Influence of the type of aqueous sodium silicate on the stabilization and rheology of kaolin clay suspensions

NASA Astrophysics Data System (ADS)

Izak, Piotr; Ogłaza, Longin; Mozgawa, Włodzimierz; Mastalska-Popławska, Joanna; Stempkowska, Agata

2018-05-01

To avoid agglomeration and sedimentation of grains, ceramic slurries should be modified by stabilizers in order to increase the electrostatic interactions between the dispersed particles. In this study we present the spectral analysis of aqueous sodium silicates obtained by different synthesis methods and their influence on the rheological properties of kaolin based slurries. Infrared and Raman spectra can be used to describe the structure of silicate structural units present in aqueous sodium silicates. It was confirmed that the best stabilization results possess aqueous sodium silicates of the silicate moduli of about 2 and the optimal concentration of the used fluidizer is 0.3 wt% to the kaolin clay dry mass. One of the most important conclusions is that the synthesis method of the fluidizer has no significant effect on its stabilization properties but used medium does create adequate stabilization mechanism depending on the silicate structures present in the sodium silicate solution.

Structure and composition of Fe-OM co-precipitates that form in soil-derived solutions

NASA Astrophysics Data System (ADS)

Fritzsche, Andreas; Schröder, Christian; Wieczorek, Arkadiusz K.; Händel, Matthias; Ritschel, Thomas; Totsche, Kai U.

2015-11-01

Iron oxides represent a substantial fraction of secondary minerals and particularly affect the reactive properties of natural systems in which they formed, e.g. in soils and sediments. Yet, it is still obscure how transient conditions in the solution will affect the properties of in situ precipitated Fe oxides. Transient compositions, i.e. compositions that change with time, arise due to predominant non-equilibrium states in natural systems, e.g. between liquid and solid phases in soils. In this study, we characterize Fe-OM co-precipitates that formed in pH-neutral exfiltrates from anoxic topsoils under transient conditions. We applied soil column outflow experiments, in which Fe2+ was discharged with the effluent from anoxic soil and subsequently oxidized in the effluent due to contact with air. Our study features three novel aspects being unconsidered so far: (i) the transient composition of soil-derived solutions, (ii) that pedogenic Fe oxides instead of Fe salts serve as major source for Fe2+ in soil solution and (iii) the presence of exclusively soil-derived organic and inorganic compounds during precipitation. The experiments were carried out with two topsoil materials that differed in composition, texture and land use. Derived from Mössbauer spectroscopy, broad distributions in quadrupole splittings (0-2 mm s-1) and magnetic hyperfine fields (35-53 T) indicated the presence of low-crystalline ferrihydrite and even lower crystalline Fe phases in all Fe-OM co-precipitates. There was no unequivocal evidence for other Fe oxides, i.e. lepidocrocite and (nano)goethite. The Fe-OM co-precipitates contained inorganic (P, sulfate, silicate, Al, As) and organic compounds (proteins, polysaccharides), which were concurrently discharged from the soils. Their content in the Fe-OM co-precipitates was controlled by their respective concentration in the soil-derived solution. On a molar basis, OC and Fe were the main components in the Fe-OM co-precipitates (OC/Fe ratio = 0.5-2). The elemental composition of the Fe-OM co-precipitates was in accordance with the sequential precipitation of Fe(III)phosphates/arsenates prior to the formation of ferrihydrite. This explains decreasing Si contents in the Fe-OM co-precipitates with increasing availability of P. With respect to constant mean quadrupole splittings and slightly decreasing mean magnetic hyperfine fields, increasing contents of OC, P and Al in the Fe-OM co-precipitates did not further increase the structural disorder of the Fe polyhedra, while the crystallite interactions slightly decreased. Scanning electron microscopy and dynamic light scattering revealed the coincidental presence of variably sized aggregates and a considerable amount of Fe-OM co-precipitates, which remained dispersed in solution for months. Thus, variably composed Fe-OM co-precipitates with highly diverse aggregate sizes and comparably constant poor crystallinity can be expected after the oxidation of Fe2+ in transient, soil-derived solutions.

Constraints on cosmic silicates

NASA Astrophysics Data System (ADS)

Ossenkopf, V.; Henning, Th.; Mathis, J. S.

1992-08-01

Observational determinations of opacities of circumstellar silicates, relative to the peak value near 10 microns, are used to estimate the optical constants n and k, the real and imaginary parts of the index of refraction. Circumstellar dust is modified by processing within the interstellar medium. This leads to higher band strengths and a somewhat larger ratio of the opacities at the 18 and 10-micron peaks, compared with circumstellar silicates. By using an effective-medium theory, we calculate the effects of small spherical inclusions of various materials (various oxides, sulfides, carbides, amorphous carbon, and metallic iron) upon silicate opacities. Some of these can increase the absorption coefficient k in the 2-8 micron region appreciably, as is needed to reconcile laboratory silicate opacities with observations of both the interstellar medium and envelopes around late-type stars. We give tables of two sets of optical constants for warm oxygen-deficient and cool oxygen-rich silicates, representative for circumstellar and interstellar silicates. The required opacity in the 2-8 micron region is provided by iron and magnetite.

Water diffusion in silicate glasses: the effect of glass structure

NASA Astrophysics Data System (ADS)

Kuroda, M.; Tachibana, S.

2016-12-01

Water diffusion in silicate melts (glasses) is one of the main controlling factors of magmatism in a volcanic system. Water diffusivity in silicate glasses depends on its own concentration. However, the mechanism causing those dependences has not been fully understood yet. In order to construct a general model for water diffusion in various silicate glasses, we performed water diffusion experiments in silica glass and proposed a new water diffusion model [Kuroda et al., 2015]. In the model, water diffusivity is controlled by the concentration of both main diffusion species (i.e. molecular water) and diffusion pathways, which are determined by the concentrations of hydroxyl groups and network modifier cations. The model well explains the water diffusivity in various silicate glasses from silica glass to basalt glass. However, pre-exponential factors of water diffusivity in various glasses show five orders of magnitude variations although the pre-exponential factor should ideally represent the jump frequency and the jump distance of molecular water and show a much smaller variation. Here, we attribute the large variation of pre-exponential factors to a glass structure dependence of activation energy for molecular water diffusion. It has been known that the activation energy depends on the water concentration [Nowak and Behrens, 1997]. The concentration of hydroxyls, which cut Si-O-Si network in the glass structure, increases with water concentration, resulting in lowering the activation energy for water diffusion probably due to more fragmented structure. Network modifier cations are likely to play the same role as water. With taking the effect of glass structure into account, we found that the variation of pre-exponential factors of water diffusivity in silicate glasses can be much smaller than the five orders of magnitude, implying that the diffusion of molecular water in silicate glasses is controlled by the same atomic process.

Effect of Fe2O3 on the physical and structural properties of bismuth silicate glasses

NASA Astrophysics Data System (ADS)

Parmar, Rajesh; Kundu, R. S.; Punia, R.; Aghamkar, P.; Kishore, N.

2013-06-01

Iron containing bismuth silicate glasses with compositions 70SiO2ṡ(100-x)Bi2O3ṡxFe2O3 have been prepared using conventional melt-quenching method and their amorphous nature has been investigated using XRD. Density has been measured using Archimedes' principle and molar volume (Vm) have also been estimated. With increase in Fe2O3 content, there is a decrease in density and molar volume of the glass samples. The glass transition temperature (Tg) have been determined using Differential Scanning Calorimetry (DSC) and are observed to increase with increase in Fe2O3 content. In the present glass system bismuth and iron plays the role of network modifier and the symmetry of silicate network goes on increasing with Fe2O3 content and it modifies the physical and structural properties of these glasses.

New poly(butylene succinate)/layered silicate nanocomposites: preparation and mechanical properties.

PubMed

Ray, Suprakas Sinha; Okamoto, Kazuaki; Maiti, Pralay; Okamoto, Masami

2002-04-01

New poly(butylene succinate) (PBS)/layered silicate nanocomposites have been successfully prepared by simple melt extrusion of PBS and octadecylammonium modified montmorillonite (C18-mmt) at 150 degrees C. The d-spacing of both C18-mmt and intercalated nanocomposites was investigated by wide-angle X-ray diffraction analysis. Bright-field transmission electron microscopic study showed several stacked silicate layers with random orientation in the PBS matrix. The intercalated nanocomposites exhibited remarkable improvement of mechanical properties in both solid and melt states as compared with that of PBS matrix without clay.

76 FR 14055 - Notice of Inventory Completion: California State Department of Transportation (Caltrans...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-15

... silicate core, 2 lots of debitage, 490 faunal bones, 2 flake tools, 61 tule mat impressions, 20 modified bones, 1 modified shell, 2 modified stones, 20 pieces of ochre, 14 ornaments, 3 pestles, 20 projectile..., 5 faunal bones, 1 flake tool, 1 modified bone, 1 quartz rock, 1 steatite ring, and 5 bone whistles...

Atomic hydrogen surrounded by water molecules, H(H2O)m, modulates basal and UV-induced gene expressions in human skin in vivo.

PubMed

Shin, Mi Hee; Park, Raeeun; Nojima, Hideo; Kim, Hyung-Chel; Kim, Yeon Kyung; Chung, Jin Ho

2013-01-01

Recently, there has been much effort to find effective ingredients which can prevent or retard cutaneous skin aging after topical or systemic use. Here, we investigated the effects of the atomic hydrogen surrounded by water molecules, H(H2O)m, on acute UV-induced responses and as well as skin aging. Interestingly, we observed that H(H2O)m application to human skin prevented UV-induced erythema and DNA damage. And H(H2O)m significantly prevented UV-induced MMP-1, COX-2, IL-6 and IL-1β mRNA expressions in human skin in vivo. We found that H(H2O)m prevented UV-induced ROS generation and inhibited UV-induced MMP-1, COX-2 and IL-6 expressions, and UV-induced JNK and c-Jun phosphorylation in HaCaT cells. Next, we investigated the effects of H(H2O)m on intrinsically aged or photoaged skin of elderly subjects. In intrinsically aged skin, H(H2O)m application significantly reduced constitutive expressions of MMP-1, IL-6, and IL-1β mRNA. Additionally, H(H2O)m significantly increased procollagen mRNA and also decreased MMP-1 and IL-6 mRNA expressions in photoaged facial skin. These results demonstrated that local application of H(H2O)m may prevent UV-induced skin inflammation and can modulate intrinsic skin aging and photoaging processes. Therefore, we suggest that modifying the atmospheric gas environment within a room may be a new way to regulate skin functions or skin aging.

Atomic Hydrogen Surrounded by Water Molecules, H(H2O)m, Modulates Basal and UV-Induced Gene Expressions in Human Skin In Vivo

PubMed Central

Shin, Mi Hee; Park, Raeeun; Nojima, Hideo; Kim, Hyung-Chel; Kim, Yeon Kyung; Chung, Jin Ho

2013-01-01

Recently, there has been much effort to find effective ingredients which can prevent or retard cutaneous skin aging after topical or systemic use. Here, we investigated the effects of the atomic hydrogen surrounded by water molecules, H(H2O)m, on acute UV-induced responses and as well as skin aging. Interestingly, we observed that H(H2O)m application to human skin prevented UV-induced erythema and DNA damage. And H(H2O)m significantly prevented UV-induced MMP-1, COX-2, IL-6 and IL-1β mRNA expressions in human skin in vivo. We found that H(H2O)m prevented UV-induced ROS generation and inhibited UV-induced MMP-1, COX-2 and IL-6 expressions, and UV-induced JNK and c-Jun phosphorylation in HaCaT cells. Next, we investigated the effects of H(H2O)m on intrinsically aged or photoaged skin of elderly subjects. In intrinsically aged skin, H(H2O)m application significantly reduced constitutive expressions of MMP-1, IL-6, and IL-1β mRNA. Additionally, H(H2O)m significantly increased procollagen mRNA and also decreased MMP-1 and IL-6 mRNA expressions in photoaged facial skin. These results demonstrated that local application of H(H2O)m may prevent UV-induced skin inflammation and can modulate intrinsic skin aging and photoaging processes. Therefore, we suggest that modifying the atmospheric gas environment within a room may be a new way to regulate skin functions or skin aging. PMID:23637886

Microstructure and mechanical properties of stainless steel/calcium silicate composites manufactured by selective laser melting.

PubMed

Zheng, Zeng; Wang, Lianfeng; Jia, Min; Cheng, Lingyu; Yan, Biao

2017-02-01

Selective laser melting (SLM) is raised as one kind of additive manufacturing (AM) which is based on the discrete-stacking concept. This technique can fabricate advanced composites with desirable properties directly from 3D CAD data. In this research, 316L stainless steel (316L SS) and different fractions of calcium silicate (CaSiO 3 ) composites (weight fractions of calcium silicate are 0%, 5%,10% and 15%, respectively) were prepared by SLM technique with a purpose to develop biomedical metallic materials. The relative density, tensile, microhardness and elastic modulus of the composites were tested, their microstructures and fracture morphologies were observed using optical microscope (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that the addition of CaSiO 3 particles influenced the microstructure and mechanical properties of specimens significantly. The CaSiO 3 precipitates from the overlap of adjacent tracks and became the origin of the defects. The tensile strength of specimens range 320-722MPa. The microhardness and elastic modulus are around 250HV and 215GPa respectively. These composites were ductile materials and the fracture mode of the composites was mixed mode of ductile and brittle fracture. The 316L SS/CaSiO 3 composites can be a potential biomedical metallic materials in the medical field. Copyright © 2016. Published by Elsevier B.V.

Nanoscale octahedral molecular sieves: Syntheses, characterization, and applications

NASA Astrophysics Data System (ADS)

Liu, Jia

The major part of this research consists of studies on novel synthesis methods, characterization, and catalytic applications of nanoscale manganese oxide octahedral molecular sieves. The second part involves studies of new applications of bulk porous molecular sieve and layered materials (MSLM), zeolites, and inorganic powder materials for diminishing wound bleeding. Manganese oxide octahedral molecular sieves (OMS) are very important microporous materials. They have been used widely as bulk materials in catalysis, separations, chemical sensors, and batteries, due to their unique tunnel structures and useful properties. Novel methods have been developed to synthesize novel nanoscale octahedral molecular sieve manganese oxides (OMS) and metal-substituted OMS materials in order to modify their physical and chemical properties and to improve their catalytic applications. Different synthetic routes were investigated to find better, faster, and cheaper pathways to produce nanoscale or metal-substituted OMS materials. In the synthetic study of nanosize OMS materials, a combination of sol-gel synthesis and hydrothermal reaction was used to prepare pure crystalline nanofibrous todorokite-type (OMS-1) and cryptomelane-typed (OMS-2) manganese oxides using four alkali cations (Li+, K+, Na +, Rb+) and NH4+ cations. In the synthesis study of nanoscale and metal-substituted OMS materials, a combination of sol-gel synthesis and solid-state reaction was used to prepare transition metal-substituted OMS-2 nanorods, nanoneedles, and nanowires. Preparative parameters of syntheses, such as cation templates, heating temperature and time, were investigated in these syntheses of OMS-1 and OMS-2 materials. The catalytic activities of the novel synthetic nanoscale OMS materials has been evaluated on green oxidation of alcohols and toluene and were found to be much higher than their correspondent bulk materials. New applications of bulk manganese oxide molecular sieve and layered materials (MSLM), zeolites, and several inorganic powder materials have also been studied for diminishing bleeding via in vitro tests using horse blood and in vivo tests on rat organs. MSLM, as well as several types of zeolite, and several inorganic compounds, have been found to have excellent ability to clot blood and arrest wound bleeding. Effects of properties of these porous materials on the efficiency of blood coagulation have been discussed.

Impacts of flocculation on the distribution and diagenesis of iron in boreal estuarine sediments

NASA Astrophysics Data System (ADS)

Jilbert, Tom; Asmala, Eero; Schröder, Christian; Tiihonen, Rosa; Myllykangas, Jukka-Pekka; Virtasalo, Joonas J.; Kotilainen, Aarno; Peltola, Pasi; Ekholm, Päivi; Hietanen, Susanna

2018-03-01

Iron (Fe) plays a key role in sedimentary diagenetic processes in coastal systems, participating in various redox reactions and influencing the burial of organic carbon. Large amounts of Fe enter the marine environment from boreal river catchments associated with dissolved organic matter (DOM) and as colloidal Fe oxyhydroxides, principally ferrihydrite. However, the fate of this Fe pool in estuarine sediments has not been extensively studied. Here we show that flocculation processes along a salinity gradient in an estuary of the northern Baltic Sea efficiently transfer Fe and OM from the dissolved phase into particulate material that accumulates in the sediments. Flocculation of Fe and OM is partially decoupled. This is likely due to the presence of discrete colloidal ferrihydrite in the freshwater Fe pool, which responds differently from DOM to estuarine mixing. Further decoupling of Fe from OM occurs during sedimentation. While we observe a clear decline with distance offshore in the proportion of terrestrial material in the sedimentary particulate organic matter (POM) pool, the distribution of flocculated Fe in sediments is modulated by focusing effects. Labile Fe phases are most abundant at a deep site in the inner basin of the estuary, consistent with input from flocculation and subsequent focusing. The majority of the labile Fe pool is present as Fe (II), including both acid-volatile sulfur (AVS)-bound Fe and unsulfidized phases. The ubiquitous presence of unsulfidized Fe (II) throughout the sediment column suggests Fe (II)-OM complexes derived from reduction of flocculated Fe (III)-OM, while other Fe (II) phases are likely derived from the reduction of flocculated ferrihydrite. Depth-integrated rates of Fe (II) accumulation (AVS-Fe + unsulfidized Fe (II) + pyrite) for the period 1970-2015 are greater in the inner basin of the estuary with respect to a site further offshore, confirming higher rates of Fe reduction in near-shore areas. Mössbauer 57Fe spectroscopy shows that refractory Fe is composed largely of superparamagnetic Fe (III), high-spin Fe (II) in silicates, and, at one station, also oxide minerals derived from past industrial activities. Our results highlight that the cycling of Fe in boreal estuarine environments is complex, and that the partial decoupling of Fe from OM during flocculation and sedimentation is key to understanding the role of Fe in sedimentary diagenetic processes in coastal areas.

Effects of sediment composition on inorganic mercury partitioning, speciation and bioavailability in oxic surficial sediments.

PubMed

Zhong, Huan; Wang, Wen-Xiong

2008-01-01

Artificially prepared sediments were used to assess the effects of sediment composition on inorganic Hg partitioning, speciation and bioavailability. Organic coating in sediment greatly increased the Hg partitioning and the amount of bioavailable Hg bound with the clay and the Fe and Mn oxides, but had little effect on that bound with the quartz and calcium carbonate as a result of weaker binding of humic acids and fulvic acids. The clay content increased the concentration of Hg in the sediments but inhibited the gut juice extraction due to the strong binding of Hg-organic matter (OM) complexes. Most Hg in the sediments was complexed by OM (mainly distributed in the organo-complexed phase and the strongly complexed phase), and the Hg-OM complexes (especially Hg in the strongly complexed phase) in sediments contributed much to gut juice extraction. Redistribution of Hg-OM complexes between sediments and gut juices may occur during gut juice extraction and modify Hg bioavailability and speciation in sediments.

Molecular simulation of dispersion and mechanical stability of organically modified layered silicates in polymer matrices

NASA Astrophysics Data System (ADS)

Fu, Yao-Tsung

The experimental analysis of nanometer-scale separation processes and mechanical properties at buried interfaces in nanocomposites has remained difficult. We have employed molecular dynamics simulation in relation to available experimental data to alleviate such limitations and gain insight into the dispersion and mechanical stability of organically modified layered silicates in hydrophobic polymer matrices. We analyzed cleavage energies of various organically modified silicates as a function of the cation exchange capacity, surfactant head group chemistry, and chain length using MD simulations with the PCFF-PHYLLOSILICATE force field. The range of the cleavage energy is between 25 and 210 mJ/m2 upon the molecular structures and packing of surfactants. As a function of chain length, the cleavage energy indicates local minima for interlayer structures comprised of loosely packed layers of alkyl chains and local maxima for interlayer structures comprised of densely packed layers of alkyl chains between the layers. In addition, the distribution of cationic head groups between the layers in the equilibrium state determines whether large increases in cleavage energy due to Coulomb attraction. We have also examined mechanical bending and failure mechanisms of layered silicates on the nanometer scale using molecular dynamics simulation in comparison to a library of TEM data of polymer nanocomposites. We investigated the energy of single clay lamellae as a function of bending radius and different cation density. The layer energy increases particularly for bending radii below 20 nm and is largely independent of cation exchange capacity. The analysis of TEM images of agglomerated and exfoliated aluminosilicates of different CEC in polymer matrices at small volume fractions showed bending radii in excess of 100 nm due to free volumes in the polymer matrix. At a volume fraction >5%, however, bent clay layers were found with bending radii <20 nm and kinks as a failure mechanism in good agreement with simulation results. We have examined thermal conductivity of organically modified layered silicates using molecular dynamics simulation in comparison to experimental results by laser measurement. The thermal conductivity slightly increased from 0.08 to 0.14 Wm-1K-1 with increasing chain length, related to the gallery spacing and interlayer density of the organic material.

Multifunctional Composites for Improved Polyimide Thermal Stability

NASA Technical Reports Server (NTRS)

Miller, Sandi G.

2007-01-01

The layered morphology of silicate clay provides an effective barrier to oxidative degradation of the matrix resin. However, as resin thermal stability continues to reach higher limits, development of an organic modification with comparable temperature capabilities becomes a challenge. Typically, phyllosilicates used in polymer nanocomposites are modified with an alkyl ammonium ion. Such organic modifiers are not suited for incorporation into high temperature polymers as they commonly degrade below 200oC. Therefore, the development of nanoparticle specifically suited for high temperature applications is necessary. Several nanoparticles were investigated in this study, including pre-exfoliated synthetic clay, an organically modified clay, and carbon nanofiber. Dispersion of the layered silicate increases the onset temperature of matrix degradation as well as slows oxidative degradation. The thermally stable carbon nanofibers are also observed to significantly increase the resin thermal stability.

Investigation of hydrogen concentration and hardness of ion irradiated organically modified silicate thin films

NASA Astrophysics Data System (ADS)

Qi, Y.; Prenzel, T.; Harriman, T. A.; Wang, Y. Q.; Lucca, D. A.; Williams, D.; Nastasi, M.; Dong, J.; Mehner, A.

2010-06-01

A study of the effects of ion irradiation of organically modified silicate thin films on the loss of hydrogen and increase in hardness is presented. NaOH catalyzed SiNa wO xC yH z thin films were synthesized by sol-gel processing from tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) precursors and spin-coated onto Si substrates. After drying at 300 °C, the films were irradiated with 125 keV H + or 250 keV N 2+ at fluences ranging from 1 × 10 14 to 2.5 × 10 16 ions/cm 2. Elastic Recoil Detection (ERD) was used to investigate resulting hydrogen concentration as a function of ion fluence and irradiating species. Nanoindentation was used to measure the hardness of the irradiated films. FT-IR spectroscopy was also used to examine resulting changes in chemical bonding. The resulting hydrogen loss and increase in hardness are compared to similarly processed acid catalyzed silicate thin films.

Influence of Chemical Conditions on the Nanoporous Structure of Silicate Aerogels

PubMed Central

Sinkó, Katalin

2010-01-01

Silica or various silicate aerogels can be characterized by highly porous, open cell, low density structures. The synthesis parameters influence the three-dimensional porous structures by modifying the kinetics and mechanism of hydrolysis and condensation processes. Numerous investigations have shown that the structure of porous materials can be tailored by variations in synthesis conditions (e.g., the type of precursors, catalyst, and surfactants; the ratio of water/precursor; the concentrations; the medium pH; and the solvent). The objectives of this review are to summarize and elucidate the effects of chemical conditions on the nanoporous structure of sol-gel derived silicate aerogels.

Hydrocarbon potential of the Early Oligocene Menilite shales in the Eastern Outer Carpathians (Tarcău and Vrancea Nappes, Romania)

NASA Astrophysics Data System (ADS)

Wendorff, Małgorzata; Rospondek, Mariusz; Kluska, Bartosz; Marynowski, Leszek

2017-04-01

During Oligocene to early Miocene time an extensive accumulation of organic-rich sedimentary rocks occurred in entire Paratethyan Basin, including its central part, i.e. the Carpathian Foredeep basin. Rocks of so-called Menilite facies formed there, burying significant amounts of organic matter (OM). These Menilite shales are now widely considered as a source of hydrocarbons throughout the Carpathian region. For the purpose of presented study, rock samples of the Menilite facies (mainly of the Lower Menilite and Bituminous Marl Members) were collected from two sections located in the different tectonic units (the Tarcău and Vrancea Nappes, Romania) of the Outer Carpathians. The main goal of the study was to assess and compare their hydrocarbon potential by examination of bulk geochemistry (total organic carbon content, pyrolysis Rock-Eval), vitrinite reflectance (Ro) and application of lipid biomarker parameters. The data show high variability in OM quantity and quality. Total organic carbon (TOC) content reaches peak values in the siliceous facies of the Lower Menilite Member (up to 8.6 wt% TOC), which contains type II kerogen represented by mainly marine OM type. Such results are confirmed by the presence of short-chain n-alkanes and hopanes. Mixed type II/III kerogen gains importance together with increasing contribution of turbiditic sedimentation. Terrigenous input is marked by occurrence of conifer aromatic biomarkers (such as simonellite, retene and 1,2,3,4-tetrahydroretene) and odd over even long chain n-alkanes predominance, characteristic for epicuticular leaf waxes. The analysed source rocks can be classified as oil-prone and subordinately mixed oil/gas-prone. OM in the inner tectonic unit (Tarcău Nappe; Tmax 430° C, Ro 0.5%) reaches onset of hydrocarbon generation, while in the outer unit (Vrancea Nappe) OM is immature (Tmax 425° C, Ro 0.4%). This maturity trend may be an effect of different burial histories of these units, as well as variation in subsequent erosion and exhumation levels resulting from the more inner position of the Tarcău Nappe within the orogen relative to the Vrancea Nappe (Wendorff et al., 2017). Based on the TOC content, S1 and S2 peak values the investigated rocks from the Vrancea Nappe reveal good to even excellent petroleum potential (especially for the siliceous facies of the Lower Menilite Mb.), although they did not attain the oil-window stage. The Tarcău Nappe source rocks have fair to good hydrocarbon potential. Hydrocarbons have been locally generated due to sufficient maturity, as also confirmed by high extractable bitumen yields and field observation of solid bitumen veins. However, hydrocarbon potential has not been exhausted as revealed by still high hydrocarbon index values. In the studied area the rocks of the Menilite facies have been suggested as a source for small gas/oil deposits, i.e. the Cuejdiu and Moineşti/Comăneşti field. References Wendorff, M., Rospondek, M., Kluska, B., Marynowski, L., 2017. Organic matter maturity and hydrocarbon potential of the Lower Oligocene Menilite facies in the Eastern Flysch Carpathians (Tarcău and Vrancea Nappes), Romania. Applied Geochemistry (in press).

High temperature calorimetric studies of heat of solution of NiO, CuO, La2O3, TiO2, HfO2 in sodium silicate liquids

NASA Astrophysics Data System (ADS)

Linard, Yannick; Wilding, Martin C.; Navrotsky, Alexandra

2008-01-01

The enthalpies of solution of La2O3, TiO2, HfO2, NiO and CuO were measured in sodium silicate melts at high temperature. When the heat of fusion was available, we derived the corresponding liquid-liquid enthalpies of mixing. These data, combined with previously published work, provide insight into the speciation reactions in sodium silicate melts. The heat of solution of La2O3 in these silicate solvents is strongly exothermic and varies little with La2O3 concentration. The variation of heat of solution with composition of the liquid reflects the ability of La(III) to perturb the transient silicate framework and compete with other cations for oxygen. The enthalpy of solution of TiO2 is temperature-dependent and indicates that the formation of Na-O-Si species is favored over Na-O-Ti at low temperature. The speciation reactions can be interpreted in terms of recent spectroscopic studies of titanium-bearing melts which identify a dual role of Ti4+ as both a network-former end network-modifier. The heats of solution of oxides of transition elements (Ni and Cu) are endothermic, concentration-dependent and reach a maximum with concentration. These indicate a charge balanced substitution which diminishes the network modifying role of Na+ by addition of Ni2+ or Cu2+. The transition metal is believed to be in tetrahedral coordination, charge balanced by the sodium cation in the melts.

Spatial variability in the abundance, composition, and age of organic matter in surficial sediments of the East China Sea

NASA Astrophysics Data System (ADS)

Wu, Ying; Eglinton, Timothy; Yang, Liyang; Deng, Bing; Montluçon, Daniel; Zhang, Jing

2013-12-01

the sources and fate of organic matter (OM) sequestered in continental margin sediments is of importance because the mode and efficiency of OM burial impact the carbon cycle and the regulation of atmospheric CO2 over long time scales. We carried out molecular (lignin-derived phenols from CuO oxidation), elemental, isotopic (δ13C, Δ14C), and sedimentological (grain size and mineral surface area) analyses in order to examine spatial variability in the abundance, source, age of surface sediments of the East China Sea. Higher terrigenous organic matter values were found in the main accumulating areas of fluvial sediments, including the Changjiang (Yangtze) Estuary and Zhejiang-Fujian coastal zone. Isotopic and biomarker data suggest that the sedimentary OM in the inner shelf region was dominated by aged (Δ14C = -423 ± 42‰) but relatively lignin-rich OM (Λ = 0.94 ± 0.57 mg/100 mg OC) associated with fine-grained sediments, suggesting important contributions from soils. In contrast, samples from the outer shelf, while of similar age (Δ14 C = -450 ± 99‰), are lignin poor (Λ = 0.25 ± 0.14 mg/100 mg OC) and associated with coarse-grained material. Regional variation of lignin phenols and OM ages indicates that OM content is fundamentally controlled by hydrodynamic sorting (especially, sediment redistribution and winnowing) and in situ primary production. Selective sorption of acid to aldehyde in clay fraction also modified the ratios of lignin phenols. The burial of lignin in East China Sea is estimated to be relatively efficient, possibly as a consequence of terrigenous OM recalcitrance and/or relatively high sedimentation rates in the Changjiang Estuary and the adjacent Zhejing-Fujian mud belt.

NMR spectroscopic study of the carbon and nitrogen dynamics of grass-derived pyrogenic organic material during 2.3 years of incubation in soil

NASA Astrophysics Data System (ADS)

Hilscher, André; Knicker, Heike

2010-05-01

Incomplete combustion of vegetation results in pyrogenic organic material (PyOM) which occurs ubiquitously in soils and sediments. To understand the C sequestration potential of PyOM in environmental systems knowledge is required about the respective degradation and humification mechanisms and the stability of the different chemical PyOM structures. The present study focuses on the microbial recalcitrance of PyOM on molecular scale. Therefore, microcosms incubation experiments were performed using PyOM produced from highly isotopically enriched 13C and 15N rye grass (Lolium perenne) at 350°C under oxic conditions for one (1M) and four minutes (4M). Solid-state CPMAS 13C and 15N NMR studies were accomplished to obtain insights into the involved humification mechanisms at different stages the PyOM degradation. In total up to 38% of the bulk PyOM C was mineralised during the 28 months of incubation. The O/N-alkyl C and alkyl C residues which survived the charring process were effectively decomposed. At the end of the incubation up to 73% and 57% of the initial O/N-alkyl C and alkyl C amount were mineralised or converted to other C groups, respectively. The total aryl C group recovery of the PyOM decreased significantly during the 28 months of incubation (P ≤ 0.001). After 20 months of incubation between 26% and 40% of the initial aryl C amount was lost. For this group, relative short half time periods in the range of 3.0 and 3.8 years were obtained. The observed loss of aromatic C structures may be attributed to two simultaneous processes, the mineralisation to CO2 and the conversion to other C groups by partial oxidation. The presence of a readily decomposable co-substrate showed no significant changes in the degradation pattern of the different PyOM, possibly because decomposable sources were already available in the starting PyOM. Most of the organic bound N of the fresh PyOM was assignable to heterocyclic aromatic compounds such as pyrrole and indole-like structures with contributions of 62% and 72% for PyOM 1M and PyOM 4M, respectively. The other part of the 15N NMR signal intensity was assignable to amide-like structures. No major alteration of the amide and heterocyclic N contribution was detected for the PyOM 1M incubates. For the more charred PyOM 4M, the relative heterocyclic N contribution decreased. After the 28 months of incubation no significant difference in the chemical N composition of PyOM 4M related to the PyOM 1M treatments could be observed (P=0.472). Further, we detect a continuous degrease of the total amounts for the amide and heterocyclic N compounds. After 20 months, only 49% to 59% of the heterocyclic N compounds were recovered. The respective amide N recoveries were larger with 59% to 87%. It can be concluded, that PyOM may not be as highly refractory as it is commonly assumed. During the efficient degradation not only a considerable PyOM amount is mineralised, but also the chemical structure of the remaining PyOM is strongly modified. This includes the formation of O-containing functional groups and the loss of aromatic C and N containing heterocyclic domains by mineralisation and conversion to other C and N groups.

Analysis of the Barrier Properties of Polyimide-Silicate Nanocomposites

NASA Technical Reports Server (NTRS)

Campbell, Sandi; Johnston, J. Chris; Inghram, Linda; McCorkle, Linda; Silverman, Edward

2003-01-01

Montmorillonite clay was organically modified and dispersed into a thermoplastic (BPADA-BAPP) and a thermosetting (PMR-15) polyimide matrix. The barrier properties of the neat resins and the nanocomposites were evaluated. Reductions in gas permeability and water absorption were observed in thermoplastic polyimide nanocomposites. The thermosetting polyimide showed a reduction in weight loss during isothermal aging at 288 C. Carbon fabric (T650-35, 8 HS, 8 ply) composites were prepared using both the BPADE-BAPP and PMR-15 based nanocomposites. Dispersion of the layered silicate in the BPADA-BAPP matrix reduced helium permeability by up to 70 percent. The PMR-15/ silicate nanocomposite matrix had an increase in thermal oxidative stability of up to 25 percent.

Physical characteristics, antimicrobial and odontogenesis potentials of calcium silicate cement containing hinokitiol.

PubMed

Huang, Ming-Hsien; Shen, Yu-Fang; Hsu, Tuan-Ti; Huang, Tsui-Hsien; Shie, Ming-You

2016-08-01

Hinokitiol is a natural material and it has antibacterial and anti-inflammatory effects. The purpose of this study was to evaluate the material characterization, cell viability, antibacterial and anti-inflammatory abilities of the hinokitiol-modified calcium silicate (CS) cement as a root end filling material. The setting times, diametral tensile strength (DTS) values and XRD patterns of CS cements with 0-10mM hinokitiol were examined. Then, the antibacterial effect and the expression levels of cyclooxygenase 2 (COX-2) and interleukin-1 (IL-1) of the hinokitiol-modified CS cements were evaluated. Furthermore, the cytocompatibility, the expression levels of the markers of odontoblastic differentiation, mineralized nodule formation and calcium deposition of human dental pulp cells (hDPCs) cultured on hinokitiol-modified CS cements were determined. The hinokitiol-modified CS cements had better antibacterial and anti-inflammatory abilities and cytocompatibility than non-modified CS cements. Otherwise, the hinokitiol-modified CS cements had suitable setting times and better odontoblastic potential of hDPCs. Previous report pointed out that the root-end filling materials may induce inflammatory cytokines reaction. In our study, hinokitiol-modified CS cements not only inhibited the expression level of inflammatory cytokines, but also had better cytocompatibility, antimicrobial properties and active ability of odontoblastic differentiation of hDPCs. Therefore, the hinokitiol-modified CS cement may be a potential root end filling material for clinic. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis of Non-Toxic Silica Particles Stabilized by Molecular Complex Oleic-Acid/Sodium Oleate

PubMed Central

Spataru, Catalin Ilie; Ianchis, Raluca; Petcu, Cristian; Nistor, Cristina Lavinia; Purcar, Violeta; Trica, Bogdan; Nitu, Sabina Georgiana; Somoghi, Raluca; Alexandrescu, Elvira; Oancea, Florin; Donescu, Dan

2016-01-01

The present work is focused on the preparation of biocompatible silica particles from sodium silicate, stabilized by a vesicular system containing oleic acid (OLA) and its alkaline salt (OLANa). Silica nanoparticles were generated by the partial neutralization of oleic acid (OLA), with the sodium cation present in the aqueous solutions of sodium silicate. At the molar ratio OLA/Na+ = 2:1, the molar ratio (OLA/OLANa = 1:1) required to form vesicles, in which the carboxyl and carboxylate groups have equal concentrations, was achieved. In order to obtain hydrophobically modified silica particles, octadecyltriethoxysilane (ODTES) was added in a sodium silicate sol–gel mixture at different molar ratios. The interactions between the octadecyl groups from the modified silica and the oleyl chains from the OLA/OLANa stabilizing system were investigated via simultaneous thermogravimetry (TG) and differential scanning calorimetry (DSC) (TG-DSC) analyses.A significant decrease in vaporization enthalpy and an increase in amount of ODTES were observed. Additionally, that the hydrophobic interaction between OLA and ODTES has a strong impact on the hybrids’ final morphology and on their textural characteristics was revealed. The highest hydrodynamic average diameter and the most negative ζ potential were recorded for the hybrid in which the ODTES/sodium silicate molar ratio was 1:5. The obtained mesoporous silica particles, stabilized by the OLA/OLANa vesicular system, may find application as carriers for hydrophobic bioactive molecules. PMID:27869768

Chronic traumatic ankle and foot osteomyelitis: a nationwide case-control study.

PubMed

Hosseini, Maryam; Allami, Mostafa; Soroush, Mohammadreza; Babaha, Fateme; Minooeefar, Javad; Rahimpoor, Davood

2018-05-15

Osteomyelitis (OM) is an atypical consequence of ankle-foot trauma which is associated with long-term mental and physical morbidity and persistent pain. This study aimed to assess the health status of OM patients with war-related ankle-foot injuries. A total of 1129 veterans with ankle-foot injuries participated in a case-control study (2014-2016). Thirty patients with chronic OM of the ankle-foot were compared with 90 non-OM participants as the control group. Quality of life (QOL), life satisfaction and the ability to perform basic and instrumental activities of daily living were measured using the following questionnaires: short-form health survey (SF-36), satisfaction with life scale (SWLS), activity of daily living (ADL) and instrumental activity of daily living (IADL), respectively. OM patients were categorized according to their risk factors as A, B and C hosts using a modified version of the Cierny and Mader classification system. The one sample t-test, 2-independent sample t-test, ANOVA, Pearson correlation coefficient and multiple linear regression analyses were applied to analyze the data. Ankle-foot pain leading to surgery (P < 0.001) and orthosis usage (P = 0.039) were more common in OM patients. There was no significant difference between the two groups in the prevalence of pulmonary and cardiovascular diseases or kidney failure and other related diseases. OM patients showed a significantly lower level of mental health compared to non-OM respondents (P = 0.025). Approximately, 70.0% of ankle-foot injured veterans were dissatisfied with their life, and there was no difference between the two groups (P > 0.05). Mobility was significantly lower in the OM patients than in the control group (P = 0.023). Life satisfaction (P = 0.001) and the ability to perform daily activities were the determinants for poor physical (P = 0.018) and mental (P = 0.012) health-related quality of life. According to the Cierny and Mader classification system, they were all included in the type C host classification, with one major and/or three or more minor risk factors. A low level of quality and satisfaction of life and ability to perform activities of daily living were observed in OM patients with war-related ankle-foot injuries. Surgeries of the ankle and foot due to pain were much more common in OM patients than in non-OM participants. Since all the participants were classified as the C-host, health policy planning seems to be necessary.

Characterization of layered silicate-reinforced blends of thermoplastic starch (TPS) and poly(butylene adipate-co-terephthalate).

PubMed

Lendvai, László; Apostolov, Anton; Karger-Kocsis, József

2017-10-01

A two-step melt blending procedure was used to produce binary systems composed of thermoplastic starch (TPS) and poly(butylene adipate-co-terephthalate) (PBAT). To improve the properties of the blends, two different layered silicates, viz. bentonite (BT) and organically modified montmorillonite (oMMT) were incorporated. First, TPS and its layered silicate nanocomposites were prepared via extrusion compounding during which starch was plasticized with glycerol and water. In the second step, PBAT was added to TPS/layered silicate to produce blends in a batch-type mixer. Mechanical and thermal properties were determined. The blends showed acceptable ductility over 50wt.% PBAT content, although at the cost of strength and stiffness. By contrast to oMMT the BT became intercalated in TPS and TPS/PBAT blends. The reinforcing effect of BT and oMMT was most prominent for the glassy states of both TPS and TPS/PBAT blends. Thermal, and thermooxidative properties were not significantly affected by the presence of layered silicates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Connecting marine productivity to sea-spray via nanoscale biological processes: Phytoplankton Dance or Death Disco?

NASA Astrophysics Data System (ADS)

O'Dowd, Colin; Ceburnis, Darius; Ovadnevaite, Jurgita; Bialek, Jakub; Stengel, Dagmar B.; Zacharias, Merry; Nitschke, Udo; Connan, Solene; Rinaldi, Matteo; Fuzzi, Sandro; Decesari, Stefano; Cristina Facchini, Maria; Marullo, Salvatore; Santoleri, Rosalia; Dell'Anno, Antonio; Corinaldesi, Cinzia; Tangherlini, Michael; Danovaro, Roberto

2015-10-01

Bursting bubbles at the ocean-surface produce airborne salt-water spray-droplets, in turn, forming climate-cooling marine haze and cloud layers. The reflectance and ultimate cooling effect of these layers is determined by the spray’s water-uptake properties that are modified through entrainment of ocean-surface organic matter (OM) into the airborne droplets. We present new results illustrating a clear dependence of OM mass-fraction enrichment in sea spray (OMss) on both phytoplankton-biomass, determined from Chlorophyll-a (Chl-a) and Net Primary Productivity (NPP). The correlation coefficient for OMss as a function of Chl-a increased form 0.67 on a daily timescale to 0.85 on a monthly timescale. An even stronger correlation was found as a function of NPP, increasing to 0.93 on a monthly timescale. We suggest the observed dependence is through the demise of the bloom, driven by nanoscale biological processes (such as viral infections), releasing large quantities of transferable OM comprising cell debris, exudates and other colloidal materials. This OM, through aggregation processes, leads to enrichment in sea-spray, thus demonstrating an important coupling between biologically-driven plankton bloom termination, marine productivity and sea-spray modification with potentially significant climate impacts.

Organosilane self-assembled layers (SAMs) and hybrid silicate magnesium-rich primers for the corrosion protection of aluminum alloy 2024 T3

NASA Astrophysics Data System (ADS)

Wang, Duhua

Although current chromate coatings function very well in corrosion protection for aircraft alloys, such as aluminum alloy 2024 T3, the U.S. Environmental Protection Agency is planning to totally ban the use of chromates as coating materials in the next decade or so because of their extremely toxic effect. For this purpose, both self-assembled layers and silicate magnesium-rich primers were tested to provide the corrosion protection for aluminum alloy. The long-term goal of this research is to develop a coating system to replace the current chromate coating for aircraft corrosion protection. Aluminum alloy 2024 T3 substrates were modified with self-assembled monolayer or multilayer thin films from different alkylsilane compounds. Mono-functional silanes, such as octadecyltrichlorosilane (C18SiCl3), can form a mixed hydrophobic monolayer or multilayer thin film on the aluminum oxide surface to provide a barrier to water and other electrolytes, so the corrosion resistance of the SAMs modified surface was increased significantly. On the other hand, the bi-functional silane self-assembly could attach the aluminum surface through the silicon headgroup while using its functional tailgroup to chemically bond the polymer coating, thus improving the adhesion between the aluminum substrate and coating substantially, and seems to contribute more to corrosion protection of aluminum substrate. Organosilanes were also combined with tetraethyl orthosilicate (TEOS) in propel ratios to form a sol-gel binder to make silicate magnesium-rich primers. Analogue to the inorganic zinc-rich coatings, the silicate magnesium-rich primers also showed excellent adhesion and solvent resistance. The sacrificial magnesium pigments and the chemically inert silicate binder both contribute to the anti-corrosion properties. Future studies will be focused on the formula optimization for better toughness, chemical resistance and anticorrosion performance.

Using MELTS to understand the evolution of silicic magmas: Challenges and successes in modeling the Highland Range Volcanic Sequence (NV)

NASA Astrophysics Data System (ADS)

Vaum, R. C.; Gualda, G. A.; Ghiorso, M. S.; Miller, C. F.; Colombini, L. L.

2009-12-01

The Highland Range near Searchlight, Nevada is comprised of mid-Miocene, intermediate to silicic volcanic rocks. This study focuses on the most silicic portion of the eruptive sequence (16.0-16.5 Ma). The first eruptions during this interval were effusive and produced trachydacite (66-70 wt% SiO2), but later the eruptive style shifted to explosive and compositions were more evolved (70-78 wt% SiO2). Glass compositions in rocks saturated in both quartz and sanidine align along the 150 MPa quartz+sanidine saturation surface, suggesting that the Highland Range magmas equilibrated in a single reservoir at that pressure. We are interested in better understanding this transition in eruptive style from effusive to eruptive, and our approach is based on modeling melt evolution using MELTS thermodynamic modeling software. We selected representative samples from key stratigraphic units, and focused on samples for which whole-rock and glass compositions, as well as mineral abundances, are available. This allows for direct comparison of simulation results with existing data. Initial simulations showed that MELTS predicts unrealistic paths of evolution when compared to the glass compositions and to the phase relations in the Qz-Ab-Or ternary. In particular, the stability field of quartz predicted by MELTS is much too small, causing melts to become exceedingly silicic (>80 wt% SiO2). Sanidine, on the other hand, has fairly sodic compositions and crystallizes too early in the sequence; therefore, simulated melt compositions are never as potassic as the analyzed glasses. Similar results are obtained when modeling the evolution of the Bishop and Campanian magmas, showing that these are systematic problems in MELTS calibration. Accordingly, we have adjusted the enthalpy of quartz and potassium end-member of the feldspar solid solution in MELTS so that the quartz-sanidine saturation surface is correctly predicted. We find that this modified version of MELTS much better models the evolution of silicic magmas. Sanidine begins to crystallize at lower temperatures, causing evolved melts to become significantly more potassic. Also, MELTS prediction of quartz saturation is in agreement with the position of the experimentally determined 150 MPa quartz+sanidine saturation surface. Importantly, the melt evolution that this modified version of MELTS predicts is very consistent with whole-rock data, glass chemistry, and mineral abundances in samples from the Highland Range. Simulations using the modified version of MELTS show that it works remarkably well, at least for relatively low degrees of crystallization. But a more reliable model to simulate the evolution of silicic magmas is necessary to more properly simulate the evolution of silicic systems, in particular at high degrees of crystallinity. We are currently working to create gMELTS, an associated solution model of the haplogranitic system, which, once completed, will be optimized to simulate the evolution of silicic systems.

Photo- and electroluminescence of sulfide and silicate phosphors embedded in synthetic opal

NASA Astrophysics Data System (ADS)

Kaplan, S. F.; Kartenko, N. F.; Kurdyukov, D. A.; Medvedev, A. V.; Badalyan, A. G.; Golubev, V. G.

2007-02-01

The sulfide (ZnS:Mn, Zn xCd 1 -xS:Mn, Zn xCd 1- xS:Ag) and silicate (Zn 2SiO 4:Mn) phosphors were synthesized directly inside the pores of synthetic opal by chemical bath deposition. These composites are perfect three-dimensional photonic crystals, which produce effective photo- and electroluminescence at room temperature. The emission spectra are considerably modified by the photonic crystal structure to become anisotropic in accordance with the photonic band gap angular dispersion.

BALB/c alleles at modifier loci increase the severity of the maternal effect of the "DDK syndrome".

PubMed Central

Le Bras, S; Cohen-Tannoudji, M; Kress, C; Vandormael-Pournin, S; Babinet, C; Baldacci, P

2000-01-01

The Om locus was first described in the DDK inbred mouse strain: DDK mice carry a mutation at Om resulting in a parental effect lethality of F(1) embryos. When DDK females are mated with males of other (non-DDK) inbred strains, e.g., BALB/c, they exhibit a low fertility, whereas the reciprocal cross, non-DDK females x DDK males, is fertile (as is the DDK intrastrain cross). The low fertility is due to the death of (DDK x non-DDK)F(1) embryos at the late-morula to blastocyst stage, which is referred to as the "DDK syndrome." The death of these F(1) embryos is caused by an incompatibility between a DDK maternal factor and the non-DDK paternal pronucleus. Previous genetic studies showed that F(1) mice have an intermediate phenotype compared to parental strains: crosses between F(1) females and non-DDK males are semisterile, as are crosses between DDK females and F(1) males. In the present studies, we have examined the properties of mice heterozygous for BALB/c and DDK Om alleles on an essentially BALB/c genetic background. Surprisingly, we found that the females are quasi-sterile when mated with BALB/c males and, thus, present a phenotype similar to DDK females. These results indicate that BALB/c alleles at modifier loci increase the severity of the DDK syndrome. PMID:10655231

Characteristics of organic matter fractions separated by wet-sieving and differences in density from five soils of different pedogenesis under mature beech forest.

NASA Astrophysics Data System (ADS)

Vormstein, Svendja; Kaiser, Michael; Ludwig, Bernard

2017-04-01

Forest top- and subsoil account for approximately 70 % of the organic C (OC) globally stored in soil reasoning their large importance for terrestrial ecosystem services such as the mitigation of climate change. In contrast to forest topsoil, there is much less information about the decomposition and stabilization of organic matter (OM) in subsoil. Therefore, we sampled the pedogenetic horizons of five soils under mature beech forest developed on different parent material (i.e. Tertiary Sand, Loess, Basalt, Lime Stone, Red Sandstone) down to the bedrock. The bulk soil samples were characterized for texture, oxalate and dithionite soluble Fe and Al, pH, OC, microbial biomass C and basal respiration (cumulative CO2 emission after 7 and 14 days). Furthermore, we analyzed aggregate size fractions separated by wet-sieving (i.e. >1000 µm, 1000-250 µm, 250-53 µm, <53 µm) and density fractions separated using NaPT (i.e. light, occluded light, and heavy fraction) from the soil horizon specific samples. The OC of the topsoil (Ah horizon) on Lime Stone and Red Sandstone was predominately stored in the larger macro-aggregates (>1000 µm). In contrast, the major part of the topsoil OC on Basalt and Tertiary Sand was found in the smaller macro-aggregates (1000-250 µm). For the topsoil samples, we found that the basal respiration as well as the microbial biomass C were positively correlated (p ≤0.05) with the OC amounts associated with the free and occluded light fraction and with the macro-aggregates (1000-250 µm) and micro-aggregates (250-53 µm) suggesting these fractions to store the major part of the easily decomposable OM. The OC amount associated with the heavy fraction and the fraction <53 µm was correlated with the contents of oxalate and dithionite soluble Fe and Al suggesting interactions between organic compounds and Fe- and Al-oxides to be highly important for the OM stabilization in forest topsoil. In the subsoil (horizons below the Ah), the contribution of the OC associated with the aggregate size fractions <250 µm to the OC stored in the subsoil increased with depth. The OC contents associated with the free and occluded light as well as the heavy fraction and with the aggregate size fractions >53 µm were positively correlated with basal respiration and the microbial biomass C. This suggests, in contrast to the topsoil, the easily decomposable OM to be distributed more homogeneously among fractions. Only the OC content of the <53 µm fraction showed positive correlations to soil mineral characteristics such as the contents of clay oxalate and dithionite soluble Fe or Al and no relationship to the basal respiration and microbial biomass C. This indicates the OM associated with this fraction to be most diagnostic for the amount of OC stabilized against microbial decay in the subsoil and interactions between OM and oxides as well as layer silicates to be relevant stabilization mechanisms. The results point toward similar OM stabilization mechanisms in the analysed forest top- and subsoils but revealed differences in the distribution of easily decomposable OM within the soil matrix.

The viscosity of magmatic silicate liquids: A model for calculation

NASA Technical Reports Server (NTRS)

Bottinga, Y.; Weill, D. F.

1971-01-01

A simple model has been designed to allow reasonably accurate calculations of viscosity as a function of temperature and composition. The problem of predicting viscosities of anhydrous silicate liquids has been investigated since such viscosity numbers are applicable to many extrusive melts and to nearly dry magmatic liquids in general. The fluidizing action of water dissolved in silicate melts is well recognized and it is now possible to predict the effect of water content on viscosity in a semiquantitative way. Water was not incorporated directly into the model. Viscosities of anhydrous compositions were calculated, and, where necessary, the effect of added water and estimated. The model can be easily modified to incorporate the effect of water whenever sufficient additional data are accumulated.

Oral and maxillofacial surgery residents have poor understanding of biostatistics.

PubMed

Best, Al M; Laskin, Daniel M

2013-01-01

The purpose of this study was to evaluate residents' understanding of biostatistics and interpretation of research results. A questionnaire previously used in internal medicine residents was modified to include oral and maxillofacial surgery (OMS) examples. The survey included sections to identify demographic and educational characteristics of residents, attitudes and confidence, and the primary outcome-knowledge of biostatistics. In 2009 an invitation to the Internet survey was sent to all 106 program directors in the United States, who were requested to forward it to their residents. One hundred twelve residents responded. The percentage of residents who had taken a course in epidemiology was 53%; biostatistics, 49%; and evidence-based dentistry, 65%. Conversely, 10% of OMS residents had taken none of these classes. Across the 6-item test of knowledge of statistical methods, the mean percentage of correct answers was 38% (SD, 22%). Nearly half of the residents (42%) could not correctly identify continuous, ordinal, or nominal variables. Only 21% correctly identified a case-control study, but 79% correctly identified that the purpose of blinding was to reduce bias. Only 46% correctly interpreted a clinically unimportant and statistically nonsignificant result. None of the demographic or experience factors of OMS residents were related to statistical knowledge. Overall, OMS resident knowledge was below that of internal medicine residents (P<.0001). However, OMS residents were overconfident in their claim to understand most statistical terms. OMS residents lack knowledge in biostatistics and the interpretation of research and are thus unprepared to interpret the results of published clinical research. Residency programs should include effective biostatistical training in their curricula to prepare residents in evidence-based dentistry. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Orthogonality measurements for multidimensional chromatography in three and higher dimensional separations.

PubMed

Schure, Mark R; Davis, Joe M

2017-11-10

Orthogonality metrics (OMs) for three and higher dimensional separations are proposed as extensions of previously developed OMs, which were used to evaluate the zone utilization of two-dimensional (2D) separations. These OMs include correlation coefficients, dimensionality, information theory metrics and convex-hull metrics. In a number of these cases, lower dimensional subspace metrics exist and can be readily calculated. The metrics are used to interpret previously generated experimental data. The experimental datasets are derived from Gilar's peptide data, now modified to be three dimensional (3D), and a comprehensive 3D chromatogram from Moore and Jorgenson. The Moore and Jorgenson chromatogram, which has 25 identifiable 3D volume elements or peaks, displayed good orthogonality values over all dimensions. However, OMs based on discretization of the 3D space changed substantially with changes in binning parameters. This example highlights the importance in higher dimensions of having an abundant number of retention times as data points, especially for methods that use discretization. The Gilar data, which in a previous study produced 21 2D datasets by the pairing of 7 one-dimensional separations, was reinterpreted to produce 35 3D datasets. These datasets show a number of interesting properties, one of which is that geometric and harmonic means of lower dimensional subspace (i.e., 2D) OMs correlate well with the higher dimensional (i.e., 3D) OMs. The space utilization of the Gilar 3D datasets was ranked using OMs, with the retention times of the datasets having the largest and smallest OMs presented as graphs. A discussion concerning the orthogonality of higher dimensional techniques is given with emphasis on molecular diversity in chromatographic separations. In the information theory work, an inconsistency is found in previous studies of orthogonality using the 2D metric often identified as %O. A new choice of metric is proposed, extended to higher dimensions, characterized by mixes of ordered and random retention times, and applied to the experimental datasets. In 2D, the new metric always equals or exceeds the original one. However, results from both the original and new methods are given. Copyright © 2017 Elsevier B.V. All rights reserved.

Screening and brief interventions for hazardous and harmful alcohol use in probation services: a cluster randomised controlled trial protocol

PubMed Central

2009-01-01

Background A large number of randomised controlled trials in health settings have consistently reported positive effects of brief intervention in terms of reductions in alcohol use. However, although alcohol misuse is common amongst offenders, there is limited evidence of alcohol brief interventions in the criminal justice field. This factorial pragmatic cluster randomised controlled trial with Offender Managers (OMs) as the unit of randomisation will evaluate the effectiveness and cost-effectiveness of different models of screening to identify hazardous and harmful drinkers in probation and different intensities of brief intervention to reduce excessive drinking in probation clients. Methods and design Ninety-six OMs from 9 probation areas across 3 English regions (the North East Region (n = 4) and London and the South East Regions (n = 5)) will be recruited. OMs will be randomly allocated to one of three intervention conditions: a client information leaflet control condition (n = 32 OMs); 5-minute simple structured advice (n = 32 OMs) and 20-minute brief lifestyle counselling delivered by an Alcohol Health Worker (n = 32 OMs). Randomisation will be stratified by probation area. To test the relative effectiveness of different screening methods all OMs will be randomised to either the Modified Single Item Screening Questionnaire (M-SASQ) or the Fast Alcohol Screening Test (FAST). There will be a minimum of 480 clients recruited into the trial. There will be an intention to treat analysis of study outcomes at 6 and 12 months post intervention. Analysis will include client measures (screening result, weekly alcohol consumption, alcohol-related problems, re-offending, public service use and quality of life) and implementation measures from OMs (the extent of screening and brief intervention beyond the minimum recruitment threshold will provide data on acceptability and feasibility of different models of brief intervention). We will also examine the practitioner and organisational factors associated with successful implementation. Discussion The trial will evaluate the impact of screening and brief alcohol intervention in routine probation work and therefore its findings will be highly relevant to probation teams and thus the criminal justice system in the UK. Ethical approval was given by Northern & Yorkshire REC Trial Registration number ISRCTN 19160244 PMID:19922618

Screening and brief interventions for hazardous and harmful alcohol use in probation services: a cluster randomised controlled trial protocol.

PubMed

Newbury-Birch, Dorothy; Bland, Martin; Cassidy, Paul; Coulton, Simon; Deluca, Paolo; Drummond, Colin; Gilvarry, Eilish; Godfrey, Christine; Heather, Nick; Kaner, Eileen; Myles, Judy; Oyefeso, Adenekan; Parrott, Steve; Perryman, Katherine; Phillips, Tom; Shenker, Don; Shepherd, Jonathan

2009-11-18

A large number of randomised controlled trials in health settings have consistently reported positive effects of brief intervention in terms of reductions in alcohol use. However, although alcohol misuse is common amongst offenders, there is limited evidence of alcohol brief interventions in the criminal justice field. This factorial pragmatic cluster randomised controlled trial with Offender Managers (OMs) as the unit of randomisation will evaluate the effectiveness and cost-effectiveness of different models of screening to identify hazardous and harmful drinkers in probation and different intensities of brief intervention to reduce excessive drinking in probation clients. Ninety-six OMs from 9 probation areas across 3 English regions (the North East Region (n = 4) and London and the South East Regions (n = 5)) will be recruited. OMs will be randomly allocated to one of three intervention conditions: a client information leaflet control condition (n = 32 OMs); 5-minute simple structured advice (n = 32 OMs) and 20-minute brief lifestyle counselling delivered by an Alcohol Health Worker (n = 32 OMs). Randomisation will be stratified by probation area. To test the relative effectiveness of different screening methods all OMs will be randomised to either the Modified Single Item Screening Questionnaire (M-SASQ) or the Fast Alcohol Screening Test (FAST). There will be a minimum of 480 clients recruited into the trial. There will be an intention to treat analysis of study outcomes at 6 and 12 months post intervention. Analysis will include client measures (screening result, weekly alcohol consumption, alcohol-related problems, re-offending, public service use and quality of life) and implementation measures from OMs (the extent of screening and brief intervention beyond the minimum recruitment threshold will provide data on acceptability and feasibility of different models of brief intervention). We will also examine the practitioner and organisational factors associated with successful implementation. The trial will evaluate the impact of screening and brief alcohol intervention in routine probation work and therefore its findings will be highly relevant to probation teams and thus the criminal justice system in the UK.Ethical approval was given by Northern & Yorkshire REC. ISRCTN 19160244.

Composites of cationic nanofibrillated cellulose and layered silicates: water vapor barrier and mechanical properties.

PubMed

Ho, Thao T T; Zimmermann, Tanja; Ohr, Steffen; Caseri, Walter R

2012-09-26

Composites of trimethylammonium-modified nanofibrillated cellulose and layered silicates (TMA-NFC/LS) were prepared by high-shear homogenization followed by pressure filtration and vacuum hot-pressing, which gave rise to particularly homogeneous dispersion of the silicate particles. Thirteen different clays and micas were employed. Water vapor barrier and mechanical properties (tensile strength, E-modulus, strain at break) of the composite films were investigated, considering the effects of layered silicate types and their concentration (in the range of 0 to 85 wt %). Good interactions between TMA-NFC and LS were obtained due to electrostatic attraction between cationic fibrils and anionic silicate layers, and even favored by high-shear homogenization process. Furthermore, oriented TMA-NFC/LS composite structure was achieved. Layered silicates exerted a pronounced influence on the water vapor barrier and mechanical properties; however, there was no common trend reflecting their types. The transport of water molecules through TMA-NFC/LS composites was studied considering both diffusion and adsorption mechanisms. As a result, diffusion pathways were proposed based on two new and one well-known models: the "native network", "covered fiber composite", and "fiber-brick composite" models. Importantly, it was found that the insertion of layered silicate particles did not improve automatically the barrier properties as indicated by the commonly used "fiber-brick composite" model. Mica R120 at a 50 wt % loading in composites with TMA-NFC matrix showed 30-fold improved water vapor permeability and 5-fold higher E-modulus compared to commercially used base paper.

Effect of type and content of modified montmorillonite on the structure and properties of bio-nanocomposite films based on soy protein isolate and montmorillonite

USDA-ARS?s Scientific Manuscript database

The non-biodegradable and non-renewable nature of plastic packaging has led to a renewed interest in packaging materials based on bio-nanocomposites (biopolymer matrix reinforced with nanoparticles such as layered silicates). Bio-nanocomposite films based on soy protein isolate (SPI) and modified mo...

Cosmological reconstruction and Om diagnostic analysis of Einstein-Aether theory

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

Pasqua, Antonio; Chattopadhyay, Surajit; Momeni, Davood

In this paper, we analyze the cosmological models in Einstein-Aether gravity, which is a modified theory of gravity in which a time-like vector field breaks the Lorentz symmetry. We use this formalism to analyse different cosmological models with different behavior of the scale factor. In this analysis, we use a certain functional dependence of the Dark Energy (DE) on the Hubble parameter H . It will be demonstrated that the Aether vector field has a non-trivial effect on these cosmological models. We also perform the Om diagnostic in Einstein-Aether gravity and we fit the parameters of the cosmological models usingmore » recent observational data.« less

Phospho-silicate and silicate layers modified by hydroxyapatite particles

NASA Astrophysics Data System (ADS)

Rokita, M.; Brożek, A.; Handke, M.

2005-06-01

Common used metal materials do not ensure good connection between an implant and biological neighbourhood. Covering implants by thin silicate or phosphate layers enable to improve biological properties of implants and create conditions for producing the non-concrete bonding between the implant and tissue. The project includes preparing silicate sols of different concentrations and proper (powder) fraction of synthetic as well as natural ox hydroxyapatite, depositing the sol mixed with hydroxyapatite onto the base material (metal, ceramic carbon) and heat treatment. Our work includes also preparation of phospho-silicate layers deposited onto different base materials using sol-gel method. Deposited sols were prepared regarding composition, concentration and layer heat treatment conditions. The prepared layers are examined to determine their phase composition (XRD, IR spectroscopy methods), density and continuity (scanning microscopy with EDX methods). Biological activity of layers was evaluated by means of estimation of their corrosive resistance in synthetic body fluids ('in vitro' method) and of bone cells growth on the layers surface. Introducing hydroxyapatite to the layer sol should improve connection between tissue and implant as well as limit the disadvantageous, corrosive influence of implant material (metal) on the tissue.

Quantitative analysis of major elements in silicate minerals and glasses by micro-PIXE

USGS Publications Warehouse

Campbell, J.L.; Czamanske, G.K.; MacDonald, L.; Teesdale, W.J.

1997-01-01

The Guelph micro-PIXE facility has been modified to accommodate a second Si(Li) X-ray detector which records the spectrum due to light major elements (11 ??? Z ??? 20) with no deleterious effects from scattered 3 MeV protons. Spectra have been recorded from 30 well-characterized materials, including a broad range of silicate minerals and both natural and synthetic glasses. Sodium is mobile in some of the glasses, but not in the studied mineral lattices. The mean value of the instrumental constant H for each of the elements Mg, Al, and Si in these materials is systematically 6-8% lower than the H-value measured for the pure metals. Normalization factors are derived which permit the matrix corrections requisite for trace-element measurements in silicates to be based upon pure metal standards for Mg, Al and Si, supplemented by well-established, silicate mineral standards for the elements Na, K and Ca. Rigorous comparisons of electron microprobe and micro-PIXE analyses for the entire, 30-sample suite demonstrate the ability of micro-PIXE to produce accurate analysis for the light major elements in silicates. ?? 1997 Elsevier Science B.V.

Reactive molecular simulation on the calcium silicate hydrates/polyethylene glycol composites

NASA Astrophysics Data System (ADS)

Zhou, Yang; Hou, Dongshuai; Jiang, Jinyang; She, Wei; Yu, Jiao

2017-11-01

Calcium silicate hydrates (C-S-H) may potentially exhibit extraordinary performance when modified by polymers, in which way the properties of cement-based materials can be improved from the genetic level. In this molecular dynamics simulation of the interaction between C-S-H and polyethylene glycol, apart from the H bond network connection in the interface, another chemical adsorption was observed. Calcium of C-S-H broke the Csbnd O bond of PEG and formed a new Casbnd C connection, which created a stronger link between the organic and inorganic phases.

Quantitative description of respiration processes in meso-eutrophic and eutrophic freshwater environments.

PubMed

Kiersztyn, Bartosz; Kauppinen, Elsi S; Kaliński, Tomasz; Chróst, Ryszard; Siuda, Waldemar

2018-06-01

We propose a modification of measurement methodology allowing the overall respiration rate (V Resp ) close to the in situ conditions; size of the labile, respirable organic matter pool (OM Resp ); and its turnover time (Tt) to be calculated. In addition to the respiration of dissolved substrates by free-living bacteria, the respiration of attached bacteria and other planktonic organisms is also taken into account. In case study we evaluated the modified, quantitative description of respiration processes in surface waters of lakes of different trophic status: mezzo-eutrophic and eutrophic. In both types of studied environments, V Resp oscillated between 1.0 μmol C l -1  h -1 and 3.0 μmol C l -1  h -1 , and the size of the OM Resp pool varied from 39.3 μM C to 828.7 μM C. Despite of higher OM Resp concentrations in eutrophic lakes, we found a lower susceptibility of OM to respiration processes in eutrophic than in meso-eutrophic lakes but similar V Resp in both types of lakes. We conclude that the proposed method allows a fast quantitative description of labile organic matter utilization by aerobic aquatic microorganisms. Copyright © 2018 Elsevier B.V. All rights reserved.

Sources, Ages, and Alteration of Organic Matter in Estuaries.

PubMed

Canuel, Elizabeth A; Hardison, Amber K

2016-01-01

Understanding the processes influencing the sources and fate of organic matter (OM) in estuaries is important for quantifying the contributions of carbon from land and rivers to the global carbon budget of the coastal ocean. Estuaries are sites of high OM production and processing, and understanding biogeochemical processes within these regions is key to quantifying organic carbon (Corg) budgets at the land-ocean margin. These regions provide vital ecological services, including nutrient filtration and protection from floods and storm surge, and provide habitat and nursery areas for numerous commercially important species. Human activities have modified estuarine systems over time, resulting in changes in the production, respiration, burial, and export of Corg. Corg in estuaries is derived from aquatic, terrigenous, and anthropogenic sources, with each source exhibiting a spectrum of ages and lability. The complex source and age characteristics of Corg in estuaries complicate our ability to trace OM along the river-estuary-coastal ocean continuum. This review focuses on the application of organic biomarkers and compound-specific isotope analyses to estuarine environments and on how these tools have enhanced our ability to discern natural sources of OM, trace their incorporation into food webs, and enhance understanding of the fate of Corg within estuaries and their adjacent waters.

Syntectic Reactions involving Limestones and Limestone-Derived Carbonatitic Melts in the Generation of some Peralkalic Magmas: Reflections on Reginald Daly's Insights 100 Years Later

NASA Astrophysics Data System (ADS)

Lentz, D.

2017-12-01

The theoretical analysis of how sedimentary limestones and marbles could melt as a result of infiltrative contact metasomatism associated with silicate magmas, enables reconsideration of the limestone syntectic (assimilation) hypothesis for the origin of some peralkalic rocks. Reginald Daly's syntectic model published in detail in early 1918 fell out of favor because experimental evidence from the early 1960's suggested; 1) that limestone assimilation would increase P(CO2) and cause solidification of the silicate intrusion, 2) that there is a thermal barrier between silica-saturated and undersaturated magmas that would inhibit extensive desilication of the magma, and 3) the endothermic decarbonation reactions would require heat via magmatic crystallization of near-solidus magmas. However, these concerns were not as critical for high-T mafic melts relative to more low-T silicic melts, although most subsequent researchers dismissed syntexis as isotopic arguments also seemed robust. However, skarn-related limestone melts can interact much more easily with silicate magma, resulting in calc-silicate-forming (endoskarn-like) limestone syntectic (desilication - calcification-magnesification processes) decarbonation reactions with compositional evolution into the silica-undersaturated field. If mafic in composition originally when syntectically modified, then the CO2-bearing derivative peralkalic melt may subsequently react with the dominant volume magma or fractionate separately into a more evolved composition. As well, an increase in P(CO2) within the modified silicate fraction coupled with compositional evolution to more silica-undersaturated compositions enhances the stability of the immiscible, extremely low viscosity carbonate melt fraction. In addition, dynamic interaction of these co-existing immiscible melts (analogous to the current hypothesis) would partition elements, as well as isotopic signatures, such that they would be virtually unrecognizable as having a crustal level syntectic origin, based on mass-balance principles and Rayleigh decarbonation isotopic equilibria, as they do in many infiltrative skarn systems. Essentially, this partly vindicates the basic premise of Daly's limestone syntectic hypothesis for the origin of some peralkalic igneous rocks.

Andic soils : mineralogical effect onto organic matter dynamics, organic matter effect onto mineral dynamics, or both?

NASA Astrophysics Data System (ADS)

Basile-Doelsch, Isabelle; Amundson, Ronald; Balesdent, Jérome; Borschneck, Daniel; Bottero, Jean-Yves; Colin, Fabrice; de Junet, Alexis; Doelsch, Emmanuel; Legros, Samuel; Levard, Clément; Masion, Armand; Meunier, Jean-Dominique; Rose, Jérôme

2014-05-01

From a strictly mineralogical point of view, weathering of volcanic glass produces secondary phases that are short range ordered alumino-silicates (SRO-AlSi). These are imogolite tubes (2 to 3 nm of diameter) and allophane supposedly spheres (3.5 to 5 nm). Their local structure is composed of a curved gibbsite Al layer and Si tetrahedra in the vacancies (Q0). Proto-imogolites have the same local structure but are roof-shape nanoparticles likely representing the precursors of imogolite and allophanes (Levard et al. 2010). These structures and sizes give to the SRO-AlSi large specific surfaces and high reactivities. In some natural sites, imogolites and allophanes are formed in large quantities. Aging of these phases may lead to the formation of more stable minerals (halloysite, kaolinite and gibbsite) (Torn et al 1997). In natural environments, when the weathering of volcanic glass is associated with the establishment of vegetation, the soils formed are generally andosols. These soils are particularly rich in organic matter (OM), which is explained by the high ability of SRO-AlSi mineral phases to form bonds with organic compounds. In a first order "bulk" approach, it is considered that these bonds strongly stabilize the organic compounds as their mean age can reach more than 10 kyrs in some studied sites (Basile-Doelsch et al. 2005; Torn et al. 1997). However, the structure of the mineral phases present in andosols deserves more attention. Traditionally, the presence in the SRO-AlSi andosols was shown by selective dissolution approaches by oxalate and pyrophosphate. Using spectroscopic methods, mineralogical analysis of SRO-AlSi in andosols samples showed that these mineral phases were neither imogolites nor allophanes as originally supposed, but only less organized structures remained in a state of proto-imogolites (Basile-Doelsch al. 2005 ; Levard et al., 2012). The presence of OM would have an inhibitory effect on the formation of secondary mineral phases, by blocking the crystal growth of SRO-AlSi. Conversely, the effect of minerals on the dynamics of organic compounds also deserves to be studied in greater detail. If the "bulk" approaches showed that proto-imogolites involve long-term stabilized OM, other approaches such as densimetric fractionation and C3/C4 chronosequences (Basile-Doelsch et al. 2007; De Junet et al. 2013) led us to consider a new model involving two types of organo-mineral interactions: (1) OM stabilized by strong bonds to proto-imogolite, leading to a slow OM turnover and (2) OM retained within the porosity of the 3D structure formed by the proto-imogolite (similar to a gel structure), leading to a faster OM turnover. Understanding the mechanisms of organo-mineral interactions in andosols will open new research directions for understanding the mechanisms of stabilization of OM in any type of soil (Bonnard et al. 2012). Basile-Doelsch et al., Geoderma, 137, 477-489, 2007. Basile-Doelsch et al., European Journal of Soil Science, 56, 689-703, 2005. Bonnard et al., European Journal of Soil Science, 63, 5, 625-636, 2012. de Junet, et al., Journal of Analytical and Applied Pyrolysis, 99, 92-10, 2013, Levard et al, Geoderma, 183-184, 100-108, 2012. Levard et al. Chemistry Of Materials, 22, 2466-2473, 2010 Torn et al. Nature, London, 389, 170-173, 1997.

Investigation of Physico-Chemical Properties of Sand-Lime Products Modified of Diabase Aggregate and Chalcedonite Meal

NASA Astrophysics Data System (ADS)

Dachowski, Ryszard; Komisarczyk, Katarzyna

2017-10-01

In the era of rapid development in the construction industry, particular attention is focused on harmless and natural materials. Some of the best materials for building masonry walls are sand-lime products. Silicates are obtained from a mixture of quartz, sand and a small amount of water. They emerge as a result of the hydrothermal treatment conducted under high pressure and at a temperature of app. 203 °C. Silicates were modified of different kinds of aggregates, glass or plastics, and the content of dry ingredients was changed because of this fact. The paper describes the studies where the combination of diabase aggregate and chalcedonite meal was used. Microstructure of the products was analyzed with the use of mercury intrusion porosimetry, SEM and XRD methods. Variable content of chalcedonite meal changes the internal structure and the physico-chemical properties.

Ion-Doped Silicate Bioceramic Coating of Ti-Based Implant

PubMed Central

Mohammadi, Hossein; Sepantafar, Mohammadmajid

2016-01-01

Titanium and its alloy are known as important load-bearing biomaterials. The major drawbacks of these metals are fibrous formation and low corrosion rate after implantation. The surface modification of biomedical implants through various methods such as plasma spray improves their osseointegration and clinical lifetime. Different materials have been already used as coatings on biomedical implant, including calcium phosphates and bioglass. However, these materials have been reported to have limited clinical success. The excellent bioactivity of calcium silicate (Ca-Si) has been also regarded as coating material. However, their high degradation rate and low mechanical strength limit their further coating application. Trace element modification of (Ca-Si) bioceramics is a promising method, which improves their mechanical strength and chemical stability. In this review, the potential of trace element-modified silicate coatings on better bone formation of titanium implant is investigated. PMID:26979401

Potential effect of fiddler crabs on organic matter distribution: A combined laboratory and field experimental approach

NASA Astrophysics Data System (ADS)

Natálio, Luís F.; Pardo, Juan C. F.; Machado, Glauco B. O.; Fortuna, Monique D.; Gallo, Deborah G.; Costa, Tânia M.

2017-01-01

Bioturbators play a key role in estuarine environments by modifying the availability of soil elements, which in turn may affect other organisms. Despite the importance of bioturbators, few studies have combined both field and laboratory experiments to explore the effects of bioturbators on estuarine soils. Herein, we assessed the bioturbation potential of fiddler crabs Leptuca leptodactyla and Leptuca uruguayensis in laboratory and field experiments, respectively. We evaluated whether the presence of fiddler crabs resulted in vertical transport of sediment, thereby altering organic matter (OM) distribution. Under laboratory conditions, the burrowing activity by L. leptodactyla increased the OM content in sediment surface. In the long-term field experiment with areas of inclusion and exclusion of L. uruguayensis, we did not observe influence of this fiddler crab in the vertical distribution of OM. Based on our results, we suggest that small fiddler crabs, such as the species used in these experiments, are potentially capable of alter their environment by transporting sediment and OM but such effects may be masked by environmental drivers and spatial heterogeneity under natural conditions. This phenomenon may be related to the small size of these species, which affects how much sediment is transported, along with the way OM interacts with biogeochemical and physical processes. Therefore, the net effect of these burrowing organisms is likely to be the result of a complex interaction with other environmental factors. In this sense, we highlight the importance of performing simultaneous field and laboratory experiments in order to better understanding the role of burrowing animals as bioturbators.

Synchrotron x-ray spectroscopy of EuHN O3 aqueous solutions at high temperatures and pressures and Nb-bearing silicate melt phases coexisting with hydrothermal fluids using a modified hydrothermal diamond anvil cell and rail assembly

USGS Publications Warehouse

Mayanovic, Robert A.; Anderson, Alan J.; Bassett, William A.; Chou, I.-Ming

2007-01-01

A modified hydrothermal diamond anvil cell (HDAC) rail assembly has been constructed for making synchrotron x-ray absorption spectroscopy, x-ray fluorescence, and x-ray mapping measurements on fluids or solid phases in contact with hydrothermal fluids up to ???900??C and 700 MPa. The diamond anvils of the HDAC are modified by laser milling grooves or holes, for the reduction of attenuation of incident and fluorescent x rays and sample cavities. The modified HDAC rail assembly has flexibility in design for measurement of light elements at low concentrations or heavy elements at trace levels in the sample and the capability to probe minute individual phases of a multiphase fluid-based system using focused x-ray microbeam. The supporting rail allows for uniform translation of the HDAC, rotation and tilt stages, and a focusing mirror, which is used to illuminate the sample for visual observation using a microscope, relative to the direction of the incident x-ray beam. A structure study of Eu(III) aqua ion behavior in high-temperature aqueous solutions and a study of Nb partitioning and coordination in a silicate melt in contact with a hydrothermal fluid are described as applications utilizing the modified HDAC rail assembly. ?? 2007 American Institute of Physics.

Design of Hybrid Solid Polymer Electrolytes: Structure and Properties

NASA Technical Reports Server (NTRS)

Bronstein, Lyudmila M.; Karlinsey, Robert L.; Ritter, Kyle; Joo, Chan Gyu; Stein, Barry; Zwanziger, Josef W.

2003-01-01

This paper reports synthesis, structure, and properties of novel hybrid solid polymer electrolytes (SPE's) consisting of organically modified aluminosilica (OM-ALSi), formed within a poly(ethylene oxide)-in-salt (Li triflate) phase. To alter the structure and properties we fused functionalized silanes containing poly(ethylene oxide) (PEO) tails or CN groups.

Nitrogen removal performance of anaerobic ammonia oxidation (ANAMMOX) in presence of organic matter.

PubMed

Zhu, Weiqiang; Zhang, Peiyu; Yu, Deshuang; Dong, Huiyu; Li, Jin

2017-06-01

A sequencing batch reactor (SBR) was used to test the nitrogen removal performance of anaerobic ammonium oxidation (ANAMMOX) in presence of organic matter. Mesophilic operation (30 ± 0.5 °C) was performed with influent pH 7.5. The results showed, independent of organic matter species, ANAMMOX reaction was promoted when COD was lower than 80 mg/L. However, specific ANAMMOX activity decreased with increasing organic matter content. Ammonium removal efficiency decreased to 80% when COD of sodium succinate, sodium potassium tartrate, peptone and lactose were 192.5, 210, 225 and 325 mg/L, respectively. The stoichiometry ratio resulting from different OM differed largely and R 1 could be as an indicator for OM inhibition. When COD concentration was 240 mg/L, the loss of SAA resulting from lactose, peptone, sodium potassium tartrate and sodium succinate were 28, 36, 50 and 55%, respectively. Sodium succinate had the highest inhibitory effect on SAA. When ANAMMOX process was used to treat wastewater containing OM, the modified Logistic model could be employed to predict the NRE max .

Distinct effects of Broncho-Vaxom (OM-85 BV) on gp130 binding cytokines

PubMed Central

Roth, M; Block, L

2000-01-01

BACKGROUND—Broncho-Vaxom (OM-85 BV) is known to support respiratory tract resistance to bacterial infections. In vivo and in vitro studies in animals and humans have shown that the action of the drug is based on the modulation of the host immune response, and it has been found to upregulate interferon γ (IFN-γ) and interleukin (IL)-2, IL-6, and IL-8. These immunomodulatory effects of the compound may explain its stimulation on T helper cells and natural killer cells. Following earlier findings that OM-85 BV induces the synthesis of IL-6, a study was undertaken to investigate its possible effect on other gp130 binding cytokines including IL-11, IL-12, leukaemia inhibitory factor (LIF), oncostatin M (OSM), and ciliary neutrophil factor (CNTF). Its modulation of the corresponding receptors of the above mentioned cytokines and of the signal transducer gp130 in human pulmonary fibroblasts and peripheral blood lymphocytes was also studied.
METHODS—Transcription of cytokines was assessed by Northern blot analysis. Secretion of cytokines was analysed using commercially available enzyme linked immunosorbent assay kits. Cytokine receptors and gp130 proteins were determined by Western blot analysis.
RESULTS—OM-85 BV increased the expression of IL-11 in human lung fibroblasts, but not in lymphocytes, in a dose and time dependent manner by maximal fivefold within 20 hours. The compound inhibited serum induced IL-12 expression in peripheral blood lymphocytes but did not induce OSM, LIF, or CNTF at any concentration. In lung fibroblasts the expression of the IL-6 receptor was enhanced fourfold at a concentration of 10 µg/ml OM-85 BV while that of the IL-11 receptor was not altered. In peripheral blood lymphocytes LIF receptor α expression was downregulated in the presence of 10 µg/ml OM-85 BV. At a concentration of 10 µg/ml OM-85 BV enhanced gp130 gene transcription fivefold and increased gp130 protein accumulation in cell membranes by 2.5times.
CONCLUSION—In vitro OM-85 BV exerts immunomodulatory action via modulation of the signal transducer gp130 and gp130 binding cytokines. The increase of IL-6 and IL-11 may explain enhanced T and B cell activity, immunoglobulin synthesis, and IgM to IgG switch. Suppression of IL-12 and LIF receptor-α further contributes to organ protection. With regard to gp130 mediated signalling of the investigated cytokines, OM-85 BV modifies the host immune response towards an increased sensitisation of cells to gp130 binding proteins.

 PMID:10899245

One molecule of ionic liquid and tert-alcohol on a polystyrene-support as catalysts for efficient nucleophilic substitution including fluorination.

PubMed

Shinde, Sandip S; Patil, Sunil N

2014-12-07

The tert-alcohol and ionic liquid solvents in one molecule [mim-(t)OH][OMs] was immobilized on polystyrene and reported to be a highly efficient catalyst in aliphatic nucleophilic substitution using alkali metal salts. Herein, we investigated the catalytic activity of a new structurally modified polymer-supported tert-alcohol functionalized imidazolium salt catalyst in nucleophilic substitution of 2-(3-methanesulfonyloxypropyoxy)naphthalene as a model substrate with various metal nucleophiles. The tert-alcohol moiety of the ionic liquid with a hexyl chain distance from polystyrene had a better catalytic activity compared to the other resin which lacked an alkyl linker and tert-alcohol moiety. We found that the maximum [mim-(t)OH][OMs] loading had the best catalytic efficacy among the tested polystyrene-based ionic liquids (PSILs) in nucleophilic fluorination. The catalytic efficiency of the PS[him-(t)OH][OMs] as a phase transfer catalyst (PTC) was determined by carrying out various nucleophilic substitutions using the corresponding alkali metal salts from the third to sixth periodic in CH3CN or tert-BuOH media. The scope of this protocol with primary and secondary polar substrates containing many heteroatoms is also reported. This PS[him-(t)OH][OMs] catalyst not only enhances the reactivity of alkali metal salts and reduces the formation of by-products but also affords high yield with easy isolation.

Tip-induced nanoreactor for silicate

NASA Astrophysics Data System (ADS)

Gao, Ming; Ma, Liran; Liang, Yong; Gao, Yuan; Luo, Jianbin

2015-09-01

Nanoscale scientific issues have attracted an increasing amount of research interest due to their specific size-effect and novel structure-property. From macro to nano, materials present some unique chemical reactivity that bulk materials do not own. Here we introduce a facile method to generate silicate with nanoscale control based on the establishment of a confined space between a meso/nanoscale tungsten tip and a smooth silica/silicon substrate. During the process, local water-like droplets deposition can be obviously observed in the confinement between the Si/SiO2 surfaces and the KOH-modified tungsten tip. By the combination of in-situ optical microscopy and Raman spectroscopy, we were able to take a deep insight of both the product composition and the underlying mechanism of such phenomena. It was indicated that such nanoreactor for silicate could be quite efficient as a result of the local capillarity and electric field effect, with implications at both nano and meso scales.

Tip-induced nanoreactor for silicate.

PubMed

Gao, Ming; Ma, Liran; Liang, Yong; Gao, Yuan; Luo, Jianbin

2015-09-14

Nanoscale scientific issues have attracted an increasing amount of research interest due to their specific size-effect and novel structure-property. From macro to nano, materials present some unique chemical reactivity that bulk materials do not own. Here we introduce a facile method to generate silicate with nanoscale control based on the establishment of a confined space between a meso/nanoscale tungsten tip and a smooth silica/silicon substrate. During the process, local water-like droplets deposition can be obviously observed in the confinement between the Si/SiO2 surfaces and the KOH-modified tungsten tip. By the combination of in-situ optical microscopy and Raman spectroscopy, we were able to take a deep insight of both the product composition and the underlying mechanism of such phenomena. It was indicated that such nanoreactor for silicate could be quite efficient as a result of the local capillarity and electric field effect, with implications at both nano and meso scales.

Tip-induced nanoreactor for silicate

PubMed Central

Gao, Ming; Ma, Liran; Liang, Yong; Gao, Yuan; Luo, Jianbin

2015-01-01

Nanoscale scientific issues have attracted an increasing amount of research interest due to their specific size-effect and novel structure-property. From macro to nano, materials present some unique chemical reactivity that bulk materials do not own. Here we introduce a facile method to generate silicate with nanoscale control based on the establishment of a confined space between a meso/nanoscale tungsten tip and a smooth silica/silicon substrate. During the process, local water-like droplets deposition can be obviously observed in the confinement between the Si/SiO2 surfaces and the KOH-modified tungsten tip. By the combination of in-situ optical microscopy and Raman spectroscopy, we were able to take a deep insight of both the product composition and the underlying mechanism of such phenomena. It was indicated that such nanoreactor for silicate could be quite efficient as a result of the local capillarity and electric field effect, with implications at both nano and meso scales. PMID:26364882

Al Speciation in Silicate Melts: AlV a new Network Former?

NASA Astrophysics Data System (ADS)

Neuville, D. R.; Florian, P.; de Ligny, D.; Montouillout, V.; Massiot, D.

2009-05-01

The first human glasses were made 3500 BC. It was essentially sodo-lime silicate glass. To improve the chemical resistance, the thermal properties and increase the viscosity it is interesting to add aluminum in these silicates. But what is the speciation of the aluminum and how it varies according to the chemical composition and to the temperature? The aluminum appears essentially in four or five fold coordination in glasses and melts melted. The proportion of [5]Al varies according to the alkaline or to the earth-alkaline content and to the temperature. We shall present in a first part the influence of the network-modifier on the proportion of [5]Al and then we shall present some new results of absorption of high-temperature using NMR and XANES spectroscopy at the Al K-edge. Finally, from glass transition temperature measurements we propose to explain that [5]Al can be a new network former.

Modifying the Clinical Outcomes in Routine Evaluation Measure for Use with People Who Have a Learning Disability

ERIC Educational Resources Information Center

Marshall, Keith; Willoughby-Booth, Simon

2007-01-01

There are few reliable self-report measures suitable for people with a learning disability in reporting psychological distress. This study examines the modification of the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM), exploring its reliability, using two different presentation styles. One style included a sequencing task then…

Dexamethasone, Intravenous Immunoglobulin, and Rituximab Combination Immunotherapy for Pediatric Opsoclonus-Myoclonus Syndrome.

PubMed

Pranzatelli, Michael R; Tate, Elizabeth D

2017-08-01

Although pulse-dose dexamethasone is increasingly favored for treating pediatric opsoclonus-myoclonus syndrome (OMS), and multimodal immunotherapy is associated with improved clinical response, there have been no neuroimmunologic studies of dexamethasone-based multimodal disease-modifying therapy. In this observational retrospective study, 19 children with OMS (with or without associated neuroblastoma) underwent multibiomarker evaluation for neuroinflammation. Nine children of varying OMS severity, duration, and treatment status were treated empirically with pulse dexamethasone, intravenous immunoglobulin (IVIg), and rituximab combination immunotherapy (DEXIR-CI). Another 10 children on dexamethasone alone or with IVIg at initial evaluation only provided a comparison group. Motor severity (total score) was scored rater-blinded via videotapes using the validated OMS Evaluation Scale. DEXIR-CI was associated with a 69% reduction in group total score (P = 0.004) and was clinically well tolerated. Patients given the dexamethasone combination exhibited significantly lowered B cell frequencies in cerebrospinal fluid (-94%) and blood (-76%), normalizing the cerebrospinal fluid B cell percentage. The number of patients with positive inflammatory markers dropped 87% (P = 0.002) as did the number of markers. Cerebrospinal fluid oligoclonal bands were positive in four of nine pretreatment patients but zero of six post-treatment patients. In the comparison group, partial response to dexamethasone alone or with IVIg was associated with multiple positive markers for neuroinflammation despite an average of seven months of treatment. Multimechanistic dexamethasone-based combination immunotherapy increases the therapeutic armamentarium for OMS, providing a viable option for less severely affected individuals. Partial response to dexamethasone with or without IVIg is indicative of ongoing neuroinflammation and should be treated promptly and accordingly. Copyright © 2017 Elsevier Inc. All rights reserved.

Modified SBA-15 as the carrier for metoprolol and papaverine: Adsorption and release study

NASA Astrophysics Data System (ADS)

Moritz, MichaŁ; łaniecki, Marek

2011-07-01

A series of modified SBA-15 materials were applied in drug delivery systems. The internal surface of siliceous hexagonal structure of SBA-15 was modified with different amount of (3-mercaptopropyl)trimethoxysilane (MPTMS) and oxidized in the presence of hydrogen peroxide. The sulfonated material was loaded with metoprolol tartrate or papaverine hydrochloride. Both drugs indicated strong chemical interaction with modified mesoporous surface. The characteristic of the obtained materials was performed with XRD and DRUV-vis spectrometry, themogravimetry and nitrogen adsorption (BET) measurements. The obtained results show that modification of the mesoporous materials leads towards significant decrease of the drug delivery rate.

Preparation, characterization and properties of polymer-layered silicate nanocomposites

NASA Astrophysics Data System (ADS)

Fonseca, Claudia Alencar

Nanocomposites are a relatively new class of composites, that in the polymer area typically consist of particle-filled polymers where at least one dimension of the dispersed particles is in the nanometer range. Amongst all potential nanocomposite precursors, those based on clay and layered silicates have been more widely investigated. These nanocomposites exhibit markedly improved mechanical, thermal, optical and physico-chemical properties when compared to conventional (microscale) composites. In the present work, properties of nanocomposites of Ethylene Methacrylic Acid copolymers and organically modified Montmorillonite formed from the melt was investigated. Nanocomposites of Poly(vinyl alcohol) and Montmorillonite formed from solution was also studied.

Autoclaved Sand-Lime Products with a Polypropylene Mesh

NASA Astrophysics Data System (ADS)

Kostrzewa, Paulina; Stępień, Anna

2017-10-01

The paper presents the results of the research on modifications of silicate bricks with a polypropylene mesh and their influence on physical, mechanical and microstructural properties of such bricks. The main goal of the paper was to determine effects of the polypropylene mesh on sand-lime product parameters. The analysis has focused on compressive strength, water absorption, bulk density and structural features of the material. The obtained product is characterized by improved basic performance characteristics compared to traditional silicate products. Using the polypropylene mesh increased compressive strength by 25% while decreasing the product density. The modified products retain their form and do not disintegrate after losing their bearing capacity.

Barrier and Mechanical Properties of Starch-Clay Nanocomposite Films

USDA-ARS?s Scientific Manuscript database

The poor barrier and mechanical properties of biopolymer-based food packaging can potentially be enhanced by the use of layered silicates (nanoclay) to produce nanocomposites. In this study, starch-clay nano-composites were synthesized by a melt extrusion method. Natural (MMT) and organically modifi...

Diffractive optics development using a modified stack-and-draw technique.

PubMed

Pniewski, Jacek; Kasztelanic, Rafal; Nowosielski, Jedrzej M; Filipkowski, Adam; Piechal, Bernard; Waddie, Andrew J; Pysz, Dariusz; Kujawa, Ireneusz; Stepien, Ryszard; Taghizadeh, Mohammad R; Buczynski, Ryszard

2016-06-20

We present a novel method for the development of diffractive optical elements (DOEs). Unlike standard surface relief DOEs, the phase shift is introduced through a refractive index variation achieved by using different types of glass. For the fabrication of DOEs we use a modified stack-and-draw technique, originally developed for the fabrication of photonic crystal fibers, resulting in a completely flat element that is easy to integrate with other optical components. A proof-of-concept demonstration of the method is presented-a two-dimensional binary optical phase grating in the form of a square chessboard with a pixel size of 5 μm. Two types of glass are used: low refractive index silicate glass NC21 and high refractive index lead-silicate glass F2. The measured diffraction characteristics of the fabricated component are presented and it is shown numerically and experimentally that such a DOE can be used as a fiber interconnector that couples light from a small-core fiber into the several cores of a multicore fiber.

Alkali-Activated Aluminium-Silicate Composites as Insulation Materials for Industrial Application

NASA Astrophysics Data System (ADS)

Dembovska, L.; Bajare, D.; Pundiene, I.; Bumanis, G.

2015-11-01

The article reports on the study of thermal stability of alkali-activated aluminium- silicate composites (ASC) at temperature 800-1100°C. ASC were prepared by using calcined kaolinite clay, aluminium scrap recycling waste, lead-silicate glass waste and quartz sand. As alkali activator, commercial sodium silicate solution modified with an addition of sodium hydroxide was used. The obtained alkali activation solution had silica modulus Ms=1.67. Components of aluminium scrap recycling waste (aluminium nitride (AlN) and iron sulphite (FeSO3)) react in the alkali media and create gases - ammonia and sulphur dioxide, which provide the porous structure of the material [1]. Changes in the chemical composition of ASC during heating were identified and quantitatively analysed by using DTA/TG, dimension changes during the heating process were determined by using HTOM, pore microstructure was examined by SEM, and mineralogical composition of ASC was determined by XRD. The density of ASC was measured in accordance with EN 1097-7. ASC with density around 560 kg/m3 and heat resistance up to 1100°C with shrinkage less than 5% were obtained. The intended use of this material is the application as an insulation material for industrial purposes at elevated temperatures.

High-performance polymer/layered silicate nanocomposites

NASA Astrophysics Data System (ADS)

Heidecker, Matthew J.

High-performance layered-silicate nanocomposites of Polycarbonate (PC), poly(ethylene terephthalate) (PET), and their blends were produced via conventional melt-blending techniques. The focus of this thesis was on the fundamentals of dispersion, control of thermal stability, maintenance of melt-blending processing conditions, and on optimization of the composites' mechanical properties via the design of controlled and thermodynamically favorable nano-filler dispersions within the polymer matrices. PET and PC require high temperatures for melt-processing, rendering impractical the use of conventional/commercial organically-modified layered-silicates, since the thermal degradation temperatures of their ammonium surfactants lies below the typical processing temperatures. Thus, different surfactant chemistries must be employed in order to develop melt-processable nanocomposites, also accounting for polymer matrix degradation due to water (PET) or amine compounds (PC). Novel high thermal-stability surfactants were developed and employed in montmorillonite nanocomposites of PET, PC, and PC/PET blends, and were compared to the respective nanocomposites based on conventional quaternary-ammonium modified montmorillonites. Favorable dispersion was achieved in all cases, however, the overall material behavior -- i.e., the combination of crystallization, mechanical properties, and thermal degradation -- was better for the nanocomposites based on the thermally-stable surfactant fillers. Studies were also done to trace, and ultimately limit, the matrix degradation of Polycarbonate/montmorillonite nanocomposites, through varying the montmorillonite surfactant chemistry, processing conditions, and processing additives. Molecular weight degradation was, maybe surprisingly, better controlled in the conventional quaternary ammonium based nanocomposites -- even though the thermal stability of the organically modified montmorillonites was in most cases the lowest. Dependence of the resultant nanocomposites' mechanical properties on the preferential alignment of the montmorillonite nano-platelet was also evaluated. Highly aligned filler platelets did not result in an additional enhancement in mechanical properties. PC/PET blends and their respective PC/PET/montmorillonite nanocomposites were synthesized and compared. The dispersion of the organically modified nano-fillers in the PC/PET blends was controlled via thermodynamic considerations, realized through proper surfactant choice: Nanocomposites in which the layered silicate was preferentially sequestered in the PET phase were designed and synthesized. This preferential dispersion of the nano-filler in the PET phase of the PC/PET blend was insensitive to processing conditions, including approaches employing a master-batch (filler concentrate); regardless of the master-batch matrix, both PC and PET were employed, thermodynamics drove the layered silicate to preferentially migrate to the PET phase of the PC/PET blend. In a second approach, the development of a nanocomposite with controlled PC/PET compatibilization near the montmorillonite platelets, in absence of appreciable transesterification reactions, led to the formation of very high performance nanocomposites. These latter systems, point to an exciting new avenue of future considerations for nanocomposite blends with selective nano-filler dispersions, where performance can be tailored via the controlled preferential dispersion of nano-fillers in one phase, or by filler-induced polymer compatibilization.

Soil respiration and carbon responses to logging debris and competing vegetation

Treesearch

Robert A. Slesak; Stephen H. Schoenholtz; Timothy B. Harrington

2010-01-01

Management practices following forest harvesting that modify organic matter (OM) inputs and influence changes in the soil environment have the potential to alter soil C pools, but there is still much uncertainty regarding how these practices influence soil C flux. We examined the influence of varying amounts of logging-debris retention (0, 40, and 80% coverage) and...

Identification of ethanol tolerant outer membrane proteome reveals OmpC-dependent mechanism in a manner of EnvZ/OmpR regulation in Escherichia coli.

PubMed

Zhang, Dan-Feng; Ye, Jin-Zhou; Dai, Hong-Hou; Lin, Xiang-Min; Li, Hui; Peng, Xuan-Xian

2018-05-15

Ethanol is an efficient disinfectant, but long-term and wide usage of ethanol leads to microbial tolerance. Bacteria with the tolerance are widely identified. However, mechanisms of the tolerance are not elucidated. To explore the mechanisms of outer membrane (OM) proteins underlying ethanol tolerance in bacteria, functional proteomic methodologies were utilized to characterize OM proteins of E. coli suddenly exposed to 3.125% ethanol. Of eleven proteins altered significantly, seven were OM proteins, in which LamB, FadL and OmpC were up-regulated, and OmpT, OmpF, Tsx and OmpA were down-regulated. The alterations were validated using Western blot. Then, functional characterization of the altered abundance of OM proteins was investigated in gene-deleted and gene-complemented mutants cultured in 1.56-6.25% ethanol. Higher inhibiting rate was detected in ΔompC than ΔlamB and ΔompA, but no difference was found between Δtsx, ΔompF, ΔfadL or ΔompT and control. Furthermore, EnvZ/OmpR two-component signal transduction system, which regulates OmpC and OmpF expression, was determined to participate in the tolerance. Finally, our results show that absence of envZ, ompR or ompC and ompA led to elevated and reduced intracellular ethanol, respectively. These findings indicate EnvZ-dependent phosphotransfer signaling pathway of the OmpR-mediated expression of OmpC plays a crucial role in ethanol tolerance. Ethanol tolerance is an adaptation strategy of bacteria. In the present study, we used the proteomic approaches involving 2-DE and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) to determined outer membrane (OM) protein changes in E. coli K-12 after 2 h of 1/2 MIC of ethanol exposure. Under ethanol stress, seven differential OM proteins were found, which were validated by Western blot. Functions of these seven OM proteins were compared using their genetically modified strains. Furthermore, the role of EnvZ/OmpR two-component signal transduction system was identified in ethanol tolerance of E. coli. Finally, Loss of ompC, envZ or ompR increases intracellular ethanol, while absence of ompA reduces reversal effect. This is the first report of OM proteomics in E. coli exposed to ethanol. Our findings reveal an unknown OmpC-dependent mechanism of ethanol tolerance in a manner of EnvZ/OmpR regulation. Copyright © 2018 Elsevier B.V. All rights reserved.

Analysis of H2O in silicate glass using attenuated total reflectance (ATR) micro-FTIR spectroscopy

USGS Publications Warehouse

Lowenstern, Jacob B.; Pitcher, Bradley W.

2013-01-01

We present a calibration for attenuated total reflectance (ATR) micro-FTIR for analysis of H2O in hydrous glass. A Ge ATR accessory was used to measure evanescent wave absorption by H2O within hydrous rhyolite and other standards. Absorbance at 3450 cm−1 (representing total H2O or H2Ot) and 1630 cm−1 (molecular H2O or H2Om) showed high correlation with measured H2O in the glasses as determined by transmission FTIR spectroscopy and manometry. For rhyolite, wt%H2O=245(±9)×A3450-0.22(±0.03) and wt%H2Om=235(±11)×A1630-0.20(±0.03) where A3450 and A1630 represent the ATR absorption at the relevant infrared wavelengths. The calibration permits determination of volatiles in singly polished glass samples with spot size down to ~5 μm (for H2O-rich samples) and detection limits of ~0.1 wt% H2O. Basaltic, basaltic andesite and dacitic glasses of known H2O concentrations fall along a density-adjusted calibration, indicating that ATR is relatively insensitive to glass composition, at least for calc-alkaline glasses. The following equation allows quantification of H2O in silicate glasses that range in composition from basalt to rhyolite: wt%H2O=(ω×A3450/ρ)+b where ω = 550 ± 21, b = −0.19 ± 0.03, ρ = density, in g/cm3, and A3450 is the ATR absorbance at 3450 cm−1. The ATR micro-FTIR technique is less sensitive than transmission FTIR, but requires only a singly polished sample for quantitative results, thus minimizing time for sample preparation. Compared with specular reflectance, it is more sensitive and better suited for imaging of H2O variations in heterogeneous samples such as melt inclusions. One drawback is that the technique can damage fragile samples and we therefore recommend mounting of unknowns in epoxy prior to polishing. Our calibration should hold for any Ge ATR crystals with the same incident angle (31°). Use of a different crystal type or geometry would require measurement of several H2O-bearing standards to provide a crystal-specific calibration.

Investigations of the 1 KHZ Sound Absorption in Sea Water.

DTIC Science & Technology

1983-01-15

York, 465 pages. Seward, T. M. (1974) Determination of the first ionization constant of silicic acid from quartz solubility in borate buffer...attenuation coefficient. J. Acoust. Soc. Am. 42, 270-271. Uppstrom, L (1968) A modified method for the determination of boron with curcumin and a simplified

Modified carbon fibers to improve composite properties. [sizing fibers for reduced electrical conductivity and adhesion during combustion

NASA Technical Reports Server (NTRS)

Shepler, R. E.

1979-01-01

Thin coatings, 5 to 10 wt. percent, were applied to PAN-based carbon fibers. These coatings were intended to make the carbon fibers less electrically conductive or to cause fibers to stick together when a carbon fiber/epoxy composite burned. The effectiveness of the coatings in these regards was evaluated in burn tests with a test rig designed to simulate burning, impact and wind conditions which might release carbon fibers. The effect of the coatings on fiber and composite properties and handling was also investigated. Attempts at sizing carbon fibers with silicon dioxide, silicon carbide and boron nitride meet with varying degrees of success; however, none of these materials provided an electrically nonconductive coating. Coatings intended to stick carbon fibers together after a composite burned were sodium silicate, silica gel, ethyl silicate, boric acid and ammonium borate. Of these, only the sodium silicate and silica gel provided any sticking together of fibers. The amount of sticking was insufficient to achieve the desired objectives.

Wastewater reuse in liquid sodium silicate manufacturing in alexandria, egypt.

PubMed

Ismail, Gaber A; Abd El-Salam, Magda M; Arafa, Anwar K

2009-01-01

Soluble sodium silicates (waterglass) are liquids containing dissolved glass which have some water like properties. They are widely used in industry as sealants, binders, deflocculants, emulsifiers and buffers. Their most common applications in Egypt are in the pulp and paper industry (where they improve the brightness and efficiency of peroxide bleaching) and the detergent industry, in which they improve the action of the detergent and lower the viscosity of liquid soaps. The survey results showed that the production was carried out batch-wise, in an autoclave (dissolver). Sodium silicate in the state of crushed glass was charged in an autoclave (dissolver) with sodium hydroxide and water. The product is filtered through a press. The left over sludge (mud and silicates impurities) is emptied into the local sewer system. Also, sludge (silica gel) was discharged from the neutralization process of the generated alkaline wastewater and consequently clogging the sewerage system. So this study was carried out to modify the current wastewater management system which eliminates sludge formation, the discharge of higher pH wastewater to the sewer system, and to assess its environmental and economic benefits. To assess the characteristics of wastewater to be reused, physico-chemical parameters of 12 samples were tested using standard methods. The survey results showed that a total capacity of the selected enterprise was 540 tons of liquid sodium silicates monthly. The total amount of wastewater being discharged was 335 m3/month. Reusing of wastewater as feed autoclave water reduced water consumption of 32.1% and reduced wastewater discharge/month that constitutes 89.6% as well as saving in final product of 6 ton/month. It was concluded that reusing of wastewater generated from liquid sodium silicate manufacturing process resulted in cheaper and environmental-friendly product.

Formulation and characterization of a compacted multiparticulate system for modified release of water-soluble drugs--part 1--acetaminophen.

PubMed

Cantor, Stuart L; Hoag, Stephen W; Augsburger, Larry L

2009-03-01

The aim of this study was to characterize and evaluate a modified release, multiparticulate tablet formulation consisting of placebo beads and drug-loaded beads. Acetaminophen (APAP) bead formulations containing ethylcellulose (EC) from 40-60% and placebo beads containing 30% calcium silicate and prepared using 0-20% alcohol were developed using extrusion-spheronization and studied using a central composite experimental design. Particle size and true density of beads were measured. Segregation testing was performed using the novel ASTM D6940-04 method on a 50:50 blend of uncoated APAP beads (60%EC) : calcium silicate placebo beads (10% alcohol). Tablets were prepared using an instrumented Stokes-B2 rotary tablet press and evaluated for crushing strength and dissolution rate. Compared with drug beads (60%EC), placebo beads (10% alcohol) were smaller but had higher true densities: 864.8 mum and 1.27 g/cm(3), and 787.1 mum and 1.73 g/cm(3), respectively. Segregation testing revealed that there was approximately a 20% difference in drug content (as measured by the coefficient of variation) between initial and final blend samples. Although calcium silicate-based placebo beads were shown to be ineffective cushioning agents in blends with Surelease(R)-coated APAP beads, they were found to be very compactibile when used alone and gave tablet crushing strength values between 14 and 17 kP. The EC in the APAP bead matrix minimally suppressed the drug release from uncoated beads (t(100%) = 2 h). However, while tablets containing placebo beads reformulated with glycerol monostearate (GMS) showed a slower release rate (t(60%)= 5 h) compared with calcium silicate-based placebos, some coating damage ( approximately 30%) still occurred on compression as release was faster than coated APAP beads alone. While tablets containing coated drug beads can be produced with practical crushing strengths (>8 kP) and low compression pressures (10-35 MPa), dissolution studies revealed that calcium silicate-based placebos are ineffective as cushioning agents. Blend segregation was likely observed due to the particle size and the density differences between APAP beads and calcium silicate-based placebo beads; placebo bead percolation can perhaps be minimized by increasing their size during the extrusion-spheronization process. The GMS- based placebos offer greater promise as cushioning agents for compacted, coated drug beads; however, this requires an optimized compression pressure range and drug bead : placebo bead ratio (i.e., 50:50).

Na/Ca Intermixing around Silicate and Phosphate Groups in Bioactive Phosphosilicate Glasses Revealed by Heteronuclear Solid-State NMR and Molecular Dynamics Simulations.

PubMed

Mathew, Renny; Stevensson, Baltzar; Edén, Mattias

2015-04-30

We characterize the intermixing of network-modifying Na(+)/Ca(2+) ions around the silicate (QSi(n)) and phosphate (QP(n)) tetrahedra in a series of 16 Na2O–CaO–SiO2–P2O5 glasses, whose P content and silicate network connectivity were varied independently. The set includes both bioactive and bioinactive compositions and also encompasses two soda-lime-silicate members devoid of P, as well as two CaO–SiO2 glasses and one Na2O–SiO2–P2O5 glass. The various Si/P↔Na/Ca contacts were probed by molecular dynamics (MD) simulations together with heteronuclear magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) experimentation utilizing (23)Na{(31)P} and (23)Na{(29)Si} REDOR, as well as (31)P{ (23)Na} and (29)Si{(23)Na} REAPDOR. We introduce an approach for quantifying the extent of Na(+)/Ca(2+) ordering around a given QP(n) or QSi(n) group, encoded by the preference factor 0⩽ PM ⩽ 1 conveying the relative weights of a random cation intermixing (PM = 0) and complete preference/ordering (PM = 1) for one of the species M, which represents either Na(+) or Ca(2+). The MD-derived preference factors reveal phosphate and silicate species surrounded by Na(+)/Ca(2+) ions intermixed nearly randomly (PM ≲ 0.15), except for the QSi(4) and QSi(1) groups, which manifest more significant cation ordering with preference for Na+ and Ca2+, respectively. The overall weak preferences are essentially independent of the Si and P contents of the glass, whereas PM primarily correlates with the total amount of network modifiers: as the latter is increased, the Na/Ca distribution around the {QP(0), QSi(1), QSi(2)} groups with preference for Ca2(+ )tend to randomize (i.e., PCa decreases), while the PNa-values grow slightly for the {QP(1), QSi(3), QSi(4)} species already preferring coordination of Na. The set of experimental preference factors {PCa} for the orthophosphate (QP(0)) groups extracted from (31)P{(23)Na} REAPDOR NMR-derived M2(P–Na) dipolar second moments agrees well with the MD-generated counterparts. Our results on the Na/Ca intermixing in soda-lime-silicate glasses are discussed in relation to previous reports, highlighting the dependence of the conclusion on the approach to data evaluation.

A model for the effects of germanium on silica biomineralization in choanoflagellates

PubMed Central

Chappell, Helen; Ratcliffe, Sarah; Goldstein, Raymond E.

2016-01-01

Silica biomineralization is a widespread phenomenon of major biotechnological interest. Modifying biosilica with substances like germanium (Ge) can confer useful new properties, although exposure to high levels of Ge disrupts normal biosilicification. No clear mechanism explains why this disruption occurs. Here, we study the effect of Ge on loricate choanoflagellates, a group of protists that construct a species-specific extracellular lorica from multiple siliceous costal strips. High Ge exposures were toxic, whereas lower Ge exposures produced cells with incomplete or absent loricae. These effects can be ameliorated by restoring the germanium : silicon ratio, as observed in other biosilicifying organisms. We developed simulations of how Ge interacts with polymerizing silica. In our models, Ge is readily incorporated at the ends of silica forming from silicic acid condensation, but this prevents further silica polymerization. Our ‘Ge-capping’ model is supported by observations from loricate choanoflagellates. Ge exposure terminates costal strip synthesis and lorica formation, resulting in disruption to cytokinesis and fatal build-up of silicic acid. Applying the Ge-capping model to other siliceous organisms explains the general toxicity of Ge and identifies potential protective responses in metalloid uptake and sensing. This can improve the design of new silica biomaterials, and further our understanding of silicon metabolism. PMID:27655668

High-Energy-Density Aqueous Magnesium-Ion Battery Based on a Carbon-Coated FeVO4 Anode and a Mg-OMS-1 Cathode.

PubMed

Zhang, Hongyu; Ye, Ke; Zhu, Kai; Cang, Ruibai; Yan, Jun; Cheng, Kui; Wang, Guiling; Cao, Dianxue

2017-12-01

Porous FeVO 4 is prepared by hydrothermal method and further modified by coating with carbon to obtain FeVO 4 /C with a hierarchical pore structure. FeVO 4 /C is used as an anodic electrode in aqueous rechargeable magnesium-ion batteries. The FeVO 4 /C material not only has improved electrical conductivity as a result of the carbon coating layer, but also has an increased specific surface area as a result of the hierarchical pore structure, which is beneficial for magnesium-ion insertion/deinsertion. Therefore, an aqueous rechargeable magnesium-ion full battery is successfully constructed with FeVO 4 /C as the anode, Mg-OMS-1 (OMS=octahedral molecular sieves) as the cathode, and 1.0 mol L -1 MgSO 4 as the electrolyte. The discharge capacity of the Mg-OMS-1//FeVO 4 /C aqueous battery is 58.9 mAh g -1 at a current density of 100 mA g -1 ; this value is obtained by calculating the total mass of two electrodes and the capacity retention rate of this device is 97.7 % after 100 cycles, with almost 100 % coulombic efficiency, which indicates that the system has a good electrochemical reversibility. Additionally, this system can achieve a high energy density of 70.4 Wh kg -1 , which provides powerful evidence that an aqueous magnesium-ion battery is possible. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Influence of environmental changes on the biogeochemistry of arsenic in a soil polluted by the destruction of chemical weapons: A mesocosm study.

PubMed

Thouin, Hugues; Battaglia-Brunet, Fabienne; Norini, Marie-Paule; Le Forestier, Lydie; Charron, Mickael; Dupraz, Sébastien; Gautret, Pascale

2018-06-15

Thermal destruction of chemical munitions from World War I led to the formation of a heavily contaminated residue that contains an unexpected mineral association in which a microbial As transformation has been observed. A mesocosm study was conducted to assess the impact of water saturation episodes and input of bioavailable organic matter (OM) on pollutant behavior in relation to biogeochemical parameters. Over a period of about eight (8) months, the contaminated soil was subjected to cycles of dry and wet periods corresponding to water table level variations. After the first four (4) months, fragmented litter from the nearby forest was placed on top of the soil. The mesocosm solid phase was sampled by three rounds of coring: at the beginning of the experiment, after four (4) months (before the addition of OM), and at the end of the experiment. Scanning electron microscopy coupled to energy dispersive X-ray spectroscopy observations showed that an amorphous phase, which was the primary carrier of As, Zn, and Cu, was unstable under water-saturated conditions and released a portion of the contaminants in solution. Precipitation of a lead arsenate chloride mineral, mimetite, in soils within the water saturated level caused the immobilization of As and Pb. Mimetite is a durable trap because of its large stability domain; however, this precipitation was limited by a low Pb concentration inducing that high amounts of As remained in solution. The addition of forest litter modified the quantities and qualities of soil OM. Microbial As transformation was affected by the addition of OM, which increased the concentration of both As(III)-oxidizing and As(V)-reducing microorganisms. The addition of OM negatively impacted the As(III) oxidizing rate, however As(III) oxidation was still the dominant reaction in accordance with the formation of arsenate-bearing minerals. Copyright © 2018 Elsevier B.V. All rights reserved.

Mussels can both outweigh and interact with the effects of terrestrial to freshwater resource subsidies on littoral benthic communities.

PubMed

Smith, Bethany R; Aldridge, David C; Tanentzap, Andrew J

2018-05-01

Litterfall is an important resource subsidy for lake ecosystems that primarily accumulates in littoral zones. Bivalves are abundant within littoral zones and may modify the effects of terrestrial resource subsidies through trophic interactions and engineering their surrounding habitat. Leaf inputs to lakes and freshwater mussel abundances are changing throughout the boreal ecoregion so we set out to investigate how the co-occurring benthic community might respond. We set up an in situ mesocosm experiment in Ramsey Lake, Sudbury, ON, Canada. Mesocosms contained sediments of either 5% or 35% terrestrial organic matter (tOM), into which we placed mussels (Elliptio complanata) at differing densities (0, 0.4 and 2musselsm -2 , with a sham mussel treatment at 0.4musselsm -2 ). Over one month we recorded the sediment chemistry (dissolved organic carbon, nitrogen and phosphorus), littoral organisms (benthic algae and zooplankton) and mussel growth. At high mussel densities we recorded a 90%, 80%, 45% and 40% reduction in phosphorus, dissolved organic carbon, nitrogen and benthic diatoms, respectively, whereas at low mussel densities we observed a 3-fold increase in zooplankton. We discuss that these results were caused by a combination of bioturbation and trophic interactions. Benthic diatom concentrations were also reduced by 20% in sediments of 35% tOM, likely due to shading and competition with bacteria. Mussel growth increased at high mussel densities but was offset at high tOM, likely due to the organic matter interfering with filter feeding. Our results suggest that mussels can alter the geochemical composition of sediments and abundances of associated littoral organisms, in some cases regardless of tOM quantity. Therefore, the dominant top-down control exerted by freshwater mussels may outweigh bottom-up effects of tOM additions. Generally, our study reveals the importance of considering dominant species when studying the effects of cross-ecosystem resource fluxes. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Mechanochemical Synthesis of Hydroxyapatite and Its Modifications: Composition, Structure, and Properties

NASA Astrophysics Data System (ADS)

Chaikina, M. V.; Bulina, N. V.; Ishchenko, A. V.; Prosanov, I. Yu.

2014-02-01

The mechanochemical method is used to synthesize samples of hydroxyapatite (HA) with substitution of the phosphate ion by silicate and zirconate ions, and substitution of calcium ions by copper ions. In the process of mechanochemical synthesis, carbonate ions and water molecules are incorporated into the structure of HA due to interaction of components of the reaction mixture with air. Intrusion of carbonate into the structure of HA is a competing process with modification of apatite by silicate and zirconate anions; therefore, the composition of the product during synthesis differs from the prescribed one. After annealing of the samples, the composition of the anion-modified HA can be described by the formula Са10(РО4)6- х (АО4) х (ОН)2- х , where (АО4)4- is the modifying anion. Substitution of calcium by copper ions localized at the Са1 position has been detected. Silver ions are not incorporated into the structure of HA, but are distributed in the apatite matrix in the form of nanocrystals of metallic silver.

Role of magnesium oxide and strontium oxide as modifiers in silicate-based bioactive glasses: Effects on thermal behaviour, mechanical properties and in-vitro bioactivity.

PubMed

Bellucci, Devis; Sola, Antonella; Salvatori, Roberta; Anesi, Alexandre; Chiarini, Luigi; Cannillo, Valeria

2017-03-01

The composition of a CaO-rich silicate bioglass (BG_Ca-Mix, in mol%: 2.3 Na 2 O; 2.3 K 2 O; 45.6 CaO; 2.6 P 2 O 5 ; 47.2 SiO 2 ) was modified by replacing a fixed 10mol% of CaO with MgO or SrO or fifty-fifty MgO-SrO. The thermal behaviour of the modified glasses was accurately evaluated via differential thermal analysis (DTA), heating microscopy and direct sintering tests. The presence of MgO and/or SrO didn't interfere with the thermal stability of the parent glass, since all the new glasses remained completely amorphous after sintering (treatment performed at 753°C for the glass with MgO; at 750°C with SrO; at 759°C with MgO and SrO). The sintered samples achieved good mechanical properties, with a Young's modulus ranging between 57.9±6.7 for the MgO-SrO modified composition and 112.6±8.0GPa for the MgO-modified one. If immersed in a simulated body fluid (SBF), the modified glasses after sintering retained the strong apatite forming ability of the parent glass, in spite of the presence of MgO and/or SrO. Moreover, the sintered glasses, tested with MLO-Y4 osteocytes by means of a multi-parametrical approach, showed a good bioactivity in vitro, since neither the glasses nor their extracts caused any negative effect on cell viability or any inhibition on cell growth. The best results were achieved by the MgO-modified glasses, both BGMIX_Mg and BGMIX_MgSr, which were able to exert a strong stimulating effect on the cell growth, thus confirming the beneficial effect of MgO on the glass bioactivity. Copyright © 2016 Elsevier B.V. All rights reserved.

Comment on "The shape and composition of interstellar silicate grains"

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

Bradley, J P; Ishii, H

2007-09-27

In the paper entitled 'The shape and composition of interstellar silicate grains' (A & A, 462, 667-676 (2007)), Min et al. explore non-spherical grain shape and composition in modeling the interstellar 10 and 20 {micro}m extinction features. This progression towards more realistic models is vitally important to enabling valid comparisons between dust observations and laboratory measurements. Min et al. proceed to compare their model results with GEMS (glass with embedded metals and sulfides) from IDPs (interplanetary dust particles) and to discuss the nature and origin of GEMS. Specifically, they evaluate the hypothesis of Bradley (1994) that GEMS are interstellar (IS)more » amorphous silicates. From a comparison of the mineralogy, chemical compositions, and infrared (IR) spectral properties of GEMS with their modeling results, Min et al. conclude: 'GEMS are, in general, not unprocessed leftovers from the diffuse ISM'. This conclusion is based, however, on erroneous and incomplete GEMS data. It is important to clarify first that Bradley (1994) never proposed that GEMS are unprocessed leftovers from the diffuse ISM, nor did he suggest that individual subnanogram mass GEMS are a representative sampling of the enormous mass of silicates in the diffuse ISM. Bradley (1994) simply showed that GEMS properties are consistent with those of IS amorphous silicates. It is widely accepted that circumstellar outflows are important sources of IS silicates, and whether GEMS are processed or not, the circumstellar heritage of some has been rigorously confirmed through measurements of non-solar oxygen (O) isotope abundances (Messenger et al., 2003; Floss et al., 2006). Keller et al. (2000) assert that even GEMS without detectable O isotope anomalies are probably also extrasolar IS silicates because they are embedded in carbonaceous material with non-solar D/H isotopic composition. (Much of the silicate dust in the ISM may be isotopically homogenized (Zhukovska et al., 2007)). Recent measurements show that the elemental compositions of GEMS with non-solar isotopic compositions are 'remarkably similar' to those with solar isotopic compositions (Keller & Messenger, 2007). About 80% of all isotopically anomalous IS silicates identified to date are GEMS with detectable and variable O isotopic memories of a circumstellar ancestry (Messenger, 2007). Bradley (1999) proposed that GEMS are IS silicates from 'a presolar interstellar molecular cloud, presumably the local molecular cloud from which the solar system formed'. Although based on incorrect data (detailed below), Min et al. propose that most GEMS actually formed in the presolar molecular cloud, and they further propose that none of them are IS silicates. IS silicate sources include molecular clouds, circumstellar outflows, supernovae, and even recently discovered black hole winds (Molster & Waters; 2003; Jones, 2005; Zhukovska et al. 2007; Markwick-Kemper et al. 2007). The average IS 10 {micro}m extinction feature observed along lines of sight towards the galactic center (modeled by Min et al.) presumably provides a good average for IS silicates, but it cannot distinguish amorphous silicates originating in the presolar molecular cloud from amorphous silicates originating in other interstellar molecular clouds or indeed other sources of amorphous IS silicates. Even if most GEMS accreted in the presolar molecular cloud, then they must also be representatives of some portion of the IS amorphous silicate population. Laboratory heating experiments indicate it is highly unlikely that GEMS were modified in a protoplanetary accretion disk environment (Brownlee et al. 2005). In summary, Min et al. conclude from their modeling of the shape and composition of IS silicates that the properties of GEMS are generally inconsistent with those of IS silicates. First, it has been rigorously confirmed via ion microprobe measurements that some GEMS are indeed presolar IS silicates. Second, regardless of whether GEMS, or components of GEMS, originated in presolar circumstellar outflows or a presolar molecular cloud they are all IS silicates. Third, key GEMS data reported in Min et al. are inaccurate. Had complete isotopic, chemical, mineralogical and infrared (IR) spectral properties of GEMS been considered, Min et al. may have concluded that the properties of GEMS, although not an exact match, are generally consistent with those of amorphous silicates in the ISM.« less

Expansion and diversification of high-latitude radiolarian assemblages in the late Eocene linked to a cooling event in the southwest Pacific

NASA Astrophysics Data System (ADS)

Pascher, K. M.; Hollis, C. J.; Bohaty, S. M.; Cortese, G.; McKay, R. M.; Seebeck, H.; Suzuki, N.; Chiba, K.

2015-12-01

The long-term cooling trend from middle to late Eocene was punctuated by several large-scale climate perturbations that culminated in a shift to "icehouse" climates at the Eocene-Oligocene transition. We present radiolarian micro-fossil assemblage and foraminiferal oxygen and carbon stable isotope data from Deep Sea Drilling Project (DSDP) sites 277, 280, 281, and 283 and Ocean Drilling Project (ODP) Site 1172 to identify significant oceanographic changes in the southwest Pacific through this climate transition (~ 40-30 Ma). We find that the Middle Eocene Climatic Optimum at ~ 40 Ma, which is truncated but identified by a negative shift in foraminiferal δ18O values at Site 277, is associated with a small increase in radiolarian taxa with low-latitude affinities (5 % of total fauna). In the early late Eocene at ~ 37 Ma, a positive oxygen isotope shift at Site 277 is correlated with the Priabonian Oxygen Isotope Maximum (PrOM). Radiolarian abundance, diversity, and preservation increase within this cooling event at Site 277 at the same time as diatom abundance. A negative δ18O excursion above the PrOM is correlated with a late Eocene warming event (~ 36.4 Ma). Radiolarian abundance and diversity decline within this event and taxa with low-latitude affinities reappear. Apart from this short-lived warming event, the PrOM and latest Eocene radiolarian assemblages are characterised by abundant high-latitude taxa. High-latitude taxa are also abundant during the late Eocene and early Oligocene (~ 38-30 Ma) at DSDP sites 280, 281, 283 and 1172 and are associated with very high diatom abundance. We therefore infer a northward expansion of high-latitude radiolarian taxa onto the Campbell Plateau in the latest Eocene. In the early Oligocene there is an overall decrease in radiolarian abundance and diversity at Site 277, and diatoms are scarce. These data indicate that, once the Antarctic Circumpolar Current was established in the early Oligocene (~ 30 Ma), a frontal system similar to present day developed, with nutrient-depleted Subantarctic waters bathing the area around DSDP Site 277, resulting in a more restricted siliceous plankton assemblage.

Modified cleaning method for biomineralized components

NASA Astrophysics Data System (ADS)

Tsutsui, Hideto; Jordan, Richard W.

2018-02-01

The extraction and concentration of biomineralized components from sediment or living materials is time consuming and laborious and often involves steps that remove either the calcareous or siliceous part, in addition to organic matter. However, a relatively quick and easy method using a commercial cleaning fluid for kitchen drains, sometimes combined with a kerosene soaking step, can produce remarkable results. In this study, the method is applied to sediments and living materials bearing calcareous (e.g., coccoliths, foraminiferal tests, holothurian ossicles, ichthyoliths, and fish otoliths) and siliceous (e.g., diatom valves, silicoflagellate skeletons, and sponge spicules) components. The method preserves both components in the same sample, without etching or partial dissolution, but is not applicable to unmineralized components such as dinoflagellate thecae, tintinnid loricae, pollen, or plant fragments.

Bacterial Community Composition Associated with Pyrogenic Organic Matter (Biochar) Varies with Pyrolysis Temperature and Colonization Environment

PubMed Central

Dai, Zhongmin; Barberán, Albert; Li, Yong; Brookes, Philip C.

2017-01-01

ABSTRACT Microbes that colonize pyrogenic organic matter (PyOM) (also called biochar) play an important role in PyOM mineralization and crucially affect soil biogeochemical cycling, while the microbial community composition associated with PyOM particles is poorly understood. We generated two manure-based PyOMs with different characteristics (PyOM pyrolyzed at the low temperature of 300°C [i.e., PyOM300] and at the high temperature of 700°C [i.e., PyOM700]) and added them to high-carbon (4.15%) and low-C (0.37%) soil for microbial colonization. 16S rRNA gene sequencing showed that Actinobacteria, particularly Actinomycetales, was the dominant taxon in PyOM, regardless of the PyOM pyrolysis temperature and soil type. Bacterial communities associated with PyOM particles from high-C soils were similar to those in non-PyOM-amended soils. PyOM300 had higher total microbial activity and more differential bacterial communities than PyOM700. More bacterial operational taxonomic units (OTUs) preferentially thrived on the low-pyrolysis-temperature PyOM, while some specific OTUs thrived on high-pyrolysis-temperature PyOM. In particular, Chloroflexi species tended to be more prevalent in high-pyrolysis-temperature PyOM in low-C soils. In conclusion, the differences in colonized bacterial community composition between the different PyOMs were strongly influenced by the pyrolysis temperatures of PyOM, i.e., under conditions of easily mineralizable C or fused aromatic C, and by other properties, e.g., pH, surface area, and nutrient content. IMPORTANCE Pyrogenic organic matter (PyOM) is widely distributed in soil and fluvial ecosystems and plays an important role in biogeochemical cycling. Many studies have reported changes in soil microbial communities stimulated by PyOM, but very little is known about the microbial communities associated with PyOM. The microbes that colonize PyOMs can participate in the mineralization of PyOM, so changing its structure affects the fate of PyOMs and contributes to soil biogeochemical cycling. This study identified the bacterial community composition associated with PyOMs on the basis of high-throughput sequencing and demonstrated that both PyOM pyrolysis temperature and the colonization environment determined the bacterial community composition. Our work increases our understanding of the dominant phylogenetic taxa associated with PyOMs, demonstrates mechanisms mediating microbial metabolism and growth in PyOMs, and expands a new research area for pyrogenic organic matter. This study identified the bacterial community composition associated with PyOM, which is widely distributed in the environment. Most bacterial OTUs preferentially thrived on PyOM pyrolyzed at low temperature, while some specific OTUs thrived on PyOM pyrolyzed at high temperature. PMID:28405627

Bacterial Community Composition Associated with Pyrogenic Organic Matter (Biochar) Varies with Pyrolysis Temperature and Colonization Environment.

PubMed

Dai, Zhongmin; Barberán, Albert; Li, Yong; Brookes, Philip C; Xu, Jianming

2017-01-01

Microbes that colonize pyrogenic organic matter (PyOM) (also called biochar) play an important role in PyOM mineralization and crucially affect soil biogeochemical cycling, while the microbial community composition associated with PyOM particles is poorly understood. We generated two manure-based PyOMs with different characteristics (PyOM pyrolyzed at the low temperature of 300°C [i.e., PyOM300] and at the high temperature of 700°C [i.e., PyOM700]) and added them to high-carbon (4.15%) and low-C (0.37%) soil for microbial colonization. 16S rRNA gene sequencing showed that Actinobacteria , particularly Actinomycetales , was the dominant taxon in PyOM, regardless of the PyOM pyrolysis temperature and soil type. Bacterial communities associated with PyOM particles from high-C soils were similar to those in non-PyOM-amended soils. PyOM300 had higher total microbial activity and more differential bacterial communities than PyOM700. More bacterial operational taxonomic units (OTUs) preferentially thrived on the low-pyrolysis-temperature PyOM, while some specific OTUs thrived on high-pyrolysis-temperature PyOM. In particular, Chloroflexi species tended to be more prevalent in high-pyrolysis-temperature PyOM in low-C soils. In conclusion, the differences in colonized bacterial community composition between the different PyOMs were strongly influenced by the pyrolysis temperatures of PyOM, i.e., under conditions of easily mineralizable C or fused aromatic C, and by other properties, e.g., pH, surface area, and nutrient content. IMPORTANCE Pyrogenic organic matter (PyOM) is widely distributed in soil and fluvial ecosystems and plays an important role in biogeochemical cycling. Many studies have reported changes in soil microbial communities stimulated by PyOM, but very little is known about the microbial communities associated with PyOM. The microbes that colonize PyOMs can participate in the mineralization of PyOM, so changing its structure affects the fate of PyOMs and contributes to soil biogeochemical cycling. This study identified the bacterial community composition associated with PyOMs on the basis of high-throughput sequencing and demonstrated that both PyOM pyrolysis temperature and the colonization environment determined the bacterial community composition. Our work increases our understanding of the dominant phylogenetic taxa associated with PyOMs, demonstrates mechanisms mediating microbial metabolism and growth in PyOMs, and expands a new research area for pyrogenic organic matter. This study identified the bacterial community composition associated with PyOM, which is widely distributed in the environment. Most bacterial OTUs preferentially thrived on PyOM pyrolyzed at low temperature, while some specific OTUs thrived on PyOM pyrolyzed at high temperature.

Redefining dermatomyositis: a description of new diagnostic criteria that differentiate pure dermatomyositis from overlap myositis with dermatomyositis features.

PubMed

Troyanov, Yves; Targoff, Ira N; Payette, Marie-Pier; Raynauld, Jean-Pierre; Chartier, Suzanne; Goulet, Jean-Richard; Bourré-Tessier, Josiane; Rich, Eric; Grodzicky, Tamara; Fritzler, Marvin J; Joyal, France; Koenig, Martial; Senécal, Jean-Luc

2014-11-01

Dermatomyositis (DM) is a major clinical subset of autoimmune myositis (AIM). The characteristic DM rash (Gottron papules, heliotrope rash) and perifascicular atrophy at skeletal muscle biopsy are regarded as specific features for this diagnosis. However, new concepts are challenging the current definition of DM. A modified Bohan and Peter classification of AIM was proposed in which the core concept was the inclusion of the diagnostic significance of overlap connective tissue disease features. In this clinical classification, a DM rash in association with myositis in the absence of overlap features indicates a diagnosis of pure DM. However, overlap features in association with myositis allow a diagnosis of overlap myositis (OM), irrespective of the presence or absence of the DM rash. Perifascicular atrophy may be present in both pure DM and OM. Recently, the presence of perifascicular atrophy in myositis without a DM rash was proposed as diagnostic of a novel entity, adermatopathic DM. We conducted the present study to evaluate these new concepts to further differentiate pure DM from OM.Using the modified Bohan and Peter classification, we performed a follow-up study of a longitudinal cohort of 100 consecutive adult French Canadian patients with AIM, including 44 patients with a DM phenotype, defined as a DM rash, and/or DM-type calcinosis, and/or the presence of perifascicular atrophy on muscle biopsy. A detailed evaluation was performed for overlap features, the extent and natural history of the DM rash, adermatopathic DM, DM-specific and overlap autoantibodies by protein A immunoprecipitation on coded serum samples, and associations with cancer and survival.Two distinct subsets were identified in patients with a DM phenotype: pure DM (n = 24) and OM with DM features, or OMDM (n = 20). In pure DM, the DM rash was a dominant finding. It was the first disease manifestation, was always present at the time of myositis diagnosis, and was associated with a high cutaneous score and chronicity. Concurrent heliotrope rash and Gottron papules (positive predictive value [PPV] 91%), as well as the V-sign and/or shawl sign (PPV 100%), were diagnostic of pure DM. Anti-Mi-2, anti-MJ, and anti-p155 autoantibodies were present in 50% of pure DM patients and were restricted to this subset (PPV 100%). Cancer was present in 21% of pure DM patients. The 15-year survival was excellent (92%).In contrast, in patients with OMDM, the first manifestation was proximal muscle weakness or other skeletal muscle-related complaints. The DM rash appeared at diagnosis or at follow-up, was associated with a low cutaneous extent score and was transient. Adermatopathic DM, which was absent in pure DM, was highly predictive (PPV 100%) of OMDM. Overlap autoantibodies (including anti-Jo-1, anti-PL-7, anti-PM-Scl, anti-U1RNP, and/or anti-U5-RNP) were found in 70% of OMDM patients. OMDM was not associated with cancer, but the 15-year survival was significantly decreased (65%).Perifascicular atrophy occurred as commonly in OMDM (n = 6/20, 30%) as in pure DM (n = 4/24, 17%) patients. These 6 OMDM patients had adermatopathic DM at myositis diagnosis, and only 1 of them developed a DM rash at follow-up, emphasizing the lack of specificity of perifascicular atrophy for pure DM.In conclusion, using the modified Bohan and Peter classification of AIM allowed identification of OMDM, a new clinical subset of OM. Furthermore, identification of OMDM allowed recognition of pure DM as a new entity that was distinct from OMDM or from OM without DM features. However, the absolute specificity of a DM rash and perifascicular muscle atrophy for the diagnosis of pure DM was lost. The distinctive clinical manifestations and autoantibody profiles presented are proposed as diagnostic criteria to differentiate pure DM from OMDM.

Redefining Dermatomyositis

PubMed Central

Troyanov, Yves; Targoff, Ira N; Payette, Marie-Pier; Raynauld, Jean-Pierre; Chartier, Suzanne; Goulet, Jean-Richard; Bourré-Tessier, Josiane; Rich, Eric; Grodzicky, Tamara; Fritzler, Marvin J.; Joyal, France; Koenig, Martial; Senécal, Jean-Luc

2014-01-01

Abstract Dermatomyositis (DM) is a major clinical subset of autoimmune myositis (AIM). The characteristic DM rash (Gottron papules, heliotrope rash) and perifascicular atrophy at skeletal muscle biopsy are regarded as specific features for this diagnosis. However, new concepts are challenging the current definition of DM. A modified Bohan and Peter classification of AIM was proposed in which the core concept was the inclusion of the diagnostic significance of overlap connective tissue disease features. In this clinical classification, a DM rash in association with myositis in the absence of overlap features indicates a diagnosis of pure DM. However, overlap features in association with myositis allow a diagnosis of overlap myositis (OM), irrespective of the presence or absence of the DM rash. Perifascicular atrophy may be present in both pure DM and OM. Recently, the presence of perifascicular atrophy in myositis without a DM rash was proposed as diagnostic of a novel entity, adermatopathic DM. We conducted the present study to evaluate these new concepts to further differentiate pure DM from OM. Using the modified Bohan and Peter classification, we performed a follow-up study of a longitudinal cohort of 100 consecutive adult French Canadian patients with AIM, including 44 patients with a DM phenotype, defined as a DM rash, and/or DM-type calcinosis, and/or the presence of perifascicular atrophy on muscle biopsy. A detailed evaluation was performed for overlap features, the extent and natural history of the DM rash, adermatopathic DM, DM-specific and overlap autoantibodies by protein A immunoprecipitation on coded serum samples, and associations with cancer and survival. Two distinct subsets were identified in patients with a DM phenotype: pure DM (n = 24) and OM with DM features, or OMDM (n = 20). In pure DM, the DM rash was a dominant finding. It was the first disease manifestation, was always present at the time of myositis diagnosis, and was associated with a high cutaneous score and chronicity. Concurrent heliotrope rash and Gottron papules (positive predictive value [PPV] 91%), as well as the V-sign and/or shawl sign (PPV 100%), were diagnostic of pure DM. Anti-Mi-2, anti-MJ, and anti-p155 autoantibodies were present in 50% of pure DM patients and were restricted to this subset (PPV 100%). Cancer was present in 21% of pure DM patients. The 15-year survival was excellent (92%). In contrast, in patients with OMDM, the first manifestation was proximal muscle weakness or other skeletal muscle-related complaints. The DM rash appeared at diagnosis or at follow-up, was associated with a low cutaneous extent score and was transient. Adermatopathic DM, which was absent in pure DM, was highly predictive (PPV 100%) of OMDM. Overlap autoantibodies (including anti-Jo-1, anti-PL-7, anti-PM-Scl, anti-U1RNP, and/or anti-U5-RNP) were found in 70% of OMDM patients. OMDM was not associated with cancer, but the 15-year survival was significantly decreased (65%). Perifascicular atrophy occurred as commonly in OMDM (n = 6/20, 30%) as in pure DM (n = 4/24, 17%) patients. These 6 OMDM patients had adermatopathic DM at myositis diagnosis, and only 1 of them developed a DM rash at follow-up, emphasizing the lack of specificity of perifascicular atrophy for pure DM. In conclusion, using the modified Bohan and Peter classification of AIM allowed identification of OMDM, a new clinical subset of OM. Furthermore, identification of OMDM allowed recognition of pure DM as a new entity that was distinct from OMDM or from OM without DM features. However, the absolute specificity of a DM rash and perifascicular muscle atrophy for the diagnosis of pure DM was lost. The distinctive clinical manifestations and autoantibody profiles presented are proposed as diagnostic criteria to differentiate pure DM from OMDM. PMID:25500701

Influence of surface modified basalt fiber on strength of cinder lightweight aggregate concrete

NASA Astrophysics Data System (ADS)

Xiao, Liguang; Li, Jiheng; Liu, Qingshun

2017-12-01

In order to improve the bonding and bridging effect between volcanic slag lightweight aggregate concrete cement and basalt fiber, The basalt fiber was subjected to etching and roughening treatment by NaOH solution, and the surface of the basalt fiber was treated with a mixture of sodium silicate and micro-silica powder. The influence of modified basalt fiber on the strength of volcanic slag lightweight aggregate concrete was systematically studied. The experimental results show that the modified basalt fiber volcanic slag lightweight aggregate concrete has a flexural strength increased by 47%, the compressive strength is improved by 16% and the toughness is increased by 27% compared with that of the non-fiber.

Polyethylenimine-magadiite layered silicate sorbent for CO2 capture.

PubMed

Vieira, Rômulo B; Pastore, Heloise O

2014-02-18

This paper describes the preparation of a Layered Silicate Sorbent (LSS) for CO2 capture using the layered silicate magadiite and organo-magadiite modified with polyethylenimine (PEI). The sorbents were characterized and revealed the presence of PEI as well as its interaction with CO2 at low temperatures. The thermal stability of sorbents was confirmed by thermogravimetry experiments, and the adsorption capacity was evaluated by CO2-TPD experiments. Two kinds of PEI are present in the sorbent, one exposed PEI layer that is responsible for higher CO2 adsorption because its sites are external and another one, bulky PEI, capable of low CO2 adsorption due to the internal position of sites. The contribution of the exposed PEI layer may be increased by a previous exchange of CTA(+), but the presence of the surfactant decreased the total adsorption capacity. MAG-PEI25 reached a maximum adsorption capacity of 6.11 mmol g(-1) at 75 °C for 3 h of adsorption and showed a kinetic desorption of around 15 min at 150 °C.

Synthesis and Structure Property Studies of Toughened Epoxy Resins Via Functionalized Polysiloxanes.

DTIC Science & Technology

1987-09-30

34 87S N4 SYNTHESIS RNO STRUCTURE PROPERTY STUDIES OF OP NDD mEPOXY RESINS YIN FU.. (U) VIROINIR POLYTECHNIC INST OM STNTE UNIY RCKSBURG DEPT OF C.. J...Classification) Synthesis and Structure Property Studies of Toughened Epoxy Resins Via Functionalized Polysiloxanes 12. PERSONALAUTHOR(S) J. 5. HitTIe... Resins , Toughening 19. ABSTRACT (Continue on reverse if necessary and identify by block number) Epoxy resins chemically modified with functionally

6-Mercaptopurine modifies cerebrospinal fluid T cell abnormalities in paediatric opsoclonus-myoclonus as steroid sparer.

PubMed

Pranzatelli, M R; Tate, E D; Allison, T J

2017-11-01

The purpose of this study was to evaluate the capacity of 6-mercaptopurine (6-MP), a known immunosuppressant, to normalize cerebrospinal fluid (CSF) lymphocyte frequencies in opsoclonus-myoclonus syndrome (OMS) and function as a steroid sparer. CSF and blood lymphocytes were immunophenotyped in 11 children with OMS (without CSF B cell expansion) using a comprehensive panel of cell surface adhesion, activation and maturation markers by flow cytometry, and referenced to 18 paediatric controls. Drug metabolites, lymphocyte counts and liver function tests were used clinically to monitoring therapeutic range and toxicity. In CSF, adjunctive oral 6-MP was associated with a 21% increase in the low percentage of CD4 + T cells in OMS, restoring the CD4/CD8 ratio. The percentage of CD4 + T cells that were interferon (IFN)-γ + was reduced by 66%, shifting the cytokine balance away from T helper type 1 (Th1) (proinflammatory) predominance. The percentage of natural killer (NK) cells decreased significantly in CSF (-32%) and blood (-67 to -82%). Low blood absolute lymphocyte count was more predictive of improvement in CSF lymphocyte proportions (correlated with % CD4 + T cells) than the 6-thioguanine level (no correlation). 6-MP was difficult to titrate: 50% achieved the target absolute lymphocyte count (< 1·5 K/mm); 20%, the 'therapeutic' 6-thioguanine level; and 40% the non-toxic 6-methylmercaptopurine level. Side effects and transaminase elevation were mild and reversible. Clinical steroid-sparing properties and lowered relapse frequency were demonstrated. 6-MP displayed unique pharmacodynamic properties that may be useful in OMS and other autoimmune disorders. Its steroid sparer capacity is limited to children in whom the therapeutic window can be reached without limiting pharmacokinetic factors or side effects. © 2017 British Society for Immunology.

Analyzing the molecular mechanism of lipoprotein localization in Brucella

PubMed Central

Goolab, Shivani; Roth, Robyn L.; van Heerden, Henriette; Crampton, Michael C.

2015-01-01

Bacterial lipoproteins possess diverse structure and functionality, ranging from bacterial physiology to pathogenic processes. As such many lipoproteins, originating from Brucella are exploited as potential vaccines to countermeasure brucellosis infection in the host. These membrane proteins are translocated from the cytoplasm to the cell membrane where they are anchored peripherally by a multifaceted targeting mechanism. Although much research has focused on the identification and classification of Brucella lipoproteins and their potential use as vaccine candidates for the treatment of Brucellosis, the underlying route for the translocation of these lipoproteins to the outer surface of the Brucella (and other pathogens) outer membrane (OM) remains mostly unknown. This is partly due to the complexity of the organism and evasive tactics used to escape the host immune system, the variation in biological structure and activity of lipoproteins, combined with the complex nature of the translocation machinery. The biosynthetic pathway of Brucella lipoproteins involves a distinct secretion system aiding translocation from the cytoplasm, where they are modified by lipidation, sorted by the lipoprotein localization machinery pathway and thereafter equipped for export to the OM. Surface localized lipoproteins in Brucella may employ a lipoprotein flippase or the β-barrel assembly complex for translocation. This review provides an overview of the characterized Brucella OM proteins that form part of the OM, including a handful of other characterized bacterial lipoproteins and their mechanisms of translocation. Lipoprotein localization pathways in gram negative bacteria will be used as a model to identify gaps in Brucella lipoprotein localization and infer a potential pathway. Of particular interest are the dual topology lipoproteins identified in Escherichia coli and Haemophilus influenza. The localization and topology of these lipoproteins from other gram negative bacteria are well characterized and may be useful to infer a solution to better understand the translocation process in Brucella. PMID:26579096

Investigation of OMNIgene·SPUTUM performance in delayed tuberculosis testing by smear, culture, and Xpert MTB/RIF assays in Uganda.

PubMed

Kelly-Cirino, C D; Musisi, E; Byanyima, P; Kaswabuli, S; Andama, A; Sessolo, A; Sanyu, I; Zawedde, J; Curry, P S; Huang, L

2017-06-01

OMNIgene·SPUTUM (OM-S) is a sample transport reagent designed to work with all tuberculosis diagnostics while eliminating the need for cold chain. OM-S-treated sputum samples were assayed in several tests after multiday holds. Raw sputa from 100 patients underwent direct smear microscopy, were manually split and assigned to the OM-S group [OM-S added at collection (no other processing required) and tested after 0- to 5-day holds at room temperature] or standard-of-care (SOC) group (NaOH/N-acetyl l-cysteine decontamination, all tested on day of collection). Concentrated smear microscopy, Lowenstein Jensen (LJ) culture, and mycobacteria growth indicator tube (MGIT) culture were performed. For patients with negative direct smear, a second sample was split, with SOC (raw sputum) and OM-S portions (sediment) tested in the Xpert MTB/RIF (Xpert) assay. OM-S group and SOC group results were strongly concordant on all four tests [range, 89% (MGIT)-97% (Xpert)]. OM-S MGIT, LJ, and Xpert tests were in statistical agreement with SOC MGIT as reference. OM-S specimens had lower culture contamination rates (3% vs. 10% LJ; 2% vs. 5% MGIT) but required, on average, 5.6 additional days to become MGIT-positive. The findings suggest that samples held/transported in OM-S are compatible with smear microscopy, LJ or MGIT culture, and Xpert, and perform comparably to fresh sputum samples. Larger feasibility studies are warranted. Copyright © 2017. Published by Elsevier Ltd.

20 CFR 229.52 - Age reduction when a reduced age O/M is effective before DIB O/M.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Age reduction when a reduced age O/M is... Minimum Rate § 229.52 Age reduction when a reduced age O/M is effective before DIB O/M. If an employee received a reduced age O/M before the effective date of a DIB O/M, the PIA amount for the DIB O/M is...

Processes Influencing the Timing and Volume of Eruptions From the Youngest Supervolcano on Earth

NASA Astrophysics Data System (ADS)

Wilson, C. J. N.; Barker, S. J.; Morgan, D. J.; Rowland, J. V.; Schipper, I.

2015-12-01

In their stratigraphic records, silicic caldera volcanoes display wide ranges of eruptive styles and volumes. However, relationships between frequency and magnitude are often complex, and the forecasting of future activity is inherently problematic. Taupo volcano, New Zealand, provides a unique opportunity to investigate eruptive histories from a hyperactive, large silicic magmatic system with eruptive volumes that span 3-4 orders of magnitude, and show no clear relationships with the repose period. Taupo hosted the world's most recent supereruption at 25.4 ka, which discharged 530 km3 of magma in the episodic 10-phase Oruanui event. Only 5 kyr later, Taupo revived, with 3 dacitic eruptions from 21.5-17 ka and 25 rhyolite eruptions from 12-1.7 ka. Here we use trends in whole rock, glass and mineral chemistry to show how the magma system reestablished following the Oruanui event, and to consider what processes influence the state of the modern volcano. The post-Oruanui dacites reflect the first products of the rebuilding silicic magma system, as most of the Oruanui mush was reconfigured or significantly modified in composition following thermal fluxing accompanying post-caldera collapse readjustment. Compositional variations within the younger rhyolites at <12 ka reflect fine-scale temporal changes in mineral phase stability, closely linked to the development, stabilization and maturation of a new silicic mush system. For the most recent eruptions, the system underwent destabilization, resulting in increased volumes of melt extraction from the silicic mush. Orthopyroxene Fe-Mg diffusion timescales indicate that the onset of rapid heating and priming of the silicic mush occurred <100 years prior to the <2.15 ka eruptions, with subsequent melt accumulation occurring in only decades. The largest post-Oruanui eruption at 232 AD culminated from elevated mafic magma supply to the silicic mush pile, rapid melt accumulation and high differential tectonic stress build up, leading to one of the largest and most violent Holocene eruptions globally. The latest eruptions of Taupo highlight the multiple controls on the timing of eruptions, and demonstrate how the magmatic system can rapidly change behavior to generate large eruptible melt bodies on timescales of direct relevance to humans and monitoring initiatives.

Evaluation of the Ca ion release, pH and surface apatite formation of a prototype tricalcium silicate cement.

PubMed

Yamamoto, S; Han, L; Noiri, Y; Okiji, T

2017-12-01

To evaluate the Ca 2+ -releasing, alkalizing and apatite-like surface precipitate-forming abilities of a prototype tricalcium silicate cement, which was mainly composed of synthetically prepared tricalcium silicate and zirconium oxide radiopacifier. The prototype tricalcium silicate cement, white ProRoot MTA (WMTA) and TheraCal LC (a light-cured resin-modified calcium silicate-filled material) were examined. The chemical compositions were analysed with a wavelength-dispersive X-ray spectroscopy electron probe microanalyser with an image observation function (SEM-EPMA). The pH and Ca 2+ concentrations of water in which the set materials had been immersed were measured, and the latter was assessed with the EDTA titration method. The surface precipitates formed on the materials immersed in phosphate-buffered saline (PBS) were analysed with SEM-EPMA and X-ray diffraction (XRD). Kruskal-Wallis tests followed by Mann-Whitney U-test with Bonferroni correction were used for statistical analysis (α = 0.05). The prototype cement contained Ca, Si and Zr as major elemental constituents, whereas it did not contain some metal elements that were detected in the other materials. The Ca 2+ concentrations and pH of the immersion water samples exhibited the following order: WMTA = prototype cement > TheraCal LC (P < 0.05). All three materials produced Ca- and P-containing surface precipitates after PBS immersion, and the precipitates produced by TheraCal LC displayed lower Ca/P ratios than those formed by the other materials. XRD peaks corresponding to hydroxyapatite were detected in the precipitates produced by the prototype cement and WMTA. The prototype tricalcium silicate cement exhibited similar Ca 2+ -releasing, alkalizing and apatite-like precipitate-forming abilities to WMTA. The Ca 2+ -releasing, alkalizing and apatite-like precipitate-forming abilities of TheraCal LC were lower than those of the other materials. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Measurements of the Activity of dissolved H2O in an Andesite Melt

NASA Astrophysics Data System (ADS)

Moore, G. M.; Touran, J. P.; Pu, X.; Kelley, K. A.; Cottrell, E.; Ghiorso, M. S.

2016-12-01

The large effect of dissolved H2O on the physical and chemical nature of silicate melts, and its role in driving volcanism, is well known and underscores the importance of this volatile component. A complete understanding of the chemical behavior of dissolved H2O in silicate melts requires the quantification of its thermodynamic activity as a function of pressure, temperature, and melt composition, particularly at low H2O contents (i.e. at under-saturated conditions). Knowledge of the activity of H2O in silicate melts at H2O-undersaturated conditions will improve our understanding of hydrous phase equilibria, as well as our models of physical melt properties. Measurement of the activity of any silicate melt component, much less that of a volatile component such as H2O, is a difficult experimental task however. By using a modified double capsule design (Matjuschkin et al, 2015) to control oxygen fugacity in piston cylinder experiments, along with high precision X-ray absorption techniques (XANES) to measure iron oxidation state in silicate glasses (Cottrell et al, 2009), we are able to constrain the H2O activity in silicate melts at under-saturated conditions. Preliminary results on an andesite melt with low H2O content (3 wt%) have been shown (Moore et al, 2016) to match predicted H2O activity values calculated using the H2O equation of state of Duan and Zhang (1996) and the H2O solubility model of Ghiorso and Gualda (2015). More recent results on the same andesite melt containing approximately 5 wt% H2O however show a large negative deviation from the predicted values. Reversal experiments involving an oxidized starting material are ongoing, as well as further characterization of the samples to detect the presence of possible contaminants that would induce reduction of the melt beyond that related to the H2O activity (e.g. graphite contamination).

Pesticide adsorption in relation to soil properties and soil type distribution in regional scale.

PubMed

Kodešová, Radka; Kočárek, Martin; Kodeš, Vít; Drábek, Ondřej; Kozák, Josef; Hejtmánková, Kateřina

2011-02-15

Study was focused on the evaluation of pesticide adsorption in soils, as one of the parameters, which are necessary to know when assessing possible groundwater contamination caused by pesticides commonly used in agriculture. Batch sorption tests were performed for 11 selected pesticides and 13 representative soils. The Freundlich equations were used to describe adsorption isotherms. Multiple-linear regressions were used to predict the Freundlich adsorption coefficients from measured soil properties. Resulting functions and a soil map of the Czech Republic were used to generate maps of the coefficient distribution. The multiple linear regressions showed that the K(F) coefficient depended on: (a) combination of OM (organic matter content), pH(KCl) and CEC (cation exchange capacity), or OM, SCS (sorption complex saturation) and salinity (terbuthylazine), (b) combination of OM and pH(KCl), or OM, SCS and salinity (prometryne), (c) combination of OM and pH(KCl), or OM and ρ(z) (metribuzin), (d) combination of OM, CEC and clay content, or clay content, CEC and salinity (hexazinone), (e) combination of OM and pH(KCl), or OM and SCS (metolachlor), (f) OM or combination of OM and CaCO(3) (chlorotoluron), (g) OM (azoxystrobin), (h) combination of OM and pH(KCl) (trifluralin), (i) combination of OM and clay content (fipronil), (j) combination of OM and pH(KCl), or OM, pH(KCl) and CaCO(3) (thiacloprid), (k) combination of OM, pH(KCl) and CEC, or sand content, pH(KCl) and salinity (chlormequat chloride). Copyright © 2010 Elsevier B.V. All rights reserved.

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

Moritz, MichaL; Laniecki, Marek, E-mail: laniecki@amu.edu.pl

A series of modified SBA-15 materials were applied in drug delivery systems. The internal surface of siliceous hexagonal structure of SBA-15 was modified with different amount of (3-mercaptopropyl)trimethoxysilane (MPTMS) and oxidized in the presence of hydrogen peroxide. The sulfonated material was loaded with metoprolol tartrate or papaverine hydrochloride. Both drugs indicated strong chemical interaction with modified mesoporous surface. The characteristic of the obtained materials was performed with XRD and DRUV-vis spectrometry, themogravimetry and nitrogen adsorption (BET) measurements. The obtained results show that modification of the mesoporous materials leads towards significant decrease of the drug delivery rate. - Graphical abstract: XRDmore » and DSC of the -SO{sub 3}H modified SBA-15 loaded with metoprolol. Highlights: > Modification of SBA-15 internal channels with SO{sub 3}H groups. > Adsorption of metoprolol and papaverine on modified SBA-15. > Uniform and homogeneous distribution of the drugs inside the mesoporous structure of SBA-15. > Release of the supported drugs.« less

Pyroxene-melt equilibria. [for lunar maria basalts

NASA Technical Reports Server (NTRS)

Nielsen, R. L.; Drake, M. J.

1979-01-01

A thermodynamic analysis of pyroxene-melt equilibria is performed through use of a literature survey of analyses of high-Ca pyroxene and coexisting silicate melt pairs and analyses of low-Ca pyroxene silicate melt pairs. Reference is made to a modified version of a model developed by Bottinga and Weill (1972) which more successfully accounts for variations in melt composition than does a model which considers the melt to be composed of simple oxides which mix ideally. By using a variety of pyroxene melt relations, several pyroxene-melt and low-Ca pyroxene-high-Ca pyroxene geothermometers are developed which have internally consistant precisions of approximately + or - 20 C. Finally, it is noted that these equations may have application in modeling the evolution of mineral compositions during differentiation of basaltic magmas.

Synthesis of Cation and Water Free Cryptomelane Type OMS-2 Cathode Materials: The Impact of Tunnel Water on Electrochemistry

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

Poyraz, Altug S.; Huang, Jianping; Zhang, Bingjie

Cryptomelane type manganese dioxides (α-MnO 2, OMS-2) are interesting potential cathode materials due to the ability of their one dimensional (1D) tunnels to reversibly host various cations including Li +and an accessible stable 3+/4+ redox couple. Here, we synthesized metal cation free OMS-2 materials where the tunnels were occupied by only water and hydronium ions. Water was subsequently removed from the tunnels. Cation free OMS-2 and Dry-OMS-2 were used as cathodes in Li based batteries to investigate the role of tunnel water on their electrochemistry. The initial discharge capacity was higher for Dry-OMS-2 (252 mAh/g) compared to OMS-2 (194 mAh/g),more » however, after 100 cycles Dry-OMS-2 and OMS-2 delivered 137 mAh/g and 134 mAh/g, respectively. Li +ion diffusion was more facile for Dry-OMS as evidenced by rate capability, at 400 mA/g. Dry-OMS-2 delivered 135mAh/g whereas OMS-2 delivered ~115 mAh/g. This first report of the impact of tunnel water on the electrochemistry of OMS-2 type materials demonstrates that the presence of tunnel water in OMS-2 type materials negatively impacts the electrochemistry.« less

Nanohybrids of magnetic iron-oxide particles in hydrophobic organoclays for oil recovery.

PubMed

Hsu, Ru-Siou; Chang, Wen-Hsin; Lin, Jiang-Jen

2010-05-01

Nanohybrids with magnetic iron-oxide nanoparticles (FeNPs) embedded in the multilayered silicate clay were synthesized by in situ Fe(2+)/Fe(3+) coprecipitation. The natural clay, sodium montmorillonite (Na(+)-MMT), was first modified with hydrophobic poly(oxypropylene)amine salts (POP at 2000 and 4000 g/mol M(w)). The two POP-intercalated organoclays, with a silicate interlayer expansion from 1.2 to 5.2 and 9.2 nm, respectively, are suitable for embedding FeNPs. The presence of POP organics in layered structure created the space for intercalating with FeNPs of 2-4 nm in diameter, observed by transmission electronic microscope. The synthesized nanohybrids of POP4000/MMT-FeNP was composed of 17% iron oxide and 51 wt % POP within the silicate basal spacing of 5.0 nm. In contrast, the lower molecular weight of POP2000 intercalated MMT failed to encapsulate FeNPs in a significant amount, but resulting a "crowding-out effect" that caused the silicate interlayer space to shrink from 5.2 to 1.8 nm because of the replacement of the POP salt by Fe(2+)/Fe(3+) ions. The synthesis required the use of high molecular weight POP4000 and low temperatures (<4 degrees C) for a better dispersion in the reaction medium. The presence of POP in the layered silicate facilitated a homogeneous POP/MMT in water, associating with Fe(2+)/Fe(3+) ions and spatially accommodating for the subsequently generated FeNPs. The synthesized nanostructure consisting of POP and FeNP could be used as a pollutant remedy because of its ability to adsorbing crude oil and it is maneuverable under an applied magnetism.

Modifier cation effects on 29Si nuclear shielding anisotropies in silicate glasses

NASA Astrophysics Data System (ADS)

Baltisberger, Jay H.; Florian, Pierre; Keeler, Eric G.; Phyo, Pyae A.; Sanders, Kevin J.; Grandinetti, Philip J.

2016-07-01

We have examined variations in the 29Si nuclear shielding tensor parameters of SiO4 tetrahedra in a series of seven alkali and alkaline earth silicate glass compositions, Cs2O · 4.81 SiO2, Rb2O · 3.96 SiO2, Rb2O · 2.25 SiO2, K2O · 4.48 SiO2, Na2O · 4.74 SiO2, BaO · 2.64 SiO2, and SrO · 2.36 SiO2, using natural abundance 29Si two-dimensional magic-angle flipping (MAF) experiments. Our analyses of these 2D spectra reveal a linear dependence of the 29Si nuclear shielding anisotropy of Q(3) sites on the Si-non-bridging oxygen bond length, which in turn depends on the cation potential and coordination of modifier cations to the non-bridging oxygen. We also demonstrate how a combination of Cu2+ as a paramagnetic dopant combined with echo train acquisition can reduce the total experiment time of 29Si 2D NMR measurements by two orders of magnitude, enabling higher throughput 2D NMR studies of glass structure.

Mesoporous titanosilicates with high loading of titanium synthesized in mild acidic buffer solution.

PubMed

Tang, Jianting; Liu, Jian; Yang, Jie; Feng, Zhaochi; Fan, Fengtao; Yang, Qihua

2009-07-15

Mesoporous titanosilicates with high titanium content were synthesized under mild acidic conditions (pH=4.4, HAc-NaAc buffer solution) by co-condensation of acetylacetone-modified titanium isopropoxide (Ti(OBu(n))(3) (acac)) and mixture of sodium silicate with tetramethoxysilane (TMOS) or tetraethoxysilane (TEOS) or tetrakis(2-hydroxyethyl)orthosilicate (EGMS), using block copolymer Pluronic P123 as template. The combined results of XRD, N(2) sorption and TEM show that the highly regular structure of the mesoporous titanosilicates can still be obtained when Ti/Si molar ratio in the final product is as high as 0.059. The results of UV-vis diffuse reflectance spectra and UV resonance Raman spectra show that the framework titanium species are predominant in the mesoporous titanosilicates when Ti/Si molar ratio in the final product is less than 0.042. The mixture of sodium silicate and EGMS was proved to be the best silicon source for the synthesis of titanosilicates with ordered mesostructure and high titanium content. The efficiency of this synthetic method may be attributed to the mild acidic medium as well as the modified hydrolysis-condensation rate and hydrophility of the precursors.

Modifier cation effects on (29)Si nuclear shielding anisotropies in silicate glasses.

PubMed

Baltisberger, Jay H; Florian, Pierre; Keeler, Eric G; Phyo, Pyae A; Sanders, Kevin J; Grandinetti, Philip J

2016-07-01

We have examined variations in the (29)Si nuclear shielding tensor parameters of SiO4 tetrahedra in a series of seven alkali and alkaline earth silicate glass compositions, Cs2O·4.81 SiO2, Rb2O·3.96 SiO2, Rb2O·2.25 SiO2, K2O·4.48 SiO2, Na2O·4.74 SiO2, BaO·2.64 SiO2, and SrO·2.36 SiO2, using natural abundance (29)Si two-dimensional magic-angle flipping (MAF) experiments. Our analyses of these 2D spectra reveal a linear dependence of the (29)Si nuclear shielding anisotropy of Q((3)) sites on the Si-non-bridging oxygen bond length, which in turn depends on the cation potential and coordination of modifier cations to the non-bridging oxygen. We also demonstrate how a combination of Cu(2+) as a paramagnetic dopant combined with echo train acquisition can reduce the total experiment time of (29)Si 2D NMR measurements by two orders of magnitude, enabling higher throughput 2D NMR studies of glass structure. Copyright © 2016 Elsevier Inc. All rights reserved.

Localized application of soil organic matter shifts distribution of cluster roots of white lupin in the soil profile due to localized release of phosphorus

PubMed Central

Li, Hai-Gang; Shen, Jian-Bo; Zhang, Fu-Suo; Lambers, Hans

2010-01-01

Background and Aims Phosphorus (P) is a major factor controlling cluster-root formation. Cluster-root proliferation tends to concentrate in organic matter (OM)-rich surface-soil layers, but the nature of this response of cluster-root formation to OM is not clear. Cluster-root proliferation in response to localized application of OM was characterized in Lupinus albus (white lupin) grown in stratified soil columns to test if the stimulating effect of OM on cluster-root formation was due to (a) P release from breakdown of OM; (b) a decrease in soil density; or (c) effects of micro-organisms other than releasing P from OM. Methods Lupin plants were grown in three-layer stratified soil columns where P was applied at 0 or 330 mg P kg−1 to create a P-deficient or P-sufficient background, and OM, phytate mixed with OM, or perlite was applied to the top or middle layers with or without sterilization. Key Results Non-sterile OM stimulated cluster-root proliferation and root length, and this effect became greater when phytate was supplied in the presence of OM. Both sterile OM and perlite significantly decreased cluster-root formation in the localized layers. The OM position did not change the proportion of total cluster roots to total roots in dry biomass among no-P treatments, but more cluster roots were concentrated in the OM layers with a decreased proportion in other places. Conclusions Localized application of non-sterile OM or phytate plus OM stimulated cluster-root proliferation of L. albus in the localized layers. This effect is predominantly accounted for by P release from breakdown of OM or phytate, but not due to a change in soil density associated with OM. No evidence was found for effects of micro-organisms in OM other than those responsible for P release. PMID:20150198

Use of calcium-containing endodontic sealers as apical barrier in fluid-contaminated wide-open apices.

PubMed

Prati, Carlo; Siboni, Francesco; Polimeni, Antonella; Bossu, Maurizio; Gandolfi, Maria Giovanna

2014-12-30

The sealing of wide-open apex roots is still a challenge and requires the use of apical barrier techniques. The aim was to evaluate ex vivo the sealing and the apical morphology of 3 commercial calcium oxide (CaO)-containing sealers - namely, 2 zinc oxide-based (CRCS and Sealapex) and a calcium silicate MTA-based (TechBiosealer Endo) - placed in wet root canals with artificial wide-open apices.
 Thirty human single-rooted teeth were shaped with Protaper and an artificial open apex (diameter size 110) was created. Each root was inserted in a custom-designed support containing simulated body fluid (Hank's balanced salt solution, HBSS) at the bottom simulating the presence of periapical fluid in the canal. Each sealer (TechBiosealer Endo, CRCS, Sealapex) was compacted to the apical 5 mm and the filled roots stored in HBSS at 37°C. The sealing was evaluated as microinfiltrated fluid since 24 hours up to 6 months using a high-precision digital fluid flow meter. The sealers were also studied for setting time in HBSS, calcium releasing (statistical analysis by 2-way ANOVA followed by Student-Newman-Keuls test, P<0.05) and surface morpho-chemistry by ESEM-EDX and OM analysis.
 All sealers showed a stable seal. TechBiosealer Endo maintained a better seal than the other materials (P<0.05) and ESEM-EDX and OM analyses showed the presence of apatite deposits.
 The clinical use of hydraulic hydrophilic MTA-based sealers can be recommended to stop/reduce the fluid flow rate through the apex. The artificial apical barrier in wet wide apices is a suitable technique able to seal wet root canals.

The impact of volcanic tephra on weathering and soil development of Icelandic Histosols, SE Iceland

NASA Astrophysics Data System (ADS)

Bonatotzky, Theresa; Ottner, Franz; Gísladóttir, Guðrún

2017-04-01

A mixture of poorly decomposed plant remains, crystalline volcanic material and intense aeolian deposition sets Icelandic Histosols apart from other Histosols in the northern hemisphere. They exhibit a unique combination of histic (organic) and andic soil characteristics. Allophane, imogolite and ferrihydrite are common minerals in Icelandic soils while layer silicates are rare. The volcanically active area south of Vatnajökull has received numerous tephra deposits of varying thickness during Holocene. Two distinct tephra layers, the light coloured rhyolitic tephra from the Öræfajökull eruption in AD 1362 and a black basaltic tephra from a Veiðivötn fissure eruption within the Bárðarbunga volcanic system in AD 1477, are well preserved in the soils. This provides a unique opportunity to study weathering behaviour of tephra deposits of different composition and to examine their contrasting mineralogy and impact on soils south of Vatnajökull glacier. The investigated soils can be classified as Histosols with plant residues as parent material and influenced by volcanic ejecta (tephra) and aeolian material. Low pH (H2O) and high organic matter (OM) content are the two dominating factors influencing their weathering behaviour. The soil organic carbon (SOC) content was found to between 16 - 31%. As OM inhibits the formation of amorphous secondary minerals, the clay content in Icelandic soils is generally low while Al-humus complexes are predominant. The soil horizons developed from rhyolitic and basaltic tephra both show differences. Investigations of the mineralogy show small evidence of weathering in the basaltic V1477 tephra, whereas the rhyolitic volcanic ejecta has hardly altered since its formation.

Evaluation of OMNIgene®•SPUTUM-stabilised sputum for long-term transport and Xpert® MTB/RIF testing in Nepal.

PubMed

Maharjan, B; Kelly-Cirino, C D; Weirich, A; Curry, P S; Hoffman, H; Avsar, K; Shrestha, B

2016-12-01

German Nepal TB Project, National Tuberculosis Reference Laboratory, Kathmandu, Nepal. To evaluate whether transporting samples in OMNIgene®•SPUTUM (OM-S) reagent from a peripheral collection site to a central laboratory in Nepal can improve tuberculosis (TB) detection and increase the sensitivity of Xpert® MTB/RIF testing. One hundred sputum samples were split manually. Each portion was assigned to the OM-S group (OM-S added at collection, airline-couriered without cold chain, no other processing required) or the standard-of-care (SOC) group (samples airline-couriered on ice, sodium hydroxide + N-acetyl-L-cysteine processing required at the laboratory). Smear microscopy and Xpert testing were performed. Transport time was 2-13 days. Overall smear results were comparable (respectively 58% and 56% smear-negative results in the OM-S and SOC groups). The rate of smear-positive, Mycobacterium tuberculosis-positive (MTB+) sample detection was identical for both treatment groups, at 95%. More smear-negative MTB+ samples were detected in the OM-S group (17% vs. 13%, P = 0.0655). Sputum samples treated with OM-S can undergo multiday ambient-temperature transport and yield comparable smear and Xpert results to those of SOC samples. Further investigation with larger sample sizes is required to assess whether treating sputum samples with OM-S could increase the sensitivity of Xpert testing in smear-negative samples.

Osteomacs interact with megakaryocytes and osteoblasts to regulate murine hematopoietic stem cell function.

PubMed

Mohamad, Safa F; Xu, Linlin; Ghosh, Joydeep; Childress, Paul J; Abeysekera, Irushi; Himes, Evan R; Wu, Hao; Alvarez, Marta B; Davis, Korbin M; Aguilar-Perez, Alexandra; Hong, Jung Min; Bruzzaniti, Angela; Kacena, Melissa A; Srour, Edward F

2017-12-12

Networking between hematopoietic stem cells (HSCs) and cells of the hematopoietic niche is critical for stem cell function and maintenance of the stem cell pool. We characterized calvariae-resident osteomacs (OMs) and their interaction with megakaryocytes to sustain HSC function and identified distinguishing properties between OMs and bone marrow (BM)-derived macrophages. OMs, identified as CD45 + F4/80 + cells, were easily detectable (3%-5%) in neonatal calvarial cells. Coculture of neonatal calvarial cells with megakaryocytes for 7 days increased OM three- to sixfold, demonstrating that megakaryocytes regulate OM proliferation. OMs were required for the hematopoiesis-enhancing activity of osteoblasts, and this activity was augmented by megakaryocytes. Serial transplantation demonstrated that HSC repopulating potential was best maintained by in vitro cultures containing osteoblasts, OMs, and megakaryocytes. With or without megakaryocytes, BM-derived macrophages were unable to functionally substitute for neonatal calvarial cell-associated OMs. In addition, OMs differentiated into multinucleated, tartrate resistant acid phosphatase-positive osteoclasts capable of bone resorption. Nine-color flow cytometric analysis revealed that although BM-derived macrophages and OMs share many cell surface phenotypic similarities (CD45, F4/80, CD68, CD11b, Mac2, and Gr-1), only a subgroup of OMs coexpressed M-CSFR and CD166, thus providing a unique profile for OMs. CD169 was expressed by both OMs and BM-derived macrophages and therefore was not a distinguishing marker between these 2 cell types. These results demonstrate that OMs support HSC function and illustrate that megakaryocytes significantly augment the synergistic activity of osteoblasts and OMs. Furthermore, this report establishes for the first time that the crosstalk between OMs, osteoblasts, and megakaryocytes is a novel network supporting HSC function.

In vitro cytotoxicity of calcium silicate-containing endodontic sealers.

PubMed

Zhou, Hui-min; Du, Tian-feng; Shen, Ya; Wang, Zhe-jun; Zheng, Yu-feng; Haapasalo, Markus

2015-01-01

The cytotoxicity of 2 novel calcium silicate-containing endodontic sealers to human gingival fibroblasts was studied. EndoSequence BC (Brasseler, Savannah, GA), MTA Fillapex (Angelus Indústria de Produtos Odontológicos S/A, Londrina, PR, Brazil) and a control sealer (AH Plus; Dentsply DeTrey GmbH, Konstanz, Germany) were evaluated. Human gingival fibroblasts were incubated for 3 days both with the extracts from fresh and set materials in culture medium and cultured on the surface of the set materials in Dulbecco-modified Eagle medium. Fibroblasts cultured in Dulbecco-modified Eagle medium were used as a control group. Cytotoxicity was evaluated by flow cytometry, and the adhesion of the fibroblasts to the surface of the set materials was assessed using scanning electron microscopy. The data of cell cytotoxicity were analyzed statistically using a 1-way analysis of variance test at a significance level of P < .05. Cells incubated with extracts from BC Sealer showed higher viabilities at all extract concentrations than cells incubated with extracts from freshly mixed AH Plus and fresh and set MTA Fillapex, esspecially for the high extract concentrations (1:2 and 1:8 dilutions). Extracts from set MTA Fillapex of 2 weeks and older were more cytotoxic than extracts from freshly mixed and 1-week-old cement. With extract concentrations of 1:32 and lower, MTA Fillapex was no longer cytotoxic. After setting, AH Plus was no longer cytotoxic, and the fibroblast cells grew on set AH Plus equally as well as on BC Sealer. BC Sealer and MTA Fillapex, the 2 calcium silicate-containing endodontic sealers, exhibited different cytotoxicity to human gingival fibroblasts. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Multiple enrichment of the Carpathian-Pannonian mantle: Pb-Sr-Nd isotope and trace element constraints

NASA Astrophysics Data System (ADS)

Rosenbaum, Jeffrey M.; Wilson, Marjorie; Downes, Hilary

1997-07-01

Pb isotope compositions of acid-leached clinopyroxene and amphibole mineral separates from spinel peridotite mantle xenoliths entrained in Tertiary-Quaternary alkali basalts from the Carpathian-Pannonian Region of eastern Europe provide important constraints on the processes of metasomatic enrichment of the mantle lithosphere in an extensional tectonic setting associated with recent subduction. Principal component analysis of Pb-Sr-Nd isotope and rare earth element compositions of the pyroxenes is used to identify the geochemical characteristics of the original lithospheric mantle protolith and a spectrum of infiltrating metasomatic agents including subduction-related aqueous fluids and silicate melts derived from a subduction-modified mantle wedge which contains a St. Helena-type (HIMU) plume component. The mantle protolith is highly depleted relative to mid-ocean ridge basalt-source mantle with Pb-Nd-Sr isotope compositions consistent with an ancient depletion event. Silicate melt infiltration into the protolith accounts for the primary variance in the Pb-Sr-Nd isotope compositions of the xenoliths and has locally generated metasomatic amphibole. Infiltration of aqueous fluids has introduced radiogenic Pb and Sr without significantly perturbing the rare earth element signature of the protolith. The Pb isotope compositions of the fluid-modified xenoliths suggest that they reacted with aqueous fluids released from a subduction zone which had equilibrated with sediment derived from an ancient basement terrain. We propose a model for mantle lithosphere evolution consistent with available textural and geochemical data for the xenolith population. The Pb-Sr-Nd isotope compositions of both alkaline mafic magmas and rare, subduction-related, calc-alkaline basaltic andesites from the region provide important constraints for the nature of the asthenospheric mantle wedge and confirm the presence of a HIMU plume component. These silicate melts contribute to the metasomatism of the mantle lithosphere rather than being derived therefrom.

Development of processing diagrams for polymeric die attach adhesives

NASA Astrophysics Data System (ADS)

Hsiung, Jen-Chou

With a processing diagram, one can reduce the effort required to customize curing process conditions for polymeric die attach adhesives. Polymeric die attach adhesives are often cured per the manufacturer's recommendations during initial screening evaluations. In most cases, the recommended cure schedules have to be modified so as to fit differences in process equipment. Unfortunately, the modified cure schedule is usually determined by a trial-and-error method. An aim of our experiments is to understand the curing process of a wide range of polymeric die attach adhesives (conventional, fast, and snap cure adhesives) and to construct a processing diagram, i.e., "Bondability Diagram", so as to define the processing window. Such diagrams should be helpful in determining both the time and cure temperature required to produce high quality bonds. The bondability diagram can be constructed based on fundamental understandings of the phenomena involved in the curing process using a wide variety of tools. Differential Scanning Calorimetry (DSC) is utilized to study the cure kinetics and the extent of reaction. Dynamic Mechanical Analysis (DMA) is used to determine gelation times and melt viscosity under a shear mode. A modified Rheovibron is employed to perform cure characterizations under a tensile mode so that cure stresses could be determined. Thermogravimetric Analysis (TGA) is used to evaluate the outgassing phenomena. Optical Microscopy (OM) is used to detect voids. Results indicate that the cure behaviors of conventional, fast, and snap cure adhesives are different in several respects. The combination of DSC, DMA, TGA, OM, and lap shear test leads to a frame work of developing the bondability diagram concept. The bondability diagram concept provides a foundation for an understanding of the recommended cure schedule and allows one to design their own cure schedule.

Human imprint on archaeological anthroposols: first assessment of combined micromophological, pedological and lipid biomarkers analyses of organic matter

NASA Astrophysics Data System (ADS)

Cammas, Cécilia; Thuy Nguyen Tu, Thanh; Plessis, Marion; Clotuche, Raphaël; Derenne, Sylvie

2013-04-01

Archaeological anthroposol matrix contains significant amounts of fine organic matter (OM), which can give archaeological information. Geoarchaeological studies of OM aim to reveal its origin in order to reconstruct past human activities. Such studies are complex because the nature and the abundance of OM is the result of human activities together with natural processes. Also, MO evolves over time, a process that is not well understood. Combination of complementary approaches may give further insights into human imprint on archaeological anthroposols. For example, micromorphology gives data on in situ activities and pedological processes with the result that components of animal and vegetal origin can be identified but not some amorphous / fibrous material and very fine residues (< ~10 µm). On the other hand, pedological and geochemical analyses of bulk samples are often disconnected from contextual studies. Our work aims to (i) identify morphological and geochemical markers of human activity at different scales, (ii) compare results of different analytical methods to better understand the relation between matrix components and features, chemical properties, and geochemical markers, and (iii) infer relations between pedo-sedimentary history and OM preservation. Two tanning pits in urban craft areas were selected for sampling, as they are likely to contain large amounts of organic matter of vegetal and animal origin. The pit of Saint-Denis (SDN, 10 km at the north of Paris, calcareous alluvium, 13th cAD) was a reference tanning pit. The pit of Famars (FAM, near the Belgian border, luvisols, Roman period) was hypothesized to be a part of the tanning process. To assess preservation of organic components and molecules in relation with pedo-sedimentary context and their potential as biomarkers of human activities, methodology combined micromorphology, pedological analysis (C, N, LOI, P total, organic and inorganic phosphorus) and lipid analysis by GC/MS, lipids having a high preservation potential and containing biomarkers indicative of OM origin. Micromorphological study showed a high amount and diversity of organic components in the two pits. At the SDN pit, the interpretation of tanning (liming) was supported by the presence of scarce fragments of lime with calcitic hairs pseudomorphoses. Plant remains and bone fragments were identified, but red fibrous and yellow amorphous material were not. At the FAM pit, bones and coprolithic material were scarce, but there were abundant vegetal remains such as decaying and burnt fragments, as well as siliceous skeletons. Initial results of organic chemistry show that lipids were preserved (0,13 % for SDN, 0,09 % for FAM), and that lipids of vegetal origin were dominant in the two samples. At SDN, both plant and faecal material biomarkers were identified in the form of various sterols and coprostanol, respectively. Lipids extracted from FAM included ubiquitous compounds as well as plant biomarkers, but no faecal markers. The structure of several compounds is still to be elucidated. However, initial results may suggest that vegetal imprint in thin section and in lipid analysis can be correlated. For animal remains, the two methods seem to lead to different but complementary conclusions; the difference noted for inferred source material will be investigated in term of cultural and contextual origin.

Photophysical and antibacterial properties of complex systems based on smectite, a cationic surfactant and methylene blue.

PubMed

Donauerová, Alena; Bujdák, Juraj; Smolinská, Miroslava; Bujdáková, Helena

2015-10-01

Solid or colloidal materials with embedded photosensitizers are promising agents from the medical or environmental perspective, where the direct use of photoactive solutions appears to be problematic. Colloids based on layered silicates of the saponite (Sap) and montmorillonite (Mon) type, including those modified with dodecylammonium cations (C12) and photosensitizer--methylene blue (MB) were studied. Two representatives of bacteria, namely Enterobacter cloacae and Escherichia coli, were selected for this work. A spectral study showed that MB solutions and also colloids with Sap including C12 exhibited the highest photoactivities. The antimicrobial properties of the smectite colloids were not directly linked to the photoactivity of the adsorbed MB cations. They were also influenced by other parameters, such as light vs. dark conditions, the spectrum, power and duration of the light used for the irradiation; growth phases, and the pre-treatment of microorganisms. Both the photoactivity and antimicrobial properties of the colloids were improved upon pre-modification with C12. Significantly higher antimicrobial properties were observed for the colloids based on Mon with MB in the form of molecular aggregates without significant photoactivities. The MB/Mon colloids, both modified and non-modified with C12 cations, exhibited higher antimicrobial effects than pure MB solution. Besides the direct effect of photosensitization, the surface properties of the silicate particles likely played a crucial role in the interactions with microorganisms. Copyright © 2015 Elsevier B.V. All rights reserved.

Impact of pyrogenic organic matter decomposition and induced priming effect on soil C budget.

NASA Astrophysics Data System (ADS)

Maestrini, Bernardo; Abiven, Samuel

2014-05-01

Pyrogenic organic matter (PyOM) results from the incomplete combustion of biomass and may contribute to constitute an important fraction of soil C in forest and agricultural soils, in the form of charcoal (produced by wildfires) or biochar (anthropogenic). Although many evidences exist on the long mean residence time of PyOM there is still a large uncertainty on PyOM loss processes and rate and on possible induced priming effect on non-PyOM. Therefore determining PyOM mineralization rate, loss processes and possible induced priming effect on soil organic matter decomposition are key issues to understand the impact of PyOM on the carbon (C) cycle. We investigated the impact of PyOM on soil C budget by combining results from three independent studies: (i) a field study to investigate PyOM mineralization rate and the relative importance of PyOM loss processes, (ii) a PyOM and soil incubation experiment to correlate C and N mineralization rates, (iii) a review of the priming effect induced by PyOM on soil organic C. We employed 13C labelled pinewood-derived PyOM for the field experiment and 13C labelled ryegrass-derived PyOM in the incubation experiment to trace PyOM losses. In the field experiment it was observed that: (i) Pyrolysis process reduced pinewood decomposition by a factor of 60, (ii) leaching and translocation of fresh PyOM along the soil profile were negligible compared to losses as CO2. In the incubation experiment we found that ryegrass induced a two phase priming effect on native soil organic matter, with a positive priming effect followed by a negative priming effect phase, we also found that ryegrass-derived PyOM decomposition was much slower than pinewood one. The different decomposition rate results probably from the different aromaticity of the two PyOM together with the different set-up of the two experiments. Both the incubation experiment and the meta-analysis revealed that PyOM may induce a two-phase priming effect on native soil organic matter decomposition: positive on the short term and negative on the long term. The meta-analysis showed that that positive priming effect is induced mostly on the native soil organic matter on the short term and by PyOM characterised by a low C content. This result was not confirmed on the freshly added organic matter. We believe that the presence of a labile fraction in PyOM may induce positive priming effect on the short term by mean of co-metabolism. We conclude that PyOM chemical composition and feedstock play an important role in predicting PyOM mineralization rate, and that on the short term PyOM may induce a positive priming effect therefore decreasing the abatement potential of PyOM as a C-sink.

The Incidence, Prevalence and Burden of OM in Unselected Children Aged 1 to 8 Years Followed by Weekly Otoscopy through the “Common Cold” Season

PubMed Central

Mandel, Ellen M.; Doyle, William J.; Winther, Birgit; Alper, Cuneyt M.

2008-01-01

Background There is a continuing interest in defining the incidence, prevalence and burden of otitis media (OM) in the individual and population for purposes of assigning “risk factors”. Often overlooked in past studies are the contributions of cold-like illnesses (CLIs) and sampling interval to those estimates. Objective Describe the incidence of symptomatic (AOM) and asymptomatic (OME) OM, the prevalence of OM, the contribution of CLI incidence, burden and other OM “risk factors” to the incidence and burden of OM, and the effect of sampling interval on those measures in children. Methods 148 children (74 male; 131 white, aged 1.0–8.6 years) were followed from November 1 to April 30 by weekly pneumatic otoscopy to diagnose OM presence/absence and by daily parental diary to assign CLI episodes. Data for previously identified OM “risk factors” were collected on 127. Results were summarized using standard measures of incidence, prevalence and burden, and multiple-regression techniques were used to identify OM “risk factors”. Results The basal OM prevalence was 20% with peaks in December and March and the temporal pattern was correlated with CLI prevalence. The incidence of OME (per 27232 child-days) was 317, AOM was 74 and CLI was 456. The seasonal pattern of AOM and OME incidences tracked and was correlated with that for CLIs. New OM episodes were usually of short duration (≤7 days in 40%, ≤4 weeks in 75–90%) and the usual OM burden was low (median=12%). OM and breastfeeding histories and CLI incidence/prevalence were significant predictors of OME and AOM incidence and OM burden. Longer sampling intervals were less efficient in capturing AOM and OME durations and incidences, but not OM burden. Conclusions These results demonstrate a high incidence and prevalence of OM, most OM episodes were of short duration and longer sampling intervals introduced biases into some parameter estimates. There was a significant relationship between OM and CLI incidence, prevalence and burden suggesting that CLI experience should be controlled for in assessing independent “risk factors” for AOM and OME. PMID:18272237

White-rot fungal response to fresh and photolytically-weathered pyrogenic organic matter

NASA Astrophysics Data System (ADS)

Gibson, C. D.; Berry, T. D.; Wang, R.; Bird, J. A.; Filley, T. R.

2013-12-01

Pyrogenic organic matter (PyOM or biochar) is the product of the incomplete combustion of biomass. A better understanding of the microbial-mediated degradation of PyOM is critical to assess its role in soil C sequestration and to serve as an agricultural amendment. Recent studies have shown that PyOM additions can prime native soil C but results have been inconsistent, with studies reporting no effect, an increase, or decrease in C mineralization. This study investigated the ability of saprotrophic white-rot fungus, Trametes versicolor, to decompose an unaltered 'fresh' PyOM and a photo-oxidized PyOM. In addition, we measured PyOM-induced priming effects on the mineralization of malt extract agar media (MEA). Enriched (13C) Pinus banksiana-derived PyOM, produced at 450oC under N2, was added fresh and after 4 weeks exposure to 254 nm light to MEA. Vials containing the various types of media were then monitored for CO2 evolution and oxidative enzyme activity. We found that MEA C respired was stimulated (positive priming) by photolyzed PyOM and was inhibited with fresh PyOM addition (negative priming) relative to controls. Vetryl alcohol addition, a laccase production stimulant, resulted in less activity in the presence of PyOM compared with a control, indicating PyOM may disrupt enzyme induction processes. Loss of PyOM-13CO2 was 0.2% (× 0.001) for fresh PyOM and 1.2% (×0.001) for photolyzed PyOM C during 10 weeks averaged across media treatments. While MEA C mineralization decreased after fresh PyOM addition, both oxidative (laccase and manganese peroxidase) and hydrolytic (β glucosidase) enzyme production increased with fresh PyOM in the absence of veratryl alcohol. However, there was a decrease in its presence. These results suggest that the physiological response of this common wood decay fungus to PyOM is complex and responsive to enzymatic triggers but that PyOM itself can act to promote or suppress overall litter or soil decay by fungi.

Note: Making tens of centimeter long uniform microfluidic channels using commercial glass pipette

NASA Astrophysics Data System (ADS)

Ou, Neil; Lee, Huang-Ming; Wu, Jong-Ching

2018-03-01

Producing microchannels with diameters between 10 and 20 μm and with lengths in the tens of centimeters is reported. The method can be modified to obtain diameters as narrow as 350 nm. Length-to-diameter aspect ratios that surpass 104 can be produced for a fraction of current production costs. The controllable channel is produced by applying a flame to the narrow end of a commercial pipette that is made from a soda-lime silicate. In combination with a pulling mechanism, applying heat to the composite material lengthens the pipette in a highly uniform way. Given that the materials and methods in this research are cost-effective when compared to femtosecond laser micromachining on 2D silicon-based surfaces, further research into producing microchannels from soda-lime silicates may revolutionize access to 3D controllable microchannels.

Bonelike apatite formation on ethylene-vinyl alcohol copolymer modified with silane coupling agent and calcium silicate solutions.

PubMed

Oyane, Ayako; Kawashita, Masakazu; Nakanishi, Kazuki; Kokubo, Tadashi; Minoda, Masahiko; Miyamoto, Takeaki; Nakamura, Takashi

2003-05-01

An ethylene-vinyl alcohol copolymer (EVOH) was treated with a silane coupling agent and calcium silicate solutions, and then soaked in a simulated body fluid (SBF) with ion concentrations approximately equal to those of human blood plasma. A smooth and uniform bonelike apatite layer was successfully formed on both the EVOH plate and the EVOH-knitted fibers in SBF within 2 days. Part of the structure of the resulting apatite-EVOH fiber composite was similar to that of natural bone. If this kind of composite can be fabricated into a three-dimensional structure similar to natural bone, the resultant composite is expected to exhibit both mechanical properties analogous to those of natural bone and bone-bonding ability. Hence, it has great potential as a bone substitute. Copyright 2003 Elsevier Science Ltd.

The glycan keratan sulfate in inner ear crystals

NASA Technical Reports Server (NTRS)

Fermin, C. D.; Martin, D. S.; Li, Y. T.; Li, S. C.

1995-01-01

The otoconial matrix (OM) of chicks (Gallus domesticus) inner ear was analyzed. Histochemically the OM was reacted with phosphotungstic acid (PTA) and immunohistochemically with the monoclonal antibody antikeratan sulfate (antiKS). The OM was digested with the enzyme endo-beta-galactosidase (E beta Galase) or separated by 1D and 2D gel electrophoresis. PTA which reacts with glycoproteins precipitated the OM, suggesting that the OM contains glycoproteins. A central core in each crystal had no PTA staining, suggesting that the core lacked glycoproteins. Anti KS antibody stained the OM with increased density in older embryos as determined by color thresholding. E beta Galase, which cleaves the lactosamine repeating units in KS, decreased the immunostain by 30% in the OM and by 20% in the cartilage. The OM from the utricle, saccule and macula lagena contained similar molecular weight bands. Five dense bands in the OM were less dense in tissue and blood controls, suggesting that such bands are enriched in the OM. Isoelectric focusing of the OM showed a negatively charged high molecular weight smear not present in blood and faint in tissue controls. The high affinity of the OM for the cationic PTA stain, the strong immunohistochemical reaction of the OM with anti KS antibody and high molecular weight negative smear in 2D gels taken together suggest that: a) the OM contains large amounts of glycoproteins and glycans, one of which is keratan sulfate, because its immuno stain with antiKS antibody was decreased by the enzyme E beta Galase, b) the utricle, saccule and macula lagena may have similar composition, and c) the concentration of KS may increase gradually until complete mineralization of the OM is reached.

An Update on Nearshore Berms in the Corps of Engineers: Recent Projects and Future Needs

DTIC Science & Technology

2012-01-01

NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c . THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed...navigation channel influence, b. timing of placement which could be seasonally dependent, c . depth of berm in an active location, and d. the overall...NR HB2 HB1 AG LI SI BB Active % D iff fr om O ut er D O C L im it % Difference from Inner DOC Limit Active Stable Modified from Hands and Allison

20 CFR 229.52 - Age reduction when a reduced age O/M is effective before DIB O/M.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Age reduction when a reduced age O/M is effective before DIB O/M. 229.52 Section 229.52 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS... Minimum Rate § 229.52 Age reduction when a reduced age O/M is effective before DIB O/M. If an employee...

20 CFR 229.52 - Age reduction when a reduced age O/M is effective before DIB O/M.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Age reduction when a reduced age O/M is effective before DIB O/M. 229.52 Section 229.52 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS... Minimum Rate § 229.52 Age reduction when a reduced age O/M is effective before DIB O/M. If an employee...

Variations in the OM/OC ratio of urban organic aerosol next to a major roadway.

PubMed

Brown, Steven G; Lee, Taehyoung; Roberts, Paul T; Collett, Jeffrey L

2013-12-01

Understanding the organic matter/organic carbon (OM/OC) ratio in ambient particulate matter (PM) is critical to achieve mass closure in routine PM measurements, to assess the sources of and the degree of chemical processing organic aerosol particles have undergone, and to relate ambient pollutant concentrations to health effects. Of particular interest is how the OM/OC ratio varies in the urban environment, where strong spatial and temporal gradients in source emissions are common. We provide results of near-roadway high-time-resolution PM1 OM concentration and OM/OC ratio observations during January 2008 at Fyfe Elementary School in Las Vegas, NV, 18 m from the U.S. 95 freeway soundwall, measured with an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-AMS). The average OM/OC ratio was 1.54 (+/- 0.20 standard deviation), typical of environments with a low amount of secondary aerosol formation. The 2-min average OM/OC ratios varied between 1.17 and 2.67, and daily average OM/OC ratios varied between 1.44 and 1.73. The ratios were highest during periods of low OM concentrations and generally low during periods of high OM concentrations. OM/OC ratios were low (1.52 +/- 0.14, on average) during the morning rush hour (average OM = 2.4 microg/m3), when vehicular emissions dominate this near-road measurement site. The ratios were slightly lower (1.46 +/- 0.10) in the evening (average OM = 6.3 microg/m3), when a combination of vehicular and fresh residential biomass burning emissions was typically present during times with temperature inversions. The hourly averaged OM/OC ratio peaked at 1.66 at midday. OM concentrations were similar regardless of whether the monitoring site was downwind or upwind of the adjacent freeway throughout the day, though they were higher during stagnant conditions (wind speed < 0.5 m/sec). The OM/OC ratio generally varied more with time of day than with wind direction and speed.

Co-settling of Chromite and Sulfide Melt Droplets and Trace Element Partitioning between Sulfide and Silicate Melts

NASA Astrophysics Data System (ADS)

Manoochehri, S.; Schmidt, M. W.; Guenther, D.

2013-12-01

Gravitational settling of immiscible, dense sulfide melt droplets together with other cumulate phases such as chromite, combined with downward percolation of these droplets through a cumulate pile, is thought to be one of the possible processes leading to the formation of PGE rich sulfide deposits in layered mafic intrusions. Furthermore some chromitite seams in the Merensky Reef (Bushveld Complex) are considered to be acting as a filter or barrier for further downward percolation of sulfide melts into footwall layers. To investigate the feasibility of such mechanical processes and to study the partitioning behavior of 50 elements including transition metals and REEs (but not PGEs) between a silicate and a sulfide melt, two separate series of high temperature (1250-1380 °C) centrifuge-assisted experiments at 1000 g, 0.4-0.6 GPa were conducted. A synthetic silicate glass with a composition representative of the parental magma of the Bushveld Complex (~ 55 wt% SiO2) was mixed with pure FeS powder. For the first series of experiments, 15 or 25 wt% natural chromite with average grain sizes of ~ 5 or 31 μm were added to a mixture of silicate glass and FeS (10 wt%) adding 1 wt% water. For the second series, a mixture of the same glass and FeS was doped with 50 trace elements. These mixtures were first statically equilibrated and then centrifuged. In the first experimental series, sulfide melt droplets settled together with, but did not segregate from chromite grains even after centrifugation at 1000 g for 12 hours. A change in initial chromite grain size and proportions didn't have any effect on segregation. Without chromite, the starting mixture resulted in the formation of large sulfide melt pools together with finer droplets still disseminated through the silicate glass and both at the bottom of the capsule. The incomplete segregation of sulfide melt is interpreted as being due to high interfacial energies between sulfide and silicate melts/crystals which hinder both, the nucleation of newly formed sulfide droplets and the interconnectivity of separate droplets. The interfacial energies between sulfide melt and silicate or oxide crystals is even higher than for silicate melt, consequently in experiments with chromite, sulfide segregation is even more hindered. Partition coefficients of 50 elements between a sulfide and a silicate melt are determined as a function of differing temperature between 1250 - 1380 °C. As a proxy to investigate the bond strength of network modifier cations, the relation between the partition coefficients and ionic potentials of different groups of elements has been determined.

Stable isotope ratios of nonexchangeable hydrogen in organic matter of soils and plants along a 2100-km climosequence in Argentina: New insights into soil organic matter sources and transformations?

NASA Astrophysics Data System (ADS)

Ruppenthal, Marc; Oelmann, Yvonne; del Valle, Héctor Francisco; Wilcke, Wolfgang

2015-03-01

The quantitative contribution of shoot and root organic matter (OM) to the soil carbon (C) stock is still unknown, mainly because of methodological restrictions. The novel measurement of the nonexchangeable hydrogen (H) stable isotope ratio (δ2Hn) in bulk OM provides new opportunities to investigate the sources of soil C and its climate-dependent transformations. Our objectives were to test whether (I) there are systematic differences between δ2Hn values of aboveground and belowground plant OM and (II) δ2Hn values of litter and soil OM relate to climate and plant OM source δ2Hn signals. We determined δ2Hn values of bulk shoot, root, litter and demineralized soil OM from 20 sampling sites along a 2100-km climosequence from the Argentinean Pampas to the Patagonian steppe. The δ2Hn values of shoot and litter OM correlated closely with the aridity index (r = -0.83, p < 0.001 and r = -0.78, p < 0.001, respectively) because of H isotope fractionation during aridity-controlled transpiration in shoots. In contrast, δ2Hn values of root and soil OM showed a close correlation with modeled mean annual δ2H values of local precipitation (r = 0.91, p < 0.001 and r = 0.97, p < 0.001, respectively, root mean square error of 8.2‰ and 7.2‰, respectively) and thus mean annual temperature (r = 0.80, p < 0.001 and r = 0.88, p < 0.001, respectively). δ2Hn values of shoot and root OM differed markedly (no linear correlation) most likely because of biosynthetic exchange of C-bound H with ambient water in the roots. δ2Hn values of root and demineralized soil OM, however, were closely correlated (r = 0.91, p < 0.001) with a constant offset irrespective of climatic conditions, suggesting that root OM was a more important source of soil OM than shoot OM. A possible contribution of shoot OM to soil OM could only be explained if shoot OM underwent biosynthetic exchange of C-bound H with ambient water in soil during microbial and fungal decomposition. This mechanism is known for substrates processed through the microbial and fungal glycolysis-gluconeogenesis metabolic pathways. Our modeling suggested that the δ2Hn signature of soil OM is best explained under the assumption that root OM is the predominant source of soil OM, rather than shoot and litter OM.

Osteomyelitis: a descriptive study.

PubMed

Prieto-Pérez, Laura; Pérez-Tanoira, Ramón; Petkova-Saiz, Elizabet; Pérez-Jorge, Concepción; Lopez-Rodriguez, Cristina; Alvarez-Alvarez, Beatriz; Polo-Sabau, Jorge; Esteban, Jaime

2014-03-01

To analyze the incidence and clinical-microbiological characteristics of osteomyelitis (OM) in a tertiary Spanish hospital. All cases diagnosed with OM between January 2007 and December 2010 were retrospectively reviewed. The variables examined include epidemiological characteristics, risk factors, affected bone, radiographic changes, histology, microbiological culture results, antibiotic treatment, and the need for surgery. Sixty-three cases of OM were diagnosed. Twenty-six patients (41.3%) had acute OM whereas 37 patients (58.7%) were classified as chronic OM. OM may result from haematogenous or contiguous microbial seeding. In this group, 49 patients (77.8%) presented with OM secondary to a contiguous source of infection and 14 patients had hematogenous OM (22.2%). Staphylococcus aureus was the most commonly found microorganism. OM mainly affected patients with risk factors related to the presence of vascular diseases. Antibiotic treatment must be guided by susceptibility patterns of individual microorganisms, although it must be performed together with surgery in most of the cases.

Characterization of outer membranes isolated from Treponema pallidum, the syphilis spirochete.

PubMed

Radolf, J D; Robinson, E J; Bourell, K W; Akins, D R; Porcella, S F; Weigel, L M; Jones, J D; Norgard, M V

1995-11-01

Previous freeze-fracture electron microscopy (EM) studies have shown that the outer membrane (OM) of Treponema pallidum contains sparse transmembrane proteins. One strategy for molecular characterization of these rare OM proteins involves isolation of T. pallidum OMs. Here we describe a simple and extremely gentle method for OM isolation based upon isopycnic sucrose density gradient ultracentrifugation of treponemes following plasmolysis in 20% sucrose. Evidence that T. pallidum OMs were isolated included (i) the extremely low protein/lipid ratio of the putative OM fraction, (ii) a paucity of antigenic and/or biochemical markers for periplasmic, cytoplasmic membrane, and cytosolic compartments, and (iii) freeze-fracture EM demonstrating that the putative OMs contained intramembranous particles highly similar in size and density to those in native T. pallidum OMs. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that the OMs contained a relatively small number of treponemal proteins, including several which did not appear to correspond to previously characterized T. pallidum antigens. Interestingly, these candidate rare OM proteins reacted poorly with syphilitic sera as determined by both conventional immunoblotting and enhanced chemiluminescence. Compared with whole cells, T. pallidum OMs were deficient in cardiolipin, the major lipoidal antigen reactive with antibodies in syphilitic sera. Also noteworthy was that other lipoidal constituents of OMs, including the recently discovered glycolipids, did not react with human syphilitic sera. These latter observations suggest that the poor antigenicity of virulent T. pallidum is a function of both the lipid composition and the low protein content of its OM.

OMNIgene.SPUTUM suppresses contaminants while maintaining Mycobacterium tuberculosis viability and obviates cold-chain transport.

PubMed

Azam, Khalide; Cadir, Nureisha; Madeira, Carla; Gillespie, Stephen H; Sabiiti, Wilber

2018-01-01

Tuberculosis (TB) diagnostics are centralised, requiring long-distance transportation of specimens in most resource-limited settings. We evaluated the ability of OMNIgene.SPUTUM (OM-S) to obviate cold-chain transport of TB specimens. A two-arm (same-day and after 5 days sample processing) study was conducted to assess contamination rates and Mycobacterium tuberculosis viability in OM-S-treated samples against the standard decontamination procedure (SDP) in Mozambique, using Lowenstein Jensen (LJ) and mycobacterial growth indicator tube (MGIT) culture and molecular bacterial load assay. 270 specimens were processed using OM-S and SDP in same-day and 5-day arms. Contamination was lower in OM-S-treated than SDP-treated cultures: 12% versus 15% and 2% versus 27% in the same-day and 5-day arms, respectively. M. tuberculosis recovery in OM-S-treated LJ cultures was 10% and 56% higher in the same-day and 5-day arms, respectively, than SDP-treated cultures, but lower in MGIT (52% and 28% lower in the same-day and 5-day arms, respectively). M. tuberculosis viable count was 1log estimated CFU·mL -1 lower in 5-day OM-S-treated sputa. OM-S was more effective at liquefying sputum with a shorter sample processing time: 22 min for culture. OM-S is simple to use and has demonstrated a high potency to suppress contaminants, maintenance of viability at ambient temperatures and higher M. tuberculosis recovery, particularly in the solid LJ cultures. Optimisation of OM-S to achieve higher MGIT culture positivity and shorter time to result will increase its application and utility in the clinical management of TB.

OMNIgene.SPUTUM suppresses contaminants while maintaining Mycobacterium tuberculosis viability and obviates cold-chain transport

PubMed Central

Azam, Khalide; Cadir, Nureisha; Madeira, Carla; Gillespie, Stephen H.; Sabiiti, Wilber

2018-01-01

Tuberculosis (TB) diagnostics are centralised, requiring long-distance transportation of specimens in most resource-limited settings. We evaluated the ability of OMNIgene.SPUTUM (OM-S) to obviate cold-chain transport of TB specimens. A two-arm (same-day and after 5 days sample processing) study was conducted to assess contamination rates and Mycobacterium tuberculosis viability in OM-S-treated samples against the standard decontamination procedure (SDP) in Mozambique, using Lowenstein Jensen (LJ) and mycobacterial growth indicator tube (MGIT) culture and molecular bacterial load assay. 270 specimens were processed using OM-S and SDP in same-day and 5-day arms. Contamination was lower in OM-S-treated than SDP-treated cultures: 12% versus 15% and 2% versus 27% in the same-day and 5-day arms, respectively. M. tuberculosis recovery in OM-S-treated LJ cultures was 10% and 56% higher in the same-day and 5-day arms, respectively, than SDP-treated cultures, but lower in MGIT (52% and 28% lower in the same-day and 5-day arms, respectively). M. tuberculosis viable count was 1log estimated CFU·mL−1 lower in 5-day OM-S-treated sputa. OM-S was more effective at liquefying sputum with a shorter sample processing time: 22 min for culture. OM-S is simple to use and has demonstrated a high potency to suppress contaminants, maintenance of viability at ambient temperatures and higher M. tuberculosis recovery, particularly in the solid LJ cultures. Optimisation of OM-S to achieve higher MGIT culture positivity and shorter time to result will increase its application and utility in the clinical management of TB. PMID:29479537

Manganese dioxide as a new cathode catalyst in microbial fuel cells

NASA Astrophysics Data System (ADS)

Li, Xiang; Hu, Boxun; Suib, Steven; Lei, Yu; Li, Baikun

This study focused on manganese oxides with a cryptomelane-type octahedral molecular sieve (OMS-2) structure to replace platinum as a cathode catalyst in microbial fuel cells (MFCs). Undoped (ud-OSM-2) and three catalysts doped with cobalt (Co-OMS-2), copper (Cu-OMS-2), and cerium (Ce-OMS-2) to enhance their catalytic performances were investigated. The novel OMS-2 cathodes were examined in granular activated carbon MFC (GACMFC) with sodium acetate as the anode reagent and oxygen in air as the cathode reagent. The results showed that after 400 h of operation, the Co-OMS-2 and Cu-OMS-2 exhibited good catalytic performance in an oxygen reduction reaction (ORR). The voltage of the Co-OMS-2 GACMFC was 217 mV, and the power density was 180 mW m -2. The voltage of the Cu-OMS-2 GACMFC was 214 mV and the power density was 165 mW m -2. The internal resistance (R in) of the OMS-2 GACMFCs (18 ± 1 Ω) was similar to that of the platinum GACMFCs (17 Ω). Furthermore, the degradation rates of organic substrates in the OMS-2 GACMFCs were twice those in the platinum GACMFCs, which enhance their wastewater treatment efficiencies. This study indicated that using OMS-2 manganese oxides to replace platinum as a cathodic catalyst enhances power generation, increases contaminant removal, and substantially reduces the cost of MFCs.

Fluoride-containing nanoporous calcium-silicate MTA cements for endodontics and oral surgery: early fluorapatite formation in a phosphate-containing solution.

PubMed

Gandolfi, M G; Taddei, P; Siboni, F; Modena, E; Ginebra, M P; Prati, C

2011-10-01

To test the chemical-physical properties and apatite-forming ability of experimental fluoride-doped calcium silicate cements designed to create novel bioactive materials for use in endodontics and oral surgery. A thermally treated calcium silicate cement (wTC) containing CaCl(2) 5%wt was modified by adding NaF 1%wt (FTC) or 10%wt (F10TC). Cements were analysed by environmental scanning electron microscopy with energy-dispersive X-ray analysis, IR and micro-Raman spectroscopy in wet conditions immediately after preparation or after ageing in a phosphate-containing solution (Dulbecco's phosphate-buffered saline). Calcium and fluoride release and pH of the storage solution were measured. The results obtained were analysed statistically (Tukey's HSD test and two-way anova). The formation of calcium phosphate precipitates (spherulites) was observed on the surface of 24 h-aged cements and the formation of a thick bone-like B-type carbonated apatite layer (biocoating) on 28 day-aged cements. The rate of apatite formation was FTC>F10TC>wTC. Fluorapatite was detected on FTC and F10TC after 1 day of ageing, with a higher fluoride content on F10TC. All the cements released calcium ions. At 5 and 24 h, the wTC had the significantly highest calcium release (P<0.001) that decreased significantly over the storage time. At 3-28 days, FTC and F10TC had significantly higher calcium release than wTC (P<0.05). The F10TC had the significantly highest fluoride release at all times (P<0.01) that decreased significantly over storage time. No significant differences were observed between FTC and wTC. All the cements had a strong alkalinizing activity (OH(-) release) that remained after 28 days of storage. The addition of sodium fluoride accelerated apatite formation on calcium silicate cements. Fluoride-doped calcium silicate cements had higher bioactivity and earlier formation of fluorapatite. Sodium fluoride may be introduced in the formulation of mineral trioxide aggregate cements to enhance their biological behaviour. F-doped calcium silicate cements are promising bone cements for clinical endodontic use. © 2011 International Endodontic Journal.

Phenylethynyl Silsesquioxanes: Monomer Synthesis, Characterization,Thermolysis and Thermal Properties

DTIC Science & Technology

2016-12-14

thermal, mechanical and surface properties of many polymeric systems. A useful analogy is that a POSS is nano-sized particle of silica solubilzed...with organic modifiers (RSiO1.5)n; the organic periphery determines how well the POSS can interact with any host polymer , while the siliceous core adds...various materials affects polymer properties. Herein is reported a synthesis strategy to produce POSS-containing, thermosetting phenylethynyls to yield

International Symposium on Polymer Electrolytes (1st)

DTIC Science & Technology

1987-06-01

second order transitions, and chemical stability, e.g. dehydration or chemical decomposition . This is a powerful technique which can be used...References (M.Watanabe et. al) 1) Polym.J., 15, 65, 175 (1983). 2) Polym.J., 16, 711 (1984); 17, 549 (1985). 3) Macromolecules, 18, 1945 (1985). 4) Nippon...material is an organically modified silicate which gives, alter hydrolysis and condensation, an organic-inorganic glass. The silica network gives good

International Collaboration Program on Innovative Chemical Processing of Superior Electronic and Optical Materials

DTIC Science & Technology

1994-07-01

Chem. Phys. Lett., 153 (1988) 351 . l -11- AFOSR 91-0317 Dense Sodium Borosilicate New Organically-Modified Glass as Matrix Silicate (Ormosil) as Matrix... GelI Oxidation in 02 (450’C, 24 hrs) SCdO-doped Gel Sulphuration in H2S (1 10"C, 24 hrs) CdS-doped Gel I Densification (540’C, 6 hrs) CdS in Sodium

Influence of CuO and ZnO addition on the multicomponent phosphate glasses: Spectroscopic studies

NASA Astrophysics Data System (ADS)

Szumera, Magdalena; Wacławska, Irena; Sułowska, Justyna

2016-06-01

The spectra of phosphate-silicate glasses from the P2O5-SiO2-K2O-MgO-CaO system modified with the addition of CuO or ZnO have been studied by means of FTIR, Raman and 31P MAS NMR spectroscopy. All glasses were synthesized by the conventional melt-quenching technique and their homogeneous chemical composition was controlled and confirmed. By using the aforementioned research techniques, the presence of structural units with various degrees of polymerization was shown in the structure of analyzed phosphate-silicate glasses: Q3, Q2, Q1 and Q0. It was found that an increase in the content of CuO or ZnO in the composition of analyzed glasses, which are introduced at the expense of decreasing amounts of CaO and MgO, has a different influence on the phospho-oxygen network. It was shown that copper ions cause its gradual polymerization, while zinc ions cause its depolymerization. At the same time, polymerization of the silico-oxygen subnetwork was found. Additionally, in the case of glasses containing increasing amounts of ZnO, a change of the role of zinc ions in the vitreous matrix was confirmed (from the modifier to a structure-forming component).

Evaluation of certain food additives and contaminants.

PubMed

2013-01-01

This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives and a food contaminant with a view to concluding as to safety concerns and to preparing specifications for identity and purity. The first part of the report contains a general discussion of the principles governing the toxicological evaluation of and assessment of dietary exposure to food additives. A summary follows of the Committee's evaluations of technical, toxicological and dietary exposure data for seven food additives (advantame; glucoamylase from Trichoderma reesei expressed in Trichoderma reesei; glycerol ester of gum rosin; glycerol ester of tall oil rosin; glycerol ester of wood rosin; nisin; and octenyl succinic acid modified gum arabic) and an assessment of dietary exposure to cadmium from cocoa and cocoa products. Specifications for the following food additives were revised: annatto extracts (solvent-extracted bixin and solvent-extracted norbixin); Benzoe tonkinensis; food additives containing aluminium and/or silicon; mineral oil (medium viscosity); modified starches; paprika extract; phosphates (analytical methods for the determination of phosphorus and revision of specifications); 3-phytase from Aspergillus niger expressed in Aspergillus niger; potassium aluminium silicate; and potassium aluminium silicate-based pearlescent pigments. Annexed to the report are tables summarizing the Committee's recommendations for dietary exposures to and toxicological evaluations of the food additives and contaminant considered.

Omethoate treatment mitigates high salt stress inhibited maize seed germination.

PubMed

Yang, Kejun; Zhang, Yifei; Zhu, Lianhua; Li, Zuotong; Deng, Benliang

2018-01-01

Omethoate (OM) is a highly toxic organophophate insecticide, which is resistant to biodegradation in the environment and is widely used for pest control in agriculture. The effect of OM on maize seed germination was evaluated under salt stress. Salt (800mM) greatly reduced germination of maize seed and this could be reversed by OM. Additionally, H 2 O 2 treatment further improved the effect of OM on seed germination. Higher H 2 O 2 content was measured in OM treated seed compared to those with salt stress alone. Dimethylthiourea (DTMU), a specific scavenger of reactive oxygen species (ROS), inhibited the effect of OM on seed germination, as did IMZ (imidazole), an inhibitor of NADPH oxidase. Abscisic acid (ABA) inhibited the effect of OM on seed germination, whereas fluridone, a specific inhibitor of ABA biosynthesis, enhanced the effect of OM. Taken together, these findings suggest a role of ROS and ABA in the promotion of maize seed germination by OM under salt stress. Copyright © 2017 Elsevier Inc. All rights reserved.

Experimental evidence of {alpha}-olefin readsorption in Fischer-Tropsch synthesis on ruthenium-supported ETS-10 titanium silicate catalysts

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

Bianchi, C.L.; Ragaini, V.

1997-05-01

Fischer-Tropsch synthesis seems to develop the following two consecutive paths: a primary process that involves the formation of {alpha}-olefin products and a secondary process leading to the production of branched isomers and paraffins and requiring the readsorption of primary {alpha}-olefin products. It was already shown by Iglesia et al. that such readsorption steps are of fundamental importance for Ru catalysts and that they occur due to the slow diffusive removal of {alpha}-olefins when the molecular size increases, this resulting in a long intraparticle residence time. In the present paper {alpha}-olefins readsorption was enhanced by changing the metal distribution inside themore » pores of a titanium silicate (ETS-10), modified by ion exchange with alkali metal ions, used as a support for Ru-based catalysts. 24 refs., 5 figs., 3 tabs.« less

Effects of ion irradiation on the mechanical properties of SiNa wO xC yH z sol-gel derived thin films

NASA Astrophysics Data System (ADS)

Lucca, D. A.; Qi, Y.; Harriman, T. A.; Prenzel, T.; Wang, Y. Q.; Nastasi, M.; Dong, J.; Mehner, A.

2010-10-01

A study of the effects of ion irradiation of hybrid organic/inorganic modified silicate thin films on their mechanical properties is presented. NaOH catalyzed SiNa wO xC yH z thin films were synthesized by sol-gel processing from tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) precursors and spin-coated onto Si substrates. After drying at 300 °C, the films were irradiated with 125 keV H + or 250 keV N 2+ at fluences ranging from 1 × 10 14 to 2.5 × 10 16 ions/cm 2. Nanoindentation was used to characterize the films. Changes in hardness and reduced elastic modulus were examined as a function of ion fluence and irradiating species. The resulting increases in hardness and reduced elastic modulus are compared to similarly processed acid catalyzed silicate thin films.

Shock compression of stishovite and melting of silica at planetary interior conditions

NASA Astrophysics Data System (ADS)

Millot, M.; Dubrovinskaia, N.; Černok, A.; Blaha, S.; Dubrovinsky, L.; Braun, D. G.; Celliers, P. M.; Collins, G. W.; Eggert, J. H.; Jeanloz, R.

2015-01-01

Deep inside planets, extreme density, pressure, and temperature strongly modify the properties of the constituent materials. In particular, how much heat solids can sustain before melting under pressure is key to determining a planet’s internal structure and evolution. We report laser-driven shock experiments on fused silica, α-quartz, and stishovite yielding equation-of-state and electronic conductivity data at unprecedented conditions and showing that the melting temperature of SiO2 rises to 8300 K at a pressure of 500 gigapascals, comparable to the core-mantle boundary conditions for a 5-Earth mass super-Earth. We show that mantle silicates and core metal have comparable melting temperatures above 500 to 700 gigapascals, which could favor long-lived magma oceans for large terrestrial planets with implications for planetary magnetic-field generation in silicate magma layers deep inside such planets.

An efficient method for supercontinuum generation in dispersion-tailored Lead-silicate fiber taper

NASA Astrophysics Data System (ADS)

Chen, Z.; Ma, S.; Dutta, N. K.

2010-08-01

In this paper we theoretically study the broadband mid-IR supercontinuum generation (SCG) in a lead-silicate microstructured fiber (the glass for simulation is SF57). The total dispersion of the fiber can be tailored by changing the core diameter of the fiber so that dispersion profiles with two zero dispersion wavelengths (ZDWs) can be obtained. Numerical simulations of the SCG process in a 4 cm long SF57 fiber/fiber taper seeded by femto-second pulses at telecommunications wavelength of 1.55 µm are presented. The results show that a fiber taper features a continuous shift of the longer zero dispersion wavelength. This extends the generated continuum to a longer wavelength region compared to fibers with fixed ZDWs. The phase-matching condition (PMC) is continuously modified in the fiber taper and the bandwidth of the generated dispersive waves (DWs) is significantly broadened.

Planetary science. Shock compression of stishovite and melting of silica at planetary interior conditions.

PubMed

Millot, M; Dubrovinskaia, N; Černok, A; Blaha, S; Dubrovinsky, L; Braun, D G; Celliers, P M; Collins, G W; Eggert, J H; Jeanloz, R

2015-01-23

Deep inside planets, extreme density, pressure, and temperature strongly modify the properties of the constituent materials. In particular, how much heat solids can sustain before melting under pressure is key to determining a planet's internal structure and evolution. We report laser-driven shock experiments on fused silica, α-quartz, and stishovite yielding equation-of-state and electronic conductivity data at unprecedented conditions and showing that the melting temperature of SiO2 rises to 8300 K at a pressure of 500 gigapascals, comparable to the core-mantle boundary conditions for a 5-Earth mass super-Earth. We show that mantle silicates and core metal have comparable melting temperatures above 500 to 700 gigapascals, which could favor long-lived magma oceans for large terrestrial planets with implications for planetary magnetic-field generation in silicate magma layers deep inside such planets. Copyright © 2015, American Association for the Advancement of Science.

43 CFR 426.23 - Recovery of operation and maintenance (O&M) costs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Recovery of operation and maintenance (O&M... operation and maintenance (O&M) costs. (a) General. All new, amended, and renewed contracts shall provide for payment of O&M costs as specified in this section. (b) Amount of O&M costs a district must pay if...

Weathering of pyrogenic organic matter induces fungal oxidative enzyme response in single culture inoculation experiments.

PubMed

Gibson, Christy; Berry, Timothy D; Wang, Ruzhen; Spencer, Julie A; Johnston, Cliff T; Jiang, Yong; Bird, Jeffrey A; Filley, Timothy R

2016-02-01

The addition of pyrogenic organic matter (PyOM), the aromatic carbon-rich product of the incomplete combustion of plant biomass or fossil fuels, to soil can influence the rate of microbial metabolism of native soil carbon. The interaction of soil heterotrophs with PyOM may be governed by the surficial chemical and physical properties of PyOM that evolve with environmental exposure. We present results of a 36-day laboratory incubation investigating the interaction of a common white-rot fungus, Trametes versicolor, with three forms of 13 C-enriched (2.08 atom% 13 C) PyOM derived from Pinus ponderosa (450 °C): one freshly produced, and two artificially weathered (254 nm, UV light-water treatment and water-leaching alone). Analysis (FTIR, XPS) of the UV-weathered PyOM showed increased aliphatic C-H content and oxidation of aromatic carbon relative to both the original and water-leached PyOM. The addition of both weathered forms of PyOM stimulated (positively primed) fungal respiration of the growth media, while the unaltered PyOM mildly inhibited (negatively primed) respiration. Artificial weathering resulted in higher oxidative (laccase and peroxidase) enzyme activity than unaltered PyOM, possibly the result of a diminished capacity to bind reactive substrates and extracellular enzymes after weathering. However, and contrary to expectations, simple water-leached weathering resulted in a relatively higher enzyme activity and respiration than that of UV-weathering. The 13 C content of respired CO 2 indicated negligible fungal oxidation of PyOM for all treatments, demonstrating the overall low microbial reactivity of this high temperature PyOM. The increased enzymatic and positive priming response of T. versicolor to weathered PyOM highlights the importance of weathering-induced chemistry in controlling PyOM-microbe-soil carbon interactions.

Influence of Coprecipitated Organic Matter on Fe2+(aq) -Catalyzed Transformation of Ferrihydrite: Implications for Carbon Dynamics

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

Chen, Chunmei; Kukkadapu, Ravi K.; Sparks, Donald L.

2015-08-10

The poorly crystalline Fe(III) hydroxide ferrihydrite is an important sink for organic matter (OM), nutrients and contaminants in soils and sediments. Aqueous Fe(II) is known to catalyze the transformation of ferrihydrite to more crystalline and thus less reactive phases. While coprecipitation of OM with ferrihydrite could be a common process in many environments due to changes in pH, redox potential or ionic strength, little is known about the impacts of coprecipitated OM on Fe(II)-catalyzed ferrihydrite transformation and its consequences for C dynamics. Accordingly, we explored the extent and pathways of Fe(II)-induced transformation of OM-ferrihydrite coprecipitates and subsequent C mobility. Mössbauermore » spectroscopic results indicated that the coprecipitated OM within ferrihydrite weakened the inter-particle magnetic interactions and decreased average particle size. The coprecipitated OM resulted in diminished Fe(II)-induced ferrihydrite transformation and thus preservation of ferrihydrite. The secondary mineral profiles upon Fe(II) reaction with ferrihydrite were a function of OM content and Fe(II) concentration. At low Fe(II) levels, OM completely inhibited goethite formation and stimulated lepidocrocite formation. At high Fe(II) levels, whereas goethite was formed in the presence of OM, OM reduced the amount of goethite and magnetite formation and increased the formation of lepidocrcocite. The solid-phase C content remained unchanged after reaction, while OM desorpability by H2PO4- was enhanced following reaction of OM-ferrihydrites with aqueous Fe(II). These findings provide insights into the reactivity of natural ferrihydrite containing OM in soils and sediments and the subsequent impact on mineral evolution and C dynamics.« less

Mountain ranges, climate and weathering. Do orogens strengthen or weaken the silicate weathering carbon sink?

NASA Astrophysics Data System (ADS)

Maffre, Pierre; Ladant, Jean-Baptiste; Moquet, Jean-Sébastien; Carretier, Sébastien; Labat, David; Goddéris, Yves

2018-07-01

The role of mountains in the geological evolution of the carbon cycle has been intensively debated for the last decades. Mountains are thought to increase the local physical erosion, which in turns promotes silicate weathering, organic carbon transport and burial, and release of sulfuric acid by dissolution of sulfides. In this contribution, we explore the impact of mountain ranges on silicate weathering. Mountains modify the global pattern of atmospheric circulation as well as the local erosion conditions. Using an IPCC-class climate model, we first estimate the climatic impact of mountains by comparing the present day climate with the climate when all the continents are assumed to be flat. We then use these climate output to calculate weathering changes when mountains are present or absent, using standard expression for physical erosion and a 1D vertical model for rock weathering. We found that large-scale climate changes and enhanced rock supply by erosion due to mountain uplift have opposite effect, with similar orders of magnitude. A thorough testing of the weathering model parameters by data-model comparison shows that best-fit parameterizations lead to a decrease of weathering rate in the absence of mountain by about 20%. However, we demonstrate that solutions predicting an increase in weathering in the absence of mountain cannot be excluded. A clear discrimination between the solutions predicting an increase or a decrease in global weathering is pending on the improvement of the existing global databases for silicate weathering. Nevertheless, imposing a constant and homogeneous erosion rate for models without relief, we found that weathering decrease becomes unequivocal for very low erosion rates (below 10 t/km2/yr). We conclude that further monitoring of continental silicate weathering should be performed with a spatial distribution allowing to discriminate between the various continental landscapes (mountains, plains …).

Insights into the photo-induced formation of reactive intermediates from effluent organic matter: The role of chemical constituents.

PubMed

Zhou, Huaxi; Lian, Lushi; Yan, Shuwen; Song, Weihua

2017-04-01

In the present study, the formation of triplet states of organic matters ( 3 OM ∗ ) from effluent organic matter (EfOM) under simulated solar irradiation was investigated. EfOM was separated into hydrophobic (HPO), transphilic (TPI), and hydrophilic (HPI) components. The quantum yield coefficients (ƒ TMP ) of 3 OM ∗ were measured for each component and compared to those of reference natural organic matter (NOM). NaBH 4 reduction was performed on the EfOM, and the effect of aromatic ketones moieties on triplet formation was also determined. Furthermore, the apparent quantum yield of 1 O 2 (Φ 1O2 ) and O 2 •- (Φ O2•- ) was measured. Our results suggested that the HPI fraction acted as a sink for 3 OM ∗ . A linear correlation was observed between ƒ TMP and Φ 1O2 for NOM/EfOM, except for NaBH 4 -reduced effluent and HPI components. Both ƒ TMP and Φ 1O2 were positively correlated with the contribution rates of NaBH 4 -reducible moieties (aromatic ketones) toward 3 OM ∗ . Aromatic ketones were primarily responsible for the production of 3 OM ∗ from EfOM, whereas quinone moieties played a key role in the production of 3 OM ∗ in NOM-enriched solutions. Understanding the role of chemical constituents on the photo activity of EfOM/NOM is essential for providing useful insights on their photochemical effects in aquatic systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Black carbon surface oxidation and organic composition of beech-wood soot aerosols

NASA Astrophysics Data System (ADS)

Corbin, J. C.; Lohmann, U.; Sierau, B.; Keller, A.; Burtscher, H.; Mensah, A. A.

2015-10-01

Soot particles are the most strongly light-absorbing particles commonly found in the atmosphere. They are major contributors to the radiative budget of the Earth and to the toxicity of atmospheric pollution. Atmospheric aging of soot may change its health- and climate-relevant properties by oxidizing the primary black carbon (BC) or organic particulate matter (OM) which, together with ash, comprise soot. This atmospheric aging, which entails the condensation of secondary particulate matter as well as the oxidation of the primary OM and BC emissions, is currently poorly understood. In this study, atmospheric aging of wood-stove soot aerosols was simulated in a continuous-flow reactor. The composition of fresh and aged soot particles was measured in real time by a dual-vaporizer aerosol-particle mass spectrometer (SP-AMS). The dual-vaporizer SP-AMS provided information on the OM and BC components of the soot as well as on refractory components internally mixed with BC. By switching the SP-AMS laser vaporizer off and using only the AMS thermal vaporizer (at 600 °C), information on the OM component only was obtained. In both modes, OM appeared to be generated largely by cellulose and/or hemicellulose pyrolysis and was only present in large amounts when new wood was added to the stove. In SP-AMS mode, BC signals otherwise dominated the mass spectrum. These signals consisted of ions related to refractory BC (rBC, C1-5+), oxygenated carbonaceous ions (CO1-2+), potassium (K+), and water (H2O+ and related fragments). The C4+ : C3+ ratio, but not the C1+ : C3+ ratio, was consistent with the BC-structure trends of Corbin et al. (2015c). The CO1-2+ signals likely originated from BC surface groups: upon aging, both CO+ and CO2+ increased relative to C1-3+ while CO2+ simultaneously increased relative to CO+. Factor analysis (positive matrix factorization) of SP-AMS and AMS data, using a modified error model to address peak-integration uncertainties, indicated that the surface composition of the BC was approximately constant across all stages of combustion for both fresh and aged samples. These results represent the first time-resolved measurements of in situ BC surface aging and suggest that the surface of beech-wood BC may be modelled as a single chemical species.

A novel omega-3 free fatty acid formulation has dramatically improved bioavailability during a low-fat diet compared with omega-3-acid ethyl esters: the ECLIPSE (Epanova(®) compared to Lovaza(®) in a pharmacokinetic single-dose evaluation) study.

PubMed

Davidson, Michael H; Johnson, Judith; Rooney, Michael W; Kyle, Michael L; Kling, Douglas F

2012-01-01

Omega-3 (OM-3) fatty acid products are indicated for the treatment of severe hypertriglyceridemia; however, the omega-3-acid ethyl ester (OM-3 EE) formulations require significant pancreatic lipase stimulation with high-fat meals for adequate intestinal absorption of the metabolites eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A novel omega-3 free fatty acid (OM-3 FFA) formulation (Epanova(®), Omthera Pharmaceuticals Inc., Princeton, NJ) was developed to maximize EPA and DHA bioavailability during a low-fat diet. To compare the relative bioavailability of EPA and DHA from single 4-gram doses of OM-3 FFA and a prescription OM-3 EE (Lovaza(®), GlaxoSmithKline, Research Triangle Park, NC). This was a randomized, open-label, single dose, 4-way crossover, bioavailability study of OM-3 FFA and OM-3 EE administered during periods of low-fat and high-fat consumption to 54 overweight adults. Bioavailability was determined by the ln-transformed area under the plasma concentration versus time curve (AUC(0-t)) during a 24-hour interval for EPA and DHA (baseline-adjusted). The baseline-adjusted AUC(0-t) for total EPA + DHA during the low-fat period was 4.0-fold greater with OM-3 FFA compared with OM-3 EE (2650.2 vs 662.0 nmol·h/mL, respectively; P < .0001). During the high-fat period, AUC(0-t) for OM-3 FFA was approximately 1.3-fold greater than OM-3 EE (P < .0001). During the low-fat period, 30 of 51 (58.8%) subjects dosed with OM-3 FFA maintained an AUC(0-t) that was ≥50% of the respective high-fat AUC(0-t) in contrast to only 3 of 50 (6.0%) subjects dosed with OM-3 EE. During a low-fat consumption period, the OM-3 FFA formulation provided dramatically improved bioavailability over the OM-3 EE formulation in overweight subjects. These findings offer a potential therapeutic advantage of the OM-3 FFA formulation for the treatment of severe hypertriglyceridemia as these patients are expected to adhere to a low-fat diet. Copyright © 2012 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Trends in Effective Diffusion Coefficients for Ion-exchange Strengthening of Soda Lime Silicate Glasses

NASA Astrophysics Data System (ADS)

Karlsson, Stefan; Wondraczek, Lothar; Ali, Sharafat; Jonson, Bo

2017-04-01

Monovalent cations enable efficient ion exchange processes due to their high mobility in silicate glasses. Numerous properties can be modified in this way, e.g., mechanical, optical, electrical or chemical performance. In particular, alkali cation exchange has received significant attention, primarily with respect to introducing compressive stress into the surface region of a glass, which increases mechanical durability. However, most of the present applications rely on specifically tailored matrix compositions in which the cation mobility is enhanced. This largely excludes the major area of soda lime silicates (SLS) such as are commodity in almost all large-scale applications of glasses. Basic understanding of the relations between structural parameters and the effective diffusion coefficients may help to improve ion-exchanged SLS glass products, on the one hand in terms of obtainable strength and on the other in terms of cost. In the present paper, we discuss the trends in the effective diffusion coefficients when exchanging Na+ for various monovalent cations (K+, Cu+, Ag+, Rb+ and Cs+) by drawing relations to physico-chemical properties. Correlations of effective diffusion coefficients were found for the bond dissociation energy and the electronic cation polarizability, indicating that localization and rupture of bonds are of importance for the ion exchange rate.

Magmatic evolution of a Cordilleran flare-up and its role in the creation of silicic crust.

PubMed

Ward, Kevin M; Delph, Jonathan R; Zandt, George; Beck, Susan L; Ducea, Mihai N

2017-08-22

The role of magmatic processes as a significant mechanism for the generation of voluminous silicic crust and the development of Cordilleran plateaus remains a lingering question in part because of the inherent difficulty in quantifying plutonic volumes. Despite this difficulty, a growing body of independently measured plutonic-to-volcanic ratios suggests the volume of plutonic material in the crust related to Cordilleran magmatic systems is much larger than is previously expected. To better examine the role of crustal magmatic processes and its relationship to erupted material in Cordilleran systems, we present a continuous high-resolution crustal seismic velocity model for an ~800 km section of the active South American Cordillera (Puna Plateau). Although the plutonic-to-volcanic ratios we estimate vary along the length of the Puna Plateau, all ratios are larger than those previously reported (~30:1 compared to 5:1) implying that a significant volume of intermediate to silicic plutonic material is generated in the crust of the central South American Cordillera. Furthermore, as Cordilleran-type margins have been common since the onset of modern plate tectonics, our findings suggest that similar processes may have played a significant role in generating and/or modifying large volumes of continental crust, as observed in the continents today.

A formally verified algorithm for interactive consistency under a hybrid fault model

NASA Technical Reports Server (NTRS)

Lincoln, Patrick; Rushby, John

1993-01-01

Consistent distribution of single-source data to replicated computing channels is a fundamental problem in fault-tolerant system design. The 'Oral Messages' (OM) algorithm solves this problem of Interactive Consistency (Byzantine Agreement) assuming that all faults are worst-cass. Thambidurai and Park introduced a 'hybrid' fault model that distinguished three fault modes: asymmetric (Byzantine), symmetric, and benign; they also exhibited, along with an informal 'proof of correctness', a modified version of OM. Unfortunately, their algorithm is flawed. The discipline of mechanically checked formal verification eventually enabled us to develop a correct algorithm for Interactive Consistency under the hybrid fault model. This algorithm withstands $a$ asymmetric, $s$ symmetric, and $b$ benign faults simultaneously, using $m+1$ rounds, provided $n is greater than 2a + 2s + b + m$, and $m\\geg a$. We present this algorithm, discuss its subtle points, and describe its formal specification and verification in PVS. We argue that formal verification systems such as PVS are now sufficiently effective that their application to fault-tolerance algorithms should be considered routine.

Synchrotron X-ray spectroscopic investigations of an Nb-bearing silicate melt in contact with an aqueous fluid

NASA Astrophysics Data System (ADS)

Mayanovic, R. A.; Anderson, A. J.; Bassett, W. A.; Chou, I.

2006-05-01

Understanding the structural properties of trace elements in hydrous silicate melts in contact with a hydrothermal fluid is fundamentally important for a better assessment of the role of such elements in silicate melts being subjected to hydrothermal processes. We describe the use of synchrotron x-ray microprobe techniques and the modified hydrothermal diamond-anvil cell for in-situ spectroscopic analysis of individual phases of a silicate-melt/fluid system. Synchrotron X-ray fluorescence (XRF) and Nb K-edge X-ray absorption fine structure (XAFS) measurements were made on sectors ID20 and ID13 at the Advanced Photon Source, at the Argonne National Laboratory, on a Nb-bearing granitic glass in H2O and separately in a 1 M Na2CO3 aqueous solution at temperatures ranging from 25 to 880 °C and at up to 700 MPa of pressure. Individual phases of the Nb-glass/fluid system (at low temperatures) or the hydrous-silicate-melt/fluid system (at elevated temperatures) were probed using an X-ray beam focused to a diameter of 5 μm at the location of the sample. XRF analysis shows that the Nb partitions selectively from the hydrous silicate melt into the aqueous fluid at high temperatures in the Nb-glass/Na2CO3/H2O system but not so in the Nb-glass/H2O system. Analysis of XAFS spectra measured from the hydrous silicate melt phase of the Nb-glass/H2O sample in the 450 to 700 °C range shows that the first shell contains six oxygen atoms at a distance of ~1.98 Å. Our results suggest that reorganization of the silicate structure surrounding Nb occurs in the melt when compared to that of the starting glass. The X-ray absorption near edge structure (XANES) spectra show a pre-edge peak feature located at ~18995 eV that exhibits sharpening and becomes more intensified in the 450 to 700 °C range. Fitting of the Nb K-edge XANES spectra measured from the melt is accomplished using FEFF8.28 and an atomic model NbSi4O6-4(Na, K). The model is based on the structure of fresnoite (Ba2TiSi2O8), in which an NbO6 octahedron unit is substituted for the TiO5 unit, four Na and four K atoms are placed alternately on nearby Ba atom sites, and four Si atoms are arranged in a single plane intersecting the NbO6 unit. The results from fitting indicate that the local structure of Nb in the silicate melt is altered from its local structure in the quenched glass before heating and in the glass after heating in the diamond anvil cell. The importance of in situ analysis of melts and hydrothermal fluids at various temperatures and pressures is discussed in the context of our study.

Panel 1: Epidemiology and Diagnosis.

PubMed

Homøe, Preben; Kværner, Kari; Casey, Janet R; Damoiseaux, Roger A M J; van Dongen, Thijs M A; Gunasekera, Hasantha; Jensen, Ramon G; Kvestad, Ellen; Morris, Peter S; Weinreich, Heather M

2017-04-01

Objective To create a literature review between 2011 and June 1, 2015, on advances in otitis media (OM) epidemiology and diagnosis (including relevant audiology studies). Data Sources Electronic search engines (PubMed, EMBASE, and Cochrane Library) with a predefined search strategy. Review Methods Articles with appropriate epidemiologic methodology for OM, including acute mastoiditis and eustachian tube dysfunction. Items included OM worldwide and in high-risk populations, OM-related hearing loss, news in OM diagnostics, prenatal risk factors and comorbidities, postnatal risk factors, genetics, microbiological epidemiology, guidelines, and quality of life. Conclusions Diagnostic evidence and genetic studies are increasing; guidelines are introduced worldwide; and there is evidence of benefit of pneumococcal conjugate vaccines. New risk factors and comordities are identified in the study period, and quality of life is affected in children and their families. Implications for Practice Chronic suppurative OM occurs worldwide and contributes to lifelong hearing loss. Uniform definitions are still lacking and should be provided. An association between HIV and chronic suppurative OM has been found. Tympanometry is recommended for diagnosis, with or without pneumatic otoscopy. Video otoscopy, algorithms, and validated questionnaires may assist clinicians. Childhood obesity is associated with OM. Heritability accounts for 20% to 50% of OM diagnoses. OM-prone children seem to produce weaker immunologic responses to pneumococcal conjugate vaccines. Clinicians tend to individualize treatment without adhering to guidelines.

Influence of activated carbon preloading by EfOM fractions from treated wastewater on adsorption of pharmaceutically active compounds.

PubMed

Hu, Jingyi; Shang, Ran; Heijman, Bas; Rietveld, Luuk

2016-05-01

In this study, the preloading effects of different fractions of wastewater effluent organic matter (EfOM) on the adsorption of trace-level pharmaceutically active compounds (PhACs) onto granular activated carbon (GAC) were investigated. A nanofiltration (NF) membrane was employed to separate the EfOM by size, and two GACs with distinct pore structures were chosen for comparison. The results showed that preloading with EfOM substantially decreased PhAC uptake of the GACs; however, comparable PhAC adsorption capacities were achieved on GACs preloaded by feed EfOM and the NF-permeating EfOM. This indicates that: (1) the NF-rejected, larger EfOM molecules with an expectation to block the PhAC adsorption pores exerted little impact on the adsorbability of PhACs; (2) the smaller EfOM molecules present in the NF permeate contributed mainly to the decrease in PhAC uptake, mostly due to site competition. Of the two examined GACs, the wide pore-size-distributed GAC was found to be more susceptible to EfOM preloading than the microporous GAC. Furthermore, among the fourteen investigated PhACs, the negatively charged hydrophilic PhACs were generally subjected to a greater EfOM preloading impact. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of bone sialoprotein on proliferation and osteodifferentiation of human bone marrow-derived mesenchymal stem cells in vitro.

PubMed

Xia, Bing; Wang, Jie; Guo, Lida; Jiang, Zujun

2011-07-01

We performed this study to investigate the effects of recombinant human bone sialoprotein (BSP) on the proliferation and osteodifferentiation of human BMSCs(hBMSCs). The hBMSC cultures were divided into 4 groups: control group, 10(-10) M BSP group (BSP group), osteogenic medium group (10 nM dexamethasone, 10 mM β-glycerophosphate, and 50 mg/L ascorbic acid, OM group) and BSP + OM group (OM plus10(-10) M BSP). Compared with the control group, cell growth of the other three groups slowed down, while fluorescence at the G(0)/G(1) phase increased. After 28 days, in the OM group and the BSP + OM group, the proportion of STRO-1-positive cells decreased by 22.7% and 38.4% and ALP activity increased by 50% and 71.43%, respectively. CD271 mRNA expression decreased while Cbfa1, osteocalcin and osterix mRNA levels increased in the OM and BSP + OM groups, and the mRNA level change was greater in the BSP + OM group. After 28 days, the number of nodules in the BSP + OM group was 112.5% more than that in the OM group, but nodules did not formed in the control or BSP group. We conclude that BSP is capable of inhibiting hBMSCs proliferation and enhancing their osteogenic differentiation and mineralization in the presence of OM. Copyright © 2011 The International Alliance for Biologicals. Published by Elsevier Ltd. All rights reserved.

Enrichment of the Antibiotic Resistance Gene tet(L) in an Alkaline Soil Fertilized With Plant Derived Organic Manure.

PubMed

Peng, Shuang; Dolfing, Jan; Feng, Youzhi; Wang, Yiming; Lin, Xiangui

2018-01-01

Fifteen antibiotic resistance genes (ARGs) and intI1 , a gene involved in horizontal gene transfer (HGT) of ARGs, were quantified in three different soil samples from a 22 year old field experiment that had received inorganic fertilizer (NPK), organic manure (OM; a mixture of wheat straw, soybean oil cake and cotton cake), and control fields that had received no fertilizer and manure (CK). Tet (L) was the most abundant ARG in OM, which also contained considerable levels of intI1 . Molecular analysis of yearly collected archived soils over the past 22 years showed that tet (L) and intI1 were higher in OM soils than in NPK soils. The relative abundance of tet (L) was essentially constant during these years, while the level of intI1 in OM soils decreased over time. The main genotype of tet (L) was the same in archived and in fresh soil, OM, and irrigation water. Phylogenetic analysis of the 16S rRNA genes of tetracycline-resistant bacteria (TRB) isolates indicated that the Firmucutes carrying tet (L) in OM were similar to those in the OM soil, suggesting that OM transferred TRB into the OM soils where they survived. Almost all of the TRB isolated from OM carried tet (L) and belonged to the Firmicutes . Survival of bacteria from the organic manure that carried tet (L) may be the cause of the increased level of tet (L) in OM soil.

Dynamics of microbial community composition and soil organic carbon mineralization in soil following addition of pyrogenic and fresh organic matter.

PubMed

Whitman, Thea; Pepe-Ranney, Charles; Enders, Akio; Koechli, Chantal; Campbell, Ashley; Buckley, Daniel H; Lehmann, Johannes

2016-12-01

Pyrogenic organic matter (PyOM) additions to soils can have large impacts on soil organic carbon (SOC) cycling. As the soil microbial community drives SOC fluxes, understanding how PyOM additions affect soil microbes is essential to understanding how PyOM affects SOC. We studied SOC dynamics and surveyed soil bacterial communities after OM additions in a field experiment. We produced and mixed in either 350 °C corn stover PyOM or an equivalent initial amount of dried corn stover to a Typic Fragiudept soil. Stover increased SOC-derived and total CO 2 fluxes (up to 6x), and caused rapid and persistent changes in bacterial community composition over 82 days. In contrast, PyOM only temporarily increased total soil CO 2 fluxes (up to 2x) and caused fewer changes in bacterial community composition. Of the operational taxonomic units (OTUs) that increased in response to PyOM additions, 70% also responded to stover additions. These OTUs likely thrive on easily mineralizable carbon (C) that is found both in stover and, to a lesser extent, in PyOM. In contrast, we also identified unique PyOM responders, which may respond to substrates such as polyaromatic C. In particular, members of Gemmatimonadetes tended to increase in relative abundance in response to PyOM but not to fresh organic matter. We identify taxa to target for future investigations of the mechanistic underpinnings of ecological phenomena associated with PyOM additions to soil.

Low-temperature MIR to submillimeter mass absorption coefficient of interstellar dust analogues. II. Mg and Fe-rich amorphous silicates

NASA Astrophysics Data System (ADS)

Demyk, K.; Meny, C.; Leroux, H.; Depecker, C.; Brubach, J.-B.; Roy, P.; Nayral, C.; Ojo, W.-S.; Delpech, F.

2017-10-01

Context. To model the cold dust emission observed in the diffuse interstellar medium, in dense molecular clouds or in cold clumps that could eventually form new stars, it is mandatory to know the physical and spectroscopic properties of this dust and to understand its emission. Aims: This work is a continuation of previous studies aiming at providing astronomers with spectroscopic data of realistic cosmic dust analogues for the interpretation of observations. The aim of the present work is to extend the range of studied analogues to iron-rich silicate dust analogues. Methods: Ferromagnesium amorphous silicate dust analogues were produced by a sol-gel method with a mean composition close to Mg1-xFexSiO3 with x = 0.1, 0.2, 0.3, 0.4. Part of each sample was annealed at 500 °C for two hours in a reducing atmosphere to modify the oxidation state of iron. We have measured the mass absorption coefficient (MAC) of these eight ferromagnesium amorphous silicate dust analogues in the spectral domain 30-1000 μm for grain temperature in the range 10-300 K and at room temperature in the 5-40 μm range. Results: The MAC of ferromagnesium samples behaves in the same way as the MAC of pure Mg-rich amorphous silicate samples. In the 30-300 K range, the MAC increases with increasing grain temperature whereas in the range 10-30 K, we do not see any change of the MAC. The MAC cannot be described by a single power law in λ- β. The MAC of the samples does not show any clear trend with the iron content. However the annealing process has, on average, an effect on the MAC that we explain by the evolution of the structure of the samples induced by the processing. The MAC of all the samples is much higher than the MAC calculated by dust models. Conclusions: The complex behavior of the MAC of amorphous silicates with wavelength and temperature is observed whatever the exact silicate composition (Mg vs. Fe amount). It is a universal characteristic of amorphous materials, and therefore of amorphous cosmic silicates, that should be taken into account in astronomical modeling. The enhanced MAC of the measured samples compared to the MAC calculated for cosmic dust model implies that dust masses are overestimated by the models. The tabulated mass absorption coefficients are only 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/606/A50

Implementation of the Orbital Maneuvering Systems Engine and Thrust Vector Control for the European Service Module

NASA Technical Reports Server (NTRS)

Millard, Jon

2014-01-01

The European Space Agency (ESA) has entered into a partnership with the National Aeronautics and Space Administration (NASA) to develop and provide the Service Module (SM) for the Orion Multipurpose Crew Vehicle (MPCV) Program. The European Service Module (ESM) will provide main engine thrust by utilizing the Space Shuttle Program Orbital Maneuvering System Engine (OMS-E). Thrust Vector Control (TVC) of the OMS-E will be provided by the Orbital Maneuvering System (OMS) TVC, also used during the Space Shuttle Program. NASA will be providing the OMS-E and OMS TVC to ESA as Government Furnished Equipment (GFE) to integrate into the ESM. This presentation will describe the OMS-E and OMS TVC and discuss the implementation of the hardware for the ESM.

Associations between otitis media and child behavioural and learning difficulties: Results from a Danish cohort.

PubMed

Niclasen, J; Obel, C; Homøe, P; Kørvel-Hanquist, A; Dammeyer, J

2016-05-01

Findings from studies investigating early childhood episodes of otitis media (OM) and developmental outcomes are inconclusive. This may in part be because large-scale prospective studies controlling for relevant confounding factors are sparse. The present study investigates associations between OM in early childhood and later behavioural and learning difficulties controlling for relevant confounding factors. The study applied data from the Aarhus Birth Cohort's 10-12-year-old follow-up (N=7578). Associations between retrospective parent-reported OM (no OM; 1-3 episodes of OM with/without tympanostomy tubes; 4+ OM episodes without tympanostomy tubes and; 4+ OM episodes with tympanostomy tubes) one the one hand, and parent- and teacher-reported scores on the Strengths and Difficulties Questionnaire (SDQ) and parent-reported academic difficulties on the other hand, were investigated. The following variables were controlled for: parental educational level, maternal and paternal school problems, parental post-natal smoking, breastfeeding, and age at which the child started walking. All analyses were stratified by gender. Large differences in background characteristics were observed for the group of children with 4+ OM episodes with tympanostomy tubes compared to the no OM group. After controlling for relevant confounders, negative associations were consistently observed for the group of children with 4+ episodes of OM with tympanostomy tubes compared to the group of children without OM. This was particularly so for girls. The findings suggest an association between 4+ episodes of early OM with tympanostomy tubes and behavioural and learning difficulties later in childhood. The large inter-group differences, i.e. impact of residual and unmeasured confounding factors, may in part explain the observed associations and underline the need to include these in future studies. Copyright © 2016. Published by Elsevier Ireland Ltd.

Investigating molecular changes in organic matter composition in two Holocene lake-sediment records from central Sweden using pyrolysis-GC/MS

NASA Astrophysics Data System (ADS)

Ninnes, Sofia; Tolu, Julie; Meyer-Jacob, Carsten; Mighall, Tim M.; Bindler, Richard

2017-06-01

Organic matter (OM) is a key component of lake sediments, affecting carbon, nutrient, and trace metal cycling at local and global scales. Yet little is known about long-term (millennial) changes in OM composition due to the inherent chemical complexity arising from multiple OM sources and from secondary transformations. In this study we explore how the molecular composition of OM changes throughout the Holocene in two adjacent boreal lakes in central Sweden and compare molecular-level information with conventional OM variables, including total carbon, total nitrogen, C:N ratios, δ13C, and δ15N. To characterize the molecular OM composition, we employed a new method based on pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), which yields semiquantitative data on >100 organic compounds of different origin and degradation status. We identify large changes in OM composition after deglaciation (circa 8500 ± 500 B.C.), associated with early landscape development, and during the most recent 40-50 years, driven by degradation processes. With molecular-level information we can also distinguish between natural landscape development and human catchment disturbance during the last 1700 years. Our study demonstrates that characterization of the molecular OM composition by the high-throughput Py-GC/MS method is an efficient complement to conventional OM variables for identification and understanding of past OM dynamics in lake-sediment records. Holocene changes observed for pyrolytic compounds and compound classes known for having different reactivity indicate the need for further paleo-reconstruction of the molecular OM composition to better understand both past and future OM dynamics and associated environmental changes.

Patient and oncologist perceptions regarding symptoms and impact on quality-of-life of oral mucositis in cancer treatment: results from the Awareness Drives Oral Mucositis PercepTion (ADOPT) study.

PubMed

Kanagalingam, Jeevendra; Wahid, Mohamed Ibrahim A; Lin, Jin-Ching; Cupino, Nonette A; Liu, Edward; Kang, Jin-Hyoung; Bazarbashi, Shouki; Bender Moreira, Nicole; Arumugam, Harsha; Mueller, Stefan; Moon, Hanlim

2018-07-01

This descriptive cross-sectional survey aims to assess the level of concordance between the perspectives of oncologists and those of patients regarding oral mucositis (OM) symptoms, and the impact of OM on various aspects of daily living and concurrent cancer management. Oncologists involved in OM management (n = 105), and patients who developed OM during cancer treatment (n = 175), were recruited from seven Asian countries. Oncologists completed a face-to-face, quantitative interview; patients completed a face-to-face interview, and a self-reported questionnaire. Oncologists and patients ranked treatment-induced OM among the three most important toxicities of cancer therapy requiring intervention. The most frequent OM symptoms reported by patients were oral ulcers (74%), dry mouth (73%), and difficulty swallowing (62%). Oncologists expected mild OM symptoms to last slightly longer than 1 week, whereas patients reported mild symptoms for more than 2 weeks. In mild-to-moderate OM, oncologists underestimated patients' pain experience. Overall, only 45% of oncologists said they would initiate OM prophylaxis when cancer therapy started. Of the 87% of patients who said they used their prescribed medications, only 16% reported using prophylactically prescribed medication. While oncologists' concerns related to the delays and interruptions of cancer treatment, patients tended to focus on the effects of OM on eating, drinking, and talking. Oncologists' and patients' perceptions about treatment-induced OM differ. To overcome discordant perspectives, there is a need to raise general awareness and improve proactive management of OM. As noted in recent guidelines, supportive cancer care is critical for ensuring optimal therapy and for improving the patient's experience.

Biogeochemistry of mineral-organic associations across a long-term mineralogical soil gradient (0.3-4100 kyr), Hawaiian Islands

NASA Astrophysics Data System (ADS)

Mikutta, Robert; Schaumann, Gabriele E.; Gildemeister, Daniela; Bonneville, Steeve; Kramer, Marc G.; Chorover, Jon; Chadwick, Oliver A.; Guggenberger, Georg

2009-04-01

Organic matter (OM) in mineral-organic associations (MOAs) represents a large fraction of carbon in terrestrial ecosystems which is considered stable against biodegradation. To assess the role of MOAs in carbon cycling, there is a need to better understand (i) the time-dependent biogeochemical evolution of MOAs in soil, (ii) the effect of the mineral composition on the physico-chemical properties of attached OM, and (iii) the resulting consequences for the stabilization of OM. We studied the development of MOAs across a mineralogical soil gradient (0.3-4100 kyr) at the Hawaiian Islands that derived from basaltic tephra under comparable climatic and hydrological regimes. Mineral-organic associations were characterized using biomarker analyses of OM with chemolytic methods (lignin phenols, non-cellulosic carbohydrates) and wet chemical extractions, surface area/porosity measurements (N 2 at 77 K and CO 2 at 273 K), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC). The results show that in the initial weathering stage (0.3 kyr), MOAs are mainly composed of primary, low-surface area minerals (olivine, pyroxene, feldspar) with small amounts of attached OM and lignin phenols but a large contribution of microbial-derived carbohydrates. As high-surface area, poorly crystalline (PC) minerals increase in abundance during the second weathering stage (20-400 kyr), the content of mineral-associated OM increased sharply, up to 290 mg C/g MOA, with lignin phenols being favored over carbohydrates in the association with minerals. In the third and final weathering stage (1400-4100 kyr), metastable PC phases transformed into well crystalline secondary Fe and Al (hydr)oxides and kaolin minerals that were associated with less OM overall, and depleted in both lignin and carbohydrate as a fraction of total OM. XPS, the N 2 pore volume data and OM-mineral volumetric ratios suggest that, in contrast to the endmember sites where OM accumulated at the surfaces of larger mineral grains, topsoil MOAs of the 20-400-kyr sites are composed of a homogeneous admixture of small-sized PC minerals and OM, which originated from both adsorption and precipitation processes. The chemical composition of OM in surface-horizon MOAs, however, was largely controlled by the uniform source vegetation irrespective of the substrate age whereas in subsoil horizons, aromatic and carboxylic C correlated positively with oxalate-extractable Al and Si and CuCl 2-extractable Al concentrations representing PC aluminosilicates and Al-organic complexes ( r2 > 0.85). Additionally, XPS depth profiles suggest a zonal structure of sorbed OM with aromatic carbons being enriched in the proximity of mineral surfaces and amide carbons (peptides/proteins) being located in outer regions of MOAs. Albeit the mineralogical and compositional changes of OM, the rigidity of mineral-associated OM as analyzed by DSC changed little over time. A significantly reduced side chain mobility of sorbed OM was, however, observed in subsoil MOAs, which likely arose from stronger mineral-organic bindings. In conclusion, our study shows that the properties of soil MOAs change substantially over time with different mineral assemblages favoring the association of different types of OM, which is further accentuated by a vertical gradient of OM composition on mineral surfaces. Factors supporting the stabilization of sorbed OM were (i) the surface area and reactivity of minerals (primary or secondary crystalline minerals versus PC secondary minerals), (ii) the association of OM with micropores of PC minerals (via 'sterically' enhanced adsorption), (iii) the effective embedding of OM in 'well mixed' arrays with PC minerals and monomeric/polymeric metal species, (iv) the inherent stability of acidic aromatic OM components, and (iv) an impaired segmental mobility of sorbed OM, which might increase its stability against desorption and microbial utilization.

Landform Position and Combustion Temperature as Controls of Decomposition of Pyrogenic Organic Matter

NASA Astrophysics Data System (ADS)

Abney, R.; Berhe, A. A.

2016-12-01

Pyrogenic organic matter (PyOM) is the material left behind after incomplete combustion, which includes a spectrum of materials ranging from ash to charred biomass. Early research on PyOM assumed that it served as an inert carbon (C) pool within the soil. However, recent research has demonstrated that the decomposition of PyOM occurs on much shorter time scales. Even so, PyOM can serve as a C sink within the soil, and it can alter many soil properties. This study investigates the roles of both combustion temperature and landform position on decomposition of PyOM. Bark from Pinus jeffreyi was charred at three temperatures (200ºC, 350ºC, and 500ºC) to create PyOM, and this PyOM was incorporated into soil from two landform positions (eroding hillslope and deposition). Many recent studies on the decomposition of PyOM have utilized wood or agricultural byproducts as source material for PyOM, however bark experiences much of the effects of combustion, and it has received little to no research attention. Decomposition was measured via CO2 production from the soil and bark PyOM mixtures over an incubation period of six months. Microbial biomass was also measured throughout the incubation. The soil and PyOM mixtures were analyzed for elemental C and nitrogen, along with their stable isotopes, immediately after each gas measurement. We expect that the bark charred at higher temperatures will decompose slower than the bark charred at lower temperatures. We also expect that the bark incorporated into the depositional soil will decompose faster than the bark incorporated into the eroding soil. Several studies have already illustrated that landform position plays a critical role in controlling C storage and organic matter breakdown, however this has yet to be investigated with PyOM. Understanding the controls on PyOM breakdown is critical for better managing soils and the global C cycle.

Oral mask ventilation is more effective than face mask ventilation after nasal surgery.

PubMed

Yazicioğlu, Dilek; Baran, Ilkay; Uzumcugil, Filiz; Ozturk, Ibrahim; Utebey, Gulten; Sayın, M Murat

2016-06-01

To evaluate and compare the face mask (FM) and oral mask (OM) ventilation techniques during anesthesia emergence regarding tidal volume, leak volume, and difficult mask ventilation (DMV) incidence. Prospective, randomized, crossover study. Operating room, training and research hospital. American Society of Anesthesiologists physical status I and II adult patients scheduled for nasal surgery. Patients in group FM-OM received FM ventilation first, followed by OM ventilation, and patients in group OM-FM received OM ventilation first, followed by FM ventilation, with spontaneous ventilation after deep extubation. The FM ventilation was applied with the 1-handed EC-clamp technique. The OM was placed only over the mouth, and the 1-handed EC-clamp technique was used again. A child's size FM was used for the OM ventilation technique, the mask was rotated, and the inferior part of the mask was placed toward the nose. The leak volume (MVleak), mean airway pressure (Pmean), and expired tidal volume (TVe) were assessed with each mask technique for 3 consecutive breaths. A mask ventilation grade ≥3 was considered DMV. DMV occurred more frequently during FM ventilation (75% with FM vs 8% with OM). In the FM-first sequence, the mean TVe was 249±61mL with the FM and 455±35mL with the OM (P=.0001), whereas in the OM-first sequence, it was 276±81mL with the FM and 409±37mL with the OM (P=.0001). Regardless of the order used, the OM technique significantly decreased the MVleak and increased the TVe when compared to the FM technique. During anesthesia emergence after nasal surgery the OM may offer an effective ventilation method as it decreases the incidence of DMV and the gas leak around the mask and provides higher tidal volume delivery compared with FM ventilation. Copyright © 2016 Elsevier Inc. All rights reserved.

The Interacting controls of pyrolysis temperature and plant taxa on pyrogenic organic matter stability and decomposition in a Northern Michigan forest soil

NASA Astrophysics Data System (ADS)

Gibson, C. D.; Filley, T. R.; Bird, J. A.; Hatton, P. J.; Stark, R. E.; Nadelhoffer, K. J.

2017-12-01

Pyrogenic organic matter (PyOM) produced during forest fires is considered a large sink of stable soil organic matter (SOM) in boreal-temperate forest ecotones, where fire frequency and intensity is growing with changing climate. Understanding how changes in fire regime and predicted shifts in plant taxa will interact to affect PyOM dynamics in soil is imperative to assessing the impact of climate change on SOM maintenance. The stability of PyOM in soil may be co-determined by the physiochemical structure imparted on PyOM during pyrolysis and by its initial taxa-dependent wood chemistry and anatomy. To determine PyOM-C turnover rates in soil, we followed the fate of 13C-enriched wood or PyOM (200, 300, 450, or 600°C) derived from red maple (RM) or jack pine (JP) wood in soil from a recently burned forest in northern Michigan, USA. We found that pyrolysis temperature-controlled physiochemical changes influenced, with threshold dynamics, PyOM stability resulting in mean residence times of 2 (PyOM 200°C) to 450 years for both taxa, confirming that most PyOM (<600°C) turns over on the century, not millennial time scale. Water leachable C, carbohydrate and non-lignin phenol content correlated positively with early PyOM-C mineralization for both JP and RM, but the pyrolysis temperature at which this interaction was strongest differed with taxa reflecting the difference in thermal transition in which carbonization begins (300°C for JP and 450°C for RM). In contrast to previous studies, the addition of sucrose suggests that a co-metabolism mechanism of PyOM decomposition is minor in this soil. Our results show that while the first order control on PyOM stability in this soil is pyrolysis temperature, wood taxa did affect PyOM C MRT, in part due to differences in the amount of water soluble C released by PyOM during the initial decomposition dynamics in soil.

Terrestrial bitumen analogue of orgueil organic material demonstrates high sensitivity to usual HF-HCl treatment

NASA Technical Reports Server (NTRS)

Korochantsev, A. V.; Nikolaeva, O. V.

1993-01-01

The relationship between the chemical composition and the interlayer spacing (d002) of organic materials (OM's) is known for various terrestrial OM's. We improved this general trend by correlation with corresponding trend of natural solid bitumens (asphaltite-kerite-anthraxolite) up to graphite. Using the improved trend we identified bitumen analogs of carbonaceous chondrite OM's residued after HF-HCl treatment. Our laboratory experiment revealed that these analogs and, hence, structure and chemical composition of carbonaceous chondrite OM's are very sensitive to the HF-HCl treatment. So, usual extraction of OM from carbonaceous chondrites may change significantly structural and chemical composition of extracted OM.

Effects of agricultural practices on organic matter degradation in ditches

NASA Astrophysics Data System (ADS)

Hunting, Ellard R.; Vonk, J. Arie; Musters, C. J. M.; Kraak, Michiel H. S.; Vijver, Martina G.

2016-02-01

Agricultural practices can result in differences in organic matter (OM) and agricultural chemical inputs in adjacent ditches, but its indirect effects on OM composition and its inherent consequences for ecosystem functioning remain uncertain. This study determined the effect of agricultural practices (dairy farm grasslands and hyacinth bulb fields) on OM degradation by microorganisms and invertebrates with a consumption and food preference experiment in the field and in the laboratory using natural OM collected from the field. Freshly cut grass and hyacinths were also offered to control for OM composition and large- and small mesh-sizes were used to distinguish microbial decomposition and invertebrate consumption. Results show that OM decomposition by microorganisms and consumption by invertebrates was similar throughout the study area, but that OM collected from ditches adjacent grasslands and freshly cut grass and hyacinths were preferred over OM collected from ditches adjacent to a hyacinth bulb field. In the case of OM collected from ditches adjacent hyacinth bulb fields, both microbial decomposition and invertebrate consumption were strongly retarded, likely resulting from sorption and accumulation of pesticides. This outcome illustrates that differences in agricultural practices can, in addition to direct detrimental effects on aquatic organisms, indirectly alter the functioning of adjacent aquatic ecosystems.

Ferrihydrite-associated organic matter (OM) stimulates reduction by Shewanella oneidensis MR-1 and a complex microbial consortia

NASA Astrophysics Data System (ADS)

Cooper, Rebecca Elizabeth; Eusterhues, Karin; Wegner, Carl-Eric; Totsche, Kai Uwe; Küsel, Kirsten

2017-11-01

The formation of Fe(III) oxides in natural environments occurs in the presence of natural organic matter (OM), resulting in the formation of OM-mineral complexes that form through adsorption or coprecipitation processes. Thus, microbial Fe(III) reduction in natural environments most often occurs in the presence of OM-mineral complexes rather than pure Fe(III) minerals. This study investigated to what extent does the content of adsorbed or coprecipitated OM on ferrihydrite influence the rate of Fe(III) reduction by Shewanella oneidensis MR-1, a model Fe(III)-reducing microorganism, in comparison to a microbial consortium extracted from the acidic, Fe-rich Schlöppnerbrunnen fen. We found that increased OM content led to increased rates of microbial Fe(III) reduction by S. oneidensis MR-1 in contrast to earlier findings with the model organism Geobacter bremensis. Ferrihydrite-OM coprecipitates were reduced slightly faster than ferrihydrites with adsorbed OM. Surprisingly, the complex microbial consortia stimulated by a mixture of electrons donors (lactate, acetate, and glucose) mimics S. oneidensis under the same experimental Fe(III)-reducing conditions suggesting similar mechanisms of electron transfer whether or not the OM is adsorbed or coprecipitated to the mineral surfaces. We also followed potential shifts of the microbial community during the incubation via 16S rRNA gene sequence analyses to determine variations due to the presence of adsorbed or coprecipitated OM-ferrihydrite complexes in contrast to pure ferrihydrite. Community profile analyses showed no enrichment of typical model Fe(III)-reducing bacteria, such as Shewanella or Geobacter sp., but an enrichment of fermenters (e.g., Enterobacteria) during pure ferrihydrite incubations which are known to use Fe(III) as an electron sink. Instead, OM-mineral complexes favored the enrichment of microbes including Desulfobacteria and Pelosinus sp., both of which can utilize lactate and acetate as an electron donor under Fe(III)-reducing conditions. In summary, this study shows that increasing concentrations of OM in OM-mineral complexes determines microbial Fe(III) reduction rates and shapes the microbial community structure involved in the reductive dissolution of ferrihydrite. Similarities observed between the complex Fe(III)-reducing microbial consortia and the model Fe(III)-reducer S. oneidensis MR-1 suggest electron-shuttling mechanisms dominate in OM-rich environments, including soils, sediments, and fens, where natural OM interacts with Fe(III) oxides during mineral formation.

Dynamics of microbial community composition and soil organic carbon mineralization in soil following addition of pyrogenic and fresh organic matter

DOE PAGES

Whitman, Thea; Pepe-Ranney, Charles; Enders, Akio; ...

2016-04-29

Pyrogenic organic matter (PyOM) additions to soils can have large impacts on soil organic carbon (SOC) cycling. As the soil microbial community drives SOC fluxes, understanding how PyOM additions affect soil microbes is essential to understanding how PyOM affects SOC. We studied SOC dynamics and surveyed soil bacterial communities after OM additions in a field experiment. We produced and mixed in either 350 °C corn stover PyOM or an equivalent initial amount of dried corn stover to a Typic Fragiudept soil. Stover increased SOC-derived and total CO 2 fluxes (up to 6x), and caused rapid and persistent changes in bacterialmore » community composition over 82 days. In contrast, PyOM only temporarily increased total soil CO 2 fluxes (up to 2x) and caused fewer changes in bacterial community composition. Of the operational taxonomic units (OTUs) that increased in response to PyOM additions, 70% also responded to stover additions. These OTUs likely thrive on easily mineralizable carbon (C) that is found both in stover and, to a lesser extent, in PyOM. In contrast, we also identified unique PyOM responders, which may respond to substrates such as polyaromatic C. In particular, members of Gemmatimonadetes tended to increase in relative abundance in response to PyOM but not to fresh organic matter. As a result, we identify taxa to target for future investigations of the mechanistic underpinnings of ecological phenomena associated with PyOM additions to soil.« less

Dynamics of microbial community composition and soil organic carbon mineralization in soil following addition of pyrogenic and fresh organic matter

PubMed Central

Whitman, Thea; Pepe-Ranney, Charles; Enders, Akio; Koechli, Chantal; Campbell, Ashley; Buckley, Daniel H; Lehmann, Johannes

2016-01-01

Pyrogenic organic matter (PyOM) additions to soils can have large impacts on soil organic carbon (SOC) cycling. As the soil microbial community drives SOC fluxes, understanding how PyOM additions affect soil microbes is essential to understanding how PyOM affects SOC. We studied SOC dynamics and surveyed soil bacterial communities after OM additions in a field experiment. We produced and mixed in either 350 °C corn stover PyOM or an equivalent initial amount of dried corn stover to a Typic Fragiudept soil. Stover increased SOC-derived and total CO2 fluxes (up to 6x), and caused rapid and persistent changes in bacterial community composition over 82 days. In contrast, PyOM only temporarily increased total soil CO2 fluxes (up to 2x) and caused fewer changes in bacterial community composition. Of the operational taxonomic units (OTUs) that increased in response to PyOM additions, 70% also responded to stover additions. These OTUs likely thrive on easily mineralizable carbon (C) that is found both in stover and, to a lesser extent, in PyOM. In contrast, we also identified unique PyOM responders, which may respond to substrates such as polyaromatic C. In particular, members of Gemmatimonadetes tended to increase in relative abundance in response to PyOM but not to fresh organic matter. We identify taxa to target for future investigations of the mechanistic underpinnings of ecological phenomena associated with PyOM additions to soil. PMID:27128990

Freshwater processing of terrestrial dissolved organic matter: What governs lability?

NASA Astrophysics Data System (ADS)

D'Andrilli, J.; Smith, H. J.; Junker, J. R.; Scholl, E. A.; Foreman, C. M.

2016-12-01

Aquatic and terrestrial ecosystems are linked through the transfer of energy and materials. Allochthonous organic matter (OM) is central to freshwater ecosystem function, influencing local food webs, trophic state, and nutrient availability. In order to understand the nature and fate of OM from inland headwaters to the open ocean, it is imperative to understand the links between OM lability and ecosystem function. Thus, biological, chemical, and physical factors need to be evaluated together to inform our understanding of environmental lability. We performed a laboratory processing experiment on naturally occurring OM leachates from riparian leaves, grasses, and pine needles. Measures of water chemistry, OM optical and molecular characterization, bacterial abundances, microbial assemblage composition, respiration, and C:N:P were integrated to discern the nature and fate of labile and recalcitrant OM in a freshwater stream. Peak processing of all OM sources in the stream water occurred after two days, with spikes in bacterial cell abundances, respiration rates, microbial assemblage shifts, and maximum C utilization. Respiration rates and microbial assemblages were dependent on the degree of lability of the OM molecular composition. Within the first few days, no differences in respiration rates were observed between leachate sources, however, beyond day five, the rates diverged with C processing efficiency correlated with OM lability. Originally comprised of amino acid-like, labile fluorescent species, the inoculated stream water OM became more recalcitrant after 16 days, indicating humification processing over time. Our study highlights the importance of interdisciplinary approaches for understanding the processing and fate of OM in aquatic ecosystems.

Dynamics of microbial community composition and soil organic carbon mineralization in soil following addition of pyrogenic and fresh organic matter

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

Whitman, Thea; Pepe-Ranney, Charles; Enders, Akio

Pyrogenic organic matter (PyOM) additions to soils can have large impacts on soil organic carbon (SOC) cycling. As the soil microbial community drives SOC fluxes, understanding how PyOM additions affect soil microbes is essential to understanding how PyOM affects SOC. We studied SOC dynamics and surveyed soil bacterial communities after OM additions in a field experiment. We produced and mixed in either 350 °C corn stover PyOM or an equivalent initial amount of dried corn stover to a Typic Fragiudept soil. Stover increased SOC-derived and total CO 2 fluxes (up to 6x), and caused rapid and persistent changes in bacterialmore » community composition over 82 days. In contrast, PyOM only temporarily increased total soil CO 2 fluxes (up to 2x) and caused fewer changes in bacterial community composition. Of the operational taxonomic units (OTUs) that increased in response to PyOM additions, 70% also responded to stover additions. These OTUs likely thrive on easily mineralizable carbon (C) that is found both in stover and, to a lesser extent, in PyOM. In contrast, we also identified unique PyOM responders, which may respond to substrates such as polyaromatic C. In particular, members of Gemmatimonadetes tended to increase in relative abundance in response to PyOM but not to fresh organic matter. As a result, we identify taxa to target for future investigations of the mechanistic underpinnings of ecological phenomena associated with PyOM additions to soil.« less

Modified tricalcium silicate cement formulations with added zirconium oxide.

PubMed

Li, Xin; Yoshihara, Kumiko; De Munck, Jan; Cokic, Stevan; Pongprueksa, Pong; Putzeys, Eveline; Pedano, Mariano; Chen, Zhi; Van Landuyt, Kirsten; Van Meerbeek, Bart

2017-04-01

This study aims to investigate the effect of modifying tricalcium silicate (TCS) cements on three key properties by adding ZrO 2 . TCS powders were prepared by adding ZrO 2 at six different concentrations. The powders were mixed with 1 M CaCl 2 solution at a 3:1 weight ratio. Biodentine (contains 5 wt.% ZrO 2 ) served as control. To evaluate the potential effect on mechanical properties, the mini-fracture toughness (mini-FT) was measured. Regarding bioactivity, Ca release was assessed using ICP-AES. The component distribution within the cement matrix was evaluated by Feg-SEM/EPMA. Cytotoxicity was assessed using an XTT assay. Adding ZrO 2 to TCS did not alter the mini-FT (p = 0.52), which remained in range of that of Biodentine (p = 0.31). Ca release from TSC cements was slightly lower than that from Biodentine at 1 day (p > 0.05). After 1 week, Ca release from TCS 30 and TCS 50 increased to a level that was significantly higher than that from Biodentine (p < 0.05). After 1 month, Ca release all decreased (p < 0.05), yet TCS 0 and TCS 50 released comparable amounts of Ca as at 1 day (p > 0.05). EPMA revealed a more even distribution of ZrO 2 within the TCS cements. Particles with an un-reacted core were surrounded by a hydration zone. The 24-, 48-, and 72-h extracts of TCS 50 were the least cytotoxic. ZrO 2 can be added to TCS without affecting the mini-FT; Ca release was reduced initially, to reach a prolonged release thereafter; adding ZrO 2 made TCS cements more biocompatible. TCS 50 is a promising cement formulation to serve as a biocompatible hydraulic calcium silicate cement.

Spectroscopic characterization of organic matter of a soil and vinasse mixture during aerobic or anaerobic incubation

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

Doelsch, Emmanuel; Masion, Armand; Cazevieille, Patrick

2009-06-15

Mineralization potentials are often used to classify organic wastes. These methods involve measuring CO{sub 2} production during batch experiments, so variations in chemical compounds are not addressed. Moreover, the physicochemical conditions are not monitored during the reactions. The present study was designed to address these deficiencies. Incubations of a mixture of soil and waste (vinasse at 20% dry matter from a fermentation industry) were conducted in aerobic and anaerobic conditions, and liquid samples obtained by centrifugation were collected at 2 h, 1 d and 28 d. Dissolved organic carbon (DOC) patterns highlighted that: there was a 'soil effect' which increasedmore » organic matter (OM) degradation in all conditions compared to vinasse incubated alone; and OM degradation was faster under aerobic conditions since 500 mg kg{sup -1} of C remained after aerobic incubation, as compared to 4000 mg kg{sup -1} at the end of the anaerobic incubation period. No changes were detected by Fourier transform infrared spectroscopy (FTIR) between 2 h and 1 d incubation. At 28 days incubation, the FTIR signal of the aerobic samples was deeply modified, thus confirming the high OM degradation. Under anaerobic conditions, the main polysaccharide contributions ({nu}(C-O)) disappeared at 1000 and 1200 cm{sup -1}, as also confirmed by the {sup 13}C NMR findings. Under aerobic incubation, a 50% decrease in the polysaccharide proportion was observed. Under anaerobic conditions, significant chemical modifications of the organic fraction were detected, namely formation of low molecular weight organic acids.« less

Alteration layer formation of Ca- and Zn-oxide bearing alkali borosilicate glasses for immobilisation of UK high level waste: A vapour hydration study

NASA Astrophysics Data System (ADS)

Cassingham, N. J.; Corkhill, C. L.; Stennett, M. C.; Hand, R. J.; Hyatt, N. C.

2016-10-01

The UK high level nuclear waste glass modified with CaO/ZnO was investigated using the vapour phase hydration test, performed at 200 °C, with the aim of understanding the impact of the modification on the chemical composition and microstructure of the alteration layer. Experiments were undertaken on non-modified and CaO/ZnO-modified base glass, with or without 25 wt% of simulant Magnox waste calcine. The modification resulted in a dramatic reduction in gel layer thickness and also a reduction in the reaction rate, from 3.4 ± 0.3 g m-2 d-1 without CaO/ZnO modification to 0.9 ± 0.1 g m-2 d-1 with CaO/ZnO. The precipitated phase assemblage for the CaO/ZnO-modified compositions was identified as hydrated Ca- and Zn-bearing silicate phases, which were absent from the non-modified counterpart. These results are in agreement with other recent studies showing the beneficial effects of ZnO additions on glass durability.

Biological and land use controls on the isotopic composition of aquatic carbon in the Upper Mississippi River Basin

NASA Astrophysics Data System (ADS)

Voss, Britta M.; Wickland, Kimberly P.; Aiken, George R.; Striegl, Robert G.

2017-08-01

Riverine ecosystems receive organic matter (OM) from terrestrial sources, internally produce new OM, and biogeochemically cycle and modify organic and inorganic carbon. Major gaps remain in the understanding of the relationships between carbon sources and processing in river systems. Here we synthesize isotopic, elemental, and molecular properties of dissolved organic carbon (DOC), particulate organic carbon (POC), and dissolved inorganic carbon (DIC) in the Upper Mississippi River (UMR) system above Wabasha, MN, including the main stem Mississippi River and its four major tributaries (Minnesota, upper Mississippi, St. Croix, and Chippewa Rivers). Our goal was to elucidate how biological processing modifies the chemical and isotopic composition of aquatic carbon pools during transport downstream in a large river system with natural and man-made impoundments. Relationships between land cover and DOC carbon-isotope composition, absorbance, and hydrophobic acid content indicate that DOC retains terrestrial carbon source information, while the terrestrial POC signal is largely replaced by autochthonous organic matter, and DIC integrates the influence of in-stream photosynthesis and respiration of organic matter. The UMR is slightly heterotrophic throughout the year, but pools formed by low-head navigation dams and natural impoundments promote a shift toward autotrophic conditions, altering aquatic ecosystem dynamics and POC and DIC compositions. Such changes likely occur in all major river systems affected by low-head dams and need to be incorporated into our understanding of inland water carbon dynamics and processes controlling CO2 emissions from rivers, as new navigation and flood control systems are planned for future river and water resources management.

Biological and land use controls on the isotopic composition of aquatic carbon in the Upper Mississippi River Basin

USGS Publications Warehouse

Voss, Britta; Wickland, Kimberly P.; Aiken, George R.; Striegl, Robert G.

2017-01-01

Riverine ecosystems receive organic matter (OM) from terrestrial sources, internally produce new OM, and biogeochemically cycle and modify organic and inorganic carbon. Major gaps remain in the understanding of the relationships between carbon sources and processing in river systems. Here we synthesize isotopic, elemental, and molecular properties of dissolved organic carbon (DOC), particulate organic carbon (POC), and dissolved inorganic carbon (DIC) in the Upper Mississippi River (UMR) system above Wabasha, MN, including the main stem Mississippi River and its four major tributaries (Minnesota, upper Mississippi, St. Croix, and Chippewa Rivers). Our goal was to elucidate how biological processing modifies the chemical and isotopic composition of aquatic carbon pools during transport downstream in a large river system with natural and man-made impoundments. Relationships between land cover and DOC carbon-isotope composition, absorbance, and hydrophobic acid content indicate that DOC retains terrestrial carbon source information, while the terrestrial POC signal is largely replaced by autochthonous organic matter, and DIC integrates the influence of in-stream photosynthesis and respiration of organic matter. The UMR is slightly heterotrophic throughout the year, but pools formed by low-head navigation dams and natural impoundments promote a shift towards autotrophic conditions, altering aquatic ecosystem dynamics and POC and DIC composition. Such changes likely occur in all major river systems affected by low-head dams and need to be incorporated into our understanding of inland water carbon dynamics and processes controlling CO2 emissions from rivers, as new navigation and flood control systems are planned for future river and water resources management.

OM/OC Ratio and Specific Attenuation Coefficient in Ambient Particulate Matter at a Rural Site in Southern Ontario: Implications for Aerosol Aging and Emission Sources

NASA Astrophysics Data System (ADS)

Chan, T. W.; Huang, L.; Leaitch, R.; Sharma, S.; Brook, J.; Slowik, J.; Abbatt, J.

2008-05-01

Carbonaceous species (organic carbon (OC) and elemental carbon (EC)) contribute a large portion of atmospheric fine particle mass and influence air quality, human health, and climate forcing. However, their emission sources and atmospheric aging processes are not well understood. The OM/OC ratio, defined as the organic mass per unit OC mass, is useful to understand the degree of oxidation of aerosol particles in atmospheric processes. We define the modified BC/EC (mod BC/EC) ratio as the ratio of the non-scattering corrected absorption coefficient per unit mass of EC. The mod BC/EC ratio has a similar meaning as the site specific attenuation coefficient, which is an important parameter used to convert light absorption measurements to black carbon mass. The mod BC/EC ratio can vary due to light scattering effect on absorption measurements, in which the oxygenated organics may play a role. The pyrolysis organic carbon (POC) is defined as the carbon mass fraction obtained at T= 870°C under a pure helium environment using the thermal separation method [Huang et al., 2006]. Since POC mass is generally proportional to the amount of oxygenated OC, studying the relationships among OC, EC, POC, as well as OM/OC and mod BC/EC ratios may help us understand the mechanisms of aerosol aging from different emission sources. Two 1-month field studies were conducted at a rural site in southern Ontario (NW of Toronto) during fall 2005 and spring 2007. Quartz filter samples were collected and analyzed for OC, POC, and EC concentrations using a thermal/optical method [Huang et al., 2006]. Together with the total organic matter measured by an Aerodyne Aerosol Mass Spectrometer (AMS) and the absorption coefficient obtained from a Particle Soot Absorption Photometer (PSAP), the OM/OC and mod BC/EC ratios for ambient aerosols were obtained. Our results show that when air mass was mainly from south, OC, POC, and EC were relatively high, with average ratios of OC/EC, OM/OC, and POC/EC as 1.94, 1.41, and 0.52, respectively; this indicates significant anthropogenic impacts and relatively large portion of oxygenated OC, which might be due to either primary emissions or photo-chemical reactions occurred in a short period of time. When air mass was mainly from north, OC, POC, and EC were much lower, with average ratios of OC/EC, OM/OC, and POC/EC as 3.10, 1.20, and 0.79, respectively; this suggests less influence from anthropogenic emissions and relatively aged air mass from biogenic-source dominated clean air. Using POC, we estimate the specific attenuation at the site to be 5.8 m2 g-1 independent of the air mass origin. The relationships among OM/OC, mod BC/EC, and POC will be further discussed. References: Huang, L., Brook, J.R., Zhang, W., Li, S.M., Graham, L., Ernst, D., Chivulescu, A., and Lu, G. (2006) Stable isotope measurements of carbon fractions (OC/EC) in airborne particulate: a new dimension for source characterization and apportionment, Atmospheric Environment, 40, 2690-2705.

Characterization of uranium redox state in organic-rich Eocene sediments.

PubMed

Cumberland, Susan A; Etschmann, Barbara; Brugger, Joël; Douglas, Grant; Evans, Katy; Fisher, Louise; Kappen, Peter; Moreau, John W

2018-03-01

The presence of organic matter (OM) has a profound impact on uranium (U) redox cycling, either limiting or promoting the mobility of U via binding, reduction, or complexation. To understand the interactions between OM and U, we characterised U oxidation state and speciation in nine OM-rich sediment cores (18 samples), plus a lignite sample from the Mulga Rock polymetallic deposit in Western Australia. Uranium was unevenly dispersed within the analysed samples with 84% of the total U occurring in samples containing >21 wt % OM. Analyses of U speciation, including x-ray absorption spectroscopy and bicarbonate extractions, revealed that U existed predominately (∼71%) as U(VI), despite the low pH (4.5) and nominally reducing conditions within the sediments. Furthermore, low extractability by water, but high extractability by a bi-carbonate solution, indicated a strong association of U with particulate OM. The unexpectedly high proportion of U(VI) relative to U(IV) within the OM-rich sediments implies that OM itself does not readily reduce U, and the reduction of U is not a requirement for immobilizing uranium in OM-rich deposits. The fact that OM can play a significant role in limiting the mobility and reduction of U(VI) in sediments is important for both U-mining and remediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Discrimination in Degradability of Soil Pyrogenic Organic Matter Follows a Return-On-Energy-Investment Principle.

PubMed

Harvey, Omar R; Myers-Pigg, Allison N; Kuo, Li-Jung; Singh, Bhupinder Pal; Kuehn, Kevin A; Louchouarn, Patrick

2016-08-16

A fundamental understanding of biodegradability is central to elucidating the role(s) of pyrogenic organic matter (PyOM) in biogeochemical cycles. Since microbial community and ecosystem dynamics are driven by net energy flows, then a quantitative assessment of energy value versus energy requirement for oxidation of PyOM should yield important insights into their biodegradability. We used bomb calorimetry, stepwise isothermal thermogravimetric analysis (isoTGA), and 5-year in situ bidegradation data to develop energy-biodegradability relationships for a suite of plant- and manure-derived PyOM (n = 10). The net energy value (ΔE) for PyOM was between 4.0 and 175 kJ mol(-1); with manure-derived PyOM having the highest ΔE. Thermal-oxidation activation energy (Ea) requirements ranged from 51 to 125 kJ mol(-1), with wood-derived PyOM having the highest Ea requirements. We propose a return-on-investment (ROI) parameter (ΔE/Ea) for differentiating short-to-medium term biodegradability of PyOM and deciphering if biodegradation will most likely proceed via cometabolism (ROI < 1) or direct metabolism (ROI ≥ 1). The ROI-biodegradability relationship was sigmoidal with higher biodegradability associated with PyOM of higher ROI; indicating that microbes exhibit a higher preference for "high investment value" PyOM.

Protozoa enhance foraging efficiency of arbuscular mycorrhizal fungi for mineral nitrogen from organic matter in soil to the benefit of host plants.

PubMed

Koller, Robert; Rodriguez, Alia; Robin, Christophe; Scheu, Stefan; Bonkowski, Michael

2013-07-01

Dead organic matter (OM) is a major source of nitrogen (N) for plants. The majority of plants support N uptake by symbiosis with arbuscular mycorrhizal (AM) fungi. Mineralization of N is regulated by microfauna, in particular, protozoa grazing on bacteria. We hypothesized that AM fungi and protozoa interactively facilitate plant N nutrition from OM. In soil systems consisting of an OM patch and a root compartment, plant N uptake and consequences for plant carbon (C) allocation were investigated using stable isotopes. Protozoa mobilized N by consuming bacteria, and the mobilized N was translocated via AM fungi to the host plant. The presence of protozoa in both the OM and root compartment stimulated photosynthesis and the translocation of C from the host plant via AM fungi into the OM patch. This stimulated microbial activity in the OM patch, plant N uptake from OM and doubled plant growth. The results indicate that protozoa increase plant growth by both mobilization of N from OM and by protozoa-root interactions, resulting in increased C allocation to roots and into the rhizosphere, thereby increasing plant nutrient exploitation. Hence, mycorrhizal plants need to interact with protozoa to fully exploit N resources from OM. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Self-repairing properties of OPC clinker/natural zeolite blend in water and alkali carbonate environments at 270°C

DOE PAGES

Pyatina, Tatiana; Sugama, Toshifumi; Ronne, Arthur; ...

2018-01-01

The 10 d recoveries of the mechanical properties and crack sealing of an ordinary Portland cement (OPC) clinker/natural zeolite (ferrierite (Fer)) blend modified or unmodified with silica were tested at 270°C in water and alkali carbonate environments. The recoveries of the samples depended on their modification with silica and the curing environment, but were more than 100% after repeated damage under some test conditions. The mechanical properties and phase compositions of recovered samples were evaluated by compressive strength measurements and x-ray diffraction, differential thermogravimetric analyses, Fourier transform infrared analyses and scanning electron microscopy coupled with energy dispersive x-ray spectroscopy. Themore » sealing of 0·25 mm wide and ~2 mm deep cracks was visualised with a three-dimensional optical microscope. Fer decomposed under high-temperature alkaline conditions with the release of hydrolysates that, along with the hydrating clinker, participated in the formation of new phases contributing to strength recoveries. Here, these phases included crystalline magnesium and aluminium-containing silicates, calcium and carbonated calcium silicates and amorphous hydrates. Crack sealing was complete for the silica-modified samples and partial for unmodified ones cured in carbonate environments. The sealing was very poor for samples cured in water. Lastly, the main sealing phases included crystalline and amorphous silica, high-temperature-stable zeolites and talc mineral.« less

Self-repairing properties of OPC clinker/natural zeolite blend in water and alkali carbonate environments at 270°C

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

Pyatina, Tatiana; Sugama, Toshifumi; Ronne, Arthur

The 10 d recoveries of the mechanical properties and crack sealing of an ordinary Portland cement (OPC) clinker/natural zeolite (ferrierite (Fer)) blend modified or unmodified with silica were tested at 270°C in water and alkali carbonate environments. The recoveries of the samples depended on their modification with silica and the curing environment, but were more than 100% after repeated damage under some test conditions. The mechanical properties and phase compositions of recovered samples were evaluated by compressive strength measurements and x-ray diffraction, differential thermogravimetric analyses, Fourier transform infrared analyses and scanning electron microscopy coupled with energy dispersive x-ray spectroscopy. Themore » sealing of 0·25 mm wide and ~2 mm deep cracks was visualised with a three-dimensional optical microscope. Fer decomposed under high-temperature alkaline conditions with the release of hydrolysates that, along with the hydrating clinker, participated in the formation of new phases contributing to strength recoveries. Here, these phases included crystalline magnesium and aluminium-containing silicates, calcium and carbonated calcium silicates and amorphous hydrates. Crack sealing was complete for the silica-modified samples and partial for unmodified ones cured in carbonate environments. The sealing was very poor for samples cured in water. Lastly, the main sealing phases included crystalline and amorphous silica, high-temperature-stable zeolites and talc mineral.« less

Contrasting fates of organic matter in locations having different organic matter inputs and bottom water O2 concentrations

NASA Astrophysics Data System (ADS)

Mai-Thi, Ngoc-Nu; St-Onge, Guillaume; Tremblay, Luc

2017-11-01

The goals of this work were to study sedimentary organic matter (OM) composition and transformation since the end of the last deglaciation and to evaluate the influence of contrasting depositional conditions on these parameters. One station was located in the Lower St. Lawrence Estuary (LSLE) where the current bottom waters are hypoxic and receive terrigenous and marine OM. The other station, located in the Gulf of St. Lawrence (GSL), has more oxygenated bottom waters and almost only marine OM inputs. Analyses included enantiomers of amino acids (L and D-AA) and muramic acid that provide different markers of OM alteration state and reactivity and of bacterial contribution to OM composition and diagenesis. The markers clearly indicated the increase in OM alteration state with depth in the sediments of the LSLE and the GSL. The steady decrease in AA yields with depth confirmed the preferential degradation of AA compared to the rest of the OM. The OM in the surface sediment of the LSLE was less altered than that of the GSL and was enriched in bacterial biomass as indicated by much higher muramic acid yields. Results indicated that an important degradation of particulate organic matter occurs in the water column in the GSL, while it takes place mostly in the sediments in the LSLE. The presence of heterogeneous OM and hypoxic conditions in the LSLE likely reduce OM degradation rate in its deep water layer. However, the zone near the water-sediment interface is responsible for large variations in AA composition at both locations. A relatively new redox index, based on AA composition, was tested and appeared robust. This study highlights the importance of ambient conditions in determining the fate of OM and in the biogeochemical cycles of vital elements.

Evaluation of Mycobacterium tuberculosis viability in OMNIgene-SPUTUM reagent upon multi-day transport at ambient temperature.

PubMed

Tagliani, Elisa; Alagna, Riccardo; Tafaj, Silva; Hafizi, Hasan; Cirillo, Daniela Maria

2017-10-02

Maintaining the quality of clinical specimens for tuberculosis (TB) testing is a major challenge in many high TB burden-limited resources countries. Sample referral systems in low and middle income countries are often weak and the maintenance of the cold-chain challenging and very costly for TB programs. The development of transport media allowing the preservation of samples without refrigeration is critical for increasing access to TB diagnostic services and for reducing the costs related to testing. We evaluated the performance of OMNIgene-SPUTUM (OM-S) reagent for the maintenance of Mycobacterium tuberculosis (MTB) viability in sputum samples in the absence of refrigeration and its capacity to stabilize nucleic acid for molecular testing. A total of 329 sputum specimens from presumptive TB cases collected at the National Reference Laboratory in Tirana, Albania, were either decontaminated by a conventional method or processed with OM-S reagent and stored at room temperature. Samples in OM-S were shipped to the Supranational Reference Laboratory in Milan, Italy, at various times and processed for liquid culture. Our data show that OM-S maintains MTB viability for at least three weeks in the absence of refrigeration and improves the quality of culture resulting in a contamination rate lower than 0.5%. However, a significant delay in the time to culture positivity was observed for samples stored for more than two weeks in OM-S. Overall, OM-S offers multiple benefits both at laboratory and TB national program level by increasing the availability to quality diagnostics, promoting access to health care services and strengthening TB patient care especially in hard to reach populations.

Relationship between soluble microbial products (SMP) and effluent organic matter (EfOM): characterized by fluorescence excitation emission matrix coupled with parallel factor analysis.

PubMed

Yu, Huarong; Qu, Fangshu; Sun, Lianpeng; Liang, Heng; Han, Zhengshuang; Chang, Haiqing; Shao, Senlin; Li, Guibai

2015-02-01

Effluent organic matter (EfOM) originating from wastewater treatment plant (WWTP) is of significant concern, as it not only influences the discharge quality of WWTP but also exerts a significant effect on the efficiency of the downstream advanced treatment facilities. Soluble microbial products (SMP) is a major part of EfOM. In order to further understand the relationship between soluble microbial products (SMP) and EfOM, and in turn, to propose measures for EfOM control, the formation of SMP and EfOM in identical activated sludge sequencing batch reactors (SBR) with different feed water was investigated using fluorescence excitation and emission spectroscopy matrix coupled with parallel factor analysis (EEM-PARAFAC) as well as other organic matter quantification tools. Results showed that EfOM contained not only SMP but also a considerable amount of allochthonous organic matter that derived not merely from natural organic matter (NOM). Four components in EfOM/SMP were identified by EEM-PARAFAC. Tyrosine-like substances in EfOM (Component 3, λex/em=270/316 nm) were mainly originated from utilization associated products (UAP) of SMP. Tryptophan-like substances (Component 2, λex/em=280/336 nm) as well as fulvic-like and humic-like substances in EfOM (Component 1, λex/em=240(290)/392 nm and Component 4, λex/em=260(365)/444 nm) were majorly derived from the refractory substances introduced along with the influent, among which Component 2 was stemmed from sources other than NOM. As solid retention time (SRT) increased, Component 2 and polysaccharides in SMP/EfOM decreased, while Component 4 in SMP increased. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dose-Dependent Effects of the Myosin Activator Omecamtiv Mecarbil on Cross-Bridge Behavior and Force Generation in Failing Human Myocardium.

PubMed

Mamidi, Ranganath; Li, Jiayang; Gresham, Kenneth S; Verma, Sujeet; Doh, Chang Yoon; Li, Amy; Lal, Sean; Dos Remedios, Cristobal G; Stelzer, Julian E

2017-10-01

Omecamtiv mecarbil (OM) enhances systolic function in vivo by directly binding the myosin cross-bridges (XBs) in the sarcomere. However, the mechanistic details governing OM-induced modulation of XB behavior in failing human myocardium are unclear. The effects of OM on steady state and dynamic XB behavior were measured in chemically skinned myocardial preparations isolated from human donor and heart failure (HF) left ventricle. HF myocardium exhibited impaired contractile function as evidenced by reduced maximal force, magnitude of XB recruitment ( P df ), and a slowed rate of XB detachment ( k rel ) at submaximal Ca 2+ activations. Ca 2+ sensitivity of force generation (pCa 50 ) was higher in HF myocardium when compared with donor myocardium, both prior to and after OM incubations. OM incubation (0.5 and 1.0 μmol/L) enhanced force generation at submaximal Ca 2+ activations in a dose-dependent manner. Notably, OM induced a slowing in k rel with 1.0 μmol/L OM but not with 0.5 μmol/L OM in HF myocardium. Additionally, OM exerted other differential effects on XB behavior in HF myocardium as evidenced by a greater enhancement in P df and slowing in the time course of cooperative XB recruitment ( T rec ), which collectively prolonged achievement of peak force development ( T pk ), compared with donor myocardium. Our findings demonstrate that OM augments force generation but also prolongs the time course of XB transitions to force-bearing states in remodeled HF myocardium, which may extend the systolic ejection time in vivo. Optimal OM dosing is critical for eliciting enhanced systolic function without excessive prolongation of systolic ejection time, which may compromise diastolic filling. © 2017 American Heart Association, Inc.

Distinctive effects of allochthonous and autochthonous organic matter on CDOM spectra in a tropical lake

NASA Astrophysics Data System (ADS)

Pena Mello Brandão, Luciana; Silva Brighenti, Ludmila; Staehr, Peter Anton; Asmala, Eero; Massicotte, Philippe; Tonetta, Denise; Antônio Rodrigues Barbosa, Francisco; Pujoni, Diego; Fernandes Bezerra-Neto, José

2018-05-01

Despite the increasing understanding about differences in carbon cycling between temperate and tropical freshwater systems, our knowledge on the importance of organic matter (OM) pools on light absorption properties in tropical lakes is very scarce. We performed a factorial mesocosm experiment in a tropical lake (Minas Gerais, Brazil) to evaluate the effects of increased concentrations of allochthonous and autochthonous OM, and differences in light availability on the light absorption characteristics of chromophoric dissolved organic matter (CDOM). Autochthonous OM deriving from phytoplankton ( ˜ Chl a) was stimulated by addition of nutrients, while OM from degradation of terrestrial leaves increased allochthonous OM, and neutral shading was used to manipulate light availability. Effects of the additions and shading on DOC, Chl a, nutrients, total suspended solid concentrations (TSM) and spectral CDOM absorption were monitored every 3 days. CDOM quality was characterized by spectral indices (S250-450, S275-295, S350-450, SR and SUVA254). Effects of carbon sources and shading on the spectral CDOM absorption was investigated through principal component (PCA) and redundancy (RDA) analyses. The two different OM sources affected CDOM quality very differently and shading had minor effects on OM levels, but significant effects on OM quality, especially in combination with nutrient additions. Spectral indices (S250-450 and SR) were mostly affected by allochthonous OM addition. The PCA showed that enrichment by allochthonous carbon had a strong effect on the CDOM spectra in the range between 300 and 400 nm, while the increase in autochthonous carbon increased absorption at wavelengths below 350 nm. Our study shows that small inputs of allochthonous OM can have large effects on the spectral light absorption compared to large production of autochthonous OM, with important implications for carbon cycling in tropical lakes.

Trends in Otitis Media and Myringotomy With Tube Placement Among American Indian and Alaska Native Children and the US General Population of Children After Introduction of the 13-valent Pneumococcal Conjugate Vaccine.

PubMed

Singleton, Rosalyn; Seeman, Sara; Grinnell, Margaret; Bulkow, Lisa; Kokesh, John; Emmett, Susan; Holve, Stephen; McCollum, Jeffrey; Hennessy, Thomas

2018-01-01

American Indian/Alaska Native (AI/AN) children have experienced higher otitis media (OM) outpatient visit rates than other US children. To understand recent trends, we evaluated AI/AN OM rates before and after 13-valent pneumococcal conjugate vaccine introduction. We analyzed outpatient visits listing OM as a diagnosis among AI/AN children <5 years of age from the Indian Health Service National Patient Information Reporting System for 2010-2013. OM outpatient visits for the general US child population <5 years of age were analyzed using the National Ambulatory Medical Care and National Hospital Ambulatory Care Surveys for 2010-2011. The 2010-2011 OM-associated outpatient visit rate for AI/AN children (63.5 per 100/year) was similar to 2010-2011 rate for same-age children in the general US population (62.8) and decreased from the 2003 to 2005 AI/AN rate (91.4). Further decline in AI/AN OM visit rates was seen for 2010-2011 to 2012-2013 (P < 0.0001). The AI/AN infant OM visit rate (130.5) was 1.6-fold higher than the US infant population. For 2010-2011, the highest AI/AN OM visit rate for <5 year olds was from Alaska (135.0). AI/AN <5-year-old OM visits declined by one third from 2003-2005 to 2010-2011 to a rate similar to the US general population <5 years. However, the AI/AN infant OM rate remained higher than the US infant population. The highest AI/AN <5-year-old OM rate occurred in Alaska.

Psychometric qualities of questionnaires for the assessment of otitis media impact.

PubMed

Timmerman, A A; Meesters, C M G; Speyer, R; Anteunis, L J C

2007-12-01

The assessment of impact and evaluation of treatment effects in chronic otitis media (OM) calls for a much broader approach than just examining the presence of middle ear effusion or hearing loss. It is increasingly recognised that this condition may result in a comprised quality of life. Several studies have used proxy completed questionnaires to objectify the illness experience associated with chronic OM. To review questionnaires which have been developed to describe the effects of chronic OM on the daily functioning of children. Psychometric properties have been evaluated, in addition to discriminative and evaluative qualities. A systematic review of publications pertaining to developed questionnaires related with chronic OM. Systematic literature searches of PubMed (1966-January 2007) and EMBASE (1989-January 2007) were conducted, supplemented by using free text words to identify publications after January 2005. The included 15 questionnaires were developed for children with recurrent or persistent OM, describing functional health status (FHS), while two questionnaires also evaluate the effect of tympanostomy tubes insertion. The questionnaires generally cover six impact areas (physical symptoms, child development, educational performance, emotional/practical burden and general health status) with physical symptoms being the most prominant. The OM8-30, OMO-22 and OM-6 adequately reflect the multidimensional aspects of FHS in chronic OM. The OMO-22 and OM8-30 show the best psychometric properties for the discrimination of impact severity between children, while the OM-6 was found to have the best qualities for the evaluation of clinical change. Clinical applicability is crucial for the assessment of FHS in chronic OM, but requires a trade-off with necessary psychometric properties.

Development of olmesartan medoxomil optimized nanosuspension using the Box-Behnken design to improve oral bioavailability.

PubMed

Nagaraj, K; Narendar, D; Kishan, V

2017-07-01

The aim of the present investigation was to enhance the oral bioavailability of olmesartan medoxomil by improving its solubility and dissolution rate by preparing nanosuspension (OM-NS), using the Box-Behnken design. In this, four factors were evaluated at three levels. Independent variables include: concentration of drug (X 1 ), concentration of surfactant (X 2 ), concentration of polymer (X 3 ) and number of homogenization cycles (X 4 ). Based on preliminary studies, the size (Y 1 ), zeta potential (ZP) (Y 2 ) and % drug release at 5 min (Y 3 ) were chosen as dependent responses. OM-NS was prepared by high pressure homogenization method. The size, PDI, ZP, assay, in vitro release and morphology of OM-NS were characterized. Further, the pharmacokinetic (PK) behavior of OM-NS was evaluated in male wistar rats. Statistically optimized OM-NS formulation exhibited mean particle size of 492 nm, ZP of -27.9 mV and 99.29% release in 5 min. OM-NS showed more than four times increase in its solubility than pure OM. DSC and XRD analyses indicated that the drug incorporated into OM-NS was in amorphous form. The morphology of OM-NS was found to be nearly spherical with high dispersity by scanning electron microscopic studies. The PK results showed that OM lyophilized nanosuspension (NS) exhibited improved PK properties compared to coarse powder suspension and marketed tablet powder suspension (TS). Oral bioavailability of lyophilized NS was increased by 2.45 and 2.25 folds when compared to marketed TS and coarse powder suspension, respectively. Results of this study lead to conclusion that NS approach was effective in preparing OM formulations with enhanced dissolution and improved oral bioavailability.

Does Silicate Weathering of Loess Affect Atmospheric CO2?

NASA Astrophysics Data System (ADS)

Anderson, S. P.

2002-12-01

Weathering of glacial loess may be a significant, yet unrecognized, component of the carbon cycle. Glaciers produce fine-grained sediment, exposing vast amounts of mineral surface area to weathering processes, yet silicate mineral weathering rates at glacier beds and of glacial till are not high. Thus, despite the tremendous potential for glaciers to influence global weathering rates and atmospheric CO2 levels, this effect has not been demonstrated. Loess, comprised of silt-clay sizes, may be the key glacial deposit in which silicate weathering rates are high. Loess is transported by wind off braid plains of rivers, and deposited broadly (order 100 km from the source) in vegetated areas. Both the fine grain size, and hence large mineral surface area, and presence of vegetation should render loess deposits highly susceptible to silicate weathering. These deposits effectively extend the geochemical impact of glaciation in time and space, and bring rock flour into conditions conducive to chemical weathering. A simple 1-d model of silicate weathering fluxes from a soil profile demonstrates the potential of loess deposition to enhance CO2 consumption. At each time step, computed mineral dissolution (using anorthite and field-based rate constants) modifies the size of mineral grains within the soil. In the case of a stable soil surface, this results in a gradual decline in weathering fluxes and CO2 consumption through time, as finer grain sizes dissolve away. Computed weathering fluxes for a typical loess, with an initial mean grain size of 25 μm, are an order of magnitude greater than fluxes from a non-loess soil that differs only in having a mean grain size of 320 μm. High weathering fluxes are maintained through time if loess is continually deposited. Deposition rates as low as 0.01 mm/yr (one loess grain thickness per year) can lead to a doubling of CO2 consumption rates within 5 ka. These results suggest that even modest loess deposition rates can significantly increase CO2 consumption rates due to silicate weathering in soils. Thick loess deposits cover 5-10% of the global land surface, and loess deposits too thin to be included in global inventories cover a much greater area. Loess deposition and weathering over timescales greater than the duration of glaciation must be considered in models of atmospheric CO2 variation.

Expression of calcium-binding proteins S100A8, S100A9 and S100A12 in otitis media.

PubMed

Hong, Wenzhou; Khampang, Pawjai; Samuels, Tina L; Kerschner, Joseph E; Yan, Ke; Simpson, Pippa

2017-10-01

Calgranulins (calcium-binding proteins S100A8, S100A9 and S100A12) are predominant cytoplasmic proteins of neutrophils and produced by various cells, playing multiple functions in innate immunity and the inflammatory process. Although up-regulated expression of S100A8 and S100A9 genes were observed in an animal model of otitis media (OM), their expressions have not been studied in human middle ear epithelial cells in response to the OM pathogen or in patients with recurrent or chronic OM (recurrent OM/RecOM or chronic OM with effusion/COME). Gene expressions were compared between Streptococcus pneumoniae (SP)-infected and non-infected human middle ear epithelial cells (HMEECs) as well as between chronic OM patients and control patients (CI). Gene expressions were profiled by quantitative real time PCR (qPCR). S100 proteins in OM patient and CI middle ear biopsies were detected by immunostaining. S100A8, S100A9 and S100A12 gene expressions were elevated in SP-infected HMEECs in time-dependent manner. S100A8 and S100A9 but not S100A12 gene expression was significantly elevated in the middle ear mucosa of OM patients. S100A8 and S100A9 protein were observed in middle ear mucosa of OM, but not CI patients. Minimal co-localization was observed between S100A8 and S100A9 with neutrophil elastase and cytokeratin in ME sections of OM patients. Elevated S100A8 and S100A9 gene expression in SP-infected HMEECs and in the middle ear mucosa of OM, minor co-localized with neutrophil markers suggests that middle ear epithelial cell secretion of S100A8 and S100A9 may play a role in the pathogenesis of recurrent and chronic OM. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of Organic Matter Sources within a Matrix of Land Use in Northeast Utah

NASA Astrophysics Data System (ADS)

Kelso, J. E.; Baker, M. A.

2017-12-01

Dynamics of organic matter (OM) sources in natural aquatic systems have been studied for decades, but urban studies have revealed additional, less studied, OM sources such as stormwater, lawn clippings, and wastewater effluent. Traditionally the OM pool in freshwater systems has been defined as a homogenous pool of varying size classes: course particulate, fine particulate and dissolved OM. Our goal was to identify and quantify the composition of fine particulate OM (FPOM), and dissolved OM (DOM) as derived from autochthonous, terrestrial, and potential anthropogenic sources. We hypothesized anthropogenic changes in land use have increased the proportion of autochthonous sources of OM. We sampled OM at 33 sites in four watersheds in northeast Utah that encompass a range of land uses. Stable isotopes of carbon, nitrogen, and deuterium were collected for all size classes of OM, and DOM was analyzed with a spectrofluorometer. Stable isotopes were used to estimate the proportion of autochthonous and terrestrial sources of OM. Fluorescence indices and a PARAFAC model were created from DOM excitation emission matrices (EEMs). FPOM appeared to be a mixture of autochthonous and terrestrial sources but overlap in endmember isotope values made quantifying the proportion of each source difficult. Higher deuterium values (-120 to -80‰) were associated with sites receiving wastewater effluent, while sites with agriculture, forest, and urban land use had lower deuterium isotope values (-200 to -110). DOM Excitation Emission Matrices were resolved into a 5-component PARAFAC model. The percent of protein-like DOM components tended to be higher in urban versus non-urban sites (mean 35%, S.D. 12% versus mean 25%, S.D. 15%). We concluded deuterium isotopes may be used as a tracer or wastewater effluent and DOM is composed of more labile, protein-like DOM with increased wastewater input. A greater understanding of the sources of OM can inform management and policy decisions aimed at mitigating the effects of OM pollution. For example, evaluating tradeoffs between mitigating the effects of OM inputs from cattle grazing versus building or improving waste water treatment facilities can be further explored.

Investigating organic matter in Fanno Creek, Oregon, Part 3 of 3: identifying and quantifying sources of organic matter to an urban stream

USGS Publications Warehouse

Goldman, Jami H.; Rounds, Stewart A.; Keith, Mackenzie K.; Sobieszczyk, Steven

2014-01-01

The sources, transport, and characteristics of organic matter (OM) in Fanno Creek, an urban stream in northwest Oregon, were assessed and quantified using: (1) optical instruments to calculate transported loads of dissolved, particulate, and total organic carbon, (2) fluorescence spectroscopy and stable isotope ratios (δ13C, δ15N) to elucidate sources and chemical properties of OM throughout the basin, and (3) synoptic sampling to investigate seasonal and hydrologic variations in the characteristics and quantity of OM. Results from this study indicate that of the roughly 324 (±2.9%) metric tons (tonnes, t) of organic carbon exported from the basin during March 2012 to March 2013, most of the OM in Fanno Creek was dissolved (72%) and was present year-round at concentrations exceeding 3–4 milligrams of carbon per liter, whereas particulate carbon typically was mobilized and transported only by higher-flow conditions. The isotopic and fluorescence characteristics of Fanno Creek OM indicate that the carbon originates primarily from terrestrial inputs, most likely riparian vegetative biomass that enters the stream via litterfall and overland transport and then travels through the system episodically as a result of hydrologic processes. The amount of OM exported from the Fanno Creek drainage over the course of a year in this study is consistent with previous estimates of annual riparian litterfall in or near the creek. Although the creek channel is actively eroding, most bank material has too little OM for that to be a dominant source of OM to the stream. Fluorescence data revealed that the OM contains primarily humic and fulvic-like components that become less aromatic as the OM moves downstream. The most significant seasonal variation was associated with OM transported in the first storms of the autumn season (fall flush). That material was characteristically different, with a larger fraction of microbially derived OM that probably resulted from an accumulation of easy-to-mobilize and decomposing material in the streambed during previous months of summertime low-flow conditions. The first fall flush produced the highest concentrations of OM of the entire year, and the resulting load of mobilized and decomposing OM resulted in a significant oxygen demand immediately downstream in the Tualatin River.

Disentangling controls on mineral-stabilized soil organic matter using a slurry incubation

NASA Astrophysics Data System (ADS)

Lavallee, J. M.; Cotrufo, M. F.; Paul, E. A.; Conant, R. T.

2014-12-01

Mineral-stabilized organic matter (OM) is the largest and oldest pool of soil carbon and nitrogen. Mineral stabilization limits OM availability to soil microbes, preventing its decomposition and prolonging its turnover. Thus, understanding controls on the decomposition of mineral-stabilized OM is key to understanding soil carbon and nitrogen dynamics. The very slow turnover of mineral-stabilized OM makes it challenging to study in a typical incubation, and as a result, many potential controls (temperature, OM chemistry, and mineralogy) on its turnover remain unclear. We aimed to better understand controls on decomposition of mineral-stabilized OM by employing a slurry incubation technique, which speeds up microbial processing of OM by maximizing OM accessibility to microbes. In a slurry incubation, we expect that any OM that is not stabilized on mineral surfaces will be available for decomposition and will be converted to CO2. Using this technique, we studied the interactive effects of incubation temperature, plant material type (aboveground vs. belowground), and soil fraction (silt vs. clay) on CO2 efflux and OM stabilization. We separated silt-sized and clay-sized fractions from an agricultural soil, added aboveground or belowground plant material to each, and incubated them at 15°C, 25°C and 35°C. The added plant material was isotopically labeled (13C and 15N), which allowed us to trace it through the system and distinguish between the responses of the new (derived from the plant material) and old (derived from what was already present in the silt and clay) OM to warming. We measured CO2 efflux and 13CO2 efflux throughout the incubation. We performed one short-term harvest at day 6 and one final harvest at day 60. Initial results show higher cumulative CO2 efflux at warmer temperatures regardless of plant material type or soil fraction. A larger fraction of that CO2 came from OM that was initially present in the silt and clay, rather than from the plant material that we added, which suggests faster turnover of that "old" OM at warmer temperatures. We will present CO2 efflux data in addition to total [C] and [N] and the isotopic ratios of 13C and 15N in the silt and clay at each harvest to explain how the interactions between warming, plant material type and soil fraction affect turnover of mineral stabilized OM.

Dye-doped silica-based nanoparticles for bioapplications

NASA Astrophysics Data System (ADS)

Nhung Tran, Hong; Nghiem, Thi Ha Lien; Thuy Duong Vu, Thi; Tan Pham, Minh; Van Nguyen, Thi; Trang Tran, Thu; Chu, Viet Ha; Thuan Tong, Kim; Thuy Tran, Thanh; Le, Thi Thanh Xuan; Brochon, Jean-Claude; Quy Nguyen, Thi; Nhung Hoang, My; Nguyen Duong, Cao; Thuy Nguyen, Thi; Hoang, Anh Tuan; Hoa Nguyen, Phuong

2013-12-01

This paper presents our recent research results on synthesis and bioapplications of dye-doped silica-based nanoparticles. The dye-doped water soluble organically modified silicate (ORMOSIL) nanoparticles (NPs) with the size of 15-100 nm were synthesized by modified Stöber method from methyltriethoxysilane CH3Si(OCH3)3 precursor (MTEOS). Because thousands of fluorescent dye molecules are encapsulated in the silica-based matrix, the dye-doped nanoparticles are extremely bright and photostable. Their surfaces were modified with bovine serum albumin (BSA) and biocompatible chemical reagents. The highly intensive luminescent nanoparticles were combined with specific bacterial and breast cancer antigen antibodies. The antibody-conjugated nanoparticles can identify a variety of bacterium, such as Escherichia coli O157:H7, through antibody-antigen interaction and recognition. A highly sensitive breast cancer cell detection has been achieved with the anti-HER2 monoclonal antibody-nanoparticles complex. These results demonstrate the potential to apply these fluorescent nanoparticles in various biodetection systems.

The role of modifier cation field strength, oxygen speciation and network cation interaction in pressure-induced structural changes of silicate melts and glasses: 27Al, and 11B MAS NMR studies

NASA Astrophysics Data System (ADS)

Bista, S.; Stebbins, J. F.

2017-12-01

In aluminosilicate melts and glasses, both non-bridging oxygen content (NBO) and modifier cation field strength (Mg>Ca>Na>K) are known to facilitate network cation (e.g. Al, B) coordination increase with pressure. However, the role of these two compositional parameters in pressure-induced structural changes is derived from data for a limited set of compositions, where effects of the interaction between these parameters is less understood. For example, the effects of NBO are largely based on studies of Na and K aluminosilicate glasses, but effects of geologically important, higher field strength modifier cations such as Mg2+ and Fe2+ could well be significantly different. In this study, we look at a wide compositional range of Na, Ca and Mg aluminosilicate glasses (quenched from high pressure melts near to the glass transition temperature) to understand the roles of NBO and modifier cation field strength that can extend our view of processes important for silicate melts common in nature. Our results show that the role of NBO in pressure-induced structural changes varies systematically with increasing field strength of the modifier cation. In Na aluminosilicate glasses recovered from 1.5 to 3 GPa, large increases in average aluminum coordination are observed in glasses with high NBO content, while no detectable increases are seen for low nominal NBO (jadeite). In contrast, Mg aluminosilicate glasses with both high and low NBO show similar, large increases in average aluminum coordination with increasing pressure. The behaviors of Ca aluminosilicates fall between those of Na and Mg-rich glasses. We have also looked at interactions between different network forming cations in pressure-induced structural changes in low NBO Ca-aluminoborosilicate glasses with varying B/Si. Both aluminum and boron increase dramatically in coordination in these compositions 1.5 to 3 GPa. Increases in both average aluminum coordination and densification are larger in compositions containing higher boron concentrations, suggesting an interaction between boron and aluminum network cations in pressure-induced structural changes.

A Whole Community Approach to Otitis Media--Reducing Its Incidence and Effects. Report.

ERIC Educational Resources Information Center

McSwan, David

Otitis media (OM) is an inflammation of the middle ear that is prevalent in childhood. OM can result in hearing loss, which interferes with learning. In Australia, indigenous children experience OM more often than other populations. Because teachers lack knowledge of OM and its effects on learning, affected children are often mislabeled as problem…

Shuttle performance enhancements using an OMS payload bay kit

NASA Technical Reports Server (NTRS)

Templin, Kevin C.; Mallini, Charles J.

1991-01-01

The study focuses on the use of an orbital maneuvering system (OMS) payload bay kit (PBK) designed to utilize OMS tanks identical to those currently employed in the Orbiter OMS pods. Emphasis is placed on payload deployment capability and payload servicing/reboost capability augmentation from the point of view of payload mass, maximum deployment altitudes, and initial retrieval and final deployment altitudes. The deployment, servicing, and reboost requirements of the Hubble Space Telescope and Advanced X-ray and Astrophysics Facility are analyzed in order to show the benefits an OMS PBK can provide for these missions. It is shown that OMS PBKs can provide the required capability enhancement necessary to support deployment, reboost, and servicing of payloads requiring altitudes greater than 325 nautical miles.

Chemical characterization and mass closure of PM10 and PM2.5 at an urban site in Karachi - Pakistan

NASA Astrophysics Data System (ADS)

Shahid, Imran; Kistler, Magdalena; Mukhtar, Azam; Ghauri, Badar M.; Ramirez-Santa Cruz, Carlos; Bauer, Heidi; Puxbaum, Hans

2016-03-01

A mass balance method is applied to assess main source contributions to PM2.5 and PM10 levels in Karachi. Carbonaceous species (elemental carbon, organic carbon, carbonate carbon), soluble ions (Ca++, Mg++, Na+, K+, NH4+, Cl-, NO3-, SO4-), saccharides (levoglucosan, galactosan, mannosan, sucrose, fructose, glucose, arabitol and mannitol) were determined in atmospheric fine (PM2.5) and coarse (PM10) aerosol samples collected under pre-monsoon conditions (March-April 2009) at an urban site in Karachi (Pakistan). The concentrations of PM2.5 and PM10 were found to be 75 μg/m3 and 437 μg/m3 respectively. The large difference between PM10 and PM2.5 originated predominantly from mineral dust. "Calcareous dust" and "siliceous dust" were the over all dominating material in PM, with 46% contribution to PM2.5 and 78% to PM10-2.5. Combustion particles and secondary organics (EC + OM) comprised 23% of PM2.5 and 6% of PM10-2.5. EC, as well as OC ambient levels were higher (59% and 56%) in PM10-2.5 than in PM2.5. Biomass burning contributed about 3% to PM2.5, and had a share of about 13% of ;EC + OM; in PM2.5. The impact of bioaerosol (fungal spores) was minor and had a share of 1 and 2% of the OC in the PM2.5 and PM10-2.5 size fractions. In case of secondary inorganic aerosols, ammonium sulphate (NH4)2SO4 contributes 4.4% to PM2.5 and no detectable quantity were found in fraction PM10-2.5. The sea salt contribution is about 2% both to PM2.5 and PM10-2.5.

ATMOSPHERIC AEROSOL SOURCE-RECEPTOR RELATIONSHIPS: THE ROLE OF COAL-FIRED POWER PLANTS

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

Allen L. Robinson; Spyros N. Pandis; Cliff I. Davidson

2004-04-01

This report describes the technical progress made on the Pittsburgh Air Quality Study (PAQS) during the period of September 2003 through February 2004. Significant progress was made this project period on the analysis of ambient data, source apportionment, and deterministic modeling activities. Results highlighted in this report include chemical fractionation of the organic fraction to quantify the ratio of organic mass to organic carbon (OM/OC). The average OM/OC ratio for the 31 samples analyzed so far is 1.89, ranging between 1.62 and 2.53, which is consistent with expectations for an atmospherically processed regional aerosol. Analysis of the single particle datamore » reveals that a on a particles in Pittsburgh consist of complex mixture of primary and secondary components. Approximately 79% of all particles measured with the instrument containing some form of carbon, with Carbonaceous Ammonium Nitrate (54.43%) being the dominant particle class. PMCAMx predictions were compared with data from more than 50 sites of the STN network located throughout the Eastern United States for the July 2001 period. OC and sulfate concentrations predicted by PMCAMx are within {+-}30% of the observed concentration at most of these sites. Spherical Aluminum Silicate particle concentrations (SAS) were used to estimate the contribution of primary coal emissions to fine particle levels at the central monitoring site. Primary emissions from coal combustion contribute on average 0.44 {+-} 0.3 {micro}g/m{sup 3} to PM{sub 2.5} at the site or 1.4 {+-} 1.3% of the total PM{sub 2.5} mass. Chemical mass balance analysis was performed to apportion the primary organic aerosol. About 70% of the primary OC emissions are from vehicular sources, with the gasoline contribution being on average three times greater than the diesel emissions in the summer.« less

Experimental immunization with anti-rheumatic bacterial extract OM-89 induces T cell responses to heat shock protein (hsp)60 and hsp70; modulation of peripheral immunological tolerance as its possible mode of action in the treatment of rheumatoid arthritis (RA)

PubMed Central

BLOEMENDAL, A; VAN DER ZEE, R; RUTTEN, V P M G; VAN KOOTEN, P J S; FARINE, J C; VAN EDEN, W

1997-01-01

OM-89 is a bacterial (Escherichia coli) extract used for oral administration in the treatment of RA. Given the evidence that immunity to bacterial heat shock antigens plays a critical role in the immunomodulation of arthritis and possibly inflammation in general, the purpose of the present studies was to evaluate the presence and immunogenicity of hsp in OM-89. Furthermore, we studied the effects of OM-89 in an experimental arthritis, where hsp are known to have a critical significance in disease development. In rats immunization with OM-89 was found to lead to proliferative T cell responses to hsp60 and hsp70 of both E. coli and mycobacterial origin. Conversely, immunization with hsp antigens was also found to induce T cell reactivity specific for OM-89. Based on this and the antigen specificity analysis of specific T cell lines, hsp70 (DnaK) turned out to be one of the major immunogenic constituents of OM-89. Parenteral immunization with OM-89 was found to reduce resistance to adjuvant arthritis (AA), whereas oral administration was found to protect against AA. Given the arthritis-inhibitory effect of oral OM-89 in AA, it is possible that peripheral tolerance is induced at the level of regulatory T cells with specificity for hsp. This may also constitute a mode of action for OM-89 as an arthritis-suppressive oral drug. PMID:9353151

Panel 4: Recent Advances in Otitis Media in Molecular Biology, Biochemistry, Genetics, and Animal Models

PubMed Central

Li, Jian-Dong; Hermansson, Ann; Ryan, Allen F.; Bakaletz, Lauren O.; Brown, Steve D.; Cheeseman, Michael T.; Juhn, Steven K.; Jung, Timothy T. K.; Lim, David J.; Lim, Jae Hyang; Lin, Jizhen; Moon, Sung-Kyun; Post, J. Christopher

2014-01-01

Background Otitis media (OM) is the most common childhood bacterial infection and also the leading cause of conductive hearing loss in children. Currently, there is an urgent need for developing novel therapeutic agents for treating OM based on full understanding of molecular pathogenesis in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. Objective To provide a state-of-the-art review concerning recent advances in OM in the areas of molecular biology, biochemistry, genetics, and animal model studies and to discuss the future directions of OM studies in these areas. Data Sources and Review Methods A structured search of the current literature (since June 2007). The authors searched PubMed for published literature in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. Results Over the past 4 years, significant progress has been made in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. These studies brought new insights into our understanding of the molecular and biochemical mechanisms underlying the molecular pathogenesis of OM and helped identify novel therapeutic targets for OM. Conclusions and Implications for Practice Our understanding of the molecular pathogenesis of OM has been significantly advanced, particularly in the areas of inflammation, innate immunity, mucus overproduction, mucosal hyperplasia, middle ear and inner ear interaction, genetics, genome sequencing, and animal model studies. Although these studies are still in their experimental stages, they help identify new potential therapeutic targets. Future preclinical and clinical studies will help to translate these exciting experimental research findings into clinical applications. PMID:23536532

SURVEY OF DENTAL STUDENTS' ATTITUDE REGARDING ORIENTAL MEDICINE/COMPLEMENTARY AND ALTERNATIVE MEDICINE: COMPARISON BETWEEN TWO JAPANESE DENTAL SCHOOLS.

PubMed

Kameyama, Atsushi; Toda, Kazuo

2017-01-01

The present study aimed to examine the impact of "curricula for undergraduate education in oriental medicine (OM)/complementary and alternative medicine (CAM)" on student awareness of OM. A questionnaire survey was conducted involving the Nagasaki University School of Dentistry (NUSD), a university that implements education in OM as part of its undergraduate curriculum, and Tokyo Dental College (TDC), which does not teach OM. The third- and fifth-year students of both NUSD and TDC underwent the anonymous questionnaire survey, which included questions regarding their knowledge of OM and CAM, interests in these subjects, and their opinions on the necessity of teaching OM in the undergraduate dental education, and the results were collected for analysis. Whereas 33% of 5 th year NUSD students had knowledge of OM/CAM was 33%, only 10% of 5 th year TDC students reported knowledge on the subject. 69% of 5 th year NUSD students interested in OM/CAM, while 5 th year TDC students who interest them were only 45%. Although 77% of 5 th year NUSD students were in favor of OM education implemented in the Faculty of Dentistry, the percentages of TDC students of that were smaller (46% in 3 rd year and 48% in 5 th year). Whereas 26% of 5 th year TDC students did not recognize the necessity of oriental medicine education, only one 5 th year NUSD student (2%) did not so. Introduction of education in OM in the undergraduate dental education program helps students to increase their interests in dental clinical applications.

Changes in cytokine and nitric oxide secretion by rat alveolar macrophages after oral administration of bacterial extracts.

PubMed Central

Broug-Holub, E; Persoons, J H; Schornagel, K; Kraal, G

1995-01-01

Oral administration of the bacterial immunomodulator Broncho-Vaxom (OM-85), a lysate of eight bacteria strains commonly causing respiratory disease, has been shown to enhance the host defence of the respiratory tract. In this study we examined the effect of orally administered (in vivo) OM-85 on stimulus-induced cytokine and nitric oxide secretion by rat alveolar macrophages in vitro. The results show that alveolar macrophages isolated from OM-85-treated rats secreted significantly more nitric oxide, tumour necrosis factor-alpha (TNF-alpha) and IL-1 beta upon in vitro stimulation with lipopolysaccharide (LPS), whereas, in contrast, LPS-induced IL-6 secretion was significantly lower. The observed effects of in vivo OM-85 treatment on stimulus-induced cytokine secretion in vitro are not due to a direct effect of OM-85 on the cells, because in vitro incubation of alveolar macrophages with OM-85 did not result in altered activity, nor did direct intratracheal instillation of OM-85 in the lungs of rats result in altered alveolar macrophage activity in vitro. It is hypothesized that oral administration of OM-85 leads to priming of alveolar macrophages in such a way that immune responses are non-specifically enhanced upon stimulation. The therapeutic action of OM-85 may therefore result from an enhanced clearance of infectious bacteria from the respiratory tract due to increased alveolar macrophage activity. PMID:7648713

Selective Activation of Human Dendritic Cells by OM-85 through a NF-kB and MAPK Dependent Pathway

PubMed Central

Scutera, Sara; Somma, Paolo; Salvi, Valentina; Musso, Tiziana; Tabbia, Giuseppe; Bardessono, Marco; Pasquali, Christian; Mantovani, Alberto; Sozzani, Silvano; Bosisio, Daniela

2013-01-01

OM-85 (Broncho-Vaxom®, Broncho-Munal®, Ommunal®, Paxoral®, Vaxoral®), a product made of the water soluble fractions of 21 inactivated bacterial strain patterns responsible for respiratory tract infections, is used for the prevention of recurrent upper respiratory tract infections and acute exacerbations in chronic obstructive pulmonary disease patients. OM-85 is able to potentiate both innate and adaptive immune responses. However, the molecular mechanisms responsible for OM-85 activation are still largely unknown. Purpose of this study was to investigate the impact of OM-85 stimulation on human dendritic cell functions. We show that OM-85 selectively induced NF-kB and MAPK activation in human DC with no detectable action on the interferon regulatory factor (IRF) pathway. As a consequence, chemokines (i.e. CXCL8, CXCL6, CCL3, CCL20, CCL22) and B-cell activating cytokines (i.e. IL-6, BAFF and IL-10) were strongly upregulated. OM-85 also synergized with the action of classical pro-inflammatory stimuli used at suboptimal concentrations. Peripheral blood mononuclear cells from patients with COPD, a pathological condition often associated with altered PRR expression pattern, fully retained the capability to respond to OM-85. These results provide new insights on the molecular mechanisms of OM-85 activation of the immune response and strengthen the rational for its use in clinical settings. PMID:24386121

Discrimination in Degradability of Soil Pyrogenic Organic Matter Follows a Return-On-Energy-Investment Principle

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

Harvey, Omar R.; Myers-Pigg, Allison N.; Kuo, Li-Jung

A fundamental understanding of biodegradability is central to elucidating the role(s) of pyrogenic organic matter (PyOM) in biogeochemical cycles. Since microbial community and ecosystem dynamics are driven by net energy flows, then a quantitative assessment of energy value versus energy requirement for oxidation of PyOM should yield important insights into their biodegradability. We used bomb calorimetry, step-wise isothermal thermogravimetric analysis (isoTGA) and 5-year in-situ bidegradation data, to develop energy-biodegradability relationships for a suite of plant- and manure-derived PyOM (n = 10). The net energy value (ΔE) for PyOM was between 4.0 and 175 kJ mol-1; with manure-derived PyOM having themore » highest ΔE. Thermal-oxidation activation energy (Ea) requirements ranged from 51 to 125 kJ mol-1, with wood-derived PyOM having the highest Ea requirements. We propose a return-on-investment (ROI) parameter (ΔE/Ea) for differentiating short-to-medium term biodegradability of PyOM and deciphering if biodegradation will most likely proceed via co-metabolism (ROI < 1) or direct metabolism (ROI ≥ 1). The ROI-biodegradability relationship was sigmoidal with higher biodegradability associated with PyOM of higher ROI; indicating that microbes exhibit a higher preference for “high investment value” PyOM.« less

The role of autochthonous organic matter in radioactive cesium accumulation to riverine fine sediments.

PubMed

Fujii, Manabu; Ono, Keisuke; Yoshimura, Chihiro; Miyamoto, Manami

2018-06-15

Anthropogenically released radioactive cesium (RCs) poses serious ecological and environmental concerns given its persistency in the environment. Although accumulation of RCs in aqueous and sedimentary environments is often reported to associate with organic matter (OM), the mechanisms responsible remain unclear. Here, we investigated RCs in fine sediments along the Abukuma River, the largest river near the Fukushima Daiichi Nuclear Power Plant, 1.5-4 years after the accident. Measuring the density-separated sediment fractions with a broad range of OM content (%) indicated that the RCs concentration (Bq·kg -1 ) is positively correlated with OM content for intermediate-density fractions in which OM is primarily characterized by autochthonous origin. This relationship, however, did not hold for light-density fractions containing a high proportion of large-size allochthonous OM. Furthermore, H 2 O 2 -assisted OM digestion and amorphous material dissolution treatments resulted in only a minor reduction in sedimentary RCs. These results along with the fact that sediments with high autochthonous OM content showed high specific surface area indicated that RCs is tightly associated with finer-grained and chemically non-labile inorganic fractions concurrently resident with autochthonous OM. Overall, our findings highlight that autochthonous OM exerts a significant control on the accumulation, transport, and fate of RCs in aqueous and sedimentary environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

20 CFR 229.68 - Reduction of DIB O/M.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Reduction of DIB O/M. 229.68 Section 229.68..., State, or Local Law or Plan § 229.68 Reduction of DIB O/M. A reduction for entitlement to worker's compensation or a public disability benefit is applied after the DIB O/M is reduced for age and the family...

20 CFR 229.68 - Reduction of DIB O/M.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Reduction of DIB O/M. 229.68 Section 229.68..., State, or Local Law or Plan § 229.68 Reduction of DIB O/M. A reduction for entitlement to worker's compensation or a public disability benefit is applied after the DIB O/M is reduced for age and the family...

Novel multi-day sputum transport reagent works with routine tuberculosis tests and eliminates need for cold chain: Preliminary study of compatibility with the Xpert® MTB/RIF assay.

PubMed

Kelly-Cirino, Cassandra D; Curry, Patricia S; Marola, Jamie L; Helstrom, Niels K; Salfinger, Max

2016-11-01

OMNIgene®•SPUTUM (OM-S) is a sputum transport reagent designed to work with all tuberculosis diagnostics and eliminate the need for cold chain. The aim of this preliminary study was to assess the compatibility of OM-S-treated sputum with the Xpert® MTB/RIF assay. Fifty-five characterized sputa from the FIND TB Specimen Bank were used. Compatibility of OM-S was assessed for both Xpert sample preparation methods: H.1 protocol (sediment, n=25) and H.2 protocol (direct expectorate, n=30). All controls were prepared using the H.2 protocol. Results revealed 100% concordance of MTB/RIF results for all except the low-positive group in the H.1 study arm (n=10; 88% concordance). OM-S-treated sputa were successful in both protocols; if the Xpert buffer is not added during the H.2 procedure, sample viscosity may require repeat testing. Using OM-S could offer users flexibility in clinical testing algorithms. Larger compatibility studies are warranted, particularly with respect to MTB/RIF results for low-positive samples. Copyright © 2016 Elsevier Inc. All rights reserved.

Adverse event management of oral mucositis in patients with breast cancer.

PubMed

Seiler, Sabine; Kosse, Jens; Loibl, Sibylle; Jackisch, Christian

2014-04-01

Oral mucositis (OM) is a clinically important and frequent adverse event (AE) associated with cancer treatment with conventional chemotherapy as well as new targeted agents. Incidence and severity of OM vary from treatment to treatment and from patient to patient. The pathogenesis of chemotherapy-induced OM can be divided into 5 phases. OM induced by targeted therapies differs among other things in appearance, course, concomitant AEs and toxicity, and thus could be perceived as an entity distinct from chemotherapy-induced OM with an innate pathogenic mechanism. OM has a severe impact on a patient's quality of life (QoL) by causing complications such as pain and discomfort. Even more important are associated restrictions in nutrition and hydration. Thus, the efficacy of cancer therapy might be impaired due to the necessity of dose delays and dose reductions. Numerous preventive and therapeutic approaches have been evaluated, but currently no single agent has changed the standard of care in preventing and treating OM. Thus, the current management has evolved from clinical experience rather than clinical evidence. This article will review the AE 'OM' induced by breast cancer treatment with chemotherapy and targeted agents in order to provide practical guidance for management and prevention.

Capability and flight record of the versatile space shuttle OMS engine

NASA Astrophysics Data System (ADS)

Judd, D. Craig

The development contract for Aerojet's Orbital Manuevering Subsystem (OMS) engine was awarded in February 1974. This paper provides a description of the OMS subcomponents along with a summary of the OMS development program and subsequent flight record. The major subcomponents include the platelet injector, regeneratively cooled chamber, radiation cooled nozzle extension, bipropellant valve, thrust mount, gimbal actuator assembly, and propellant feedlines. The OMS engine underwent an extensive development program between 1974 and 1978 that included approximately 3680 tests performed on 21 separate engines on components for a total duration of more than 19,000 seconds. This was followed with qualification testing of two engines with another 521 tests and 18,504 seconds of hot fire testing. The Space Shuttle system has completed 45 orbital flights with the OMS engines having fired a total of 356 times with a cumulative duration of 38,094 seconds. In all cases, the OMS engine has performed as required because of its maturity, simplicity, and built-in redundancy. Also described are the results of studies performed to increase the performance of the OMS engine either by using LOX/hydrocarbon propellants or by converting to a pump fed system to increase chamber pressure and area ratio.

Experimental Calcium Silicate-Based Cement with and without Zirconium Oxide Modulates Fibroblasts Viability.

PubMed

Slompo, Camila; Peres-Buzalaf, Camila; Gasque, Kellen Cristina da Silva; Damante, Carla Andreotti; Ordinola-Zapata, Ronald; Duarte, Marco Antonio Hungaro; de Oliveira, Rodrigo Cardoso

2015-01-01

The aim of this study was to verify whether the use of zirconium oxide as a radiopacifier of an experimental calcium silicate-based cement (WPCZO) leads to cytotoxicity. Fibroblasts were treated with different concentrations (10 mg/mL, 1 mg/mL, and 0.1 mg/mL) of the cements diluted in Dulbecco's modified Eagle's medium (DMEM) for periods of 12, 24, and 48 h. Groups tested were white Portland cement (WPC), white Portland cement with zirconium oxide (WPCZO), and white mineral trioxide aggregate Angelus (MTA). Control group cells were not treated. The cytotoxicity was evaluated through mitochondrial-activity (MTT) and cell-density (crystal violet) assays. All cements showed low cytotoxicity. In general, at the concentration of 10 mg/mL there was an increase in viability of those groups treated with WPC and WPCZO when compared to the control group (p<0.05). A similar profile for the absorbance values was noted among the groups: 10 mg/mL presented an increase in viability compared to the control group. On the other hand, smaller concentrations presented a similar or lower viability compared to the control group, in general. A new dental material composed of calcium silicate-based cement with 20% zirconium oxide as the radiopacifier showed low cytotoxicity as a promising material to be exploited for root-end filling.

Use of barium-strontium carbonatite for flux welding and surfacing of mining machines

NASA Astrophysics Data System (ADS)

Kryukov, R. E.; Kozyrev, N. A.; Usoltsev, A. A.

2017-09-01

The results of application of barium-strontium carbonatite for modifying and refining iron-carbon alloys, used for welding and surfacing in ore mining and smelting industry, are generalized. The technology of manufacturing a flux additive containing 70 % of barium-strontium carbonatite and 30 % of liquid glass is proposed. Several compositions of welding fluxes based on silicomanganese slag were tested. The flux additive was introduced in an amount of 1, 3, 5 %. Technological features of welding with the application of the examined fluxes are determined. X-ray spectral analysis of the chemical composition of examined fluxes, slag crusts and weld metal was carried out, as well as metallographic investigations of welded joints. The principal possibility of applying barium-strontium carbonatite as a refining and gas-protective additive for welding fluxes is shown. The use of barium-strontium carbonatite reduces the contamination of the weld seam with nonmetallic inclusions: non-deforming silicates, spot oxides and brittle silicates, and increases the desulfurizing capacity of welding fluxes.

Nanoparticle induced piezoelectric, super toughened, radiation resistant, multi-functional nanohybrids.

PubMed

Tiwari, Vimal K; Shripathi, T; Lalla, N P; Maiti, Pralay

2012-01-07

We have developed multifunctional nanohybrids of poly(vinylidene fluoride-co-chlorotrifluoroethylene) (CTFE) with a small percentage of surface modified inorganic layered silicate showing dramatic improvement in toughness, radiation resistant and piezoelectric properties vis-à-vis pristine polymer. Massive intercalation (d(001) 1.8 → 3.9 nm) of polymer inside the nanoclay galleries and unique crystallization behavior of the fluoropolymer on the surface of individual silicate layer has been reported. Toughness in the nanohybrid increases more than three orders of magnitude as compared to pure CTFE. High energy radiation (80 MeV Si(+7)) causes chain session, amorphization and creates olefinic bonds in the pure polymer while the nanohybrids are radiation resistant at a similar dose. Nanoclay induces the metastable piezoelectric β-phase in CTFE, suitable for sensor and actuator application. Molecular level changes after irradiation and controlled morphology for smart membrane have been confirmed by using spectroscopy, sol-gel technique, surface morphology studies and in situ residual gas analysis.

Zeta potentials in the flotation of oxide and silicate minerals.

PubMed

Fuerstenau, D W; Pradip

2005-06-30

Adsorption of collectors and modifying reagents in the flotation of oxide and silicate minerals is controlled by the electrical double layer at the mineral-water interface. In systems where the collector is physically adsorbed, flotation with anionic or cationic collectors depends on the mineral surface being charged oppositely. Adjusting the pH of the system can enhance or prevent the flotation of a mineral. Thus, the point of zero charge (PZC) of the mineral is the most important property of a mineral in such systems. The length of the hydrocarbon chain of the collector is important because of chain-chain association enhances the adsorption once the surfactant ions aggregate to form hemimicelles at the surface. Strongly chemisorbing collectors are able to induce flotation even when collector and the mineral surface are charged similarly, but raising the pH sufficiently above the PZC can repel chemisorbing collectors from the mineral surface. Zeta potentials can be used to delineate interfacial phenomena in these various systems.

Characteristics of sedimentary organic matter in coastal and depositional areas in the Baltic Sea

NASA Astrophysics Data System (ADS)

Winogradow, A.; Pempkowiak, J.

2018-05-01

As organic matter (OM) is readily mineralized to carbon dioxide (Smith and Hollibangh, 1993; Emerson and Hedges, 2002; Szymczycha et al., 2017) it has a direct link to the carbon dioxide abundance in seawater and an indirect influence on the carbon dioxide concentration in the atmosphere (Emerson and Hedges, 2002; Schulz and Zabel, 2006). OM is a quantitatively minor yet important component of seawater. OM in seawater can originate from internal sources (marine, or planktonic, or autochthonous OM) or external sources (terrestrial, or allochtonous OM) (Maksymowska et al., 2000; Emerson and Hedges, 2002; Turnewitsch et al., 2007; Arndt et al., 2013). It is commonly divided into two fractions: dissolved (DOM) and particulate (POM). Organic carbon (OC) is, most often, used as a measure of OM.

Trends in otitis media-related health care use in the United States, 2001-2011.

PubMed

Marom, Tal; Tan, Alai; Wilkinson, Gregg S; Pierson, Karen S; Freeman, Jean L; Chonmaitree, Tasnee

2014-01-01

Otitis media (OM) is a leading cause of pediatric health care visits and the most frequent reason children consume antibiotics or undergo surgery. During recent years, several interventions have been introduced aiming to decrease OM burden. To study the trend in OM-related health care use in the United States during the pneumococcal conjugate vaccine (PCV) era (2001-2011). An analysis of an insurance claims database of a large, nationwide managed health care plan was conducted. Enrolled children aged 6 years or younger with OM visits were identified. Annual OM visit rates, OM-related complications, and surgical interventions were analyzed. Overall, 7.82 million unique children (5.51 million child-years) contributed 6.21 million primary OM visits; 52% were boys and 48% were younger than 2 years. There was a downward trend in OM visit rates from 2004 to 2011, with a significant drop that coincided with the advent of the 13-valent vaccine (PCV-13) in 2010. The observed OM visit rates in 2010 (1.00/child-year) and 2011 (0.81/child-year) were lower than the projected rates based on the 2005-2009 trend had there been no intervention (P < .001). Recurrent OM (≥3 OM visits within 6-month look-back) rates decreased at 0.003/child-year (95% CI, 0.002-0.004/child-year) in 2001-2009 and at 0.018/child-year (95% CI, 0.008-0.028/child-year) in 2010-2011. In the PCV-13 premarket years, there was a stable rate ratio (RR) between OM visit rates in children younger than 2 years and in those aged 2 to 6 years (RR, 1.38; 95% CI, 1.38-1.39); the RR decreased significantly (P < .001) during the transition year 2010 (RR 1.32; 95% CI, 1.31-1.33) and the postmarket year 2011 (RR 1.01; 95% CI, 1.00-1.02). Tympanic membrane perforation/otorrhea rates gradually increased (from 3721 per 100,000 OM child-years in 2001 to 4542 per 100,000 OM child-years in 2011; P < .001); the increase was significant only in the older children group. Mastoiditis rates substantially decreased (from 61 per 100,000 child-years in 2008 to 37 per 100,000 child-years in 2011; P < .001). Ventilating tube insertion rate decreased by 19% from 2010 to 2011 (P = .03). There was an overall downward trend in OM-related health care use from 2001 to 2011. The significant reduction in OM visit rates in 2010-2011 in children younger than 2 years coincided with the advent of PCV-13. Although tympanic membrane perforation/otorrhea rates steadily increased during that period, mastoiditis and ventilating tube insertion rates decreased in the last years of the study.

Spatio-temporal variations of organic matter along the Seine estuary (France)

NASA Astrophysics Data System (ADS)

Thibault, Alexandre; Huguet, Arnaud; Parlanti, Edith; Derenne, Sylvie

2017-04-01

Organic matter (OM) in aquatic systems plays an important role in water quality and biogeochemical processes. It is thus essential to characterize OM, especially in estuaries which are the place of the transport and the reactivity of natural and anthropogenic compounds. However, the characterization of OM in estuaries is complex due to its heterogeneity and variability in addition to specific features of these environments (salinity, turbidity…). Two types of aquatic OM, namely particulate (POM) and dissolved (DOM) are commonly distinguished by filtration. Due to its low concentration in estuaries (few mg/L), DOM has to be concentrated prior to its molecular (or structural) analysis. However, this step also induces the concentration of salts which are predominant (several g/L) in coastal environments. To overcome this issue, DOM has been isolated by a combination of reverse osmosis and electrodialysis. This method is more efficient than classical ones (ultrafiltration, solid phase techniques) in the isolation of representative DOM material. As a result, DOM can be characterized just as POM and sedimentary OM. The aim of this study is to characterize the spatiotemporal variability of DOM, POM and sedimentary OM along the Seine estuary (France) so as to understand its role in the functioning of this ecosystem. To this end, 5 sampling campaigns were performed in the Seine estuary between January 2015 and April 2016, during which large water samples (100 L) and sediment cores (10 cm) were collected. These campaigns covered the whole estuary. The three OM pools were analyzed through (i) elemental and isotopic analyses (Elemental Analysis-isotope ratio Mass Spectrometry, 14C ages) and (ii) structural analyses (13C solid state nuclear magnetic resonance, pyrolysis coupled with gas chromatography and mass spectrometry and ultrahigh resolution mass spectrometry), allowing to obtain both bulk and molecular information. The combination of these chemical characterization and statistical analyses shows that the 2 main factors driving the composition of OM in the Seine estuary are the OM pool (DOM, POM or sedimentary) and its origin (marine vs freshwater) whereas seasonal variations appear less pronounced. Indeed, OM exhibits higher C/N ratio and is richer in aliphatic and alkoxyl carbons than POM and sedimentary OM. The latter share the same elemental and isotopic composition but POM is enriched in aliphatic carbons with respect to sedimentary OM. These results confirm the higher hydrophilic nature of DOM when compared to POM and that the sedimentary OM in the Seine estuary is close to POM. Moreover, the dating of OM shows that DOM and POM are recent (> 1950 AD) contrary to sedimentary OM. When going downstream along the estuary, DOM is depleted in aliphatic carbons and enriched in alkoxyl carbons, the reverse trend being observed for POM. Both are enriched in δ13C.

Changes in soil parameters under continuous plastic mulching in strawberry cultivation

NASA Astrophysics Data System (ADS)

Muñoz, Katherine; Diehl, Dörte; Scopchanova, Sirma; Schaumann, Gabriele E.

2016-04-01

Plastic mulching (PM) is a widely used practice in modern agriculture because they generate conditions for optimal yield rates and quality. However, information about long-term effects of PC on soil quality parameters is scarce. The aim of this study is to compare the effect of three different mulching managements on soil quality parameters. Sampling and methodology: Three different managements were studied: Organic mulching (OM), 2-years PM and 4-years PM. Soil samples were collected from irrigated fields in 0-5, 5-10 and 10-30 cm depths and analyzed for water content (WC), pH, dissolved organic carbon (DOC), total soil carbon (Ctot) and cation exchange capacity (CECeff). Results and discussion: Mulching management has an influence on soil parameters. The magnitude of the effects is influenced by the type (organic agriculture practice vs. plastic mulching practice) and duration of the mulching. PM modified the water distribution through the soil column. WC values at the root zone were in average 10% higher compared to those measured at the topsoil. Under OM, the WC was lower than under PM. The pH was mainly influenced by the duration of the managements with slightly higher values after 4 than after 2-years PM. Under PM, aqueous extracts of the topsoil (0-5 cm depth) contained in average with 8.5±1.8 mg/L higher DOC than in 10-30 cm depth with 5.6±0.5 mg/L, which may indicate a mobilization of organic components in the upper layers. After 4-years PM, Ctot values were slightly higher than after 2-years PM and after OM. Surprisingly, after 4-years PM, CECeff values were with 138 - 157 mmolc/kg almost 2-fold higher than after 2-years PM and OM which had with 74 - 102 mmolc/kg comparable CECeff values. Long-term PM resulted in changes of soil pH and slightly increased Ctot which probably enhanced the CECeff of the soil. However, further investigations of the effect of PM on stability of soil organic matter and microbial community structure are needed.

Synthesis and Characterization of Mesoporous Silica Functionalized with Calix[4]arene Derivatives

PubMed Central

Alahmadi, Sana M.; Mohamad, Sharifah; Maah, Mohd Jamil

2012-01-01

This work reports a new method to covalently attach calix[4]arene derivatives onto MCM-41, using a diisocyanate as a linker. The modified mesoporous silicates were characterized by fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA) and elemental analysis. The FTIR spectra and TGA analysis verified that the calix[4]arene derivates are covalently attached to the mesoporous silica. The preservation of the MCM-41 channel system was checked by X-ray diffraction and nitrogen adsorption analysis. PMID:23202977

European Science Notes Information Bulletin. Reports on Current European and Middle Eastern Science

DTIC Science & Technology

1993-01-01

network. Mechanical properties of ormolytes can tion of TiO2 to "open-up" the structure tb.r Li be modified by altering the structure of the silicate...Cambridge es. The group from the University of California, group has demonstrated that the color (wavelength) Santa Barbara, and Uniax Corporation...A.J. of the electroluminescence can be tuned over a Heeger, F. Wudi, P. Smith) reported on their work range of colors . with polymer 12 in several talks

The molecular characteristics of pyrogenic organic materials and their aqueous leachates

NASA Astrophysics Data System (ADS)

Wozniak, A. S.; Hatcher, P.; Mitra, S.; Bostick, K. W.; Zimmerman, A. R.

2016-12-01

Pyrogenic organic matter (Py-OM), or black carbon, is known to impact soil chemistry, pollutant transport, regional and global carbon cycling, and climate. Py-OM is incorporated into soils via atmospheric deposition (e.g., from biomass, fossil fuel combustion) or direct applications by humans (e.g., biochars applied for agricultural production). Due to its presumed refractory and immobile nature, soil Py-OM is thought to be efficiently buried, sequestering atmospheric CO2. However, tracers of dissolved Py-OM (Py-DOM) have been detected in appreciable quantities in riverine, estuarine, and oceanic waters suggesting that Py-OM is more mobile in the environment than expected. The molecular characteristics of Py-OM are likely to be a controlling factor in the quantities and impacts of Py-DOM released to aqueous systems. Yet, little is known about the detailed molecular composition of these materials, let alone how those molecular characteristics vary with combustion conditions or are altered by environmental processes. Here, we examine oak and grass Py-OM (combusted over a range of temperatures), natural Py-OM (chars aged in the environment for variable lengths of time), and their Py-DOM leachates via nuclear magnetic resonance spectroscopy (NMR) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Multi-CP 13C NMR analyses of Py-OM materials and 1H NMR analyses of corresponding Py-DOM leachates reveal that Py-OM combustion temperature, environmental exposure, and molecular characteristics are reflected in Py-DOM quantities and characteristics. The relative amounts of aromatic C in Py-OM 1) decreases with environmental exposure, the relative oxygen-content in both Py-OM and Py-DOM, and the amount of Py-DOC released per g of Py-OC but 2) is positively correlated with combustion temperature and the relative contributions of acetate and aliphatic hydrogens (CH2) in Py-DOM. Preliminary FTICR-MS analyses show Py-DOM produced from oak at 400 °C to have lost carbohydrate-like compounds found in 250 °C Py-DOM and to contain an abundance of oxygenated aromatic compounds. Oak combusted at 650 °C produces Py-DOM characterized by high H/C, low O/C compounds. The results from this work will improve our understanding of Py-OM transport within and between terrestrial and aqueous systems.

Using Novel Laboratory Incubations and Field Experiments to Identify the Source and Fate of Reactive Organic Carbon in an Arsenic-contaminated Aquifer System

NASA Astrophysics Data System (ADS)

Stahl, M.; Tarek, M. H.; Badruzzaman, B.; Harvey, C. F.

2017-12-01

Characterizing the sources and fate of organic matter (OM) within aquifer systems is key to our understanding of both the broader global carbon cycle as well as the quality of our groundwater resources. The linkage between the subsurface carbon cycle and groundwater quality is perhaps nowhere more apparent than in the aquifer systems of South and Southeast Asia, where the contamination of groundwater with geogenic arsenic (As) is widespread and threatens the health of millions of individuals. OM fuels the biogeochemical processes driving As mobilization within these aquifers, however the source (i.e., modern surface-derived or aged sedimentary OM) of the reactive OM is widely debated. To characterize the sources of OM driving aquifer redox processes we tracked DIC and DOC concentrations and isotopes (stable and radiocarbon) along groundwater flow-paths and beneath an instrumented study pond at a field site in Bangladesh. We also conducted a set of novel groundwater incubation experiments, where we carbon-dated the DOC at the start and end of a experiment in order to determine the age of the OM that was mineralized. Our carbon/isotope balance reveals that aquifer recharge introduces a large quantity of young (i.e. near modern) OM that is efficiently mineralized within the upper few meters of the aquifer, effectively limiting this pool of reactive surface-sourced OM from being transported deeper into the aquifer where significant As mobilization takes place. The OM mineralized past the upper few meters is an aged, sedimentary source. Consistent with our field data, our incubation experiments show that past the upper few meters of the aquifer the reactive DOC is significantly older than the bulk DOC and has an age consistent with sedimentary OM. Combining our novel set of incubation experiments and a carbon/isotope balance along groundwater flow-paths and beneath our study pond we have identified the sources of reactive OM across different aquifer depths in a Bangladeshi aquifer. Our insight into the subsurface carbon cycle reveals that sediment-sourced OM is driving the biogeochemical processes responsible for high groundwater As concentrations and that exogenous sources of OM introduced by anthropogenic activities are unlikely to have had a significant effect on the concentrations of As presently observed at our site.

Effects of complexation between organic matter (OM) and clay mineral on OM pyrolysis

NASA Astrophysics Data System (ADS)

Bu, Hongling; Yuan, Peng; Liu, Hongmei; Liu, Dong; Liu, Jinzhong; He, Hongping; Zhou, Junming; Song, Hongzhe; Li, Zhaohui

2017-09-01

The stability and persistence of organic matter (OM) in source rocks are of great significance for hydrocarbon generation and the global carbon cycle. Clay-OM associations commonly occur in sedimentation and diagenesis processes and can influence the pyrolytic behaviors of OM. In this study, clay-OM complexes, i.e., interlayer clay-OM complexes and clay-OM mixture, were prepared and exposed to high-pressure pyrolysis conditions in confined gold capsule reactors to assess variations in OM pyrolysis products in the presence of clay minerals. Three model organic compounds, octadecanoic acid (OA), octadecy trimethyl ammonium bromide (OTAB), and octadecylamine (ODA), were employed and montmorillonite (Mt) was selected as the representative clay mineral. The solid acidity of Mt plays a key role in affecting the amount and composition of the pyrolysis gases generated by the clay-OM complexes. The Brønsted acid sites significantly promote the cracking of hydrocarbons through a carbocation mechanism and the isomerization of normal hydrocarbons. The Lewis acid sites are primarily involved in the decarboxylation reaction during pyrolysis and are responsible for CO2 generation. Mt exhibits either a catalysis effect or pyrolysis-inhibiting during pyrolysis of a given OM depending on the nature of the model organic compound and the nature of the clay-OM complexation. The amounts of C1-5 hydrocarbons and CO2 that are released from the Mt-OA and Mt-ODA complexes were higher than those of the parent OA and ODA, respectively, indicating a catalysis effect of Mt. In contrast, the amount of C1-5 hydrocarbons produced from the pyrolysis of Mt-OTAB complexes was lower than that of OTAB, which we attribute to an inhibiting effect of Mt. This pyrolysis-inhibiting effect works through the Hoffmann elimination that is promoted by the catalysis of the Brønsted acid sites of Mt, therefore releasing smaller amounts of gas hydrocarbons than the nucleophilic reaction that is induced by the halide ions in OTAB. In particular, the interlayer space of Mt acts as an 'amplifier' that magnifies the above-mentioned catalysis or pyrolysis-inhibiting effect, due to the greater number of Brønsted acid sites with high acidity in the interlayer space. These findings are potentially important for understanding the storage and transfer mechanisms of natural OM in sedimentation and diagenesis processes.

Quantification of amine functional groups and their influence on OM/OC in the IMPROVE network

NASA Astrophysics Data System (ADS)

Kamruzzaman, Mohammed; Takahama, Satoshi; Dillner, Ann M.

2018-01-01

Recently, we developed a method using FT-IR spectroscopy coupled with partial least squares (PLS) regression to measure the four most abundant organic functional groups, aliphatic C-H, alcohol OH, carboxylic acid OH and carbonyl C=O, in atmospheric particulate matter. These functional groups are summed to estimate organic matter (OM) while the carbon from the functional groups is summed to estimate organic carbon (OC). With this method, OM and OM/OC can be estimated for each sample rather than relying on one assumed value to convert OC measurements to OM. This study continues the development of the FT-IR and PLS method for estimating OM and OM/OC by including the amine functional group. Amines are ubiquitous in the atmosphere and come from motor vehicle exhaust, animal husbandry, biomass burning, and vegetation among other sources. In this study, calibration standards for amines are produced by aerosolizing individual amine compounds and collecting them on PTFE filters using an IMPROVE sampler, thereby mimicking the filter media and collection geometry of ambient standards. The moles of amine functional group on each standard and a narrow range of amine-specific wavenumbers in the FT-IR spectra (wavenumber range 1 550-1 500 cm-1) are used to develop a PLS calibration model. The PLS model is validated using three methods: prediction of a set of laboratory standards not included in the model, a peak height analysis and a PLS model with a broader wavenumber range. The model is then applied to the ambient samples collected throughout 2013 from 16 IMPROVE sites in the USA. Urban sites have higher amine concentrations than most rural sites, but amine functional groups account for a lower fraction of OM at urban sites. Amine concentrations, contributions to OM and seasonality vary by site and sample. Amine has a small impact on the annual average OM/OC for urban sites, but for some rural sites including amine in the OM/OC calculations increased OM/OC by 0.1 or more.

Comparative organic geochemistry of Indian margin (Arabian Sea) sediments: estuary to continental slope

NASA Astrophysics Data System (ADS)

Cowie, G.; Mowbray, S.; Kurian, S.; Sarkar, A.; White, C.; Anderson, A.; Vergnaud, B.; Johnstone, G.; Brear, S.; Woulds, C.; Naqvi, S. W.; Kitazato, H.

2014-02-01

Surface sediments from sites across the Indian margin of the Arabian Sea were analysed for their carbon and nitrogen compositions (elemental and stable isotopic), grain size distributions and biochemical indices of organic matter (OM) source and/or degradation state. Site locations ranged from the estuaries of the Mandovi and Zuari rivers to depths of ~ 2000 m on the continental slope, thus spanning nearshore muds and sands on the shelf and both the semi-permanent oxygen minimum zone (OMZ) on the upper slope (~ 200-1300 m) and the seasonal hypoxic zone that impinges on the shelf. Source indices showed mixed marine and terrigenous OM within the estuaries, and overwhelming predominance (80%+) of marine OM on the shelf and slope. Thus, riverine OM is heavily diluted by autochthonous marine OM and/or is efficiently remineralised within or immediately offshore of the estuaries. Any terrigenous OM that is exported appears to be retained in nearshore muds; lignin phenols indicate that the small terrigenous OM content of slope sediments is of different origin, potentially from rivers to the north. Organic C contents of surface shelf and slope sediments varied from < 0.5 wt % in relict shelf sands to over 7 wt % at slope sites within the OMZ, decreasing to ≤ 1 wt % at 2000 m. Major variability (~ 5 wt %) was found at slope sites within the OMZ of similar depth and near-identical bottom-water oxygen concentration. A strong relationship between organic C and sediment grain size was seen for sediments within the OMZ, but lower C loadings were found for sites on the shelf and below the OMZ. Diagenetic indices confirmed that lower C content below the OMZ is associated with greater extent of OM degradation, but that C-poor shelf sediments are not consistently more degraded than those within the OMZ. Together, the results indicate that OM enrichment on the upper slope can be explained by physical controls (winnowing and/or dilution) on the shelf and progressive OM degradation with increasing oxygen exposure below the OMZ. Reduced oxygen exposure may contribute to OM enrichment at some sites within the OMZ, but hydrodynamic processes are the overriding control on sediment OM distribution.

Reduction in all-cause otitis media-related outpatient visits in children after PCV10 introduction in Brazil

PubMed Central

Sartori, Ana L.; Minamisava, Ruth; Bierrenbach, Ana L.; Toscano, Cristiana M.; Afonso, Eliane T.; Morais-Neto, Otaliba L.; Antunes, José L. F.; Cristo, Elier B.

2017-01-01

Few studies have reported the effect of 10-valent pneumococcal conjugate vaccine (PCV10) on otitis media (OM) in infants. In particular, no population-based study in upper-middle income countries is available. In 2010, Brazil introduced PCV10 into its routine National Immunization Program using a 3+1 schedule. We measured the impact of PCV10 on all-cause OM in children. An interrupted time-series analysis was conducted in Goiânia/Brazil considering monthly rates (per 100,000) of all-cause OM outpatient visits in children aged 2–23 months. We used case-based data from the Outpatient Visits Information System of the Unified Health System coded for ICD-10 diagnosis for the period of August/2008 to July/2015. As a comparator, we used rates of outpatient visits due to all-other causes. The relative reduction of all-cause OM and all-other causes of outpatient visits were calculated as the difference between the predicted and observed cumulative rates of the PCV10 post-vaccination period. We then subtracted the relative reduction of all-other causes of outpatient visits from all-cause OM to obtain the impact of PCV10 on OM. In total, 6,401 OM outpatient visits were recorded in 4,793 children aged 2–23 months. Of these, 922 (19.2%) children had more than one OM episode. A significant reduction in all-cause OM visits was observed (50.7%; 95%CI: 42.2–59.2%; p = 0.013), while the reduction in visits due to all-other causes was 7.7% (95% CI 0.8–14.7%; p<0.001). The impact of PCV10 on all-cause OM was thus estimated at 43.0% (95%CI 41.4–44.5). This is the first study to show significant PCV10 impact on OM outpatient visits in infants in a developing country. Our findings corroborate the available evidence from developed countries. PMID:28594913

Reduction in all-cause otitis media-related outpatient visits in children after PCV10 introduction in Brazil.

PubMed

Sartori, Ana L; Minamisava, Ruth; Bierrenbach, Ana L; Toscano, Cristiana M; Afonso, Eliane T; Morais-Neto, Otaliba L; Antunes, José L F; Cristo, Elier B; Andrade, Ana Lucia

2017-01-01

Few studies have reported the effect of 10-valent pneumococcal conjugate vaccine (PCV10) on otitis media (OM) in infants. In particular, no population-based study in upper-middle income countries is available. In 2010, Brazil introduced PCV10 into its routine National Immunization Program using a 3+1 schedule. We measured the impact of PCV10 on all-cause OM in children. An interrupted time-series analysis was conducted in Goiânia/Brazil considering monthly rates (per 100,000) of all-cause OM outpatient visits in children aged 2-23 months. We used case-based data from the Outpatient Visits Information System of the Unified Health System coded for ICD-10 diagnosis for the period of August/2008 to July/2015. As a comparator, we used rates of outpatient visits due to all-other causes. The relative reduction of all-cause OM and all-other causes of outpatient visits were calculated as the difference between the predicted and observed cumulative rates of the PCV10 post-vaccination period. We then subtracted the relative reduction of all-other causes of outpatient visits from all-cause OM to obtain the impact of PCV10 on OM. In total, 6,401 OM outpatient visits were recorded in 4,793 children aged 2-23 months. Of these, 922 (19.2%) children had more than one OM episode. A significant reduction in all-cause OM visits was observed (50.7%; 95%CI: 42.2-59.2%; p = 0.013), while the reduction in visits due to all-other causes was 7.7% (95% CI 0.8-14.7%; p<0.001). The impact of PCV10 on all-cause OM was thus estimated at 43.0% (95%CI 41.4-44.5). This is the first study to show significant PCV10 impact on OM outpatient visits in infants in a developing country. Our findings corroborate the available evidence from developed countries.

Biochemical resistance of pyrogenic organic matter in fire-affected mineral soils of Southern Europe

NASA Astrophysics Data System (ADS)

Knicker, H.; González Vila, F. J.; Clemente Salas, L.

2012-04-01

Incorporated into the soil, naturally formed pyrogenic organic matter (PyOM) is considered as highly recalcitrant, but direct estimation of PyOM decomposition rates are scarce. With this aim in mind, we subjected organic matter (OM) of fire-affected and unaffected soils to biochemical degradation under laboratory conditions and monitored CO2 production over a period of seven months. The soils derived from fire affected and unaffected areas of the Sierra de Aznalcóllar and the Doñana National Park, Southern Spain. Virtual fractionation of the solid-state 13C nuclear magnetic resonance (NMR) spectra of the fire affected soils into fire-unaffected soil organic matter (SOM) and PyOM yielded charcoal C contributions of 30 to 50% to the total organic C (Corg) of the sample derived from the Aznalcóllar region. Fitting the respiration data with a double exponential decay model revealed a fast carbon flush during the first three weeks of the experiment. Solid-state 13C NMR spectroscopy evidenced the contribution of aromatic moieties of the PyOM to this initial carbon release and to the biosynthesis of new microbial biomass. The input of PyOM resulted in an increase of the mean residence time (MRT) of the slow OM pool of the soil by a factor of 3 to 4 to approximately 40 years which rises doubts rises doubts about the presumed big influence of PyOM as an additional C-sink in soils. On the other hand, although being small the difference in turnover rates is evident and has some major implication with respect to long-term alteration of the chemical composition of OM in fire-affected soils. Based on the obtained results and the analysis of PyOM in other soil systems, a conceptual model is presented which can explain the different behavior of PyOM under different soil conditions.

The clinical relevance of omega-3 fatty acids in the management of hypertriglyceridemia.

PubMed

Backes, James; Anzalone, Deborah; Hilleman, Daniel; Catini, Julia

2016-07-22

Hypertriglyceridemia (triglycerides > 150 mg/dL) affects ~25 % of the United States (US) population and is associated with increased cardiovascular risk. Severe hypertriglyceridemia (≥ 500 mg/dL) is also a risk factor for pancreatitis. Three omega-3 fatty acid (OM3FA) prescription formulations are approved in the US for the treatment of adults with severe hypertriglyceridemia: (1) OM3FA ethyl esters (OM3EE), a mixture of OM3FA ethyl esters, primarily eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (Lovaza®, Omtryg™, and generics); (2) icosapent ethyl (IPE), EPA ethyl esters (Vascepa®); and (3) omega-3 carboxylic acids (OM3CA), a mixture of OM3FAs in free fatty acid form, primarily EPA, DHA, and docosapentaenoic acid (Epanova®). At approved doses, all formulations substantially reduce triglyceride and very-low-density lipoprotein levels. DHA-containing formulations may also increase low-density lipoprotein cholesterol. However, this is not accompanied by increased non-high-density lipoprotein cholesterol, which is thought to provide a better indication of cardiovascular risk in this patient population. Proposed mechanisms of action of OM3FAs include inhibition of diacylglycerol acyltransferase, increased plasma lipoprotein lipase activity, decreased hepatic lipogenesis, and increased hepatic β-oxidation. OM3CA bioavailability (area under the plasma concentration-time curve from zero to the last measurable concentration) is up to 4-fold greater than that of OM3FA ethyl esters, and unlike ethyl esters, the absorption of OM3CA is not dependent on pancreatic lipase hydrolysis. All three formulations are well tolerated (the most common adverse events are gastrointestinal) and demonstrate a lack of drug-drug interactions with other lipid-lowering drugs, such as statins and fibrates. OM3FAs appear to be an effective treatment option for patients with severe hypertriglyceridemia.

Linking Intra-Aggregate Pore Size Distribution with Organic Matter Decomposition Status, Evidence from FTIR and X-Ray Tomography

NASA Astrophysics Data System (ADS)

Toosi, E. R.; Quigley, M.; Kravchenko, A. N.

2014-12-01

It has been reported that conversion of intensively cultivated lands to less disturbed systems enhances soil OM storage capacity, primarily through OM stabilization in macroaggregates. We hypothesized that the potential for OM stabilization inside macro-aggregates is influenced by presence and abundance of intra-aggregate pores. Pores determine microbial access to OM and regulate diffusion of solution/gases within aggregates which drives microbial functioning. We investigated the influence of longterm disturbance intensity on soil OM composition and its relation to pore size distribution within macroaggregates. We used quantitative FTIR to determine OM decomposition status and X-ray micro-tomography to assess pore size distribution in macroaggregates as affected by management and landuse. Macroaggregates 4-6 mm in size where selected from topsoil under long term conventional tillage (CT), cover-crop (CC), and native succession vegetation (NS) treatments at Kellogg Biological Station, Michigan. Comparison of main soil OM functional groups suggested that with increasing disturbance intensity, the proportion of aromatic and carboxylic/carbohydrates associated compounds increased and it was concomitant with a decrease in the proportion of aliphatic associated compounds and lignin derivatives. Further, FTIR-based decomposition indices revealed that overall decomposition status of macroaggregates followed the pattern of CT > CC ≈ NS. X-ray micro-tomography findings suggested that greater OM decomposition within the macroaggregates was associated with i) greater percent of pores >13 micron in size within the aggregates, as well as ii) greater proportion of small to medium pores (13-110 micron). The results develop previous findings, suggesting that shift in landuse or management indirectly affects soil OM stabilization through alteration of pore size distribution within macroaggregates that itself, is coupled with OM decomposition status.

Cost-Effectiveness analysis of Recovery Management Checkups (RMC) for adults with chronic substance use disorders: evidence from a four-year randomized trial

PubMed Central

McCollister, Kathryn E.; French, Michael T.; Freitas, Derek M.; Dennis, Michael L.; Scott, Christy K.; Funk, Rodney R.

2013-01-01

Aims This study performs the first cost-effectiveness analysis (CEA) of Recovery Management Checkups (RMC) for adults with chronic substance use disorders. Design Cost-effectiveness analysis of a randomized clinical trial of RMC. Participants were randomly assigned to a control condition of outcome monitoring (OM-only) or the experimental condition OM-plus-RMC, with quarterly follow-up for four years. Setting Participants were recruited from the largest central intake unit for substance abuse treatment in Chicago, Illinois, USA. Participants 446 participants who were 38 years old on average, 54 percent male, and predominantly African American (85%). Measurements Data on the quarterly cost per participant come from a previous study of OM and RMC intervention costs. Effectiveness is measured as the number of days of abstinence and number of substance-use-related problems. Findings Over the four-year trial, OM-plus-RMC cost on average $2,184 more than OM-only (p<0.01). Participants in OM-plus-RMC averaged 1,026 days abstinent and had 89 substance-use-related problems. OM-only averaged 932 days abstinent and reported 126 substance-use-related problems. Mean differences for both effectiveness measures were statistically significant (p<0.01). The incremental cost-effectiveness ratio for OM-plus-RMC was $23.38 per day abstinent and $59.51 per reduced substance-related problem. When additional costs to society were factored into the analysis, OM-plus-RMC was less costly and more effective than OM-only. Conclusions Recovery Management Checkups are a cost-effective and potentially cost-saving strategy for promoting abstinence and reducing substance-use-related problems among chronic substance users. PMID:23961833

Microgel-in-Microgel Biopolymer Delivery Systems: Controlled Digestion of Encapsulated Lipid Droplets under Simulated Gastrointestinal Conditions.

PubMed

Ma, Da; Tu, Zong-Cai; Wang, Hui; Zhang, Zipei; McClements, David Julian

2018-04-18

Structural design principles are increasingly being used to develop colloidal delivery systems for bioactive agents. In this study, oil droplets were encapsulated within microgel-in-microgel systems. Initially, a nanoemulsion was formed that contained small whey protein-coated oil droplets ( d 43 = 211 nm). These oil droplets were then loaded into either carrageenan-in-alginate (O/M C /M A ) or alginate-in-carrageenan (O/M A /M C ) microgels. A vibrating nozzle encapsulation unit was used to form the smaller inner microgels ( d 43 = 170-324 μm), while a hand-held syringe was used to form the larger outer microgels ( d 43 = 2200-3400 μm). Calcium alginate microgels (O/M A ) were more stable to simulated gastrointestinal tract (GIT) conditions than potassium carrageenan microgels (O/M C ), which was attributed to the stronger cross-links formed by divalent calcium ions than the monovalent potassium ions. As a result, the microgel-in-microgel systems had different gastrointestinal fates depending upon the nature of the external microgel phase; i.e., the O/M C /M A system was more resistant to rupture than the O/M A /M C system. The rate of lipid digestion under simulated small intestine conditions decreased in the following order: free oil droplets > O/M C > O/M A > O/M A /M C > O/M C /M A . This effect was attributed to differences in the integrity and dimensions of the microgels in the small intestine, because a hydrogel network surrounding the oil droplets inhibits lipid hydrolysis by lipase. The structured microgels developed in this study may have interesting applications for the protection or controlled release of bioactive agents.

Pediatric otitis media in Fiji: Survey findings 2015.

PubMed

Fang, Te-Yung; Rafai, Eric; Wang, Pa-Chun; Bai, Chiy-Huey; Jiang, Peng-Long; Huang, Shu-Nuan; Chen, You-Ju; Chao, Yi-Ting; Wang, Chen-Hsu; Chang, Chia-Hsiu

2016-06-01

Otitis media (OM), as a common infectious disease, is a major cause of hearing impairment among the general population. OM remains a major public health threat in the Pacific islands, but the risks of OM have not been thoroughly explored in this region. The objective of this study is to investigate the prevalence, clinical features, and quality-of-life impacts of OM in Fiji. In the medical service trip entitled "Healing and Hope - Taiwan Cathay Heart and Hearing Medical Mission to Fiji" (TCHHMMF), we conducted a cross-sectional OM survey study in Suva and Sigatoka areas (Korolevu, Cuvu, and Lomawai) in the summer of 2015. The otitis media - 6 (OM-6) was used to survey the OM-related quality of life. In the 467 pediatric patients (aged 0-18 years old) screened, 13 (2.78%) have acute otitis media (AOM), 37 (7.92%) have otitis media with effusion (OME), and 19 (4.1%) have chronic otitis media (COM). Age (OR 0.53, 95% CI: 0.36-0.77) is a significant predictor of AOM, whereas male gender (OR 2.46, 95% CI: 1.13-5.37), smoke exposure (OR 2.81, 95% CI: 1.01-7.82), and concomitant chronic sinusitis (OR 6.05, 95% CI: 2.31-15.88) are significant predictors of OME. The mean OM-6 item scores are highest in caregiver concerns (3.8), physical suffering (3.7), and hearing loss (3.4) domains. OM is an important primary care disease in Fiji that remains under-served. It is critical to educate professionals, parents, and patients to detect and to improve care for OM. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Periodontal response to orthodontic tooth movement in diabetes-induced rats with or without periodontal disease.

PubMed

Ferreira, Camila Lopes; da Rocha, Vinicius Clemente; da Silva Ursi, Weber José; De Marco, Andrea Carvalho; Santamaria, Milton; Santamaria, Mauro Pedrine; Jardini, Maria Aparecida Neves

2018-03-01

Systemic conditions can influence orthodontic tooth movement. This study evaluates histologic periodontal responses to orthodontic tooth movement in diabetes-induced rats with or without periodontal disease. Forty Wistar rats were divided according their systemic condition (SC) into diabetic (D) and non-diabetic (ND) groups. Each group was subdivided into control (C), orthodontic tooth movement (OM), ligature-induced periodontitis (P) and ligature-induced periodontitis with orthodontic movement (P+OM) groups. Diabetes mellitus (DM) was induced with alloxan monohydrate, and after 30 days, the P group received a cotton ligature around their first lower molar crown. An orthodontic device was placed in OM and P+OM groups for 7 days, and the animals were then euthanized. Differences in OM between D and ND groups were not significant (6.87± 3.55 mm and 6.81 ± 3.28 mm, respectively), but intragroup analysis revealed statistically significant differences between the P+OM groups for both SCs. Bone loss was greater in the D group (0.16 ± 0.07 mm 2 ) than in the ND group (0.10 ± 0.03 mm 2 ). In intragroup analysis of the D condition, the P+OM group differed statistically from the other groups, while in the ND condition, the P+OM group was different from the C and OM groups. There was a statistically significant difference in bone density between D and ND conditions (18.03 ± 8.09% and 22.53 ± 7.72%) in the C, P, and P+OM groups. DM has deleterious effects on bone density and bone loss in the furcation region. These effects are maximized when associated with ligature-induced periodontitis with orthodontic movement. © 2018 American Academy of Periodontology.

Omeprazole Attenuates Pulmonary Aryl Hydrocarbon Receptor Activation and Potentiates Hyperoxia-Induced Developmental Lung Injury in Newborn Mice.

PubMed

Shivanna, Binoy; Zhang, Shaojie; Patel, Ananddeep; Jiang, Weiwu; Wang, Lihua; Welty, Stephen E; Moorthy, Bhagavatula

2015-11-01

Hyperoxia contributes to the development of bronchopulmonary dysplasia (BPD) in human preterm infants and a similar lung phenotype characterized by alveolar simplification in newborn mice. Omeprazole (OM) is a proton pump inhibitor that is used to treat humans with gastric acid related disorders. OM-mediated aryl hydrocarbon receptor (AhR) activation attenuates acute hyperoxic lung injury (HLI) in adult mice. Whether OM activates pulmonary AhR and protects C57BL/6J newborn mice against hyperoxia-induced developmental lung (alveolar and pulmonary vascular simplification, inflammation, and oxidative stress) injury (HDLI) is unknown. Therefore, we tested the hypothesis that OM will activate pulmonary AhR and mitigate HDLI in newborn mice. Newborn mice were treated daily with i.p. injections of OM at doses of 10 (OM10) or 25 (OM25) mg/kg while being exposed to air or hyperoxia (FiO2 of 85%) for 14 days, following which their lungs were harvested to determine alveolarization, pulmonary vascularization, inflammation, oxidative stress, vascular injury, and AhR activation. To our surprise, hyperoxia-induced alveolar and pulmonary vascular simplification, inflammation, oxidative stress, and vascular injury were augmented in OM25-treated animals. These findings were associated with attenuated pulmonary vascular endothelial growth factor receptor 2 expression and decreased pulmonary AhR activation in the OM25 group. We conclude that contrary to our hypothesis, OM decreases functional activation of pulmonary AhR and potentiates HDLI in newborn mice. These observations are consistent with our previous findings, which suggest that AhR activation plays a protective role in HDLI in newborn mice. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Cost-effectiveness analysis of Recovery Management Checkups (RMC) for adults with chronic substance use disorders: evidence from a 4-year randomized trial.

PubMed

McCollister, Kathryn E; French, Michael T; Freitas, Derek M; Dennis, Michael L; Scott, Christy K; Funk, Rodney R

2013-12-01

This study performs the first cost-effectiveness analysis (CEA) of Recovery Management Checkups (RMC) for adults with chronic substance use disorders. Cost-effectiveness analysis of a randomized clinical trial of RMC. Participants were assigned randomly to a control condition of outcome monitoring (OM-only) or the experimental condition OM-plus-RMC, with quarterly follow-up for 4 years. Participants were recruited from the largest central intake unit for substance abuse treatment in Chicago, Illinois, USA. A total of 446 participants who were 38 years old on average, 54% male, and predominantly African American (85%). Data on the quarterly cost per participant come from a previous study of OM and RMC intervention costs. Effectiveness is measured as the number of days of abstinence and number of substance use-related problems. Over the 4-year trial, OM-plus-RMC cost on average $2184 more than OM-only (P < 0.01). Participants in OM-plus-RMC averaged 1026 days abstinent and had 89 substance use-related problems. OM-only averaged 932 days abstinent and reported 126 substance use-related problems. Mean differences for both effectiveness measures were statistically significant (P < 0.01). The incremental cost-effectiveness ratio for OM-plus-RMC was $23.38 per day abstinent and $59.51 per reduced substance-related problem. When additional costs to society were factored into the analysis, OM-plus-RMC was less costly and more effective than OM-only. Recovery Management Checkups are a cost-effective and potentially cost-saving strategy for promoting abstinence and reducing substance use-related problems among chronic substance users. © 2013 Society for the Study of Addiction.

Size-controlled synthesis and formation mechanism of manganese oxide OMS-2 nanowires under reflux conditions with KMnO4 and inorganic acids

NASA Astrophysics Data System (ADS)

Zhang, Qin; Cheng, Xiaodi; Qiu, Guohong; Liu, Fan; Feng, Xionghan

2016-05-01

This study presents a simplified approach for size-controlled synthesis of manganese oxide octahedral molecular sieve (OMS-2) nanowires using potassium permanganate (KMnO4) and different inorganic acids (HCl, HNO3, and H2SO4) under reflux conditions. The morphology and nanostructure of the synthesized products are characterized by X-ray diffraction, Ar adsorption, and electron microscopy analysis, in order to elucidate the controlling effects of acid concentration and type as well as the formation mechanism of OMS-2 nanowires. The concentration of inorganic acid is a crucial factor controlling the phase of the synthesized products. OMS-2 nanowires are obtained with HCl at the concentration ≥0.96 mol/L or with HNO3 and H2SO4 at the concentrations ≥0.72 mol/L. Differently, the type of inorganic acid effectively determines the particle size of OMS-2 nanowires. When the acid is changed from HCl to HNO3 and H2SO4 in the reflux system, the average length of OMS-2 declines significantly by 60-70% (1104-442 and 339 nm), with minor decreased in the average width (43-39 and 34 nm). The formation of OMS-2 nanowires under reflux conditions with KMnO4 and inorganic acids involves a two-step process, i.e., the initial formation of layered manganese oxides, and subsequent transformation to OMS-2 via a dissolution-recrystallization process under acidic conditions. The proposed reflux route provides an alternative approach for synthesizing OMS-2 nanowires as well as other porous nano-crystalline OMS materials.

Enhancement of particle aggregation in the presence of organic matter during neutralization of acid drainage in a stream confluence and its effect on arsenic immobilization.

PubMed

Arce, Guillermo; Montecinos, Mauricio; Guerra, Paula; Escauriaza, Cristian; Coquery, Marina; Pastén, Pablo

2017-08-01

Acid drainage (AD) is an important environmental concern that impacts water quality. The formation of reactive Fe and Al oxyhydroxides during the neutralization of AD at river confluences is a natural attenuation process. Although it is known that organic matter (OM) can affect the aggregation of Fe and Al oxyhydroxides and the sorption of As onto their surfaces, the role of OM during the neutralization of AD at river confluences has not been studied. Field and experimental approaches were used to understand this role, using the Azufre River (pH 2) - Caracarani River (pH 8.6) confluence (northern Chile) as model system. Field measurements of organic carbon revealed a 10-15% loss of OM downstream the confluence, which was attributed to associations with Fe and Al oxyhydroxides that settle in the river bed. Laboratory mixtures of AD water with synthetic Caracarani waters under varying conditions of pH, concentration and type of OM revealed that OM promoted the aggregation of Fe oxyhydroxides without reducing As sorption, enhancing the removal of As at slightly acidic conditions (pH ∼4.5). At acidic conditions (pH ∼3), aggregation of OM - metal complexes at high OM concentrations could become the main removal mechanism. One type of OM promoted bimodal particle size distributions with larger mean sizes, possibly increasing the settling velocity of aggregates. This work contributes to a better understanding of the role of OM in AD affected basins, showing that the presence of OM during processes of neutralization of AD can enhance the removal of toxic elements. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Organic Matter Molecular Characteristics of Pyrogenic Solids and Their Aqueous Leachable Fractions

NASA Astrophysics Data System (ADS)

Wozniak, A. S.; Hatcher, P.; Mitra, S.; Bostick, K. W.; Zimmerman, A. R.

2016-02-01

Pyrogenic organic matter (Py-OM), or black carbon (BC), derives from the incomplete combustion of fossil fuels and biomass and is recognized for its impacts on soil chemistry, pollutant transport, climate, and regional and global carbon cycling. In fact, Py-OM is commonly applied to agricultural plots, in the form of "biochars," with the intention of enhancing agricultural production and the expectation of a carbon sequestration side benefit due to Py-OM's refractory and immobile nature. However, several studies of riverine, estuarine, and oceanic waters have detected tracers of dissolved Py-OM in appreciable quantities suggesting that it is more mobile in the environment than previously expected. The quantities and impacts of Py-OM released to aqueous systems are likely dependent on Py-OM molecular characteristics which in turn likely depend on initial combustion conditions and environmental processing. Yet, very little is known about the detailed molecular composition of these materials, let alone their relationships with combustion and environmental processing. Here, pyrophosphate extractable and water leachable components of a range of Py-OM materials (natural charcoals aged in the environment for variable lengths of time, oak and grass combusted over a range of temperatures) are examined by Fourier transform ion cyclotron resonance mass spectrometry. The molecular characteristics of the dissolved and pyrophosphate extractable Py-OM is then compared in the context of production conditions. Results of this study will greatly improve our understanding of Py-OM cycling between watersheds and the oceans.

A novel sputum transport solution eliminates cold chain and supports routine tuberculosis testing in Nepal.

PubMed

Maharjan, Bhagwan; Shrestha, Bhabana; Weirich, Alexandra; Stewart, Andrew; Kelly-Cirino, Cassandra D

2016-12-01

This preliminary study evaluated the transport reagent OMNIgene SPUTUM (OMS) in a real-world, resource-limited setting: a zonal hospital and national tuberculosis (TB) reference laboratory, Nepal. The objectives were to: (1) assess the performance of OMS for transporting sputum from peripheral sites without cold chain stabilization; and (2) compare with Nepal's standard of care (SOC) for Mycobacterium tuberculosis smear and culture diagnostics. Sixty sputa were manually split into a SOC sample (airline-couriered to the laboratory, conventional processing) and an OMS sample (OMS added at collection, no cold chain transport or processing). Smear microscopy and solid culture were performed. Transport was 0-8days. Forty-one samples (68%) were smear-positive using both methods. Of the OMS cultures, 37 (62%) were positive, 22 (36%) were negative, and one (2%) was contaminated. Corresponding SOC results were 32 (53%), 21 (35%), and seven (12%). OMS "rescued" six (i.e., missed using SOC) compared with one rescue using SOC. Of smear-positives, six SOC samples produced contaminated cultures whereas only one OMS sample was contaminated. OMS reduced culture contamination from 12% to 2%, and improved TB detection by 9%. The results suggest that OMS could perform well as a no cold chain, long-term transport solution for smear and culture testing. The findings provide a basis for larger feasibility studies. Copyright © 2016 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

Virulence and Immunomodulatory Roles of Bacterial Outer Membrane Vesicles

PubMed Central

Ellis, Terri N.; Kuehn, Meta J.

2010-01-01

Summary: Outer membrane (OM) vesicles are ubiquitously produced by Gram-negative bacteria during all stages of bacterial growth. OM vesicles are naturally secreted by both pathogenic and nonpathogenic bacteria. Strong experimental evidence exists to categorize OM vesicle production as a type of Gram-negative bacterial virulence factor. A growing body of data demonstrates an association of active virulence factors and toxins with vesicles, suggesting that they play a role in pathogenesis. One of the most popular and best-studied pathogenic functions for membrane vesicles is to serve as natural vehicles for the intercellular transport of virulence factors and other materials directly into host cells. The production of OM vesicles has been identified as an independent bacterial stress response pathway that is activated when bacteria encounter environmental stress, such as what might be experienced during the colonization of host tissues. Their detection in infected human tissues reinforces this theory. Various other virulence factors are also associated with OM vesicles, including adhesins and degradative enzymes. As a result, OM vesicles are heavily laden with pathogen-associated molecular patterns (PAMPs), virulence factors, and other OM components that can impact the course of infection by having toxigenic effects or by the activation of the innate immune response. However, infected hosts can also benefit from OM vesicle production by stimulating their ability to mount an effective defense. Vesicles display antigens and can elicit potent inflammatory and immune responses. In sum, OM vesicles are likely to play a significant role in the virulence of Gram-negative bacterial pathogens. PMID:20197500

Water speciation in sodium silicate glasses (quenched melts): A comprehensive NMR study

NASA Astrophysics Data System (ADS)

Xue, X.; Kanzaki, M.; Eguchi, J.

2012-12-01

Dissolution mechanism of water is an important factor governing how the dissolved water affects the physical and thermodynamic properties of silicate melts and glasses. Our previous studies have demonstrated that 1H MAS NMR in combination with 29Si-1H and 27Al-1H double-resonance NMR experiments is an effective approach for unambiguously differentiating and quantifying different water species in quenched silicate melts (glasses). Several contrasting dissolution mechanisms have been revealed depending on the melt composition: for relatively polymerized melts, the formation of SiOH/AlOH species (plus molecular H2O) and depolymerization of the network structure dominate; whereas for depolymerized Ca-Mg silicate melts, free OH (e.g. MgOH) become increasingly important (cf. [1]). The proportion of free OH species has been shown to decrease with both increasing melt polymerization (silica content) and decreasing field strength of the network modifying cations (from Mg to Ca). Our previous 1H and 29Si MAS NMR results for hydrous Na silicate glasses of limited compositions (Na2Si4O9 and Na2Si2O5) were consistent with negligible free OH (NaOH) species and depolymerizing effect of water dissolution [2]. On the other hand, there were also other studies that proposed the presence of significant NaOH species in hydrous glasses near the Na2Si2O5 composition. The purpose of this study is apply the approach of combined 1H MAS NMR and double-resonance (29Si-1H and 23Na-1H) NMR to gain unambiguous evidence for the OH speciation in Na silicate glasses (melts) as a function of composition. Hydrous Na silicate glasses containing mostly ≤ 1 wt% H2O for a range of Na/Si ratios from 0.33 to 1.33 have been synthesized by rapidly quenching melts either at 0.2 GPa using an internally heated gas pressure vessel or at 1 GPa using a piston cylinder high-pressure apparatus. NMR spectra have been acquired using a 9.4 T Varian Unity-Inova spectrometer. The 29Si and 1H chemical shifts are reported relative to TMS. The 1H MAS NMR spectra show broad peaks covering a chemical shift range of 1 to 17 ppm, with peak maxima near 4 and 15 ppm for more Si-rich compositions and near 12 ppm for less Si-rich compositions. The 1H-29Si-1H and 23Na-1H cross-polarization (CP) MAS NMR spectra for all the hydrous Na silicate glasses suggest negligible NaOH species, which, if present, should show enhanced relative intensity with 23Na-1H CP and the opposite with 1H-29Si-1H CP. All the observed 1H NMR intensities can be attributed to SiOH species of a range of hydrogen-bonding distances, plus a small amount of molecular H2O for higher water-content samples that contribute to intensities around 6 ppm. In conclusion, our combined 1H MAS NMR and double-resonance (1H-29Si-1H and 23Na-1H CP) MAS NMR study on Na silicate glasses of a range of Na/Si ratios has confirmed that water dissolves predominantly as SiOH and molecular H2O species in Na silicate melts (glasses), consistent with the trend predicted from studies on the Ca-Mg silicate system [1,2]. References:[1] Xue, X. Y.; Kanzaki, M. J. Am. Ceram. Soc. 2009, 92, 2803-2830. [2] Xue, X. Y.; Kanzaki, M. Geochim. Cosmochim. Acta 2004, 68, 5027-5057.

Top Operations and Maintenance (O&M) Efficiency Opportunities at DoD/Army Sites - A Guide for O&M/Energy Managers and Practitioners

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

Sullivan, Gregory P.; Dean, Jesse D.; Dixon, Douglas R.

2007-05-25

This report, sponsored the Army's Energy Engineering Analysis Program, provides the Operations and Maintenance (O&M) Energy manager and practitioner with useful information about the top O&M opportunities consistently found across the DoD/Army sector. The target is to help the DoD/Army sector develop a well-structured and organized O&M program.

O&M Best Practices - A Guide to Achieving Operational Efficiency (Release 2.0)

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

Sullivan, Gregory P.; Pugh, Ray; Melendez, Aldo P.

2004-07-31

This guide, sponsored by DOE's Federal Energy Management Program, highlights operations and maintenance (O&M) programs targeting energy efficiency that are estimated to save 5% to 20% on energy bills without a significant capital investment. The purpose of this guide is to provide the federal O&M energy manager and practitioner with useful information about O&M management, technologies, energy efficiency and cost-reduction approaches.

Outer-membrane translocation of bulky small molecules by passive diffusion

PubMed Central

van den Berg, Bert; Prathyusha Bhamidimarri, Satya; Dahyabhai Prajapati, Jigneshkumar; Kleinekathöfer, Ulrich; Winterhalter, Mathias

2015-01-01

The outer membrane (OM) of gram-negative bacteria forms a protective layer around the cell that serves as a permeability barrier to prevent unrestricted access of noxious substances. The permeability barrier of the OM results partly from the limited pore diameters of OM diffusion channels. As a consequence, there is an “OM size-exclusion limit,” and the uptake of bulky molecules with molecular masses of more than ∼600 Da is thought to be mediated by TonB-dependent, active transporters. Intriguingly, the OM protein CymA from Klebsiella oxytoca does not depend on TonB but nevertheless mediates efficient OM passage of cyclodextrins with diameters of up to ∼15 Å. Here we show, by using X-ray crystallography, molecular dynamics simulations, and single-channel electrophysiology, that CymA forms a monomeric 14-stranded β-barrel with a large pore that is occluded on the periplasmic side by the N-terminal 15 residues of the protein. Representing a previously unidentified paradigm in OM transport, CymA mediates the passive diffusion of bulky molecules via an elegant transport mechanism in which a mobile element formed by the N terminus acts as a ligand-expelled gate to preserve the permeability barrier of the OM. PMID:26015567

A Peptidomimetic Antibiotic Targets Outer Membrane Proteins and Disrupts Selectively the Outer Membrane in Escherichia coli*

PubMed Central

Urfer, Matthias; Bogdanovic, Jasmina; Lo Monte, Fabio; Moehle, Kerstin; Zerbe, Katja; Omasits, Ulrich; Ahrens, Christian H.; Pessi, Gabriella; Eberl, Leo; Robinson, John A.

2016-01-01

Increasing antibacterial resistance presents a major challenge in antibiotic discovery. One attractive target in Gram-negative bacteria is the unique asymmetric outer membrane (OM), which acts as a permeability barrier that protects the cell from external stresses, such as the presence of antibiotics. We describe a novel β-hairpin macrocyclic peptide JB-95 with potent antimicrobial activity against Escherichia coli. This peptide exhibits no cellular lytic activity, but electron microscopy and fluorescence studies reveal an ability to selectively disrupt the OM but not the inner membrane of E. coli. The selective targeting of the OM probably occurs through interactions of JB-95 with selected β-barrel OM proteins, including BamA and LptD as shown by photolabeling experiments. Membrane proteomic studies reveal rapid depletion of many β-barrel OM proteins from JB-95-treated E. coli, consistent with induction of a membrane stress response and/or direct inhibition of the Bam folding machine. The results suggest that lethal disruption of the OM by JB-95 occurs through a novel mechanism of action at key interaction sites within clusters of β-barrel proteins in the OM. These findings open new avenues for developing antibiotics that specifically target β-barrel proteins and the integrity of the Gram-negative OM. PMID:26627837

Quasi-interferometric scheme improved by fiber Bragg grating written on macrostructure defect in silica multimode optical fiber operating in a few-mode regime

NASA Astrophysics Data System (ADS)

Evtushenko, Alexander S.; Faskhutdinov, Lenar M.; Kafarova, Anastasia M.; Kuznetzov, Artem A.; Minaeva, Alina Yu.; Sevruk, Nikita L.; Nureev, Ilnur I.; Vasilets, Alexander A.; Andreev, Vladimir A.; Morozov, Oleg G.; Burdin, Vladimir A.; Bourdine, Anton V.

2017-04-01

This work presents results of experimental approbation of earlier on proposed modified fiber optic stress sensor based on a few-mode effects occurring during laser-excited optical signal propagation over silica multimode optical fiber (MMF). Modification is concerned with a passage to quasi-interferometric scheme realized by two multimode Y-couplers with equalized arm lengths improved by fiber Bragg grating (FBG) written on preliminary formed precision macrostructure defects in silica multimode graded-index optical fibers and special offset launching conditions providing laser-based excitation of higher-order modes. The "arms" of quasi-interferometer are two equalized lengths of MMF Cat. OM2 with great central dip of refractive index profile and strong pulse splitting due to high differential mode delay (DMD). We tested FBGs with Bragg wavelength both 1310 nm and 1550 nm written over tapers or up-tapers preliminary formed in short pieces of MMF Cat. OM2+/OM3 and further jointed to the end of one of the arms before output Y-coupler. Researches were focused on comparison analysis of pulse responses under changing of selected excited mode mixing and power diffusion processes due to stress distributed action to sensor fiber depending. Here we considered FBGs not only as particular wavelength reflector during spectral response measurement but also as local periodic microstructure defect which strongly effects on few-mode signal components mixing process also improved by combination with macro-defect like taper or up-taper that should provide response variation. Some results pulse response measurements produced for different scheme configuration and their comparison analysis are represented.

Electromagnetic response of a conductor with complex conductivity

NASA Astrophysics Data System (ADS)

Leylekian, L.; Ocio, M.; Hammann, J.

1993-02-01

The aim of this paper is to describe the electromagnetic response of a conductor with complex conductivity. We will show how the geometry of the measuring apparatus can modify the amplitude of this response. We will particularly emphasize the role that plays a complex conductivity, as we can find in granular superconductors, on the mesured magnetic susceptibility of the sample. Cet article a pour but de décrire la réponse électromagnétique d'un conducteur muni d'une conductivité complexe. Nous montrerons comment la géométrie du dispositif de mesure peut modifier l'amplitude de cette réponse. Nous insisterons particulièrement sur le rôle que joue une conductivité complexe, comme nous pouvons en trouver dans les supraconducteurs granulaires, sur la susceptibilité magnétique mesurée de l'échantillon.

An operations management system for the Space Station

NASA Astrophysics Data System (ADS)

Savage, Terry R.

A description is provided of an Operations Management System (OMS) for the planned NASA Space Station. The OMS would be distributed both in space and on the ground, and provide a transparent interface to the communications and data processing facilities of the Space Station Program. The allocation of OMS responsibilities has, in the most current Space Station design, been fragmented among the Communications and Tracking Subsystem (CTS), the Data Management System (DMS), and a redefined OMS. In this current view, OMS is less of a participant in the real-time processing, and more an overseer of the health and management of the Space Station operations.

Why Do Women Choose to Enter Academic Oral and Maxillofacial Surgery?

PubMed

Kolokythas, Antonia; Miloro, Michael

2016-05-01

To determine why women choose to enter an academic career in oral and maxillofacial surgery (OMS). An online questionnaire was developed and e-mailed to female OMS surgeons to assess the reasons women choose to pursue an academic career, the perceived positive and negative features of academia for women, and proposed measures to increase the percentage of women choosing to specialize in OMS and pursue an academic career. Thirty-one female OMS surgeons completed the questionnaire; 1 additional participant accessed the survey but did not respond to any of the questions. There were 25 full-time academics and 6 part-time academics (≥50% time commitment). Of the responders, 72% were married, and of these, 72% were married before entering academics. Forty-seven percent of the women had children, all during their academic tenure. Among the full-time academicians with children, only 2 (7.7%) reported moderate difficulty finding the time for childbirth and maternity leave, whereas 3 of the 5 part-time academics with children reported moderate or significant difficulty with childbirth and maternity leave. Factors associated with choosing and enjoying an academic career are involvement in resident-student teaching (78%), followed by colleague camaraderie and collaboration (65.6%), research potential (50%), time flexibility, and not having to deal with excessive "business" practice issues (33%). The main reason for considering leaving an academic OMS career and/or among the least enjoyable aspects of being in academics was the potential for a higher income in private practice (56%). Less significant reasons for considering leaving an academic OMS career were a more flexible work schedule in the private sector and less institutional red tape (37.5%), as well as independence/being in control and more family time (22%). Engaging residents and students by female OMS surgeons, better mentorship from academic OMS surgeons, and increasing the number of women serving in leadership positions in organized OMS were identified as the most important measures to increase female involvement in academic OMS. This study shows that among the major motivating factors for choosing an academic career are involvement in resident-student teaching and colleague camaraderie and collaboration. Additional important factors for making this career choice are the research potential in academia, time flexibility, and not having to deal with excessive business practice issues. The reasons that deter women from entering OMS as a specialty and choosing a full-time academic OMS career are not significantly related to childbirth and family life. The main reason for potentially considering leaving an academic OMS career and/or among the least enjoyable aspects of being in academics is the potential for a higher income in private practice. Other reasons for potentially considering leaving an academic OMS career indicated by this study are independence/being in control and more family time, as well as the lack of institutional red tape. It appears that engaging female residents and students by female OMS surgeons, better mentorship by (both male and female) academic OMS surgeons, and increasing the number of female surgeons who can serve as role models may be beneficial in increasing the number of female OMS surgeons interested in an academic career. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Organic metamorphism in the California petroleum basins; Chapter B, Insights from extractable bitumen and saturated hydrocarbons

USGS Publications Warehouse

Price, Leigh C.

2000-01-01

Seventy-five shales from the Los Angeles, Ventura, and Southern San Joaquin Valley Basins were extracted and analyzed. Samples were chosen on the basis of ROCK-EVAL analyses of a much larger sample base. The samples ranged in burial temperatures from 40 ? to 220 ? C, and contained hydrogen-poor to hydrogen-rich organic matter (OM), based on OM visual typing and a correlation of elemental kerogen hydrogen to carbon ratios with ROCK-EVAL hydrogen indices. By extractable bitumen measurements, rocks with hydrogen- poor OM in the Los Angeles Basin began mainstage hydrocarbon (HC) generation by 90 ? C. The HC concentrations maximized by 165 ? C, and beyond 165 ? C, HC and bitumen concentrations and ROCK-EVAL hydrogen indices all began decreasing to low values reached by 220 ? C, where HC generation was largely complete. Rocks with hydrogen-poor OM in the Southern San Joaquin Valley Basin commenced mainstage HC generation at 135 ? C and HC concentrations maximized by 180 ? C. Above 180 ? C, HC and bitumen concentrations and ROCK-EVAL hydrogen indices all decreased to low values reached by 214 ? C, again the process of HC generation being largely complete. In both cases, bell-shaped HC-generation curves were present versus depth (burial temperature). Mainstage HC generation had not yet begun in Ventura Basin rocks with hydrogen-poor OM by 140 ? C. The apparent lower temperature for initiation of mainstage generation in the Los Angeles Basin is attributed to very recent cooling in that basin from meteoric-water flow. Thus, HC generation there most probably occurred at higher burial temperatures. In contrast, mainstage HC generation, and all aspects of organic metamorphism, were strongly suppressed in rocks with hydrogen-rich OM at temperatures as high as 198 ? C. For example, shales from the Wilmington field (Los Angeles Basin) from 180 ? to 198 ? C retained ROCK-EVAL hydrogen indices of 550- 700 and had saturated-HC coefficients of only 4-15 mg/g organic carbon. The rocks with hydrogen-rich OM were subjected to the same burial conditions as the rocks with hydrogenpoor OM. We attribute this suppression of organic metamorphism in this study primarily to much stronger bonds in the hydrogen-rich OM compared to the bonds in hydrogen-poor OM. Trends in bitumen compositions (qualitative characteristics) versus burial temperature were also very different for rocks with hydrogen-poor OM compared to that in rocks with hydrogen- rich OM. This observation demonstrated that the two OM types also had significantly different reaction pathways, in addition to different reaction kinetics. Strong exploration implications arise from these observations. Above 40?C, but before mainstage HC generation, a lowtemperature (pre-mainstage) HC generation occurred in all rocks, and all OM types, studied. This low-temperature generation resulted in significant qualitative changes in the bitumen and HCS (hydrocarbons) from rocks of all OM types, especially in rocks with hydrogen-rich OM, from 40 ? to 70 ? C. This, and previous studies, document that very high carbon-normalized concentrations of indigenous bitumen and HCS occur in late Neogene immature rocks of any OM type in all southern California basins. This characteristic is attributed to the low-temperature generation occurring in both sulfur-poor and sulfur-rich kerogens, which originally had unusually high concentrations of weak (15-40 Kcal/mole) bonds. These observations and considerations have marked relevance to exploration regarding the possible formation of commercial oil deposits at immature ranks in these basins. Other significant geochemical observations also result from this study.

Oncologic profile of maxillary odontogenic myxoma: A rare case.

PubMed

Sarkar, Reena Radhikaprasad

2013-07-01

Odontogenic myxoma (OM) is an ectomesenchyme derived neoplasm, almost exclusively found in jaws. This article presents a maxillary OM with a brief review of the molecular and proteomic antecedents of OMs, capturing its histopathogenesis.

Intratemporal complications of otitis media.

PubMed

Maranhão, André Souza de Albuquerque; Andrade, José Santos Cruz de; Godofredo, Valéria Romero; Matos, Rafaella Caruso; Penido, Norma de Oliveira

2013-01-01

Otitis media (OM) is considered a potentially severe disease due to the risk of complications. To establish the annual incidence of intratemporal complications (ITC) resulting from OM and to prospectively assess patients for epidemiological and clinical factors. This prospective cohort study included patients admitted during one year at a university hospital diagnosed with intratemporal complications of OM. Patients were analyzed for age, gender, type of intratemporal complication, treatment, and clinical outcome. The overall incidence of complications and the specific incidence rates of each type of complication were determined. 1,816 patients were diagnosed with OM; 592 (33%) had chronic OM; 1224 (67%) had acute OM. Fifteen patients were diagnosed with OM ITC, adding up to an annual incidence of 0.8%. Nineteen diagnoses of ITC were made in 15 patients. Seven (36.8%) patients were diagnosed with labyrinthine fistula, five (26.3%) with mastoiditis, four (21.1%) with peripheral facial palsy, and three (15.8%) with labyrinthitis. The incidence of intratemporal complications remains significant when compared to the rates seen in developed countries. Chronic cholesteatomatous otitis media is the most frequent etiology of intratemporal complications. Labyrinthine fistula is the most common intratemporal complication.

Neuro-cognitive aspects of "OM" sound/syllable perception: A functional neuroimaging study.

PubMed

Kumar, Uttam; Guleria, Anupam; Khetrapal, Chunni Lal

2015-01-01

The sound "OM" is believed to bring mental peace and calm. The cortical activation associated with listening to sound "OM" in contrast to similar non-meaningful sound (TOM) and listening to a meaningful Hindi word (AAM) has been investigated using functional magnetic resonance imaging (MRI). The behaviour interleaved gradient technique was employed in order to avoid interference of scanner noise. The results reveal that listening to "OM" sound in contrast to the meaningful Hindi word condition activates areas of bilateral cerebellum, left middle frontal gyrus (dorsolateral middle frontal/BA 9), right precuneus (BA 5) and right supramarginal gyrus (SMG). Listening to "OM" sound in contrast to "non-meaningful" sound condition leads to cortical activation in bilateral middle frontal (BA9), right middle temporal (BA37), right angular gyrus (BA 40), right SMG and right superior middle frontal gyrus (BA 8). The conjunction analysis reveals that the common neural regions activated in listening to "OM" sound during both conditions are middle frontal (left dorsolateral middle frontal cortex) and right SMG. The results correspond to the fact that listening to "OM" sound recruits neural systems implicated in emotional empathy.

A comparison of the endotoxin biosynthesis and protein oxidation pathways in the biogenesis of the outer membrane of Escherichia coli and Neisseria meningitidis

PubMed Central

Piek, Susannah; Kahler, Charlene M.

2012-01-01

The Gram-negative bacterial cell envelope consists of an inner membrane (IM) that surrounds the cytoplasm and an asymmetrical outer-membrane (OM) that forms a protective barrier to the external environment. The OM consists of lipopolysaccahride (LPS), phospholipids, outer membrane proteins (OMPs), and lipoproteins. Oxidative protein folding mediated by periplasmic oxidoreductases is required for the biogenesis of the protein components, mainly constituents of virulence determinants such as pili, flagella, and toxins, of the Gram-negative OM. Recently, periplasmic oxidoreductases have been implicated in LPS biogenesis of Escherichia coli and Neisseria meningitidis. Differences in OM biogenesis, in particular the transport pathways for endotoxin to the OM, the composition and role of the protein oxidation, and isomerization pathways and the regulatory networks that control them have been found in these two Gram-negative species suggesting that although form and function of the OM is conserved, the pathways required for the biosynthesis of the OM and the regulatory circuits that control them have evolved to suit the lifestyle of each organism. PMID:23267440

Solution conformation of a neuronal nicotinic acetylcholine receptor antagonist {alpha}-conotoxin OmIA that discriminates {alpha}3 vs. {alpha}6 nAChR subtypes

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

Chi, Seung-Wook; Kim, Do-Hyoung; Olivera, Baldomero M.

2006-06-23

{alpha}-Conotoxin OmIA from Conus omaria is the only {alpha}-conotoxin that shows a {approx}20-fold higher affinity to the {alpha}3{beta}2 over the {alpha}6{beta}2 subtype of nicotinic acetylcholine receptor. We have determined a three-dimensional structure of {alpha}-conotoxin OmIA by nuclear magnetic resonance spectroscopy. {alpha}-Conotoxin OmIA has an '{omega}-shaped' overall topology with His{sup 5}-Asn{sup 12} forming an {alpha}-helix. Structural features of {alpha}-conotoxin OmIA responsible for its selectivity are suggested by comparing its surface characteristics with other functionally related {alpha}4/7 subfamily conotoxins. Reduced size of the hydrophilic area in {alpha}-conotoxin OmIA seems to be associated with the reduced affinity towards the {alpha}6{beta}2 nAChR subtype.

Submicron structures provide preferential spots for carbon and nitrogen sequestration in soils

PubMed Central

Vogel, Cordula; Mueller, Carsten W.; Höschen, Carmen; Buegger, Franz; Heister, Katja; Schulz, Stefanie; Schloter, Michael; Kögel-Knabner, Ingrid

2014-01-01

The sequestration of carbon and nitrogen by clay-sized particles in soils is well established, and clay content or mineral surface area has been used to estimate the sequestration potential of soils. Here, via incubation of a sieved (<2 mm) topsoil with labelled litter, we find that only some of the clay-sized surfaces bind organic matter (OM). Surprisingly, <19% of the visible mineral areas show an OM attachment. OM is preferentially associated with organo-mineral clusters with rough surfaces. By combining nano-scale secondary ion mass spectrometry and isotopic tracing, we distinguish between new labelled and pre-existing OM and show that new OM is preferentially attached to already present organo-mineral clusters. These results, which provide evidence that only a limited proportion of the clay-sized surfaces contribute to OM sequestration, revolutionize our view of carbon sequestration in soils and the widely used carbon saturation estimates. PMID:24399306

Redox Effects on Organic Matter Storage in Coastal Sediments During the Holocene: A Biomarker/Proxy Perspective

NASA Astrophysics Data System (ADS)

Bianchi, Thomas S.; Schreiner, Kathryn M.; Smith, Richard W.; Burdige, David J.; Woodard, Stella; Conley, Daniel J.

2016-06-01

Coastal margins play a significant role in the burial of organic matter (OM) on Earth. These margins vary considerably with respect to their efficiency in OM burial and to the amounts and periodicity of their OM delivery, depending in large part on whether they are passive or active margins. In the context of global warming, these coastal regions are expected to experience higher water temperatures, changes in riverine inputs of OM, and sea level rise. Low-oxygen conditions continue to expand around the globe in estuarine regions (i.e., hypoxic zones) and shelf regions (i.e., oxygen minimum zones), which will impact the amounts and sources of OM stored in these regions. In this review, we explore how these changes are impacting the storage of OM and the preservation of sedimentary biomarkers, used as proxies to reconstruct environmental change, in coastal margins.

Experimental evidence for an effect of early-diagenetic interaction between labile and refractory marine sedimentary organic matter on nitrogen dynamics

NASA Astrophysics Data System (ADS)

Turnewitsch, Robert; Domeyer, Bettina; Graf, Gerhard

2007-05-01

In most natural sedimentary systems labile and refractory organic material (OM) occur concomitantly. Little, however, is known on how different kinds of OM interact and how such interactions affect early diagenesis in sediments. In a simple sediment experiment, we investigated how interactions of OM substrates of different degradability affect benthic nitrogen (N) dynamics. Temporal evolution of a set of selected biogeochemical parameters was monitored in sandy sediment over 116 days in three experimental set-ups spiked with labile OM (tissue of Mytilus edulis), refractory OM (mostly aged Zostera marina and macroalgae), and a 1:1 mixture of labile and refractory OM. The initial amounts of particulate organic carbon (POC) were identical in the three set-ups. To check for non-linear interactions between labile and refractory OM, the evolution of the mixture system was compared with the evolution of the simple sum of the labile and refractory systems, divided by two. The sum system is the experimental control where labile and refractory OM are virtually combined but not allowed to interact. During the first 30 days there was evidence for net dissolved-inorganic-nitrogen (DIN) production followed by net DIN consumption. (Here 'DIN' is the sum of ammonium, nitrite and nitrate.) After ˜ 30 days a quasi steady state was reached. Non-linear interactions between the two types of OM were reflected by three main differences between the early-diagenetic evolutions of nitrogen dynamics of the mixture and sum (control) systems: (1) In the mixture system the phases of net DIN production and consumption commenced more rapidly and were more intense. (2) The mixture system was shifted towards a more oxidised state of DIN products [as indicated by increased (nitrite + nitrate)/(ammonium) ratios]. (3) There was some evidence that more OM, POC and particulate nitrogen were preserved in the mixture system. That is, in the mixture system more particulate OM was preserved while a higher proportion of the decomposed particulate N was converted into inorganic N. It can be concluded that during the first days and weeks of early diagenesis the magnitude and composition of the flux of decompositional dissolved N-compounds from sediments into the overlying water was influenced by non-linear interactions of OM substrates of different degradability. Given these experimental results it is likely that the relative spatial distributions of OM of differing degradability in sediments control the magnitude and composition of the return flux of dissolved N-bearing compounds from sediments into the overlying water column.

Wood source and pyrolysis temperature interact to control PyOM degradation rates

NASA Astrophysics Data System (ADS)

Bird, J. A.; Hatton, P. J.; Filley, T. R.; Chatterjee, S.; Auclerc, A.; Gormley, M.; Dastmalchi, K.; Stark, R. E.; Nadelhoffer, K. J.

2015-12-01

Surprisingly little is known about how shifts in tree species composition and increased forest fire frequency and intensity will affect one of the most stable pools of soil organic matter, i.e. the pyrogenic organic matter (PyOM or char). In a previous study, we showed that wood source and pyrolysis temperature interact to control PyOM structure and potential reactivity for two tree species common in high-latitude forests, jack pine (JP) and red maple (RM). Here, we investigate whether these differences affect PyOM turnover by examining the fates of 13C/15N-enriched JP wood and PyOM pyrolyzed at 300 (JP300) and 450 °C (JP450) and RM pyrolyzed at 450 °C (RM450). The substrates were applied 1-3 cm below the O/A interface of a well-drained Spodosol in a long-term forest fire study located at the University of Michigan Biological Station (Pellston, MI, USA). 13C-CO2effluxes from the first 996 days of decay showed a significant wood source by pyrolysis temperature interaction on PyOM field mineralisation rates, with RM450 mineralising twice faster than JP450 during the first 90 days. Increasing pyrolysis temperature substantially decreased field mineralization rates during the first 996 days, with mineralisation rates 24 and 80 times slower for JP300 and JP450 compared with JP wood. After 1 year, (i) bacterial groups were large sinks for PyOM-derived C as pyrolysis temperature increased and as substrate use efficiency decreased; (ii) potential phenol oxidase and net peroxidase activities were unaffected by the PyOM addition, although net peroxidase activities measured tended to lesser for soils amended with JP450 and RM450; and (iii) Collembola detritivores appeared less likely to be found for soils amended with JP450 and RM450. PyOM-derived C and N recoveries did not differ after 1 year; we will present 3-y recovery data. Our results suggest that the composition of angiosperms (e.g. RM) and gymnosperms (e.g. JP) in high-latitude forests is an underappreciated but essential determinant of soil PyOM stocks and reactivity, with angiosperms yielding more degradable PyOM. Considering the wood source by pyrolysis temperature interaction on PyOM will help providing more comprehensive large-scale assessments of PyOM stocks and reactivity potentials under current and future climate conditions.

Comparison of isthmus detection methods in the apical third of mesial roots of maxillary and mandibular first molars: macroscopic observation versus operating microscope.

PubMed

Kontakiotis, Evangelos G; Palamidakis, Fotios D; Farmakis, Eleftherios-Terry R; Tzanetakis, Giorgos N

2010-01-01

The aims of this study were to assess the presence and the frequency of isthmuses in the mesial roots of the maxillary and mandibular first molars (at two resection levels from the apex), and to compare the findings obtained by macroscopic observation (MO) and operating microscope (OM). Forty maxillary and 40 mandibular mesial roots were observed at 3 and 5 mm from the apex initially macroscopically and then with the use of an OM. The presence of an isthmus and the number of root canals detected were recorded. Data were analyzed statistically by Fisher's exact test for isthmus evaluation and Wilcoxon signed rank-test for number of root canals at a confidence interval of 95%. Comparison between MO and OM regarding the number of roots with isthmuses provided the following results: Mandibular group: At 3 mm level: MO 19 ?s. OM 27; at 5 mm level: MO 31 ?s. OM 32. Maxillary group: At 3 mm level: MO 9 ?s. OM 14; at 5 mm level: MO 19 ?s. OM 21. Significant differences (p<0.05) were found concerning the accuracy of the isthmus detection methods at both resection levels (3 and 5 mm) and both types of roots, as well as for the number of the canals inspected under the OM between the two resection levels of the mesial roots of the maxillary first molars. Under the tested conditions, OM increased the diagnostic accuracy of isthmus detection at both resection levels and root types.

Polar and non-polar organic aerosols from large-scale agricultural-waste burning emissions in Northern India: Implications to organic mass-to-organic carbon ratio.

PubMed

Rajput, Prashant; Sarin, M M

2014-05-01

This study focuses on characteristics of organic aerosols (polar and non-polar) and total organic mass-to-organic carbon ratio (OM/OC) from post-harvest agricultural-waste (paddy- and wheat-residue) burning emissions in Northern India. Aerosol samples from an upwind location (Patiala: 30.2°N, 76.3°E) in the Indo-Gangetic Plain were analyzed for non-polar and polar fractions of organic carbon (OC1 and OC2) and their respective mass (OM1 and OM2). On average, polar organic aerosols (OM2) contribute nearly 85% of the total organic mass (OM) from the paddy- and wheat-residue burning emissions. The water-soluble-OC (WSOC) to OC2 ratio, within the analytical uncertainty, is close to 1 from both paddy- and wheat-residue burning emissions. However, temporal variability and relatively low WSOC/OC2 ratio (Av: 0.67±0.06) is attributed to high moisture content and poor combustion efficiency during paddy-residue burning, indicating significant contribution (∼30%) of aromatic carbon to OC2. The OM/OC ratio for non-polar (OM1/OC1∼1.2) and polar organic aerosols (OM2/OC2∼2.2), hitherto unknown for open agricultural-waste burning emissions, is documented in this study. The total OM/OC ratio is nearly identical, 1.9±0.2 and 1.8±0.2, from paddy- and wheat-residue burning emissions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Physiological characterization of ocular melanosis-affected canine melanocytes.

PubMed

Dawson-Baglien, Ethan M; Noland, Erica L; Sledge, Dodd G; Kiupel, Matti; Petersen-Jones, Simon M

2018-04-27

Cairn terriers with ocular melanosis (OM) accumulate large, heavily pigmented melanocytes in the anterior uvea. Darkly pigmented plaques develop within the sclera, leading us to hypothesize that OM uveal melanocytes may have an abnormal migratory capacity. Globes from OM-affected Cairn terriers and unaffected control eyes enucleated for reasons unrelated to this study were used for immunohistochemistry and to culture melanocytes for in vitro cell behavior assays. The scleral plaques of six dogs were immunolabeled for HMB-45, MelanA, PNL2, CD18, CD204, and Iba-1 and compared with the pigment cells accumulated within the irides. Cultured uveal melanocytes from OM-affected and control dogs were compared using conventional assays measuring cell proliferation, invasion capability, and melanin production. Melanocytes isolated from OM eyes had significantly elevated levels of per-cell melanin content and production compared to controls. The majority of pigmented cells in the scleral plaques were HMB45 positive indicating a melanocytic origin. Many were also CD18 positive. No differences were observed between cultured melanocytes from OM-affected and control uvea for standard in vitro proliferation or invasion assays. Pigmented cells which accumulate in the sclera of OM-affected Cairn terriers are predominantly melanocytes; however, in vitro assays of uveal melanocytes did not reveal differences in migratory behavior between OM and control cells. Migratory behavior of OM-melanocytes may be environment-dependent. We suggest that RNA sequencing and differential expression analysis would be a useful next step in understanding this disease. © 2018 American College of Veterinary Ophthalmologists.

Microstructure and corrosion behavior of coated AZ91 alloy by microarc oxidation for biomedical application

NASA Astrophysics Data System (ADS)

Wang, Y. M.; Wang, F. H.; Xu, M. J.; Zhao, B.; Guo, L. X.; Ouyang, J. H.

2009-08-01

Magnesium and its alloy currently are considered as the potential biodegradable implant materials, while the accelerated corrosion rate in intro environment leads to implant failure by losing the mechanical integrity before complete restoration. Dense oxide coatings formed in alkaline silicate electrolyte with and without titania sol addition were fabricated on magnesium alloy using microarc oxidation process. The microstructure, composition and degradation behavior in simulated body fluid (SBF) of the coated specimens were evaluated. It reveals that a small amount of TiO 2 is introduced into the as-deposited coating mainly composed of MgO and Mg 2SiO 4 by the addition of titania sol into based alkaline silicate electrolytic bath. With increasing concentration of titania sol from 0 to 10 vol.%, the coating thickness decreases from 22 to 18 μm. Electrochemical tests show that the Ecorr of Mg substrate positively shifted about 300˜500 mV and icorr lowers more than 100 times after microarc oxidation. However, the TiO 2 modified coatings formed in electrolyte containing 5 and 10 vol.% titania sol indicate an increasing worse corrosion resistance compared with that of the unmodified coating, which is possibly attributed to the increasing amorphous components caused by TiO 2 involvement. The long term immersing test in SBF is consistent with the electrochemical test, with the coated Mg alloy obviously slowing down the biodegradation rate, meanwhile accompanied by the increasing damage trends in the coatings modified by 5 and 10 vol.% titania sol.

Modifying Si-based consolidants through the addition of colloidal nano-particles

NASA Astrophysics Data System (ADS)

Ksinopoulou, E.; Bakolas, A.; Moropoulou, A.

2016-04-01

The modification of silicon-based stone consolidants has been the subject of many scientific studies aiming to overcome the commonly reported drawbacks of these materials, such as the tendency to shrink and crack during drying. The addition of nano-particle dispersions into silica matrix has been found to enhance their effectiveness in several ways. Objective of the current research was to study the preparation of particle-modified consolidants (PMC), consisting of an ethyl silicate matrix (TEOS) loaded with colloidal silica (SiO2) nano-particles and oxide titania (TiO2) particles. The effect of the polyacrylic acid on the dispersion stability was also investigated, by varying its concentration into PMC samples. The prepared materials were allowed to dry in two different relative humidity environments and then evaluated based on their stability in the sol phase, the aggregation sizes, determined through dynamic light scattering, the % solids content and their morphological characteristics, observed via scanning electron microscopy (SEM-EDAX). Mercury intrusion porosimetry was also applied to investigate the microstructural characteristics and differences between the prepared consolidants. Significant role in the final form of the material is played by both the initial molar ratios in the mixtures, as well as the conditions where the drying and aging takes place. Based on the results, the three-component PMCs appear to be promising in stone consolidation, as they show a reduction in cracking and shrinkage during drying and a more porous network, compared with the siliceous material, or the two-component TEOS-SiO2 formulation.

Omeprazole induces heme oxygenase-1 in fetal human pulmonary microvascular endothelial cells via hydrogen peroxide-independent Nrf2 signaling pathway

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

Patel, Ananddeep; Zhang, Shaojie; Shrestha, Amrit

Omeprazole (OM) is an aryl hydrocarbon receptor (AhR) agonist and a proton pump inhibitor that is used to treat humans with gastric acid related disorders. Recently, we showed that OM induces NAD (P) H quinone oxidoreductase-1 (NQO1) via nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent mechanism. Heme oxygenase-1 (HO-1) is another cytoprotective and antioxidant enzyme that is regulated by Nrf2. Whether OM induces HO-1 in fetal human pulmonary microvascular endothelial cells (HPMEC) is unknown. Therefore, we tested the hypothesis that OM will induce HO-1 expression via Nrf2 in HPMEC. OM induced HO-1 mRNA and protein expression in a dose-dependent manner.more » siRNA-mediated knockdown of AhR failed to abrogate, whereas knockdown of Nrf2 abrogated HO-1 induction by OM. To identify the underlying molecular mechanisms, we determined the effects of OM on cellular hydrogen peroxide (H{sub 2}O{sub 2}) levels since oxidative stress mediated by the latter is known to activate Nrf2. Interestingly, the concentration at which OM induced HO-1 also increased H{sub 2}O{sub 2} levels. Furthermore, H{sub 2}O{sub 2} independently augmented HO-1 expression. Although N-acetyl cysteine (NAC) significantly decreased H{sub 2}O{sub 2} levels in OM-treated cells, we observed that OM further increased HO-1 mRNA and protein expression in NAC-pretreated compared to vehicle-pretreated cells, suggesting that OM induces HO-1 via H{sub 2}O{sub 2}-independent mechanisms. In conclusion, we provide evidence that OM transcriptionally induces HO-1 via AhR - and H{sub 2}O{sub 2} - independent, but Nrf2 - dependent mechanisms. These results have important implications for human disorders where Nrf2 and HO-1 play a beneficial role. - Highlights: • Omeprazole induces HO-1 in human fetal lung cells. • AhR deficiency fails to abrogate omeprazole-mediated induction of HO-1. • Nrf2 knockdown abrogates omeprazole-mediated HO-1 induction in human lung cells. • Hydrogen peroxide depletion augments omeprazole-mediated induction of HO-1.« less

Novel synthesis of manganese and vanadium mixed oxide (V{sub 2}O{sub 5}/OMS-2) as an efficient and selective catalyst for the oxidation of alcohols in liquid phase

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

Mahdavi, Vahid, E-mail: v-mahdavi@araku.ac.ir; Soleimani, Shima

2014-03-01

Graphical abstract: Oxidation of various alcohols is studied in the liquid phase over new composite mixed oxide (V{sub 2}O{sub 5}/OMS-2) catalyst using tert-butyl hydroperoxide (TBHP). The activity of V{sub 2}O{sub 5}/OMS-2 samples was considerably increased with respect to OMS-2 catalyst and these samples are found to be suitable for the selective oxidation of alcohols. - Highlights: • V{sub 2}O{sub 5}/K-OMS-2 with different V/Mn molar ratios prepared by the impregnation method. • Oxidation of alcohols was studied in the liquid phase over V{sub 2}O{sub 5}/K-OMS-2 catalyst. • V{sub 2}O{sub 5}/K-OMS-2 catalyst had excellent activity for alcohol oxidation. • Benzyl alcohol oxidationmore » using excess TBHP followed a pseudo-first order kinetic. • The selected catalyst was reused without significant loss of activity. - Abstract: This work reports the synthesis and characterization of mixed oxide vanadium–manganese V{sub 2}O{sub 5}/K-OMS-2 at various V/Mn molar ratios and prepared by the impregnation method. Characterization of these new composite materials was made by elemental analysis, BET, XRD, FT-IR, SEM and TEM techniques. Results of these analyses showed that vanadium impregnated samples contained mixed phases of cryptomelane and crystalline V{sub 2}O{sub 5} species. Oxidation of various alcohols was studied in the liquid phase over the V{sub 2}O{sub 5}/K-OMS-2 catalyst using tert-butyl hydroperoxide (TBHP) and H{sub 2}O{sub 2} as the oxidant. Activity of the V{sub 2}O{sub 5}/K-OMS-2 samples was increased considerably with respect to K-OMS-2 catalyst due to the interaction of manganese oxide and V{sub 2}O{sub 5}. The kinetic of benzyl alcohol oxidation using excess TBHP over V{sub 2}O{sub 5}/K-OMS-2 catalyst was investigated at different temperatures and a pseudo-first order reaction was determined with respect to benzyl alcohol. The effects of reaction time, oxidant/alcohol molar ratio, reaction temperature, solvents, catalyst recycling potential and leaching were investigated.« less

Mucin Production and Mucous Cell Metaplasia in Otitis Media

PubMed Central

Lin, Jizhen; Caye-Thomasen, Per; Tono, Tetsuya; Zhang, Quan-An; Nakamura, Yoshihisa; Feng, Ling; Huang, Jianmin; Ye, Shengnan; Hu, Xiaohua; Kerschner, Joseph E.

2012-01-01

Otitis media (OM) with mucoid effusion, characterized by mucous cell metaplasia/hyperplasia in the middle ear cleft and thick fluid accumulation in the middle ear cavity, is a subtype of OM which frequently leads to chronic OM in young children. Multiple factors are involved in the developmental process of OM with mucoid effusion, especially disorders of mucin production resulting from middle ear bacterial infection and Eustachian tube dysfunction. In this review, we will focus on several aspects of this disorder by analyzing the cellular and molecular events such as mucin production and mucous cell differentiation in the middle ear mucosa with OM. In addition, infectious agents, mucin production triggers, and relevant signaling pathways will be discussed. PMID:22685463

A Guide for Using Geochemical Methods in Dredged Material, Sediment Tracking, and Sediment Budget Studies

DTIC Science & Technology

2017-06-26

size on ratios of OM. Specifically, there are two basic forms of OM. Particulate OM, such woody and vegetative debris, soot, and charcoal, exists as...discrete particles that influence a bulk samples carbon content. Conversely, a second form of OM occurs as a film-like substance that is strongly...nitrogen. Carbon occurs in a wide variety of forms associated with sediments from organic compounds to inorganic carbonates. Carbon has two stable

Quantification of Organic Porosity and Water Accessibility in Marcellus Shale Using Neutron Scattering

DOE PAGES

Gu, Xin; Mildner, David F. R.; Cole, David R.; ...

2016-04-28

Pores within organic matter (OM) are a significant contributor to the total pore system in gas shales. These pores contribute most of the storage capacity in gas shales. Here we present a novel approach to characterize the OM pore structure (including the porosity, specific surface area, pore size distribution, and water accessibility) in Marcellus shale. By using ultrasmall and small-angle neutron scattering, and by exploiting the contrast matching of the shale matrix with suitable mixtures of deuterated and protonated water, both total and water-accessible porosity were measured on centimeter-sized samples from two boreholes from the nanometer to micrometer scale withmore » good statistical coverage. Samples were also measured after combustion at 450 °C. Analysis of scattering data from these procedures allowed quantification of OM porosity and water accessibility. OM hosts 24–47% of the total porosity for both organic-rich and -poor samples. This porosity occupies as much as 29% of the OM volume. In contrast to the current paradigm in the literature that OM porosity is organophilic and therefore not likely to contain water, our results demonstrate that OM pores with widths >20 nm exhibit the characteristics of water accessibility. In conclusion, our approach reveals the complex structure and wetting behavior of the OM porosity at scales that are hard to interrogate using other techniques.« less

Quantification of Organic Porosity and Water Accessibility in Marcellus Shale Using Neutron Scattering

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

Gu, Xin; Mildner, David F. R.; Cole, David R.

Pores within organic matter (OM) are a significant contributor to the total pore system in gas shales. These pores contribute most of the storage capacity in gas shales. Here we present a novel approach to characterize the OM pore structure (including the porosity, specific surface area, pore size distribution, and water accessibility) in Marcellus shale. By using ultrasmall and small-angle neutron scattering, and by exploiting the contrast matching of the shale matrix with suitable mixtures of deuterated and protonated water, both total and water-accessible porosity were measured on centimeter-sized samples from two boreholes from the nanometer to micrometer scale withmore » good statistical coverage. Samples were also measured after combustion at 450 °C. Analysis of scattering data from these procedures allowed quantification of OM porosity and water accessibility. OM hosts 24–47% of the total porosity for both organic-rich and -poor samples. This porosity occupies as much as 29% of the OM volume. In contrast to the current paradigm in the literature that OM porosity is organophilic and therefore not likely to contain water, our results demonstrate that OM pores with widths >20 nm exhibit the characteristics of water accessibility. In conclusion, our approach reveals the complex structure and wetting behavior of the OM porosity at scales that are hard to interrogate using other techniques.« less

Global-change effects on early-stage decomposition processes in tidal wetlands - implications from a global survey using standardized litter

NASA Astrophysics Data System (ADS)

Mueller, Peter; Schile-Beers, Lisa M.; Mozdzer, Thomas J.; Chmura, Gail L.; Dinter, Thomas; Kuzyakov, Yakov; de Groot, Alma V.; Esselink, Peter; Smit, Christian; D'Alpaos, Andrea; Ibáñez, Carles; Lazarus, Magdalena; Neumeier, Urs; Johnson, Beverly J.; Baldwin, Andrew H.; Yarwood, Stephanie A.; Montemayor, Diana I.; Yang, Zaichao; Wu, Jihua; Jensen, Kai; Nolte, Stefanie

2018-05-01

Tidal wetlands, such as tidal marshes and mangroves, are hotspots for carbon sequestration. The preservation of organic matter (OM) is a critical process by which tidal wetlands exert influence over the global carbon cycle and at the same time gain elevation to keep pace with sea-level rise (SLR). The present study assessed the effects of temperature and relative sea level on the decomposition rate and stabilization of OM in tidal wetlands worldwide, utilizing commercially available standardized litter. While effects on decomposition rate per se were minor, we show strong negative effects of temperature and relative sea level on stabilization, as based on the fraction of labile, rapidly hydrolyzable OM that becomes stabilized during deployment. Across study sites, OM stabilization was 29 % lower in low, more frequently flooded vs. high, less frequently flooded zones. Stabilization declined by ˜ 75 % over the studied temperature gradient from 10.9 to 28.5 °C. Additionally, data from the Plum Island long-term ecological research site in Massachusetts, USA, show a pronounced reduction in OM stabilization by > 70 % in response to simulated coastal eutrophication, confirming the potentially high sensitivity of OM stabilization to global change. We therefore provide evidence that rising temperature, accelerated SLR, and coastal eutrophication may decrease the future capacity of tidal wetlands to sequester carbon by affecting the initial transformations of recent OM inputs to soil OM.

Omeprazole induces NAD(P)H quinone oxidoreductase 1 via aryl hydrocarbon receptor-independent mechanisms: Role of the transcription factor nuclear factor erythroid 2–related factor 2

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

Zhang, Shaojie; Patel, Ananddeep; Moorthy, Bhagavatula

2015-11-13

Activation of the aryl hydrocarbon receptor (AhR) transcriptionally induces phase I (cytochrome P450 (CYP) 1A1) and phase II (NAD(P)H quinone oxidoreductase 1 (NQO1) detoxifying enzymes. The effects of the classical and nonclassical AhR ligands on phase I and II enzymes are well studied in human hepatocytes. Additionally, we observed that the proton pump inhibitor, omeprazole (OM), transcriptionally induces CYP1A1 in the human adenocarcinoma cell line, H441 cells via AhR. Whether OM activates AhR and induces the phase II enzyme, NAD(P)H quinone oxidoreductase 1 (NQO1), in fetal primary human pulmonary microvascular endothelial cells (HPMEC) is unknown. Therefore, we tested the hypothesis thatmore » OM will induce NQO1 in HPMEC via the AhR. The concentrations of OM used in our experiments did not result in cytotoxicity. OM activated AhR as evident by increased CYP1A1 mRNA expression. However, contrary to our hypothesis, OM increased NQO1 mRNA and protein via an AhR-independent mechanism as AhR knockdown failed to abrogate OM-mediated increase in NQO1 expression. Interestingly, OM activated Nrf2 as evident by increased phosphoNrf2 (S40) expression in OM-treated compared to vehicle-treated cells. Furthermore, Nrf2 knockdown abrogated OM-mediated increase in NQO1 expression. In conclusion, we provide evidence that OM induces NQO1 via AhR-independent, but Nrf2-dependent mechanisms. - Highlights: • We investigated whether omeprazole induces NQO1 in human fetal lung cells. • Omeprazole induces the phase II enzyme, NQO1, in human fetal lung cells. • AhR deficiency fails to abrogate omeprazole-mediated induction of NQO1. • Omeprazole increases phosphoNrf2 (S40) protein expression in human fetal lung cells. • Nrf2 knockdown abrogates the induction of NQO1 by omeprazole in human lung cells.« less

Optimising technology to measure functional vision, mobility and service outcomes for people with low vision or blindness: protocol for a prospective cohort study in Australia and Malaysia

PubMed Central

Deverell, Lil; Meyer, Denny; Lau, Bee Theng; Al Mahmud, Abdullah; Sukunesan, Suku; Bhowmik, Jahar; Chai, Almon; McCarthy, Chris; Zheng, Pan; Pipingas, Andrew; Islam, Fakir M Amirul

2017-01-01

Introduction Orientation and mobility (O&M) specialists assess the functional vision and O&M skills of people with mobility problems, usually relating to low vision or blindness. There are numerous O&M assessment checklists but no measures that reduce qualitative assessment data to a single comparable score suitable for assessing any O&M client, of any age or ability, in any location. Functional measures are needed internationally to align O&M assessment practices, guide referrals, profile O&M clients, plan appropriate services and evaluate outcomes from O&M programmes (eg, long cane training), assistive technology (eg, hazard sensors) and medical interventions (eg, retinal implants). This study aims to validate two new measures of functional performance vision-related outcomes in orientation and mobility (VROOM) and orientation and mobility outcomes (OMO) in the context of ordinary O&M assessments in Australia, with cultural comparisons in Malaysia, also developing phone apps and online training to streamline professional assessment practices. Methods and analysis This multiphase observational study will employ embedded mixed methods with a qualitative/quantitative priority: corating functional vision and O&M during social inquiry. Australian O&M agencies (n=15) provide the sampling frame. O&M specialists will use quota sampling to generate cross-sectional assessment data (n=400) before investigating selected cohorts in outcome studies. Cultural relevance of the VROOM and OMO tools will be investigated in Malaysia, where the tools will inform the design of assistive devices and evaluate prototypes. Exploratory and confirmatory factor analysis, Rasch modelling, cluster analysis and analysis of variance will be undertaken along with descriptive analysis of measurement data. Qualitative findings will be used to interpret VROOM and OMO scores, filter statistically significant results, warrant their generalisability and identify additional relevant constructs that could also be measured. Ethics and dissemination Ethical approval has been granted by the Human Research Ethics Committee at Swinburne University (SHR Project 2016/316). Dissemination of results will be via agency reports, journal articles and conference presentations. PMID:29273657

Organic matter composition at intact biopore and crack surfaces of Luvisol B-horizons analyzed by FTIR spectroscopy and Pyrolysis-Field Ionization Mass Spectrometry

NASA Astrophysics Data System (ADS)

Leue, Martin; Eckhardt, Kai-Uwe; Ellerbrock, Ruth H.; Gerke, Horst H.; Leinweber, Peter

2015-04-01

In the B-horizons of Luvisols, surfaces of biopores and aggregates can be enriched in clay and organic matter (OM), relative to the bulk of the soil matrix. The OM composition of these coatings determines their bio-physico-chemical properties and is relevant for transport and transformation processes but is largely unknown at the molecular scale. The objective of this study was an extended characterization of the OM composition at intact biopore and aggregate surfaces. Specifically, we aimed to improve the interpretation of data obtained with Fourier transform infrared spectroscopy in diffuse reflectance mode (DRIFT) by combining the signals from DRIFT spectra with data from pyrolysis-field ionization mass spectrometry (Py-FIMS) as a more detailed molecular-scale analysis. Samples were manually separated from the outermost surfaces of earthworm burrows, coated and uncoated cracks, root channels, and pinhole fillings of the B-horizons of Luvisols developed from loess and glacial till. The OM at earthworm burrow walls was characterized by a mix of chemically labile aliphatic C-rich and more stable lignin and alkylaromatic compounds whereas the OM of coated cracks and pinholes was dominated by relatively stable heterocylic N and nitriles, and high-molecular aromatic compounds (benzonitrile and naphthalene). This more recalcitrant OM likely originated from the combustion of biomass and, in case of the till-derived Luvisol, from diesel exhausts. The OM composition of pore walls reflected the differences between biopores (i.e., topsoil and plant residual, worm activity) and cracks (i.e., solutes and colloids, rapid percolation). The information of Py-FI mass spectra enabled the assignment of OM functional groups also from spectral regions of overlapping DRIFT signal intensities to specific OM compound classes. In particular, bands from C=O and C=C bonds in the infrared range of wave number 1688 … 1565 cm-1 were related to highly stable, chemically recalcitrant OM components such as heterocyclic N-compounds, benzonitrile and naphthalene. Based on such relations, the OM composition at intact soil structural surfaces relevant for sorption and wettability could be characterized in more detail even by using DRIFT spectroscopy.

Insights into the diversity of NOD-like receptors: Identification and expression analysis of NLRC3, NLRC5 and NLRX1 in rainbow trout.

PubMed

Álvarez, Claudio A; Ramírez-Cepeda, Felipe; Santana, Paula; Torres, Elisa; Cortés, Jimena; Guzmán, Fanny; Schmitt, Paulina; Mercado, Luis

2017-07-01

Nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) are efficient soluble intracellular sensors that activate defense mechanisms against pathogens. In teleost fish, the involvement of NLRs in the immune response is not well understood. However, recent work has evidenced the expression of different NLRs in response to some pathogen associated molecular patterns (PAMPs). In the present work, the cDNA sequence encoding three new NOD-like receptors were identified in Oncorhynchus mykiss, namely OmNLRC3, OmNLRC5 and OmNLRX1. Results showed that their sequences coded for proteins of 1135, 836 and 1010 amino acids, respectively. The deduced protein sequences of all receptors showed characteristic domains of this receptor family, such as leucine rich repeats and NACHT domain. Phylogenetic analysis revealed a high degree of identity with other NOD-like receptors and they are clustered into different families. Transcript expression analysis indicated that OmNLRs are constitutively expressed in liver, spleen, intestine, gill, skin and brain. OmNLR expression was upregulated in kidney and gills from rainbow trout in response to LPS. In order to give new insights into the function of these new NLR members, an in vitro model of immune stimulation was established using the rainbow trout cell line RTgill-W1. Expression analysis revealed that RTgill-W1 overexpressed proinflammatory cytokines in response to LPS and poly I:C alongside with a differential overexpression of OmNLRC3, OmNLRC5 and OmNLRX1. The expression of OmNLRC5 was further verified at the protein level by immunofluorescence. Finally, the effect of the overexpressed cytokines on the OmNLR expression by RTgill-W1 cells was assessed, suggesting a regulatory mechanism on OmNLRC3 expression. Overall, results suggest that O. mykiss NOD-like receptors could play a key role in the defense mechanisms of teleost through PAMP recognition. Future studies will focus on gills which could be related with a key sensor mucosal system in one of the most environmentally fish exposed tissues. Copyright © 2017 Elsevier Ltd. All rights reserved.

The catecholestrogen, 2-hydroxyestradiol-17beta, acts as a G protein-coupled estrogen receptor 1 (GPER/GPR30) antagonist to promote the resumption of meiosis in zebrafish oocytes.

PubMed

Chourasia, Tapan K; Pang, Yefei; Thomas, Peter

2015-03-01

Estradiol-17beta (E2) maintains high cAMP levels and meiotic arrest in zebrafish oocytes through activation of G protein-coupled estrogen receptor (GPER). The catecholestrogen 2-hydroxyestradiol-17beta (2-OHE2) has an opposite effect to that of E2 on oocyte maturation (OM) and cAMP levels in Indian catfish oocytes. We tested the hypothesis that 2-OHE2 is produced in zebrafish ovaries and promotes the resumption of oocyte meiosis through its action as a GPER antagonist. Ovarian 2-OHE2 production by estrogen-2-hydroxylase (EH) was up-regulated by gonadotropin treatment at the onset of OM, consistent with a physiological role for 2-OHE2 in regulating OM. The increases in EH activity and OM were blocked by treatment with CYP1A1 and CYP1B1 inhibitors. Expression of cyp1a, cyp1b1, and cyp1c mRNAs was increased by gonadotropin treatment, further implicating these Cyp1s in 2-OHE2 synthesis prior to OM. Conversely, aromatase activity and cyp19a1 mRNA expression declined during gonadotropin induction of OM. 2-OHE2 treatment significantly increased spontaneous OM in defolliculated zebrafish oocytes and reversed the inhibition of OM by E2 and the GPER agonist G-1. 2-OHE2 was an effective competitor of [(3)H]-E2 binding to recombinant zebrafish GPER expressed in HEK-293 cells. 2-OHE2 also antagonized estrogen actions through GPER on cAMP production in zebrafish oocytes, resulting in a reduction in cAMP levels. Stimulation of OM by 2-OHE2 was blocked by pretreatment of defolliculated oocytes with the GPER antibody. Collectively, the results suggest that 2-OHE2 functions as a GPER antagonist and promotes OM in zebrafish through blocking GPER-dependent E2 inhibition of the resumption of OM. © 2015 by the Society for the Study of Reproduction, Inc.

Optimising technology to measure functional vision, mobility and service outcomes for people with low vision or blindness: protocol for a prospective cohort study in Australia and Malaysia.

PubMed

Deverell, Lil; Meyer, Denny; Lau, Bee Theng; Al Mahmud, Abdullah; Sukunesan, Suku; Bhowmik, Jahar; Chai, Almon; McCarthy, Chris; Zheng, Pan; Pipingas, Andrew; Islam, Fakir M Amirul

2017-12-21

Orientation and mobility (O&M) specialists assess the functional vision and O&M skills of people with mobility problems, usually relating to low vision or blindness. There are numerous O&M assessment checklists but no measures that reduce qualitative assessment data to a single comparable score suitable for assessing any O&M client, of any age or ability, in any location. Functional measures are needed internationally to align O&M assessment practices, guide referrals, profile O&M clients, plan appropriate services and evaluate outcomes from O&M programmes (eg, long cane training), assistive technology (eg, hazard sensors) and medical interventions (eg, retinal implants). This study aims to validate two new measures of functional performance vision-related outcomes in orientation and mobility (VROOM) and orientation and mobility outcomes (OMO) in the context of ordinary O&M assessments in Australia, with cultural comparisons in Malaysia, also developing phone apps and online training to streamline professional assessment practices. This multiphase observational study will employ embedded mixed methods with a qualitative/quantitative priority: corating functional vision and O&M during social inquiry. Australian O&M agencies (n=15) provide the sampling frame. O&M specialists will use quota sampling to generate cross-sectional assessment data (n=400) before investigating selected cohorts in outcome studies. Cultural relevance of the VROOM and OMO tools will be investigated in Malaysia, where the tools will inform the design of assistive devices and evaluate prototypes. Exploratory and confirmatory factor analysis, Rasch modelling, cluster analysis and analysis of variance will be undertaken along with descriptive analysis of measurement data. Qualitative findings will be used to interpret VROOM and OMO scores, filter statistically significant results, warrant their generalisability and identify additional relevant constructs that could also be measured. Ethical approval has been granted by the Human Research Ethics Committee at Swinburne University (SHR Project 2016/316). Dissemination of results will be via agency reports, journal articles and conference presentations. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

PV O&M Cost Model and Cost Reduction

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

Walker, Andy

This is a presentation on PV O&M cost model and cost reduction for the annual Photovoltaic Reliability Workshop (2017), covering estimating PV O&M costs, polynomial expansion, and implementation of Net Present Value (NPV) and reserve account in cost models.

OM85-BV Induced the Productions of IL-1β, IL-6, and TNF-α via TLR4- and TLR2-Mediated ERK1/2/NF-κB Pathway in RAW264.7 Cells

PubMed Central

Luan, Hong; Zhang, Qian; Wang, Le; Wang, Chuanxiao; Zhang, Miao; Xu, Xiaoli; Zhou, Huan; Li, Xing'ai; Xu, Qing; He, Fan

2014-01-01

Broncho-Vaxom (OM85-BV) is an extract mixture from 8 strains of Gram+ and Gram− bacteria and plays an important role in anti-infection immune response by regulating macrophage activity and cytokine productions. However, the mechanism by which OM85-BV enhances the cytokine expression is still obscure. In this study, we evaluated the effects of OM85-BV on the productions of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) in RAW264.7 murine macrophages. Exposure of RAW264.7 cells to 100 μg/mL OM85-BV upregulated the expression of IL-1β, IL-6, and TNF-α at the mRNA and protein levels in a time- and dose-dependent manner. In addition, OM85-BV induced extracellular signal-regulated kinase (ERK) 1/2 and nuclear factor-kappa B (NF-κB) phosphorylation. Pretreatment with U0126 or Bay11-7082, respectively, could decrease IL-1β, IL-6, and TNF-α productions induced by OM85-BV. Application of Toll-like receptor (TLR) 4 or TLR2 small-interfering RNA (siRNA) into RAW264.7 cells could inhibit the productions of cytokines and ERK1/2 and NF-κB phosphorylation induced by OM85-BV. Consistent with this, downregulating either myeloid differentiation factor 88 (MyD88) or TRIF-related adaptor molecule (TRAM) gene with MyD88-siRNA or TRAM-siRNA separately could reduce the productions of cytokines and ERK1/2 and NF-κB phosphorylation induced by OM85-BV. Our study demonstrated that the productions of IL-1β, IL-6, and TNF-α induced by OM85-BV in RAW264.7 cells were through TLR4 and TLR2 signaling pathway-mediated activation of ERK1/2 and NF-κB. PMID:24605772

RNA interference-based resistance in transgenic tomato plants against Tomato yellow leaf curl virus-Oman (TYLCV-OM) and its associated betasatellite.

PubMed

Ammara, Um e; Mansoor, Shahid; Saeed, Muhammad; Amin, Imran; Briddon, Rob W; Al-Sadi, Abdullah Mohammed

2015-03-04

Tomato yellow leaf curl virus (TYLCV), a monopartite begomovirus (family Geminiviridae) is responsible for heavy yield losses for tomato production around the globe. In Oman at least five distinct begomoviruses cause disease in tomato, including TYLCV. Unusually, TYLCV infections in Oman are sometimes associated with a betasatellite (Tomato leaf curl betasatellite [ToLCB]; a symptom modulating satellite). RNA interference (RNAi) can be used to develop resistance against begomoviruses at either the transcriptional or post-transcriptional levels. A hairpin RNAi (hpRNAi) construct to express double-stranded RNA homologous to sequences of the intergenic region, coat protein gene, V2 gene and replication-associated gene of Tomato yellow leaf curl virus-Oman (TYLCV-OM) was produced. Initially, transient expression of the hpRNAi construct at the site of virus inoculation was shown to reduce the number of plants developing symptoms when inoculated with either TYLCV-OM or TYLCV-OM with ToLCB-OM to Nicotiana benthamiana or tomato. Solanum lycopersicum L. cv. Pusa Ruby was transformed with the hpRNAi construct and nine confirmed transgenic lines were obtained and challenged with TYLCV-OM and ToLCB-OM by Agrobacterium-mediated inoculation. For all but one line, for which all plants remained symptomless, inoculation with TYLCV-OM led to a proportion (≤25%) of tomato plants developing symptoms of infection. For inoculation with TYLCV-OM and ToLCB-OM all lines showed a proportion of plants (≤45%) symptomatic. However, for all infected transgenic plants the symptoms were milder and virus titre in plants was lower than in infected non-transgenic tomato plants. These results show that RNAi can be used to develop resistance against geminiviruses in tomato. The resistance in this case is not immunity but does reduce the severity of infections and virus titer. Also, the betasatellite may compromise resistance, increasing the proportion of plants which ultimately show symptoms.

Consequence of oxidant to monomer ratio on optical and structural properties of Polypyrrole thin film deposited by oxidation polymerization technique

NASA Astrophysics Data System (ADS)

Jatratkar, Aviraj A.; Yadav, Jyotiprakash B.; Kamat, Sandip V.; Patil, Vaishali S.; Mahadik, D. B.; Barshilia, Harish C.; Puri, Vijaya; Puri, R. K.

2015-05-01

This paper reports the effect of oxidant to monomer (O/M) ratio on optical and structural properties of Polypyrrole (PPy) thin film deposited by chemical oxidation polymerization technique. Noticeable changes have observed in the properties of PPy thin films with O/M ratio. Cauliflower structure have been observed in FE-SEM images, wherein grain size is observed to decrease with increase in O/M ratio. AFM results are in good agreement with FE-SEM results. From FTIR spectra it is found that, PPy is in highly oxidized form at low O/M ratio but oxidation decreased with increase in O/M ratio. Also C-C stretching vibrations of PPy ring is decreased whereas C=C stretching is increased with ratio. Absorption peak around 450 nm corresponds to π-π* transition and around 800 nm for polarons and bipolarons. The intensity of such peaks confirms the conductivity of PPy, which is observed maximum at low O/M ratio and found to decrease with increase in ratio. Optical band gap (BG) is found to increase from 2.07 eV to 2.11 eV with increase in the O/M ratio.

Seasonal pathways of organic matter within the Avilés submarine canyon: Food web implications

NASA Astrophysics Data System (ADS)

Romero-Romero, Sonia; Molina-Ramírez, Axayacatl; Höfer, Juan; Duineveld, Gerard; Rumín-Caparrós, Aitor; Sanchez-Vidal, Anna; Canals, Miquel; Acuña, José Luis

2016-11-01

The transport and fate of organic matter (OM) sources within the Avilés submarine canyon (Cantabrian Sea, Southern Bay of Biscay) were studied using carbon and nitrogen stable isotope ratios. The isotopic composition of settling particles and deep bottom sediments closely resembled that of surface particulate OM, and there were no marked differences in the isotopic composition of settling particles inside and outside of the AC. This indicates that the Avilés Canyon (AC) receives inputs of sinking OM mostly from the upper water column and less through advective near-bottom down-canyon transport. Sinking OM fluxes are of marine and terrestrial origin in proportions which vary seasonally. Analysis of δ13C in the canyon fauna indicates a dependence on OM mainly produced by marine phytoplankton. A tight coupling of isotopic signatures between pelagic organisms and benthic suspension feeders reflects an active biological vertical transport of OM from the surface to the deep-sea. The food web presented seasonal variations in the trophic niche width and the amplitude of the primary carbon sources, reflecting seasonality in the availability of fresh particulate OM. Those seasonal changes are larger for benthic organisms of lower trophic levels.

Air Pollution and Otitis Media in Children: A Systematic Review of Literature.

PubMed

Bowatte, Gayan; Tham, Rachel; Perret, Jennifer L; Bloom, Michael S; Dong, Guanghui; Waidyatillake, Nilakshi; Bui, Dinh; Morgan, Geoffrey G; Jalaludin, Bin; Lodge, Caroline J; Dharmage, Shyamali C

2018-02-03

Young children are particularly vulnerable to otitis media (OM) which globally affects over 80% of children below the age of 3 years. Although there is convincing evidence for an association between environmental tobacco smoke exposure and OM in children, the relationship with ambient air pollution is not clear. We aimed to systematically review the literature on the relationship between ambient air pollution exposure and OM in children. A systematic search was performed in PubMed and EMBASE databases. Of 934 references identified, 24 articles were included. There is an increasing body of evidence supporting an association between higher ambient air pollution exposure and a higher risk of OM in children. While NO₂ showed the most consistent association with OM, other specific pollutants showed inconsistent associations. Studies were mainly conducted in high/middle income countries with limited evidence from low-income countries. Although there was a general consensus that higher air pollution exposure is associated with a greater prevalence of OM, the evidence for associations with specific pollutants is inconsistent. More well-designed studies on associations between specific air pollutants as risk factors for OM are warranted, especially in low income countries with high air pollution levels.

Air Pollution and Otitis Media in Children: A Systematic Review of Literature

PubMed Central

Tham, Rachel; Perret, Jennifer L.; Bloom, Michael S.; Dong, Guanghui; Waidyatillake, Nilakshi; Bui, Dinh; Morgan, Geoffrey G.; Jalaludin, Bin; Lodge, Caroline J.

2018-01-01

Young children are particularly vulnerable to otitis media (OM) which globally affects over 80% of children below the age of 3 years. Although there is convincing evidence for an association between environmental tobacco smoke exposure and OM in children, the relationship with ambient air pollution is not clear. We aimed to systematically review the literature on the relationship between ambient air pollution exposure and OM in children. A systematic search was performed in PubMed and EMBASE databases. Of 934 references identified, 24 articles were included. There is an increasing body of evidence supporting an association between higher ambient air pollution exposure and a higher risk of OM in children. While NO2 showed the most consistent association with OM, other specific pollutants showed inconsistent associations. Studies were mainly conducted in high/middle income countries with limited evidence from low-income countries. Although there was a general consensus that higher air pollution exposure is associated with a greater prevalence of OM, the evidence for associations with specific pollutants is inconsistent. More well-designed studies on associations between specific air pollutants as risk factors for OM are warranted, especially in low income countries with high air pollution levels. PMID:29401661

NASA Astrophysics Data System (ADS)

2018-05-01

The main reactions considered in OM mineralization during early diagenesis of sediment are listed in Table 1. Under oxidant-depleted conditions, fermentation of metabolizable OM of general formula CxHyOz can yield acetate, CO2 and H2 (r1). Note that reaction r1 takes into account any source of CO2 during fermentation including the partial degradation of high molecular weight OM (HMW OM) into lower molecular weight OM (LMW OM; Corbett et al., 2013; Corbett et al., 2015). The products of this reaction yield CH4 via either acetate fermentation (r2) or hydrogenotrophy (r3). In addition, when electron acceptors (EAs), i.e., Fe(III), SO42-, and partially oxidized HS, are present, CH4 (r4) and OM (r5) can be oxidized to produce CO2. Here, nitrate and Mn oxyhydroxides were not considered as oxidants, owing to the very low concentration of the former (<2 μmol L-1) over the whole sampling interval and because Mn oxyhydroxides do not form under the slightly acidic conditions prevailing in these porewaters (Chappaz et al., 2008). In addition, we neglected precipitation and dissolution of carbonate minerals except for siderite precipitation (r6) due to its positive SI values (SI ≥ 0.5).

A framework for the identification of reusable processes

NASA Astrophysics Data System (ADS)

de Vries, Marné; Gerber, Aurona; van der Merwe, Alta

2013-11-01

A significant challenge that faces IT management is that of aligning the IT infrastructure of an enterprise with its business goals and practices, also called business-IT alignment. A particular business-IT alignment approach, the foundation for execution approach, was well-accepted by practitioners due to a novel construct, called the operating model (OM). The OM supports business-IT alignment by directing the coherent and consistent design of business and IT components. Even though the OM is a popular construct, our previous research detected the need to enhance the OM, since the OM does not specify methods to identify opportunities for data sharing and process reuse in an enterprise. In this article, we address one of the identified deficiencies in the OM. We present a process reuse identification framework (PRIF) that could be used to enhance the OM in identifying process reuse opportunities in an enterprise. We applied design research to develop PRIF as an artefact, where the development process of PRIF was facilitated by means of the business-IT alignment model (BIAM). We demonstrate the use of the PRIF as well as report on the results of evaluating PRIF in terms of its usefulness and ease-of-use, using experimentation and a questionnaire.

Organic functional groups in the submicron aerosol at 82.5° N, 62.5° W from 2012 to 2014

NASA Astrophysics Data System (ADS)

Leaitch, W. Richard; Russell, Lynn M.; Liu, Jun; Kolonjari, Felicia; Toom, Desiree; Huang, Lin; Sharma, Sangeeta; Chivulescu, Alina; Veber, Dan; Zhang, Wendy

2018-03-01

The first multi-year contributions from organic functional groups to the Arctic submicron aerosol are documented using 126 weekly-integrated samples collected from April 2012 to October 2014 at the Alert Observatory (82.45° N, 62.51° W). Results from the particle transport model FLEXPART, linear regressions among the organic and inorganic components and positive matrix factorization (PMF) enable associations of organic aerosol components with source types and regions. Lower organic mass (OM) concentrations but higher ratios of OM to non-sea-salt sulfate mass concentrations (nss-SO4=) accompany smaller particles during the summer (JJA). Conversely, higher OM but lower OM / nss-SO4= accompany larger particles during winter-spring. OM ranges from 7 to 460 ng m-3, and the study average is 129 ng m-3. The monthly maximum in OM occurs during May, 1 month after the peak in nss-SO4= and 2 months after that of elemental carbon (EC). Winter (DJF), spring (MAM), summer and fall (SON) values of OM / nss-SO4= are 26, 28, 107 and 39 %, respectively, and overall about 40 % of the weekly variability in the OM is associated with nss-SO4=. Respective study-averaged concentrations of alkane, alcohol, acid, amine and carbonyl groups are 57, 24, 23, 15 and 11 ng m-3, representing 42, 22, 18, 14 and 5 % of the OM, respectively. Carbonyl groups, detected mostly during spring, may have a connection with snow chemistry. The seasonally highest O / C occurs during winter (0.85) and the lowest O / C is during spring (0.51); increases in O / C are largely due to increases in alcohol groups. During winter, more than 50 % of the alcohol groups are associated with primary marine emissions, consistent with Shaw et al. (2010) and Frossard et al. (2011). A secondary marine connection, rather than a primary source, is suggested for the highest and most persistent O / C observed during the coolest and cleanest summer (2013), when alcohol and acid groups made up 63 % of the OM. A secondary marine source may be a general feature of the summer OM, but higher contributions from alkane groups to OM during the warmer summers of 2012 (53 %) and 2014 (50 %) were likely due to increased contributions from combustion sources. Evidence for significant contributions from biomass burning (BB) was present in 4 % of the weeks. During the dark months (NDJF), 29, 28 and 14 % of the nss-SO4=, EC and OM were associated with transport times over the gas flaring region of northern Russia and other parts of Eurasia. During spring, those percentages dropped to 11 % for each of nss-SO4= and EC values, respectively, and there is no association of OM. Large percentages of the Arctic haze characterized at Alert likely have origins farther than 10 days of transport time and may be from outside of the Eurasian region. Possible sources of unusually high nss-SO4= and OM during September-October 2014 are volcanic emissions or the Smoking Hills' area of the Northwest Territories, Canada.

Observations and Measurements Design Patterns within INSPIRE

NASA Astrophysics Data System (ADS)

Schleidt, K.; Cox, S.; Grellet, S.; Lowe, D.; Lutz, M.; Portele, C.; Sarretta, A.; Ventouras, S.

2012-04-01

Several INSPIRE spatial data themes have been specified so that their scope, in addition to classical geographic information, includes measured, modelled or simulated data. The FprEN ISO 19156 standard on Observations and Measurements (O&M) was designed for the explicit purpose of creating application schemas for such data, and thus shall be used in INSPIRE as a basis for developing data models for these themes. The following INSPIRE themes have identified O&M as integrally relevant to their thematic domain and are including elements of O&M in their data specifications: • Geology • Oceanographic geographical features • Atmospheric conditions and Meteorological geographical features • Environmental monitoring facilities • Soil In addition to these themes, several other INSPIRE themes have been identified to which observational information, while not at the core of the data specification, is relevant. Some examples of this are the INSPIRE theme "Species distribution", where primary occurrence data could be provided together with the aggregate distribution, as well as "Industrial and production facilities", where the provision of emissions data on such facilities would be useful for various environmental reporting obligations. While the O&M standard provides a generic framework for the provision of measurement data, it is also kept very abstract, and there are many ways of implementing the core structures in specific application schemas. In order to assure the consistent application of the O&M classes and properties across different INSPIRE themes, a cross-thematic working group on the use of O&M in INSPIRE has been convened. This group has analysed the requirements towards O&M within INSPIRE, identified the types of O&M design patterns required in INSPIRE and developed both additional classes identified as necessary within INSPIRE as well as guidelines detailing how this standard is to be used within INSPIRE. Some examples for these additional classes are: • the ObservationCollection class (which was included in O&M v1.0, but has been removed in the final version of FprEN ISO 19156), that serves as a container for semantically grouping multiple observations; • the ObservableProperty class, that provides structures for the definition of complex observed properties including statistical qualifiers and constraints; • the ObservingCapabilities class for providing information about the types of measurements that a facility or instrument can make in a way that reflects the semantics of the actual Observations; • the further specialization of the OM_Process (with identifier, responsible party, etc.) class that is primarily empty within the O&M concept. These additional classes and guidelines can be used by the various INSPIRE themes that integrate or reference the O&M standard, as well as for other specifications that are created outside of the INSPIRE process and extend existing INSPIRE specifications with the use of O&M. The INSPIRE O&M guidelines also contain generic analysis which may be of interest when evaluating how and whether to apply O&M to a particular domain. The results of this work will be presented.

Determination of total tin in silicate rocks by graphite furnace atomic absorption spectrometry

USGS Publications Warehouse

Elsheimer, H.N.; Fries, T.L.

1990-01-01

A method is described for the determination of total tin in silicate rocks utilizing a graphite furnace atomic absorption spectrometer with a stabilized-temperature platform furnace and Zeeman-effect background correction. The sample is decomposed by lithium metaborate fusion (3 + 1) in graphite crucibles with the melt being dissolved in 7.5% hydrochloric acid. Tin extractions (4 + 1 or 8 + 1) are executed on portions of the acid solutions using a 4% solution of tricotylphosphine oxide in methyl isobutyl ketone (MIBK). Ascorbic acid is added as a reducing agent prior to extraction. A solution of diammonium hydrogenphosphate and magnesium nitrate is used as a matrix modifier in the graphite furnace determination. The limit of detection is > 10 pg, equivalent to > 1 ??g l-1 of tin in the MIBK solution or 0.2-0.3 ??g g-61 in the rock. The concentration range is linear between 2.5 and 500 ??g l-1 tin in solution. The precision, measured as relative standard deviation, is < 20% at the 2.5 ??g l-1 level and < 7% at the 10-30 ??g l-1 level of tin. Excellent agreement with recommended literature values was found when the method was applied to the international silicate rock standards BCR-1, PCC-1, GSP-1, AGV-1, STM-1, JGb-1 and Mica-Fe. Application was made to the determination of tin in geological core samples with total tin concentrations of the order of 1 ??g g-1 or less.

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

Cantrill, E.R.; Ray, A.; Stevens, M.G.

The interfacial bond between fiber and matrix is one of the most important factors influencing fiber-reinforced composites. This is particularly apparent in cellulose wood pulp reinforced cement/quartz composites cured by autoclaving under saturated steam at 180 C. Scanning electron microscopy (SEM) studies have shown that there is little modification of the surface of the hydrated calcium silicate matrix immediately adjacent to the cellulose fiber surface, provided the cellulose fiber is relatively free from lignin, hemicelluloses, or chemicals from the pulping process. Coutts & Campbell (1979) in their investigation of water cured cement composites, applied several commercial coupling agents to cellulosemore » fibres and established that two of these agents significantly increased the strength of the interfacial bond. In this paper, the surface of cellulose fibres was modified by sodium silicate, CTBN [carboxy terminated butadiene nitrile] and ATBN [amino terminated butadiene nitrile] in order to enhance the interfacial bond, and also to increase the resistance of the cellulose to oxidation, alkaline or thermal degradation, and algal attack. Algal attack can occur as the calcium silicate matrix is neutralized by atmospheric carbonation, especially in external wall board applications of the sheet composite. In addition, suitable coatings will protect the cellulose fiber from degradation arising from the presence of elevated temperature and alkaline solutions during the autoclaving process. Cellulose reinforced composites with substandard strengths, due to inhibited autoclave reactions, cannot be reautoclaved as the resultant material is too brittle due, in part, to the degradation of the cellulose fiber.« less

A-thermal elastic behavior of silicate glasses.

PubMed

Rabia, Mohammed Kamel; Degioanni, Simon; Martinet, Christine; Le Brusq, Jacques; Champagnon, Bernard; Vouagner, Dominique

2016-02-24

Depending on the composition of silicate glasses, their elastic moduli can increase or decrease as function of the temperature. Studying the Brillouin frequency shift of these glasses versus temperature allows the a-thermal composition corresponding to an intermediate glass to be determined. In an intermediate glass, the elastic moduli are independent of the temperature over a large temperature range. For sodium alumino-silicate glasses, the a-thermal composition is close to the albite glass (NaAlSi3O8). The structural origin of this property is studied by in situ high temperature Raman scattering. The structure of the intermediate albite glass and of silica are compared at different temperatures between room temperature and 600 °C. When the temperature increases, it is shown that the high frequency shift of the main band at 440 cm(-1) in silica is a consequence of the cristobalite-like alpha-beta transformation of 6-membered rings. This effect is stronger in silica than bond elongation (anharmonic effects). As a consequence, the elastic moduli of silica increase as the temperature increases. In the albite glass, the substitution of 25% of Si(4+) ions by Al(3+) and Na(+) ions decreases the proportion of SiO2 6-membered rings responsible for the silica anomaly. The effects of the silica anomaly balance the anharmonicity in albite glass and give rise to an intermediate a-thermal glass. Different networks, formers or modifiers, can be added to produce different a-thermal glasses with useful mechanical or chemical properties.

Treponema denticola Outer Membrane Enhances the Phagocytosis of Collagen-Coated Beads by Gingival Fibroblasts

PubMed Central

Battikhi, Tulin; Lee, Wilson; McCulloch, Christopher A. G.; Ellen, Richard P.

1999-01-01

Human gingival fibroblasts (HGFs) degrade collagen fibrils in physiological processes by phagocytosis. Since Treponema denticola outer membrane (OM) extract perturbs actin filaments, important structures in phagocytosis, we determined whether the OM affects collagen phagocytosis in vitro by HGFs. Phagocytosis was measured by flow cytometric assessment of internalized collagen-coated fluorescent latex beads. Confluent HGFs pretreated with T. denticola ATCC 35405 OM exhibited an increase in the percentage of collagen phagocytic cells (phagocytosis index [PI]) and in the number of beads per phagocytosing cell (phagocytic capacity [PC]) compared with untreated controls. The enhancement was swift (within 15 min) and was still evident after 1 day. PI and PC of HGFs for bovine serum albumin (BSA)-coated beads were also increased, indicating a global increase in phagocytic processes. These results contrasted those for control OM from Veillonella atypica ATCC 17744, which decreased phagocytosis. The T. denticola OM-induced increase in bead uptake was eliminated by heating the OM and by depolymerization of actin filaments by cytochalasin D treatment of HGFs. Fluid-phase accumulation of lucifer yellow was enhanced in a saturable, concentration-dependent, transient manner by the T. denticola OM. Our findings were not due to HGF detachment or cytotoxicity in response to the T. denticola OM treatment since the HGFs exhibited minimal detachment from the substratum; they did not take up propidium iodide; and there was no change in their size, granularity, or content of sub-G1 DNA. We conclude that a heat-sensitive component(s) in T. denticola OM extract stimulates collagen phagocytosis and other endocytic processes such as nonspecific phagocytosis and pinocytosis by HGFs. PMID:10024564

Long-term viability and differentiation of bovine oviductal monolayers: bidimensional versus three-dimensional culture.

PubMed

Gualtieri, R; Mollo, V; Braun, S; Barbato, V; Fiorentino, I; Talevi, R

2012-10-15

Different in vitro models have been developed to study the interaction of gametes and embryos with the maternal tract. In cattle, the interaction of the oviduct with gametes and embryos have been classically studied using oviductal explants or monolayers (OMs). Explants are well differentiated but have to be used within 24 h after collection, whereas OMs can be used for a longer time after cell confluence but dedifferentiate during culture, losing cell polarity and ciliation. Herein, OMs were cultured either in M199 plus 10% fetal calf serum or in a semidefined culture medium (Gray's medium), in an immersed condition on collagen-coated coated microporous polyester or polycarbonate inserts under air-liquid interface conditions. The influence of culture conditions on long-term viability and differentiation of OMs was evaluated through scanning electron microscopy, localization of centrin and tubulin at the confocal laser scanning microscope, and assessment of maintenance of viability of sperm bound to OMs. Findings demonstrated that OMs cultured in an immersed condition with Gray's medium retain a better morphology, do not exhibit signs of crisis at least until 3 wks postconfluence, and maintain the viability of bound sperm significantly better than parallel OMs cultured in M199 plus 10% fetal calf serum. OM culture with Gray's medium in air-liquid interface conditions on porous inserts promotes cell polarity, ciliation, and maintenance of bound sperm viability at least until 3 wks postconfluence. In conclusion, oviduct culture in Gray's medium in an immersed or air-liquid condition allows long-term culture and, in the latter case, also ciliation of bovine OMs, and may represent in vitro systems that mimick more closely the biological processes modulated by the oviduct in vivo. Copyright © 2012 Elsevier Inc. All rights reserved.

Bacterial extract (OM-85) with human-equivalent doses does not inhibit the development of asthma in a murine model.

PubMed

Rodrigues, A; Gualdi, L P; de Souza, R G; Vargas, M H M; Nuñez, N K; da Cunha, A A; Jones, M H; Pinto, L A; Stein, R T; Pitrez, P M

OM-85 is an immunostimulant bacterial lysate, which has been proven effective in reducing the number of lower airways infections. We investigated the efficacy of the bacterial lysate OM-85 in the primary prevention of a murine model of asthma. In the first phase of our study the animals received doses of 0.5μg, 5μg and 50μg of OM-85 through gavage for five days (days -10 to -6 of the protocol), 10 days prior to starting the sensitisation with ovalbumin (OVA), in order to evaluate the results of dose-response protocols. A single dose (5μg) was then chosen in order to verify in detail the effect of OM-85 on the pulmonary allergic response. Total/differential cells count and cytokine levels (IL-4, IL-5, IL-13 and IFN-γ) from bronchoalveolar lavage fluid (BALF), OVA-specific IgE levels from serum, lung function and lung histopathological analysis were evaluated. OM-85 did not reduce pulmonary eosinophilic response, regardless of the dose used. In the phase protocol using 5μg/animal of OM-85, no difference was shown among the groups studied, including total cell and eosinophil counts in BALF, serum OVA-specific IgE, lung histopathologic findings and lung resistance. However, OM-85 decreased IL-5 and IL-13 levels in BALF. OM-85, administered in early life in mice in human-equivalent doses, does not inhibit the development of allergic pulmonary response in mice. Copyright © 2016 SEICAP. Published by Elsevier España, S.L.U. All rights reserved.

Spatial variability of organic matter molecular composition and elemental geochemistry in surface sediments of a small boreal Swedish lake

NASA Astrophysics Data System (ADS)

Tolu, Julie; Rydberg, Johan; Meyer-Jacob, Carsten; Gerber, Lorenz; Bindler, Richard

2017-04-01

The composition of sediment organic matter (OM) exerts a strong control on biogeochemical processes in lakes, such as those involved in the fate of carbon, nutrients and trace metals. While between-lake spatial variability of OM quality is increasingly investigated, we explored in this study how the molecular composition of sediment OM varies spatially within a single lake and related this variability to physical parameters and elemental geochemistry. Surface sediment samples (0-10 cm) from 42 locations in Härsvatten - a small boreal forest lake with a complex basin morphometry - were analyzed for OM molecular composition using pyrolysis gas chromatography mass spectrometry for the contents of 23 major and trace elements and biogenic silica. We identified 162 organic compounds belonging to different biochemical classes of OM (e.g., carbohydrates, lignin and lipids). Close relationships were found between the spatial patterns of sediment OM molecular composition and elemental geochemistry. Differences in the source types of OM (i.e., terrestrial, aquatic plant and algal) were linked to the individual basin morphometries and chemical status of the lake. The variability in OM molecular composition was further driven by the degradation status of these different source pools, which appeared to be related to sedimentary physicochemical parameters (e.g., redox conditions) and to the molecular structure of the organic compounds. Given the high spatial variation in OM molecular composition within Härsvatten and its close relationship with elemental geochemistry, the potential for large spatial variability across lakes should be considered when studying biogeochemical processes involved in the cycling of carbon, nutrients and trace elements or when assessing lake budgets.

A highly bioavailable omega-3 free fatty acid formulation improves the cardiovascular risk profile in high-risk, statin-treated patients with residual hypertriglyceridemia (the ESPRIT trial).

PubMed

Maki, Kevin C; Orloff, David G; Nicholls, Stephen J; Dunbar, Richard L; Roth, Eli M; Curcio, Danielle; Johnson, Judith; Kling, Douglas; Davidson, Michael H

2013-09-01

A novel omega-3 formulation in free fatty acid form (OM3-FFA) has as much as 4-fold greater bioavailability than ethyl ester forms and reduces triglyceride (TG) levels in patients with severe hypertriglyceridemia. This study was designed to evaluate the efficacy of adding OM3-FFA (2 or 4 g/d) to statin therapy for lowering non-HDL-C and TG levels in subjects with persistent hypertriglyceridemia and at high risk for cardiovascular disease. In this double-blind, parallel-group study, 647 diet-stable patients with fasting TG levels ≥ 200 mg/dL and <500 mg/dL (treated with a maximally tolerated dose of statin or statin with ezetimibe) and at high risk for cardiovascular disease were randomized to 6 weeks of treatment with capsules of control (olive oil [OO]) 4 g/d, OM3-FFA 2 g/d (plus 2 g/d OO), or OM3-FFA 4 g/d. Assessments included fasting serum levels of lipids and apolipoproteins (apo); plasma concentrations of eicosapentaenoic acid, docosahexaenoic acid, docosapentaenoic acid, and arachidonic acid; and laboratory safety values and adverse events. In the 627 subjects in the intention to treat sample, non-HDL-C levels were reduced with OM3-FFA 2 g/d and OM3-FFA 4 g/d (-3.9% and -6.9%, respectively) compared with OO (-0.9%) (both, P < 0.05), as were TG levels (-14.6% and -20.6%, respectively, vs -5.9%; both, P < 0.001). LDL-C levels increased with OM3-FFA 2 g/d (4.6%) compared with OO (1.1%) (P = 0.025) but not with OM3-FFA 4 g/d (1.3%). Total cholesterol and VLDL-C concentrations were reduced compared with OO with both OM3-FFA dosages, and the total cholesterol/HDL-C ratio and apo AI and apo B levels were significantly lowered with OM3-FFA 4 g/d only (all at least P < 0.05). Percent changes from baseline in HDL-C did not differ between OO and either OM3-FFA group. Plasma concentrations of docosahexaenoic acid, eicosapentaenoic acid, and docosapentaenoic acid were significantly increased and arachidonic acid was significantly reduced in both OM3-FFA treatment groups compared with the OO responses (all, P < 0.001). Withdrawals related to treatment-emergent adverse events ranged from 0.9% with OO to 3.2% with OM3-FFA 4 g/d. OM3-FFA was well tolerated and lowered non-HDL-C and TG levels at both 2- and 4-g/d dosages in patients with persistent hypertriglyceridemia taking a statin, with the 4-g/d dosage providing incremental improvements compared with 2 g/d. © 2013 Elsevier HS Journals, Inc. All rights reserved.

Comparative geochemistry of Indian margin (Arabian Sea) sediments: Estuary to continental slope.

NASA Astrophysics Data System (ADS)

Cowie, Greg; Mowbray, Stephen; Kurian, Siby; Sarkar, Amit; White, Carol; Anderson, Amy; Vergnaud, Bianca; Johnstone, Gisele; Brear, Samuel; Woulds, Clare; Naqvi, Wajih; Kitazato, Hiroshi

2014-05-01

Factors controlling the distribution of organic matter in the Arabian Sea have been the subject of much research and debate ever since organic-rich slope deposits were associated with the mid-water oxygen minimum zone (OMZ) However, the debate remains open, and numerous interacting factors have been invoked as important controls. A limitation of most previous studies is that they have been restricted to limited portions of the margin, and have not included molecular-level tracers that allow distinction of organic matter (OM) source and degradation state as factors in OM distribution. We report results from sites across the Indian margin of the Arabian Sea, which were analysed for carbon and nitrogen compositions (elemental and isotopic), grain size and indices of OM source and degradation state. Site locations ranged from the Mandovi/Zuari estuaries to depths of ~2000m on the continental slope, thus spanning both the semi-permanent OMZ on the upper slope (~200-1300m) and the seasonal hypoxic zone that impinges on the shelf. Source indices showed mixed marine and terrigenous OM within the estuaries, but overwhelming predominance (80%+) of marine OM on the shelf and slope, even in nearshore deposits. Thus, riverine OM is heavily diluted or efficiently remineralised within or immediately offshore of the estuaries. Any terrigenous OM that is exported appears to be retained in nearshore muds; lignin phenols indicate that the small terrigenous OM content of slope sediments is of different origin, potentially from rivers to the north. Organic C contents of surface shelf and slope sediments varied from <0.5 wt% in relict shelf sands to a maximum of >7 wt% at upper slope sites within the OMZ, then decreasing to ≤1wt% at 2000m. However, major variability (~5 wt%) occured within the OMZ at sites with near-identical depths and bottom-water oxygen. A strong relationship between organic C and grain size was seen for OMZ sediments, but lower C loadings were found for sites on the shelf and below the OMZ. Diagenetic indices confirmed that lower C content below the OMZ is associated with greater extent of OM degradation, but that C-poor shelf sediments are not consistently more degraded than those within the OMZ. Together, results indicate that OM enrichment on the upper slope, where it occurs, can be explained by winnowing or other physical processes on the shelf combined with progressive OM degradation with increasing oxygen exposure below the OMZ. Reduced oxygen exposure may contribute to observed OM enrichment with the OMZ, but hydrodynamic processes are the overriding control on sediment OM distribution, even within the OMZ.

Organic matter dynamics along a salinity gradient in Siberian steppe soils

NASA Astrophysics Data System (ADS)

Bischoff, Norbert; Mikutta, Robert; Shibistova, Olga; Dohrmann, Reiner; Herdtle, Daniel; Gerhard, Lukas; Fritzsche, Franziska; Puzanov, Alexander; Silanteva, Marina; Grebennikova, Anna; Guggenberger, Georg

2018-01-01

Salt-affected soils will become more frequent in the next decades as arid and semiarid ecosystems are predicted to expand as a result of climate change. Nevertheless, little is known about organic matter (OM) dynamics in these soils, though OM is crucial for soil fertility and represents an important carbon sink. We aimed at investigating OM dynamics along a salinity and sodicity gradient in the soils of the southwestern Siberian Kulunda steppe (Kastanozem, non-sodic Solonchak, Sodic Solonchak) by assessing the organic carbon (OC) stocks, the quantity and quality of particulate and mineral-associated OM in terms of non-cellulosic neutral sugar contents and carbon isotopes (δ13C, 14C activity), and the microbial community composition based on phospholipid fatty acid (PLFA) patterns. Aboveground biomass was measured as a proxy for plant growth and soil OC inputs. Our hypotheses were that (i) soil OC stocks decrease along the salinity gradient, (ii) the proportion and stability of particulate OM is larger in salt-affected Solonchaks compared to non-salt-affected Kastanozems, (iii) sodicity reduces the proportion and stability of mineral-associated OM, and (iv) the fungi : bacteria ratio is negatively correlated with salinity. Against our first hypothesis, OC stocks increased along the salinity gradient with the most pronounced differences between topsoils. In contrast to our second hypothesis, the proportion of particulate OM was unaffected by salinity, thereby accounting for only < 10 % in all three soil types, while mineral-associated OM contributed > 90 %. Isotopic data (δ13C, 14C activity) and neutral sugars in the OM fractions indicated a comparable degree of OM transformation along the salinity gradient and that particulate OM was not more persistent under saline conditions. Our third hypothesis was also rejected, as Sodic Solonchaks contained more than twice as much mineral-bound OC than the Kastanozems, which we ascribe to the flocculation of OM and mineral components under higher ionic strength conditions. Contrary to the fourth hypothesis, the fungi : bacteria ratio in the topsoils remained fairly constant along the salinity gradient. A possible explanation for why our hypotheses were not affirmed is that soil moisture covaried with salinity along the transect, i.e., the Solonchaks were generally wetter than the Kastanozems. This might cause comparable water stress conditions for plants and microorganisms, either due to a low osmotic or a low matric potential and resulting in (i) similar plant growth and hence soil OC inputs along the transect, (ii) a comparable persistence of particulate OM, and (iii) unaffected fungi : bacteria ratios. We conclude that salt-affected soils contribute significantly to the OC storage in the semiarid soils of the Kulunda steppe, while most of the OC is associated with minerals and is therefore effectively sequestered in the long term.

Silicate calculi, a rare cause of kidney stones in children.

PubMed

Taşdemir, Mehmet; Fuçucuoğlu, Dilara; Özman, Oktay; Sever, Lale; Önal, Bülent; Bilge, Ilmay

2017-02-01

Urinary silicate calculi in humans are extremely rare. Reported cases of silicate calculi are mostly documented in adults and are commonly related to an excessive intake of magnesium trisilicate in food or drugs. Published studies on the presence of silicate calculi in children are scarce. Three cases of silicate kidney stones without prior silicate intake are reported. Two patients underwent surgical treatment, and the third patient was treated using conservative methods. Urinalysis revealed no underlying metabolic abnormalities. Analyses revealed that silicate was the major component of the stones. Siliceous deposits in urinary stones may be more common than anticipated, and the underlying pathophysiology remains to be clarified.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is lowered toward a transporter. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is lowered toward a transporter. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

KENNEDY SPACE CENTER, FLA. - Technicians in the Orbiter Processing Facility oversee removal of one of two orbital maneuvering system (OMS) pods from Endeavour. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - Technicians in the Orbiter Processing Facility oversee removal of one of two orbital maneuvering system (OMS) pods from Endeavour. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility prepare to remove one of two orbital maneuvering system (OMS) pods from Endeavour. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility prepare to remove one of two orbital maneuvering system (OMS) pods from Endeavour. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is suspended overhead. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is suspended overhead. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is lowered onto a transporter. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is lowered onto a transporter. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

Predictors of Operative Mortality for Coronary Bypass Grafting in Patients with Ischemic Heart Disease

PubMed Central

Langou, Rene A.; Wiles, John C.; Peduzzi, Peter N.; Hammond, Graeme; Cohen, Lawrence S.

1978-01-01

Predictors for operative mortality (OM) were studied in 172 consecutive patients (pts) undergoing coronary artery grafts (CAG) for angina pectoris. Seventy eight pts had Class IV angina; of the 147 patients given propranolol, 41 were gradually withdrawn from propranolol and finally discontinued 24 hours before surgery, and 106 were abruptly withdrawn from propranolol 24 hours before CAG; 20 pts had left main coronary disease; 156 pts had cardiopulmonary bypass (CPB) time shorter than 20 minutes, and 16 pts had a CPB longer than 120 minutes. The operative mortality was 5.2% (9/172) for the entire group. Class IV angina (OM 7%), abrupt propranolol withdrawal (OM 6.6%), left main coronary artery disease (OM 25%), and CPB longer than 120 minutes (OM 50%), all significantly increased OM. These variables were interdependent, however, as many pts belonged to several predictor categories, combinations of predictors were examined, in order to more accurately predict the risk of individual pts. The combination of left main coronary artery disease and CPB longer than 120 minutes; and Class IV angina and CPB longer than 120 minutes were significantly associated with higher operative mortality. We conclude that Class IV angina, abrupt propranolol withdrawal, left main coronary artery disease and prolonged CPB are potent, interdependent predictors of OM in pts undergoing CAG. Consideration of these predictors, alone and in combination, allows effective prediction of OM for CAG in patients with stable angina pectoris. PMID:307873

Prevention of respiratory tract infections with bacterial lysate OM-85 bronchomunal in children and adults: a state of the art

PubMed Central

2013-01-01

Respiratory tract infections (RTIs) are a leading cause of morbidity and also represent a cause of death in some parts of the world. The treatment of RTIs implies a continuous search for stronger therapies and represents an economical burden for health services and society. In this context the prevention of infections is absolutely required. The use of bacterial lysates as immuno-modulators to boost immunological response is widely debated. Aim of this review is to summarize the main clinical studies on the effect of the bacterial lysate OM-85 in treating RTIs in susceptible subjects - namely children and chronic obstructive pulmonary disease (COPD)-affected adults. Results from clinical trials and recent systematic reviews are reported. The results show that mean number of RTIs decreases upon treatment with OM-85, as measured by frequency of exacerbations or number of antibiotic courses. Data from systematic reviews indicated that OM-85 is particularly beneficial in children at high risk of RTIs. In COPD-affected adults, clinical studies showed that treatment with OM-85 reduced exacerbations, although systematic reviews did not legitimate the protective effect of OM-85 toward COPD as significant. The use of OM-85 could be efficacious in reducing exacerbation frequency of RTIs in children and adults at risk. However further high-quality studies are needed to better explain the mechanism of action and confirm the beneficial results of OM85. PMID:23692890

Physical Processes Dictate Early Biogeochemical Dynamics of Soil Pyrogenic Organic Matter in a Subtropical Forest Ecosystem

NASA Astrophysics Data System (ADS)

Stuart, Jason M.; Anderson, Russell; Lazzarino, Patrick; Kuehn, Kevin A.; Harvey, Omar R.

2018-05-01

Quantifying links between pyOM dynamics, environmental factors and processes is central to predicting ecosystem function and response to future perturbations. In this study, changes in carbon (TC), nitrogen (TN) , pH and relative recalcitrance (R50) for pine- and cordgrass-derived pyOM were measured at 3-6 weeks intervals throughout the first year of burial in the soil. Objectives were to 1) identify key environmental factors and processes driving early-stage pyOM dynamics, and 2) develop quantitative relationships between environmental factors and changes in pyOM properties. The study was conducted in sandy soils of a forested ecosystem in the Longleaf pine range, US with a focus on links between changes in pyOM properties, fire history (FH), cumulative precipitation (Pcum), average temperature (Tavg) and soil residence time (SRT). Pcum, SRT and Tavg were the main factors controlling TC and TN accounting for 77-91% and 64-96% of their respective variability. Fire history, along with Pcum, SRT and Tavg, exhibited significant controlling effects on pyOM, pH and R50 - accounting for 48-91% and 88-93% of respective variability. Volatilization of volatiles and leaching of water-soluble components (in summer) and the sorption of exogenous organic matter (fall through spring) were most plausibly controlling pyOM dynamics in this study. Overall, our results point to climatic and land management factors and physicochemical process as the main drivers of pyOM dynamics in the pine ecosystems of the Southeastern US.

Ornamental marine species culture in the coral triangle: seahorse demonstration project in the Spermonde Islands, Sulawesi, Indonesia.

PubMed

Williams, Susan L; Janetski, Noel; Abbott, Jessica; Blankenhorn, Sven; Cheng, Brian; Crafton, R Eliot; Hameed, Sarah O; Rapi, Saipul; Trockel, Dale

2014-12-01

Ornamental marine species ('OMS') provide valuable income for developing nations in the Indo-Pacific Coral Triangle, from which most of the specimens are exported. OMS culture can help diversify livelihoods in the region, in support of management and conservation efforts to reduce destructive fishing and collection practices that threaten coral reef and seagrass ecosystems. Adoption of OMS culture depends on demonstrating its success as a livelihood, yet few studies of OMS culture exist in the region. We present a case study of a land-based culture project for an endangered seahorse (Hippocampus barbouri) in the Spermonde Islands, Sulawesi, Indonesia. The business model demonstrated that culturing can increase family income by seven times. A Strengths Weaknesses Opportunities Threats (SWOT) analysis indicated good collaboration among diverse stakeholders and opportunities for culturing non-endangered species and for offshoot projects, but complicated permitting was an issue as were threats of market flooding and production declines. The OMS international market is strong, Indonesian exporters expressed great interest in cultured product, and Indonesia is the largest exporting country for H. barbouri. Yet, a comparison of Indonesia ornamental marine fish exports to fish abundance in a single local market indicated that OMS culture cannot replace fishing livelihoods. Nevertheless, seahorse and other OMS culture can play a role in management and conservation by supplementing and diversifying the fishing and collecting livelihoods in the developing nations that provide the majority of the global OMS.

Intake of Diet Including 1% Ovomucoid for 4 Weeks Induces Oral Desensitization in Ovomucoid-Specific Allergic Mouse Model.

PubMed

Maeta, Akihiro; Sakamoto, Yoko; Yuki, Sayo; Takahashi, Kyoko

2017-01-01

We propose a new oral immunotherapy (OIT) method that includes a small amount of a food allergen in the diet. However, it is not clear whether this method will induce oral desensitization and immune tolerance. Therefore, we investigated the therapeutic effectiveness using a 1% food allergen diet in an allergic mouse model. C3H/HeJ mice were sensitized to ovomucoid (OM) in alum four times at 12-d intervals. Sensitized mice were divided into two groups: the OIT group (19% casein diet with 1% OM) and the non-treated group (20% casein diet without OM). The non-sensitized mice served as the non-allergy group. The OIT treatment was performed for 4 wk. To assess desensitization and immune tolerance, we performed oral and intraperitoneal OM challenges, assessed vascular permeability of the dorsal skin, and measured allergic biomarkers. The OIT group exhibited significantly lower oral symptom scores and vascular permeability than the non-treated group, but the two groups did not differ in intraperitoneal allergy symptom scores. Furthermore, the OIT group had significantly higher OM-specific IgA levels in their plasma than the non-treated group. However, the plasma levels of OM-specific IgE, IgG1, and IgG2a were not significantly different between the OIT and the non-treated groups. These results suggest that the proposed OIT using an OM-supplemented diet may induce desensitization, but not immune tolerance, in an OM allergic mouse model.

Ornamental Marine Species Culture in the Coral Triangle: Seahorse Demonstration Project in the Spermonde Islands, Sulawesi, Indonesia

NASA Astrophysics Data System (ADS)

Williams, Susan L.; Janetski, Noel; Abbott, Jessica; Blankenhorn, Sven; Cheng, Brian; Crafton, R. Eliot; Hameed, Sarah O.; Rapi, Saipul; Trockel, Dale

2014-12-01

Ornamental marine species (`OMS') provide valuable income for developing nations in the Indo-Pacific Coral Triangle, from which most of the specimens are exported. OMS culture can help diversify livelihoods in the region, in support of management and conservation efforts to reduce destructive fishing and collection practices that threaten coral reef and seagrass ecosystems. Adoption of OMS culture depends on demonstrating its success as a livelihood, yet few studies of OMS culture exist in the region. We present a case study of a land-based culture project for an endangered seahorse ( Hippocampus barbouri) in the Spermonde Islands, Sulawesi, Indonesia. The business model demonstrated that culturing can increase family income by seven times. A Strengths Weaknesses Opportunities Threats (SWOT) analysis indicated good collaboration among diverse stakeholders and opportunities for culturing non-endangered species and for offshoot projects, but complicated permitting was an issue as were threats of market flooding and production declines. The OMS international market is strong, Indonesian exporters expressed great interest in cultured product, and Indonesia is the largest exporting country for H. barbouri. Yet, a comparison of Indonesia ornamental marine fish exports to fish abundance in a single local market indicated that OMS culture cannot replace fishing livelihoods. Nevertheless, seahorse and other OMS culture can play a role in management and conservation by supplementing and diversifying the fishing and collecting livelihoods in the developing nations that provide the majority of the global OMS.

Composition of biomineral organic matrices with special emphasis on turbot (Psetta maxima) otolith and endolymph.

PubMed

Borelli, G; Mayer-Gostan, N; Merle, P L; De Pontual, H; Boeuf, G; Allemand, D; Payan, P

2003-06-01

The soluble organic matrix (OM) of various biominerals (red coral skeleton, oyster shell, sea urchin test, turbot otolith, chicken eggshell) was extracted after demineralization with acetic acid. The protein content of the OM varies strongly from 0.02 to 1.6 microg/mg biomineral whereas proteoglycans present less variations (from 0.7 to 1.4 microg/mg biomineral). Electrophoresis of biominerals OM shows differences in their protein pattern although several bands are present in all matrices. OM of all biominerals shows carbonic anhydrase activity but no activity was detectable in the endolymph. OM of all biominerals also displays an anticalcifying activity. After separation of the OM extracts by chloroform-methanol, 80% of the anticalcifying activity was found in the methanol phase except in the urchin test. After OM precipitation with trichloracetic acid, 70% of the activities was found in the supernatants. Partial biochemical characterization suggests that the anticalcifying factor is a polyanionic and water-soluble molecule, which could be proteoglycans. The endolymph surrounding the otolith also displays an anticalcifying activity although its inhibitous activity was 50 times lower than that of the otolith OM. However, the anticalcifying activity of the endolymph is assumed by a proteic structure (80% activity precipitated with TCA treatment). Our results suggest that both carbonic anhydrase and anticalcifying activities are widespread and play a significant role in the regulation of biomineral formation. Results are discussed in relation to the calcification process that takes place at the fluid-mineral interface.

Recovery of viruses from water by a modified flocculation procedure for second-step concentration.

PubMed Central

Dahling, D R; Wright, B A

1986-01-01

A reduction in virus recovery efficiencies stemming from a change in the commercial processing of powdered beef extract was reversed by the addition of Celite analytical filter aid. Supplementing beef extract with this silicate is recommended as a modification to the organic flocculation procedure for second-step concentration in monitoring for waterborne viruses. Considerable differences in virus recovery were found among lots of beef extract and Celite preparations; this indicates that the performance of each lot of these substances should be checked before use. PMID:3015024

Development of a 3D VHR seismic reflection system for lacustrine settings - a case study in Lake Geneva, Switzerland

NASA Astrophysics Data System (ADS)

Scheidhauer, M.; Dupuy, D.; Marillier, F.; Beres, M.

2003-04-01

For better understanding of geologic processes in complex lacustrine settings, detailed information on geologic features is required. In many cases, the 3D seismic method may be the only appropriate approach. The aim of this work is to develop an efficient very high-resolution 3D seismic reflection system for lake studies. In Lake Geneva, Switzerland, near the city of Lausanne, past high-resolution investigations revealed a complex fault zone, which was subsequently chosen for testing our new system of three 24-channel streamers and integrated differential GPS (dGPS) positioning. A survey, carried out in 9 days in August 2001, covered an area of 1500^om x 675^om and comprised 180 CMP lines sailed perpendicular to the fault strike always updip, since otherwise the asymmetric system would result in different stacks for opposite directions. Accurate navigation and shot spacing of 5^om is achieved with a specially developed navigation and shot-triggering software that uses differential GPS onboard and a reference base close to the lake shore. Hydrophone positions could be accurately (<^o0.5^om) calculated with the aid of three additional dGPS antennas mounted on rafts attached to the streamer tails. Towed at a distance of only 75^om behind the vessel, they allowed determination of possible feathering due to cross-line currents or small course variations. The multi-streamer system uses two retractable booms deployed on each side of the boat and rest on floats. They separate the two outer streamers from the one in the center by a distance of 7.5^om. Combined with a receiver spacing of 2.5^om, the bin dimension of the 3D data becomes 3.75^om in cross-line and 1.25^om in inline direction. Potential aliasing problems from steep reflectors up to 30^o within the fault zone motivated the use of a 15/15 cu. in. double-chamber bubble-canceling Mini G.I. air gun (operated at 80^obars and 1^om depth). Although its frequencies do not exceed 650^o Hz, it combines a penetration of non-aliased signal to depths of 400^om with a best vertical resolution of 1.15^om. The multi-streamer system allows acquisition of high quality data, which already after conventional 3D processing show particularly clear images of the fault zone and the overlying sediments in all directions. Prestack depth migration can further improve data quality and is more appropriate for subsequent geologic interpretation.

Omega-3 free fatty acids for the treatment of severe hypertriglyceridemia: the EpanoVa fOr Lowering Very high triglyceridEs (EVOLVE) trial.

PubMed

Kastelein, John J P; Maki, Kevin C; Susekov, Andrey; Ezhov, Marat; Nordestgaard, Borge G; Machielse, Ben N; Kling, Douglas; Davidson, Michael H

2014-01-01

Omega-3 fatty acids in free fatty acid form have enhanced bioavailability, and plasma levels are less influenced by food than for ethyl ester forms. The aim was to evaluate the safety and lipid-altering efficacy in subjects with severe hypertriglyceridemia of an investigational pharmaceutical omega-3 free fatty acid (OM3-FFA) containing eicosapentaenoic acid and docosahexaenoic acid. This was a multinational, double-blind, randomized, out-patient study. Men and women with triglycerides (TGs) ≥ 500 mg/dL, but <2000 mg/dL, took control (olive oil [OO] 4 g/d; n = 99), OM3-FFA 2 g/d (plus OO 2 g/d; n = 100), OM3-FFA 3 g/d (plus OO 1 g/d; n = 101), or OM3-FFA 4 g/d (n = 99) capsules for 12 weeks in combination with the National Cholesterol Education Program Therapeutic Lifestyle Changes diet. Fasting serum TGs changed from baseline by -25.9% (P < .01 vs OO), -25.5% (P < .01 vs OO), and -30.9% (P < .001 vs OO) with 2, 3, and 4 g/d OM3-FFA, respectively, compared with -4.3% with OO. Non-high-density lipoprotein cholesterol (non-HDL-C), total cholesterol-to-HDL-C ratio, very low-density lipoprotein cholesterol, remnant-like particle cholesterol, apolipoprotein CIII, lipoprotein-associated phospholipase A2, and arachidonic acid were significantly lowered (P < .05 at each OM3-FFA dosage vs OO); and plasma eicosapentaenoic acid and docosahexaenoic acid were significantly elevated (P < .001 at each OM3-FFA dosage vs OO). With OM3-FFA 2 and 4 g/d (but not 3 g/d), low-density lipoprotein cholesterol was significantly increased compared with OO (P < .05 vs OO). High-sensitivity C-reactive protein responses with OM3-FFA did not differ significantly from the OO response at any dosage. Fewer subjects reported any adverse event with OO vs OM3-FFA, but frequencies across dosage groups were similar. Discontinuation due to adverse event, primarily gastrointestinal, ranged from 5% to 7% across OM3-FFA dosage groups vs 0% for OO. OM3-FFA achieved the primary end point for TG lowering and secondary end point of non-HDL-C lowering at 2, 3, and 4 g/d in persons with severe hypertriglyceridemia. This trial was registered at www.clinicaltrials.gov as NCT01242527. Copyright © 2014 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Toughening mechanism in elastometer-modified epoxy resins: Part 1

NASA Technical Reports Server (NTRS)

Yee, A. F.; Pearson, R. A.

1983-01-01

Several plaques of Epon 828, cured with piperidine, modified with hycar(r) CTBN 1300X8, Hycar(R) CTBN 1300X13, and Hycar(R) CTBN 1300x15, and in some cases modified with biphenol A (BPA), yielded properly toughened epoxies with rubber particle diameters ranging from 0.1 to 10 microns. Fracture toughness experiments indicate that toughness was more a function of rubber content than the rubber particle size. Tensile volumetric behavior of the near resin exhibits two regions: an initial region where the increase in volume strain was due to the Poisson's effect, and a second region where a slower rate of increase in volume strain was due to shear deformation. Tensile volumetric deformation of an elastomer-modified epoxy exhibits the same type of behavior to that of the neat resin at low rates ( 3.2x0.01 sec(-1)). But at very high strain rates, which correspond more closely to the strain rates at the crack tip, there exists an increase in volume strain beyond the Poisson's effect. TEM, SEM and OM studies indicate that the rubber particles had voided. When a thin section from the deformed region is viewed under crossed-polarized light, shear bands are seen connecting voided rubber particles. From this information cavitation and enhanced shear band formation is proposed as the toughening mechanism.

Facilitating Successful Outdoor O&M Instruction of Multihandicapped Blind Travelers.

ERIC Educational Resources Information Center

Ehresman, Paul

1994-01-01

An orientation and mobility (O&M) instructor presents a case study of a blind 14 year old with mild cognitive deficits and emotional and behavioral problems. The case study demonstrates the importance of individualizing the O&M curriculum, including changing the usual sequence of instruction. (DB)

Operations and maintenance philosophy

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

DUNCAN, G.P.

1999-10-28

This Operations and Maintenance (O&M) Philosophy document is intended to establish a future O&M vision, with an increased focus on minimizing worker exposure, ensuring uninterrupted retrieval operations, and minimizing operation life-cycle cost. It is intended that this document would incorporate O&M lessons learned into on-going and future project upgrades.

Generating a Spanish Affective Dictionary with Supervised Learning Techniques

ERIC Educational Resources Information Center

Bermudez-Gonzalez, Daniel; Miranda-Jiménez, Sabino; García-Moreno, Raúl-Ulises; Calderón-Nepamuceno, Dora

2016-01-01

Nowadays, machine learning techniques are being used in several Natural Language Processing (NLP) tasks such as Opinion Mining (OM). OM is used to analyse and determine the affective orientation of texts. Usually, OM approaches use affective dictionaries in order to conduct sentiment analysis. These lexicons are labeled manually with affective…

OMS 1987 Annual Report.

ERIC Educational Resources Information Center

Association of Research Libraries, Washington, DC. Office of Management Studies.

Designed to serve both as an activity report on Office of Management Studies (OMS) progress during 1987 and a catalog of OMS services and products, this annual report focuses on the management of technology in a scholarly environment. Programs and services are reported in five sections: (1) Applied Research and Development (the Institute on…

Orbital maneuvering subsystem functional path analysis for performance monitoring fault detection and annunciation

NASA Technical Reports Server (NTRS)

Keesler, E. L.

1974-01-01

The functional paths of the Orbital Maneuver Subsystem (OMS) is defined. The operational flight instrumentation required for performance monitoring, fault detection, and annunciation is described. The OMS is a pressure fed rocket engine propulsion subsystem. One complete OMS shares each of the two auxiliary propulsion subsystem pods with a reaction control subsystem. Each OMS is composed of a pressurization system, a propellant tanking system, and a gimbaled rocket engine. The design, development, and operation of the system are explained. Diagrams of the system are provided.

Evaluation of OMNIgene®•SPUTUM for tuberculosis sample processing and liquid culture at a hospital laboratory in India.

PubMed

Nambiar, Remya; Shaw, Kaitlyn; Curry, Patricia S

2017-10-01

This preliminary evaluation examined the reagent OMNIgene®•SPUTUM (OM-S) as a tool to eliminate NaOH/NALC processing prior to Middlebrook liquid culture for Mycobacterium tuberculosis (MTb). Twenty-seven manually split samples (OM-S-treated vs. NaOH/NALC) showed 100% agreement: 81.5% MTb-positive and 18.5% MTb-negative. On average, OM-S-treated specimens required 1.2 additional days to culture positivity. Copyright © 2017 Elsevier B.V. All rights reserved.

Commercial Eyes in Space: Implications for U.S. Military Operations in 2030

DTIC Science & Technology

2008-03-01

r C om m er ci al Im ag er y C om pa ny Su bj ec t Figure 2: Notional Satellite Remote Sensing Flow and...Government will most likely continue to rely on commercial sensors to supplement national intelligence 14 A dv er sa ry U se r C om m er ci al Im ag er y...C om pa ny Su bj ec t Potential Counter ISR Strategies for 2030 Image Request Tasking Recv’d Satellite Tasked Image Processed & Stored

Morphology, composition, and mixing state of primary particles from combustion sources - crop residue, wood, and solid waste.

PubMed

Liu, Lei; Kong, Shaofei; Zhang, Yinxiao; Wang, Yuanyuan; Xu, Liang; Yan, Qin; Lingaswamy, A P; Shi, Zongbo; Lv, Senlin; Niu, Hongya; Shao, Longyi; Hu, Min; Zhang, Daizhou; Chen, Jianmin; Zhang, Xiaoye; Li, Weijun

2017-07-11

Morphology, composition, and mixing state of individual particles emitted from crop residue, wood, and solid waste combustion in a residential stove were analyzed using transmission electron microscopy (TEM). Our study showed that particles from crop residue and apple wood combustion were mainly organic matter (OM) in smoldering phase, whereas soot-OM internally mixed with K in flaming phase. Wild grass combustion in flaming phase released some Cl-rich-OM/soot particles and cardboard combustion released OM and S-rich particles. Interestingly, particles from hardwood (pear wood and bamboo) and softwood (cypress and pine wood) combustion were mainly soot and OM in the flaming phase, respectively. The combustion of foam boxes, rubber tires, and plastic bottles/bags in the flaming phase released large amounts of soot internally mixed with a small amount of OM, whereas the combustion of printed circuit boards and copper-core cables emitted large amounts of OM with Br-rich inclusions. In addition, the printed circuit board combustion released toxic metals containing Pb, Zn, Sn, and Sb. The results are important to document properties of primary particles from combustion sources, which can be used to trace the sources of ambient particles and to know their potential impacts in human health and radiative forcing in the air.

The impact of oral herpes simplex virus infection and candidiasis on chemotherapy-induced oral mucositis among patients with hematological malignancies.

PubMed

Chen, Y-K; Hou, H-A; Chow, J-M; Chen, Y-C; Hsueh, P-R; Tien, H-F

2011-06-01

The aim of this study was to evaluate the influences of oral candidiasis and herpes simplex virus 1 (HSV-1) infections in chemotherapy-induced oral mucositis (OM). The medical records of 424 consecutive patients with hematological malignancies who had received chemotherapy at a medical center in Taiwan from January 2006 to November 2007 were retrospectively reviewed. The results of swab cultures of fungus and HSV-1 for OM were correlated with associated clinical features. Younger age, myeloid malignancies, and disease status other than complete remission before chemotherapy were significantly correlated with the development of OM. Risks of fever (p < 0.001) and bacteremia were higher in patients with OM. Among 467 episodes of OM with both swab cultures available, 221 were non-infection (47.3%) and 246 were related to either fungal infections, HSV-1 infections, or both (52.7%); of the 246 episodes, 102 were associated with fungal infections alone (21.8%), 98 with HSV-1 infections alone (21%), and 46 with both infections (9.9%). Patients who had received antifungal agents prior to OM occurrence tended to have HSV-1 infection (p < 0.001). Our results suggest that Candida albicans and HSV-1 play an important role in chemotherapy-induced OM in patients with hematological malignancies.

OM-101 Decreases the Fibrotic Response Associated with Proliferative Vitreoretinopathy

PubMed Central

Dvashi, Zeev; Ben-Yaakov, Keren; Weinberg, Tamir; Greenwald, Yoel

2017-01-01

Purpose This study aimed to investigate the effect of OM-101 on the fibrotic response occurring in proliferative vitreoretinopathy (PVR) in an animal model. Methods Antifibrotic effect of OM-101 was investigated in vivo. As control, eight weeks old c57black mice underwent intravitreal injection with Hepes (group A) or dispase (0.3 units), to induce retinal detachment (RD) and PVR. The dispase-injected mice were randomly divided into two groups B and C (N = 25 mice); in group C, the eyes were treated with intravitreal injection of OM-101 (3 μl), and group B with PBS, as a control. After additional five days, mice were injected with the same initial treatment. Three days later, mice were euthanized, and the eyes were enucleated and processed for histological analysis. Results Intravitreal injection of dispase caused RD in 64% of the mice in group B, and 93% of those mice had PVR. Only 32% of mice treated with OM-101 and dispase (group C) developed RD, and only 25% of those developed PVR. Conclusions OM-101 was found effective in reducing the incidence of RD and PVR maintaining the normal architecture of the retina. This study suggests that OM-101 is a potentially effective and safe drug for the treatment of PVR patients. PMID:29109865

Using organic matter gradients to predict mercury cycling following environmental changes

NASA Astrophysics Data System (ADS)

Bjorn, E.; Bravo, A. G.; Jonsson, S.; Seelen, E.; Skrobonja, A.; Skyllberg, U.; Soerensen, A.; Zhu, W.

2017-12-01

The biogeochemical cycling of mercury (Hg) includes redox and methylation transformation reactions, largely mediated by microorganisms. These reactions are decisive for mobility and bioavailability of Hg in ecosystems. Organic matter (OM) plays several critical roles in these important transformation reactions. In many aquatic systems, the composition of OM is naturally diverse and dynamic, and subject to further alternations due to ecosystem changes induced by climate, eutrophication, land use, and industrial activities. We will present recent findings on how changing characteristics of OM along natural salinity and carbon gradients control Hg methylation and reduction reactions, as well as bioaccumulation processes. We will further discuss potential changes to Hg cycling, primarily in coastal seas, following ecosystem perturbations which alter the amount and characteristics of OM. The presentation will focus on recent research advancements describing how: (i) the binding of Hg to thiol functional groups in OM controls the chemical speciation of Hg, and thereby its availability for chemical reactions and uptake in biota, (ii) the composition of OM is a primary controlling factor for methylation and reduction rates of divalent Hg by electron donation and shuttling processes, (iii) the amount and characteristics of dissolved OM affect the structure and productivity of the pelagic food web, and thereby the biomagnification of methylmercury.

Effects of soil organic matter content on cadmium toxicity in Eisenia fetida: implications for the use of biomarkers and standard toxicity tests.

PubMed

Irizar, A; Rodríguez, M P; Izquierdo, A; Cancio, I; Marigómez, I; Soto, M

2015-01-01

Bioavailability is affected by soil physicochemical characteristics such as pH and organic matter (OM) content. In addition, OM constitutes the energy source of Eisenia fetida, a well established model species for soil toxicity assessment. The present work aimed at assessing the effects of changes in OM content on the toxicity of Cd in E. fetida through the measurement of neutral red uptake (NRU) and mortality, growth, and reproduction (Organisation for Economic Co-operation and Development [OECD] Nos. 207 and 222). Complementarily, metallothionein (MT) and catalase transcription levels were measured. To decrease variability inherent to natural soils, artificial soils (Organization for Economic Cooperation and Development 1984) with different OM content (6, 10, and 14%) and spiked with Cd solutions at increasing concentrations were used. Low OM in soil decreased soil ingestion and Cd bioaccumulation but also increased Cd toxicity causing lower NRU of coelomocytes, 100 % mortality, and stronger reproduction impairment, probably due to the lack of energy to maintain protection mechanisms (production of MT).Cd bioaccumulation did not reflect toxicity, and OM played a pivotal role in Cd toxicity. Thus, OM content should be taken into account when using E. fetida in in vivo exposures for soil health assessment.

Efficacy and safety of long-term treatment with the combination of amlodipine besylate and olmesartan medoxomil in patients with hypertension.

PubMed

Chrysant, Steven G; Oparil, Suzanne; Melino, Michael; Karki, Sulekha; Lee, James; Heyrman, Reinilde

2009-09-01

J Clin Hypertens (Greenwich). 2009;11:475-482. (c) 2009 Wiley Periodicals, Inc.The authors report on the 44-week open-label extension of the 8-week, double-blind Combination of Olmesartan Medoxomil and Amlodipine Besylate in Controlling High Blood Pressure (COACH) trial in 1684 patients. Initial therapy was amlodipine (AML) plus olmesartan medoxomil (OM) 5+40 mg/d, up-titrated to AML+OM 10+40 mg/d plus hydrochlorothiazide (HCTZ) 12.5 mg then 25 mg if patients did not achieve blood pressure (BP) goal (<140/90 mm Hg or <130/80 mm Hg in patients with diabetes). Baseline mean BP decreased from 164/102 mm Hg to 131/82 mm Hg at end of study, with an overall 66.7% of patients, including those with diabetes, achieving BP goal. The BP goal achievement was 80% for AML+OM 5+40 mg/d, 70.6% for AML+OM 10+40 mg/d, 66.6% for AML+OM+HCTZ 10+40+12.5 mg/d, and 46.3% for AML+OM+HCTZ 10+40+25 mg/d. Study medication was safe and well tolerated. Combination antihypertensive therapy with AML+OM+/-HTCZ, up-titrated as necessary, allowed a majority of patients to achieve BP goal.

The role of organic matter and clay content in sediments for bioavailability of pyrene.

PubMed

Spasojević, Jelena; Maletić, Snežana; Rončević, Srđan; Grgić, Marko; Krčmar, Dejan; Varga, Nataša; Dalmacija, Božo

2018-01-01

Evaluation of the bioavailable fractions of organic contaminants such as polycyclic aromatic hydrocarbons (PAHs) is extremely important for assessing their risk to the environment. This available fraction, which can be solubilised and/or easily extracted, is believed to be the most accessible for bioaccumulation, biosorption and/or transformation. Sediment organic matter (OM) and clay play an important role in the biodegradation and bioavailability of PAHs. The strong association of PAHs with OM and clay in sediments has a great influence not only on their distribution but also on their long-term environmental impact. This paper investigates correlations between bioavailability and the clay and OM contents in sediments. The results show that OM is a better sorbent for pyrene (chosen as a model PAH) and that increasing the OM content reduces the bioavailable fraction. A mathematical model was used to predict the kinetic desorption, and these results showed that the sediment with the lowest content of OM had an F fast value of 24%, whereas sediment with 20% OM gave a value of 9%. In the experiments with sediments with different clay contents, no clear dependence between clay and rate constants of the fast desorbing fractions was observed, which can be explained by the numerous possible interactions at the molecular level.

A High-Speed Optical Modem Communication System for CORK Seafloor Observatories

NASA Astrophysics Data System (ADS)

Farr, N.; Tivey, M.; Ware, J.; Pontbriand, C.; Pelletier, L. P.

2014-12-01

High-speed communications underwater is an increasing requirement for data intensive seafloor sensors. Acoustic modems provide dependable long-range communications underwater, but data rates are limited to <57Kbps. Free-water optical modems (OMs) offer high data rate, 10Mbps communications over a range of 200 m - a distance for ROVs, AUVs or wire-lowered packages to communicate without the need to directly plug-in or retrieve the instrument. Over the past 4 years, we have demonstrated the functionality and utility of OM technology using a CORK borehole observatory as a test case. A CORK represents all of the basic components required for a seafloor observatory: a stable environment for long-term continuous measurements of earth and ocean phenomena, access to a unique environment below the seafloor and a standard communication interface. The CORK-OM features a high-bandwidth, low-latency optical system based on LED emitters and PMT receivers and an acoustic command and control system. OM tests established a communication link from 20 to 200 meters range at rates of 1, 5 and 10 Mbps with no bit errors. The seafloor OM was plugged into the CORK's existing underwater wet mateable connector and provided additional power to the CORK to boost the data rate to 1 Hz from the normal 1 minute sample period. To communicate with the seafloor CORK-OM, a number of different modalities were used. One method was an OM mounted to a CTD frame on a lowered wire from a ship with an SDSL link over the conducting wire. Other methods utilized OMs mounted to both ROV Jason and submersible Alvin. We deployed OMs at two CORKs in 2012 in the northeast pacific at sites 857D and 1025C. The CORKs were visited in 2013 by a vessel of opportunity to download data and were put into sleep mode. The CORKs were revisited in 2014, woken up and successfully interrogated for data. ALVIN retrieved the CORK-OMs for corrosion, biofouling and battery performance assessment. We also performed tests of a next generation OM using a deployed seafloor modem and AUV Sentry. A complete lambertian optical field was quantitatively mapped by Sentry and test data was successfully downloaded from 20 to 150 m slant range. The AUV modality demonstrates the capability of 'data-mule' operations to autonomously recover data from a seafloor observatory with minimal human intervention.

A D- and N-15-Rich Micrometer-Sized Aggregate of Organic Matter in a Xenolithic Clast from the Zag Ordinary Chondrite

NASA Technical Reports Server (NTRS)

Kebukawa, Yoko; Ito, Motoo; Zolensky, Michael E.; Rahman, Zia; Suga, Hiroki; Nakato, Aiko; Chan, Queenie H. S.; Fries, Marc; Takeichi, Yasuo; Takahashi, Yoshio;

Energy transfer in the Congo deep-sea fan: From terrestrially-derived organic matter to chemosynthetic food webs

NASA Astrophysics Data System (ADS)

Pruski, A. M.; Decker, C.; Stetten, E.; Vétion, G.; Martinez, P.; Charlier, K.; Senyarich, C.; Olu, K.

2017-08-01

Large amounts of recent terrestrial organic matter (OM) from the African continent are delivered to the abyssal plain by turbidity currents and accumulate in the Congo deep-sea fan. In the recent lobe complex, large clusters of vesicomyid bivalves are found all along the active channel in areas of reduced sediment. These soft-sediment communities resemble those fuelled by chemoautotrophy in cold-seep settings. The aim of this study was to elucidate feeding strategies in these macrofaunal assemblages as part of a greater effort to understand the link between the inputs of terrestrially-derived OM and the chemosynthetic habitats. The biochemical composition of the sedimentary OM was first analysed in order to evaluate how nutritious the available particulate OM is for the benthic macrofauna. The terrestrial OM is already degraded when it reaches the final depositional area. However, high biopolymeric carbon contents (proteins, carbohydrates and lipids) are found in the channel of the recent lobe complex. In addition, about one to two thirds of the nitrogen can be assigned to peptide-like material. Even if this soil-derived OM is poorly digestible, turbiditic deposits contain such high amounts of organic carbon that there is enough biopolymeric carbon and proteacinous nitrogen to support dense benthic communities that contrast with the usual depauperate abyssal plains. Stable carbon and nitrogen isotopes and fatty acid biomarkers were then used to shed light on the feeding strategies allowing the energy transfer from the terrestrial OM brought by the turbidity currents to the abyssal food web. In the non-reduced sediment, surface detritivorous holothurians and suspension-feeding poriferans rely on detritic OM, thereby depending directly on the turbiditic deposits. The sulphur-oxidising symbiont bearing vesicomyids closely depend on the reprocessing of OM with methane and sulphide as final products. Their carbon and nitrogen isotopic signatures vary greatly among sites and could reflect the intensity of the anaerobic oxidation of methane (AOM) in the sediments. Within the vesicomyid habitats, the heterotrophic fauna exhibits a distinctively light carbon isotopic signature in comparison to the background sediments, clearly indicating the utilisation of chemosynthetically-derived OM. Fatty acid biomarkers further confirm that dorvilleid polychaetes consume aggregates that perform AOM. Terrestrial OM reprocessing by microbial consortium thus ensures its transfer to the benthic food web in the Congo deep-sea fan.

Towards explaining excess CO2 production in wetlands - the roles of solid and dissolved organic matter as electron acceptors and of substrate quality

NASA Astrophysics Data System (ADS)

Knorr, Klaus-Holger; Gao, Chuanyu; Agethen, Svenja; Sander, Michael

2017-04-01

To understand carbon storage in water logged, anaerobic peatlands, factors controlling mineralization have been studied for decades. Temperature, substrate quality, water table position and the availability of electron acceptors for oxidation of organic carbon have been identified as major factors. However, many studies reported an excess carbon dioxide (CO2) production over methane (CH4) that cannot be explained by available electron acceptors, and peat soils did not reach strictly methanogenic conditions (i.e., a stoichiometric formation ratio of 1:1 of CO2 to CH4). It has been hypothesized that peat organic matter (OM) provides a previously unrecognized electron acceptor for microbial respiration, elevating CO2 to CH4 ratios. Microbial reduction of dissolved OM has been shown in the mid 90's, but only recently mediated electrochemical techniques opened the possibility to access stocks and changes in electron accepting capacities (EAC) of OM in dissolved and solid form. While it was shown that the EAC of OM follows redox cycles of microbial reduction and O2 reoxidation, changes in the EAC of OM were so far not related quantitatively to CO2 production. We therefore tested if CO2 production in anoxic peat incubations is balanced by the consumption of electron acceptors if EAC of OM is included. We set up anoxic incubations with peat and monitored production of CO2 and CH4, and changes in EAC of OM in the dissolved and solid phase over time. Interestingly, in all incubations, the EAC of dissolved OM was poorly related to CO2 and CH4 production. Instead, dissolved OM was rapidly reduced at the onset of the incubations and thereafter remained in reduced form. In contrast, the decrease in the EAC of particulate (i.e. non-dissolved) OM was closely linked to the observed production of non-methanogenic CO2. Thereby, the total EAC of the solid OM pool by far exceeded the EAC of the dissolved OM pool. Over the course of eight week incubations, measured decreases in the EAC of total NOM could explain 22-38 % of excess CO2 production in a weakly decomposed peat, 30-67 % of excess CO2 production in a well decomposed peat, and >100 % of excess CO2 production in a peat that had been exposed to oxygen for > 1 year. In this latter peat, EAC by OM explained 45-57 % of CO2 production, while reduction of sulfate available in this material readily explained the remaining fraction. Despite having considerable uncertainty arising from methodological challenges, the collected data demonstrated that accounting for the EACs of solid and dissolved OM may fully explain excess CO2 production. As we conservatively assumed a carbon oxidation state of zero for our budget calculations, a higher oxidation state of C in NOM as suggested by elemental analysis would result in electron equivalent budgets between EAC decreases and CO2 formation even closer to 100 %. A higher oxidation state of mineralized carbon seemed especially likely for weakly decomposed peat, as this material had higher concentrations of oxygen and showed the largest percentage of formed CO2 that could not be explained based on OM reduction.

Nanoscale Structure Of Organic Matter Explain Its Recalcitrance To Degradation

NASA Astrophysics Data System (ADS)

Spagnol, M.; Salati, S.; Papa, G.; Tambone, F.; Adani, F.

2009-04-01

Recalcitrance can be defined as the natural resistance of organic matter (OM) to microbial and enzymatic deconstruction (Himmel et al., 2007). The nature of OM recalcitrance remained not completely understood and more studies need above all to elucidate the role of the chemical topography of the OM at nanometer scale. Hydrolytic enzymes responsible of OM degradation have a molecular weight of 20-25 kD, corresponding to a size of about 4 nm, hardly penetrate into micropores (i.e. the pore having a diameter < 2 nm) and small mesopores (i.e. pores having a diameter 2 < 50 nm) of OM structures, so that their activities are confined only to a portion of the total surface (Zimmerman et al., 2004; Chesson, 1997; Adani et al., 2006). As consequence of that the characterization of the organic matter at nano-scale became interesting in view to explain OM recalcitrance. The aim of this work was to asses the effect of the nano-scale structure of OM versus its recalcitrance. The evolution of organic matter of organic matrices was studied in two systems: plant residue-soil system and simulated landfill system. Plant residues were incubated in soil for one year and recalcitrant fraction, i.e. humic acid, was isolated and studied. Laboratory simulated landfill considered organic fraction of municipal solid waste sampled at different stages of evolution from a full scale plant and incubated under anaerobic condition for one year. In addition the nano-scale structure of fossilized OM (leonardite, chair coal and graphite) was detected as used as model of recalcitrant OM. Nano-scale structures were detected by using meso and microporosity detection. In particular microporosity was determined by adsorption method using CO2 at 273 K and Non Local Density Functional Theory (NLDFT) method was applied to measure the CO2 adsorption isotherms. On the other hand mesoporosity was detected by using N2 adsorption method at 77 K. The BET (Brunauer-Emmett-Teller) equation and the BJH (Barret-Joyner-Halenda) equation were applied respectively to measure specific surface area and mesoporosity. Macromolecular composition of OM was investigated by using CP MAS 13NMR and wet chemical analyses. Results obtained showed how OM evolved increasing microporosity and decreasing meso porosity. This was the result of the preservation of recalcitrant OM versus degradation of the more labile fraction, suggesting that the more recalcitrant fraction was characterized by high microporosity. Another confirmation of these results comes from the analysis of the same OM after the removing of the labile fraction by acid hydrolysis to discover the core-OM, which was characterized by a higher microposrosity with respect the bulk OM. In conclusion it can be showed that not only the chemical composition but, also, the physical structure of organic matter defined its recalcitrance. References Adani, F.; Spagnol, M.; Genevini, P. Biogeochemistry 2006, 78, 85-96. Himmel, M.E.; Ding S.Y.; Johnson, D.K.; Adney, W.S.; Nimlos, M.R.; Brady, J.W.; Foust, T.D. Sci. 2007, 315, 804-807. Chesson, A. In Driven by nature Plant Litter Quality and Decomposition. Cadisch, G.; Giller, K.E. Eds.; CAB International: Wallinford, UK 1997, pp 47-66. Zimmerman, A.R.; Goyne, K.W.; Chorover, J, Komarneni, S.; Brantley, S.L. Org Geochem. 2004, 35, 355-375.

Temperature & wood source control PyOM turnover in a Northern American forest

NASA Astrophysics Data System (ADS)

Hatton, Pierre-Joseph; Le Moine, James; Auclerc, Apolline; Gormley, Mark; Filley, Tim R.; Nadelhoffer, Knute J.; Bird, Jeff. A.

2016-04-01

Surprisingly little is known about how pyrolysis temperature and wood source affect the stability of forest-fire derived pyrogenic organic matter (PyOM). Here, we show that wood source and temperature affect in situ mineralization rates of PyOM in soils for two co-occurring gymnosperm (jack pine; JP [Pinus banksiana]) and angiosperm (red maple; RM [Acer rubrum])¬ species from North American boreal-temperate ecotones. We assess the effect of pyrolysis temperature on PyOM fates by following the decay of 13C/15N-enriched JP wood (JPwood) and PyOM produced at 300 °C (JP300) and 450 °C (JP450); and assess the effect of PyOM wood source by comparing fates of JP450 and RM450. JPwood mineralized 18× faster than JP300 and 44× faster than JP450 after 2.8y. RM450 mineralized initially faster than JP450 during the first ~2y, but became equivalent afterwards (1.1±0.2% of CO¬2 losses after 2.8y). Modeled turnover times suggest that this can be attributed to ~1% of fast-cycling PyOM (<3y). Slower-cycling pools are 12× faster for JPwood (13±5y) than for JP300 (157±28y) and 55× faster than for JP450 (700±229y). Modeled turnover times of the slow-cycling pools were equivalent for JP450 and RM450. The priming effect was positive for JPwood (0.10±0.05), neutral for JP300 (-0.02±0.04), and negative for JP450 (-0.15±0.03) and RM50 (-0.59±0.03). DOC losses were minimal compared with CO2 losses (DOC:CO2 ratio ≤0.005), but followed the same patterns: JPwood 6× greater than that of JP300 and 39× greater compared with JP450. After 1y, C recoveries were lower for JPwood than for PyOM, with no influence of pyrolysis temperature or wood source (yet); N recoveries did not differ. PLFA-(13)C data reveal that (i) treatments have similar microbial communities after 1y, (ii) JPwood is preferentially utilized by fungi, and (iii) bacteria increasingly utilize PyOM as pyrolysis temperature increases. Estimated carbon use efficiency decreased with increasing pyrolysis temperature (JPwood~JP300>JP450~RM450). Although insignificant, potential phenol oxidase and peroxidase activities decrease with increasing pyrolysis temperature. Neither PyOM nor wood additions (~11% of soil C stock 0-20 cm depth) affected pH or Ec after 1y. We provide the first, field experimental evidence that pyrolysis temperature and wood source affect the turnover of PyOM in soil. We show faster, initial decay for PyOM produced at lesser temperature and RM (angiosperm) compared with JP (gymnosperm). This study offers realistic insights on (i) the controls underlying in situ PyOM turnover, and on (ii) how ongoing/projected changes in tree species composition and fire frequency/intensity/distribution may affect PyOM in soil of North America temperate-boreal ecotones.

Source of the Organic Matter and Land-Marine Interaction Phases in Great Rann of Kachch Basin, India

NASA Astrophysics Data System (ADS)

Khonde, N. N.; Bhushan, R.; Agnihotri, R.; Maurya, D. M.; Chamyal, L. S.

2017-12-01

Using δ13C and C/N ratio of sedimentary organic matter (OM) in 14C AMS dated sediment core from central Great Rann of Kachchh (GRK) basin, we track sediment dispositional history since 18 ka BP. Temporal changes in the δ13C and C/N ratios were inferred in terms of OM source, which could be function of river discharge, relative sea level changes, and also due to land-cover changes in the catchment area. The down core variations in TOC vs TC doesn't show significant correlation suggesting diverse origin of the OM in GRK sediments. Between 18-13 ka BP, pulses of high C/N ratio (18-34) and depleted δ13C (average -23‰; with respect to typical marine -21‰) values hint terrestrially derived OM in rather overall marine environment. High terrestrial OM input from riverine inputs in post glacial period could be relatable to intense monsoonal conditions. Later to this phase, between 14-10 ka BP, C/N ratios show large fluctuations indicating rapidly fluctuating environment, albeit δ13C remains relatively stable at -21‰ typical of marine OM. A significant positive incursion in C/N ratio (45-60) is seen during early-mid Holocene time ( 10-6 ka BP) with and highly depleted δ13C ( -25‰) values indicating enhanced terrestrial OM input. This could be owing to increased riverine fluxes to the basin under intensified monsoonal climate. Between 6-2.5 ka BP during mid-Holocene, C/N ratios shows declining trend with enriched δ13C values, suggesting presence of marine OM source at the core-site. This overlaps with the weaker monsoonal conditions prevailing in the northwest India. Lake records from Rajasthan also support this contention. After 2.5 ka BP, C/N ratios indicate marine OM values, whereas δ13C fluctuates from marine to terrestrial values indicating `mixed-source' of the OM during this period, most likely due to unstable land-marine conditions and large-scale reworking of sediments.

Near-elimination of otitis media caused by 13-valent pneumococcal conjugate vaccine (PCV) serotypes in southern Israel shortly after sequential introduction of 7-valent/13-valent PCV.

PubMed

Ben-Shimol, Shalom; Givon-Lavi, Noga; Leibovitz, Eugene; Raiz, Simon; Greenberg, David; Dagan, Ron

2014-12-15

Otitis media (OM) is common in early childhood. Streptococcus pneumoniae caused approximately 30%-60% of episodes before the pneumococcal conjugate vaccine (PCV) era. The 7-valent PCV (PCV7) was introduced to the Israeli National Immunization Plan in July 2009, and was gradually replaced by the 13-valent PCV (PCV13) starting in November 2010. We aimed at assessing the impact of PCV7/PCV13 sequential introduction on pneumococcal and overall OM necessitating middle ear fluid culture in children aged <2 years in southern Israel. This was a prospective, population-based, active surveillance. Our medical center is the only one in the region, enabling incidence calculation. All pneumococcal episodes submitted for culture between July 2004 and June 2013 were included. Three subperiods were defined: pre-PCV, PCV7, and PCV13. Overall, 6122 OM episodes were recorded, and 1893 were pneumococcal. Compared with the pre-PCV period, OM caused by PCV7 plus serotype 6A and the 5 additional PCV13 serotypes (5VT : 1, 3, 5, 7F, 19A) decreased by 96% and 85%, respectively (incidence rate ratios [IRRs], 0.04 [95% confidence interval {CI}, .02-.08] and 0.15 [95% CI, .07-.30], respectively) in a 2-step pattern: In the PCV7 period, only OM caused by PCV7 + 6A serotypes was decreased; in the PCV13 period, 5VT OM rates decreased, along with an additional PCV7 + 6A OM reduction. A nonsignificant increase in non-PCV13 serotype OM was observed (IRR, 1.07 [95% CI, .72-1.58]). In total, 77% and 60% reductions of all-pneumococcal and all-cause OM incidences, respectively, were observed. A substantial 2-step reduction of pneumococcal OM rates, with near-elimination of PCV13 disease, was observed shortly after PCV7/PCV13 introduction. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

From hilltop to kettle hole: what trends across the terrestrial-aquatic transition zone are revealed by organic matter stable isotope (δ13C and δ15N) composition?

NASA Astrophysics Data System (ADS)

Kayler, Z. E.; Nitzsche, K. N.; Gessler, A.; Kaiser, M. L.; Hoffmann, C.; Premke, K.; Ellerbrock, R.

2016-12-01

Steep environmental gradients develop across the interface between terrestrial and aquatic domains that influence organic matter (OM) retention. In NE Germany, kettle holes are small water bodies found in high density across managed landscapes. Kettle hole water budgets are generally fed through precipitation and overland flow and are temporarily connected to groundwater resulting in distinct hydroperiods. We took advantage of the range of environmental conditions created by the fluctuating shoreline to investigate patterns of OM stability along transects spanning from hilltops to sediments within a single kettle hole. We physically and chemically separated OM fractions that are expected to be loosely bound, such as particulate organic matter, to those that are tightly bound, such as OM associated with mineral or metal surfaces. The study design allowed us to investigate stabilization processes at the aggregate, transect, and kettle hole catchment scale. At the aggregate scale, we analyzed soil characteristics (texture, pH, extractable Al, Fe, Ca) to contribute to our understanding of OM stabilization. At the transect scale, we compared isotopic trends in the different fractions against a simple Rayleigh distillation model to infer disruption of the transfer of material, for example erosion, by land management such as tillage or the addition of OM through fertilization. At the kettle hole catchment scale, we correlated our findings with plant productivity, landform properties, and soil wetness proxies. Aggregate scale patterns of OM 13C and 15N were fraction dependent; however, we observed a convergence in isotopic patterns with soil properties from OM of more stabilized fractions. At the transect scale, loosely bound fractions did not conform to the simple model, suggesting these fractions are more dynamic and influenced by land management. The stabilized fractions did follow the Rayleigh model, which implies that transfer processes play a larger role in these fractions. At the kettle hole catchment scale, we found that the terrestrial-aquatic transition zone and other areas with high soil moisture correlated with isotopic patterns of the OM fractions. Kettle hole sediment OM fraction patterns were consistently different despite receiving substantial material from the surrounding landscape.

Sources and atmospheric processing of size segregated aerosol particles revealed by stable carbon isotope ratios and chemical speciation.

PubMed

Masalaite, A; Holzinger, R; Ceburnis, D; Remeikis, V; Ulevičius, V; Röckmann, T; Dusek, U

2018-05-07

Size-segregated aerosol particles were collected during winter sampling campaigns at a coastal (55°37' N, 21°03'E) and an urban (54°64' N, 25°18' E) site. Organic compounds were thermally desorbed from the samples at different temperature steps ranging from 100 °C to 350 °C. The organic matter (OM) desorbed at each temperature step is analysed for stable carbon isotopes using an isotope ratio mass spectrometer (IRMS) and for individual organic compounds using a Proton Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-MS). The OM desorbed at temperatures <200 °C was classified as less refractory carbon and the OM desorbed at temperatures between 200 °C and 350 °C was classified as more refractory carbon. At the coastal site, we identified two distinct time periods. The first period was more frequently influenced by marine air masses than the second time period, which was characterized by Easterly wind directions and continental air masses. During the first period OM contained a large fraction of hydrocarbons and had a carbon isotopic signature typical of liquid fossil fuels in the region. Organic mass spectra provide strong evidence that shipping emissions are a significant source of OM at this coastal site. The isotopic and chemical composition of OM during the second period at the coastal site was similar to the composition at the urban site. There was a clear distinction in source contribution between the less refractory OM and the more refractory OM at these sites. According to the source apportionment method used in this study, we were able to identify fossil fuel burning as predominant source of the less refractory OM in the smallest particles (D 50  < 0.18 μm), and biomass burning as predominant source of the more refractory OM in the larger size range (0.32 < D 50  < 1 μm). Copyright © 2018 Elsevier Ltd. All rights reserved.

Sorting of Terrestrial and Marine Organic Matter along a Marginal Submarine Canyon: Radiocarbon and Biomarker Signatures of Surface Sediments

NASA Astrophysics Data System (ADS)

Close, H. G.; Doherty, S.; Campbell, P.; McCarthy, M. D.; Prouty, N.

2016-02-01

Submarine canyons are incised features of many continental margins that can have significant influence on the hydrodynamic distribution of sediments and organic matter (OM) eroded and deposited from the continents. Baltimore Canyon, on the U.S. mid-Atlantic margin, contains a complex set of sedimentary processes that simultaneously create unique benthic habitats and control the deposition of OM. Along the canyon axis, loci of net erosion, net deposition, and intense winnowing each host diverse faunal assemblages and varying mixtures of sedimentary OM derived both from production in the overlying water column and from mobilized sediments. Bioavailable components of this deposited OM sustain benthic communities, while recalcitrant components can contribute to long-term carbon burial in the deep sea. Here we probe in detail the terrestrial versus marine origins of OM along a transect of Baltimore Canyon, as well as its bioavailability for benthic fauna, in order to explore how canyon-specific sediment dynamics might emplace a functional sorting of OM from shelf to open ocean. Determining the provenance of sedimentary OM is a continual challenge: commonly-measured bulk geochemical properties often provide insufficient information to distinguish end-member sources. We present a novel approach to separate functional classes of OM and investigate sources and degradative pathways of OM in Baltimore Canyon. In combination with bulk geochemical characteristics, surface sediments from water depths of 200-1200 meters were sequentially extracted (solvent-extracted, acid-hydrolyzed, and demineralized) to separate pools containing different prevalence of terrigenous, marine, and recalcitrant OM. Each class was analyzed for biomarker distributions; amino acid content, 13C signatures, and degradation indicators; bulk carbon and nitrogen isotopes; and radiocarbon content in order to characterize potential end-member sources within the mixture, as well as their age profiles. These geochemical properties were contextualized with accompanying sedimentological and ecological data. Results highlight the importance of coastal proximity, canyon morphology, and local hydrodynamics in determining the bioavailability of benthic organic matter and its potential for long-term carbon burial.

Effects of management and pore characteristics on organic matter composition of macroaggregates: evidence from characterization of organic matter and imaging: Pore characteristics and OM composition of macroaggregates

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

Toosi, E. R.; Kravchenko, A. N.; Mao, J.

Macroaggregates are of interest because of their fast response to land management and their role in the loss or restoration of soil organic carbon (SOC). The study included two experiments. In Experiment I, we investigated the effect of long-term (27 years) land management on the chemical composition of organic matter (OM) of macroaggregates. Macroaggregates were sampled from topsoil under conventional cropping, cover cropping and natural succession systems. The OM of macroaggregates from conventional cropping was more decomposed than that of cover cropping and especially natural succession, based on larger δ 15N values and decomposition indices determined by multiple magic-angle spinningmore » nuclear magnetic resonance ( 13C CP/MAS NMR) and Fourier transform infrared (FTIR) spectroscopy. Previous research at the sites studied suggested that this was mainly because of reduced diversity and activity of the decomposer community, change in nutrient stoichiometry from fertilization and contrasting formation pathways of macroaggregates in conventional cropping compared with cover cropping and, specifically, natural succession. In Experiment II, we investigated the relation between OM composition and pore characteristics of macroaggregates. Macroaggregates from the natural succession system only were studied. We determined 3-D pore-size distribution of macroaggregates with X-ray microtomography, for which we cut the macroaggregates into sections that had contrasting dominant pore sizes. Then, we characterized the OM of macroaggregate sections with FTIR and δ15N methods. The results showed that within a macroaggregate, the OM was less decomposed in areas where the small (13–32 µm) or large (136–260 µm) pores were abundant. This was attributed to the role of large pores in supplying fresh OM and small pores in the effective protection of OM in macroaggregates. Previous research at the site studied had shown increased abundance of large and small intra-aggregate pores following adoption of less intensive management systems. It appears that land management can alter the OM composition of macroaggregates, partly by the regulation of OM turnover at the intra-aggregate scale.« less

Hospitalisation with otitis media in early childhood and cognitive function in young adult life: a prevalence study among Danish conscripts

PubMed Central

2013-01-01

Background Otitis media (OM) is a very common condition in children and occurs during years that are critical to the development of learning, literacy, and math skills. Therefore, among a large cohort of Danish conscripts, we aimed to examine the association between hospitalisation with OM in early childhood and cognitive function and educational level in early adulthood. Methods We conducted a population-based prevalence study using linked data from healthcare databases and conscription records of Danish men born between 1977 and 1983. We identified all hospitalisations with OM before 8 years of age. Cognitive function was measured by the Boerge Prien validated group intelligence test (Danish Børge Prien Prøve, BPP). We adjusted for potential confounders with and without stratification by hearing impairment. Furthermore, we examined the association between hospitalisation with OM and the prevalence of having achieved a General Certificate of Secondary Education (GCSE), stratified by quartiles of BPP scores. Results Of the 18 412 eligible conscripts aged 18–25 years, 1000 (5.5%) had been hospitalised with OM before age 8. Compared with conscripts without such a record, the adjusted prevalence ratio (PR) for a BPP score in the bottom quartile was 1.20 (95% confidence interval [CI]: 1.09–1.33). There was no major difference in the proportion of men with a GCSE and those without among those hospitalised with OM in early childhood. For men in the bottom and upper quartiles of BPP scores, the PRs for early childhood hospitalisation with OM were 0.89 (95% CI: 0.59–1.33) and 0.96 (95% CI, 0.88–1.05), respectively. Among men with severe hearing impairment, the proportion with a BPP score in the bottom quartile did not differ between those with and without an OM hospitalisation [PR = 1.01 (95% CI: 0.78–1.34)]. Conclusions Overall, we found that hospitalisation with OM in early childhood was associated with a slightly lower cognitive function in early adulthood. Hospitalisation for OM did not seem to influence the prevalence of GSCE when level of BPP was taken into account. PMID:23320411

Association of outdoor air pollution and indoor renovation with early childhood ear infection in China.

PubMed

Deng, Qihong; Lu, Chan; Jiang, Wei; Zhao, Jinping; Deng, Linjing; Xiang, Yuguang

2017-02-01

Otitis media (OM) is a common infection in early childhood with repeated attacks that lead to long-term complications and sequelae, but its risk factors still remain unclear. To examine the risk of childhood OM for different indoor and outdoor air pollutants during different timing windows, with a purpose to identify critical windows of exposure and key components of air pollution in the development of OM. We conducted a retrospective cohort study of 1617 children aged 3-4 years in Changsha, China (2011-2012). Children's life-time prevalence of OM and exposure to indoor air pollution related to home renovation activities were surveyed by a questionnaire administered by the parents. Children's exposure to outdoor air pollution, including nitrogen dioxide (NO 2 ), sulfur dioxide (SO 2 ), and particulate matter with an aerodynamic diameter ≤ 10 μm (PM 10 ), was estimated using the measured concentrations at municipal monitoring stations. The odds ratio (OR) and 95% confidence interval (CI) of childhood OM for prenatal and postnatal exposure to indoor and outdoor air pollution were examined by using logistic regression model. Life-time prevalence of OM in preschool children (7.3%) was associated not only with prenatal exposure to industrial air pollutant with adjusted OR (95% CI) = 1.44 (1.09-1.88) for a 27 μg/m 3 increase in SO 2 but also with postnatal exposure to indoor renovations with OR (95% CI) = 1.62 (1.05-2.49) for new furniture and 1.81 (1.12-2.91) for redecoration, particularly in girls. Combined exposure to outdoor SO 2 and indoor renovation significantly increased OM risk. Furthermore, we found that exposure to outdoor SO 2 and indoor renovation were significantly associated with the onset but not repeated attacks of OM. Prenatal exposure to outdoor industrial air pollution and postnatal exposure to indoor renovation are independently associated with early childhood OM in China and may cause the OM onset. Copyright © 2016 Elsevier Ltd. All rights reserved.

Oral and Maxillofacial Surgery Foundation Research and Fellowship Awards: A 26-Year Review at Massachusetts General Hospital and Harvard School of Dental Medicine.

PubMed

Inverso, Gino; Chuang, Sung-Kiang; Kaban, Leonard B

2016-02-01

The purpose of this study was to review outcomes of the Oral and Maxillofacial Surgery (OMS) Foundation's funding awards to members of the OMS department at Massachusetts General Hospital (MGH) in terms of projects completed, abstracts presented, peer-reviewed publications, and career trajectories of recipients. Data were collected from MGH and OMS Foundation records and interviews with award recipients. Primary outcome variables included 1) number of awards and award types, 2) funding amount, 3) project completion, 4) number of presented abstracts, 5) conversion from abstracts to publications, 6) number of peer-reviewed publications, 7) career trajectories of awardees, and 8) additional extramural funding. Eleven Student Research Training Awards provided $135,000 for 39 projects conducted by 37 students. Of these, 34 (87.2%) were completed. There were 30 student abstracts presented, 21 peer-reviewed publications, and a publication conversion rate of 58.8%. Faculty research awards comprised $1,510,970 for 22 research projects by 12 faculty members and two research fellows. Of the 22 funded projects, 21 (95.5%) were completed. There were 110 faculty and research fellow abstracts presented and 113 peer-reviewed publications, for a publication conversion rate of 93.8%. In the student group, 17 of 37 (45.9%) are enrolled in or are applying for OMS residencies. Of the 10 students who have completed OMS training, 3 (30%) are in full-time academic positions. Of the 12 faculty recipients, 9 (75%) remain in OMS academic practice. During this time period, the department received $9.9 million of extramural foundation or National Institutes of Health funding directly or indirectly related to the OMS Foundation grants. The results of this study indicate that 90.2% of projects funded by the OMS Foundation have been completed. Most projects resulted in abstracts and publications in peer-reviewed journals. These grants encouraged students to pursue OMS careers and aided OMS faculty in developing their research programs. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Ordered micro/macro porous K-OMS-2/SiO2 nanocatalysts: Facile synthesis, low cost and high catalytic activity for diesel soot combustion

PubMed Central

Yu, Xuehua; Zhao, Zhen; Wei, Yuechang; Liu, Jian

2017-01-01

A series of novel oxide catalysts, which contain three-dimensionally ordered macroporous (3DOM) and microporous structure, were firstly designed and successfully synthesized by simple method. In the as-prepared catalysts, 3DOM SiO2 is used as support and microporous K-OMS-2 oxide nanoparticles are supported on the wall of SiO2. 3DOM K-OMS-2/SiO2 oxide catalysts were firstly used in soot particle oxidation reaction and they show very high catalytic activities. The high activities of K-OMS-2/SiO2 oxide catalysts can be assigned to three possible reasons: macroporous effect of 3DOM structure for improving contact between soot and catalyst, microporous effect of K-OMS-2 for adsorption of small gas molecules and interaction of K and Mn for activation of gas molecules. The catalytic activities of catalysts are comparable to or even higher than noble metal catalyst in the medium and high temperature range. For example, the T50 of K-OMS-2/SiO2-50, 328 °C, is much lower than those of Pt/Al2O3 and 3DOM Au/LaFeO3, 464 and 356 °C,respectively. Moreover, catalysts exhibited high catalytic stability. It is attributed to that the K+ ions are introduced into the microporous structure of OMS-2 and stabilized in the catalytic reaction. Meanwhile, the K+ ions play an important role in templating and stabilizing the tunneled framework of OMS-2. PMID:28443610

Otitis media with effusion after radiotherapy of the head and neck: a systematic review.

PubMed

Christensen, J G; Wessel, I; Gothelf, A B; Homøe, P

2018-04-26

Otitis media (OM) and associated hearing problems may be side effects to radiotherapy of the head and neck region and affect patient quality of life. The condition is associated with the tumor location. To perform a systematic review concerning the present knowledge of the risk of OM after radiotherapy of the head and neck. A comprehensive search of PubMed and Embase was carried out between 1 October 2015 and 6 February 2017. The search strategy followed the PRISMA guideline for systematic reviews. Of 597 articles 11 fulfilled the inclusion criteria. Seven were retrospective and four prospective. There were no randomized controlled trials. Eight studies concerned nasopharyngeal cancer. One study concerned cancer of the parotid gland and two studies concerned other locations of head and neck cancer. Meta-analysis could not be done due to heterogeneity between the studies. The incidence of OM varied considerably (range 8-29%). The incidence of OM is high after radiotherapy of cancer of the upper head and neck area and the Eustachian tube (ET) irradiation dosage seems associated with development of OM, but the literature is poor. Research is needed to designate patients at risk of developing OM after radiotherapy. Preferably through analysis of dosage relationships between the ET and middle ear, and development of OM. Reporting of OM should be per ear and follow standardized protocols of middle ear assessment before and after radiotherapy. Furthermore, there is a need to find new ways to prevent and treat radiation-induced OME, preferably through randomized controlled trials.

Text mining-based in silico drug discovery in oral mucositis caused by high-dose cancer therapy.

PubMed

Kirk, Jon; Shah, Nirav; Noll, Braxton; Stevens, Craig B; Lawler, Marshall; Mougeot, Farah B; Mougeot, Jean-Luc C

2018-08-01

Oral mucositis (OM) is a major dose-limiting side effect of chemotherapy and radiation used in cancer treatment. Due to the complex nature of OM, currently available drug-based treatments are of limited efficacy. Our objectives were (i) to determine genes and molecular pathways associated with OM and wound healing using computational tools and publicly available data and (ii) to identify drugs formulated for topical use targeting the relevant OM molecular pathways. OM and wound healing-associated genes were determined by text mining, and the intersection of the two gene sets was selected for gene ontology analysis using the GeneCodis program. Protein interaction network analysis was performed using STRING-db. Enriched gene sets belonging to the identified pathways were queried against the Drug-Gene Interaction database to find drug candidates for topical use in OM. Our analysis identified 447 genes common to both the "OM" and "wound healing" text mining concepts. Gene enrichment analysis yielded 20 genes representing six pathways and targetable by a total of 32 drugs which could possibly be formulated for topical application. A manual search on ClinicalTrials.gov confirmed no relevant pathway/drug candidate had been overlooked. Twenty-five of the 32 drugs can directly affect the PTGS2 (COX-2) pathway, the pathway that has been targeted in previous clinical trials with limited success. Drug discovery using in silico text mining and pathway analysis tools can facilitate the identification of existing drugs that have the potential of topical administration to improve OM treatment.

Efficacy of Oral Cryotherapy on Oral Mucositis Prevention in Patients with Hematological Malignancies Undergoing Hematopoietic Stem Cell Transplantation: A Meta-Analysis of Randomized Controlled Trials

PubMed Central

Zhai, Ruiren; Zhao, Shasha; Luo, Lan; Li, Dandan; Zhao, Xiaoli; Wei, Huaping; Pang, Zhaoxia; Wang, Lili; Liu, Daihong; Wang, Quanshun; Gao, Chunji

2015-01-01

Objectives Controversy exists regarding whether oral cryotherapy can prevent oral mucositis (OM) in patients with hematological malignancies undergoing hematopoietic stem cell transplantation (HSCT). The aim of the present meta-analysis was to evaluate the efficacy of oral cryotherapy for OM prevention in patients with hematological malignancies undergoing HSCT. Methods PubMed and the Cochrane Library were searched through October 2014. Randomized controlled trials (RCTs) comparing the effect of oral cryotherapy with no treatment or with other interventions for OM in patients undergoing HSCT were included. The primary outcomes were the incidence, severity, and duration of OM. The secondary outcomes included length of analgesic use, total parenteral nutrition (TPN) use, and length of hospital stay. Results Seven RCTs involving eight articles analyzing 458 patients were included. Oral cryotherapy significantly decreased the incidence of severe OM (RR = 0.52, 95% CI = 0.27 to 0.99) and OM severity (SMD = -2.07, 95% CI = -3.90 to -0.25). In addition, the duration of TPN use and the length of hospitalization were markedly reduced (SMD = -0.56, 95% CI = -0.92 to -0.19; SMD = -0.44, 95% CI = -0.76 to -0.13; respectively). However, the pooled results were uncertain for the duration of OM and analgesic use (SMD = -0.13, 95% CI = -0.41 to 0.15; SMD = -1.15, 95% CI = -2.57 to 0.27; respectively). Conclusions Oral cryotherapy is a readily applicable and cost-effective prophylaxis for OM in patients undergoing HSCT. PMID:26024220

Efficacy of oral cryotherapy on oral mucositis prevention in patients with hematological malignancies undergoing hematopoietic stem cell transplantation: a meta-analysis of randomized controlled trials.

PubMed

Wang, Li; Gu, Zhenyang; Zhai, Ruiren; Zhao, Shasha; Luo, Lan; Li, Dandan; Zhao, Xiaoli; Wei, Huaping; Pang, Zhaoxia; Wang, Lili; Liu, Daihong; Wang, Quanshun; Gao, Chunji

2015-01-01

Controversy exists regarding whether oral cryotherapy can prevent oral mucositis (OM) in patients with hematological malignancies undergoing hematopoietic stem cell transplantation (HSCT). The aim of the present meta-analysis was to evaluate the efficacy of oral cryotherapy for OM prevention in patients with hematological malignancies undergoing HSCT. PubMed and the Cochrane Library were searched through October 2014. Randomized controlled trials (RCTs) comparing the effect of oral cryotherapy with no treatment or with other interventions for OM in patients undergoing HSCT were included. The primary outcomes were the incidence, severity, and duration of OM. The secondary outcomes included length of analgesic use, total parenteral nutrition (TPN) use, and length of hospital stay. Seven RCTs involving eight articles analyzing 458 patients were included. Oral cryotherapy significantly decreased the incidence of severe OM (RR = 0.52, 95% CI = 0.27 to 0.99) and OM severity (SMD = -2.07, 95% CI = -3.90 to -0.25). In addition, the duration of TPN use and the length of hospitalization were markedly reduced (SMD = -0.56, 95% CI = -0.92 to -0.19; SMD = -0.44, 95% CI = -0.76 to -0.13; respectively). However, the pooled results were uncertain for the duration of OM and analgesic use (SMD = -0.13, 95% CI = -0.41 to 0.15; SMD = -1.15, 95% CI = -2.57 to 0.27; respectively). Oral cryotherapy is a readily applicable and cost-effective prophylaxis for OM in patients undergoing HSCT.

Anxiolytic effects of orcinol glucoside and orcinol monohydrate in mice.

PubMed

Wang, Xiaohong; Li, Guiyun; Li, Peng; Huang, Linyuan; Huang, Jianmei; Zhai, Haifeng

2015-06-01

Anxiety is a common psychological disorder, often occurring in combination with depression, but therapeutic drugs with high efficacy and safety are lacking. Orcinol glucoside (OG) was recently found to have an antidepressive action. To study the therapeutic potential of OG and orcinol monohydrate (OM) as anxiolytic agents. Anxiolytic effects in mice were measured using the elevated plus-maze, hole-board, and open-field tests. Eight groups of mice were included in each test. Thirty minutes before each test, mice in each group received one oral administration of OG (5, 10, or 20 mg/kg), OM (2.5, 5, or 10 mg/kg), the positive control diazepam (1 or 5 mg/kg), or control vehicle. Each mouse underwent only one test. Uptake of orcinol (5 mg/kg) in the brain was qualitatively detected using the HPLC-MS method. OG (5, 10, and 20 mg/kg) and OM (2.5 and 5 mg/kg) increased the time spent in open arms and the number of entries into open arms in the elevated plus-maze test. OG (5 and 10 mg/kg) and OM (2.5 and 5 mg/kg) increased the number of head-dips in the hole-board test. At all tested doses, OG and OM did not significantly affect the locomotion of mice in the open-field test. Orcinol could be detected in the mouse brain homogenates 30 min after oral OM administration, having confirmed that OM is centrally active. The results demonstrated that OG and OM are anxiolytic agents without sedative effects, indicating their therapeutic potential for anxiety.

Noninvasive in vivo optical detection of biofilm in the human middle ear.

PubMed

Nguyen, Cac T; Jung, Woonggyu; Kim, Jeehyun; Chaney, Eric J; Novak, Michael; Stewart, Charles N; Boppart, Stephen A

2012-06-12

Otitis media (OM), a middle-ear infection, is the most common childhood illness treated by pediatricians. If inadequately treated, OM can result in long-term chronic problems persisting into adulthood. Children with chronic OM or recurrent OM often have conductive hearing loss and communication difficulties and require surgical treatment. Tympanostomy tube insertion, the placement of a small drainage tube in the tympanic membrane (TM), is the most common surgical procedure performed in children under general anesthesia. Recent clinical studies have shown evidence of a direct correspondence between chronic OM and the presence of a bacterial biofilm within the middle ear. Biofilms are typically very thin and cannot be recognized using a regular otoscope. Here we report the use of optical coherent ranging techniques to noninvasively assess the middle ear to detect and quantify biofilm microstructure. This study involves adults with chronic OM, which is generally accepted as a biofilm-related disease. Based on more than 18,537 optical ranging scans and 742 images from 13 clinically infected patients and 7 normal controls using clinical findings as the gold standard, all middle ears with chronic OM showed evidence of biofilms, and all normal ears did not. Information on the presence of a biofilm, along with its structure and response to antibiotic treatment, will not only provide a better fundamental understanding of biofilm formation, growth, and eradication in the middle ear, but also may provide much-needed quantifiable data to enable early detection and quantitative longitudinal treatment monitoring of middle-ear biofilms responsible for chronic OM.

Noninvasive in vivo optical detection of biofilm in the human middle ear

PubMed Central

Jung, Woonggyu; Kim, Jeehyun; Chaney, Eric J.; Novak, Michael; Stewart, Charles N.; Boppart, Stephen A.

2012-01-01

Otitis media (OM), a middle-ear infection, is the most common childhood illness treated by pediatricians. If inadequately treated, OM can result in long-term chronic problems persisting into adulthood. Children with chronic OM or recurrent OM often have conductive hearing loss and communication difficulties and require surgical treatment. Tympanostomy tube insertion, the placement of a small drainage tube in the tympanic membrane (TM), is the most common surgical procedure performed in children under general anesthesia. Recent clinical studies have shown evidence of a direct correspondence between chronic OM and the presence of a bacterial biofilm within the middle ear. Biofilms are typically very thin and cannot be recognized using a regular otoscope. Here we report the use of optical coherent ranging techniques to noninvasively assess the middle ear to detect and quantify biofilm microstructure. This study involves adults with chronic OM, which is generally accepted as a biofilm-related disease. Based on more than 18,537 optical ranging scans and 742 images from 13 clinically infected patients and 7 normal controls using clinical findings as the gold standard, all middle ears with chronic OM showed evidence of biofilms, and all normal ears did not. Information on the presence of a biofilm, along with its structure and response to antibiotic treatment, will not only provide a better fundamental understanding of biofilm formation, growth, and eradication in the middle ear, but also may provide much-needed quantifiable data to enable early detection and quantitative longitudinal treatment monitoring of middle-ear biofilms responsible for chronic OM. PMID:22645342

Omega-3 carboxylic acids (Epanova): a review of its use in patients with severe hypertriglyceridemia.

PubMed

Blair, Hannah A; Dhillon, Sohita

2014-10-01

Omega-3 carboxylic acids (Epanova) [OM3-CA] is the first free fatty acid form of long-chain marine omega-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid being the most abundant) to be approved by the US FDA as an adjunct to diet to lower triglyceride levels in patients with severe hypertriglyceridemia (≥ 500 mg/dL). Oral OM3-CA has greater bioavailability than ethyl ester forms of omega-3 and, unlike omega-3 acid ethyl esters, does not require co-ingestion of a high-fat meal, as it does not need pancreatic enzyme activity for absorption. In the 12-week EpanoVa fOr Lowering Very high triglyceridEs (EVOLVE) trial, OM3-CA 2 or 4 g/day significantly reduced serum triglyceride levels relative to placebo. Other lipid parameters, including non-high-density lipoprotein cholesterol (non-HDL-C), total cholesterol, and very low-density lipoprotein cholesterol (VLDL-C) levels, were also reduced significantly with OM3-CA relative to placebo. Low-density lipoprotein cholesterol levels were increased significantly with OM3-CA relative to placebo; however, these increases were not accompanied by increases in the circulating concentrations of non-HDL-C, VLDL-C, or apolipoprotein B. OM3-CA was generally well tolerated in this study, with most adverse events being of mild or moderate severity. Although additional comparative data are needed to position OM3-CA with respect to other formulations of omega-3 fatty acids, current evidence suggests that OM3-CA is a useful addition to the treatment options available for patients with severe hypertriglyceridemia.

Blue Guardian: open architecture intelligence, surveillance, and reconnaissance (ISR) demonstrations

NASA Astrophysics Data System (ADS)

Shirey, Russell G.; Borntrager, Luke A.; Soine, Andrew T.; Green, David M.

2017-04-01

The Air Force Research Laboratory (AFRL) - Sensors Directorate has developed the Blue Guardian program to demonstrate advanced sensing technology utilizing open architectures in operationally relevant environments. Blue Guardian has adopted the core concepts and principles of the Air Force Rapid Capabilities Office (AFRCO) Open Mission Systems (OMS) initiative to implement an open Intelligence, Surveillance and Reconnaissance (ISR) platform architecture. Using this new OMS standard provides a business case to reduce cost and program schedules for industry and the Department of Defense (DoD). Blue Guardian is an early adopting program of OMS and provides much needed science and technology improvements, development, testing, and implementation of OMS for ISR purposes. This paper presents results and lessons learned under the Blue Guardian Project Shepherd program which conducted Multi-INT operational demonstrations in the Joint Interagency Task Force - South (JIATF-S) and USSOUTHCOM area of operations in early 2016. Further, on-going research is discussed to enhance Blue Guardian Multi-INT ISR capabilities to support additional mission sets and platforms, including unmanned operations over line of sight (LOS) and beyond line of sight (BLOS) datalinks. An implementation of additional OMS message sets and services to support off-platform sensor command and control using OMS/UCI data structures and dissemination of sensor product data/metadata is explored. Lastly, the Blue Guardian team is working with the AgilePod program to use OMS in a full Government Data Rights Pod to rapidly swap these sensors to different aircraft. The union of the AgilePod (which uses SOSA compliant standards) and OMS technologies under Blue Guardian programs is discussed.

21 CFR 172.410 - Calcium silicate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Calcium silicate. 172.410 Section 172.410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Agents § 172.410 Calcium silicate. Calcium silicate, including synthetic calcium silicate, may be safely...

21 CFR 172.410 - Calcium silicate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium silicate. 172.410 Section 172.410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Agents § 172.410 Calcium silicate. Calcium silicate, including synthetic calcium silicate, may be safely...

21 CFR 172.410 - Calcium silicate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium silicate. 172.410 Section 172.410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Agents § 172.410 Calcium silicate. Calcium silicate, including synthetic calcium silicate, may be safely...

21 CFR 172.410 - Calcium silicate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Calcium silicate. 172.410 Section 172.410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Agents § 172.410 Calcium silicate. Calcium silicate, including synthetic calcium silicate, may be safely...

21 CFR 172.410 - Calcium silicate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium silicate. 172.410 Section 172.410 Food and... PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Anticaking Agents § 172.410 Calcium silicate. Calcium silicate, including synthetic calcium silicate, may be safely used in food in accordance with the...

Prediction of manure nitrogen and organic matter excretion for young Holstein cattle fed on grass silage-based diets.

PubMed

Jiao, H P; Yan, T; McDowell, D A

2014-07-01

The objectives of the present study were to evaluate the effects of sex (steers vs. heifers) of young Holstein cattle on N and OM excretion in feces and urine and to use these data to develop prediction models for N and OM excretion. Data used were derived from a study with 20 autumn-born Holstein cattle (10 steers and 10 heifers) with N and OM intake and output measured at age of 6, 12, 18, and 22 mo, respectively. The cattle were offered a typical diet used on U.K. commercial farms containing a single grass silage mixed with concentrates. In each period, the cattle were housed as a single group in cubicle accommodation for the first 20 d, individually in metabolism units for the next 3 d, and then in calorimeter chambers for the final 5 d with feed intake, feces, and urine excretion measured during the final 4 d. Within each period, sex had no effect (P > 0.05) on N or OM intake or excretion or N utilization efficiency, with exceptions of steers having a greater intake of N (P = 0.036) and OM (P = 0.018) at age of 18 mo and a lower ratio of fecal N:N intake (P = 0.023) at age of 6 mo. A range of regression relationships (P < 0.05) were developed for prediction of N (g/d) and OM (kg/d) excretion in feces and urine. The present data were also used to calculate accumulated N and OM intake (kg) and excretion for the 2 sexes. Sex had no effects (P > 0.05) on accumulated N or OM intake or N or OM excretion in feces and urine or retained N and OM during the first or second year of life. On average for the 2 sexes at first and second year of age, the accumulated N excretions in feces were 11.4 and 21.1 kg and in urine 11.6 and 30.6 kg, respectively, and the corresponding values for accumulated OM excretions were respectively 241.5, 565.7, 30.3 and 81.5 kg. A number of equations were developed to predict accumulated N and OM excretion in feces and urine (kg) using BW (kg; P < 0.001, r(2) = 0.95 to 0.97). The accurate prediction of N and OM excretion in feces and urine is essential for reducing N pollution to ground and surface water and calculating methane and nitrous oxide emissions from manure management of dairy and beef production systems. These data can add novel information to the scientific literature and can be used to improve national inventories of manure N output and greenhouse gas emissions and to develop appropriate mitigation strategies for young Holstein cattle.

EVALUATION OF AIRBORNE ASBESTOS CONCENTRATIONS BEFORE AND DURING AND O&M ACTIVITY: A CASE STUDY

EPA Science Inventory

The current lack of information regarding the impact of O&M activities on the potential for asbestos exposure to building staff and occupants prompted this study. This report presents a statistical evaluation of airborne asbestos data collected before and during an O&M activity i...

77 FR 10767 - Rate Adjustments for Indian Irrigation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-23

... Irrigation Project on the proposed rates about the following issues: (1) The methodology for O&M rate setting... BIA's responses are provided below. Comment: The BIA's methodology for setting the 2013 O&M assessment rate was unreasonable. Response: The methodology used by the BIA to determine the 2013 O&M assessment...

Operations Management Teaching: Establishing Content and Relevance to Practitioners

ERIC Educational Resources Information Center

Doran, Desmond; Hill, Alex; Brown, Steve; Aktas, Emel; Kuula, Markku

2013-01-01

This paper explores the relevance to industry's needs of operations management (OM) teaching in higher education, by researching the content of OM modules delivered by UK academics and comparing the results of this research with the views of business practitioners having had first-hand experience of OM teaching on MBA programmes. To determine…

Vestibular Dysfunction in Preschool Children with a History of Otitis Media.

ERIC Educational Resources Information Center

Denning, Jennifer; Mayberry, Wanda

1987-01-01

Thirty-five preschoolers, assigned to otitis media (OM) or no OM groups, were administered the Southern California Postrotary Nystagmus Test and the Miller Assessment for Preschoolers (MAP). Children with a history of OM had significantly decreased scores on the Stepping and Vertical Writing MAP tests, indicating vestibulospinal dysfunction. (SK)

43 CFR 426.23 - Recovery of operation and maintenance (O&M) costs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... operation and maintenance (O&M) costs. (a) General. All new, amended, and renewed contracts shall provide... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Recovery of operation and maintenance (O&M) costs. 426.23 Section 426.23 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF...

Use of Outcome Measurement by Paediatric AHPs in Northern Ireland

ERIC Educational Resources Information Center

Harron, Anita; Titterington, Jill

2016-01-01

Background: Professional standards advocate routine use of outcome measurement (OM) in the practice of allied health professionals (AHPs). Historically, OM has focused on impairment and its immediate constraints on activity, while current policy encourages the development and addition of impact-based OM. There appears to be an assumption at this…

Solar PV O&M Standards and Best Practices – Existing Gaps and Improvement Efforts

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

Klise, Geoffrey Taylor; Balfour, John R.; Keating, T. J.

2014-11-01

As greater numbers of photovoltaic (PV) systems are being installed, operations & maintenance (O&M) activities will need to be performed to ensure the PV system is operating as designed over its useful lifetime. To mitigate risks to PV system availability and performance, standardized procedures for O&M activities are needed to ensure high reliability and long-term system bankability. Efforts are just getting underway to address the need for standard O&M procedures as PV gains a larger share of U.S. generation capacity. Due to the existing landscape of how and where PV is installed, including distributed generation from small and medium PVmore » systems, as well as large, centralized utility-scale PV, O&M activities will require different levels of expertise and reporting, making standards even more important. This report summarizes recent efforts made by solar industry stakeholders to identify the existing standards and best practices applied to solar PV O&M activities, and determine the gaps that have yet to be, or are currently being addressed by industry.« less

Solar PV O&M Standards and Best Practices - Existing Gaps and Improvement Efforts

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

Klise, Geoffrey Taylor; Balfour, John R.; Keating, T. J.

2014-11-01

As greater numbers of photovoltaic (PV) systems are being installed, operations & maintenance (O&M) activities will need to be performed to ensure the PV system is operating as designed over its useful lifetime. To mitigate risks to PV system availability and performance, standardized procedures for O&M activities are needed to ensure high reliability and long-term system bankability. Efforts are just getting underway to address the need for standard O&M procedures as PV gains a larger share of U.S. generation capacity. Due to the existing landscape of how and where PV is installed, including distributed generation from small and medium PVmore » systems, as well as large, centralized utility-scale PV, O&M activities will require different levels of expertise and reporting, making standards even more important. This report summarizes recent efforts made by solar industry stakeholders to identify the existing standards and best practices applied to solar PV O&M activities, and determine the gaps that have yet to be, or are currently being addressed by industry.« less

Recent Advances in Studies of Ionospheric Modification Using Rocket Exhaust (Invited)

NASA Astrophysics Data System (ADS)

Bernhardt, P. A.

2009-12-01

Rocket exhaust interacts with the ionosphere to produce a wide range of disturbances. A ten second burn of the Orbital Maneuver Subsystem (OMS) engines on the Space Shuttle deposits over 1 Giga Joule of energy into the upper atmosphere. The exhaust vapors travel at speeds between 4.7 and 10.7 km/s coupling momentum into the ions by both collisions and charge exchange. Long-lived plasma irregularities are formed by the artificial hypersonic “neutral wind” passing through the ionosphere. Charge exchange between the fast neutrals and the ambient ions yields high-speed ion beams that excite electro-static plasma waves. Ground based radar has been used to detect both field aligned irregularities and electrostatic turbulence driven by the Space Shuttle OMS exhaust. Molecular ions produced by the charge exchange with molecules in the rocket exhaust recombine with a time scale of 10 minutes leaving a residual plasma depression. This ionospheric “hole” fills in by ambipolar diffusion leaving a depleted magnetic flux tube. This large scale reduction in Pedersen conductivity can provide a seed for plasma interchange instabilities. For instance, a rocket firing on the bottom side of the ionosphere near the equator can trigger a Rayleigh-Taylor instability that is naturally seen as equatorial Spread-F. The Naval Research Laboratory has been exploring these phenomena with dedicated burns of the Space Shuttle OMS engines and exhaust releases from rockets. The Shuttle Ionospheric Modification with Pulsed Localized Exhaust (SIMPLEX) series of experiments uses ground radars to probe the ionosphere affected by dedicated burns of the Space Shuttle OMS engines. Radars located at Millstone Hill, Massachusetts; Arecibo, Puerto Rico; Jicamarca, Peru; Kwajalein, Marshall Island; and Alice Springs, Australia have participated in the SIMPLEX program. A companion program called Shuttle Exhaust Ionospheric Turbulence Experiment has or will use satellites to fly through the turbulence ionosphere produced by Space Shuttle Exhaust. This program is employing the Air Force Research Laboratory C/NOFS and the Canadian CASSIOPE/EPoP satellites to make in situ measurements of Space Shuttle exhaust effects. Finally, NRL is conducting the Charged Aerosol Release Experiment which employs a solid rocket motor to modify the ionosphere using supersonic particulate injection and dusty plasma formation. Both the theoretic basis for these experiments and as summary of the experimental results will be presented.

Biological and therapeutic effects of ortho-silicic acid and some ortho-silicic acid-releasing compounds: New perspectives for therapy.

PubMed

Jurkić, Lela Munjas; Cepanec, Ivica; Pavelić, Sandra Kraljević; Pavelić, Krešimir

2013-01-08

Silicon (Si) is the most abundant element present in the Earth's crust besides oxygen. However, the exact biological roles of silicon remain unknown. Moreover, the ortho-silicic acid (H4SiO4), as a major form of bioavailable silicon for both humans and animals, has not been given adequate attention so far. Silicon has already been associated with bone mineralization, collagen synthesis, skin, hair and nails health atherosclerosis, Alzheimer disease, immune system enhancement, and with some other disorders or pharmacological effects. Beside the ortho-silicic acid and its stabilized formulations such as choline chloride-stabilized ortho-silicic acid and sodium or potassium silicates (e.g. M2SiO3; M= Na,K), the most important sources that release ortho-silicic acid as a bioavailable form of silicon are: colloidal silicic acid (hydrated silica gel), silica gel (amorphous silicon dioxide), and zeolites. Although all these compounds are characterized by substantial water insolubility, they release small, but significant, equilibrium concentration of ortho-silicic acid (H4SiO4) in contact with water and physiological fluids. Even though certain pharmacological effects of these compounds might be attributed to specific structural characteristics that result in profound adsorption and absorption properties, they all exhibit similar pharmacological profiles readily comparable to ortho-silicic acid effects. The most unusual ortho-silicic acid-releasing agents are certain types of zeolites, a class of aluminosilicates with well described ion(cation)-exchange properties. Numerous biological activities of some types of zeolites documented so far might probably be attributable to the ortho-silicic acid-releasing property. In this review, we therefore discuss biological and potential therapeutic effects of ortho-silicic acid and ortho-silicic acid -releasing silicon compounds as its major natural sources.

Broncho Vaxom (OM-85) modulates rhinovirus docking proteins on human airway epithelial cells via Erk1/2 mitogen activated protein kinase and cAMP

PubMed Central

Pasquali, Christian; Stolz, Daiana; Tamm, Michael

2017-01-01

Background Bronchial epithelial cells (BEC) are primary target for Rhinovirus infection through attaching to cell membrane proteins. OM-85, a bacterial extract, improves recovery of asthma and COPD patients after viral infections, but only part of the mechanism was addressed, by focusing on defined immune cells. Objective We therefore determined the effect of OM-85 on isolated primary human BEC of controls (n = 8), asthma patients (n = 10) and COPD patients (n = 9). Methods BEC were treated with OM-85 alone (24 hours) or infected with Rhinovirus. BEC survival was monitored by manual cell counting and Rhinovirus replication by lytic activity. Immuno-blotting and ELISA were used to determine the expression of Rhinovirus interacting proteins: intracellular adhesion molecule (ICAM), major histocompatibility complex class II (MHC-2), complement component C1q receptor (C1q-R), inducible T-Cell co-stimulator (ICOS), its ligand ICOSL, and myeloid differentiation primary response gene 88 (Myd88); as well as for signal transducers Erk1/2, p38, JNK mitogen activated protein kinases MAPK), and cAMP. Results OM-85 significantly reduced Rhinovirus-induced BEC death and virus replication. OM-85 significantly increased the expression of virus interacting proteins C1q-R and β-defensin in all 3 probes and groups, which was prevented by either Erk1/2 MAPK or cAMP inhibition. In addition, OM-85 significantly reduced Rhinovirus induced expression of ICAM1 involving p38 MAPK. In BEC OM-85 had no significant effect on the expression of ICOS, ICOSL and MHC-2 membrane proteins nor on the adaptor protein MyD88. Conclusion The OM-85-induced increased of C1q-R and β-defensin, both important for antigen presentation and phagocytosis, supports its activity in host cell’s defence against Rhinovirus infection. PMID:29182620

Annual burning of a tallgrass prairie inhibits C and N cycling in soil, increasing recalcitrant pyrogenic organic matter storage while reducing N availability.

PubMed

Soong, Jennifer L; Cotrufo, M Francesca

2015-06-01

Grassland ecosystems store an estimated 30% of the world's total soil C and are frequently disturbed by wildfires or fire management. Aboveground litter decomposition is one of the main processes that form soil organic matter (SOM). However, during a fire biomass is removed or partially combusted and litter inputs to the soil are substituted with inputs of pyrogenic organic matter (py-OM). Py-OM accounts for a more recalcitrant plant input to SOM than fresh litter, and the historical frequency of burning may alter C and N retention of both fresh litter and py-OM inputs to the soil. We compared the fate of these two forms of plant material by incubating (13) C- and (15) N-labeled Andropogon gerardii litter and py-OM at both an annually burned and an infrequently burned tallgrass prairie site for 11 months. We traced litter and py-OM C and N into uncomplexed and organo-mineral SOM fractions and CO2 fluxes and determined how fire history affects the fate of these two forms of aboveground biomass. Evidence from CO2 fluxes and SOM C:N ratios indicates that the litter was microbially transformed during decomposition while, besides an initial labile fraction, py-OM added to SOM largely untransformed by soil microbes. Additionally, at the N-limited annually burned site, litter N was tightly conserved. Together, these results demonstrate how, although py-OM may contribute to C and N sequestration in the soil due to its resistance to microbial degradation, a long history of annual removal of fresh litter and input of py-OM infers N limitation due to the inhibition of microbial decomposition of aboveground plant inputs to the soil. These results provide new insight into how fire may impact plant inputs to the soil, and the effects of py-OM on SOM formation and ecosystem C and N cycling. © 2014 John Wiley & Sons Ltd.

Broncho Vaxom (OM-85) modulates rhinovirus docking proteins on human airway epithelial cells via Erk1/2 mitogen activated protein kinase and cAMP.

PubMed

Roth, Michael; Pasquali, Christian; Stolz, Daiana; Tamm, Michael

2017-01-01

Bronchial epithelial cells (BEC) are primary target for Rhinovirus infection through attaching to cell membrane proteins. OM-85, a bacterial extract, improves recovery of asthma and COPD patients after viral infections, but only part of the mechanism was addressed, by focusing on defined immune cells. We therefore determined the effect of OM-85 on isolated primary human BEC of controls (n = 8), asthma patients (n = 10) and COPD patients (n = 9). BEC were treated with OM-85 alone (24 hours) or infected with Rhinovirus. BEC survival was monitored by manual cell counting and Rhinovirus replication by lytic activity. Immuno-blotting and ELISA were used to determine the expression of Rhinovirus interacting proteins: intracellular adhesion molecule (ICAM), major histocompatibility complex class II (MHC-2), complement component C1q receptor (C1q-R), inducible T-Cell co-stimulator (ICOS), its ligand ICOSL, and myeloid differentiation primary response gene 88 (Myd88); as well as for signal transducers Erk1/2, p38, JNK mitogen activated protein kinases MAPK), and cAMP. OM-85 significantly reduced Rhinovirus-induced BEC death and virus replication. OM-85 significantly increased the expression of virus interacting proteins C1q-R and β-defensin in all 3 probes and groups, which was prevented by either Erk1/2 MAPK or cAMP inhibition. In addition, OM-85 significantly reduced Rhinovirus induced expression of ICAM1 involving p38 MAPK. In BEC OM-85 had no significant effect on the expression of ICOS, ICOSL and MHC-2 membrane proteins nor on the adaptor protein MyD88. The OM-85-induced increased of C1q-R and β-defensin, both important for antigen presentation and phagocytosis, supports its activity in host cell's defence against Rhinovirus infection.

Multi-institutional comparison of whole slide digital imaging and optical microscopy for interpretation of hematoxylin-eosin-stained breast tissue sections.

PubMed

Krishnamurthy, Savitri; Mathews, Kurt; McClure, Steven; Murray, Melissa; Gilcrease, Michael; Albarracin, Constance; Spinosa, John; Chang, Bernard; Ho, James; Holt, John; Cohen, Arthur; Giri, Dilip; Garg, Karuna; Bassett, Roland L; Liang, Kevin

2013-12-01

Whole slide imaging (WSI) is now used for educational purposes, for consultation, and for archiving and quantitation of immunostains. However, it is not routinely used for the primary diagnosis of hematoxylin-eosin-stained tissue sections. To compare WSI using the Aperio digital pathology system (Aperio Technologies, Inc, Vista, California) with optical microscopy (OM) for the interpretation of hematoxylin-eosin-stained tissue sections of breast lesions. The study was conducted at 3 clinical sites; 3 breast pathologists interpreted 150 hematoxylin-eosin-stained slides at each site, 3 times each by WSI and 3 times each by OM. For WSI, slides were scanned using an Aperio ScanScope and interpreted on a computer monitor using Aperio ImageScope software and Aperio Spectrum data management software. Pathologic interpretations were recorded using the College of American Pathologists breast checklist. WSI diagnoses were compared with OM diagnoses for accuracy, precision (interpathologist variation), and reproducibility (intrapathologist variation). Results were considered accurate only if the interpretation matched exactly between WSI and OM. The proportion of accurate results reported by each pathologist was expressed as a percentage for the comparison of the 2 platforms. The accuracy of WSI for classifying lesions as not carcinoma or as noninvasive (ductal or lobular) or invasive (ductal, lobular, or other) carcinoma was 90.5%. The accuracy of OM was 92.1%. The precision and reproducibility of WSI and OM were determined on the basis of pairwise comparisons (3 comparisons for each slide, resulting in 36 possible comparisons). The overall precision of WSI was 90.5% in comparison with 92.1% for OM; reproducibility of WSI was 91.6% in comparison with 94.5% for OM, respectively. In this study, we demonstrated that WSI and OM have similar accuracy, precision, and reproducibility for interpreting hematoxylin-eosin-stained breast tissue sections. Further clinical studies using routine surgical pathology specimens would be useful to confirm these findings and facilitate the incorporation of WSI into diagnostic practice.

CEBS object model for systems biology data, SysBio-OM.

PubMed

Xirasagar, Sandhya; Gustafson, Scott; Merrick, B Alex; Tomer, Kenneth B; Stasiewicz, Stanley; Chan, Denny D; Yost, Kenneth J; Yates, John R; Sumner, Susan; Xiao, Nianqing; Waters, Michael D

2004-09-01

To promote a systems biology approach to understanding the biological effects of environmental stressors, the Chemical Effects in Biological Systems (CEBS) knowledge base is being developed to house data from multiple complex data streams in a systems friendly manner that will accommodate extensive querying from users. Unified data representation via a single object model will greatly aid in integrating data storage and management, and facilitate reuse of software to analyze and display data resulting from diverse differential expression or differential profile technologies. Data streams include, but are not limited to, gene expression analysis (transcriptomics), protein expression and protein-protein interaction analysis (proteomics) and changes in low molecular weight metabolite levels (metabolomics). To enable the integration of microarray gene expression, proteomics and metabolomics data in the CEBS system, we designed an object model, Systems Biology Object Model (SysBio-OM). The model is comprehensive and leverages other open source efforts, namely the MicroArray Gene Expression Object Model (MAGE-OM) and the Proteomics Experiment Data Repository (PEDRo) object model. SysBio-OM is designed by extending MAGE-OM to represent protein expression data elements (including those from PEDRo), protein-protein interaction and metabolomics data. SysBio-OM promotes the standardization of data representation and data quality by facilitating the capture of the minimum annotation required for an experiment. Such standardization refines the accuracy of data mining and interpretation. The open source SysBio-OM model, which can be implemented on varied computing platforms is presented here. A universal modeling language depiction of the entire SysBio-OM is available at http://cebs.niehs.nih.gov/SysBioOM/. The Rational Rose object model package is distributed under an open source license that permits unrestricted academic and commercial use and is available at http://cebs.niehs.nih.gov/cebsdownloads. The database and interface are being built to implement the model and will be available for public use at http://cebs.niehs.nih.gov.

Non-Toxic Orbiter Maneuvering System (OMS) and Reaction Control System

NASA Technical Reports Server (NTRS)

Hurlbert, Eric A.; Nicholson, Leonard S. (Technical Monitor)

1999-01-01

NASA is pursuing the technology and advanced development of a non-toxic (NT) orbital maneuvering system (OMS) and reaction control system (RCS) for shuttle upgrades, RLV, and reusable first stages. The primary objectives of the shuttle upgrades program are improved safety, improved reliability, reduced operations time and cost, improved performance or capabilities, and commonality with future space exploration needs. Non-Toxic OMS/RCS offers advantages in each of these categories. A non-toxic OMS/RCS eliminates the ground hazards and the flight safety hazards of the toxic and corrosive propellants. The cost savings for ground operations are over $24M per year for 7 flights, and the savings increase with increasing flight rate up to $44M per year. The OMS/RCS serial processing time is reduced from 65 days to 13 days. The payload capability can be increased up to 5100 Ibms. The non-toxic OMS/RCS also provides improved space station reboost capability up to 20 nautical miles over the current toxic system of 14 nautical miles. A NT OMS/RCS represents a clear advancement in the SOA over MMH/NTO. Liquid oxygen and ethanol are clean burning, high-density propellants that provide a high degree of commonality with other spacecraft subsystems including life support, power, and thermal control, and with future human exploration and development of space missions. The simple and reliable pressure-fed design uses sub-cooled liquid oxygen at 250 to 350 psia, which allows a propellant to remain cryogenic for longer periods of time. The key technologies are thermal insulation and conditioning techniques are used to maintain the sub-cooling. Phase I successfully defined the system architecture, designed an integrated OMS/RCS propellant tank, analyzed the feed system, built and tested the 870 lbf RCS thrusters, and tested the 6000 lbf OMS engine. Phase 11 is currently being planned for the development and test of full-scale prototype of the system in 1999 and 2000

Omega-3 fatty acid fish oil dietary supplements contain saturated fats and oxidized lipids that may interfere with their intended biological benefits.

PubMed

Mason, R Preston; Sherratt, Samuel C R

2017-01-29

Widely available fish oil dietary supplements (DS) may contain fats and oxidized lipids in addition to the beneficial omega-3 fatty acids (OM3FAs) for which they are purchased. Little is known about the potential biological effects of these oxidized lipids. The objective of this study was to assess the fatty acid content, oxidation products, and biological effects of leading fish oil DS available in the United States. Three top-selling fish oil DS in the US were included in this analysis. Fatty acid composition was measured using gas chromatography. Lipid oxidation (primary and secondary products) was measured by spectroscopy in both DS and a prescription OM3FA product. OM3FAs were also isolated and concentrated from DS and were tested for the ability to inhibit copper-induced oxidation of human small dense low-density lipoprotein particles (sdLDL) in vitro. Fish oil DS were found to contain more than 30 different fatty acids, including 10 to 14 different saturated species comprising up to 36% of the total fatty acid content. Levels of OM3FAs also varied widely among DS (33%-79%). Primary (peroxide), secondary (anisidine), and total oxidation products exceeded maximum levels established by international standards of quality in the DS but not the prescription OM3FA product. Oxidation of sdLDL was inhibited by >95% (P < 0.001) with non-oxidized forms of OM3FA but not with OM3FAs isolated from DS, which were a mixture of oxidized and non-oxidized OM3FAs. These data indicate that levels of saturated fat and oxidized OM3FAs found in common DS may interfere with their intended/potential biological benefits. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Method 366.0 Determination of Dissolved Silicate in Estuarine and Coastal Watersby Gas Segmented Continuous Flow Colorimetric Analysis

EPA Science Inventory

This method provides a procedure for the determination of dissolved silicate concentration in estuarine and coastal waters. The dissolved silicate is mainly in the form of silicic acid, H SiO , in estuarine and 4 4 coastal waters. All soluble silicate, including colloidal silici...

Non-conductive nanomaterial enhanced electrochemical response in stripping voltammetry: The use of nanostructured magnesium silicate hollow spheres for heavy metal ions detection.

PubMed

Xu, Ren-Xia; Yu, Xin-Yao; Gao, Chao; Jiang, Yu-Jing; Han, Dong-Dong; Liu, Jin-Huai; Huang, Xing-Jiu

2013-08-06

Nanostructured magnesium silicate hollow spheres, one kind of non-conductive nanomaterials, were used in heavy metal ions (HMIs) detection with enhanced performance for the first time. The detailed study of the enhancing electrochemical response in stripping voltammetry for simultaneous detection of ultratrace Cd(2+), Pb(2+), Cu(2+) and Hg(2+) was described. Electrochemical properties of modified electrodes were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The operational parameters which have influence on the deposition and stripping of metal ions, such as supporting electrolytes, pH value, and deposition time were carefully studied. The anodic stripping voltammetric performance toward HMIs was evaluated using square wave anodic stripping voltammetry (SWASV) analysis. The detection limits achieved (0.186nM, 0.247nM, 0.169nM and 0.375nM for Cd(2+), Pb(2+), Cu(2+) and Hg(2+)) are much lower than the guideline values in drinking water given by the World Health Organization (WHO). In addition, the interference and stability of the modified electrode were also investigated under the optimized conditions. An interesting phenomenon of mutual interference between different metal ions was observed. Most importantly, the sensitivity of Pb(2+) increased in the presence of certain concentrations of other metal ions, such as Cd(2+), Cu(2+) and Hg(2+) both individually and simultaneously. The proposed electrochemical sensing method is thus expected to open new opportunities to broaden the use of SWASV in analysis for detecting HMIs in the environment. Copyright © 2013 Elsevier B.V. All rights reserved.

Salinization of porewater in a multiple aquitard-aquifer system in Jiangsu coastal plain, China

NASA Astrophysics Data System (ADS)

Li, Jing; Liang, Xing; Zhang, Yanian; Liu, Yan; Chen, Naijia; Abubakari, Alhassan; Jin, Menggui

2017-12-01

Chemical and isotopic compositions were analyzed in porewater squeezed from a clayey aquitard in Jiangsu coastal plain, eastern China, to interpret the salinity origin, chemical evolution and water-mass mixing process. A strong geochemical fingerprint was obtained with an aligned Cl/Br ratio of 154 in the salinized aquitard porewater over a wide Cl- concentration range (396-9,720 mg/L), indicating that porewater salinity is likely derived from a mixing with old brine with a proportion of less than 20%. Very small contributions of brine exerted limited effects on water stable isotopes. The relationships between porewater δ18O and δD indicate that shallow and intermediate porewaters could be original seawater and were subsequently diluted with modern meteoric water, whereas deep porewaters with depleted stable isotopic values were probably recharged during a cooler period and modified by evaporation and seawater infiltration. The cation-Cl relationship and mineralogy of associated strata indicate that porewater has been chemically modified by silicate weathering and ion-exchange reactions. 87Sr/86Sr ratios of 0.7094-0.7112 further confirm the input source of silicate minerals. Numerical simulations were used to evaluate the long-term salinity evolution of the deep porewater. The alternations of boundary conditions (i.e., the third aquifer mixed with brine at approximately 70 ka BP, followed by recharge of glacial meltwater at 20-25 ka BP, and then mixing with Holocene seawater at 7-10 ka BP) are responsible for the shift in porewater salinity. These timeframes correspond with the results of previous studies on ancient marine transgression-regression in Jiangsu coastal plain.

Organic metamorphism in the California petroleum basins; Chapter A, Rock-Eval and vitrinite reflectance

USGS Publications Warehouse

Price, Leigh C.; Pawlewicz, Mark J.; Daws, Ted A.

1999-01-01

The results of ROCK-EVAL and vitrinite reflectance analyses of a large sample base from more than 70 wells located in three oil-rich California petroleum basins are reported. The cores from these wells have a wide range of present-day burial temperatures (40 ? to 220 ? C). The rocks in these basins were deposited under highly variable conditions, sometimes resulting in substantially different organic matter (OM) types in rocks tens of meters vertically apart from each other in one well. The kinetic response of these different OM types to equivalent wellknown burial histories is a pivotal point of this study. In the Los Angeles and Ventura Basins, rock organic-richness significantly increased with depth, as did kerogen hydrogen content, and the percentage of fine-grained versus coarsegrained rocks. The shales in these basins are perceived as containing primarily hydrogen-rich amorphous OM. In actuality, the shallowest 2,000 to 3,000 m of rocks in the basins, and at least the upper 6,000 m of rocks in parts of the Los Angeles Basin central syncline, are dominated by type III/IV OM. In the Los Angeles Basin, mainstage hydrocarbon (HC) generation commences in the type III/IV OM at present-day burial temperatures of 85 ? to 110 ? C, most likely around 100 ? C, and is largely complete by 220 ? C. In the Southern San Joaquin Valley Basin, mainstage HC generation commences in type III/IV OM at 150 ? C and is also largely complete by 220 ? C. In the Ventura Basin, mainstage HC generation commences above 140 ? C in type III/IV OM. The apparent lower temperatures for commencement of HC generation in the Los Angeles Basin are attributed to the fact that parts of the basin were cooled from maximal burial temperatures by increased meteoric water flows during the last glaciations. All aspects of organic metamorphism, including mainstage HC generation, are strongly suppressed in rocks with hydrogenrich OM in these basins. For example, ROCK-EVAL data suggest that mainstage HC generation has not commenced in rocks with hydrogen-rich OM at present-day temperatures of 198?C. This observation is attributed to much stronger bonds in hydrogen- rich OM compared to types III and IV OM and, therefore, significantly higher burial temperatures are required to break these bonds. This difference in OM kinetics has profound ramifications for petroleum-geochemical exploration models. Organic-matter characteristics inherited from original depositional conditions were overlaid on, and at times confused interpretation of, characteristics from organic metamorphism in all study areas. In all the basins examined in this study, immature fine-grained rocks occasionally had high to very high carbon-normalized concentrations of pre-generation indigenous bitumen. This unusual characteristic may be due to unique depositional conditions in these basins.

Application of Green Tea Catechin for Inducing the Osteogenic Differentiation of Human Dedifferentiated Fat Cells in Vitro

PubMed Central

Kaida, Koji; Honda, Yoshitomo; Hashimoto, Yoshiya; Tanaka, Masahiro; Baba, Shunsuke

2015-01-01

Despite advances in stem cell biology, there are few effective techniques to promote the osteogenic differentiation of human primary dedifferentiated fat (DFAT) cells. We attempted to investigate whether epigallocatechin-3-gallate (EGCG), the main component of green tea catechin, facilitates early osteogenic differentiation and mineralization on DFAT cells in vitro. DFAT cells were treated with EGCG (1.25–10 μM) in osteogenic medium (OM) with or without 100 nM dexamethasone (Dex) for 12 days (hereafter two osteogenic media were designated as OM(Dex) and OM). Supplementation of 1.25 μM EGCG to both the media effectively increased the mRNA expression of collagen 1 (COL1A1) and runt-related transcription factor 2 (RUNX2) and also increased proliferation and mineralization. Compared to OM(Dex) with EGCG, OM with EGCG induced earlier expression for COL1A1 and RUNX2 at day 1 and higher mineralization level at day 12. OM(Dex) with 10 μM EGCG remarkably hampered the proliferation of the DFAT cells. These results suggest that OM(without Dex) with EGCG might be a preferable medium to promote proliferation and to induce osteoblast differentiation of DFAT cells. Our findings provide an insight for the combinatory use of EGCG and DFAT cells for bone regeneration and stem cell-based therapy. PMID:26602917

KSC-2012-3416

NASA Image and Video Library

2012-06-19

CAPE CANAVERAL, Fla. –Inside Orbiter Processing Facility-1 at NASA’s Kennedy Space Center in Florida, a unique close-up view shows a large crane lowering the right orbital maneuvering system, or OMS, pod closer to space shuttle Atlantis and the left OMS pod already installed. It is the last time an OMS pod will be installed on Atlantis. The OMS provided the shuttle with thrust for orbit insertion, rendezvous and deorbit, and could provide up to 1,000 pounds of propellant to the aft reaction control system. The OMS is housed in two independent pods located on each side of the shuttle’s aft fuselage. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers. Atlantis’ OMS pods were removed and sent to the test facility at White Sands Space Harbor in New Mexico to be cleaned of residual toxic propellant. The work is part of the Space Shuttle Program’s transition and retirement processing of the space shuttle fleet. A groundbreaking was held Jan. 18 for Atlantis’ future home, a 65,000-square-foot exhibit hall in Shuttle Plaza at the Kennedy Space Center Visitor Complex. Atlantis is scheduled to roll over to the visitor complex in November in preparation for the exhibit’s grand opening in July 2013. For more information, visit http://www.nasa.gov/transition. Photo credit: NASA/Dimitri Gerondidakis

Simultaneous removal of phosphorus and EfOM using MIEX, coagulation, and low-pressure membrane filtration.

PubMed

Kim, Hyun-Chul; Timmes, Thomas C; Dempsey, Brian A

2015-01-01

The feasibility of using magnetic ion exchange (MIEX) treatment, in-line alum coagulation, and low-pressure membrane filtration was investigated for the simultaneous removal of total phosphorus (TP) and effluent organic matter (EfOM) from biologically treated wastewater. The focus was also placed on minimizing fouling of polyvinylidene fluoride and polyethersulfone membranes, which are the most commonly used low-pressure membranes in new and retrofit wastewater treatment plants. MIEX alone was effective for the removal of EfOM, and MIEX plus a small alum dose was very effective in removing both EfOM and TP. MIEX removed phosphorus, but organic acids in EfOM were preferentially removed, and the effects of competing anions on the removal of EfOM were insignificant. All the pretreatment strategies decreased the resistance to filtration. The greatest decrease in fouling was achieved by using MIEX (15 mL L⁻¹) plus a very low dose of alum (∼0.5 mg Al L⁻¹). Sweep floc coagulation using alum and without MIEX also significantly decreased fouling but did not effectively remove EfOM and produced high floc volume that could be problematic for inside-out hollow-fibre modules. The addition of these reagents into rapid mix followed by membrane filtration would provide operational simplicity and could be easily retrofitted at existing membrane filtration facilities.

Otitis media induced by peptidoglycan-polysaccharide (PGPS) in TLR2-deficient (Tlr2(-/-)) mice for developing drug therapy.

PubMed

Zhang, Xiaolin; Zheng, Tihua; Sang, Lu; Apisa, Luke; Zhao, Hongchun; Fu, Fenghua; Wang, Qingzhu; Wang, Yanfei; Zheng, Qingyin

2015-10-01

Toll like receptor 2 (TLR2) signaling can regulate the pathogenesis of otitis media (OM). However, the precise role of TLR2 signaling in OM has not been clarified due to the lack of an optimal animal model. Peptidoglycan-polysaccharide (PGPS) of the bacterial cell wall can induce inflammation by activating the TLR2 signaling. This study aimed at examining the pathogenic characteristics of OM induced by PGPS in Tlr2(-/-) mice, and the potential therapeutic effect of sodium aescinate (SA) in this model. Wild-type (WT) and Tlr2(-/-) mice were inoculated with streptococcal PGPS into their middle ears (MEs) and treated intravenously with vehicle or SA daily beginning at 3days prior to PGPS for 6 consecutive days. The pathologic changes of individual mice were evaluated longitudinally. In comparison with WT mice, Tlr2(-/-) mice were susceptible to PGPS-induced OM. Tlr2(-/-) mice displayed greater hearing loss, tympanic membrane damage, ME mucosal thickening, longer inflammation state, cilia and goblet cell loss. SA-treatment decreased neutrophil infiltration, modulated TLR2-related gene expression and improved ciliary organization. PGPS induced a relatively stable OM in Tlr2(-/-) mice, providing a new model for OM research. Treatment with SA mitigated the pathogenic damage in the ME and may be valuable for intervention of OM. Copyright © 2015 Elsevier B.V. All rights reserved.

OM-85 is an immunomodulator of interferon-β production and inflammasome activity

PubMed Central

Dang, A. T.; Pasquali, C.; Ludigs, K.; Guarda, G.

2017-01-01

The inflammasome–IL-1 axis and type I interferons (IFNs) have been shown to exert protective effects upon respiratory tract infections. Conversely, IL-1 has also been implicated in inflammatory airway pathologies such as asthma and chronic obstructive pulmonary disease (COPD). OM-85 is a bacterial extract with proved efficacy against COPD and recurrent respiratory tract infections, a cause of co-morbidity in asthmatic patients. We therefore asked whether OM-85 affects the above-mentioned innate immune pathways. Here we show that OM-85 induced interferon-β through the Toll-like receptor adaptors Trif and MyD88 in bone marrow-derived dendritic cells. Moreover, it exerted a dual role on IL-1 production; on the one hand, it upregulated proIL-1β and proIL-1α levels in a MyD88-dependent manner without activating the inflammasome. On the other hand, it repressed IL-1β secretion induced by alum, a well-known NLRP3 activator. In vivo, OM-85 diminished the recruitment of inflammatory cells in response to peritoneal alum challenge. Our findings therefore suggest that OM-85 favors a protective primed state, while dampening inflammasome activation in specific conditions. Taken together, these data bring new insights into the mechanisms of OM-85 action on innate immune pathways and suggest potential explanations for its efficacy in the treatment of virus-induced airway diseases. PMID:28262817

Anatomy of the human orbital muscle (OM): Features of its detailed topography, syntopy and morphology.

PubMed

Wilden, Andre; Feiser, Janna; Wöhler, Aliona; Isik, Zeynep; Bendella, Habib; Angelov, Doychin N

2017-05-01

The human orbital muscle (OM) is not readily accessible during ordinary anatomical teaching because of insufficient time and difficulties encountered in the preparation. Accordingly, its few anatomical descriptions are supported only by drawings, but not by photographs. The aim of this study was to present OM in dissected anatomic specimens in more detail. Following microscope-assisted dissection, its location, syntopy and morphology were analyzed in 88 orbits of 51 cadavers. Together with the periorbital connective tissue OM filled the infraorbital fissure (IOF) and extended back to the cavernous sinus. As a new finding, we here report that in 34% of the orbits we observed OM-fibers, which proceeded from IOF caudally to the facies infratemporalis of the maxilla. OM had a mean width of 4±1mm, a mean length of 22±5mm and its mean mass was 0.22±0.19g. The subsequent histological analysis of all specimens showed features of smooth muscle tissue: long, spindle-like cells with a centrally located cell nucleus (hematoxylin-eosin staining) which were innervated by tyrosine-hydroxylase immunopositive adrenergic fibers. We conclude that precise knowledge on OM might be very helpful not only to students in medicine and dentistry during anatomical dissection courses, but also to head and neck surgeons, ear-nose-throat specialists and neurosurgeons working in this field. Copyright © 2017 Elsevier GmbH. All rights reserved.

Size- and composition-dependent toxicity of synthetic and soil-derived Fe oxide colloids for the nematode Caenorhabditis elegans.

PubMed

Höss, Sebastian; Fritzsche, Andreas; Meyer, Carolin; Bosch, Julian; Meckenstock, Rainer U; Totsche, Kai Uwe

2015-01-06

Colloidal iron oxides (FeOx) are increasingly released to the environment due to their use in environmental remediation and biomedical applications, potentially harming living organisms. Size and composition could affect the bioavailability and toxicity of such colloids. Therefore, we investigated the toxicity of selected FeOx with variable aggregate size and variably composed FeOx-associated organic matter (OM) toward the nematode Caenorhabditis elegans. Ferrihydrite colloids containing citrate were taken up by C. elegans with the food and accumulated inside their body. The toxicity of ferrihydrite, goethite, and akaganeite was dependent on aggregate size and specific surface area, with EC50 values for reproduction ranging from 4 to 29 mg Fe L(-1). Experiments with mutant strains lacking mitochondrial superoxide dismutase (sod-2) showed oxidative stress for two FeOx and Fe(3+)-ions, however, revealed that it was not the predominant mechanism of toxicity. The OM composition determined the toxicity of mixed OM-FeOx phases on C. elegans. FeOx associated with humic acids or citrate were less toxic than OM-free FeOx. In contrast, soil-derived ferrihydrite, containing proteins and polysaccharides from mobile OM, was even more toxic than OM-free Fh of similar aggregate size. Consequently, the careful choice of the type of FeOx and the type of associated OM may help in reducing the ecological risks if actively applied to the subsurface.

Acute effects of 3G mobile phone radiations on frontal haemodynamics during a cognitive task in teenagers and possible protective value of Om chanting.

PubMed

Bhargav, Hemant; N K, Manjunath; Varambally, Shivarama; Mooventhan, A; Bista, Suman; Singh, Deepeshwar; Chhabra, Harleen; Venkatasubramanian, Ganesan; T M, Srinivasan; H R, Nagendra

2016-06-01

Mobile phone induced electromagnetic field (MPEMF) as well as chanting of Vedic mantra 'OM' has been shown to affect cognition and brain haemodynamics, but findings are still inconclusive. Twenty right-handed healthy teenagers (eight males and 12 females) in the age range of 18.25 ± 0.44 years were randomly divided into four groups: (1) MPONOM (mobile phone 'ON' followed by 'OM' chanting); (2) MPOFOM (mobile phone 'OFF' followed by 'OM' chanting); (3) MPONSS (mobile phone 'ON' followed by 'SS' chanting); and (4) MPOFSS (mobile phone 'OFF' followed by 'SS' chanting). Brain haemodynamics during Stroop task were recorded using a 64-channel fNIRS device at three points of time: (1) baseline, (2) after 30 min of MPON/OF exposure, and (3) after 5 min of OM/SS chanting. RM-ANOVA was applied to perform within- and between-group comparisons, respectively. Between-group analysis revealed that total scores on incongruent Stroop task were significantly better after OM as compared to SS chanting (MPOFOM vs MPOFSS), pre-frontal activation was significantly lesser after OM as compared to SS chanting in channel 13. There was no significant difference between MPON and MPOF conditions for Stroop performance, as well as brain haemodynamics. These findings need confirmation through a larger trial in future.

Sources and distribution of sedimentary organic matter along the Andong salt marsh, Hangzhou Bay

NASA Astrophysics Data System (ADS)

Yuan, Hong-Wei; Chen, Jian-Fang; Ye, Ying; Lou, Zhang-Hua; Jin, Ai-Min; Chen, Xue-Gang; Jiang, Zong-Pei; Lin, Yu-Shih; Chen, Chen-Tung Arthur; Loh, Pei Sun

2017-10-01

Lignin oxidation products, δ13C values, C/N ratios and particle size were used to investigate the sources, distribution and chemical stability of sedimentary organic matter (OM) along the Andong salt marsh located in the southwestern end of Hangzhou Bay, China. Terrestrial OM was highest at the upper marshes and decreased closer to the sea, and the distribution of sedimentary total organic carbon (TOC) was influenced mostly by particle size. Terrestrial OM with a C3 signature was the predominant source of sedimentary OM in the Spartina alterniflora-dominated salt marsh system. This means that aside from contributions from the local marsh plants, the Andong salt marsh received input mostly from the Qiantang River and the Changjiang Estuary. Transect C, which was situated nearer to the Qiantang River mouth, was most likely influenced by input from the Qiantang River. Likewise, a nearby creek could be transporting materials from Hangzhou Bay into Transect A (farther east than Transect C), as Transect A showed a signal resembling that of the Changjiang Estuary. The predominance of terrestrial OM in the Andong salt marsh despite overall reductions in sedimentary and terrestrial OM input from the rivers is most likely due to increased contributions of sedimentary and terrestrial OM from erosion. This study shows that lower salt marsh accretion due to the presence of reservoirs upstream may be counterbalanced by increased erosion from the surrounding coastal areas.

Efficient Filtration of Effluent Organic Matter by Polycation-Clay Composite Sorbents: Effect of Polycation Configuration on Pharmaceutical Removal.

PubMed

Shabtai, Itamar A; Mishael, Yael G

2016-08-02

Hybrid polycation-clay composites, based on methylated poly vinylpyridinium, were optimized as sorbents for secondary effluent organic matter (EfOM) including emerging micropollutants. Composite structure was tuned by solution ionic strength and characterized by zeta potential, FTIR, X-ray diffraction, and thermal gravimetric analyses. An increase in ionic strength induced a transition from a train to a loops and tails configuration, accompanied by greater polycation adsorption. Composite charge reversal (zeta potential -18 to 45 mV) increased the adsorption of EfOM and humic acid (HA), moderately and sharply, respectively, suggesting electrostatic and also nonspecific interactions with EfOM. Filtration of EfOM by columns of positively charged composites was superior to that of granular activated carbon (GAC). The overall removal of EfOM was most efficient by the composite with a train configuration. Whereas a composite with a loops and tails configuration was beneficial for the removal of the anionic micropollutants diclofenac, gemfibrozil and ibuprofen from EfOM. These new findings suggest that the loops and tails may offer unique binding sites for small micropollutants which are overseen by the bulk EfOM. Furthermore, they may explain our previous observations that in the presence of dissolved organic matter, micropollutant filtration by GAC columns was reduced, while their filtration by composite columns remained high.

Numerical simulation of organic waste aerobic biodegradation: a new way to correlate respiration kinetics and organic matter fractionation.

PubMed

Denes, Jeremy; Tremier, Anne; Menasseri-Aubry, Safya; Walter, Christian; Gratteau, Laurette; Barrington, Suzelle

2015-02-01

Composting wastes permits the reuse of organic matter (OM) as agricultural amendments. The fate of OM during composting and the subsequent degradation of composts in soils largely depend on waste OM quality. The proposed study aimed at developing a model to predict the evolution in organic matter quality during the aerobic degradation of organic waste, based on the quantification of the various OM fractions contained in the wastes. The model was calibrated from data gathered during the monitoring of four organic wastes (two non-treated wastes and their digestates) exposed to respirometric tests. The model was successfully fitted for all four wastes and permitted to predict respiration kinetics, expressed as CO2 production rates, and the evolution of OM fractions. The calibrated model demonstrated that hydrolysis rates of OM fractions were similar for all four wastes whereas the parameters related to microbial activity (eg. growth and death rates) were specific to each substrate. These later parameters have been estimated by calibration on respirometric data, thus demonstrating that coupling analyses of OM fractions in initial wastes and respirometric tests permit the simulation of the biodegradation of various type of waste. The biodegradation model presented in this paper could thereafter be integrated in a composting model by implementing mass and heat balance equations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Barrier Properties of Layered-Silicate Reinforced Ethylenepropylenediene Monomer/Chloroprene Rubber Nanorubbers.

PubMed

Wu, Chang Mou; Hsieh, Wen Yen; Cheng, Kuo Bin; Lai, Chiu-Chun; Lee, Kuei Chi

2018-05-09

The triacetin and nitroglycerin barrier properties of layered-silicate reinforced ethylenepropylenediene monomer/chloroprene rubber (EPDM/CR) nanorubbers were investigated as rocket-propellant inhibitors. EPDM/CR nanorubbers with intercalated structures were formulated and prepared by the melt-compounding method. The triacetin permeability and nitroglycerin absorption were observed to decrease with increasing layered-silicate content. The layered silicates also improved the flame retardancies of the nanorubbers by forming silicate reinforced carbonaceous chars. Layered-silicate reinforced EPDM/CR nanorubbers are potentially effective rocket propellant-inhibiting materials.

The Effects of Otitis Media on the Attention Skills of Day-Care-Attending Toddlers.

ERIC Educational Resources Information Center

Feagans, Lynne V.; And Others

1994-01-01

Investigated whether otitis media (OM), middle ear disease, affected toddlers' attention to language. Children were studied during a picture book-reading task at high- or low-quality day-care centers. Children with chronic OM in low-quality care showed the most negative effects on attention during episodes of OM; mothers rated children with…

Chemical, physical and biological factors affecting wood decomposition in forest soils

Treesearch

Martin Jurgensen; Peter Laks; David Reed; Anne Collins; Deborah Page-Dumroese; Douglas Crawford

2004-01-01

Organic matter (OM) decomposition is an important variable in forest productivity and determining the potential of forest soils to sequester atmospheric CO2 (Grigal and Vance 2000; Kimble et al. 2003). Studies using OM from a particular location gives site-specific decomposition information, but differences in OM type and quality make it difficult to compare results...

Development of an Objective Measure to Assess Ego Identity in Adolescence: Validation and Replication.

ERIC Educational Resources Information Center

Grotevant, Harold D., Adams, Gerald R.

1984-01-01

Three studies evaluating the reliability and validity of the Objective Measure of Ego Identity Status (OM-EIS) are reported. Two studies analyzed college students' results from the OM-EIS, the Extended Range Vocabulary Test, the Crowne-Marlowe Social Disability Scale and achievement records. Study 3 correlated high school seniors' OM-EIS scores…

Rice husk ash (RHA) as a partial cement replacement in modifying peat soil properties

NASA Astrophysics Data System (ADS)

Daud, Nik Norsyahariati Nik; Daud, Mohd Nazrin Mohd; Muhammed, Abubakar Sadiq

2018-02-01

This paper describes the effect of rice husk ash (RHA) and ordinary Portland cement (OPC) as a potential binder for modifying the properties of peat soil. The amounts RHA and OPC added to the peat soil sample, as percentage of the dry soil mass were in the range of 10-15% and 15%, respectively. Observations were made for the changes in the properties of the soil such as maximum dry density (MDD), optimum moisture content (OMC) and shear strength. Scanning Electron Micrograph-Energy Dispersive X-Ray (SEM-EDX) test were also conducted to observe the microstructure of treated and untreated peat soil. The results show that the modified soil of MDD and OMC values are increased due to the increment amount of binder material. Shear strength values of modified peat showing a good result by assuming that it is relative to the formation of major reaction products such as calcium silicate hydrate (C-S-H). The presence of C-S-H formation is indicated by the results produced from microstructural analysis of peat before and after modification process. This depicts the potential usage of RHA as a partial cement replacement in peat soil which is also improving its engineering properties.

Raining a magma ocean: Thermodynamics of rocky planets after a giant impact

NASA Astrophysics Data System (ADS)

Stewart, S. T.; Lock, S. J.; Caracas, R.

2017-12-01

Rocky planets in exoplanetary systems have equilibrium temperatures up to a few 1000 K. The thermal evolution after a giant impact is sensitive to the equilibrium temperature. Post-impact rocky bodies are thermally stratified, with cooler, lower-entropy silicate overlain by vaporized, higher-entropy silicate. The radii of impact-vaporized rocky planets are much larger than the radii of equivalent condensed bodies. Furthermore, after some high-energy, high-angular momentum collisions, the post-impact body exceeds the corotation limit for a rocky planet and forms a synestia. Initially, volatiles and silicates are miscible at the high temperatures of the outer layer. If the equilibrium temperature with the star is lower than the silicate condensation temperature ( 2000 K), silicate droplets form at the photosphere and fall while volatile components remain in the vapor. Radiation and turbulent convection cool the vapor outer layer to the silicate vapor curve. A distinct magma ocean forms as the thermal profile crosses the silicate vapor curve and the critical curves for the volatiles. Near the temperatures and pressures of the critical curves, volatiles and silicates are partially soluble in each other. As the system continues cooling, the volatile vapor and silicate liquid separate toward the end member compositions, which are determined by the equilibrium temperature and the total vapor pressure of volatiles. If the equilibrium temperature with the star is near or above the condensation temperature for silicates, there would be limited condensation at the photosphere. Initially, the cooler lower mantle would slowly, diffusively equilibrate with the hotter upper mantle. In some cases, the thermal profile may cross the silicate vapor curve in the middle of the silicate layer, producing a silicate rain layer within the body. With continued evolution toward an adiabatic thermal profile, the body would separate into a silicate liquid layer underlying a silicate-volatile vapor layer. As the hottest rocky planets become tidally locked to their star, cooling progresses asymmetrically. The timing and degree of differentiation of rocky planets into silicate mantles and volatile atmospheres depends on the thermal evolution of vaporized rocky planets and may vary widely with equilibrium temperature.

Priming of native soil organic matter by pyrogenic organic matter

NASA Astrophysics Data System (ADS)

DeCiucies, Silene; Dharmakeerthi, Saman; Whitman, Thea; Woolf, Dominic; Lehmann, Johannes

2015-04-01

Priming, in relation to pyrogenic organic matter (PyOM), describes the change in mineralization rate of non-pyrogenic ("native") soil organic matter (nSOM) due to the addition of PyOM. Priming may be 'positive', in that the addition of pyC increases the mineralization rate of native SOM, or 'negative', in that the mineralization rate of nSOM is decreased. Reasons for increased mineralization may include: (i) co-metabolism: microbial decomposition of labile C-additions increases microbial activity, and facilitates additional decomposition of npSOC by active enzymes; (ii) stimulation: substrate additions result in lifted pH, nutrient, oxygen, or water constraints resulting in increased microbial activity. Decreased mineralization may be a result of: (i) inhibition: the opposite of stimulation whereby constraints are aggravated by substrate addition. Substrate addition may also cause inhibition by interfering with enzymes or signaling compounds; (ii) preferential substrate utilization: labile fraction of PyOM additions are preferentially used up by microbes thus causing a decrease in nSOC decomposition; (iii) sorption: organic compounds are adsorbed onto PyOM surfaces, decreasing their rate of mineralization; (iv) stabilization: formation of organo-mineral associations forms stable SOC pools. We have conducted a suite of experiments to investigate these potential interactions. In a seven year long incubation study, PyOM additions increased total OM mineralization for the first 2.5 years, was equal to control after 6.2 years, and was 3% lower after 7.1 years. Cumulative nSOM mineralization was 23% less with the PyOM additions than without, and over 60% of the added PyOM was present in the labile soil fraction after the 7.1 year incubation. Two additional incubation studies, one with and without plants, showed greater nSOM mineralization in the short term and lower nSOM mineralization over the long term. Increased nSOC mineralization due to the presence of plants was counteracted by PyOM additions. However, repeated additions of crop residues over seven years did not result in lower mineralization of the residue and nSOM. We have also determined that, although there is no optimal duration for pre-incubation of soil before SOC studies, the type of carbon available is crucial in determining the effects of PyOM additions. We will continue to examine the contribution of the different mechanisms by isolating variables such as nutrient addition, soil texture, and mineral availability. We anticipate that sorption on PyOM surfaces are important in nSOM stabilization and will continue to study these effects using highly labeled substrates and nano secondary ion mass spectrometry (nano-SIMS).

Prescription Omega-3 Fatty Acid Products and Dietary Supplements Are Not Interchangeable.

PubMed

Hilleman, Daniel; Smer, Aiman

2016-01-01

To provide an overview of prescription and dietary supplement omega-3 fatty acid (OM3-FA) products and considerations for clinical use. Narrative review. The PubMed database was searched for cardiovascular-related investigations focused on eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA) (limit: English-only articles). Additional regulatory information on prescription and dietary supplements was obtained from United States Food and Drug Administration online sources. Prescription QM3-FA products are supported by robust clinical development and safety monitoring programs, whereas dietary supplements are not required to demonstrate safety or efficacy prior to marketing. There are no over-the-counter OM3-FA products available in the United States. Investigations of OM3-FA dietary supplements show that quantities of EPA and DHA are highly variable within and between brands. Dietary supplements also may contain potentially harmful components, including oxidized OM3-FA, other lipids, cholesterol, and toxins. Prescription OM3-FA products may contain DHA and EPA or EPA alone. All prescription OM3-FA products have demonstrated statistically significant triglyceride reduction as monotherapy or in combination with statins in patients with hypertriglyceridemia. Differential effects between products containing EPA and DHA compared with a high-purity EPA product (icosapent ethyl) have clinical implications: Increases in low-density lipoprotein cholesterol associated with DHA have the potential to confound strategies for managing patients with dyslipidemia. Cardiovascular outcomes studies of prescription CM3-FA products are ongoing. OM3-FA dietary supplements should not be substituted for prescription products, and prescription OM3-FA products that contain DHA are not equivalent to or interchangeable with high-purity EPA (icosapent ethyl) and should not be substituted for it.

Use of OM-85 BV in children suffering from recurrent respiratory tract infections and subnormal IgG subclass levels.

PubMed

Del-Río-Navarro, B E; Luis Sienra-Monge, J J; Berber, A; Torres-Alcántara, S; Avila-Castañón, L; Gómez-Barreto, D

2003-01-01

Recurrent acute respiratory tract infections (RARTIs) in children are related to IgG subclass deficiencies. The aim of the trial was to evaluate the effect of OM-85 BV in the number of RARTIs as well as in the IgG subclass levels. This was a randomized, double-blind, placebo-controlled clinical trial. Patients of ages three to six years, having three or more documented ARTIs during the last six months with subnormal IgG subclass levels were included. Patients took either one capsule of OM-85 BV (3.5 mg) or placebo orally every day for ten consecutive days per month during three consecutive months. Patients were followed three further months without drug intake. IgG subclass levels were determined before and after treatment. IgG4 levels diminished after the OM-85 BV treatment (-3 [-8.0, -1.0] median difference [95 % CI] p < 0.05 by Wilcoxon test). No other significant changes in IgG subclasses were observed. After six months the patients in the OM-85 BV group (n = 20) experienced 2.8 1.4 (mean SD) ARTIs, while the patients in the placebo group (n = 20) suffered 5.2 1.5 ARTIs (-2.4 [3.3, -1.5] mean difference [95 % CI] p < 0.001 by Student's t test). Three patients with OM-85 BV had gastrointestinal events related to drug administration, as well as three placebo patients. This study demonstrated the clinical benefit of OM-85 BV in patients suffering from RARTIs and subnormal levels of IgG subclasses. This trial opens new perspectives in the research of the mechanism of action of OM-85 BV.

Seasonal changes of organic matter quality and quantity at the outlet of a forested karst system (La Roche Saint Alban, French Alps)

NASA Astrophysics Data System (ADS)

Tissier, Grégory; Perrette, Yves; Dzikowski, Marc; Poulenard, Jérome; Hobléa, Fabien; Malet, Emmanuel; Fanget, Bernard

2013-03-01

SummaryBecause of its impact on water quality, organic matter (OM) in karst groundwater has been widely studied. The present article describes a method for monitoring OM in karst aquifers characterized by quick responses to rainfall. This method combines weekly manual sampling and continuous monitoring to provide, qualitative and quantitative information about OM flow. Weekly samples were analyzed for Total Organic Carbon (TOC) content and spectrofluorescence, while continuous monitoring was carried out at the main spring, using a field fluorimeter (310/400-700 nm and 280/300-600 nm) to quantify chromophoric organic matter (COM). The type and quantity of COM were defined by decomposing Excitation Emission Matrices (EEMs) and by applying a 2D fluorescence decomposition method. Continuous monitoring data showed that the dominant COM was humic-like (HL). We found three types of relationship between HL and discharge and between HL and TOC, showing that caution must be exercised when using field fluorimeter measurements to quantify TOC. Each relationship was characterized by global differences in OM content and by the presence of different percentages of non-chromophoric organic matter. These three relationships are associated with changes in hydrology and microorganism activity during the year. We used these relationships to estimate the annual OM flow (about 15 kg/ha/year) and thereby quantify OM flow during the year. Our results show the importance of the non-chromophoric organic matter in such estimation. That work illustrates the need to couple qualitative and quantitative monitoring of OM in karst spring to improve the global comprehension of karst system and of the sources implies in the OM flow.

Nitrogen-rich microbial products provide new organo-mineral associations for the stabilization of soil organic matter.

PubMed

Kopittke, Peter M; Hernandez-Soriano, Maria C; Dalal, Ram C; Finn, Damien; Menzies, Neal W; Hoeschen, Carmen; Mueller, Carsten W

2018-04-01

Understanding the cycling of C and N in soils is important for maintaining soil fertility while also decreasing greenhouse gas emissions, but much remains unknown about how organic matter (OM) is stabilized in soils. We used nano-scale secondary ion mass spectrometry (NanoSIMS) to investigate the changes in C and N in a Vertisol and an Alfisol incubated for 365 days with 13 C and 15 N pulse labeled lucerne (Medicago sativa L.) to discriminate new inputs of OM from the existing soil OM. We found that almost all OM within the free stable microaggregates of the soil was associated with mineral particles, emphasizing the importance of organo-mineral interactions for the stabilization of C. Of particular importance, it was also found that 15 N-rich microbial products originating from decomposition often sorbed directly to mineral surfaces not previously associated with OM. Thus, we have shown that N-rich microbial products preferentially attach to distinct areas of mineral surfaces compared to C-dominated moieties, demonstrating the ability of soils to store additional OM in newly formed organo-mineral associations on previously OM-free mineral surfaces. Furthermore, differences in 15 N enrichment were observed between the Vertisol and Alfisol presumably due to differences in mineralogy (smectite-dominated compared to kaolinite-dominated), demonstrating the importance of mineralogy in regulating the sorption of microbial products. Overall, our findings have important implications for the fundamental understanding of OM cycling in soils, including the immobilization and storage of N-rich compounds derived from microbial decomposition and subsequent N mineralization to sustain plant growth. © 2017 John Wiley & Sons Ltd.

Amphiphilic block-graft copolymer templates for organized mesoporous TiO2 films in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Lim, Jung Yup; Lee, Chang Soo; Lee, Jung Min; Ahn, Joonmo; Cho, Hyung Hee; Kim, Jong Hak

2016-01-01

Amphiphilic block-graft copolymers composed of poly(styrene-b-butadiene-b-styrene) (SBS) backbone and poly(oxyethylene methacrylate) (POEM) side chains are synthesized and combined with hydrophilically preformed TiO2 (Pre-TiO2), which works as a structural binder as well as titania source. This results in the formation of crack free, 6-μm-thick, organized mesoporous TiO2 (OM-TiO2) films via one-step doctor-blading based on self-assembly of SBS-g-POEM as well as preferential interaction of POEM chains with Pre-TiO2. SBS-g-POEM with different numbers of ethylene oxide repeating units, SBS-g-POEM(500) and SBS-g-POEM(950), are used to form OM-TiO2(500) and OM-TiO2(950), respectively. The efficiencies of dye-sensitized solar cells (DSSCs) with a quasi-solid-state polymer electrolyte reach 5.7% and 5.8% at 100 mW/cm2 for OM-TiO2(500) and OM-TiO2(950), respectively. The surface area of OM-TiO2(950) was greater than that of OM-TiO2(500) but the light reflectance was lower in the former, which is responsible for similar efficiency. Both DSSCs exhibit much higher efficiency than one (4.8%) with randomly-organized particulate TiO2 (Ran-TiO2), which is attributed to the higher dye loading, reduced charge recombination and improved pore infiltration of OM-TiO2. When utilizing poly((1-(4-ethenylphenyl)methyl)-3-butyl-imidazolium iodide) (PEBII) and mesoporous TiO2 spheres as the solid electrolyte and the scattering layer, the efficiency increases up to 7.5%, one of the highest values for N719-based solid-state DSSCs.

Cost analysis of nonoperative management of acute appendicitis in children.

PubMed

Mudri, Martina; Coriolano, Kamary; Bütter, Andreana

2017-05-01

The purpose of this study was to determine if nonoperative management of acute appendicitis in children is more cost effective than appendectomy. A retrospective review of children (6-17years) with acute appendicitis treated nonoperatively (NOM) from May 2012 to May 2015 was compared to similar patients treated with laparoscopic appendectomy (OM) (IRB#107535). Inclusion criteria included symptoms ≤48h, localized peritonitis, and ultrasound confirmation of acute appendicitis. Variables analyzed included failure rates, complications, length of stay (LOS), and cost analysis. 26 NOM patients (30% female, mean age 12) and 26 OM patients (73% female, mean age 11) had similar median initial LOS (24.5h (NOM) vs 16.5h (OM), p=0.076). Median total LOS was significantly longer in the NOM group (34.5h (NOM) vs 17.5 (OM), p=0.01). Median cost of appendectomy was $1416.14 (range $781.24-$2729.97). 9/26 (35%) NOM patients underwent appendectomy for recurrent appendicitis. 4/26 (15%) OM patients were readmitted (postoperative abscess (n=2), Clostridium difficile colitis (n=1), postoperative nausea/vomiting (n=1)). Median initial hospital admission costs were significantly higher in the OM group ($3502.70 (OM) vs $1870.37 (NOM), p=0.004)). However, median total hospital costs were similar for both groups ($3708.68 (OM) vs $2698.99 (NOM), p=0.065)). Although initial costs were significantly less in children with acute appendicitis managed nonoperatively, total costs were similar for both groups. The high failure rate of nonoperative management in this series contributed to the total increased cost in the NOM group. 3b. Copyright © 2017 Elsevier Inc. All rights reserved.

A bacterial extract of OM-85 Broncho-Vaxom prevents allergic rhinitis in mice.

PubMed

Han, Ling; Zheng, Chao-Pan; Sun, Yue-Qi; Xu, Geng; Wen, Weiping; Fu, Qing-Ling

2014-01-01

According to the hygiene hypothesis, bacterial infections during early life contribute to a reduced incidence of asthma in animals. However, the effects of microbial products at a safe dose and within a rational time course on the prevention of allergic rhinitis (AR) have been inconclusive. This study investigated the immunomodulatory effects of oral administration of a bacterial extract, OM-85 Broncho-Vaxom (BV), with a low dose and general time course, which is currently used for respiratory infections in humans, on AR inflammation in mice. We developed a mouse model of ovalbumin (OVA)-induced AR allergic inflammation in the nose mucosa of mice. Low doses of OM-85 BV were orally administered for 3 months (long term) before sensitization. We evaluated nasal symptoms, pathology in the nose, inflammatory cells, and the levels of T helper 1 (Th1)/Th2 cytokines in the nasal lavage fluids, and the serum levels of specific IgE and IgG1. We also observed enhanced effects of OM-85 BV with 1 month (short term) of treatment. We found that long-term pretreatment with OM-85 BV protected the mice from the majority of allergy-specific symptoms; specifically, OM-85 BV suppressed nasal symptoms, inhibited eosinophil infiltration in the nose, inhibited inflammatory infiltrates and the Th2 response by reducing cytokines (IL-4, IL-5, or IL-13) in the nasal lavage fluids, and reduced IgE and IgG1 levels. Furthermore, short-term treatment with OM-85 BV decreased the levels of Th2 cytokines and IgE. Taken together, our data suggested that OM-85 BV is a low-cost alternative candidate to prevent AR with simple oral administration.

A bacterial extract of OM-85 Broncho-Vaxom prevents allergic rhinitis in mice.

PubMed

Han, L; Zheng, C-P; Sun, Y-Q; Xu, G; Wen, W; Fu, Q-L

2013-12-06

According to the hygiene hypothesis, bacterial infections during early life contribute to a reduced incidence of asthma in animals. However, the effects of microbial products at a safe dose and within a rational time course on the prevention of allergic rhinitis (AR) have been inconclusive. This study investigated the immunomodulatory effects of oral administration of a bacterial extract, OM-85 Broncho-Vaxom (BV), with a low dose and general time course, which is currently used for respiratory infections in humans, on AR inflammation in mice. We developed a mouse model of ovalbumin (OVA)-induced AR allergic inflammation in the nose mucosa of mice. Low doses of OM-85 BV were orally administered for 3 months (long term) before sensitization. We evaluated nasal symptoms, pathology in the nose, inflammatory cells, and the levels of T helper 1 (Th1)/Th2 cytokines in the nasal lavage fluids, and the serum levels of specific IgE and IgG1. We also observed enhanced effects of OM-85BV with 1 month (short term) of treatment. We found that long-term pretreatment with OM-85 BV protected the mice from the majority of allergy-specific symptoms; specifically, OM-85 BV suppressed nasal symptoms, inhibited eosinophil infiltration in the nose, inhibited inflammatory infiltrates and the Th2 response by reducing cytokines (IL-4, IL-5, or IL-13) in the nasal lavage fluids, and reduced IgE and IgG1 levels. Furthermore, short-term treatment with OM-85 BV decreased the levels of Th2 cytokines and IgE. Taken together, our data suggested that OM-85 BV is a low-cost alternative candidate to prevent AR with simple oral administration.

[Sagittal otolith morphology and the relationship between its mass and the age of Liza haematocheila in the Yangtze Estuary, China].

PubMed

Ji, Yan; Zhao, Feng; Yang, Qin; Ma, Rong Rong; Yang, Gang; Zhang, Tao; Zhuang, Ping

2018-03-01

To examine the relationship of morphological characters of sagittal otolith and the age of Liza haematocheila in the Yangtze Estuary, we analyzed the morphological parameters of 324 pairs of otoliths extracted from 358 L. haematocheila specimens from the Yangtze Estuary in February to June of 2017. The results showed that sagittal otolith had rostrum, antirostrum and obvious central notch. The size and shape of sagittal otolith significantly changed with their growth, from regular melon seeds shape outline to long narrow leaf shape and increasing irregular wavy outline. The average density of sagittal otolith was 1.52 mg·mm -2 . The average rectangularity was 0.68. The length of sagittal otolith was 0.021%-0.047% of entire body length (BL), the width was 0.009%-0.021% of entire BL, and the mass was 0.045‰-0.731‰ of the entire body mass (BM). Otolith length (OL), otolith width (OW) and otolith mass (OM) were all significantly related to the BL, with the determination coefficient for OW and OM model being the highest (R 2 =0.928). The relationship between OM and BL was described best by exponential regression: OM=0.0009BL 1.8737 (R 2 =0.967). The relationships between OM and age (A), BL and A were well fitted by multinomial regressions, respectively: OM=2.9262A 2 +4.8437A+2.1894 (R 2 =0.847), BL=-3.2248A 2 +102.54A+38.373 (R 2 =0.858). In addition, OM was linearly correlated with A. The estimated otolith's ages from the model did not significantly variate from the real ages counting from annulus counts. Therefore, OM could be an effective parameter for the age estimation of L. haematocheila.

Involvement of Epidermal Growth Factor Receptor Signaling in Estrogen Inhibition of Oocyte Maturation Mediated Through the G Protein-Coupled Estrogen Receptor (Gper) in Zebrafish (Danio rerio)1

PubMed Central

Peyton, Candace; Thomas, Peter

2011-01-01

Oocyte maturation (OM) in teleosts is under precise hormonal control by progestins and estrogens. We show here that estrogens activate an epidermal growth factor receptor (Egfr) signaling pathway in fully grown, denuded zebrafish (Danio rerio) oocytes through the G protein-coupled estrogen receptor (Gper; also known as GPR30) to maintain oocyte meiotic arrest in a germinal vesicle breakdown (GVBD) bioassay. A GPER-specific antagonist, G-15, increased spontaneous OM, indicating that the inhibitory estrogen actions on OM are mediated through Gper. Estradiol-17beta-bovine serum albumin, which cannot enter oocytes, decreased GVBD, whereas treatment with actinomycin D did not block estrogen's inhibitory effects, suggesting that estrogens act at the cell surface via a nongenomic mechanism to prevent OM. The intracellular tyrosine kinase (Src) inhibitor, PP2, blocked estrogen inhibition of OM. Expression of egfr mRNA and Egfr protein were detected in denuded zebrafish oocytes. The matrix metalloproteinase (MMP) inhibitor, ilomastat, which prevents the release of heparin-bound epidermal growth factor, increased spontaneous OM, whereas the MMP activator, interleukin-1alpha, decreased spontaneous OM. Moreover, inhibitors of EGFR (ErbB1) and extracellular-related kinase 1 and 2 (Erk1/2; official symbol Mapk3/1) increased spontaneous OM. In addition, estradiol-17beta and the GPER agonist, G-1, increased phosphorylation of Erk, and this was abrogated by simultaneous treatment with the EGFR inhibitor. Taken together, these results suggest that estrogens act through Gper to maintain meiotic arrest via an Src kinase-dependent G-protein betagamma subunit signaling pathway involving transactivation of egfr and phosphorylation of Mapk3/1. To our knowledge, this is the first evidence that EGFR signaling in vertebrate oocytes can prevent meiotic progression. PMID:21349822

Estimated contributions of primary and secondary organic aerosol from fossil fuel combustion during the CalNex and Cal-Mex campaigns

NASA Astrophysics Data System (ADS)

Guzman-Morales, J.; Frossard, A. A.; Corrigan, A. L.; Russell, L. M.; Liu, S.; Takahama, S.; Taylor, J. W.; Allan, J.; Coe, H.; Zhao, Y.; Goldstein, A. H.

2014-05-01

Observations during CalNex and Cal-Mex field campaigns at Bakersfield, Pasadena, Tijuana, and on board the R/V Atlantis show a substantial contribution of fossil fuel emissions to the ambient particle organic mass (OM). At least two fossil fuel combustion (FFC) factors with a range of contributions of oxidized organic functional groups were identified at each site and accounted for 60-88% of the total OM. Additional marine, vegetative detritus, and biomass burning or biogenic sources contribute up to 40% of the OM. Comparison of the FTIR spectra of four different unburned fossil fuels (gasoline, diesel, motor oil, and ship diesel) with PMF factors from ambient samples shows absorbance peaks from the fuels are retained in organic aerosols, with the spectra of all of the FFC factors containing at least three of the four characteristic alkane peaks observed in fuel standards at 2954, 2923, 2869 and 2855 cm-1. Based on this spectral similarity, we estimate the primary OM from FFC sources for each site to be 16-20%, with secondary FFC OM accounting for an additional 42-62%. Two other methods for estimating primary OM that use carbon monoxide (CO) and elemental carbon (EC) as tracers of primary organic mass were investigated, but both approaches were problematic for the CalNex and Cal-Mex urban sites because they were influenced by multiple emission sources that had site-specific and variable initial ratios to OM. For example, using the ΔPOM/ΔCO ratio of 0.0094 μg ppb V-1 proposed by other studies produces unrealistically high estimates of primary FFC OM of 55-100%.

Pre-operative assessment of residual disease in locally advanced breast cancer patients: A sequential study by quantitative diffusion weighted MRI as a function of therapy.

PubMed

Agarwal, Khushbu; Sharma, Uma; Sah, Rani G; Mathur, Sandeep; Hari, Smriti; Seenu, Vurthaluru; Parshad, Rajinder; Jagannathan, Naranamangalam R

2017-10-01

The potential of diffusion weighted imaging (DWI) in assessing pathologic response and surgical margins in locally advanced breast cancer patients (n=38) undergoing neoadjuvant chemotherapy was investigated. DWI was performed at pre-therapy (Tp0), after I (Tp1) and III (Tp3) NACT at 1.5T. Apparent diffusion coefficient (ADC) of whole tumor (ADC WT ), solid tumor (ADC ST ), intra-tumoral necrosis (ADC Nec ) was determined. Further, ADC of 6 consecutive shells (5mm thickness each) including tumor margin to outside tumor margins (OM1 to OM5) was calculated and the data analyzed to define surgical margins. Of 38 patients, 6 were pathological complete responders (pCR), 19 partial responders (pPR) and 13 were non-responders (pNR). Significant increase was observed in ADC ST and ADC WT in pCR and pPR following therapy. Pre-therapy ADC was significantly lower in pCR compared to pPR and pNR indicating the heterogeneous nature of tumor which may affect drug perfusion and consequently the response. ADC of outside margins (OM1, OM2, and OM3) was significantly different among pCR, pPR and pNR at Tp3 which may serve as response predictive parameter. Further, at Tp3, ADC of outside margins (OM1, OM2, and OM3) was significantly lower compared to that seen at Tp0 in pCR, indicating the presence of residual disease in these shells. Pre-surgery information may serve as a guide to define cancer free margins and the extent of residual disease which may be useful in planning breast conservation surgery. Copyright © 2017 Elsevier Inc. All rights reserved.

Contribution of bacterial cells to lacustrine organic matter based on amino sugars and D-amino acids

NASA Astrophysics Data System (ADS)

Carstens, Dörte; Köllner, Krista E.; Bürgmann, Helmut; Wehrli, Bernhard; Schubert, Carsten J.

2012-07-01

Amino sugars (ASs), D-amino acids (D-AAs), and bacterial cell counts were measured in two Swiss lakes to study the contribution of bacterial cells to organic matter (OM) and the fate of ASs and bacterial amino biomarkers during OM degradation. Concentrations of individual ASs (glucosamine, galactosamine, muramic acid, and mannosamine) in the particulate and total OM pools were analyzed in water-column profiles of Lake Brienz (oligotrophic and oxic throughout the entire water column) and Lake Zug (eutrophic, stratified, and permanently anoxic below 170 m) in spring and in fall. Generally, carbon-normalized AS concentrations decreased with water depth, indicating the preferential decomposition of ASs. For Lake Brienz the relative loss of particulate ASs was higher than in Lake Zug, suggesting enhanced AS turnover in an oligotrophic environment. AS ratio changes in the water column revealed a replacement of plankton biomass with OM from heterotrophic microorganisms with increasing water depth. Similar to the ASs, highest carbon normalized D-AA concentrations were found in the upper water column with decreasing concentrations with depth and an increase close to the sediments. In Lake Zug, an increase in the percentage of D-AAs also showed the involvement of bacteria in OM degradation. Estimations of OM derived from bacterial cells using cell counts and the bacterial biomarkers muramic acid and D-AAs gave similar results. For Lake Brienz 0.2-14% of the organic carbon pool originated from bacterial cells, compared to only 0.1-5% in Lake Zug. Based on our estimates, muramic acid appeared primarily associated with bacterial biomass and not with refractory bacterial necromass. Our study underscores that bacteria are not only important drivers of OM degradation in lacustrine systems, they also represent a significant source of OM themselves, especially in oligotrophic lakes.

Involvement of epidermal growth factor receptor signaling in estrogen inhibition of oocyte maturation mediated through the G protein-coupled estrogen receptor (Gper) in zebrafish (Danio rerio).

PubMed

Peyton, Candace; Thomas, Peter

2011-07-01

Oocyte maturation (OM) in teleosts is under precise hormonal control by progestins and estrogens. We show here that estrogens activate an epidermal growth factor receptor (Egfr) signaling pathway in fully grown, denuded zebrafish (Danio rerio) oocytes through the G protein-coupled estrogen receptor (Gper; also known as GPR30) to maintain oocyte meiotic arrest in a germinal vesicle breakdown (GVBD) bioassay. A GPER-specific antagonist, G-15, increased spontaneous OM, indicating that the inhibitory estrogen actions on OM are mediated through Gper. Estradiol-17beta-bovine serum albumin, which cannot enter oocytes, decreased GVBD, whereas treatment with actinomycin D did not block estrogen's inhibitory effects, suggesting that estrogens act at the cell surface via a nongenomic mechanism to prevent OM. The intracellular tyrosine kinase (Src) inhibitor, PP2, blocked estrogen inhibition of OM. Expression of egfr mRNA and Egfr protein were detected in denuded zebrafish oocytes. The matrix metalloproteinase (MMP) inhibitor, ilomastat, which prevents the release of heparin-bound epidermal growth factor, increased spontaneous OM, whereas the MMP activator, interleukin-1alpha, decreased spontaneous OM. Moreover, inhibitors of EGFR (ErbB1) and extracellular-related kinase 1 and 2 (Erk1/2; official symbol Mapk3/1) increased spontaneous OM. In addition, estradiol-17beta and the GPER agonist, G-1, increased phosphorylation of Erk, and this was abrogated by simultaneous treatment with the EGFR inhibitor. Taken together, these results suggest that estrogens act through Gper to maintain meiotic arrest via an Src kinase-dependent G-protein betagamma subunit signaling pathway involving transactivation of egfr and phosphorylation of Mapk3/1. To our knowledge, this is the first evidence that EGFR signaling in vertebrate oocytes can prevent meiotic progression.

Effect of temperature on hydration kinetics and polymerization of tricalcium silicate in stirred suspensions of CaO-saturated solutions

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

Grant, Steven A.; Boitnott, Ginger E.; Korhonen, Charles J.

2006-04-15

Tricalcium silicate was hydrated at 274, 278, 283, 298, and 313 K in stirred suspensions of saturated CaO solutions under a nitrogen-gas atmosphere until the end of deceleratory period. The suspension conductivities and energy flows were measured continuously. The individual reaction rates for tricalcium silicate dissolution, calcium silicate hydrate precipitation, and calcium hydroxide precipitation were calculated from these measurements. The results suggest that the proportion of tricalcium silicate dissolved was determined by the rate of tricalcium silicate dissolution and the time to very rapid calcium hydroxide precipitation. The time to very rapid calcium hydroxide precipitation was more sensitive to changesmore » in temperature than was the rate of tricalcium silicate dissolution, so that the proportion of tricalcium silicate hydration dissolved by the deceleratory period increased with decreasing temperature. The average chain length of the calcium silicate hydrate ascertained by magic-angle spinning nuclear magnetic resonance spectroscopy increased with increasing temperature.« less

A Best Practice for Developing Availability Guarantee Language in Photovoltaic (PV) O&M Agreements.

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

Klise, Geoffrey Taylor; Balfour, John

This document outlines the foundation for developing language that can be utilized in an Equipment Availability Guarantee, typically included in an O&M services agreement between a PV system or plant owner and an O&M services provider, or operator. Many of the current PV O&M service agreement Availability Guarantees are based on contracts used for traditional power generation, which create challenges for owners and operators due to the variable nature of grid-tied photovoltaic generating technologies. This report documents language used in early PV availability guarantees and presents best practices and equations that can be used to more openly communicate how themore » reliability of the PV system and plant equipment can be expressed in an availability guarantee. This work will improve the bankability of PV systems by providing greater transparency into the equipment reliability state to all parties involved in an O&M services contract.« less

Interleukin 10 is an essential modulator of mucoid metaplasia in a mouse otitis media model

PubMed Central

Tsuchiya, Katsuyuki; Komori, Masahiro; Zheng, Qing Yin; Ferrieri, Patricia; Lin, Jizhen

2009-01-01

Inflammatory cytokines are involved in the development of mucus cell metaplasia/hyperplasia (MCM) in otitis media (OM). However, which cytokines play an essential role in MCM OM is not clear at the moment. In this study, we hypothesized that interleukin-10 (IL-10) played an indispensable role in MCM of bacterial OM and used IL-10 knockout mice to test this hypothesis. In wild-type mice, both S. pneumoniae and H. influenzae triggered the development of MCM in the middle ear mucosa. In IL-10 knockout mice, the number of goblet cells and mucin-producing cells in the middle ear was significantly reduced after bacterial middle ear infection compared with that in wild-type mice. We, therefore, concluded that IL-10 plays an essential role in MCM of bacterial OM. IL-10 is a potential target for the treatment of MCM in OM. PMID:18771082

Development of terahertz otoscope for diagnosing otitis media (Conference Presentation)

NASA Astrophysics Data System (ADS)

Jeon, Tae-In; Ji, Young Bin; Bark, Hyeon Sang; Noh, Sam Kyu; Oh, Seung Jae

2017-03-01

A novel terahertz (THz) otoscope is designed and fabricated to help physicians to diagnose otitis media (OM) with both THz diagnostics and conventional optical diagnostics. The inclusion of indium tin oxide (ITO) glass in the THz otoscope allows physicians to diagnose OM with both THz and conventional optical diagnostics. To determine THz diagnostics for OM, we observed reflection signals from samples behind a thin dielectric film and found that the presence of water behind the membrane could be distinguished based on THz pulse shape. We verified the potential of this tool for diagnosing OM using mouse skin tissue and a human tympanic membrane samples prior to clinical application. The presence of water absorbed by the human membrane was easily distinguished based on differences in pulse shapes and peak-to-peak amplitudes of reflected THz pulses. The potential for early OM diagnosis using the THz otoscope was confirmed by alteration of THz pulse depending on water absorption level.

A comparison of the costs of laparoscopic myomectomy and open myomectomy at a teaching hospital in southern Taiwan.

PubMed

Chang, Chi-Chang

2013-06-01

To compare the costs of traditional open myomectomy (OM) with laparoscopic myomectomy (LM). A retrospective review was conducted of the medical records of 155 women who underwent traditional open myomectomy (OM) or laparoscopic myomectomy (LM) in a teaching hospital in Taiwan. The total medical service expense and the patient out-of-pocket expense were significantly higher for women who received LM than for women who received OM. However, the operative time and blood loss during surgery were significantly less in women who received LM than in women who received OM. The overall expense is higher for LM than for OM; however, the laparoscopic approach has numerous advantages for patients, including shorter operative time, less blood loss, and a more rapid recovery time. No difference existed in the rate of complications or in the recurrence of disease for the two procedures. Copyright © 2013. Published by Elsevier B.V.

Organic matter content and particle size modifications in mangrove sediments as responses to sea level rise.

PubMed

Sanders, Christian J; Smoak, Joseph M; Waters, Mathew N; Sanders, Luciana M; Brandini, Nilva; Patchineelam, Sambasiva R

2012-06-01

Mangroves sediments contain large reservoirs of organic material (OM) as mangrove ecosystems produce large quantities and rapidly burial OM. Sediment accumulation rates of approximately 2.0 mm year(-1), based on (210)Pb(ex) dating, were estimated at the margin of two well-developed mangrove forest in southern Brazil. Regional data point to a relative sea level (RSL) rise of up to ∼4.0 mm year(-1). This RSL rise in turn, may directly influence the origin and quantity of organic matter (OM) deposited along mangrove sediments. Lithostratigraphic changes show that sand deposition is replacing the mud (<63 μm) fraction and OM content is decreasing in successively younger sediments. Sediment accumulation in coastal areas that are not keeping pace with sea level rise is potentially conducive to the observed shifts in particle size and OM content. Copyright © 2012 Elsevier Ltd. All rights reserved.

In vitro effects of two silicate-based materials, Biodentine and BioRoot RCS, on dental pulp stem cells in models of reactionary and reparative dentinogenesis

PubMed Central

Loison-Robert, Ludwig Stanislas; Berbar, Tsouria; Isaac, Juliane; Berdal, Ariane; Simon, Stéphane

2018-01-01

Background Calcium silicate-based cements are biomaterials with calcium oxide and carbonate filler additives. Their properties are close to those of dentin, making them useful in restorative dentistry and endodontics. The aim of this study was to evaluate the in vitro biological effects of two such calcium silicate cements, Biodentine (BD) and Bioroot (BR), on dental stem cells in both direct and indirect contact models. The two models used aimed to mimic reparative dentin formation (direct contact) and reactionary dentin formation (indirect contact). An original aspect of this study is the use of an interposed thin agarose gel layer to assess the effects of diffusible components from the materials. Results The two biomaterials were compared and did not modify dental pulp stem cell (DPSC) proliferation. BD and BR showed no significant cytotoxicity, although some cell death occurred in direct contact. No apoptosis or inflammation induction was detected. A striking increase of mineralization induction was observed in the presence of BD and BR, and this effect was greater in direct contact. Surprisingly, biomineralization occurred even in the absence of mineralization medium. This differentiation was accompanied by expression of odontoblast-associated genes. Exposure by indirect contact did not stimulate the induction to such a level. Conclusion These two biomaterials both seem to be bioactive and biocompatible, preserving DPSC proliferation, migration and adhesion. The observed strong mineralization induction through direct contact highlights the potential of these biomaterials for clinical application in dentin-pulp complex regeneration. PMID:29370163

In-situ hybridization of calcium silicate and hydroxyapatite-gelatin nanocomposites enhances physical property and in vitro osteogenesis.

PubMed

Chiu, Chi-Kai; Lee, Dong Joon; Chen, Hsin; Chow, Laurence C; Ko, Ching-Chang

2015-02-01

Low mechanical strengths and inadequate bioactive material-tissue interactions of current synthetic materials limit their clinical applications in bone regeneration. Here, we demonstrate gelatin modified siloxane-calcium silicate (GEMOSIL-CS), a nanocomposite made of gelatinous hydroxyapatite with in situ pozzolanic formation of calcium silicate (CS) interacting among gelatin, silica and Calcium Hydroxide (Ca(OH)2). It is shown the formation of CS matrices, which chemically bonds to the gelatinous hydroxyapatite, provided hygroscopic reinforcement mechanism and promoted both in vitro and in vivo osteogenic properties of GEMOSIL-CS. The formation of CS was identified by Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction. The interfacial bindings within nanocomposites were studied by FTIR and thermogravimetric analysis. Both gelatin and CS have been found critical to the structure integrity and mechanical strengths (93 MPa in compressive strength and 58.9 MPa in biaxial strength). The GEMOSIL-CS was biocompatible and osteoconductive as result of type I collagen secretion and mineralized nodule formation from MC3T3 osteoblasts. SEM and TEM indicated the secretion of collagen fibers and mineral particles as the evidence of mineralization in the early stage of osteogenic differentiation. In vivo bone formation capability was performed by implanting GEMOSIL-CS into rat calvarial defects for 12 weeks and the result showed comparable new bone formation between GEMOSIL-CS group (20%) and the control (20.19%). The major advantage of GEMOSIL-CS composites is in situ self-hardening in ambient or aqueous environment at room temperature providing a simple, fast and cheap method to produce porous scaffolds.

Characterization of un-hydrated and hydrated BioAggregate™ and MTA Angelus™.

PubMed

Camilleri, J; Sorrentino, F; Damidot, D

2015-04-01

BioAggregate™ is a novel material introduced for use as a root-end filling material. It is tricalcium silicate-based, free of aluminium and uses tantalum oxide as radiopacifier. BioAggregate contains additives to enhance the material performance. The purpose of this research was to characterize the un-hydrated and hydrated forms of BioAggregate using a combination of techniques, verify whether the additives if present affect the properties of the set material and compare these properties to those of MTA Angelus™. Un-hydrated and hydrated BioAggregate and MTA Angelus were assessed. Un-hydrated cement was tested for chemical composition, specific surface area, mineralogy and kinetics of hydration. The set material was investigated for mineralogy, microstructure and bioactivity. Scanning electron microscopy, X-ray energy dispersive spectroscopic analysis, X-ray fluorescence spectroscopy, X-ray diffraction and isothermal calorimetry were employed. The specific surface area was investigated using a gas adsorption method with nitrogen as the probe. BioAggregate was composed of tricalcium silicate, tantalum oxide, calcium phosphate and silicon dioxide and was free of aluminium. On hydration, the tricalcium silicate produced calcium silicate hydrate and calcium hydroxide. The former was deposited around the cement grains, while the latter reacted with the silicon dioxide to form additional calcium silicate hydrate. This resulted in reduction of calcium hydroxide in the aged cement. MTA Angelus reacted in a similar fashion; however, since it contained no additives, the calcium hydroxide was still present in the aged cement. Bioactivity was demonstrated by deposition of hydroxyapatite. BioAggregate exhibited a high specific surface area. Nevertheless, the reactivity determined by isothermal calorimetry appeared to be slow compared to MTA Angelus. The tantalum oxide as opposed to bismuth oxide was inert, and tantalum was not leached in solution. BioAggregate exhibited high calcium ion release early, which was maintained over the 28-day period as opposed to MTA Angelus, which demonstrated low early calcium ion release which increased as the material aged. The mineralogical composition of BioAggregate was different to MTA Angelus. As opposed to MTA Angelus, BioAggregate did not contain aluminium and contained additives such as calcium phosphate and silicon dioxide. As a consequence, BioAggregate reacted more slowly and formation of calcium hydroxide and leaching of calcium ions in solution were not evident as the material aged. The additives in BioAggregate modify the kinetics and the end products of hydration. Although newer generation tricalcium silicate-based materials contain similar constituents to MTA, they do not undergo the same setting reactions, and thus, their clinical performance will not be comparable to that of MTA.

Steam based conversion coating on AA6060 alloy: Effect of sodium silicate chemistry and corrosion performance

NASA Astrophysics Data System (ADS)

Din, Rameez Ud; Bordo, Kirill; Tabrizian, Naja; Jellesen, Morten Stendahl; Ambat, Rajan

2017-11-01

Surface treatment of aluminium alloy AA6060 using an industrially applicable pilot steam jet system with and without silicate chemistry has been investigated. Treatment using steam alone and steam with silicate, resulted in an oxide layer formation with thickness ∼425 nm and ∼160 nm, respectively. Moreover, the use of sodium silicate resulted in the formation of distinct microstructure and incorporation of silicate into the oxide film. These oxide films reduced the anodic activity 4 times, while the corrosion protection by silicate containing oxide was the function of its concentration. Further, in acid salt spray and filiform corrosion tests, oxide layer containing silicate exhibited two times higher corrosion resistance.

Cytotoxicity of modified glass ionomer cement on odontoblast cells.

PubMed

Chen, Song; Mestres, Gemma; Lan, Weihua; Xia, Wei; Engqvist, Håkan

2016-07-01

Recently a modified glass ionomer cement (GIC) with enhanced bioactivity due to the incorporation of wollastonite or mineral trioxide aggregate (MTA) has been reported. The aim of this study was to evaluate the cytotoxic effect of the modified GIC on odontoblast-like cells. The cytotoxicity of a conventional GIC, wollastonite modified GIC (W-mGIC), MTA modified GIC (M-mGIC) and MTA cement has been evaluated using cement extracts, a culture media modified by the cement. Ion concentration and pH of each material in the culture media were measured and correlated to the results of the cytotoxicity study. Among the four groups, conventional GIC showed the most cytotoxicity effect, followed by W-mGIC and M-mGIC. MTA showed the least toxic effect. GIC showed the lowest pH (6.36) while MTA showed the highest (8.62). In terms of ion concentration, MTA showed the largest Ca(2+) concentration (467.3 mg/L) while GIC showed the highest concentration of Si(4+) (19.9 mg/L), Al(3+) (7.2 mg/L) and Sr(2+) (100.3 mg/L). Concentration of F(-) was under the detection limit (0.02 mg/L) for all samples. However the concentrations of these ions are considered too low to be toxic. Our study showed that the cytotoxicity of conventional GIC can be moderated by incorporating calcium silicate based ceramics. The modified GIC might be promising as novel dental restorative cements.

The nature, fabrication, and applications of photosensitive, bulk, germano-silicate glass

NASA Astrophysics Data System (ADS)

Heaney, Alan Douglas

2000-08-01

The photosensitive nature of germano-silicate glass is widely used to create fiber-optic devices. This thesis examines the cause of photosensitivity in germano- silicate glass. The results of this research elucidate the role that germanium oxygen deficient defects play in the photosensitivity of hydrogen-loaded, germano-silicate glass. We find that defects are not vital to the photosensitivity of hydrogen-loaded, germano-silicate glass but they do enhance the effect. Quantitative measurements show that germanium oxygen deficient defects promote the formation of OH, GeH, and GeH2 when hydrogen-loaded, germano-silicate glass is exposed to ultraviolet light. A sol-gel process for fabricating germano-silicate glass in bulk samples has been developed. The sol-gel process produces high-quality, germano-silicate glass which can be tailored to contain defects or be relatively free of defects. Control over the glass defect concentration allows us to use sol-gel derived glass for comparative studies of the photosensitive process and for device applications. The unique properties of germano-silicate glass make it a likely choice for use in optical applications. To prove the feasibility of bulk devices, chirped-pulse amplification is demonstrated using gratings written in bulk germano-silicate glass.

12om Methodology: Process v1.1

DTIC Science & Technology

2014-03-31

in support of the Applied Research Project (ARP) 12om entitled “Collaborative Understanding of Complex Situations”. The overall purpose of this...Definition ARP Applied Research Project CF Canadian Forces CFOPP Canadian Forces Operational Planning Process CIDA Canadian International... Research Project (ARP) 12om entitled “Collaborative Understanding of Complex Situations”. The overall purpose of this project is to develop a

The Relation between Speech Perception and Phonemic Awareness: Evidence from Low-SES Children and Children with Chronic OM.

ERIC Educational Resources Information Center

Nittrouer, Susan

1996-01-01

This study of 41 children (ages 7 and 8) studied the effects of low socioeconomic status (SES) and chronic otitis media (OM) on speech perception and phonemic awareness. Findings indicated the children with low SES did poorly on both kinds of tasks whether or not they had chronic OM. (CR)

77 FR 41399 - EC&R O&M, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-13

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER12-2145-000] EC&R O&M, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization This is a supplemental notice in the above-referenced proceeding of EC&R O&M, LLC's application...

Barrier Properties of Layered-Silicate Reinforced Ethylenepropylenediene Monomer/Chloroprene Rubber Nanorubbers

PubMed Central

Hsieh, Wen Yen; Cheng, Kuo Bin; Lai, Chiu-Chun; Lee, Kuei Chi

2018-01-01

The triacetin and nitroglycerin barrier properties of layered-silicate reinforced ethylenepropylenediene monomer/chloroprene rubber (EPDM/CR) nanorubbers were investigated as rocket-propellant inhibitors. EPDM/CR nanorubbers with intercalated structures were formulated and prepared by the melt-compounding method. The triacetin permeability and nitroglycerin absorption were observed to decrease with increasing layered-silicate content. The layered silicates also improved the flame retardancies of the nanorubbers by forming silicate reinforced carbonaceous chars. Layered-silicate reinforced EPDM/CR nanorubbers are potentially effective rocket propellant-inhibiting materials. PMID:29747427

Diesel-Powered Equipment Properties and Activity Database for DoD Off-Road Sources

DTIC Science & Technology

2006-03-01

CUMMINS ENGINE V903C 408 429,250 0.5% 96.4% MERCEDES BENZ OM 352 1,901 409,317 0.5% 96.9% CATERPILLAR 3306 278 400,886 0.5% 97.4% CATERPILLAR 3208 126... MERCEDES BENZ OM 603-950 501 35,841 0.0% 99.9% CATERPILLAR 3406 907 28,081 0.0% 100.0% MERCEDES BENZ OM402AT 70 23,293 0.0% 100.0% DEUTZ F4L-912 50 8,279...Consumption % of Total Total MERCEDES BENZ OM 352 1,901 409,317 0.5% 96.9% Equipment using this Engine Fuel Usage Nomenclature Service

A Novel Phase Sensitive Quantum Well Nanostructure Scheme for Controlling Optical Bistability

NASA Astrophysics Data System (ADS)

Raheli, Ali

2018-04-01

A novel four-level lambda-type quantum well (QW) nanostructure is proposed based on phase sensitive optical bistability (OB) and multistability (OM) with a closed-loop configuration. The influence of controlling parameters of the system on OB and OM is investigated. In particular, it is found that the OB behavior is strongly sensitive to the relative phase of applied fields. It is also shown that under certain parametric conditions, the OB can be switched to OM or vice versa. The controllability of OB/OM in such a QW nanostructure may bring some new possibilities for technological applications in solid-state quantum information science and optoelectronics.

The sebaceous gland antigen defined by the OM-1 monoclonal antibody is expressed at high density on the surface of ovarian carcinoma cells.

PubMed

de Kretser, T A; Thorne, H J; Jacobs, D J; Jose, D G

1985-09-01

A monoclonal antibody, designated OM-1, was raised against ovarian serous papillary cystadenocarcinoma (stage IV) cells. This antibody was found to react strongly with primary and metastatic ovarian serous cystadenocarcinomas and endometrioid carcinomas but the antigen detected was either absent or at very low levels in ovarian mucinous adenocarcinomas, clear cell carcinomas, benign serous and mucinous cystadenomas and Brenner tumours. The OM-1 antibody gave no detectable reaction with 93 other human tumours, including examples of breast and colon adenocarcinomas. In normal tissues the OM-1 antibody reacted with normal sebaceous gland cells, lung type II pneumocytes and placental syncytial trophoblasts. In the normal ovary OM-1 reactivity was confined to extremely weak staining of the surface epithelium. No reaction with any other ovarian cell type could be detected. No evidence of reaction with other normal cell populations present in 24 adult and seven foetal tissues was found. The antigen detected is compared with other ovarian tumour-associated antigens. The OM-1 antibody is likely to prove of value in the detection and diagnosis of ovarian carcinoma.

The prevention of oral mucositis in patients with blood cancers: current concepts and emerging landscapes.

PubMed

Niscola, Pasquale; Tendas, Andrea; Cupelli, Luca; Catalano, Gianfranco; Scaramucci, Laura; Giovannini, Marco; Trinchieri, Vito; Sharma, Atul; Efficace, Fabio; Cartoni, Claudio; Piccioni, Daniela; Perrotti, Alessio; Dentamaro, Teresa; de Fabritiis, Paolo; Keefe, Dorothy M K

2012-12-01

The prevention of oral mucositis (OM) in the management of hematological malignancies continues to represent an unmet clinical need. Addressing this issue has major clinical implications as OM can also greatly impair patient's quality of life. To review currently available measures and investigational agents to prevent OM in hematological patients. we searched for OM and related issues using Medline; the abstract books of the most important hematological and oncological meetings were also reviewed. Many agents targeting different mechanisms of mucosal damage have been applied in order to prevent OM; most of them have failed or its efficacy has not been fully demonstrated. Palifermin is the first pharmaceutical/biological agent approved for the prevention of OM; its use is currently restricted to patients who have received radiotherapy-containing conditioning regimens prior to autologous hematopoietic stem cell transplantation. No clear benefit by this agent has been demonstrated outside of this specific setting and its application should be limited to clinical trials. Other interventions, such as other growth factors and non mitogenic measures are under investigation or in development and their application in the hematological setting is expected in the short term.

Enhancement of arsenite removal using manganese oxide coupled with iron (III) trimesic

NASA Astrophysics Data System (ADS)

Phanthasri, Jakkapop; Khamdahsag, Pummarin; Jutaporn, Panitan; Sorachoti, Kwannapat; Wantala, Kitirote; Tanboonchuy, Visanu

2018-01-01

A simultaneous removal of As(III) was investigated on a mixture of manganese oxide based octahedral molecular sieves (K-OMS2) and iron-benzenetricarboxylate (Fe-BTC). As(III) removal was stimulated by an oxidation cooperated with adsorption process. K-OMS2 and Fe-BTC were separately synthesized and characterized by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). K-OMS2 showed characters of pure cryptomelane phase, nanorod structure, and a mixed-valent manganese framework with the coexistence of Mn(IV) and Mn(III). As(III) was successfully oxidized to As(V) by K-OMS2 in a temperature range of 303-333 K. An intermediate adsorption of As(V) was carried out with Fe-BTC in the same batch. A maximum adsorption capacity, described by Langmuir isotherm model, was observed at 76.34 mg/g. With an As(III) initial concentration of 5 mg/L, when K-OMS2 and Fe-BTC were simultaneously introduced into the solution, the As(III) removal process was completed within 60 min. Thus, it shortened the process time compared to the case where K-OMS2 was added first, followed by the addition of Fe-BTC.

Optomechanical coupling in phoxonic–plasmonic slab cavities with periodic metal strips

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

Lin, Tzy-Rong; Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung 20224, Taiwan; Huang, Yin-Chen

2015-05-07

We theoretically investigate the optomechanical (OM) coupling of submicron cavities formed in one-dimensional phoxonic–plasmonic slabs. The phoxonic–plasmonic slabs are structured by depositing periodic Ag strips onto the top surfaces of dielectric GaAs slabs to produce dual band gaps for both electromagnetic and acoustic waves, thereby inducing the coupling of surface plasmons with photons for tailoring the OM coupling. We quantify the OM coupling by calculating the temporal modulation of the optical resonance wavelength with the acoustic phonon-induced photoelastic (PE) and moving-boundary (MB) effects. We also consider the appearance of a uniform Ag layer on the bottom surface of the slabsmore » to modulate the photonic–plasmonic coupling. The results show that the PE and MB effects can be constructive or destructive in the overall OM coupling, and their magnitudes depend not only on the quality factors of the resonant modes but also on the mode area, mode overlap, and individual symmetries of the photonic–phononic mode pairs. Lowering the mode area could be effective for enhancing the OM coupling of subwavelength photons and phonons. This study introduces possible engineering applications to achieve enhanced interaction between photons and phonons in nanoscale OM devices.« less

Sulfurized carbohydrates: an important sedimentary sink for organic carbon?

NASA Astrophysics Data System (ADS)

Sinninghe Damsté, Jaap S.; Kok, Marika D.; Köster, Jürgen; Schouten, Stefan

1998-12-01

In contrast to the general belief that carbohydrate carbon (C CHO) is preferentially degraded and is not extensively preserved in the sedimentary record, it is shown here that C CHO forms a large fraction of the organic matter (OM) of the total organic carbon (TOC)-rich upper Jurassic Kimmeridge Clay Formation as a result of early diagenetic sulfurization, a previously unrecognized pathway of OM preservation. This is evident from both changes in the molecular composition of the insoluble OM and from δ 13C TOC shifts of 6‰ with varying C CHO contents. Furthermore, experiments simulating the natural sulfurization of the C CHO-rich alga Phaeocystis spp. demonstrated that sulfurization can indeed lead to a substantial preservation of C CHO with a molecular fingerprint identical to that of the Kimmeridge Clay and many other Recent and ancient marine OM-rich sediments. These results imply that preservation of C CHO can exert a fundamental control on δ 13C TOC in OM-rich sediments, complicating the interpretation of δ 13C TOC records with regard to estimating terrestrial versus aquatic OM fractions, reconstruction of past atmospheric CO 2 levels and global carbon budget models.

Eustachian tube function in adults without middle ear disease.

PubMed

Swarts, J Douglas; Alper, Cuneyt M; Mandel, Ellen M; Villardo, Richard; Doyle, William J

2011-04-01

We sought to develop normative values for 5 eustachian tube function (ETF) test protocols in adults without otitis media (OM). Twenty adults (19 to 48 years of age) without a recent history of OM (5 had OM in childhood) underwent unilateral myringotomy and were evaluated for ETF by use of the forced response, inflation, deflation, forcible "sniff", and Valsalva test protocols. When possible, these tests were repeated on a second day. Normative values for the parameters of these protocols in adult subjects without a recent history of OM were developed. Between-day data for the forced response test were highly correlated. A percentage of these tests showed eustachian tube "constriction" during swallowing--an abnormal condition. The percent reduction in applied pressures for the inflation and deflation tests was high, indicative of good ETF. Few subjects had a positive "sniff" test, whereas most had a positive Valsalva test, and the results for both tests were effort-dependent. Results of ETF tests in adults with and without recent OM have not been published. Normative data are now available for comparison with ETF test results in adults with OM. These protocols will be used to evaluate the efficacy of surgical procedures designed to improve ETF.

Analysis of the olfactory mucosa in chronic rhinosinusitis

PubMed Central

Yee, Karen K.; Pribitkin, Edmund A.; Cowart, Beverly J.; Rosen, David; Feng, Pu; Rawson, Nancy E

2009-01-01

The impact of chronic rhinosinusitis (CRS) on the olfactory mucosa (OM) is dramatic. Cellular profiles and epithelial integrity in OM biopsies were evaluated using histological and immunohistochemical methods to define a strategy for future histological studies of CRS. We have examined nasal biopsies of 54 CRS patients (18 - 63 years old) and have defined specific histopathological patterns of the OM: normal pseudostratified, goblet cell hyperplasia, squamous metaplasia and erosion. Goblet cell hyperplasia was most similar to a normal pseudostratified OM pattern but with goblet cells intermixed in the apical layers. Squamous metaplasia exhibited an absence of olfactory supporting cells and had olfactory sensory neurons that were morphologically abnormal. It is unknown if these neurons would be functional in this type of tissue transformation. The pattern of erosion exhibited a severe loss of epithelial layers and a higher prevalence of infiltrating inflammatory cells within the olfactory epithelium when compared to the other OM patterns. Although it is not known if the OM remodeling patterns we have noted correspond to specific stages or distinct pathways of the disease, the template proposed here can be used in further studies to understand how the histopathological progression of CRS relates to olfactory loss and the response to treatment. PMID:19686198

Role of Gabapentin in Managing Mucositis Pain in Patients Undergoing Radiation Therapy to the Head and Neck.

PubMed

Milazzo-Kiedaisch, Carol Ann; Itano, Joanne; Dutta, Pinaki R

2016-12-01

Oral mucositis (OM) is a painful and debilitating side effect that affects 80%-100% of patients undergoing radiation therapy for head and neck cancer. This dose-limiting side effect may potentially lead to pain, dehydration, malnutrition, infection, and treatment breaks. Treatment breaks can lead to decreased disease control and suboptimal patient outcomes. No primary prevention exists for OM, and management is focused on pain control. Compelling evidence exists that OM pain has somatic and neuropathic components. This article reviews the existing literature on the use of gabapentin (Neurontin®) as a co-analgesic in treating the neuropathic pain in OM. A literature search was performed using CINAHL® and PubMed with the search terms gabapentin and oral mucositis. The selected articles were briefly screened for relevance, and three were included in this review. No systematic reviews exist on the role of gabapentin for neuropathic pain in radiation-induced OM. Two retrospective studies concluded that gabapentin reduced escalation of opioid doses and unplanned treatment breaks. One retrospective study demonstrated favorable swallowing outcomes. Pain and OM are nursing-sensitive outcomes that can be significantly affected by evidence-based nursing interventions.

Clinical and genetic determinants of ovarian metastases from colorectal cancer.

PubMed

Ganesh, Karuna; Shah, Ronak H; Vakiani, Efsevia; Nash, Garrett M; Skottowe, Hugh P; Yaeger, Rona; Cercek, Andrea; Lincoln, Anne; Tran, Christina; Segal, Neil H; Reidy, Diane L; Varghese, Anna; Epstein, Andrew S; Sonoda, Yukio; Chi, Dennis; Guillem, Jose; Temple, Larissa; Paty, Philip; Hechtman, Jaclyn; Shia, Jinru; Weiser, Martin; Aguilar, Julio Garcia; Kemeny, Nancy; Berger, Michael F; Saltz, Leonard; Stadler, Zsofia K

2017-04-01

Ovarian metastases from colorectal cancer (OM-CRC) often are unresponsive to chemotherapy and are associated with poor survival. To the authors' knowledge, the clinicopathologic and genomic predictors of OM-CRC are poorly characterized and optimal clinical management remains unclear. Women with a histopathological diagnosis of OM-CRC who were treated at Memorial Sloan Kettering Cancer Center from 1999 to 2015 were identified. Next-generation somatic mutation profiling (Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets [MSK-IMPACT]) was performed on 38 OM-CRC cases, including 21 matched tumor pairs/trios. Regression models were used to analyze variables associated with progression-free survival and overall survival (OS). Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS), SMAD family member 4 (SMAD4), and neurotrophic receptor tyrosine kinase 1 (NTRK1) mutations were more frequent in cases of OM-CRC than in instances of CRC occurring without OM. SMAD4 and lysine methyltransferase 2D (KMT2D) mutations were associated with reduced OS. Matched multisite tumor sequencing did not identify OM-specific genomic alterations. Of the 195 patients who underwent oophorectomy for OM-CRC (median age, 49 years with a progression-free survival of 9.4 months and an OS of 23 months from oophorectomy), 76% had extraovarian metastasis (EOM). In multivariable analysis, residual disease after surgery (R2 resection) was associated with worse survival. Patients with EOM were less likely to achieve R0/R1 surgical resection status (complete macroscopic resection without clinical/radiological evidence of disease) (48% vs 94%). However, if R0/R1 resection status was achieved, both patients with (35.9 months vs 12 months) and without (43.2 months vs 14.5 months) EOM were found to have better OS. Among 114 patients with R0/R1 resection status, 23 (20%) had no disease recurrence, including 10 patients (9%) with > 3 years of follow-up. Loss-of-function alterations in SMAD4 are frequent and predictive of worse survival in patients with OM-CRC. Similar to oligometastatic CRC to the lung or liver, surgical resection of OM-CRC is associated with a better outcome only if all macroscopic metastatic disease is resected. Cancer 2017;123:1134-1143. © 2016 American Cancer Society. © 2016 American Cancer Society.

Structural basis for maintenance of bacterial outer membrane lipid asymmetry.

PubMed

Abellón-Ruiz, Javier; Kaptan, Shreyas S; Baslé, Arnaud; Claudi, Beatrice; Bumann, Dirk; Kleinekathöfer, Ulrich; van den Berg, Bert

2017-12-01

The Gram-negative bacterial outer membrane (OM) is a unique bilayer that forms an efficient permeation barrier to protect the cell from noxious compounds 1 , 2 . The defining characteristic of the OM is lipid asymmetry, with phospholipids comprising the inner leaflet and lipopolysaccharides comprising the outer leaflet 1-3 . This asymmetry is maintained by the Mla pathway, a six-component system that is widespread in Gram-negative bacteria and is thought to mediate retrograde transport of misplaced phospholipids from the outer leaflet of the OM to the cytoplasmic membrane 4 . The OM lipoprotein MlaA performs the first step in this process via an unknown mechanism that does not require external energy input. Here we show, using X-ray crystallography, molecular dynamics simulations and in vitro and in vivo functional assays, that MlaA is a monomeric α-helical OM protein that functions as a phospholipid translocation channel, forming a ~20-Å-thick doughnut embedded in the inner leaflet of the OM with a central, amphipathic pore. This architecture prevents access of inner leaflet phospholipids to the pore, but allows outer leaflet phospholipids to bind to a pronounced ridge surrounding the channel, followed by diffusion towards the periplasmic space. Enterobacterial MlaA proteins form stable complexes with OmpF/C 5,6 , but the porins do not appear to play an active role in phospholipid transport. MlaA represents a lipid transport protein that selectively removes outer leaflet phospholipids to help maintain the essential barrier function of the bacterial OM.

Supplementation with concentrated milk protein in patients undergoing hematopoietic stem cell transplantation.

PubMed

Perrone, Ana Carolina Amaral de São José; Barbosa, Thaís Rodrigues; da Silva, Fernanda Lopes; Perrone, Ítalo Tuler; de Carvalho, Antônio Fernandes; Stephani, Rodrigo; Dos Santos, Kelli Borges; Atalla, Ângelo; Hallack Neto, Abrahão Elias

2017-05-01

The aim of this study was to analyze the influence of dietary supplementation with whey protein concentrate (WPC) in the incidence of oral mucositis (OM) in patients undergoing hematopoietic stem cell transplantation (HSCT). Patients were supplemented with a daily intake of WPC delivering 50% of the daily protein requirements (DPR) according to the Dietary Reference Intakes and classified later based on the amount of ingested supplement until OM median onset. We evaluated 73 patients. Forty-three were part of the historical control and 30 were supplemented with WPC. The OM had a mean duration of 5.3 d (SD 4.5), ranging from the day of the infusion of stem cells until the 17th day after infusion and a median of 5 d after infusion. OM duration was influenced by the conditioning protocol (P < 0.01) and WPC (P = 0.01). Patients who consumed the WPC in an amount ≥40% of DPR had a 35% reduction in duration of OM, and the incidence of OM grades 3 and 4 was 11 times smaller. Body mass index, serum albumin, and adverse reactions, such as diarrhea, nausea and vomiting, dysphagia, dry mouth and drooling, showed no statistically significant differences. WPC intake ≥40% of DPR helped to reduce the severity and duration of OM. The use of WPC in patients undergoing HSCT was shown to be safe, encouraging new studies in this population to assess its action mechanism. Copyright © 2016 Elsevier Inc. All rights reserved.

A Transposon Screen Identifies Genetic Determinants of Vibrio cholerae Resistance to High-Molecular-Weight Antibiotics

PubMed Central

Delgado, Fernanda; Umans, Benjamin D.; Gerding, Matthew A.; Davis, Brigid M.

2016-01-01

Gram-negative bacteria are notoriously resistant to a variety of high-molecular-weight antibiotics due to the limited permeability of their outer membrane (OM). The basis of OM barrier function and the genetic factors required for its maintenance remain incompletely understood. Here, we employed transposon insertion sequencing to identify genes required for Vibrio cholerae resistance to vancomycin and bacitracin, antibiotics that are thought to be too large to efficiently penetrate the OM. The screen yielded several genes whose protein products are predicted to participate in processes important for OM barrier functions and for biofilm formation. In addition, we identified a novel factor, designated vigA (for vancomycin inhibits growth), that has not previously been characterized or linked to outer membrane function. The vigA open reading frame (ORF) codes for an inner membrane protein, and in its absence, cells became highly sensitive to glycopeptide antibiotics (vancomycin and ramoplanin) and bacitracin but not to other large antibiotics or detergents. In contrast to wild-type (WT) cells, the vigA mutant was stained with fluorescent vancomycin. These observations suggest that VigA specifically prevents the periplasmic accumulation of certain large antibiotics without exerting a general role in the maintenance of OM integrity. We also observed marked interspecies variability in the susceptibilities of Gram-negative pathogens to glycopeptides and bacitracin. Collectively, our findings suggest that the OM barrier is not absolute but rather depends on specific OM-antibiotic interactions. PMID:27216069

Induction of interleukin 6 and interleukin 8 expression by Broncho-Vaxom (OM-85 BV) via C-Fos/serum responsive element.

PubMed Central

Keul, R.; Roth, M.; Papakonstantinou, E.; Nauck, M.; Perruchoud, A. P.; Block, L. H.

1996-01-01

BACKGROUND: Broncho-Vaxom (OM-85 BV) increases the resistance of the respiratory tract to bacterial infections by modulating host immune responses. The compound increases serum IgG levels but decreases IgE levels in patients suffering from chronic bronchitis or chronic obstructive pulmonary disease. It increases concentrations of gamma-interferon (IFN-gamma), IgA, and interleukin (IL)-2 in bronchoalveolar lavage fluid of patients with bronchitis. Treatment with OM-85 BV increases the number of T helper and natural killer cells. In this study the effects of OM-85 BV on transcription of cytokines is investigated in human lung fibroblasts. METHODS: Transcription and synthesis of IL-6 and IL-8 were assessed in cultured primary human lung fibroblasts using standard methods of Northern blot analysis for the level of mRNAs and enzyme linked immunosorbent assay for proteins. RESULTS: Broncho-Vaxom (OM-85 BV) at different concentrations induced transcription of IL-6 and IL-8. The effect of the drug on transcription of IL-6 and IL-8 genes correlated with secretion of the proteins into cell supernatants. OM-85 BV-dependent expression of the interleukin genes involved C-Fos/serum responsive element (C-Fos/SRE). CONCLUSIONS: The data suggest that the various immunopharmacological activities of OM-85 BV that have been described in clinical studies may be explained by its ability to induce expression of IL-6 and IL-8. Images PMID:8711646

Mesoporous TiO2 Bragg Stack Templated by Graft Copolymer for Dye-sensitized Solar Cells

PubMed Central

Park, Jung Tae; Chi, Won Seok; Kim, Sang Jin; Lee, Daeyeon; Kim, Jong Hak

2014-01-01

Organized mesoporous TiO2 Bragg stacks (om-TiO2 BS) consisting of alternating high and low refractive index organized mesoporous TiO2 (om-TiO2) films were prepared to enhance dye loading, light harvesting, electron transport, and electrolyte pore-infiltration in dye-sensitized solar cells (DSSCs). The om-TiO2 films were synthesized via a sol-gel reaction using amphiphilic graft copolymers consisting of poly(vinyl chloride) backbones and poly(oxyethylene methacrylate) side chains, i.e., PVC-g-POEM as templates. To generate high and low index films, the refractive index of om-TiO2 film was tuned by controlling the grafting ratio of PVC-g-POEM via atomic transfer radical polymerization (ATRP). A polymerized ionic liquid (PIL)-based DSSC fabricated with a 1.2-μm-thick om-TiO2 BS-based photoanode exhibited an efficiency of 4.3%, which is much higher than that of conventional DSSCs with a nanocrystalline TiO2 layer (nc-TiO2 layer) (1.7%). A PIL-based DSSC with a heterostructured photoanode consisting of 400-nm-thick organized mesoporous TiO2 interfacial (om-TiO2 IF) layer, 7-μm-thick nc-TiO2, and 1.2-μm-thick om-TiO2 BS as the bottom, middle and top layers, respectively, exhibited an excellent efficiency of 7.5%, which is much higher than that of nanocrystaline TiO2 photoanode (3.5%). PMID:24980936

Characterization of lptA and lptB, two essential genes implicated in lipopolysaccharide transport to the outer membrane of Escherichia coli.

PubMed

Sperandeo, Paola; Cescutti, Rachele; Villa, Riccardo; Di Benedetto, Cristiano; Candia, Daniela; Dehò, Gianni; Polissi, Alessandra

2007-01-01

The outer membrane (OM) of gram-negative bacteria is an asymmetric lipid bilayer that protects the cell from toxic molecules. Lipopolysaccharide (LPS) is an essential component of the OM in most gram-negative bacteria, and its structure and biosynthesis are well known. Nevertheless, the mechanisms of transport and assembly of this molecule in the OM are poorly understood. To date, the only proteins implicated in LPS transport are MsbA, responsible for LPS flipping across the inner membrane, and the Imp/RlpB complex, involved in LPS targeting to the OM. Here, we present evidence that two Escherichia coli essential genes, yhbN and yhbG, now renamed lptA and lptB, respectively, participate in LPS biogenesis. We show that mutants depleted of LptA and/or LptB not only produce an anomalous LPS form, but also are defective in LPS transport to the OM and accumulate de novo-synthesized LPS in a novel membrane fraction of intermediate density between the inner membrane (IM) and the OM. In addition, we show that LptA is located in the periplasm and that expression of the lptA-lptB operon is controlled by the extracytoplasmic sigma factor RpoE. Based on these data, we propose that LptA and LptB are implicated in the transport of LPS from the IM to the OM of E. coli.

Characterization of lptA and lptB, Two Essential Genes Implicated in Lipopolysaccharide Transport to the Outer Membrane of Escherichia coli▿

PubMed Central

Sperandeo, Paola; Cescutti, Rachele; Villa, Riccardo; Di Benedetto, Cristiano; Candia, Daniela; Dehò, Gianni; Polissi, Alessandra

2007-01-01

The outer membrane (OM) of gram-negative bacteria is an asymmetric lipid bilayer that protects the cell from toxic molecules. Lipopolysaccharide (LPS) is an essential component of the OM in most gram-negative bacteria, and its structure and biosynthesis are well known. Nevertheless, the mechanisms of transport and assembly of this molecule in the OM are poorly understood. To date, the only proteins implicated in LPS transport are MsbA, responsible for LPS flipping across the inner membrane, and the Imp/RlpB complex, involved in LPS targeting to the OM. Here, we present evidence that two Escherichia coli essential genes, yhbN and yhbG, now renamed lptA and lptB, respectively, participate in LPS biogenesis. We show that mutants depleted of LptA and/or LptB not only produce an anomalous LPS form, but also are defective in LPS transport to the OM and accumulate de novo-synthesized LPS in a novel membrane fraction of intermediate density between the inner membrane (IM) and the OM. In addition, we show that LptA is located in the periplasm and that expression of the lptA-lptB operon is controlled by the extracytoplasmic σ factor RpoE. Based on these data, we propose that LptA and LptB are implicated in the transport of LPS from the IM to the OM of E. coli. PMID:17056748

Effects of effluent organic matter characteristics on the removal of bulk organic matter and selected pharmaceutically active compounds during managed aquifer recharge: Column study

NASA Astrophysics Data System (ADS)

Maeng, Sung Kyu; Sharma, Saroj K.; Abel, Chol D. T.; Magic-Knezev, Aleksandra; Song, Kyung-Guen; Amy, Gary L.

2012-10-01

Soil column experiments were conducted to investigate the effects of effluent organic matter (EfOM) characteristics on the removal of bulk organic matter (OM) and pharmaceutically active compounds (PhACs) during managed aquifer recharge (MAR) treatment processes. The fate of bulk OM and PhACs during an MAR is important to assess post-treatment requirements. Biodegradable OM from EfOM, originating from biological wastewater treatment, was effectively removed during soil passage. Based on a fluorescence excitation-emission matrix (F-EEM) analysis of wastewater effluent-dominated (WWE-dom) surface water (SW), protein-like substances, i.e., biopolymers, were removed more favorably than fluorescent humic-like substances under oxic compared to anoxic conditions. However, there was no preferential removal of biopolymers or humic substances, determined as dissolved organic carbon (DOC) observed via liquid chromatography with online organic carbon detection (LC-OCD) analysis. Most of the selected PhACs exhibited removal efficiencies of greater than 90% in both SW and WWE-dom SW. However, the removal efficiencies of bezafibrate, diclofenac and gemfibrozil were relatively low in WWE-dom SW, which contained more biodegradable OM than did SW (copiotrophic metabolism). Based on this study, low biodegradable fractions such as humic substances in MR may have enhanced the degradation of diclofenac, gemfibrozil and bezafibrate by inducing an oligotrophic microbial community via long term starvation. Both carbamazepine and clofibric acid showed persistent behaviors and were not influenced by EfOM.

Lactoferrin-binding proteins in Shigella flexneri.

PubMed Central

Tigyi, Z; Kishore, A R; Maeland, J A; Forsgren, A; Naidu, A S

1992-01-01

The ability of Shigella flexneri to interact with lactoferrin (Lf) was examined with a 125I-labeled protein-binding assay. The percent binding of human lactoferrin (HLf) and bovine lactoferrin (BLf) to 45 S. flexneri strains was 19 +/- 3 and 21 +/- 3 (mean +/- standard error of the mean), respectively. 125I-labeled HLf and BLf binding to strain M90T reached an equilibrium within 2 h. Unlabeled HLf and BLf displaced the 125I-HLf-bacteria interaction in a dose-dependent manner. The Lf-bacterium complex was uncoupled by KSCN or urea, but not by NaCl. The interaction was specific, and approximately 4,800 HLf binding sites (affinity constant [Ka], 690 nM) or approximately 5,700 BLf binding sites (Ka, 104 nM) per cell were estimated in strain M90T by a Scatchard plot analysis. The native cell envelope (CE) and outer membrane (OM) did not reveal Lf-binding components in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. However, after being boiled, the CE and OM preparations showed three distinct horseradish peroxidase-Lf reactive bands of about 39, 22, and 16 kDa. The 39-kDa component was also reactive to a monoclonal antibody specific for porin (PoI) proteins of members of the family Enterobacteriaceae. The Lf-binding protein pattern was similar with BLf or HLf, for Crb+ and Crb- strains. The protein-Lf complex was dissociable by KSCN or urea and was stable after treatment with NaCl. Variation (loss) in the O chain of lipopolysaccharide (LPS) markedly enhanced the Lf-binding capacity in the isogenic rough strain SFL1070-15 compared with its smooth parent strain, SFL1070. These data establish that Lf binds to specific components in the bacterial OM; the heat-modifiable, anti-PoI-reactive, and LPS-associated properties suggested that the Lf-binding proteins are porins in S. flexneri. Images PMID:1319403

Solubility of copper in silicate melts as function of oxygen and sulfur fugacities, temperature, and silicate composition

NASA Astrophysics Data System (ADS)

Holzheid, A.; Lodders, K.

2001-06-01

The solubility of Cu in silicate melts coexisting with liquid Cu(Fe) metal and liquid Cu(Fe) sulfide was determined experimentally at oxygen fugacities ranging from 10 -9.1 to 10 -13.6 bar and sulfur fugacities ranging from 10 -2.5 to 10 -6.3 bar at 1300°C. An iron oxide-free silicate of anorthite-diopside eutectic composition and a synthetic MgO-rich basaltic silicate (FeO-bearing) were used in the partitioning experiments. In S-containing systems, some of the metal reacted to metal sulfide. The silicates in the four systems investigated (Fe-free and S-free; Fe-containing and S-free; Fe-free and S-containing; Fe-containing and S-containing) had different colors depending on the dissolved Cu species and the presence of iron and/or sulfur. Irrespective of the presence of sulfur, the solubility of Cu in the silicate increases with increasing oxygen fugacity and metal/silicate partition coefficients for Cu decrease. Increasing the temperature from 1300°C to 1514°C increases the Cu solubility (decreases the metal/silicate partition coefficient) at an oxygen fugacity 0.5 log units below the iron-wüstite (IW) equilibrium in the Fe-free, S-free and Fe-containing, S-free systems. We infer the presence of monovalent Cu + ("CuO 0.5") in the silicate melt on the basis of the solubility of Cu as function of oxygen fugacity. Experiments containing iron yield a formal valence of ˜0.5 for Cu at very low oxygen fugacities, which is not observed in Fe-free systems. The low formal valence is explained by redox reactions between iron and copper in the silicate melts. There is no evidence for sulfidic dissolution of Cu in the silicates but sulfur has indirect effects on Cu partitioning. Iron metal/silicate partition coefficients depend on oxygen fugacity and on sulfur fugacity. Sulfidic dissolution of iron and oxide-sulfide exchange reactions with Cu cause a small increase in Cu metal/silicate partition coefficients. We derive an activity coefficient (γ CuO 0.5) of 10 ± 1 for liquid CuO 0.5 at 1300°C for the silicate melts used here. A comparison with literature data shows that log γ CuO 0.5 increases in proportion to the mass percentages [CaO +(Al 2O 3)/2] in silicate melts. We recommend the following equations for Cu metal/silicate and sulfide/silicate partitioning for geochemical and cosmochemical modeling if silicate composition and the activity of Cu in the metal or sulfide is known: log D met/sil = -0.48 - 0.25 · log fO 2 - log γ Cu metal + 0.02 · [CaO + (Al 2O 3)/2; wt%] silicate logD sul/sil=+0.76-0.25 · logfO 2+0.25logfS 2-logγ CS 0.5,sulfide +0.02 · [CaO+Al 2O 3/2;wt%] silicate. The derived Cu metal/silicate and metal/sulfide partition coefficients are applied to core formation in the Earth and Mars. The observed Cu abundances in the Earth cannot be easily explained by simple core-mantle equilibrium, but the observed Cu abundances for Mars are consistent with core-mantle equilibrium at low pressure and temperatures.

An Investigation into the Properties and Microstructure of Cement Mixtures Modified with Cellulose Nanocrystal

PubMed Central

Flores, Jessica; Kamali, Mahsa; Ghahremaninezhad, Ali

2017-01-01

This paper aims to examine the effect of cellulose nanocrystals (CNC) on the hydration, transport behavior, and microstructure of cement mixtures. The addition of CNC delayed hydration at an early age but improved hydration at later ages. A small increase in the electrical resistivity of the cement mixtures with CNC was observed. Statistical nanoindentation showed a small tendency to a larger volume fraction of high density calcium-silicate-hydrate (C-S-H) and a smaller volume fraction of low-density C-S-H in the mixture with CNC. PMID:28772857

EFFECT OF SILICATE ON GRAM STAINING AND VIABILITY OF PNEUMOCOCCI AND OTHER BACTERIA

PubMed Central

MacLeod, Colin M.; Roe, Amy S.

1956-01-01

Application of silicate solutions to living or heat-killed pneumococci and to certain "viridans" streptococci causes their conversion from a Gram-positive to a Gram-negative state. The original staining properties can be restored by suspending the silicate-treated bacteria in alkaline solutions of various salts but not by simple washing in water. Living pneumococci and the strains of streptococci whose staining properties are similarly affected are killed when suspended in silicate solutions. In other Gram-positive species silicate causes conversion to Gram negativity but restoration to positivity occurs upon washing in water. In a third group of Gram-positive organisms silicate has no effect on the Gram reaction. The viability of organisms in these two groups is unaffected by silicate under the conditions employed. No effect on staining or viability of Gram-negative bacteria has been observed. The effects of silicate on staining and viability are inhibited by nutrient broth or whole serum but not by purified serum albumin. Lecithin, choline, and other substituted ammonium compounds also inhibit the effects of silicate on pneumococci. PMID:13306854

Synthesis and characterization of nanoporous silica aerogel beads using cheap industrial grade sodium silacte precursor

NASA Astrophysics Data System (ADS)

Khan, Tasneem M. A.; Khan, Asiya; Sarawade, Pradip B.

2018-05-01

We report a method to synthesize low-density transparent mesoporous silica aerogel beads by ambient pressure drying (APD). The beads were prepared by acid-base sol-gel polymerization of sodium silicate in via the ball dropping method (BDM). To minimize shrinkage during drying, wet silica beads were initially prepared; their surfaces were then modified using trimethylchlorosilane (TMCS) via simultaneous solvent exchange and surface modification. The specific surface area and cumulative pore volume of the silica aerogel beads increased with an increase in the %V of TMCS. Silica aerogel beads with low packing bed density, high surface area, and large cumulative pore volume was obtained when TMCS was used. Properties of the final product were examined by BET, and TG-DT analyses. The hydrophobic silica aerogel beads were thermally stable up to 350°C. We discuss our results and compare our findings for modified versus unmodified silica beads.

Pyrogenic organic matter production from wildfires: a missing sink in the global carbon cycle.

PubMed

Santín, Cristina; Doerr, Stefan H; Preston, Caroline M; González-Rodríguez, Gil

2015-04-01

Wildfires release substantial quantities of carbon (C) into the atmosphere but they also convert part of the burnt biomass into pyrogenic organic matter (PyOM). This is richer in C and, overall, more resistant to environmental degradation than the original biomass, and, therefore, PyOM production is an efficient mechanism for C sequestration. The magnitude of this C sink, however, remains poorly quantified, and current production estimates, which suggest that ~1-5% of the C affected by fire is converted to PyOM, are based on incomplete inventories. Here, we quantify, for the first time, the complete range of PyOM components found in-situ immediately after a typical boreal forest fire. We utilized an experimental high-intensity crown fire in a jack pine forest (Pinus banksiana) and carried out a detailed pre- and postfire inventory and quantification of all fuel components, and the PyOM (i.e., all visually charred, blackened materials) produced in each of them. Our results show that, overall, 27.6% of the C affected by fire was retained in PyOM (4.8 ± 0.8 t C ha(-1)), rather than emitted to the atmosphere (12.6 ± 4.5 t C ha(-1)). The conversion rates varied substantially between fuel components. For down wood and bark, over half of the C affected was converted to PyOM, whereas for forest floor it was only one quarter, and less than a tenth for needles. If the overall conversion rate found here were applicable to boreal wildfire in general, it would translate into a PyOM production of ~100 Tg C yr(-1) by wildfire in the global boreal regions, more than five times the amount estimated previously. Our findings suggest that PyOM production from boreal wildfires, and potentially also from other fire-prone ecosystems, may have been underestimated and that its quantitative importance as a C sink warrants its inclusion in the global C budget estimates. © 2014 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Pyrogenic organic matter production from wildfires: a missing sink in the global carbon cycle

PubMed Central

Santín, Cristina; Doerr, Stefan H; Preston, Caroline M; González-Rodríguez, Gil

2015-01-01

Wildfires release substantial quantities of carbon (C) into the atmosphere but they also convert part of the burnt biomass into pyrogenic organic matter (PyOM). This is richer in C and, overall, more resistant to environmental degradation than the original biomass, and, therefore, PyOM production is an efficient mechanism for C sequestration. The magnitude of this C sink, however, remains poorly quantified, and current production estimates, which suggest that ∽1-5% of the C affected by fire is converted to PyOM, are based on incomplete inventories. Here, we quantify, for the first time, the complete range of PyOM components found in-situ immediately after a typical boreal forest fire. We utilized an experimental high-intensity crown fire in a jack pine forest (Pinus banksiana) and carried out a detailed pre- and postfire inventory and quantification of all fuel components, and the PyOM (i.e., all visually charred, blackened materials) produced in each of them. Our results show that, overall, 27.6% of the C affected by fire was retained in PyOM (4.8 ± 0.8 t C ha−1), rather than emitted to the atmosphere (12.6 ± 4.5 t C ha−1). The conversion rates varied substantially between fuel components. For down wood and bark, over half of the C affected was converted to PyOM, whereas for forest floor it was only one quarter, and less than a tenth for needles. If the overall conversion rate found here were applicable to boreal wildfire in general, it would translate into a PyOM production of ∽100 Tg C yr−1 by wildfire in the global boreal regions, more than five times the amount estimated previously. Our findings suggest that PyOM production from boreal wildfires, and potentially also from other fire-prone ecosystems, may have been underestimated and that its quantitative importance as a C sink warrants its inclusion in the global C budget estimates. PMID:25378275

A 21 000-year record of fluorescent organic matter markers in the WAIS Divide ice core

NASA Astrophysics Data System (ADS)

D'Andrilli, Juliana; Foreman, Christine M.; Sigl, Michael; Priscu, John C.; McConnell, Joseph R.

2017-05-01

Englacial ice contains a significant reservoir of organic material (OM), preserving a chronological record of materials from Earth's past. Here, we investigate if OM composition surveys in ice core research can provide paleoecological information on the dynamic nature of our Earth through time. Temporal trends in OM composition from the early Holocene extending back to the Last Glacial Maximum (LGM) of the West Antarctic Ice Sheet Divide (WD) ice core were measured by fluorescence spectroscopy. Multivariate parallel factor (PARAFAC) analysis is widely used to isolate the chemical components that best describe the observed variation across three-dimensional fluorescence spectroscopy (excitation-emission matrices; EEMs) assays. Fluorescent OM markers identified by PARAFAC modeling of the EEMs from the LGM (27.0-18.0 kyr BP; before present 1950) through the last deglaciation (LD; 18.0-11.5 kyr BP), to the mid-Holocene (11.5-6.0 kyr BP) provided evidence of different types of fluorescent OM composition and origin in the WD ice core over 21.0 kyr. Low excitation-emission wavelength fluorescent PARAFAC component one (C1), associated with chemical species similar to simple lignin phenols was the greatest contributor throughout the ice core, suggesting a strong signature of terrestrial OM in all climate periods. The component two (C2) OM marker, encompassed distinct variability in the ice core describing chemical species similar to tannin- and phenylalanine-like material. Component three (C3), associated with humic-like terrestrial material further resistant to biodegradation, was only characteristic of the Holocene, suggesting that more complex organic polymers such as lignins or tannins may be an ecological marker of warmer climates. We suggest that fluorescent OM markers observed during the LGM were the result of greater continental dust loading of lignin precursor (monolignol) material in a drier climate, with lower marine influences when sea ice extent was higher and continents had more expansive tundra cover. As the climate warmed, the record of OM markers in the WD ice core changed, reflecting shifts in carbon productivity as a result of global ecosystem response.

Pitfalls in alignment of observation models resolved using PROV as an upper ontology

NASA Astrophysics Data System (ADS)

Cox, S. J. D.

2015-12-01

A number of models for observation metadata have been developed in the earth and environmental science communities, including OGC's Observations and Measurements (O&M), the ecosystems community's Extensible Observation Ontology (OBOE), the W3C's Semantic Sensor Network Ontology (SSNO), and the CUAHSI/NSF Observations Data Model v2 (ODM2). In order to combine data formalized in the various models, mappings between these must be developed. In some cases this is straightforward: since ODM2 took O&M as its starting point, their terminology is almost completely aligned. In the eco-informatics world observations are almost never made in isolation of other observations, so OBOE pays particular attention to groupings, with multiple atomic 'Measurements' in each oboe:Observation which does not have a result of its own and thus plays a different role to an om:Observation. And while SSN also adopted terminology from O&M, mapping is confounded by the fact that SSN uses DOLCE as its foundation and places ssn:Observations as 'Social Objects' which are explicitly disjoint from 'Events', while O&M is formalized as part of the ISO/TC 211 harmonised (UML) model and sees om:Observations as value assignment activities. Foundational ontologies (such as BFO, GFO, UFO or DOLCE) can provide a framework for alignment, but different upper ontologies can be based in profoundly different worldviews and use of incommensurate frameworks can confound rather than help. A potential resolution is provided by comparing recent studies that align SSN and O&M, respectively, with the PROV-O ontology. PROV-O provides just three base classes: Entity, Activity and Agent. om:Observation is sub-classed from prov:Activity, while ssn:Observation is sub-classed from prov:Entity. This confirms that, despite the same name, om:Observation and ssn:Observation denote different aspects of the observation process: the observation event, and the record of the observation event, respectively. Alignment with the simple PROV-O classes has clarified this issue in a way that had previously proved difficult to resolve. The simple 3-class base model from PROV appears to provide just enough logic to serve as a lightweight upper ontology, particularly for workflow or process-based information.

Biodiversity management of organic orchard enhances both ecological and economic profitability.

PubMed

Meng, Jie; Li, Lijun; Liu, Haitao; Li, Yong; Li, Caihong; Wu, Guanglei; Yu, Xiaofan; Guo, Liyue; Cheng, Da; Muminov, Mahmud A; Liang, Xiaotian; Jiang, Gaoming

2016-01-01

Organic farming has been regarded as an alternative solution for both agricultural sustainability and human health maintenance. Few researches have concentrated on the differences of biodiversity and eco-economic benefits between organic and conventional orchards. Organic management (OM) of orchards mainly includes taking advantage of natural enemies and beneficial weeds as well as soil organisms and controlling harmful pests. Here we conducted a three-year experiment on the effects of managing biodiversity in an organic apple orchard, using cattle manure to enrich soil biota, propagating native plant to suppress weeds and applying ecological pest management to control pests. The effect was assessed against the conventional management (CM) model. We found that OM enhanced soil organic carbon, total nitrogen, microbial biomass carbon and nitrogen. The 16S rDNA high-throughput sequencing results indicated that the dominant bacterial phyla of the top soil were Proteobacteria and Actinobacteria, and OM had richer bacteria diversity with a 7% higher Shannon's index than the CM. In particular, the relative abundance of rhizobium in the OM was higher than that of the CM. For OM, Duchesnea indica was an ideal ground-cover plant to control weeds through winning the niche competition and thus decreased weeds' Simpson, Shannon-Wiener and Pielou index by 38.2%, 53.8% and 16.9% separately. The phototactic pests' weight and scarab beetle's population were effectively decreased by 35% and 86% respectively through long time control and prevention. OM had an average of 20 times more earthworms than CM, and the maximum density had reached 369 m(-2) (0-20 cm soil). The dominant earthworm species of the OM were detritivores which preferring soil with high organic matter content. Due to no synthetic chemicals being used, the OM produced much safer apple fruits which were sold at high prices. Economically, up to a 103% increase of output-input ratio had been achieved in the OM. Our study clearly demonstrated that biodiversity management without chemical pollution increased the biodiversity of beneficial organisms, reduced antagonists of the fruit tree, and enhanced economic benefits of the apple orchard.

Biodiversity management of organic orchard enhances both ecological and economic profitability

PubMed Central

Meng, Jie; Li, Lijun; Liu, Haitao; Li, Yong; Li, Caihong; Wu, Guanglei; Yu, Xiaofan; Guo, Liyue; Cheng, Da; Muminov, Mahmud A.; Liang, Xiaotian

2016-01-01

Organic farming has been regarded as an alternative solution for both agricultural sustainability and human health maintenance. Few researches have concentrated on the differences of biodiversity and eco-economic benefits between organic and conventional orchards. Organic management (OM) of orchards mainly includes taking advantage of natural enemies and beneficial weeds as well as soil organisms and controlling harmful pests. Here we conducted a three-year experiment on the effects of managing biodiversity in an organic apple orchard, using cattle manure to enrich soil biota, propagating native plant to suppress weeds and applying ecological pest management to control pests. The effect was assessed against the conventional management (CM) model. We found that OM enhanced soil organic carbon, total nitrogen, microbial biomass carbon and nitrogen. The 16S rDNA high-throughput sequencing results indicated that the dominant bacterial phyla of the top soil were Proteobacteria and Actinobacteria, and OM had richer bacteria diversity with a 7% higher Shannon’s index than the CM. In particular, the relative abundance of rhizobium in the OM was higher than that of the CM. For OM, Duchesnea indica was an ideal ground-cover plant to control weeds through winning the niche competition and thus decreased weeds’ Simpson, Shannon–Wiener and Pielou index by 38.2%, 53.8% and 16.9% separately. The phototactic pests’ weight and scarab beetle’s population were effectively decreased by 35% and 86% respectively through long time control and prevention. OM had an average of 20 times more earthworms than CM, and the maximum density had reached 369 m−2 (0–20 cm soil). The dominant earthworm species of the OM were detritivores which preferring soil with high organic matter content. Due to no synthetic chemicals being used, the OM produced much safer apple fruits which were sold at high prices. Economically, up to a 103% increase of output–input ratio had been achieved in the OM. Our study clearly demonstrated that biodiversity management without chemical pollution increased the biodiversity of beneficial organisms, reduced antagonists of the fruit tree, and enhanced economic benefits of the apple orchard. PMID:27366643

Aerobic exercise training induces skeletal muscle hypertrophy and age-dependent adaptations in myofiber function in young and older men

PubMed Central

Konopka, Adam R.; Undem, Miranda K.; Hinkley, James M.; Minchev, Kiril; Kaminsky, Leonard A.; Trappe, Todd A.; Trappe, Scott

2012-01-01

To examine potential age-specific adaptations in skeletal muscle size and myofiber contractile physiology in response to aerobic exercise, seven young (YM; 20 ± 1 yr) and six older men (OM; 74 ± 3 yr) performed 12 wk of cycle ergometer training. Muscle biopsies were obtained from the vastus lateralis to determine size and contractile properties of isolated slow [myosin heavy chain (MHC) I] and fast (MHC IIa) myofibers, MHC composition, and muscle protein concentration. Aerobic capacity was higher (P < 0.05) after training in both YM (16 ± 2%) and OM (13 ± 3%). Quadriceps muscle volume, determined via MRI, was 5 ± 1 and 6 ± 1% greater (P < 0.05) after training for YM and OM, respectively, which was associated with an increase in MHC I myofiber cross-sectional area (CSA), independent of age. MHC I peak power was higher (P < 0.05) after training for both YM and OM, while MHC IIa peak power was increased (P < 0.05) with training in OM only. MHC I and MHC IIa myofiber peak and normalized (peak force/CSA) force were preserved with training in OM, while MHC I peak force/CSA and MHC IIa peak force were lower (P < 0.05) after training in YM. The age-dependent adaptations in myofiber function were not due to changes in protein content, as total muscle protein and myofibrillar protein concentration were unchanged (P > 0.05) with training. Training reduced (P < 0.05) the proportion of MHC IIx isoform, independent of age, whereas no other changes in MHC composition were observed. These data suggest relative improvements in muscle size and aerobic capacity are similar between YM and OM, while adaptations in myofiber contractile function showed a general improvement in OM. Training-related increases in MHC I and MHC IIa peak power reveal that skeletal muscle of OM is responsive to aerobic exercise training and further support the use of aerobic exercise for improving cardiovascular and skeletal muscle health in older individuals. PMID:22984247

The effect of thermal and organic additive in morphology of ceramic based silicate

NASA Astrophysics Data System (ADS)

Ginting, J.; Bangun, N.; Sembiring, H. Br; Putri, N. K.

2017-04-01

M-Silicate (M = Mg, Ca) has been prepared by exchange metal reaction from M-Chloride salts and sodium silicate. The resulting white solid of chloride salts then heated at 700, 800, 900 and 1000 °C. Due to increase the porosity of M-Silicate, 1,2-propanediol, oleic acid and glycerol were added, then formed M-silicates were heated at 800 °C. Then, obtained white solid M-Silicates were characterized by Scanning Electron Microscopy (SEM). SEM images show the variance of surface morphology when the temperature increases. The addition of organic compounds is involved in surface modification.

The utilization of waste by-products for removing silicate from mineral processing wastewater via chemical precipitation.

PubMed

Kang, Jianhua; Sun, Wei; Hu, Yuehua; Gao, Zhiyong; Liu, Runqing; Zhang, Qingpeng; Liu, Hang; Meng, Xiangsong

2017-11-15

This study investigates an environmentally friendly technology that utilizes waste by-products (waste acid and waste alkali liquids) to treat mineral processing wastewater. Chemical precipitation is used to remove silicate from scheelite (CaWO 4 ) cleaning flotation wastewater and the waste by-products are used as a substitute for calcium chloride (CaCl 2 ). A series of laboratory experiments is conducted to explain the removal of silicate and the characterization and formation mechanism of calcium silicate. The results show that silicate removal reaches 90% when the Ca:Si molar ratio exceeds 1.0. The X-ray diffraction (XRD) results confirm the characterization and formation of calcium silicate. The pH is the key factor for silicate removal, and the formation of polysilicic acid with a reduction of pH can effectively improve the silicate removal and reduce the usage of calcium. The economic analysis shows that the treatment costs with waste acid (0.63 $/m 3 ) and waste alkali (1.54 $/m 3 ) are lower than that of calcium chloride (2.38 $/m 3 ). The efficient removal of silicate is confirmed by industrial testing at a plant. The results show that silicate removal reaches 85% in the recycled water from tailings dam. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of nano-dispersive modified additive on cement activity

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

Sazonova, Natalya, E-mail: n.a.sazonova@mail.ru; Badenikov, Artem, E-mail: rector@agta.ru; Ivanova, Elizaveta, E-mail: lisik-iva@mail.ru

2016-01-15

In the work the influence of single-walled carbon nanotubes (SWCNT) on the cement activity and the processes of structure formation of the hardened cement paste in different periods of hydration are studied. The changes in the kinetic curves of the sample strength growth modified with SWCNT in amount of 0.01 and 0.0005 % are stipulated by the results of differential scanning colorimetry, scanning electronic and ionic microscopy, X-ray-phase analysis. It was found that the nano-modified additive may increase in the axis compressive strength of the system by 1.4–6.3 fold relatively to the reference samples and may reach 179.6 MPa. It maymore » intensify the hydration process of calcium silicates as well as influence on the matrix of hardened cement paste. The studies are conducted on the structural changes in the hardened cement paste, the time periods of increase and decrease of the compressive strength of the samples, the amount of the calcium hydroxide and tobermorite-like gel as well as the degree of hydration C{sub 3}S and β-C{sub 2}S.« less

Multidiffusion mechanisms for noble gases (He, Ne, Ar) in silicate glasses and melts in the transition temperature domain: Implications for glass polymerization

NASA Astrophysics Data System (ADS)

Amalberti, Julien; Burnard, Pete; Laporte, Didier; Tissandier, Laurent; Neuville, Daniel R.

2016-01-01

Noble gases are ideal probes to study the structure of silicate glasses and melts as the modifications of the silicate network induced by the incorporation of noble gases are negligible. In addition, there are systematic variations in noble gas atomic radii and several noble gas isotopes with which the influence of the network itself on diffusion may be investigated. Noble gases are therefore ideally suited to constrain the time scales of magma degassing and cooling. In order to document noble gas diffusion behavior in silicate glass, we measured the diffusivities of three noble gases (4He, 20Ne and 40Ar) and the isotopic diffusivities of two Ar isotopes (36Ar and 40Ar) in two synthetic basaltic glasses (G1 and G2; 20Ne and 36Ar were only measured in sample G1). These new diffusion results are used to re-interpret time scales of the acquisition of fractionated atmospheric noble gas signatures in pumices. The noble gas bearing glasses were synthesized by exposing the liquids to high noble gas partial pressures at high temperature and pressure (1750-1770 K and 1.2 GPa) in a piston-cylinder apparatus. Diffusivities were measured by step heating the glasses between 423 and 1198 K and measuring the fraction of gas released at each temperature step by noble gas mass spectrometry. In addition we measured the viscosity of G1 between 996 and 1072 K in order to determine the precise glass transition temperature and to estimate network relaxation time scales. The results indicate that, to a first order, that the smaller the size of the diffusing atom, the greater its diffusivity at a given temperature: D(He) > D(Ne) > D(Ar) at constant T. Significantly, the diffusivities of the noble gases in the glasses investigated do not display simple Arrhenian behavior: there are well-defined departures from Arrhenian behavior which occur at lower temperatures for He than for Ne or Ar. We propose that the non-Arrhenian behavior of noble gases can be explained by structural modifications of the silicate network itself as the glass transition temperature is approached: as the available free volume (available site for diffusive jumps) is modified, noble gas diffusion is no longer solely temperature-activated but also becomes sensitive to the kinetics of network rearrangements. The non-Arrhenian behavior of noble gas diffusion close to Tg is well described by a modified Vogel-Tammann-Fulcher (VTF) equation: Finally, our step heating diffusion experiments suggest that at T close to Tg, noble gas isotopes may suffer kinetic fractionation at a degree larger than that predicted by Graham's law. In the case of 40Ar and 36Ar, the traditional assumption based on Graham's law is that the ratio D40Ar/D36Ar should be equal to 0.95 (the square root of the ratio of the mass of 36Ar over the mass of 40Ar). In our experiment with glass G1, D40Ar/D36Ar rapidly decreased with decreasing temperature, from near unity (0.98 ± 0.14) at T > 1040 K to 0.76 when close to Tg (T = 1003 K). Replicate experiments are needed to confirm the strong kinetic fractionation of heavy noble gases close to the transition temperature.

Argillization by descending acid at Steamboat Springs, Nevada

USGS Publications Warehouse

Schoen, Robert; White, Donald E.; Hemley, J.J.

1974-01-01

Steamboat Springs, Nevada, an area of present-day hot springs, clearly illustrates the genetic dependence of some kaolin deposits on hot-spring activity. Andesite, granodiorite and arkosic sediments are locally altered at the land surface to siliceous residues consisting of primary quartz and anatase, plus opal from primary silicates. These siliceous residues commonly exhibit the textural and structural features of their unaltered equivalents. Beneath the siliceous residues, kaolin and alunite replace primary silicates and fill open spaces, forming a blanketlike deposit. Beneath the kaolin-alunite zone, montmorillonite, commonly accompanied by pyrite, replaces the primary silicates. On the ground surface, the same alteration mineral zones can be traced outward from the siliceous residue; however, hematite rather than pyrite accompanies montmorillonite.Chemical analysis indicates that sulfuric acid is the active altering agent. The acid forms from hydrogen sulfide that exsolves from deep thermal water, rises above the water table and is oxidized by sulfur-oxidizing bacteria living near the ground surface. This acid dissolves in precipitation or condensed water vapor and percolates downward destroying most of the primary minerals producing a siliceous residue. Coincidence of the water table with the downward transition from siliceous residue to kaolin-alunite signifies decreasing hydrogen metasomatism because of dilution of descending acid by ground water.In hot-spring areas, beds of siliceous sinter deposited at the surface by hypogene thermal water look, superficially, like areas of surficial acid alteration. Features diagnostic of a surficial alteration are the relict rock structures of a siliceous residue and a kaolin-alunite zone immediately beneath.

Influence of Silicate Melt Composition on Metal/Silicate Partitioning of W, Ge, Ga and Ni

NASA Technical Reports Server (NTRS)

Singletary, S. J.; Domanik, K.; Drake, M. J.

2005-01-01

The depletion of the siderophile elements in the Earth's upper mantle relative to the chondritic meteorites is a geochemical imprint of core segregation. Therefore, metal/silicate partition coefficients (Dm/s) for siderophile elements are essential to investigations of core formation when used in conjunction with the pattern of elemental abundances in the Earth's mantle. The partitioning of siderophile elements is controlled by temperature, pressure, oxygen fugacity, and by the compositions of the metal and silicate phases. Several recent studies have shown the importance of silicate melt composition on the partitioning of siderophile elements between silicate and metallic liquids. It has been demonstrated that many elements display increased solubility in less polymerized (mafic) melts. However, the importance of silicate melt composition was believed to be minor compared to the influence of oxygen fugacity until studies showed that melt composition is an important factor at high pressures and temperatures. It was found that melt composition is also important for partitioning of high valency siderophile elements. Atmospheric experiments were conducted, varying only silicate melt composition, to assess the importance of silicate melt composition for the partitioning of W, Co and Ga and found that the valence of the dissolving species plays an important role in determining the effect of composition on solubility. In this study, we extend the data set to higher pressures and investigate the role of silicate melt composition on the partitioning of the siderophile elements W, Ge, Ga and Ni between metallic and silicate liquid.

Tableting properties of silica aerogel and other silicates.

PubMed

Hentzschel, C M; Alnaief, M; Smirnova, I; Sakmann, A; Leopold, C S

2012-04-01

In solid oral dosage forms silicates are commonly used as glidants in low concentration. However, due to their large specific surface area, silicates may also be used as carrier materials for drugs. Moreover, silicates allow amorphisation of drugs by co-grinding or processing with supercritical fluids. The aim of this study was to investigate the physical and the tableting properties of Silica Aerogel (special type of silica with an extremely large specific surface area), Neusilin(®) US2 (magnesium aluminometasilicate), Florite(®) (calcium silicate) and Aerosil(®) 200 (colloidal silica). Powder blends of Avicel(®) PH102 (microcrystalline cellulose) and different amounts of the respective silicate were compacted and analyzed for their tabletability (tensile strength vs. compaction pressure) as well as their Heckel plot. With Neusilin(®) the tabletability appeared to be independent of the silicate concentration, whereas with Florite(®) an increasing silicate concentration led to a higher tensile strength. In contrast, the addition of Silica Aerogel and Aerosil(®) resulted in a decrease of the tensile strength. With Aerosil(®) a maximum tolerable concentration of 20% [w/w] was determined. Plastic deformation of all powder blends decreased with increasing silicate concentration. This effect was most pronounced with Aerosil(®) and least with Florite(®). Tablets with acceptable tensile strength were obtained with all plain silicates except for Aerosil(®). Therefore, these silicates may be used in tablet formulations, e.g. as carrier materials for liquid or amorphous drugs.

Organic carbon characteristics in density fractions of soils with contrasting mineralogies

NASA Astrophysics Data System (ADS)

Yeasmin, Sabina; Singh, Balwant; Johnston, Cliff T.; Sparks, Donald L.

2017-12-01

This study was aimed to evaluate the role of minerals in the preservation of organic carbon (OC) in different soil types. Sequential density fractionation was done to isolate particulate organic matter (POM, <1.8 g cm-3) and mineral associated OM (MOM: 1.8-2.2, 2.2-2.6 and >2.6 g cm-3) from four soils, i.e., a Ferralsol, a Luvisol, a Vertisol and a Solonetz. Organic matter (OM) in the density fractions was characterised using diffuse reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and mass spectroscopy in the original states (i.e., without any chemical pre-treatment), and after 6% sodium hypochlorite (NaOCl) and 10% hydrofluoric acid (HF) treatments. The NaOCl oxidation resistant fraction was considered as a relatively stable pool of OC and the HF soluble fraction was presumed as the mineral bound OC. Phyllosilicate-dominated soils, i.e., Vertisol, Luvisol and Solonetz, contained a greater proportion of POM than Fe and Al oxide-dominated Ferralsol. Wider C:N ratio and lower δ13C and δ15N in POM suggest the dominance of labile OC in this fraction and this was also supported by a greater proportion of NaOCl oxidised OC in the same fraction that was enriched with aliphatic C. The sequential density fractionation method effectively isolated OM into three distinct groups in the soils: (i) OM associated with Fe and Al oxides (>1.8 g cm-3 in the Ferralsol); (ii) OM associated with phyllosilicates (1.8-2.6 g cm-3) and (iii) OM associated with quartz and feldspar (>2.6 g cm-3) in the other three soils. Greater oxidation resistance, and more dissolution of OC during the HF treatment in the Fe and Al oxides dominated fractions suggest a greater potential of these minerals to protect OC from oxidative degradation as compared to the phyllosilicates, and quartz and feldspar matrices. OM associated with Fe and Al oxides was predominantly aromatic and carboxylate C. Decreased C:N ratio in the NaOCl oxidation resistant OM and HF soluble OM of phyllosilicates, and quartz and feldspars dominant fractions compared to their untreated fractions indicate a preferred retention of N rich organic compounds by these minerals. OM associated with phyllosilicates was enriched with protonated amide N and aromatic C. Quartz and feldspars associated OM comprised of N containing organic compounds and polysaccharides, although we don't expect any role of these minerals in their preservation. Our results imply that the abundance and surface properties of minerals in the soil largely control the dynamics of OC and subsequently protect OC from microbial cycling.

Regularities in Low-Temperature Phosphatization of Silicates

NASA Astrophysics Data System (ADS)

Savenko, A. V.

2018-01-01

The regularities in low-temperature phosphatization of silicates are defined from long-term experiments on the interaction between different silicate minerals and phosphate-bearing solutions in a wide range of medium acidity. It is shown that the parameters of the reaction of phosphatization of hornblende, orthoclase, and labradorite have the same values as for clayey minerals (kaolinite and montmorillonite). This effect may appear, if phosphotization proceeds, not after silicate minerals with a different structure and composition, but after a secondary silicate phase formed upon interaction between silicates and water and stable in a certain pH range. Variation in the parameters of the reaction of phosphatization at pH ≈ 1.8 is due to the stability of the silicate phase different from that at higher pH values.