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 analyze the influencing factors of chronic liver failure in patients with primary hepatic carcinoma(PHC)before intervention,and to establish and evaluate a nomogram risk prediction model.Methods A retrospective analysis was conducted by collecting general data and clinical test data within 24 hours of admission for PHC patients.Univariate analysis and Lasso regression were used for variable selection,followed by multivariate logistic regression analysis to identify independent influencing factors for CLF before PHC intervention,leading to the establishment of a nomogram risk prediction model.The model was evaluated using the Hosmer-Lemeshow test,receiver operating characteristic(ROC)curve,calibration curve,clinical decision curve,and clinical impact curve.Result A total of 353 cases of PHC patients were collected,including 153 cases in the liver failure group and 200 cases in the non-liver failure group,with a prevalence rate of 43.3％.Variables selected by Lasso regression included gastrointestinal bleeding,prothrombin time(PT),albumin(ALB),total bilirubin(TBIL),and gamma glutamyl transferase(GGT).Multivariate logistic regression analysis showed that gastrointestinal bleeding(OR=13.549,95％CI:2.899～63.322,P=0.001),PT(OR=1.599,95％CI:1.282～1.995,P＜0.001),TBIL(OR=1.016,95％CI:1.006～1.025,P=0.002),and GGT(OR=1.002,95％CI:1.000～1.003,P=0.028)were independent risk factors for chronic liver failure prior to PHC intervention,leading to the establishment of a nomogram risk prediction model.The Hosmer Lemeshow test showed that the model had a good fit(x2=6.152,P＞0.05);the area under ROC was 0.902(0.869-0.934),with a sensitivity of 80.4％and a specificity of 87.5％.The calibration curve indicated that the model predicts chronic liver failure prior to PHC intervention with good consistency.Clinical decision curve analysis and clinical impact curve analysis showed that the model has good clinical utility within a certain threshold range.Conclusion Gastrointestinal bleeding,PT ≥16.05s,TBIL≥37.80 mmol/L,and GGT≥ 99.00 U/L are independent risk factors for the occurrence of chronic liver failure before PHC intervention.The established nomogram risk prediction model has certain clinical application value in predicting the risk of chronic liver failure before PHC intervention.

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 To explore the effectiveness of high-definition diffusion weighted imaging(DWI)sequence combined with T1 WI-fat suppression(FS)dynamic contrast enhancement(DCE)sequence for preoperative T-stage of rectal cancer by using 3.0T MRI standardized scanning.Methods A retrospective analysis was conducted on MRI images of 57 patients with rectal cancer confirmed by pathology.Before surgery,the patients underwent 3.0T MRI standardized rectal cancer scan methods,including routine sequence,high-definition DWI sequence,and T1 WI-FS DCE sequence,etc.Then two experienced physicians evaluated the T-stage of preoperative rectal cancer through high-definition DWI(transverse and sagittal sections)and T1 WI-FS DCE sequences in the double-blind method.Using the postoperative pathological results of rectal cancer as the"gold standard",two sequences were combined to evaluate the accuracy,sensitivity,and specificity of rectal cancer T-stage.Results Among the 57 cases,there were 9 cases of upper rectal cancer,39 cases of middle rectal cancer,and 9 cases of lower rectal cancer.The accuracy rates of preoperative T-stage diagnosis for rectal cancer by two evaluator were both 85.7％(6/7)in T1 stage,88.2％(15/17)and 94.1％(16/17)in T2 stage,96.9％(31/32)and 93.8％(30/32)in T3 stage,and both 100.0％(1/1)in T4 stage.For evaluator 1,the sensitivity and specificity of the rectal cancer T-stage diagnosis were 96.1％and 83.3％,and for evaluator 2 were 94.1％and 83.3％,respectively.For rectal cancer MRI diagnosis,the accuracy rates and sensitivity were higher when combining the high-definition DWI sequence and T1 WI-FS DCE sequence,compared with a single high-definition DWI sequence or T1 WI-FS DCE sequence,and the difference was statistically significant.The average preoperative apparent diffusion coefficient(ADC)value of rectal cancer was compared between the corresponding postoperative pathological T1 to T4 stage groups,and the difference was statistically significant.Conclusion The combination of high-definition DWI sequence and T1 WI-FS DCE sequence improves the accuracy of rectal cancer T-stage,providing assistance for personalized clinical treatment.

OBJECTIVE To explore the effect and safety of dapagliflozin on cardiac function and renal function， blood glucose， and quality of life in patients with heart failure （HF） combined with chronic kidney disease （CKD）. METHODS A total of 156 patients with HF combined with CKD admitted to Shangqiu First People’s Hospital from January 1， 2021 to January 1， 2023 were included. According to the random number table， the patients were randomly divided into conventional treatment group （n＝80） and dapagliflozin group （n＝76）. Conventional treatment group was given conventional treatment； dapagliflozin group was additionally given Dapagliflozin tablets 10 mg orally， once a day， based on conventional treatment group. Both groups were treated for 6 months. Cardiac function [left ventricular ejection fraction （LVEF）， left ventricular end-systolic diameter （LVESD）， left ventricular end-diastolic diameter （LVEDD）， N-terminal pro-brain natriuretic peptide （NT-proBNP）]， renal function [blood creatinine， urea nitrogen， urinary albumin excretion rate （UAER）， glomerular filtration rate （GFR）， creatinine 806731979@qq.com clearance rate （CCR）]， glycosylated hemoglobin， and the quality of life were observed in 2 groups before and after treatment. The occurrence of ADR was recorded. RESULTS After treatment， LVESD， LVEDD， NT-proBNP， blood creatinine， urea nitrogen， UAER in 2 groups as well as the level of glycosylated hemoglobin in dapagliflozin group were significantly lower than before treatment； the dapagliflozin group was significantly lower than the conventional treatment group. LVEF， GFR， CCR and Kansas City Cardiomyopathy Questionnaire score were significantly higher than before treatment， and the dapagliflozin group was significantly higher than the conventional treatment group （P＜0.05）. There was no statistical significance in glycosylated hemoglobin of conventional treatment group before and after treatment （P＞ 0.05）. There was no statistically significant difference in the incidence of dizziness， rash， liver dysfunction， urinary system infection， new dialysis and hypotension between the two groups （P＞0.05）. CONCLUSIONS Dapagliflozin can improve the cardiac function and renal function of patients with HF complicated with CKD， improve patients’ quality of life and lower blood sugar levels without increasing the risk of adverse events.

Objective To explore the interventional mechanism of Bufei Yishen formula on chronic obstructive pulmonary disease from pathway level.Methods Macrophage inflammatory model was established by LPS stimulation.Based on gene set enrichment analysis(GSEA)method,macrophage inflammation related pathways were screened,and normalized enrichment score(NES)was used to identify pathways that were reversed by traditional Chinese medicine treatment,revealing the interventional mechanism of Bufei Yishen formula and its compatibility.Results The NES of Bufei Yishen formula was-1377.23,among which the NES of Bushen compatibility was-485.07,that of Huoxue was-351.86,Huatan was-303.71,and Yiqi was-236.59.There were 213 significantly disturbed pathways reversed after the intervention of Bufei Yishen formula,among which there were 184 reversed pathways for Huoxue compatibility,147 reversed pathways for Bushen,134 reversed pathways for Huatan,133 reversed pathways for Yiqi,and the reversal rate was 75.41%,60.25%,54.92%,54.51%,respectively.90 pathways,including TGF-β production,were significantly reversed in the four compatibilities.Positive regulation of cytokine production involved in inflammatory response etc were specifically reversed pathways for compatibility.Conclusion The intensity of Bufei Yishen formula that reversed macrophage-inflammatory related pathways was in order of Bushen,Huoxue,Huatan and Yiqi compatibility.And the number of pathways that could be reversed by the compatibility of Bufei Yishen formula was Huoxue,Bushen,Huatan and Yiqi.Bufei Yishen formula could regulate the common and specific reversal pathways of the compatibilities to intervene the inflammatory response.

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.