BACKGROUND:The mesenchymal stem cell secretome contains bioactive substances,cytokines,and growth factors.Three-dimensional cell culture can regulate the secretion of these components,potentially enhancing the ability to promote injury repair.OBJECTIVE:To investigate the repair effect of three-dimensional cultured human umbilical cord mesenchymal stem cell secretome on skin injuries in mice.METHODS:Human umbilical cord mesenchymal stem cells were cultured in conventional two-dimensional culture dishes and 96-well U-bottom cell culture plates,from which their secretory components were subsequently collected.The expression of skin damage repair related secretory factors in umbilical cord mesenchymal stem cells was analyzed using RT-qPCR.The protein expression level of skin damage repair related factors in umbilical cord mesenchymal stem cell secretome was detected using enzyme-linked immunosorbent assay.The potential of human umbilical cord mesenchymal stem cell secretome to repair vascular injuries was evaluated using an immortalized human umbilical vein endothelial cell migration model.A mouse skin injury model was established,and the human umbilical cord mesenchymal stem cell secretome was injected subcutaneously.Repair effects on skin injury were assessed through wound healing rates and histopathological analysis.RESULTS AND CONCLUSION:(1)After three days of cultivation,human umbilical cord mesenchymal stem cells cultured in two dimensions exhibited a fibroblast-like,swirling growth pattern,whereas three-dimensional culture led to the formation of uniform microspheres.(2)Compared with two-dimensional culture,three-dimensional culture significantly increased the mRNA expression of transforming growth factor β and basic fibroblast growth factor in human umbilical cord mesenchymal stem cells.(3)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly enhanced the protein expression of vascular endothelial growth factor,interleukin-10,and granulocyte-macrophage colony-stimulating factor in the human umbilical cord mesenchymal stem cell secretome.(4)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly promoted the migration of immortalized human umbilical cord mesenchymal stem cells.(5)Compared with the untreated control group and the two-dimensional cultured human umbilical cord mesenchymal stem cell secretome,the three-dimensional cultured human umbilical cord mesenchymal stem cell secretome can significantly accelerate the skin wound healing rate and wound skin structure remodeling in mice.These results indicate that three-dimensional culture can enhance the expression of paracrine factors of human umbilical cord mesenchymal stem cells,and their secretome can significantly promote the repair of mouse skin damage.

ObjectiveIn the context of the digital transformation of education, this study aims to construct a triadic interactive teaching model for surgical animal surgery in clinical medicine using modern information technology. It explores the effectiveness of different teaching methods in improving students' practical skills, aseptic awareness, and teamwork abilities, providing a reference for the reform of clinical practice education. MethodsA quasi-experimental research design was adopted. A total of 80 students from the eight-year clinical medicine program at Nanjing University were selected, including the Class of 2020 (control group, n=40) and the Class of 2021 (experimental group, n=40). The control group received traditional teaching methods, while the experimental group implemented the "Teacher-Student-AI" triadic interactive teaching model. This model utilized a smart teaching platform for personalized pre-class preparation , as well as data-driven post-class review and feedback throughout the entire teaching process. The "assessment indicators and scoring criteria for the surgical animal surgery course" were used to evaluate teaching effectiveness, with independent samples t-tests used for statistical analysis. ResultsPre-course assessments revealed no statistically significant differences in baseline theoretical knowledge or practical skills between the two groups (P>0.05). Upon completion of the course, the experimental group achieved higher scores than the control group across three key dimensions: practical skills (47.98±1.34 vs 46.92±2.51, P=0.022), aseptic awareness (17.84±1.16 vs 16.94±2.29, P=0.029), and teamwork (16.82±1.44 vs 15.95±1.22, P=0.004). However, no statistically significant difference was observed in the scores for humane care awareness between the two groups (8.24±0.70 vs 8.16±0.53, P=0.589). ConclusionThe AI-based triadic interactive teaching model can, to some extent, address the limitations of traditional surgical animal surgery education. It plays a positive role in enhancing medical students' surgical skills, aseptic awareness, and collaborative abilities. This model facilitates the transition from traditional to personalized teaching and offers a practical framework for the digital reform of clinical practice education.

ObjectiveTo investigate the molecular mechanism by which Yifei Xuanfei Jiangzhuo prescription regulates the nuclear factor-κB （NF-κB）/NOD-like receptor protein 3 （NLRP3） signaling pathway to improve neuronal function in vascular dementia （VaD） rats. MethodsA VaD model was established by intermittently clamping the bilateral common carotid arteries （CCA） combined with bilateral vascular occlusion （2-VO）. Eighty-four SD rats were randomly divided into a blank group， sham group， model group， piracetam group （0.2 g·kg^-1）， and low-， medium-， and high-dose Yifei Xuanfei Jiangzhuo prescription groups （6.09， 12.18， and 24.36 g·kg^-1）. Drug administration began on day 7 after surgery， once daily for 28 consecutive days. Behavioral experiments were used to evaluate learning and spatial memory. Hematoxylin-eosin （HE） staining was applied to observe pathological morphological changes in the CA1 region of the hippocampus. Transmission electron microscopy was used to examine the ultrastructure of hippocampal neurons. Terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL） was used to detect neuronal apoptosis in the CA1 region. Immunohistochemistry was performed to determine the positive expression rate of neuronal nuclear antigen （NeuN）. Immunofluorescence single staining was used to assess nuclear expression of NF-κB p65 in brain tissue. Western blot was used to detect the protein expression levels of inhibitor of κB kinase （IKK）， NF-κB p65， NLRP3， Caspase-1， apoptosis-associated speck-like protein （ASC）， and interleukin-1β （IL-1β）. ResultsCompared with the blank group， the model group showed a significant reduction in platform-crossing frequency （P0.01）， aggravated hippocampal injury， a significant increase in neuronal apoptosis （P0.05）， decreased NeuN positivity in the CA1 region （P0.05）， increased nuclear expression of NF-κB p65 （P0.05）， and significantly elevated expression of p-IKK， p-NF-κB p65， NLRP3， cleaved Caspase-1， ASC， and cleaved IL-1β （P0.05）. Compared with the model group， all drug-treated groups improved learning and spatial memory in VaD rats， alleviated hippocampal pathological injury and neuronal apoptosis， and protected neuronal ultrastructure. Yifei Xuanfei Jiangzhuo prescription at doses of 12.18 and 24.36 g·kg^-1 reduced hippocampal expression levels of p-IKK， p-NF-κB p65， NLRP3， Caspase-1， ASC， and cleaved IL-1β in VaD rats （P0.05）， showing dose-dependent inhibition of the NF-κB/NLRP3 signaling pathway. ConclusionYifei Xuanfei Jiangzhuo prescription may exert neuroprotective effects by regulating the NF-κB/NLRP3 signaling pathway， thereby reducing neuroinflammation and inhibiting hippocampal neuronal apoptosis.

ObjectiveTo investigate the molecular mechanism by which Yifei Xuanfei Jiangzhuo prescription regulates the nuclear factor-κB （NF-κB）/NOD-like receptor protein 3 （NLRP3） signaling pathway to improve neuronal function in vascular dementia （VaD） rats. MethodsA VaD model was established by intermittently clamping the bilateral common carotid arteries （CCA） combined with bilateral vascular occlusion （2-VO）. Eighty-four SD rats were randomly divided into a blank group， sham group， model group， piracetam group （0.2 g·kg^-1）， and low-， medium-， and high-dose Yifei Xuanfei Jiangzhuo prescription groups （6.09， 12.18， and 24.36 g·kg^-1）. Drug administration began on day 7 after surgery， once daily for 28 consecutive days. Behavioral experiments were used to evaluate learning and spatial memory. Hematoxylin-eosin （HE） staining was applied to observe pathological morphological changes in the CA1 region of the hippocampus. Transmission electron microscopy was used to examine the ultrastructure of hippocampal neurons. Terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL） was used to detect neuronal apoptosis in the CA1 region. Immunohistochemistry was performed to determine the positive expression rate of neuronal nuclear antigen （NeuN）. Immunofluorescence single staining was used to assess nuclear expression of NF-κB p65 in brain tissue. Western blot was used to detect the protein expression levels of inhibitor of κB kinase （IKK）， NF-κB p65， NLRP3， Caspase-1， apoptosis-associated speck-like protein （ASC）， and interleukin-1β （IL-1β）. ResultsCompared with the blank group， the model group showed a significant reduction in platform-crossing frequency （P0.01）， aggravated hippocampal injury， a significant increase in neuronal apoptosis （P0.05）， decreased NeuN positivity in the CA1 region （P0.05）， increased nuclear expression of NF-κB p65 （P0.05）， and significantly elevated expression of p-IKK， p-NF-κB p65， NLRP3， cleaved Caspase-1， ASC， and cleaved IL-1β （P0.05）. Compared with the model group， all drug-treated groups improved learning and spatial memory in VaD rats， alleviated hippocampal pathological injury and neuronal apoptosis， and protected neuronal ultrastructure. Yifei Xuanfei Jiangzhuo prescription at doses of 12.18 and 24.36 g·kg^-1 reduced hippocampal expression levels of p-IKK， p-NF-κB p65， NLRP3， Caspase-1， ASC， and cleaved IL-1β in VaD rats （P0.05）， showing dose-dependent inhibition of the NF-κB/NLRP3 signaling pathway. ConclusionYifei Xuanfei Jiangzhuo prescription may exert neuroprotective effects by regulating the NF-κB/NLRP3 signaling pathway， thereby reducing neuroinflammation and inhibiting hippocampal neuronal apoptosis.

BACKGROUND:The mesenchymal stem cell secretome contains bioactive substances,cytokines,and growth factors.Three-dimensional cell culture can regulate the secretion of these components,potentially enhancing the ability to promote injury repair.OBJECTIVE:To investigate the repair effect of three-dimensional cultured human umbilical cord mesenchymal stem cell secretome on skin injuries in mice.METHODS:Human umbilical cord mesenchymal stem cells were cultured in conventional two-dimensional culture dishes and 96-well U-bottom cell culture plates,from which their secretory components were subsequently collected.The expression of skin damage repair related secretory factors in umbilical cord mesenchymal stem cells was analyzed using RT-qPCR.The protein expression level of skin damage repair related factors in umbilical cord mesenchymal stem cell secretome was detected using enzyme-linked immunosorbent assay.The potential of human umbilical cord mesenchymal stem cell secretome to repair vascular injuries was evaluated using an immortalized human umbilical vein endothelial cell migration model.A mouse skin injury model was established,and the human umbilical cord mesenchymal stem cell secretome was injected subcutaneously.Repair effects on skin injury were assessed through wound healing rates and histopathological analysis.RESULTS AND CONCLUSION:(1)After three days of cultivation,human umbilical cord mesenchymal stem cells cultured in two dimensions exhibited a fibroblast-like,swirling growth pattern,whereas three-dimensional culture led to the formation of uniform microspheres.(2)Compared with two-dimensional culture,three-dimensional culture significantly increased the mRNA expression of transforming growth factor β and basic fibroblast growth factor in human umbilical cord mesenchymal stem cells.(3)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly enhanced the protein expression of vascular endothelial growth factor,interleukin-10,and granulocyte-macrophage colony-stimulating factor in the human umbilical cord mesenchymal stem cell secretome.(4)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly promoted the migration of immortalized human umbilical cord mesenchymal stem cells.(5)Compared with the untreated control group and the two-dimensional cultured human umbilical cord mesenchymal stem cell secretome,the three-dimensional cultured human umbilical cord mesenchymal stem cell secretome can significantly accelerate the skin wound healing rate and wound skin structure remodeling in mice.These results indicate that three-dimensional culture can enhance the expression of paracrine factors of human umbilical cord mesenchymal stem cells,and their secretome can significantly promote the repair of mouse skin damage.

ObjectiveTo investigate and analyze the source of infection in an outbreak of gastroenteritis in a kindergarten of Xinjiang Production and Construction Corps, and to provide a reference for formulating targeted epidemic prevention and control strategies. MethodsCases were identified through face-to-face interviews, telephone follow-ups, and by reviewing kindergarten attendance records, medical institution outpatient logs, and admission/discharge registers. Fecal samples, vomitus, anal swabs, food samples, leftover ingredients, and environmental samples from cafeteria and classrooms were collected. These samples were simultaneously screened for norovirus using real-time fluorescent reverse transcription polymerase chain reaction (RT-PCR) and for enteric pathogens such as Salmonella, diarrheagenic Escherichia coli, and Staphylococcus aureus using real-time fluorescent quantitative PCR. ResultsFrom May 7 to 10, 2024, a total of114 children (64 boys and 50 girls) were enrolled in the kindergarten, including 26 children in the younger class. A total of 15 norovirus cases were identified, all from the younger class, resulting in an overall attack rate of 13.16% (15/114). The main clinical symptoms included vomiting (93.33%), diarrhea (80.00%), fever (20.00%), and abdominal pain (6.67%). The male-to-female case ratio was 1.5∶1, with most cases occurring among the 4-year-old age group, accounting for 73.33% (11/15) of all cases. The outbreak lasted 63.67 h. A total of 42 samples were collected, including 13 clinical specimens (5 vomit samples, 7 fecal samples, and 1 anal swab), 4 food samples and leftover ingredients from the 48-hour food retention period, 5 environmental samples from the cafeteria, and 20 environmental samples from the younger class classroom (3 storage boxes, 2 bedding sets, 4 LEGO walls, 3 watercolor pens, 4 toy cabinets, 3 cup-swab samples, and 1 tap water sample from the direct drinking water dispenser). RT-PCR results showed a positivity rate of 53.85% (7/13) among patient specimens, with 5 cases testing positive for norovirus GⅡ genotype. The positivity rates for vomitus and fecal samples were 40.00% (2/5) and 71.43% (5/7), respectively. Norovirus GⅡ genotype was detected in 5 of 20 environmental samples from the younger class classroom, yielding a positivity rate of 25.00%(5/20). However, all food, drinking water, and cafeteria environmental samples were negative. ConclusionThis incident is an outbreak and cluster of infections caused by norovirus GⅡ in a kindergarten and the critical factor is that the index case entered the kindergarten while ill. It is necessary to strengthen health education, enhance the disease prevention awareness of teachers, students and parents, develop good hygiene habits, and achieve early detection, reporting, and timely control of such incidents.

A new method was developed for simultaneous and efficient determination of linear perfluorooctanoic acid(n-PFOA)and linear perfluorooctane sulfonate(n-PFOS),and their typical branched isomers in seawater by online solid phase extraction-liquid chromatography-tandem mass spectrometry(Online SPE-LC-MS/MS).Only centrifugation of the seawater sample was required to remove the particulate matter,and then the seawater sample was directly injected and analyzed by online SPE-LC-MS/MS.An Eclipse Plus-C18 guard column was selected as SPE column for online enrichment of linear and branched isomers,and a F5 PFP column(150 mm×2.1 mm,2.7 μm)was used as the analytical column.Under the optimized experimental conditions,the separation and detection of all PFOA and PFOS linear and branched isomers could be completed within 20 min.The spiked recoveries of various target compounds ranged from 82.9%to 107.7%with detection limits and limits of quantification of 0.10-1.05 ng/L and 0.30-2.11 ng/L,respectively.The method was characterized by good precision(RSD≤9.10%)and linearity(R2≥0.990).Subsequently,linear and branched isomers of PFOA and PFOS in surface and bottom seawater samples collected from the Laizhou Bay of China were determined.The results showed that the detection rate of all the four branched PFOA isomers were 100%,with the highest average concentration of 25.85 ng/L found for 6m-PFOA,which accounted for 11.79%of the∑PFOA.For the five branched isomers of PFOS,the highest detection rate of 90.84%was found for 5m-PFOS.The highest average concentration of 0.64 ng/L was observed for 3m-PFOS,accounting for 19.88%of ∑PFOS.The proposed method provided an effective detection tool for qualitative and quantitative detection of PFOA and PFOS isomers in the marine aquatic environment.

Infant formula milk powder(infant formula)contains a variety of fatty acids that require hydrolysis and derivation,and the calibration methods are complex and variable,affecting the accuracy of quantification.Using the gas chromatography with flame ionization detector(GC-FID)under internal standard and external standard calibration methods,the effects of using fatty acid methyl esters(FAMEs)and triacylglycerol(TAGs)as calibration solutions on determination of 19 kinds of fatty acids content in infant formula were compared in this work.Additionally,the differences in determination between the acetyl chloride methanol method and the hydrolysis extraction method using FAMEs as the calibration solution under internal standard method were also compared.The quantitative results of TAGs external standard quantitative method were significantly higher than those of FAMEs external standard quantitative method and FAMEs calibrator derived by methylation,and the deviation of quantitative results were 7%-20%and 2%-10%,respectively.The quantitative results of FAMEs calibrator added FAME internal standard were significantly higher than those of FAMEs calibrator added FAME internal standard derived from TAG methylation and FAMEs calibrator added TAG internal standard with methyl esterification,and the deviation of quantitative results were about 15%and 2%-5%,respectively.The results indicated that both the two methods of internal standard calibration using FAMEs as the calibration solution and external standard calibration using TAGs as the calibration solution could effectively eliminate the bias in the determination,with simple operation and accurate comparation of the results.However,the results were significantly lower under the external standard calibration using FAMEs as calibration solution.

Aim To explore the effect of hydroxysafflor yellow A(HSYA)on lipocalin 2(LCN2)-induced fer-roptosis in HT22 cells and the related mechanism.Methods Thirty male Sprague-Dawley(SD)rats were used to establish the middle cerebral artery occlu-sion/reperfusion(MCAO/R)model by the suture method.The rats were randomly divided into the Sham group,the MCAO/R group,and the MCAO/R+HSYA group.The infarct area was measured by TTC staining,and the degree of neurological deficit was evaluated by the Z-Longa scoring method.The expressions of LCN2 and 24P3R in brain tissues were detected by Western blot.LCN2 protein was added to HT-22 cells,and the cells were divided into the normal group,the LCN2 group,and the LCN2+HSYA group.The optimal con-centration of LCN2-induced neuronal ferroptosis was screened by LDH assay and Western blot,and the ex-pression levels of ferritin,FPN1,GPX4,SLC7A11,COX2,and 24P3R were detected.LCN2 was knocked down by siRNA transfection,and the expressions of GPX4 and ferritin were detected.The contents of glu-tathione(GSH),malondialdehyde(MDA),GPX4,and Fe2+were determined by colorimetry,and the expres-sion of GPX4 was detected by immunofluorescence.The binding force between HSYA and LCN2 was ana-lyzed by molecular docking technology.Results Ani-mal experiments showed that HSYA could reduce the cerebral infarction area and decrease the neurological function score of MCAO/R rats.Compared with the sham group,the levels of LCN2 and 24P3R increased in the MCAO/R group,while HSYA inhibited their ex-pressions.Cell experiments showed that the optimal concentration of LCN2 to induce ferroptosis in HT22 cells was 2 μmol·L-1.After knocking down LCN2 by siRNA transfection,compared with the LCN2 group,the expression levels of GPX4 and ferritin in the siLCN2 group increased significantly.Compared with the nor-mal group,the expressions of SLC7A11,GPX4,FPN1,ferritin,and GSH in the LCN2 group decreased signifi-cantly,while the concentration of Fe2+,and the expres-sions of MDA,COX2,and 24P3R increased.HSYA could increase the expressions of SLC7A11,GPX4,FPN1,ferritin,and GSH,reduce the contents of Fe2+and MDA,and inhibit the expressions of COX2 and 24P3R.Molecular docking showed that the binding en-ergy between HSYA and LCN2 was-8.0 kJ·mol-1.Conclusion HSYA can inhibit LCN2-induced ferrop-tosis in HT22 cells through the SLC7A11/GPX4 signa-ling pathway.

Objective:To explore the potential profiles of health literacy in patients with chronic atrophic gastritis (CAG) and analyze their influencing factors.Methods:A cross-sectional study was conducted to select CAG patients admitted to Nanjing Hospital of Traditional Chinese Medicine or attending outpatient clinics from January 2023 to June 2024 by convenience sampling method, and all patients participated in this study two months after treatment. The General Information Questionnaire, the General Self-Efficacy Scale, and the All-around Health Literacy Measurement Scale (AAHLS) were used to conduct the questionnaire survey. The three dimensions of AAHLS were used as exogenous indicators for potential profile analysis, to compare the differences in general information and self-efficacy of patients with different potential profiles, and to analyze the influencing factors of different potential profiles of health literacy in CAG patients by multi classification Logistic regression.Results:The recovery rate of valid questionnaires was 97.71%(256/262). Among the 256 patients, there were 164 males and 92 females, with 86 patients aged 18-44 years old, 110 patients aged 45-59 years old, and 60 patients aged ≥ 60 years old. The health literacy of CAG patients was categorized into 3 potential profiles, including the high health literacy-appraisal and application competence group (14.84%, 38/256), the medium health literacy-appraisal and application competence group (32.81%, 84/256), and the low health literacy-appraisal and application competence group (52.34%, 134/256). The results of multi classification Logistic regression analysis showed that when the low health literacy-appraisal and application competence group was used as a reference, aged 18-44 years old ( OR=8.954, 95% CI 2.049-39.127), poor self-efficacy ( OR=0.089, 95% CI 0.027-0.293), duration of disease <5 years ( OR=0.049, 95% CI 0.014-0.169), per capita monthly household income<3 000 yuan ( OR=0.072, 95% CI 0.018-0.299), and primary school education or below ( OR=0.016, 95% CI 0.003-0.088) were independent influences in the the high health literacy-appraisal and application competence group (all P<0.05); poorer self-efficacy ( OR=0.458, 95% CI 0.251-0.834) and per capita monthly household income<3 000 yuan ( OR=0.212, 95% CI 0.100-0.453) were independent influences in the medium health literacy-appraisal and application competence group (both P<0.05). Conclusions:The health literacy of CAG patients is obviously heterogeneous, and healthcare professionals in clinical work should adopt targeted assessment and intervention according to the different characteristics of each category in order to improve the health literacy of CAG patients.