Amercury(Ⅱ)coordinationpolymerwith1,5,9-triselena[9]ferrocenophane(L),[HgI2L·0.5C4H4O·0.5CH3OH]n, has been synthesized and characterized. The X-ray crystal structure shows that bridging by the ligand L caus...Amercury(Ⅱ)coordinationpolymerwith1,5,9-triselena[9]ferrocenophane(L),[HgI2L·0.5C4H4O·0.5CH3OH]n, has been synthesized and characterized. The X-ray crystal structure shows that bridging by the ligand L causes compound to form one-dimensional chain. The half-wave potential of 1,1′-ferrocenylene group is more negative than that of the "free" ligand, which reveals no through-space interaction Hg…Fe in the coordination polymers.展开更多
Metal doping for active sites exhibits remarkable potential for improving the hydrogen evolution reaction(HER).Multi-doping and the use of a conductive substrate can further modulate catalytic performance.Herein,Nb-Co...Metal doping for active sites exhibits remarkable potential for improving the hydrogen evolution reaction(HER).Multi-doping and the use of a conductive substrate can further modulate catalytic performance.Herein,Nb-CoSe well dispersed in N-doped carbon nanospheres(NCs,Nb-CoSe@NC)was synthesized to serve as a conductive substrate and facilitated good dispersion of active sites for the HER.Nb doping can also change the electronic structure of CoSe,which facilitates the activity for the HER.In order to further improve the conductivity and intrinsic activity of Nb-CoSe@NC,dual,nonmetal doping was realized through gas sulfurization to prepare hierarchical Nb-CoSeS@NC.The prepared Nb-CoSeS@NC,with a core-shell structure,exhibited a low overpotential of 115 mV at 10 mA cm–2,which is smaller than that of the most doped catalysts.In addition,NCs not only improved the dispersion and conductivity of the catalyst but also prevented metal corrosion in an electrolyte,thus facilitating the long-term stability of Nb-CoSeS@NC.Moreover,the synergistic effect of the multi-doping of Nb,S,and Se was explained.This work provides a promising,multi-doping strategy for the large-scale application of transition-metal-based electrocatalysts for the HER.展开更多
Selenium（Se） compounds have prevented and Se-deficiency has induced the initiation of cancer. Se（0）-forming compounds and hydroxy-xanthones have killed cancer ceils but shown beneficial effects to normal cells. Th...Selenium（Se） compounds have prevented and Se-deficiency has induced the initiation of cancer. Se（0）-forming compounds and hydroxy-xanthones have killed cancer ceils but shown beneficial effects to normal cells. They may together be effective in the treatment of cancer. Many enzymes which contain selenocysteine （Secys） can catalyze reactions with reducible oxygen （O2~ 02 or H202）. Experiments strongly support that Se-enzymes are activated by Se（0）, from e.g. selenite, selenodiglutathione, binding to Se（-II） in Secys, forming an electron conducting Se-link to reducible oxygen as a protection against oxidations. Cancer cells, which are energy supported only from fermentation, are not dependent on Se which is why they are more sensitive to toxic effects of Se than normal cells. The energy from fermentation is insufficient for normal cell functions. High doses of Se（0）-containing compounds are toxic in that they form links with thiols （R-S-Se） reducing their reaction rate. The reaction of an SH-enzyme, necessary in fermentation, is impaired. Mangostins （hydroxy-xanthones） induce apoptosis in human cancer ceils but stimulate respiration. The OH-groups are responsible for the effects and the reduction of NADP＋ into NADPH. Fermentation is inhibited as NADP＋ is necessary for the process. Cancer may be treated by injections of Se（0）-forming compounds and hydroxy-xanthones into cancer cells in doses causing apoptosis. However, in diluted form, when meting normal cells, the substances promote the yield of energy by stimulating the electron transference to reducible oxygen. Se（0）-activated Se-links and hydrogen from hydroxy-xanthones hopefully prevent the initiation of cancer.展开更多
AIM: To investigate the expression of selenoprotein P mRNA (SePmRNA) in tissues of normal liver, liver cirrhosis and hepatocellular carcinoma (HCC), and its relationship with HCC occurrence and development. METHODS: T...AIM: To investigate the expression of selenoprotein P mRNA (SePmRNA) in tissues of normal liver, liver cirrhosis and hepatocellular carcinoma (HCC), and its relationship with HCC occurrence and development. METHODS: The expression of SePmRNA in tissues of normal liver, liver cirrhosis and HCC were detected by in situ hybridization using a cDNA probe. RESULTS: The enzyme digesting products of PBluescript-H uman Selenoprotein P were evaluated by electrophoresis. The positive expression of SePmRNA was found in the tissues of normal liver, liver cirrhosis and HCC. The expression of SeP mRNA was found in hepatic interstitial substance, especially in endothelial cells and lymphocytes of vasculature. The positive rate of SePmRNA in normal liver tissue was 84.6% (11/13) and the positive signals appeared in the nucleus and cytoplasm, mostly in the nucleolus, and the staining granules were larger in the nucleolus and around the nucleus. The positive rate of SePmRNA in liver cirrhosis tissue was 45.0% (9/20) and the positive signals were mainly in the nucleolus and cytoplasm, being less around the nucleus and inner nucleus than that in normal liver tissue. The positive rate of SePmRNA in HCC tissue was 30.0% (9/30) and the positive signals were in the cytoplasm, but less in the nucleus. CONCLUSION: SePmRNA expression in the tissues of normal liver and HCC is significantly different (84.6% vs 30.0%, P = 0.003), suggesting that SeP might play a role in the occurrence and development of HCC.展开更多
文摘Amercury(Ⅱ)coordinationpolymerwith1,5,9-triselena[9]ferrocenophane(L),[HgI2L·0.5C4H4O·0.5CH3OH]n, has been synthesized and characterized. The X-ray crystal structure shows that bridging by the ligand L causes compound to form one-dimensional chain. The half-wave potential of 1,1′-ferrocenylene group is more negative than that of the "free" ligand, which reveals no through-space interaction Hg…Fe in the coordination polymers.
文摘Metal doping for active sites exhibits remarkable potential for improving the hydrogen evolution reaction(HER).Multi-doping and the use of a conductive substrate can further modulate catalytic performance.Herein,Nb-CoSe well dispersed in N-doped carbon nanospheres(NCs,Nb-CoSe@NC)was synthesized to serve as a conductive substrate and facilitated good dispersion of active sites for the HER.Nb doping can also change the electronic structure of CoSe,which facilitates the activity for the HER.In order to further improve the conductivity and intrinsic activity of Nb-CoSe@NC,dual,nonmetal doping was realized through gas sulfurization to prepare hierarchical Nb-CoSeS@NC.The prepared Nb-CoSeS@NC,with a core-shell structure,exhibited a low overpotential of 115 mV at 10 mA cm–2,which is smaller than that of the most doped catalysts.In addition,NCs not only improved the dispersion and conductivity of the catalyst but also prevented metal corrosion in an electrolyte,thus facilitating the long-term stability of Nb-CoSeS@NC.Moreover,the synergistic effect of the multi-doping of Nb,S,and Se was explained.This work provides a promising,multi-doping strategy for the large-scale application of transition-metal-based electrocatalysts for the HER.
文摘Selenium（Se） compounds have prevented and Se-deficiency has induced the initiation of cancer. Se（0）-forming compounds and hydroxy-xanthones have killed cancer ceils but shown beneficial effects to normal cells. They may together be effective in the treatment of cancer. Many enzymes which contain selenocysteine （Secys） can catalyze reactions with reducible oxygen （O2~ 02 or H202）. Experiments strongly support that Se-enzymes are activated by Se（0）, from e.g. selenite, selenodiglutathione, binding to Se（-II） in Secys, forming an electron conducting Se-link to reducible oxygen as a protection against oxidations. Cancer cells, which are energy supported only from fermentation, are not dependent on Se which is why they are more sensitive to toxic effects of Se than normal cells. The energy from fermentation is insufficient for normal cell functions. High doses of Se（0）-containing compounds are toxic in that they form links with thiols （R-S-Se） reducing their reaction rate. The reaction of an SH-enzyme, necessary in fermentation, is impaired. Mangostins （hydroxy-xanthones） induce apoptosis in human cancer ceils but stimulate respiration. The OH-groups are responsible for the effects and the reduction of NADP＋ into NADPH. Fermentation is inhibited as NADP＋ is necessary for the process. Cancer may be treated by injections of Se（0）-forming compounds and hydroxy-xanthones into cancer cells in doses causing apoptosis. However, in diluted form, when meting normal cells, the substances promote the yield of energy by stimulating the electron transference to reducible oxygen. Se（0）-activated Se-links and hydrogen from hydroxy-xanthones hopefully prevent the initiation of cancer.
基金Supported by Science and Technology Investigation and Development Project of Shaanxi Province, No. 2002K10-G1
文摘AIM: To investigate the expression of selenoprotein P mRNA (SePmRNA) in tissues of normal liver, liver cirrhosis and hepatocellular carcinoma (HCC), and its relationship with HCC occurrence and development. METHODS: The expression of SePmRNA in tissues of normal liver, liver cirrhosis and HCC were detected by in situ hybridization using a cDNA probe. RESULTS: The enzyme digesting products of PBluescript-H uman Selenoprotein P were evaluated by electrophoresis. The positive expression of SePmRNA was found in the tissues of normal liver, liver cirrhosis and HCC. The expression of SeP mRNA was found in hepatic interstitial substance, especially in endothelial cells and lymphocytes of vasculature. The positive rate of SePmRNA in normal liver tissue was 84.6% (11/13) and the positive signals appeared in the nucleus and cytoplasm, mostly in the nucleolus, and the staining granules were larger in the nucleolus and around the nucleus. The positive rate of SePmRNA in liver cirrhosis tissue was 45.0% (9/20) and the positive signals were mainly in the nucleolus and cytoplasm, being less around the nucleus and inner nucleus than that in normal liver tissue. The positive rate of SePmRNA in HCC tissue was 30.0% (9/30) and the positive signals were in the cytoplasm, but less in the nucleus. CONCLUSION: SePmRNA expression in the tissues of normal liver and HCC is significantly different (84.6% vs 30.0%, P = 0.003), suggesting that SeP might play a role in the occurrence and development of HCC.
