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.

Objective To investigate the main dietary patterns of children in urban areas of Maanshan City, and to explore the association between dietary patterns and subthreshold autism trait (SAT), attention-deficit/hyperactivity disorder (ADHD) symptoms and comorbid behaviors in 3-year-old children. Methods Based on the birth cohort of Maanshan Maternal and Infant Health from June 2015 to June 2016，regular physical examinations were conducted from 4 to 2 to 1, and follow-up was conducted until the age of 3. A semi-quantitative food frequency questionnaire was employed to assess dietary intakes. SAT and ADHD symptoms were assessed by Clancy autism behavior scale (CABS) and the 10-item Chinese version of the Conners Abbreviated Symptom Questionnaire (C-ASQ). Social-demographic information was also collected. Results The detection rates of SAT, ADHD symptoms, and comorbidity were 11.03%, 5.28%, and 2.71%, respectively. The older the father, the higher the mother's education level, and the higher the per capita monthly income of the family, the lower the SAT detection rate (P<0.05). The higher the father's educational level, the lower the detection rate of ADHD symptoms (P<0.05). The older the mother and the higher the education level, the lower the detection rate of comorbid behavior in their children (P <0.05). After adjusting for demographic influencing factors, the low intake level was used as a reference. The vegetarian type with moderate intake level was negatively correlated with SAT, while the processed food type with high intake level was positively correlated with SAT. The vegetarian type with high intake level was negatively correlated with ADHD symptoms, while the snack type with high intake level was positively correlated with ADHD symptoms. The vegetarian type with high intake level was negatively correlated with comorbidity. Conclusion Unhealthy dietary patterns are related to children's SAT and ADHD symptoms. Correcting children's unhealthy eating patterns may help reduce children's behavior problems.

Objective:To analyze the implementation effects of a medical laboratory talent training program based on local colleges and universities' applied talent-oriented cultivation principal as well as students' interests and industry needs.Methods:Based on the design principals of clarifying the professional orientation, meeting the national standard, reconstructing the curriculum system, introducing the spirit of innovation and entrepreneurship, and multi-dimensional collaborative education, as well as the reverse design path of the outcome-based education concept, we have built a medical laboratory applied talent training system focusing on humanity education, solid foundation, broad employment, and good competency and in accordance with the "three complete education" strategy, along with measures including creating an applied teaching atmosphere, developing an applied curriculum teaching model, providing vocational guidance and improving vocational identity, and promoting education via evaluation. The system was applied to the training and practice of students of grades 2021 and 2022 majoring in medical laboratory technology. SPSS20.0 software was used for statistical analysis.Results:With the concept of application-oriented talent training and the "four-in-one" practical teaching model, students' skills were improved, and the training path was broadened. Compared with those trained with the original program (grades 2019-2020), the graduates trained with the new program (grades 2021-2022) showed a significantly decreased employment rate in medical laboratory jobs in medical institutions from 71.25% to 42.86% ( χ2=12.36, P<0.001), a significantly increased employment rate in in-vitro diagnostics industry from 3.75% to 17.14% ( χ2=7.44, P<0.05), and a significantly increased rate of applying for postgraduate education from 17.05% to 32.86% ( χ2=4.74, P<0.05). Conclusions:The medical laboratory talent training program based on the talent training principal of local colleges and universities combined with students' interests and industry needs can help improve the quality of talent training and broaden the employment path of graduates.

BACKGROUND: Scleroderma is a multisystem disease in which tissue fibrosis is caused by inflammation and vascular damage. The mortality of scleroderma has remained high due to a lack of effective treatments. However, exosomes derived from human umbilical cord mesenchymal stem cells (HUMSCs)-Ex have been regarded as potential treatments for various autoimmune diseases, and may also act as candidates for treating scleroderma. METHODS: Mice with scleroderma received a single 50 lg HUMSCs-Ex. HUMSCs-Ex was characterized using transmission electron microscopy, nanoparticle tracking analysis and nanoflow cytometry. The therapeutic efficacy was assessed using histopathology, immunohistochemistry, immunofluorescence, quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay and western blot. RESULTS: HUMSCs-Ex ameliorated the deposition of extracellular matrix and suppressed the epithelial-mesenchymal transition process, and the effects lasted at least three weeks. In addition, HUMSCs-Ex promoted M1 macrophage polarization and inhibited M2 macrophage polarization, leading to the restoration of the balance of M1/M2 macrophages. CONCLUSION We investigated the potential antifibrotic and anti-inflammatory effects of HUMSCs-Ex in a bleomycininduced mouse model of scleroderma. So HUMSCs-Ex could be considered as a candidate therapy for scleroderma.

Objective: To examine the effects of obesity and central obesity on hypertension, so as to provide insights into the prevention and control measures of hypertension. Methods: From September to December 2018, residents at ages of 35 to 75 years were sampled using the multi-stage random sampling method in Baiyin District, Baiyin City, Gansu Province, and subjected to questionnaire surveys and physical examinations. The interaction between obesity/central obesity and hypertension was evaluated using logistic regression analysis. The synergy index ( SI ), relative excess risk due to interaction ( RERI ) and attributable proportion due to interaction ( AP ) were calculated using Excel compiled by Andersson et al. Results: A total of 6 246 questionnaires were allocated and 6 169 valid questionnaires were recovered, with an effective recovery rate of 98.77%. The respondents included 3 038 men ( 49.25% ) and 3 131 women (50.75%), with a mean age of ( 52.05±8.78 ) years. There were 832 respondents with obesity ( 13.49% ) and 2 278 with central obesity ( 36.93% ). The crude and standardized prevalence rates of hypertension were 35.89% and 33.05%, respectively. Multivariable logistic regression analysis showed that obesity ( OR=2.020, 95%CI: 1.705-2.393 ) and central obesity ( OR=1.622, 95%CI: 1.433-1.836 ) were statistically associated with hypertension. There was no multiplicative interaction between obesity or central obesity and hypertension ( OR=1.011, 95%CI: 0.655-1.560 ), and no additive interaction was detected between obesity or central obesityand hypertension ( SI=1.405, 95%CI: 0.815-2.424; RERI=0.658, 95%CI: -0.298 to 1.614; AP=0.201, 95%CI: -0.075 to 0.476 ). Conclusions Obesity and central obesity increase the risk of hypertension; however, no interaction is detected between obesity or central obesity and hypertension.

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.

Objective:To analyze the clinical characteristics of Group A Streptococcal(GAS) toxic shock syndrome (STSS) in children. Methods:The clinical data of 10 STSS children hospitalized in Shenzhen Children′s Hospital from January 2015 to March 2022 were downloaded from the electronic medical record system.The clinical manifestations were analyzed and treatment experience was summarized respectively.Results:There were 5 males and 5 females, with an average age of (5.29±2.87) years.All the patients were healthy in the past.The diagnoses were confirmed by blood culture in 2 cases, pus culture in 5 cases, and blood metagenomics next generation sequencing in 3 cases.The rapid detection of GAS antigen was positive in 7 cases.All cases had fever, and 9 cases of them developed fever after viral infection, including pneumonia in 7 cases, skin and soft tissue infections in 6 cases, necrotizing fasciitis in 3 cases, and purulent meningitis in 1 case.All cases also presented with shock.Six cases had liver function injury, and 4 cases suffered from acute kindey injury.Four cases had infection-related encephalopathy, and 7 cases were afflicted with disseminated intravascular coagulation.Two cases had respiratory failure, and 2 cases had rhabdomyolysis.There were 3 cases with a decreased white blood cell (WBC) count and 7 cases with an increased WBC count on admission.Seven cases were found to have thrombocytopenia, but their platelet levels were all elevated after recovery.C-reactive protein and procalcitonin and the proportion of neutrophils were markedly increased in all cases.All cases suffered from hypoalbuminemia, hyponatremia and hypocalcemia.All the 10 positive strains were sensitive to Penicillin, Ceftriaxone/Cefotaxime and Vancomycin.Eight cases were treated with combined antibiotics after admission.Eight patients received intravenous immunoglobulin.All cases were cured and discharged.Conclusions:The STSS progresses rapidly in children, so pediatricians should pay great attention to the disease.Early identification, diagnosis of infection sources, infusion of antibiotics and surgical treatment are the keys to disease management.

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.

Objective:To analyze the associations between prenatal and 1-year-old exposure to antibiotics and allergic symptoms in children aged 6-11 months and 18-23 months.Methods:In this study, a prospective birth cohort study was adopted. A total of 2 122 pregnant women were enrolled in Maternal and Child Health Care Center of Ma′anshan from June 2015 to June 2016, and they were followed up from the beginning of pregnancy to children′s 24 months of age. Excluding 564 pairs of mothers and children who were lost to follow-up or with incomplete information on the use of antibiotics and children′s allergic symptoms, a total of 1 558 pairs of mothers and children were included in the analysis of this study. The parents and children′s general demographic information, early-life antibiotic exposure and other data were collected, the information about allergic symptoms in children aged 6-11 months and 18-23 months were investigated by reference to the "International Study of Asthma and Allergies in Childhood (ISAAC)". The univariate and multivariate binary unconditional logistic regression model was used to was used to estimate associations between the effects of early-life antibiotic exposure on allergic symptoms in 2-year-old children.Results:The antibiotic usage rate of pregnant women during pregnancy was 3.4% (53), and the antibiotic usage rates of children between 0 to 2 months, 3 to 5 months, and 6 to 11 months were separately 15.2%(237), 15.5%(242) and 17.3%(269). The total prevalence of allergic diseases in children aged 6 to 11 months was 24.1% (375 children), and the total prevalence of allergic diseases in children aged 18 to 23 months was 22.0% (342 children). After adjust parental (maternal) education level, family monthly income per capita, parental (maternal) allergy history, parental (maternal) age at pregnancy, mother′s Body Mass Index (BMI) before pregnancy, exposure to second-hand smoke during pregnancy, delivery method, child gender, birth weight, preterm birth, the use of antibiotics when children were 3-5 months old ( RR=1.61,95% CI:1.19-2.17) and 6-11 months old ( RR=1.43,95% CI:1.06-1.93) were the risk factors for allergic symptoms at 6-11 months of age; and the use of antibiotics when children were 0-2 months old (RR=1.41, 95% CI: 1.03-1.95), 3-5 months old ( RR=1.54, 95% CI: 1.12-2.11) and 6-11 months old ( RR=1.58, 95% CI: 1.17-2.14) were the risk factors for allergic symptoms at 18-23 months of age. Conclusion:Children′s exposure to antibiotics within 1 year of age was a risk factor for allergic symptoms in children aged 6-11 months and 18-23 months, children should avoid unnecessary antibiotic use in infancy.

Objective:To analyze the associations between prenatal and 1-year-old exposure to antibiotics and allergic symptoms in children aged 6-11 months and 18-23 months.Methods:In this study, a prospective birth cohort study was adopted. A total of 2 122 pregnant women were enrolled in Maternal and Child Health Care Center of Ma′anshan from June 2015 to June 2016, and they were followed up from the beginning of pregnancy to children′s 24 months of age. Excluding 564 pairs of mothers and children who were lost to follow-up or with incomplete information on the use of antibiotics and children′s allergic symptoms, a total of 1 558 pairs of mothers and children were included in the analysis of this study. The parents and children′s general demographic information, early-life antibiotic exposure and other data were collected, the information about allergic symptoms in children aged 6-11 months and 18-23 months were investigated by reference to the "International Study of Asthma and Allergies in Childhood (ISAAC)". The univariate and multivariate binary unconditional logistic regression model was used to was used to estimate associations between the effects of early-life antibiotic exposure on allergic symptoms in 2-year-old children.Results:The antibiotic usage rate of pregnant women during pregnancy was 3.4% (53), and the antibiotic usage rates of children between 0 to 2 months, 3 to 5 months, and 6 to 11 months were separately 15.2%(237), 15.5%(242) and 17.3%(269). The total prevalence of allergic diseases in children aged 6 to 11 months was 24.1% (375 children), and the total prevalence of allergic diseases in children aged 18 to 23 months was 22.0% (342 children). After adjust parental (maternal) education level, family monthly income per capita, parental (maternal) allergy history, parental (maternal) age at pregnancy, mother′s Body Mass Index (BMI) before pregnancy, exposure to second-hand smoke during pregnancy, delivery method, child gender, birth weight, preterm birth, the use of antibiotics when children were 3-5 months old ( RR=1.61,95% CI:1.19-2.17) and 6-11 months old ( RR=1.43,95% CI:1.06-1.93) were the risk factors for allergic symptoms at 6-11 months of age; and the use of antibiotics when children were 0-2 months old (RR=1.41, 95% CI: 1.03-1.95), 3-5 months old ( RR=1.54, 95% CI: 1.12-2.11) and 6-11 months old ( RR=1.58, 95% CI: 1.17-2.14) were the risk factors for allergic symptoms at 18-23 months of age. Conclusion:Children′s exposure to antibiotics within 1 year of age was a risk factor for allergic symptoms in children aged 6-11 months and 18-23 months, children should avoid unnecessary antibiotic use in infancy.