Search

Suppressing lithium (Li) dendritegrowth is one of the most critical challenges for the developmentof Li metal batteries. Here, we report for the first time the growthof dendrite-free lithium films with a self-aligned and highly compactednanorod structure when the film was deposited in the electrolyte consistingof 1.0 M LiPF6in propylene carbonate with 0.05 M CsPF6as an additive. Evolution of both the surface and the cross-sectionalmorphologies of the Li films during repeated Li deposition/strippingprocesses were systematically investigated. It is found that the formationof the compact Li nanorod structure is preceded by a solid electrolyteinterphase (SEI) layer formed on the surface of the substrate. Electrochemicalanalysis indicates that an initial reduction process occurred at ∼2.05V vs Li/Li+before Li deposition is responsible for theformation of the initial SEI, while the X-ray photoelectron spectroscopyindicates that the presence of CsPF6additive can largelyenhance the formation of LiF in this initial SEI. Hence, the smoothLi deposition in Cs+-containing electrolyte is the resultof a synergistic effect of Cs+additive and preformed SEIlayer. A fundamental understanding on the composition, internal structure,and evolution of Li metal films may lead to new approaches to stabilizethe long-term cycling stability of Li metal and other metal anodesfor energy storage applications. [ABSTRACT FROM AUTHOR]

Post-translational modification of histones plays essential roles in the transcriptional regulation of genes in eukaryotes. Methylation on basic residues of histones is regulated by histone methyltransferases and histone demethylases, and misregulation of these enzymes has been linked to a range of diseases such as cancer. Histone lysine demethylase 2 (KDM2) family proteins have been shown to either promote or suppress tumorigenesis in different human malignancies. However, the roles and regulation of KDM2 in development are poorly understood, and the exact roles of KDM2 in regulating demethylation remain controversial. Since KDM2 proteins are highly conserved in multicellular animals, we analyzed the KDM2 ortholog in Drosophila . We have observed that dKDM2 is a nuclear protein and its level fluctuates during fly development. We generated three deficiency lines that disrupt the dKdm2 locus, and together with 10 transposon insertion lines within the dKdm2 locus, we characterized the developmental defects of these alleles. The alleles of dKdm2 define three phenotypic classes, and the intragenic complementation observed among these alleles and our subsequent analyses suggest that dKDM2 is not required for viability. In addition, loss of dKDM2 appears to have rather weak effects on histone H3 lysine 36 and 4 methylation (H3K36me and H3K4me) in the third instar wandering larvae, and we observed no effect on methylation of H3K9me2, H3K27me2 and H3K27me3 in dKdm2 mutants. Taken together, these genetic, molecular and biochemical analyses suggest that dKDM2 is not required for viability of flies, indicating that dKdm2 is likely redundant with other histone lysine demethylases in regulating normal development in Drosophila . [ABSTRACT FROM AUTHOR]

Femtosecond absorption spectroscopy of Photosystem I (PS I) complexes from the cyanobacterium Synechocystis sp. PCC 6803 was carried out on three pairs of complementary amino acid substitutions located near the second pair of chlorophyll molecules Chl2A and Chl2B (also termed A-1A and A-1B). The absorption dynamics at delays of 0.1–500 ps were analyzed by decomposition into discrete decay-associated spectra and continuously distributed exponential components. The multi-exponential deconvolution of the absorption changes revealed that the electron transfer reactions in the PsaA-N600M, PsaA-N600H, and PsaA-N600L variants near the B-branch of cofactors are similar to those of the wild type, while the PsaB-N582M, PsaB-N582H, and PsaB-N582L variants near the A-branch of cofactors cause significant alterations of the photochemical processes, making them heterogeneous and poorly described by a discrete exponential kinetic model. A redistribution of the unpaired electron between the second and the third monomers Chl2A/Chl2B and Chl3A/Chl3B was identified in the time range of 9–20 ps, and the subsequent reduction of A1 was identified in the time range of 24–70 ps. In the PsaA-N600L and PsaB-N582H/L variants, the reduction of A1 occurred with a decreased quantum yield of charge separation. The decreased quantum yield correlates with a slowing of the phylloquinone A0 → A1 reduction, but not with the initial transient spectra measured at the shortest time delay. The results support a branch competition model, where the electron is sheared between Chl2A–Chl3A and Chl2B–Chl3B cofactors before its transfer to phylloquinone in either A1A or A1B sites. [ABSTRACT FROM AUTHOR]

Abstract: In this article, two-dimensional, Co3O4 hexagonal nanodiscs are prepared using a hydrothermal method without surfactants. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) have been employed to characterize the structural properties. As revealed by the SEM and TEM experiments, the thickness of our as-fabricated Co3O4 hexagonal nanodiscs is about 20 nm, and the pore diameters range from several nanometers to 30 nm. As an anode for lithium-ion batteries, porous Co3O4 nanodiscs exhibit an average discharge voltage of ∼1 V (vs. Li/Li+) and a high specific charge capacity of 1161 mAh g−1 after 100 cycles. They also demonstrate excellent rate performance and high Columbic efficiency at various rates. These results indicate that porous Co3O4 nanodiscs are good candidates as anode materials for lithium-ion batteries. [Copyright &y& Elsevier]

We present the results of molecular dynamics simulations of net positively charged fullerene nanoparticles in salt-free and salt-added solution. The aggregation of fullerene (C60)-like nanoparticle and counterion are studied in detail as a function of temperatures and a finite salt concentration. Our simulations show that the strong conformation changes as temperature changes. The net positively-charged nanoparticles do not repel each other but are condensed under proper temperatures. If salts are added, the aggregated nanoparticles will be disaggregated due to the Debye screening effect. [ABSTRACT FROM AUTHOR]

This study aims to observe the effects of doxycycline (DOX) on gap junction remodeling after MI and the susceptibility of rats to cardiac arrhythmia. The proximal left anterior descending coronary artery of rats was ligated to establish a myocardial infarction animal model. DOX, methylprednisolone (MP), or vehicle was intraperitoneally injected into the animals for two weeks. Then, the heart size and heart function of all animals were determined through echocardiography. The experimental animals were sacrificed after the electrophysiologic study. Myocardial tissues were sampled to analyze the distribution of Cx43 using immunofluorescence; the Cx43 content was analyzed using western blot analysis; and the MMP-2 and MMP-9 activity in the myocardium was analyzed using gelatin zymography. The distribution of Cx43 in the border of the infarcted myocardia in the MI and MP groups was clearly disrupted and the Cx43 content was significantly reduced. In addition, the distribution of Cx43 in the border of the infarct in the DOX group was relatively regular, whereas two weeks of DOX treatment significantly inhibited MMP activity. Meanwhile, the induction rate of arrhythmia in the rats after DOX treatment was lower than those in the MI and MP groups. The results show that DOX treatment after myocardial infarction improves gap junction remodeling in the myocardial tissue near the infarcted area by inhibiting MMP activity and reducing susceptibility to cardiac arrhythmia. [ABSTRACT FROM AUTHOR]

Two chiral copper(II) complexes [Cu(L)2Cl]Cl ( 1) and [Cu(L)2Br]Br ( 2) {L = N-[(pyridin-2-ylmethylene)imino]dehydroabietylamine} have been synthesized and fully characterized. The coordination geometry of the CuII ions in 1 and 2 can be described as an intermediate between square-pyramidal and trigonal-bipyramidal. DNA binding studies suggest that the complexes interact with salmon-sperm DNA through intercalation, and 2 exhibits a higher binding affinity. The new complexes were screened for their antibacterial and cytotoxic ability. They have similar cytotoxic activity and they represent the first rosin-derivative-based simple Schiff base complexes with strong anticancer potential. [ABSTRACT FROM AUTHOR]

Monte Carlo simulations are performed to study the phase diagram of liquid crystals formed by bent-core molecules with a strong transverse dipole moment deviating from their angular bisector. The results show that the strong dipolar interaction, after suppressing uniaxial phases, encourages biaxiality, which leads to a Landau point or even to a Landau line in the phase diagram, inducing a more stable biaxial nematic phase. It is also found that a deviation of dipole moment from the angular bisector also suppresses uniaxiality in the small bend-angle regime. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two new 2,2′-bipyridine-based binuclear Cu (II) complexes have been synthesized. [•] The binary complex shows stronger binding affinity to DNA. [•] The two complexes bind to DNA via intercalation. [•] Their in vitro cytotoxicity reflects their DNA binding strength order. [•] Thermodynamic parameters indicate that the binding reactions are hydrophobic. [Copyright &y& Elsevier]

Lithium (Li)‐magnesium (Mg) alloy with limited Mg amount, which can also be called Mg‐doped Li (Li‐Mg), has been considered as a potential alternative anode for high energy density rechargeable Li metal batteries. However, the optimum doping‐content of Mg in Li‐Mg anode and the mechanism of the improved performance are not well understood. Herein, density functional theory (DFT) calculations are used to investigate the effect of Mg amount in Li‐Mg anode. The Li‐Mg with about 5 wt. % Mg (abbreviated as Li‐Mg5) has the lowest absorption energy of Li, thus all the surface area can be "controlled" by Mg atoms, leading to the smooth and continuous deposition of Li on the surface around the Mg center. A localized high concentration electrolyte enables Li‐Mg5 to exhibit the best cycling stability in Li metal batteries with high‐loading cathode and lean electrolyte under 4.4 V high‐voltage, which is approaching the demand of practical application. This electrolyte also helps generate an inorganic‐rich solid electrolyte interphase, which leads to smooth, compact and less corrosion layer on the Li‐Mg5 surface. Both theoretical simulations and experimental results prove that Li‐Mg5 has optimum Mg content and gives best battery cycling performance. [ABSTRACT FROM AUTHOR]

Lithium (Li)‐magnesium (Mg) alloy with limited Mg amount, which can also be called Mg‐doped Li (Li‐Mg), has been considered as a potential alternative anode for high energy density rechargeable Li metal batteries. However, the optimum doping‐content of Mg in Li‐Mg anode and the mechanism of the improved performance are not well understood. Herein, density functional theory (DFT) calculations are used to investigate the effect of Mg amount in Li‐Mg anode. The Li‐Mg with about 5 wt. % Mg (abbreviated as Li‐Mg5) has the lowest absorption energy of Li, thus all the surface area can be "controlled" by Mg atoms, leading to the smooth and continuous deposition of Li on the surface around the Mg center. A localized high concentration electrolyte enables Li‐Mg5 to exhibit the best cycling stability in Li metal batteries with high‐loading cathode and lean electrolyte under 4.4 V high‐voltage, which is approaching the demand of practical application. This electrolyte also helps generate an inorganic‐rich solid electrolyte interphase, which leads to smooth, compact and less corrosion layer on the Li‐Mg5 surface. Both theoretical simulations and experimental results prove that Li‐Mg5 has optimum Mg content and gives best battery cycling performance. [ABSTRACT FROM AUTHOR]

Despite being an effective flame retardant, trimethyl phosphate (TMPa) is generally considered as an unqualified solvent for fabricating electrolytes used in graphite (Gr)‐based lithium‐ion batteries as it readily leads to Gr exfoliation and cell failure. In this work, by adopting the unique solvation structure of localized high‐concentration electrolyte (LHCE) to TMPa and tuning the composition of the solvation sheaths via electrolyte additives, excellent electrochemical performance can be achieved with TMPa‐based electrolytes in Gr∥LiNi0.8Mn0.1Co0.1O2 cells. After 500 charge/discharge cycles within the voltage range of 2.5–4.4 V, the batteries containing the TMPa‐based LHCE with a proper additive can achieve a capacity retention of 85.4 %, being significantly higher than cells using a LiPF6‐organocarbonates baseline electrolyte (75.2 %). Meanwhile, due to the flame retarding effect of TMPa, TMPa‐based LHCEs exhibit significantly reduced flammability compared with the conventional LiPF6‐organocarbonates electrolyte. [ABSTRACT FROM AUTHOR]

Despite being an effective flame retardant, trimethyl phosphate (TMPa) is generally considered as an unqualified solvent for fabricating electrolytes used in graphite (Gr)‐based lithium‐ion batteries as it readily leads to Gr exfoliation and cell failure. In this work, by adopting the unique solvation structure of localized high‐concentration electrolyte (LHCE) to TMPa and tuning the composition of the solvation sheaths via electrolyte additives, excellent electrochemical performance can be achieved with TMPa‐based electrolytes in Gr∥LiNi0.8Mn0.1Co0.1O2 cells. After 500 charge/discharge cycles within the voltage range of 2.5–4.4 V, the batteries containing the TMPa‐based LHCE with a proper additive can achieve a capacity retention of 85.4 %, being significantly higher than cells using a LiPF6‐organocarbonates baseline electrolyte (75.2 %). Meanwhile, due to the flame retarding effect of TMPa, TMPa‐based LHCEs exhibit significantly reduced flammability compared with the conventional LiPF6‐organocarbonates electrolyte. [ABSTRACT FROM AUTHOR]

[Display omitted] An ever-increasing market for electric vehicles (EVs), electronic devices and others has brought tremendous attention on the need for high energy density batteries with reliable electrochemical performances. However, even the successfully commercialized lithium (Li)-ion batteries still face significant challenges with respect to cost and safety issues when they are used in EVs. From a cathode material point of view, layered transition-metal (TM) oxides, represented by LiMO 2 (M = Ni, Mn, Co, Al, etc.) and Li-/Mn-rich x Li 2 MnO 3 ·(1– x)LiMO 2 , have been considered as promising candidates because of their high theoretical capacity, high operating voltage, and low manufacturing cost. However, layered TM oxides still have not reached their full potential for EV applications due to their intrinsic stability issues during electrochemical processes. To address these problems, a variety of surface modification strategies have been pursued in the literature. Herein, we summarize the recent progresses on the enhanced stability of layered TM oxides cathode materials by different surface modification techniques, analyze the manufacturing process and cost of the surface modification methods, and finally propose future research directions in this area. [ABSTRACT FROM AUTHOR]

[Display omitted] Rechargeable lithium (Li) metal batteries (LMBs) with ultrahigh-nickel (Ni) layered oxide cathodes offer a great opportunity for applications in electrical vehicles. However, increasing Ni content inherently arouses a tradeoff between specific capacity and electrochemical cyclability due to the aggressive side reactions with electrolyte contributed by the highly reactive Ni species. Here, a protective and stable cathode/electrolyte interphase featuring enriched and evenly-distributed LiF is in situ formed on ultrahigh-Ni cathode LiNi 0.94 Co 0.06 O 2 (NC) with an advanced ether-based localized high-concentration electrolyte (LHCE), which concurrently shows good compatibility with Li metal anode. Subsequently, the NC cathode can deliver high capacity retentions of 81.4% after 500 cycles at 25 °C and 91.6% after 100 cycles at 60 °C in the voltage range of 2.8–4.4 V in Li||NC cells at 1C cycling rate (1.5 mA cm−2). Meanwhile, the conductive electrode/electrolyte interphases formed in LHCE enable a high reversible capacity of about 209 mAh g−1 at 3C charging rate. This work provides an effective approach and important insight from the perspective of in situ ultrahigh-Ni cathode/electrolyte interphase protection for high energy–density, long-lasting LMBs. [ABSTRACT FROM AUTHOR]

Lithium metal batteries (LMBs) are one of the most promising candidates for next‐generation high‐energy‐density rechargeable batteries. Solid electrolyte interphase (SEI) on Li metal anodes plays a significant role in influencing the Li deposition morphology and the cycle life of LMBs. However, a thorough understanding on the mechanisms of SEI formation and evolution is still inadequate. In this review, the progress in understanding structures, properties, and influencing factors of SEI, as well as efficient strategies of tailoring SEI are focused upon. First, the compositions, models, and recent progress in characterizing atomic structures of SEI are summarized. Second, the properties of SEI, including electronic conduction, ionic conduction, stability, and mechanical properties are elucidated. Structures and properties of SEI are greatly affected by multiple factors, thus interactions between these factors and SEI are systematically discussed. Correlations of SEI with Li deposition morphology, rate capability, and cycle life are further summarized. Moreover, efficient strategies of tailoring SEI with desired properties, including in situ SEI and ex situ SEI, are also reviewed. Finally, future directions, including in‐operando techniques, multi‐modality approaches for characterization of SEI, and artificial intelligence assisted understanding of correlations between electrolyte components and SEI properties are proposed. [ABSTRACT FROM AUTHOR]

Abstract: The stabilities of different conductive carbon additives have been systematically investigated in high voltage lithium ion batteries. It is found that the higher surface area of conductive additives leads to more parasitic reactions initiating from different onset voltages. A closer inspection reveals that for the low surface area carbon such as Super P, anions reversibly intercalate into carbon structure at around 4.7 V. For high surface area carbons, in addition to the electrolyte decomposition, the oxidation of functional groups at high voltage further increases the irreversible capacity and Li+ ion consumption. Coulombic efficiency, irreversible capacity and cycling stability observed by using different carbon additives are correlated with their structure and surface chemistry, thus providing information for predictive selection of carbon additives in different energy storage systems. [Copyright &y& Elsevier]

Inorganic-organic composite electrolyte membranes were fabricated from CsXH3-XPMo12O40 (CsPOMo) and quaternary diazabicyclo-octane polysulfone (QDPSU) using a polytetrafluoroethylene (PTFE) porous matrix for the application of intermediate temperature fuel cells. The CsPOMo/QDPSU/PTFE composite membrane was made proton conducting by using a relatively low phosphoric acid loading, which benefits the stability of the membrane conductivity and the mechanical strength. The casting method was used in order to build a thin and robust composite membrane. The resulting composite membrane films were characterised in terms of the elemental composition, membrane structure and morphology by EDX, FTIR and SEM. The proton conductivity of the membrane was 0.04 S cm-1 with a H3PO4 loading level of 1.8 PRU (amount of H3PO4 per repeat unit of polymer QDPSU). The fuel cell performance with the membrane gave a peak power density of 240 mW cm-2 at 150 °C and atmospheric pressure. [ABSTRACT FROM AUTHOR]

We study the effective interactions between nanoparticles immersed in an athermal polymer solution using Molecular dynamics. The directly measured polymer-induced depletion forces are well described with a scaling model in which the attraction between particles is caused by the depletion of concentration blobs and thus independent of the length of the polymer chains. We find strong evidence for a repulsive barrier which arises when the distance between the particles is of the order of the correlation length of the solution and which can be interpreted as a packing effect of concentration blobs. Interestingly, the scaling picture can be extended into the regime in which higher virial coefficients of the polymer solution become relevant. We derive a universal relation between the attraction force at the particle contact, f(0), and the osmotic pressure Π as f(0) ~ Π2/3, demonstrating its validity over a wide range of concentrations of the polymer solution. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we report the electrochemical characteristics of a novel cathode material, Li2CoPO4F, prepared by solid-state reactions. The solid-state reaction mechanism involved in synthesizing the Li2CoPO4F also is analyzed in this paper. When cycled between 2.0V and 5.0V during cyclic voltammetry measurements, the Li2CoPO4F samples present one, fully reversible anodic reaction at 4.81V. When cycled between 2.0V and 5.5V, peaks occurring at 4.81V and 5.12V in the first anodic scan evolved to one broad oxidative, mound-like pattern in subsequent cycles. Correspondingly, the X-ray diffraction (XRD) pattern of the Li2CoPO4F electrode discharged from 5.5V to 2.0V is slightly different from the patterns exhibited by a fresh sample and the sample discharged from 5.0V to 2.0V. This difference may correspond to a structural relaxation that appears above 5V. In the constant current cycling measurements, the Li2CoPO4F samples exhibited a capacity as high as 109mAhg−1 and maintained a good cyclability between 2.0V and 5.5V vs. Li/Li+. XRD measurements confirmed that the discharged state is Li2CoPO4F. Combining these XRD results and electrochemical data proved that up to 1mol Li+ is extractable when charged to 5.5V. [ABSTRACT FROM AUTHOR]

Abstract: In this work, Li/air batteries based on nonaqueous electrolytes were investigated in ambient conditions (with an oxygen partial pressure of 0.21atm and relative humidity of ∼20%). A heat-sealable polymer membrane was used as both an oxygen-diffusion membrane and as a moisture barrier for Li/air batteries. The membrane also can minimize the evaporation of the electrolyte from the batteries. Li/air batteries with this membrane can operate in ambient conditions for more than one month with a specific energy of 362Whkg−1, based on the total weight of the battery including its packaging. Among various carbon sources used in this work, Li/air batteries using Ketjenblack (KB) carbon-based air electrodes exhibited the highest specific energy. However, KB-based air electrodes expanded significantly and absorbed much more electrolyte than electrodes made from other carbon sources. The weight distribution of a typical Li/air battery using the KB-based air electrode was dominated by the electrolyte (∼70%). Lithium metal anodes and KB-carbon account for only 5.12% and 5.78% of the battery weight, respectively. We also found that only ∼20% of the mesopore volume of the air electrode was occupied by reaction products after discharge. To further improve the specific energy of the Li/air batteries, the microstructure of the carbon electrode needs to be further improved to absorb much less electrolyte while still holding significant amounts of reaction products. [Copyright &y& Elsevier]

A facile and efficient synthesis of polysubstituted benzenes has been developed viasequential Michael addition, Knoevenagel condensation and nucleophilic cyclization reactions of readily available chalcones with active methylene compounds in guanidinium ionic liquids. [ABSTRACT FROM AUTHOR]

Abstract: The synthesis of mercuric mercaptide of penicillenic acid (MMPA) has been the basis for detection of penicillin for nearly 40years (J. Pharm. Pharmacol., 1972, 24, 790; Chinese Pharmacopoeia Ed. II, 1995). Herein, experiments were performed on: (1) synthesis of MMPA used as a novel mercuric hapten, (2) preparation of mercuric antigen of MMPA-BSA, (3) production of antibodies by rabbits immunized with the antigen, and (4) properties of the antibodies studied by ELISA. The results show that: (1) the antigen is safe for immunized animals; (2) high titer antibodies against MMPA are obtained implying good immunogenicity of the antigen; (3) antisera show slightly higher affinity to OVA-GHS-HgCl than OVA-GSH, indicating weak specific affinity of antisera against mercuric ion. Even the weak specific affinity, the hapten and its antigen have potential uses in immunoassays of mercuric ion in environment and food samples, because of easy chemical selective conversion from mercuric ion to MMPA and complete decomposition of un-reacted penicillin in acidic solution. [Copyright &y& Elsevier]

The common inhalation anesthetic isoflurane has been shown to induce apoptosis, which then leads to accumulation of β-amyloid protein, the hallmark feature of Alzheimer disease neuropathogenesis. The underlying molecular mechanism of the isoflurane-induced apoptosis is largely unknown. We, therefore, set out to assess whether isoflurane can induce apoptosis by regulating Bcl-2 family proteins, enhancing reactive oxygen species (ROS) accumulation, and activating the mitochondrial pathway of apoptosis. We performed these studies in cultured cells, primary neurons, and mice. Here we show for the first time that treatment with 2% isoflurane for 6 h can increase pro-apoptotic factor Bax levels, decrease anti-apoptotic factor Bcl-2 levels, increase ROS accumulation, facilitate cytochrome c release from the mitochondria to the cytosol, induce activation of caspase-9 and caspase-3, and finally cause apoptosis as compared with the control condition. We have further found that isoflurane can increase the mRNA levels of Bax and reduce the mRNA levels of Bcl-2. The isoflurane-induced ROS accumulation can be attenuated by the intracellular calcium chelator BAPTA. Finally, the anesthetic desfiurane does not induce activation of mitochondrial pathway of apoptosis. These results suggest that isoflurane may induce apoptosis through Bcl-2 family proteins- and ROS-associated mitochondrial pathway of apoptosis. These findings, which have identified at least partially the molecular mechanism by which isoflurane induces apoptosis, will promote more studies aimed at studying the potential neurotoxic effects of anesthetics. [ABSTRACT FROM AUTHOR]

The article focuses on a study which evaluates the effects of nitrous oxide and isoflurane on apoptosis and beta-amyloid levels in human neuroglioma cells and primary neurons from mice. In this study, cells or neurons and conditioned media that are exposed to nitrous oxide and isoflurane are harvested at the end of the treatment. Researchers determine the caspase-3 activation, apoptosis, processing of amyloid precursor protein (APP) and beta-amyloid levels. They conclude that apoptosis can enhance aspartyl protease beta-site APP-cleaving enzyme (BACE) levels to help APP processing.

Most previous studies have focused on the effect of fertility selection on the evolution of cooperation. In fact, the payoff to an individual is in terms of the effect on fitness including survival and fecundity. In this paper, we introduce a model of strategy evolution with network dynamics based on mortality selection. The intensity β of mortality selection has a nontrivial role in the evolution of both cooperation and network structure. At a defector's temptation b = 1, the system gains its maximal cooperation level at β → ∞. Increasing b decreases βmax for the maximal cooperation level. For network structure, the average degrees of strategists and the self-organization of clusters are investigated to understand the connections of strategists and their effects on cooperation level. Furthermore, we introduce the cooperating k-core to describe the tight level of the cooperator cluster. Cooperation is enhanced by forming a tight cooperating k-core at moderate β, but there is a collapse of the cooperating k-core when is too large. The results indicate that cooperators outside the cooperating k-core play an important role in maintaining that core to ensure a high cooperation level. So the formation and maintenance of the cooperating k-core coordinate with each other at maximum cooperation level at a specific value of β. [ABSTRACT FROM AUTHOR]

N,N-Di-tert-butoxycarbonylpyridin-4-amines were found to be rearranged to tert-butyl 4-(tert-butoxycarbonylamino)nicotinates by treatment with LDA in THF. [ABSTRACT FROM AUTHOR]

N-Heterocyclic carbenes (NHCs) were demonstrated to be efficient catalysts for the Staudinger reaction of ketenes with N-tosyl, N-benzyloxycarbonyl, or N-tert-butoxycarbonyl imines. Chiral NHC 8b, conveniently prepared from l-pyroglutamic acid, catalyzed the reactions of arylalkylketenes with a variety of N-tert-butoxycarbonyl arylimines to give the corresponding cis--lactams in good yields with good diastereoselectivities and excellent enantioselectivities (up to 99% ee). Two possible catalytic pathways, initiated by the addition of NHC to ketenes or imines, were discussed. [ABSTRACT FROM AUTHOR]

BACKGROUND: The Kell blood group system consists of 25 antigens that result from single-nucleotide polymorphisms. Most polymorphic Kell antigens reside on the N-terminal domain of Kell before the zinc-binding catalytic motif, which is the major site for endothelin-3–converting enzyme activity. Kell antigens are important in transfusion medicine owing to their strong immunogenicity, and the corresponding antibodies are clinically significant. Two probands were studied whose serum samples contained antibodies to different high-prevalence Kell antigens. STUDY DESIGN AND METHODS: Standard hemagglutination methods were used for serologic testing of Proband 1 and Proband 2. DNA was prepared from both probands and family members. The 19 exons and the intron-exon regions of KEL from both probands were amplified by polymerase chain reaction, and the sequences were compared with that of common KEL. The identified substitutions were located on a three-dimensional model of Kell generated based on the crystal structure of neutral endopeptidase, a homolog of Kell. RESULTS: In Proband 1, a homozygous 1988G>A mutation (Arg623Lys) in Exon 17 was present. One sibling of Proband 1 was homozygous for 1988G>A. In Proband 2, a homozygous 1033G>A mutation (Asp305Asn) in Exon 8 was present. Three siblings of Proband 2 were heterozygous for 1033G>A. CONCLUSION: The identified KEL mutations of the two probands are novel and inherited. The antigen absent from the red blood cells (RBCs) of Probands 1 and 2 are named KALT and KTIM, respectively. KALT is unique in that it is the only Kell antigen sensitive to treatment of RBCs by trypsin. [ABSTRACT FROM AUTHOR]

This study explores the role of candidate news releases, media content, and public opinion in shaping the salience of political issues and candidate images during the 2002 Florida gubernatorial election. The study analyzed 77 news releases, 654 newspaper stories, and public opinion data from a statewide survey of 572 respondents. Significant correlations were found supporting both first- and second-level agenda building and agenda-setting effects. Theoretical and practical implications of the findings are discussed. [ABSTRACT FROM AUTHOR]

Agenda-setting theory, a conceptual framework used to trace how issue salience is established among policy makers, media, and the public, has yet to be applied to political socialization. This study extends agenda-setting theory by conceptualizing it as a process of political development. In an analysis of adolescent involvement during the 2002 US. elections, data are reported from a quasi-experimental field study of the effects of the Kids Voting USA campaign intervention on students in Arizona, Colorado, and Florida. A model of agenda setting among adolescents is built by investigating the influence of school intervention exposure, news attention, discussion, and information integration on salience, opinion strength, and finally strengthened political predispositions (partisanship and ideology). Findings suggest that agenda setting provides a valuable perspective for understanding how adolescents come to decide what issues are important to them. [ABSTRACT FROM AUTHOR]

Abstract: A novel blue-emitting material, fine-particle phosphor (Y,Gd)P0.5V0.5O4:Tm3+, has been prepared via co-precipitation reaction. The phosphor particles were characterized by XRD, SEM, and photoluminescence under vacuum ultraviolet (VUV, 147nm) or ultraviolet (UV, 254nm) excitation. The XRD patterns disclosed that (Y,Gd)P0.5V0.5O4:Tm3+ particles calcined at 1200°C have the highest intensity. The SEM image showed that the size of the phosphor particles is uniform and submicron, and their morphology is regular and no agglomeration found. The fine particles blue-emitting material exhibits a narrow emission peak at 475nm and a weak broad-band around 430nm, whose intensity is dependent on the contents of Tm3+ and VO4 3−. [Copyright &y& Elsevier]

A stable electrolyte is critical for practical application of lithium–oxygen batteries (LOBs). Although the ionic conductivity and electrochemical stability of the electrolytes have been extensively investigated before, their oxygen solubility, viscosity, volatility, and the stability against singlet oxygen (1O2) still need to be comprehensively investigated to provide a full picture of the electrolytes, especially for an open system such as LOBs. Herein, a systematic investigation is reported on the localized high‐concentration electrolytes (LHCEs) using different fluorinated diluents in comparison with those of conventional electrolytes. The physical properties and activation energies for reactions with singlet oxygen (1O2) of these electrolytes are calculated by density functional theory. The electrochemical performances of LOBs using these electrolytes are compared. This study reveals that the correlation between the stability of the electrolytes and their physical and electrochemical properties depends strongly on the diluents in LHCEs. Therefore, it shines light on the rational design of new electrolytes for LOBs. [ABSTRACT FROM AUTHOR]

Inflammation is essential for the pathological process of acute lung injury (ALI). Trilobatin, a glycosylated dihydrochalcone can show anti-oxidative and anti-inflammation properties. This study aimed to explore whether trilobatin could suppress inflammation in lipopolysaccharide (LPS)-induced ALI. Firstly, mice were injected with trilobatin intraperitoneally, and then LPS was administered intranasally to induce lung injury. Data from analysis of lung edema and pathologic histology of lung tissues indicated that pretreatment with trilobatin alleviated LPS-induced histopathological changes and decreased wet-to-dry weight (W/D) ratio. Moreover, LPS-induced lung injury was attenuated post trilobatin treatment with reduced protein concentration, cell numbers, neutrophils and macrophages in BALF (bronchoalveolar lavage fluid). Secondly, trilobatin treatment decreased the protein level of tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β) thereby suppressing LPS-induced inflammation. LPSinduced oxidative stress was ameliorated following trilobatin treatment with decreased malondialdehyde (MDA) and increased glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT). Lastly, trilobatin decreased NF-κB phosphorylation and increased Nrf2 through up-regulation of AMPK and GSK3β phosphorylation. In conclusion, trilobatin repressed oxidative stress and inflammatory damage by ameliorating LPSinduced ALI through activation of AMPK/GSK3β-Nrf2 and inhibition of NF-κB. [ABSTRACT FROM AUTHOR]

Dysmenorrhea is a common gynecological disease. Acupuncture under the guidance of TCM the ory has a significant effect on it. This study analyzed the present situation of acupuncture and moxibustion treatment of dysmenorrhea, including acupoints, correlation of point selection, and mechanism. [ABSTRACT FROM AUTHOR]

To enable next‐generation high‐power, high‐energy‐density lithium (Li) metal batteries (LMBs), an electrolyte possessing both high Li Coulombic efficiency (CE) at a high rate and good anodic stability on cathodes is critical. Acetonitrile (AN) is a well‐known organic solvent for high anodic stability and high ionic conductivity, yet its application in LMBs is limited due to its poor compatibility with Li metal anodes even at high salt concentration conditions. Here, a highly concentrated AN‐based electrolyte is developed with a vinylene carbonate (VC) additive to suppress Li+ depletion at high current densities. Addition of VC to the AN‐based electrolyte leads to the formation of a polycarbonate‐based solid electrolyte interphase, which minimizes Li corrosion and leads to a very high Li CE of up to 99.2% at a current density of 0.2 mA cm‐2. Using such an electrolyte, fast charging of Li||NMC333 cells is realized at a high current density of 3.6 mA cm‐2, and stable cycling of Li||NMC622 cells with a high cathode loading of 4 mAh cm‐2 is also demonstrated. [ABSTRACT FROM AUTHOR]

LiNixMnyCo1−x−yO2 (NMC) cathode materials with Ni ≥ 0.8 have attracted great interest for high energy‐density lithium‐ion batteries (LIBs) but their practical applications under high charge voltages (e.g., 4.4 V and above) still face significant challenges due to severe capacity fading by the unstable cathode/electrolyte interface. Here, an advanced electrolyte is developed that has a high oxidation potential over 4.9 V and enables NMC811‐based LIBs to achieve excellent cycling stability in 2.5–4.4 V at room temperature and 60 °C, good rate capabilities under fast charging and discharging up to 3C rate (1C = 2.8 mA cm−2), and superior low‐temperature discharge performance down to −30 °C with a capacity retention of 85.6% at C/5 rate. It is also demonstrated that the electrode/electrolyte interfaces, not the electrolyte conductivity and viscosity, govern the LIB performance. This work sheds light on a very promising strategy to develop new electrolytes for fast‐charging high‐energy LIBs in a wide‐temperature range. [ABSTRACT FROM AUTHOR]

Environmental neurotoxins such as paraquat (PQ), manganese, and 1-1-methyl-4-phenyl- 1,2,3,6-tetrahydropyridine (MPTP) are associated with a higher risk of Parkinson's disease (PD). These parkinsonian toxins exert certain common toxicological effects on astroglia; however, their role in the regulatory functions of astroglial secretory proteins remains unclear. In a previous study, we observed that secretogranin II (SCG2) and secretogranin III (SCG3), which are important components of the regulated secretory pathway, were elevated in PQ-activated U118 astroglia. In the current study, we used the parkinsonian toxins dopamine (DA), active metabolite of MPTP (MPP+), MnCl2, and lipopolysaccharide (LPS) as inducers, and studied the potential regulation of SCG2 and SCG3. Our results showed that all the parkinsonian toxins except LPS affected astroglial viability but did not cause apoptosis. Exposure to DA, MPP+, and MnCl2 upregulated glial fibrillary acidic protein (GFAP), a marker for astrocyte activation, and stimulated the levels of several astrocytic-derived factors. Further, DA, MPP+, and MnCl2 exposure impeded astroglial cell cycle progression. Moreover, the expression of SCG3 was elevated, while its exosecretion was inhibited in astroglia activated by parkinsonian toxins. The level of SCG2 remained unchanged. In combination with our previous findings, the results of this study indicate that SCG3 may act as a cofactor in astrocyte activation stimulated by various toxins, and the regulation of SCG3 could be involved in the toxicological mechanism by which parkinsonian toxins affect astroglia. [ABSTRACT FROM AUTHOR]

Upon ultraviolet (UV) light excitation, an intense near-infrared (NIR) emission of Yb3+ (2F5/2→2F7/2) around 980 nm is observed in YVO4:Yb3+ phosphors. Owing to host absorption of YVO4, a broad excitation band ranging from 250 to 350 nm is recorded when the Yb3+ emission was monitored, which suggests an efficient energy transfer from host to Yb3+ ions. The Yb3+ concentration dependence of the visible vanadate emission as well as the Yb3+ emission is investigated. The decay curve of vanadate emission is measured under the excitation of a 266 nm pulsed laser. The decay time of the vanadate emission at 500 nm is remarkably reduced by introducing Yb3+ ions, further verifying that the energy transfer from the vanadate host to the Yb3+ ions is very efficient. Cooperative energy transfer (CET) is discussed as a possible mechanism for the NIR emission. The YVO4:Yb3+ phosphor can convert each UV photon into two NIR photons via CET, which has potential application in the high efficiency silicon-based solar cells. [ABSTRACT FROM AUTHOR]

A series of niobate-phosphate and niobate-silicate glasses doped with Eu[sup 3+] ions were prepared. The emissions, phonon-side band spectra, and fluorescence lifetimes of these glasses were studied and the intensity parameters of Eu[sup 3+] were obtained. The temperature dependence of emission intensity of the Eu[sup 3+] ion in these niobate glasses was investigated. The temperature-quenching rates were determined. The results indicate that in niobate glasses, as the concentration of Nb[sub 2]O[sub 5] increases, the covalence becomes stronger, the symmetry becomes lower and the electron-phonon coupling strength becomes stronger. Thus, the lifetimes become shorter, and the nonradiative transition processes and the temperature-quenching effect become stronger. [ABSTRACT FROM AUTHOR]

The temperature dependence of emission intensity of the Eu[sup 3+] ion in several silicate glasses was investigated between 77 and 670 K, under the excitation of a 488-nm laser. It was observed that in some glasses the total emission intensity of the Eu[sup 3+] ion had a maximum at a certain temperature below 670 K, while in the other glasses increased monotonically with the increasing temperature. A unified theoretical model was given considering thermal activation, phonon-assisted absorption and nonradiative energy transfer processes. Based on the model, all of the experimental data were well fitted. The temperature-quenching channels were discussed, and the temperature-quenching rates were determined. [ABSTRACT FROM AUTHOR]

The article discusses the adverse effects of tumor necrosis factor-α in acute myocardial infarction patients. It mentions a study conducted by researcher J.H. Fu and colleagues as per which, acute myocardial ischemia and reperfusion led to an increase in TNF-α content. It cites another study led by Y.Q. Zhen and colleagues as per which, TNF-α concentration in myocardial infarction were high in comparison to coronary artery legation group.

Bark beetles and their associated fungi, which cause forest decline and sometimes high mortality in large areas around the world, are of increasing concern in terms of forest health. Three Tomicus spp. (T. brevipilosus, T. minor and T. yunnanensis) infect branches and trunks of Pinus yunnanensis and P. kesiya in Yunnan Province, in south-western China. Tomicus spp. are well known as vectors of ophiostomatoid fungi and their co-occurrence could result in serious ecological and economic impact on local forest ecosystems. Nonetheless, knowledge about their diversity, ecology, including pathogenicity and potential economic importance is still quite rudimentary. Therefore, an extensive survey of ophiostomatoid fungi associated with these Tomicus species infesting P. yunnanensis and P. kesiya was carried out in Yunnan. Seven hundred and seventy-two strains of ophiostomatoid fungi were isolated from the adult beetles and their galleries. The strains were identified based on comparisons of multiple DNA sequences, including the nuclear ribosomal large subunit (LSU) region, the internal transcribed spacer regions 1 and 2, together with the intervening 5.8S gene (ITS) and the partial genes of ß-tubulin (TUB2), elongation factor 1a (TEF1-a) and calmodulin (CAL). Phylogenetic analyses were performed using maximum parsimony (MP) as well as maximum likelihood (ML). Combinations of culture features, morphological characters and temperature-dependent growth rates were also employed for species identification. Eleven species belonging to five genera were identified. These included six known species, Esteya vermicola, Leptographium yunnanense, Ophiostoma brevipilosi, O. canum, O. minus and O. tingens and four novel taxa, described as Graphilbum anningense, O. aggregatum, Sporothrix pseudoabietina and S. macroconidia. A residual strain was left unidentified as Ophiostoma sp. 1. The overall ophiostomatoid community was by far dominated by three species, representing 87.3% of the total isolates; in decreasing order, these were O. canum, O. brevipilosi and O. minus. Furthermore, the ophiostomatoid community of each beetle, although harbouring a diversity of ophiostomatoid species, was differentially dominated by a single fungal species; Ophiostoma canum was preferentially associated with and dominated the ophiostomatoid community of T. minor, whereas O. brevipilosi and O. minus were exclusively associated with and dominated the ophiostomatoid communities of T. brevipilosus and T. yunnanensis, respectively. Eight additional species, representing the remaining 12.7% of the total isolates, were marginal or sporadic. These results suggested that sympatric Tomicus populations are dominated by distinct species showing some level of specificity or even exclusivity. [ABSTRACT FROM AUTHOR]

Highlights • Flame spread over the wavy surface of corrugated cardboard was modeled using direct numerical simulation. • Comparisons between flame spread on the flat surface and the wavy surface were made in detail. • The 'B' and 'C' flute cardboards were simulated to analyze the effect of wavy structure on the spreading flame. Abstract The corrugated cardboards have been widely used in warehouse where flame spread over its surface consisting of the flat layer and the wavy layer contributes more hazards once fire disaster happens. This paper therefore performs a numerical investigation to study upward flame spread over the cardboards with wavy structures. Comparisons between upward flame spread over the flat surface and the wavy surface of corrugated cardboards were made on the flame characteristics, flame spread rate, standoff distance, local burning rate and flame splitting. It is found that the flame gets closer to the wavy surface and a larger averaged temperature gradient is exerted on the surface, which causes the fuel to burn with a higher rate. The wavy structure is the main reason that causes a distinct difference between the flat surface and the corrugated surface, and it promotes the flame to split into more small flames, thus leading the flame to move faster. To validate the model results, experiments on the flame spreading over the fuel with wavy structure were conducted, which were in good agreement with the simulation. The results can provide a solid basis on which to guide the stacking of goods in warehouse in the future. [ABSTRACT FROM AUTHOR]

Down-regulation of p16INK4a and miR-146b-5p contributes to tumorigenesis in osteosarcoma (OS). However, the correlation between p16INK4a and miR-146b-5p in OS proliferation remains largely unknown. In the present study, we demonstrated that miR-146b-5p expression was positively correlated with p16INK4a in OS, but inversely correlated with TNF receptor associated factor 6 (TRAF6) expression. Overexpression of miR-146b-5p dramatically suppressed OS cell proliferation. Mechanistically, we validated TRAF6 as a direct functional target of miR-146b-5p and found that miR-146b-5p overexpression significantly decreased the level of phosphorylated PI3k and Akt, which are the pivotal downstream effectors of TRAF6. Moreover, TRAF6 expression was positively correlated with Ki-67 but inversely correlated with miR-146b-5p expression. In OS cells, silencing of TRAF6 mimicked the anti-tumor effects of miR-146b-5p. p16INK4a is an important tumor suppressor gene frequently down-regulated in OS.We found that this inhibitory effect is associated with the suppression of the miR-146b-5p, and is mediated via up-regulating TRAF6 expression. Our findings identified p16INK4a and miR-146b-5p as tumor suppressors, and suggested p16INK4a, miR-146b-5p and TRAF6 as potential therapeutic candidates for malignant OS. [ABSTRACT FROM AUTHOR]

Abstract Irreversible parasitic reactions and the resulting accumulation of insulating side products are main barriers for practical application of rechargeable lithium–oxygen (Li O 2) batteries. Therefore, it is critical to develop multifunctional oxygen electrodes suitable for oxygen reduction reaction, oxygen evolution reaction, and decomposition of side reaction products. Here we report the application of ultrafine ruthenium on boron carbide (Ru/B 4 C) with highly efficient multifunctional activities as carbon-free oxygen electrodes for Li O 2 batteries. Li 2 CO 3 and LiOH can be completely decomposed by Ru/B 4 C at 4.0 V and 4.1 V, respectively, within the stability window of the electrolyte. A Li O 2 battery using the Ru/B 4 C oxygen electrode achieves low overpotentials for Li O 2 reactions, and excellent cycling performance under the capacities of 300 and 500 mAh g−1 Ru/B4C. In-situ gas chromatography analysis reveals that O 2 is the major gas product during charging. Only a negligible amount of CO 2 is observed in the first charging process. Therefore, Ru/B 4 C can be a very promising oxygen-electrode material for Li O 2 batteries and Li–air batteries operated in ambient air. Graphical abstract Image 1 Highlights • Non-carbon-based Ru/B 4 C oxygen electrode shows good activity for both ORR and OER. • Ru/B 4 C can completely decompose Li 2 CO 3 and LiOH below 4.1 V. • Ru/B 4 C is very stable against superoxide radical anion and Li 2 O 2. • Li O 2 batteries using Ru/B 4 C oxygen electrodes exhibit long cycling stability. • Side reaction during charge accounts for degradation of Ru/B 4 C oxygen electrode. [ABSTRACT FROM AUTHOR]

Highlights • X-ray photoelectron spectroscopy can provide atomistic and microscopic view of chemical speciation and distribution at complexelectrode-electrolyte interfaces. • Identifying the reactant and products of decomposition reaction can help evaluate the longevity of electrolyte and subsequent life cycle of battery. • Novelin situ XPS can provide real time view of electrode-electrolyte interphase formation and help us correlate the battery failure mechanisms. Abstract Technological development requires reliable power sources where energy storage devices are emerging as a critical component. Wide range of energy storage devices, Redox-flow batteries (RFB), Lithium ion based batteries (LIB), and Lithium-sulfur (LSB) batteries are being developed for various applications ranging from grid-scale level storage to mobile electronics. Material complexities associated with these energy storage devices with unique electrochemistry are formidable challenge which needs to be address for transformative progress in this field. X-ray photoelectron spectroscopy (XPS) - a powerful surface analysis tool - has been widely used to study these energy storage materials because of its ability to identify, quantify and image the chemical distribution of redox active species. However, accessing the deeply buried solid-electrolyte interfaces (which dictates the performance of energy storage devices) has been a challenge in XPS usage. Herein we report our recent efforts to utilize the XPS to gain deep insight about these interfaces under realistic conditions with varying electrochemistry involving RFB, LIB and LSB. [ABSTRACT FROM AUTHOR]

Abstract Experiments were conducted to evaluate the inhibition efficiency of dimethyl methylphosphonate (DMMP) on methane/air coflow diffusion flames. An optical diagnostic system (hydroxyl planar laser-induced fluorescence) was used to measure the OH radical distribution in the flames. The minimum extinguishing concentration (MEC) of CO 2 , as a function of DMMP addition, was measured to characterize the inhibition efficiency of DMMP. Results show that, when the concentration of DMMP is higher than 0.6%, DMMP's marginal inhibition efficiency reduces to almost zero. It is found that the normalized peak OH concentrations keep unchanged with a value of 0.9 for flames at conditions near extinction limit. This is firstly observed based on experimental measurements. Furthermore, using DMMP alone cannot extinguish the flame even with 4.59% DMMP addition. When the inhibition efficiency of DMMP gets saturated, a large amount of phosphorus-containing molecules agglomerate around the flame. These particles act as sinks for the active phosphorus-containing species with a high inertial force, which are hard to diffuse horizontally into the flame. Therefore, it is concluded that the generation of the particles is a reason for the saturation phenomenon of DMMP in extinguishing the coflow diffusion flames. [ABSTRACT FROM AUTHOR]

A new method for continuous separation of microparticles in viscoelastic fluid is reported. A series of sharp corners were fabricated at one side of a microchannel, which induced the curved streamline and the asymmetric distribution of the elastic force. The Newtonian sheath flow was utilized to squeeze microparticles to the side wall with sharp corners at the inlet. Particles were subjected to inertial forces, elastic force and viscous drag force, all of which pointed to the straight wall side. Stronger forces were exerted on larger particles, leading to size-dependent migration of particles across the interface between the Newtonian and the viscoelastic fluids. The influence of the flow rate ratio on the particle separation was also studied. The results show that the sharp corners and the co-flowing fluid system significantly enhanced particle lateral migration, achieving complete particle separation at a low flow rate and in a short channel length. The particle separation efficiency was further increased at a higher flow rate ratio (sheath flow/sample flow). With a simple structure and small footprint, this device has great potential to be used in a variety of particle separation processes for lab-on-a-chip applications. [ABSTRACT FROM AUTHOR]