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.

ObjectiveGastric hemorrhage is one of the most common and life-threatening emergencies of the upper digestive tract. Early identification and continuous monitoring are essential for reducing rebleeding rates and mortality, particularly within the critical early hours after onset. Although endoscopy and radiological imaging can accurately localize bleeding sites, these approaches are invasive, resource-intensive, and unsuitable for continuous bedside monitoring. Electrical impedance tomography (EIT), as a noninvasive and radiation-free functional imaging technique, offers real-time visualization of conductivity distribution and has the potential for detecting intragastric bleeding based on the electrical contrast between blood and surrounding gastric tissues. In this study, a three-dimensional gastric EIT (3D-gEIT) framework is proposed to achieve noninvasive, real-time, and dynamic monitoring of gastric hemorrhage, with emphasis on spatial localization and quantitative volume assessment. MethodsA three-dimensional upper-abdominal simulation model incorporating the stomach, gastric wall, gastric contents, and surrounding tissues was established. Three electrode configurations, namely the dual layer ring, the four layer staggered ring, and the opposed dual plane array, were designed and systematically compared to evaluate their influence on depth sensitivity and spatial resolution. Based on the Tikhonov-Noser hybrid regularization scheme, a region-clustering constraint was introduced to develop the TK-Noser-RCC algorithm. This approach aggregates spatially adjacent elements with similar conductivity variations, thereby enhancing structural continuity and suppressing isolated noise artifacts. To validate the proposed framework, an upper-abdominal physical phantom was constructed using agar to simulate background tissue conductivity. Hemispherical high-conductivity inclusions with volumes ranging from 10 ml to 50 ml were attached to the inner gastric wall to mimic localized bleeding under different gastric filling states. Boundary voltages were acquired under a 120 kHz excitation current and reconstructed using the TK-Noser-RCC algorithm. Furthermore, an in vivo animal experiment was performed using a porcine model with adult-scale abdominal dimensions. A total of 100 ml of autologous blood was injected incrementally into the stomach to simulate progressive gastric hemorrhage, and time-difference EIT reconstruction was conducted at each injection stage to assess the dynamic system response under physiological conditions. ResultsSimulation results demonstrated that the opposed dual-plane electrode array achieved superior depth sensitivity distribution and spatial resolution. For a 40 ml hemorrhage model, the average ICC and SSIM improved by 55.9% and 38.8% compared with the dual-layer ring configuration, and by 64.0% and 39.5% compared with the four-layer staggered configuration. The proposed region-clustering constraint significantly enhanced reconstruction stability. Under added Gaussian noise of 40 dB and 30 dB, ICC values remained approximately 0.85, indicating effective artifact suppression and preservation of boundary integrity. In physical phantom experiments, reconstructed hemorrhage volumes increased approximately linearly with the preset hemispherical volumes, and the reconstructed high-conductivity regions closely matched the actual bleeding locations. Both empty-stomach and full-stomach conditions were evaluated, demonstrating that the opposed dual-plane configuration maintained stable imaging performance across varying gastric contents. In the animal experiment, reconstructed low-impedance regions expanded progressively with increasing injected blood volume. The spatial localization of the hemorrhage remained stable throughout the procedure, and no significant artifacts were observed. Quantitative analysis showed that reconstructed volume and average conductivity variation exhibited an approximately linear growth trend with injected blood volume, confirming the sensitivity of the system to dynamic intragastric conductivity changes. ConclusionThe proposed 3D-gEIT framework enables quantitative reconstruction of gastric hemorrhage volume and spatial distribution with improved depth sensitivity, structural continuity, and noise robustness compared with conventional EIT approaches. By integrating optimized electrode configuration and a region-clustering-constrained reconstruction algorithm, the system provides stable dynamic monitoring under both controlled phantom conditions and in vivo physiological environments. This method offers a noninvasive, real-time, and low-cost imaging strategy for early diagnosis, postoperative monitoring, and bedside surveillance of gastric bleeding.

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 investigate the impact of red blood cell suspension infusion across various perioperative periods on patients with valvular heart disease. Methods The patients with valvular heart disease admitted to Tianjin Chest Hospital from 2018 to 2020 were selected. Based on the timing of perioperative red cell suspension infusion, patients were categorized into three groups: a group 1 receiving intraoperative red cell suspension infusion, a group 2 receiving red cell suspension infusion within 24 hours after entering the ICU, and a group 3 receiving red cell suspension infusion at both time points. The laboratory results, perioperative blood component infusion volume, and other relevant parameters were retrospectively analyzed. After propensity score matching, the differences in different variables among the three groups were compared. Results After propensity score matching, 102 patients were enrolled, including 52 males and 50 females, with an average age of (61.74±10.58) years. There were 34 patients in each group. The preoperative hemoglobin (Hb) value of the group 2 was significantly higher than that of the group 1 and the group 3, and the amount of red cell suspension and autoblood transfusion was the lowest (P<0.05). Group 1 had the highest postoperative Hb, as well as the highest Hb and hematocrit (HCT) levels within 24 hours post-surgery (P<0.05). The group 1 had the lowest plasma, platelet and cryoprecipitate infusion volumes, and the shortest cardiopulmonary bypass time, aortic occlusion time, postoperative ICU stay and hospital stay, and the least blood loss and total drainage volume (P<0.05). The difference between postoperative and preoperative Hb (△Hb1) was highest in group 1 (P<0.05). Conclusion For patients with valvular heart disease, intraoperative-only infusion of red blood cell suspension is associated with a better prognosis at discharge and during follow-up.

Objectives:To investigate the association between the triglyceride-glucose(TyG)index and risk of non-alcoholic fatty liver disease(NAFLD)in young and middle-aged(<60 years)adults.Methods:From June 2006 to October 2007,47 675 employees of Kailuan Group with no liver disease were selected as the study objects.Based on the TyG index quartile,participants were divided into Q1 group(TyG index≤8.08,n=11 924),Q2 group(8.0836.46,n=11 919),the association between TyG index,cum-TyG and cumulative exposure time and the risk of NAFLD was analyzed.Results:The average age of the study population was(44.3±8.7)years,36 345 participants were males(76.23%).During a median follow-up period of 11.55(7.28,13.89)years,4 635(9.72%)participants developed new-onset NAFLD.After adjusting for confounders,cox regression analysis showed that compared with the Q1 group,the HR(95%CI)for NAFLD in the Q2 to Q4 groups were 1.328(1.191-1.480),1.591(1.430-1.770),and 2.106(1.861-2.384),respectively,Ptrend<0.001.Compared with the cum-Q1 group,the HR(95%CI)for NAFLD in the cum-Q2 to cum-Q4 groups were 1.571(1.426-1.730),2.123(1.935-2.330)and 2.593(2.367-2.840),respectively,Ptrend<0.001.Compared with the TyG index for 0 year,the HR(95%CI)of NAFLD for 2,4 and 6 years was 1.333(1.196-1.486),1.879(1.690-2.088)and 3.184(2.860-3.545),respectively,Ptrend<0.001.Conclusions:Increased TyG index is an independent risk factor for the new-onset NAFLD in young and middle-aged population.

Objective:To investigate the effects of different BMI classifications on rehabilitation outcomes and complications after total knee arthroplasty(TKA).Methods:Clinical data of 88 patients who underwent TKA in our hospital from January 2022 to June 2024 were retrospectively analyzed.According to the World Health Organization(WHO)BMI standards,patients were divided into normal weight group(18.5 ≤BMI＜24.9 kg/m2),overweight group(25.0≤BMI＜29.9 kg/m2),mild obesity group(30.0≤BMI＜34.9 kg/m2),and severe obesity group(BMI≥35.0 kg/m2).Baseline data,operation time,intraoperative blood loss,hospital stay,postoperative knee function scores,pain scores,range of motion(ROM),and incidence of complications were compared among groups.Results:With the increase of BMI,operation time was prolonged,intraoperative blood loss increased,and hospital stay extended,with statistically significant differences(P＜0.05).At 3-month and 6-month follow-ups,Knee Society Score(KSS)and Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC)showed that functional recovery decreased with increasing BMI(P＜0.05).Regarding postoperative complications,the incidence of poor incision healing,infection,and deep vein thrombosis(DVT)in the obese groups was significantly higher than in the normal weight and overweight groups(P＜0.05).Conclusion:BMI is an important factor affecting rehabilitation outcomes and complications after TKA.Patients with high BMI have slower functional recovery and higher complication rates.For patients with high BMI,preoperative weight loss and individualized rehabilitation programs should be considered to improve TKA prognosis.

Aim To investigate the expression of or-ganic anion transporting polypeptide 4C1(Oatp4c1)-P-glycoprotein(P-gp)in the kidneys of obese mice in-duced by high-fat diet(HFD),and its impact on the pharmacokinetic changes of digoxin.Methods C57BL/6 mice were randomly divided into the Chow group and the HFD group.Body weight and blood glu-cose were recorded weekly.After successful model es-tablishment,digoxin was intraperitoneally injected,and blood was collected at different time points.Part of the blood samples was used for LC-MS/MS detection,and the other part was used for the detection of other bio-chemical indicators.After 16 weeks,the organs were removed and weighed.HE and immunohistochemical staining was used to observe the renal pathology and the expression of Villin,a marker of proximal tubules.Western blot and qPCR were combined to detect the expression of Villin,Oatp4c1 and P-gp.Results In the HFD group,body weight and blood glucose in-creased significantly.The blood concentration of digox-in rose,the area under the curve increased,and the half-life was prolonged.The proximal tubular epithelial cells shed,and the protein expression of Villin,Oatp4c1 and P-gp decreased significantly.Conclu-sions The down-regulation of Oatp4c1-P-gp expres-sion in the kidneys of HFD mice leads to an increase in the blood concentration of digoxin and a decrease in re-nal clearance.

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.

Objective To design a high altitude adaptive oxygen generator for the crews to alleviate their high altitude reaction in high altitude environment and meet their requirements for oxygen supply.Methods A high altitude adaptive oxygen generator based on the mature pressure swing adsorption oxygen production method was designed with the key technologies of discharge capacity compensation of air compression pump and airway fusion of molecular sieve tower,which had the components of molecular sieve tower,air compression pump,controller,cooling fan,cooler,solenoid valve,regulator,flow meter and etc.Trials were carried out at the simulated altitude and field plateau environment so as to verify the high altitude adaptive performance of the oxygen generator developed.Results The trial results showed the oxygen generator met the desired objectives and the requirements for oxygen volume fraction in GJB 2799-1996 General specification for medical oxygen generator using molecular sieve method.Conclusion The oxygen generartor provides oxygen supply effectively for vehicle operators in plateau environments or the ones rushing into the plateau.[Chinese Medical Equipment Journal,2025,46(4):29-34]

Aim To investigate the protective effect of Vaccarin(Va)on epithelial-mesenchymal transition(EMT)in renal fibrosis model mice through regulating STAT3,and the underlying mechanism.Methods Left ureter ligation was used to establish a mouse model of unilateral ureteral obstruction(UUO);human kid-ney tubular epithelial(HK2)cells were induced to differentiate by transforming growth factor-β(TGF-β)in vitro.HE and Masson staining were used to observe the morphological changes of renal tissue;kits were used to detect the levels of BUN,Cr,IL-1β and IL-7 in mouse serum;CCK-8 was used to detect the effect of Va on the viability of HK2 cells;RT-PCR was used to detect the levels of inflammatory factors in HK2 cells;Western blot was used to detect the expression of STAT3,p-STAT3,E-cadherin,and α-SMA proteins in renal tissue and HK2 cells;to further investigate the regulation of Va on STAT3,JAK/STAT3 pathway acti-vator RO8191 was used to treat TGF-β-induced HK2 cells,and functional loss was detected.Results Va improved the pathological damage in UUO mice,inhibi-ted the levels of BUN,Cr and inflammatory factors;Va inhibited the phosphorylation of STAT3,upregulated E-cadherin,and downregulated α-SMA protein expres-sion;RO8191 counteracted the inhibitory effect of Va on the phosphorylation of STAT3.Conclusions Va inhibits the phosphorylation of STAT3 and the release of inflammatory factors,improves EMT,thus exerting an anti-renal fibrosis effect.