Occupational exposure limits for hazardous agents in the workplace—Part 1: Chemical hazardous agents (GBZ 2.1—2019) has been implemented since April 1, 2020. The document redefines the evaluation of occupational exposure by introducing a "reduction factor" to adjust the occupational exposure limits of chemical hazardous agents for long working hour systems to ensure a protection level reasonable for the workers and equivalent to conventional occupational exposure limits. This paper discussed common problems encountered in the context of using this adjustment strategy, such as the adjustment being unable to cover all working hours, and the adjustment of values of terms associated with occupational exposure limits. Corresponding solutions were proposed. Working cycle and average exposure time of each working cycle were introduced to evaluate the actual working hours of workers. Regarding involved terms, adjustments of their corresponding values were clarified according to their definitions and application scenarios. Examples were provided for occupational health service providers so that their occupational health practices could be carried out in a more scientific and reasonable manner.

BACKGROUND:For dislocation of acromioclavicular joint induced by coracoclavicular ligament fracture,single EndoButton Plate reconstruction and double EndoButton Plates reconstruction are common repair methods.Further study on the stress distribution and fracture risk of the two repair methods is of great significance. OBJECTIVE:To study the biomechanical properties of the coracoclavicular ligament,and compare the fixation effect,stress distribution and failure mode of single and double EndoButton Plates reconstruction. METHODS:(1)Finite element simulation analysis:Mimics,Wrap and SolidWorks were used to establish normal coracoclavicular ligament,single EndoButton Plate reconstruction and double EndoButton Plates reconstruction.Ansys software was used to analyze the stress and deformation of the scapula and clavicle of each model under vertical load.(2)Sample experiment:Fifteen intact scapular-clavicle specimens were randomly grouped into five groups,with three specimens in each group.In group A,the acromioclavicular ligament was severed and the coracoclavicular ligament remained intact.In group B,acromioclavicular ligaments and trapeoid ligaments were severed,leaving intact conical ligaments.In group C,acromioclavicular ligaments and conical ligaments were cut off,and the intact traprex ligaments were retained.In group D,acromioclavicular and coracoclavicular ligaments were severed,and coracoclavicular ligaments were repaired by single EndoButton Plate reconstruction.In group E,acromioclavicular and coracoclavicular ligaments were severed,and the coracoclavicular ligaments were repaired by double EndoButton Plates reconstruction.The mechanical experiment was carried out by a mechanical testing machine to analyze the biomechanical status,stress distribution and failure patterns of the scapular-clavicle and clavicle. RESULTS AND CONCLUSION:(1)Finite element simulation analysis:The average stress of coracoclavicular ligament attached specimens was the lowest,and the risk of coracoclavicular fracture was less than that of single and double EndoButton Plates reconstruction.The mean stress of the coracoid process was similar in single and double EndoButton Plates reconstruction,and the fracture risk was similar.(2)Sample experiment:In groups A,B,C,D and E,the stiffness of specimens was(26.4±3.5),(19.8±2.8),(21.3±3.2),(57.7±4.1),and(46.2±2.8)N/mm,respectively;the ultimate loads were(545.5±53.7),(360.1±42.1),(250.9±44.4),(643.5±39.1),and(511.9±31.7)N,respectively;global stiffness in groups D and E was higher than that in group A(P=0.000 06,0.000 3);ultimate load in group D was higher than that in group A(P<0.05);the ultimate load was not significantly different between the group E and group A(P>0.05).Ligament fracture was observed in groups A,B and C and coracoid process fracture was found in groups D and E.(3)These results suggest that from the biomechanical analysis,Single EndoButton Plate reconstruction and double EndoButton Plates reconstruction are effective treatment techniques for coracoclavicular ligament fracture in acromioclavicular joint dislocation,but increase the risk of fracture.The double EndoButton Plates reconstruction dispersed the stress of the steel plate and reduced the contact force between the steel plate and bone,but slightly reduced the ultimate bearing capacity.Single and double EndoButton Plates reconstruction should be selected according to the actual clinical situation.

Objective:To assess the effectiveness of a 6-month Ba Duan Jin exercise program in improving the balance of community-dwelling older adults.Methods:A two arms, parallel-group, cluster randomized controlled trial was conducted in 1 028 community residents aged 60-80 years in 40 communities in 5 provinces of China. Participants in the intervention group (20 communities, 523 people) received Ba Duan Jin exercise 5 days/week, 1 hour/day for 6 months, and three times of falls prevention health education, and the control group (20 communities, 505 people) received falls prevention health education same as the intervention group. The Berg balance scale (BBS) score was the leading outcome indicator, and the secondary outcome indicators included the length of time of standing on one foot (with eyes open and closed), standing in a tandem stance (with eyes open and closed), the closed circle test, and the timed up to test.Results:A total of 1 028 participants were included in the final analysis, including 731 women (71.11%) and 297 men (28.89%), and the age was (69.87±5.67) years. After the 3-month intervention, compared with the baseline data, the BBS score of the intervention group was significantly higher than the control group by 3.05 (95% CI: 2.23-3.88) points ( P<0.001). After the 6-month intervention, compared with the baseline data, the BBS score of the intervention group was significantly higher than the control group by 4.70 (95% CI: 4.03-5.37) points ( P<0.001). Ba Duan Jin showed significant improvement ( P<0.05) in all secondary outcomes after 6 months of exercise in the intervention group compared with the control group. Conclusions:This study showed that Ba Duan Jin exercise can improve balance in community-dwelling older adults aged 60-80. The longer the exercise time, the better the improvement.

Objective:This study aims to obtain the prevalence and features associated with Violence Against Children (VAC) in China and, thus, formulate a prevention strategy.Methods:The mortality-related data of VAC was sourced from the National Disease Surveillance Points System (DSP) during 2013-2021. We analyzed the DSP data regarding children aged 0-17 years old who died from violence. The hospital cases of VAC was sourced from the National Injury Surveillance System (NISS), 2013-2021. We analyzed the data from NISS with the parameter of "intentional injury" caused by VAC in children aged between 0-17 years. Using robust linear regression, we analyze the time trend in the proportion of violence incidence. To understand the variations in the incidence of different types of violence across genders, we apply the chi-square test and adjusted Pearson residuals.Results:The overall trend of death caused by VAC has declined; it was reduced to 0.14/100 000 in 2021 from 0.33/100 000 in 2013. In 2021, male VAC mortality (0.15/100 000) was higher than females (0.13/100 000). The proportion of VAC cases to all injury cases has declined from 3.34% in 2013 to 2.29% in 2021. Among 9 344 VAC cases supervised by hospitals in 2021, the number of males (7 503 cases) was around 4 times that of females (1 841 cases), and the top three modes of violence were blunt tools (64.77%), falls (7.46%) and sharp instruments (6.18%), and 45 cases of sexual violence included 38 girls and 7 boys.Conclusions:The declining death rate due to VAC may be related to the benign development of Chinese society. Prevention strategies targeting training in parenting skills and problem-solving should be prioritized.

Purpose::Mannitol is one of the first-line drugs for reducing cerebral edema through increasing the extracellular osmotic pressure. However, long-term administration of mannitol in the treatment of cerebral edema triggers damage to neurons and astrocytes. Given that neural stem cell (NSC) is a subpopulation of main regenerative cells in the central nervous system after injury, the effect of mannitol on NSC is still elusive. The present study aims to elucidate the role of mannitol in NSC proliferation.Methods::C57 mice were derived from the animal house of Zunyi Medical University. A total of 15 pregnant mice were employed for the purpose of isolating NSCs in this investigation. Initially, mouse primary NSCs were isolated from the embryonic cortex of mice and subsequently identified through immunofluorescence staining. In order to investigate the impact of mannitol on NSC proliferation, both cell counting kit-8 assays and neurospheres formation assays were conducted. The in vitro effects of mannitol were examined at various doses and time points. In order to elucidate the role of Aquaporin 4 (AQP4) in the suppressive effect of mannitol on NSC proliferation, various assays including reverse transcription polymerase chain reaction, western blotting, and immunocytochemistry were conducted on control and mannitol-treated groups. Additionally, the phosphorylated p38 (p-p38) was examined to explore the potential mechanism underlying the inhibitory effect of mannitol on NSC proliferation. Finally, to further confirm the involvement of the p38 mitogen-activated protein kinase-dependent (MAPK) signaling pathway in the observed inhibition of NSC proliferation by mannitol, SB203580 was employed. All data were analyzed using SPSS 20.0 software (SPSS, Inc., Chicago, IL). The statistical analysis among multiple comparisons was performed using one-way analysis of variance (ANOVA), followed by Turkey's post hoc test in case of the data following a normal distribution using a Shapiro-Wilk normality test. Comparisons between 2 groups were determined using Student's t-test, if the data exhibited a normal distribution using a Shapiro-Wilk normality test. Meanwhile, data were shown as median and interquartile range and analyzed using the Mann-Whitney U test, if the data failed the normality test. A p < 0.05 was considered as significant difference. Results::Primary NSC were isolated from the mice, and the characteristics were identified using immunostaining analysis. Thereafter, the results indicated that mannitol held the capability of inhibiting NSC proliferation in a dose-dependent and time-dependent manner using cell counting kit-8, neurospheres formation, and immunostaining of Nestin and Ki67 assays. During the process of mannitol suppressing NSC proliferation, the expression of AQP4 mRNA and protein was downregulated, while the gene expression of p-p38 was elevated by reverse transcription polymerase chain reaction, immunostaining, and western blotting assays. Subsequently, the administration of SB203580, one of the p38 MAPK signaling pathway inhibitors, partially abrogated this inhibitory effect resulting from mannitol, supporting the fact that the p38 MAPK signaling pathway participated in curbing NSC proliferation induced by mannitol.Conclusions::Mannitol inhibits NSC proliferation through downregulating AQP4, while upregulating the expression of p-p38 MAPK.

Objective:To assess the value of combined chromosomal karyotyping and chromosomal microarray analysis (CMA) and/or copy number variation sequencing (CNV-seq) for the prenatal diagnosis for women with advanced maternal ages, and to explore the challenges of prenatal genetic counseling brought by the types of fetal CNVs and uncertainty of related phenotypes.Methods:A retrospective analysis was carried out on 1 841 women with advanced maternal age who underwent interventional prenatal diagnosis at the Prenatal Diagnosis Center of Xiamen University Affiliated Women and Children′s Hospital from January 2017 to December 2020. Routine chromosomal karyotyping analysis and CMA/CNV-seq detection were carried out.Results:CMA/CNV-seq had detected pathogenic variants in 2 cases which had failed karyotyping analysis. Two hundred and twenty one fetal chromosomal abnormalities were detected by karyotyping analysis, among which 187 were detected by CMA/CNV-seq. CMA/CNV-seq analysis of 23 cases with balanced chromosome structural aberrations and 10 cases with low proportion mosaicisms (including a marker chromosome) had yielded a negative result. In addition, 26 cases (26/1 841, 1.4%) with pathogenic CNVs were discovered among those with a normal karyotype, of which 13 (50.0%) were recurrent CNVs associated with neurocognitive impairment, with 22q11.21 microdeletions and microduplications being the most common types (26.92%).Conclusion:The combination of karyotyping analysis and CMA/CNV-seq not only increased the rate of prenatal diagnosis, but also complemented with each other, which has facilitated genetic counseling and formulation of prenatal diagnosis strategy for the affected families.

Objective:To determine the total and age-specific cut-off values of total prostate specific antigen (tPSA) and the ratio of free PSA divided total PSA (fPSA/tPSA) for screening prostate cancer in China.Methods:Based on the Chinese Colorectal, Breast, Lung, Liver, and Stomach cancer Screening Trial (C-BLAST) and the Tianjin Common Cancer Case Cohort (TJ4C), males who were not diagnosed with any cancers at baseline since 2017 and received both tPSA and fPSA testes were selected. Based on Cox regression, the overall and age-specific (＜60, 60-＜70, and ≥70 years) accuracy and optimal cut-off values of tPSA and fPSA/tPSA ratio for screening prostate cancer were evaluated with time-dependent receiver operating characteristic curve (tdROC) and area under curve (AUC). Bootstrap resampling was used to internally validate the stability of the optimal cut-off value, and the PLCO study was used to externally validate the accuracy under different cut-off values.Results:A total of 5 180 participants were included in the study, and after a median follow-up of 1.48 years, a total of 332 prostate cancer patients were included. In the total population, the tdAUC of tPSA and fPSA/tPSA screening for prostate cancer were 0.852 and 0.748, respectively, with the optimal cut-off values of 5.08 ng/ml and 0.173, respectively. After age stratification, the age specific cut-off values of tPSA in the <60, 60-<70, and ≥70 age groups were 3.13, 4.82, and 11.54 ng/ml, respectively, while the age-specific cut-off values of fPSA/tPSA were 0.153, 0.135, and 0.130, respectively. Under the age-specific cut-off values, the sensitivities of tPSA screening for prostate cancer in males <60, 60-70, and ≥70 years old were 92.3%, 82.0%, and 77.6%, respectively, while the specificities were 84.7%, 81.3%, and 75.4%, respectively. The age-specific sensitivities of fPSA/tPSA for screening prostate cancer were 74.4%, 53.3%, and 55.9%, respectively, while the specificities were 83.8%, 83.7%, and 83.7%, respectively. Both bootstrap's internal validation and PLCO external validation provided similar results. The combination of tPSA and fPSA/tPSA could further improve the accuracy of screening.Conclusion:To improve the screening effects, it is recommended that age-specific cut-off values of tPSA and fPSA/tPSA should be used to screen for prostate cancer in the general risk population.

Objective:To provide supports for the cancer prevention and control strategies in China by comparing the disease burden, epidemic trends, 5-year relative survival rate and major determinants of common cancers between China and the United States.Methods:A descriptive secondary analysis was conducted using data extracted from the GLOBOCAN database, the Surveillance, Epidemiology, and End Results database, Global Burden of disease 2019 database, and previous studies. The main indicators included the cases of malignant tumors in different sites, the cases of deaths, the age-standardized incidence (world standard incidence) and mortality (world standard mortality), the 5-year relative survival rate, and population attributable fraction (PAF).Results:In 2022, an estimated 4.825 million new cases and 2.574 million deaths of malignant neoplasms in China. The world standard incidence rate (201.6/100 000) in China was lower than that in the United States (367.0/100 000), and the world standard mortality rate (96.5/100 000) was higher than that in the United States (82.3/100 000). Lung cancer ranked first in the disease burden of malignant tumors in China, the new cases and deaths accounted for 22.0% and 28.5% of all malignant tumors, respectively. The top three malignant tumors in China were breast cancer (11.5%), prostate cancer (9.7%) and lung cancer (9.5%), which were also among the top five causes of death. However, the second to fifth leading causes of death from malignant tumors in China were digestive system tumors (liver cancer 12.3%, stomach cancer 10.1%, colorectal cancer 9.3%, and esophageal cancer 7.3%). From 2000 to 2018, the world standard incidence of malignant tumors showed an increasing trend and the world standard mortality of malignant tumors showed a decreasing trend in China, while the world standard incidence and mortality of malignant tumors in the United States showed a significant decreasing trend after 2000. The incidence of breast cancer, colorectal cancer and thyroid cancer increased rapidly in China, while the incidence and mortality of stomach cancer, liver cancer and esophageal cancer decreased, but they still had a heavy disease burden. From 2003 to 2015, the overall 5-year relative survival rate of malignant tumors increased from 30.9% to 40.5% in China. However, with the exception of esophageal cancer, the 5-year relative survival rates of other major malignant tumors were lower than those in the United States. In 2019, the PAF of malignant tumors death attributable to potential modifiable risk factors was 48.3% in China, which was similar to the United States (49.8%). Of these, smoking was the most important attributable risk factor, and the PAF was more than 30% both in China and the United States. In addition, about 18.8% of malignant tumors were caused by preventable chronic infections, such as hepatitis B virus and Helicobacter pylori, while less than 4% of malignant tumors in the United States were caused by infection.Conclusions:China has made great progress in the prevention and treatment of malignant tumors, but it still faces a serious disease burden. The cancer spectrum is changing from developing countries to developed countries. We should pay attention to modifiable factors, take comprehensive measures, and prevent cancer scientifically.

Objective To investigate the effects of different ventilation strategies on intraocular pressure (IOP) and intracranial pressure in patients undergoing spinal surgery in the prone position under general anesthesia. Methods Seventy-two patients undergoing prone spinal surgery under general anesthesia between November, 2022 and June, 2023 were equally randomized into two groups to receive routine ventilation (with Vt of 8mL/kg, Fr of 12-15/min, and etCO2 maintained at 35-40 mmHg) or small tidal volume hyperventilation (Vt of 6 mL/kg, Fr of18-20/min, and etCO2 maintained at 30-35 mmHg) during the surgery. IOP of both eyes (measured with a handheld tonometer), optic nerve sheath diameter (ONSD;measured at 3 mm behind the eyeball with bedside real-time ultrasound), circulatory and respiratory parameters of the patients were recorded before anesthesia (T0), immediately after anesthesia induction (T1), immediately after prone positioning (T2), at 2 h during operation (T3), immediately after supine positioning after surgery (T4) and 30 min after the operation (T5). Results Compared with those at T1, IOP and ONSD in both groups increased significantly at T3 and T4 (P<0.05). IOP was significantly lower in hyperventilation group than in routine ventilation group at T3 and T4 (P<0.05), and ONSD was significantly lower in hyperventilation group at T4 (P<0.05). IOP was positively correlated with the length of operative time (r=0.779, P<0.001) and inversely with intraoperative etCO2 at T3 (r=-0.248, P<0.001) and T4 (r=-0.251, P<0.001). ONSD was correlated only with operation time (r=0.561, P<0.05) and not with IOP (r=0.178, P>0.05 at T3;r=0.165, P>0.05 at T4). Conclusion Small tidal volume hyperventilation can relieve the increase of IOP and ONSD during prone spinal surgery under general anesthesia.

Objective:To explore risk factors for refracture after percutaneous kyphoplasty(PKP)in elderly patients with osteoporotic vertebral compression fractures(OVCF)and provide clinical guidance.Methods:A retrospective analysis was conducted on clinical data from elderly patients with OVCF who underwent PKP surgery at the Department of Orthopedics, Shanxi Bethune Hospital, between January 2017 and December 2022.All patients were followed up for a minimum of one-year post-surgery.The elderly patients were categorized into a refracture group(59 cases)and a non-refracture group(200 cases)based on post-surgery refracture occurrence.Univariate analysis was initially conducted on the collected data, followed by multivariate Logistic regression analysis on statistically significant indicators to identify risk factors for refracture in elderly patients with OVCF following PKP.Results:The results of the univariate analysis indicated that there was no statistically significant difference in gender, history of diabetes mellitus, history of smoking, history of hormone medication, and body mass index(BMI)between the refracture group and the non-refracture group of elderly patients.However, the refracture group was found to be older than the non-refracture group( t=9.085, P=0.003).Additionally, there were no significant differences in preoperative indicators such as preoperative calcium, preoperative phosphorus, and site of first fracture(all P>0.05).The time from first fracture to surgery being greater than 14 days was more common in the refracture group compared to the non-refracture group( χ2=20.409, P=0.001), and the number of vertebrae fractured for the first time was higher in the re-fracture group( t=6.189, P=0.017).Cement injection method, amount of cement injected, and distribution of cement did not show significant differences between the two groups(all P>0.05).However, there were statistically significant variations in the proportion of postoperative anti-osteoporosis treatment( χ2=13.431, P=0.001)and bone mineral density( χ2=13.431, P=0.001)between the refracture and non-refracture groups.Furthermore, multifactorial Logistic regression analysis revealed that increasing age( OR=1.061, 95% CI: 1.021-1.103, P=0.003), time from first fracture to surgery exceeding 14 days( OR=5.026, 95% CI: 1.968-12.835, P=0.001), lack of anti-osteoporosis treatment( OR=3.493, 95% CI: 1.239-9.846, P=0.018), and decreased bone mineral density( OR=10.682, 95% CI: 2.707-42.151, P=0.001)were identified as influential factors in the occurrence of secondary vertebral compression fracture after surgery. Conclusions:The independent risk factors for refracture after PKP in elderly patients with OVCF include increasing age, time from first fracture to surgery greater than 14 days, lack of anti-osteoporosis treatment, and decreased bone mineral density.In clinical practice, targeted interventions can be implemented for prevention and effective management based on these risk factors to enhance the prognosis of elderly patients with OVCF.