BACKGROUND:The most common complication of traumatic femoral neck fractures after internal fixation is femoral head necrosis.Currently,many studies have reported on the risk factors that affect the occurrence and development of postoperative femoral head necrosis,but there is still a lack of tools to predict the risk of femoral head necrosis after internal fixation of femoral neck fractures.OBJECTIVE:To develop a predictive model that estimates the risk of femoral head necrosis shortly after patients with femoral neck fractures receive cannulated screw internal fixation.METHODS:A retrospective analysis reviewed clinical records of 172 patients who underwent cannulated screw internal fixation for femoral neck fractures at Department of Orthopedics of Mianyang Central Hospital from January 2013 to June 2023.Patients were categorized into two groups based on the presence or absence of femoral head necrosis within one year post-operation:the necrosis group and the non-necrosis group.Univariate analysis,Lasso regression,and multivariate Logistic regression techniques were employed to identify the determinants of femoral head necrosis.A nomogram prediction model was constructed using R language's"rms"package,version 4.0.The receiver operating characteristic curve was used to evaluate the discriminatory ability of the model.The Hosmer-Lemeshow test was used to evaluate the goodness of fit of the model,and the decision curve analysis was used to determine its clinical application benefits.Internal validation of the study was conducted using the Bootstrap method,involving 1 000 repeated samplings.To delve deeper into the primary factors influencing femoral head necrosis post-internal fixation of the femoral neck,this paper employed the SHAP method for data set analysis.RESULTS AND CONCLUSION:(1)The risk factors leading to femoral head necrosis in the short term after cannulated screw fixation of femoral neck fractures include:smoking,diabetes,Garden classification,fracture line location,reduction quality,age,and operation time.(2)The prediction model demonstrated robust performance,evidenced by an area under the curve of 0.940(95％Confidence Interval:0.903 to 0.977),indicating a high level of prediction accuracy.The model achieved a sensitivity of 90.2％and a specificity of 87.6％,indicating that its diagnostic performance was stable.The Hosmer-Lemeshow goodness-of-fit test yielded a chi-square value of 6.593 with a P-value of 0.581,confirming that the model's predictions closely align with the observed outcomes.(3)The calibration curve of the model also performed well,and its overall trend was very close to the ideal curve,further proving the high accuracy of the model.(4)The internal validation was carried out by the Bootstrap method with 1 000 repeated samplings,and the area under the curve of the model internal validation was still as high as 0.939,proving that the model had good stability.(5)Through the decision curve,it is found that within the probability threshold range of 1％to 92％,the model can obtain the maximum net benefit value.(6)The SHAP analysis results show that among the risk factors analyzed in this study,the location of the fracture line serves as the most significant predictor of femoral head necrosis following internal fixation with cannulated screws in femoral neck fractures,and subcapital fractures are extremely prone to femoral head necrosis after surgery.(7)It is concluded that the validated prediction model demonstrates strong discriminative power and reliability,offering practical clinical utility.It serves as a useful reference tool for short-term risk assessment of femoral head necrosis following internal fixation of femoral neck fractures.

BACKGROUND:The most common complication of traumatic femoral neck fractures after internal fixation is femoral head necrosis.Currently,many studies have reported on the risk factors that affect the occurrence and development of postoperative femoral head necrosis,but there is still a lack of tools to predict the risk of femoral head necrosis after internal fixation of femoral neck fractures.OBJECTIVE:To develop a predictive model that estimates the risk of femoral head necrosis shortly after patients with femoral neck fractures receive cannulated screw internal fixation.METHODS:A retrospective analysis reviewed clinical records of 172 patients who underwent cannulated screw internal fixation for femoral neck fractures at Department of Orthopedics of Mianyang Central Hospital from January 2013 to June 2023.Patients were categorized into two groups based on the presence or absence of femoral head necrosis within one year post-operation:the necrosis group and the non-necrosis group.Univariate analysis,Lasso regression,and multivariate Logistic regression techniques were employed to identify the determinants of femoral head necrosis.A nomogram prediction model was constructed using R language's"rms"package,version 4.0.The receiver operating characteristic curve was used to evaluate the discriminatory ability of the model.The Hosmer-Lemeshow test was used to evaluate the goodness of fit of the model,and the decision curve analysis was used to determine its clinical application benefits.Internal validation of the study was conducted using the Bootstrap method,involving 1 000 repeated samplings.To delve deeper into the primary factors influencing femoral head necrosis post-internal fixation of the femoral neck,this paper employed the SHAP method for data set analysis.RESULTS AND CONCLUSION:(1)The risk factors leading to femoral head necrosis in the short term after cannulated screw fixation of femoral neck fractures include:smoking,diabetes,Garden classification,fracture line location,reduction quality,age,and operation time.(2)The prediction model demonstrated robust performance,evidenced by an area under the curve of 0.940(95％Confidence Interval:0.903 to 0.977),indicating a high level of prediction accuracy.The model achieved a sensitivity of 90.2％and a specificity of 87.6％,indicating that its diagnostic performance was stable.The Hosmer-Lemeshow goodness-of-fit test yielded a chi-square value of 6.593 with a P-value of 0.581,confirming that the model's predictions closely align with the observed outcomes.(3)The calibration curve of the model also performed well,and its overall trend was very close to the ideal curve,further proving the high accuracy of the model.(4)The internal validation was carried out by the Bootstrap method with 1 000 repeated samplings,and the area under the curve of the model internal validation was still as high as 0.939,proving that the model had good stability.(5)Through the decision curve,it is found that within the probability threshold range of 1％to 92％,the model can obtain the maximum net benefit value.(6)The SHAP analysis results show that among the risk factors analyzed in this study,the location of the fracture line serves as the most significant predictor of femoral head necrosis following internal fixation with cannulated screws in femoral neck fractures,and subcapital fractures are extremely prone to femoral head necrosis after surgery.(7)It is concluded that the validated prediction model demonstrates strong discriminative power and reliability,offering practical clinical utility.It serves as a useful reference tool for short-term risk assessment of femoral head necrosis following internal fixation of femoral neck fractures.

Objective:To evaluate the current situation of the protective effect of hearing protection device (HPD) worn by manufacturing workers and discuss their possible influencing factors.Methods:A total of 3634 noisy workers were surveyed and tested. The study conducted surveys of workers on the use of HPD. The 3M TM E-A-R Fit TM binaural verification system was used to measure the personal attenuation device (PAR) of workers wearing HPD. Results:The M ( Q1, Q3) of baseline PAR obtained by 3634 workers was 12 (2, 19) dB. There was a statistically significant difference in baseline PAR among the three types of HPDs ( H=336.39, P<0.01) . After pairwise comparison, it was found that the baseline PAR of workers wearing foam earplugs and earmuffs was higher than that of pre-molded earplugs ( P<0.01) . There were differences in baseline PAR among workers in different industries ( Z=359.73, P<0.01) . Education level, age of using HPD, types of HPDs, noise exposure intensity, with or without knowledge of correct methods, and comfort evaluation were the main factors affecting baseline PAR ( P<0.05) . There were 1536 workers (43.4%) failed the baseline PAR test. After the intervention, the median PAR increased significantly from 1 (0, 6) dB (baseline) to 18 (14, 22) dB (after the intervention) ( P<0.01) . The follow-up test found that the follow-up PAR of 328 workers was higher than the baseline PAR of the initial test, and the follow-up PAR was higher than the post-intervention PAR of the initial test ( P<0.01) . Conclusion:Under the conditions of this study, the protective effect of HPD was affected by factors such as incorrect understanding of wearing methods, exposure to high-intensity noise, low education level, a short period of time of HPD use and low comfort of hearing protectors. The protective effect could be improved through training, optimizing the wearing of hearing protector models, and follow-up interventions. Enterprises should use suitability verification to ensure the correct selection and wearing of noisy workers.

Objective:To explore the intimal injury of two kinds of hemostatic clips under different clamping forces, and to optimize and verify the calculation formula of minimum occlusion force (MOF), so as to provide theoretical basis for selecting appropriate hemostatic clips to reduce vascular injury.Methods:A total of 96 male SD rats with body weight ranging from 280 to 300 g (Animal Experimental Center of Shanxi Medical University) were randomly assigned to metal hemostatic clip group ( n=48) and disposable hemostatic clip group ( n=48) by random number table method. Each group was further divided into four subgroups with clamping forces of 0.3, 0.6, 0.9 and 1.2 N for abdominal aortic injury experiments. The damage to the vascular intima was observed under a scanning electron microscope. A vascular closure model was established for mathematical analysis to derive the theoretical calculation formula of the arterial blood management factor (MOF). According to blood pressure (BP), blood vessel diameter (D) and hemostatic clamp width (W), the average values of theoretical and actual MOF data were analyzed by paired t test to verify the accuracy of the formula. From January 2021 to December 2022, six patients (with 12 branch arteries) who presented with oral and maxillofacial malignancies at the Department of Oral and Maxillofacial Surgery, Shanxi Medical University School and Hospital of Stomatology, were included to validate the accuracy of the MOF formula. Results:Under electron microscopy, when the clamping force was 0.3 N, the one-time hemostatic clip caused very little damage to the vascular intima (grade 1 injury), with only a few folds being flattened. When the clamping force was 0.6 N, both types of hemostatic clips caused partial peeling of the intima surface (grade 2-3 injury). However, when the clamping force was adjusted to 0.9 and 1.2 N, the damage caused by both types of hemostatic clips was more severe (grade 3-4 injury), with large areas of intima peeling or even disappearance. In some specimens of the metal hemostatic clip group, the damage even reached the muscular layer. Vascular closure model analysis showed that MOF=2×(1/2×π×D×W×BP), the mean diameter of abdominal aorta of 24 SD rats was (1.41±0.07) mm, the blood pressure was (83.29±11.56) mmHg (1 mmHg=0.133 kPa). The theoretical MOF value was (0.096±0.015) N, the actual clamping force (ACF) was (0.095±0.012) N, there was no statistical significance between the two groups ( t=-0.35, P=0.725). In clinical application, the MOF calculation formula was used to select the appropriate hemostatic clip for 12 arteries, successfully blocking the blood flow, verifying the accuracy of the formula. Conclusions:Hemostatic clips can cause damage to the inner membrane of blood vessels, and the greater the clamping force, the more severe the damage. Disposable hemostatic clips have certain advantages in avoiding excessive damage to the inner membrane of blood vessels. The theoretical MOF calculation formula has a certain degree of reliability and can be used as a reference to select the appropriate hemostatic clip with low damage.

[Purpose]To analyze the survival of lung cancer,liver cancer and stomach cancer in Jiashan County,Zhejiang Province from 2006 to 2020.[Methods]From January 1,2006 to De-cember 31,2020,new cases of lung cancer,liver cancer and stomach cancer were collected in Jiashan County,Zhejiang Province.The 5-year observed survival rate(OSR),relative survival rate(RSR)and age-standardized relative survival rate(ARSR)by sex and age were calculated from 2006-2010,2011-2015 and 2016-2020.The observed and relative survivals were calculated using the lifetime table and Ederer Ⅱ methods,respectively,and age standardized using the Inter-national Cancer Survival Standard.Joinpoint software was utilized to compute the average annual percentage change(AAPC)for analyzing trends in various survival rates from 2006 to 2020.[Re-sults]The 5-year RSR of lung cancer,liver cancer and stomach cancer increased from 8.1％,4.8％and 23.2％(2006-2010)to 36.0％,17.6％and 48.2％(2016-2020),showing an increasing trend(AAPC=14.4％,AAPC=11.4％,AAPC=6.4％,respectively,all P＜0.05).Accordingly,the 5-year RSR of three types of malignant tumors showed an increasing trend in both men and women(all P＜0.05)except liver cancer in women(P＞0.05).The 5-year RSR of three types of malignant tu-mors in the age groups of 0～64 and 65+years old showed a significant increasing trend(all P＜0.05).The increase of lung cancer and liver cancer was greater in the age group of 0～64 years old,and the increase of gastric cancer was greater in the age group of 65+years old.[Conclusion]The 5-year survival rates of the three types of malignant tumors with the highest mortality risk in Jiashan County,Zhejiang Province all increased significantly from 2006 to 2020,indicating that the pre-vention and treatment effect of malignant tumors is significant,but the survival rate of malignant tumors varied significantly among different populations,so targeted intervention should be carried out.

[Purpose]To analyze the survival of colorectal cancer patients in Jiashan County of Zhejiang Province from 1991 to 2020.[Methods]The data of newly reported cases of colorectal cancer were collected in Jiashan County from January 1,1991 to December 31,2020,and pa-tients were followed-up till December 2023.The observed survival rate(OSR)and relative survival rate(RSR)were calculated using the life table and Ederer Ⅱ method with 5-year intervals.Rela-tive survival was adjusted using the International Cancer Survival Standards.The Joinpoint re-gression model was used to calculate the average annual percentage change(AAPC)to analyze the change trend of survival rate.[Results]The 5-year RSR of colorectal cancer increased from 21.7％during 1991 to 1995 to 73.4％during 2016 to 2020,showing an increasing trend(AAPC=4.6％,P＜0.05),for men it increased from 17.7％to 72.7％and for women it increased from 30.0％to 74.3％,with AAPCs of 3.9％and 4.3％,respectively(P＜0.05).The 5-year RSR of colorectal can-cer in all age groups showed an increasing trend(P＜0.05 for all age groups,except for 75+),and the highest increase was found in the age group of 65～74 years old(AAPC=4.9％).[Conclusion]From 1991 to 2020,the 5-year survival rate of colorectal cancer in Jiashan County showed a steady increase,for women and those aged 65～74 years old the increase was more significant.The cancer screening of high-risk groups should be focused on to improve colorectal cancer survival rate.

Objective:To evaluate the image quality and radiation dose in contrast-enhanced thoracic-abdominal-pelvic CT using automatic tube voltage modulation (ATVM) coupled with artificial intelligence iterative reconstruction (AIIR) versus routine tube voltage combined with Karl-3D iterative reconstruction (Karl-3D IR), and to determine the optimal noise level for AIIR in contrast-enhanced thoracic-abdominal-pelvic CT.Methods:A total of 100 patients who underwent contrast-enhanced thoracic-abdominal-pelvic CT examination in the Affiliated Hospital of Hebei University from April to October, 2023 were randomly divided into group A and group B using a random number table, with 50 patients in each group. Group A was scanned using ATVM, and images were reconstructed using AIIR with 1-5 noise levels. Group B was scanned using tube voltage 120 kVp and images were reconstructed with Karl-3D IR and noise level 5. The single-to-noise ratio (SNR), contrast-to-noise ratio (CNR), effective dose (E), and size-specific dose estimate (SSDE) were recorded or calculated for all patients or images. Subjective evaluations of all images were performed. The quality of the reconstructed images using AIIR with 1-5 noise levels were compared and the optimal noise level of AIIR for image reconstruction was determined. Image quality and radiation dose were statistically analyzed for Group A (image reconstruction with optimal AIIR noise level) and Group B.Results:The mean SNR and mean CNR of the reconstructed images using AIIR with noise levels 1, 2, and 3 in group A were higher than those using AIIR with noise levels 4 and 5. The images reconstructed using AIIR with noise levels 3 and 4 scored higher in subjective assessment than those reconstructed using AIIR with noise levels 1, 2, and 5. Therefore, noise level 3 was optimal for AIIR in reconstruction of contrast-enhanced thoracic-abdominal-pelvic CT images. The mean SNR, mean CNR, and subjective evaluation score of group A using AIIR with noise level 3 were higher than those of group B using Karl-3D IR with noise level 5 ( P<0.001). The mean SSDE and the mean E of group A were reduced by 46% and 41%, respectively, compared with those of group B. Conclusions:ATVM technology combined with the AIIR algorithm can improve image quality and reduced patient radiation dose in contrast-enhanced thoracic-abdominal-pelvic CT. Noise level 3 is optimal for AIIR in the reconstruction of arterial-phase and venous-phase contrast-enhanced thoracic-abdominal-pelvic CT images.

Objective:To investigate the fit of dust-exposed workers wearing KN95 masks in a city of Guangdong Province, and to discuss the intervention effect of nose pads and elastic adjustment clasps on the fit of KN95 masks.Methods:In January 2024, 145 dust-exposed workers from a stone processing enterprise in a city of Guangdong Province were selected as study subjects by convenience sampling, and 4 types of KN95 masks commonly used by dust-exposed workers were selected as test masks. The head and face dimensions of the study subjects were measured using a right-angle gauge and a curved-angle gauge, and the fit factor (FF) of the KN95 masks was tested using the quantitative fit test for respiratory protective equipment, and the intervention of adding nose pads or elastic adjustment clasps was given to those who failed the first fit test. The paired t-test was used to compare the changes of workers' FF before and after the intervention. Results:The coverage rate of the study population in the facial subsection of the Chinese Han population was 71.0% (103/145). Before intervention, the overall passing rate of the fit test of 4 types of KN95 masks was 16.6% (24/145), and the passing rate of 4 types of masks had statistical significance ( χ2=19.73, P<0.001). After intervention, the overall passing rate of the fit test of masks was 33.9% (41/121), and the geometric mean of the total FF after intervention increased from 15.9 to 62.7 ( t=-13.53, P<0.001), among which 88.4% (107/121) workers' FF improved after intervention, and 11.6% (14/121) of workers had reduced FF. Conclusion:Dust-exposed workers in a city of Guangdong Province have a low coverage rate of facial subsection among Chinese Han population, and the passing rate of KN95 mask fit test is low. Interventions using additional nose pads or elastic adjustment clasps can partially improve the fit of the mask, and it is still necessary to continue to explore interventions to improve the fit of mask wearers.

Objective:To understand the current status of the actual protective effect of respiratory protective equipment (RPE) for workers exposed to trichloroethylene (TCE), and to explore the factors affecting the actual protective effect.Methods:From July to December 2023, a total of 75 workers occupationally exposed to TCE from 21 hardware and electronics manufacturing facilities in a province were selected as research objects by convenient sampling method. Workplace protection factor (WPF) was used as an index to evaluate the actual protective effect of workers' RPE. The concentration of TCE inside and outside the RPE was detected to calculate WPE, and the temperature, humidity and wind speed near the working place were measured, as well as the forced vital capacity, respiratory rate, heart rate and other indicators of the worker were measured. The log-transformed WPF value (lgWPF) followed a normal distribution. One-sample t-test was used to compare the difference between the mean lgWPF and the log value of the assigned protection factor (APF) of the half mask (lgAPF=1). Multiple linear regression model was used to investigate the influencing factors of lgWPF. Results:The lgWPF of 75 TCE-exposed workers ranged from 0.40 to 1.32 (0.84±0.22). The mean of lgWPF was lower than that of lgAPF, and the difference was statistically significant ( t=-6.37, P<0.001). After adjusting for confounding factors, the results of multiple linear regression showed that humidity, forced vital capacity and respiratory rate were negatively correlated with lgWPF ( β=-0.008, -0.079, -0.021, P<0.05) . Conclusion:The actual protective efficacy of RPE among workers exposed to TCE is suboptimal. High humidity, elevated forced vital capacity, and increased respiratory rate may be contributing factors to the diminished protective performance of RPE.

Objective:To understand the occupational injury situation of front-line workers in metallurgical and shipbuilding and repairing industry, and explore the risk factors of occupational injury.Methods:From September 2023 to March 2024, using cluster sampling method, front-line workers from 2 metallurgical enterprises in Shaoguan and Jinan City and 2 shipbuilding and repairing enterprises in Jiangmen and Shenzhen City were selected as the investigation objects. 6248 questionnaires were distributed and collected, and 6178 were effective questionnaires, with a effective recovery rate of 98.88%. The basic information, living habits, working system, protection and occupational injury of workers were investigated, and the data of occupational injury in factories was collected. The types, jobs and main causes of occupational injuries in different industries were analyzed, and the influencing factors of occupational injuries were analyzed by univariate and multi-factor logistic regression.Results:The incidence of occupational injury was 3.13% (128/4086) in metallurgical industry and 4.02% (84/2092) in shipbuilding and repairing industry. The top three occupational injuries in the metallurgical industry were furnace worker (17.19%, 22/128), steel rolling worker (14.84%, 19/128), maintenance worker (10.16%, 13/128), and the top three injury types were mechanical injury (24.22%, 31/128), height fall (20.31%, 26/128) and object strikes (17.97%, 23/128). The top three occupational injuries in shipbuilding and repairing industry were welder (20.24%, 17/84), riveter (9.52%, 8/84) and crane (8.33%, 7/84). The top three injury types were hit by objects (34.52%, 29/84), hit by falling objects (22.62%, 19/84), and lifting injury (20.24%, 17/84). The injuries of workers in metallurgical industry and shipbuilding and repairing industry were mainly fractures, accounting for 32.03% (41/128) and 60.71% (51/84), respectively. The incidence of occupational injury was higher in males, with sleep disorder, high temperature exposure and chemical toxicity exposure ( P<0.05). There were significant differences in age, smoking degree, working age and emotional state between workers with occupational injury and those without occupational injury ( P<0.05). Multivariate analysis showed that male, age above 50 years old, moderate smoking, working years of 5-9 years, mild anxiety, poor health status and high temperature exposure were risk factors for occupational injury ( OR=25.57, 3.72, 14.27, 2.09, 1.50, 4.36, 0.66, P<0.05) . Conclusion:The incidence of occupational injury is higher in shipbuilding and repairing industry, and fracture is the main type of occupational injury. The occurrence of occupational injury is affected by gender, age, smoking, working age, emotional state, health status and high temperature exposure.