Objective To experimentally verify the precision and accuracy of determining tritiated water in ambient air using the desiccant adsorption sampling–high temperature negative pressure desorption of liquid water (containing HTO)–liquid Scintillation counter method, and to provide technical support for developing standard methods for monitoring tritiated water in ambient air. Methods The relative standard deviation and recovery of multi-group samples were verified by collecting, testing, and analyzing environmental samples with different activity concentrations. The uncertainty of the method was evaluated, the main uncertainty components were identified, and the reliability of measurement results was analyzed. Through experimental comparison of different methods, the differences in the test results of different methods were examined. Results The relative standard deviation of multiple samples ranged from 6.7% to 7.9%, the recovery ranged from 95.7% to 97.3%, and the uncertainty was greatly affected by the sample counting rate, with no significant difference as compared to condensation sampling method. Conclusion The precision and accuracy of this method meet the requirements of environmental authorities for monitoring tritiated water in ambient air, and it can be widely used in the monitoring of tritiated water in ambient air.

Objective:To analyze pathogenic characteristics of viral diarrhea in children aged <5 years in Hebei Province and provide reference for the prevention and control of viral diarrhea in children.Methods:Stool samples were collected from in-patients with diarrhea under five years old from sentinel hospitals in Lulong County of Hebei between 2010 and 2020. ELISA detected rotavirus antigen, and then positive samples were genotyped by semi nested reverse transcription PCR of two rounds. Calicivirus, genotyping astrovirus, and adenovirus were detected by real-time fluorescence quantification PCR. The data were analyzed by using software SPSS 20.0.Results:In 2 925 detected stool samples, 1 919 (65.61%) were positive. The positive rates of rotavirus, calicivirus, adenovirus, and astrovirus were 42.80% (1 252/2 925), 22.12% (647/2 925), 6.19% (181/2 925), 3.56% (104/2 925). Viral diarrhea was mainly caused by rotavirus infection, accounting for 59.30% (1 017/1 715) between 2010 and 2017, and by calicivirus infection accounting for 53.43% (109/204) between 2018 and 2020. The peak positive rate of rotavirus occurred in winter, with the highest rate in infants aged 12 to 17 months (52.96%,483/912). In the rotavirus positive samples, G9P[8] was mainly detected strains (58.31%,730/1 252), followed by G3P[8] (8.15%,102/1 252). The calicivirus-positive samples were mainly infected with norovirus GⅡ. Sequence analysis indicated that the main type was GⅡ.4 [P31] between 2011 and 2016 and GⅡ.3 [P12] in 2018.Conclusions:Rotavirus and calicivirus were the main pathogens causing infant diarrhea in children under five years old in Hebei from 2010 to 2020. Winter was the main epidemic season.

Objective To explore the clinical effect of a trapezoidal transparent corneal incision during phacoemulsi-fication.Methods A total of 57 patients(68 eyes)undergoing phacoemulsification were selected and divided into a con-ventional incision group and a trapezoidal incision group using a random number table method.There were 28 patients(34 eyes)in the conventional incision group,including 15 eyes(males)and 19 eyes(females),with an age range of 41-82(65.0±10.1)years;and there were 29 patients(34 eyes)in the trapezoidal incision group,including 21 eyes(males)and 13 eyes(females),with an age range of 46-87(66.0±11.1)years.All patients underwent cataract phacoemulsification combined with intraocular lens(IOL)implantation.A 3.0 mm transparent corneal incision was made for patients in the conventional incision group,while an improved trapezoidal transparent corneal incision was made for patients in the trape-zoidal incision group.The uncorrected visual acuity,intraocular pressure,corneal astigmatism,and incidence of intraoper-ative and postoperative complications were compared between the two groups.Results The uncorrected visual acuity of patients in the trapezoidal incision group was better than that of patients in the conventional incision group at 1 week and 3 months after surgery,and the differences were statistically significant(both P＜0.05).There was no statistically significant difference in intraocular pressure and corneal astigmatism between the two groups of patients at 1 week,1 month,and 3 months after surgery(all P＞0.05).The number of eyes with anterior chamber collapse and the number of eyes requiring a watertight incision in the conventional incision group were greater than those in the trapezoidal incision group during sur-gery,and the differences were statistically significant(both P＜0.05).The number of eyes with incision edema and the number of eyes with incision gap in the conventional incision group were greater than those in the trapezoidal incision group after surgery,and the differences were statistically significant(both P＜0.05).In the conventional incision group,IOL was displaced in 18 eyes due to the shallow anterior chamber and then returned to normal after the formation of the anterior chamber through a watertight incision during surgery;during the formation,iris prolapse and incarceration occurred in 2 eyes,and IOL rotation or incarceration occurred in 3 eyes.In the trapezoidal incision group,3 eyes had a shallow anterior chamber after surgery,and a watertight incision was used to form the anterior chamber;there was no IOL incarceration or displacement or iris prolapse.Conclusion The improved trapezoidal transparent corneal incision can effectively prevent IOL displacement caused by anterior chamber collapse during cataract surgery while ensuring the stability of the anterior chamber.It can also reduce the related complications caused by the watertight incision using a flushing needle and restore patients'vision as early as possible.

Objective:To explore the lag effect and correlation between daily average temperature and the incidence of other infectious diarrhea in Hebei Province.Methods:The data of meteorological factors (including temperature and average daily temperature) and the daily incidence of other infectious diarrhea in Zhangjiakou City, Chengde City, Tangshan City, Qinhuangdao City, Baoding City, Langfang City, Cangzhou City, Shijiazhuang City, Hengshui City, Xingtai City, and Handan City in Hebei Province from 2017 to 2020 were collected. Eleven prefecture-level cities were divided into four regions, including east, north, middle and south regions. Distributed lag non-linear model was applied to examine the non-linear associations and the lag effect of daily mean temperature on daily incidence of other infectious diarrhea. Meanwhile, the cold and hot effects were used to estinuate the lag-response relationship on the incidence of other infectious diarrhea.Results:A total of 231 008 cases of other infectious diarrhea were reported in Hebei Province. The seasonal distribution was obvious, showing a bimodal distribution of large peaks in summer and small peaks in winter. An inverse S-shaped association between average daily temperature and cumulative risk ratio ( RR) of other infectious diarrhea was observed in Hebei Province. Both high temperature (higher than 27.50 ℃) and low temperature (less than 13.67 ℃) could increase the risk of other infectious diarrhea. When the temperature was lower than 13.00 ℃, the lag time and RR had a U-shaped association (lag four to seven days, 23 to 30 days). Meanwhile, when it was higher than 13.00 ℃, it had an inverted U-shaped association (lag 5 to 21 days). A comparison of four regions of Hebei Province showed that the lag time from south to north was extended from six days to 30 days at low temperature effects with temperature P5=-7.24 ℃. When the temperature getting hot ( P95=28.25 ℃), the risk occurred at lag 0 days, and the lag time gradually got short from north to south. Thus, the high temperature effect reached maximum quickly with a relative short duration. Conclusions:The inverse S-shaped non-linear association between daily average temperature and the incidence of other infectious diarrhea in Hebei Province is observed. Both low temperature and high temperature are associated with increased risk of other infectious diarrhea. But the impact of low temperature is more notable, which has a relative long duration.

Objective To optimize the measurement and analysis method for carbon-14 in environmental biological samples, and to provide technical support for the formulation of standard methods for carbon-14 measurement in environmental biological samples. Methods Through the optimization research on the carbon dioxide absorption method, the moisture content and carbon content of biological samples were measured with the moisture meter and the element analyzer according to the simplified personnel operation and the optimized process steps of the method, and intra- and inter-laboratory validation of the method was carried out. Results Under typical conditions, the lower limit of detection of the method reached 3 Bq/kg, and there were a relative standard deviation within laboratories of less than 17% and a relative standard deviation between laboratories of less than 14%, with a relative error of less than 19%. Most of the sample pretreatment was directly completed by the instrument and equipment, which improved the precision and accuracy of the measurement of moisture content and carbon content in samples, and reduced the influence of experiment personnel’s operation differences on the test results. Conclusion The lower limit of detection, precision, and accuracy of the optimized method meet the relevant requirements for the determination of carbon-14 in biological samples.

Objective:To understand the influence and lag effect of meteorological factors on the incidence of hand, foot and mouth disease (HFMD) in Shijiazhuang.Methods:The daily incidence data of HFMD in Shijiazhuang during 2017-2019 were collected from Chinese Information System for Disease Control and Prevention. The hourly meteorological data were collected form meteorological stations of Shijiazhuang of Chinese meteorological data network. The distributed lag nonlinear model was built for statistical analysis by software R 3.6.2.Results:When the daily average temperature was 15-26 ℃, the risk of incidence of HFMD increased at lag 3-6 days. However, the risk was highest when the temperature was 25 ℃ at lag 3 days ( RR=1.03,95% CI:1.00-1.06). When the daily average relative humidity was more than 80%, the risk of incidence of HFMD increased at lag 5-18 days. However, the risk was highest at lag 9 days ( RR=1.04, 95% CI: 1.02-1.06).When the daily average air pressure ranged from 999 hPa to 1 007 hPa, the risk of incidence of HFMD increased at lag 5-8 days. However, the risk was highest at lag 6 days ( RR=1.01, 95% CI: 1.00-1.02).When the daily average precipitation ranged from 15 to 32 mm, the risk of incidence of HFMD increased at lag 3-18 days. However, the risk was highest at lag 6 days ( RR=1.11, 95% CI: 1.02-1.19). Conclusions:Meteorological factors increased the risk of incidence of HFMD such as higher daily average temperature (15-26 ℃), higher daily average humidity (>80%), lower daily average air pressure (999-1 007 hPa) and higher daily average precipitation (15-32 mm) in Shijiazhuang during 2017-2019. They were all correlated with the incidence of HFMD with certain lag days. It is suggested to use these meteorological indicators for the early warning of HFMD.

Objective:To explore the incidence rates, clinical features, risk factors and its impacts on survival of central nervous system complications (CNSC) after allogeneic hematopoietic stem cell transplantation (allo-HSCT).Methods:From June 2011 to October 2018, 237 consecutive patients undergoing allo-HSCT were retrospectively analyzed.Results:The incidence of CNSC was 10.5%(25/237) and the median time 82(-4 - 810) days post-transplantation. The most common instances of CNSC were drug-associated encephalopathy (n=6), CNS infection (n=5), unexplained convulsions (n=4), metabolic encephalopathy (n=3), immune-related encephalopathy (n=3), primary central relapse (n=3) and cerebrovasculopathy (n=1). The most common clinical symptom was epileptic seizure (n=11). CsA-related encephalopathy was manifested mainly as posterior reversible encephalopathy syndrome on brain MRI. Metabolic encephalopathy is mostly demyelination. Most hippocampal lesions were caused by immune-related encephalopathy or CNS infection. Analysis of risk factors indicated that umbilical cord blood transplantation, HLA incompatible transplantation and delayed platelet implantation were high risk factors for post-transplantation occurrence of CNSC. Survival analysis suggested that non-relapse mortality rate (42.9%, 9/21) in group with CNSC of malignant hemoblastosis was higher than that in group without CNSC (15.3%, 27/176) and inter-group difference was statistically significant ( χ2=9.511, P=0.005). The 1/3-year OS rates in group with CNSC were lower than those in group without CNSC (56.6% vs 77.8%; 37.1% vs 65.7%). And the difference was statistically significant ( P=0.022). Conclusions:With a complex etiology, CNSC is one of serious complications after allo-HSCT and it significantly reduces the overall survival rate of patients. Umbilical cord blood transplantation, HLA incompatible transplantation and delayed platelet implantation are high-risk groups for CNSC.

Objective:To understand the epidemiological characteristics of cases with severe and fatal hand, foot, and mouth disease (HFMD) caused by other enterovirus in Hebei province, 2013-2017. Genetic characteristics of the main pathogen cosackie virus A6 (CoxA6) were also analyzed to further clarifying the characteristics and rules of genetic evolution on this virus.Methods:Descriptive epidemiological methods were used to analyze the distribution of severe and fatal cases with HFMD caused by other enterovirus in Hebei, 2013-2017. The VP1 sequences of CoxA6 were phylogenetically analyzed, using the Mega 5.2 software package.Results:A total of 86 severe and fatal cases with HFMD caused by other enterovirus were reported, accounting for 1.12%, comparing to all the HFMD caused by other enterovirus. Cases began to rise in April, and peaked in May-July. 65.12% of the cases occurred in children between 1 and 5 years old. The sex ratio between male and female was 1.39∶1. A total of 93.02% of the cases were children outside the child care settings. A total of 39 positive strains were identified, with positive isolation rate as 45.35%. Phylogenetic analysis on the VP1 sequences of CoxA6 strains in this study revealed that CoxA6 strains belonged to sub-genotypes D3a and D3b.Conclusions:Severe and fatal HFMD cases that caused by other enterovirus in Hebei province was with seasonal feature, consistent with the overall trend of this disease, 2013-2017. No new evolutionary branch appeared in the CoxA6 strain.

OBJECTIVE： To investigate the improvement effects of external application of water extract from Picrasma quassioides on allergic contact dermatitis （ACD） model mice， and to provide reference for its further development and utilization. METHODS： A total of 48 mice were randomly divided into blank control group （normal saline）， model group （normal saline）， hydrocortisone group （positive control， about 0.15 g/ear） and water extract from P. quassioides low-dose， medium-dose and high-dose groups （0.15， 0.3， 0.6 g/ear， calculated by extract）， with 8 mice in each group. The mice were given medicine on ear at 8 a.m. and 4 p.m. for 7 d continuously. Except for blank control group， other groups were given acetone-olive oil solution containing 0.5％ 2，4-dinitrofluorobenzene （DNFB） on the abdomen of mice to induce ACD model. After 7 d medication， modeling group was given acetone-olive oil of 0.25％ DNFB on left ear to induce dermatitis. 24 h later， the pathological changes of left ear tissue were observed by naked eye and skin lesion was scored. The thickness difference and weight difference of left and right ears in mice were measured. The serum contents of IL-6 and IgE were determined. The pathomorphology changes of ear tissue were observed by microscope after HE staining. RESULTS： Compared with blank control group， the skin lesion score of left ear was increased significantly in model group （P＜0.01）； the thickness difference and weight difference of left and right ears， serum contents of IgE and IL-6 were increased significantly （P＜0.01）. Pathological changes were observed in left tissue of mice by microscope， such as lymphocytic infiltration， intercellular edema， erythrocyte exudation. Compared with model group， skin lesion score of left ear in mice was decreased significantly in hydrocortisone group and water extract from P. quassioides high-dose group （P＜0.05 or P＜0.01）； the thickness difference and weight difference of left and right ears in mice were decreased significantly in all administration groups （P＜0.01）. The serum contents of IgE and IL-6 in mice were decreased significantly in hydrocortisone group， water extract from P. quassioides medium-dose and high-dose groups （P＜0.01）； the inflammatory lesions of left ear in mice were alleviated to varying degrees in different administration groups. CONCLUSIONS： External application of water extract from P. quassioides has a good improvement effect on ACD model mice.

OBJECTIVE： To establish a method for simultaneous determination of 6 components in Chaihuang tablets， such as baicalin， wogonoside， baicalein， wogonin， saikosaponin a and saikosaponin d in Chaihuang tablets. METHODS： HPLC-DAD method was used to detect 3 batches of Chaihuang tablets from same manufacturers. The determination was performed on Agilent Eclipse XDB-C18 column with mobile phase consisted of acetonitrile-triethylamine phosphate aqueous solution （pH adjusted to 7.0， gradient elution） at flow rate of 1.0 mL/min. The detection wavelengths were set at 210 nm （saikosaponin a， saikosaponin d） and 277 nm （baicalin， wogonoside， baicalein， wogonin）. The column temperature was 30 ℃， and sample size was 5 μL. RESULTS： The linear ranges of baicalin， wogonoside， baicalein， wogonin， saikosaponin a and saikosaponin d were 0.379 5-7.590 4 μg，   0.082 96-1.659 2 μg， 0.039 39-0.787 8 μg， 0.040 72-0.814 4 μg， 0.040 45-0.809 0 μg， 0.038 63-0.772 6 μg （all r≥0.999 3）， respectively. The limits of detection were 0.008， 0.007， 0.005， 0.005， 0.020 and 0.018 μg/mL. The limits of quantitation were 0.025， 0.022， 0.015， 0.015， 0.060， 0.054 μg/mL. RSDs of precision， reproducibility and stability tests （48 h） were all lower than 1.5％ （n＝6）. Average recoveries were 98.46％， 97.06％， 100.90％， 96.13％， 96.91％， 96.57％ （RSD＜2.0％， n＝6）. CONCLUSIONS： Established method is simple， accurate and reproducible for 6 components in Chaihuang tablets， and can be used for quality control of the tablet.