Objective To evaluate the clinical utility of the f-wave to QRS complex amplitude ratio(f/R ratio)in intracardiac electrogram(IC-ECG)-guided positioning of peripherally inserted central catheter(PICC)tips in patients with atrial fibrillation(AF),providing evidence to enhance clinical practice.Methods This study employed a conve-nience sampling method to enroll eligible AF patients admitted to a tertiary hospital in Suzhou from July 2023 to July 2024.During PICC placement,IC-ECG was utilized to monitor f-wave and QRS complex amplitude variations.Following successful catheterization,the f/R ratio was measured,and chest X-ray was performed to confirm the catheter tip position.The accuracy of PICC tip positioning across different f/R ratio ranges was analyzed,and the incidence of arrhythmias was recorded.A receiver operating characteristic curve was constructed to assess the diag-nostic performance of the f/R ratio in PICC tip localization.Results A total of 68 AF patients were included,with f/R ratios ranging from 20.63％to 91.24％.PICC tip positioning accuracy varied significantly across different f/R ratio ranges(P=0.006).The area under the ROC curve(AUC)for f/R ratio in PICC tip positioning was 0.784(P=0.009),with a maximum Youden index of 0.567,an optimal diagnostic threshold of 40.00％,a sensitivity of 81.7％,a speci-ficity of 75.0％,a positive predictive value of 96.1％,and a negative predictive value of 35.3％.No arrhythmias other than AF occurred during the procedure.Conclusion The f/R ratio provides reliable and safe guidance for PICC tip positioning in AF patients.An f/R ratio ≥40％is associated with higher accuracy in identifying the optimal catheter tip position.

Objective This study aimed to investigate the tumorigenic properties of MMTV-PyMT breast cancer transgenic mice at different ages(in weeks)and the changes in the composition of immune cells in the tumor microenvironment.Methods Eight groups of 4,6,8,10,12,14,16 and 18 weeks of age MMTV-PyMT female mice(FVB mice as the background)and one group of 8 weeks of FVB female mice were prepared for routine blood testing,the pathological changes of the mammary gland and lung metastases were observed by histopathological sections,and the immune cells in blood,spleen,and tumor were analyzed by flow cytometry.Results MMTV-PyMT mice showed adenular ductal lesions at 4～6 weeks of age;the ductal portion expanded to the growth boundary at 8～9 weeks of age,and then gradually broke through the glandular boundary to form early breast cancer at 8～12 weeks of age,and advanced breast cancer at 10～14 weeks of age.At 12 weeks of age,metastases were visible in the lungs of some mice,and at 14 weeks of age,the number of metastases in the lungs increased significantly.As the age of the mice increased,the number of white blood cells,neutrophils,and platelets in their blood increased gradually,while the lymphocytes and erythrocytes showed a gradual downward trend.Flow cytometry showed that with the increase in age,the proportion of T cells in the spleen and tumor gradually decreased,the MDSCs in the blood,spleen,and tumor gradually increased,and the NK cells in the tumor also gradually increased.Conclusions This study analyzed routine blood tests,pathology,and immune cells in the tissues of MMTV-PyMT mouse models of different weeks of age,providing a novel perspective on the dynamic alterations of the tumor immune microenvironment during the malignant progression of breast cancer.

Objective This study aimed to investigate the tumorigenic properties of MMTV-PyMT breast cancer transgenic mice at different ages(in weeks)and the changes in the composition of immune cells in the tumor microenvironment.Methods Eight groups of 4,6,8,10,12,14,16 and 18 weeks of age MMTV-PyMT female mice(FVB mice as the background)and one group of 8 weeks of FVB female mice were prepared for routine blood testing,the pathological changes of the mammary gland and lung metastases were observed by histopathological sections,and the immune cells in blood,spleen,and tumor were analyzed by flow cytometry.Results MMTV-PyMT mice showed adenular ductal lesions at 4～6 weeks of age;the ductal portion expanded to the growth boundary at 8～9 weeks of age,and then gradually broke through the glandular boundary to form early breast cancer at 8～12 weeks of age,and advanced breast cancer at 10～14 weeks of age.At 12 weeks of age,metastases were visible in the lungs of some mice,and at 14 weeks of age,the number of metastases in the lungs increased significantly.As the age of the mice increased,the number of white blood cells,neutrophils,and platelets in their blood increased gradually,while the lymphocytes and erythrocytes showed a gradual downward trend.Flow cytometry showed that with the increase in age,the proportion of T cells in the spleen and tumor gradually decreased,the MDSCs in the blood,spleen,and tumor gradually increased,and the NK cells in the tumor also gradually increased.Conclusions This study analyzed routine blood tests,pathology,and immune cells in the tissues of MMTV-PyMT mouse models of different weeks of age,providing a novel perspective on the dynamic alterations of the tumor immune microenvironment during the malignant progression of breast cancer.

Objective To evaluate the clinical utility of the f-wave to QRS complex amplitude ratio(f/R ratio)in intracardiac electrogram(IC-ECG)-guided positioning of peripherally inserted central catheter(PICC)tips in patients with atrial fibrillation(AF),providing evidence to enhance clinical practice.Methods This study employed a conve-nience sampling method to enroll eligible AF patients admitted to a tertiary hospital in Suzhou from July 2023 to July 2024.During PICC placement,IC-ECG was utilized to monitor f-wave and QRS complex amplitude variations.Following successful catheterization,the f/R ratio was measured,and chest X-ray was performed to confirm the catheter tip position.The accuracy of PICC tip positioning across different f/R ratio ranges was analyzed,and the incidence of arrhythmias was recorded.A receiver operating characteristic curve was constructed to assess the diag-nostic performance of the f/R ratio in PICC tip localization.Results A total of 68 AF patients were included,with f/R ratios ranging from 20.63％to 91.24％.PICC tip positioning accuracy varied significantly across different f/R ratio ranges(P=0.006).The area under the ROC curve(AUC)for f/R ratio in PICC tip positioning was 0.784(P=0.009),with a maximum Youden index of 0.567,an optimal diagnostic threshold of 40.00％,a sensitivity of 81.7％,a speci-ficity of 75.0％,a positive predictive value of 96.1％,and a negative predictive value of 35.3％.No arrhythmias other than AF occurred during the procedure.Conclusion The f/R ratio provides reliable and safe guidance for PICC tip positioning in AF patients.An f/R ratio ≥40％is associated with higher accuracy in identifying the optimal catheter tip position.

[This corrects the article DOI: 10.1016/j.apsb.2024.04.021.].

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Objective:To provide theoretical basis for strength and endurance training of waist and abdominal muscles and prevention of waist injuries in fighter pilots by exploring the muscle strength and work characteristics of the waist and abdominal flexor and extensor muscles in fighter pilots.Methods:Sixty male fighter pilots who were qualified for flight in aeromedical assessment, aged 24-46 years old, were randomly selected and divided into 24-30, 31-40, 41-46 years group. The Isomed2000 isokinetic dynamometer system was applied to measure the muscle strength and work performance of the abdominal and lumbar flexors and extensors of the fighter pilots with the angular velocities of 60°/s and 180°/s. The flexion and extension muscle peak torque, relative peak torque, flexion-extension ratio, and endurance ratio were compared among different age groups of pilots.Results:At the same angular velocity, the peak torque and relative peak torque of the lumbar and abdominal extensor muscles in fighter pilots were greater than those of the flexor muscles, with statistically significant differences ( t=7.01-9.13, all P<0.001). The peak torque and relative peak torque of the lumbar and abdominal flexor and extensor muscles significantly decreased with increasing test angular velocity ( t=13.63-17.25, all P<0.001). Under the angular velocity of 60°/s, there were no significant differences in the peak torque and relative peak torque of the flexor muscles among different age groups (both P>0.05); there were significant differences in the peak torque and relative peak torque of extensor muscles ( F=5.31, 6.61, P=0.008, 0.003) and 41-46 years groups were lower than the other 2 groups ( P=0.019, 0.003, 0.002, 0.004). Under an angular velocity of 180°/s, there were significant differences in the peak torque and relative peak torque of the waist and abdominal flexor and extensor muscles among different age groups ( F=3.82, 3.47, 3.83, 5.49, P=0.028, 0.043, 0.027, 0.008); the relative peak torque of the abdominal and lumbar flexor and extensor muscles in the 24-30 years group was higher than that in the 41-46 years group ( P=0.032, 0.006). The peak torque and the relative peak torque of the abdominal and lumbar flexor muscles in 31-40 years group were higher than those in 41-46 years group ( P=0.008, 0.013). The low qualification rate of peak torque ratio indicated the imbalance between flexor and extensor muscles and the poor endurance of abdominal and lumbar flexor and extensor muscles than that of flexor muscles. There was no statistically significant difference in the endurance ratio of the abdominal and lumbar flexor and extensor muscles among different age groups ( P>0.05). Conclusions:The balance between flexor and extensor muscles of waist and abdominal muscles should be paid more in fighter pilot′s fitness training. For the pilots older than 40 the training targeted to slow the muscles decline is necessary.

Objective To investigate the effectiveness of team-based learning(TBL)combined with research-based learning(RBL)in enhancing evidence-based nursing practice skills of undergraduate nursing interns.Methods A total of 114 undergraduate nursing students who interned in the operating room of a ⅢA hospital in Guangzhou from July 2021 to April 2022 were selected as study subjects.A randomized cluster sampling method based on a random number table was used to divide the students into a control group and a trial group.The control group received traditional teaching methods,while the trial group was taught using a combination of TBL and RBL.The two groups were compared in terms of evidence-based practice skills,critical thinking abilities,and their evaluations on the teaching methods.Results The differences in evidence-based practice skills and critical thinking abilities before and after the internship were significantly higher in the observation group compared to the control group(t=35.108,35.897;both P<0.05).Additionally,post-internship evaluation scores for the teaching methods in the trial group were significantly higher than those in the control group(t=-17.580,P<0.05).Conclusion TBL combined with RBL effectively enhances the evidence-based nursing practice skills and critical thinking abilities of undergraduate nursing interns.This approach also improves students'evaluations on the teaching methods and fosters the cultivation of excellent clinical evidence-based nursing professionals.

Objective To investigate whether a stable and reliable hyperuricemia model can be established in mice with an ICR background via a triple-modeling method(combined potassium oxazine,hypoxanthine,and 30％yeast paste),and to evaluate the effect of the positive drug febuxostat on the model.Methods A hyperuricemia model of ICR mice was established using a single drug or double-or triple-drug combinations.Serum uric acid and creatinine concentrations,xanthine oxidase(XOD)and urate oxidase(UOX)activity,and uric acid transporter(URAT)1,glucose transporter(Glut)9,anion transporter(OAT)1,and ATP-binding box subfamily G member(ABCG)2 mRNA levels were detected to evaluate whether the hyperuricemia model was formed successfully.Results The serum uric acid levels of ICR mice were not significantly changed by potassium oxazine alone,as they showed an increase but were not significantly different to those of the 30％yeast paste diet or hypoxanthine combined groups.Serum uric acid levels in the triple administration group were significantly increased at 7 days(P＜0.01),while XOD enzyme activity had increased(P＜0.01)and UOX enzyme activity decreased(P＜0.001)at the same timepoint.There were increased expression levels of URAT1 and Glut9(P＜0.05,P＜0.001),and decreased expression levels of OAT1 and ABCG2(P＜0.001).During dynamic monitoring,the blood uric acid levels of triple administration-induced ICR mice peaked at 7 days.In addition,triple administration-induced hyperuricemia in ICR mice was sensitive to the positive drug febuxostat,which caused a significant decrease in blood uric acid levels(P＜0.001).Conclusions A hyperuricemia model in ICR mice can be stably induced by triple administration for 7 days.

Objective To investigate the risk factors associated with prolonged hospitalization in patients diagnosed with diabetic foot ulcers(DFU),to develop a predictive model,and to conduct internal validation of the model.Methods The clinical data of DFU patients admitted to West China Hospital,Sichuan University between January 2012 and December 2022 were retrospectively collected.The subjects were randomly assigned to a training cohort and a validation cohort at a ratio of 7 to 3.Hospital stays longer than 75th percentile were defined as prolonged length-of-stay.A thorough analysis of the risk factors was conducted using the training cohort,which enabled the development of an accurate risk prediction model.To ensure robustness,the model was internally validated using the validation cohort.Results A total of 967 inpatients with DFU were included,among whom 245 patients were identified as having an extended length-of-stay.The training cohort consisted of 622 patients,while the validation cohort comprised 291 patients.Multivariate logistic regression analysis revealed that smoking history(odds ratio[OR]=1.67,95%confidence interval[CI],1.13 to 2.48,P=0.010),Wagner grade 3 or higher(OR=7.13,95%CI,3.68 to 13.83,P＜0.001),midfoot ulcers(OR=1.99,95%CI,1.07 to 3.72,P=0.030),posterior foot ulcers(OR=3.68,95%CI,1.83 to 7.41,P＜0.001),multisite ulcers(OR=2.91,95%CI,1.80 to 4.69,P＜0.001),wound size≥3 cm2(OR=2.00,95%CI,1.28-3.11,P=0.002),and white blood cell count(OR=1.11,95%CI,1.05 to 1.18,P＜0.001)were associated with an increased risk of prolonged length of stay.Additionally,a nomogram was constructed based on the identified risk factors.The areas under the receiver operating characteristic(ROC)curves for both the training cohort and the validation cohort were 0.782(95%CI,0.745 to 0.820)and 0.756(95%CI,0.694 to 0.818),respectively,indicating robust predictive performance.Furthermore,the calibration plot demonstrated optimal concordance between the predicted probabilities and the observed outcomes in both the training and the validation cohorts.Conclusion Smoking history,Wagner grade≥3,midfoot ulcers,posterior foot ulcers,multisite ulcers,ulcer area≥3 cm2,and elevated white blood cell count are identified as independent predictors of prolonged hospitalization.Therefore,it is imperative that clinicians conduct a comprehensive patient evaluation and implement appropriate diagnostic and therapeutic strategies to effectively shorten the length of stay for DFU patients.