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.

Background Maternal atmospheric pollution during pregnancy may alter fetal intrauterine development programming, thereby increasing the risk of childhood obesity in the future. Objective To investigate the effects of atmospheric pollution exposure during pregnancy on the incidence of childhood obesity in offspring. Methods English databases (PubMed, Web of Science, and Medline) and Chinese databases (Wanfang Data Knowledge Service Platform, China National Knowledge Infrastructure, and VIP Information Chinese Journal Service Platform) were searched for literature reporting exposure to atmospheric pollution during pregnancy and childhood obesity published from 1 January 2000 to 31 August 2023. The quality of the included literature was evaluated using the quality assessment tools for observational cohort and cross-sectional studies recommended by the US National Institutes of Health. Results Twenty-four studies meeting the inclusion criteria were identified and the associated atmospheric pollutants included particulate matter, ozone, nitrogen oxide, carbon oxide, and sulfur oxide. In comparison to the non-exposed group, prenatal exposure to various common atmospheric pollutants were significantly associated with an elevated risk of childhood obesity in offspring. Conclusion Maternal exposure to atmospheric pollution during pregnancy is associated with an elevated risk of childhood obesity in subsequent years. Future studies should pay more attention to the effects of atmospheric pollution on the distribution of children's body fat and metabolic development, and further identify potential mechanisms of atmospheric pollutant exposure leading to childhood obesity.

Objective:To investigate the effect of different acquisition duration of brain image of 18F-florbetaben(18F-FBB)positron emission tomography(PET)on standardized uptake value(SUV).Methods:Eight subjects who underwent 18F-FBB PET examination in Chinese PLA General Hospital from May 2021 to June 2021 were selected,including 5 persons of healthy control and 3 patients with mild cognitive impairment(MCI).All subjects underwent 18F-FBB PET imaging,and the dynamic PET images of them on brains were continuously acquired for 20 min between 90 and 110 min after the 18F-FBB injection was injected as(3.7-5.5 MBq/kg).Under the situation that other reconstruction parameters did not change,the images were reconstructed at 0-1,0-3,0-5,0-10,0-15 and 0-20 min,respectively.The same of region of interest(ROI)ranges were delineated in bilateral frontal cortex,bilateral temporal cortex,bilateral parietal cortex,posterior cingulate gyrus and cerebellar cortex of each group of images.And then,the corresponding mean standardized uptake value(SUVmean)of each region was obtained.The differences of SUVmean values of different ROI values between each group of data images and the images of 0-20 min were compared and analyzed.Results:There were significant differences in SUVmean between the acquired images in 0-1,0-3,0-5 and 0-10 min and the acquired standard images of 0-20 min(t=-7.569--2.410,P<0.05),respectively.There were no significant differences in SUVmean between the acquired images of 0-15 min and the acquired standard images of 0-20 min in the bilateral frontal lobe,bilateral temporal lobe,bilateral parietal cortex and posterior cingulate gyrus(P>0.05),only there was significant difference in the cerebellar cortex area between them(t=-5.597,P<0.001).Conclusion:The results of 15 min can reach to the similar results of 20 min in acquiring images,which can shorten the time of examination,and enhance the degrees of comfort and cooperation of patients in examination.It has clinical application value.

Objective:To investigate the association between body composition and coronary artery calcification in patients with chronic kidney disease (CKD).Methods:This cross-sectional study enrolled patients with CKD hospitalized from May 2019 to April 2022 at Sun Yat-sen Memorial Hospital, Guangzhou, China. Skeletal muscle mass index and visceral fat area were measured by bioelectrical impedance analysis. Coronary artery calcification was assessed by computed tomography. Patients were divided into coronary artery calcification group and non-coronary artery calcification group according to the incidence of coronary artery calcification. Patients were categorized into tertile groups according to their skeletal muscle mass index and visceral fat area levels ranging from the lowest to the highest levels (T1 to T3). We defined skeletal muscle mass index≤30.4% as low muscle mass and visceral fat area≥80.6 cm 2 as high visceral fat based on the results of the restricted cubic spline graph. All individuals were divided into 4 phenotypes: normal body composition, low muscle mass, high visceral fat, and low muscle mass with high visceral fat. Spearman correlation analysis and logistic regression analysis were used to assess the association between skeletal muscle mass index, visceral fat area and coronary artery calcification. Results:A total of 107 patients with CKD were enrolled, with an age of (60.0±14.1) years, including 41 female patients (38.3%). Patients of coronary artery calcification group had lower skeletal muscle mass index ((32.0±4.8) vs. (34.3±4.8), P=0.016) and higher visceral fat area ((70.8±32.6) cm 2 vs. (47.9±23.8) cm 2, P<0.001) than those of non-coronary artery calcification group. Patients in the T3 group of skeletal muscle mass index had a lower prevalence of coronary artery calcification (17 (48.6%) vs. 28 (77.8%)) and a lower coronary artery calcification score (0.5 (0, 124.0) vs. 12.0 (0.3, 131.0)) than those in the T1 group ( P<0.05). Similarly, patients in the T1 group of visceral fat area had a lower prevalence of coronary artery calcification (14 (40.0%) vs. 29 (80.6%)) and a lower coronary artery calcification score (0 (0, 3.0) vs. 37.0 (2.0, 131.0)) than those in the T3 group ( P<0.05). Likewise, patients with both low muscle mass and low muscle mass with high visceral fat had a higher prevalence of coronary artery calcification (11(78.6%) vs. 33 (47.8%); 15 (83.3%) vs. 33 (47.8%)) and a higher coronary artery calcification score (31.1 (0.8, 175.8) vs. 0 (0, 16.4); 27.6 (6.4, 211.4) vs. 0 (0, 16.4)) than those with normal body composition ( P<0.05). Spearman correlation analysis showed that skeletal muscle mass index was inversely correlated with coronary artery calcification score ( r=-0.212, P=0.028), and visceral fat area was positively correlated with coronary artery calcification score ( r=0.408, P<0.001). Multivariate logistic regression analysis showed that increased skeletal muscle mass index was inversely associated with coronary artery calcification prevalence (T2: OR=0.208, 95% CI: 0.056-0.770, P=0.019; T3: OR=0.195, 95% CI: 0.043-0.887, P=0.034), and reduced visceral fat area was inversely associated with coronary artery calcification prevalence (T1: OR=0.256, 95% CI: 0.071-0.923, P=0.037; T2: OR=0.263, 95% CI: 0.078-0.888, P=0.031). Consistently, both low muscle mass and low muscle mass with high visceral fat were associated with coronary artery calcification prevalence ( OR=6.616, 95% CI: 1.383-31.656, P=0.018; OR=5.548, 95% CI: 1.062-28.973, P=0.042). Conclusion:Reduced skeletal muscle mass index and increased visceral fat area are significantly associated with both the prevalence and severity of coronary artery calcification in patients with CKD.

Nuclear emergency medical rescue is one of the important courses of military medical professional education, and improving the training level of nuclear emergency medical rescue plays a very important role in improving post competency of trainees. Based on the problem of disconnection between "teaching" and "need" in the occupational education of nuclear emergency medical rescue in the past, this study proposes the curriculum goal of "the combination of three abilities" and performs the optimization and practice of the occupational education curriculum system of nuclear emergency medical rescue from the aspects of curriculum setting, curriculum content, teaching methods, and assessment and evaluation. The results show that the new curriculum system can significantly improve the comprehensive ability of nuclear emergency medical rescue among trainees and better meet the requirements for their posts, thereby playing an important role in cultivating high-quality military medical talents in nuclear emergency medical rescue.

Objective:To investigate the effects of apolipoprotein E (APOE) ε4 allele on β-amyloid (Aβ) deposition in subcortical structures and functional connectivity (FC) between brain regions in patients with Alzheimer′s disease (AD). Methods:Forty-three patients with probable mild/moderate AD were prospectively enrolled from the First Medical Centre, Chinese PLA General Hospital between January 2023 and October 2023, including 23 APOE ε4+ patients (12 males and 11 females, age (74.8±8.4) years), 20 APOE ε4- patients (14 males and 6 females, age (77.6±8.9) years) and 20 normal cognitive volunteers (NC) (15 males and 5 females, age (75.3±6.2) years). All subjects underwent 11C-Pittsburgh compound B (PIB) PET/MR brain imaging. The differences of gray matter volume (GMV) in subcortical structures (hippocampus, amygdala) among the three groups were analyzed by one-way analysis of variance and least significant difference (LSD) t test. Independent-sample t test and Pearson correlation analysis were used to analyze difference in Aβ deposition between APOE ε4+ patients and APOE ε4- patients, and the correlation between subcortical structure and brain FC. Results:The GMV of bilateral amygdala between NC group and APOE ε4+ gene carrier group, and between APOE ε4+ and APOE ε4- gene carrier groups were significantly different ( F=6.43, P=0.002; P values: 0.002, 0.003). Significant difference of GMV was observed in the bilateral hippocampus among three groups ( F=5.34, P=0.030). Abnormal PIB uptake was detected in both the hippocampus and amygdala of both APOE ε4+ and APOE ε4- gene carrier groups, with a more pronounced effect observed in the APOE ε4+ group ( t values: 3.14, 2.19, P values: 0.032, 0.009). Taking the hippocampus as the seed point, there was no obvious abnormality in the whole brain connectivity map among APOE ε4+, APOE ε4- carriers and NC groups. With the amygdala as the seed point, the whole brain connectivity in the APOE ε4+ gene carrier group was significantly reduced, and the connectivity between the amygdala and the cingulate gyrus, parietal lobe and temporal lobe was significantly reduced in the APOE ε4+ gene carrier group compared with NC group, while the connectivity between the amygdala and the whole brain was not significantly reduced in the APOE ε4- gene carrier group. Aβ deposition in amygdala was positively correlated with FC coefficients of frontal brain regions, gyrus rectus, right middle occipital gyrus and left temporal lobe ( r values: 0.56-0.70, all P<0.05). Conclusion:APOE influences GMV and Aβ deposition of hippocampus and amygdala, and FC of amygdala, and may be involved in the pathological mechanism of cognitive impairment.

Objective To investigate the causal relationship between gut microbiota and pigmented villonodular synovitis using Mendelian randomization analysis.Methods We conducted a two-sample Mendelian randomization analysis to investigate the causal relationship between 211 gut microbiome taxa and pigmented villonodular synovitis based on GWAS summary data,with inverse variance weighted(IVW)analysis as the primary result and the other methods as supplementary analyses.The reliability of the results was tested using Cochran's Q test,MR-Egger regression,MR-PRESSO method and conditional Mendelian randomization analysis(cML-MA).Results The increased abundance of Barnesiella(OR=3.12,95%CI:1.15-8.41,P=0.025)and Rumatococcaceae UCG010(OR=4.03,95%CI:1.19-13.68,P=0.025)may increase the risk of pigmented villous nodular synovitis,and elevated abundance of Lachnospiraceae(OR=0.33,95%CI:0.12-0.91,P=0.032),Alistipes(OR=0.16,95%CI:0.05-0.53,P=0.003),Blautia(OR=0.20,95%CI:0.06-0.61,P=0.005),and Lachnospiraceae FCS020 group(OR=0.38,95%CI:0.15-0.94,P=0.036)and Ruminococcaceae UCG014(OR=0.36,95%CI:0.14-0.94,P=0.037)were all associated with a reduced risk of pigmented villonodular synovitis,which were supported by the results of sensitivity analyses.Reverse Mendelian randomization analysis did not reveal any inverse causal association.Conclusion Increased abundance of specific intestinal microorganisms is associated with increased or decreased risks of developing hyperpigmented villonodular synovitis,and gut microbiota plays an important role in the pathogenesis of this disease.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Persistent Organic Pollutants (POPs) have the characteristics of resistance to environmental degradation, bioaccumulation and long-distance migration potential. Maternal exposure to POPs during pregnancy can enter the fetal blood circulation through the placental barrier, and have a potential impact on the functional development of the nervous system of the offspring. This in turn leads to the occurrence and development of neurological defects and diseases in adulthood. The purpose of this paper is to elucidate the effects of exposure to three major POPs (organochlorine compounds, perfluoroalkyl and polyfluoroalkyl substances, and polybrominated diphenyl ethers) during pregnancy on the functional development of the nervous system (social emotions, cognition, language, exercise, and adaptability) in children, and to provide reference for subsequent studies.

Objective To investigate the causal relationship between gut microbiota and pigmented villonodular synovitis using Mendelian randomization analysis.Methods We conducted a two-sample Mendelian randomization analysis to investigate the causal relationship between 211 gut microbiome taxa and pigmented villonodular synovitis based on GWAS summary data,with inverse variance weighted(IVW)analysis as the primary result and the other methods as supplementary analyses.The reliability of the results was tested using Cochran's Q test,MR-Egger regression,MR-PRESSO method and conditional Mendelian randomization analysis(cML-MA).Results The increased abundance of Barnesiella(OR=3.12,95%CI:1.15-8.41,P=0.025)and Rumatococcaceae UCG010(OR=4.03,95%CI:1.19-13.68,P=0.025)may increase the risk of pigmented villous nodular synovitis,and elevated abundance of Lachnospiraceae(OR=0.33,95%CI:0.12-0.91,P=0.032),Alistipes(OR=0.16,95%CI:0.05-0.53,P=0.003),Blautia(OR=0.20,95%CI:0.06-0.61,P=0.005),and Lachnospiraceae FCS020 group(OR=0.38,95%CI:0.15-0.94,P=0.036)and Ruminococcaceae UCG014(OR=0.36,95%CI:0.14-0.94,P=0.037)were all associated with a reduced risk of pigmented villonodular synovitis,which were supported by the results of sensitivity analyses.Reverse Mendelian randomization analysis did not reveal any inverse causal association.Conclusion Increased abundance of specific intestinal microorganisms is associated with increased or decreased risks of developing hyperpigmented villonodular synovitis,and gut microbiota plays an important role in the pathogenesis of this disease.