Objective To evaluate the short-term efficacy of transcatheter aortic valve replacement (TAVR) using Venus A-Plus valve delivery system in patients with severe aortic stenosis. Methods The clinical data of patients undergoing TAVR in our hospital from August 2018 to March 2022 were collected and they were divided into a Venus A-Plus and a Venus A group according to the type of valve delivery system used. The perioperative data of the two groups were compared. Results A total of 121 patients were included, including 70 patients in the Venus A-Plus group [45 males and 25 females with a mean age of (67.81±6.62) years], and 51 patients in the Venus A group [33 males and 18 females with a mean age of (68.25±7.01) years]. All patients underwent TAVR, and the postoperative hemodynamic features (left ventricular ejection fraction, mean cross-valve pressure difference, peak flow rate) were significantly improved (P<0.05). There was no statistical difference in surgical success rate, all-cause mortality, conversion to thorax opening, valve-in-valve placement, moderate or above perivalvular regurgitation, new left bundle branch block or new right bundle branch block between the two groups (P>0.05). Conclusion TAVR with Venus A-Plus valve delivery system in patients with severe aortic stenosis shows comparable efficacy to the first-generation Venus A system and is satisfactory, safe and reliable.

Objective: To investigate the associations between childhood obesity and performance of six minute walk test (6MWT), providing evidence for exercise tolerance assessment and exercise intervention strategies for children and adolescents. Methods: From March 2021 to December 2023, a cohort study was conducted among students recruited from a primary and secondary school in Chongqing, a total of 709 valid samples were included. The 6MWT was used to assess exercise tolerance, with vital signs measured before and after the test. Anthropometric indicators, including height, weight, and waist circumference, were measured using standardized procedures. Generalized additive models (GAM) and restricted cubic spline (RCS) regression were employed to analyze the nonlinear relationships between obesity related indicators and six minute walk distance (6MWD). Results: The mean 6MWD of participants was (602.59±70.73)m. GAM showed that after adjusting for confounding factors, body mass index (BMI) and weight had non linear relationships with 6MWD [effective degrees of freedom were 1.55 and 7.13 respectively], and overweight/obesity was associated with a decrease in 6MWD ( β =-18.65) (all P <0.01). Further RCS regression analysis showed that both BMI and weight showed an "inverted U shaped" non linear relationship with 6MWD in the overall population and sex stratified subgroups; the 6MWD of females was lower than that of males, and it showed a significant downward trend with the increase of BMI or weight (all P <0.05). Conclusion Body weight and BMI in children and adolescents have an important impact on 6MWD, and obesity in children and adolescents is markedly associated with decline in exercise tolerance.

Objective To explore the value of 3D printing technology in transcatheter aortic valve replacement(TAVR)for bicuspid aortic stenosis.Methods We retrospectively analyzed the clinical data of patients who underwent TAVR for bicuspid aortic stenosis at the Department of Cardiac Surgery of the Second Hospital of Hebei Medical University between January 2020 and January 2023.Seven-ty patients were divided into 3D printing and non-3D printing groups of 35 each,based on whether or not 3D printing technology was applied,and the perioperative clinical data of the two groups were compared.Results The patients' postoperative symptoms signifi-cantly improved compared with those before the operation,and the left ventricular ejection fraction increased to varying degrees.Compared with the non-3D printing group,the operation time,X-ray irradiation time.and transvalvular time in the 3D printing group were signifi-cantly shortened,and the probabilities of the occurrence of postoperative"flap-to-flap"implantation and conduction block were signifi-cantly reduced,with statistically significant differences(P＜0.05).There was no statistically significant difference(P＞0.05)in the inci-dence of moderate and above perivalvular leakage,valve displacement,or conversion to thoracotomy between the two groups after surgery.Conclusion 3D printing technology can effectively guide the TAVR treatment of bicuspid aortic stenosis.While significantly shortening the operation time,it can effectively increase the success rate of TAVR and reduce the risk of adverse events,providing a new approach for the transcatheter treatment of bicuspid aortic stenosis.

To understand the pathogenicity and drug resistance of swine-derived E.coli and its bio-logical characteristics in some areas in Hebei,E.coli was isolated and identified from diarrheal fe-ces of piglets collected from swine farms,and the isolated strains were subjected to drug sensitivity test,detection of the ability to form biofilm,pathogenicity test,virulence gene test,drug resistance gene test,and identification of phylogenetic subgroups.The results showed that a total of 35 patho-genic E.coli strains were isolated from the feces of diarrheic piglets,and most of the isolates were multidrug-resistant,and were resistant to at least three antibiotics,including amoxicillin(88.57％),ampicillin(88.57％),doxycycline(88.75％),sulfisoxazole(77.17％),lincomycin(100％),and chloramphenicol(100％);the isolates were severely resistant.The isolates all carried virulence genes,with a total of five virulence genes detected,namely,EAST1(77.14％),eaeA(17.14％),stx2e(5.71％),LT(2.86％),and STb(2.86％),and the isolates also carried multi-re-sistance genes,with a total of five virulence genes detected,namely,bla TEM-1(65.71％),bla CTX-M(20.00％),tetA(82.86％),tetB(14.29％),aadA2(17.14％),aac(6')-Ib(14.29％),qnrS(17.14％),sul 1(40.00％),sul2(34.29％),and floR(60.00％);the phylogenetic grouping showed that the isolates had a high proportion of group B1 and group A;and all 35 isolates showed differ-ent pathogenicity after infection of mice.This study provides a reference for the selection of effec-tive therapeutic drugs and the development of prevention and control programs for swine-origin pathogenic E.coli in Hebei Province.

Microvascular invasion is one of the critical factors influencing the prognosis of patients with hepatocellular carcinoma.Accurate preoperative prediction for its occurrence holds pivotal significance for the formulation of clinical individualized treatment decisions.Traditional diagnosis primarily relies on the evaluation of postoperative histopathological results,which exhibits a certain degree of lag.However,the emergence of radiomics features and biomarkers offers new insights for the preoperative prediction of mi-crovascular invasion.The preoperative prediction model based on radiomics and biomarkers is capable of precisely analyzing and efficiently predicting the occurrence risk of microvascular invasion from both macro-scopic imaging features and microscopic molecular levels,thereby providing multi-dimensional and precise scientific evidence for clinical decision-making.

Objective To explore the value of 3D printing technology in transcatheter aortic valve replacement(TAVR)for bicuspid aortic stenosis.Methods We retrospectively analyzed the clinical data of patients who underwent TAVR for bicuspid aortic stenosis at the Department of Cardiac Surgery of the Second Hospital of Hebei Medical University between January 2020 and January 2023.Seven-ty patients were divided into 3D printing and non-3D printing groups of 35 each,based on whether or not 3D printing technology was applied,and the perioperative clinical data of the two groups were compared.Results The patients' postoperative symptoms signifi-cantly improved compared with those before the operation,and the left ventricular ejection fraction increased to varying degrees.Compared with the non-3D printing group,the operation time,X-ray irradiation time.and transvalvular time in the 3D printing group were signifi-cantly shortened,and the probabilities of the occurrence of postoperative"flap-to-flap"implantation and conduction block were signifi-cantly reduced,with statistically significant differences(P＜0.05).There was no statistically significant difference(P＞0.05)in the inci-dence of moderate and above perivalvular leakage,valve displacement,or conversion to thoracotomy between the two groups after surgery.Conclusion 3D printing technology can effectively guide the TAVR treatment of bicuspid aortic stenosis.While significantly shortening the operation time,it can effectively increase the success rate of TAVR and reduce the risk of adverse events,providing a new approach for the transcatheter treatment of bicuspid aortic stenosis.

Objective:To reveal the coupling mechanism of beam temporal profile and tissue oxygen content on radical kinetics, further explain the potential biological basis of the FLASH effect, and provide a reference for beam optimization and treatment planning design of FLASH radiotherapy (FLASH-RT).Methods:TOPAS-nBio v3.0 was used to simulate the physical and chemical processes of electron beams in water, and a full-scale kinetic model was established covering the generation, diffusion, reaction, and quenching of free radicals such as hydroxyl radical (·OH) and hydrated electrons (e aq-). Under different beam temporal profiles (single pulse, multi-pulses, continuous wave irradiation) and different oxygen concentration conditions, the evolution dynamics of free radicals were systematically simulated. At the same time, the data on e aq- content were obtained by experimental measurement of laser absorption spectroscopy to verify the accuracy of the model prediction. Results:The changing trend of e aq- concentration measured in the experiment was highly consistent with the simulation result, verifying the reliability of the constructed model. The beam time structure had a significant impact on the peak value and duration of free radical concentration. The single-pulse structure can cause the free radicals to rapidly increase and then quickly quench in a short time, while the continuous or long-pulse structure can cause the radical concentration to remain at a high level for a long time. The evolution of ·OH was not sensitive to the oxygen environment, while e aq- are greatly affected by the oxygen environment. The scavenging efficiency of free radicals in a hypoxic environment was significantly decreased, leading to an enhanced accumulation of oxidative damage to biological macromolecules. The lifespan of e aq- in an oxygen-rich environment decreased rapidly. Conclusions:Radical kinetics are regulated by both the beam temporal profile and oxygen content. FLASH-RT can utilize single-pulse or multi-pulses intervals to form periodic windows, reducing normal tissue damage by efficiently scavenging free radicals through antioxidants, while free radicals in tumor tissues continuously accumulate and amplify damage, thus generating a selective protective effect.

Objective:This study aims to analyze the performance of five automatic cell type annotation methods in single cell RNA sequencing (scRNA-seq) data.Methods:Simulated data were generated using the Splatter package in R language, taking into account two data characteristics: the number of cells and the number of genes. The actual data came from the GSE10245 scRNA seq dataset of non-small cell lung cancer in Gene Expression Omnibus (GEO) database, the data had been pre-processed and batch effects had been eliminated. The automatic cell type recognition (ACTINN) of neural networks, the single-cell type annotation method based on deep learning (scDeepSort), the reference batch transcriptome annotation scRNA seq R-package (SingleR), the cross platform and cross species scRNA seq data classifier (SingleCellNet), and the cross scRNA seq dataset projection (scMap-cell) were implemented using the Tensorflow library in Python. The performance evaluation indicators for cell type annotation included accuracy (ACC), F1-score, and Matthews correlation coefficient (MCC). Each method was validated using ten fold cross validation, and the average value was taken after 50 repeated runs for performance comparison between methods. The Dunnett's t-test in the DescTools package of R language was used for multiple comparisons between ACTINN and other four methods. Results:Under 12 different scenarios (3 levels of cell numbers × 4 levels of gene numbers), simulated data analysis showed that compared with scDeepSort, SingleR, SingleCellNet, and scMap-cell, the percentage increase in ACC value of ACTINN ranged from 3.31% to 14.59%, 1.38% to 13.03%, 12.98% to 25.25%, and 20.72% to 29.62%, respectively; the range of F1 score improvement percentages were 2.75% - 22.74%, 2.46% - 23.68%, 5.07% - 27.47%, and 10.27% - 31.47%, respectively; the percentage increase ranges for MCC values were 3.42% - 9.75%, 2.26% - 7.61%, 5.41% - 11.11%, and 8.27% - 15.22%, respectively. Actual data analysis showed that the ACC value of ACTINN was 81.0%, which was increased by 2.1%, 5.2%, 7.9%, and 8.9% compared with the above four methods, respectively; the F1-score value was 80.5%, which was increased by 2.3%, 5.9%, 2.4%, and 6.0%, respectively; the MCC value was 83.3%, which was increased by 0.9%, 2.5%, 3.4%, and 11.2%, respectively. The results of Dunnett's t-test showed that the difference was not statistically significant in ACC values between scDeepSort and ACTINN ( P = 0.821), in F1-score values between scDeepSort and ACTINN ( P = 0.498), and in MCC values between scDeepSort, SingleCellNet and ACTINN ( P = 0.904, 0.134). However, the differences were statistically significant in other multiple comparisons ( P < 0.05). Conclusions:ACTINN and scDeepSort have good performance in cell type annotation, with ACTINN showing outstanding performance and SingleR showing robust performance, while SingleCellNet and scMap-cell have relatively limited performance. This suggests that self-attention mechanism algorithm based on Transformer framework is expected to promote further development of automatic cell annotation methods.

Objective:To evaluate the effectiveness of anti-G straining maneuver (AGSM) in pilots by surface electromyography (sEMG), and to explore the relationships between characteristics of sEMG and anti-G endurance in pilots.Methods:Thirty-eight male high-performance fighter pilots who completed the human centrifuge test at the Air Force Medical Center were selected. Among them, 25 completed the 8.0 G for 10 s anti-G endurance test and 13 completed the 9.0 G for 10 s anti-G endurance test. The sEMG tester was used to keep track of the changes of sEMG in rectus abdominis, rectus femoris, anterior tibial and gastrocnemius muscles while pilots were engaged in AGSM. The anti-G endurance was evaluated according to the changes of visual fields and consciousness. The pilots were divided into 3 groups: the good vision and consciousness group, peripheral visual field narrowing group and endurance endpoint group. The differences in the integral electromyogram (iEMG), mean power frequency (MPF) and muscle input rates between the 3 groups were investigated.Results:A total of 25 pilots completed the 8.0 G for 10 s anti-G endurance test. Among them, 8 (32.0%) were in the good vision and consciousness group, 13 (52.0%) in the peripheral visual field narrowing group and 4 (16.0%) reached the endurance endpoint. Among the 13 pilots who completed the 9.0 G for 10 s anti-G endurance test, 3 (23.1%) were in the good vision and consciousness group, 6 (46.1%) in the peripheral visual field narrowing group, and 4 (30.8%) in the endurance endpoint group. The results of sEMG showed that the iEMG values of the anterior tibialis muscle in pilots under the 9.0 G for 10 s load were significantly different across endurance groups ( H=7.54, P=0.023), and that the iEMG values of the tibialis anterior muscle in the good vision and consciousness group were higher than those in the endurance endpoint group ( P=0.036). The negative slopes of MPF for the rectus abdominis, rectus femoris, anterior tibialis, and gastrocnemius muscles were higher in the good vision and consciousness group than in the other 2 groups, but the differences were not statistically significant ( P>0.05). During the 8.0 G for 10 s anti-G endurance test, there were significant differences in lower limb muscle contribution rates between the 3 groups ( F=4.19, P=0.029). The endurance endpoint group exhibited a lower contribution rate than the good vision and consciousness group ( P=0.025). During the 9.0 G for 10 s anti-G endurance test, there were significant differences in tibialis anterior muscle contribution rates between the 3 groups ( F=4.16, P=0.049). The endurance endpoint group demonstrated a lower contribution rate than the good vision and consciousness group ( P=0.049). Conclusions:The full and balanced activation of abdominal muscles and lower limb muscles, especially the effective mobilization of calf muscles, plays a pivotal role in improving pilots′ AGSM efficiency in high G environments.