BACKGROUND:Abutment screw loosening is one of the most common mechanical complications in implant restoration.Mechanical wear,as a potential cause of thread loosening,warrants attention due to its impact on mechanical performance and long-term stability.However,studies on the mechanical effects of thread wear in abutment screws remain limited,and no definitive conclusions have been reached.OBJECTIVE:To investigate the effect of different degrees of mechanical wear on the spatial stress distribution of the Morse taper connection implant system,with a view to providing a theoretical basis for the clinical assessment of the long-term stability of dental implants.METHODS:Three-dimensional finite element models of Morse taper implants with central screw thread wear levels of 0,0.1,1,10,and 100 μm were established using SolidWorks software,and simulation analysis with Ansys Workbench software was performed.The implant models were inserted into artificial bone blocks(simulating type Ⅱ bone,with a cortical bone thickness of 2 mm on the outer layer and cancellous bone inside).An alternating load of 300 N in the buccolingual direction was applied at the centroid of the abutment(forming an angle of 30° with the long axis of the implant).The von Mises stress,principal stress,displacement,and fatigue life of the abutment,central screw,implant,and bone tissue in the five groups of models were analyzed.RESULTS AND CONCLUSION:(1)As the degree of mechanical wear on the central screw thread increased,the von Mises stress,principal stress,and strain in the implant and abutment also increased.The stress in the model was concentrated at the top of the implant,at the shoulder level of the implant,at the neck of the abutment,and at the bottom edge of the abutment.(2)Under moderate wear conditions(≥ 10 μm),the fatigue life of the implant system decreased by 30％,and the maximum von Mises stress of the central screw decreased by 37％,with the stress still primarily concentrated at the transition area between the head and the body of the central screw.(3)Under significant wear conditions(≥ 100 μm),the von Mises stress of the central screw decreased by 98％,with the stress concentrated at the screw head,and the fatigue life of the implant system decreased by 63％.Therefore,when the wear level of the central screw thread reaches ≥ 10 μm,the risk of screw loosening is significantly increased,and the fatigue life of the implant system is markedly reduced,warranting clinical attention.

BACKGROUND:Abutment screw loosening is one of the most common mechanical complications in implant restoration.Mechanical wear,as a potential cause of thread loosening,warrants attention due to its impact on mechanical performance and long-term stability.However,studies on the mechanical effects of thread wear in abutment screws remain limited,and no definitive conclusions have been reached.OBJECTIVE:To investigate the effect of different degrees of mechanical wear on the spatial stress distribution of the Morse taper connection implant system,with a view to providing a theoretical basis for the clinical assessment of the long-term stability of dental implants.METHODS:Three-dimensional finite element models of Morse taper implants with central screw thread wear levels of 0,0.1,1,10,and 100 μm were established using SolidWorks software,and simulation analysis with Ansys Workbench software was performed.The implant models were inserted into artificial bone blocks(simulating type Ⅱ bone,with a cortical bone thickness of 2 mm on the outer layer and cancellous bone inside).An alternating load of 300 N in the buccolingual direction was applied at the centroid of the abutment(forming an angle of 30° with the long axis of the implant).The von Mises stress,principal stress,displacement,and fatigue life of the abutment,central screw,implant,and bone tissue in the five groups of models were analyzed.RESULTS AND CONCLUSION:(1)As the degree of mechanical wear on the central screw thread increased,the von Mises stress,principal stress,and strain in the implant and abutment also increased.The stress in the model was concentrated at the top of the implant,at the shoulder level of the implant,at the neck of the abutment,and at the bottom edge of the abutment.(2)Under moderate wear conditions(≥ 10 μm),the fatigue life of the implant system decreased by 30％,and the maximum von Mises stress of the central screw decreased by 37％,with the stress still primarily concentrated at the transition area between the head and the body of the central screw.(3)Under significant wear conditions(≥ 100 μm),the von Mises stress of the central screw decreased by 98％,with the stress concentrated at the screw head,and the fatigue life of the implant system decreased by 63％.Therefore,when the wear level of the central screw thread reaches ≥ 10 μm,the risk of screw loosening is significantly increased,and the fatigue life of the implant system is markedly reduced,warranting clinical attention.

BackgroundMonitoring the blood concentrations of antipsychotic drugs and their metabolites can guide the adjustment of clinical treatment plans， improving therapeutic efficacy while reducing adverse effects. However， there is currently a lack of a method that can accurately and efficiently quantitatively detect multiple antipsychotic drugs and their metabolites. ObjectiveTo establish a ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） method for the simultaneous identification and quantitation of 12 antipsychotic drugs and their main metabolites in human serum. MethodsUsing UPLC-MS/MS technology， protein precipitation method was employed for sample pretreatment. An Agela Technologies Durashell C₈ chromatographic column （50 mm×3.0 mm， 5 μm） was selected for chromatographic separation with gradient elution. The flow rate was 0.4 mL/min， and the total analysis time was 5 minutes. The column temperature was 40℃. The mass spectrometry detection was carried out in the multiple reaction monitoring （MRM） mode， and the isotope internal standard method was used for quantification. ResultsThe relative standard deviation （RSD） of the internal standard normalization matrix effect factor for 12 antipsychotic drugs and their main metabolites at low and high quality concentrations was all less than 15%. The extraction recovery rate was 85% to 115%. They showed good linear relationships within their respective standard curve ranges （r>0.995）. At low， medium， and high quality concentrations， the accuracy was 85.24% to 114.71%， and the RSD of intra-batch and inter-batch precision was all ≤14.15%， with good stability. ConclusionAll the analytical performance indicators of this method meet the verification requirements， providing an analytical means for the quantitative detection of antipsychotic drugs and their main metabolites in human serum. ［Funded by The Third Batch of Science and Technology Projects in Chaozhou City in 2023 （number， 202303GY02）］

Objective: To examine the prevalence of e-cigarette use and associated factors among primary and secondary school students in Pudong New Area, Shanghai, and to explore the pathways linking harm perception of e-cigarettes, interpersonal social influence, and attitudes toward e-cigarette use with experimentation behavior, in order to provide scientific basis for further optimizing the prevention and control strategies of e-cigarette among adolescents. Methods: From September to October 2025, a multi stage cluster random sampling method was used to select 5 144 primary and secondary school students aged 8-19 years from 47 primary and secondary schools in Pudong New Area, Shanghai, to conduct an anonymous questionnaire survey. The questionnaire collected information on e-cigarette use, harm perception of e-cigarette, interpersonal social influence, and attitudes toward e-cigarette use. The Chi-square test was applied to analyze the differences in cigarette and e-cigarette use behavior among primary and secondary school students with different demographic characteristics. Structural equation modeling (SEM) was constructed using Mplus 8.3 software, and the bootstrap method was utilized to test the mediating effects. Results: The reported rates of cigarette experimentation, e-cigarette experimentation, and current e-cigarette use among primary and secondary school students were 1.85%, 2.10%, and 0.70%, respectively. Higher reporting rates of e-cigarette experimentation were observed among boys (2.82%), secondary school students aged 16-19 (3.39%), senior high school students (3.05%), and those with weekly pocket money >100 yuan ( 6.11% ) ( χ 2=11.67, 8.61, 8.00, 54.18, all P <0.05). Structural pathway analysis results demonstrated that e-cigarette harm perception positively predicted interpersonal social influence ( β =0.61) and e-cigarette use attitude ( β = 0.53 ), and interpersonal social influence ( β =0.65) and e-cigarette use attitude ( β =0.25) further promoted e-cigarette experimentation behavior among primary and secondary school students (all P <0.01), with interpersonal social influence playing a major mediating role (indirect effect=0.40). Conclusions E-cigarette experimentation behavior among primary and secondary school students in Pudong New Area is jointly influenced by multiple psychosocial factors. Intervention strategies should strengthen interpersonal social factors such as family and peers on the basis of health education, thereby constructing a comprehensive prevention and control strategy for e-cigarette use among primary and secondary school students.

Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.

BACKGROUND:Carboxylesterase 1 and inflammatory factors play a crucial role in regulating lipid metabolism and glucose homeostasis.However,the effects of different exercise intensity interventions on carboxylesterase 1 and inflammatory factors in skeletal muscle of type 2 diabetic rats remain to be revealed. OBJECTIVE:To investigate the effects of different exercise intensity interventions on carboxylesterase 1 and inflammatory factors in skeletal muscle of type 2 diabetic rats. METHODS:Thirty-two 8-week-old male Sprague-Dawley rats were randomly divided into normal control group(n=12)and modeling group(n=20)after 1 week of adaptive feeding.Rat models of type 2 diabetes mellitus were prepared by high-fat diet and single injection of streptozotocin.After successful modeling,the rats were randomly divided into diabetic control group(n=6),moderate-intensity exercise group(n=6)and high-intensity intermittent exercise group(n=6).The latter two groups were subjected to treadmill training at corresponding intensities,once a day,50 minutes each,and 5 days per week.Exercise intervention in each group was carried out for 6 weeks.After the intervention,ELISA was used to detect blood glucose and blood lipids of rats.The morphological changes of skeletal muscle were observed by hematoxylin-eosin staining.The mRNA expression levels of carboxylesterase 1 and inflammatory cytokines were detected by real-time quantitative PCR.The protein expression levels of carboxylesterase 1 and inflammatory cytokines were detected by western blot and immunofluorescence. RESULTS AND CONCLUSION:Compared with the normal control group,fasting blood glucose,triglyceride,low-density lipoprotein cholesterol,insulin resistance index in the diabetic control group were significantly increased(P<0.01),insulin activity was decreased(P<0.05),and the mRNA and protein levels of carboxylesterase 1,never in mitosis gene A related kinase 7(NEK7)and interleukin 18 in skeletal muscle tissue were upregulated(P<0.05).Compared with the diabetic control group,fasting blood glucose,triglyceride,low-density lipoprotein cholesterol,and insulin resistance index in the moderate-intensity exercise group and high-intensity intermittent exercise group were down-regulated(P<0.05),and insulin activity was increased(P<0.05).Moreover,compared with the diabetic control group,the mRNA level of NEK7 and the protein levels of carboxylesterase 1,NEK7 and interleukin 18 in skeletal muscle were decreased in the moderate-intensity exercise group(P<0.05),while the mRNA levels of carboxylesterase 1,NEK7,NOD-like receptor heat protein domain associated protein 3 and interleukin 18 and the protein levels of carboxylesterase 1 and interleukin 18 in skeletal muscle were downregulated in the high-intensity intermittent exercise group(P<0.05).Hematoxylin-eosin staining showed that compared with the diabetic control group,the cavities of myofibers in the moderate-intensity exercise group became smaller,the number of internal cavities was reduced,and the cellular structure tended to be more intact;the myocytes of rats in the high-intensity intermittent exercise group were loosely arranged,with irregular tissue shape and increased cavities in myofibers.To conclude,both moderate-intensity exercise and high-intensity intermittent exercise can reduce blood glucose,lipid,insulin resistance and carboxylesterase 1 levels in type 2 diabetic rats.Moderate-intensity exercise can significantly reduce the expression level of NEK7 protein in skeletal muscle,while high-intensity intermittent exercise can significantly reduce the expression level of interleukin 18 protein in skeletal muscle.In addition,the level of carboxylesterase 1 is closely related to the levels of NEK7 and interleukin 18.

BACKGROUND:According to existing clinical studies,vertebroplasty treatment with both the external pedicle approach and the pedicle approach can improve the pain and quality of life of patients with spinal compression fractures.Compared with the pedicle approach,the external pedicle approach has a freer puncture angle,and good bone cement dispersion effect can be obtained by adjusting the puncture angle. OBJECTIVE:To compare the impact of vertebroplasty through individualized unilateral external pedicle approach and bilateral pedicle approach on the treatment of spinal compression fractures by quantifying the dispersion effect of bone cement. METHODS:A total of 80 patients with thoracolumbar compression fracture were divided into two groups by random number table method.The bilateral pedicle group(n=40)underwent vertebroplasty through a bilateral pedicle approach,while the unilateral external pedicle group(n=40)underwent individualized vertebroplasty through a unilateral external pedicle approach.Anteroposterior and lateral X-rays of the affected vertebrae from two groups of patients were photographed to assess effect and type of bone cement dispersion within 3 days after surgery.Visual analog scale score,tenderness threshold around fracture,and Oswestry dysfunction index were assessed before,1,7 days,and 1 month after surgery. RESULTS AND CONCLUSION:(1)Dispersion effect of bone cement in unilateral external pedicle group was better than that in bilateral pedicle group(P<0.001),and the amount of bone cement perfusion was higher than that in bilateral pedicle group(P<0.001).In the bilateral pedicle group,the bone cement dispersion types were mainly concentrated in type Ⅰ and type Ⅲ,while in the unilateral external pedicle group,the bone cement dispersion types were mainly concentrated in type I and type Ⅱ,and there was a significant difference in bone cement dispersion types between the two groups(P<0.001).(2)Postoperative visual analog scale scores and Oswestry disability index of both groups were lower than those before surgery(P<0.001),and postoperative tenderness threshold around fracture showed a trend of decreasing first and then increasing.At the same time point after treatment,there were no significant differences in visual analog scale score,Oswestry disability index,and tenderness threshold around fracture between the two groups(P>0.05).(3)The results indicate that individualized vertebroplasty via unilateral external pedicle approach can achieve better bone cement dispersion,and the treatment effect is consistent with the vertebroplasty via classical bilateral pedicle approach.

BACKGROUND: The benefits of ideal cardiovascular-health metrics (ICVHMs) in patients with renal insufficiency remain unclear. This study aimed to investigate the associations between ICVHM and prognosis in a renal insufficiency population. METHODS: The trial enrolled 29,682 participants from the US National Health and Nutrition Examination Survey (NHANES), 2007-2018, with mortality follow-up through December 31, 2019. Participants were divided into three groups based on estimated glomerular filtration rates. Cardiovascular health was assessed using new "Life's Essential 8" metrics. Cox regression analyses based on NHANES data were used to determine the associations between ICVHMs and cardiovascular mortality in patients with renal insufficiency. RESULTS: During a mean follow-up of 6.58 years, ideal cardiovascular health (hazard ratio [HR] = 0.42; 95% confidence interval [CI]; 0.25-0.70) and ideal health behavior (HR = 0.53; 95% CI; 0.39-0.73) reduced cardiovascular mortality in participants with renal insufficiency. For each one ICVHM increment, a 25% reduction in cardiovascular mortality was recorded (95% CI; 0.69-0.82). When compared with participants with normal renal function, for those with mild renal insufficiency, the HR for cardiovascular mortality gradually decreased from 1.47 (95% CI; 0.85-2.52) in those who had ≤1 ICVHMs to 0.30 (95% CI; 0.12-0.77) in participants who had >6 ICVHMs. CONCLUSIONS From an ICVHM perspective, enhanced cardiovascular benefits were observed in individuals with renal insufficiency, coupled with a reduced risk of all-cause mortality. Furthermore, when compared with individuals with normal renal function, increased ICVHMs can mitigate adverse risks associated with renal impairment.
Humans ; Male ; Female ; Nutrition Surveys ; Middle Aged ; Renal Insufficiency/physiopathology* ; Aged ; Prognosis ; Adult ; Cardiovascular Diseases/mortality* ; Glomerular Filtration Rate/physiology* ; Proportional Hazards Models