Particulate matter chemical component concentrations and sources in settings of household solid fuel use.

PubMed

Secrest, M H; Schauer, J J; Carter, E M; Baumgartner, J

2017-11-01

Particulate matter (PM) air pollution derives from combustion and non-combustion sources and consists of various chemical species that may differentially impact human health and climate. Previous reviews of PM chemical component concentrations and sources focus on high-income urban settings, which likely differ from the low- and middle-income settings where solid fuel (ie, coal, biomass) is commonly burned for cooking and heating. We aimed to summarize the concentrations of PM chemical components and their contributing sources in settings where solid fuel is burned. We searched the literature for studies that reported PM component concentrations from homes, personal exposures, and direct stove emissions under uncontrolled, real-world conditions. We calculated weighted mean daily concentrations for select PM components and compared sources of PM determined by source apportionment. Our search criteria yielded 48 studies conducted in 12 countries. Weighted mean daily cooking area concentrations of elemental carbon, organic carbon, and benzo(a)pyrene were 18.8 μg m -3 , 74.0 μg m -3 , and 155 ng m -3 , respectively. Solid fuel combustion explained 29%-48% of principal component/factor analysis variance and 41%-87% of PM mass determined by positive matrix factorization. Multiple indoor and outdoor sources impacted PM concentrations and composition in these settings, including solid fuel burning, mobile emissions, dust, and solid waste burning. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

ENHANCED AIR POLLUTION EPIDEMIOLOGY USING A SOURCE-ORIENTED CHEMICAL TRANSPORT MODEL

EPA Science Inventory

Air quality model predictions describing source-oriented PM component concentrations in multiple size cuts will provide new inputs to examine the effects of acute and chronic PM exposure on mortality and morbidity. Associations between adverse health effects and PM sources/com...

Identification of chemical components of combustion emissions that affect pro-atherosclerotic vascular responses in mice

PubMed Central

Seilkop, Steven K.; Campen, Matthew J.; Lund, Amie K.; McDonald, Jacob D.; Mauderly, Joe L.

2012-01-01

Combustion emissions cause pro-atherosclerotic responses in apolipoprotein E-deficient (ApoE/−) mice, but the causal components of these complex mixtures are unresolved. In studies previously reported, ApoE−/− mice were exposed by inhalation 6 h/day for 50 consecutive days to multiple dilutions of diesel or gasoline exhaust, wood smoke, or simulated “downwind” coal emissions. In this study, the analysis of the combined four-study database using the Multiple Additive Regression Trees (MART) data mining approach to determine putative causal exposure components regardless of combustion source is reported. Over 700 physical–chemical components were grouped into 45 predictor variables. Response variables measured in aorta included endothelin-1, vascular endothelin growth factor, three matrix metalloproteinases (3, 7, 9), metalloproteinase inhibitor 2, heme-oxygenase-1, and thiobarbituric acid reactive substances. Two or three predictors typically explained most of the variation in response among the experimental groups. Overall, sulfur dioxide, ammonia, nitrogen oxides, and carbon monoxide were most highly predictive of responses, although their rankings differed among the responses. Consistent with the earlier finding that filtration of particles had little effect on responses, particulate components ranked third to seventh in predictive importance for the eight response variables. MART proved useful for identifying putative causal components, although the small number of pollution mixtures (4) can provide only suggestive evidence of causality. The potential independent causal contributions of these gases to the vascular responses, as well as possible interactions among them and other components of complex pollutant mixtures, warrant further evaluation. PMID:22486345

Identification of chemical components of combustion emissions that affect pro-atherosclerotic vascular responses in mice.

PubMed

Seilkop, Steven K; Campen, Matthew J; Lund, Amie K; McDonald, Jacob D; Mauderly, Joe L

2012-04-01

Combustion emissions cause pro-atherosclerotic responses in apolipoprotein E-deficient (ApoE/⁻) mice, but the causal components of these complex mixtures are unresolved. In studies previously reported, ApoE⁻/⁻ mice were exposed by inhalation 6 h/day for 50 consecutive days to multiple dilutions of diesel or gasoline exhaust, wood smoke, or simulated "downwind" coal emissions. In this study, the analysis of the combined four-study database using the Multiple Additive Regression Trees (MART) data mining approach to determine putative causal exposure components regardless of combustion source is reported. Over 700 physical-chemical components were grouped into 45 predictor variables. Response variables measured in aorta included endothelin-1, vascular endothelin growth factor, three matrix metalloproteinases (3, 7, 9), metalloproteinase inhibitor 2, heme-oxygenase-1, and thiobarbituric acid reactive substances. Two or three predictors typically explained most of the variation in response among the experimental groups. Overall, sulfur dioxide, ammonia, nitrogen oxides, and carbon monoxide were most highly predictive of responses, although their rankings differed among the responses. Consistent with the earlier finding that filtration of particles had little effect on responses, particulate components ranked third to seventh in predictive importance for the eight response variables. MART proved useful for identifying putative causal components, although the small number of pollution mixtures (4) can provide only suggestive evidence of causality. The potential independent causal contributions of these gases to the vascular responses, as well as possible interactions among them and other components of complex pollutant mixtures, warrant further evaluation.

Analysis of the multiple system with chemically peculiar component φ Draconis

NASA Astrophysics Data System (ADS)

Liška, J.

2016-09-01

The star ϕ Dra comprises a spectroscopic binary and a third star that together form a visual triple system. It is one of the brightest chemically peculiar stars of the upper main sequence. Despite these facts, no comprehensive study of its multiplicity has been performed yet. In this work, we present a detailed analysis of the triple system based on available measurements. We use radial velocities taken from four sources in the literature in a re-analysis of the inner spectroscopic binary (Aab). An incorrect value of the orbital period of the inner system Aab about 27 d was accepted in literature more than 40 yr. A new solution of orbit with the 128-d period was determined. Relative position measurements of the outer visual binary system (AB) from Washington Double Star Catalog were compared with known orbital models. Furthermore, it was shown that astrometric motion in system AB is well described by the model of Andrade with a 308-yr orbital period. Parameters of A and B components were utilized to estimate individual brightness for all components and their masses from evolutionary tracks. Although we found several facts which support the gravitational bond between them, unbound solution cannot be fully excluded yet.

Reconstruction of interatomic vectors by principle component analysis of nuclear magnetic resonance data in multiple alignments

NASA Astrophysics Data System (ADS)

Hus, Jean-Christophe; Bruschweiler, Rafael

2002-07-01

A general method is presented for the reconstruction of interatomic vector orientations from nuclear magnetic resonance (NMR) spectroscopic data of tensor interactions of rank 2, such as dipolar coupling and chemical shielding anisotropy interactions, in solids and partially aligned liquid-state systems. The method, called PRIMA, is based on a principal component analysis of the covariance matrix of the NMR parameters collected for multiple alignments. The five nonzero eigenvalues and their eigenvectors efficiently allow the approximate reconstruction of the vector orientations of the underlying interactions. The method is demonstrated for an isotropic distribution of sample orientations as well as for finite sets of orientations and internuclear vectors encountered in protein systems.

XML Encoding of Features Describing Rule-Based Modeling of Reaction Networks with Multi-Component Molecular Complexes

PubMed Central

Blinov, Michael L.; Moraru, Ion I.

2011-01-01

Multi-state molecules and multi-component complexes are commonly involved in cellular signaling. Accounting for molecules that have multiple potential states, such as a protein that may be phosphorylated on multiple residues, and molecules that combine to form heterogeneous complexes located among multiple compartments, generates an effect of combinatorial complexity. Models involving relatively few signaling molecules can include thousands of distinct chemical species. Several software tools (StochSim, BioNetGen) are already available to deal with combinatorial complexity. Such tools need information standards if models are to be shared, jointly evaluated and developed. Here we discuss XML conventions that can be adopted for modeling biochemical reaction networks described by user-specified reaction rules. These could form a basis for possible future extensions of the Systems Biology Markup Language (SBML). PMID:21464833

Engineering interfacial photo-induced charge transfer based on nanobamboo array architecture for efficient solar-to-chemical energy conversion.

PubMed

Wang, Xiaotian; Liow, Chihao; Bisht, Ankit; Liu, Xinfeng; Sum, Tze Chien; Chen, Xiaodong; Li, Shuzhou

2015-04-01

Engineering interfacial photo-induced charge transfer for highly synergistic photocatalysis is successfully realized based on nanobamboo array architecture. Programmable assemblies of various components and heterogeneous interfaces, and, in turn, engineering of the energy band structure along the charge transport pathways, play a critical role in generating excellent synergistic effects of multiple components for promoting photocatalytic efficiency. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pieces of the Puzzle: Tracking the Chemical Component of the ...

EPA Pesticide Factsheets

This presentation provides an overview of the risk assessment conducted at the U.S. EPA, as well as some research examples related to the exposome concept. This presentation also provides the recommendation of using two organizational and predictive frameworks for tracking chemical components in the exposome. The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates data, decision-support tools, and models to be applied to media-specific or receptor-specific problem areas. CED uses modeling-based approaches to characterize exposures, evaluate fate and transport, and support environmental diagnostics/forensics with input from multiple data sources. It also develops media- and receptor-specific models, process models, and decision support tools for use both within and outside of EPA.

Chemical Composition of Fine Particulate Matter and Life Expectancy

PubMed Central

Dominici, Francesca; Wang, Yun; Correia, Andrew W.; Ezzati, Majid; Pope, C. Arden; Dockery, Douglas W.

2016-01-01

Background In a previous study, we provided evidence that a decline in fine particulate matter (PM2.5) air pollution during the period between 2000 and 2007 was associated with increased life expectancy in 545 counties in the United States. In this article, we investigated which chemical constituents of PM2.5 were the main drivers of the observed association. Methods We estimated associations between temporal changes in seven major components of PM2.5 (ammonium, sulfate, nitrate, elemental carbon matter, organic carbon matter, sodium, and silicon) and temporal changes in life expectancy in 95 counties between 2002 and 2007. We included US counties that had adequate chemical components of PM2.5 mass data across all seasons. We fitted single pollutant and multiple pollutant linear models, controlling for available socioeconomic, demographic, and smoking variables and stratifying by urban and nonurban counties. Results In multiple pollutant models, we found that: (1) a reduction in sulfate was associated with an increase in life expectancy; and (2) reductions in ammonium and sodium ion were associated with increases in life expectancy in nonurban counties only. Conclusions Our findings suggest that recent reductions in long-term exposure to sulfate, ammonium, and sodium ion between 2002 and 2007 are associated with improved public health. PMID:25906366

Chemical Composition of Fine Particulate Matter and Life Expectancy: In 95 US Counties Between 2002 and 2007.

PubMed

Dominici, Francesca; Wang, Yun; Correia, Andrew W; Ezzati, Majid; Pope, C Arden; Dockery, Douglas W

2015-07-01

In a previous study, we provided evidence that a decline in fine particulate matter (PM2.5) air pollution during the period between 2000 and 2007 was associated with increased life expectancy in 545 counties in the United States. In this article, we investigated which chemical constituents of PM2.5 were the main drivers of the observed association. We estimated associations between temporal changes in seven major components of PM2.5 (ammonium, sulfate, nitrate, elemental carbon matter, organic carbon matter, sodium, and silicon) and temporal changes in life expectancy in 95 counties between 2002 and 2007. We included US counties that had adequate chemical components of PM2.5 mass data across all seasons. We fitted single pollutant and multiple pollutant linear models, controlling for available socioeconomic, demographic, and smoking variables and stratifying by urban and nonurban counties. In multiple pollutant models, we found that: (1) a reduction in sulfate was associated with an increase in life expectancy; and (2) reductions in ammonium and sodium ion were associated with increases in life expectancy in nonurban counties only. Our findings suggest that recent reductions in long-term exposure to sulfate, ammonium, and sodium ion between 2002 and 2007 are associated with improved public health.

Toward a scientific understanding of the effectiveness, material basis and prescription compatibility of a Chinese herbal formula Dan-hong injection

PubMed Central

Li, Panlin; Su, Weiwei; Yun, Sha; Liao, Yiqiu; Liao, Yinyin; Liu, Hong; Li, Peibo; Wang, Yonggang; Peng, Wei; Yao, Hongliang

2017-01-01

Since traditional Chinese medicine (TCM) is a complex mixture of multiple components, the application of methodologies for evaluating single-components Western medicine in TCM studies may have certain limitations. Appropriate strategies that recognize the integrality of TCM and connect to TCM theories remain to be developed. Here we use multiple unique approaches to study the scientific connotation of a TCM formula Dan-hong injection (DHI) without undermining its prescription integrity. The blood circulation improving and healing promoting effects of DHI were assessed by a qi stagnation blood stasis rat model and a mouse model of laser irradiation induced cerebral microvascular thrombosis. By UFLC-PDA-Triple Q-TOF-MS/MS and relevance analysis between chemical characters and biological effects, 82 chemical constituents and nine core components, whose blood circulation promoting effects were found comparable to that of whole DHI, were successfully identified. What’s more, the rationality of DHI prescription compatibility could be reflected not only in the maximum efficacy of the original ratio, but also in the interactions of compounds from different ingredient herbs, such as complementary activities and facilitating tissues distribution. This study provides scientific evidences in explanation of the clinical benefits of DHI, and also gives a good demonstration for the comprehensive evaluation of other TCM. PMID:28393856

Thermal Response Of Composite Insulation

NASA Technical Reports Server (NTRS)

Stewart, David A.; Leiser, Daniel B.; Smith, Marnell; Kolodziej, Paul

1988-01-01

Engineering model gives useful predictions. Pair of reports presents theoretical and experimental analyses of thermal responses of multiple-component, lightweight, porous, ceramic insulators. Particular materials examined destined for use in Space Shuttle thermal protection system, test methods and heat-transfer theory useful to chemical, metallurgical, and ceramic engineers needing to calculate transient thermal responses of refractory composites.

Multiple-division of self-propelled oil droplets through acetal formation.

PubMed

Banno, Taisuke; Kuroha, Rie; Miura, Shingo; Toyota, Taro

2015-02-28

We demonstrate a novel system that exhibits both self-propelled motion and division of micrometer-sized oil droplets induced by chemical conversion of the system components. Such unique dynamics were observed in an oil-in-water emulsion of a benzaldehyde derivative, an alkanol and a cationic surfactant at a low pH.

High throughput screening using acoustic droplet ejection to combine protein crystals and chemical libraries on crystallization plates at high density

DOE PAGES

Teplitsky, Ella; Joshi, Karan; Ericson, Daniel L.; ...

2015-07-01

We describe a high throughput method for screening up to 1728 distinct chemicals with protein crystals on a single microplate. Acoustic droplet ejection (ADE) was used to co-position 2.5 nL of protein, precipitant, and chemicals on a MiTeGen in situ-1 crystallization plate™ for screening by co-crystallization or soaking. ADE-transferred droplets follow a precise trajectory which allows all components to be transferred through small apertures in the microplate lid. The apertures were large enough for 2.5 nL droplets to pass through them, but small enough so that they did not disrupt the internal environment created by the mother liquor. Using thismore » system, thermolysin and trypsin crystals were efficiently screened for binding to a heavy-metal mini-library. Fluorescence and X-ray diffraction were used to confirm that each chemical in the heavy-metal library was correctly paired with the intended protein crystal. Moreover, a fragment mini-library was screened to observe two known lysozyme We describe a high throughput method for screening up to 1728 distinct chemicals with protein crystals on a single microplate. Acoustic droplet ejection (ADE) was used to co-position 2.5 nL of protein, precipitant, and chemicals on a MiTeGen in situ-1 crystallization plate™ for screening by co-crystallization or soaking. ADE-transferred droplets follow a precise trajectory which allows all components to be transferred through small apertures in the microplate lid. The apertures were large enough for 2.5 nL droplets to pass through them, but small enough so that they did not disrupt the internal environment created by the mother liquor. Using this system, thermolysin and trypsin crystals were efficiently screened for binding to a heavy-metal mini-library. Fluorescence and X-ray diffraction were used to confirm that each chemical in the heavy-metal library was correctly paired with the intended protein crystal. A fragment mini-library was screened to observe two known lysozyme ligands using both co-crystallization and soaking. A similar approach was used to identify multiple, novel thaumatin binding sites for ascorbic acid. This technology pushes towards a faster, automated, and more flexible strategy for high throughput screening of chemical libraries (such as fragment libraries) using as little as 2.5 nL of each component.ds using both co-crystallization and soaking. We used a A similar approach to identify multiple, novel thaumatin binding sites for ascorbic acid. This technology pushes towards a faster, automated, and more flexible strategy for high throughput screening of chemical libraries (such as fragment libraries) using as little as 2.5 nL of each component.« less

Multivariate classification of small order watersheds in the Quabbin Reservoir Basin, Massachusetts

USGS Publications Warehouse

Lent, R.M.; Waldron, M.C.; Rader, J.C.

1998-01-01

A multivariate approach was used to analyze hydrologic, geologic, geographic, and water-chemistry data from small order watersheds in the Quabbin Reservoir Basin in central Massachusetts. Eighty three small order watersheds were delineated and landscape attributes defining hydrologic, geologic, and geographic features of the watersheds were compiled from geographic information system data layers. Principal components analysis was used to evaluate 11 chemical constituents collected bi-weekly for 1 year at 15 surface-water stations in order to subdivide the basin into subbasins comprised of watersheds with similar water quality characteristics. Three principal components accounted for about 90 percent of the variance in water chemistry data. The principal components were defined as a biogeochemical variable related to wetland density, an acid-neutralization variable, and a road-salt variable related to density of primary roads. Three subbasins were identified. Analysis of variance and multiple comparisons of means were used to identify significant differences in stream water chemistry and landscape attributes among subbasins. All stream water constituents were significantly different among subbasins. Multiple regression techniques were used to relate stream water chemistry to landscape attributes. Important differences in landscape attributes were related to wetlands, slope, and soil type.A multivariate approach was used to analyze hydrologic, geologic, geographic, and water-chemistry data from small order watersheds in the Quabbin Reservoir Basin in central Massachusetts. Eighty three small order watersheds were delineated and landscape attributes defining hydrologic, geologic, and geographic features of the watersheds were compiled from geographic information system data layers. Principal components analysis was used to evaluate 11 chemical constituents collected bi-weekly for 1 year at 15 surface-water stations in order to subdivide the basin into subbasins comprised of watersheds with similar water quality characteristics. Three principal components accounted for about 90 percent of the variance in water chemistry data. The principal components were defined as a biogeochemical variable related to wetland density, an acid-neutralization variable, and a road-salt variable related to density of primary roads. Three subbasins were identified. Analysis of variance and multiple comparisons of means were used to identify significant differences in stream water chemistry and landscape attributes among subbasins. All stream water constituents were significantly different among subbasins. Multiple regression techniques were used to relate stream water chemistry to landscape attributes. Important differences in landscape attributes were related to wetlands, slope, and soil type.

High resolution Physio-chemical Tissue Analysis: Towards Non-invasive In Vivo Biopsy

NASA Astrophysics Data System (ADS)

Xu, Guan; Meng, Zhuo-Xian; Lin, Jian-Die; Deng, Cheri X.; Carson, Paul L.; Fowlkes, J. Brian; Tao, Chao; Liu, Xiaojun; Wang, Xueding

2016-02-01

Conventional gold standard histopathologic diagnosis requires information of both high resolution structural and chemical changes in tissue. Providing optical information at ultrasonic resolution, photoacoustic (PA) technique could provide highly sensitive and highly accurate tissue characterization noninvasively in the authentic in vivo environment, offering a replacement for histopathology. A two-dimensional (2D) physio-chemical spectrogram (PCS) combining micrometer to centimeter morphology and chemical composition simultaneously can be generated for each biological sample with PA measurements at multiple optical wavelengths. This spectrogram presents a unique 2D “physio-chemical signature” for any specific type of tissue. Comprehensive analysis of PCS, termed PA physio-chemical analysis (PAPCA), can lead to very rich diagnostic information, including the contents of all relevant molecular and chemical components along with their corresponding histological microfeatures, comparable to those accessible by conventional histology. PAPCA could contribute to the diagnosis of many diseases involving diffusive patterns such as fatty liver.

Multivariate Statistical Analysis of MSL APXS Bulk Geochemical Data

NASA Astrophysics Data System (ADS)

Hamilton, V. E.; Edwards, C. S.; Thompson, L. M.; Schmidt, M. E.

2014-12-01

We apply cluster and factor analyses to bulk chemical data of 130 soil and rock samples measured by the Alpha Particle X-ray Spectrometer (APXS) on the Mars Science Laboratory (MSL) rover Curiosity through sol 650. Multivariate approaches such as principal components analysis (PCA), cluster analysis, and factor analysis compliment more traditional approaches (e.g., Harker diagrams), with the advantage of simultaneously examining the relationships between multiple variables for large numbers of samples. Principal components analysis has been applied with success to APXS, Pancam, and Mössbauer data from the Mars Exploration Rovers. Factor analysis and cluster analysis have been applied with success to thermal infrared (TIR) spectral data of Mars. Cluster analyses group the input data by similarity, where there are a number of different methods for defining similarity (hierarchical, density, distribution, etc.). For example, without any assumptions about the chemical contributions of surface dust, preliminary hierarchical and K-means cluster analyses clearly distinguish the physically adjacent rock targets Windjana and Stephen as being distinctly different than lithologies observed prior to Curiosity's arrival at The Kimberley. In addition, they are separated from each other, consistent with chemical trends observed in variation diagrams but without requiring assumptions about chemical relationships. We will discuss the variation in cluster analysis results as a function of clustering method and pre-processing (e.g., log transformation, correction for dust cover) and implications for interpreting chemical data. Factor analysis shares some similarities with PCA, and examines the variability among observed components of a dataset so as to reveal variations attributable to unobserved components. Factor analysis has been used to extract the TIR spectra of components that are typically observed in mixtures and only rarely in isolation; there is the potential for similar results with data from APXS. These techniques offer new ways to understand the chemical relationships between the materials interrogated by Curiosity, and potentially their relation to materials observed by APXS instruments on other landed missions.

Analyses of soft tissue from Tyrannosaurus rex suggest the presence of protein.

PubMed

Schweitzer, Mary Higby; Suo, Zhiyong; Avci, Recep; Asara, John M; Allen, Mark A; Arce, Fernando Teran; Horner, John R

2007-04-13

We performed multiple analyses of Tyrannosaurus rex (specimen MOR 1125) fibrous cortical and medullary tissues remaining after demineralization. The results indicate that collagen I, the main organic component of bone, has been preserved in low concentrations in these tissues. The findings were independently confirmed by mass spectrometry. We propose a possible chemical pathway that may contribute to this preservation. The presence of endogenous protein in dinosaur bone may validate hypotheses about evolutionary relationships, rates, and patterns of molecular change and degradation, as well as the chemical stability of molecules over time.

Structurally Integrated Photoluminescent Chemical and Biological Sensors: An Organic Light-Emitting Diode-Based Platform

NASA Astrophysics Data System (ADS)

Shinar, J.; Shinar, R.

The chapter describes the development, advantages, challenges, and potential of an emerging, compact photoluminescence-based sensing platform for chemical and biological analytes, including multiple analytes. In this platform, the excitation source is an array of organic light-emitting device (OLED) pixels that is structurally integrated with the sensing component. Steps towards advanced integration with additionally a thin-film-based photodetector are also described. The performance of the OLED-based sensing platform is examined for gas-phase and dissolved oxygen, glucose, lactate, ethanol, hydrazine, and anthrax lethal factor.

Cavity-Enhanced Raman Spectroscopy for Food Chain Management

PubMed Central

Sandfort, Vincenz; Goldschmidt, Jens; Wöllenstein, Jürgen

2018-01-01

Comprehensive food chain management requires the monitoring of many parameters including temperature, humidity, and multiple gases. The latter is highly challenging because no low-cost technology for the simultaneous chemical analysis of multiple gaseous components currently exists. This contribution proposes the use of cavity enhanced Raman spectroscopy to enable online monitoring of all relevant components using a single laser source. A laboratory scale setup is presented and characterized in detail. Power enhancement of the pump light is achieved in an optical resonator with a Finesse exceeding 2500. A simulation for the light scattering behavior shows the influence of polarization on the spatial distribution of the Raman scattered light. The setup is also used to measure three relevant showcase gases to demonstrate the feasibility of the approach, including carbon dioxide, oxygen and ethene. PMID:29495501

Colloidally separated samples from Allende residues - Noble gases, carbon and an ESCA-study

NASA Technical Reports Server (NTRS)

Ott, U.; Kronenbitter, J.; Flores, J.; Chang, S.

1984-01-01

Results are presented which strengthen the hypothesis of heterogeneity among the carbon- and nitrogen-bearing phases of the Allende meteorite. These data also highlight the possibility of performing physical separations yielding samples in which some of the noble gas- and carbon-bearing phases are extraordinarily predominant over others. The conclusion, based on mass and isotope balance arguments, that a significant portion of the carbonaceous matter in Allende is likely to be gas-poor or gas-free need not weaken the case for carbonaceous carriers for the major noble gas components. The concept that acid-soluble carbonaceous phases contain a multiplicity of components, each of which may have formed under a multiplicity of different physical-chemical conditions, is reemphasized by the results of the present study.

Protein binding of isofluorophate in vivo after coexposure to multiple chemicals.

PubMed Central

Vogel, John S; Keating, Garrett A; Buchholz, Bruce A

2002-01-01

Full toxicologic profiles of chemical mixtures, including dose-response extrapolations to realistic exposures, is a prohibitive analytical problem, even for a restricted class of chemicals. We present an approach to probing in vivo interactions of pesticide mixtures at relevant low doses using a monitor compound to report the response of biochemical pathways shared by mixture components. We use accelerator mass spectrometry (AMS) to quantify [14C]-diisopropylfluorophosphate as a tracer at attomole levels with 1-5% precision after coexposures to parathion (PTN), permethrin (PER), and pyridostigmine bromide separately and in conjunction. Pyridostigmine shows an overall protective effect against tracer binding in plasma, red blood cells, muscle, and brain that is not explained as competitive protein binding. PTN and PER induce a significant 25-30% increase in the amount of tracer reaching the brain with or without pyridostigmine. The sensitivity of AMS for isotope-labeled tracer compounds can be used to probe the physiologic responses of specific biochemical pathways to multiple compound exposures. PMID:12634135

Advanced biological and chemical discovery (ABCD): centralizing discovery knowledge in an inherently decentralized world.

PubMed

Agrafiotis, Dimitris K; Alex, Simson; Dai, Heng; Derkinderen, An; Farnum, Michael; Gates, Peter; Izrailev, Sergei; Jaeger, Edward P; Konstant, Paul; Leung, Albert; Lobanov, Victor S; Marichal, Patrick; Martin, Douglas; Rassokhin, Dmitrii N; Shemanarev, Maxim; Skalkin, Andrew; Stong, John; Tabruyn, Tom; Vermeiren, Marleen; Wan, Jackson; Xu, Xiang Yang; Yao, Xiang

2007-01-01

We present ABCD, an integrated drug discovery informatics platform developed at Johnson & Johnson Pharmaceutical Research & Development, L.L.C. ABCD is an attempt to bridge multiple continents, data systems, and cultures using modern information technology and to provide scientists with tools that allow them to analyze multifactorial SAR and make informed, data-driven decisions. The system consists of three major components: (1) a data warehouse, which combines data from multiple chemical and pharmacological transactional databases, designed for supreme query performance; (2) a state-of-the-art application suite, which facilitates data upload, retrieval, mining, and reporting, and (3) a workspace, which facilitates collaboration and data sharing by allowing users to share queries, templates, results, and reports across project teams, campuses, and other organizational units. Chemical intelligence, performance, and analytical sophistication lie at the heart of the new system, which was developed entirely in-house. ABCD is used routinely by more than 1000 scientists around the world and is rapidly expanding into other functional areas within the J&J organization.

Pretreatment and integrated analysis of spectral data reveal seaweed similarities based on chemical diversity.

PubMed

Wei, Feifei; Ito, Kengo; Sakata, Kenji; Date, Yasuhiro; Kikuchi, Jun

2015-03-03

Extracting useful information from high dimensionality and large data sets is a major challenge for data-driven approaches. The present study was aimed at developing novel integrated analytical strategies for comprehensively characterizing seaweed similarities based on chemical diversity. The chemical compositions of 107 seaweed and 2 seagrass samples were analyzed using multiple techniques, including Fourier transform infrared (FT-IR) and solid- and solution-state nuclear magnetic resonance (NMR) spectroscopy, thermogravimetry-differential thermal analysis (TG-DTA), inductively coupled plasma-optical emission spectrometry (ICP-OES), CHNS/O total elemental analysis, and isotope ratio mass spectrometry (IR-MS). The spectral data were preprocessed using non-negative matrix factorization (NMF) and NMF combined with multivariate curve resolution-alternating least-squares (MCR-ALS) methods in order to separate individual component information from the overlapping and/or broad spectral peaks. Integrated analysis of the preprocessed chemical data demonstrated distinct discrimination of differential seaweed species. Further network analysis revealed a close correlation between the heavy metal elements and characteristic components of brown algae, such as cellulose, alginic acid, and sulfated mucopolysaccharides, providing a componential basis for its metal-sorbing potential. These results suggest that this integrated analytical strategy is useful for extracting and identifying the chemical characteristics of diverse seaweeds based on large chemical data sets, particularly complicated overlapping spectral data.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teplitsky, Ella; Joshi, Karan; Ericson, Daniel L.

We describe a high throughput method for screening up to 1728 distinct chemicals with protein crystals on a single microplate. Acoustic droplet ejection (ADE) was used to co-position 2.5 nL of protein, precipitant, and chemicals on a MiTeGen in situ-1 crystallization plate™ for screening by co-crystallization or soaking. ADE-transferred droplets follow a precise trajectory which allows all components to be transferred through small apertures in the microplate lid. The apertures were large enough for 2.5 nL droplets to pass through them, but small enough so that they did not disrupt the internal environment created by the mother liquor. Using thismore » system, thermolysin and trypsin crystals were efficiently screened for binding to a heavy-metal mini-library. Fluorescence and X-ray diffraction were used to confirm that each chemical in the heavy-metal library was correctly paired with the intended protein crystal. Moreover, a fragment mini-library was screened to observe two known lysozyme We describe a high throughput method for screening up to 1728 distinct chemicals with protein crystals on a single microplate. Acoustic droplet ejection (ADE) was used to co-position 2.5 nL of protein, precipitant, and chemicals on a MiTeGen in situ-1 crystallization plate™ for screening by co-crystallization or soaking. ADE-transferred droplets follow a precise trajectory which allows all components to be transferred through small apertures in the microplate lid. The apertures were large enough for 2.5 nL droplets to pass through them, but small enough so that they did not disrupt the internal environment created by the mother liquor. Using this system, thermolysin and trypsin crystals were efficiently screened for binding to a heavy-metal mini-library. Fluorescence and X-ray diffraction were used to confirm that each chemical in the heavy-metal library was correctly paired with the intended protein crystal. A fragment mini-library was screened to observe two known lysozyme ligands using both co-crystallization and soaking. A similar approach was used to identify multiple, novel thaumatin binding sites for ascorbic acid. This technology pushes towards a faster, automated, and more flexible strategy for high throughput screening of chemical libraries (such as fragment libraries) using as little as 2.5 nL of each component.ds using both co-crystallization and soaking. We used a A similar approach to identify multiple, novel thaumatin binding sites for ascorbic acid. This technology pushes towards a faster, automated, and more flexible strategy for high throughput screening of chemical libraries (such as fragment libraries) using as little as 2.5 nL of each component.« less

Active control of complex, multicomponent self-assembly processes

NASA Astrophysics Data System (ADS)

Schulman, Rebecca

The kinetics of many complex biological self-assembly processes such as cytoskeletal assembly are precisely controlled by cells. Spatiotemporal control over rates of filament nucleation, growth and disassembly determine how self-assembly occurs and how the assembled form changes over time. These reaction rates can be manipulated by changing the concentrations of the components needed for assembly by activating or deactivating them. I will describe how we can use these principles to design driven self-assembly processes in which we assemble and disassemble multiple types of components to create micron-scale networks of semiflexible filaments assembled from DNA. The same set of primitive components can be assembled into many different, structures depending on the concentrations of different components and how designed, DNA-based chemical reaction networks manipulate these concentrations over time. These chemical reaction networks can in turn interpret environmental stimuli to direct complex, multistage response. Such a system is a laboratory for understanding complex active material behaviors, such as metamorphosis, self-healing or adaptation to the environment that are ubiquitous in biological systems but difficult to quantitatively characterize or engineer.

Chemical analyses of fossil bone.

PubMed

Zheng, Wenxia; Schweitzer, Mary Higby

2012-01-01

The preservation of microstructures consistent with soft tissues, cells, and other biological components in demineralized fragments of dinosaur bone tens of millions of years old was unexpected, and counter to current hypotheses of tissue, cellular, and molecular degradation. Although the morphological similarity of these tissues to extant counterparts was unmistakable, after at least 80 million years exposed to geochemical influences, morphological similarity is insufficient to support an endogenous source. To test this hypothesis, and to characterize these materials at a molecular level, we applied multiple independent chemical, molecular, and microscopic analyses to identify the presence of original components produced by the extinct organisms. Microscopic techniques included field emission scanning electron microscopy, analytical transmission electron microscopy, transmitted light microscopy (LM), and fluorescence microscopy (FM). The chemical and molecular techniques include enzyme-linked immunosorbant assay, sodium dodecyl sulfate polyacrylamide gel electrophoresis, western blot (immunoblot), and attenuated total reflectance infrared spectroscopy. In situ analyses performed directly on tissues included immunohistochemistry and time-of-flight secondary ion mass spectrometry. The details of sample preparation and methodology are described in detail herein.

Discrimination of biological and chemical threat simulants in residue mixtures on multiple substrates.

PubMed

Gottfried, Jennifer L

2011-07-01

The potential of laser-induced breakdown spectroscopy (LIBS) to discriminate biological and chemical threat simulant residues prepared on multiple substrates and in the presence of interferents has been explored. The simulant samples tested include Bacillus atrophaeus spores, Escherichia coli, MS-2 bacteriophage, α-hemolysin from Staphylococcus aureus, 2-chloroethyl ethyl sulfide, and dimethyl methylphosphonate. The residue samples were prepared on polycarbonate, stainless steel and aluminum foil substrates by Battelle Eastern Science and Technology Center. LIBS spectra were collected by Battelle on a portable LIBS instrument developed by A3 Technologies. This paper presents the chemometric analysis of the LIBS spectra using partial least-squares discriminant analysis (PLS-DA). The performance of PLS-DA models developed based on the full LIBS spectra, and selected emission intensities and ratios have been compared. The full-spectra models generally provided better classification results based on the inclusion of substrate emission features; however, the intensity/ratio models were able to correctly identify more types of simulant residues in the presence of interferents. The fusion of the two types of PLS-DA models resulted in a significant improvement in classification performance for models built using multiple substrates. In addition to identifying the major components of residue mixtures, minor components such as growth media and solvents can be identified with an appropriately designed PLS-DA model.

Simultaneous and rapid determination of multiple component concentrations in a Kraft liquor process stream

DOEpatents

Li, Jian [Marietta, GA; Chai, Xin Sheng [Atlanta, GA; Zhu, Junyoung [Marietta, GA

2008-06-24

The present invention is a rapid method of determining the concentration of the major components in a chemical stream. The present invention is also a simple, low cost, device of determining the in-situ concentration of the major components in a chemical stream. In particular, the present invention provides a useful method for simultaneously determining the concentrations of sodium hydroxide, sodium sulfide and sodium carbonate in aqueous kraft pulping liquors through use of an attenuated total reflectance (ATR) tunnel flow cell or optical probe capable of producing a ultraviolet absorbency spectrum over a wavelength of 190 to 300 nm. In addition, the present invention eliminates the need for manual sampling and dilution previously required to generate analyzable samples. The inventive method can be used in Kraft pulping operations to control white liquor causticizing efficiency, sulfate reduction efficiency in green liquor, oxidation efficiency for oxidized white liquor and the active and effective alkali charge to kraft pulping operations.

Principal component analysis of chemical shift perturbation data of a multiple-ligand-binding system for elucidation of respective binding mechanism.

PubMed

Konuma, Tsuyoshi; Lee, Young-Ho; Goto, Yuji; Sakurai, Kazumasa

2013-01-01

Chemical shift perturbations (CSPs) in NMR spectra provide useful information about the interaction of a protein with its ligands. However, in a multiple-ligand-binding system, determining quantitative parameters such as a dissociation constant (K(d) ) is difficult. Here, we used a method we named CS-PCA, a principal component analysis (PCA) of chemical shift (CS) data, to analyze the interaction between bovine β-lactoglobulin (βLG) and 1-anilinonaphthalene-8-sulfonate (ANS), which is a multiple-ligand-binding system. The CSP on the binding of ANS involved contributions from two distinct binding sites. PCA of the titration data successfully separated the CSP pattern into contributions from each site. Docking simulations based on the separated CSP patterns provided the structures of βLG-ANS complexes for each binding site. In addition, we determined the K(d) values as 3.42 × 10⁻⁴ M² and 2.51 × 10⁻³ M for Sites 1 and 2, respectively. In contrast, it was difficult to obtain reliable K(d) values for respective sites from the isothermal titration calorimetry experiments. Two ANS molecules were found to bind at Site 1 simultaneously, suggesting that the binding occurs cooperatively with a partial unfolding of the βLG structure. On the other hand, the binding of ANS to Site 2 was a simple attachment without a significant conformational change. From the present results, CS-PCA was confirmed to provide not only the positions and the K(d) values of binding sites but also information about the binding mechanism. Thus, it is anticipated to be a general method to investigate protein-ligand interactions. Copyright © 2012 Wiley Periodicals, Inc.

Metal-organic framework catalysts for selective cleavage of aryl-ether bonds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allendorf, Mark D.; Stavila, Vitalie

The present invention relates to methods of employing a metal-organic framework (MOF) as a catalyst for cleaving chemical bonds. In particular instances, the MOF results in selective bond cleavage that results in hydrogenolyzis. Furthermore, the MOF catalyst can be reused in multiple cycles. Such MOF-based catalysts can be useful, e.g., to convert biomass components.

Phenotypic integration emerges from aposematism and scale in poison frogs

PubMed Central

Santos, Juan C.; Cannatella, David C.

2011-01-01

Complex phenotypes can be modeled as networks of component traits connected by genetic, developmental, or functional interactions. Aposematism, which has evolved multiple times in poison frogs (Dendrobatidae), links a warning signal to a chemical defense against predators. Other traits are involved in this complex phenotype. Most aposematic poison frogs are ant specialists, from which they sequester defensive alkaloids. We found that aposematic species have greater aerobic capacity, also related to diet specialization. To characterize the aposematic trait network more fully, we analyzed phylogenetic correlations among its hypothesized components: conspicuousness, chemical defense, diet specialization, body mass, active and resting metabolic rates, and aerobic scope. Conspicuous coloration was correlated with all components except resting metabolism. Structural equation modeling on the basis of trait correlations recovered “aposematism” as one of two latent variables in an integrated phenotypic network, the other being scaling with body mass and physiology (“scale”). Chemical defense and diet specialization were uniquely tied to aposematism whereas conspicuousness was related to scale. The phylogenetic distribution of the aposematic syndrome suggests two scenarios for its evolution: (i) chemical defense and conspicuousness preceded greater aerobic capacity, which supports the increased resource-gathering abilities required of ant–mite diet specialization; and (ii) assuming that prey are patchy, diet specialization and greater aerobic capacity evolved in tandem, and both traits subsequently facilitated the evolution of aposematism. PMID:21444790

[Preparation of panax notoginseng saponins-tanshinone H(A) composite method for pulmonary delivery with spray-drying method and its characterization].

PubMed

Wang, Hua-Mei; Fu, Ting-Ming; Guo, Li-Wei

2013-02-01

To prepare panax notoginseng saponins-tanshinone II(A) composite particles for pulmonary delivery, in order to explore a dry powder particle preparation method ensuring synchronized arrival of multiple components of traditional Chinese medicine compounds at absorption sites. Panax notoginseng saponins-tanshinone II(A) composite particles were prepared with spray-drying method, and characterized by scanning electron microscopy (SEM), confocal laser scanning microscope (CLSM), X-ray diffraction (XRD), infrared analysis (IR), dry laser particle size analysis, high performance liquid chromatography (HPLC) and the aerodynamic behavior was evaluated by a Next Generation Impactor (NGI). The dry powder particles produced had narrow particle size distribution range and good aerodynamic behavior, and could realize synchronized administration of multiple components. The spray-drying method is used to combine traditional Chinese medicine components with different physical and chemical properties in the same particle, and product into traditional Chinese medicine compound particles in line with the requirements for pulmonary delivery.

The controlled relay of multiple protons required at the active site of nitrogenase.

PubMed

Dance, Ian

2012-07-07

The enzyme nitrogenase, when reducing natural and unnatural substrates, requires large numbers of protons per chemical catalytic cycle. The active face of the catalytic site (the FeMo-cofactor, FeMo-co) is situated in a protein domain which is largely hydrophobic and anhydrous, and incapable of serial provision of multiple protons. Through detailed analysis of the high quality protein crystal structures available the characteristics of a chain of water molecules leading from the protein surface to a key sulfur atom (S3B) of FeMo-co are described. The first half of the water chain from the surface inwards is branched, slightly variable, and able to accommodate exogenous small molecules: this is dubbed the proton bay. The second half, from the proton bay to S3B, is comprised of a single chain of eight hydrogen bonded water molecules. This section is strictly conserved, and is intimately involved in hydrogen bonds with homocitrate, an essential component that chelates Mo. This is the proton wire, and a detailed Grotthuss mechanism for serial translocation of protons through this proton wire to S3B is proposed. This controlled serial proton relay from the protein surface to S3B is an essential component of the intramolecular hydrogenation paradigm for the complete chemical mechanisms of nitrogenase. Each proton reaching S3B, instigated by electron transfer to FeMo-co, becomes a hydrogen atom that migrates to other components of the active face of FeMo-co and to bound substrates and intermediates, allowing subsequent multiple proton transfers along the proton wire. Experiments to test the proposed mechanism of proton supply are suggested. The water chain in nitrogenase is comparable with the purported proton pumping pathway of cytochrome c oxidase.

The motivation, skills, and decision-making model of "drug abuse" prevention.

PubMed

Sussman, Steve; Earleywine, Mitchell; Wills, Thomas; Cody, Christine; Biglan, Tony; Dent, Clyde W; Newcomb, Michael D

2004-01-01

This article summarizes the theoretical basis for targeted prevention programs as they apply to different high-risk groups. We explain the advantages and disadvantages of different definitions of risk and discuss strategies for preventing drug use related problems in high-risk youth. Productive prevention programs for many at-risk groups share similar components, including those that address motivation, skills, and decision making. We present key aspects of these three components and link them to theories in clinical psychology, social psychology, sociology, and chemical dependence treatment. Among a total of 29 promising targeted prevention programs, we describe examples of empirically evaluated, intensive interventions that have made a positive impact on the attitudes and behavior of multiple problem youth. Incorporating the perspectives of multiple disciplines appears essential for progress in drug abuse and other problem behavior prevention.

Simultaneous assimilation of satellite NO2, O3, CO, and HNO3 data for the analysis of the tropospheric chemical composition

NASA Astrophysics Data System (ADS)

Miyazaki, K.; Eskes, H.; Sudo, K.

2012-04-01

Carbon monoxide (CO) and nitrogen oxides (NOx) play an important role in tropospheric chemistry through their influences on the ozone and hydroxyl radical (OH). The simultaneous optimization of various chemical components is expected to improve the emission inversion through the better description of the chemical feedbacks in the NOx- and CO-chemistry. This study aims to reproduce chemical composition distributions in the troposphere by combining information obtained from multiple satellite data sets. The emissions of CO and NOx, together with the 3D concentration fields of all forecasted chemical species in the global CTM CHASER have been simultaneously optimized using the ensemble Kalman filter (EnKF) data assimilation technique, and NO2, O3, CO, and HNO3 data obtained from OMI, TES, MOPITT, and MLS satellite measurements. The performance is evaluated against independent data from ozone sondes, aircraft measurements, GOME-2, and SCIAMACHY satellite data. Observing System Experiments (OSEs) have been carried out. These OSEs quantify the relative importance of each data set on constraining the emissions and concentrations. We confirmed that the simultaneous data assimilation improved the agreement with these independent data sets. The combined analysis of multiple data sets by means of advanced data assimilation system can provide a useful framework for the air quality research.

Nanoscale chemical imaging by photoinduced force microscopy

PubMed Central

Nowak, Derek; Morrison, William; Wickramasinghe, H. Kumar; Jahng, Junghoon; Potma, Eric; Wan, Lei; Ruiz, Ricardo; Albrecht, Thomas R.; Schmidt, Kristin; Frommer, Jane; Sanders, Daniel P.; Park, Sung

2016-01-01

Correlating spatial chemical information with the morphology of closely packed nanostructures remains a challenge for the scientific community. For example, supramolecular self-assembly, which provides a powerful and low-cost way to create nanoscale patterns and engineered nanostructures, is not easily interrogated in real space via existing nondestructive techniques based on optics or electrons. A novel scanning probe technique called infrared photoinduced force microscopy (IR PiFM) directly measures the photoinduced polarizability of the sample in the near field by detecting the time-integrated force between the tip and the sample. By imaging at multiple IR wavelengths corresponding to absorption peaks of different chemical species, PiFM has demonstrated the ability to spatially map nm-scale patterns of the individual chemical components of two different types of self-assembled block copolymer films. With chemical-specific nanometer-scale imaging, PiFM provides a powerful new analytical method for deepening our understanding of nanomaterials. PMID:27051870

Linking stressors and ecological responses

USGS Publications Warehouse

Gentile, J.H.; Solomon, K.R.; Butcher, J.B.; Harrass, M.; Landis, W.G.; Power, M.; Rattner, B.A.; Warren-Hicks, W.J.; Wenger, R.; Foran, Jeffery A.; Ferenc, Susan A.

1999-01-01

To characterize risk, it is necessary to quantify the linkages and interactions between chemical, physical and biological stressors and endpoints in the conceptual framework for ecological risk assessment (ERA). This can present challenges in a multiple stressor analysis, and it will not always be possible to develop a quantitative stressor-response profile. This review commences with a conceptual representation of the problem of developing a linkage analysis for multiple stressors and responses. The remainder of the review surveys a variety of mathematical and statistical methods (e.g., ranking methods, matrix models, multivariate dose-response for mixtures, indices, visualization, simulation modeling and decision-oriented methods) for accomplishing the linkage analysis for multiple stressors. Describing the relationships between multiple stressors and ecological effects are critical components of 'effects assessment' in the ecological risk assessment framework.

Chemical compounds from anthropogenic environment and immune evasion mechanisms: potential interactions

PubMed Central

Kravchenko, Julia; Corsini, Emanuela; Williams, Marc A.; Decker, William; Manjili, Masoud H.; Otsuki, Takemi; Singh, Neetu; Al-Mulla, Faha; Al-Temaimi, Rabeah; Amedei, Amedeo; Colacci, Anna Maria; Vaccari, Monica; Mondello, Chiara; Scovassi, A. Ivana; Raju, Jayadev; Hamid, Roslida A.; Memeo, Lorenzo; Forte, Stefano; Roy, Rabindra; Woodrick, Jordan; Salem, Hosni K.; Ryan, Elizabeth P.; Brown, Dustin G.; Lowe, Leroy; Lyerly, H.Kim

2015-01-01

An increasing number of studies suggest an important role of host immunity as a barrier to tumor formation and progression. Complex mechanisms and multiple pathways are involved in evading innate and adaptive immune responses, with a broad spectrum of chemicals displaying the potential to adversely influence immunosurveillance. The evaluation of the cumulative effects of low-dose exposures from the occupational and natural environment, especially if multiple chemicals target the same gene(s) or pathway(s), is a challenge. We reviewed common environmental chemicals and discussed their potential effects on immunosurveillance. Our overarching objective was to review related signaling pathways influencing immune surveillance such as the pathways involving PI3K/Akt, chemokines, TGF-β, FAK, IGF-1, HIF-1α, IL-6, IL-1α, CTLA-4 and PD-1/PDL-1 could individually or collectively impact immunosurveillance. A number of chemicals that are common in the anthropogenic environment such as fungicides (maneb, fluoxastrobin and pyroclostrobin), herbicides (atrazine), insecticides (pyridaben and azamethiphos), the components of personal care products (triclosan and bisphenol A) and diethylhexylphthalate with pathways critical to tumor immunosurveillance. At this time, these chemicals are not recognized as human carcinogens; however, it is known that they these chemicalscan simultaneously persist in the environment and appear to have some potential interfere with the host immune response, therefore potentially contributing to promotion interacting with of immune evasion mechanisms, and promoting subsequent tumor growth and progression. PMID:26002081

Experimental investigations of mechanical and reaction responses for drop-weight impacted energetic particles

NASA Astrophysics Data System (ADS)

Bao, Xiao-Wei; Wu, Yan-Qing; Wang, Ming-Yang; Huang, Feng-Lei

2017-02-01

Low-velocity drop-weight impact experiments on individual and multiple Cyclotetramethylene tetranitramine (HMX) energetic particles were performed using a modified drop-weight machine equipped with high-speed photography components. Multiple particles experienced more severe burning reactions than an individual particle. Comparisons between impacted salt and HMX particle show that jetting in HMX is mainly due to the motion of fragmented particles driven by gaseous reaction products. Velocity of jetting, flame propagation, and area expansion were measured via image processing, making it possible to quantify the chemical reaction or mechanical deformation violence at different stages.

Multidimensional bioseparation with modular microfluidics

DOEpatents

Chirica, Gabriela S.; Renzi, Ronald F.

2013-08-27

A multidimensional chemical separation and analysis system is described including a prototyping platform and modular microfluidic components capable of rapid and convenient assembly, alteration and disassembly of numerous candidate separation systems. Partial or total computer control of the separation system is possible. Single or multiple alternative processing trains can be tested, optimized and/or run in parallel. Examples related to the separation and analysis of human bodily fluids are given.

Shallow groundwater quality and associated non-cancer health risk in agricultural areas (Poyang Lake basin, China).

PubMed

Soldatova, Evgeniya; Sun, Zhanxue; Maier, Sofya; Drebot, Valeriia; Gao, Bai

2018-03-24

Owing to their accessibility, shallow groundwater is an essential source of drinking water in rural areas while usually being used without control by authorities. At the same time, this type of water resource is one of the most vulnerable to pollution, especially in regions with extensive agricultural activity. These factors increase the probability of adverse health effects in the population as a result of the consumption of shallow groundwater. In the present research, shallow groundwater quality in the agricultural areas of Poyang Lake basin was assessed according to world and national standards for drinking water quality. To evaluate non-cancer health risk from drinking groundwater, the hazard quotient from exposure to individual chemicals and hazard index from exposure to multiple chemicals were applied. It was found that, in shallow groundwater, the concentrations of 11 components (NO 3 - , NH 4 + , Fe, Mn, As, Al, rare NO 2 - , Se, Hg, Tl and Pb) exceed the limits referenced in the standards for drinking water. According to the health risk assessment, only five components (NO 3 - , Fe, As, rare NO 2 - and Mn) likely provoke non-cancer effects. The attempt to evaluate the spatial distribution of human health risk from exposure to multiple chemicals shows that the most vulnerable area is associated with territory characterised by low altitude where reducing or near-neutral conditions are formed (lower reaches of Xiushui and Ganjiang Rivers). The largest health risk is associated with the immune system and adverse dermal effects.

Identification and analysis of chemical constituents and rat serum metabolites in Suan-Zao-Ren granule using ultra high performance liquid chromatography quadrupole time-of-flight mass spectrometry combined with multiple data processing approaches.

PubMed

Du, Yiyang; He, Bosai; Li, Qing; He, Jiao; Wang, Di; Bi, Kaishun

2017-07-01

Suan-Zao-Ren granule is widely used to treat insomnia in China. However, because of the complexity and diversity of the chemical compositions in traditional Chinese medicine formula, the comprehensive analysis of constituents in vitro and in vivo is rather difficult. In our study, an ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry and the PeakView® software, which uses multiple data processing approaches including product ion filter, neutral loss filter, and mass defect filter, method was developed to characterize the ingredients and rat serum metabolites in Suan-Zao-Ren granule. A total of 101 constituents were detected in vitro. Under the same analysis conditions, 68 constituents were characterized in rat serum, including 35 prototype components and 33 metabolites. The metabolic pathways of main components were also illustrated. Among them, the metabolic pathways of timosaponin AI were firstly revealed. The bioactive compounds mainly underwent the phase I metabolic pathways including hydroxylation, oxidation, hydrolysis, and phase II metabolic pathways including sulfate conjugation, glucuronide conjugation, cysteine conjugation, acetycysteine conjugation, and glutathione conjugation. In conclusion, our results showed that this analysis approach was extremely useful for the in-depth pharmacological research of Suan-Zao-Ren granule and provided a chemical basis for its rational. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reproductive and developmental toxicity of the components of gasoline.

PubMed Central

Skalko, R G

1993-01-01

The reproductive, developmental, and postnatal toxicity of 14 select chemicals and mixtures that are components of gasoline has been reviewed. The majority of experimental analyses have been performed as either variations of the accepted segment 2 protocol or as traditional teratology studies. Specific deficiencies in the present database have been identified and are most obvious in the evaluation of reproductive and postnatal effects. It is recommended that future studies address the continuing need for assessment in multiple species and over a range of dosages with specific emphasis on the impact of route of administration on the results obtained. PMID:8020438

In-Space Chemical Propulsion System Model

NASA Technical Reports Server (NTRS)

Byers, David C.; Woodcock, Gordon; Benfield, Michael P. J.

2004-01-01

Multiple, new technologies for chemical systems are becoming available and include high temperature rockets, very light propellant tanks and structures, new bipropellant and monopropellant options, lower mass propellant control components, and zero boil off subsystems. Such technologies offer promise of increasing the performance of in-space chemical propulsion for energetic space missions. A mass model for pressure-fed, Earth and space-storable, advanced chemical propulsion systems (ACPS) was developed in support of the NASA MSFC In-Space Propulsion Program. Data from flight systems and studies defined baseline system architectures and subsystems and analyses were formulated for parametric scaling relationships for all ACPS subsystem. The paper will first provide summary descriptions of the approaches used for the systems and the subsystems and then present selected analyses to illustrate use of the model for missions with characteristics of current interest.

In-Space Chemical Propulsion System Model

NASA Technical Reports Server (NTRS)

Byers, David C.; Woodcock, Gordon; Benfield, M. P. J.

2004-01-01

Multiple, new technologies for chemical systems are becoming available and include high temperature rockets, very light propellant tanks and structures, new bipropellant and monopropellant options, lower mass propellant control components, and zero boil off subsystems. Such technologies offer promise of increasing the performance of in-space chemical propulsion for energetic space missions. A mass model for pressure-fed, Earth and space-storable, advanced chemical propulsion systems (ACPS) was developed in support of the NASA MSFC In-Space Propulsion Program. Data from flight systems and studies defined baseline system architectures and subsystems and analyses were formulated for parametric scaling relationships for all ACPS subsystems. The paper will first provide summary descriptions of the approaches used for the systems and the subsystems and then present selected analyses to illustrate use of the model for missions with characteristics of current interest.

Cumulative Risk Assessment: An Overview of Methodological Approaches for Evaluating Combined Health Effects from Exposure to Multiple Environmental Stressors

PubMed Central

Sexton, Ken

2012-01-01

Systematic evaluation of cumulative health risks from the combined effects of multiple environmental stressors is becoming a vital component of risk-based decisions aimed at protecting human populations and communities. This article briefly examines the historical development of cumulative risk assessment as an analytical tool, and discusses current approaches for evaluating cumulative health effects from exposure to both chemical mixtures and combinations of chemical and nonchemical stressors. A comparison of stressor-based and effects-based assessment methods is presented, and the potential value of focusing on viable risk management options to limit the scope of cumulative evaluations is discussed. The ultimate goal of cumulative risk assessment is to provide answers to decision-relevant questions based on organized scientific analysis; even if the answers, at least for the time being, are inexact and uncertain. PMID:22470298

Glomerular Activity Patterns Evoked by Natural Odor Objects in the Rat Olfactory Bulb Are Related to Patterns Evoked by Major Odorant Components

PubMed Central

Johnson, Brett A.; Ong, Joan; Leon, Michael

2014-01-01

To determine how responses evoked by natural odorant mixtures compare to responses evoked by individual odorant chemicals, we mapped 2-deoxyglucose uptake during exposures to vapors arising from a variety of odor objects that may be important to rodents in the wild. We studied 21 distinct natural odor stimuli ranging from possible food sources such as fruits, vegetables, and meats to environmental odor objects such as grass, herbs, and tree leaves. The natural odor objects evoked robust and surprisingly focal patterns of 2-deoxyglucose uptake involving clusters of neighboring glomeruli, thereby resembling patterns evoked by pure chemicals. Overall, the patterns were significantly related to patterns evoked by monomolecular odorant components that had been studied previously. Object patterns also were significantly related to the molecular features present in the mixture components. Despite these overall relationships, there were individual examples of object patterns that were simpler than might have been predicted given the multiplicity of components present in the vapors. In these cases, the object patterns lacked certain responses evoked by their major odorant mixture components. These data suggest the possibility of mixture response interactions and provide a foundation for understanding the neural coding of natural odor stimuli. PMID:20187145

Single Aerosol Particle Studies Using Optical Trapping Raman And Cavity Ringdown Spectroscopy

NASA Astrophysics Data System (ADS)

Gong, Z.; Wang, C.; Pan, Y. L.; Videen, G.

2017-12-01

Due to the physical and chemical complexity of aerosol particles and the interdisciplinary nature of aerosol science that involves physics, chemistry, and biology, our knowledge of aerosol particles is rather incomplete; our current understanding of aerosol particles is limited by averaged (over size, composition, shape, and orientation) and/or ensemble (over time, size, and multi-particles) measurements. Physically, single aerosol particles are the fundamental units of any large aerosol ensembles. Chemically, single aerosol particles carry individual chemical components (properties and constituents) in particle ensemble processes. Therefore, the study of single aerosol particles can bridge the gap between aerosol ensembles and bulk/surface properties and provide a hierarchical progression from a simple benchmark single-component system to a mixed-phase multicomponent system. A single aerosol particle can be an effective reactor to study heterogeneous surface chemistry in multiple phases. Latest technological advances provide exciting new opportunities to study single aerosol particles and to further develop single aerosol particle instrumentation. We present updates on our recent studies of single aerosol particles optically trapped in air using the optical-trapping Raman and cavity ringdown spectroscopy.

Filter-based chemical sensors for hazardous materials

NASA Astrophysics Data System (ADS)

Major, Kevin J.; Ewing, Kenneth J.; Poutous, Menelaos K.; Sanghera, Jasbinder S.; Aggarwal, Ishwar D.

2014-05-01

The development of new techniques for the detection of homemade explosive devices is an area of intense research for the defense community. Such sensors must exhibit high selectivity to detect explosives and/or explosives related materials in a complex environment. Spectroscopic techniques such as FTIR are capable of discriminating between the volatile components of explosives; however, there is a need for less expensive systems for wide-range use in the field. To tackle this challenge we are investigating the use of multiple, overlapping, broad-band infrared (IR) filters to enable discrimination of volatile chemicals associated with an explosive device from potential background interferants with similar chemical signatures. We present an optical approach for the detection of fuel oil (the volatile component in ammonium nitrate-fuel oil explosives) that relies on IR absorption spectroscopy in a laboratory environment. Our proposed system utilizes a three filter set to separate the IR signals from fuel oil and various background interferants in the sample headspace. Filter responses for the chemical spectra are calculated using a Gaussian filter set. We demonstrate that using a specifically chosen filter set enables discrimination of pure fuel oil, hexanes, and acetone, as well as various mixtures of these components. We examine the effects of varying carrier gasses and humidity on the collected spectra and corresponding filter response. We study the filter response on these mixtures over time as well as present a variety of methods for observing the filter response functions to determine the response of this approach to detecting fuel oil in various environments.

Is the difference between chemical and numerical estimates of baseflow meaningful?

NASA Astrophysics Data System (ADS)

Cartwright, Ian; Gilfedder, Ben; Hofmann, Harald

2014-05-01

Both chemical and numerical techniques are commonly used to calculate baseflow inputs to gaining rivers. In general the chemical methods yield lower estimates of baseflow than the numerical techniques. In part, this may be due to the techniques assuming two components (event water and baseflow) whereas there may also be multiple transient stores of water. Bank return waters, interflow, or waters stored on floodplains are delayed components that may be geochemically similar to the surface water from which they are derived; numerical techniques may record these components as baseflow whereas chemical mass balance studies are likely to aggregate them with the surface water component. This study compares baseflow estimates using chemical mass balance, local minimum methods, and recursive digital filters in the upper reaches of the Barwon River, southeast Australia. While more sophisticated techniques exist, these methods of estimating baseflow are readily applied with the available data and have been used widely elsewhere. During the early stages of high-discharge events, chemical mass balance overestimates groundwater inflows, probably due to flushing of saline water from wetlands and marshes, soils, or the unsaturated zone. Overall, however, estimates of baseflow from the local minimum and recursive digital filters are higher than those from chemical mass balance using Cl calculated from continuous electrical conductivity. Between 2001 and 2011, the baseflow contribution to the upper Barwon River calculated using chemical mass balance is between 12 and 25% of annual discharge. Recursive digital filters predict higher baseflow contributions of 19 to 52% of annual discharge. These estimates are similar to those from the local minimum method (16 to 45% of annual discharge). These differences most probably reflect how the different techniques characterise the transient water sources in this catchment. The local minimum and recursive digital filters aggregate much of the water from delayed sources as baseflow. However, as many of these delayed transient water stores (such as bank return flow, floodplain storage, or interflow) have Cl concentrations that are similar to surface runoff, chemical mass balance calculations aggregate them with the surface runoff component. The difference between the estimates is greatest following periods of high discharge in winter, implying that these transient stores of water feed the river for several weeks to months at that time. Cl vs. discharge variations during individual flow events also demonstrate that inflows of high-salinity older water occurs on the rising limbs of hydrographs followed by inflows of low-salinity water from the transient stores as discharge falls. The use of complementary techniques allows a better understanding of the different components of water that contribute to river flow, which is important for the management and protection of water resources.

The polysaccharide and low molecular weight components of Opuntia ficus indica cladodes: Structure and skin repairing properties.

PubMed

Di Lorenzo, Flaviana; Silipo, Alba; Molinaro, Antonio; Parrilli, Michelangelo; Schiraldi, Chiara; D'Agostino, Antonella; Izzo, Elisabetta; Rizza, Luisa; Bonina, Andrea; Bonina, Francesco; Lanzetta, Rosa

2017-02-10

The Opuntia ficus-indica multiple properties are reflected in the increasing interest of chemists in the identification of its natural components having pharmaceutical and/or cosmetical applications. Here we report the structural elucidation of Opuntia ficus-indica mucilage that highlighted the presence of components differing for their chemical nature and the molecular weight distribution. The high molecular weight components were identified as a linear galactan polymer and a highly branched xyloarabinan. The low molecular weight components were identified as lactic acid, D-mannitol, piscidic, eucomic and 2-hydroxy-4-(4'-hydroxyphenyl)-butanoic acids. A wound healing assay was performed in order to test the cicatrizing properties of the various components, highlighting the ability of these latter to fasten dermal regeneration using a simplified in vitro cellular model based on a scratched keratinocytes monolayer. The results showed that the whole Opuntia mucilage and the low molecular weight components are active in the wound repair. Copyright © 2016 Elsevier Ltd. All rights reserved.

Graphene Nanoplatelet-Polymer Chemiresistive Sensor Arrays for the Detection and Discrimination of Chemical Warfare Agent Simulants.

PubMed

Wiederoder, Michael S; Nallon, Eric C; Weiss, Matt; McGraw, Shannon K; Schnee, Vincent P; Bright, Collin J; Polcha, Michael P; Paffenroth, Randy; Uzarski, Joshua R

2017-11-22

A cross-reactive array of semiselective chemiresistive sensors made of polymer-graphene nanoplatelet (GNP) composite coated electrodes was examined for detection and discrimination of chemical warfare agents (CWA). The arrays employ a set of chemically diverse polymers to generate a unique response signature for multiple CWA simulants and background interferents. The developed sensors' signal remains consistent after repeated exposures to multiple analytes for up to 5 days with a similar signal magnitude across different replicate sensors with the same polymer-GNP coating. An array of 12 sensors each coated with a different polymer-GNP mixture was exposed 100 times to a cycle of single analyte vapors consisting of 5 chemically similar CWA simulants and 8 common background interferents. The collected data was vector normalized to reduce concentration dependency, z-scored to account for baseline drift and signal-to-noise ratio, and Kalman filtered to reduce noise. The processed data was dimensionally reduced with principal component analysis and analyzed with four different machine learning algorithms to evaluate discrimination capabilities. For 5 similarly structured CWA simulants alone 100% classification accuracy was achieved. For all analytes tested 99% classification accuracy was achieved demonstrating the CWA discrimination capabilities of the developed system. The novel sensor fabrication methods and data processing techniques are attractive for development of sensor platforms for discrimination of CWA and other classes of chemical vapors.

Identification and Quantification of Cumulative Factors that ...

EPA Pesticide Factsheets

Evaluating the combined adverse effects of multiple stressors upon human health is an imperative component of cumulative risk assessment (CRA)1. In addition to chemical stressors, other non-chemical factors are also considered. For examples, smoking will elevate the risks of having lung cancer associated with radon exposure2; toluene and noise together will induce higher levels of hearing loss3; children exposed to violence will have higher risks of developing asthma in the presence of air pollution4. Environmental Justice (EJ) indicators, used as a tool to assess and quantify some of these non-chemical factors, include health, economic, and social indicators such as vulnerability and susceptibility5. Vulnerability factors encompass race, ethnicity, behavior, geographic location, etc., while susceptibility factors include life stage, genetic predisposition, pre-existing health condition and others6, although these two categories are not always mutually exclusive. Numerous findings regarding combined effects of EJ indicators and chemical stressors have been identified7-11. However, fewer studies have analyzed the interrelation between multiple stressors that exert combined harmful effects upon individual or population health in the context of exposure assessment within the risk assessment framework12. In this study, we connected EJ indicators to variables in the exposure assessment model, especially the Average Daily Dose (ADD) model13, in order to better underst

A Magic-Angle Spinning NMR Method for the Site-Specific Measurement of Proton Chemical-Shift Anisotropy in Biological and Organic Solids.

PubMed

Hou, Guangjin; Gupta, Rupal; Polenova, Tatyana; Vega, Alexander J

2014-02-01

Proton chemical shifts are a rich probe of structure and hydrogen bonding environments in organic and biological molecules. Until recently, measurements of 1 H chemical shift tensors have been restricted to either solid systems with sparse proton sites or were based on the indirect determination of anisotropic tensor components from cross-relaxation and liquid-crystal experiments. We have introduced an MAS approach that permits site-resolved determination of CSA tensors of protons forming chemical bonds with labeled spin-1/2 nuclei in fully protonated solids with multiple sites, including organic molecules and proteins. This approach, originally introduced for the measurements of chemical shift tensors of amide protons, is based on three RN -symmetry based experiments, from which the principal components of the 1 H CS tensor can be reliably extracted by simultaneous triple fit of the data. In this article, we expand our approach to a much more challenging system involving aliphatic and aromatic protons. We start with a review of the prior work on experimental-NMR and computational-quantum-chemical approaches for the measurements of 1 H chemical shift tensors and for relating these to the electronic structures. We then present our experimental results on U- 13 C, 15 N-labeled histdine demonstrating that 1 H chemical shift tensors can be reliably determined for the 1 H 15 N and 1 H 13 C spin pairs in cationic and neutral forms of histidine. Finally, we demonstrate that the experimental 1 H(C) and 1 H(N) chemical shift tensors are in agreement with Density Functional Theory calculations, therefore establishing the usefulness of our method for characterization of structure and hydrogen bonding environment in organic and biological solids.

Chemical mixtures in untreated water from public-supply wells in the U.S. — Occurrence, composition, and potential toxicity

USGS Publications Warehouse

Toccalino, Patricia L.; Norman, Julia E.; Scott, Jonathon C.

2012-01-01

Chemical mixtures are prevalent in groundwater used for public water supply, but little is known about their potential health effects. As part of a large-scale ambient groundwater study, we evaluated chemical mixtures across multiple chemical classes, and included more chemical contaminants than in previous studies of mixtures in public-supply wells. We (1) assessed the occurrence of chemical mixtures in untreated source-water samples from public-supply wells, (2) determined the composition of the most frequently occurring mixtures, and (3) characterized the potential toxicity of mixtures using a new screening approach. The U.S. Geological Survey collected one untreated water sample from each of 383 public wells distributed across 35 states, and analyzed the samples for as many as 91 chemical contaminants. Concentrations of mixture components were compared to individual human-health benchmarks; the potential toxicity of mixtures was characterized by addition of benchmark-normalized component concentrations. Most samples (84%) contained mixtures of two or more contaminants, each at concentrations greater than one-tenth of individual benchmarks. The chemical mixtures that most frequently occurred and had the greatest potential toxicity primarily were composed of trace elements (including arsenic, strontium, or uranium), radon, or nitrate. Herbicides, disinfection by-products, and solvents were the most common organic contaminants in mixtures. The sum of benchmark-normalized concentrations was greater than 1 for 58% of samples, suggesting that there could be potential for mixtures toxicity in more than half of the public-well samples. Our findings can be used to help set priorities for groundwater monitoring and suggest future research directions for drinking-water treatment studies and for toxicity assessments of chemical mixtures in water resources.

[Studies on chemical components of essential oil of crude semen sinapis and roasted semen sinapis].

PubMed

Chen, Mi-Yu; Lin, Yan-Ni; Wu, Guo-Xin; Wu, Cui-Ping

2006-07-01

To study the chemical components of the essential oil of the Semen Sinapis with the different processing methods. The essential oils of the crude Semen Sinapis and the roasted Semen Sinapis were extracted by steam distillation. The chemical components were analyzed by means of GC-MS-DS. The relative content of each component was calculated by area normalization. The main chemical components of the essential oil of the crude Semen Sinapis and the roasted Semen Sinapis were similar. The main chemical components were allyl isothiocyanate and 4-isothio-cyanato-1-butene. The chemical components of the essential oil of the crude Semen Sinapis were more than that of the roasted Semen Sinapis. The effect of different processing methods on the chemical components of the essential oil of Semen Sinapis was significant. Certain chemical components such as isothiocyanato-containing substances, were found in the crude Semen Sinapis.

Future water quality monitoring--adapting tools to deal with mixtures of pollutants in water resource management.

PubMed

Altenburger, Rolf; Ait-Aissa, Selim; Antczak, Philipp; Backhaus, Thomas; Barceló, Damià; Seiler, Thomas-Benjamin; Brion, Francois; Busch, Wibke; Chipman, Kevin; de Alda, Miren López; de Aragão Umbuzeiro, Gisela; Escher, Beate I; Falciani, Francesco; Faust, Michael; Focks, Andreas; Hilscherova, Klara; Hollender, Juliane; Hollert, Henner; Jäger, Felix; Jahnke, Annika; Kortenkamp, Andreas; Krauss, Martin; Lemkine, Gregory F; Munthe, John; Neumann, Steffen; Schymanski, Emma L; Scrimshaw, Mark; Segner, Helmut; Slobodnik, Jaroslav; Smedes, Foppe; Kughathas, Subramaniam; Teodorovic, Ivana; Tindall, Andrew J; Tollefsen, Knut Erik; Walz, Karl-Heinz; Williams, Tim D; Van den Brink, Paul J; van Gils, Jos; Vrana, Branislav; Zhang, Xiaowei; Brack, Werner

2015-04-15

Environmental quality monitoring of water resources is challenged with providing the basis for safeguarding the environment against adverse biological effects of anthropogenic chemical contamination from diffuse and point sources. While current regulatory efforts focus on monitoring and assessing a few legacy chemicals, many more anthropogenic chemicals can be detected simultaneously in our aquatic resources. However, exposure to chemical mixtures does not necessarily translate into adverse biological effects nor clearly shows whether mitigation measures are needed. Thus, the question which mixtures are present and which have associated combined effects becomes central for defining adequate monitoring and assessment strategies. Here we describe the vision of the international, EU-funded project SOLUTIONS, where three routes are explored to link the occurrence of chemical mixtures at specific sites to the assessment of adverse biological combination effects. First of all, multi-residue target and non-target screening techniques covering a broader range of anticipated chemicals co-occurring in the environment are being developed. By improving sensitivity and detection limits for known bioactive compounds of concern, new analytical chemistry data for multiple components can be obtained and used to characterise priority mixtures. This information on chemical occurrence will be used to predict mixture toxicity and to derive combined effect estimates suitable for advancing environmental quality standards. Secondly, bioanalytical tools will be explored to provide aggregate bioactivity measures integrating all components that produce common (adverse) outcomes even for mixtures of varying compositions. The ambition is to provide comprehensive arrays of effect-based tools and trait-based field observations that link multiple chemical exposures to various environmental protection goals more directly and to provide improved in situ observations for impact assessment of mixtures. Thirdly, effect-directed analysis (EDA) will be applied to identify major drivers of mixture toxicity. Refinements of EDA include the use of statistical approaches with monitoring information for guidance of experimental EDA studies. These three approaches will be explored using case studies at the Danube and Rhine river basins as well as rivers of the Iberian Peninsula. The synthesis of findings will be organised to provide guidance for future solution-oriented environmental monitoring and explore more systematic ways to assess mixture exposures and combination effects in future water quality monitoring. Copyright © 2015 Elsevier B.V. All rights reserved.

Solid source MOCVD system

DOEpatents

Hubert, Brian N.; Wu, Xin Di

1998-01-01

A system for MOCVD fabrication of superconducting and non-superconducting oxide films provides a delivery system for the feeding of metalorganic precursors for multi-component chemical vapor deposition. The delivery system can include multiple cartridges containing tightly packed precursor materials. The contents of each cartridge can be ground at a desired rate and fed together with precursor materials from other cartridges to a vaporization zone and then to a reaction zone within a deposition chamber for thin film deposition.

Isolation, characterization, and biological properties of an endotoxin-like material from the gram-positive organism Listeria monocytogenes.

PubMed

Wexler, H; Oppenheim, J D

1979-03-01

The bacterial component responsible for the induction of transient cold agglutinin syndrome in rabbits after intravenous injection of heat-killed Listeria monocytogenes type 4B has been purified and biologically and chemically characterized. A purified immunoglobulin M cold agglutinin was prepared from high-titer sera resulting from the immunization of rabbits with heat-killed L. monocytogenes type 4B and was subsequently used to monitor the purification of the bacterial component responsible for its induction. The bacterial component was isolated from a hot phenol-water extract of lyophilized L. monocytogenes type 4B by multiple molecular sieve chromatography. Upon chemical analysis the purified material was found to be strikingly similar in chemical composition to gram-negative lipopolysaccharide endotoxins. The material contained 15% total fatty acid (of which 50% was beta-hydroxymyristic acid), 40 to 45% neutral sugar (glucose, galactose, and rhamnose), 11.5% amino sugar, 12% uronic acid, 2.5% 2-keto-3-deoxyoctonic acid, 2% heptose, 0.87% phosphorus, and 1.6% amino acid, thereby accounting for 85 to 90% of the weight of the component. Electron micrographs of the purified material were similar to those of lipopolysaccharide preparations from gram-negative organisms. The purified material exist in aqueous solutions as large aggregates, but can be dissociated into a single smaller subunit (3.1S) by dialysis against sodium dodecyl sulfate buffer. The listerial component was toxic and pyrogenic to rabbits, producing symptoms typical of gram-negative endotoxins. Activity in the limulus lysate gelation assay and in the carbocyanine dye assay provides a further link of this material with classical gram-negative endotoxins.

Multiple optimization of chemical components and texture of purple maize expanded by IVDV treatment using the response surface methodology.

PubMed

Mrad, Rachelle; Debs, Espérance; Maroun, Richard G; Louka, Nicolas

2014-12-15

A new process, Intensification of Vaporization by Decompression to the Vacuum (IVDV), is proposed for texturizing purple maize. It consists in exposing humid kernels to high steam pressure followed by a decompression to the vacuum. Response surface methodology with three operating parameters (initial water content (W), steam pressure (P) and processing time (T)) was used to study the response parameters: Total Anthocyanins Content, Total Polyphenols Content, Free Radical Scavenging Activity, Expansion Ratio, Hardness and Work Done. P was the most important variable, followed by T. Pressure drop helped the release of bound phenolics arriving to their expulsion outside the cell. Combined with convenient T and W, it caused kernels expansion. Multiple optimization of expansion and chemical content showed that IVDV resulted in good texturization of maize while preserving the antioxidant compounds and activity. Optimal conditions were: W=29%, P=5 bar and T=37s. Copyright © 2014 Elsevier Ltd. All rights reserved.

Diagenesis and evolution of microporosity of Middle-Upper Devonian Kee Scarp reefs, Norman Wells, Northwest Territories, Canada: Petrographic and chemical evidence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Aasm, I.S.; Azmy, K.K.

The Middle-Upper Devonian Kee Scarp reef complexes of Norman Wells, Northwest Territories, Canada, are oil-producing, stromatoporoid-dominated carbonates. Episodic increases in the rate of sea level rise produced multiple cycles of reef growth that exhibit backstepping characteristics. These carbonates, composed of invariably altered limestones, have original interskeletal, intraskeletal, and intergranular porosity, mostly occluded by nonferroan, dull luminescent cements. Secondary porosity, represented by micropores of various types, developed during diagenesis by aggrading neomorphism and dissolution. The micropores represent the main reservoir porosity in the Kee Scarp limestone. Petrographic, chemical, and isotopic studies of Kee Scarp reef components reveal a complex diagenetic historymore » involving marine fluids modified by increasing water/rock interaction and burial. Neomorphic stabilization of skeletal components caused further depletion in {gamma}{sup 18}O but very little change in {gamma}{sup 13}C, an argument for modification of the original marine fluids with increasing burial. Variations in magnitude of water/rock interaction with depth, facies changes, and porosity modifications probably exerted some control on fractionation and distribution of stable isotopes and trace elements in reef components.« less

Chemical compounds from anthropogenic environment and immune evasion mechanisms: potential interactions.

PubMed

Kravchenko, Julia; Corsini, Emanuela; Williams, Marc A; Decker, William; Manjili, Masoud H; Otsuki, Takemi; Singh, Neetu; Al-Mulla, Faha; Al-Temaimi, Rabeah; Amedei, Amedeo; Colacci, Anna Maria; Vaccari, Monica; Mondello, Chiara; Scovassi, A Ivana; Raju, Jayadev; Hamid, Roslida A; Memeo, Lorenzo; Forte, Stefano; Roy, Rabindra; Woodrick, Jordan; Salem, Hosni K; Ryan, Elizabeth P; Brown, Dustin G; Bisson, William H; Lowe, Leroy; Lyerly, H Kim

2015-06-01

An increasing number of studies suggest an important role of host immunity as a barrier to tumor formation and progression. Complex mechanisms and multiple pathways are involved in evading innate and adaptive immune responses, with a broad spectrum of chemicals displaying the potential to adversely influence immunosurveillance. The evaluation of the cumulative effects of low-dose exposures from the occupational and natural environment, especially if multiple chemicals target the same gene(s) or pathway(s), is a challenge. We reviewed common environmental chemicals and discussed their potential effects on immunosurveillance. Our overarching objective was to review related signaling pathways influencing immune surveillance such as the pathways involving PI3K/Akt, chemokines, TGF-β, FAK, IGF-1, HIF-1α, IL-6, IL-1α, CTLA-4 and PD-1/PDL-1 could individually or collectively impact immunosurveillance. A number of chemicals that are common in the anthropogenic environment such as fungicides (maneb, fluoxastrobin and pyroclostrobin), herbicides (atrazine), insecticides (pyridaben and azamethiphos), the components of personal care products (triclosan and bisphenol A) and diethylhexylphthalate with pathways critical to tumor immunosurveillance. At this time, these chemicals are not recognized as human carcinogens; however, it is known that they these chemicalscan simultaneously persist in the environment and appear to have some potential interfere with the host immune response, therefore potentially contributing to promotion interacting with of immune evasion mechanisms, and promoting subsequent tumor growth and progression. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Solid source MOCVD system

DOEpatents

Hubert, B.N.; Wu, X.D.

1998-10-13

A system for MOCVD fabrication of superconducting and non-superconducting oxide films provides a delivery system for the feeding of metallorganic precursors for multi-component chemical vapor deposition. The delivery system can include multiple cartridges containing tightly packed precursor materials. The contents of each cartridge can be ground at a desired rate and fed together with precursor materials from other cartridges to a vaporization zone and then to a reaction zone within a deposition chamber for thin film deposition. 13 figs.

Translation system engineering in Escherichia coli enhances non-canonical amino acid incorporation into proteins.

PubMed

Gan, Rui; Perez, Jessica G; Carlson, Erik D; Ntai, Ioanna; Isaacs, Farren J; Kelleher, Neil L; Jewett, Michael C

2017-05-01

The ability to site-specifically incorporate non-canonical amino acids (ncAAs) into proteins has made possible the study of protein structure and function in fundamentally new ways, as well as the bio synthesis of unnatural polymers. However, the task of site-specifically incorporating multiple ncAAs into proteins with high purity and yield continues to present a challenge. At the heart of this challenge lies the lower efficiency of engineered orthogonal translation system components compared to their natural counterparts (e.g., translation elements that specifically use a ncAA and do not interact with the cell's natural translation apparatus). Here, we show that evolving and tuning expression levels of multiple components of an engineered translation system together as a whole enhances ncAA incorporation efficiency. Specifically, we increase protein yield when incorporating multiple p-azido-phenylalanine(pAzF) residues into proteins by (i) evolving the Methanocaldococcus jannaschii p-azido-phenylalanyl-tRNA synthetase anti-codon binding domain, (ii) evolving the elongation factor Tu amino acid-binding pocket, and (iii) tuning the expression of evolved translation machinery components in a single vector. Use of the evolved translation machinery in a genomically recoded organism lacking release factor one enabled enhanced multi-site ncAA incorporation into proteins. We anticipate that our approach to orthogonal translation system development will accelerate and expand our ability to site-specifically incorporate multiple ncAAs into proteins and biopolymers, advancing new horizons for synthetic and chemical biotechnology. Biotechnol. Bioeng. 2017;114: 1074-1086. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Determination of five flavonoids in different parts of Fordia cauliflora by ultra performance liquid chromatography/triple-quadrupole mass spectrometry and chemical comparison with the root of Millettia pulchra var. laxior

PubMed Central

2013-01-01

Background The root of Fordia cauliflora Hemsl (FC) has long been used in southern China for the treatment of rheumatism, bruises, dementia in children, and valetudinarianism. However, sometimes it is mixed with other parts. And it has always been confused with the root of Millettia pulchra (Benth.) Kurz var. laxior (Dunn) Z. Wei (MP) by the local people. The chemical differences between the two ethnic drugs are not clear until now. The aim of this study is to develop a precise and accurate method to characterize and quantify multiple chemical components of FC, which is helpful for the quality evaluation and identification of FC. Results A method coupling ultra performance liquid chromatography (UPLC) with triple-quadrupole mass spectrometry (QqQ-MS) was first developed for simultaneous determination of five flavonoids in different parts of FC and the root of MP, based on a UPLC-diode array detection (DAD) fingerprint method. All calibration curves showed good linearity (R2>0.99) within test ranges. The overall LOD and LOQ were lower than 2.5 ng/mL and 5.0 ng/mL, respectively. The RSDs for intra- and inter-day of five analytes were less than 2.83% and 3.04%, respectively. Recovery studies for the quantified compounds were found to be within the range 93.6-99.8% with RSD less than 5.73%. The results suggest that the root, traditionally used medicinal part, yields the highest flavanoid content in FC. Pachycarin A, 3′,4′-dimethoxy(2′′,3′′:7,8) furanoflavone, karanjachromene and isoderricin A can be used to differentiate between FC and MP samples. Conclusions The present method is specific, precise and reliable, and is suitable for characterizing and quantifying multiple chemical components of FC. PMID:23870070

Effect of superoxidized water and sodium hypochlorite, associated or not with EDTA, on organic and inorganic components of bovine root dentin.

PubMed

Ghisi, Alexandre Corrêa; Kopper, Patrícia Maria Poli; Baldasso, Flávia E R; Stürmer, Caroline P; Rossi-Fedele, Giampiero; Steier, Liviu; de Figueiredo, José Antonio Poli; Morgental, Renata Dornelles; Vier-Pelisser, Fabiana Vieira

2015-06-01

This study aimed to evaluate the effects of Sterilox (Sx), a superoxidized water, 5% and 2% sodium hypochlorite (5NaOCl and 2NaOCl), and 17% EDTA (E) on the organic and inorganic components of bovine dentin. Eighty bovine incisors were randomly divided into 8 groups (n = 10): 5NaOCl, 5NaOCl + E, 2NaOCl, 2NaOCl + E, Sx, Sx + E, E alone, and distilled water (H2O). Root canal instrumentation was performed by using the corresponding irrigant. The apical 15 mm was longitudinally sectioned into 2 fragments, one for light microscopy analysis in slides stained with picrosirius red (organic component) and the other for scanning electron microscopy analysis (inorganic component). Scores data obtained in the light microscopy analysis were submitted to the Kruskal-Wallis test, followed by multiple comparisons test (P < .05). Scanning electron microscopy images were analyzed descriptively. The chemical solution 5NaOCl had a greater effect on the organic component of dentin in area and depth than 2NaOCl. The chemical solutions 5NaOCl + E, 5NaOCl and 2NaOCl + E caused the greatest change in the collagenous organic matrix near the root canal lumen. The chemical solution 2NaOCl showed similar behavior to Sx, associated or not with E, promoting more superficial disorganization of collagen in a smaller area. Demineralization was observed in all groups in which E was used. However, areas of erosion and open dentinal tubules were detected only when it was combined with NaOCl. Five percent NaOCl promoted the most extensive damage to the organic component of dentin, and when associated to EDTA, dentinal erosion could be seen. Considering these specific aspects, 2% NaOCl and Sx had milder effects on bovine root dentin. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Recent advances in heterocycle generation using the efficient Ugi multiple-component condensation reaction.

PubMed

Tempest, Paul A

2005-11-01

The current trend of rising research spending and falling numbers of novel chemical entities continues to drive efforts aimed at increasing efficiency in the drug discovery process. Strategic issues, such as assigning resources to poorly validated targets have been implicated in the declining productivity of recent years. Tactical approaches employed to improve this situation include attempts to speed the discovery process toward decision points in a timely manner. Accelerating the optimization of high-throughput screening hits is a goal in streamlining the discovery process, and the use of multiple-component condensation (MCC) reactions have proved useful toward this end. MCC reactions are powerful and efficient tools for the generation of diverse compound sets. Collections of compounds can be synthesized with all of the required diversity elements included in a single synthetic step. One of the most widely investigated MCC reactions is the Ugi four-component condensation. This review highlights disclosures of the Ugi reaction published over the past two years (2003 to 2005) in three areas: (i) Ugi reaction in conjunction with post-condensation cyclization; (ii) bifunctional condensations leading to heterocyclic cores; and (iii) general findings relating to linear products or interesting improvements in the basic Ugi reaction.

42 CFR 84.191 - Chemical cartridge respirators; required components.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Chemical cartridge respirators; required components... Chemical Cartridge Respirators § 84.191 Chemical cartridge respirators; required components. (a) Each chemical cartridge respirator described in § 84.190 shall, where its design requires, contain the following...

42 CFR 84.191 - Chemical cartridge respirators; required components.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Chemical cartridge respirators; required components... Chemical Cartridge Respirators § 84.191 Chemical cartridge respirators; required components. (a) Each chemical cartridge respirator described in § 84.190 shall, where its design requires, contain the following...

42 CFR 84.191 - Chemical cartridge respirators; required components.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 1 2013-10-01 2013-10-01 false Chemical cartridge respirators; required components... Chemical Cartridge Respirators § 84.191 Chemical cartridge respirators; required components. (a) Each chemical cartridge respirator described in § 84.190 shall, where its design requires, contain the following...

42 CFR 84.191 - Chemical cartridge respirators; required components.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 1 2014-10-01 2014-10-01 false Chemical cartridge respirators; required components... Chemical Cartridge Respirators § 84.191 Chemical cartridge respirators; required components. (a) Each chemical cartridge respirator described in § 84.190 shall, where its design requires, contain the following...

42 CFR 84.191 - Chemical cartridge respirators; required components.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 1 2012-10-01 2012-10-01 false Chemical cartridge respirators; required components... Chemical Cartridge Respirators § 84.191 Chemical cartridge respirators; required components. (a) Each chemical cartridge respirator described in § 84.190 shall, where its design requires, contain the following...

Programmable chemical controllers made from DNA.

PubMed

Chen, Yuan-Jyue; Dalchau, Neil; Srinivas, Niranjan; Phillips, Andrew; Cardelli, Luca; Soloveichik, David; Seelig, Georg

2013-10-01

Biological organisms use complex molecular networks to navigate their environment and regulate their internal state. The development of synthetic systems with similar capabilities could lead to applications such as smart therapeutics or fabrication methods based on self-organization. To achieve this, molecular control circuits need to be engineered to perform integrated sensing, computation and actuation. Here we report a DNA-based technology for implementing the computational core of such controllers. We use the formalism of chemical reaction networks as a 'programming language' and our DNA architecture can, in principle, implement any behaviour that can be mathematically expressed as such. Unlike logic circuits, our formulation naturally allows complex signal processing of intrinsically analogue biological and chemical inputs. Controller components can be derived from biologically synthesized (plasmid) DNA, which reduces errors associated with chemically synthesized DNA. We implement several building-block reaction types and then combine them into a network that realizes, at the molecular level, an algorithm used in distributed control systems for achieving consensus between multiple agents.

Programmable chemical controllers made from DNA

NASA Astrophysics Data System (ADS)

Chen, Yuan-Jyue; Dalchau, Neil; Srinivas, Niranjan; Phillips, Andrew; Cardelli, Luca; Soloveichik, David; Seelig, Georg

2013-10-01

Biological organisms use complex molecular networks to navigate their environment and regulate their internal state. The development of synthetic systems with similar capabilities could lead to applications such as smart therapeutics or fabrication methods based on self-organization. To achieve this, molecular control circuits need to be engineered to perform integrated sensing, computation and actuation. Here we report a DNA-based technology for implementing the computational core of such controllers. We use the formalism of chemical reaction networks as a 'programming language' and our DNA architecture can, in principle, implement any behaviour that can be mathematically expressed as such. Unlike logic circuits, our formulation naturally allows complex signal processing of intrinsically analogue biological and chemical inputs. Controller components can be derived from biologically synthesized (plasmid) DNA, which reduces errors associated with chemically synthesized DNA. We implement several building-block reaction types and then combine them into a network that realizes, at the molecular level, an algorithm used in distributed control systems for achieving consensus between multiple agents.

Programmable chemical controllers made from DNA

PubMed Central

Chen, Yuan-Jyue; Dalchau, Neil; Srinivas, Niranjan; Phillips, Andrew; Cardelli, Luca; Soloveichik, David; Seelig, Georg

2014-01-01

Biological organisms use complex molecular networks to navigate their environment and regulate their internal state. The development of synthetic systems with similar capabilities could lead to applications such as smart therapeutics or fabrication methods based on self-organization. To achieve this, molecular control circuits need to be engineered to perform integrated sensing, computation and actuation. Here we report a DNA-based technology for implementing the computational core of such controllers. We use the formalism of chemical reaction networks as a 'programming language', and our DNA architecture can, in principle, implement any behaviour that can be mathematically expressed as such. Unlike logic circuits, our formulation naturally allows complex signal processing of intrinsically analogue biological and chemical inputs. Controller components can be derived from biologically synthesized (plasmid) DNA, which reduces errors associated with chemically synthesized DNA. We implement several building-block reaction types and then combine them into a network that realizes, at the molecular level, an algorithm used in distributed control systems for achieving consensus between multiple agents. PMID:24077029

Spectroscopic Analysis of Temporal Changes in Leaf Moisture and Dry Matter Content

NASA Astrophysics Data System (ADS)

Qi, Y.; Dennison, P. E.; Brewer, S.; Jolly, W. M.; Kropp, R.

2013-12-01

Live fuel moisture (LFM), the ratio of water content to dry matter content (DMC) in live fuel, is critical for determining fire danger and behavior. Remote sensing estimation of LFM often relies on an assumption of changing water content and stable DMC over time. In order to advance understanding of temporal variation in LFM and DMC, we collected field samples and spectroscopic data for two species, lodgepole pine (Pinus contorta) and big sagebrush (Artemisia tridentata), to explore seasonal trends and spectral expression of these trends. New and old needles were measured separately for lodgepole pine. All samples were measured using a visible/NIR/SWIR spectrometer, and coincident samples were processed to provide LFM, DMC, water content and chemical components including structural and non-structural carbohydrates. New needles initially exhibited higher LFM and a smaller proportion of DMC, but differences between new and old needles converged as the new needles hardened. DMC explained more variation in LFM than water content for new pine needles and sagebrush leaves. Old pine needles transported non-structural carbohydrates to new needles to accumulate DMC during the growth season, resulting decreasing LFM in new needles. DMC and water content co-varied with vegetation chemical components and physical structure. Spectral variation in response to changing DMC is difficulty to isolate from the spectral signatures of multiple chemical components. Partial least square regression combined with hyperspectral data may increase modeling performance in LFM estimation.

Evidence for partial overlap of male olfactory cues in lampreys

USGS Publications Warehouse

Buchinger, Tyler J.; Li, Ke; Huertas, Mar; Baker, Cindy F.; Jia, Liang; Hayes, Michael C.; Li, Weiming; Johnson, Nicholas S.

2016-01-01

Animals rely on a mosaic of complex information to find and evaluate mates. Pheromones, often comprised of multiple components, are considered to be particularly important for species-recognition in many species. While the evolution of species-specific pheromone blends is well-described in many insects, very few vertebrate pheromones have been studied in a macro-evolutionary context. Here, we report a phylogenetic comparison of multi-component male odours that guide reproduction in lampreys. Chemical profiling of sexually mature males from eleven species of lamprey, representing six of ten genera and two of three families, indicated the chemical profiles of sexually mature male odours are partially shared among species. Behavioural assays conducted with four species sympatric in the Laurentian Great Lakes indicated asymmetric female responses to heterospecific odours, where Petromyzon marinus were attracted to male odour collected from all species tested but other species generally preferred only the odour of conspecifics. Electro-olfactogram recordings from P. marinusindicated that although P. marinus exhibited behavioural responses to odours from males of all species, at least some of the compounds that elicited olfactory responses were different in conspecific male odours compared to heterospecific male odours. We conclude that some of the compounds released by sexually mature males are shared among species and elicit olfactory and behavioural responses in P. marinus, and suggest that our results provide evidence for partial overlap of male olfactory cues among lampreys. Further characterization of the chemical identities of odour components is needed to confirm shared pheromones among species.

Factors contributing to the immunogenicity of meningococcal conjugate vaccines

PubMed Central

Bröker, Michael; Berti, Francesco; Costantino, Paolo

2016-01-01

ABSTRACT Various glycoprotein conjugate vaccines have been developed for the prevention of invasive meningococcal disease, having significant advantages over pure polysaccharide vaccines. One of the most important features of the conjugate vaccines is the induction of a T-cell dependent immune response, which enables both the induction of immune memory and a booster response after repeated immunization. The nature of the carrier protein to which the polysaccharides are chemically linked, is often regarded as the main component of the vaccine in determining its immunogenicity. However, other factors can have a significant impact on the vaccine's profile. In this review, we explore the physico-chemical properties of meningococcal conjugate vaccines, which can significantly contribute to the vaccine's immunogenicity. We demonstrate that the carrier is not the sole determining factor of the vaccine's profile, but, moreover, that the conjugate vaccine's immunogenicity is the result of multiple physico-chemical structures and characteristics. PMID:26934310

Direct chemical profiling of olive (Olea europaea) fruit epicuticular waxes by direct electrospray-ultrahigh resolution mass spectrometry.

PubMed

Vichi, Stefania; Cortés-Francisco, Nuria; Romero, Agustí; Caixach, Josep

2015-03-01

In the present paper, an electrospray ionization (ESI)-Orbitrap method is proposed for the direct chemical profiling of epicuticular wax (EW) from Olea europaea fruit. It constitutes a rapid and efficient tool suitable for a wide-ranging screening of a large number of samples. In a few minutes, the method provides a comprehensive characterization of total EW extracts, based on the molecular formula of their components. Accurate mass measurements are obtained by ultrahigh resolution mass spectrometry, and compositional restrictions are set on the basis of the information available from previous studies of olive EW. By alternating positive and negative ESI modes within the same analysis, complementary results are obtained and a wide range of chemical species is covered. This provides a detailed compositional overview that otherwise would only be available by applying multiple analytical techniques. Copyright © 2015 John Wiley & Sons, Ltd.

Synergistic activation of human pregnane X receptor by binary cocktails of pharmaceutical and environmental compounds.

PubMed

Delfosse, Vanessa; Dendele, Béatrice; Huet, Tiphaine; Grimaldi, Marina; Boulahtouf, Abdelhay; Gerbal-Chaloin, Sabine; Beucher, Bertrand; Roecklin, Dominique; Muller, Christina; Rahmani, Roger; Cavaillès, Vincent; Daujat-Chavanieu, Martine; Vivat, Valérie; Pascussi, Jean-Marc; Balaguer, Patrick; Bourguet, William

2015-09-03

Humans are chronically exposed to multiple exogenous substances, including environmental pollutants, drugs and dietary components. Many of these compounds are suspected to impact human health, and their combination in complex mixtures could exacerbate their harmful effects. Here we demonstrate that a pharmaceutical oestrogen and a persistent organochlorine pesticide, both exhibiting low efficacy when studied separately, cooperatively bind to the pregnane X receptor, leading to synergistic activation. Biophysical analysis shows that each ligand enhances the binding affinity of the other, so the binary mixture induces a substantial biological response at doses at which each chemical individually is inactive. High-resolution crystal structures reveal the structural basis for the observed cooperativity. Our results suggest that the formation of 'supramolecular ligands' within the ligand-binding pocket of nuclear receptors contributes to the synergistic toxic effect of chemical mixtures, which may have broad implications for the fields of endocrine disruption, toxicology and chemical risk assessment.

Chemical Composition Measurements of LAWA44 Glass Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fox, K.; Edwards, T.; Riley, W.

2016-11-15

DOE is building the Hanford Tank Waste Treatment and Immobilization Plant (WTP) at the Hanford Site in Washington to remediate 55 million gallons of radioactive waste that is temporarily stored in 177 underground tanks. Both low-activity and high-level wastes will then be vitrified into borosilicate glass using Joule-heated ceramic melters. Efforts are being made to increase the loading of Hanford tank wastes in the glass. One area of work is enhancing waste glass composition/property models and broadening the compositional regions over which those models are applicable. In this report, the Savannah River National Laboratory provides chemical analysis results for severalmore » samples of a simulated low-activity waste glass, LAWA44, provided by the Pacific Northwest National Laboratory as part of an ongoing development task. The measured chemical composition data are reported and compared with the targeted values for each component for each glass. A detailed review showed no indications of errors in the preparation or measurement of the study glasses. All of the measured sums of oxides for the study glasses fell within the interval of 97.9 to 102.6 wt %, indicating acceptable recovery of the glass components. Comparisons of the targeted and measured chemical compositions showed that the measured values for the glasses met the targeted concentrations within 10% for those components present at more than 5 wt %. It was noted that the measured B 2O 3 concentrations are somewhat above the targeted values for the study glasses. No obvious trends were observed with regard to the multiple melting steps used to prepare the study glasses, indicating that any potential effects of volatility were below measurable thresholds.« less

Identification of the chemical components of Saussurea involucrata by high-resolution mass spectrometry and the mass spectral trees similarity filter technique.

PubMed

Jia, Zhixin; Wu, Caisheng; Jin, Hongtao; Zhang, Jinlan

2014-11-15

Saussurea involucrata is a rare traditional Chinese medicine (TCM) that displays anti-fatigue, anti-inflammatory and anti-tumor effects. In this paper, the different chemical components of Saussurea involucrata were characterized and identified over a wide dynamic range by high-performance liquid chromatography coupled with high-resolution hybrid mass spectrometry (HPLC/HRMS/MS(n)) and the mass spectral trees similarity filter (MTSF) technique. The aerial parts of Saussurea involucrata were extracted with 75% ethanol. The partial extract was separated on a chromatography column to concentrate the low-concentration compounds. Mass data were acquired using full-scan mass analysis (resolving power 50,000) with data-dependent incorporation of dynamic exclusion analysis. The identified compounds were used as templates to construct a database of mass spectral trees. Data for the unknown compounds were matched with those templates and matching candidate structures were obtained. The detected compounds were characterized based on matching to candidate structures by the MTSF technique and were further identified by their accurate mass weight, multiple-stage analysis and fragmentation patterns and through comparison with literature data. A total of 38 compounds were identified including 19 flavones, 11 phenylpropanoids and 8 sphingolipids. Among them, 7 flavonoids, 8 phenylpropanoids and 8 sphingolipids were identified for the first time in Saussurea involucrata. HPLC/HRMS/MS(n) combined with MTSF was successfully used to discover and identify the chemical compounds in Saussurea involucrata. The results indicated that this combined technique was extremely useful for the rapid detection and identification of the chemical components in TCMs. Copyright © 2014 John Wiley & Sons, Ltd.

Decoupling thermal, chemical, and mechanical strain components in thin films

NASA Astrophysics Data System (ADS)

Silberstein, Meredith; Crumlin, Ethan; Shao-Horn, Yang; Boyce, Mary

2011-03-01

Many electrochemical systems have performance which is affected by internal strains due to thermal and/or chemical stimuli. The bi-material curvature method is a means to quantify these thermal and chemical strains and their coupling with mechanical stress. In this method, a thin layer of the material of interest is deposited on a substrate of intermediate thickness. The composite assumes a curvature that depends on the mismatch strains between the substrate and film. The Stoney formula provides an explicit expression for the film stress as a function of the elastic substrate properties, film and substrate thickness, and curvature. Here we study two distinct materials systems: Nafion used as the polymer electrolyte in low temperature fuel cells, and epitaxial perovskite thin films used as a catalyst for the oxygen reduction reaction in solid oxide fuel cells. The thermal, chemical, and mechanical strains are quantitatively determined as functions of temperature and atmospheric conditions by monitoring the curvature evolution with changes in these parameters. The extent of coupling of the thermal and chemical strains with mechanical stress is evaluated by conducting the experiment at multiple substrate thicknesses.

Metabolic engineering with plants for a sustainable biobased economy.

PubMed

Yoon, Jong Moon; Zhao, Le; Shanks, Jacqueline V

2013-01-01

Plants are bona fide sustainable organisms because they accumulate carbon and synthesize beneficial metabolites from photosynthesis. To meet the challenges to food security and health threatened by increasing population growth and depletion of nonrenewable natural resources, recent metabolic engineering efforts have shifted from single pathways to holistic approaches with multiple genes owing to integration of omics technologies. Successful engineering of plants results in the high yield of biomass components for primary food sources and biofuel feedstocks, pharmaceuticals, and platform chemicals through synthetic biology and systems biology strategies. Further discovery of undefined biosynthesis pathways in plants, integrative analysis of discrete omics data, and diversified process developments for production of platform chemicals are essential to overcome the hurdles for sustainable production of value-added biomolecules from plants.

An alternative approach to combination vaccines: intradermal administration of isolated components for control of anthrax, botulism, plague and staphylococcal toxic shock

PubMed Central

Morefield, Garry L; Tammariello, Ralph F; Purcell, Bret K; Worsham, Patricia L; Chapman, Jennifer; Smith, Leonard A; Alarcon, Jason B; Mikszta, John A; Ulrich, Robert G

2008-01-01

Background Combination vaccines reduce the total number of injections required for each component administered separately and generally provide the same level of disease protection. Yet, physical, chemical, and biological interactions between vaccine components are often detrimental to vaccine safety or efficacy. Methods As a possible alternative to combination vaccines, we used specially designed microneedles to inject rhesus macaques with four separate recombinant protein vaccines for anthrax, botulism, plague and staphylococcal toxic shock next to each other just below the surface of the skin, thus avoiding potentially incompatible vaccine mixtures. Results The intradermally-administered vaccines retained potent antibody responses and were well- tolerated by rhesus macaques. Based on tracking of the adjuvant, the vaccines were transported from the dermis to draining lymph nodes by antigen-presenting cells. Vaccinated primates were completely protected from an otherwise lethal aerosol challenge by Bacillus anthracis spores, botulinum neurotoxin A, or staphylococcal enterotoxin B. Conclusion Our results demonstrated that the physical separation of vaccines both in the syringe and at the site of administration did not adversely affect the biological activity of each component. The vaccination method we describe may be scalable to include a greater number of antigens, while avoiding the physical and chemical incompatibilities encountered by combining multiple vaccines together in one product. PMID:18768085

Preliminary paleomagnetic and rock magnetic results from 17 to 22 ka sediment of Jeju Island, Korea: Geomagnetic excursional behavior or rock magnetic anomalies?

NASA Astrophysics Data System (ADS)

Ahn, Hyeon-Seon; Sohn, Young Kwan; Lee, Jin-Young; Kim, Jin Cheul

2018-05-01

Paleomagnetic and rock magnetic investigations were performed on a 64-cm-thick section of nonmarine unconsolidated muddy sediment from the Gosan Formation on Jeju Island, Korea. This sediment was recently dated to have been deposited between 22 and 17 kyr BP calibrated, with a sedimentation rate of 13-25 cm/kyr, based on many radiocarbon ages. Interestingly, stepwise alternating field (AF) demagnetization revealed characteristic natural remanent magnetizations with anomalous directions, manifested by marked deviations from the direction of today's axial dipole field, for some separate depth levels. On the other hand, stepwise thermal (TH) demagnetization showed more complex behavior, resulting in the identification of multiple remanence components. For all TH-treated specimens, consistently two different components are predominant: a low-temperature component unblocked below 240-320 °C entirely having normal-polarity apparently within the secular variation range of the Brunhes Chron, and a high-temperature component with unblocking temperatures (Tubs) between 240-320 and 520-580 °C that have anomalous directions, concentrated in the 13-34-cm-depth interval ( 17-19 ka in inferred age) and possibly below 53 cm depth (before 20 ka). Rock magnetic results also infer the dominance of low-coercivity magnetic particles having 300 and 580 °C Curie temperature as remanence carriers, suggestive of (titano)maghemite and/or Ti-rich titanomagnetite and magnetite (or Ti-poor titanomagnetite), respectively. A noteworthy finding is that AF demagnetizations in this study often lead to incomplete separation of the two remanence components possibly due to their strongly overlapping AF spectra. The unusual directions do not appear to result from self-reversal remanences. Then, one interpretation is that the low-temperature components are attributable to post-depositional chemical remanences, associated possibly with the later formation of the mineral phase having Tub 300 °C, whereas the high-temperature components are of primary detrital origin that survived later chemical influence. Accordingly, the unusual directions might record geomagnetic instability within the 17-22 ka period manifested by multiple excursional swings, partly associated with the Tianchi/Hilina Pali excursion. However, further work is needed to verify this interpretation and distinguish it from alternative explanations that invoke rock magnetic complexities as the cause of the unusual directions.[Figure not available: see fulltext.

In vivo ultrasound and biometric measurements predict the empty body chemical composition in Nellore cattle.

PubMed

Castilhos, A M; Francisco, C L; Branco, R H; Bonilha, S F M; Mercadante, M E Z; Meirelles, P R L; Pariz, C M; Jorge, A M

2018-05-04

Evaluation of the body chemical composition of beef cattle can only be measured postmortem and those data cannot be used in real production scenarios to adjust nutritional plans. The objective of this study was to develop multiple linear regression equations from in vivo measurements, such as ultrasound parameters [backfat thickness (uBFT, mm), rump fat thickness (uRF, mm), and ribeye area (uLMA, cm2)], shrunk body weight (SBW, kg), age (AG, d), hip height (HH, m), as well as from postmortem measurements (composition of the 9th to 11th rib section) to predict the empty body and carcass chemical composition for Nellore cattle. Thirty-three young bulls were used (339 ± 36.15 kg and 448 ± 17.78 d for initial weight and age, respectively). Empty body chemical composition (protein, fat, water, and ash in kg) was obtained by combining noncarcass and carcass components. Data were analyzed using the PROC REG procedure of SAS software. Mallows' Cp values were close to the ideal value of number of independent variables in the prediction equations plus one. Equations to predict chemical components of both empty body and carcass using in vivo measurements presented higher R2 values than those determined by postmortem measurements. Chemical composition of the empty body using in vivo measurements was predicted with R2 > 0.73. Equations to predict chemical composition of the carcass from in vivo measurements showed R2 lower (R2< 0.68) than observed for empty body, except for the water (R2 = 0.84). The independent variables SBW, uRF, and AG were sufficient to predict the fat, water, energy components of the empty body, whereas for estimation of protein content the uRF, HH, and SBW were satisfactory. For the calculation of the ash, the SBW variable in the equation was sufficient. Chemical compounds from components of the empty body of Nellore cattle can be calculated by the following equations: protein (kg) = 47.92 + 0.18 × SBW - 1.46 × uRF - 30.72 × HH (R2 = 0.94, RMSPE = 1.79); fat (kg) = 11.33 + 0.16 × SBW + 2.09 × uRF - 0.06 × AG (R2 = 0.74, RMSPE = 4.18); water (kg) = - 34.00 + 0.55 × SBW + 0.10 × AG - 2.34 × uRF (R2 = 0.96, RMSPE = 5.47). In conclusion, the coefficients of determination (for determining the chemical composition of the empty body) of the equations derived from in vivo measures were higher than those of the equations obtained from rib section measurements taken postmortem, and better than coefficients of determination of the equations to predict the chemical composition of the carcass.

Simultaneous determination of intestinal permeability and potential drug interactions of complex mixtures using Caco-2 cells and high-resolution mass spectrometry: Studies with Rauwolfia serpentina extract.

PubMed

Flynn, Thomas J; Vohra, Sanah N

2018-06-25

Caco-2 cells are a commonly used model for estimating the intestinal bioavailability of single chemical entity pharmaceuticals. Caco-2 cells, when induced with calcitriol, also express other biological functions such as phase I (CYP) and phase II (glucuronosyltransferases) drug metabolizing enzymes which are relevant to drug-supplement interactions. Intestinal bioavailability is an important factor in the overall safety assessment of products consumed orally. Foods, including herbal dietary supplements, are complex substances with multiple chemical components. Because of potential interactions between components of complex mixtures, more reliable safety assessments can be obtained by studying the commercial products "as consumed" rather than by testing individual chemical components one at a time. The present study evaluated the apparent intestinal permeability (P app ) of a model herbal extract, Rauwolfia serpentina, using both whole plant extracts and the individual purified Rauwolfia alkaloids. All test compounds, endpoint substrates, and their metabolites were quantified using liquid chromatography and high-resolution mass spectrometry. The P app values for individual Rauwolfia alkaloids were comparable whether measured individually or as components of the complete extract. Both Rauwolfia extract and all individual Rauwolfia alkaloids except yohimbine inhibited CYP3A4 activity (midazolam 1'-hydroxylation). Both Rauwolfia extract and all individual Rauwolfia alkaloids except corynanthine and reserpic acid significantly increased glucuronosyltransferase activity (glucuronidation of 4-methylumbelliferone). The positive control, ketoconazole, significantly inhibited both CYP3A4 and glucuronosyltransferase activities. These findings suggest that the Caco-2 assay is capable of simultaneously identifying both bioavailability and potentially hazardous intestinal drug-supplement interactions in complex mixtures. Published by Elsevier B.V.

Carbon-carbon primary structure for SSTO vehicles

NASA Astrophysics Data System (ADS)

Croop, Harold C.; Lowndes, Holland B.

1997-01-01

A hot structures development program is nearing completion to validate use of carbon-carbon composite structure for primary load carrying members in a single-stage-to-orbit, or SSTO, vehicle. A four phase program was pursued which involved design development and fabrication of a full-scale wing torque box demonstration component. The design development included vehicle and component selection, design criteria and approach, design data development, demonstration component design and analysis, test fixture design and analysis, demonstration component test planning, and high temperature test instrumentation development. The fabrication effort encompassed fabrication of structural elements for mechanical property verification as well as fabrication of the demonstration component itself and associated test fixturing. The demonstration component features 3D woven graphite preforms, integral spars, oxidation inhibited matrix, chemical vapor deposited (CVD) SiC oxidation protection coating, and ceramic matrix composite fasteners. The demonstration component has been delivered to the United States Air Force (USAF) for testing in the Wright Laboratory Structural Test Facility, WPAFB, OH. Multiple thermal-mechanical load cycles will be applied simulating two atmospheric cruise missions and one orbital mission. This paper discusses the overall approach to validation testing of the wing box component and presents some preliminary analytical test predictions.

Chapter 5 Multiple, Localized, and Delocalized/Conjugated Bonds in the Orbital Communication Theory of Molecular Systems

NASA Astrophysics Data System (ADS)

Nalewajski, Roman F.

Information theory (IT) probe of the molecular electronic structure, within the communication theory of chemical bonds (CTCB), uses the standard entropy/information descriptors of the Shannon theory of communication to characterize a scattering of the electronic probabilities and their information content throughout the system chemical bonds generated by the occupied molecular orbitals (MO). These "communications" between the basis-set orbitals are determined by the two-orbital conditional probabilities: one- and two-electron in character. They define the molecular information system, in which the electron-allocation "signals" are transmitted between various orbital "inputs" and "outputs". It is argued, using the quantum mechanical superposition principle, that the one-electron conditional probabilities are proportional to the squares of corresponding elements of the charge and bond-order (CBO) matrix of the standard LCAO MO theory. Therefore, the probability of the interorbital connections in the molecular communication system is directly related to Wiberg's quadratic covalency indices of chemical bonds. The conditional-entropy (communication "noise") and mutual-information (information capacity) descriptors of these molecular channels generate the IT-covalent and IT-ionic bond components, respectively. The former reflects the electron delocalization (indeterminacy) due to the orbital mixing, throughout all chemical bonds in the system under consideration. The latter characterizes the localization (determinacy) in the probability scattering in the molecule. These two IT indices, respectively, indicate a fraction of the input information lost in the channel output, due to the communication noise, and its surviving part, due to deterministic elements in probability scattering in the molecular network. Together, these two components generate the system overall bond index. By a straightforward output reduction (condensation) of the molecular channel, the IT indices of molecular fragments, for example, localized bonds, functional groups, and forward and back donations accompanying the bond formation, and so on, can be extracted. The flow of information in such molecular communication networks is investigated in several prototype molecules. These illustrative (model) applications of the orbital communication theory of chemical bonds (CTCB) deal with several classical issues in the electronic structure theory: atom hybridization/promotion, single and multiple chemical bonds, bond conjugation, and so on. The localized bonds in hydrides and delocalized [pi]-bonds in simple hydrocarbons, as well as the multiple bonds in CO and CO2, are diagnosed using the entropy/information descriptors of CTCB. The atom promotion in hydrides and bond conjugation in [pi]-electron systems are investigated in more detail. A major drawback of the previous two-electron approach to molecular channels, namely, two weak bond differentiation in aromatic systems, has been shown to be remedied in the one-electron approach.

Knowledge of Occupational Chemical Exposure and Smoking Behavior in Korean Immigrant Drycleaners.

PubMed

Chin, Dal Lae; Duffy, Sonia A; Hong, OiSaeng

2016-02-01

To examine the association between knowledge of chemical exposure at work and cigarette smoking among Korean immigrant drycleaners. A cross-sectional survey was conducted with a total of 151 Korean immigrant drycleaners (mean age = 49 years, 64 % male) from 96 drycleaning shops in a Midwestern state. The data were collected on demographic and work-related characteristics, knowledge of occupational chemical exposure, health concerns associated with chemical exposure, and smoking status. Approximately 25 % of participants were current smokers. The multivariate regression showed that greater knowledge of occupational chemical exposures was significantly associated with a lower likelihood of current smoking [odds ratio (OR) .63; 95 % confidence interval (CI) .41-.95]. Furthermore, male gender (OR 6.32; 95 % CI 1.66-24.00), shorter-term residence in the US (OR .93; 95 % CI .88-.98), and having multiple duties (OR 2.76; 95 % CI 1.01-7.51) were important covariates associated with current smoking among Korean immigrant drycleaners. Knowledge on occupational chemical exposure was significantly associated with smoking among Korean immigrant drycleaners. Smoking cessation programs for this population should consider integrated approaches that incorporate work environment factors into individual and sociocultural components.

Metabolomics based on liquid chromatography with mass spectrometry reveals the chemical difference in the stems and roots derived from Ephedra sinica.

PubMed

Lv, Mengying; Chen, Jiaqing; Gao, Yiqiao; Sun, Jianbo; Zhang, Qianqian; Zhang, Mohan; Xu, Fengguo; Zhang, Zunjian

2015-10-01

To better understand different traditional uses of the stems (known as Mahuang) and roots (known as Mahuanggen) of Ephedra sinica, their chemical difference should be investigated. In this study, an ultra-fast liquid chromatography coupled with ion trap time-of-flight mass spectrometry untargeted metabolomics approach was established to reveal global chemical difference between Mahuang and Mahuanggen. Clear separation was observed in scores plots of principal component analysis and orthogonal partial least squares-discriminant analysis. Twenty two chemical markers responsible for such separation were screened out and unambiguously/tentatively characterized. Then chemical markers of pharmacologically important ephedrine and pseudoephedrine were absolutely quantified using liquid chromatography coupled with tandem mass spectrometry under multiple reaction monitoring mode. The results showed that Mahuang was rich in ephedrine-type alkaloids, while Mahuanggen was rich in macrocyclic spermine alkaloids. Additionally, different types of flavan-3-ols and flavones exist in Mahuang and Mahuanggen extracts. This research facilitates a better understanding of different traditional uses of Mahuang and Mahuanggen and provides references for chemical analysis of other medicinal plants. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Detection of multiple chemicals based on external cavity quantum cascade laser spectroscopy

NASA Astrophysics Data System (ADS)

Sun, Juan; Ding, Junya; Liu, Ningwu; Yang, Guangxiang; Li, Jingsong

2018-02-01

A laser spectroscopy system based on a broadband tunable external cavity quantum cascade laser (ECQCL) and a mini quartz crystal tuning fork (QCTF) detector was developed for standoff detection of volatile organic compounds (VOCs). The self-established spectral analysis model based on multiple algorithms for quantitative and qualitative analysis of VOC components (i.e. ethanol and acetone) was detailedly investigated in both closed cell and open path configurations. A good agreement was obtained between the experimentally observed spectra and the standard reference spectra. For open path detection of VOCs, the sensor system was demonstrated at a distance of 30 m. The preliminary laboratory results show that standoff detection of VOCs at a distance of over 100 m is very promising.

Linking Remotely Sensed Aerosol Types to Their Chemical Composition

NASA Technical Reports Server (NTRS)

Dawson, Kyle William; Kacenelenbogen, Meloe S.; Johnson, Matthew S.; Burton, Sharon P.; Hostetler, Chris A.; Meskhidze, Nicholas

2016-01-01

Aerosol types measured during the Ship-Aircraft Bio-Optical Research (SABOR) experiment are related to GEOS-Chem model chemical composition. The application for this procedure to link model chemical components to aerosol type is desirable for understanding aerosol evolution over time. The Mahalanobis distance (DM) statistic is used to cluster model groupings of five chemical components (organic carbon, black carbon, sea salt, dust and sulfate) in a way analogous to the methods used by Burton et al. [2012] and Russell et al. [2014]. First, model-to-measurement evaluation is performed by collocating vertically resolved aerosol extinction from SABOR High Spectral Resolution LiDAR (HSRL) to the GEOS-Chem nested high-resolution data. Comparisons of modeled-to-measured aerosol extinction are shown to be within 35% +/- 14%. Second, the model chemical components are calculation into five variables to calculate the DM and cluster means and covariances for each HSRL-retrieved aerosol type. The layer variables from the model are aerosol optical depth (AOD) ratios of (i) sea salt and (ii) dust to total AOD, mass ratios of (iii) total carbon (i.e. sum of organic and black carbon) to the sum of total carbon and sulfate (iv) organic carbon to black carbon, and (v) the natural log of the aerosol-to-molecular extinction ratio. Third, the layer variables and at most five out of twenty SABOR flights are used to form the pre-specified clusters for calculating DM and to assign an aerosol type. After determining the pre-specified clusters, model aerosol types are produced for the entire vertically resolved GEOS-Chem nested domain over the United States and the model chemical component distributions relating to each type are recorded. Resulting aerosol types are Dust/Dusty Mix, Maritime, Smoke, Urban and Fresh Smoke (separated into 'dark' and 'light' by a threshold of the organic to black carbon ratio). Model-calculated DM not belonging to a specific type (i.e. not meeting a threshold probability) is termed an outlier and those DM values that can belong to multiple types (i.e. showing weak probability of belonging to a specific cluster) are termed as Overlap. MODIS active fires are overlaid on the model domain to qualitatively evaluate the model-predicted Smoke aerosol types.

Linking remotely sensed aerosol types to their chemical composition

NASA Astrophysics Data System (ADS)

Dawson, K. W.; Kacenelenbogen, M. S.; Johnson, M. S.; Burton, S. P.; Hostetler, C. A.; Meskhidze, N.

2016-12-01

Aerosol types measured during the Ship-Aircraft Bio-Optical Research (SABOR) experiment are related to GEOS-Chem model chemical composition. The application for this procedure to link model chemical components to aerosol type is desirable for understanding aerosol evolution over time. The Mahalanobis distance (DM) statistic is used to cluster model groupings of five chemical components (organic carbon, black carbon, sea salt, dust and sulfate) in a way analogous to the methods used by Burton et al. [2012] and Russell et al. [2014]. First, model-to-measurement evaluation is performed by collocating vertically resolved aerosol extinction from SABOR High Spectral Resolution LiDAR (HSRL) to the GEOS-Chem nested high-resolution data. Comparisons of modeled-to-measured aerosol extinction are shown to be within 35% ± 14%. Second, the model chemical components are calculation into five variables to calculate the DM and cluster means and covariances for each HSRL-retrieved aerosol type. The layer variables from the model are aerosol optical depth (AOD) ratios of (i) sea salt and (ii) dust to total AOD, mass ratios of (iii) total carbon (i.e. sum of organic and black carbon) to the sum of total carbon and sulfate (iv) organic carbon to black carbon, and (v) the natural log of the aerosol-to-molecular extinction ratio. Third, the layer variables and at most five out of twenty SABOR flights are used to form the pre-specified clusters for calculating DM and to assign an aerosol type. After determining the pre-specified clusters, model aerosol types are produced for the entire vertically resolved GEOS-Chem nested domain over the United States and the model chemical component distributions relating to each type are recorded. Resulting aerosol types are Dust/Dusty Mix, Maritime, Smoke, Urban and Fresh Smoke (separated into `dark' and `light' by a threshold of the organic to black carbon ratio). Model-calculated DM not belonging to a specific type (i.e. not meeting a threshold probability) is termed an outlier and those DM values that can belong to multiple types (i.e. showing weak probability of belonging to a specific cluster) are termed as Overlap. MODIS active fires are overlaid on the model domain to qualitatively evaluate the model-predicted Smoke aerosol types.

Linear Quantitative Profiling Method Fast Monitors Alkaloids of Sophora Flavescens That Was Verified by Tri-Marker Analyses.

PubMed

Hou, Zhifei; Sun, Guoxiang; Guo, Yong

2016-01-01

The present study demonstrated the use of the Linear Quantitative Profiling Method (LQPM) to evaluate the quality of Alkaloids of Sophora flavescens (ASF) based on chromatographic fingerprints in an accurate, economical and fast way. Both linear qualitative and quantitative similarities were calculated in order to monitor the consistency of the samples. The results indicate that the linear qualitative similarity (LQLS) is not sufficiently discriminating due to the predominant presence of three alkaloid compounds (matrine, sophoridine and oxymatrine) in the test samples; however, the linear quantitative similarity (LQTS) was shown to be able to obviously identify the samples based on the difference in the quantitative content of all the chemical components. In addition, the fingerprint analysis was also supported by the quantitative analysis of three marker compounds. The LQTS was found to be highly correlated to the contents of the marker compounds, indicating that quantitative analysis of the marker compounds may be substituted with the LQPM based on the chromatographic fingerprints for the purpose of quantifying all chemicals of a complex sample system. Furthermore, once reference fingerprint (RFP) developed from a standard preparation in an immediate detection way and the composition similarities calculated out, LQPM could employ the classical mathematical model to effectively quantify the multiple components of ASF samples without any chemical standard.

A possible four-phase coexistence in a single-component system

NASA Astrophysics Data System (ADS)

Akahane, Kenji; Russo, John; Tanaka, Hajime

2016-08-01

For different phases to coexist in equilibrium at constant temperature T and pressure P, the condition of equal chemical potential μ must be satisfied. This condition dictates that, for a single-component system, the maximum number of phases that can coexist is three. Historically this is known as the Gibbs phase rule, and is one of the oldest and venerable rules of thermodynamics. Here we make use of the fact that, by varying model parameters, the Gibbs phase rule can be generalized so that four phases can coexist even in single-component systems. To systematically search for the quadruple point, we use a monoatomic system interacting with a Stillinger-Weber potential with variable tetrahedrality. Our study indicates that the quadruple point provides flexibility in controlling multiple equilibrium phases and may be realized in systems with tunable interactions, which are nowadays feasible in several soft matter systems such as patchy colloids.

Application of carbon nanotube hold-off voltage for determining gas composition

NASA Technical Reports Server (NTRS)

Schipper, John F. (Inventor); Li, Jing (Inventor)

2009-01-01

Method and system for determining chemical composition of a single-component or multiple-component gas, using a discharge holdoff mechanism. A voltage difference V between two spaced apart electrodes is brought to a selected value and held, the holdoff time interval .DELTA.t(V;ho) required before gas discharge occurs is measured, and the associated electrical current or cumulative electrical charge is measured. As the voltage difference V increases, the time interval length .DELTA.t(V;ho) decreases monotonically. Particular voltage values, V.sub..infin. and V.sub.0, correspond to initial appearance of discharge (.DELTA.t.apprxeq..infin.) and prompt discharge (.DELTA.t.apprxeq.0). The values V.sub..infin. and V.sub.0 and the rate of decrease of .DELTA.t(V;ho) and/or the rate of increase of current or cumulative charge with increasing V are characteristic of one or more gas components present.

A possible four-phase coexistence in a single-component system

PubMed Central

Akahane, Kenji; Russo, John; Tanaka, Hajime

2016-01-01

For different phases to coexist in equilibrium at constant temperature T and pressure P, the condition of equal chemical potential μ must be satisfied. This condition dictates that, for a single-component system, the maximum number of phases that can coexist is three. Historically this is known as the Gibbs phase rule, and is one of the oldest and venerable rules of thermodynamics. Here we make use of the fact that, by varying model parameters, the Gibbs phase rule can be generalized so that four phases can coexist even in single-component systems. To systematically search for the quadruple point, we use a monoatomic system interacting with a Stillinger–Weber potential with variable tetrahedrality. Our study indicates that the quadruple point provides flexibility in controlling multiple equilibrium phases and may be realized in systems with tunable interactions, which are nowadays feasible in several soft matter systems such as patchy colloids. PMID:27558452

Boron Carbide: Stabilization of Highly-Loaded Aqueous Suspensions, Pressureless Sintering, and Room Temperature Injection Molding

NASA Astrophysics Data System (ADS)

Diaz-Cano, Andres

Boron carbide (B4C) is the third hardest material after diamond and cubic boron nitride. It's unique combination of properties makes B4C a highly valuable material. With hardness values around 35 MPa, a high melting point, 2450°C, density of 2.52 g/cm3, and high chemical inertness, boron carbide is used in severe wear components, like cutting tools and sandblasting nozzles, nuclear reactors' control rots, and finally and most common application, armor. Production of complex-shaped ceramic component is complex and represents many challenges. Present research presents a new and novel approach to produce complex-shaped B4C components. Proposed approach allows forming to be done at room temperatures and under very low forming pressures. Additives and binder concentrations are kept as low as possible, around 5Vol%, while ceramics loadings are maximized above 50Vol%. Given that proposed approach uses water as the main solvent, pieces drying is simple and environmentally safe. Optimized formulation allows rheological properties to be tailored and adjust to multiple processing approaches, including, injection molding, casting, and additive manufacturing. Boron carbide samples then were pressureless sintered. Due to the high covalent character of boron carbide, multiples sintering aids and techniques have been proposed in order to achieve high levels of densification. However, is not possible to define a clear sintering methodology based on literature. Thus, present research developed a comprehensive study on the effect of multiple sintering aids on the densification of boron carbide when pressureless sintered. Relative densities above 90% were achieved with values above 30MPa in hardness. Current research allows extending the uses and application of boron carbide, and other ceramic systems, by providing a new approach to produce complex-shaped components with competitive properties.

Prediction of the true digestible amino acid contents from the chemical composition of sorghum grain for poultry.

PubMed

Ebadi, M R; Sedghi, M; Golian, A; Ahmadi, H

2011-10-01

Accurate knowledge of true digestible amino acid (TDAA) contents of feedstuffs is necessary to accurately formulate poultry diets for profitable production. Several experimental approaches that are highly expensive and time consuming have been used to determine available amino acids. Prediction of the nutritive value of a feed ingredient from its chemical composition via regression methodology has been attempted for many years. The artificial neural network (ANN) model is a powerful method that may describe the relationship between digestible amino acid contents and chemical composition. Therefore, multiple linear regressions (MLR) and ANN models were developed for predicting the TDAA contents of sorghum grain based on chemical composition. A precision-fed assay trial using cecectomized roosters was performed to determine the TDAA contents in 48 sorghum samples from 12 sorghum varieties differing in chemical composition. The input variables for both MLR and ANN models were CP, ash, crude fiber, ether extract, and total phenols whereas the output variable was each individual TDAA for every sample. The results of this study revealed that it is possible to satisfactorily estimate the TDAA of sorghum grain through its chemical composition. The chemical composition of sorghum grain seems to highly influence the TDAA contents when considering components such as CP, crude fiber, ether extract, ash and total phenols. It is also possible to estimate the TDAA contents through multiple regression equations with reasonable accuracy depending on composition. However, a more satisfactory prediction may be achieved via ANN for all amino acids. The R(2) values for the ANN model corresponding to testing and training parameters showed a higher accuracy of prediction than equations established by the MLR method. In addition, the current data confirmed that chemical composition, often considered in total amino acid prediction, could be also a useful predictor of true digestible values of selected amino acids for poultry.

Respiratory hospitalizations in association with fine PM and its ...

EPA Pesticide Factsheets

Despite observed geographic and temporal variation in particulate matter (PM)-related health morbidities, only a small number of epidemiologic studies have evaluated the relation between PM2.5 chemical constituents and respiratory disease. Most assessments are limited by inadequate spatial and temporal resolution of ambient PM measurements and/or by their approaches to examine the role of specific PM components on health outcomes. In a case-crossover analysis using daily average ambient PM2.5 total mass and species estimates derived from the Community Multiscale Air Quality (CMAQ) model and available observations, we examined the association between the chemical components of PM (including elemental and organic carbon, sulfate, nitrate, ammonium, and other remaining) and respiratory hospitalizations in New York State. We evaluated relationships between levels (low, medium, high) of PM constituent mass fractions, and assessed modification of the PM2.5–hospitalization association via models stratified by mass fractions of both primary and secondary PM components. In our results, average daily PM2.5 concentrations in New York State were generally lower than the 24-hr average National Ambient Air Quality Standard (NAAQS). Year-round analyses showed statistically significant positive associations between respiratory hospitalizations and PM2.5 total mass, sulfate, nitrate, and ammonium concentrations at multiple exposure lags (0.5–2.0% per interquartile range [IQR

Characterization of the antibacterial activity and the chemical components of the volatile oil of the leaves of Rubus parvifolius L.

PubMed

Cai, Yongqing; Hu, Xiaogang; Huang, Mingchun; Sun, Fengjun; Yang, Bo; He, Juying; Wang, Xianfeng; Xia, Peiyuan; Chen, Jianhong

2012-06-25

Rubus parvifolius L. (Rp) is a medicinal herb that possesses antibacterial activity. In this study, we extracted the volatile oil from the leaves of Rp to assess its antibacterial activity and analyze its chemical composition. A uniform distribution design was used to optimize the extraction procedure, which yielded 0.36% (w/w) of light yellowish oil from the water extract of Rp leaves. We found that the extracted oil effectively inhibited the growth of a wide range of Gram positive and negative bacteria, including Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumanii, Bacillus cloacae, and Klebsiella pneumoniae. We further analyzed the components contained in the hydro-distillated Rp volatile oil by gas chromatography-mass spectroscopy. Twenty nine compounds were identified, including 4-hydroxy-3-methoxystyrene (66%), 3,7,11,15-tetramethyl-2-hexadecen-1-ol (10%) and 4-tert-butylbenzoic acid (2%). Our results suggest that one or multiple constituents contained in Rp volatile oil may account for its antibacterial activity.

A multiple-dimension liquid chromatography coupled with mass spectrometry data strategy for the rapid discovery and identification of unknown compounds from a Chinese herbal formula (Er-xian decoction).

PubMed

Wang, Caihong; Zhang, Jinlan; Wu, Caisheng; Wang, Zhe

2017-10-06

It is very important to rapidly discover and identify the multiple components of traditional Chinese medicine (TCM) formula. High performance liquid chromatography with high resolution tandem mass spectrometry (HPLC-HRMS/MS) has been widely used to analyze TCM formula and contains multiple-dimension data including retention time (RT), high resolution mass (HRMS), multiple-stage mass spectrometric (MS n ), and isotope intensity distribution (IID) data. So it is very necessary to exploit a useful strategy to utilize multiple-dimension data to rapidly probe structural information and identify chemical compounds. In this study, a new strategy to initiatively use the multiple-dimension LC-MS data has been developed to discover and identify unknown compounds of TCM in many styles. The strategy guarantees the fast discovery of candidate structural information and provides efficient structure clues for identification. The strategy contains four steps in sequence: (1) to discover potential compounds and obtain sub-structure information by the mass spectral tree similarity filter (MTSF) technique, based on HRMS and MS n data; (2) to classify potential compounds into known chemical classes by discriminant analysis (DA) on the basis of RT and HRMS data; (3) to hit the candidate structural information of compounds by intersection sub-structure between MTSF and DA (M,D-INSS); (4) to annotate and confirm candidate structures by IID data. This strategy allowed for the high exclusion efficiency (greater than 41%) of irrelevant ions in er-xian decoction (EXD) while providing accurate structural information of 553 potential compounds and identifying 66 candidates, therefore accelerating and simplifying the discovery and identification of unknown compounds in TCM formula. Copyright © 2017 Elsevier B.V. All rights reserved.

A Summary of Publications on the Development of Mode-of ...

EPA Pesticide Factsheets

Chemical contaminants are formed as a consequence of chemical disinfection of public drinking waters. Chemical disinfectants, which are used to kill harmful microorganisms, react with natural organic matter (NOM), bromide, iodide, and other compounds, forming complex mixtures of potentially toxic disinfection byproducts (DBPs). The types and concentrations of DBPs formed during disinfection and the relative proportions of the components vary depending on factors such as source water conditions (e.g., types of NOM present), disinfectant type (e.g., chlorine, ozone, chloramine), and treatment conditions (e.g., pH and temperature). To date, over 500 DBPs have been detected in treated waters. However, typically more than 50% of the organic halide mass produced by chlorination disinfection consists of unidentified chemicals, which are not measured by routine analyses of DBPs. The protocols and methods typically used to evaluate chemical mixtures are best applied to simple defined mixtures consisting of relatively few chemicals. These approaches rely on assumptions (e.g., common mode of action, independent toxic action) regarding the type of joint toxic action (e.g., dose-additivity, synergism) that might be observed. Such methods, used for site assessments or toxicological studies, are often not sufficient to estimate health risk for complex drinking water DBP mixtures. Actual drinking water exposures involve multiple chemicals, many of w

Influence factors of multicomponent mixtures containing reactive chemicals and their joint effects.

PubMed

Tian, Dayong; Lin, Zhifen; Yu, Jianqiao; Yin, Daqiang

2012-08-01

Organic chemicals usually coexist as a mixture in the environment, and the mixture toxicity of organic chemicals has received increased attention. However, research regarding the joint effects of reactive chemicals is lacking. In this study, we examined two kinds of reactive chemicals, cyanogenic toxicants and aldehydes and determined their joint effects on Photobacterium phosphoreum. Three factors were found to influence the joint effects of multicomponent mixtures containing reactive chemicals, including the number of components, the dominating components and the toxic ratios. With an increased number of components, the synergistic or antagonistic effects (interactions) will weaken to the additive effects (non-interactions) if the added component cannot yield a much stronger joint effect with an existing component. Contrarily, the joint effect of the mixture may become stronger instead of weaker if the added components can yield a much stronger joint effect than the existing joint effect of the multicomponent mixture. The components that yield the strongest interactions in their binary mixture can be considered the dominating components. These components contribute more to the interactions of multicomponent mixtures than other components. Moreover, the toxic ratios also influence the joint effects of the mixtures. This study provides an insight into what are the main factors and how they influence the joint effects of multicomponent mixtures containing reactive chemicals, and thus, the findings are beneficial to the study of mixture toxicology. Copyright © 2012 Elsevier Ltd. All rights reserved.

Single-Cell RT-PCR in Microfluidic Droplets with Integrated Chemical Lysis.

PubMed

Kim, Samuel C; Clark, Iain C; Shahi, Payam; Abate, Adam R

2018-01-16

Droplet microfluidics can identify and sort cells using digital reverse transcription polymerase chain reaction (RT-PCR) signals from individual cells. However, current methods require multiple microfabricated devices for enzymatic cell lysis and PCR reagent addition, making the process complex and prone to failure. Here, we describe a new approach that integrates all components into a single device. The method enables controlled exposure of isolated single cells to a high pH buffer, which lyses cells and inactivates reaction inhibitors but can be instantly neutralized with RT-PCR buffer. Using our chemical lysis approach, we distinguish individual cells' gene expression with data quality equivalent to more complex two-step workflows. Our system accepts cells and produces droplets ready for amplification, making single-cell droplet RT-PCR faster and more reliable.

Waste IPSC : Thermal-Hydrologic-Chemical-Mechanical (THCM) modeling and simulation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freeze, Geoffrey A.; Wang, Yifeng; Arguello, Jose Guadalupe, Jr.

2010-10-01

Waste IPSC Objective is to develop an integrated suite of high performance computing capabilities to simulate radionuclide movement through the engineered components and geosphere of a radioactive waste storage or disposal system: (1) with robust thermal-hydrologic-chemical-mechanical (THCM) coupling; (2) for a range of disposal system alternatives (concepts, waste form types, engineered designs, geologic settings); (3) for long time scales and associated large uncertainties; (4) at multiple model fidelities (sub-continuum, high-fidelity continuum, PA); and (5) in accordance with V&V and software quality requirements. THCM Modeling collaborates with: (1) Other Waste IPSC activities: Sub-Continuum Processes (and FMM), Frameworks and Infrastructure (and VU,more » ECT, and CT); (2) Waste Form Campaign; (3) Used Fuel Disposition (UFD) Campaign; and (4) ASCEM.« less

An Improved Weighted Partial Least Squares Method Coupled with Near Infrared Spectroscopy for Rapid Determination of Multiple Components and Anti-Oxidant Activity of Pu-Erh Tea.

PubMed

Liu, Ze; Xie, Hua-Lin; Chen, Lin; Huang, Jian-Hua

2018-05-02

Background: Pu-erh tea is a unique microbially fermented tea, which distinctive chemical constituents and activities are worthy of systematic study. Near infrared spectroscopy (NIR) coupled with suitable chemometrics approaches can rapidly and accurately quantitatively analyze multiple compounds in samples. Methods: In this study, an improved weighted partial least squares (PLS) algorithm combined with near infrared spectroscopy (NIR) was used to construct a fast calibration model for determining four main components, i.e., tea polyphenols, tea polysaccharide, total flavonoids, theanine content, and further determine the total antioxidant capacity of pu-erh tea. Results: The final correlation coefficients R square for tea polyphenols, tea polysaccharide, total flavonoids content, theanine content, and total antioxidant capacity were 0.8288, 0.8403, 0.8415, 0.8537 and 0.8682, respectively. Conclusions : The current study provided a comprehensive study of four main ingredients and activity of pu-erh tea, and demonstrated that NIR spectroscopy technology coupled with multivariate calibration analysis could be successfully applied to pu-erh tea quality assessment.

Multi-Stimuli Responsive Macromolecules and Their Assemblies

PubMed Central

Zhuang, Jiaming; Gordon, Mallory; Ventura, Judy; Li, Longyu; Thayumanavan, S.

2013-01-01

In this review, we outline examples that illustrate the design criteria for achieving macromolecular assemblies that incorporate a combination of two or more chemical, physical or biological stimuli-responsive components. Progress in both fundamental investigation into the phase transformations of these polymers in response to multiple stimuli and their utilization in a variety of pratical applications have been highlighted. Using these examples, we aim to explain the origin of employed mechanisms of stimuli responsiveness which may serve as a guideline to inspire future design of multi-stimuli responsive materials. PMID:23765263

21 CFR 888.3030 - Single/multiple component metallic bone fixation appliances and accessories.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Single/multiple component metallic bone fixation....3030 Single/multiple component metallic bone fixation appliances and accessories. (a) Identification. Single/multiple component metallic bone fixation appliances and accessories are devices intended to be...

21 CFR 888.3030 - Single/multiple component metallic bone fixation appliances and accessories.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Single/multiple component metallic bone fixation....3030 Single/multiple component metallic bone fixation appliances and accessories. (a) Identification. Single/multiple component metallic bone fixation appliances and accessories are devices intended to be...

21 CFR 888.3030 - Single/multiple component metallic bone fixation appliances and accessories.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Single/multiple component metallic bone fixation....3030 Single/multiple component metallic bone fixation appliances and accessories. (a) Identification. Single/multiple component metallic bone fixation appliances and accessories are devices intended to be...

21 CFR 888.3030 - Single/multiple component metallic bone fixation appliances and accessories.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Single/multiple component metallic bone fixation....3030 Single/multiple component metallic bone fixation appliances and accessories. (a) Identification. Single/multiple component metallic bone fixation appliances and accessories are devices intended to be...

21 CFR 888.3030 - Single/multiple component metallic bone fixation appliances and accessories.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Single/multiple component metallic bone fixation....3030 Single/multiple component metallic bone fixation appliances and accessories. (a) Identification. Single/multiple component metallic bone fixation appliances and accessories are devices intended to be...

Understanding the Molecular Mechanisms of the Interplay Between Herbal Medicines and Gut Microbiota.

PubMed

Xu, Jun; Chen, Hu-Biao; Li, Song-Lin

2017-09-01

Herbal medicines (HMs) are much appreciated for their significant contribution to human survival and reproduction by remedial and prophylactic management of diseases. Defining the scientific basis of HMs will substantiate their value and promote their modernization. Ever-increasing evidence suggests that gut microbiota plays a crucial role in HM therapy by complicated interplay with HM components. This interplay includes such activities as: gut microbiota biotransforming HM chemicals into metabolites that harbor different bioavailability and bioactivity/toxicity from their precursors; HM chemicals improving the composition of gut microbiota, consequently ameliorating its dysfunction as well as associated pathological conditions; and gut microbiota mediating the interactions (synergistic and antagonistic) between the multiple chemicals in HMs. More advanced experimental designs are recommended for future study, such as overall chemical characterization of gut microbiota-metabolized HMs, direct microbial analysis of HM-targeted gut microbiota, and precise gut microbiota research model development. The outcomes of such research can further elucidate the interactions between HMs and gut microbiota, thereby opening a new window for defining the scientific basis of HMs and for guiding HM-based drug discovery. © 2016 Wiley Periodicals, Inc.

Chemical and technical challenges in the analysis of central carbon metabolites by liquid-chromatography mass spectrometry.

PubMed

Siegel, David; Permentier, Hjalmar; Reijngoud, Dirk-Jan; Bischoff, Rainer

2014-09-01

This review deals with chemical and technical challenges in the analysis of small-molecule metabolites involved in central carbon and energy metabolism via liquid-chromatography mass-spectrometry (LC-MS). The covered analytes belong to the prominent pathways in biochemical carbon oxidation such as glycolysis or the tricarboxylic acid cycle and, for the most part, share unfavorable properties such as a high polarity, chemical instability or metal-affinity. The topic is introduced by selected examples on successful applications of metabolomics in the clinic. In the core part of the paper, the structural features of important analyte classes such as nucleotides, coenzyme A thioesters or carboxylic acids are linked to "problematic hotspots" along the analytical chain (sample preparation and-storage, separation and detection). We discuss these hotspots from a chemical point of view, covering issues such as analyte degradation or interactions with metals and other matrix components. Based on this understanding we propose solutions wherever available. A major notion derived from these considerations is that comprehensive carbon metabolomics inevitably requires multiple, complementary analytical approaches covering different chemical classes of metabolites. Copyright © 2013 Elsevier B.V. All rights reserved.

Evidence-based patient decontamination: an integral component of mass exposure chemical incident planning and response.

PubMed

Leary, Adam D; Schwartz, Michael D; Kirk, Mark A; Ignacio, Joselito S; Wencil, Elaine B; Cibulsky, Susan M

2014-06-01

Decontaminating patients who have been exposed to hazardous chemicals can directly benefit the patients' health by saving lives and reducing the severity of toxicity. While the importance of decontaminating patients to prevent the spread of contamination has long been recognized, its role in improving patient health outcomes has not been as widely appreciated. Acute chemical toxicity may manifest rapidly-often minutes to hours after exposure. Patient decontamination and emergency medical treatment must be initiated as early as possible to terminate further exposure and treat the effects of the dose already absorbed. In a mass exposure chemical incident, responders and receivers are faced with the challenges of determining the type of care that each patient needs (including medical treatment, decontamination, and behavioral health support), providing that care within the effective window of time, and protecting themselves from harm. The US Department of Health and Human Services and Department of Homeland Security have led the development of national planning guidance for mass patient decontamination in a chemical incident to help local communities meet these multiple, time-sensitive health demands. This report summarizes the science on which the guidance is based and the principles that form the core of the updated approach.

Introductory Talk: Adding Up Chemicals: Component-Based Risk Assessment of Chemical Mixturesand Primary Talk: Grouping Chemicals for Assessment and Conducting Assessments with the Hazard Index and Related Methods

EPA Science Inventory

Dr. Simmons will provide a concise overview of established and emerging methods to group chemicals for component-based mixture risk assessments. This will be followed by introduction to several important component-based methods, the Hazard Index, Target Organ Hazard Index, Multi...

A Paper-Based Device for Performing Loop-Mediated Isothermal Amplification with Real-Time Simultaneous Detection of Multiple DNA Targets.

PubMed

Seok, Youngung; Joung, Hyou-Arm; Byun, Ju-Young; Jeon, Hyo-Sung; Shin, Su Jeong; Kim, Sanghyo; Shin, Young-Beom; Han, Hyung Soo; Kim, Min-Gon

2017-01-01

Paper-based diagnostic devices have many advantages as a one of the multiple diagnostic test platforms for point-of-care (POC) testing because they have simplicity, portability, and cost-effectiveness. However, despite high sensitivity and specificity of nucleic acid testing (NAT), the development of NAT based on a paper platform has not progressed as much as the others because various specific conditions for nucleic acid amplification reactions such as pH, buffer components, and temperature, inhibitions from technical differences of paper-based device. Here, we propose a paper-based device for performing loop-mediated isothermal amplification (LAMP) with real-time simultaneous detection of multiple DNA targets. We determined the optimal chemical components to enable dry conditions for the LAMP reaction without lyophilization or other techniques. We also devised the simple paper device structure by sequentially stacking functional layers, and employed a newly discovered property of hydroxynaphthol blue fluorescence to analyze real-time LAMP signals in the paper device. This proposed platform allowed analysis of three different meningitis DNA samples in a single device with single-step operation. This LAMP-based multiple diagnostic device has potential for real-time analysis with quantitative detection of 10 2 -10 5 copies of genomic DNA. Furthermore, we propose the transformation of DNA amplification devices to a simple and affordable paper system approach with great potential for realizing a paper-based NAT system for POC testing.

A Paper-Based Device for Performing Loop-Mediated Isothermal Amplification with Real-Time Simultaneous Detection of Multiple DNA Targets

PubMed Central

Seok, Youngung; Joung, Hyou-Arm; Byun, Ju-Young; Jeon, Hyo-Sung; Shin, Su Jeong; Kim, Sanghyo; Shin, Young-Beom; Han, Hyung Soo; Kim, Min-Gon

2017-01-01

Paper-based diagnostic devices have many advantages as a one of the multiple diagnostic test platforms for point-of-care (POC) testing because they have simplicity, portability, and cost-effectiveness. However, despite high sensitivity and specificity of nucleic acid testing (NAT), the development of NAT based on a paper platform has not progressed as much as the others because various specific conditions for nucleic acid amplification reactions such as pH, buffer components, and temperature, inhibitions from technical differences of paper-based device. Here, we propose a paper-based device for performing loop-mediated isothermal amplification (LAMP) with real-time simultaneous detection of multiple DNA targets. We determined the optimal chemical components to enable dry conditions for the LAMP reaction without lyophilization or other techniques. We also devised the simple paper device structure by sequentially stacking functional layers, and employed a newly discovered property of hydroxynaphthol blue fluorescence to analyze real-time LAMP signals in the paper device. This proposed platform allowed analysis of three different meningitis DNA samples in a single device with single-step operation. This LAMP-based multiple diagnostic device has potential for real-time analysis with quantitative detection of 102-105 copies of genomic DNA. Furthermore, we propose the transformation of DNA amplification devices to a simple and affordable paper system approach with great potential for realizing a paper-based NAT system for POC testing. PMID:28740546

Properties of six short-period massive binaries: A study of the effects of binarity on surface chemical abundances

NASA Astrophysics Data System (ADS)

Martins, F.; Mahy, L.; Hervé, A.

2017-11-01

Context. A significant percentage of massive stars are found in multiple systems. The effect of binarity on stellar evolution is poorly constrained. In particular, the role of tides and mass transfer on surface chemical abundances is not constrained observationally. Aims: The aim of this study is to investigate the effect of binarity on the stellar properties and surface abundances of massive binaries. Methods: We performed a spectroscopic analysis of six Galactic massive binaries. We obtained the spectra of individual components via a spectral disentangling method and subsequently analyzed these spectra by means of atmosphere models. The stellar parameters and CNO surface abundances were determined. Results: Most of these six systems are comprised of main-sequence stars. Three systems are detached, two are in contact, and no information is available for the sixth system. For 11 out of the 12 stars studied, the surface abundances are only mildly affected by stellar evolution and mixing. The surface abundances are not different from those of single stars within the uncertainties. The secondary of XZ Cep is strongly chemically enriched. Considering previous determinations of surface abundances in massive binary systems suggests that the effect of tides on chemical mixing is limited, whereas the mass transfer and removal of outer layers of the mass donor leads to the appearance of chemically processed material at the surface, although this is not systematic. The evolutionary masses of the components of our six systems are on average 16.5% higher than the dynamical masses. Some systems seem to have reached synchronization, while others may still be in a transitory phase. Based on observations made with the SOPHIE spectrograph on the 1.93 m telescope at Observatoire de Haute-Provence (OHP, CNRS/AMU), France.

Engineering the biological conversion of methanol to specialty chemicals in Escherichia coli

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whitaker, W. Brian; Jones, J. Andrew; Bennett, R. Kyle

Methanol is an attractive substrate for biological production of chemicals and fuels. Engineering methylotrophic Escherichia coli as a platform organism for converting methanol to metabolites is desirable. Prior efforts to engineer methylotrophic E. coli were limited by methanol dehydrogenases (Mdhs) with unfavorable enzyme kinetics. We engineered E. coli to utilize methanol using a superior NAD-dependent Mdh from Bacillus stearothermophilus and ribulose monophosphate (RuMP) pathway enzymes from B. methanolicus. Using 13C-labeling, we demonstrate this E. coli strain converts methanol into biomass components. For example, the key TCA cycle intermediates, succinate and malate, exhibit labeling up to 39%, while the lower glycolyticmore » intermediate, 3-phosphoglycerate, up to 53%. Multiple carbons are labeled for each compound, demonstrating a cycling RuMP pathway for methanol assimilation to support growth. In conclusion, by incorporating the pathway to synthesize the flavanone naringenin, we demonstrate the first example of in vivo conversion of methanol into a specialty chemical in E. coli.« less

Engineering the biological conversion of methanol to specialty chemicals in Escherichia coli

DOE PAGES

Whitaker, W. Brian; Jones, J. Andrew; Bennett, R. Kyle; ...

2016-11-01

Methanol is an attractive substrate for biological production of chemicals and fuels. Engineering methylotrophic Escherichia coli as a platform organism for converting methanol to metabolites is desirable. Prior efforts to engineer methylotrophic E. coli were limited by methanol dehydrogenases (Mdhs) with unfavorable enzyme kinetics. We engineered E. coli to utilize methanol using a superior NAD-dependent Mdh from Bacillus stearothermophilus and ribulose monophosphate (RuMP) pathway enzymes from B. methanolicus. Using 13C-labeling, we demonstrate this E. coli strain converts methanol into biomass components. For example, the key TCA cycle intermediates, succinate and malate, exhibit labeling up to 39%, while the lower glycolyticmore » intermediate, 3-phosphoglycerate, up to 53%. Multiple carbons are labeled for each compound, demonstrating a cycling RuMP pathway for methanol assimilation to support growth. In conclusion, by incorporating the pathway to synthesize the flavanone naringenin, we demonstrate the first example of in vivo conversion of methanol into a specialty chemical in E. coli.« less

Engineering the biological conversion of methanol to specialty chemicals in Escherichia coli.

PubMed

Whitaker, W Brian; Jones, J Andrew; Bennett, R Kyle; Gonzalez, Jacqueline E; Vernacchio, Victoria R; Collins, Shannon M; Palmer, Michael A; Schmidt, Samuel; Antoniewicz, Maciek R; Koffas, Mattheos A; Papoutsakis, Eleftherios T

2017-01-01

Methanol is an attractive substrate for biological production of chemicals and fuels. Engineering methylotrophic Escherichia coli as a platform organism for converting methanol to metabolites is desirable. Prior efforts to engineer methylotrophic E. coli were limited by methanol dehydrogenases (Mdhs) with unfavorable enzyme kinetics. We engineered E. coli to utilize methanol using a superior NAD-dependent Mdh from Bacillus stearothermophilus and ribulose monophosphate (RuMP) pathway enzymes from B. methanolicus. Using 13 C-labeling, we demonstrate this E. coli strain converts methanol into biomass components. For example, the key TCA cycle intermediates, succinate and malate, exhibit labeling up to 39%, while the lower glycolytic intermediate, 3-phosphoglycerate, up to 53%. Multiple carbons are labeled for each compound, demonstrating a cycling RuMP pathway for methanol assimilation to support growth. By incorporating the pathway to synthesize the flavanone naringenin, we demonstrate the first example of in vivo conversion of methanol into a specialty chemical in E. coli. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Synergistic activation of human pregnane X receptor by binary cocktails of pharmaceutical and environmental compounds

PubMed Central

Delfosse, Vanessa; Dendele, Béatrice; Huet, Tiphaine; Grimaldi, Marina; Boulahtouf, Abdelhay; Gerbal-Chaloin, Sabine; Beucher, Bertrand; Roecklin, Dominique; Muller, Christina; Rahmani, Roger; Cavaillès, Vincent; Daujat-Chavanieu, Martine; Vivat, Valérie; Pascussi, Jean-Marc; Balaguer, Patrick; Bourguet, William

2015-01-01

Humans are chronically exposed to multiple exogenous substances, including environmental pollutants, drugs and dietary components. Many of these compounds are suspected to impact human health, and their combination in complex mixtures could exacerbate their harmful effects. Here we demonstrate that a pharmaceutical oestrogen and a persistent organochlorine pesticide, both exhibiting low efficacy when studied separately, cooperatively bind to the pregnane X receptor, leading to synergistic activation. Biophysical analysis shows that each ligand enhances the binding affinity of the other, so the binary mixture induces a substantial biological response at doses at which each chemical individually is inactive. High-resolution crystal structures reveal the structural basis for the observed cooperativity. Our results suggest that the formation of ‘supramolecular ligands' within the ligand-binding pocket of nuclear receptors contributes to the synergistic toxic effect of chemical mixtures, which may have broad implications for the fields of endocrine disruption, toxicology and chemical risk assessment. PMID:26333997

Skin lipids of the striped plateau lizard (Sceloporus virgatus) correlate with female receptivity and reproductive quality alongside visual ornaments.

PubMed

Goldberg, Jay K; Wallace, Alisa K; Weiss, Stacey L

2017-09-14

Sex pheromones can perform a variety of functions ranging from revealing the location of suitable mates to being honest signals of mate quality, and they are used in the mate selection process by many species of reptile. In this study, we determined whether the skin lipids of female striped plateau lizards (Sceloporus virgatus) can predict the reproductive quality of females, thereby having the potential to serve as pheromones. Using gas chromatography/mass spectrometry, we identified 17 compounds present in skin lipids of female lizards. Using principal component analysis to compare the skin lipid profile of receptive and non-receptive females, we determined that an uncharacterized compound may allow for chemical identification of receptive mates. We also compared extracted principal components to measures of female fitness and reproductive qualities and found that the level of two 18 carbon fatty acids present in a female's skin lipids may indicate her clutch size. Finally, we compared the information content of the skin lipids to that of female-specific color ornaments to assess whether chemical and visual cues transmit different information or not. We found that the chroma of a female's orange throat patch is also related to her clutch size, suggesting that chemical signals may reinforce the information communicated by visual ornamentation in this species which would support the "backup signals" hypothesis for multiple signals.

Skin lipids of the striped plateau lizard ( Sceloporus virgatus) correlate with female receptivity and reproductive quality alongside visual ornaments

NASA Astrophysics Data System (ADS)

Goldberg, Jay K.; Wallace, Alisa K.; Weiss, Stacey L.

2017-10-01

Sex pheromones can perform a variety of functions ranging from revealing the location of suitable mates to being honest signals of mate quality, and they are used in the mate selection process by many species of reptile. In this study, we determined whether the skin lipids of female striped plateau lizards ( Sceloporus virgatus) can predict the reproductive quality of females, thereby having the potential to serve as pheromones. Using gas chromatography/mass spectrometry, we identified 17 compounds present in skin lipids of female lizards. Using principal component analysis to compare the skin lipid profile of receptive and non-receptive females, we determined that an uncharacterized compound may allow for chemical identification of receptive mates. We also compared extracted principal components to measures of female fitness and reproductive qualities and found that the level of two 18 carbon fatty acids present in a female's skin lipids may indicate her clutch size. Finally, we compared the information content of the skin lipids to that of female-specific color ornaments to assess whether chemical and visual cues transmit different information or not. We found that the chroma of a female's orange throat patch is also related to her clutch size, suggesting that chemical signals may reinforce the information communicated by visual ornamentation in this species which would support the "backup signals" hypothesis for multiple signals.

Linear Quantitative Profiling Method Fast Monitors Alkaloids of Sophora Flavescens That Was Verified by Tri-Marker Analyses

PubMed Central

Hou, Zhifei; Sun, Guoxiang; Guo, Yong

2016-01-01

The present study demonstrated the use of the Linear Quantitative Profiling Method (LQPM) to evaluate the quality of Alkaloids of Sophora flavescens (ASF) based on chromatographic fingerprints in an accurate, economical and fast way. Both linear qualitative and quantitative similarities were calculated in order to monitor the consistency of the samples. The results indicate that the linear qualitative similarity (LQLS) is not sufficiently discriminating due to the predominant presence of three alkaloid compounds (matrine, sophoridine and oxymatrine) in the test samples; however, the linear quantitative similarity (LQTS) was shown to be able to obviously identify the samples based on the difference in the quantitative content of all the chemical components. In addition, the fingerprint analysis was also supported by the quantitative analysis of three marker compounds. The LQTS was found to be highly correlated to the contents of the marker compounds, indicating that quantitative analysis of the marker compounds may be substituted with the LQPM based on the chromatographic fingerprints for the purpose of quantifying all chemicals of a complex sample system. Furthermore, once reference fingerprint (RFP) developed from a standard preparation in an immediate detection way and the composition similarities calculated out, LQPM could employ the classical mathematical model to effectively quantify the multiple components of ASF samples without any chemical standard. PMID:27529425

Dentin Biomodification: Strategies, Renewable Resources and Clinical Applications

PubMed Central

Bedran-Russo, Ana K.; Pauli, Guido F.; Chen, Shao-Nong; McAlpine, James; Castellan, Carina S.; Phansalkar, Rasika S; Aguiar, Thaiane R.; Vidal, Cristina M.P.; Napotilano, José; Nam, Joo-Won; Leme, Ariene A.

2014-01-01

Objectives The biomodification of dentin is a biomimetic approach, mediated by bioactive agents, to enhance and reinforce the dentin by locally altering the biochemistry and biomechanical properties. This review provides an overview of key dentin matrix components, targeting effects of biomodification strategies, the chemistry of renewable natural sources, and current research on their potential clinical applications. Methods The PubMed database and collected literature were used as a resource for peer-reviewed articles to highlight the topics of dentin hierarchical structure, biomodification agents, and laboratorial investigations of their clinical applications. In addition, new data is presented on laboratorial methods for the standardization of proanthocyanidin-rich preparations as a renewable source of plant-derived biomodification agents. Results Biomodification agents can be categorized as physical methods and chemical agents. Synthetic and naturally occurring chemical strategies present distinctive mechanism of interaction with the tissue. Initially thought to be driven only by inter- or intra-molecular collagen induced non-enzymatic collagen cross-linking, multiple interactions with other dentin components are fundamental for the long-term biomechanics and biostability of the tissue. Oligomeric proanthocyanidins show promising bioactivity, and their chemical complexity requires systematic evaluation of the active compounds to produce a fully standardized intervention material from renewable resource, prior to their detailed clinical evaluation. Significance Understanding the hierarchical structure of dentin and the targeting effect of the bioactive compounds will establish their use in both dentin-biomaterials interface and caries management. PMID:24309436

Male bladder cancer risk and occupational exposure according to a job-exposure matrix-a case-control study in British Columbia, Canada.

PubMed

Richardson, Kathryn; Band, Pierre R; Astrakianakis, George; Le, Nhu D

2007-12-01

The authors investigated the risk of bladder cancer in association with exposure to over 12 000 occupational chemical agents, complex mixtures, and other substances (hereafter referred to as chemical agents). Adult males diagnosed with cancer between 1983 and 1990 in British Columbia, Canada, were surveyed. Detailed occupational histories and confounding information was provided by a self-administered questionnaire. Cancer controls were matched to bladder cancer cases, resulting in 1062 cases and 8057 controls for the analysis. An extensive United-States-based job-exposure matrix was applied to estimate cumulative exposure to occupational chemical agents. Odds ratios for bladder cancer due to exposure to chemical agents were estimated via conditional logistic regression analyses, adjusted for important confounders. A significantly (P<0.05) increased risk was detected for ever exposure to 635 chemical agents, and 341 chemical agents exhibited a significantly increasing dose-response relationship. Adjustment for multiple comparisons resulted in a subset of 29 chemical agents that continued to show significant results. A principal components analysis classified these 29 chemical agents into five independent groups, distinguished mainly by job. Exposures to these chemical agents were largely due to employment in the logging and construction industries and occupations involving motor vehicles. Consistent results were observed for bladder carcinogens reported in the literature. This study suggests that several specific chemical agents were significantly associated with the risk of bladder cancer. The chemical agents were mainly derivatives or combustion products of fossil fuels. The results corroborate important findings from the literature and document a risk for specific chemical agents not previously reported.

Real-space analysis of radiation-induced specific changes with independent component analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borek, Dominika; Bromberg, Raquel; Hattne, Johan

A method of analysis is presented that allows for the separation of specific radiation-induced changes into distinct components in real space. The method relies on independent component analysis (ICA) and can be effectively applied to electron density maps and other types of maps, provided that they can be represented as sets of numbers on a grid. Here, for glucose isomerase crystals, ICA was used in a proof-of-concept analysis to separate temperature-dependent and temperature-independent components of specific radiation-induced changes for data sets acquired from multiple crystals across multiple temperatures. ICA identified two components, with the temperature-independent component being responsible for themore » majority of specific radiation-induced changes at temperatures below 130 K. The patterns of specific temperature-independent radiation-induced changes suggest a contribution from the tunnelling of electron holes as a possible explanation. In the second case, where a group of 22 data sets was collected on a single thaumatin crystal, ICA was used in another type of analysis to separate specific radiation-induced effects happening on different exposure-level scales. Here, ICA identified two components of specific radiation-induced changes that likely result from radiation-induced chemical reactions progressing with different rates at different locations in the structure. In addition, ICA unexpectedly identified the radiation-damage state corresponding to reduced disulfide bridges rather than the zero-dose extrapolated state as the highest contrast structure. The application of ICA to the analysis of specific radiation-induced changes in real space and the data pre-processing for ICA that relies on singular value decomposition, which was used previously in data space to validate a two-component physical model of X-ray radiation-induced changes, are discussed in detail. This work lays a foundation for a better understanding of protein-specific radiation chemistries and provides a framework for analysing effects of specific radiation damage in crystallographic and cryo-EM experiments.« less

Estimating the return-on-investment from changes in employee health risks on the Dow Chemical Company's health care costs.

PubMed

Goetzel, Ron Z; Ozminkowski, Ronald J; Baase, Catherine M; Billotti, Gary M

2005-08-01

We sought to estimate the impact of corporate health-management and risk-reduction programs for The Dow Chemical Company by using a prospective return-on-investment (ROI) model. The risk and expenditure estimates were derived from multiple regression analyses showing relationships between worker demographics, health risks, and medical expenditures. A "break-even" scenario would require Dow to reduce each of 10 population health risks by 0.17% points per year over the course of 10 years. More successful efforts at reducing health risks in the population would produce a more significant ROI for the company. Findings from this study were incorporated into other components of a business case for health and productivity management, and these supported continued investments in health improvement programs designed to achieve risk reduction and cost savings.

THz-wave parametric source and its imaging applications

NASA Astrophysics Data System (ADS)

Kawase, Kodo

2004-08-01

Widely tunable coherent terahertz (THz) wave generation has been demonstrated based on the parametric oscillation using MgO doped LiNbO3 crystal pumped by a Q-switched Nd:YAG laser. This method exhibits multiple advantages like wide tunability, coherency and compactness of its system. We have developed a novel basic technology for terahertz (THz) imaging, which allows detection and identification of chemicals by introducing the component spatial pattern analysis. The spatial distributions of the chemicals were obtained from terahertz multispectral transillumination images, using absorption spectra previously measured with a widely tunable THz-wave parametric oscillator. Further we have applied this technique to the detection and identification of illicit drugs concealed in envelopes. The samples we used were methamphetamine and MDMA, two of the most widely consumed illegal drugs in Japan, and aspirin as a reference.

The application of computer modeling to health effect research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, R.S.H.

1996-12-31

In the United States, estimates show that more than 30,000 hazardous waste disposal sites exist, not including military installations, U.S. Department of Energy nuclear facilities, and hundreds and thousands of underground fuel storage tanks; these sites undoubtedly have their own respective hazardous waste chemical problems. When so many sites contain hazardous chemicals, how does one study the health effects of the chemicals at these sites? There could be many different answers, but none would be perfect. For an area as complex and difficult as the study of chemical mixtures associated with hazardous waste disposal sites, there are no perfect approachesmore » and protocols. Human exposure to chemicals, be it environmental or occupational, is rarely, if ever, limited to a single chemical. Therefore, it is essential that we consider multiple chemical effects and interactions in our risk assessment process. Systematic toxicity testing of chemical mixtures in the environment or workplace that uses conventional toxicology methodologies is highly impractical because of the immense numbers of mixtures involved. For example, about 600,000 chemicals are being used in our society. Just considering binary chemical mixtures, this means that there could be 600,000 x 599,999/2 = 359,999,400,000 pairs of chemicals. Assuming that only one in a million of these pairs of chemicals acts synergistically or has other toxicologic interactions, there would still be 359,999 binary chemical mixtures possessing toxicologic interactions. Moreover, toxicologic interactions undoubtedly exist among chemical mixtures with three or more component chemicals; the number of possible combinations for these latter mixtures is almost infinite. These are astronomically large numbers with respect to systematic toxicity testing. 22 refs., 5 figs., 1 tab.« less

Identification of chemical components in Baidianling Capsule based on gas chromatography-mass spectrometry and high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry.

PubMed

Wu, Wenying; Chen, Yu; Wang, Binjie; Sun, Xiaoyang; Guo, Ping; Chen, Xiaohui

2017-08-01

Baidianling Capsule, which is made from 16 Chinese herbs, has been widely used for treating vitiligo clinically. In this study, the sensitive and rapid method has been developed for the analysis of chemical components in Baidianling Capsule by gas chromatography-mass spectrometry in combination with retention indices and high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry. Firstly, a total of 110 potential volatile compounds obtained from different extraction procedures including alkanes, alkenes, alkynes, ketones, ethers, aldehydes, alcohols, phenols, organic acids, esters, furans, pyrrole, acid amides, heterocycles, and oxides were detected from Baidianling Capsule by gas chromatography-mass spectrometry, of which 75 were identified by mass spectrometry in combination with the retention index. Then, a total of 124 components were tentatively identified by high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry. Fifteen constituents from Baidianling Capsule were accurately identified by comparing the retention times with those of reference compounds, others were identified by comparing the retention times and mass spectrometry data, as well as retrieving the reference literature. This study provides a practical strategy for rapidly screening and identifying the multiple constituents of a complex traditional Chinese medicine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microlithography and resist technology information at your fingertips via SciFinder

NASA Astrophysics Data System (ADS)

Konuk, Rengin; Macko, John R.; Staggenborg, Lisa

1997-07-01

Finding and retrieving the information you need about microlithography and resist technology in a timely fashion can make or break your competitive edge in today's business environment. Chemical Abstracts Service (CAS) provides the most complete and comprehensive database of the chemical literature in the CAplus, REGISTRY, and CASREACT files including 13 million document references, 15 million substance records and over 1.2 million reactions. This includes comprehensive coverage of positive and negative resist formulations and processing, photoacid generation, silylation, single and multilayer resist systems, photomasks, dry and wet etching, photolithography, electron-beam, ion-beam and x-ray lithography technologies and process control, optical tools, exposure systems, radiation sources and steppers. Journal articles, conference proceedings and patents related to microlithography and resist technology are analyzed and indexed by scientific information analysts with strong technical background in these areas. The full CAS database, which is updated weekly with new information, is now available at your desktop, via a convenient, user-friendly tool called 'SciFinder.' Author, subject and chemical substance searching is simplified by SciFinder's smart search features. Chemical substances can be searched by chemical structure, chemical name, CAS registry number or molecular formula. Drawing chemical structures in SciFinder is easy and does not require compliance with CA conventions. Built-in intelligence of SciFinder enables users to retrieve substances with multiple components, tautomeric forms and salts.

Dispelling urban myths about default uncertainty factors in chemical risk assessment – sufficient protection against mixture effects?

PubMed Central

2013-01-01

Assessing the detrimental health effects of chemicals requires the extrapolation of experimental data in animals to human populations. This is achieved by applying a default uncertainty factor of 100 to doses not found to be associated with observable effects in laboratory animals. It is commonly assumed that the toxicokinetic and toxicodynamic sub-components of this default uncertainty factor represent worst-case scenarios and that the multiplication of those components yields conservative estimates of safe levels for humans. It is sometimes claimed that this conservatism also offers adequate protection from mixture effects. By analysing the evolution of uncertainty factors from a historical perspective, we expose that the default factor and its sub-components are intended to represent adequate rather than worst-case scenarios. The intention of using assessment factors for mixture effects was abandoned thirty years ago. It is also often ignored that the conservatism (or otherwise) of uncertainty factors can only be considered in relation to a defined level of protection. A protection equivalent to an effect magnitude of 0.001-0.0001% over background incidence is generally considered acceptable. However, it is impossible to say whether this level of protection is in fact realised with the tolerable doses that are derived by employing uncertainty factors. Accordingly, it is difficult to assess whether uncertainty factors overestimate or underestimate the sensitivity differences in human populations. It is also often not appreciated that the outcome of probabilistic approaches to the multiplication of sub-factors is dependent on the choice of probability distributions. Therefore, the idea that default uncertainty factors are overly conservative worst-case scenarios which can account both for the lack of statistical power in animal experiments and protect against potential mixture effects is ill-founded. We contend that precautionary regulation should provide an incentive to generate better data and recommend adopting a pragmatic, but scientifically better founded approach to mixture risk assessment. PMID:23816180

Dispelling urban myths about default uncertainty factors in chemical risk assessment--sufficient protection against mixture effects?

PubMed

Martin, Olwenn V; Martin, Scholze; Kortenkamp, Andreas

2013-07-01

Assessing the detrimental health effects of chemicals requires the extrapolation of experimental data in animals to human populations. This is achieved by applying a default uncertainty factor of 100 to doses not found to be associated with observable effects in laboratory animals. It is commonly assumed that the toxicokinetic and toxicodynamic sub-components of this default uncertainty factor represent worst-case scenarios and that the multiplication of those components yields conservative estimates of safe levels for humans. It is sometimes claimed that this conservatism also offers adequate protection from mixture effects. By analysing the evolution of uncertainty factors from a historical perspective, we expose that the default factor and its sub-components are intended to represent adequate rather than worst-case scenarios. The intention of using assessment factors for mixture effects was abandoned thirty years ago. It is also often ignored that the conservatism (or otherwise) of uncertainty factors can only be considered in relation to a defined level of protection. A protection equivalent to an effect magnitude of 0.001-0.0001% over background incidence is generally considered acceptable. However, it is impossible to say whether this level of protection is in fact realised with the tolerable doses that are derived by employing uncertainty factors. Accordingly, it is difficult to assess whether uncertainty factors overestimate or underestimate the sensitivity differences in human populations. It is also often not appreciated that the outcome of probabilistic approaches to the multiplication of sub-factors is dependent on the choice of probability distributions. Therefore, the idea that default uncertainty factors are overly conservative worst-case scenarios which can account both for the lack of statistical power in animal experiments and protect against potential mixture effects is ill-founded. We contend that precautionary regulation should provide an incentive to generate better data and recommend adopting a pragmatic, but scientifically better founded approach to mixture risk assessment.

3D-liquid chromatography as a complex mixture characterization tool for knowledge-based downstream process development.

PubMed

Hanke, Alexander T; Tsintavi, Eleni; Ramirez Vazquez, Maria Del Pilar; van der Wielen, Luuk A M; Verhaert, Peter D E M; Eppink, Michel H M; van de Sandt, Emile J A X; Ottens, Marcel

2016-09-01

Knowledge-based development of chromatographic separation processes requires efficient techniques to determine the physicochemical properties of the product and the impurities to be removed. These characterization techniques are usually divided into approaches that determine molecular properties, such as charge, hydrophobicity and size, or molecular interactions with auxiliary materials, commonly in the form of adsorption isotherms. In this study we demonstrate the application of a three-dimensional liquid chromatography approach to a clarified cell homogenate containing a therapeutic enzyme. Each separation dimension determines a molecular property relevant to the chromatographic behavior of each component. Matching of the peaks across the different separation dimensions and against a high-resolution reference chromatogram allows to assign the determined parameters to pseudo-components, allowing to determine the most promising technique for the removal of each impurity. More detailed process design using mechanistic models requires isotherm parameters. For this purpose, the second dimension consists of multiple linear gradient separations on columns in a high-throughput screening compatible format, that allow regression of isotherm parameters with an average standard error of 8%. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1283-1291, 2016. © 2016 American Institute of Chemical Engineers.

Quantitative interpretations of Visible-NIR reflectance spectra of blood.

PubMed

Serebrennikova, Yulia M; Smith, Jennifer M; Huffman, Debra E; Leparc, German F; García-Rubio, Luis H

2008-10-27

This paper illustrates the implementation of a new theoretical model for rapid quantitative analysis of the Vis-NIR diffuse reflectance spectra of blood cultures. This new model is based on the photon diffusion theory and Mie scattering theory that have been formulated to account for multiple scattering populations and absorptive components. This study stresses the significance of the thorough solution of the scattering and absorption problem in order to accurately resolve for optically relevant parameters of blood culture components. With advantages of being calibration-free and computationally fast, the new model has two basic requirements. First, wavelength-dependent refractive indices of the basic chemical constituents of blood culture components are needed. Second, multi-wavelength measurements or at least the measurements of characteristic wavelengths equal to the degrees of freedom, i.e. number of optically relevant parameters, of blood culture system are required. The blood culture analysis model was tested with a large number of diffuse reflectance spectra of blood culture samples characterized by an extensive range of the relevant parameters.

Parenting training for women in residential substance abuse treatment. Results of a demonstration project.

PubMed

Camp, J M; Finkelstein, N

1997-01-01

This paper presents findings on the impact of implementing a parenting component in two urban residential treatment programs in Massachusetts for pregnant and parenting chemically-dependent women. The parenting component consisted of multiple services for both women and their infants while they were in residential treatment as well as aftercare services after discharge from treatment. Findings presented focus on: (a) the characteristics of the 170 pregnant and parenting women who participated in the parenting component during its 48 months of implementation; (b) changes in the parenting skills and self-esteem of women who completed parenting training; (c) the quality of mother-child interaction; and (d) the participants' perceptions about the impact of the parenting training. Women in both programs made dramatic improvements in self-esteem and experienced significant gains in parenting knowledge and attitudes. The participants were also overwhelmingly positive about the impact of the parenting training on their lives. Study findings underline the importance of parenting services for pregnant and parenting women in residential substance abuse treatment.

Identifying Nanoscale Structure-Function Relationships Using Multimodal Atomic Force Microscopy, Dimensionality Reduction, and Regression Techniques.

PubMed

Kong, Jessica; Giridharagopal, Rajiv; Harrison, Jeffrey S; Ginger, David S

2018-05-31

Correlating nanoscale chemical specificity with operational physics is a long-standing goal of functional scanning probe microscopy (SPM). We employ a data analytic approach combining multiple microscopy modes, using compositional information in infrared vibrational excitation maps acquired via photoinduced force microscopy (PiFM) with electrical information from conductive atomic force microscopy. We study a model polymer blend comprising insulating poly(methyl methacrylate) (PMMA) and semiconducting poly(3-hexylthiophene) (P3HT). We show that PiFM spectra are different from FTIR spectra, but can still be used to identify local composition. We use principal component analysis to extract statistically significant principal components and principal component regression to predict local current and identify local polymer composition. In doing so, we observe evidence of semiconducting P3HT within PMMA aggregates. These methods are generalizable to correlated SPM data and provide a meaningful technique for extracting complex compositional information that are impossible to measure from any one technique.

Neuropharmacological Potential of Gastrodia elata Blume and Its Components

PubMed Central

Jang, Jung-Hee; Son, Yeonghoon; Kang, Seong Soo; Bae, Chun-Sik; Kim, Jong-Choon; Kim, Sung-Ho; Shin, Taekyun; Moon, Changjong

2015-01-01

Research has been conducted in various fields in an attempt to develop new therapeutic agents for incurable neurodegenerative diseases. Gastrodia elata Blume (GE), a traditional herbal medicine, has been used in neurological disorders as an anticonvulsant, analgesic, and sedative medication. Several neurodegenerative models are characterized by oxidative stress and inflammation in the brain, which lead to cell death via multiple extracellular and intracellular signaling pathways. The blockade of certain signaling cascades may represent a compensatory therapy for injured brain tissue. Antioxidative and anti-inflammatory compounds isolated from natural resources have been investigated, as have various synthetic chemicals. Specifically, GE rhizome extract and its components have been shown to protect neuronal cells and recover brain function in various preclinical brain injury models by inhibiting oxidative stress and inflammatory responses. The present review discusses the neuroprotective potential of GE and its components and the related mechanisms; we also provide possible preventive and therapeutic strategies for neurodegenerative disorders using herbal resources. PMID:26543487

What Is Chemical Stoichiometry?

ERIC Educational Resources Information Center

Smith, William R.; Missen, Ronald W.

1979-01-01

Chemical stoichiometry is discussed free from kinetic or thermodynamic considerations. The means for determining the following are presented: the number of stoichiometric degrees of freedom, the number of components, a permissible set of chemical equations, and a permissible set of components, for a closed system undergoing chemical reaction.…

DIRECT DETERMINATION OF THE HF/H{sub 2} ABUNDANCE RATIO IN INTERSTELLAR GAS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Indriolo, Nick; Neufeld, D. A.; Seifahrt, A.

2013-02-20

We report the first detection of the v = 1-0, R(0) ro-vibrational transition of HF at 2.499385 {mu}m arising from interstellar gas. The line is seen in absorption toward three background sources-HD 154368, Elias 29, and AFGL 2136 IRS 1-all of which have reported H{sub 2} column densities determined from observations of H{sub 2}. This allows for the first direct determination of the HF/H{sub 2} abundance ratio. We find values of N(HF)/N(H{sub 2}) = 1.15 Multiplication-Sign 10{sup -8} and 0.69 Multiplication-Sign 10{sup -8} for HD 154368 and Elias 29, respectively. The sight line toward AFGL 2136 IRS 1 also showsmore » absorption from the v = 1-0, R(1) transition of HF, indicating warm, dense (n {sub H} {approx}> 10{sup 9} cm{sup -3}) gas, likely very close to the central protostar. Ascribing portions of the HF absorption to warm and cold gas, we find N(HF)/N(H{sub 2}) = (1.7-2.9) Multiplication-Sign 10{sup -8} and (0.33-0.58) Multiplication-Sign 10{sup -8} for the two components, respectively. Except for the warm component toward AFGL 2136 IRS 1, all observed HF/H{sub 2} ratios are well below N(HF)/N(H{sub 2}) = 3.6 Multiplication-Sign 10{sup -8}, the value predicted if nearly all gas phase fluorine is in the form of HF. Models of fluorine chemistry that account for depletion onto grains are able to reproduce the results toward HD 154368, but not in the cold, dense gas toward AFGL 2136 IRS 1 and Elias 29. Most likely, some combinations of simplifying assumptions made in the chemical models are responsible for these discrepancies.« less

[Analysis of chemical constituents of volatile components from Jia Ga Song Tang by GC-MS].

PubMed

Tan, Qing-long; Xiong, Tian-qin; Liao, Jia-yi; Yang, Tao; Zhao, Yu-min; Lin, Xi; Zhang, Cui-xian

2014-10-01

To analyze the chemical components of volatile components from Jia Ga Song Tang. The volatile oils were extracted by water steam distillation. The chemical components of essential oil were analyzed by GC-MS and quantitatively determined by a normalization method. 103 components were separated and 87 components were identified in the volatile oil of Zingiberis Rhizoma. 58 components were separated and 38 components were identified in the volatile oil of Myristicae Semen. 49 components were separated and 38 components were identified in the volatile oil of Amomi Rotundus Fructus. 89 components were separated and 63 components were identified in the volatile oil of Jia Ga Song Tang. Eucalyptol, β-phellandrene and other terpenes were the main compounds in the volatile oil of Jia Ga Song Tang. Changes in the kinds and content of volatile components can provide evidences for scientific and rational compatibility for Jia Ga Song Tang.

Analysis on the Alpinia katsumadai components of Zingiberaceae plants and their functions on myeloma resistance.

PubMed

Wang, Jue; Qiu, Rubiao; Yuan, Lianjing; Meng, Fei; Tang, Qian

2015-05-01

Generally speaking, zingiberaceae plants with sweet fragrance are commonly seen as perennial herbs that contains numerous well-known crude drugs and fragrant plants like Amomum villosum, Amomumtsao-ko, Ginger, Alpinia katsumadai and Radix curcumae, which are widely used in daily life. This paper analyzed chemical components of Alpinia katsumadai of zingiberaceae and applied several laminar analysis to further develop its active ingredients, aiming to make sure its function on tumor assistance. Actually, cardamomin contained in Alpinia katsumadai has been recorded to act notably in myeloma resistance, which was verified by cholecystokinin-octopeptide (CCK-8) in this paper. Cardamom in is proved to have multiple anti-myeloma effects, including myeloma cell activity and proliferation control, cell cycle retardant and apoptosis induction, which indicates its value in the field of medical pharmacy.

Liquid zone seal

DOEpatents

Klebanoff, Leonard E.

2001-01-01

A seal assembly that provides a means for establishing multiple pressure zones within a system. The seal assembly combines a plate extending from the inner wall of a housing or inner enclosure that intersects with and is immersed in the fluid contained in a well formed in a tray contained within the enclosure. The fluid is a low vapor pressure oil, chemically inert and oxidation resistant. The use of a fluid as the sealing component provides a seal that is self-healing and mechanically robust not subject to normal mechanical wear, breakage, and formation of cracks or pinholes and decouples external mechanical vibrations from internal structural members.

Venus Global Reference Atmospheric Model

NASA Technical Reports Server (NTRS)

Justh, Hilary L.

2017-01-01

Venus Global Reference Atmospheric Model (Venus-GRAM) is an engineering-level atmospheric model developed by MSFC that is widely used for diverse mission applications including: Systems design; Performance analysis; Operations planning for aerobraking, Entry, Descent and Landing, and aerocapture; Is not a forecast model; Outputs include density, temperature, pressure, wind components, and chemical composition; Provides dispersions of thermodynamic parameters, winds, and density; Optional trajectory and auxiliary profile input files Has been used in multiple studies and proposals including NASA Engineering and Safety Center (NESC) Autonomous Aerobraking and various Discovery proposals; Released in 2005; Available at: https://software.nasa.gov/software/MFS-32314-1.

Detecting multiple adulterants in dry milk using Raman chemical imaging

USDA-ARS?s Scientific Manuscript database

A Raman chemical imaging method was developed for detecting the presence of multiple chemical adulterants in dry milk powder. Four chemicals (ammonium sulfate, dicyandiamide, melamine, and urea) were added in equal concentrations, between 0.1% and 5.0%, to nonfat dry milk. An area of 25×25 mm2 for e...

The chemical component dictionary: complete descriptions of constituent molecules in experimentally determined 3D macromolecules in the Protein Data Bank

PubMed Central

Westbrook, John D.; Shao, Chenghua; Feng, Zukang; Zhuravleva, Marina; Velankar, Sameer; Young, Jasmine

2015-01-01

Summary: The Chemical Component Dictionary (CCD) is a chemical reference data resource that describes all residue and small molecule components found in Protein Data Bank (PDB) entries. The CCD contains detailed chemical descriptions for standard and modified amino acids/nucleotides, small molecule ligands and solvent molecules. Each chemical definition includes descriptions of chemical properties such as stereochemical assignments, chemical descriptors, systematic chemical names and idealized coordinates. The content, preparation, validation and distribution of this CCD chemical reference dataset are described. Availability and implementation: The CCD is updated regularly in conjunction with the scheduled weekly release of new PDB structure data. The CCD and amino acid variant reference datasets are hosted in the public PDB ftp repository at ftp://ftp.wwpdb.org/pub/pdb/data/monomers/components.cif.gz, ftp://ftp.wwpdb.org/pub/pdb/data/monomers/aa-variants-v1.cif.gz, and its mirror sites, and can be accessed from http://wwpdb.org. Contact: jwest@rcsb.rutgers.edu. Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25540181

Symptom profile of multiple chemical sensitivity in actual life.

PubMed

Saito, Mariko; Kumano, Hiroaki; Yoshiuchi, Kazuhiro; Kokubo, Naomi; Ohashi, Kyoko; Yamamoto, Yoshiharu; Shinohara, Naohide; Yanagisawa, Yukio; Sakabe, Kou; Miyata, Mikio; Ishikawa, Satoshi; Kuboki, Tomifusa

2005-01-01

This study was conducted to confirm the definition of multiple chemical sensitivity (MCS) in actual life: that multiple symptoms are provoked in multiple organs by exposure to, and ameliorated by avoidance of, multiple chemicals at low levels. We used the Ecological Momentary Assessment to monitor everyday symptoms and the active sampling and passive sampling methods to measure environmental chemical exposure. Eighteen patients with MCS, diagnosed according to the 1999 consensus criteria, and 12 healthy controls participated in this study. Fourteen patients and 12 controls underwent 1-week measurement of physical and psychologic symptoms and of the levels of exposure to various chemicals. Linear mixed models were used to test the hypotheses regarding the symptom profile of MCS patients. Some causative chemicals were detected in 11 of 14 MCS patients. Two other patients did not report any hypersensitivity episodes, whereas passive sampling showed far less exposure to chemicals than control subjects. Another subject reported episodic symptoms but was excluded from the following analyses because no possible chemical was detected. Eleven of the 17 physical symptoms and all four mood subscales examined were significantly aggravated in the interview based on "patient-initiated symptom prompts." On the other hand, there were no differences in physical symptoms or mood subscales between MCS patients and control subjects in the interview based on "random prompts." MCS patients do not have either somatic or psychologic symptoms under chemical-free conditions, and symptoms may be provoked only when exposed to chemicals.

Use of Natural Products as Chemical Library for Drug Discovery and Network Pharmacology

PubMed Central

Gu, Jiangyong; Gui, Yuanshen; Chen, Lirong; Yuan, Gu; Lu, Hui-Zhe; Xu, Xiaojie

2013-01-01

Background Natural products have been an important source of lead compounds for drug discovery. How to find and evaluate bioactive natural products is critical to the achievement of drug/lead discovery from natural products. Methodology We collected 19,7201 natural products structures, reported biological activities and virtual screening results. Principal component analysis was employed to explore the chemical space, and we found that there was a large portion of overlap between natural products and FDA-approved drugs in the chemical space, which indicated that natural products had large quantity of potential lead compounds. We also explored the network properties of natural product-target networks and found that polypharmacology was greatly enriched to those compounds with large degree and high betweenness centrality. In order to make up for a lack of experimental data, high throughput virtual screening was employed. All natural products were docked to 332 target proteins of FDA-approved drugs. The most potential natural products for drug discovery and their indications were predicted based on a docking score-weighted prediction model. Conclusions Analysis of molecular descriptors, distribution in chemical space and biological activities of natural products was conducted in this article. Natural products have vast chemical diversity, good drug-like properties and can interact with multiple cellular target proteins. PMID:23638153

Multiple-component covalent organic frameworks

PubMed Central

Huang, Ning; Zhai, Lipeng; Coupry, Damien E.; Addicoat, Matthew A.; Okushita, Keiko; Nishimura, Katsuyuki; Heine, Thomas; Jiang, Donglin

2016-01-01

Covalent organic frameworks are a class of crystalline porous polymers that integrate molecular building blocks into periodic structures and are usually synthesized using two-component [1+1] condensation systems comprised of one knot and one linker. Here we report a general strategy based on multiple-component [1+2] and [1+3] condensation systems that enable the use of one knot and two or three linker units for the synthesis of hexagonal and tetragonal multiple-component covalent organic frameworks. Unlike two-component systems, multiple-component covalent organic frameworks feature asymmetric tiling of organic units into anisotropic skeletons and unusually shaped pores. This strategy not only expands the structural complexity of skeletons and pores but also greatly enhances their structural diversity. This synthetic platform is also widely applicable to multiple-component electron donor–acceptor systems, which lead to electronic properties that are not simply linear summations of those of the conventional [1+1] counterparts. PMID:27460607

Multiple-component covalent organic frameworks

NASA Astrophysics Data System (ADS)

Huang, Ning; Zhai, Lipeng; Coupry, Damien E.; Addicoat, Matthew A.; Okushita, Keiko; Nishimura, Katsuyuki; Heine, Thomas; Jiang, Donglin

2016-07-01

Covalent organic frameworks are a class of crystalline porous polymers that integrate molecular building blocks into periodic structures and are usually synthesized using two-component [1+1] condensation systems comprised of one knot and one linker. Here we report a general strategy based on multiple-component [1+2] and [1+3] condensation systems that enable the use of one knot and two or three linker units for the synthesis of hexagonal and tetragonal multiple-component covalent organic frameworks. Unlike two-component systems, multiple-component covalent organic frameworks feature asymmetric tiling of organic units into anisotropic skeletons and unusually shaped pores. This strategy not only expands the structural complexity of skeletons and pores but also greatly enhances their structural diversity. This synthetic platform is also widely applicable to multiple-component electron donor-acceptor systems, which lead to electronic properties that are not simply linear summations of those of the conventional [1+1] counterparts.

Research and Guidance on Drinking Water Contaminant Mixtures

EPA Science Inventory

Accurate assessment of potential human health risk(s) from multiple-route exposures to multiple chemicals in drinking water is needed because of widespread daily exposure to this complex mixture. Hundreds of chemicals have been identified in drinking water with the mix of chemic...

Preform spar cap for a wind turbine rotor blade

DOEpatents

Livingston, Jamie T [Simpsonville, SC; Driver, Howard D [Greer, SC; van Breugel, Sjef [Enschede, NL; Jenkins, Thomas B [Cantonment, FL; Bakhuis, Jan Willem [Nijverdal, NL; Billen, Andrew J [Daarlerveen, NL; Riahi, Amir [Pensacola, FL

2011-07-12

A spar cap for a wind turbine rotor blade. The spar cap may include multiple preform components. The multiple preform components may be planar sheets having a swept shape with a first end and a second end. The multiple preform components may be joined by mating the first end of a first preform component to the second end of a next preform component, forming the spar cap.

Fluorine Variations in the Globular Cluster NGC 6656 (M22): Implications for Internal Enrichment Timescales

NASA Astrophysics Data System (ADS)

D'Orazi, Valentina; Lucatello, Sara; Lugaro, Maria; Gratton, Raffaele G.; Angelou, George; Bragaglia, Angela; Carretta, Eugenio; Alves-Brito, Alan; Ivans, Inese I.; Masseron, Thomas; Mucciarelli, Alessio

2013-01-01

Observed chemical (anti)correlations in proton-capture elements among globular cluster stars are presently recognized as the signature of self-enrichment from now extinct, previous generations of stars. This defines the multiple population scenario. Since fluorine is also affected by proton captures, determining its abundance in globular clusters provides new and complementary clues regarding the nature of these previous generations and supplies strong observational constraints to the chemical enrichment timescales. In this paper, we present our results on near-infrared CRIRES spectroscopic observations of six cool giant stars in NGC 6656 (M22): the main objective is to derive the F content and its internal variation in this peculiar cluster, which exhibits significant changes in both light- and heavy-element abundances. Across our sample, we detected F variations beyond the measurement uncertainties and found that the F abundances are positively correlated with O and anticorrelated with Na, as expected according to the multiple population framework. Furthermore, our observations reveal an increase in the F content between the two different sub-groups, s-process rich and s-process poor, hosted within M22. The comparison with theoretical models suggests that asymptotic giant stars with masses between 4 and 5 M ⊙ are responsible for the observed chemical pattern, confirming evidence from previous works: the difference in age between the two sub-components in M22 must be not larger than a few hundred Myr. Based on observations taken with ESO telescopes under program 087.0319(A).

Three-dimensional nanoscale molecular imaging by extreme ultraviolet laser ablation mass spectrometry

PubMed Central

Kuznetsov, Ilya; Filevich, Jorge; Dong, Feng; Woolston, Mark; Chao, Weilun; Anderson, Erik H.; Bernstein, Elliot R.; Crick, Dean C.; Rocca, Jorge J.; Menoni, Carmen S.

2015-01-01

Analytical probes capable of mapping molecular composition at the nanoscale are of critical importance to materials research, biology and medicine. Mass spectral imaging makes it possible to visualize the spatial organization of multiple molecular components at a sample's surface. However, it is challenging for mass spectral imaging to map molecular composition in three dimensions (3D) with submicron resolution. Here we describe a mass spectral imaging method that exploits the high 3D localization of absorbed extreme ultraviolet laser light and its fundamentally distinct interaction with matter to determine molecular composition from a volume as small as 50 zl in a single laser shot. Molecular imaging with a lateral resolution of 75 nm and a depth resolution of 20 nm is demonstrated. These results open opportunities to visualize chemical composition and chemical changes in 3D at the nanoscale. PMID:25903827

Accelerated oral nanomedicine discovery from miniaturized screening to clinical production exemplified by paediatric HIV nanotherapies

NASA Astrophysics Data System (ADS)

Giardiello, Marco; Liptrott, Neill J.; McDonald, Tom O.; Moss, Darren; Siccardi, Marco; Martin, Phil; Smith, Darren; Gurjar, Rohan; Rannard, Steve P.; Owen, Andrew

2016-10-01

Considerable scope exists to vary the physical and chemical properties of nanoparticles, with subsequent impact on biological interactions; however, no accelerated process to access large nanoparticle material space is currently available, hampering the development of new nanomedicines. In particular, no clinically available nanotherapies exist for HIV populations and conventional paediatric HIV medicines are poorly available; one current paediatric formulation utilizes high ethanol concentrations to solubilize lopinavir, a poorly soluble antiretroviral. Here we apply accelerated nanomedicine discovery to generate a potential aqueous paediatric HIV nanotherapy, with clinical translation and regulatory approval for human evaluation. Our rapid small-scale screening approach yields large libraries of solid drug nanoparticles (160 individual components) targeting oral dose. Screening uses 1 mg of drug compound per library member and iterative pharmacological and chemical evaluation establishes potential candidates for progression through to clinical manufacture. The wide applicability of our strategy has implications for multiple therapy development programmes.

ChemiRs: a web application for microRNAs and chemicals.

PubMed

Su, Emily Chia-Yu; Chen, Yu-Sing; Tien, Yun-Cheng; Liu, Jeff; Ho, Bing-Ching; Yu, Sung-Liang; Singh, Sher

2016-04-18

MicroRNAs (miRNAs) are about 22 nucleotides, non-coding RNAs that affect various cellular functions, and play a regulatory role in different organisms including human. Until now, more than 2500 mature miRNAs in human have been discovered and registered, but still lack of information or algorithms to reveal the relations among miRNAs, environmental chemicals and human health. Chemicals in environment affect our health and daily life, and some of them can lead to diseases by inferring biological pathways. We develop a creditable online web server, ChemiRs, for predicting interactions and relations among miRNAs, chemicals and pathways. The database not only compares gene lists affected by chemicals and miRNAs, but also incorporates curated pathways to identify possible interactions. Here, we manually retrieved associations of miRNAs and chemicals from biomedical literature. We developed an online system, ChemiRs, which contains miRNAs, diseases, Medical Subject Heading (MeSH) terms, chemicals, genes, pathways and PubMed IDs. We connected each miRNA to miRBase, and every current gene symbol to HUGO Gene Nomenclature Committee (HGNC) for genome annotation. Human pathway information is also provided from KEGG and REACTOME databases. Information about Gene Ontology (GO) is queried from GO Online SQL Environment (GOOSE). With a user-friendly interface, the web application is easy to use. Multiple query results can be easily integrated and exported as report documents in PDF format. Association analysis of miRNAs and chemicals can help us understand the pathogenesis of chemical components. ChemiRs is freely available for public use at http://omics.biol.ntnu.edu.tw/ChemiRs .

[Extraction and analysis of chemical components of essential oil in Thymus vulgaris of tissue culture].

PubMed

Li, Xiao-Dong; Yang, Li; Xu, Shi-Qian; Li, Jian-Guo; Cheng, Zhi-Hui; Dang, Jian-Zhang

2011-10-01

To extract the essential oils from the Seedlings, the Aseptic Seedlings and the Tissue Culture Seedlings of Thymus vulgaris and analyze their chemical components and the relative contents. The essential oils were extracted by steam distillation, the chemical components and the relative contents were identified and analyzed by gas chromatography-mass spectrometry (GC/MS) and peak area normalization method. The main chemical components of essential oil in these three samples had no significant difference, they all contained the main components of essential oil in Thymus vulgaris: Thymol, Carvacrol, o-Cymene, gamma-Terpinene, Caryophyllene et al. and only had a slight difference in the relative content. This study provides important theoretical foundation and data reference for further study on production of essential oil in thyme by tissue culture technology.

Polar Oxides without Inversion Symmetry through Vacancy and Chemical Order.

PubMed

Young, Joshua; Moon, Eun Ju; Mukherjee, Debangshu; Stone, Greg; Gopalan, Venkatraman; Alem, Nasim; May, Steven J; Rondinelli, James M

2017-02-22

One synthetic modality for materials discovery proceeds by forming mixtures of two or more compounds. In transition metal oxides (TMOs), chemical substitution often obeys Vegard's principle, and the resulting structure and properties of the derived phase follow from its components. A change in the assembly of the components into a digital nanostructure, however, can stabilize new polymorphs and properties not observed in the constituents. Here we formulate and demonstrate a crystal-chemistry design approach for realizing digital TMOs without inversion symmetry by combining two centrosymmetric compounds, utilizing periodic anion-vacancy order to generate multiple polyhedra that together with cation order produce a polar structure. We next apply this strategy to two brownmillerite-structured TMOs known to display centrosymmetric crystal structures in their bulk, Ca 2 Fe 2 O 5 and Sr 2 Fe 2 O 5 . We then realize epitaxial (SrFeO 2.5 ) 1 /(CaFeO 2.5 ) 1 thin film superlattices possessing both anion-vacancy order and Sr and Ca chemical order at the subnanometer scale, confirmed through synchrotron-based diffraction and aberration corrected electron microscopy. Through a detailed symmetry analysis and density functional theory calculations, we show that A-site cation ordering lifts inversion symmetry in the superlattice and produces a polar compound. Our results demonstrate how control of anion and cation order at the nanoscale can be utilized to produce acentric structures markedly different than their constituents and open a path toward novel structure-based property design.

Microbial Ecology in Vineyards

USDA-ARS?s Scientific Manuscript database

Soil health affects grapevine health, which, in turn, affects fruit quality. Soil health has chemical, physical, and biological components. The chemical components are the best understood, and there are relatively convenient methods to both evaluate and amend chemical soil fertility. The physical...

Molecular insight into atypical instability behavior of fixed-dose combination containing amlodipine besylate and losartan potassium.

PubMed

Handa, Tarun; Jhajra, Shalu; Bhagat, Shweta; Bharatam, P V; Chakraborti, Asit K; Singh, Saranjit

2017-03-20

Combination therapy with the use of fixed-dose combinations (FDCs) is evincing increasing interest of prescribers, manufacturers and even regulators, evidently due to the primary benefit of improved patient compliance. However, owing to potential of drug-drug interaction, FDCs require closer scrutiny with respect to their physical and chemical stability. Accordingly, the purpose of the present study was to explore stability behavior of a popular antihypertensive combination of amlodipine besylate (AML) and losartan potassium (LST). Physical mixtures of the two drugs and multiple marketed formulations were stored under accelerated conditions of temperature and humidity (40°C/75% RH) in a stability chamber and samples were withdrawn after 1 and 3 months. The physical changes were observed visibly, while chemical changes were monitored by HPLC employing a method that could separate the two drugs and all other components present. The combination revealed strong physical instability and also chemical degradation of AML in the presence of LST. Interestingly, three isomeric interaction products of AML were formed in the combination, which otherwise were reported in the literature to be generated on exposure of AML free base above its melting point. The same unusual products were even formed when multiple marketed FDCs were stored under accelerated conditions outside their storage packs. However, these were absent when AML alone was stored in the same studied conditions. Therefore, reasons for physical and chemical incompatibility and the mechanism of degradation of AML in the presence of LST were duly explored at the molecular level. The outcomes of the study are expected to help in development of stable FDCs of the two drugs. Copyright © 2016 Elsevier B.V. All rights reserved.

Selective chemical detection by energy modulation of sensors

DOEpatents

Stetter, J.R.; Otagawa, T.

1991-09-10

A portable instrument for use in the field in detecting, identifying, and quantifying a component of a sampled fluid includes a sensor which chemically reacts with the component of interest or a derivative thereof, an electrical heating filament for heating the sample before it is applied to the sensor, and modulator for continuously varying the temperature of the filament (and hence the reaction rate) between two values sufficient to produce the chemical reaction. In response to this thermal modulation, the sensor produces a modulated output signal, the modulation of which is a function of the activation energy of the chemical reaction, which activation energy is specific to the particular component of interest and its concentration. Microprocessor which compares the modulated output signal with standard responses for a plurality of components to identify and quantify the particular component of interest. In particular, the concentration of the component of interest is proportional to the amplitude of the modulated output signal, while the identifying activation output energy of the chemical interaction indicative of that component is proportional to a normalized parameter equal to the peak-to-peak amplitude divided by the height of the upper peaks above a base line signal level. 5 figures.

Selective chemical detection by energy modulation of sensors

DOEpatents

Stetter, Joseph R.; Otagawa, Takaaki

1991-01-01

A portable instrument for use in the field in detecting, identifying, and quantifying a component of a sampled fluid includes a sensor which chemically reacts with the component of interest or a derivative thereof, an electrical heating filament for heating the sample before it is applied to the sensor, and modulator for continuously varying the temperature of the filament (and hence the reaction rate) between two values sufficient to produce the chemical reaction. In response to this thermal modulation, the sensor produces a modulated output signal, the modulation of which is a function of the activation energy of the chemical reaction, which activation energy is specific to the particular component of interest and its concentration. Microprocessor which compares the modulated output signal with standard responses for a plurality of components to identify and quantify the particular component of interest. In particular, the concentration of the component of interest is proportional to the amplitude of the modulated output signal, while the identifying activation output energy of the chemical interaction indicative of that component is proportional to a normalized parameter equal to the peak-to-peak amplitude divided by the height of the upper peaks above a base line signal level.

Assessing the nonlinear response of fine particles to precursor emissions: Development and application of an extended response surface modeling technique v1.0

DOE PAGES

Zhao, B.; Wang, S. X.; Xing, J.; ...

2015-01-30

An innovative extended response surface modeling technique (ERSM v1.0) is developed to characterize the nonlinear response of fine particles (PM₂̣₅) to large and simultaneous changes of multiple precursor emissions from multiple regions and sectors. The ERSM technique is developed based on the conventional response surface modeling (RSM) technique; it first quantifies the relationship between PM₂̣₅ concentrations and the emissions of gaseous precursors from each single region using the conventional RSM technique, and then assesses the effects of inter-regional transport of PM₂̣₅ and its gaseous precursors on PM₂̣₅ concentrations in the target region. We apply this novel technique with a widelymore » used regional chemical transport model (CTM) over the Yangtze River delta (YRD) region of China, and evaluate the response of PM₂̣₅ and its inorganic components to the emissions of 36 pollutant–region–sector combinations. The predicted PM₂̣₅ concentrations agree well with independent CTM simulations; the correlation coefficients are larger than 0.98 and 0.99, and the mean normalized errors (MNEs) are less than 1 and 2% for January and August, respectively. It is also demonstrated that the ERSM technique could reproduce fairly well the response of PM₂̣₅ to continuous changes of precursor emission levels between zero and 150%. Employing this new technique, we identify the major sources contributing to PM₂̣₅ and its inorganic components in the YRD region. The nonlinearity in the response of PM₂̣₅ to emission changes is characterized and the underlying chemical processes are illustrated.« less

The chemical component dictionary: complete descriptions of constituent molecules in experimentally determined 3D macromolecules in the Protein Data Bank.

PubMed

Westbrook, John D; Shao, Chenghua; Feng, Zukang; Zhuravleva, Marina; Velankar, Sameer; Young, Jasmine

2015-04-15

The Chemical Component Dictionary (CCD) is a chemical reference data resource that describes all residue and small molecule components found in Protein Data Bank (PDB) entries. The CCD contains detailed chemical descriptions for standard and modified amino acids/nucleotides, small molecule ligands and solvent molecules. Each chemical definition includes descriptions of chemical properties such as stereochemical assignments, chemical descriptors, systematic chemical names and idealized coordinates. The content, preparation, validation and distribution of this CCD chemical reference dataset are described. The CCD is updated regularly in conjunction with the scheduled weekly release of new PDB structure data. The CCD and amino acid variant reference datasets are hosted in the public PDB ftp repository at ftp://ftp.wwpdb.org/pub/pdb/data/monomers/components.cif.gz, ftp://ftp.wwpdb.org/pub/pdb/data/monomers/aa-variants-v1.cif.gz, and its mirror sites, and can be accessed from http://wwpdb.org. jwest@rcsb.rutgers.edu. Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Environmental issues and work: women with multiple chemical sensitivities.

PubMed

Lipson, Juliene G; Doiron, Nathalie

2006-08-01

Multiple chemical sensitivities (MCS) is an acquired condition in which exposure to low levels of chemicals causes symptoms in multiple organ systems. Some 12%-16% of the U.S. population has some level of chemical sensitivity, 80% of whom are women. Attempts to reduce chemical exposures leads to enormous life difficulties at home, school, and workplace. We base our article on an ethnographic study of MCS in the United States and Canada. We describe here themes related to work issues in terms of a general trajectory of becoming sick from work exposures, coping with toxic physical environments and dealing with coworkers and, when unable to continue working, applying for workers' compensation, or disability status, or both.

Numerical modelling of multiphase multicomponent reactive transport in the Earth's interior

NASA Astrophysics Data System (ADS)

Oliveira, Beñat; Afonso, Juan Carlos; Zlotnik, Sergio; Diez, Pedro

2018-01-01

We present a conceptual and numerical approach to model processes in the Earth's interior that involve multiple phases that simultaneously interact thermally, mechanically and chemically. The approach is truly multiphase in the sense that each dynamic phase is explicitly modelled with an individual set of mass, momentum, energy and chemical mass balance equations coupled via interfacial interaction terms. It is also truly multicomponent in the sense that the compositions of the system and its constituent phases are expressed by a full set of fundamental chemical components (e.g. SiO2, Al2O3, MgO, etc.) rather than proxies. These chemical components evolve, react with and partition into different phases according to an internally consistent thermodynamic model. We combine concepts from Ensemble Averaging and Classical Irreversible Thermodynamics to obtain sets of macroscopic balance equations that describe the evolution of systems governed by multiphase multicomponent reactive transport (MPMCRT). Equilibrium mineral assemblages, their compositions and physical properties, and closure relations for the balance equations are obtained via a `dynamic' Gibbs free-energy minimization procedure (i.e. minimizations are performed on-the-fly as needed by the simulation). Surface tension and surface energy contributions to the dynamics and energetics of the system are taken into account. We show how complex rheologies, that is, visco-elasto-plastic, and/or different interfacial models can be incorporated into our MPMCRT ensemble-averaged formulation. The resulting model provides a reliable platform to study the dynamics and nonlinear feedbacks of MPMCRT systems of different nature and scales, as well as to make realistic comparisons with both geophysical and geochemical data sets. Several numerical examples are presented to illustrate the benefits and limitations of the model.

Applicability of UV laser-induced solid-state fluorescence spectroscopy for characterization of solid dosage forms.

PubMed

Woltmann, Eva; Meyer, Hans; Weigel, Diana; Pritzke, Heinz; Posch, Tjorben N; Kler, Pablo A; Schürmann, Klaus; Roscher, Jörg; Huhn, Carolin

2014-10-01

High production output of solid pharmaceutical formulations requires fast methods to ensure their quality. Likewise, fast analytical procedures are required in forensic sciences, for example at customs, to substantiate an initial suspicion. We here present the design and the optimization of an instrumental setup for rapid and non-invasive characterization of tablets by laser-induced fluorescence spectroscopy (with a UV-laser (λ ex = 266 nm) as excitation source) in reflection geometry. The setup was first validated with regard to repeatability, bleaching phenomena, and sensitivity. The effect on the spectra by the physical and chemical properties of the samples, e.g. their hardness, homogeneity, chemical composition, and granule grain size of the uncompressed material, using a series of tablets, manufactured in accordance with design of experiments, was investigated. Investigation of tablets with regard to homogeneity, especially, is extremely important in pharmaceutical production processes. We demonstrate that multiplicative scatter correction is an appropriate tool for data preprocessing of fluorescence spectra. Tablets with different physical and chemical characteristics can be discriminated well from their fluorescence spectra by subjecting the results to principal component analysis.

15 CFR 921.33 - Boundary changes, amendments to the management plan, and addition of multiple-site components.

Code of Federal Regulations, 2010 CFR

2010-01-01

... management plan, and addition of multiple-site components. 921.33 Section 921.33 Commerce and Foreign Trade... management plan, and addition of multiple-site components. (a) Changes in the boundary of a Reserve and major... management plan shall address goals and objectives for all components of the multi-site Reserve and the...

Skin Rejuvenation with Non-Invasive Pulsed Electric Fields

NASA Astrophysics Data System (ADS)

Golberg, Alexander; Khan, Saiqa; Belov, Vasily; Quinn, Kyle P.; Albadawi, Hassan; Felix Broelsch, G.; Watkins, Michael T.; Georgakoudi, Irene; Papisov, Mikhail; Mihm, Martin C., Jr.; Austen, William G., Jr.; Yarmush, Martin L.

2015-05-01

Degenerative skin diseases affect one third of individuals over the age of sixty. Current therapies use various physical and chemical methods to rejuvenate skin; but since the therapies affect many tissue components including cells and extracellular matrix, they may also induce significant side effects, such as scarring. Here we report on a new, non-invasive, non-thermal technique to rejuvenate skin with pulsed electric fields. The fields destroy cells while simultaneously completely preserving the extracellular matrix architecture and releasing multiple growth factors locally that induce new cells and tissue growth. We have identified the specific pulsed electric field parameters in rats that lead to prominent proliferation of the epidermis, formation of microvasculature, and secretion of new collagen at treated areas without scarring. Our results suggest that pulsed electric fields can improve skin function and thus can potentially serve as a novel non-invasive skin therapy for multiple degenerative skin diseases.

Simultaneous multi-beam planar array IR (pair) spectroscopy

DOEpatents

Elmore, Douglas L.; Rabolt, John F.; Tsao, Mei-Wei

2005-09-13

An apparatus and method capable of providing spatially multiplexed IR spectral information simultaneously in real-time for multiple samples or multiple spatial areas of one sample using IR absorption phenomena requires no moving parts or Fourier Transform during operation, and self-compensates for background spectra and degradation of component performance over time. IR spectral information and chemical analysis of the samples is determined by using one or more IR sources, sampling accessories for positioning the samples, optically dispersive elements, a focal plane array (FPA) arranged to detect the dispersed light beams, and a processor and display to control the FPA, and display an IR spectrograph. Fiber-optic coupling can be used to allow remote sensing. Portability, reliability, and ruggedness is enhanced due to the no-moving part construction. Applications include determining time-resolved orientation and characteristics of materials, including polymer monolayers. Orthogonal polarizers may be used to determine certain material characteristics.

Applications of the Phytomedicine Echinacea purpurea (Purple Coneflower) in Infectious Diseases

PubMed Central

Hudson, James B.

2012-01-01

Extracts of Echinacea purpurea (EP, purple coneflower) have been used traditionally in North America for the treatment of various types of infections and wounds, and they have become very popular herbal medicines globally. Recent studies have revealed that certain standardized preparations contain potent and selective antiviral and antimicrobial activities. In addition, they display multiple immune-modulatory activities, comprising stimulation of certain immune functions such as phagocytic activity of macrophages and suppression of the proinflammatory responses of epithelial cells to viruses and bacteria, which are manifested as alterations in secretion of various cytokines and chemokines. These immune modulations result from upregulation or downregulation of the relevant genes and their transcription factors. All these bioactivities can be demonstrated at noncytotoxic concentrations of extract and appear to be due to multiple components rather than the individual chemical compounds that characterize Echinacea extracts. Potential applications of the bioactive extracts may go beyond their traditional uses. PMID:22131823

The component content of active particles in a plasma-chemical reactor based on volume barrier discharge

NASA Astrophysics Data System (ADS)

Soloshenko, I. A.; Tsiolko, V. V.; Pogulay, S. S.; Terent'yeva, A. G.; Bazhenov, V. Yu; Shchedrin, A. I.; Ryabtsev, A. V.; Kuzmichev, A. I.

2007-02-01

In this paper the results of theoretical and experimental studies of the component content of active particles formed in a plasma-chemical reactor composed of a multiple-cell generator of active particles, based on volume barrier discharge, and a working chamber are presented. For calculation of the content of uncharged plasma components an approach is proposed which is based on averaging of the power introduced over the entire volume. Advantages of such an approach lie in an absence of fitting parameters, such as the dimensions of microdischarges, their surface density and rate of breakdown. The calculation and the experiment were accomplished with the use of dry air (20% relative humidity) as the plasma generating medium. Concentrations of O3, HNO3, HNO2, N2 O5 and NO3 were measured experimentally in the discharge volume and working chamber for the residence time of particles on a discharge of 0.3 s and more and discharge specific power of 1.5 W cm-3. It has been determined that the best agreement between the calculation and the experiment occurs at calculated gas medium temperatures in the discharge plasma of about 400-425 K, which correspond to the experimentally measured rotational temperature of nitrogen. In most cases the calculated concentrations of O3, HNO3, HNO2, N2O5 and NO3 for the barrier discharge and the working chamber are in fairly good agreement with the respective measured values.

Rapid Characterization of Components in Bolbostemma paniculatum by UPLC/LTQ-Orbitrap MSn Analysis and Multivariate Statistical Analysis for Herb Discrimination.

PubMed

Zeng, Yanling; Lu, Yang; Chen, Zhao; Tan, Jiawei; Bai, Jie; Li, Pengyue; Wang, Zhixin; Du, Shouying

2018-05-11

Bolbostemma paniculatum is a traditional Chinese medicine (TCM) showed various therapeutic effects. Owing to its complex chemical composition, few investigations have acquired a comprehensive cognition for the chemical profiles of this herb and explicated the differences between samples collected from different places. In this study, a strategy based on UPLC tandem LTQ-Orbitrap MS n was established for characterizing chemical components of B. paniculatum . Through a systematic identification strategy, a total of 60 components in B. paniculatum were rapidly separated in 30 min and identified. Then based on peak intensities of all the characterized components, principle component analysis (PCA) and hierarchical cluster analysis (HCA) were employed to classify 18 batches of B. paniculatum into four groups, which were highly consistent with the four climate types of their original places. And five compounds were finally screened out as chemical markers to discriminate the internal quality of B. paniculatum . As the first study to systematically characterize the chemical components of B. paniculatum by UPLC-MS n , the above results could offer essential data for its pharmacological research. And the current strategy could provide useful reference for future investigations on discovery of important chemical constituents in TCM, as well as establishment of quality control and evaluation method.

Monolithic beam steering in a mid-infrared, surface-emitting, photonic integrated circuit.

PubMed

Slivken, Steven; Wu, Donghai; Razeghi, Manijeh

2017-08-16

The mid-infrared (2.5 < λ < 25 μm) spectral region is utilized for many purposes, such as chemical/biological sensing, free space communications, and illuminators/countermeasures. Compared to near-infrared optical systems, however, mid-infrared component technology is still rather crude, with isolated components exhibiting limited functionality. In this manuscript, we make a significant leap forward in mid-infrared technology by developing a platform which can combine functions of multiple mid-infrared optical elements, including an integrated light source. In a single device, we demonstrate wide wavelength tuning (240 nm) and beam steering (17.9 degrees) in the mid-infrared with a significantly reduced beam divergence (down to 0.5 degrees). The architecture is also set up to be manufacturable and testable on a wafer scale, requiring no cleaved facets or special mirror coating to function.

Computation material science of structural-phase transformation in casting aluminium alloys

NASA Astrophysics Data System (ADS)

Golod, V. M.; Dobosh, L. Yu

2017-04-01

Successive stages of computer simulation the formation of the casting microstructure under non-equilibrium conditions of crystallization of multicomponent aluminum alloys are presented. On the basis of computer thermodynamics and heat transfer during solidification of macroscale shaped castings are specified the boundary conditions of local heat exchange at mesoscale modeling of non-equilibrium formation the solid phase and of the component redistribution between phases during coalescence of secondary dendrite branches. Computer analysis of structural - phase transitions based on the principle of additive physico-chemical effect of the alloy components in the process of diffusional - capillary morphological evolution of the dendrite structure and the o of local dendrite heterogeneity which stochastic nature and extent are revealed under metallographic study and modeling by the Monte Carlo method. The integrated computational materials science tools at researches of alloys are focused and implemented on analysis the multiple-factor system of casting processes and prediction of casting microstructure.

Burst and Principal Components Analyses of MEA Data Separates Chemicals by Class

EPA Science Inventory

Microelectrode arrays (MEAs) detect drug and chemical induced changes in action potential "spikes" in neuronal networks and can be used to screen chemicals for neurotoxicity. Analytical "fingerprinting," using Principal Components Analysis (PCA) on spike trains recorded from prim...

Clustering the Orion B giant molecular cloud based on its molecular emission.

PubMed

Bron, Emeric; Daudon, Chloé; Pety, Jérôme; Levrier, François; Gerin, Maryvonne; Gratier, Pierre; Orkisz, Jan H; Guzman, Viviana; Bardeau, Sébastien; Goicoechea, Javier R; Liszt, Harvey; Öberg, Karin; Peretto, Nicolas; Sievers, Albrecht; Tremblin, Pascal

2018-02-01

Previous attempts at segmenting molecular line maps of molecular clouds have focused on using position-position-velocity data cubes of a single molecular line to separate the spatial components of the cloud. In contrast, wide field spectral imaging over a large spectral bandwidth in the (sub)mm domain now allows one to combine multiple molecular tracers to understand the different physical and chemical phases that constitute giant molecular clouds (GMCs). We aim at using multiple tracers (sensitive to different physical processes and conditions) to segment a molecular cloud into physically/chemically similar regions (rather than spatially connected components), thus disentangling the different physical/chemical phases present in the cloud. We use a machine learning clustering method, namely the Meanshift algorithm, to cluster pixels with similar molecular emission, ignoring spatial information. Clusters are defined around each maximum of the multidimensional Probability Density Function (PDF) of the line integrated intensities. Simple radiative transfer models were used to interpret the astrophysical information uncovered by the clustering analysis. A clustering analysis based only on the J = 1 - 0 lines of three isotopologues of CO proves suffcient to reveal distinct density/column density regimes ( n H ~ 100 cm -3 , ~ 500 cm -3 , and > 1000 cm -3 ), closely related to the usual definitions of diffuse, translucent and high-column-density regions. Adding two UV-sensitive tracers, the J = 1 - 0 line of HCO + and the N = 1 - 0 line of CN, allows us to distinguish two clearly distinct chemical regimes, characteristic of UV-illuminated and UV-shielded gas. The UV-illuminated regime shows overbright HCO + and CN emission, which we relate to a photochemical enrichment effect. We also find a tail of high CN/HCO + intensity ratio in UV-illuminated regions. Finer distinctions in density classes ( n H ~ 7 × 10 3 cm -3 ~ 4 × 10 4 cm -3 ) for the densest regions are also identified, likely related to the higher critical density of the CN and HCO + (1 - 0) lines. These distinctions are only possible because the high-density regions are spatially resolved. Molecules are versatile tracers of GMCs because their line intensities bear the signature of the physics and chemistry at play in the gas. The association of simultaneous multi-line, wide-field mapping and powerful machine learning methods such as the Meanshift clustering algorithm reveals how to decode the complex information available in these molecular tracers.

Additive mixture effects of estrogenic chemicals in human cell-based assays can be influenced by inclusion of chemicals with differing effect profiles.

PubMed

Evans, Richard Mark; Scholze, Martin; Kortenkamp, Andreas

2012-01-01

A growing body of experimental evidence indicates that the in vitro effects of mixtures of estrogenic chemicals can be well predicted from the estrogenicity of their components by the concentration addition (CA) concept. However, some studies have observed small deviations from CA. Factors affecting the presence or observation of deviations could include: the type of chemical tested; number of mixture components; mixture design; and assay choice. We designed mixture experiments that address these factors, using mixtures with high numbers of components, chemicals from diverse chemical groups, assays with different in vitro endpoints and different mixture designs and ratios. Firstly, the effects of mixtures composed of up to 17 estrogenic chemicals were examined using estrogenicity assays with reporter-gene (ERLUX) and cell proliferation (ESCREEN) endpoints. Two mixture designs were used: 1) a 'balanced' design with components present in proportion to a common effect concentration (e.g. an EC(10)) and 2) a 'non-balanced' design with components in proportion to potential human tissue concentrations. Secondly, the individual and simultaneous ability of 16 potential modulator chemicals (each with minimal estrogenicity) to influence the assay outcome produced by a reference mixture of estrogenic chemicals was examined. Test chemicals included plasticizers, phthalates, metals, PCBs, phytoestrogens, PAHs, heterocyclic amines, antioxidants, UV filters, musks, PBDEs and parabens. In all the scenarios tested, the CA concept provided a good prediction of mixture effects. Modulation studies revealed that chemicals possessing minimal estrogenicity themselves could reduce (negatively modulate) the effect of a mixture of estrogenic chemicals. Whether the type of modulation we observed occurs in practice most likely depends on the chemical concentrations involved, and better information is required on likely human tissue concentrations of estrogens and of potential modulators. Successful prediction of the effects of diverse chemical combinations might be more likely if chemical profiling included consideration of effect modulation.

Additive Mixture Effects of Estrogenic Chemicals in Human Cell-Based Assays Can Be Influenced by Inclusion of Chemicals with Differing Effect Profiles

PubMed Central

Evans, Richard Mark; Scholze, Martin; Kortenkamp, Andreas

2012-01-01

A growing body of experimental evidence indicates that the in vitro effects of mixtures of estrogenic chemicals can be well predicted from the estrogenicity of their components by the concentration addition (CA) concept. However, some studies have observed small deviations from CA. Factors affecting the presence or observation of deviations could include: the type of chemical tested; number of mixture components; mixture design; and assay choice. We designed mixture experiments that address these factors, using mixtures with high numbers of components, chemicals from diverse chemical groups, assays with different in vitro endpoints and different mixture designs and ratios. Firstly, the effects of mixtures composed of up to 17 estrogenic chemicals were examined using estrogenicity assays with reporter-gene (ERLUX) and cell proliferation (ESCREEN) endpoints. Two mixture designs were used: 1) a ‘balanced’ design with components present in proportion to a common effect concentration (e.g. an EC10) and 2) a ‘non-balanced’ design with components in proportion to potential human tissue concentrations. Secondly, the individual and simultaneous ability of 16 potential modulator chemicals (each with minimal estrogenicity) to influence the assay outcome produced by a reference mixture of estrogenic chemicals was examined. Test chemicals included plasticizers, phthalates, metals, PCBs, phytoestrogens, PAHs, heterocyclic amines, antioxidants, UV filters, musks, PBDEs and parabens. In all the scenarios tested, the CA concept provided a good prediction of mixture effects. Modulation studies revealed that chemicals possessing minimal estrogenicity themselves could reduce (negatively modulate) the effect of a mixture of estrogenic chemicals. Whether the type of modulation we observed occurs in practice most likely depends on the chemical concentrations involved, and better information is required on likely human tissue concentrations of estrogens and of potential modulators. Successful prediction of the effects of diverse chemical combinations might be more likely if chemical profiling included consideration of effect modulation. PMID:22912892

Spatial pattern separation of chemicals and frequency-independent components by terahertz spectroscopic imaging

NASA Astrophysics Data System (ADS)

Watanabe, Yuuki; Kawase, Kodo; Ikari, Tomofumi; Ito, Hiromasa; Ishikawa, Youichi; Minamide, Hiroaki

2003-10-01

We separated the component spatial patterns of frequency-dependent absorption in chemicals and frequency-independent components such as plastic, paper, and measurement noise in terahertz (THz) spectroscopic images, using known spectral curves. Our measurement system, which uses a widely tunable coherent THz-wave parametric oscillator source, can image at a specific frequency in the range 1-2 THz. The component patterns of chemicals can easily be extracted by use of the frequency-independent components. This method could be successfully used for nondestructive inspection for the detection of illegal drugs and devices of bioterrorism concealed, e.g., inside mail and packages.

Simultaneous detection of multiple adulterants in dry milk using macro-scale Raman chemical imaging

USDA-ARS?s Scientific Manuscript database

The potential of Raman chemical imaging for simultaneously detecting multiple adulterants in milk powder was investigated. Potential chemical adulterants, including ammonium sulfate, dicyandiamide, melamine, and urea, were mixed together into skim dry milk in the concentration range of 0.1–5.0% for ...

Selective chemical detection by energy modulation of sensors

DOEpatents

Stetter, J.R.; Otagawa, T.

1985-05-20

A portable instrument for use in the field in detecting, identifying, and quantifying a component of a sampled fluid includes a sensor which chemically reacts with the component of interest or a derivative thereof, an electrical heating filament for heating the sample before it is applied to the sensor, and modulating means for continuously varying the temperature of the filament (and hence the reaction rate) between two values sufficient to produce the chemical reaction. In response to this thermal modulation, the sensor produces a modulated output signal, the modulation of which is a function of the activation energy of the chemical reaction, which activation energy is specific to the particular component of interest and its concentration. Microprocessor means compares the modulated output signal with standard responses for a plurality of components to identify and quantify the particular component of interest. 4 figs.

Comparative Evaluation of Preprocessing Freeware on Chromatography/Mass Spectrometry Data for Signature Discovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coble, Jamie B.; Fraga, Carlos G.

2014-07-07

Preprocessing software is crucial for the discovery of chemical signatures in metabolomics, chemical forensics, and other signature-focused disciplines that involve analyzing large data sets from chemical instruments. Here, four freely available and published preprocessing tools known as metAlign, MZmine, SpectConnect, and XCMS were evaluated for impurity profiling using nominal mass GC/MS data and accurate mass LC/MS data. Both data sets were previously collected from the analysis of replicate samples from multiple stocks of a nerve-agent precursor. Each of the four tools had their parameters set for the untargeted detection of chromatographic peaks from impurities present in the stocks. The peakmore » table generated by each preprocessing tool was analyzed to determine the number of impurity components detected in all replicate samples per stock. A cumulative set of impurity components was then generated using all available peak tables and used as a reference to calculate the percent of component detections for each tool, in which 100% indicated the detection of every component. For the nominal mass GC/MS data, metAlign performed the best followed by MZmine, SpectConnect, and XCMS with detection percentages of 83, 60, 47, and 42%, respectively. For the accurate mass LC/MS data, the order was metAlign, XCMS, and MZmine with detection percentages of 80, 45, and 35%, respectively. SpectConnect did not function for the accurate mass LC/MS data. Larger detection percentages were obtained by combining the top performer with at least one of the other tools such as 96% by combining metAlign with MZmine for the GC/MS data and 93% by combining metAlign with XCMS for the LC/MS data. In terms of quantitative performance, the reported peak intensities had average absolute biases of 41, 4.4, 1.3 and 1.3% for SpectConnect, metAlign, XCMS, and MZmine, respectively, for the GC/MS data. For the LC/MS data, the average absolute biases were 22, 4.5, and 3.1% for metAlign, MZmine, and XCMS, respectively. In summary, metAlign performed the best in terms of peak discovery; however, more than one preprocessing tool should be considered to avoid missing potential chemical signatures.« less

Living supramolecular polymerization achieved by collaborative assembly of platinum(II) complexes and block copolymers

PubMed Central

Zhang, Kaka; Yeung, Margaret Ching-Lam; Leung, Sammual Yu-Lut; Yam, Vivian Wing-Wah

2017-01-01

An important feature of biological systems to achieve complexity and precision is the involvement of multiple components where each component plays its own role and collaborates with other components. Mimicking this, we report living supramolecular polymerization achieved by collaborative assembly of two structurally dissimilar components, that is, platinum(II) complexes and poly(ethylene glycol)-b-poly(acrylic acid) (PEG-b-PAA). The PAA blocks neutralize the charges of the platinum(II) complexes, with the noncovalent metal–metal and π–π interactions directing the longitudinal growth of the platinum(II) complexes into 1D crystalline nanostructures, and the PEG blocks inhibiting the transverse growth of the platinum(II) complexes and providing the whole system with excellent solubility. The ends of the 1D crystalline nanostructures have been found to be active during the assembly and remain active after the assembly. One-dimensional segmented nanostructures with heterojunctions have been produced by sequential growth of two types of platinum(II) complexes. The PAA blocks act as adapters at the heterojunctions for lattice matching between chemically and crystallographically different platinum(II) complexes, achieving heterojunctions with a lattice mismatch as large as 21%. PMID:29078381

Quality of Chemical Safety Information in Printing Industry.

PubMed

Tsai, Chung-Jung; Mao, I-Fang; Ting, Jo-Yu; Young, Chi-Hsien; Lin, Jhih-Sian; Li, Wei-Lun

2016-04-01

Employees in printing industries can be exposed to multiple solvents in their work environment. The objectives of this study were to investigate the critical components of chemical solvents by analyzing the components of the solvents and collecting the Safety data sheets (SDSs), and to evaluate the hazard communication implementation status in printing industries. About 152 printing-related industries were recruited by area-stratified random sampling and included 23 plate-making, 102 printing and 27 printing-assistance companies in Taiwan. We analyzed company questionnaires (n = 152), SDSs (n = 180), and solvents (n = 20) collected from this sample of printing-related companies. Analytical results indicated that benzene and ethylbenzene, which were carcinogen and possibly carcinogen, were detectable in the cleaning solvents, and the detection rate were 54.5% (concentrations: <0.011-0.035 wt%) and 63.6% (concentrations: <0.011-6.22 wt%), respectively; however, neither compound was disclosed in the SDS for the solvents. Several other undisclosed components, including methanol, isopropanol and n-butanol, were also identified in the printing inks, fountain solutions and dilution solvents. We noted that, of the companies we surveyed, only 57.2% had a hazard communication program, 61.8% had SDSs on file and 59.9% provided employee safety and health training. We note that hazard communication programs were missing or ineffective in almost half of the 152 printing industries surveyed. Current safety information of solvents components in printing industries was inadequate, and many hazardous compounds were undisclosed in the SDSs of the solvents or the labels of the containers. The implementation of hazard communications in printing industries was still not enough for protecting the employees' safety and health. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Quality of Chemical Safety Information in Printing Industry

PubMed Central

Tsai, Chung-Jung; Mao, I-Fang; Ting, Jo-Yu; Young, Chi-Hsien; Lin, Jhih-Sian; Li, Wei-Lun

2016-01-01

Objectives: Employees in printing industries can be exposed to multiple solvents in their work environment. The objectives of this study were to investigate the critical components of chemical solvents by analyzing the components of the solvents and collecting the Safety data sheets (SDSs), and to evaluate the hazard communication implementation status in printing industries. Method: About 152 printing-related industries were recruited by area-stratified random sampling and included 23 plate-making, 102 printing and 27 printing-assistance companies in Taiwan. We analyzed company questionnaires (n = 152), SDSs (n = 180), and solvents (n = 20) collected from this sample of printing-related companies. Results: Analytical results indicated that benzene and ethylbenzene, which were carcinogen and possibly carcinogen, were detectable in the cleaning solvents, and the detection rate were 54.5% (concentrations: <0.011–0.035 wt%) and 63.6% (concentrations: <0.011–6.22 wt%), respectively; however, neither compound was disclosed in the SDS for the solvents. Several other undisclosed components, including methanol, isopropanol and n-butanol, were also identified in the printing inks, fountain solutions and dilution solvents. We noted that, of the companies we surveyed, only 57.2% had a hazard communication program, 61.8% had SDSs on file and 59.9% provided employee safety and health training. We note that hazard communication programs were missing or ineffective in almost half of the 152 printing industries surveyed. Conclusions: Current safety information of solvents components in printing industries was inadequate, and many hazardous compounds were undisclosed in the SDSs of the solvents or the labels of the containers. The implementation of hazard communications in printing industries was still not enough for protecting the employees’ safety and health. PMID:26568584

The Effects of Chlordiazepoxide and d-Amphetamine during a Three-Component Multiple Schedule

PubMed Central

Romanowich, Paul; Lamb, R. J.

2013-01-01

Multiple schedules have been used in behavioral pharmacology research to show that a drug’s effect on behavior can be a function of the schedule of reinforcement that supports that behavior. However, less research has examined whether the context of the schedule of reinforcement in a multiple schedule can change the drug’s effect on behavior. We examined the effects of acute chlordiazepoxide and d-amphetamine injections on the behavior of two groups of pigeons trained on a three-component multiple schedule with identical schedules of reinforcement in the first and last components. For one group of pigeons reinforcement was unavailable during the middle component (decreased-middle-component). For the second group reinforcement rate was higher during the middle component than during the first or third components (increased-middle-component). In the decreased-middle-component group, chlordiazepoxide (3.2-32 mg/kg) decreased third-component response rates less than it decreased responding in the first component. Conversely, in the increased-middle-component group, chlordiazepoxide (3.2-10 mg/kg) decreased third-component response rates more than in the first component. In both groups, d-amphetamine did not differentially affect response rates across components. These results are consistent with previous research showing that drugs can differentially affect responding to two different schedules of reinforcement during the same session, and suggest that pharmacological preparations may be helpful in elucidating the mechanisms that control multiple schedule interactions. PMID:23633164

The XRD Amorphous Component in John Klein Drill Fines at Yellowknife Bay, Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Morris, Richard V.; Ming,, Douglas W.; Blake, David; Vaniman, David; Bish, David L; Chipera, Steve; Downs, Robert; Morrison, Shaunna; Gellert, Ralf; Campbell, Iain;

Comparison of five Lonicera flowers by simultaneous determination of multi-components with single reference standard method and principal component analysis.

PubMed

Gao, Wen; Wang, Rui; Li, Dan; Liu, Ke; Chen, Jun; Li, Hui-Jun; Xu, Xiaojun; Li, Ping; Yang, Hua

2016-01-05

The flowers of Lonicera japonica Thunb. were extensively used to treat many diseases. As the demands for L. japonica increased, some related Lonicera plants were often confused or misused. Caffeoylquinic acids were always regarded as chemical markers in the quality control of L. japonica, but they could be found in all Lonicera species. Thus, a simple and reliable method for the evaluation of different Lonicera flowers is necessary to be established. In this work a method based on single standard to determine multi-components (SSDMC) combined with principal component analysis (PCA) for control and distinguish of Lonicera species flowers have been developed. Six components including three caffeoylquinic acids and three iridoid glycosides were assayed simultaneously using chlorogenic acid as the reference standard. The credibility and feasibility of the SSDMC method were carefully validated and the results demonstrated that there were no remarkable differences compared with external standard method. Finally, a total of fifty-one batches covering five Lonicera species were analyzed and PCA was successfully applied to distinguish the Lonicera species. This strategy simplifies the processes in the quality control of multiple-componential herbal medicine which effectively adapted for improving the quality control of those herbs belonging to closely related species. Copyright © 2015 Elsevier B.V. All rights reserved.

Appraisal of unimodal cues during agonistic interactions in Maylandia zebra

PubMed Central

Ben Ammar, Imen; Fernandez, Marie S.A.; Boyer, Nicolas; Attia, Joël; Fonseca, Paulo J.; Amorim, M. Clara P.; Beauchaud, Marilyn

2017-01-01

Communication is essential during social interactions including animal conflicts and it is often a complex process involving multiple sensory channels or modalities. To better understand how different modalities interact during communication, it is fundamental to study the behavioural responses to both the composite multimodal signal and each unimodal component with adequate experimental protocols. Here we test how an African cichlid, which communicates with multiple senses, responds to different sensory stimuli in a social relevant scenario. We tested Maylandia zebra males with isolated chemical (urine or holding water coming both from dominant males), visual (real opponent or video playback) and acoustic (agonistic sounds) cues during agonistic interactions. We showed that (1) these fish relied mostly on the visual modality, showing increased aggressiveness in response to the sight of a real contestant but no responses to urine or agonistic sounds presented separately, (2) video playback in our study did not appear appropriate to test the visual modality and needs more technical prospecting, (3) holding water provoked territorial behaviours and seems to be promising for the investigation into the role of the chemical channel in this species. Our findings suggest that unimodal signals are non-redundant but how different sensory modalities interplay during communication remains largely unknown in fish. PMID:28785523

Comparative proteomic assessment of matrisome enrichment methodologies

PubMed Central

Krasny, Lukas; Paul, Angela; Wai, Patty; Howard, Beatrice A.; Natrajan, Rachael C.; Huang, Paul H.

2016-01-01

The matrisome is a complex and heterogeneous collection of extracellular matrix (ECM) and ECM-associated proteins that play important roles in tissue development and homeostasis. While several strategies for matrisome enrichment have been developed, it is currently unknown how the performance of these different methodologies compares in the proteomic identification of matrisome components across multiple tissue types. In the present study, we perform a comparative proteomic assessment of two widely used decellularisation protocols and two extraction methods to characterise the matrisome in four murine organs (heart, mammary gland, lung and liver). We undertook a systematic evaluation of the performance of the individual methods on protein yield, matrisome enrichment capability and the ability to isolate core matrisome and matrisome-associated components. Our data find that sodium dodecyl sulphate (SDS) decellularisation leads to the highest matrisome enrichment efficiency, while the extraction protocol that comprises chemical and trypsin digestion of the ECM fraction consistently identifies the highest number of matrisomal proteins across all types of tissue examined. Matrisome enrichment had a clear benefit over non-enriched tissue for the comprehensive identification of matrisomal components in murine liver and heart. Strikingly, we find that all four matrisome enrichment methods led to significant losses in the soluble matrisome-associated proteins across all organs. Our findings highlight the multiple factors (including tissue type, matrisome class of interest and desired enrichment purity) that influence the choice of enrichment methodology, and we anticipate that these data will serve as a useful guide for the design of future proteomic studies of the matrisome. PMID:27589945

Ants regulate colony spatial organization using multiple chemical road-signs

PubMed Central

Heyman, Yael; Shental, Noam; Brandis, Alexander; Hefetz, Abraham; Feinerman, Ofer

2017-01-01

Communication provides the basis for social life. In ant colonies, the prevalence of local, often chemically mediated, interactions introduces strong links between communication networks and the spatial distribution of ants. It is, however, unknown how ants identify and maintain nest chambers with distinct functions. Here, we combine individual tracking, chemical analysis and machine learning to decipher the chemical signatures present on multiple nest surfaces. We present evidence for several distinct chemical ‘road-signs' that guide the ants' movements within the dark nest. These chemical signatures can be used to classify nest chambers with different functional roles. Using behavioural manipulations, we demonstrate that at least three of these chemical signatures are functionally meaningful and allow ants from different task groups to identify their specific nest destinations, thus facilitating colony coordination and stabilization. The use of multiple chemicals that assist spatiotemporal guidance, segregation and pattern formation is abundant in multi-cellular organisms. Here, we provide a rare example for the use of these principles in the ant colony. PMID:28569746

Ants regulate colony spatial organization using multiple chemical road-signs.

PubMed

Heyman, Yael; Shental, Noam; Brandis, Alexander; Hefetz, Abraham; Feinerman, Ofer

2017-06-01

Communication provides the basis for social life. In ant colonies, the prevalence of local, often chemically mediated, interactions introduces strong links between communication networks and the spatial distribution of ants. It is, however, unknown how ants identify and maintain nest chambers with distinct functions. Here, we combine individual tracking, chemical analysis and machine learning to decipher the chemical signatures present on multiple nest surfaces. We present evidence for several distinct chemical 'road-signs' that guide the ants' movements within the dark nest. These chemical signatures can be used to classify nest chambers with different functional roles. Using behavioural manipulations, we demonstrate that at least three of these chemical signatures are functionally meaningful and allow ants from different task groups to identify their specific nest destinations, thus facilitating colony coordination and stabilization. The use of multiple chemicals that assist spatiotemporal guidance, segregation and pattern formation is abundant in multi-cellular organisms. Here, we provide a rare example for the use of these principles in the ant colony.

A mathematical analysis of multiple-target SELEX.

PubMed

Seo, Yeon-Jung; Chen, Shiliang; Nilsen-Hamilton, Marit; Levine, Howard A

2010-10-01

SELEX (Systematic Evolution of Ligands by Exponential Enrichment) is a procedure by which a mixture of nucleic acids can be fractionated with the goal of identifying those with specific biochemical activities. One combines the mixture with a specific target molecule and then separates the target-NA complex from the resulting reactions. The target-NA complex is separated from the unbound NA by mechanical means (such as by filtration), the NA is eluted from the complex, amplified by PCR (polymerase chain reaction), and the process repeated. After several rounds, one should be left with the nucleic acids that best bind to the target. The problem was first formulated mathematically in Irvine et al. (J. Mol. Biol. 222:739-761, 1991). In Levine and Nilsen-Hamilton (Comput. Biol. Chem. 31:11-25, 2007), a mathematical analysis of the process was given. In Vant-Hull et al. (J. Mol. Biol. 278:579-597, 1998), multiple target SELEX was considered. It was assumed that each target has a single nucleic acid binding site that permits occupation by no more than one nucleic acid. Here, we revisit Vant-Hull et al. (J. Mol. Biol. 278:579-597, 1998) using the same assumptions. The iteration scheme is shown to be convergent and a simplified algorithm is given. Our interest here is in the behavior of the multiple target SELEX process as a discrete "time" dynamical system. Our goal is to characterize the limiting states and their dependence on the initial distribution of nucleic acid and target fraction components. (In multiple target SELEX, we vary the target component fractions, but not their concentrations, as fixed and the initial pool of nucleic acids as a variable starting condition). Given N nucleic acids and a target consisting of M subtarget component species, there is an M × N matrix of affinities, the (i,j) entry corresponding to the affinity of the jth nucleic acid for the ith subtarget. We give a structure condition on this matrix that is equivalent to the following statement: For any initial pool of nucleic acids such that all N species are represented, the dynamical system defined by the multiple target SELEX process will converge to a unique subset of nucleic acids, each of whose concentrations depend only upon the total nucleic acid concentration, the initial fractional target distribution (both of which are assumed to be the same from round to round), and the overall limiting association constant. (The overall association constant is the equilibrium constant for the system of MN reactions when viewed as a composite single reaction). This condition is equivalent to the statement that every member of a certain family of chemical potentials at infinite target dilution can have at most one critical point. (The condition replaces the statement for single target SELEX that the dynamical system generated via the process always converges to a pool that contains only the nucleic acid that binds best to the target). This suggests that the effectiveness of multiple target SELEX as a separation procedure may not be as useful as single target SELEX unless the thermodynamic properties of these chemical potentials are well understood.

Functionalized xenon as a biosensor

PubMed Central

Spence, Megan M.; Rubin, Seth M.; Dimitrov, Ivan E.; Ruiz, E. Janette; Wemmer, David E.; Pines, Alexander; Yao, Shao Qin; Tian, Feng; Schultz, Peter G.

2001-01-01

The detection of biological molecules and their interactions is a significant component of modern biomedical research. In current biosensor technologies, simultaneous detection is limited to a small number of analytes by the spectral overlap of their signals. We have developed an NMR-based xenon biosensor that capitalizes on the enhanced signal-to-noise, spectral simplicity, and chemical-shift sensitivity of laser-polarized xenon to detect specific biomolecules at the level of tens of nanomoles. We present results using xenon “functionalized” by a biotin-modified supramolecular cage to detect biotin–avidin binding. This biosensor methodology can be extended to a multiplexing assay for multiple analytes. PMID:11535830

Sampling phasic dopamine signaling with fast-scan cyclic voltammetry in awake behaving rats

PubMed Central

Fortin, SM; Cone, JJ; Ng-Evans, S; McCutcheon, JE; Roitman, MF

2015-01-01

Fast-scan cyclic voltammetry (FSCV) is an electrochemical technique which permits the in vivo measurement of extracellular fluctuations in multiple chemical species. The technique is frequently utilized to sample sub-second (phasic) concentration changes of the neurotransmitter dopamine in awake and behaving rats. Phasic dopamine signaling is implicated in reinforcement, goal-directed behavior, and locomotion and FSCV has been used to investigate how rapid changes in striatal dopamine concentration contribute to these and other behaviors. This unit describes the instrumentation and construction, implantation, and use of necessary components required to sample and analyze dopamine concentration changes in awake rats with FSCV. PMID:25559005

Detrital and early chemical remanent magnetization in redbeds and their rock magnetic signature: Zicapa Formation, southern Mexico

NASA Astrophysics Data System (ADS)

Sierra-Rojas, Maria Isabel; Molina-Garza, Roberto Stanley

2018-06-01

Poles from continental redbeds are a large fraction of the world's palaeomagnetic database. Nonetheless, the time of acquisition and origin of the remanent magnetization of redbeds has been long debated. We report palaeomagnetic data, rock magnetic data and microscope observations for Lower Cretaceous redbeds in southern Mexico. These data allow us to discriminate between the hysteresis properties of remanent magnetizations of detrital and chemical origin, and to establish the early origin of a chemical remanence. Red sandstones of the Zicapa Formation contain a multicomponent remanence revealed by thermal demagnetization, and consisting of three stable components with partially overlapping laboratory unblocking temperatures of <250 °C, ˜300 to ˜500 °C and >600 °C, (low, intermediate and high temperature, respectively). They are interpreted as a viscous remanence residing in detrital magnetite, a chemical remanence residing in authigenic hematite and a depositional remanence residing in detrital hematite, respectively. The low-temperature component is nearly parallel to the recent dipole field. The tilt-corrected overall site means of the intermediate (chemical) and high temperature (depositional) components are indistinguishable (Dec = 282.0°, Inc = 12.4°, k = 13.33, α95 = 10.1°, N = 17, for the intermediate temperature; and Dec = 272.5°, Inc = 16.5°, k = 14.04, α95 = 11, N = 14, for the high temperature). Elongation/inclination analysis suggests that depositional and chemical components require applying an f = factor of approximately 0.4. Both of these components define a magnetic polarity zonation, but the polarity of the chemical and detrital components may or may not be the same. The chemical remanence coincides, more often than not, with the polarity of the depositional remanence of the overlying (younger) strata, suggesting a delay in remanence acquisition of tens to a few hundred ka for the chemical component. Pigmentary and detrital haematite were recognized with microscopic observations. The particle size of haematite ranges from approximately 10 to 300 μm for detrital haematite (martite, specularite and laterite), and from ca. 0.2 to 1 μm for pigmentary haematite flakes. The IRM of these rocks can be modelled with components of low coercivity (H1/2 between 5 and 10 mT interpreted as detrital magnetite), and components of a wide coercivity range (prevailing H1/2 from ˜400 to 600 mT interpreted as haematite). Hysteresis ratios show a systematic correlation with demagnetization behaviour, with lower Hcr/Hc values and higher Mrs/Ms values for samples with a dominant chemical component, than form samples with a significant (>40 per cent) depositional component.

NutriChem: a systems chemical biology resource to explore the medicinal value of plant-based foods.

PubMed

Jensen, Kasper; Panagiotou, Gianni; Kouskoumvekaki, Irene

2015-01-01

There is rising evidence of an inverse association between chronic diseases and diets characterized by rich fruit and vegetable consumption. Dietary components may act directly or indirectly on the human genome and modulate multiple processes involved in disease risk and disease progression. However, there is currently no exhaustive resource on the health benefits associated to specific dietary interventions, or a resource covering the broad molecular content of food. Here we present the first release of NutriChem, available at http://cbs.dtu.dk/services/NutriChem-1.0, a database generated by text mining of 21 million MEDLINE abstracts for information that links plant-based foods with their small molecule components and human disease phenotypes. NutriChem contains text-mined data for 18478 pairs of 1772 plant-based foods and 7898 phytochemicals, and 6242 pairs of 1066 plant-based foods and 751 diseases. In addition, it includes predicted associations for 548 phytochemicals and 252 diseases. To the best of our knowledge this database is the only resource linking the chemical space of plant-based foods with human disease phenotypes and provides a foundation for understanding mechanistically the consequences of eating behaviors on health. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

The importance of quality control in validating concentrations ...

EPA Pesticide Factsheets

A national-scale survey of 247 contaminants of emerging concern (CECs), including organic and inorganic chemical compounds, and microbial contaminants, was conducted in source and treated drinking water samples from 25 treatment plants across the United States. Multiple methods were used to determine these CECs, including six analytical methods to measure 174 pharmaceuticals, personal care products, and pesticides. A three-component quality assurance/quality control (QA/QC) program was designed for the subset of 174 CECs which allowed us to assess and compare performances of the methods used. The three components included: 1) a common field QA/QC protocol and sample design, 2) individual investigator-developed method-specific QA/QC protocols, and 3) a suite of 46 method comparison analytes that were determined in two or more analytical methods. Overall method performance for the 174 organic chemical CECs was assessed by comparing spiked recoveries in reagent, source, and treated water over a two-year period. In addition to the 247 CECs reported in the larger drinking water study, another 48 pharmaceutical compounds measured did not consistently meet predetermined quality standards. Methodologies that did not seem suitable for these analytes are overviewed. The need to exclude analytes based on method performance demonstrates the importance of additional QA/QC protocols. This paper compares the method performance of six analytical methods used to measure 174 emer

Influence of antioxidant rich fresh vegetable juices on starch induced postprandial hyperglycemia in rats.

PubMed

Tiwari, Ashok K; Reddy, K Srikanth; Radhakrishnan, Janani; Kumar, D Anand; Zehra, Amtul; Agawane, Sachin B; Madhusudana, K

2011-09-01

This research analyzed the major chemical components and multiple antioxidant activities present in the fresh juice of eight vegetables, and studied their influence on starch induced postprandial glycemia in rats. A SDS-PAGE based protein fingerprint of each vegetable juice was also prepared. The yields of juice, chemical components like total proteins, total polyphenols, total flavonoids, total anthocyanins and free radicals like the ABTS˙(+) cation, DPPH, H(2)O(2), scavenging activities and reducing properties for NBT and FeCl(3) showed wide variations. Vegetable juice from brinjal ranked first in displaying total antioxidant capacity. Pretreatment of rats with vegetable juices moderated starch induced postprandial glycemia. The fresh juice from the vegetables ridge gourd, bottle gourd, ash gourd and chayote significantly mitigated postprandial hyperglycemic excursion. Total polyphenol concentrations present in vegetable juices positively influenced ABTS˙(+) scavenging activity and total antioxidant capacity. However, NBT reducing activity of juices was positively affected by total protein concentration. Contrarily, however, high polyphenol content in vegetable juice was observed to adversely affect the postprandial antihyperglycemic activity of vegetable juices. This is the first report exploring antihyperglycemic activity in these vegetable juices and highlights the possible adverse influence of high polyphenol content on the antihyperglycemic activity of the vegetable juices. This journal is © The Royal Society of Chemistry 2011

Integrated presentation of ecological risk from multiple stressors

NASA Astrophysics Data System (ADS)

Goussen, Benoit; Price, Oliver R.; Rendal, Cecilie; Ashauer, Roman

2016-10-01

Current environmental risk assessments (ERA) do not account explicitly for ecological factors (e.g. species composition, temperature or food availability) and multiple stressors. Assessing mixtures of chemical and ecological stressors is needed as well as accounting for variability in environmental conditions and uncertainty of data and models. Here we propose a novel probabilistic ERA framework to overcome these limitations, which focusses on visualising assessment outcomes by construct-ing and interpreting prevalence plots as a quantitative prediction of risk. Key components include environmental scenarios that integrate exposure and ecology, and ecological modelling of relevant endpoints to assess the effect of a combination of stressors. Our illustrative results demonstrate the importance of regional differences in environmental conditions and the confounding interactions of stressors. Using this framework and prevalence plots provides a risk-based approach that combines risk assessment and risk management in a meaningful way and presents a truly mechanistic alternative to the threshold approach. Even whilst research continues to improve the underlying models and data, regulators and decision makers can already use the framework and prevalence plots. The integration of multiple stressors, environmental conditions and variability makes ERA more relevant and realistic.

Integrated presentation of ecological risk from multiple stressors.

PubMed

Goussen, Benoit; Price, Oliver R; Rendal, Cecilie; Ashauer, Roman

2016-10-26

Current environmental risk assessments (ERA) do not account explicitly for ecological factors (e.g. species composition, temperature or food availability) and multiple stressors. Assessing mixtures of chemical and ecological stressors is needed as well as accounting for variability in environmental conditions and uncertainty of data and models. Here we propose a novel probabilistic ERA framework to overcome these limitations, which focusses on visualising assessment outcomes by construct-ing and interpreting prevalence plots as a quantitative prediction of risk. Key components include environmental scenarios that integrate exposure and ecology, and ecological modelling of relevant endpoints to assess the effect of a combination of stressors. Our illustrative results demonstrate the importance of regional differences in environmental conditions and the confounding interactions of stressors. Using this framework and prevalence plots provides a risk-based approach that combines risk assessment and risk management in a meaningful way and presents a truly mechanistic alternative to the threshold approach. Even whilst research continues to improve the underlying models and data, regulators and decision makers can already use the framework and prevalence plots. The integration of multiple stressors, environmental conditions and variability makes ERA more relevant and realistic.

Identification of goat milk powder by manufacturer using multiple chemical parameters.

PubMed

McLeod, Rebecca J; Prosser, Colin G; Wakefield, Joshua W

2016-02-01

Concentrations of multiple elements and ratios of stable isotopes of carbon and nitrogen were measured and combined to create a chemical fingerprint of production batches of goat whole milk powder (WMP) produced by different manufacturers. Our objectives were to determine whether or not differences exist in the chemical fingerprint among samples of goat WMP produced at different sites, and assess temporal changes in the chemical fingerprint in product manufactured at one site. In total, 58 samples of goat WMP were analyzed by inductively coupled plasma-mass spectrometry as well as isotope ratio mass spectrometry and a suite of 13 elements (Li, Na, Mg, K, Ca, Mn, Cu, Zn, Rb, Sr, Mo, Cs, and Ba), δ(13)C, and δ(15)N selected to create the chemical fingerprint. Differences in the chemical fingerprint of samples between sites and over time were assessed using principal components analysis and canonical analysis of principal coordinates. Differences in the chemical fingerprints of samples between production sites provided a classification success rate (leave-one-out classification) of 98.1%, providing a basis for using the approach to test the authenticity of product manufactured at a site. Within one site, the chemical fingerprint of samples produced at the beginning of the production season differed from those produced in the middle and late season, driven predominantly by lower concentrations of Na, Mg, K, Mn, and Rb, and higher concentrations of Ba and Cu. This observed temporal variability highlights the importance of obtaining samples from throughout the season to ensure a representative chemical fingerprint is obtained for goat WMP from a single manufacturing site. The reconstitution and spray drying of samples from one manufacturer by the other manufacturer enabled the relative influence of the manufacturing process on the chemical fingerprint to be examined. It was found that such reprocessing altered the chemical fingerprint, although the degree of alteration varied among samples and individual elements. The findings of this study support the use of trace elements and stable isotope ratios to test the authenticity of goat WMP, which can likely be applied to other dairy goat products. This approach could be used test to the factory of origin (and potentially batch of origin) of products in the supply chain, thus providing the ability to audit the supply chain and monitor for fraudulent activity. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Simultaneous acquisition of differing image types

DOEpatents

Demos, Stavros G

2012-10-09

A system in one embodiment includes an image forming device for forming an image from an area of interest containing different image components; an illumination device for illuminating the area of interest with light containing multiple components; at least one light source coupled to the illumination device, the at least one light source providing light to the illumination device containing different components, each component having distinct spectral characteristics and relative intensity; an image analyzer coupled to the image forming device, the image analyzer decomposing the image formed by the image forming device into multiple component parts based on type of imaging; and multiple image capture devices, each image capture device receiving one of the component parts of the image. A method in one embodiment includes receiving an image from an image forming device; decomposing the image formed by the image forming device into multiple component parts based on type of imaging; receiving the component parts of the image; and outputting image information based on the component parts of the image. Additional systems and methods are presented.

Validated Metrics of Quick Flow Improve Assessments of Streamflow Generation Processes at the Long-Term Sleepers River Research Site

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.

2015-12-01

There are multiple approaches to quantify quick flow components of streamflow. Physical hydrograph separations of quick flow using recession analysis (RA) are objective, reproducible, and easily calculated for long-duration streamflow records (years to decades). However, this approach has rarely been validated to have a physical basis for interpretation. In contrast, isotopic hydrograph separation (IHS) and end member mixing analysis using multiple solutes (EMMA) have been used to identify flow components and flowpath routing through catchment soils. Nonetheless, these two approaches are limited by data from limited and isolated periods (hours to weeks) during which more-intensive grab samples were analyzed. These limitations oftentimes make IHS and EMMA difficult to generalize beyond brief windows of time. At the Sleepers River Research Watershed (SRRW) in northern Vermont, USA, we have data from multiple snowmelt events over a two decade period and from multiple nested catchments to assess relationships among RA, IHS, and EMMA. Quick flow separations were highly correlated among the three techniques, which shows links among metrics of quick flow, water sources, and flow path routing in a small (41 ha), forested catchment (W-9) The similarity in responses validates a physical interpretation for a particular RA approach (the Ekhardt recursive RA filter). This validation provides a new tool to estimate new water inputs and flowpath routing for more and longer periods when chemical or isotopic tracers may not have been measured. At three other SRRW catchments, we found similar strong correlations among the three techniques. Consistent responses across four catchments provide evidence to support other research at the SRRW that shows that runoff generation mechanisms are similar despite differences in catchment sizes and land covers.

Active nematic emulsions

PubMed Central

Hardoüin, Jérôme; Sagués, Francesc

2018-01-01

The formation of emulsions from multiple immiscible fluids is governed by classical concepts such as surface tension, differential chemical affinity and viscosity, and the action of surface-active agents. Much less is known about emulsification when one of the components is active and thus inherently not constrained by the laws of thermodynamic equilibrium. We demonstrate one such realization consisting in the encapsulation of an active liquid crystal (LC)–like gel, based on microtubules and kinesin molecular motors, into a thermotropic LC. These active nematic emulsions exhibit a variety of dynamic behaviors that arise from the cross-talk between topological defects separately residing in the active and passive components. Using numerical simulations, we show a feedback mechanism by which active flows continuously drive the passive defects that, in response, resolve the otherwise degenerated trajectories of the active defects. Our experiments show that the choice of surfactant, which stabilizes the active/passive interface, allows tuning the regularity of the self-sustained dynamic events. The hybrid active-passive system demonstrated here provides new perspectives for dynamic self-assembly driven by an active material but regulated by the equilibrium properties of the passive component. PMID:29740605

Active nematic emulsions.

PubMed

Guillamat, Pau; Kos, Žiga; Hardoüin, Jérôme; Ignés-Mullol, Jordi; Ravnik, Miha; Sagués, Francesc

2018-04-01

The formation of emulsions from multiple immiscible fluids is governed by classical concepts such as surface tension, differential chemical affinity and viscosity, and the action of surface-active agents. Much less is known about emulsification when one of the components is active and thus inherently not constrained by the laws of thermodynamic equilibrium. We demonstrate one such realization consisting in the encapsulation of an active liquid crystal (LC)-like gel, based on microtubules and kinesin molecular motors, into a thermotropic LC. These active nematic emulsions exhibit a variety of dynamic behaviors that arise from the cross-talk between topological defects separately residing in the active and passive components. Using numerical simulations, we show a feedback mechanism by which active flows continuously drive the passive defects that, in response, resolve the otherwise degenerated trajectories of the active defects. Our experiments show that the choice of surfactant, which stabilizes the active/passive interface, allows tuning the regularity of the self-sustained dynamic events. The hybrid active-passive system demonstrated here provides new perspectives for dynamic self-assembly driven by an active material but regulated by the equilibrium properties of the passive component.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferraro, F. R.; Dalessandro, E.; Lanzoni, B.

The Galactic bulge is dominated by an old, metal-rich stellar population. The possible presence and the amount of a young (a few gigayears old) minor component is one of the major issues debated in the literature. Recently, the bulge stellar system Terzan 5 was found to harbor three sub-populations with iron content varying by more than one order of magnitude (from 0.2 up to two times the solar value), with chemical abundance patterns strikingly similar to those observed in bulge field stars. Here we report on the detection of two distinct main-sequence turnoff points in Terzan 5, providing the agemore » of the two main stellar populations: 12 Gyr for the (dominant) sub-solar component and 4.5 Gyr for the component at super-solar metallicity. This discovery classifies Terzan 5 as a site in the Galactic bulge where multiple bursts of star formation occurred, thus suggesting a quite massive progenitor possibly resembling the giant clumps observed in star-forming galaxies at high redshifts. This connection opens a new route of investigation into the formation process and evolution of spheroids and their stellar content.« less

Multi-enzyme complexes on DNA scaffolds capable of substrate channelling with an artificial swinging arm

NASA Astrophysics Data System (ADS)

Fu, Jinglin; Yang, Yuhe Renee; Johnson-Buck, Alexander; Liu, Minghui; Liu, Yan; Walter, Nils G.; Woodbury, Neal W.; Yan, Hao

2014-07-01

Swinging arms are a key functional component of multistep catalytic transformations in many naturally occurring multi-enzyme complexes. This arm is typically a prosthetic chemical group that is covalently attached to the enzyme complex via a flexible linker, allowing the direct transfer of substrate molecules between multiple active sites within the complex. Mimicking this method of substrate channelling outside the cellular environment requires precise control over the spatial parameters of the individual components within the assembled complex. DNA nanostructures can be used to organize functional molecules with nanoscale precision and can also provide nanomechanical control. Until now, protein-DNA assemblies have been used to organize cascades of enzymatic reactions by controlling the relative distance and orientation of enzymatic components or by facilitating the interface between enzymes/cofactors and electrode surfaces. Here, we show that a DNA nanostructure can be used to create a multi-enzyme complex in which an artificial swinging arm facilitates hydride transfer between two coupled dehydrogenases. By exploiting the programmability of DNA nanostructures, key parameters including position, stoichiometry and inter-enzyme distance can be manipulated for optimal activity.

Multi-enzyme complexes on DNA scaffolds capable of substrate channelling with an artificial swinging arm.

PubMed

Fu, Jinglin; Yang, Yuhe Renee; Johnson-Buck, Alexander; Liu, Minghui; Liu, Yan; Walter, Nils G; Woodbury, Neal W; Yan, Hao

2014-07-01

Swinging arms are a key functional component of multistep catalytic transformations in many naturally occurring multi-enzyme complexes. This arm is typically a prosthetic chemical group that is covalently attached to the enzyme complex via a flexible linker, allowing the direct transfer of substrate molecules between multiple active sites within the complex. Mimicking this method of substrate channelling outside the cellular environment requires precise control over the spatial parameters of the individual components within the assembled complex. DNA nanostructures can be used to organize functional molecules with nanoscale precision and can also provide nanomechanical control. Until now, protein-DNA assemblies have been used to organize cascades of enzymatic reactions by controlling the relative distance and orientation of enzymatic components or by facilitating the interface between enzymes/cofactors and electrode surfaces. Here, we show that a DNA nanostructure can be used to create a multi-enzyme complex in which an artificial swinging arm facilitates hydride transfer between two coupled dehydrogenases. By exploiting the programmability of DNA nanostructures, key parameters including position, stoichiometry and inter-enzyme distance can be manipulated for optimal activity.

Non-destructive evaluation of chlorophyll content in quinoa and amaranth leaves by simple and multiple regression analysis of RGB image components.

PubMed

Riccardi, M; Mele, G; Pulvento, C; Lavini, A; d'Andria, R; Jacobsen, S-E

2014-06-01

Leaf chlorophyll content provides valuable information about physiological status of plants; it is directly linked to photosynthetic potential and primary production. In vitro assessment by wet chemical extraction is the standard method for leaf chlorophyll determination. This measurement is expensive, laborious, and time consuming. Over the years alternative methods, rapid and non-destructive, have been explored. The aim of this work was to evaluate the applicability of a fast and non-invasive field method for estimation of chlorophyll content in quinoa and amaranth leaves based on RGB components analysis of digital images acquired with a standard SLR camera. Digital images of leaves from different genotypes of quinoa and amaranth were acquired directly in the field. Mean values of each RGB component were evaluated via image analysis software and correlated to leaf chlorophyll provided by standard laboratory procedure. Single and multiple regression models using RGB color components as independent variables have been tested and validated. The performance of the proposed method was compared to that of the widely used non-destructive SPAD method. Sensitivity of the best regression models for different genotypes of quinoa and amaranth was also checked. Color data acquisition of the leaves in the field with a digital camera was quick, more effective, and lower cost than SPAD. The proposed RGB models provided better correlation (highest R (2)) and prediction (lowest RMSEP) of the true value of foliar chlorophyll content and had a lower amount of noise in the whole range of chlorophyll studied compared with SPAD and other leaf image processing based models when applied to quinoa and amaranth.

Advanced Fingerprint Analysis Project Fingerprint Constituents

DOE Office of Scientific and Technical Information (OSTI.GOV)

GM Mong; CE Petersen; TRW Clauss

The work described in this report was focused on generating fundamental data on fingerprint components which will be used to develop advanced forensic techniques to enhance fluorescent detection, and visualization of latent fingerprints. Chemical components of sweat gland secretions are well documented in the medical literature and many chemical techniques are available to develop latent prints, but there have been no systematic forensic studies of fingerprint sweat components or of the chemical and physical changes these substances undergo over time.

Characterization of the pharmacokinetics of gasoline using PBPK modeling with a complex mixtures chemical lumping approach.

PubMed

Dennison, James E; Andersen, Melvin E; Yang, Raymond S H

2003-09-01

Gasoline consists of a few toxicologically significant components and a large number of other hydrocarbons in a complex mixture. By using an integrated, physiologically based pharmacokinetic (PBPK) modeling and lumping approach, we have developed a method for characterizing the pharmacokinetics (PKs) of gasoline in rats. The PBPK model tracks selected target components (benzene, toluene, ethylbenzene, o-xylene [BTEX], and n-hexane) and a lumped chemical group representing all nontarget components, with competitive metabolic inhibition between all target compounds and the lumped chemical. PK data was acquired by performing gas uptake PK studies with male F344 rats in a closed chamber. Chamber air samples were analyzed every 10-20 min by gas chromatography/flame ionization detection and all nontarget chemicals were co-integrated. A four-compartment PBPK model with metabolic interactions was constructed using the BTEX, n-hexane, and lumped chemical data. Target chemical kinetic parameters were refined by studies with either the single chemical alone or with all five chemicals together. o-Xylene, at high concentrations, decreased alveolar ventilation, consistent with respiratory irritation. A six-chemical interaction model with the lumped chemical group was used to estimate lumped chemical partitioning and metabolic parameters for a winter blend of gasoline with methyl t-butyl ether and a summer blend without any oxygenate. Computer simulation results from this model matched well with experimental data from single chemical, five-chemical mixture, and the two blends of gasoline. The PBPK model analysis indicated that metabolism of individual components was inhibited up to 27% during the 6-h gas uptake experiments of gasoline exposures.

Estrogen and androgen receptor activities of hydraulic fracturing chemicals and surface and ground water in a drilling-dense region

USGS Publications Warehouse

Kassotis, Christopher D.; Tillitt, Donald E.; Davis, J. Wade; Hormann, Anette M.; Nagel, Susan C.

2014-01-01

The rapid rise in natural gas extraction using hydraulic fracturing increases the potential for contamination of surface and ground water from chemicals used throughout the process. Hundreds of products containing more than 750 chemicals and components are potentially used throughout the extraction process, including more than 100 known or suspected endocrine-disrupting chemicals. We hypothesized thataselected subset of chemicalsusedin natural gas drilling operationsandalso surface and ground water samples collected in a drilling-dense region of Garfield County, Colorado, would exhibit estrogen and androgen receptor activities. Water samples were collected, solid-phase extracted, and measured for estrogen and androgen receptor activities using reporter gene assays in human cell lines. Of the 39 unique water samples, 89%, 41%, 12%, and 46% exhibited estrogenic, antiestrogenic, androgenic, and antiandrogenic activities, respectively. Testing of a subset of natural gas drilling chemicals revealed novel antiestrogenic, novel antiandrogenic, and limited estrogenic activities. The Colorado River, the drainage basin for this region, exhibited moderate levels of estrogenic, antiestrogenic, and antiandrogenic activities, suggesting that higher localized activity at sites with known natural gas–related spills surrounding the river might be contributing to the multiple receptor activities observed in this water source. The majority of water samples collected from sites in a drilling-dense region of Colorado exhibited more estrogenic, antiestrogenic, or antiandrogenic activities than reference sites with limited nearby drilling operations. Our data suggest that natural gas drilling operationsmayresult in elevated endocrine-disrupting chemical activity in surface and ground water.

CHEMICAL DIAGNOSTICS OF THE MASSIVE STAR CLUSTER-FORMING CLOUD G33.92+0.11. I. {sup 13}CS, CH{sub 3}OH, CH{sub 3}N, OCS, H{sub 2}S, SO{sub 2}, and SiO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Minh, Young Chol; Liu, Hauyu Baobab; Galvań-Madrid, Roberto

2016-06-20

Large chemical diversity was found in the gas clumps associated with the massive star cluster-forming G33.92+0.11 region with sub-arcsecond angular resolution (0.″6–0.″8) observations with ALMA. The most prominent gas clumps are associated with the dust emission peaks A1, A2, and A5. The close correlation between CH{sub 3}OH and OCS in the emission distributions strongly suggests that these species share a common origin of hot core grain mantle evaporation. The latest generation of star clusters are forming in the A5 clump, as indicated by multiple SiO outflows and its rich hot core chemistry. We also found a narrow SiO emission associatedmore » with the outflows, which may trace a cooled component of the outflows. Part of the chemical complexity may have resulted from the accreting gas from the ambient clouds, especially in the northern part of A1 and the southern part of A2. The chemical diversity found in this region is believed to mainly result from the different chemical evolutionary timescales of massive star formation. In particular, the abundance ratio between CH{sub 3}OH and CH{sub 3}CN may be a good chemical clock for the early phase of star formation.« less

Chemical Analysis of Water-accommodated Fractions of Crude Oil Spills Using TIMS-FT-ICR MS.

PubMed

Benigni, Paolo; Marin, Rebecca; Sandoval, Kathia; Gardinali, Piero; Fernandez-Lima, Francisco

2017-03-03

Multiple chemical processes control how crude oil is incorporated into seawater and also the chemical reactions that occur overtime. Studying this system requires the careful preparation of the sample in order to accurately replicate the natural formation of the water-accommodated fraction that occurs in nature. Low-energy water-accommodated fractions (LEWAF) are carefully prepared by mixing crude oil and water at a set ratio. Aspirator bottles are then irradiated, and at set time points, the water is sampled and extracted using standard techniques. A second challenge is the representative characterization of the sample, which must take into consideration the chemical changes that occur over time. A targeted analysis of the aromatic fraction of the LEWAF can be performed using an atmospheric-pressure laser ionization source coupled to a custom-built trapped ion mobility spectrometry-Fourier transform-ion cyclotron resonance mass spectrometer (TIMS-FT-ICR MS). The TIMS-FT-ICR MS analysis provides high-resolution ion mobility and ultrahigh-resolution MS analysis, which further allow the identification of isomeric components by their collision cross-sections (CCS) and chemical formula. Results show that as the oil-water mixture is exposed to light, there is significant photo-solubilization of the surface oil into the water. Over time, the chemical transformation of the solubilized molecules takes place, with a decrease in the number of identifications of nitrogen- and sulfur-bearing species in favor of those with a greater oxygen content than were typically observed in the base oil.

Chemical composition of fingerprints for gender determination.

PubMed

Asano, Keiji G; Bayne, Charles K; Horsman, Katie M; Buchanan, Michelle V

2002-07-01

This work investigates the chemical nature of fingerprints to ascertain whether differences in chemical composition or the existence of chemical markers can be used to determine personal traits, such as age, gender, and personal habits. This type of information could be useful for reducing the pool of potential suspects in criminal investigations when latent fingerprints are unsuitable for comparison by traditional methods. Fingertip residue that has been deposited onto a bead was extracted with a solvent such as chloroform. Samples were analyzed by gas chromatography/mass spectrometry (GC/MS). The chemical components identified include fatty acids, long chain fatty acid esters, cholesterol and squalene. The area ratios of ten selected components relative to squalene were calculated for a small preliminary experiment that showed a slight gender difference for three of these components. However, when the experiment was repeated with a larger, statistically designed experiment no significant differences between genders were detected for any of the component ratios. The multivariate Hotelling's T2 test that tested all ten-component ratios simultaneously also showed no gender differences at the 5% significance level.

Is Stacking Intervention Components Cost-Effective? An Analysis of the Incredible Years Program

ERIC Educational Resources Information Center

Foster, E. Michael; Olchowski, Allison E.; Webster-Stratton, Carolyn H.

2007-01-01

The cost-effectiveness of delivering stacked multiple intervention components for children is compared to implementing single intervention by analyzing the Incredible Years Series program. The result suggests multiple intervention components are more cost-effective than single intervention components.

Synthesis of monolithic graphene – graphite integrated electronics

PubMed Central

Park, Jang-Ung; Nam, SungWoo; Lee, Mi-Sun; Lieber, Charles M.

2013-01-01

Encoding electronic functionality into nanoscale elements during chemical synthesis has been extensively explored over the past decade as the key to developing integrated nanosystems1 with functions defined by synthesis2-6. Graphene7-12 has been recently explored as a two-dimensional nanoscale material, and has demonstrated simple device functions based on conventional top-down fabrication13-20. However, the synthetic approach to encoding electronic functionality and thus enabling an entire integrated graphene electronics in a chemical synthesis had not previously been demonstrated. Here we report an unconventional approach for the synthesis of monolithically-integrated electronic devices based on graphene and graphite. Spatial patterning of heterogeneous catalyst metals permits the selective growth of graphene and graphite, with controlled number of graphene layers. Graphene transistor arrays with graphitic electrodes and interconnects were formed from synthesis. These functional, all-carbon structures were transferrable onto a variety of substrates. The integrated transistor arrays were used to demonstrate real-time, multiplexed chemical sensing, and more significantly, multiple carbon layers of the graphene-graphite device components were vertically assembled to form a three-dimensional flexible structure which served as a top-gate transistor array. These results represent a substantial progress towards encoding electronic functionality via chemical synthesis and suggest future promise for one-step integration of graphene-graphite based electronics. PMID:22101813

Synthesis of monolithic graphene-graphite integrated electronics.

PubMed

Park, Jang-Ung; Nam, SungWoo; Lee, Mi-Sun; Lieber, Charles M

2011-11-20

Encoding electronic functionality into nanoscale elements during chemical synthesis has been extensively explored over the past decade as the key to developing integrated nanosystems with functions defined by synthesis. Graphene has been recently explored as a two-dimensional nanoscale material, and has demonstrated simple device functions based on conventional top-down fabrication. However, the synthetic approach to encoding electronic functionality and thus enabling an entire integrated graphene electronics in a chemical synthesis had not previously been demonstrated. Here we report an unconventional approach for the synthesis of monolithically integrated electronic devices based on graphene and graphite. Spatial patterning of heterogeneous metal catalysts permits the selective growth of graphene and graphite, with a controlled number of graphene layers. Graphene transistor arrays with graphitic electrodes and interconnects were formed from the synthesis. These functional, all-carbon structures were transferable onto a variety of substrates. The integrated transistor arrays were used to demonstrate real-time, multiplexed chemical sensing and more significantly, multiple carbon layers of the graphene-graphite device components were vertically assembled to form a three-dimensional flexible structure which served as a top-gate transistor array. These results represent substantial progress towards encoding electronic functionality through chemical synthesis and suggest the future promise of one-step integration of graphene-graphite based electronics.

From the exposome to mechanistic understanding of chemical ...

EPA Pesticide Factsheets

BACKGROUND: Current definitions of the exposome expand beyond the initial idea to consider the totality of exposure and aim to relate to biological effects. While the exposome has been established for human health, its principles can be extended to include broader ecological issues. The assessment of exposure is tightly interlinked with hazard assessment. OBJECTIVES: We explore if mechanistic understanding of the causal links between exposure and adverse effects on human health and the environment can be improved by integrating the exposome approach with the adverse outcome pathway (AOP) concept - a framework to structure and organize the sequence of toxicological events from an initial molecular interaction of a chemical to an adverse outcome.METHODS: This review was informed by a Workshop organized by the Integrated Project EXPOSOME at the UFZ Helmholtz Centre for Environmental Research in Leipzig, Germany. DISCUSSION: The exposome encompasses all chemicals, including exogenous chemicals and endogenous compounds that are produced in response to external factors. By complementing the exposome research with the AOP concept, we can achieve a better mechanistic understanding, weigh the importance of various components of the exposome, and determine primary risk drivers. The ability to interpret multiple exposures and mixture effects at the mechanistic level requires a more holistic approach facilitated by the exposome concept.CONCLUSION: Incorporating the AOP conc

Responsive polymer-based colloids for drug delivery and bioconversion

NASA Astrophysics Data System (ADS)

Kudina, Olena

Responsive polymer-based colloids (RPBC) are the colloidal structures containing responsive polymeric component which is able to adapt its physico-chemical properties to the environment by undergoing chemical and/or conformational changes. The goal of the dissertation is to develop and characterize several groups of RPBC with different morphological complexity and explore their potential in drug delivery and bioconversion. The role of RPBC morphology for these specific applications is discussed in details. Three groups of RPBC were fabricated: i. polymeric micelles; ii. mixed polymeric micelles; iii. hybrid polymer-inorganic particles. All fabricated RPBCs contain polymeric component in their structure. The dissertation investigates how the changes of the responsive polymeric component properties are reflected in morphologies of RPBC. The first group of RPBC, polymeric micelles, was formed by the self-assembly of amphiphilic invertible polymers (AIPs) synthesized in our group. AIPs self-assemble into invertible micellar assemblies (IMAs) in solvents of different polarity. In this work, IMAs ability to invert the structure as a response to the change in solvent polarity was demonstrated using 1H NMR spectroscopy and SANS. It was shown that the IMAs incorporate hydrophobic cargo either in the core or in the shell, depending on the chemical structure of cargo molecules. Following in vitro study demonstrates that loaded with drug (curcumin) IMAs are cytotoxic to osteosarcoma cells. Mixed polymeric micelles represent another, more complex, RPBC morphologies studied in the dissertation. Mixed micelles were fabricated from AIPs and amphiphilic oligomers synthesized from pyromellitic dianhydride, polyethylene glycol methyl ethers, and alkanols/cholesterol. The combination of selected AIP and oligomers based on cholesterol results in mixed micelles with an increased drug-loading capacity (from 10% w/w loaded curcumin in single component IMAs to 26%w/w in mixed micelles). Even more complex colloids are hybrid polymer-inorganic particles, the third RPBC group studied in dissertation. Material was designed as core--shell particles with superparamagnetic core engulfed by grafted polymer brushes. These particles were loaded with enzymes (cellulases), thus, are turned into enzymogels for cellulose bioconversion. The study demonstrates that such RPBCs can be used multiple times during hydrolysis and provide an about four-fold increase in glucose production in comparison to free enzymes.

Insights into the molecular mechanisms of Polygonum multiflorum Thunb-induced liver injury: a computational systems toxicology approach.

PubMed

Wang, Yin-Yin; Li, Jie; Wu, Zeng-Rui; Zhang, Bo; Yang, Hong-Bin; Wang, Qin; Cai, Ying-Chun; Liu, Gui-Xia; Li, Wei-Hua; Tang, Yun

2017-05-01

An increasing number of cases of herb-induced liver injury (HILI) have been reported, presenting new clinical challenges. In this study, taking Polygonum multiflorum Thunb (PmT) as an example, we proposed a computational systems toxicology approach to explore the molecular mechanisms of HILI. First, the chemical components of PmT were extracted from 3 main TCM databases as well as the literature related to natural products. Then, the known targets were collected through data integration, and the potential compound-target interactions (CTIs) were predicted using our substructure-drug-target network-based inference (SDTNBI) method. After screening for hepatotoxicity-related genes by assessing the symptoms of HILI, a compound-target interaction network was constructed. A scoring function, namely, Ascore, was developed to estimate the toxicity of chemicals in the liver. We conducted network analysis to determine the possible mechanisms of the biphasic effects using the analysis tools, including BiNGO, pathway enrichment, organ distribution analysis and predictions of interactions with CYP450 enzymes. Among the chemical components of PmT, 54 components with good intestinal absorption were used for analysis, and 2939 CTIs were obtained. After analyzing the mRNA expression data in the BioGPS database, 1599 CTIs and 125 targets related to liver diseases were identified. In the top 15 compounds, seven with Ascore values >3000 (emodin, quercetin, apigenin, resveratrol, gallic acid, kaempferol and luteolin) were obviously associated with hepatotoxicity. The results from the pathway enrichment analysis suggest that multiple interactions between apoptosis and metabolism may underlie PmT-induced liver injury. Many of the pathways have been verified in specific compounds, such as glutathione metabolism, cytochrome P450 metabolism, and the p53 pathway, among others. Hepatitis symptoms, the perturbation of nine bile acids and yellow or tawny urine also had corresponding pathways, justifying our method. In conclusion, this computational systems toxicology method reveals possible toxic components and could be very helpful for understanding the mechanisms of HILI. In this way, the method might also facilitate the identification of novel hepatotoxic herbs.

Multiple reaction monitoring (MRM)-profiling for biomarker discovery applied to human polycystic ovarian syndrome.

PubMed

Cordeiro, Fernanda B; Ferreira, Christina R; Sobreira, Tiago Jose P; Yannell, Karen E; Jarmusch, Alan K; Cedenho, Agnaldo P; Lo Turco, Edson G; Cooks, R Graham

2017-09-15

We describe multiple reaction monitoring (MRM)-profiling, which provides accelerated discovery of discriminating molecular features, and its application to human polycystic ovary syndrome (PCOS) diagnosis. The discovery phase of the MRM-profiling seeks molecular features based on some prior knowledge of the chemical functional groups likely to be present in the sample. It does this through use of a limited number of pre-chosen and chemically specific neutral loss and/or precursor ion MS/MS scans. The output of the discovery phase is a set of precursor/product transitions. In the screening phase these MRM transitions are used to interrogate multiple samples (hence the name MRM-profiling). MRM-profiling was applied to follicular fluid samples of 22 controls and 29 clinically diagnosed PCOS patients. Representative samples were delivered by flow injection to a triple quadrupole mass spectrometer set to perform a number of pre-chosen and chemically specific neutral loss and/or precursor ion MS/MS scans. The output of this discovery phase was a set of 1012 precursor/product transitions. In the screening phase each individual sample was interrogated for these MRM transitions. Principal component analysis (PCA) and receiver operating characteristic (ROC) curves were used for statistical analysis. To evaluate the method's performance, half the samples were used to build a classification model (testing set) and half were blinded (validation set). Twenty transitions were used for the classification of the blind samples, most of them (N = 19) showed lower abundances in the PCOS group and corresponded to phosphatidylethanolamine (PE) and phosphatidylserine (PS) lipids. Agreement of 73% with clinical diagnosis was found when classifying the 26 blind samples. MRM-profiling is a supervised method characterized by its simplicity, speed and the absence of chromatographic separation. It can be used to rapidly isolate discriminating molecules in healthy/disease conditions by tailored screening of signals associated with hundreds of molecules in complex samples. Copyright © 2017 John Wiley & Sons, Ltd.

Minimal 2'-O-methyl phosphorothioate linkage modification pattern of synthetic guide RNAs for increased stability and efficient CRISPR-Cas9 gene editing avoiding cellular toxicity

PubMed Central

Basila, Megan; Kelley, Melissa L.

2017-01-01

Since its initial application in mammalian cells, CRISPR-Cas9 has rapidly become a preferred method for genome engineering experiments. The Cas9 nuclease is targeted to genomic DNA using guide RNAs (gRNA), either as the native dual RNA system consisting of a DNA-targeting CRISPR RNA (crRNA) and a trans-activating crRNA (tracrRNA), or as a chimeric single guide RNA (sgRNA). Entirely DNA-free CRISPR-Cas9 systems using either Cas9 protein or Cas9 mRNA and chemically synthesized gRNAs allow for transient expression of CRISPR-Cas9 components, thereby reducing the potential for off-targeting, which is a significant advantage in therapeutic applications. In addition, the use of synthetic gRNA allows for the incorporation of chemical modifications for enhanced properties including improved stability. Previous studies have demonstrated the utility of chemically modified gRNAs, but have focused on one pattern with multiple modifications in co-electroporation with Cas9 mRNA or multiple modifications and patterns with Cas9 plasmid lipid co-transfections. Here we present gene editing results using a series of chemically modified synthetic sgRNA molecules and chemically modified crRNA:tracrRNA molecules in both electroporation and lipid transfection assessing indel formation and/or phenotypic gene knockout. We show that while modifications are required for co-electroporation with Cas9 mRNA, some modification patterns of the gRNA are toxic to cells compared to the unmodified gRNA and most modification patterns do not significantly improve gene editing efficiency. We also present modification patterns of the gRNA that can modestly improve Cas9 gene editing efficiency when co-transfected with Cas9 mRNA or Cas9 protein (> 1.5-fold difference). These results indicate that for certain applications, including those relevant to primary cells, the incorporation of some, but not all chemical modification patterns on synthetic crRNA:tracrRNA or sgRNA can be beneficial to CRISPR-Cas9 gene editing. PMID:29176845

Minimal 2'-O-methyl phosphorothioate linkage modification pattern of synthetic guide RNAs for increased stability and efficient CRISPR-Cas9 gene editing avoiding cellular toxicity.

PubMed

Basila, Megan; Kelley, Melissa L; Smith, Anja van Brabant

2017-01-01

Since its initial application in mammalian cells, CRISPR-Cas9 has rapidly become a preferred method for genome engineering experiments. The Cas9 nuclease is targeted to genomic DNA using guide RNAs (gRNA), either as the native dual RNA system consisting of a DNA-targeting CRISPR RNA (crRNA) and a trans-activating crRNA (tracrRNA), or as a chimeric single guide RNA (sgRNA). Entirely DNA-free CRISPR-Cas9 systems using either Cas9 protein or Cas9 mRNA and chemically synthesized gRNAs allow for transient expression of CRISPR-Cas9 components, thereby reducing the potential for off-targeting, which is a significant advantage in therapeutic applications. In addition, the use of synthetic gRNA allows for the incorporation of chemical modifications for enhanced properties including improved stability. Previous studies have demonstrated the utility of chemically modified gRNAs, but have focused on one pattern with multiple modifications in co-electroporation with Cas9 mRNA or multiple modifications and patterns with Cas9 plasmid lipid co-transfections. Here we present gene editing results using a series of chemically modified synthetic sgRNA molecules and chemically modified crRNA:tracrRNA molecules in both electroporation and lipid transfection assessing indel formation and/or phenotypic gene knockout. We show that while modifications are required for co-electroporation with Cas9 mRNA, some modification patterns of the gRNA are toxic to cells compared to the unmodified gRNA and most modification patterns do not significantly improve gene editing efficiency. We also present modification patterns of the gRNA that can modestly improve Cas9 gene editing efficiency when co-transfected with Cas9 mRNA or Cas9 protein (> 1.5-fold difference). These results indicate that for certain applications, including those relevant to primary cells, the incorporation of some, but not all chemical modification patterns on synthetic crRNA:tracrRNA or sgRNA can be beneficial to CRISPR-Cas9 gene editing.

Flow method and apparatus for screening chemicals using micro x-ray fluorescence

DOEpatents

Warner, Benjamin P [Los Alamos, NM; Havrilla, George J [Los Alamos, NM; Miller, Thomasin C [Bartlesville, OK; Lewis, Cris [Los Alamos, NM; Mahan, Cynthia A [Los Alamos, NM; Wells, Cyndi A [Los Alamos, NM

2009-04-14

Method and apparatus for screening chemicals using micro x-ray fluorescence. A method for screening a mixture of potential pharmaceutical chemicals for binding to at least one target binder involves flow-separating a solution of chemicals and target binders into separated components, exposing them to an x-ray excitation beam, detecting x-ray fluorescence signals from the components, and determining from the signals whether or not a binding event between a chemical and target binder has occurred.

Flow method and apparatus for screening chemicals using micro x-ray fluorescence

DOEpatents

Warner, Benjamin P [Los Alamos, NM; Havrilla, George J [Los Alamos, NM; Miller, Thomasin C [Bartlesville, OK; Lewis, Cris [Los Alamos, NM; Mahan, Cynthia A [Los Alamos, NM; Wells, Cyndi A [Los Alamos, NM

2011-04-26

Method and apparatus for screening chemicals using micro x-ray fluorescence. A method for screening a mixture of potential pharmaceutical chemicals for binding to at least one target binder involves flow separating a solution of chemicals and target binders into separated components, exposing them to an x-ray excitation beam, detecting x-ray fluorescence signals from the components, and determining from the signals whether or not a binding event between a chemical and target binder has occurred.

Association between particulate matter and its chemical constituents of urban air pollution and daily mortality or morbidity in Beijing City.

PubMed

Li, Pei; Xin, Jinyuan; Wang, Yuesi; Li, Guoxing; Pan, Xiaochuan; Wang, Shigong; Cheng, Mengtian; Wen, Tianxue; Wang, Guangcheng; Liu, Zirui

2015-01-01

Recent time series studies have indicated that daily mortality and morbidity are associated with particulate matters. However, about the relative effects and its seasonal patterns of fine particulate matter constituents is particularly limited in developing Asian countries. In this study, we examined the role of particulate matters and its key chemical components of fine particles on both mortality and morbidity in Beijing. We applied several overdispersed Poisson generalized nonlinear models, adjusting for time, day of week, holiday, temperature, and relative humidity, to investigate the association between risk of mortality or morbidity and particulate matters and its constituents in Beijing, China, for January 2005 through December 2009. Particles and several constituents were associated with multiple mortality or morbidity categories, especially on respiratory health. For a 3-day lag, the nonaccident mortality increased by 1.52, 0.19, 1.03, 0.56, 0.42, and 0.32% for particulate matter (PM)2.5, PM10, K(+), SO4(2-), Ca(2+), and NO3(-) based on interquartile ranges of 36.00, 64.00, 0.41, 8.75, 1.43, and 2.24 μg/m(3), respectively. The estimates of short-term effects for PM2.5 and its components in the cold season were 1 ~ 6 times higher than that in the full year on these health outcomes. Most of components had stronger adverse effects on human health in the heavy PM2.5 mass concentrations, especially for K(+), NO3(-), and SO4(2-). This analysis added to the growing body of evidence linking PM2.5 with mortality or morbidity and indicated that excess risks may vary among specific PM2.5 components. Combustion-related products, traffic sources, vegetative burning, and crustal component and resuspended road dust may play a key role in the associations between air pollution and public health in Beijing.

Environmental stress-corrosion cracking of fiberglass: lessons learned from failures in the chemical industry.

PubMed

Myers, T J; Kytömaa, H K; Smith, T R

2007-04-11

Fiberglass reinforced plastic (FRP) composite materials are often used to construct tanks, piping, scrubbers, beams, grating, and other components for use in corrosive environments. While FRP typically offers superior and cost effective corrosion resistance relative to other construction materials, the glass fibers traditionally used to provide the structural strength of the FRP can be susceptible to attack by the corrosive environment. The structural integrity of traditional FRP components in corrosive environments is usually dependent on the integrity of a corrosion-resistant barrier, such as a resin-rich layer containing corrosion resistant glass fibers. Without adequate protection, FRP components can fail under loads well below their design by an environmental stress-corrosion cracking (ESCC) mechanism when simultaneously exposed to mechanical stress and a corrosive chemical environment. Failure of these components can result in significant releases of hazardous substances into plants and the environment. In this paper, we present two case studies where fiberglass components failed due to ESCC at small chemical manufacturing facilities. As is often typical, the small chemical manufacturing facilities relied largely on FRP component suppliers to determine materials appropriate for the specific process environment and to repair damaged in-service components. We discuss the lessons learned from these incidents and precautions companies should take when interfacing with suppliers and other parties during the specification, design, construction, and repair of FRP components in order to prevent similar failures and chemical releases from occurring in the future.

CH 4/NH 3/H 2O spark tholin: Chemical analysis and interaction with Jovian aqueous clouds

NASA Astrophysics Data System (ADS)

McDonald, Gene D.; Khare, Bishun N.; Reid Thompson, W.; Sagan, Carl

1991-12-01

The organic solid (tholin) produced by spark discharge in a CH 4 + NH 3 + H 2O atmosphere is investigated, along with the separable components of its water-soluble fraction. The chemistry of this material serves as a provisional model for the interaction of Jovian organic heteropolymers with the deep aqueous clouds of Jupiter. Intact (unhydrolyzed) tholin is resolved into four chemically distinct fractions by high-pressure liquid chromatography (HPLC). Gel filtration chromatography reveals abundant components at molecular weights ⋍600-700 and 200-300 Da. Gas chromatography/mass spectrometry of derivatized hydrolysis products of unfractionated tholin shows about 10% by mass protein and nonprotein amino acids, chiefly glycine, alanine, aspartic acid, β-alanine, and β-aminobutyric acid, and 12% by mass other organic acids and hydroxy acids. The stereospecificity of alanine is investigated and shown to be racemic. The four principal HPLC fractions yield distinctly different proportions of amino acids. Chemical tests show that small peptides or organic molecules containing multiple amino acid precursors are a possibility in the intact tholins, but substantial quantities of large peptides are not indicated. Candidate 700-Da molecules have a central unsaturated, hydrocarbon- and nitrile-rich core, linked by acid-labile (ester or amide) bonds to amino acid and carboxylic acid side groups. The core is probably not HCN "polymer." The concentration of amino acids from tholin hydrolysis in the lower aqueous clouds of Jupiter, about 0.1 μ M, is enough to maintain small populations of terrestrial microorganisms even if the amino acids must serve as the sole carbon source.

Porous multi-component material for the capture and separation of species of interest

DOEpatents

Addleman, Raymond S.; Chouyyok, Wilaiwan; Li, Xiaohong S.; Cinson, Anthony D.; Gerasimenko, Aleksandr A

2016-06-21

A method and porous multi-component material for the capture, separation or chemical reaction of a species of interest is disclosed. The porous multi-component material includes a substrate and a composite thin film. The composite thin film is formed by combining a porous polymer with a nanostructured material. The nanostructured material may include a surface chemistry for the capture of chemicals or particles. The composite thin film is coupled to the support or device surface. The method and material provides a simple, fast, and chemically and physically benign way to integrate nanostructured materials into devices while preserving their chemical activity.

Petrographic and Geochemical Investigation of Andesitic Arc Volcanism: Mount Kerinci, Sunda Arc, Indonesia

NASA Astrophysics Data System (ADS)

Tully, M.; Saunders, K.; Troll, V. R.; Jolis, E.; Muir, D. D.; Deegan, F. M.; Budd, D. A.; Astbury, R.; Bromiley, G. D.

2014-12-01

Present knowledge of the chain of dominantly andesitic volcanoes, which span the Sumatran portion of the Sunda Arc is extremely limited. Previous studies have focused on Toba and Krakatau, although over 13 further volcanic edifices are known. Several recent explosive eruptions in Sumatra such as that of Mt. Sinabung, 2014, have highlighted the potential hazard that these volcanoes pose to the local and regional communities. Mount Kerinci, is one of the most active of the volcanoes in this region, yet little is known about the petrogenesis of the magma by which it is fed. Kerinci is located approximately mid-way between Toba in the North and Krakatau in the south. Along arc variations are observed in the major, minor and trace elements of whole rock analyses. However, bulk rock approaches produce an average chemical composition for a sample, potentially masking important chemical signatures. In-situ micro-analytical analysis of individual components of samples such as melt inclusions, crystals and groundmass provides chemical signatures of individual components allowing the evolution of volcanic centres to be deciphered in considerably more detail. Examination of whole rock chemistry indicates its location may be key to unravelling the petrogenesis of the arc as significant chemical changes occur between Kerinci and Kaba, 250 km to the south. Kerinci samples are dominantly porphyritic with large crystals of plagioclase, pyroxene and Fe-Ti oxides, rare olivine crystals are observed. Plagioclase and pyroxene crystals are chemically zoned and host melt inclusions. Multiple plagioclase populations are observed. A combination of in-situ micro-analysis techniques will be used to characterise the chemical composition of melt inclusions and crystals. These data can be used along with extant geothermobarometric models to help determine the magma source, storage conditions and composition of the evolving melt. Integration of the findings from this study with existing data for the volcanic chain will enable along-arc variations in magmatic processes in Sumatra to be assessed more thoroughly, providing fundamental insights into the evolution of not only Kerinci, but magma genesis in Sumatra in general. Keywords: Sunda Arc, andesite, arc volcanism, petrogenesis.

Revealing the Structural Complexity of Component Interactions of Topic-Specific PCK when Planning to Teach

NASA Astrophysics Data System (ADS)

Mavhunga, Elizabeth

2018-04-01

Teaching pedagogical content knowledge (PCK) at a topic-specific level requires clarity on the content-specific nature of the components employed, as well as the specific features that bring about the desirable depth in teacher explanations. Such understanding is often hazy; yet, it influences the nature of teacher tasks and learning opportunities afforded to pre-service teachers in a teaching program. The purpose of this study was twofold: firstly, to illuminate the emerging complexity when content-specific components of PCK interact when planning to teach a chemistry topic; and secondly, to identify the kinds of teacher tasks that promote the emergence of such complexity. Data collected were content representations (CoRes) in chemical equilibrium accompanied by expanded lesson outlines from 15 pre-service teachers in their final year of study towards a first degree in teaching (B Ed). The analysis involved extraction of episodes that exhibited component interaction by using a qualitative in-depth analysis method. The results revealed the structure in which the components of PCK in a topic interact among each other to be linear, interwoven, or a combination of the two. The interwoven interactions contained multiple components that connected explanations on different aspects of a concept, all working in a complementary manner. The most sophisticated component interactions emerged from teacher tasks on descriptions of a lesson sequence and a summary of a lesson. Recommendations in this study highlight core practices for making pedagogical transformation of topic content knowledge more accessible.

Partitioning of Dissolved Metals (Fe, Mn, Cu, Cd, Zn, Ni, and Pb) into Soluble and Colloidal Fractions in Continental Shelf and Offshore Waters, Northern California

NASA Astrophysics Data System (ADS)

Fitzsimmons, J. N.; Parker, C.; Sherrell, R. M.

2016-02-01

The physicochemical speciation of trace metals in seawater influences their cycling as essential micronutrients for microorganisms or as tracers of anthropogenic influences on the marine environment. While chemical speciation affects lability, the size of metal complexes influences their ability to be accessed biologically and also influences their fate in the aggregation pathway to marine particles. In this study, we show that multiple trace metals in shelf and open ocean waters off northern California (IRN-BRU cruise, July 2014) have colloidal-sized components. Colloidal fractions were operationally defined using two ultrafiltration methods: a 0.02 µm Anopore membrane and a 10 kDa ( 0.003 µm) cross flow filtration (CFF) system. Together these two methods distinguished small (0.003 - 0.02 µm) and large (0.02 µm - 0.2 µm) colloids. As has been found previously for seawater in other ocean regimes, dissolved Fe had a broad size distribution with 50% soluble (<10 kDa) complexes and both small and large colloidal species. Dissolved Mn had no measurable colloidal component, consistent with its predicted chemical speciation as free Mn(II). Dissolved Cu, which like Fe is thought to be nearly fully organically bound in seawater, was only 25% colloidal, and these colloids were all small. Surprisingly Cd, Ni, and Pb also showed colloidal components (8-20%, 25-40%, and 10-50%) despite their hypothesized low organic speciation. Zn and Pb were nearly completely sorbed onto the Anopore membrane, making CFF the only viable ultrafiltration method for those elements. Zn suffered incomplete recovery ( 50-75%) through the CFF system but showed 30-85% colloidal contribution; thus, verifying a Zn colloidal phase with these methods is challenging. Conclusions will reveal links between the physical and chemical speciation for these metals and what role these metal colloids might have on trace metal exchange between the ocean margin and offshore waters.

A Modular Control Platform for a Diode Pumped Alkali Laser

NASA Astrophysics Data System (ADS)

Shapiro, J.; Teare, S.

Many of the difficulties of creating compact, high power laser systems can be overcome if the heat dissipating properties of chemical lasers can be combined with the efficiency of diode lasers. Recently, the novel idea of using solid state diode lasers to pump gaseous gain media, such as is done in diode pumped alkali lasers (DPALs), has been proposed and early experiments have shown promising results. However, a number of technical issues need to be overcome to realize high output power from these lasers. In order to achieve higher power, the efficiency of coupling between pump laser energy and the chemical cell must be increased, and eventually multiple high power diode pumps must be combined and synchronized so that their energy can pump the chemical cell. Additionally, an inter-cavity adaptive optics system may be a requirement to be able to propagate these lasers with high efficiency. DPAL systems are complex and require a significant amount of data fusion and active feedback to control and optimize their performance. There are a wide range of components including pump lasers, gain cells and monitoring points needed to study and refine the overall laser system. In support of this dynamic development environment, we have developed a hardware framework using commercial off the shelf (COTS) components which supports the rapid assembly of functional system blocks into a cohesive integrated system. Critical to this system are a simple communication protocol, industry standard communication pipes (USB, Bluetooth, etc), and flexible high level scripting. Simplifying the integration process has the benefit of allowing flexible "on the fly" modifications to adapt the system as needed and enhance available functionality. The modular nature of the architecture allows scalability and adaptability as more pieces are added to the system. Key components of this system are demonstrated for selected portions of a DPAL system using a USB backbone.

Classifying four-category visual objects using multiple ERP components in single-trial ERP.

PubMed

Qin, Yu; Zhan, Yu; Wang, Changming; Zhang, Jiacai; Yao, Li; Guo, Xiaojuan; Wu, Xia; Hu, Bin

2016-08-01

Object categorization using single-trial electroencephalography (EEG) data measured while participants view images has been studied intensively. In previous studies, multiple event-related potential (ERP) components (e.g., P1, N1, P2, and P3) were used to improve the performance of object categorization of visual stimuli. In this study, we introduce a novel method that uses multiple-kernel support vector machine to fuse multiple ERP component features. We investigate whether fusing the potential complementary information of different ERP components (e.g., P1, N1, P2a, and P2b) can improve the performance of four-category visual object classification in single-trial EEGs. We also compare the classification accuracy of different ERP component fusion methods. Our experimental results indicate that the classification accuracy increases through multiple ERP fusion. Additional comparative analyses indicate that the multiple-kernel fusion method can achieve a mean classification accuracy higher than 72 %, which is substantially better than that achieved with any single ERP component feature (55.07 % for the best single ERP component, N1). We compare the classification results with those of other fusion methods and determine that the accuracy of the multiple-kernel fusion method is 5.47, 4.06, and 16.90 % higher than those of feature concatenation, feature extraction, and decision fusion, respectively. Our study shows that our multiple-kernel fusion method outperforms other fusion methods and thus provides a means to improve the classification performance of single-trial ERPs in brain-computer interface research.

30 CFR 7.508 - Harmful gas removal components.

Code of Federal Regulations, 2012 CFR

2012-07-01

... chemical used for removal of harmful gas shall be— (1) Contained such that when stored or used it cannot... for disposal of used chemical. (c) Each harmful gas removal component shall be tested to determine its... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Harmful gas removal components. 7.508 Section 7...

30 CFR 7.508 - Harmful gas removal components.

Code of Federal Regulations, 2013 CFR

2013-07-01

... chemical used for removal of harmful gas shall be— (1) Contained such that when stored or used it cannot... for disposal of used chemical. (c) Each harmful gas removal component shall be tested to determine its... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Harmful gas removal components. 7.508 Section 7...

30 CFR 7.508 - Harmful gas removal components.

Code of Federal Regulations, 2014 CFR

2014-07-01

... chemical used for removal of harmful gas shall be— (1) Contained such that when stored or used it cannot... for disposal of used chemical. (c) Each harmful gas removal component shall be tested to determine its... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Harmful gas removal components. 7.508 Section 7...

Update on the Chemical Composition Of Crystalline, Smectite, and Amorphous Components for Rocknest Soil and John Klein and Cumberland Mudstone Drill Fines at Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Morris, R. V.; Ming, D. W.; Gellert, R.; Vaniman, D. T.; Bish, D. L.; Blake, D. F.; Chipera, S. J.; Morrison, S. M.; Downs, R. T.; Rampe, E. B.;

Gene expression profiles in rainbow trout, Onchorynchus mykiss, exposed to a simple chemical mixture.

PubMed

Hook, Sharon E; Skillman, Ann D; Gopalan, Banu; Small, Jack A; Schultz, Irvin R

2008-03-01

Among proposed uses for microarrays in environmental toxiciology is the identification of key contributors to toxicity within a mixture. However, it remains uncertain whether the transcriptomic profiles resulting from exposure to a mixture have patterns of altered gene expression that contain identifiable contributions from each toxicant component. We exposed isogenic rainbow trout Onchorynchus mykiss, to sublethal levels of ethynylestradiol, 2,2,4,4-tetrabromodiphenyl ether, and chromium VI or to a mixture of all three toxicants Fluorescently labeled complementary DNA (cDNA) were generated and hybridized against a commercially available Salmonid array spotted with 16,000 cDNAs. Data were analyzed using analysis of variance (p<0.05) with a Benjamani-Hochberg multiple test correction (Genespring [Agilent] software package) to identify up and downregulated genes. Gene clustering patterns that can be used as "expression signatures" were determined using hierarchical cluster analysis. The gene ontology terms associated with significantly altered genes were also used to identify functional groups that were associated with toxicant exposure. Cross-ontological analytics approach was used to assign functional annotations to genes with "unknown" function. Our analysis indicates that transcriptomic profiles resulting from the mixture exposure resemble those of the individual contaminant exposures, but are not a simple additive list. However, patterns of altered genes representative of each component of the mixture are clearly discernible, and the functional classes of genes altered represent the individual components of the mixture. These findings indicate that the use of microarrays to identify transcriptomic profiles may aid in the identification of key stressors within a chemical mixture, ultimately improving environmental assessment.

Extracting the Behaviorally Relevant Stimulus: Unique Neural Representation of Farnesol, a Component of the Recruitment Pheromone of Bombus terrestris

PubMed Central

Strube-Bloss, Martin F.; Brown, Austin; Spaethe, Johannes; Schmitt, Thomas; Rössler, Wolfgang

2015-01-01

To trigger innate behavior, sensory neural networks are pre-tuned to extract biologically relevant stimuli. Many male-female or insect-plant interactions depend on this phenomenon. Especially communication among individuals within social groups depends on innate behaviors. One example is the efficient recruitment of nest mates by successful bumblebee foragers. Returning foragers release a recruitment pheromone in the nest while they perform a ‘dance’ behavior to activate unemployed nest mates. A major component of this pheromone is the sesquiterpenoid farnesol. How farnesol is processed and perceived by the olfactory system, has not yet been identified. It is much likely that processing farnesol involves an innate mechanism for the extraction of relevant information to trigger a fast and reliable behavioral response. To test this hypothesis, we used population response analyses of 100 antennal lobe (AL) neurons recorded in alive bumblebee workers under repeated stimulation with four behaviorally different, but chemically related odorants (geraniol, citronellol, citronellal and farnesol). The analysis identified a unique neural representation of the recruitment pheromone component compared to the other odorants that are predominantly emitted by flowers. The farnesol induced population activity in the AL allowed a reliable separation of farnesol from all other chemically related odor stimuli we tested. We conclude that the farnesol induced population activity may reflect a predetermined representation within the AL-neural network allowing efficient and fast extraction of a behaviorally relevant stimulus. Furthermore, the results show that population response analyses of multiple single AL-units may provide a powerful tool to identify distinct representations of behaviorally relevant odors. PMID:26340263

Identification of flavour additives in tobacco products to develop a flavour library

PubMed Central

Krüsemann, Erna JZ; Visser, Wouter F; Cremers, Johannes WJM; Pennings, Jeroen LA; Talhout, Reinskje

2018-01-01

Objectives This study combines chemical analysis and flavour descriptions of flavour additives used in tobacco products, and provides a starting point to build an extensive library of flavour components, useful for product surveillance. Methods Headspace gas chromatography-mass spectrometry (GC-MS) was used to compare 22 commercially available tobacco products (cigarettes and roll-your-own) expected to have a characterising flavour and 6 commercially available products not expected to have a characterising flavour with 5 reference products (natural tobacco leaves and research cigarettes containing no flavour additives). The flavour components naturally present in the reference products were excluded from components present in commercially available products containing flavour additives. A description of the remaining flavour additives was used for categorisation. Results GC-MS measurements of the 33 tobacco products resulted in an overview of 186 chemical compounds. Of these, 144 were solely present in commercially available products. These 144 flavour additives were described using 62 different flavour descriptors extracted from flavour databases, which were categorised into eight groups largely based on the definition of characterising flavours from the European Tobacco Product Directive: fruit, spice, herb, alcohol, menthol, sweet, floral and miscellaneous. Conclusions We developed a method to identify and describe flavour additives in tobacco products. Flavour additives consist of single flavour compounds or mixtures of multiple flavour compounds, and different combinations of flavour compounds can cause a certain flavour. A flavour library helps to detect flavour additives that are characteristic for a certain flavour, and thus can be useful for regulation of flavours in tobacco and related products. PMID:28190004

Task 90-17: Decontaminability study on the U. S. Army Resuscitation Device, Individual, Chemical (RDIC). Final report, 1 Oct 90-24 Jan 91

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dill, G.S.; Leonard, R.D.

1991-04-01

A study was performed to determine the effect of three commonly used field decontaminants, DS2, super tropical bleach (STB), and the M270 Decontaminating Kit, Individual (DKIE), on the Resuscitation Device, Chemical, Individual (RDIC). The RDIC system was analyzed to determine which components were accessible to chemical agents and could be degraded by them. The chemical agent susceptibility of the silicone rubber components is the weakest point in the RDIC system. The lack of accessibility of key components to the wetted DKIE wipes and the deterioration of key components by DS2 eliminates these two methods as possible decontaminant methods. STB hadmore » no noticeable effects on the RDIC and is recommended as the best field decontamination method.« less

Chemical ageing and transformation of diffusivity in semi-solid multi-component organic aerosol particles

NASA Astrophysics Data System (ADS)

Pfrang, C.; Shiraiwa, M.; Pöschl, U.

2011-04-01

Recent experimental evidence underlines the importance of reduced diffusivity in amorphous semi-solid or glassy atmospheric aerosols. This paper investigates the impact of diffusivity on the ageing of multi-component reactive organic particles representative of atmospheric cooking aerosols. We apply and extend the recently developed KM-SUB model in a study of a 12-component mixture containing oleic and palmitoleic acids. We demonstrate that changes in the diffusivity may explain the evolution of chemical loss rates in ageing semi-solid particles, and we resolve surface and bulk processes under transient reaction conditions considering diffusivities altered by oligomerisation. This new model treatment allows prediction of the ageing of mixed organic multi-component aerosols over atmospherically relevant time scales and conditions. We illustrate the impact of changing diffusivity on the chemical half-life of reactive components in semi-solid particles, and we demonstrate how solidification and crust formation at the particle surface can affect the chemical transformation of organic aerosols.

Chemical ageing and transformation of diffusivity in semi-solid multi-component organic aerosol particles

NASA Astrophysics Data System (ADS)

Pfrang, C.; Shiraiwa, M.; Pöschl, U.

2011-07-01

Recent experimental evidence underlines the importance of reduced diffusivity in amorphous semi-solid or glassy atmospheric aerosols. This paper investigates the impact of diffusivity on the ageing of multi-component reactive organic particles approximating atmospheric cooking aerosols. We apply and extend the recently developed KM-SUB model in a study of a 12-component mixture containing oleic and palmitoleic acids. We demonstrate that changes in the diffusivity may explain the evolution of chemical loss rates in ageing semi-solid particles, and we resolve surface and bulk processes under transient reaction conditions considering diffusivities altered by oligomerisation. This new model treatment allows prediction of the ageing of mixed organic multi-component aerosols over atmospherically relevant timescales and conditions. We illustrate the impact of changing diffusivity on the chemical half-life of reactive components in semi-solid particles, and we demonstrate how solidification and crust formation at the particle surface can affect the chemical transformation of organic aerosols.

Laboratory Inquiry for Determining the Chemical Composition of a Component in a Daily Use Detergent: Sodium Sesquicarbonate

ERIC Educational Resources Information Center

Koga, Nobuyoshi; Kimura, Tomoyasu; Shigedomi, Kana

2011-01-01

An inquiry-based laboratory activity to determine the chemical composition of a component in alkaline detergents, sodium sesquicarbonate (SSC), is proposed. On the basis of introductory demonstrations by the instructor on the chemical properties and reactions of SSC, students propose the hypothetical composition of SSC and possible quantitative…

Topological Characterization of Carbon Graphite and Crystal Cubic Carbon Structures.

PubMed

Siddiqui, Wei Gao Muhammad Kamran; Naeem, Muhammad; Rehman, Najma Abdul

2017-09-07

Graph theory is used for modeling, designing, analysis and understanding chemical structures or chemical networks and their properties. The molecular graph is a graph consisting of atoms called vertices and the chemical bond between atoms called edges. In this article, we study the chemical graphs of carbon graphite and crystal structure of cubic carbon. Moreover, we compute and give closed formulas of degree based additive topological indices, namely hyper-Zagreb index, first multiple and second multiple Zagreb indices, and first and second Zagreb polynomials.

Rapid Characterization of Constituents in Tribulus terrestris from Different Habitats by UHPLC/Q-TOF MS.

PubMed

Zheng, Wei; Wang, Fangxu; Zhao, Yang; Sun, Xinguang; Kang, Liping; Fan, Ziquan; Qiao, Lirui; Yan, Renyi; Liu, Shuchen; Ma, Baiping

2017-11-01

A strategy for rapid identification of the chemical constituents from crude extracts of Tribulus terrestris was proposed using an informatics platform for the UHPLC/Q-TOF MS E data analyses. This strategy mainly utilizes neutral losses, characteristic fragments, and in-house library to rapidly identify the structure of the compounds. With this strategy, rapid characterization of the chemical components of T. terrestris from Beijing, China was successfully achieved. A total of 82 steroidal saponins and nine flavonoids were identified or tentatively identified from T. terrestris. Among them, 15 new components were deduced based on retention times and characteristic MS fragmentation patterns. Furthermore, the chemical components of T. terrestris, including the other two samples from Xinjiang Uygur Autonomous region, China, and Rome, Italy, were also identified with this strategy. Altogether, 141 chemical components were identified from these three samples, of which 39 components were identified or tentatively identified as new compounds, including 35 groups of isomers. It demonstrated that this strategy provided an efficient protocol for the rapid identification of chemical constituents in complex samples such as traditional Chinese medicines (TCMs) by UHPLC/Q-TOF MS E with informatics platform. Graphical Abstract ᅟ.

Correlation between dynamic wetting behavior and chemical components of thermally modified wood

NASA Astrophysics Data System (ADS)

Wang, Wang; Zhu, Yuan; Cao, Jinzhen; Sun, Wenjing

2015-01-01

In order to investigate the dynamic wetting behavior of thermally modified wood, Cathay poplar (Populus cathayana Rehd.) and Scots pine (Pinus sylvestris L.) samples were thermally modified in an oven at 160, 180, 200, 220 or 240 °C for 4 h in this study. The dynamic contact angles and droplet volumes of water droplets on modified and unmodified wood surfaces were measured by sessile drop method, and their changing rates (expression index: K value and wetting slope) calculated by wetting models were illustrated for mapping the dynamic wetting process. The surface chemical components were also measured by X-ray photoelectron spectroscopy analysis (XPS), thus the relationship between dynamic wetting behavior and chemical components of thermally modified wood were determined. The results indicated that thermal modification was capable of decreasing the dynamic wettability of wood, expressed in lowing spread and penetration speed of water droplets on wood surfaces. This change was more obvious with the increased heating temperature. The K values varied linearly with the chemical components parameter (mass loss, O/C ratio, and C1/C2 ratio), indicating a strong correlation between dynamic wetting behavior and chemical components of thermally modified wood.

Rapid Characterization of Constituents in Tribulus terrestris from Different Habitats by UHPLC/Q-TOF MS

NASA Astrophysics Data System (ADS)

Zheng, Wei; Wang, Fangxu; Zhao, Yang; Sun, Xinguang; Kang, Liping; Fan, Ziquan; Qiao, Lirui; Yan, Renyi; Liu, Shuchen; Ma, Baiping

2017-08-01

A strategy for rapid identification of the chemical constituents from crude extracts of Tribulus terrestris was proposed using an informatics platform for the UHPLC/Q-TOF MSE data analyses. This strategy mainly utilizes neutral losses, characteristic fragments, and in-house library to rapidly identify the structure of the compounds. With this strategy, rapid characterization of the chemical components of T. terrestris from Beijing, China was successfully achieved. A total of 82 steroidal saponins and nine flavonoids were identified or tentatively identified from T. terrestris. Among them, 15 new components were deduced based on retention times and characteristic MS fragmentation patterns. Furthermore, the chemical components of T. terrestris, including the other two samples from Xinjiang Uygur Autonomous region, China, and Rome, Italy, were also identified with this strategy. Altogether, 141 chemical components were identified from these three samples, of which 39 components were identified or tentatively identified as new compounds, including 35 groups of isomers. It demonstrated that this strategy provided an efficient protocol for the rapid identification of chemical constituents in complex samples such as traditional Chinese medicines (TCMs) by UHPLC/Q-TOF MSE with informatics platform. [Figure not available: see fulltext.

Ecosystem services and the protection, restoration, and management of ecosystems exposed to chemical stressors.

PubMed

Maltby, Lorraine

2013-04-01

Ecosystem services-the benefits people obtain from ecosystem structures and processes-are essential for human survival and well-being. Chemicals are also an essential component of modern life; however, they may cause adverse ecological effects and reduce ecosystem service provision. Environmental policy makers are increasingly adopting the ecosystem services concept, but applying this approach to the protection, restoration, and management of ecosystems requires the development of new understanding, tools, and frameworks. There is an urgent need to understand and predict the effect of single and multiple stressors on ecosystem service delivery across different spatial scales (local to global), to develop indicators that can be used to quantify and map services and identify synergies and trade-offs between them, to establish protection goals and restoration targets defined in terms of the types and levels of service delivery required, and to develop approaches for the assessment and management of chemical risk to ecosystem services that consider the whole life cycle of products and processes. These are major research challenges for the environmental science community in general and for ecotoxicologists and risk assessors in particular. Copyright © 2013 SETAC.

Fluorescence Intrinsic Characterization of Excitation-Emission Matrix Using Multi-Dimensional Ensemble Empirical Mode Decomposition

PubMed Central

Chang, Chi-Ying; Chang, Chia-Chi; Hsiao, Tzu-Chien

2013-01-01

Excitation-emission matrix (EEM) fluorescence spectroscopy is a noninvasive method for tissue diagnosis and has become important in clinical use. However, the intrinsic characterization of EEM fluorescence remains unclear. Photobleaching and the complexity of the chemical compounds make it difficult to distinguish individual compounds due to overlapping features. Conventional studies use principal component analysis (PCA) for EEM fluorescence analysis, and the relationship between the EEM features extracted by PCA and diseases has been examined. The spectral features of different tissue constituents are not fully separable or clearly defined. Recently, a non-stationary method called multi-dimensional ensemble empirical mode decomposition (MEEMD) was introduced; this method can extract the intrinsic oscillations on multiple spatial scales without loss of information. The aim of this study was to propose a fluorescence spectroscopy system for EEM measurements and to describe a method for extracting the intrinsic characteristics of EEM by MEEMD. The results indicate that, although PCA provides the principal factor for the spectral features associated with chemical compounds, MEEMD can provide additional intrinsic features with more reliable mapping of the chemical compounds. MEEMD has the potential to extract intrinsic fluorescence features and improve the detection of biochemical changes. PMID:24240806

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vijayakumar, M.; Nie, Zimin; Walter, Eric D.

Redox flow battery (RFB) is a promising candidate for energy storage component in designing resilient grid scale power supply due to the advantage of the separation of power and energy. However, poorly understood chemical and thermal stability issues of electrolytes currently limit the performance of RFB. Designing of high performance stable electrolytes requires comprehensive knowledge about the molecular level solvation structure and dynamics of their redox active species. The molecular level understanding of detrimental V2O5 precipitation process led to successful designing of mixed acid based electrolytes for vanadium redox flow batteries (VRFB). The higher stability of mixed acid based electrolytesmore » is attributed to the choice of hydrochloric acid as optimal co-solvent, which provides chloride anions for ligand exchange process in vanadium solvation structure. The role of chloride counter anion on solvation structure and dynamics of vanadium species were studied using combined magnetic resonance spectroscopy and DFT based theoretical methods. Finally, the solvation phenomenon of multiple vanadium species and their impact on VRFB electrolyte chemical stability were discussed.« less

Accelerated oral nanomedicine discovery from miniaturized screening to clinical production exemplified by paediatric HIV nanotherapies

PubMed Central

Giardiello, Marco; Liptrott, Neill J.; McDonald, Tom O.; Moss, Darren; Siccardi, Marco; Martin, Phil; Smith, Darren; Gurjar, Rohan; Rannard, Steve P.; Owen, Andrew

2016-01-01

Considerable scope exists to vary the physical and chemical properties of nanoparticles, with subsequent impact on biological interactions; however, no accelerated process to access large nanoparticle material space is currently available, hampering the development of new nanomedicines. In particular, no clinically available nanotherapies exist for HIV populations and conventional paediatric HIV medicines are poorly available; one current paediatric formulation utilizes high ethanol concentrations to solubilize lopinavir, a poorly soluble antiretroviral. Here we apply accelerated nanomedicine discovery to generate a potential aqueous paediatric HIV nanotherapy, with clinical translation and regulatory approval for human evaluation. Our rapid small-scale screening approach yields large libraries of solid drug nanoparticles (160 individual components) targeting oral dose. Screening uses 1 mg of drug compound per library member and iterative pharmacological and chemical evaluation establishes potential candidates for progression through to clinical manufacture. The wide applicability of our strategy has implications for multiple therapy development programmes. PMID:27767027

Discovery and characterization of heme enzymes from unsequenced bacteria: application to microbial lignin degradation.

PubMed

Brown, Margaret E; Walker, Mark C; Nakashige, Toshiki G; Iavarone, Anthony T; Chang, Michelle C Y

2011-11-16

Bacteria and other living organisms offer a potentially unlimited resource for the discovery of new chemical catalysts, but many interesting reaction phenotypes observed at the whole organism level remain difficult to elucidate down to the molecular level. A key challenge in the discovery process is the identification of discrete molecular players involved in complex biological transformations because multiple cryptic genetic components often work in concert to elicit an overall chemical phenotype. We now report a rapid pipeline for the discovery of new enzymes of interest from unsequenced bacterial hosts based on laboratory-scale methods for the de novo assembly of bacterial genome sequences using short reads. We have applied this approach to the biomass-degrading soil bacterium Amycolatopsis sp. 75iv2 ATCC 39116 (formerly Streptomyces setonii and S. griseus 75vi2) to discover and biochemically characterize two new heme proteins comprising the most abundant members of the extracellular oxidative system under lignin-reactive growth conditions.

Use of volatile organic components in scat to identify canid species

USGS Publications Warehouse

Burnham, E.; Bender, L.C.; Eiceman, G.A.; Pierce, K.M.; Prasad, S.

2008-01-01

Identification of wildlife species from indirect evidence can be an important part of wildlife management, and conventional +methods can be expensive or have high error rates. We used chemical characterization of the volatile organic constituents (VOCs) in scat as a method to identify 5 species of North American canids from multiple individuals. We sampled vapors of scats in the headspace over a sample using solid-phase microextraction and determined VOC content using gas chromatography with a flame ionization detector. We used linear discriminant analysis to develop models for differentiating species with bootstrapping to estimate accuracy. Our method correcdy classified 82.4% (bootstrapped 95% CI = 68.8-93.8%) of scat samples. Red fox (Vulpes vulpes) scat was most frequendy misclassified (25.0% of scats misclassified); red fox was also the most common destination for misclassified samples. Our findings are the first reported identification of animal species using VOCs in vapor emissions from scat and suggest that identification of wildlife species may be plausible through chemical characterization of vapor emissions of scat.

Sex pheromone biosynthetic pathways are conserved between moths and the butterfly Bicyclus anynana

PubMed Central

Liénard, Marjorie A; Wang, Hong-Lei; Lassance, Jean-Marc; Löfstedt, Christer

2014-01-01

Although phylogenetically nested within the moths, butterflies have diverged extensively in a number of life history traits. Whereas moths rely greatly on chemical signals, visual advertisement is the hallmark of mate finding in butterflies. In the context of courtship, however, male chemical signals are widespread in both groups although they likely have multiple evolutionary origins. Here, we report that in males of the butterfly Bicyclus anynana, courtship scents are produced de novo via biosynthetic pathways shared with females of many moth species. We show that two of the pheromone components that play a major role in mate choice, namely the (Z)-9-tetradecenol and hexadecanal, are produced through the activity of a fatty acyl Δ11-desaturase and two specialized alcohol-forming fatty acyl reductases. Our study provides the first evidence of conservation and sharing of ancestral genetic modules for the production of FA-derived pheromones over a long evolutionary timeframe thereby reconciling mate communication in moths and butterflies. PMID:24862548

21 CFR 201.120 - Prescription chemicals and other prescription components.

Code of Federal Regulations, 2010 CFR

2010-04-01

... prescription chemical or other component for use by registered pharmacists in compounding prescriptions or for... retail pharmacists sold in or from the interstate package for use by consumers, “adequate directions for...

21 CFR 201.120 - Prescription chemicals and other prescription components.

Code of Federal Regulations, 2013 CFR

2013-04-01

... prescription chemical or other component for use by registered pharmacists in compounding prescriptions or for... retail pharmacists sold in or from the interstate package for use by consumers, “adequate directions for...

21 CFR 201.120 - Prescription chemicals and other prescription components.

Code of Federal Regulations, 2012 CFR

2012-04-01

... prescription chemical or other component for use by registered pharmacists in compounding prescriptions or for... retail pharmacists sold in or from the interstate package for use by consumers, “adequate directions for...

21 CFR 201.120 - Prescription chemicals and other prescription components.

Code of Federal Regulations, 2014 CFR

2014-04-01

... prescription chemical or other component for use by registered pharmacists in compounding prescriptions or for... retail pharmacists sold in or from the interstate package for use by consumers, “adequate directions for...

21 CFR 201.120 - Prescription chemicals and other prescription components.

Code of Federal Regulations, 2011 CFR

2011-04-01

... prescription chemical or other component for use by registered pharmacists in compounding prescriptions or for... retail pharmacists sold in or from the interstate package for use by consumers, “adequate directions for...

Mixture effects in samples of multiple contaminants - An inter-laboratory study with manifold bioassays.

PubMed

Altenburger, Rolf; Scholze, Martin; Busch, Wibke; Escher, Beate I; Jakobs, Gianina; Krauss, Martin; Krüger, Janet; Neale, Peta A; Ait-Aissa, Selim; Almeida, Ana Catarina; Seiler, Thomas-Benjamin; Brion, François; Hilscherová, Klára; Hollert, Henner; Novák, Jiří; Schlichting, Rita; Serra, Hélène; Shao, Ying; Tindall, Andrew; Tolefsen, Knut-Erik; Umbuzeiro, Gisela; Williams, Tim D; Kortenkamp, Andreas

2018-05-01

Chemicals in the environment occur in mixtures rather than as individual entities. Environmental quality monitoring thus faces the challenge to comprehensively assess a multitude of contaminants and potential adverse effects. Effect-based methods have been suggested as complements to chemical analytical characterisation of complex pollution patterns. The regularly observed discrepancy between chemical and biological assessments of adverse effects due to contaminants in the field may be either due to unidentified contaminants or result from interactions of compounds in mixtures. Here, we present an interlaboratory study where individual compounds and their mixtures were investigated by extensive concentration-effect analysis using 19 different bioassays. The assay panel consisted of 5 whole organism assays measuring apical effects and 14 cell- and organism-based bioassays with more specific effect observations. Twelve organic water pollutants of diverse structure and unique known modes of action were studied individually and as mixtures mirroring exposure scenarios in freshwaters. We compared the observed mixture effects against component-based mixture effect predictions derived from additivity expectations (assumption of non-interaction). Most of the assays detected the mixture response of the active components as predicted even against a background of other inactive contaminants. When none of the mixture components showed any activity by themselves then the mixture also was without effects. The mixture effects observed using apical endpoints fell in the middle of a prediction window defined by the additivity predictions for concentration addition and independent action, reflecting well the diversity of the anticipated modes of action. In one case, an unexpectedly reduced solubility of one of the mixture components led to mixture responses that fell short of the predictions of both additivity mixture models. The majority of the specific cell- and organism-based endpoints produced mixture responses in agreement with the additivity expectation of concentration addition. Exceptionally, expected (additive) mixture response did not occur due to masking effects such as general toxicity from other compounds. Generally, deviations from an additivity expectation could be explained due to experimental factors, specific limitations of the effect endpoint or masking side effects such as cytotoxicity in in vitro assays. The majority of bioassays were able to quantitatively detect the predicted non-interactive, additive combined effect of the specifically bioactive compounds against a background of complex mixture of other chemicals in the sample. This supports the use of a combination of chemical and bioanalytical monitoring tools for the identification of chemicals that drive a specific mixture effect. Furthermore, we demonstrated that a panel of bioassays can provide a diverse profile of effect responses to a complex contaminated sample. This could be extended towards representing mixture adverse outcome pathways. Our findings support the ongoing development of bioanalytical tools for (i) compiling comprehensive effect-based batteries for water quality assessment, (ii) designing tailored surveillance methods to safeguard specific water uses, and (iii) devising strategies for effect-based diagnosis of complex contamination. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

[Multiple chemical sensitivity, a well-defined illness?].

PubMed

Kolstad, Henrik A; Silberschmidt, Martin; Nielsen, Jesper Bo; Osterberg, Kai; Andersen, Johan Hviid; Bonde, Jens Peter E; Fink, Per

2006-03-13

Some people react to smells or chemicals at levels far below toxicological thresholds with nonspecific symptoms, fear and social isolation. They may be diagnosed with multiple chemical sensitivity. There is no empirical evidence indicating that this condition is explained by toxicological mechanisms, even though a number of theories have been proposed. The authors of this review conclude that this is a functional condition. These patients need information and treatment in accordance with this fact. Instead of being advised how to avoid exposure to chemicals, they should be properly trained in appropriate confrontation with the chemicals encountered in everyday life.

Quantification and semiquantification of multiple representative components for the holistic quality control of Allii Macrostemonis Bulbus by ultra high performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry.

PubMed

Qin, Zifei; Lin, Pei; Dai, Yi; Yao, Zhihong; Wang, Li; Yao, Xinsheng; Liu, Liyin; Chen, Haifeng

2016-05-01

Allii Macrostemonis Bulbus (named Xiebai in China) is a folk medicine with medicinal values for the treatment of thoracic obstruction and cardialgia, and a food additive as well. However, there is even no quantitative standard for Allii Macrostemonis Bulbus recorded in the current edition of the Chinese Pharmacopeia. Hence, simultaneous assay of multiple components is urgent. In this study, chemometric methods were firstly applied to discover the components with significant fluctuation among multiple Allii Macrostemonis Bulbus samples based on optimized fingerprints. Meanwhile, the major components and main absorbed components in rats were all selected as its representative components. Subsequently, a sensitive method was established for the simultaneous determination of 54 components (15 components for quantification and 39 components for semiquantification) by ultra high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. Moreover, the validated method was successfully applied to evaluate the quality of multiple samples on the market. It became known that multiple Allii Macrostemonis Bulbus samples varied significantly and showed poor consistency. This work illustrated that the proposed approach could improve the quality of Allii Macrostemonis Bulbus, and it also provided a feasible method for quality evaluation of other traditional Chinese medicines. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microfluidic chemical reaction circuits

DOEpatents

Lee, Chung-cheng [Irvine, CA; Sui, Guodong [Los Angeles, CA; Elizarov, Arkadij [Valley Village, CA; Kolb, Hartmuth C [Playa del Rey, CA; Huang, Jiang [San Jose, CA; Heath, James R [South Pasadena, CA; Phelps, Michael E [Los Angeles, CA; Quake, Stephen R [Stanford, CA; Tseng, Hsian-rong [Los Angeles, CA; Wyatt, Paul [Tipperary, IE; Daridon, Antoine [Mont-Sur-Rolle, CH

2012-06-26

New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

The Amorphous Component in Martian Basaltic Soil in Global Perspective from MSL and MER Missions

NASA Technical Reports Server (NTRS)

Morris, R. V.; Ming, D. W.; Blake, D. F.; Vaniman, D. T.; Bish, D. L.; Chipera, S. J.; Downs, R. T.; Gellert, R.; Treiman, A. H.; Yen, A. S.;

Testing of candidate waste-package backfill and canister materials for basalt

NASA Astrophysics Data System (ADS)

Wood, M. I.; Anderson, W. J.; Aden, G. D.

1982-09-01

The Basalt Waste Isolation Project (BWIP) is developing a multiple-barrier waste package to contain high-level nuclear waste as part of an overall system (e.g., waste package, repository sealing system, and host rock) designed to isolate the waste in a repository located in basalt beneath the Hanford Site, Richland, Washington. The three basic components of the waste package are the waste form, the canister, and the backfill. An extensive testing program is under way to determine the chemical, physical, and mechanical properties of potential canister and backfill materials. The data derived from this testing program will be used to recommend those materials that most adequately perform the functions assigned to the canister and backfill.

Anomalous high capacitance in a coaxial single nanowire capacitor.

PubMed

Liu, Zheng; Zhan, Yongjie; Shi, Gang; Moldovan, Simona; Gharbi, Mohamed; Song, Li; Ma, Lulu; Gao, Wei; Huang, Jiaqi; Vajtai, Robert; Banhart, Florian; Sharma, Pradeep; Lou, Jun; Ajayan, Pulickel M

2012-06-06

Building entire multiple-component devices on single nanowires is a promising strategy for miniaturizing electronic applications. Here we demonstrate a single nanowire capacitor with a coaxial asymmetric Cu-Cu(2)O-C structure, fabricated using a two-step chemical reaction and vapour deposition method. The capacitance measured from a single nanowire device corresponds to ~140 μF cm(-2), exceeding previous reported values for metal-insulator-metal micro-capacitors and is more than one order of magnitude higher than what is predicted by classical electrostatics. Quantum mechanical calculations indicate that this unusually high capacitance may be attributed to a negative quantum capacitance of the dielectric-metal interface, enhanced significantly at the nanoscale.

A New All Solid State Approach to Gaseous Pollutant Detection

NASA Technical Reports Server (NTRS)

Brown, V.; Tamstorf, K.

1971-01-01

Recent efforts in our laboratories have concentrated on the development of an all solid state gas sensor, by combining solid electrolyte (ion exchange membrane) technology with advanced thin film deposition processes. With the proper bias magnitude and polarity these miniature electro-chemical,cells show remarkable current responses for many common pollution gases. Current activity is now focused on complementing a multiple array (matrix) of these solid state sensors, with a digital electronic scanner device possessing "scan-compare-identify-alarm: capability. This innovative approach to multi-component pollutant gas analysis may indeed be the advanced prototype for the "third generation" class of pollution analysis instrumentation so urgently needed in the decade ahead.

Enthalpy Distributions of Arc Jet Flow Based on Measured Laser Induced Fluorescence, Heat Flux and Stagnation Pressure Distributions

NASA Technical Reports Server (NTRS)

Suess, Leonard E.; Milhoan, James D.; Oelke, Lance; Godfrey, Dennis; Larin, Maksim Y.; Scott, Carl D.; Grinstead, Jay H.; DelPapa, Steven

2011-01-01

The centerline total enthalpy of arc jet flow is determined using laser induced fluorescence of oxygen and nitrogen atoms. Each component of the energy, kinetic, thermal, and chemical can be determined from LIF measurements. Additionally, enthalpy distributions are inferred from heat flux and pressure probe distribution measurements using an engineering formula. Average enthalpies are determined by integration over the radius of the jet flow, assuming constant mass flux and a mass flux distribution estimated from computational fluid dynamics calculations at similar arc jet conditions. The trends show favorable agreement, but there is an uncertainty that relates to the multiple individual measurements and assumptions inherent in LIF measurements.

Sampling phasic dopamine signaling with fast-scan cyclic voltammetry in awake, behaving rats.

PubMed

Fortin, S M; Cone, J J; Ng-Evans, S; McCutcheon, J E; Roitman, M F

2015-01-05

Fast-scan cyclic voltammetry (FSCV) is an electrochemical technique that permits the in vivo measurement of extracellular fluctuations in multiple chemical species. The technique is frequently utilized to sample sub-second (phasic) concentration changes of the neurotransmitter dopamine in awake and behaving rats. Phasic dopamine signaling is implicated in reinforcement, goal-directed behavior, and locomotion, and FSCV has been used to investigate how rapid changes in striatal dopamine concentration contribute to these and other behaviors. This unit describes the instrumentation and construction, implantation, and use of components required to sample and analyze dopamine concentration changes in awake rats with FSCV. Copyright © 2015 John Wiley & Sons, Inc.

Batch compositions for cordierite ceramics

DOEpatents

Hickman, David L.

1994-07-26

Ceramic products consisting principally of cordierite and a method for making them are provided, the method employing batches comprising a mineral component and a chemical component, the mineral component comprising clay and talc and the chemical component consisting essentially of a combination of the powdered oxides, hydroxides, or hydrous oxides of magnesium, aluminum and silicon. Ceramics made by extrusion and firing of the batches can exhibit low porosity, high strength and low thermal expansion coefficients.

Comparative proteomic assessment of matrisome enrichment methodologies.

PubMed

Krasny, Lukas; Paul, Angela; Wai, Patty; Howard, Beatrice A; Natrajan, Rachael C; Huang, Paul H

2016-11-01

The matrisome is a complex and heterogeneous collection of extracellular matrix (ECM) and ECM-associated proteins that play important roles in tissue development and homeostasis. While several strategies for matrisome enrichment have been developed, it is currently unknown how the performance of these different methodologies compares in the proteomic identification of matrisome components across multiple tissue types. In the present study, we perform a comparative proteomic assessment of two widely used decellularisation protocols and two extraction methods to characterise the matrisome in four murine organs (heart, mammary gland, lung and liver). We undertook a systematic evaluation of the performance of the individual methods on protein yield, matrisome enrichment capability and the ability to isolate core matrisome and matrisome-associated components. Our data find that sodium dodecyl sulphate (SDS) decellularisation leads to the highest matrisome enrichment efficiency, while the extraction protocol that comprises chemical and trypsin digestion of the ECM fraction consistently identifies the highest number of matrisomal proteins across all types of tissue examined. Matrisome enrichment had a clear benefit over non-enriched tissue for the comprehensive identification of matrisomal components in murine liver and heart. Strikingly, we find that all four matrisome enrichment methods led to significant losses in the soluble matrisome-associated proteins across all organs. Our findings highlight the multiple factors (including tissue type, matrisome class of interest and desired enrichment purity) that influence the choice of enrichment methodology, and we anticipate that these data will serve as a useful guide for the design of future proteomic studies of the matrisome. © 2016 The Author(s).

Information Theory and Voting Based Consensus Clustering for Combining Multiple Clusterings of Chemical Structures.

PubMed

Saeed, Faisal; Salim, Naomie; Abdo, Ammar

2013-07-01

Many consensus clustering methods have been applied in different areas such as pattern recognition, machine learning, information theory and bioinformatics. However, few methods have been used for chemical compounds clustering. In this paper, an information theory and voting based algorithm (Adaptive Cumulative Voting-based Aggregation Algorithm A-CVAA) was examined for combining multiple clusterings of chemical structures. The effectiveness of clusterings was evaluated based on the ability of the clustering method to separate active from inactive molecules in each cluster, and the results were compared with Ward's method. The chemical dataset MDL Drug Data Report (MDDR) and the Maximum Unbiased Validation (MUV) dataset were used. Experiments suggest that the adaptive cumulative voting-based consensus method can improve the effectiveness of combining multiple clusterings of chemical structures. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improved block copolymer domain dispersity on chemical patterns via homopolymer-blending and molecular transfer printing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Guoliang; Nealey, Paul F.

Herein we have investigated the domain width distributions of block copolymers and their ternary blends after directed assembly on chemically patterned surfaces with and without density multiplication. On chemical patterns with density multiplication, the width of the interpolated block copolymer domains was bimodal. Once blended with the corresponding homopolymers, the block copolymers exhibited unimodal distributions of domain width due to the redistribution of homopolymers in the block copolymer domains. When the block copolymers were blended with hydroxyl-terminated homopolymers, the homopolymers with functional end-groups healed the chemical patterns and facilitated the formation of nanostructures with further improved domain width distributions. Lastly,more » it is demonstrated that the block copolymers achieved the most improved domain width distributions when directed to assemble without density multiplication on one-to-one chemical patterns generated by molecular transfer printing.« less

STUDIES ON STRUCTURAL UNITS OF THE γ-GLOBULINS

PubMed Central

Edelman, G. M.; Poulik, M. D.

1961-01-01

When human and rabbit 7S γ-globulins were reduced in strong urea solutions by a number of procedures, their molecular weights fell to approximately ⅓ of the original values. Partial separation of the reduction products was achieved using chromatography and starch gel electrophoresis in urea solutions. One of the components of reduced human 7S γ-globulin was isolated by chromatography, identified by starch gel electrophoresis, and subjected to amino acid analyses. The amino acid composition of this component differed from that of the starting material and also from that of the remaining components. A reduced pathological macroglobulin dissociated to components with an average molecular weight of 41,000. Several reduced human myeloma proteins, when subjected to starch gel electrophoresis, yielded individual patterns that nevertheless had features in common with those of reduced normal γ-globulins. Reduction of normal and abnormal γ-globulins was accompanied by the appearance of titratable sulfhydryl groups. Chemical treatments other than reduction were used to determine the type of bond holding the subunits together. It was tentatively concluded that they were linked by disulfide bonds. An hypothesis is presented to relate the structural features of the various γ-globulins in terms of the multiplicity of polypeptide chains in these molecules. PMID:13725659

Application of a two-stream radiative transfer model for leaf lignin and cellulose concentrations from spectral reflectance measurements, part 2

NASA Technical Reports Server (NTRS)

Conel, James E.; Vandenbosch, Jeannette; Grove, Cindy I.

1993-01-01

We used the Kubelka-Munk theory of diffuse spectral reflectance in layers to analyze influences of multiple chemical components in leaves. As opposed to empirical approaches to estimation of plant chemistry, the full spectral resolution of laboratory reflectance data was retained in an attempt to estimate lignin or other constituent concentrations from spectral band positions. A leaf water reflectance spectrum was derived from theoretical mixing rules, reflectance observations, and calculations from theory of intrinsic k- and s-functions. Residual reflectance bands were then isolated from spectra of fresh green leaves. These proved hard to interpret for composition in terms of simple two component mixtures such as lignin and cellulose. We next investigated spectral and dilution influences of other possible components (starch, protein). These components, among others, added to cellulose in hypothetical mixtures, produce band displacements similar to lignin, but will disguise by dilution the actual abundance of lignin present in a multicomponent system. This renders interpretation of band positions problematical. Knowledge of end-members and their spectra, and a more elaborate mixture analysis procedure may be called for. Good observational atmospheric and instrumental conditions and knowledge thereof are required for retrieval of expected subtle reflectance variations present in spectra of green vegetation.

CHEMICAL ANALYSIS METHODS FOR ATMOSPHERIC AEROSOL COMPONENTS

EPA Science Inventory

This chapter surveys the analytical techniques used to determine the concentrations of aerosol mass and its chemical components. The techniques surveyed include mass, major ions (sulfate, nitrate, ammonium), organic carbon, elemental carbon, and trace elements. As reported in...

[Comparison of Chemical Components of Essential Oil from Ocimum basilicum var. pilosum Extracted by Supercritical CO2 Fluid and Steam Distillation].

PubMed

Wang, Zhao-yu; Zheng, Jia-huan; Shi, Sheng-ying; Luo, Zhi-xiong; Ni, Shun-yu; Lin, Jing-ming

2015-11-01

To compare the chemical components of essential oil prepared by steam distillation extraction (SD) and supercritical CO2 fluid extraction (SFE-CO2) from Ocimum basilicum var. pilosum whole plant. The essential oil of Ocimum basilicum var. pilosum were extracted by SD and SFE-CO2. The chemical components of essential oil were separated and analyzed by gas chromatography-mass spectrometry( GC-MS). Their relative contents were determined by normalization of peak area. 40 and 42 compounds were detected in the essential oil prepared by SD and SFE-CO2 respectively. 25 compounds were common. Thereare significant differences of the chemical components between the Ocimum basilicum var. pilosum essential oil prepared by SD and thatby SFE-CO2. Different methods showed different extraction efficiency with a special compound. It might be a good idea to unite several methods in the modern traditional Chinese medicine industry.

[Chemical components from essential oil of Pandanus amaryllifolius leaves].

PubMed

Chen, Xiao-Kai; Ge, Fa-Huan

2014-04-01

To analyze the chemical compositions of Pandanus amaryllifolius leaves essential oil extracted by steam distillation. The essential oil of Pandanus amaryllifolius leaves was analyzed by gas chromatography-mass spectrum, and the relative content of each component was determined by area normalization method. 128 peaks were separated and 95 compounds were identified, which weighed 97.75%. The main chemical components of the essential oil were phytol (42.15%), squalene (16.81%), what's more pentadecanal (6.17%), pentadecanoic acid (4.49%), 3, 7, 11, 15-tetramethyl-2-hexadecen-1-ol (3.83%), phytone (2.05%) and the other 74 chemical compositions were firstly identified from the essential oil of Pandanus amaryllifolius leaves. The chemical compositions of Pandanu samaryllifolius leaves essential oil was systematically, deeply isolated and identified for the first time. This experiment has provided scientific foundation for further utilization of Pandanus amaryllifolius leaves.

Precondensed matter - Key to the early solar system

NASA Technical Reports Server (NTRS)

Clayton, D. D.

1978-01-01

Explicit astrophysical details are developed for the hypothesis that chemical and isotopic anomalies in primitive solar-system samples reflect routine initial chemical conditions within precondensed matter. The central feature of this theory concerns the chemical state of presolar dust, which is regarded as never having been vaporized in the region where the most chemically primitive samples (carbonaceous meteorites) accumulated. It is suggested that the initial chemical state of heavy atoms during meteorite and planetary accumulation was distributed between a refractory-mineral component from high-temperature condensation and a volatile component resulting from cold matter adhering to preexisting grains. Thermal conditions in the solar nebula are considered along with the existence of supernova condensates and other thermal condensates in the interstellar dust. Fractionation into volatile and refractory elements is idealized in terms of four distinct interstellar components, and the fractionated precondensed matter is described.

Numerical investigation of spray ignition of a multi-component fuel surrogate

NASA Astrophysics Data System (ADS)

Backer, Lara; Narayanaswamy, Krithika; Pepiot, Perrine

2014-11-01

Simulating turbulent spray ignition, an important process in engine combustion, is challenging, since it combines the complexity of multi-scale, multiphase turbulent flow modeling with the need for an accurate description of chemical kinetics. In this work, we use direct numerical simulation to investigate the role of the evaporation model on the ignition characteristics of a multi-component fuel surrogate, injected as droplets in a turbulent environment. The fuel is represented as a mixture of several components, each one being representative of a different chemical class. A reduced kinetic scheme for the mixture is extracted from a well-validated detailed chemical mechanism, and integrated into the multiphase turbulent reactive flow solver NGA. Comparisons are made between a single-component evaporation model, in which the evaporating gas has the same composition as the liquid droplet, and a multi-component model, where component segregation does occur. In particular, the corresponding production of radical species, which are characteristic of the ignition of individual fuel components, is thoroughly analyzed.

Estimation of Theaflavins (TF) and Thearubigins (TR) Ratio in Black Tea Liquor Using Electronic Vision System

NASA Astrophysics Data System (ADS)

Akuli, Amitava; Pal, Abhra; Ghosh, Arunangshu; Bhattacharyya, Nabarun; Bandhopadhyya, Rajib; Tamuly, Pradip; Gogoi, Nagen

2011-09-01

Quality of black tea is generally assessed using organoleptic tests by professional tea tasters. They determine the quality of black tea based on its appearance (in dry condition and during liquor formation), aroma and taste. Variation in the above parameters is actually contributed by a number of chemical compounds like, Theaflavins (TF), Thearubigins (TR), Caffeine, Linalool, Geraniol etc. Among the above, TF and TR are the most important chemical compounds, which actually contribute to the formation of taste, colour and brightness in tea liquor. Estimation of TF and TR in black tea is generally done using a spectrophotometer instrument. But, the analysis technique undergoes a rigorous and time consuming effort for sample preparation; also the operation of costly spectrophotometer requires expert manpower. To overcome above problems an Electronic Vision System based on digital image processing technique has been developed. The system is faster, low cost, repeatable and can estimate the amount of TF and TR ratio for black tea liquor with accuracy. The data analysis is done using Principal Component Analysis (PCA), Multiple Linear Regression (MLR) and Multiple Discriminate Analysis (MDA). A correlation has been established between colour of tea liquor images and TF, TR ratio. This paper describes the newly developed E-Vision system, experimental methods, data analysis algorithms and finally, the performance of the E-Vision System as compared to the results of traditional spectrophotometer.

[Soil organic carbon fractionation methods and their applications in farmland ecosystem research: a review].

PubMed

Zhang, Guo; Cao, Zhi-ping; Hu, Chan-juan

2011-07-01

Soil organic carbon is of heterogeneity in components. The active components are sensitive to agricultural management, while the inert components play an important role in carbon fixation. Soil organic carbon fractionation mainly includes physical, chemical, and biological fractionations. Physical fractionation is to separate the organic carbon into active and inert components based on the density, particle size, and its spatial distribution; chemical fractionation is to separate the organic carbon into various components based on the solubility, hydrolizability, and chemical reactivity of organic carbon in a variety of extracting agents. In chemical fractionation, the dissolved organic carbon is bio-available, including organic acids, phenols, and carbohydrates, and the acid-hydrolyzed organic carbon can be divided into active and inert organic carbons. Simulated enzymatic oxidation by using KMnO4 can separate organic carbon into active and non-active carbon. Biological fractionation can differentiate microbial biomass carbon and potential mineralizable carbon. Under different farmland management practices, the chemical composition and pool capacity of soil organic carbon fractions will have different variations, giving different effects on soil quality. To identify the qualitative or quantitative relationships between soil organic carbon components and carbon deposition, we should strengthen the standardization study of various fractionation methods, explore the integrated application of different fractionation methods, and sum up the most appropriate organic carbon fractionation method or the appropriate combined fractionation methods for different farmland management practices.

DAG tales: the multiple faces of diacylglycerol--stereochemistry, metabolism, and signaling.

PubMed

Eichmann, Thomas Oliver; Lass, Achim

2015-10-01

The neutral lipids diacylglycerols (DAGs) are involved in a plethora of metabolic pathways. They function as components of cellular membranes, as building blocks for glycero(phospho)lipids, and as lipid second messengers. Considering their central role in multiple metabolic processes and signaling pathways, cellular DAG levels require a tight regulation to ensure a constant and controlled availability. Interestingly, DAG species are versatile in their chemical structure. Besides the different fatty acid species esterified to the glycerol backbone, DAGs can occur in three different stereo/regioisoforms, each with unique biological properties. Recent scientific advances have revealed that DAG metabolizing enzymes generate and distinguish different DAG isoforms, and that only one DAG isoform holds signaling properties. Herein, we review the current knowledge of DAG stereochemistry and their impact on cellular metabolism and signaling. Further, we describe intracellular DAG turnover and its stereochemistry in a 3-pool model to illustrate the spatial and stereochemical separation and hereby the diversity of cellular DAG metabolism.

Soda pans of the Pannonian steppe harbor unique bacterial communities adapted to multiple extreme conditions.

PubMed

Szabó, Attila; Korponai, Kristóf; Kerepesi, Csaba; Somogyi, Boglárka; Vörös, Lajos; Bartha, Dániel; Márialigeti, Károly; Felföldi, Tamás

2017-05-01

Soda pans of the Pannonian steppe are unique environments regarding their physical and chemical characteristics: shallowness, high turbidity, intermittent character, alkaline pH, polyhumic organic carbon concentration, hypertrophic condition, moderately high salinity, sodium and carbonate ion dominance. The pans are highly productive environments with picophytoplankton predominance. Little is known about the planktonic bacterial communities inhabiting these aquatic habitats; therefore, amplicon sequencing and shotgun metagenomics were applied to reveal their composition and functional properties. Results showed a taxonomically complex bacterial community which was distinct from other soda lakes regarding its composition, e.g. the dominance of class Alphaproteobacteria was observed within phylum Proteobacteria. The shotgun metagenomic analysis revealed several functional gene components related to the harsh and at the same time hypertrophic environmental conditions, e.g. proteins involved in stress response, transport and hydrolase systems targeting phytoplankton-derived organic matter. This is the first detailed report on the indigenous planktonic bacterial communities coping with the multiple extreme conditions present in the unique soda pans of the Pannonian steppe.

Strategies for Multi-Modal Analysis

NASA Astrophysics Data System (ADS)

Hexemer, Alexander; Wang, Cheng; Pandolfi, Ronald; Kumar, Dinesh; Venkatakrishnan, Singanallur; Sethian, James; Camera Team

This section on soft materials will be dedicated to discuss the extraction of the chemical distribution and spatial arrangement of constituent elements and functional groups at multiple length scales and, thus, the examination of collective dynamics, transport, and electronic ordering phenomena. Traditional measures of structure in soft materials have relied heavily on scattering and imaging based techniques due to their capacity to measure nanoscale dimensions and their capacity to monitor structure under conditions of dynamic stress loading. Special attentions are planned to focus on the application of resonant x-ray scattering, contrast-varied neutron scattering, analytical transmission electron microscopy, and their combinations. This session aims to bring experts in both scattering and electron microscope fields to discuss recent advances in selectively characterizing structural architectures of complex soft materials, which have often multi-components with a wide range of length scales and multiple functionalities, and thus hopes to foster novel ideas to decipher a higher level of structural complexity in soft materials in future. CAMERA, Early Career Award.

Profiling and multivariate statistical analysis of Panax ginseng based on ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry.

PubMed

Wu, Wei; Sun, Le; Zhang, Zhe; Guo, Yingying; Liu, Shuying

2015-03-25

An ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) method was developed for the detection and structural analysis of ginsenosides in white ginseng and related processed products (red ginseng). Original neutral, malonyl, and chemically transformed ginsenosides were identified in white and red ginseng samples. The aglycone types of ginsenosides were determined by MS/MS as PPD (m/z 459), PPT (m/z 475), C-24, -25 hydrated-PPD or PPT (m/z 477 or m/z 493), and Δ20(21)-or Δ20(22)-dehydrated-PPD or PPT (m/z 441 or m/z 457). Following the structural determination, the UHPLC-Q-TOF-MS-based chemical profiling coupled with multivariate statistical analysis method was applied for global analysis of white and processed ginseng samples. The chemical markers present between the processed products red ginseng and white ginseng could be assigned. Process-mediated chemical changes were recognized as the hydrolysis of ginsenosides with large molecular weight, chemical transformations of ginsenosides, changes in malonyl-ginsenosides, and generation of 20-(R)-ginsenoside enantiomers. The relative contents of compounds classified as PPD, PPT, malonyl, and transformed ginsenosides were calculated based on peak areas in ginseng before and after processing. This study provides possibility to monitor multiple components for the quality control and global evaluation of ginseng products during processing. Copyright © 2014 Elsevier B.V. All rights reserved.

The role of serotonin and norepinephrine in sleep-waking activity.

PubMed

Morgane, P J; Stern, W C

1975-11-01

A critical review of the evidences relating the biogenic amines serotonin and norepinephrine to the states of slow-wave and rapid eye movement (REM) sleep is presented. Various alternative explanations for specific chemical regulation of the individual sleep states, including the phasic events of REM sleep, are evaluated within the overall framework of the monoamine theory of sleep. Several critical neuropsychopharmacological studies relating to metabolsim of the amines in relation to sleep-waking behavior are presented. Models of the chemical neuronal circuitry involved in sleep-waking activity are derived and interactions between several brainstem nuclei, particularly the raphé complex and locus coeruleus, are discussed. Activity in these aminergic systems in relation to oscillations in the sleep-waking cycles is evaluated. In particular, the assessment of single cell activity in specific chemical systems in relations to chemical models of sleep is reviewed. Overall, it appears that the biogenic amines, especially serotonin and norepinephrine, play key roles in the generation and maintenance of the sleep states. These neurotransmitters participate in some manner in the "triggering" processes necessary for actuating each sleep phase and in regulating the transitions from sleep to waking activity. The biogenic amines are, however, probably not "sleep factors" or direct inducers of the sleep states. Rather, they appear to be components of a multiplicity of interacting chemical circuitry in the brain whose activity maintains various chemical balances in different brain regions. Shifts in these balances appear to be involved in the triggering and maintenance of the various states comprising the vigilance continuum.

Multiple animal studies for medical chemical defense program in soldier/patient decontamination and drug development on task order 86-25: Evaluation of the effectiveness of two ROHM and HAAS candidate decontamination systems against percutaneous application of undiluted TGD, Gd, VX HD, and L on the laboratory albino rabbit. Final report, 1 September 1986-1 February 1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joiner, R.L.; Keys, W.B.; Harroff, H.H.

1988-02-18

A task was assigned to Battelle's Medical Research and Evaluation Facility(MREF) to evaluate the effectiveness of two candidate decontamination systems when compared to the standard dual component M258A1 decontamination system currently fielded by the U.S. Army. The chemical surety material (CSM) used in the evaluation were the organophosphates Soman (GD), polymer thickened GD (TGD), and VX, and the vesicants sulfur mustard (HD) and Lewisite (LS). The efficacies of the two candidate decontamination systems were evaluated in such a manner as to determine the LD50 and protective ratio (PR) for each decontaminant against each organophosphate CSM as compared to the standardmore » M258A1 decontamination system LD50. The PR constituted a comparison for each candidate system against the M258A1 standard. In the vesicant phase of the screen, the efficacies of the candidate systems were evaluated in a side-by-side comparison to the M258A1 decontamination system to determine whether the candidates were as good as or better than the standard dual component system.« less

The importance of quality control in validating concentrations of contaminants of emerging concern in source and treated drinking water samples.

PubMed

Batt, Angela L; Furlong, Edward T; Mash, Heath E; Glassmeyer, Susan T; Kolpin, Dana W

2017-02-01

A national-scale survey of 247 contaminants of emerging concern (CECs), including organic and inorganic chemical compounds, and microbial contaminants, was conducted in source and treated drinking water samples from 25 treatment plants across the United States. Multiple methods were used to determine these CECs, including six analytical methods to measure 174 pharmaceuticals, personal care products, and pesticides. A three-component quality assurance/quality control (QA/QC) program was designed for the subset of 174 CECs which allowed us to assess and compare performances of the methods used. The three components included: 1) a common field QA/QC protocol and sample design, 2) individual investigator-developed method-specific QA/QC protocols, and 3) a suite of 46 method comparison analytes that were determined in two or more analytical methods. Overall method performance for the 174 organic chemical CECs was assessed by comparing spiked recoveries in reagent, source, and treated water over a two-year period. In addition to the 247 CECs reported in the larger drinking water study, another 48 pharmaceutical compounds measured did not consistently meet predetermined quality standards. Methodologies that did not seem suitable for these analytes are overviewed. The need to exclude analytes based on method performance demonstrates the importance of additional QA/QC protocols. Published by Elsevier B.V.

Kinetics of homogeneous nucleation on many-component systems

NASA Technical Reports Server (NTRS)

Hirschfelder, J. O.

1974-01-01

Reiss's (1950) classical treatment of the kinetics of homogeneous nucleation in a system containing two chemical components is extended to many-component systems. The formulation is analogous to the pseudostationary-state theory of chemical reaction rates, with the free energy as a function of the composition of the embryo taking the place of the potential energy as a function of interatomic distances.

Kinetics of homogeneous nucleation in many component systems

NASA Technical Reports Server (NTRS)

Hirschfelder, J. O.

1974-01-01

Reiss's classical treatment of the kinetics of homogeneous nucleation in a system containing two chemical components is extended to many-component systems. The formulation is analogous to the pseudo-stationary state theory of chemical reaction rates with the free energy as a function of the composition of the embryo taking the place of the potential energy as a function of interatomic distances.

Measurements of the aerosol chemical composition and mixing state in the Po Valley using multiple spectroscopic techniques

NASA Astrophysics Data System (ADS)

Decesari, S.; Allan, J.; Plass-Duelmer, C.; Williams, B. J.; Paglione, M.; Facchini, M. C.; O'Dowd, C.; Harrison, R. M.; Gietl, J. K.; Coe, H.; Giulianelli, L.; Gobbi, G. P.; Lanconelli, C.; Carbone, C.; Worsnop, D.; Lambe, A. T.; Ahern, A. T.; Moretti, F.; Tagliavini, E.; Elste, T.; Gilge, S.; Zhang, Y.; Dall'Osto, M.

2014-11-01

The use of co-located multiple spectroscopic techniques can provide detailed information on the atmospheric processes regulating aerosol chemical composition and mixing state. So far, field campaigns heavily equipped with aerosol mass spectrometers have been carried out mainly in large conurbations and in areas directly affected by their outflow, whereas lesser efforts have been dedicated to continental areas characterised by a less dense urbanisation. We present here the results obtained at a background site in the Po Valley, Italy, in summer 2009. For the first time in Europe, six state-of-the-art spectrometric techniques were used in parallel: aerosol time-of-flight mass spectrometer (ATOFMS), two aerosol mass spectrometers (high-resolution time-of-flight aerosol mass spectrometer - HR-ToF-AMS and soot particle aerosol mass spectrometer - SP-AMS), thermal desorption aerosol gas chromatography (TAG), chemical ionisation mass spectrometry (CIMS) and (offline) proton nuclear magnetic resonance (1H-NMR) spectroscopy. The results indicate that, under high-pressure conditions, atmospheric stratification at night and early morning hours led to the accumulation of aerosols produced by anthropogenic sources distributed over the Po Valley plain. Such aerosols include primary components such as black carbon (BC), secondary semivolatile compounds such as ammonium nitrate and amines and a class of monocarboxylic acids which correspond to the AMS cooking organic aerosol (COA) already identified in urban areas. In daytime, the entrainment of aged air masses in the mixing layer is responsible for the accumulation of low-volatility oxygenated organic aerosol (LV-OOA) and also for the recycling of non-volatile primary species such as black carbon. According to organic aerosol source apportionment, anthropogenic aerosols accumulating in the lower layers overnight accounted for 38% of organic aerosol mass on average, another 21% was accounted for by aerosols recirculated in residual layers but still originating in northern Italy, while a substantial fraction (41%) was due to the most aged aerosols imported from transalpine areas. The different meteorological regimes also affected the BC mixing state: in periods of enhanced stagnation and recirculation of pollutants, the number fraction of the BC-containing particles determined by ATOFMS was 75% of the total, while in the days of enhanced ventilation of the planetary boundary layer (PBL), such fraction was significantly lower (50%) because of the relative greater influence of non-BC-containing aerosol local sources in the Po Valley. Overall, a full internal mixing between BC and the non-refractory aerosol chemical components was not observed during the experiment in this environment.

Clustering the Orion B giant molecular cloud based on its molecular emission

PubMed Central

Bron, Emeric; Daudon, Chloé; Pety, Jérôme; Levrier, François; Gerin, Maryvonne; Gratier, Pierre; Orkisz, Jan H.; Guzman, Viviana; Bardeau, Sébastien; Goicoechea, Javier R.; Liszt, Harvey; Öberg, Karin; Peretto, Nicolas; Sievers, Albrecht; Tremblin, Pascal

2017-01-01

Context Previous attempts at segmenting molecular line maps of molecular clouds have focused on using position-position-velocity data cubes of a single molecular line to separate the spatial components of the cloud. In contrast, wide field spectral imaging over a large spectral bandwidth in the (sub)mm domain now allows one to combine multiple molecular tracers to understand the different physical and chemical phases that constitute giant molecular clouds (GMCs). Aims We aim at using multiple tracers (sensitive to different physical processes and conditions) to segment a molecular cloud into physically/chemically similar regions (rather than spatially connected components), thus disentangling the different physical/chemical phases present in the cloud. Methods We use a machine learning clustering method, namely the Meanshift algorithm, to cluster pixels with similar molecular emission, ignoring spatial information. Clusters are defined around each maximum of the multidimensional Probability Density Function (PDF) of the line integrated intensities. Simple radiative transfer models were used to interpret the astrophysical information uncovered by the clustering analysis. Results A clustering analysis based only on the J = 1 – 0 lines of three isotopologues of CO proves suffcient to reveal distinct density/column density regimes (nH ~ 100 cm−3, ~ 500 cm−3, and > 1000 cm−3), closely related to the usual definitions of diffuse, translucent and high-column-density regions. Adding two UV-sensitive tracers, the J = 1 − 0 line of HCO+ and the N = 1 − 0 line of CN, allows us to distinguish two clearly distinct chemical regimes, characteristic of UV-illuminated and UV-shielded gas. The UV-illuminated regime shows overbright HCO+ and CN emission, which we relate to a photochemical enrichment effect. We also find a tail of high CN/HCO+ intensity ratio in UV-illuminated regions. Finer distinctions in density classes (nH ~ 7 × 103 cm−3 ~ 4 × 104 cm−3) for the densest regions are also identified, likely related to the higher critical density of the CN and HCO+ (1 – 0) lines. These distinctions are only possible because the high-density regions are spatially resolved. Conclusions Molecules are versatile tracers of GMCs because their line intensities bear the signature of the physics and chemistry at play in the gas. The association of simultaneous multi-line, wide-field mapping and powerful machine learning methods such as the Meanshift clustering algorithm reveals how to decode the complex information available in these molecular tracers. PMID:29456256

Label-free Chemical Imaging of Fungal Spore Walls by Raman Microscopy and Multivariate Curve Resolution Analysis

PubMed Central

Noothalapati, Hemanth; Sasaki, Takahiro; Kaino, Tomohiro; Kawamukai, Makoto; Ando, Masahiro; Hamaguchi, Hiro-o; Yamamoto, Tatsuyuki

2016-01-01

Fungal cell walls are medically important since they represent a drug target site for antifungal medication. So far there is no method to directly visualize structurally similar cell wall components such as α-glucan, β-glucan and mannan with high specificity, especially in a label-free manner. In this study, we have developed a Raman spectroscopy based molecular imaging method and combined multivariate curve resolution analysis to enable detection and visualization of multiple polysaccharide components simultaneously at the single cell level. Our results show that vegetative cell and ascus walls are made up of both α- and β-glucans while spore wall is exclusively made of α-glucan. Co-localization studies reveal the absence of mannans in ascus wall but are distributed primarily in spores. Such detailed picture is believed to further enhance our understanding of the dynamic spore wall architecture, eventually leading to advancements in drug discovery and development in the near future. PMID:27278218

Multivariate analysis of historical data (2004-2013) in assessing the possible environmental impact of the Bellolampo landfill (Palermo).

PubMed

Indelicato, Serena; Bongiorno, David; Tuzzolino, Nicola; Mannino, Maria Rosaria; Muscarella, Rosalia; Fradella, Pasquale; Gargano, Maria Elena; Nicosia, Salvatore; Ceraulo, Leopoldo

2018-03-14

Multivariate analysis was performed on a large data set of groundwater and leachate samples collected during 9 years of operation of the Bellolampo municipal solid waste landfill (located above Palermo, Italy). The aim was to obtain the most likely correlations among the data. The analysis results are presented. Groundwater samples were collected in the period 2004-2013, whereas the leachate analysis refers to the period 2006-2013. For groundwater, statistical data evaluation revealed notable differences among the samples taken from the numerous wells located around the landfill. Characteristic parameters revealed by principal component analysis (PCA) were more deeply investigated, and corresponding thematic maps were drawn. The composition of the leachate was also thoroughly investigated. Several chemical macro-descriptors were calculated, and the results are presented. A comparison of PCA results for the leachate and groundwater data clearly reveals that the groundwater's main components substantially differ from those of the leachate. This outcome strongly suggests excluding leachate permeation through the multiple landfill lining.

Tailoring recombinant protein quality by rational media design.

PubMed

Brühlmann, David; Jordan, Martin; Hemberger, Jürgen; Sauer, Markus; Stettler, Matthieu; Broly, Hervé

2015-01-01

Clinical efficacy and safety of recombinant proteins are closely associated with their structural characteristics. The major quality attributes comprise glycosylation, charge variants (oxidation, deamidation, and C- & N-terminal modifications), aggregates, low-molecular-weight species (LMW), and misincorporation of amino acids in the protein backbone. Cell culture media design has a great potential to modulate these quality attributes due to the vital role of medium in mammalian cell culture. The purpose of this review is to provide an overview of the way both classical cell culture medium components and novel supplements affect the quality attributes of recombinant therapeutic proteins expressed in mammalian hosts, allowing rational and high-throughput optimization of mammalian cell culture media. A selection of specific and/or potent inhibitors and activators of oligosaccharide processing as well as components affecting multiple quality attributes are presented. Extensive research efforts in this field show the feasibility of quality engineering through media design, allowing to significantly modulate the protein function. © 2015 American Institute of Chemical Engineers.

Formation Mechanism of Discoloration on Die-Cast AZ91D Components Surface After Chemical Conversion

NASA Astrophysics Data System (ADS)

Liu, Bao-sheng; Wei, Ying-hui; Hou, Li-feng

2013-01-01

A notebook (NB) computer component was manufactured from AZ91D Mg alloy by a die-casting process. After chemical conversion treatment, a discoloration was noted on the component surface. The source of this discoloration has been studied in detail by scanning electron microscopy, energy dispersive spectroscopy, and spark atomic absorption spectroscopy. The corrosion resistance was also measured by potentiodynamic polarization, hydrogen evolution and salt spray testing. The formation mechanism for the discoloration which was caused by the residue left behind by excess mold release agent sprayed during the die-casting was discussed in detail. After chemical conversion treatment, the residual-baked mold release agent was apparent on the component surface as "white ash." Consequently, it degraded seriously both the appearance and the corrosion resistance of the manufactured component.

Chemical information obtained from Auger depth profiles by means of advanced factor analysis (MLCFA)

NASA Astrophysics Data System (ADS)

De Volder, P.; Hoogewijs, R.; De Gryse, R.; Fiermans, L.; Vennik, J.

1993-01-01

The advanced multivariate statistical technique "maximum likelihood common factor analysis (MLCFA)" is shown to be superior to "principal component analysis (PCA)" for decomposing overlapping peaks into their individual component spectra of which neither the number of components nor the peak shape of the component spectra is known. An examination of the maximum resolving power of both techniques, MLCFA and PCA, by means of artificially created series of multicomponent spectra confirms this finding unambiguously. Substantial progress in the use of AES as a chemical-analysis technique is accomplished through the implementation of MLCFA. Chemical information from Auger depth profiles is extracted by investigating the variation of the line shape of the Auger signal as a function of the changing chemical state of the element. In particular, MLCFA combined with Auger depth profiling has been applied to problems related to steelcord-rubber tyre adhesion. MLCFA allows one to elucidate the precise nature of the interfacial layer of reaction products between natural rubber vulcanized on a thin brass layer. This study reveals many interesting chemical aspects of the oxi-sulfidation of brass undetectable with classical AES.

Prioritizing ToxCast Chemicals Across Multiple Sectors of Toxicity Using ToxPi

EPA Science Inventory

The Toxicological Prioritization Index (ToxPi™) framework was developed as a decision-support tool to aid in the rational prioritization of chemicals for integrated toxicity testing. ToxPi consolidates information from multiple domains—including ToxCast™ in vitro bioactivity prof...

Sensitive and reliable multianalyte quantitation of herbal medicine in rat plasma using dynamic triggered multiple reaction monitoring.

PubMed

Yan, Zhixiang; Li, Tianxue; Lv, Pin; Li, Xiang; Zhou, Chen; Yang, Xinghao

2013-06-01

There is a growing need both clinically and experimentally to improve the determination of the blood levels of multiple chemical constituents in herbal medicines. The conventional multiple reaction monitoring (cMRM), however, is not well suited for multi-component determination and could not provide qualitative information for identity confirmation. Here we apply a dynamic triggered MRM (DtMRM) algorithm for the quantification of 20 constituents in an herbal prescription Bu-Zhong-Yi-Qi-Tang (BZYQT) in rat plasma. Dynamic MRM (DMRM) dramatically reduced the number of concurrent MRM transitions that are monitored during each MS scan. This advantage has been enhanced with the addition of triggered MRM (tMRM) for simultaneous confirmation, which maximizes the dwell time in the primary MRM quantitation phase, and also acquires sufficient MRM data to create a composite product ion spectrum. By allowing optimized collision energy for each product ion and maximizing dwell times, tMRM is significantly more sensitive and reliable than conventional product ion scanning. The DtMRM approach provides much higher sensitivity and reproducibility than cMRM. Copyright © 2013 Elsevier B.V. All rights reserved.

Tuning Nb–Pt Interactions To Facilitate Fuel Cell Electrocatalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghoshal, Shraboni; Jia, Qingying; Bates, Michael K.

High stability, availability of multiple oxidation states, and accessibility within a wide electrochemical window are the prime features of Nb that make it a favorable candidate for electrocatalysis, especially when it is combined with Pt. However, Nb has been used as a support in the form of oxides in all previously reported Pt–Nb electrocatalysts, and no Pt–Nb alloying phase has been demonstrated hitherto. Herein, we report a multifunctional Pt–Nb composite (PtNb/NbOx-C) where Nb exists both as an alloying component with Pt and as an oxide support and is synthesized by means of a simple wet chemical method. In this work,more » the Pt–Nb alloy phase has been firmly verified with the help of multiple spectroscopic methods. This allows for the experimental evidence of the theoretical prediction that Pt–Nb alloy interactions improve the oxygen reduction reaction (ORR) activity of Pt. In addition, such a combination of multiphase Nb brings up myriad features encompassing increased ORR durability, immunity to phosphate anion poisoning, enhanced hydrogen oxidation reaction (HOR) activity, and oxidative carbon monoxide (CO) stripping, making this electrocatalyst useful in multiple fuel cell systems.« less

Integrated presentation of ecological risk from multiple stressors

PubMed Central

Goussen, Benoit; Price, Oliver R.; Rendal, Cecilie; Ashauer, Roman

2016-01-01

Current environmental risk assessments (ERA) do not account explicitly for ecological factors (e.g. species composition, temperature or food availability) and multiple stressors. Assessing mixtures of chemical and ecological stressors is needed as well as accounting for variability in environmental conditions and uncertainty of data and models. Here we propose a novel probabilistic ERA framework to overcome these limitations, which focusses on visualising assessment outcomes by construct-ing and interpreting prevalence plots as a quantitative prediction of risk. Key components include environmental scenarios that integrate exposure and ecology, and ecological modelling of relevant endpoints to assess the effect of a combination of stressors. Our illustrative results demonstrate the importance of regional differences in environmental conditions and the confounding interactions of stressors. Using this framework and prevalence plots provides a risk-based approach that combines risk assessment and risk management in a meaningful way and presents a truly mechanistic alternative to the threshold approach. Even whilst research continues to improve the underlying models and data, regulators and decision makers can already use the framework and prevalence plots. The integration of multiple stressors, environmental conditions and variability makes ERA more relevant and realistic. PMID:27782171

Multiple time step integrators in ab initio molecular dynamics.

PubMed

Luehr, Nathan; Markland, Thomas E; Martínez, Todd J

2014-02-28

Multiple time-scale algorithms exploit the natural separation of time-scales in chemical systems to greatly accelerate the efficiency of molecular dynamics simulations. Although the utility of these methods in systems where the interactions are described by empirical potentials is now well established, their application to ab initio molecular dynamics calculations has been limited by difficulties associated with splitting the ab initio potential into fast and slowly varying components. Here we present two schemes that enable efficient time-scale separation in ab initio calculations: one based on fragment decomposition and the other on range separation of the Coulomb operator in the electronic Hamiltonian. We demonstrate for both water clusters and a solvated hydroxide ion that multiple time-scale molecular dynamics allows for outer time steps of 2.5 fs, which are as large as those obtained when such schemes are applied to empirical potentials, while still allowing for bonds to be broken and reformed throughout the dynamics. This permits computational speedups of up to 4.4x, compared to standard Born-Oppenheimer ab initio molecular dynamics with a 0.5 fs time step, while maintaining the same energy conservation and accuracy.

Strategies to Mitigate Ammonia Release on the International Space Station

NASA Technical Reports Server (NTRS)

Macatangay, Ariel V.; Prokhorov, Kimberlee S.; Sweterlitsch, Jeffrey J.

2007-01-01

International Space Station (ISS) is crucial to its continuous operation. Off-nominal situations can arise from virtually any aspect of ISS operations. One situation of particular concern is the inadvertent release of a chemical into the ISS atmosphere. In sufficient quantities, a chemical release can render the ISS uninhabitable regardless of the chemical s toxicity as a result of its effect on the hardware used to maintain the environment. This is certainly true with system chemicals which are integral components to the function and purpose of the system. Safeguards, such as design for minimum risk, multiple containment, hazard assessments, rigorous safety reviews, and others, are in place to minimize the probability of a chemical release to the ISS environment thereby allowing the benefits of system chemicals to outweigh the risks associated with them. The thermal control system is an example of such a system. Heat generated within the ISS is transferred from the internal thermal control system (ITCS) to the external thermal control system (ETCS) via two, single-barrier interface heat exchangers (IFHX). The ITCS and ETCS are closed-loop systems which utilize water and anhydrous ammonia, respectively, as heat-transfer fluids. There is approximately 1200 lbs. (208 gallons) of anhydrous ammonia in the ETCS circulating through the two heat exchangers, transferring heat from the ITCS water lines. At the amounts present in the ETCS, anhydrous ammonia is one system chemical that can easily overwhelm the station atmosphere scrubbing capabilities and render the ISS uninhabitable in the event of a catastrophic rupture. Although safeguards have certainly minimized the risk of an ammonia release into the Station atmosphere, credible release scenarios and controls to manage these scenarios are examined.

Normalization of neuronal responses in cortical area MT across signal strengths and motion directions

PubMed Central

Xiao, Jianbo; Niu, Yu-Qiong; Wiesner, Steven

2014-01-01

Multiple visual stimuli are common in natural scenes, yet it remains unclear how multiple stimuli interact to influence neuronal responses. We investigated this question by manipulating relative signal strengths of two stimuli moving simultaneously within the receptive fields (RFs) of neurons in the extrastriate middle temporal (MT) cortex. Visual stimuli were overlapping random-dot patterns moving in two directions separated by 90°. We first varied the motion coherence of each random-dot pattern and characterized, across the direction tuning curve, the relationship between neuronal responses elicited by bidirectional stimuli and by the constituent motion components. The tuning curve for bidirectional stimuli showed response normalization and can be accounted for by a weighted sum of the responses to the motion components. Allowing nonlinear, multiplicative interaction between the two component responses significantly improved the data fit for some neurons, and the interaction mainly had a suppressive effect on the neuronal response. The weighting of the component responses was not fixed but dependent on relative signal strengths. When two stimulus components moved at different coherence levels, the response weight for the higher-coherence component was significantly greater than that for the lower-coherence component. We also varied relative luminance levels of two coherently moving stimuli and found that MT response weight for the higher-luminance component was also greater. These results suggest that competition between multiple stimuli within a neuron's RF depends on relative signal strengths of the stimuli and that multiplicative nonlinearity may play an important role in shaping the response tuning for multiple stimuli. PMID:24899674

Contrasts between chemical and physical estimates of baseflow help discern multiple sources of water contributing to rivers

NASA Astrophysics Data System (ADS)

Cartwright, I.; Gilfedder, B.; Hofmann, H.

2013-05-01

This study compares geochemical and physical methods of estimating baseflow in the upper reaches of the Barwon River, southeast Australia. Estimates of baseflow from physical techniques such as local minima and recursive digital filters are higher than those based on chemical mass balance using continuous electrical conductivity (EC). Between 2001 and 2011 the baseflow flux calculated using chemical mass balance is between 1.8 × 103 and 1.5 × 104 ML yr-1 (15 to 25% of the total discharge in any one year) whereas recursive digital filters yield baseflow fluxes of 3.6 × 103 to 3.8 × 104 ML yr-1 (19 to 52% of discharge) and the local minimum method yields baseflow fluxes of 3.2 × 103 to 2.5 × 104 ML yr-1 (13 to 44% of discharge). These differences most probably reflect how the different techniques characterise baseflow. Physical methods probably aggregate much of the water from delayed sources as baseflow. However, as many delayed transient water stores (such as bank return flow or floodplain storage) are likely to be geochemically similar to surface runoff, chemical mass balance calculations aggregate them with the surface runoff component. The mismatch between geochemical and physical estimates is greatest following periods of high discharge in winter, implying that these transient stores of water feed the river for several weeks to months. Consistent with these interpretations, modelling of bank storage indicates that bank return flows provide water to the river for several weeks after flood events. EC vs. discharge variations during individual flow events also imply that an inflow of low EC water stored within the banks or on the floodplain occurs as discharge falls. The joint use of physical and geochemical techniques allows a better understanding of the different components of water that contribute to river flow, which is important for the management and protection of water resources.

SMA OBSERVATIONS OF THE W3(OH) COMPLEX: PHYSICAL AND CHEMICAL DIFFERENTIATION BETWEEN W3(H{sub 2}O) AND W3(OH)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qin, Sheng-Li; Schilke, Peter; Sánchez-Monge, Álvaro

2015-04-10

We report on the Submillimeter Array (SMA) observations of molecular lines at 270 GHz toward the W3(OH) and W3(H{sub 2}O) complex. Although previous observations already resolved the W3(H{sub 2}O) into two or three sub-components, the physical and chemical properties of the two sources are not well constrained. Our SMA observations clearly resolved the W3(OH) and W3(H{sub 2}O) continuum cores. Taking advantage of the line fitting tool XCLASS, we identified and modeled a rich molecular spectrum in this complex, including multiple CH{sub 3}CN and CH{sub 3}OH transitions in both cores. HDO, C{sub 2}H{sub 5}CN, O{sup 13}CS, and vibrationally excited lines ofmore » HCN, CH{sub 3}CN, and CH{sub 3}OCHO were only detected in W3(H{sub 2}O). We calculate gas temperatures and column densities for both cores. The results show that W3(H{sub 2}O) has higher gas temperatures and larger column densities than W3(OH) as previously observed, suggesting physical and chemical differences between the two cores. We compare the molecular abundances in W3(H{sub 2}O) to those in the Sgr B2(N) hot core, the Orion KL hot core, and the Orion Compact Ridge, and discuss the chemical origin of specific species. An east–west velocity gradient is seen in W3(H{sub 2}O), and the extension is consistent with the bipolar outflow orientation traced by water masers and radio jets. A north–south velocity gradient across W3(OH) is also observed. However, with current observations we cannot be assured whether the velocity gradients are caused by rotation, outflow, or radial velocity differences of the sub-components of W3(OH)« less

Estimating the Concentration and Biodegradability of Organic Matter in 22 Wastewater Treatment Plants Using Fluorescence Excitation Emission Matrices and Parallel Factor Analysis

PubMed Central

Yang, Liyang; Shin, Hyun-Sang; Hur, Jin

2014-01-01

This study aimed at monitoring the changes of fluorescent components in wastewater samples from 22 Korean biological wastewater treatment plants and exploring their prediction capabilities for total organic carbon (TOC), dissolved organic carbon (DOC), biochemical oxygen demand (BOD), chemical oxygen demand (COD), and the biodegradability of the wastewater using an optical sensing technique based on fluorescence excitation emission matrices and parallel factor analysis (EEM-PARAFAC). Three fluorescent components were identified from the samples by using EEM-PARAFAC, including protein-like (C1), fulvic-like (C2) and humic-like (C3) components. C1 showed the highest removal efficiencies for all the treatment types investigated here (69% ± 26%–81% ± 8%), followed by C2 (37% ± 27%–65% ± 35%), while humic-like component (i.e., C3) tended to be accumulated during the biological treatment processes. The percentage of C1 in total fluorescence (%C1) decreased from 54% ± 8% in the influents to 28% ± 8% in the effluents, while those of C2 and C3 (%C2 and %C3) increased from 43% ± 6% to 62% ± 9% and from 3% ± 7% to 10% ± 8%, respectively. The concentrations of TOC, DOC, BOD, and COD were the most correlated with the fluorescence intensity (Fmax) of C1 (r = 0.790–0.817), as compared with the other two fluorescent components. The prediction capability of C1 for TOC, BOD, and COD were improved by using multiple regression based on Fmax of C1 and suspended solids (SS) (r = 0.856–0.865), both of which can be easily monitored in situ. The biodegradability of organic matter in BOD/COD were significantly correlated with each PARAFAC component and their combinations (r = −0.598–0.613, p < 0.001), with the highest correlation coefficient shown for %C1. The estimation capability was further enhanced by using multiple regressions based on %C1, %C2 and C3/C2 (r = −0.691). PMID:24448170

Finite-deformation phase-field chemomechanics for multiphase, multicomponent solids

NASA Astrophysics Data System (ADS)

Svendsen, Bob; Shanthraj, Pratheek; Raabe, Dierk

2018-03-01

The purpose of this work is the development of a framework for the formulation of geometrically non-linear inelastic chemomechanical models for a mixture of multiple chemical components diffusing among multiple transforming solid phases. The focus here is on general model formulation. No specific model or application is pursued in this work. To this end, basic balance and constitutive relations from non-equilibrium thermodynamics and continuum mixture theory are combined with a phase-field-based description of multicomponent solid phases and their interfaces. Solid phase modeling is based in particular on a chemomechanical free energy and stress relaxation via the evolution of phase-specific concentration fields, order-parameter fields (e.g., related to chemical ordering, structural ordering, or defects), and local internal variables. At the mixture level, differences or contrasts in phase composition and phase local deformation in phase interface regions are treated as mixture internal variables. In this context, various phase interface models are considered. In the equilibrium limit, phase contrasts in composition and local deformation in the phase interface region are determined via bulk energy minimization. On the chemical side, the equilibrium limit of the current model formulation reduces to a multicomponent, multiphase, generalization of existing two-phase binary alloy interface equilibrium conditions (e.g., KKS). On the mechanical side, the equilibrium limit of one interface model considered represents a multiphase generalization of Reuss-Sachs conditions from mechanical homogenization theory. Analogously, other interface models considered represent generalizations of interface equilibrium conditions consistent with laminate and sharp-interface theory. In the last part of the work, selected existing models are formulated within the current framework as special cases and discussed in detail.

Chemical profiling of ancient hearths reveals recurrent salmon use in Ice Age Beringia

PubMed Central

Choy, Kyungcheol; Potter, Ben A.; McKinney, Holly J.; Reuther, Joshua D.; Wang, Shiway W.; Wooller, Matthew J.

2016-01-01

Current approaches to reconstruct subsistence and dietary trends in ancient hunter-gatherer societies include stable isotope analyses, but these have focused on human remains, cooking pottery, and food residues, which are relatively rare in the archaeological record. In contrast, short-term hearths are more ubiquitous worldwide, and these features can provide valuable evidence for ancient subsistence practices, particularly when faunal remains are not preserved. To test the suitability of hearths for this purpose, we conducted multiple chemical analyses: stable carbon and nitrogen isotope analyses of total organic matter (expressed as δ13C and δ15N values) and compound-specific carbon isotope analyses of individual fatty acids (δ13C16:0 and δ13C18:0) from 17 well-preserved hearths present in three occupations dating between ∼13,200–11,500 calibrated years B.P. at the Upward Sun River (USR) site in central Alaska. We combined δ15N and δ13CFA data in a Bayesian mixing model (stable isotope analysis in R) with concentration dependency to each hearth. Our model values were tested against faunal indices, indicating a strong positive relationship between marine proportional contributions to each hearth and salmon abundance. Results of the models show substantial anadromous salmon use in multiple USR components, indicating recurrent use of the site for salmon processing during the terminal Pleistocene. Our results demonstrate that salmonid and freshwater resources were more important for late Pleistocene hunter-gatherers than previously thought and highlight the potential of chemical profiling of hearth organic residues for providing greater geographic and temporal insights into resource use by prepottery societies. PMID:27573838

Chemical profiling of ancient hearths reveals recurrent salmon use in Ice Age Beringia.

PubMed

Choy, Kyungcheol; Potter, Ben A; McKinney, Holly J; Reuther, Joshua D; Wang, Shiway W; Wooller, Matthew J

2016-08-30

Current approaches to reconstruct subsistence and dietary trends in ancient hunter-gatherer societies include stable isotope analyses, but these have focused on human remains, cooking pottery, and food residues, which are relatively rare in the archaeological record. In contrast, short-term hearths are more ubiquitous worldwide, and these features can provide valuable evidence for ancient subsistence practices, particularly when faunal remains are not preserved. To test the suitability of hearths for this purpose, we conducted multiple chemical analyses: stable carbon and nitrogen isotope analyses of total organic matter (expressed as δ(13)C and δ(15)N values) and compound-specific carbon isotope analyses of individual fatty acids (δ(13)C16:0 and δ(13)C18:0) from 17 well-preserved hearths present in three occupations dating between ∼13,200-11,500 calibrated years B.P. at the Upward Sun River (USR) site in central Alaska. We combined δ(15)N and δ(13)CFA data in a Bayesian mixing model (stable isotope analysis in R) with concentration dependency to each hearth. Our model values were tested against faunal indices, indicating a strong positive relationship between marine proportional contributions to each hearth and salmon abundance. Results of the models show substantial anadromous salmon use in multiple USR components, indicating recurrent use of the site for salmon processing during the terminal Pleistocene. Our results demonstrate that salmonid and freshwater resources were more important for late Pleistocene hunter-gatherers than previously thought and highlight the potential of chemical profiling of hearth organic residues for providing greater geographic and temporal insights into resource use by prepottery societies.

Loss of expression of TGF-βs and their receptors in chronic skin lesions induced by sulfur mustard as compared with chronic contact dermatitis patients.

PubMed

Khaheshi, Isa; Keshavarz, Saeed; Imani Fooladi, Abbas Ali; Ebrahimi, Majid; Yazdani, Samaneh; Panahi, Yunes; Shohrati, Majid; Nourani, Mohammad Reza

2011-01-14

Sulfur mustard (SM) is a blister-forming agent that has been used as a chemical weapon. Sulfur mustard can cause damage in various organs, especially the skin, respiratory system, and eyes. Generally, the multiple complications of mustard gas result from its alkalizing potency; it reacts with cellular components like DNA, RNA, proteins, and lipid membranes.TGF-β is a multi-functional cytokine with multiple biological effects ranging from cell differentiation and growth inhibition to extracellular matrix stimulation, immunosuppression, and immunomodulation. TGF-β has 3 isoforms (TGF-β 1, 2, 3) and its signaling is mediated by its receptors: R1, R2 and intracellular Smads molecules.TGF-β has been shown to have anti-inflammatory effects. TGF-βs and their receptors also have an important role in modulation of skin inflammation, proliferation of epidermal cells, and wound healing, and they have been implicated in different types of skin inflammatory disorders. Seventeen exposed SM individuals (48.47 ± 9.3 years), 17 chronic dermatitis patients (46.52 ± 14.6 years), and 5 normal controls (44.00 ± 14.6 years) were enrolled in this study.Evaluation of TGF-βs and their receptors expressions was performed by semiquantitative RT-PCR. Only TGF1 was analyzed immunohistochemically. Our results showed significant decreases in the expression percentages of TGF-β 1, 2 and R1, R2 in chemical victims in comparison with chronic dermatitis and normal subjects and significant decreases in the intensity of R1 and R2 expressions in chemical victims in comparison with chronic dermatitis and normal controls. (P value < 0.05) TGF-βs and their receptors appear to have a noticeable role in chronic inflammatory skin lesions caused by sulfur mustard.

Chemical mixtures in potable water in the U.S.

USGS Publications Warehouse

Ryker, Sarah J.

2014-01-01

In recent years, regulators have devoted increasing attention to health risks from exposure to multiple chemicals. In 1996, the US Congress directed the US Environmental Protection Agency (EPA) to study mixtures of chemicals in drinking water, with a particular focus on potential interactions affecting chemicals' joint toxicity. The task is complicated by the number of possible mixtures in drinking water and lack of toxicological data for combinations of chemicals. As one step toward risk assessment and regulation of mixtures, the EPA and the Agency for Toxic Substances and Disease Registry (ATSDR) have proposed to estimate mixtures' toxicity based on the interactions of individual component chemicals. This approach permits the use of existing toxicological data on individual chemicals, but still requires additional information on interactions between chemicals and environmental data on the public's exposure to combinations of chemicals. Large compilations of water-quality data have recently become available from federal and state agencies. This chapter demonstrates the use of these environmental data, in combination with the available toxicological data, to explore scenarios for mixture toxicity and develop priorities for future research and regulation. Occurrence data on binary and ternary mixtures of arsenic, cadmium, and manganese are used to parameterize the EPA and ATSDR models for each drinking water source in the dataset. The models' outputs are then mapped at county scale to illustrate the implications of the proposed models for risk assessment and rulemaking. For example, according to the EPA's interaction model, the levels of arsenic and cadmium found in US groundwater are unlikely to have synergistic cardiovascular effects in most areas of the country, but the same mixture's potential for synergistic neurological effects merits further study. Similar analysis could, in future, be used to explore the implications of alternative risk models for the toxicity and interaction of complex mixtures, and to identify the communities with the highest and lowest expected value for regulation of chemical mixtures.

Ultrasonic Fluid Quality Sensor System

DOEpatents

Gomm, Tyler J.; Kraft, Nancy C.; Phelps, Larry D.; Taylor, Steven C.

2003-10-21

A system for determining the composition of a multiple-component fluid and for determining linear flow comprising at least one sing-around circuit that determines the velocity of a signal in the multiple-component fluid and that is correlatable to a database for the multiple-component fluid. A system for determining flow uses two of the inventive circuits, one of which is set at an angle that is not perpendicular to the direction of flow.

Ultrasonic fluid quality sensor system

DOEpatents

Gomm, Tyler J.; Kraft, Nancy C.; Phelps, Larry D.; Taylor, Steven C.

2002-10-08

A system for determining the composition of a multiple-component fluid and for determining linear flow comprising at least one sing-around circuit that determines the velocity of a signal in the multiple-component fluid and that is correlatable to a database for the multiple-component fluid. A system for determining flow uses two of the inventive circuits, one of which is set at an angle that is not perpendicular to the direction of flow.

The Multiple Component Alternative for Gifted Education.

ERIC Educational Resources Information Center

Swassing, Ray

1984-01-01

The Multiple Component Model (MCM) of gifted education includes instruction which may overlap in literature, history, art, enrichment, languages, science, physics, math, music, and dance. The model rests on multifactored identification and requires systematic development and selection of components with ongoing feedback and evaluation. (CL)

Chemical evolution of Macondo crude oil during laboratory degradation as characterized by fluorescence EEMs and hydrocarbon composition.

PubMed

Zhou, Zhengzhen; Liu, Zhanfei; Guo, Laodong

2013-01-15

The fluorescence EEM technique, PARAFAC modeling, and hydrocarbon composition were used to characterize oil components and to examine the chemical evolution and degradation pathways of Macondo crude oil under controlled laboratory conditions. Three major fluorescent oil components were identified, with Ex/Em maxima at 226/328, 262/315, and 244/366 nm, respectively. An average degradation half-life of ∼20 d was determined for the oil components based on fluorescence EEM and hydrocarbon composition measurements, showing a dynamic chemical evolution and transformation of the oil during degradation. Dispersants appeared to change the chemical characteristics of oil, to shift the fluorescence EEM spectra, and to enhance the degradation of low-molecular-weight hydrocarbons. Photochemical degradation played a dominant role in the transformation of oil components, likely an effective degradation pathway of oil in the water column. Results from laboratory experiments should facilitate the interpretation of field-data and provide insights for understanding the fate and transport of oil components in the Gulf of Mexico. Copyright © 2012 Elsevier Ltd. All rights reserved.

A Gas-Kinetic Scheme for Multimaterial Flows and Its Application in Chemical Reaction

NASA Technical Reports Server (NTRS)

Lian, Yongsheng; Xu, Kun

1999-01-01

This paper concerns the extension of the multicomponent gas-kinetic BGK-type scheme to multidimensional chemical reactive flow calculations. In the kinetic model, each component satisfies its individual gas-kinetic BGK equation and the equilibrium states of both components are coupled in space and time due to the momentum and energy exchange in the course of particle collisions. At the same time, according to the chemical reaction rule one component can be changed into another component with the release of energy, where the reactant and product could have different gamma. Many numerical test cases are included in this paper, which show the robustness and accuracy of kinetic approach in the description of multicomponent reactive flows.

Multi-Model Comparison of Lateral Boundary Contributions to ...

EPA Pesticide Factsheets

As the National Ambient Air Quality Standards (NAAQS) for ozone become more stringent, there has been growing attention on characterizing the contributions and the uncertainties in ozone from outside the US to the ozone concentrations within the US. The third phase of the Air Quality Model Evaluation International Initiative (AQMEII3) provides an opportunity to investigate this issue through the combined efforts of multiple research groups in the US and Europe. The model results cover a range of representations of chemical and physical processes, vertical and horizontal resolutions, and meteorological fields to drive the regional chemical transport models (CTMs), all of which are important components of model uncertainty (Solazzo and Galmarini, 2016). In AQMEII3, all groups were asked to track the contribution of ozone from lateral boundary through the use of chemically inert tracers. Though the inert tracer method tends to overestimate the impact of ozone boundary conditions compared with other methods such as chemically reactive tracers and source apportionment (Baker et al., 2015), the method takes the least effort to implement in different models, and is thus useful in highlighting and understanding the process-level differences amongst the models. In this study, results from four models were included (CMAQ driven by WRF, CAMx driven by WRF, CMAQ driven by CCLM, DEHM driven by WRF). At each site, the distribution of daily maximum 8-hour ozone, and the corre

The effect of environmental chemicals on the tumor microenvironment

PubMed Central

Casey, Stephanie C.; Vaccari, Monica; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Amedei, Amedeo; Barcellos-Hoff, Mary Helen; Brown, Dustin G.; Chapellier, Marion; Christopher, Joseph; Curran, Colleen S.; Forte, Stefano; Hamid, Roslida A.; Heneberg, Petr; Koch, Daniel C.; Krishnakumar, P.K.; Laconi, Ezio; Maguer-Satta, Veronique; Marongiu, Fabio; Memeo, Lorenzo; Mondello, Chiara; Raju, Jayadev; Roman, Jesse; Roy, Rabindra; Ryan, Elizabeth P.; Ryeom, Sandra; Salem, Hosni K.; Scovassi, A.Ivana; Singh, Neetu; Soucek, Laura; Vermeulen, Louis; Whitfield, Jonathan R.; Woodrick, Jordan; Colacci, Anna Maria; Bisson, William H.; Felsher, Dean W.

2015-01-01

Potentially carcinogenic compounds may cause cancer through direct DNA damage or through indirect cellular or physiological effects. To study possible carcinogens, the fields of endocrinology, genetics, epigenetics, medicine, environmental health, toxicology, pharmacology and oncology must be considered. Disruptive chemicals may also contribute to multiple stages of tumor development through effects on the tumor microenvironment. In turn, the tumor microenvironment consists of a complex interaction among blood vessels that feed the tumor, the extracellular matrix that provides structural and biochemical support, signaling molecules that send messages and soluble factors such as cytokines. The tumor microenvironment also consists of many host cellular effectors including multipotent stromal cells/mesenchymal stem cells, fibroblasts, endothelial cell precursors, antigen-presenting cells, lymphocytes and innate immune cells. Carcinogens can influence the tumor microenvironment through effects on epithelial cells, the most common origin of cancer, as well as on stromal cells, extracellular matrix components and immune cells. Here, we review how environmental exposures can perturb the tumor microenvironment. We suggest a role for disrupting chemicals such as nickel chloride, Bisphenol A, butyltins, methylmercury and paraquat as well as more traditional carcinogens, such as radiation, and pharmaceuticals, such as diabetes medications, in the disruption of the tumor microenvironment. Further studies interrogating the role of chemicals and their mixtures in dose-dependent effects on the tumor microenvironment could have important general mechanistic implications for the etiology and prevention of tumorigenesis. PMID:26106136

Reactive oxygen species (ROS) activity of ambient fine particles (PM2.5) measured in Seoul, Korea.

PubMed

Park, Jieun; Park, Eun Ha; Schauer, James J; Yi, Seung-Muk; Heo, Jongbae

2018-05-16

Substantial increase in level of particulate matter has raised concerns in South Korea recently. Ambient particulate matter is classified as Group I carcinogen (IARC, 2013) and multiple epidemiological studies has demonstrated adverse health effects due to exposure of particulate matter. Fine particulate matter (PM 2.5 ) which has a diameter <2.5 μm is likely to penetrate deeply into lung and is known to be eliciting adverse health effects. A number of epidemiological studies have been conducted on adverse health effects of PM-related diseases and mortality rate, yet particulate matter (PM)-induced reactive oxygen species (ROS) activity at the cellular level has not been actively studied in Korea. This study assessed PM-induced oxidative potential by exposure of collected ambient PM 2.5 samples to the rat alveolar macrophage cell line. The characteristics of PM 2.5 in Korea were further characterized by linking chemical constituents and contributing sources to ROS. PM 2.5 mass concentration during the cold season was relatively higher than mass concentration during the warm season and chemical constituents except for Secondary Organic Carbon (SOC) and SO 4 2- which both showed similar trends in both the cold and cold seasons. The concentration of crustal elements was especially high during the cold season which can be an indication of long range transport of Asian dust. Water soluble organic carbon and water soluble transition metals (Cr and Zn) were also shown to be correlated to oxidative potential and metals such as As and V were shown to have a high contribution to ROS activity according to stepwise multiple linear regression. Principal Component Analysis (PCA) results identified six factors that can be interpreted as soil, mobile, industry, secondary inorganic aerosol, secondary organic aerosol and oil combustion. Moreover, through Principal Component Regression (PCR), industry, soil, mobile and SIA were shown to be statistically significant sources in a relation to ROS activity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Investigation of Air-Liquid Interface Rings in Buffer Preparation Vessels: the Role of Slip Agents.

PubMed

Shi, Ting; Ding, Wei; Kessler, Donald W; De Mas, Nuria; Weaver, Douglas G; Pathirana, Charles; Martin, Russell D; Mackin, Nancy A; Casati, Michael; Miller, Scott A; Pla, Itzcoatl A

2016-01-01

Air-liquid interface rings were observed on the side walls of stainless steel buffer vessels after certain downstream buffer preparations. Those rings were resistant to regular cleaning-in-place procedures but could be removed by manual means. To investigate the root cause of this issue, multiple analytical techniques, including liquid chromatography with tandem mass spectrometry detection (LC-MS/MS), high-resolution accurate mass liquid chromatography with mass spectrometry, nuclear magnetic resonance, Fourier transform infrared spectroscopy, and scanning electron microscopy with energy-dispersive X-ray spectroscopy have been employed to characterize the chemical composition of air-liquid interface rings. The main component of air-liquid interface rings was determined to be slip agents, and the origin of the slip agents can be traced back to their presence on raw material packaging liners. Slip agents are commonly used in plastic industry as additives to reduce the coefficient of friction during the manufacturing process of thin films. To mitigate this air-liquid interface ring issue, an alternate liner with low slip agent was identified and implemented with minimal additional cost. We have also proactively tested the packaging liners of other raw materials currently used in our downstream buffer preparation to ensure slip agent levels are appropriate. Air-liquid interface rings were observed on the side walls of stainless steel buffer vessels after certain downstream buffer preparations. To investigate the root cause of this issue, multiple analytical techniques have been employed to characterize the chemical composition of air-liquid interface rings. The main components of air-liquid interface rings were determined to be slip agents, which are common additives used in the manufacturing process of thin films. The origin of the slip agents can be traced back to their presence on certain raw material packaging liners. To mitigate this air-liquid interface ring issue, an alternate liner with low slip agent was identified and implemented. © PDA, Inc. 2016.

Hydrogen trapping under the effect of W-C mixed layers

NASA Astrophysics Data System (ADS)

Liu, N.; Huang, J.; Sato, K.; Xu, Q.; Shi, L. Q.; Wang, Y. X.

2014-03-01

The retention of hydrogen (H) isotope in plasma-facing materials (PFMs) is an important issue for next step fusion device. We used density functional theory (DFT) to study the chemical bonds of H in tungsten-carbon (W-C) mixed layers of tungsten surface, aiming to explore the retention behaviour of H in PFMs. The solubility of C in W was first calculated for revealing the phase components in W-C mixed layers. It was found that C has low solubility in W, which prefers to be segregated on the W surface. Vacancies can enhance the solution of C in W. This makes C appear somewhat carbide feature. Thus, W-C mixed layers should contain multiple phase components. H retention strongly depends on the phase components in the W-C mixed layers. The solution of C will suppress the retention of H in W no matter whether neighbouring vacancies are present, or not. Hydrocarbon precursors, which were observed in desorption experiments, prefer to form by means of H binding to C atoms in C amorphous, or in precipitators in the W-C mixed layers, while not in tungsten carbide phase or in W bulk. Our investigation reasonably explains the experimental results.

Coatings with controlled porosity and chemical properties

DOEpatents

Frye, Gregory C.; Brinker, C. Jeffrey; Doughty, Daniel H.; Bein, Thomas; Moller, Karin

1996-01-01

Coatings and sensors having both steric and chemical selectivity. Controlled porosity provides the steric selectivity, whereas chemically tailored film properties, using controlled composition or modification by coupling agents, chemical species replacement, or chemical species within pores, provide the chemical selectivity. Single or multiple layers may be provided.

Coatings with controlled porosity and chemical properties

DOEpatents

Frye, Gregory C.; Brinker, C. Jeffrey; Doughty, Daniel H.; Bein, Thomas; Moller, Karin

1993-01-01

Coatings and sensors having both steric and chemical selectivity. Controlled porosity provides the steric selectivity, whereas chemically tailored film properties, using controlled composition or modification by coupling agents, chemical species replacement, or chemical species within pores, provide the chemical selectivity. Single or multiple layers may be provided.

The dimensionality of stellar chemical space using spectra from the Apache Point Observatory Galactic Evolution Experiment

NASA Astrophysics Data System (ADS)

Price-Jones, Natalie; Bovy, Jo

2018-03-01

Chemical tagging of stars based on their similar compositions can offer new insights about the star formation and dynamical history of the Milky Way. We investigate the feasibility of identifying groups of stars in chemical space by forgoing the use of model derived abundances in favour of direct analysis of spectra. This facilitates the propagation of measurement uncertainties and does not pre-suppose knowledge of which elements are important for distinguishing stars in chemical space. We use ˜16 000 red giant and red clump H-band spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and perform polynomial fits to remove trends not due to abundance-ratio variations. Using expectation maximized principal component analysis, we find principal components with high signal in the wavelength regions most important for distinguishing between stars. Different subsamples of red giant and red clump stars are all consistent with needing about 10 principal components to accurately model the spectra above the level of the measurement uncertainties. The dimensionality of stellar chemical space that can be investigated in the H band is therefore ≲10. For APOGEE observations with typical signal-to-noise ratios of 100, the number of chemical space cells within which stars cannot be distinguished is approximately 1010±2 × (5 ± 2)n - 10 with n the number of principal components. This high dimensionality and the fine-grained sampling of chemical space are a promising first step towards chemical tagging based on spectra alone.

Chlorine Dioxide Induced Multiple Chemical Sensitivity: MMPI Validity Problems.

ERIC Educational Resources Information Center

Tentoni, Stuart C.

This paper discusses Minnesota Multiphasic Personality Inventory (MMPI) data obtained from individuals exposed to chlorine dioxide in the workplace who developed Multiple Chemical Sensitivity Syndrome. The paper explores current research on chlorine dioxide exposed persons who were misdiagnosed on the basis of MMPI interpretations. Difficulties…

USING DOSE ADDITION TO ESTIMATE CUMULATIVE RISKS FROM EXPOSURES TO MULTIPLE CHEMICALS

EPA Science Inventory

The Food Quality Protection Act (FQPA) of 1996 requires the EPA to consider the cumulative risk from exposure to multiple chemicals that have a common mechanism of toxicity. Three methods, hazard index (HI), point-of-departure index (PODI), and toxicity equivalence factor (TEF), ...

Measurements of the aerosol chemical composition and mixing state in the Po Valley using multiple spectroscopic techniques

NASA Astrophysics Data System (ADS)

Decesari, S.; Allan, J.; Plass-Duelmer, C.; Williams, B. J.; Paglione, M.; Facchini, M. C.; O'Dowd, C.; Harrison, R. M.; Gietl, J. K.; Coe, H.; Giulianelli, L.; Gobbi, G. P.; Lanconelli, C.; Carbone, C.; Worsnop, D.; Lambe, A. T.; Ahern, A. T.; Moretti, F.; Tagliavini, E.; Elste, T.; Gilde, S.; Zhang, Y.; Dall'Osto, M.

2014-04-01

The use of co-located multiple spectroscopic techniques can provide detailed information on the atmospheric processes regulating aerosol chemical composition and mixing state. So far, field campaigns heavily equipped with aerosol mass spectrometers have been carried out mainly in large conurbations and in areas directly affected by their outflow, whereas lesser efforts have been dedicated to continental areas characterized by a less dense urbanization. We present here the results obtained in San Pietro Capofiume, which is located in a sparsely inhabited sector of the Po Valley, Italy. The experiment was carried out in summer 2009 in the framework of the EUCAARI project ("European Integrated Project on Aerosol, Cloud Climate Aerosol Interaction"). For the first time in Europe, six state-of-the-art techniques were used in parallel: (1) on-line TSI aerosol time-of-flight mass spectrometer (ATOFMS), (2) on-line Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS), (3) soot particle aerosol mass spectrometer (SP-AMS), (4) on-line high resolution time-of-flight mass spectrometer-thermal desorption aerosol gas chromatograph (HR-ToFMS-TAG), (5) off-line twelve-hour resolution proton nuclear magnetic resonance (H-NMR) spectroscopy, and (6) chemical ionization mass spectrometry (CIMS) for the analysis of gas-phase precursors of secondary aerosol. Data from each aerosol spectroscopic method were analysed individually following ad-hoc tools (i.e. PMF for AMS, Art-2a for ATOFMS). The results obtained from each techniques are herein presented and compared. This allows us to clearly link the modifications in aerosol chemical composition to transitions in air mass origin and meteorological regimes. Under stagnant conditions, atmospheric stratification at night and early morning hours led to the accumulation of aerosols produced by anthropogenic sources distributed over the Po Valley plain. Such aerosols include primary components such as black carbon (BC), only partly internally mixed with secondary semivolatile compounds such as ammonium nitrate and amines. Other organic components originating from anthropogenic sources at night include monocarboxylic acids which correspond to an AMS factor analogous to the "cooking" organic aerosol (COA) already identified in urban areas. In daytime, enhanced mixing in the planetary boundary layer (PBL) along with increasing temperature determined dramatic changes in aerosol composition caused by the evaporation of semivolatile components and by the entrainment of aged aerosols transported downwards from residual layers. In other words, the entrainment of aged air masses is responsible for the accumulation of low-volatility oxygenated organic aerosol (LV-OOAs) and also for the recycling of primary species such as black carbon. The LV-OOA concentrations were shown to correlate to the simple meteorological tracers of humid PBL air produced by daytime convection over land areas. In particular, both PMF-AMS and PMF-NMR could resolve two components of LV-OOA: one from long-range transport from Central Europe, the second from recirculated PBL air from the Po Valley. According to organic aerosol source apportionment by PMF-AMS, anthropogenic aerosols accumulating in the lower layers overnight accounted for 38% of organic aerosol mass on average, another 21% was accounted for by aerosols recirculated in residual layers but still originating in North Italy, while a substantial fraction (41%) was due to the most aged aerosols imported from transalpine areas. Overall, the deployment of six state-of-the-art spectrometric techniques provided a comprehensive picture of the nature and source contributions of aerosols and aerosol precursors at a European rural site with unprecedented level of details.

Magnetically encoded luminescent composite nanoparticles through layer-by-layer self-assembly.

PubMed

Song, Erqun; Han, Weiye; Xu, Hongyan; Jiang, Yunfei; Cheng, Dan; Song, Yang; Swihart, Mark T

2014-11-03

Sensitive and rapid detection of multiple analytes and the collection of components from complex samples are important in fields ranging from bioassays/chemical assays, clinical diagnosis, to environmental monitoring. A convenient strategy for creating magnetically encoded luminescent CdTe@SiO2 @n Fe3 O4 composite nanoparticles, by using a layer-by-layer self-assembly approach based on electrostatic interactions, is described. Silica-coated CdTe quantum dots (CdTe@SiO2 ) serve as core templates for the deposition of alternating layers of Fe3 O4 magnetic nanoparticles and poly(dimethyldiallyl ammonium chloride), to construct CdTe@SiO2 @n Fe3 O4 (n=1, 2, 3, …︁) composite nanoparticles with a defined number (n) of Fe3 O4 layers. Composite nanoparticles were characterized by zeta-potential analysis, fluorescence spectroscopy, vibrating sample magnetometry, and transmission electron microscopy, which showed that the CdTe@SiO2 @n Fe3 O4 composite nanoparticles exhibited excellent luminescence properties coupled with well-defined magnetic responses. To demonstrate the utility of these magnetically encoded nanoparticles for near-simultaneous detection and separation of multiple components from complex samples, three different fluorescently labeled IgG proteins, as model targets, were identified and collected from a mixture by using the CdTe@SiO2 @n Fe3 O4 nanoparticles. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CHEMICAL AND PHYSICAL CHARACTERIZATION OF COLLAPSING LOW-MASS PRESTELLAR DENSE CORES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hincelin, U.; Commerçon, B.; Wakelam, V.

The first hydrostatic core, also called the first Larson core, is one of the first steps in low-mass star formation as predicted by theory. With recent and future high-performance telescopes, the details of these first phases are becoming accessible, and observations may confirm theory and even present new challenges for theoreticians. In this context, from a theoretical point of view, we study the chemical and physical evolution of the collapse of prestellar cores until the formation of the first Larson core, in order to better characterize this early phase in the star formation process. We couple a state-of-the-art hydrodynamical modelmore » with full gas-grain chemistry, using different assumptions for the magnetic field strength and orientation. We extract the different components of each collapsing core (i.e., the central core, the outflow, the disk, the pseudodisk, and the envelope) to highlight their specific physical and chemical characteristics. Each component often presents a specific physical history, as well as a specific chemical evolution. From some species, the components can clearly be differentiated. The different core models can also be chemically differentiated. Our simulation suggests that some chemical species act as tracers of the different components of a collapsing prestellar dense core, and as tracers of the magnetic field characteristics of the core. From this result, we pinpoint promising key chemical species to be observed.« less

Kinetics of heavy metal adsorption and desorption in soil: Developing a unified model based on chemical speciation

NASA Astrophysics Data System (ADS)

Peng, Lanfang; Liu, Paiyu; Feng, Xionghan; Wang, Zimeng; Cheng, Tao; Liang, Yuzhen; Lin, Zhang; Shi, Zhenqing

2018-03-01

Predicting the kinetics of heavy metal adsorption and desorption in soil requires consideration of multiple heterogeneous soil binding sites and variations of reaction chemistry conditions. Although chemical speciation models have been developed for predicting the equilibrium of metal adsorption on soil organic matter (SOM) and important mineral phases (e.g. Fe and Al (hydr)oxides), there is still a lack of modeling tools for predicting the kinetics of metal adsorption and desorption reactions in soil. In this study, we developed a unified model for the kinetics of heavy metal adsorption and desorption in soil based on the equilibrium models WHAM 7 and CD-MUSIC, which specifically consider metal kinetic reactions with multiple binding sites of SOM and soil minerals simultaneously. For each specific binding site, metal adsorption and desorption rate coefficients were constrained by the local equilibrium partition coefficients predicted by WHAM 7 or CD-MUSIC, and, for each metal, the desorption rate coefficients of various binding sites were constrained by their metal binding constants with those sites. The model had only one fitting parameter for each soil binding phase, and all other parameters were derived from WHAM 7 and CD-MUSIC. A stirred-flow method was used to study the kinetics of Cd, Cu, Ni, Pb, and Zn adsorption and desorption in multiple soils under various pH and metal concentrations, and the model successfully reproduced most of the kinetic data. We quantitatively elucidated the significance of different soil components and important soil binding sites during the adsorption and desorption kinetic processes. Our model has provided a theoretical framework to predict metal adsorption and desorption kinetics, which can be further used to predict the dynamic behavior of heavy metals in soil under various natural conditions by coupling other important soil processes.

Contrasts between estimates of baseflow help discern multiple sources of water contributing to rivers

NASA Astrophysics Data System (ADS)

Cartwright, I.; Gilfedder, B.; Hofmann, H.

2014-01-01

This study compares baseflow estimates using chemical mass balance, local minimum methods, and recursive digital filters in the upper reaches of the Barwon River, southeast Australia. During the early stages of high-discharge events, the chemical mass balance overestimates groundwater inflows, probably due to flushing of saline water from wetlands and marshes, soils, or the unsaturated zone. Overall, however, estimates of baseflow from the local minimum and recursive digital filters are higher than those based on chemical mass balance using Cl calculated from continuous electrical conductivity measurements. Between 2001 and 2011, the baseflow contribution to the upper Barwon River calculated using chemical mass balance is between 12 and 25% of the annual discharge with a net baseflow contribution of 16% of total discharge. Recursive digital filters predict higher baseflow contributions of 19 to 52% of discharge annually with a net baseflow contribution between 2001 and 2011 of 35% of total discharge. These estimates are similar to those from the local minimum method (16 to 45% of annual discharge and 26% of total discharge). These differences most probably reflect how the different techniques characterise baseflow. The local minimum and recursive digital filters probably aggregate much of the water from delayed sources as baseflow. However, as many delayed transient water stores (such as bank return flow, floodplain storage, or interflow) are likely to be geochemically similar to surface runoff, chemical mass balance calculations aggregate them with the surface runoff component. The difference between the estimates is greatest following periods of high discharge in winter, implying that these transient stores of water feed the river for several weeks to months at that time. Cl vs. discharge variations during individual flow events also demonstrate that inflows of high-salinity older water occurs on the rising limbs of hydrographs followed by inflows of low-salinity water from the transient stores as discharge falls. The joint use of complementary techniques allows a better understanding of the different components of water that contribute to river flow, which is important for the management and protection of water resources.

Coatings with controlled porosity and chemical properties

DOEpatents

Frye, G.C.; Brinker, C.J.; Doughty, D.H.; Bein, T.; Moller, K.

1996-12-31

Coatings and sensors are disclosed having both steric and chemical selectivity. Controlled porosity provides the steric selectivity, whereas chemically tailored film properties, using controlled composition or modification by coupling agents, chemical species replacement, or chemical species within pores, provide the chemical selectivity. Single or multiple layers may be provided. 7 figs.

Coatings with controlled porosity and chemical properties

DOEpatents

Frye, G.C.; Brinker, C.J.; Doughty, D.H.; Bein, T.; Moller, K.

1993-07-06

Coatings and sensors are described having both steric and chemical selectivity. Controlled porosity provides the steric selectivity, whereas chemically tailored film properties, using controlled composition or modification by coupling agents, chemical species replacement, or chemical species within pores, provide the chemical selectivity. Single or multiple layers may be provided.

Chemical markup, XML, and the world wide web. 6. CMLReact, an XML vocabulary for chemical reactions.

PubMed

Holliday, Gemma L; Murray-Rust, Peter; Rzepa, Henry S

2006-01-01

A set of components (CMLReact) for managing chemical and biochemical reactions has been added to CML. These can be combined to support most of the strategies for the formal representation of reactions. The elements, attributes, and types are formally defined as XMLSchema components, and their semantics are developed. New syntax and semantics in CML are reported and illustrated with 10 examples.

Steady-State Multiplicity Features of Chemically Reacting Systems.

ERIC Educational Resources Information Center

Luss, Dan

1986-01-01

Analyzes steady-state multiplicity in chemical reactors, focusing on the use of two mathematical tools, namely, the catastrophe theory and the singularity theory with a distinguished parameter. These tools can be used to determine the maximum number of possible solutions and the different types of bifurcation diagrams. (JN)

ToxPi Prioritization and Profiling of 1060 ToxCast Chemicals Across Multiple Sectors of Toxicological Concern

EPA Science Inventory

The Toxicological Prioritization Index (ToxPi™) framework was developed as a decision-support tool to aid in the prioritization of chemicals for integrated toxicity testing. ToxPi consolidates information from multiple domains - including ToxCast™ in vitro bioactivity profiles (a...

Comparison of the phenolic composition of fruit juices by single step gradient HPLC analysis of multiple components versus multiple chromatographic runs optimised for individual families.

PubMed

Bremner, P D; Blacklock, C J; Paganga, G; Mullen, W; Rice-Evans, C A; Crozier, A

2000-06-01

After minimal sample preparation, two different HPLC methodologies, one based on a single gradient reversed-phase HPLC step, the other on multiple HPLC runs each optimised for specific components, were used to investigate the composition of flavonoids and phenolic acids in apple and tomato juices. The principal components in apple juice were identified as chlorogenic acid, phloridzin, caffeic acid and p-coumaric acid. Tomato juice was found to contain chlorogenic acid, caffeic acid, p-coumaric acid, naringenin and rutin. The quantitative estimates of the levels of these compounds, obtained with the two HPLC procedures, were very similar, demonstrating that either method can be used to analyse accurately the phenolic components of apple and tomato juices. Chlorogenic acid in tomato juice was the only component not fully resolved in the single run study and the multiple run analysis prior to enzyme treatment. The single run system of analysis is recommended for the initial investigation of plant phenolics and the multiple run approach for analyses where chromatographic resolution requires improvement.

Demonstration of a rapidly-swept external cavity quantum cascade laser for atmospheric sensing applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brumfield, Brian E.; Taubman, Matthew S.; Phillips, Mark C.

2016-07-01

The application of quantum cascade lasers (QCLs) in atmospheric science for trace detection of gases has been demonstrated using sensors in point or remote sensing configurations. Many of these systems utilize single narrowly-tunable (~10 cm-1) distributed feedback (DFB-) QCLs that limit simultaneous detection to a restricted number of small chemical species like H2O or N2O. The narrow wavelength range of DFB-QCLs precludes accurate quantification of large chemical species with broad rotationally-unresolved vibrational spectra, such as volatile organic compounds, that play an important role in the chemistry of the atmosphere. External-cavity (EC-) QCL systems are available that offer tuning ranges >100more » cm-1, making them excellent IR sources for measuring multiple small and large chemical species in the atmosphere. While the broad wavelength coverage afforded by an EC system enables measurements of large chemical species, most commercial systems can only be swept over their entire wavelength range at less than 10 Hz. This prohibits broadband simultaneous measurements of multiple chemicals in plumes from natural or industrial sources where turbulence and/or chemical reactivity are resulting in rapid changes in chemical composition on sub-1s timescales. At Pacific Northwest National Laboratory we have developed rapidly-swept EC-QCL technology that acquires broadband absorption spectra (~100 cm-1) on ms timescales. The spectral resolution of this system has enabled simultaneous measurement of narrow rotationally-resolved atmospherically-broadened lines from small chemical species, while offering the broad tuning range needed to measure broadband spectral features from multiple large chemical species. In this talk the application of this technology for open-path atmospheric measurements will be discussed based on results from laboratory measurements with simulated plumes of chemicals. The performance offered by the system for simultaneous detection of multiple chemical species will be presented.« less

Demonstration of a Rapidly-Swept External Cavity Quantum Cascade Laser for Atmospheric Sensing Applications

NASA Astrophysics Data System (ADS)

Brumfield, Brian E.; Taubman, Matthew S.; Phillips, Mark C.; Suter, Jonathan D.

2016-06-01

The application of quantum cascade lasers (QCLs) in atmospheric science for trace detection of gases has been demonstrated using sensors in point or remote sensing configurations. Many of these systems utilize single narrowly-tunable (˜10 wn) distributed feedback (DFB-) QCLs that limit simultaneous detection to a restricted number of small chemical species like H2O or N2O. The narrow wavelength range of DFB-QCLs precludes accurate quantification of large chemical species with broad rotationally-unresolved vibrational spectra, such as volatile organic compounds, that play an important role in the chemistry of the atmosphere. External-cavity (EC-) QCL systems are available that offer tuning ranges greater than 100 wn, making them excellent IR sources for measuring multiple small and large chemical species in the atmosphere. While the broad wavelength coverage afforded by an EC system enables measurements of large chemical species, most commercial systems can only be swept over their entire wavelength range at less than 10 Hz. This prohibits broadband simultaneous measurements of multiple chemicals in plumes from natural or industrial sources where turbulence and/or chemical reactivity are resulting in rapid changes in chemical composition on sub-1s timescales. At Pacific Northwest National Laboratory we have developed rapidly-swept EC-QCL technology that acquires broadband absorption spectra (˜100 wn) on ms timescales. The spectral resolution of this system has enabled simultaneous measurement of narrow rotationally-resolved atmospherically-broadened lines from small chemical species, while offering the broad tuning range needed to measure broadband spectral features from multiple large chemical species. In this talk the application of this technology for open-path atmospheric measurements will be discussed based on results from laboratory measurements with simulated plumes of chemicals. The performance offered by the system for simultaneous detection of multiple chemical species will be presented. The Pacific Northwest National Laboratory is operated for the U.S. Department of Energy (DOE) by the Battelle Memorial Institute under Contract No. DE-AC05-76RL01830.

Identification of flavour additives in tobacco products to develop a flavour library.

PubMed

Krüsemann, Erna Jz; Visser, Wouter F; Cremers, Johannes Wjm; Pennings, Jeroen LA; Talhout, Reinskje

2018-01-01

This study combines chemical analysis and flavour descriptions of flavour additives used in tobacco products, and provides a starting point to build an extensive library of flavour components, useful for product surveillance. Headspace gas chromatography-mass spectrometry (GC-MS) was used to compare 22 commercially available tobacco products (cigarettes and roll-your-own) expected to have a characterising flavour and 6 commercially available products not expected to have a characterising flavour with 5 reference products (natural tobacco leaves and research cigarettes containing no flavour additives). The flavour components naturally present in the reference products were excluded from components present in commercially available products containing flavour additives. A description of the remaining flavour additives was used for categorisation. GC-MS measurements of the 33 tobacco products resulted in an overview of 186 chemical compounds. Of these, 144 were solely present in commercially available products. These 144 flavour additives were described using 62 different flavour descriptors extracted from flavour databases, which were categorised into eight groups largely based on the definition of characterising flavours from the European Tobacco Product Directive: fruit, spice, herb, alcohol, menthol, sweet, floral and miscellaneous. We developed a method to identify and describe flavour additives in tobacco products. Flavour additives consist of single flavour compounds or mixtures of multiple flavour compounds, and different combinations of flavour compounds can cause a certain flavour. A flavour library helps to detect flavour additives that are characteristic for a certain flavour, and thus can be useful for regulation of flavours in tobacco and related products. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

ChemDoodle Web Components: HTML5 toolkit for chemical graphics, interfaces, and informatics.

PubMed

Burger, Melanie C

2015-01-01

ChemDoodle Web Components (abbreviated CWC, iChemLabs, LLC) is a light-weight (~340 KB) JavaScript/HTML5 toolkit for chemical graphics, structure editing, interfaces, and informatics based on the proprietary ChemDoodle desktop software. The library uses and WebGL technologies and other HTML5 features to provide solutions for creating chemistry-related applications for the web on desktop and mobile platforms. CWC can serve a broad range of scientific disciplines including crystallography, materials science, organic and inorganic chemistry, biochemistry and chemical biology. CWC is freely available for in-house use and is open source (GPL v3) for all other uses.Graphical abstractAdd interactive 2D and 3D chemical sketchers, graphics, and spectra to websites and apps with ChemDoodle Web Components.

Mineral Fractionation during Sediment Comminution and Transport in Fluvio-Deltaic and Lacustrine Rocks of the Bradbury Group, Gale Crater, Mars

NASA Astrophysics Data System (ADS)

Siebach, K. L.; Baker, M. B.; Grotzinger, J. P.; McLennan, S. M.; Gellert, R.; Thompson, L. M.; Hurowitz, J.

2017-12-01

Mineral distribution patterns in sediments of the Bradbury group in Gale crater, interpreted from observations by the Mars Science Laboratory rover Curiosity, show the importance of transport mechanics in source-to-sink processes on Mars. The Bradbury group is comprised of basalt-derived mudstones to conglomerates exposed along the modern floor of Gale crater and analyzed along a 9-km traverse of the Curiosity rover. Over 110 bulk chemistry analyses of the rocks were acquired, along with two XRD mineralogical analyses of the mudstone. These rocks are uniquely suited for analysis of source-to-sink processes because they exhibit a wide range of compositions, but (based on multiple chemical weathering proxies) they appear to have experienced negligible cation-loss during weathering and erosion. Chemical variations between analyses correlate with sediment grain sizes, with coarser-grained rocks enriched in plagioclase components SiO2, Al2O3, and Na2O, and finer-grained rocks enriched in components of mafic minerals, consistent with grain-size sorting of mineral fractions during sediment transport. Further geochemical and mineralogical modeling supports the importance of mineral fractionation: even though the limited XRD data suggests that some fraction (if not all) of the rocks contain clays and an amorphous component, models show that 90% of the compositions measured are consistent with sorting of primary igneous minerals from a plagioclase-phyric subalkaline basalt (i.e., no corrections for cation-loss are required). The distribution of K2O, modeled as a potassium feldspar component, is an exception to the major-element trends because it does not correlate with grain size, but has an elevation-dependent signal likely correlated with the introduction of a second source material. However, the dominant compositional trends within the Bradbury group sedimentary rocks are correlated with grain size and consistent with mineral fractionation of minimally-weathered plagioclase-phyric basalts; the plagioclase phenocrysts settle into coarser deposits and the finer deposits are dominated by mafic minerals.

Nuclear magnetic resonance shielding constants and chemical shifts in linear 199Hg compounds: a comparison of three relativistic computational methods.

PubMed

Arcisauskaite, Vaida; Melo, Juan I; Hemmingsen, Lars; Sauer, Stephan P A

2011-07-28

We investigate the importance of relativistic effects on NMR shielding constants and chemical shifts of linear HgL(2) (L = Cl, Br, I, CH(3)) compounds using three different relativistic methods: the fully relativistic four-component approach and the two-component approximations, linear response elimination of small component (LR-ESC) and zeroth-order regular approximation (ZORA). LR-ESC reproduces successfully the four-component results for the C shielding constant in Hg(CH(3))(2) within 6 ppm, but fails to reproduce the Hg shielding constants and chemical shifts. The latter is mainly due to an underestimation of the change in spin-orbit contribution. Even though ZORA underestimates the absolute Hg NMR shielding constants by ∼2100 ppm, the differences between Hg chemical shift values obtained using ZORA and the four-component approach without spin-density contribution to the exchange-correlation (XC) kernel are less than 60 ppm for all compounds using three different functionals, BP86, B3LYP, and PBE0. However, larger deviations (up to 366 ppm) occur for Hg chemical shifts in HgBr(2) and HgI(2) when ZORA results are compared with four-component calculations with non-collinear spin-density contribution to the XC kernel. For the ZORA calculations it is necessary to use large basis sets (QZ4P) and the TZ2P basis set may give errors of ∼500 ppm for the Hg chemical shifts, despite deceivingly good agreement with experimental data. A Gaussian nucleus model for the Coulomb potential reduces the Hg shielding constants by ∼100-500 ppm and the Hg chemical shifts by 1-143 ppm compared to the point nucleus model depending on the atomic number Z of the coordinating atom and the level of theory. The effect on the shielding constants of the lighter nuclei (C, Cl, Br, I) is, however, negligible. © 2011 American Institute of Physics

Progress in the Visualization and Mining of Chemical and Target Spaces.

PubMed

Medina-Franco, José L; Aguayo-Ortiz, Rodrigo

2013-12-01

Chemogenomics is a growing field that aims to integrate the chemical and target spaces. As part of a multi-disciplinary effort to achieve this goal, computational methods initially developed to visualize the chemical space of compound collections and mine single-target structure-activity relationships, are being adapted to visualize and mine complex relationships in chemogenomics data sets. Similarly, the growing evidence that clinical effects are many times due to the interaction of single or multiple drugs with multiple targets, is encouraging the development of novel methodologies that are integrated in multi-target drug discovery endeavors. Herein we review advances in the development and application of approaches to generate visual representations of chemical space with particular emphasis on methods that aim to explore and uncover relationships between chemical and target spaces. Also, progress in the data mining of the structure-activity relationships of sets of compounds screened across multiple targets are discussed in light of the concept of activity landscape modeling. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multiple Classes of Environmental Chemicals are Associated ...

EPA Pesticide Factsheets

Biomonitoring of human tissues and fluids has shown that virtually all individuals, worldwide, carry a “body burden” of synthetic chemicals (Thornton et al. 2002; CDC 2009). Although the measurement of an environmental chemical in a person’s tissues or fluids is an indication of exposure, it does not by itself mean that the chemical or the exposure concentration is sufficient to cause a disease or an adverse effect. However, since humans are exposed to multiple chemicals, there may be a combination effect (e.g., additive, synergistic) on health risks associated with exposure even at low levels (Kortenkamp 2008). Further, biomonitoring studies show that humans carry a body burden of multiple classes of contaminants which are often not studied together. We used the 2003-2006 National Health and Nutrition Examination Survey to evaluate the relationship between alanine aminotransferase (ALT) and 53 environmental contaminants across six classes (metals; perfluorinated compounds [PFCs]; phthalates; phenols; coplanar and non-dioxin-like polychlorinated biphenyls [PCBs]) using a novel method.

Construction of a Linux based chemical and biological information system.

PubMed

Molnár, László; Vágó, István; Fehér, András

2003-01-01

A chemical and biological information system with a Web-based easy-to-use interface and corresponding databases has been developed. The constructed system incorporates all chemical, numerical and textual data related to the chemical compounds, including numerical biological screen results. Users can search the database by traditional textual/numerical and/or substructure or similarity queries through the web interface. To build our chemical database management system, we utilized existing IT components such as ORACLE or Tripos SYBYL for database management and Zope application server for the web interface. We chose Linux as the main platform, however, almost every component can be used under various operating systems.

A Review of Non-Chemical Stressors and Their Importance in Cumulative Risk Assessment

EPA Science Inventory

Cumulative exposure/risk assessments need to include non-chemical stressors as well as human activities and chemical data. Multiple stressor research can offer information on the interactions between chemical and non-chemical stressors needed for cumulative risk assessment resea...

Multidimensional High-Resolution Magic Angle Spinning and Solution-State NMR Characterization of 13C-labeled Plant Metabolites and Lignocellulose

PubMed Central

Mori, Tetsuya; Tsuboi, Yuuri; Ishida, Nobuhiro; Nishikubo, Nobuyuki; Demura, Taku; Kikuchi, Jun

2015-01-01

Lignocellulose, which includes mainly cellulose, hemicellulose, and lignin, is a potential resource for the production of chemicals and for other applications. For effective production of materials derived from biomass, it is important to characterize the metabolites and polymeric components of the biomass. Nuclear magnetic resonance (NMR) spectroscopy has been used to identify biomass components; however, the NMR spectra of metabolites and lignocellulose components are ambiguously assigned in many cases due to overlapping chemical shift peaks. Using our 13C-labeling technique in higher plants such as poplar samples, we demonstrated that overlapping peaks could be resolved by three-dimensional NMR experiments to more accurately assign chemical shifts compared with two-dimensional NMR measurements. Metabolites of the 13C-poplar were measured by high-resolution magic angle spinning NMR spectroscopy, which allows sample analysis without solvent extraction, while lignocellulose components of the 13C-poplar dissolved in dimethylsulfoxide/pyridine solvent were analyzed by solution-state NMR techniques. Using these methods, we were able to unambiguously assign chemical shifts of small and macromolecular components in 13C-poplar samples. Furthermore, using samples of less than 5 mg, we could differentiate between two kinds of genes that were overexpressed in poplar samples, which produced clearly modified plant cell wall components. PMID:26143886

Probabilistic lifetime strength of aerospace materials via computational simulation

NASA Technical Reports Server (NTRS)

Boyce, Lola; Keating, Jerome P.; Lovelace, Thomas B.; Bast, Callie C.

1991-01-01

The results of a second year effort of a research program are presented. The research included development of methodology that provides probabilistic lifetime strength of aerospace materials via computational simulation. A probabilistic phenomenological constitutive relationship, in the form of a randomized multifactor interaction equation, is postulated for strength degradation of structural components of aerospace propulsion systems subjected to a number of effects of primitive variables. These primitive variables often originate in the environment and may include stress from loading, temperature, chemical, or radiation attack. This multifactor interaction constitutive equation is included in the computer program, PROMISS. Also included in the research is the development of methodology to calibrate the constitutive equation using actual experimental materials data together with the multiple linear regression of that data.

Targeting the proteasome pathway.

PubMed

Tsukamoto, Sachiko; Yokosawa, Hideyoshi

2009-05-01

The ubiquitin-proteasome pathway functions as a main pathway in intracellular protein degradation and plays a vital role in almost all cellular events. Various inhibitors of this pathway have been developed for research purposes. The recent approval of bortezomib (PS-341, Velcade, a proteasome inhibitor, for the treatment of multiple myeloma has opened the way to the discovery of drugs targeting the proteasome and other components of the ubiquitin-proteasome pathway. We review the current understanding of the ubiquitin-proteasome pathway and inhibitors targeting this pathway, including proteasome inhibitors, as candidate drugs for chemical therapy. Preclinical and clinical data for inhibitors of the proteasome and the ubiquitin-proteasome pathway are discussed. The proteasome and other members in the ubiquitin-proteasome pathway have emerged as novel therapeutic targets.

Polymeric Packaging for Fully Implantable Wireless Neural Microsensors

PubMed Central

Aceros, Juan; Yin, Ming; Borton, David A.; Patterson, William R.; Bull, Christopher; Nurmikko, Arto V.

2014-01-01

We present polymeric packaging methods used for subcutaneous, fully implantable, broadband, and wireless neurosensors. A new tool for accelerated testing and characterization of biocompatible polymeric packaging materials and processes is described along with specialized test units to simulate our fully implantable neurosensor components, materials and fabrication processes. A brief description of the implantable systems is presented along with their current encapsulation methods based on polydimethylsiloxane (PDMS). Results from in-vivo testing of multiple implanted neurosensors in swine and non-human primates are presented. Finally, a novel augmenting polymer thin film material to complement the currently employed PDMS is introduced. This thin layer coating material is based on the Plasma Enhanced Chemical Vapor Deposition (PECVD) process of Hexamethyldisiloxane (HMDSO) and Oxygen (O2). PMID:23365999

Effectiveness-weighted control of cooling system components

DOEpatents

Campbell, Levi A.; Chu, Richard C.; David, Milnes P.; Ellsworth Jr., Michael J.; Iyengar, Madhusudan K.; Schmidt, Roger R.; Simmons, Robert E.

2015-12-22

Energy efficient control of cooling system cooling of an electronic system is provided based, in part, on weighted cooling effectiveness of the components. The control includes automatically determining speed control settings for multiple adjustable cooling components of the cooling system. The automatically determining is based, at least in part, on weighted cooling effectiveness of the components of the cooling system, and the determining operates to limit power consumption of at least the cooling system, while ensuring that a target temperature associated with at least one of the cooling system or the electronic system is within a desired range by provisioning, based on the weighted cooling effectiveness, a desired target temperature change among the multiple adjustable cooling components of the cooling system. The provisioning includes provisioning applied power to the multiple adjustable cooling components via, at least in part, the determined control settings.

Identification of nodes and internodes of chopped biomass stems by Image analysis

USDA-ARS?s Scientific Manuscript database

Separating the morphological components of biomass leads to better handling, more efficient processing as well as value added product generation, as these components vary in their chemical composition and can be preferentially utilized. Nodes and internodes of biomass stems have distinct chemical co...

Emission characteristics and chemical components of size-segregated particulate matter in iron and steel industry

NASA Astrophysics Data System (ADS)

Jia, Jia; Cheng, Shuiyuan; Yao, Sen; Xu, Tiebing; Zhang, Tingting; Ma, Yuetao; Wang, Hongliang; Duan, Wenjiao

2018-06-01

As one of the highest energy consumption and pollution industries, the iron and steel industry is regarded as a most important source of particulate matter emission. In this study, chemical components of size-segregated particulate matters (PM) emitted from different manufacturing units in iron and steel industry were sampled by a comprehensive sampling system. Results showed that the average particle mass concentration was highest in sintering process, followed by puddling, steelmaking and then rolling processes. PM samples were divided into eight size fractions for testing the chemical components, SO42- and NH4+ distributed more into fine particles while most of the Ca2+ was concentrated in coarse particles, the size distribution of mineral elements depended on the raw materials applied. Moreover, local database with PM chemical source profiles of iron and steel industry were built and applied in CMAQ modeling for simulating SO42- and NO3- concentration, results showed that the accuracy of model simulation improved with local chemical source profiles compared to the SPECIATE database. The results gained from this study are expected to be helpful to understand the components of PM in iron and steel industry and contribute to the source apportionment researches.

Chemical Discrimination of Cortex Phellodendri amurensis and Cortex Phellodendri chinensis by Multivariate Analysis Approach.

PubMed

Sun, Hui; Wang, Huiyu; Zhang, Aihua; Yan, Guangli; Han, Ying; Li, Yuan; Wu, Xiuhong; Meng, Xiangcai; Wang, Xijun

2016-01-01

As herbal medicines have an important position in health care systems worldwide, their current assessment, and quality control are a major bottleneck. Cortex Phellodendri chinensis (CPC) and Cortex Phellodendri amurensis (CPA) are widely used in China, however, how to identify species of CPA and CPC has become urgent. In this study, multivariate analysis approach was performed to the investigation of chemical discrimination of CPA and CPC. Principal component analysis showed that two herbs could be separated clearly. The chemical markers such as berberine, palmatine, phellodendrine, magnoflorine, obacunone, and obaculactone were identified through the orthogonal partial least squared discriminant analysis, and were identified tentatively by the accurate mass of quadruple-time-of-flight mass spectrometry. A total of 29 components can be used as the chemical markers for discrimination of CPA and CPC. Of them, phellodenrine is significantly higher in CPC than that of CPA, whereas obacunone and obaculactone are significantly higher in CPA than that of CPC. The present study proves that multivariate analysis approach based chemical analysis greatly contributes to the investigation of CPA and CPC, and showed that the identified chemical markers as a whole should be used to discriminate the two herbal medicines, and simultaneously the results also provided chemical information for their quality assessment. Multivariate analysis approach was performed to the investigate the herbal medicineThe chemical markers were identified through multivariate analysis approachA total of 29 components can be used as the chemical markers. UPLC-Q/TOF-MS-based multivariate analysis method for the herbal medicine samples Abbreviations used: CPC: Cortex Phellodendri chinensis, CPA: Cortex Phellodendri amurensis, PCA: Principal component analysis, OPLS-DA: Orthogonal partial least squares discriminant analysis, BPI: Base peaks ion intensity.

Systematic considerations in the area of multiple chemical sensitivity.

PubMed Central

Benignus, V A

1997-01-01

Many workers who speculate about multiple chemical sensitivity (MCS) have devised a large number of hypothetical constructs designed to explain the phenomena. Too often these are not logically connected to the larger body of scientific thought but instead appeal to ideas not documented in accessible literature and often appearing metaphysical in nature. PMID:9167984

Facilitating High School Students' Use of Multiple Representations to Describe and Explain Simple Chemical Reactions

ERIC Educational Resources Information Center

Chandrasegaran, A. L.; Treagust, David F.; Mocerino, Mauro

2011-01-01

This study involved the evaluation of the efficacy of a planned instructional program to facilitate understanding of the macroscopic, submicroscopic and symbolic representational systems when describing and explaining chemical reactions by sixty-five Grade 9 students in a Singapore secondary school. A two-tier multiple-choice diagnostic instrument…

An Informatics Approach to Evaluating Combined Chemical Exposures from Consumer Products: A Case Study of Asthma-Associated Chemicals and Potential Endocrine Disruptors.

PubMed

Gabb, Henry A; Blake, Catherine

2016-08-01

Simultaneous or sequential exposure to multiple environmental stressors can affect chemical toxicity. Cumulative risk assessments consider multiple stressors but it is impractical to test every chemical combination to which people are exposed. New methods are needed to prioritize chemical combinations based on their prevalence and possible health impacts. We introduce an informatics approach that uses publicly available data to identify chemicals that co-occur in consumer products, which account for a significant proportion of overall chemical load. Fifty-five asthma-associated and endocrine disrupting chemicals (target chemicals) were selected. A database of 38,975 distinct consumer products and 32,231 distinct ingredient names was created from online sources, and PubChem and the Unified Medical Language System were used to resolve synonymous ingredient names. Synonymous ingredient names are different names for the same chemical (e.g., vitamin E and tocopherol). Nearly one-third of the products (11,688 products, 30%) contained ≥ 1 target chemical and 5,229 products (13%) contained > 1. Of the 55 target chemicals, 31 (56%) appear in ≥ 1 product and 19 (35%) appear under more than one name. The most frequent three-way chemical combination (2-phenoxyethanol, methyl paraben, and ethyl paraben) appears in 1,059 products. Further work is needed to assess combined chemical exposures related to the use of multiple products. The informatics approach increased the number of products considered in a traditional analysis by two orders of magnitude, but missing/incomplete product labels can limit the effectiveness of this approach. Such an approach must resolve synonymy to ensure that chemicals of interest are not missed. Commonly occurring chemical combinations can be used to prioritize cumulative toxicology risk assessments. Gabb HA, Blake C. 2016. An informatics approach to evaluating combined chemical exposures from consumer products: a case study of asthma-associated chemicals and potential endocrine disruptors. Environ Health Perspect 124:1155-1165; http://dx.doi.org/10.1289/ehp.1510529.

Survey of sensitizing components of oxidative hair dyes (retail and professional products) in Germany.

PubMed

Kirchlechner, Stephan; Hübner, Anja; Uter, Wolfgang

2016-07-01

Components of oxidative hair dyes, such as p-toluylenediamine, are very potent contact sensitizers to which many consumers as well as hairdressers and their clients are commonly exposed. Based on the qualitative composition of both retail and professional haircare products as determined by package labeling (according to INCI), we conducted a survey on the exposure to active components of oxidative hair dyes in Germany. The joint occurrence of components is also discussed. Nearly all of the 20 most commonly used substances are potent or very potent contact sensitizers. Contained in 88 % of all products, p-toluylenediamine is the most common component. There are only minor differences between retail and professional products. A frequent combination of substances includes p-toluylenediamine (sulfate), resorcinol as well as m-aminophenol. However, their actual concentrations (which were not investigated in this study) may vastly differ depending on the shade of the individual hair dye. Descriptive univariate analysis reveals that the currently used patch test series "Hairdressing Chemicals", as recommended by the German Contact Allergy Research Group (DKG), does not adequately cover the spectrum of allergens consumers and professionals are exposed to. Other studies have also suggested that a number of other allergens should be tested as well. Taking into account the dynamic kinetics of oxidative hair dyes with respect to allergy development, the effects of combined simultaneous exposure to multiple allergens on the risk of sensitization requires further research. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

The nature of the mineral component of bone and the mechanism of calcification.

PubMed

Glimcher, M J

1987-01-01

From the physical chemical standpoint, the formation of a solid phase of Ca-P in bone represents a phase transformation, a process exemplified by the formation of ice from water. Considering the structural complexity and abundance of highly organized macromolecules in the cells and extracellular tissue spaces of mineralized tissues generally and in bone particularly, it is inconceivable that this phase transformation occurs by homogeneous nucleation, i.e., without the active participation of an organic component acting as a nucleator. This is almost surely true in biologic mineralization in general. Electron micrographs and low-angle neutron and X-ray diffraction studies clearly show that calcification of collagen fibrils occurs in an extremely intimate and highly organized fashion: initiation of crystal formation within the collagen fibrils in the hole zone region, with the long axes (c-axis) of the crystals aligned roughly parallel to the long axis of the fibril within which they are located. Crystals are initially formed in hole zone regions within individual fibrils separated by unmineralized regions. Calcification is initiated in spatially distinct nucleation sites. This indicates that such regions within a single, undirectional fibril represents independent sites for heterogeneous nucleation. Clearly, sites where mineralization is initiated in adjacent collagen fibrils are even further separated, emphasizing even more clearly that the process of progressive calcification of the collagen fibrils and therefore of the tissue is characterized principally by the presence of increasing numbers of independent nucleation sites within additional hole zone regions of the collagen fibrils. The increase in the mass of Ca-P apatite accrues principally by multiplication of more crystals, mostly by secondary nucleation from the crystals initially deposited in the hole zone region. Very little additional growth of the crystals occurs with time, the additional increase in mineral mass being principally the result of increase in the number of crystals (multiplication), not size of the crystals (crystal growth). The crystals within the collagen fibers grow in number and possibly in size to extend into the overlap zone of the collagen fibrils ("pores") so that all of the available space within the fibrils, which has possibly expanded in volume from its uncalcified level, is eventually occupied by the mineral crystals. It must be recognized that the calcification of separate tissue components and compartments (collagen, mitochondria, matrix vesicles) must be an independent physical chemical event.(ABSTRACT TRUNCATED AT 400 WORDS)

Versatile protein recognition by the encoded display of multiple chemical elements on a constant macrocyclic scaffold

NASA Astrophysics Data System (ADS)

Li, Yizhou; De Luca, Roberto; Cazzamalli, Samuele; Pretto, Francesca; Bajic, Davor; Scheuermann, Jörg; Neri, Dario

2018-03-01

In nature, specific antibodies can be generated as a result of an adaptive selection and expansion of lymphocytes with suitable protein binding properties. We attempted to mimic antibody-antigen recognition by displaying multiple chemical diversity elements on a defined macrocyclic scaffold. Encoding of the displayed combinations was achieved using distinctive DNA tags, resulting in a library size of 35,393,112. Specific binders could be isolated against a variety of proteins, including carbonic anhydrase IX, horseradish peroxidase, tankyrase 1, human serum albumin, alpha-1 acid glycoprotein, calmodulin, prostate-specific antigen and tumour necrosis factor. Similar to antibodies, the encoded display of multiple chemical elements on a constant scaffold enabled practical applications, such as fluorescence microscopy procedures or the selective in vivo delivery of payloads to tumours. Furthermore, the versatile structure of the scaffold facilitated the generation of protein-specific chemical probes, as illustrated by photo-crosslinking.

Changes in monosaccharides, organic acids and amino acids during Cabernet Sauvignon wine ageing based on a simultaneous analysis using gas chromatography-mass spectrometry.

PubMed

Zhang, Xin-Ke; Lan, Yi-Bin; Zhu, Bao-Qing; Xiang, Xiao-Feng; Duan, Chang-Qing; Shi, Ying

2018-01-01

Monosaccharides, organic acids and amino acids are the important flavour-related components in wines. The aim of this article is to develop and validate a method that could simultaneously analyse these compounds in wine based on silylation derivatisation and gas chromatography-mass spectrometry (GC-MS), and apply this method to the investigation of the changes of these compounds and speculate upon their related influences on Cabernet Sauvignon wine flavour during wine ageing. This work presented a new approach for wine analysis and provided more information concerning red wine ageing. This method could simultaneously quantitatively analyse 2 monosaccharides, 8 organic acids and 13 amino acids in wine. A validation experiment showed good linearity, sensitivity, reproducibility and recovery. Multiple derivatives of five amino acids have been found but their effects on quantitative analysis were negligible, except for methionine. The evolution pattern of each category was different, and we speculated that the corresponding mechanisms involving microorganism activities, physical interactions and chemical reactions had a great correlation with red wine flavours during ageing. Simultaneously quantitative analysis of monosaccharides, organic acids and amino acids in wine was feasible and reliable and this method has extensive application prospects. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

A survey of liquid chromatographic-mass spectrometric analysis of mercapturic acid biomarkers in occupational and environmental exposure monitoring.

PubMed

Mathias, Patricia I; B'Hymer, Clayton

2014-08-01

High-performance liquid chromatography/mass spectrometry (HPLC/MS) is sensitive and specific for targeted quantitative analysis and is readily utilized for small molecules from biological matrices. This brief review describes recent selected HPLC/MS methods for the determination of urinary mercapturic acids (mercapturates) which are useful as biomarkers in characterizing human exposure to electrophilic industrial chemicals in occupational and environmental studies. Electrophilic compounds owing to their reactivity are used in chemical and industrial processes. They are present in industrial emissions, are combustion products of fossil fuels, and are components in tobacco smoke. Their presence in both the industrial and general environments are of concern for human and environmental health. Urinary mercapturates which are the products of metabolic detoxification of reactive chemicals provide a non-invasive tool to investigate human exposure to electrophilic toxicants. Selected recent mercapturate quantification methods are summarized and specific cases are presented. The biological formation of mercapturates is introduced and their use as biomarkers of metabolic processing of electrophilic compounds is discussed. Also, the use of liquid chromatography/tandem mass spectrometry in simultaneous determinations of the mercapturates of multiple parent compounds in a single determination is considered, as well as future trends and limitations in this area of research. Published by Elsevier B.V.

An Integrated Strategy for Global Qualitative and Quantitative Profiling of Traditional Chinese Medicine Formulas: Baoyuan Decoction as a Case

NASA Astrophysics Data System (ADS)

Ma, Xiaoli; Guo, Xiaoyu; Song, Yuelin; Qiao, Lirui; Wang, Wenguang; Zhao, Mingbo; Tu, Pengfei; Jiang, Yong

2016-12-01

Clarification of the chemical composition of traditional Chinese medicine formulas (TCMFs) is a challenge due to the variety of structures and the complexity of plant matrices. Herein, an integrated strategy was developed by hyphenating ultra-performance liquid chromatography (UPLC), quadrupole time-of-flight (Q-TOF), hybrid triple quadrupole-linear ion trap mass spectrometry (Qtrap-MS), and the novel post-acquisition data processing software UNIFI to achieve automatic, rapid, accurate, and comprehensive qualitative and quantitative analysis of the chemical components in TCMFs. As a proof-of-concept, the chemical profiling of Baoyuan decoction (BYD), which is an ancient TCMF that is clinically used for the treatment of coronary heart disease that consists of Ginseng Radix et Rhizoma, Astragali Radix, Glycyrrhizae Radix et Rhizoma Praeparata Cum Melle, and Cinnamomi Cortex, was performed. As many as 236 compounds were plausibly or unambiguously identified, and 175 compounds were quantified or relatively quantified by the scheduled multiple reaction monitoring (sMRM) method. The findings demonstrate that the strategy integrating the rapidity of UNIFI software, the efficiency of UPLC, the accuracy of Q-TOF-MS, and the sensitivity and quantitation ability of Qtrap-MS provides a method for the efficient and comprehensive chemome characterization and quality control of complex TCMFs.

Portable open-path chemical sensor using a quantum cascade laser

NASA Astrophysics Data System (ADS)

Corrigan, Paul; Lwin, Maung; Huntley, Reuven; Chhabra, Amandeep; Moshary, Fred; Gross, Barry; Ahmed, Samir

2009-05-01

Remote sensing of enemy installations or their movements by trace gas detection is a critical but challenging military objective. Open path measurements over ranges of a few meters to many kilometers with sensitivity in the parts per million or billion regime are crucial in anticipating the presence of a threat. Previous approaches to detect ground level chemical plumes, explosive constituents, or combustion have relied on low-resolution, short range Fourier transform infrared spectrometer (FTIR), or low-sensitivity near-infrared differential optical absorption spectroscopy (DOAS). As mid-infrared quantum cascade laser (QCL) sources have improved in cost and performance, systems based on QCL's that can be tailored to monitor multiple chemical species in real time are becoming a viable alternative. We present the design of a portable, high-resolution, multi-kilometer open path trace gas sensor based on QCL technology. Using a tunable (1045-1047cm-1) QCL, a modeled atmosphere and link-budget analysis with commercial component specifications, we show that with this approach, accuracy in parts per billion ozone or ammonia can be obtained in seconds at path lengths up to 10 km. We have assembled an open-path QCL sensor based on this theoretical approach at City College of New York, and we present preliminary results demonstrating the potential of QCLs in open-path sensing applications.

DNA decorated carbon nanotube sensors on CMOS circuitry for environmental monitoring

NASA Astrophysics Data System (ADS)

Liu, Yu; Chen, Chia-Ling; Agarwal, V.; Li, Xinghui; Sonkusale, S.; Dokmeci, Mehmet R.; Wang, Ming L.

2010-04-01

Single-walled carbon nanotubes (SWNTs) with their large surface area, high aspect ratio are one of the novel materials which have numerous attractive features amenable for high sensitivity sensors. Several nanotube based sensors including, gas, chemical and biosensors have been demonstrated. Moreover, most of these sensors require off chip components to detect the variations in the signals making them complicated and hard to commercialize. Here we present a novel complementary metal oxide semiconductor (CMOS) integrated carbon nanotube sensors for portable high sensitivity chemical sensing applications. Multiple zincation steps have been developed to ascertain proper electrical connectivity between the carbon nanotubes and the foundry made CMOS circuitry. The SWNTs have been integrated onto (CMOS) circuitry as the feedback resistor of a Miller compensated operational amplifier utilizing low temperature Dielectrophoretic (DEP) assembly process which has been tailored to be compatible with the post-CMOS integration at the die level. Building nanotube sensors directly on commercial CMOS circuitry allows single chip solutions eliminating the need for long parasitic lines and numerous wire bonds. The carbon nanotube sensors realized on CMOS circuitry show strong response to various vapors including Dimethyl methylphosphonate and Dinitrotoluene. The remarkable set of attributes of the SWNTs realized on CMOS electronic chips provides an attractive platform for high sensitivity portable nanotube based bio and chemical sensors.

Burst and Principal Components Analyses of MEA Data for 16 Chemicals Describe at Least Three Effects Classes.

EPA Science Inventory

Microelectrode arrays (MEAs) detect drug and chemical induced changes in neuronal network function and have been used for neurotoxicity screening. As a proof-•of-concept, the current study assessed the utility of analytical "fingerprinting" using Principal Components Analysis (P...

BEHAVIORAL MOMENTUM AND ACCUMULATION OF MASS IN MULTIPLE SCHEDULES

PubMed Central

Craig, Andrew R.; Cunningham, Paul J.; Shahan, Timothy A.

2015-01-01

Behavioral momentum theory suggests that the relation between a discriminative-stimulus situation and reinforcers obtained in that context (i.e., the Pavlovian stimulus–reinforcer relation) governs persistence of operant behavior. Within the theory, a mass-like aspect of behavior has been shown to be a power function of predisruption reinforcement rates. Previous investigations of resistance to change in multiple schedules, however, have been restricted to examining response persistence following protracted periods of stability in reinforcer rates within a discriminative situation. Thus, it is unclear how long a stimulus–reinforcer relation must be in effect prior to disruption in order to affect resistance to change. The present experiment examined resistance to change of pigeon’s key pecking following baseline conditions where reinforcer rates that were correlated with discriminative-stimulus situations changed. Across conditions, one multiple-schedule component arranged either relatively higher rates or lower rates of variable-interval food delivery, while the other component arranged the opposite rate. These schedules alternated between multiple-schedule components across blocks of sessions such that reinforcer rates in the components were held constant for 20, 5, 3, 2, or 1 session(s) between alternations. Resistance to extinction was higher in the component that most recently was associated with higher rates of food delivery in all conditions except when schedules alternated daily or every other day. These data suggest that resistance to change in multiple schedules is related to recently experienced reinforcer rates but only when multiple-schedule components are associated with specific reinforcer rates for several sessions. PMID:25787824

Chemical composition measurements of the low activity waste (LAW) EPA-Series glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fox, K.; Edwards, T. B.

2016-03-01

In this report, the Savannah River National Laboratory provides chemical analysis results for a series of simulated low activity waste glasses provided by Pacific Northwest National Laboratory as part of an ongoing development task. The measured chemical composition data are reported and compared with the targeted values for each component for each glass. A detailed review showed no indications of errors in the preparation or measurement of the study glasses. All of the measured sums of oxides for the study glasses fell within the interval of 100.2 to 100.8 wt %, indicating recovery of all components. Comparisons of the targetedmore » and measured chemical compositions showed that the measured values for the glasses met the targeted concentrations within 10% for those components present at more than 5 wt %.« less

The study of multiphase flow control during odor reproduction

NASA Astrophysics Data System (ADS)

Luo, Dehan; Yu, Hao; Fan, Danjun; He, Meiqiu

2014-04-01

Odor reproduction, is the use of the chemical composition of the basic components of odor recipe, according to a certain proportion, to control the flow of the various components, which make them sufficiently blended to achieve reproduction. In this paper, reproducing method is to find the corresponding liquid flavor, and then based on chemical flavor recipes, using flowmeters to control the chemical composition of the liquid flavor ratio. In the proportional control, the liquid chemical composition is very likely to be volatile, so that the proportional control is multiphase flow control. Measurement of the flow control will directly affect the odor reproducible results. Using electronic nose to obtain reproducible odor data, and then use pattern recognition algorithm to determine reproducible results. The experimental results can be achieved on the process of odor components multiphase flow proportional control parameter adjustment.

Multiple components in restriction enzyme digests of mammalian (insectivore), avian and reptilian genomic DNA hybridize with murine immunoglobulin VH probes.

PubMed

Litman, G W; Berger, L; Jahn, C L

1982-06-11

High molecular weight genomic DNAs isolated from an insectivore, Tupaia, and a representative reptilian, Caiman, and avian, Gallus, were digested with restriction endonucleases transferred to nitrocellulose and hybridized with nick-translated probes of murine VH genes. The derivations of the probes designated S107V (1) and mu 107V (2,3) have been described previously. Under conditions of reduced stringency, multiple hybridizing components were observed with Tupaia and Caiman; only mu mu 107V exhibited significant hybridization with the separated fragments of Gallus DNA. The nick-translated S107V probe was digested with Fnu4H1 and subinserts corresponding to the 5' and 3' regions both detected multiple hybridizing components in Tupaia and Caiman DNA. A 5' probe lacking the leader sequence identified the same components as the intact 5' probe, suggesting that VH coding regions distant as the reptilians may possess multiple genetic components which exhibit significant homology with murine immunoglobulin in VH regions.

Multiple components in restriction enzyme digests of mammalian (insectivore), avian and reptilian genomic DNA hybridize with murine immunoglobulin VH probes.

PubMed Central

Litman, G W; Berger, L; Jahn, C L

1982-01-01

High molecular weight genomic DNAs isolated from an insectivore, Tupaia, and a representative reptilian, Caiman, and avian, Gallus, were digested with restriction endonucleases transferred to nitrocellulose and hybridized with nick-translated probes of murine VH genes. The derivations of the probes designated S107V (1) and mu 107V (2,3) have been described previously. Under conditions of reduced stringency, multiple hybridizing components were observed with Tupaia and Caiman; only mu mu 107V exhibited significant hybridization with the separated fragments of Gallus DNA. The nick-translated S107V probe was digested with Fnu4H1 and subinserts corresponding to the 5' and 3' regions both detected multiple hybridizing components in Tupaia and Caiman DNA. A 5' probe lacking the leader sequence identified the same components as the intact 5' probe, suggesting that VH coding regions distant as the reptilians may possess multiple genetic components which exhibit significant homology with murine immunoglobulin in VH regions. Images PMID:6285298

[Construction of multiple drug release system based on components of traditional Chinese medicine].

PubMed

Liu, Dan; Jia, Xiaobin; Yu, Danhong; Zhang, Zhenhai; Sun, E

2012-08-01

With the development of the modernization drive of traditional Chinese medicine (TCM) preparations, new-type TCM dosage forms research have become a hot spot in the field. Because of complexity of TCM components as well as uncertainty of material base, there is still not a scientific system for modern TCM dosage forms so far. Modern TCM preparations inevitably take the nature of the multi-component and the general function characteristics of multi-link and multi-target into account. The author suggests building a multiple drug release system for TCM using diverse preparation techniques and drug release methods at levels on the basis the nature and function characteristics of TCM components. This essay expounds elaborates the ideas to build the multiple traditional Chinese medicine release system, theoretical basis, preparation techniques and assessment system, current problems and solutions, in order to build a multiple TCM release system with a view of enhancing the bioavailability of TCM components and provide a new form for TCM preparations.

The Effect of Shock on the Amorphous Component in Altered Basalt

NASA Technical Reports Server (NTRS)

Eckley, S. A.; Wright, S. P.; Rampe, E. B.; Niles, P. B.

2017-01-01

Investigation of the geochemical and mineralogical composition of the Martian surface provides insight into the geologic history of the predominantly basaltic crust. The Chemistry and Mineralogy (CheMin) instrument onboard the Curiosity rover has returned the first X-Ray diffraction data from the Martian surface. However, large proportions (27 +/- 14 with some estimates as high as 50 weight percentage) of an amorphous component have been reported. As a remedy to this problem, mass balance equations using geochemistry, volatile chemistry, and mineralogy have been employed to constrain the geochemistry of the amorphous component. However, "the nature and number of amorphous phases that constitute the amorphous component is not unequivocally known". Multiple hypotheses have been proposed to explain the origin of this amorphous component: Allophane (Al2O); Basaltic glass (Volcanic and impact); Palagonite (Altered basaltic glass); Hisingerite (Fe (sup 3 plus)-bearing phyllosilicate); S/Cl-rich component (sulfates and/or akaganeite); Nanophase ferric oxide component (npOx). Establishing a multi-phase amorphous component from a basaltic precursor that has undergone physical and chemical weathering within geochemical constraints is of paramount importance to better understand the composition of a large portion of the Martian surface (up to 50 weight percentage). Shocked basalts from Lonar Crater in India are valuable analogs for the Martian surface because it is a well-preserved impact crater in a basaltic target. Having undergone pre- and post-shock aqueous alteration, these rocks provide crucial data regarding the effect of shock on the amorphous component in altered basalt. By conducting mass balance equations similar to what has been performed for Gale crater materials, we attempt to calculate the geochemistry of the amorphous component in altered basalts ranging from unshocked to Class 5 (Table 1). This has the potential to reveal the nature and origin (i.e. primary igneous, shock metamorphic, and/or aqueous alteration occurring before or after the impact event) of the amorphous component in shocked basalt with the goal of unravelling the history of the Martian surface.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsigabu Gebrehiwet; James R. Henriksen; Luanjing Guo

Multi-component mineral precipitation in porous, subsurface environments is challenging to simulate or engineer when in situ reactant mixing is controlled by diffusion. In contrast to well-mixed systems, the conditions that favor mineral precipitation in porous media are distributed along chemical gradients, which evolve spatially due to concurrent mineral precipitation and modification of solute transport in the media. The resulting physical and chemical characteristics of a mixing/precipitation zone are a consequence of coupling between transport and chemical processes, and the distinctive properties of individual chemical systems. We examined the spatial distribution of precipitates formed in “double diffusion” columns for two chemicalmore » systems, calcium carbonate and calcium phosphate. Polyacrylamide hydrogel was used as a low permeability, high porosity medium to maximize diffusive mixing and minimize pressure- and density-driven flow between reactant solutions. In the calcium phosphate system, multiple, visually dense and narrow bands of precipitates were observed that were reminiscent of previously reported Liesegang patterns. In the calcium carbonate system, wider precipitation zones characterized by more sparse distributions of precipitates and a more open channel structure were observed. In both cases, formation of precipitates inhibited, but did not necessarily eliminate, continued transport and mixing of the reactants. A reactive transport model with fully implicit coupling between diffusion, chemical speciation and precipitation kinetics, but where explicit details of nucleation processes were neglected, was able to qualitatively simulate properties of the precipitation zones. The results help to illustrate how changes in the physical properties of a precipitation zone depend on coupling between diffusion-controlled reactant mixing and chemistry-specific details of precipitation kinetics.« less

Solid-phase synthesis and chemical space analysis of a 190-membered alkaloid/terpenoid-like library

PubMed Central

Moura-Letts, Gustavo; DiBlasi, Christine M.; Bauer, Renato A.; Tan, Derek S.

2011-01-01

Alkaloid and terpenoid natural products display an extensive array of chemical frameworks and biological activities. However such scaffolds remain underrepresented in current screening collections and are, thus, attractive targets for the synthesis of natural product-based libraries that access underexploited regions of chemical space. Recently, we reported a systematic approach to the stereoselective synthesis of multiple alkaloid/terpenoid-like scaffolds using transition metal-mediated cycloaddition and cyclization reactions of enyne and diyne substrates assembled on a tert-butylsulfinamide lynchpin. We report herein the synthesis of a 190-membered library of alkaloid/terpenoid-like molecules using this synthetic approach. Translation to solid-phase synthesis was facilitated by the use of a tert-butyldiarylsilyl (TBDAS) linker that closely mimics the tert-butyldiphenysilyl protecting group used in the original solution-phase route development work. Unexpected differences in stereoselectivity and regioselectivity were observed in some reactions when carried out on solid support. Further, the sulfinamide moiety could be hydrolyzed or oxidized efficiently without compromising the TBDAS linker to provide additional amine and sulfonamide functionalities. Principal component analysis of the structural and physicochemical properties of these molecules confirmed that they access regions of chemical space that overlap with bona fide natural products and are distinct from areas addressed by conventional synthetic drugs and drug-like molecules. The influences of scaffolds and substituents were also evaluated, with both found to have significant impacts on location in chemical space and three-dimensional shape. Broad biological evaluation of this library will provide valuable insights into the abilities of natural product-based libraries to access similarly underexploited regions of biological space. PMID:21451137

Oral LD50 toxicity modeling and prediction of per- and polyfluorinated chemicals on rat and mouse.

PubMed

Bhhatarai, Barun; Gramatica, Paola

2011-05-01

Quantitative structure-activity relationship (QSAR) analyses were performed using the LD(50) oral toxicity data of per- and polyfluorinated chemicals (PFCs) on rodents: rat and mouse. PFCs are studied under the EU project CADASTER which uses the available experimental data for prediction and prioritization of toxic chemicals for risk assessment by using the in silico tools. The methodology presented here applies chemometrical analysis on the existing experimental data and predicts the toxicity of new compounds. QSAR analyses were performed on the available 58 mouse and 50 rat LD(50) oral data using multiple linear regression (MLR) based on theoretical molecular descriptors selected by genetic algorithm (GA). Training and prediction sets were prepared a priori from available experimental datasets in terms of structure and response. These sets were used to derive statistically robust and predictive (both internally and externally) models. The structural applicability domain (AD) of the models were verified on 376 per- and polyfluorinated chemicals including those in REACH preregistration list. The rat and mouse endpoints were predicted by each model for the studied compounds, and finally 30 compounds, all perfluorinated, were prioritized as most important for experimental toxicity analysis under the project. In addition, cumulative study on compounds within the AD of all four models, including two earlier published models on LC(50) rodent analysis was studied and the cumulative toxicity trend was observed using principal component analysis (PCA). The similarities and the differences observed in terms of descriptors and chemical/mechanistic meaning encoded by descriptors to prioritize the most toxic compounds are highlighted.

A Selective-Echo Method for Chemical-Shift Imaging of Two-Component Systems

NASA Astrophysics Data System (ADS)

Gerald, Rex E., II; Krasavin, Anatoly O.; Botto, Robert E.

A simple and effective method for selectively imaging either one of two chemical species in a two-component system is presented and demonstrated experimentally. The pulse sequence employed, selective- echo chemical- shift imaging (SECSI), is a hybrid (frequency-selective/ T1-contrast) technique that is executed in a short period of time, utilizes the full Boltzmann magnetization of each chemical species to form the corresponding image, and requires only hard pulses of quadrature phase. This approach provides a direct and unambiguous representation of the spatial distribution of the two chemical species. In addition, the performance characteristics and the advantages of the SECSI sequence are compared on a common basis to those of other pulse sequences.

Absolute parameters and chemical composition of the binary star OU Gem

NASA Astrophysics Data System (ADS)

Glazunova, L. V.; Mishenina, T. V.; Soubiran, C.; Kovtyukh, V. V.

2014-10-01

The absolute parameters and chemical composition of the BY Dra-type spectroscopic binary OU Gem (HD 45088) were determined on the basis of 10 high-resolution spectra. A new orbital solution of the binary system was determined, the binary ephemerides were specified, and the main physical and atmospheric parameters of the binary components were obtained. The chemical composition of both components was estimated for the first time for the stars of such type.

Discovery of characteristic chemical markers for classification of aconite herbs by chromatographic profile and probabilistic neural network.

PubMed

Yang, Hua; Gao, Wen; Liu, Lei; Liu, Ke; Liu, E-Hu; Qi, Lian-Wen; Li, Ping

2015-11-10

Most Aconitum species, also known as aconite, are extremely poisonous, so it must be identified carefully. Differentiation of Aconitum species is challenging because of their similar appearance and chemical components. In this study, a universal strategy to discover chemical markers was developed for effective authentication of three commonly used aconite roots. The major procedures include: (1) chemical profiling and structural assignment of herbs by liquid chromatography with mass spectrometry (LC-MS), (2) quantification of major components by LC-MS, (3) probabilistic neural network (PNN) model to calculate contributions of components toward species classification, (4) discovery of minimized number of chemical markers for quality control. The MS fragmentation pathways of diester-, monoester-, and alkyloyamine-diterpenoid alkaloids were compared. Using these rules, 42 aconite alkaloids were identified in aconite roots. Subsequently, 11 characteristic compounds were quantified. A component-species modeling by PNN was then established combining the 11 analytes and 26-batch samples from three aconite species. The contribution of each analyte to species classification was calculated. Selection of fuziline, benzoylhypaconine, and talatizamine, or a combination of more compounds based on a contribution order, can be used for successful categorization of the three aconite species. Collectively, the proposed strategy is beneficial to selection of rational chemical markers for the species classification and quality control of herbal medicines. Copyright © 2015 Elsevier B.V. All rights reserved.

Health Outcomes of Exposure to Biological and Chemical Components of Inhalable and Respirable Particulate Matter

PubMed Central

Morakinyo, Oyewale Mayowa; Mokgobu, Matlou Ingrid; Mukhola, Murembiwa Stanley; Hunter, Raymond Paul

2016-01-01

Particulate matter (PM) is a key indicator of air pollution and a significant risk factor for adverse health outcomes in humans. PM is not a self-contained pollutant but a mixture of different compounds including chemical and biological fractions. While several reviews have focused on the chemical components of PM and associated health effects, there is a dearth of review studies that holistically examine the role of biological and chemical components of inhalable and respirable PM in disease causation. A literature search using various search engines and (or) keywords was done. Articles selected for review were chosen following predefined criteria, to extract and analyze data. The results show that the biological and chemical components of inhalable and respirable PM play a significant role in the burden of health effects attributed to PM. These health outcomes include low birth weight, emergency room visit, hospital admission, respiratory and pulmonary diseases, cardiovascular disease, cancer, non-communicable diseases, and premature death, among others. This review justifies the importance of each or synergistic effects of the biological and chemical constituents of PM on health. It also provides information that informs policy on the establishment of exposure limits for PM composition metrics rather than the existing exposure limits of the total mass of PM. This will allow for more effective management strategies for improving outdoor air quality. PMID:27314370

Health Outcomes of Exposure to Biological and Chemical Components of Inhalable and Respirable Particulate Matter.

PubMed

Morakinyo, Oyewale Mayowa; Mokgobu, Matlou Ingrid; Mukhola, Murembiwa Stanley; Hunter, Raymond Paul

2016-06-14

Particulate matter (PM) is a key indicator of air pollution and a significant risk factor for adverse health outcomes in humans. PM is not a self-contained pollutant but a mixture of different compounds including chemical and biological fractions. While several reviews have focused on the chemical components of PM and associated health effects, there is a dearth of review studies that holistically examine the role of biological and chemical components of inhalable and respirable PM in disease causation. A literature search using various search engines and (or) keywords was done. Articles selected for review were chosen following predefined criteria, to extract and analyze data. The results show that the biological and chemical components of inhalable and respirable PM play a significant role in the burden of health effects attributed to PM. These health outcomes include low birth weight, emergency room visit, hospital admission, respiratory and pulmonary diseases, cardiovascular disease, cancer, non-communicable diseases, and premature death, among others. This review justifies the importance of each or synergistic effects of the biological and chemical constituents of PM on health. It also provides information that informs policy on the establishment of exposure limits for PM composition metrics rather than the existing exposure limits of the total mass of PM. This will allow for more effective management strategies for improving outdoor air quality.

Blends of Pheromones, With and Without Host Plant Volatiles, Can Attract Multiple Species of Cerambycid Beetles Simultaneously

Treesearch

L.M. Hanks; J.A. Mongold-Diers; T.H. Atkinson; M.K. Fierke; M.D. Ginzel; E.E. Graham; T.M. Poland; A.B. Richards; M.L. Richardson; J.G. Millar

2018-01-01

Pheromone components of cerambycid beetles are often conserved, with a given compound serving as a pheromone component for multiple related species, including species native to different continents. Consequently, a single synthesized compound may attract multiple species to a trap simultaneously. Furthermore, our previous research in east-central Illinois had...

AN EVALUATION OF ANTECEDENT EXERCISE ON BEHAVIOR MAINTAINED BY AUTOMATIC REINFORCEMENT USING A THREE-COMPONENT MULTIPLE SCHEDULE

PubMed Central

Morrison, Heather; Roscoe, Eileen M; Atwell, Amy

2011-01-01

We evaluated antecedent exercise for treating the automatically reinforced problem behavior of 4 individuals with autism. We conducted preference assessments to identify leisure and exercise items that were associated with high levels of engagement and low levels of problem behavior. Next, we conducted three 3-component multiple-schedule sequences: an antecedent-exercise test sequence, a noncontingent leisure-item control sequence, and a social-interaction control sequence. Within each sequence, we used a 3-component multiple schedule to evaluate preintervention, intervention, and postintervention effects. Problem behavior decreased during the postintervention component relative to the preintervention component for 3 of the 4 participants during the exercise-item assessment; however, the effects could not be attributed solely to exercise for 1 of these participants. PMID:21941383

Mathematical modelling of oil spill fate and transport in the marine environment incorporating biodegradation kinetics of oil droplets

NASA Astrophysics Data System (ADS)

Spanoudaki, Katerina

2016-04-01

Oil biodegradation by native bacteria is one of the most important natural processes that can attenuate the environmental impacts of marine oil spills. However, very few numerical models of oil spill fate and transport include biodegradation kinetics of spilled oil. Furthermore, in models where biodegradation is included amongst the oil transformation processes simulated, it is mostly represented as a first order decay process neglecting the effect of several important parameters that can limit biodegradation rate, such as oil composition and oil droplets-water interface. To this end, the open source numerical model MEDSKIL-II, which simulates oil spill fate and transport in the marine environment, has been modified to include biodegradation kinetics of oil droplets dispersed in the water column. MEDSLIK-II predicts the transport and weathering of oil spills following a Lagrangian approach for the solution of the advection-diffusion equation. Transport is governed by the 3D sea currents and wave field provided by ocean circulation models. In addition to advective and diffusive displacements, the model simulates several physical and chemical processes that transform the oil (evaporation, emulsification, dispersion in the water column, adhesion to coast). The fate algorithms employed in MEDSLIK-II consider the oil as a uniform substance whose properties change as the slick weathers, an approach that can lead to reduced accuracy, especially in the estimation of oil evaporation and biodegradation. Therefore MEDSLIK-II has been modified by adopting the "pseudo-component" approach for simulating weathering processes. Spilled oil is modelled as a relatively small number of discrete, non-interacting components (pseudo-components). Chemicals in the oil mixture are grouped by physical-chemical properties and the resulting pseudo-component behaves as if it were a single substance with characteristics typical of the chemical group. The fate (evaporation, dispersion, biodegradation) of each component is tracked separately. Biodegradation of oil droplets is modelled by Monod kinetics. The kinetics of oil particles size reduction due to the microbe-mediated degradation at water-oil particle interface is represented by the shrinking core model. In order to test the performance of the modified MEDSLIK-II model, it has been applied to a test case built-in the original code. The total fate of the oil spill is simulated both without biodegradation kinetics and when biodegradation is taken into account, for reasons of comparison. Several parameters that control biodegradation rate, including initial oil concentration and composition, size distribution of oil droplets and initial microbial concentration have been investigated. This upgraded version of MEDSLIK-II can be useful not only for predicting the transport and fate of spilled oil in the short term but also for evaluating different bioremediation strategies and risk assessment for the mid- and long term. Acknowledgements: The financial support by the EU project DECATASTROPHIZE: Use of SDSS and MCDA to Prepare for Disasters or Plan for Multiple Hazards, GA no. ECHO/SUB/2015/713788/PREP02, is greatly acknowledged.

Mechanical Fluidity of Fully Suspended Biological Cells

PubMed Central

Maloney, John M.; Lehnhardt, Eric; Long, Alexandra F.; Van Vliet, Krystyn J.

2013-01-01

Mechanical characteristics of single biological cells are used to identify and possibly leverage interesting differences among cells or cell populations. Fluidity—hysteresivity normalized to the extremes of an elastic solid or a viscous liquid—can be extracted from, and compared among, multiple rheological measurements of cells: creep compliance versus time, complex modulus versus frequency, and phase lag versus frequency. With multiple strategies available for acquisition of this nondimensional property, fluidity may serve as a useful and robust parameter for distinguishing cell populations, and for understanding the physical origins of deformability in soft matter. Here, for three disparate eukaryotic cell types deformed in the suspended state via optical stretching, we examine the dependence of fluidity on chemical and environmental influences at a timescale of ∼1 s. We find that fluidity estimates are consistent in the time and frequency domains under a structural damping (power-law or fractional-derivative) model, but not under an equivalent-complexity, lumped-component (spring-dashpot) model; the latter predicts spurious time constants. Although fluidity is suppressed by chemical cross-linking, we find that ATP depletion in the cell does not measurably alter the parameter, and we thus conclude that active ATP-driven events are not a crucial enabler of fluidity during linear viscoelastic deformation of a suspended cell. Finally, by using the capacity of optical stretching to produce near-instantaneous increases in cell temperature, we establish that fluidity increases with temperature—now measured in a fully suspended, sortable cell without the complicating factor of cell-substratum adhesion. PMID:24138852

Modeling Biogeochemical Cycling of Heavy Metals in Lake Coeur d'Alene Sediments

NASA Astrophysics Data System (ADS)

Sengor, S. S.; Spycher, N.; Belding, E.; Curthoys, K.; Ginn, T. R.

2005-12-01

Mining of precious metals since the late 1800's have left Lake Coeur d'Alene (LCdA) sediments heavily enriched with toxic metals, including Cd, Cu, Pb, and Zn. Indigenous microbes however are capable of catalyzing reactions that detoxify the benthic and aqueous lake environments, and thus constitute an important driving component in the biogeochemical cycles of these metals. Here we report on the development of a quantitative model of transport, fate, exposure and effects of toxic compounds on benthic microbial communities at LCdA. First, chemical data from the LCdA area have been compiled from multiple sources to investigate trends in chemical occurrence, as well as to define model boundary conditions. The model is structured as 1-D diffusive reactive transport model to simulate spatial and temporal distribution of metals through the benthic sediments. Inorganic reaction processes included in the model are aqueous speciation, surface complexation, mineral precipitation/dissolution and abiotic redox reactions. Simulations with and without surface complexation are carried out to evaluate the effect of sorption and the conservative behaviour of metals within the benthic sediments under abiotic and purely diffusive transport. The 1-D inorganic diffusive transport model is then coupled to a biotic reaction network including consortium biodegradation kinetics with multiple electron acceptors, product toxicity, and energy partitioning. Multiyear simulations are performed, with water column chemistry established as a boundary condition from extant data, to explore the role of biogeochemical dynamics on benthic fluxes of metals in the long term.

Multiple pass laser amplifier system

DOEpatents

Brueckner, Keith A.; Jorna, Siebe; Moncur, N. Kent

1977-01-01

A laser amplification method for increasing the energy extraction efficiency from laser amplifiers while reducing the energy flux that passes through a flux limited system which includes apparatus for decomposing a linearly polarized light beam into multiple components, passing the components through an amplifier in delayed time sequence and recombining the amplified components into an in phase linearly polarized beam.

21 CFR 1310.13 - Exemption of chemical mixtures; application.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Exemption of chemical mixtures; application. 1310... REPORTS OF LISTED CHEMICALS AND CERTAIN MACHINES § 1310.13 Exemption of chemical mixtures; application. (a... application of all or any part of the Act a chemical mixture consisting of two or more chemical components, at...

21 CFR 1310.13 - Exemption of chemical mixtures; application.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Exemption of chemical mixtures; application. 1310... REPORTS OF LISTED CHEMICALS AND CERTAIN MACHINES § 1310.13 Exemption of chemical mixtures; application. (a... application of all or any part of the Act a chemical mixture consisting of two or more chemical components, at...

21 CFR 1310.13 - Exemption of chemical mixtures; application.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 9 2013-04-01 2013-04-01 false Exemption of chemical mixtures; application. 1310... REPORTS OF LISTED CHEMICALS AND CERTAIN MACHINES § 1310.13 Exemption of chemical mixtures; application. (a... application of all or any part of the Act a chemical mixture consisting of two or more chemical components, at...

21 CFR 1310.13 - Exemption of chemical mixtures; application.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 9 2014-04-01 2014-04-01 false Exemption of chemical mixtures; application. 1310... REPORTS OF LISTED CHEMICALS AND CERTAIN MACHINES § 1310.13 Exemption of chemical mixtures; application. (a... application of all or any part of the Act a chemical mixture consisting of two or more chemical components, at...

21 CFR 1310.13 - Exemption of chemical mixtures; application.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 9 2012-04-01 2012-04-01 false Exemption of chemical mixtures; application. 1310... REPORTS OF LISTED CHEMICALS AND CERTAIN MACHINES § 1310.13 Exemption of chemical mixtures; application. (a... application of all or any part of the Act a chemical mixture consisting of two or more chemical components, at...

A multi-reference filtered-x-Newton narrowband algorithm for active isolation of vibration and experimental investigations

NASA Astrophysics Data System (ADS)

Wang, Chun-yu; He, Lin; Li, Yan; Shuai, Chang-geng

2018-01-01

In engineering applications, ship machinery vibration may be induced by multiple rotational machines sharing a common vibration isolation platform and operating at the same time, and multiple sinusoidal components may be excited. These components may be located at frequencies with large differences or at very close frequencies. A multi-reference filtered-x Newton narrowband (MRFx-Newton) algorithm is proposed to control these multiple sinusoidal components in an MIMO (multiple input and multiple output) system, especially for those located at very close frequencies. The proposed MRFx-Newton algorithm can decouple and suppress multiple sinusoidal components located in the same narrow frequency band even though such components cannot be separated from each other by a narrowband-pass filter. Like the Fx-Newton algorithm, good real-time performance is also achieved by the faster convergence speed brought by the 2nd-order inverse secondary-path filter in the time domain. Experiments are also conducted to verify the feasibility and test the performance of the proposed algorithm installed in an active-passive vibration isolation system in suppressing the vibration excited by an artificial source and air compressor/s. The results show that the proposed algorithm not only has comparable convergence rate as the Fx-Newton algorithm but also has better real-time performance and robustness than the Fx-Newton algorithm in active control of the vibration induced by multiple sound sources/rotational machines working on a shared platform.

Chemopreventive effects of combination of honokiol and magnolol with α-santalol on skin cancer developments.

PubMed

Chilampalli, C; Zhang, X; Kaushik, R S; Young, A; Zeman, D; Hildreth, M B; Fahmy, H; Dwivedi, C

2013-06-01

α-Santalol is active component of sandalwood oil and has been shown to have chemopreventive effects against chemically and UVB-induced skin cancer development in mice. α-Santalol is also shown to have skin permeation enhancing effects. Honokiol and magnolol isolated from Magnolia officinalis bark extract have also been shown to have chemopreventive effects against chemically and UVB-induced skin cancer in mice. This study was conducted to investigate the combination effects of α-santalol, honokiol and magnolol to study any additive/synergistic effects to lower the doses required for chemoprevention. Pretreatment of combinations of α-santalol with honokiol and magnolol significantly decreased tumor multiplicity upto 75% than control, α-santalol, honokiol and magnolol alone in SKH-1 mice. Combination of α-santalol with honokiol and magnolol also decreased cell viability, proliferation, and enhanced apotosis in comparison to α-santalol, honokiol and magnolol alone in Human epidrmoid carcinoma A431 cells. Overall, the results of present study indicated combinations of α-santalol with honokiol and magnolol could provide chemoprevention of skin cancer at lower doses than given alone.

Chemical composition and antibacterial activities of Illicium verum against antibiotic-resistant pathogens.

PubMed

Yang, Jyh-Ferng; Yang, Cheng-Hong; Chang, Hsueh-Wei; Yang, Cheng-San; Wang, Shao-Ming; Hsieh, Ming-Che; Chuang, Li-Yeh

2010-10-01

In recent years, human pathogenic microorganisms have developed multiple drug resistance and caused serious nosocomial infections. In this study, we identified four new antimicrobial compounds from the Chinese herbal medicine Illicium verum and assessed their antibacterial efficacies. The supercritical CO₂ and ethanol extracts of Illicium verum showed substantial antibacterial activity against 67 clinical drug-resistant isolates, including 27 Acinetobacter baumannii, 20 Pseudomonas aeruginosa, and 20 methicillin-resistant Staphylococcus aureus. The diethyl ether (EE) fraction obtained from partition extraction and supercritical CO₂ extracts revealed an antibacterial activity with a minimum inhibitory concentration value of 0.15-0.70 mg/mL and 0.11 mg/mL, respectively. The EE fraction of I. verum showed synergetic effects with some commercial antibiotics. The antimicrobial mechanism was investigated with killing curves and scanning electron microscopy observation. The chemical components of the extracts were analyzed by spectrophotometry; (E)-anethole, anisyl acetone, anisyl alcohol, and anisyl aldehyde exhibited antibacterial activity against different clinical isolates. These extracts from I. verum can be further developed into antibiotic medicines due to their proven antibacterial activity.

Chemical-Specific Representation of Air-Soil Exchange and Soil Penetration in Regional Multimedia Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

McKone, T.E.; Bennett, D.H.

2002-08-01

In multimedia mass-balance models, the soil compartment is an important sink as well as a conduit for transfers to vegetation and shallow groundwater. Here a novel approach for constructing soil transport algorithms for multimedia fate models is developed and evaluated. The resulting algorithms account for diffusion in gas and liquid components; advection in gas, liquid, or solid phases; and multiple transformation processes. They also provide an explicit quantification of the characteristic soil penetration depth. We construct a compartment model using three and four soil layers to replicate with high reliability the flux and mass distribution obtained from the exact analyticalmore » solution describing the transient dispersion, advection, and transformation of chemicals in soil with fixed properties and boundary conditions. Unlike the analytical solution, which requires fixed boundary conditions, the soil compartment algorithms can be dynamically linked to other compartments (air, vegetation, ground water, surface water) in multimedia fate models. We demonstrate and evaluate the performance of the algorithms in a model with applications to benzene, benzo(a)pyrene, MTBE, TCDD, and tritium.« less

Polyclonal and monoclonal antibodies in clinic.

PubMed

Wootla, Bharath; Denic, Aleksandar; Rodriguez, Moses

2014-01-01

Immunoglobulins (Ig) or antibodies are heavy plasma proteins, with sugar chains added to amino-acid residues by N-linked glycosylation and occasionally by O-linked glycosylation. The versatility of antibodies is demonstrated by the various functions that they mediate such as neutralization, agglutination, fixation with activation of complement and activation of effector cells. Naturally occurring antibodies protect the organism against harmful pathogens, viruses and infections. In addition, almost any organic chemical induces antibody production of antibodies that would bind specifically to the chemical. These antibodies are often produced from multiple B cell clones and referred to as polyclonal antibodies. In recent years, scientists have exploited the highly evolved machinery of the immune system to produce structurally and functionally complex molecules such as antibodies from a single B clone, heralding the era of monoclonal antibodies. Most of the antibodies currently in the clinic, target components of the immune system, are not curative and seek to alleviate symptoms rather than cure disease. Our group used a novel strategy to identify reparative human monoclonal antibodies distinct from conventional antibodies. In this chapter, we discuss the therapeutic relevance of both polyclonal and monoclonal antibodies in clinic.

Chemical synthesis and structural characterization of small AuZn nanoparticles

NASA Astrophysics Data System (ADS)

Juárez-Ruiz, E.; Pal, U.; Lombardero-Chartuni, J. A.; Medina, A.; Ascencio, J. A.

2007-03-01

In this paper, we report the aqueous synthesis of bimetallic Au-Zn nanoparticles of different compositions by the simultaneous reduction technique. The stability and atomic configuration of the particles are studied through high-resolution transmission electron microscopy (HRTEM) and UV-Vis optical absorption techniques. Depending on the composition, small bimetallic nanoparticles of 1 15 nm in size were obtained. The average size and size distribution of the bimetallic nanoparticles are seen to be critically dependent on the atomic ratio of the constituting elements Au and Zn. While a 1:1 atomic proportion of Au and Zn produced most stable nanoparticles of smallest average size, nanoparticles produced with higher content of either of the component elements are unstable, inducing agglomeration and coalescence to form elongated structures with uneven morphologies. Au3Zn1 nanoparticles followed a directional growth pattern, producing bimetallic nanorods with multiple crystalline domains. Interestingly, in these rod-like nanostructures, the domains are in well array of solid solution-like bimetallic and pure mono-metallic regions alternatively. Such nanostructures with uneven morphology and compositions might show distinct catalytic selectivity in chemical reactions.

MoMaS reactive transport benchmark using PFLOTRAN

NASA Astrophysics Data System (ADS)

Park, H.

2017-12-01

MoMaS benchmark was developed to enhance numerical simulation capability for reactive transport modeling in porous media. The benchmark was published in late September of 2009; it is not taken from a real chemical system, but realistic and numerically challenging tests. PFLOTRAN is a state-of-art massively parallel subsurface flow and reactive transport code that is being used in multiple nuclear waste repository projects at Sandia National Laboratories including Waste Isolation Pilot Plant and Used Fuel Disposition. MoMaS benchmark has three independent tests with easy, medium, and hard chemical complexity. This paper demonstrates how PFLOTRAN is applied to this benchmark exercise and shows results of the easy benchmark test case which includes mixing of aqueous components and surface complexation. Surface complexations consist of monodentate and bidentate reactions which introduces difficulty in defining selectivity coefficient if the reaction applies to a bulk reference volume. The selectivity coefficient becomes porosity dependent for bidentate reaction in heterogeneous porous media. The benchmark is solved by PFLOTRAN with minimal modification to address the issue and unit conversions were made properly to suit PFLOTRAN.

ChEBI in 2016: Improved services and an expanding collection of metabolites

PubMed Central

Hastings, Janna; Owen, Gareth; Dekker, Adriano; Ennis, Marcus; Kale, Namrata; Muthukrishnan, Venkatesh; Turner, Steve; Swainston, Neil; Mendes, Pedro; Steinbeck, Christoph

2016-01-01

ChEBI is a database and ontology containing information about chemical entities of biological interest. It currently includes over 46 000 entries, each of which is classified within the ontology and assigned multiple annotations including (where relevant) a chemical structure, database cross-references, synonyms and literature citations. All content is freely available and can be accessed online at http://www.ebi.ac.uk/chebi. In this update paper, we describe recent improvements and additions to the ChEBI offering. We have substantially extended our collection of endogenous metabolites for several organisms including human, mouse, Escherichia coli and yeast. Our front-end has also been reworked and updated, improving the user experience, removing our dependency on Java applets in favour of embedded JavaScript components and moving from a monthly release update to a ‘live’ website. Programmatic access has been improved by the introduction of a library, libChEBI, in Java, Python and Matlab. Furthermore, we have added two new tools, namely an analysis tool, BiNChE, and a query tool for the ontology, OntoQuery. PMID:26467479

Influence of ingredients and chemical components on the quality of Chinese steamed bread.

PubMed

Zhu, Fan

2014-11-15

Chinese steamed bread (CSB) is a staple food in China since ancient time. The basic ingredients include wheat flour, yeast/sourdough, and water. Current consumer trends urge the production of CSB on a large scale as well as the formulation of healthier CSB with specific nutritional benefits. This requires a better definition of the relationship between the properties of ingredients/chemical components and CSB quality. This review summarises the recent advances in understanding the roles of basic and optional ingredients and their chemical components in the appearance, textural, sensory, and shelf-life properties of CSB, and provides suggestions for further research to match the current trends. Copyright © 2014 Elsevier Ltd. All rights reserved.

Exploring the Use of Multiple Analogical Models when Teaching and Learning Chemical Equilibrium

ERIC Educational Resources Information Center

Harrison, Allan G.; De Jong, Onno

2005-01-01

This study describes the multiple analogical models used to introduce and teach Grade 12 chemical equilibrium. We examine the teacher's reasons for using models, explain each model's development during the lessons, and analyze the understandings students derived from the models. A case study approach was used and the data were drawn from the…

Concepts, Methods, and Data Sources for Cumulative Health Risk Assessment of Multiple Chemicals, Exposures and Effects: A Resource Document (Final Report, 2008)

EPA Science Inventory

EPA announced the availability of the final report, Concepts, Methods, and Data Sources for Cumulative Health Risk Assessment of Multiple Chemicals, Exposures and Effects: A Resource Document. This report provides the concepts, methods and data sources needed to assist in...

Use of external cavity quantum cascade laser compliance voltage in real-time trace gas sensing of multiple chemicals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillips, Mark C.; Taubman, Matthew S.; Kriesel, Jason M.

2015-02-08

We describe a prototype trace gas sensor designed for real-time detection of multiple chemicals. The sensor uses an external cavity quantum cascade laser (ECQCL) swept over its tuning range of 940-1075 cm-1 (9.30-10.7 µm) at a 10 Hz repetition rate.

Sex-specific trail pheromone mediates complex mate finding behavior in Anoplophora glabripennis.

PubMed

Hoover, Kelli; Keena, Melody; Nehme, Maya; Wang, Shifa; Meng, Peter; Zhang, Aijun

2014-02-01

Anoplophora glabripennis (Motsch.) is a polyphagous member of the Cerambycidae, and is considered, worldwide, to be one of the most serious quarantine pests of deciduous trees. We isolated four chemicals from the trail of A. glabripennis virgin and mated females that were not present in trails of mature males. These compounds were identified as 2-methyldocosane and (Z)-9-tricosene (major components), as well as (Z)-9-pentacosene and (Z)-7-pentacosene (minor components); every trail wash sample contained all four chemical components, although the amounts and ratios changed with age of the female. Males responded to the full pheromone blend, regardless of mating status, but virgin females chose the control over the pheromone, suggesting that they may use it as a spacing pheromone to avoid intraspecific competition and maximize resources. Virgin, but not mated, males also chose the major pheromone components in the absence of the minor components, over the control. Taken together, these results indicate that all four chemicals are components of the trail pheromone. The timing of production of the ratios of the pheromone blend components that produced positive responses from males coincided with the timing of sexual maturation of the female.

2D-3D MIGRATION AND CONFORMATIONAL MULTIPLICATION OF CHEMICALS IN LARGE CHEMICAL INVENTORIES

EPA Science Inventory

Chemical interactions are three-dimensional (3D) in nature and require modeling chemicals as 3D entities. In turn, using 3D models of chemicals leads to the realization that a single 2D structure can have hundreds of different conformations, and the electronic properties of these...

Modeling Joint Exposures and Health Outcomes for Cumulative Risk Assessment: the Case of Radon and Smoking

EPA Science Inventory

Community-based cumulative risk assessment requires characterization of exposures to multiple chemical and non-chemical stressors, with consideration of how the non-chemical stressors may influence risks from chemical stressors. Residential radon provides an interesting case exam...

Investigating High School Students' Understanding of Chemical Equilibrium Concepts

ERIC Educational Resources Information Center

Karpudewan, Mageswary; Treagust, David F.; Mocerino, Mauro; Won, Mihye; Chandrasegaran, A. L.

2015-01-01

This study investigated the year 12 students' (N = 56) understanding of chemical equilibrium concepts after instruction using two conceptual tests, the "Chemical Equilibrium Conceptual Test 1" ("CECT-1") consisting of nine two-tier multiple-choice items and the "Chemical Equilibrium Conceptual Test 2"…

Improved ultra-performance liquid chromatography with electrospray ionization quadrupole-time-of-flight high-definition mass spectrometry method for the rapid analysis of the chemical constituents of a typical medical formula: Liuwei Dihuang Wan.

PubMed

Wang, Ping; Lv, Hai tao; Zhang, Ai hua; Sun, Hui; Yan, Guang li; Han, Ying; Wu, Xiu hong; Wang, Xi jun

2013-11-01

Liuwei Dihuang Wan (LDW), a classic Chinese medicinal formula, has been used to improve or restore declined functions related to aging and geriatric diseases, such as impaired mobility, vision, hearing, cognition, and memory. It has attracted increasing attention as one of the most popular and valuable herbal medicines. However, the systematic analysis of the chemical constituents of LDW is difficult and thus has not been well established. In this paper, a rapid, sensitive, and reliable ultra-performance LC with ESI quadrupole TOF high-definition MS method with automated MetaboLynx analysis in positive and negative ion mode was established to characterize the chemical constituents of LDW. The analysis was performed on a Waters UPLC™ HSS T3 using a gradient elution system. MS/MS fragmentation behavior was proposed for aiding the structural identification of the components. Under the optimized conditions, a total of 50 peaks were tentatively characterized by comparing the retention time and MS data. It is concluded that a rapid and robust platform based on ultra-performance LC with ESI quadrupole TOF high-definition MS has been successfully developed for globally identifying multiple constituents of traditional Chinese medicine prescriptions. This is the first report on the systematic analysis of the chemical constituents of LDW. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical dispersants enhance the activity of oil- and gas condensate-degrading marine bacteria.

PubMed

Tremblay, Julien; Yergeau, Etienne; Fortin, Nathalie; Cobanli, Susan; Elias, Miria; King, Thomas L; Lee, Kenneth; Greer, Charles W

2017-12-01

Application of chemical dispersants to oil spills in the marine environment is a common practice to disperse oil into the water column and stimulate oil biodegradation by increasing its bioavailability to indigenous bacteria capable of naturally metabolizing hydrocarbons. In the context of a spill event, the biodegradation of crude oil and gas condensate off eastern Canada is an essential component of a response strategy. In laboratory experiments, we simulated conditions similar to an oil spill with and without the addition of chemical dispersant under both winter and summer conditions and evaluated the natural attenuation potential for hydrocarbons in near-surface sea water from the vicinity of crude oil and natural gas production facilities off eastern Canada. Chemical analyses were performed to determine hydrocarbon degradation rates, and metagenome binning combined with metatranscriptomics was used to reconstruct abundant bacterial genomes and estimate their oil degradation gene abundance and activity. Our results show important and rapid structural shifts in microbial populations in all three different oil production sites examined following exposure to oil, oil with dispersant and dispersant alone. We found that the addition of dispersant to crude oil enhanced oil degradation rates and favored the abundance and expression of oil-degrading genes from a Thalassolituus sp. (that is, metagenome bin) that harbors multiple alkane hydroxylase (alkB) gene copies. We propose that this member of the Oceanospirillales group would be an important oil degrader when oil spills are treated with dispersant.

Chemical, Biological, and Explosive Sensors for Field Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kevin Kyle, Manuel Manard, Stephan Weeks

Special Technologies Laboratory (STL) is developing handheld chemical, biological, and explosive (CBE) detection systems and sensor motes for wireless networked field operations. The CBE sensors are capable of detecting and identifying multiple targeted toxic industrial chemicals (TICs) and high-explosive vapor components. The CBE devices are based on differential mobility spectrometry (DMS) coupled with fast gas chromatography (GC) or mass spectrometry. The systems all include the concepts of: 1. Direct air/particulate “smart” sampling 2. Selective, continuous real-time (~1 sec) alert monitoring using DMS 3. Highly selective, rapid dual technology separation/verification analysis The biosensor technology is based on Raman aerosol particle flowmore » cytometry for target detection and identification. Monitoring and identifying trace level chemical vapors directly from ambient air will allow First Responders to quickly adapt situational response strategies and personal protective equipment needs to the specific response scenario being encountered. First Responders require great confidence in the measurements and ability of a given system to detect CBE below threshold levels without interferences. The concept of determining the background matrix in near real-time to allow subsequent automated field-programmable method selection and cueing of high-value assets in a wide range of environs will be presented. This provides CBE information for decisions prior to First Responders entering the response site or sending a portable mobile unit for a remote site survey of the hazards. The focus is on real-time information needed by those responsible for emergency response and national security.« less

Chemical Composition Analysis of Extracts from Ficus Hirta Using Supercritical Fluid

NASA Astrophysics Data System (ADS)

Deng, S. B.; Chen, J. P.; Chen, Y. Z.; Yu, C. Q.; Yang, Y.; Wu, S. H.; Chen, C. Z.

2018-05-01

Ficus hirta was extracted by supercritical carbon dioxide. The volatile chemical components of extracts were analyzed using gas chromatography-mass spectrometry (GC-MS). The percentage of products extracted by Supercritical Fluid Extraction(SFE) was 2.5%. Nineteen volatile compounds were identified. The main volatile components were Elemicin, Psoralen, Palmitic acid, Bergapten, α-Linolenic acid, Medicarpin, Retinoic Acid, Maackiain, and Squalene. The method is simple and quick, and can be used for the preliminary analysis of chemical constituents of supercritical extracts of Ficus hirta.

Water quality effects of seepage from earthen dams

USGS Publications Warehouse

Yost, C.; Naney, J.W.

1974-01-01

Analyses of surface and seepage waters from selected floodwater retarding structures in west-central Oklahoma, U.S.A. show the salinity of seepage to be several times greater than that of the impounded waters. The increases in concentration of the several chemical components are not proportional. This phenomenon appears to be caused largely by simple solution, which is closely related to the chemical character of the geologic formation that provides the reservoir site and the earth fill of the dam. Concentration of certain chemical components in the seepage water progressively decreases as the structure ages. This is probably a function of depletion, which is related to the amounts and solubility of the parent materials subjected to solution. In contrast, the concentration of certain other components, such as iron and calcium, increases with time. The chemical activities within the accumulating mud on the bottom of the reservoir apparently cause these increases. ?? 1974.

Mass production of chemicals from biomass-derived oil by directly atmospheric distillation coupled with co-pyrolysis

NASA Astrophysics Data System (ADS)

Zhang, Xue-Song; Yang, Guang-Xi; Jiang, Hong; Liu, Wu-Jun; Ding, Hong-Sheng

2013-01-01

Production of renewable commodity chemicals from bio-oil derived from fast pyrolysis of biomass has received considerable interests, but hindered by the presence of innumerable components in bio-oil. In present work, we proposed and experimentally demonstrated an innovative approach combining atmospheric distillation of bio-oil with co-pyrolysis for mass production of renewable chemicals from biomass, in which no waste was produced. It was estimated that 51.86 wt.% of distillate just containing dozens of separable organic components could be recovered using this approach. Ten protogenetic and three epigenetic compounds in distillate were qualitatively identified by gas chromatography/mass spectrometry and quantified by gas chromatography. Among them, the recovery efficiencies of acetic acid, propanoic acid, and furfural were all higher than 80 wt.%. Formation pathways of the distillate components in this process were explored. This work opens up a fascinating prospect for mass production of chemical feedstock from waste biomass.

Chemical structure of the Chromophoric Dissolved Organic Matter (CDOM) fluorescent matter.

NASA Astrophysics Data System (ADS)

Blough, N. V.; Del Vecchio, R.; Cartisano, C. M.; Bianca, M.

2017-12-01

The structure(s), distribution and dynamics of CDOM have been investigated over the last several decades largely through optical spectroscopy (including both absorption and fluorescence) due to the fairly inexpensive instrumentation and the easy-to-gather data (over thousands published papers from 1990-2016). Yet, the chemical structure(s) of the light absorbing and emitting species or constituents within CDOM has only recently being proposed and tested through chemical manipulation of selected functional groups (such as carbonyl and carboxylic/phenolic containing molecules) naturally occurring within the organic matter pool. Similarly, fitting models (among which the PArallel FACtor analysis, PARAFAC) have been developed to better understand the nature of a subset of DOM, the CDOM fluorescent matter (FDOM). Fluorescence spectroscopy coupled with chemical tests and PARAFAC analyses could potentially provide valuable insights on CDOM sources and chemical nature of the FDOM pool. However, despite that applications (and publications) of PARAFAC model to FDOM have grown exponentially since its first application/publication (2003), a large fraction of such publications has misinterpreted the chemical meaning of the delivered PARAFAC `components' leading to more confusion than clarification on the nature, distribution and dynamics of the FDOM pool. In this context, we employed chemical manipulation of selected functional groups to gain further insights on the chemical structure of the FDOM and we tested to what extent the PARAFAC `components' represent true fluorophores through a controlled chemical approach with the ultimate goal to provide insights on the chemical nature of such `components' (as well as on the chemical nature of the FDOM) along with the advantages and limitations of the PARAFAC application.

Identification of molecular markers associated with mite resistance in coconut (Cocos nucifera L.).

PubMed

Shalini, K V; Manjunatha, S; Lebrun, P; Berger, A; Baudouin, L; Pirany, N; Ranganath, R M; Prasad, D Theertha

2007-01-01

Coconut mite (Aceria guerreronis 'Keifer') has become a major threat to Indian coconut (Coçcos nucifera L.) cultivators and the processing industry. Chemical and biological control measures have proved to be costly, ineffective, and ecologically undesirable. Planting mite-resistant coconut cultivars is the most effective method of preventing yield loss and should form a major component of any integrated pest management stratagem. Coconut genotypes, and mite-resistant and -susceptible accessions were collected from different parts of South India. Thirty-two simple sequence repeat (SSR) and 7 RAPD primers were used for molecular analyses. In single-marker analysis, 9 SSR and 4 RAPD markers associated with mite resistance were identified. In stepwise multiple regression analysis of SSRs, a combination of 6 markers showed 100% association with mite infestation. Stepwise multiple regression analysis for RAPD data revealed that a combination of 3 markers accounted for 83.86% of mite resistance in the selected materials. Combined stepwise multiple regression analysis of RAPD and SSR data showed that a combination of 5 markers explained 100% of the association with mite resistance in coconut. Markers associated with mite resistance are important in coconut breeding programs and will facilitate the selection of mite-resistant plants at an early stage as well as mother plants for breeding programs.

Extended Pausing by Humans on Multiple Fixed-Ratio Schedules with Varied Reinforcer Magnitude and Response Requirements

ERIC Educational Resources Information Center

Williams, Dean C.; Saunders, Kathryn J.; Perone, Michael

2011-01-01

We conducted three experiments to reproduce and extend Perone and Courtney's (1992) study of pausing at the beginning of fixed-ratio schedules. In a multiple schedule with unequal amounts of food across two components, they found that pigeons paused longest in the component associated with the smaller amount of food (the lean component), but only…

Effectiveness-weighted control method for a cooling system

DOEpatents

Campbell, Levi A.; Chu, Richard C.; David, Milnes P.; Ellsworth Jr., Michael J.; Iyengar, Madhusudan K.; Schmidt, Roger R.; Simons, Robert E.

2015-12-15

Energy efficient control of cooling system cooling of an electronic system is provided based, in part, on weighted cooling effectiveness of the components. The control includes automatically determining speed control settings for multiple adjustable cooling components of the cooling system. The automatically determining is based, at least in part, on weighted cooling effectiveness of the components of the cooling system, and the determining operates to limit power consumption of at least the cooling system, while ensuring that a target temperature associated with at least one of the cooling system or the electronic system is within a desired range by provisioning, based on the weighted cooling effectiveness, a desired target temperature change among the multiple adjustable cooling components of the cooling system. The provisioning includes provisioning applied power to the multiple adjustable cooling components via, at least in part, the determined control settings.

Synthetic wind speed scenarios generation for probabilistic analysis of hybrid energy systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Jun; Rabiti, Cristian

Hybrid energy systems consisting of multiple energy inputs and multiple energy outputs have been proposed to be an effective element to enable ever increasing penetration of clean energy. In order to better understand the dynamic and probabilistic behavior of hybrid energy systems, this paper proposes a model combining Fourier series and autoregressive moving average (ARMA) to characterize historical weather measurements and to generate synthetic weather (e.g., wind speed) data. In particular, Fourier series is used to characterize the seasonal trend in historical data, while ARMA is applied to capture the autocorrelation in residue time series (e.g., measurements minus seasonal trends).more » The generated synthetic wind speed data is then utilized to perform probabilistic analysis of a particular hybrid energy system con guration, which consists of nuclear power plant, wind farm, battery storage, natural gas boiler, and chemical plant. As a result, requirements on component ramping rate, economic and environmental impacts of hybrid energy systems, and the effects of deploying different sizes of batteries in smoothing renewable variability, are all investigated.« less

Synthetic wind speed scenarios generation for probabilistic analysis of hybrid energy systems

DOE PAGES

Chen, Jun; Rabiti, Cristian

2016-11-25

Hybrid energy systems consisting of multiple energy inputs and multiple energy outputs have been proposed to be an effective element to enable ever increasing penetration of clean energy. In order to better understand the dynamic and probabilistic behavior of hybrid energy systems, this paper proposes a model combining Fourier series and autoregressive moving average (ARMA) to characterize historical weather measurements and to generate synthetic weather (e.g., wind speed) data. In particular, Fourier series is used to characterize the seasonal trend in historical data, while ARMA is applied to capture the autocorrelation in residue time series (e.g., measurements minus seasonal trends).more » The generated synthetic wind speed data is then utilized to perform probabilistic analysis of a particular hybrid energy system con guration, which consists of nuclear power plant, wind farm, battery storage, natural gas boiler, and chemical plant. As a result, requirements on component ramping rate, economic and environmental impacts of hybrid energy systems, and the effects of deploying different sizes of batteries in smoothing renewable variability, are all investigated.« less

Initial analyses of the relationship between 'Thresholds' of toxicity for individual chemicals and 'Interaction Thresholds' for chemical mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Raymond S.H.; Dennison, James E.

2007-09-01

The inter-relationship of 'Thresholds' between chemical mixtures and their respective component single chemicals was studied using three sets of data and two types of analyses. Two in vitro data sets involve cytotoxicity in human keratinocytes from treatment of metals and a metal mixture [Bae, D.S., Gennings, C., Carter, Jr., W.H., Yang, R.S.H., Campain, J.A., 2001. Toxicological interactions among arsenic, cadmium, chromium, and lead in human keratinocytes. Toxicol. Sci. 63, 132-142; Gennings, C., Carter, Jr., W.H., Campain, J.A., Bae, D.S., Yang, R.S.H., 2002. Statistical analysis of interactive cytotoxicity in human epidermal keratinocytes following exposure to a mixture of four metals. J.more » Agric. Biol. Environ. Stat. 7, 58-73], and induction of estrogen receptor alpha (ER-{alpha}) reporter gene in MCF-7 human breast cancer cells by estrogenic xenobiotics [Gennings, C., Carter, Jr., W.H., Carney, E.W., Charles, G.D., Gollapudi, B.B., Carchman, R.A., 2004. A novel flexible approach for evaluating fixed ratio mixtures of full and partial agonists. Toxicol. Sci. 80, 134-150]. The third data set came from PBPK modeling of gasoline and its components in the human. For in vitro cellular responses, we employed Benchmark Dose Software (BMDS) to obtain BMD{sub 01}, BMD{sub 05}, and BMD{sub 10}. We then plotted these BMDs against exposure concentrations for the chemical mixture and its components to assess the ranges and slopes of these BMD-concentration lines. In doing so, we consider certain BMDs to be 'Interaction Thresholds' or 'Thresholds' for mixtures and their component single chemicals and the slope of the line must be a reflection of the potency of the biological effects. For in vivo PBPK modeling, we used 0.1x TLVs, TLVs, and 10x TLVs for gasoline and six component markers as input dosing for PBPK modeling. In this case, the venous blood levels under the hypothetical exposure conditions become our designated 'Interaction Thresholds' or 'Thresholds' for gasoline and its component single chemicals. Our analyses revealed that the mixture 'Interaction Thresholds' appear to stay within the bounds of the 'Thresholds' of its respective component single chemicals. Although such a trend appears to be emerging, nevertheless, it should be emphasized that our analyses are based on limited data sets and further analyses on data sets, preferably the more comprehensive experimental data sets, are needed before a definitive conclusion can be drawn.« less

High-throughput dietary exposure predictions for chemical migrants from food contact substances for use in chemical prioritization

EPA Science Inventory

Under the ExpoCast program, United States Environmental Protection Agency (EPA) researchers have developed a high-throughput (HT) framework for estimating aggregate exposures to chemicals from multiple pathways to support rapid prioritization of chemicals. Here, we present method...

Biogeographical Analysis of Chemical Co-Occurrence Data to Identify Priorities for Mixtures Research

EPA Science Inventory

A challenge with multiple chemical risk assessment is the need to consider the joint behavior of chemicals in mixtures. To address this need, pharmacologists and toxicologists have developed methods over the years to evaluate and test chemical interaction. In practice, however, t...

Distribution of trace elements in certain ecological components and animal products in a dairy farm at Tirupati, Chittoor District, Andhra Pradesh, India.

PubMed

Raghu, V

2013-12-01

Biogeochemical characteristics of the cattle are dealt based on the observations made in Ayurveda in the light of modern scientific developments in applied environmental geochemistry. The biogeochemical characteristics of certain important ecological components and animal products of the stall-fed animals were studied. For this purpose, a dairy farm of Tirumala-Tirupati Devasthanams, a religious organization in Tirupati, Chittoor District, Andhra Pradesh was selected. This study is intended to trace out the trace element interactions in the ecological components (soil, water, fodder, feed) of the stall-fed animals and their output components viz. dung, urine and milk. Physical, physico-chemical properties and certain trace elements were determined for composite samples of ecological components and dung, urine, and milk of stall-fed animals. The variations in the distribution of pH and EC of urine and milk reflect the variations in their physico-chemical or hydro-chemical properties. As mentioned in Ayurveda, not only the properties of milk but also the properties of dung and urine reflect their diet and conditions of their habitat. Even though the diet is the same, the cows of different breeds yield milk of variable physical, physico-chemical properties and trace element composition which can be attributed to their body colour, substantiating Ayurveda.

[Spatial distribution characteristics of the physical and chemical properties of water in the Kunes River after the supply of snowmelt during spring].

PubMed

Liu, Xiang; Guo, Ling-Peng; Zhang, Fei-Yun; Ma, Jie; Mu, Shu-Yong; Zhao, Xin; Li, Lan-Hai

2015-02-01

Eight physical and chemical indicators related to water quality were monitored from nineteen sampling sites along the Kunes River at the end of snowmelt season in spring. To investigate the spatial distribution characteristics of water physical and chemical properties, cluster analysis (CA), discriminant analysis (DA) and principal component analysis (PCA) are employed. The result of cluster analysis showed that the Kunes River could be divided into three reaches according to the similarities of water physical and chemical properties among sampling sites, representing the upstream, midstream and downstream of the river, respectively; The result of discriminant analysis demonstrated that the reliability of such a classification was high, and DO, Cl- and BOD5 were the significant indexes leading to this classification; Three principal components were extracted on the basis of the principal component analysis, in which accumulative variance contribution could reach 86.90%. The result of principal component analysis also indicated that water physical and chemical properties were mostly affected by EC, ORP, NO3(-) -N, NH4(+) -N, Cl- and BOD5. The sorted results of principal component scores in each sampling sites showed that the water quality was mainly influenced by DO in upstream, by pH in midstream, and by the rest of indicators in downstream. The order of comprehensive scores for principal components revealed that the water quality degraded from the upstream to downstream, i.e., the upstream had the best water quality, followed by the midstream, while the water quality at downstream was the worst. This result corresponded exactly to the three reaches classified using cluster analysis. Anthropogenic activity and the accumulation of pollutants along the river were probably the main reasons leading to this spatial difference.

Report of the Workshop on Unmixing the SNCs: Chemical, Isotopic, and Petrologic Components of Martian Meteorites

NASA Technical Reports Server (NTRS)

Treiman, Allan H. (Editor); Herd, Christopher D. K. (Editor)

2002-01-01

Geochemical and petrologic studies of the Martian meteorites (nicknamed the SNCs) have proliferated in the past few years, from a wealth of new samples and the perfection of new analytical methods. An intriguing result from these studies is that the chemical and isotopic compositions of the Martian meteorites, all basalts or derived from basaltic magma, can be modeled as mixtures of a limited number of components. These mixing components were the focus of the workshop.

Microfluidic bead-based diodes with targeted circular microchannels for low Reynolds number applications.

PubMed

Sochol, Ryan D; Lu, Albert; Lei, Jonathan; Iwai, Kosuke; Lee, Luke P; Lin, Liwei

2014-05-07

Self-regulating fluidic components are critical to the advancement of microfluidic processors for chemical and biological applications, such as sample preparation on chip, point-of-care molecular diagnostics, and implantable drug delivery devices. Although researchers have developed a wide range of components to enable flow rectification in fluidic systems, engineering microfluidic diodes that function at the low Reynolds number (Re) flows and smaller scales of emerging micro/nanofluidic platforms has remained a considerable challenge. Recently, researchers have demonstrated microfluidic diodes that utilize high numbers of suspended microbeads as dynamic resistive elements; however, using spherical particles to block fluid flow through rectangular microchannels is inherently limited. To overcome this issue, here we present a single-layer microfluidic bead-based diode (18 μm in height) that uses a targeted circular-shaped microchannel for the docking of a single microbead (15 μm in diameter) to rectify fluid flow under low Re conditions. Three-dimensional simulations and experimental results revealed that adjusting the docking channel geometry and size to better match the suspended microbead greatly increased the diodicity (Di) performance. Arraying multiple bead-based diodes in parallel was found to adversely affect system efficacy, while arraying multiple diodes in series was observed to enhance device performance. In particular, systems consisting of four microfluidic bead-based diodes with targeted circular-shaped docking channels in series revealed average Di's ranging from 2.72 ± 0.41 to 10.21 ± 1.53 corresponding to Re varying from 0.1 to 0.6.

Clustering the Orion B giant molecular cloud based on its molecular emission

NASA Astrophysics Data System (ADS)

Bron, Emeric; Daudon, Chloé; Pety, Jérôme; Levrier, François; Gerin, Maryvonne; Gratier, Pierre; Orkisz, Jan H.; Guzman, Viviana; Bardeau, Sébastien; Goicoechea, Javier R.; Liszt, Harvey; Öberg, Karin; Peretto, Nicolas; Sievers, Albrecht; Tremblin, Pascal

2018-02-01

Context. Previous attempts at segmenting molecular line maps of molecular clouds have focused on using position-position-velocity data cubes of a single molecular line to separate the spatial components of the cloud. In contrast, wide field spectral imaging over a large spectral bandwidth in the (sub)mm domain now allows one to combine multiple molecular tracers to understand the different physical and chemical phases that constitute giant molecular clouds (GMCs). Aims: We aim at using multiple tracers (sensitive to different physical processes and conditions) to segment a molecular cloud into physically/chemically similar regions (rather than spatially connected components), thus disentangling the different physical/chemical phases present in the cloud. Methods: We use a machine learning clustering method, namely the Meanshift algorithm, to cluster pixels with similar molecular emission, ignoring spatial information. Clusters are defined around each maximum of the multidimensional probability density function (PDF) of the line integrated intensities. Simple radiative transfer models were used to interpret the astrophysical information uncovered by the clustering analysis. Results: A clustering analysis based only on the J = 1-0 lines of three isotopologues of CO proves sufficient to reveal distinct density/column density regimes (nH 100 cm-3, 500 cm-3, and >1000 cm-3), closely related to the usual definitions of diffuse, translucent and high-column-density regions. Adding two UV-sensitive tracers, the J = 1-0 line of HCO+ and the N = 1-0 line of CN, allows us to distinguish two clearly distinct chemical regimes, characteristic of UV-illuminated and UV-shielded gas. The UV-illuminated regime shows overbright HCO+ and CN emission, which we relate to a photochemical enrichment effect. We also find a tail of high CN/HCO+ intensity ratio in UV-illuminated regions. Finer distinctions in density classes (nH 7 × 103 cm-3, 4 × 104 cm-3) for the densest regions are also identified, likely related to the higher critical density of the CN and HCO+ (1-0) lines. These distinctions are only possible because the high-density regions are spatially resolved. Conclusions: Molecules are versatile tracers of GMCs because their line intensities bear the signature of the physics and chemistry at play in the gas. The association of simultaneous multi-line, wide-field mapping and powerful machine learning methods such as the Meanshift clustering algorithm reveals how to decode the complex information available in these molecular tracers. Data products associated with this paper are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/A12 and at http://www.iram.fr/ pety/ORION-B

16 CFR 1109.1 - Scope.

Code of Federal Regulations, 2012 CFR

2012-01-01

...) Component part manufacturers and suppliers may certify or test their component parts, but are not required... for component part testing of chemical content. Subpart C describes the conditions and requirements...

16 CFR 1109.1 - Scope.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) Component part manufacturers and suppliers may certify or test their component parts, but are not required... for component part testing of chemical content. Subpart C describes the conditions and requirements...

"Helpful People in Touch" Consumer Led Self Help Programs for People with Multiple Disorders, Mental Illness, Drug Addiction, and Alcoholism (MIDAA).

ERIC Educational Resources Information Center

Sciacca, Kathleen

This paper describes the consumer program, "Helpful People in Touch," a self-help treatment program for people with the multiple disorders of mental illness, drug addiction, and/or alcoholism. First, the terms, "Mentally Ill Chemical Abusers and Addicted" (MICAA) and "Chemical Abusing Mentally Ill" (CAMI) are defined…

Biochemometrics for Natural Products Research: Comparison of Data Analysis Approaches and Application to Identification of Bioactive Compounds.

PubMed

Kellogg, Joshua J; Todd, Daniel A; Egan, Joseph M; Raja, Huzefa A; Oberlies, Nicholas H; Kvalheim, Olav M; Cech, Nadja B

2016-02-26

A central challenge of natural products research is assigning bioactive compounds from complex mixtures. The gold standard approach to address this challenge, bioassay-guided fractionation, is often biased toward abundant, rather than bioactive, mixture components. This study evaluated the combination of bioassay-guided fractionation with untargeted metabolite profiling to improve active component identification early in the fractionation process. Key to this methodology was statistical modeling of the integrated biological and chemical data sets (biochemometric analysis). Three data analysis approaches for biochemometric analysis were compared, namely, partial least-squares loading vectors, S-plots, and the selectivity ratio. Extracts from the endophytic fungi Alternaria sp. and Pyrenochaeta sp. with antimicrobial activity against Staphylococcus aureus served as test cases. Biochemometric analysis incorporating the selectivity ratio performed best in identifying bioactive ions from these extracts early in the fractionation process, yielding altersetin (3, MIC 0.23 μg/mL) and macrosphelide A (4, MIC 75 μg/mL) as antibacterial constituents from Alternaria sp. and Pyrenochaeta sp., respectively. This study demonstrates the potential of biochemometrics coupled with bioassay-guided fractionation to identify bioactive mixture components. A benefit of this approach is the ability to integrate multiple stages of fractionation and bioassay data into a single analysis.

Clay Minerals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mueller, Karl T.; Sanders, Rebecca L.; Washton, Nancy M.

2014-03-14

Clay minerals are important components of the environment and are involved or implicated in processes such as the uptake of pollutants and the release of nutrients and as potential platforms for a number of chemical reactions. Owing to their small particle sizes (typically, on the order of microns or smaller) and mixing with a variety of other minerals and soil components, advanced characterization methods are needed to study their structures, dynamics, and reactivities. In this article, we describe the use of solid-state NMR methods to characterize the structures and chemistries of clay minerals. Early one-pulse magic-angle spinning (MAS) NMR studiesmore » of 27Al and 29Si have now been enhanced and extended with new studies utilizing advanced methodologies (such as Multiple Quantum MAS) as well as studies of less-sensitive nuclei. In additional work, the issue of reactivity of clay minerals has been addressed, including studies of reactive surface area in the environment. Utilizations of NMR-sensitive nuclides within the clay minerals themselves, and in molecules that react with specific sites on the clay mineral surfaces, have aided in understanding the reactivity of these complex aluminosilicate systems.« less

Using foreground/background analysis to determine leaf and canopy chemistry

NASA Technical Reports Server (NTRS)

Pinzon, J. E.; Ustin, S. L.; Hart, Q. J.; Jacquemoud, S.; Smith, M. O.

1995-01-01

Spectral Mixture Analysis (SMA) has become a well established procedure for analyzing imaging spectrometry data, however, the technique is relatively insensitive to minor sources of spectral variation (e.g., discriminating stressed from unstressed vegetation and variations in canopy chemistry). Other statistical approaches have been tried e.g., stepwise multiple linear regression analysis to predict canopy chemistry. Grossman et al. reported that SMLR is sensitive to measurement error and that the prediction of minor chemical components are not independent of patterns observed in more dominant spectral components like water. Further, they observed that the relationships were strongly dependent on the mode of expressing reflectance (R, -log R) and whether chemistry was expressed on a weight (g/g) or are basis (g/sq m). Thus, alternative multivariate techniques need to be examined. Smith et al. reported a revised SMA that they termed Foreground/Background Analysis (FBA) that permits directing the analysis along any axis of variance by identifying vectors through the n-dimensional spectral volume orthonormal to each other. Here, we report an application of the FBA technique for the detection of canopy chemistry using a modified form of the analysis.

Phase-Change Thermoplastic Elastomer Blends for Tunable Shape Memory by Physical Design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mineart, Kenneth P.; Tallury, Syamal S.; Li, Tao

Shape-memory polymers (SMPs) change shape upon exposure to an environmental stimulus.1-3 They are of considerable importance in the ongoing development of stimuli-responsive biomedical4,5 and deployable6 devices, and their function depends on the presence of two components.7 The first provides mechanical rigidity to ensure retention of one or more temporary strain states and also serves as a switch capable of releasing a temporary strain state. The second, a network-forming component, is required to restore the polymer to a prior strain state upon stimulation. In thermally-activated SMPs, the switching element typically relies on a melting or glass transition temperature,1-3,7 and broad ormore » multiple switches permit several temporary strain states.8-10 Chemical integration of network-forming and switching species endows SMPs with specific properties.8,10,11 Here, we demonstrate that phase-change materials incorporated into network-forming macromolecules yield shape-memory polymer blends (SMPBs) with physically tunable switching temperatures and recovery kinetics for use in multi-responsive laminates and shape-change electronics.« less

A novel strategy with standardized reference extract qualification and single compound quantitative evaluation for quality control of Panax notoginseng used as a functional food.

PubMed

Li, S P; Qiao, C F; Chen, Y W; Zhao, J; Cui, X M; Zhang, Q W; Liu, X M; Hu, D J

2013-10-25

Root of Panax notoginseng (Burk.) F.H. Chen (Sanqi in Chinese) is one of traditional Chinese medicines (TCMs) based functional food. Saponins are the major bioactive components. The shortage of reference compounds or chemical standards is one of the main bottlenecks for quality control of TCMs. A novel strategy, i.e. standardized reference extract based qualification and single calibrated components directly quantitative estimation of multiple analytes, was proposed to easily and effectively control the quality of natural functional foods such as Sanqi. The feasibility and credibility of this methodology were also assessed with a developed fast HPLC method. Five saponins, including ginsenoside Rg1, Re, Rb1, Rd and notoginsenoside R1 were rapidly separated using a conventional HPLC in 20 min. The quantification method was also compared with individual calibration curve method. The strategy is feasible and credible, which is easily and effectively adapted for improving the quality control of natural functional foods such as Sanqi. Copyright © 2013 Elsevier B.V. All rights reserved.

Screening and Identification of the Metabolites in Rat Plasma and Urine after Oral Administration of Areca catechu L. Nut Extract by Ultra-High-Pressure Liquid Chromatography Coupled with Linear Ion Trap-Orbitrap Tandem Mass Spectrometry.

PubMed

Li, Lulu; Luo, Zhiqiang; Liu, Yang; Wang, Hao; Liu, Aoxue; Yu, Guohua; Li, Mengwei; Yang, Ruirui; Chen, Xinjing; Zhu, Jialian; Zhao, Baosheng

2017-06-21

Areca catechu L. nut, a well-known toxic traditional herbal medicine, has been widely used to treat various diseases in China and many other Asian countries for centuries. However, to date the in vivo absorption and metabolism of its multiple bioactive or toxic components still remain unclear. In this study, liquid chromatography coupled with tandem mass spectrometry was used to analyze the major components and their metabolites in rat plasma and urine after oral administration of Areca catechu L. nut extract (ACNE). A total of 12 compounds, including 6 alkaloids, 3 tannins and 3 amino acids, were confirmed or tentatively identified from ACNE. In vivo, 40 constituents, including 8 prototypes and 32 metabolites were identified in rat plasma and urine samples. In summary, this study showed an insight into the metabolism of ACNE in vivo, which may provide helpful chemical information for better understanding of the toxicological and pharmacological profiles of ACNE.

Independent component model for cognitive functions of multiple subjects using [15O]H2O PET images.

PubMed

Park, Hae-Jeong; Kim, Jae-Jin; Youn, Tak; Lee, Dong Soo; Lee, Myung Chul; Kwon, Jun Soo

2003-04-01

An independent component model of multiple subjects' positron emission tomography (PET) images is proposed to explore the overall functional components involved in a task and to explain subject specific variations of metabolic activities under altered experimental conditions utilizing the Independent component analysis (ICA) concept. As PET images represent time-compressed activities of several cognitive components, we derived a mathematical model to decompose functional components from cross-sectional images based on two fundamental hypotheses: (1) all subjects share basic functional components that are common to subjects and spatially independent of each other in relation to the given experimental task, and (2) all subjects share common functional components throughout tasks which are also spatially independent. The variations of hemodynamic activities according to subjects or tasks can be explained by the variations in the usage weight of the functional components. We investigated the plausibility of the model using serial cognitive experiments of simple object perception, object recognition, two-back working memory, and divided attention of a syntactic process. We found that the independent component model satisfactorily explained the functional components involved in the task and discuss here the application of ICA in multiple subjects' PET images to explore the functional association of brain activations. Copyright 2003 Wiley-Liss, Inc.

Contact-free heart rate measurement using multiple video data

NASA Astrophysics Data System (ADS)

Hung, Pang-Chan; Lee, Kual-Zheng; Tsai, Luo-Wei

2013-10-01

In this paper, we propose a contact-free heart rate measurement method by analyzing sequential images of multiple video data. In the proposed method, skin-like pixels are firstly detected from multiple video data for extracting the color features. These color features are synchronized and analyzed by independent component analysis. A representative component is finally selected among these independent component candidates to measure the HR, which achieves under 2% deviation on average compared with a pulse oximeter in the controllable environment. The advantages of the proposed method include: 1) it uses low cost and high accessibility camera device; 2) it eases users' discomfort by utilizing contact-free measurement; and 3) it achieves the low error rate and the high stability by integrating multiple video data.

Effects of conditioned reinforcement frequency in an intermittent free-feeding situation, 12

PubMed Central

Zimmerman, Joseph; Hanford, Peter V.; Brown, Wyman

1967-01-01

Key-pecking intermittently produced a set of brief exteroceptive stimulus changes under two-component multiple schedules of conditioned reinforcement. Throughout the study, free access to grain was concurrently provided on an intermittent basis via a variable-interval tape. Free food presentations scheduled by the tape were delivered if no peck had been emitted for 6 sec, and the brief stimulus changes produced by responding under the multiple schedules were those which accompanied food presentation. The second component of each multiple schedule was always associated with a 1-min, variable-interval schedule of conditioned reinforcement. The schedule associated with the first component was systematically varied and conditioned reinforcement was either absent (extinction) or programmed on a 1-, 3-, 6-, or 12-min variable-interval schedule. Under these conditions, rate of responding in the manipulated component decreased monotonically with a decrease in the frequency of conditioned reinforcement. In addition, contrast effects were often obtained in the constant, second component. These results are similar to those obtained with similar multiple schedules of primary reinforcement. PMID:6033554

Evidence for positive, but not negative, behavioral contrast with wheel-running reinforcement on multiple variable-ratio schedules.

PubMed

Belke, Terry W; Pierce, W David

2016-12-01

Rats responded on a multiple variable-ratio (VR) 10 VR 10 schedule of reinforcement in which lever pressing was reinforced by the opportunity to run in a wheel for 30s in both the changed (manipulated) and unchanged components. To generate positive contrast, the schedule of reinforcement in the changed component was shifted to extinction; to generate negative contrast, the schedule was shifted to VR 3. With the shift to extinction in the changed component, wheel-running and local lever-pressing rates increased in the unchanged component, a result supporting positive contrast; however, the shift to a VR 3 schedule in the changed component showed no evidence of negative contrast in the unaltered setting, only wheel running decreased in the unchanged component. Changes in wheel-running rates across components were consistent in showing a compensation effect, depending on whether the schedule manipulation increased or decreased opportunities for wheel running in the changed component. These findings are the first to demonstrate positive behavioral contrast on a multiple schedule with wheel running as reinforcement in both components. Copyright © 2016 Elsevier B.V. All rights reserved.

Final Technical Report - Center for Technology for Advanced Scientific Component Software (TASCS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sussman, Alan

2014-10-21

This is a final technical report for the University of Maryland work in the SciDAC Center for Technology for Advanced Scientific Component Software (TASCS). The Maryland work focused on software tools for coupling parallel software components built using the Common Component Architecture (CCA) APIs. Those tools are based on the Maryland InterComm software framework that has been used in multiple computational science applications to build large-scale simulations of complex physical systems that employ multiple separately developed codes.

16 CFR § 1109.1 - Scope.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) Component part manufacturers and suppliers may certify or test their component parts, but are not required... for component part testing of chemical content. Subpart C describes the conditions and requirements...

Effect of anatomical characteristics and chemical components on microwave-assisted liquefaction of bamboo wastes

Treesearch

JiuLong Xie; XingYan Huang; JinQiu Qi; Chung Hse; Todd Shupe

2014-01-01

The epidermis layer waste (ELW) and the inner layer waste (ILW) were removed from Phyllostachys pubescens bamboo, and the anatomical characteristics and chemical components of these wastes were comparatively investigated. Both the ELW and the ILW were subjected to a microwave-assisted liquefaction process to evaluate the relationship between bamboo...

30 CFR 75.1101-22 - Inspection of dry powder chemical systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inspection of dry powder chemical systems. 75...-22 Inspection of dry powder chemical systems. (a) Each dry powder chemical system shall be examined... the dry powder chemical system has been actuated, all components of the system shall be cleaned...

30 CFR 75.1101-22 - Inspection of dry powder chemical systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Inspection of dry powder chemical systems. 75...-22 Inspection of dry powder chemical systems. (a) Each dry powder chemical system shall be examined... the dry powder chemical system has been actuated, all components of the system shall be cleaned...

30 CFR 75.1101-22 - Inspection of dry powder chemical systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Inspection of dry powder chemical systems. 75...-22 Inspection of dry powder chemical systems. (a) Each dry powder chemical system shall be examined... the dry powder chemical system has been actuated, all components of the system shall be cleaned...

30 CFR 75.1101-22 - Inspection of dry powder chemical systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Inspection of dry powder chemical systems. 75...-22 Inspection of dry powder chemical systems. (a) Each dry powder chemical system shall be examined... the dry powder chemical system has been actuated, all components of the system shall be cleaned...

30 CFR 75.1101-14 - Installation of dry powder chemical systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

...' Laboratories, Inc., or Factory Mutual Engineering Corp. (c) The components of each dry powder chemical system... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Installation of dry powder chemical systems. 75...-14 Installation of dry powder chemical systems. (a) Self-contained dry powder chemical systems shall...

30 CFR 75.1101-14 - Installation of dry powder chemical systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

...' Laboratories, Inc., or Factory Mutual Engineering Corp. (c) The components of each dry powder chemical system... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Installation of dry powder chemical systems. 75...-14 Installation of dry powder chemical systems. (a) Self-contained dry powder chemical systems shall...

30 CFR 75.1101-14 - Installation of dry powder chemical systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

...' Laboratories, Inc., or Factory Mutual Engineering Corp. (c) The components of each dry powder chemical system... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Installation of dry powder chemical systems. 75...-14 Installation of dry powder chemical systems. (a) Self-contained dry powder chemical systems shall...

30 CFR 75.1101-14 - Installation of dry powder chemical systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

...' Laboratories, Inc., or Factory Mutual Engineering Corp. (c) The components of each dry powder chemical system... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Installation of dry powder chemical systems. 75...-14 Installation of dry powder chemical systems. (a) Self-contained dry powder chemical systems shall...

30 CFR 75.1101-14 - Installation of dry powder chemical systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

...' Laboratories, Inc., or Factory Mutual Engineering Corp. (c) The components of each dry powder chemical system... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Installation of dry powder chemical systems. 75...-14 Installation of dry powder chemical systems. (a) Self-contained dry powder chemical systems shall...

Richard T. (Rick) Elander | NREL

Science.gov Websites

T. (Rick) Elander Photo of Rick Elander Richard Elander Researcher VI-Chemical Engineering Chemicals and AIChE Annual Meeting, multiple years Education M.S., Chemical Engineering (Biochemical Engineering), Colorado State University B.S., Chemical Engineering, University of Pennsylvania Professional

Development of a Raman chemical imaging detection method for authenticating skim milk powder

USDA-ARS?s Scientific Manuscript database

This research demonstrated that Raman chemical imaging coupled with a simple image classification algorithm can be used to detect multiple chemical adulterants in skim milk powder. Ammonium sulfate, dicyandiamide, melamine, and urea were mixed into the milk powder as chemical adulterants in the conc...

Testing the Hypothesis of Biofilm as a Source for Soft Tissue and Cell-Like Structures Preserved in Dinosaur Bone

PubMed Central

2016-01-01

Recovery of still-soft tissue structures, including blood vessels and osteocytes, from dinosaur bone after demineralization was reported in 2005 and in subsequent publications. Despite multiple lines of evidence supporting an endogenous source, it was proposed that these structures arose from contamination from biofilm-forming organisms. To test the hypothesis that soft tissue structures result from microbial invasion of the fossil bone, we used two different biofilm-forming microorganisms to inoculate modern bone fragments from which organic components had been removed. We show fundamental morphological, chemical and textural differences between the resultant biofilm structures and those derived from dinosaur bone. The data do not support the hypothesis that biofilm-forming microorganisms are the source of these structures. PMID:26926069

Improved Hypoxia Modeling for Nutrient Control Decisions in the Gulf of Mexico

NASA Technical Reports Server (NTRS)

Habib, Shahid; Pickering, Ken; Tzortziou, Maria; Maninio, Antonio; Policelli, Fritz; Stehr, Jeff

2011-01-01

The Gulf of Mexico Modeling Framework is a suite of coupled models linking the deposition and transport of sediment and nutrients to subsequent bio-geo chemical processes and the resulting effect on concentrations of dissolved oxygen in the coastal waters of Louisiana and Texas. Here, we examine the potential benefits of using multiple NASA remote sensing data products within this Modeling Framework for increasing the accuracy of the models and their utility for nutrient control decisions in the Gulf of Mexico. Our approach is divided into three components: evaluation and improvement of (a) the precipitation input data (b) atmospheric constituent concentrations in EPA's air quality/deposition model and (c) the calculation of algal biomass, organic carbon and suspended solids within the water quality/eutrophication models of the framework.

Testing the Hypothesis of Biofilm as a Source for Soft Tissue and Cell-Like Structures Preserved in Dinosaur Bone.

PubMed

Schweitzer, Mary Higby; Moyer, Alison E; Zheng, Wenxia

2016-01-01

Recovery of still-soft tissue structures, including blood vessels and osteocytes, from dinosaur bone after demineralization was reported in 2005 and in subsequent publications. Despite multiple lines of evidence supporting an endogenous source, it was proposed that these structures arose from contamination from biofilm-forming organisms. To test the hypothesis that soft tissue structures result from microbial invasion of the fossil bone, we used two different biofilm-forming microorganisms to inoculate modern bone fragments from which organic components had been removed. We show fundamental morphological, chemical and textural differences between the resultant biofilm structures and those derived from dinosaur bone. The data do not support the hypothesis that biofilm-forming microorganisms are the source of these structures.

Investigations of Archaeological Glass Bracelets and Perfume Bottles Excavated in Ancient Ainos (Enez) by Multiple Analytical Techniques

NASA Astrophysics Data System (ADS)

Celik, S.; Akyuz, T.; Akyuz, S.; Ozel, A. E.; Kecel-Gunduz, S.; Basaran, S.

2018-03-01

Fragments of two perfume bottles belonging to the Hellenistic and Roman periods, and five bracelets belonging to the Roman, Byzantine, and Ottoman periods, excavated in the archaeological site of Enez during the excavations in 2000, have been investigated. The samples were analyzed using micro-Raman, FTIR, and energy dispersive X-ray fluorescence techniques, in order to study the ancient technology of glass production and to determine chemical compositions of the basic components and coloring elements of the glassware. All the investigated glasses can be characterized as low-magnesia-soda-lime silicate glasses, whose colors are induced by metal ions. The melting points of the investigated glasses are estimated to be quite close to each other and around 1000°C.

Mixed C18 and C1 modification on an optical fiber for chromatographic sensing.

PubMed

Zhou, Leiji; Wang, Kemin; Zuo, Xinbing; Choi, Martin M F; Chen, Yunqing; Huang, Shasheng

2003-09-01

An optical fiber-chromatographic sensor, aiming at simultaneous and selective response to multiple components following a chromatographic separation, is described. We report an improved approach for immobilization of octadecyl (C(18)) and methyl (C(1)) moieties as stationary phase on an optical fiber suitable as a sensing phase for organic solutes. By this approach, the stability and lifetime of the sensing layer as well as the detectability and retention behavior of the chromatographic sensor could be improved. Infrared spectroscopy was employed to confirm the presence of C(18) and C(1) moieties on the modified surface of the optical fiber. The chromatographic sensor was applied, with good sensitivity and chemical selectivity, to the simultaneous separation and detection of bromobenzene and toluene, using water as the mobile phase.

Heterogeneity of reward mechanisms.

PubMed

Lajtha, A; Sershen, H

2010-06-01

The finding that many drugs that have abuse potential and other natural stimuli such as food or sexual activity cause similar chemical changes in the brain, an increase in extracellular dopamine (DA) in the shell of the nucleus accumbens (NAccS), indicated some time ago that the reward mechanism is at least very similar for all stimuli and that the mechanism is relatively simple. The presently available information shows that the mechanisms involved are more complex and have multiple elements. Multiple brain regions, multiple receptors, multiple distinct neurons, multiple transmitters, multiple transporters, circuits, peptides, proteins, metabolism of transmitters, and phosphorylation, all participate in reward mechanisms. The system is variable, is changed during development, is sex-dependent, and is influenced by genetic differences. Not all of the elements participate in the reward of all stimuli. Different set of mechanisms are involved in the reward of different drugs of abuse, yet different mechanisms in the reward of natural stimuli such as food or sexual activity; thus there are different systems that distinguish different stimuli. Separate functions of the reward system such as anticipation, evaluation, consummation and identification; all contain function-specific elements. The level of the stimulus also influences the participation of the elements of the reward system, there are possible reactions to even below threshold stimuli, and excessive stimuli can change reward to aversion involving parts of the system. Learning and memory of past reward is an important integral element of reward and addictive behavior. Many of the reward elements are altered by repeated or chronic stimuli, and chronic exposure to one drug is likely to alter the response to another stimulus. To evaluate and identify the reward stimulus thus requires heterogeneity of the reward components in the brain.

An Informatics Approach to Evaluating Combined Chemical Exposures from Consumer Products: A Case Study of Asthma-Associated Chemicals and Potential Endocrine Disruptors

PubMed Central

Gabb, Henry A.; Blake, Catherine

2016-01-01

Background: Simultaneous or sequential exposure to multiple environmental stressors can affect chemical toxicity. Cumulative risk assessments consider multiple stressors but it is impractical to test every chemical combination to which people are exposed. New methods are needed to prioritize chemical combinations based on their prevalence and possible health impacts. Objectives: We introduce an informatics approach that uses publicly available data to identify chemicals that co-occur in consumer products, which account for a significant proportion of overall chemical load. Methods: Fifty-five asthma-associated and endocrine disrupting chemicals (target chemicals) were selected. A database of 38,975 distinct consumer products and 32,231 distinct ingredient names was created from online sources, and PubChem and the Unified Medical Language System were used to resolve synonymous ingredient names. Synonymous ingredient names are different names for the same chemical (e.g., vitamin E and tocopherol). Results: Nearly one-third of the products (11,688 products, 30%) contained ≥ 1 target chemical and 5,229 products (13%) contained > 1. Of the 55 target chemicals, 31 (56%) appear in ≥ 1 product and 19 (35%) appear under more than one name. The most frequent three-way chemical combination (2-phenoxyethanol, methyl paraben, and ethyl paraben) appears in 1,059 products. Further work is needed to assess combined chemical exposures related to the use of multiple products. Conclusions: The informatics approach increased the number of products considered in a traditional analysis by two orders of magnitude, but missing/incomplete product labels can limit the effectiveness of this approach. Such an approach must resolve synonymy to ensure that chemicals of interest are not missed. Commonly occurring chemical combinations can be used to prioritize cumulative toxicology risk assessments. Citation: Gabb HA, Blake C. 2016. An informatics approach to evaluating combined chemical exposures from consumer products: a case study of asthma-associated chemicals and potential endocrine disruptors. Environ Health Perspect 124:1155–1165; http://dx.doi.org/10.1289/ehp.1510529 PMID:26955064

Activity Enhancement Based on the Chemical Equilibrium of Multiple-Subunit Nitrile Hydratase from Bordetella petrii.

PubMed

Liu, Yi; Liu, Ping; Lin, Lu; Zhao, Yueqin; Zhong, Wenjuan; Wu, Lunjie; Zhou, Zhemin; Sun, Weifeng

2016-09-01

The maturation mechanism of nitrile hydratase (NHase) of Pseudomonas putida NRRL-18668 was discovered and named as "self-subunit swapping." Since the NHase of Bordetella petrii DSM 12804 is similar to that of P. putida, the NHase maturation of B. petrii is proposed to be the same as that of P. putida. However, there is no further information on the application of NHase according to these findings. We successfully rapidly purified NHase and its activator through affinity his tag, and found that the cell extracts of NHase possessed multiple types of protein ingredients including α, β, α2β2, and α(P14K)2 who were in a state of chemical equilibrium. Furthermore, the activity was significantly enhanced through adding extra α(P14K)2 to the cell extracts of NHase according to the chemical equilibrium. Our findings are useful for the activity enhancement of multiple-subunit enzyme and for the first time significantly increased the NHase activity according to the chemical equilibrium.

Tuning diagonal components of static linear and first nonlinear polarizabilities of doped quantum dots by Gaussian white noise

NASA Astrophysics Data System (ADS)

Ganguly, Jayanta; Ghosh, Manas

2015-07-01

We investigate the modulation of diagonal components of static linear (αxx, αyy) and first nonlinear (βxxx, βyyy) polarizabilities of quantum dots by Gaussian white noise. Quantum dot is doped with impurity represented by a Gaussian potential and repulsive in nature. The study reveals the importance of mode of application of noise (additive/multiplicative) on the polarizability components. The doped system is further exposed to a static external electric field of given intensity. As important observation we have found that the strength of additive noise becomes unable to influence the polarizability components. However, the multiplicative noise influences them conspicuously and gives rise to additional interesting features. Multiplicative noise even enhances the magnitude of the polarizability components immensely. The present investigation deems importance in view of the fact that noise seriously affects the optical properties of doped quantum dot devices.