An accurate energy calibration of a BC501A liquid scintillator by means of Compton scattering of γ-rays is described.The energy resolution and the position of the Compton edge have been precisely determined using a ...An accurate energy calibration of a BC501A liquid scintillator by means of Compton scattering of γ-rays is described.The energy resolution and the position of the Compton edge have been precisely determined using a γ-γ coincidence technique and fitting the coincidence spectrum with a Gaussian function superimposed on a quadratic polynomial for the background.The position of the Compton edge relative to the position of the maximum and the half height of the distribution in dependence on the relevant energy resolution is discussed in detail.The results indicate that the maximum energy of the recoil Compton electron does not occur at the half height distribution but at 0.90±0.05 of the maximum height in the energy range considered.The energy resolution varies from 15.6% to 8.02% for electrons in the energy region from 0.5 MeV to 3 MeV.展开更多
目的初步探讨新型生物佐剂BC01(BCG CpG DNA compound adjuvant system 01)对机体的免疫激活作用。方法将C57BL/6小鼠随机分为4组并分别肌肉注射75μg新型生物佐剂BC01,实验组于免疫后6、12和24 h解剖取脾脏,对照组于注射BC01后0 h解剖...目的初步探讨新型生物佐剂BC01(BCG CpG DNA compound adjuvant system 01)对机体的免疫激活作用。方法将C57BL/6小鼠随机分为4组并分别肌肉注射75μg新型生物佐剂BC01,实验组于免疫后6、12和24 h解剖取脾脏,对照组于注射BC01后0 h解剖取脾脏。提取各组小鼠总RNA并进行全基因转录组分析。基因芯片数据经归一化处理后进行基因集富集分析(gene set enrichment analysis,GSEA)。同时,采用实时定量PCR法对GSEA中GO(gene ontology,GO)基因集分组归类中生物过程(biological process,BP)、细胞成分(cellular component,CC)和分子功能(molecular function,MF)相关上调基因进行验证分析。结果小鼠全基因转录组芯片数据经GSEA分析后发现,BC01佐剂具有活化免疫细胞,激活固有免疫和适应性免疫应答,调节炎症反应、活化免疫细胞迁移与趋化,激活免疫细胞吞噬功能以及促分裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)和细胞外调节蛋白激酶1/2(extracellular-regulated kinase 1/2,ERK1/2)信号级联反应作用。结论新型生物佐剂BC01经肌肉注射24 h后具有较强的机体免疫激活作用。展开更多
文摘An accurate energy calibration of a BC501A liquid scintillator by means of Compton scattering of γ-rays is described.The energy resolution and the position of the Compton edge have been precisely determined using a γ-γ coincidence technique and fitting the coincidence spectrum with a Gaussian function superimposed on a quadratic polynomial for the background.The position of the Compton edge relative to the position of the maximum and the half height of the distribution in dependence on the relevant energy resolution is discussed in detail.The results indicate that the maximum energy of the recoil Compton electron does not occur at the half height distribution but at 0.90±0.05 of the maximum height in the energy range considered.The energy resolution varies from 15.6% to 8.02% for electrons in the energy region from 0.5 MeV to 3 MeV.
