AIM: To screen and analyze the influencing factors of myopia among primary and secondary school students and establish a predictive model to provide ideas for the prevention and control measures of myopia among children and adolescents.METHODS:A total of 1 759 primary and secondary school students from 2 primary schools, 2 junior high schools, 2 senior high schools and 1 vocational high school in the urban area of Qingdao were sampled by means of stratified cluster sampling in September 2023. Vision screening and a questionnaire survey on influencing factors were carried out based on machine learning algorithms. The screening and determination were mainly conducted in accordance with the Standard Logarithmic Visual Acuity Chart(GB/T11533-2011)and the Specifications for Screening Myopia in Children and Adolescents. The influencing factors of myopia were analyzed and a prediction model was developed based on the machine learning algorithms LASSO in combination with XGBoost, and visualization was achieved through an interactive Nomogram. Statistical analysis was performed using R statistical software version 4.3.3.RESULTS:The screening prevalence of myopia among primary and secondary school students in the urban area of Qingdao was 70.61%(1 242 cases). The optimal predictive variables for screening were grade, gender, whether parents were myopic, daily indoor sedentary time, appropriate distance between eyes and books during reading and writing, daily sleep time, distance between eyes and TV screen when watching TV/playing video games exceeding 3 meters, the playground during breaks, total duration of tutorial classes, how often eyes are rested during near work, daily computer usage time, and average daily homework time after school, totaling 12 influencing factors. The AUCs of the training set and test set were 0.770(95%CI:0.751-0.789)and 0.732(95%CI:0.714-0.750), respectively.CONCLUSION: A machine learning-based prediction model was developed and validated to predict the risk of myopia onset in primary and secondary school students, accompanied by effective visualization techniques.

Objective:To analyze the association between waist circumference (WC) and ischemic stroke (IS).Methods:The data for the present study were from the prospective cohort study of China Kadoorie Biobank in Qingdao. Using baseline information and IS events of the participants, the Cox proportional hazard regression model and restricted cubic spline (RCS) were used to analyze the association between WC and IS.Results:A total of 33 355 participants were included in the study, with 302 008.88 person-years of follow-up. A total of 1 093 new cases of IS were observed. Multivariate Cox proportional hazard regression model analysis showed that compared to the respondents with normal WC (male <85.0 cm, female <80.0 cm), respondents with excessive WC (male ≥85.0 cm, female ≥80.0 cm) had a 78% higher risk of IS incidence [hazard ratio( HR)=1.78, 95% CI: 1.51-2.10], and the risk increased by 72% ( HR=1.72, 95% CI: 1.40-2.12) and 83% ( HR=1.83, 95% CI: 1.40-2.39) in men and women. According to the RCS, the increase in WC and the risk of IS showed an "S" trend of nonlinear dose-response relationship. Conclusions:The risk of IS would increase with the WC. Keeping a normal WC is important for preventing IS.

Objective:To understand the prevalence of chronic kidney disease (CKD) in adults in Qingdao.Methods:A multi-stage stratified random sampling method was used to select 6 240 local residents aged ≥18 years in Qingdao as study subjects from May 2019 to September 2020, the demographic data of the study subjects were collected by face-to-face survey method. The prevalence of CKD in adults in Qingdao were analyzed using software SPSS 25.0.Results:A total of 5 996 adults in Qingdao were included in this study. The overall prevalence rate of CKD in the adults was 8.22%. The prevalence rates of CKD in men and women were 7.70% and 8.74%, respectively. The prevalence rate of CKD was 10.28% in urban residents and 7.25% in rural residents, the differences in the prevalence of CKD among different age, educational level and marital status groups were significant ( P<0.001). The prevalence of CKD tended to increase with age and decrease with the increase of education level. Conclusions:The prevalence of CKD in adults of Qingdao was relatively high. It is necessary to actively carry out the early prevention and treatment of CKD and strengthen the screening and prevention of CKD to reduce the incidence and slow development of CKD.

Objective:To investigate the association between solid fuel use for heating, smoking, and respiratory diseases.Methods:This study is based on the Qingdao project of the China Kadoorie Biobank. After screening, 26 165 individuals were included in the study. We employed Cox proportional hazards regression models, stratified by risk age (in 5-year intervals) and sex while adjusting for confounding variables such as occupation and physical activity level to analyze the association between solid fuel use for heating, smoking, and increased risk of respiratory diseases.Results:Among the 26 165 participants, the average age of those using solid fuel for heating was (52.57±10.31) years, with females constituting 58.04% and former/current smokers accounting for 65.38%. The results indicated that both the solid fuel group and the former/current smoking group had a higher risk of respiratory diseases, with hazard ratios ( HR) (95% CI) of 1.21 (1.04-1.41) and 1.41 (1.16-1.71), respectively. For the duration of solid fuel use, the HR (95% CI) for 20 years or more, it was 1.27 (1.07-1.51). The multiplicative interaction term between solid fuel use and smoking was statistically significant. Conclusions:The use of solid fuel for heating and smoking significantly increases the risk of respiratory diseases, and there may be a multiplicative interaction between solid fuel use and smoking.

Objective:To describe the characteristics and change trends of incidence, mortality and disease burden of acute myocardial infarction (AMI) in Qingdao from 2014 to 2020.Methods:We analyzed the incidence data of AMI retrieved from Qingdao Chronic Diseases Surveillance System. The average annual percent change (AAPC) of morbidity and mortality of AMI were evaluated by using Joinpoint log-linear regression model. Disability adjusted life year (DALY) was used to estimate disease burden of AMI in Qingdao.Results:A total of 70 491 AMI cases and 50 832 deaths of AMI occurred in Qingdao from 2014 to 2020. The age-standardized morbidity and mortality were 54.71/100 000 and 36.55/100 000, respectively. During 2014-2020, the AAPC of age-standardized morbidity was 2.86% (95% CI: 0.42%-5.35%), and 4.30% (95% CI: 1.24%-7.45%) in men and 0.78% (95% CI: -0.89%-2.47%) in women, respectively. The log-linear regression model showed that age-standardized morbidity in age groups 30-39, 40-49 years increased rapidly, with the AAPCs of 8.92% (95% CI: 2.23%-16.06%) and 6.32% (95% CI: 3.30%-9.44%), respectively. The trend was also observed in age groups 30-39, 40-49 and 50-59 years in men, with the AAPCs of 11.25% (95% CI: 3.54%-19.54%), 6.73% (95% CI: 2.63%-10.99%) and 6.72% (95% CI: 2.98%-10.60%), respectively. There was no significant change in age-standardized mortality. The DALY rate increased from 7.49/1 000 in 2014 to 8.61/1 000 in 2020, with the AAPC of 1.97% (95% CI: 0.36%-3.60%). Conclusions:The age-standardized morbidity of AMI in men increased in Qingdao, especially in those aged 30-49 years, while age-standardized mortality rate of AMI was relatively stable from 2014 to 2020. The burden of disease of AMI increased in both men and women.

Heart failure, as a progressive and irreversible clinical syndrome, is an important part of the global prevention and treatment of chronic cardiovascular diseases. The management of its complex symptoms and risk factors cannot completely rely on medical and nursing staff and short-term clinical treatment. Self-care is an effective way to reduce the readmission rate and fatality rate of patients. Symptom perception is a new dimension in the situation-specific theory of self-care in heart failure, and that is a comprehensive process by which patients conduct self-monitoring of symptoms and signs and identify, interpret, and label the meaning of symptoms. Symptom perception of heart failure is crucial to achieve effective self-care, however, there are few studies in China. This article reviews the definition, influencing factors and evaluation tools of symptom perception in patients with heart failure, so as to provide evidence for the intervention and promotion of symptom perception in patients with heart failure.

Objective To provide the candidate antigens for immunological diagnosis by analyzing the expression of nu -cleoprotein ( NP) of Ebola virus. Methods BioSun software was used to predict the NP epitopes. The bridging-PCR was used to synthesize the NP gene. The pBVIL1 vector was used to clone and express the NP gene. Results The 360-739 aa of NP was confirmed to be the dominant antigen by BioSun software. The recombinant NP dominant antigen was expressed in E.coli with molecular weight of 58 ×103.The specificity of ELISA based on recombinant NP was 99.24% (130/131) in negative samples. Conclusions The dominant NP antigen can be potentially used for developing Ebola virus diagnostic reagent.

Objective To discuss the role of nucleic acid test(NAT)in blood screening to provide the scientific basis for the se-lection of blood screening strategies.Methods The serological detection and NAT were simultaneously performed on 68 662 speci-mens of voluntary blood donation from January 2012 to April 2013;29 samples of HBV DNA positive with serological HBsAg nega-tive were performed the serum HBV markers detection.Partial samples of anti-HIV antibody positive were sent to CDC for conduc-ting the confirmation test.Results Among 68 662 samples,120 cases of single NAT positive were detected out,the residual risk of blood transfusion was 0.175%.In the serum HBV markers detection,the mode of HBcAb was predominant.11 cases of HIV posi-tive were confirmed and all were the NAT positive samples.Conclusion NAT can reduce the residual risk of blood transfusion,en-sure the safety of blood transfusion.NAT and the serological detection are mutual complementation and not replaced by each other. The suitable screening strategy shold be selected.

OBJECTIVETo investigate the variations of hepatitis C virus (HCV) quasispecies and the changes in their composition in untreated patients with chronic hepatitis C.

METHODSEleven patients chronic hepatitis C without previous specific anti-HCV treatment were tracked for disease progression and blood samples were collected at multiple time points. The major clinical parameters of liver function and viral load were tested. A fragment of HCV hypervariable region 1 (HVR1) was amplified and cloned, and the positive clones were sequenced and subsequently analyzed to determine the composition variation of HCV quasispecies during disease progression in relation to the major clinical parameters.

RESULTSA total of 631 HVR1 sequences were acquired from the positive clones. The evolution of HCV HVR1 quasispecies in untreated chronic hepatitis C patients featured 3 patterns of variation in quasispecies composition, namely stable, fast and slow changes during the natural course of chronic hepatitis C. The genetic distance of the quasispecies was found to inversely correlated with ALT (R=-0.438, P=0.011) and AST level (R=-0.500, P=0.003), and sense mutation rate was also inversely correlated with ALT level (R=-0.387, P=0.026) and AST level (R=-0.410, P=0.018). No significant association was found between HCV load and any clinical or virological parameters.

CONCLUSIONDue to individual differences and immune pressure, HCV quasispecies can present with different patterns of evolution in the natural disease progression of chronic hepatitis C. HCV quasispecies evolution, due to its close correlation with the biochemical parameters, can be used to evaluate the severity and prognosis of chronic hepatitis C.

Objective To study the whole-genome evolution of influenza B viruses prevalent in Qingdao from 2006 to 2011 .Methods RNA was extracted from influenza B viruses isolated in Qingdao from 2006 to 2011 .Each gene segment was amplified by reverse transcription polymerase chain reaction ( RT-PCR) and then sequenced .Gene sequences of each virus were determined and assembled by using Sequench -er software .A phylogenetic analysis for each gene segment was conducted by using MEGA 5.0 software pack-age.Results The phylogenetic tree of hemagglutinin ( HA) gene showed that 13 strains from 2006 to 2009 belonging to V1 clade of Victoria lineage were B/Malaysia/2506/2004-like viruses,and 12 strains from 2009 to 2011 belonging to the V2 clade of Victoria lineage were B/Brisbane/60/2008-like viruses.Moreover, strains of Yamagata lineage were all B/Florida/4/2006-like viruses including 5 strains of Y1 clade circulated from 2006 to 2008 and 7 strains of Y2 clade circulated from 2010 to 2011, respectively.The analysis of whole-genome evolution showed that 3 viruses of V2 clade presented 5+3 reassortment and 1 virus presented 1+7 reassortment.All reassortant strains matched with the vaccine strains of the present and previous season . The Yamagata and Victoria lineage strains belonged to genotype 2 and genotype 15,respectively.Compared with vaccine strains , the HA1 protein of Victoria lineage strains showed mutations at amino acid sites of H14Q, L58P, N129S, I146V, N171D and R279K, while R48K, K88R, P108A, N116K, S150I, N165Y, D196N,N202S and S229G amino acid mutations were mainly detected in Yamagata lineage strains .The sites 116 and 129,150,165,196 and 202 located in the 120,150,160 and 190 loops,respectively,which had been previously determined to be the hotspots under positive selection .Conclusion Both Yamagata and Victoria lineages of influenza B viruses were prevalent in Qingdao and evolved continuously from 2006 to 2011 .The selective pressure that a vaccine would provide was only to virus strains belonging to the same lineage ,sug-gesting a bivalent vaccine may be better for the induction of protective immunity .