Objective To analyze the MRI artifact of the inner ear structure in patients with peripheral vertigo acquired by using 3D fast imaging employing steady state acquisition(3D FIESTA-C)and 3D fast spin echo(3D-Cube T2).Methods Data of 63 patients with peripheral vertigo treated in the Department of Otolaryngology,The First Affiliated Hospital of Xi'an Jiaotong University,from October 2023 to June 2024 were filtered for analysis.The patients consisted of 16 males and 47 females,aged 18 to 60 years old.Two senior radiologists independently evaluated the quality of the acquired images through the two MRI sequences.Kappa test was used to evaluate the consistency of the two radiologists' subjective judgments,and Wilcoxon signed-rank test was used to compare the image quality between each sequence.The accuracy of 3D FIESTA-C,3D-Cube T2 and combination of the two sequences was calculated in the presentation of inner ear structure.Results The overall image quality of 3D-Cube T2 was better than that of 3D FIESTA-C(Z=-11.670,P＜0.001),and the accuracy of 3D FIESTA-C combined with 3D-Cube T2 was superior to that of each sequence in demonstrating the semicircular canals.The demonstration accuracy of horizontal semicircular canal among three scan protocols was statistically different(P＜0.001).Conclusion 3D FIESTA-C has the advantage in detecting horizontal semicircular canal,and 3D-Cube T2 always provides high quality images of upper semicircular canal.Compared with each scanning sequence,3D FIESTA-C combined with 3D-Cube T2 can effectively avoid misdiagnosis or missed diagnosis of semicircular canal structures in the patients with peripheral vertigo.

Objective:To explore the protocol for handgrip exercise stress echocardiography by comparing different maximal voluntary contraction（MVC）handgrip groups with bicycle exercise stress.Methods:Forty-one healthy volunteers were enrolled prospectively from June to October 2024 in Tangdu Hospital and utilized a color Doppler echocardiography system，supine cycle ergometer，and handgrip dynamometer to collect echocardiographic data at baseline，during handgrip exercises at 20%（3 min），30%（3 min），and 40%（2 min）of MVC，and spine bicycle exercise stress at peak. Parameters measured included left ventricular ejection fraction（EF），stroke volume（SV），cardiac output（CO），mitral inflow E-wave and A-wave velocities，lateral and septal mitral annular e' velocities，E/A and E/e' ratios，global longitudinal strain（GLS），left atrial reservoir strain（LAS R），conduit strain（LAS CD），and contractile strain（LAS CT）. The non-invasive myocardial work indices were also assessed，including global work index（GWI），global constructive work（GCW），global wasted work（GWW），and global work efficiency（GWE）. Statistical analyses were performed using repeated measures analysis of variance，with corrected paired t-test for comparisons between two exercise stress states. Results:Compared with the baseline state，heart rate，blood pressure，CO、GWI、GCW、GWW and LAS CT gradually increased，while EF、E/A、GLS、GWE、LAS R and LAS CD gradually decreased under 20%，30% and 40% of MVC states. The changes were most obvious at 40% of MVC state，which was selected for the handgrip exercise stress echocardiography protocol.Compared with the peak of bicycle exercise，at 40% of MVC，heart rate was significantly lower［（81.2 ± 9.7）bpm vs.（164.6 ± 11.3）bpm， P<0.05）］，systolic blood pressure was slightly lower［（152.9 ± 13.2）mmHg vs.（165.1 ± 20.4）mmHg， P<0.05］，diastolic blood pressure was higher［（96.0 ± 9.5）mmHg vs.（89.5 ± 10.9）mmHg， P<0.05］，GLS was lower［（19.1 ± 1.5）% vs.（23.5 ± 1.7）%， P<0.05］，GWI was similar［（2 254.2 ± 417.3）mmHg% vs.（2 227.5 ± 389.0）mmHg%， P>0.05］，but GWE was higher［（95.3 ± 2.0）% vs.（93.7 ± 2.0）%， P<0.05］，and LAS R was lower［（39.4 ± 4.2）% vs.（43.9 ± 4.1）%， P<0.05］. Conclusions:The 40% of MVC lasting 2 min can cause the most significant handgrip-related changes in cardiac function and can be used as the standard protocol for handgrip exercise stress echocardiography. Handgrip stress exercise can cause significant changes in cardiac systole，diastole，and work performance，showing different characteristics compared with bicycle exercise stress.

Objective:To assess the clinical utility of vector flow mapping（VFM）for evaluating left ventricular wall shear stress（WSS）in individuals with non-obstructive hypertrophic cardiomyopathy（nHCM）.Methods:Forty patients with non-obstructive HCM（nHCM）and 46 healthy volunteers in Tangdu Hospital of Air Force Medical University from May 2020 to September 2023 were enrolled prospectively in this study. The left ventricular WSS of each of 18 segments was measured and analyzed by VFM during rapid filling phase（T1），slow filling phase（T2），isovolumetric contraction phase（T3）and rapid ejection phase（T4）.Results:① WSS decreased gradually from basal to apical segments in control group，while there was no such change pattern in nHCM group. ② Diastolic phase：When compared to the control group，the nHCM group demonstrated significantly increased WSS across all segments of the inferoseptal regions，the basal anteroseptal segment，and the middle and apical inferior segments during the T1 stage. Additionally，at the T2 stage，the WSS was significantly higher in the nHCM group across all segments of the inferoseptal and anteroseptal regions，the basal anterolateral segment，and the apical inferolateral and anterior segments（all P<0.05）. Conversely，during the T1 stage，the basal anterolateral segment，basal inferolateral segment，and the middle and apical anteroseptal segments，as well as during the T2 stage，the basal and middle inferior segments，exhibited lower WSS values compared to the control group，with these differences being statistically significant（all P<0.05）. ③Systolic Phase：During the T3 stage，the WSS values in all segments of the anteroseptal and anterolateral regions，as well as the apical inferior and anterior segments，were significantly elevated in the nHCM group compared to the control group（all P<0.05）.At the T4 stage，WSS in each segment of the inferolateral and inferior regions，as well as the basal and middle anterior segments，was significantly elevated in the nHCM group compared to the control group（all P<0.01）. Conversely，during the same stage，the WSS values in the basal inferolateral segment，the basal and middle anterolateral segments，and the basal and middle anteroseptal segments were significantly lower in the nHCM group than in the control group，with all differences reaching statistical significance（all P<0.01）.Regarding global WSS，the left ventricular global WSS in the nHCM group was significantly higher than that in the control group at both the T2 and T3 stages（all P<0.001）. Furthermore，the global WSS at the T3 stage was negatively correlated with left ventricular end-systolic volume，end-diastolic volume，and left ventricular stroke volume（ r=-0.226， P=0.036； r=-0.345， P=0.001； r=-0.303， P=0.005）. Conclusions:Significant differences in WSS are observed between patients with nHCM and control groups at various phases. WSS may serve as an early indicator of changes in cardiac function in nHCM patients.

Kirsten rat sarcoma viral oncogene homolog(KRAS)protein inhibitors are a promising class of thera-peutics,but research on molecules that effectively penetrate the blood-brain barrier(BBB)remains limited,which is crucial for treating central nervous system(CNS)malignancies.Although molecular generation models have recently advanced drug discovery,they often overlook the complexity of bio-logical and chemical factors,leaving room for improvement.In this study,we present a structure-constrained molecular generation workflow designed to optimize lead compounds for both drug effi-cacy and drug absorption properties.Our approach utilizes a variational autoencoder(VAE)generative model integrated with reinforcement learning for multi-objective optimization.This method specifically aims to enhance BBB permeability(BBBp)while maintaining high-affinity substructures of KRAS in-hibitors.To support this,we incorporate a specialized KRAS BBB predictor based on active learning and an affinity predictor employing comparative learning models.Additionally,we introduce two novel metrics,the knowledge-integrated reproduction score(KIRS)and the composite diversity score(CDS),to assess structural performance and biological relevance.Retrospective validation with KRAS inhibitors,AMG510 and MRTX849,demonstrates the framework's effectiveness in optimizing BBBp and highlights its potential for real-world drug development applications.This study provides a robust framework for accelerating the structural enhancement of lead compounds,advancing the drug development process across diverse targets.

Kirsten rat sarcoma viral oncogene homolog (KRAS) protein inhibitors are a promising class of therapeutics, but research on molecules that effectively penetrate the blood-brain barrier (BBB) remains limited, which is crucial for treating central nervous system (CNS) malignancies. Although molecular generation models have recently advanced drug discovery, they often overlook the complexity of biological and chemical factors, leaving room for improvement. In this study, we present a structure-constrained molecular generation workflow designed to optimize lead compounds for both drug efficacy and drug absorption properties. Our approach utilizes a variational autoencoder (VAE) generative model integrated with reinforcement learning for multi-objective optimization. This method specifically aims to enhance BBB permeability (BBBp) while maintaining high-affinity substructures of KRAS inhibitors. To support this, we incorporate a specialized KRAS BBB predictor based on active learning and an affinity predictor employing comparative learning models. Additionally, we introduce two novel metrics, the knowledge-integrated reproduction score (KIRS) and the composite diversity score (CDS), to assess structural performance and biological relevance. Retrospective validation with KRAS inhibitors, AMG510 and MRTX849, demonstrates the framework's effectiveness in optimizing BBBp and highlights its potential for real-world drug development applications. This study provides a robust framework for accelerating the structural enhancement of lead compounds, advancing the drug development process across diverse targets.

BACKGROUND:Cervical disc herniation can cause pain in the neck and shoulder area,as well as radiating pain in the upper limbs.The incidence rate is increasing year by year and tends to affect younger individuals.Fully understanding the biomechanical characteristics of the cervical spine in adolescents is of great significance for preventing and delaying the onset of cervical disc herniation in this age group. OBJECTIVE:To reconstruct cervical spine models for both healthy adolescents and adolescent patients with cervical disc herniation utilizing finite element analysis techniques,to analyze the motion range of the C1-T1 cervical vertebrae as well as the biomechanical characteristics of the annulus fibrosus,nucleus pulposus,endplates,and the cartilage of the small joints. METHODS:A normal adolescent's cervical spine and an adolescent patient with cervical disc herniation were selected in this study.The continuous scan cervical spine CT raw image data were imported into Mimics 21.0 in DICOM format.The C1-T1 vertebrae were reconstructed separately.Subsequently,the established models were imported into the 3-Matic software for disc reconstruction.The perfected models were then imported into Hypermesh software for meshing of the vertebrae,nucleus pulposus,annulus fibrosus,and ligaments,creating valid geometric models.After assigning material properties,the final models were imported into ABAQUS software to observe the joint motion range of the C1-C7 cervical vertebrae segments under different conditions,and to analyze the biomechanical characteristics of the annulus fibrosus,nucleus pulposus,endplates,and small joint cartilage of each cervical spine segment. RESULTS AND CONCLUSION:(1)In six different conditions,the joint motion range of the C1 vertebra in the cervical spine models of both normal adolescent and adolescent patient with cervical disc herniation was higher than that of the other vertebrae.Additionally,the joint motion range of each cervical spine segment in normal adolescent was greater than that in adolescent patient with cervical disc herniation.(2)In the cervical spine model of normal adolescent,the maximum stress values in the annulus fibrosus and nucleus pulposus were found on the left side during C2-3 flexion conditions(0.43 MPa and 0.17 MPa,respectively).In the cervical spine model of adolescent patient with cervical disc herniation,the maximum stress values were found on the left side during C7-T1 flexion conditions(0.54 MPa and 0.18 MPa,respectively).(3)In the cervical spine model of normal adolescent,the maximum stress value on the endplate was found on the left side of the upper endplate of C3 during flexion conditions(1.46 MPa).In the model of adolescent patient with cervical disc herniation,the maximum stress value on the endplate was found on the left side of the lower endplate of C7 during flexion conditions(1.32 MPa).(4)In the cervical spine model of normal adolescent,the maximum stress value in the small joint cartilage was found in the C2-3 left rotation conditions(0.98 MPa).In adolescent patient with cervical disc herniation,the stress in the small joint cartilage significantly increased under different conditions,especially in C1-2,with the maximum stress found during left flexion(3.50 MPa).(5)It is concluded that compared to normal adolescent,adolescent patient with cervical disc herniation exhibits altered cervical curvature and a decrease in overall joint motion range in the cervical spine.In adolescent with cervical disc herniation,there is a significant increase in stress on the annulus fibrosus,nucleus pulposus,and endplates in the C7-T1 segment.The stress on the left articular cartilage of the C1-2 is notable.Abnormal cervical curvature may be the primary factor causing these stress changes.

Objective:To investigate the effect of protein tyrosine phosphatase D(PTPRD)demethylation on the proliferation,migration,and chemoresistance of gastric cancer(GC)cells through the phosphatidyl inositol 3 kinase/protein kinase B/mammalian target of rapamycin(PI3K/Akt/mTOR)pathway.Methods:The gastric cancer MKN-74 and MKN-45 cells,as well as human gastric mucosal epithelial GES-1 cells,GES-1 were cultured in vitro and PTPRD expression was detected.MKN-45 cells and their drug-resistant variant MKN-45/5-FU cells were routinely cultured and transfected with various vectors:PTPRD empty vector(NC group,NC/5-FU group),PTPRD overexpressing adenovirus(PTPRD group,PTPRD/5-FU group),shRNA empty vector(sh-NC group,sh-NC/5-FU group),shRNA PTPRD lentivirus(sh-PTPRD group,sh-PTPRD/5-FU group),and PTPRD overexpressing adenovirus+10 μmol/L 740Y-P treatment(PTPRD+740Y-P group,PTPRD+740Y-P/5-FU group).MTT assay and wound healing assay were used to assess cell proliferation and migration.Cell autophagy levels were assessed using autophagy assay,and the expression of epithelial-mesenchymal transition(EMT)and PI3K/Akt/mTOR pathway related proteins was detected using western blot(WB).MKN-45 cells were treated with 0,2.5,5,10,20 and 40 μmol/L 5-aza solutions,and the PTPRD mRNA expression and cell proliferation in MKN-45 cells were detected using qPCR and MTT assays.Results:PTPRD mRNA and protein were significantly downregulated in gastric cancer cells(P<0.05).Compared with the MKN-45 group,the numbers of autophagosomes and autophagosomes,as well as the protein expression of PTPRD,E-cadherin,and BAX significantly increased in the PTPRD group(all P<0.05),while cell proliferation,migration rate,and protein expression of p-PI3K,vimentin,p-Akt,and p-mTOR decreased significantly(all P<0.05);However,in the sh-PTPRD group,cell proliferation activity,migration rate,and protein expression of p-PI3K,vimentin,p-Akt,and p-mTOR increased notably,while the quantity of autophagosomes,autophagosomes,and protein expression of PTPRD,E-cadherin,and BAX decreased(all P<0.05).Compared with the PTPRD group,the PTPRD+740Y-P group showed an increase in cell proliferation activity,migration rate,protein expression of p-PI3K,vimentin,p-Akt,and p-mTOR(all P<0.05),and a decrease in number of autophagosomes,autophagosomes,and protein expression of PTPRD,E-cadherin,and BAX(all P<0.05).With the increase of 5-aza concentration,the mRNA expression of PTPRD in MKN-45 cells increased(P<0.05),while the cell proliferation activity decreased(P<0.05).Compared with the MKN-45/5-FU group,the cell migration rate and proliferation activity decreased in PTPRD/5-FU group,while the sh-PTPRD/5-FU group showed an increase in cell migration rate and proliferation activity(all P<0.05).Compared with the PTPRD/5-FU group,the PTPRD+740Y-P/5-FU group showed an increase in cell migration rate and proliferation activity(all P<0.05).Conclusion:PTPRD is downregulated in GC cells,and its demethylation may inhibit proliferation and migration of GC cells and enhance chemosensitivity by suppressing the PI3K/Akt/mTOR pathway.

Objective:To explore the protocol for handgrip exercise stress echocardiography by comparing different maximal voluntary contraction（MVC）handgrip groups with bicycle exercise stress.Methods:Forty-one healthy volunteers were enrolled prospectively from June to October 2024 in Tangdu Hospital and utilized a color Doppler echocardiography system，supine cycle ergometer，and handgrip dynamometer to collect echocardiographic data at baseline，during handgrip exercises at 20%（3 min），30%（3 min），and 40%（2 min）of MVC，and spine bicycle exercise stress at peak. Parameters measured included left ventricular ejection fraction（EF），stroke volume（SV），cardiac output（CO），mitral inflow E-wave and A-wave velocities，lateral and septal mitral annular e' velocities，E/A and E/e' ratios，global longitudinal strain（GLS），left atrial reservoir strain（LAS R），conduit strain（LAS CD），and contractile strain（LAS CT）. The non-invasive myocardial work indices were also assessed，including global work index（GWI），global constructive work（GCW），global wasted work（GWW），and global work efficiency（GWE）. Statistical analyses were performed using repeated measures analysis of variance，with corrected paired t-test for comparisons between two exercise stress states. Results:Compared with the baseline state，heart rate，blood pressure，CO、GWI、GCW、GWW and LAS CT gradually increased，while EF、E/A、GLS、GWE、LAS R and LAS CD gradually decreased under 20%，30% and 40% of MVC states. The changes were most obvious at 40% of MVC state，which was selected for the handgrip exercise stress echocardiography protocol.Compared with the peak of bicycle exercise，at 40% of MVC，heart rate was significantly lower［（81.2 ± 9.7）bpm vs.（164.6 ± 11.3）bpm， P<0.05）］，systolic blood pressure was slightly lower［（152.9 ± 13.2）mmHg vs.（165.1 ± 20.4）mmHg， P<0.05］，diastolic blood pressure was higher［（96.0 ± 9.5）mmHg vs.（89.5 ± 10.9）mmHg， P<0.05］，GLS was lower［（19.1 ± 1.5）% vs.（23.5 ± 1.7）%， P<0.05］，GWI was similar［（2 254.2 ± 417.3）mmHg% vs.（2 227.5 ± 389.0）mmHg%， P>0.05］，but GWE was higher［（95.3 ± 2.0）% vs.（93.7 ± 2.0）%， P<0.05］，and LAS R was lower［（39.4 ± 4.2）% vs.（43.9 ± 4.1）%， P<0.05］. Conclusions:The 40% of MVC lasting 2 min can cause the most significant handgrip-related changes in cardiac function and can be used as the standard protocol for handgrip exercise stress echocardiography. Handgrip stress exercise can cause significant changes in cardiac systole，diastole，and work performance，showing different characteristics compared with bicycle exercise stress.

Objective:To assess the clinical utility of vector flow mapping（VFM）for evaluating left ventricular wall shear stress（WSS）in individuals with non-obstructive hypertrophic cardiomyopathy（nHCM）.Methods:Forty patients with non-obstructive HCM（nHCM）and 46 healthy volunteers in Tangdu Hospital of Air Force Medical University from May 2020 to September 2023 were enrolled prospectively in this study. The left ventricular WSS of each of 18 segments was measured and analyzed by VFM during rapid filling phase（T1），slow filling phase（T2），isovolumetric contraction phase（T3）and rapid ejection phase（T4）.Results:① WSS decreased gradually from basal to apical segments in control group，while there was no such change pattern in nHCM group. ② Diastolic phase：When compared to the control group，the nHCM group demonstrated significantly increased WSS across all segments of the inferoseptal regions，the basal anteroseptal segment，and the middle and apical inferior segments during the T1 stage. Additionally，at the T2 stage，the WSS was significantly higher in the nHCM group across all segments of the inferoseptal and anteroseptal regions，the basal anterolateral segment，and the apical inferolateral and anterior segments（all P<0.05）. Conversely，during the T1 stage，the basal anterolateral segment，basal inferolateral segment，and the middle and apical anteroseptal segments，as well as during the T2 stage，the basal and middle inferior segments，exhibited lower WSS values compared to the control group，with these differences being statistically significant（all P<0.05）. ③Systolic Phase：During the T3 stage，the WSS values in all segments of the anteroseptal and anterolateral regions，as well as the apical inferior and anterior segments，were significantly elevated in the nHCM group compared to the control group（all P<0.05）.At the T4 stage，WSS in each segment of the inferolateral and inferior regions，as well as the basal and middle anterior segments，was significantly elevated in the nHCM group compared to the control group（all P<0.01）. Conversely，during the same stage，the WSS values in the basal inferolateral segment，the basal and middle anterolateral segments，and the basal and middle anteroseptal segments were significantly lower in the nHCM group than in the control group，with all differences reaching statistical significance（all P<0.01）.Regarding global WSS，the left ventricular global WSS in the nHCM group was significantly higher than that in the control group at both the T2 and T3 stages（all P<0.001）. Furthermore，the global WSS at the T3 stage was negatively correlated with left ventricular end-systolic volume，end-diastolic volume，and left ventricular stroke volume（ r=-0.226， P=0.036； r=-0.345， P=0.001； r=-0.303， P=0.005）. Conclusions:Significant differences in WSS are observed between patients with nHCM and control groups at various phases. WSS may serve as an early indicator of changes in cardiac function in nHCM patients.

Objective To analyze the MRI artifact of the inner ear structure in patients with peripheral vertigo acquired by using 3D fast imaging employing steady state acquisition(3D FIESTA-C)and 3D fast spin echo(3D-Cube T2).Methods Data of 63 patients with peripheral vertigo treated in the Department of Otolaryngology,The First Affiliated Hospital of Xi'an Jiaotong University,from October 2023 to June 2024 were filtered for analysis.The patients consisted of 16 males and 47 females,aged 18 to 60 years old.Two senior radiologists independently evaluated the quality of the acquired images through the two MRI sequences.Kappa test was used to evaluate the consistency of the two radiologists' subjective judgments,and Wilcoxon signed-rank test was used to compare the image quality between each sequence.The accuracy of 3D FIESTA-C,3D-Cube T2 and combination of the two sequences was calculated in the presentation of inner ear structure.Results The overall image quality of 3D-Cube T2 was better than that of 3D FIESTA-C(Z=-11.670,P＜0.001),and the accuracy of 3D FIESTA-C combined with 3D-Cube T2 was superior to that of each sequence in demonstrating the semicircular canals.The demonstration accuracy of horizontal semicircular canal among three scan protocols was statistically different(P＜0.001).Conclusion 3D FIESTA-C has the advantage in detecting horizontal semicircular canal,and 3D-Cube T2 always provides high quality images of upper semicircular canal.Compared with each scanning sequence,3D FIESTA-C combined with 3D-Cube T2 can effectively avoid misdiagnosis or missed diagnosis of semicircular canal structures in the patients with peripheral vertigo.