Early childhood caries and related risk factors: A cross-sectional study of children in Zhejiang Province, China.

OBJECTIVES: This work aims to exploring the risk factors related to ECC by investigating oral health status, related behaviours and habits of children and their parent's knowledge regarding oral hygiene. METHOD: A total of 2700 children aged 3-5 years and their parents from Zhejiang province were examined. Chi-square test or U test was used to analyse the difference of caries incidence among different groups. Logistic multiple factor stepwise regression model was used to analyse the risk factors influencing ECC prevalence. RESULTS: ECC prevalence rate in these children was 70.7%. The mean decayed missing filled teeth(dmft) scores were 4.33. Through analysis of logistic multiple factor stepwise regression model, risk factors related to the prevalence of ECC in children include: older age, region (coastal or mountainous area), higher frequency of bedtime dessert consumption and poor care of children's oral health by parents. In the questionnaire, 5 of 14 questions showed parents' poor oral knowledge or awareness. CONCLUSION: The prevalence rate of ECC in children aged 3-5 in this study was high and associated with older age, region (coastal or mountainous area), higher frequency of bedtime dessert consumption and poor care of children's oral health. Parents need to strengthen their understanding and action of dental caries.

Related Risk Factors of Early Childhood Caries in Zhejiang Province, China During the COVID-19 Pandemic.

Objectives: This work aims to examining the latest early childhood caries situation in children aged 3 and 5 and its related risk factors in Zhejiang Province during the COVID-19 pandemic. Method: There are 3,537 children and their main caregivers participate in this study. We used chi square test or U-test to analyze whether there were differences in the prevalence of dental caries under different variables. The risk factors on ECC were determined by multivariate logistic analysis. Results: The ECC rate of children in this study was 57.51%. The mean decayed missing filled teeth (dmft) scores were 3.01. The result of multivariate logistic analysis showed higher ECC prevalence was found in children as age increasing, with lower district economic level, with high frequency of confectionary consumption, having oral medical treatment behavior and bad evaluation of children's oral health by parents. Conclusion: In general, the prevalence rate of ECC in this study was lower than five years ago, but still higher than those developed countries. And it was associated with age, district economic level, frequency of confectionary consumption, oral medical treatment behavior and evaluation of children's oral health by parents.

Preparation and characterization of vanillin-chitosan Schiff base zinc complex for a novel Zn2+ sustained released system.

In this work, a novel sustained released system (VCSB-Zn(II)) for zinc supplements was built by vanillin-chitosan Schiff base (VCSB) chelated with Zn2+ to improve the zinc trace element utilization ratio. Samples were characterized by FT-IR, 1H NMR, XRD, SEM, and TGA. The results showed that VCSB exhibited a more excellent chelation capacity of Zn2+ than chitosan. The chelation capacity of VCSB was about 1.7 times more than that of chitosan, corresponding to 50.96 mg/g and 29.91 mg/g, respectively. Furthermore, VCSB-Zn(II) showed excellent sustained released performance at simulated gastric fluid because of the acid slow-dissolving ability. And the higher the CN content of VCSB, the higher the cumulative release rate (Ri) of Zn2+, the highest Ri reached 77.81%. The sustained released curves were described by the first-order and Korsmeyer-Peppas equation, which described the Zn2+ sustained released performance caused by the dissolution of VCSB-Zn(II) and Fick diffusion. This Zn2+ sustained released system shows great potential in the application in the field of trace elements supplements for animals.

Theoretical investigation into the influence of molar ratio on mixture system: α, γ, δ-HMX molecules coexisting with ß-HMX crystal.

Molecular dynamics (MD) simulation was conducted to research the effect of molar ratios for α/ß-HMX, γ/ß-HMX, and δ/ß-HMX(octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) mixture systems on thermal stability, sensitivity, and mechanical properties of explosives, and the computing models were established by Materials Studio (MS). The binding energies, the maximum trigger bond length (LN-NO2), cohesive energy density as well as mechanical properties of the mixture systems and the pure ß-HMX crystal were obtained and contrasted. The results demonstrate that the molar ratios have great influence on the binding capacity of molecules between α, γ, δ-HMX, and ß-HMX in the mixture systems. The binding energies decrease with the increase of molecular molar ratio and have the maximum values at the 1:1 M ratio. The maximum trigger bond length does not change apparently after mixing, while the cohesive energy density (CED) increases as the molar ratio increases but are all smaller than the pure ß-HMX crystal, demonstrating that the sensitivity of the mixture systems increases. The mechanical properties decrease after mixture, which illustrates that the mechanical properties of the pure crystal are superior to the mixture systems.

Metallic Fabrics as the Current Collector for High-Performance Graphene-Based Flexible Solid-State Supercapacitor.

Flexible solid-state supercapacitors attract more and more attention as the power supply for wearable electronics. To fabricate such devices, the flexible and economical current collectors are needed. In this paper, we report the stainless steel fabrics as the current collector for high-performance graphene-based supercapacitors. The stainless steel fabrics have superior properties compared with the widely used flexible current collectors. The flexible supercapacitors show large specific capacitance of 180.4 mF/cm(2), and capacitance retention of 96.8% after 7500 charge-discharge cycles. Furthermore, 96.4% of the capacitance is retained after 800 repeating stretching-bending cycles. The high performance is related to the excellent conductivity, good mechanical flexibility, and high electrochemical stability of the stainless steel fabrics. The achievement of such high-performance and flexible supercapacitor can open up exciting opportunities for wearable electronics and energy storage applications.

Formation of He-Rich Layers Observed by Neutron Reflectometry in the He-Ion-Irradiated Cr/W Multilayers: Effects of Cr/W Interfaces on the He-Trapping Behavior.

Cr/W multilayer nanocomposites were presented in the paper as potential candidate materials for the plasma facing components in fusion reactors. We used neutron reflectometry to measure the depth profile of helium in the multienergy He ions irradiated [Cr/W (50 nm)]3 multilayers. Results showed that He-rich layers with low neutron scattering potential energy form at the Cr/W interfaces, which is in great agreement with previous modeling results of other multilayers. This phenomenon provided a strong evidence for the He trapping effects of Cr/W interfaces and implied the possibility of using the Cr/W multilayer nanocomposites as great He-tolerant plasma facing materials.