This paper describes a low-cost and fast method to evaluate gross α and β^(-) radioactivities in natural water based on an online high-purity germanium detector gamma measurement system.The major gamma activities in...This paper describes a low-cost and fast method to evaluate gross α and β^(-) radioactivities in natural water based on an online high-purity germanium detector gamma measurement system.The major gamma activities in natural water are provided by natural and artificial radionuclides such as ^(40) K,^(137)Cs,and radionuclides belonging to ^(238)U and ^(232)Th series.The main a emitters related to gamma emissions in natural water are ^(224)Ra(240.98 keV)and ^(226)Ra(186.21 keV),and the β^(-) emitters are ^(40) K(1460.85 keV),^(214)Bi(609.31 keV),^(208)Tl(583.19 keV),and ^(214)Pb(351.93 keV).The formula for gross α and β^(-) activity concentration is based on these radionuclides,and the short half-life decay products are considered in the calculation.The detection efficiency of the device across energy region(0–3 MeV)is obtained through Monte Carlo simulation,and a calibration experiment is conducted to verify the simulation results.Gamma radioactivity is measured continuously for 114 d in Pixian County and Dongfeng Canal located in the Zouma River,Chengdu,Sichuan Province,China.A comparison of the calculation results and monitoring data from the Sichuan Management and Monitoring Center Station of Radioactive Environment indicates that the percentage and absolute error of a activity concentration is lower than 53%and 0.02 Bq/L,respectively,and that of β-activity concentration is lower than 33.2%and 0.016 Bq/L,respectively.The method can rapidly determine gross α and β^(-) activity concentrations in natural water online.展开更多
BACKGROUND:Small-for-size(SFS)syndrome is an important clinical problem after living donor liver transplantation,split liver transplantation or extended hepatectomy.The uncertainty of the mechanisms and treatments of ...BACKGROUND:Small-for-size(SFS)syndrome is an important clinical problem after living donor liver transplantation,split liver transplantation or extended hepatectomy.The uncertainty of the mechanisms and treatments of SFS syndrome urges surgeons to establish effective models for SFS syndrome.METHODS:A new porcine model for SFS syndrome based on extended hepatectomy was established.Portal pressure gradient was observed before and after the surgery,and venous sampling for estimation of alanine aminotransferase,total bilirubin,and international normalized ratio was continued on a daily basis.RESULTS:Although the external morphology of the porcine liver differs from that of human being,segmental anatomy is remarkably similar in term of its vascularity and biliary tree.Extended hepatectomy with segmentsⅠandⅦas resection remnant(about 20%of total liver volume)resulted in similar survival rates,blood liver function tests,and elevated portal pressure gradient as clinical SFS syndrome.CONCLUSIONS:The extended hepatectomy based new model can easily be reproduced,with few costs and surgical complications.Clinical SFS syndrome can easily be simulated by this new model,which is a useful tool for studying SFS syndrome-related liver injuries,especially portal overperfusion and hypertension.展开更多
基金the National Science Foundation of China(No.41774147)the National Key R&D Program of China(No.2017YFC0602105)+1 种基金the Science–Technology Support Plan Projects of Sichuan Province(No.2020YJ0334)the Sichuan Science and Technology Program(No.2020JDRC0108).
文摘This paper describes a low-cost and fast method to evaluate gross α and β^(-) radioactivities in natural water based on an online high-purity germanium detector gamma measurement system.The major gamma activities in natural water are provided by natural and artificial radionuclides such as ^(40) K,^(137)Cs,and radionuclides belonging to ^(238)U and ^(232)Th series.The main a emitters related to gamma emissions in natural water are ^(224)Ra(240.98 keV)and ^(226)Ra(186.21 keV),and the β^(-) emitters are ^(40) K(1460.85 keV),^(214)Bi(609.31 keV),^(208)Tl(583.19 keV),and ^(214)Pb(351.93 keV).The formula for gross α and β^(-) activity concentration is based on these radionuclides,and the short half-life decay products are considered in the calculation.The detection efficiency of the device across energy region(0–3 MeV)is obtained through Monte Carlo simulation,and a calibration experiment is conducted to verify the simulation results.Gamma radioactivity is measured continuously for 114 d in Pixian County and Dongfeng Canal located in the Zouma River,Chengdu,Sichuan Province,China.A comparison of the calculation results and monitoring data from the Sichuan Management and Monitoring Center Station of Radioactive Environment indicates that the percentage and absolute error of a activity concentration is lower than 53%and 0.02 Bq/L,respectively,and that of β-activity concentration is lower than 33.2%and 0.016 Bq/L,respectively.The method can rapidly determine gross α and β^(-) activity concentrations in natural water online.
基金supported by a grant from Science and Technology Commission of Shanghai Municipality(07JC14040)
文摘BACKGROUND:Small-for-size(SFS)syndrome is an important clinical problem after living donor liver transplantation,split liver transplantation or extended hepatectomy.The uncertainty of the mechanisms and treatments of SFS syndrome urges surgeons to establish effective models for SFS syndrome.METHODS:A new porcine model for SFS syndrome based on extended hepatectomy was established.Portal pressure gradient was observed before and after the surgery,and venous sampling for estimation of alanine aminotransferase,total bilirubin,and international normalized ratio was continued on a daily basis.RESULTS:Although the external morphology of the porcine liver differs from that of human being,segmental anatomy is remarkably similar in term of its vascularity and biliary tree.Extended hepatectomy with segmentsⅠandⅦas resection remnant(about 20%of total liver volume)resulted in similar survival rates,blood liver function tests,and elevated portal pressure gradient as clinical SFS syndrome.CONCLUSIONS:The extended hepatectomy based new model can easily be reproduced,with few costs and surgical complications.Clinical SFS syndrome can easily be simulated by this new model,which is a useful tool for studying SFS syndrome-related liver injuries,especially portal overperfusion and hypertension.
