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Objective@#To evaluate water sorption and hygroscopic dimensional changes of five core buildup composite resins, and to provide references for material modification on water sorption.@*Methods@#Five commercial core buildup materials (group A: Smart Dentin ReplacementTM; group B: NanoFil; group C: ParaCoreTM; group D: LuxaCore Z; group E: EmbraceCoreTM Resin Cement) were fabricated to disk-shaped specimens: (15.0±0.1) mm diameter, (2.0±0.1) mm thickness (n=10). Specimens were thoroughly irradiated with curing lights. The initial mass in air was recorded, and the initial mass in deionized water was recorded. Five specimens of each group were immersed in deionized water for 28 d. They were weighed as a function of different immersion time (1, 2, 3, 4, 5, 6, 7, 14, 28 d). The mass in air was recorded, and the displayed mass in deionized water was recorded. Archimedes' principle was applied to calculate the dimensional changes. The other five specimens of each group were stored in artificial saliva and were tested by the same methods.@*Results@#All specimens gained weight and hygroscopic changes during 28 d immersion. When stored in deionized water, the apparent mass change of group A [(10.6±0.9) μg/mm3] and the dimensional change of group A [(0.39±0.10)%] were the lowest, while the mass change of group E [(48.0±0.2) μg/mm3] and the dimensional change of group E [(3.16±0.13)%] were the highest (P<0.05). In artificial saliva, the lowest apparent mass change was found in group A [(11.8±1.0) μg/mm3] while the highest change was found in group E [(47.4±3.5) μg/mm3] (P<0.05). The lowest dimensional change was found in group C [(0.37±0.09)%] and the highest was found in group E [(3.07±0.19)%] in artificial saliva (P<0.05).@*Conclusions@#Water sorption and dimensional changes vary in immersion fluids with different osmotic pressure. Water sorption and dimensional changes of core buildup composite resins are highly correlated with test materials in both of the deionized water and artificial saliva.
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ObjectiveTo observe the lung injury of rats caused by PM2.5 induced imbalance of TH17/Treg immune system and the intervention effect of two different TCM treatments.Methods Wistar male rats were randomly divided into normal group, model group, TCM-treated group1 and TCM-treated group 2. PM2.5-induced lung injury model was established by airway instillation. Model group was given normal saline for gavage. TCM- treated group 1 and 2 were given Yupingfeng Powder and Guomin Decoction combined with Zhisou Powder for gavage. The pathological changes of bronchial and lung tissues, the contents of IL-8, IL-10, IL-17, NE, and MUC5AC in serum and BALF were compared, and the expressions of Foxp3 and IL-17 in lung tissue of each group were analyzed.Results Compared with normal group, the contents of IL-8, IL-17, NE and MUC5AC in serum and BALF of model group increased significantly, while IL-10 decreased significantly (P<0.05,P<0.01); the expression of IL-17 increased significantly and the expression of Foxp3 decreased significantly in lung tissue (P<0.01). Compared with model group, the contents of IL-8, IL-17, and NE decreased in TCM-treated group 1 and 2, while the content of BALF IL-10 increased significantly (P<0.05). The content of IL-10 in serum increased significantly in TCM-treated group 2 (P<0.05); the protein expression of IL-17 of lung issue decreased significantly, and the protein expression of Foxp3 increased significantly (P<0.01). The pathological changes were improved significantly.Conclusion PM2.5 can induce lung injury caused by the imbalance of TH17/Treg. Both two treatments can significantly improve the lung injury induced by PM2.5 and the imbalance of TH17/Tregs immune system.
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<p><b>OBJECTIVE</b>The aim of this study was to investigate the impact of air pollution on the number of pediatric outpatient and emergency room visits in January 2013.</p><p><b>METHODS</b>Health-related data was from a major hospital in Haidian,Beijing while related data on air pollution was from the Chinese Research Academy of Environmental Sciences. Data on weather was from the China Weather Website. Number of hospital outpatient visits per day during the haze period was compared to those from the previous year to get the increase of percentage. Concentration-response functions were estimated using generalized additive modeling with natural log link function, while multiple structural change test was used to determine the changing point in CRFs. Constrained piecewise linear function was used to estimate the risks for different segments of CRFs.</p><p><b>RESULTS</b>The peak of NO(X), SO₂, PM(2.5) and PM(10) reached 672.63 µ g/m³, 146.20 µ g/m³, 312.19 µ g/m³ and 995.00 µ g/m³, around 28 December 2012 and 10 January 2013. The peaks of visits to the pediatric department were observed at the some days, showing 47.75% and 34.14% of increase in the visits to the pediatric department. In the low or intermediate ranges of concentration, all the four air pollutants were significantly associated with pediatric outpatient visits, in the form of C- and S- shape of concentration-response function. However, in the range of high concentration, only PM(10) and SO₂were significantly associated with the number of visits to the pediatric emergency room, appeared as the J-shape form. Discernable thresholds were found in S- and J- shapes which were located at 200 µg/m³, 20 µg/m³, 40 µg/m³ and 100 µ g/m³ for NO(X), SO₂, PM(2.5) and PM(10), respectively.</p><p><b>CONCLUSION</b>Air pollution during the haze period was associated with the increase of pediatric outpatient and emergency room visits. There were different sensitive groups within the pediatric cases. Their susceptibility showed a decreasing trend from C-, S-, to J- shape related group.</p>