High-entropy alloy catalysts:From bulk to nano toward highly efficient carbon and nitrogen catalysis

High-entropy alloys(HEAs)have attracted widespread attention as both structural and functional materials owing to their huge multielement composition space and unique high-entropy mixing structure.Recently,emerging HEAs,either in nano or highly porous bulk forms,are developed and utilized for various catalytic and clean energy applications with superior activity and remarkable durability.Being catalysts,HEAs possess some unique advantages,including(1)a multielement composition space for the discovery of new catalysts and fine-tuning of surface adsorption(i.e.,activity and selectivity),(2)diverse active sites derived from the random multielement mixing that are especially suitable for multistep catalysis,and(3)a high-entropy stabilized structure that improves the structural durability in harsh catalytic environments.Benefited from these inherent advantages,HEA catalysts have demonstrated superior catalytic performances and are promising for complex carbon(C)and nitrogen(N)cycle reactions featuring multistep reaction pathways and many different intermediates.However,the design,synthesis,characterization,and understanding of HEA catalysts for C-and N-involved reactions are extremely challenging because of both complex high-entropy materials and complex reactions.In this review,we present the recent development of HEA catalysts,particularly on their innovative and extensive syntheses,advanced(in situ)characterizations,and applications in complex C and N looping reactions,aiming to provide a focused view on how to utilize intrinsically complex catalysts for these important and complex reactions.In the end,remaining challenges and future directions are proposed to guide the development and application of HEA catalysts for highly efficient energy storage and chemical conversion toward carbon neutrality.

Herbal decoctosome is a novel form of medicine

Traditionally, herbal medicine is consumed by drinking decoctions produced by boiling herbs with water. The functional components of the decoction are heat stable. Small RNAs(sRNAs) were reported as a new class of functional components in decoctions. However, the mechanisms by which sRNAs survive heat treatment of the decoction and enter cells are unclear.Previous studies showed that plant-derived exosome-like nanoparticles(ELNs), which we call botanosomes, could deliver therapeutic reagents in vivo. Here, we report that heat-stable decoctosomes(ELNs) from decoctions have more therapeutic effects than the decoctions in vitro and demonstrate therapeutic efficacy in vivo. Furthermore, sRNAs, such as HJT-sRNA-m7 and PGY-sRNA-6, in the decoctosome exhibit potent anti-fibrosis and anti-inflammatory effects, respectively. Decoctosome is comprised of lipids, chemical compounds, proteins, and s RNAs. A medical decoctosome mimic is called bencaosome. A single lipid sphinganine(d22:0) identified in the decoctosome was mixed and heated with the synthesized sRNAs to form the simplest bencaosome. This simple bencaosome structure was identified by critical micelle concentration(cmc) assay that sRNAs coassembled with sphinganine(d22:0) to form the lipid layers of vesicles. The heating process facilitates co-assembly of sRNAs and sphinganine(d22:0) until a steady state is reached. The artificially produced sphinganine-HJT-sRNA-m7 and sphinganinePGY-sRNA-6 bencaosomes could ameliorate bleomycin-induced lung fibrosis and poly(I:C)-induced lung inflammation, respectively, following oral administration in mice. Our study not only demonstrates that the herbal decoctosome may represent a combinatory remedy in precision medicine but also provides an effective oral delivery route for nucleic acid therapy.

Trends in the biological functions and medical applications of extracellular vesicles and analogues

Natural extracellular vesicles(EVs)play important roles in many life processes such as in the intermolecular transfer of substances and genetic information exchanges.Investigating the origins and working mechanisms of natural EVs may provide an understanding of life activities,especially regarding the occurrence and development of diseases.Additionally,due to their vesicular structure,EVs(in small molecules,nucleic acids,proteins,etc.)could act as efficient drug-delivery carriers.Herein,we describe the sources and biological functions of various EVs,summarize the roles of EVs in disease diagnosis and treatment,and review the application of EVs as drug-delivery carriers.We also assess the challenges and perspectives of EVs in biomedical applications.

Erratum to:Herbal decoctosome is a novel form of medicine

Following the published article,we noticed an error duplication in Figure 5G“control”and“PGY-6”that was introduced during the revised process,with an attempt to replace it with higher-resolution images.Here we provide the original data in the first submitted manuscript(Figure 5G).

Site-specific determination of TTR-related functional peptides by using scanning tunneling microscopy

For the design and optimization of functional peptides, unravelling the structures of individual building blocks as well as the properties of the ensemble is paramount. TI＇R1, derived from human transthyretin, is a fibril-forming peptide implicated in diseases such as familial amyloid polyneuropathy and senile systemic amyloidosis. The functional peptide TTR1-RGD, based on a TFR1 scaffold, was designed to specifically interact with cells. Here, we used scanning tunneling microscopy （STM） to analyze the assembly structures of TTRl-related peptides with both the reverse sequence and the modified forward sequence. The site- specific analyses show the following： i） The TIR1 peptide is involved in assembly, nearly covering the entire length within the ordered [3-sheet structures, ii） For TTR1-RGD peptide assemblies, the TTR1 motif forms the ordered [3-sheet while the RGDS motif adopts a flexible conformation allowing it to promote cell adhesion. The key site is clearly identified as the linker residue Gly13. iii） Close inspection of the forward and reverse peptide assemblies show that in spite of the difference in chemistry, they display similar assembling characteristics, illustrating the robust nature of these peptides, iv） Glycine linker residues are included in the ^-strands, which strongly suggests that the sequence could be optimized by adding more linker residues. These garnered insights into the assembled structures of these peptides help unravel the mechanism driving peptide assemblies and instruct the rational design and optimization of sequence- programmed peptide architectures.

Enthalpy induced phase partition toward hierarchical,nanostructured high-entropy alloys

Heterogeneous nanostructured metals are emerging strategies for achieving both high strength and ductility,which are particularly attractive for high entropy alloys(HEAs)to combine the synergistic enhancements from multielement composition,grain boundaries,and heterogeneity effects.However,the construction of heterogeneous nanostructured HEAs remains elusive and can involve delicate processes that are not practically scalable.Herein we report using composition design(i.e.,enthalpy engineering)to create hierarchical,nanostructured HEAs as demonstrated by adding Ni into FeCrCoAlTi_(0.5)HEA.The strong enthalpic interaction between(Ni,Co)and(Al,Ti)pairs in FeCrCoAlTi_(0.5)Nix(x=0.5–1.5)induced phase partitions into B2(ordered phase,hard)matrix and A2(disordered phase,soft)precipitates,resulting in a hierarchical structure of B2 grains and sub-grains of near-coherent A2 nanodomains(~12.5 nm)divided by A2 interdendritic regions.As a result,the FeCrCoAlTi_(0.5)Ni_(0.5)HEA with this unique hierarchical nanostructure exhibits the best combination of strength and plasticity,i.e.,a 2-fold increase in compressive strength(2.60 GPa)and significant enhancement of plastic strain(15.8%)as compared with the original FeCrCoAlTi_(0.5)HEA.Enthalpy analysis and simulation study reveal the phase partition process during cooling induced by an enthalpy-driven order-disorder transition while the order parameters illustrate the strong ordering in(Ni,Co)(Al,Ti)-rich B2 phase and high entropy mixing in less interactive FeCrCo-rich A2 phase.Our work therefore provides a strategy for hierarchical nanostructured HEA formation by composition design considering enthalpy and entropy interplay.