Electromagnetic fields can regulate the fundamental biological processes involved in bone remodeling. As a non-invasive physical therapy, electromagnetic fields with specific parameters have demonstrated therapeutic effects on bone remodeling diseases, such as fractures and osteoporosis. Electromagnetic fields can be generated by the movement of charged particles or induced by varying currents. Based on whether the strength and direction of the electric field change over time, electromagnetic fields can be classified into static and time-varying fields. The treatment of bone remodeling diseases with static magnetic fields primarily focuses on fractures, often using magnetic splints to immobilize the fracture site while studying the effects of static magnetic fields on bone healing. However, there has been relatively little research on the prevention and treatment of osteoporosis using static magnetic fields. Pulsed electromagnetic fields, a type of time-varying field, have been widely used in clinical studies for treating fractures, osteoporosis, and non-union. However, current clinical applications are limited to low-frequency, and research on the relationship between frequency and biological effects remains insufficient. We believe that different types of electromagnetic fields acting on bone can induce various “secondary physical quantities”, such as magnetism, force, electricity, acoustics, and thermal energy, which can stimulate bone cells either individually or simultaneously. Bone cells possess specific electromagnetic properties, and in a static magnetic field, the presence of a magnetic field gradient can exert a certain magnetism on the bone tissue, leading to observable effects. In a time-varying magnetic field, the charged particles within the bone experience varying Lorentz forces, causing vibrations and generating acoustic effects. Additionally, as the frequency of the time-varying field increases, induced currents or potentials can be generated within the bone, leading to electrical effects. When the frequency and power exceed a certain threshold, electromagnetic energy can be converted into thermal energy, producing thermal effects. In summary, external electromagnetic fields with different characteristics can generate multiple physical quantities within biological tissues, such as magnetic, electric, mechanical, acoustic, and thermal effects. These physical quantities may also interact and couple with each other, stimulating the biological tissues in a combined or composite manner, thereby producing biological effects. This understanding is key to elucidating the electromagnetic mechanisms of how electromagnetic fields influence biological tissues. In the study of electromagnetic fields for bone remodeling diseases, attention should be paid to the biological effects of bone remodeling under different electromagnetic wave characteristics. This includes exploring innovative electromagnetic source technologies applicable to bone remodeling, identifying safe and effective electromagnetic field parameters, and combining basic research with technological invention to develop scientifically grounded, advanced key technologies for innovative electromagnetic treatment devices targeting bone remodeling diseases. In conclusion, electromagnetic fields and multiple physical factors have the potential to prevent and treat bone remodeling diseases, and have significant application prospects.

Objective: To analyze the temporal variation patterns of sickness absenteeism among primary and secondary school students in Shanghai, so as to explore models suitable for predicting peaks and intensity of absenteeism rates. Methods: The seasonal and trend decomposition using loess (STL) method was used to analyze the seasonal and long term trend changes in sickness absenteeism among primary and secondary school students from September 1 in 2010 to June 30 in 2018, in Shanghai. A hierarchical clustering method based on Dynamic Time Warping (DTW) was employed to classify absenteeism symptoms with similar temporal patterns. Based on historical data, the study constructed and evaluated different time series algorithms and machine learning models to optimize the accuracy of predicting the trend of sickness absenteeism. Results: During the research period, the average new absenteeism rate due to illness was 16.86 per 10 000 person day for every academic year, and the trend of sickness absenteeism exhibited both seasonality and a long term upward trend, reaching its highest point in the 2017 academic year (22.47 per 10 000 person day). The symptoms of absenteeism were divided into three categories: high incidence in winter and spring (respiratory symptoms, fever and general discomfort, etc.), high incidence in summer (eye symptoms, nosebleeds, etc.) and those without obvious seasonality (skin symptoms, accidental injuries, etc.).The constructed time series models effectively predicted the trend of absenteeism due to illness, although the accuracy of predicting peak intensity was relatively low. Among them, the multi layer perceptron (MLP) model performed the best, with an root mean squared error (RMSE) of 8.96 and an mean absolute error (MAE) of 4.37, reducing 36.51% and 39.02% compared to the baseline model. Conclusion Time series models and machine learning algorithms could effectively predict the trend of sickness absenteeism, and corresponding prevention and control measures can be taken for absenteeism caused by different symptoms during peak periods.

Objective     To investigate the relationship between preoperative mean daily step counts and pulmonary complications after thoracoscopic lobectomy in elderly patients. Methods     From 2018 to 2021, the elderly patients with pulmonary complications after thoracoscopic lobectomy were included. A 1∶1 propensity score matching was performed with patients without pulmonary complications. The clinical data were compared between the two groups. Results    Totally, 100 elderly patients with pulmonary complications were enrolled, including 78 males and 22 females, aged 66.4±4.5 years. And 100 patients without pulmonary complications were matched, including 71 males and 29 females aged 66.2±5.0 years. There was no significant difference in the preoperative data between the two groups (P>0.05). Compared to the patients with pulmonary complications, the ICU stay was shorter (8.1±4.4 h vs. 12.9±7.5 h, P<0.001), the first out-of-bed activity time was earlier (8.8±4.5 h vs. 11.2±6.1 h, P=0.002), and the tube incubation time was shorter (19.3±9.2 h vs. 22.5±9.4 h, P=0.015) in the patients wihout pulmonary complications. There was no statistical difference in other perioperative data between the two groups (P>0.05). The mean daily step counts in the pulmonary complications group were significantly less than that in the non-pulmonary complications group (4 745.5±2 190.9 steps vs. 6 821.1± 2 542.0 steps, P<0.001). The daily step counts showed an upward trend for three consecutive days in the two groups, but the difference was not significant. Conclusion     The decline of preoperative mean daily step counts is related to pulmonary complications after thoracoscopic lobectomy in elderly patients. Recording daily step counts can promote preoperative active exercise training for hospitalized patients.

BACKGROUND:Increasing evidence suggests that N6-methyladenosine(m6A)regulators are closely associated with osteoarthritis and are considered to be a new direction in the prevention and treatment of osteoarthritis,but their specific mechanism of action is unknown. OBJECTIVE:To conduct a bioinformatics analysis of the osteoarthritis gene microarray dataset in order to explore the role of m6A in osteoarthritis and analyze the pathogenesis of osteoarthritis. METHODS:The m6A regulators associated with osteoarthritis and their expression were first extracted from the GSE1919 dataset in the GEO database using R software,and then the results were analyzed by gene difference analysis and GO and KEGG enrichment analyses.Subsequently,the results of protein-protein interaction network topology analysis and machine learning results were intersected to obtain the m6A Hub regulators,which were validated by in vitro cellular experiments. RESULTS AND CONCLUSION:A total of 16 osteoarthritis-related m6A regulators were extracted and 11 m6A differential regulators,including ZC3H13,YTHDC1,YTHDF3 and HNRNPC,were obtained by differential analysis.GO enrichment analysis showed that osteoarthritis-related m6A differential regulators played a role in the biological processes such as mRNA transport,RNA catabolism,and regulation of insulin-like growth factor receptor signaling pathway.(3)KEGG enrichment analysis showed that the differential regulators were mainly involved in the p53,interleukin-17 and AMPK signaling pathways.The combined protein-protein interaction network topology analysis and machine learning results obtained the m6A Hub regulator-YTHDC1.(5)The results of in vitro cellular experiments showed that there was a significant difference in the expression of m6A key regulator between the control and experimental groups(P<0.05).To conclude,YTHDC1 is closely related to the development of osteoarthritis,which is expected to be a molecular target of m6A for the treatment of osteoarthritis.

Objective To explore the efficacy and safety of recombinant human anti-severe acute respiratory syn-drome coronavirus 2(anti-SARS-CoV-2)monoclonal antibody injection(F61 injection)in the treatment of patients with coronavirus disease 2019(COVID-19)combined with renal damage.Methods Patients with COVID-19 and renal damage who visited the PLA General Hospital from January to February 2023 were selected.Subjects were randomly divided into two groups.Control group was treated with conventional anti-COVID-19 therapy,while trial group was treated with conventional anti-COVID-19 therapy combined with F61 injection.A 15-day follow-up was conducted after drug administration.Clinical symptoms,laboratory tests,electrocardiogram,and chest CT of pa-tients were performed to analyze the efficacy and safety of F61 injection.Results Twelve subjects(7 in trial group and 5 in control group)were included in study.Neither group had any clinical progression or death cases.The ave-rage time for negative conversion of nucleic acid of SARS-CoV-2 in control group and trial group were 3.2 days and 1.57 days(P=0.046),respectively.The scores of COVID-19 related target symptom in the trial group on the 3rd and 5th day after medication were both lower than those of the control group(both P＜0.05).According to the clinical staging and World Health Organization 10-point graded disease progression scale,both groups of subjects improved but didn't show statistical differences(P＞0.05).For safety,trial group didn't present any infusion-re-lated adverse event.Subjects in both groups demonstrated varying degrees of elevated blood glucose,elevated urine glucose,elevated urobilinogen,positive urine casts,and cardiac arrhythmia,but the differences were not statistica-lly significant(all P＞0.05).Conclusion F61 injection has initially demonstrated safety and clinical benefit in trea-ting patients with COVID-19 combined with renal damage.As the domestically produced drug,it has good clinical accessibility and may provide more options for clinical practice.

Objective:To study the clinical safety and validity of retrograde new endoscopic field of vision in miniature pigs.Methods:6 live miniature pigs were selected as study subjects,En-doscopic Retrograde New View(ERNV)was selected.The performance,image quality and intraoper-ative and postoperative complications were evaluated.To evaluate whether all the experimental ani-mals could complete the relevant endoscopy.Verify ERNV's operating performance,including whether the duodenoscope can enter the biliary tract smoothly,and made sure whether the injection,suction,and instrument channels were unobstructed.Choledochoscope image clarity,color resolu-tion,image deformation and distortion,accurate evaluation of lumen conditions and clear observation of mucosal surface conditions were analyzed.Whether there were operant injuries such as bleeding and perforation,as well as adverse events such as respiratory depression and cardiac arrest.The sur-vival status and adverse reactions of all pigs were observed.Results:The choledochoscope was successfully inserted into the bile duct of 6 miniature pigs.The product had good operation perfor-mance and could enter the bile duct through the duodenoscope smoothly.The injection,suction and instrument channels were relatively smooth.In addition,the endoscopic images are clear,with better color resolution,and without image deformation and distortion,which can realize accurate evaluation of the conditions in the lumen and observe the mucosal surface conditions more clearly.No bile duct stenosis or dilatation occurred in all miniature pigs,and the bile duct mucosa was smooth,without hyperemia and edema,and no abnormal thickening or bending of mucous vessels.During the exami-nation,there were no operational injuries such as bleeding and perforation,and no adverse events such as respiratory depression and cardiac arrest occurred.The vital signs of all miniature pigs tended to be stable after operation,and the survival state was good,and there were no complications such as cholangitis,bleeding and perforation.Conclusion:ERNV has good clinical safety and efficacy,ex-cellent operation performance and excellent image quality,and is worthy of clinical application.

Ankylosing spondylitis (AS) combined with lower cervical fracture is often categorized into unstable fracture, with a high incidence of neurological injury and a high rate of disability and morbidity. As factors such as shoulder occlusion may affect the accuracy of X-ray imaging diagnosis, it is often easily misdiagnosed at the primary diagnosis. Non-operative treatment has complications such as bone nonunion and the possibility of secondary neurological damage, while the timing, access and choice of surgical treatment are still controversial. Currently, there are no clinical practice guidelines for the treatment of AS combined with lower cervical fracture with or without dislocation. To this end, the Spinal Trauma Group of Orthopedics Branch of Chinese Medical Doctor Association organized experts to formulate Clinical guidelines for the treatment of ankylosing spondylitis combined with lower cervical fracture in adults ( version 2024) in accordance with the principles of evidence-based medicine, scientificity and practicality, in which 11 recommendations were put forward in terms of the diagnosis, imaging evaluation, typing and treatment, etc, to provide guidance for the diagnosis and treatment of AS combined with lower cervical fracture.

BACKGROUND:Cellular senescence is closely related to the development and progression of osteoarthritis,but the specific targets and regulatory mechanisms are not yet clear. OBJECTIVE:To mine key genes in cellular senescence-mediated osteoarthritis by integrating bioinformatics and machine learning approaches and validate them via experiments to explore the role of cellular senescence in osteoarthritis. METHODS:The osteoarthritis gene expression profiles obtained from the GEO database were intersected with cellular senescence-related genes obtained from the CellAge database and the expression of the intersected genes was extracted for differential analysis,followed by GO and KEGG analysis of the differential genes.The key osteoarthritis cellular senescence genes were then screened by protein-protein interaction network analysis and machine learning,and in vitro cellular experiments were performed.Finally,the expression of the key genes was detected by qPCR. RESULTS AND CONCLUSION:A total of 31 osteoarthritis cell senescence differential genes were identified.GO analysis showed that these genes were mainly involved in the biological processes,such as regulation of leukocyte differentiation,monocyte differentiation,regulation of T cell differentiation and exerted roles in DNA transcription factor binding,histone deacetylase binding,chromatin DNA binding,and chemokine binding.KEGG analysis showed that osteoarthritis cell senescence differential genes were mainly activated in the JAK/STAT signaling pathway,PI3K/Akt signaling pathway and FoxO signaling pathway.MYC,a key gene for osteoarthritis cellular senescence,was identified by protein-protein interaction network topology analysis and machine learning methods.The results of the in vitro cellular assay showed that the mRNA expression of MYC was significantly lower in the experimental group(osteoarthritis group)than the control group(normal group)(P＜0.05).To conclude,MYC can be a key gene in the senescence of osteoarthritic cells and may be a new target in the prevention and treatment of osteoarthritis by mediating immune response,inflammatory response and transcriptional regulation.

Objective To compare clinical effect between open reduction and fixation with cannulated screw and threaded rivet via posteromedial approach versus arthroscopic Endobutton plate fixation in treating posterior cruciate ligament avulsion fractures.Methods Clinical data of 38 patients with posterior cruciate ligament avulsion fractures from July 2020 to December 2021 were analyzed retrospectively,and divided into open reduction and internal fixation group(posterior medial approach hollow anchor system fixation)and arthroscopic fixation group(Endobutton with loop plate fixation under arthroscopy).There were 20 patients in open reduction and internal fixation group,including 16 males and 4 females,aged from 26 to 74 years old with an average of(42.9±18.8)years old;13 patients on the left side and 7 patients on the right side;12 patients were classi-fied to type Ⅱ and 8 patiens with type Ⅲ according to Meyers-McKeever fractures classification;14 patients were grade Ⅱ and 6 patients were grade Ⅲ in back drawer test.There were 18 patients in arthroscopic fixation group,including 11 males and 7 fe-males;aged from 24 to 70 years old with an average of(53.5±13.4)years old;11 patients on the left side and 7 patients on the right side;10 patients were classified to type Ⅱ and 8 patiens with type Ⅲ according to Meyers-McKeever fractures classifica-tion;11 patients were grade Ⅱ and 7 patients were grade Ⅲ in back drawer test.Operation time,blood loss,and quality of im-mediate reduction were compared between two groups.Knee range of motion,knee back drawer test,and International Knee Documentation Committee(IKDC)grading,KT2000 stability evaluation and Lysholm function score of knee joint were com-pared at 6 months after operation.Results All patients were followed up for 8 to 16 months with an average of(12.3±1.9)months.There were no complications such as incision infection,fracture malunion or non-union,and internal fixation loosening occurred.The avulsion fractures of knee joint were reached to imaging healing standard at 6 months after operation.Operation time and blood loss in open reduction and internal fixation group were(56.4±7.1)min and(63.2±10.2)ml,while(89.9±7.4)min and(27.7±8.7)ml in arthroscopic fixation group,respectively,and had significant difference between two groups(P＜0.05).There were no differences in immediate reduction quality(x2=0.257,P=0.612),knee joint range of motion at 6 months after opertaion(t=0.492,P=0.626),knee joint rear drawer test(x2=0.320,P=0.572),IKDC classification of knee joint(x2=0.127,P=0.938),KT2000stability evaluation(x2=0.070,P=0.791),and knee Lysholmfunction score(t=0.092,P=0.282)between two groups.Conclusion Posterior medial approach with hollow anchoring system fixation and arthroscopic Endobutton with loop plate fixa-tion for the treatment of posterior cruciate ligament tibial occlusion avulsion fracture could achieve satisfactory clinical results,and arthroscopic surgery has less bleeding,but also has a longer learning curve and longer operation time than traditional inci-sion surgery.The surgeon needs to make a choice according to clinical situation of patient and their own surgical inclination.

Objectives:To investigate the clinical feasibility of three-dimensional(3D)high-resolution late gadolinium enhancement(LGE)MRI in accessing left atrial myocardial fibrosis in patients with atrial fibrillation(AF). Methods:A total of 34 AF patients referred for hybrid surgical ablation were retrospectively enrolled in this study.3D-LGE-MRI images were acquired by Siemens 3.0 T machine and analyzed by ADAS post-processing software by two experienced radiologists to obtain parameters such as the area and the area percentage of LGE.Regional analysis was performed by one of the two radiologists at ten left atrial segments.The Kappa test was used to assess the agreement for scoring image quality,and the interclass correlation coefficient(ICC)was used to evaluate the interobserver agreement of LGE parameters.The parameters of left atrial morphology,area(and area percentage)of LGE,and location of LGE were compared between patients with persistent AF and paroxysmal AF. Results:Images of all 34 patients were considered to have diagnostic value.The scores of the overall image quality and the clarity of the left atrial wall evaluated by two radiologists were(2.88±0.64)points and(3.26±0.75)points(radiologist 1),(2.97±0.58)points and(3.24±0.70)points(radiologist 2),respectively.The corresponding Kappa values were 0.724 and 0.859.Both the area and the area percentage of LGE showed good consistency among observers,and the ICCs were 0.969 and 0.950,respectively.The difference in the area of LGE and the area percentage of LGE between patients with paroxysmal and persistent atrial fibrillation was similar(both P＞0.05).Compared with patients with paroxysmal AF,patients with persistent AF had a higher Utah stage and more severe myocardial fibrosis in the right inferior pulmonary vein antrum and the left atrial septum(all P＜0.05). Conclusions:3D high-resolution LGE-MRI provides a non-invasive way to visualize and quantify left atrial myocardial fibrosis.The extent of left atrial fibrosis in patients with persistent AF is more severe than that in patients with paroxysmal AF,with a preferential distribution in the right inferior pulmonary vein antrum and the left atrial septum.