Hepatitis B virus X protein (HBx) plays a crucial role in the development of hepatocellular carcinoma. Here, we sought to identify the mechanisms by which HBx mediates liver cell proliferation. We found that HBx upr...Hepatitis B virus X protein (HBx) plays a crucial role in the development of hepatocellular carcinoma. Here, we sought to identify the mechanisms by which HBx mediates liver cell proliferation. We found that HBx upregulated the levels of cyclooxygenase-2 (COX-2), 5-1ipoxygenase (5-LOX) and phosphorylated extracellular signal-regulated protein kinases 1/2 (p-ERK1/2) in liver cells. HBx-induced p-ERK1/2 was abolished by inhibition of Gi/o proteins, COX or LOX. In addition, HBx increased the amounts of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) released from cell lines derived from hepatocytes. Moreover, these released arachidonic acid metabolites were able to activate ERK1/2. Interestingly, activated ERK1/2 could upregulate the expression of COX-2 and 5-LOX in a positive feedback manner. In conclusion, HBx enhances and maintains liver cell proliferation via a positive feedback loop involving COX-2, 5-LOX, released arachidonic acid metabolites, Gi/o proteins and p-ERK1/2.展开更多
To investigate the configuration consideration of expander in transcritical carbon dioxide two-stage compression cycle, the best place in the cycle should be searched for to reinvest the recovery work so as to improve...To investigate the configuration consideration of expander in transcritical carbon dioxide two-stage compression cycle, the best place in the cycle should be searched for to reinvest the recovery work so as to improve the system efficiency. The expander and the compressor are connected to the same shaft and integrated into one unit, with the latter being driven by the former, thus the transfer loss and leakage loss can be decreased greatly. In these systems, the expander can be either connected with the first stage compressor (shortened as DCDL cycle) or the second stage compressor (shortened as DCDH cycle), but the two configuration ways can get different performances. By setting up theoretical model for two kinds of expander configuration ways in the transcritical carbon dioxide two-stage compression cycle, the first and the second laws of thermodynamics are used to analyze the coefficient of performance, exergy efficiency, inter-stage pressure, discharge temperature and exergy losses of each component for the two cycles. From the model results, the performance of DCDH cycle is better than that of DCDL cycle. The analysis results are indispensable to providing a theoretical basis for practical design and operating.展开更多
The epoxidation of methyl oleate(MO)was conducted in the presence of aqueous H2O2 as the oxidant and hierarchical TS-1(HTS-1)as the catalyst;the catalyst was synthesized using polyquaternium-6 as the mesopore template...The epoxidation of methyl oleate(MO)was conducted in the presence of aqueous H2O2 as the oxidant and hierarchical TS-1(HTS-1)as the catalyst;the catalyst was synthesized using polyquaternium-6 as the mesopore template.The effects of various parameters,i.e.,H2O2/C=C molar ratio,oxidant concentration,amount of the catalyst,reaction temperature,and time,were systematically studied.Furthermore,response surface methodology(RSM)was used to optimize the conditions to maximize the yield of epoxy MO and to evaluate the significance and interplay of the factors affecting the epoxy MO production.The H2O2/C=C molar ratio and catalyst amount were the determining factors for MO epoxidation,wherein the maximum yield of epoxy MO reached 94.9%over HTS-1 under the optimal conditions.展开更多
Activated carbon (AC) was fabricated by Coconut shell as carbon source, KOH as activator. Cyclic voltammetry and galvanostatic charge-discharge were used to characterize the electrochemical performance of the sample...Activated carbon (AC) was fabricated by Coconut shell as carbon source, KOH as activator. Cyclic voltammetry and galvanostatic charge-discharge were used to characterize the electrochemical performance of the samples. The results showed that: Supercapacitors based on the sample AC-3 have low Equivalent series resistanceb (ESR) and excellent power property.展开更多
Long-term cycling stability of pseudocapacitive materials is pursued for high-energy supercapacitors.Herein,the mesoporous zinc-cobalt oxide heterostructure@nitrogendoped carbon(ZnO-CoO@NC)microspheres with abundant o...Long-term cycling stability of pseudocapacitive materials is pursued for high-energy supercapacitors.Herein,the mesoporous zinc-cobalt oxide heterostructure@nitrogendoped carbon(ZnO-CoO@NC)microspheres with abundant oxygen vacancies are self-assembled through a hydrothermal method combined with an annealing post-treatment.The multifunctional polyvinyl pyrrolidone(PVP)is used as a structure-directing agent,the precursor of NC and the initiator of abundant oxygen vacancies in zinc-cobalt oxide microspheres.XPS demonstrates the generation of surface oxygen vacancies resulted from the reduction effect of conductive NC,and further confirms the weaker interaction between the metal ions and oxygen atoms.As a result,the electrode based on ZnO-CoO@NC in 2 mol L^-1 KOH shows enhanced capacitive performance with an excellent cycle stability of 92%retention of the initial capacitance after 40,000 charge-discharge cycles at 2 A g^-1,keeping the morphology unchanged.The assembled asymmetric supercapacitor,graphene//ZnO-CoO@NC,also performs good cyclic stability with 94%capacitance retention after 10,000 cycles at 2 A g^-1.The remarkable electrochemical performance of the self-assembled ZnO-CoO@NC composite is attributed to the mesoporous architecture,abundant oxygen vacancies,conductive ZnO scaffold for CoO crystals forming heterostructure of ZnO-CoO and the high conductive NC layer covering outside of the multi-metal oxide nanoparticles.Hence,the ZnO-CoO@NC holds great promise for high-performance energy storage applications.展开更多
文摘Hepatitis B virus X protein (HBx) plays a crucial role in the development of hepatocellular carcinoma. Here, we sought to identify the mechanisms by which HBx mediates liver cell proliferation. We found that HBx upregulated the levels of cyclooxygenase-2 (COX-2), 5-1ipoxygenase (5-LOX) and phosphorylated extracellular signal-regulated protein kinases 1/2 (p-ERK1/2) in liver cells. HBx-induced p-ERK1/2 was abolished by inhibition of Gi/o proteins, COX or LOX. In addition, HBx increased the amounts of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) released from cell lines derived from hepatocytes. Moreover, these released arachidonic acid metabolites were able to activate ERK1/2. Interestingly, activated ERK1/2 could upregulate the expression of COX-2 and 5-LOX in a positive feedback manner. In conclusion, HBx enhances and maintains liver cell proliferation via a positive feedback loop involving COX-2, 5-LOX, released arachidonic acid metabolites, Gi/o proteins and p-ERK1/2.
文摘To investigate the configuration consideration of expander in transcritical carbon dioxide two-stage compression cycle, the best place in the cycle should be searched for to reinvest the recovery work so as to improve the system efficiency. The expander and the compressor are connected to the same shaft and integrated into one unit, with the latter being driven by the former, thus the transfer loss and leakage loss can be decreased greatly. In these systems, the expander can be either connected with the first stage compressor (shortened as DCDL cycle) or the second stage compressor (shortened as DCDH cycle), but the two configuration ways can get different performances. By setting up theoretical model for two kinds of expander configuration ways in the transcritical carbon dioxide two-stage compression cycle, the first and the second laws of thermodynamics are used to analyze the coefficient of performance, exergy efficiency, inter-stage pressure, discharge temperature and exergy losses of each component for the two cycles. From the model results, the performance of DCDH cycle is better than that of DCDL cycle. The analysis results are indispensable to providing a theoretical basis for practical design and operating.
基金supported by the Evonik Industries AGthe Program for New Century Excellent Talents in University(NCET-04-0270)~~
文摘The epoxidation of methyl oleate(MO)was conducted in the presence of aqueous H2O2 as the oxidant and hierarchical TS-1(HTS-1)as the catalyst;the catalyst was synthesized using polyquaternium-6 as the mesopore template.The effects of various parameters,i.e.,H2O2/C=C molar ratio,oxidant concentration,amount of the catalyst,reaction temperature,and time,were systematically studied.Furthermore,response surface methodology(RSM)was used to optimize the conditions to maximize the yield of epoxy MO and to evaluate the significance and interplay of the factors affecting the epoxy MO production.The H2O2/C=C molar ratio and catalyst amount were the determining factors for MO epoxidation,wherein the maximum yield of epoxy MO reached 94.9%over HTS-1 under the optimal conditions.
文摘Activated carbon (AC) was fabricated by Coconut shell as carbon source, KOH as activator. Cyclic voltammetry and galvanostatic charge-discharge were used to characterize the electrochemical performance of the samples. The results showed that: Supercapacitors based on the sample AC-3 have low Equivalent series resistanceb (ESR) and excellent power property.
基金supported by the National Natural Science Foundation of China (21576138 and 51572127)China-Israel Cooperative Program (2016YFE0129900)+2 种基金the Program Foundation for Science and Technology of Changzhou, China (CZ20190001)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Program for Science and Technology Innovative Research Team in the Universities of Jiangsu Province, China
文摘Long-term cycling stability of pseudocapacitive materials is pursued for high-energy supercapacitors.Herein,the mesoporous zinc-cobalt oxide heterostructure@nitrogendoped carbon(ZnO-CoO@NC)microspheres with abundant oxygen vacancies are self-assembled through a hydrothermal method combined with an annealing post-treatment.The multifunctional polyvinyl pyrrolidone(PVP)is used as a structure-directing agent,the precursor of NC and the initiator of abundant oxygen vacancies in zinc-cobalt oxide microspheres.XPS demonstrates the generation of surface oxygen vacancies resulted from the reduction effect of conductive NC,and further confirms the weaker interaction between the metal ions and oxygen atoms.As a result,the electrode based on ZnO-CoO@NC in 2 mol L^-1 KOH shows enhanced capacitive performance with an excellent cycle stability of 92%retention of the initial capacitance after 40,000 charge-discharge cycles at 2 A g^-1,keeping the morphology unchanged.The assembled asymmetric supercapacitor,graphene//ZnO-CoO@NC,also performs good cyclic stability with 94%capacitance retention after 10,000 cycles at 2 A g^-1.The remarkable electrochemical performance of the self-assembled ZnO-CoO@NC composite is attributed to the mesoporous architecture,abundant oxygen vacancies,conductive ZnO scaffold for CoO crystals forming heterostructure of ZnO-CoO and the high conductive NC layer covering outside of the multi-metal oxide nanoparticles.Hence,the ZnO-CoO@NC holds great promise for high-performance energy storage applications.