Exploration of ²⁴¹Am measurement in fecal samples / 中国辐射卫生

@#<b>Objective</b> To preliminarily study and establish a method for measurement of the transuranic nuclide ²⁴¹Am in fecal samples, and to provide technical support for internal radiation monitoring of staff. <b>Methods</b> Fecal samples were collected with a self-made stool sampler and treated with a self-made carbonization and ashing furnace. DGA resin was used to separate and purify ²⁴¹Am from fecal samples. With ²⁴³Am as the tracer, the orthogonal method was used for condition optimization. <b>Results</b> The optimum conditions for separation and purification were: the acidity of HNO₃ added into the column, 6 mol/L; column flow rate, 0.6 mL/min; and the volume of analytical solution,12 mL. The method based on inductively coupled plasma mass spectrometry showed a detection limit of 9.79×10⁻⁴ Bq for ²⁴¹Am in fecal samples, which was satisfactory and feasible. <b>Conclusion</b> This method fills the vacancy of ²⁴¹Am measurement in fecal samples to some extent, which is of practical significance for internal radiation monitoring and protection for analysts.

A New High-throughput Real-time PCR Assay for the Screening of Multiple Antimicrobial Resistance Genes in Broiler Fecal Samples from China / 生物医学与环境科学（英文）

OBJECTIVE@#Antimicrobial resistance (AMR) has become a global concern and is especially severe in China. To effectively and reliably provide AMR data, we developed a new high-throughput real-time PCR assay based on microfluidic dynamic technology, and screened multiple AMR genes in broiler fecal samples.@*METHODS@#A high-throughput real-time PCR system with an new designed integrated fluidic circuit assay were performed AMR gene detection. A total of 273 broiler fecal samples collected from two geographically separated farms were screened AMR genes.@*RESULTS@#The new assay with limits of detection ranging from 40.9 to 8,000 copies/reaction. The sensitivity rate, specificity rate, positive predictive value, negative predictive value and correct indices were 99.30%, 98.08%, 95.31%, 99.79%, and 0.9755, respectively. Utilizing this assay, we demonstrate that AMR genes are widely spread, with positive detection rates ranging from 0 to 97.07% in 273 broiler fecal samples. blaCTX-M, blaTEM, mcr-1, fexA, cfr, optrA, and intI1 showed over 80% prevalence. The dissemination of AMR genes was distinct between the two farms.@*CONCLUSION@#We successfully established a new high-throughput real-time PCR assay applicable to AMR gene surveillance from fecal samples. The widespread existence of AMR genes detected in broiler farms highlights the current and severe problem of AMR.