Highly Concentrated Electrolytes: Electrochemical and Physicochemical Characteristics of LiPF6 in Propylene Carbonate Solutions

Highly concentrated electrolytes (HCEs) based on LiPF6 in propylene carbonate (PC) have been examined as lithium-ion battery electrolytes. These HCEs have lower ionic conductivities and higher viscosities than ethylene carbonate (EC) electrolytes with 1.2 M LiPF6, but they have higher Li+ ion transference numbers. Electrochemical cycling behaviour of LiNi0.8C0.015Al0.05O2//graphite cells with 3.2 M LiPF6 in PC resembles that of cells with EC-based electrolytes; the HCE cells have higher impedance, which can be lowered by increasing test temperature. By employing Raman and infrared spectroscopy, combined with density functional theory and ab initio molecular dynamics simulations, we reveal that the Li+ solvation structure and speciation are key factors that determine cell performance. Two distinct regimes are observed as a function of salt concentration-in the conventional regime, the solvation number (SN) is mostly constant, while in the HCE regime it decreases linearly. Graphite exfoliation is suppressed only at very high salt concentrations (>2.4 M), where [PC](free)/[Li+] < 1 and [PF6-](free) > [PC](free). Results from the Advanced Electrolyte Model indicate that Li+ desolvation improves at higher LiPF6 concentrations, thereby mitigating PC co-intercalation into the graphite. However, Li+ ion transport is hindered in the HCEs, which increases impedance at both the oxide-positive and graphite-negative electrodes

Tree Species Traits Influence Soil Physical, Chemical, and Biological Properties in High Elevation Forests

BACKGROUND: Previous studies have shown that plants often have species-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single tree species are often adjacent to areas dominated by another tree species. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce, which are dominant tree species in this region and are distributed widely in North America. We hypothesized that soil properties would differ among stands dominated by different tree species and expected that aspen stands would have higher soil temperatures due to their open structure, which, combined with higher quality litter, would result in increased soil respiration rates, nitrogen availability, and microbial biomass, and differences in soil faunal community composition. METHODOLOGY/PRINCIPAL FINDINGS: We assessed soil physical, chemical, and biological properties at four sites where stands of aspen, pine, and spruce occurred in close proximity to one-another in the San Juan Mountains, Colorado. Leaf litter quality differed among the tree species, with the highest nitrogen (N) concentration and lowest lignin:N in aspen litter. Nitrogen concentration was similar in pine and spruce litter, but lignin:N was highest in pine litter. Soil temperature and moisture were highest in aspen stands, which, in combination with higher litter quality, probably contributed to faster soil respiration rates from stands of aspen. Soil carbon and N content, ammonium concentration, and microbial biomass did not differ among tree species, but nitrate concentration was highest in aspen soil and lowest in spruce soil. In addition, soil fungal, bacterial, and nematode community composition and rotifer, collembolan, and mesostigmatid mite abundance differed among the tree species, while the total abundance of nematodes, tardigrades, oribatid mites, and prostigmatid mites did not. CONCLUSIONS/SIGNIFICANCE: Although some soil characteristics were unaffected by tree species identity, our results clearly demonstrate that these dominant tree species are associated with soils that differ in several physical, chemical, and biotic properties. Ongoing environmental changes in this region, e.g. changes in fire regime, frequency of insect outbreaks, changes in precipitation patterns and snowpack, and land-use change, may alter the relative abundance of these tree species over coming decades, which in turn will likely alter the soils

Heme Oxygenase-1 Expression Affects Murine Abdominal Aortic Aneurysm Progression.

Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme degradation, is a cytoprotective enzyme upregulated in the vasculature by increased flow and inflammatory stimuli. Human genetic data suggest that a diminished HO-1 expression may predispose one to abdominal aortic aneurysm (AAA) development. In addition, heme is known to strongly induce HO-1 expression. Utilizing the porcine pancreatic elastase (PPE) model of AAA induction in HO-1 heterozygous (HO-1+/-, HO-1 Het) mice, we found that a deficiency in HO-1 leads to augmented AAA development. Peritoneal macrophages from HO-1+/- mice showed increased gene expression of pro-inflammatory cytokines, including MCP-1, TNF-alpha, IL-1-beta, and IL-6, but decreased expression of anti-inflammatory cytokines IL-10 and TGF-beta. Furthermore, treatment with heme returned AAA progression in HO-1 Het mice to a wild-type profile. Using a second murine AAA model (Ang II-ApoE-/-), we showed that low doses of the HMG-CoA reductase inhibitor rosuvastatin can induce HO-1 expression in aortic tissue and suppress AAA progression in the absence of lipid lowering. Our results support those studies that suggest that pleiotropic statin effects might be beneficial in AAA, possibly through the upregulation of HO-1. Specific targeted therapies designed to induce HO-1 could become an adjunctive therapeutic strategy for the prevention of AAA disease

Índices para monitorização de qualidade ecológica de costas rochosas com base em comunidades de macroalgas : simplificação para utilização em áreas geográficas alargadas

Copyright © 2013 APRH.Este estudo centra-se em características de comunidades de macroalgas do intertidal rochoso para avaliação da qualidade ecológica das massas de águas costeiras no âmbito da Diretiva-Quadro da Água (DQA). É proposto um índice alternativo aos desenvolvidos nas Ilhas Britânicas, no norte da Espanha e em Portugal continental, que resulta da comparação da aplicação de todos os índices a um conjunto de dados recolhidos em praias açorianas, discutindo-se a adequação dos parâmetros utilizados em cada índice. Os parâmetros incluídos no índice proposto foram selecionados de forma a permitir a sua aplicação numa área geográfica alargada.ABSTRACT: This study focuses on intertidal rocky shore seaweed community features used for the assessment of ecological quality of coastal water bodies for the Water Framework Directive (WFD). An alternative index to those developed in the British Isles, in northern Spain and in mainland Portugal is proposed. Results from the application of all indices to a dataset collected on Azorean shores are compared and the suitability of the features used in each index discussed. The features included in the proposed index were selected to allow its applicability throughout a large geographic area

FCC testing at bench scale: New units, new processes, new feeds

As the FCC process has evolved over decades, several laboratory scale equipment have appeared to maintain a proper assessment of catalysts activity. Several laboratory equipments are available for simulating the FCC process, from the well known fixed bed, MicroActivity Test to newer, fluid bed or transported bed units. As well, a number of units have been created to simulate other parts of the process such as regenerator or stripper, The increased pressure for treating non-conventional feeds, from reprocessing gasoline to extra-heavy feeds or oils produced from biomass containing large amounts of heteroatoms, increase the needs to have a laboratory test which is as close as possible to the process so that data extraction from the laboratory test are simplified, thus less prone to errors or misunderstanding.Financial support by MICINN (Consolider-Ingenio 2010 MULTICAT) and MINECO (Project MAT2011-29020-0O2-02 and Subprogram for excellence Severo Ochoa, SEV 2012 0267) is gratefully acknowledged.Corma Canós, A.; Sauvanaud, LL. (2013). FCC testing at bench scale: New units, new processes, new feeds. Catalysis Today. 218-219:107-114. doi:10.1016/j.cattod.2013.03.038S107114218-21

Excited State Dynamics of Bistridentate and Trisbidentate RuII Complexes of Quinoline-Pyrazole Ligands

Three homoleptic ruthenium(II) complexes, [Ru(Q3PzH)3]2+, [Ru(Q1Pz)3]2+, and [Ru(DQPz)2]2+, based on the quinoline-pyrazole ligands, Q3PzH (8-(3-pyrazole)-quinoline), Q1Pz (8-(1-pyrazole)-quinoline), and DQPz (bis(quinolinyl)-1,3-pyrazole), have been spectroscopically and theoretically investigated. Spectral component analysis, transient absorption spectroscopy, density functional theory calculations, and ligand exchange reactions with different chlorination agents reveal that the excited state dynamics for Ru(II) complexes with these biheteroaromatic ligands differ significantly from that of traditional polypyridyl complexes. Despite the high energy and low reorganization energy of the excited state, nonradiative decay dominates even at liquid nitrogen temperatures, where triplet metal-to-ligand-charge-transfer emission quantum yields range from 0.7 to 3.8%, and microsecond excited state lifetimes are observed. In contrast to traditional polypyridyl complexes where ligand exchange is facilitated by expansion of the metal-ligand bonds to stabilize a metal-centered state, photoinduced ligand exchange occurs in the bidentate complexes despite no substantial MC state population, while the tridentate complex is extremely photostable despite an activated decay route, highlighting the versatile photochemistry of nonpolypyridine ligands.\ua0\ua9 2019 American Chemical Society

Mortality among World Trade Center rescue and recovery workers, 2002-2011

BACKGROUND: Rescue and recovery workers responding to the 2001 collapse of the World Trade Center (WTC) sustained exposures to toxic chemicals and have elevated rates of multiple morbidities. METHODS: Using data from the World Trade Center Health Program and the National Death Index for 2002-2011, we examined standardized mortality ratios (SMR) and proportional cancer mortality ratios (PCMR) with indirect standardization for age, sex, race, and calendar year to the U.S. general population, as well as associations between WTC-related environmental exposures and all-cause mortality. RESULTS: We identified 330 deaths among 28,918 responders (SMR 0.43, 95%CI 0.39-0.48). No cause-specific SMRs were meaningfully elevated. PCMRs were elevated for neoplasms of lymphatic and hematopoietic tissue (PCMR 1.76, 95%CI 1.06-2.75). Mortality hazard ratios showed no linear trend with exposure. CONCLUSIONS: Consistent with a healthy worker effect, all-cause mortality among responders was not elevated. There was no clear association between intensity and duration of exposure and mortality. Surveillance is needed to monitor the proportionally higher cancer mortality attributed to lymphatic/hematopoietic neoplasms

Differential Growth Responses of Soil Bacterial Taxa to Carbon Substrates of Varying Chemical Recalcitrance

Soils are immensely diverse microbial habitats with thousands of co-existing bacterial, archaeal, and fungal species. Across broad spatial scales, factors such as pH and soil moisture appear to determine the diversity and structure of soil bacterial communities. Within any one site however, bacterial taxon diversity is high and factors maintaining this diversity are poorly resolved. Candidate factors include organic substrate availability and chemical recalcitrance, and given that they appear to structure bacterial communities at the phylum level, we examine whether these factors might structure bacterial communities at finer levels of taxonomic resolution. Analyzing 16S rRNA gene composition of nucleotide analog-labeled DNA by PhyloChip microarrays, we compare relative growth rates on organic substrates of increasing chemical recalcitrance of >2,200 bacterial taxa across 43 divisions/phyla. Taxa that increase in relative abundance with labile organic substrates (i.e., glycine, sucrose) are numerous (>500), phylogenetically clustered, and occur predominantly in two phyla (Proteobacteria and Actinobacteria) including orders Actinomycetales, Enterobacteriales, Burkholderiales, Rhodocyclales, Alteromonadales, and Pseudomonadales. Taxa increasing in relative abundance with more chemically recalcitrant substrates (i.e., cellulose, lignin, or tannin–protein) are fewer (168) but more phylogenetically dispersed, occurring across eight phyla and including Clostridiales, Sphingomonadalaes, Desulfovibrionales. Just over 6% of detected taxa, including many Burkholderiales increase in relative abundance with both labile and chemically recalcitrant substrates. Estimates of median rRNA copy number per genome of responding taxa demonstrate that these patterns are broadly consistent with bacterial growth strategies. Taken together, these data suggest that changes in availability of intrinsically labile substrates may result in predictable shifts in soil bacterial composition

Influence of the 6^1S_0-6^3P_1 Resonance on Continuous Lyman-alpha Generation in Mercury

Continuous coherent radiation in the vacuum-ultraviolet at 122 nm (Lyman-alpha) can be generated using sum-frequency mixing of three fundamental laser beams in mercury vapour. One of the fundamental beams is at 254 nm wavelength, which is close to the 6^1S_0-6^3P_1 resonance in mercury. Experiments have been performed to investigate the effect of this one-photon resonance on phasematching, absorption and the nonlinear yield. The efficiency of continuous Lyman-alpha generation has been improved by a factor of 4.5.Comment: 8 pages, 7 figure