Alston Cotton (zebrasatin63)
OBJECTIVES The aim of this study was to assess the in vitro caries preventive effect of nanocomplexed solutions of hydroxypropyl-β-cyclodextrin and γ-cyclodextrin associated with titanium tetrafluoride (TiF4) after different complexation times (12 or 72 h). MATERIALS AND METHODS Enamel blocks were randomly distributed in 9 groups (n = 11) negative control, hydroxypropyl-β-cyclodextrin, γ-cyclodextrin, TiF4, hydroxypropyl-β-cyclodextrinTiF4 12 h, hydroxypropyl-β-cyclodextrinTiF4 72 h, γ-cyclodextrinTiF4 12 h, γ-cyclodextrinTiF4 72 h, and NaF (positive control). The solutions were applied for 1 min and the blocks were exposed to a biofilm model. Nanocompounds were characterized by differential scanning calorimetry and X-ray powder diffraction. The percentage of surface microhardness loss (%SML), mineral density changes (ΔZ), lesion depth, surface morphology (scanning electron microscopy-SEM), and chemical characterization (energy-dispersive spectroscopy-EDS) were assessed. Plerixafor chemical structure RESULTS No oxidation was observed, and the formation of the nanocomplexes was evidenced by changes in the melting point compared to pure cyclodextrins and the loss of crystallinity of the materials. Hydroxypropyl-β-cyclodextrinTiF4 72 h resulted in lower %SML than negative control, hydroxypropyl-β-cyclodextrin, γ-cyclodextrin, and TiF4 (p 0.05). SEM/EDS detected Ti in the blocks subjected to TiF4-products. CONCLUSION The hydroxypropyl-β-cyclodextrinTiF4 72 h solution showed caries preventive effect on the surface and subsurface of the enamel. CLINICAL RELEVANCE A hydroxypropyl-β-cyclodextrin nanosystem, in association with TiF4 after 72 h of complexation, may be a promising agent for the prevention of enamel demineralization.A Gram-stain-positive, aerobic, spore-forming actinobacterial strain, designated 160415T, was isolated from a surface soil sample, which was formed on basaltic parent material, collected from Samsun, Turkey. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 160415T clustered closely with species of the genus Nonomuraea, and showed the highest sequence similarity to Nonomuraea zeae NEAU-ND5T, Nonomuraea candida HMC10T and Nonomuraea turkmeniaca DSM 43926T with 99.1%, 98.9% and 98.7%, respectively. Chemotaxonomic properties including major menaquinones, diaminopimelic acid, sugar and phospholipid profiles also confirmed the affiliation of the strain to the genus Nonomuraea. The DNA G+C content of strain 160415T was 69.6 mol%. DNA-DNA hybridization and average nucleotide identity values between the strain and closely related type strains were less than the recommended cut-off values. On the basis of phylogenetic relationships, genotypic and phenotypic characterizations, strain 160415T represents a novel species of the genus Nonomuraea, for which the name Nonomuraea basaltis sp. nov. is proposed. The type strain is 160415T (= KCTC 39875T = DSM 104309T).Time delays play important roles in genetic regulatory networks. In this paper, a gene regulatory network model with time delays and mutual inhibition is considered, where time delays are regarded as bifurcation parameters. In the first part of this paper, we analyze the associated characteristic equations and obtain the conditions for the stability of the system and the existence of Hopf bifurcations in five special cases. Explicit formulas are given to determine the direction and stability of the Hopf bifurcation by using the normal form method and the center manifold theorem. Numerical simulations are then performed to illustrate the results we obtained. In the second part of the paper, using time-delayed stochastic numerical simulations, we study the impact of biological fluctuations on the system and observe that, in modest noise regimes, unexpectedly, noise acts to stabilize the otherwise destabilized oscillatory system.In contrast to the wealth of proven therapies for heart fa