BackgroundDental fear and anxiety (DFA) is a major issue affecting children’s oral health and clinical management. This study investigates the association between children’s DFA and family related factors, including parents’ DFA, parenting styles, family structure (nuclear or single-parent family), and presence of siblings.MethodsA total of 405 children (9–13 years old) and their parents were recruited from 3 elementary schools in Hong Kong. Child’s demographic and family-related information was collected through a questionnaire. Parents’ and child’s DFA were measured by using the Corah Dental Anxiety Scale (CDAS) and Children Fear Survey Schedule-Dental Subscale (CFSS–DS), respectively. Parenting styles were gauged by using the Parent Authority Questionnaire (PAQ).ResultsDFA was reported by 33.1% of children. The mean (SD) CFSS-DS score was 29.1 (11.0). Children with siblings tended to report DFA (37.0% vs. 24.1%; p = 0.034) and had a higher CFSS-DS score (29.9 vs. 27.4; p = 0.025) as compared with their counterpart. Children from single-parent families had lower CFSS-DS score as compared with children from nuclear families (β = − 9.177; p = 0.029). Subgroup analysis showed a higher CFSS-DS score among boys with siblings (β = 7.130; p = 0.010) as compared with their counterpart; girls’ from single-parent families had a lower CFSS-DS score (β = − 13.933; p = 0.015) as compared with girls from nuclear families. Children’s DFA was not associated with parents’ DFA or parenting styles (p > 0.05).ConclusionsFamily structure (nuclear or single-parent family) and presence of siblings are significant determinants for children’s DFA. Parental DFA and parenting style do not affect children’s DFA significantly.Electronic supplementary materialThe online version of this article (10.1186/s12903-018-0553-z) contains supplementary material, which is available to authorized users.

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Large‐scale growth of highly crystalline single layer 2D polymers (SL‐2DPs) and their subsequent integration into memristors is key to advancing the development of high‐density data storage devices. However, leakage problems resulting from the porous structure of 2DPs continue to make such advances extremely challenging. Herein, we overcome this issue by incorporating long alkoxy chains into key molecular building blocks to obtain a highly crystalline 2DP, as visualized by scanning tunneling microscopy, and prevent metal permeation in the subsequent device fabrication process. SL‐2DP memristors constructed via direct evaporation of the top electrodes exhibit low variability (σVset = 0.14) due to the single‐monomer‐thick feature together with the high regular structure and coordination ability which minimizes the stochastic spatial distribution of conductive filaments (CFs) in both vertical and lateral dimensions. The variability is further decreased to 0.04 by confining the formation and fracture of CFs to the interface through the utilization of bilayer junctions. Using peak force tunneling atomic force microscopy, the nanometer scalability (< 50 nm2) and low power consumption of these molecular memristor devices are demonstrated.

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Objective To investigate the association between single nucleotide polymorphisms (SNPs) in six candidate genes (enamelin [ ENAM]; tuftelin 1 [ TUFT1]; matrix metallopeptidase 13 [ MMP13]; interleukin 1 beta [ IL1B]; interleukin 10 [ IL10]; interleukin 1 receptor antagonist [ IL1RN]) and dental caries in children from northwest China. Methods This case–control study enrolled children (12–15 years) who underwent routine dental examinations. The children were divided into two groups based on the presence of dental caries. A saliva sample was collected and seven SNPs (rs3806804A/G in ENAM, rs3811411T/G in TUFT1, rs2252070A/G and rs597315A/T in MMP13, rs1143627C/T in IL1B, rs1800872A/C in IL10 and rs956730G/A in IL1RN) were genotyped. Results A total of 357 children were enrolled in the study: 161 with dental caries and 196 without dental caries. No significant difference was found in the alleles and genotypes of five genes ( ENAM, TUFT1, MMP13, IL10 and IL1RN) between those with and without dental caries. A significant relationship was found between the IL1B rs1143627C/T polymorphism and dental caries susceptibility with those carrying the rs1143627CT genotype having a lower risk of dental caries compared with those carrying the CC genotype (odds ratio 0.557; 95% confidence interval 0.326, 0.952). Conclusion The IL1B rs1143627C/T polymorphism may be associated with dental caries susceptibility in children from northwest China.

This study reconstructs 6 hourly significant wave heights (H s ) in the South and East China Seas for the period 1871-2010, using the Twentieth Century Reanalysis ensemble of mean sea level pressure (SLP) fields and a multivariate regression model to represent the H s -SLP relationship in each study area. The regression model was calibrated and validated using the ERA-Interim reanalysis of H s and SLP for the period 1981-2010. These reconstructions were found to reproduce reasonably well the seasonal mean and maximum H s climates as represented by the ERA40 and ERA-Interim wave reanalyses. For each study area, an ensemble of 56 members of 6 hourly H s was reconstructed for each grid point. The regional mean series of the ensemble mean of the reconstructed consecutive monthly mean H s was tested for temporal homogeneity, which identified a few discontinuities in the pre-1946 period and led to the exclusion of the reconstructed H s for 1871-1910 from trend analysis (due to data uncertainty and inhomogeneity). Each 6 hourly H s time series for the period 1911-2010 was homogenized for the identified discontinuities, before being used to derive annual and seasonal mean and maximum H s for trend analysis. The trend analysis results show that, in both study areas, the 1911-2010 wave height trends are dominantly negative, with the exception that the seasonal maximum significant wave heights seem to have increased in summer and spring in the central South China Sea and in summer in the East China Sea.