Background The decline of physical activity in the elderly due to aging may increase the risk of sarcopenia. Currently, there is a lack of evidence from large natural populations on the relationship between PA and sarcopenia. Objective To explore the relationship between PA and sarcopenia in the elderly aged 60 years and above in 10 provinces (autonomous regions) of China. Methods Data were retrieved from the 2022—2023 round of the China Development and Nutrition Health Impact Cohort. Personal basic information and PA data were collected by questionnaire survey. Skeletal muscle mass was measured by bio-electrical impedance analysis, muscle strength was measured using a grip dynamometer, and physical performance was reflected by 6-meter walk speed. The Asian Working Group for Sarcopenia (AWGS) 2019 criteria were used to diagnose sarcopenia. Light physical activity (LPA) duration, moderate-to-vigorous physical activity (MVPA) duration, and total physical activity volume were calculated. A total of 3326 residents aged ≥60 years with complete data were selected as the survey participants. Multiple logistic regression models and restricted cubic splines (RCS) were used to assess the association between PA duration/volume and sarcopenia. Results In 10 provinces (autonomous regions) of China, the prevalence of sarcopenia in the elderly aged 60 years and above was 5.5% (95%CI: 4.7%, 6.2%). The logistic regression analysis showed that compared with the elderly reporting 0-7.0 h·week⁻¹ in LPA duration, the risk of sarcopenia in the elderly with LPA duration of >14.0-21.0 h·week⁻¹ was reduced by 51% (OR=0.49, 95%CI: 0.26, 0.96). Compared with the elderly with total physical activity ≥15.0 metabolic equivalent of task (MET)-h·week⁻¹, those with <7.5 MET-h·week⁻¹ had a 2.24-fold increased risk of sarcopenia (OR=2.24, 95%CI: 1.17, 4.29). The RCS results found that LPA duration and total physical activity volume each showed a nonlinear dose-response relationship with the risk of sarcopenia (P_overall<0.05, P_non-linear<0.05). Compared with the elderly with an LPA duration of 0 h· week⁻¹, the risk of sarcopenia in the elderly with an LPA duration of 12.6 h· week⁻¹ was the lowest (OR=0.42, 95%CI: 0.21, 0.83). Compared with the elderly with a total physical activity volume of 15.0 MET-h· week⁻¹, the elderly with a total physical activity volume of 46.0 MET-h· week⁻¹ had the lowest risk of sarcopenia (OR=0.57, 95%CI: 0.38, 0.84). There was no statistically significant association between weekly MVPA duration and the risk of sarcopenia (P>0.05). Conclusion Increasing weekly LPA duration and total physical activity volume would help to reduce the risk of sarcopenia.

An ideal dermal filler should integrate filling, repair, and anti-aging effects, with immediate tissue augmentation, slow degradation, and progressive stimulation of collagen regeneration. However, commonly used hyaluronic acid (HA) hydrogels, while effective for rapid filling, suffer from limited duration of support, weak cell adhesion, and an inability to promote collagen regeneration. Silk fibroin (SF), a natural protein from silkworm cocoons, is known for its excellent cell adhesion and collagen-stimulating abilities. However, its limited gelation capability restricts its potential application as a standalone injectable hydrogel. Based on a complementary strategy, this study combines the rapid gelling properties of HA with the collagen regenerative properties of SF to create a co-crosslinked HA-SF hydrogel. The composite hydrogel merges HA's rapid filling effect with SF's strong tissue adhesion and collagen-stimulating abilities. The formulation, physicochemical properties, degradation, biocompatibility, and filling effects of the HA-SF hydrogel were systematically investigated. HA-SF hydrogel exhibits excellent mechanical properties and ensures long-term support while maintaining injectability. Interestingly, after intradermal injection in the UVB-induced photoaging model, HA-SF hydrogel not only enhances hydrogel-cell interaction but also continues to stimulate collagen regeneration, especially type III collagen. This dual action achieves the biological effects of repair and anti-aging while maintaining the filling effect. Proteomic analysis confirms that repair and anti-aging effects are enhanced by the regulation of skin fibroblasts and modulation of amino acid and lipid metabolism. This composite hydrogel holds strong promise for clinical applications, offering a safer, long-lasting, and more natural injectable filler that combines filling, repair, and anti-aging into one system.

Objective:To evaluate the effect of polyetheretherketone (PEEK) periodontal splints and splints made from other materials under static loading on stress distributions in periodontal tissues, cement layer, and splints themselves.Methods:A finite element model based on cone-beam CT imaging data of a 25-year-old male patient (treated at the Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University in October 2021 for a cracked maxillary molar) with a healthy and intact mandibular dentition and periodontal health was constructed. The finite element model included anterior mandible dentition, mandibular bone model without bone resorption (WBR group), a periodontally compromised mandible model (control group), and three types of periodontal splints: a PEEK periodontal splint (0.7 mm thick, Young′s modulus: 4.1 MPa), a fiber-reinforced resin (FRC) splint (1.0 mm thick, Young′s modulus: 37.0 MPa), and a titanium splint (1.2 mm thick, Young′s modulus: 110.0 MPa). The bone resorption models fixed with different periodontal splints constituted the experimental groups (PEEK group, FRC group and titanium group). Loading of 100 N was applied on the midpoint of the incisal edge of tooth 41. The direction was set at 0°, which was parallel to the long axis of the tooth and downward. The buccal to lingual and downward angles were 30°and 60°, respectively, perpendicular to the long axis of the tooth and 90° to the lingual side. The finite element analysis software was utilized to analyze the stress distribution characteristics of the periodontal tissues, adhesive layer, and the splint itself in the anterior mandibular teeth among the different group.Results:Under the different loading simulation, in the control group, the maximal von Mises stresses of periodontal ligament and bone were 15.7-50.2 MPa and 38.8-130.3 MPa, respectively, and in the WBR group, the maximal von Mises stresses of periodontal ligament and bone were 3.6-6.4 MPa and 16.5-42.7 MPa, respectively. Under the same loading conditions, the magnitude of maximal von Mises stresses in periodontal tissues in the PEEK group was 4.6-6.2 MPa, and the magnitude of stresses in the periodontal ligament of 41 teeth in the WBR group was similar to that in the PEEK group, but higher than that in the FRC and titanium groups. The maximal von Mises stresses of each group is primarily distributed in the periodontal ligament and alveolar bone at the cervical area of the tooth. The higher the elastic modulus of the splint, the higher its own maximal von Mises stresses, and the smaller the maximal principal stresses transmitted to the adhesive layer. In the PEEK group and titanium group, the stress distribution area in the adhesive layer and the splint was near the splint connection adjacent to tooth 41.Conclusions:Periodontal splints fabricated from three types of materials, are effective in distributing stress within the periodontal tissues of the abutment teeth. Compared to FRC and titanium group, the higher PEEK splint stress value was obtained, and the smaller the stress value was transmitted to its adhesive layer.

Objective:To assess the impact of reducing the mesh density on the overall volume and trueness of single-crown restora-tions.Methods:15 single-crown restorations were included,and their mesh density in 3D software was simplified by 75％,50％,25％,10％and 5％respectively.The overal volume,file size and mesh edge length of the restorations with different reduction levels were compared.Deviation analysis was conducted by curving clipping the area of the shoulder,tissue surface(except for the shoulder)and occlusal surface of the restorations and compared with those of the corresponding regions in the non-simplified restorations.Trueness was assessed using the root mean square(RMS)values for the volume and trueness of different areas.Results:Reducing the mesh den-sity did not significantly affect the overal volume of the single-crown restorations(P＞0.05),but it had a significant impact on the file size(P＜0.001),mesh edge length(P＜0.001)and the trueness of the shoulder(P＜0.001),tissue surface(except for the shoulder)(P＜0.001)and occlusal surface(P＜0.001)areas.Conclusion:Reducing the mesh density had little impact on the overall volume of the restorations but significantly affected their trueness.

The use of robots to augment human capabilities and assist in work has long been an aspiration.Robotics has been developing since the 1960s when the first industrial robot was introduced.As technology has advanced,robotic-assisted surgery has shown numerous advantages,including more precision,efficiency,minimal invasiveness,and safety than is possible with conventional techniques,which are research hotspots and cutting-edge trends.This article reviewed the history of medical robot development and seminal research papers about current research progress.Taking the autonomous dental implant robotic system as an example,the advantages and prospects of medical robotic systems would be discussed which would provide a reference for future research.

AIM:To investigate the effects of sodium selenite(SS)on viability,migration and angiogenesis of human non-small-cell lung cancer(NSCLC)H520 and A549 cells.METHODS:The H520 cells,A549 cells,and hu-man umbilical vein endothelial cells(HUVEC)were divided into control group(0 μmol/L SS),low dose group(5 μmol/L SS),middle dose group(10 μmol/L SS),and high dose group(20 μmol/L SS).Cell viability was assessed using the CCK-8 assay,and the half-maximal inhibitory concentration(IC50)was calculated.Cell migration and invasion abilities were determined through wound healing and Transwell assays.The regulatory effects of SS on angiogenesis,vasculogenic mimicry and"mosaic"vascular formation between HUVEC and NSCLC cells were detected using vessel forming assays.The expression of vascular endothelial growth factor(VEGF)in the supernatant of lung cancer cells in each group was de-tected using chemiluminescence.RT-qPCR was used to assess the mRNA expression of VEGF,vascular endothelial growth factor receptor 2(VEGFR2)and angiotensin II(Ang II).Western blot was used to examine the protein levels of VEGF,p-PI3K,and p-Akt in H520 and A549 cells.RESULTS:The IC50 values of SS to HUVEC,A549 cells and H520 cells for 48 h were 6.762,9.003 and 7.356 μmol/L,respectively.Compared with control group,the wound healing rate was significantly decreased in each group treated with SS for 48 h(P<0.01).In HUVEC,the number of migrating cells in middle dose and high dose groups decreased(P<0.01),whereas in lung cancer cells,the number of migrating cells in each group decreased after SS treatment(P<0.01).The mRNA expression levels of VEGF,VEGFR2 and Ang II were lower in high-dose SS group than those in control group(P<0.05 or P<0.01).In H520 cells,compared with control group,the protein levels of VEGF,p-PI3K and p-Akt in SS treatment groups were significantly decreased(P<0.05 or P<0.01).CONCLUSION:Sodium selenite inhibits the viability and migration of HUVEC,H520 cells and A549 cells,and inhibits the formation of vasculogenic mimicry and mosaic vessels in NSCLC cells.This mechanism may be related to the inhibition of PI3K-Akt signaling pathway activation and regulation of VEGF.

Objective:To estimate tissue/organ doses and effective dose to operators in the overexposure incident during an interventional procedure using Monte Carlo method.Methods:The phantoms were constructed for both the operators and the patient based on the adult mesh-type reference computational phantoms (MRCPs) recommended by the International Commission on Radiological Protection (ICRP) Publication 145 and phantom deformation technology. Models of exposure scenario were constructed based on the on-site equipment and the irradiation conditions. The Monte Carlod simulation method was used to evaluate the absorbed dose to critical tissues and organs, such as the operator′s eye lens and thyroid, as well as the effective dose.Results:In the particular exposure conditions, the maximum absorbed doses in the primary organs of the two operators were in the left eye lens, with doses of 1.216 and 0.223 mGy, respectively. The thyroid absorbed doses were 0.074 and 0.019 mGy, while the effective doses to the two operators were 0.088 and 0.021 mSv, respectively. The reduction rates of effective dose for the two operators when wearing lead aprons and lead thyroid collars were 67.16% and 78.79%, respectively.Conclusions:The combination of Monte Carlo method and MRCPs can be used to restore a specific irradiation scenario to a high degree and to estimate the physical dose of to the irradiated persons.

Objective : The polishing effects of different compositions of chairside polishing systems on polyetheretherketone (PEEK) were compared to provide a reference for the rational selection of polishing systems for this material in clinical settings. Methods : A total of 108 specimens were made from ShushijieTMPEEK crown and bridge materials, Bio-PAEK® dental PEEK, and BioHPP® PEEK. Thirty-six specimens of each material were randomly divided into 6 groups on average based on their polishing technique: OptiDisc®, Super-Snap® Rainbow Technique Kit, VITA ENAMIC®Clinical Polishing Set, Sof-LexTM Diamond Polishing System, Visio.lign Finishing Kit for Composite Veneers, and CERAMAGE Polishing Kit, LavaTM Ultimate ceramic and VITA ENAMIC ceramics were set as the control groups, and 6 specimens were made in each material, polished by Sof-LexTM Diamond Polishing System and VITA ENAMIC® Polishing Set clinical, respectively, according to the manufacturers’ suggestions. The surface roughness (Ra value and Sa value) and gloss of each set were measured. The surface morphologies of the polished specimens were observed by scanning electron microscopy. Results : Surface roughness (Ra value and Sa value) and gloss were mainly influenced by the type of polishing system, and they varied between PEEK material types. The Sof-LexTM Diamond Polishing System produced the highest surface roughness and the lowest gloss values for PEEK materials, while the Super-Snap® Rainbow Technique Kit, Visio.lign Finishing Kit for Composite Veneers and CERAMAGE Polishing Kit resulted in low surface roughness values. The Visio.lign Finishing Kit for Composite Veneers and CERAMAGE Polishing Kit exhibited high gloss values. Polishing paste particles were observed embedded on the surfaces of the PEEK materials polished by the Visio.lign Finishing Kit for Composite Veneers; the surfaces of specimens polished by the CERAMAGE Polishing Kit were smooth, without polishing paste particle residue. Using the same polishing system, the best polishing results were obtained with BioHPP® among the PEEK materials tested. The surface roughness values of the three tested PEEK materials polished by the CERAMAGE Polishing Kit were similar to those of the LavaTM Ultimate ceramic and VITA ENAMIC ceramic, but the gloss was higher than that of both. Conclusion CERAMAGE Polishing Kit was recommended for polishing all three tested PEEK materials, achieving a good polishing effect, with similar surface roughness and higher gloss characteristics comparable to those of polished computer-aided design and manufacturing (CAD/CAM) resin-matrix ceramics.

Objective: To observe the effects of electroacupuncture (EA) at Neiguan (PC6) on arrhythmia during acute myocardial ischemia-reperfusion and the expression of connexin 43 (Cx43) in rats. Methods: A total of 40 Sprague-Dawley male rats were used. Ten rats were randomly selected as the blank group, and the remaining 30 rats were randomly divided into a model group and an EA group, with 15 rats in each group. Before modeling, rats in the EA group received one session of EA intervention at bilateral Neiguan (PC6) for 30 min; the other groups were treated with the same grasping and anesthesia for 30 min without intervention. PowerLab physiological recorder was used to record electrocardiograph within 30 min of infarction. After the experiment, cardiac tissue and serum were collected from rats. Hematoxylin-eosin (HE) staining was used to observe the morphological changes of myocardial tissue in the ventricular infarction area of rats in each group. The expression of Cx43 protein in the myocardium of each group was detected by Western blotting (WB). Enzyme-linked immunosorbent assay (ELISA) was used to determine the activity of Na+-K+-ATPase in myocardial tissue and the serum content of endogenous digitalis-like factor (EDLF) in rats. Results: There was no statistical difference in arrhythmia score between the EA group and the model group, but the total duration and average duration of arrhythmia in the EA group were decreased (P<0.01). HE staining showed that compared with the blank group, myocardial cells in the model group were disorganized and seriously damaged. The pathological changes in the EA group were similar to those in the model group, but the damage was relatively minor. The results of WB showed that compared with the blank group, the Cx43 expression in myocardial tissue of the model group was decreased (P<0.01); compared with the model group, the Cx43 expression in the EA group was increased (P<0.01); compared with the blank group, the Na+-K+-ATPase activity in myocardial tissue of the model group was significantly decreased (P<0.01); compared with the model group, the Na+-K+-ATPase activity in the EA group was increased (P<0.01). ELISA results showed that compared with the blank group, the serum EDLF content in the model group was significantly increased (P<0.01); compared with the model group, the EDLF content in the EA group was decreased (P<0.01). Conclusion: EA at Neiguan (PC6) can delay and reduce the onset of arrhythmia during myocardial infarction in the rat model of myocardial ischemia-reperfusion. Its mechanism of action may be related to the regulation of the Cx43 expression in myocardial tissue, improvement of the activity of Na+-K+-ATPase in myocardial tissue, and increase in the content of serum EDLF.

Minimal residual disease (MRD) is termed as the small numbers of remnant tumor cells in a subset of patients with tumors. Liquid biopsy is increasingly used for the detection of MRD, illustrating the potential of MRD detection to provide more accurate management for cancer patients. As new techniques and algorithms have enhanced the performance of MRD detection, the approach is becoming more widely and routinely used to predict the prognosis and monitor the relapse of cancer patients. In fact, MRD detection has been shown to achieve better performance than imaging methods. On this basis, rigorous investigation of MRD detection as an integral method for guiding clinical treatment has made important advances. This review summarizes the development of MRD biomarkers, techniques, and strategies for the detection of cancer, and emphasizes the application of MRD detection in solid tumors, particularly for the guidance of clinical treatment.