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 establish a liquid chromatography method for the simultaneous determination of 13 aromatic amine compounds (AAs) in workplace air. Methods A total of 13 AAs in both vapor and aerosol phases were collected in workplace air using a new GDH-6 sampling tube. Samples were desorbed and eluted with methanol, separated using a Symmetry Shield™ RP₁₈ reversed-phase liquid chromatography column, and detected with a diode array detector. Quantification was performed using an external standard method. Results The linear range of the 13 AAs measured by this method was 0.02-373.60 μg/L with the correlation coefficients greater than 0.999 0. The minimum detection concentration was 0.09-14.37 μg/m³, and the minimum quantitative concentration was 0.31-47.90 μg/m³ (both calculated based on sampling 15.0 L of air and 3.0 mL of elution volume). The average desorption and elution efficiency ranged from 97.46% to 101.23%. The within-run relative standard deviation (RSD) was 0.10%-5.99%, and the between-run RSD was 0.17%-2.71%. Samples could be stably stored in sealed conditions at 2-8 ℃ for more than seven days. Conclusion This method is suitable for the simultaneous determination of 13 AAs in workplace air, including both vapor and aerosol phases.

Objective To establish a method for simultaneous determination of four high-molecular-weight thiol derivatives (TDs) in workplace air by gas chromatography. Methods The four kinds of vapor-phase macromolecular TDs (1-pentanethiol, 1-hexanethiol, 1-benzyl mercaptan, and n-octanethiol) in the workplace air were collected using the GDH-1 air sampling tubes, desorbed with anhydrous ethanol, separated on a DB-FFAP capillary column, and determined by flame ionization detector. Results The quantitation range of the four TDs was 0.30-207.37 mg/L, with the correlation coefficients greater than 0.999 00. The minimum detection mass concentrations and minimum quantitation mass concentrations were 0.18-0.32 and 0.60-1.05 mg/m³, respectively (both calculated based on the 1.5 L sample and 3.0 mL desorption solvent). The mean desorption efficiencies ranged from 87.07% to 103.59%. The within-run and between-run relative standard deviations were 1.92%-8.22% and 1.89%-8.45%, respectively. The samples can be stored at room temperature or 4 ℃ for three days and up to 7 days at -18 ℃. Conclusion This method is suitable for the simultaneous determination of four vapor-phase TDs in workplace air.

ObjectiveTo understand the monitoring result of occupational hazard in the workplace of key industries in Guangdong Province from 2020 to 2023. Methods The data of occupational hazards in the workplace of 20 key industries in Guangdong Province from 2020 to 2023 were collected from the “Workplace Occupational Hazard Monitoring System” of the Chinese Disease Prevention and Control System subsystem. The monitoring result of occupational hazard factors, occupational health training, occupational health examination, occupational protection, detection of occupational hazardous agents such as dust, chemical substances and noise were analyzed. Results A total of 13 058 enterprises from key industries were recruited as the monitoring subjects in Guangdong Province. There were 290 large-, 1 342 medium-, 7 635 small-, and 3 791 micro-enterprises, with small and micro-enterprises accounting for 58.5% and 29.0% of the total, respectively. A total of 7 542 enterprises exceeded the national standard in the detection of occupational hazards, with a rate of 57.8%. A total of 1 942 517 workers from 13 058 enterprises were recruited, with 835 567 workers were exposed to occupational hazards, with a rate of 43.0%. The rate of occupational health training for enterprise leaders, occupational health management personnel, and workers was 71.9%, 73.8%, and 86.5%, respectively. The abnormal rate of occupational health examinations for workers exposed to noise, dust, and chemical agents was 2.0%, 0.6%, and 1.0%, respectively. The distribution rate of dust masks, anti-poisoning masks or face masks, and noise prevention earplugs or earmuffs was 83.3%, 71.3%, and 77.8%, respectively. The rate of installation of dust prevention facilities, anti-poisoning facilities, and noise prevention facilities was 85.6%, 81.2%, and 50.1%, respectively. The rate of exceeded the national standard of dust, noise in the worksites/types and workplaces showed a decreasing trend year by year (all P<0.01), while the rate of exceeded the national standard of chemical agents in worksites/types and workplaces showed an increasing trend year by year in various occupational hazards (all P<0.01). Conclusion Occupational hazards in the workplace of key industries in Guangdong Province are relatively common. The proportion of workers exposed to occupational hazards is relatively high. It is necessary to further improve the use of noise prevention facilities and protective equipment, strengthen occupational health training for enterprises throughout the province and regularly monitor occupational hazards to reduce the risk of occupational diseases.

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.

Non-alcoholic fatty liver disease is a common chronic liver disease in clinical practice. In recent years, with increasing social attention to the health of women and the elderly, the prevention and treatment of non-alcoholic fatty liver disease after menopause has increasingly become a research hotspot in metabolic diseases. This study explores the pathogenesis and treatment method of non-alcoholic fatty liver disease in postmenopausal women based on the theory of "deficient qi and stagnation" and combined with the physiological and pathological characteristics of postmenopausal women and the Western medicine understanding of non-alcoholic fatty liver disease. We believe that the pathogenesis of non-alcoholic fatty liver disease in postmenopausal women is rooted in the "deficient qi" caused by depletion of liver and kidney essence and blood. The imbalance between the physical and functional aspects of the liver due to this "deficient qi" is the primary factor, while the "stagnation" of phlegm and blood stasis is the manifestation. Furthermore, the "deficient qi" and "stagnation" reinforce each other, with the deficiency leading to stagnation and stagnation exacerbating the deficiency, thus accelerating the progression of the disease. The treatment approach should be one that combines nourishing deficiency and resolving stagnation, addressing both root cause and maifestations. Given the female characteristic of "the liver as the innate organ" and the post-menopausal physiological state of "gradual decline of kidney essence", it is important to focus on nourishing the liver and kidneys, nurturing the liver′s physical body while maintaining its function, and also promoting the circulation of qi, resolving phlegm, and invigorating blood circulation to remove blood stasis. This approach aims to reduce the accumulation of lipids in the liver, offering a new perspective and approach for the treatment of non-alcoholic fatty liver disease in post-menopausal women with traditional Chinese medicine.

Objective:To construct the eukaryotic cell translation initiation factor 4A3(EIF4A3)short hairpin RNA(shRNA)lentiviral vector,and to establish the Neuro-2a-EIF4A3-shRNA stable transfection cell line.Methods:The EIF4A3 gene sequence was retrieved from the National Center for Biotechnology Information(NCBI)database;the PCR identification primers were designed and synthesized,and connected to the lentiviral GV493 vector digested with Eco R I and Age I enzymes to construct the GV493-EIF4A3-shRNA lentiviral plasmid;PCR method was used to screen the positive clones,which were sequenced for the identification;the GV493 empty plasmid and GV493-EIF4A3-shRNA recombinant plasmid were transfected into the HEK293T cells,regarded as GV493 control lentivirus and GV493-EIF4A3-shRNA lentivirus,respectively.After 48 h of transfection,the lentiviruses were collected for packaging and the viral titer was determined.The Neuro-2a cells were divided into blank group,GV493 control group,and GV493-EIF4A3 shRNA group.The Neuro-2a cells in blank group were untreated,and the Neuro-2a cells in GV493 control group and GV493-EIF4A3 shRNA group were infected with the respective lentiviruses at a multiplicity of infection(MOI)of 100.The infected Neuro-2a cells were selected by 10 mg·L-1 puromycin,and the growth status and green fluorescence expression of the Neuro-2a cells in various groups were observed under fluorescence microscope;real-time fluorescence quantitative PCR(RT-qPCR)and Western blotting methods were used to detect the expression levels of EIF4A3 mRNA and protein in the Neuro-2a cells in various groups.Results:The PCR sequencing results showed that the gene sequence of the GV493-EIF4A3-shRNA recombinant plasmid was consistent with the designed EIF4A3-shRNA sequence,indicating successful construction of the GV493-EIF4A3 lentiviral vector.The fluorescence microscope observation results showed that there was strong fluorescence expression and good growth status in the HEK293T cells,confirming successful lentiviral packaging.The viral titers for GV493 control lentivirus and GV493-EIF4A3-shRNA lentivirus both were 2×108 TU·mL-1.The growth status of the Neuro-2a cells in GV493 control group and GV493-EIF4A3 shRNA group was good,and they expressed green fluorescence,indicating successful construction of the stable transfection cell line.The RT-qPCR results showed that compared with blank group and GV493 control group,the expression level of EIF4A3 mRNA in the cells in GV493-EIF4A3 shRNA group was significantly decreased(P<0.01).The Western blotting results showed that the specific bands was at a relative molecular mass of 49 000,indicating successful EIF4A3 protein expression in the Neuro-2a cells.Compared with blank group and GV493 control group,the expression level of EIF4A3 protein in the cells in GV493-EIF4A3 shRNA group was significantly decreased(P<0.01).Conclusion:The GV493-EIF4A3-shRNA lentiviral vector is succfssfully constructed,and the Neuro-2a-EIF4A3-shRNA stable transfection cell line is established;the results provide the reference for the study of the effect of EIF4A3 on the intracranial atherosclerosis.

Objective:To construct an over-expression lentiviral vector of the dedicator of cytokinesis 4(DOCK4),and to establish DOCK4 stably over-expressing Neuro-2a cells.Methods:The DOCK4 sequence was searched in the National Center for Biotechnology Information(NCBI)and primers were designed and synthesized;polymerase chain reaction(PCR)method was used to amplify the DOCK4 gene sequences.After digestion with BamH Ⅰ and Age Ⅰ restriction endonucleases,the DOCK4 gene sequences were ligated with the digested lentiviral vector GV492 to construct the GV492-DOCK4 over-expression recombinant plasmid.The positive clones with a similar length to the target gene fragment were screened and identified by PCR method.The GV492-control plasmid and GV492-DOCK4 over-expression recombinant plasmid were transfected into the HEK293T cells,and the lentivirus was collected and titered 48 h after transfection.The Neuro-2a cells were divided into GV492-control group and GV492-DOCK4 group,and the cells were infected with GV492-control lentivirus and GV492-DOCK4 over-expression lentivirus,respectively,and the multiplicity of infection(MOI)was 100.After 72 h of infection,the successfully infected Neuro-2a cells were screened by using puromycin(10 mg·L-1).The growth status of Neuro-2a cells and the expression of green fluorescent protein in various groups were observed under fluorescence microscope.Real-time quantitative PCR(RT-qPCR)and Western blotting methods were used to detect the expression levels of DOCK4 mRNA and DOCK4 protein in the Neuro-2a cells in various groups.Results:The PCR results showed that the gene fragment length of the GV492-DOCK4 over-expression recombinant plasmid was approximately 691 bp.The sequencing results showed that the gene sequence of the GV492-DOCK4 over-expression recombinant plasmid was consistent with the designed over-expression sequence of DOCK4.The titers of the lentiviruses in GV492-control group and GV492-DOCK4 over-expression group were 2.5×108 TU·mL-1 and 2.5×108 TU·mL-1,respectively.The fluorescence microscope observation results showed that Neuro-2a cells in various groups grew well and expressed green fluorescent protein.The RT-qPCR results showed that compared with GV492-control group,the expression level of DOCK4 mRNA in the Neuro-2a cells in GV492-DOCK4 group was significantly increased(P＜0.01).The Western blotting results showed the specific bands near the relative molecular mass of 225 000 in various groups.Compared with GV492-control group,the expression level of DOCK4 protein in the Neuro-2a cells in GV492-DOCK4 group was significantly increased(P＜0.01).Conclusion:This study successfully constructs the DOCK4 over-expression lentiviral vector and establishes the Neuro-2a cells stably over-expressing DOCK4.

Objective:Based on the data compilation and analysis of the disease burden of esophageal cancer attributed to alcohol consumption in China over the past three decades(1990-2019),this study aims to explore how to strengthen the formulation and management of public health policies to control the disease burden caused by this disease. Methods:Based on the data from the Global Burden of Disease(GBD)2019 study database,indicators such as mortality rate and disability-adjusted life years(DALYs)were used to assess the disease burden of esophageal cancer attributed to alcohol consumption in China.Joinpoint regression software and the age-period-cohort model were employed to analyze the trends in disease burden and mortality rates over time by age,period,and cohort.Bayesian age-period-cohort analysis was used to predict the mortality rates of esophageal cancer attributed to alcohol consumption in China from 2020 to 2030. Results:From 1990 to 2019,the number of deaths from esophageal cancer attributed to alcohol consumption increased from 33 800 cases to 61 900 cases,while the standardized mortality rate decreased from 3.95 per 100 000 to 3.04 per 100 000.DALYs increased from 934 000 person-years to 1 512 600 person-years,and the DALYs rate decreased from 101.36 per 100 000 to 71.39 per 100 000.In 2019,both the number of deaths and DALYs reached their peak in the age group of 65-69 years with 58 800 deaths and a standardized mortality rate of 6.21 per 100 000 for males,and 3 100 deaths and a standardized mortality rate of 0.31 per 100 000 for females.Both the mortality rates and the DALYs rates increased with age.The Joinpoint regression analysis showed that the average annual percentage change(AAPC)of mortality rates attributed to alcohol consumption-related esophageal cancer was-0.97%[95%confidence interval(CI):-1.2%--0.8%],with an AAPC of-2.32%(95%CI:-2.6%--2.1%)for females and-0.81%(95%CI:-1.0%-0.6%)for males.The age-period-cohort analysis of mortality rates attributed to alcohol consumption-related esophageal cancer showed a net drift of-1.301%(95%CI:-1.577%--1.025%,P＜0.05).It is predicted that the burden of esophageal cancer mortality attributed to alcohol consumption will steadily increase during the period of 2020-2030. Conclusion:Compared to the overall trend of esophageal cancer burden,the burden of esophageal cancer attributed to alcohol consumption is declining at a slower rate.The burden of the disease is higher in the male population than that in females,and higher in the middle-aged and elderly population compared to the younger population.It is expected that in the coming years,the burden of esophageal cancer mortality attributed to alcohol consumption in China will steadily increase,suggesting that while focusing on the intervention for males and the middle-aged and elderly population,relevant departments should also strengthen health education in the entire population,formulate public health policies,and raise awareness of early prevention and risk factors of esophageal cancer among residents.

Objective To explore the mechanism of Yangxue Qingnao Granules(Siwu Decoction modified)in the treatment of hypertension based on network pharmacology and molecular docking.Methods The chemical composition analysis results of Yangxue Qingnao Granules in the early stage of the research group were used as the basis for the screening of active compounds.The oral bioavailability≥30%and drug-likeness≥0.18 were used as the screening conditions,and the blood components were supplemented in combination with the literature.TCMSP,chemical professional database and SWISS database were used to predict the targets of potential active compounds of Yangxue Qingnao Granules.Hypertension-related targets were obtained through GeneCards and DiGSeE databases.The intersection of the targets related to hypertension disease and the targets of the potential active compounds of Yangxue Qingnao Granules(common targets)is the potential target of Yangxue Qingnao Granules for the treatment of hypertension.The potential targets were matched with the potential active compounds of Yangxue Qingnao Granules to obtain the antihypertensive active compounds of Yangxue Qingnao Granules.PPI analysis was performed on the potential targets of serum brain granules in the treatment of hypertension through the STRING database,and the core targets were screened according to the degree value.The David database was used to analyze the GO function and KEGG pathway enrichment of the core targets.The core targets with the top six degrees were selected as the docking target proteins,and molecular docking verification was performed with the antihypertensive active compounds.Results A total of 32 potential active compounds,161 active compound targets and 1 539 hypertension-related targets were obtained.After intersection,88 potential targets(common targets)of Yangxue Qingnao Granules in the treatment of hypertension were obtained,involving 29 antihypertensive active compounds.PPI analysis screened 14 core targets:PPARG,ACHE,IL4,CCL2,JUN,NOS3,APP,IL1B,CAT,PTGS2,CASP3,TP53,TNF,IL6,involving 158 GO entries and 13 signaling pathways.Five key active ingredients,chlorogenic acid,rosmarinic acid,paeoniflorin catechinic acid and aloe emodin,were obtained by molecular docking,which were combined with PTGS2,CASP3,TNF,CAT,TP53 and IL6,respectively.Conclusion Yangxue Qingnao Granules may act on core targets such as PTGS2 and CASP3 through key active components such as chlorogenic acid and rosmarinic acid,regulate key pathways such as TNF signaling pathway,MAPK signaling pathway and Toll-like receptor signaling pathway,and play a role in the treatment of hypertension through anti-inflammatory effects.