The viscoelastic micelle systems formed by novel anionic-nonionic dimeric surfactant and conventional cationic surfactant cetyltrimethylammonium(1631) were studied.The viscoelasticity,thixotropy,flow curves and consti...The viscoelastic micelle systems formed by novel anionic-nonionic dimeric surfactant and conventional cationic surfactant cetyltrimethylammonium(1631) were studied.The viscoelasticity,thixotropy,flow curves and constitutive equation for the novel viscoelastic micelle systems were investigated.The results show that the micelle systems possess viscoelasticity,thixotropy,and shear thinning property.Some micelle systems possess hysteresis loops showing both viscoelasticity and thixotropy.It is proved that the flow curves are characterized by the co-rotational Jeffreys constitutive equation correctly.展开更多
Alzheimer disease(AD) has now become the most common brain disorder among the older population. In addition, the currently existing therapeutics only offer temporary symptomatic relieves. Therefore, further research a...Alzheimer disease(AD) has now become the most common brain disorder among the older population. In addition, the currently existing therapeutics only offer temporary symptomatic relieves. Therefore, further research and development of more efficacious and disease-modifying agents for the prevention, treatment and restoration of AD will have tremendous value from both scientific, and economic standpoints. Over the past few years, our series of studies have identified several highly promising anti-AD dimeric leads, with disease-modifying potentials. In this presentation, the latest progress on the neuroprotective and disease modifying effects and the underlying mechanisms of those candidates will be comprehensively illustrated and discussed.展开更多
本文介绍了采用无格点Kinetic Monte Carlo(KMC)方法,模拟TiN薄膜在TiN(001)基底表面上外延生长的仿真结果。在此无格点KMC方法中,使用了Dimer算法在势能面中搜索鞍点和低能盆底。仿真的结果证实,此无格点KMC方法对于仿真二元薄膜外延...本文介绍了采用无格点Kinetic Monte Carlo(KMC)方法,模拟TiN薄膜在TiN(001)基底表面上外延生长的仿真结果。在此无格点KMC方法中,使用了Dimer算法在势能面中搜索鞍点和低能盆底。仿真的结果证实,此无格点KMC方法对于仿真二元薄膜外延生长是有效的。本文中还讨论了无格点KMC的计算量问题、运算过程中Dimer的初始位置问题和势能面中浅盆底问题。展开更多
Erythropoietin (EPO), a 34 kD glycopro-tein, is the principal growth factor regulating theproduction of circulating erythrocytes; EPO isessential for committed CFU - E erythroid pro-genitors to divide several times an...Erythropoietin (EPO), a 34 kD glycopro-tein, is the principal growth factor regulating theproduction of circulating erythrocytes; EPO isessential for committed CFU - E erythroid pro-genitors to divide several times and then to dif-ferentiate into erythrocytes. Like most receptorsfor hematopoietic growth factors, the erythro-poietin receptor (EPO - R) is a type I trans-membrane protein and a member of the cytokinereceptor superfamily. These receptors containfour conserved cysteines and a Trp - Ser - X -展开更多
The Aux/IAA genes are rapidly and specificallyinduced by the plant hormone auxin and encodeshort-lived nuclear proteins that are capable offorming homo-and hetero-dimer.Molecular,biochemical,and genetic data suggest t...The Aux/IAA genes are rapidly and specificallyinduced by the plant hormone auxin and encodeshort-lived nuclear proteins that are capable offorming homo-and hetero-dimer.Molecular,biochemical,and genetic data suggest that theyplay a central role in auxin signaling and plantdevelopment.In order to investigate展开更多
OBJECTIVE Hepatocellular carcinoma(HCC)is the fifth most common malignancy worldwide and the third cause of global cancer mortality.Activation of signal transducer and activator of transcription 3(STAT3)is commonly ob...OBJECTIVE Hepatocellular carcinoma(HCC)is the fifth most common malignancy worldwide and the third cause of global cancer mortality.Activation of signal transducer and activator of transcription 3(STAT3)is commonly observed in tumor cells and is a critical mediator of on cogenic signaling in HCC and controls the expression of several genes involved in proliferation,survival,metastasis and angiogenesis.Current drug-targeted therapies,besides being expensive,are associated with serious side effects and morbidity.Thus,novel agents that can suppress STAT3 activation have potential for both prevention and treatment of HCC.In the present report,we investigated whether the potent HAT/KAT inhibitor,garcinol,(apolyisoprenylatedbenzophenone),could suppress STAT3 activation in HCC cells and in nude mice model.METHODS The effect of garcinol on HCC cell lines wasdetermined by MTT assay,immunoblotting,DNA binding assays,immuno-fluorescenceand immune-histochemical analysis.The effect of garcinolon the inhibition of tumor growth in vivo was also investigated using HCCxenograft tumor modelin athymic nu/nu mice.RESULTS We found that garcinol could inhibit constitutive STAT3 activation in a dose-and time-dependent manner both by inhibiting STAT3 phosphorylation and acetylation in HCC cells.When investigated for molecular mechanism(s),we found that garcinol interferes with the dimer formation of STAT3 thereby inhibits its nuclear localization.Computational modeling showed that garcinol could bind to the SH2 domain of STAT3 and suppresses its dimerization in vitro.To understand the cellular mechanism(s)of inhibition of STAT3 function by garcinol,we observed that upon inhibition of STAT3 dimerization bygarcinol,STAT3 DNA binding ability gets repressed.The inhibition of STAT3 activation by garcinol led to the suppression of various gene products involved in proliferation,survival,and angiogenesis.Finally,when administered i.p.,garcinol inhibited the growth of human HCC xenograft tumors in athymic nu/nu mice.CONCLUSION Results frominvitroand in vivo studies suggest that garcinol exerts its anti-proliferative and pro-apoptotic effects through suppression of STAT3 signaling cascade in HCC by inhibiting its phosphorylation,acetylation and ultimately dimerization.展开更多
The hydrogenation rate of styrene in benzene using RhCI（PPh<sub>3</sub>）<sub>3</sub> as catalyst increases with the concentration of styrene. But the hydrogenation rate of cyclohexene is rath...The hydrogenation rate of styrene in benzene using RhCI（PPh<sub>3</sub>）<sub>3</sub> as catalyst increases with the concentration of styrene. But the hydrogenation rate of cyclohexene is rather different, It shows a maximum. So we inquire into the reaction mechanism of cyclohexene hydrogenation catalyzed by RhCI（PPh<sub>3</sub>）<sub>3</sub>. The rate of hydrogenation was measured at 25±0.15℃, as a function. of catalyst concentration, olefin concentration, triphenylphosphine concentration and hydrogen pressure. The maximum of the reaction rate is interpreted by the formation of RhClL<sub>2</sub>S<sub>2</sub>. The rate determining step is considered to be the reaction of olefin insertion into one of the Rh-H bonds formed by hydrogenation of RhClL3 to H<sub>2</sub>RhClL<sub>3</sub>. The hydrogenation rate of the substrate can be described by a third order equation in terms of concentration of H<sub>2</sub>RhClL<sub>3</sub>. Average error between the results evaluated by this equation and experimental results is about 4.9％. The quantum chemistry calculation gives support to the present mechanism.展开更多
基金Project(20276016) supported by the National Natural Science Foundation of China
文摘The viscoelastic micelle systems formed by novel anionic-nonionic dimeric surfactant and conventional cationic surfactant cetyltrimethylammonium(1631) were studied.The viscoelasticity,thixotropy,flow curves and constitutive equation for the novel viscoelastic micelle systems were investigated.The results show that the micelle systems possess viscoelasticity,thixotropy,and shear thinning property.Some micelle systems possess hysteresis loops showing both viscoelasticity and thixotropy.It is proved that the flow curves are characterized by the co-rotational Jeffreys constitutive equation correctly.
基金Poly U(G-YBGQ G-SB81+3 种基金 G-YZ95)the Research Grant Council of Hong Kong(15101014)ITSP-Guangdong-Hong Kong Technology Cooperation Funding Scheme(GHP/012/16GD)Shenzhen Basic Research Program(JCYJ20160331141459373)
文摘Alzheimer disease(AD) has now become the most common brain disorder among the older population. In addition, the currently existing therapeutics only offer temporary symptomatic relieves. Therefore, further research and development of more efficacious and disease-modifying agents for the prevention, treatment and restoration of AD will have tremendous value from both scientific, and economic standpoints. Over the past few years, our series of studies have identified several highly promising anti-AD dimeric leads, with disease-modifying potentials. In this presentation, the latest progress on the neuroprotective and disease modifying effects and the underlying mechanisms of those candidates will be comprehensively illustrated and discussed.
文摘本文介绍了采用无格点Kinetic Monte Carlo(KMC)方法,模拟TiN薄膜在TiN(001)基底表面上外延生长的仿真结果。在此无格点KMC方法中,使用了Dimer算法在势能面中搜索鞍点和低能盆底。仿真的结果证实,此无格点KMC方法对于仿真二元薄膜外延生长是有效的。本文中还讨论了无格点KMC的计算量问题、运算过程中Dimer的初始位置问题和势能面中浅盆底问题。
文摘Erythropoietin (EPO), a 34 kD glycopro-tein, is the principal growth factor regulating theproduction of circulating erythrocytes; EPO isessential for committed CFU - E erythroid pro-genitors to divide several times and then to dif-ferentiate into erythrocytes. Like most receptorsfor hematopoietic growth factors, the erythro-poietin receptor (EPO - R) is a type I trans-membrane protein and a member of the cytokinereceptor superfamily. These receptors containfour conserved cysteines and a Trp - Ser - X -
文摘The Aux/IAA genes are rapidly and specificallyinduced by the plant hormone auxin and encodeshort-lived nuclear proteins that are capable offorming homo-and hetero-dimer.Molecular,biochemical,and genetic data suggest that theyplay a central role in auxin signaling and plantdevelopment.In order to investigate
基金The project supported in part by agrant from National Medical Research Council of Singapore
文摘OBJECTIVE Hepatocellular carcinoma(HCC)is the fifth most common malignancy worldwide and the third cause of global cancer mortality.Activation of signal transducer and activator of transcription 3(STAT3)is commonly observed in tumor cells and is a critical mediator of on cogenic signaling in HCC and controls the expression of several genes involved in proliferation,survival,metastasis and angiogenesis.Current drug-targeted therapies,besides being expensive,are associated with serious side effects and morbidity.Thus,novel agents that can suppress STAT3 activation have potential for both prevention and treatment of HCC.In the present report,we investigated whether the potent HAT/KAT inhibitor,garcinol,(apolyisoprenylatedbenzophenone),could suppress STAT3 activation in HCC cells and in nude mice model.METHODS The effect of garcinol on HCC cell lines wasdetermined by MTT assay,immunoblotting,DNA binding assays,immuno-fluorescenceand immune-histochemical analysis.The effect of garcinolon the inhibition of tumor growth in vivo was also investigated using HCCxenograft tumor modelin athymic nu/nu mice.RESULTS We found that garcinol could inhibit constitutive STAT3 activation in a dose-and time-dependent manner both by inhibiting STAT3 phosphorylation and acetylation in HCC cells.When investigated for molecular mechanism(s),we found that garcinol interferes with the dimer formation of STAT3 thereby inhibits its nuclear localization.Computational modeling showed that garcinol could bind to the SH2 domain of STAT3 and suppresses its dimerization in vitro.To understand the cellular mechanism(s)of inhibition of STAT3 function by garcinol,we observed that upon inhibition of STAT3 dimerization bygarcinol,STAT3 DNA binding ability gets repressed.The inhibition of STAT3 activation by garcinol led to the suppression of various gene products involved in proliferation,survival,and angiogenesis.Finally,when administered i.p.,garcinol inhibited the growth of human HCC xenograft tumors in athymic nu/nu mice.CONCLUSION Results frominvitroand in vivo studies suggest that garcinol exerts its anti-proliferative and pro-apoptotic effects through suppression of STAT3 signaling cascade in HCC by inhibiting its phosphorylation,acetylation and ultimately dimerization.
文摘The hydrogenation rate of styrene in benzene using RhCI（PPh<sub>3</sub>）<sub>3</sub> as catalyst increases with the concentration of styrene. But the hydrogenation rate of cyclohexene is rather different, It shows a maximum. So we inquire into the reaction mechanism of cyclohexene hydrogenation catalyzed by RhCI（PPh<sub>3</sub>）<sub>3</sub>. The rate of hydrogenation was measured at 25±0.15℃, as a function. of catalyst concentration, olefin concentration, triphenylphosphine concentration and hydrogen pressure. The maximum of the reaction rate is interpreted by the formation of RhClL<sub>2</sub>S<sub>2</sub>. The rate determining step is considered to be the reaction of olefin insertion into one of the Rh-H bonds formed by hydrogenation of RhClL3 to H<sub>2</sub>RhClL<sub>3</sub>. The hydrogenation rate of the substrate can be described by a third order equation in terms of concentration of H<sub>2</sub>RhClL<sub>3</sub>. Average error between the results evaluated by this equation and experimental results is about 4.9％. The quantum chemistry calculation gives support to the present mechanism.
