This paper primarily reviews the current research status of passive and active monitoring methods for interventional radiology personnel, encompassing the types and wearing positions of personal dosimeters, simulation results versus measured outcomes, and discrepancies between different simulation results. By reviewing domestic and international literature, it lists effective dose estimation formulas for single- and dual-dosimeter systems developed by various researchers worldwide. Recommendations are proposed based on the current dosimeter wearing practices among interventional radiology staff, providing reference for the formulation of relevant standards.

Objective To analyze personal external exposure dose monitoring results of pet hospital radiation workers in Beijing from 2022 to 2024, and to provide scientific evidence for developing effective monitoring protocols, standardizing radiological practices in pet hospitals, and protecting the health of both workers and the public. Methods Personal dose equivalents, H_p(10), were measured using GR-200A thermoluminescent dosimeters. Monitoring included radiation workers at 286 pet hospitals across all 16 districts of Beijing from 2022 to 2024. Each monitoring cycle lasted no more than 90 days. Annual effective doses were calculated by summing the results of four consecutive quarterly cycles. Data were processed and analyzed using Access and TLPS 6.41 software. All evaluations complied with national laws, regulations, and technical standards. Results A total of 1,579 person-time measurements were recorded. Only 51.87% of workers completed the full four-cycle annual monitoring schedule. Over the study period, the mean annual effective dose was 0.29 mSv, and the median dose was 0.14 mSv. The collective effective dose was 238.34 man-mSv. Notably, 94.26% of workers had annual effective doses below 1.0 mSv, and only 0.12% had doses at or above 5 mSv. Dose levels showed a statistically significant downward trend (P<0.05). Both independent and chain-branded clinics had a median annual effective dose of 0.14 mSv. In independent clinics, the proportion of workers with doses below 1.0 mSv increased from 80.77% in 2022 to 98.82% in 2024. In chain-branded clinics, this proportion rose from 96.88% to 98.11% over the same period. Conclusion Radiation exposure among pet hospital workers in Beijing remains at low levels, well below regulatory limits, and shows an overall declining trend. The disparity in personal doses between independent and chain-branded pet hospitals has diminished over time. Nevertheless, the industry still faces challenges such as high staff turnover and low monitoring completion rates. Expanding monitoring coverage and harmonizing protection standards would provide a scientific basis for precise, nationwide regulation.

Objective This study compared organ doses and effective doses in typical adult patients during dental CBCT examinations using a head-and-neck anthropomorphic phantom and a whole-body phantom. It aimed to determine an appropriate method for evaluating effective dose in dental CBCT. Methods A domestically manufactured dental CBCT unit was used to scan an adult male anthropomorphic phantom under simulated clinical conditions. Thermoluminescent dosimeters were placed on organs and tissues of a whole-body anthropomorphic phantom. Organ equivalent doses were measured, and effective doses were calculated using two approaches: one based on all organ doses from the whole-body phantom, and the other based only on head-and-neck organ doses. Entrance surface air kerma (K_a,e) was also measured at the lens of the eye, thyroid, thymus, and gonads. Results The effective dose estimated with the whole-body phantom was 382.03 μSv. The effective dose estimated with the head-and-neck phantom was 354.03 μSv. The radiation dose to head-and-neck organs and tissues accounted for 92.7% of the total effective dose. The highest K_a,e values were found in the parotid glands, followed by the lens of the eye. Conclusion During dental CBCT scanning, the contribution of organ below the head and neck to the total effective dose is limited. To simplify dose assessment procedures, the effective dose for the patient can be evaluated using only a head-and-neck phantom.

Chemiluminescence,as a self-luminous phenomenon that does not require light,heat,acoustic,electric and magnetic excitation,has been widely used in the fields of analytical chemistry,cold light source and bio-imaging because of its advantages including high sensitivity,wide linear range,simple equipment and fast detection speed compared with other analytical techniques.Carbon dots(CDs)are a class of nanomaterials with excellent photoluminescence properties and high biocompatibility.CDs are stable,easy to prepare and abundant in types,and researchers have introduced many types of CDs into different chemiluminescence systems.In this paper,the applications of CDs in common chemiluminescence systems and the possible mechanisms of action were discussed,and the research progresses on the application of CDs in different chemiluminescence detection fields in recent years were summarized.Finally,the development trend of CDs in chemiluminescence was analyzed.

Near infrared spectroscopy(NIRS)analysis technology has become an important process analysis tool in industrial and agricultural production,and has been widely used for qualitative and quantitative analysis in the fields of tobacco,agriculture,and pharmaceuticals.To address issues such as poor generalization ability and low prediction accuracy in NIRS modeling,a two-dimensional convolutional neural network(2DCNN)quantitative analysis model based on competitive adaptive reweighted sampling(CARS)and Gramian angular difference field(GADF)(CARS-GADF-2DCNN)was proposed.CARS-GADF-2DCNN used the CARS method to select an optimal wavelength set from the full spectrum,then employed GADF to encode the selection results into two-dimensional images,and finally used 2DCNN for prediction analysis.The 2DCNN model consisted of convolutional layers,parallel convolution modules,flattening layer,and fully connected layers.Simulation experiments were conducted on three public near-infrared(NIR)spectral datasets encompassing soil,tablet,and grain datasets to evaluate the CARS-GADF-2DCNN model.The results demonstrated that,compared to the one-dimensional convolutional neural network(1DCNN),the GADF-2DCNN model achieved 16.74％,23.40％,and 7.13％improvement in prediction accuracy for the soil,tablet,and grain datasets,respectively.Compared to GADF-2DCNN,VCPA-GADF-2DCNN,and IRIV-GADF-2DCNN models,the CARS-GADF-2DCNN model further improved prediction accuracy.For the soil dataset,prediction accuracy improved by 39.00％,30.78％and 4.13％;for the tablet dataset,the improvements were 9.52％,6.94％and 2.56％;for the grain dataset,the improvements were 20.57％,9.85％and 15.66％.In conclusion,CARS-GADF-2DCNN effectively selected the optimal wavelength subset from near infrared spectra,and revealed the latent features between different wavelengths.CARS-GADF-2DCNN addresses the issues of high complexity in prediction models and low prediction accuracy in near infrared spectral modeling,and could be effectively applied to near infrared spectral prediction analysis of different substances.

Aim To study the difference in hepatotox-icity of psoralen on normal rats and Yin-deficiency rats from the perspective of lipid metabolism,so as to help explain the mechanism of psoralen cautiously used in patients with Yin deficiency recorded in ancient books.Methods SD rats were randomly divided into the nor-mal control group(carboxymethyl cellulose-Na,CMC-Na),normal administration group(CMC-Na+psor-alen),Yin-deficiency control group(CMC-Na+thy-roxine)and Yin-deficiency administration group(CMC-Na+thyroxine+psoralen).The model of Yin-deficiency was established by thyroxine(1 mg·kg-1)for ten days,and then psoralen(200 mg·kg-1)was given for three days.The serum indexes related to liver injury were detected by automatic biochemical analy-zer,the morphological changes of liver tissue were ob-served using HE and oil red O staining,and the relative transcription levels of lipid metabolism related enzymes and mRNA of transporter and endoplasmic reticulum stress related factors were detected using Real-time PCR.Results After intragastric administration of psoralen for three days,compared with the normal group,the levels of serum alanine aminotransferase(ALT),aspartate transaminase(AST),total bile acid(TBA)and triglyeride(TG)in Yin deficiency group increased more significantly,while TC,ALB and TP de-creased more significantly,and liver HE and oil red O staining showed more obvious lipid degeneration.TG synthesis factors adrenocortical carcinoma(ACC),fatty acid synthase(FASN)and sterolregulatory element binding protein-1(SREBP-1)were down-regulated more significantly,TG transport factors mili-total pro-tein(MTP)and lipoprotein pipase(LPL)were down-regulated more evidently,fatty acid β-oxidation related factors carnitine palmitoyltransferase 1A(CPT1A),carnitine/organic cation transporter 2(OCTN2)and peroxisome proliferators-activated receptors-alpha(PPARα)were down-regulated more apparently,TC transporter adenosine triphosphate binding cassette transporter G8(ABCG8)and bile acid receptor farne-soid X receptor(FXR)were down-regulated more ob-viously,and endoplasmic reticulum stress factor activa-ting transcription factor 4(ATF4)was up-regulated more significantly.Conclusions Psoralen can cause more severe hepatotoxicity in Yin deficiency rats than that in normal administration group,and its mechanism may be related to the disorder of hepatic lipid metabo-lism,aggravation of hepatic cholestasis and steatosis,and activation of endoplasmic reticulum stress re-sponse.

Objective:To investigate the prevalence of flight fatigue among helicopter flying personnel and analyze its contributors in order to provide data for related interventions.Methods:A cross-sectional study was conducted among 404 helicopter flying personnel between October 8, 2021 and July 31, 2022. Data was collected using a self-designed questionnaire, involving the demography of these subjects, sleep-related factors, flight fatigue, perceived causes of fatigue and coping strategies. The Pittsburgh Sleep Quality Index (PSQI), National Aeronautics and Space Administration Task Load Index (NASA-TLX) and Modified Fatigue Impact Scale (MFI-20) were used to assess sleep quality, mental workload, and levels of flight fatigue over the past month. The total scores of MFI-20 were compared across demographic groups, and correlations with PSQI and NASA-TLX scores were analyzed. Multiple linear regression was performed to identify the determinants of flight fatigue.Results:①Demography: among the 404 helicopter flying personnel, 92.8% (375/404) were pilots and 7.2% (29/404) navigators. As for years of service, 41.6% (168/404) served less than 5 years, while 58.4% (236/404) served more than 5 years. 37.9% (153/404) had a family history of insomnia. 18.8% (76/404) did not habitually nap, 68.9% (226/328) napped for ≤30 min, 31.1% (102/328) napped over 30 min, and 18.3% (74/404) had insomnia over the past month. As for helicopter flying personnel, 75.5% (305/404) reported experiencing fatigue, with 69.1% (279/404) attributing it to flight-related factors and 51.5% (208/404) using coffee as a countermeasure.②Scale scores: the total score of PSQI was [5 (3, 7)], while the highest daytime dysfunction score was [1(0, 2)]. The total score of NASA-TLX was [39.19 (26.57, 51.97)], and the effort score was the highest [10.31(5.07, 14.60)]. The total score of MFI-20 averaged (47.28±14.88), with the mental fatigue score being the highest [(10.03±4.42)]. ③Comparisons of MFI-20 total scores: flying personnel with ≤5 years of flying experience had higher MFI-20 total scores than those with >5 years, and those with a family history of insomnia had higher scores than those without ( t=3.35, 2.44, P=0.001, 0.015). Individuals with insomnia over the past month had higher scores than non-insomniacs ( t=3.33, P=0.001). Significant differences in MFI-20 scores were observed based on nap duration ( F=19.95, P<0.001). Non-nappers had higher scores than those napping for ≤30 min ( P=0.005). Flying personnel who napped for >30 min had higher scores than those did not ( P=0.043) or napped for ≤30 min ( P<0.001). ④Correlation analysis: the total score of MFI-20 was positively correlated with sleep quality, sleep latency, sleep disturbances, hypnotic medications, daytime dysfunction, and the total score of PSQI ( r=0.118-0.226, all P<0.05), but negatively with sleep duration ( r=-0.136, P=0.006). The total score of MFI-20 was positively correlated with mental demand, physical demand, and the total score of NASA-TLX ( r=0.119, 0.168, 0.184, P=0.017, 0.001, <0.001). ⑤Multiple linear regression analysis: the determinants of flight fatigue included aircraft types ( B=-4.956, 95% CI:-8.124--1.788), nap duration ( B=3.693, 95% CI: 1.267-6.119), sleep latency ( B=2.371, 95% CI: 0.229-4.513), sleep duration ( B=-7.383, 95% CI:-10.008--4.758), daytime dysfunction ( B=5.003, 95% CI: 2.967-7.039) and physical workload ( B=0.611, 95% CI: 0.324-0.898). Conclusions:Helicopter flying personnel are vulnerable to flight fatigue, which is strongly linked to sleep quality and mental workload. It is crucial to address flying personnel′s self-perceived fatigue, care about fatigue manifestations across aircraft types, and implement targeted interventions to improve sleep quality and reduce mental workload.

OBJECTIVE: CRISPR-Cas protects bacteria from exogenous DNA invasion and is associated with bacterial biofilm formation and pathogenicity. METHODS: We analyzed the type I-F CRISPR-Cas system of Legionella pneumophila WX48, including Cas1, Cas2-Cas3, Csy1, Csy2, Csy3, and Cas6f, along with downstream CRISPR arrays. We explored the effects of the CRISPR-Cas system on the in vitro growth, biofilm-forming ability, and pathogenicity of L. pneumophila through constructing gene deletion mutants. RESULTS: The type I-F CRISPR-Cas system did not affect the in vitro growth of wild-type or mutant strains. The biofilm formation and intracellular proliferation of the mutant strains were weaker than those of the wild type owing to the regulation of type IV pili and Dot/Icm type IV secretion systems. In particular, Cas6f deletion strongly inhibited these processes. CONCLUSION The type I-F CRISPR-Cas system may reduce biofilm formation and intracellular proliferation in L. pneumophila.
Legionella pneumophila/pathogenicity* ; CRISPR-Cas Systems ; Biofilms/growth & development* ; Phenotype ; Bacterial Proteins/metabolism* ; Gene Deletion

Objective:To develop and assess a deep learning-based model for automatic segmentation of organs at risk (OARs) in postoperative brachytherapy for endometrial carcinoma (EC).Methods:A retrospective study was conducted on the computed tomography (CT) images of 108 EC patients who received high-dose-rate (HDR) 192Ir intracavitary vaginal-cuff brachytherapy (VCB) at the Peking University Third Hospital from November 2021 to October 2022. Then, the rectum, colon, small intestine, and bladder in these images were manually segmented. These patients were randomly divided into two groups using a random number table: 90 cases for training the 3D no-new-U-Net (nnU-Net) segmentation model and 18 cases for model testing. The precision and clinical applicability of the automatic segmentation model were assessed using geometric indexes including Dice similarity coefficient (DSC), Hausdorff distance (HD), and mean surface distance (MSD), as well as dose-volume parameters (DVPs) including the minimum dose to 0.1, 1.0, and 2.0 cm 3 of OARs that received the highest irradiation doses ( D0.1 cm 3, D1.0 cm 3, and D2.0 cm 3). Results:The 3D nnU-Net model yielded mean DSC values of 0.90, 0.85, 0.88, and 0.95, respectively for the segmentations of the rectum, colon, small bowel, and bladder, all of which were better than those of the 3D U-Net and V-Net models. The differences among the three models were statistically significant ( F = 21.78, 24.33, 36.00, 20.11, P < 0.001). The 3D nnU-Net exhibited statistically significant differences in HD values for the colon, small intestine, and bladder segmentations among the three method ( F = 17.33, 24.11, 6.33, P < 0.05). The 3D nnU-Net model yielded lower MSD values for the segmentations of all organs compared to the control model, with statistically significant differences ( F = 29.78, 27.11, 27.11, 14.78, P < 0.001). No statistically significant difference was found in all DVPs between the 3D nnU-Net model-based and manual segmentations ( P > 0.05). Bland-Altman analysis demonstrated great consistency between the 3D nnU-Net and manual segmentations. Conclusions:The 3D nnU-Net-based model exhibits high geometric accuracy and dosimetric consistency with manual segmentation of OARs in brachytherapy, holding potential to improve clinical efficiency.