Multivariate Linear Regression (MLR) models utilizing computationally-derived and empirically-derived physical organic molecular descriptors are described in this review. Several reports ...demonstrating the effectiveness of this methodological approach towards reaction optimization and mechanistic interrogation are discussed. A detailed protocol to access quantitative and predictive MLR models is provided as a guide for model development and parameter analysis.
The utilization of physical organic molecular descriptors for the quantitative description of reaction outcomes in multivariate linear regression models is demonstrated as an effective tool for
a priori
prediction and mechanistic interrogation.
2019-nCoV is a newly identified coronavirus with high similarity to SARS-CoV. We performed a structural analysis of the receptor binding domain (RBD) of spike glycoprotein responsible for entry of ...coronaviruses into host cells. The RBDs from the two viruses share 72% identity in amino acid sequences, and molecular simulation reveals highly similar ternary structures. However, 2019-nCoV has a distinct loop with flexible glycyl residues replacing rigid prolyl residues in SARS-CoV. Molecular modeling revealed that 2019-nCoV RBD has a stronger interaction with angiotensin converting enzyme 2 (ACE2). A unique phenylalanine F486 in the flexible loop likely plays a major role because its penetration into a deep hydrophobic pocket in ACE2. ACE2 is widely expressed with conserved primary structures throughout the animal kingdom from fish, amphibians, reptiles, birds, to mammals. Structural analysis suggests that ACE2 from these animals can potentially bind RBD of 2019-nCoV, making them all possible natural hosts for the virus. 2019-nCoV is thought to be transmitted through respiratory droplets. However, since ACE2 is predominantly expressed in intestines, testis, and kidney, fecal-oral and other routes of transmission are also possible. Finally, antibodies and small molecular inhibitors that can block the interaction of ACE2 with RBD should be developed to combat the virus.
•Spike glycoprotein of 2019-nCoV may confer a strong ACE2 receptor binding.•Conserved expression of ACE2 suggests a wide range of natural hosts for 2019-nCoV.•Tissue expression of ACE2 suggests multiple routes of 2019-nCoV transmission.
A modified grey prediction model is employed to accurately forecast China's overall and industrial electricity consumption. To this end, a novel optimized grey prediction model, combining a new ...initial condition and rolling mechanism, is designed on the principle of “new information priority”. The previous initial conditions possess the inherent deficiencies of having a fixed structure and poor adaptability to changing raw data. To overcome these deficiencies, the new initial condition, possessing alterable weighted coefficients, is proposed. Its generating parameters can be optimally determined by employing a particle swarm optimization algorithm according to various characteristics of the input data. In addition, to demonstrate its efficacy and applicability, the novel model is utilized to predict China's total and industrial electricity consumption from 2012 to 2014 and then compared to forecasts obtained from a range of benchmark models. The two empirical results illustrate that the novel initial condition with dynamic weighted coefficients can better adjust to the features of electricity consumption data than the previous initial conditions. They also show the superiority of the newly proposed model over the benchmark models. Within this paper, the new model is used for predicting the future values of China's total and industrial electricity consumption from 2015 to 2020.
•A new grey model is designed for forecasting China's electricity consumption.•The novel initial condition possessing alterable weighted coefficients are proposed.•The particle swarm optimization is employed to determine the generating parameters.•The rolling mechanism is combined with the new model to improve accuracy.•The total and industrial electricity consumption are predicted from 2015 to 2020.
Electronic skin (e‐skin) has been under the spotlight due to great potential for applications in robotics, human–machine interfaces, and healthcare. Meanwhile, triboelectric nanogenerators (TENGs) ...have been emerging as an effective approach to realize self‐powered e‐skin sensors. In this work, bioinspired TENGs as self‐powered e‐skin sensors are developed and their applications for robotic tactile sensing are also demonstrated. Through the facile replication of the surface morphology of natural plants, the interlocking microstructures are generated on tribo‐layers to enhance triboelectric effects. Along with the adoption of polytetrafluoroethylene (PTFE) tinny burrs on the microstructured tribo‐surface, the sensitivity for pressure measurement is boosted with a 14‐fold increase. The tactile sensing capability of the TENG e‐skin sensors are demonstrated through the characterizations of handshaking pressure and bending angles of each finger of a bionic hand during handshaking with human. The TENG e‐skin sensors can also be utilized for tactile object recognition to measure surface roughness and discern hardness. The facile fabrication scheme of the self‐powered TENG e‐skin sensors enables their great potential for applications in robotic dexterous manipulation, prosthetics, human–machine interfaces, etc.
Bioinspired triboelectric nanogenerators as self‐powered e‐skin sensors are developed and their applications for robotic tactile sensing are also demonstrated. Through the facile replication of the surface morphology of natural plants, the interlocking microstructures are generated on tribo‐layers to enhance the triboelectric effect. Along with the adoption of polytetrafluoroethylene tinny burrs on the microstructured tribo‐surface, the sensitivity for pressure measurement is boosted, with a 14‐fold increase.
No experiment to date has provided evidence for quantum features of the gravitational interaction. Recently proposed tests suggest looking for the generation of quantum entanglement between massive ...objects as a possible route towards the observation of such features. Motivated by advances in optical cooling of mirrors, here we provide a systematic study of entanglement between two masses that are coupled gravitationally. We first consider the masses trapped at all times in harmonic potentials (optomechanics) and then the masses released from the traps. This leads to the estimate of the experimental parameters required for the observation of gravitationally induced entanglement. The optomechanical setup demands LIGO-like mirrors and squeezing or long coherence times, but the released masses can be light and accumulate detectable entanglement in a timescale shorter than their coherence times. No macroscopic quantum superposition develops during the evolution. We discuss the implications from such thought experiments regarding the nature of the gravitational coupling.
The use of local aluminosilicates to serve the local engineering applications could resolve the issue of unpredicted properties of the geopolymer caused by the wide variance in aluminosilicates ...reactivity. The locally available aluminosilicate byproducts (e.g., fly ash FA and granulated ground blast-furnace slag GGBS) in Qingdao were used to synthesize geopolymer cement in this study. Six geopolymer cement mortars with different FA/GGBS ratios were compared with ordinary Portland cement (OPC) and magnesium potassium phosphate cement (MKPC) mortars in terms of workability, setting time, strength development, volume stability and chloride permeability. The use of high volume of GGBS equips the geopolymer mortars with fast setting and high early strength despite poor volume stability. Thus, GGBS geopolymer mortars could potentially replace the high-cost MKPC mortar for rapid rehabilitation in construction. The geopolymer cement mortar with a FA/GGBS ratio of 4 behaves similar to OPC mortars in terms of fluidity, setting time, strength development, volume stability and chloride permeability. Therefore, FA-based geopolymer mortar blended with 20% GGBS could be considered as a high-efficiency, low-cost, eco-friendly and sustainable replacement of OPC mortar. Overall, the geopolymer cement properties could be engineered based on the FA/GGBS ratio in order to serve local engineering applications for the maximum utilization in different scenarios.
•Engineering-oriented properties of geopolymer mortars were characterized.•FA/GGBS ratio dependent geopolymer cement was compared with OPC and MKPC.•Application cost and prospect of geopolymer cement were analyzed.
Nanofiltration (NF) membranes offer advantages to address enormous demands for textile water treatment. To meet omnipresent challenges of dye/salt selectively and antifouling performance, an ...efficient dye desalting and antifouling NF membrane was developed by virtue of zwitterionic functionalized monomer (zwitterionic N,N-Bis(3-aminopropyl)methylamine, ZDNMA). The structures of zwitterionic membranes can be tailored to suit the separation performance and antifouling property. The prepared zwitterionic NF membrane shows superior removal performance of methyl blue and penetration capacity of NaCl due to zwitterion desirable features of accelerating NaCl transportation. Thus, the membrane selectivity factor for NaCl/methyl blue can be as high as 857.0, accompanied by pure water flux of 10.67 L m-2 h-1 bar-1. When dealing with 0.3 g L-1 MYB and 4 g L-1 NaCl mixture solution, a high NaCl removal was achieved in 75.8% with about 8.1% dye loss after dye purification process. Furthermore, the membrane revealed antifouling performance with a 94.9% flux recovery ratio. The zwitterionic NF membrane highlights more exceptional dye desalination performance, which renders a vast potential for practical textile effluent.
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•Zwitterion was synthesized to prepared NF membrane by interfacial polymerization.•The effect of zwitterion concentration on membrane performance was investigated.•Zwitterionic NF membrane possessed enhanced hydrophilicity and water permeability.•Excellent salt/dye separation and superior antifouling performance were realized.
Objectives
This study aimed to review the results of oral leucoplakia (OL) using ablative fractional laser‐assisted photodynamic therapy (AFL‐PDT) and to further evaluate the risk factors for ...recurrence and malignant transformation.
Materials and Methods
Forty‐eight patients diagnosed with OL using histopathology were enrolled in this study. All patients received one session of AFL‐PDT. Therapeutic efficacy was evaluated 1 month posttreatment. Follow‐up was scheduled every 3 months in the first year and every 6 months thereafter.
Results
An overall positive response rate of 87.5% (42/48) was achieved, including 62.5% (30/48) complete responses and 25.0% (12/48) partial responses. During the 3‐year follow‐up period, the recurrence and malignant transformation rates were 37.5% (18/48) and 8.3% (4/48), respectively. Lesions on gingiva/palate seemed to be associated with recurrence (p < 0.001; odds ratio OR: 1.64, 95% confidence interval CI: 1.13–2.37). The severity of epithelial dysplasia (p = 0.02; OR: 2.93, 95% CI: 1.96–4.42) and recurrence (p = 0.016; OR: 3.14, 95% CI: 2.04–4.84) were associated with a predisposition to malignant transformation.
Conclusions
AFL‐PDT is an effective management of OL, but requires close follow‐up. OL lesions on the gingiva/palate are predisposed to recurrence. OLs that recur with moderate/severe epithelial dysplasia have a higher risk of transforming into oral squamous cell carcinoma.
In this paper, a nonlinear energy sink (NES) and a giant magnetostrictive-piezoelectric (GMP) energy harvester (NES-GMP) are investigated to suppress the nonlinear aeroelastic responses and to absorb ...the mechanical energy of an embedded plate interacting with external subsonic airflow. The analytical model of the embedded plate attaching the NES-GMP is established by using the Hamilton’s principle based on the Kirchhoff plate theory and incompressible subsonic aerodynamic model. The natural frequencies of the plate with the NES-GMP and with the NES are analyzed by solving the generalized eigenvalue problems. The global amplitude-frequency responses of the pure plate, the plate with NES, and the plate with NES-GMP are compared to show the vibration suppression effects of the proposed method. Based on the energy analysis, the energy transfer mechanisms of the plate with the NES-GMP are studied. The results reveal that the input energy of the NES-GMP converts into the strain energy by the Terfenol-D layer and then transforms into the electric energy by the piezoelectric layer. Furthermore, numerical simulations also indicate that the maximum harvested energy is obtained when the airflow velocity approaches the critical divergence flow velocity of the plate, and the most effective harvesting installation position is in a specific annular region near the edge of the plate.
•Microstructural evolution of LPBF 304 L SS at all length scales during annealing was comprehensively investigated.•As-built samples contained the square lattice distortion networks composed of ...orthogonal strain ripples using HRTEM.•High annealing temperature resulted in the unidirectional dislocation migration, which destroyed the as-built square lattice distortion networks.•TKD results disclosed that the local misorientation ranges of cellular interior, cellular walls, and newly formed subgrain boundaries were <0.2°, 0.2°−0.5°, and 0.5°−2°, respectively.•Deformation mechanisms and work hardening behaviors of as-built and annealed LPBF 304 L SS were revealed.
This paper focuses on the microstructural evolution of 304 L austenitic stainless steel (SS) manufactured by laser powder bed fusion (LPBF) after stress-relieving annealing (650 °C) and solution annealing (1050 °C). Multiple advanced characterizations were adopted to disclose the microstructural characteristics and investigate the annealing-driven dislocation migration process. At 650 °C, the dislocation density of cellular walls decreased slightly, associated with a slight decrease of strength. At 1050 °C, the dislocations of cellular walls migrated to more energetically favorable regions, forming subgrain boundaries with higher dislocation density and resulting in a strength-ductility trade-off. The temperature of 1050 °C could slightly increase the recrystallization volume fraction and induce the coalescence of multi-oriented fine-grained tribes into single-oriented grains. The nano-scale characterization indicated that the as-built samples and annealed samples at 650 °C contained the square lattice distortion networks composed of orthogonal strain ripples. However, after annealing at 1050 °C, only unidirectional strain ripples in square lattice distortion networks were retained due to unidirectional dislocation migration. Direct experimental results were provided that the local misorientation ranges of cellular interior, cellular walls, and newly formed subgrain boundaries were <0.2°, 0.2°-0.5°, and 0.5°-2°, respectively. After tensile deformation, interacting deformation twins occurred in and 〈101〉 oriented grains of as-built and annealed specimens at 650 °C, while the twins occurred in all oriented grains of annealed specimens at 1050 °C due to the disappearance of cellular substructure and the increase of tensile elongation. This work yields new insights into misorientation across the cellular walls, dislocation migration process during annealing, strengthening mechanisms, and work hardening behaviors, which can be used to design and optimize future annealing routines for LPBF materials.
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