Background Depressive symptoms have become a significant factor affecting the physical and mental health of the occupational population, and workers in petroleum refining enterprises face multiple stressors in their work environment. Objective To explore the impact of occupational noise exposure on depressive symptoms among workers in a petroleum refining enterprise. Methods This cross-sectional study was conducted in July 2024 using a questionnaire survey among workers of a petroleum refining enterprise in Hainan Province. Basic information of the subjects was collected. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to measure depressive symptoms, the Chinese version of the Pittsburgh Sleep Quality Index (PSQI) scale was used to assess sleep quality, and the Chinese version of the Effort-Reward Imbalance (ERI) scale was used to evaluate occupational stress. Chi-square test was employed to compare the differences in reporting depressive symptoms among populations with different characteristics. Binary logistic regression models were used to analyze the impact of occupational noise exposure and other factors on depressive symptoms. Results The overall positive rate of depressive symptoms in the study population was 42.7%. The results of the multifactor analysis indicated that compared with the control group, employees in both the low-exposure and high-exposure groups had elevated odds of depressive symptoms, with OR (95%CI) of 2.244 (1.131, 4.454) and 1.970 (1.009, 3.850), respectively. This association remained robust after adjusting for potential confounders, including gender, age, work tenure, and other occupational exposures. Additionally, female [OR (95%CI)=1.483 (1.039, 2.118)], exposure to benzene, toluene, or xylene [OR (95%CI)=1.621 (1.208, 2.174)], sleep disturbance [OR (95%CI)=3.772 (2.942, 4.838)], and occupational stress [OR (95%CI)=2.018 (1.575, 2.585)] were also significantly associated with higher odds of depressive symptoms. Conclusion The positive rate of depressive symptoms is relatively high among employees in this petrochemical enterprise, and occupational noise exposure may be a risk factor for depressive symptoms.

Objective To explore the adverse event signals of children using macrolide drugs （azithromycin, clarithromycin, and erythromycin）, and provide reference for rational medicine use in clinical practice. Methods Data from children under 12 years old were extracted from the US FAERS database spanning from the first quarter of 2004 to the second quarter of 2023. The adverse drug reaction （ADR） signal mining for three macrolide antibiotics was conducted using the Reporting Odds Ratio （ROR） and Bayesian Confidence Propagation Neural Network （BCPNN） methods. Special emphasis was placed on analyzing and contrasting the differences in adverse events among the three drugs. Results A total of 1 615 reports for children under 12 years old were retrieved from the FAERS database, including 1 024 reports of azithromycin, 460 reports of clarithromycin, and 131 reports of erythromycin. Among azithromycin and erythromycin, there were more reports from boys than girls, while for clarithromycin, there were more reports from girls than boys. Oral administration was the most common route of administration for all three drugs. Regarding the outcome of adverse events reported, azithromycin and clarithromycin were primarily associated with other serious adverse events, whereas erythromycin was mainly associated with hospitalization and other serious adverse events. The number of adverse events reported decreased with increasing age, with a higher number of reports in the 0-3 age group. Using the ROR and BCPNN methods for signal detection, 86 signals were identified for azithromycin, 91 for clarithromycin, and 34 for erythromycin. These signals involved 22 System Organ Classes （SOCs）, with azithromycin mainly concentrated in skin and subcutaneous tissue disorders （n=21）, clarithromycin in gastrointestinal disorders （n=15）, and erythromycin in gastrointestinal disorders （n=8）. Twenty-four signals of moderate to high risk were detected, with 13 for azithromycin, 9 for clarithromycin, and 2 for erythromycin. Conclusion The adverse events induced by the three drugs with different risks in different systems. When clinically treating Mycoplasma pneumoniae pneumonia in children, the risk profiles of drugs in different systems should be considered, and personalized dosing should be implemented.

ObjectiveTaking the cuproptosis/oxidative stress pathway as the entry point， this study investigated the effect and mechanism of Liangyi Paste on hepatic lipid deposition in naturally aged mice fed with a high-fat diet. MethodsAfter adaptive feeding， 80 ten-week-old male C57BL/6 mice were used. Thirty of them were randomly divided into three groups （10 mice per group）： The 12-month-old control group （12MCON）， the 15-month-old control group （15MCON）， and the 15-month-old group with a high-fat diet （15MHFD）. The 12MCON and 15MCON groups were continuously fed a standard diet， while the 15MHFD group started receiving a high-fat diet at 12 months of age. Tissue samples were collected at the corresponding time points for each group. The remaining 50 mice were randomly divided into five groups （10 mice per group）： the 20-month-old control group （20MCON）， the model group， and the low-， medium-， and high-dose Liangyi Paste groups （2.91 ， 5.82 ， 11.64 g·kg^-1·d^-1， respectively）. The 20MCON group was continuously fed a standard diet， while the other groups started receiving a high-fat diet at 15 months of age. At 18 months of age， the Liangyi Paste groups were administered the corresponding doses of Liangyi Paste by gavage， while the 20MCON and model groups were given an equal volume of saline by gavage. After 8 weeks of continuous gavage （when the mice reached 20 months of age）， tissue samples were collected. Hepatic TG levels were measured using assay kits； liver histology and lipid deposition were observed via hematoxylin-eosin （HE） and oil red O staining； reactive oxygen species （ROS） were detected by enzyme-linked immunosorbent assay （ELISA）； Cu²⁺， superoxide dismutase （SOD）， and malondialdehyde （MDA） levels were measured by colorimetry； mRNA and protein expression of genes related to cuproptosis and oxidative stress pathways were analyzed by Real-time polymerase chain reaction（Real-time PCR） and Wes automated protein expression system. ResultsCompared with 12MCON， the 15MCON group showed significantly increased hepatic TG， Cu²⁺， ROS， and MDA levels （P<0.01）， decreased SOD （P<0.01）， hepatocyte swelling， and disordered arrangement. The mRNA and protein levels of ferredoxin 1 （FDX1）， dihydrolipoamide S-acetyltransferase （DLAT）， heat shock protein 70 （HSP70）， dihydrolipoamide dehydrogenase （DLD）， pyruvate dehydrogenase E1 subunit-β （PDHB）， nuclear factor erythroid 2-related factor 2 （Nrf2）， and peroxisome proliferator-activated receptor γ （PPARγ） were significantly elevated （P<0.05， P<0.01）. Compared with 15MCON group， the 15MHFD and 20MCON groups exhibited further increases in TG， Cu²⁺， ROS， and MDA （P<0.01）， reduced SOD （P<0.01）， and aggravated hepatocyte swelling and disorder. There were increased lipid droplets with mild vacuolization in the 15MHFD group， and no significant lipid deposition was observed in the 20MCON group. FDX1， DLAT， HSP70， DLD， PDHB， Nrf2， and PPARγ mRNA and protein levels were significantly increased （P<0.05， P<0.01）. Compared with 20MCON group， the model group demonstrated markedly elevated TG， Cu²⁺， ROS， and MDA （P<0.01）， reduced SOD （P<0.01）， severe hepatic steatosis， and upregulated expression of FDX1， DLAT， HSP70， DLD， PDHB， Nrf2， and PPARγ mRNA and proteins （P<0.05， P<0.01）. All abnormalities were significantly reversed after Liangyi Paste treatment. ConclusionLiangyi paste can ameliorate hepatic lipid deposition in naturally aged mice with a high-fat diet by modulating the cuproptosis/oxidative stress pathway.

BACKGROUND:Cell-free therapy is a research hotspot in the field of medical cosmetic anti-aging.It is still unknown for paracellular secretion of human umbilical cord mesenchymal stem cell-derived small extracellular vesicles loaded with the antiaging drug α-ketoglutaric acid to delay skin aging.OBJECTIVE:To investigate the effect of the anti-aging agent α-ketoglutarate engineered human umbilical cord mesenchymal stem cell-derived small extracellular vesicles in a D-galactose-induced model of dermal fibroblast senescence.METHODS:(1)Biological characteristics of primary human umbilical cord mesenchymal stem cells were identified by osteogenic-lipogenic differentiation staining and flow cytometry.(2)The small extracellular vesicles derived from human umbilical cord mesenchymal stem cell were obtained by using differential-ultracentrifugation.α-Ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles were constructed by electroporation,and biologically characterized by transmission electron microscopy and nanoparticle tracking analyzer,while the encapsulation rate was assessed using high-performance liquid chromatography.(3)The effect of α-ketoglutarate on the proliferative capacity of dermal fibroblasts was assessed by CCK-8 and Edu cell proliferation assay kits.(4)The effect of α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles on delaying the senescence of dermal fibroblasts was evaluated by reactive oxygen species detection kit,western blot assay,and cellular immunofluorescence.RESULTS AND CONCLUSION:(1)The obtained human umbilical cord mesenchymal stem cell and human umbilical cord mesenchymal stem cell-small extracellular vesicles were biologically compatible.(2)There was no toxic effect on dermal fibroblasts when α-ketoglutarate was used in the concentration range of 0.5-8 mmol/L.(3)D-gal induced senescence in dermal fibroblasts,while α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles treatment reduced the level of oxidative stress,DNA damage,and collagen loss,which was further verified that α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles could effectively slow down the skin aging process.

Objective To describe the clinical characteristics and nutritional management status of hospitalized elderly patients with multimorbidity in a tertiary hospital's geriatric center in 2024, and to analyze the correlation between nutritional status and hospitalization outcomes, thereby providing a basis for optimizing nutritional management pathways for this population. Methods A retrospective study was conducted, including 2 937 elderly patients with multimorbidity. Data on general information, clinical indicators, nutritional risk screening and assessment, nutritional therapy, and costs were collected for descriptive analysis. The relationship between nutritional status (based on BMI and serum albumin levels) and hospitalization outcomes was explored. Results The average age of the patients was (77.45±10.70) years, with 57.17% being male. The average number of chronic diseases diagnosed was (11.56±5.08) per patient, and 26.01% were critically ill. The nutritional risk screening rate was 80.40%, with a screening positivity rate of 33.44%. The nutritional assessment rate was 31.63%, and the malnutrition prevalence was 23.08%. The low BMI group had the longest median hospital stay [15 (9.75, 22) days] and the highest hospitalization costs [15 057.2 (8 980.48, 28 160.46) CNY]. Serum albumin levels were negatively correlated with hospital stay duration (rs=-0.276, P< 0.01) and hospitalization costs (rs=-0.276, P<0.01). Conclusion Hospitalized elderly patients with multimorbidity are characterized by multiple comorbidities and high healthcare resource consumption. While the nutritional risk screening rate is relatively high, there remains room for improvement in nutritional assessment and therapy. It is necessary to strengthen standardized management throughout the entire process. Nutritional status is a significant variable affecting hospital stay duration and costs, with poorer nutritional status significantly associated with prolonged hospitalization and higher costs, suggesting that it may be an important factor influencing hospitalization outcomes.

ObjectiveTo investigate the therapeutic mechanism of artemether in diabetic sarcopenia（DS）using network pharmacology and animal experiments. MethodsPotential active components and therapeutic targets were screened using artemisinin as the parent compound. The predicted targets were intersected with DS-related targets， followed by construction of a protein-protein interaction （PPI） network. Gene Ontology （GO） and Kyoto Encyclopedia of Genes and Genomes （KEGG） enrichment analyses were performed to identify the key biological processes and signaling pathways. Molecular docking was further used to evaluate the binding affinity between artemether and core targets. The DS mouse model was established using db/db mice， followed by artemether intervention. Fasting blood glucose， body weight， diabetes-related symptoms， body composition， grip strength， serum and skeletal muscle triglyceride levels， and muscle fiber cross-sectional area （CSA） were assessed. The expression levels of forkhead box O1 （FoxO1）， Atrogin-1， muscle RING finger protein 1 （MuRF1）， acyl-CoA synthetase short-chain family member 2 （ACSS2）， carnitine palmitoyltransferase 2 （CPT2）， and fatty acid-binding protein 3 （FABP3） in skeletal muscle were detected by qRT-PCR， Western blot， immunofluorescence， and immunohistochemistry. In addition， metabolomics was performed to analyze changes in acylcarnitine metabolites in skeletal muscle. ResultsA total of 68 overlapping targets between artemether and diabetic sarcopenia （DS） were identified. The core targets included AKT1， FoxO1， NFKB1， FBXO32， and TRIM63， which were mainly enriched in the phosphoinositide 3-kinase/protein kinase B （PI3K-Akt） signaling pathway， forkhead box O （FoxO） signWaling pathway， tumor necrosis factor （TNF） signaling pathway， and insulin resistance-related pathways. Molecular docking analysis showed that artemether exhibited favorable binding affinity with the core targets. Animal experiments demonstrated that artemether reduced fasting blood glucose， ameliorated metabolic symptoms， increased lean mass and grip strength， decreased serum and skeletal muscle triglyceride levels， and increased muscle fiber cross-sectional area （CSA） in DS mice. In addition， artemether downregulated the mRNA and protein expression levels of FoxO1， FBXO32/Atrogin-1， TRIM63/MuRF1， ACSS2， CPT2， and FABP3， and improved the disturbance of acylcarnitine metabolism in skeletal muscle. ConclusionArtemether improves metabolic and skeletal muscle phenotypes in DS mice. Its effects may be associated with the amelioration of lipid metabolic disorders and the downregulation of FoxO1 and its downstream ubiquitin-proteasome pathway-related factors Atrogin-1 and MuRF1 in skeletal muscle.

ObjectiveTo observe the clinical efficacy and safety of lung-boosting moxibustion with different moxibustion doses in the treatment of stable chronic obstructive pulmonary disease （COPD）. MethodsA total of 240 stable COPD patients with lung qi deficiency， lung-spleen qi deficiency， or lung-kidney qi deficiency syndrome were enrolled， all receiving standardized western medical treatment and lung-boosting moxibustion. According to the thickness of the moxa wool， the thickness of the ginger paste， and the treatment duration， patients were randomly divided into eight groups， which were Group A （3.0 cm thickness moxa， 2.5 cm ginger mud， 60 min treatment time）， Group B （3.0 cm thickness moxa， 2.5 cm ginger mud， 90 min treatment time）， Group C （2.0 cm thickness moxa， 2.5 cm ginger mud， 60 min treatment time）， Group D （2.0 cm thickness moxa， 2.5 cm ginger mud， 90 min treatment time）， Group E （3.0 cm thickness moxa， 2.0 cm ginger mud， 60 min treatment time）， Group F （3.0 cm thickness moxa， 2.0 cm ginger mud， 90 min treatment time）， Group G （2.0 cm thickness moxa， 2.0 cm ginger mud， 60 min treatment time）， Group H （2.0cm thickness moxa， 2.0cm ginger mud， 90 min treatment time）. Treatment was performed once every 15 days for 3 months， with a total of six sessions. The primary outcomes were the scores of the clinical symptoms and signs questionnaire for stable COPD before and after treatment， comprising seven symptom domains （cough， sputum production， wheezing， chest tightness， shortness of breath， fatigue， and cyanosis） and the total score. The secondary outcomes included the scores of the modified COPD patient-reported outcome questionnaire （mCOPD-PRO） involving the physical， psychological， and environmental domains and the total score， the scores of the modified Effectiveness Satisfaction Questionnaire for COPD （mESQ-COPD） involving clinical symptoms， work and daily living capacity， environmental adaptability， treatment efficacy， and the total score before and after treatment， the moxibustion sensation scores （heat sensation score and special sensation intensity score） during treatment， and cutaneous temperature （the maximum temperature achieved， the duration of temperature maintained at ≥43 ℃， and the time required to reach 43 ℃）. The safety evaluation was carried out after treatment. ResultsDuring the study， 18 patients withdrew， and 222 patients were included in the per-protocol set for analysis， including 27 in Group A， 28 in Group B， 28 in Group C， 29 in Group D， 27 in Group E， 28 in Group F， 27 in Group G， and 28 in Group H. After treatment， the total score on the clinical symptoms and signs questionnaire， as well as the cough and chest tightness symptom scores in Group F were significantly lower than those in other groups （P＜0.05）. Group F demonstrated statistically lower total mCOPD-PRO score and physical domain score （P＜0.05）， lower total mESQ-COPD score and the scores for clinical symptoms and treatment efficacy （P < 0.05）， as well as higher heat sensation score （P＜0.05） than other groups. The maximum temperature was significantly higher in Group E and Group F than in the other groups， while the duration of temperature maintained at ≥43 ℃ was significantly longer in Group F than other groups， and the time required to reach 43 ℃ was significantly shorter in Group E and Group F than in Groups C， D， G， and H （P＜0.05）. No significant abnormalities were observed in routine blood tests， liver function， renal function， urinalysis， or electrocardiograms before and after treatment in any group. No serious adverse events occurred during the treatment period. ConclusionThere are differences in the efficacy of different moxibustion doses of lung-boosting moxibustion in the treatment of stable COPD. Moxibustion with 3.0 cm thickness moxa， 2.0 cm ginger mud， and 90 min treatment time can obtain relatively superior efficacy while demonstrating a favorable safety profile.

ObjectiveTo investigate whether modified Taohe Chengqitang （JTCT） treats liver fibrosis by inhibiting hepatic sinusoidal capillarization， and to verify whether its specific mechanism is related to the Homologous genes responsible for the notches along the edges of Drosophila wings（Notch） signaling pathway and endothelial nitric oxide synthase （eNOS） signaling pathway. MethodsFifty C57BL/6 mice were randomized into 5 groups： Control， model （5 mL·kg^-1·3 d^-1）， low-dose JTCT， medium-dose JTCT， and high-dose JTCT （JTCT-L，JTCT-M，JTCT-H）. Except the control group， the other groups were intraperitoneally injected with 20% carbon tetrachloride （CCl₄） olive oil solution every 3 days for 4 weeks to induce liver fibrosis. Meanwhile， JTCT-L， JTCT-M， and JTCT-H groups were administrated with JTCT by gavage at doses of 16.6， 33.3， and 66.6 g·kg^-1·d^-1， respectively， for 4 consecutive weeks （the control and model groups received equal volumes of normal saline by gavage）. Primary liver sinusoidal endothelial cells （LSECs） were isolated from rat livers through in situ perfusion of collagenase， Percoll density gradient centrifugation， and selective removal of Kupffer cells. After verification of cell phenotype， LSECs were used for experiments. For cells at the logarithmic growth phase， the small interfering RNA（siRNA） kit was used to knock down the expression of soluble guanylate cyclase （sGC） through transient transfection. Subsequently， the Notch agonist Jagged-1 was applied. Cell counting kit-8 （CCK-8） was used to examine the cytotoxicity of JTCT on LSECs. Real-time PCR and Western blot were employed to measure the expression of molecules in the Notch and eNOS signaling pathways at mRNA and protein levels， respectively. Intracellular Ca²⁺ was labeled with the fluorescent probe Fluo-4 acetoxymethyl ester（Fluo-4/AM）. ResultsThe animal experiment showed that compared with the control group， the model group exhibited hepatic steatosis， inflammatory cell infiltration， hepatocyte degeneration and necrosis， lobular structural disorder， and fibrous tissue hyperplasia in the mouse liver tissue， significantly elevated serum levels of hydroxyproline （Hyp）， alanine transaminase （ALT）， and aspartate transaminase （AST） （P<0.01）， significantly upregulated expression levels of Notch1， Hes family bHLH transcription factor 1（Hes1）， Cluster of Differentiation 31（CD31）， and von Willebrand factor（vWF） （P<0.01）， and significantly downregulated phosphorylate（p）-eNOS/eNOS ratio and sGC expression （P<0.01）. Compared with the model group， all the JTCT groups showed significantly reduced serum Hyp， ALT， and AST levels （P<0.01）， downregulated expression of Notch1， Hes1， CD31， and vWF （P<0.05， P<0.01）， and upregulated p-eNOS/eNOS ratio and sGC expression （P<0.05， P<0.01） in the liver tissue， with the JTCT-H group showing the most significant changes （P<0.01）. The cell experiment showed that compared with the LSEC-1day group， the LSEC-5day group exhibited significantly increased expression of Notch1， Hes1， CD31， and vWF （P<0.01）， significantly decreased p-eNOS/eNOS ratio and sGC expression （P<0.01）， and elevated intracellular Ca²⁺ concentration （P<0.01）. Compared with the LSEC-5day group， the JTCT group showed decreased expression of Notch1， Hes1， CD31， and vWF （P<0.01）， significantly increased p-eNOS/eNOS ratio （P<0.01）， and significantly reduced intracellular Ca²⁺ concentration （P<0.01）. No significant differences were observed in the expression of Notch1， Hes1， eNOS， p-eNOS， CD31， vWF， sGC， or intracellular Ca²⁺ concentration between the Jagged1 group and the Jagged1+JTCT group. Compared with the LSEC-5day group， the sGC knockout group （sGC-KO） showed significantly increased expression of CD31 and vWF （P<0.01）. There was no significant difference in CD31 or vWF expression between the sGC-KO group and the sGC-KO+JTCT group. ConclusionJTCT inhibits the activation of the Notch signaling pathway and restores the activity of the eNOS signaling pathway to suppress sinusoidal capillarization of LSECs， thereby treating liver fibrosis.

BACKGROUND:Peripheral nerve axon rupture seriously affects patients' physical function and mental health.Microsurgery,nerve autograft,nerve allograft,fibrin glue and catheter technology are the main treatments for peripheral nerve injury,each of which has its own advantages and disadvantages,but the overall treatment effect is not satisfactory.Despite the clinical success of Schwann cells in promoting axonal regeneration,there are still many challenges in the treatment with Schwann cells,such as slow expansion of Schwann cells,immune rejection,and low survival rate of transplanted cells.OBJECTIVE:To summarize the role and mechanism of Schwann cells in promoting the regeneration of peripheral nerve axons,and the difficulties and challenges of Schwann cells in the process of nerve regeneration treatment.METHODS:PubMed,Medline,WanFang,VIP,and CNKI were searched by computer using the search terms of"Schwann cells,synaptic Schwann cell,macrophage,peripheral nerve axon rupture,Wallerian degeneration,Peripheral nerve axon regeneration,Central nervous system repair"in English and Chinese.Literature related to Schwann cell proliferation and differentiation,promotion of peripheral nerve regeneration,and clinical applications was retrieved from database inception to October 2024,and a total of 95 articles were finally included for review.RESULTS AND CONCLUSION:Schwann cells interact with macrophages,T cells and other cells,to initiate the regeneration process through signaling pathways,including Krox20/C-Jun,NRG-1/ErbB,Notch,MAPK,and PI3K/Akt/mTOR,synthesize and release nerve growth factors,and thus promote regeneration of the peripheral nervous system.Schwann cells have been experimentally demonstrated to have great potential in peripheral nerve repair and are expected to become the key target of therapeutic intervention.However,there are still problems such as difficulties in cell harvest and culture,as well as the occurrence of other diseases during the treatment process.

BACKGROUND:Cell-free therapy is a research hotspot in the field of medical cosmetic anti-aging.It is still unknown for paracellular secretion of human umbilical cord mesenchymal stem cell-derived small extracellular vesicles loaded with the antiaging drug α-ketoglutaric acid to delay skin aging.OBJECTIVE:To investigate the effect of the anti-aging agent α-ketoglutarate engineered human umbilical cord mesenchymal stem cell-derived small extracellular vesicles in a D-galactose-induced model of dermal fibroblast senescence.METHODS:(1)Biological characteristics of primary human umbilical cord mesenchymal stem cells were identified by osteogenic-lipogenic differentiation staining and flow cytometry.(2)The small extracellular vesicles derived from human umbilical cord mesenchymal stem cell were obtained by using differential-ultracentrifugation.α-Ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles were constructed by electroporation,and biologically characterized by transmission electron microscopy and nanoparticle tracking analyzer,while the encapsulation rate was assessed using high-performance liquid chromatography.(3)The effect of α-ketoglutarate on the proliferative capacity of dermal fibroblasts was assessed by CCK-8 and Edu cell proliferation assay kits.(4)The effect of α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles on delaying the senescence of dermal fibroblasts was evaluated by reactive oxygen species detection kit,western blot assay,and cellular immunofluorescence.RESULTS AND CONCLUSION:(1)The obtained human umbilical cord mesenchymal stem cell and human umbilical cord mesenchymal stem cell-small extracellular vesicles were biologically compatible.(2)There was no toxic effect on dermal fibroblasts when α-ketoglutarate was used in the concentration range of 0.5-8 mmol/L.(3)D-gal induced senescence in dermal fibroblasts,while α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles treatment reduced the level of oxidative stress,DNA damage,and collagen loss,which was further verified that α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles could effectively slow down the skin aging process.