Due to unique redox property, visible light photoredox catalysis is emerging as a powerful tool in synthetic organic chemistry. This review summarizes the previous researches employing visible light ...photoredox catalysts for difunctionalization of alkenes. Display omitted
Due to unique redox property, visible light photoredox catalysis is emerging as a powerful tool in synthetic organic chemistry. This review summarizes the previous researches employing visible light photoredox catalysts for difunctionalization of alkenes.
The real-time TaqMan RT-PCR assay (
Pang et al., 2004) did not detect 14 clinical samples with rotavirus G2 genotype. Three to five nucleotides (nt) were found to be mismatched between the published ...forward primer when compared to G2P4, G2P8, G3P4, G9P4, G8 and G12 sequences. An additional forward primer was designed and included in a modified assay to test the 14 clinical samples and 12 samples with known rotavirus G and P genotypes. The modified assay has improved significantly the sensitivity for specific rotavirus strains without affecting the detection of other genotypes, creating a molecular assay with broad detection of various genotypes of group A rotaviruses.
Potassium ion batteries (KIBs) have emerged as a promising energy storage system, but the stability and high rate capability of their electrode materials, particularly carbon as the most investigated ...anode ones, become a primary challenge. Here, it is identified that pitch‐derived soft carbon, a nongraphitic carbonaceous species which is paid less attention in the battery field, holds special advantage in KIB anodes. The structural flexibility of soft carbon makes it convenient to tune its crystallization degree, thereby modulating the storage behavior of large‐sized K+ in the turbostratic carbon lattices to satisfy the need in structural resilience, low‐voltage feature, and high transportation kinetics. It is confirmed that a simple thermal control can produce structurally optimized soft carbon that has much better battery performance than its widely reported carbon counterparts such as graphite and hard carbon. The findings highlight the potential of soft carbon as an interesting category suitable for high‐performance KIB electrode and provide insights for understanding the complicated K+ storage mechanisms in KIBs.
The cycling stability of anode materials in potassium‐ion batteries (KIBs) is challenged by the large size of K+ itself. The findings not only demonstrate the promising potential of soft carbon as a category suitable for high‐performance KIB electrodes, but also provide insights into the complicated K+ storage mechanisms in carbon anodes of KIBs.
Organelle phylogenomic analysis requires precisely constructed multi-gene alignment matrices concatenated by pre-aligned single gene datasets. For non-bioinformaticians, it can take days to weeks to ...manually create high-quality multi-gene alignments comprising tens or hundreds of homologous genes. Here, we describe a new and highly efficient pipeline, HomBlocks, which uses a homologous block searching method to construct multiple sequence alignment. This approach can automatically recognize locally collinear blocks among organelle genomes and excavate phylogenetically informative regions to construct multiple sequence alignment in a few hours. In addition, HomBlocks supports organelle genomes without annotation and makes adjustment to different taxon datasets, thereby enabling the inclusion of as many common genes as possible. Topology comparison of trees built by conventional multi-gene and HomBlocks alignments implemented in different taxon categories shows that the same efficiency can be achieved by HomBlocks as when using the traditional method. The availability of Homblocks makes organelle phylogenetic analyses more accessible to non-bioinformaticians, thereby promising to lead to a better understanding of phylogenic relationships at an organelle genome level.
HomBlocks is implemented in Perl and is supported by Unix-like operative systems, including Linux and macOS. The Perl source code is freely available for download from https://github.com/fenghen360/HomBlocks.git, and documentation and tutorials are available at https://github.com/fenghen360/HomBlocks.
Contact: yxmao@ouc.edu.cn or fenghen360@126.com
•HomBlocks is a highly efficient and easy-to-use pipeline for organelle phylogenomics based on homologous blocks searching.•Instead of genes, locally collinear blocks among organelle genomes are recognized for constructing multi-sequence alignments.•Non-coding regions, unannotated coding genes and rRNA genes are taken into account for reconstructing the phylogenetic tree.•HomBlocks will potentially facilitate a better understanding of phylogenic relationships at the organelle genome level.
People widely use permanent magnet brushless DC motors because of their simple structure, high operating efficiency, simple control, and easy maintenance. This paper constructs an EFID sensor network ...by merging EFID and sensor technologies and then designs the motor’s intelligent control system and strategy around it. In this paper, the SVR-PSO algorithm is used to localize the motor rotor, which nonlinear SVR trains to construct a nonlinear system of equations for calculating the position of the target tag, and then the PSO algorithm is used to seek the position coordinates of the target tag. The fuzzy PID is utilized to control the brushless DC motor, and the integral separation method is adopted to improve the control strategy. The SVR-PSO positioning algorithm and the improved fuzzy PID control strategy are applied and analyzed. For 12 tags to be measured, the positioning accuracy of SVR-PSO has improved by 56.8% compared to that of LANDMARC. Although SVR-PSO’s positioning algorithm is influenced by mutual coupling and multipath effects, the overall accuracy is still superior to that of LANDMARC. Based on the fuzzy PID controller optimized by the integral separation method, the motor rotational speed has a fast response, a small overshoot, and a small fluctuation of rotational speed, and can automatically regulate and restore stability under the situation of a sudden change of load. The motor speed response is fast, the overshoot is small, and the speed fluctuation is small, and the motor speed can be automatically adjusted and stabilized under the sudden load change, which has better dynamic and static performance than the traditional PID controller and fuzzy PID controller. The purpose of this paper is to provide a strategy reference for the use of RFID technology in the intelligent control of motors.
Due to the obvious advantage in potassium reserves, potassium‐ion batteries (PIBs) are now receiving increasing research attention as an alternative energy storage system for lithium‐ion batteries ...(LIBs). Unfortunately, the large size of K+ makes it a challenging task to identify suitable electrode materials, particularly cathode ones that determine the energy density of PIBs, capable of tolerating the serious structural deformation during the continuous intercalation/deintercalation of K+. It is therefore of paramount importance that proper design principles of cathode materials be followed to ensure stable electrochemical performance if a practical application of PIBs is expected. Herein, the current knowledge on the structural engineering of cathode materials acquired during the battle against its performance degradation is summarized. The K+ storage behavior of different types of cathodes is discussed in detail and the structure–performance relationship of materials sensitive to their different lattice frameworks is highlighted. The key issues facing the future development of different categories of cathode materials are also highlighted and perspectives for potential approaches and strategies to promote the further development of PIBs are provided.
Potassium‐ion batteries (PIBs) are now receiving increasing research attention due to their obvious advantage regarding the potassium reserves. Cathode materials, which determine the energy density of PIBs, usually suffer from serious structural deformation during continuous K+ (de)intercalation. Therefore, proper structural‐design principles of cathode materials should be focused on to ensure high performance to promote the further development of PIBs.
The pandemic of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been posing great threats to the world in many aspects. Effective therapeutic and preventive approaches ...including drugs and vaccines are still unavailable although they are in development. Comprehensive understandings on the life logic of SARS-CoV-2 and the interaction of the virus with hosts are fundamentally important in the fight against SARS-CoV-2. In this review, we briefly summarized the current advances in SARS-CoV-2 research, including the epidemic situation and epidemiological characteristics of the caused disease COVID-19. We further discussed the biology of SARS-CoV-2, including the origin, evolution, and receptor recognition mechanism of SARS-CoV-2. And particularly, we introduced the protein structures of SARS-CoV-2 and structure-based therapeutics development including antibodies, antiviral compounds, and vaccines, and indicated the limitations and perspectives of SARS-CoV-2 research. We wish the information provided by this review may be helpful to the global battle against SARS-CoV-2 infection.
Black phosphorus (BP) is a desirable anode material for alkali metal ion storage owing to its high electronic/ionic conductivity and theoretical capacity. In‐depth understanding of the redox ...reactions between BP and the alkali metal ions is key to reveal the potential and limitations of BP, and thus to guide the design of BP‐based composites for high‐performance alkali metal ion batteries. Comparative studies of the electrochemical reactions of Li+, Na+, and K+ with BP were performed. Ex situ X‐ray absorption near‐edge spectroscopy combined with theoretical calculation reveal the lowest utilization of BP for K+ storage than for Na+ and Li+, which is ascribed to the highest formation energy and the lowest ion diffusion coefficient of the final potassiation product K3P, compared with Li3P and Na3P. As a result, restricting the formation of K3P by limiting the discharge voltage achieves a gravimetric capacity of 1300 mAh g−1 which retains at 600 mAh g−1 after 50 cycles at 0.25 A g−1.
Into the black: The energy‐storage properties of black phosphorus are reported for Li/Na/K ion batteries. BP shows the lowest utilization for K+ storage than for Na+ and Li+, which is ascribed to the highest formation energy and the lowest ion diffusion coefficient of the final potassiation product K3P compared with Li3P and Na3P.
•The antibacterial activity of fucoidans from Laminaria japonica was evaluated.•The unprocessed fucoidans did not exhibit obvious antibacterial activity.•The depolymerized fucoidans exhibited ...excellent antibacterial activity.•Low molecular weight and strong anionic property improve antibacterial activity.•Depolymerized fucoidans inhibit bacterial growth by destroying membrane integrity.
Fucoidans, sulfated polysaccharides in brown algae, were depolymerized though high-pressure hydrolysis, and their antibacterial activity, structural properties, and antibacterial mechanisms were investigated in this work. The fucoidans from Laminaria japonica show no antibacterial activity before depolymerization; however, their depolymerized products can effectively (p<0.05) inhibit the proliferation of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The structure–activity study demonstrated that lower molecular weight and stronger polyanionic property can promote the antibacterial activity. And the depolymerized fucoidans exhibited better antibacterial activity against E. coli than against S. aureus. The results also indicated that the bactericidal pathway of depolymerized fucoidans should be through destruction of the cytomembranes and the target molecules are the membrane proteins, which can result in changed membrane fluidity and/or activated autophagocytosis. Therefore, the depolymerized fucoidans possess potential appliance values in partly or totally replacing antibiotics in our daily life.
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