Objective To establish an alpha spectrometric method for the analysis of polonium-210 (²¹⁰Po) in seafood, determine the activity concentration of ²¹⁰Po in seafood from China’s eastern coastal areas, and assess the corresponding radiation doses. Methods A total of 21 types of seafood belonging to four categories (fish, shrimp, crab, and shellfish) were collected from eastern coastal cities in China. The activity concentration of ²¹⁰Po in different tissues of the seafood was analyzed using the ²⁰⁹Po tracer-α spectrometry method. The annual effective dose was then estimated by combining seafood consumption rates and dose conversion factors. Results The activity concentrations of ²¹⁰Po in the edible parts of fish, shrimp, and shellfish samples ranged from 0.65 to 17.89 Bq/kg, 0.81 to 5.95 Bq/kg, and 0.73 to 44.09 Bq/kg, respectively. In whole crab samples, the range was 1.77 to 11.43 Bq/kg. The activity concentration of ²¹⁰Po in crab samples (whole crab) ranged from 1.77 to 11.43 Bq/kg. ²¹⁰Po activity was mainly enriched in the head, internal organs, and shell. The annual effective ingestion dose for different age groups ranged from 91.39 to 251.33 μSv/a. Conclusion The annual effective dose resulting from ²¹⁰Po ingestion via seafood consumption for residents in China’s eastern coastal regions is lower than the annual effective dose reference level recommended by the IAEA.

The lung collaterals form a network that branches from the lung meridian, traversing the lung system and extending across the body′s surface. Lung collateral disease refers to the structural alterations or dysfunction in these collaterals caused by external or internal pathogens. Research into the structural and physiological functions of children′s lung collaterals, as well as the pathogenesis and syndrome differentiation for treating lung collateral diseases in children, holds significant value in guiding the prevention and treatment of pediatric respiratory conditions. Drawing on the theory of collateral disease, the clinical insights of both historical and contemporary physicians, and modern research findings—while considering the unique physiological and pathological characteristics of children′s respiratory systems—this study provides a foundational summary of the morphology and spatial distribution of children′s lung collaterals. The characteristics of these collaterals are highlighted as thin, sparse, short, narrow, brittle, and tender. From this structural understanding, the unique physiological functions of children′s lung collaterals are analyzed. The study further explores the interactions between pathogenic factors and lung collaterals, elucidating the pathogenesis and progression of children′s lung collateral diseases. It proposes treatment principles centered on "seeking treatment in the collaterals and employing the method of unblocking collaterals, "which align with the unique features of pediatric lung collaterals. Common treatment approaches, and relevant prescriptions for managing these diseases are summarized. This paper lays the foundation for a theoretical system encompassing the structure, function, pathogenesis, and syndrome differentiation for treating children′s lung collateral diseases. It offers valuable insights for the clinical diagnosis and management of pediatric respiratory diseases linked to collateral dysfunction and serves as a reference for the systematic development of a broader theoretical framework for children′s collateral diseases.

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.

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 develop a method for determining 14C in seafood using a tube combustion furnace (or oxygen bomb combustion devices) coupled with liquid scintillation counting (LSC), in order to accurately determine 14C in seafood. Methods:Four categories of seafood samples (i.e., fish, crustaceans, mollusks, and algae) were collected. They were then subjected to high-temperature oxidation using a tube combustion furnace or oxygen bomb combustion devices to isolate CO 2, followed by an analysis of the radioactivity concentration of 14C using LSC. The combustion conditions were optimized by investigating the heating nodes and rates in the oxidation combustion furnace, and the CO 2 collection conditions were optimized by placing a NaOH absorption solution in the oxygen bomb combustion devices. Additionally, the optimal measurement conditions were determined by comparing the effects of varying scintillation cocktails and the dark adaptation time of two preparation methods, i. e., the adsorption and suspension method. Results:When a tubular combustion furnace was used for oxidation and combustion, the optimal heating rate of the sample pyrolysis temperature zone was determined at 1.5℃/min. In this case, the combustion efficiency of various seafood could reach over 95%. When the oxygen bomb combustion devices were employed, placing NaOH solutions both inside and at the exhaust end increased absorption efficiency by 10% compared to the traditional practice of placing a NaOH solution only at the exhaust end. Samples prepared using the absorption method should be kept in the dark for at least 10 h before measurement using LSC, while samples prepared with the suspension methods should be kept for at least 20 h. The results obtained using two preprocessing devices and two sample preparation method were consistent, with a detection limit of 9.10 Bq/kg (dry samples). Compared to the suspension method (The relative standard deviation of the results obtained by two preprocessing devices were 9.00% and 8.27%), the absorption method (the corresponding relative standard deviation were 3.61% and 3.29%) exhibited higher precision in repeated measurements.Conclusions:The aforementioned pretreatment devices and sample preparation method are suitable for determining 14C in seafood.

Objective:To develop a method for determining 14C in seafood using a tube combustion furnace (or oxygen bomb combustion devices) coupled with liquid scintillation counting (LSC), in order to accurately determine 14C in seafood. Methods:Four categories of seafood samples (i.e., fish, crustaceans, mollusks, and algae) were collected. They were then subjected to high-temperature oxidation using a tube combustion furnace or oxygen bomb combustion devices to isolate CO 2, followed by an analysis of the radioactivity concentration of 14C using LSC. The combustion conditions were optimized by investigating the heating nodes and rates in the oxidation combustion furnace, and the CO 2 collection conditions were optimized by placing a NaOH absorption solution in the oxygen bomb combustion devices. Additionally, the optimal measurement conditions were determined by comparing the effects of varying scintillation cocktails and the dark adaptation time of two preparation methods, i. e., the adsorption and suspension method. Results:When a tubular combustion furnace was used for oxidation and combustion, the optimal heating rate of the sample pyrolysis temperature zone was determined at 1.5℃/min. In this case, the combustion efficiency of various seafood could reach over 95%. When the oxygen bomb combustion devices were employed, placing NaOH solutions both inside and at the exhaust end increased absorption efficiency by 10% compared to the traditional practice of placing a NaOH solution only at the exhaust end. Samples prepared using the absorption method should be kept in the dark for at least 10 h before measurement using LSC, while samples prepared with the suspension methods should be kept for at least 20 h. The results obtained using two preprocessing devices and two sample preparation method were consistent, with a detection limit of 9.10 Bq/kg (dry samples). Compared to the suspension method (The relative standard deviation of the results obtained by two preprocessing devices were 9.00% and 8.27%), the absorption method (the corresponding relative standard deviation were 3.61% and 3.29%) exhibited higher precision in repeated measurements.Conclusions:The aforementioned pretreatment devices and sample preparation method are suitable for determining 14C in seafood.

Objective To investigate the effect of MALAT1 expressions on cell proliferation and apoptosis in astrocytes by regulating mitogen-activated protein kinase(MAPK)/extracellular signal-regulated kinase(ERK1,2)pathway.Methods The MALAT1 gene was knocked down and over-expressed in C8-D1A cells by lentiviral and plasmid vectors,respectively.The expressions of MALAT1,cell proliferation-related markers(Ki67,MCM2,PCNA)and apoptosis-related proteins(Caspase-3,Bax,Bcl-2)were detected by quantitative real-time polymerase chain reaction(qPCR).CCK-8 assay and flow cytometry were used for cell proliferation and apoptosis in C8-D1A cells.Immunofluorescence was adopted to detect the protein expressions of Caspase-3 and Ki67.Western blotting was used to detect the protein expressions of Caspase-3,Bax,Bcl-2,ERK1/2,p-ERK1/2,p38MAPK and p-p38MAPK.Results Compared with the control group,over-expressed MALAT1 inhibited cell proliferation and induced cell apoptosis in C8-D1A cells while the knockdown of MALAT1 significantly enhanced cell proliferation and anti-apoptotic ability in C8-D1A cells.The proportion of C8-D1A cells in G0/G1-phase and G2/M-phase was higher than in the control group as evidenced by flow cytometry,but was lower in S-phase.Meanwhile,data showed that Caspase-3 was increased while p-ERK1/2 was decreased in terms of protein levels.The mRNA expressions of Ki67 and PCNA were decreased.After knockdown of MALAT1,the proportion of C8-D1A cells in S-phase was higher,but was lower in G2/M-phase.The protein expressions of Caspase-3 and Bax decreased while those of p-ERK1/2 and p-p38MAPK increased.The mRNA expressions of Ki67,MCM2 and PCNA were increased.The differences were all statistically significant(P＜0.05).Conclusion MALAT1 promotes astrocyte apoptosis and inhibits proliferation by regulating the MAPK/ERK1,2 signaling pathway.

Objective:To quantitatively analyze the differences in image quality and generated synthetic-computed tomography(sCT)between cone beam CT(CBCT)and iteration CBCT(iCBCT),which based on filtered back projection(FBP)and iterative reconstruction(IR)techniques of Varian Ethos adaption system.Methods:Using the special Catphan604 phantom of the test of CT image quality,five times of scanning series of CBCT and iCBCT were respectively performed based on thoracic and abdominal scanning protocols,so as to obtain four sets of images,and each set of image included the CBCT image,the composited sCT and iCBCT images based on CBCT,the composited sCT bases on iCBCT.The noise power spectrum(NPS),image uniformity(UI),modulation transfer function(MTF),low-contrast visibility(LCV)and contrast-to-noise ratio(CNR)of them were analyzed.Additionally,a retrospective analysis was conducted on images of six patients who underwent clinical radiotherapy,and the images of them were obtained by using thoracic and abdominal scanning protocols.The sCT images,which were generated by deformable registrations on the basis of CBCT and iCBCT,were analyzed,and they were compared with located CT images,and their mean absolute error(MAE)and root mean square error(RMSE)were further quantitatively analyzed.Results:Compared to CBCT,iCBCT significantly reduced NPS(thoracic images reduced by 0.08,abdominal images reduced by 0.06).The UI values of thoracic images and abdominal images of iCBCT were respectively 0.37 and 0.28,and those of CBCT were respectively 0.65 and 0.39.The LCV values of thoracic images and abdominal images of iCBCT were respectively 0.67 and 0.56,and those of CBCT were respectively 0.93 and 0.90.The MTF50％were 0.28 lp/mm except abdominal image of iCBCT was 0.29 lp/mm.The resolution rate of high contrast between iCBCT and CBCT was basic consistency.The differences of similarity analysis of the generated sCT and located CT bases on CBCT and iCBCT was no significant(P＞0.05).Conclusion:The image quality of iCBCT is superior to conventional CBCT.The accuracy of CT value of generated sCT bases on CBCT and iCBCT can meet requirement,and both of them can be used in the dose calculation of adaptive radiotherapy.

Objective To explore novel methods for efficient respiratory viral infection of organoids by microinjection and polarity inversion techniques.Methods Lung tissue samples were obtained from 8-week-old male C57BL/6 mouse,and respiratory epithelial cells were extracted to establish a transwell organoid culture model.The green fluorescent protein(GFP)labeled influenza virus PR8(GFP-PR8)was quantitatively injected into organoids by improving the traditional microinjection platform,and morphologic changes in organoids and the immunofluorescence staining characteristics of tight junction proteins and microtubule proteins were observed.Polarity inversion apical-out(AO)was induced by suspension culture,and the morphological characteristics of polarity inversion was determined by HE staining.Normal and inverted organoids were infected with PR8,and the infection efficiency and expression differences of key pathway genes under different virus concentrations were observed.Results Ordinary organoids showed a significant increase in volume after microinjection.Following PR8 injection,the efficiency of infection was significantly higher in the apical region of organoids,accompanied by noticeable damage,as evidenced by significant down-regulation of tight junction proteins and microtubule protein expression.After suspension culture of the organoids,the polarity of ciliated cells gradually inverted outward over time,and the proportion of AO organoids stabilized on the 6th day.The efficiency of viral infection significantly increased in the inverted organoids,accompanied by significant cellular damage.After PR8 infection at 0.01 MOI,AO organoids showed significant changes in the inflammatory pathway and differentiation-related genes,with the opposite trend observed after higher concentration of PR8 infection.Conclusion Both polarity inversion and microinjection techniques significantly enhance the efficiency of influenza virus infection in organoids,thereby facilitating organoid widespread application in the field of respiratory tract infections.