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Background Patients with unilateral cleft lip and palate were associated with different nasomaxillary complex from the normal population. Although the biomechanical effects of conventional rapid palatal expansion (Hyrax expansion) and bone-borne rapid palatal expansion (micro-implant-assisted expansion) in non-cleft patients have been identified by multiple studies, little is known in patients with unilateral cleft lip and palate. The purpose of this study was to investigate and compare the biomechanical effects of the conventional and bone-borne palatal expanders in a late adolescence with unilateral cleft lip and palate. Methods A cone beam CT scan of a late adolescence with unilateral cleft lip and palate was selected to construct the three-dimensional finite element models of teeth and craniofacial structures. The models of conventional and born-borne palatal expanders were established to simulate the clinical maxillary expansion. The geometric nonlinear theory was applied to evaluate the Von Mises stress distribution and displacements in craniofacial structures and teeth. Results Bone-borne palatal expander achieved more transverse movement than conventional palatal expander in the whole mount of craniofacial regions, and the maximum amount of expansion was occurred anteriorly along the alveolar ridge on cleft-side. The expanding force from born-borne palatal expander resulted in more advancement in nasomaxillary complex than it in conventional palatal expander, especially in the anterior area of the minor segment of maxilla. Stresses from the both expanders distributed in similar patterns, but larger magnitudes and ranges were generated using the bone-borne expander around the maxillary buttresses and pterygoid plates of sphenoid bone. The maximum expanding stresses from born-borne palatal expander were concentrated on palatal slope supporting minscrews, whereas those from conventional palatal expander were concentrated on the anchoring molars. In addition, the buccal tipping effect of teeth generated using the bone-borne expander was less than it using the conventional palatal expander. Conclusion Bone-borne expander generated enhanced skeletal expansion at the levels of alveolar and palate in transversal direction, where the miniscrews contributed increased expanding forces to maxillary buttresses and decreased forces to buccal alveolar. Bone-borne expanders presented a superiority in correcting the asymmetric maxilla without surgical assistant in late adolescence with unilateral cleft lip and palate.

The tetraruthenium tetrahydrido carbonyl cluster Ru4(µ-H)4(CO)12 (1) reacts with diphenylvinylphosphine under thermal activation to give the substitution products Ru4(µ-H)4(CO)12−n(κ1-Ph2PCH=CH2)n, (2) (n = 3 (a); 4 (b)). Both 2a and 2b have been completely characterized, including by single-crystal X-ray diffraction analysis. Each of the diphenylvinylphosphine ligands in 2a and 2b is terminally bound, via the phosphorus atom, to a different ruthenium metal center, while the hydride positions in the Ru4(µ-H)4 cores retain the D2d symmetry of the parent cluster 1. Clusters 2a and 2b were able to retain their structural integrity at elevated temperatures. Graphic Abstract: Thermolysis of Ru4(μ-H)4(CO)12 (1) in cyclohexane with diphenylvinylphosphine afforded the tri- and tetra-substituted derivatives Ru4(μ-H)4(CO)9(κ1-Ph2PCH=CH2)3 (2a) and Ru4(μ-H)4(CO)8(κ1-Ph2PCH=CH2)4 (2b). For both substituted clusters, the diphenylvinylphosphine ligands are bound terminally to the tetraruthenium core via the phosphorus atoms while the hydride positions retain the D2d symmetry of the parent cluster 1.[Figure not available: see fulltext.] Ministry of Education (MOE) Nanyang Technological University This work was supported by Hwa Chong Institution as well as Nanyang Technological University and the Ministry of Education with a research Grant (No. M4011158).

Peat is known as problematic ground with low bearing capacity and extensively high compressibility. Bio-cementation or commonly known as microbial-induced calcite precipitation (MICP) has been recently introduced as a ground improvement alternative for peat under waterlogged condition. Using isolated bacteria strains P19 and P21 from tropical peat, it is found that unconfined compression strength (UCS) increases with bacteria concentration at a reducing rate. A maximum unconfined compressive strength of 82.05 kPa was measured with bacteria strain P21 at 108 CFU/mL. For the range of cementation reagent varying from 0.1 to 4.0 mol/kg, the largest strength improvement occurred at 1 mol/kg and 2 mol/kg using indigenous bacteria and bacteria strain P21, respectively, for peat with sand content of 25%. At 4.0 mol/kg, the cementation reagent has detrimental effect to MICP resulting in significant reduction in strength. Due to MICP, the UCS of peat increases with sand content. Calcium carbonate precipitation results in a reduction of permeability and an increment of strength of peat–sand mixture under a submerged condition up to 28 days.

Due to their designable properties, microstructural materials have emerged as an important class of materials that have the potential for used in a variety of applications. The design of such materials is challenged by the multifunctionality requirements and various constraints stemmed from manufacturing limitations and other practical considerations. Traditional design methods such as those based on topological optimization techniques rely heavily on high-dimensional physical simulations and can be inefficient. In addition, it is difficult to impose geometrical constraints in those methods. In this work, we propose a deep learning model based on deep convolutional generative adversarial network (DCGAN) and convolutional neural network (CNN) for the design of microstructural materials. The DCGAN is used to generate design candidates that satisfy geometrical constraints and the CNN is used as a surrogate model to link the microstructure to its properties. Once trained, the two networks are combined to form the design network which is utilized to for the inverse design. The advantages of the method include its high efficiency and the simplicity in handling geometrical constraints. In addition, no high-dimensional sensitivity simulations are required. The performance of the method is demonstrated on the design of microstructural materials with desired compliance tensor, subject to specified geometrical constraints.

Background and objective As the pathological mechanisms of AD are complex, increasing evidence have demonstrated Chinese Medicine with multi-ingredients and multi-targets may be more suitable for the treatment of diseases with complex pathogenesis. Therefore, the study was to preliminarily decipher the bioactive compounds and potential mechanisms of Qiong Yu Gao (QYG) for AD prevention and treatment by an integrated network pharmacology approach. Methods Putative ingredients of QYG and significant genes of AD were retrieved from public database after screening. Then QYG ingredients target proteins/genes were obtained by target fishing. Compound-target-disease network was constructed using Cytoscape to decipher the mechanism of QYG for AD. KEGG pathway and GO enrichment analysis were performed to investigate the molecular mechanisms and pathways related to QYG for AD treatments. Results Finally, 70 compounds and 511 relative drug targets were collected. In which, 17 representative direct targets were found. Gene ontology enrichment analysis revealed that the adenylate cyclase-inhibiting G-protein coupled acetylcholine receptor signaling pathway was the key biological processes and were regulated simultaneously by the 17 direct targets. The KEGG pathway enrichment analysis found that three signaling pathways were closely related to AD prevention and treatment by QYG, including PI3K-Akt signaling pathway, regulation of actin cytoskeleton pathway and insulin resistance pathway. Conclusion This study demonstrated that QYG exerted the effect of preventing and treating AD by regulating multi-targets with multi-components. Furthermore, the study demonstrated that a network pharmacology-based approach was useful for elucidation of the interrelationship between complex diseases and interventions of Chinese herbal medicines.

Tubes with various cross-sectional shapes are widely used in automotive and bicycle manufacture for lightweight considerations. This study proposes a compound forming process for hydroforming a rectangular cross-sectional tube of aluminum alloys AA6061-O. The compound forming process is divided into crushing, hydroforming, and calibration. The finite element simulation software DEFORM was used to analyze the plastic deformation pattern of the tube during the compound forming processes and determine feasible loading paths that can generate a uniform thickness distribution, a lower internal pressure, and a smaller clamping force. The effects of varied internal pressures on the product shapes, thickness distributions, and forming loads are discussed. A self-designed hydroforming test machine with an internal pressure capacity of 30 MPa and axial feeding force of 40 tons was used to conduct hydroforming experiments. The experimental results of the product thickness distributions and dimensions were compared with simulation results, and the validity of the FE modeling is confirmed. Sound products with the required shape and dimensions can be obtained using the proposed hydraulic compound forming process with a low internal pressure of 8 MPa.

Fire extinction in a closed ship cabin is one of the efficient measures for fire fighting. It would be of significant values for engineering application to study the smoke characteristics of a fire within a closed cabin. This paper constructs a fire model with analyses of smoke height, self-extinction time, the cabin temperature at the quenching time and CO density based on the study of the fire behavior and the smoke characteristics in a confined cabin. It also presents a simulation verification for the theoretical model. The results demonstrates that this model does well to study the characteristics of smoke production and flow in a closed cabin. So it could be a good reference for crews to control damage while suppressing fire in closed cabins.