Objectives
To compare the transfer accuracy of two digital transfer trays, the three-dimensional printed (3D printed) tray and the vacuum-formed tray, in the indirect bonding of labial brackets.
Materials and Methods
Ten digital dental models were constructed by oral scans using an optical scanning system. 3D printed trays and vacuum-formed trays were obtained through the 3Shape indirect bonding system and rapid prototyping technology (10 in each group). Then labial brackets were transferred to 3D printed models, and the models with final bracket positioning were scanned. Linear (mesiodistal, vertical, buccolingual) and angular (angulation, torque, rotation) transfer errors were measured using GOM Inspect software. The mean transfer errors and prevalence of clinically acceptable errors (linear errors of ≤0.5 mm and angular errors of ≤2°) of two digital trays were compared using the Mann-Whitney U-test and the Chi-square test, respectively.
Results
The 3D printed tray had a lower mean mesiodistal transfer error (P < .01) and a higher prevalence of rotation error within the limit of 2° (P = .03) than did the vacuum-formed tray. Linear errors within 0.5 mm were higher than 90% for both groups, while torque errors within 2° were lowest at 50.9% and 52.9% for the 3D printed tray and vacuum-formed tray, respectively. Both groups had a directional bias toward the occlusal, mesial, and buccal.
Conclusions
The 3D printed tray generally scored better in terms of transfer accuracy than did the vacuum-formed tray. Both types of trays had better linear control than angular control of brackets.
Long-distance droplet motion and selective droplet manipulation on repeated hydrophobic surface patterns with gradient wettability by in-plane cyclic vibration.
Solar
steam generation (SSG) as a pollution-free and sustainable
way for desalination or wastewater treatment has attracted great attention
in recent years. Herein, we report the fabrication of novel aerogels
GAHAS and GAHAF composed of 3-aminopropyltriethoxysilane (KH550)-modified
hollow glass microspheres (HGM) and reduced graphene oxide (RGO) by
a sol–gel method for highly efficient SSG. The RGO can well
wrap on modified HGM and form an interpenetrated porous structure
with an excellent mechanical property. In addition, benefiting from
the hollow structure of HGM, GAHAS obtained by supercritical CO2 drying well maintains the original structure of the hydrogel
and shows low thermal conductivity (0.0823 W m–1 K–1) in the wet state and self-floating ability.
Combined with its superhydrophilic wettability and high light absorption
(ca. 93%), the as-prepared GAHAS shows an outstanding photothermal
conversion efficiency of 89.13% under 1 sun (1 kW m–2) illumination and excellent stability. Moreover, from the simulated
seawater outdoor solar desalination experiment, it was found that
the concentrations of the four primary ions K+, Ca2+, Na+, and Mg2+ in purified water are
1.65, 0.09, 1.42, and 0.32 mg L–1, respectively,
and fully meet drinking water standards. Thus, our GAHAS aerogel shows
great potential for practical application in SSG. This work enriches
the photothermal materials and may provide a new idea for design and
creation of HGM-based photothermal materials with low thermal conductivity,
tunable porosity, high mechanical strength, self-floating ability,
and high solar energy conversion efficiency for SSG.
Scorpion toxins can kill other animals by inducing paralysis and arrhythmia, which limits the potential applications of these agents in the clinical management of diseases. Antitumor-analgesic peptide (AGAP), purified from Karsch, has been proved to possess analgesic and antitumor activities. Trp, a conserved aromatic residue of AGAP, might play an important role in mediating AGAP activities according to the sequence and homology-modeling analyses. Therefore, an AGAP mutant, W38G, was generated, and effects of both AGAP and the mutant W38G were examined by whole-cell patch clamp techniques on the sodium channels hNa1.4 and hNa1.5, which were closely associated with the biotoxicity of skeletal and cardiac muscles, respectively. The data showed that both W38G and AGAP inhibited the peak currents of hNa1.4 and hNa1.5; however, W38G induced a much weaker inhibition of both channels than AGAP. Accordingly, W38G exhibited much less toxic effect on both skeletal and cardiac muscles than AGAP The analgesic activity of W38G and AGAP were verified as well, and W38G retained analgesic activity similar to AGAP. Inhibition to both Na1.7 and Na1.8 was involved in the analgesic mechanism of AGAP and W38G. These findings indicated that Trp was a key amino acid involved in the biotoxicity of AGAP, and the AGAP mutant W38G might be a safer alternative for clinical application because it retains the analgesic efficacy with less toxicity to skeletal and cardiac muscles.
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