In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate ...In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate the time constant of a semiconductor survey meter and confirm the meter’s function. An additional filter was attached to the medical X-ray system to satisfy the standards of N-60 to N-120, more copper plates were added as needed, and the first and second half-value layers were calculated to enable comparisons of the facility’s X-ray system quality with the N-60 to N-120 quality values. Next, we used a medical X-ray system to measure the leakage dose and calculate the time constant of the survey meter. The functionality of the meter was then checked and compared with the energy characteristics of the meter. The experimental results showed that it was possible to use a medical X-ray system to reproduce the N-60 to N-120 radiation quality values and to calculate the time constant from the measured results, assuming actual leakage dosimetry for that radiation quality. We also found that the calibration factor was equivalent to that of the energy characteristics of the survey meter.展开更多
目的基于血液筛查核酸检测反应性献血者的HBV感染的确认,探讨核酸检测反应性献血者的归队策略。方法联合应用自建的高灵敏度核酸检测体系、血液核酸筛查等多种核酸检测(NAT)方法,并结合血清学检测、献血者随访,对核酸检测反应性(NAT-yie...目的基于血液筛查核酸检测反应性献血者的HBV感染的确认,探讨核酸检测反应性献血者的归队策略。方法联合应用自建的高灵敏度核酸检测体系、血液核酸筛查等多种核酸检测(NAT)方法,并结合血清学检测、献血者随访,对核酸检测反应性(NAT-yield)献血者中的HBV感染进行确认和感染状态识别。依据确认的HBV感染血浆样本,比较不同确认方法、确认指标或指标组合对HBV感染确认的效果。结果2010年11月—2021年2月,在血液筛查检出的876位NAT-yield献血者中共确认HBV感染者511人(OBI 451人,急性早期HBV感染者27人,不能确认感染者33人,无感染者30人,不能确认HBV感染者335人)。采用单检系统对混检系统检出的HBV感染血浆进行复测的检出率为96.6%,明显高于混检系统对单检系统检出的HBV DNA反应性(HBV DNA R)组和鉴别试验无反应性(NDR)组的复测检出率(76.4%和55.7%)(P<0.05)。NDR样本在模式2(ID×5+鉴别×2)下复测检出率(65.2%)高于模式1(ID×2+鉴别×1)(39.2%)(P<0.05);2种单检复测模式下的HBV DNA R样本复测检出率无明显差异(P>0.05),但均明显高于NDR样本(P<0.05)。回溯OBI献血者既往NAT数据,有46%经历多次NAT检测而未能检出。有59.1%OBI献血者随访检不出HBV DNA。OBI献血者中抗-HBc+占比为90.2%,单独抗-HBc+为49.2%,远高于不能确认感染组(P<0.05);HBeAg、抗-HBe和抗-HBc IgM在OBI和不能确认感染组中的比例极低且无差异(P>0.05)。结论近60%的NAT-yield献血者可以确认HBV感染。为保证献血者归队的安全性,需要更高灵敏度的HBV DNA确证技术提高HBV感染的确认率。抗-HBc是NAT-yield献血者OBI风险排查和归队评估最重要的血清学指标。展开更多
文摘In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate the time constant of a semiconductor survey meter and confirm the meter’s function. An additional filter was attached to the medical X-ray system to satisfy the standards of N-60 to N-120, more copper plates were added as needed, and the first and second half-value layers were calculated to enable comparisons of the facility’s X-ray system quality with the N-60 to N-120 quality values. Next, we used a medical X-ray system to measure the leakage dose and calculate the time constant of the survey meter. The functionality of the meter was then checked and compared with the energy characteristics of the meter. The experimental results showed that it was possible to use a medical X-ray system to reproduce the N-60 to N-120 radiation quality values and to calculate the time constant from the measured results, assuming actual leakage dosimetry for that radiation quality. We also found that the calibration factor was equivalent to that of the energy characteristics of the survey meter.
文摘目的基于血液筛查核酸检测反应性献血者的HBV感染的确认,探讨核酸检测反应性献血者的归队策略。方法联合应用自建的高灵敏度核酸检测体系、血液核酸筛查等多种核酸检测(NAT)方法,并结合血清学检测、献血者随访,对核酸检测反应性(NAT-yield)献血者中的HBV感染进行确认和感染状态识别。依据确认的HBV感染血浆样本,比较不同确认方法、确认指标或指标组合对HBV感染确认的效果。结果2010年11月—2021年2月,在血液筛查检出的876位NAT-yield献血者中共确认HBV感染者511人(OBI 451人,急性早期HBV感染者27人,不能确认感染者33人,无感染者30人,不能确认HBV感染者335人)。采用单检系统对混检系统检出的HBV感染血浆进行复测的检出率为96.6%,明显高于混检系统对单检系统检出的HBV DNA反应性(HBV DNA R)组和鉴别试验无反应性(NDR)组的复测检出率(76.4%和55.7%)(P<0.05)。NDR样本在模式2(ID×5+鉴别×2)下复测检出率(65.2%)高于模式1(ID×2+鉴别×1)(39.2%)(P<0.05);2种单检复测模式下的HBV DNA R样本复测检出率无明显差异(P>0.05),但均明显高于NDR样本(P<0.05)。回溯OBI献血者既往NAT数据,有46%经历多次NAT检测而未能检出。有59.1%OBI献血者随访检不出HBV DNA。OBI献血者中抗-HBc+占比为90.2%,单独抗-HBc+为49.2%,远高于不能确认感染组(P<0.05);HBeAg、抗-HBe和抗-HBc IgM在OBI和不能确认感染组中的比例极低且无差异(P>0.05)。结论近60%的NAT-yield献血者可以确认HBV感染。为保证献血者归队的安全性,需要更高灵敏度的HBV DNA确证技术提高HBV感染的确认率。抗-HBc是NAT-yield献血者OBI风险排查和归队评估最重要的血清学指标。