OBJECTIVE: To investigate the impact of bone mass and volume of low-density zones beneath the tibial plateau on the maximum von Mises stresses experienced by the cartilage and meniscus in the knee joint. METHODS: The study included one healthy adult volunteer, from whom CT scans were obtained, and one patient diagnosed with knee osteoarthrisis (KOA), for whom X-ray films were acquired. A static model of the knee joint featuring a low-density zone was established based on a normal knee model. In the finite element analysis, axial loads of 1 000 N and 1 800 N were applied to the weight-bearing region of the upper surface of the femoral head for model validation and subsequent finite element studies, respectively. The maximum von Mises stresses in the femoral cartilage, as well as the medial and lateral tibial cartilage and menisci, were observed, and the stress percentage of the medial and lateral components were concurrently analyzed. Additionally, HE staining, as well as alkaline magenta staining, were performed on the pathological specimens of patients with KOA in various low-density regions. RESULTS: The results of model validation indicated that the model was consistent with normal anatomical structures and correlated with previous calculations documented in the literature. Static analysis revealed that the maximum von Mises stress in the medial component of the normal knee was the lowest and increased with the advancement of the hypointensity zone. In contrast, the lateral component exhibited an opposing trend, with the maximum von Mises stress in the lateral component being the highest and decreasing as the hypointensity zone progressed. Additionally, the medial component experienced an increasing proportion of stress within the overall knee joint. HE staining demonstrated that the chondrocyte layer progressively deteriorated and may even disappear as the hypointensity zone expanded. Furthermore, alkaline magenta staining indicated that the severity of microfractures in the trabecular bone increased concurrently with the expansion of the hypointensity zone. CONCLUSION The presence of subtalar plateau low-density zone may aggravate joint degeneration. In clinical practice, it is necessary to pay attention to the changes in the subtalar plateau low-density zone and actively take effective measures to strengthen the bone status of the subtalar plateau low-density zone and restore the complete biomechanical function of the knee joint, in order to slow down or reverse the progression of osteoarthritis.
Humans ; Finite Element Analysis ; Knee Joint/physiology* ; Tibia/anatomy & histology* ; Cartilage, Articular/physiology* ; Menisci, Tibial/physiopathology* ; Tomography, X-Ray Computed ; Osteoarthritis, Knee/diagnostic imaging* ; Weight-Bearing ; Bone Density ; Adult ; Stress, Mechanical ; Male ; Middle Aged ; Biomechanical Phenomena ; Female

Thoracic aortic aneurysm (TAA) significantly endangers the lives of individuals with Marfan syndrome (MFS), yet the intricacies of their biomechanical origins remain elusive. Our investigation delves into the pivotal role of hemodynamic disturbance in the pathogenesis of TAA, with a particular emphasis on the mechanistic contributions of the mammalian target of rapamycin (mTOR) signaling cascade. We uncovered that activation of the mTOR complex 1 (mTORC1) within smooth muscle cells, instigated by the oscillatory wall shear stress (OSS) that stems from disturbed flow (DF), is a catalyst for TAA progression. This revelation was corroborated through both an MFS mouse model (Fbn1 ^+/C1039G) and clinical MFS specimens. Crucially, our research demonstrates a direct linkage between the activation of the mTORC1 pathway and the intensity in OSS. Therapeutic administration of rapamycin suppresses mTORC1 activity, leading to the attenuation of aberrant SMC behavior, reduced inflammatory infiltration, and restoration of extracellular matrix integrity-collectively decelerating TAA advancement in our mouse model. These insights posit the mTORC1 axis as a strategic target for intervention, offering a novel approach to manage TAAs in MFS and potentially pave insights for current treatment paradigms.

Thoracic aortic aneurysm(TAA)significantly endangers the lives of individuals with Marfan syndrome(MFS),yet the intricacies of their biomechanical origins remain elusive.Our investigation delves into the pivotal role of hemodynamic disturbance in the pathogenesis of TAA,with a particular emphasis on the mechanistic contributions of the mammalian target of rapamycin(mTOR)signaling cascade.We un-covered that activation of the mTOR complex 1(mTORC1)within smooth muscle cells,instigated by the oscillatory wall shear stress(OSS)that stems from disturbed flow(DF),is a catalyst for TAA progression.This revelation was corroborated through both an MFS mouse model(Fbn1+/C1039G)and clinical MFS specimens.Crucially,our research demonstrates a direct linkage between the activation of the mTORC1 pathway and the intensity in OSS.Therapeutic administration of rapamycin suppresses mTORC1 activity,leading to the attenuation of aberrant SMC behavior,reduced inflammatory infiltration,and restoration of extracellular matrix integrity—collectively decelerating TAA advancement in our mouse model.These insights posit the mTORC1 axis as a strategic target for intervention,offering a novel approach to manage TAAs in MFS and potentially pave insights for current treatment paradigms.

Objective To propose a lead attention network-based ST-T change recognition algorithm to detect ECG ST-T changes accurately.Methods Firstly,heartbeat signals were extracted through R-wave localization,and a 12-lead heartbeat matrix was generated by correlation-based screening and merging to realize data augmentation.Secondly,a lead attention module was constructed by combining depthwise convolution(DWConv)with the channel attention squeeze-and-excitation block(SE-block)structure to perceive the differences in ST-T status among electrocardiogram leads.Thirdly,the mapping output by two independent attention modules was fused and splicing with the original signal residual was carried out,so that attention information extraction and original information transfer were enhanced effectively.Finally,SE-ResNet was used as the backbone network to extract signal features to complete the classification and identification of ST-T changes.To validate the recognition performance of the proposed algorithm for ST-T changes in ECG,the 12-lead ECG data of 97 472 patients containing different ECG rhythms were collected for ablation and comparison experiments at the First Affiliated Hospital of Army Medical University.Results The proposed algorithm achieved an AUC of 0.965 with a sensitivity of 90.51%,specificity of 90.23%,positive predictive value of 89.24%and overall accuracy of 90.36%on an independent test set.Comparative analysis demonstrated superior performance to four benchmark architectures,including VGG16,ResNet18,MobileNetV3-Small and ShuffleNet,in terms of both classification accuracy and computational efficiency.Conclusion The algorithm designed can accurately detect ST-T changes and can be used for wearable ECG automatic analysis to assist in the early warning of cardiovascular diseases in both acute and chronic patients and highland residents.[Chinese Medical Equipment Journal,2025,46(7):1-11]

Objective To propose a lead attention network-based ST-T change recognition algorithm to detect ECG ST-T changes accurately.Methods Firstly,heartbeat signals were extracted through R-wave localization,and a 12-lead heartbeat matrix was generated by correlation-based screening and merging to realize data augmentation.Secondly,a lead attention module was constructed by combining depthwise convolution(DWConv)with the channel attention squeeze-and-excitation block(SE-block)structure to perceive the differences in ST-T status among electrocardiogram leads.Thirdly,the mapping output by two independent attention modules was fused and splicing with the original signal residual was carried out,so that attention information extraction and original information transfer were enhanced effectively.Finally,SE-ResNet was used as the backbone network to extract signal features to complete the classification and identification of ST-T changes.To validate the recognition performance of the proposed algorithm for ST-T changes in ECG,the 12-lead ECG data of 97 472 patients containing different ECG rhythms were collected for ablation and comparison experiments at the First Affiliated Hospital of Army Medical University.Results The proposed algorithm achieved an AUC of 0.965 with a sensitivity of 90.51%,specificity of 90.23%,positive predictive value of 89.24%and overall accuracy of 90.36%on an independent test set.Comparative analysis demonstrated superior performance to four benchmark architectures,including VGG16,ResNet18,MobileNetV3-Small and ShuffleNet,in terms of both classification accuracy and computational efficiency.Conclusion The algorithm designed can accurately detect ST-T changes and can be used for wearable ECG automatic analysis to assist in the early warning of cardiovascular diseases in both acute and chronic patients and highland residents.[Chinese Medical Equipment Journal,2025,46(7):1-11]

OBJECTIVE: To explore characteristics, management strategies and preventive measures of fusion device displacement after oblique lateral interbody fusion (OLIF) in treating lumbar lesions. METHODS: The clinical data of 12 patients with fusion device displacement after OLIF for lumbar lesions in 4 medical centers from October 2014 to December 2018 were retrospectively analyzed, including 4 males and 8 females, aged from 53 to 81 years old;2 patients with lumbar disc degeneration, 4 patients with lumbar spinal stenosis, 3 patients with lumbar degenerative spondylolisthesis and 3 patients with lumbar degenerative kyphosis;preoperative dual-energy X-ray bone mineral density (BMD) was detected in 1 patient with T-value > -1 SD, 5 patients with T-value >-1~-2.5 SD, and 6 patients with T-value <-2.5 SD;9 patients with single-segment fusion, 1 patient with 2-segment fusion, and 2 patients with 3-segment fusion;standalone OLIF was performed in 9 patients and OLIF combined with posterior pedicle screws in 3 patients. Visual analogue scale (VAS) and Oswestry disability index (ODI) were used to evaluate low back pain and lumbar function recovery at the time of fusion graft displacement and at the latest follow-up, respectively. In addition, according to imaging results during follow-up, the fusion device subsidence or redisplacement, loosening or fracture of internal fixation, and interbody fusion were observed, and the changes in the height of interbody space on the segment with fusion device displacement were measured and compared. RESULTS: There were no necrosis or infection in skin incision of 10 patients after reoperation, and 12 patients were followed up for 12 to 48 months. VAS for low back pain decreased from 3 to 8 points at the time of fusion device displacement to 0 to 2 points at the latest follow-up. ODI recovered from 31% to 51% at the time of fusion transfer to 5% to 13% at the latest follow-up. There was no loosening or fracture of the pedicle screw system during follow-up. All 11 patients with bone grafting with fusion apparatus had fusion apparatus subsidence and no further displacement of fusion apparatus. The vertebral space height recovered from 9.0 to 12.7 mm at the time of fusion graft displacement to 8.0 to 11.8 mm at the latest follow-up. Interbody fusion was obtained in all patients except 1 with no imaging results at the latest follow-up. CONCLUSION OLIF could be used for fusion of lumbar lesions, and there is a risk of fusion organ displacement after operation, especially in cases of bone loss or osteoporosis before surgery, end-plate injury during surgery, and Stand-alone mode, and most of them occur within 3 months after operation. Surgery is required for the transposition of the fusion apparatus in the Stand-alone OLIF mode during the primary operation. Although good clinical results could be obtained by timely detection and accurate treatment, it is still necessary to emphasize the precise selection of cases before operation, the appropriate application of OLIF, and precise operation during operation to prevent displacement of fusion device.
Humans ; Spinal Fusion/instrumentation* ; Female ; Male ; Middle Aged ; Aged ; Aged, 80 and over ; Lumbar Vertebrae/surgery* ; Retrospective Studies ; Pedicle Screws

Objective To construct a three-dimensional statistical shape model of the pelvis and analyze the individual variation and gender differences of the three-dimensional shape of the pelvis.Methods We collected CT data from 201 Chinese individuals and used deep learning to automatically reconstruct three-dimensional models of the pelvis.Through three-dimensional model registration,dense correspondence mesh mapping,and the use of statistical shape modelling(SSM)and principal component(PC)analysis method,we extracted models of variations(MoV)of pelvic shape changes and statistically compared the shape MoV between males and females.Results We analysed the top 10 principal components of shape variations,which accounted for 86.1％of the total variability.Among them,PC01,PC02,and PC04 showed significant differences between genders(P＜0.001),accounting for a total variability of 60.1％.PC08 and PC 10 demonstrated pelvic asymmetry,accounting for a total variability of 3.8％.Conclusion We constructed a three-dimensional statistical shape model of the pelvis in Chinese individuals,revealing the morphological variation and sex differences of Chinese pelvis.

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.

Objective To study the pharmacokinetic characteristics of buspirone hydrochloride tablets in healthy adult populations under conditions of fasting and postprandial administration.Methods A single-center,randomized,three-cycle partially repeated crossover trial design was adopted,and 36 subjects were enrolled on fasting/postprandial,one tablet of the test preparation was taken in one cycle,one tablet of reference preparation(5 mg of buspirone tablets)was taken once in each of 2 cycles,the drug concentration of buspirone in plasma was determined by liquid chromatography-tandem mass spectrometry,and the pharmacokinetic parameters were calculated by WinNonlin software.Results Main pharmacokinetics of buspirone after oral administration of test and reference preparations in fasting group,the Cmax was(285.72±286.08)and(308.94±341.03)pg·mL-1;AUC0-t were(577.09±491.10)and(618.62±642.56)pg·mL-1·h;AUC0-∞ were(586.85±510.04)and(655.92±687.95)pg·mL-1·h;tmax was 0.75(0.33-4.00)and 0.75(0.33-1.75)h.Main pharmacokinetics of buspirone after oral administration of test and reference preparations in the postprandial group,the Cmax were(676.36±603.64)and(760.33±610.27)pg·mL-1;AUC0-t were(1 755.58±1 001.69)and(1 743.00±1 073.33)pg·h·mL-1;AUC0-∞ were(1 839.97±1 044.60)and(1 818.00±1 106.95)pg·mL-1·h;tmax was 1.25(0.25-4.50)and 1.00(0.25-3.50)h.The 90％confidence intervals of the AUC0-t and AUC0-∞ geometric mean ratios of the test preparation and the reference preparation in the fasting test and the postprandial test all fell between 80.00％and 125.00％,and the 95％upper confidence limit of of Cmax was ≤0 and geometric mean ratios point estimates fall between 80.00％and 125.00％.Conclusion Two kinds of buspirone hydrochloride are bioequivalent in Chinese healthy adult subject.

Hemophilic arthritis(HA),caused by recurrent bleeding,can seriously affect patient quality of life and consumes extensive social and medical resources.There is thus a need to establish an animal model of HA for research;however,this is limited by ethical requirements.Here we review the recent literature and summarize research progress into animal models of HA at home and abroad,from the aspects of species selection,modeling method,histopathology,and imaging evaluation method.Species selection includes rodents such as mice,New Zealand rabbits,beagles,miniature pigs,and crab-eating macaques.Modeling method comprise gene knockout trauma models,gene knockout spontaneous models,and injection models.Among these,the gene knockout spontaneous model closely mimics the pathological process of spontaneous bleeding and concurrent arthritis in human HA,making it more relevant to human HA.However,due to high modeling costs,phenotypic instability,and low survival rates,this model is not the preferred choice for animal experimental studies.In contrast,gene knockout trauma models exhibit characteristics such as short modeling time,strong stability,and high success rates,thus being widely utilized in animal experimental research.Evaluation of HA models involves various imaging method including MRI,micro-CT,MSKUS/PD,in addition to various gross scoring method.By reviewing the progress of HA model research,more experimental evidence is provided for investigating the pathogenesis and validating the efficacy of HA treatments,thereby compensating for the lack of clinical data,particularly in the field of traditional Chinese medicine therapy.