Environmental Molecular Sciences Laboratory

About: Environmental Molecular Sciences Laboratory is a facility organization based out in Richland, Washington, United States. It is known for research contribution in the topics: Mass spectrometry & Ion. The organization has 1471 authors who have published 3010 publications receiving 169961 citations.

Hybrid Organic/Inorganic Copolymers with Strongly Hydrogen-Bond Acidic Properties for Acoustic Wave and Optical Sensors

Abstract: Hybrid organic/inorganic polymers have been prepared incorporating fluoroalkyl-substituted bisphenol groups linked using oligosiloxane spacers. These hydrogen-bond acidic materials have glass-to-rubber transition temperatures below room temperature and are excellent sorbents for basic vapors. The physical properties such as viscosity and refractive index can be tuned by varying the length of the oligosiloxane spacers and the molecular weight. In addition, the materials are easily cross-linked to yield solid elastomers. The potential use of these materials for chemical sensing has been demonstrated by applying them to surface acoustic wave devices as thin films and detecting the hydrogen-bond basic vapor dimethyl methylphosphonate with high sensitivity. It has also been demonstrated that one of these materials with suitable viscosity and refractive index can be used to clad silica optical fibers; the cladding was applied to freshly drawn fiber using a fiber drawing tower. These fibers have potential as eva...

Theoretical Study of Cation/Ether Complexes: Alkali Metal Cations with 1,2-Dimethoxyethane and 12-Crown-4

Abstract: Hartree−Fock and second-order perturbation theory methods were used to determine structures and binding enthalpies of complexes formed from a single alkali metal cation (Li+ through Cs+) and one or two 1,2-dimethoxyethane ligands or 12-crown-4. These calculations employed multiple basis sets in order to determine the sensitivity of the results to the completeness in the one-particle basis. The results are compared with recently reported collision-induced dissociation experimental findings. In general, good agreement was found between the experimental and theoretical bond dissociation enthalpies, although for the heavier cations discrepancies of as much as 14 kcal/mol or more were uncovered. Possible reasons for these anomalies are discussed.

Behavior of nanoceria in biologically-relevant environments

Abstract: Cerium oxide nanoparticles (nanoceria) have gained considerable attention in biological research due to their anti-oxidant like behaviour and regenerative nature. The current literature on nanoceria reports many successful attempts on harnessing the beneficial therapeutic properties in biology. However studies have also shown toxicity with some types of nanoceria. This article discusses issues associated with the behaviours of nanoceria in biological systems and identifies key knowledge gaps. We explore how salient physico-chemical properties (size, surface chemistry, surface stabilizers) of nanoceria corresponds to its behaviour in biological relevant buffers and cell culture media, and this can provide guidelines for potential positive and negative aspects of nanoceria in biological systems. Based on variations of results reported in the literature, important issues need to be addressed. Are we really studying the same particles with slight variations in size and physico-chemical properties or do the particles being examined have fundamentally different behaviours? Are the variations observed the result of differences in the initial properties of the particles or the results of downstream effects that emerge as the particles are prepared for specific studies and they interact with biological or other environmental moieties? How should particles be appropriately prepared for relevant environmental/toxicology/safety studies? It is useful to recognize that nanoparticles encompass some of the same complexities and variability associated with biological components.

Spatio-temporal microbial community dynamics within soil aggregates.

Abstract: Soil microbial communities are highly spatially organized, shaped in part by the structure of soil itself. Understanding how spatially discrete microbial communities change across years and seasons in response to environmental factors, plant phenology and aggregate turnover, is key to understanding how varying management practices impact the ecology of soil microbial communities. We investigated both seasonal (within year) and annual (across sampling years) changes of discrete microbial communities in soil aggregate fractions, large macroaggregates (LM) and microaggregates (MICRO) in three different bioenergy management systems. We hypothesized that 1) seasonal changes due to plant phenology and aggregate turnover will be most pronounced within the MICRO aggregate soil microbial community; 2) inter-annual variability will lead to changes in microbial diversity across aggregate sizes and the magnitude of change will be mediated by management regime. We found that LM and MICRO aggregates have unique microbial communities within soil. MICRO aggregate microbial communities are more diverse and change more dynamically across the sampling season, peaking in diversity at peak plant growth and maximum biomass. The number of families indicative of specific MICRO aggregate habitats increases over the growing season for both bacteria (from 3 to 51) and fungi (from 8 to 14). The LM aggregates harbored less diverse, yet more stable, communities within a growing season. By contrast, between years the LM aggregates were the most responsive to inter-annual variability. Our study demonstrates the importance of including the spatio-temporal dynamics of soil microbes. We identified “hot spots” of microbial diversity within soil, with a greater diversity of microbes found under prairies, within the MICRO aggregates, and seasonally during peak plant biomass. Targeted analysis of the MICRO aggregates can contribute to deeper understanding of potential diversity and functioning of soil microbial communities for ecosystem maintenance as well as the response to climatic events and environmental change.