Objective To evaluate the influence of the wearing position of dosimeters outside lead aprons on effective dose estimation for interventional radiology workers, analyze the differences between single and double dosimeter methods in effective dose estimation, and provide a reference for the personal dose monitoring of interventional radiology workers. Methods This study employed a combined approach of on-site monitoring and Monte Carlo simulation to evaluate the impact of the wearing position of dosimeters outside lead aprons on effective dose estimation, as well as the differences between effective doses measured using single and double dosimeters. Interventional radiology workers wore dosimeters at three positions: the neck outside the lead collar, the left chest outside the lead apron, and inside the lead apron. Effective doses were estimated using the single and double dosimeter methods specified in GBZ 128-2019 Specifications for individual monitoring of occupational external exposure, and the impact of different wearing positions on the estimation results was compared. Geant4 Monte Carlo simulations were used to model dose distributions at the neck outside the lead collar and at the left chest outside the lead apron for operators performing cardiovascular interventions under tube voltages of 70, 80, 90, and 100 kVp and exposure angles of posteroanterior (PA), anteroposterior (AP), and left anterior oblique 45° (LAO45°) positions. The study assessed the impact of dosimeter wearing position on effective dose estimation. Results Monte Carlo simulations demonstrated that neck doses consistently exceeded left chest doses across different tube voltages and exposure angles, with neck-to-chest dose ratios of 0.80-0.90. Under identical tube voltage conditions, AP showed the highest doses, followed by LAO45°, and PA demonstrated the lowest doses. The single and double dosimeter methods exhibited consistent patterns in effective dose estimation. Single dosimeter method generally yielded higher effective doses with relative deviations of 9.9% to 83%, though these deviations decreased under high tube voltages. Field monitoring data indicated that most interventional radiology workers maintained relative deviations between single and double dosimeter calculations below 6%, with neck-to-chest dose ratios of 0.95-1.1. The estimation patterns remained consistent across both methods, though single dosimeter method showed slightly higher results. Conclusion Under PA, AP, or LAO45°, the doses at the neck consistently exceeded those at the left chest. Therefore, when wearing lead protective equipment, the dosimeter should be properly positioned at the neck outside the lead collar to accurately reflect the radiation doses of surgeons. Some interventional radiology workers improperly positioned the dosimeter (intended at the neck outside the lead collar) at the left chest outside the lead apron, and this may result in an underestimation of the effective dose.

OBJECTIVES: To propose a single repetition time (TR) quantitative magnetic susceptibility imaging method for the lumbar spine using bipolar readout gradient, and compare the quantitative magnetic susceptibility measurement using single TR and dual TR methods for the lumbar spine with different bone densities. METHODS: A translation correction method was proposed to correct spatial misalignment along the frequency encoding direction between positive and negative gradient readout images, and the phase difference between the images was eliminated using a phase correction method. The data of lumbar vertebrae L1-L5 were collected using single TR and dual TR methods from 6 normal individuals, 2 patients with osteopenia, and 2 patients with osteoporosis. The magnetic susceptibility map was reconstructed, the quantitative results of single TR before and after correction were compared with those of the dual TR method. RESULTS: The linear regression result of the lumbar spine magnetic susceptibility values obtained by the single TR method before calibration and the dual TR method is Y=0.64*X-11.61. The linear regression result of the lumbar spine magnetic susceptibility values corrected by the single TR method and the dual TR method is Y=1.03*X+0.25. The results of the corrected single TR method were highly consistent with those of the dual TR method, and the calibrated single TR method could effectively distinguish osteopenia and osteoporosis patients from normal individuals. CONCLUSIONS The calibrated single TR bipolar readout gradient method can generate artifact-free lumbar spine quantitative magnetic susceptibility distribution maps and reduce data acquisition time by 50%.
Humans ; Lumbar Vertebrae/pathology* ; Magnetic Resonance Imaging/methods* ; Female ; Middle Aged ; Male ; Osteoporosis/diagnosis* ; Adult ; Bone Density ; Aged ; Bone Diseases, Metabolic/diagnosis*

OBJECTIVE: To compare the efficacy and safety of intravenous colistin sulfate combined with nebulized inhalation versus intravenous monotherapy for pulmonary infections caused by carbapenem-resistant organism (CRO). METHODS: A multicenter retrospective cohort study was conducted. Clinical data were collected from patients admitted to the intensive care unit (ICU) of 10 tertiary class-A hospitals in Henan Province between July 2021 and May 2023, who received colistin sulfate for CRO pulmonary infections. Data included baseline characteristics, inflammatory markers [white blood cell count (WBC), neutrophil count (NEU), procalcitonin (PCT), C-reactive protein (CRP)], renal function indicators [serum creatinine (SCr), blood urea nitrogen (BUN)], life support measures, anti-infection regimens, clinical efficacy, microbiological clearance rate, and prognostic outcomes. Patients were divided into two groups: intravenous group (colistin sulfate monotherapy via intravenous infusion) and combination group ((intravenous infusion combined with nebulized inhalation of colistin sulfate). Changes in parameters before and after treatment were analyzed. RESULTS: A total of 137 patients with CRO pulmonary infections were enrolled, including 89 in the intravenous group and 48 in the combination group. Baseline characteristics, life support measures, daily colistin dose, and combination regimens (most commonly colistin sulfate plus carbapenems in both groups) showed no significant differences between two groups. The combination group exhibited higher clinical efficacy [77.1% (37/48) vs. 59.6% (52/89)] and microbiological clearance rate [60.4% (29/48) vs. 39.3% (35/89)], both P < 0.05. Pre-treatment inflammatory and renal parameters showed no significant differences between two groups. Post-treatment, the combination group showed significantly lower WBC and CRP [WBC (×10⁹/L): 8.2±0.5 vs. 10.9±0.6, CRP (mg/L): 14.0 (5.7, 26.6) vs. 52.1 (24.4, 109.6), both P < 0.05], whereas NEU, PCT, SCr, and BUN levels showed no significant between two groups. ICU length of stay was shorter in the combination group [days: 16 (10, 25) vs. 21 (14, 29), P < 0.05], although mechanical ventilation duration and total hospitalization showed no significant differences between two groups. CONCLUSIONS Intravenous colistin sulfate combined with nebulized inhalation improved clinical efficacy and microbiological clearance in CRO pulmonary infections with an acceptable safety profile.
Humans ; Colistin/therapeutic use* ; Retrospective Studies ; Administration, Inhalation ; Anti-Bacterial Agents/therapeutic use* ; Carbapenems/pharmacology* ; Male ; Female ; Middle Aged ; Gram-Negative Bacteria/drug effects* ; Aged ; Treatment Outcome ; Respiratory Tract Infections/drug therapy*

Twelve derivatives of asiatic acid were synthesized through acylation, alkylation, oxidative dehydrogenation and other reactions using asiatic acid from usoxane-type pentacyclic triterpenoids as the parent compound. Their structures were confirmed by 1H NMR and 13C NMR, and determined to be novel compounds never reported in literature. Through the MTT method, high-expression human cancer cells (A549 and SGC-7901) were selected for a preliminary in vitro anti-tumor activity study on these compounds. Among them, the IC50 of compound I1 were 11.39 and 9.08 μmol/L respectively, and those of compound I2 were 12.64 and 9.15 μmol/L respectively, which were close to those of sorafenib, a common drug for clinical use. The experimental results show that the synthesized asiatic acid derivatives have certain anti-proliferative effects on the two types of human cancer cells, A549 and SGC-7901, significantly higher than those of asiatic acid. Compounds I1 and I2 show quite strong anti-proliferative effects on human cancer cells A549 and SGC-7901.

Objective To preliminarily design a wide-energy-spectrum CR-39 solid-state nuclear track individual neutron dosimeter with different energy sections. Methods The thickness of the converter was optimized using the Monte Carlo SRIM program to broaden the energy range of the dosimeter. The self-made wide-energy-spectrum CR-39 individual neutron dosimeter was calibrated using ²⁴¹Am-Be, ²⁵²Cf, and thermal neutron sources to evaluate its dosimetric performance, including linearity, energy response, and neutron energy resolution. Results The linear correlation coefficient of the measurement system exceeded 0.98. The relative deviations of the energy response were 35.0% for blank section and 42.0% for polyethylene section, falling within the range of −50% to + 100% and meeting the monitoring requirements. The detection sensitivity for thermal neutron dose was 67 137.2 tr·cm⁻²·mSv⁻¹, and the detection sensitivity for thermal neutron fluence was 0.98 × 10⁻³ tr·n⁻¹, demonstrating good thermal neutron detection capability. Conclusion The self-made wide-energy-spectrum CR-39 individual neutron dosimeter fundamentally meets the requirements for individual neutron dose monitoring and is suitable for individual neutron dose monitoring in the energy range of thermal neutrons (up to approximately 15 MeV).

Objective To identify the reasons why the monitored personal doses of radiation worker A in an institution exceeded the investigation level in 2023 and 2024, and remind workers to wear personal dosimeters in a standardized manner in scenarios such as work and business trips to ensure the authenticity and reliability of the monitoring data. Methods A thermoluminescence measurement system was used to read the personal dosimeters worn by radiation workers. Investigations were carried out on personnel whose doses exceeded the investigation level described in the “Specifications for individual monitoring of occupational external exposure” (GBZ 128—2019). The reasons for doses exceeding the investigation level were analyzed using additional dosimeters and conducting on-site experiments. Results In 2023 and 2024, radiation worker A recorded a total of 5 personal dose equivalents exceeding the investigation level (1.23 mSv) over a total of 8 monitoring cycles (each lasting 90 days). Following one cycle where the dose exceeded the investigation level, two additional dosimeters (each for a 30-day cycle) were issued to worker A, revealing readings below the investigation level for the 30-day monitoring cycle (0.41 mSv). The reading for the dosimeter was 2-3 μSv per time when passing through an X-ray security scanner, and approximately 2.10 mSv per time when passing through a computed tomography security scanner. Conclusion Within a 90-day monitoring cycle, a single exposure of a personal dosimeter to a computed tomography security scanner can result in a dose exceeding the investigation level. Radiation workers should avoid placing dosimeters in backpacks or suitcases that pass through computed tomography security scanners during business trips, so as to reduce the impact of security scanner irradiation on personal dose monitoring.

Objective:To retrospectively analyze the treatment status of tyrosine kinase inhibitors (TKI) in newly diagnosed patients with chronic myeloid leukemia (CML) in China.Methods:Data of chronic phase (CP) and accelerated phase (AP) CML patients diagnosed from January 2006 to December 2022 from 77 centers, ≥18 years old, and receiving initial imatinib, nilotinib, dasatinib or flumatinib-therapy within 6 months after diagnosis in China with complete data were retrospectively interrogated. The choice of initial TKI, current TKI medications, treatment switch and reasons, treatment responses and outcomes as well as the variables associated with them were analyzed.Results:6 893 patients in CP ( n=6 453, 93.6%) or AP ( n=440, 6.4%) receiving initial imatinib ( n=4 906, 71.2%), nilotinib ( n=1 157, 16.8%), dasatinib ( n=298, 4.3%) or flumatinib ( n=532, 7.2%) -therapy. With the median follow-up of 43 ( IQR 22-75) months, 1 581 (22.9%) patients switched TKI due to resistance ( n=1 055, 15.3%), intolerance ( n=248, 3.6%), pursuit of better efficacy ( n=168, 2.4%), economic or other reasons ( n=110, 1.6%). The frequency of switching TKI in AP patients was significantly-higher than that in CP patients (44.1% vs 21.5%, P<0.001), and more AP patients switched TKI due to resistance than CP patients (75.3% vs 66.1%, P=0.011). Multi-variable analyses showed that male, lower HGB concentration and ELTS intermediate/high-risk cohort were associated with lower cytogenetic and molecular responses rate and poor outcomes in CP patients; higher WBC count and initial the second-generation TKI treatment, the higher response rates; Ph + ACA at diagnosis, poor PFS. However, Sokal intermediate/high-risk cohort was only significantly-associated with lower CCyR and MMR rates and the poor PFS. Lower HGB concentration and larger spleen size were significantly-associated with the lower cytogenetic and molecular response rates in AP patients; initial the second-generation TKI treatment, the higher treatment response rates; lower PLT count, higher blasts and Ph + ACA, poorer TFS; Ph + ACA, poorer OS. Conclusion:At present, the vast majority of newly-diagnosed CML-CP or AP patients could benefit from TKI treatment in the long term with the good treatment responses and survival outcomes.

With the extensive use of neutron sources in industry, medicine, and scientific research, the number of people exposed to neutron has been increasing, which highlights the importance of personal neutron dose monitoring in the field of radiation protection. In the past decades, researchers have developed and improved a variety of techniques and methods for personal neutron dose monitoring. This paper focuses on the problems and research progress of track dosimeters (solid-state nuclear track dosimeters and fluorescent nuclear track dosimeters), luminescent dosimeters (thermoluminescent dosimeters and optically stimulated luminescent dosimeters), and bubble dosimeters in personal neutron dose monitoring.

Objective To preliminarily compare ⁶LiF-⁷LiF and CR39 in individual neutron dose monitoring, and to provide a reference for improving individual neutron dose monitoring. Methods According to the GBZ 128-2019, 26 radiation workers from 7 institutions received individual neutron dose monitoring with ⁶LiF-⁷LiF and CR39 at the same time. The monitoring results were analyzed. Results For most of the workers, the personal neutron dose equivalent H_p(10) was less than the minimum detectable level. The results with the two monitoring methods differed in 6 of 26 workers. Conclusion Both ⁶LiF-⁷LiF and CR39 monitoring methods can be used for individual neutron dose monitoring for radiation workers, but the difference between ⁶LiF-⁷LiF and CR39 (in threshold energy, energy response, etc.) should be considered so that different types of radiation workers receive appropriate individual neutron dose monitoring.

Rats ; Animals ; Adipose Tissue, Brown/physiology* ; Adipose Tissue