Studies on inhibition of Na_6PMo_(11)FeO_(40)to melanin formation in mouse melanoma B16Cell and its antibacterial activity

研究了过渡金属取代的Kiggen型结构的杂多酸盐Na_6PMo_(11)FeO_(40)对体外培养的小鼠黑色素瘤B16细胞的生物学效应,并分析了; 其对4种细菌的抗菌活性.结果显示:不同浓度的Na_6PMo_(11)FeO_(40)对B16细胞的细胞形态和数量有不同程度的影响,对B16细胞的; 增殖率、酪氨酸酶活性以及黑色素合成量的抑制呈现出明显的浓度效应.浓度为50~200mumol/L的Na_6PMo_(11)FeO_(40)能显著; 抑制B16细胞增殖(P<0.05或P<0.01);浓度为200mumol/L的Na_6PMo_(11)FeO_(40)对酪氨酸酶活性抑制极显著(; P <0.01),IC_(50)为166.5 mumol/L;; Na_6PMo_(11)FeO_(40)对藤黄八叠球菌、金黄色葡萄球菌、枯草芽孢杆菌和大肠杆菌均有抗菌作用,且对球菌的抑制效果优于杆菌.实验结果; 表明,Na_6PMo_(11)FeO_(40)可作为具有防腐抑菌功能的新型酪氨酸酶抑制剂.The bio-efficacy of Keggen-type Fe-substituted heteropoly; salt(Na_6PMo_(11)FeO_(40))on mouse B16melanoma cell in vitro was; researched,and its antibacterial activity of four species of bacteria; was analyzed in this paper.The results showed that the cell morphology; and number of B16cell were changed by different concentrations of; Na_6PMo_(11)FeO_(40).And the inhibition effect of Na_6PMo_(11)FeO_(40)on; cell proliferation rate,tyrosinase activity and melanin content appears; dose-effect relationship.The proliferation of B16cell was inhibited; significantly after treat with 50~200mol/L of Na_6PMo_(11)FeO_(40); (P<0.05or P<0.01).The inhibition effect of Na_6PMo_(11)FeO_(40)on; tyrosinase activity is significant (P<0.01),its IC_(50)is; 166.5mol/L.Na_6PMo_(11)FeO_(40)have an antibacterial effect on the four; tested bacteria(Escherichia coli,Bacillus subtilis,Staphylococcus aureus; and Sarcina lutea),and its inhibitory effect on the coccus is better; than bacillus.The result indicated that Na_6PMo_(11)FeO_(40)can be used; as a new tyrosinase inhibitor with antibacterial activity.国家自然科学基金资助项

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies