BACKGROUND:The surgical treatment of severe lumbar fractures is mainly based on posterior short-segment fixation,and different pedicle screw fixation methods have differences in biomechanical properties.OBJECTIVE:To simulate three different screw fixation techniques in the treatment of severe L1 vertebral fractures using three-dimensional finite element technology,and to compare and analyze the biomechanical characteristics of the upper and lower intervertebral discs,fractured vertebrae,and internal fixation devices during the simulated spinal movement.METHODS:A three-dimensional model of the T11-L3 spine was established to simulate severely unstable fracture of the lumbar 1 vertebral body using the designed three pedicle screw fixation methods:Model A with 4 traditional pedicle screws(2 in each T12 and L2),model B with 4 Universal Spine System pedicle screws(2 in each T12 and L2),and Model C were bilateral intermediate fixation with 6 pedicle screws(2 in each of T12,L1,and L2).Restraint and load were applied to simulate the maximum stress and maximum displacement of the internal fixation,the displacement of the L1 vertebral body,and stress on the intervertebral discs superior and inferior to the injured vertebra during the anterior flexion,posterior extension,left-sided bending,right-sided bending and left-right rotation of the lumbar spine.RESULTS AND CONCLUSION:(1)The maximum displacement and motion range of the lumbar 1 vertebra with Model C in flexion and extension,left bending,right bending,left rotation,and right rotation were lowest in the tested motion states;the maximum stress of the screws and connecting rods was the smallest;and the maximum stress of intervertebral discs superior and inferior to the injured vertebra was the smallest.This was followed by the Model B,while the maximum displacement and motion range of the lumbar 1 vertebra and the stress and displacement of the screw connecting rod in the Model A were highest,but it showed the worst biomechanical stability and was more prone to adjacent segment degeneration.(2)These results show that bilateral intermediate fixation with six pedicle screws during the treatment of severe lumbar fractures is more dispersed in internal fixator stress and exhibits the least displacement and motion range of the vertebral pedicle screws and rods compared with four universal spinal system pedicle screws and four traditional pedicle screws.Thus,it can effectively reduce the occurrence of internal fixation failure and the adjacent segment degeneration.

Objective:To investigate the survival outcomes and prognostic factors in patients undergoing radical resection for pancreatic body and tail cancer.Methods:A retrospective case series study was conducted on 992 patients who underwent radical resection for pancreatic body and tail cancer at the Pancreatic Center of the First Affiliated Hospital of Nanjing Medical University from January 2016 to June 2024. In this study, 577 (58.2%) were male and 415 (41.8%) were female,with an age of (65±9) years (range: 26 to 86 years). Follow-up continued until June 2024. Survival rates were estimated using the Kaplan-Meier method,and prognostic factors were identified using univariate and multivariate Cox proportional hazards models.Results:Among 992 patients,open surgery was the predominant approach (89.1%, 884/992), and radical antegrade modular pancreatosplenectomy (RAMPS) was performed in 317 patients (32.0%). Combined organ resection,venous resection,and arterial resection were performed in 23.5%, 9.3%,and 11.2% of patients,respectively. The rates of R0, R1-1 mm, and R1-direct resections were 49.8% (494/992),41.5% (412/992), and 8.7% (86/992),respectively. Stage ⅡB was the most common TNM stage (32.2%,319/992). A total of 801 patients (80.8%) received adjuvant chemotherapy. The median follow-up period was 32.0(8.8) months(range:3.2 to 105.3 months),during which 508 patients (51.2%) died. The overall median survival (OS) was 26.4 months,with 1-,3-, and 5-year survival rates of 79.0%,40.0%, and 29.0%, respectively. In the recent five years (from 2020 to 2024), the median OS improved significantly to 34.1 months compared to 20.0 months from 2016 to 2019 ( P<0.01). Histological subtype analysis showed that the median OS time was 26.7 months for pancreatic ductal adenocarcinoma (PDAC, n=855),58.9 months for invasive intraductal papillary mucinous carcinoma (IPMC, n=32),and 15.7 months for adenosquamous carcinoma of pancreas (ASCP, n=73) ( P=0.001). Among PDAC patients, adjuvant chemotherapy significantly improved survival (29.1 months vs. 14.4 months, P<0.01);in IPMC patients, adjuvant chemotherapy also extended survival (65.7 months vs. 58.9 months, P=0.047). Although ASCP patients receiving chemotherapy had a longer median OS time than those without (18.8 months vs. 8.9 months),the difference was not statistically significant ( P=0.151). Multivariate Cox regression analysis in PDAC patients indicated that adjuvant chemotherapy, R0 resection, T stage,N stage,and tumor differentiation were independent prognostic factors ( P<0.01). The median OS time by TNM stage was:not reached for stage ⅠA, 51.6 months for ⅠB, 25.5 months for ⅡA, 23.7 months for ⅡB, 23.0 months for Ⅲ, and 14.4 months for Ⅳ. The median OS time for R0,R1-1 mm,and R1-direct resections was 34.1,24.7,and 15.7 months,respectively ( P<0.01). Conclusion:Adjuvant chemotherapy,R0 resection,tumor stage,and differentiation are independent prognostic factors for pancreatic body and tail cancer.

Objective:To investigate the pathological characteristics of post-cholecystectomy specimens from patients with benign gallbladder diseases.Methods:This retrospective case series study analyzed clinical and pathological data from 1 712 patients who underwent cholecystectomy for benign gallbladder diseases at the Sixth People′s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine between September 2022 and August 2024. The cohort included 757 males and 955 females, with an age ( M(IQR)) of 57(23) years (range: 14 to 91 years). Clinical and pathological features were analyzed. The χ2 test was used to compare clinical characteristics between patients with neoplastic and non-neoplastic polyps. Factors statistically significant in the χ2 test were subsequently included in a binary logistic regression analysis. Results:Postoperative pathological examination revealed gallbladder cancer in 7 patients (0.41%). These 7 cases, including 2 with pT3 stage cancer, were not detected preoperatively by various imaging examinations (ultrasound+magnetic resonance cholangiopancreatography/MRI plain scan in 3 cases, ultrasound+enhanced MRI in 1 case, ultrasound+enhanced CT in 2 cases, enhanced CT+enhanced MRI in 1 case). Gallbladder adenoma was found in 23 cases (1.34%), neoplastic polyps (including cholesterol polyps with dysplasia) in 29 cases (1.69%), and non-neoplastic polyps in 154 cases (9.00%). Statistically significant differences were observed in age and polyp number between patients with neoplastic and non-neoplastic polyps ( χ2=10.436 and 8.030; both P<0.05). Binary logistic regression analysis identified age ≥60 years ( P=0.003) and solitary polyps ( P=0.009) as risk factors for neoplastic polyps. Mucosal dysplasia was present in 164 cases (9.58%), including 9 cases of severe dysplasia, 4 of which exhibited focal carcinomatous transformation. Gallbladder polyps combined with stones were found in 90 cases (5.26%), among which 10 were associated with adenoma and mucosal dysplasia, and 2 showed focal carcinomatous transformation. Conclusions:The incidence of incidental gallbladder carcinoma was 0.41%. Intraoperative bile spillage can severely compromise prognosis. Preoperative imaging demonstrates a low detection rate for neoplastic polyps. Particular vigilance for neoplastic polyps is warranted in patients aged ≥60 years or with solitary polyps. Cholecystectomy should be performed promptly for benign gallbladder diseases meeting surgical indications.

Objective To systematically evaluate the therapeutic effects of video-assisted thoracoscopic surgery (VATS) and robot-assisted thoracic surgery (RATS) in treating mediastinal tumors. Methods A computer search was conducted on PubMed, Embase, Cochrane Library, Web of Science, Wanfang, CNKI, CBM, VIP databases for literature comparing the clinical efficacy of VATS and RATS in treating mediastinal tumors, with the search time from inception to March 31, 2024. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the included cohort studies, and Review Manager 5.4 software was used to perform a meta-analysis. Results A total of 32 articles were included, with 7868 patients. The NOS scores of the included cohort studies were all≥7 points. Meta-analysis results showed that compared with the VATS group, the RATS group had less intraoperative blood loss [MD=−16.71, 95%CI (−23.88, −9.54), P<0.001], lower conversion rate to open thoracotomy [OR=0.41, 95%CI (0.26, 0.67), P=0.003], lower overall postoperative complication rate [OR=0.66, 95%CI (0.48, 0.92), P=0.01], shorter postoperative drainage time [MD=−0.64, 95%CI (−0.92, −0.36), P<0.001], and shorter postoperative hospital stay [MD=−1.03, 95%CI (−1.28, −0.78), P<0.001]. There was no statistical difference between the two groups in terms of tumor size [MD=−0.06, 95%CI (−0.31, 0.19), P=0.64] or operation time [MD=5.52, 95%CI (−2.35, 13.40), P=0.17]. The RATS group had higher hospitalization costs than the VATS group [MD=1.69, 95%CI (1.26, 2.13), P<0.001]. Conclusion In mediastinal tumors resection, RATS is superior to VATS in terms of intraoperative blood loss, conversion rate to open thoracotomy, overall postoperative complication rate, postoperative drainage time, and postoperative hospital stay, but it increases hospitalization costs.

Objective To systematically evaluate the differences in outcomes between functional mitral regurgitation (FMR) and degenerative mitral regurgitation (DMR) in patients treated with transcatheter edge-to-edge repair (TEER) using the MitraClip device. Methods A systematic literature search was conducted in PubMed, Embase, the Cochrane Library, Web of Science, the CNKI, Wanfang Database, VIP Database, and the CBM from their inception to January 2024. Two researchers independently performed study selection, data extraction, and risk of bias assessment. The quality of cohort studies was evaluated using the Newcastle-Ottawa Scale (NOS). A meta-analysis was performed using Stata 18.0 software. Results A total of 13 cohort studies involving 6 402 patients were included, comprising 4 161 patients in the FMR group and 2 241 in the DMR group. All included studies had NOS scores of ≥6 points. The meta-analysis revealed that compared to the DMR group, the FMR group had a higher 1-year all-cause mortality rate [OR=1.53, 95%CI (1.30, 1.81), P＜0.01] and a higher 1-year rehospitalization rate for heart failure [OR=1.90, 95%CI (1.60, 2.26), P＜0.01]. Conversely, the FMR group had a lower post-procedural mean transmitral gradient [SMD=–0.47, 95%CI (–0.65, –0.30), P＜0.01] and a lower rate of subsequent mitral valve surgery [OR=0.41, 95%CI (0.20, 0.83), P=0.01]. Conclusion Following MitraClip therapy, patients with FMR exhibit favorable short-term outcomes, but their mid- to long-term outcomes are inferior to those of patients with DMR. When determining the treatment strategy with MitraClip, the specific etiology of mitral regurgitation should be considered for a more accurate prediction of therapeutic efficacy and prognosis.

Objective: To explore the longitudinal relationship between bullying victimization and sleep quality among rural boarding junior high school students in Hebei Province, and to investigate the chain mediated role of loneliness and rumination, so as to provide evidence for promoting sleep health in the population. Methods: A baseline survey was conducted in May, 2023 (T1) by convenient sampling method, and two rounds of longitudinal surveys were conducted in November, 2023 (T2) and May, 2024 (T3) among students in two rural boarding junior high schools in Hebei Province, and a sample of 601 students who completed all the surveys was finally obtained. Students completed questionnaires, including the Delaware Bullying Victimization Scale Student (DBVS-S), the University of California at Los Angeles Loneliness Scale (UCLA), the Ruminative Responses Scale, and the Pittsburgh Sleep Quality Index (PSQI). Group differences were examined by using t-test or ANOVA, correlations between variables were analyzed by using Pearson correlation coefficients, and a serial mediation structural equation model was constructed, with mediation effects tested via the Bootstrap method. Results: Female students scored higher on sleep quality than male students (7.47±2.70, 6.47 ±2.46, t =4.74, P <0.01). Pearson correlation analysis indicated that bullying victimization was positively correlated with loneliness, rumination, and sleep quality; loneliness was positively correlated with rumination and sleep quality; and rumination was positively correlated with sleep quality ( r =0.26, 0.33, 0.23; 0.39, 0.38; 0.54, all P <0.01). Mediation analysis showed that T2 loneliness had an independent mediating effect of 0.70 (95% CI =0.36-1.35) between T1 bullying victimization and T3 sleep quality, T2 rumination had an independent mediating effect of 1.34 (95% CI =0.71-2.45), and the serial mediation effect of T2 loneliness and T2 rumination was 0.64 (95% CI =0.37-1.13), accounting for 22.11% of the total effect (all P <0.01). Conclusions Bullying victimization adversely affects sleep quality among rural boarding junior high school students through a longitudinal chain mediating pathway involving loneliness and rumination. Psychological interventions should be strengthened for students who experience bullying to alleviate their loneliness and reduce rumination, thereby improving sleep quality.

The core pathogenesis of attention deficit hyperactivity disorder （ADHD） lies in deficiency， stasis and stagnation. Deficiency arises from kidney essence depletion and spleen dysfunction in transportation and transformation， leading to inadequate nourishment of the marrow sea. Stasis caused by qi deficiency leads to obstruction in channels and collaterals， resulting in obstructed marrow transport. Stagnation is associated with the excess of the five minds transforming into fire， which scorches the brain orifices and leads to loss of control over marrow utilisation. Based on this， a "supplementation-unblocking-regulation" therapeutic approach is proposed. For deficiency， the focus is on supplementing kidney and fortifying spleen， and replenishing the marrow sea. For stasis， the priority is to unblock and open the orifices， and clear the marrow channels. For stagnation， the core is to clear fire and contain the mind， regulate and restore vital activity. In clinical practice， it is necessary to identify the primary and secondary pathogenic mechanisms and apply dynamic， combined treatment， integrating Chinese herbal medicine， acupuncture， and guiding exercises throughout the process， aiming to provide a reference for the diagnosis and treatment of ADHD with traditional Chinese medical.

Tetrodotoxin（TTX）is a potent neurotoxin known for its specific sodium channel blocking effects, widely used in biomedical research. While TTX has been identified in various marine organisms, its true origin remains unclear, and the specific biosynthetic pathways are yet to be elucidated. The reported sources of TTX and the progress in research on TTX biosynthesis were summarized, with a focus on potential microbial sources of TTX, which could provide scientific reference for the production and biosynthesis studies of TTX.

ObjectiveTo clarify whether METTL14 mediates the core role of acupuncture at Neiguan (PC6) in promoting myelination and improving behavior in young autistic rats through gene intervention technology. MethodsThe ASD model was established by intraperitoneal injection of valproic acid (VPA) in pregnant rats. Male offspring were intracerebroventricularly injected with adenovirus-packaged METTL14 shRNA (sh-METTL14) or its control (sh-NC) on postnatal day 1, with a model group set as well. Subsequently, the juvenile rats were divided into model group, acupuncture group, acupuncture+sh-NC group, and acupuncture+sh-METTL14 group. The acupuncture group received acupuncture at Neiguan (PC6) from postnatal day 7, once daily for 21 consecutive days. Neurobehavioral changes were evaluated by behavioral tests; METTL14 knockdown efficiency and the expression of METTL14, METTL3, and PTEN were detected by quantitative real-time PCR (qRT-PCR) and Western blot (WB); PTEN m⁶A levels were measured by RNA immunoprecipitation-qPCR (RIP-qPCR); myelin ultrastructure, expression of myelin basic protein (MBP) and neurofascin 155 (NF155), and dendritic spine density were observed using transmission electron microscopy (TEM), enzyme-linked immunosorbent assay (ELISA), immunofluorescence, qRT-PCR, and primary neuron culture. ResultsBehaviorally, knockdown of METTL14 significantly counteracted the beneficial effects of acupuncture in improving self-grooming, open field exploration, three-chamber social interaction, and Morris water maze learning and memory (P<0.05, P<0.01). Compared with the acupuncture+sh-NC group, the acupuncture+sh-METTL14 group showed significantly decreased mRNA and protein expression of hippocampal METTL14 (P<0.01), and the upregulating effects of acupuncture on METTL3 and PTEN expression were reversed (P<0.01). Meanwhile, knockdown of METTL14 significantly inhibited the acupuncture-induced increase in PTEN m⁶A levels (P<0.01). Morphologically, knockdown of METTL14 attenuated the improvement of myelin structure by acupuncture, reversed the downregulation of MBP and upregulation of NF155 induced by acupuncture, and blocked the increase in dendritic spine density (P<0.05, P<0.01). ConclusionMETTL14 is a key molecule mediating the therapeutic effect of acupuncture at Neiguan. Acupuncture at Neiguan upregulates METTL14, thereby enhancing m⁶A methylation modification of PTEN mRNA to stabilize its expression, ultimately promoting myelin development and improving behavioral symptoms in ASD juvenile rats. This preliminarily reveals the modern biological connotation of “opening Xuanfu and dredging myelin”.

The initiation of adaptive immune responses relies on the precise recognition and interpretation of antigenic information. In this process, the specific binding of T cell receptors (TCRs) to peptide-major histocompatibility complex (pMHC) molecules represents one of the key molecular events in the initiation of adaptive immune responses. Accordingly, the structural features of TCR-pMHC complexes provide a fundamental basis for dissecting antigen recognition mechanisms and support rational vaccine design, therapeutic target discovery in TCR-based immunotherapy, and TCR identification and optimization. However, experimental determination of TCR-pMHC structures remains costly, time-consuming, and limited in coverage, making computational approaches essential for rapidly obtaining reliable structural information. Computational methods for predicting the structures of TCR-pMHC complexes have advanced rapidly in recent years, driven by progress in deep learning-based modeling frameworks and the increasing availability of structural and sequence resources. Despite these developments, most existing tools do not adequately distinguish the key structural and biophysical differences between MHC class I (MHC-I) and MHC class II (MHC-II) complexes during model construction. As a consequence, their predictive performance differs substantially between class I and class II complexes. In general, structural predictions for class I complexes outperform those for class II complexes. This discrepancy may be related to several fundamental differences between the two systems, including the architecture of the peptide-binding groove, the distribution of peptide lengths, and the properties of peptide flanking residues (PFRs). Compared with MHC-I molecules, MHC-II molecules usually bind longer antigenic peptides, which typically range from 13 to 25 amino acids in length. PFRs at both termini of these peptides participate in regulating the overall conformation of TCR-pMHC class II complexes and exert a pronounced effect on the geometric and physicochemical characteristics of the TCR-pMHC binding interface. Furthermore, within the TCR recognition interface, the complementarity-determining regions (CDRs) consist of segments that differ markedly in conformational behavior. They commonly include regions that are relatively rigid and structurally stable, together with highly flexible segments exhibiting substantial conformational plasticity. These rigidity-flexibility features constitute an essential structural basis enabling TCRs to recognize diverse peptide-MHC ligands and to accommodate conformational heterogeneity at the interface. However, many current modeling tools, in an effort to enforce global conformational stability or reduce structural noise, tend to over-constrain intrinsically flexible regions. Such oversimplification may lead to inappropriate rigidification of flexible CDR loops, resulting in local structural distortions, compromised interface geometry, or even complete modeling failure for specific complexes. Against this background, the review approaches the field from the perspective of computational differences between MHC-I and MHC-II complexes. We first systematically organize and summarize available resources related to TCRs and pMHCs, including structural datasets, sequence databases, prediction tools, and benchmarking studies. We then focus on five representative tools capable of predicting both class I and class II complexes—AlphaFold2, AlphaFold3, TCRmodel2, tFold-TCR, and TCR-pHLA_ModellerS. After excluding structures present in the training sets of these tools, we constructed a benchmark dataset comprising 25 class I and 10 class II TCR-pMHC complexes in the bound state and conducted a systematic evaluation using this dataset. We first employ widely used general evaluation metrics, including All-Atom Root Mean Square Deviation (All-Atom RMSD), Backbone RMSD, Template Modeling score (TM-score), and DockQ, to assess the global conformational accuracy and interface modeling quality of class I and class II complexes. For class II complexes, we propose for the first time a peptide flanking residue deviation index, including the PFRs-Deviation Index (PFRs-DI), N-PFR-Deviation Index (N-PFR-DI), and C-PFR-Deviation Index (C-PFR-DI), to quantitatively characterize conformational deviations in PFRs. In addition, we propose the CDR conformational consistency index (CCC) designed to qualitatively evaluate the ability of prediction tools to capture TCR CDR conformational flexibility. These metrics collectively assess a tool’s ability to model both overall conformation and critical functional regions, thereby addressing the limitations of existing evaluation criteria that overemphasize global structure while inadequately capturing modeling quality in key functional areas. This establishes a unified analytical framework for MHC-I and MHC-II complexes to guide data resource selection, modeling strategy formulation, and evaluation system development. The framework further advances computational modeling and provides crucial support for multi-scale analysis of TCR-pMHC recognition mechanisms and their biological functions.