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 novel magnetic composite nanoparticle with excellent targeting and biocompatibility and verify synergistic magnetic hyperthermia/radiotherapy efficacy in HeLa cells.Methods:Bovine serum albumin(BSA)was used to modify ferroferric oxide(Fe 3O 4)nanoparticles, and then L-selenocystine and folic acid(FA)were coupled on the surface of BSA by carbodiimide method to synthesize magnetic composite nanoparticles Fe 3O 4@BSA@SeCyc2@FA.The as-prepared nanoparticles were characterized to determine the structure, composition, and properties of the nanoparticles to support their biological applications.By evaluating the magnetothermal properties of the as-prepared nanoparticles, analyzing the internalization effect of HeLa cells on the particles and using CellTiter and reactive oxygen species(ROS)kits to detect the cell viability and ROS production of different experimental groups, respectively, the killing and inhibiting effects on HeLa cells were evaluated when hyperthermia was combined with radiotherapy. Results:The average particle size of the Fe 3O 4@BSA@SeCyc2@FA nanoparticles was(19.31 ± 4.84)nm, and the zeta potential was -25.4 mV(pH=7), which indicated that the as-prepared nanoparticles maintained acceptable dispersion and stability for biological experiments.By BSA and FA characteristic absorption peaks combined with the measured content of Se(10.89 μM), L-selenocystine and FA were successfully modified on the surface of the composite nanoparticles.The saturation magnetization value of the Fe 3O 4@BSA@SeCyc2@FA nanoparticles was 47.2 emu/g.The as-prepared nanoparticles maintained the specific absorption rate(SAR)value of 125.4 W/g at the alternating magnetic field of 518 kHz/16 kAm -1, indicating excellent heat generation efficiency(the temperature level ΔT=7 ℃ within 15 min).No significant toxicity was found for HUVEC cells even within the concentration range from 0 to 200 μg/ml and inhibition of cell viability of the HeLa was shown.When magnetic hyperthermia combined with high-energy X-ray, the cell viability of the HeLa decreased significantly to 54.7%, and the intracellular ROS production increased by 108.2% compared with the control group, which showed that the as-prepared nanoparticles significantly enhanced the radiosensitivity of HeLa cells, and the synergistic effect of magnetic hyperthermia combined with radiotherapy was more effective in inhibiting and killing them. Conclusions:The as-prepared nanoparticles show great promise for use as a multifunctional nanoplatform for the synergistic magnetic hyperthermia/radiotherapy to overcome the limitations of monotherapy for cancer treatment.

Objective:To study the applicability of conventional detection method, gamma spectrometry and radiochemical analysis, for the determination of 137Cs activity concentratons in food samples and to compare the difference of such two methods for this purpose. Methods:By using both γ spectrometry and radiochemical analysis, the activity concentrations of 137Cs in different types of food were determined, to compare the required sample amounts, the sample pretreatment and preparation processes and the lower detection limits.With meat samples as a case study, the two method were compared for assessing the activity concentrations of 137Cs in meat samples and evaluating the uncertainties. Results:The deviation of measurement result obtained in meat by using gamma spectrometry and ammonium phosphomolybdate-β counting method is consistent, with relative extended uncertainties of 18.0% and 8.0%, respectively. The pretreatment process for γ spectrometry is characterized by its simplicity, but large sample amount required and time-comsuming process, while the ammonium phosphomolybdate method requires a small amount of sample but in need of separation and purification process.The detection limits of the two methods are 10.6 mBq/kg (sample mass 11.7 kg) and 5.1 mBq/kg (sample sample 2.1 kg ), respectively.Conclusions:The results of two methods for determinationf of the low activity concentrations of 137Cs in food samples are consistent. Therefore, when monitoring low activity concentrations of 137Cs in food samples, the appropriate detection method can be selected based on the specific objective and requirements of the monitoring study.

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 study the improvement effects of ica riin（ICA）on cognitive function in schizophrenia model rats and its mechanism. METHODS ：SD rats were divided into blank control group ，model group ，ICA low-dose ，medium-dose and high-dose groups （15，30，60 mg/kg）. Except for blank control group ，other groups were given N-methyl-D-aspartate receptor antagonist MK- 801（0.2 mg/kg）intraperitoneally to induce schizophrenia rats models ，once a day ，for consecutive 14 days. After modeling，ICA groups were intragastrically administered with the corresponding drugs ，while blank control group and model group were intragastrically administered with the same volume of water ，once a day ，for consecutive 7 days. The behavioral com changes of rats were detected by Morris water maze test ，open field test ， forced swimming test and Y maze test pathological changes of hippocampus were observed by Nissl staining；the levels of cholinergic indexes [acetylcholine （Ach），choline acetyltransferase （ChAT） and acetylcholinesterase （AchE）] in cerebral tissues were detected by ELISA. The expression of BDNF ，ERK and CREB mRNA in cerebral tissue were detected by RT-PCR ；expression or phosphorylation level of BDNF ，ERK，CREB protein ，apoptosis related proteins （Bcl-2，Bax and Caspase- 3）were detected by Western blot. RESULTS ：Compared with blank control group ，escape latency ，distance at T 1-T3， cumulative immobility time and the expression of Caspase- 3 protein in cerebral tissues were significantly increased in model group （P＜0.05）；the times of crossing platform ，alternation rate ，the number of Nissl staining positive neurons in hippocampus tissues ， the levels of Ach and ChAT in cerebral tissues ，Bcl-2/Bax ratio ，mRNA and protein expression of BDNF ，mRNA expression of ERK and CREB ，the phosphorylation of ERK 1/2 and CREB were significantly decreased （P＜0.05）.Compared with model group ， escape latency ，distance at T 1-T3，cumulative immobility time ，the number of Nissl staining positive neurons ，AchE level in cerebral tissues and relative expression of Caspase- 3 protein were significantly decreased in ICA high-dose group （P＜0.05）；the times of crossing platform ，alternation rate ，levels of Ach and ChAT in cerebral tissues ，Bcl-2/Bax ratio ，mRNA and protein expression of BDNF ，mRNA expression of ERK and CREB ，the phosphorylation of ERK 1/2 and CREB were increased significantly（P＜0.05）. Above indexes in ICA low-dose and medium-dose groups were partially improved significantly than model group（P＜0.05）. CONCLUSIONS ：ICA can improve cognitive function in schizophrenia model rats.Its mechanism may be related to regulating cholinergic system ，inhibiting neuronal apoptosis ，and promoting the expression of BDNF/ERK/CREB signaling pathway.

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 study the genotype distribution of drug-related gene polymorphism of methotrexate (MTX) and leflunomide (LEF) in patients with rheumatoid arthritis (RA).Methods:The genotyping results of RA patients' MTX and LEF related genes(MTHFR677C/T, MTHFR1298A/C, ABCB13435T/C, DHODH19C/A and CYP1A2734C/A) detected in Shanghai Guanghua Hospital from December 2018 to May2019 and drug-related adverse effect were statisticallyanalyzed. The independence of allele distribution was tested by Hardy-Weinberg test. Counting data of genotypes and allele frequencies among the groups were analyzed by the chi-square test. Measurement data were showed as Mean±SD deviation. The network between incidence of adverse events and genotypes of patients was analyzed by cytoscape software. Results:Genotype distribution in 151 patients was consistent with Hardy-Weinberg genetic balance ( P>0.05), and genotype and allele distribution of each gene showed no statistical difference in gender ( P>0.05). The results showed that the most common genotype in RA were that genotypes of the good response with moderate resistance to MTX (MTHFR677CC/MTHFR1298AA/ABCB13435CT) (16 cases, 13.5%) and the good response with moderate side effect risk to LEF(DHODH19CC/CYP1A2734AC) (25 cases, 28.4%). According to the distribution frequency of alleles, the incidence of high side effects caused by MTX combined with LEF was predicted to be 2.9%, which was close to 1.8% of the actual genotypes of patients. The types and proportion of clinical adverse reactions in patients were retrospectively analyzed and the correlation network analysis was conducted with the genotype analysis results. It was found that the incidence rates of adverse reactions were liver injury (35.4%, 35/99), leukopenia (14.1%, 14/99), thrombocytopenia (2.0%, 2/99), and skin rash (1.0%, 1/99) from the top to the bottom. The top two genotypes that were related to the occurence of adverse events were MTHFR677CT/MTHFR1298AA/ABCB13435CT and DHODH19CA/CYP1A2734AC, respectively, which verified the consistency between drug-related genotype and clinical manifestations in RA patients. Conclusion:Our results suggested that genotype in RA patients is closely related to drug efficacy and adverse events. 2.9% of RA patients need to stop taking MTX and LEF due to high MTX resistance and poor MTX response and increased toxicity when combined with LEF, in which the proportion of liver injury is the highest.

Objective: To evaluate the effect of Notch-Hes1 signaling blockade by a γ-secretase inhibitor on the expression of γδT17 cells in a mouse model of psoriasis-like skin inflammation. Methods: Forty-five healthy specific pathogen-free (SPF) male BALB/c mice were randomly divided into control group, model group and intervention group by simple random sampling. The model group and intervention group were both topically treated with imiquimod 5% cream (62.5 mg once a day) on the shaved back, the intervention group were then intraperitoneally injected with the γ-secretase inhibitor DAPT (10 mg/kg once a day) immediately after topical application of imiquimod, and the control group were topically treated with equivalent amount of vaseline once a day. After 6-day treatment, psoriasis area and severity index (PASI) was used to evaluate changes of skin lesions. On day 7, blood samples were obtained from all the mice through heart puncture after anesthetization, and spleen and skin tissues were acquired to prepare single cell suspension. Spleen index was compared among the 3 groups. Skin tissues on the mouse back were resected and subjected to hematoxylin-eosin staining to observe histopathological changes. Flow cytometry was performed to determine the percentage of γδT17 cells in the spleen and skin tissues, real-time reverse transcription (RT) -PCR to measure the mRNA expression of Hes1 in single cell suspension of the spleen, and enzyme-linked immunosorbent assay (ELISA) to determine the serum level of interleukin (IL) -17A. Statistical analysis was carried out by using one-way analysis of variance and repeated measures analysis of variance for comparison of indices among groups, and Pearson correlation analysis for evaluating the correlation between different indices. Results: Twenty-four hours after the final treatment, the intervention group showed milder psoriasis-like skin inflammation, lower PASI score, and milder degree of epidermal thickening and dermal inflammatory cell infiltration compared with the model group. The model group showed significantly increased spleen index (12.534 ± 1.636) , proportions of γδT17 cells in the spleen (24.659% ± 4.603%) and skin tissues (22.127% ± 5.670%) , mRNA expression of Hes1 in the spleen (4.867 ± 0.543) , and serum level of IL-17A ([22.478 ± 2.776] ng/L) compared with the control group (all P < 0.01) . However, the above indices were significantly lower in the intervention group (9.449 ± 1.040, 14.966% ± 5.770%, 13.631% ± 5.946%, 2.541 ± 0.347, [18.639 ± 1.816] ng/L) than in the model group (all P < 0.01) . In the model group and intervention group, there were positive correlations between the proportions of γδT17 cells in the spleen and serum levels of IL-17A (r = 0.56, 0.53 respectively, both P < 0.05) , between the proportions of γδT17 cells in skin lesions and PASI scores (r = 0.56, 0.52 respectively, both P < 0.05) , as well as between the mRNA expression of Hes1 in the spleen and the proportions of γδT17 cells (r = 0.61, 0.58 respectively, both P < 0.05) or serum levels of IL-17A (r = 0.60, 0.54 respectively, both P < 0.05) . Conclusion Notch-Hes1 signaling blockade by γ-secretase inhibitor can markedly inhibit the expression of γδT17 cells, and effectively alleviate the severity of psoriasis-like skin inflammation in mouse models.

Objective: To establish the HPLC fingerprints of compound Yinchen granules. Methods: The column was Agilent SB-C18(250 mm×4. 6 mm, 5 μm) and the mobile phase was acetonitrile (A)-0. 2% phosphoric acid solution (B) with gradient elution at a flow rate of 1. 0 ml·min-1. The column temperature was 25℃. The detection wavelength switching technology was used in 180-mi-nute elution time. Results: The HPLC fingerprints of compound Yinchen granules were established. Twenty-two common peaks were confirmed, of which five peaks were identified and 18 peaks were assigned to each crude drug. The overall similarity of the fingerprints of 10 batches of samples was 0. 9 or more when compared with the control map. Conclusion: The fingerprints of compound Yinchen granules can provide reference for the overall quality control of compound Yinchen granules.