Objective To analyze the clinical and therapeutic characteristics of Epstein-Barr virus (EBV)-negative posttransplant lymphoproliferative disease (PTLD) with diffuse large B-cell lymphoma (DLBCL) in the context of specific cases and literature. Methods A case of EBV-negative DLBCL (GCB type) after kidney transplantation is reported. The patient was a 45-year-old male who underwent living-related kidney transplantation in 2016 and has been receiving triple immunosuppressive therapy with tacrolimus, mycophenolate mofetil and methylprednisolone since then. In 2024, the patient presented with intermittent fever, night sweats and gastrointestinal symptoms. The diagnosis was confirmed by endoscopic pathology, immunohistochemical staining and positron emission tomography/computed tomography. The R-CDOP regimen (rituximab + cyclophosphamide + liposomal doxorubicin + vincristine + dexamethasone) was used for treatment. Results The patient was diagnosed with EBV-negative DLBCL (GCB type, Ann Arbor stage Ⅳ B). After 4 cycles of R-CDOP chemotherapy, the efficacy assessment was partial remission, and the transplant kidney function remained stable. Conclusions For EBV-negative PTLD after kidney transplantation, it is necessary to break through the "virus-dependent" diagnostic thinking. In clinical practice, the focus should be on protecting the transplant kidney, and individualized treatment plans should be developed for patients.

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.

3D printing technology plays a vital role in orthopedic teaching. This review summarizes the current applications of 3D printing technology in this field. By generating highly realistic personalized anatomical models, 3D printing overcomes the limitations associated with traditional teaching such as resource scarcity and ethical concerns, and offers a more authentic and detailed anatomical learning experience. It not only enables students to repeatedly practice in surgical simulations, thus enhancing their practical skills and confidence, but also promotes personalized teaching tailored to the diverse learning needs of students. This article reviews future development directions, aiming to provide a reference for the reform of orthopedic teaching.

As a physical treatment technique, modified electro-convulsive therapy (MECT) is used to treat mental and certain neurological disorders by causing seizures with short, suitable electrical currents applied to the brain while the patient is under general anesthesia and muscle relaxants. MECT is recognized for its therapeutic efficacy and clinical safety, rendering it one of the most prevalent interventions in psychiatric care. To enhance clinical outcomes and minimize adverse effects, this consensus document delineates the indications, therapeutic parameters, therapeutic procedures, potential adverse effects, and associated management strategies for MECT. These guidelines are informed by the latest clinical research and expert consensus, integrating evidence-based medicine methodologies. The objective is to furnish clinicians with precise operational guidelines and to advance the standardization of MECT practices in clinical settings.

Obesity is a well-established risk factor for thrombotic events such as venous thromboembolism， and the alterations in pharmacokinetics induced by obesity pose challenges for anticoagulation management. This article systematically reviews the advances of the use of various anticoagulants in obese patients， and finds that the dosage of low-molecular-weight heparin needs to be adjusted according to preventive or therapeutic goals in severely obese patients， the preventive dose may be increased to 40 mg， q12 h or 0.5 mg/（kg·d）， while the therapeutic dose is recommended to be reduced to 0.8 mg/（kg·d）， q12 h. Direct oral anticoagulant drugs are safe and effective for general obese patients； in severely obese patients， standard doses of rivaroxaban or apixaban may be used， warranting cautious application and consideration for therapeutic drug monitoring. In special clinical scenarios such as obesity combined with trauma， pregnancy， advanced age， or bariatric surgery， anticoagulation strategies should be individualized， with close attention to monitoring. Future research should focus on optimizing anticoagulant regimens for special populations and addressing anticoagulation management in obese patients with other embolic diseases.

Objective:To explore the characteristics of depression,anxiety,and stress symptoms among Chinese men who have sex with men(MSM),to determine the links of psychological resilience with these symptoms at the symptom level,and to provide insights for tailoring mental health intervention measures for MSM.Methods:A cross-sectional survey was conducted in southwestern China(Chongqing and Sichuan)from May to August 2022.The Depression,Anxiety,and Stress Scale-21 was used to assess mental health-related symptoms in MSM.Psychological resilience was evaluated using the brief version of the Connor-Davidson Resilience Scale.A regularized partial correlation network was constructed,and then a Bayesian network was established to identify potential causal rela-tionships in symptoms.A flow network was used to explore the link between psychological resilience and symptoms of anxiety,depres-sion,and stress.Results:A total of 938 MSM were included in the analysis.The proportion of MSM with depression,anxiety,and stress was 29.74%."Panic","scared","no relax",and"down-hearted"showed high expected influence.Bridging symptoms were"panic","down-hearted",and"agitated".Central and bridging symptoms also appeared at the top of the Bayesian network.Psychological resil-ience was negatively correlated with"no initiative","down-hearted","meaningless","panic",and"no relax".Conclusion:Central symptoms"panic","scared","no relax",and"down-hearted",as well as bridging symptoms"panic","down-hearted",and"agi-tated"are identified through network analysis.The potential causal priority of these symptoms is prominent.Interventions tailored to central and bridging symptoms may be effective,and interventions for enhancing psychological resilience may alleviate negative emotion-related symptoms,especially depressive symptoms in the MSM population.

Objective To analyze the characteristics of HIV-1 pretreatment drug resistance(PDR)and molecular transmission networks in Yubei District,Chongqing,providing evidence for targeted interventions.Methods Using a cross-sectional design,plasma samples were collected from HIV/AIDS patients receiving antiretroviral therapy(ART)in Yubei District from January 2022 to December 2023.Pol gene fragments were extracted and amplified for HIV-1 genotyping and drug resistance analysis.Molecular transmission networks were constructed based on genetic distance calculations.Results Among 478 HIV-1 pol sequences,eight geno-types were identified:with CRF07_BC(60.4%,289/478),CRF08_BC(15.5%,74/478),CRF01_AE(11.7%,56/478),and CRF85_BC(5.9%,28/478).The overall PDR rate was 6.3%(30/478),with resistance to nucleoside reverse transcriptase inhibitors(NRTIs)and non-nucleoside reverse transcriptase inhibitors(NNRTIs)at 1.7%(8/478)and 5.2%(25/478),respectively.No protease inhibitor(PI)resistance was de-tected.The molecular network included 177 cases(37.0%network entry rate),forming 53 clusters with 198 connections.Cluster sizes ranged from 2 to 17 nodes,and 75.3%(149/198)of connections were associated with five subdistricts/towns:Shuanglonghu Street,Huixing Street,Luoqi Town,Gulu Town,and Baoshenghu Street.Conclusion HIV-1 genotypes in Yubei District exhibit diversity and complexity,with moderate PDR prevalence.Regional clustering of transmission networks suggests the need for enhanced molecular surveil-lance and targeted interventions based on analytical findings.

Objective To investigate the impact of two different surgical methods, orthotopic kidney transplantation and abdominal heterotopic kidney transplantation, on the surgical outcomes of pig-to-pig kidney transplantation and the short-term survival of recipient pigs after surgery. Methods Twenty-four Bama miniature pigs were divided into two groups, with 12 pigs in each group, and underwent orthotopic kidney transplantation and abdominal heterotopic kidney transplantation, respectively. The perioperative indicators of the recipient pigs, renal blood perfusion, the overall incidence rate of complications and survival rate were compared between the two surgical methods. Results The total surgical time, renal artery anastomosis time, renal vein anastomosis time, cold ischemia time and total ischemia time were all shorter in the abdominal heterotopic kidney transplantation group than in the orthotopic kidney transplantation group, with statistically significant differences (all P<0.05). The number of satisfactory renal perfusion cases was higher in the abdominal heterotopic kidney transplantation group than in the orthotopic kidney transplantation group (83% vs. 75%), but the difference was not statistically significant (P>0.05). The total incidence of postoperative complications was 33% in the heterotopic kidney transplantation group, with a survival rate of 92%, and the cause of death was rupture of the vascular anastomosis. The total incidence of postoperative complications was 50% in the orthotopic kidney transplantation group, with a survival rate of 83%, and the causes of death were renal vein thrombosis and renal artery thrombosis. There were no statistically significant differences in the total incidence of postoperative complications and survival rates between the two groups (all P>0.05). Conclusions Compared with orthotopic kidney transplantation, abdominal heterotopic kidney transplantation showes better surgical outcomes in pig-to-pig kidney transplantation and is more beneficial for the short-term survival of recipient pigs after surgery. This provides experience for improving the stability of pig-to-non-human primate kidney xenotransplantation models in the future.

Objective: To investigate the impact of preschool children s aquatic motor skill (AMS) acquisition on their fundamental motor skill (FMS) development and the correlation between AMS and FMS development, so ao to provide a scientific basis for early childhood education and physical education teaching. Methods: From April to June 2024, 60 children, recruited by random sampling from a kindergarten in Taiyuan, were stratified randomly divided into an experimental group ( n =30) and a control group ( n =30). The experimental group were further divided into five classes of six each. They received AMS practice interventions twice weekly, 40 minutes per session, over eight weeks (16 sessions total) at a designated swimming center. The control group maintained their usual routine. Children s FMS and AMS were assessed pre and post intervention using the Test of Gross Motor Development-3rd (TGMD3) and Actual Aquatic Skills Test (AAST), respectively. Before and after test comparisons within and between groups employed t-tests, Wilcoxon signedrank tests, ANCOVA (including ranktransformed ANCOVA), and Cohen s d effect sizes were calculated for standardized mean differences. Spearman rank correlation was used to analyze relationships between FMS and AMS. Results: After the aquatic learning, the experimental group scored significantly higher than the control group on locomotor skills ( F=20.47, P <0.01, η 2=0.26), FMS ( F=4.59, P =0.04, η 2=0.08), and AMS ( F=109.71, P<0.01, η 2=0.79). The experimental groups improvement in locomotor skills 5.0(3.8, 7.3) versus the control group (2.8±2.5) yielded a medium effect size (Cohen s d =0.71); AMS gains in the experimental group [26.0(20.8, 28.0)] versus controls [1.0(0, 2.3)] showed a very large effect size (Cohen s d =4.73) (both P <0.01). Among preschool children, AMS acquisition was positively correlated with locomotor skills ( r =0.39) and overall FMS ( r =0.43)(both P <0.05). Skill specific assessments revealed lower proficiency in headfirst entry (immersion), treading water, and sagittalplane rotation. Conclusion Preschool children s acquisition of AMS has a positive effect on their FMS, with mutual facilitation between the two, especially in locomotor abilities.

Objective:To compare the efficacy of biplanar fixation combined with bone grafting and proximal femoral nail anti-rotation (PFNA) in the treatment of critically complicated osteoporotic intertrochanteric femoral fracture .Methods:A retrospective cohort study was conducted to analyze the clinical data of 28 patients with critically complicated osteoporotic intertrochanteric femoral fracture, admitted to Union Hospital, Tongji Medical College of Huazhong University of Science and Technology from January 2020 and December 2022, including 3 males and 25 females, aged 70-91 years [(79.4±6.3)years]. T score for bone mineral density was -2.5~-4.1 SD［（-3.3±0.6）SD］. All the patients were found with type A2.2-A3.3 fracture based on AO classification, and were complicated with trochanteric lateral wall fracture. Among them, 16 patients underwent biplanar fixation combined with bone grafting (biplanar fixation group), while 12 underwent PFNA internal fixation (PFNA group). All the patients received anti-osteoporosis therapy after surgery. The two groups were compared in terms of the operative time, intraoperative blood loss, hemoglobin levels at 3 days postoperatively, and time to weight-bearing. The visual analogue scale (VAS) scores and Harris hip scores at 1, 3, 6 months postoperatively, and at the last follow-up and the incidence of complications were also detected in the two groups.Results:All the patients were followed up for 12-16 months [(14.1±1.4)months]. In the biplanar fixation group, the operative time was (75.1±15.3)minutes, significantly longer than (45.6±14.2)minutes in the PFNA group ( P<0.01); the intraoperative blood loss was (234.1±11.8)ml, significantly more than (170.0±13.4)ml in the PFNA group ( P<0.01); the hemoglobin level at 3 days postoperatively was (82.6±9.3)g/L in the biplanar fixation group, higher than (64.8±6.8)g/L in the PFNA group ( P<0.01). The time to weight-bearing was (1.1±0.7)weeks in the biplanar fixation group, significantly shorter than (3.2±1.2)weeks in the PFNA group ( P<0.01). There were no statistically significant differences between the two groups in VAS scores and Harris hip scores at 1, 3, 6 months postoperatively, and at the last follow-up ( P>0.05). The VAS scores and Harris hip scores in the two groups were gradually improved with the prolongation of postoperative time ( P<0.05 or 0.01). No complications such as neurovascular injuries were observed in either group. One patient in the biplanar fixation group developed lower extremity deep vein thrombosis (DVT), with a complication rate of 6.3%, while 2 patients in the PFNA group developed lower extremity DVT and 4 hypostatic pneumonia, with a complication rate of 50.0% ( P<0.05). Conclusion:Compared with PFNA internal fixation, biplanar fixation with bone grafting has the advantages of less postoperative blood loss, earlier weight-bearing exercises and lower incidence of complications in the treatment of critically complicated osteoporotic intertrochanteric femoral fracture, despite longer operative time and more intraoperative blood loss.