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.

ObjectiveTo make clear exercise combined with Shenghui Tang interferes in acetylcholine receptor （M1AChR） to improve mitochondrial autophagy and enhance cognition of Alzheimer's disease （AD） model rats through the adenylate activated protein kinase （AMPK）/mammalian target of rapamycin （mTOR） signaling pathway. MethodsForty-eight male SD rats of SPF grade were randomly divided into a blank group， a model group， a Shenghui Tang group （9.3 g·kg^-1）， an exercise group， an exercise + Shenghui Tang group （9.3 g·kg^-1）， and a rapamycin group （1.5 mg·kg^-1）. Except for the blank group， the rat model of AD was constructed by injecting amyloid beta （Aβ_1-42） into hippocampus stereotaxically. The exercise group received treadmill exercise for 4 weeks， while the Shenghui Tang group received intragastric administration for 4 weeks， and the exercise + Shenghui Tang group received treadmill exercise and intragastric administration of Shenghui Tang for 4 weeks simultaneously. After the intervention， the Morris water maze test was used to detect the learning and memory ability. Spontaneous behavior was observed in the open field test. The pathological structure of hippocampal neurons was observed by NISSl staining. The expression level of M1AChR in hippocampus was detected by immunohistochemistry （IHC）. The autophagy ultrastructure of hippocampal neurons was observed by transmission electron microscopy. The apoptosis rate was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL）. The expression of Beclin1 and microtubule-associated protein light chain 3β （LC3β） was detected by immunofluorescence （IF）. The protein expression of M1AChR， AMPK， p-AMPK， mTOR， Beclin1， LC3β， and chelate 1 （SQSTM1/p62） in hippocampus was detected by Western blot. ResultsCompared with the blank group， the model group exhibited significantly increased platform escape latency on the fifth day （P<0.01） and significantly decreased activity distance in the target quadrant and times of crossing the platform （P<0.01）. The total movement distance in the open field， the time of movement in the central area， and the average speed obviously decreased （P<0.05）. The arrangement of nerve cells in hippocampus CA1 region was dispersed， and the numbers of Nissl bodies and M1AChR positive cells significantly decreased （P<0.01）. The expression of TUNEL positive cells was significantly increased （P<0.01）. The typical autophagic lysosomal structure decreased. The protein expression of M1AChR， p-AMPK/AMPK， p-mTOR/mTOR， Beclin1， LC3Ⅱ/Ⅰ in hippocampus was significantly decreased （P<0.01）， and the protein expression of p62 was significantly increased （P<0.01）. Compared with the model group， the exercise + Shenghui Tang group exhibited obviously improved space exploration and positioning navigation ability （P<0.05， P<0.01）. The total movement distance in the open field， the time of movement in the central area， and the average speed of movement significantly increased （P<0.01）. The number of Nissl bodies significantly increased （P<0.01）. The number of M1AChR positive cells in hippocampus was significantly increased （P<0.01）. The expression of TUNEL positive cells was significantly decreased （P<0.01）. The protein expression of M1AChR， p-AMPK/AMPK， p-mTOR/mTOR， Beclin1， LC3Ⅱ/Ⅰ in hippocampus was significantly increased （P<0.01）， while the protein expression of p62 was significantly decreased （P<0.01）. Compared with the exercise + Shenghui Tang group， the Shenghui Tang group and the exercise group showed significantly increased platform escape latency on the fifth day （P<0.01） and obviously decreased activity distance in the target quadrant and times of crossing the platform （P<0.05， P<0.01）. The total movement distance in the open field， the time of movement in the central area， and the average speed of movement significantly decreased （P<0.01）. The number of Nissl bodies and the number of M1AChR positive cells significantly decreased （P<0.01）. The expression of TUNEL positive cells was obviously increased （P<0.05）. Ultrastructure of the hippocampal region showed decreased autophagy level. The protein expression of M1AChR， p-AMPK/AMPK， p-mTOR/mTOR， LC3Ⅱ/Ⅰ in the hippocampus was obviously decreased in the Shenghui Tang group （P<0.05， P<0.01）， while the protein expression of p62 was significantly increased （P<0.01）. In the exercise group， the protein expression of M1AChR， p-AMPK/AMPK， Beclin1， and LC3Ⅱ/Ⅰ was obviously decreased （P<0.05， P<0.01）， while the protein expression of p-mTOR/mTOR and p62 was significantly increased （P<0.01）. ConclusionExercise combined with traditional Chinese medicine can enhance the expression of M1AChR in the hippocampus of AD model rats， induce autophagy through the AMPK/mTOR signaling pathway， and improve the learning and memory ability of AD rats.

Background/Aims: Regorafenib is recommended by guidelines and trials as a sequential second-line therapy following progression on first-line sorafenib or lenvatinib in hepatocellular carcinoma (HCC). However, efficacy is limited, highlighting the urgent need to screen suitable patients and develop sensitization strategies. Methods: Acquired sorafenib- or lenvatinib-resistant (SR or LR) HCC cell lines and organoids were established. Genome-wide CRISPR library screen was performed in SR or LR cell strains to identify synthetic lethal targets of regorafenib. RNA-seq and FITC-regorafenib efflux assay were used to elucidate ERBB3-driven downstream signaling. Preclinical mouse models of cell line- and patient-derived xenografts and clinical cohorts of HCC patients were employed to validate the efficacy of ERBB3-guided patient stratification. Results: Screening with CRISPR library, we showed that inhibition of ERBB3 was synthetic lethal with regorafenib in SR or LR cell strains and organoids. Mechanistically, SR or LR triggered feedback activation of ERBB3 signaling and mediated regorafenib efflux via ERBB3-HIF1A-ABCB1 cascade pathway, limiting sensitivity to regorafenib. Moreover, ERBB3-low tumors following SR or LR exhibited significant sensitivity to regorafenib, suggesting its potential as a predictive biomarker to screen optimal candidates for sequential therapy. Seribantumab, an ERBB3-targeting monoclonal antibody, inhibited ERBB3-HIF1A-ABCB1 cascade, and its combination with regorafenib exerted marked synergistic anti-tumor effects on ERBB3-high tumors resistant to sorafenib or lenvatinib both in vitro and in vivo. Conclusions This study revealed that ERBB3 was a key resistance factor driving limited efficacy to sequential regorafenib, but also an effective therapeutic target whose inhibition enhanced regorafenib sensitivity after SR or LR.

Objective To understand mosquito density, species composition, and seasonal variations around the Beijing Capital International Airport(BCIA)and provide scientific evidence for mosquito-borne disease prevention and control. Methods Meteorological data were collected from 2016 to 2022, and mosquito density was monitored at seven surveillance sites around the BCIA from May to October each year using CO2-baited mosquito traps to analyze the relationship between mosquito density and meteorological factors. Results In total,68 518 female mosquitoes were captured, with a mosquito density of 10.20 per light · hour. The dominant species was Culex pipiens pallens(73.90%), followed by Aedes albopictus(9.71%)and Ae. vexans(9.29%);the mosquito density was highest in 2016(14.8 per light·hour)and lowest in 2022(4.46 per light·hour). Significant statistical differences were observed in mosquito density among different species(F=18.118, P<0.05). The density of Cx. pipiens pallens and other mosquito species showed a mutually exclusive trend; the peak of mosquito density varied based on years and habitats, with significant statistical differences in mosquito density among different habitats(F=8.504, P<0.05). The highest mosquito density was observed near the Wenyu River(21.50 per light·hour), whereas the lowest was recorded at the BCIA construction site(2.44 per light· hour). The monthly average temperature(r=0.595), monthly average highest temperature(r=0.575), and monthly average lowest temperature(r=0.624)showed moderate positive correlations, whereas the monthly average air pressure(r=-0.484)showed a moderate negative correlation. The monthly average minimum temperature was included in the regression model(F=25.575, P<0.000), and the equation Y=1.029X4-8.181 was used. The monthly average air pressure 2 months prior(b=-2.418, β=-1.619, P<0.05)and the monthly average relative humidity(b=-0.739, β=-1.201, P<0.05)significantly negatively predicted the mosquito density. Notably, the regression equation used was y=2526.170+(-2.418)X9+(-0.739)X13. The exposure-response analysis revealed that the density of mosquitoes was not linearly related to the average monthly air pressure, rainfall, and duration of sunshine. Conclusions The dominant mosquito species around the BCIA was Cx. pipiens pallens, Ae. albopictus, and Ae. vexans. During the control of Cx. pipiens pallens, the impact on other mosquito species must also be considered. Environmental management, breeding sites, and scientific use of pesticides should be prioritized based on the activity periods of mosquitoes. Further studies on mosquitoes and meteorological factors should be conducted to provide references and novel avenues for mosquito control.

Objective To investigate the capacity of municipal and county-level Centers for Disease Control (CDC) in Shandong Province for γ radionuclides in food as well as gross α and gross β in drinking water, and to provide evidence for strengthening radiological laboratories. Method Data regarding radioactive detection capacity were collected from 16 prefecture-level cities and 136 county-level CDCs. Chi-square test and Fisher's exact tests were used to compare capacity differences across regions and between cities with and without nuclear power plants. Correlation analysis was used to evaluate the spatial equity of gross α and gross β detection capacity for drinking water. Result The detection capacity of gross α and gross β in drinking water varied significantly among counties (χ²=81.026, P<0.001），no significant difference was found between coastal and inland cities (χ²=2.021，P>0.155); Cities with nuclear power plants showed better detection capacity (χ²=20.253，P<0.01). The detection capacity for γ radionuclides in food was primarily concentrated in the prefecture-level cities that host nuclear power plants. Conclusion The overall detection capacity for radioactivity in drinking water was acceptable but spatially uneven. The capacity for monitoring radioactive contamination in food was generally weak. It is necessary to strengthen capacity building at the grassroots level.

Objective To investigate and compare the epidemiological characteristics of common respiratory viruses among influenza-like illness(ILI)and severe acute respiratory infection(SARI)cases in Huzhou,Zhejiang Province before and after the COVID-19 pandemic,so as to provide a basis for formulating and adjusting the prevention and control strategies for viral respiratory infectious diseases.Methods ILI and SARI cases at two influenza surveillance sentinel hospitals in Huzhou and had throat swab samples collected during Nov 2017 to Feb 2020(pre-COVID-19 pandemic period)and Dec 2022 to Apr 2024(post-COVID-19 mitigation phase)were selected as the participants.Seven common viral respiratory pathogens were tested,including influenza A virus(H1N1 and H3N2 subtypes),influenza B virus(Victoria lineage,FluB),respiratory syncytial virus(RSV),rhinovirus(HRV),adenovirus(ADV),and severe acute respiratory syndrome coronavirus-2(SARS-CoV-2).The positive rates of respiratory pathogens before and after the COVID-19 pandemic were compared across different age groups and different time.Results A total of 7 948 ILI samples and 2 294 SARI samples were included.The overall positive rate of ILI samples increased from 33.6%to 47.1%,primarily due to the increase in influenza and COVID-19 infections;the overall positive rate of SARI samples decreased from 31.4%to 24.8%,mainly due to the reduction in HRV and ADV infections.During the post-COVID-19 mitigation phase,SARS-CoV-2(22.1%),H3N2(12.7%),and FluB(6.0%)were the primary pathogens in ILI samples,while RSV(7.1%),H3N2(5.3%),and HRV(4.5%)dominated in SARI samples.During the post-COVID-19 mitigation phase,the influenza virus circulation period was shortened.Before the COVID-19 pandemic,RSV was mainly detected in autumn and winter,while during the post-COVID-19 mitigation phase,out-of-season RSV epidemics were observed in spring and summer.Co-infection rate in ILI cases increased significantly in the post-COVID-19 mitigation phase,predominantly consisting of co-infections of COVID-19 and influenza A virus,while co-infection rate in SARI cases showed a decline.Conclusion We found important epidemiological changes in respiratory viruses in Huzhou during the post-COVID-19 mitigation phase compared to pre-COVID-19 period,including increased positive rates of influenza and COVID-19,and disruptions to the seasonal patterns of influenza and RSV.The prevention and control strategies should be adjusted in a timely manner based on the monitoring data.

Objective:To explore the efficacy and safety of sivelestat sodium in patients with acute respiratory distress syndrome (ARDS) in the intensive care unit (ICU).Methods:Sixty patients with ARDS admitted to the ICU of the Fuyang Hospital Affiliated to Anhui Medical University from August 1, 2023 to November 1, 2024 were selected and divided into the control group (conventional treatment, 30 cases) and the sivelestat sodium group (treated with sivelestat sodium in addition to conventional treatment, 30 cases) by the random number table method. The clinical data such as inflammatory factors, blood gas analysis indicators, Acute Physiology and Chronic Health Evaluation (APACHE) Ⅱ score and Sequential Organ Failure Assessment (SOFA) score of the two groups of patients before treatment and 3 days after treatment were compared. The prognostic indicators such as mechanical ventilation time, ICU stay time, total hospital stay time, 28-day mortality rate and clinical efficacy of the two groups of patients were compared.Results:Before treatment, there were no statistically significant differences in inflammatory factors, blood gas analysis indicators, APACHE Ⅱ score and SOFA score between the two groups of patients (all P>0.05). After 3 days of treatment, the improvement degrees of APACHE Ⅱ score, SOFA score, arterial partial pressure of oxygen (PaO 2), oxygenation index (PaO 2/FiO 2), procalcitonin (PCT), interleukin-6 (IL-6), and C-reactive protein (CRP) in the sivelestat sodium group were all greater than those in the control group. The differences were all statistically significant (all P<0.05); The mechanical ventilation time [(5.31±4.12) d vs (7.17±2.32)d] and ICU stay [(6.31±3.42)d vs (8.93±5.26)d] of patients in the sivelestat sodium group were significantly shorter than those in the control group, and the differences were statistically significant (all P<0.05). There was no statistically significant difference in the 28-day mortality rate between the sivelestat sodium group [20.00%(6/30)] and the control group [43.33%(13/30)] ( P>0.05). The total effective rate of treatment in the sivelestat sodium group was significantly higher than that in the control group [80.00%(24/30) vs 56.67%(17/30)], and the difference was statistically significant (χ 2=4.167, P=0.041). Conclusions:Sivelestat sodium is helpful in improving the physiological parameters of patients with ARDS, effectively reducing the levels of inflammatory factors in the body, shortening the duration of mechanical ventilation and ICU stay, but has no significant effect on the 28-day mortality rate.

To understand the background of Escherichia coli(E.coli)carried by artificially bred sika deer and the biological characteristics of the isolated strains,such as drug resistance and pathogenicity,in April 2024,we collected 184 fresh deer fecal samples from four deer farms in Luxiang Township,Shuangyang District,Changchun City,Jilin Province,for isolation and cultivation of E.coli.The isolates were tested for drug resistance and biochemical identification with a BD PhoenixTM-100 Automated Microbiology System.The virulence genes were detected with PCR,and the strains were molecularly typed with ERIC-PCR.A total of 165 E.coli strains were isolated from 184 samples of deer feces,with an isolation rate of 89.67%.Twenty strains had a drug resistance phenotype,and the drug resistance rate was 12.12%;these strains included 15 strains of multi-drug resistant bacteria and 11 strains of ESBL-producing bacteria.Virulence gene detection indicated that the sika deer isolates carried multiple diarrhea-associated virulence genes,such as EAST-1(12.12%),eae(1.21%),stx1(7.88%),stx2(7.27%),and STa(1.82%).ERIC-PCR demonstrated that the isolates showed high polymorphism.The ESBL-producing E.coli carried by sika deer are likely to spread drug resistance in the community and livestock population.Some isolates carried multiple diarrhea-associated virulence genes,thus posing a human transmission risk.Therefore,monitoring of drug resistance and virulence genes must be strengthened,and antibiotics must be used reasonably during the breeding process to avoid excessive use and misuse.

Objective:To investigate the clinical value of laparoscopic evaluation of anato-mical position of inferior mesenteric artery (IMA), inferior mesenteric vein (IMV) and left colic artery (LCA).Methods:The prospective one-arm study was conducted. The clinical data of 229 pati-ents who underwent laparoscopic left hemicolectomy for left colon or laparoscopic radical resection of rectal cancer in The Second Affiliated Hospital of Air Force Medical University from December 2022 to December 2023 were selected. The distance between the origin point of IMA and the origin point of the first branch (L1) as well as the distance from the origin point of LCA root to the junction of LCA and IMV (L2) were measured during the operation. IMA classification, the location relation-ship of LCA and IMV junction were recorded. Observation indicators: (1) situations of enrolled patients; (2) difference analysis between L1, L2 and clinical features; (3) distribution characteristics of the location relationship between LCA and IMV in different types of IMA. Mann-Whitney U test was used for comparison of measurement data with skewed distribution between groups, Kruskal-Wallis H test was used for comparison between multiple groups, and Dunn-Bonferroni test was used for pairwise comparison. Comparison of count data between groups was performed by chi-square test. Pearson or Spearman correlation analysis was conducted for correlation of continuous variables. Results:(1) Situations of enrolled patients. A total of 229 eligible patients were screened out, including 146 males and 83 females, aged 64(range, 55-71)years. The height of 229 patients was 168(range, 160-172)cm, the weight was 65.0(55.5,71.5)kg, the body surface area was (1.68±0.17)m 2, the tumor maximum diameter was 3.0(2.5,4.0)cm. The total number of lymph nodes dissected was 19(17,21), and the number of No.253 lymph node dissected was 4(3,5). The L1 was 3.50(1.20,8.00)cm, and the L2 was 2.20(0.50,7.30)cm. There were 58, 31, 32, 71, 22, 90, 26 and 212 patients with smoking, alcohol drinking, diabetes, hypertension, coronary heart disease, neoadjuvant chemo-therapy, neoadjuvant radiotherapy and preservation of the LCA, respectively. Among 229 patients, cases with BMI <18.5 kg/m 2, 18.5-23.9 kg/m 2 and >23.9 kg/m 2 were 11, 133 and 85, respectively. There were 153 cases in pathological stage Ⅰ-Ⅱ and 76 cases in stage Ⅲ. There were 168 cases of Dixon operation, 6 cases of Miles operation and 55 cases of sigmoid colon resection. There were 135 cases of IMA type 1, 44 cases of IMA type 2, 23 cases of IMA type 3, 2 cases of IMA type 4, and 25 cases of IMA type unable to judge. (2) Difference analysis between L1, L2 and clinical features.Correlation analysis showed negative correlation between the height, body surface area and L1 ( r=-0.17, -0.15, P<0.05). The L1 was 3.20(2.68,4.00)cm for male patients and 3.60(3.00,4.20)cm for female patients, respectively, showing a significant difference between the two groups ( Z=-2.37, P<0.05). The L1 of patients with IMA type 1, 2, and 3 was 3.20(2.80,4.00)cm, 3.85(3.00,4.48)cm, and 3.20(2.50,4.30)cm, respectively, showing a significant difference among them ( H=7.54, P<0.05). Further pairwise com-parison showed that there was a significant difference in L1 between patients with IMA type 2 and those with IMA type 1 ( P<0.05). The L2 of smokers and non-smokers were 2.50(1.95,3.20)cm and 2.20(1.60,2.80)cm, respectively, showing a significant difference between the two groups ( Z=-2.24, P<0.05). (3)Distribution characteristics of the location relationship between LCA and IMV in different types of IMA. There was no significant difference in LCA distribution between the anterior and posterior positions of IMV among the three IMA types (type 1, 2, 3) ( χ2=1.63, P>0.05). Conclusions:Patients with greater height have larger body surface area and shorter L1. L1 is significantly longer in female patients than in male patients. L1 is significantly longer in patients with IMA type 2 than in those with type 1. L2 is significantly longer in smokers than in non-smokers. There was no significant difference in the distribution location between LCA and IMV among patients of IMA type 1, 2 and 3.