Coronavirus disease 2019 is a newly emerging infectious disease currently spreading across the world. It is caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 ...(SARS-CoV-2). The spike (S) protein of SARS-CoV-2, which plays a key role in the receptor recognition and cell membrane fusion process, is composed of two subunits, S1 and S2. The S1 subunit contains a receptor-binding domain that recognizes and binds to the host receptor angiotensin-converting enzyme 2, while the S2 subunit mediates viral cell membrane fusion by forming a six-helical bundle via the two-heptad repeat domain. In this review, we highlight recent research advance in the structure, function and development of antivirus drugs targeting the S protein.
Due to the advantages of good scalability, flexibility, low cost, ease of processing, 3D‐stacking capability, and large capacity for data storage, polymer‐based resistive memories have been a ...promising alternative or supplementary devices to conventional inorganic semiconductor‐based memory technology, and attracted significant scientific interest as a new and promising research field. In this review, we first introduced the general characteristics of the device structures and fabrication, memory effects, switching mechanisms, and effects of electrodes on memory properties associated with polymer‐based resistive memory devices. Subsequently, the research progress concerning the use of single polymers or polymer composites as active materials for resistive memory devices has been summarized and discussed. In particular, we consider a rational approach to their design and discuss how to realize the excellent memory devices and understand the memory mechanisms. Finally, the current challenges and several possible future research directions in this field have also been discussed.
In this review we introduce the general characteristics of the device structures and fabrication, memory effects, and switching mechanisms of polymer‐based resistive memory devices. Subsequently, the research progress concerning the use of single polymers or polymer composites as active materials for resistive memory devices are summarized. Finally, current challenges and future research directions in this field are discussed.
Amino groups are common in both natural and synthetic compounds and offer a very attractive class of endogenous handles for bioconjugation. However, the ability to differentiate two types of amino ...groups and join them with high hetero‐selectivity and efficiency in a complex setting remains elusive. Herein, we report a new method for bioconjugation via one‐pot chemoselective clamping of two different amine nucleophiles using a simple ortho‐phthalaldehyde (OPA) reagent. Various α‐amino acids, aryl amines, and secondary amines can be crosslinked to the ϵ‐amino side chain of lysine on peptides or proteins with high efficiency and hetero‐selectivity. This method offers a simple and powerful means to crosslink small molecule drugs, imaging probes, peptides, proteins, carbohydrates, and even virus particles without any pre‐functionalization.
Simple ortho‐phthalaldehyde (OPA) reagent enables a facile and broadly applicable bioconjugation strategy via hetero‐selective clamping of two different endogenous amino handles such as ϵ‐NH2 of lysine and α‐NH2 of α‐amino acids without any pre‐functionalization.
As the core components of insulation systems or film capacitors, polymer dielectrics are widely used in electrical and electronic equipment and for energy storage. However, the electrical strength is ...always the bottleneck that limits further application. Therefore, a coating with a wide bandgap comprising of zinc oxide and polydimethylsiloxane is designed in this paper. Experiments show that the coating effectively improves the breakdown strength and flashover voltage. A Kelvin probe force microscope is used to determine the microscopic mechanism for performance improvement, the charge dissipation characteristics and the changes in trap parameters in the nanoscale regime. This shows that many shallow traps are introduced on the polymer surface after applying the coating, which dissipate the surface charges and increase the flashover voltage. First‐principles calculations indicate that the band gap of the coating is wider than that of the polymer dielectric, which explains the enhancement in breakdown field strength. This paper presents an efficient method for enhancing the electrical strengths of polymer dielectrics, which is crucial for their application. More importantly, the experimental and theoretical methods used to determine the microscopic mechanism and the conclusions obtained in this paper provide guidance for future research on polymer dielectrics.
This paper proposes a wide‐bandgap zinc oxide (ZnO)−polydimethylsiloxane (PDMS) nanocoating that effectively improves the breakdown strengths and flashover voltages of widely used polymer dielectrics. This is essential for insulation systems in electrical and electronic equipment or energy storage film capacitors.
China is one of the countries with the highest incidence of gastric cancer. There are differences in epidemiological characteristics, clinicopathological features, tumor biological characteristics, ...treatment patterns, and drug selection between gastric cancer patients from the Eastern and Western countries. Non‐Chinese guidelines cannot specifically reflect the diagnosis and treatment characteristics for the Chinese gastric cancer patients. The Chinese Society of Clinical Oncology (CSCO) arranged for a panel of senior experts specializing in all sub‐specialties of gastric cancer to compile, discuss, and revise the guidelines on the diagnosis and treatment of gastric cancer based on the findings of evidence‐based medicine in China and abroad. By referring to the opinions of industry experts, taking into account of regional differences, giving full consideration to the accessibility of diagnosis and treatment resources, these experts have conducted experts’ consensus judgement on relevant evidence and made various grades of recommendations for the clinical diagnosis and treatment of gastric cancer to reflect the value of cancer treatment and meeting health economic indexes. This guideline uses tables and is complemented by explanatory and descriptive notes covering the diagnosis, comprehensive treatment, and follow‐up visits for gastric cancer.
Abstract
Effecting the synergistic function of single metal atom sites and their supports is of great importance to achieve high-performance catalysts. Herein, we successfully fabricate ...polyoxometalates (POMs)-stabilized atomically dispersed platinum sites by employing three-dimensional metal-organic frameworks (MOFs) as the finite spatial skeleton to govern the accessible quantity, spatial dispersion, and mobility of metal precursors around each POM unit. The isolated single platinum atoms (Pt
1
) are steadily anchored in the square-planar sites on the surface of monodispersed Keggin-type phosphomolybdic acid (PMo) in the cavities of various MOFs, including MIL-101, HKUST-1, and ZIF-67. In contrast, either the absence of POMs or MOFs yielded only platinum nanoparticles. Pt
1
-PMo@MIL-101 are seven times more active than the corresponding nanoparticles in the diboration of phenylacetylene, which can be attributed to the synergistic effect of the preconcentration of organic reaction substrates by porous MOFs skeleton and the decreased desorption energy of products on isolated Pt atom sites.
Phosphorescent manganese(II) complexes are emerging as a new generation of phosphorescent materials showing great potentials in many applications, owing to their unique features including highly ...efficient phosphorescence, diverse structural/molecular design, and ease of synthesis, structural diversity, rich physical properties (e.g., triboluminescence, stimuli‐responsivity, etc.), high abundance, and low cost. The research on phosphorescent manganese(II) complexes is just in its infancy but rapidly flourishing indeed, and their potential applications are also emerging in many aspects. Herein, the recent progress on the molecular design of new manganese(II) complex‐based materials, mechanism of phosphorescence, photophysical properties, and their representative applications is highlighted, which covers topics such as: i) structural features and photophysics of phosphorescent manganese(II) complexes; ii) molecular design strategies of phosphorescent manganese(II) complexes (e.g., neutral complexes, ionic complexes, coordination polymers, and other types of complexes); and iii) their emerging applications in the fields of organic electroluminescence, information recording and security protection, temperature sensors. Finally, some perspectives together with future research focus of the field are described.
Compared with the noble metals, manganese has abundant reserves, is environmentally friendly, and inexpensive. Phosphorescent manganese(II) complexes are emerging as a new generation of phosphorescent materials with great potential in many application areas. An overview of the molecular design, synthesis, photophysics, and recent research progress on phosphorescent manganese(II) complexes and their emerging applications is provided.
•Design strategies of g-C3N4 polymer photocatalyst are reviewed.•High stability and non-toxic are the characteristics of g-C3N4.•Advantages and applications of g-C3N4 in photocatalysis are summarized ...in detail.•Methods for improving photocatalytic performances of g-C3N4 are discussed.•Challenges of large-scale application of g-C3N4 based on photocatalysts are presented.
Graphitic carbon nitride (g-C3N4) is an excellent polymer photocatalyst to revolutionize the semiconductor field and deprive solar photons from their energies for conversion into chemical energy resulting in degradation of a number of hazardous organic pollutants into harmless compounds. g-C3N4 has fortified its applications in the field of photocatalysis due to its unique nature including high chemical stability, non-toxic and suitable position of energy band. However, its relatively low visible light absorption, quick recombination of excited charges and low surface area have over shaded its full-fledged efficiency in the above mentioned fields. In this review, we have highlighted its advantages and applications in the field of photocatalysis and provided an updated discussion on the different ways to improve its efficiency, especially its visible light absorption and excited charge separation.
Transition metal doped ZnO (TM-ZnO) nanoparticles with 3% dopant content are successfully prepared via a simple solvothermal route. This work highlights Mn, Fe, Co, Ni or Cu ions as the dopant ...transition metals. The as-prepared samples are wurtzite phase ZnO crystals, and the average sizes of undoped ZnO and TM-ZnO nanoparticles range from 200 nm to 400 nm. XPS studies confirm that the transition metal ions are successfully doped into the crystal lattice of ZnO. The band gaps of the undoped ZnO and TM-ZnO crystals are calculated by using UV-DRS spectroscopic measurements. The visible light response of ZnO nanomaterials is improved by doping transition metal ions. For investigating the influence of transition metal doping on the photocatalytic performance of ZnO, the photodegradation rate of methylene blue (MB) is investigated under simulated sunlight irradiation. The photocatalytic properties of ZnO doped with transition metals are improved at different degrees, among which Cu-doped ZnO exhibits the best photocatalytic performance. Based on density functional theory (DFT) calculation result, a possible photocatalytic mechanism is proposed. Furthermore, the antibacterial performance of Cu-doped ZnO is investigated by selecting E. coli, under simulated sunlight irradiation and remarkable sterilization of E. coli is achieved.
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•Transition metal doped ZnO nanoparticles were successfully prepared.•The visible light response of ZnO nanomaterials was improved.•The photocatalytic activities of ZnO doped with transition metals were improved.•Cu-doped ZnO shows remarkable sterilization of E. coli.
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