Objective: To analyze the temporal variation patterns of sickness absenteeism among primary and secondary school students in Shanghai, so as to explore models suitable for predicting peaks and intensity of absenteeism rates. Methods: The seasonal and trend decomposition using loess (STL) method was used to analyze the seasonal and long term trend changes in sickness absenteeism among primary and secondary school students from September 1 in 2010 to June 30 in 2018, in Shanghai. A hierarchical clustering method based on Dynamic Time Warping (DTW) was employed to classify absenteeism symptoms with similar temporal patterns. Based on historical data, the study constructed and evaluated different time series algorithms and machine learning models to optimize the accuracy of predicting the trend of sickness absenteeism. Results: During the research period, the average new absenteeism rate due to illness was 16.86 per 10 000 person day for every academic year, and the trend of sickness absenteeism exhibited both seasonality and a long term upward trend, reaching its highest point in the 2017 academic year (22.47 per 10 000 person day). The symptoms of absenteeism were divided into three categories: high incidence in winter and spring (respiratory symptoms, fever and general discomfort, etc.), high incidence in summer (eye symptoms, nosebleeds, etc.) and those without obvious seasonality (skin symptoms, accidental injuries, etc.).The constructed time series models effectively predicted the trend of absenteeism due to illness, although the accuracy of predicting peak intensity was relatively low. Among them, the multi layer perceptron (MLP) model performed the best, with an root mean squared error (RMSE) of 8.96 and an mean absolute error (MAE) of 4.37, reducing 36.51% and 39.02% compared to the baseline model. Conclusion Time series models and machine learning algorithms could effectively predict the trend of sickness absenteeism, and corresponding prevention and control measures can be taken for absenteeism caused by different symptoms during peak periods.

Objective To establish a rat model of Alzheimer's disease (AD) expressing human triple mutant amyloid precursor protein (APP) in the hippocampus, and to provide a model for the study of disease mechanisms and drug development. Methods Twenty-four 12-week-old SPF-grade female SD rats were randomly divided into a blank control group, a virus control group and an experimental group, with eight rats in each group; among them, the experimental group received a stereotaxic injection of adeno-associated virus (AAV) carrying the human triple mutant APP and NanoLuc luciferase genes into the hippocampus. In vivo imaging was used to observe viral expression in the brains of rats in each group, the novel object recognition test was used to assess the recognition memory of the rats in each group, real-time fluorescent quantitative PCR was used to detect the expression level of the APP gene, HE staining was used to examine the brain histopathology, Nissl staining was used to assess the hippocampal lesions, and immunohistochemistry was used to detect the deposition of amyloid β-protein (Aβ). Results In vivo imaging showed that reporter fluorescence was detected in the brains of rats in both experimental and virus control groups. Fluorescence quantitative PCR showed that the expression level of the APP gene was significantly increased in the brains of rats in the experimental group (P<0.01). Novel object recognition test revealed that the recognition memory of rats in the experimental group was significantly reduced compared with that of the blank control group (P<0.01). Six months after recombinant AAV virus infection, HE staining and Nissl staining of brain tissues showed that the number of neurons and Nissl bodies in the CA1 region of the hippocampus in the experimental group was reduced and disorganized; immuno-histochemistry testing of the CA1 region of the hippocampus and the pyramidal cell layer of the experimental group revealed prominent brown deposits, indicating Aβ protein deposition. Conclusion The rat model successfully established by stereotaxic injection and AAV-mediated delivery of human triple mutant APP gene exhibits typical AD features, providing a valuable animal model for studying AD pathology and developing drug therapies targeting Aβ protein deposition.

Objective To establish a rat model of Alzheimer's disease (AD) expressing human triple mutant amyloid precursor protein (APP) in the hippocampus, and to provide a model for the study of disease mechanisms and drug development. Methods Twenty-four 12-week-old SPF-grade female SD rats were randomly divided into a blank control group, a virus control group and an experimental group, with eight rats in each group; among them, the experimental group received a stereotaxic injection of adeno-associated virus (AAV) carrying the human triple mutant APP and NanoLuc luciferase genes into the hippocampus. In vivo imaging was used to observe viral expression in the brains of rats in each group, the novel object recognition test was used to assess the recognition memory of the rats in each group, real-time fluorescent quantitative PCR was used to detect the expression level of the APP gene, HE staining was used to examine the brain histopathology, Nissl staining was used to assess the hippocampal lesions, and immunohistochemistry was used to detect the deposition of amyloid β-protein (Aβ). Results In vivo imaging showed that reporter fluorescence was detected in the brains of rats in both experimental and virus control groups. Fluorescence quantitative PCR showed that the expression level of the APP gene was significantly increased in the brains of rats in the experimental group (P<0.01). Novel object recognition test revealed that the recognition memory of rats in the experimental group was significantly reduced compared with that of the blank control group (P<0.01). Six months after recombinant AAV virus infection, HE staining and Nissl staining of brain tissues showed that the number of neurons and Nissl bodies in the CA1 region of the hippocampus in the experimental group was reduced and disorganized; immuno-histochemistry testing of the CA1 region of the hippocampus and the pyramidal cell layer of the experimental group revealed prominent brown deposits, indicating Aβ protein deposition. Conclusion The rat model successfully established by stereotaxic injection and AAV-mediated delivery of human triple mutant APP gene exhibits typical AD features, providing a valuable animal model for studying AD pathology and developing drug therapies targeting Aβ protein deposition.

Humans ; Amyloidosis ; Amyloid ; Cardiomyopathies

ObjectiveTo investigate the impact of early intervention with Yishen Huazhuo prescription （YHP） on the learning and memory of accelerated aging model mice， as well as its underlying mechanism. MethodForty-eight 3-month-old male SAMP8 mice were randomly assigned into four groups， including the model group， low-dose YHP group， high-dose YHP group， and donepezil group. Additionally， 24 SAMR1 mice of the same age were divided into a control group and a YHP treatment control group， each consisting of 12 mice. The YHP groups received YHP at doses of 6.24 g·kg^-1 and 12.48 g·kg^-1， while the donepezil group was treated with donepezil at a dose of 0.65 mg·kg^-1. The model group and control groups were given physiological saline. The mice were gavaged once daily for a duration of four weeks. Spatial learning and memory abilities of mice were assessed using the Morris water maze test. Immunofluorescence staining was employed to evaluate neuronal density as well as expression levels of M1 microglial （MG） polarization marker inducible nitric oxide synthase （iNOS） and M2 MG polarization marker arginase-1 （Arg-1） in the hippocampus region. Enzyme-linked immunosorbent assay （ELISA） was used to measure serum levels of pro-inflammatory factor interleukin 1β （IL-1β） and anti-inflammatory factor transforming growth factor-β₁ （TGF-β₁）. Furthermore， Western blot analysis was conducted to determine expressions of amyloid β peptide1-42 （Aβ_1-42） along with triggering receptor expressed on myeloid cells 2 （TREM2）/nuclear factor kappa B （NF-κB） signaling pathway-related proteins TREM2， phospho （p）-NF-κB p65， and phospho-inhibitory kappa B kinase β （IKKβ） in the hippocampus. ResultCompared with the control group， the model group exhibited a significantly prolonged escape latency （P<0.01）， a significant reduction in neuron-specific nuclear protein （NeuN） expression in the hippocampus， a significant increase in iNOS expression in MG， and a significant decrease in Arg-1 expression. The serum IL-1β content was significantly increased， while the TGF-β₁ content was significantly decreased. Additionally， there was a significant decrease in TREM2 expression in the hippocampus and significant increases in p-NF-κB p65， p-IKKβ， and Aβ_1-42 expressions （P<0.05， P<0.01）. However， no significant changes were observed in escape latency， times of crossing the platform， and hippocampal NeuN expression in the YHP treatment control group. Conversely， iNOS expression in MG as well as the hippocampal p-NF-κB p65， p-IKKβ， and Aβ_1-42 expressions were significantly decreased. Furthermore， TREM2 expression was significantly increased （P<0.05， P<0.01）. In comparison to the model group， the low-dose YHP group showed a significantly shortened escape latency and an increased number of crossing the platform （P<0.05， P<0.01）. In the high-dose YHP group， the escape latency was significantly shortened （P<0.05）. In the low-dose YHP group， high-dose YHP group， the expression of NeuN in the hippocampus was significantly increased， the expression of iNOS in MG was significantly decreased， and the expression of Arg-l was significantly increased. The serum IL-1β content was significantly decreased， while the TGF-β₁ content was significantly increased. Furthermore， the expression of TREM2 in the hippocampus was significantly increased， and the expressions of p-NF-κB p65， p-IKKβ， and Aβ_1-42 were significantly decreased （P<0.01）. ConclusionEarly YHP intervention may promote the transformation of hippocampal MG from M1 to M2 by regulating the TREM2/NF-κB signaling pathway， reduce the release of neuroinflammatory factors， protect hippocampal neurons， and reduce the deposition of Aβ_1-42， and finally delay the occurrence of learning and memory decline in SAMP8 mice.

Objective: To understand the relationship between stress and Internet addiction among middle school students in Shanghai, so as to provide a scientific basis for promoting students mental health and preventing Internet addiction. Methods: From May to June 2021, a stratified random cluster sampling method was used to select 6 123 middle and high school students in Shanghai for health risk behavior monitoring. Daily Stressors Evaluation Scale for Urban Secondary School Students was used to evaluate students' stress, and the Internet Addiction Test compiled by Young was used to evaluate students Internet addiction. The correlation between student stress and Internet addiction was analyzed by Kruskal-Wallis H test , Chi square test and multiple Logistic regression. Results: Total stress score of middle school students in Shanghai was 24 (12, 39), academic stress score was 8 (5, 13), physical and psychological stress score was 6 (2, 10), interpersonal stress score was 5 (1, 9), and family stress score was 4 (1, 8). The detection rate of Internet addiction was 4.7%. Multivariate Logistic regression analysis showed that the risk of Internet addiction among middle school students with high levels of stress was 8.05 times(95% CI =4.59-14.12) that of students with low levels of stress( P <0.05). The risk of Internet addiction among middle school students with high levels of academic stress, physical and psychological stress, interpersonal stress and family stress was 5.98(95% CI =3.69-9.70), 6.92(95% CI =4.03-11.88), 4.85(95% CI =3.11-7.55), and 4.18(95% CI =2.73-6.40) times that of students with low levels of stress, respectively( P <0.05). Conclusion The academic stress, physical and psychological stress, interpersonal stress, and family stress among middle school students can all lead to an increased risk of Internet addiction.

Objective The study aimed to investigate the impact of rare earth elements(REEs)exposure on pregnancy outcomes of in vitro fertilization-embryo transfer(IVF-ET)by analyzing samples from spouses. Methods A total of 141 couples were included.Blood and follicular fluid from the wives and semen plasma from the husbands,were analyzed for REEs using inductively coupled plasma mass spectrometry(ICP-MS).Spearman's correlation coefficients and the Mann-Whitney U test were used to assess correlations and compare REE concentrations among three types of samples,respectively.Logistic models were utilized to estimate the individual REE effect on IVF-ET outcomes,while BKMR and WQS models explored the mixture of REE interaction effects on IVF-ET outcomes. Results Higher La concentration in semen(median 0.089 ng/mL,P=0.03)was associated with a lower fertilization rate.However,this effect was not observed after artificial selection intervention through intracytoplasmic sperm injection(ICSI)(P=0.27).In semen,the REEs mixture did not exhibit any significant association with clinical pregnancy. Conclusion Our study revealed a potential association between high La exposure in semen and a decline in fertilization rate,but not clinical pregnancy rate.This is the first to report REEs concentrations in follicular fluid with La,Ce,Pr,and Nd found at significantly lower concentrations than in serum,suggesting that these four REEs may not accumulate in the female reproductive system.However,at the current exposure levels,mixed REEs exposure did not exhibit reproductive toxicity.

Objective: To explore the association between dietary behaviors and sleep duration among middle school students in Shanghai, so as to provide reference for interventions targeting insufficient sleep. Methods: From May to June 2021, a stratified cluster random sampling method was employed to select a sample of 10-17yearold middle school students for monitoring their healthrisk behaviors. A total of 5 538 valid questionnaires were collected. The survey included items such as daily sleep duration, weekly consumption of sugary beverages, freshly squeezed fruit juice, fresh fruits, fresh vegetables, fried foods, milk and yogurt, breakfast habits, and frequency of eating outside. Statistical analysis was conducted using Chisquare test, Wilcoxon ranksum test, and multivariable Logistic regression model. Results: About 73.7% of middle school students reported insufficient sleep in Shanghai. There was a positive correlation between the average daily consumption of fresh fruits and breakfast consumption with sleep duration. In other words, a higher frequency of consuming fresh fruits (OR=1.29) and eating breakfast (OR=1.07) were associated with a higher likelihood of sufficient sleep. Conversely, there was a negative correlation between the frequency of consuming desserts (OR=0.78) and fried foods (OR=0.88) and sleep duration (P<0.05). Conclusions Increasing the consumption of fresh fruits and maintaining regular breakfast habits while reducing the intake of fried foods can contribute to achieving sufficient sleep among middle school students. When implementing interventions to improve sleep among middle school students, promoting healthy and balanced diets can be considered as one of the intervention strategies.

[Objective] To establish a real-time fluorescence quantitative PCR nucleic acid detection method of human parvovirus B19 and validate the method systematically. [Methods] Specific primers and probes for the highly conserved regions of the three genotypes of B19 virus were designed, and B19 quantitative amplification standard curves were established. The accuracy, precision (repeatability and intermediate precision), linear range, quantification limit, detection limit, specificity, anti cross contamination, genotyping and anti-interference ability of this method were verified. [Results] When the quantitative reference range for B19 virus was 2.0×10¹ to 1.0×10⁸ IU/mL, a double logarithmic regression analysis was performed between the measured values and the theoretical values, and the regression equation R²≥0.98 showed good linear correlation. The quantification limit was 20 IU/mL, with a detection rate of 100%. The detection limit was 10 IU/mL, and the detection rate is 95.23%. Three genotypes of B19 virus samples can be effectively detected. The plasma of seven non B19 pathogens, including hepatitis A virus, hepatitis B virus, hepatitis C virus, human immuno-deficiency virus, human cytomegalovirus, hepatitis E virus and Treponema pallidum, was non reactive and has good species specificity. Simultaneously, in the presence of seven other concurrent pathogens, positive samples with a weak positive concentration of E3 IU/mL could be stably detected, and the B19 nucleic acid testing method was not interfered with. When the hemoglobin concentration was 431 mg/dL, triglycerides (1 269 turbidity) and unconjugated bilirubin concentration was 20 mg/dL, this method was non reactive for all three common plasma interfering substances. In the presence of three common plasma interfering substances, positive samples with a weak positive concentration of E3 IU/mL could be stably detected, and the B19 nucleic acid testing method was not interfered with. The deviation between the detection values of standard substances at two concentration levels of S1 (E5 IU/mL) and S2 (E4 IU/mL) and the target values were≤±0.5 log value. The CV values of positive sample 1 (concentration level E5 IU/mL) and positive sample 2 (concentration level E4 IU/mL) for daily precision confirmation and continuous 5-day intra-day precision confirmation were both≤5%. [Conclusion] This method has strong specificity, high sensitivity, wide linear range, stability, reliability and high accuracy, and can be used for the detection of human parvovirus B19 nucleic acid in plasma.

Objective:To investigate the pollution levels and influencing factors of polybrominated diphenyl ethers (PBDEs) in household dust in five cities in northern China.Methods:Based on the "Chinese Indoor Environment and Health Surveillance" project carried out by the National Institute of Environmental Health, Chinese Center for Disease Control and Prevention in 2018-2019, during the warm season (April 2018 to September 2018) and the cold season (November 2018 to March 2019), Lanzhou in Northwest China, Shijiazhuang in North China, Panjin in Northeast China, Luoyang in Central China, and Qingdao in East China were selected as the research sites. A total of 87 families were recruited to study residences in real-life scenarios. At the same time, dust samples were collected to detect the concentration of PBDEs. The level of household environmental indicators was measured, and the residential building characteristics and family behavior habits were collected through questionnaires. A total of 142 valid dust samples and 140 valid questionnaires were obtained. The differences in PBDE concentrations across seasons, wind zones, residential building characteristics, and family habits were analyzed. The exploratory factor analysis was performed to investigate the possible sources of PBDEs, and multivariate linear regression was used to explore the factors influencing PBDEs in household dust.Results:The M ( Q1,Q3) of total PBDE concentrations in 142 household dust samples in five cities was 144.51 (106.61, 222.65) ng/g in the warm season and 145.10 (98.57, 180.65) ng/g in the cold season, respectively. There were seasonal differences in the concentration of ∑ 12PBDEs in Luoyang and Shijiazhuang ( P<0.01). The concentration of BDE-71 was highest among PBDE homologues, followed by BDE-66 and BDE-47. Three factors were extracted by exploratory factor analysis in the warm season, and the cumulative variance contribution rate was 67.90%. The multivariate linear regression showed that the house completion less than ten years [ β (95% CI): 0.186 (0.013, 0.359)], infrequent home cooking [ β (95% CI):-0.342 (-0.570, -0.114)], and increased residential PM 10 concentration [ β (95% CI): 0.001 (0.000, 0.002)] during the warm season, as well as the house far from driveway [ β (95% CI): 0.093 (0.013, 0.172)], house area less than 90 m 2 [ β (95% CI):-0.138 (-0.264, -0.013)], and lower residential xylene concentration [ β (95% CI):-0.006 (-0.011, -0.001)] during the cold season might be related to the elevated concentrations of ∑ 12PBDEs in household dust. Conclusion:The pollution of PBDEs in household dust in five northern cities is at a medium to high level. Years of house completion, frequency of cooking at home, residential PM 10 concentration, distance from house to driveway, house area, and residential xylene concentration may influence household PBDE concentrations.