Ternary Imidazolium-Pyrrolidinium-Based Ionic Liquid Electrolytes for Rechargeable Li-O 2 Batteries

The conductivity and anodic stability of ternary mixed ionic liquid (IL) electrolytes consisting of pyrrolidinium [N-butyl-Nmethylpyrrolidinium + (PYR 14 + )] and imidazolium [1-butyl-3-methylimidazolium + (BMIM + )] based bis(trifluoromethylsulfonyl) imide (TFSI − ) with 0.5 M LiTFSI salt were investigated. PYR 14 TFSI ionic liquid has been reported to be stable under an oxidative environment, while BMIMTFSI provides good ionic conductivity. A conductivity study of IL electrolytes revealed a linear correlation of conductivity as a function of IL -Li salt concentration and IL volume fraction. As a result, improved battery cycling in a mixture of 4:1 (80/20 v/v%) BMIM + : PYR 14 + was observed with a specific capacity of 330 mAh.g −1 over 50 cycles at a current density of 0.1 mA.cm −2 . Also, an EIS study revealed decreasing cathode polarization by demonstrating lower impedance values for ternary mixed electrolyte than that of the pure electrolytes upon cycling. The commercial potential of Li-O 2 rechargeable batteries is tremendous due to their extremely high theoretical energy density of 12 kWh.kg −1 (excluding oxygen), which is comparable to that of gasoline. 1 For automotive applications, Li-O 2 battery technology may be viable if it can provide 1.7 kWh.kg −1 of energy to the wheels after losses from the battery chemistry. However, this technology is suffering with several issues related to electrodes and electrolyte such as lithium metal corrosion, electrolyte decomposition, wettability, cathode structure retention, catalyst selection, among others, which result in a large irreversibility and poor cycle life. 1,2 Previous reports on electrolytes 3-5 suggest that conventional carbonate based electrolyte decomposes during the discharge process to produce irreversible byproducts such as alkyl carbonates and lithium carboxylates; and during the charging process, the oxidative decomposition of these byproducts 6 lead to CO 2 , CO, and other gases instead of O 2 . It has been found that this decomposition process is favored by the highly reactive superoxide radical anion (O 2 •− ) formed through single-electron reduction of oxygen (O 2 + e − → O 2 •− ). 9-11 Another polar solvent, dimethyl sulfoxide (DMSO), is not stable against a Li anode as it can absorb moisture from the air. 20 Although PYR 14 TFSI is stable, its high viscosity (100 centipoise) and low conductivity (1.4 × 10 −3 S cm −1 ) 21 limit the diffusion rate of lithium ions in the electrolyte. On the other hand, various imidazolium based molten salts have demonstrated better cyclability compared to pyrrolidinium in lithium batteries 22 because of the higher ionic conductivity and lower viscosity. Hence, a mixed imidazolium and pyrrolidinium based IL electrolyte could provide the stability and conductivity needed for both Liair and high power Li-ion batteries (LIB). For instance, a ternary ionic liquid: 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide, N-cyanoethyl-N,N,N-trimethylammonium bis(trifluoromethanesulfonyl)imide, and LiTFSI, exhibited a discharge capacity close z E-mail: [email protected] to the theoretical value with good compatibility with a LiCoO 2 cathode. 23 For Li-O 2 batteries, Cecchetto et al. investigated a mixture of PYR 14 TFSI: TEGDME-LiCF 3 SO 3 (1:1) and observed a lower overvoltage with higher conductivity for the electrolyte mixture than TEGDME alone. The present study aims to investigate ternary mixtures (IL 1 -IL 2 -Li-salt) of imidazolium and pyrrolidinium based ILs for Li-O 2 applications. BMIMTFSI was chosen as the imidazolium based IL as it has high ionic conductivity (4 mS.cm −1 ) and lower viscosity (32 centipoise), whereas, PYR 14 TFSI as a pyrrolidinium based IL as a stable solvent. Herein, different ternary mixtures of BMIMTFSI + PYR 14 TFSI + 0.5 M LiTFSI were prepared to study the effect of IL composition on ionic conductivity, electrochemical stability, lithium transference number, and Li-O 2 battery performance. It was found that 4:1 (BMIMTFSI:PYR 14 TFSI) mixed electrolyte enhanced both cyclic performance and columbic efficiency compared to BMIMTFSI or PYR 14 TFSI used alone. Experimental Ternary mixtures of electrolyte preparation.-1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl imide) (BMIMTFSI) (Sigma-Aldrich), and N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (PYR 14 TFSI) (TCI America) were used as room-temperature ionic liquids. The chemical structures are shown in Conductivity measurement.-Conductivity of all pure and mixtures of ILs were determined using a digital conductivity meter (VWR International, LLC, model 2052). All tests were measured at room temperature inside the glove box. Electrochemical stability measurement.-The electrochemical stability window of the LiTFSI-IL solutions was determined by linear sweep voltammetry (LSV) using a Gamry Reference 3000 Potentiosta

Multiple Frequencies Sequential Coding for SSVEP-Based Brain-Computer Interface

BACKGROUND: Steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) has become one of the most promising modalities for a practical noninvasive BCI system. Owing to both the limitation of refresh rate of liquid crystal display (LCD) or cathode ray tube (CRT) monitor, and the specific physiological response property that only a very small number of stimuli at certain frequencies could evoke strong SSVEPs, the available frequencies for SSVEP stimuli are limited. Therefore, it may not be enough to code multiple targets with the traditional frequencies coding protocols, which poses a big challenge for the design of a practical SSVEP-based BCI. This study aimed to provide an innovative coding method to tackle this problem. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we present a novel protocol termed multiple frequencies sequential coding (MFSC) for SSVEP-based BCI. In MFSC, multiple frequencies are sequentially used in each cycle to code the targets. To fulfill the sequential coding, each cycle is divided into several coding epochs, and during each epoch, certain frequency is used. Obviously, different frequencies or the same frequency can be presented in the coding epochs, and the different epoch sequence corresponds to the different targets. To show the feasibility of MFSC, we used two frequencies to realize four targets and carried on an offline experiment. The current study shows that: 1) MFSC is feasible and efficient; 2) the performance of SSVEP-based BCI based on MFSC can be comparable to some existed systems. CONCLUSIONS/SIGNIFICANCE: The proposed protocol could potentially implement much more targets with the limited available frequencies compared with the traditional frequencies coding protocol. The efficiency of the new protocol was confirmed by real data experiment. We propose that the SSVEP-based BCI under MFSC might be a promising choice in the future

HTLV-1 bZIP Factor Induces T-Cell Lymphoma and Systemic Inflammation In Vivo

Human T-cell leukemia virus type 1 (HTLV-1) is the causal agent of a neoplastic disease of CD4+ T cells, adult T-cell leukemia (ATL), and inflammatory diseases including HTLV-1 associated myelopathy/tropical spastic paraparesis, dermatitis, and inflammatory lung diseases. ATL cells, which constitutively express CD25, resemble CD25+CD4+ regulatory T cells (Treg). Approximately 60% of ATL cases indeed harbor leukemic cells that express FoxP3, a key transcription factor for Treg cells. HTLV-1 encodes an antisense transcript, HTLV-1 bZIP factor (HBZ), which is expressed in all ATL cases. In this study, we show that transgenic expression of HBZ in CD4+ T cells induced T-cell lymphomas and systemic inflammation in mice, resembling diseases observed in HTLV-1 infected individuals. In HBZ-transgenic mice, CD4+Foxp3+ Treg cells and effector/memory CD4+ T cells increased in vivo. As a mechanism of increased Treg cells, HBZ expression directly induced Foxp3 gene transcription in T cells. The increased CD4+Foxp3+ Treg cells in HBZ transgenic mice were functionally impaired while their proliferation was enhanced. HBZ could physically interact with Foxp3 and NFAT, thereby impairing the suppressive function of Treg cells. Thus, the expression of HBZ in CD4+ T cells is a key mechanism of HTLV-1-induced neoplastic and inflammatory diseases

Functional Analysis of a Dominant Negative Mutation of Interferon Regulatory Factor 5

BACKGROUND: Interferon regulatory factor (IRF) family members have been implicated as critical transcription factors that function in immune response, hematopoietic differentiation and cell growth regulation. Activation of IRF-5 results in the production of pro-inflammatory cytokines such as TNFalpha, IL6 and IL12p40, as well as type I interferons. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we identify a G202C (position relative to translation start codon) missense-mutation transcript of IRF-5 in transformed B and T cell lines, which were either infected or non-infected by viruses, and peripheral blood from ATL or CLL patients. The mutated transcript encodes a novel protein in which the sixty-eighth amino acid, Alanine, is substituted by Proline (IRF-5P68) in the DNA binding domain of IRF-5. IRF-5P68 phenotype results in a complete loss of its DNA-binding activity and functions as a dominant negative molecule through interacting with wild type IRF-5. Co-expression of IRF-5P68 inhibits MyD88-mediated IRF-5 transactivation. Moreover, Toll-like receptor (TLR)-dependent IL6 and IL12P40 production induced by lipopolysaccharide (LPS), R837 or CpG ODN 1826 was reduced in IRF-5 (P68) expressing cells as compared to the control cells. CONCLUSION: IRF-5P68 acts as a dominant negative regulator that interferes with IRF-5-mediated production of pro-inflammatory cytokines. The functional characterization of the novel IRF-5 mutant in transformed B and T cell lines and in ATL and CLL patients may lead to a better understanding of the role of these transcriptional regulators in hematopoietic malignancies

Identifying Compound-Target Associations by Combining Bioactivity Profile Similarity Search and Public Databases Mining

Molecular target identification is of central importance to drug discovery. Here, we developed a computational approach, named bioactivity profile similarity search (BASS), for associating targets to small molecules by using the known target annotations of related compounds from public databases. To evaluate BASS, a bioactivity profile database was constructed using 4296 compounds that were commonly tested in the US National Cancer Institute 60 human tumor cell line anticancer drug screen (NCI-60). Each compound was used as a query to search against the entire bioactivity profile database, and reference compounds with similar bioactivity profiles above a threshold of 0.75 were considered as neighbor compounds of the query. Potential targets were subsequently linked to the identified neighbor compounds by using the known targets o

Path and Ridge Regression Analysis of Seed Yield and Seed Yield Components of Russian Wildrye (Psathyrostachys juncea Nevski) under Field Conditions

The correlations among seed yield components, and their direct and indirect effects on the seed yield (Z) of Russina wildrye (Psathyrostachys juncea Nevski) were investigated. The seed yield components: fertile tillers m-2 (Y1), spikelets per fertile tillers (Y2), florets per spikelet- (Y3), seed numbers per spikelet (Y4) and seed weight (Y5) were counted and the Z were determined in field experiments from 2003 to 2006 via big sample size. Y1 was the most important seed yield component describing the Z and Y2 was the least. The total direct effects of the Y1, Y3 and Y5 to the Z were positive while Y4 and Y2 were weakly negative. The total effects (directs plus indirects) of the components were positively contributed to the Z by path analyses. The seed yield components Y1, Y2, Y4 and Y5 were significantly (P<0.001) correlated with the Z for 4 years totally, while in the individual years, Y2 were not significant correlated with Y3, Y4 and Y5 by Peason correlation analyses in the five components in the plant seed production. Therefore, selection for high seed yield through direct selection for large Y1, Y2 and Y3 would be effective for breeding programs in grasses. Furthermore, it is the most important that, via ridge regression, a steady algorithm model between Z and the five yield components was founded, which can be closely estimated the seed yield via the components

Modeling a New Water Channel That Allows SET9 to Dimethylate p53

SET9, a protein lysine methyltransferase, has been thought to be capable of transferring only one methyl group to target lysine residues. However, some reports have pointed out that SET9 can dimethylate Lys372 of p53 (p53-K372) and Lys4 of histone H3 (H3-K4). In order to understand how p53 can be dimethylated by SET9, we measured the radius of the channel that surrounds p53-K372, first on the basis of the crystal structure of SET9, and we show that the channel is not suitable for water movement. Second, molecular dynamic (MD) simulations were carried out for 204 ns on the crystal structure of SET9. The results show that water leaves the active site of SET9 through a new channel, which is made of G292, A295, Y305 and Y335. In addition, the results of molecular docking and MD simulations indicate that the new water channel continues to remain open when S-adenosyl-L-methionine (AdoMet) or S-adenosyl-L-homocysteine (AdoHcy) is bound to SET9. The changes in the radii of these two channels were measured in the equilibrium phase at the constant temperature of 300 K. The results indicate that the first channel still does not allow water to get into or out of the active site, but the new channel is large enough to allow this water to circulate. Our results indicate that water can be removed from the active site, an essential process for allowing the dimethylation reaction to occur