BACKGROUND:Socket-shield technique can effectively maintain labial soft and hard tissues,but the incidence of postoperative complications such as exposure and displacement of root shield is relatively high.It is speculated that the root shield may be exposed and displaced due to excessive load after long-term function of dental implants. OBJECTIVE:Through three-dimensional finite element analysis,we aim to study the influence of varying root shield thicknesses on the stress distribution,equivalent stress peaks,and displacement in the root shield,periodontal ligaments,implant,and surrounding alveolar bone under normal occlusal loading.We also attempt to analyze the correlation between the thickness of the root shield and occurrence of mechanical events such as root shield exposure,displacement,and fracture. METHODS:Cone-beam CT data of a patient who met the indication standard of socket-shield technique for maxillary central incisor were retrieved from database.Reverse engineering techniques were used to build models of the maxillary bone and root shield,while forward engineering was used to create models for the implant components based on their parameters.Models depicting various root shield thicknesses(0.5,1.0,1.5,and 2.0 mm)were created using Solidworks 2022 software.ANSYS Workbench 2021 software was then used to simulate and analyze the effects of varying root shield thicknesses on stress distribution,equivalent stress peaks,and displacement of the root shields,periodontal ligaments,implants,and surrounding alveolar bone under normal occlusion. RESULTS AND CONCLUSION:(1)In all root shield models,the stress was concentrated on the palatal cervical side,both sides of the edges and the lower edge of the labial side.As the thickness of the root shield increased,the equivalent stress peak and displacement showed a decreasing trend.The 0.5 mm thickness model produced a stress concentration of 176.20 MPa,which exceeded the yield strength(150 MPa)of tooth tissue.(2)The periodontal ligament stress in each group was concentrated in the neck margin and upper region.With the increase of root shield thickness,the equivalent stress peak and displacement of periodontal ligament showed a decreasing trend.(3)Implant stress in all models was concentrated in the neck of the implant and the joint of the implant-repair abutment,and the labial side was more concentrated than the palatal side.With the increase of root shield thickness,the equivalent stress peak of the implant in the model showed an increasing trend.(4)In each group of models,stress of cortical bone concentrated around the neck of the implant and the periphery of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the equivalent stress peak around the root shield decreased;the peak value of the equivalent stress of the bone around the neck of the implant showed an increasing trend.In the model,the stress of cancellous bone was mainly concentrated around the neck of the lip of the implant,the top of the thread,the root tip and the lower margin of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the peak value of the equivalent stress of the bone around the root shield in the model showed a decreasing trend.The minimum principal stress of cortical bone in each group of models was concentrated around the neck of the implant,exhibiting a fan-shaped distribution.As the thickness of the root shield increased,the minimum principal stress of cortical bone showed an increasing trend.(5)These results indicate that different thicknesses of the root shield have different biomechanical effects.The root shield with a thickness of 0.5 mm is easy to fracture.For patients with sufficient bone width,the root shield with a thickness of 2.0 mm is an option to reduce the risk of complications such as root shield exposure,fracture,and displacement.Meanwhile,it should be taken into account to protect the periodontal ligament in the preparation process,and rounding treatments ought to be carried out on both sides and the lower edge of the root shield.

Objective:To analyze the learning curve of TiRobot-assisted lumbar pedicle screw fixation (LPSF) by cumulative sum (CUSUM) test method.Methods:The clinical data of 50 patients who underwent TiRobot-assisted LPSF from January 2020 to December 2022 in Beijing Friendship Hospital, Capital Medical University were retrospectively analyzed. CUSUM analysis and learning curve fitting were performed with robot usage time as the main indicator with the time for each step refined (robot registration time, path planning time and guide wire placement time), to select the best learning curve fitting model with the R2 value closest to 1. Using the turning point of the learning curve as the boundary, the learning curve was divided into two stages as learning stage and maturity stage, and then the observation indexes were compared between the two stages. Results:All 50 patients successfully completed the surgery without perioperative complications, with a total of 244 pedicle screws implanted. The total robot usage time and robot registration time showed a gradually decreasing trend with the increase of case number, and the learning curves were successfully fitted and reached their peaks at the seventeenth and thirteenth cases respectively. The entire learning process was divided into learning stage (17 cases) and maturity stage (33 cases) based on the turning point of the learning curve of total robot usage time. The path planning time and guide wire placement time did not show significant changes with the increase in the case number. The total robot usage time, robot registration time and the intraoperative blood loss in the learning stage were significantly higher than those in the maturity stage: (35.35 ± 1.58) min vs. (30.61 ± 0.43) min, (20.83 ± 1.56) min vs. (14.94 ± 0.29) min and 400 (150, 500) ml vs. 200 (110, 300) ml, the guide wire placement time of per screw was significantly lower than that in the maturity stage: 2.00 (1.83, 2.34) min/screw vs. 2.33 (2.13, 2.69) min/screw, and there were statistical differences ( P<0.05 or <0.01). There were no statistical difference in the path planning time, path planning time of per screw, guide wire placement time and the accuracy of screw placement between two stages ( P>0.05). Conclusions:TiRobot-assisted LPSF is a new technology with safety and effectiveness, and it has a relatively short learning curve. To achieve technological maturity, at least 17 surgeries are required with accumulated experience, and the robot registration is the main step of the learning process. After reaching maturity stage, the robot usage time is significantly shortened and intraoperative trauma is significantly reduced while the relatively high screw placement accuracy is ensured.

With the arrival of an aging population,the development of China's elderly care industry is facing numerous problems and challenges.The low-altitude economy is a typical representative of new quality productive forces and has received strong support from the national level.It is expected to improve the quality of life of the elderly,enrich the elderly care service market,and alleviate the pressure of elderly care.Developing the silver economy is a key strategic deployment for the country to actively respond to the aging population issue.It provides various application scenarios,industrial innovation directions,a large number of consumer groups and consumption demands for the low-altitude economy.This article summarizes the current development status of low-altitude economy and silver economy in China,analyzes the necessity of integrated development from the perspectives of market demand,technological progress,and policy support,and explores the development strategies in the fields of elderly care and medical emergency,tourism,and logistics.By exploring the implementation path planning for the integration of the two in real application scenarios,the development advantages and challenges were summarized.The integration of low-altitude economy and silver economy is of great significance for the high-quality development of the elderly care industry and the social economy.However,it still faces challenges such as policies,technology,and social recognition.

Diabetic retinopathy(DR)is a kind of microvascular disease caused by the long-term influence of diabetes mellitus(DM),and it is one of the main cause of global visual impairment and blindness.Its typical characteristics include microaneurysms,hard exudates,macular edema(DME)and neovascularization.Its pathogenesis is diverse,and the root cause is oxidative stress and advanced glycosylation end products.The nuclear red blood cell related factor 2(Nrf2)signa-ling pathway plays an important role in preventing various diseases.As one of the characteristics of DM,hyperglycemia will activate the generation of reactive oxygen species(ROS)in mitochondria.These oxidative stress factors activate the nucle-ar transcription factor κB pathway,becoming the main inducement of various complications of DM.This pathway will in-duce increased transcription of proinflammatory cytokines,including tumor necrosis factor-alpha,transforming growth fac-tor-beta and interleukin-1.The active ingredients of traditional Chinese medicine have significant antioxidant,anti-inflam-matory,anti-apoptotic and angiogenesis-promoting effects,and can block the progression of DR through various mecha-nisms.In this article,the research status of traditional Chinese medicine targeting the Nrf2 signaling pathway in the preven-tion and treatment of DR is reviewed to guide clinical and scientific research.

Objective:To investigate the clinical application effects of the pedicled anterior intercostal artery perforator flap in breast reconstruction after breast-conserving surgery for breast cancer.Methods:This study was a retrospective observational study. From January to December 2023, 16 female breast cancer patients who met the inclusion criteria were hospitalized in the Department of Breast Surgery of the Affiliated Hospital of Southwest Medical University, with the age of (48±8) years. The pedicled anterior intercostal artery perforator flap was used for breast reconstruction of patients after breast-conserving surgery. After complete resection of tumor tissue, a "crescent-shaped" incision was designed at the inframammary fold. The pedicled anterior intercostal artery perforator flap was harvested based on the tumor location and the defect area after tumor removal. The flap was de-epithelialized, coapted, and rotated anterogradely or retrogradely to fill the defect. The donor site wound was closed with layered sutures. The following parameters were recorded: breast tissue loss volume during surgery, surgical duration, retention duration of the drainage tube, positive proportion of tumors in the breast incision margin tissue, breast loss ratio, flap survival, and incidence ratio of complications after operation. Patients were followed up for local recurrence or distant metastasis of tumor. At the last follow-up, the Ueda score was used to evaluate cosmetic outcomes of reconstructed breasts after breast-conserving surgery, and the Breast-Q scale version 2.0 was applied to assess patients' satisfaction and quality of life with breast reconstruction after breast-conserving surgery.Results:The breast tissue loss volume during surgery in this group of patients was 20-128 (59±34) cm3, the surgical duration was 105-200 (143±27) min, the retention duration of the drainage tube was 3-7 (4.6±1.0) d, and the positive proportion of tumors in the breast incision margin tissue was 1/16, with breast loss ratio of 0. After the surgery, the patient's transplanted flaps all survived. One patient had postoperative fat liquefaction in the surgical area, and the incidence ratio of postoperative complications was 1/16. The patients were followed up for 3-12 (11±4) months, and no local breast cancer recurrence or distant metastasis occurred. At the last follow-up, the cosmetic score of breast reconstruction after breast-conserving surgery were excellent in 6 cases, good in 8 cases, and fair in 2 cases, with an excellent and good ratio of 14/16. At the last follow-up, the highest score in the evaluation of patients' satisfaction with breast reconstruction and quality of life after breast-conserving surgery was the satisfaction with the surgeons, with a score of 59-100 (91±13), followed respectively by physiological health of the chest with a score of 60-100 (77±14), psychological health with a score of 35-100 (74±20), breast satisfaction with a score of 55-100 (73±13), satisfaction with information acquisition with a score of 53-100 (70±14), and sexual health with a score of 34-100 (70±23).Conclusions:The pedicled anterior intercostal artery perforator flap is safe and reliable for breast reconstruction after breast-conserving surgery for breast cancer, and can achieve high cosmetic effects and patient satisfaction. This flap is simple in design, easy to operate and highly reproducible, and is worthy of clinical promotion and application.

Objective:To investigate the effects of 10° head up tilt bed rest (HUT) on human cardiac function via 3D speckle tracking echocardiography (3D-STE), and to study the difference in cardiac function under the submaximal exercise load between the horizontal position and 10° HUBR.Methods:Thirty young healthy volunteers were recruited as the subjects, who were randomly divided into an 10° HUT exercise group and horizontal exercise group with 15 subjects in each. Subjects in both groups were asked to ride the bicycle ergometer in the 10° HUBR position and supine position respectively. The load started with 50 W and was increased by 25 W every 3 min until it reached the maximum of 125 W. Before the exercise (resting state), 1 min after the load was increased each time, and 3 min after exercise (recovery period), the following indices were collected: ①basic cardiac function indices: heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP), ②conventional cardiac ultrasound indices: left ventricular ejection fraction (LVEF), stroke volume (SV) and cardiac output (CO), ③left ventricular strain indices: global longitudinal strain (GLS), global circumferential strain (GCS), and global area strain (GAS) measured by 3D-SET. The changes of these indices in the 2 groups of subjects under different exercise loads were observed.Results:The differences in the major effect of the basic heart indices (HR, SBP and DBP), conventional cardiac ultrasound indices (LVEF, SV and CO) and left ventricular strain indices (GLS, GCS and GAS) in response to the exercise load were statistically significant ( F=194.90, 113.66, 17.19, P=0.017, 0.018, 0.001). With the increase of the exercise load, the basic heart indices and conventional cardiac ultrasound indices kept rising, the left ventricular strain indices reached the minimum under a moderate exercise load (75 W), HR, SBP and CO were higher than those of the resting state ( P<0.05 or 0.01). Both LVEF under exercise loads of 75, 100, 125 W and during recovery, and SV under exercise loads of 100, 125 W and during recovery were significantly higher than those of the resting state ( P<0.05 or 0.01), while GLS and GCS under exercise loads of 50, 75, 125 W ( P<0.05 or 0.01), and GAS under exercise loads of 50, 75 W ( P<0.01) were significantly lower. There were statistically significant differences not only in GCS across the groups ( F=4.60, P=0.026) but also in DBP due to the interactions between the grouping and exercise loads ( F=3.13, P=0.031). DBP was higher than that of the resting state when the exercise load was 125 W in both groups. Conclusions:During submaximal exercise, myocardial contractility shows sustained enhancement with the increase of the exercise load. The results of GLS, GCS and GAS indicate that myocardial strain reaches its lowest value under a moderate exercise load, suggesting that moderate exercise can be used to evaluate cardiac function via 3D-SET. Under a simulated lunar gravity of 10° HUT, there is less deformation in the short axis direction of the myocardium, indicating that GCS can be used as a sensitive indicator to detect changes in cardiac function under different gravities.

Background and Aims:Oncoplastic breast-conserving surgery(OBCS)integrates oncologic and plastic surgical techniques and includes two primary approaches:volume displacement and volume replacement.The pedicled lateral thoracic artery perforator(LTAP)flap is a commonly used technique for volume replacement.Although recent studies in China have confirmed its safety in OBCS,its patient-reported outcomes have not been systematically evaluated,and comparative data with volume displacement techniques remain lacking.Therefore,this study was performed to compare the clinical outcomes and patient satisfaction of LTAP flap versus mammoplasty(volume displacement)in OBCS,to inform surgical decision-making.Methods:A retrospective case-control study was conducted,including 106 patients with unilateral stage 0-Ⅲ breast cancer who underwent OBCS at the Affiliated Hospital of Southwest Medical University from January 2023 to June 2024.Patients were divided into the LTAP flap group(27 cases)and the mammoplasty group(79 cases)based on the surgical technique.Intraoperative variables,cosmetic outcomes,postoperative complications,and Breast-Q scores before and after surgery were compared between the two groups.Results:There were no significant differences between the two groups in clinicopathological characteristics or preoperative Breast-Q scores(all P>0.05).The LTAP group had longer operative times,larger excised tissue volumes,and greater postoperative drainage volumes(all P<0.001).Postoperative cosmetic outcomes were significantly better in the LTAP group,with a higher rate of excellent-to-good cosmetic results(88.9%vs.57.3%)and higher Breast-Q scores in breast satisfaction,psychosocial well-being,and physical well-being(all P<0.05).There were no significant differences in complication rates or local recurrence between the two groups(all P>0.05).Conclusion:In OBCS,the LTAP flap demonstrates comparable safety to mammoplasty while achieving superior cosmetic outcomes and patient satisfaction.It is particularly suitable for patients with small breast volumes requiring large tissue excision and holds promise for broader clinical application.

With the arrival of an aging population,the development of China's elderly care industry is facing numerous problems and challenges.The low-altitude economy is a typical representative of new quality productive forces and has received strong support from the national level.It is expected to improve the quality of life of the elderly,enrich the elderly care service market,and alleviate the pressure of elderly care.Developing the silver economy is a key strategic deployment for the country to actively respond to the aging population issue.It provides various application scenarios,industrial innovation directions,a large number of consumer groups and consumption demands for the low-altitude economy.This article summarizes the current development status of low-altitude economy and silver economy in China,analyzes the necessity of integrated development from the perspectives of market demand,technological progress,and policy support,and explores the development strategies in the fields of elderly care and medical emergency,tourism,and logistics.By exploring the implementation path planning for the integration of the two in real application scenarios,the development advantages and challenges were summarized.The integration of low-altitude economy and silver economy is of great significance for the high-quality development of the elderly care industry and the social economy.However,it still faces challenges such as policies,technology,and social recognition.

Objective:To develop a risk prediction model for moderate to severe orthodontic-induced inflammatory root resorption (OIIRR) of maxillary incisors based on cone beam CT (CBCT) radiomics features and clinical characteristics of the orthodontic patients.Methods:Clinical and CBCT data from 101 orthodontic patients treated by the same attending orthodontist in the Department of Orthodontics, Stomatology Hospital of Tianjin Medical University from January 2019 to January 2024 were retrospectively collected. The sample included 42 class Ⅰ patients, 52 class Ⅱ patients and 7 class Ⅲ patients [age: (19.7±6.3) years], and a total of 394 maxillary incisors were analyzed. Potential influencing factors for moderate to severe OIIRR (root volume resorption rate≥10%) were collected from the patients′ CBCT and medical records, including initial age, gender, treatment duration, Angle′s classification, extraction or not, type of orthodontic appliance (fixed or clear aligner), changes in root inclination, root movement distance and direction, pre-treatment cephalometric measurements, pre-treatment root-bone relationship, pre-treatment root length, and pre-treatment radiomics features of the teeth. Univariate analysis was initially performed to screen for factors influencing moderate to severe OIIRR. Subsequently, least absolute shrinkage and selection operator (LASSO) regression, best subset regression, and random forest were used for feature selection to construct the OIIRR risk prediction model. The discrimination, calibration, and net benefit of the three risk prediction models were evaluated, and the optimal model was displayed using a nomogram.Results:LASSO regression identified clinical features including initial age (LASSO coefficient 0.052), treatment duration (LASSO coefficient 0.024), pre-treatment root length (LASSO coefficient -0.023), and vertical root movement distance (LASSO coefficient -0.029). Initial age and treatment duration were positively correlated with the severity of OIIRR, while root length and vertical root movement distance were negatively correlated. A total of 14 radiomics features were identified, including 2 original image features and 12 wavelet features. Best subset regression identified vertical root movement distance as the clinical feature and 7 radiomics features, including 1 original image feature and 6 wavelet features. The random forest model identified 8 wavelet features as important predictors, and all of which were radiomics features. Model performance evaluation showed that the random forest model had the highest discrimination, calibration, and net benefit, making it the optimal model, with radiomics features being the most important predictors.Conclusions:Based on the data from this study, radiomics features were identified as the most important predictors by the optimal model for OIIRR risk prediction. Predicting the occurrence of moderate to severe OIIRR before orthodontic treatment held potential clinical application value.

Background and Aims:Oncoplastic breast-conserving surgery(OBCS)integrates oncologic and plastic surgical techniques and includes two primary approaches:volume displacement and volume replacement.The pedicled lateral thoracic artery perforator(LTAP)flap is a commonly used technique for volume replacement.Although recent studies in China have confirmed its safety in OBCS,its patient-reported outcomes have not been systematically evaluated,and comparative data with volume displacement techniques remain lacking.Therefore,this study was performed to compare the clinical outcomes and patient satisfaction of LTAP flap versus mammoplasty(volume displacement)in OBCS,to inform surgical decision-making.Methods:A retrospective case-control study was conducted,including 106 patients with unilateral stage 0-Ⅲ breast cancer who underwent OBCS at the Affiliated Hospital of Southwest Medical University from January 2023 to June 2024.Patients were divided into the LTAP flap group(27 cases)and the mammoplasty group(79 cases)based on the surgical technique.Intraoperative variables,cosmetic outcomes,postoperative complications,and Breast-Q scores before and after surgery were compared between the two groups.Results:There were no significant differences between the two groups in clinicopathological characteristics or preoperative Breast-Q scores(all P>0.05).The LTAP group had longer operative times,larger excised tissue volumes,and greater postoperative drainage volumes(all P<0.001).Postoperative cosmetic outcomes were significantly better in the LTAP group,with a higher rate of excellent-to-good cosmetic results(88.9%vs.57.3%)and higher Breast-Q scores in breast satisfaction,psychosocial well-being,and physical well-being(all P<0.05).There were no significant differences in complication rates or local recurrence between the two groups(all P>0.05).Conclusion:In OBCS,the LTAP flap demonstrates comparable safety to mammoplasty while achieving superior cosmetic outcomes and patient satisfaction.It is particularly suitable for patients with small breast volumes requiring large tissue excision and holds promise for broader clinical application.