1.Application and optimization of HDEHP extraction chromatography in the determination of strontium-90 in seafood
Cen SHI ; Yuhan XIE ; Yuxin QIAN ; Yanqin JI
Chinese Journal of Radiological Health 2025;34(2):231-236
Objective To evaluate the environmental radioactive safety level in China, monitor the radioactivity of strontium-90 (90Sr) in seafood from selected marine regions of China, and optimize the di-(2-ethylhexyl)phosphoric acid (HDEHP) extraction chromatography method for determining Sr-90 in seafood. Methods In 2023, seafoods of fish, shrimp, shellfish, and seaweed were collected from the Shandong Province (Bohai Sea and Yellow Sea) and Hainan Province (South China Sea). The levels of Sr in the samples were determined by inductively coupled plasma atomic emission spectrometer (ICP-AES). The 90Sr separation were performed using HDEHP extraction chromatography, while the recovery of 90Sr were determined by the gravitmetry with the assistant of ICP-AES. Results The content of strontium in seafoods varies greatly, and excessive strontium and calcium in seafood may lead to overestimated recovery due to insufficient leaching during chromatographic separation by HDEHP extraction. Therefore, the yttrium content in the eluent should be analyzed by ICP . The radioactivity of 90Sr in seafood from the sea areas in Shandong Province was 0.22-1.85 Bq/kg (dry weight), and that of seafood from Hainan Province was 0.19-1.82 Bq/kg (dry weight). Conclusion For the analysis of shirmp and seaweed samples, the recovery rate of 90Sr should be analyzed using both gravimetry and ICP-AES. There is no significant linear correlation between total Sr and 90Sr in seafood. There is no significant difference in 90Sr radioactivity between the seafood samples collected from Shandong and Hainan. The 90Sr radioactivity levels of all 28 samples are below the limit specified in the Limited concentrations of radioactive materials in foods (GB 14882—1994) and are within the range of environmental background fluctuations.
2.Analysis of the 2023 national interlaboratory comparison for measurement of gross α and gross β radioactivity in water
Liangliang YIN ; Yuhan XIE ; Yuxin QIAN ; Cen SHI ; Yanqin JI
Chinese Journal of Radiological Health 2025;34(2):237-241
Objective To organize a nationwide interlaboratory comparison for measurement of gross α and gross β radioactivity in water, and improve the laboratory analysis of gross α and gross β radioactivity in water. Methods A unified comparison protocol was developed by the organizers. The groundwater with high natural radioactivity was used as water sample and distributed randomly to the participating laboratories. The participating laboratories used routine analytical methods to measure the samples and provided information such as analytical results, original records, and test reports. The results were evaluated using z-score. Results A total of 76 laboratories participated in the comparison, all employing the evaporation concentration-α/β counting method. Among them, 69 laboratories achieved |z| ≤ 2 for both gross α and gross β radioactivity measurements, and 32 laboratories achieved |z| ≤ 0.50 for both gross α and gross β radioactivity measurements. There were 69 laboratories with qualified results and 30 laboratories with excellent results, yielding a qualified rate of 90.8% and an excellent rate of 39.5%. Seven laboratories showed unqualified results and the unqualified rate was 9.2%. Conclusion Most laboratories have the ability to analyze gross α and gross β radioactivity in water. The main reasons for the deviation in comparison results are calibration efficiency, errors in the total residue mass caused by improper water sample processing operations. By analyzing the main technical problems existed in unqualified laboratories, their ability for measurement of gross α and gross β radioactivity in water has been improved.
3.Surveillance of bacterial resistance in tertiary hospitals across China:results of CHINET Antimicrobial Resistance Surveillance Program in 2022
Yan GUO ; Fupin HU ; Demei ZHU ; Fu WANG ; Xiaofei JIANG ; Yingchun XU ; Xiaojiang ZHANG ; Fengbo ZHANG ; Ping JI ; Yi XIE ; Yuling XIAO ; Chuanqing WANG ; Pan FU ; Yuanhong XU ; Ying HUANG ; Ziyong SUN ; Zhongju CHEN ; Jingyong SUN ; Qing CHEN ; Yunzhuo CHU ; Sufei TIAN ; Zhidong HU ; Jin LI ; Yunsong YU ; Jie LIN ; Bin SHAN ; Yunmin XU ; Sufang GUO ; Yanyan WANG ; Lianhua WEI ; Keke LI ; Hong ZHANG ; Fen PAN ; Yunjian HU ; Xiaoman AI ; Chao ZHUO ; Danhong SU ; Dawen GUO ; Jinying ZHAO ; Hua YU ; Xiangning HUANG ; Wen'en LIU ; Yanming LI ; Yan JIN ; Chunhong SHAO ; Xuesong XU ; Wei LI ; Shanmei WANG ; Yafei CHU ; Lixia ZHANG ; Juan MA ; Shuping ZHOU ; Yan ZHOU ; Lei ZHU ; Jinhua MENG ; Fang DONG ; Zhiyong LÜ ; Fangfang HU ; Han SHEN ; Wanqing ZHOU ; Wei JIA ; Gang LI ; Jinsong WU ; Yuemei LU ; Jihong LI ; Qian SUN ; Jinju DUAN ; Jianbang KANG ; Xiaobo MA ; Yanqing ZHENG ; Ruyi GUO ; Yan ZHU ; Yunsheng CHEN ; Qing MENG ; Shifu WANG ; Xuefei HU ; Wenhui HUANG ; Juan LI ; Quangui SHI ; Juan YANG ; Abulimiti REZIWAGULI ; Lili HUANG ; Xuejun SHAO ; Xiaoyan REN ; Dong LI ; Qun ZHANG ; Xue CHEN ; Rihai LI ; Jieli XU ; Kaijie GAO ; Lu XU ; Lin LIN ; Zhuo ZHANG ; Jianlong LIU ; Min FU ; Yinghui GUO ; Wenchao ZHANG ; Zengguo WANG ; Kai JIA ; Yun XIA ; Shan SUN ; Huimin YANG ; Yan MIAO ; Mingming ZHOU ; Shihai ZHANG ; Hongjuan LIU ; Nan CHEN ; Chan LI ; Jilu SHEN ; Wanqi MEN ; Peng WANG ; Xiaowei ZHANG ; Yanyan LIU ; Yong AN
Chinese Journal of Infection and Chemotherapy 2024;24(3):277-286
Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5%were gram-positive and 70.5%were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3%,76.7%and 77.9%,respectively.Overall,94.0%of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8%of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2%in the isolates from children and 95.7%in the isolates from adults.The resistance rate to carbapenems was lower than 13.1%in most Enterobacterales species except for Klebsiella,21.7%-23.1%of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1%to 13.3%.The prevalence of meropenem-resistant strains decreased from 23.5%in 2019 to 18.0%in 2022 in Pseudomonas aeruginosa,and decreased from 79.0%in 2019 to 72.5%in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.
4.Evaluation of Renal Impairment in Patients with Diabetic Kidney Disease by Integrated Chinese and Western Medicine.
Yi-Lun QU ; Zhe-Yi DONG ; Hai-Mei CHENG ; Qian LIU ; Qian WANG ; Hong-Tao YANG ; Yong-Hui MAO ; Ji-Jun LI ; Hong-Fang LIU ; Yan-Qiu GENG ; Wen HUANG ; Wen-Hu LIU ; Hui-di XIE ; Fei PENG ; Shuang LI ; Shuang-Shuang JIANG ; Wei-Zhen LI ; Shu-Wei DUAN ; Zhe FENG ; Wei-Guang ZHANG ; Yu-Ning LIU ; Jin-Zhou TIAN ; Xiang-Mei CHEN
Chinese journal of integrative medicine 2023;29(4):308-315
OBJECTIVE:
To investigate the factors related to renal impairment in patients with diabetic kidney disease (DKD) from the perspective of integrated Chinese and Western medicine.
METHODS:
Totally 492 patients with DKD in 8 Chinese hospitals from October 2017 to July 2019 were included. According to Kidney Disease Improving Global Outcomes (KDIGO) staging guidelines, patients were divided into a chronic kidney disease (CKD) 1-3 group and a CKD 4-5 group. Clinical data were collected, and logistic regression was used to analyze the factors related to different CKD stages in DKD patients.
RESULTS:
Demographically, male was a factor related to increased CKD staging in patients with DKD (OR=3.100, P=0.002). In clinical characteristics, course of diabetes >60 months (OR=3.562, P=0.010), anemia (OR=4.176, P<0.001), hyperuricemia (OR=3.352, P<0.001), massive albuminuria (OR=4.058, P=0.002), atherosclerosis (OR=2.153, P=0.007) and blood deficiency syndrome (OR=1.945, P=0.020) were factors related to increased CKD staging in patients with DKD.
CONCLUSIONS
Male, course of diabetes >60 months, anemia, hyperuricemia, massive proteinuria, atherosclerosis, and blood deficiency syndrome might indicate more severe degree of renal function damage in patients with DKD. (Registration No. NCT03865914).
Humans
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Male
;
Diabetes Mellitus, Type 2
;
Diabetic Nephropathies
;
Hyperuricemia
;
Kidney
;
Proteinuria
;
Renal Insufficiency, Chronic/complications*
5.A case of combined oxidative phosphorylation deficiency 32 caused by MRPS34 gene variation and literature review.
Meng Xuan SHEN ; Xin Na JI ; Fan WU ; Yan Yan GAO ; Shuo FENG ; Li Na XIE ; Ping ZHENG ; Ying Ying MAO ; Qian CHEN
Chinese Journal of Pediatrics 2023;61(7):642-647
Objective: To investigate the clinical features and genetic features of combined oxidative phosphorylation deficiency 32 (COXPD32) caused by MRPS34 gene variation. Methods: The clinical data and genetic test of a child with COXPD32 hospitalized in the Department of Neurology, Children's Hospital, Capital Institute of Pediatrics in March 2021 were extracted and analyzed. A literature search was implemented using Wanfang, China biology medicine disc, China national knowledge infrastructure, ClinVar, human gene mutation database (HGMD) and Pubmed databases with the key words "MRPS34" "MRPS34 gene" and "combined oxidative phosphorylation deficiency 32" (up to February 2023). Clinical and genetic features of COXPD32 were summarized. Results: A boy aged 1 year and 9 months was admitted due to developmental delay. He showed mental and motor retardation, and was below the 3rd percentile for height, weight, and head circumference of children of the same age and gender. He had poor eye contact, esotropia, flat nasal bridge, limbs hypotonia, holding instability and tremors. In addition, Grade Ⅲ/6 systolic murmur were heard at left sternal border. Arterial blood gases suggested that severe metabolic acidosis with lactic acidosis. Brain magnetic resonance imaging (MRI) showed multiple symmetrical abnormal signals in the bilateral thalamus, midbrain, pons and medulla oblongata. Echocardiography showed atrial septal defect. Genetic testing identified the patient as a compound heterozygous variation of MRPS34 gene, c.580C>T (p.Gln194Ter) and c.94C>T (p.Gln32Ter), with c.580C>T being the first report and a diagnosis of COXPD32. His parents carried a heterozygous variant, respectively. The child improved after treatment with energy support, acidosis correction, and "cocktail" therapy (vitaminB1, vitaminB2, vitaminB6, vitaminC and coenzyme Q10). A total of 8 cases with COXPD32 were collected through 2 English literature reviews and this study. Among the 8 patients, 7 cases had onset during infancy and 1 was unknown, all had developmental delay or regression, 7 cases had feeding difficulty or dysphagia, followed by dystonia, lactic acidosis, ocular symptoms, microcephaly, constipation and dysmorphic facies(mild coarsening of facial features, small forehead, anterior hairline extending onto forehead,high and narrow palate, thick gums, short columella, and synophrys), 2 cases died of respiratory and circulatory failure, and 6 were still alive at the time of reporting, with an age range of 2 to 34 years. Blood and (or) cerebrospinal fluid lactate were elevated in all 8 patients. MRI in 7 cases manifested symmetrical abnormal signals in the brainstem, thalamus, and (or) basal ganglia. Urine organic acid test were all normal but 1 patient had alanine elevation. Five patients underwent respiratory chain enzyme activity testing, and all had varying degrees of enzyme activity reduction. Six variants were identified, 6 patients were homozygous variants, with c.322-10G>A was present in 4 patients from 2 families and 2 compound heterozygous variants. Conclusions: The clinical phenotype of COXPD32 is highly heterogenous and the severity of the disease varies from development delay, feeding difficulty, dystonia, high lactic acid, ocular symptoms and reduced mitochondrial respiratory chain enzyme activity in mild cases, which may survive into adulthood, to rapid death due to respiratory and circulatory failure in severe cases. COXPD32 needs to be considered in cases of unexplained acidosis, hyperlactatemia, feeding difficulties, development delay or regression, ocular symptoms, respiratory and circulatory failure, and symmetrical abnormal signals in the brainstem, thalamus, and (or) basal ganglia, and genetic testing can clarify the diagnosis.
Humans
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Male
;
Acidosis, Lactic
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Brain
;
Brain Stem
;
Dystonia
;
Dystonic Disorders
;
Mitochondrial Diseases
;
Infant
6.Clinical characteristics of epileptic seizure in neurofibromatosis type 1 in 15 cases.
Fan WU ; Xin Na JI ; Meng Xiao SHEN ; Shuo FENG ; Li Na XIE ; Yan Yan GAO ; Shu Pin LI ; Ai Yun YANG ; Jian Hua WANG ; Qian CHEN ; Xue ZHANG
Chinese Journal of Pediatrics 2023;61(12):1124-1128
Objective: To summarize the clinical characteristics of epileptic seizure associated with neurofibromatosis type 1 (NF1). Methods: From January 2017 to July 2023 at Children's Hospital Capital Institute of Pediatrics, medical records of patients with both NF1 and epileptic seizure were reviewed in this case series study. The clinical characteristics, treatment and prognosis were analyzed retrospectively. Results: A total of 15 patients(12 boys and 3 girls) were collected. Café-au-lait macules were observed in all 15 patients. There were 6 patients with neurodevelopmental disorders and the main manifestations were intellectual disability or developmental delay. The age at the first epileptic seizure was 2.5 (1.2, 5.5) years. There were various seizure types, including generalized tonic-clonic seizures in 8 patients, focal motor seizures in 6 patients, epileptic spasm in 4 patients, tonic seizures in 1 patient, absence in 1 patient, generalized myoclonic seizure in 1 patient and focal to bilateral tonic-clonic seizure in 1 patient. Among 14 patients whose brain magnetic resonance imaging results were available, there were abnormal signals in corpus callosum, basal ganglia, thalamus or cerebellum in 6 patients, dilated ventricles of different degrees in 3 patients, blurred gray and white matter boundary in 2 patients, agenesis of corpus callosum in 1 patient and no obvious abnormalities in the other patients. Among 13 epilepsy patients, 8 were seizure-free with 1 or 2 antiseizure medications(ASM), 1 with drug resistant epilepsy was seizure-free after left temporal lobectomy, and the other 4 patients who have received 2 to 9 ASM had persistent seizures. One patient with complex febrile convulsion achieved seizure freedom after oral administration of diazepam on demand. One patient had only 1 unprovoked epileptic seizure and did not have another seizure without taking any ASM. Conclusions: The first epileptic seizure in NF1 patients usually occurs in infancy and early childhood, with the main seizure type of generalized tonic-clonic seizure and focal motor seizure. Some patients have intellectual disability or developmental delay. Most epilepsy patients achieve seizure freedom with ASM.
Male
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Female
;
Humans
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Child, Preschool
;
Child
;
Neurofibromatosis 1/diagnosis*
;
Retrospective Studies
;
Intellectual Disability
;
Electroencephalography
;
Epilepsy/etiology*
;
Seizures/etiology*
7.Study on the Changes in Brain Function Characteristics of Chaihu Tongbian Decoction in Rats with Slow Transit Constipation and Depression Based on Resting-State Functional Magnetic Resonance Imaging
Jia-Li LIU ; Shun-Ming XIE ; Hui DAI ; Xing-Rui CHEN ; Li JI ; Shao-Liang LI ; Hai-Hua QIAN ; Dan ZHANG
Journal of Nanjing University of Traditional Chinese Medicine 2023;39(12):1189-1197
OBJECTIVE To observe the changes in brain function characteristics of Chaihu Tongbian Decoction in rats with slow transit constipation(STC)and depression using resting-state functional magnetic resonance imaging(rs-fMRI).METHODS 70 healthy SPF grade male SD rats were randomly divided into the blank group,model group,mosapride group,fluoxetine hydrochloride group,low(11.02 g·kg-1),medium(22.05 g·kg-1),and high(44.1 g·kg-1)dose Chaihu Tongbian Decoction groups.A rat model of STC with depression was constructed using compound diphenylephrine tablets combined with solitary confinement and chronic unpredictable mild stress(CUMS).Drugs were administered after successful modeling.The general condition of the rats was observed;24 h total number of fecal particles,fecal water content and intestinal carbon end advance rate were calculated;HE staining of the co-lon tissue was performed;the depressive-like behavior of the rats was detected.By comparing rs-fMRI amplitude of low-frequency fluctuation(ALFF)values,the differences in neuronal activity in the brains of rats in each group were explored.RESULTS Com-pared with the blank group,the 24 h total number of fecal particles,fecal water content and intestinal carbon end advance rate in the model group were significantly reduced(P<0.01).HE staining showed that the colon tissue lesions in the model group were severe.Open field experiment and sugar water consumption showed that the activity level of rats in the model group decreased(P<0.01),and behavioral changes like anxiety and depression appeared.The rs-fMRI results showed that compared with the blank group,the ALFF value of the right posterolateral hippocampus in the model group decreased and the ALFF value of the left amygdala increased(P<0.01).Compared with the model group,after 4 weeks of treatment,the 24 h total number of fecal particles,fecal water content,and intestinal carbon end advance rate in the mosapride group and each dose group of Chaihu Tongbian Decoction were im-proved(P<0.05);compared with the model group,after 4 weeks of treatment,the fluoxetine hydrochloride group and each dose group of Chaihu Tongbian Decoction could improve the anxiety and depression-like behavior of rats(P<0.05);compared with the model group,after 4 weeks of treatment,the fluoxetine hydrochloride group and the high-dose Chaihu Tongbian Decoction group could in-crease the ALFF value of the right posterolateral hippocampus and decrease the ALFF value of the left amygdala(P<0.05).CON-CLUSION Chaihu Tongbian Decoction can effectively relieve constipation and depressive symptoms in STC rats with depression,and its mechanism may be related to activating the right posterolateral hippocampus and inhibiting amygdala activity.
8.Evaluation of influencing factors and uncertainty of detection of trace uranium in drinking water using ultraviolet fluorescence
Yuhan XIE ; Liangliang YIN ; Yuxin QIAN ; Tingting XIA ; Yanqin JI
Chinese Journal of Radiological Medicine and Protection 2022;42(4):291-296
Objective:To achieve rapid and accurate detection of trace uranium in drinking water by analyzing the factors influencing the accuracy of uranium measurement in drinking water using ultraviolet fluorescence method and by evaluating the uncertainty in measurement.Methods:The influence of acidity, Fe 3+ and Mn 2+ contents on the analitical result were studied to optimize the measurement conditions. The accuracy of the measurement method was verified in 7 laboratories. By studying the errors introduced in the process of standard preparation, sample pretreatment and measurement, the sources of uncertainty were analyzed and the uncertainty was synthesized. Results:At pH 1-11 in aqueous solution, the linear regression coefficient of the standard curve was greater than 0.995, which was in line with the linear measurement range of the instrument. At pH 12 or so, the linear regression coefficient was 0.761, which could not meet the measurement requirements. At pH<3 or pH>10, the increase in fluorescence count was lower, which might increase the measurement error. At Fe 3+ concentration ≥15 mg/L, a large deviation occurred in measurement value that could affect seriously measurement result. At Mn 2+ concentration ≥ 1.6 mg/L, the sample produced white precipitation, which could affect the measurement accuracy. Three spiked water samples with different concentrations were determined in 8 laboratories. Each water sample was measured six times in parallel. The relative standard uncertainty of the result were 6.42×10 -2, 4.48×10 -2 and 5.26×10 -2 μg/L, and the expanded uncertainties were 0.03, 0.06 and 0.12 μg/L( k=2), respectively. Conclusions:The optimum conditions for the determination of uranium in water using this method pH were in samples 3-10, the concentration of Fe 3+ less than 15 mg/L, and the concentration of Mn 2+ less than or equal to 1.6 mg/L. The main sources of uncertainty in the measurement of uranium in water using ultraviolet fluorescence method arise from the repeated measurement error and the volume of added standard solution.
9.A cross-sectional study of prevalence of chronic kidney disease and related factors in adults in Anhui province.
Wei XU ; Xiu Ya XING ; Jing Qiao XU ; Dan CAO ; Qin HE ; Dan DAI ; Shang Chun JIA ; Qian Yao CHENG ; Yi Li LYU ; Luan ZHANG ; Ling LIANG ; Guo Die XIE ; Ye Ji CHEN ; Hua Dong WANG ; Zhi Rong LIU
Chinese Journal of Epidemiology 2022;43(11):1717-1723
Objective: To understand the prevalence of chronic kidney disease (CKD) and related factors in adults in Anhui province based on the data of Chinese Chronic Diseases and Nutrition Surveillance program (2018) in Anhui. Methods: Multi-stage stratified cluster random sampling was used to select participants aged ≥18 years. Moreover, questionnaire survey, body measurements and laboratory tests were conducted. The complex weighting method was used to estimate the prevalence of CKD in residents with different characteristics, and complex sampling data logistic regression model was used for multivariate analysis to identify related risk factors. Results: A total of 7 181 participants were included. The overall prevalence of CKD was 11.06% in adults in Anhui, and the prevalence was 12.49% in women and 9.59% in men (P<0.05). The moderate, high and very high risk for CKD progression were 8.66%, 2.02% and 0.38%, respectively. Multivariate analysis showed that age (OR=1.03, 95%CI: 1.00-1.05), BMI (OR=1.05, 95%CI: 1.01-1.09), being woman (OR=1.38,95%CI: 1.22-1.55), hypertension (OR=2.50, 95%CI: 1.76-3.56), diabetes (OR=2.28, 95%CI: 1.51-3.43), dyslipidemia (OR=1.26, 95%CI: 1.11-1.43) and hyperuricemia (OR=2.16, 95%CI: 1.68-2.78) were risk factors for CKD. Conclusion: The prevalence of CKD in adults in Anhui was relatively high and age, gender, BMI, hypertension, diabetes, dyslipidemia and hyperuricemia were found to be associated with the prevalence of CKD. To prevent CKD and its complications, attention should be paid to the management of related risk factors, including overweight and obesity, hypertension, diabetes, dyslipidemia and hyperuricemia.
Adult
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Male
;
Female
;
Humans
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Adolescent
;
Cross-Sectional Studies
;
Prevalence
;
Hyperuricemia/epidemiology*
;
Renal Insufficiency, Chronic/epidemiology*
;
Hypertension/epidemiology*
10.Study on source thickness and counting efficiency calibration for determining gross alpha activity in drinking water
Yuxin QIAN ; Liangliang YIN ; Yuhan XIE ; Yanqin JI
Chinese Journal of Radiological Medicine and Protection 2021;41(12):937-940
Objective:To study the influence of source thickness and counting efficiency calibration on the measurement of gross alpha activity in water.Methods:241Am and natural uranium reference materials were spiked in drinking water to prepare source on a planchet with different thickness, for counting alpha activity on the planchet. Results:The effective thickness measured by spiking 241Am or uranium standard solution in water sample was consistent with the empirical value of 4 mg/cm 2. The alpha counting rate was in a linear increase trend from 2A-5A mg/cm 2 and was basically stable and no longer increase when thickness was higher than 10A mg/cm 2 (A was area of planchet). The result calculated by effective thickness method and thick source method were in good agreement when thickness was 10A mg/cm 2. Conclusions:In order to reduce the deviation of gross alpha counting rate caused by the source thickness and counting efficiency calibration, the source thickness is recommended to be 10A mg/cm 2.

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