Craiglorentsen0037

Objective This in vivo study compared two bleaching techniques with regard to the degree of tooth sensitivity (TS), color change, and treatment stability for a 6-month follow-up period. Materials and methods Sixty volunteers were selected according to inclusion and exclusion criteria and submitted to in-office bleaching. For group 1, we performed one bleaching session with a 35% hydrogen peroxide gel and a second bleaching session after 7 days; for group 2, we performed two bleaching sessions with two applications per session, each session with a 7-day interval, using a light-emitting diodes (LEDs) device emitting violet light (405-410 nm) without employing peroxide-containing bleaching gel. TS was recorded immediately before and immediately after each bleaching session using the Variance Analogic Scale. The color of upper central incisors and upper canines at baseline was recorded immediately after each bleaching session, after 15, 30, and 180 days, with a value-oriented shade guide used by two well-trained observers. Results The two whitening protocols results were similar regarding the immediate effectiveness and 6-month stability of tooth whitening. Dental bleaching with violet LED did not promote postoperative pain sensitivity at any of the evaluated times. However, dental bleaching performed with 35% hydrogen peroxide promoted higher postoperative pain sensitivity. Conclusions The violet light alone provided dental bleaching and had the clinical advantage of promoting less immediate postoperative sensitivity; however, an unwanted repigmentation occurred after dental bleaching with light alone.Mice derived entirely from embryonic stem (ES) cells can be generated through tetraploid complementation. Although XY male ES cell lines are commonly used in this system, occasionally, monosomic XO female mice are produced through spontaneous Y chromosome loss. Here, we describe an efficient method to obtain monosomic XO ES cells by CRISPR-Cas9-mediated deletion of the Y chromosome, allowing generation of female clonal mice by tetraploid complementation. The monosomic XO female mice are viable and able to produce normal male and female offspring. Direct generation of clonal mice in both sexes can significantly accelerate the production of complex genetically modified mouse models.We report the generation of gas-phase riboguanosine radicals that were tagged at ribose with a fixed-charge 6-(trimethylammonium)hexane-1-aminocarbonyl group. The radical generation relied on electron transfer from fluoranthene anion to noncovalent dibenzocrown-ether dication complexes which formed nucleoside cation radicals upon one-electron reduction and crown-ether ligand loss. The cation radicals were characterized by collision-induced dissociation (CID), photodissociation (UVPD), and UV-vis action spectroscopy. Identification of charge-tagged guanosine radicals was challenging because of spontaneous dissociations by loss of a hydrogen atom and guanine that occurred upon storing the ions in the ion trap without further excitation. The loss of H proceeded from an exchangeable position on N-7 in guanine that was established by deuterium labeling and was the lowest energy dissociation of the guanosine radicals according to transition-state energy calculations. Rate constant measurements revealed an inverse isotope effect on the loss of either hydrogen or deuterium with rate constants kH = 0.25-0.26 s-1 and kD = 0.39-0.54 s-1. We used time-dependent density functional theory calculations, including thermal vibronic effects, to predict the absorption spectra of several protomeric radical isomers. The calculated spectra of low-energy N-7-H guanine-radical tautomers closely matched the action spectra. Transition-state-theory calculations of the rate constants for the loss of H-7 and guanine agreed with the experimental rate constants for a narrow range of ion effective temperatures. Our calculations suggest that the observed inverse isotope effect does not arise from the isotope-dependent differences in the transition-state energies. Instead, it may be caused by the dynamics of post-transition-state complexes preceding the product separation.A TBAI/K2S2O8-promoted [4 + 2] annulation of ketene N,S-acetals, and N-tosylhydrazones was efficiently developed, enabling straightforward access to a variety of trisubstituted pyridazines in reasonable to good yields. The synthetic methodology features a broad substrate scope and a good functional group tolerance. Control experiments demonstrated the indispensability of the alkylthio functionality in the enaminone substrates.The functional modification in graphene leads to novel characteristics. We study a lithiated graphene quantum dot (LiG) and adsorption of a single alkali atom (M = Li, Na, and K) on its surface using the B3LYP-D3 method. The structures of M@LiG attain the lowest energy with M adsorbed on the terminal ring of LiG. The isomers of M@LiG are stable against dissociation into M and LiG. The frontier orbital energy gap of M@LiG is significantly reduced to 0.41-0.58 eV as compared to that of LiG (2.16 eV). selleck products There is a strong charge transfer of 0.91-0.96|e| from M to LiG in all M@LiG systems, which is slightly reduced in the lowest-energy Na@LiG structure. The CAM-B3LYP results suggest a significant increase in the dipole moment and mean polarizabilities of M@LiG due to the charge transfer and smaller energy gaps, respectively. The first static hyperpolarizability (β0) value of the lowest-energy M@LiG structures becomes as large as 11.5 × 105 a.u. for M = K. Our time-dependent density functional theory (TDDFT) calculations suggest that the enormously high value of β0 results due to lower transition energy and higher transition dipole moment for the crucial electronic transition.The growth of three-dimensional covalent organic frameworks (3D COFs) with new topologies is still considered as a great challenge due to limited availability of high-connectivity building units. Here we report the design and synthesis of 3D triptycene-based COFs, termed JUC-568 and JUC-569, following the deliberate symmetry-guided design principle. By combining a triangular prism (6-connected) node with a planar triangle (3-connected) or another triangular prism node, the targeted COFs adopt non-interpenetrated ceq or acs topology, respectively. Both materials show permanent porosity and impressive performance in the adsorption of CO2 (∼98 cm3/g at 273 K and 1 bar), CH4 (∼48 cm3/g at 273 K and 1 bar), and especially H2 (up to 274 cm3/g or 2.45 wt % at 77 K and 1 bar), which is highest among porous organic materials reported to date. This research thus provides a promising strategy for diversifying 3D COFs based on complex building blocks and promotes their potential applications in energy storage and environment-related fields.