Objective To determine the content and distribution characteristics of the artificial radionuclide ¹³⁷Cs and the natural radionuclides ²¹⁰Pb, ²²⁶Ra, ²²⁸Ra, and ⁴⁰K in wild edible fungi, and calculate the committed effective dose due to ¹³⁷Cs and ²¹⁰Pb in wild edible fungi. Methods Thirty samples of wild edible fungi were collected and their caps and stems were separated. A total of 60 samples were measured for ¹³⁷Cs, ²¹⁰Pb, ²²⁶Ra, ²²⁸Ra, and ⁴⁰K using a BE5030 wide-energy, low-background, high-purity germanium γ spectrometer. The paired analysis of the four radionuclides ²²⁶Ra, ²¹⁰Pb, ¹³⁷Cs, and ⁴⁰K was performed using SPSS 11.5. Results Among the 60 samples, the detection rates and dry weight specific activity ranges of ¹³⁷Cs, ²¹⁰Pb, ²²⁶Ra, ²²⁸Ra, and ⁴⁰K were 97% and 0.62-384 Bq/kg, 73% and 6.4-159 Bq/kg, 52% and 0.7-28.8 Bq/kg, 5% and 0.43-2.18 Bq/kg and 100% and （77.4-264) × 10 Bq/kg, respectively. Conclusion Based on the analysis of the 60 samples, the detection rate of radionuclides is in the order of ⁴⁰K, ¹³⁷Cs, ²¹⁰Pb, ²²⁶Ra, and ²²⁸Ra. In terms of the specific activity, the distribution of ⁴⁰K and ²²⁶Ra in wild edible fungi in the same region is basically uniform, while the content of ²¹⁰Pb and ¹³⁷Cs fluctuates in different samples. Although ¹³⁷Cs and ²¹⁰Pb can be detected in most of the wild edible fungi, the annual committed effective dose due to ingestion of wild edible fungi is negligible.

Abstract As a rapid analytical method for both the types and activities of γ radionuclides, the γ-ray spectrometry method is widely used in the measurement of γ radionuclides in environmental and biological samples. The Gamma-ray Spectrometry Method for the Determination of Radionuclides in Environmental and Biological Samples (GB/T 16145—2022）was implemented  on  July  1,  2023,  replacing  the Determination of Radionuclides in Soil by Gamma Spectrometry (GB/T 11743—2013), Determination of Radionuclides in Water by Gamma Spectrometry (GB/T 16140—2018), Gamma Spectrometry Method of Analyzing Radionuclides in Biological Samples (GB/T 16145—2020), and Determination of Radionuclides in Air by Gamma Spectrometry (WS/T 184—2017). The background of the revised standard, the content and basis of the main revisions, and some issues that need to be discussed are briefly explained in this paper, in order to provide a useful reference for the detection of radioactivity in soil, water, biological, and air samples, as well as samples of similar matrices.

Background Bacteria are the most diverse and widely sourced microorganisms in the indoor air of subway stations, where pathogenic bacteria can spread through the air, leading to increased health risks. Objective To understand the status and distribution characteristics of indoor air bacterial pollution in subway stations and compartments in a city of Central South China, and to provide a scientific basis for formulating intervention measures to address indoor air bacteria pollution in subways. Methods Three subway stations and the compartments of trains parking there in a city in Central South China were selected according to passenger flow for synchronous air sampling and monitoring. Temperature, humidity, wind speed, carbon dioxide (CO₂), fine particulate matter (PM_2.5), and inhalable particulate matter (PM₁₀) were measured by direct reading method. In accordance with the requirements of Examination methods for public places-Part 3: Airborne microorganisms (GB/T 18204.3-2013), air samples were collected at a flow rate of 28.3 L·min⁻¹, and total bacterial count was estimated. Bacterial microbial species were identified with a mass spectrometer and pathogenic bacteria were distinguished from non-pathogenic bacteria according to the Catalogue of pathogenic microorganisms transmitted to human beings issued by National Health Commission. Kruskal-Wallis H test was used to compare the subway hygiene indicators in different regions and time periods, and Bonferroni test was used for pairwise comparison. Spearman correlation test was used to evaluate the correlation between CO₂ concentration and total bacterial count. Results The pass rates were 100.0% for airborne total bacteria count, PM_2.5, and PM₁₀ in the subway stations and train compartments, 94.4% for temperature and wind speed, 98.6% for CO₂, but 0% for humidity. The overall median (P₂₅, P₇₅) total bacteria count was 177 (138,262) CFU·m⁻³. Specifically, the total bacteria count was higher in station halls than in platforms, and higher during morning peak hours than during evening peak hours (P<0.05). A total of 874 strains and 82 species were identified by automatic microbial mass spectrometry. The results of identification were all over 9 points, and the predominant bacteria in the air were Micrococcus luteus (52.2%) and Staphylococcus hominis (9.8%). Three pathogens, Acinetobacter baumannii (0.3%), Corynebacterium striatum (0.1%), and Staphylococcus epidermidis bacilli (2.2%) were detected in 23 samples (2.6%), and the associated locations were mainly distributed in train compartments during evening rush hours. Conclusion The total bacteria count in indoor air varies by monitoring sites of subway stations and time periods, and there is a risk of opportunistic bacterial infection. Attention should be paid to cleaning and disinfection during peak passenger flow hours in all areas.

Objective:To investigate the correlation between the neoadjuvant rectal (NAR) score and long-term survival in patients with locally advanced rectal cancer who have undergone neoadjuvant chemoradiotherapy.Methods:Clinical and pathological data of 487 patients diagnosed with rectal adenocarcinoma from October 2004 to April 2014 at Sun Yat-sen University Cancer Center who had received neoadjuvant chemoradiotherapy were retrospectively analyzed and the impact of NAR score on prognosis studied. Disease-free-survival (DFS) was calculated by the Kaplan-Meier method and survivals compared using the log-rank test. Cox models were used for univariate and multivariate analyses. Receiver operating characteristic curves were utilized to evaluate the predictive capability of NAR and tumor regression grade scores for the risk of 10-year postoperative recurrence and metastasis. The Delong test was employed to compare the diagnostic performance of the two scores.Results:Of the 487 patients included in the study, 166 were men (34.1%). The median age was 56 years (interquartile range [IQR]: 46–63). All patients completed adequate preoperative chemoradiotherapy and underwent R0 resection.The median interval between the end of chemoradiotherapy and surgery was 51 days (IQR: 44–58). Post-chemoradiotherapy downstaging occurred in 329 patients (67.6%). Tumor regression grades (TRGs) were 1–2 in 246 patients (50.5%) and 3–4 in 241 patients (49.5%). A total of 394 patients (80.9%) received postoperative chemotherapy. NAR scores were <8 in 182 patients (37.4%), 8–16 in 180 (37.0%), and >16 in 125 (25.6%). The median follow-up time was 111.5 months (IQR: 70.7–133.7 months). One hundred and thirteen patients died of rectal cancer, among whom 13 patients developed local recurrence, 88 patients developed distant metastasis, and 12 patients had unknown recurrence patterns. The 10-year DFS and overall survival rate of f the whole group were 68.9% and 71.5% respectively. The 10-year DFS rates for patients with NAR scores <8, 8–16, and >16 were 85.1%, 80.5%, and 66.4%, respectively ( P<0.001). Multivariate analyses revealed that the Dixon operation (HR=0.606, 95%CI: 0.408–0.902, P=0.014), and >16 (HR=2.569, 95%CI: 1.559–4.233, P<0.001) were independent predictors of the 10-year DFS of patients with locally advanced rectal cancer ( P<0.05 for all). In the entire patient cohort, the AUC of the receiver operating characteristic curve for NAR score predicting 10-year recurrence and metastasis was 0.67 (95%CI: 0.62–0.72), whereas the AUC for TRG score was 0.54 (95%CI: 0.49–0.60). The two scores differed significantly in accuracy ( Z=-4.06, P<0.001), the NAR score being a significantly better predictor of risk of 10-year recurrence and metastasis than the TRG score. Conclusion:The NAR score is a reliable predictor of 10-year DFS in patients with locally advanced rectal cancer who have undergone neoadjuvant chemoradiotherapy followed by curative surgery.

Objective:To investigate the correlation between the neoadjuvant rectal (NAR) score and long-term survival in patients with locally advanced rectal cancer who have undergone neoadjuvant chemoradiotherapy.Methods:Clinical and pathological data of 487 patients diagnosed with rectal adenocarcinoma from October 2004 to April 2014 at Sun Yat-sen University Cancer Center who had received neoadjuvant chemoradiotherapy were retrospectively analyzed and the impact of NAR score on prognosis studied. Disease-free-survival (DFS) was calculated by the Kaplan-Meier method and survivals compared using the log-rank test. Cox models were used for univariate and multivariate analyses. Receiver operating characteristic curves were utilized to evaluate the predictive capability of NAR and tumor regression grade scores for the risk of 10-year postoperative recurrence and metastasis. The Delong test was employed to compare the diagnostic performance of the two scores.Results:Of the 487 patients included in the study, 166 were men (34.1%). The median age was 56 years (interquartile range [IQR]: 46–63). All patients completed adequate preoperative chemoradiotherapy and underwent R0 resection.The median interval between the end of chemoradiotherapy and surgery was 51 days (IQR: 44–58). Post-chemoradiotherapy downstaging occurred in 329 patients (67.6%). Tumor regression grades (TRGs) were 1–2 in 246 patients (50.5%) and 3–4 in 241 patients (49.5%). A total of 394 patients (80.9%) received postoperative chemotherapy. NAR scores were <8 in 182 patients (37.4%), 8–16 in 180 (37.0%), and >16 in 125 (25.6%). The median follow-up time was 111.5 months (IQR: 70.7–133.7 months). One hundred and thirteen patients died of rectal cancer, among whom 13 patients developed local recurrence, 88 patients developed distant metastasis, and 12 patients had unknown recurrence patterns. The 10-year DFS and overall survival rate of f the whole group were 68.9% and 71.5% respectively. The 10-year DFS rates for patients with NAR scores <8, 8–16, and >16 were 85.1%, 80.5%, and 66.4%, respectively ( P<0.001). Multivariate analyses revealed that the Dixon operation (HR=0.606, 95%CI: 0.408–0.902, P=0.014), and >16 (HR=2.569, 95%CI: 1.559–4.233, P<0.001) were independent predictors of the 10-year DFS of patients with locally advanced rectal cancer ( P<0.05 for all). In the entire patient cohort, the AUC of the receiver operating characteristic curve for NAR score predicting 10-year recurrence and metastasis was 0.67 (95%CI: 0.62–0.72), whereas the AUC for TRG score was 0.54 (95%CI: 0.49–0.60). The two scores differed significantly in accuracy ( Z=-4.06, P<0.001), the NAR score being a significantly better predictor of risk of 10-year recurrence and metastasis than the TRG score. Conclusion:The NAR score is a reliable predictor of 10-year DFS in patients with locally advanced rectal cancer who have undergone neoadjuvant chemoradiotherapy followed by curative surgery.

Objective:Three-dimensional reconstruction and finite element analysis were used to investigate the outcomes of different fixation methods on horizontal osteotomy genioplasty and to identify the fixation method with best biomechanics.Methods:The skull spiral CT data of a patient with chin deformity were collected. The mandible three-dimensional model and internal fixation devices were reconstructed by Mimics, Geomagic Studio, Solidworks and Ansys Workbench software. The surgical osteotomy and four internal fixation methods (simple H-shaped titanium plate; 3 lag screws; H-shaped titanium plate combined with bilateral straight titanium plates; H-shaped titanium plate combined with bilateral lag screws) were simulated. The difference of deformation and stress distribution in each fixation under the same load were tested by finite element analysis.Results:The results of H-shaped titanium plate combined with bilateral lag screws fixation were the most balanced, the overall displacement was minimal (0.033 2 mm), the stress concentration of fixation material and free bone was 59.79 MPa and 4.69 MPa, respectively, and the regional stress was small[comparison of the equivalent stress of fixation material between groups, except that it was similar to the three lag screw fixation methods ( P>0.05), it was significantly smaller than the other two fixation methods ( P<0.01); comparison of the equivalent stress of free bone segment between groups, except that it was similar to the simple H-shaped titanium plate fixation method ( P>0.05), it was significantly smaller than the other two fixation methods ( P<0.05)]. Conclusion:The method of H-shaped titanium plate combined with bilateral lag screws fixation in horizontal osteotomy genioplasty has small deformation, which is not easy to cause deformation and fracture of fixation materials, and has superior mechanical properties. It is an appropriate method for clinical application.

Objective:Three-dimensional reconstruction and finite element analysis were used to investigate the outcomes of different fixation methods on horizontal osteotomy genioplasty and to identify the fixation method with best biomechanics.Methods:The skull spiral CT data of a patient with chin deformity were collected. The mandible three-dimensional model and internal fixation devices were reconstructed by Mimics, Geomagic Studio, Solidworks and Ansys Workbench software. The surgical osteotomy and four internal fixation methods (simple H-shaped titanium plate; 3 lag screws; H-shaped titanium plate combined with bilateral straight titanium plates; H-shaped titanium plate combined with bilateral lag screws) were simulated. The difference of deformation and stress distribution in each fixation under the same load were tested by finite element analysis.Results:The results of H-shaped titanium plate combined with bilateral lag screws fixation were the most balanced, the overall displacement was minimal (0.033 2 mm), the stress concentration of fixation material and free bone was 59.79 MPa and 4.69 MPa, respectively, and the regional stress was small[comparison of the equivalent stress of fixation material between groups, except that it was similar to the three lag screw fixation methods ( P>0.05), it was significantly smaller than the other two fixation methods ( P<0.01); comparison of the equivalent stress of free bone segment between groups, except that it was similar to the simple H-shaped titanium plate fixation method ( P>0.05), it was significantly smaller than the other two fixation methods ( P<0.05)]. Conclusion:The method of H-shaped titanium plate combined with bilateral lag screws fixation in horizontal osteotomy genioplasty has small deformation, which is not easy to cause deformation and fracture of fixation materials, and has superior mechanical properties. It is an appropriate method for clinical application.

Objective:To investigate the molecular mechanism of rabbit ear cartilage remodeling induced by 1064 nm Nd∶YAG laser irradiation.Methods:Thirty-three rabbits were divided into 6 groups according to a random number table, and were used in the following experiments respectively: screening the optimal laser energy (6 rabbits), observing the changes of ear cartilage tissue immediately (6 rabbits), 1 week (6 rabbits), 3 weeks (6 rabbits), and 6 weeks after irridiation (6 rabbits), as well as transcriptome sequencing and verification (3 rabbits). The left ears of rabbits were used as untreated self-controls, while the right ears were irradiated. (1) Laser energy screening: the right ear cartilages of 6 rabbits were irradiated with 1064 nm Nd∶YAG laser at different energy densities (50, 60, 70, 80, 90, 100 J/cm 2). Cartilages without skin and perichondrium were cut into the same thickness and size for HE staining, in order to observe the changes of chondrocytes and to determine the optimal laser energy density for shaping (hereinafter referred to as the optimal energy density). (2) Histological observation of rabbit ear cartilage: the right ears of 24 rabbits were irradiated with laser under the optimal energy density. Bilateral cartilage samples were collected immediately after surgery and at 1, 3 and 6 weeks after surgery for histological observation (HE, Masson and Sirius red staining). (3) Transcriptome sequencing and sample verification: the right ears of 3 rabbits were irradiated with laser under the optimal energy density, and the cartilages were harvested and mixed within 6 hours after irradiation, which was set as the laser irradiation group. Cartilages of the same region and size on the left ears were set as blank control group. Transcriptome RNA sequencing was performed, and the expression levels of related genes and proteins were detected by quantitative polymerase chain reaction (qPCR) and Western blotting. Results:(1) After laser irradiation with different energy density of 50-100 J/cm 2, HE staining showed that the chondrocytes could be changed at the laser energy density of 80 J/cm 2, without causing vacuolar deformation and coagulation necrosis, indicating that the damage degree was suitable.(2) After 80 J/cm 2 laser irradiation, histological observation revealed that there was an irradiated zone immediately after the operation. The overall morphology of chondrocytes in the radiation zone was elongated and exhibited spindle cell-like changes, with deep matrix staining and obvious refraction, as well as a relative increase of type Ⅱ collagen. At 1 week after irradiation, the radiation zone became shallower and the cell size recovered. From 3 weeks to 6 weeks, the matrix staining around the radiation zone gradually deepened and the overall cellular morphology was stretched again. (3) Transcriptome RNA sequencing revealed that there were 198 differentially expressed genes (70 up-regulated and 128 down-regulated) in the laser irradiated group compared with the blank control group. Through further screening and study, CREB3L2 gene expression was up-regulated in the laser irradiation group. qPCR results showed that the relative expression level of CREB3L2 mRNA in laser irradiation group was significantly higher than that in the blank control group, the difference was statistically significant( P<0.01). Western blotting showed that the relative expression level of CREB3L2 protein was higher than that of control group in a time-dependent manner, and the difference was statistically significant( P<0.01). Conclusions:After irradiation with long-pulsed 1064 nm Nd∶YAG laser, the expression level of CREB3L2 gene is up-regulated, which then induced chondrocyte rearrangement and proliferation, resulting in morphological and biomechanical changes of ear cartilage.

Objective:To investigate the molecular mechanism of rabbit ear cartilage remodeling induced by 1064 nm Nd∶YAG laser irradiation.Methods:Thirty-three rabbits were divided into 6 groups according to a random number table, and were used in the following experiments respectively: screening the optimal laser energy (6 rabbits), observing the changes of ear cartilage tissue immediately (6 rabbits), 1 week (6 rabbits), 3 weeks (6 rabbits), and 6 weeks after irridiation (6 rabbits), as well as transcriptome sequencing and verification (3 rabbits). The left ears of rabbits were used as untreated self-controls, while the right ears were irradiated. (1) Laser energy screening: the right ear cartilages of 6 rabbits were irradiated with 1064 nm Nd∶YAG laser at different energy densities (50, 60, 70, 80, 90, 100 J/cm 2). Cartilages without skin and perichondrium were cut into the same thickness and size for HE staining, in order to observe the changes of chondrocytes and to determine the optimal laser energy density for shaping (hereinafter referred to as the optimal energy density). (2) Histological observation of rabbit ear cartilage: the right ears of 24 rabbits were irradiated with laser under the optimal energy density. Bilateral cartilage samples were collected immediately after surgery and at 1, 3 and 6 weeks after surgery for histological observation (HE, Masson and Sirius red staining). (3) Transcriptome sequencing and sample verification: the right ears of 3 rabbits were irradiated with laser under the optimal energy density, and the cartilages were harvested and mixed within 6 hours after irradiation, which was set as the laser irradiation group. Cartilages of the same region and size on the left ears were set as blank control group. Transcriptome RNA sequencing was performed, and the expression levels of related genes and proteins were detected by quantitative polymerase chain reaction (qPCR) and Western blotting. Results:(1) After laser irradiation with different energy density of 50-100 J/cm 2, HE staining showed that the chondrocytes could be changed at the laser energy density of 80 J/cm 2, without causing vacuolar deformation and coagulation necrosis, indicating that the damage degree was suitable.(2) After 80 J/cm 2 laser irradiation, histological observation revealed that there was an irradiated zone immediately after the operation. The overall morphology of chondrocytes in the radiation zone was elongated and exhibited spindle cell-like changes, with deep matrix staining and obvious refraction, as well as a relative increase of type Ⅱ collagen. At 1 week after irradiation, the radiation zone became shallower and the cell size recovered. From 3 weeks to 6 weeks, the matrix staining around the radiation zone gradually deepened and the overall cellular morphology was stretched again. (3) Transcriptome RNA sequencing revealed that there were 198 differentially expressed genes (70 up-regulated and 128 down-regulated) in the laser irradiated group compared with the blank control group. Through further screening and study, CREB3L2 gene expression was up-regulated in the laser irradiation group. qPCR results showed that the relative expression level of CREB3L2 mRNA in laser irradiation group was significantly higher than that in the blank control group, the difference was statistically significant( P<0.01). Western blotting showed that the relative expression level of CREB3L2 protein was higher than that of control group in a time-dependent manner, and the difference was statistically significant( P<0.01). Conclusions:After irradiation with long-pulsed 1064 nm Nd∶YAG laser, the expression level of CREB3L2 gene is up-regulated, which then induced chondrocyte rearrangement and proliferation, resulting in morphological and biomechanical changes of ear cartilage.

Objective:Based on the occupational cohort of Beijing Medical Examination Center, to explored the relevant factors of nonalcoholic fatty liver disease (NAFLD), and to provide scientific basis for screening and early diagnosis of NAFLD in high-risk population.Methods:Based on the cohort of occupational population who underwent physical examination in Beijing physical examination center from January to December 2009, the physical examination indexes were collected, and a retrospective survival cohort with a follow-up period of 3 years was established.According to the idea of nested case-control study, each case was randomly matched with the same gender, age and physical examination time in the same month by using the method of random sampling without putting back.Conditional logistic regression model was established by using the matched data.The diagnostic value of related indicators for NAFLD was analyzed by receiver operating characteristic curve (ROC).Results:A total of 1 194 subjects were included, including 684 males (57.3%, 684/1 194) and 510 females (42.7%, 510/1 194). The age was (50.8±11.6) years.The age ranged from 24.0 to 88.0 years.There were 597 patients with NAFLD, including 342 males and 255 females.Logistic regression analysis showed that body mass index, high density lipoprotein cholesterol, hemoglobin, platelet count, uric acid and urea nitrogen were statistically significant in male model (all P<0.05). Body mass index( OR=1.242, 95% CI 1.143-1.349, P<0.001), hemoglobin( OR=1.034, 95% CI 1.015-1.053, P<0.001), platelet( OR=1.005, 95% CI 1.002-1.009, P=0.005), uric acid( OR=1.004, 95% CI 1.001-1.006, P=0.004), high density lipoprotein cholesterol( OR=0.377, 95% CI 0.184-0.775, P=0.008) and urea nitrogen( OR=0.807, 95% CI 0.693-0.938, P=0.005) were protective factors for NAFLD in male patients..Body mass index( OR=1.552, 95% CI 1.366-1.762, P<0.001), triglyceride ( OR=2.606, 95% CI 1.616-4.204, P<0.001), blood glucose( OR=2.199, 95% CI 1.332-3.631, P=0.002), uric acid( OR=1.005, 95% CI 1.001-1.010, P=0.024) in female model were statistically significant ( P<0.05), and were risk factors for NAFLD in female patients. Conclusion:The incidence rate of NAFLD was different among different gender and age, body mass index, high density lipoprotein cholesterol, hemoglobin, platelet count, uric acid, urea nitrogen, triglyceride and blood glucose were closely related to the incidence of NAFLD.