Objective To analyze the distribution characteristics of the single nucleotide polymorphism (SNP) site rs76206423 in the promoter region of the interleukin-2 receptor (IL-2R) β gene among Han males in a high radiation background area (HBRA) in Yangjiang City. Methods A total of 48 male participants from Tangkou Town, Yangxi County, Yangjiang City (HBRA group), and 51 male participants from Hengpo Town, Enping City (control group) were selected as the research subjects using the random number table method. Peripheral venous blood samples of participants from both groups were collected, and genomic DNA was extracted. The genotyping and allele frequency distribution of the rs76206423 (A/G) site in the IL-2R β promoter region was detected among the participants in both groups using the SNP detection method. The difference of allele frequencies between population in HBRA group and five area of East Asia, South Asia, Africa, Europe, and the Americas published in the Human Genome Project database from National Center for Biotechnology Information were analyzed. Results The allele frequencies of rs76206423 of population in both groups conformed to Hardy-Weinberg equilibrium (P>0.05). In the HBRA group, the AA genotype was predominant (64.6%), while the AG genotype was the most common in the control group (51.0%), with a significant difference (P<0.05). Population in both groups showed a predominance of the variant allele A (78.1% and 72.5%, respectively), with no significant difference (P>0.05). The frequency of the G allele of rs76206423 in the population in HBRA group was higher than those in South Asian, African, European, and American populations (all P<0.01), but showed no significant difference compared with East Asian populations (P>0.05). Conclusion In the Han male population from the HBRA in Yangjiang City, the rs76206423 site in the IL-2R β gene promoter region is predominantly composed of the wild-type A allele and AA genotype, indicating genetic stability and a relatively high degree of variation at this locus.

Objective To obtain the protective performance parameters of barium sulfate mortar against positron nuclide γ-rays, provide reference data for precise shielding calculations, and guide the design, evaluation, and construction of radiation shielding. Methods The FLUKA program was used to build a model for simulating the dose equivalent rate variation around points of interest under the irradiation of the most commonly used positron nuclide ¹⁸F with changes in the thicknesses of lead and barium sulfate mortar. The transmission curves of lead and barium sulfate mortar were fitted, and the half-value layer (HVL) and lead equivalence of barium sulfate mortar were calculated based on the fitted curves. Results The ambient dose equivalent rate coefficient of positron nuclide ¹⁸F was 1.339 4×10⁻¹ μSv·m²/MBq·h and the HVL for lead was 4.037 mm, with deviations of 0.043% and 1.53% compared to the values provided in the AAPM Report No. 108, respectively. The HVLs for γ-rays produced by ¹⁸F, using barium sulfate mortar with apparent densities of 4.20, 4.00, and 3.90 g/cm³ mixed with 35.2-grade cement in a 4∶1 mass ratio, were 2.914, 2.969, and 3.079 cm, respectively. The lead equivalences were 0.1385, 0.1360, and 0.1311 mmPb/mm, respectively. Conclusion The three types of barium sulfate mortar can provide good protection against γ-rays in positron imaging locations. As the apparent density of barium sulfate increases, its protective effect improves slightly but remains significantly better than common construction materials like concrete and solid bricks.

Objective To simulate and analyze the dose distribution from external exposure and its influencing factors of induced radioactivity in proton therapy site. Methods Referencing a domestically under-construction proton therapy facility, a geometric model of the proton therapy site was constructed, and the FLUKA program was used to simulate the distribution of the induced radioactive dose of the proton therapy site under the conditions of different energies, beam angles, irradiation time, cooling time and medium of the treatment site. Results For a 230 MeV proton beam with a current of 3.0 nA, directed along the negative Z-axis and irradiating a phantom for two minutes, at the shutdown moment, the ambient dose equivalent rates in air and vacuum 5, 30, and 50 cm away from the phantom surface were (1 039.02±5.82)-(127.86±1.20) and (1 037.96±4.38)~(127.35±0.93) μSv/h, respectively. The mean difference was 0.51~1.06 μSv/h, and the air-immersed external irradiation accounted for <1% of the total irradiation, which rapidly decreased to 1/15 of the shutdown moment value after cooling for 10 minutes. Under the condition of 130~250 MeV, the ambient dose equivalent rates at the shutdown moments 5, 30 and 50 cm away from the surface of the phantom were (427.49±3.12)-(1 058.41±4.66), (100.36±0.92)-(259.70±1.69) and (50.15±0.68)-(131.93±1.11) μSv/h, respectively. Irradiation for one-five minutes, and at the moment of shutdown at 5, 30, and 50 cm from the surface of the phantom were (688.19±3.33)-(1 594.04±8.08), (167.60±1.35)-(388.24±2.96) and (84.73±0.69)-(195.94±1.56) μSv/h. The peripheral dose-equivalent rate of the sensed radioactivity decreases with the irradiation time, the energy of the beam, and the distance from the model. The peak dose equivalent rate around the induced radioactivity exists in the beam direction, which is significantly larger than that in the non-beam direction. Conclusion Proton therapy sites are characterized by relatively large levels of induced peripheral radioactive dose equivalent rates, mainly originating from patients. In actual practice, a suitable working position can be chosen according to the direction of the beam current, especially the direction of the final irradiation field beam current, in the non-beam current direction and as far away from the patient as possible. Within 10 minutes after the end of treatment, staff should try to avoid close contact with the patients.

Objective:To investigate the occupational noise hazards in five machinery manufacturing enterprises, and to evaluate the individual noise reduction values and influencing factors of workers wearing hearing protection device (HPD) by individual fit testing.Methods:From November 2021 to January 2022, 5 machinery manufacturing enterprises in Bao'an District of Shenzhen were selected to conduct an occupational health survey to understand the noise exposure level of workers. The 3MTM E-A-RfitTM fitness test system was used to test the baseline individual sound attenuation value level (PAR) of the daily wear of the ear protecters for 485 workers in typical noise working positions. Workers whose PAR values could not meet the requirements of noise reduction at work were instructed to wear and repeated tests were conducted. PAR results of the workers before and after the intervention were collected and analyzed.Results:The noise workers who received the suitability test were mainly distributed in 24 types of work, the job noise exposure level was 80.2 dB (A) ~ 95.0 dB (A), and the job noise excess rate was 52.5% (138/263). The median baseline PAR [ M ( Q1, Q3) ] for 485 workers was 6.0 (0.0, 14.0) dB. The baseline PAR of male workers, those with more than 15 years of working experience, those with more than 15 years of using ear guards, those who considered ear guards comfortable to wear, those with college degree or above, and those exposed to noise level 90 dB (A) were higher, and the difference was statistically significant ( P<0.05). A total of 275 workers (56.7%) did not pass the baseline PAR test, and there was no statistically significant difference in the intervention rate of workers in different noise groups ( P>0.05). PAR in subjects who did not pass baseline after intervention increased from 0.0 (0.0, 3.0) dB to 15.0 (12.0, 18.2) dB. Conclusion:The workplace noise hazard of machinery manufacturing enterprises is serious, and there is a great difference between the baseline PAR and the nominal value of the hearing guard worn by the noise exposed workers. The intervention measures can effectively improve the protective effect of wearing ear protectors.

Objective:To investigate the occupational noise hazards in five machinery manufacturing enterprises, and to evaluate the individual noise reduction values and influencing factors of workers wearing hearing protection device (HPD) by individual fit testing.Methods:From November 2021 to January 2022, 5 machinery manufacturing enterprises in Bao'an District of Shenzhen were selected to conduct an occupational health survey to understand the noise exposure level of workers. The 3MTM E-A-RfitTM fitness test system was used to test the baseline individual sound attenuation value level (PAR) of the daily wear of the ear protecters for 485 workers in typical noise working positions. Workers whose PAR values could not meet the requirements of noise reduction at work were instructed to wear and repeated tests were conducted. PAR results of the workers before and after the intervention were collected and analyzed.Results:The noise workers who received the suitability test were mainly distributed in 24 types of work, the job noise exposure level was 80.2 dB (A) ~ 95.0 dB (A), and the job noise excess rate was 52.5% (138/263). The median baseline PAR [ M ( Q1, Q3) ] for 485 workers was 6.0 (0.0, 14.0) dB. The baseline PAR of male workers, those with more than 15 years of working experience, those with more than 15 years of using ear guards, those who considered ear guards comfortable to wear, those with college degree or above, and those exposed to noise level 90 dB (A) were higher, and the difference was statistically significant ( P<0.05). A total of 275 workers (56.7%) did not pass the baseline PAR test, and there was no statistically significant difference in the intervention rate of workers in different noise groups ( P>0.05). PAR in subjects who did not pass baseline after intervention increased from 0.0 (0.0, 3.0) dB to 15.0 (12.0, 18.2) dB. Conclusion:The workplace noise hazard of machinery manufacturing enterprises is serious, and there is a great difference between the baseline PAR and the nominal value of the hearing guard worn by the noise exposed workers. The intervention measures can effectively improve the protective effect of wearing ear protectors.

Objective:To study the relationship between the dynamic changes of angiopoietin-2 (Ang-2) and surfactant protein D (SP-D) in pediatric acute respiratory distress syndrome (pARDS) and the severity and prognosis of the disease.Methods:Using nested case-control study method, 80 children with pneumonia complicated with pARDS admitted to PICU at Fujian Maternal and Child Health Hospital from June 2018 to May 2021 were selected as pARDS group, and 19 healthy children with corresponding age were selected as control group.According to the oxygenation, the children in pARDS group were divided into three subgroups: mild group (23 cases), moderate group (32 cases) and severe group (25 cases). According to the prognosis at discharge, the children in pARDS group were divided into survival group (67 cases) and death group (13 cases). Ang-2 and SP-D were detected by enzyme-linked immunosorbent assay.The levels of Ang-2 and SP-D in children with pARDS of different severity on the first day were compared; The changes of Ang-2 and SP-D levels on the 1st, 3rd and 8th day of children in survival group and death group were compared, and the receiver operating characteristic (ROC) curve was plotted to compare the predictive value of Ang-2 and SP-D for pARDS prognosis.Results:(1) The levels of Ang-2 and SP-D on the first day in pARDS group were significantly higher than those in control group( P<0.001). (2) The levels of Ang-2 and SP-D on the first day in children with pARDS of different severity levels were significantly different ( P<0.001), and the levels of Ang-2 and SP-D increased gradually with the increase of disease severity.(3) The levels of Ang-2 and SP-D in death group were significantly higher than those in survival group on the 1st, 3rd and 8th day ( P<0.05). (4) Prognostic efficacy of Ang-2 and SP-D levels in pARDS group at different time points: when the areas under the ROC curve predicted by Ang-2 on the 1st, 3rd and 8th day for inpatient mortality in children with pARDS were 0.808, 0.981 and 0.989, respectively; the optimal cut-off values were 6 000 pg/mL, 6 971 pg/mL and 4 171 pg/mL, respectively; the sensitivity was 84.6%, 92.3% and 92.3%, respectively; and the specificity was 76.1%, 97.0% and 98.5%, respectively.The areas under the ROC curve predicted by SP-D on the 1st, 3rd and 8th day for inpatient mortality in children with pARDS were 0.689, 0.993 and 0.983, respectively; the optimal cut-off values were 13544 pg/mL, 16003 pg/mL and 12294 pg/mL, respectively; the sensitivity was 84.6%, 100.0% and 100.0%, respectively; and the specificity was 46.3%, 98.5% and 97.0%, respectively. Conclusion:Serum Ang-2 and SP-D levels in children with pARDS increase with the aggravation of the disease.The dynamic changes of Ang-2 and SP-D in children with pARDS with different prognosis are different during the course of disease, and monitoring serum Ang-2 and SP-D during the course of disease has a certain predictive value for clinical outcome.

Background: Classical swine fever virus (CSFV), the causative agent of classical swine fever (CFS), is a highly contagious disease that poses a serious threat to Chinese pig populations. Objectives: Many provinces of China, such as Shandong, Henan, Hebei, Heilongjiang, and Liaoning provinces, have reported epidemics of CSFV, while the references to the epidemic of CSFV in Yunnan province are rare. This study examined the epidemic characteristics of the CSFV in Yunnan province. Methods: In this study, 326 tissue samples were collected from different regions in Yunnan province from 2015 to 2021. A reverse transcription-polymerase chain reaction (RT-PCR), sequences analysis, and phylogenetic analysis were performed for the pathogenic detection and analysis of these 326 clinical specimens. Results: Approximately 3.37% (11/326) of specimens tested positive for the CSFV by RTPCR, which is lower than that of other regions of China. Sequence analysis of the partial E2 sequences of eleven CSFV strains showed that they shared 89.0–100.0% nucleotide (nt) and 95.0–100.0% amino acid (aa) homology, respectively. Phylogenetic analysis showed that these novel isolates belonged to the subgenotypes 2.1c and 2.1d, with subgenotype 2.1c being predominant. Conclusions The CSFV was sporadic in China’s Yunnan province from 2015 to 2021. Both 2.1c and 2.1d subgenotypes were found in this region, but 2.1c was dominant.

Objective:To assess the risk of noise-induced hearing loss in workers from a petrochemical plant.Methods:In October 2020, 488 male workers exposed to noise in a petrochemical plant in Guangdong Province were selected by cluster sampling. Acoustics-Estimation of Noise-Induced Hearing Loss (ISO 1999: 2013) was used to assess the risk of noise-induced hearing loss of workers, and individual fit testing was used to evaluate the sound attenuation obtained by the workers. The risk assessment results and fitness test results of workers with different hearing levels were compared.Results:The average noise exposure equivalent sound level of the workers in the petrochemical plant was 86.7 dB (A) . The median of PARs (personal attenuation ratings) was 16 (4, 23) dB. There were statistically significant differences in age and service years among workers with different hearing results ( P<0.05) , but no statistically significant differences in noise intensity and PARs ( P>0.05) . According to risk assessment results of ISO 1999: 2013, the current risk of high-frequency hearing loss in 488 workers were negligible risk and acceptable risk. The risk of noise-induced deafness weredivided into three levels: negligible risk in 452 workers (92.7%) , medium risk in 27 workers (5.5%) and high risk in 9 workers (1.8%) . The risk of high-frequency hearing loss in next 5 to 15 years for workers with noise exposure level of >94 to 97 dB and >97 dB or above would be medium risk or above. The risk of noise-induced deafness in next 5 to 15 years for workers exposed to noise withlevel of 91 to 94 dB would be medium risk or above. Conclusion:The risk of noise-induced hearing loss in workers from the petrochemical plant is high in next 5 to 15 years, and noise prevention and control measures need to be strengthened. ISO1999: 2013 assessment method may underestimate the risk of hearing loss among workers.

Objective:To assess the risk of noise-induced hearing loss in workers from a petrochemical plant.Methods:In October 2020, 488 male workers exposed to noise in a petrochemical plant in Guangdong Province were selected by cluster sampling. Acoustics-Estimation of Noise-Induced Hearing Loss (ISO 1999: 2013) was used to assess the risk of noise-induced hearing loss of workers, and individual fit testing was used to evaluate the sound attenuation obtained by the workers. The risk assessment results and fitness test results of workers with different hearing levels were compared.Results:The average noise exposure equivalent sound level of the workers in the petrochemical plant was 86.7 dB (A) . The median of PARs (personal attenuation ratings) was 16 (4, 23) dB. There were statistically significant differences in age and service years among workers with different hearing results ( P<0.05) , but no statistically significant differences in noise intensity and PARs ( P>0.05) . According to risk assessment results of ISO 1999: 2013, the current risk of high-frequency hearing loss in 488 workers were negligible risk and acceptable risk. The risk of noise-induced deafness weredivided into three levels: negligible risk in 452 workers (92.7%) , medium risk in 27 workers (5.5%) and high risk in 9 workers (1.8%) . The risk of high-frequency hearing loss in next 5 to 15 years for workers with noise exposure level of >94 to 97 dB and >97 dB or above would be medium risk or above. The risk of noise-induced deafness in next 5 to 15 years for workers exposed to noise withlevel of 91 to 94 dB would be medium risk or above. Conclusion:The risk of noise-induced hearing loss in workers from the petrochemical plant is high in next 5 to 15 years, and noise prevention and control measures need to be strengthened. ISO1999: 2013 assessment method may underestimate the risk of hearing loss among workers.

Difficult airway is a common condition in the pediatric intensive care unit, which causes great difficulty in endotracheal intubation.Flexible bronchoscopy plays an important role in the evaluation of difficult airway and assists in endotracheal intubation, which has obvious advantages in endotracheal intubation for children with difficult airway.This study discussed the etiological diagnosis and treatment of difficult airway in pediatric intensive care unit and the procedure of endotracheal intubation assisted with flexible bronchoscopy.