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With organ transplantation facing many dilemmas, tissue and organ regeneration as an alternative has bright prospects. In regenerative medicine, Three-dimensional (3D) printing technology and stem cells has been widely applied to the treatment of diseases related to tissue or organ replacement in dentistry, respectively. However, there are very few studies on the combination of the two, and even fewer clinical studies have been reported in dentistry. In this review, the current oral tissue engineering in vivo and in vitro based on 3D printing and stem cell technology will be summarized, and the discussion on the development prospects of this research direction will be given. Besides, the working principles and advantages & disadvantages of several types of 3D printers, as well as the mechanism of stem cells in tissue engineering will be elucidated. This review provides clinicians and researchers with the current state of research and trends in the combination of stem cells and 3D printing technology to treat oral-related diseases. In the future, 3D bioprinters are poised for ongoing innovation with the advancement of relevant technologies, catalyzing an increase in clinical studies focused on treating oral diseases using stem cells and 3D scaffolds. Consequently, these developments will further advance the field of oral tissue engineering. [ABSTRACT FROM AUTHOR]

Charge transport rate is one of the key parameters determining the performance of organic electronic devices. Based on density functional theory, exchange-correlation functionals which adequately account for non-covalent interactions, such as M06-2X and wB97XD, should significantly improve the accuracy of charge transport rate calculations for large systems with non-covalent interactions. In this work, the B3LYP hybrid functional, the variant hybrid functional M06-2X, and the long-range-corrected wB97XD functional were used to perform geometry optimizations and charge transport rate calculations on 11 variants of tetrabenzo[ a,d,j,m ]coronene, including tetrabenzo[ a,d,j,m ]coronene itself and its tetra-substituted and octa-substituted derivatives. Our results indicate that the molecular geometries of these benzocoronene semiconductors are large quasi-planar conjugated π systems, and the incorporation of different substituents significantly affects their frontier molecular orbitals. The hole carrier mobility (µ +) and electron carrier mobility (µ −) of the methoxy-substituted derivatives (TBC(OCH3)4 and TBC(OCH3)8) were relatively low. The results of the tetrabenzo[ a,d,j,m ]coronene molecules studied were consistent with using the aforementioned M06-2X, wB97XD, and B3LYP methods. We found that the octa-substituted derivatives (TBCF8, TBCCl8, TBC(CH3)8, and TBC(CN)8) could be used as p-type organic semiconductor materials. [ABSTRACT FROM AUTHOR]

Formaldehyde adsorption on intrinsic La 2 O 3 surface, four-fold coordinated oxygen vacancy (VO 4c ), six-fold coordinated oxygen vacancy (VO 6c ), and iridium-doped La 2 O 3 (001) surface was studied by the first-principles method. The results show that formaldehyde adsorption on the Ir-doped La 2 O 3 (001) surface with VO 6c is the strongest because of the directional movement of electrons caused by the interaction of the Ir-5d orbitals and internal oxygen vacancy, wherein the adsorption energy is 3.23 eV. This model showed a significant increase in adsorption energy, indicating that Ir doping improves the formaldehyde adsorption capacity of the La 2 O 3 (001) surface. The energy band analysis shows that iridium doping introduces impurity energy levels into the intrinsic La 2 O 3 energy band, which enhances the interaction between the La 2 O 3 (001) surface and formaldehyde molecules. Density of state analysis indicated that the adsorption of formaldehyde molecules on the La 2 O 3 (001) surface is mainly due to the interaction between the O-2p, C-2p orbitals of formaldehyde and the Ir-5d orbital of iridium atoms. Furthermore, the existence of VO 4c and VO 6c defects has no effect on the position and shape of the valence and conduction bands. The effects of oxygen vacancy and iridium doping on the optical properties mainly appeared in the low-energy infrared and visible regions, making the O-2p, C-2p orbitals of formaldehyde and the Ir-5d, O-2p orbitals of the La 2 O 3 (001) surface become hybridized near the Fermi level and the electronic transition from the valence band to conduction band more likely to occur. The La 2 O 3 material can be used as an ideal photocatalytic material for formaldehyde degradation., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)