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 explore the effects of vitamin D on anxiety and depression behavior and the mechanism of hippocampal inflammation in obese rats.Methods Male Wistar rats were randomly divided into 4 groups(n=12):control group(group C),obesity group(group F),low-dose vitamin D group(L-VD group),and high-dose vitamin D group(H-VD group).Group C was fed a standard diet,and the other three groups were fed a high-fat diet.After successful establishment of the rat obesity model,L-VD group and H-VD group were intraperitoneally injected with 10 μg·kg-1·d-1 and 20 μg·kg-1·d-1 vitamin D,respective-ly,and groups C and F were injected with the same volume of normal saline;relevant indexes were detected af-ter continued feeding for 6 weeks.The sucrose preference test and open field test were used to study the be-havior of rats in each group.The histopathological changes of hippocampal tissue were observed by HE stai-ning.The expression levels of TNF-α and NF-κB protein in hippocampal tissue were detected by Western blot.Results After 6 weeks of intervention,compared with group C,the serum 25(OH)D concentration,sugar-wa-ter preference rate,total distance of open field movement,number of entries into the central area,and duration of stay in the central area were significantly decreased in group F rats.The expression levels of TNF-α and NF-κB proteins in hippocampal tissues were significantly increased(P<0.05).Compared with group F,serum 25(OH)D concentration and sugar-water preference rate were significantly increased in L-VD and H-VD groups.Anxiety and depression-like behaviors in the open field were markedly improved.TNF-α and NF-κB protein levels were significantly decreased(P<0.05).Statistically significant differences were observed in all aforementioned indicators between the groups(P<0.05).HE staining revealed looser arrangement of hipp-ocampal neurons,with extensive neuronal degeneration in group F.In contrast,L-VD and H-VD groups exhib-ited tighter and more regular neuronal arrangements,with only mild edema and cytoplasmic vacuolation in some cells.No significant neuronal degeneration was observed in the H-VD group.Conclusion Reduced vita-min D levels in obese rats exacerbate anxiety-depression-like behaviors,potentially through activation of hipp-ocampal inflammatory factors.

Arson is classified as a violent crime,and often involves accelerants that significantly increase casualties and property damage.These accelerants,typically flammable liquids with low saturated vapor pressure,present volatile characteristic components in fire residues,making evidence preservation critical for accurate forensic analysis.In this study,the preservation performance of AMPAC(American KAPAC polyester sampling bags)and polyethylene(PE)evidence bags were evaluated under simulated field conditions(40 oC)through gas chromatography-mass spectrometry(GC-MS)technique,focusing on background interference,sealing integrity,and cross-contamination.The results demonstrated that AMPAC bags exhibited minimal background interference(C12?C14 alkanes detected after 3?7 days)and effective gasoline sealing,though slight losses of C2?C3 alkylbenzenes and trace cross-contamination were observed.In contrast,PE bags showed significant background hydrocarbons(C15?C19 alkanes)and pronounced gasoline component losses,including C2?C4 alkylbenzenes,naphthalenes,and indenes.Notably,severe cross-contamination of gasoline markers was detected in adjacent blank PE bags,with characteristic components such as C2?C4 alkylbenzenes,naphthalenes,methylnaphthalenes,dimethylnaphthalenes,indenes,indanes,methylindenes,and dimethylindenes identified,indicating substantial cross-contamination issues in PE evidence bags.Microstructural analysis revealed superior sealing in AMPAC bags attributed to their smooth,dense surface morphology compared to PE's rougher,porous structure.This study established a comprehensive evaluation framework for fire residue evidence containers,and found that PE bags were unsuitable for long-term gasoline evidence preservation due to compromised integrity.These findings provided critical references for forensic container selection in fire investigations.

The stability of ammonium ion selective electrode is an important indicator to ensure accurate monitoring of ammonia nitrogen concentration in drinking water.However,in long-term monitoring process,interfering ions and water molecules in water samples may penetrate into the interior of the ammonium ion selective electrode to form a water layer,which affects the potential response and stability of the electrode.Perfluorooctanoic acid is a low surface energy material,and doping it in polyaniline can reduce surface energy of the composite and improve surface roughness.In this work,five ammonium ion selective electrodes were prepared by doping polyaniline with different concentrations of perfluorooctanoic acid as a solid contact layer,which made the solid contact layer of electrode had hydrophobic properties,thereby improving stability of the ammonium ion selective electrode.The stability of the ion-selective electrode was evaluated by potential drift experiment,and the optimal doping concentration of perfluorooctanoic acid in the sediment solution was determined to be 5 mmol/L.The experiment results showed that the solid contact layer had a water contact angle of 132o under the doping concentration,the potential drift rate was 41.66 μV/h,and potential drift rate in the aqueous layer test was 1.31 mV/h,which were all better than those of the unmodified electrode.The standard deviation of the electrode potential was 1.42 mV,which was obviously superior to that of the unmodified electrode.The characteristics of high stability of the electrode made it suitable for long-term monitoring of ammonia nitrogen content in water samples.

Chronic kidney disease(CKD)is a chronic disease characterized by renal structural damage and dysfunction.At present,there is still a lack of effective therapeutic drugs and prevention and treatment methods for CKD in clinical practice.More and more studies have shown that necroptosis,as a new type of programmed cell death,plays a vital role in the onset and progression of CKD.Targeting key molecules in the necroptosis pathway,such as RIPK1,RIPK3 and MLKL,the development of small molecule inhibitors has become an emerging strategy for the treatment of CKD,and has shown significant potential to pro-tect the kidneys and alleviate renal fibrosis in a variety of in vitro and in vivo models.Therefore,this article summarizes the re-search progress of the mechanism of necroptosis in recent years,and focuses on the potential role of necroptosis in the pathogene-sis of CKD and the therapeutic potential of targeting this path-way,providing a new perspective and research direction for the prevention and treatment of CKD in the future.

BACKGROUND:Exosomes have been confirmed to be closely related to cartilage degeneration in osteoarthritis.However,the role and mechanism of exosome-derived genes in cartilage degeneration of osteoarthritis have not been fully elucidated.OBJECTIVE:Bioinformatics analyses were used to screen the genes related to cartilage degeneration in the synovial exosomes of patients with osteoarthritis,and to determine their biological functions and signaling pathways in order to provide new therapeutic targets for delaying cartilage degeneration in osteoarthritis.METHODS:Firstly,osteoarthritis-related exosome dataset GSE185059 and cartilage degeneration dataset GSE114007 were downloaded from Gene Expression Omnibus(GEO)database to screen exosome-derived cartilage degeneration related genes.GO functional and KEGG pathway enrichment analyses were performed based on the screened exosome-derived cartilage degeneration related genes.Protein-protein interaction network was drawn and Ingenuity Pathway Analysis(IPA)was conducted to screen and obtain key exosome-derived cartilage degeneration-related genes.Finally,qRT-PCR was used to verify the expression of key genes in osteoarthritis cartilage tissue and interleukin-1β stimulated chondrocyte models.RESULTS AND CONCLUSION:(1)There were 831 differentially expressed genes in the GSE185059 dataset and 5 323 differentially expressed genes in the GSE114007 dataset.A total of 94 exosome-derived cartilage degeneration related genes were screened after the intersection of these differentially expressed genes,of which 51 genes were down-regulated and 43 genes were up-regulated.(2)GO functional enrichment analysis showed that the up-regulated genes were mainly involved in the positive regulation of cell-cell adhesion,the positive regulation of T cell activation,and chronic inflammatory response,while the down-regulated genes were mainly involved in biological processes such as cell aggregation,cartilage differentiation and development,and skeletal system morphogenesis.(3)KEGG pathway enrichment analysis showed that exosome-derived cartilage degeneration-related genes were mainly involved in tryptophan enrichment metabolism,vitamin B6 metabolism,and leukocyte transendothelial migration.(4)The constructed protein-protein interaction network confirmed the existence of multiple interaction relationships among exosome-derived cartilage degeneration-related genes.Combined with five algorithms in CytoHubba software,four key exosome-derived cartilage degeneration-related genes were further screened,namely THY1,CYP1A1,NFKB2,and COL6A3.(5)The results of qRT-PCR showed that compared with normal cartilage,the expressions of THY1 and COL6A3 in osteoarthritic cartilage were increased,while the expression of CYP1A1 and NFKB2 was decreased.Similarly,compared with the unstimulated group,the expression of THY1 and COL6A3 in the interleukin-1β induced chondrocytes was upregulated,while the expression of CYP1A1 and NFKB2 was downregulated.(6)These results indicate that THY1,CYP1A1,NFKB2,and COL6A3 are genes related to cartilage degeneration in the exosomes of synovial fluid of patients with osteoarthritis,and may participate in the pathogenesis of osteoarthritis by regulating biological processes such as protein tyrosine kinase activity and lipid metabolism,as well as nuclear factor-κB signaling pathway and focal adhesion signaling pathway.However,the specific regulatory roles and molecular mechanisms of these key genes in cartilage degeneration need to be further verified by experiments.

AIM:To investigate the mechanism by which muscle segment homeobox 2(Msx2)regulates the differentiation of outer enamel epithelial cells in the enamel organ.METHODS:Tissue paraffin sections were prepared and subjected to hematoxylin-eosin(HE)staining to analyze the effect of Msx2 deficiency on the differentiation status of epithelial cells in the enamel organ at the morphological level.At the ultrastructural level,alterations in cell structure were analyzed.The intermediate steps mediating cell differentiation were identified.Transcriptome sequencing analysis was performed to validate the molecular mechanisms underlying the observed phenomena.RESULTS:Msx2 deficiency was innovatively found to induce severe squamous epithelial hyperplasia in outer enamel epithelial cells of enamel organ,accompanied by dynamic restructuring of the cell cytoskeleton and alterations in cell adhesion at the ultrastructure level.As a transcriptional repressor,the loss of Msx2 expression results in significant increases(P＜0.05 or P＜0.01)in the mRNA expression levels of integrin β2(Itgβ2),ItgαM,Itgα4,Rac family small GTPase 2(Rac2),Rac/Cdc42 guanine nucleo-tide exchange factor 6(Arhgef6)and protein tyrosine phosphatase receptor type C(Ptprc).CONCLUSION:Msx2 regu-lates cytoskeleton structure and cell-cell interaction through the Rho GTPases signaling pathway,thereby influencing the differentiation state of outer enamel epithelial cells.This study reveals the mechanism through which Msx2 regulates the differentiation of outer enamel epithelial cells,providing a theoretical foundation for the prevention and treatment of enam-el-related clinical dental diseases.

The scientific research and innovation capabilities of medical students are intrinsically linked to the sustained and high-quality development of national healthcare initiatives.Cultivating outstanding medi-cal students with independent scientific capabilities and innovative consciousness is a critical component in the education and training of high-level medical professionals.Our investigation revealed that within the imperfections of the cultivating model,some faculty and students at medical schools have an insufficient understanding of scientific research and innovation and lack motivation for engaging in such activities,which hinder the progression of scientific research activities.Consequently,we initiated a teaching practice and exploratory study on the"tutorial system"aimed at fostering medical students'scientific research and innovation abilities.Based on the principle of"research informing teaching,teaching and research advan-cing together,"this study implements a"tutorial system"coordinated by tutors,supplemented by graduate and undergraduate student mentors,to cultivate innovative thinking,stimulate interest in scientific re-search,and enhance practical and research skills among medical students.Through collaborative efforts within"scientific research innovation teams,"various educational methods—including preliminary re-search,in-class and extracurricular activities,intra-group and inter-group interactions,and theoretical and practical applications—are employed to improve and strengthen the cultivation of medical students'scientif-ic research and innovation abilities.This study aims to provide valuable references for optimizing medical education management systems and enhancing the quality of medical student training.

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract, which increases the incidence of colorectal cancer (CRC). In the pathophysiology of IBD, ubiquitination/deubiquitination plays a critical regulatory function. Josephin domain containing 2 (JOSD2), a deubiquitinating enzyme, controls cell proliferation and carcinogenesis. However, its role in IBD remains unknown. Colitis mice model developed by dextran sodium sulfate (DSS) or colon tissues from individuals with ulcerative colitis and Crohn's disease showed a significant upregulation of JOSD2 expression in the macrophages. JOSD2 deficiency exacerbated the phenotypes of DSS-induced colitis by enhancing colon inflammation. DSS-challenged mice with myeloid-specific JOSD2 deletion developed severe colitis after bone marrow transplantation. Mechanistically, JOSD2 binds to the C-terminal of inosine-5'-monophosphate dehydrogenase 2 (IMPDH2) and preferentially cleaves K63-linked polyubiquitin chains at the K134 site, suppressing IMPDH2 activity and preventing activation of nuclear factor kappa B (NF-κB) and inflammation in macrophages. It was also shown that JOSD2 knockout significantly exacerbated increased azoxymethane (AOM)/DSS-induced CRC, and AAV6-mediated JOSD2 overexpression in macrophages prevented the development of colitis in mice. These outcomes reveal a novel role for JOSD2 in colitis through deubiquitinating IMPDH2, suggesting that targeting JOSD2 is a potential strategy for treating IBD.

Ovarian tumor (OT) is the most lethal form of gynecologic malignancy, with minimal improvements in patient outcomes over the past several decades. Metastasis is the leading cause of ovarian cancer-related deaths, yet the underlying mechanisms remain poorly understood. Psychological stress is known to activate the glucocorticoid receptor (NR3C1), a factor associated with poor prognosis in OT patients. However, the precise mechanisms linking NR3C1 signaling and metastasis have yet to be fully elucidated. In this study, we demonstrate that chronic restraint stress accelerates epithelial-mesenchymal transition (EMT) and metastasis in OT through an NR3C1-dependent mechanism involving nuclear protein 1 (NUPR1). Mechanistically, NR3C1 directly regulates the transcription of NUPR1, which in turn increases the expression of snail family transcriptional repressor 2 (SNAI2), a key driver of EMT. Clinically, elevated NR3C1 positively correlates with NUPR1 expression in OT patients, and both are positively associated with poorer prognosis. Overall, our study identified the NR3C1/NUPR1 axis as a critical regulatory pathway in psychological stress-induced OT metastasis, suggesting a potential therapeutic target for intervention in OT metastasis.