Anatomical physiological and biochemical processes involved in grapevine rootstock drought tolerance

In order to explore the drought resistance mechanism of grape rootstocks, two grape rootstock species, '1103P' (a drought-tolerant rootstock) and '101-14M' (drought-sensitive), were treated with moderate water deficit (field capacity of 45-50 %). Throughout the experimental period, the leaves of '1103P' showed a higher stomatal conductance (gs), relative water content and photosynthetic rate (Pn) than '101-14M', indicating '1103P' was more resistant to tolerant than '101-14M'. We propose that '1103P' could prevent water loss from leaves under drought conditions based on the discoveries that '1103P' had higher leaf phytohormone abscisic acid (ABA) content and leaf cuticular wax content, and smaller stomata aperture than those of '101-14M'. Additionally, the activities of H2O2-scavenging enzymes in leaves of '1103P' were higher than those of '101-14M' under drought conditions, indicating the lipid peroxidation induced by H2O2 of '1103P' was less serious than that of '101-14M'. Therefore, better water-saving and higher reactive oxygen species (ROS) scavenging abilities contributed together to stronger drought resistance of '1103P' than '101-14M'

Immobilization of Horseradish Peroxidase on Multi-Armed Magnetic Graphene Oxide Composite: Improvement of Loading Amount and Catalytic Activity

U ovom je radu po prvi puta sintetiziran novi tip zvjezdastog kompozita polietilen glikola (PEG) s grafen oksidom (GO@Fe3O4@6arm-PEG-NH2), te je upotrijebljen kao podloga za imobilizaciju peroksidaze iz hrena. Udjel peroksidaze iz hrena na kompozitu bio je relativno velik (186,34 mg/g) zbog velikog broja amino skupina iz 6arm-PEG-NH2 prisutnih na površini nosača. Brzina razgradnje fenolnih spojeva bila je bitno veća (95,4 %) zbog sinergijskog učinka slobodne peroksidaze (45,4 %) i podloge (13,6 %). Nakon imobilizacije povećala se toplinska stabilnost, te su se produljili vrijeme trajanja i iskoristivost enzima u usporedbi sa slobodnim enzimom. Imobilizirana peroksidaza je zadržala više od 68,1 % aktivnosti i nakon što je upotrijebljena osam puta. Rezultati pokazuju da se zvjezdasti magnetizirani kompozit može uspješno primijeniti za imobilizaciju enzima.In this study, a novel type of multi-armed polymer (poyltehylene glycol, PEG) magnetic graphene oxide (GO) composite (GO@Fe3O4@6arm-PEG-NH2) has been synthesized as a support for immobilization of horseradish peroxidase (HRP) for the first time. The loading amount of HRP was relatively high (186.34 mg/g) due to the surface of carrier material containing a large amount of amino groups from 6arm-PEG-NH2, but degradation rate of phenols was also much higher (95.4 %), which is attributed to the synergistic effect between the free HRP (45.4 %) and the support material of GO@Fe3O4@6arm-PEG-NH2 (13.6 %). Compared with the free enzyme, thermal, storage and operational stability of the immobilized HRP improved. The immobilized HRP still retained over 68.1 % activity after being reused 8 times. These results suggest that the multi-armed magnetic composite has good application prospect for enzyme immobilization

A hydrated deep eutectic electrolyte with finely-tuned solvation chemistry for high-performance zinc-ion batteries

Despite their cost-effectiveness and intrinsic safety, aqueous zinc-ion batteries have faced challenges with poor reversibility originating from various active water-induced side reactions. After systematically scrutinizing the effects of water on the evolution of solvation structures, electrolyte properties, and electrochemical performances through experimental and theoretical approaches, a hydrated deep eutectic electrolyte with a water-deficient solvation structure ([Zn(H2O)2(eg)2(otf)2]) and reduced free water content in the bulk solution is proposed in this work. This electrolyte can dramatically suppress water-induced side reactions and provide high Zn2+ mass transfer kinetics, resulting in highly reversible Zn anodes (∼99.6% Coulombic efficiency over 1000 cycles and stable cycling over 4500 h) and high capacity Zn//NVO full cells (436 mA h g−1). This work will aid the understanding of electrolyte solvation structure–electrolyte property–electrochemical performance relationships of aqueous electrolytes in aqueous zinc-ion batteries

Metal–organic frameworks and their derivatives for optimizing lithium metal anodes

Lithium metal anodes (LMAs) have been considered the ultimate anode materials for next-generation batteries. However, the uncontrollable lithium dendrite growth and huge volume expansion that can occur during charge and discharge seriously hinder the practical application of LMAs. Metal–organic framework (MOF) materials, which possess the merits of huge specific surface area, excellent porosity, and flexible composition/structure tunability, have demonstrated great potential for resolving both of these issues. This article first explores the mechanism of lithium dendrite formation as described by four influential models. Subsequently, based on an in-depth understanding of these models, we propose potential strategies for utilizing MOFs and their derivatives to suppress lithium dendrite growth. We then provide a comprehensive review of research progress with respect to various applications of MOFs and their derivatives to suppress lithium dendrites and inhibit volume expansion. The paper closes with a discussion of perspectives on future modifications of MOFs and their derivatives to achieve stable, dendrite-free lithium metal batteries

Trace Amounts of Triple-Functional Additives Enable Reversible Aqueous Zinc-Ion Batteries from a Comprehensive Perspective

Although their cost-effectiveness and intrinsic safety, aqueous zinc-ion batteries suffer from notorious side reactions including hydrogen evolution reaction, Zn corrosion and passivation, and Zn dendrite formation on the anode. Despite numerous strategies to alleviate these side reactions have been demonstrated, they can only provide limited performance improvement from a single aspect. Herein, a triple-functional additive with trace amounts, ammonium hydroxide, was demonstrated to comprehensively protect zinc anodes. The results show that the shift of electrolyte pH from 4.1 to 5.2 lowers the HER potential and encourages the in situ formation of a uniform ZHS-based solid electrolyte interphase on Zn anodes. Moreover, cationic NH4+ can preferentially adsorb on the Zn anode surface to shield the "tip effect" and homogenize the electric field. Benefitting from this comprehensive protection, dendrite-free Zn deposition and highly reversible Zn plating/stripping behaviors were realized. Besides, improved electrochemical performances can also be achieved in Zn//MnO2 full cells by taking the advantages of this triple-functional additive. This work provides a new strategy for stabilizing Zn anodes from a comprehensive perspective