OBJECTIVES: As early as the Apollo 11 mission, astronauts experienced ocular, skin, and upper airway irritation after lunar dust (LD) was brought into the return cabin, drawing attention to its potential biological toxicity. However, the biological effects of LD exposure through the digestive system remain poorly understood. This study aimed to evaluate the impact of digestive exposure to lunar dust simulant (LDS) on gut microbiota and on the intestine, liver, kidney, lung, and bone in mice. METHODS: Eight-week-old female C57BL/6J mice were used. LDS was used as a substitute for lunar dust, and Shaanxi loess was used as Earth dust (ED). Mice were randomly divided into a phosphate buffered saline (PBS) group, an ED group (500 mg/kg), and a LDS group (500 mg/kg), with assessments at days 7, 14, and 28. Mice were gavaged once every 3 days, with body weight recorded before each gavage. At sacrifice, fecal samples were analyzed by 16S ribosomal RNA (rRNA) sequencing; inflammatory cytokine expression [interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α)] in intestinal, liver, and lung tissues was measured by real-time reverse transcription PCR (real-time RT-PCR); hematoxylin and eosin (HE) staining was performed on lung, liver, and intestinal tissues; Periodic acid-Schiff (PAS) staining was used to assess the integrity of the intestinal mucus barrier, and immunohistochemical staining was performed to evaluate the expression of mucin-2 (MUC2). Serum biochemical tests assessed hepatic and renal function. Femoral bone mass was analyzed by micro-computed tomography (micro-CT); osteoblasts and osteoclasts were assessed by osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP) staining. Bone marrow immune cell subsets were analyzed by flow cytometry. RESULTS: At day 10, weight gain was slowed in ED and LDS groups. At days 22 and 28, body weight in both ED and LDS groups was significantly lower than controls (both P<0.05). LDS exposure increased microbial species richness and diversity at day 7. Compared with the PBS and ED groups, mice in the LDS group showed increased relative abundance of Deferribacterota, Desulfobacterota, and Campylobacterota, and decreased Firmicutes, with increased Helicobacter typhlonius and reduced Lactobacillus johnsonii and Lactobacillusmurinus. HE and PAS staining of the colon showed that mucosal structural disruption and goblet cell loss were more severe in the LDS group. In addition, immunohistochemistry revealed a significant downregulation of MUC2 expression in this group (P<0.05). No obvious pathological alterations were observed in liver HE staining among the 3 groups, and none of the groups exhibited notable hepatic or renal dysfunction. HE staining of the lungs in the ED and LDS groups showed increased perivascular inflammatory cell infiltration (both P<0.05). CONCLUSIONS LDS exposure via the digestive route induces gut dysbiosis, intestinal barrier disruption, pulmonary inflammation, bone loss, and bone marrow immune imbalance. These findings indicate that LD exposure poses potential health risks during future lunar missions. Targeted restoration of beneficial gut microbiota may represent a promising strategy to mitigate LD-related health hazards.
Animals ; Dust ; Mice ; Mice, Inbred C57BL ; Dysbiosis/etiology* ; Female ; Gastrointestinal Microbiome/drug effects* ; Moon ; Liver/metabolism* ; Digestive System/microbiology* ; Lung/metabolism* ; Kidney

OBJECTIVES: Due to prolonged exposure to cosmic radiation and meteorite impacts, lunar surface dust forms nanoscale angular particles with strong electrostatic adsorption properties. These dust particles pose potential inhalation risks, yet their pulmonary toxicological mechanisms remain unclear. Given the need for dust exposure protection in future lunar base construction and resource development, this study established an acute exposure model using lunar soil simulant (LSS) and used Earth soil (ES; Loess from Shaanxi, China) as a comparison to investigate lung injury mechanisms. METHODS: C57BL/6 mice were randomly assigned to 3 groups: Phosphate buffered saline (PBS), LSS, and ES, with 5 to 7 mice per group. Mice in the LSS and ES groups received a single intratracheal instillation to induce acute inhalation exposure. Body weight was monitored for 28 days. Mice were euthanized at days 3, 7, 14, and 28 post-exposure, and peripheral blood, bronchoalveolar lavage fluid (BALF), and lung tissues were collected. Immune cell subsets in BALF were analyzed using flow cytometry. Hematoxylin-eosin (HE) staining assessed lung structure and inflammation; periodic acid-Schiff (PAS) staining evaluated airway mucus secretion; Masson staining examined collagen deposition. Real-time reverse transcription PCR (real-time RT-PCR) was used to measure the mRNA expression of inflammatory cytokines (IL-1β, IL-6, and TNF-α) and epithelial barrier genes (Occludin, Cadherin-1, and Zo-1). Lung tissues at day 7 were subjected to transcriptomic sequencing, followed by immune infiltration and pathway enrichment analyses to determine immunoregulatory mechanisms. RESULTS: Body weight in the ES group progressively declined after day 18 (all P<0.05), while the LSS group showed no significant changes compared with the control group. HE staining showed both LSS and ES induced inflammatory cell infiltration around airways and vasculature, which persisted for 28 days but gradually lessened over time. PAS staining revealed marked mucus hypersecretion in the LSS group at day 3, followed by gradual recovery; no significant mucus changes were observed in the ES group. Masson staining indicated no obvious pulmonary fibrosis in either group within 28 days. Real-time RT-PCR demonstrated significant upregulation of IL-1β and TNF-α in both LSS and ES groups, peaking on day 7, accompanied by downregulation of epithelial barrier genes (Occludin, Cadherin-1, and Zo-1)(all P<0.05). Transcriptomic analysis showed that both LSS and ES activated chemokine-related pathways and enriched leukocyte migration and neutrophil recruitment pathways. Further validation revealed upregulation of CXCL2 and MMP12 in the LSS group, whereas CXCL3 and MMP12 were predominantly elevated in the ES group. CONCLUSIONS Both LSS and ES can induce sustained lung injury and neutrophil infiltration in mice, though the underlying molecular mechanisms differ. Compared with ES, exposure to LSS additionally triggers a transient eosinophilic response, suggesting that lunar dust particles possess stronger immunostimulatory potential and higher biological toxicity.
Animals ; Mice ; Mice, Inbred C57BL ; Soil ; Lung Injury/etiology* ; Dust ; Bronchoalveolar Lavage Fluid ; Moon ; Lung/pathology* ; Inhalation Exposure/adverse effects* ; Male

Objective To study the plasma metabolomics of mice poisoned by different dosage of the combination of diazepam and ethanol,and to reveal the toxicological mechanisms of combined poisoning of diazepam and ethanol.Methods Female Kunming mice were randomly divided into blank group,single and combined poisoning group(n=6),Based on the LD50 of diazepam co-administered with graded ethanol doses,mice in the single-drug and combined groups received oral gavage at 1/2,1,and 2 × LD50.Retro-orbital blood samples(～500 μL)were collected within 24 hours post-administration and analyzed by UPLC-QE-MS technology.Principal component analysis and orthogonal partial least squares discriminant analysis were used to identify differential metabolites and associated metabolic pathways.Results A total of 387 differential metabolites were identified in the combined poisoning group of diazepam and ethanol implicating the key pathways including tryptophan metabolism,phenylalanine metabolism,arginine and proline metabolism,Glycerophospholipid metabolism,phenylalanine,tyrosine and tryptophan biosynthesis.Conclusion Combined diazepam and ethanol poisoning exerts significant systemic effects by disrupting neurotransmitters conduction,exacerbating oxidative stress response and dysregulating energy metabolism.

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.

The prevalence of suicidal ideation (SI) and suicide behavior (SB) has gradually risen among adolescents with major depressive disorders in recent years, yet the underlying neurological mechanisms remain unknown. With the advancement of neuroimaging technology, multimodal magnetic resonance imaging (MRI) methods show fundamental value in detecting structural and functional brain abnormalities associated with these conditions. Preliminary studies have revealed alterations in key brain regions, such as the prefrontal cortex, amygdala, and anterior cingulate cortex, in adolescents with major depressive disorders. These findings provide critical insights into the neuropathological basis and underlying mechanisms of SI and SB in adolescent major depressive disorders. This review summarizes recent advances in brain structure and function in adolescents with major depressive disorder who exhibit SI and/or SB using diverse MRI techniques. This paper will provide new insights for the investigation of the neurobiological mechanisms underlying suicidality in adolescents with major depressive disorder, and provide objective neuroimaging evidence for the early identification and individualized intervention for at-risk adolescents.

Objective To study the plasma metabolomics of mice poisoned by different dosage of the combination of diazepam and ethanol,and to reveal the toxicological mechanisms of combined poisoning of diazepam and ethanol.Methods Female Kunming mice were randomly divided into blank group,single and combined poisoning group(n=6),Based on the LD50 of diazepam co-administered with graded ethanol doses,mice in the single-drug and combined groups received oral gavage at 1/2,1,and 2 × LD50.Retro-orbital blood samples(～500 μL)were collected within 24 hours post-administration and analyzed by UPLC-QE-MS technology.Principal component analysis and orthogonal partial least squares discriminant analysis were used to identify differential metabolites and associated metabolic pathways.Results A total of 387 differential metabolites were identified in the combined poisoning group of diazepam and ethanol implicating the key pathways including tryptophan metabolism,phenylalanine metabolism,arginine and proline metabolism,Glycerophospholipid metabolism,phenylalanine,tyrosine and tryptophan biosynthesis.Conclusion Combined diazepam and ethanol poisoning exerts significant systemic effects by disrupting neurotransmitters conduction,exacerbating oxidative stress response and dysregulating energy metabolism.

OBJECTIVE To investigate the current status of bloodborne occupational exposures among healthcare workers in a three-A specialized hospital of Shanghai so as to provide bases for formulating prevention measures for occupational exposures.METHODS A questionnaires titled'Survey of bloodborne occupational exposures among healthcare workers'were clinically distributed to Eye &ENT Hospital of Fudan University through'Wenjuanxing platform'from Feb.2024 to Apr.2024.The content of the questionnaire included four parts:the baseline data questionnaire,incidence of occupational exposures,awareness of knowledge about occupational exposures,and preventive behaviors regarding occupational exposures.RESULTS A total of 995 valid questionnaires were collect-ed in the survey,the result of the survey showed that the incidence of bloodborne occupational exposures was 10.65％.The clinicians and doctors engaging in advanced studies were at high risk of the occupational exposures especially when they were busy with work.The result of the survey indicated that the rate of missing report was 71.33％,the implementation rate of monitoring was only 48.11％after the exposures,of which the major cau-ses included the health care workers'insufficient attention to the exposure events,flaws in prevention and control of occupational exposures and some personnels'poor awareness of reporting process and requirements for monito-ring.Although the awareness rate of emergency processing exceeded 90％,the awareness rate of the knowledge a-bout prophylactic use of antibiotics and prevention of needlestick injuries,and the preparations before diagnosis and treatment,standardized operations and use of protective articles still needed to be improved.CONCLUSIONS The survey reveals that the health care workers pay less attention to the risk of infections,and the prevention of occupational exposure needs to be improved.It is of great importance to raise the awareness of prevention and en-hance the systematic training for occupational exposure.

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.