Global genome expression analysis of rice in response to drought and high-salinity stresses in shoot, flag leaf, and panicle

To elucidate genome-level responses to drought and high-salinity stress in rice, a 70mer oligomer microarray covering 36,926 unique genes or gene models was used to profile genome expression changes in rice shoot, flag leaf and panicle under drought or high-salinity conditions. While patterns of gene expression in response to drought or high-salinity stress within a particular organ type showed significant overlap, comparison of expression profiles among different organs showed largely organ-specific patterns of regulation. Moreover, both stresses appear to alter the expression patterns of a significant number of genes involved in transcription and cell signaling in a largely organ-specific manner. The promoter regions of genes induced by both stresses or induced by one stress in more than one organ types possess relative enrichment of two cis-elements (ABRE core and DRE core) known to be associated with water stress. An initial computational analysis indicated that novel promoter motifs are present in the promoters of genes involved in rehydration after drought. This analysis suggested that rice might possess a mechanism that actively detects rehydration and facilitates rapid recovery. Overall, our data supports a notion that organ-specific gene regulation in response to the two abiotic stresses may primarily be mediated by organ-specific transcription responses. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11103-006-9111-1) contains supplementary material, which is available to authorized users

Fluorine-donating electrolytes enable highly reversible 5-V-class Li metal batteries

Lithium metal has gravimetric capacity ∼10× that of graphite which incentivizes rechargeable Li metal batteries (RLMB) development. A key factor that limits practical use of RLMB is morphological instability of Li metal anode upon electrodeposition, reflected by the uncontrolled area growth of solid-electrolyte interphase that traps cyclable Li, quantified by the Coulombic inefficiency (CI). Here we show that CI decreases approximately exponentially with increasing donatable fluorine concentration of the electrolyte. By using up to 7 m of Li bis(fluorosulfonyl)imide in fluoroethylene carbonate, where both the solvent and the salt donate F, we can significantly suppress anode porosity and improve the Coulombic efficiency to 99.64%. The electrolyte demonstrates excellent compatibility with 5-V LiNi0.5Mn1.5O4cathode and Al current collector beyond 5 V. As a result, an RLMB full cell with only 1.4× excess lithium as the anode was demonstrated to cycle above 130 times, at industrially significant loading of 1.83 mAh/cm2and 0.36 C. This is attributed to the formation of a protective LiF nanolayer, which has a wide bandgap, high surface energy, and small Burgers vector, making it ductile at room temperature and less likely to rupture in electrodeposition.National Science Foundation (U.S.) (Grant ECCS-1610806

An injectable and self-healing hydrogel with controlled release of curcumin to repair spinal cord injury

The harsh local micro-environment following spinal cord injury (SCI) remains a great challenge for neural regeneration. Local reconstitution of a favorable micro-environment by biocompatible scaffolds with desirable functions has thus been an area of concern. Herein, a hybrid hydrogel was developed using Fmoc-grafted chitosan (FC) and Fmoc peptide (FI). Dynamic reversible π-π stacking interactions of the fluorenyl rings enabled the FC/FI hybrid hydrogel to exhibit excellent injectable and self-healing properties, as characterized by visual appearances and rheological tests. Furthermore, the FC/FI hybrid hydrogel showed a slow and persistent release of curcumin (Cur), which was named as FC/FI-Cur hydrogel. In vitro studies confirmed that with the support of FC/FI-Cur hydrogel, neurite outgrowth was promoted, and Schwann cell (SC) migration away from dorsal root ganglia (DRG) spheres with enhanced myelination was substantiated. The FC/FI-Cur hydrogel well reassembled extracellular matrix at the lesion site of rat spinal cord and exerted outstanding effects in modulating local inflammatory reaction by regulating the phenotypes of infiltrated inflammatory cells. In addition, endogenous SCs were recruited in the FC/FI-Cur graft and participated in the remyelination process of the regenerated nerves. These outcomes favored functional recovery, as evidenced by improved hind limbs movement and enhanced electrophysiological properties. Thus, our study not only advanced the development of multifunctional hydrogels but also provided insights into comprehensive approaches for SCI repair

Electrospun FeS₂@Carbon Fiber Electrode as a High Energy Density Cathode for Rechargeable Lithium Batteries

In this study, an FeS₂@carbon fiber electrode is developed with FeS₂ nanoparticles either embedded in or attached to carbon fibers by using an electrospinning method. By applying this binder-free, metal-current-collector-free FeS₂@carbon fiber electrode, both the redox reaction and capacity decay mechanisms for the Li–FeS₂ system are revealed by changing the electrolyte (conventional carbonate electrolyte and a “solvent-in-salt”-type Li–S battery electrolyte) and working voltage ranges (1.0–3.0 V and 1.5–3.0 V <i>vs</i> Li/Li⁺). The FeS₂@carbon fiber electrode shows stable cycling performance in both the conventional carbonate electrolyte and the solvent-in-salt-type Li–S battery electrolyte in the voltage range of 1.5–3.0 V. Electrochemical tests in the solvent-in-salt-type Li–S battery electrolyte indicate that the Li–FeS₂ system becomes a hybrid of the Li–S cell and Li–iron sulfide cell after the initial cycle. Based on the understanding on the capacity decay mechanisms, the cycling stability of the Li–FeS₂ system in the voltage range of 1.0–3.0 V is then significantly enhanced by coating the FeS₂@carbon fiber electrode with a thin layer of Al₂O₃. The Al₂O₃-coated electrode demonstrates excellent cycling performance with high discharge energy densities at both the material level (∼1300 Wh/kg-FeS₂) and the electrode level (∼1000 Wh/kg-FeS₂ electrode)

Novel approach for a high-energy-density Li-air battery: tri-dimensional growth of Li2O2 crystals tailored by electrolyte Li+ ion concentrations

A novel strategy to improve the utilizing ratio of electrode volume via adjusting the electrolyte Li+ ion concentration is proposed. The variance of storage amount, namely discharge capacity, is up to similar to 600% greater within the investigated region of 10(-3) M to 5 M. This approach provides a novel thought to further improve the energy density of practical devices