BACKGROUND:Post and core restoration is a common choice for tooth defects,but the repair effects of various post and core materials are different. OBJECTIVE:To evaluate the stress distribution at the post and core,tooth root,and bonding agent site of post and core models made of different elastic modulus post and core materials using finite element method. METHODS:A three-dimensional root canal treated maxillary central incisor model was built using three-dimensional modeling software,which was restored with a full ceramic crown.The post and core materials in the restoration used nanoceramic resin(elastic modulus=12.8 GPa),composite resin(elastic modulus=16 GPa),hybrid ceramic(elastic modulus=34.7 GPa),glass ceramic(elastic modulus=95 GPa),titanium alloy(elastic modulus=112 GPa),and zirconia(elastic modulus=209.3 GPa).The model was fixed in cortical bone.A 100 N concentrated force of 45° from the long axis of the tooth was applied to 1/3 of the crown and tongue side of the central incisor.The stress distribution of the post and core,dentin,and tooth-root bonding agent in the model was repaired by the maximum principal stress criterion. RESULTS AND CONCLUSION:(1)When the post and core materials with higher elastic modulus was used,the post-core stress in the repair model was more concentrated.When the elastic modulus of the post and core materials(nanoceramic resin and composite resin)was close to dentin,the stress distribution of the post and core was more uniform.The stress distribution of dentin in all restoration models was similar regardless of post and core materials.When the post and core with higher elastic modulus was used,more stress concentration was shown at the post and root bonding agent in the repair model.(2)The maximum stress values at the post and core,tooth root,and the bonding agent site of post and tooth root in the nanoceramic resin model were 31.00,33.21,and 0.51 MPa,respectively.The maximum stress values at the post and core,tooth root,and the bonding agent between the post and tooth root in the composite resin model were 36.84,33.14,and 0.59 MPa,respectively.In the mixed ceramic model,the maximum stress values at the post and core,tooth root,and the bonding agent between the post and tooth root were 64.05,32.83,and 1.00 MPa,respectively.In the glass ceramic model,the maximum stress values at the post and core,tooth root,and the bonding agent between the post and tooth root were 112.30,32.69,and 1.73 MPa,respectively.In the titanium alloy model,the maximum stress values of the post and core,tooth root,and the bonding agent between the post and tooth root were 120.00,32.17,and 1.86 MPa,respectively.In the zirconia model,the maximum stress values of the post and core,tooth root,and the bonding agent between the post and tooth root were 148.80,31.85,and 2.28 MPa,respectively.(3)The higher the elastic modulus of the post and core material,the higher the maximum stress at the post and core during restoration.The elastic modulus of the post and core material had no significant effect on the maximum stress of the dental bonding agent and dentin.

OBJECTIVE To analyze the characteristics and influencing factors of patient deaths caused by non-ionic iodine contrast media and provide recommendations for safe medication， thereby providing references for clinical application. METHODS Reports of fatal cases associated with non-ionic iodine contrast media were retrieved from databases including CNKI， Wanfang， VIP， PubMed， Cochrane Library， Web of Science， Embase， and SpringerLink. Statistical analysis was performed to examine the characteristics and influencing factors of these fatalities. RESULTS A total of 43 deaths caused by non-ionic iodine contrast media were retrieved， including 21 males （48.84%） and 22 females （51.16%）. The majority of deaths occurred in 32 patients aged 51-85 years old （74.42%）. The original diseases were mostly cardiovascular and cerebrovascular diseases （30.23%） and digestive system diseases （30.23%）， and only 2 cases had a clear allergy history （4.65%）. Among the lethal drugs， iohexol （37.21%） and iopromide （25.58%） accounted for the highest proportions. The main causes of death were anaphylactic shock （51.16%）， cardiac arrest （11.63%）， and pulmonary edema （11.63%）； 48.84% of the patients’ ADR occurred within 30 minutes， and 62.79% of the patients died on the first day. It mainly involved the circulatory system， nervous system and respiratory system， and the main manifestations were breathing difficulties， low or undetectable blood pressure， vomiting， etc. CONCLUSIONS The lethal drugs of non-ionic iodine contrast media are mainly iohexol and iopromide. The adverse reactions occur quickly. Clinically， it is necessary to focus on monitoring the vital signs within 30 minutes after medication， and timely treatment of symptoms such as dyspnea and abnormal blood pressure to reduce the risk of death.

OBJECTIVE: To study the durability of the anti-demineralization effects of fluoride varnish after being applied to dental root surfaces. METHODS: Coronal and radicular dentin samples were prepared from extracted human teeth. Duraphat^® (DP) was applied to the dentine surfaces to form a protective film. The film-dentin interfaces were observed by scanning electron microscopy (SEM) and the fluoride element was analyzed with energy dispersive spectrometer (EDS). Thus, the differences between applying DP on crowns and roots were compared. Radicular dentin samples were prepared and randomly divi-ded into four groups: (1) Blank: DP was not applied, and demineralized in acetic acid (pH 4.5) for 4 days; (2) Blank+aging: DP was not applied, the samples were put into deionized water for 14 days at room temperature, and then demineralized in acetic acid (pH 4.5) for 4 days; (3) DP: DP was applied and demineralized in acetic acid (pH 4.5) for 4 days; (4) DP+aging: DP was applied, the samples were put into deionized water for 14 days at room temperature, and then demineralized in acetic acid (pH 4.5) for 4 days. Finally, SEM observation and EDS analysis of fluoride content were performed on film-dentin interfaces to evaluate the degree of demineralization, the morphology of DP film, and the penetration of fluorine. RESULTS: The immediate penetration depth of fluoride element from DP was deeper in the coronal dentin than that in radicular dentin. The samples in the blank and blank+aging groups demine-ralized significantly after acid etching. The DP group did not undergo demineralization, and the fluorine element penetrated to (76.00±8.94) μm below the interfaces. The structure of the protective film in the DP+aging group was damaged, but the underneath dentin did not undergo demineralization. The fluorine element still remained at a depth of (5.00±3.53) μm below the interfaces. CONCLUSION DP has an anti-demineralization effect on the root surface, and this effect can still be exerted for a period of time after losing the structure of protective film. It has the ability to prevent root caries and a certain durability.
Humans ; Tooth Root/drug effects* ; Fluorides, Topical/pharmacology* ; Tooth Demineralization/prevention & control* ; Dentin/drug effects* ; Fluorides ; In Vitro Techniques ; Cariostatic Agents/pharmacology*

Objective To investigate the pathogenic bacteria distribution,clinical features and risk factors of urinary tract infection in patients with ischemic stroke. Methods A retrospective study was conducted on 634 patients with ischemic stroke in Beijing Bo'ai Hospital from Janu-ary,2020 to December,2023.They were divided into control group(n=551,without urinary tract infection)and observation group(n=83,with urinary tract infection)according to whether they developed urinary tract infec-tion.The incidence of urinary tract infection,the distribution of pathogenic bacteria and the resistance of main pathogenic bacteria to different antibacterial drugs were analyzed.The clinical characteristics of the two groups were compared and analyzed.The independent risk factors of urinary tract infection in patients with ischemic stroke were analyzed with multivariate Logistic regression. Results A total of 83 cases of 634 patients with ischemic stroke developed urinary tract infection,and incidence was 13.09%.A total of 127 strains of pathogenic bacteria were isolated from the urine samples of the observation group,of which Gram-negative bacteria accounted for 62.99%(80/127),Gram-positive bacteria accounted for 20.47%(26/127)and strains of fungi accounted for 16.54%(21/127).The main Gram-negative pathogens were Escherichia coli and Klebsiella pneumoniae,which were high resistant to second-generation and third-generation cephalosporins,co-trimoxazole,and levofloxacin;moderately resistant to carbapenems,β-lactamase inhibitor compound preparation and aminoglycosides,etc.;and highly sensitive to tigecycline and polymyxin,etc.The main Gram-positive pathogens were Enterococcus faecalis and Enterococcus faecalis,which were a high resistant to erythromycin and gentamicin,and highly sensitive to linezolid,daptomycin,teicoplanin and vancomycin.The pathogenic fungi detected were not obviously resistant to common antifungal drugs.The proportion of female,di-abetes,indwelling catheter and neurogenic bladder were significantly higher in the observation group than in the control group(χ2>5.043,P<0.05).The female,diabetes,indwelling catheter and neurogenic bladder were inde-pendent risk factors for urinary tract infection in patients with ischemic stroke(P<0.05). Conclusion The pathogenic bacteria of patients with ischemic stroke with urinary tract infection are mainly Gram-nega-tive bacteria,followed by Gram-positive bacteria and fungi.The Gram-negative bacteria showed multiple drug re-sistance.Meanwhile,female,diabetes,indentured catheter and neurogenic bladder are the independent risk fac-tors for urinary tract infection.

The release of the Measures of Ethical Review of Life Sciences and Medical Research Involving Humans has brought new requirements to the field of ethical review in health management research.Based on the background of new regulations and combining the characteristics of the health management discipline,this paper explored the needs and necessity of ethical review in health management research.In the Measures,the ethical governance of health management research was updated,the concept of exemption from the ethical review was put forward,as well as the importance of protecting the rights and interests of research participants and the protection of personal information were emphasized.This paper also explored the ethical review framework for health management research,including the formulation of operational standards for exemption from ethical review,the refinement of standardized ethical review work systems and processes,and the clarification of information data source verification.These explorations aimed to provide an ethical guarantee for health management research,promote its healthy development,and ensure that the rights and interests of research participants are fully respected and protected.Through research,it is hoped that the ethical level of health management research can be further improved,promoting the development of the discipline and social progress.

Objective:This study aimed to analyze the genomic characteristics of Varicella-Zoster Virus (VZV) strains circulating in Jilin province from 2010 to 2023.Methods:Vesicle fluid from 78 sporadic cases with VZV infection were collected in Jilin province from 2010 to 2023, after detecting by Real-time PCR, 26 specimens (CT<25) were detected by PCR. Open reading frame 22(ORF22), ORF38 and ORF62 were amplified and analyzed. Genotyping was confirmed by SNPs ORF22 (37902, 38019, 38055, 38081 and 38177) and ORF38 (69424). Vaccine strains were indentified from wild-type strains according to ORF38 (69349) and ORF62 (106262, 107252, and 108111). Sequences were analyzed by homologous comparison and phylogenetic analysis.Results:The comparison with Dumas sequence revealed that SNPs (37902, 38055, 38081 and 38177) in ORF22 and ORF38 (69424) have mutations similar to the pOka strain, which belong to clade 2. Compared to the Dumas and Baike strains, all 26 samples were wild-type strains. JL2016-4 strain changes from threonine to asparaginyl at position 38059, JL2021-4 strain changes from arginine to proline at position 37933, from aspartic acid to tyrosine at position 37935, and from aspartic acid at base 38031 to tyrosine. JL2023-1 strain changes from arginine to leucine at position 37933.Conclusions:VZV has been prevalent for 14 years in Jilin province. The main epidemic strains belong to the clade 2. We should strengthen the monitoring of VZV outbreaks and raise the coverage rate of VZV vaccination.

Objective To systematically evaluate the value of optical coherence tomography angiogra-phy (OCTA) for detecting the vessel density (VD) changes after open-angle glaucoma (OAG) surgery.Meth-ods The studies on OCTA for detecting the VD changes after OAG surgery were searched in the CNKI,WanFang,VIP,SinoMed,PubMed,Embase and Web of Science databases from the database establishment to May 2024.Literature screening,data extraction and risk of bias assessment of included studies were conducted independently by two reviewers.Descriptive analysis was adopoted for the systematic evaluation,the meta a-nalysis was conducted by using the R software and mean difference (MD) and its 95％CI were calculated.Re-sults A total of 13 studies were included,involving 472 patients with 500 tested eyes.The results of meta-a-nalysis showed that compared with pre-surgery,VD around the optic nerve head (ONH) and in nasal superi-or,temporal inferior,temporal superior,superior temporal and superior nasal regions at postoperative 6 months were significantly decreased.VD in the perimacular,perimacular superior hemisphere,permacular su-perior hemisphere,perimacular superior and permacular superior regions at postoperative 6 months were sig-nificantly increased.Conclusion OCTA could effectively detect the postoperative VD changes in the patients with OAG and predict postoperative visual function changes in glaucoma,and could serve as an effective test means for assessing the clinical treatment effect of the patients with OAG.

Objective To analyze the correlation between shear wave elastography(SWE)hardness measurements of calf muscle in diabetic mellitus patients and Michigan neuropathy screening instrument(MNSI)score.Methods A total of 102 patients with diabetes mellitus who were hospitalized in Lianyungang Hospital of Traditional Chinese Medicine from August 2020 to February 2022 were selected as study object.According to MNSI score,diabetes mellitus patients were divided into group A(0 points ≤MNSI score ≤ 1 point,20 cases),group B(1 point＜MNSI score ≤ 2 points,32 cases),group C(2 points＜MNSI score≤ 3 points,26 cases)and group D(3 points＜MNSI score ≤4 points,24 cases).Thirty normal volunteers were selected as control group.The values of Young modulus of calf gastrocnemius,tibialis anterior and peroneus were measured by SWE and compared under different tension states.Spearman correlation test was used to examine the relationship between MNSI score and Young modulus of calf muscle.Results With the increase of MNSI score,the Young modulus of each calf muscle shear wave decreased in all groups,and the differences between groups were statistically significant(P＜0.05).Young modulus of maximum plantar flexion of gastrocnemius,maximum dorsiflexion of gastrocnemius,maximum plantar flexion of tibialis anterior and peroneus foot varus in diabetic patients were negatively correlated with MNSI score(P＜0.05),and the correlation coefficients were-0.74,-0.73,-0.72 and-0.75,respectively.Conclusion With the aggravation of peripheral neuropathy in diabetes mellitus patients and the decrease of shear wave hardness of calf muscle,SWE can comprehensively evaluate diabetic peripheral neuropathy with MNSI score.

Objective By evaluating the publicly published literature on the budget impact analysis(BIA)of medical insurance in China,to investigate the accuracy of BIA prediction,analyze its influencing factors,and provide reference for medical insurance decision-making in China.Methods PubMed,Web of Science,CNKI,Wanfang and VIP Database were used to collect related literature about BIA research.The quality of included literature was quantitatively evaluated by Quality Assessment Scale for Budget Impact Analysis of the Medical Insurance.The accuracy analysis indicator was the ratio of predicted values to actual values of drug sales revenue.The t-test was used for univariate analysis,and the multiple linear regression analysis was used for multivariate analysis.Results A total of 11 articles were ultimately included in the study,with a scale evaluation score of 0.750 3±0.030 9.There were a total of 24 sample values included in the analysis.The results of univariate analysis showed that the literature score had a statistically significant impact on the accuracy of BIA prediction(P＜0.05),and the multivariate analysis showed that the accuracy of BIA prediction was influenced by literature review scores and average annual/course drug costs(F=7.844,P＜0.05).Conclusion The quality of the literature about medical insurance BIA research in China is good,but there are still problems in data citation,analysis content,and presentation of results.The accuracy of prediction is far from satisfaction,and the prediction values are generally higher than the actual values.It is recommended to increase the emphasis on the quality of medical insurance BIA research and strengthen the relevant research on the accuracy of medical insurance BIA.

Objective To explore the application of polysomnography combined with arterial spin labeling(ASL)perfusion magnetic resonance imaging in the diagnosis of insomnia.Methods Forty-two insomnia patients admitted to Department of Neurology were included as insomnia group,while 41 healthy subjects during the same period were included as control group.The two groups were assessed using sleep habits questionnaire,hospital anxiety and depression scale,polysomnography,and ASL perfusion magnetic resonance imaging.Results Compared with control group,insomnia group took significantly more time to fall asleep(P<0.05),and has shorter sleep duration(P<0.05).The differences in the levels of anxiety and depression between two groups were trivial.The total sleep time,rapid eye movement sleep duration,and non-rapid eye movement sleep stage S2-S4were shorter,while the sleep latency and non-rapid eye movement sleep stage S1were longer in insomnia group as compared with control group(all P<0.05).In insomnia group,perfusion was increased in bilateral prefrontal lobes,right temporal lobe,left parietal lobe,right thalamus,and pons(P<0.05),but decreased in bilateral insula and bilateral basal ganglia(P<0.05).Conclusion The combination of polysomnography and ASL perfusion magnetic resonance imaging enables precise quantification of sleep condition.