BACKGROUND:One of the advantages of clear aligner treatment is molar distalization.However,tooth tilting movement and loss of anterior anchorage may occur during treatment.There are few studies on whether these problems can be improved by selecting clear aligners with different thicknesses and edges to improve the clinical treatment effect.OBJECTIVE:To analyze the control ability of clear aligners with different thickness and edges on the central incisor,lateral incisor,and second molar when pushing the maxillary second molar distally by three-dimensional finite element analysis.METHODS:Three-dimensional finite element analysis models of bilateral maxillary second molar distalization with clear aligner,maxillary dentition,periodontal ligament,and alveolar bone with different thicknesses and margins were established by Mimics,Geomagic Wrap,3-matic and SolidWorks software,respectively.There were 16 combinations of four thicknesses(0.4,0.5,0.625,and 0.75 mm)and four margins(scallop,straight,straight extension 2 mm and straight extension 4 mm).The data were imported into Ansys Workbench software for design and solution.The mean value,peak value and distribution of the periodontal ligament equivalent stress of the second molar,the equivalent stress and the maximum initial displacement of the second molar,and the control ability of each appliance on the second molar,central incisor,and lateral incisor were analyzed.RESULTS AND CONCLUSION:(1)The mean equivalent stress of periodontal ligament of the second molar,the equivalent stress of the second molar and the maximum initial displacement of the second molar increased with the extension of the appliance edge and the increase of the thickness of the appliance in the 16 groups of models.(2)When the thickness of appliances was the same,the maximum equivalent stress of the second molar in the linear appliance group was the highest,and the maximum equivalent stress of the second molar in the linear extended appliance group was greater than that in the scallop appliance group.When the edge of the appliance was the same,the periodontal ligament equivalent stress peak of the second molar increased with the increase of the thickness of the appliance.The equivalent stress distribution in the periodontal ligament of the second molar in the linear extendable appliance group was more uniform than that in the scallop appliance group and the linear appliance group.(3)When the thickness of the appliance was the same,the scallop-shaped appliance had the worst control on the second molar.When the edge of the appliance was the same,with the increase of the thickness of the appliance,the control of the second molar by the linear extender appliance was gradually stronger than that by the linear appliance.The control of the central incisor was stronger and more stable with the linear extended 2 mm appliance,while the control of the lateral incisor was stronger and more stable with the linear appliance.(4)The results showed that when using clear aligners to push molars distally,extending the edge of the appliance could improve the control of the molars and reduce the tilting movement of the teeth.The design of a straight extension margin of 2 mm for the central incisor and a straight edge for the lateral incisor can enhance the control of the anchorage incisor and reduce the labial inclination of the anterior teeth.

ObjectiveTo investigate the effect of lower extremity exoskeleton robots on balance and walking function of patients with post-stroke cerebellar ataxia. MethodsA total of 60 patients with post-stroke cerebellar ataxia in Beijing Bo'ai Hospital from October, 2022 to October, 2024 were selected, and randomly divided into control group (n = 30) and exoskeleton group (n = 30) randomly. Both groups were given conventional exercise training, including trunk control training, rotation axis training and Frenkel training; the exoskeleton group received additional training with lower limb exoskeleton robots, for four weeks. Before and after treatment, the Gait Watch three-dimensional gait analyzer and the Holden Functional Ambulation Classification (HFAC) were used to evaluate the walking spatiotemporal parameters such as walking speed, walking frequency and step length deviation, as well as the walking ability. Berg Balance Scale (BBS) and the International Cooperative Ataxia Rating Scale (ICARS) were used to access the balance and ataxia functions, respectively. ResultsAfter treatment, the walking speed, walking frequency and step length deviation of both groups improved (|t| > 19.676, P < 0.001), the BBS score improved (|t| > 29.032, P < 0.001), and the ICARS scores decreased (t > 33.192, P < 0.001) in both groups, and they were better in the exoskeleton group than in the control group (|t| > 2.284, P < 0.05). There was no significant difference in the improvement rate of HFAC between two groups (P > 0.05). ConclusionLower extremity exoskeleton robots can effectively improve the balance and walking function of patients with post-stroke cerebellar ataxia.

OBJECTIVE To explore a model for constructing a platform for medical institution formulation and provide insights for promoting their development. METHODS By systematically reviewing the development status and challenges of medical institution preparations in China， and based on the theory of industry-university-research collaborative innovation， the organizational structure， collaborative processes， and safeguard mechanisms of the platform were designed. RESULTS & CONCLUSIONS Medical institution formulations in China mainly faced challenges such as weak research and development （R&D） capacity， uneven quality standards， and blocked transformation pathways. This study established a full-chain， whole- industry collaborative innovation network covering the government， medical institutions， universities/research institutes， pharmaceutical enterprises， and the market， forming a new “government-industry-university-research-application” five-in-one platform model for medical institution formulations. By establishing mechanisms such as multi-entity collaborative cooperation， full- chain intellectual property management， contribution-based benefit distribution， staged risk-sharing， and third-party evaluation， the model clarified the responsibilities and collaborative pathways of all parties. The new model highlights the whole-process transformation of clinical experience-based prescriptions， enabling precise alignment between clinical needs and technological R&D， as well as between preparation achievements and industrial transformation. While breaking down the barriers of traditional platform construction， it effectively achieves optimal resource allocation and complementary advantages， addresses problems emerging in the development of medical institution preparations， and provides reference value for the formulation of relevant systems.

Oral squamous cell carcinoma (OSCC) is a common head and neck malignancy. Approximately 50% to 60% of patients with OSCC are diagnosed at a locally advanced stage (clinical staging III-IVa). Even with comprehensive and sequential treatment primarily based on surgery, the 5-year overall survival rate remains below 50%, and patients often suffer from postoperative functional impairments such as difficulties with speaking and swallowing. Programmed death receptor-1 (PD-1) inhibitors are increasingly used in the neoadjuvant treatment of locally advanced OSCC and have shown encouraging efficacy. However, clinical practice still faces key challenges, including the definition of indications, optimization of combination regimens, and standards for efficacy evaluation. Based on the latest research advances worldwide and the clinical experience of the expert group, this expert consensus systematically evaluates the application of PD-1 inhibitors in the neoadjuvant treatment of locally advanced OSCC, covering combination strategies, treatment cycles and surgical timing, efficacy assessment, use of biomarkers, management of special populations and immune related adverse events, principles for immunotherapy rechallenge, and function preservation strategies. After multiple rounds of panel discussion and through anonymous voting using the Delphi method, the following consensus statements have been formulated: 1) Neoadjuvant therapy with PD-1 inhibitors can be used preoperatively in patients with locally advanced OSCC. The preferred regimen is a PD-1 inhibitor combined with platinum based chemotherapy, administered for 2-3 cycles. 2) During the efficacy evaluation of neoadjuvant therapy, radiographic assessment should follow the dual criteria of Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 and immune RECIST (iRECIST). After surgery, systematic pathological evaluation of both the primary lesion and regional lymph nodes is required. For combination chemotherapy regimens, PD-L1 expression and combined positive score need not be used as mandatory inclusion or exclusion criteria. 3) For special populations such as the elderly (≥ 70 years), individuals with stable HIV viral load, and carriers of chronic HBV/HCV, PD-1 inhibitors may be used cautiously under the guidance of a multidisciplinary team (MDT), with close monitoring for adverse events. 4) For patients with a poor response to neoadjuvant therapy, continuation of the original treatment regimen is not recommended; the subsequent treatment plan should be adjusted promptly after MDT assessment. Organ transplant recipients and patients with active autoimmune diseases are not recommended to receive neoadjuvant PD-1 inhibitor therapy due to the high risk of immune related activation. Rechallenge is generally not advised for patients who have experienced high risk immune related adverse events such as immune mediated myocarditis, neurotoxicity, or pneumonitis. 5) For patients with a good pathological response, individualized de escalation surgery and function preservation strategies can be explored. This consensus aims to promote the standardized, safe, and precise application of neoadjuvant PD-1 inhibitor strategies in the management of locally advanced OSCC patients.

Objective: To evaluate the performance of 5T magnetic resonance imaging (MRI) in visualizing dental pulp and periodontal ligament (PDL) tissues in vivo in the young adult population, thereby providing a basis for the application of high-field MRI technology in clinical oral examinations. Methods: The study was approved by the Ethics Committee of the hospital. A total of 15 healthy volunteers (413 permanent teeth altogether) were recruited and underwent full-mouth 5T MRI scans. Among them, six volunteers (168 permanent teeth) also received both 3T MRI and cone-beam computed tomography (CBCT) scans. Two dental specialists independently evaluated the imaging quality of the dental pulp and PDL on the images using a 5-point Likert scale and recorded the number of detectable root canals for each tooth. Inter-rater agreement was assessed using weighted kappa statistics and intraclass correlation coefficient (ICC). Non-parametric tests were employed to compare differences in imaging performance among different tissue structures, tooth positions, and imaging modalities. Results: 5T MRI can achieve in vivo imaging for most dental pulp tissues and partial periodontal membrane structures. There was a high level of agreement between the two raters in their imaging scores for the dental pulp and PDL (dental pulp κ = 0.934, PDL κ = 0.737). The imaging scores for dental pulp were significantly higher than those for PDL (P < 0.001), and the scores for molar dental pulp were lower than those for premolars and anterior teeth. In the multimodal comparison involving six volunteers, the raters showed good consistency in scoring dental pulp and PDL imaging across 5T MRI, 3T MRI, and CBCT, as well as in root canal counts (5T MRI for dental pulp κ = 0.971, 3T MRI for dental pulp κ = 0.933, CBCT for dental pulp κ = 0.964; 5T MRI for PDL κ = 0.625, 3T MRI for PDL κ = 0.667, CBCT for PDL κ = 0.571; ICC for root canal counts all ≥ 0.990). The imaging scores for dental pulp and PDL using 5T MRI were significantly higher than those using 3T MRI (dental pulp: P < 0.001; PDL: P = 0.022), but there was no statistically significant difference in the detection rate of the number of root canals between the two (P > 0.05). Although the imaging scores for dental pulp and PDL as well as the detection rate of the number of root canals with 5T MRI were inferior to those with CBCT (dental pulp: P < 0.001; PDL: P = 0.02; number of root canals: P < 0.05), 5T MRI can truly achieve "direct imaging" of these two soft tissues. Conclusion 5T MRI enables effective in vivo direct imaging of dental pulp and PDL tissues in the young adult population, indicating its potential clinical application value in the diagnosis and treatment of pulp and periodontal diseases.

Large language models (LLM) are increasingly applied in the medical field, yet their clinical implementation faces numerous ethical and regulatory challenges. This paper reviews seven major ethical challenges: patient safety and accuracy, bias and fairness, privacy and data protection, transparency and explainability, accountability and legal liability, patient autonomy and informed consent, and the doctor-patient relationship and trust. At the regulatory level, international research indicates that United States currently lacks specific regulations for medical LLM use, while is exploring the regulation of high-risk LLM. The EU’s AI Act classifies medical AI as high-risk and imposes stringent compliance requirements. China has issued generative AI management measures and advocates industry standards, though its legal framework remains incomplete. Solutions include embedding ethical principles during model development, strengthening human-machine collaboration and manual oversight in clinical settings, establishing clear legal standards for accountability, safeguarding data privacy and security, implementing continuous monitoring and improvement, and deepening international cooperation and multidisciplinary governance.

Objective To preliminary explore the imaging manifestations of digital breast tomosynthesis (DBT) and contrast-enhanced mammography (CEM) in triple-negative breast cancer (TNBC) patients with different levels of human epidermal growth factor receptor 2 (HER2) expression. Methods A retrospective analysis was conducted on TNBC patients who underwent preoperative DBT or CEM examinations at Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January 2018 to December 2019 and Shanghai Second People’s Hospital from January 2022 to May 2025. Clinical data, pathological and immunohistochemical results, and imaging data were collected. Results A total of 69 TNBC patients pathologically confirmed as invasive ductal carcinoma were included, among which 34 underwent DBT and 35 underwent CEM. Among these patients, 34 (49.28%) had HER2-low expression and 35 (50.72%) had HER2-zero expression. DBT results showed that the proportion of spiculation signs in HER2-low group (n＝14) was significantly higher than that in HER2-zero group (n＝20; P＝0.009, P_adj＝0.045). However, there were no significant differences in breast density type, mass shape, or calcification between the two groups. CEM results showed that on low-energy images, the proportion of spiculation signs in the HER2-low group (n＝20) was higher than that in the HER2-zero group (n＝15; P＝0.011, P_adj＝0.077). Results of CEM showed that on reconstructed images, differences in background parenchymal enhancement and mass enhancement patterns between the two groups were not statistically significant; in both groups, heterogeneous enhancement was the most common, followed by homogeneous enhancement, with ring enhancement being the least common. Conclusions TNBC with low HER2 expression and TNBC with zero HER2 expression may have potential differences in the presentation of spiculation signs on DBT. However, the correlation between CEM manifestations and TNBC with different HER2 expression levels requires further research.

BACKGROUND:One of the advantages of clear aligner treatment is molar distalization.However,tooth tilting movement and loss of anterior anchorage may occur during treatment.There are few studies on whether these problems can be improved by selecting clear aligners with different thicknesses and edges to improve the clinical treatment effect.OBJECTIVE:To analyze the control ability of clear aligners with different thickness and edges on the central incisor,lateral incisor,and second molar when pushing the maxillary second molar distally by three-dimensional finite element analysis.METHODS:Three-dimensional finite element analysis models of bilateral maxillary second molar distalization with clear aligner,maxillary dentition,periodontal ligament,and alveolar bone with different thicknesses and margins were established by Mimics,Geomagic Wrap,3-matic and SolidWorks software,respectively.There were 16 combinations of four thicknesses(0.4,0.5,0.625,and 0.75 mm)and four margins(scallop,straight,straight extension 2 mm and straight extension 4 mm).The data were imported into Ansys Workbench software for design and solution.The mean value,peak value and distribution of the periodontal ligament equivalent stress of the second molar,the equivalent stress and the maximum initial displacement of the second molar,and the control ability of each appliance on the second molar,central incisor,and lateral incisor were analyzed.RESULTS AND CONCLUSION:(1)The mean equivalent stress of periodontal ligament of the second molar,the equivalent stress of the second molar and the maximum initial displacement of the second molar increased with the extension of the appliance edge and the increase of the thickness of the appliance in the 16 groups of models.(2)When the thickness of appliances was the same,the maximum equivalent stress of the second molar in the linear appliance group was the highest,and the maximum equivalent stress of the second molar in the linear extended appliance group was greater than that in the scallop appliance group.When the edge of the appliance was the same,the periodontal ligament equivalent stress peak of the second molar increased with the increase of the thickness of the appliance.The equivalent stress distribution in the periodontal ligament of the second molar in the linear extendable appliance group was more uniform than that in the scallop appliance group and the linear appliance group.(3)When the thickness of the appliance was the same,the scallop-shaped appliance had the worst control on the second molar.When the edge of the appliance was the same,with the increase of the thickness of the appliance,the control of the second molar by the linear extender appliance was gradually stronger than that by the linear appliance.The control of the central incisor was stronger and more stable with the linear extended 2 mm appliance,while the control of the lateral incisor was stronger and more stable with the linear appliance.(4)The results showed that when using clear aligners to push molars distally,extending the edge of the appliance could improve the control of the molars and reduce the tilting movement of the teeth.The design of a straight extension margin of 2 mm for the central incisor and a straight edge for the lateral incisor can enhance the control of the anchorage incisor and reduce the labial inclination of the anterior teeth.

BACKGROUND:The long-term patency rate of synthetic blood vessels remains a significant challenge that requires urgent attention.Enhancing the anticoagulant performance of small-caliber artificial blood vessels is crucial in ensuring their long-term efficacy.OBJECTIVE:To investigate the anticoagulation activity of polycaprolactone/low molecular weight fucoidan nanofibers with shell core structure and determine the effect on the activity of human umbilical vein endothelial cells.METHODS:Polycaprolactone nanofiber membranes and polycaprolactone/low molecular weight fucoidan nanofiber membranes with polycaprolactone as shell layer and low molecular weight fucoidan as core layer were prepared by emulsion electrospinning method(the mass ratio of low molecular weight fucoidan to polycaprolactone was 10％,25％,40％,and 55％,respectively).The morphology and structure of the fibers were characterized by scanning electron microscopy,fluorescence microscopy,and infrared spectroscopy.The mechanical strength of the fiber membranes was detected by tensile test.The loading rate and sustained release rate of low molecular weight fucoidan in the nanofibers were detected by 1,9-dimethylmethylene blue dye.The anticoagulant properties of the fiber membranes were verified by hemolysis test,dynamic coagulation test,plasma recalcification test,and platelet adhesion test.The five fiber membranes were co-cultured with human umbilical vein endothelial cells.The cell proliferation was detected by CCK-8 assay and the cell morphology was observed by fluorescence microscopy.RESULTS AND CONCLUSION:(1)Scanning electron microscope showed that the surface of polycaprolactone/low molecular weight brown algae polysaccharide nanofiber membrane was smooth,the fiber diameter was uniform,and there was no obvious beaded structure.With the increase of low molecular weight brown algae polysaccharide content in the fiber membrane,the diameter of the fiber membrane increased and the maximum tensile stress decreased,but it still met the mechanical properties requirements of small-caliber artificial blood vessels.Fluorescence images and infrared spectra confirmed that low molecular weight brown algae polysaccharide was successfully loaded into polycaprolactone nanofiber membrane,and the low molecular weight brown algae polysaccharide loaded in each group of fiber membranes was released suddenly within 12 hours and released at a relatively low rate after 48 hours.(2)Compared with polycaprolactone nanofiber membrane,polycaprolactone/low molecular weight brown algae polysaccharide nanofiber membrane had better anticoagulant activity,among which the group with a mass ratio of low molecular weight brown algae polysaccharide to polycaprolactone of 25％had the best anticoagulant effect.All five fiber membranes supported the growth and proliferation of human umbilical vein endothelial cells without affecting cell morphology and had no obvious cytotoxicity.(3)The results show that the polycaprolactone/low molecular weight brown algae polysaccharide nanofiber membrane has good anticoagulant function,blood compatibility,and cell compatibility.

BACKGROUND:The local immune microenvironment plays an important regulatory role in the process of bone formation,and the immune system is intricately linked to the skeletal system.OBJECTIVE:To systematically review the promotion of bone regeneration from three aspects:immune cell regulation of microenvironment,regulation of immune response by small extracellular vesicles,and induction of immune response by bone biomaterials,and to elucidate the immune regulatory mechanisms involved in bone regeneration.METHODS:Relevant literature was retrieved from PubMed,CNKI,WanFang Database,and VIP Database,using the search terms of"osteoimmunology,immune microenvironment,small extracellular vesicles,bone regeneration,bone tissue repair,biomaterials,and tissue engineering"in English and Chinese.Repeat and irrelevant literature was screened and removed,and 92 articles that met the criteria were selected for intensive reading and review.RESULTS AND CONCLUSION:Multiple immune cells and bone cells are in the same microenvironment,and immune cells can regulate the differentiation and activity of bone cells,collectively forming an immune microenvironment that affects bone regeneration.Neutrophils can significantly reduce local inflammatory responses in the early stages of bone injury,creating a favorable microenvironment for bone regeneration.M1 macrophages can clear foreign bodies and reduce early inflammatory responses,while M2 macrophages can promote the expression of osteogenic markers and factors,playing an important role in the repair process of bone injury.B cells and T cells can directly or indirectly affect the generation and activity of osteoblasts and osteoclasts,regulate bone metabolism,and promote bone regeneration.Extracellular vesicles of small cells regulate the local immune microenvironment through paracrine secretion,promoting bone formation and angiogenesis at the site of bone injury.The metal ions,surface hydrophilicity,porosity,pore size,surface morphology,and surface roughness on the surface of biomaterials can directly regulate local immune responses,and have anti-inflammatory,angiogenic,and osteogenic effects,thereby accelerating bone regeneration.