Effect of Multiple Coatings of One-step Self-etching Adhesive on Microtensile Bond Strength to Primary Dentin

Objective To investigate the effect of multiple coatings of the one-step self-etching adhesive on immediate microtensile bond strength to primary dentin.Methods Twelve caries-free human primary molars were randomly divided into 2 groups with 6 teeth each.In group 1,each tooth was hemisected into two halves.One half was assigned to control subgroup 1,which was bonded with a single-step self-etching adhesive according to the manufacturer's instructions;the other half was assigned to experimental subgroup 1 in which the adhesive was applied three times before light curing.In group 2,the teeth were also hemisected into two halves.One half was assigned to control subgroup 2,which was bonded with the single-step self-etching adhesive according to the manufacturer's instructions;the other half was assigned to experimental subgroup 2 in which three layers of adhesive were applied with light curing each successive layer.Microtensile bond strength was immediately tested after specimen preparation.Results When the adhesive was applied three times before light curing,the bond strength of the experimental subgroup 1(n=33,57.49±11.61 MPa) was higher than that of the control subgroup 1(n=31,49.71±11.43 MPa,P<0.05).When using the technique of applying multiple layers of adhesive with light curing each successive layer,no difference of immediate bond strength was observed between the control subgroup 2 and the experimental subgroup 2(P>0.05).Conclusion Multiple coatings of one-step self-etching adhesive can increase the immediate bond strength to primary dentin when using the technique of light-curing after applying three layers of adhesive.

Projected heat wave increasing trends over China based on combined dynamical and multiple statistical downscaling methods

Extensive investigations on the projection of heat waves(HWs)were conducted on the basis of coarse-resolution global climate models(GCMs).However,these investigations still fail to characterise the future changes in HWs regionally over China.PRECIS dynamical downscaling with a horizontal resolution of 25 km×25 km was employed on the basis of GCM-HadCM3 to provide reliable projections on HWs over the Chinese mainland,and six statistical downscaling methods were used for bias correction under RCP4.5 and RCP8.5 scenarios.The multi-method ensemble(MME)of the top three dynamical downscaling methods with good performance was used to project future changes.Results showed that PRECIS primarily replicated the detailed spatiotemporal pattern of HWs.However,PRECIS overestimated the HWs in the Northwest and Southeast and expanded the areas of HWs in the Northeast and Southwest.Three statistical downscaling methods(quantile mapping,CDF-t and quantile delta mapping)demonstrated good performance in improving PRECIS simulation for reproducing HWs.By contrast,parametric-based trend-preserving approaches such as scaled distribution mapping and ISI-MIP are outperformed by the three aforementioned methods in downscaling HWs,particularly in the high latitudes of China.Based on MME projections,at the end of the 21st century,the national average of the number of HW days each year,the length of the longest HW event in the year and the extreme maximum temperature in HW will increase by 3 times,1 time and 1.3℃,respectively,under the RCP4.5 scenario,whilst that under the RCP8.5 scenario will increase by 8 times,3 times and 3.7℃,respectively,relative to 1986-2005.The Northwest is regionally projected to suffer long and hot HWs,whilst the South and Southeast will experience frequent consecutive HWs.Thus,HWs projected by the combined dynamical and statistical downscaling method are highly reliable in projecting HWs over China.

Exploring atmospheric environmental drivers of asthma among children in Shanghai, China: Evidence-informed policies are required

It is important to identify atmospheric environmental drivers of childhood asthma because asthma is the most common chronic disease in children globally.We provided an overview of the impacts of exposure to atmospheric environmental factors(e.g.,meteorological factors and air pollutants)on childhood asthma,based on a series of studies with the cutting-edge environmental epidemiological methodology in Shanghai,China.Overall,we found that the prevalence of asthma among the children aged 3–7 years had increased by approximately 7 fold,from 2.1%in 1990 to 14.6%in 2019.Most meteorological factors(i.e.daily mean temperature,temperature difference,air pressure,air pressure difference,precipitation,relative humidity,sunshine and wind speed)and air pollutants(PM10,PM2.5,NO2,SO2 and O3)were significantly associated with childhood asthma(p<0.05),but meteorological factors appeared to play more important roles than air pollutants in the occurrence of asthma exacerbations.We also found that temperature variability was significantly associated with the elevated relative risk of daily outpatient visits for childhood asthma(p<0.05).Furthermore,we conducted a systematic review on climate change adaptation measures and childhood asthma and found that there were a number of adaptation measures proposed for childhood asthma in response to climate change,including vulnerability assessment,improving ventilation and heating,enhancing community education,developing forecast models,and early warning systems.However,the effectiveness of most adaptation measures,except for improving ventilation and heating in winter,have not been explored and quantified.Since asthma is sensitive to the variation of atmospheric environmental conditions,it is critical to develop and implement appropriate climate change mitigation and adaptation strategies as global heating becomes apparent.

Increasing prevalence and influencing factors of childhood asthma: a cross-sectional study in Shanghai, China

Background Asthma has been a global problem,especially in children.We aim to evaluate the contemporary prevalence and influencing factors of asthma among children aged 3–7 years in Shanghai,China.Methods A random sample of preschool children was included in this study.The International Study of Asthma and Allergies in Childhood questionnaire was adopted to assess the childhood asthma.Multivariable logistic regression models were used to evaluate the associations between independent variables and childhood asthma.Results Of 6389 preschool children who were invited to take part in this study,6163(response rate:96.5%)completed the questionnaire and were included in the analysis.The overall prevalence of asthma was 14.6%which increased more than six folds from 2.1%in 1990.Being male,younger age,preterm delivery,being born in spring or autumn,being delivered by elective cesarean section without indication,miscarriage,high socioeconomic status,having allergy history,and exposure to passive smoking,latex paint,and dust were potential risk factors for childhood asthma.Spending more time outdoors(>30 min/day),having indoor plants,and cleaning rooms more frequently were potential protective factors.Conclusions The prevalence of childhood asthma in Shanghai has increased dramatically during the past three decades.The findings about risk and protective factors of childhood asthma could be used to develop appropriate strategies to prevent and control childhood asthma in Shanghai and in other similar metropolitan cities.

Translational plasma stomatology:applications of cold atmospheric plasmas in dentistry and their extension

In recent years,translational plasma medicine(TPM),as a novel application area of plasmas,has attracted much attention of experts from both academic and clinical fields.State-of-the-art of the lab-scale research and clinical trials of the cold atmospheric plasmas(CAPs)in the stomatology are reviewed in detail from the direct and indirect applications of the CAPs.Based on the discussions concerning the relationship between the plasma stomatology and the plasma medicine,it is indicated that it would be an important reference for promoting the TPM starting from the fundamental and application studies in the field of dentistry,which is also one of the most three promising application fields of plasma medicine.