BACKGROUND:The healing of mandibular fractures after rigid internal fixation is influenced by many factors,including the material of the bone plate,fracture site,and bone density of the patient.However,there are relatively few studies on the relationship between the stability of mandibular fracture fixation in different bone qualities and they lack a scientific basis. OBJECTIVE:To analyze the stability of fixation of mandibular fractures with different bone qualities with bioabsorbable plates and miniature titanium plates by finite element analysis. METHODS:Three-dimensional finite element models of class Ⅰ-Ⅳ mandibular fractures were developed according to the bone quality classification method proposed by ZARB and LEKHOLM.The fractures at the median mandibular symphysis,mandibular body,and mandibular angle were simulated under different bone qualities.Bioabsorbable bone grafting plates(or miniature titanium plates)were placed at each fracture site for fixation and to simulate the state of healthy side occlusion.Finite element analysis on the model was used to analyze the relative displacement of the fracture segments and the stress distribution of fixators. RESULTS AND CONCLUSION:(1)The maximum stress value during fixation with titanium plates increased gradually with the increase of bone class,in which the maximum stress value of titanium plates was the highest in the mandibular body class Ⅳ bone group,which was 382.74 MPa and 96.11 MPa in the miniature titanium plate and bioabsorbable plate groups.The results for mandibles of the same bone type showed that the maximum stress value of titanium plates was much higher than that of bioabsorbable plates.(2)For fractures of the median middle of the mandible in types Ⅲ and Ⅳ,the displacement of the fracture breaks at the fixation site was large and exceeded the limiting value of bone healing(>150 μm),regardless of whether the fixation was performed with a miniature titanium plate or a bioabsorbable plate.For type Ⅳ mandibular fractures,the fracture end displacement in the bioabsorbable plate group exceeded the healing limit value,and the fracture end displacement in the miniature titanium plate group was close to the healing limit value.Under the same bone quality and fracture site,the fracture displacement of the miniature titanium plate group was smaller than that of the bioabsorbable plate group.(3)The results showed that the strength and stiffness of the two internal fixations were sufficient to support bone healing of fractures at three sites of the types Ⅰ-Ⅳ mandible,and the fixation stability of the bioabsorbable plate was almost the same as that of the miniature titanium plate,which could provide early healing conditions for fractures.Mandibular bone type should be taken into consideration in the treatment of mandibular fracture.The higher the mandibular bone grade,the worse the stability of fracture fixation,and the more likely the complications such as poor bone healing will occur after surgery.

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.

Shared Decision-Making （SDM） is a crucial concept in modern medicine， emphasizing the joint participation of doctors and patients in the medical decision-making process. However， the authoritative position of doctors and the passive role of patients in traditional medical models often overlook the personal wishes and needs of patients， leading to tense doctor-patient relationships and medical disputes. By listening to and understanding their stories， narrative medicine helps doctors gain a more comprehensive understanding of patients’ situations and balances medical advice with patient needs in the decision-making process. Through systematic literature analysis and theoretical exploration， this paper investigated the application effects and mechanisms of narrative medicine in different medical contexts， as well as analyzed its specific role in the process of SDM. The aim is to explore the value of narrative medicine in bridging differences in SDM， revealing its role in promoting doctor-patient communication， enhancing decision-making participation， and improving medical outcomes. Researches had found that narrative medicine enhanced doctors’ “narrative ability”， promoted emotional communication and trust between doctors and patients， reduced conflicts and misunderstandings in decision-making， and improved patients’ sense of participation and trust， thus playing an important role in SDM. Therefore， by enhancing doctor-patient communication and understanding， promoting SDM and treatment selection between doctors and patients， personalized care and treatment optimization， advocating for doctor-patient co-construction， improving consultation efficiency， restoring the patient’s subject position， and other methods， it can bridge doctor-patient differences， promote communication and enhance decision-making participation， and improve medical outcomes and patient satisfaction.

Autoimmune hepatitis （AIH） is an inflammatory disease caused by immune dysfunction， and its pathogenic mechanism remains unclear. In recent years， a large number of studies have shown that iron homeostasis imbalance and ferroptosis are closely associated with the pathogenesis and progression of AIH. This article reviews the pathological mechanism and impact of iron overload and ferroptosis in AIH， in order to provide new insights and theoretical bases for research on the mechanism and clinical treatment of AIH.

BACKGROUND:Bone tissue remodeling is closely related to stress loading.Currently,there are few studies or guidelines on the relationship between bone and occlusal adjustment of implant prostheses and there is also a lack of scientific evidence. OBJECTIVE:To investigate the effects of different implant occlusal gaps on stress distribution,stress peak and displacement at the implant-bone interface under Ⅰ-Ⅳ bone conditions by a finite element method. METHODS:After scanning the equal-scale tooth model with an optical scanner,equal-scale models of the upper right first molar Straumann 4.8×8 mm BL RC implant and its related components was constructed using Solidworks 2022.Then,using Mimics,Geomagic,and Solidworks software,the maxillary and mandibular bone models of class Ⅰ-Ⅳ bones were established based on the bone classification proposed by ZARB and LEKHOLM in the literature,and the NORTON and TRISI bone density classification method.The models were assembled with the occlusal gaps of 0,20,40,60,80,and 100 μm for the restorations,and an additional set of homogeneous models without density ratio settings was constructed for comparison.After the above models were imported into Hypermesh for meshing,the material assignment,boundary constraints and parameter setting were performed for the finite element analysis.Finally,250 N was used as the loading force to simulate the maxillary and mandibular stress conditions.Stress distribution,peak stress and displacement of the implant-bone interface in each group of models were analyzed and compared. RESULTS AND CONCLUSION:Under the same loading conditions,the stresses in the implant restorations were evenly distributed with the occlusal contact points.When the occlusal gap reached 80 and 100 μm,stress interruptions occurred in the implant crowns under class Ⅰ bone and class Ⅱ,Ⅲ and Ⅳ bones,respectively.The displacement of the implant-bone interface was mainly concentrated in the cortical bone region around the implant and transmitted down the long axis of the implant to the cancellous bone region at the bottom.With the changes of class Ⅰ-Ⅳ jaw bones,the displacement and Von Mises stress in the cortical bone region increased in all groups,and were greater than those in the cancellous bone region.The Von Mises stress in the cancellous bone region was similar to that in the cortical bone region except that it showed a downward trend from class Ⅱ bone.However,when the occlusal gap increased,the stress and displacement peak values in the cortical bone and the cancellous bone showed a decreasing trend.The stress of the implant-bone interface was between 20 MPa and 60 MPa when the occlusal gap was 0-40 μm for class Ⅱ-Ⅳ bones and 60 μm for class Ⅳ bone,and the stress of the other groups was less than 20 MPa.The Von Mises stress was mainly concentrated in the neck of the implant,and the peak value of von Mises stress in class Ⅱ-Ⅳ bones with the occlusal gap of 20 μm was higher than that(144.10 MPa)in class Ⅰ bone with the occlusal gap of 0 μm.In the homogeneous model with different elastic moduli,the distribution of stress and displacement was more uniform than that in the heterogeneous model and the occlusal space should increase with the decrease of jaw bone density in clinical practice.To conclude,from the perspective of biomechanics,the alveolar bone should be taken into account in the occlusal adjustment of implant denture.An occlusal gap of 20-40 μm between a single dental implant and a natural tooth in the opposite jaw is a relatively suitable solution for occlusal adjustment under different bone conditions.However,due to the particularity of finite element analysis method,it needs to be further studied in combination with clinical practice.

BACKGROUND:Most of the formulas for the clinical treatment of premature ovarian insufficiency have evolved from the basic formula of Liuwei Dihuang Pills,and have achieved good therapeutic efficacy.Currently,most of the experimental studies on Liuwei Dihuang Pills focus on morphological observations and physiological and biochemical detection of in vivo animal models,while fewer studies on molecular mechanisms have been reported. OBJECTIVE:To explore the molecular mechanism of Liuwei Dihuang Pills in the treatment of premature ovarian insufficiency based on the receptor gamma coactivator-1 alpha/mitochondrial transcription factor A/reactive oxygen species pathway. METHODS:Premature ovarian insufficiency model was established in mice by intraperitoneal injection of cyclophosphamide 120 mg/kg combined with busulfan 12 mg/kg,and then Liuwei Dihuang Pill suspension was used to intervene in premature ovarian insufficiency mice.After 12 weeks of intervention,the levels of follicle-stimulating hormone,luteinizing hormone,estradiol,anti-Mullerian hormone,8-hydroxydeoxyguanosine,total antioxidant capacity and reactive oxygen species in serum of mice were detected by ELISA method.The morphological changes in mouse ovaries were observed by hematoxylin-eosin staining.The ultrastructure of mouse follicular granulosa cells and the apoptosis of granulosa cell mitochondria were observed by transmission electron microscopy.The expression levels of receptor gamma coactivator-1 alpha and mitochondrial transcription factor A in mouse ovarian granulosa cells were detected by immunohistochemistry. RESULTS AND CONCLUSION:Compared with the model group,serum levels of follicle-stimulating hormone,luteinizing hormone,reactive oxygen species,and 8-hydroxydeoxyguanosine were decreased in the experimental group(P＜0.05),and the levels of estradiol,anti-Mullerian hormone,and total antioxidant capacity were increased(P＜0.05).Hematoxylin-eosin staining showed that in the model group,there were more atretic follicles and corpus luteum forms,some secondary follicles,and interstitial fibrosis and hyperplasia;in the experimental group,a large number of atretic follicles,few corpus luteum forms,primordial follicles were observed at the edges but there were few secondary follicles and no mature follicles.Transmission electron microscopy showed that the organelles in ovarian granulosa cells of mice in the experimental groups were relatively intact.Immunohistochemical results showed that compared with the model group,the expression level of receptor gamma coactivator-1 alpha in the ovarian tissue of mice increased slightly in the experimental group at the 4th week,and there was no significant change at the 8th and 12th weeks.The expression level of mitochondrial transcription factor A in the ovarian tissues of mice in the experimental group was transiently increased at the 4th week,and then slightly decreased,which were all significantly different from those of the model group.To conclude,Liuwei Dihuang Pills inhibit ovarian granulosa cell apoptosis in mice with premature ovarian insufficiency to a certain extent through the receptor gamma coactivator-1 alpha/mitochondrial transcription factor A/reactive oxygen species signaling pathway,thereby improving the endocrine function of the ovary,enhancing the antioxidant capacity,and attenuating the degree of oxidative stress damage.

Objective : To investigate the prevalence of occupational injury and identify its influencing factors among workers in a steel enterprise in Gansu Province, so as to provide insights into prevention of occupational injury among steel workers. Methods: Workers were sampled from a steel enterprise in Gansu Province using a cluster sampling method from January to March 2022, and participants' demographics, occupational history and occupational injury were collected using questionnaire surveys. The type of job and site and type of injury were analyzed among workers with occupational injuries, and factors affecting workers' occupational injuries were identified using a multivariable logistic regression model. Results: A total of 12 089 questionnaires were allocated and 10 725 valid questionnaires were recovered, with an effective recovery rate of 88.71%. The respondents included 9 412 males (87.77%) and 1 312 females (12.23%), and had a median age of 36.00 (interquartile range, 15.00) years. Junior college and above was the predominant educational level (6 056 workers, 56.47%), and the respondents had a median length of service of 10 (interquartile range, 11) years. The prevalence of occupational injury was 5.25% among respondents. Overhaul worker was the main type of job (11.90%), and object strike was the predominant type of occupational injury (18.25%), while the lower limb was the predominant site of injury (27.82%). Multivariable logistic regression analysis identified men (OR=2.464, 95%CI: 1.580-3.843), age (30 to 39 years, OR=2.561, 95%CI: 1.643-3.993; 40 to 49 years, OR=5.197, 95%CI: 2.679-10.079; 50 years and older, OR=10.620, 95%CI: 6.788-16.615), exposure to high temperature (OR=1.400, 95%CI: 1.165-1.683), operating equipment failure (OR=1.291, 95%CI: 1.048-1.591), absence of personal safety protection equipment (OR=1.555, 95%CI: 1.064-2.273) and safety behavior scores (OR=0.967, 95%CI: 0.937-0.996) as factors affecting occupational injuries among workers in a steel enterprise. Conclusions Men and overhaul workers are at a high risk of occupational injuries in this steel enterprise. Objectstrike is the predominant type of injury and lower limb is the main site of injury. The risk of occupational injuries is affected by gender, age, working environments, equipment status and safety behaviors.

Objective To develop and validate a deep learning model for automatic identification of liver CT contrast-enhanced phases.Methods A total of 766 patients with liver CT contrast-enhanced images were retrospectively collected.A three-phase classification model and an arterial phase(AP)classification model were developed,so as to automatically identify liver CT contrast-enhanced phases as early arterial phase(EAP)or late arterial phase(LAP),portal venous phase(PVP),and equilibrium phase(EP).In addition,221 patients with liver CT contrast-enhanced images in 5 different hospitals were used for external validation.The annotation results of radiologists were used as a reference standard to evaluate the model performances.Results In the external validation datasets,the accuracy in identifying each enhanced phase reached to 90.50%-99.70%.Conclusion The automatic identification model of liver CT contrast-enhanced phases based on residual network may provide an efficient,objective,and unified image quality control tool.

【Objective】 To review the scientific research advances in the field of preschool children′s nutrition from 2012 to 2022, in order to provide reference for relevant policy formulation and further scientific exploration in this area. 【Methods】 High-quality literature published both domestically and internationally between 2012 and 2022 was retrieved through Web of Science (WOS) and China National Knowledge Infrastructure (CNKI) database. Excel and CiteSpace software were applied to visualize the research hotspots and frontier trends. 【Results】 A total of 1 816 English articles and 110 Chinese articles were included in the analysis. The cooperation network density of research institutions and authors was found to be low. Excluding the search terms, the top three English keywords were vitamin A (0.74), intervention (0.67), obesity prevention (0.55); the top three Chinese keywords were "anemia" (0.41), "obesity" (0.38), and "nutritional status" (0.18). In Chinese and English clusters, "anemia" and "physical activity" ranked first, respectively. The latest burst words identified were "dietary pattern" and "diet quality". 【Conclusions】 The number of English literature published in the field of preschool children′s nutrition is increasing, but it has shown a downward trend in the past three years in China. There are few studies in this field in China. The research hotspots primarily focus on the nutritional status of preschool children, with less attention paid to intervention research and methodological exploration. Further research in the field of preschool children′s nutrition in China may need to focus on the external determinants of preschool children′s nutrition, such as parental education, diet and food supply.

The seventy-two grid palm technique is an important theoretical source of traditional Chinese medicine hand diagnosis. Starting from the ecological medical model， we analyse the seventy-two grid palm technique， and believe that its diagnosis of human body integrates biological， ecological， psychological， social and other factors， and each factor is based on physiological and pathological theories， and its external social interpretation of the nature of the human body is inseparable from health state. It is proposed that the seventy-two grid palm technique should be integrated with the ecological and natural viewpoints based on the biomedical models or bio-psycho-social medical models， and the research should be conducted from the perspective of the ecological medical model， in order to promote the development of hand diagnosis.