(1) Background: Bacterial reinfection and root fracture are the main culprits related to root canal treatment failure. This study aimed to assess the utility of quercetin solution as an adjunctive endodontic irrigant that strengthen root canal dentin with commitment anti-biofilm activity and bio-safety. (2) Methods: Based on a noninvasive dentin infection model, dentin tubules infected with Enterococcus faecalis (E. faecalis) were irrigated with sterile water (control group), and 0, 1, 2, 4 wt% quercetin-containing ethanol solutions. The live and dead bacteria proportions within E. fae-calis biofilms were analyzed using confocal laser scanning microscopy (CLSM). Elastic modulus and hydroxyproline release and X-ray photoelectron spectroscopy (XPS) characterization was tested on irrigant-treated demineralized dentin to evaluate irrigants’ biostability. The cytotoxicity of irrigants was tested by CCK-8 assay. (3) Results: Quercetin increased the proportion of dead bacteria volumes within E. faecalis, and improved the flexural strength of dentin collagen com-pared to control group. The XPS characterization revealed an increase in C-O peak area under both C1s and O1s narrow-scan spectra. The CCK-8 assay confirmed no cytotoxicity of quercetin solutions. (4) Conclusions: Quercetin exhibited anti-biofilm activity, collagen-stabilizing effect as well as cytocompatibility, supporting quercetin as a potential candidate for endodontic irrigant.

The cast defects strongly degrade the mechanical properties in cast alloys. The effect of Sn addition on Al-Si alloys was investigated by 3D computed tomography, SEM and TEM. Amorphous Sn oxides are found near the alumina film, cause more shrinkage pores, initiate cracks and deteriorate mechanical properties. This work suggests not adding Sn in various Al alloys used in cast state.

Macadamia nut plantings in China are expanding year by year. In order to further promote the superior varieties, this study analyzed the effects of different varieties of rootstock and scion on the survival rate as well as the effects of 18 different ratios of substrate composition on seedling growth were analyzed. The results showed that: The survival rate of HAES788 varieties as rootstock and Guire No.1 as scion was the highest, reaching 96%. The optimal grafting time in December was better than that in March. Substrate formulations 12, 13, 15 and 16 had agglomerated soil and well-developed root systems compared to the controls. Plant height, stem diameter, leaf length, leaf width, and dry weight of aboveground and underground parts were significantly higher than those of the control. In addition, the substrate formulations 12, 13, 15 and 16 significantly improved the organic matter, total nitrogen, and total potassium content of the substrate soils, but little on total phosphorus content. All in all, macadamia grafting times are best in December, with HAES788 and Guire No.1 being the best rootstock and scion. Substrate formulations 12, 13, 15 and 16 are the optimal formula. This study provides a solid foundation to produce high-quality macadamia seedlings.