Organic Rankine cycle(ORC) is applicable for the heat-work conversion. Whereas, there also exist a lot issues that influence the efficiency and the cost of the system. In this work, eleven pure working fluids(as categ...Organic Rankine cycle(ORC) is applicable for the heat-work conversion. Whereas, there also exist a lot issues that influence the efficiency and the cost of the system. In this work, eleven pure working fluids(as categorized into alkanes, and fluorinated alkanes) are investigated based on the first and second law of thermodynamics. The major objective is to obtain the most suitable working fluid for the latent heat source. The results show that the working fluid is an important factor of the system performance. The heat absorption of the working fluid in the evaporator is inversely proportional to the evaporating temperature, but the thermal and exergetic efficiencies are just the opposite. RC318 has the highest net power output and the lowest outlet temperature of the heat source, but its global warming potential(GWP) value is too high. The cyclohexane shows the highest thermal efficiency among the fluids investigated. Moreover, the figure of merit(FOM) of the isobutane is higher than that of other working fluids. Overall, the cyclohexane shows that the optimal comprehensive performance is more feasible for medium grade heat source in engineering applications.展开更多
OBJECTIVE Cytochrome P450(CYP)2J2 is highly expressed in many kinds of human tumors and promotes tumor cell growth via regulating the metabolism of arachidonic acids.The purposes of this study were toidentify the new ...OBJECTIVE Cytochrome P450(CYP)2J2 is highly expressed in many kinds of human tumors and promotes tumor cell growth via regulating the metabolism of arachidonic acids.The purposes of this study were toidentify the new inhibitor of CYP2J2 from natural compounds and evaluate its potential to inhibit hepatoma carcinoma cells.METHODS Total fifty natural products were screened for the inhibitory potency against the activity of CYP2J2-mediated astemizole O-demethylation via LCMS/MS analysis.Enzyme kinetic and molecular docking studies were also carried out.RESULTS Our data found that plumbagin potently inhibited CYP2J2 with IC50value at 3.42,3.37 and 1.17μmol·L-1in rat liver microsomes,human liver microsomes(HLMs)and recombinant CYP2J2(rC YP2J2),respectively.Further enzyme kinetic studies showed that plumbagin was a mixed-type inhibitor of CYP2J2 in HLMs and r CYP2J2 with Kivalues of 1.88and 0.92μmol·L-1,respectively.Docking data presented that plumbagin interacted with CYP2J2 mainly through GLU222 and ALA223,which were crucial residues for substrates binding.At the same time,plumbagin showed cytotoxicity effects on hepatic carcinoma cell lines,such as HepG 2 and SMMC-7721,with IC50values at 11.55±1.06and(13.15±1.11)μmol·L-1,respectively.CONCLUSION These results indicated that plumbagin was a potent CYP2J2 inhibitor and potential anticancer agent.Further studies are needed to cover the mechanism of its antitumor activity.展开更多
基金Project(51406130) supported by the National Natural Science Foundation of China
文摘Organic Rankine cycle(ORC) is applicable for the heat-work conversion. Whereas, there also exist a lot issues that influence the efficiency and the cost of the system. In this work, eleven pure working fluids(as categorized into alkanes, and fluorinated alkanes) are investigated based on the first and second law of thermodynamics. The major objective is to obtain the most suitable working fluid for the latent heat source. The results show that the working fluid is an important factor of the system performance. The heat absorption of the working fluid in the evaporator is inversely proportional to the evaporating temperature, but the thermal and exergetic efficiencies are just the opposite. RC318 has the highest net power output and the lowest outlet temperature of the heat source, but its global warming potential(GWP) value is too high. The cyclohexane shows the highest thermal efficiency among the fluids investigated. Moreover, the figure of merit(FOM) of the isobutane is higher than that of other working fluids. Overall, the cyclohexane shows that the optimal comprehensive performance is more feasible for medium grade heat source in engineering applications.
基金The project supported by National Natural Science Foundation of China(81301908)the Science and Technology Commission of Shanghai Municipality(15140904700,13ZR1412600 and 14DZ2270100)
文摘OBJECTIVE Cytochrome P450(CYP)2J2 is highly expressed in many kinds of human tumors and promotes tumor cell growth via regulating the metabolism of arachidonic acids.The purposes of this study were toidentify the new inhibitor of CYP2J2 from natural compounds and evaluate its potential to inhibit hepatoma carcinoma cells.METHODS Total fifty natural products were screened for the inhibitory potency against the activity of CYP2J2-mediated astemizole O-demethylation via LCMS/MS analysis.Enzyme kinetic and molecular docking studies were also carried out.RESULTS Our data found that plumbagin potently inhibited CYP2J2 with IC50value at 3.42,3.37 and 1.17μmol·L-1in rat liver microsomes,human liver microsomes(HLMs)and recombinant CYP2J2(rC YP2J2),respectively.Further enzyme kinetic studies showed that plumbagin was a mixed-type inhibitor of CYP2J2 in HLMs and r CYP2J2 with Kivalues of 1.88and 0.92μmol·L-1,respectively.Docking data presented that plumbagin interacted with CYP2J2 mainly through GLU222 and ALA223,which were crucial residues for substrates binding.At the same time,plumbagin showed cytotoxicity effects on hepatic carcinoma cell lines,such as HepG 2 and SMMC-7721,with IC50values at 11.55±1.06and(13.15±1.11)μmol·L-1,respectively.CONCLUSION These results indicated that plumbagin was a potent CYP2J2 inhibitor and potential anticancer agent.Further studies are needed to cover the mechanism of its antitumor activity.
