Herein, an effective tandem catalysis strategy is developed to improve the selectivity of the CO2RR towards C2H4 by multiple distinct catalytic sites in local vicinity. An earth‐abundant ...elements‐based tandem electrocatalyst PTF(Ni)/Cu is constructed by uniformly dispersing Cu nanoparticles (NPs) on the porphyrinic triazine framework anchored with atomically isolated nickel–nitrogen sites (PTF(Ni)) for the enhanced CO2RR to produce C2H4. The Faradaic efficiency of C2H4 reaches 57.3 % at −1.1 V versus the reversible hydrogen electrode (RHE), which is about 6 times higher than the non‐tandem catalyst PTF/Cu, which produces CH4 as the major carbon product. The operando infrared spectroscopy and theoretic density functional theory (DFT) calculations reveal that the local high concentration of CO generated by PTF(Ni) sites can facilitate the C−C coupling to form C2H4 on the nearby Cu NP sites. The work offers an effective avenue to design electrocatalysts for the highly selective CO2RR to produce multicarbon products via a tandem route.
An effective tandem catalysis strategy is developed to enhance the selectivity of the CO2 electroreduction reaction towards C2H4 with a 6‐fold increase in comparison with that of the non‐tandem catalysts. The local high concentration of CO generated by atomically isolated nickel–nitrogen sites PTF(Ni) sites can facilitate the C−C coupling to form C2H4 on the nearby Cu NP sites, thus switching from CH4 to C2H4 production with a Faradaic efficiency of 57.3 %.
Exploiting Zn metal‐free anode materials would be an effective strategy to resolve the problems of Zn metal dendrites that severely hinder the development of Zn ion batteries (ZIBs). However, the ...study of Zn metal‐free anode materials is still in their infancy, and more importantly, the low energy density severely limits their practical implementations. Herein, a novel (NH4)2V10O25 · 8H2O@Ti3C2Tx (NHVO@Ti3C2Tx) film anode is proposed and investigated for constructing “rocking‐chair” ZIBs. The NHVO@Ti3C2Tx electrode shows a capacity of 514.7 mAh g−1 and presents low potential which is 0.59 V (vs Zn2+/Zn) at 0.1 A g−1. The introduction of Ti3C2Tx not only affords an interconnected conductive network, but also stabilizes the NHVO nanobelts structure for a long cycle life (84.2% retention at 5.0 A g−1 over 6000 cycles). As a proof‐of‐concept, a zinc metal‐free full battery is successfully demonstrated, which delivers the highest capacity of 131.7 mAh g−1 (mass containing anodic and cathodic) and energy density of 97.1 Wh kg−1 compared to all reported aqueous “rocking‐chair” ZIBs. Furthermore, a long cycling span of 6000 cycles is obtained with capacity retention reaching up to 92.1%, which is impressive. This work is expected to provide new moment toward V‐based materials for “rocking‐chair” ZIBs.
A novel (NH4)2V10O25 · 8H2O@Ti3C2Tx (NHVO@Ti3C2Tx) film anode is proposed and investigated for constructing “rocking‐chair” zinc ion batteries (ZIBs). Due to good crystal and electrode structure engineering, the hybrid electrode exhibits superior electrochemical performance with a low potential (vs Zn2+/Zn). By pairing the NHVO@ Ti3C2Tx film anode and ZnMn2O4 cathode, the Zn‐ion full battery can deliver remarkable specific capacity and energy density.
Abstract
MicroRNAs (miRNAs) are noncoding RNAs with 18–26 nucleotides; they pair with target mRNAs to regulate gene expression and produce significant changes in various physiological and ...pathological processes. In recent years, the interaction between miRNAs and their target genes has become one of the mainstream directions for drug development. As a large-scale biological database that mainly provides miRNA–target interactions (MTIs) verified by biological experiments, miRTarBase has undergone five revisions and enhancements. The database has accumulated >2 200 449 verified MTIs from 13 389 manually curated articles and CLIP-seq data. An optimized scoring system is adopted to enhance this update’s critical recognition of MTI-related articles and corresponding disease information. In addition, single-nucleotide polymorphisms and disease-related variants related to the binding efficiency of miRNA and target were characterized in miRNAs and gene 3′ untranslated regions. miRNA expression profiles across extracellular vesicles, blood and different tissues, including exosomal miRNAs and tissue-specific miRNAs, were integrated to explore miRNA functions and biomarkers. For the user interface, we have classified attributes, including RNA expression, specific interaction, protein expression and biological function, for various validation experiments related to the role of miRNA. We also used seed sequence information to evaluate the binding sites of miRNA. In summary, these enhancements render miRTarBase as one of the most research-amicable MTI databases that contain comprehensive and experimentally verified annotations. The newly updated version of miRTarBase is now available at https://miRTarBase.cuhk.edu.cn/.
In the present work a nickel-base superalloy Inconel 718 manufactured by selective laser melting (SLM) was investigated with focus on microstructure, orientation-dependent mechanical property and ...fatigue performance. Comparative material testing and characterization of the SLM and the forged Inconel 718 revealed significant differences in both microstructures and mechanical properties. The columnar grain structure of SLM alloy leads to the orientation-dependent mechanical properties, which matches the Hall-Petch relation. The inhomogeneous microstructures and slit shaped lack-of-fusion (LoF) defects from the SLM process result in worse fatigue performance and deteriorate the fatigue crack growth behavior.
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs (typically consisting of 18–25 nucleotides) that negatively control expression of target genes at the post-transcriptional level. Owing to the ...biological significance of miRNAs, miRTarBase was developed to provide comprehensive information on experimentally validated miRNA–target interactions (MTIs). To date, the database has accumulated >13,404 validated MTIs from 11,021 articles from manual curations. In this update, a text-mining system was incorporated to enhance the recognition of MTI-related articles by adopting a scoring system. In addition, a variety of biological databases were integrated to provide information on the regulatory network of miRNAs and its expression in blood. Not only targets of miRNAs but also regulators of miRNAs are provided to users for investigating the up- and downstream regulations of miRNAs. Moreover, the number of MTIs with high-throughput experimental evidence increased remarkably (validated by CLIP-seq technology). In conclusion, these improvements promote the miRTarBase as one of the most comprehensively annotated and experimentally validated miRNA–target interaction databases. The updated version of miRTarBase is now available at http://miRTarBase.cuhk.edu.cn/.
The genus
is a member of the Celastraceae family, of which several species have long been used in traditional medicine. Between 1976 and 2021, nearly 270 new compounds have been isolated and ...elucidated from the genus
. Among these, maytansine and its homologues are extremely rare in nature. Owing to its unique skeleton and remarkable bioactivities, maytansine has attracted many synthetic endeavors in order to construct its core structure. In this paper, the current status of the past 45 years of research on
, with respect to its chemical and biological activities are discussed. The chemical research includes its structural classification into triterpenoids, sesquiterpenes and alkaloids, along with several chemical synthesis methods of maytansine or maytansine fragments. The biological activity research includes activities, such as anti-tumor, anti-bacterial and anti-inflammatory activities, as well as HIV inhibition, which can provide a theoretical basis for the better development and utilization of the
.
A redox road to recoveryDevice longevity is a key issue for organic-inorganic perovskite solar cells. Encapsulation can limit degradation arising from reactions with oxygen and water, but light, ...electric-field, and thermal stresses can lead to metastable elemental lead and halide atom defects. Wang et al. show that for the lead-iodine system, the introduction of the rare earth europium ion pair Eu3+-Eu2+ can shuttle electrons and recover lead and iodine ions (Pb2+ and I−). Devices incorporating this redox shuttle maintained more than 90% of their initial power conversion efficiencies under various aging conditions.Science, this issue p. 265The components with soft nature in the metal halide perovskite absorber usually generate lead (Pb)0 and iodine (I)0 defects during device fabrication and operation. These defects serve as not only recombination centers to deteriorate device efficiency but also degradation initiators to hamper device lifetimes. We show that the europium ion pair Eu3+-Eu2+ acts as the “redox shuttle” that selectively oxidized Pb0 and reduced I0 defects simultaneously in a cyclical transition. The resultant device achieves a power conversion efficiency (PCE) of 21.52% (certified 20.52%) with substantially improved long-term durability. The devices retained 92% and 89% of the peak PCE under 1-sun continuous illumination or heating at 85°C for 1500 hours and 91% of the original stable PCE after maximum power point tracking for 500 hours, respectively.
Abstract
Sepsis is a common complication of combat injuries and trauma, and is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. It is also one of ...the significant causes of death and increased health care costs in modern intensive care units. The use of antibiotics, fluid resuscitation, and organ support therapy have limited prognostic impact in patients with sepsis. Although its pathophysiology remains elusive, immunosuppression is now recognized as one of the major causes of septic death. Sepsis-induced immunosuppression is resulted from disruption of immune homeostasis. It is characterized by the release of anti-inflammatory cytokines, abnormal death of immune effector cells, hyperproliferation of immune suppressor cells, and expression of immune checkpoints. By targeting immunosuppression, especially with immune checkpoint inhibitors, preclinical studies have demonstrated the reversal of immunocyte dysfunctions and established host resistance. Here, we comprehensively discuss recent findings on the mechanisms, regulation and biomarkers of sepsis-induced immunosuppression and highlight their implications for developing effective strategies to treat patients with septic shock.
PurposeMoyamoya disease (MMD) is an uncommon chronic and occlusive cerebrovascular disorder involving the development of abnormal collateral vessels. This report aimed to describe a Chinese familial ...case with a rare variant in the RNF213 gene.MethodsThe present report presents a rare familial case of MMD involving a heterozygous c.14429G>A variant in RNF213 and exhibiting different phenotypes.ResultsA 3-year-old Chinese boy and his 10-year-old sister diagnosed severe bilateral MMD, while their mother was diagnosed asymptomatic bilateral MMD, based on the imaging results of magnetic resonance angiography (MRA). The boy mainly showed numbness at left hand accompanied by dysphasia and dyskinesia, while his sister had complex symptoms including dysphasia, dyskinesia at both hands and fatigue of limbs. Muscle force was ranked as left (upper limb/lower limb: 4/3) and right (upper limb/lower limb: 3/4). Genetic testing indicated a heterozygous c.14429G>A variant in RNF213 in 3 patients. The 3 patients shared the same amino acid substitution of p.Arg4810Lys caused by c.14429G>A. The father of two children also underwent genetic testing for RNF213 and MRI examination but found normal in all indices.ConclusionsGenetic testing for RNF213 is suggested for MMD screening towards family members, and c.14576G>A variant is identified as an important pathogenic mutation with family heritability.
Two-dimensional materials provide extraordinary opportunities for exploring phenomena arising in atomically thin crystals. Beginning with the first isolation of graphene, mechanical exfoliation has ...been a key to provide high-quality two-dimensional materials, but despite improvements it is still limited in yield, lateral size and contamination. Here we introduce a contamination-free, one-step and universal Au-assisted mechanical exfoliation method and demonstrate its effectiveness by isolating 40 types of single-crystalline monolayers, including elemental two-dimensional crystals, metal-dichalcogenides, magnets and superconductors. Most of them are of millimeter-size and high-quality, as shown by transfer-free measurements of electron microscopy, photo spectroscopies and electrical transport. Large suspended two-dimensional crystals and heterojunctions were also prepared with high-yield. Enhanced adhesion between the crystals and the substrates enables such efficient exfoliation, for which we identify a gold-assisted exfoliation method that underpins a universal route for producing large-area monolayers and thus supports studies of fundamental properties and potential application of two-dimensional materials.
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