Aim To study the preventative effects of noninvasive delayed limb ischemic preconditioning ( NDLIP) on sudden cardiac death in rats with myocar-dial infarction. Methods Thirty healthy SD male rats weighting ( 250 ± 10 ) g were randomly divided into 3 groups:① myocardial infarction ( MI ) group: animal model of MI was established by making surgical ligation of animal LAD. ② MI plus NDLIP group: after the success of the animal model of MI, NDLIP was carried out every other day until 4th week. ③Sham group:as the negative control group, animals were taken heart LAD threading but no ligation. All rats were fed con-ventionally. At the end of 4 weeks, three groups of rats were administered with metaraminol ( 0. 2 mg · min-1 ) . ECG, drug cumulant of sudden death and death onset time were recorded. After sudden death, blood samples were withdrawn from abdominal aorta and serum was separated via centrifugation. ELISA method was used to measure serum caspase-3 , HSP70 and SOD concentration. Results While metaraminol led animal cardiac sudden death, the rats heart rate ( HR) kept declining with the increase of dosage of metaraminol during the administration period. Rat HR of MI+NDLIP group [ ( 479 ± 8 ) vs ( 416 ± 19 ) beat ·min-1 , ( 446 ± 32 ) vs ( 370 ± 20 ) beat · min-1 , (376 ± 53) vs (305 ± 29) beat·min-1, (307 ± 63) vs (244 ± 33) beat·min-1, (283 ± 45) vs (121 ± 35 ) beat · min-1 , P <0. 01 ] was markedly higher than that of MI group at 0 , 5 , 10 , 30 , 50 min before death. Compared with MI group, drugs cumulant to sudden death and death onset time of MI + NDLIP group [ ( 14. 58 ± 3. 03 ) vs ( 10. 76 ± 2. 73 ) mg, (72. 9 ± 15. 2 ) vs ( 53. 8 ± 13. 6 ) min, P <0. 01 ] were significantly increased. Compared with MI group, serum caspase-3 content of MI+NDLIP group was sig-nificantly reduced [ ( 2. 01 ± 0. 52 ) vs ( 2. 34 ± 0. 38 )μg·L-1 , P<0. 01 ]; HSP70 levels were remarkably increased [ ( 3. 01 ± 0. 58 ) vs ( 2. 70 ± 0. 43 ) μg · L-1 , P <0. 05 ]; SOD levels were significantly im-proved [(1. 99 ± 0. 65) vs (1. 70 ± 0. 58) mg·L-1, P<0. 01 ] . Conclusion NDLIP can prevent sudden cardiac death after myocardial infarction in rats, which may be mediated by reducing the myocardial cell apop-tosis, increasing protective protein expression and en-hancing antioxidant capacity.

AIM:To study the effects of noninvasive delayed limb ischemia preconditioning ( NDLIP) on ani-mal cardiac function , myocardial morphology and myocardial apoptosis after myocardial infarction ( MI ) .METHODS:Healthy SD male rats [n=45, weighing (250 ±10) g] were randomly divided into 3 groups:MI group:the animal model of MI was established by surgical ligation of left anterior descending artery ( LAD) after 2 weeks;NDLIP group:after the success of the MI animal model , NDLIP was carried out every other day until the 4th, 6th and 8th weeks;sham group:as the negative control group , the animals were taken heart LAD threading but no ligation .All rats were fed conventionally .At the end of the 4th, 6th and 8th weeks, all rats were made ventricular intubation , and then the hemodynamic parameters were recorded .The blood samples were withdrawn from the abdominal aorta and the serum was separated via centrifugation . The serum contents of Bcl-2 and Bax were measured by ELISA .Left ventricular anterior wall was homogenized .The mito-chondrial respiratory chain complexes Ⅰ,Ⅱ,Ⅲand Ⅳin the myocardial tissues were detected by ELISA .RESULTS:At the end of the 4th, 6th and 8th weeks, compared with MI group, left ventricular systolic pressure in NDLIP group was significantly increased , while left ventricular end-diastolic pressure in NDLIP group was significantly decreased ( both P<0.05).Mitochondrial respiratory chain complexesⅠ, Ⅱ, Ⅲ and Ⅳ in NDLIP group were significantly increased (P<0.05).The serum level of Bcl-2 in NDLIP group was significantly increased and Bax level was reduced remarkably (both P<0.01) .CONCLUSION:NDLIP improves the hemodynamic indexes , promotes the mitochondrial respiratory function and inhibits cell apoptosis , thus improving the prognosis of MI .

Objective:To identify multimorbidity patterns in a nationally representative sample of elderly patients with chronic diseases and to explore the relationship between these multimorbidity patterns and health care utilization.Methods:Based on data from the China Health and Retirement Longitudinal Study(CHARLS)in 2018, 10 764 elderly people aged 60 years and older were included, and latent class analysis(LCA)was used to identify multimorbidity patterns in the elderly, and the Logistic model was used to analyze the relationship between multimorbidity patterns and healthcare utilization in 8 041 elderly people with complete information on the variables.Results:The primary LCA identified five categories, with 4 164(52.1%)participants belonging to the relatively healthy category.The other four categories represented different patterns of multimorbidity, with 473(5.7%)belonging to the respiratory disease category, 1994(25.3%)to the vascular disease category, 948(11.7%)to the stomach-arthritis/rheumatism disease category and 426(5.2%)to the multisystemic disease category.In terms of outpatient service utilization, compared with the relatively healthy category, the multisystemic disease category was the most likely one to seek outpatient services( aOR=2.920, 95% CI: 2.305-3.699), followed by the respiratory disease category( aOR=1.827, 95% CI: 1.429-2.336), the stomach-arthritis/rheumatism disease category( aOR=1.680, 95% CI: 1.392-2.027), and the vascular disease category( aOR=1.482, 95% CI: 1.267-1.734).In terms of inpatient service utilization, compared to the relatively healthy category, the multisystemic disease category was the most likely one to seek inpatient services( aOR=2.718, 95% CI: 2.158-3.425), followed by the respiratory disease category( aOR=2.627, 95% CI: 2.105-3.280), the stomach-arthritic/rheumatism disease category( aOR=1.940, 95% CI: 1.624-2.318), and the vascular disease group( aOR=1.887, 95% CI: 1.632-2.183). Conclusions:There is a significant correlation between multimorbidity patterns and outpatient and inpatient service utilization in the elderly.Compared to relatively healthy people, those with one of the other four multimorbidity patterns have a significantly increased risk needing outpatient and inpatient services.

Objective:To study the root canal system in permanent anterior teeth by cone-beam computer tomography(CBCT).Methods:12 85g anterior teeth in 1 103 patients were divided into group A(≤40 years) and group B(＞40 years).The CBCT images of 6 404 maxillary anterior teeth and 6 454 mandibular anterior teeth were collected.The number of roots and root canals,crown-root length,the types of root canal configurations,symmetry,age-related changes and gender differences were analyzed statistically.The correlation of double root canals system in mandibular anterior teeth were compared.Results:All of the maxillary anterior teeth and mandibular incisors had only one root while 1.66％ double roots were found in canines.The prevalence of double root canals in maxillary and mandibular anterior teeth were 0.03％ and 11.25％ respectively,that of the lateral incisors was the highest(17.40％).Type Ⅰ was the most frequent type (88.75％) in permanent anterior teeth followed by Type Ⅲ (7.07％).There was symmetrical distribution of the bilateral root canals of anterior teeth.There was no statistical significance of crown-root length among different age groups in permanent teeth (P ＞ 0.05).The variation of the root canal rate increased gradually at the age of 18-50 years,decreased gradually after the age of 50.The incidence of double root canals was higher in males (13.12％)than in females (9.93 ％) in mandibular anterior teeth.The incidence of double root canals of mandibular central incisors was positively correlated with lateral incisors and canines respectively (P ＜0.05).Conclusion:The root canal morphology of mandibular anterior teeth is complicated.The prevalence of double root canals is symmetic,age-related and gender difference.

Objective:To investigate the effect of mind mapping on the discharge readiness of patients undergoing first coronary stent implantation, so as to provide basis for seeking effective discharge guidance in clinical practice.Methods:One hundred patients who were hospitalized in the Department of Cardiology, the Second Affiliated Hospital of Dalian Medical University from December 2019 to August 2020 and who underwent coronary stent implantation for the first time were selected as the study objects. They were divided into the control group and the experimental group with 50 cases in each group by the random number table method. The control group was given routine discharge guidance, and the experimental group was given discharge guidance using mind mapping. Readiness for Hospital Discharge Scale and Quality of Discharge Teaching Scale were used to compare the differences of discharge readiness and discharge guidance quality between the two groups after intervention.Results:The personal status, adaptability, predictive support and the total score of discharge readiness in the experimental group were (25.18 ± 3.79), (45.24 ± 3.63), (36.62 ± 3.63), (107.04 ± 8.92) points, which were all higher than those in the control group (23.34 ± 3.04), (41.68 ± 3.62), (35.14 ± 2.14), (100.16 ± 7.36) points, with statistically significant differences ( t values were -4.91--2.48, all P<0.05). The actual acquired content, guiding skills and results, total scores of discharge guidance quality of patients in the experimental group were (56.66 ± 6.06), (94.46 ± 4.33), (151.12 ± 8.26) points, which were all higher than those in the control group (45.38 ± 9.19), (89.44 ± 10.87), (134.82 ± 14.31) points, with statistically significant differences ( t values were -7.25, -3.03, -6.97, all P<0.05). Conclusions:Mind mapping can effectively improve the discharge preparation degree and discharge guidance quality of patients undergoing coronary stent implantation for the first time, and it is a simple and practical discharge guidance tool.

Objective:To understand the level of thirst distress in heart failure and analyze its influencing factors, in order to provide a theoretical basis for implementing the intervention measures to alleviate patients′ thirst distress.Methods:A total of 187 patients with heart failure who met the inclusion criteria from the First Affiliated Hospital and the Second Affiliated Hospital of Dalian Medical University from November 2019 to October 2020 were selected as the research objects. The General Information Questionnaire, Thirst Distress Scale-Heart Failure, Generalized Anxiety Disorder 7-item Scale, Patient Health Questionaire-9 and Brief Illness Perception Questionnaire were used to investigate heart failure patients. Multiple linear regression was used to explore the influencing factors of heart failure patients′ thirst distress.Results:The score of thirst distress in heart failure patients was (23.95 ± 4.21), multiple stepwise linear regression analysis showed that heart function grade, diuretic usage, anxiety, depression and disease perception were the influencing factors of thirst distress in patients with heart failure, which explained 41.9% of the thirst distress in heart failure patients.Conclusions:The thirst distress of heart failure patients is in the middle level, and its thirst distress is affected by many factors, clinical medical staff should pay attention to the severity of thirst distress in patients with heart failure, actively develop different intervention measures to reduce patients′ thirst sensation, and explore effective schemes to alleviate thirst distress in patients with heart failure.

Depression is a complex mental disease with polygenic inheritance and a high incidence.Our understanding of the clinical manifestations and pathogenesis of depression has recently improved.Continuous progress in gene-editing technologies has increased the construction efficiency and reduced the cost of gene-knockout animals,leading to their increasing use in the fields of basic research and drug development for depression and providing a powerful tool for revealing the pathogenesis of depression.In this review,we summarize recent progress in understanding the roles and mechanisms of candidate genes in depression using knockout model mice.

Objective To screen differentially expressed genes in lung adenocarcinoma by constructing Lasso-Cox model to provide potential gene targets for the research of lung adenocarcinoma and new directions for clinical diagnosis,treatment and prognosis by calculating patient risk score and constructing prediction model of lung adenocarcinoma.Methods The gene expression and clinical data of lung adenocarcinoma were downloaded from the Cancer Genome Atlas(TCGA)and Gene Expression Omnibus database(GEO).The TCGA database was used to train model,and the two databases were combined for model validation.The screened differentially expressed genes(DEGs)of lung adenocarcinoma were analyzed by univariate Cox and multivariate Lasso-Cox to construct a risk score prognosis model.Risk score from the final Cox prediction model and clinical data were combined to determine independent prognostic factors.GO enrichment analysis,KEGG pathway analysis and CIBERSORTx immunoassay were used to evaluate the biological interpretation of differentially expressed genes in the risk model.Results The analysis using univarate Cox and Lasso-Cox regreesion identified 9 differentially expressed genes associated with the prognosis of lung adenocarcinoma.Multivariate Cox regression analysis,incorporating clinical data,revealed that a history of malignant tumors,N stage,T stage,and the risk score were independent prognostic factors.Conclusion The prognositic model of lung adenocarcinoma can effectively predict the prognosis risk and provide a theoretical basis for clinical decision-making and personalized treatment.

Objective To explore the prognostic factors of colorectal cancer patients in gene data using random survival forest model.Method The differentially expressed genes were screened using the gene expression data of colorectal cancer in TCGA database,and combined with clinical and survival information.The RSF model is constructed and compared with the traditional Lasso-Cox regression model.Results The RSF model obtained 13 important factors affecting the prognosis of colorectal cancer patients,including HAND1(VIMP=0.090)and PCOLCE2(VIMP=0.075)genes,and analyzed the interaction between pathological N,PCOLCE2 gene and IGSF9 gene variables.Compared with Lasso-Cox model,the RSF model has better model calibration(IBS:training set:0.205 vs.0.214;test set:0.210 vs.0.221)although its prediction error rate is slightly higher(1-C-index:training set:0.296 vs.0.213;test set:0.369 vs.0.332).Conclusion RSF model has a good performance in processing the analysis of right censored survival data,can find important influencing factors and the interaction between variables,and provide scientific basis for the improvement of prognosis and quality of life of colorectal cancer patients.

Objective:To investigate the mediating effect of social interaction on the relationship between internet use and the health status of the elderly.The findings of this research can potentially contribute new insights into improving the health status of the elderly population.Methods:Based on the data from the Chinese General Social Survey(CGSS)in 2021, a total of 2 675 elderly individuals aged 60 and above were included in the study.The researchers analyzed the linear regression relationship between Internet use, social interaction, and the health status of the elderly using a hierarchical regression model.Additionally, a mediation effect test was conducted using the Bootstrap test.Furthermore, heterogeneity analysis of the mediation effect was performed considering factors such as gender, place of residence, working conditions, and physical exercise among the elderly participants.Results:The total effect value was 0.170.The direct effect of Internet use on the health status of older adults was 0.160(95% CI: 0.078-0.240), accounting for 93.66% of the effect value.The indirect effect of social interaction was 0.011(95% CI: 0.003-0.021), accounting for 6.34% of the effect value.The mediating effect of social interaction on the health status of older adults varied among different groups.Among female elderly, rural elderly, elderly who are currently unemployed, and those who are physically active, the mediating effects were 5.16%, 7.86%, 10.18%, and 9.91%, respectively. Conclusions:The impact of internet use and social interaction on the health status of the elderly is notably positive.Additionally, social interaction partially mediates the relationship between internet use and the health status of the elderly.