BACKGROUND:Muscle aging is closely related to various epigenetic changes,and exercise has a certain regulatory effect on these epigenetic changes.However,the specific mechanism is not fully understood. OBJECTIVE:To review the epigenetic mechanisms of skeletal muscle and how exercise can improve skeletal muscle aging and promote adaptive changes in muscle through these epigenetic mechanisms,aiming to provide a more comprehensive understanding of skeletal muscle aging and disease mechanisms. METHODS:During the period from June 1st to August 1st,2023,literature searches were conducted for relevant literature published from database inception to August 2023 in databases including Web of Science,PubMed,CNKI,WanFang,and VIP.The search terms used included"skeletal muscle,""muscle,""aging,""older adult,""aging,""exercise,""physical exercise,""epigenetic,"and"epigenetics"in Chinese as well as"skeletal muscle,muscle,aging,older adult,senescence,age,exercise,sports,physical activity,epigenetic,epigenetics"in English.Boolean logic operators were used to connect the search terms for retrieval,and corresponding strategies were developed.According to the predetermined inclusion and exclusion criteria,70 eligible articles were selected. RESULTS AND CONCLUSION:Epigenetics refers to the phenomenon where gene expression and function are regulated without changes in gene sequence,and epigenetic changes in skeletal muscle are an important field.The epigenetic mechanisms of skeletal muscle play an important role in muscle aging,mainly involving DNA methylation,histone modification,regulation of non-coding RNAs,chromatin remodeling,changes in mitochondrial function and expression changes of aging-related genes.Exercise significantly regulates the epigenetics of skeletal muscle,including promoting DNA methylation,muscle histone modification,regulating miRNA expression,and regulating lncRNA expression,regulating muscle factors(such as interleukin-6),regulating mitochondrial function(such as peroxisome proliferators-activated receptors γ co-activator 1α).Future studies are recommended for long-term,cross-diverse population-based exercise interventions;the application of multi-omics techniques such as proteomics and metabolomics;strengthening the understanding of epigenetic changes at the single-cell level;cross-species comparative studies as well as human clinical trials for the translation of animal model findings to humans;strategies for combining exercise and pharmacological interventions to assess their synergistic effects;and epigenetic studies of crosstalk interactions between skeletal muscle and different organs.

Objective: To explore effects of cumulative family risk in university students on individuals internalizing problems, to elucidate the mediating roles of perceived social support and self esteem in the relationship, so as to provide a basis for promoting university student s mental health. Methods: Using longitudinal design, 1 207 freshmen from a university in Tianjin were randomly selected and surveyed in November 2023 (T1) and November 2024 (T2). The instruments included the Cumulative Family Risk Scale, the Perceived Social Support Scale, the Self esteem Scale, and the College Student Mental Health Screening Scale. Structural equation modeling (SEM) was constructed, with Bootstrap method used to test mediating effects and to examine gender differences. Results: The results showed that cumulative family risk at T1 with internalizing problems at T1( r =0.30) and internalizing problems at T2 ( r =0.32) were significantly positively correlated (both P <0.01). Mediation analysis indicated that the independent mediating effect of perceived social support at T1，cumulative family risk at T1 and internalizing problems at T2 was 0.03 (95% CI =0.02-0.05), and the independent mediating effect of self esteem at T1 was 0.08 (95% CI = 0.06 -0.10) (both P <0.05). The chain mediating effect of perceived social support and self esteem at T1 was 0.02 (95% CI =0.02-0.03) ( P <0.05). Significant gender differences were observed in the path from cumulative family risk to self esteem ( β male =-0.24, β female =-0.35) and in the path from perceived social support to self esteem ( β male =0.41, β female =0.25) (all P <0.05). Conclusion Cumulative family risk reduces internalizing behaviors in university students via internal and external development resources, with gender specific mechanisms.

Objective:To compare the effect of self-radiopaque markers guiding physician-modified fenestration, chimney technique and hybrid Ⅳb technique on reconstruction of left subclavian artery (LSA) in endovascular treatment of aortic dissection (TEVAR).Methods:The clinical and follow-up data of 312 TEVAR patients treated with LSA blood supply reconstruction technology from Jan 2016 to Dec 2019 at Fuwai hospital were retrospectively analyzed.Results:There were 35 patients in the hybrid Ⅳb technique group, 93 in the chimney technique group, and 184 in the in vitro fenestration group. The follow-up period ranged from 12 to 24 months. No artificial blood vessel and stent occlusion occurred in all patients during follow-up, and the LSA blood flow was unobstructed. A total of 19 patients had endoleak by the last follow-up, and there was no statistical difference between the three groups. Eleven patients underwent reintervention surgery, all were from chimney technique group and in vitro fenestration group, with no statistical difference ( P>0.05). Severe complications occurred in 28 patients during hospitalization, and the incidence of complications was the highest in the hybrid Ⅳb technique group ( P<0.01). During follow-up, 4 patients died in the bypass group, 6 died in the external window group, and 8 died in the chimney group, with no significant difference ( P>0.05). Conclusions:The safety and efficacy of the left subclavian artery flow reconstruction by in vitro fenestration and chimney technique were similar. The occurrences of early complications were lower than that of the hybrid Ⅳb technique, but the reintervention rate of endoleak was higher.

Purpose To explore the application value of contrast enhancement boost(CE-Boost)technique in image quality of tumors and their feeding arteries in preoperative evaluation of renal cancer patients.Materials and Methods A total of 36 renal cancer patients in People's Hospital Affiliated to Shandong First Medical University from August 2022 to May 2023 with pathologically confirmed were retrospective collected.All patients underwent renal enhanced CT.The cortical phase images were post-processed using the CE-Boost technique to obtain CE-Boost images.The cortical phase images were set as group A and the CE-Boost images were set as group B.The CT value and image noise(SD)of abdominal aorta,renal artery,tumor and its adjacent renal cortex,and SD of the vertical spinal muscle on both sides of the spine of two groups were measured and recorded,and then the signal-to-noise ratio and contrast-to-noise ratio of tumor,abdominal aorta and renal artery were calculated.The image quality of the tumor,tumor feeding artery and renal artery was scored on 4 points by 2 doctors with double-blind method.Results The signal-to-noise ratio,contrast-to-noise ratio and CT value of group B were significantly higher than those of group A(t=-27.385--5.267,all P<0.05).The SD of tumor,abdominal aorta,right and left renal artery were not significantly different between group A and B(t=-1.849-0.993,all P>0.05).The subjective score of tumor in group A and B were no significant difference(Z=-1.490,P=0.136).However,the subjective score of tumor feeding arteries and renal arteries were significantly higher in group B than in group A(Z=-3.512,P=0.000;Z=-2.127,P=0.033).Conclusion The CT CE-Boost technique can improve the image quality of renal enhanced CT and provide visualization of tumor feeding arteries.

OBJECTIVE To establish the characteristic chromatogram of the volatile oil in the standard decoction of Qingshang juantong decoction， and preliminarily infer the main active components of volatile oil that affect the clinical therapeutic effect. METHODS The volatile oil in the standard decoction of Qingshang juantong decoction was extracted by steam distillation. The ultra-high performance liquid chromatography （UPLC） characteristic chromatograms of 15 batches of samples were established by the Similarity Evaluation System of TCM Chromatographic Fingerprint （2012 edition）， and the similarity evaluation was carried out. The volatile oil of standard decoction was identified by UPLC coupled with quadrupole time-of-flight mass spectrometry （UPLC-Q-TOF/MS）. Then the volatile oil components were analyzed by GC-MS. RESULTS The similarities of UPLC characteristic chromatograms for volatile oil of 15 batches of Qingshang juantong decoction were between 0.949 and 0.997. A total of 12 common peaks were obtained. According to the UPLC-Q-TOF/MS， the main components were methyl eugenol， E-ligustilide， E-butylidenephthalide and so on. A total of 23 components were identified by GC-MS， which were mainly 3，4，5-trimethoxy- methylbenzene， patchouli alcohol， Z-ligustilide and so on. CONCLUSIONS The characteristic chromatograms of the volatile oil in the standard decoction of Qingshang juantong decoction is established， and it is inferred that methyl eugenol， ligustilide， E- butylidenephthalide， patchouli alcohol， 3，4，5-trimethoxy-methylbenzene might be the main active components affecting the clinical therapeutic effect of the volatile oil of Qingshang juantong decoction.

Objective To explore the effect of cannabinoid receptor 2(CB2)on orthodontic tooth movement(OTM)rate and periodontal tissue reconstruction of pressure area in mice.Methods Thirty CB2-/-male mice and thirty littermate control WT male mice were individually accepted the orthodontic appliance at their age of 6 weeks.The mice were respectively scarified at 3 days,7 days,14 days and 21 days after the operation.Then the tooth movement distance was examined through the stereomicroscope.Hematoxylin-eosin staining was performed to explore the biological responses of periodontium at the distal mesial root pressure area.Anti-tartrate acid phospha-tase staining was performed to calculate the number and distribution of osteoclasts at the distal mesial root pressure area,and MMP-9 was evaluated by immunohistochemistry to examine the number of MMP-9(+)monocytes and multinucleated cells in the same district as the TRAP staining.Results Compared with those WT mice at 3,7,14 and 21 days,OTM distance showed a gradual increased tendency according with experimental time over 21 days.The widths of periodontal ligament on the pressure side were markedly greater in CB2-/-mice than WT mice at 7,14 and 21 days(P＜0.000 1).The numbers of TRAP positive osteoclasts were significantly greater in CB2-/-mice than those in WT mice at 14 days of OTM(P＜0.001).MMP-9 immunohistochemical staining showed that the number of MMP-9(+)monocytes and multinucleated cells was more in CB2-/-mice than that in WT mice at 14 days of OTM(P＜0.05).Conclusion The absence of CB2 accelerates orthodontic tooth movement under or-thodontic force.The absence of CB2 reinforces bone resorption in orthodontic tooth movement compressive area dur-ing orthodontic tooth movement.

Objective To investigate the feasibility of low-voltage,automatic tube current adjustment(ATCM)and low contrast agent concentration,dose and injection rate combined with full-model iterative re-construction(IMR)in vertebral artery V3-segment three-dimensional CT angiography(3DCTA).Methods A total of 60 patients with suspected upper cervical spine,craniocervical junction lesions undergoing cervical vertebral artery V3 segment 3DCTA in this hospital from November 2019 to May 2020 were selected and divided into the group A and B by adopting the random number table method,30 cases in each group.The group A adopted the ATCM technology of 80 kV,average tube current of 50 mAs,25 mL of contrast agent io-hexol(iodine content 300 mg/mL)combined IMR technology with an injection rate of 3 mL/s,while the group B adopted 120 kV,150 mAs fixed tube current,50 mL injection rate of 5 mL/s contrast agent iopamidol(iodine content 370 mg/mL)combined filter back projection(FBP)reconstruction technology.CT value,noise,signal-to-noise ratio(SNR),contrast noise ratio(CNR)and image sensitivity(FOM)were measured and compared between the two groups and the quality of the resulting images was evaluated.The CT volumet-ric dose index(CTDIvol)and dose-length product(DLP)were recorded,and the effective dose(ED)was cal-culated.Results There was no statistically significant difference in the vertebral arterial CT value between the two groups(P＞0.05),but the noise of the group A was lower than that of the group B(P＜0.05),SNR,CNR and FOM of the group A were greater than those of the group B(P＜0.05).The image quality of the two groups met the requirements of clinical diagnosis[(4.78±0.41)points vs.(4.85±0.35)points],and there was no statistically significant difference in the subjective evaluation of image quality(P＞0.05).The CTDIvol,DLP and ED levels in the group A were lower than those in the group B(P＜0.05).The iodine in-takes of contrast medium in the group A and group B were 7.5 g and 18.5 g,respectively,and the iodine flow rates of contrast agent were 0.9 and 1.85 mg/s,respectively,and compared with group B,the iodine intake and iodine flow rate of the group A were decreased by 59.5％and 51.4％,respectively.Conclusion Low tube voltage ATCM and low contrast concentration,dose and injection rate combined with IMR technology can not only ensure the 3DCTA image quality of vertebral artery V3 segment,but also reduce the radiation dose re-ceived by the patients,and reduce the iodine intake and iodine flow rate of contrast agent.

BACKGROUND:Reactive oxygen species is a double-edged sword in the development of periodontitis and the regeneration of periodontal tissue.Low concentration of reactive oxygen species induces the differentiation of periodontal fibroblasts,and excessive reactive oxygen species will cause damage to periodontal tissue.In the process of inflammation,the accumulation of reactive oxygen species in periodontal tissue induces damage to cells and tissues through a variety of signaling pathways or through redox reactions. OBJECTIVE:To review the double-edged sword effect of reactive oxygen species in periodontitis and periodontal tissue regeneration,thereby providing potential targets and treatment ideas for the clinical treatment of periodontitis and periodontal tissue regeneration. METHODS:Databases of CNKI and PubMed were searched for relevant articles published from April 1990 to April 2023 with the key words of"periodontal tissue engineering,periodontal defect,regeneration of periodontal tissue,chronic periodontitis,reactive oxygen species,oxidative stress,antioxidative stress,oxidative injuries,free radicals,reactive nitrogen species"in Chinese and English,respectively.By reading the titles and abstracts,repetitive studies or irrelevant literatures were excluded.Finally,77 articles were included for review. RESULTS AND CONCLUSION:Reactive oxygen species are a kind of free radicals with high reactivity.When bacteria invade,reactive oxygen species are released in large quantities by the respiratory explosion of neutrophils and play a double-edged sword role in the body through their redox reactions or as pleiotropic physiological signal transmitters.In periodontitis,low concentrations of reactive oxygen species can kill invading pathogenic bacteria,but high concentrations of reactive oxygen species promote the secretion of inflammatory factors through JNK,RANK,Wnt/β-Catenin and other pathways,promote immune damage or directly damage tissues through oxidative reactions or through other ways to aggravate periodontitis.In the process of periodontal tissue regeneration,low concentrations of reactive oxygen species can promote the proliferation and differentiation of periodontal ligament stem cells through Nrf2 and other pathways and can promote the secretion of vascular endothelial growth factor to promote vascular regeneration.This provides seeds and a nutrient environment for periodontal tissue regeneration,which is extremely important for promoting periodontal tissue regeneration.However,high concentrations of reactive oxygen species will reduce the activity of periodontal ligament stem cells and damage endothelial cells,which are not conducive to vascular regeneration.This will inhibit wound healing and periodontal tissue regeneration.Therefore,it is important to explore the role of reactive oxygen species in the development of periodontitis and periodontal tissue regeneration and to discover the potential mechanism of its action and to explore the appropriate concentration for its role in reducing periodontal inflammation and promoting periodontal tissue regeneration for the future treatment of periodontitis and periodontal tissue regeneration in clinical practice.Using reactive oxygen species as a target to explore ways to reduce periodontal inflammation and promote periodontal ligament stem cell activity and vascular regeneration may become a clinically effective method for treating periodontitis and promoting periodontal tissue regeneration.

Objective:To study the current status of longitudinal extrauterine growth restriction (EUGR) in extremely preterm infants (EPIs) and to develop a prediction model based on clinical data from multiple NICUs.Methods:From January 2017 to December 2018, EPIs admitted to 32 NICUs in North China were retrospectively studied. Their general conditions, nutritional support, complications during hospitalization and weight changes were reviewed. Weight loss between birth and discharge > 1SD was defined as longitudinal EUGR. The EPIs were assigned into longitudinal EUGR group and non-EUGR group and their nutritional support and weight changes were compared. The EPIs were randomly assigned into the training dataset and the validation dataset with a ratio of 7∶3. Univariate Cox regression analysis and multiple regression analysis were used in the training dataset to select the independent predictive factors. The best-fitting Nomogram model predicting longitudinal EUGR was established based on Akaike Information Criterion. The model was evaluated for discrimination efficacy, calibration and clinical decision curve analysis.Results:A total of 436 EPIs were included in this study, with a mean gestational age of (26.9±0.9) weeks and a birth weight of (989±171) g. The incidence of longitudinal EUGR was 82.3%(359/436). Seven variables (birth weight Z-score, weight loss, weight growth velocity, the proportion of breast milk ≥75% within 3 d before discharge, invasive mechanical ventilation ≥7 d, maternal antenatal corticosteroids use and bronchopulmonary dysplasia) were selected to establish the prediction model. The area under the receiver operating characteristic curve of the training dataset and the validation dataset were 0.870 (95% CI 0.820-0.920) and 0.879 (95% CI 0.815-0.942), suggesting good discrimination efficacy. The calibration curve indicated a good fit of the model ( P>0.05). The decision curve analysis showed positive net benefits at all thresholds. Conclusions:Currently, EPIs have a high incidence of longitudinal EUGR. The prediction model is helpful for early identification and intervention for EPIs with higher risks of longitudinal EUGR. It is necessary to expand the sample size and conduct prospective studies to optimize and validate the prediction model in the future.

Objective To investigate the association between microvariants at locus DYS570 and Y-SNPs haplogroup.Methods 89 Y-SNPs and 34 Y-STRs in AIYSNP42,AIYSNP47 and YfilerTM Platinum kits were used to detect the genotype of 116 microvariants at locus DYS570 in Kunming,and the Set-B kit was used to detect the core repeat sequences of the DYS570 locus.The data were statistically analyzed by direct counting method.Then,a network map was drawn by Network 10.2,in order to visualize the genetic information of the sample.Results The results demonstrated that 111 DYS570/18.3-21.3 samples had a core repeat sequence of TTT[TITC]18-21,belonging to subgroup O2a2b1a1a1a4-F14494.A DYS570/20.3 sample had a core repeat sequence of[TTTC]15TTC[TTTC]5,belonging to O2a1b1a1a1a1e-F1365 subgroup.A DYS570/17.1 sample had a core repeat sequence of[TTTC]17 T,belonging to the O2a1b1a1a1a-F11 subgroup.Three DYS570(19.2)samples had[TTTC]3 TT[TTTC]16,belonging to the D1a1a-M15 haplogroup.Conclusion The results indicated that the microvariant with the same core repeat structure at locus DYS570 was associated with haplogroups,and the ancestry origin of samples can be inferenced from microvariant characteristics during the practice of forensic medicine.