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@#<b>Objective</b> To ensure the effectiveness and improve the capacity of laboratories in the measurement of γ spectra of radionuclides. <b>Methods</b> A statistical analysis was performed using relative deviation, accuracy, precision, and relative combined uncertainty for the nationwide assessment of radionuclide γ spectrum measurement. <b>Results</b> In the assessment from 2018 to 2020, our laboratory showed qualified or above results, and the performance in 2019 was excellent. The maximum relative deviation of 11 measurements from 2018 to 2020 was 18.01%. The assessment showed |Z<sub>test</sub>|≤1 and U<sub>test</sub>≤2.58 in 2018, |Z<sub>test</sub>|≤1 and U<sub>test</sub>≤1 in 2019, and U<sub>test</sub>≤1 and U<sub>rel</sub>≤20% in 2020. <b>Conclusion</b> Our laboratory employs the correct method for radionuclide γ spectrum measurement, and the analysis data are accurate and reliable.
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Greenhouse gas (GHG) emissions from rivers and lakes have been shown to significantly contribute to global carbon and nitrogen cycling. In spatiotemporal-variable and human-impacted rivers in the grassland region, simultaneous carbon dioxide, methane and nitrous oxide emissions and their relationships under the different land use types are poorly documented. This research estimated greenhouse gas (CO2, CH4, N2O) emissions in the Xilin River of Inner Mongolia of China using direct measurements from 18 field campaigns under seven land use type (such as swamp, sand land, grassland, pond, reservoir, lake, waste water) conducted in 2018. The results showed that CO2 emissions were higher in June and August, mainly affected by pH and DO. Emissions of CH4 and N2O were higher in October, which were influenced by TN and TP. According to global warming potential, CO2 emissions accounted for 63.35% of the three GHG emissions, and CH4 and N2O emissions accounted for 35.98% and 0.66% in the Xilin river, respectively. Under the influence of different degrees of human-impact, the amount of CO2 emissions in the sand land type was very high, however, CH4 emissions and N2O emissions were very high in the artificial pond and the wastewater, respectively. For natural river, the greenhouse gas emissions from the reservoir and sand land were both low. The Xilin river was observed to be a source of carbon dioxide and methane, and the lake was a sink for nitrous oxide.
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Objective To explore the mechanism of down-regulation of regulatory T cells (Treg) by immunization with attenuated activated autologous T cells. Methods Aulologous T cells were activated with ConA in vitro. Mice were immunized subcutaneously and inlraperitoneally every 5 days for 3 times (5 ×10~6 per time for each mouse), and the number and function of Treg were examined. PBS was subcutaneously injected for control group. Serum level of anti-mouse CD25 antibody was measured by ELISA. The number and function of Treg was detected by serum adoptive transfer and proliferation and inhibition assays. Results Compared with control group, there were less CD4~+ CD25~+ Foxp3~+ Treg in the mice after immunization (P < 0. 01), the immunosuppression ability decreased (P<0. 01), and the level of anti-CD25 antibody increased (P <0.01). Adoptive transfer of serum from immunized mice to naive mice led to a significant decrease in Treg population and function in recipient mice (P<0. 01). Conclusion Immunization with attenuated activated autologous T cells induces more anti-CD25 antibody, which may further down-regulate CD4~+CD25~+Foxp3~+ Treg expansion and function in vivo.
