Toxic Effects of Four Currently-used Pesticides on Zebrafish Embryonic Development

为了研究4种农药(腈苯唑、吡唑醚菌酯、恶霜灵、戊菌隆)单独及联合作用对斑马鱼胚胎发育的影响,设计7个实验组(空白组、溶剂组、4种农药单独暴露组及; 联合暴露组)对斑马鱼胚胎暴露72 h,结果显示,浓度50; ng/L的4种农药单独暴露导致心包囊和卵黄囊水肿比率、脊柱弯曲率均显著高于对照组;腈苯唑、恶霜灵及联合暴露导致斑马鱼仔鱼心率显著下降,出现显著的; 心律不齐;斑马鱼胚胎的Na~+/K~+-ATP酶和Ca~(2+)-ATP酶活性被显著诱导,而联合暴露表现出显著的抑制作用。结果说明,环境浓度的农; 药暴露对鱼类胚胎发育具有明显的毒性。In order to study the effects of four; pesticides(fenbuconazole,pyraclostrobin,metoxazon,and; pencycurone),either individually or jointly,on the development of; zebrafish embryos,seven experiments(blank control,solvent; control,individual of 4 pesticides,and jointly combined four; pesticides)were designed to treat zebrafish embryos for 72 h. The; results showed that individual exposure to any of 4 pesticides at 50; ng/L led to the significant elevation on the rate of pericardial and; yolk sac edema and the frequency of dorsal curvature in the larvae; compared to the control. The exposure to fenbuconazole,metoxazon,and; combined four pesticides resulted in a significant reduction in the; heart rate and a significant increase in cardiac arrhythmia in the; zebrafish larvae. The activities of Na~+/K~+-ATPase and Ca~(2+)-ATPase; of the embryos were significantly induced by the individual exposure to; 4 pesticides,while the both activities were remarkably inhibited by the; combined exposure. The results confirmed that these pesticides at; environmental relevant concentration presented the clear toxicity to the; development of fish embryo.国家自然科学基金项目; 福建省2011协同创新中

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