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.

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.

Objective:To construct a systematic, standardized, scientific and effective evaluation index system for standardized training of newly recruited nurses.Methods:By the literature review, applying the Delphi method and purpose sampling to conduct two rounds of expert consultations to 17 nursing experts from 5 medical units and 1 nursing school from October 2019 to April 2020 to construct the evaluation index system for standardized training of newly recruited nurses.Results:The recovery rates of the two rounds of expert consultation questionnaires were all 100%, and the expert authority coefficient was 0.92. The final evaluation index system for standardized training of newly recruited nurses included 4 first-level indicators (professional literacy, theoretical knowledge, nursing operation skills, and core competency of the post) , 17 second-level indicators, and 52 third-level indicators.Conclusions:The evaluation index system for standardized training of newly recruited nurses established in this study is systematic, scientific and effective, which can provide a reference for standardized training and evaluation of newly recruited nurses, and provide a theoretical basis and practical guidance for improving the training effect and quality.

Objective: To explore the effects of ApoE epsilon4 (ApoE-ε4) alleles on cognitive function and resting-state functional MRI (rs-fMRI) in patients with amnestic mild cognitive impairment(aMCI) based on a prospective cohort study. Methods: An average of 20 months of prospective observations were conducted on 16 ApoE-ε4-carriers and 24 non-carriers of aMCI. Neuropsychological assessments and rs-fMRI data were collected at both baseline and follow-up. All participants were assessed by a battery of neuropsychological tests and underwent rs-fMRI. Two core regions of the default mode network (DMN), the left posterior cingulate cortex (PCC) and the medial prefrontal cortex (mPFC), were selected as seeds to calculate the functional connectivity. Two-way repeated measures analysis of variance was used to assess the effects of ApoE genotype(ε4-carriers, nonε4-carriers), interval and the interaction between these two factors for functional connectivity extracted from changed region found by t-test.Conversion rates of dementia were compared between ApoE-ε4-carriers and nonε4-carriers at follow-up using Chi-square test. For the comparison of functional connectivity and clinical data between ApoE-ε4-carriers and nonsε4-carriers in baseline and follow-up, the normal distribution test was carried out first. If the normal distribution was fitted, the two-sample t test was used, otherwise, the Mann-Whitney rank sum test was used. Finally, the general linear model was used to assess the relationships between alterations in functional connectivity and in neuropsychological assessments as well as the interaction effect. Results: (1)Significant decline in memory domains were found in ApoE-ε4-carriers as compared to non-carriers at both baseline and follow-up. The ApoE-ε4-carriers (14/16) presented a higher conversation rate than non-carriers(13/24, χ²=4.862, P=0.027) at follow-up. (2)Functional imaging analysis revealed that ApoE-ε4-carriers exhibited significantly higher functional connectivity between the left PCC and the left angular (ApoE-ε4-carriers: 0.23±0.11, non-carriers: -0.03±0.13, t=4.800, cluster size: 1 944 mm³, P=0.004), and between the left mPFC and the left angular (ApoE-ε4-carriers: 0.33±0.21, non-carriers: 0.08±0.18, t=5.040, cluster size:1 836 mm³, P=0.006) as compared to non-carriers at follow-up. We detected significant effect for the interaction interval by ApoE-ε4 on functional connectivity between the left angular and the left PCC (F=10.833, P=0.002)as well as the left mPFC (F=7.280, P=0.010). (3)The alteration of functional connectivity value between the left mPFC and the left angular in ApoE-ε4-carriers was positively correlated with the changes ofimmediate memory (r=0.692, P=0.018). The correlation was not statistically significant in ApoE-ε4-noncarriers (r=-0.198, P=0.417) and the integration effect was significant (F=8.632, P=0.006). Conclusions The ApoE-ε4 actually accelerates the deterioration of cognitive function in aMCI patients and carriers presented relatively reserved functional connectivity between the left angular and other core regions within DMN, which indicated the disruption of functional connectivity may be one of the underline mechanisms of ApoE-ε4 during AD process.

Alzheimer′s disease (AD) is an incurable disease in the field of major chronic diseases. Subjective cognitive decline (SCD) is a clinical risk factor for AD. The standardized screening and intervention in individuals with SCD are of great importance in early prevention and treatment of AD. According to the clinical criteria proposed by The characterisation of subjective cognitive decline, which was published online in Lancet Neurology, the article summarized the definition of SCD, the latest perspective of clinical standards in SCD, and the results of AD preclinical SCD research. The purpose of this work was to provide concrete guidance and recommendations for making clinical decisions in diagnosis and scientific research on SCD.

Objective We utilized a joint independent component analysis (Joint ICA), a novel method that combined rs?fMRI and DTI information, to describe comprehensive characteristics of brain functional activities and microstructural changes in the continuum of AD. Methods We employed a Joint ICA to calculate ALFF maps of fMRI data and FA maps of DTI data and fuse them in healthy controls (n=68), SCD (n=35), amnesic MCI (n=47) and AD (n=31). Besides, we applied one way ANOVA to detect the significant differences of joint components among groups, while controlling the age, gender, education, head motion, volumes of gray matter, white matter and CSF. Partial correlation analysis was used to test the relationships between joint ICs and cognitive measures. Results The results showed that there was no inner?group difference in HC and SCD groups (F=14.16, P<0.05). Compared to HC, SCD and AD groups, the ALFF component of aMCI group showed higher values in the bilateral cerebellum, bilateral precuneus, bilateral angular gyrus, bilateral frontal gyrus, bilateral temporal areas, thalamus and left insula. And in these regions, the ALFF of AD group was lower than HC. For the FA component map, same differences were found in the corpus callosum and limbic system. Furthermore, positive partial correlation between the IC weights and Mini?Mental State Examination (MMSE) scores was also found (r=0.29, P<0.01). Conclusions Multi?modal evaluation of AD has been implemented by using Joint ICA analysis of fMRI?DTI, which would contribute to early prediction, diagnosis, and even effective intervention in AD. These findings could help to explain the underlying mechanism of the disease progression.

Objective To study the changes and mechanism of the function of islet βcells and insulin signal transduction molecules in rats after long-term period lipid infusion.Methods Thirty SpragueDawley (SD) rats were randomly divided into free fatty acid (FFA) and normal saline (NS) groups.Catheters were implanted under pentobarbital anesthesia in the right atrium via the jugular vein and the left carotid artery.A technique for a 72-h infusion in unrestrained rats was used for triglyceride and heparin or saline infusion.The infusion period was started on day 2 after surgery.After 72-h infusion,fasting serum insulin (Ins) and FFA in the blood were determined.The glucose infusion rat (GIR) was measured by hyperinsulinemia euglycemic clamp to evaluate the peripheral insulin resistance.The intravenous glucose tolerance test (ivgtt) and islet cell perifusion was conducted to evaluate the function of islet β-cell.The rats in two groups were sacrificed,and the pancreatic islets were isolated and collected.The levels of malondialdehyde (MDA) and reduced glutathione hormone (GSH) were detected in pancreatic tissues.The expressions of insulin receptor substrate-1 (IRS-1),insulin receptor substrate-2 (IRS-2),and glucose transporter-2 (Glut2)gene in islets were detected by real-time polymerase chain reaction (PCR).Results (1)The serum FFA concentration in the FFA group was higher than in NS group [(1.56 ± 0.21) mmol/L vs (0.65 ± 0.12)mmol/L,P ＜0.01].(2)The GIR was decreased significantly in FFA group compared with NS group(P ＜0.01).(3)The glucose that stimulated insulin secretion was decreased in the FFA group.(4)The levels of MDA were significantly higher in FFA group [(1.62 ± O.18) mmol/mg prot vs (0.76 ± 0.15) mmol/mg prot,P ＜0.01].The levels of GSH were lower in FFA group [(22.54 ±2.66) mg/g prot vs (36.58 ± 3.02) mg/g prot,P ＜ 0.01].(5) The gene cxprcssion of IRS-1 in islets was significantly decreased by [(36.8±1.8)％,P ＜0.01],and the expression of IRS-2 and Glut-2 was decreased by [(29.6±1.2) ％] and [(58.7 ± 2.1) ％] in FFA group,respectively(all P ＜0.01).Conclusions Lipid infusion in long time decreased the secretion of insulin and impaired the expression of insulin signal transduction molecules in islet βcells.

Objective To establish an animal model of PCOS and to detect the DNA methylation states of LHR, INSR and AR genes. Methods 24-days-old female Sprague-Dawley (SD) rats were randomly divided into two groups. The rats in the experimental group were given subcutaneous implanting of levonorgestrel silica gel staff and injected 1.5 IU hCG twice daily for 9 days from the 4th day. The rats in the control group were injected with normal saline at the same time. Ovarian morphologic changes, sex hormone levels, fasting serum insulin and glucose were detected. The LHR, INSR and AR genes' DNA methylation patterns were checked by methylation specific PCR in modeling group and control group. Results The ovarian weight and volume in modeling group were higher than those in control group. The ovaries in modeling group showed multiple follicular cysts, and the number of theca cells and interstitial cells increased. Less developed follicles and corpus lutea were seem. The serum level of progesterone, testosterone, luteinizing hormone, fasting insulin and glucose were significantly higher in experimental group than those in control group, so as the LH/FSH ratio and HOMA index. No methylation of LHR and AR genes were found in both groups. The methylation frequency of INSR gene (76.7%) was significantly higher in modeling group than that in control group (P<0. 001). Conclusion The depression of INSR gene's transcriptional induced by DNA methylation is important in the development of insulin resistance in PCOS.

The perivascular epithelioid cell (PEC) is a cell type constantly present in a group of tumors called PEComas(perivascular epithelioid cell tumors). PEC expresses myogenic and melanocytic markers,such as HMB45. PEComa is a widely accepted entity now. PEComas are related to the genetic alterations of tuberous sclerosis complex (TSC), an autosomal dominant genetic disease due to losses of TSC1 or TSC2 genes. PEComas are rare in the urinary system and there are some open questions about PEComas regarding its histogenesis, the definition of epithelioid angiomyolipoma and the identification of the histological criteria of malignancy. This review provides an update on PEComas of the urinary system.

Pancreatic stellate cell (PSC) activation in islet fibrosis of insulin-resistant rats induced by high-fat diet was investigated. After 20 weeks, the glucose infusion rate and glucose-stimulated insulin secretion in high-fat group were significantly decreased while fasting plasma glucose, fasting serum insulin, free fatty acid and the basal glucagon secretion were significantly increased compared with those parameters of the control rats (P< 0.05 or P<0.01). Activated PSC and collagen fiber ( type Ⅰ and Ⅲ) were found in islets of rats fed with high-fat. The result suggests that PSC activation, proliferation and migration to islet may contribute to islet fibrosis in insulin-resistant rats.