALS-s2）,o...Based on a series of aqua-planet and air–sea coupled experiments,the influence of unrealistic treatment of water substance in the Flexible Global Ocean–Atmosphere–Land System Model,spectral version 2（FGOALS-s2）,on the model＇s climate sensitivity is investigated in this paper.Because the model does not adopt an explicit microphysics scheme,the detrained water substance from the convection scheme is converted back to the humidity.This procedure could lead to an additional increase of water vapor in the atmosphere,which could strengthen the model＇s climate sensitivity.Further sensitivity experiments confirm this deduction.After removing the water vapor converted from the detrained water substance,the water vapor reduced significantly in the upper troposphere and the high clouds also reduced.Quantitative calculations show that the water vapor reduced almost 10% of the total water vapor,and 50% at 150 h Pa,when the detrained water substance was removed,contributing to the 30% atmospheric surface temperature increase.This study calls for an explicit microphysics scheme to be introduced into the model in order to handle the detrained water vapor and thus improve the model＇s simulation skill.展开更多
Hydrogen fuel cell cars are now available for lease and for sale. Renewable hydrogen fuel can be produced from water via electrolysis, or from biomass via gasification. Electrolysis is power-hungry with high demand fr...Hydrogen fuel cell cars are now available for lease and for sale. Renewable hydrogen fuel can be produced from water via electrolysis, or from biomass via gasification. Electrolysis is power-hungry with high demand from solar or wind power. Gasification, however, can be energy self-sufficient using a recently-patented thermochemical conversion technology known as I-HPG （indirectly-heated pyrolytic gasification）. I-HPG produces a tar-free syngas from non-food woody biomass. This means the balance of plant can be small, so the overall system is economical at modest sizes. This makes it possible to produce renewable hydrogen from local agricultural residues; sufficient to create distributed refueling stations wherever there is feedstock. This work describes the specifics of a novel bio-hydrogen refueling station whereby the syngas produced has much of the hydrogen extracted with the remainder powering a generator to provide the electric power to the I-HPG system. Thus the system runs continuously. When paired with another new technology, moderate-pressure storage of hydrogen in porous silicon, there is the potential to also power the refueling operation. Such systems can be operated independently. It is even possible to design an energy self-sufficient farm where all electric power, heat, and hydrogen fuel is produced from the non-food residues of agricultural operations. No water is required, and the carbon footprint is negative, or at least neutral.展开更多
The excited-state double proton transfer(ESDPT)properties of 1,5-dihydroxyanthraquinone(1,5-DHAQ)in various solvents were investigated using femtosecond transient absorption spectroscopy and the DFT/TDDFT method.The s...The excited-state double proton transfer(ESDPT)properties of 1,5-dihydroxyanthraquinone(1,5-DHAQ)in various solvents were investigated using femtosecond transient absorption spectroscopy and the DFT/TDDFT method.The steady-state fluorescence spectra in toluene,tetrahydrofuran(THF)and acetonitrile(ACN)solvents presented that the solvent polarity has an effect on the position of the ESDPT fluorescence emission peak for the 1,5-DHAQ system.Transient absorption spectra show that the increasing polarity of the solvent accelerates the rate of excited state dynamics.Calculated potential energy curves analysis further verified the experimental results.The ESDPT barrier decreases gradually with the increase of solvent polarity from toluene,THF to ACN solvent.It is convinced that the increase of solvent polarity can promote the occurrence of the ESDPT dynamic processes for the 1,5-DHAQ system.This work clarifies the mechanism of the influence of solvent polarity on the ESDPT process of 1,5-DHAQ,which provides novel ideas for design and synthesis of new hydroxyanthraquinone derivatives.展开更多
OBJECTIVE： To explore the function of Tangnai- kang （TNK） in the prevention and treatment of re- nal interstitial fibrosis through transdifferentiation of the human renal tubular epithelial cell line HK-2 induced b...OBJECTIVE： To explore the function of Tangnai- kang （TNK） in the prevention and treatment of re- nal interstitial fibrosis through transdifferentiation of the human renal tubular epithelial cell line HK-2 induced bytransforming growth factor-β1 （TGF-β1）. METHODS： HK-2 cells cultured in dulbecco＇s modi- fied eagle medium/F12 （1：1） with 10% fetal calf se- rum were divided into six groups： blank control group, TGF-β1 group （TGF-β1 10 ng/mL）, serum con- trol group （TGF-β1 10 ng/mL ＋ 10% serum）, treat- ment group 1 （TGF-β1 10 ng/mL ＋ 5% TNK serum）, treatment group 2 （TGF-β1 10 ng/mL＋10% TNK se-rum）, and treatment group 3 （TGF-β1 10 ng/mL＋ 20% TNK serum）. Cell proliferation was detected by 4,5-Dimethylthiazol-2-yl）-2,5-diphenyltetrazoliu m bromide assay. Expression of a-smooth muscle ac- tin （a-SMA） and E-cadherin were observed by im- munohistochemical assay. The contents of collagen Ⅰ （Col Ⅰ）, collagen Ⅲ（ColⅢ）, and fibronectin （FN） in the culture medium supernatant were detected by ELISA. RESULTS： E-cadherin was expressed and α-SMA was not expressed in normal HK-2 cells. In HK-2 cells cultured with TGF-β1, α-SMA expression signifi- cantly increased, HK-2 cells significantly proliferat- ed, and secretion of Col Ⅰ, Col Ⅲ, and FN significantly increased compared with the blank control group （all P〈0.05）. In the HK-2 cells cultured with TGF-β1 and TNK serum, the expression of α-SMA signifi- cantly decreased, the expression of E-cadherin sig- nificantly increased, and the cell proliferation and the secretion of Col Ⅰ, Col Ⅲ and FN were significant- ly inhibited compared with the TGF-β1 group （all P〈 0.05. CONCLUSION： TNK can inhibit cell proliferation and reduce secretion of Col Ⅰ, Col Ⅲ, and FN.This in- dicates that TNK can inhibit transdifferentiation of human renal tubular epithelial cells induced by TGF-β1, with the effect of preventing and treating renal interstitial fibrosis.展开更多
Objective： To investigate the molecular pathway of substance P （SP） to induce osteoblastic differentiation. Methods： Mesenchymal stem cells were isolated and cultured. The cultures were divided into four groups w...Objective： To investigate the molecular pathway of substance P （SP） to induce osteoblastic differentiation. Methods： Mesenchymal stem cells were isolated and cultured. The cultures were divided into four groups with Group A （control group） cultured without any factors, Group B cultured with SP, Group C cultured with SP and SP receptor neurokinin-1 （NK1） antagonist, and Group D cultured with SP NK1 antagonist respectively to induce osteoblastic cells differentiation. Osterix gene expression was detected by reverse transcription-polymerase chain reaction （RT-PCR） for three times after 1-2 weeks of cultivation and the results were analyzed by one-way analysis of variance （ANOVA）. Results： The log phase of bone marrow stromal cells appeared at 4-6 days. ALP staining revealed that the majority of cells, more than 95%, were positive and small bluepurple granules were found in the cytoplasm. And Group B, treated with SP, showed a higher level of ALP activity than the other three groups. Meanwhile, RT-PCR found that Osterix expression in Group B was obviously up-regulated, compared with other groups. But Osterix expression in Group D had no remarkable differences, compared with the controls. Conclusions： SP can up-regulate Osterix gene expression to stimulate differentiation of mesenchymal stem cells into osteoblastic cells at the final stage. The regulatory effect of SP on Osterix expression was dependant on SP NK1 receptors.展开更多
A methodology for kinetic modeling of conversion processes is presented.The proposed approach allows to overcome the lack of molecular detail of the petroleum fractions and to simulate the reactions of the process by ...A methodology for kinetic modeling of conversion processes is presented.The proposed approach allows to overcome the lack of molecular detail of the petroleum fractions and to simulate the reactions of the process by means of a two-step procedure.In the first step,a synthetic mixture of molecules representing the feedstock is generated via a molecular reconstruction method,termed SR-REM molecular reconstruction.In the second step,a kinetic Monte Carlo method,termed stochastic simulation algorithm(SSA),is used to simulate the effect of the conversion reactions on the mixture of molecules.The resulting methodology is applied to the Athabasca vacuum residue hydrocracking.An adequate molecular representation of the vacuum residue is obtained using the SR-REM algorithm.The reaction simulations present a good agreement with the laboratory data for Athabasca vacuum residue conversion.In addition,the proposed methodology provides the molecular detail of the vacuum residue conversion throughout the reactions simulations.展开更多
Recently, the spectroscopic signatures of a benzoselenadiazole derivative have been investigated in the framework of designing a new ratiometric fluoride sensor （Saravanan et al., Org Lett, 2014, 16： 354-357）. It w...Recently, the spectroscopic signatures of a benzoselenadiazole derivative have been investigated in the framework of designing a new ratiometric fluoride sensor （Saravanan et al., Org Lett, 2014, 16： 354-357）. It was suggested that this sensor is un- dergoing excited-state intramolecular proton transfer. In this work, we provide a new look at these experimental data, using a state-of-the-art time-dependent density fimctiona/theory approach to mimic the spectroscopic signatures. New insights about the nature of the excited-state processes are obtained.展开更多
Activating transcription factor 5(ATF5) is a member of the activating transcription factor/cA MP response element binding protein(ATF/CREB) family, and is highly expressed in liver and adipose tissue. Previous reports...Activating transcription factor 5(ATF5) is a member of the activating transcription factor/cA MP response element binding protein(ATF/CREB) family, and is highly expressed in liver and adipose tissue. Previous reports have shown that ATF5 promoted 3T3-L1 preadipocytes differentiation. In this study, we found that ATF5 was highly expressed in mature adipocytes, suggesting a potential role of ATF5 in mature adipocytes, which has not been reported previously. To understand the function of ATF5 in mature adipocytes, we knocked down the expression of ATF5 in 3T3-L1 mature adipocytes and observed decreased lipid droplets. Consistent with the in vitro experiment, the knockdown of ATF5 in white adipose tissue led to less adipose tissue and smaller adipocytes size. Further research revealed that the inhibition of ATF5 diminished the adipocytes size via the inhibition of fatty acid synthetase, stearyl coenzyme A desaturation enzyme 1, and the induction of carnitine palmitoyl transferase 1, one key enzyme of lipid metabolism. In addition, ATF5 knockdown in inguinal white adipose tissue improved whole body insulin sensitivity.Our work provides a new understanding of ATF5 function in mature adipocytes and a potential therapeutic target of diabetes.展开更多
文摘The directional production of benzene is achieved by the current-enhanced catalytic conversion of lignin. The synergistic effect between catalyst and current promotes the depolymerization of lignin and the selective recombinant of the functional groups in the aromatic monomers. A high benzene yield of 175 gbenzene/kglignin was obtained with an excellent selectivity of 92.9 C-mol%. The process potentially provides a promising route for the production of basic petrochemical materials or high value-added chemicals using renewable biomass.
基金This work was supported by the National Natural Science Foundation of China (No. 30470879).
文摘A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The transient expression of PpMinE using green fluorescent protein fusion in tobacco （Nicotiana tabacum L.） indicated that the PpMinE was a chloroplast-targeted protein. Overexpression of PpMinE in Escherichia coli caused division site misplacement and minicell formation, suggesting evolutionary functional conservation of MinE during plant phylogenesis. According to the phylogenetic tree, PpMinE protein has a close relationship with the highland plants, which suggests that the transfer events of MinE gene from plastid to nucleus might have occurred before the origin of the land plants.
基金jointly supported by the National Basic Research Program of China[grant number 2014CB953904]the National Natural Science Foundation of China[grant numbers 41405091 and 91337110]+1 种基金the Open Projects of the Key Laboratory of Meteorological Disaster of the Ministry of Education[grant number KLME1405]the Strategic Leading Science Projects of the Chinese Academy of Sciences[grant number XDA11010402]
文摘Based on a series of aqua-planet and air–sea coupled experiments,the influence of unrealistic treatment of water substance in the Flexible Global Ocean–Atmosphere–Land System Model,spectral version 2（FGOALS-s2）,on the model＇s climate sensitivity is investigated in this paper.Because the model does not adopt an explicit microphysics scheme,the detrained water substance from the convection scheme is converted back to the humidity.This procedure could lead to an additional increase of water vapor in the atmosphere,which could strengthen the model＇s climate sensitivity.Further sensitivity experiments confirm this deduction.After removing the water vapor converted from the detrained water substance,the water vapor reduced significantly in the upper troposphere and the high clouds also reduced.Quantitative calculations show that the water vapor reduced almost 10% of the total water vapor,and 50% at 150 h Pa,when the detrained water substance was removed,contributing to the 30% atmospheric surface temperature increase.This study calls for an explicit microphysics scheme to be introduced into the model in order to handle the detrained water vapor and thus improve the model＇s simulation skill.
文摘Hydrogen fuel cell cars are now available for lease and for sale. Renewable hydrogen fuel can be produced from water via electrolysis, or from biomass via gasification. Electrolysis is power-hungry with high demand from solar or wind power. Gasification, however, can be energy self-sufficient using a recently-patented thermochemical conversion technology known as I-HPG （indirectly-heated pyrolytic gasification）. I-HPG produces a tar-free syngas from non-food woody biomass. This means the balance of plant can be small, so the overall system is economical at modest sizes. This makes it possible to produce renewable hydrogen from local agricultural residues; sufficient to create distributed refueling stations wherever there is feedstock. This work describes the specifics of a novel bio-hydrogen refueling station whereby the syngas produced has much of the hydrogen extracted with the remainder powering a generator to provide the electric power to the I-HPG system. Thus the system runs continuously. When paired with another new technology, moderate-pressure storage of hydrogen in porous silicon, there is the potential to also power the refueling operation. Such systems can be operated independently. It is even possible to design an energy self-sufficient farm where all electric power, heat, and hydrogen fuel is produced from the non-food residues of agricultural operations. No water is required, and the carbon footprint is negative, or at least neutral.
基金supported by the National Basic Research Program of China(No.2019YFA0307701)the National Natural Science Foundation of China(No.11874180)the Young and Middle-aged Scientific and Technological Innovation leaders and Team Projects in Jilin Province(No.20200301020RQ)。
文摘The excited-state double proton transfer(ESDPT)properties of 1,5-dihydroxyanthraquinone(1,5-DHAQ)in various solvents were investigated using femtosecond transient absorption spectroscopy and the DFT/TDDFT method.The steady-state fluorescence spectra in toluene,tetrahydrofuran(THF)and acetonitrile(ACN)solvents presented that the solvent polarity has an effect on the position of the ESDPT fluorescence emission peak for the 1,5-DHAQ system.Transient absorption spectra show that the increasing polarity of the solvent accelerates the rate of excited state dynamics.Calculated potential energy curves analysis further verified the experimental results.The ESDPT barrier decreases gradually with the increase of solvent polarity from toluene,THF to ACN solvent.It is convinced that the increase of solvent polarity can promote the occurrence of the ESDPT dynamic processes for the 1,5-DHAQ system.This work clarifies the mechanism of the influence of solvent polarity on the ESDPT process of 1,5-DHAQ,which provides novel ideas for design and synthesis of new hydroxyanthraquinone derivatives.
基金Project supported by the China Scholarship Council(No.201806320236)the Zhejiang University Academic Award for Outstanding Doctoral Candidates(No.2018071)the Ningxia Provincial Key Research and Development Program of China(No.2018BCE01004)
基金Supported by the National Natural Science Fund(30973909)Innovation Group Items of Beijing University of Traditional Chinese Medicine(No.2011-CXTD-19)
文摘OBJECTIVE： To explore the function of Tangnai- kang （TNK） in the prevention and treatment of re- nal interstitial fibrosis through transdifferentiation of the human renal tubular epithelial cell line HK-2 induced bytransforming growth factor-β1 （TGF-β1）. METHODS： HK-2 cells cultured in dulbecco＇s modi- fied eagle medium/F12 （1：1） with 10% fetal calf se- rum were divided into six groups： blank control group, TGF-β1 group （TGF-β1 10 ng/mL）, serum con- trol group （TGF-β1 10 ng/mL ＋ 10% serum）, treat- ment group 1 （TGF-β1 10 ng/mL ＋ 5% TNK serum）, treatment group 2 （TGF-β1 10 ng/mL＋10% TNK se-rum）, and treatment group 3 （TGF-β1 10 ng/mL＋ 20% TNK serum）. Cell proliferation was detected by 4,5-Dimethylthiazol-2-yl）-2,5-diphenyltetrazoliu m bromide assay. Expression of a-smooth muscle ac- tin （a-SMA） and E-cadherin were observed by im- munohistochemical assay. The contents of collagen Ⅰ （Col Ⅰ）, collagen Ⅲ（ColⅢ）, and fibronectin （FN） in the culture medium supernatant were detected by ELISA. RESULTS： E-cadherin was expressed and α-SMA was not expressed in normal HK-2 cells. In HK-2 cells cultured with TGF-β1, α-SMA expression signifi- cantly increased, HK-2 cells significantly proliferat- ed, and secretion of Col Ⅰ, Col Ⅲ, and FN significantly increased compared with the blank control group （all P〈0.05）. In the HK-2 cells cultured with TGF-β1 and TNK serum, the expression of α-SMA signifi- cantly decreased, the expression of E-cadherin sig- nificantly increased, and the cell proliferation and the secretion of Col Ⅰ, Col Ⅲ and FN were significant- ly inhibited compared with the TGF-β1 group （all P〈 0.05. CONCLUSION： TNK can inhibit cell proliferation and reduce secretion of Col Ⅰ, Col Ⅲ, and FN.This in- dicates that TNK can inhibit transdifferentiation of human renal tubular epithelial cells induced by TGF-β1, with the effect of preventing and treating renal interstitial fibrosis.
文摘Objective： To investigate the molecular pathway of substance P （SP） to induce osteoblastic differentiation. Methods： Mesenchymal stem cells were isolated and cultured. The cultures were divided into four groups with Group A （control group） cultured without any factors, Group B cultured with SP, Group C cultured with SP and SP receptor neurokinin-1 （NK1） antagonist, and Group D cultured with SP NK1 antagonist respectively to induce osteoblastic cells differentiation. Osterix gene expression was detected by reverse transcription-polymerase chain reaction （RT-PCR） for three times after 1-2 weeks of cultivation and the results were analyzed by one-way analysis of variance （ANOVA）. Results： The log phase of bone marrow stromal cells appeared at 4-6 days. ALP staining revealed that the majority of cells, more than 95%, were positive and small bluepurple granules were found in the cytoplasm. And Group B, treated with SP, showed a higher level of ALP activity than the other three groups. Meanwhile, RT-PCR found that Osterix expression in Group B was obviously up-regulated, compared with other groups. But Osterix expression in Group D had no remarkable differences, compared with the controls. Conclusions： SP can up-regulate Osterix gene expression to stimulate differentiation of mesenchymal stem cells into osteoblastic cells at the final stage. The regulatory effect of SP on Osterix expression was dependant on SP NK1 receptors.
文摘A methodology for kinetic modeling of conversion processes is presented.The proposed approach allows to overcome the lack of molecular detail of the petroleum fractions and to simulate the reactions of the process by means of a two-step procedure.In the first step,a synthetic mixture of molecules representing the feedstock is generated via a molecular reconstruction method,termed SR-REM molecular reconstruction.In the second step,a kinetic Monte Carlo method,termed stochastic simulation algorithm(SSA),is used to simulate the effect of the conversion reactions on the mixture of molecules.The resulting methodology is applied to the Athabasca vacuum residue hydrocracking.An adequate molecular representation of the vacuum residue is obtained using the SR-REM algorithm.The reaction simulations present a good agreement with the laboratory data for Athabasca vacuum residue conversion.In addition,the proposed methodology provides the molecular detail of the vacuum residue conversion throughout the reactions simulations.
基金D.Jacquemm acknowledges the European Research Council(ERC)the Règion des Pays de la Loire for financial support in the framework of a Starting Grant(Marches-278845)a recrutement sur poste stratègique,respectively
文摘Recently, the spectroscopic signatures of a benzoselenadiazole derivative have been investigated in the framework of designing a new ratiometric fluoride sensor （Saravanan et al., Org Lett, 2014, 16： 354-357）. It was suggested that this sensor is un- dergoing excited-state intramolecular proton transfer. In this work, we provide a new look at these experimental data, using a state-of-the-art time-dependent density fimctiona/theory approach to mimic the spectroscopic signatures. New insights about the nature of the excited-state processes are obtained.
基金supported by the National Key Basic Research Project (2013CB530601 to X. Li)the National Natural Science Foundation of China (81270954, 31571401 to X. Li)
文摘Activating transcription factor 5(ATF5) is a member of the activating transcription factor/cA MP response element binding protein(ATF/CREB) family, and is highly expressed in liver and adipose tissue. Previous reports have shown that ATF5 promoted 3T3-L1 preadipocytes differentiation. In this study, we found that ATF5 was highly expressed in mature adipocytes, suggesting a potential role of ATF5 in mature adipocytes, which has not been reported previously. To understand the function of ATF5 in mature adipocytes, we knocked down the expression of ATF5 in 3T3-L1 mature adipocytes and observed decreased lipid droplets. Consistent with the in vitro experiment, the knockdown of ATF5 in white adipose tissue led to less adipose tissue and smaller adipocytes size. Further research revealed that the inhibition of ATF5 diminished the adipocytes size via the inhibition of fatty acid synthetase, stearyl coenzyme A desaturation enzyme 1, and the induction of carnitine palmitoyl transferase 1, one key enzyme of lipid metabolism. In addition, ATF5 knockdown in inguinal white adipose tissue improved whole body insulin sensitivity.Our work provides a new understanding of ATF5 function in mature adipocytes and a potential therapeutic target of diabetes.
