Atmospheric radionuclide monitoring usually includes two sampling techniques, namely ultra-high volume aerosol samplers to collect at- mospheric particles by using filter media, and radioactive noble gas samplers to c...Atmospheric radionuclide monitoring usually includes two sampling techniques, namely ultra-high volume aerosol samplers to collect at- mospheric particles by using filter media, and radioactive noble gas samplers to collect atmospheric noble gas based on adsorption method. Atmos- pheric sampling techniques have been researched in Northwest Institute of Nuclear Technology since the Comprehensive Nuclear-Test-Ban Treaty （CTBT） was signed in 1996. Several ultra-high volume aerosol samplers and some types of radioactive xenon isotopes samplers had been devel- oped. For the aerosol sampler, the sampling flow is between 450 and 800 m3/h, with the minimum detectable concentration （MDC） of 131I less than 5 pBq/m3. For the xenon sampler, the sampling capacity of xenon is more than 4 ml per day, with MDC of l=Xe less than 0.25 mBq/m3. After the nuclear accident of Fukushima in 2011, monitoring of the atmospheric radionuclide was carried out for 3 months at Xi＇an, and part of radionuclide was detected with concentrations hiaher than their backorounds in the period, includina 131I.134Cs. 137Cs and 133Xe.展开更多
Aerosol radionuclides (131I, 134Cs, 137Cs) and gaseous radioactive xenon (133Xe) were monitored at Xi'an, China following the accident at the Fukushima nuclear power plant in March 2011. The additional annual effe...Aerosol radionuclides (131I, 134Cs, 137Cs) and gaseous radioactive xenon (133Xe) were monitored at Xi'an, China following the accident at the Fukushima nuclear power plant in March 2011. The additional annual effective dose attributable to the Fukushima emissions was much lower than the public annual effective dose from natural radiation, according to Chinese national standards. The monitoring results were compared with data from other countries as well as with the radionuclide concentrations observed in Xi'an after the Chernobyl nuclear accident in 1986. Possible transport pathways of the released radionuclides from Fukushima to Xi'an were investigated. The occurrence of an anticyclone in the Pacific Ocean region and the extended period over which the radionuclides were released made the determination transport pathways complex, but divergence in the plume and easterly flow evidently brought the initial suite of radionuclides to Xi'an.展开更多
Flavonols, the main flavonoids in plant leaves, have newly been proposed as a H2O2 scavenger in guard cells. However, whether 5-aminolevulinic acid(5-ALA) is involved in regulating stomatal movement of apple(Malus ...Flavonols, the main flavonoids in plant leaves, have newly been proposed as a H2O2 scavenger in guard cells. However, whether 5-aminolevulinic acid(5-ALA) is involved in regulating stomatal movement of apple(Malus × domestica Borkh. ‘Fuji') leaves through flavonol accumulation remains unclear. In this study, using diphenylboric acid 2-amino ethyl ester(DPBA, a flavonol fluorescent dye) and a laser scanning confocal microscope,we observed that 5-ALA pretreatment significantly improved flavonol accumulation in guard cells of apple leaves, especially around the nucleus.Then we demonstrated that 5-ALA pretreatment inhibited ABA-induced stomatal closure via decreasing reaction oxygen species(ROS) accumulation in guard cells. Pretreatment with quercetin or kaempferol, two main kinds of flavonols in plants, also inhibited ABA-induced stomatal closure by decreasing ROS content in the guard cells. Furthermore, exogenous flavonols could suppress H2O2-induced stomatal closure in apple leaves.Taken together, we conclude that ALA-induced flavonol accumulation in guard cells is involved in the inhibitory effect of ALA on ABA-induced ROS accumulation and stomatal closure in apple leaves.展开更多
文摘Atmospheric radionuclide monitoring usually includes two sampling techniques, namely ultra-high volume aerosol samplers to collect at- mospheric particles by using filter media, and radioactive noble gas samplers to collect atmospheric noble gas based on adsorption method. Atmos- pheric sampling techniques have been researched in Northwest Institute of Nuclear Technology since the Comprehensive Nuclear-Test-Ban Treaty （CTBT） was signed in 1996. Several ultra-high volume aerosol samplers and some types of radioactive xenon isotopes samplers had been devel- oped. For the aerosol sampler, the sampling flow is between 450 and 800 m3/h, with the minimum detectable concentration （MDC） of 131I less than 5 pBq/m3. For the xenon sampler, the sampling capacity of xenon is more than 4 ml per day, with MDC of l=Xe less than 0.25 mBq/m3. After the nuclear accident of Fukushima in 2011, monitoring of the atmospheric radionuclide was carried out for 3 months at Xi＇an, and part of radionuclide was detected with concentrations hiaher than their backorounds in the period, includina 131I.134Cs. 137Cs and 133Xe.
文摘Aerosol radionuclides (131I, 134Cs, 137Cs) and gaseous radioactive xenon (133Xe) were monitored at Xi'an, China following the accident at the Fukushima nuclear power plant in March 2011. The additional annual effective dose attributable to the Fukushima emissions was much lower than the public annual effective dose from natural radiation, according to Chinese national standards. The monitoring results were compared with data from other countries as well as with the radionuclide concentrations observed in Xi'an after the Chernobyl nuclear accident in 1986. Possible transport pathways of the released radionuclides from Fukushima to Xi'an were investigated. The occurrence of an anticyclone in the Pacific Ocean region and the extended period over which the radionuclides were released made the determination transport pathways complex, but divergence in the plume and easterly flow evidently brought the initial suite of radionuclides to Xi'an.
基金supported by the National Natural Science Foundation of China (31401820)the Natural Science Foundation of Jiangsu Province, China (BK20140702)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD130809001)the Fundamental Research Funds for the Central Universities (KJQN201538)
文摘Flavonols, the main flavonoids in plant leaves, have newly been proposed as a H2O2 scavenger in guard cells. However, whether 5-aminolevulinic acid(5-ALA) is involved in regulating stomatal movement of apple(Malus × domestica Borkh. ‘Fuji') leaves through flavonol accumulation remains unclear. In this study, using diphenylboric acid 2-amino ethyl ester(DPBA, a flavonol fluorescent dye) and a laser scanning confocal microscope,we observed that 5-ALA pretreatment significantly improved flavonol accumulation in guard cells of apple leaves, especially around the nucleus.Then we demonstrated that 5-ALA pretreatment inhibited ABA-induced stomatal closure via decreasing reaction oxygen species(ROS) accumulation in guard cells. Pretreatment with quercetin or kaempferol, two main kinds of flavonols in plants, also inhibited ABA-induced stomatal closure by decreasing ROS content in the guard cells. Furthermore, exogenous flavonols could suppress H2O2-induced stomatal closure in apple leaves.Taken together, we conclude that ALA-induced flavonol accumulation in guard cells is involved in the inhibitory effect of ALA on ABA-induced ROS accumulation and stomatal closure in apple leaves.
