Understanding cellulose pyrolysis via ab initio deep learning potential field.

Comprehensive and dynamic studies of cellulose pyrolysis reaction mechanisms are crucial in designing experiments and processes with enhanced safety, efficiency, and sustainability. The details of the pyrolysis mechanism are not readily available from experiments but can be better described via molecular dynamics (MD) simulations. However, the large size of cellulose molecules challenges accurate ab initio MD simulations, while existing reactive force field parameters lack precision. In this work, precise ab initio deep learning potentials field (DPLF) are developed and applied in MD simulations to facilitate the study of cellulose pyrolysis mechanisms. The formation mechanism and production rate of both valuable and greenhouse products from cellulose at temperatures larger than 1073 K are comprehensively described. This study underscores the critical role of advanced simulation techniques, particularly DLPF, in achieving efficient and accurate understanding of cellulose pyrolysis mechanisms, thus promoting wider industrial applications.

Synthesis and Functionalization of Graphene Materials for Biomedical Applications: Recent Advances, Challenges, and Perspectives.

Since its discovery in 2004, graphene is increasingly applied in various fields owing to its unique properties. Graphene application in the biomedical domain is promising and intriguing as an emerging 2D material with a high surface area, good mechanical properties, and unrivalled electronic and physical properties. This review summarizes six typical synthesis methods to fabricate pristine graphene (p-G), graphene oxide (GO), and reduced graphene oxide (rGO), followed by characterization techniques to examine the obtained graphene materials. As bare graphene is generally undesirable in vivo and in vitro, functionalization methods to reduce toxicity, increase biocompatibility, and provide more functionalities are demonstrated. Subsequently, in vivo and in vitro behaviors of various bare and functionalized graphene materials are discussed to evaluate the functionalization effects. Reasonable control of dose (<20 mg kg-1 ), sizes (50-1000 nm), and functionalization methods for in vivo application are advantageous. Then, the key biomedical applications based on graphene materials are discussed, coupled with the current challenges and outlooks of this growing field. In a broader sense, this review provides a comprehensive discussion on the synthesis, characterization, functionalization, evaluation, and application of p-G, GO, and rGO in the biomedical field, highlighting their recent advances and potential.

Atomic layer deposition SiO2 films over dental ZrO2 towards strong adhesive to resin.

Atomic layer deposition (ALD) is a self-limiting nanoscale film deposition technology with the advantages of good stability, consistency and conformability. In this study, we proposed to deposit silica (SiO2) films over dental zirconium-oxide (ZrO2) by ALD for better SiO2 films and higher bond strength between ZrO2 and resin. To investigate the superiority of film deposited by ALD, other surface modification methods such as sol-gel, vapor phase hydrolysis and electrostatic self-assembly were compared in terms of the short-term and long-term bond strength between ZrO2 and resin, measured by universal testing machine. Meanwhile, the surface morphology and chemical elemental analysis were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and Fourier transform infrared spectroscopy (FTIR). Results showed that the SiO2 films deposited by ALD or electrostatic self-assembly were uniform and consistent while sol-gel and vapor phase hydrolysis formed SiO2 films with cracks or pores, changing the morphology of ZrO2. ALD had the best results among all methods and increased the bond strength to 16.49 ± 1.60 MPa and 13.44 ± 1.63 MPa before and after aging respectively, which is expected to improve the long-term success rate of clinical dental ZrO2 prostheses.

Tranexamic Acid in Craniomaxillofacial Surgery: A Meta-Analysis and Systematic Review.

Objective: To compare the effectiveness of tranexamic acid (TXA) in reducing blood loss and decreasing surgery duration in craniomaxillofacial surgery. Methods: The literature was searched systematically for all comparative studies of the effect of TXA on craniomaxillofacial surgery with placebo to evaluate the efficacy of TXA in craniomaxillofacial surgery. The primary outcome was intraoperative blood loss, and secondary outcomes were postoperative hematocrit, postoperative hemoglobin, and operation duration. Results: This systematic review included 16 studies consisting of 958 patients. Meta-analysis revealed that compared with the placebo group, the TXA group showed a significant reduction in intraoperative blood loss of 139.81 mL (95% confidence interval, CI: -179.66 to -99.96 mL; p < 0.01), a shortening of the maxillary surgery duration of 15.48 min (95% CI: -21.03 to -9.92 min; p < 0.01), an elevation of the postoperative hemoglobin level of 0.74 mg/dL (95% CI: 0.42 to 1.07 mg/dL; p < 0.01), and a limited effect on increasing the postoperative hematocrit level of 1.77% (95% CI: 0.17 to 3.36; p = 0.03). Conclusion: The use of TXA in craniomaxillofacial surgery can effectively reduce intraoperative blood loss, maintain elevate postoperative hemoglobin and hematocrit levels, and reduce the operation duration.

[Comparison of fracture strength of two chairside CAD/CAM ceramic blocs with different thickness].

PURPOSE: To provide theoretical basis for clinical CAD/CAM restorations with a comparison of the fracture strength between two chairside CAD/CAM immediate restorative materials (IPS e.max CAD and Vita Enamic) with different occlusal thickness in vitro. METHODS: IPS e.max CAD and Vita Enamic full-crowns with occlusal thicknesses 1.5/2.0/2.5 mm were fabricated with CEREC and adhesively seated to dies customized by manufacturer (n=42). All specimens were stored in distilled water at 37 ℃ for 24 h. Later, static fractural loading was performed. The fracture surface was observed through scanning electron microscope (SEM) and energy dispersive spectrum (EDS). The composites of two materials were detected by X-Ray diffraction (XRD) techniques. The results of fracture strength were analyzed by one-way ANOVA and t-test via SPSS 20.0 software package. RESULTS: With the increase of occlusal thickness, the fracture strength of IPS e.max CAD increased remarkably. However, the Vita Enamic's fracture strength remained the same with no significant difference. With the occlusal thickness increased from 1.5 to 2.0 mm, there was no significant difference in the fracture strength between IPS e.max CAD group and Vita Enamic group. As the thickness increased from 1.5 to 2.0 mm, the fracture strength of IPS e.max CAD group was significantly higher than that of Vita Enamic group. The results of SEM showed that the filler particles of IPS e.max CAD were smaller compared to that of Vita Enamic. Cone cracks were mainly found in the fracture surface of IPS e.max CAD, while radical cracks appeared in Vita Enamic. EDS showed the metal oxide and SiO2 in Vita Enmic was significantly higher than that in IPS e.max CAD. XRD showed that the primary crystal phase of IPS e.max CAD was lithium silicate, while Vita Enamic was amorphous. CONCLUSIONS: Both IPS e.max CAD and Vita Enamic can meet the standard of clinical application as the occlusal thickness reaches 1.5 mm. IPS e.max CAD showed better fracture resistance when the thickness was greater than 2.0 mm.