Objective: With the development of global nuclear power, the discharge of tritium during nuclear power plant operation has raised concerns. This study provides basic data support for the assessment of tritium radioactivity levels in sea-water and seafood around nuclear power plants. Methods: This study selected the coastal waters near a nuclear power plant in China as the research area. A total of 15 surface seawater samples and three types of marine organisms (laver, oyster, and mullet) were collected to measure and analyze the tritium activity concentrations in seawater and marine organisms. Results: The tritium activity concentrations in seawater ranged from 1.54 to 3.55 Bq/L, with an average of 2.25 ± 0.70 Bq/L.In marine organisms, the tritium activity concentrations ranged from 1.1 to 1.6 Bq/L. The total dose rates of tritium to mullet and oyster were 6.93 × 10−7 μGy/h and 5.39 × 10−7 μGy/h, respectively. Conclusion Compared with tritium activity concentrations in adjacent waters, those in seawater near this nuclear power plant showed no significant increases, and the tritium content in marine organisms remained within normal ranges. The radiation doses of tritium in mullet and oyster did not pose a radiation hazard to these two organisms.

Objective:To analyze the status of respiratory pathogen detection and the clinical features in children with Mycoplasma pneumoniae pneumonia (MPP). Methods:A prospective, multicenter study was conducted to collect clinical data, including medical history, laboratory examinations and multiplex PCR tests of children diagnosed with MPP from 4 hospitals in China between November 15 th and December 20 th, 2023. The multiplex PCR results and clinical characteristics of MPP children in different regions were analyzed. The children were divided into severe and mild groups according to the severity of the disease. Patients in the severe group were further divided into Mycoplasma pneumoniae (MP) alone and Multi-pathogen co-detection groups based on whether other pathogens were detected besides MP, to analyze the influence of respiratory pathogen co-detection rate on the severity of the disease. Mann-Whitney rank sum test and Chi-square test were used to compare data between independent groups. Results:A total of 298 children, 136 males and 162 females, were enrolled in this study, including 204 children in the severe group with an onset age of 7.0 (6.0, 8.0) years, and 94 children in the mild group with an onset age of 6.5 (4.0, 7.8) years. The level of C-reactive protein, D-dimer, lactic dehydrogenase (LDH) were significantly higher (10.0 (5.0, 18.0) vs. 5.0 (5.0, 7.5) mg/L, 0.6 (0.4, 1.1) vs. 0.5 (0.3, 0.6) mg/L, 337 (286, 431) vs. 314 (271, 393) U/L, Z=2.02, 2.50, 3.05, all P<0.05), and the length of hospitalization was significantly longer in the severe group compared with those in mild group (6.0 (6.0, 7.0) vs. 5.0 (4.0, 6.0) d, Z=4.37, P<0.05). The time from onset to admission in severe MPP children was significantly shorter than that in mild MPP children (6.0 (5.0, 9.5) vs. 9.0 (7.0, 13.0) d, Z=2.23, P=0.026). All patients completed the multiplex PCR test, with 142 cases (47.7%) MPP children detected with 21 pathogens including adenovirus 25 cases (8.4%), human coronavirus 23 cases (7.7%), rhinovirus 21 cases (7.0%), Streptococcus pneumoniae 21 cases (7.0%), influenza A virus 18 cases (6.0%). The pathogens with the highest detection rates in Tianjin, Shanghai, Wenzhou and Chengdu were Staphylococcus aureus at 10.7% (8/75), adenovirus at 13.0% (10/77), adenovirus at 15.3% (9/59), and both rhinovirus and Haemophilus influenzae at 11.5% (10/87) each. The multi-pathogen co-detection rate in severe MPP children was significantly higher than that in mild MPP group (52.9% (108/204) vs. 36.2% (34/94), χ2=10.62, P=0.005). Among severe MPP children, there are 89 cases in the multi-pathogen co-detection group and 73 cases in the simple MPP group. The levels of LDH, D-dimer and neutrophil counts in the multi-pathogen co-detection group were significantly higher than those in the simple MPP group (348 (284, 422) vs. 307 (270, 358) U/L, 0.8 (0.5, 1.5) vs. 0.6 (0.4, 1.0) mg/L, 4.99 (3.66, 6.89)×10 9vs. 4.06 (2.91, 5.65)×10 9/L, Z=5.17, 4.99, 6.11, all P<0.05). Conclusions:The co-detection rate of respiratory pathogens, LDH and D-dimer in children with severe MPP were higher than those with mild MPP. Among severe MPP children the stress response of children in co-detection group was more serious than that of children with simple MPP.

Objective:To explore the consistency of peripheral whole blood and venous serum procalcitonin (PCT) levels, and the value of peripheral whole blood PCT in evaluating pediatric bacterial infection.Methods:This multicenter cross-sectional parallel control study was conducted in 11 children′s hospital. All the 1 898 patients older than 28 days admitted to these hospitals from March 2018 to February 2019 had their peripheral whole blood and venous serum PCT detected simultaneously with unified equipment, reagent and method. According to the venous serum PCT level, the patients were stratified to subgroups. Analysis of variance and chi-square test were used to compare the demographic characteristics among groups. And the correlation between the peripheral blood and venous serum PCT level was investigated by quantitative Pearson correlation analysis.The PCT resultes were also converted into ranked data to further test the consistency between the two sampling methods by Spearman′s rank correlation test. Furthermore, the ranked data were converted into binary data to evaluate the consistency and investigate the best cut-off of peripheral blood PCT level in predicting bacterial infection.Results:A total of 1 898 valid samples were included (1 098 males, 800 females),age 27.4(12.2,56.7) months. There was a good correlation between PCT values of peripheral whole blood and venous serum ( r=0.97 , P<0.01). The linear regression equation was PCT?venous serum=0.135+0.929×PCT peripheral whole blood. However, when stratified to 5 levels, PCT results showed diverse and unsatisfied consistency between the two sampling methods ( r=0.51-0.92, all P<0.01). But after PCT was converted to ordinal categorical variables, the stratified analysis showed that the coincidence rate of the measured values by the two sampling methods in each boundary area was 84.9%-97.1%. The dichotomous variables also showed a good consistency (coincidence rate 96.8%-99.3%, Youden index 0.82-0.89). According to the severity of disease, the serum PCT value was classified into 4 intervals（<0.5、0.5-<2.0、2.0-<10.0、≥10.0 μg/L）, and the peripheral blood PCT value also showed a good predictive value (AUC value was 0.991 2-0.997 9). The optimal cut points of peripheral whole blood PCT value 0.5、1.0、2.0、10.0 μg/L corresponding to venous serum PCT values were 0.395, 0.595, 1.175 and 3.545 μg/L, respectively. Conclusions:There is a good correlation between peripheral whole blood PCT value and the venous serum PCT value, which means that the peripheral whole blood PCT could facilitate the identification of infection and clinical severity. Besides, the sampling of peripheral whole blood is simple and easy to repeat.

Objective:To investigate the etiology of necrotizing pneumonia (NP) in children and the clinical characteristics of NP caused by different pathogens in China.Methods:A retrospective, case-control study was performed in children with NP who were admitted to 13 hospitals in China from January 2008 to December 2019. The demographic and clinical information, laboratory data, etiological and radiological findings were analyzed. The data were divided into three groups based on the following years: 2008-2011, 2012-2015 and 2016-2019, and the distribution characteristics of the pathogens in different period were compared. Meanwhile, the pathogens of pediatric NP in the southern and northern China were compared. And the clinical characteristics of the Mycoplasma pneumoniae (MP) NP and the bacterial NP were also compared. T-test or Mann-Whitney nonparametric test was used for comparison of numerical variables, and χ 2 test was used for categorical variables. Results:A total of 494 children with NP were enrolled, the median ages were 4.7 (0.1-15.3) years, including 272 boys and 222 girls. Among these patients, pathogens were identified in 347 cases and the pathogen was unclear in the remaining 147 cases. The main pathogens were MP (238 cases), Streptococcus pneumoniae (SP) (61 cases), Staphylococcus aureus (SA) (51 cases), Pseudomonas aeruginosa (13 cases), Haemophilus influenzae (10 cases), adenovirus (10 cases), and influenza virus A (7 cases), respectively. MP was the most common pathogen in all three periods and the proportion increased yearly. The proportion of MP in 2016-2019 was significantly higher than that in 2012-2015 (52.1% (197/378) vs. 36.8% (32/87), χ 2= 6.654, P=0.010), while there was no significant difference in the proportion of MP in 2012-2015 and that in 2008-2011 (36.8% (32/87) vs. 31.0% (9/29), χ2=0.314, P=0.575).Regarding the regional distribution, 342 cases were in the southern China and 152 in the northern China. Also, MP was the most common pathogen in both regions, but the proportion of MP was higher and the proportion of SP was lower in the north than those in the south (60.5% (92/152) vs. 42.7% (146/342), χ 2=13.409, P<0.010; 7.9% (12/152) vs. 14.3% (49/342), χ 2= 4.023, P=0.045). Comparing the clinical characteristics of different pathogens, we found that fever and cough were the common symptoms in both single MP and single bacterial groups, but chest pain was more common (17.0% (34/200) vs. 6.1% (6/98), χ 2=6.697, P=0.010) while shortness of breath and wheezing were less common in MP group (16.0% (32/200) vs. 60.2% (59/98), χ 2=60.688, P<0.01; 4.5% (9/200) vs. 21.4% (21/98), χ 2=20.819, P<0.01, respectively). The white blood cell count, C-reactive protein and procalcitonin in the bacterial group were significantly higher than those in the MP group (14.7 (1.0-67.1)×10 9/L vs. 10.5 (2.5-32.2)×10 9/L, 122.5 (0.5-277.3) mg/L vs. 51.4 (0.5-200.0) g/L, 2.13 (0.05-100.00) μg/L vs. 0.24 (0.01-18.85) μg/L, Z=-3.719, -5.901 and -7.765, all P<0.01). Conclusions:The prevalence of pediatric NP in China shows an increasing trend during the past years. MP, SP and SA are the main pathogens of NP, and the most common clinical symptoms are fever and cough. The WBC count, C-reactive protein and procalcitonin in bacterial NP are significantly higher than those caused by MP.

The school-age boy was admitted to Tianjin Children's Hospital for "fever and cough for 6 days".After detail examinations,the diagnosis of severe Mycoplasma pneumoniae pneumonia was proved.Treatments:anti-infection with Azithromycin and Meropenem;the obstruction of air way was relieved;assisted with symptomatic and supportive treatment.During the treatment,disorder of consciousness and hemiplegia of right limbs occurred,cerebral infarction was proved later by magnetic resonance angiography(MRA).Severe Mycoplasma pneumoniae pneumonia complicated with cerebral infarction is clinically rare with a high morbidity and mortality.Attention should be paid to body examination and Laboratory test.Multi-disciplinary cooperation is helpful.

Objective To evaluate the effect of inhaling hydrogen (H2) on proteomics during acute lung injury in septic mice.Methods Sixty male ICR mice,aged 6 weeks,weighing 20-25 g,were divided into 4 groups (n=15 each) using a random number table:sham operation group (Sh group),sham operation plus H2 group (Sh+H2 group),sepsis group (S group) and sepsis plus H2 group (S+H2 group).Sepsis was produced by cecal ligation and puncture.The mice in Sh+H2 and S+H2 groups inhaled 2％ H2 for 1 h starting from 1 and 6 h after operation.At 24 h after operation,lungs were removed for identification of proteins by isobaric tags for relative and absolute quantification and liquid chromatography-tandem mass spectrometry analysis,and the differentially expressed proteins were screened.The differentially expressed proteins were used for KEGG pathway enrichment analysis and STRING protein-protein interaction networks analysis.Western blot was used to confirm the 4 differentially expressed proteins semaphorin 7A,transferrin,OTULIN and mitogen-activated protein kinase kinase kinase 1.Results A total of 4 472 quantifiable proteins were identified.A total of 192 proteins which were related to acute lung injury during H2 inhalationinduced reduction of sepsis were identified.The 192 proteins involved phosphatidylinositol 3-kinase/serine0threonine kinase signaling pathway,chemokine signaling pathway,hypoxia-inducible factor 1 signaling pathway,complement and coagulation cascades,peroxisome proliferator-activated receptor signaling pathway and proteins including ribosome proteins,myosin and troponin,collagen and adhesion-related proteins,coagulation-related proteins found in STRING protein-protein interaction networks.Conclusion Inhaling H2 can induce changes in the expression of 192 proteins,which may be the mechanism of lung protection in septic mice.

Objective To evaluate the effect of hydrogen on mitochondrial dynamics during endotoxin-induced damage to human umbilical vein endothelial cells (HUVECs).Methods HUVECs cultured in vitro were seeded in the culture plate and divided into 4 groups using a random number table:control group (group C),hydrogen-saturated culture medium group (H group),endotoxin group (group E) and endotoxin + hydrogen-saturated culture medium group (group E+H).The cells were cultured in the plain culture medium in C and E groups.The cells were cultured in the hydrogen-saturated culture medium containing lipopolysaccharide (LPS) with the final concentration of 10 μg/ml in H and E+H groups.At 2,8 and 24 h of culture or incubation with LPS,the cell viability was detected by methyl thiazolyl tetrazolium assay,the intracellular ATP content was measured using the phosphomolybdic acid colorimetric method,and the expression of dynamin-related protein 1 (DRP1) was detected by using Western blot.The expression of DRP1 was detected by immunofluorescence at 8 h of incubation with LPS.Results Compared with group C,the cell viability and ATP content were significantly decreased,and the expression of DRP1 was up-regulated at each incubation time point in E and E +H groups (P＜0.05),and no significant change was found in the parameters mentioned above in group H (P＞0.05).Compared with group E,the cell viability and ATP content were significantly increased,and the expression of DRP1 was down-regulated at each incubation time point in group E+H (P＜0.05).Conclusion The mechanism by which hydrogen reduces endotoxin-induced damage to HUVECs is related to down-regulation of DRP1 expression and inhibition of excessive mitochondrial fission.

Objective To evaluate the role of autophagy in hydrogen-induced reduction of lung injury in septic mice.Methods Sixty pathogen-free healthy male ICR mice,aged 6 weeks,weighing 20-25 g,were divided into 5 groups (n =12 each) using a random number table:sham operation group (group Sh),sepsis group (group Sep),sepsis plus hydrogen group (group Sep+H2),sepsis plus autophagy inhibitor 3-methyladenine (3-MA) group (group Sep+3-MA) and sepsis plus 3-MA plus hydrogen group (group Sep+3-MA+H2).Sepsis was produced by cecal ligation and puncture.At 1 h before operation,3-MA 10 mg/kg was intraperitoneally injected.The mice inhaled 2％ H2 for 1 h starting from 1 and 6 h after operation.Blood samples were collected from the common carotid artery at 24 h after operation for measurement of arterial oxygen partial pressure,and the oxygenation index (OI) was calculated.Pulmonary specimens were obtained for examination of the pathological changes which were scored.Pulnonary mitochondria were isolated for determination of mitochondrial membrane potential (MMP) and ATP content using fluorescence spectrophotometry and a bioluminescence assay,respectively,and the respiratory control rate (RCR) was calculated.The expression of autophagy-related protein microtubule-associated protein 1 light chain 3 (LC3) was determined by Western blot,and the ratio of LC3-Ⅱ to LC3-Ⅰ expression (LC3-Ⅱ/LC3-Ⅰ ratio) was calculated.Results Compared with group Sh,the pathological scores were significantly increased,the OI and contents of mitochondrial RCR,MMP and ATP were decreased,and the LC3-Ⅱ/LC3-Ⅰ ratio was increased in Sep and Sep+H2 groups (P＜0.05).Compared with group Sep,the pathological scores were significantly decreased,the OI and contents of mitochondrial RCR,MMP and ATP were increased,and the LC3-Ⅱ/LC3-Ⅰ ratio was increased in group Sep+H2,and the pathological scores were significantly increased,the OI and contents of mitochondrial RCR,MMP and ATP were decreased,and the LC3-Ⅱ/LC3-Ⅰ ratio was decreased in group Sep+3-MA (P＜0.05),and no significant change was found in each parameter mentioned above in group Sep+3-MA+H2 (P＞0.05).Compared with group Sep+H2,the pathological scores were significantly increased,the OI and contents of mitochondrial RCR,MMP and ATP were decreased,and the LC3-Ⅱ/LC3-Ⅰ ratio was decreased in group Sep+3-MA+H2 (P＜0.05).Conclusion The mechanism by which hydrogen ameliorates lung injury is related to enhanced level of autophagy in septic mice.

Objective To evaluate the relationship between the endogenous protection induced by autophagy against acute lung injury and inflammatory responses in the septic mice.Methods A total of 130 pathogen-free male C57BL/6 mice,aged 6 weeks,weighing 20-25 g,were randomly divided into 5 groups (n =26 each) using a random number table:sham operation group (group S),sepsis group (group Sep),autophagy inducer rapamycin group (group Rap),autophagy inhibitor 3-methyladenine (3-MA) group (group 3-MA),and lysosome inhibitor bafilomycin group (group Baf).Sepsis was produced by cecal ligation and puncture in chloral hydrate-anesthetized mice.Rapamycin 10 mg/kg,3-MA 15 mg/kg,and bafilomycin 1 mg/kg were injected intraperitoneally at 1 h after operation in Rap,3-MA and Baf groups,respectively.Twenty mice in each group were selected and observed for the survival at 7 days after operation,and the 7-day survival rate was calculated.Six mice in each group were selected,and arterial blood samples were obtained at 24 h after operation,the mice were then sacrificed,and lung tissues were obtained for determination of the levels of tumor necrosis factor-alpha (TNF-α),high-mobility group box 1 (HMGB1),interleukin-6 (IL-6),IL-10 and monocyte chemotactic protein-1 (MCP-1) in serum and lung tissues by enzyme-linked immunosorbent assay.The expression of autophagy-related proteins microtubule-associated protein 1 light chain 3 Ⅱ (LC3 Ⅱ),Beclin-1 and lysosomal-associated membrane protein 2 (LAMP2),and Ras-related protein 7 (Rab7) in lung tissues was detected by Western blot.Results Compared with group S,the 7-day survival rate was significantly decreased,and the levels of TNF-α,HMGB1,IL-6,IL-10 and MCP-1 in serum and lung tissues and LC3 Ⅱ,Beclin-1,LAMP2 and Rab7 in lung tissues were significantly increased in group Sep (P＜0.05).Compared with group Sep,the 7-day survival rate and levels of IL-10,LAMP2 and Rab7 in serum and lung tissues were significantly increased in group Rap and decreased in 3-MA and Baf groups,and the levels of TNF-α,HMGB1,IL-6 and MCP1 in serum and lung tissues were significantly decreased in group Rap and increased in 3-MA and Baf groups,and the levels of LC3 Ⅱ and Beclin-1 in lung tissues were significantly increased in Rap and Baf groups and decreased in group 3-MA (P＜0.05).Conclusion Autophagy-induced endogenous protection against acute lung injury is related to inhibition of inflammatory responses in the septic mice.

Objective To explore the transport properties of the radionuclide strontium 90Sr in the soil-plant system,and discuss the accumulation characteristics of strontiumes in different vegetable tissues.Methods Three kinds of vegetables,including Chinese cabbage,radish and celery,were planted in this experiments using stable nuclide 88Sr instead of 90Sr.Strontium concentrations in these kinds of plant and soil were measured with inductively coupled plasma atomic emission spectrometry (ICP-AES),and the transportation factor (TF) of strontium and the concentration ratio (CR) of these plants were calculated.Results The contents of strontium in different tissues of the vegetables increased significantly in response to the strontium concentrations in soil (F =3.75-139.39,P ＜ 0.05).The contents of strontium at 398.33,477.99 and 557.57 mg/kg in different tissues of these vegetables were significantly higher than that in control group (t =-10.49-7.41,P ＜0.05).Except celery stems,there was a positive correlation about contents of the strontium between other tissues of these vegetables and their experimental soils (r =0.88-0.99,t =7.41-15.96,P ＜0.05).Based on dry weight of examples,the TF in each tissue sample of cabbage and radish was higher than 1,and the concentration ratio,for cabbage and radish,was higher in stems than in roots (F =8.22,91.49,P ＜ 0.05).Conclusions Three kinds of vegetables have been shown to have strontium accumulation ability in soil environment.