Starting from the spring of 2020, the outbreak of the COVID‐19 caused Chinese universities to close the campuses and forced them to initiate online teaching. This paper focuses on a case of Peking ...University's online education. Six specific instructional strategies are presented to summarize current online teaching experiences for university instructors who might conduct online education in similar circumstances. The study concludes with five high‐impact principles for online education: (a) high relevance between online instructional design and student learning, (b) effective delivery on online instructional information, (c) adequate support provided by faculty and teaching assistants to students; (d) high‐quality participation to improve the breadth and depth of student's learning, and (e) contingency plan to deal with unexpected incidents of online education platforms.
We report FeOOH supported on Ni foam which enables highly efficient UOR electrocatalysis and can be readily produced through a hydrolysis reaction. Our developed UOR catalyst as the anode can provide ...a current density of 200 mA cm
−2
at 1.427 V
vs.
RHE, as well as remarkable operational stability, representing the best yet reported noble metal-free urea electrolyser.
The developed UOR electrocatalyst as the anode can provide a current density of 200 mA cm
−2
at 1.427 V
vs.
RHE, as well as remarkable operational stability.
The application of deep learning approaches to finance has received a great deal of attention from both investors and researchers. This study presents a novel deep learning framework where wavelet ...transforms (WT), stacked autoencoders (SAEs) and long-short term memory (LSTM) are combined for stock price forecasting. The SAEs for hierarchically extracted deep features is introduced into stock price forecasting for the first time. The deep learning framework comprises three stages. First, the stock price time series is decomposed by WT to eliminate noise. Second, SAEs is applied to generate deep high-level features for predicting the stock price. Third, high-level denoising features are fed into LSTM to forecast the next day's closing price. Six market indices and their corresponding index futures are chosen to examine the performance of the proposed model. Results show that the proposed model outperforms other similar models in both predictive accuracy and profitability performance.
CaO–Al2O3–MgO–SiO2 (CAMS)‐based glass‐ceramics were prepared using body crystallization method. Adding Cr2O3 into the ceramics not only effectively lowered the crystallization temperature, but also ...led to significant grain refinement of diopside that crystallized in the CAMS glass‐ceramic after crystallization treatment at 900°C for 2 hours. Experimental work verified that the epitaxial growth of the diopside on the spinel particles, which formed during nucleation treatment when fabricating the glass‐ceramics, facilitated the heterogeneous nucleation of diopside on the spinel and refined the diopside. In addition, two energetically favored crystallographic orientation relationships between the epitaxial growth diopside and spinel were experimentally observed. They are 1¯12spinel//001diopside,//(11¯1)spinel//(200)diopside and 1¯12spinel//101diopside, (311)spinel//(131¯)diopside. These two novel results can be potentially used to develop new glass‐ceramic materials with improved performance.
This study estimates the current prevalence of autism spectrum disorder among US children
and adolescents from 2014 to 2016 using nationally representative data from the National
Health Interview ...Survey.
Tuberculosis (TB) kills more individuals in the world than any other disease, and a threat made direr by the coverage of drug-resistant strains of Mycobacterium tuberculosis (Mtb). Bacillus ...Calmette-Guérin (BCG) is the single TB vaccine licensed for use in human beings and effectively protects infants and children against severe military and meningeal TB. We applied advanced computational techniques to develop a universal TB vaccine. In the current study, we select the very conserved, experimentally confirmed Mtb antigens, including Rv2608, Rv2684, Rv3804c (Ag85A), and Rv0125 (Mtb32A) to design a novel multi-epitope subunit vaccine. By using the Immune Epitopes Database (IEDB), we predicted different B-cell and T-cell epitopes. An adjuvant (Griselimycin) was also added to vaccine construct to improve its immunogenicity. Bioinformatics tools were used to predict, refined, and validate the 3D structure and then docked with toll-like-receptor (TLR-3) using different servers. The constructed vaccine was used for further processing based on allergenicity, antigenicity, solubility, different physiochemical properties, and molecular docking scores. The in silico immune simulation results showed significant response for immune cells. For successful expression of the vaccine in E. coli, in-silico cloning and codon optimization were performed. This research also sets out a good signal for the design of a peptide-based tuberculosis vaccine. In conclusion, our findings show that the known multi-epitope vaccine may activate humoral and cellular immune responses and maybe a possible tuberculosis vaccine candidate. Therefore, more experimental validations should be exposed to it.
In 2008, a new class of pillar-shaped supramolecular macrocyclic hosts was reported, known as "pillararenes". Their particular electron-rich cavity and the ease of their functionalization offer ...possibilities for the design and synthesis of novel fluorescent chemosensors. Subsequently, pillararene-based fluorescent sensors and probes have been rapidly developed. This feature article covers the most recent contributions from the pillararene-based fluorescent sensor field in terms of anion/cation sensing, small molecule recognition, biomolecule detection, fluorescent supramolecular aggregates, and biomedical imaging. Meanwhile, we hope that this feature article will inspire more effort to be devoted to this emerging field.
This feature article summarizes recent research in the pillararene-based fluorescent chemosensor field in terms of ion sensing, small molecule recognition, biomolecule detection, fluorescent supramolecular aggregates, and biomedical imaging.
Chiral macrocycles possess significant value in chiral science and supramolecular chemistry. Pillararenes, as a class of relatively young supramolecular macrocyclic hosts, have been widely used for ...host-guest recognition and self-assembly. Since the position of substituents on the benzene rings breaks the molecular symmetry (symmetric plane and symmetric center), pillararenes possess planar chirality. However, it is a great challenge to synthesize stable and resolvable enantiomers because of the easy rotation of the phenylene group. In this review, we summarize the construction methods of resolvable chiral pillararenes. We also focus on their applications in enantioselective recognition, chiral switches, chirality sensing, asymmetric catalysis, circularly polarized luminescence, metal-organic frameworks, and highly permeable membranes. Finally, we discuss the future research perspectives in this field of pillararene-based planar chiral materials. We hope that this review will encourage more researchers to work in this exciting field.
This review overviews recent research in the planar chiral pillararene field in terms of enantioselective recognition, chiral switches, chirality sensing, asymmetric catalysis, metal-organic frameworks, circularly polarized luminescence, and permeable membranes.
Horizontal and vertical handoffs are important ramifications of user mobility in multitier heterogeneous wireless networks. They directly impact the signaling overhead and quality of calls. However, ...they are difficult to analyze due to the irregularly shaped network topologies introduced by multiple tiers of cells. In this paper, a stochastic geometric analysis framework on user mobility is proposed, to capture the spatial randomness and various scales of cell sizes in different tiers. We derive theoretical expressions for the rates of all handoff types experienced by an active user with arbitrary movement trajectory. Furthermore, noting that the data rate of a user depends on the set of cell tiers that it is willing to use, we provide guidelines for optimal tier selection under various user velocities, taking both the handoff rates and the data rate into consideration. Empirical studies using user mobility trace data and extensive simulation are conducted, demonstrating the correctness and usefulness of our analysis.
PDF
