Clinical application of a digital positioning guide template during the extraction of maxillary wholly impacted supernumerary teeth / 口腔疾病防治

Objective@#To evaluate the clinical efficacy of positioning guide templates for maxillary wholly impacted supernumerary teeth to provide technological solutions for clinical applications. @*Methods @#After approval by the hospital ethics committee and informed consent given by the patients. Data from 136 patients with maxillary wholly impacted supernumerary teeth from January 2016 to April 2022 were analyzed retrospectively. The patients were divided into two groups according to the usage of the positioning guide template. The experimental group included patients using the positioning guide template (71 cases), and the control group did not use the positioning guide template (65 cases). The operation time and complications were statistically analyzed to evaluate the clinical efficacy after surgery. @*Results @# All operations were successfully completed. The average operation time in the experimental group was (21.5 ± 3.4) min, significantly shorter than that in the control group (27.2 ± 4.9) min. There were statistically significant differences between the experimental and control groups (t = 7.599, P<0.001). One week after the operation, there were no complications in the experimental group, and there were 2 cases of adjacent tooth injury and 3 cases of gingival numbness in the control group.@* Conclusion @# A digital positioning guide template can effectively shorten the time of maxillary wholly impacted supernumerary teeth extraction and is an effective means to assist clinical maxillary wholly impacted supernumerary teeth extraction.

Amorphous Ni-Fe-Se hollow nanospheres electrodeposited on nickel foam as a highly active and bifunctional catalyst for alkaline water splitting.

Developing earth-abundant highly efficient catalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is indispensable for the widespread implementation of electrochemical water splitting to store renewable energy. Herein, amorphous bimetallic selenide (Ni-Fe-Se) hollow nanospheres electrodeposited on nickel foam (Ni-Fe-Se/NF) are developed as a bifunctional catalyst for the HER and OER. The HER and OER bifunctional activity of Ni-Fe-Se/NF outperforms those of monometallic Ni-Se/NF and Fe-Se/NF owing to the synergy of Ni and Fe in Ni-Fe-Se/NF. Moreover, the amorphous hollow spherical morphology of Ni-Fe-Se/NF increases the active site density and facilitates the mass transfer of electrolytes and H2/O2 products. Ni-Fe-Se/NF drives a current density of 10 mA cm-2 with an overpotential of ∼85 mV for the HER and 100 mA cm-2 with an overpotential of ∼222 mV for the OER. As the HER and OER bifunctional catalyst, Ni-Fe-Se/NF can split alkaline water with total voltages of ∼1.52 V and ∼1.66 V at 10 mA cm-2 and 100 mA cm-2, respectively, and remain stable over 50 hours of operation in 1 M KOH.

The Preliminary Application of Augmented Reality in Unilateral Orbitozygomatic Maxillary Complex Fractures Treatment.

PURPOSE: Try to apply augmented reality (AR) technique which based on visual recognition artificial marks in the treatment of unilateral Orbitozygomatic Maxillary complex fractures (OZMF), and to explore the feasibility and the application value of the AR for assisting the oral and maxillofacial surgery (OMFS) treatment. METHODS: Based on the AR application JSARToolKit developed on the web, and combining with the self-designed tooth-borne type visual recognition artificial marks to display three-dimensional (3D) image of the region of interest (ROI), virtually designed the position and direction of plate on the jaw and helped OZMF surgery. According to some results to evaluate the postoperative effects, such as imaging, occlusion, facial appearance recovery, patients' satisfaction and operation time. RESULTS: The AR achieved the 3D image of ROI in real time, satisfied information enhancement of real scene, broadened the surgeon's horizons and improved the 3D recognition ability of maxillofacial tissue. After operation, patients had no discomforts, fracture reduction were well healed through imaging examination, and the titanium plate position was consistent with the preoperative planning. What is more, patients' facial appearance and occlusal function recovered well, significantly shorten the intraoperation time. CONCLUSION: Augmented reality technology is an effective method for OZMF treatment but there are still many technical difficulties which need to be get over, and its application in maxillofacial surgery and relevant basic theories are both worth further exploring.

Cellulose-Nanofiber-Mediated Sorption-Benefitting Holed Silicalite-1 Crystals.

Silicalite-1-type zeolites with unique intracrystal holes or cracks were successfully prepared using a cellulose nanofiber (CNF) as an additional mediating material, and their vapor phase adsorption properties toward methyl tert-butyl ether (MTBE) and n-nitrosodimethylamine (NDMA) were examined. It was found that the mixing protocol of CNF and structure-directing agents (SDAs), the addition amount of CNF, and the CNF/SDAs amount ratio play important roles in forming the holed silicalite-1. The synthesis route that preliminarily mixes CNF with SDAs in a series of controlled conditions is particularly beneficial for the formation of the holed silicalite-1 with mesoporosity and larger pores because the CNF-SDAs composite structure benefits the zeolite growth closely encompassing CNF inside the crystal structure. It also promotes the preferential formation of the orthorhombic phase vicinal to the CNF surface, namely, the surface of the formed internal holes or cracks, with the twin-type crystal size reduced as compared to the non-CNF-templated sample. On the contrary, the synthesis route that mixes CNF with SDAs-silicate composite ions tends to modify the twin-type crystal shape at the same time to form small but uniform well-crystallized particles with less holes or cracks and a dominative monoclinic phase. It was considered that both the inter-subunit structural defect and silanol defect whose content is increased with CNF addition influence the adsorptivity of MTBE and NDMA. Owing to the small twin-type crystal size, the smaller crystal subunits, and the favored short path from the surface of internal holes or cracks, the holed silicalite-1 derived from the CNF and SDA premixture assures the easiest access of adsorbate molecules to the most energetically favored sites and is most appropriate for the adsorption of both MTBE and NDMA among the examined zeolites.

Characterizing thermal-oxidation behaviors of nuclear graphite by combining O2 supply and micro surface area of graphite.

The effects of different parameters on oxidation rate are non-linear, interactive and diversified in which the change of adequacy of O2 supply is an important indicator. The influence of microstructure on oxidation rate became stronger worsening the fitting linearity to calculate the activation energy based on present method with the decreased adequacy of O2 supply due to the increase of temperature, the decrease of gas flow rate, etc. Here, we proposed a method to characterize thermal-oxidation behaviors of nuclear graphite by combining O2 supply and micro surface area of graphite. The proposed method improved the linearity and reduced the standard error of Arrhenius plots of oxidized graphite IG-110 (10 L/min reactant gas) and ET-10 (0.2 L/min reactant gas). The value of activation energy of graphite IG-110 oxidized under ASTM D7542 condition is calculated as 220 kJ/mol by this method echoing the results of previous studies with sufficient O2 supply. For the conditions with less O2 supply at low gas flow rate and/or high temperature, the change of microstructure of oxidized graphite should be obtained as an important factor influencing oxidation rate of graphite.

The Combined Application of Database and Three-Dimensional Image Registration Technology in the Restoration of Total Nose Defect.

OBJECTIVE: The purpose of this study is to present a virtual planning protocol based on the database and three-dimensional (3D) image registration technology for the restoration of the total nasal defect, and evaluate its feasibility and clinical efficacy. METHODS: Patients were scanned with a FaceScan to obtain the 3D facial model which was stored in an Extensible Neuroimaging Archive Toolkit (XNAT) database. Personalized search and similarity evaluation were performed in the database to find a normal 3D facial model with the highest similarity to the patient's. Then, the 2 models were imported into the dedicated software for 3D image registration to get the 3D model of the nasal defect part and the preoperative planning 3D facial model of virtual restoration. Subsequently, the dimensionality reduction algorithm was conducted to transform the 3D model of the nasal defect to a 2D flatten one for determining the scope of the forehead flap during surgery. Four weeks after the insetting surgery of forehead flap pedicle, the postoperative 3D facial model was gained. At last, the clinical efficacy was evaluated by comparing the difference between the preoperative planning and postoperative 3D facial model. RESULTS: The nasal shapes of the patients were good after the operation, and the results revealed that the maximum error was ranging from 3.12 to 4.07 mm with the mean error from 0.92 to 1.04 mm. CONCLUSION: The database and 3D image registration technology provide a new approach for precisely determining the scope of total nasal defect and the forehead flap, which may be used for reference in the accurate restoration of other facial soft tissue defects.

Application of Digital Diagnosis and Treatment Technique in Benign Mandibular Diseases.

PURPOSE: To explore the feasibility of preoperative planning for treatment of benign mandibular lesions (BML) using digital technologies such as three-dimensional (3D) reconstruction, measurement, visualization as well as image contrast and design of neural positioning protection template (NPPT) in combination with 3D printing technology in the BML diagnosis and treatment. METHODS: The 3D models of BML and inferior alveolar nerves (IAN) of 10 BML patients were reconstructed based on their digital imaging and communications in medicine (DICOM) data using MIMICS16.0 software. The models were used to visualize lesions and nerve contrast measurement and guide design of personalized NPPT and osteotomy after operation modality was determined in order to achieve accurate, minimally invasive operation with shortened intraoperative time. RESULTS: Intraoperative NPPT application could accurately locate lesions and their scope and assist osteotomy. The measurement results were consistent with those of preoperative reconstruction and measurement. The BML were curetted completely without damage IAN. The 10 BML patients had no numbness and other discomforts in the lower lip and mandibular teeth after operation. CONCLUSIONS: The digital diagnosis and treatment technology is an effective method for functional treatment of BML patients and its application could achieve personalized, minimally invasive and precise treatment and save intraoperation time.

Automatic detection of particle size distribution by image analysis based on local adaptive canny edge detection and modified circular Hough transform.

To obtain size distribution of nanoparticles, scanning electron microscope (SEM) and transmission electron microscopy (TEM) have been widely adopted, but manual measurement of statistical size distributions from the SEM or TEM images is time-consuming and labor-intensive. Therefore, automatic detection methods are desirable. This paper proposes an automatic image processing algorithm which is mainly based on local adaptive Canny edge detection and modified circular Hough transform. The proposed algorithm can utilize the local thresholds to detect particles from the images with different degrees of complexity. Compared with the results produced by applying global thresholds, our algorithm performs much better. The robustness and reliability of this method have been verified by comparing its results with manual measurement, and an excellent agreement has been found. The proposed method can accurately recognize the particles with high efficiency.

Influence of Fe loadings on desulfurization performance of activated carbon treated by nitric acid.

A series of Fe supported on activated carbon treated by nitric acid are prepared by incipient wetness impregnation with ultrasonic assistance and characterized by N2 adsorption-desorption, X-ray diffraction, Fourier transform infrared spectrum and X-ray photoelectron spectroscopy. It has shown that Fe loadings significantly influence the desulfurization activity. Fe/NAC5 exhibits an excellent removal ability of SO2, corresponding to breakthrough sulfur capacity of 323 mg/g. With the increasing Fe loadings, the generated Fe3O4 and Fe2SiO4 increase, but Fe2(SO4)3 is observed after desulfurization. Fe/NAC1 has a Brunauer-Emmett-Teller (BET) surface area of 925 m2/g with micropore surface area of 843 m2/g and total pore volume of 0.562 cm3/g including a micropore volume of 0.300 cm3/g. With the increasing Fe loadings, BET surface area and micropore volume decrease, and those of Fe/NAC10 decrease to 706 m2/g and 0.249 cm3/g. The Fe loadings influence the pore-size distribution, and SO2 adsorption mainly reacts in micropores at about 0.70 nm. C=O and C-O are observed for all samples before SO2 removal. After desulfurization, the C-O stretching is still detected, but the C=O stretching vibration of carbonyl groups disappears. The stretching of S-O or S=O in sulfate is observed at 592 cm-1 for the used sample, proving that the existence of [Formula: see text].

[Adsorption performances for sulfur dioxide using imidazole ionic liquids].

To discover the SO2 adsorption laws of ionic liquids in simulating flue gas, the SO2 adsorbents 1-butyl-3-methylimidazolium chloride ([Bmim] Cl), 1-butyl-3-methylimidazolium nitrate ([Bmim] NO3), 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim] BF4) and 1-amyl-3-methylimidazolium chloride [C5 mim] Cl ionic liquids were synthesized. The performances were studied under different conditions and the general rules of regeneration were explored. And the diversification of [Bmim] Cl chemical structures, which were pre-desulfated, post-desulfated and post-regenerated, were characterized by Fourier Transform Infrared Spectroscopy. The results illustrated that these ionic liquids all had the ability of SO2 adsorption, and the order of SO2 adsorption performances was [C5 mim] C1 > [Bmim] Cl > [Bmim] NO3 > [Bmim] BF4. The total SO2 adsorption amount of [C5 mim] Cl was 200. 8 mg/g, and the optimal adsorption temperature of [Bmim] Cl was 40 degrees C. The order of anions impacting adsorption performances of ionic liquids was Cl- > NO3- > BF4-. The sulfur capacity of ionic liquids decreased to 26.5 mg/g from 65.9 mg/g after desorption under the condition of heating (90 degrees C), vacuum (0.09 MPa) and 4.0 h. In addition, the chemical structures of ionic liquid had changed, and the forms of SO2 adsorbed by [Bmim] Cl were physico-chemical processes.

Historical analysis of SO2 pollution control policies in China.

Coal is not only an important energy source in China but also a major source of air pollution. Because of this, China's national sulfur dioxide (SO(2)) emissions have been the highest in the world for many years, and since the 1990s, the territory of China's south and southwest has become the third largest acid-rain-prone region in the world. In order to control SO(2) emissions, the Chinese government has formulated and promulgated a series of policies and regulations, but it faces great difficulties in putting them into practice. In this retrospective look at the history of SO(2) control in China, we found that Chinese SO(2) control policies have become increasingly strict and rigid. We also found that the environmental policies and regulations are more effective when central officials consistently give environmental protection top priority. Achieving China's environmental goals, however, has been made difficult by China's economic growth. Part of this is due to the practice of environmental protection appearing in the form of an ideological "campaign" or "storm" that lacks effective economic measures. More recently, better enforcement of environmental laws and regulations has been achieved by adding environmental quality to the performance assessment metrics for leaders at all levels. To continue making advances, China needs to reinforce the economic and environmental assessments for pollution control projects and work harder to integrate economic measures into environmental protection. Nonetheless, China has a long way to go before economic growth and environmental protection are balanced.