Efficient Spermidine Production Using a Multi-Enzyme Cascade System Utilizing Methionine Adenosyltransferase from Lactobacillus fermentum with Reduced Product Inhibition and Acidic pH Preference.

Methionine adenosyltransferases (MATs; EC 2.5.1.

Constructing High-Yielding for (-)-α-Bisabolol Production Based on the Exogenous Haloarchaeal MVA Pathway and Endogenous Molecular Chaperones.

(-)-α-Bisabolol exhibits analgesic, anti-inflammatory, and skin-soothing properties and is widely applied in the cosmetic and pharmaceutical industries. The use of plant essential oil distillation or chemical synthesis to produce (-)-α-bisabolol is both inefficient and unsustainable. Currently, the microbial production of (-)-α-bisabolol mainly relies on and as chassis strains; however, high concentrations of (-)-α-bisabolol have certain toxicity to the strain.

Saccharomyces cerevisiae strains L7 contribute to flavor and deacidification in Suanyu, a Chinese traditional fermented fish.

Saccharomyces cerevisiae L7 was found to be an excellent starter and biological deacidification strain for Suanyu, however, the underlying mechanisms remain poorly understood. This study aimed to investigate the acid inhibition mechanism of S. cerevisiae L7.

Rationally Designed Mo/Ru-Based Multi-Site Heterogeneous Electrocatalyst for Accelerated Alkaline Hydrogen Evolution Reaction.

The rational design of multi-site electrocatalysts with three different functions for facile HO dissociation, H-H coupling, and rapid H release is desirable but difficult to achieve. This strategy can accelerate the sluggish kinetics of the hydrogen evolution reaction (HER) under alkaline conditions. To resolve this issue, a Mo/Ru-based catalyst with three different active sites (Ru/MoC/MoO) is rationally designed and its performance in alkaline HER is evaluated.

Deciphering the roles of bacterial and fungal communities in the formation and quality of agarwood.

Aquilaria sinensis is a significant resin-producing plant worldwide that is crucial for agarwood production. Agarwood has different qualities depending on the method with which it is formed, and the microbial community structures that are present during these methods are also diverse. Furthermore, the microbial communities of plants play crucial roles in determining their health and productivity.

Targeting limbal epithelial stem cells: master conductors of corneal epithelial regeneration from the bench to multilevel theranostics.

The cornea is the outermost layer of the eye and plays an essential role in our visual system. Limbal epithelial stem cells (LESCs), which are localized to a highly regulated limbal niche, are the master conductors of corneal epithelial regeneration. Damage to LESCs and their niche may result in limbal stem cell deficiency (LSCD), a disease confused ophthalmologists so many years and can lead to corneal conjunctivalization, neovascularization, and even blindness.

Characterization of Fusarium species causing head blight of highland barley (qingke) in Tibet, China.

Most of the research on the characterization of Fusarium species focused on wheat, barley, rice, and maize in China. However, there has been limited research in highland barley (qingke). Recently, Fusarium head blight (FHB) of qingke was recently observed in Tibet, China, especially around the Brahmaputra River.

SDN-Based Congestion Control and Bandwidth Allocation Scheme in 5G Networks.

5G cellular networks are already more than six times faster than 4G networks, and their packet loss rate, especially in the Internet of Vehicles (IoV), can reach 0.5% in many cases, such as when there is high-speed movement or obstacles nearby. In such high bandwidth and high packet loss network environments, traditional congestion control algorithms, such as CUBIC and bottleneck bandwidth and round-trip propagation time (BBR), have been unable to balance flow fairness and high performance, and their flow rate often takes a long time to converge.

Unveiling the Structural Origins of Dynamic Diversity in Pd-Based Metallic Glasses.

The β-relaxation is one of the major dynamic behaviors in metallic glasses (MGs) and exhibits diverse features. Despite decades of efforts, the understanding of its structural origin and contribution to the overall dynamics of MG systems is still unclear. Here two palladium-based Pd─Cu─P and Pd─Ni─P MGs are reported with distinct different β-relaxation behaviors and reveal the structural origins for the difference using the advanced X-ray photon correlation spectroscopy and absorption fine structure techniques together with the first-principles calculations.

Anomalous temperature dependence of elastic limit in metallic glasses.

Understanding the atomistic mechanisms of inelastic deformation in metallic glasses (MGs) remains challenging due to their amorphous structure, where local carriers of plasticity cannot be easily defined. Using molecular dynamics (MD) simulations, we analyzed the onset of inelastic deformation in CuZr MGs, specifically the temperature dependence of the elastic limit, in terms of localized shear transformation (ST) events. We find that although the ST events initiate at lower strain with increasing temperature, the elastic limit increases with temperature in certain temperature ranges.

Alkali-Ion Batteries by Carbon Encapsulation of Liquid Metal Anode.

Gallium-based metallic liquids, exhibiting high theoretical capacity, are considered a promising anode material for room-temperature liquid metal alkali-ion batteries. However, electrochemical performances, especially the cyclic stability, of the liquid metal anode for alkali-ion batteries are strongly limited because of the volume expansion and unstable solid electrolyte interphase film of liquid metal. Here, the bottleneck problem is resolved by designing carbon encapsulation on gallium-indium liquid metal nanoparticles (EGaIn@C LMNPs).

Nanotechnology-based ocular drug delivery systems: recent advances and future prospects.

Ocular drug delivery has constantly challenged ophthalmologists and drug delivery scientists due to various anatomical and physiological barriers. Static and dynamic ocular barriers prevent the entry of exogenous substances and impede therapeutic agents' active absorption. This review elaborates on the anatomy of the eye and the associated constraints.

Acetolysis of waste polyethylene terephthalate for upcycling and life-cycle assessment study.

To reduce environmental pollution and reliance on fossil resources, polyethylene terephthalate as the most consumed synthetic polyester needs to be recycled effectively. However, the existing recycling methods cannot process colored or blended polyethylene terephthalate materials for upcycling. Here we report a new efficient method for acetolysis of waste polyethylene terephthalate into terephthalic acid and ethylene glycol diacetate in acetic acid.

NiH-catalysed proximal-selective hydroalkylation of unactivated alkenes and the ligand effects on regioselectivity.

Alkene hydrocarbonation reactions have been developed to supplement traditional electrophile-nucleophile cross-coupling reactions. The branch-selective hydroalkylation method applied to a broad range of unactivated alkenes remains challenging. Herein, we report a NiH-catalysed proximal-selective hydroalkylation of unactivated alkenes to access β- or γ-branched alkyl carboxylic acids and β-, γ- or δ-branched alkyl amines.

Insight into levofloxacin loaded biocompatible electrospun scaffolds for their potential as conjunctival substitutes.

The rehabilitation of visual acuity with severe conjunctival fibrosis depends on ocular reconstruction with suitable conjunctival substitutes. In this study, we have developed poly(lactic acid) (PLA) electrospun nanofibrous membranes (EFMs) surface coated by cellulose nanofibrils (CNF) and/or silk peptide (SP). The CNF coating improved the hydrophilicity and the SP coating proliferated conjunctival epithelial cells (CjECs).

Nickel-catalyzed three-component olefin reductive dicarbofunctionalization to access alkylborates.

We report a three-component olefin reductive dicarbofunctionalization for constructing alkylborates, specifically, nickel-catalyzed reductive dialkylation and alkylarylation of vinyl boronates with a variety of alkyl bromides and aryl iodides. This reaction exhibits good coupling efficiency and excellent functional group compatibility, providing convenient access to the late-stage modification of complex natural products and drug molecules. Combined with alkylborate transformations, this reaction could also find applications in the modular and convergent synthesis of complex compounds.

Three-component reaction of -difluorinated cyclopropanes with alkenes and Bpin for the synthesis of monofluoroalkenes.

Borylative difunctionalization of alkenes has emerged as a powerful approach for synthesizing highly functionalized molecules. Herein, dual Cu/Pd-catalysed borylfluoroallylation of alkenes was smoothly achieved by using gem-difluorinated cyclopropanes and B2pin2, providing the corresponding monofluoroalkene scaffolds in moderate to high yields with excellent stereoselectivity. Moreover, an array of synthetic building blocks can be obtained by downstream transformations.

Catalytic asymmetric reductive hydroalkylation of enamides and enecarbamates to chiral aliphatic amines.

To increase the reliability and success rate of drug discovery, efforts have been made to increase the C(sp) fraction and avoid flat molecules. sp-Rich enantiopure amines are most frequently encountered as chiral auxiliaries, synthetic intermediates for pharmaceutical agents and bioactive natural products. Streamlined construction of chiral aliphatic amines has long been regarded as a paramount challenge.

Poisonous delicacy: Market-oriented surveys of the consumption of Rhododendron flowers in Yunnan, China.

Ethnopharmacological Relevance: Plants from the family Ericaceae, and in particular those in the genus Rhododendron are frequently reported to contain grayanotoxins. Plant products such as honey and herbal medicines made from these plants occasionally contain grayanotoxins, and in turn may lead to intoxication. The balance between the benefits and risk of poisoning from Rhododendrons is of concerns.

Documenting the heritage along the Silk Road: An ethnobotanical study of medicinal teas used in Southern Xinjiang, China.

Ethnopharmacological Relevance: People in Southern Xinjiang, China have been consuming medicinal teas for healthcare since before the ancient Silk Road markets began. Several pharmaceutical studies have illustrated the potential healthcare benefits of medicinal teas used in Southern Xinjiang, China. However, little information is available from the literature about the diversity of the species used and related traditional knowledge of these medicinal teas.

Nickel-catalyzed carboxylation of aryl iodides with lithium formate through catalytic CO recycling.

A protocol for the Ni-catalyzed carboxylation of aryl iodides with formate has been developed with good functional group compatibility for the synthesis of a variety of aromatic carboxylic acids under mild conditions. The reaction tolerates other functionalities for cross-coupling, such as aryl bromide, aryl chloride, aryl tosylate, and aryl pinacol boronate. The reaction proceeds through a carbonylation process with in situ generated carbon monoxide in the presence of a catalytic amount of acetic anhydride and lithium formate, avoiding the use of gaseous CO.

Photocatalytic decarboxylative alkenylation of α-amino and α-hydroxy acid-derived redox active esters by NaI/PPh catalysis.

Herein, we report the photocatalytic decarboxylative alkenylation reactions of N-(acyloxy)phthalimide derived from α-amino and α-hydroxy acids with 1,1-diarylethene, and with cinnamic acid derivatives through double decarboxylation, using sodium iodide and triphenylphosphine as redox catalysts. The reaction proceeds under mild irradiation conditions with visible blue light (440 nm or 456 nm) in an acetone solvent without recourse to transition-metal or organic dye based photoredox catalysts. The reaction proceeds via photoactivation of a transiently self-assembled chromophore from N-(acyloxy)phthalimide and NaI/PPh3.

The dual-catalyzed boryldifluoroallylation of alkynes: an efficient method for the synthesis of skipped gem-difluorodienes.

The Cu/Pd-catalyzed boryldifluoroallylation of alkynes was achieved, providing the corresponding skipped gem-difluorodiene scaffolds with high regio- and stereoselectivity in moderate to excellent yields. This new approach has good functional group compatibility for both alkynes and 3,3-difluoro-substituted allylic esters. Moreover, an array of synthetic building blocks, skipped dienes, trienes, and drug mimics can be obtained via further transformations.

Visible light-induced palladium-catalyzed ring opening β-H elimination and addition of cyclobutanone oxime esters.

A palladium catalyst under visible light irradiation activates cyclobutanone oxime ester through single electron transfer to induce radical ring opening to generate hybrid cyanoalkyl Pd(i) radical species. Hybrid cyanoalkyl Pd(i) radical species can undergo either β-H elimination to deliver (E)-4-arylbut-3-enenitrile or undergo radical addition with silyl enol ether and enamide to generate δ-cyano ketones. A dual ligand system composed of two phosphine ligands is essential for the high reactivity.

A weakly basic Co/CeO catalytic system for one-pot conversion of cellulose to diols: Kungfu on eggs.

A controlled, weakly basic Co/CeO catalyst was designed for one-pot conversion of cellulose to ethylene glycol (EG) and 1,2-propylene glycol (1,2-PG) to achieve near-equivalent yield. The efficiency is mainly attributed to Co-O-Ce base-acid pairs that hindered humin formation by ensuring a precise balance across the various steps of the reaction.