Pulmonary hypertension(PH)is the pulmonary vascular remodeling caused by endothe-lial dysfunction and other factors,which leads to the increase of pulmonary artery pressure and finally right heart failure and patient death.Medications can significantly improve the symptoms of patients with pulmonary hypertension,but drugs can't cure vascular remodeling and right heart failure once for all,so it is urgent to find new treatments.Endothelial cells can obtain mesenchymal phenotypes after hypoxia stimulation,that is,endothelial-to-mesenchymal transition(EndMT).Increasing studies have shown that EndMT plays an important role in pulmonary vascular remodeling of PH.In this review,three signaling pathways related to induction of endothelial-to-mesenchymal transition under hypoxic conditions and research progress in related drugs are elaborated:① Transforming growth factor-β/bone morphogenetic protein(TGF-β/BMP)signaling pathway.The TGF-β/BMP pathway is mediated by Smad,and hypoxia regulates the expressions of EndMT-related genes by inhibiting or inducing the phosphorylation level of Smad in the downstream medium.② Notch signaling pathway.Hypoxia can enhance Jagged/Notch signaling pathway and promote the EndMT process.③Wnt/β-catenin signaling pathway.Hypoxia increases the expression of β-catenin,activates the Wnt signaling pathway,and regulates the expressions of EndMT regulatory genes.The significance of hypoxia-induced EndMT as an impor-tant pathogenic factor in PH is clarified in order to provide new ideas for the improvement of pulmonary vascular remodeling and recommend new effective strategies for the prevention and treatment of PH.

Objective:To construct a three-dimensional calcaneal finite element model and study its biomechanical distribution by finite element analysis.Methods:Four large calcaneal specimens were taken from the Department of Human Anatomy of Kangda College of Nanjing Medical University in the second semester of 2021—2022. Micro CT scans were performed to obtain the image data of these specimens, and then the three-dimensional calcaneal model was reconstructed using the Mimics and Geomagic Wrap software. The obtained data were imported into the finite element analysis software to perform the material assignments and mesh delineation to obtain the three-dimensional finite element model. The boundary constraints were set, and loads were applied to the calcaneal model to perform finite element analysis calculations, and the stresses and displacements of the finite element model were extracted.Results:The three-dimensional calcaneal model had a high simulation quality. The morphology and structure were complete and without defects, and the size was consistent with that of the real calcaneus, which restores the original bony morphology and structure. The geometric appearance of the three-dimensional calcaneal model after meshing was vivid and lifelike, and without defect. The reconstructed morphology and structure of the three-dimensional model were the same as those of the three-dimensional reconstruction, the size was the same, and the main structure was clearly visible. The meshes and nodes of each component of the three-dimensional calcaneal model were uniformly distributed, and their numbers were comparable to those of the real heel bone. The maximum stresses of the three-dimensional calcaneal model were in the cortical bone, and the maximum stresses were in the same position. These two positions were the lowest part of the anterior part of heel bones. The maximum displacements in the three-dimensional calcaneal model were all less than 0.10 mm.Conclusions:A high-precision three-dimensional finite element calcaneal model has been constructed, which is of good mechanical validity.

Objective: To identify the risk factors for early fluid overload(FO)following repair in the pediatric patients with anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) complicated with moderate or severe left ventricular dysfunction (left ventricular ejection fraction [LVEF]<50%) and evaluate the effect on clinical outcomes. Methods: Forty-three pediatric patients with ALCAPA complicated with moderate or severe left ventricular dysfunction, aged 2-128 months, weighing 4.5-34.5 kg, with New York Heart Association Ⅲ or Ⅳ, undergoing ALCAPA repair, were enrolled in this study.The pediatric patients were divided into FO≥5% group (n=14) and FO<5% group (n=29) according to the FO developed within 24 h after operation. The pediatric Risk, Injury, Failure, Loss, and End-Stage Renal Disease criterion was used to diagnose acute kidney injury developed after operation. Factors including age, height, weight, preoperative LVEF, preoperative biomarkers, operative data, postoperative ventilation time, duration of intensive care unit(ICU)stay and related postoperative clinical outcome parameters were recorded.The risk factors of which P values were less than 0.05 would enter the multivariate logistic regression analysis to stratify the risk factors for FO≥5% developed within 24 h after operation.The effect of FO≥5% on postoperative severe acute kidney injury (Injury and Failure), ventilation time, duration of ICU stay and etc. was assessed. Results: Fourteen cases developed early postoperative FO≥5%, and the incidence was 33%.The results of the logistic regression analysis showed that lower preoperative LVEF was an independent risk factor for early postoperative FO≥5% (P<0.05). Compared with FO<5% group, the postoperative ventilation time and duration of ICU stay were significantly prolonged, the number of pediatric patients who developed pulmonary infection and required reintubation was increased, the number of pediatric patients in whom duration of ICU stay was more than 14 days was increased (P<0.05), and no significant change was found in the other parameters of clinical outcomes in FO≥5% group (P>0.05). Conclusion Lower preoperative LVEF is a risk factor for early postoperative FO in pediatric patients with ALCAPA complicated with a moderate or severe left ventricular dysfunction undergoing repair, and it is not helpful for clinical outcomes in pediatric patients when postoperative early FO≥5% occurs.

Objective: To detect the thickness of silicon coating film for glass injection bottles by focused ion beam (FIB) emission scanning electron microscopy and investigate the stability and uniformity of the film.Methods: The boron silicon coating injection bottles were selected as the experimental samples and treated with such stability experiments as ultrasonic cleaning, high temperature resistance, heat resistance, water resistance, acid resistance and alkali resistance.The samples were vertically cut by the ion beam from an FIB field emission scanning electron microscope, and the thickness of the cutting face was measured by the built-in measuring module of the scanning electron microscope.Results: The thickness of silicon film was stable and uniform.Conclusion: The film thickness of glass bottles can be accurately detected, and the film stability and uniformity can be reflected directly and objectively by using an FIB double beam field emission scanning electron microscope.

Objective Few studies are reported on the construction of a finite element model of human complex knee joint using multimodality CT and MRI images.In this study, we developed a finite element model of the knee joint for total knee arthroplasty (TKA) using matched and fused CT and MRI data, hoping to provide a useful tool for the simulation study of knee joint biomechanics of TKA.Methods The CT and MRI image data about an intact knee of a 26-year-old male volunteer were imported into the Mimics software for the establishment of 3D models of bony and soft-tissue structures.A complete knee model was developed following the registration and fusion of the constructed 3D models based on the external landmarks.After the simulated implantation of TKA components, a finite element model of the TKA knee was constructed with the Hypermesh software.Then the finite element model was analyzed following the definition of its material behavior, boundary conditions and loading.Results The finite element model of the TKA knee, which was composed of bones, ligaments, components, polyethylene insert and bone cement, was developed from CT-MRI image registration and fusion and maintained its important spatial relationship among different structures in the TKA knee.The results obtained from the finite element analysis showed the characteristics of stress distribution in the TKA knee.Conclusion The finite element model of the knee joint for TKA can be established by matching and fusing CT and MRI image data, which can be employed as a useful tool for the study of knee joint biomechanics of TKA.

Objective To assess the value of CT perfusion imaging in differentiation of mild from moderate liver fibrosis .Methods 18 patients with mild liver fibrosis (F1 phase) and 21 ones with moderate fibrosis (F2 and F3 phase) confirmed by liver biopsy were analyzed ,and all patients underwent the liver 256‐slice CT perfusion imaging .The differences in the CT parameters including hepatic arterial perfusion (HAP) ,portal venous perfusion (PVP) ,total liver perfusion (TLP) and time to peak (TTP) between dif‐ferent fibrosis were analyzed .ROC curve was used to evaluate the ability of perfusion indexes to distinguish mild from moderate liver fibrosis ,then the maximum Youden index was selected as a cutoff point to calculate the sensitivity and specificity .Results Compared with the mild fibrosis ,the TTP [(43 .86 ± 13 .41)s vs (37 .84 ± 9 .97)s ,P=0 .034)] in liver with moderate fibrosis was significantly increased .However ,no differences in the HAP ,PVP and TLP were found .The ROC curve analysis showed that a TTP threshold of 41 .7 s allowed discrimination of mild from moderate fibrosis with a sensitivity of 72 .7% and a specificity of 75% .Conclusion 256‐slice CT perfusion imaging can reflect the hemodynamic changes of liver fibrosis ,and the TTP may help to discriminate mild from moderate fibrosis .

Objective To investigate the imaging features of alar ligament and its extent, and provide the basis forclinical treatment.Methods 3.0 T superconducting MRI was used to scan the alar ligament with high resolution PDWI sequence (Proton density weighted imaging, PDWI)in 109 patients of emergency admissions due to head and neck trauma. Based on imaging features, ligamentous injury was classified into three degrees(Ⅰ to Ⅲ degrees).Patients with Ⅰ degree ligamentous injury were treated conservatively, andⅡtoⅢdegree injury patients were treated with surgery, then follow-up was performed with MRI for the recovery of ligaments and clinical evaluation for symptoms (6 months follow-up period). Results High-resolution PDWI showed 78 patients with no ligament injury.On follow-up, patients recovered well (atlantoaxial joint motor function and clinical symptoms). Thirty one patients had alar ligament injury in varying degrees, of which 18 patients had grade Ⅰ injury, nine patients had degree Ⅱinjury, and four patients had degreeⅢinjury .All gradeⅠinjury patients received conservative treatment. Follow-up of patients showed good recovery, MR revealed the lesions shrank in varying degrees or disappear.
Six gradeⅡinjury patients had surgical treatment, and three received conservative treatment. On follow-up, seven patients had a good recovery, two patients underwent surgical treatment within 3 months after injury and recovered well.Three gradeⅢpatients treated by surgery, and all with good recovery postoperative, and a patient died of respiratory failure. Conclusions High resolution PDWI is an effective tool to evaluate the extent of the alar ligament injury. Grade Ⅰ ligamentous injury patients treated conservatively can achieve good results, GradeⅡandⅢligamentous injury patients should receive surgical treatment early.

BACKGROUND:Bone marrow stem cels combined with traditional surgery regimen can significantly improve the therapeutic effects on bone nonunion, which are considered to have an important application value. OBJECTIVE:To explore therapeutic effect of bone marrow mesenchymal stem cels on bone nonunion under micro-damage environment. METHODS:Forty New Zealand white rabbits were selected and randomized into experimental and control groups, 20 rabbits in each group. Bone marrow of the tibia was extracted to isolate and culture bone marrow mesenchymal stem cels. Passage 3 cels with the order of magnitudes of 107 were labeled by superparamagnetic iron oxide nanoparticles. A 15-mm bone defect was made at the middle of the radius of the rabbit forelimb. Bone nonunion appeared at 6 weeks after bone defects. Bone marrow mesenchymal stem cels combined with iliac particles were implanted into the bone defect of rabbits in the experimental group, and only iliac particles were implanted into the bone defect of rabbits in the control group. Within 12 weeks after implantation, the bone nonunion was observed through gross morphology, X-ray observation, and pathological observation. RESULTS AND CONCLUSION:After implantation, a remarkable calus was found in the experimental group, and the bone defect recovered gradualy until it was completely healed; in the control group, there was no calus, and the bone marrow cavity was closed and ful of granulation tissues. In the experimental group, there were actively proliferated cartilage tissues, bone particles were fused, osteoid structures appeared, and osteoblasts proliferated progressively; in the control group, poor cartilage hyperplasia was found, and there were a large amount of dead bone tissues but no fused bone particles and osteoblasts. In the experimental group, X-ray films on the defected radium showed cloudiness-like shadow, the bone marrow cavity was recanalized, and the skeleton was shaped wel; in the control group, few bone particles were absorbed, the bone marrow cavity was partly recanalized, and the injured bone was not healed with osteosclerosis. These findings indicate that under the micro-damage environment, bone marrow mesenchymal stem cels can differentiate into osteoblasts to repair bone defects-induced bone nonunion.

OBJECTIVE: To observe the imaging features for chronic whiplash alar ligament injury in elderly patients and to provide an effective diagnostic method for long-term neck pain and headaches due to alar ligament injury in elderly patients. METHODS: A total of 134 elderly patients, who engaged in the work or activities related to whiplash motion and suffered from chronic neck pain, were enrolled for the study. All patients were performed comprehensive health examination (CT, MR, ultrasound and laboratory examination) and high resolution PDWI. The patients were divided into 2 groups according to the results of comprehensive health examination: a clear etiology group(CE group, n=96) and an unknown etiology group(UE group, n=38). Th e characteristics of PDWI signal in the ligament were analyzed between the 2 groups. RESULTS: Th e anatomy and signal characteristics of the alar ligament were clearly displayed by high resolution PDWI. Th e alar ligaments were effectively displayed by oblique coronal image. In the CE group, 7 patients (7/96) showed the positive sign of ligament injured, while 21 (21/38) patients showed positive sign of ligament injured in the UE group (P<0.01). Chronic whiplash ligament injury was proved to be the reason for long-term neck pain and headaches in 15.7% patients. CONCLUSION Th e whiplash injury of alar ligament is an important reason for chronic neck pain in elderly patients. High resolution PDWI is an effective method to evaluate the image features of alar ligament and can provide an accurate diagnosis for chronic neck pain and headaches caused by the alar ligament whiplash injury.
Aged ; Cervical Vertebrae ; Chronic Pain ; Fascia ; Humans ; Ligaments ; pathology ; Magnetic Resonance Imaging ; Whiplash Injuries ; diagnosis

Objective To identify the risk factors for early postoperative elevation in body temperature in patients undergoing coronary artery bypass grafting (CABG).Methods Nine hundred and forty-one patients of both sexes,aged 14-70 yr,were assigned into hyperthermia (≥ 38 ℃) group or non-hyperthermia (＜ 38 ℃) group according to the bladder temperature at 8h after operation.Factors including age,sex,height,weight,complications (hypertension,hyperlipemia,diabetes),history of smoking and drinking,preoperative blood pressure,heart rate,ejection fraction,routine blood examination,routine urine examination,and respiratory function examination,intraoperative cardiopulmonary bypass (CPB) and hormone,operation time,extubation time,duration of stay in the intensive care unit,and blood pressure,heart rate,ejection fraction,routine blood examination,and routine urine examination at the end of operation,and postoperative analgesia were recorded.The risk factors of which P values were less than 0.05 would enter the multi-factor logistic regression analysis to stratify the risk factors for early postoperative elevation in body temperature after CABG.Results Six hundred and ninety patients developed early postoperative elevation in body temperature (73.3％).Logistic regression analysis showed that preoperative respiratory dysfunction,preoperative ejection fraction ≤ 50％ and CPB were independent risk factors for early postoperative hyperthermia after CABG (P ＜ 0.05).Conclusion Preoperative respiratory dysfunction,preoperative ejection fraction≤ 50％ and CPB are independent risk factors for early postoperative elevation in body temperature in patients undergoing CABG.