BACKGROUND:More and more animal experiments and clinical studies have confirmed that electrical stimulation can promote the repair of peripheral nerve injury,but the specific mechanism is not yet fully understood. OBJECTIVE:To investigate the effect of electrical stimulation-induced miR-741-3p regulating Radil on Schwann cell migration. METHODS:(1)Twelve male SD rats were randomly divided into electrical stimulation group and control group.The electrical stimulation group received continuous electrical stimulation for 7 days after sciatic nerve compression injury,while the control group was not treated after sciatic nerve compression.The injured nerves were taken on day 7 after operation.The expression difference of miR-741-3p between the two groups was verified by fluorescence in situ hybridization.(2)The target genes of miR-741-3p were predicted by miRDB,TargetScan,and miRWalk databases.(3)Schwann cells were transfected with miR-741-3p mimetic and its control,miR-741-3p inhibitor and its control,Radil siRNA and its control,miR-741-3p inhibitor+Radil siRNA and miR-741-3p inhibitor+siRNA control.The transfection efficiency was detected by RT-PCR.The migration ability of Schwann cells was detected by Transwell chamber. RESULTS AND CONCLUSION:(1)The fluorescence intensity of miR-741-3p in the electrical stimulation group was lower than that in the control group.(2)The results of database prediction showed that 69 genes might be the target genes of miR-741-3p.Radil was one of the predicted target genes,which was mainly involved in cell adhesion and migration.(3)Compared with the miR-741-3p inhibitor control group,the number of Schwann cell migration increased in the miR-741-3p inhibitor group(P<0.05).Compared with the miR-741-3p mimic control group,the number of Schwann cell migration in the miR-741-3p mimic group decreased(P<0.05).Compared with the siRNA control group,the number of Schwann cell migration was decreased in the Radil siRNA group(P<0.05).(4)Compared with miR-741-3p inhibitor control group,the expression level of Radil was increased in miR-741-3p inhibitor group.Compared with miR-741-3p mimic control group,the expression level of Radil was decreased in miR-741-3p mimic group.(5)Compared with miR-741-3p inhibitor+siRNA control group,the number of Schwann cell migration was reduced in miR-741-3p inhibitor+Radil siRNA group(P<0.05).The results showed that electrical stimulation promoted the migration of Schwann cells by down-regulating miR-741-3p and targeting Radil gene.

ObjectiveTo analyze the impact of maternal postpartum depression (PPD) at 2 months postpartum on caregiving for infants aged2 to 24 months, and to provide a scientific basis for future maternal and infant healthcare services. MethodsBased on the Shanghai Maternal-Child Pairs Cohort, 1 060 mother-child pairs were selected from those fully participating in follow-up visits at 2, 6, 12, and 24 months postpartum. Pregnancy and childbirth-related information was collected using standardized questionnaire surveys and hospital obstetric and maternity records. The Edinburgh postpartum depression scale was used to assess the maternal postpartum depressive symptoms at 2 months postpartum. At 2, 6, 12, and 24 months postpartum, questionnaire survey was used to evaluate the maternal responsiveness in caregiving and the provision of early learning opportunities for infants. Scores for responsive caregiving and early learning opportunities at 2, 6, 12, and 24 months were grouped based on the 25th percentile (P₂₅) of total scores. The mixed-effects model was used to analyze the longitudinal impact of maternal postpartum depression at 2 months on the caregiving of 2 to 24-month-old infants. ResultsThe longitudinal results from the mixed-effects model did not show an impact of maternal PPD on infant responsive caregiving within 12 months and early learning opportunities within24 months. However, cross-sectional analysis revealed that, compared to the non-PPD group, the risk of low responsive caregiving at 2 months in the PPD group was 93% higher (OR=1.931, 95%CI: 1.113‒3.364, P=0.019). The risks for low provision of early learning opportunities at2 months and 24 months increased by 59% (OR=1.589, 95%CI: 1.082‒2.324, P=0.017) and 60% (OR=1.598, 95%CI:1.120‒2.279, P=0.010), respectively. ConclusionMaternal postpartum depression increases the risk of low responsive caregiving at 2 months, but its long-term effects warrant further research.

ObjectiveTo construct a rat model of psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type）， and evaluate the macroscopic manifestations and microscopic indicators of the model. MethodsTwenty-two SD rats were divided into normal group （n=3）， common psoriasis group （n=5）， spleen deficiency and dampness obstruction syndrome （external dampness type） group （n=7）， and psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group （n=7）. The spleen deficiency and dampness obstruction syndrome （external dampness type） rat model was established through 32-week exposure to an artificially simulated high-humidity environment， while the common psoriasis model was developed via 7-day topical application of imiquimod cream， and these two approaches were combined to construct a composite model of psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type）. Rats in the normal group were housed under normal humidity conditions. The general state， tongue manifestation of rats were observed to evaluate the macroscopic syndrome manifestations； the microscopic syndrome manifestations of rats were evaluated through adipose tissue and liver tissue changes； the severity of psoriasis in rats was evaluated through skin pathological changes， psoriasis area and severity index （PASI）， proliferating cell nuclear antigen （PCNA） expression and spleen tissue changes； changes in rat CD4⁺ interferon-γ⁺ cells （CD4⁺IFN-γ⁺ cells）， CD4⁺ tumour necrosis factor-α+ cells （CD4⁺ TNF-α⁺ cells）， and forkhead framing protein P3⁺ regulatory T cells （CD3⁺CD4⁺FoxP3⁺ Treg cells） were detected by flow cytometry. ResultsMacroscopically， both the spleen deficiency and dampness obstruction syndrome （external dampness type） group and psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group exhibited manifestations of spleen deficiency and dampness obstruction， including lethargy， huddling behavior， dull and disheveled fur， as well as soft or loose stools and perianal soiling in some individuals； both these two groups displayed enlarged tongue， swollen， and moist tongue texture， accompanied by slippery tongue surface. Microscopically， compared to the common psoriasis group， the psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group showed increased epididymal fat index （P＜0.05）； compared to the normal group and spleen deficiency and dampness obstruction syndrome （external dampness type） group， the psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group demonstrated significantly elevated spleen mass （P＜0.05）， while hepatic gross morphology and HE staining revealed no significant histopathological changes across all groups. Dorsal skin lesions were markedly exacerbated in the psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group when compared to those in common psoriasis group. Both the common psoriasis group and psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group exhibited significantly higher erythema scores， scaling scores， infiltration scores， PASI total scores， and proportions of CD3⁺CD4⁺FoxP3⁺Treg cells compared to the normal group and spleen deficiency and dampness obstruction syndrome （external dampness type） group （P＜0.05）， with pronounced PCNA-positive expression observed in the epidermal basal layer and dermis； the psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） group displayed significantly increased proportions of CD4⁺TNF-α⁺cells compared to the spleen deficiency and dampness obstruction syndrome （external dampness type） group （P＜0.05）； whereas no significant differences were detected in CD4⁺IFN-γ⁺cell proportions among groups （P＞0.05）. ConclusionThe rat model of psoriasis with spleen deficiency and dampness obstruction syndrome （external dampness type） can be successfully constructed by artificially simulating a high-humidity environment combined with imiquimod induction.

AIM: To investigate the risk factors of myopia, and provide evidence for the prevention and treatment of myopia in preschool children.METHODS:This is a retrospective case-control study. A total of 168 preschool-aged children(168 eyes)were enrolled from the ophthalmology department at Affiliated Hospital of Qingdao University between September 2021 and September 2023, selecting the eye with poorer vision for inclusion; the right eye was selected when both eyes had equal vision. Grouping criteria: Children with spherical equivalent(SE)>0 D and age-appropriate normal visual acuity(≥0.5 for ages 3-5; ≥0.7 for ages 6-7)were directly assigned to the non-myopia group. Children with SE <0 D underwent cycloplegic refraction after 3 days of 1% atropine sulfate gel application(three times daily). Those with SE ≤-0.50 D and failure to achieve age-normal visual acuity(<0.5 for ages 3-5; <0.7 for ages 6-7)were assigned to the myopia group, with 84 children(84 eyes)in each group. All participants underwent measurements of visual acuity, intraocular pressure, refraction, and ocular biometric parameters. Parents or guardians completed risk factor questionnaires during the visit, covering daily outdoor activity duration, daily electronic device usage/reading time, parental myopia status, maternal delivery mode, and full-term birth status.RESULTS:Significant differences were observed in uncorrected visual acuity, spherical power, SE, and axial length between the two groups of children(all P<0.05). No statistically significant differences were found in daily sleep duration, daily reading/homework time, maternal myopia status, mode of delivery, or full-term delivery status(all P>0.05). However, significant differences existed in daily outdoor activity time, daily electronic device usage duration, maternal myopia degree, paternal myopia degree, maternal age of myopia onset, and paternal age of myopia onset(all P<0.05). Logistic regression analysis identified the following risk factors for myopia in preschool children: daily outdoor activity under 2 h, daily electronic device use exceeding 60 min, maternal myopia degree, maternal early-onset myopia, paternal high myopia, and paternal early-onset myopia. Analysis of interaction effects children gender and myopia-related factors on SE revealed significant interactions of children gender with paternal myopia degree, maternal and paternal age of myopia onset(P<0.05). Simple effects analysis further demonstrated that girls exhibited higher degree of myopia than boys in families with paternal early-onset myopia, maternal early-onset myopia, or paternal high myopia(P<0.05).CONCLUSION:Insufficient daily outdoor activity time(under 1 h), daily electronic device use exceeding 60 min, and parental myopia are significant risk factors for myopia development in preschool children. Among these children, girls' refractive status was particularly associated with parental refractive status.

Radiation-induced injury is a key factor in determining the prognosis of patients undergoing radiotherapy, highlighting the significant clinical importance of developing drugs for radiation prevention and treatment. Especially in oncology, radiation-induced injury remains a pivotal determinant of therapeutic outcomes, because of its direct correlation with normal tissue damage during radiotherapy. Efforts to mitigate or treat such injury are thus paramount in enhancing the overall safety and efficacy of cancer treatment. Novel nanomedicines with prolonged systemic circulation, versatile drug-loading capacities, enhanced tissue retention, and stimuli responsiveness exhibit unique advantages in the treatment and prevention of radiation-induced diseases, as they can be designed based on the specific microenvironment of radiation-damaged tissues, which offers innovative solutions to address the limitations of conventional radioprotectors such as short half-life, poor tissue targeting, and systemic side effects. This review thus aims to provide an overview of recent advance in the design and application of nanomaterials for radiation prevention and treatment. Generally, ionizing radiation damages cells either by inducing DNA double-strand breaks or through the generation of reactive oxygen species (ROS). The resulting oxidative stress would disrupt the structural integrity of cell membranes, proteins, and nucleic acids, leading to apoptosis, chronic inflammation, and systemic effects across multiple systems, including hematopoietic system, gastrointestinal tract, skin, lungs, brain, and heart. Radiation protection strategies focus on scavenging ROS, stimulating cellular repair and regeneration, inducing tissue hypoxia, and inhibiting apoptotic pathways. Recent advances in nanomedicine have introduced novel approaches for targeted and efficient radiation protection and treatment. For radiation-induced hematopoietic injury, nanoparticles can been designed to promote red and white blood cell regeneration while reducing oxidative stress. To address radiation-induced gastrointestinal injuries, nanomaterials enable localized antioxidant delivery and extended intestinal retention, effectively relieving radiation enteritis by scavenging ROS and modulating gut microbiota. For radiation-induced skin injuries, self-assembling peptide hydrogels that mimic the extracellular matrix can serve as effective scaffolds for wound healing. These hydrogels exhibit excellent antioxidant properties, stimulating angiogenesis, and accelerating the recovery of radiation dermatitis. In cases of radiation-induced brain damage, nanoparticles were designed to cross the blood-brain barrier to rescue neuronal damage and protect cognitive function. This review provides an in-depth insight into the mechanisms underlying radiation-induced injuries and highlights how nanomaterial were construtced according to the specific injury. Therefore, nanotechnology endowers durgs with transformative potential for preventing and treating radiation-induced injuries. Despite significant progress in nanomedicine, there are still challenges in long-term biocompatibility, precise targeting of damaged tissues, and scalable manufacturing. In addition, an in-depth understanding of the interactions between nanomaterials and biological systems remains to be covered. Future efforts should focus on optimizing design strategies, enhancing clinical translatability, and ensuring long-term safety, ultimately improving patient outcomes. Besides, expanding research into other radiation-induced diseases, such as radiation-induced ophthalmic disorders and hepatic injuries, may diversify therapeutic options.

Objective: To investigate the correlation between sleep fragmentation and body composition/blood pressure in female students of middle school, so as to provide theoretical guidance for preventing health risks associated with sleep fragmentation. Methods: From September 2022 to December 2023, 505 female students aged 12-15 years in Nanyang City were selected through stratified cluster random sampling and conducted Pittsburgh Sleep Quality Index(PSQI) survey. Participants were divided into Q 1- Q 4 groups based on sleep fragmentation index (SFI) quartiles. Body composition and blood pressure measurements were measured by adopting body composition analyzer and traditional mercury sphygmomanometer, and data were analyzed using χ 2 tests and linear regression. Results: Significant intergroup differences for Q 1- Q 4 were observed with increasing SFI levels for body mass index(BMI), fat percentage, muscle mass, bone mass, trunk fat percentage, systolic blood pressure, diastolic blood pressure, and PSQI total scores ( F =15.25,7.33,8.38,5.97,11.24,16.85,6.87,15.73, all P <0.05). SFI showed positive correlations with BMI, fat percentage, trunk fat percentage, and blood pressure( β =0.37,0.45,0.34,0.42,0.38), but negative correlations with muscle mass and bone mass( β =-0.35,-0.48) (all P <0.05). The χ 2 trend test revealed a significant increase in hypertension detection rates with elevated SFI ( χ 2=42.75, P <0.05). The χ 2 testing demonstrated statistically significant differences in hypertension incidence among different quartiles groups ( χ 2=14.16, P <0.05). After adjusting the significance level, hypertension incidence differences remained significant between Q 1and Q 4 ( χ 2=10.77), Q 2 and Q 4 groups ( χ 2=6.28) (both P <0.008 3). Conclusions Sleep fragmentation correlates significantly with body composition and blood pressure indicators in female students of middle school. Implementing sleep fragmentation interventions is essential for safeguarding female students health in middle school.

ObjectiveJunctophilin-2 (JPH2) is an essential structural protein that maintains junctional membrane complexes (JMCs) in cardiomyocytes by tethering the plasma membrane to the sarcoplasmic reticulum, thereby facilitating excitation-contraction (E-C) coupling. Mutations in JPH2 have been associated with hypertrophic cardiomyopathy (HCM), but the molecular mechanisms governing its membrane-binding properties and the functional relevance of its membrane occupation and recognition nexus (MORN) repeat motifs remain incompletely understood. This study aimed to elucidate the structural basis of JPH2 membrane association and its implications for HCM pathogenesis. MethodsA recombinant N-terminal fragment of mouse JPH2 (residues1-440), encompassing the MORN repeats and an adjacent helical region, was purified under near-physiological buffer conditions.X-ray crystallography was employed to determine the structure of the JPH2 MORN-Helix domain. Sequence conservation analysis across species and junctophilin isoforms was performed to assess the evolutionary conservation of key structural features. Functional membrane-binding assays were conducted using liposome co-sedimentation and cell-based localization studies in COS7 and HeLa cells. In addition, site-directed mutagenesis targeting positively charged residues and known HCM-associated mutations, including R347C, was used to evaluate their effects on membrane interaction and subcellular localization. ResultsThe crystal structure of the mouse JPH2 MORN-Helix domain was resolved at 2.6 Å, revealing a compact, elongated architecture consisting of multiple tandem MORN motifs arranged in a curved configuration, forming a continuous hydrophobic core stabilized by alternating aromatic residues. A C-terminal α-helix further reinforced structural integrity. Conservation analysis identified the inner groove of the MORN array as a highly conserved surface, suggesting its role as a protein-binding interface. A flexible linker segment enriched in positively charged residues, located adjacent to the MORN motifs, was found to mediate direct electrostatic interactions with negatively charged phospholipid membranes. Functional assays demonstrated that mutation of these basic residues impaired membrane association, while the HCM-linked R347C mutation completely abolished membrane localization in cellular assays, despite preserving the overall MORN-Helix fold in structural modeling. ConclusionThis study provides structural insight into the membrane-binding mechanism of the cardiomyocyte-specific protein JPH2, highlighting the dual roles of its MORN-Helix domain in membrane anchoring and protein interactions. The findings clarify the structural basis for membrane targeting via a positively charged linker and demonstrate that disruption of this interaction—such as that caused by the R347C mutation—likely contributes to HCM pathogenesis. These results not only enhance current understanding of JPH2 function in cardiac E-C coupling but also offer a structural framework for future investigations into the assembly and regulation of JMCs in both physiological and disease contexts.

ObjectiveTo clarify the repair effect of Mume Fructus on the intestinal mucosal epithelial barrier in the mouse model of inflammatory bowel disease （IBD） and explore the repair mechanism. MethodsThirty-six male C57BL/6 mice were randomly assigned into six groups： normal， model， low-， medium-， and high-dose （200， 400， and 800 mg·kg^-1） Mume Fructus， and sulfasalazine （300 mg·kg^-1）. Except the normal group， the rest groups had free access to 2% dextran sulfate sodium （DSS） solution for seven days to establish the IBD model， followed by a seven-day drug intervention. The body weight change and disease activity index （DAI） were recorded. After the last administration， spleen and colon tissue samples were collected to analyze the differences in colon length and spleen index. Hematoxylin-eosin staining was used to observe the morphology of the colon tissue. The level of diamine oxidase （DAO） in the serum was measured by the DAO assay kit. Immunohistochemistry was employed to determine the expression of tight junction proteins such as Claudin-1， Occludin， and zonula occludens-1 （ZO-1） in the colon tissue. Real-time PCR was performed to measure the mRNA levels of tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β） in the colon tissue. Finally， Western blot was employed to determine the protein levels of mitogen-activated protein kinase kinase （MEK）， extracellular signal-regulated kinase （ERK）， phosphorylated （p）-MEK， and phosphorylated ERK in the colon tissue. ResultsCompared with the normal group， the model group exhibited decreases in body weight and colon length （P<0.01）， increases in DAI， spleen index， and serum DAO level （P<0.01）， damaged colonic epithelium and goblet cells， and obvious infiltration of inflammatory cells. In addition， the model group exhibited higher positive expression of Claudin-1， Occludin， and ZO-1 （P<0.01）， higher mRNA levels of TNF-α and IL-1β （P<0.01）， and higher protein levels of p-MEK and p-ERK （P<0.05， P<0.01） than the normal group. However， sulfasalazine and three doses of Mume Fructus markedly decreased the body weight and DAI （P<0.05）， recovered the colon length and spleen index， alleviated colon tissue damage， lowered the level of DAO in the serum （P<0.01）， and down-regulated the mRNA levels of TNF-α and IL-1β （P<0.01） and the protein levels of p-MEK and p-ERK （P<0.05）. Sulfasalazine and low- and medium-dose Mume Fructus increased the positive expression of Occludin， Claudin-1， and ZO-1 （P<0.05， P<0.01）. Furthermore， high-dose Mume Fructus elevated the protein expression of Occludin （P<0.05）. ConclusionMume Fructus can restore the expression of intestinal epithelial tight junction proteins by inhibiting the phosphorylation of proteins in the MEK/ERK signaling pathway and down-regulating the levels of TNF-α and IL-1β， thus repairing the intestinal mucosal barrier in the mouse model of IBD.

Objective: To investigate the effect and mechanism of resveratrol-derived carbonized polymer dots (RSV-CPDs) on macrophage polarization and osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) under inflammatory conditions, and to provide an experimental basis for the treatment of periodontitis with RSV-CPDs. Methods: RSV-CPDs were prepared by high-temperature pyrolysis of resveratrol (RSV) in the presence of ammonia as a catalyst, and RSV-CPDs were characterized by transmission electron microscope (TEM), Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). CCK8 was used to detect the cytotoxicity of RSV-CPDs. The effects of RSV-CPDs on the apoptosis and cell polarization of macrophages stimulated by Porphyromonas gingivalis-lipopolysaccharide (P.g-LPS) were detected by flow cytometry: ① For the apoptosis detection experiment, the macrophages (RAW264.7) were divided into the control group (no treatment), P.g-LPS group [treated with P.g-LPS (2 μg/mL) for 24 h], RSV group [treated with P.g-LPS (2 μg/mL) + RSV (10 μg/mL) for 24 h], and RSV-CPDs group [treated with P.g-LPS (2 μg/mL) + RSV-CPDs (50 μg/mL) for 24 h]. ② For the cell polarization experiment, the macrophages (RAW264.7) were divided into four groups. They were the control group (no treatment), P.g-LPS + IFN-γ group [P.g-LPS (200 ng/mL) + IFN-γ (20 ng/mL) treated cells for 24 h], RSV group [P.g-LPS (200 ng/mL) + IFN-γ (20 ng/mL) + RSV (10 μg / mL) treated cells for 24 h], RSV-CPDs group [P.g-LPS (200 ng / mL) + IFN-γ (20 ng / mL) + RSV-CPD (50 μg / mL) treated cells for 24 h]. The supernatant of macrophages in the above four groups of cell polarization experiments was collected and mixed with osteogenic induction medium at a 1:1 ratio to culture hPDLSCs. The hPDLSCs were divided into the control group, P.g-LPS + IFN-γ group, RSV group, and RSV-CPDs group. The osteogenic trend of hPDLSCs was detected by alkaline phosphatase (ALP) staining and alizarin red staining (ARS). Real-time quantitative PCR (RT-qPCR) was used to detect the expression of osteogenesis-related genes. Western blot was used to detect the expression of osteogenesis-related proteins in hPDLSCs. Finally, transcriptome tests were used to explore the mechanism of the effect of RSV-CPDs on the phenotype of macrophages (THP-1) stimulated by inflammation. Results: TEM results showed that RSV-CPDs exhibited a uniform spherical structure. FTIR results showed the O-C=O peak of RSV-CPDs. XRD results confirmed that the newly synthesized RSV-CPDs exhibited an amorphous structure. XPS results showed that RSV-CPDs formed a hydrophilic carboxyl group. CCK-8 results showed that RSV had specific toxicity to RAW264.7 when the concentration exceeded 10 μg/mL (P = 0.011), while RSV-CPDs still had good biosafety to cells when the concentration reached 50 μg/mL (P > 0.05). Therefore, the concentration of RSV was 10 μg/mL and RSV-CPDs was 50 μg/mL. The results of flow cytometry showed that RSV-CPDs inhibited the apoptosis of macrophages under inflammatory stimulation (P = 0.008), and the inhibitory effect was better than that of its precursor RSV (P = 0.009). Compared with the P.g-LPS + IFN-γ group, CD86+ cells in the RSV group and RSV-CPDs group decreased by varying degrees (P < 0.001, P = 0.004), while CD206+ cells increased by varying degrees (P = 0.006, P = 0.008), and the proportion of CD206+ cells in the RSV-CPDs group was higher than that in the RSV group (P = 0.010). Compared with the P.g-LPS + IFN-γ group, the supernatant of macrophages treated with RSV-CPDs significantly increased the ALP expression (P = 0.005) and ARS level (P = 0.006) of hPDLSCs. The mRNA expression of osteogenic-related genes RUNX-2, OCN, and COL-1 significantly increased (P < 0.05), and the level of RUNX-2 protein also significantly increased (P = 0.001). Transcriptome results showed that compared with the P.g-LPS + IFN-γ group, the nuclear factor kappa-B (NF-κB) signaling pathway and tumor necrosis factor (TNF) signaling pathway in the RSV-CPDs group showed downward trends. Conclusion RSV-CPDs can inhibit the apoptosis of macrophages in the inflammatory state, promote M2 polarization, and bolster the osteogenic differentiation of hPDLSCs. The mechanism involved may be related to the inhibition of NF-κB and TNF signaling pathways.

ObjectiveTo investigate the trend and influencing factors of newly reported human immunodeficiency virus (HIV) positivity rate among men who had sex with men (MSM) in Shanghai from 2021 to 2024, and to provide evidence for formulating scientific prevention and control measures of AIDS. MethodsMultiple rounds of cross-sectional questionnaire surveys were conducted among MSM by Shanghai Qing’ai Health Promotion Center. Pearson and Cochran-Armitage trend χ² tests were used to analyze the differences and changes in population characteristics and newly reported HIV positivity rates. A logistic regression model was applied for multivariate analyses of factors associated with newly reported HIV positivity. ResultsA total of 1 653 MSM who had not been previously diagnosed with HIV infection were surveyed. The newly reported HIV positivity rates in 2021, 2023, and 2024 were 7.87%, 3.91%, and 3.06%, respectively, showing a decreasing trend (χ²_trend=13.460, P_trend<0.001). Multivariate analyses revealed that MSM aged 18‒<25 years, residing locally for <1 year, identifying as bisexual, lacking HIV knowledge, and having ≥10 same-sex partners in the past 6 months exhibited higher newly reported HIV positivity rates. Conversely, MSM knowledgeable about HIV prevention, residing locally for 1‒5 years, and engaging in oral sex with male partners in the past 6 months demonstrated lower HIV positivity rates. Annual analyses revealed that MSM with HIV knowledge had lower newly reported HIV positivity rates in 2023 and 2024 (aOR=0.300, 95%CI: 0.811‒0.111; aOR=0.202, 95%CI: 0.085‒0.483). ConclusionThe newly reported HIV positivity rate among MSM in Shanghai from 2021 to 2024 showed a decline. Future interventions should focus on young and mobile MSM, strengthen HIV knowledge education through platforms such as the internet, promote safe sexual behaviors and regular testing, and further expand the coverage of pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) to control HIV transmission within this population.