International studies have established that electrons, X-rays, protons, and heavy ions can all be utilized in ultra-high dose-rate radiotherapy. Among these modalities, megavoltage X-ray ultra-high dose-rate radiotherapy holds particularly broad clinical promise. With its long-term expertise in high-intensity pulsed radiation sources, the Institute of Applied Electronics at the China Academy of Engineering Physics has pioneered global solutions for generating and measuring megavoltage X-rays ultra-high dose-rate radiotherapy, positioning China at the forefront of this field. Herein, we review the development history, current status, and future trends in ultra-high dose-rate X-ray generation, measurement, and protection. The insights provided aim to serve as a reliable reference for clinical and preclinical research, equipment development, and standardization, thereby enabling more precise and reliable megavoltage ultra-high dose-rate X-ray production and measurement. We hope this work will significantly support further research and clinical translation of ultra-high dose-rate radiotherapy technology.

Objective:To establish a rapid and precise dose measurement method with EBT4 film and ensure its measurement accuracy to be within the required range through strict operational procedures for the purpose of addressing the two essential issues of poor measurement accuracy and timeliness of EBT film under FLASH conditions.Methods:After storing under different humidity conditions for a certain period of time, the film was exposed to radiation for analyzing the influence of air humidity on the intrinsic performance of EBT film. By means of repeated scanning operations and the film angle rotation, the influences of repeated scanning and film placement angle were analuzed. Parabolic correction method was used to reduce the spatial position influence during the scanning process. By analying the relationship between net optical density (netOD) and absorbed dose through the comparison of three fitting method, the optimal fitting curve was selected. After irradiation of the same batch of films for 5 min and 24 h, the film doses were calibrated and then compared with ionization chamber-measured result. The rapid and precise film dosimetry method was used to measure both the percentage depth dose from X-rays at ultra-high dose rate and the dose distribution at a depth of 2 cm in water.Results:Air humidity had the greatest influence on the intrinsic performance of EBT film (approximately 20%). The average deviation of repeated scans is within 0.5%. The angle at which the film is placed significantly affected the readouts of the film with the maximum influence approximately 70%. The net optical density combined with polynomial fitting can control the fitting residuals of 1-16 Gy within 3%. The change rate of light channels at 5 min already mostly met the requirements of the rapid mode (< 0.5%). Compared with the measurement result obtained using the reference ionization chamber, the deviations of the 5 min or 24 h dose calibration curves were all within 2%.Conclusions:The EBT4 film can be employed as a precise dosimeter to quickly measure the FLASH radiation dose. Rapid and precise FLASH dose measurements can meet the stringent requirements of both preclinical and clinical FLASH research.

OBJECTIVE To investigate the current status of infection control departments setting,allocation of in-fection control professionals and their position competence in the secondary,tertiary traditional Chinese medi-cine institutions of Beijing.METHODS The questionnaire survey was conducted for all of the secondary and tertiary traditional Chinese medicine institutions in Beijing by Beijing Traditional Chinese Medicine Hospital Infection Man-agement Quality Control Center from Feb.17,2023 to Apr.11,2023.The content of the survey involved the in-formation of the hospitals,setting information of infection control departments and allocation of infection control professionals.RESULTS Totally 59 traditional Chines medicine medical institutions were involved in the survey,35(59.32％)were tertiary hospitals.The median of opened beds was 331(155,479)in the first quarter of 2023.The median of equipped infection control professionals was 4(3,5).The number of infection control professional e-quipped in 67.80％of the medical institutions conformed to requirements of"Notice regarding to further strength-en the management of infection control professionals allocation in medical institutions"released by The Joint Pre-vention and Control Mechanism of the State Council for the Response to the Novel Coronavirus Pneumonia Epi-demic in Aug.2021,with the ratio of infection control professionals to beds 1∶94.20.The principals in charge of the infection control department who had the qualifications for senior professional and technical position and en-gaged in infection control for more than 5 years accounted for 20.00％.Among the infection control professionals,nurses accounted for 49.17％,doctors 41.67％,other professionals 9.17％.CONCLUSIONS There is relatively adequate quantity of the infection control professional equipped in the secondary and tertia-ry medical institutions of Beijing,however,the principals in charge of the infection control department who had the qualifications for senior professional and technical position and engaged in infection control for more than 5 years are very scarce.It is necessary to further optimize the structure of the infection control professionals.

Objective To apply a multidimensional neonatal nutritional risk screening scale for hospitalized premature infants to explore its predictive value for extrauterine growth restriction(EUGR)at the time of discharge.Methods A total of 104 premature infants hospitalized in the Neonatal Department of the Second Affiliated Hospital of Kunming Medical University from January 2023 to September 2023 were selected as research subjects.Nutritional risk screening was conducted within 24 hours of admission and weekly thereafter using the multidimensional neonatal nutritional risk screening scale.Scoring was based on four dimensions(birth status,weight changes,nutritional intake methods,and disease diagnosis),with a total score of ≥ 8 indicating high risk;≥4 and＜8 indicating moderate risk;and＜4 indicating low risk.EUGR at the time of discharge was the primary clinical outcome indicator.Receiver operating characteristic(ROC)curves were constructed to explore the predictive value of neonatal nutritional risk screening for EUGR in premature infants.Results At discharge,40 premature infants(38.5％)experienced EUGR.The nutritional risk screening scores of the EUGR group on day 7 of hospitalization were higher than those of the non-EUGR group(P＜0.05).The rate of high nutritional risk on day 7 of hospitalization was highest(7.9％in the non-EUGR group,22％in the EUGR group,and 13.5％overall).On both day 1 and day 7 of hospitalization,the rate of high nutritional risk in the EUGR group was higher than that in the non-EUGR group(P＜0.05).There were significant differences in the nutritional risk screening scores on day 7,birth weight Z-scores,discharge corrected gestational age weight Z-scores,and serum albumin levels between the EUGR and non-EUGR groups(P＜0.05).ROC curves were plotted,yielding AUCs of 0.625(95％CI 0.514,0.736),0.652(95％CI 0.544,0.760),0.674(95％CI 0.561,0.786),and 0.641(95％CI 0.531,0.750),indicating certain predictive value.A combined predictive ROC model yielded an AUC of 0.786(95％CI 0.692,0.880)for EUGR,which was higher than the AUCs for individual indicators(P＜0.001).Conclusion The occurrence of EUGR is relatively common among hospitalized premature infants.The nutritional risk is highest during the first week of hospitalization.The multidimensional neonatal nutritional risk screening scale can dynamically assess nutritional risk during hospitalization and may serve as one of the early warning indicators for EUGR in premature infants.The predictive efficacy for EUGR is enhanced when combined with birth weight Z-scores,discharge weight Z-scores,and serum albumin,providing a basis for individualized nutritional management of premature infants.

Escherichia coli(E.coli)is a key pathogenic bacterium responsible for postpartum endo-metritis,with its colonization in the reproductive tract closely associated with endometrial damage and disruption of the ovarian cycle.This ultimately leads to infertility,causing significant economic losses to the dairy industry.Macrophages play a pivotal role in the inflammatory response.This study aims to investigate the mRNA expression profile of bovine bone marrow-derived macropha-ges following E.coli infection using RNA sequencing(RNA-seq)technology.Additionally,it seeks to identify the biological functions and signaling pathways of differentially expressed genes(DEGs)through Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses.The results demonstrated that E.coli infection induced differential expression of 4 522 genes,with 2 141 upregulated and 2 381 downregulated.These genes were primarily asso-ciated with inflammatory responses,where TLR2,TLR4,NLRP3,and PTGS2 played pivotal roles.PGD2 synthesis was mediated by TLR2,TLR4,and NLRP3.Transcriptome sequencing of bovine bone marrow-derived macrophages infected with E.coli and treated with a PGD2 inhibitor revealed a marked downregulation of TLR2 and TLR4 gene expression.qPCR validation results were highly consistent with the RNA-seq findings.This study elucidates the interactive regulatory roles of TLR2,TLR4,and NLRP3 in conjunction with PGD2,which collectively modulate bovine endome-tritis.These findings offer significant molecular insights that enhance our understanding of the pathological mechanisms underlying bovine endometritis,thereby informing its prevention and treatment strategies.

Escherichia coli(E.coli)is a key pathogenic bacterium responsible for postpartum endo-metritis,with its colonization in the reproductive tract closely associated with endometrial damage and disruption of the ovarian cycle.This ultimately leads to infertility,causing significant economic losses to the dairy industry.Macrophages play a pivotal role in the inflammatory response.This study aims to investigate the mRNA expression profile of bovine bone marrow-derived macropha-ges following E.coli infection using RNA sequencing(RNA-seq)technology.Additionally,it seeks to identify the biological functions and signaling pathways of differentially expressed genes(DEGs)through Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses.The results demonstrated that E.coli infection induced differential expression of 4 522 genes,with 2 141 upregulated and 2 381 downregulated.These genes were primarily asso-ciated with inflammatory responses,where TLR2,TLR4,NLRP3,and PTGS2 played pivotal roles.PGD2 synthesis was mediated by TLR2,TLR4,and NLRP3.Transcriptome sequencing of bovine bone marrow-derived macrophages infected with E.coli and treated with a PGD2 inhibitor revealed a marked downregulation of TLR2 and TLR4 gene expression.qPCR validation results were highly consistent with the RNA-seq findings.This study elucidates the interactive regulatory roles of TLR2,TLR4,and NLRP3 in conjunction with PGD2,which collectively modulate bovine endome-tritis.These findings offer significant molecular insights that enhance our understanding of the pathological mechanisms underlying bovine endometritis,thereby informing its prevention and treatment strategies.

International studies have established that electrons, X-rays, protons, and heavy ions can all be utilized in ultra-high dose-rate radiotherapy. Among these modalities, megavoltage X-ray ultra-high dose-rate radiotherapy holds particularly broad clinical promise. With its long-term expertise in high-intensity pulsed radiation sources, the Institute of Applied Electronics at the China Academy of Engineering Physics has pioneered global solutions for generating and measuring megavoltage X-rays ultra-high dose-rate radiotherapy, positioning China at the forefront of this field. Herein, we review the development history, current status, and future trends in ultra-high dose-rate X-ray generation, measurement, and protection. The insights provided aim to serve as a reliable reference for clinical and preclinical research, equipment development, and standardization, thereby enabling more precise and reliable megavoltage ultra-high dose-rate X-ray production and measurement. We hope this work will significantly support further research and clinical translation of ultra-high dose-rate radiotherapy technology.

Objective:To establish a rapid and precise dose measurement method with EBT4 film and ensure its measurement accuracy to be within the required range through strict operational procedures for the purpose of addressing the two essential issues of poor measurement accuracy and timeliness of EBT film under FLASH conditions.Methods:After storing under different humidity conditions for a certain period of time, the film was exposed to radiation for analyzing the influence of air humidity on the intrinsic performance of EBT film. By means of repeated scanning operations and the film angle rotation, the influences of repeated scanning and film placement angle were analuzed. Parabolic correction method was used to reduce the spatial position influence during the scanning process. By analying the relationship between net optical density (netOD) and absorbed dose through the comparison of three fitting method, the optimal fitting curve was selected. After irradiation of the same batch of films for 5 min and 24 h, the film doses were calibrated and then compared with ionization chamber-measured result. The rapid and precise film dosimetry method was used to measure both the percentage depth dose from X-rays at ultra-high dose rate and the dose distribution at a depth of 2 cm in water.Results:Air humidity had the greatest influence on the intrinsic performance of EBT film (approximately 20%). The average deviation of repeated scans is within 0.5%. The angle at which the film is placed significantly affected the readouts of the film with the maximum influence approximately 70%. The net optical density combined with polynomial fitting can control the fitting residuals of 1-16 Gy within 3%. The change rate of light channels at 5 min already mostly met the requirements of the rapid mode (< 0.5%). Compared with the measurement result obtained using the reference ionization chamber, the deviations of the 5 min or 24 h dose calibration curves were all within 2%.Conclusions:The EBT4 film can be employed as a precise dosimeter to quickly measure the FLASH radiation dose. Rapid and precise FLASH dose measurements can meet the stringent requirements of both preclinical and clinical FLASH research.

OBJECTIVE To investigate the current status of infection control departments setting,allocation of in-fection control professionals and their position competence in the secondary,tertiary traditional Chinese medi-cine institutions of Beijing.METHODS The questionnaire survey was conducted for all of the secondary and tertiary traditional Chinese medicine institutions in Beijing by Beijing Traditional Chinese Medicine Hospital Infection Man-agement Quality Control Center from Feb.17,2023 to Apr.11,2023.The content of the survey involved the in-formation of the hospitals,setting information of infection control departments and allocation of infection control professionals.RESULTS Totally 59 traditional Chines medicine medical institutions were involved in the survey,35(59.32％)were tertiary hospitals.The median of opened beds was 331(155,479)in the first quarter of 2023.The median of equipped infection control professionals was 4(3,5).The number of infection control professional e-quipped in 67.80％of the medical institutions conformed to requirements of"Notice regarding to further strength-en the management of infection control professionals allocation in medical institutions"released by The Joint Pre-vention and Control Mechanism of the State Council for the Response to the Novel Coronavirus Pneumonia Epi-demic in Aug.2021,with the ratio of infection control professionals to beds 1∶94.20.The principals in charge of the infection control department who had the qualifications for senior professional and technical position and en-gaged in infection control for more than 5 years accounted for 20.00％.Among the infection control professionals,nurses accounted for 49.17％,doctors 41.67％,other professionals 9.17％.CONCLUSIONS There is relatively adequate quantity of the infection control professional equipped in the secondary and tertia-ry medical institutions of Beijing,however,the principals in charge of the infection control department who had the qualifications for senior professional and technical position and engaged in infection control for more than 5 years are very scarce.It is necessary to further optimize the structure of the infection control professionals.

Objective:In order to explore the impact of corona virus disease 2019(COVID-19)on the hospitalization of children with bronchiolitis and to improve clinicians′ understanding of the characteristics of bronchiolitis during the COVID-19 epidemic.Methods:This was a multicenter clinical study, and the data have been collected from 23 children′s medical centers in China.All the clinical data were retrospectively collected from children with bronchiolitis who were hospitalized at each study center from January 1, 2019 to December 31, 2021.The results included gender, age at hospitalization, length of stay, respiratory syncytial virus(RSV) test results, severity rating, ICU treatment, and the total number of children hospitalized with respiratory tract infection during the same period.The clinical data of children with bronchiolitis in 2019 before COVID-19 epidemic and in 2020、2021 during COVID-19 epidemic were statistically analyzed and compared.Results:According to a summary of data provided by 23 children′s medical centers, there were 4 909 cases of bronchiolitis in 2019, 2 654 cases in 2020, and 3 500 cases in 2021.Compared with 2019, the number of bronchiolitis cases decreased by 45.94% in 2020 and 28.70% in 2021.In 2019, 2020 and 2021, there were no significant differences in gender ratio, age, and duration of hospitalization.Compared with 2019, the ratio of bronchiolitis to the total number of hospitalizations for respiratory tract infection decreased significantly in 2020 and 2021( χ2=12.762, P<0.05; χ2=84.845, P<0.05).The proportion of moderate to severe bronchiolitis cases in both 2020 and 2021 was lower than that in 2019, and the difference was statistically significant ( χ2=4.054, P<0.05; χ2=8.109, P<0.05).There was no statistically significant difference in the proportion of bronchiolitis cases requiring ICU treatment between 2019, 2020, and 2021 ( χ2=1.914, P>0.05).In 2019, a total of 52.60%(2 582/4 909) of children with bronchiolitis underwent RSV pathogen testing, and among them, there were 708 cases with RSV positive, accounting for 28.00%.In 2020, 54.14%(1 437/2 654) of children with bronchiolitis underwent RSV pathogen testing, and there were 403 cases with RSV positive, accounting for 28.04%.In 2021, 66.80%(2 238/3 500) of children with bronchiolitis underwent RSV pathogen testing, and there were 935 cases with RSV positive, accounting for 41.78%.Compared with 2019 and 2020, the RSV positive rate in 2021 showed a significant increase( χ2=99.673, P<0.05; χ2=71.292, P<0.05). Conclusion:During the COVID-19 epidemic, the implementation of epidemic prevention and control measures reduced the hospitalization rate and severity of bronchiolitis, but did not reduce the positive rate of RSV detection.