Monodispersed FeS2 Electrocatalyst Anchored to Nitrogen-Doped Carbon Host for Lithium–Sulfur Batteries

Despite their high theoretical energy density, lithium–sulfur (Li–S) batteries are hindered by practical challenges including sluggish conversion kinetics and shuttle effect of polysulfides. Here, a nitrogen-doped continuous porous carbon (CPC) host anchoring monodispersed sub-10\ua0nm FeS2 nanoclusters (CPC@FeS2) is reported as an efficient catalytic matrix for sulfur cathode. This host shows strong adsorption of polysulfides, promising the inhibition of polysulfide shuttle and the promoted initial stage of catalytic conversion process. Moreover, fast lithium ion (Li-ion) diffusion and accelerated solid–solid conversion kinetics of Li2S2 to Li2S on CPC@FeS2 host guarantee boosted electrochemical kinetics for conversion process of sulfur species in Li–S cell, which gives a high utilization of sulfur under practical conditions of high loading and low electrolyte/sulfur (E/S) ratio. Therefore, the surfur cathode (S/CPC@FeS2) delivers a high specific capacity of 1459 mAh g−1 at 0.1 C, a stable cycling over 900 cycles with ultralow fading rate of 0.043% per cycle, and an enhanced rate capability compared with cathode only using carbon host. Further demonstration of this cathode in Li–S pouch cell shows a practical energy density of 372\ua0Wh kg−1 with a sulfur loading of 7.1\ua0mg cm−2 and an E/S ratio of 4\ua0\ub5L mg−1

BRI1 EMS SUPPRESSOR1 genes regulate abiotic stress and anther development in wheat (Triticum aestivum L.)

BRI1 EMS SUPPRESSOR1 (BES1) family members are crucial downstream regulators that positively mediate brassinosteroid signaling, playing vital roles in the regulation of plant stress responses and anther development in Arabidopsis. Importantly, the expression profiles of wheat (Triticum aestivum L.) BES1 genes have not been analyzed comprehensively and systematically in response to abiotic stress or during anther development. In this study, we identified 23 BES1-like genes in common wheat, which were unevenly distributed on 17 out of 21 wheat chromosomes. Phylogenetic analysis clustered the BES1 genes into four major clades; moreover, TaBES1-3A2, TaBES1-3B2 and TaBES1-3D2 belonged to the same clade as Arabidopsis BES1/BZR1 HOMOLOG3 (BEH3) and BEH4, which participate in anther development. The expression levels of 23 wheat BES1 genes were assessed using real-time quantitative PCR under various abiotic stress conditions (drought, salt, heat, and cold), and we found that most TaBES1-like genes were downregulated under abiotic stress, particularly during drought stress. We therefore used drought-tolerant and drought-sensitive wheat cultivars to explore TaBES1 expression patterns under drought stress. TaBES1-3B2 and TaBES1-3D2 expression was high in drought-tolerant cultivars but substantially repressed in drought-sensitive cultivars, while TaBES1-6D presented an opposite pattern. Among genes preferentially expressed in anthers, TaBES1-3B2 and TaBES1-3D2 expression was substantially downregulated in thermosensitive genic male-sterile wheat lines compared to common wheat cultivar under sterile conditions, while we detected no obvious differences under fertile conditions. This result suggests that TaBES1-3B2 and TaBES1-3D2 might not only play roles in regulating drought tolerance, but also participate in low temperature-induced male sterility

Effect of mutation of Lys65 on the colocalization of α_2A-AR with the ER marker DsRed2-ER.

<p>(A) HEK293 cells were transiently transfected with the GFP-tagged α_2A-AR or its Lys65 mutants together with pDsRed2-ER. The subcellular distribution and co-localization of the receptors with the ER marker DsRed2-ER were revealed by confocal fluorescence microscopy as described under “<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050416#s2" target="_blank">Materials and Methods</a>”. <i>Green</i>, α_2A-AR or its mutants tagged with GFP; <i>red</i>, DsRed2-ER; <i>yellow</i>, co-localization of α_2A-AR or its mutants with the ER marker DsRed2-ER; <i>blue</i>, DNA staining by DAPI (nuclei). The data shown are representative images of at least three independent experiments. (B) Quantification of Pearson’s coefficient between the receptors and the ER marker. The data are presented as the mean ± S.E. of 20 cells from three different experiments. *, <i>p</i><0.05 <i>versus</i> WT α_2A-AR. Scale bar, 10 µm.</p

Effects of the mutation of Leu residues and their neighboring positively charged residues in the ICL1 on the cell-surface and total expression of α_2A-AR and α_2B-AR.

<p>(A) The sequence of the ICL1 of α_2A-AR, α_2B-AR and α_2C-AR. (B) Ligand dose-dependent binding of α_2A-AR in intact HEK293 cells. HEK293 cells cultured on 6-well plates were transfected with α_2A-AR and then split onto 24-well plates. The cells were incubated with increasing concentrations of [³H]-RX821002 (0.3125, 0.625, 1.25, 2.5, 5, 10, and 20 nM) and the ligand bound to the receptor was measured by liquid scintillation spectrometry as described in the “<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050416#s2" target="_blank">Materials and Methods</a>”. The nonspecific binding was determined in the presence of rauwolscine (10 µM). Similar results were obtained in at least three different experiments. (C) Quantification of the cell-surface and total expression of α_2A-AR and its mutants in which Leu64 and Lys65 were mutated to Ala individually or in combination. (D) Quantification of the cell-surface and total expression of α_2B-AR and its mutants in which Leu48 and Arg49 were mutated to Ala. In (C) and (D), HEK293 cells were transfected with α₂-AR and the cell-surface expression of the receptors was measured by intact cell binding assays using [³H]-RX821002 at 20 nM. The mean values of specific [³H]-RX821002 binding were 27255±415 and 16785±452 cpm from cells transfected with wild-type (WT) α_2A-AR and α_2B-AR, respectively. Wild-type α_2A-AR and α_2B-AR and their mutants were tagged with GFP and transiently expressed in HEK293 cells. Total receptor expression was determined by flow cytometry measuring the GFP signal as described in the “<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050416#s2" target="_blank">Materials and Methods</a>”. (E) Quantification of the cell-surface expression of α_2A-AR and its mutants by flow cytometry. HEK293 cells were transfected with HA-tagged α_2A-AR or its individual mutant and the cell-surface expression of the receptors was measured by flow cytometry following staining with anti-HA antibodies in nonpermeabilized cells as described in the “<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050416#s2" target="_blank">Materials and Methods</a>”. The data shown in (C), (D), and (E) are percentages of the mean value obtained from cells transfected with wild-type α₂-AR and are presented as the mean ± S.E. of at least three different experiments. *, <i>p</i><0.05 <i>versus</i> respective WT α₂-AR.</p

Effects of mutating Lys65 to Arg, Glu and Gln on the cell-surface expression and subcellular distribution of α_2A-AR.

<p>(A) Quantification of the cell surface and total expression of α_2A-AR and its Lys mutants. HEK293 cells were transfected with α_2A-AR and its mutants. The cell-surface expression of the receptors was measured by intact cell binding assays using [³H]-RX821002 and total receptor expression by flow cytometry measuring the GFP signal as described in the legends of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050416#pone-0050416-g001" target="_blank">figure 1</a>. (B) Quantification of the cell-surface expression of α_2A-AR and its mutants by flow cytometry following staining with anti-HA antibodies in nonpermeabilized cells as described in the legends of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050416#pone-0050416-g001" target="_blank">figure 1</a>. The data shown in (A) and (B) are percentages of the mean value obtained from cells transfected with wild-type (WT) α_2A-AR and are presented as the mean ± S.E. of four experiments. *, <i>p</i><0.05 <i>versus</i> WT α_2A-AR. (C) Effect of mutation of Lys65 on the subcellular distribution of α_2A-AR. α_2A-AR and its mutants K65R, K65E and K65Q were tagged with GFP at their C-termini and transiently expressed in HEK293 (<i>upper panel</i>) and HeLa cells (<i>lower panel</i>). Their subcellular distribution was revealed by detecting GFP fluorescence by confocal microscopy. The data shown are representative images of at least three independent experiments. <i>Green</i>, GFP-tagged receptors; <i>blue</i>, DNA staining by DAPI (nuclei). Scale bar, 10 µm.</p

Effects of mutating Lys65 to Ala and Arg on α_2A-AR-mediated activation of ERK1/2.

<p>(A) HEK293 cells were transfected with wild-type (WT) α_2A-AR or its mutants K65A and K65R and then stimulated with increasing concentrations of UK14,304 for 5 min. ERK1/2 activation was determined by Western blot analysis using phospho-specific ERK1/2 antibodies. <i>Upper panel</i>, a representative blot of ERK1/2 activation; <i>Lower panel</i>, total ERK1/2 expression. (B) Quantitative data expressed as percentage of ERK1/2 activation obtained in cells transfected with α_2A-AR and stimulated with UK14304 at 1 µM and presented as the mean ± S.E. of three separate experiments. *, <i>p</i><0.05 <i>versus</i> WT α_2A-AR at the same concentration of UK14,304.</p

Effects of mutating Leu64 and Lys65 residues on the subcellular distribution of α_2A-AR.

<p>GFP-tagged wild-type (WT) α_2A-AR and its mutants L64A, K65A and LK-AA were transiently expressed in HEK293 (<i>upper panel</i>) and HeLa cells (<i>lower panel</i>) and their subcellular distribution of the receptors was revealed by detecting GFP fluorescence by confocal microscopy. The data shown are representative images of at least three independent experiments. <i>Green</i>, GFP-tagged receptors; <i>blue</i>, DNA staining by DAPI (nuclei). Scale bar, 10 µm.</p

Flame Retardant and Stable Li_1.5Al_0.5Ge_1.5(PO₄)₃‑Supported Ionic Liquid Gel Polymer Electrolytes for High Safety Rechargeable Solid-State Lithium Metal Batteries

Recently, poor security in conventional liquid electrolytes and high interfacial resistance at the electrode/electrolyte interface are the most challenging barriers for the expanded application of lithium batteries. In this regard, easy processing and flexible composite ionic liquid gel polymer electrolytes (ILGPEs) supported by Li_1.5Al_0.5­Ge_1.5­(PO₄)₃ (LAGP) are fabricated and investigated. The electrolyte is effectively combined with good electrochemical performances and thermal safety. Among these, the effects of different types of fillers such as the inert filler-SiO₂ and the active filler-LAGP on the ionic conductivity were studied in detail. LAGP particles can not only effectively reduce the crystallinity of the polymer matrix but also provide lithium ions and act as the lithium-ion conductor leading to higher ionic conductivity and Li⁺ ion transference number. Especially, the electrolyte shows good compatibility and no dendrite with the Li metal anode, significantly improving cyclic stability of LiFe­PO₄/Li batteries. The results indicate that the ILGPE-10%LAGP is a potential alternative electrolyte for high safety rechargeable solid-state lithium metal batteries