23 research outputs found
ToothInpaintor: Tooth Inpainting from Partial 3D Dental Model and 2D Panoramic Image
In orthodontic treatment, a full tooth model consisting of both the crown and
root is indispensable in making the treatment plan. However, acquiring tooth
root information to obtain the full tooth model from CBCT images is sometimes
restricted due to the massive radiation of CBCT scanning. Thus, reconstructing
the full tooth shape from the ready-to-use input, e.g., the partial intra-oral
scan and the 2D panoramic image, is an applicable and valuable solution. In
this paper, we propose a neural network, called ToothInpaintor, that takes as
input a partial 3D dental model and a 2D panoramic image and reconstructs the
full tooth model with high-quality root(s). Technically, we utilize the
implicit representation for both the 3D and 2D inputs, and learn a latent space
of the full tooth shapes. At test time, given an input, we successfully project
it to the learned latent space via neural optimization to obtain the full tooth
model conditioned on the input. To help find the robust projection, a novel
adversarial learning module is exploited in our pipeline. We extensively
evaluate our method on a dataset collected from real-world clinics. The
evaluation, comparison, and comprehensive ablation studies demonstrate that our
approach produces accurate complete tooth models robustly and outperforms the
state-of-the-art methods
Cellulose-based film modified by succinic anhydride for the controlled release of domperidone
<p>Succinic anhydride (SAD) modified microcrystalline cellulose (MCC) films was prepared and used for the controlled release of the drug domperidone (dom). The morphology and chemical structure of the modified materials were characterized by SEM, FTIR, XRD and TG/DSC techniques. The physical properties, such as water uptake and swelling, light barrier properties, mechanical testing, <i>in vitro</i> degradation behavior, have been investigated. Results showed that the modified cellulose membranes exhibited good anti-UV properties, higher water uptake values, improved mechanical capacity and anti-biodegradability. In addition, the modified MCC films (MS) as the drug carrier indicated the controlled release of domperidone and the release mechanism was proposed using Korsmeyer–Peppas equation at pH 7.4. The developed drug delivery system possessed the profound significance in improving pharmacodynamics and bioavailability of drugs.</p
Mercury Ion Chemosensor Derived from Barbiturate Acid with Aggregation-Induced Emission Effect
The detection of toxic metals is indispensable for water safety. In this paper, a small molecule of aggregation-induced emission (AIE) with barbiturate group was synthesized. It combined with mercury ions to form a stable metal complex so as to enhance the color of the solution to achieve the visualization of ion detection. The fluorescent molecule showed good selectivity and anti-interference ability and had a low detection limit (DL = 22.27 nM) for mercury ion
Detection of nitroaromatic explosives by a 3D hyperbranched σ–π conjugated polymer based on a POSS scaffold
A three-dimensional hyperbranched polymer (3D-HP) with σ–π conjugated PDMPS (poly(dichloromethylphenylsilane)s) units covalently bonded to a polyhedral oligosilsesquioxane (POSS) scaffold was prepared by a one-step “thiol–ene click chemistry” reaction. Compared with POSS-based organic polymers, the 3D-HP with a flexible Si–Si chain showed enhanced solubility. This 3D hyperbranched polymer exhibited outstanding thermal stability and optimal photophysical properties. For probing nitroaromatics (NACs), the 3D-HP showed excellent sensitivity (Ksv = 2.83 × 104 M−1) against the presence of a tetrahydrofuran (THF) solution of 2,4,6-trinitrotoluene (TNT). In addition, the 3D-HP coated on glass films exposed to saturated DNT vapor exhibited a high quenching efficiency (ηEP) of the fluorescence of 3D-HP film, which was drastically suppressed (82%) for 300 s. The excellent fluorescent quenching performance of the 3D-HP can be attributed to the following points: (i) hyperbranched conjugated polymers afford multi-dimensional transport pathways for excitons migration; (ii) there exists in the polymer high electron affinity and rapid electron delocalization of σ–π conjugated polysilanes; (iii) noncovalent interactions between the electropositive δ+ Si atoms of σ–π conjugated polysilanes and N and/or O atoms of electron-deficient nitroaromatics (NACs) facilitate the adsorption of NACs. Furthermore, the bulky octathiol-POSS units in the 3D-HP can improve the permeability of the film sensor. This 3D hyperbranched σ–π conjugated polymer 3D-HP has the potential to be used to prepare sensitive, selective, and stable sensors for the detection of NACs explosives
Barbituric Derivative Nanoaggregates with Aggregation-Induced Emission and Mechanofluorochromism
© 2019 Xi Su et al. Three new nonplanar barbituric derivatives, named as TTB, TTTB, and TOB, were synthesized. The D-π-A type conjugated compounds showed obvious intramolecular charge transfer (ICT) property, which was evidenced by theoretical calculations and spectral analyses. All of them exhibited aggregation induced emission (AIE) when formed nanoaggregates. These nanoaggregates also showed reversible mechanofluorochromism (MFC). Their red light emission became deep red after grinding and then recovered with dichloromethane fuming. Hence, a strategy to fabricate mechanofluorochromic nanoaggregate phosphors via nonplanar π-skeleton and steric effect was demonstrated, and these nanophosphors possess potentials for mechanosensors and anticounterfeiting technology
Chemosensing Test Paper Based on Aggregated Nanoparticles of a Barbituric Acid Derivative
The development of sensitive, cheap, and portable methods for detecting nitroaromatics explosives has a profound significance and value for public health and environmental protection. For this purpose, a new D-π-A barbituric acid derivative CB-CYH with aggregation-induced emission (AIE) behavior was synthesized, which can interact with picric acid through photoinduced electron transfer (PET). Scanning electron microscopy (SEM) and dynamic light scattering (DLS) indicate that the enhanced emission of the compounds is related to the formation of nano-aggregates. It is well known that an important source of mechanochromic fluorescence (MCF) characteristic materials is the compound with AIE characteristics. The chemosensing test paper prepared by aggregated nanoparticles based on AIE properties is often subjected to external friction or squeeze during transportation or storage, resulting in changes of their optical properties, and destruction of test paper followed. Therefore, the development of compounds with AIE properties and stable optical properties in the presence of external stimuli is particularly important for chemosensing test paper. Molecular dynamics simulation (MDS) shows that the presence of hydrophobic cycloalkyl group in CB-CYH, which caused the molecules to be closely interspersed with each other; hence, it is difficult to change the microstructure and stacking mode of molecules by external stimulation simultaneously; the optical properties are not changed by external stimuli. Therefore, the test paper based on the AIE effect of CB-CYH was developed as chemosensing test paper for the detection of nitroaromatics
Facile fabrication of AIE/AIEE-active fluorescent nanoparticles based on barbituric for cell imaging applications
Four barbituric derivatives (1–4), were synthesized with obvious aggregation induced emission (AIE) or aggregation induced emission enhancement (AIEE) behaviors. The optical properties in different states and the mechanisms of the enhanced emission of 1–4 were investigated. We found that there were a large number of globular or blocky nanoparticles with average diameters from 229 to 394 nm in tetrahydrofuran (THF)/water solutions when the water fraction (fw) was 90%. The single crystal data of 2 and 4 reveal that multiple intermolecular interactions restrict the intramolecular motions, and promote the formation of a herringbone arrangement (4), thus permitting intense emission in the aggregate state. In addition, the frontier molecular orbital energy and band gap calculated by density functional theory (DFT) are consistent with the experimental results. Compound 4 is cell-permeable: upon entering the live cells, the dye molecules can accumulate in the lysosomes and turn on the fluorescence