Objective:To compare the application effects of upper arm autogenous arteriovenous fistula (AVF) and forearm arteriovenous graft (AVG) in maintenance hemodialysis (MHD) patients, and to analyze the factors influencing the long-term patency rate of arteriovenous fistulas in MHD patients.Methods:It was a retrospective cohort study. The data of MHD patients treated in the First Affiliated Hospital of Zhejiang University School of Medicine from January 2021 to May 2023 was collected. Participants were stratified into two groups: forearm AVG and upper arm AVF. The parameters including urea clearance index (Kt/V), serum C-reactive protein (CRP), albumin levels, access-related costs, complication rates, and long-term primary patency were compared. The end event was defined as arteriovenous fistula failure, that was, the arteriovenous fistula could not be used for dialysis puncture, or the arteriovenous fistula lost function after adequate blood flow was achieved. Kaplan-Meier survival curves with log-rank tests were employed to compare access survival, while multivariable Cox regression was used to analyze the independent associated factors of patency.Results:A total of 71 MHD patients were enrolled in this study, including 35 males, with age of (64.9±11.7) years and fistula establishment time of 30.0(17.0, 58.0) months. There were 32 cases (45.1%) in the forearm AVG group and 39 cases (54.9%) in the upper arm AVF group. Compared with the forearm AVG group, the upper arm AVF group had higher serum albumin levels [38.9 (37.0, 42.1) g/L vs. 38.0 (34.6, 40.0) g/L, Z=-2.364, P=0.018], higher pain scores [3.0(2.0, 5.0) points vs. 2.0(1.0, 3.0) points, Z=-3.012, P=0.003], and higher long-term patency rates of arteriovenous fistulas (at 3, 6, 12, and 24 months, all P<0.01), while the complication rate[61.5% (24/39) vs. 93.7% (30/32), χ2=10.015, P=0.002], the cost of the access [0 (0, 9,117.0) yuan·year -1·person -1vs. 10 380.5 (7 186.0, 30 228.5) yuan·year -1·person -1, Z=-4.094, P<0.001] were lower, and the length of the available puncture vessel segment was shorter [3.5(3.0, 5.0) cm vs. 6.5(6.0, 8.0) cm, Z=-6.477, P<0.001].The Kaplan-Meier survival analysis results showed that the primary patency rate of the upper arm AVF group was significantly higher than that of the forearm AVG group (Log-rank test, χ2=23.690, P<0.001). The multivariate Cox regression analysis results indicated that the type of fistula being forearm AVG (with upper arm AVF as reference, HR=4.907, 95% CI 1.740-13.840) and increased complications number ( HR=1.234, 95% CI 1.040-1.464) were the independent factors promoting the arteriovenous fistula failure in MHD patients. Conclusions:The type of internal fistula and the complications are the factors affecting the long-term patency rate of internal fistula in MHD patients.Upper arm AVF offers cost-effectiveness and sustained patency advantages over forearm AVG but requires careful consideration of puncture challenges and patient discomfort. Individualized access selection should balance anatomical constraints with clinical priorities.

Objective In response to the practical issues of pilot ground simulation ejection training relying on subjective evaluation,which requires high professionalism and lacks objectivity and systematicity,an objective evaluation system and method for ejection training based on pressure detection has been designed.Methods According to the rules of ejection training about posture,maneuver and time,and utilizing technologies such as pressure detection,infrared detection,and time-triggered detection,this paper designed separate modules for ejection posture detection,ejection timing detection,and comprehensive analysis and evaluation.These modules are closely integrated with the ejection training process,achieving objective evaluation of the ejection training.Results This system and method can provide a scientific and real-time objective evaluation of the posture,movements,and time in ejection training without affecting the normal organization and process.Conclusion The objective evaluation system can provide a new approach that is highly objective and easy to operate for comprehensively evaluating and enhancing the effectiveness of ejection training,as well as for scientifically conducting ejection training and assessment.

With the rapid development of aviation technology,the ability of pilots to fly successfully and safely has attracted much attention.Improving pilots'emergency evacuation capabilities is the responsibility of every aviation worker.The injury caused by pilot parachute jumping is an important issue in flight safety.During the parachute jumping process,the pilot will be subjected to various impact forces and aerodynamic forces,which can cause damage to the pilot's spine,nervous system,circulatory system,and multiple parts of the body,and even endanger lift.This article focuses on exploring the characteristics of pilot ejection parachute injuries,categorizing and summarizing them according to the location and factors of the injuries,and analyzing their protective strategies.Targeted ground ejection simulation training is conducted for pilots in different batches to improve the combat effectiveness of the armies.

Objective A new type fighter pilot's helmet comfort was investigated to provide basis for generalization and popularization.Methods A quantitative questionnaire was designed to evaluate the comfort of current helmets and new helmets by pilots of series A and B fighters,and compare the new helmets with the current helmets.Thirdly,quantitative statistics of questionnaires were carried out to analyze the pilot's opinions on current helmets and new helmets.Based on the structure and quality characteristics of current helmets and new helmets,the investigation results were analyzed and discussed.Results A total of 167 pilots from series A and B fighter aircraft participated in trial wear and questionnaire investigation of new helmets.Among them,103 pilots from series A fighters and 64 pilots from series B fighters.Compared with the pilot's current helmet,the new helmet is lightweight and comfortable.Among them,92.2%of the pilots of the series A believe that the new helmet is more comfortable than the current helmet,and 90.3%of pilots think it is necessary to replace the current helmet with the new helmet.90.6%of the pilots of the Series B think the new helmet is more comfortable than the current helmet,and 92.2%of pilots think it is necessary to replace the current helmet with the new helmet.Conclusion The new fighter pilot's helmet is light and comfortable,and has been widely praised by pilots.The research results provide data support and decision-making basis for its universalization and popularization.

Aim Based on coronary CT-fractional flow reserve(CT-FFR)combined with machine learning methods,a nomogram prediction model for coronary in-stent restenosis(ISR)was developed to assess the risk of ISR.Methods Retrospective analysis was performed on patients who underwent re-examination after PCI at our hospital from January 2022 to January 2025.According to the exclusion criteria,a total of 210 patients were enrolled,including 100 cases of ISR and 110 cases of non-ISR.The dataset was randomly divided into training and test sets at a 7∶3 ratio.Af-ter univariate analysis to screen potential predictors,LASSO regression was applied to identify feature variables with non-ze-ro coefficients.Subsequently,three machine learning(ML)algorithms including random forest(RF),support vector machine(SVM),and extreme gradient boosting(XGB)were used to rank the importance of the significant factors.The intersection of the top 10 variables from each algorithm was used as input for bidirectional stepwise multivariate Logistic re-gression.An ISR risk score was then constructed and visualized using a nomogram.Results A total of 14 predictive factors were identified through LASSO regression,including diastolic blood pressure,C-reactive protein,triglycerides(TG),N-terminal pro-brain natriuretic peptide(NT-proBNP),low density lipoprotein cholesterol(LDLC),minimum stent diameter＜3 mm,systolic blood pressure,△CT-FFR,CT-FFR,interleukin-6(IL-6),body mass index,glycosylated hemoglobin(HbA1c),history of hypertension,and high density lipoprotein cholesterol(HDLC).Following stepwise screening using three ML algorithms and Logistic regression,six independent risk factors for ISR were identified:elevated△CT-FFR,IL-6,NT-proBNP,TG and CT-FFR values,and minimum stent diameter＜3 mm.The area under the curve for the training set and test set were 0.995(95％CI:0.989～1.000)and 0.965(95％CI:0.927～1.000),respectively.Decision curve analysis demonstrated high net benefit across threshold probabilities of 0～1.00 in the training set and 0～0.92 in the test set.The nomogram integrating these six predictors exhibited high accuracy and clinical utility.Con-clusion The ISR nomogram prediction model based on LASSO-ML combined with CT-FFR technology has high accuracy and clinical utility for ISR.

Objective:To explore the application value of right-opening single flap valvuloplasty based on tubular stomach in gastrointestinal reconstruction after laparoscopic proximal gastrectomy.Method:Use a linear cutting stapler to make a parallel curve from the angle of the stomach to the junction of the gastric fundus to remove the lesser curvature of the stomach, and detach the gastric body about 5 cm away from the tumor to create a tubular stomach. Use a marker pen to draw a C-shaped seromuscular flap area with a width of 2.5 cm and a height of 3.5 cm 1.5 cm below the residual stomach closure nail, and create a free muscle flap in the gap between the plasma muscle layer and the submucosal layer. Make a transverse incision of 3 cm at the lower edge of the mucosal bed, and intermittently suture the entire lower edge of the gastric wall with 3 stitches. Under laparoscopy, use 4-0 barbed wire to suture the 1 cm wide muscular layer at the top of the tubular stomach and the posterior wall of the esophagus about 5 cm away from the esophageal stump with 3 stitches. Push the upper end of the tubular stomach into the mediastinum, and then tighten the barbed wire to ensure a tight fit between the stomach and the posterior wall of the esophagus. Use an ultrasonic scalpel to remove the esophageal stump, suture the entire posterior wall of the esophagus with the gastric mucosa, and use barbed wire to suture the anterior wall from left to right. The anastomotic site is completely covered with a free muscle flap, and the barbed line is used to continuously suture the muscle flap along the C-shaped line to the gastric pulp muscle layer at the edge of the mucosal bed, embedding the anastomotic site and completing the reconstruction of the digestive tract.Results:Clinical data of 23 patients (18 from the First Affiliated Hospital of Wenzhou Medical University and 5 from the Quzhou Hospital affiliated with Wenzhou Medical University) who underwent laparoscopic proximal gastrectomy, tubular gastroesophageal anastomosis, and pure manual right flap reconstruction surgery for esophagogastric junction adenocarcinoma and proximal gastric cancer from October 2023 to August 2024. There were 15 males and 8 females, with an age of (65.3±7.7) years, the BMI was (22.9±2.8) kg/m 2. All patients in the group successfully completed the surgery, with a surgery time of (218.5±38.1) minutes, including (73.5±19.2) minutes for anastomosis, intraoperative blood loss of (64.5±15.4) ml, postoperative passage of gas on (3.4±0.5) days, first consumption of liquid food after surgery of (3.9±1.1) days, and postoperative hospital stay of (9.1±0.8) days. One patient developed anastomotic stenosis (grade I) after surgery, presenting with mild swallowing obstruction, which returned to normal after dietary adjustment, and there were no cases of secondary surgery. The median follow-up time for the entire group was 4.0 (0.7-7.0) months, during which there were no deaths or tumor recurrence or metastasis, no complications such as anastomotic stenosis or gastric emptying disorders, and no complaints of acid reflux or heartburn. At one month of postoperative follow-up, the reflux symptom index (RSI) score was (3.1±2.9) points, and at three months, the RSI score was (2.4±1.4) points. Conclusions:The application of right-opening single flap valvuloplasty based on tubular stomach for gastrointestinal reconstruction after laparoscopic proximal gastrectomy is safe,feasible,and has satisfactory short-term efficacy.

Aim Based on coronary CT-fractional flow reserve(CT-FFR)combined with machine learning methods,a nomogram prediction model for coronary in-stent restenosis(ISR)was developed to assess the risk of ISR.Methods Retrospective analysis was performed on patients who underwent re-examination after PCI at our hospital from January 2022 to January 2025.According to the exclusion criteria,a total of 210 patients were enrolled,including 100 cases of ISR and 110 cases of non-ISR.The dataset was randomly divided into training and test sets at a 7∶3 ratio.Af-ter univariate analysis to screen potential predictors,LASSO regression was applied to identify feature variables with non-ze-ro coefficients.Subsequently,three machine learning(ML)algorithms including random forest(RF),support vector machine(SVM),and extreme gradient boosting(XGB)were used to rank the importance of the significant factors.The intersection of the top 10 variables from each algorithm was used as input for bidirectional stepwise multivariate Logistic re-gression.An ISR risk score was then constructed and visualized using a nomogram.Results A total of 14 predictive factors were identified through LASSO regression,including diastolic blood pressure,C-reactive protein,triglycerides(TG),N-terminal pro-brain natriuretic peptide(NT-proBNP),low density lipoprotein cholesterol(LDLC),minimum stent diameter＜3 mm,systolic blood pressure,△CT-FFR,CT-FFR,interleukin-6(IL-6),body mass index,glycosylated hemoglobin(HbA1c),history of hypertension,and high density lipoprotein cholesterol(HDLC).Following stepwise screening using three ML algorithms and Logistic regression,six independent risk factors for ISR were identified:elevated△CT-FFR,IL-6,NT-proBNP,TG and CT-FFR values,and minimum stent diameter＜3 mm.The area under the curve for the training set and test set were 0.995(95％CI:0.989～1.000)and 0.965(95％CI:0.927～1.000),respectively.Decision curve analysis demonstrated high net benefit across threshold probabilities of 0～1.00 in the training set and 0～0.92 in the test set.The nomogram integrating these six predictors exhibited high accuracy and clinical utility.Con-clusion The ISR nomogram prediction model based on LASSO-ML combined with CT-FFR technology has high accuracy and clinical utility for ISR.

Objective:To explore the application value of right-opening single flap valvuloplasty based on tubular stomach in gastrointestinal reconstruction after laparoscopic proximal gastrectomy.Method:Use a linear cutting stapler to make a parallel curve from the angle of the stomach to the junction of the gastric fundus to remove the lesser curvature of the stomach, and detach the gastric body about 5 cm away from the tumor to create a tubular stomach. Use a marker pen to draw a C-shaped seromuscular flap area with a width of 2.5 cm and a height of 3.5 cm 1.5 cm below the residual stomach closure nail, and create a free muscle flap in the gap between the plasma muscle layer and the submucosal layer. Make a transverse incision of 3 cm at the lower edge of the mucosal bed, and intermittently suture the entire lower edge of the gastric wall with 3 stitches. Under laparoscopy, use 4-0 barbed wire to suture the 1 cm wide muscular layer at the top of the tubular stomach and the posterior wall of the esophagus about 5 cm away from the esophageal stump with 3 stitches. Push the upper end of the tubular stomach into the mediastinum, and then tighten the barbed wire to ensure a tight fit between the stomach and the posterior wall of the esophagus. Use an ultrasonic scalpel to remove the esophageal stump, suture the entire posterior wall of the esophagus with the gastric mucosa, and use barbed wire to suture the anterior wall from left to right. The anastomotic site is completely covered with a free muscle flap, and the barbed line is used to continuously suture the muscle flap along the C-shaped line to the gastric pulp muscle layer at the edge of the mucosal bed, embedding the anastomotic site and completing the reconstruction of the digestive tract.Results:Clinical data of 23 patients (18 from the First Affiliated Hospital of Wenzhou Medical University and 5 from the Quzhou Hospital affiliated with Wenzhou Medical University) who underwent laparoscopic proximal gastrectomy, tubular gastroesophageal anastomosis, and pure manual right flap reconstruction surgery for esophagogastric junction adenocarcinoma and proximal gastric cancer from October 2023 to August 2024. There were 15 males and 8 females, with an age of (65.3±7.7) years, the BMI was (22.9±2.8) kg/m 2. All patients in the group successfully completed the surgery, with a surgery time of (218.5±38.1) minutes, including (73.5±19.2) minutes for anastomosis, intraoperative blood loss of (64.5±15.4) ml, postoperative passage of gas on (3.4±0.5) days, first consumption of liquid food after surgery of (3.9±1.1) days, and postoperative hospital stay of (9.1±0.8) days. One patient developed anastomotic stenosis (grade I) after surgery, presenting with mild swallowing obstruction, which returned to normal after dietary adjustment, and there were no cases of secondary surgery. The median follow-up time for the entire group was 4.0 (0.7-7.0) months, during which there were no deaths or tumor recurrence or metastasis, no complications such as anastomotic stenosis or gastric emptying disorders, and no complaints of acid reflux or heartburn. At one month of postoperative follow-up, the reflux symptom index (RSI) score was (3.1±2.9) points, and at three months, the RSI score was (2.4±1.4) points. Conclusions:The application of right-opening single flap valvuloplasty based on tubular stomach for gastrointestinal reconstruction after laparoscopic proximal gastrectomy is safe,feasible,and has satisfactory short-term efficacy.

Objective:To compare the application effects of upper arm autogenous arteriovenous fistula (AVF) and forearm arteriovenous graft (AVG) in maintenance hemodialysis (MHD) patients, and to analyze the factors influencing the long-term patency rate of arteriovenous fistulas in MHD patients.Methods:It was a retrospective cohort study. The data of MHD patients treated in the First Affiliated Hospital of Zhejiang University School of Medicine from January 2021 to May 2023 was collected. Participants were stratified into two groups: forearm AVG and upper arm AVF. The parameters including urea clearance index (Kt/V), serum C-reactive protein (CRP), albumin levels, access-related costs, complication rates, and long-term primary patency were compared. The end event was defined as arteriovenous fistula failure, that was, the arteriovenous fistula could not be used for dialysis puncture, or the arteriovenous fistula lost function after adequate blood flow was achieved. Kaplan-Meier survival curves with log-rank tests were employed to compare access survival, while multivariable Cox regression was used to analyze the independent associated factors of patency.Results:A total of 71 MHD patients were enrolled in this study, including 35 males, with age of (64.9±11.7) years and fistula establishment time of 30.0(17.0, 58.0) months. There were 32 cases (45.1%) in the forearm AVG group and 39 cases (54.9%) in the upper arm AVF group. Compared with the forearm AVG group, the upper arm AVF group had higher serum albumin levels [38.9 (37.0, 42.1) g/L vs. 38.0 (34.6, 40.0) g/L, Z=-2.364, P=0.018], higher pain scores [3.0(2.0, 5.0) points vs. 2.0(1.0, 3.0) points, Z=-3.012, P=0.003], and higher long-term patency rates of arteriovenous fistulas (at 3, 6, 12, and 24 months, all P<0.01), while the complication rate[61.5% (24/39) vs. 93.7% (30/32), χ2=10.015, P=0.002], the cost of the access [0 (0, 9,117.0) yuan·year -1·person -1vs. 10 380.5 (7 186.0, 30 228.5) yuan·year -1·person -1, Z=-4.094, P<0.001] were lower, and the length of the available puncture vessel segment was shorter [3.5(3.0, 5.0) cm vs. 6.5(6.0, 8.0) cm, Z=-6.477, P<0.001].The Kaplan-Meier survival analysis results showed that the primary patency rate of the upper arm AVF group was significantly higher than that of the forearm AVG group (Log-rank test, χ2=23.690, P<0.001). The multivariate Cox regression analysis results indicated that the type of fistula being forearm AVG (with upper arm AVF as reference, HR=4.907, 95% CI 1.740-13.840) and increased complications number ( HR=1.234, 95% CI 1.040-1.464) were the independent factors promoting the arteriovenous fistula failure in MHD patients. Conclusions:The type of internal fistula and the complications are the factors affecting the long-term patency rate of internal fistula in MHD patients.Upper arm AVF offers cost-effectiveness and sustained patency advantages over forearm AVG but requires careful consideration of puncture challenges and patient discomfort. Individualized access selection should balance anatomical constraints with clinical priorities.