Circadian rhythm is an endogenous biological clock mechanism that enables organisms to adapt to the earth’s alternation of day and night. It plays a fundamental role in regulating physiological functions and behavioral patterns, such as sleep, feeding, hormone levels and body temperature. By aligning these processes with environmental changes, circadian rhythm plays a pivotal role in maintaining homeostasis and promoting optimal health. However, modern lifestyles, characterized by irregular work schedules and pervasive exposure to artificial light, have disrupted these rhythms for many individuals. Such disruptions have been linked to a variety of health problems, including sleep disorders, metabolic syndromes, cardiovascular diseases, and immune dysfunction, underscoring the critical role of circadian rhythm in human health. Among the numerous systems influenced by circadian rhythm, the skin—a multifunctional organ and the largest by surface area—is particularly noteworthy. As the body’s first line of defense against environmental insults such as UV radiation, pollutants, and pathogens, the skin is highly affected by changes in circadian rhythm. Circadian rhythm regulates multiple skin-related processes, including cyclic changes in cell proliferation, differentiation, and apoptosis, as well as DNA repair mechanisms and antioxidant defenses. For instance, studies have shown that keratinocyte proliferation peaks during the night, coinciding with reduced environmental stress, while DNA repair mechanisms are most active during the day to counteract UV-induced damage. This temporal coordination highlights the critical role of circadian rhythms in preserving skin integrity and function. Beyond maintaining homeostasis, circadian rhythm is also pivotal in the skin’s repair and regeneration processes following injury. Skin regeneration is a complex, multi-stage process involving hemostasis, inflammation, proliferation, and remodeling, all of which are influenced by circadian regulation. Key cellular activities, such as fibroblast migration, keratinocyte activation, and extracellular matrix remodeling, are modulated by the circadian clock, ensuring that repair processes occur with optimal efficiency. Additionally, circadian rhythm regulates the secretion of cytokines and growth factors, which are critical for coordinating cellular communication and orchestrating tissue regeneration. Disruptions to these rhythms can impair the repair process, leading to delayed wound healing, increased scarring, or chronic inflammatory conditions. The aim of this review is to synthesize recent information on the interactions between circadian rhythms and skin physiology, with a particular focus on skin tissue repair and regeneration. Molecular mechanisms of circadian regulation in skin cells, including the role of core clock genes such as Clock, Bmal1, Per and Cry. These genes control the expression of downstream effectors involved in cell cycle regulation, DNA repair, oxidative stress response and inflammatory pathways. By understanding how these mechanisms operate in healthy and diseased states, we can discover new insights into the temporal dynamics of skin regeneration. In addition, by exploring the therapeutic potential of circadian biology in enhancing skin repair and regeneration, strategies such as topical medications that can be applied in a time-limited manner, phototherapy that is synchronized with circadian rhythms, and pharmacological modulation of clock genes are expected to optimize clinical outcomes. Interventions based on the skin’s natural rhythms can provide a personalized and efficient approach to promote skin regeneration and recovery. This review not only introduces the important role of circadian rhythms in skin biology, but also provides a new idea for future innovative therapies and regenerative medicine based on circadian rhythms.

Objective To explore the protective mechanism of icariin on neuronal oxidative damage,providing a basic pharmacological basis for the treatment of cognitive impairment.Methods Glutamate was used to induce oxidative stress injury in HT22 cells.HT22 cells were divided into control group(normal cultured cells),model group(glutamate injury model)and experimental-L,-M,-H groups(5,10 and 20 μmol·L-1 icariin pretreatment for modeling,respectively).Cell proliferation was detected by cell counting kit-8(CCK-8)method;cytotoxicity was detected by lactate dehydrogenase(LDH)method;reactive oxygen species(ROS)levels were detected by flow cytometry;superoxide dismutase(SOD)levels were detected by biochemical kits;the expression levels of Kelch-like epichlorohydrin-related protein-1(Keap1),nuclear factor E2-related factor 2(Nrf2)were detected by Western blotting;the corresponding mRNA expression was detected by real-time fluorescence quantification polymerose chain reaction.Results The cell viability of control group,model group and experimental-L,-M,-H groups were(100.00±1.31)％,(66.38±2.44)％,(72.07±4.95)％,(82.41±3.57)％and(87.97±4.98)％;LDH release were(0.48±0.52)％,(18.82±2.09)％,(15.32±1.17)％,(10.37±1.39)％and(6.51±0.87)％;ROS level were(14.23±1.13)％,(41.74±1.60)％,(35.69±1.08)％,(33.28±1.69)％and(30.32±2.03)％;SOD levels were(54.84±1.17),(37.95±1.13),(48.02±1.28),(50.56±1.34)and(52.55±1.04)U·mg-1;Keap1 protein levels were 0.36±0.01,0.52±0.03,0.46±0.04,0.39±0.09 and 0.35±0.12;Nrf2 protein levels were 0.29±0.02,0.13±0.08,0.18±0.03,0.21±0.11 and 0.26±0.04;catalase(CAT)mRNA levels were 1.01±0.08,0.81±0.06,0.90±0.04,1.05±0.15 and 1.33±0.26;SOD mRNA levels were 1.09±0.12,0.83±0.03,0.86±0.08,0.94±0.08 and 1.09±0.16.Among the above indicators,the differences between the model group and the control group were statistically significant(all P＜0.01);the differences between the experimental-M,-H groups and the model group were statistically significant(P＜0.01,P＜0.05).Conclusion Icariin may activate the Keap1/Nrf2/antioxidant response element(ARE)signaling pathway,regulate the expression of related proteins,and reduce the level of ROS to effectively alleviate oxidative stress injury in neuronal cells.

Objective To investigate the protective effect and mechanism of acellular nerve allografts(ANA)combined with electroacupuncture on spinal ganglia in rats with sciatic nerve injury(SNI).Methods Totally 50 male adult SD rats were randomly selected for this experiment.Ten rats were prepared for the ANA.Forty male SD rats were randomly divided into normal group,model group,ANA group and combinational group,with 10 rats in each group.The SNI model was established by cutting off the nerves 10 mm at the 5 mm on the inferior border of piriformis after separating the right sciatic nerves.The rats in the ANA group were bridged with ANA to the two broken ends of injured nerves.The rats in the combinational group were treated with electroacupuncture 2 days after ANA bridging,Huantiao(GB30)and Yanglingquan(GB34)were performed as the acupuncture points,each electroacupuncture lasted 15 minutes and 7 days as a course of treatment,4 courses in all.Sciatic nerve conduction velocity was measured by electrophysiology to evaluate the regeneration of damaged axons.Morphology of spinal ganglia was observed by Nissl staining.The expression of nerve growth factor(NGF)and brain-derived neurotrophic factor(BDNF)were detected by Western blotting and immunofluorescent staining.Results Compared with the normal group,the sciatic nerve conduction velocity in model group decreased significantly(P<0.01),Nissl bodies in neurons of spinal ganglia were swollen and dissolved,with incomplete structure and the number decreased dramatically(P<0.01),while the level of NGF and BDNF also decreased significantly(P<0.01).Compared with the model group,the sciatic nerve conduction velocity in ANA and combinational groups strongly increased(P<0.01),the damage of Nissl bodies in neurons of spinal ganglia reduced and the number obviously increased(P<0.01),the level of NGF and BDNF increased considerably(P<0.01).Compared with the ANA group,the sciatic nerve conduction velocity in combinational group increased significantly(P<0.01),the morphology of Nissl bodies in neurons of spinal ganglia were more regular and the number increased(P<0.01),moreover,the level of NGF also increased significantly(P<0.01).Conclusion ANA combined with electroacupuncture can enhance the sciatic nerve conduction velocity,improve the morphology of neurons in spinal ganglia and play a protective effect on spinal ganglia.The mechanism can be related to the higher expression of NGF and BDNF proteins,especially the expression of NGF protein.

Osteoarthritis (OA) is a chronic degenerative joint disease and the most common type of arthritis. It involves almost any joint and can lead to chronic pain and disability. In the late 19th century, Roentgen discovered X-rays, and then began to use radiotherapy to treat tumors. In the 1980s, Luckey thought that low-level radiation (LDRT) might be beneficial to biology, and it was gradually applied to the treatment of some diseases. This paper introduces the epidemiology, risk factors, clinical manifestations and treatment methods of OA, points out that the cartilage injury and the important effect of synovial inflammation in the pathogenesis of OA, namely when the homeostasis of articular cartilage are destroyed, synthetic metabolism and catabolism imbalances, cartilage cells damaged their breakdown products consumed by synovial cells. Synovial cells and synovial macrophages secrete proinflammatory cytokines, metalloproteinases and proteolytic enzymes, leading to cartilage matrix degradation and chondrocyte damage, which aggravates synovial inflammation and cartilage damage, forming a vicious cycle. The possible mechanism and clinical research progress of LDRT in alleviating OA are discussed. LDRT can regulate inflammatory response, inhibit the production of pro-inflammatory cytokines, and promote the production of anti-inflammatory cytokines, thereby achieving anti-inflammatory effect. Studies have shown that after irradiation, the expression of inducible nitric oxide synthase (iNOS) was decreased, the release of reactive oxygen species (ROS) and the production of superoxide were inhibited, the anti-inflammatory phenotype of macrophages was differentiated from M1 to M2, the inflammatory CD8⁺ T cells were transformed into CD4⁺ T cells, and the number of dendritic cells (DC) was significantly reduced. LDRT inhibit the production of proinflammatory factors in leukocytes, reduce their recruitment and adhesion, and down-regulate the expression levels of cell adhesion molecules such as selectin, intercellular adhesion molecule (ICAM) and vascular endothelial cell adhesion molecule (VCAM). LDRT can regulate endothelial cells, stimulate endothelial cells to produce a large amount of TGF-β1, reduce the adhesion of endothelial cells to peripheral blood mononuclear cells (PBMC), and contribute to the anti-inflammatory effect of LDRT. It also exerted anti-inflammatory effects by regulating mitochondrial growth differentiation factor 15 (GDF15). After low-level radiation, the MMP-13 (matrix metalloproteinases-13) and the ADAMTS5 (recombinant a disintegrin and metalloproteinase with thrombospondin-5) decreased, the Col2a1 (collagen type 2) increased in chondrocytes. In the existing clinical studies, most patients can achieve relief of joint pain and recovery of joint mobility after irradiation, and the patients have good feedback on the efficacy. The adverse reactions (acute reactions and carcinogenic risks) caused by LDRT in the treatment of OA are also discussed. During the treatment of OA, a few patients have symptoms such as redness, dryness or itching at the joint skin, and the symptoms are mild and do not require further treatment. Patients are thus able to tolerate more frequent and longer doses of radiotherapy. In general, LDRT itself has the advantages of non-invasive, less adverse reactions, and shows the effect of pain relief and movement improvement in the treatment of OA. Therefore, LDRT has a broad application prospect in the treatment of OA.

Objective:To investigate the current situation of the use of transjugular intrahepatic portosystemic shunt (TIPS) for portal hypertension, which should aid the development of TIPS in China.Methods:The China Portal Hypertension Alliance (CHESS) initiated this study that comprehensively investigated the basic situation of TIPS for portal hypertension in China through network research. The survey included the following: the number of surgical cases, main indications, the development of Early-TIPS, TIPS for portal vein cavernous transformation, collateral circulation embolization, intraoperative portal pressure gradient measurement, commonly used stent types, conventional anticoagulation and time, postoperative follow-up, obstacles, and the application of domestic instruments.Results:According to the survey, a total of 13 527 TIPS operations were carried out in 545 hospitals participating in the survey in 2021, and 94.1% of the hospital had the habit of routine follow-up after TIPS. Most hospitals believed that the main indications of TIPS were the control of acute bleeding (42.6%) and the prevention of rebleeding (40.7%). 48.1% of the teams carried out early or priority TIPS, 53.0% of the teams carried out TIPS for the cavernous transformation of the portal vein, and 81.0% chose routine embolization of collateral circulation during operation. Most of them used coils and biological glue as embolic materials, and 78.5% of the team routinely performed intraoperative portal pressure gradient measurements. In selecting TIPS stents, 57.1% of the hospitals woulel choose Viator-specific stents, 57.2% woulel choose conventional anticoagulation after TIPS, and the duration of anticoagulation was between 3-6 months (55.4%). The limitation of TIPS surgery was mainly due to cost (72.3%) and insufficient understanding of doctors in related departments (77.4%). Most teams accepted the domestic instruments used in TIPS (92.7%).Conclusions:This survey shows that TIPS treatment is an essential part of treating portal hypertension in China. The total number of TIPS cases is far from that of patients with portal hypertension. In the future, it is still necessary to popularize TIPS technology and further standardize surgical indications, routine operations, and instrument application.

Objective This study aimed to identify PAX9 variants in non-syndromic tooth agenesis families of Chi-na,as well as to analyze the genotype-phenotype of non-syndromic tooth agenesis caused by PAX9 variants,which can provide a basis for the genetic diagnosis of tooth agenesis.Methods We collected the data of 44 patients with non-syn-dromic oligodontia who underwent treatment at Stomatological Hospital of Hebei Medical University between 2018 and 2023.Whole-exome sequencing was performed on the peripheral blood of the proband and its core family members,and the variants were verified by Sanger sequencing.Pathogenicity analysis and function prediction of the variants were per-formed using bioinformatics tools.The correlation between the genotype of PAX9 variant and its corresponding pheno-type was examined by reviewing 55 publications retrieved from PubMed.The studies involved 232 tooth agenesis pa-tients with PAX9 variants.Results A novel PAX9 c.447delG(p.Pro150Argfs*62)and a reported PAX9 c.406C>T(p.Gln136*)were identified in two Chinese families.Through bioinformatics analysis and three-dimensional structural mod-eling,we postulated that the frameshift variant was pathogenic.The outcome was the premature cessation of PAX9 pro-tein,which caused severe structural and functional deficiencies.Summarizing the PAX9 genotype-phenotype relationship revealed that patients carrying the PAX9 variant commonly led to loss of the second molars.Conclusion We identified the novel PAX9 c.447delG(p.Pro150Argfs*62)in a Chinese family of non-syndromic oligodontia,expanding the known variant spectrum of PAX9.The most susceptible tooth position for PAX9 variants of tooth agenesis was the second mo-lars and the deciduous molars during the deciduous dentition.

Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus(SA),Pseudomonas aeruginosa(PA),and Acinetobacter baumannii(AB)in the bloodstream based on recombinant human mannan-binding lectin protein(M1 protein)-conjugated magnetic bead(M1 bead)enrichment of pathogens combined with RAP. Methods Recombinant plasmids were used to evaluate the assay sensitivity.Common blood influenza bacteria were used for the specific detection.Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR(M-RAP)and quantitative PCR(qPCR)assays.Kappa analysis was used to evaluate the consistency between the two assays. Results The M-RAP method had sensitivity rates of 1,10,and 1 copies/μL for the detection of SA,PA,and AB plasmids,respectively,without cross-reaction to other bacterial species.The M-RAP assay obtained results for<10 CFU/mL pathogens in the blood within 4 h,with higher sensitivity than qPCR.M-RAP and qPCR for SA,PA,and AB yielded Kappa values of 0.839,0.815,and 0.856,respectively(P<0.05). Conclusion An M-RAP assay for SA,PA,and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.

Objective:To assess the effectiveness of a 6-month Ba Duan Jin exercise program in improving the balance of community-dwelling older adults.Methods:A two arms, parallel-group, cluster randomized controlled trial was conducted in 1 028 community residents aged 60-80 years in 40 communities in 5 provinces of China. Participants in the intervention group (20 communities, 523 people) received Ba Duan Jin exercise 5 days/week, 1 hour/day for 6 months, and three times of falls prevention health education, and the control group (20 communities, 505 people) received falls prevention health education same as the intervention group. The Berg balance scale (BBS) score was the leading outcome indicator, and the secondary outcome indicators included the length of time of standing on one foot (with eyes open and closed), standing in a tandem stance (with eyes open and closed), the closed circle test, and the timed up to test.Results:A total of 1 028 participants were included in the final analysis, including 731 women (71.11%) and 297 men (28.89%), and the age was (69.87±5.67) years. After the 3-month intervention, compared with the baseline data, the BBS score of the intervention group was significantly higher than the control group by 3.05 (95% CI: 2.23-3.88) points ( P<0.001). After the 6-month intervention, compared with the baseline data, the BBS score of the intervention group was significantly higher than the control group by 4.70 (95% CI: 4.03-5.37) points ( P<0.001). Ba Duan Jin showed significant improvement ( P<0.05) in all secondary outcomes after 6 months of exercise in the intervention group compared with the control group. Conclusions:This study showed that Ba Duan Jin exercise can improve balance in community-dwelling older adults aged 60-80. The longer the exercise time, the better the improvement.

Objective To investigate the age-related changes of the mandibular third molar root pulp visibility in individuals in East China,and to explore the feasibility of applying this method to deter-mine whether an individual is 18 years or older.Methods A total of 1 280 oral panoramic images were collected from the 15-30 years old East China population,and the mandibular third molar root pulp visibility in all oral panoramic images was evaluated using OLZE 0-3 four-stage method,and the age distribution of the samples at each stage was analyzed using descriptive statistics.Results Stages 0,1,2 and 3 first appeared in 16.88,19.18,21.91 and 25.44 years for males and in 17.47,20.91,22.01 and 26.01 years for females.In all samples,individuals at stages 1 to 3 were over 18 years old.Conclusion It is feasible to determine whether an individual in East China is 18 years or older based on the mandibular third molar root pulp visibility on oral panoramic images.

Objective To investigate the feasibility and value of a multi-parametric MRI radiomics-based nomogram model for pretreatment predicting the lymphovascular space invasion(LVSI)of endometrial endometrioid adenocarcinoma(EEA).Methods Preoperative MRI and baseline clinical characteristics of 205 EEA patients were prospectively collected from Oct 2020 to Jan 2022 in the Obstetrics and Gynecology Hospital,Fudan University,and randomly divided into training set(n=123)and validation set(n=82)in a 6∶4 ratio.The whole-tumor region of interest was manually drawn on T2-weighted imaging,diffusion-weighted imaging(apparent diffusion coefficient),and dynamic contrast-enhanced MRI,respectively,for radiomics features extraction.In the training set,univariate and multivariate Logistic regression analysis were used to select independent clinical predictors of LVSI(+)and construct the clinical model.The least absolute shrinkage and selection operator(LASSO)regression and multivariate Logistic regression analysis were used to select optimal radiomics features to form a radiomics signature.A combined nomogram model was established by integrating clinical independent predictors and the radiomics signature,and validated in the validation set.The predicting performance and clinical net benefit were evaluated by using the area under the receiver operating characteristic curve(AUC)and clinical decision curve analysis,respectively.Results Of the 205 EEA cases,144 cases were LVSI(-)and 61 cases were LVSI(+).Menopausal status,CA125,and CA199 were independent clinical predictors for the LVSI(+),and contributing to a clinical model with AUCs of 0.714(training)and 0.731(validation).From 8 240 extracted radiomics features,five were selected to construct a MRI radiomics signature after de-redundancy and LASSO dimensionality reduction,yielding AUCs of 0.860(training)and 0.759(validation).The combined nomogram model showed AUCs of 0.887(training)and 0.807(validation),outperforming others and achieving maximum clinical benefit in a large range of threshold probability in both training and validation sets.Conclusion The multi-parametric MRI-based nomogram model has the potential for pretreatment predicting the LVSI status of EEA,providing valuable information for clinical management decision-making and improving patient's clinical benefits.