BACKGROUND:Intertrochanteric fracture of femur has various fracture types and fixation methods,and the mechanical stability of each fixation system is quite different.It is of scientific clinical significance to use finite element analysis method to carry out biomechanical research on various fixation systems. OBJECTIVE:To compare and analyze the mechanical stability of various internal fixations applied to femoral intertrochanteric fracture A031-A2.1 by finite element method. METHODS:Based on the validated finite element model of femur(Intact),the model was cut and made into A031-A2.1 intertrochanteric fracture of femur.Different internal fixation systems were implanted by simulating clinical operation methods,and fixation models of proximal femoral nail antirotation,dynamic hip screw,percutaneous compression plate and proximal femoral locking plate were established respectively.All nodes under the distal femur of the four groups of models were constrained,and compression loads of 700,1 400 and 2 100 N were applied to the femoral head.Von Mises stress distribution and compression stiffness of each group of models were observed through calculation and analysis,and mechanical stability of each group was compared. RESULTS AND CONCLUSION:(1)Through calculation and analysis,after calculating the compression stiffness by comparing the deformation of each model,the compression stiffness of each model under various loads showed the trend:physiological group>proximal femoral nail antirotation group>proximal femoral locking plate group>percutaneous compression plate group>dynamic hip screw group.The compressive stiffness of the complete physiological group model was significantly higher than that of all surgical group models.(2)The stress index was observed.Due to the stress shielding effect,the stress peak value of each fixed group was higher than that of physiological group,and the maximum peak value was concentrated on each internal fixation.Proximal femoral nail antirotation group had the smallest stress peak,while dynamic hip screw group had the highest stress.The stress distribution trend showed physiological group

ObjectiveGliomas in the motor functional area can damage the corticospinal tract (CST), leading to motor dysfunction. Currently, there is a lack of unified methods for evaluating the extent of CST damage, especially in patients with high surgical risk where the minimum distance from the lesion to the CST is less than 10 mm. This study aims to further clarify the classification method and clinical significance of CST morphological changes in these patients. MethodsThis retrospective study analyzed 109 high-risk functional area glioma patients who underwent neurosurgical treatment with preoperative diffusion tensor imaging (DTI) imaging and intraoperative neurostimulation guidance between 2014 and 2024. All patients had a lesion-to-tract distance (LTD) of less than 10 mm between the CST and the lesion. Preoperative DTI evaluation of CST involvement-induced morphological changes were reviewed. Patients were divided into 3 groups: 17 cases (15.6%) with symmetric CST morphology compared to the healthy side (CST symmetry), 48 cases (44.0%) with significant CST morphology changes compared to the healthy side (CST deformation), and 44 cases (40.4%) with CST overlap with the tumor (CST overlap). Then we classified patients according to preoperative assessment of tumor-induced morphological changes, and analyze postoperative motor function for each category. ResultsPostoperative pathology showed a significantly higher proportion of high-grade gliomas (HGG) in the CST overlap group compared to the other two groups (P=0.001). Logistic regression analysis showed that CST overlap was a predictor of HGG (P=0.000). The rate of total tumor resection in the CST deformation group and overlap group was lower than in the CST symmetric group (P=0.008). There was a total of 41 postoperative hemiplegic patients, with 4 cases (23.5%) in the CST symmetric group, 11 cases (22.9%) in the CST deformation group, and 26 cases (59.1%) in the CST overlap group. CST overlap with the tumor predicted postoperative hemiplegia (P=0.016). Two-way ANOVA analysis of the affected/healthy side and CST morphology groups showed significant main effects of CST grouping and healthy-affected side (P=0.017 and P=0.010), with no significant interaction (P=0.31). The fractional anisotropy (FA) value in the CST overlap group and the affected side was lower. A decrease in the FA value on the affected side predicted postoperative hemiplegia (sensitivity 69.2%, specificity 71.9%). ConclusionWe have established a method to predict postoperative hemiplegia in high-risk motor functional area glioma patients based on preoperative CST morphological changes. CST overlap leads to a decrease in CST FA values. This method can be used for precise patient management and aid in accurate preoperative surgical planning.

ObjectiveAutism spectrum disorder (ASD) is a neurodevelopmental condition characterized by difficulties with communication and social interaction, restricted and repetitive behaviors. Previous studies have indicated that individuals with ASD exhibit early and lifelong attention deficits, which are closely related to the core symptoms of ASD. Basic visual attention processes may provide a critical foundation for their social communication and interaction abilities. Therefore, this study explores the behavior of children with ASD in capturing attention to changes in topological properties. MethodsOur study recruited twenty-seven ASD children diagnosed by professional clinicians according to DSM-5 and twenty-eight typically developing (TD) age-matched controls. In an attention capture task, we recorded the saccadic behaviors of children with ASD and TD in response to topological change (TC) and non-topological change (nTC) stimuli. Saccadic reaction time (SRT), visual search time (VS), and first fixation dwell time (FFDT) were used as indicators of attentional bias. Pearson correlation tests between the clinical assessment scales and attentional bias were conducted. ResultsThis study found that TD children had significantly faster SRT (P<0.05) and VS (P<0.05) for the TC stimuli compared to the nTC stimuli, while the children with ASD did not exhibit significant differences in either measure (P>0.05). Additionally, ASD children demonstrated significantly less attention towards the TC targets (measured by FFDT), in comparison to TD children (P<0.05). Furthermore, ASD children exhibited a significant negative linear correlation between their attentional bias (measured by VS) and their scores on the compulsive subscale (P<0.05). ConclusionThe results suggest that children with ASD have difficulty shifting their attention to objects with topological changes during change detection. This atypical attention may affect the child’s cognitive and behavioral development, thereby impacting their social communication and interaction. In sum, our findings indicate that difficulties in attentional capture by TC may be a key feature of ASD.

ObjectiveTo investigate the effect of nicotinamide adenine dinucleotide on vascular endothelial injury in hypertension and its molecular mechanism. MethodsC57BL/6J mice were randomly divided into saline group （Saline） and hypertension group （Ang Ⅱ， which were infused with Ang Ⅱ via subcutaneously implanted osmotic pumps）， and supplemented daily with nicotinamide mononucleotide （300 mg/kg）， a precursor of NAD⁺. Blood pressure， endothelial relaxation function and pulse wave velocity were measured after 4 weeks. Wound healing assay and adhesion assay were used to evaluate the function of endothelial cells in vitro. mtROS levels were detected by immunofluorescence staining. RT-PCR was used to detect the mRNA expression of mtDNA， SIRT3 and isocitrate dehydrogenase 2 （IDH2）. 8-hydroxy-2'-deoxyguanosine levels were detected by enzyme-linked immunosorbent assay. The protein expression levels of p-eNOS， eNOS， SIRT3 and IDH2 were detected by Western blot. ResultsNMN supplementation reduced blood pressure （P<0.001） and improved endothelial function and arterial stiffness （P<0.001） in hypertensive mice. In vitro， NMN improved endothelial function in AngII-stimulated endothelial cells （P<0.05） and attenuated mitochondrial oxidative stress levels （P<0.001）. Mechanistically， NMN elevated SIRT3 activity （P<0.001）， which subsequently enhanced IDH activity （P<0.001） and reduced oxidative stress levels in endothelial cells. Conversely， knockdown of IDH2 would reverse the effect of SIRT3 in improving endothelial function （P<0.001）. ConclusionNAD⁺ lowers blood pressure and enhances vascular function in hypertension by reducing the level of oxidative stress in endothelial cells through activation of the SIRT3/IDH2 signal pathway.

ObjectiveTo discuss the clinical manifestations and image features of Neuromyelitis Optica Spectrum Disorder （NMOSD）with respiratory insufficiency. We present a retrospective review about the use of double filtration plasmapheresis in the treatment of the acute attack of NMOSD in these patients. MethodsAll of our patients with central respiratory insufficiency who suffered attacks of NMOSD were retrospectively considered for inclusion. Extended Disability Status Scale（EDSS）scores were compared within six months after double membrane filtration plasma exchange. ResultsThe clinical data of the six patients included were analyzed. Magnetic Resonance Imaging confirmed that the demyelinating plaques in our patients could involve the medulla oblongata and upper spinal cord. They were managed by plasma exchange given as an initial therapy. The clinical symptoms improved significantly and the patients were successfully withdrawn from the ventilator，with EDSS scores significantly reduced （P<0.001）. ConclusionDemyelination of medulla oblongata and upper spinal cord in NMOSD may lead to acute life-threatening respiratory compromise， and early initiation of double filtration plasmapheresis can be a safe and effective treatment.

Objective To establish an acute rejection model of cervical heart transplantation in mice and evaluate the survival and dynamic rejection process post-transplantation. Methods Mice were randomly divided into sham operation group (n=10), syngeneic transplantation group (n=21), and allogeneic transplantation group (n=65). Sham operation, syngeneic cervical heart transplantation, and allogeneic cervical heart transplantation were performed respectively. The survival of recipient mice and grafts, histopathological changes of graft tissues, subpopulations of splenic lymphocytes, and expression of inflammatory factors in serum and grafts were observed. Results The survival rate and graft survival rate of the sham operation group and syngeneic transplantation group were 100% at 7 days after surgery. In the allogeneic transplantation group, 5 cases failed and died on the first day after surgery. The survival rate at 7 days after surgery was 86%, and all surviving mice had grafts that stopped beating at 7 days after surgery. The allogeneic transplantation group showed significant rejection at 7 days after surgery, accompanied by tissue damage and CD8⁺ T cell infiltration. The proportion of CD8⁺ T cells in the spleen continued to rise post-operation, while the proportion of CD4⁺ T cells showed a downward trend. The expression of interferon-γ in serum and grafts peaked at 5 days after surgery, while the expression of tumor necrosis factor-α showed no statistical significance. Conclusions Acute rejection following heart transplantation in mice intensifies between 5 to 7 days after surgery, which may be a critical time window for immunological intervention.

Objective: To investigate the distribution of IgM anti-A/B titers among group O whole blood donors in Jiangsu, establish a low-titer threshold, and analyze the demographic characteristics of low-titer donors, so as to provide data for recruiting low-titer group O whole blood (LTOWB) donors. Methods: Plasma samples from 1 009 group O whole blood donors were tested for IgM anti-A and anti-B titers using the microplate technique. The distribution of antibody titers was analyzed to establish a low-titer threshold. The distribution trends of titers across different demographic groups were also analyzed. Results: The peak titer for anti-A, anti-B were 64 (31.5%), 4 (23.8%), respectively, The proportion of donors with both anti-A and anti-B titers below 64 was 97.3% (982/1 009). The mean anti-A titer was higher than anti-B titer. Anti-A titers were higher in female donors than in male donors (P<0.05). The anti-A titers differed significantly among different age groups (P<0.05). However, no significant difference in titers was observed based on the number of donations (P>0.05). Conclusion: A titer of 64 can be used as the reference threshold of LTOWB in Jiangsu. Male donors of appropriate age are more suitable than female donors for establishing an emergency panel of LTOWB mobile donors.

Aim To study the role of norepinephrine in regulating cancer-associated fibroblasts to promote the proliferation and migration of lung cancer cells.Meth-ods Primary cancer-associated fibroblasts and lung cancer A549 cells were cultured.RT-PCR and West-ern blotting were used to detect the expression of VEGF,IL-6 and IL-8 in cancer-associated fibroblasts after norepinephrine intervention,and the effect of nor-epinephrine on the expression of E-cadherin and vim-entin in co-cultured CAFs and lung cancer A549 cells were evaluated,and scratching experiments were used to verify that norepinephrine promoted the migration of lung cancer A549 cells.Results Norepinephrine in-duced the high expression of VEGF,IL-8 and IL-6 in CAFs cells in a concentration-dependent manner.β-adrenergic inhibitor(propranol)could inhibit the ex-pression of VEGF,IL-8 and IL-6 in CAFs cells.Norep-inephrine could inhibit the expression of E-cadherin in lung cancer A549 cells co-cultured with CAFs,promote the upregulation of vimentin,and enhance the migration ability of A549 cells.Conclusion Norepinephrine promotes the proliferation and migration of lung cancer A549 cells through CAFs.

Objective Mobile artificial lumbar complex(MALC)which suitable for reconstruction after subtotal lumbar resection in goats was developed,and to test stability of the complex and postoperative lumbar segmental motor function.Methods Eighteen male boer goats aged from 1 to 2 years old(weighted from 35 to 45 kg)were selected and divided into con-trol group,fusion group and non-fusion group,with 6 goats in each group.According to preoperative CT scans and MRI exami-nations of lumbar,the goat MALC was designed and performed by 3D printed for non-fusion group.Operation was performed on three groups respectively,and only vertebral body and disc were exposed in control group.In fusion group,L4 part of vertebral body and the upper and lower complete disc tissues were removed,and the lumbar spine bone plate fixation was performed with titanium mesh bone grafting.In non-fusion group,vertebral body and disc were removed in the same way,and MALC was im-planted.AP and lateral X-rays of lumbar vertebrae in goat were taken at 6 months after surgery,in order to understand whether the plant was dislocated,displaced and fractured.Biomechanical tests were performed on the specimens by mechanical instru-ment to measure range of motion(ROM)of L2,3,L,4,L4,5intervertebral space and the overall ROM of L2-5 lumbar vertebrae.Results MALC of lumbar vertebra was designed by 3D printing,and its component artificial vertebrae and upper and lower ar-tificial end plates were manufactured.The semi-spherical structure was fabricated by precision lathe using high-crosslinked polyethylene material,and the prosthesis was assembled.Postoperative AP and lateral X-rays of lumbar vertebra at 6 months showed the implant position of implant and MALC were good without displacement and dislocation.In vitro biomechanical test of lumbar vertebrae specimens:(1)There were no statistical significance in ROM of lumbar intervertebral space flexion and extension,lateral flexion and rotation on L.4 and L4,5,between non-fusion group and control group(P＞0.05),while ROM of fu-sion group was significantly reduced compared with the other two groups(P＜0.05).There were no significant difference in ROM of L2.3 intervertebral flexion and extension,lateral flexion and rotation between non-fusion group and control group(P＞0.05),while fusion group was significantly increased compared with the other two groups(P＜0.001).(2)There was no signifi-cant difference in overall lumbar ROM of L2-5(P＞0.05).Conclusion The individual MALC could restore intervertebral height of lumbar vertebra while maintaining the stability of lumbar vertebra and re-establishing motor function of lumbar space.

Objective To investigate the clinical effect of anterior cervical discectomy and fusion(ACDF)in the treatment of cervical spondylosis of vertebral artery type(CSA).Methods The clinical data of 42 patients with CSA from January 2020 to January 2022 were retrospectively analyzed.There were 25 males and 17 females,aged from 30 to 74 years old with an average of(53.9±11.0)years old.There were 18 cases with single-segment lesions,17 cases with two-segment lesions,and 7 cases with three-segment lesions.The American Academy of Otolaryngology-Head and Neck Surgery's Hearing and Balance Committee score(CHE),the Neck Disability Index(NDI)and the cervical curvature Cobb angle were recorded before surgery and after surgery at 6 months.Results All 42 ACDF patients were followed up for 6 to 30 months with an average of(14.0±5.2)months.The operative time ranged from 95 to 220 min with an average of(160.38±36.77)min,the intraoperative blood loss ranged from 30 to 85 ml with an average of(53.60±18.98)ml.Tow patients had mild postoperative dysphagia,which improved with symptomatic treatment such as nebulized inhalation.CHE score decreased from(4.05±0.96)preoperatively to(2.40±0.70)at 6 months postoperatively(t=12.97,P＜0.05).The number of improved vertigo at 6 months postoperatively was 38,with an im-provement rate of 90.5％.NDI score was reduced from(34.43±8.04)preoperatively to(20.76±3.91)at 6 months postopera-tively(t=1 1.83,P＜0.05).The cervical curvature Cobb angle improved from(8.04±6.70)° preoperatively to(12.42±5.23)° at 6 months postoperatively(t=-15.96,P＜0.05).Conclusion The ACDF procedure has outstanding clinical efficacy in treating CSA.The operation can rapidly relieve patients'episodic vertigo symptoms by relieving bony compression and reconstructing cervical curvature.However,it is necessary to strictly grasp the indications for surgery and clarify the causes of vertigo in pa-tients,and ACDF surgery is recommended for CSA patients for whom conservative treatment is ineffective.