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.

BackgroundWith the acceleration of population aging in China， studies have documented an increased prevalence of dementia in the elderly. Behavioral and psychological symptoms and impaired cognitive function are important problems affecting the quality of life in the elderly with dementia. It has been noted that there are certain limitations on the management of problems mentioned above by drug treatment alone， while its combination with music intervention is emerging as an effective approach. However， the application of this approach in the elderly with moderate to severe dementia is still in its relative infancy. ObjectiveTo investigate the effect of music assisted drug treatment on behavioral and psychological symptoms and cognitive function in the elderly with moderate to severe dementia， so as to provide insights for the development of effective intervention. MethodsA randomized controlled study was utilized to enroll a coherent of 43 elderly patients with moderate to severe dementia who were hospitalized in Geriatric Psychiatry of Deyang Mental Health Center from January to July 2023 and met the International Classification of Diseases， tenth edition （ICD-10） diagnostic criteria for dementia. Eligible subjects were divided into study group （n=22） and control group （n=21） based on random allocation using SPSS 26.0. Both groups received routine drug treatment and nursing care， while the study group added music intervention， which consisted of two 30-minute sessions per week for 8 weeks. Neuro Psychiatric Inventory （NPI） and Mini-Mental State Examination （MMSE） were administered to all patients before and after intervention. ResultsA total of 36 patients completed the study， including 20 case in study group and 16 case in control group. No statistical difference was noted in baseline NPI score and MMSE score between two groups （P>0.05）. After intervention， study group reported a statistical reduction in NPI total score ［58.00 （49.00， 79.25） vs. 78.50 （55.00， 95.50）， Z=-3.902， P<0.01）］ along with a clinically unremarkable increase in MMSE score （P>0.05） compared with baseline data. After intervention， NPI total score and scores on sub-domains including agitation/aggression， depression/dysphoria， anxiety and aberrant motor behavior were all significantly lower in study group than those in control group （Z=-2.183， -2.438， -2.691， -3.716， -2.250， P<0.05 or 0.01）， while there was no significant difference in MMSE score between two groups （P>0.05）. ConclusionMusic assisted drugintervention may ameliorate behavioral and psychological symptoms in the elderly with moderate to severe dementia， while no significant improvement is documented on cognitive function. ［Fund by the "14^th Five Year Plan" for Philosophy and Social Sciences Research in Deyang （number， DY232C002）］

Objective: To analyze the HLA typing and STR loci chimerism in a patient with recurrent acute lymphoblastic leukemia after HLA-haploidentical hematopoietic stem cell transplantation. Methods: HLA typing was performed on peripheral blood, buccal swabs and saliva samples after transplantation using PCR-sequence-specific oligonucleotide probes (PCR-SSOP) and next-generation sequencing (NGS). Additionally, STR analysis was conducted on these samples using a 21-locus STR assay kit to detect STR loci. Results: The HLA typing and STR locus outcomes of the patient's peripheral blood and the second saliva sample post-transplantation were in full concordance with the test results of the donor (father), whereas the HLA typing and STR locus results derived from the buccal swabs and the first saliva sample indicated chimerism between the donor and the recipient. Conclusion: In the follow-up and monitoring after transplantation, apart from focusing on peripheral blood samples, it is recommended to regularly monitor HLA typing and STR loci chimerism in patients' buccal swabs and saliva samples to comprehensively evaluate the transplantation effect and recurrence risk.

Objective: To analyze the HLA typing and STR loci chimerism in a patient with recurrent acute lymphoblastic leukemia after HLA-haploidentical hematopoietic stem cell transplantation. Methods: HLA typing was performed on peripheral blood, buccal swabs and saliva samples after transplantation using PCR-sequence-specific oligonucleotide probes (PCR-SSOP) and next-generation sequencing (NGS). Additionally, STR analysis was conducted on these samples using a 21-locus STR assay kit to detect STR loci. Results: The HLA typing and STR locus outcomes of the patient's peripheral blood and the second saliva sample post-transplantation were in full concordance with the test results of the donor (father), whereas the HLA typing and STR locus results derived from the buccal swabs and the first saliva sample indicated chimerism between the donor and the recipient. Conclusion: In the follow-up and monitoring after transplantation, apart from focusing on peripheral blood samples, it is recommended to regularly monitor HLA typing and STR loci chimerism in patients' buccal swabs and saliva samples to comprehensively evaluate the transplantation effect and recurrence risk.

Objective: Exploring the effect and mechanism of Xinyang Tablet on reduction of ferroptosis in myocardial cells from mice with chronic heart failure. Methods: Sixty C57BL/6J mice were randomly assigned to the sham, model, Xinyang Tablet low-dose (0.34 g/kg), Xinyang Tablet medium-dose (0.68 g/kg), Xinyang Tablet high-dose (1.36 g/kg), and perindopril (0.607 mg/kg) groups using a random number table method (10 mice in each group). Except for the sham group, all other groups underwent aortic arch constriction surgery to construct a chronic heart failure model. On the third day after completion of the modeling, each treatment group was administered the corresponding medication by gavage, while the sham and model groups were administered equal volumes of water by gavage once a day for eight consecutive weeks. After treatment, cardiac ultrasound was used to detect the structure and function of the mouse heart. Hematoxylin and eosin staining was used to detect pathological changes in mouse heart tissue. Masson staining was used to detect the proportion of fibrotic area of mouse heart tissue. Realtime fluorescence PCR was used to detect the mRNA expression of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), collagen 3α (Col3α), and myosin heavy chain 7 (MYH7) in mouse myocardial tissue. Transmission electron microscope was used to detect the ultrastructure of myocardial cell mitochondria. Reactive oxygen species (ROS) staining was used to detect the mean fluorescence intensity of ROS in myocardial tissue. Micro-determination was used to detect superoxide dismutase (SOD) activity in myocardial tissue. An immunofluorescence assay was used to detect the mean fluorescence intensity of phosphorylated histone deacetylase 2 (p-HDAC2) in myocardial cell. Western blotting was used to detect the protein expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), p-HDAC2, nicotinamide adenine dinucleotide phosphate oxidase 1 (NOX1), glutathione peroxidase 4 (GPX4), and cystine glutamate reverse transporter (xCT) in mouse myocardial tissue. Results: Compared to the sham group, the model group showed a decrease in left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), an increase in left ventricular end-systolic diameter(LVESD) and left ventricular end-diastolic diameter (LVEDD), an increase in the proportion of cardiac fibrosis area, an increase in relative expression levels of ANP, BNP, Col3α, and MYH7 mRNA, an increase in ROS mean fluorescence intensity, a decrease in SOD activity, an increase in mean fluorescence intensity of p-HDAC2, an increase in relative expression levels of p-HDAC2 and NOX1 proteins, and a decrease in relative expression levels of Nrf2, GPX4, and xCT proteins (P<0.05). Myocardial fibrosis lesions are obvious, with disordered mitochondrial arrangement, decreased volume and shrinkage, increased membrane density, and reduced mitochondrial cristae. Compared to the model group, the LVEF and LVFS of mice in each dose group of Xinyang Tablet and the perindopril group increased, LVESD and LVEDD decreased, the proportion of fibrotic area of heart tissue decreased, the relative expression levels of ANP, BNP, Col3α, MYH7 mRNA decreased, ROS mean fluorescence intensity decreased, SOD activity increased, mean fluorescence intensity of p-HDAC2 decreased, relative expression levels of p-HDAC2 and NOX1 proteins decreased, and relative expression levels of Nrf2 and xCT proteins increased (P<0.05). Myocardial fibrosis was reduced, the mitochondrial arrangement was more regular, the mitochondria enlarged, the membrane density was reduced, and mitochondrial cristae increased. Compared to the model group, the relative expression level of the GPX4 protein in myocardial tissue increased in the Xinyang Tablet medium-, high-dose, and the perindopril groups (P<0.05). Conclusion Xinyang Tablet can improve ferroptosis and ventricular remodeling in mice with chronic heart failure by regulating the HDAC2-mediated Nrf2 antioxidant pathway.

Objective Establish the method of bacterial endotoxins test for human papillomavirus bivalent(types 16,18)vaccine(pichia pastoris).Methods The method of gel-clot technique and photometric technique(kinetic-turbidimetric assay and kinetic-chromogenic assay)for the determination of bacterial endotoxins was carried out according to the Appendix of China Pharmacopoeia in 2020 Vol Ⅲ 1143"bacterial endotoxins test"and Vol IV 9251"guidelines for bacterial endotoxin test".Results There is no interference after more than forty times dilution for gel-clot technique,the recovery rates of kinetic-turbidimetric assay and kinetic-chromogenic assay can also meet the requirements.Conclusion It is feasible to establish gel-clot technique,kinetic-turbidimetric assay and kinetic-chromogenic assay for bacterial endotoxin test of human papillomavirus bivalent(types 16,18)vaccine(pichia pastoris).

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.

Objective:To explore the behavioral intentions of pediatric nurses towards using vascular visualization devices in light of the theory of planned behavior.Methods:This was a qualitative study. From March to November 2023, 20 pediatric nurses from Peking University First Hospital were selected using purposive sampling for semi-structured interviews. The interview data were analyzed and themes were extracted using Colaizzi 7-step analysis method.Results:The behavioral intentions of pediatric nurses towards the use of vascular visualization devices could be summarized into nine themes based on the theory of planned behavior. Attitudes towards behavior included positive evaluations, negative evaluations, and unclear information. Subjective norms involved peers' attitudes as well as expectations and pressures from patients. Perceived behavioral control encompassed workload, level of knowledge, more limited equipment performance, and external resource support.Conclusions:The behavioral intentions of pediatric nurses towards the use of vascular visualization devices are influenced by their attitudes towards the behavior, subjective norms, and perceived behavioral control. Nursing managers should conduct standardized training on vascular visualization devices to enhance nurses' knowledge and skills, while also valuing the sources of various supports to create a supportive environment for the use of vascular visualization devices. This will improve the usage experience of pediatric nurses and promote the use of vascular visualization devices in pediatric nursing practice.

The goal of Medical Immunology is to enable students to pay attention to integration of immunology theory with clini-cal practice,be familiar with professional English,consciously pay attention to cutting-edge knowledge,and can learn independently and lifelong.However,existing teaching models lack explanation of clinical disease related events,and arrangement of experimental content and projects is seriously disconnected from clinical practice,scientific research on solving clinical problems is clearly insuffi-cient.We established a"B to B"cycle model for immunology teaching by starting from clinical practical problems(Bedside),return to basic research(Bench),and then solve clinical problem(Bedside),which will comprehensively cultivate senior medical profession-als with clinical competence,scientific research thinking ability,innovative spirit,and international perspective.

Objective:To investigate the effects of using a high monounsaturated fatty acid (MUFA) and low carbohydrate formula on blood glucose levels and diarrhea treatment effects in critically ill neurological patients.Methods:A self-controlled before-and-after study design was employed, with 13 patients admitted to the neurology intensive care unit (ICU) of the First Affiliated Hospital of Sun Yat-sen University from November to December 2023, who were treated with a high MUFA and low carbohydrate formula [Glucerna enteral nutrition (EN) preparation]. Changes in blood glucose parameters within 7 days before and after the use of Glucerna EN preparation were analyzed, including standard deviation ( SD) of blood glucose, mean blood glucose (MG), median blood glucose, mean amplitude of glycemic excursions (MAGE), largest amplitude of glycemic excursions (LAGE), coefficient of variation ( CV) of blood glucose, the incidence of hyperglycemia (> 7.8 mmol/L) and severe hyperglycemia (> 13.9 mmol/L), and daily insulin dose. Changes in total protein (TP), albumin (ALB), hemoglobin (Hb), C-reactive protein (CRP), and white blood cell count (WBC) were observed before and after intervention. Improvement in diarrhea symptoms, Hart diarrhea score, Bristol Stool classification score, and incontinence dermatitis classification were also analyzed before and after the use of Glucerna EN preparation. Results:A total of 13 critically ill neurological patients were enrolled, among whom 9 patients had a history of hyperglycemia and 8 patients had diarrhea symptoms. After intervention with Glucerna, the patients' SD of blood glucose, MG, median blood glucose, MAGE, LAGE, CV of blood glucose, incidence of hyperglycemia, incidence of severe hyperglycemia, and daily insulin dose were all lower than those before the intervention [ SD of blood glucose (mmol/L): 1.83±1.11 vs. 2.10±1.13, MG (mmol/L): 8.87±2.03 vs. 9.75±1.37, median blood glucose (mmol/L): 9.12±1.67 vs. 10.17±0.48, MAGE (mmol/L): 0.66±0.31 vs. 0.78±0.32, LAGE (mmol/L): 4.95±3.64 vs. 5.58±3.10, CV of blood glucose: 16.00% (11.00%, 28.50%) vs. 18.00% (12.50%, 27.50%), hyperglycemia incidence: 47.31% vs. 74.66%, severe hyperglycemia incidence: 6.08% vs. 6.71%, daily insulin dose (U): 5.25 (0.00, 32.59) vs. 20.76 (0.00, 66.88)], with a significant decrease in daily insulin dose after the intervention ( P < 0.05); TP, ALB, Hb, CRP and WBC showed no significant changes before and after the intervention with Glucerna EN preparation. The improvement time of diarrhea symptoms after intervention was (3.50±1.41) days, and the Hart diarrhea score on the seventh day after intervention (4.88±3.48 vs. 10.00±3.38) and the Bristol Stool classification score on the third and seventh days after intervention (5.87±0.35, 5.50±0.53 vs. 6.50±0.53) were significantly lower than before the intervention (all P < 0.05). Before the intervention with Glucerna EN preparation, the classification of incontinence dermatitis was mainly classified as Grade 2 severity (71.43%); after the intervention, it significantly improved by the seventh day, with Grade 1 being the main classification (57.14%). Conclusion:The high MUFA and low carbohydrate formula has a positive effect on blood glucose control and diarrhea treatment in critically ill neurological patients.