Science.gov

Sample records for accumulated high concentrations

  1. Phytic Acid Synthesis and Vacuolar Accumulation in Suspension-Cultured Cells of Catharanthus roseus Induced by High Concentration of Inorganic Phosphate and Cations1[w

    PubMed Central

    Mitsuhashi, Naoto; Ohnishi, Miwa; Sekiguchi, Yoko; Kwon, Yong-Uk; Chang, Young-Tae; Chung, Sung-Kee; Inoue, Yoshinori; Reid, Robert J.; Yagisawa, Hitoshi; Mimura, Tetsuro

    2005-01-01

    We have established a new system for studying phytic acid, myo-inositol hexakisphosphate (InsP6) synthesis in suspension-cultured cells of Catharanthus. InsP6 and other intermediates of myo-inositol (Ins) phosphate metabolism were measured using an ion chromatography method. The detection limit for InsP6 was less than 50 nm, which was sufficient to analyze Ins phosphates in living cells. Synthesis of Ins phosphates was induced by incubation in high inorganic phosphate medium. InsP6 was mainly accumulated in vacuoles and was enhanced when cells were grown in high concentration of inorganic phosphates with the cations K+, Ca2+, or Zn2+. However, there was a strong tendency for InsP6 to accumulate in the vacuole in the presence of Ca2+ and in nonvacuolar compartments when supplied with Zn2+, possibly due to precipitation of InsP6 with Zn2+ in the cytosol. A vesicle transport inhibitor, brefeldin A, stimulated InsP6 accumulation. The amounts of both Ins(3)P1 myo-inositol monophosphate synthase, a key enzyme for InsP6 synthesis, and Ins(1,4,5)P3 kinase were unrelated to the level of accumulation of InsP6. The mechanisms for InsP6 synthesis and localization into vacuoles in plant cells are discussed. PMID:15965017

  2. Effects of high Zn and Pb concentrations on Phragmites australis (Cav.) Trin. Ex. Steudel: Photosynthetic performance and metal accumulation capacity under controlled conditions.

    PubMed

    Bernardini, A; Salvatori, E; Guerrini, V; Fusaro, L; Canepari, S; Manes, F

    2016-01-01

    The response of Phragmites australis (Cav.) Trin. Ex. Steudel to zinc (Zn) and lead (Pb) was studied separately in two hydroponic tests, during a three weeks experiment. The effects on ecophysiology and biomass partitioning were evaluated during the metal treatments and at the recovery, and total metal content and accumulation capacity in different plant organs were assessed. Zn and Pb had different effects on the overall measured parameters, highlighting different mechanism of action. In particular, Zn concentration was higher in roots and, being a micronutrient, it was translocated into leaves, producing a reduction of assimilation rate, stomatal conductance (-71.9 and -81.3% respect to the control plant respectively), and a strong down regulation of photosystems functionality both at PSII and PSI level. Otherwise, Pb was accumulated mainly in the more lignified tissue such as rhizomes, with slightly effect on gas exchange. Chlorophyll a fluorescence highlighted that Pb inhibits the electron transfer process at the PSI donor side, without recovery after the removal of the metal stress. Despite these physiological limitations, P. australis showed a high capacity to accumulate both metals, and only slight reduction of biomass, being therefore a suitable species for phytoremediation interventions. PMID:26114607

  3. Influence of high concentrations of mineral salts on production process and NaCl accumulation by Salicornia europaea plants as a constituent of the LSS phototroph link

    NASA Astrophysics Data System (ADS)

    Tikhomirova, N. A.; Ushakova, S. A.; Kovaleva, N. P.; Gribovskaya, I. V.; Tikhomirov, A. A.

    Use of halophytes (salt-tolerant vegetation), in a particular vegetable Salicornia europaea plants which are capable of utilizing NaCl in rather high concentrations, is one of possible means of NaCl incorporation into mass exchange of bioregenerative life support systems. In preliminary experiments it was shown that S. europaea plants, basically, could grow on urine pretreated with physicochemical processing and urease-enzyme decomposing of urea with the subsequent ammonia distillation. But at the same time inhibition of the growth process of the plants was observed. The purpose of the given work was to find out the influence of excessive quantities of some mineral elements contained in products of physicochemical processing of urine on the production process and NaCl accumulation by S. europaea plants. As the content of mineral salts in the human liquid wastes (urine) changed within certain limits, two variants of experimental solutions were examined. In the first variant, the concentration of mineral salts was equivalent to the minimum salt content in the urine and was: K - 1.5 g/l, P - 0.5 g/l, S - 0.5 g/l, Mg - 0.07 g/l, Ca - 0.2 g/l. In the second experimental variant, the content of mineral salts corresponded to the maximum salt content in urine and was the following: K - 3.0 g/l, P - 0.7 g/l, S - 1.2 g/l, Mg - 0.2 g/l, Ca - 0.97 g/l. As the control, the Tokarev nutrient solution containing nitrogen in the form of a urea, and the Knop nutrient solution with nitrogen in the nitrate form were used. N quantity in all four variants made up 177 mg/l. Air temperature was 24 °C, illumination was continuous. Light intensity was 690 μmol/m 2s of photosynthetically active radiation. NaCl concentration in solutions was 1%. Our researches showed that the dry aboveground biomass of an average plant of the first variant practically did not differ from the control and totaled 11 g. In the second variant, S. europaea productivity decreased and the dry aboveground biomass

  4. Influence of high concentrations of mineral salts on production process and NaCl accumulation by Salicornia europaea plants as a constituent of the LSS phototroph link

    NASA Astrophysics Data System (ADS)

    Tikhomirova, N. A.; Ushakova, S. A.; Kovaleva, N. P.; Gribovskaya, I. V.; Tikhomirov, A. A.

    Use of halophytes, in particular vegetable Salicornia europaea plants which are capable to utilize NaCl in rather high concentrations, is one of possible means of NaCl incorporation into mass exchange of biological life support systems (BLSS). In preliminary experiments it was shown, that S.europaea plants, basically, can grow on urine subjected to physicochemical processing and urease-fermentative decomposing of urea with the subsequent ammonia distillation, but for all that oppression of plants growth process was observed. In this connection, the purpose of the given work was to find out the influence of excessive quantity of some mineral elements contained in products of physicochemical processing of urine on production process and NaCl accumulation by S. europaea plants. As the content of mineral salts in the human's fluid excretions changed within certain limits two variants of modeling solutions were prepared. In the first variant concentration of mineral salts was equivalent to minimum salt content in the human's fluid excretions and compounded: K - 1,5 g/l, P - 0,5 g/l, S - 0,5 g/l, Mg - 0,07 g/l, Ca - 0,2 g/l. In the second variant the content of mineral salts corresponded to maximum salt content in the human's fluid excretions and was the following: K - 3,0 g/l, P - 0,7g/l, S - 1,2 g/l, Mg - 0,2 g/l, Ca - 0,97 g/l. As the control the modified solution under B.I.Tokarev's formulation containing nitrogen in the form of a urea, and Knop's solution with nitrogen in the nitrate form were used. N quantity in all 4 variants made up 177 mg/l. Air temperature was 24°, illumination was continuous. Light intensity was 150 W/m2 PAR. NaCl concentration in solutions compounded 1 %. The researches conducted showed that the dry above-ground biomass of an average plant of the first variant practically did not differ from the control and compounded 11,2 g. In the second variant S.europaea productivity decreased, and the dry above-ground biomass of an average plant

  5. Amazonian mid- to high-latitude glaciation on Mars: Supply-limited ice sources, ice accumulation patterns, and concentric crater fill glacial flow and ice sequestration

    NASA Astrophysics Data System (ADS)

    Fastook, James L.; Head, James W.

    2014-02-01

    Concentric crater fill (CCF) occurs in the interior of impact craters in mid- to high latitudes on Mars and is interpreted to have formed by glacial ice flow and debris covering. We use the characteristics and orientation of deposits comprising CCF, the thickness of pedestal deposits in mid- to high-latitude pedestal craters (Pd), the volumes of the current polar caps, and information about regional slopes and ice rheology to address questions about (1) the maximum thickness of regional ice deposits during the Late Amazonian, (2) the likelihood that these deposits flowed regionally, (3) the geological regions and features most likely to induce ice-flow, and (4) the locations and environments in which ice is likely to have been sequestered up to the present. We find that regional ice flow under Late Amazonian climate conditions requires ice thicknesses exceeding many hundreds of meters for slopes typical of the vast majority of the surface of Mars, a thickness for the mid-latitudes that is well in excess of the total volume available from polar ice reservoirs. This indicates that although conditions for mid- to high-latitude glaciation may have persisted for tens to hundreds of millions of years, the process is “supply limited”, with a steady state reached when the polar ice cap water ice supply becomes exhausted. Impact craters are by far the most abundant landform with associated slopes (interior wall and exterior rim) sufficiently high to induce glacial ice flow under Late Amazonian climate conditions, and topographic slope data show that Amazonian impact craters have been clearly modified, undergoing crater interior slope reduction and floor shallowing. We show that these trends are the predictable response of ice deposition and preferential accumulation and retention in mid- to high-latitude crater interiors during episodes of enhanced spin-axis obliquity. We demonstrate that flow from a single episode of an inter-crater terrain layer comparable to Pedestal

  6. Nucleotide Pyrophosphatase/Phosphodiesterase 1 Exerts a Negative Effect on Starch Accumulation and Growth in Rice Seedlings under High Temperature and CO2 Concentration Conditions

    PubMed Central

    Kaneko, Kentaro; Inomata, Takuya; Masui, Takahiro; Koshu, Tsutomu; Umezawa, Yukiho; Itoh, Kimiko; Pozueta-Romero, Javier; Mitsui, Toshiaki

    2014-01-01

    Nucleotide pyrophosphatase/phosphodiesterase (NPP) is a widely distributed enzymatic activity occurring in both plants and mammals that catalyzes the hydrolytic breakdown of the pyrophosphate and phosphodiester bonds of a number of nucleotides. Unlike mammalian NPPs, the physiological function of plant NPPs remains largely unknown. Using a complete rice NPP1-encoding cDNA as a probe, in this work we have screened a rice shoot cDNA library and obtained complete cDNAs corresponding to six NPP genes (NPP1–NPP6). As a first step to clarify the role of NPPs, recombinant NPP1, NPP2 and NPP6 were purified from transgenic rice cells constitutively expressing NPP1, NPP2 and NPP6, respectively, and their enzymatic properties were characterized. NPP1 and NPP6 exhibited hydrolytic activities toward ATP, UDP-glucose and the starch precursor molecule, ADP-glucose, whereas NPP2 did not recognize nucleotide sugars as substrates, but hydrolyzed UDP, ADP and adenosine 5′-phosphosulfate. To gain insight into the physiological function of rice NPP1, an npp1 knockout mutant was characterized. The ADP-glucose hydrolytic activities in shoots of npp1 rice seedlings were 8% of those of the wild type (WT), thus indicating that NPP1 is a major determinant of ADP-glucose hydrolytic activity in rice shoots. Importantly, when seedlings were cultured at 160 Pa CO2 under a 28°C/23°C (12 h light/12 h dark) regime, npp1 shoots and roots were larger than those of wild-type (WT) seedlings. Furthermore, the starch content in the npp1 shoots was higher than that of WT shoots. Growth and starch accumulation were also enhanced under an atmospheric CO2 concentration (40 Pa) when plants were cultured under a 33°C/28°C regime. The overall data strongly indicate that NPP1 exerts a negative effect on plant growth and starch accumulation in shoots, especially under high CO2 concentration and high temperature conditions. PMID:24092883

  7. Saccharomyces cerevisiae does not accumulate ethanol against a concentration gradient.

    PubMed Central

    Guijarro, J M; Lagunas, R

    1984-01-01

    It has been reported that yeast cells accumulate ethanol against a concentration gradient. We initiated a study of the mechanism involved in this phenomenon. However, we found that this accumulation does not occur and that ethanol permeates the yeast cell plasma membrane by simple diffusion. The following evidence supports this conclusion. (i) Uptake and outflow of ethanol in yeast cells followed first-order kinetics and were insensitive to the presence of structural analogs of ethanol, to drastic pH changes, and to the action of reagents of amino and thiol groups. These results strongly suggest that ethanol permeates the yeast cell plasma membrane without involvement of any carrier. (ii) The outflow rate of ethanol seems greater than the ability of this organism to produce ethanol, indicating that intracellular accumulation of ethanol is not possible. (iii) The intracellular concentration of ethanol found was similar to the concentration in culture media in all tested conditions. With the available information, it is difficult to ascertain the reasons for the discrepancy between our results and those previously reported by other authors. However, the inadequacy of the cell-sampling procedure and of the chromatographic conditions used by those authors suggests that the discrepancy may be due to artifacts in the measurements of ethanol. PMID:6389514

  8. Intracellular accumulation of boceprevir according to plasma concentrations and pharmacogenetics.

    PubMed

    Cusato, Jessica; Allegra, Sarah; De Nicolò, Amedeo; Boglione, Lucio; Fatiguso, Giovanna; Abdi, Adnan Mohamed; Cariti, Giuseppe; Di Perri, Giovanni; D'Avolio, Antonio

    2015-06-01

    Boceprevir (BOC) is a directly-acting antiviral agent for the treatment of hepatitis C virus genotype 1 (HCV-1) infection. It is a mixture of two stereoisomers, the inactive R and the active S isomers. No data have previously been published on BOC intracellular accumulation. In this study, BOC isomer concentrations in peripheral blood mononuclear cells (PBMCs) and plasma were determined. The influence of various single nucleotide polymorphisms (SNPs) on plasma and intracellular drug exposure at Week 4 of triple therapy were also evaluated. Plasma and intracellular BOC concentrations were determined at the end of the dosing interval (C(trough)) using a UPLC-MS/MS validated method. Allelic discrimination was performed through real-time PCR. Median plasma concentrations were 65.97 ng/mL for the S isomer and 36.31 ng/mL for the R isomer; the median S/R plasma concentration ratio was 1.66. The median PBMC concentration was 2285.88 ng/mL for the S isomer; the R isomer was undetectable within PBMCs. The median S isomer PBMC/plasma concentration ratio was 28.59. A significant positive correlation was found between plasma and PBMC S isomer concentrations. ABCB1 1236, SLC28A2 124 and IL28B rs12979860 SNPs were associated with the S isomer PBMC/plasma concentration ratio. In regression models, S isomer plasma levels and FokI polymorphism were able to predict S isomer intracellular exposure, whereas SNPs in AKR1, BCRP1 and SLC28A2 predicted the S isomer PBMC/plasma concentration ratio. No similar data regarding BOC pharmacogenetics and pharmacokinetics have been published previously. This study adds a novel and useful overview of the pharmacological properties of this drug. PMID:25836019

  9. Low acetate concentrations favor polyphosphate-accumulating organisms over glycogen-accumulating organisms in enhanced biological phosphorus removal from wastewater.

    PubMed

    Tu, Yunjie; Schuler, Andrew J

    2013-04-16

    Glycogen-accumulating organisms (GAOs) are thought to compete with polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) wastewater treatment systems. A laboratory sequencing batch reactor (SBR) was operated for one year to test the hypothesis that PAOs have a competitive advantage at low acetate concentrations, with a focus on low pH conditions previously shown to favor GAOs. PAOs dominated the system under conventional SBR operation with rapid acetate addition (producing high in-reactor concentrations) and pH values of 7.4-8.4. GAOs dominated when the pH was decreased (6.4-7.0). Decreasing the acetate addition rate led to very low reactor acetate concentrations, and PAOs recovered, supporting the study hypothesis. When the acetate feed rate was increased, EBPR failed again. Dominant PAOs and GAOs were Candidatus Accumulibacter phosphatis and Defluviicoccus Cluster 2, respectively, according to fluorescent in situ hybridization and 454 pyrosequencing. Surprisingly, GAOs were not the immediate causes of PAO failures, based on functional and population measurements. Pyrosequencing results suggested Dechloromonas and Tetrasphaera spp. may have also been PAOs, and additional potential GAOs were also identified. Full-scale systems typically have lower in-reactor acetate concentrations than laboratory SBRs, and so, previous laboratory studies may have overestimated the practical importance of GAOs as causes of EBPR failure. PMID:23477409

  10. Concentration is not enough to evaluate accumulation of heavy metals and nutrients in plants.

    PubMed

    Vymazal, Jan

    2016-02-15

    Wetland plants produce high aboveground biomass and possess the ability to accumulate heavy metals and nutrients. This ability is used for phytoremediation purposes including removal of nutrients and heavy metals from polluted waters. The concentrations of heavy metals are usually much higher in the belowground then in aboveground biomass, especially in roots which are primary sites of uptake. This may lead to the conclusion that accumulation of heavy metals is higher in the belowground biomass. However, in case the aboveground is much higher than belowground biomass the accumulation could be higher in the aboveground biomass. Concentration of nitrogen and phosphorus is always higher in leaves than in stems. However, the stem biomass is often much higher in robust emergent species such as Phragmites australis and therefore, more nutrients can be stored in stems. The examples shown in this communication clearly reveal that to evaluate properly the accumulation of heavy metals and nutrients in particular plant compartment biomass amount must be taken into consideration. In the first study, concentrations of Cd, Cr and Hg in Phalaris arundinacea belowground/aboveground biomass were 150/80μg/kg, 5420/228μg/kg and 38/18μg/kg. The high aboveground biomass (1196g/m(2)) and low belowground biomass (244g/(2)) resulted in much higher accumulation of Cd and Hg in aboveground biomass (96μg/m(2) and 21.2μg/m(2), respectively) than in belowground biomass (36μg/m(2) and 9.3μg/m(2), respectively). Only for chromium, belowground accumulation (1312μg/m(2)) was higher than aboveground accumulation (272μg/m(2)). In the second study, both nitrogen and phosphorus concentrations were higher (26.7mg/g and 749mg/kg, respectively) in leaves than in stems (8.2mg/g and 534mg/kg, respectively) of P. australis. The higher biomass of stems (1835g/m(2)) than leaves (967g/m(2)) resulted in higher accumulation of nitrogen but lower accumulation of phosphorus in leaves as compared to stems

  11. Impacts of CO2 concentration on growth, lipid accumulation, and carbon-concentrating-mechanism-related gene expression in oleaginous Chlorella.

    PubMed

    Fan, Jianhua; Xu, Hui; Luo, Yuanchan; Wan, Minxi; Huang, Jianke; Wang, Weiliang; Li, Yuanguang

    2015-03-01

    Biodiesel production by microalgae with photosynthetic CO2 biofixation is thought to be a feasible way in the field of bioenergy and carbon emission reduction. Knowledge of the carbon-concentrating mechanism plays an important role in improving microalgae carbon fixation efficiency. However, little information is available regarding the dramatic changes of cells suffered upon different environmental factors, such as CO2 concentration. The aim of this study was to investigate the growth, lipid accumulation, carbon fixation rate, and carbon metabolism gene expression under different CO2 concentrations in oleaginous Chlorella. It was found that Chlorella pyrenoidosa grew well under CO2 concentrations ranging from 1 to 20 %. The highest biomass and lipid productivity were 4.3 g/L and 107 mg/L/day under 5 % CO2 condition. Switch from high (5 %) to low (0.03 %, air) CO2 concentration showed significant inhibitory effect on growth and CO2 fixation rate. The amount of the saturated fatty acids was increased obviously along with the transition. Low CO2 concentration (0.03 %) was suitable for the accumulation of saturated fatty acids. Reducing the CO2 concentration could significantly decrease the polyunsaturated degree in fatty acids. Moreover, the carbon-concentrating mechanism-related gene expression revealed that most of them, especially CAH2, LCIB, and HLA3, had remarkable change after 1, 4, and 24 h of the transition, which suggests that Chlorella has similar carbon-concentrating mechanism with Chlamydomonas reinhardtii. The findings of the present study revealed that C. pyrenoidosa is an ideal candidate for mitigating CO2 and biodiesel production and is appropriate as a model for mechanism research of carbon sequestration. PMID:25620370

  12. Anaerobic biodegradability and digestion in accumulation systems for concentrated black water and kitchen organic-wastes.

    PubMed

    Elmitwalli, T A; van Leeuwen, M; Kujawa-Roeleveld, K; Sanders, W; Zeeman, G

    2006-01-01

    The feasibility of two accumulation-systems (AC) for anaerobic digestion and storage of concentrated black water with (AC1) or without (AC2) urine + kitchen organic-wastes was investigated. The waste(water) was collected by two vacuum toilet/transport systems. The influent-total COD of the AC2 (53,000 mg/L) was more concentrated by four times than that of the AC1. The suspended COD represented the major part (71-73%) of influent total COD of the two systems. The batch-experiments results showed a high anaerobic biodegradability of the waste(water) (> 85%). The AC systems demonstrated stable performance. There was no inhibition effect of NH4 and VFA concentration decreased in time. Total COD removal of 58% was achieved in both systems, after 105 days at 20 degrees C. Moreover, if only the supernatant in AC1 is withdrawn and the settled sludge stays for the next runs, only 20% of the influent total COD will be in the supernatant. In AC2, 74% of influent ortho-P was removed by precipitation. Therefore, the settled sludge in the AC2 had a high total-P concentration of 1,300 mg/L. The C:N:P ratios of the supernatant and the sludge were 26:13:1 and 35:4.5:1, respectively, in the AC1, and were 28:14:1 and 32:2.4:1, respectively, in AC2. PMID:16784201

  13. Reverse osmosis concentrate treatment via a PAC-MF accumulative countercurrent adsorption process.

    PubMed

    Zhao, Chunxia; Gu, Ping; Cui, Hangyu; Zhang, Guanghui

    2012-01-01

    Organic pollutants in reverse osmosis (RO) concentrates from wastewater reclamation are mainly comprised of low molecular weight biorefractory compounds. Generally, advanced oxidation methods for oxidizing these organics require a relatively high level of energy consumption. In addition, conventional adsorption removal methods require a large dose of activated carbon. However, the dose can be reduced if its full adsorption capacity can be used. Therefore, the combined technology of powdered activated carbon (PAC) adsorption and microfiltration (MF) membrane filtration was studied to develop a countercurrent two-stage adsorption process. A PAC accumulative adsorption prediction method was proposed based on the verification of a PAC multi-stage adsorption capacity equation. Moreover, the prediction method was amended for a more accurate prediction of the effluent quality because adsorption isotherm constants were affected by the initial adsorbate concentration. The required PAC dose for the accumulative countercurrent two-stage adsorption system was 0.6 g/L, whereas that of the conventional adsorption process was 1.05 g/L when the dilution factor(F) was 0.1 and the COD and DOC removal rates were set to 70% and 68.1%, respectively. Organic pollutants were satisfactorily removed with less consumption of PAC. Effluent from this combined technology can be further reclaimed by an RO process to improve the overall recovery rate to between 91.0% and 93.8% with both economic and environmental benefits. PMID:22082527

  14. Cellular Concentrations and Uniformity of Cell-Type Accumulation of Two Lea Proteins in Cotton Embryos.

    PubMed Central

    Roberts, JK; DeSimone, NA; Lingle, WL; Dure, L

    1993-01-01

    The levels and cell-type distribution of late embryogenesis abundant (Lea) proteins D-7 and D-113 have been determined in mature cotton embryos by immunochemical methods. The two proteins were expressed in and purified from Escherichia coli and utilized for antibody production in rabbits. The antiserum to each protein was found to interact with all members of each protein family in cotton extracts by protein gel blotting. Using these antibodies in quantitative "rocket" immunoelectrophoreses, D-7 proteins were found to accumulate to ~8 x 1015 molecules per embryo, which is equivalent to ~109 molecules per "average cell." D-113 proteins accumulate to ~1016 molecules per embryo, which equates to ~1.3 x 109 molecules per average cell. These values calculate to concentrations of about 226 and 283 [mu]M, respectively, in the cell aqueous phase immediately prior to seed desiccation. In immunocytochemical studies using the fluorophor rhodamine linked to the secondary antibody, both proteins appeared to be evenly present in the cytosol of all cell types present in the embryo, including both cotyledon and axis epidermal cells. Thus, their function does not appear related to unique functions of specific cell or tissue types. The very high molar concentrations of the two proteins, coupled with their unusual predicted structure and their cytosol location, would seem to reduce the number of their conceivable functions. PMID:12271086

  15. Novel Approaches for the Accumulation of Oxygenated Intermediates to Multi-Millimolar Concentrations

    PubMed Central

    Krebs, Carsten; Dassama, Laura M. K.; Matthews, Megan L.; Jiang, Wei; Price, John C.; Korboukh, Victoria; Li, Ning; Bollinger, J. Martin

    2012-01-01

    Metalloenzymes that utilize molecular oxygen as a co-substrate catalyze a wide variety of chemically difficult oxidation reactions. Significant insight into the reaction mechanisms of these enzymes can be obtained by the application of a combination of rapid kinetic and spectroscopic methods to the direct structural characterization of intermediate states. A key limitation of this approach is the low aqueous solubility (< 2 mM) of the co-substrate, O2, which undergoes further dilution (typically by one-third or one-half) upon initiation of reactions by rapid-mixing. This situation imposes a practical upper limit on [O2] (and therefore on the concentration of reactive intermediate(s) that can be rapidly accumulated) of ∼1-1.3 mM in such experiments as they are routinely carried out. However, many spectroscopic methods benefit from or require significantly greater concentrations of the species to be studied. To overcome this problem, we have recently developed two new approaches for the preparation of samples of oxygenated intermediates: (1) direct oxygenation of reduced metalloenzymes using gaseous O2 and (2) the in situ generation of O2 from chlorite catalyzed by the enzyme chlorite dismutase (Cld). Whereas the former method is applicable only to intermediates with half lives of several minutes, owing to the sluggishness of transport of O2 across the gas-liquid interface, the latter approach has been successfully applied to trap several intermediates at high concentration and purity by the freeze-quench method. The in situ approach permits generation of a pulse of at least 5 mM O2 within ∼ 1 ms and accumulation of O2 to effective concentrations of up to ∼ 11 mM (i.e. ∼ 10-fold greater than by the conventional approach). The use of these new techniques for studies of oxygenases and oxidases is discussed. PMID:24368870

  16. Heavy metals in plants in constructed and natural wetlands: concentration, accumulation and seasonality.

    PubMed

    Vymazal, J; Březinová, T

    2015-01-01

    The accumulation of heavy metals in plants is a function of uptake capacity and intracellular binding sites. The concentrations of heavy metals in plants growing in constructed wetlands vary considerably between species and systems but in general, the concentrations are within the range commonly found in natural stands. The highest concentrations are mostly found in roots, followed by rhizomes, leaves and stems. Unfortunately, concentration values are commonly used to evaluate the 'accumulation' of heavy metals, but this approach is not correct. In order to evaluate heavy metal accumulation, the biomass of particular plant parts must be taken into consideration. In addition, there are two other factors, which need to be taken into consideration when accumulation is evaluated, namely seasonality and distribution within the plant shoot. It has been found that the seasonal distribution of heavy metals in the biomass varies between heavy metals and mostly does not follow the pattern known for nutrients. In addition, the concentration and accumulation of heavy metals vary considerably within the shoot and this fact should be taken into consideration when analyses are carried out. PMID:25633951

  17. Accumulation of polychlorobiphenyl congeners and p,p'-DDE at environmental concentrations by corn and beans

    SciTech Connect

    Shane, L.A.; Bush, B.

    1989-02-01

    The uptake of polychlorinated biphenyl (PCB) congeners present at low concentrations in the environment was investigated in leaf composites of four crop species and final fruits at two sites. All four species preferentially accumulated the same eight congeners, although not in the same degree or rank. No bean species demonstrated a significant increase in accumulation over time, and corn significantly reduced its PCB load over time. Mechanisms are suggested for such behavior. Fruits were 100 times less contaminated than plant leaves.

  18. Lethal body concentrations and accumulation patterns determine time-dependent toxicity of cadmium in soil arthropods

    SciTech Connect

    Crommentuijn, T.; Doodeman, C.J.A.M.; Doornekamp, A.; Pol, J.J.C. van der; Bedaux, J.J.M.; Gestel, C.A.M. van )

    1994-11-01

    Time-dependent toxicity in bioassays is usually explained in terms of uptake and elimination kinetics of the toxicant. By comparing different species with essentially different accumulation kinetics, a firm test of this concept may be made. This article compares the sensitivity of six soil arthropods, the collembolans Orchesella cincta and Tomocerus minor, the oribatid mite Platynothrus peltifer, the isopods Porcellio scaber and Oniscus asellus, and the diplopod Cylindroiulus britannicus, when exposed to cadmium in the food. Survival was determined at various time intervals; accumulation of cadmium in the animals was measured at one time interval. Kinetic-based toxicity models were fitted to the data, and estimates were obtained for lethal body concentration, uptake rate constant, elimination rate constant, and ultimate LC50. Two different accumulation patterns could be discerned; these were correlated with time-survival relationships. One, species that have the possibility to eliminate cadmium will reach an equilibrium for the internal concentration and also an ultimate LC50. Two, species that are unable to eliminate cadmium but store it in the body will have an ultimate LC50 equal to zero. For these species the time in which the lethal body concentration is reached is more important. Taxonomically related species appeared to have comparable accumulation patterns, but lethal body concentrations differed. It is concluded that knowledge of the accumulation pattern is indispensable for the evaluation of species' sensitivities to toxicants.

  19. Advanced high efficiency concentrator cells

    SciTech Connect

    Gale, R. . Varian Research Center)

    1992-06-01

    This report describes research to develop the technology needed to demonstrate a monolithic, multijunction, two-terminal, concentrator solar cell with a terrestrial power conversion efficiency greater than 35%. Under three previous subcontracts, Varian developed many of the aspects of a technology needed to fabricate very high efficiency concentrator cells. The current project was aimed at exploiting the new understanding of high efficiency solar cells. Key results covered in this report are as follows. (1) A 1.93-eV AlGaAs/1.42-eV GaAs metal-interconnected cascade cell was manufactured with a one-sun efficiency at 27.6% at air mass 1.5 (AM1.5) global. (2) A 1.0eV InGaAs cell was fabricated on the reverse'' side of a low-doped GaAs substrate with a one-sun efficiency of 2.5% AM1.5 diffuse and a short-circuit current of 14.4 mA/cm{sup 2}. (3) Small-scale manufacturing of GaAs p/n concentrator cells was attempted and obtained an excellent yield of high-efficiency cells. (4) Grown-in tunnel junction cell interconnects that are transparent and thermally stable using C and Si dopants were developed. 10 refs.

  20. Impurity accumulation in plasma regimes with high energy confinement

    NASA Astrophysics Data System (ADS)

    Ran, L. B.; Roberts, D. E.; Yang, H. R.; Dodel, G.; Gentle, K.; Von Goeler, S.; Holzhauer, E.; Hübner, K.; Keilhacker, M.; Korotkov, A.; Luce, T. C.; Miura, Y.; Tsois, N.; Würz, H.; Fussmann, G.; Hofmann, J.; Janeschitz, G.; Krieger, K.; Müller, E. R.; Nolte, R.; Röhr, H.; Steuer, K. H.; Becker, G.; Bomba, B.; Bruhns, H.; Büchl, K.; Carlson, A.; Eberhagen, A.; Fahrbach, H.-U.; Gehre, O.; Gernhardt, J.; Giannone, L.; Von Gierke, G.; Glock, E.; Gruber, O.; Haas, G.; Herrmann, H.; Kaesdorf, S.; Karger, F.; Kaufmann, M.; Klüber, O.; Kornherr, M.; Lackner, K.; Lang, R.; Lee, P.; Lisitano, G.; Mast, F.; Mayer, H. M.; McCormick, K.; Meisel, D.; Mertens, V.; Murmann, H.; Neuhauser, J.; Niedermeyer, H.; Noterdaeme, J. M.; Poschenrieder, W.; Preis, R.; Rapp, H.; Rudyj, A.; Sandmann, W.; Schneider, F.; Schnider, U.; Siller, G.; Simmet, E.; Speth, E.; Söldner, F.; Stäbler, A.; Steinmetz, K.; Stroth, U.; Vollmer, O.; Zasche, D.

    1989-04-01

    Investigations of impurity accumulation phenomena in ASDEX are reviewed. There are four different operating regimes where pronounced accumulation is observed and these regimes are also characterized by improved energy confinement. In particular, medium-Z metallic ions are involved in accumulation processes whereas low-Z ions appear almost unaffected. The rapid accumulation observed in the case of metallic ions may be explained by neoclassical inward drifts if we assume that the anomalous diffusion is sufficiently suppressed, some indication of this being found from laser blow-off studies. The present results, however, can only be partly explained by neoclassical theory, according to which accumulation of low-Z impurities should also occur. The temporal behaviour of accumulation and the retarding effect of proton dilution for collision dominated transport are also discussed. Finally, we conclude that the full benefits of improved energy confinement can be achieved only if the impurity influxes are kept to a sufficiently low level. Expressed in terms of concentrations under low confinement conditions we have to postulate, for ASDEX, concentrations ≲ 10 -4 for metals and ≲ 2% for all light impurities.

  1. Effect of nitrogen and/or oxygen concentration on poly(3-hydroxybutyrate) accumulation by Halomonas boliviensis.

    PubMed

    García-Torreiro, María; Lu-Chau, Thelmo A; Lema, Juan M

    2016-09-01

    The behaviour of Halomonas boliviensis during growth in fed-batch culture under different kind of nutrient restrictions was examined. The metabolic switch between growth and accumulation phase is determined by the limitation in one or more essential nutrient for bacterial growth. The aim of this study was to test the effect of applying limitations of a essential nutrient, such as nitrogen, and the influence of different O2 concentrations on poly(3-hydroxybutyrate) (PHB) production during the accumulation phase. Single limitations of nitrogen and oxygen provoke PHB accumulations of 45 and 37 % (g g(-1)), respectively, while N limitation with low O2 supply causes the highest PHB accumulation of 73 %. The characterization of the PHB production with the strain H. boliviensis would allow a better optimization of the process and enrich the knowledge about the PHB production from strains different than Cupriavidus necator. PMID:27126501

  2. Damage accumulation in ion-irradiated Ni-based concentrated solid-solution alloys

    DOE PAGESBeta

    Ullah, Mohammad W.; Aidhy, Dilpuneet S.; Zhang, Yanwen; Weber, William J.

    2016-01-01

    We investigate Irradiation-induced damage accumulation in Ni0.8Fe0.2 and Ni0.8Cr0.2 alloys by using molecular dynamics simulations to assess possible enhanced radiation-resistance in these face-centered cubic (fcc), single-phase, concentrated solid-solution alloys, as compared with pure fcc Ni.

  3. Effects of environmental and physiological variables on the accumulated concentrations of trace metals in the New Zealand cockle Austrovenus stutchburyi.

    PubMed

    Marsden, Islay D; Smith, Brian D; Rainbow, Phillip S

    2014-02-01

    We examined potential causes of variation in trace element accumulation in an estuarine bivalve Austrovenus stutchburyi from two estuarine systems in South Island, New Zealand which differed in their metal contamination and salinity regimes. Concentrations of Ag, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Ti, V and Zn were measured (ICP-OES) in whole body tissues of bivalves collected from 10 sites, seston collected at high tide (a potential food resource) and in the sediment at the sites. All 13 elements showed a relationship between log bioaccumulated trace element concentration (mgkg(-1) dry weight tissue) and log shell length (mm), either in the whole data set or at least one site (ANCOVA). Growth rates of cockles varied significantly amongst sites. Accumulated soft tissue concentrations of Ag, As, Co and Cr increased with age of cockle, those of Pb and Zn decreased, with no clear age-related trend for the remaining metals (ANCOVA). Shell length was generally a good proxy for age when allowing for any size effect in metal accumulation by the cockle. There was no consistent pattern between the estuarine systems, probably reflecting unidentified contaminant inputs. Following depuration, tissue concentrations decreased significantly for some elements (Fe, Mn, Ti and V), indicating high concentrations of these metals in the gut contents. Trace element concentrations in the seston generally did not correlate with the bivalve tissue concentrations. There were few (Spearman's Rank) correlations between environmental variables at the time of sampling and cockle tissue trace element concentrations. The main sources of variation in bioaccumulated trace metal concentrations in the whole tissues of the cockle are location, shell length and age. PMID:24144937

  4. Non-tracking solar concentrator with a high concentration ratio

    DOEpatents

    Hinterberger, Henry

    1977-01-01

    A nontracking solar concentrator with a high concentration ratio is provided. The concentrator includes a plurality of energy absorbers which communicate with a main header by which absorbed heat is removed. Undesired heat flow of those absorbers not being heated by radiant energy at a particular instant is impeded, improving the efficiency of the concentrator.

  5. Transient concentrations of NaCl affect the PHA accumulation in mixed microbial culture.

    PubMed

    Palmeiro-Sánchez, T; Fra-Vázquez, A; Rey-Martínez, N; Campos, J L; Mosquera-Corral, A

    2016-04-01

    The present study explores the feasibility of the accumulation of polyhydroxyalkanoates (PHAs) under the presence of transient concentrations of added sodium chloride, by means of a mixed microbial culture (MMC). This culture was enriched on a mixture of volatile fatty acids (VFAs) containing 0.8g Na(+)/L as NaOH. This MMC presented a maximum PHA accumulation capacity of 53wt% with 27Cmol% HV. Accumulation experiments performed with added NaCl at concentrations of 7, 13 and 20g/L shown that this salt provoked a decrease of the biomass PHA production rate, with an IC50 value close to 7gNaCl/L. The accumulated PHA was lower than the corresponding value of the assay without the addition of salt. Furthermore, the composition of the biopolymer, in terms of HB:HV ratio, changed from 2.71 to 6.37Cmol/Cmol, which means a HV decrease between 27 and 14Cmol%. Summarizing, the PHA accumulation by a MMC non-adapted to saline conditions affected the polymer composition and lead to lower production yields and rates than in absence of added NaCl. PMID:26780589

  6. Metal accumulation and metallothionein concentrations in tree swallow nestlings near acidified lakes

    SciTech Connect

    St. Louis, V.; Breebaart, L. . Dept. of Zoology); Barlow, J.C. . Dept. of Zoology Royal Ontario Museum, Toronto, Ontario . Dept. of Ornithology); Klaverkamp, J.F. . Dept. of Fisheries and Oceans)

    1993-07-01

    The authors studied metal accumulation in hepatic and renal tissues of tree swallow (Tachycineta bicolor) nestlings at acidified and nonacid reference lakes in northwestern Ontario. Hepatic concentrations of metallothionein (metal-binding proteins, MT) in tree swallow nestlings were negatively correlated with pH of the nest-site lake. Combined concentrations of Cu and Zn in the liver were correlated with liver MT concentrations, but Cd was not. Although no overt signs of metal toxicity were observed in nestlings near acid lakes, the results clearly provided evidence that metals are transferred from acid lakes to birds and that these metals are correlated with increases in hepatic MT production.

  7. Rainy Periods and Bottom Water Stagnation Initiating Brine Accumulation and Metal Concentrations: 1. The Late Quaternary

    NASA Astrophysics Data System (ADS)

    Rossignol-Strick, Martine

    1987-06-01

    feedback of stagnation by increased density progressively raised the salinity of entrapped bottom waters to the present brine concentration. The high density has resisted brine removal by bottom circulation until present time, long after cessation of the initiating wet period. The brines therefore are stagnant, fossil waters.

  8. Peatlands as Dynamic Biogeochemical Ecotones: Elemental Concentrations, Stoichiometries and Accumulation in Peatland Soils of Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Moore, T. R.; Wang, M.; Talbot, J.; Riley, J. L.

    2015-12-01

    Peatlands act as biogeochemical interfaces between terrestrial and aquatic systems and are 'hotspots', particularly for carbon cycling and the accumulation of nutrients and other elements within the peat profile. This results in storage of substantial amounts of carbon, nutrients and metals, particularly in northern peatlands. Using a data base of over 400 peat profiles and 1700 individual peat samples from bog, fen and swamp sites in Ontario, Canada, we examine the profile concentrations of C, N, P, Ca, Mg, K, Hg, Pb, As, Cu, Mn, Zn, Fe and Al, and estimate the storage and accumulation of these elements. We show how these profiles, spatial patterns, stoichiometries and accumulation rates are controlled by biogeochemical processes and influenced by geochemical setting, hydrology, atmospheric input and pollution, and ecological and microbial transformations.

  9. Dry matter and nitrogen accumulation are not affected by superoptimal concentration of ammonium in flowing solution culture with pH control

    NASA Technical Reports Server (NTRS)

    Rideout, J. W.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1994-01-01

    While it is known that superoptimal concentrations of the nitrate (NO3-) ion in solution culture do not increase NO3- uptake or dry matter accumulation, the same is not known for the ammonium (NH4+) ion. An experiment was conducted utilizing flowing solution culture with pH control to investigate the influence of superoptimal NH4+ concentrations on dry matter, nitrogen (N), potassium (K), calcium (Ca), and magnesium (Mg) accumulation by nonnodulated soybean plants. Increasing the NH4+ concentration in solution from 1 to 10 mM did not affect dry matter or N accumulation. Accumulations of K, Ca, and Mg were slightly decreased with increased NH4+ concentration. The NH4+ uptake system, which is saturated at less than 1mM NH4+, is able to regulate uptake of NH4+ at concentrations as high as 10 mM.

  10. Effects of water management on cadmium and arsenic accumulation and dimethylarsinic acid concentrations in Japanese rice.

    PubMed

    Arao, Tomohito; Kawasaki, Akira; Baba, Koji; Mori, Shinsuke; Matsumoto, Shingo

    2009-12-15

    Rice consumption is a major source of cadmium and arsenic for the population of Asia. We investigated the effects of water management in rice paddy on levels of cadmium and arsenic in Japanese rice grains. Flooding increased arsenic concentrations in rice grains, whereas aerobic treatment increased the concentration of cadmium. Flooding for 3 weeks before and after heading was most effective in reducing grain cadmium concentrations, but this treatment increased the arsenic concentration considerably, whereas aerobic treatment during the same period was effective in reducing arsenic concentrations but increased the cadmium concentration markedly. Flooding treatment after heading was found to be more effective than flooding treatment before heading in reducing rice grain cadmium without a concomitant increase in total arsenic levels, although it increased inorganic arsenic levels. Concentrations of dimethylarsinic acid (DMA) in grain were very low under aerobic conditions but increased under flooded conditions. DMA accounted for 3-52% of the total arsenic concentration in grain grown in soil with a lower arsenic concentration and 10-80% in soil with a higher arsenic concentration. A possible explanation for the accumulation of DMA in rice grains is that DMA translocates from shoots/roots to the grains more readily than does inorganic arsenic. PMID:20000530

  11. Damage accumulation in ion-irradiated Ni-based concentrated solid-solution alloys

    SciTech Connect

    Ullah, Mohammad W.; Aidhy, Dilpuneet S.; Zhang, Yanwen; Weber, William J.

    2016-01-01

    We investigate Irradiation-induced damage accumulation in Ni0.8Fe0.2 and Ni0.8Cr0.2 alloys by using molecular dynamics simulations to assess possible enhanced radiation-resistance in these face-centered cubic (fcc), single-phase, concentrated solid-solution alloys, as compared with pure fcc Ni.

  12. Ultra-High-Speed Image Signal Accumulation Sensor

    PubMed Central

    Etoh, Takeharu Goji; Son, Dao Vu Truong; Akino, Toshiaki Koike; Akino, Toshiro; Nishi, Kenji; Kureta, Masatoshi; Arai, Masatoshi

    2010-01-01

    Averaging of accumulated data is a standard technique applied to processing data with low signal-to-noise ratios (SNR), such as image signals captured in ultra-high-speed imaging. The authors propose an architecture layout of an ultra-high-speed image sensor capable of on-chip signal accumulation. The very high frame rate is enabled by employing an image sensor structure with a multi-folded CCD in each pixel, which serves as an in situ image signal storage. The signal accumulation function is achieved by direct connection of the first and the last storage elements of the in situ storage CCD. It has been thought that the multi-folding is achievable only by driving electrodes with complicated and impractical layouts. Simple configurations of the driving electrodes to overcome the difficulty are presented for two-phase and four-phase transfer CCD systems. The in situ storage image sensor with the signal accumulation function is named Image Signal Accumulation Sensor (ISAS). PMID:22319344

  13. Life at high salt concentrations, intracellular KCl concentrations, and acidic proteomes

    PubMed Central

    Oren, Aharon

    2013-01-01

    Extremely halophilic microorganisms that accumulate KCl for osmotic balance (the Halobacteriaceae, Salinibacter) have a large excess of acidic amino acids in their proteins. This minireview explores the occurrence of acidic proteomes in halophiles of different physiology and phylogenetic affiliation. For fermentative bacteria of the order Halanaerobiales, known to accumulate KCl, an acidic proteome was predicted. However, this is not confirmed by genome analysis. The reported excess of acidic amino acids is due to a high content of Gln and Asn, which yield Glu and Asp upon acid hydrolysis. The closely related Halorhodospira halophila and Halorhodospira halochloris use different strategies to cope with high salt. The first has an acidic proteome and accumulates high KCl concentrations at high salt concentrations; the second does not accumulate KCl and lacks an acidic proteome. Acidic proteomes can be predicted from the genomes of some moderately halophilic aerobes that accumulate organic osmotic solutes (Halomonas elongata, Chromohalobacter salexigens) and some marine bacteria. Based on the information on cultured species it is possible to understand the pI profiles predicted from metagenomic data from hypersaline environments. PMID:24204364

  14. Effects of high ammonium level on biomass accumulation of common duckweed Lemna minor L.

    PubMed

    Wang, Wenguo; Yang, Chuang; Tang, Xiaoyu; Gu, Xinjiao; Zhu, Qili; Pan, Ke; Hu, Qichun; Ma, Danwei

    2014-12-01

    Growing common duckweed Lemna minor L. in diluted livestock wastewater is an alternative option for pollutants removal and consequently the accumulated duckweed biomass can be used for bioenergy production. However, the biomass accumulation can be inhibited by high level of ammonium (NH4 (+)) in non-diluted livestock wastewater and the mechanism of ammonium inhibition is not fully understood. In this study, the effect of high concentration of NH4 (+) on L. minor biomass accumulation was investigated using NH4 (+) as sole source of nitrogen (N). NH4 (+)-induced toxicity symptoms were observed when L. minor was exposed to high concentrations of ammonium nitrogen (NH4 (+)-N) after a 7-day cultivation. L. minor exposed to the NH4 (+)-N concentration of 840 mg l(-1) exhibited reduced relative growth rate, contents of carbon (C) and photosynthetic pigments, and C/N ratio. Ammonium irons were inhibitory to the synthesis of photosynthetic pigments and caused C/N imbalance in L. minor. These symptoms could further cause premature senescence of the fronds, and restrain their reproduction, growth and biomass accumulation. L. minor could grow at NH4 (+)-N concentrations of 7-84 mg l(-1) and the optimal NH4 (+)-N concentration was 28 mg l(-1). PMID:25056754

  15. The effect of low fluoride concentrations on microdamage accumulation in mouse tibias under impact loading

    NASA Astrophysics Data System (ADS)

    Luo, Qing; Chen, Nan; Zhou, Yan-Heng; Rong, Qi-Guo

    2015-12-01

    Microdamage accumulation in bone is one of the mechanisms for energy dissipation during the fracture process. Changes in the ultrastructure and composition of bone constituents due to aging or diseases could affect microdamage accumulation. Low concentration (1 mM) of sodium fluoride (NaF) has been used in this study to investigate the effect of ultrastructural changes on microdamage accumulation in mouse tibias following free-fall impact loadings. Twenty-two tibias were divided randomly into control and NaF-treated groups. Free-fall impact loading was conducted twice on each tibia to produce microdamage. The elastic modulus of NaF-treated tibias decreased significantly after the impact loadings, while there was no significant difference in the modulus of untreated samples between pre- and post-damage loadings. Microdamage morphology analysis showed that less and shorter microcracks existed in NaF-treated tibias compared with control bones. Meanwhile, more and longer microcracks were observed in tensile regions in untreated samples compared with that in compressive regions, whereas no significant difference was observed between tensile and compressive regions in NaF-treated bones. The results of this study indicate that more energy is required to generate microcracks in NaF-treated bone than in normal bone. A low concentration of fluoride treatment may increase the toughness of bone under impact loading.

  16. Selenium accumulation and selenium tolerance of salt grass from soils with elevated concentrations of Se and salinity

    SciTech Connect

    Wu, L.; Huang, Z.Z. )

    1991-12-01

    Biomass production, selenium accumulation, and the role of the bioextraction of selenium by salt grass (Distichlis spicata L.) in soils with elevated concentrations of Se and salinity at Kesterson, California, were studied. Salt grass contributed more than 80% vegetative coverage and 90% dry weight in the grassland communities where the soil Se concentrations were 100 times (1000 to 3000 micrograms kg-1) higher than the Se concentrations found in soils of the control sites. No evidence for evolution of Se tolerance was found in the salt grass populations. The successful colonization of salt grass in the soil with elevated Se and salinity is attributable to the presence of high concentrations of soil sulfate. Salt grass accumulated less Se than other salt-tolerant plant species existing in the same area, and no predation of animals and insects on salt grass has been noticed. Salt grass can transpire substantial amounts of volatile Se through its plant tissue. Under field conditions, a 1-m2 salt grass plot may produce 180 micrograms volatile selenium per day. However, no reduction of soil Se concentration in the salt grass habitat was detected over a period of 1 year. A long-term monitoring of Se status is needed in order to make predictions of the effectiveness of efforts to clean up Se-contaminated soils through the use of native plant species.

  17. Selenium accumulation and selenium tolerance of salt grass from soils with elevated concentrations of Se and salinity.

    PubMed

    Wu, L; Huang, Z Z

    1991-12-01

    Biomass production, selenium accumulation, and the role of the bioextraction of selenium by salt grass (Distichlis spicata L.) in soils with elevated concentrations of Se and salinity at Kesterson, California, were studied. Salt grass contributed more than 80% vegetative coverage and 90% dry weight in the grassland communities where the soil Se concentrations were 100 times (1000 to 3000 micrograms kg-1) higher than the Se concentrations found in soils of the control sites. No evidence for evolution of Se tolerance was found in the salt grass populations. The successful colonization of salt grass in the soil with elevated Se and salinity is attributable to the presence of high concentrations of soil sulfate. Salt grass accumulated less Se than other salt-tolerant plant species existing in the same area, and no predation of animals and insects on salt grass has been noticed. Salt grass can transpire substantial amounts of volatile Se through its plant tissue. Under field conditions, a 1-m2 salt grass plot may produce 180 micrograms volatile selenium per day. However, no reduction of soil Se concentration in the salt grass habitat was detected over a period of 1 year. A long-term monitoring of Se status is needed in order to make predictions of the effectiveness of efforts to clean up Se-contaminated soils through the use of native plant species. PMID:1778115

  18. Growth, carbon dioxide exchange and mineral accumulation in potatoes grown at different magnesium concentrations

    NASA Technical Reports Server (NTRS)

    Cao, W.; Tibbitts, T. W.

    1992-01-01

    Plants of Norland potatoes (Solanum tuberosum L.) were maintained for 42 days at Mg concentrations of 0.05, 0.125, 0.25, 1, 2, and 4 mM in a nonrecirculating nutrient film system under controlled environment. With the increased Mg supply from 0.05 to 4 mM, Mg concentrations in the leaves of the 42-day old plants increased significantly from 1.1 to 11.2 mg g-1 dry weight. Plant leaf area and plant and tuber dry weights increased with increased Mg concentrations up to 1 mM in solution or 6.7 mg g-1 in leaves, and then decreased with further increases in Mg concentrations. Rates of CO2 assimilation measured on leaflets in situ at ambient and various intercellular CO2 concentrations were consistently lower at 0.05 and 4 mM Mg than at other Mg treatments, which may indicate decreased photosynthetic activity in mesophyll tissues at the lowest and highest Mg concentrations. Dark respiration rates in leaves were highest at 0.05 and 4 mM Mg, lowest at 0.25 and 1 mM Mg, and intermediate at 0.125 and 2 mM Mg. The different Mg treatments also influenced accumulation of other minerals in leaves. Leaf concentrations of Ca and Mn decreased with increased Mg supply except that Ca and Mn were lower at 0.05 mM than at 0.125 mM Mg. Leaf K concentrations were lower at 1, 2 and 4 mM Mg than at other Mg treatments. Foliar concentrations of P, Fe, Zn, and Cu had small but inconsistent variation with different Mg concentrations. Leaf concentrations of N, S, and B were similar at different Mg concentrations. This study demonstrates that various Mg nutrition, along with altered accumulation of other nutrients, could regulate dry matter production in potatoes by affecting not only leaf area but also leaf carbon dioxide assimilation and respiration.

  19. Growth, carbon dioxide exchange and mineral accumulation in potatoes grown at different magnesium concentrations.

    PubMed

    Cao, W; Tibbitts, T W

    1992-01-01

    Plants of Norland potatoes (Solanum tuberosum L.) were maintained for 42 days at Mg concentrations of 0.05, 0.125, 0.25, 1, 2, and 4 mM in a nonrecirculating nutrient film system under controlled environment. With the increased Mg supply from 0.05 to 4 mM, Mg concentrations in the leaves of the 42-day old plants increased significantly from 1.1 to 11.2 mg g-1 dry weight. Plant leaf area and plant and tuber dry weights increased with increased Mg concentrations up to 1 mM in solution or 6.7 mg g-1 in leaves, and then decreased with further increases in Mg concentrations. Rates of CO2 assimilation measured on leaflets in situ at ambient and various intercellular CO2 concentrations were consistently lower at 0.05 and 4 mM Mg than at other Mg treatments, which may indicate decreased photosynthetic activity in mesophyll tissues at the lowest and highest Mg concentrations. Dark respiration rates in leaves were highest at 0.05 and 4 mM Mg, lowest at 0.25 and 1 mM Mg, and intermediate at 0.125 and 2 mM Mg. The different Mg treatments also influenced accumulation of other minerals in leaves. Leaf concentrations of Ca and Mn decreased with increased Mg supply except that Ca and Mn were lower at 0.05 mM than at 0.125 mM Mg. Leaf K concentrations were lower at 1, 2 and 4 mM Mg than at other Mg treatments. Foliar concentrations of P, Fe, Zn, and Cu had small but inconsistent variation with different Mg concentrations. Leaf concentrations of N, S, and B were similar at different Mg concentrations. This study demonstrates that various Mg nutrition, along with altered accumulation of other nutrients, could regulate dry matter production in potatoes by affecting not only leaf area but also leaf carbon dioxide assimilation and respiration. PMID:11537503

  20. Mechanisms and microbial structure of partial denitrification with high nitrite accumulation.

    PubMed

    Du, Rui; Peng, Yongzhen; Cao, Shenbin; Li, Baikun; Wang, Shuying; Niu, Meng

    2016-02-01

    Nitrite (NO2 (-)-N) accumulation in denitrification can provide the substrate for anammox, an efficient and cost-saving process for nitrogen removal from wastewater. This batch-mode study aimed at achieving high NO2 (-)-N accumulation over long-term operation with the acetate as sole organic carbon source and elucidating the mechanisms of NO2 (-)-N accumulation. The results showed that the specific nitrate (NO3 (-)-N) reduction rate (59.61 mg N VSS(-1) h(-1) at NO3 (-)-N of 20 mg/L) was much higher than specific NO2 (-)-N reduction rate (7.30 mg N VSS(-1) h(-1) at NO3 (-)-N of 20 mg/L), and the NO2 (-)-N accumulation proceeded well at the NO3 (-)-N to NO2 (-)-N transformation ratio (NTR) as high as 90 %. NO2 (-)-N accumulation was barely affected by the ratio of chemical oxygen demand (COD) to NO3 (-)-N concentration (C/N). With the addition of NO3 (-)-N, NO2 (-)-N accumulation occurred and the specific NO2 (-)-N reduction rate declined to a much lower level compared with the value in the absence of NO3 (-)-N. This indicated that the denitrifying bacteria in the system preferred to use NO3 (-)-N as electron acceptor rather than use NO2 (-)-N. In addition, the Illumina high-throughput sequencing analysis revealed that the genus of Thauera bacteria was dominant in the denitrifying community with high NO2 (-)-N accumulation and account for 67.25 % of total microorganism. This bacterium might be functional for high NO2 (-)-N accumulation in the presence of NO3 (-)-N. PMID:26526457

  1. Potassium concentration effect on growth, gas exchange and mineral accumulation in potatoes

    NASA Technical Reports Server (NTRS)

    Cao, W.; Tibbitts, T. W.

    1991-01-01

    This study was conducted to evaluate the responses of potatoes to six K solution concentrations maintained with a flow-through nutrient film system. Potato plants were grown for 42 days in sloping shallow trays containing a 1 cm layer of quartz gravel with a continuous flow of 4 ml min-1 of nutrient solutions having K concentrations of 0.10, 0.55, 1.59, 3.16, 6.44, 9.77 meq L-1. Plant leaf area, total and tuber dry weights were reduced over 25% at 0.10 meq L-1 of K and over 17% at 9.77 meq L-1 of K compared to concentrations of 0.55, 1.59, 3.16 and 6.44 meq L-1 of K. Gas exchange measurements on leaflets in situ after 39 days of growth demonstrated no significant differences among different K treatments in CO2 assimilation rate, stomatal conductance, intercellular CO2 concentration, and transpiration. Further measurements made only on plants grown at 0.10, 1.59, 6.44 meq L-1 of K showed similar responses of CO2 assimilation rate to different intercellular CO2 concentrations. This suggested that the photosynthetic systems were not affected by different K nutrition. The leaves of plants accumulated about 60% less K at 0.10 meq L-1 of K than at higher K concentrations. However, Ca and Mg levels in the leaves were higher at 0.10 meq L-1 of K than at higher K concentrations. This indicates that low K nutrition not only reduced plant growth, but also affected nutrient balance between major cations.

  2. Potassium concentration effect on growth, gas exchange and mineral accumulation in potatoes.

    PubMed

    Cao, W; Tibbitts, T W

    1991-01-01

    This study was conducted to evaluate the responses of potatoes to six K solution concentrations maintained with a flow-through nutrient film system. Potato plants were grown for 42 days in sloping shallow trays containing a 1 cm layer of quartz gravel with a continuous flow of 4 ml min-1 of nutrient solutions having K concentrations of 0.10, 0.55, 1.59, 3.16, 6.44, 9.77 meq L-1. Plant leaf area, total and tuber dry weights were reduced over 25% at 0.10 meq L-1 of K and over 17% at 9.77 meq L-1 of K compared to concentrations of 0.55, 1.59, 3.16 and 6.44 meq L-1 of K. Gas exchange measurements on leaflets in situ after 39 days of growth demonstrated no significant differences among different K treatments in CO2 assimilation rate, stomatal conductance, intercellular CO2 concentration, and transpiration. Further measurements made only on plants grown at 0.10, 1.59, 6.44 meq L-1 of K showed similar responses of CO2 assimilation rate to different intercellular CO2 concentrations. This suggested that the photosynthetic systems were not affected by different K nutrition. The leaves of plants accumulated about 60% less K at 0.10 meq L-1 of K than at higher K concentrations. However, Ca and Mg levels in the leaves were higher at 0.10 meq L-1 of K than at higher K concentrations. This indicates that low K nutrition not only reduced plant growth, but also affected nutrient balance between major cations. PMID:11538369

  3. Shallow Sediment Trace Metal Concentrations and Short-Term Accumulation Rates in the Neponset River Estuary, Massachusetts, USA

    NASA Astrophysics Data System (ADS)

    Spencer, J. R.; Zhu, J.; Olsen, C. R.

    2010-12-01

    The Neponset River estuary is a small estuary that drains into the Boston Harbor on the east coast of the United States. It is also a highly urbanized estuary and has a long history of urban development over 450 years. In July 2006, six sediment cores were collected in the Neponset River estuary to examine particle dynamics and sediment accumulation via radionuclide (Beryllium-7) dating, and to determine sediment metal concentrations (As, Cu, Pb, and Zn) via ED-XRF measurements. Measured sediment Be-7 profiles indicate various sedimentation environments, where sediment accumulation, resuspension or redeposition is likely to occur. High metal concentrations were often corresponding to high Be-7 inventories in sediment cores. Possible sources of trace metal contaminants in the water column include: storm water run-off, Combined Sewer Overflows (CSOs), a well-documented industrial pollution event that occurred upstream in the early to mid twentieth century, and the resuspension of sediment. Existing and future data will provide baseline information for quantifying the effects of the proposed and pending environmental restoration project, which includes the removal of the Baker Dam. The combined pre- and post-Dam removal data may then be used in cost-benefit analyses for other similar estuarine restoration projects.

  4. Vacuolar accumulation of heavy metals in Datura cultured cells is metal concentration dependent

    SciTech Connect

    Krotz, R.M.; Wagner, G.J.

    1987-04-01

    Vacuolar-extravacuolar compartmentation studies were performed to determine if the vacuole serves as an accumulation site for Cd, Zn, and Ni, after growth of Datura cultured cells in trace and high levels of these metals. After 3 to 4 days growth with 0.12 ..mu..M Cd or 0.02 ..mu..M Ni (radiolabeled) no evidence was obtained for vacuolar accumulation of these metals. In contrast, growth with 30 or 45 ..mu..M Cd, 11 ..mu..M Ni (with or without trace radiolabel), or 300 and 500 ..mu..M Zn resulted in isolated vacuoles which were enriched in metal. Compartmentation after exposure to low levels of Zn and also Cu is being investigated as is the subcellular site(s) of Cd-binding peptide formed during growth in high Cd. The hypothesis that Zn is accumulated as vacuolar organic acid salts is being tested directly because no evidence was found for formation of substantial ligand of Cd-peptide in response to Zn exposure.

  5. Nitrite accumulation performance of aerobic MBBR treating Lurgi coal gasification waste water by adjusting pollutant load and DO concentration.

    PubMed

    Li, Hui-Qiang; Han, Hong-Jun

    2015-01-01

    An aerobic moving bed biofilm reactor (MBBR) was adopted to treat Lurgi coal gasification waste water (LCGW) in about 10 months. The pollutant load and dissolve oxygen (DO) concentration were adjusted by trying to maximize the accumulation of [Formula: see text] in the MBBR for LCGW treatment. The highest [Formula: see text] accumulation proportion [Formula: see text] was 73.9%, but was not stable with influent chemical oxygen demand (COD) and DO concentrations of around 1000 and 1.5 mg/L, respectively. Around 1500 mg/L of influent COD concentration and 1.5 mg/L of DO concentration were proper operation conditions for the aerobic MBBR to achieve relatively stable [Formula: see text] accumulation, with [Formula: see text] ratio at 53% and [Formula: see text] ratio at just 4.3% in the effluent. More specifically, free ammonia concentration and DO concentration affected [Formula: see text] accumulation much more obvious than phenols concentration. The activity and quantity of nitrifying bacteria growth in suspended sludge and biofilm of the MBBR were monitored simultaneously to explain the variations of [Formula: see text] accumulation performance under different operation conditions. An aerobic moving bed biofilm reactor (MBBR) was adopted to treat Lurgi coal gasification waste water (LCGW)in about 10 months. The pollutant load and dissolve oxygen (DO) concentration were adjusted by trying to maximize the accumulation of NO(−)(2)−N in the MBBR for LCGW treatment. The highest NO(−)(2)−N accumulation proportion(NO(−)(2)−Neffluent/TN effluent) was 73.9%, but was not stable with influent chemical oxygen demand (COD) and DO concentrations of around 1000 and 1.5 mg/L, respectively. Around 1500 mg/L of influent COD concentration and 1.5 mg/L of DO concentration were proper operation conditions for the aerobic MBBR to achieve relatively stable NO(−)(2)−N accumulation,with NO(−)(2)−N/TN ratio at 53% and NO(-)(3)−N/TN ratio at just 4.3% in the

  6. Relationship of cadmium accumulation to zinc or copper concentration in horse liver and kidney

    SciTech Connect

    Koizumi, Naoko; Ninomiya, Ruriko; Fujita, Daisuke; Tsukamoto, Toshiyuki ); Inoue, Yoshiki )

    1989-06-01

    The concentrations of Cd, Zn, Cu, and metallothionein (MT) in the liver, renal cortex, and renal medulla were determined in 24 male and 15 female younger thoroughbreds (age 27 to 97 months) and two old male horses (age 154 months and 190 months). High correlations were found between Zn and MT in the liver, between Cd and MT in the renal cortex, and between Cd and Zn in the renal cortex, while the correlation between Cd and MT in the liver was low. In the renal medulla, high correlations were found between Cd and Zn, between Zn and Cu, and between Cd and Cu. Therefore, in the liver, the MT concentration is the most highly correlated with the Zn concentration and is not correlated with the Cd concentration unless artificially exposed to Cd. In the renal cortex, the MT and Cd concentrations are very highly correlated with each other. The Zn concentration is about 20 {mu}/g when the Cd concentration in the renal cortex is the lowest.

  7. Design and development of a high-concentration photovoltaic concentrator

    SciTech Connect

    Hodge, R C

    1982-04-01

    The design and development of a high concentration photovoltaic concentrator module is discussed. The design concept described herein incorporates a curved groove domed Fresnel lens, a high concentration etched multiple vertical junction (EMVJ) solar cell and a passively cooled direct-bonded copper cell mount all packaged in a plastic module. Two seven inch diameter 1200x domed Fresnel lenses were fabricated using single point diamond turning technology. Testing at both GE and Sandia confirmed optical transmission efficiencies of over 83%. Samples of the latest available EMVJ cells were mounted and installed, with a domed Fresnel lens, into a prototype module. Subsequent testing demonstrated net lens-cell efficiencies of 10 to 13%. As a result of this program, salient conclusions have been formulated as to this technology.

  8. Alveolar accumulation/concentration of nitrogen during apneic oxygenation with arteriovenous carbon dioxide removal.

    PubMed

    Nielsen, Niels D; Andersen, Gratien; Kjaergaard, Benedict; Staerkind, Mette E; Larsson, Anders

    2010-01-01

    In a model of acute lung injury (ALI), previously, we have shown that apneic oxygenation, using an inspiratory O2 fraction (FiO2) of 1.0 combined with extracorporeal arteriovenous CO2 removal (AO-AVCR) maintains adequate arterial O2 and CO2 levels for a prolonged period. However, it is important that FiO2 lower than 1.0 can be used to avoid possible pulmonary oxygen toxicity. In preliminary studies, arterial oxygenation decreased to extreme low levels, when FiO2 <1 was used in apneic oxygenation. We assumed that this was caused either by alveolar accumulation/concentration of N2 or by absorption atelectasis. In four anesthetized and mechanically ventilated pigs, mild lung injury was induced. After a lung recruitment maneuver, we initiated two 20-minute periods of AO-AVCR with FiO2 of 1 and 0.5, respectively. By using FiO2 = 1, PaO2 remained above 300 mm Hg. At the end of the period, the alveolar O2 fraction (FAO2) was 0.89 (0.88-0.89; median and ranges). With FiO2 = 0.5, PaO2 decreased 90% compared with baseline values and FAO2 decreased to 0.07 (0.06-0.07). No atelectasis was visible on computed tomography after either period, and we, therefore, conclude that the alveolar hypoxia was caused by the alveolar N2 accumulation/concentration and subsequently by the O2 depletion. PMID:20038832

  9. Dual Mode NOx Sensor: Measuring Both the Accumulated Amount and Instantaneous Level at Low Concentrations

    PubMed Central

    Groß, Andrea; Beulertz, Gregor; Marr, Isabella; Kubinski, David J.; Visser, Jaco H.; Moos, Ralf

    2012-01-01

    The accumulating-type (or integrating-type) NOx sensor principle offers two operation modes to measure low levels of NOx: The direct signal gives the total amount dosed over a time interval and its derivative the instantaneous concentration. With a linear sensor response, no baseline drift, and both response times and recovery times in the range of the gas exchange time of the test bench (5 to 7 s), the integrating sensor is well suited to reliably detect low levels of NOx. Experimental results are presented demonstrating the sensor’s integrating properties for the total amount detection and its sensitivity to both NO and to NO2. We also show the correlation between the derivative of the sensor signal and the known gas concentration. The long-term detection of NOx in the sub-ppm range (e.g., for air quality measurements) is discussed. Additionally, a self-adaption of the measurement range taking advantage of the temperature dependency of the sensitivity is addressed. PMID:22736980

  10. The HSP terminator of Arabidopsis thaliana induces a high level of miraculin accumulation in transgenic tomatoes.

    PubMed

    Hirai, Tadayoshi; Kurokawa, Natsuko; Duhita, Narendra; Hiwasa-Tanase, Kyoko; Kato, Kazuhisa; Kato, Ko; Ezura, Hiroshi

    2011-09-28

    High-level accumulation of the target recombinant protein is a significant issue in heterologous protein expression using transgenic plants. Miraculin, a taste-modifying protein, was accumulated in transgenic tomatoes using an expression cassette in which the miraculin gene was expressed by the cauliflower mosaic virus (CaMV) 35S promoter and the heat shock protein (HSP) terminator (MIR-HSP). The HSP terminator was derived from heat shock protein 18.2 in Arabidopsis thaliana . Using this HSP-containing cassette, the miraculin concentration in T0 transgenic tomato lines was 1.4-13.9% of the total soluble protein (TSP), and that in the T1 transgenic tomato line homozygous for the miraculin gene reached 17.1% of the TSP. The accumulation level of the target protein was comparable to levels observed with chloroplast transformation. The high-level accumulation of miraculin in T0 transgenic tomato lines achieved by the HSP terminator was maintained in the successive T1 generation, demonstrating the genetic stability of this accumulation system. PMID:21861502

  11. Lipid accumulation and growth characteristics of Chlorella zofingiensis under different nitrate and phosphate concentrations.

    PubMed

    Feng, Pingzhong; Deng, Zhongyang; Fan, Lu; Hu, Zhengyu

    2012-10-01

    To evaluate the potential of the green agla Chlorella zofingiensis as a feedstock for biodiesel production, the effects of nitrogen and phosphate on lipid accumulation and growth of C. zofingiensis were studied. The maximum specific growth rate (μ(max)) reached 2.15 day⁻¹ when the concentration of NaNO₃ and K₂HPO₄·3H₂O was 1.0 g L⁻¹ and 0.01 g L⁻¹, respectively. The lipid contents of C. zofingiensis grown in media deficient of nitrogen (65.1%) or phosphate (44.7%) were both higher than that obtained from cells grown in full medium (33.5%). The highest lipid productivity (87.1 mg L⁻¹ day⁻¹) was also obtained from cells grown in nitrogen deficient media, indicating nitrogen deficiency was more effective than phosphate deficiency for inducing lipid accumulation in C. zofingiensis. In addition, the feasibility of cultivating the alga in 60 L flat plate photobioreactors and 10 L bottles outdoors for biodiesel was also tested. It was found that C. zofingiensis could adapt to fluctuating temperatures and irradiance of outdoors and the highest μ(max) and lipid productivity could reach 0.362 day⁻¹ and 26.6 mg L⁻¹ day⁻¹ outdoors, respectively. The lipid production potential of C. zofingiensis is projected to be 31.1 kg ha⁻¹ day⁻¹ in outdoor culture. These results suggested that C. zofingiensis is a promising organism for feedstock production of biofuel and can be used in scaled up culture outdoors. PMID:22698727

  12. Modelling anaerobic digestion of concentrated black water and faecal matter in accumulation system.

    PubMed

    Elmitwalli, Tarek; Zeeman, Grietje; Otterpohl, Ralf

    2011-01-01

    A dynamic mathematical model based on anaerobic digestion model no. 1 (ADM1) was developed for accumulation (AC) system treating concentrated black water and faecal matter at different temperatures. The AC system was investigated for the treatment of waste (water) produced from the following systems: vacuum toilet for black water (VBW), vacuum toilet for faeces with urine separation (VF), dry toilet (DT), dry toilets for faeces with urine separation (DF), separated faecal matter from conventional black water by filter bag (FB). For evaluation of the AC system treating the proposed waste (water) sources at 20 and 35 degrees C, two options were studied: (1) The filling period of the AC system was constant for all waste (water) sources (either 1, 3 or 6 months) and for each period, the seed sludge volume was varied; (2) The volume of the AC system was constant for all proposed waste (water) sources. The results showed that the filling period of the AC system was the main parameter affecting the system performance, followed by operational temperature, while the increase of the seed sludge volume slightly enhanced the performance of the system. The model results indicated that the filling period of the AC system should be higher than 150 days for obtaining a stable performance. It was found that the hydrolysis of biodegradable particulate chemical oxygen demand (COD) is the rate limiting step, as volatile fatty acid concentration is very low in all experimental conditions (< 200 mgCOD/L at 20 degrees C and < 100 mgCOD/L at 35 degrees C). Based on the results of the two options, it was found that the concentrated waste (water) sources have better performance than the diluted waste (water) sources, like VBW waste (water). Furthermore, smaller volume will be required for the AC system. PMID:21902047

  13. Highly concentrated foam formulation for blast mitigation

    DOEpatents

    Tucker, Mark D.; Gao, Huizhen

    2010-12-14

    A highly concentrated foam formulation for blast suppression and dispersion mitigation for use in responding to a terrorism incident involving a radiological dispersion device. The foam formulation is more concentrated and more stable than the current blast suppression foam (AFC-380), which reduces the logistics burden on the user.

  14. Different palm oil preparations reduce plasma cholesterol concentrations and aortic cholesterol accumulation compared to coconut oil in hypercholesterolemic hamsters.

    PubMed

    Wilson, Thomas A; Nicolosi, Robert J; Kotyla, Timothy; Sundram, Kalyana; Kritchevsky, David

    2005-10-01

    Several studies have reported on the effect of refined, bleached and deodorized palm oil (RBD-PO) incorporation into the diet on blood cholesterol concentrations and on the development of atherosclerosis. However, very little work has been reported on the influence of red palm oil (RPO), which is higher in carotenoid and tocopherol content than RBD-PO. Thus, we studied the influence of RPO, RBD-PO and a RBD-PO plus red palm oil extract (reconstituted RBD-PO) on plasma cholesterol concentrations and aortic accumulation vs. hamsters fed coconut oil. Forty-eight F1B Golden Syrian hamsters (Mesocricetus auratus) (BioBreeders, Watertown, MA) were group housed (three/cage) in hanging polystyrene cages with bedding in an air-conditioned facility maintained on a 12-h light/dark cycle. The hamsters were fed a chow-based hypercholesterolemic diet (HCD) containing 10% coconut oil and 0.1% cholesterol for 2 weeks at which time they were bled after an overnight fast and segregated into four groups of 12 with similar plasma cholesterol concentrations. Group 1 continued on the HCD, Group 2 was fed the HCD containing 10% RPO in place of coconut oil, Group 3 was fed the HCD containing 10% RBD-PO in place of coconut oil and Group 4 was fed the HCD with 10% reconstituted RBD-PO for an additional 10 weeks. Plasma total cholesterol (TC) and non-high-density lipoprotein-cholesterol (HDL-C) (very low- and low-density lipoprotein) concentrations were significantly lower in the hamsters fed the RPO (-42% and -48%), RBD-PO (-32% and -36%) and the reconstituted RBD-PO (-37% and -41%) compared to the coconut oil-fed hamsters. Plasma HDL-C concentrations were significantly higher by 14% and 31% in hamsters fed the RBD-PO and RPO compared to the coconut oil-fed hamsters. Plasma triglyceride (TG) concentrations were significantly lower in hamsters fed RBD-PO (-32%) and the reconstituted RBD-PO (-31%) compared to the coconut oil-fed hamsters. The plasma gamma-tocopherol concentrations were higher

  15. Copper uptake by Eichhornia crassipes exposed at high level concentrations.

    PubMed

    Melignani, Eliana; de Cabo, Laura Isabel; Faggi, Ana María

    2015-06-01

    The objective of this study was to assess the growth of water hyacinth (Eichhornia crassipes) and its ability to accumulate Cu from polluted water with high Cu concentrations and a mixture of other contaminants under short-term exposure, in order to use this species for the remediation of highly contaminated sites. Two hydroponic experiments were performed under greenhouse conditions for 7 days. One of them consisted of growing water hyacinth in Hoagland solution supplemented with 15 or 25 mg Cu/L and a control. The other one contained water hyacinth growing in polluted river water supplemented with 15 mg Cu/L and a control. Cu was accumulated principally in roots. The maximum Cu concentration was 23,387.2 mg/kg dw in the treatment of 25 mg Cu/L in Hoagland solution. Cu translocation from roots to leaves was low. The mixture of 15 mg Cu/L with polluted water did not appear to have toxic effects on the water hyacinth. This plant showed a remarkable uptake capacity under elevated Cu concentrations in a mixture of pollutants similar to pure industrial effluents in a short time of exposure. This result has not been reported before, to our knowledge. This species is suitable for phytoremediation of waters subject to discharge of mixed industrial effluents containing elevated Cu concentrations (≥15 mg Cu/L), as well as nutrient-rich domestic wastewaters. PMID:25529492

  16. Different responses of low grain-Cd-accumulating and high grain-Cd-accumulating rice cultivars to Cd stress.

    PubMed

    Wang, Feijuan; Wang, Min; Liu, Zhouping; Shi, Yan; Han, Tiqian; Ye, Yaoyao; Gong, Ning; Sun, Junwei; Zhu, Cheng

    2015-11-01

    Cadmium (Cd) is a major heavy metal pollutant which is highly toxic to plants and animals. The accumulation of Cd in rice grains is a major agricultural problem in regions with Cd pollution. A hydroponics experiment using low grain-Cd-accumulating rice (xiushui 11) and high grain-Cd-accumulating rice (xiushui 110) was carried out to characterize the different responses of rice cultivars to Cd stress. We found that xiushui 11 was more tolerant to Cd than xiushui 110, and xiushui 11 suffered less oxidative damage. Cell walls played an important role in limiting the amount of Cd that entered the protoplast, especially in xiushui 11. Cd stored in organelles as soluble fractions, leading to greater physiological stress of Cd detoxification. We found that Cd can disturb the ion homeostasis in rice roots because Cd(2+) and Ca(2+) may have a similar uptake route. Xiushui 11 had a faster root-to-shoot transport of Cd, and the expression level of OsPCR1 gene which was predicted related with Cd accumulation in rice was consist with the Cd transport of root-to-shoot in rice and maintain the greater Cd tolerance of xiushui 11. These results suggest there are different Cd detoxification and accumulation mechanisms in rice cultivars. PMID:26318143

  17. TISSUE-SPECIFIC DIFFERENCES IN ACCUMULATION OF STRESS PROTEINS IN MYTILUS EDULIS EXPOSED TO A RANGE OF COPPER CONCENTRATIONS

    EPA Science Inventory

    This study examines the expression and accumulation of two major stress proteins, stress70 and chaperonin60 (cpn60), in the gill and mantle of blue mussels, Mytilus edulis, which were exposed to a range of Cu concentrations for 7 days. cope-for-growth (SFG), mortality, and Cu acc...

  18. ELEVATED CO2 AND ELEVATED TEMPERATURE AFFECT CARBON AND NITROGEN CONCENTRATIONS BUT NOT ACCUMULATION IN PSEUDOTSUGA MENZIESII SEEDLINGS

    EPA Science Inventory

    To determine the impact of climate change on concentrations and accumulation of C and N in trees, we grew Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir) seedlings treated with ambient or elevated (+180 mol mol-1) CO2, and with ambient or elevated (+3.5 C) temperature for f...

  19. Organic and inorganic amendments affect soil concentration and accumulation of cadmium and lead in wheat in calcareous alkaline soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation with untreated effluent in periurban agriculture could result in accumulation and bioconcentrations of cadmium (Cd) and lead (Pb). Different amendments were used to investigate their effect on availability, concentration, and uptake of metals by wheat in texturally different soils. Crop w...

  20. High-stage analog accumulator for TDI CMOS image sensors

    NASA Astrophysics Data System (ADS)

    Jianxin, Li; Fujun, Huang; Yong, Zong; Jing, Gao

    2016-02-01

    The impact of the parasitic phenomenon on the performance of the analog accumulator in TDI CMOS image sensor is analyzed and resolved. A 128-stage optimized accumulator based on 0.18-μm one-poly four-metal 3.3 V CMOS technology is designed and simulated. A charge injection effect from the top plate sampling is employed to compensate the un-eliminated parasitics based on the accumulator with a decoupling switch, and then a calibration circuit is designed to restrain the mismatch and Process, Voltage and Temperature (PVT) variations. The post layout simulation indicates that the improved SNR of the accumulator upgrades from 17.835 to 21.067 dB, while an ideal value is 21.072 dB. In addition, the linearity of the accumulator is 99.62%. The simulation results of two extreme cases and Monte Carlo show that the mismatch and PVT variations are restrained by the calibration circuit. Furthermore, it is promising to design a higher stage accumulator based on the proposed structure. Project supported by the National Natural Science Foundation of China (Nos. 61404090, 61434004).

  1. Tolerance of Ricinus communis L. to Cd and screening of high Cd accumulation varieties for remediation of Cd contaminated soils.

    PubMed

    Wu, Shanshan; Shen, Chuang; Yang, Zhongyi; Lin, Biyun; Yuan, Jiangang

    2016-11-01

    Response of castor (Ricinus communis L.) to cadmium (Cd) was assessed by a seed-suspending seedbed approach. Length of total radicle was the most sensitive indicator of Cd tolerance among the tested germination and growth characters. The ED50 value for Cd was 11.87 mg L(-1), indicating high Cd tolerance in castor. A pot experiment was conducted by growing 46 varieties of castor under CK (without Cd) and Cd1 (10 mg kg(-1) of Cd) and Cd2 (50 mg kg(-1) of Cd) treatments to investigate genotype variations in growth response and Cd accumulation of castor under different Cd exposures. Castor possessed high Cd accumulation ability; average shoot and root Cd concentrations of the 46 tested varieties were 21.83 and 185.43 mg kg(-1), and 174.99 and 1181.96 mg kg(-1) under Cd1 and Cd2, respectively. Great variation in Cd accumulation was observed among varieties, and Cd concentration of castor was genotype dependent. The correlation between biomass and Cd accumulation was significantly positive, while no significant correlation was observed between Cd concentration and Cd accumulation, which indicated that biomass performance is the dominant factor in determining Cd accumulation ability. PMID:27348198

  2. The association of very high hair manganese accumulation and high oxidative stress in Mongolian people.

    PubMed

    Komatsu, Fumio; Kagawa, Yasuo; Ishiguro, Kiyomi; Kawabata, Terue; Purvee, Baatar; Otgon, Jugder; Chimedregzen, Ulziiburen

    2009-03-01

    Oxidative stress induces several diseases and early aging. Previously, we reported that Mongolians are exposed in high oxidative stress, which may cause their early aging. In this study, to know the reason of high oxidative stress, we measured hair metals. This investigation was performed in Murun city, in the northern area of this country, and 469 healthy subjects, ranging from 10 to 82 years of age, were randomly enrolled. Oxidative stress was evaluated by the levels of serum reactive oxygen metabolites (ROM), malondialdehyde-modified low-density lipoprotein (MDA-LDL) and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG). Antioxidant capacity (AOC) was estimated by the levels of biological antioxidant potential (BAP) and superoxide dismutase (SOD) activity. Scalp hair metals were measured using an inductively coupled plasma mass spectrometry method. Murun subjects showed high ROM levels of 394+/-75 Carr U (n=342), compared with Japanese healthy subjects (n=356, 326+/-51 Carr U, p<0.001). MDA-LDL and 8-OHdG levels also showed high levels. While, BAP levels of Murun subjects were 2263+/-203 micromol/L (n=210), Japanese subjects (n=356, 2087+/-215 micromol/L, p<0.001). SOD activities were also high, suggesting that the high oxidative may accelerate the state of AOC. Murun subjects demonstrated high accumulation of several metals in the hairs. In particular, Mn accumulation exhibited from 2 fold to 40 fold increases of Japanese standard. These findings are indicative that the high Mn accumulation may contribute to the high oxidative stress. The mechanism of its high accumulation was not explained by food materials or drinking water. We should further investigate another influence such as sandy wind. In order to suppress the high oxidative stress, elimination of the high Mn accumulation should be urgently studied. PMID:20021397

  3. High efficiency compound semiconductor concentrator photovoltaics

    NASA Technical Reports Server (NTRS)

    Borden, P.; Gregory, P.; Saxena, R.; Owen, R.; Moore, O.

    1980-01-01

    Special emphasis was given to the high yield pilot production of packaged AlGaAs/GaAs concentrator solar cells, using organometallic VPE for materials growth, the demonstration of a concentrator module using 12 of these cells which achieved 16.4 percent conversion efficiency at 50 C coolant inlet temperature, and the demonstration of a spectral splitting converter module that achieved in excess of 20 percent efficiency. This converter employed ten silicon and ten AlGaAs cells with a dichroic filter functioning as the beam splitter. A monolithic array of AlGaAs/GaAs solar cells is described.

  4. Effect of high glucose concentrations on human erythrocytes in vitro

    PubMed Central

    Viskupicova, Jana; Blaskovic, Dusan; Galiniak, Sabina; Soszyński, Mirosław; Bartosz, Grzegorz; Horakova, Lubica; Sadowska-Bartosz, Izabela

    2015-01-01

    Exposure to high glucose concentrations in vitro is often employed as a model for understanding erythrocyte modifications in diabetes. However, effects of such experiments may be affected by glucose consumption during prolonged incubation and changes of cellular parameters conditioned by impaired energy balance. The aim of this study was to compare alterations in various red cell parameters in this type of experiment to differentiate between those affected by glycoxidation and those affected by energy imbalance. Erythrocytes were incubated with 5, 45 or 100 mM glucose for up to 72 h. High glucose concentrations intensified lipid peroxidation and loss of activities of erythrocyte enzymes (glutathione S-transferase and glutathione reductase). On the other hand, hemolysis, eryptosis, calcium accumulation, loss of glutathione and increase in the GSSG/GSH ratio were attenuated by high glucose apparently due to maintenance of energy supply to the cells. Loss of plasma membrane Ca2+-ATPase activity and decrease in superoxide production were not affected by glucose concentration, being seemingly determined by processes independent of both glycoxidation and energy depletion. These results point to the necessity of careful interpretation of data obtained in experiments, in which erythrocytes are subject to treatment with high glucose concentrations in vitro. PMID:26141922

  5. Differences in the accumulated metal concentrations in two epigeic earthworm species (Lumbricus rubellus and Dendrodrilus rubidus) living in contaminated soils

    SciTech Connect

    Morgan, J.E.; Morgan, A.J. )

    1991-08-01

    Lumbricus rubellus and Denrodrilus rubidus are acid-tolerant epigeic species, which are often the only species inhabiting the poorly vegetated and heavily contaminated soils associated with many abandoned mine sites. Although both species probably consume similar food materials, observations on worms collected from acidic and calcareous mine sites indicate that they accumulate significantly different metal concentrations in their tissues: the larger L. rubellus accumulates more Zn and Ca, but less Pb and Cd than D. rubidus. The aim of the present study was to analyze these two epigeic species sampled from ten diverse sites to determine whether the inter-species differences in relative metal accumulation is a general feature of these sympatrics.

  6. Inhibitory effect of mineral ion accumulation on high density growth of the hyperthermophilic archaeon Sulfolobus solfataricus.

    PubMed

    Park, C B; Lee, S B

    1999-01-01

    A fed-batch operation for high density cultivation of Sulfolobus solfataricus (DSM 1617) in a bench-top fermentor using a feed medium composed of glucose and yeast extract was investigated. The highest maximal cell density obtained in controlled fed-batch cultures was 21.7 g/l. Although higher yeast extract concentrations in the medium favored greater cell biomass yield, cell growth ceased with low cell densities. It was observed that large amounts of inorganic ions, such as sulfate, ammonium, potassium and phosphate ions, were accumulated in the culture broth at higher yeast extract concentrations. This was due to either the addition of the titrant or feeding of yeast extract during cultivation. Fed-batch cultures with additional mineral salts in the feed medium showed much lower cell biomass, indicating that accumulation of inorganic ions has a significant inhibitory effect on the growth of S. solfataricus. Inhibition of cell growth by the presence of mineral ions was further confirmed by the batch culture experiments. Some plausible mechanisms which can account for the growth inhibition at higher mineral ion concentrations have been suggested. PMID:16232474

  7. High Concentration Suspensions Under Strong Tidal Flows

    NASA Astrophysics Data System (ADS)

    Kineke, G. C.; Milligan, T. G.; Heath, K. M.; Law, B. A.

    2006-12-01

    An experiment investigating the influence of high-concentration suspensions of fine sediments (fluid muds) on a quasi-steady flow was carried out in the Petitcodiac River, Moncton, New Brunswick, Canada in August 2006. Concurrent measurements of fluid properties (salinity, temperature, density), suspended-sediment concentration, current velocity and shear were made throughout the water column over portions of several tidal cycles. The Petitcodiac was chosen because of consistently high suspended-sediment concentrations (0.5- >200 g/L) and large tidal range (>4 m) producing strong current velocities (> 1.5 m/s). Thus the Peticodiac serves as an ideal natural flume for examining the behavior of muddy suspensions under both accelerating and decelerating flows. Instrumentation included a profiling package with paired electromagnetic current meters mounted 0.6 m apart, a CTD, and an Optical Backscatterance Sensor with a pump system for in situ calibrations. Approximately 1.5 hours after the passage of the tidal bore and a fully mixed turbulent flow, the water column begins to stratify and a high concentration bottom layer forms persisting through the ensuing ebb. Measured suspended-sediment concentrations reached 286 g/L at the bottom and low shear rates of 0.13 s-1 in the upper water column increased to ~0.5 s-1 through the lutocline 1 m above the bed, and decreased to approximately 0 within the fluid mud. Analysis is in progress and the data set provides an excellent means to test threshold conditions regarding suppression of turbulence by sediment-induced stratification and the carrying capacity of turbulent flows.

  8. The Effects of Inorganic Nitrogen form and CO2 Concentration on Wheat Yield and Nutrient Accumulation and Distribution

    PubMed Central

    Carlisle, Eli; Myers, Samuel; Raboy, Victor; Bloom, Arnold

    2012-01-01

    Inorganic N is available to plants from the soil as ammonium (NH4+) and nitrate (NO3-). We studied how wheat grown hydroponically to senescence in controlled environmental chambers is affected by N form (NH4+ vs. NO3−) and CO2 concentration (“subambient,” “ambient,” and “elevated”) in terms of biomass, yield, and nutrient accumulation and partitioning. Wheat supplied with NH4+ as a sole N source had the strongest response to CO2 concentration. Plants exposed to subambient and ambient CO2 concentrations typically had the greatest biomass and nutrient accumulation under both N forms. In general NH4+-supplied plants had higher concentrations of total N, P, K, S, Ca, Zn, Fe, and Cu, while NO3--supplied plants had higher concentrations of Mg, B, Mn, and NO3- - N. NH4+-supplied plants contained amounts of phytate similar to NO3−-supplied plants but had higher bioavailable Zn, which could have consequences for human health. NH4+-supplied plants allocated more nutrients and biomass to aboveground tissues whereas NO3+-supplied plants allocated more nutrients to the roots. The two inorganic nitrogen forms influenced plant growth and nutrient status so distinctly that they should be treated as separate nutrients. Moreover, plant growth and nutrient status varied in a non-linear manner with atmospheric CO2 concentration. PMID:22969784

  9. Metal dynamics and tolerance of Typha domingensis exposed to high concentrations of Cr, Ni and Zn.

    PubMed

    Mufarrege, M M; Hadad, H R; Di Luca, G A; Maine, M A

    2014-07-01

    Typha domingensis was exposed to a 100mgL(-1) Cr+100mgL(-1) Ni+100mgL(-1) Zn solution. Metal tolerance and metal accumulation in plant tissues and sediment were studied over time. Although removal rates were different, the three metals were efficiently removed from water. Leaf and root tissues showed high metal concentration. However, the sediment showed the highest accumulation. During the first hours of contact, metals were not only accumulated by sediment and roots but they were also taken up by the leaves in direct contact with the solution. Over time, metals were translocated from roots to leaves and vice versa. Metals caused growth inhibition and a decrease in chlorophyll concentration and affected anatomical parameters. Despite these sub-lethal effects, T. domingensis demonstrated that it could accumulate Cr, Ni and Zn efficiently and survive an accidental dump of high concentrations of contaminants in systems such as natural and constructed wetlands. PMID:24793518

  10. Image analysis of bioparticles accumulation and diamagnetic alignment in high-gradient magnetic field.

    PubMed

    Norina, Svetlana B; Park, Sang-Hyun; Kim, Jungdae; Cho, Sungil; Shalygin, A N; Soh, Kwang-Sup

    2005-01-01

    Magnetic properties of biological particles are measured in high-gradient magnetic separation (HGMS) analysis, revealing the concentrating process of nucleoprotein particles, ferritin, red blood cells, and eggs. A magnetic force acting on micrometer and submicrometer biological particles having diamagnetic or paramagnetic susceptibility with respect to the solution causes their movement and accumulation in gradient magnetic fields dependent on the values of the magnetic moments. The methods developed enable us to obtain the magnetic moments values of single particles and their assembly directly from magnetic separation and image analyses without assuming the detection of sizes. Our precision methods for the measurement of the capture traveling (magnetic diffusion) time and the accumulation (magnetic sedimentation) radius in HGMS show that it is really possible to determine the weak dia- or paramagnetic shifts of magnetic susceptibility up to 0.7x10(-10) (SI units). HGMS analysis of the concentrating process of nucleoprotein granules (microcells, DNA granules, or nucleosome core particles) with polarization microscopy reveals phase transitions for DNA in granules, and separation accumulation of particles enables the determination of the diamagnetic susceptibility and anisotropy properties. Magnetic concentration effects always occur in living systems because micrometer-located gradient magnetic fields inside an organism are strong enough to cause drifts of cellular complexes and organelles of micrometer and submicrometer sizes. We report the appearance of superparamagnetic contamination inside developing shrimp eggs. In the developing shrimps eggs, ferritin aggregates are observed under weak gradient magnetic fields and diaparaferromagnetic changes are detected. A significant interruption of egg development is revealed in such fields. PMID:16292954

  11. Accumulation of radionuclides by fish in relation to presence of bottom deposits and concentration of microelements in the water

    SciTech Connect

    Katkov, A.E.

    1980-03-01

    This paper is devoted to determination of the special features of accumulation of hydrobionts of radionuclides desorbed from the bottom in comparison with the accumulation of radionuclides entering the water directly. The investigations were stimulated by published information indicating that bottom deposits can shield bottom bionts against the uptake of some radionuclides and that the uptake of radionuclides by plants is enhanced by the presence of bottom deposits. We also sum up the results of experimental investigations of concentration factors (CF) for nuclides in relation to their concentration in water to obtain a more accurate picture of the role of mineralization in the exchange of microelements. The experiments were conducted on adult (6 to 8 years old) goldfish (Carassius carassius) from a body of water containing fresh water with a total mineral content of 0.06 g/liter.

  12. DOE High Performance Concentrator PV Project

    SciTech Connect

    McConnell, R.; Symko-Davies, M.

    2005-08-01

    Much in demand are next-generation photovoltaic (PV) technologies that can be used economically to make a large-scale impact on world electricity production. The U.S. Department of Energy (DOE) initiated the High-Performance Photovoltaic (HiPerf PV) Project to substantially increase the viability of PV for cost-competitive applications so that PV can contribute significantly to both our energy supply and environment. To accomplish such results, the National Center for Photovoltaics (NCPV) directs in-house and subcontracted research in high-performance polycrystalline thin-film and multijunction concentrator devices with the goal of enabling progress of high-efficiency technologies toward commercial-prototype products. We will describe the details of the subcontractor and in-house progress in exploring and accelerating pathways of III-V multijunction concentrator solar cells and systems toward their long-term goals. By 2020, we anticipate that this project will have demonstrated 33% system efficiency and a system price of $1.00/Wp for concentrator PV systems using III-V multijunction solar cells with efficiencies over 41%.

  13. Microbial life at high salt concentrations: phylogenetic and metabolic diversity

    PubMed Central

    Oren, Aharon

    2008-01-01

    Halophiles are found in all three domains of life. Within the Bacteria we know halophiles within the phyla Cyanobacteria, Proteobacteria, Firmicutes, Actinobacteria, Spirochaetes, and Bacteroidetes. Within the Archaea the most salt-requiring microorganisms are found in the class Halobacteria. Halobacterium and most of its relatives require over 100–150 g/l salt for growth and structural stability. Also within the order Methanococci we encounter halophilic species. Halophiles and non-halophilic relatives are often found together in the phylogenetic tree, and many genera, families and orders have representatives with greatly different salt requirement and tolerance. A few phylogenetically coherent groups consist of halophiles only: the order Halobacteriales, family Halobacteriaceae (Euryarchaeota) and the anaerobic fermentative bacteria of the order Halanaerobiales (Firmicutes). The family Halomonadaceae (Gammaproteobacteria) almost exclusively contains halophiles. Halophilic microorganisms use two strategies to balance their cytoplasm osmotically with their medium. The first involves accumulation of molar concentrations of KCl. This strategy requires adaptation of the intracellular enzymatic machinery, as proteins should maintain their proper conformation and activity at near-saturating salt concentrations. The proteome of such organisms is highly acidic, and most proteins denature when suspended in low salt. Such microorganisms generally cannot survive in low salt media. The second strategy is to exclude salt from the cytoplasm and to synthesize and/or accumulate organic 'compatible' solutes that do not interfere with enzymatic activity. Few adaptations of the cells' proteome are needed, and organisms using the 'organic-solutes-in strategy' often adapt to a surprisingly broad salt concentration range. Most halophilic Bacteria, but also the halophilic methanogenic Archaea use such organic solutes. A variety of such solutes are known, including glycine betaine

  14. Microbial life at high salt concentrations: phylogenetic and metabolic diversity.

    PubMed

    Oren, Aharon

    2008-01-01

    Halophiles are found in all three domains of life. Within the Bacteria we know halophiles within the phyla Cyanobacteria, Proteobacteria, Firmicutes, Actinobacteria, Spirochaetes, and Bacteroidetes. Within the Archaea the most salt-requiring microorganisms are found in the class Halobacteria. Halobacterium and most of its relatives require over 100-150 g/l salt for growth and structural stability. Also within the order Methanococci we encounter halophilic species. Halophiles and non-halophilic relatives are often found together in the phylogenetic tree, and many genera, families and orders have representatives with greatly different salt requirement and tolerance. A few phylogenetically coherent groups consist of halophiles only: the order Halobacteriales, family Halobacteriaceae (Euryarchaeota) and the anaerobic fermentative bacteria of the order Halanaerobiales (Firmicutes). The family Halomonadaceae (Gammaproteobacteria) almost exclusively contains halophiles. Halophilic microorganisms use two strategies to balance their cytoplasm osmotically with their medium. The first involves accumulation of molar concentrations of KCl. This strategy requires adaptation of the intracellular enzymatic machinery, as proteins should maintain their proper conformation and activity at near-saturating salt concentrations. The proteome of such organisms is highly acidic, and most proteins denature when suspended in low salt. Such microorganisms generally cannot survive in low salt media. The second strategy is to exclude salt from the cytoplasm and to synthesize and/or accumulate organic 'compatible' solutes that do not interfere with enzymatic activity. Few adaptations of the cells' proteome are needed, and organisms using the 'organic-solutes-in strategy' often adapt to a surprisingly broad salt concentration range. Most halophilic Bacteria, but also the halophilic methanogenic Archaea use such organic solutes. A variety of such solutes are known, including glycine betaine

  15. High-efficiency silicon concentrator cell commercialization

    SciTech Connect

    Sinton, R.A.; Swanson, R.M.

    1993-05-01

    This report summarizes the first phase of a forty-one month program to develop a commercial, high-efficiency concentrator solar cell and facility for manufacturing it. The period covered is November 1, 1990 to December 31, 1991. This is a joint program between the Electric Power Research Institute (EPRI) and Sandia National Laboratories. (This report is also published by EPRI as EPRI report number TR-102035.) During the first year of the program, SunPower accomplished the following major objectives: (1) a new solar cell fabrication facility, which is called the Cell Pilot Line (CPL), (2) a baseline concentrator cell process has been developed, and (3) a cell testing facility has been completed. Initial cell efficiencies are about 23% for the baseline process. The long-range goal is to improve this efficiency to 27%.

  16. Thin photovoltaic modules at ultra high concentration

    NASA Astrophysics Data System (ADS)

    Pérez-Higueras, Pedro; Ferrer-Rodríguez, Juan Pablo; Shanks, Katie; Almonacid, Florencia; Férnández, Eduardo F.

    2015-09-01

    A new design concept of high concentration photovoltaic (HCPV) module is studied both by ray-tracing simulation and by building a prototype. This set-up is based on the idea of concentrating sunlight from different optical units to a single commercial multi-junction solar cell, which is located in a different plane than that of the primary optics (e.g. Fresnel lenses). A two-optical-unit set-up, as a first approach, is built and measured with the solar simulator "Helios 3198". These results are compared to the measurement results of the single-unit of one Fresnel lens and the same solar cell. The feasibility of this new design has been confirmed theoretically and practically.

  17. Distribution of the concentration of heavy metals associated with the sediment particles accumulated on road surfaces.

    PubMed

    Zafra, C A; Temprano, J; Tejero, I

    2011-07-01

    The heavy metal pollution caused by road run-off water constitutes a problem in urban areas. The metallic load associated with road sediment must be determined in order to study its impact in drainage systems and receiving waters, and to perfect the design of prevention systems. This paper presents data regarding the sediment collected on road surfaces in the city of Torrelavega (northern Spain) during a period of 65 days (132 samples). Two sample types were collected: vacuum-dried samples and those swept up following vacuuming. The sediment loading (g m(-2)), particle size distribution (63-2800 microm) and heavy metal concentrations were determined. The data showed that the concentration of heavy metals tends to increase with the reduction in the particle diameter (exponential tendency). The concentrations ofPb, Zn, Cu, Cr, Ni, Cd, Fe, Mn and Co in the size fraction <63 microm were 350, 630, 124, 57, 56, 38, 3231, 374 and 51 mg kg(-1), respectively (average traffic density: 3800 vehicles day(-1)). By increasing the residence time of the sediment, the concentration increases, whereas the ratio of the concentration between the different size fractions decreases. The concentration across the road diminishes when the distance between the roadway and the sampling siteincreases; when the distance increases, the ratio between size fractions for heavy metal concentrations increases. Finally, the main sources of heavy metals are the particles detached by braking (brake pads) and tyre wear (rubber), and are associated with particle sizes <125 microm. PMID:21882553

  18. Changes of concentrations and possibility of accumulation of bisphenol A and alkylphenols, depending on biomass and composition, in zooplankton of the Southern Baltic (Gulf of Gdansk).

    PubMed

    Staniszewska, Marta; Nehring, Iga; Mudrak-Cegiołka, Stella

    2016-06-01

    The focus of the present study was to find the relationship between concentrations of bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP) in zooplankton and seasonal changes in the composition and biomass of particular zooplankton taxa in the Gulf of Gdansk (Southern Baltic) in the years 2011-2012. Assays of BPA, OP and NP in water and zooplankton samples were performed using the HPLC/FL system. High mean concentrations of the studied compounds, determined in spring (405.9 (BPA); 25.7 (OP); 111.2 (NP) ng g(-1) dw), can be linked to the high proportion of meroplankton in that season. Rotifera also had an influence on the rise in concentrations of the studied compounds but to a lesser degree, while the lowest concentrations (determined in summer) can be associated with the high participation of Copepoda and Cladocera in zooplankton biomass. It was also observed that juvenile forms can be more susceptible to accumulating endocrine disrupting compounds (EDCs). This is indicated by the positive correlation between BPA concentration in zooplankton and the proportion of Copepoda nauplii biomass in spring (r = 0.90; p < 0.05). In most cases, greater zooplankton biomass accumulated higher concentrations and loads of the studied compounds. With biomass growth (to 123.32 μg m(-3)), the bioconcentration factor also rose (to max 46.1·10(3)), demonstrating that unlike typical hydrophobic compounds the studied EDCs do not become "diluted" in zooplankton biomass. The highest BPA concentrations from all compounds may be connected with anthropogenic sources located in the coastal zone. PMID:26970874

  19. Ammonia Solubility in High Concentration Salt Solutions

    SciTech Connect

    HEDENGREN, D.C.

    2000-02-01

    Solubility data for ammonia in water and various dilute solutions are abundant in the literature. However, there is a noticeable lack of ammonia solubility data for high salt, basic solutions of various mixtures of salts including those found in many of the Hanford Washington underground waste tanks. As a result, models based on solubility data for dilute salt solutions have been used to extrapolate to high salt solutions. These significant extrapolations need to be checked against actual laboratory data. Some indirect vapor measurements have been made. A more direct approach is to determine the ratio of solubility of ammonia in water to its solubility in high salt solutions. In various experiments, pairs of solutions, one of which is water and the other a high salt solution, are allowed to come to equilibrium with a common ammonia vapor pressure. The ratio of concentrations of ammonia in the two solutions is equal to the ratio of the respective ammonia solubilities (Henry's Law constants) at a given temperature. This information can then be used to refine the models that predict vapor space compositions of ammonia. Ammonia at Hanford is of concern because of its toxicity in the environment and its contribution to the flammability of vapor space gas mixtures in waste tanks.

  20. Diverse microbial species survive high ammonia concentrations

    NASA Astrophysics Data System (ADS)

    Kelly, Laura C.; Cockell, Charles S.; Summers, Stephen

    2012-04-01

    Planetary protection regulations are in place to control the contamination of planets and moons with terrestrial micro-organisms in order to avoid jeopardizing future scientific investigations relating to the search for life. One environmental chemical factor of relevance in extraterrestrial environments, specifically in the moons of the outer solar system, is ammonia (NH3). Ammonia is known to be highly toxic to micro-organisms and may disrupt proton motive force, interfere with cellular redox reactions or cause an increase of cell pH. To test the survival potential of terrestrial micro-organisms exposed to such cold, ammonia-rich environments, and to judge whether current planetary protection regulations are sufficient, soil samples were exposed to concentrations of NH3 from 5 to 35% (v/v) at -80°C and room temperature for periods up to 11 months. Following exposure to 35% NH3, diverse spore-forming taxa survived, including representatives of the Firmicutes (Bacillus, Sporosarcina, Viridibacillus, Paenibacillus, Staphylococcus and Brevibacillus) and Actinobacteria (Streptomyces). Non-spore forming organisms also survived, including Proteobacteria (Pseudomonas) and Actinobacteria (Arthrobacter) that are known to have environmentally resistant resting states. Clostridium spp. were isolated from the exposed soil under anaerobic culture. High NH3 was shown to cause a reduction in viability of spores over time, but spore morphology was not visibly altered. In addition to its implications for planetary protection, these data show that a large number of bacteria, potentially including spore-forming pathogens, but also environmentally resistant non-spore-formers, can survive high ammonia concentrations.

  1. High glucose levels reduce fatty acid oxidation and increase triglyceride accumulation in human placenta.

    PubMed

    Visiedo, Francisco; Bugatto, Fernando; Sánchez, Viviana; Cózar-Castellano, Irene; Bartha, Jose L; Perdomo, Germán

    2013-07-15

    Placentas of women with gestational diabetes mellitus (GDM) exhibit an altered lipid metabolism. The mechanism by which GDM is linked to alterations in placental lipid metabolism remains obscure. We hypothesized that high glucose levels reduce mitochondrial fatty acid oxidation (FAO) and increase triglyceride accumulation in human placenta. To test this hypothesis, we measured FAO, fatty acid esterification, de novo fatty acid synthesis, triglyceride levels, and carnitine palmitoyltransferase activities (CPT) in placental explants of women with GDM or no pregnancy complication. In women with GDM, FAO was reduced by ~30% without change in mitochondrial content, and triglyceride content was threefold higher than in the control group. Likewise, in placental explants of women with no complications, high glucose levels reduced FAO by ~20%, and esterification increased linearly with increasing fatty acid concentrations. However, de novo fatty acid synthesis remained unchanged between high and low glucose levels. In addition, high glucose levels increased triglyceride content approximately twofold compared with low glucose levels. Furthermore, etomoxir-mediated inhibition of FAO enhanced esterification capacity by ~40% and elevated triglyceride content 1.5-fold in placental explants of women, with no complications. Finally, high glucose levels reduced CPT I activity by ~70% and phosphorylation levels of acetyl-CoA carboxylase by ~25% in placental explants of women, with no complications. We reveal an unrecognized regulatory mechanism on placental fatty acid metabolism by which high glucose levels reduce mitochondrial FAO through inhibition of CPT I, shifting flux of fatty acids away from oxidation toward the esterification pathway, leading to accumulation of placental triglycerides. PMID:23673156

  2. Acute systemic accumulation of acrolein in mice by inhalation at a concentration similar to that in cigarette smoke

    PubMed Central

    Tully, Melissa; Zheng, Lingxing; Acosta, Glen; Tian, Ran; Shi, Riyi

    2015-01-01

    Cigarette smoke is an important environmental factor associated with a wide array of public health concerns. Acrolein, a component of tobacco smoke and a known toxin to various cell types, may be a key pathological factor mediating the adverse effects linked with tobacco smoke. Although acrolein is known to accumulate in the respiratory system after acute nasal exposure, it is not clear if it accumulates systemically, and less is known in the nervous system. The aim of this study was to assess the degree of acrolein accumulation in the circulation and in the spinal cord following acute acrolein inhalation in mice. Using a laboratory-fabricated inhalation chamber, we found elevated urinary 3-HPMA, an acrolein metabolite, and increased acrolein adducts in the spinal cord after weeks of nasal exposure to acrolein at a concentration similar to that in tobacco smoke. The data indicated that acrolein is absorbed into the circulatory system and some enters the nervous system. It is expected that these findings may facilitate further studies to probe the pathological role of acrolein in the nervous system resulting from smoke and other external sources. PMID:25446876

  3. Highly accumulative production of L(+)-lactate from glucose by crystallization fermentation with immobilized Rhizopus oryzae.

    PubMed

    Yamane, Tsuneo; Tanaka, Ryohsuke

    2013-01-01

    In order to produce microbiologically large amount of l(+)-lactic acid (LA) from glucose, batch and fed-batch (intermittent addition of sterilized glucose powder aseptically) cultures of Rhizopus oryzae NBRC 5384 (identical to NRRL 395 and ATCC 9363) whose mycelia were immobilized in situ within sponge-like cubic particles (3.5 mm edge long) were carried out at 37°C in a three baffled shake flask. Appropriately calculated amount of fine powdery calcium carbonate (CaCO(3)) was added initially or intermittently to control pH of the culture liquids. High accumulations of LA (145 g/L and 231 g/L, in reality 176 g/L and 280 g/L as anhydrous calcium lactate) were achieved by a batch (glucose concentration = 150 g/L) and a fed-batch cultures (the initial glucose concentration = 150 g/L and the intermittent addition of glucose equivalent to 100 g/L). In these cultures the yields and productivities of LA were, 95.0%, 1.42 g/L·h and 92.5%, 1.83 g/L·h, respectively. Existence of considerable amounts of calcium lactate (Ca(LA)(2)) as crystals in the culture broth was experimentally proved by two evidences: (i) heating up (70°C) followed by quick low centrifugal force to remove remaining CaCO(3) solids from culture broth and then cooling down (37°C) followed by incubation of the culture supernatant at 37°C to observe recrystallization of Ca(LA)(2), and (ii) the measurement of solubility of Ca(LA)(2) in the culture media. It was conceptually discussed to be able to avoid the product inhibition by means of crystallization fermentation for the high accumulation of LA by R. oryzae. PMID:22938823

  4. Effects of lead concentration and accumulation on the performance and microbial community of aerobic granular sludge in sequencing batch reactors.

    PubMed

    Tan, Guangcai; Xu, Nan; Liu, Yong; Hao, Hongshan; Sun, Weiling

    2016-11-01

    The present study investigated the effects of lead on the morphological structure, physical and chemical properties, wastewater treatment performance and microbial community structure of aerobic granular sludge (AGS) in sequencing batch reactors (SBRs). The results showed that at Pb(2+) concentration of 1 mg/L, the mixed liquid suspended solids decreased, the settling velocity increased and the sludge volume index increased sharply. Meanwhile, AGS began to disintegrate and show an irregular shape. In terms of wastewater treatment in an SBR, the phosphorus removal rate was affected only until the Pb(2+) concentration was up to 1 mg/L. The [Formula: see text] removal efficiency began to decline when the Pb(2+) concentration increased to 6 mg/L, while the removal of chemical oxygen demand increased slightly within the Pb(2+) concentration range of 1-6 mg/L. Significant changes were observed in the microbial community structure, especially the dominant bacteria. Compared to the Pb(2+) accumulation on the sludge, the Pb(2+) concentration in the aqueous phase played a more important role in the performance and microbial community of AGS in SBRs. PMID:27012589

  5. Physical chemistry of highly concentrated emulsions.

    PubMed

    Foudazi, Reza; Qavi, Sahar; Masalova, Irina; Malkin, Alexander Ya

    2015-06-01

    This review explores the physics underlying the rheology of highly concentrated emulsions (HCEs) to determine the relationship between elasticity and HCE stability, and to consider whether it is possible to describe all physicochemical properties of HCEs on the basis of a unique physical approach. We define HCEs as emulsions with a volume fraction above the maximum closest packing fraction of monodisperse spheres, φm=0.74, even if droplets are not of polyhedron shape. The solid-like rheological behavior of HCEs is characterized by yield stress and elasticity, properties which depend on droplet polydispersity and which are affected by caging at volume fractions about the jamming concentration, φj. A bimodal size distribution in HCEs diminishes caging and facilitates droplet movement, resulting in HCEs with negligible yield stress and no plateau in storage modulus. Thermodynamic forces automatically move HCEs toward the lowest free energy state, but since interdroplet forces create local minimums - points beyond which free energy temporarily increases before it reaches the global minimum of the system - the free energy of HCEs will settle at a local minimum unless additional energy is added. Several attempts have been undertaken to predict the elasticity of HCEs. In many cases, the elastic modulus of HCEs is higher than the one predicted from classical models, which only take into account spatial repulsion (or simply interfacial energy). Improved models based on free energy calculation should be developed to consider the disjoining pressure and interfacial rheology in addition to spatial repulsion. The disjoining pressure and interfacial viscoelasticity, which result in the deviation of elasticity from the classical model, can be regarded as parameters for quantifying the stability of HCEs. PMID:25869114

  6. Copepods in Turbid Shallow Soda Lakes Accumulate Unexpected High Levels of Carotenoids

    PubMed Central

    Schneider, Tobias; Herzig, Alois; Koinig, Karin A.; Sommaruga, Ruben

    2012-01-01

    Carotenoids are protective pigments present in many aquatic organisms that reduce the photooxidative stress induced by short-wavelenght solar radiation, yet increase their susceptibility to predators. Arctodiaptomus spinosus, a calanoid copepod typically found in many fishless shallow soda lakes, shows large between-lake differences in pigmentation. Here, we attribute these differences to the environmental state of these ecosystems, namely, ‘dark water’ lakes with submersed vegetation and turbid ‘white’ lakes lacking macrophytes. Copepod carotenoid concentration in the turbid ‘white’ lakes was significantly (about 20-fold) higher than in the ‘dark water’ ones, although the latter systems were characterized by higher transparency. In addition, males had on a dry weight basis around three times higher carotenoid concentrations than females. Mycosporine-like amino acids (direct UV screening substances) were found in all cases, but in low concentration. The environmental conditions in these ecosystems were largely shaped by the presence/absence of submersed macrophytes Thus, in the turbid lakes, the strong wind-driven mixis allows for copepods to be brought to the surface and being exposed to solar radiation, whereas in ‘dark water’ ones, macrophytes reduce water turbulence and additionally provide shelter. Our results explain the counter-intuitive notion of strong red pigmentation in copepods from a turbid ecosystem and suggest that factors other than high UV transparency favor carotenoid accumulation in zooplankton. PMID:22916208

  7. Mineral accumulation by perennial grasses in a high rainfall environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Straw produced as a co-product of perennial ryegrass (Lolium perenne L.), orchardgrass (Dactylis glomerata), tall fescue (Schedonorus phoenix (Scop.) Holub), and Kentucky bluegrass (Poa pratensis L.) seed production in the high rainfall area of western Oregon as well as clippings from urban and recr...

  8. Haematological and biochemical parameters and tissue accumulations of cadmium in Oreochromis niloticus exposed to various concentrations of cadmium chloride

    PubMed Central

    Al-Asgah, Nasser A.; Abdel-Warith, Abdel-Wahab A.; Younis, El-Sayed M.; Allam, Hassan Y.

    2015-01-01

    Oreochromis niloticus, weighing 36.45 ± 1.12 g were exposed to 10%, 20% and 30% of the LC50 of CdCl2 which represents treatments (T1)1.68, (T2)3.36 and (T3)5.03 mg/l, respectively, for a period of 10, 20 and 30 days. It was found that, compared to a control group reading of 0.19 ± 0.03 μg/g dry weight, accumulation of Cd in the gills was significantly (p < 0.05) increased in samples ranging between 7.64 ± 0.86 and 61.73 ± 0.82 μg/g dry weight from T1 at 10 days to T3 at 30 days. The accumulation of Cd in the liver, meanwhile, was also observed to significantly increase (p < 0.05) with increasing time and concentrations with results ranging between 3.21 ± 0.12 and 181.61 ± 1.32 compared to the control group results of 0.29 ± 0.04 μg/g dry weight. Although muscles exhibited lower levels of accumulation than the gills and liver they still showed the same pattern of increase compared to the control group, with a significant difference ranging between 0.32 ± 0.02 and 2.16 ± 0.08 compared to the control group results of 0.03 ± 0.001 μg/g dry weight. Also, haematological parameters such as red blood cells (RBCs), haemoglobin (Hb) and haematocrit (Hct) were reduced in fish exposed to Cd at all periods, with significant differences (p < 0.05). Plasma glucose concentration showed a significant increase. Total protein levels of fish showed a significant reduction (p > 0.05) for all exposed treatments. Also, the total lipid level increased significantly as fish were exposed to increasing cadmium concentrations, compared to control fish. Finally, the activities of aspartate aminotransferase (AST IU/l) and alanine aminotransferase (ALT IU/l) showed a significant increase (p < 0.05) with increasing time and concentrations. PMID:26288556

  9. High-efficiency concentrator silicon solar cells

    SciTech Connect

    Sinton, R.A.; Cuevas, A.; King, R.R.; Swanson, R.M. . Solid-State Electronics Lab.)

    1990-11-01

    This report presents results from extensive process development in high-efficiency Si solar cells. An advanced design for a 1.56-cm{sup 2} cell with front grids achieved 26% efficiency at 90 suns. This is especially significant since this cell does not require a prismatic cover glass. New designs for simplified backside-contact solar cells were advanced from a status of near-nonfunctionality to demonstrated 21--22% for one-sun cells in sizes up to 37.5 cm{sup 2}. An efficiency of 26% was achieved for similar 0.64-cm{sup 2} concentrator cells at 150 suns. More fundamental work on dopant-diffused regions is also presented here. The recombination vs. various process and physical parameters was studied in detail for boron and phosphorous diffusions. Emitter-design studies based solidly upon these new data indicate the performance vs design parameters for a variety of the cases of most interest to solar cell designers. Extractions of p-type bandgap narrowing and the surface recombination for p- and n-type regions from these studies have a generality that extends beyond solar cells into basic device modeling. 68 refs., 50 figs.

  10. Effects of arsenic species and concentrations on arsenic accumulation by different fern species in a hydroponic system.

    PubMed

    Fayiga, A O; Ma, L Q; Santos, Jorge; Rathinasabapathi, B; Stamps, B; Littell, R C

    2005-01-01

    Two hydroponic experiments were conducted to evaluate factors affecting plant arsenic (As) hyperaccumulation. In the first experiment; two As hyperaccumulators (Pteris vittata and P. cretica mayii) were exposed to 1 and 10 mg L(-1) arsenite (AsIII) and monomethyl arsenic acid (MMA) for 4 wk. Total As concentrations in plants (fronds and roots) and solution were determined In the second experiment P. vittata and Nephrolepis exaltata (a non-As hyperaccumulator) were exposed to 5 mgL(-1) arsenate (AsV) and 20 mgL(-1) AsIIIfor 1 and 15 d. Total As and AsIII concentrations in plants were determined Compared to P. cretica mayii, P. vittata was more efficient in arsenic accumulation (1075-1666 vs. 249-627mg kg(-1) As in the fronds) partially because it is more efficient in As translocation. As translocation factor (As concentration ratio in fronds to roots) was 3.0-5.6 for P. vittata compared to 0.1 to 4.8 for P. cretica. Compared to N. exaltata, P. vittata was significantly more efficient in arsenic accumulation (38-542 vs. 4.8-71 mg kg(-1) As in thefronds) as well asAs translocation (1.3-5.6 vs. 0.2-0.5). In addition, P. vittata was much more efficient in As reduction from AsV to AsIII (83-84 vs. 13-24% AsIII in the fronds). Little As reduction occurred after 1-d exposure to AsV in both species indicates that As reduction was not instantaneous even in an As hyperaccumulator. Our data were consistent with the hypothesis that both As translocation and As reduction are important for plant As hyperaccumulation. PMID:16285413

  11. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

  12. Molecular basis of high viscosity in concentrated antibody solutions: Strategies for high concentration drug product development.

    PubMed

    Tomar, Dheeraj S; Kumar, Sandeep; Singh, Satish K; Goswami, Sumit; Li, Li

    2016-01-01

    Effective translation of breakthrough discoveries into innovative products in the clinic requires proactive mitigation or elimination of several drug development challenges. These challenges can vary depending upon the type of drug molecule. In the case of therapeutic antibody candidates, a commonly encountered challenge is high viscosity of the concentrated antibody solutions. Concentration-dependent viscosity behaviors of mAbs and other biologic entities may depend on pairwise and higher-order intermolecular interactions, non-native aggregation, and concentration-dependent fluctuations of various antibody regions. This article reviews our current understanding of molecular origins of viscosity behaviors of antibody solutions. We discuss general strategies and guidelines to select low viscosity candidates or optimize lead candidates for lower viscosity at early drug discovery stages. Moreover, strategies for formulation optimization and excipient design are also presented for candidates already in advanced product development stages. Potential future directions for research in this field are also explored. PMID:26736022

  13. Horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications.

    PubMed

    Ma, Hongcai; Wu, Lin

    2015-07-10

    We present the design of a horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications. This solar concentrator consists of an array of telecentric primary concentrators, a horizontally staggered lightguide layer, and a vertically tapered lightguide layer. The primary concentrator is realized by two plano-aspheric lenses with lateral movement and maintains a high F-number over an angle range of ±23.5°. The results of the simulations show that the solar concentrator achieves a high concentration ratio of 500× with ±0.5° of acceptance angle by a single-axis tracker and dual lateral translation stages. PMID:26193396

  14. Elevated rates of organic carbon, nitrogen, and phosphorus accumulation in a highly impacted mangrove wetland

    NASA Astrophysics Data System (ADS)

    Sanders, Christian J.; Eyre, Bradley D.; Santos, Isaac R.; Machado, Wilson; Luiz-Silva, Wanilson; Smoak, Joseph M.; Breithaupt, Joshua L.; Ketterer, Michael E.; Sanders, Luciana; Marotta, Humberto; Silva-Filho, Emmanoel

    2014-04-01

    The effect of nutrient enrichment on mangrove sediment accretion and carbon accumulation rates is poorly understood. Here we quantify sediment accretion through radionuclide tracers to determine organic carbon (OC), total nitrogen (TN), and total phosphorus (TP) accumulation rates during the previous 60 years in both a nutrient-enriched and a pristine mangrove forest within the same geomorphological region of southeastern Brazil. The forest receiving high nutrient loads has accumulated OC, TN, and TP at rates that are fourfold, twofold, and eightfold respectively, higher than those from the undisturbed mangrove. Organic carbon and TN stable isotopes (δ13C and δ15N) reflect an increased presence of organic matter (OM) originating with either phytoplankton, benthic algae, or another allochthonous source within the more rapidly accumulated sediments of the impacted mangrove. This suggests that the accumulation rate of OM in eutrophic mangrove systems may be enhanced through the addition of autochthonous and allochthonous nonmangrove material.

  15. Co-digestion of concentrated black water and kitchen refuse in an accumulation system within the DESAR (decentralized sanitation and reuse) concept.

    PubMed

    Kujawa-Roeleveld, K; Elmitwalli, T; Gaillard, A; van Leeuwen, M; Zeeman, G

    2003-01-01

    Co-digestion of concentrated black water and kitchen refuse within the DESAR concept was the objective of this pilot research. The digestion took place in two, non-mixed accumulation reactors (AC1 and AC2) inoculated with digested primary sludge from a WWTP at a temperature of 20 degrees C for a period of around 150 days. Reactor AC1 was fed with a mixture of faeces, urine and kitchen refuse in the equivalent amount that one individual generates per day. The AC2 was fed with a mixture of faeces and kitchen refuse in the equivalent amount that two individuals produce per day. Some contribution of urine to AC2 was not to be avoided. Detailed characterisation of waste(water) was performed. The performance of the stratified reactor was followed by monitoring the reactor content for several reactors' heights as well as being based on the biogas production. In general the system exposed good process stability. The methanisation of 34 and 61% was obtained for AC1 and AC2 respectively. The biogas yield was 26.5 and 50.8 L/p/d for the respective reactors. Proper choice of inoculum as well as good buffering capacity did not lead to accumulation of VFA and an inhibitive effect due to relatively high ammonium concentration. The chosen process is a promising technology showing good process stability especially for high strength influent. PMID:14531430

  16. HIGH INTENSITY EFFECTS IN THE SNS ACCUMULATOR RING

    SciTech Connect

    Holmes, Jeffrey A; Cousineau, Sarah M; Danilov, Viatcheslav; Plum, Michael A; Shishlo, Andrei P

    2008-01-01

    Currently operating at 0.5 MW beam power on target, the Spallation Neutron Source (SNS) is already the world's most powerful pulsed neutron source. However, we are only one third of the way to full power. As we ramp toward full power, the control of the beam and beam loss in the ring will be critical. In addition to practical considerations, such as choice of operating point, painting scheme, RF bunching, and beam scattering, it may be necessary to understand and mitigate collective effects due to space charge, impedances, and electron clouds. At each stage of the power ramp-up, we use all available resources to understand and to minimize beam losses. From the standpoint of beam dynamics, the losses observed so far under normal operating conditions have not involved collective phenomena. We are now entering the intensity regime in which this may change. In dedicated high intensity beam studies, we have already observed resistive wall, extraction kicker impedance-driven, and electron cloud activities. The analysis and simulation of this data are important ongoing activities at SNS. This paper discusses the status of this work, as well as other considerations necessary to the successful full power operation of SNS.

  17. Biological denitrification of high concentration nitrate waste

    DOEpatents

    Francis, Chester W.; Brinkley, Frank S.

    1977-01-01

    Biological denitrification of nitrate solutions at concentrations of greater than one kilogram nitrate per cubic meter is accomplished anaerobically in an upflow column having as a packing material a support for denitrifying bacteria.

  18. High hydrostatic pressure leads to free radicals accumulation in yeast cells triggering oxidative stress.

    PubMed

    Bravim, Fernanda; Mota, Mainã M; Fernandes, A Alberto R; Fernandes, Patricia M B

    2016-08-01

    Saccharomyces cerevisiae is a unicellular organism that during the fermentative process is exposed to a variable environment; hence, resistance to multiple stress conditions is a desirable trait. The stress caused by high hydrostatic pressure (HHP) in S. cerevisiae resembles the injuries generated by other industrial stresses. In this study, it was confirmed that gene expression pattern in response to HHP displays an oxidative stress response profile which is expanded upon hydrostatic pressure release. Actually, reactive oxygen species (ROS) concentration level increased in yeast cells exposed to HHP treatment and an incubation period at room pressure led to a decrease in intracellular ROS concentration. On the other hand, ethylic, thermic and osmotic stresses did not result in any ROS accumulation in yeast cells. Microarray analysis revealed an upregulation of genes related to methionine metabolism, appearing to be a specific cellular response to HHP, and not related to other stresses, such as heat and osmotic stresses. Next, we investigated whether enhanced oxidative stress tolerance leads to enhanced tolerance to HHP stress. Overexpression of STF2 is known to enhance tolerance to oxidative stress and we show that it also leads to enhanced tolerance to HHP stress. PMID:27388472

  19. Dissecting the molecular basis of the contribution of source strength to high fructan accumulation in wheat.

    PubMed

    Xue, Gang-Ping; Drenth, Janneke; Glassop, Donna; Kooiker, Maarten; McIntyre, C Lynne

    2013-01-01

    Fructans represent the major component of water soluble carbohydrates (WSCs) in the maturing stem of temperate cereals and are an important temporary carbon reserve for grain filling. To investigate the importance of source carbon availability in fructan accumulation and its molecular basis, we performed comparative analyses of WSC components and the expression profiles of genes involved in major carbohydrate metabolism and photosynthesis in the flag leaves of recombinant inbred lines from wheat cultivars Seri M82 and Babax (SB lines). High sucrose levels in the mature flag leaf (source organ) were found to be positively associated with WSC and fructan concentrations in both the leaf and stem of SB lines in several field trials. Analysis of Affymetrix expression array data revealed that high leaf sucrose lines grown in abiotic-stress-prone environments had high expression levels of a number of genes in the leaf involved in the sucrose synthetic pathway and photosynthesis, such as Calvin cycle genes, antioxidant genes involved in chloroplast H(2)O(2) removal and genes involved in energy dissipation. The expression of the majority of genes involved in fructan and starch synthetic pathways were positively correlated with sucrose levels in the leaves of SB lines. The high level of leaf fructans in high leaf sucrose lines is likely attributed to the elevated expression levels of fructan synthetic enzymes, as the mRNA levels of three fructosyltransferase families were consistently correlated with leaf sucrose levels among SB lines. These data suggest that high source strength is one of the important genetic factors determining high levels of WSC in wheat. PMID:23114999

  20. Concentration-dependent effects and intracellular accumulation of HIV protease inhibitors in cultured CD4 T cells and primary human lymphocytes

    PubMed Central

    Janneh, Omar; Bray, Patrick G.; Jones, Elizabeth; Wyen, Christoph; Chiba, Peter; Back, David J.; Khoo, Saye H.

    2010-01-01

    Background The intracellular and plasma concentrations of HIV protease inhibitors (HPIs) vary widely in vivo. It is unclear whether there is a concentration-dependent effect of HPIs such that at increasing concentration they may either block their own efflux (leading to ‘autoboosting’) or influx (leading to saturability/decreased intracellular accumulation). Method The effects of various concentrations (0–30 µM) of lopinavir, saquinavir, ritonavir and atazanavir on the accumulation of [14C]lopinavir, [3H]saquinavir, [3H]ritonavir and [3H]atazanavir, respectively, were investigated in CEMparental, CEMVBL [P-glycoprotein (ABCB1) overexpressing], CEME1000 (MRP1 overexpressing) and in peripheral blood mononuclear cells (PBMCs). We also investigated the effects of inhibitors of ABCB1/ABCG2 (tariquidar), ABCC (MK571) and ABCC1/2 (frusemide), singly and in combination with HPIs, on cellular accumulation. Results In all the cell lines, with increasing concentration of lopinavir, saquinavir and ritonavir, there was a significant increase in the cellular accumulation of [14C]lopinavir, [3H]saquinavir and [3H]ritonavir. Tariquidar, MK571 and frusemide (alone and in combination with lopinavir, saquinavir and ritonavir) significantly increased the accumulation of [14C]lopinavir, [3H]saquinavir and [3H]ritonavir. Ritonavir (alone or in combination with tariquidar) decreased the intracellular accumulation of [3H]ritonavir in PBMCs. Atazanavir decreased the accumulation of [3H]atazanavir in a concentration-dependent manner in all of the cells tested. Conclusions There are complex and variable drug-specific rather than class-specific effects of the HPIs on their own accumulation. PMID:20237075

  1. [Concentrations of mercury in ambient air in wastewater irrigated area of Tianjin City and its accumulation in leafy vegetables].

    PubMed

    Zheng, Shun-An; Han, Yun-Lei; Zheng, Xiang-Qun

    2014-11-01

    limit of mercury in food. Spinach appeared to accumulate more mercury than the other four vegetables, in which the median and mean mercury content were both higher than 20 μg x kg(-1). The mercury concentrations in rape, lettuce and allium tuberosum were lower than the standard. Moreover, test results indicated that the Hg content in leafy vegetables was mainly the gaseous mercury through leaf adsorption but not the Hg particulates. This study clearly manifested that there should be a great concern on the pollution risk of both air-and soil borne mercury when cultivating leafy vegetables in long-term wastewater-irrigated area. PMID:25639114

  2. Culturable associated-bacteria of the sponge Theonella swinhoei show tolerance to high arsenic concentrations

    PubMed Central

    Keren, Ray; Lavy, Adi; Mayzel, Boaz; Ilan, Micha

    2015-01-01

    Sponges are potent filter feeders and as such are exposed to high fluxes of toxic trace elements, which can accumulate in their body over time. Such is the case of the Red Sea sponge Theonella swinhoei, which has been shown to accumulate up to 8500 mg/Kg of the highly toxicelement arsenic. T. swinhoei is known to harbor a multitude of sponge-associated bacteria, so it is hypothesized that the associated-bacteria will be tolerant to high arsenic concentration. This study also investigates the fate of the arsenic accumulated in the sponge to test if the associated-bacteria have an important role in the arsenic accumulation process of their host, since bacteria are key players in the natural arsenic cycle. Separation of the sponge to sponge cells and bacteria enriched fractions showed that arsenic is accumulated by the bacteria. Sponge-associated, arsenic-tolerant bacteria were cultured in the presence of 5 mM of either arsenate or arsenite (equivalent to 6150 mg/Kg arsenic, dry weight). The 54 isolated bacteria were grouped to 15 operational taxonomic units (OTUs) and isolates belonging to 12 OTUs were assessed for tolerance to arsenate at increased concentrations up to 100 mM. Eight of the 12 OTUs tolerated an order of magnitude increase in the concentration of arsenate, and some exhibited external biomineralization of arsenic–magnesium salts. The biomineralization of this unique mineral was directly observed in bacteria for the first time. These results may provide an explanation for the ability of the sponge to accumulate considerable amounts of arsenic. Furthermore arsenic-mineralizing bacteria can potentially be used for the study of bioremediation, as arsenic toxicity affects millions of people worldwide. PMID:25762993

  3. Influence of Typha domingensis in the removal of high P concentrations from water.

    PubMed

    Di Luca, G A; Maine, M A; Mufarrege, M M; Hadad, H R; Bonetto, C A

    2015-11-01

    A greenhouse experiment was conducted to evaluate the removal of high P concentration from water by vegetated and unvegetated wetlands. Reactors containing 4 kg of sediment and two plants of Typha domingensis (vegetated treatments) and reactors containing only sediment (unvegetated treatments) were arranged. Reactors were dosed with 100 and 500 mg L(-1) of P-PO4. The studied concentrations tried to simulate an accidental dump. Controls without P addition were also disposed. Water samples were collected periodically and analyzed for phosphorus. Sediment (0-3 (surface), 3-7 (medium) and 7-10 cm (deep)) and plant samples (roots, rhizomes, submerged leaves and aerial leaves) were collected at the beginning and at end of the experiment and were analyzed for total phosphorus. P fractionation was performed in the surface sediment layer. Relative growth rate (RGR) was calculated in each treatment considering initial and final plant height. P was efficiently removed from water in both, vegetated and unvegetated treatments. However, the major P removal was achieved in vegetated treatments. T. domingensis has a high capacity to tolerate and accumulate high P concentrations, especially in leaves, causing P accumulation in sediment to be significantly low in vegetated treatments. P accumulation was produced in the surface sediment layer (0-3 cm) in all treatments, mainly retained as iron-bound P. Present results point the large removal capacity of phosphate of systems planted with T. domingensis. Therefore T. domingensis is suitable for phytoremediation practice, being capable to tolerate high P concentration. PMID:26149856

  4. Crystal accumulation and very high short-circuit currents in rabbit urinary bladder.

    PubMed

    Loo, D D; Diamond, J M

    1985-01-01

    We describe a condition in rabbits characterized by CaCO3 crystal accumulation and very high short-circuit current (Isc) in the urinary bladder. The incidence of the condition was high in rabbits kept for 2 mo or more in the vivarium. The crystal mass in the bladder increased with age or time until it occupied up to one-third of the bladder volume and occasionally aggregated as stones, and the urine attained a sludgy consistency. In animals with sludgy urine, the urine excreted had a crystal content 20 times lower than that of urine contained in the bladder at time of death, implying retention of crystals in the bladder. Kidney stones were not detected in rabbits with bladder crystals, and bladder crystals were absent in rabbits with kidney stones induced experimentally by uremia. In old rabbits with sludgy urine the Isc, a measure of Na+ transport, was up to 46 microA/cm2 and averaged 12 microA/cm2, seven times the Isc of rabbits with nonsludgy urine. The increased Isc was entirely amiloride sensitive. Noise analysis showed it to arise entirely from increased channel density, without change in single-channel current. With one possible exception, we could not find bacterial infection or abnormalities in plasma aldosterone, GFR, or urinary [Na+], [Ca2+], pH, or osmolality that could explain the condition. The exception is that some unidentified component accounting for half the osmolality of nonsludgy urine is absent or at low concentration in sludgy urine. It remains unknown why the condition develops and whether CaCO3 crystals cause high Isc or vice versa or whether both result from a third factor. PMID:3970165

  5. Snow accumulation of a high alpine catchment derived from LiDAR measurements

    NASA Astrophysics Data System (ADS)

    Helfricht, K.; Schöber, J.; Seiser, B.; Fischer, A.; Stötter, J.; Kuhn, M.

    2012-12-01

    The spatial distribution of snow accumulation substantially affects the seasonal course of water storage and runoff generation in high mountain catchments. Whereas the areal extent of snow cover can be recorded by satellite data, spatial distribution of snow depth and hence snow water equivalent (SWE) is difficult to measure on catchment scale. In this study we present the application of airborne LiDAR (Light Detecting And Ranging) data to extract snow depths and accumulation distribution in an alpine catchment. Airborne LiDAR measurements were performed in a glacierized catchment in the Ötztal Alps at the beginning and the end of three accumulation seasons. The resulting digital elevation models (DEMs) were used to calculate surface elevation changes throughout the winter season. These surface elevation changes were primarily referred to as snow depths and are discussed concerning measured precipitation and the spatial characteristics of the accumulation distribution in glacierized and unglacierized areas. To determine the redistribution of catchment precipitation, snow depths were converted into SWE using a simple regression model. Snow accumulation gradients and snow redistribution were evaluated for 100 m elevation bands. Mean surface elevation changes of the whole catchment ranges from 1.97 m to 2.65 m within the analyzed accumulation seasons. By analyzing the distribution of the snow depths, elevation dependent patterns were obtained as a function of the topography in terms of aspect and slope. The high resolution DEMs show clearly the higher variation of snow depths in rough unglacierized areas compared to snow depths on smooth glacier surfaces. Mean snow depths in glacierized areas are higher than in unglacierized areas. Maximum mean snow depths of 100 m elevation bands are found between 2900 m and 3000 m a.s.l. in unglacierized areas and between 2800 m and 2900 m a.s.l. in glacierized areas, respectively. Calculated accumulation gradients range from 8% to

  6. Accumulate-Repeat-Accumulate-Accumulate-Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Sam; Thorpe, Jeremy

    2004-01-01

    Inspired by recently proposed Accumulate-Repeat-Accumulate (ARA) codes [15], in this paper we propose a channel coding scheme called Accumulate-Repeat-Accumulate-Accumulate (ARAA) codes. These codes can be seen as serial turbo-like codes or as a subclass of Low Density Parity Check (LDPC) codes, and they have a projected graph or protograph representation; this allows for a high-speed iterative decoder implementation using belief propagation. An ARAA code can be viewed as a precoded Repeat-and-Accumulate (RA) code with puncturing in concatenation with another accumulator, where simply an accumulator is chosen as the precoder; thus ARAA codes have a very fast encoder structure. Using density evolution on their associated protographs, we find examples of rate-lJ2 ARAA codes with maximum variable node degree 4 for which a minimum bit-SNR as low as 0.21 dB from the channel capacity limit can be achieved as the block size goes to infinity. Such a low threshold cannot be achieved by RA or Irregular RA (IRA) or unstructured irregular LDPC codes with the same constraint on the maximum variable node degree. Furthermore by puncturing the accumulators we can construct families of higher rate ARAA codes with thresholds that stay close to their respective channel capacity thresholds uniformly. Iterative decoding simulation results show comparable performance with the best-known LDPC codes but with very low error floor even at moderate block sizes.

  7. Sugar loss and enzyme inhibition due to oligosaccharides accumulation during high solids-loading enzymatic hydrolysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oligosaccharide accumulation occurs during high solid loading enzymatic hydrolysis of corn stover (CS) irrespective of using different pretreated corn stover (dilute acid: DA, ionic liquids: IL, ammonia fiber expansion: AFEX and extractive ammonia: EA). The methodology for large-scale separation of ...

  8. Anaerobic granule-based biofilms formation reduces propionate accumulation under high H2 partial pressure using conductive carbon felt particles.

    PubMed

    Xu, Heng; Wang, Cuiping; Yan, Kun; Wu, Jing; Zuo, Jiane; Wang, Kaijun

    2016-09-01

    Syngas based co-digestion is not only more economically attractive than separate syngas methanation but also able to upgrade biogas and increase overall CH4 amount simultaneously. However, high H2 concentration in the syngas could inhibit syntrophic degradation of propionate, resulting in propionate accumulation and even failure of the co-digestion system. In an attempt to reduce propionate accumulation via enhancing both H2 interspecies transfer (HIT) and direct interspecies electron transfer (DIET) pathways, layered granule-based biofilms induced by conductive carbon felt particles (CCFP) was employed. The results showed that propionate accumulation was effectively reduced with influent COD load up to 7gL(-1)d(-1). Two types of granule-based biofilms, namely biofilm adhered to CCFP (B-CCFP) and granules formed by self-immobilization (B-SI) were formed in the reactor. Clostridium, Syntrophobacter, Methanospirillum were possibly involved in HIT and Clostridium, Geobacter, Anaerolineaceae, Methanosaeta in DIET, both of which might be responsible for the high-rate propionate degradation. PMID:27289059

  9. Accumulate-Repeat-Accumulate-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Samuel; Thorpe, Jeremy

    2007-01-01

    Accumulate-repeat-accumulate-accumulate (ARAA) codes have been proposed, inspired by the recently proposed accumulate-repeat-accumulate (ARA) codes. These are error-correcting codes suitable for use in a variety of wireless data-communication systems that include noisy channels. ARAA codes can be regarded as serial turbolike codes or as a subclass of low-density parity-check (LDPC) codes, and, like ARA codes they have projected graph or protograph representations; these characteristics make it possible to design high-speed iterative decoders that utilize belief-propagation algorithms. The objective in proposing ARAA codes as a subclass of ARA codes was to enhance the error-floor performance of ARA codes while maintaining simple encoding structures and low maximum variable node degree.

  10. Refractive Secondary Solar Concentrator Demonstrated High-Temperature Operation

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.

    2002-01-01

    Space applications that utilize solar thermal energy--such as electric power conversion systems, thermal propulsion systems, and furnaces--require highly efficient solar concentration systems. The NASA Glenn Research Center is developing the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced lightweight primary concentrators, such as inflatable thin films, the refractive secondary concentrator enables very high system concentration ratios and very high temperatures. Last year, Glenn successfully demonstrated a secondary concentrator throughput efficiency of 87 percent, with a projected efficiency of 93 percent using an antireflective coating. Building on this achievement, Glenn recently successfully demonstrated high-temperature operation of the secondary concentrator when it was used to heat a rhenium receiver to 2330 F. The high-temperature demonstration of the concentrator was conducted in Glenn's 68-ft long Tank 6 thermal vacuum facility equipped with a solar simulator. The facility has a rigid panel primary concentrator that was used to concentrate the light from the solar simulator onto the refractive secondary concentrator. NASA Marshall Space Flight Center provided a rhenium cavity, part of a solar thermal propulsion engine, to serve as the high-temperature receiver. The prototype refractive secondary concentrator, measuring 3.5 in. in diameter and 11.2 in. long, is made of single-crystal sapphire. A water-cooled splash shield absorbs spillage light outside of the 3.5-in. concentrator aperture. Multilayer foil insulation composed of tungsten, molybdenum, and niobium is used to minimize heat loss from the hightemperature receiver. A liquid-cooled canister calorimeter is used to measure the heat loss through the multilayer foil insulation.

  11. Effects of puerarin on lipid accumulation and metabolism in high-fat diet-fed mice.

    PubMed

    Zheng, Guodong; Lin, Lezhen; Zhong, Shusheng; Zhang, Qingfeng; Li, Dongming

    2015-01-01

    In order to investigate the mechanisms by which puerarin from kudzu root extract regulates lipid metabolism, fifty mice were randomly assigned to five groups: normal diet, high-fat diet (HFD), and HFD containing 0.2%, 0.4% or 0.8% puerarin for 12 weeks. Body weight, intraperitioneal adipose tissue (IPAT) weight, serum biochemical parameters, and hepatic and feces lipids were measured. Activity and mRNA and protein expressions of hepatic lipid metabolism-related enzymes were analyzed. Compared with HFD, 0.4% and 0.8% puerarin significantly decreased body and IPAT weight. There was a significant decrease in the serum and hepatic concentrations of total cholesterol, triglycerides and leptin in mice fed the 0.4% and 0.8% puerarin diets compared with HFD. Fatty acid synthase activity was suppressed in mice fed the 0.4% and 0.8% puerarin diets, while the activities of AMP-activated protein kinase (AMPK), carnitine acyltransferase (CAT) and hormone-sensitive lipase (HSL) were increased. mRNA expression of peroxisome proliferator-activated receptor γ 2 (PPARγ 2) was down-regulated in liver of mice fed the 0.8% diet compared with HFD, while mRNA expression of CAT and HSL was considerably up-regulated by 0.4% and 0.8% puerarin diets. The protein expression of PPARγ2 in liver was decreased and those of p-AMPK, HSL and p-HSL were increased in mice fed 0.4% and 0.8% puerarin diets. These results suggest that > 0.4% puerarin influenced the activity, mRNA and protein levels of hepatic lipid metabolism-related enzymes, decreasing serum and liver lipids, body weight gain and fat accumulation. Puerarin might be beneficial to prevent lifestyle-related diseases. PMID:25822741

  12. CONCENTRATION DEPENDENT ACCUMULATION OF [3H]-DELTAMETHRIN IN SODIUM CHANNEL N AV1.2 EXPRESSING XENOPUS LAEVIS OOCYTES.

    EPA Science Inventory

    Disruption of neuronal voltage-sensitive sodium channels (VSSCs) by pyrethroid insecticides such as deltamethrin (DLT) has been widely studied using Xenopus laevis oocytes transfected with VSSC. However, the extent of pyrethroid accumulation in VSSC-expressing oocytes is unknown....

  13. ESTIMATION OF BIOTA SEDIMENT ACCUMULATION FACTOR (BSAF) FROM PAIRED OBSERVATIONS OF CHEMICAL CONCENTRATIONS IN BIOTA AND SEDIMENT (FINAL REPORT)

    EPA Science Inventory

    Biota Sediment Accumulation Factor (BSAF) is a parameter describing bioaccumulation of sediment-associated organic compounds or metals into tissues of ecological receptors. The report provides information on methodologies to estimate BSAF for nonionic organic chemicals.

  14. Effects of inorganic carbon concentration on carbon formation, nitrate utilization, biomass and oil accumulation of Nannochloropsis oculata CS 179.

    PubMed

    Lin, Qiang; Gu, Na; Li, Gang; Lin, Junda; Huang, Liangmin; Tan, LingLing

    2012-05-01

    This investigation examined the effects of the inorganic carbon concentration (4, 0.8 and 0 g/L NaHCO(3)) on the carbon formation, nitrate utilization, growth and fatty acids compositions of Nannochloropsis oculata. The dissolved inorganic carbon (DIC) concentration in the three treatments decreased sharply during the first 6 days, and the percentage of dissolved organic carbon (DOC) (% of total organic carbon (TOC)) decreased with the depletion of the DIC. The NO(3)(-) assimilation of the algae was correlated with the DIC concentration. The algae in the highest DIC treatment had the highest specific grow rate (0.0843 d(-1)) (P<0.0001), and their biomass and fatty acid methyl esters (FAME) productivity were 84.00 and 9.69 mg/L/d, respectively (P<0.0001). Contents of C16 and C18 series (% of FAME) were high and the C16:0 increased with the decrease of C18:1 during the cultivation. The iodine value (IV) of the algae was low at the low DIC media. PMID:22386465

  15. Effect of inoculum concentrations of Aspergillus flavus and A. parasiticus on aflatoxin accumulation and kernel infection in resistant and susceptible maize hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over a three year period, we compared aflatoxin accumulation and kernel infection in maize hybrids inoculated with six inoculum concentrations of Aspergillus flavus isolate NRRL 3357 or A. parasiticus isolate NRRL 6111 which is a norsolorinic acid producer. Aflatoxin resistant and susceptible mai...

  16. RELATIONSHIPS BETWEEN ACCUMULATION OF A 60KDA STRESS PROTEIN AND SCOPE-FOR-GROWTH IN MYTILIS EDULIS EXPOSED TO A RANGE OF COPPER CONCENTRATIONS

    EPA Science Inventory

    Blue mussels, Mytilus edulis, were exposed in the laboratory for 7 days to a range of Cu concentrations (O to 100 ug/liter) to test the feasibility of using the accumulation of a 60 kDa stress protein, also referred to as heat shock protein 60 (hsp60) as a molecular indicator of ...

  17. Significance of trophic transfer in predicting the high concentration of zinc in barnacles

    SciTech Connect

    Wang, W.X.; Qui, J.W.; Qian, P.Y.

    1999-09-01

    Barnacles are known to accumulate Zn to a phenomenal concentration, but physiological processes governing Zn accumulation are poorly defined. The authors determined the assimilation efficiency and efflux rate constant of Zn in barnacles (Balanus amphitrite) using radiotracer technique. Assimilation efficiency of Zn from ingested food ranged between 76 and 87% for the diatom diets and between 86 and 98% for the zooplankton preys. These AEs were the highest measured among aquatic invertebrates. Varying distribution in the soft tissues of zooplankton did not account for the variability of Zn AE observed among different zooplankton preys. Most Zn was distributed in the guts of the animals, presumably associated with the numerous granules beneath the gut epithelium. The efflux rate constant was 0.003 d{sup {minus}1}, and the calculated biological retention half-time was about 230 days. Using a simple bioenergetic-based kinetic model, the authors demonstrated that trophic transfer can account for such a high Zn concentration in barnacles. The predicted Zn concentrations in barnacles were directly comparable to the concentrations measured in Hong Kong coastal waters {micro}g. The high Zn concentration is related to its very efficient assimilation in barnacles coupled with a very low efflux rate. Biological variability must be fully appreciated before barnacles can be designated as an appropriate biomonitor of Zn contamination in coastal waters. The authors study suggests that metal concentration in aquatic animals can be predicted only when both physiological and geochemical processes are considered.

  18. Consumption of sucrose from infancy increases the visceral fat accumulation, concentration of triglycerides, insulin and leptin, and generates abnormalities in the adrenal gland.

    PubMed

    Díaz-Aguila, Yadira; Castelán, Francisco; Cuevas, Estela; Zambrano, Elena; Martínez-Gómez, Margarita; Muñoz, Alvaro; Rodríguez-Antolín, Jorge; Nicolás-Toledo, Leticia

    2016-03-01

    Consumption of sugar-sweetened beverages promotes the development of metabolic syndrome (MetS) and type 2 diabetes mellitus in humans. One factor related to the appearance of MetS components is the dysfunction of the adrenal gland. In fact, the experimental generation of hyperglycemia has been associated with morphological and microvascular changes in the adrenal glands of rats. We hypothesized that high sucrose consumption from infancy promotes histological disruption of the adrenal glands associated with the appearance of metabolic syndrome indicators. Male Wistar rats were separated at weaning (21 days old) into two groups: free access to tap water (control group, C) or 30 % sucrose diluted in water (sugar-fed group). After 12 weeks, high sucrose consumption promoted an increase in visceral fat accumulation, adipose cell number, and insulin resistance. Also, a rise in the concentration of triglycerides, very low-density lipoprotein, insulin and leptin was observed. In control rats, a histomorphometric asymmetry between the right and left adrenal glands was found. In the sugar-fed group, sucrose consumption produced a major change in adrenal gland asymmetry. No changes in corticosterone serum level were observed in either group. Our results suggest that a high sucrose liquid-diet from early life alters the morphology of adrenocortical zones, leading to MetS indicators. PMID:25834995

  19. Alaska pollack protein prevents the accumulation of visceral fat in rats fed a high fat diet.

    PubMed

    Oishi, Yoshie; Dohmoto, Nobuhiko

    2009-04-01

    In the first study (Study 1), 4-wk-old Sprague-Dawley (SD) rats were fed high fat diets containing casein, Alaska pollack, yellowfin tuna, or chicken as the protein source for 28 d. The purpose of this study was to compare the effect of Alaska pollack protein with other animal proteins (casein, yellowfin tuna, and chicken) on the prevention of visceral fat accumulation. We found that Alaska pollack protein was a more potent inhibitor of visceral fat accumulation than the other proteins (p<0.05). In the second study (Study 2), we determined the quantity of Alaska pollack protein needed to have an effect. To test this, 4-wk-old SD rats were fed diets containing different percentages of Alaska pollack proteins (0, 3, 10, 30 or 100%) to replace casein as the protein source for 28 d. The diets with 30 or 100% Alaska pollack protein as the protein source prevented visceral fat accumulation and elevated plasma adiponectin levels. Based on these findings, an inhibitory effect on the accumulation of visceral fats can be achieved by consuming a diet in which 30% or more of the total protein content comes from Alaska pollack. PMID:19436142

  20. Contamination from endocrine disrupters of the general population at low and high concentrations.

    PubMed

    Porta, Miquel; Pumarega, José; Gasull, Magda; Lopez, Tomàs

    2014-01-01

    Analyses of the concentrations of a given environmental compound usually show that most citizens have much lower concentrations than a certain minority, whose members have high body concentrations. Surveys of human exposure to chemicals do not usually integrate the number of chemical compounds detected per person and the concentration of each compound. This leaves untested relevant exposure situations, for example, whether individuals with low concentrations of some compounds have high concentrations of the other compounds. On scientific grounds, it is puzzling that this possibility, arithmetically and conceptually rather simple, has seldom if ever been tested in studies based on a representative sample of the general population. A study based on a representative sample of the general population of Catalonia (Spain) (Porta, Pumarega, & Gasull, 2012), which integrated the number of compounds detected per person and the concentration of each compound, found that more than half of the population had concentrations in the top quartile of 1 or more of the 19 persistent toxic substances (PTS) (pesticides and polychlorinated biphenyls) analyzed. Significant subgroups of the population accumulated PTS mixtures at high concentrations. For instance, 48% of women 60-74 years had concentrations of 6 or more PTS in the top quartile; half of the entire population had levels of 1-5 PTS above 500 ng/g, and less than 4% of citizens had all PTS in the lowest quartile. Thus, PTS concentrations appear low in most of the population only when each individual compound is looked at separately. It is not accurate to state that most of the population has low concentrations of PTS. The assessment of mixture effects must address the fact that most individuals are contaminated by PTS mixtures made of compounds at both low and high concentrations. PMID:24388190

  1. Rapid Cycling Synchrotrons and Accumulator Rings for High-Intensity Hadron Beams

    NASA Astrophysics Data System (ADS)

    Tang, Jingyu

    2014-02-01

    Boosted by the needs in high-energy physics and nuclear physics and also multidisciplinary applications, high-intensity proton synchrotrons and accumulator rings have been developed quickly around the world over the last 30 years. New projects and plans are proposed with even higher beam power. The proton beam power has increased from less than 10 kW in the 1970s to about 1 MW level today, and the required beam power in the coming decade is a few MW. This article reviews the achievements in designing and constructing rapid cycling synchrotrons (RCSs) and accumulator rings (ARs) and the future development trends, principally on proton beams but also including heavy ion beams. It presents the evolution of RCS and AR machines, today's design philosophy, relevant accelerator physics, and also state-of-the-art accelerator technology.

  2. Enhanced lipid accumulation of photoautotrophic microalgae by high-dose CO2 mimics a heterotrophic characterization.

    PubMed

    Sun, Zhilan; Dou, Xiao; Wu, Jun; He, Bing; Wang, Yuancong; Chen, Yi-Feng

    2016-01-01

    Microalgae possess higher photosynthetic efficiency and accumulate more neutral lipids when supplied with high-dose CO2. However, the nature of lipid accumulation under conditions of elevated CO2 has not been fully elucidated so far. We now revealed that the enhanced lipid accumulation of Chlorella in high-dose CO2 was as efficient as under heterotrophic conditions and this may be attributed to the driving of enlarged carbon source. Both photoautotrophic and heterotrophic cultures were established by using Chlorella sorokiniana CS-1. A series of changes in the carbon fixation, lipid accumulation, energy conversion, and carbon-lipid conversion under high-dose CO2 (1-10%) treatment were characterized subsequently. The daily carbon fixation rate of C. sorokiniana LS-2 in 10% CO2 aeration was significantly increased compared with air CO2. Correspondingly, double oil content (28%) was observed in 10% CO2 aeration, close to 32.3% produced under heterotrophic conditions. In addition, with 10% CO2 aeration, the overall energy yield (Ψ) in Chlorella reached 12.4 from 7.3% (with air aeration) because of the enhanced daily carbon fixation rates. This treatment also improved the energetic lipid yield (Ylipid/Es) with 4.7-fold, tending to the heterotrophic parameters. More significantly, 2.2 times of carbon-lipid conversion efficiency (ηClipid/Ctotal, 42.4%) was observed in 10% CO2 aeration, towards to 53.7% in heterotrophic cultures, suggesting that more fixed carbon might flow into lipid synthesis under both 10% CO2 aeration and heterotrophic conditions. Taken together, all our evidence showed that 10% CO2 may push photoautotrophic Chlorella to display heterotrophic-like efficiency at least in lipid production. It might bring us an efficient model of lipid production based on microalgal cells with high-dose CO2, which is essential to sustain biodiesel production at large scales. PMID:26712624

  3. Rice bran oil and oryzanol reduce plasma lipid and lipoprotein cholesterol concentrations and aortic cholesterol ester accumulation to a greater extent than ferulic acid in hypercholesterolemic hamsters.

    PubMed

    Wilson, Thomas A; Nicolosi, Robert J; Woolfrey, Benjamin; Kritchevsky, David

    2007-02-01

    Our laboratory has reported that the hypolipidemic effect of rice bran oil (RBO) is not entirely explained by its fatty acid composition. Because RBO has a greater content of the unsaponifiables, which also lower cholesterol compared to most vegetable oils, we wanted to know whether oryzanol or ferulic acid, two major unsaponifiables in RBO, has a greater cholesterol-lowering activity. Forty-eight F(1)B Golden Syrian hamsters (Mesocricetus auratus) (BioBreeders, Watertown, MA) were group housed (three per cage) in cages with bedding in an air-conditioned facility maintained on a 12-h light/dark cycle. The hamsters were fed a chow-based hypercholesterolemic diet (HCD) containing 10% coconut oil and 0.1% cholesterol for 2 weeks, at which time they were bled after an overnight fast (16 h) and segregated into 4 groups of 12 with similar plasma cholesterol concentrations. Group 1 (control) continued on the HCD, group 2 was fed the HCD containing 10% RBO in place of coconut oil, group 3 was fed the HCD plus 0.5% ferulic acid and group 4 was fed the HCD plus 0.5% oryzanol for an additional 10 weeks. After 10 weeks on the diets, plasma total cholesterol (TC) and non-high-density lipoprotein cholesterol (HDL-C) (very low- and low-density lipoprotein) concentrations were significantly lower in the RBO (-64% and -70%, respectively), the ferulic acid (-22% and -24%, respectively) and the oryzanol (-70% and -77%, respectively) diets compared to control. Plasma TC and non-HDL-C concentrations were also significantly lower in the RBO (-53% and -61%, respectively) and oryzanol (-61% and -70%, respectively) diets compared to the ferulic acid. Compared to control and ferulic acid, plasma HDL-C concentrations were significantly higher in the RBO (10% and 20%, respectively) and oryzanol (13% and 24%, respectively) diets. The ferulic acid diet had significantly lower plasma HDL-C concentrations compared to the control (-9%). The RBO and oryzanol diets were significantly lower for

  4. ATP production from adenine by a self-coupling enzymatic process: high-level accumulation under ammonium-limited conditions.

    PubMed

    Maruyama, A; Fujio, T

    2001-03-01

    To improve ATP production from adenine, we optimized cultivation and reaction conditions for the ATP producing strain, Corynebacterium ammoniagenes KY13510. In the conventional method, 28% NH4OH has been used both to adjust pH during cultivation and reaction, and to provide nitrogen for cell growth. In the ATP-producing reaction, high concentrations of inorganic phosphate and magnesium ion are needed, which form magnesium ammonium phosphate (MgNH4PO4) precipitate. To keep inorganic phosphate and magnesium ions soluble in the reaction mixture, it was indispensable to add phytic acid as a chelating agent of divalent metal ions. Under such conditions, 37 mg/ml (61.2 mM) ATP was accumulated in 13 h (Appl. Microbiol. Biotechnol. 21, 143 1985). If ammonium ion was depleted from the reaction mixture to avoid MgNH4 PO4 formation, we expected that there was no need to add phytic acid and ATP accumulation might be improved. Therefore, we obtained the cultured broth of C. ammoniagenes KY13510 strain with low ammonium ion content (less than 1 mg/ml as NH3) by the method that a part of alkali solution (28% NH4OH) for pH control was replaced with 10 N KOH. Using this culture broth, ATP producing reaction was done in 2-liter jar fermentor, controlling the pH of the reaction mixture with 10 N KOH. Under these conditions, the rate of ATP accumulation improved greatly, and 70.6 mg/ml (117 mM) ATP was accumulated in 28 h. The molar conversion ratio from adenine to ATP was about 82%. Phytic acid was slightly inhibitory to ATP formation under these ammonium-limited conditions. PMID:11330681

  5. The effect of carbohydrate accumulation and nitrogen deficiency on feedback regulation of photosynthesis in beech (Fagus sylvatica) under elevated CO2 concentration

    NASA Astrophysics Data System (ADS)

    Klem, K.; Urban, O.; Holub, P.; Rajsnerova, P.

    2012-04-01

    One of the main manifestations of global change is an increase in atmospheric CO2 concentration. Elevated concentration of CO2 has stimulating effect on plant photosynthesis and consequently also on the productivity. Long-term studies, however, show that this effect is progressively reduced due to feedback regulation of photosynthesis. The main causes of this phenomenon are considered as two factors: i) increased biomass production consumes a larger amount of nitrogen from the soil and this leads to progressive nitrogen limitation of photosynthesis, particularly at the level of the enzyme Rubisco, ii) the sink capacity is genetically limited and elevated CO2 concentration leads to increased accumulation of carbohydtrates (mainly sucrose, which is the main transport form of assimilates) in leaves. Increased concentrations of carbohydrates leads to a feedback regulation of photosynthesis by both, long-term feedback regulation of synthesis of the enzyme Rubisco, and also due to reduced capacity to produce ATP in the chloroplasts. However, mechanisms for interactive effects of nitrogen and accumulation of non-structural carbohydrates are still not well understood. Using 3-year-old Fagus sylvatica seedlings we have explored the interactive effects of nitrogen nutrition and sink capacity manipulation (sucrose feeding) on the dynamics of accumulation of non-structural carbohydrates and changes in photosynthetic parameters under ambient (385 μmol (CO2) mol-1) and elevated (700 μmol(CO2) mol-1) CO2 concentration. Sink manipulation by sucrose feeding led to a continuous increase of non-structural carbohydrates in leaves, which was higher in nitrogen fertilized seedlings. The accumulation of non-structural carbohydrates was also slightly stimulated by elevated CO2 concentration. Exponential decay (p <0.01) was observed in CO2 assimilation rate and stomatal conductance when the content of non-structural carbohydrates increased. However, this relationship was modified by the

  6. The accumulation and decay of near-bed suspended sand concentration due to waves and wave groups

    NASA Astrophysics Data System (ADS)

    Vincent, Christopher E.; Hanes, Daniel M.

    2002-09-01

    High resolution acoustic measurements were made of suspended sand and bedform dimensions caused by prototype-scale waves, both regular and in groups, over a mobile sand bed, in a very large wave channel. The changes in wave height at the beginning of the regular waves and within wave groups provides an opportunity to examine the time lag in the response of the sediment. For regular waves suspended sand concentrations lagged the forcing waves with the lag increasing with distance from the seabed. Typically, near-bed (1-2 cm) concentrations reached an equilibrium one to two wave-periods after the waves themselves had reached their steady height while at elevations of 10-15 cm the lag was longer. This lag was interpreted as due to the continual injection of turbulence into the water column from vortex processes associated with the oscillatory wave boundary layer over bedforms. A similar pattern was seen for wave groups, with the sand concentration near the bed lagging by the waves by one to two wave-periods and increasing with distance from the bed. Despite the controlled nature of these prototype-scale suspension experiments, with detailed measurements of bedforms and attempts to achieve 'equilibrium' bedforms, considerable variability (±30%) in the suspended sand concentration occurred between 'similar' forcing conditions, both at a wave-to-wave level and on the scale of groups and longer. The results suggest that considerable variability (a factor of two or more) should be expected in the suspension due to turbulence produced from wave boundary layers in natural environments, where bedforms are frequently continually evolving as the waves change their height, period and direction. A simple wave-average suspended-load model is used to describe the major temporal features of the suspension and to quantify the lag of the suspended sediment in relation to the waves and wave groups. Quantification of the lag is essential for assessing the transport of sand at infra

  7. Multijunction Photovoltaic Technologies for High-Performance Concentrators

    SciTech Connect

    McConnell, R.; Symko-Davies, M.

    2006-01-01

    Multijunction solar cells provide high-performance technology pathways leading to potentially low-cost electricity generated from concentrated sunlight. The National Center for Photovoltaics at the National Renewable Energy Laboratory has funded different III-V multijunction solar cell technologies and various solar concentration approaches. Within this group of projects, III-V solar cell efficiencies of 41% are close at hand and will likely be reported in these conference proceedings. Companies with well-developed solar concentrator structures foresee installed system costs of $3/watt--half of today's costs--within the next 2 to 5 years as these high-efficiency photovoltaic technologies are incorporated into their concentrator photovoltaic systems. These technology improvements are timely as new large-scale multi-megawatt markets, appropriate for high performance PV concentrators, open around the world.

  8. Multijunction Photovoltaic Technologies for High-Performance Concentrators: Preprint

    SciTech Connect

    McConnell, R.; Symko-Davies, M.

    2006-05-01

    Multijunction solar cells provide high-performance technology pathways leading to potentially low-cost electricity generated from concentrated sunlight. The National Center for Photovoltaics at the National Renewable Energy Laboratory has funded different III-V multijunction solar cell technologies and various solar concentration approaches. Within this group of projects, III-V solar cell efficiencies of 41% are close at hand and will likely be reported in these conference proceedings. Companies with well-developed solar concentrator structures foresee installed system costs of $3/watt--half of today's costs--within the next 2 to 5 years as these high-efficiency photovoltaic technologies are incorporated into their concentrator photovoltaic systems. These technology improvements are timely as new large-scale multi-megawatt markets, appropriate for high performance PV concentrators, open around the world.

  9. Estimation of Biota Sediment Accumulation Factor (BSAF) from Paired Observations of Chemical Concentrations in Biota and Sediment (External Review Draft)

    EPA Science Inventory

    This report was written in response to a March 2004 request from EPA's Ecological Risk Assessment Forum (ERAF) for information about estimating Biota-Sediment Accumulation Factors (BSAFs). BSAF is a parameter describing bioaccumulation of sediment-associated organic compounds or...

  10. Highly accurate boronimeter assay of concentrated boric acid solutions

    SciTech Connect

    Ball, R.M. )

    1992-01-01

    The Random-Walk Boronimeter has successfully been used as an on-line indicator of boric acid concentration in an operating commercial pressurized water reactor. The principle has been adapted for measurement of discrete samples to high accuracy and to concentrations up to 6000 ppm natural boron in light water. Boric acid concentration in an aqueous solution is a necessary measurement in many nuclear power plants, particularly those that use boric acid dissolved in the reactor coolant as a reactivity control system. Other nuclear plants use a high-concentration boric acid solution as a backup shutdown system. Such a shutdown system depends on rapid injection of the solution and frequent surveillance of the fluid to ensure the presence of the neutron absorber. The two methods typically used to measure boric acid are the chemical and the physical methods. The chemical method uses titration to determine the ionic concentration of the BO[sub 3] ions and infers the boron concentration. The physical method uses the attenuation of neutrons by the solution and infers the boron concentration from the neutron absorption properties. This paper describes the Random-Walk Boronimeter configured to measure discrete samples to high accuracy and high concentration.

  11. Molecular nitrogen in natural gas accumulations: Generation from sedimentary organic matter at high temperatures

    SciTech Connect

    Littke, R.; Krooss, B.; Frielingsdorf, J.; Idiz, E.

    1995-03-01

    The occurrence of natural gas accumulations with high percentages (up to 100%) of molecular nitrogen in various hydrocarbon provinces represents a largely unresolved problem and a serious exploration risk. In this context, a geochemical and basin modeling study was performed to evaluate the potential of sedimentary organic matter to generate molecular nitrogen. The masses of nitrogen present in coals - if converted into molecular nitrogen - are sufficient to fill commercial gas reservoirs. A calculation for gas accumulations in northern Germany, where percentages of molecular nitrogen range from less than 5 to greater than 90%, reveals that the molecular nitrogen generated in underlying coal-bearing strata is sufficient to account for the nitrogen gas even in the largest fields. In addition, much of the total nitrogen in clay-rich rock types, such as shales and mudstones, is fixed in sedimentary organic matter and may add to the nitrogen generation capacity of the coals.

  12. MEASUREMENT OF VAPOR PHASE ORGANIC COMPOUNDS AT HIGH CONCENTRATIONS

    EPA Science Inventory

    Laboratory, industrial, chemical, or other waste products may have constituents that evolve volatile organic compounds (VOCS) at very high concentrations. hese could pose human health risks during handling, storage, and disposal of the waste through inhalation, dermal exposure, o...

  13. Correlating concentrations of heavy metals in atmospheric deposition with respective accumulation in moss and natural surface soil for ecological land classes in Norway between 1990 and 2010.

    PubMed

    Nickel, Stefan; Hertel, Anne; Pesch, Roland; Schröder, Winfried; Steinnes, Eiliv; Uggerud, Hilde Thelle

    2015-06-01

    This study investigated whether statistical correlation of modeled atmospheric heavy metal deposition and respective accumulation in moss and natural surface soil varies across natural landscapes in Norway. Target metals were cadmium, lead, and mercury, and analyses were run between 1990 and 2010 on a 5-year interval. The landscape information was derived from the Ecological Land Classification of Europe. Correlations between concentration and respective deposition data were computed for each land class. The strongest correlations between heavy metal concentrations in atmospheric deposition and corresponding levels in moss and natural surface soil were observed for lead. Correlations for mercury were weaker compared to those calculated for cadmium and lead, indicating that atmospheric transport of mercury occurs at a larger spatial scale, while accumulation additionally seems to be influenced by factors operating on smaller scales. The correlation between concentrations in atmospheric deposition and moss is landscape-specific and metal-specific. The same holds true for the relations between heavy metal concentration in modeled atmospheric deposition and natural surface soil. The results of this investigation are in line with similar calculations from across Europe. They further confirm previous studies indicating that for Norway atmospheric transport is a main source of lead and cadmium accumulation in moss as well as in natural surface soil. PMID:25548023

  14. Surface potential due to charge accumulation during vacuum ultraviolet exposure for high-k and low-k dielectrics

    SciTech Connect

    Ren, H.; Sinha, H.; Sehgal, A.; Nichols, M. T.; Shohet, J. L.; Antonelli, G. A.; Nishi, Y.

    2010-08-16

    The surface potential due to charge accumulation during vacuum ultraviolet irradiation of high-k and low-k thin dielectric films is measured. Measurement of the substrate current, which is the sum of the charge-accumulation and photoinjection currents, allows an in situ monitoring of the charge accumulation during irradiation. The relationship between the substrate current and the calculated in situ surface potential is also found, eliminating the need for a separate surface-potential measurement. With a high photon dose, the surface potential and substrate current reach a steady-state value with no further net charge accumulation.

  15. Applications of nonimaging optics for very high solar concentrations

    SciTech Connect

    O`Gallagher, J.; Winston, R.

    1997-12-31

    Using the principles and techniques of nonimaging optics, solar concentrations that approach the theoretical maximum can be achieved. This has applications in solar energy collection wherever concentration is desired. In this paper, we survey recent progress in attaining and using high and ultrahigh solar fluxes. We review a number of potential applications for highly concentrated solar energy and the current status of the associated technology. By making possible new and unique applications for intense solar flux, these techniques have opened a whole new frontier for research and development of potentially economic uses of solar energy.

  16. Chemicals to enhance microalgal growth and accumulation of high-value bioproducts

    PubMed Central

    Yu, Xinheng; Chen, Lei; Zhang, Weiwen

    2015-01-01

    Photosynthetic microalgae have attracted significant attention as they can serve as important sources for cosmetic, food and pharmaceutical products, industrial materials and even biofuel biodiesels. However, current productivity of microalga-based processes is still very low, which has restricted their scale-up application. In addition to various efforts in strain improvement and cultivation optimization, it was proposed that the productivity of microalga-based processes can also be increased using various chemicals to trigger or enhance cell growth and accumulation of bioproducts. Herein, we summarized recent progresses in applying chemical triggers or enhancers to improve cell growth and accumulation of bioproducts in algal cultures. Based on their enhancing mechanisms, these chemicals can be classified into four categories:chemicals regulating biosynthetic pathways, chemicals inducing oxidative stress responses, phytohormones and analogs regulating multiple aspects of microalgal metabolism, and chemicals directly as metabolic precursors. Taken together, the early researches demonstrated that the use of chemical stimulants could be a very effective and economical way to improve cell growth and accumulation of high-value bioproducts in large-scale cultivation of microalgae. PMID:25741321

  17. Carbon accumulation rate of peatland in the High Arctic, Svalbard: Implications for carbon sequestration

    NASA Astrophysics Data System (ADS)

    Nakatsubo, Takayuki; Uchida, Masaki; Sasaki, Akiko; Kondo, Miyuki; Yoshitake, Shinpei; Kanda, Hiroshi

    2015-06-01

    Moss tundra that accumulates a thick peat layer is one of the most important ecosystems in the High Arctic, Svalbard. The importance of this ecosystem for carbon sequestration was estimated from the apparent rates of carbon accumulation based on the 14C age and amount of peat in the active layer. The study site at Stuphallet, Brøgger Peninsula, northwestern Svalbard was covered with a thick peat layer dominated by moss species such as Calliergon richardsonii, Paludella squarrosa, Tomenthypnum nitens, and Warnstorfia exannulata. The average thickness of the active layer (brown moss and peat) was approximately 28 cm in 1 August 2011. The calibrated (cal) age of peat from the bottom of the active layer (20-30 cm below the peatland surface) ranged from 81 to 701 cal yr BP (median value of 2σ range). Based on the total carbon (4.5-9.2 kg C m-2), the apparent rate of carbon accumulation in the active layer was 9.0-19.2 (g C m-2 yr-1), which is similar to or greater than the net ecosystem production or net primary production reported for other vegetation types in this area. Our data suggest that moss tundra plays an important role in carbon sequestration in this area.

  18. Rapid Sediment Accumulation Results in High Methane Effluxes from Coastal Sediments.

    PubMed

    Egger, Matthias; Lenstra, Wytze; Jong, Dirk; Meysman, Filip J R; Sapart, Célia J; van der Veen, Carina; Röckmann, Thomas; Gonzalez, Santiago; Slomp, Caroline P

    2016-01-01

    Globally, the methane (CH4) efflux from the ocean to the atmosphere is small, despite high rates of CH4 production in continental shelf and slope environments. This low efflux results from the biological removal of CH4 through anaerobic oxidation with sulfate in marine sediments. In some settings, however, pore water CH4 is found throughout the sulfate-bearing zone, indicating an apparently inefficient oxidation barrier for CH4. Here we demonstrate that rapid sediment accumulation can explain this limited capacity for CH4 removal in coastal sediments. In a saline coastal reservoir (Lake Grevelingen, The Netherlands), we observed high diffusive CH4 effluxes from the sediment into the overlying water column (0.2-0.8 mol m-2 yr-1) during multiple years. Linear pore water CH4 profiles and the absence of an isotopic enrichment commonly associated with CH4 oxidation in a zone with high rates of sulfate reduction (50-170 nmol cm-3 d-1) both suggest that CH4 is bypassing the zone of sulfate reduction. We propose that the rapid sediment accumulation at this site (~ 13 cm yr-1) reduces the residence time of the CH4 oxidizing microorganisms in the sulfate/methane transition zone (< 5 years), thus making it difficult for these slow growing methanotrophic communities to build-up sufficient biomass to efficiently remove pore water CH4. In addition, our results indicate that the high input of organic matter (~ 91 mol C m-2 yr-1) allows for the co-occurrence of different dissimilatory respiration processes, such as (acetotrophic) methanogenesis and sulfate reduction in the surface sediments by providing abundant substrate. We conclude that anthropogenic eutrophication and rapid sediment accumulation likely increase the release of CH4 from coastal sediments. PMID:27560511

  19. Rapid Sediment Accumulation Results in High Methane Effluxes from Coastal Sediments

    PubMed Central

    Lenstra, Wytze; Jong, Dirk; Meysman, Filip J. R.; Sapart, Célia J.; van der Veen, Carina; Röckmann, Thomas; Gonzalez, Santiago; Slomp, Caroline P.

    2016-01-01

    Globally, the methane (CH4) efflux from the ocean to the atmosphere is small, despite high rates of CH4 production in continental shelf and slope environments. This low efflux results from the biological removal of CH4 through anaerobic oxidation with sulfate in marine sediments. In some settings, however, pore water CH4 is found throughout the sulfate-bearing zone, indicating an apparently inefficient oxidation barrier for CH4. Here we demonstrate that rapid sediment accumulation can explain this limited capacity for CH4 removal in coastal sediments. In a saline coastal reservoir (Lake Grevelingen, The Netherlands), we observed high diffusive CH4 effluxes from the sediment into the overlying water column (0.2–0.8 mol m-2 yr-1) during multiple years. Linear pore water CH4 profiles and the absence of an isotopic enrichment commonly associated with CH4 oxidation in a zone with high rates of sulfate reduction (50–170 nmol cm-3 d-1) both suggest that CH4 is bypassing the zone of sulfate reduction. We propose that the rapid sediment accumulation at this site (~ 13 cm yr-1) reduces the residence time of the CH4 oxidizing microorganisms in the sulfate/methane transition zone (< 5 years), thus making it difficult for these slow growing methanotrophic communities to build-up sufficient biomass to efficiently remove pore water CH4. In addition, our results indicate that the high input of organic matter (~ 91 mol C m-2 yr-1) allows for the co-occurrence of different dissimilatory respiration processes, such as (acetotrophic) methanogenesis and sulfate reduction in the surface sediments by providing abundant substrate. We conclude that anthropogenic eutrophication and rapid sediment accumulation likely increase the release of CH4 from coastal sediments. PMID:27560511

  20. High Black Carbon (BC) Concentrations along Indian National Highways

    NASA Astrophysics Data System (ADS)

    Kumar, S.; Singh, A. K.; Singh, R. P.

    2015-12-01

    Abstract:Black carbon (BC), the optically absorbing component of carbonaceous aerosol, has direct influence on radiation budget and global warming. Vehicular pollution is one of the main sources for poor air quality and also atmospheric pollution. The number of diesel vehicles has increased on the Indian National Highways during day and night; these vehicles are used for the transport of goods from one city to another city and also used for public transport. A smoke plume from the vehicles is a common feature on the highways. We have made measurements of BC mass concentrations along the Indian National Highways using a potable Aethalometer installed in a moving car. We have carried out measurements along Varanasi to Kanpur (NH-2), Varanasi to Durgapur (NH-2), Varanasi to Singrauli (SH-5A) and Varanasi to Ghazipur (NH-29). We have found high concentration of BC along highways, the average BC mass concentrations vary in the range 20 - 40 µg/m3 and found high BC mass concentrations up to 600 μg/m3. Along the highways high BC concentrations were characteristics of the presence of industrial area, power plants, brick kilns and slow or standing vehicles. The effect of increasing BC concentrations along the National Highways and its impact on the vegetation and human health will be presented. Key Words: Black Carbon; Aethalometer; mass concentration; Indian National Highways.

  1. Biodegradation of phenol at high initial concentration by Alcaligenes faecalis.

    PubMed

    Jiang, Yan; Wen, Jianping; Bai, Jing; Jia, Xiaoqiang; Hu, Zongding

    2007-08-17

    Strain Alcaligenes faecalis was isolated and identified as a member of the genus Alcaligenes by using BIOLOG and 16S rDNA sequence analysis. The phenol biodegradation tests showed that the phenol-degrading potential of A. faecalis related greatly to the different physiological phases of inoculum. The maximum phenol degradation occurred at the late phase of the exponential growth stages, where 1600 mg L(-1) phenol was completely degraded within 76 h. A. faecalis secreted and accumulated a vast quantity of phenol hydroxylase in this physiological phase, which ensured that the cells could quickly utilize phenol as a sole carbon and energy source. In addition, the kinetic behavior of A. faecalis in batch cultures was also investigated over a wide range of initial phenol concentrations (0-1600 mg L(-1)) by using Haldane model. It was clear that the Haldane kinetic model adequately described the dynamic behavior of the phenol biodegradation by the strain of A. faecalis. PMID:17597295

  2. Chlamydomonas reinhardtii PsbS Protein Is Functional and Accumulates Rapidly and Transiently under High Light.

    PubMed

    Tibiletti, Tania; Auroy, Pascaline; Peltier, Gilles; Caffarri, Stefano

    2016-08-01

    Photosynthetic organisms must respond to excess light in order to avoid photo-oxidative stress. In plants and green algae the fastest response to high light is non-photochemical quenching (NPQ), a process that allows the safe dissipation of the excess energy as heat. This phenomenon is triggered by the low luminal pH generated by photosynthetic electron transport. In vascular plants the main sensor of the low pH is the PsbS protein, while in the green alga Chlamydomonas reinhardtii LhcSR proteins appear to be exclusively responsible for this role. Interestingly, Chlamydomonas also possesses two PsbS genes, but so far the PsbS protein has not been detected and its biological function is unknown. Here, we reinvestigated the kinetics of gene expression and PsbS and LhcSR3 accumulation in Chlamydomonas during high light stress. We found that, unlike LhcSR3, PsbS accumulates very rapidly but only transiently. In order to determine the role of PsbS in NPQ and photoprotection in Chlamydomonas, we generated transplastomic strains expressing the algal or the Arabidopsis psbS gene optimized for plastid expression. Both PsbS proteins showed the ability to increase NPQ in Chlamydomonas wild-type and npq4 (lacking LhcSR3) backgrounds, but no clear photoprotection activity was observed. Quantification of PsbS and LhcSR3 in vivo indicates that PsbS is much less abundant than LhcSR3 during high light stress. Moreover, LhcSR3, unlike PsbS, also accumulates during other stress conditions. The possible role of PsbS in photoprotection is discussed. PMID:27329221

  3. Characteristic of nitrous oxide production in partial denitrification process with high nitrite accumulation.

    PubMed

    Du, Rui; Peng, Yongzhen; Cao, Shenbin; Wang, Shuying; Niu, Meng

    2016-03-01

    Nitrous oxide (N2O) production during the partial denitrification process with nitrate (NO3(-)-N) to nitrite (NO2(-)-N) transformation ratio of 80% was investigated in this study. Results showed that N2O was seldom observed before complete depletion of NO3(-)-N, but it was closely related to the reduction of NO2(-)-N rather than NO3(-)-N. High COD/NO3(-)-N was in favor of N2O production in partial denitrification with high NO2(-)-N accumulation. It was seriously enhanced at constant acidic pH due to the free nitrous acid (FNA) inhibition. However, the N2O production was much lower at initial pH of 5.5 and 6.5 due to the pH increase during denitrification process. Significantly, the pH turning point could be chosen as a controlled parameter to denote the end of NO3(-)-N reduction, which could not only achieve high NO2(-)-N accumulation but also decrease the N2O production significantly for practical application. PMID:26760756

  4. Hemoglobin concentration of high-altitude Tibetans and Bolivian Aymara.

    PubMed

    Beall, C M; Brittenham, G M; Strohl, K P; Blangero, J; Williams-Blangero, S; Goldstein, M C; Decker, M J; Vargas, E; Villena, M; Soria, R; Alarcon, A M; Gonzales, C

    1998-07-01

    Elevated hemoglobin concentrations have been reported for high-altitude sojourners and Andean high-altitude natives since early in the 20th century. Thus, reports that have appeared since the 1970s describing relatively low hemoglobin concentration among Tibetan high-altitude natives were unexpected. These suggested a hypothesis of population differences in hematological response to high-altitude hypoxia. A case of quantitatively different responses to one environmental stress would offer an opportunity to study the broad evolutionary question of the origin of adaptations. However, many factors may confound population comparisons. The present study was designed to test the null hypothesis of no difference in mean hemoglobin concentration of Tibetan and Aymara native residents at 3,800-4,065 meters by using healthy samples that were screened for iron deficiency, abnormal hemoglobins, and thalassemias, recruited and assessed using the same techniques. The hypothesis was rejected, because Tibetan males had a significantly lower mean hemoglobin concentration of 15.6 gm/dl compared with 19.2 gm/dl for Aymara males, and Tibetan females had a mean hemoglobin concentration of 14.2 gm/dl compared with 17.8 gm/dl for Aymara females. The Tibetan hemoglobin distribution closely resembled that from a comparable, sea-level sample from the United States, whereas the Aymara distribution was shifted toward 3-4 gm/dl higher values. Genetic factors accounted for a very high proportion of the phenotypic variance in hemoglobin concentration in both samples (0.86 in the Tibetan sample and 0.87 in the Aymara sample). The presence of significant genetic variance means that there is the potential for natural selection and genetic adaptation of hemoglobin concentration in Tibetan and Aymara high-altitude populations. PMID:9696153

  5. Sugar loss and enzyme inhibition due to oligosaccharide accumulation during high solids-loading enzymatic hydrolysis

    DOE PAGESBeta

    Xue, Saisi; Uppugundla, Nirmal; Bowman, Michael J.; Cavalier, David; Da Costa Sousa, Leonardo; Dale, Bruce E.; Balan, Venkatesh

    2015-11-26

    Accumulation of recalcitrant oligosaccharides during high-solids loading enzymatic hydrolysis of cellulosic biomass reduces biofuel yields and increases processing costs for a cellulosic biorefinery. Recalcitrant oligosaccharides in AFEX-pretreated corn stover hydrolysate accumulate to the extent of about 18–25 % of the total soluble sugars in the hydrolysate and 12–18 % of the total polysaccharides in the inlet biomass (untreated), equivalent to a yield loss of about 7–9 kg of monomeric sugars per 100 kg of inlet dry biomass (untreated). These oligosaccharides represent a yield loss and also inhibit commercial hydrolytic enzymes, with both being serious bottlenecks for economical biofuel production frommore » cellulosic biomass. Very little is understood about the nature of these oligomers and why they are recalcitrant to commercial enzymes. This work presents a robust method for separating recalcitrant oligosaccharides from high solid loading hydrolysate in gramme quantities. Composition analysis, recalcitrance study and enzyme inhibition study were performed to understand their chemical nature. Results indicate that, oligosaccharide accumulation occurs during high solid loading enzymatic hydrolysis of corn stover (CS) irrespective of using different pretreated corn stover (dilute acid: DA, ionic liquids: IL, and ammonia fibre expansion: AFEX). The methodology for large-scale separation of recalcitrant oligosaccharides from 25 % solids-loading AFEXcorn stover hydrolysate using charcoal fractionation and size exclusion chromatography is reported for the first time. Oligosaccharides with higher degree of polymerization (DP) were recalcitrant towards commercial enzyme mixtures [Ctec2, Htec2 and Multifect pectinase (MP)] compared to lower DP oligosaccharides. Enzyme inhibition studies using processed substrates (Avicel and xylan) showed that low DP oligosaccharides also inhibit commercial enzymes. Addition of monomeric sugars to oligosaccharides increases the

  6. Sugar loss and enzyme inhibition due to oligosaccharide accumulation during high solids-loading enzymatic hydrolysis

    SciTech Connect

    Xue, Saisi; Uppugundla, Nirmal; Bowman, Michael J.; Cavalier, David; Da Costa Sousa, Leonardo; Dale, Bruce E.; Balan, Venkatesh

    2015-11-26

    Accumulation of recalcitrant oligosaccharides during high-solids loading enzymatic hydrolysis of cellulosic biomass reduces biofuel yields and increases processing costs for a cellulosic biorefinery. Recalcitrant oligosaccharides in AFEX-pretreated corn stover hydrolysate accumulate to the extent of about 18–25 % of the total soluble sugars in the hydrolysate and 12–18 % of the total polysaccharides in the inlet biomass (untreated), equivalent to a yield loss of about 7–9 kg of monomeric sugars per 100 kg of inlet dry biomass (untreated). These oligosaccharides represent a yield loss and also inhibit commercial hydrolytic enzymes, with both being serious bottlenecks for economical biofuel production from cellulosic biomass. Very little is understood about the nature of these oligomers and why they are recalcitrant to commercial enzymes. This work presents a robust method for separating recalcitrant oligosaccharides from high solid loading hydrolysate in gramme quantities. Composition analysis, recalcitrance study and enzyme inhibition study were performed to understand their chemical nature. Results indicate that, oligosaccharide accumulation occurs during high solid loading enzymatic hydrolysis of corn stover (CS) irrespective of using different pretreated corn stover (dilute acid: DA, ionic liquids: IL, and ammonia fibre expansion: AFEX). The methodology for large-scale separation of recalcitrant oligosaccharides from 25 % solids-loading AFEXcorn stover hydrolysate using charcoal fractionation and size exclusion chromatography is reported for the first time. Oligosaccharides with higher degree of polymerization (DP) were recalcitrant towards commercial enzyme mixtures [Ctec2, Htec2 and Multifect pectinase (MP)] compared to lower DP oligosaccharides. Enzyme inhibition studies using processed substrates (Avicel and xylan) showed that low DP oligosaccharides also inhibit commercial enzymes. Addition of monomeric sugars to oligosaccharides increases the

  7. Comparative transcriptome analysis to investigate the high starch accumulation of duckweed (Landoltia punctata) under nutrient starvation

    PubMed Central

    2013-01-01

    Background Duckweed can thrive on anthropogenic wastewater and produce tremendous biomass production. Due to its relatively high starch and low lignin percentage, duckweed is a good candidate for bioethanol fermentation. Previous studies have observed that water devoid of nutrients is good for starch accumulation, but its molecular mechanism remains unrevealed. Results This study globally analyzed the response to nutrient starvation in order to investigate the starch accumulation in duckweed (Landoltia punctata). L. punctata was transferred from nutrient-rich solution to distilled water and sampled at different time points. Physiological measurements demonstrated that the activity of ADP-glucose pyrophosphorylase, the key enzyme of starch synthesis, as well as the starch percentage in duckweed, increased continuously under nutrient starvation. Samples collected at 0 h, 2 h and 24 h time points respectively were used for comparative gene expression analysis using RNA-Seq. A comprehensive transcriptome, comprising of 74,797 contigs, was constructed by a de novo assembly of the RNA-Seq reads. Gene expression profiling results showed that the expression of some transcripts encoding key enzymes involved in starch biosynthesis was up-regulated, while the expression of transcripts encoding enzymes involved in starch consumption were down-regulated, the expression of some photosynthesis-related transcripts were down-regulated during the first 24 h, and the expression of some transporter transcripts were up-regulated within the first 2 h. Very interestingly, most transcripts encoding key enzymes involved in flavonoid biosynthesis were highly expressed regardless of starvation, while transcripts encoding laccase, the last rate-limiting enzyme of lignifications, exhibited very low expression abundance in all three samples. Conclusion Our study provides a comprehensive expression profiling of L. punctata under nutrient starvation, which indicates that nutrient starvation down

  8. Accumulated source imaging of brain activity with both low and high-frequency neuromagnetic signals

    PubMed Central

    Xiang, Jing; Luo, Qian; Kotecha, Rupesh; Korman, Abraham; Zhang, Fawen; Luo, Huan; Fujiwara, Hisako; Hemasilpin, Nat; Rose, Douglas F.

    2014-01-01

    Recent studies have revealed the importance of high-frequency brain signals (>70 Hz). One challenge of high-frequency signal analysis is that the size of time-frequency representation of high-frequency brain signals could be larger than 1 terabytes (TB), which is beyond the upper limits of a typical computer workstation's memory (<196 GB). The aim of the present study is to develop a new method to provide greater sensitivity in detecting high-frequency magnetoencephalography (MEG) signals in a single automated and versatile interface, rather than the more traditional, time-intensive visual inspection methods, which may take up to several days. To address the aim, we developed a new method, accumulated source imaging, defined as the volumetric summation of source activity over a period of time. This method analyzes signals in both low- (1~70 Hz) and high-frequency (70~200 Hz) ranges at source levels. To extract meaningful information from MEG signals at sensor space, the signals were decomposed to channel-cross-channel matrix (CxC) representing the spatiotemporal patterns of every possible sensor-pair. A new algorithm was developed and tested by calculating the optimal CxC and source location-orientation weights for volumetric source imaging, thereby minimizing multi-source interference and reducing computational cost. The new method was implemented in C/C++ and tested with MEG data recorded from clinical epilepsy patients. The results of experimental data demonstrated that accumulated source imaging could effectively summarize and visualize MEG recordings within 12.7 h by using approximately 10 GB of computer memory. In contrast to the conventional method of visually identifying multi-frequency epileptic activities that traditionally took 2–3 days and used 1–2 TB storage, the new approach can quantify epileptic abnormalities in both low- and high-frequency ranges at source levels, using much less time and computer memory. PMID:24904402

  9. Sterile Filtration of Highly Concentrated Protein Formulations: Impact of Protein Concentration, Formulation Composition, and Filter Material.

    PubMed

    Allmendinger, Andrea; Mueller, Robert; Huwyler, Joerg; Mahler, Hanns-Christian; Fischer, Stefan

    2015-10-01

    Differences in filtration behavior of concentrated protein formulations were observed during aseptic drug product manufacturing of biologics dependent on formulation composition. The present study investigates filtration forces of monoclonal antibody formulations in a small-scale set-up using polyvinylidene difluoride (PVDF) or polyethersulfone (PES) filters. Different factors like formulation composition and protein concentration related to differences in viscosity, as well as different filtration rates were evaluated. The present study showed that filtration behavior was influenced by the presence or absence of a surfactant in the formulation, which defines the interaction between filter membrane and surface active formulation components. This can lead to a change in filter resistance (PES filter) independent on the buffer system used. Filtration behavior was additionally defined by rheological non-Newtonian flow behavior. The data showed that high shear rates resulting from small pore sizes and filtration pressure up to 1.0 bar led to shear-thinning behavior for highly concentrated protein formulations. Differences in non-Newtonian behavior were attributed to ionic strength related to differences in repulsive and attractive interactions. The present study showed that the interplay of formulation composition, filter material, and filtration rate can explain differences in filtration behavior/filtration flux observed for highly concentrated protein formulations thus guiding filter selection. PMID:26149748

  10. Freeform solar concentrator with a highly asymmetric acceptance cone

    NASA Astrophysics Data System (ADS)

    Wheelwright, Brian; Angel, J. Roger P.; Coughenour, Blake; Hammer, Kimberly

    2014-10-01

    A solar concentrator with a highly asymmetric acceptance cone is investigated. Concentrating photovoltaic systems require dual-axis sun tracking to maintain nominal concentration throughout the day. In addition to collecting direct rays from the solar disk, which subtends ~0.53 degrees, concentrating optics must allow for in-field tracking errors due to mechanical misalignment of the module, wind loading, and control loop biases. The angular range over which the concentrator maintains <90% of on-axis throughput is defined as the optical acceptance angle. Concentrators with substantial rotational symmetry likewise exhibit rotationally symmetric acceptance angles. In the field, this is sometimes a poor match with azimuth-elevation trackers, which have inherently asymmetric tracking performance. Pedestal-mounted trackers with low torsional stiffness about the vertical axis have better elevation tracking than azimuthal tracking. Conversely, trackers which rotate on large-footprint circular tracks are often limited by elevation tracking performance. We show that a line-focus concentrator, composed of a parabolic trough primary reflector and freeform refractive secondary, can be tailored to have a highly asymmetric acceptance angle. The design is suitable for a tracker with excellent tracking accuracy in the elevation direction, and poor accuracy in the azimuthal direction. In the 1000X design given, when trough optical errors (2mrad rms slope deviation) are accounted for, the azimuthal acceptance angle is +/- 1.65°, while the elevation acceptance angle is only +/-0.29°. This acceptance angle does not include the angular width of the sun, which consumes nearly all of the elevation tolerance at this concentration level. By decreasing the average concentration, the elevation acceptance angle can be increased. This is well-suited for a pedestal alt-azimuth tracker with a low cost slew bearing (without anti-backlash features).

  11. Different mechanisms of extracellular adenosine accumulation by reduction of the external Ca(2+) concentration and inhibition of adenosine metabolism in spinal astrocytes.

    PubMed

    Eguchi, Ryota; Akao, Sanae; Otsuguro, Ken-ichi; Yamaguchi, Soichiro; Ito, Shigeo

    2015-05-01

    Extracellular adenosine is a neuromodulator in the central nervous system. Astrocytes mainly participate in adenosine production, and extracellular adenosine accumulates under physiological and pathophysiological conditions. Inhibition of intracellular adenosine metabolism and reduction of the external Ca(2+) concentration ([Ca(2+)]e) participate in adenosine accumulation, but the precise mechanisms remain unclear. This study investigated the mechanisms underlying extracellular adenosine accumulation in cultured rat spinal astrocytes. The combination of adenosine kinase and deaminase (ADK/ADA) inhibition and a reduced [Ca(2+)]e increased the extracellular adenosine level. ADK/ADA inhibitors increased the level of extracellular adenosine but not of adenine nucleotides, which was suppressed by inhibition of equilibrative nucleoside transporter (ENT) 2. Unlike ADK/ADA inhibition, a reduced [Ca(2+)]e increased the extracellular level not only of adenosine but also of ATP. This adenosine increase was enhanced by ENT2 inhibition, and suppressed by sodium polyoxotungstate (ecto-nucleoside triphosphate diphosphohydrolase inhibitor). Gap junction inhibitors suppressed the increases in adenosine and adenine nucleotide levels by reduction of [Ca(2+)]e. These results indicate that extracellular adenosine accumulation by ADK/ADA inhibition is due to the adenosine release via ENT2, while that by reduction of [Ca(2+)]e is due to breakdown of ATP released via gap junction hemichannels, after which ENT2 incorporates adenosine into the cells. PMID:26003082

  12. High levan accumulation in transgenic tobacco plants expressing the Gluconacetobacter diazotrophicus levansucrase gene.

    PubMed

    Banguela, Alexander; Arrieta, Juan G; Rodríguez, Raisa; Trujillo, Luis E; Menéndez, Carmen; Hernández, Lázaro

    2011-06-10

    Bacterial levansucrase (EC 2.4.1.10) converts sucrose into non-linear levan consisting of long β(2,6)-linked fructosyl chains with β(2,1) branches. Bacterial levan has wide food and non-food applications, but its production in industrial reactors is costly and low yielding. Here, we report the constitutive expression of Gluconacetobacter diazotrophicus levansucrase (LsdA) fused to the vacuolar targeting pre-pro-peptide of onion sucrose:sucrose 1-fructosyltransferase (1-SST) in tobacco, a crop that does not naturally produce fructans. In the transgenic plants, levan with degree of polymerization above 10(4) fructosyl units was detected in leaves, stem, root, and flowers, but not in seeds. High levan accumulation in leaves led to gradual phenotypic alterations that increased with plant age through the flowering stage. In the transgenic lines, the fructan content in mature leaves varied from 10 to 70% of total dry weight. No oligofructans were stored in the plant organs, although the in vitro reaction of transgenic LsdA with sucrose yielded β(2,1)-linked FOS and levan. Transgenic lines with levan representing up to 30mgg(-1) of fresh leaf weight produced viable seeds and the polymer accumulation remained stable in the tested T1 and T2 progenies. The lsdA-expressing tobacco represents an alternative source of highly polymerized levan. PMID:21540065

  13. Atlas of Rice Grain Filling-Related Metabolism under High Temperature: Joint Analysis of Metabolome and Transcriptome Demonstrated Inhibition of Starch Accumulation and Induction of Amino Acid Accumulation

    PubMed Central

    Yamakawa, Hiromoto; Hakata, Makoto

    2010-01-01

    High temperature impairs grain filling by inhibiting the deposition of storage materials such as starch and protein. To comprehend its impact on grain filling metabolism in rice (Oryza sativa), levels of metabolites and transcripts related to central pathways of metabolism were simultaneously determined in developing caryopses exposed to high temperature (33°C/28°C) and a control temperature (25°C/20°C) during the milky stage. A capillary electrophoresis-based metabolomic analysis revealed that high temperature increased the accumulation of sucrose and pyruvate/ oxaloacetate-derived amino acids and decreased levels of sugar phosphates and organic acids involved in glycolysis/gluconeogenesis and the tricarboxylic acid (TCA) cycle, respectively. A transcriptomic analysis using a whole genome-covering microarray unraveled the possible metabolic steps causing the shortage of storage materials under the elevated temperature. Starch deposition might be impaired by down-regulation of sucrose import/degradation and starch biosynthesis, and/or up-regulation of starch degradation as well as inefficient ATP production by an inhibited cytochrome respiration chain, as indicated by the response of gene expression to high temperature. Amino acid accumulation might be attributed to the heat-stable import of amino acids into the caryopsis and/or repression of protein synthesis especially the tRNA charging step under high temperature. An atlas showing the effect of high temperature on levels of metabolites and gene expression in the central metabolic pathways is presented. PMID:20304786

  14. Combined effects of elevated temperature and CO2 concentration on Cd and Zn accumulation dynamics in Triticum aestivum L.

    PubMed

    Wang, Xiaoheng; Li, Yu; Lu, Hong; Wang, Shigong

    2016-09-01

    A simulated climate warming experiment was conducted to evaluate the combined effects of elevated temperature and CO2 concentration on the bioaccumulation, translocation and subcellular distributions of Cd and Zn in wheat seedlings (Triticum aestivum L. cv. Xihan 1.) at Dingxi, Gansu Province, China. The objective was to find evidence that global climate change is affecting the bioaccumulation of Cd and Zn in T. aestivum L. cv. Xihan 1. The results showed that compared to control A, elevated temperature and CO2 increased Cd bioaccumulation in the shoots by 1.4-2.5 times, and increased that in the roots by 1.2-1.5 times, but decreased Zn levels in wheat shoots by 1.4-2.0 times, while decreased that in the roots by 1.6-1.9 times. Moreover, temperature and CO2 concentration increase also led to increased Cd concentration, and decreased Zn concentration in subcellular compartments of wheat seedlings. The largest Cd concentration increase (174.4%) was observed in the cell wall and debris fractions of shoots after they were subjected to the highest CO2 and temperature treatment (TC3). The largest Zn concentration decrease (53.1%) was observed in the soluble (F3) fractions of shoots after they were subjected to the medium CO2 and temperature treatment (TC2). The temperature and CO2 increase had no significant effect on the proportional distribution of Cd and Zn in the subcellular fractions. The root-to-shoot translocation of Cd increased with the increasing temperature and CO2 concentration. However, the Zn distributions only fluctuated within a small range. PMID:27593278

  15. Heavy metal accumulation in Diplodus annularis, Liza aurata, and Solea vulgaris relevant to their concentration in water and sediment from the southwestern Mediterranean (coast of Sfax).

    PubMed

    Ben Salem, Zohra; Ayadi, Habib

    2016-07-01

    The concentrations of heavy metals (Cd, Cu, Fe, Pb, Ni, and Zn) were measured in the liver, gills, and muscle of Solea vulgaris, Liza aurata, and Diplodus annularis, collected from the south coast of Sfax (Gabes Gulf, southwestern Mediterranean). The concentrations of heavy metals in water exhibited the following decreasing order (expressed in μg l(-1)): Fe > Ni > Zn > Cu > Pb > Cd whereas the trend is somewhat different in sediments (mg kg(-1) D.W.) Fe > Zn > Pb > Ni > Cu > Cd. The levels of heavy metals varied significantly among fish species and tissues. Heavy metal levels were found generally higher in the liver and gills than the muscle in all species. The liver was the target organ for Cd, Cu, Fe, Ni, and Zn accumulation. Nickel and lead, however, exhibited their highest concentrations in the gills. The three studied fishes showed a difference in metals accumulation decreasing in following order S. vulgaris > D. annularis > L. aurata. Solea vulgaris with the highest TFwater, TFsediment, and metal concentrations in tissues would be considered as a potential bio-indicator in the south coast of Sfax for the assessment of environmental pollution status. Comparative studies with Luza zone indicate considerable bioaccumulation of heavy metals (Pb and Zn) in the various tissues of fish samples of the south coast of Sfax. PMID:27040537

  16. CO₂ enrichment can produce high red leaf lettuce yield while increasing most flavonoid glycoside and some caffeic acid derivative concentrations.

    PubMed

    Becker, Christine; Kläring, Hans-Peter

    2016-05-15

    Carbon dioxide (CO2) enrichment is a common practice in greenhouses to increase crop yields up to 30%. Yet, reports on the effect on foliar phenolic compounds vary. We studied the effect on two red leaf lettuce cultivars, grown for 25 days in growth chambers at CO2 concentrations of 200 or 1,000 ppm, with some plants exchanged between treatments after 11 days. As expected, head mass increased with higher CO2 concentration. Regression analysis, corrected for head mass, showed increased concentrations of most flavonoid glycosides at high CO2 concentrations while only some caffeic acid derivatives were increased, and not uniformly in both cultivars. Sugar concentrations increased with CO2 concentration. Generally, conditions in the 10 days before harvest determined concentrations. We suspect that phenolic compounds were mainly accumulated because plenty of precursors were available. The results indicate that CO2 enrichment can result in high yields of red leaf lettuce rich in phenolic compounds. PMID:26776031

  17. Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia.

    PubMed

    Prtenjak, Maja Telišman; Srnec, Lidija; Peternel, Renata; Madžarević, Valentina; Hrga, Ivana; Stjepanović, Barbara

    2012-11-01

    We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002-2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m(3)) for our analysis: period A (3-4 September 2002) and period B (6-7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002-2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m(3). Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration. PMID:22410823

  18. Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia

    NASA Astrophysics Data System (ADS)

    Prtenjak, Maja Telišman; Srnec, Lidija; Peternel, Renata; Madžarević, Valentina; Hrga, Ivana; Stjepanović, Barbara

    2012-11-01

    We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002-2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m3) for our analysis: period A (3-4 September 2002) and period B (6-7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002-2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m3. Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration.

  19. Effects of exposure to high concentrations of waterborne Tl on K and Tl concentrations in Chironomus riparius larvae.

    PubMed

    Belowitz, Ryan; Leonard, Erin M; O'Donnell, Michael J

    2014-11-01

    Thallium (Tl) is a non-essential metal which is released into the environment primarily as the result of anthropogenic activities such as fossil fuel burning and smelting of ores. The ionic radius of monovalent Tl⁺ is similar to that of K⁺ and Tl⁺ may thus interfere with K⁺-dependent processes. We determined that the acute (48 h) lethal concentration where 50% of the organisms do not survive (LC₅₀) of Tl for 4th instar Chironomus riparius larvae was 723 μmol L⁻¹. Accumulation of Tl by the whole animal was saturable, with a maximum accumulation (Jmax) of 4637 μmol kg⁻¹ wet mass, and K(D) of 670 μmol Tl l⁻¹. Tl accumulation by the gut appeared saturable at the lowest four Tl concentrations, with a Jmax of 2560 μmol kg⁻¹ wet mass and a K(D) of 54.5 μmol Tl l⁻¹. The saturable accumulation at the gut may be indicative of a limited capacity for intracellular detoxification, such as storage in lysosomes or complexation with metal-binding proteins. Tl accumulation by the hemolymph was found to be linear and Tl concentrations in the hemolymph were ~75% of the exposure concentration at Tl exposures >26.9 μmol L⁻¹. There was not a significant decrease in whole animal, gut or hemolymph K during exposure to waterborne Tl at any of the concentrations tested (up to 1500 μmol L⁻¹). The avoidance of hypokalemia by C. riparius larvae may contribute to survival during acute waterborne exposures to Tl. PMID:25046737

  20. The fate of fertilizer nitrogen in a high nitrate accumulated agricultural soil.

    PubMed

    Quan, Zhi; Huang, Bin; Lu, Caiyan; Shi, Yi; Chen, Xin; Zhang, Haiyang; Fang, Yunting

    2016-01-01

    Well-acclimatized nitrifiers in high-nitrate agricultural soils can quickly nitrify NH4(+) into NO3(-) subject to leaching and denitrifying loss. A 120-day incubation experiment was conducted using a greenhouse soil to explore the fates of applied fertilizer N entering into seven soil N pools and to examine if green manure (as ryegrass) co-application can increase immobilization of the applied N into relatively stable N pools and thereby reduce NO3(-) accumulation and loss. We found that 87-92% of the applied (15)N-labelled NH4(+) was rapidly recovered as NO3(-) since day 3 and only 2-4% as microbial biomass and soil organic matter (SOM), while ryegrass co-application significantly decreased its recovery as NO3(-) but enhanced its recovery as SOM (17%) at the end of incubation. The trade-off relationship between (15)N recoveries in microbial biomass and SOM indicated that ryegrass co-application stabilized newly immobilized N via initial microbial uptake and later breakdown. Nevertheless, ryegrass application didn't decrease soil total NO3(-) accumulation due to its own decay. Our results suggest that green manure co-application can increase immobilization of applied N into stable organic N via microbial turnover, but the quantity and quality of green manure should be well considered to reduce N release from itself. PMID:26868028

  1. The fate of fertilizer nitrogen in a high nitrate accumulated agricultural soil

    NASA Astrophysics Data System (ADS)

    Quan, Zhi; Huang, Bin; Lu, Caiyan; Shi, Yi; Chen, Xin; Zhang, Haiyang; Fang, Yunting

    2016-02-01

    Well-acclimatized nitrifiers in high-nitrate agricultural soils can quickly nitrify NH4+ into NO3- subject to leaching and denitrifying loss. A 120-day incubation experiment was conducted using a greenhouse soil to explore the fates of applied fertilizer N entering into seven soil N pools and to examine if green manure (as ryegrass) co-application can increase immobilization of the applied N into relatively stable N pools and thereby reduce NO3- accumulation and loss. We found that 87-92% of the applied 15N-labelled NH4+ was rapidly recovered as NO3- since day 3 and only 2-4% as microbial biomass and soil organic matter (SOM), while ryegrass co-application significantly decreased its recovery as NO3- but enhanced its recovery as SOM (17%) at the end of incubation. The trade-off relationship between 15N recoveries in microbial biomass and SOM indicated that ryegrass co-application stabilized newly immobilized N via initial microbial uptake and later breakdown. Nevertheless, ryegrass application didn’t decrease soil total NO3- accumulation due to its own decay. Our results suggest that green manure co-application can increase immobilization of applied N into stable organic N via microbial turnover, but the quantity and quality of green manure should be well considered to reduce N release from itself.

  2. The fate of fertilizer nitrogen in a high nitrate accumulated agricultural soil

    PubMed Central

    Quan, Zhi; Huang, Bin; Lu, Caiyan; Shi, Yi; Chen, Xin; Zhang, Haiyang; Fang, Yunting

    2016-01-01

    Well-acclimatized nitrifiers in high-nitrate agricultural soils can quickly nitrify NH4+ into NO3− subject to leaching and denitrifying loss. A 120-day incubation experiment was conducted using a greenhouse soil to explore the fates of applied fertilizer N entering into seven soil N pools and to examine if green manure (as ryegrass) co-application can increase immobilization of the applied N into relatively stable N pools and thereby reduce NO3− accumulation and loss. We found that 87–92% of the applied 15N-labelled NH4+ was rapidly recovered as NO3− since day 3 and only 2–4% as microbial biomass and soil organic matter (SOM), while ryegrass co-application significantly decreased its recovery as NO3− but enhanced its recovery as SOM (17%) at the end of incubation. The trade-off relationship between 15N recoveries in microbial biomass and SOM indicated that ryegrass co-application stabilized newly immobilized N via initial microbial uptake and later breakdown. Nevertheless, ryegrass application didn’t decrease soil total NO3− accumulation due to its own decay. Our results suggest that green manure co-application can increase immobilization of applied N into stable organic N via microbial turnover, but the quantity and quality of green manure should be well considered to reduce N release from itself. PMID:26868028

  3. [Toxic effects of high concentrations of ammonia on Euglena gracilis].

    PubMed

    Liu, Yan; Shi, Xiao-Rong; Cui, Yi-Bin; Li, Mei

    2013-11-01

    Ammonia is among the common contaminants in aquatic environments. The present study aimed at evaluation of the toxicity of ammonia at high concentration by detecting its effects on the growth, pigment contents, antioxidant enzyme activities, and DNA damage (comet assay) of a unicellular microalga, Euglena gracilis. Ammonia restrained the growth of E. gracilis, while at higher concentrations, ammonia showed notable inhibition effect, the growth at 2 000 mg x L(-1) was restrained to 55.7% compared with that of the control; The contents of photosynthetic pigments and protein went up with increasing ammonia dosage and decreased when the ammonia concentration was above 1000 mg x L(-1); In addition, there was an obvious increase in SOD and POD activities, at higher concentration (2 000 mg x L(-1)), activities of SOD and POD increased by 30.7% and 49.4% compared with those of the control, indicating that ammonia could promote activities of antioxidant enzymes in E. gracilis; The degree of DNA damage observed in the comet assay increased with increasing ammonia concentration, which suggested that high dose of ammonia may have potential mutagenicity on E. gracilis. PMID:24455949

  4. Europium doped lanthanum zirconate nanoparticles with high concentration quenching

    SciTech Connect

    Alaparthi, Suresh B.; Lu, Long; Tian, Yue; Mao, Yuanbing

    2014-01-01

    Graphical abstract: - Highlights: • Eu:La{sub 2}Zr{sub 2}O{sub 7} nanoparticles were prepared facilely by a kinetically modified molten salt method. • High color purity and concentration quenching were achieved in these La{sub 2}Zr{sub 2}O{sub 7}:Eu nanoparticles. • Concentration quenching mechanism was discussed for Eu{sup 3+} in these Eu:La{sub 2}Zr{sub 2}O{sub 7} nanoparticles. - Abstract: A series of Eu{sup 3+} doped lanthanum zirconate (La{sub 2}Zr{sub 2}O{sub 7}) nanoparticles (NPs, 20 ± 5 nm in diameter) with cubic fluorite structure were facilely synthesized by a kinetically modified molten salt synthetic (MSS) process and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and photoluminescence spectra (PL). Under the excitation of 405 nm, intense red emission with high color purity can be observed in the Eu{sup 3+} doped La{sub 2}Zr{sub 2}O{sub 7} NPs. Moreover, the as-prepared Eu:La{sub 2}Zr{sub 2}O{sub 7} NPs possess high concentration quenching, which is as high as ∼32.5 mol% of europium dopants in the La{sub 2}Zr{sub 2}O{sub 7} host. The corresponding concentration quenching mechanism was discussed as well. Our results confirm that the kinetically modified MSS process is a promising approach for preparing rare earth (RE) ions doped A{sub 2}B{sub 2}O{sub 7} nanoparticles with uniform RE doping and high concentration quenching.

  5. The chromium accumulation and its physiological effects in juvenile rockfish, Sebastes schlegelii, exposed to different levels of dietary chromium (Cr(6+)) concentrations.

    PubMed

    Kim, Jun-Hwan; Kang, Ju-Chan

    2016-01-01

    Juvenile rockfish (mean length 13.7±1.7 cm, and mean weight 55.6±4.8 g) were exposed for 4 weeks with the different levels of dietary chromium (Cr(6+)) at 0, 30, 60, 120 and 240 mg/kg. The profile of chromium in the tissues of rockfish is dependent on the exposure periods and chromium concentration. After 4 weeks, the order of chromium accumulation in tissues was liver>kidney>spleen>intestine>gill>muscle. The dietary chromium exposure decreased the growth rate and hepatosomatic index of rockfish. The major hematological findings were significant decrease in the red blood cell (RBC) count, hematocrit (Ht) value, and hemoglobin (Hb) concentration exposed to ≥120 mg/kg chromium concentrations. The dietary chromium exposure (≥120 mg/kg) led to notable increase in glucose, cholesterol, glutamic oxalate transaminase (GOT), and glutamic pyruvate transaminase (GPT) in plasma, whereas there was no considerable change in calcium, magnesium, total protein, and alkaline phosphatase (ALP). The results indicated that the dietary chromium exposure to rockfish can induce significant chromium accumulation in the specific tissues, inhibition of growth, and hematological alterations. PMID:26705966

  6. Manufacture of concentrated, lipid-based oxygen microbubble emulsions by high shear homogenization and serial concentration.

    PubMed

    Thomson, Lindsay M; Polizzotti, Brian D; McGowan, Frances X; Kheir, John N

    2014-01-01

    Gas-filled microbubbles have been developed as ultrasound contrast and drug delivery agents. Microbubbles can be produced by processing surfactants using sonication, mechanical agitation, microfluidic devices, or homogenization. Recently, lipid-based oxygen microbubbles (LOMs) have been designed to deliver oxygen intravenously during medical emergencies, reversing life-threatening hypoxemia, and preventing subsequent organ injury, cardiac arrest, and death. We present methods for scaled-up production of highly oxygenated microbubbles using a closed-loop high-shear homogenizer. The process can produce 2 L of concentrated LOMs (90% by volume) in 90 min. Resulting bubbles have a mean diameter of ~2 μm, and a rheologic profile consistent with that of blood when diluted to 60 volume %. This technique produces LOMs in high capacity and with high oxygen purity, suggesting that this technique may be useful for translational research labs. PMID:24894333

  7. Manufacture of Concentrated, Lipid-based Oxygen Microbubble Emulsions by High Shear Homogenization and Serial Concentration

    PubMed Central

    Thomson, Lindsay M.; Polizzotti, Brian D.; McGowan, Frances X.; Kheir, John N.

    2014-01-01

    Gas-filled microbubbles have been developed as ultrasound contrast and drug delivery agents. Microbubbles can be produced by processing surfactants using sonication, mechanical agitation, microfluidic devices, or homogenization. Recently, lipid-based oxygen microbubbles (LOMs) have been designed to deliver oxygen intravenously during medical emergencies, reversing life-threatening hypoxemia, and preventing subsequent organ injury, cardiac arrest, and death. We present methods for scaled-up production of highly oxygenated microbubbles using a closed-loop high-shear homogenizer. The process can produce 2 L of concentrated LOMs (90% by volume) in 90 min. Resulting bubbles have a mean diameter of ~2 μm, and a rheologic profile consistent with that of blood when diluted to 60 volume %. This technique produces LOMs in high capacity and with high oxygen purity, suggesting that this technique may be useful for translational research labs. PMID:24894333

  8. Chitosan macroporous foams obtained in highly concentrated emulsions as templates.

    PubMed

    Miras, Jonathan; Vílchez, Susana; Solans, Conxita; Esquena, Jordi

    2013-11-15

    Emulsion templating is an effective route for the preparation of macroporous polymer foams, with well-defined pore structures. This kind of material is usually obtained by polymerization or crosslinking in the external phase of highly concentrated emulsions. The present article describes the synthesis of macroporous foams based on a cationic polymer, chitosan, crosslinked with genipin, a natural crosslinker. The phase behavior was used to study the influence of chitosan on surfactant self-aggregation. Hexagonal and lamellar liquid crystalline structures could be obtained in the presence of chitosan, and polymer did not greatly influence the geometric lattice parameters of these self-aggregates. O/W highly concentrated emulsions were obtained in the presence of chitosan in the continuous phase, which allowed reducing both droplet size and polydispersity. The emulsions were stable during the time required for crosslinking, obtaining macroporous foams with high pore volume and degree of crosslinking. PMID:24011788

  9. Bioconversion of high concentrations of hydrogen sulfide to elemental sulfur in airlift bioreactor.

    PubMed

    Zytoon, Mohamed Abdel-Monaem; AlZahrani, Abdulraheem Ahmad; Noweir, Madbuli Hamed; El-Marakby, Fadia Ahmed

    2014-01-01

    Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift bioreactor fed with high concentrations of H2S with special emphasis on the effect of pH in combination with other factors such as H2S loading rate, oxygen availability, and sulfide accumulation. H2S inlet concentrations between 1,008 ppm and 31,215 ppm were applied and elimination capacities up to 113 g H2S m(-3) h(-1) were achieved in the airlift bioreactor under investigation at a pH range 6.5-8.5. Acidic pH values reduced the elimination capacity. Elemental sulfur recovery up to 95% was achieved under oxygen limited conditions (DO < 0.2 mg/L) and at higher pH values. The sulfur oxidizing bacteria in the bioreactor tolerated accumulated dissolved sulfide concentrations >500 mg/L at pH values 8.0-8.5, and near 100% removal efficiency was achieved. Overall, the resident microorganisms in the studied airlift bioreactor favored pH values in the alkaline range. The bioreactor performance in terms of elimination capacity and sulfur recovery was better at pH range 8-8.5. PMID:25147857

  10. Decomposition of high concentration SF6 using an electron beam

    NASA Astrophysics Data System (ADS)

    Son, Youn-Suk; Lee, Sung-Joo; Choi, Chang Yong; Park, Jun-Hyeong; Kim, Tak-Hyun; Jung, In-Ha

    2016-07-01

    In this study, high concentration SF6 (2-10%) was decomposed using an electron beam irradiation. Various influential factors were investigated to improve the destruction and removal efficiency (DRE) of SF6. The initial concentrations of SF6, absorbed doses, SF6/H2 ratios and retention times were the main factors of concern. As a result, the DRE increased as the adsorbed dose and retention time increased. The DRE of SF6 also increased up to 20% approximately when H2 was added to the reaction mixture. On the other hand, the DRE of SF6 decreased as initial concentrations of SF6 increased. Finally, the main by-product formed from SF6 decomposition by the electron beam was HF.

  11. Athletic Activity and Hormone Concentrations in High School Female Athletes

    PubMed Central

    Wojtys, Edward M.; Jannausch, Mary L.; Kreinbrink, Jennifer L.; Harlow, Siobán D.; Sowers, MaryFran R.

    2015-01-01

    Context: Physical activity may affect the concentrations of circulating endogenous hormones in female athletes. Understanding the relationship between athletic and physical activity and circulating female hormone concentrations is critical. Objective: To test the hypotheses that (1) the estradiol-progesterone profile of high school adolescent girls participating in training, conditioning, and competition would differ from that of physically inactive, age-matched adolescent girls throughout a 3-month period; and (2) athletic training and conditioning would alter body composition (muscle, bone), leading to an increasingly greater lean–body-mass to fat–body-mass ratio with accompanying hormonal changes. Design: Cohort study. Settings: Laboratory and participants' homes. Patients or Other Participants: A total of 106 adolescent girls, ages 14–18 years, who had experienced at least 3 menstrual cycles in their lifetime. Main Outcome Measure(s): Participants were prospectively monitored throughout a 13-week period, with weekly physical activity assessments and 15 urine samples for estrogen, luteinizing hormone, creatinine, and progesterone concentrations. Each girl underwent body-composition measurements before and after the study period. Results: Seventy-four of the 98 girls (76%) who completed the study classified themselves as athletes. Body mass index, body mass, and fat measures remained stable, and 17 teenagers had no complete menstrual cycle during the observation period. Mean concentrations of log(estrogen/creatinine) were slightly greater in nonathletes who had cycles of <24 or >35 days. Mean log(progesterone/creatinine) concentrations in nonathletes were less in the first half and greater in the second half of the cycle, but the differences were not statistically significant. Conclusions: A moderate level of athletic or physical activity did not influence urine concentrations of estrogen, progesterone, or luteinizing hormones. However, none of the

  12. High concentration honey chitosan electrospun nanofibers: biocompatibility and antibacterial effects.

    PubMed

    Sarhan, Wessam A; Azzazy, Hassan M E

    2015-05-20

    Honey nanofibers represent an attractive formulation with unique medicinal and wound healing advantages. Nanofibers with honey concentrations of <10% were prepared, however, there is a need to prepare nanofibers with higher honey concentrations to increase the antibacterial and wound healing effects. In this work, chitosan and honey (H) were cospun with polyvinyl alcohol (P) allowing the fabrication of nanofibers with high honey concentrations up to 40% and high chitosan concentrations up to 5.5% of the total weight of the fibers using biocompatible solvents (1% acetic acid). The fabricated nanofibers were further chemically crosslinked, by exposure to glutaraldehyde vapor, and physically crosslinked by heating and freezing/thawing. The new HP-chitosan nanofibers showed pronounced antibacterial activity against Staphylococcus aureus but weak antibacterial activity against Escherichia coli. The developed HP-chitosan nanofibers revealed no cytotoxicity effects on cultured fibroblasts. In conclusion, biocompatible, antimicrobial crosslinked honey/polyvinyl alcohol/chitosan nanofibers were developed which hold potential as effective wound dressing. PMID:25817652

  13. Mechanisms for tolerance of very high tissue phosphorus concentrations in Ptilotus polystachyus.

    PubMed

    Aziz, Tariq; Lambers, Hans; Nicol, Dion; Ryan, Megan H

    2015-04-01

    Study of plants with unusual phosphorus (P) physiology may assist development of more P-efficient crops. Ptilotus polystachyus grows well at high P supply, when shoot P concentrations ([P]) may exceed 40 mg P g(-1) dry matter (DM). We explored the P physiology of P. polystachyus seedlings grown in nutrient solution with 0-5 mM P. In addition, young leaves and roots of soil-grown plants were used for cryo-scanning electron microscopy and X-ray microanalysis. No P-toxicity symptoms were observed, even at 5 mM P in solution. Shoot DM was similar at 0.1 and 1.0 mM P in solution, but was ∼14% lower at 2 and 5 mM P. At 1 mM P, [P] was 36, 18, 14 and 11 mg P g(-1) DM in mature leaves, young leaves, stems and roots, respectively. Leaf potassium, calcium and magnesium concentrations increased with increasing P supply. Leaf epidermal and palisade mesophyll cells had similar [P]. The root epidermis and most cortical cells had senesced, even in young roots. We conclude that preferential accumulation of P in mature leaves, accumulation of balancing cations and uniform distribution of P across leaf cell types allow P. polystachyus to tolerate very high leaf [P]. PMID:25258291

  14. Effect of high salt concentrations on water structure

    NASA Astrophysics Data System (ADS)

    Leberman, R.; Soper, A. K.

    1995-11-01

    THE characteristic tetrahedral structure of water is known to be disrupted by changes in pressure and temperature1-3. It has been suggested that ions in solution may have a similar perturbing effect4,5. Here we use neutron diffraction to compare the effects of applied pressure and high salt concentrations on the hydrogen-bonded network of water. We find that the ions induce a change in structure equivalent to the application of high pressures, and that the size of the effect is ion-specific. Ionic concentrations of a few moles per litre have equivalent pressures that can exceed a thousand atmospheres. We propose that these changes may be understood in terms of the partial molar volume of the ions, relative to those of water molecules. The equivalent induced pressure of a particular ion species is correlated with its efficacy in precipitating, or salting-out, proteins from solution6.

  15. High-efficiency GaAs concentrator space cells

    NASA Technical Reports Server (NTRS)

    Werthen, J. G.; Virshup, G. F.; Macmillan, H. F.; Ford, C. W.; Hamaker, H. C.

    1987-01-01

    High efficiency Al sub x Ga sub 1-x As/GaAs heteroface solar concentrator cells have been developed for space applications. The cells, which were grown using metalorganic chemical vapor deposition (MOCVD), have been fabricated in both the p-n and n-p configurations. Magnesium and zinc are used as the p-type dopants, and Se is used as the n-type dopant. The space cells, which are designed for use in a Cassegrainian concentrator operating at 100 suns, AMO, have a circular illuminated area 4 mm in diameter on a 5 mm by 5 mm cell. These cells have exhibited flash-tested efficiencies as high as 23.6 percent at 28 C and 21.6 percent at 80 C.

  16. Concentrations and environmental fate of Ra in cation-exchange regeneration brine waste disposed to septic tanks and accumulation in sludge, New Jersey Coastal Plain, USA

    USGS Publications Warehouse

    Szabo, Z.; Jacobsen, E.; Kraemer, T.F.; Parsa, B.

    2008-01-01

    Concentrations of Ra in liquid and solid wastes generated from 15 softeners treating domestic well waters from New Jersey Coastal Plain aquifers (where combined Ra (226Ra plus 228Ra) concentrations commonly exceed 0.185 Bq L-1) were determined. Softeners, when maintained, reduced combined Ra about 10-fold (<0.024 Bq L-1). Combined Ra exceeded 0.185 Bq L-1 at 1 non-maintained system. Combined Ra was enriched in regeneration brine waste (maximum, 81.2 Bq L-1), but concentrations in septic-tank effluents receiving brine waste were less than in the untreated ground waters. The maximum combined Ra concentration in aquifer sands (40.7 Bq kg-1 dry weight) was less than that in sludge from the septic tanks (range, 84-363 Bq kg-1), indicating Ra accumulation in sludge from effluent. The combined Ra concentration in sludge from the homeowners' septic systems falls within the range reported for sludge samples from publicly owned treatment works within the region.

  17. Quantitative Analysis of Uranium Accumulation on Sediments during Field-scale Biostimulation under Variable Bicarbonate Concentrations at the Rifle IFRC Site

    NASA Astrophysics Data System (ADS)

    Fox, P. M.; Davis, J. A.; Bargar, J.; Williams, K. H.; Singer, D. M.; Long, P.

    2011-12-01

    Bioremediation of uranium in subsurface environments is an approach that has been used at numerous field sites throughout the U.S in an attempt to lower dissolved U(VI) concentrations in groundwater. At the Rifle IFRC research site in Colorado, biostimulation of the native microbial population through acetate amendment for various periods of time has been tested in order to immobilize uranium through reduction U(VI) to U(IV). While this approach has successfully decreased U(VI) concentrations in the dissolved phase, often to levels below the EPA's maximum contaminant level of 0.13 μM, little work has examined the solid-phase accumulation of U during field-scale biostimulation. The lack of information on solid-phase U accumulation is due in large part to the difficulty of obtaining comparable pre- and post-biostimulation field sediment samples. In addition, the relatively low (<10 ppm) U concentrations present in most sediments preclude the use of spectroscopic techniques such as XAS for examining solid-phase U speciation. However, a recently developed technique of performing column experiments in situ has allowed us to overcome both of these problems, obtaining sediment samples which were exposed to the same biogeochemical conditions as subsurface sediments during the course of biostimulation. During the 2010 Rifle IFRC field experiment (dubbed "Super 8"), a number of in situ columns were deployed in various wells representing regions of the aquifer affected by acetate amendment (ambient bicarbonate) and concomitant acetate and bicarbonate amendment (elevated bicarbonate). Elevated levels of bicarbonate have been shown to cause desorption of U(VI) from the solid phase at the Rifle site under non-stimulated conditions, resulting in higher dissolved U(VI) concentrations in the aquifer. The Super 8 field experiment was designed in part to test the effect of elevated bicarbonate concentrations on U sequestration during biostimulation. Results from this experiment

  18. Ecologically relevant UV-B dose combined with high PAR intensity distinctly affect plant growth and accumulation of secondary metabolites in leaves of Centella asiatica L. Urban.

    PubMed

    Müller, Viola; Albert, Andreas; Barbro Winkler, J; Lankes, Christa; Noga, Georg; Hunsche, Mauricio

    2013-10-01

    We investigated the effects of environmentally relevant dose of ultraviolet (UV)-B and photosynthetic active radiation (PAR) on saponin accumulation in leaves on the example of Centella asiatica L. Urban. For this purpose, plants were exposed to one of four light regimes i.e., two PAR intensities with or without UV-B radiation. The experiment was conducted in technically complex sun simulators under almost natural irradiance and climatic conditions. As observed, UV-B radiation increased herb and leaf production as well as the content of epidermal flavonols, which was monitored by non-destructive fluorescence measurements. Specific fluorescence indices also indicate an increase in the content of anthocyanins under high PAR; this increase was likewise observed for the saponin concentrations. In contrast, UV-B radiation had no distinct effects on saponin and sapogenin concentrations. Our findings suggest that besides flavonoids, also saponins were accumulated under high PAR protecting the plant from oxidative damage. Furthermore, glycosylation of sapogenins seems to be important either for the protective function and/or for compartmentalization of the compounds. Moreover, our study revealed that younger leaves contain higher amounts of saponins, while in older leaves the sapogenins were the most abundant constituents. Concluding, our results proof that ambient dose of UV-B and high PAR intensity distinctly affect the accumulation of flavonoids and saponins, enabling the plant tissue to adapt to the light conditions. PMID:24044900

  19. Studying Interactions by Molecular Dynamics Simulations at High Concentration

    PubMed Central

    Fogolari, Federico; Corazza, Alessandra; Toppo, Stefano; Tosatto, Silvio C. E.; Viglino, Paolo; Ursini, Fulvio; Esposito, Gennaro

    2012-01-01

    Molecular dynamics simulations have been used to study molecular encounters and recognition. In recent works, simulations using high concentration of interacting molecules have been performed. In this paper, we consider the practical problems for setting up the simulation and to analyse the results of the simulation. The simulation of beta 2-microglobulin association and the simulation of the binding of hydrogen peroxide by glutathione peroxidase are provided as examples. PMID:22500085

  20. Production of highly concentrated, heat-stable hepatitis B surface antigen in maize.

    PubMed

    Hayden, Celine A; Egelkrout, Erin M; Moscoso, Alessa M; Enrique, Cristina; Keener, Todd K; Jimenez-Flores, Rafael; Wong, Jeffrey C; Howard, John A

    2012-10-01

    Plant-based oral vaccines are a promising emergent technology that could help alleviate disease burden worldwide by providing a low-cost, heat-stable, oral alternative to parenterally administered commercial vaccines. Here, we describe high-level accumulation of the hepatitis B surface antigen (HBsAg) at a mean concentration of 0.51%TSP in maize T1 seeds using an improved version of the globulin1 promoter. This concentration is more than fourfold higher than any previously reported lines. HBsAg expressed in maize seeds was extremely heat stable, tolerating temperatures up to 55 °C for 1 month without degradation. Optimal heat stability was achieved after oil extraction of ground maize material, either by supercritical fluid extraction or hexane treatment. The contributions of this material towards the development of a practical oral vaccine delivery system are discussed. PMID:22816734

  1. Synthesis of oligo- and polysaccharides by Lactobacillus reuteri 121 reuteransucrase at high concentrations of sucrose.

    PubMed

    Meng, Xiangfeng; Dobruchowska, Justyna M; Gerwig, Gerrit J; Kamerling, Johannis P; Dijkhuizen, Lubbert

    2015-09-23

    GTFA, a glucansucrase enzyme of the probiotic bacterium Lactobacillus reuteri 121, is capable of synthesizing an α-glucan polysaccharide with (1 → 4) and (1 → 6) linkages from sucrose. With respect to its biosynthesis, the present study has shown that the ratio of oligosaccharide versus polysaccharide synthesized was directly proportional to the concentration of sucrose. It appears that the size distribution of products is kinetically controlled, but the linkage distribution in the polysaccharide material is not changed. At high sucrose concentrations the sucrose isomers leucrose and trehalulose were synthesized, using the accumulated fructose as acceptor, together with 4'- and 6'-α-D-glucosyl-leucrose and 6'-α-D-glucosyl-trehalulose. The finding of an additional branched hexasaccharide demonstrates that the enzyme is able to introduce branch-points already in relatively short oligosaccharides. PMID:26281004

  2. Monitoring crop biochemical concentrations by high spectral remote sensing

    NASA Astrophysics Data System (ADS)

    Wang, Wen; Yan, Jing; Chen, Yonghua; Niu, Zheng; Wang, Changyao

    1999-12-01

    High spectral remote sensing is a hopeful technology in diagnosing crop nutrition background. With surface spectral measurement and laboratory biochemical analysis, the relationship between crop properties and spectral remote sensing data has been established. Seven chemical components - total chlorophyll, water crude protein, soluble sugar, N, P, K - were analyzed by laboratory chemical analyzing instrument. Foliar spectral property was detected outdoors by surface spectrometer. Chemical concentrations have been related to foliar spectral properties through stepwise multiple regression. The statistical equations between the chemical concentrations and reflectance as well as its several transformations were established. They underscored good estimation performance for chlorophyll, water crude protein, N and K with high squared multiple correlation coefficients (R2) values and high believable level. Especially R2 value of the equation between crude protein concentration and the first derivative of reflectance is 0.9564, which is the best result in the study of the fresh leave biochemistry up to now. On the basis of field experiment, an airborne remote sensing for crop nutrition monitoring was conducted in Shunyi County, Beijing, PR China. The sensor, made by Chinese Academy of Sciences, is in visible and near IR band. By image processing, the crop biochemistry map is obtained.

  3. Acclimation and toxicity of high ammonium concentrations to unicellular algae.

    PubMed

    Collos, Yves; Harrison, Paul J

    2014-03-15

    A literature review on the effects of high ammonium concentrations on the growth of 6 classes of microalgae suggests the following rankings. Mean optimal ammonium concentrations were 7600, 2500, 1400, 340, 260, 100 μM for Chlorophyceae, Cyanophyceae, Prymnesiophyceae, Diatomophyceae, Raphidophyceae, and Dinophyceae respectively and their tolerance to high toxic ammonium levels was 39,000, 13,000, 2300, 3600, 2500, 1200 μM respectively. Field ammonium concentrations <100 μM would not likely reduce the growth rate of most microalgae. Chlorophytes were significantly more tolerant to high ammonium than diatoms, prymnesiophytes, dinoflagellates, and raphidophytes. Cyanophytes were significantly more tolerant than dinoflagellates which were the least tolerant. A smaller but more complete data set was used to estimate ammonium EC₅₀ values, and the ranking was: Chlorophyceae>Cyanophyceae, Dinophyceae, Diatomophyceae, and Raphidophyceae. Ammonia toxicity is mainly attributed to NH₃ at pHs >9 and at pHs <8, toxicity is likely associated with the ammonium ion rather than ammonia. PMID:24533997

  4. Effects of high nitrogen concentrations on the growth of submersed macrophytes at moderate phosphorus concentrations.

    PubMed

    Yu, Qing; Wang, Hong-Zhu; Li, Yan; Shao, Jian-Chun; Liang, Xiao-Min; Jeppesen, Erik; Wang, Hai-Jun

    2015-10-15

    Eutrophication of lakes leading to loss of submersed macrophytes and higher turbidity is a worldwide phenomenon, attributed to excessive loading of phosphorus (P). However, recently, the role of nitrogen (N) for macrophyte recession has received increasing attention. Due to the close relationship between N and P loading, disentanglement of the specific effects of these two nutrients is often difficult, and some controversy still exists as to the effects of N. We studied the effects of N on submersed macrophytes represented by Vallisneria natans (Lour.) Hara in pots positioned at three depths (0.4 m, 0.8 m, and 1.2 m to form a gradient of underwater light conditions) in 10 large ponds having moderate concentrations of P (TP 0.03 ± 0.04 mg L(-1)) and five targeted concentrations of total nitrogen (TN) (0.5, 2, 10, 20, and 100 mg L(-1)), there were two ponds for each treatment. To study the potential shading effects of other primary producers, we also measured the biomass of phytoplankton (ChlaPhyt) and periphyton (ChlaPeri) expressed as chlorophyll a. We found that leaf length, leaf mass, and root length of macrophytes declined with increasing concentrations of TN and ammonium, while shoot number and root mass did not. All the measured growth indices of macrophytes declined significantly with ChlaPhyt, while none were significantly related to ChlaPeri. Neither ChlaPhyt nor ChlaPeri were, however, significantly negatively related to the various N concentrations. Our results indicate that shading by phytoplankton unrelated to the variation in N loading and perhaps toxic stress exerted by high nitrogen were responsible for the decline in macrophyte growth. PMID:26196308

  5. Highly concentrated active nonlinear media based on oxides

    SciTech Connect

    Bakin, D.V.; Dorozhkin, L.M.; Krasilov, Yu.I.; Kuznetsov, N.T.; Potemkin, A.V.; Tadzhi-Aglaev, K.S.; Shestakov, A.V.

    1987-07-01

    Important characteristics of highly concentrated active nonlinear media were studied which were based on oxide compounds of phosphates, niobates, tantalates, and titanates of neodymium with alkaline earth metals. Compounds of the indicated classes were synthesized and their spectral luminescent and nonlinear optical properties were studied. Single crystals were grown from the selected compounds (5-8mm) and preliminary measurements of the laser and nonlinear optical parameters were taken. Formulas are given for materials that demonstrated high nonlinear and luminescent properties simultaneously. Spectroscopic and nonlinear optical properties of some oxygen compounds of rare earth elements are shown.

  6. Accumulated metal speciation in earthworm populations with multigenerational exposure to metalliferous soils: cell fractionation and high-energy synchrotron analyses.

    PubMed

    Andre, Jane; Charnock, John; Stürzenbaum, Stephen R; Kille, Peter; Morgan, A John; Hodson, Mark E

    2009-09-01

    Predicting metal bioaccumulation and toxicity in soil organisms is complicated by site-specific biotic and abiotic parameters. In this study we exploited tissue fractionation and digestion techniques, combined with X-ray absorption spectroscopy (XAS), to investigate the whole-body and subcellular distributions, ligand affinities, and coordination chemistry of accumulated Pb and Zn in field populations of the epigeic earthworm Lumbricus rubellus inhabiting three contrasting metalliferous and two unpolluted soils. Our main findings were (i) earthworms were resident in soils with concentrations of Pb and Zn ranging from 1200 to 27,000 mg kg(-1) and 200 to 34,000 mg kg(-1), respectively; (ii) Pb and Zn primarily accumulated in the posterior alimentary canal in nonsoluble subcellular fractions of earthworms; (iii) site-specific differences in the tissue and subcellular partitioning profiles of populations were observed, with earthworms from a calcareous site partitioning proportionally more Pb to their anterior body segments and Zn to the chloragosome-rich subcellular fraction than their acidic-soil inhabiting counterparts; (iv) XAS indicated that the interpopulation differences in metal partitioning between organs were not accompanied by qualitative differences in ligand-binding speciation, because crystalline phosphate-containing pyromorphite was a predominant chemical species in the whole-worm tissues of all mine soil residents. Differences in metal (Pb, Zn) partitioning at both organ and cellular levels displayed by field populations with protracted histories of metal exposures may reflect theirinnate ecophysiological responses to essential edaphic variables, such as Ca2+ status. These observations are highly significant in the challenging exercise of interpreting holistic biomarker data delivered by "omic" technologies. PMID:19764255

  7. Using High Fluoride Concentration Products in Public Policy: A Rapid Review of Current Guidelines for High Fluoride Concentration Products.

    PubMed

    Douglas, Gail V A; Ramsdale, Martin P; Vinall-Collier, Karen; Csikar, Julia I

    2016-01-01

    Despite improvements in dental caries levels since the widespread introduction of fluoride toothpastes, it is still a disease which is considered to be a priority in many countries around the world. Individuals at higher risk of caries can be targeted with products with a high fluoride concentration to help reduce the amount and severity of the disease. This paper compares guidance from around the world on the use of products with a high fluoride concentration and gives examples of how guidance has been translated into activity in primary care dental practice. A rapid review of electronic databases was conducted to identify the volume and variation of guidance from national or professional bodies on the use of products with a high fluoride concentration. Fifteen guidelines published within the past 10 years and in English were identified and compared. The majority of these guidelines included recommendations for fluoride varnish use as well as for fluoride gels, while a smaller number offered guidance on high fluoride strength toothpaste and other vehicles. Whilst there was good consistency in recommendations for fluoride varnish in particular, there was sometimes a lack of detail in other areas of recommendation for other vehicles with a high fluoride concentration. There are good examples within the UK, such as the Childsmile project and Delivering Better Oral Health, which highlight that the provision of evidence-based guidance can be influential in directing scarce resources towards oral health improvements. Policy can be influenced by evidence-based national recommendations and used to help encourage dental professionals and commissioners and third-party payers to adopt higher levels of practices aimed at oral health improvement. PMID:27100106

  8. Wet oxidation of real coke wastewater containing high thiocyanate concentration.

    PubMed

    Oulego, Paula; Collado, Sergio; Garrido, Laura; Laca, Adriana; Rendueles, Manuel; Díaz, Mario

    2014-01-01

    Coke wastewaters, in particular those with high thiocyanate concentrations, represent an important environmental problem because of their very low biodegradability. In this work, the treatment by wet oxidation of real coke wastewaters containing concentrations of thiocyanate above 17 mM has been studied in a 1-L semi-batch reactor at temperatures between 453 and 493 K, with total oxygen pressures in the range of 2.0-8.0 MPa. A positive effect of the matrix of real coke wastewater was observed, resulting in faster thiocyanate degradation than was obtained with synthetic wastewaters. Besides, the effect of oxygen concentration and temperature on thiocyanate wet oxidation was more noticeable in real effluents than in synthetic wastewaters containing only thiocyanate. It was also observed that the degree of mineralization of the matrix organic compounds was higher when the initial thiocyanate concentration increased. Taking into account the experimental data, kinetic models were obtained, and a mechanism implying free radicals was proposed for thiocyanate oxidation in the matrix considered. In all cases, sulphate, carbonates and ammonium were identified as the main reaction products of thiocyanate wet oxidation. PMID:24269931

  9. Application of cyclic damage accumulation life prediction model to high temperature components

    NASA Technical Reports Server (NTRS)

    Nelson, Richard S.

    1989-01-01

    A high temperature, low cycle fatigue life prediction method was developed. This method, Cyclic Damage Accumulation (CDA), was developed for use in predicting the crack initiation lifetime of gas turbine engine materials, but it can be applied to other materials as well. The method is designed to account for the effects on creep-fatigue life of complex loading such as thermomechanical fatigue, hold periods, waveshapes, mean stresses, multiaxiality, cumulative damage, coatings, and environmental attack. Several features of this model were developed to make it practical for application to actual component analysis, such as the ability to handle nonisothermal loading (including TMF), arbitrary cycle paths, and multiple damage modes. The CDA life prediction model was derived from extensive specimen tests conducted on cast nickel-base superalloy B1900 + Hf. These included both monotonic tests (tensile and creep) and strain-controlled fatigue experiments (uniaxial, biaxial, TMF, mixed creep-fatigue, and controlled mean stress). Additional specimen tests were conducted on wrought INCO 718 to verify the applicability of the final CDA model to other high-temperature alloys. The model will be available to potential users in the near future in the form of a FORTRAN-77 computer program.

  10. Electromagnetically assisted synthesis of highly concentrated gold nanoparticle colloids

    NASA Astrophysics Data System (ADS)

    Hernandez, Laura; Rosas, Walter; Naranjo, Guillermo; Peralta, Xomalin G.; Vargas, Watson L.

    2015-03-01

    The synthesis of metallic nanoparticles is currently an extremely active area of research due to the multiple potential applications of nanomaterials to areas ranging from nano-medicine to catalysis. Some of the current challenges of nanoparticle synthesis protocols include synthesizing nanoparticles in high concentrations with a small polydispersity. The present study contrasts and compares the synthesis of highly concentrated colloidal gold using three different sources of electromagnetic radiation to assist the reaction. The first source was a Spectra Physics Mai Tai Ti:Sapphire laser made by Sperian, this laser generates 70 fs FWHM pulses with wavelengths in the range of 690-1040 nm. The second source was sun light; this was measured to have a power of 10W. The third source was a lowelDP lamp with a measured intensity of 25W. Both the solar light and the lamp's rays were concentrated using a 28cm x 28cm Fresnel lens. Results will be presented highlighting differences and similarities in size, shape, crystallinity and time of the reaction. We speculate about the role played by variations in wavelength, temporal profile of the electromagnetic source (pulsed vs. continuous), temperature of the reaction and excitation power in the final structure of the nanoparticles generated.

  11. Towards operating direct methanol fuel cells with highly concentrated fuel

    NASA Astrophysics Data System (ADS)

    Zhao, T. S.; Yang, W. W.; Chen, R.; Wu, Q. X.

    A significant advantage of direct methanol fuel cells (DMFCs) is the high specific energy of the liquid fuel, making it particularly suitable for portable and mobile applications. Nevertheless, conventional DMFCs have to be operated with excessively diluted methanol solutions to limit methanol crossover and the detrimental consequences. Operation with diluted methanol solutions significantly reduces the specific energy of the power pack and thereby prevents it from competing with advanced batteries. In view of this fact, there exists a need to improve conventional DMFC system designs, including membrane electrode assemblies and the subsystems for supplying/removing reactants/products, so that both the cell performance and the specific energy can be simultaneously maximized. This article provides a comprehensive review of past efforts on the optimization of DMFC systems that operate with concentrated methanol. Based on the discussion of the key issues associated with transport of the reactants/products, the strategies to manage the supply/removal of the reactants/products in DMFC operating with highly concentrated methanol are identified. With these strategies, the possible approaches to achieving the goal of concentrated fuel operation are then proposed. Past efforts in the management of the reactants/products for implementing each of the approaches are also summarized and reviewed.

  12. Optical design considerations for high-concentration photovoltaics

    NASA Astrophysics Data System (ADS)

    Garboushian, Vahan; Gordon, Robert

    2006-08-01

    Over the past 15 years, major advances in Concentrating Photovoltaics (CPV) have been achieved. Ultra-efficient Si solar cells have produced commercial concentration systems which are being fielded today and are competitively priced. Advanced research has primarily focused on significantly more efficient multi-junction solar cells for tomorrow's systems. This effort has produced sophisticated solar cells that significantly improve power production. Additional performance and cost improvements, especially in the optical system area and system integration, must be made before CPV can realize its ultimate commercial potential. Structural integrity and reliability are vital for commercial success. As incremental technical improvements are made in solar cell technologies, evaluation and 'fine-tuning' of optical systems properly matched to the solar cell are becoming increasingly necessary. As we move forward, it is increasingly important to optimize all of the interrelated elements of a CPV system for high performance without sacrificing the marketable cost and structural requirements of the system. Areas such as wavelength absorption of refractive optics need to be carefully matched to the solar cell technology employed. Reflective optics require advanced engineering models to insure uniform flux distribution without excessive losses. In Situ measurement of the 'fine-grain' improvements are difficult as multiple variables such as solar insolation, temperature, wind, altitude, etc. infringe on analytical data. This paper discusses design considerations based on 10 years of field trials of high concentration systems and their relevance for tomorrow's advanced CPV systems.

  13. Accumulation of intraepithelial mast cells with a unique protease phenotype in TH2-high asthma

    PubMed Central

    Dougherty, Ryan H.; Sidhu, Sukhvinder S.; Raman, Kavita; Solon, Margaret; Solberg, Owen D.; Caughey, George H.; Woodruff, Prescott G.; Fahy, John V.

    2010-01-01

    Background Previously, we found that mast cell tryptases and carboxypeptidase A3 (CPA3) are differentially expressed in the airway epithelium in asthmatic subjects. We also found that asthmatic subjects can be divided into 2 subgroups (“TH2 high” and “TH2 low” asthma) based on epithelial cell gene signatures for the activity of TH2 cytokines. Objectives We sought to characterize intraepithelial mast cells (IEMCs) in asthma. Methods We performed gene expression profiling in epithelial brushings and stereology-based quantification of mast cell numbers in endobronchial biopsy specimens from healthy control and asthmatic subjects before and after treatment with inhaled corticosteroids (ICSs). We also performed gene expression and protein quantification studies in cultured airway epithelial cells and mast cells. Results By means of unsupervised clustering, mast cell gene expression in the airway epithelium related closely to the expression of IL-13 signature genes. The levels of expression of mast cell genes correlate positively with lung function improvements with ICSs. IEMC density was 2-fold higher than normal in subjects with TH2-high asthma compared with that seen in subjects with TH2-low asthma or healthy control subjects (P = .015 for both comparisons), and these cells were characterized by expression of tryptases and CPA3 but not chymase. IL-13 induced expression of stem cell factor in cultured airway epithelial cells, and mast cells exposed to conditioned media from IL-13–activated epithelial cells showed downregulation of chymase but no change in tryptase or CPA3 expression. Conclusion IEMC numbers are increased in subjects with TH2-high asthma, have an unusual protease phenotype (tryptase and CPA3 high and chymase low), and predict responsiveness to ICSs. IL-13–stimulated production of stem cell factor by epithelial cells potentially explains mast cell accumulation in TH2-high asthmatic epithelium. PMID:20451039

  14. Concentration Response Curve for Ozone Realted Mortality at High Concentrations for presentation at International Society for Environmental Epidemiology

    EPA Science Inventory

    Concentration Response Curve for Ozone related Mortality at High Concentrations Ana G. Rappold, James Crooks, Lucas M. Neas Background Rising temperatures and decreased global circulation in the upcoming decades are expected to have a detrimental impact on air quality, particular...

  15. Symmetry-breaking phase-transitions in highly concentrated semen

    NASA Astrophysics Data System (ADS)

    Plouraboué, Franck; Creppy, Adama; Praud, Olivier; Druart, Xavier; Cazin, Sébastien; Yu, Hui; Degond, Pierre

    2015-11-01

    New experimental evidence of self-motion of a confined active suspension is presented. Depositing fresh semen sample in an annular shaped micro-fluidic chip leads to a spontaneous rotation motion of the fluid at sufficiently large sperm concentration. The rotation occurs unpredictably clockwise or counterclockwise and is robust and stable. Furthermore, for highly active and concentrated semen, richer dynamics can occur such as self-sustained or damped rotation oscillations. Experimental results obtained with systematic dilution provide a clear evidence of a phase transition toward collective motion associated with local alignment of spermatozoa akin to the Vicsek model. A macroscopic theory based on previously derived Self-Organized Hydrodynamics (SOH) models is adapted to this context and provides predictions consistent with the observed stationary motion.

  16. Further studies on the use of enzyme profiles to monitor residue accumulation in wildlife: Plasma enzymes in starlings fed graded concentrations of morsodren, DDE, Aroclor 1254, and malathion

    USGS Publications Warehouse

    Dieter, M.P.

    1975-01-01

    Wild-trapped starlings (Sturnus vulgaris) were fed concentrations of Morsodren (2, 4, and 8 ppm), DDE or Aroclor 1254 (5, 25, and 100 ppm), or malathion (8, 35, and 160 ppm) that were found to be sublethal in pen-reared Coturnix quail fed these amounts for 12 weeks. Plasma enzymes had to be measured earlier than planned in starlings fed Morsodren (at three weeks) or the organochlorine compounds (at seven weeks) because of unexpected, subsequent mortality. Variations in enzyme response were greater in wild than in pen-reared birds, but not enough to mask the toxicant-induced changes in enzyme activity. Cholinesterase activities decreased in birds fed Morsodren or malathion, and increased in those fed the organochlorine compounds. Lactate dehydrogenase activities increased two-fold in starlings fed Morsodren and two- to four-fold in those fed the organochlorine compounds, but only 50% in those fed malathion. Further examination of enzyme profiles showed that creatine kinase and aspartate aminotransferase activities increased two-to four-fold in birds fed Morsodren or the organochlorine compounds but not at all in those fed malathion. Thus the classes of environmental contaminants fed to starlings could be easily distinguished by these enzymatic parameters. Evaluation of enzymatic profiles appears to be a potentially valuable technique to monitor the presence of toxicants in wild populations, especially if used to complement standard chemical residue analyses. Here the residue analyses showed, after three weeks feeding, that mercury in the carcasses reflected the concentrations fed daily, whereas accumulation in the livers was two- to four-fold greater. After seven weeks feeding, liver residues of either organochlorine compound were about three-fold higher than the concentrations fed daily. However, four times as much DDE as Aroclor 1254 had accumulated in the carcasses.

  17. Ammonia concentrations in different size classes of ovarian follicles of sheep (Ovis aries): Possible mechanisms of accumulation and its effect on oocyte and granulosa cell growth in vitro.

    PubMed

    Nandi, S; Gupta, P S P; Mondal, S

    2016-03-01

    The present study investigated the concentrations and the mechanisms of accumulation of ammonia in different sizes of ovarian follicles and the effect of ammonia on oocyte and granulosa cell growth and functions in vitro with sheep (Ovis aries) as an animal model. The effects of cyclicity, seasonality, phases of the estrous cycle, and seasons (environmental) on ammonia concentrations in follicular fluid were also investigated. The effect of ammonia on in vitro development of oocytes (maturation rate, viability rate, cleavage rate, morulae/blastocysts yield) recovered from different sizes of follicles was examined at the levels of 0, 50, 100, 150, 250, 300, and 500 μM. Same concentrations of ammonia were examined on growth parameters (metabolic activity, viability, cell number increment, monolayer formation, apoptosis rate) and hormone (progesterone, estrogen) secretion activity of granulosa cells in vitro. Results suggested as the follicle size increased, ammonia concentrations decreased. The ammonia concentrations in ovine follicular fluid were found to be 261.5 ± 32.4, 157.7 ± 19.2, and 42.9 ± 8.3 μM, respectively, for small, medium, and large follicles. The corresponding ranges were 290 to 238 μM, 184 to 142 μM, and 70 to 22 μM. The differences were due to more accumulation of fluid, less metabolic activity of granulosa cells, and elevation of protein, potassium, and chloride as the follicle size increased. The seasonality and phases of the estrous cycle did not have any effect on ammonia level in ovarian follicles. Ammonia concentrations in all size classes of follicles examined were significantly reduced in ewes during hot seasons compared to cold seasons and in acyclic animals compared to cyclic ones. Ammonia impaired oocyte development at 300 μM when the oocytes were isolated from small follicles and at 250 μM when the oocytes were isolated from medium and large follicles. In contrast, ammonia caused the negative impact on granulosa cells growth

  18. Observations of a narrow zone of high suspended particulate matter (SPM) concentrations along the Dutch coast

    NASA Astrophysics Data System (ADS)

    van der Hout, Carola M.; Gerkema, Theo; Nauw, Janine J.; Ridderinkhof, Herman

    2015-03-01

    The objective of the study described in this paper is to localize the transport path of suspended particulate matter (SPM) in the Dutch coastal zone in the southern North Sea. It is known that a large mass of SPM is transported northward from the Strait of Dover, which is however mostly hidden from satellite and other surface measurements. The study area is located at 80 km north of the Rhine-Meuse estuary mouth in the far-field plume of the region of freshwater influence (ROFI). We investigate the occurrence and persistence of a turbidity maximum zone (TMZ) in an area closer to the coast than studied in previous observational programs. Shipboard measurements of vertical profiles of SPM concentrations, density and current velocities with a high cross-shore spatial resolution are presented. A turbidity maximum zone is found at a distance between 0.5 and 3 km from the coast along 30 km of the coastline. Observed concentrations are shown to vary strongly within a tidal cycle, and also between contrasting meteorological conditions in terms of the spring-neap tidal cycle, the significant wave height and the wind force. Temporary stratification is observed during spring tides, and occurs on the ebb phase of the tidal cycle. Cross-shore transports at a transect perpendicular to the coast show an accumulation of SPM in the TMZ within one tidal cycle. Possible mechanisms for this accumulation close to the coast are discussed.

  19. High-cell-density batch fermentation of Rhodococcus opacus PD630 using a high glucose concentration for triacylglycerol production.

    PubMed

    Kurosawa, Kazuhiko; Boccazzi, Paolo; de Almeida, Naomi M; Sinskey, Anthony J

    2010-06-01

    Biodiesel, monoalkyl esters of long-chain fatty acids with short-chain alcohols derived from triacylglycerols (TAGs), can be produced from renewable biomass sources. Recently, there has been interest in producing microbial oils from oleaginous microorganisms. Rhodococcus opacus PD630 is known to accumulate large amounts of TAGs. Following on these earlier works we demonstrate that R. opacus PD630 has the uncommon capacity to grow in defined media supplemented with glucose at a concentration of 300 g l(-1) during batch-culture fermentations. We found that we could significantly increase concentrations of both glucose and (NH4)2SO4 in the production medium resulting in a dramatic increase in fatty acid production when pH was controlled. We describe the experimental design protocol used to achieve the culture conditions necessary to obtain both high-cell-density and TAG accumulation; specifically, we describe the importance of the C/N ratio of the medium composition. Our bioprocess results demonstrate that R. opacus PD630 grown in batch-culture with an optimal production medium containing 240 g l(-1) glucose and 13.45 g l(-1) (NH4)2SO4 (C/N of 17.8) yields 77.6 g l(-1) of cell dry weight composed of approximately 38% TAGs indicating that this strain holds great potential as a future source of industrial biodiesel on starchy cellulosic feedstocks that are glucose polymers. PMID:20412824

  20. Status of concentrator collector and high-efficiency concentrator cell development

    SciTech Connect

    Gee, J.M.

    1990-01-01

    Photovoltaic concentrator collectors are an attractive option for utility-scale photovoltaic power plants. This paper reviews the current status of photovoltaic concentrator collector and cell development. Included in the review is a discussion of the economic motivation for concentrators, a summary of recent concentrator collector and cell development, and a description of a major new program to accelerate development and commercial introduction of concentrator collectors. 21 refs., 1 fig., 3 tabs.

  1. Accumulate Repeat Accumulate Coded Modulation

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative coded modulation scheme called 'Accumulate Repeat Accumulate Coded Modulation' (ARA coded modulation). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes that are combined with high level modulation. Thus at the decoder belief propagation can be used for iterative decoding of ARA coded modulation on a graph, provided a demapper transforms the received in-phase and quadrature samples to reliability of the bits.

  2. Effect of High Temperature on Albumin and Globulin Accumulation in the Endosperm Proteome of the Developing Wheat Grain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of high temperature during grain fill on the accumulation of KCl-soluble/methanol-insoluble albumins and globulins was investigated in the endosperm of developing wheat (Triticum aestivum, L. cv. Butte 86) grain. Plants were grown under a moderate (24°C/17°C, day/night) or a high temperat...

  3. High-Level Accumulation of Triacylglycerol and Starch in Photoautotrophically Grown Chlamydomonas debaryana NIES-2212.

    PubMed

    Toyoshima, Masakazu; Sato, Naoki

    2015-12-01

    Microalgae have the potential to produce triacylglycerol (TAG) and starch, which provide alternative sources of biofuel. A problem in using Chlamydomonas reinhardtii as a model for TAG production has been that this alga lacks phosphatidylcholine (PC), which is thought to be important for TAG synthesis in plants. We found that C. debaryana is one of the rare species of Chlamydomonas having PC. Here we show that this strain, grown under complete photoautotrophic conditions, accumulated TAG and starch up to 20 and 250 pg per cell, respectively, during the stationary phase without nutrient deprivation. Addition of nutrients in this state did not cause loss of TAG, which was found in dilution with fresh medium. The photosynthetically produced TAG contained a high level of monounsaturated fatty acids, which is a preferred property as a material for biodiesel. The oil bodies were present in the cytoplasm, either between the cytoplasmic membrane and the chloroplast or between the chloroplast and the nucleus, whereas the starch granules were present within the chloroplast. Oil bodies were also deposited as a broad layer in the peripheral space of the cytoplasm outside the chloroplast, and might be easily released from the cells by genetic, chemical or mechanical manipulation. These results suggest that C. debaryana is a promising seed organism for developing a good biofuel producer. PMID:26542110

  4. Monitoring of Wet Snow and Accumulations at High Alpine Glaciers Using Radar Technologies

    NASA Astrophysics Data System (ADS)

    Wendleder, A.; Heilig, A.; Schmitt, A.; Mayer, C.

    2015-04-01

    Conventional studies to assess the annual mass balance for glaciers rely on single point observations in combination with model and interpolation approaches. Just recently, airborne and spaceborne data is used to support such mass balance determinations. Here, we present an approach to map temporal changes of the snow cover in glaciated regions of Tyrol, Austria, using SAR-based satellite data. Two dual-polarized SAR images are acquired on 22 and 24 September 2014. As X and C-band reveal different backscattering properties of snow, both TerraSAR-X and RADARSAT-2 images are analysed and compared to ground truth data. Through application of filter functions and processing steps containing a Kennaugh decomposition, ortho-rectification, radiometric enhancement and normalization, we were able to distinguish between dry and wet parts of the snow surface. The analyses reveal that the wet-snow can be unambiguously classified by applying a threshold of -11 dB. Bare ice at the surface or a dry snowpack does not appear in radar data with such low backscatter values. From the temporal shift of wet-snow, a discrimination of accumulation areas on glaciers is possible for specific observation dates. Such data can reveal a periodic monitoring of glaciers with high spatial coverage independent from weather or glacier conditions.

  5. The Accumulative Effect of Concentric-Biased and Eccentric-Biased Exercise on Cardiorespiratory and Metabolic Responses to Subsequent Low-Intensity Exercise: A Preliminary Study

    PubMed Central

    Gavin, James Peter; Myers, Stephen; Willems, Mark Elisabeth Theodorus

    2015-01-01

    The study investigated the accumulative effect of concentric-biased and eccentric-biased exercise on cardiorespiratory, metabolic and neuromuscular responses to low-intensity exercise performed hours later. Fourteen young men cycled at low-intensity (~60 rpm at 50% maximal oxygen uptake) for 10 min before, and 12 h after: concentric-biased, single-leg cycling exercise (CON) (performed ~19:30 h) and eccentric-biased, double-leg knee extension exercise (ECC) (~06:30 h the following morning). Respiratory measures were sampled breath-by-breath, with oxidation values derived from stoichiometry equations. Knee extensor neuromuscular function was assessed before and after CON and ECC. Cardiorespiratory responses during low-intensity cycling were unchanged by accumulative CON and ECC. The RER was lower during low-intensity exercise 12 h after CON and ECC (0.88 ± 0.08), when compared to baseline (0.92 ± 0.09; p = 0.02). Fat oxidation increased from baseline (0.24 ± 0.2 g·min−1) to 12 h after CON and ECC (0.39 ± 0.2 g·min−1; p = 0.01). Carbohydrate oxidation decreased from baseline (1.59 ± 0.4 g·min−1) to 12 h after CON and ECC (1.36 ± 0.4 g·min−1; p = 0.03). These were accompanied by knee extensor force loss (right leg: −11.6%, p < 0.001; left leg: −10.6%, p = 0.02) and muscle soreness (right leg: 2.5 ± 0.9, p < 0.0001; left leg: 2.3 ± 1.2, p < 0.01). Subsequent concentric-biased and eccentric-biased exercise led to increased fat oxidation and decreased carbohydrate oxidation, without impairing cardiorespiration, during low-intensity cycling. An accumulation of fatiguing and damaging exercise increases fat utilisation during low intensity exercise performed as little as 12 h later. PMID:26839613

  6. Regulation of fruit ascorbic acid concentrations during ripening in high and low vitamin C tomato cultivars

    PubMed Central

    2012-01-01

    Background To gain insight into the regulation of fruit ascorbic acid (AsA) pool in tomatoes, a combination of metabolite analyses, non-labelled and radiolabelled substrate feeding experiments, enzyme activity measurements and gene expression studies were carried out in fruits of the ‘low-’ and ‘high-AsA’ tomato cultivars ‘Ailsa Craig’ and ‘Santorini’ respectively. Results The two cultivars exhibited different profiles of total AsA (totAsA, AsA + dehydroascorbate) and AsA accumulation during ripening, but both displayed a characteristic peak in concentrations at the breaker stage. Substrate feeding experiments demonstrated that the L-galactose pathway is the main AsA biosynthetic route in tomato fruits, but that substrates from alternative pathways can increase the AsA pool at specific developmental stages. In addition, we show that young fruits display a higher AsA biosynthetic capacity than mature ones, but this does not lead to higher AsA concentrations due to either enhanced rates of AsA breakdown (‘Ailsa Craig’) or decreased rates of AsA recycling (‘Santorini’), depending on the cultivar. In the later stages of ripening, differences in fruit totAsA-AsA concentrations of the two cultivars can be explained by differences in the rate of AsA recycling activities. Analysis of the expression of AsA metabolic genes showed that only the expression of one orthologue of GDP-L-galactose phosphorylase (SlGGP1), and of two monodehydroascorbate reductases (SlMDHAR1 and SlMDHAR3) correlated with the changes in fruit totAsA-AsA concentrations during fruit ripening in ‘Ailsa Craig’, and that only the expression of SlGGP1 was linked to the high AsA concentrations found in red ripe ‘Santorini’ fruits. Conclusions Results indicate that ‘Ailsa Craig’ and ‘Santorini’ use complementary mechanisms to maintain the fruit AsA pool. In the low-AsA cultivar (‘Ailsa Craig’), alternative routes of AsA biosynthesis may supplement biosynthesis via L

  7. High-brightness source based on luminescent concentration.

    PubMed

    de Boer, Dick K G; Bruls, Dominique; Jagt, Henri

    2016-07-11

    The concept of a high-luminance light source based on luminescent conversion of LED light and optical concentration in a transparent phosphor is explained. Experiments on a realized light source show that a luminous flux of 8500 lm and a luminance of 500 cd/mm2 can be attained using 56 pump LEDs at 330 W electrical input power. The measurement results are compared to optical simulations, showing that the experimental optical efficiency is slightly lower than expected. The present status enables applications like mid-segment digital projection using LED technology, whereas the concept is scalable to higher fluxes. PMID:27410894

  8. Particulate Matter Concentrations in East Oakland's High Street Corridor

    NASA Astrophysics Data System (ADS)

    Lei, P.; Jackson, J.; Lewis, R.; Marigny, A.; Mitchell, J. D.; Nguyen, R.; Philips, B.; Randle, D.; Romero, D.; Spears, D.; Telles, C.; Weissman, D.

    2012-12-01

    Particulate matter (PM) is a complex mixture of small solid pieces and/or liquid droplets in the air. High concentrations of PM can pose a serious health hazard because inhalation can result in breathing problems and/or aggravate asthma. Long term exposure can increase the likelihood of respiratory problems like asthma and emphysema as well as cancer. The smaller the particles, the deeper they can get into the respiratory system. For this reason, the smallest particles, those smaller than 2.5 micrometers in diameter (PM2.5), are the most dangerous. PM2.5 is largely emitted from motor vehicles burning fuels that don't break down fully. Our research team investigated the levels of PM2.5 as well as particles smaller than 10 micrometers (PM10) and total suspended particulate (TSP) along the northeast-southwest trending High Street Corridor, near Fremont High School in East Oakland, California. Using the Aerocet 531 mass particle counter, team members walked through neighborhoods and along major roads within a 1 mile radius of Fremont High School. The Aerocet 531 recorded two minute average measurements of all the relevant PM sizes, which are reported in mg/m3. Measurements were consistently taken in the morning, between 8:30 and 11:30 am. Preliminary results indicate maximum readings of all PM sizes at sites that are in close proximity to a major freeway (Interstate-880). These results support our initial hypothesis that proximity to major roads and freeways, especially those with high diesel-fuel burning truck traffic, would be the primary factor affecting PM concentration levels. Preliminary median and maximum readings all suggest particulate matter levels below what the EPA would consider unhealthy or risky.

  9. Potential accumulation of contaminated sediments in a reservoir of a high-Andean watershed: Morphodynamic connections with geochemical processes

    NASA Astrophysics Data System (ADS)

    Contreras, María. Teresa; Müllendorff, Daniel; Pastén, Pablo; Pizarro, Gonzalo E.; Paola, Chris; Escauriaza, Cristián.

    2015-05-01

    Rapid changes due to anthropic interventions in high-altitude environments, such as the Altiplano region in South America, require new approaches to understand the connections between physical and geochemical processes. Alterations of the water quality linked to the river morphology can affect the ecosystems and human development in the long term. The future construction of a reservoir in the Lluta River, located in northern Chile, will change the spatial distribution of arsenic-rich sediments, which can have significant effects on the lower parts of the watershed. In this investigation, we develop a coupled numerical model to predict and evaluate the interactions between morphodynamic changes in the Lluta reservoir, and conditions that can potentially desorb arsenic from the sediments. Assuming that contaminants are mobilized under anaerobic conditions, we calculate the oxygen concentration within the sediments to study the interactions of the delta progradation with the potential arsenic release. This work provides a framework for future studies aimed to analyze the complex connections between morphodynamics and water quality, when contaminant-rich sediments accumulate in a reservoir. The tool can also help to design effective risk management and remediation strategies in these extreme environments. This article was corrected on 15 JUNE 2015. See the end of the full text for details.

  10. SU-E-T-315: The Change of Optically Stimulated Luminescent Dosimeters (OSLDs) Sensitivity by Accumulated Dose and High Dose

    SciTech Connect

    Han, S; Jung, H; Kim, M; Ji, Y; Kim, K; Choi, S; Park, S; Yoo, H; Yi, C

    2014-06-01

    Purpose: The objective of this study is to evaluate radiation sensitivity of optical stimulated luminance dosimeters (OSLDs) by accumulated dose and high dose. Methods: This study was carried out in Co-60 unit (Theratron 780, AECL, and Canada) and used InLight MicroStar reader (Landauer, Inc., Glenwood, IL) for reading. We annealed for 30 min using optical annealing system which contained fluorescent lamps (Osram lumilux, 24 W, 280 ∼780 nm). To evaluate change of OSLDs sensitivity by repeated irradiation, the dosimeters were repeatedly irradiated with 1 Gy. And whenever a repeated irradiation, we evaluated OSLDs sensitivity. To evaluate OSLDs sensitivity after accumulated dose with 5 Gy, We irradiated dose accumulatively (from 1 Gy to 5 Gy) without annealing. And OSLDs was also irradiated with 15, 20, 30 Gy to certify change of OSLDs sensitivity after high dose irradiation. After annealing them, they were irradiated with 1Gy, repeatedly. Results: The OSLDs sensitivity increased up to 3% during irradiating seven times and decreased continuously above 8 times. That dropped by about 0.35 Gy per an irradiation. Finally, after 30 times irradiation, OSLDs sensitivity decreased by about 7%. For accumulated dose from 1 Gy to 5 Gy, OSLDs sensitivity about 1 Gy increased until 4.4% after second times accumulated dose compared with before that. OSLDs sensitivity about 1 Gy decreased by 1.6% in five times irradiation. When OSLDs were irradiated ten times with 1Gy after irradiating high dose (10, 15, 20 Gy), OSLDs sensitivity decreased until 6%, 9%, 12% compared with it before high dose irradiation, respectively. Conclusion: This study certified OSLDs sensitivity by accumulated dose and high dose. When irradiated with 1Gy, repeatedly, OSLDs sensitivity decreased linearly and the reduction rate of OSLDs sensitivity after high dose irradiation had dependence on irradiated dose.

  11. Unexpectedly high ultrafine aerosol concentrations above East Antarctic sea ice

    NASA Astrophysics Data System (ADS)

    Humphries, R. S.; Klekociuk, A. R.; Schofield, R.; Keywood, M.; Ward, J.; Wilson, S. R.

    2016-02-01

    Better characterisation of aerosol processes in pristine, natural environments, such as Antarctica, have recently been shown to lead to the largest reduction in uncertainties in our understanding of radiative forcing. Our understanding of aerosols in the Antarctic region is currently based on measurements that are often limited to boundary layer air masses at spatially sparse coastal and continental research stations, with only a handful of studies in the vast sea-ice region. In this paper, the first observational study of sub-micron aerosols in the East Antarctic sea ice region is presented. Measurements were conducted aboard the icebreaker Aurora Australis in spring 2012 and found that boundary layer condensation nuclei (CN3) concentrations exhibited a five-fold increase moving across the polar front, with mean polar cell concentrations of 1130 cm-3 - higher than any observed elsewhere in the Antarctic and Southern Ocean region. The absence of evidence for aerosol growth suggested that nucleation was unlikely to be local. Air parcel trajectories indicated significant influence from the free troposphere above the Antarctic continent, implicating this as the likely nucleation region for surface aerosol, a similar conclusion to previous Antarctic aerosol studies. The highest aerosol concentrations were found to correlate with low-pressure systems, suggesting that the passage of cyclones provided an accelerated pathway, delivering air masses quickly from the free troposphere to the surface. After descent from the Antarctic free troposphere, trajectories suggest that sea-ice boundary layer air masses travelled equatorward into the low-albedo Southern Ocean region, transporting with them emissions and these aerosol nuclei which, after growth, may potentially impact on the region's radiative balance. The high aerosol concentrations and their transport pathways described here, could help reduce the discrepancy currently present between simulations and observations of

  12. Molecular chaperone accumulation as a function of stress evidences adaptation to high hydrostatic pressure in the piezophilic archaeon Thermococcus barophilus

    PubMed Central

    Cario, Anaïs; Jebbar, Mohamed; Thiel, Axel; Kervarec, Nelly; Oger, Phil M.

    2016-01-01

    The accumulation of mannosyl-glycerate (MG), the salinity stress response osmolyte of Thermococcales, was investigated as a function of hydrostatic pressure in Thermococcus barophilus strain MP, a hyperthermophilic, piezophilic archaeon isolated from the Snake Pit site (MAR), which grows optimally at 40 MPa. Strain MP accumulated MG primarily in response to salinity stress, but in contrast to other Thermococcales, MG was also accumulated in response to thermal stress. MG accumulation peaked for combined stresses. The accumulation of MG was drastically increased under sub-optimal hydrostatic pressure conditions, demonstrating that low pressure is perceived as a stress in this piezophile, and that the proteome of T. barophilus is low-pressure sensitive. MG accumulation was strongly reduced under supra-optimal pressure conditions clearly demonstrating the structural adaptation of this proteome to high hydrostatic pressure. The lack of MG synthesis only slightly altered the growth characteristics of two different MG synthesis deletion mutants. No shift to other osmolytes was observed. Altogether our observations suggest that the salinity stress response in T. barophilus is not essential and may be under negative selective pressure, similarly to what has been observed for its thermal stress response. PMID:27378270

  13. Molecular chaperone accumulation as a function of stress evidences adaptation to high hydrostatic pressure in the piezophilic archaeon Thermococcus barophilus.

    PubMed

    Cario, Anaïs; Jebbar, Mohamed; Thiel, Axel; Kervarec, Nelly; Oger, Phil M

    2016-01-01

    The accumulation of mannosyl-glycerate (MG), the salinity stress response osmolyte of Thermococcales, was investigated as a function of hydrostatic pressure in Thermococcus barophilus strain MP, a hyperthermophilic, piezophilic archaeon isolated from the Snake Pit site (MAR), which grows optimally at 40 MPa. Strain MP accumulated MG primarily in response to salinity stress, but in contrast to other Thermococcales, MG was also accumulated in response to thermal stress. MG accumulation peaked for combined stresses. The accumulation of MG was drastically increased under sub-optimal hydrostatic pressure conditions, demonstrating that low pressure is perceived as a stress in this piezophile, and that the proteome of T. barophilus is low-pressure sensitive. MG accumulation was strongly reduced under supra-optimal pressure conditions clearly demonstrating the structural adaptation of this proteome to high hydrostatic pressure. The lack of MG synthesis only slightly altered the growth characteristics of two different MG synthesis deletion mutants. No shift to other osmolytes was observed. Altogether our observations suggest that the salinity stress response in T. barophilus is not essential and may be under negative selective pressure, similarly to what has been observed for its thermal stress response. PMID:27378270

  14. Nuclear accumulation of cyclin E/Cdk2 triggers a concentration-dependent switch for the destruction of p27Xic1

    PubMed Central

    Swanson, Craig; Ross, John; Jackson, Peter K.

    2000-01-01

    The action of cyclin-dependent kinases (CDKs) is regulated by phosphorylation, cyclin levels, the abundance of CDK inhibitors, and, as recently has been shown for cyclin B/cdc2, their localization. It is unclear how localization regulates the action of cyclin E/Cdk2 and its inhibitors. Here, we show that the closest known Xenopus laevis homolog of mammalian Cdk2 inhibitors p27Kip1 and p21CIP1, Xic1, is concentrated, ubiquitinated, and destroyed in the nucleus. Furthermore, Xic1 destruction requires nuclear import, but not nuclear export, and requires the formation of a transport-competent nuclear envelope, but not interactions between the lamina and chromatin. We show that (i) cyclin E/Cdk2 and Xic1 are transported into the nucleus as a complex and that Xic1 destruction requires the activity of cyclin E, (ii) that phosphorylation of Xic1 by cyclin E/Cdk2 bypasses the requirement for nuclear formation, and (iii) that the phosphorylation of Xic1 by cyclin E/Cdk2 is concentration dependent and likely realized through second-order interactions between stable cyclin E/Cdk2/Xic1 ternary complexes. Based on these results we propose a model wherein nuclear accumulation of the cyclin E/Cdk2/Xic1 complex triggers a concentration-dependent switch that promotes the phosphorylation of Xic1 and, consequently, its ubiquitination and destruction, thus allowing subsequent activation of cyclin E/Cdk2. PMID:10884410

  15. Convergent synthesis and in vivo inhibitory effect on fat accumulation of (-)-ternatin, a highly N-methylated cyclic peptide.

    PubMed

    Shimokawa, Kenichiro; Yamada, Kaoru; Kita, Masaki; Uemura, Daisuke

    2007-08-15

    (-)-Ternatin (1), a highly N-methylated cyclic heptapeptide, is a potent inhibitor of fat accumulation against 3T3-L1 murine adipocytes (EC50 = 0.14 microg/mL) [Shimokawa, K.; Mashima, I.; Asai, A.; Yamada, K.; Kita, M.; Uemura, D. Tetrahedron Lett. 2006, 47, 4445]. Compound 1 was synthesized from Boc-protected amino acids in solution. Upon treatment with 1 at 5 mg/kg/day, increases in body weight and fat accumulation in high-fat-fed mice were both significantly suppressed. PMID:17590333

  16. High manganese concentrations in rocks at Gale crater, Mars

    USGS Publications Warehouse

    Lanza, Nina L.; Fischer, Woodward W.; Wiens, Roger C.; Grotzinger, John; Ollila, Ann M.; Anderson, Ryan B.; Clark, Benton C.; Gellert, Ralf; Mangold, Nicolas; Maurice, Sylvestre; Le Mouélic, Stéphane; Nachon, Marion; Schmidt, Mariek E.; Berger, Jeffrey; Clegg, Samuel M.; Forni, Olivier; Hardgrove, Craig; Melikechi, Noureddine; Newsom, Horton E.; Sautter, Violaine

    2014-01-01

    The surface of Mars has long been considered a relatively oxidizing environment, an idea supported by the abundance of ferric iron phases observed there. However, compared to iron, manganese is sensitive only to high redox potential oxidants, and when concentrated in rocks, it provides a more specific redox indicator of aqueous environments. Observations from the ChemCam instrument on the Curiosity rover indicate abundances of manganese in and on some rock targets that are 1–2 orders of magnitude higher than previously observed on Mars, suggesting the presence of an as-yet unidentified manganese-rich phase. These results show that the Martian surface has at some point in time hosted much more highly oxidizing conditions than has previously been recognized.

  17. High intestinal lactase concentrations in adult Arbs in Saudi Arabia.

    PubMed

    Cook, G C; al-Torki, M T

    1975-07-19

    The maximum rise in blood glucose after 50 g lactose by mouth was determined in 40 adult Arabs. Out of 30 Bedouin, urban Saudi, and Yemeni and 9 of mixed ancestry (usually partly African), 25 (83%) and 2 (22%) respectively showed an increase of over 1-1 mmol/1 (20 mg/100 ml). In common with most northern Europeans and Hamitic people of northern Africa, Arabs in Saudi Arabia usually have high intestinal lactase concentrations in adult life. This persistence of high levels probably originated in the Arabian peninsula. Its selective advantage may have been associated with the fluid and calorie content of camels' milk, which is important for survival in desert nomads. PMID:1170003

  18. Shock initiation studies on high concentration hydrogen peroxide

    SciTech Connect

    Sheffield, Stephen A; Dattelbaum, Dana M; Stahl, David B; Gibson, L. Lee; Bartram, Brian D.

    2009-01-01

    Concentrated hydrogen peroxide (H{sub 2}O{sub 2}) has been known to detonate for many years. However, because of its reactivity and the difficulty in handling and confining it, along with the large critical diameter, few studies providing basic information about the initiation and detonation properties have been published. We are conducting a study to understand and quantify the initiation and detonation properties of highly concentrated H{sub 2}O{sub 2} using a gas-driven two-stage gun to produce well defined shock inputs. Multiple magnetic gauges are used to make in-situ measurements of the growth of reaction and subsequent detonation in the liquid. These experiments are designed to be one-dimensional to eliminate any difficulties that might be encountered with large critical diameters. Because of the concern of the reactivity of the H{sub 2}O{sub 2} with the confining materials, a remote loading system has been developed. The gun is pressurized, then the cell is filled and the experiment shot within less than three minutes. TV cameras are attached to the target so the cell filling can be monitored. Several experiments have been completed on {approx}98 wt % H{sub 2}O{sub 2}/H{sub 2}O mixtures; initiation has been observed in some experiments that shows homogeneous shock initiation behavior. The initial shock pressurizes and heats the mixture. After an induction time, a thermal explosion type reaction produces an evolving reactive wave that strengthens and eventually overdrives the first wave producing a detonation. From these measurements, we have determined unreacted Hugoniot information, times (distances) to detonation (Pop-plot points) that indicate low sensitivity, and detonation velocities of high concentration H{sub 2}O{sub 2}/H{sub 2}O solutions that agree with earlier estimates.

  19. Persistence and movement of phorate at high concentrations in soil.

    PubMed

    Singh, G; Singh, Z

    1984-12-01

    The entrance of a large number of chemicals into the agricultural market has caused concern to both cultivators and scientists because of their effectiveness at the target site, possibility of underground water contamination, and other undesirable effects such as phytotoxicity and effects on nontarget species. The persistence and movement of phorate--a systemic granular insecticide--were studied at high concentrations (4 and 8 kg a.i./ha) in field soil in two seasons, i.e., winter and summer. Periodic sampling for total phorate residues (TPR) at various vertical depths showed that it leached more efficiently at the higher dose (i.e., 8 kg a.i./ha) in both seasons. The horizontal mobility was also higher at this dose. Irrespective of the treatments, TPR leaching was significantly greater in winter with the higher dose, whereas its movement in the horizontal plane was comparatively greater in summer with this dose. The TPR concentration peaks remained stationary at 7.5 cm depth at all the redistribution times until the pesticide was nearly dissipated under both treatments and in both seasons. TPR persistence was higher at the higher dose. Its persistence was comparatively greater in winter than in summer. The present findings show that there seems to be no threat of underground water contamination by this pesticide even at a rate as high as 8 kg a.i./ha. PMID:6510326

  20. High-density carrier-accumulated and electrically stable oxide thin-film transistors from ion-gel gate dielectric.

    PubMed

    Fujii, Mami N; Ishikawa, Yasuaki; Miwa, Kazumoto; Okada, Hiromi; Uraoka, Yukiharu; Ono, Shimpei

    2015-01-01

    The use of indium-gallium-zinc oxide (IGZO) has paved the way for high-resolution uniform displays or integrated circuits with transparent and flexible devices. However, achieving highly reliable devices that use IGZO for low-temperature processes remains a technological challenge. We propose the use of IGZO thin-film transistors (TFTs) with an ionic-liquid gate dielectric in order to achieve high-density carrier-accumulated IGZO TFTs with high reliability, and we discuss a distinctive mechanism for the degradation of this organic-inorganic hybrid device under long-term electrical stress. Our results demonstrated that an ionic liquid or gel gate dielectric provides highly reliable and low-voltage operation with IGZO TFTs. Furthermore, high-density carrier accumulation helps improve the TFT characteristics and reliability, and it is highly relevant to the electronic phase control of oxide materials and the degradation mechanism for organic-inorganic hybrid devices. PMID:26677773

  1. High-density carrier-accumulated and electrically stable oxide thin-film transistors from ion-gel gate dielectric

    NASA Astrophysics Data System (ADS)

    Fujii, Mami N.; Ishikawa, Yasuaki; Miwa, Kazumoto; Okada, Hiromi; Uraoka, Yukiharu; Ono, Shimpei

    2015-12-01

    The use of indium-gallium-zinc oxide (IGZO) has paved the way for high-resolution uniform displays or integrated circuits with transparent and flexible devices. However, achieving highly reliable devices that use IGZO for low-temperature processes remains a technological challenge. We propose the use of IGZO thin-film transistors (TFTs) with an ionic-liquid gate dielectric in order to achieve high-density carrier-accumulated IGZO TFTs with high reliability, and we discuss a distinctive mechanism for the degradation of this organic-inorganic hybrid device under long-term electrical stress. Our results demonstrated that an ionic liquid or gel gate dielectric provides highly reliable and low-voltage operation with IGZO TFTs. Furthermore, high-density carrier accumulation helps improve the TFT characteristics and reliability, and it is highly relevant to the electronic phase control of oxide materials and the degradation mechanism for organic-inorganic hybrid devices.

  2. High-density carrier-accumulated and electrically stable oxide thin-film transistors from ion-gel gate dielectric

    PubMed Central

    Fujii, Mami N.; Ishikawa, Yasuaki; Miwa, Kazumoto; Okada, Hiromi; Uraoka, Yukiharu; Ono, Shimpei

    2015-01-01

    The use of indium–gallium–zinc oxide (IGZO) has paved the way for high-resolution uniform displays or integrated circuits with transparent and flexible devices. However, achieving highly reliable devices that use IGZO for low-temperature processes remains a technological challenge. We propose the use of IGZO thin-film transistors (TFTs) with an ionic-liquid gate dielectric in order to achieve high-density carrier-accumulated IGZO TFTs with high reliability, and we discuss a distinctive mechanism for the degradation of this organic–inorganic hybrid device under long-term electrical stress. Our results demonstrated that an ionic liquid or gel gate dielectric provides highly reliable and low-voltage operation with IGZO TFTs. Furthermore, high-density carrier accumulation helps improve the TFT characteristics and reliability, and it is highly relevant to the electronic phase control of oxide materials and the degradation mechanism for organic–inorganic hybrid devices. PMID:26677773

  3. Ionic Behavior in Highly Concentrated Aqueous Solutions Nanoconfined between Discretely Charged Silicon Surfaces.

    PubMed

    Qiu, Yinghua; Ma, Jian; Chen, Yunfei

    2016-05-17

    Through molecular dynamics simulations considering thermal vibration of surface atoms, ionic behaviors in concentrated NaCl solutions confined between discretely charged silicon surfaces have been investigated. The electric double layer structure was found to be sensitive to the density and distribution of surface charges. Due to the discreteness of the surface charge, a slight charge inversion appeared which depended on the surface charge density, bulk concentration, and confinement. In the nanoconfined NaCl solutions concentrated from 0.2 to 4.0 M, the locations of accumulation layers for Na(+) and Cl(-) ions remained stable, but their peak values increased. The higher the concentration was, the more obvious the charge inversion appeared. In 4.0 M NaCl solution, Na(+) and Cl(-) ions show obvious alternating layered distributions which may correspond to the solidification found in experiments. By changing surface separation, the confinement had a large effect on the ionic distribution. As both surfaces approached each other, many ions and water molecules were squeezed out of the confined space. Two adjacent layers in ion or water distribution profiles can be forced closer to each other and merge together. From ionic hydration analysis, the coordination number of Na(+) ions in highly confined space was much lower than that in the bulk. PMID:27137990

  4. High Concentration of Zinc in Sub-retinal Pigment Epithelial Deposits

    SciTech Connect

    Lengyel,I.; Flinn, J.; Peto, T.; Linkous, D.; Cano, K.; Bird, A.; Lanzirotti, A.; Frederickson, C.; van Kuijk, F.

    2007-01-01

    One of the hallmarks of age-related macular degeneration (AMD), the leading cause of blindness in the elderly in Western societies, is the accumulation of sub-retinal pigment epithelial deposits (sub-RPE deposits), including drusen and basal laminar deposits, in Bruch's membrane (BM). The nature and the underlying mechanisms of this deposit formation are not fully understood. Because we know that zinc contributes to deposit formation in neurodegenerative diseases, we tested the hypothesis that zinc might be involved in deposit formation in AMD. Using zinc specific fluorescent probes and microprobe synchrotron X-ray fluorescence we showed that sub-RPE deposits in post-mortem human tissues contain unexpectedly high concentrations of zinc, including abundant bio-available (ionic and/or loosely protein bound) ions. Zinc accumulation was especially high in the maculae of eyes with AMD. Internal deposit structures are especially enriched in bio-available zinc. Based on the evidence provided here we suggest that zinc plays a role in sub-RPE deposit formation in the aging human eye and possibly also in the development and/or progression of AMD.

  5. Source identification of high glyme concentrations in the Oder River.

    PubMed

    Stepien, D K; Püttmann, W

    2014-05-01

    The objective of the following study was to identify the source of high concentrations of glycol diethers (diglyme, triglyme, and tetraglyme) in the Oder River. Altogether four sampling campaigns were conducted and over 50 surface samples collected. During the first two samplings of the Oder River in the Oderbruch region (km 626-690), glymes were detected at concentrations reaching 0.065 μg L(-1) (diglyme), 0.54 μg L(-1) (triglyme) and 1.7 μg L(-1) (tetraglyme). The subsequent sampling of the Oder River, from the area close to the source to the Poland-Germany border (about 500 km) helped to identify the possible area of the dominating glyme entry into the river between km 310 and km 331. During that sampling, the maximum concentration of triglyme was 0.46 μg L(-1) and tetraglyme 2.2 μg L(-1); diglyme was not detected. The final sampling focused on the previously identified area of glyme entry, as well as on tributaries of the Oder River. Samples from Czarna Woda stream and Kaczawa River contained even higher concentrations of diglyme, triglyme, and tetraglyme, reaching 5.2 μg L(-1), 13 μg L(-1) and 81 μg L(-1), respectively. Finally, three water samples were analyzed from a wastewater treatment plant receiving influents from a Copper Smelter and Refinery; diglyme, triglyme, and tetraglyme were present at a maximum concentration of 1700 μg L(-1), 13,000 μg L(-1), and 190,000 μg L(-1), respectively. Further research helped to identify the source of glymes in the wastewater. The gas desulfurization process Solinox uses a mixture of glymes (Genosorb(®)1900) as a physical absorption medium to remove sulfur dioxide from off-gases from the power plant. The wastewater generated from the process and from the maintenance of the equipment is initially directed to the wastewater treatment plant where it undergoes mechanical and chemical treatment processes before being discharged to the tributaries of the Oder River. Although monoglyme was

  6. Design and development of a high-concentration and high-efficiency photovoltaic concentrator using a curved Fresnel lens

    SciTech Connect

    Scharlack, R.S.; Moffat, A.

    1983-08-01

    Thermo Electron has designed a high concentration photovoltaic module that uses a domed, point-focus Fresnel lens. Their design, design optimization process, and results from lens and receiver tests are described in this report. A complete module has not been fabricated and probably will not be fabricated in the future; however, Thermo Electron's optical design, analysis, and testing of both secondary optical units and domed Fresnel lenses have made a significant contribution to our project. Tooling errors prevented the lens from reaching its potential efficiency by the end of the contract, and resolution of these tooling problems is currently being attempted with a follow-on contract, No. 68-9463.

  7. High Fluoride Concentration Toothpastes for Children and Adolescents.

    PubMed

    Pretty, Iain A

    2016-01-01

    The purpose of this review is to present the available evidence to support the use of dentifrices with high (>1,500 ppm) concentrations of fluoride to help in the prevention and treatment of caries in high-risk children and adolescents. Recent evidence from high-quality systematic reviews supports the dose-response relationship between caries prevention and fluoride levels, and there is good evidence from randomised clinical trials to support the use of high fluoride dentifrices. Such products are typically prescribed oral pharmaceuticals that require thorough risk assessment by the clinician and restricting use in those less than 6 years old to cases where the risk of severe morbidity caused by caries is greater than that of aesthetically objectionable fluorosis and which should mitigate the risk of fluorosis. Further research is required on the use of population- or community-based interventions using such products and currently, the evidence for dentifrices containing more than 2,900 ppm is weaker than for those containing 2,800 ppm or less. PMID:27101304

  8. Dielectric Interface Effects on Surface Charge Accumulation and Collection towards High-Efficiency Organic Solar Cells

    NASA Astrophysics Data System (ADS)

    Hsiao, Yu-Che; Zang, Huidong; Ivanov, Ilia; Xu, Tao; Lu, Luyao; Yu, Luping; Hu, Bin

    2014-04-01

    This paper reports the experimental studies on the effects of dielectric thin-film on surface-charge accumulation and collection by using capacitance-voltage (C-V) measurements under photoexcitation. The dielectric thin-films with different surface polarizations are used with inverted device architecture based on the common photovoltaic PTB7:PC71BM film. In the C-V measurements, the peak-voltage shift with light intensity, namely, Vpeak shift, is particularly used to determine the surface-charge accumulation. We find that the Vpeak shows a smaller shift with light intensity when a higher surface polarization of dielectric thin-film is used. This means that a higher surface polarization of dielectric thin-film can decrease the surface-charge accumulation at electrode interface. However, a lower surface polarization of dielectric thin-film leads to a larger shift with light intensity. This implies that a lower surface polarization of dielectric thin-film corresponds to a larger surface-charge accumulation. This experimental finding indicates that dielectric thin-film plays an important role in the surface-charge accumulation and collection in the generation of photocurrent in organic solar cells. We demonstrate that the device performance can reach the power conversion efficiency of 8.7% when a higher dielectric PFN is used to enhance the surface-charge collection based on the inverted design of ITO/PFN/PTB7:PC71BM/MoO3/Ag.

  9. High upwind concentrations observed during an upslope tracer event

    SciTech Connect

    Ciolek, J.T. Jr.

    1993-10-01

    In February of 1991 the Rocky Flats Plant conducted twelve tracer experiments to validate an emergency response dispersion model known as the Terrain-Responsive Atmospheric Code (TRAC) (Hodgin 1985). Experimenters released 140 to 260 kilograms of inert tracer gas (sulfur hexafloride) from the plant over an 11 hour period. During each release, one hundred and sixty-five samples, most of which formed concentric rings of 8 and 16 km radius from the plant, recorded cumulative hourly concentrations of the tracer at one meter above ground level (AGL). Figure 1 contains a depiction of the sampler location, the terrain, and the meteorological stations available within the tracer study area. Brown (1991) describes the experimental setup in more detail. The subject of this paper is an event that occurred early in the fifth experiment, on February 9, 1991. In this experiment, tracer material released from 13:00 to 17:00 LST appeared both downwind and upwind of the source, with the highest concentrations upwind. During the fifth experiment, high pressure in Utah produced mostly sunny skis around Rocky Flats. For most of the day, one could find moderate (5 to 10 ms{sup {minus}1}) northerly (from the North) flow within the 700 to 500 mb level of the atmosphere (approximately 3000 to 5500 meters above Mean Sea Level (MSL)). Synoptic scale motions were isolated enough from the surface layer and heating was great enough to produce a 1 km deep upslope flow (flow from the East to the West) by late afternoon. The winds reversed and became downslope at approximately 17:30 LST.

  10. Bioconversion of High Concentrations of Hydrogen Sulfide to Elemental Sulfur in Airlift Bioreactor

    PubMed Central

    Abdel-Monaem Zytoon, Mohamed; Ahmad AlZahrani, Abdulraheem; Hamed Noweir, Madbuli; Ahmed El-Marakby, Fadia

    2014-01-01

    Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift bioreactor fed with high concentrations of H2S with special emphasis on the effect of pH in combination with other factors such as H2S loading rate, oxygen availability, and sulfide accumulation. H2S inlet concentrations between 1,008 ppm and 31,215 ppm were applied and elimination capacities up to 113 g H2S m−3 h−1 were achieved in the airlift bioreactor under investigation at a pH range 6.5–8.5. Acidic pH values reduced the elimination capacity. Elemental sulfur recovery up to 95% was achieved under oxygen limited conditions (DO < 0.2 mg/L) and at higher pH values. The sulfur oxidizing bacteria in the bioreactor tolerated accumulated dissolved sulfide concentrations >500 mg/L at pH values 8.0–8.5, and near 100% removal efficiency was achieved. Overall, the resident microorganisms in the studied airlift bioreactor favored pH values in the alkaline range. The bioreactor performance in terms of elimination capacity and sulfur recovery was better at pH range 8–8.5. PMID:25147857

  11. Low viscosity highly concentrated injectable nonaqueous suspensions of lysozyme microparticles.

    PubMed

    Miller, Maria A; Engstrom, Joshua D; Ludher, Baltej S; Johnston, Keith P

    2010-01-19

    Subcutaneous injection of concentrated protein and peptide solutions, in the range of 100-400 mg/mL, is often not possible with a 25- to 27-gauge needle, as the viscosity can be well above 50 cP. Apparent viscosities below this limit are reported for suspensions of milled lysozyme microparticles up to nearly 400 mg/mL in benzyl benzoate or benzyl benzoate mixtures with safflower oils through a syringe with a 25- to 27-gauge needle at room temperature. These apparent viscosities were confirmed using a cone-and-plate rheometer. The intrinsic viscosity regressed from the Kreiger-Dougherty model was only slightly above the Einstein value of 2.5, indicating the increase in viscosity relative to that of the solvent was caused primarily by the excluded volume. Thus, the increases in viscosity from electrical double layer interactions (electroviscous effects), solvation of the particles, or deviations of the particle shape from a spherical geometry were minimal, and much smaller than typically observed for proteins dissolved in aqueous solutions. The small electroviscous effects are expected given the negligible zeta potential and thin double layers in the low dielectric constant organic solvent. The suspensions were resuspendable after a year, with essentially constant particle size after two months as measured by static light scattering. The lower apparent viscosities for highly concentrated protein suspensions relative to protein solutions, coupled with these favorable characteristics upon resuspension, may offer novel opportunities for subcutaneous injection of therapeutic proteins. PMID:19803503

  12. High (500X) concentration PV array conceptual design

    SciTech Connect

    Levy, S.L.

    1984-05-01

    A conceptual design of a high concentration PV array using the Stanford/EPRI 500X silicon cell is presented. Work objectives were to identify an array concept with promise for economic viability, develop prelimiary component (subsystem) designs for such an array, and identify key component developmental issues. Design criterion was minimum levelized busbar energy cost, BBEC. New methodology developed permitted meaningful trade studies based on variation of subsystem costs and a 15 /kWh current year dollars target for BBEC. Subsystem designs include the tracking support structure and the PV module. The module includes the Fresnel lens parquet, the cell package, the backplate heat rejector and the module housing. Estimated cost for the array is in the range of allowed costs established by BBEC target and balance-of-system cost estimates. Key developmental issues are attaching the cell to the cell mount, thermal transients, and panel lifetime.

  13. Effect of High Temperature on Albumin and Globulin Accumulation in the Endosperm Proteome of the Developing Wheat Grain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of high temperature during grain fill on albumin and globulin accumulation profiles was investigated in the endosperm of developing wheat (Triticum aestivum, L. cv. Butte 86) grain. Albumins and globulins were isolated from endosperm of grain grown under a moderate (24°C/17°C, day/night) ...

  14. High temperature helical tubular receiver for concentrating solar power system

    NASA Astrophysics Data System (ADS)

    Hossain, Nazmul

    In the field of conventional cleaner power generation technology, concentrating solar power systems have introduced remarkable opportunity. In a solar power tower, solar energy concentrated by the heliostats at a single point produces very high temperature. Falling solid particles or heat transfer fluid passing through that high temperature region absorbs heat to generate electricity. Increasing the residence time will result in more heat gain and increase efficiency. A novel design of solar receiver for both fluid and solid particle is approached in this paper which can increase residence time resulting in higher temperature gain in one cycle compared to conventional receivers. The helical tubular solar receiver placed at the focused sunlight region meets the higher outlet temperature and efficiency. A vertical tubular receiver is modeled and analyzed for single phase flow with molten salt as heat transfer fluid and alloy625 as heat transfer material. The result is compared to a journal paper of similar numerical and experimental setup for validating our modeling. New types of helical tubular solar receivers are modeled and analyzed with heat transfer fluid turbulent flow in single phase, and granular particle and air plug flow in multiphase to observe the temperature rise in one cyclic operation. The Discrete Ordinate radiation model is used for numerical analysis with simulation software Ansys Fluent 15.0. The Eulerian granular multiphase model is used for multiphase flow. Applying the same modeling parameters and boundary conditions, the results of vertical and helical receivers are compared. With a helical receiver, higher temperature gain of heat transfer fluid is achieved in one cycle for both single phase and multiphase flow compared to the vertical receiver. Performance is also observed by varying dimension of helical receiver.

  15. Do high concentrations of microcystin prevent Daphnia control of phytoplankton?

    PubMed

    Chislock, Michael F; Sarnelle, Orlando; Jernigan, Lauren M; Wilson, Alan E

    2013-04-15

    Toxin-producing cyanobacteria have frequently been hypothesized to limit the ability of herbivorous zooplankton (such as Daphnia) to control phytoplankton biomass by inhibiting feeding, and in extreme cases, causing zooplankton mortality. Using limnocorral experiments in hyper-eutrophic ponds located in Alabama and Michigan (U.S.A.), we tested the hypothesis that high levels of cyanobacteria and microcystin, a class of hepatotoxins produced by several cyanobacterial genera, prevent Daphnia from strongly reducing phytoplankton abundance. At the start of the first experiment (Michigan), phytoplankton communities were dominated by toxic Microcystis and Anabaena (∼96% of total phytoplankton biomass), and concentrations of microcystin were ∼3 μg L⁻¹. Two weeks after adding Daphnia pulicaria from a nearby eutrophic lake, microcystin levels increased to ∼6.5 μg L⁻¹, yet Daphnia populations increased exponentially (r = 0.24 day⁻¹). By the third week, Daphnia had suppressed phytoplankton biomass by ∼74% relative to the no Daphnia controls and maintained reduced phytoplankton biomass until the conclusion of the five-week experiment. In the second experiment (Alabama), microcystin concentrations were greater than 100 μg L⁻¹, yet a mixture of three D. pulicaria clones from eutrophic lakes in southern MI increased and again reduced phytoplankton biomass, in this case by over 80%. The ability of Daphnia to increase in abundance and suppress phytoplankton biomass, despite high initial levels of cyanobacteria and microcystin, indicates that the latter does not prevent strong control of phytoplankton biomass by Daphnia genotypes that are adapted to environments with abundant cyanobacteria and associated cyanotoxins. PMID:23395484

  16. High throughput screens for the identification of compounds that alter the accumulation of the Alzheimer's amyloid beta peptide (Abeta).

    PubMed

    Haugabook, S J; Yager, D M; Eckman, E A; Golde, T E; Younkin, S G; Eckman, C B

    2001-07-30

    Evidence gathered over the last two decades suggests that beta amyloid (Abeta), the predominant proteinaceous component of senile plaques, plays an early and critical role in the etiology and pathogenesis of Alzheimer's disease (AD). Thus, it is reasonable to hypothesize that compounds capable of reducing the accumulation of Abeta may be of value therapeutically. Additionally, compounds that influence Abeta accumulation may be useful as tools to further dissect the cellular pathways that regulate Abeta production and accumulation. To screen for compounds that affect Abeta levels, we have established high throughput, cell-based assays capable of the sensitive and selective detection of Abeta40 in parallel with the more amyloidogenic form of the peptide, Abeta42. To validate the approach, we examined the effects of several compounds previously identified to influence Abeta accumulation. Analysis of peptide accumulation following treatment with these compounds showed results similar to those previously published. Currently, we are using this assay to screen drugs that have already received FDA approval for the treatment of other diseases and over-the-counter natural product extracts. If compounds such as these can be identified that lower Abeta in the brain, they may represent one of the fastest and most cost effective methods to therapy. PMID:11478976

  17. Identification of oleaginous yeast strains able to accumulate high intracellular lipids when cultivated in alkaline pretreated corn stover

    PubMed Central

    Sitepu, Irnayuli R.; Jin, Mingjie; Fernandez, J. Enrique; da Costa Sousa, Leonardo; Balan, Venkatesh; Boundy-Mills, Kyria L.

    2015-01-01

    Microbial oil is a potential alternative to food/plant-derived biodiesel fuel. Our previous screening studies identified a wide range of oleaginous yeast species, using a defined laboratory medium known to stimulate lipid accumulation. In this study, the ability of these yeasts to grow and accumulate lipids was further investigated in synthetic hydrolysate (SynH) and authentic ammonia fiber expansion (AFEX™)-pretreated corn stover hydrolysate (ACSH). Most yeast strains tested were able to accumulate lipids in SynH, but only a few were able to grow and accumulate lipids in ACSH medium. Cryptococcus humicola UCDFST 10-1004 was able to accumulate as high as 15.5 g/L lipids, out of a total of 36 g/L cellular biomass when grown in ACSH, with a cellular lipid content of 40% of cell dry weight. This lipid production is among the highest reported values for oleaginous yeasts grown in authentic hydrolysate. Pre-culturing in SynH media with xylose as sole carbon source enabled yeasts to assimilate both glucose and xylose more efficiently in the subsequent hydrolysate medium. This study demonstrates that ACSH is a suitable medium for certain oleaginous yeasts to convert lignocellullosic sugars to triacylglycerols for production of biodiesel and other valuable oleochemicals. PMID:25052467

  18. A high-quality carrot genome assembly provides new insights into carotenoid accumulation and asterid genome evolution.

    PubMed

    Iorizzo, Massimo; Ellison, Shelby; Senalik, Douglas; Zeng, Peng; Satapoomin, Pimchanok; Huang, Jiaying; Bowman, Megan; Iovene, Marina; Sanseverino, Walter; Cavagnaro, Pablo; Yildiz, Mehtap; Macko-Podgórni, Alicja; Moranska, Emilia; Grzebelus, Ewa; Grzebelus, Dariusz; Ashrafi, Hamid; Zheng, Zhijun; Cheng, Shifeng; Spooner, David; Van Deynze, Allen; Simon, Philipp

    2016-06-01

    We report a high-quality chromosome-scale assembly and analysis of the carrot (Daucus carota) genome, the first sequenced genome to include a comparative evolutionary analysis among members of the euasterid II clade. We characterized two new polyploidization events, both occurring after the divergence of carrot from members of the Asterales order, clarifying the evolutionary scenario before and after radiation of the two main asterid clades. Large- and small-scale lineage-specific duplications have contributed to the expansion of gene families, including those with roles in flowering time, defense response, flavor, and pigment accumulation. We identified a candidate gene, DCAR_032551, that conditions carotenoid accumulation (Y) in carrot taproot and is coexpressed with several isoprenoid biosynthetic genes. The primary mechanism regulating carotenoid accumulation in carrot taproot is not at the biosynthetic level. We hypothesize that DCAR_032551 regulates upstream photosystem development and functional processes, including photomorphogenesis and root de-etiolation. PMID:27158781

  19. High Rates of Species Accumulation in Animals with Bioluminescent Courtship Displays.

    PubMed

    Ellis, Emily A; Oakley, Todd H

    2016-07-25

    One of the great mysteries of evolutionary biology is why closely related lineages accumulate species at different rates. Theory predicts that populations undergoing strong sexual selection will more quickly differentiate because of increased potential for genetic isolation [1-6]. Whether or not these population genetic processes translate to more species at macroevolutionary scales remains contentious [7]. Here we show that lineages with bioluminescent courtship, almost certainly a sexually selected trait, have more species and faster rates of species accumulation than their non-luminous relatives. In each of ten distantly related animal lineages from insects, crustaceans, annelid worms, and fishes, we find more species in lineages with bioluminescent courtship compared to their sister groups. Furthermore, we find under a Yule model that lineages with bioluminescent courtship displays have significantly higher rates of species accumulation compared to a larger clade that includes them plus non-luminous relatives. In contrast, we do not find more species or higher rates in lineages that use bioluminescence for defense, a function presumably not under sexual selection. These results document an association between the origin of bioluminescent courtship and increased accumulation of species, supporting theory predicting sexual selection increases rates of speciation at macroevolutionary scales to influence global patterns of biodiversity. PMID:27345160

  20. Modelling acceptance of sunlight in high and low photovoltaic concentration

    SciTech Connect

    Leutz, Ralf

    2014-09-26

    A simple model incorporating linear radiation characteristics, along with the optical trains and geometrical concentration ratios of solar concentrators is presented with performance examples for optical trains of HCPV, LCPV and benchmark flat-plate PV.

  1. Diabetes accelerates smooth muscle accumulation in lesions of atherosclerosis: lack of direct growth-promoting effects of high glucose levels.

    PubMed

    Suzuki, L A; Poot, M; Gerrity, R G; Bornfeldt, K E

    2001-04-01

    In combination with other factors, hyperglycemia may cause the accelerated progression of atherosclerosis in people with diabetes. Arterial smooth muscle cell (SMC) proliferation and accumulation contribute to formation of advanced atherosclerotic lesions. Therefore, we investigated the effects of hyperglycemia on SMC proliferation and accumulation in vivo and in isolated arteries and SMCs by taking advantage of a new porcine model of diabetes-accelerated atherosclerosis, in which diabetic animals are hyperglycemic without receiving exogenous insulin. We show that diabetic animals fed a cholesterol-rich diet, like humans, develop severe lesions of atherosclerosis characterized by SMC accumulation and proliferation, whereas lesions in nondiabetic animals contain fewer SMCs after 20 weeks. However, high glucose (25 mmol/l) does not directly stimulate the proliferation of SMCs in isolated arterial tissue from diabetic or nondiabetic animals, or of cultured SMCs from these animals or from humans. Furthermore, the mitogenic actions of platelet-derived growth factor, IGF-I, or serum are not enhanced by high glucose. High glucose increases SMC glucose metabolism through the citric acid cycle and the pentose phosphate pathway by 240 and 90%, respectively, but <10% of consumed glucose is metabolized through these pathways. Instead, most of the consumed glucose is converted into lactate and secreted by the SMCs. Thus, diabetes markedly accelerates SMC proliferation and accumulation in atherosclerotic lesions. The stimulatory effect of diabetes on SMCs is likely to be mediated by effects secondary to the hyperglycemic state. PMID:11289052

  2. High Temperature Concentrated Solar Power Using Liquid Metal

    NASA Astrophysics Data System (ADS)

    Henry, Asegun

    One of the most attractive ways to try and reduce the cost of concentrated solar power (CSP) is to increase the system efficiency and the biggest loss in the system occurs in the conversion of heat to electricity via heat engine. Heat engines that utilize turbomachinery currently operate near their thermodynamic limitations and thus one of the only ways to improve heat engine efficiency is to increase the turbine inlet temperature. Significant effort is being devoted to the development of supercritical CO2 heat engines, but the most efficient heat engines are combined cycles, which reach efficiencies as high as 60%. However, such heat engines require turbine inlet temperatures ~1300-1500C, which is far beyond what is currently feasible with the state of the art molten salt infrastructure. In working towards the development of a system that can operate in the 1300-1500C temperature range, the most significant challenges lie in the materials and forming functional and reliable components out of new materials. One of the most attractive options from a cost and heat transfer perspective is to use liquid metals, such as tin and aluminum-silicon alloys along with a ceramic based infrastructure. This talk will overview ongoing efforts in the Atomistic Simulation and Energy (ASE) research group at Georgia Tech to develop prototype components such as an efficient high temperature cavity receiver, pumps and valves that can make a liquid metal based CSP infrastructure realizable.

  3. Spectral losses of high concentrator photovoltaic modules depending on latitude

    NASA Astrophysics Data System (ADS)

    Soria-Moya, Alberto; Fernández, Eduardo F.; Almonacid, Florencia; Mallick, Tapas K.

    2015-09-01

    High concentrator photovoltaic (HCPV) modules and systems are affected by changes on the incident solar spectrum. It is well known that among all the atmospheric parameters, the air mass has the largest impact on the spectral behavior of HCPV devices. The air mass can be considered as a geometrical parameter which depends entirely on the Sun's zenith angle (θ). Because of this, the yield of HCPV modules is affected by latitude. In this paper, a new method to estimate the gains/losses of energy due to the spectral impact has been introduced. Furthermore, the annual spectral losses depending on latitude have been calculated for several theoretical modules. For default values defined in the standard AM1.5d ASTM G-173-03 spectrum, results show that the spectral losses are almost independent of latitude for locations with low latitude values. Losses between 3% and 5% on the annual energy yield have been estimated for those areas. For high latitudes, the losses increase until they reach values between 10% and 14%. Results depend on the multi-junction solar cells and optical devices of the HCPV module considered.

  4. High-performance deployable structures for the support of high-concentration ratio solar array modules

    NASA Technical Reports Server (NTRS)

    Mobrem, M.

    1985-01-01

    A study conducted on high-performance deployable structures for the support of high-concentration ratio solar array modules is discussed. Serious consideration is being given to the use of high-concentration ratio solar array modules or applications such as space stations. These concentrator solar array designs offer the potential of reduced cost, reduced electrical complexity, higher power per unit area, and improved survivability. Arrays of concentrators, such as the miniaturized Cassegrainian concentrator modules, present a serious challenge to the structural design because their mass per unit area (5.7 kg/square meters) is higher than that of flexible solar array blankets, and the requirement for accurate orientation towards the Sun (plus or minus 0.5 degree) requires structures with improved accuracy potentials. In addition, use on a space station requires relatively high structural natural frequencies to avoid deleterious interactions with control systems and other large structural components. The objective here is to identify and evaluate conceptual designs of structures suitable for deploying and accurately supporting high-concentration ratio solar array modules.

  5. Accumulation of copper in the kidney of pigs fed high dietary zinc is due to metallothionein expression with minor effects on genes involved in copper metabolism.

    PubMed

    Zetzsche, A; Schunter, N; Zentek, J; Pieper, R

    2016-05-01

    A study was conducted to determine the effect of high dietary zinc (Zn) oxide on trace element accumulation in various organs with special emphasis on the kidney. A total of 40 weaned piglets were allocated into two groups with 16 and 24 piglets each receiving a diet containing normal (NZn; 100mg Zn/kg) or high (HZn; 2,100mg Zn/kg) Zn concentration, respectively. After two weeks, eight piglets from each treatment were killed and organ samples were taken. Eight piglets from the remaining 16 pigs fed HZn diets were changed to NZn diets (CZn). All remaining piglets were killed after another two weeks for organ sampling. Trace element concentration was determined in the jejunum, liver, kidney, pancreas, bone (metacarpal IV), spleen, lung, thymus, tonsils and lymph nodes of jejunum, ileum and colon. Kidney mRNA expression of Zn transporter ZnT1 and ZIP4, genes involved in Cu metabolism (Ctr1, Atox1, SOD1, ATP7A, CCS, CP) and divalent metal ion transport (DMT1) and binding (MT-1a, MT-2b, MT-3) were determined. The Zn concentration in jejunum, liver, pancreas tissue and metacarpal IV was higher (P<0.05) in HZn group compared with NZn and CZn groups. Trace element concentration in organs of CZn pigs was similar to those fed NZn diets. Zn concentration in muscle, lung and lymphatic organs as thymus, tonsils, spleen and lymph nodes of jejunum, ileum and colon did not differ between the groups. Zn and Cu were positively correlated (R=0.67; P<0.05) in the kidney. No significant differences for Cu chaperones, Cu transporters and Cu-dependent factors were determined despite decreased expression of Atox1 after two weeks and increased Ctr1 expression over time in the HZn group. Expression of MT-1a, MT-2b and MT-3 were significantly higher in HZn fed pigs with most pronounced effects for MT-1a > MT-2b > MT-3. Gene expression of MTs in pigs fed CZn diets did not differ from pigs fed NZn diets. The data suggest that high dietary Zn feeding in pigs leads to Cu co-accumulation in the

  6. Root based responses account for Psidium guajava survival at high nickel concentration.

    PubMed

    Bazihizina, Nadia; Redwan, Mirvat; Taiti, Cosimo; Giordano, Cristiana; Monetti, Emanuela; Masi, Elisa; Azzarello, Elisa; Mancuso, Stefano

    2015-02-01

    The presence of Psidium guajava in polluted environments has been reported in recent studies, suggesting that this species has a high tolerance to the metal stress. The present study aims at a physiological characterization of P. guajava response to high nickel (Ni) concentrations in the root-zone. Three hydroponic experiments were carried out to characterize the effects of toxic Ni concentrations on morphological and physiological parameters of P. guajava, focusing on Ni-induced damages at the root-level and root ion fluxes. With up to 300μM NiSO4 in the root-zone, plant growth was similar to that in control plants, whereas at concentrations higher than 1000μM NiSO4 there was a progressive decline in plant growth and leaf gas exchange parameters; this occurred despite, at all considered concentrations, plants limited Ni(2+) translocation to the shoot, therefore avoiding shoot Ni(2+) toxicity symptoms. Maintenance of plant growth with 300μM Ni(2+) was associated with the ability to retain K(+) in the roots meanwhile 1000 and 3000μM NiSO4 led to substantial K(+) losses. In this study, root responses mirror all plant performances suggesting a direct link between root functionality and Ni(2+) tolerance mechanisms and plant survival. Considering that Ni was mainly accumulated in the root system, the potential use of P. guajava for Ni(2+) phytoextraction in metal-polluted soils is limited; nevertheless, the observed physiological changes indicate a good Ni(2+) tolerance up to 300μM NiSO4 suggesting a potential role for the phytostabilization of polluted soils. PMID:25462976

  7. High-field penning-malmberg trap: confinement properties and use in positron accumulation

    SciTech Connect

    Hartley, J.H.

    1997-09-01

    This dissertation reports on the development of the 60 kG cryogenic positron trap at Lawrence Livermore National Laboratory, and compares the trap`s confinement properties with other nonneutral plasma devices. The device is designed for the accumulation of up to 2{times}10{sup 9} positrons from a linear-accelerator source. This positron plasma could then be used in Bhabha scattering experiments. Initial efforts at time-of-flight accumulation of positrons from the accelerator show rapid ({approximately}100 ms) deconfinement, inconsistent with the long electron lifetimes. Several possible deconfinement mechanisms have been explored, including annihilation on residual gas, injection heating, rf noise from the accelerator, magnet field curvature, and stray fields. Detailed studies of electron confinement demonstrate that the empirical scaling law used to design the trap cannot be extrapolated into the parameter regime of this device. Several possible methods for overcoming these limitations are presented.

  8. Transverse Emittance Growth in the Fermilab Antiproton Accumulator with High-Current Antiproton Stacks

    SciTech Connect

    Werkema, Steven J.; Peterson, David W.; Zhou, Ping

    1992-01-01

    Transverse emittance growth due to coherent instabilities in the Fermilab antiproton accumulator imposes a limit on the number of antiprotons which can be stacked and subsequently transferred to the collider. Consequences, the diagnosis and control of these phenomena has been required to further increase the luminosity of the collider. In this paper they present an overview of the techniques by which these instabilities have been studied and the methods by which they are controlled.

  9. Plastic litter accumulation on high-water strandline of urban beaches in Mumbai, India.

    PubMed

    Jayasiri, H B; Purushothaman, C S; Vennila, A

    2013-09-01

    Today, almost every beach on every coastline is threatened by human activities. The inadequate recycling and poor management of waste in developing countries has resulted in considerable quantities of plastic contaminating beaches. Though India has long coastline of 5,420 km along the mainland with 43 % of sandy beaches, data on litter accumulation, particularly the plastics, which are one of the most common and persistent pollutants in marine environment, are scanty. The abundance and distribution of plastic litter was quantitatively assessed in four sandy beaches in Mumbai, India, bimonthly from May 2011 to March 2012. Triplicates of 2 × 2 m (4 m(2)) quadrats were sampled in each beach with a total of 72 quadrats. Overall, average abundance of 11.6 items m(-2) (0.25-282.5 items m(-2)) and 3.24 g m(-2) (0.27-15.53 g m(-2)) plastic litter was recorded in Mumbai beaches. Plastic litter accumulation significantly varied temporally and spatially at p = 0.05. Significantly higher plastic litter accumulation was recorded in Juhu beach. Furthermore, the highest abundance by weight was recorded in November and May numerically. More than 80 % of plastic particles were within the size range of 5-100 mm both by number and weight. Moreover, coloured plastics were predominant with 67 % by number of items and 51 % by weight. Probably, the intense use of beaches for recreation, tourism, and religious activities has increased the potential for plastic contamination in urban beaches in Mumbai. PMID:23430068

  10. Response of nitrite accumulation and microbial community to free ammonia and dissolved oxygen treatment of high ammonium wastewater.

    PubMed

    Sui, Qianwen; Liu, Chong; Zhang, Junya; Dong, Hongmin; Zhu, Zhiping; Wang, Yi

    2016-05-01

    The effects of free ammonia (FA) and dissolved oxygen (DO) on nitrite accumulation in the treatment of high ammonium wastewater and on the evolution of the microbial community were investigated. Under high DO conditions (3.75 ± 0.49 mg/L), FA as high as 10.61 ± 2.89 mg NH3/L maintained stable nitrite accumulation rate (NAR) of 84 % with NH4 (+)-N load of 2.05 kg N/(m(3) day) at sludge retention time (SRT) of 15-18 days. After 56 days of operation, Proteobacteria and Nitrosomonas were the dominant phylum and genus, respectively; Nitrosomonas increased from 21.14 to 54.57 %. By contrast, under relative low DO and low FA, nitrite-oxidizing bacteria (NOB) were nearly eliminated (NOB/AOB of 0; ammonium-oxidizing bacteria (AOB)), and NAR of 94 % was achieved with lower NH4 (+)-N load of 0.48 kg N/(m(3) day). DO correlated with AOB and NOB abundance, and FA decreased NOB activity and the NOB/AOB ratio. In conclusion, high FA and high DO conditions are optimal for efficient nitrite accumulation. PMID:26743659

  11. Carbon Nanofibers Modified Graphite Felt for High Performance Anode in High Substrate Concentration Microbial Fuel Cells

    PubMed Central

    Shen, Youliang; Zhou, Yan; Chen, Shuiliang; Yang, Fangfang; Zheng, Suqi; Hou, Haoqing

    2014-01-01

    Carbon nanofibers modified graphite fibers (CNFs/GF) composite electrode was prepared for anode in high substrate concentration microbial fuel cells. Electrochemical tests showed that the CNFs/GF anode generated a peak current density of 2.42 mA cm−2 at a low acetate concentration of 20 mM, which was 54% higher than that from bare GF. Increase of the acetate concentration to 80 mM, in which the peak current density of the CNFs/GF anode greatly increased and was up to 3.57 mA cm−2, was seven times as that of GF anode. Morphology characterization revealed that the biofilms in the CNFs/GF anode were much denser than those in the bare GF. This result revealed that the nanostructure in the anode not only enhanced current generation but also could tolerate high substrate concentration. PMID:24883348

  12. Thermodynamic stability of high phosphorus concentration in silicon nanostructures

    NASA Astrophysics Data System (ADS)

    Perego, Michele; Seguini, Gabriele; Arduca, Elisa; Frascaroli, Jacopo; de Salvador, Davide; Mastromatteo, Massimo; Carnera, Alberto; Nicotra, Giuseppe; Scuderi, Mario; Spinella, Corrado; Impellizzeri, Giuliana; Lenardi, Cristina; Napolitani, Enrico

    2015-08-01

    Doping of Si nanocrystals (NCs) has been the subject of a strong experimental and theoretical debate for more than a decade. A major difficulty in the understanding of dopant incorporation at the nanoscale is related to the fact that theoretical calculations usually refer to thermodynamic equilibrium conditions, whereas, from the experimental point of view, impurity incorporation is commonly performed during NC formation. This latter circumstance makes impossible to experimentally decouple equilibrium properties from kinetic effects. In this report, we approach the problem by introducing the dopants into the Si NCs, from a spatially separated dopant source. We induce a P diffusion flux to interact with the already-formed and stable Si NCs embedded in SiO2, maintaining the system very close to the thermodynamic equilibrium. Combining advanced material synthesis, multi-technique experimental quantification and simulations of diffusion profiles with a rate-equation model, we demonstrate that a high P concentration (above the P solid solubility in bulk Si) within Si NCs embedded in a SiO2 matrix corresponds to an equilibrium property of the system. Trapping within the Si NCs embedded in a SiO2 matrix is essentially diffusion limited with no additional energy barrier, whereas de-trapping is prevented by a binding energy of 0.9 eV, in excellent agreement with recent theoretical findings that highlighted the impact of different surface terminations (H- or O-terminated NCs) on the stability of the incorporated P atoms.

  13. Cylindrically symmetric Fresnel lens for high concentration photovoltaic

    NASA Astrophysics Data System (ADS)

    Hung, Yu-Ting; Su, Guo-Dung

    2009-08-01

    High concentration photovoltaic (HCPV) utilizes point-focus cost-effective plastic Fresnel lens. And a millimeter-sized Ill-V compound multi-junction solar cell is placed underneath focusing optics which can achieve cell efficiency potential of up to 40.7 %. The advantage of HCPV makes less solar cell area and higher efficiency; however, the acceptance angle of HCPV is about +/-1°, which is very small and the mechanical tracking of the sun is necessary. In order to reduce the power consumption and the angle tracking error of tracking systems, a light collector model with larger acceptance angle is designed with ZEMAX®. In this model, the original radially symmetric Fresnel lens of HCPV is replaced by cylindrically symmetric Fresnel lens and a parabolic reflective surface. Light is collected in two dimensions separately. And a couple of lenses and a light pipe are added before the solar cell chip in order to collect more light when sun light deviates from incident angle of 00. An acceptance angle of +/-10° is achieved with GCR 400.

  14. High resolution imaging of intracellular oxygen concentration by phosphorescence lifetime

    PubMed Central

    Kurokawa, Hiromi; Ito, Hidehiro; Inoue, Mai; Tabata, Kenji; Sato, Yoshifumi; Yamagata, Kazuya; Kizaka-Kondoh, Shinae; Kadonosono, Tetsuya; Yano, Shigenobu; Inoue, Masahiro; Kamachi, Toshiaki

    2015-01-01

    Optical methods using phosphorescence quenching by oxygen are suitable for sequential monitoring and non-invasive measurements for oxygen concentration (OC) imaging within cells. Phosphorescence intensity measurement is widely used with phosphorescent dyes. These dyes are ubiquitously but heterogeneously distributed inside the whole cell. The distribution of phosphorescent dye is a major disadvantage in phosphorescence intensity measurement. We established OC imaging system for a single cell using phosphorescence lifetime and a laser scanning confocal microscope. This system had improved spatial resolution and reduced the measurement time with the high repetition rate of the laser. By the combination of ubiquitously distributed phosphorescent dye with this lifetime imaging microscope, we can visualize the OC inside the whole cell and spheroid. This system uses reversible phosphorescence quenching by oxygen, so it can measure successive OC changes from normoxia to anoxia. Lower regions of OC inside the cell colocalized with mitochondria. The time-dependent OC change in an insulin-producing cell line MIN6 by the glucose stimulation was successfully visualized. Assessing the detailed distribution and dynamics of OC inside cells achieved by the presented system will be useful to understanding a physiological and pathological oxygen metabolism. PMID:26065366

  15. Denitrification of high nitrate concentration wastewater using alternative carbon sources.

    PubMed

    Fernández-Nava, Y; Marañón, E; Soons, J; Castrillón, L

    2010-01-15

    The use of different organic carbon sources in the denitrification of wastewater containing 2500 mg nitrates/L in a SBR was studied. Three alternative sources of carbon were tested: wastewater from a sweet factory, a residue from a soft drinks factory and a residue from a dairy plant. The first two are sugar-rich, whereas the third presents a high content in lactic acid. Maximum specific denitrification rates of between 42 and 48 mg NO(3)-N/g VSS h were obtained. The effluents were nitrate-free and very low COD concentrations were obtained in 4-6h reaction time, especially with the sugar-rich carbon sources. The values of the denitrifier net yield coefficient were higher than when using methanol (0.93-1.75 g VSS(formed)/g NO(x)-N(reduced)). The lowest value was obtained using the lactic acid-rich residue. The optimum COD/N ratios varied between 4.6 for the lactic acid-rich carbon source and 5.5-6.5 for the sugar-rich carbon sources. PMID:19782470

  16. High organochlorine accumulation in blubber of Guiana dolphin, Sotalia guianensis, from Brazilian coast and its use to establish geographical differences among populations.

    PubMed

    Lailson-Brito, J; Dorneles, P R; Azevedo-Silva, C E; Azevedo, A F; Vidal, L G; Zanelatto, R C; Lozinski, C P C; Azeredo, A; Fragoso, A B L; Cunha, H A; Torres, J P M; Malm, O

    2010-05-01

    Blubber samples from 33 Guiana dolphins (Sotalia guianensis) from three estuaries (Guanabara, Sepetiba/Ilha Grande and Paranaguá Bays) of Southern and Southeastern Brazil were analyzed for organochlorine compounds (DDTs, PCBs and HCB). The sampled individuals were incidentally captured in gillnet fishery between 1995 and 2005. The concentrations (in ng/g lipids) varied from 652 to 23 555 for SigmaDDT; from 765 to 99 175 for SigmaPCB; and from <4.4 to 156 for HCB. The results have shown that cetaceans from Brazil present organochlorine concentrations that are comparable to those reported for highly industrialized regions of Northern Hemisphere. Using discriminant analysis it was possible to verify that the dolphin populations from the three bays present different organochlorine accumulation patterns. This feature allows the use of this set of pollutants as an auxiliary tool for identification of different populations of the species off Brazilian Coast. PMID:19932538

  17. High Radon concentration in the karst area of south Puglia, Italy

    NASA Astrophysics Data System (ADS)

    Taroni, Mattia; Bartolomei, Paolo; Esposito, Massimo; Vaccaro, Carmela

    2010-05-01

    foreseen: Samples of rocks and soils to determine the Uranium concentration; Collection of water samples for the determination of Radon concentrations; Measurements of the Radon concentration in soil air; The Lecce's area is divided into 4 sub-areas, each of them with the same geological features: subsoil structure with high/normal/low fracturing, cracking, permeability, porosity, ecc... The potential Radon risk increases with the alteration's degree of subsoil structure. Results show that the 4 Lecce's subareas are characterized by average Radon value between 1.000-2.000 Bq/m3, and that in 2 of the 4 zones, characterized by high fracturing and big permeability, the range is high, from 400 Bq/m3 to over the 60.000 Bq/m3. The distribution of anomalies isn't homogeneous in the study zone, but as Hot-Spot and these are present in all sub-areas; the greatest number is detected in areas with high fracturing and cracking and in areas with lithological changes at different permeability. The others determinants factors in these areas are those anthropogenic; in some little zones belonging to subareas there are industrial and commercial areas built removing soil and damaging and altering the subsoil structure; in this way create zones of Radon accumulation in the soil air with fast ascent of the gas to the surface, and this produce high Radon concentration indoor. In the soil around these areas, few meters from buildings, and in the indoor air the Radon concentration is higher than 60.000 Bq/m3.

  18. A model for the frequency dispersion of the high-k metal-oxide-semiconductor capacitance in accumulation

    NASA Astrophysics Data System (ADS)

    Yao, B.; Fang, Z. B.; Zhu, Y. Y.; Ji, T.; He, G.

    2012-05-01

    High-frequency capacitance-voltage measurements have been made on metal-oxide-semiconductor capacitors by using single crystalline Er2O3 high-k gate dielectrics. Based on our analysis, it has been found that frequency dispersion of Er2O3 capacitance in accumulation decreases consistently with the increase of the frequency. A correction model is proposed to explain these frequency dispersion phenomena and the capacitance-frequency equations are obtained from the impedance expression of the equivalent circuit. Based on the simulated capacitance-frequency, it can be concluded that frequency dispersion of Er2O3 capacitance in accumulation originates from the existence of the parasitic resistances, the series resistances, and the formed SiOx interfacial layer.

  19. Bandgap Engineering in High-Efficiency Multijunction Concentrator Cells

    SciTech Connect

    King, R. R.; Sherif, R. A.; Kinsey, G. S.; Kurtz, S.; Fetzer, C. M.; Edmondson, K. M.; Law, D. C.; Cotal, H. L.; Krut, D. D.; Ermer, J. H.; Karam, N. H.

    2005-08-01

    This paper discusses semiconductor device research paths under investigation with the aim of reaching the milestone efficiency of 40%. A cost analysis shows that achieving very high cell efficiencies is crucial for the realization of cost-effective photovoltaics, because of the strongly leveraging effect of efficiency on module packaging and balance-of systems costs. Lattice-matched (LM) GaInP/ GaInAs/ Ge 3-junction cells have achieved the highest independently confirmed efficiency at 175 suns, 25?C, of 37.3% under the standard AM1.5D, low-AOD terrestrial spectrum. Lattice-mismatched, or metamorphic (MM), materials offer still higher potential efficiencies, if the crystal quality can be maintained. Theoretical efficiencies well over 50% are possible for a MM GaInP/ 1.17-eV GaInAs/ Ge 3-junction cell limited by radiative recombination at 500 suns. The bandgap - open circuit voltage offset, (Eg/q) - Voc, is used as a valuable theoretical and experimental tool to characterize multijunction cells with subcell bandgaps ranging from 0.7 to 2.1 eV. Experimental results are presented for prototype 6-junction cells employing an active {approx}1.1-eV dilute nitride GaInNAs subcell, with active-area efficiency greater than 23% and over 5.3 V open-circuit voltage under the 1-sun AM0 space spectrum. Such cell designs have theoretical efficiencies under the terrestrial spectrum at 500 suns concentration exceeding 55% efficiency, even for lattice-matched designs.

  20. Self-concentrating buoyant glass microbubbles for high sensitivity immunoassays.

    PubMed

    Juang, Duane S; Hsu, Chia-Hsien

    2016-02-01

    Here, we report the novel application of a material with self-concentrating properties for enhancing the sensitivity of immunoassays. Termed as glass microbubbles, they are antibody functionalized buoyant hollow glass microspheres that simultaneously float and concentrate into a dense monolayer when dispensed in a liquid droplet. This self-concentrating charactaristic of the microbubbles allow for autonomous signal localization, which translates to a higher sensitivity compared to other microparticle-based immunoassays. We then demonstrated a "microbubble array" platform consisting of the glass microbubbles floating in a microfluidic liquid hemisphere array for performing multiplex immunoassays. PMID:26620967

  1. Biodegradation of high concentrations of tetrachloroethene in a continuous flow column system

    SciTech Connect

    Isalou, M; Sleep, B.E.; Liss, S.N.

    1998-11-15

    A long-term (2.5 years) study of the anaerobic biodegradation of high concentrations of perchloroethylene (PCE) was carried out in a continuously operated laboratory column filled with sand which was inoculated with biomass from an anaerobic digester. Concentrations of PCE fed to the column were increased from 12 {micro}M to over 600 {micro}M over 21 months, with methanol added as electron donor. Vinyl chloride (VC) was the terminal product of PCE dechlorination for the first 21 months at which point significant conversion of VC to ethylene (ETH) was detected. The onset of ETH production coincided with acetogenesis becoming the primary pathway for methanol metabolism. ETH production occurred in the column in the presence of PCE and TCE. Varying methanol:PCE molar ratios from 1.4 to 7.5 had little effect on the transformation of PCE and TCE to VC. The degradation of VC to ETH was much more sensitive, and VC accumulated when the methanol:PCE molar ratio dropped below 5.0. Withdrawal of PCE from the system for a 5 month period and maintenance of the column on methanol alone did not result in the loss of PCE degradation capability of the consortium.

  2. Vitamin d deficiency attenuates high-fat diet-induced hyperinsulinemia and hepatic lipid accumulation in male mice.

    PubMed

    Liu, Xiao-Jing; Wang, Bi-Wei; Zhang, Cheng; Xia, Mi-Zhen; Chen, Yuan-Hua; Hu, Chun-Qiu; Wang, Hua; Chen, Xi; Xu, De-Xiang

    2015-06-01

    It is increasingly recognized that vitamin D deficiency is associated with increased risks of metabolic disorders among overweight children. A recent study showed that vitamin D deficiency exacerbated inflammation in nonalcoholic fatty liver disease through activating toll-like receptor 4 in a high-fat diet (HFD) rat model. The present study aimed to further investigate the effects of vitamin D deficiency on HFD-induced insulin resistance and hepatic lipid accumulation. Male ICR mice (35 d old) were randomly assigned into 4 groups as follows. In control diet and vitamin D deficiency diet (VDD) groups, mice were fed with purified diets. In HFD and VDD+HFD groups, mice were fed with HFD. In VDD and VDD+HFD groups, vitamin D in feed was depleted. Feeding mice with vitamin D deficiency diet did not induce obesity, insulin resistance, and hepatic lipid accumulation. By contrary, vitamin D deficiency markedly alleviated HFD-induced overweight, hyperinsulinemia, and hepatic lipid accumulation. Moreover, vitamin D deficiency significantly attenuated HFD-induced up-regulation of hepatic peroxisome proliferator-activated receptor γ, which promoted hepatic lipid uptake and lipid droplet formation, and its target gene cluster of differentiation 36. In addition, vitamin D deficiency up-regulated carnitine palmitoyltrans 2, the key enzyme for fatty acid β-oxidation, and uncoupling protein 3, which separated oxidative phosphorylation from ATP production, in adipose tissue. These data suggest that vitamin D deficiency is not a direct risk factor for obesity, insulin resistance, and hepatic lipid accumulation. Vitamin D deficiency alleviates HFD-induced overweight, hyperinsulinemia, and hepatic lipid accumulation through promoting fatty acid β-oxidation and elevating energy expenditure in adipose tissue. PMID:25774554

  3. Screening of a new cadmium hyperaccumulator, Galinsoga parviflora, from winter farmland weeds using the artificially high soil cadmium concentration method.

    PubMed

    Lin, Lijin; Jin, Qian; Liu, Yingjie; Ning, Bo; Liao, Ming'an; Luo, Li

    2014-11-01

    A new method, the artificially high soil cadmium (Cd) concentration method, was used to screen for Cd hyperaccumulators among winter farmland weeds. Galinsoga parviflora was the most promising remedial plant among 5 Cd accumulators or hyperaccumulators. In Cd concentration gradient experiments, as soil Cd concentration increased, root and shoot biomass decreased, and their Cd contents increased. In additional concentration gradient experiments, superoxide dismutase and peroxidase activities increased with soil Cd concentrations up to 75 mg kg(-1) , while expression of their isoenzymes strengthened. Catalase (CAT) activity declined and CAT isoenzyme expression weakened at soil Cd concentrations less than 50 mg kg(-1) . The maxima of Cd contents in shoots and roots were 137.63 mg kg(-1) and 105.70 mg kg(-1) , respectively, at 100 mg kg(-1) Cd in soil. The root and shoot bioconcentration factors exceeded 1.0, as did the translocation factor. In a field experiment, total extraction of Cd by shoots was 1.35 mg m(-2) to 1.43 mg m(-2) at soil Cd levels of 2.04 mg kg(-1) to 2.89 mg kg(-1) . Therefore, the artificially high soil Cd concentration method was effective for screening Cd hyperaccumulators. Galinsoga parviflora is a Cd hyperaccumulator that could be used to efficiently remediate Cd-contaminated farmland soil. PMID:25053512

  4. High-throughput concentration-response analysis for omics datasets.

    PubMed

    Smetanová, Soňa; Riedl, Janet; Zitzkat, Dimitar; Altenburger, Rolf; Busch, Wibke

    2015-09-01

    Omics-based methods are increasingly used in current ecotoxicology. Therefore, a large number of observations for various toxic substances and organisms are available and may be used for identifying modes of action, adverse outcome pathways, or novel biomarkers. For these purposes, good statistical analysis of toxicogenomic data is vital. In contrast to established ecotoxicological techniques, concentration-response modeling is rarely used for large datasets. Instead, statistical hypothesis testing is prevalent, which provides only a limited scope for inference. The present study therefore applied automated concentration-response modeling for 3 different ecotoxicotranscriptomic and ecotoxicometabolomic datasets. The modeling process was performed by simultaneously applying 9 different regression models, representing distinct mechanistic, toxicological, and statistical ideas that result in different curve shapes. The best-fitting models were selected by using Akaike's information criterion. The linear and exponential models represented the best data description for more than 50% of responses. Models generating U-shaped curves were frequently selected for transcriptomic signals (30%), and sigmoid models were identified as best fit for many metabolomic signals (21%). Thus, selecting the models from an array of different types seems appropriate, because concentration-response functions may vary because of the observed response type, and they also depend on the compound, the organism, and the investigated concentration and exposure duration range. The application of concentration-response models can help to further tap the potential of omics data and is a necessary step for quantitative mixture effect assessment at the molecular response level. PMID:25900799

  5. High concentrations of Na+ and Cl– ions in soil solution have simultaneous detrimental effects on growth of faba bean under salinity stress

    PubMed Central

    Tavakkoli, Ehsan; Rengasamy, Pichu; McDonald, Glenn K.

    2010-01-01

    Despite the fact that most plants accumulate both sodium (Na+) and chloride (Cl–) ions to high concentration in their shoot tissues when grown in saline soils, most research on salt tolerance in annual plants has focused on the toxic effects of Na+ accumulation. There have also been some recent concerns about the ability of hydroponic systems to predict the responses of plants to salinity in soil. To address these two issues, an experiment was conducted to compare the responses to Na+ and to Cl– separately in comparison with the response to NaCl in a soil-based system using two varieties of faba bean (Vicia faba), that differed in salinity tolerance. The variety Nura is a salt-sensitive variety that accumulates Na+ and Cl– to high concentrations while the line 1487/7 is salt tolerant which accumulates lower concentrations of Na+ and Cl–. Soils were prepared which were treated with Na+ or Cl– by using a combination of different Na+ salts and Cl– salts, respectively, or with NaCl. While this method produced Na+-dominant and Cl–-dominant soils, it unavoidably led to changes in the availability of other anions and cations, but tissue analysis of the plants did not indicate any nutritional deficiencies or toxicities other than those targeted by the salt treatments. The growth, water use, ionic composition, photosynthesis, and chlorophyll fluorescence were measured. Both high Na+ and high Cl– reduced growth of faba bean but plants were more sensitive to Cl– than to Na+. The reductions in growth and photosynthesis were greater under NaCl stress and the effect was mainly additive. An important difference to previous hydroponic studies was that increasing the concentrations of NaCl in the soil increased the concentration of Cl– more than the concentration of Na+. The data showed that salinity caused by high concentrations of NaCl can reduce growth by the accumulation of high concentrations of both Na+ and Cl– simultaneously, but the effects of the two

  6. High concentrations of Na+ and Cl- ions in soil solution have simultaneous detrimental effects on growth of faba bean under salinity stress.

    PubMed

    Tavakkoli, Ehsan; Rengasamy, Pichu; McDonald, Glenn K

    2010-10-01

    Despite the fact that most plants accumulate both sodium (Na(+)) and chloride (Cl(-)) ions to high concentration in their shoot tissues when grown in saline soils, most research on salt tolerance in annual plants has focused on the toxic effects of Na(+) accumulation. There have also been some recent concerns about the ability of hydroponic systems to predict the responses of plants to salinity in soil. To address these two issues, an experiment was conducted to compare the responses to Na(+) and to Cl(-) separately in comparison with the response to NaCl in a soil-based system using two varieties of faba bean (Vicia faba), that differed in salinity tolerance. The variety Nura is a salt-sensitive variety that accumulates Na(+) and Cl(-) to high concentrations while the line 1487/7 is salt tolerant which accumulates lower concentrations of Na(+) and Cl(-). Soils were prepared which were treated with Na(+) or Cl(-) by using a combination of different Na(+) salts and Cl(-) salts, respectively, or with NaCl. While this method produced Na(+)-dominant and Cl(-)-dominant soils, it unavoidably led to changes in the availability of other anions and cations, but tissue analysis of the plants did not indicate any nutritional deficiencies or toxicities other than those targeted by the salt treatments. The growth, water use, ionic composition, photosynthesis, and chlorophyll fluorescence were measured. Both high Na(+) and high Cl(-) reduced growth of faba bean but plants were more sensitive to Cl(-) than to Na(+). The reductions in growth and photosynthesis were greater under NaCl stress and the effect was mainly additive. An important difference to previous hydroponic studies was that increasing the concentrations of NaCl in the soil increased the concentration of Cl(-) more than the concentration of Na(+). The data showed that salinity caused by high concentrations of NaCl can reduce growth by the accumulation of high concentrations of both Na(+) and Cl(-) simultaneously, but

  7. Optimized Rapeseed Oils Rich in Endogenous Micronutrients Protect High Fat Diet Fed Rats from Hepatic Lipid Accumulation and Oxidative Stress

    PubMed Central

    Xu, Jiqu; Liu, Xiaoli; Gao, Hui; Chen, Chang; Deng, Qianchun; Huang, Qingde; Ma, Zhonghua; Huang, Fenghong

    2015-01-01

    Micronutrients in rapeseed exert a potential benefit to hepatoprotection, but most of them are lost during the conventional refining processing. Thus some processing technologies have been optimized to improve micronutrient retention in oil. The aim of this study is to assess whether optimized rapeseed oils (OROs) have positive effects on hepatic lipid accumulation and oxidative stress induced by a high-fat diet. Methods: Rats received experiment diets containing 20% fat and refined rapeseed oil or OROs obtained with various processing technologies as lipid source. After 10 weeks of treatment, liver was assayed for lipid accumulation and oxidative stress. Results: All OROs reduced hepatic triglyceride contents. Microwave pretreatment-cold pressing oil (MPCPO) which had the highest micronutrients contents also reduced hepatic cholesterol level. MPCPO significantly decreased hepatic sterol regulatory element-binding transcription factor 1 (SREBP1) but increased peroxisome proliferator activated receptor α (PPARα) expressions, and as a result, MPCPO significantly suppressed acetyl CoA carboxylase and induced carnitine palmitoyl transferase-1 and acyl CoA oxidase expression. Hepatic catalase (CAT) and glutathione peroxidase (GPx) activities as well as reduced glutathione (GSH) contents remarkably increased and lipid peroxidation levels decreased in parallel with the increase of micronutrients. Conclusion: OROs had the ability to reduce excessive hepatic fat accumulation and oxidative stress, which indicated that OROs might contribute to ameliorating nonalcoholic fatty liver induced by high-fat diet. PMID:26473919

  8. Culture Conditions stimulating high γ-Linolenic Acid accumulation by Spirulina platensis

    PubMed Central

    Ronda, Srinivasa Reddy; Lele, S.S.

    2008-01-01

    Gamma-linolenic acid (GLA) production by Spirulina platensis under different stress-inducing conditions was studied. Submerged culture studies showed that low temperature (25°C), strong light intensity (6 klux) and primrose oil supplement (0.8%w/v) induced 13.2 mg/g, 14.6 mg/g and 13.5 mg linolenic acid per gram dry cell weight respectively. A careful observation of fatty acid profile of the cyanobacteria shows that, oleic acid and linoleic acid, in experiments with varying growth temperature and oil supplements respectively, helped in accumulating excess γ-linolenic acid. In addition, cultures grown at increasing light regimes maintained the γ-linolenic acid to the total fatty acid ratio(GLA/TFA) constant, despite any change in γ-linolenic acid content of the cyanobacteria. PMID:24031291

  9. Effects of salicylic acid on thermotolerance and cardenolide accumulation under high temperature stress in Digitalis trojana Ivanina.

    PubMed

    Cingoz, Gunce Sahin; Gurel, Ekrem

    2016-08-01

    Long periods of high temperature or transitory increased temperature, a widespread agricultural problem, may lead to a drastic reduction in economic yield, affecting plant growth and development in many areas of the world. Heat stress causes many anatomical and physiological changes in plants. Its unfavorable effects can be alleviated by thermotolerance induced by exogenous application of plant growth regulators and osmoprotectants or by gradual application of temperature stress. Digitalis trojana Ivanina is an important medicinal plant species well known mainly for its cardenolides. The production of cardenolides via traditional agriculture is commercially inadequate. In this study, elicitation strategies were employed for improving crop thermotolerance and accumulation of cardenolides. For these purposes, the effects of salicylic acid (SA) and/or high temperature treatments in inducing cardenolide accumulation and thermotolerance were tested in callus cultures of D. trojana. Considerable increases in the production of cardenolides (up to 472.28 μg.g(-1) dry weight, dw) and induction of thermotolerance capacity were observed when callus cultures were exposed to high temperature for 2 h after pretreating with SA. High temperature treatments (2 h and 4 h) caused a marked reduction in superoxide dismutase (SOD; EC 1.15.1.1) and catalase (CAT; EC 1.11.1.6) activities, while SA pretreatment increased their activities. High temperature and/or SA appeared to increase the levels of proline, total phenolic, and flavonoid content. Elevated phenolic accumulation could be associated with increased stress protection. These results indicated that SA treatments induced synthesis of antioxidants and cardenolides, which may play a significant role in resistance to high temperature stress. PMID:27105421

  10. Development of manufacturing capability for high-concentration, high-efficiency silicon solar cells

    SciTech Connect

    Sinton, R.A.; Verlinden, P.J.; Crane, R.A.; Swanson, R.N.

    1996-10-01

    This report presents a summary of the major results from a program to develop a manufacturable, high-efficiency silicon concentrator solar cell and a cost-effective manufacturing facility. The program was jointly funded by the Electric Power Research Institute, Sandia National Laboratories through the Concentrator Initiative, and SunPower Corporation. The key achievements of the program include the demonstration of 26%-efficient silicon concentrator solar cells with design-point (20 W/cm{sup 2}) efficiencies over 25%. High-performance front-surface passivations; that were developed to achieve this result were verified to be absolutely stable against degradation by 475 days of field exposure at twice the design concentration. SunPower demonstrated pilot production of more than 1500 of these cells. This cell technology was also applied to pilot production to supply 7000 17.7-cm{sup 2} one-sun cells (3500 yielded wafers) that demonstrated exceptional quality control. The average efficiency of 21.3% for these cells approaches the peak efficiency ever demonstrated for a single small laboratory cell within 2% (absolute). Extensive cost models were developed through this program and calibrated by the pilot-production project. The production levels achieved indicate that SunPower could produce 7-10 MW of concentrator cells per year in the current facility based upon the cell performance demonstrated during the program.

  11. Methods and devices for high-throughput dielectrophoretic concentration

    DOEpatents

    Simmons, Blake A.; Cummings, Eric B.; Fiechtner, Gregory J.; Fintschenko, Yolanda; McGraw, Gregory J.; Salmi, Allen

    2010-02-23

    Disclosed herein are methods and devices for assaying and concentrating analytes in a fluid sample using dielectrophoresis. As disclosed, the methods and devices utilize substrates having a plurality of pores through which analytes can be selectively prevented from passing, or inhibited, on application of an appropriate electric field waveform. The pores of the substrate produce nonuniform electric field having local extrema located near the pores. These nonuniform fields drive dielectrophoresis, which produces the inhibition. Arrangements of electrodes and porous substrates support continuous, bulk, multi-dimensional, and staged selective concentration.

  12. [High concentration ethanol continuous fermentation using yeast flocs].

    PubMed

    Liu, C; Bai, F; Shao, M; Xie, J; Li, N

    2001-06-01

    Continuous ethanol fermentation using yeast flocs was carried out in 4 air-lift suspended-bed bioreactors operated in series. Drafted by CO2, with complete recycle of ethanol distilled effluent broth and at the dilution rate of 0.2/h, the average ethanol concentration of the fermentation broth was 96.6 g/L, while the average concentration of residual total sugar was 4.1 g/L and residual reducing sugar was 1.2 g/L. PMID:12549094

  13. 27 CFR 18.52 - Production of high-proof concentrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... concentrate. 18.52 Section 18.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS PRODUCTION OF VOLATILE FRUIT-FLAVOR CONCENTRATE Operations § 18.52 Production of high-proof concentrate. (a) General. High-proof concentrate may be produced in...

  14. High glucose concentrations attenuate hypoxia-inducible factor-1{alpha} expression and signaling in non-tumor cells

    SciTech Connect

    Dehne, Nathalie; Bruene, Bernhard

    2010-04-15

    Hypoxia-inducible factor (HIF) is the major transcription factor mediating adaption to hypoxia e.g. by enhancing glycolysis. In tumor cells, high glucose concentrations are known to increase HIF-1{alpha} expression even under normoxia, presumably by enhancing the concentration of tricarboxylic acid cycle intermediates, while reactions of non-tumor cells are not well defined. Therefore, we analyzed cellular responses to different glucose concentrations in respect to HIF activation comparing tumor to non-tumor cells. Using cells derived from non-tumor origin, we show that HIF-1{alpha} accumulation was higher under low compared to high glucose concentrations. Low glucose allowed mRNA expression of HIF-1 target genes like adrenomedullin. Transfection of C{sub 2}C{sub 12} cells with a HIF-1{alpha} oxygen-dependent degradation domaine-GFP fusion protein revealed that prolyl hydroxylase (PHD) activity is impaired at low glucose concentrations, thus stabilizing the fusion protein. Mechanistic considerations suggested that neither O{sub 2} redistribution nor an altered redox state explains impaired PHD activity in the absence of glucose. In order to affect PHD activity, glucose needs to be metabolized. Amino acids present in the medium also diminished HIF-1{alpha} expression, while the addition of fatty acids did not. This suggests that glucose or amino acid metabolism increases oxoglutarate concentrations, which enhances PHD activity in non-tumor cells. Tumor cells deprived of glutamine showed HIF-1{alpha} accumulation in the absence of glucose, proposing that enhanced glutaminolysis observed in many tumors enables these cells to compensate reduced oxoglutarate production in the absence of glucose.

  15. Effects of the Polysaccharide from the Sporophyll of Brown Alga Undaria Pinnatifida on Serum Lipid Profile and Fat Tissue Accumulation in Rats Fed a High-Fat Diet.

    PubMed

    Kim, Byoung-Mok; Park, Jae-Ho; Kim, Dong-Soo; Kim, Young-Myung; Jun, Joon-Young; Jeong, In-Hak; Chi, Young-Min

    2016-07-01

    We investigated the effects of the polysaccharide from the sporophyll of a selected brown alga Undaria pinnatifida on serum lipid profile, fat tissue accumulation, and gastrointestinal transit time in rats fed a high-fat diet. The algal polysaccharide (AP) was prepared by the treatment of multiple cellulase-producing fungi Trichoderma reesei and obtained from the sporophyll with a yield of 38.7% (dry basis). The AP was mostly composed of alginate and fucoidan (up to 89%) in a ratio of 3.75:1. The AP was added to the high-fat diet in concentrations of 0.6% and 1.7% and was given to male Sprague-Dawley rats (5-wk-old) for 5 wk. The 1.7% AP addition notably reduced body weight gain and fat tissue accumulation, and it improved the serum lipid profile, including triglycerides, total cholesterol, and very low-density lipoprotein-cholesterol. The effects were associated with increased feces weight and shortened gastrointestinal transit time. In addition, the lipid peroxidation of the liver was decreased in both groups. PMID:27384013

  16. [Detoxification of high concentrations of trinitrotoluene by bacteria].

    PubMed

    Solianikova, I P; Baskunov, B P; Baboshin, M A; Saralov, A I; Golovleva, L A

    2012-01-01

    The ability of the strains-destructors of various aromatic compounds to utilize trinitrotoluene (TNT) up to concentration of 70 mg/1 was shown. An increase in the TNT concentration from 100 to 150 mg/1 did not inhibit its conversion rate by the Kocuria palustris RS32 strain. The Acinetobacter sp. VT 11 strain utilized TNT as a sole substrate for growth; 3,5-dinitro-4-methyl anilide acetate and 2,6-dinitro-4-aminotoluene were identified as intermediates of TNT degradation by active strains of Pseudomonas sp. VT-7W and Kocuria rosea RS51. At the same time, 4-methyl-3,5-dinitroformamide was discovered for the first time upon the TNT destruction by the bacteria strains of Rhodococcus opacus 1G and Rhodococcus sp. VT-7. The active bacterial strains achieved an 82-90% destruction of TNT when they were introduced into the soil. PMID:22567882

  17. P accumulation and physiological responses to different high P regimes in Polygonum hydropiper for understanding a P-phytoremediation strategy.

    PubMed

    Ye, Daihua; Li, Tingxuan; Liu, Dan; Zhang, Xizhou; Zheng, Zicheng

    2015-01-01

    Phosphorus (P) accumulators used for phytoremediation vary in their potential to acquire P from different high P regimes. Growth and P accumulation in Polygonum hydropiper were both dependent on an increasing level of IHP (1-8 mM P) and on a prolonged growth period (3-9 weeks), and those of the mining ecotype (ME) were higher than the non-mining ecotype (NME). Biomass increments in root, stem, and leaf of both ecotypes were significantly greater in IHP relative to other organic P (Po) sources (G1P, AMP, ATP), but lower than those in inorganic P (Pi) treatment (KH2PO4). P accumulation in the ME exceeded the NME from different P regimes. The ME demonstrated higher root activity compared to the NME grown in various P sources. Acid phosphatase (Apase) and phytase activities in root extracts of both ecotypes grown in IHP were comparable to that in Pi, or even higher in IHP. Higher secreted Apase and phytase activities were detected in the ME treated with different P sources relative to the NME. Therefore, the ME demonstrates higher P-uptake efficiency and it is a potential material for phytoextraction from P contaminated areas, irrespective of Pi or Po contamination. PMID:26648137

  18. P accumulation and physiological responses to different high P regimes in Polygonum hydropiper for understanding a P-phytoremediation strategy

    PubMed Central

    Ye, Daihua; Li, Tingxuan; Liu, Dan; Zhang, Xizhou; Zheng, Zicheng

    2015-01-01

    Phosphorus (P) accumulators used for phytoremediation vary in their potential to acquire P from different high P regimes. Growth and P accumulation in Polygonum hydropiper were both dependent on an increasing level of IHP (1–8 mM P) and on a prolonged growth period (3-9 weeks), and those of the mining ecotype (ME) were higher than the non-mining ecotype (NME). Biomass increments in root, stem, and leaf of both ecotypes were significantly greater in IHP relative to other organic P (Po) sources (G1P, AMP, ATP), but lower than those in inorganic P (Pi) treatment (KH2PO4). P accumulation in the ME exceeded the NME from different P regimes. The ME demonstrated higher root activity compared to the NME grown in various P sources. Acid phosphatase (Apase) and phytase activities in root extracts of both ecotypes grown in IHP were comparable to that in Pi, or even higher in IHP. Higher secreted Apase and phytase activities were detected in the ME treated with different P sources relative to the NME. Therefore, the ME demonstrates higher P-uptake efficiency and it is a potential material for phytoextraction from P contaminated areas, irrespective of Pi or Po contamination. PMID:26648137

  19. Concentration measurement of yeast suspensions using high frequency ultrasound backscattering.

    PubMed

    Elvira, Luis; Vera, Pedro; Cañadas, Francisco Jesús; Shukla, Shiva Kant; Montero, Francisco

    2016-01-01

    This work proposes the use of an ultrasound based technique to measure the concentration of yeasts in liquid suspension. This measurement was achieved by the detection and quantification of ultrasonic echoes backscattered by the cells. More specifically, the technique was applied to the detection and quantification of Saccharomyces cerevisiae. A theoretical approach was proposed to get the average density and sound speed of the yeasts, which were found to be 1116 kg/m(3) and 1679 m/s, respectively. These parameters were needed to model the waves backscattered by each single cell. A pulse-echo arrangement working around 50 MHz, being able to detect echoes from single yeasts was used to characterize experimentally yeast solutions from 10(2) to 10(7)cells/ml. The Non-negative Matrix Factorization denoising technique was applied for data analysis. This technique required a previous learning of the spectral patterns of the echoes reflected from yeasts in solution and the base noise from the liquid medium. Comparison between pulse correlation (without denoising) and theoretical and experimental pattern learning was made to select the best signal processing. A linear relation between ultrasound output and concentration was obtained with correlation coefficient R(2)=0.996 for the experimental learning. Concentrations from 10(4) to 10(7)cells/ml were detected above the base noise. These results show the viability of using the ultrasound backscattering technique to detect yeasts and measure their concentration in liquid cultures, improving the sensitivity obtained using spectrophotometric methods by one order of magnitude. PMID:26361271

  20. Dimerization in Highly Concentrated Solutions of Phosphoimidazolide Activated Mononucleotides

    NASA Technical Reports Server (NTRS)

    Kanavarioti, Anastassia

    1997-01-01

    Phosphoimidazolide activated ribomononucleotides (*pN) are useful substrates for the non-enzymatic synthesis of polynucleotides. However, dilute neutral aqueous solutions of *pN typically yield small amounts of dimers and traces of polymers; most of *pN hydrolyzes to yield nucleoside 5'-monophosphate. Here we report the self-condensation of nucleoside 5'-phosphate 2- methylimidazolide (2-MeImpN with N = cytidine, uridine or guanosine) in the presence of Mg2(+) in concentrated solutions, such as might have been found in an evaporating lagoon on prebiotic Earth. The product distribution indicates that oligomerization is favored at the expense of hydrolysis. At 1.0 M, 2-MelmpU and 2-MelmpC produce about 65% of oligomers including 4% of the 3',5'-Iinked dimer. Examination of the product distribution of the three isomeric dimers in a self-condensation allows identification of reaction pathways that lead to dimer formation. Condensations in a concentrated mixture of all three nucleotides (U,C,G mixtures) is made possible by the enhanced solubility of 2-MeImpG in such mixtures. Although percent yield of intemucleotide linked dimers is enhanced as a function of initial monomer concentration, pyrophosphate dimer yields remain practically unchanged at about 20% for 2-MelmpU, 16% for 2-MeImpC and 25% of the total pyrophosphate in the U,C,G mixtures. The efficiency by which oligomers are produced in these concentrated solutions makes the evaporating lagoon scenario a potentially interesting medium for the prebiotic synthesis of dimers and short RNAs.

  1. Effect of low ambient mineral concentrations on the accumulation of calcium, magnesium and phosphorus by early life stages of the air-breathing armoured catfish Megalechis personata (Siluriformes: Callichthyidae).

    PubMed

    Mol, J H; Atsma, W; Flik, G; Bouwmeester, H; Osse, J W

    1999-08-01

    The accumulation of calcium, magnesium and phosphorus was measured during an 8-week period in the early life stages of the air-breathing armoured catfish Megalechis personata acclimated to low-mineral fresh water (0.073 mmol l-1 calcium, 0.015 mmol l-1 magnesium, <0.001 mmol l-1 phosphate) and high-mineral fresh water (0.59 mmol l-1 calcium, 1.94 mmol l-1 magnesium, <0.001 mmol l-1 phosphate). The fish accumulated calcium twice as fast and phosphorus 1.5 times as fast in low-mineral fresh water (LMF) as in high-mineral fresh water (HMF), while the rate of accumulation of magnesium did not differ in LMF and HMF. The difference in the rates of accumulation of calcium and phosphorus between LMF and HMF was independent of the growth performance (food intake) in LMF and HMF. The mineral content of young M. personata from natural swamps and rainforest creeks in Suriname followed the LMF accumulation curves. The transition from aquatic respiration to bimodal respiration in the third week after hatching did not affect rates of mineral accumulation. The high rates of accumulation of calcium and magnesium of M. personata in LMF of 654 and 58 micromol h-1 kg-1, respectively, exceed the rates of uptake of calcium and magnesium of teleosts reported in the literature. The high rates of mineral accumulation in the early life stages of M. personata reflect the exponential growth during the first 8 weeks after hatching and the requirements of the juveniles while building their dermal armour. M. personata is well-adapted to neotropical fresh waters with an extremely low mineral content. The accumulation of calcium and phosphorus is discussed in relation to the function of the bony armour of M. personata. PMID:10393827

  2. 27 CFR 18.52 - Production of high-proof concentrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Production of high-proof... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS PRODUCTION OF VOLATILE FRUIT-FLAVOR CONCENTRATE Operations § 18.52 Production of high-proof concentrate. (a) General. High-proof concentrate may be produced in...

  3. Unexpectedly high indoor hydroxyl radical concentrations associated with nitrous acid.

    PubMed

    Gómez Alvarez, Elena; Amedro, Damien; Afif, Charbel; Gligorovski, Sasho; Schoemaecker, Coralie; Schoemacker, Coralie; Fittschen, Christa; Doussin, Jean-Francois; Wortham, Henri

    2013-08-13

    The hydroxyl (OH) radical is the most important oxidant in the atmosphere since it controls its self-oxidizing capacity. The main sources of OH radicals are the photolysis of ozone and the photolysis of nitrous acid (HONO). Due to the attenuation of solar radiation in the indoor environment, the possibility of OH formation through photolytic pathways indoors has been ignored up to now. In the indoor air, the ozonolysis of alkenes has been suggested as an alternative route of OH formation. Models and indirect measurements performed up to now according to this hypothesis suggest concentrations of OH radicals on the order of 10(4)-10(5) molecules per cubic centimeter. Here, we present direct measurements of significant amounts of OH radicals of up to 1.8⋅10(6) molecules per cubic centimeter during an experimental campaign carried out in a school classroom in Marseille. This concentration is on the same order of magnitude of outdoor OH levels in the urban scenario. We also show that photolysis of HONO is an important source of OH radicals indoors under certain conditions (i.e., direct solar irradiation inside the room). Additionally, the OH concentrations were found to follow a linear dependence with the product J(HONO)⋅[HONO]. This was also supported by using a simple quasiphotostationary state model on the OH radical budget. These findings force a change in our understanding of indoor air quality because the reactivity linked to OH would involve formation of secondary species through chemical reactions that are potentially more hazardous than the primary pollutants in the indoor air. PMID:23898188

  4. Unexpectedly high indoor hydroxyl radical concentrations associated with nitrous acid

    PubMed Central

    Gómez Alvarez, Elena; Amedro, Damien; Afif, Charbel; Gligorovski, Sasho; Schoemaecker, Coralie; Fittschen, Christa; Doussin, Jean-Francois; Wortham, Henri

    2013-01-01

    The hydroxyl (OH) radical is the most important oxidant in the atmosphere since it controls its self-oxidizing capacity. The main sources of OH radicals are the photolysis of ozone and the photolysis of nitrous acid (HONO). Due to the attenuation of solar radiation in the indoor environment, the possibility of OH formation through photolytic pathways indoors has been ignored up to now. In the indoor air, the ozonolysis of alkenes has been suggested as an alternative route of OH formation. Models and indirect measurements performed up to now according to this hypothesis suggest concentrations of OH radicals on the order of 104–105 molecules per cubic centimeter. Here, we present direct measurements of significant amounts of OH radicals of up to 1.8⋅106 molecules per cubic centimeter during an experimental campaign carried out in a school classroom in Marseille. This concentration is on the same order of magnitude of outdoor OH levels in the urban scenario. We also show that photolysis of HONO is an important source of OH radicals indoors under certain conditions (i.e., direct solar irradiation inside the room). Additionally, the OH concentrations were found to follow a linear dependence with the product J(HONO)⋅[HONO]. This was also supported by using a simple quasiphotostationary state model on the OH radical budget. These findings force a change in our understanding of indoor air quality because the reactivity linked to OH would involve formation of secondary species through chemical reactions that are potentially more hazardous than the primary pollutants in the indoor air. PMID:23898188

  5. Effect of self-alkalization on nitrite accumulation in a high-rate denitrification system: Performance, microflora and enzymatic activities.

    PubMed

    Li, Wei; Shan, Xiao-Yu; Wang, Zhi-Yao; Lin, Xiao-Yu; Li, Chen-Xu; Cai, Chao-Yang; Abbas, Ghulam; Zhang, Meng; Shen, Li-Dong; Hu, Zhi-Qiang; Zhao, He-Ping; Zheng, Ping

    2016-01-01

    The self-alkalization of denitrifying automatic circulation (DAC) reactor resulted in a large increase of pH up to 9.20 and caused a tremendous accumulation of nitrite up to 451.1 ± 49.0 mgN L(-1) at nitrate loading rate (NLR) from 35 kgN m(-3) d(-1) to 55 kgN m(-3) d(-1). The nitrite accumulation was greatly relieved even at the same NLR once the pH was maintained at 7.6 ± 0.2 in the system. Enzymatic assays indicated that the long-term bacterial exposure to high pH significantly inhibited the activity of copper type nitrite reductase (NirK) rather than the cytochrome cd1 type nitrite reductase (NirS). The terminal restriction fragment length polymorphism (T-RFLP) analysis revealed that the dominant denitrifying bacteria shifted from the NirS-containing Thauear sp. 27 to the NirK-containing Hyphomicrobium nitrativorans strain NL23 during the self-alkalization. The significant nitrite accumulation in the high-rate denitrification system could be therefore, due to the inhibition of Cu-containing NirK by high pH from the self-alkalization. The results suggest that the NirK-containing H. nitrativorans strain NL23 could be an ideal functional bacterium for the conversion of nitrate to nitrite, i.e. denitritation, which could be combined with anaerobic ammonium oxidation (Anammox) to develop a new process for nitrogen removal from wastewater. PMID:26595097

  6. New PSA high concentration solar furnace SF40

    NASA Astrophysics Data System (ADS)

    Rodriguez, Jose; Cañadas, Inmaculada; Zarza, Eduardo

    2016-05-01

    A new solar furnace has been designed and built at Plataforma Solar de Almería. In this work, its main components such as heliostat, concentrator, attenuator and test table, and the method used to align them are described. Other equipment like the auxiliary systems necessary for the solar operation, vacuum chamber and gas system are outlined too. Finally, the thermal characteristics of the focus were measured during a test campaign, where different planes along the optical axis were scanned with a radiometer, and the peak flux was obtained and is presented in the last section of this report.

  7. Reductions in ozone at high concentrations of stratospheric halogens

    NASA Technical Reports Server (NTRS)

    Prather, M. J.; Mcelroy, M. B.; Wofsy, S. C.

    1984-01-01

    An increase in the concentration of inorganic chlorine to levels comparable to that of oxidized reactive nitrogen could cause a significant change in the chemistry of the lower stratosphere leading to a reduction potentially larger than 15 percent in the column density of ozone. This could occur, for example by the middle of the next century, if emissions of man-made chlorocarbons were to grow at a rate of 3 percent per year. Ozone could be further depressed by release of industrial bromocarbon.

  8. The anaesthesia of fish by high carbon-dioxide concentrations

    USGS Publications Warehouse

    1942-01-01

    A practical and economical method for anaesthetizing adult salmon and steelhead trout in the fish trucks used in the Grand Coulee fish salvage program is described. The method consists in generating a predetermined carbon-dioxide concentration in the 1000-gallon tanks of the trucks through the successive addition of predissolved sodium bicarbonate and dilute sulphuric acid in proper quantities. Carbon-dioxide anaesthesia effectively solved the acute problem of species segregation in the fish salvage program and, with minor modifications, could be used with equal success in certain hatchery operations necessitating the handling of large fish.

  9. High-performance flat-panel solar thermoelectric generators with high thermal concentration.

    PubMed

    Kraemer, Daniel; Poudel, Bed; Feng, Hsien-Ping; Caylor, J Christopher; Yu, Bo; Yan, Xiao; Ma, Yi; Wang, Xiaowei; Wang, Dezhi; Muto, Andrew; McEnaney, Kenneth; Chiesa, Matteo; Ren, Zhifeng; Chen, Gang

    2011-07-01

    The conversion of sunlight into electricity has been dominated by photovoltaic and solar thermal power generation. Photovoltaic cells are deployed widely, mostly as flat panels, whereas solar thermal electricity generation relying on optical concentrators and mechanical heat engines is only seen in large-scale power plants. Here we demonstrate a promising flat-panel solar thermal to electric power conversion technology based on the Seebeck effect and high thermal concentration, thus enabling wider applications. The developed solar thermoelectric generators (STEGs) achieved a peak efficiency of 4.6% under AM1.5G (1 kW m(-2)) conditions. The efficiency is 7-8 times higher than the previously reported best value for a flat-panel STEG, and is enabled by the use of high-performance nanostructured thermoelectric materials and spectrally-selective solar absorbers in an innovative design that exploits high thermal concentration in an evacuated environment. Our work opens up a promising new approach which has the potential to achieve cost-effective conversion of solar energy into electricity. PMID:21532584

  10. High nitrate to phosphorus ratio attenuates negative effects of rising pCO2 on net population carbon accumulation

    NASA Astrophysics Data System (ADS)

    Krug, S. A.; Eggers, S. L.; Matthiessen, B.

    2011-07-01

    The ongoing rise in atmospheric pCO2 and the consequent increase in ocean acidification have direct effects on marine calcifying phytoplankton which potentially translates into altered carbon export. To date it remains unclear first, how nutrient ratio, in particular from coccolithophores preferred phosphate limitation, interacts with pCO2 on particulate carbon accumulation. Second, how direct physiological responses on the cellular level translate into a net population response. In this study cultures of Emiliania huxleyi were full-factorially exposed to two different N:P ratios (Redfield and high N:P) and three different pCO2 levels. Effects on net population particulate inorganic and organic carbon (PIC, POC) were measured after E. huxleyi cultures reached stationary phase. Thereby cell sizes and total cell abundance were taken into account. Corresponding to literature results show a significant negative cellular PIC and POC response which, however, was strongest under high N:P ratio. In contrast, net population PIC and POC accumulation was significantly attenuated under high N:P ratio. We suggest that less cellular nutrient accumulation allowed for higher cell abundances which compensated for the strong negative cellular PIC and POC response to pCO2 on the population level. Moreover, the design of this study also allowed following natural alteration of carbon chemistry through changing DIC and alkalinity. Our results suggest that at high initial pCO2 natural alteration of pCO2 during the experimental runtime was regulated by algal biomass. In contrast, at low initial pCO2 the PIC/POC ratio was responsible for changes in pCO2. Our results point to the fact that the physiological (i.e. cellular) PIC and POC response to ocean acidification cannot be linearly extrapolated to total population response and thus carbon export. It is therefore recommended to consider effects of nutrient limitation on cell physiology and translate these to net population carbon

  11. Adaptation of a Saccharomyces cerevisiae strain to high copper concentrations.

    PubMed

    Sarais, I; Manzano, M; De Bertoldi, M; Romandini, P; Beltramini, M; Salvato, B; Rocco, G P

    1994-07-01

    A strain of Saccharomyces cerevisiae has been adapted to increasing concentrations of copper at two different pH values. The growth curve at pH 5.5 is characterized by a time generation increasing with the amount of added copper. A significant decrease of cell volume as compared with the control is also observed. At pH 3 the cells grow faster than at pH 5.5 and resist higher copper concentrations (3.8 against 1.2 mM). Experimental evidence indicates that, after copper treatment, the metal is not bound to the cell wall, but is localized intracellularly. A significant precipitation of copper salts in the medium was observed only at pH 5.5. Increased levels of superoxide dismutase (SOD) activity were observed in copper-treated cells and which persisted after 20 subsequent inocula in a medium without added metal. On the contrary, catalase activity was not stimulated by copper treatment and, hence, not correlated with SOD levels. The mechanism of copper resistance, therefore, probably involves a persistent induction of SOD, but not of catalase, and it is strongly pH-dependent. PMID:8043987

  12. Anthocyanin-rich Phytochemicals from Aronia Fruits Inhibit Visceral Fat Accumulation and Hyperglycemia in High-fat Diet-induced Dietary Obese Rats.

    PubMed

    Takahashi, Azusa; Shimizu, Hisae; Okazaki, Yukako; Sakaguchi, Hirohide; Taira, Toshio; Suzuki, Takashi; Chiji, Hideyuki

    2015-01-01

    Aronia fruits (chokeberry: Aronia melanocarpa E.) containing phenolic phytochemicals, such as cyanidin 3-glycosides and chlorogenic acid, have attracted considerable attention because of their potential human health benefits in humans including antioxidant activities and ability to improved vision. In the present study, the effects of anthocyanin-rich phytochemicals from aronia fruits (aronia phytochemicals) on visceral fat accumulation and fasting hyperglycemia were examined in rats fed a high-fat diet (Experiment 1). Total visceral fat mass was significantly lower in rats fed aronia phytochemicals than that in both the control group and bilberry phytochemicals-supplemented rats (p < 0.05). Moreover, perirenal and epididymal adipose tissue mass in rats fed aronia phytochemicals was significantly lower than that in both the control and bilberry phytochemicals group. Additionally, the mesenteric adipose tissue mass in aronia phytochemicals-fed rats was significantly low (p < 0.05). Furthermore, the fasting blood glucose levels significantly decreased in rats fed aronia phytochemicals for 4 weeks compared to that in the control rats (p < 0.05). Therefore, we investigated the effects of phytochemicals on postprandial hyperlipidemia after corn oil loading in rats, pancreatic lipase activity in vitro, and the plasma glycemic response after sucrose loading in order to elucidate the preventive factor of aronia phytochemical on visceral fat accumulation. In the oral corn oil tolerance tests (Experiment 2), aronia phytochemicals significantly inhibited the increases in plasma triglyceride levels, with a half-maximal inhibitory concentration (IC(50)) of 1.50 mg/mL. However, the inhibitory activity was similar to that of bilberry and tea catechins. In the sucrose tolerance tests (Experiment 3), aronia phytochemicals also significantly inhibited the increases in blood glucose levels that were observed in the control animals (p < 0.05). These results suggest that anthocyanin

  13. Silicic magma accumulation beneath Mount Mazama, Oregon, 71 ka to 24 ka constrained by SHRIMP measurements of dissolved volatile concentrations in melt inclusions

    NASA Astrophysics Data System (ADS)

    Wright, H. M.; Bacon, C. R.; Vazquez, J. A.; Sisson, T. W.

    2010-12-01

    Dissolved volatile contents of melt inclusions trapped in pyroxene and plagioclase crystals from 7 silicic eruptions preceding the climactic ~7.7 ka Mazama eruption were measured by SIMS with the Stanford-USGS SHRIMP-RG. Melt inclusions in crystals were intersected, polished, and crystals were mounted in indium in Al mounts. A 1.2-3.0 nA (depending on the session), O2- primary beam was accelerated and focused to a 15-25 μm spot on the sample surface, which generated positive secondary ions of analyzed Li, Be, B, C, OH, F, Mg, Si, SiH, S, Cl, Ca, AlO, KO, Rb, and Sr. Measurements were made at high mass resolution (6000-7000). Trace element and volatile concentrations were calculated using a best-fit regression to count rate ratios (normalized to 30Si) vs. variable known concentrations in experimental and natural rhyolite glass standards. Pumiceous samples were chosen from dacitic to rhyodacitic eruptive deposits, consisting of the 71ka dacite of Pumice Castle, 70ka dacite below Llao Rock, 50ka dacite of the Watchman, 35ka dacite of Munson Valley, 35ka Williams Crater tephra, 27ka Redcloud Cliff rhyodacite, and 24ka andesite S of Bear Bluff. Melt inclusions are abundant in spongy, mineral-inclusion-rich interiors of pyroxene crystals in early (71-35ka) eruptive deposits and are less abundant throughout pyroxenes from later eruptions (35-24ka) and in plagioclase crystals. Over the entire time interval, most trace element and volatile concentrations remain approximately constant between melt inclusion populations. However, there are some variations in water and carbon dioxide concentration. A large proportion of inclusions in the smaller eruptive deposits (0.003-0.4 km3) of the dacite of the Watchman, dacite of Munson Valley, and Williams Crater tephra have low water contents, ~1 wt% H2O, corresponding to a saturation pressure of 25MPa, or ~1km depth (at 870°, approximate average temperature for these deposits, e.g., Druitt and Bacon, Contrib Mineral Petrol 1989

  14. Suppression of Ripening-Associated Gene Expression in Tomato Fruits Subjected to a High CO2 Concentration.

    PubMed Central

    Rothan, C.; Duret, S.; Chevalier, C.; Raymond, P.

    1997-01-01

    High concentrations of CO2 block or delay the ripening of fruits. In this study we investigated the effects of high CO2 on ripening and on the expression of stress- and ripening-inducible genes in cherry tomato (Lycopersicon esculentum Mill.) fruit. Mature-green tomato fruits were submitted to a high CO2 concentration (20%) for 3 d and then transferred to air. These conditions effectively inhibited ripening-associated color changes and ethylene production, and reduced the protein content. No clear-cut effect was observed on the expression of two proteolysis-related genes, encoding polyubiquitin and ubiquitin-conjugating enzyme E2, respectively. Exposure of fruit to high CO2 also resulted in the strong induction of two genes encoding stress-related proteins: a ripening-regulated heat-shock protein and glutamate decarboxylase. Induction of these two genes indicated that high CO2 had a stress effect, most likely through cytosolic acidification. In addition, high CO2 blocked the accumulation of mRNAs for genes involved in the main ripening-related changes: ethylene synthesis (1-aminocyclopropane-1-carboxylic acid synthase and 1-aminocyclopropane-1-carboxylic acid oxidase), color (phytoene synthase), firmness (polygalacturonase), and sugar accumulation (acid invertase). The expression of ripening-specific genes was affected by CO2 regardless of whether their induction was ethylene- or development-dependent. It is proposed that the inhibition of tomato fruit ripening by high CO2 is due, in part, to the suppression of the expression of ripening-associated genes, which is probably related to the stress effect exerted by high CO2. PMID:12223703

  15. High-quality and high-purity homoepitaxial diamond (100) film growth under high oxygen concentration condition

    SciTech Connect

    Teraji, Tokuyuki

    2015-09-21

    Defect formation during diamond homoepitaxial growth was sufficiently inhibited by adding oxygen simultaneously in the growth ambient with high concentration of 2%. A 30-μm thick diamond films with surface roughness of <2 nm were homoepitaxially deposited on the (100) diamond single crystal substrates with reasonable growth rate of approximately 3 μm h{sup −1} under the conditions of higher methane concentration of 10%, higher substrate temperature of ∼1000 °C, and higher microwave power density condition of >100 W cm{sup −3}. Surface characteristic patterns moved to an identical direction with growth thickness, indicating that lateral growth was dominant growth mode. High chemical purity represented by low nitrogen concentration of less than 1 ppb and the highest {sup 12}C isotopic ratio of 99.998% of the obtained homoepitaxial diamond (100) films suggest that the proposed growth condition has high ability of impurity control.

  16. Constructing the integral concept on the basis of the idea of accumulation: suggestion for a high school curriculum

    NASA Astrophysics Data System (ADS)

    Kouropatov, Anatoli; Dreyfus, Tommy

    2013-07-01

    Students have a tendency to see integral calculus as a series of procedures with associated algorithms and many do not develop a conceptual grasp giving them the desirable versatility of thought. Thus, instead of a proceptual view of the symbols in integration, they have, at best, a process-oriented view. On the other hand, it is not surprising that many students find concepts such as the integral difficult when they are unable to experience these processes directly in the classroom. With a view towards improving this situation, constructing the integral concept on the basis of the idea of accumulation has been proposed (Educ Stud Math. 1994;26:229-274; Integral as accumulation: a didactical perspective for school mathematics; Thessaloniki: PME; 2009. p. 417-424). In this paper, we discuss a curriculum that is based on this idea and a design for curriculum materials that are intended to develop an improved cognitive base for a flexible proceptual understanding of the integral and integration in high school. The main focus is on how we (mathematics teachers and mathematics educators) might teach the integral concept in order to help high school students to construct meaningful knowledge alongside acquiring technical abilities.

  17. Reusable chelating resins concentrate metal ions from highly dilute solutions

    NASA Technical Reports Server (NTRS)

    Bauman, A. J.; Weetal, H. H.; Weliky, N.

    1966-01-01

    Column chromatographic method uses new metal chelating resins for recovering heavy-metal ions from highly dilute solutions. The absorbed heavy-metal cations may be removed from the chelating resins by acid or base washes. The resins are reusable after the washes are completed.

  18. High Concentrations of Ketocarotenoids in Hepatic Mitochondria of Haemorhous mexicanus.

    PubMed

    Ge, Zhiyuan; Johnson, James D; Cobine, Paul A; McGraw, Kevin J; Garcia, Rosana; Hill, Geoffrey E

    2015-01-01

    Vertebrates cannot synthesize carotenoid pigments de novo, so to produce carotenoid-based coloration they must ingest carotenoids. Most songbirds that deposit red carotenoids in feathers, bills, eyes, or skin ingest only yellow or orange dietary pigments, which they oxidize to red pigments via a ketolation reaction. It has been hypothesized that carotenoid ketolation occurs in the liver of vertebrates, but this hypothesis remains to be confirmed. To better understand the role of hepatocytes in the production of ketolated carotenoids in songbirds, we measured the carotenoid content of subcellular components of hepatocytes from wild male house finches (Haemorhous mexicanus) that were molting red, ketocarotenoid-containing feathers (e.g., 3-hydroxy-echinenone). We homogenized freshly collected livers of house finches and isolated subcellular fractions, including mitochondria. We found the highest concentration of ketocarotenoids in the mitochondrial fraction. These observations are consistent with the hypothesis that carotenoid pigments are oxidized on or within hepatic mitochondria, esterified, and then transported to the Golgi apparatus for secretory processing. PMID:26052641

  19. Deep Sea Memory of High Atmospheric CO2 Concentration

    NASA Astrophysics Data System (ADS)

    Mathesius, Sabine; Hofmann, Matthias; Caldeira, Ken; Schellnhuber, Hans Joachim

    2015-04-01

    Carbon dioxide removal (CDR) from the atmosphere has been proposed as a powerful measure to mitigate global warming and ocean acidification. Planetary-scale interventions of that kind are often portrayed as "last-resort strategies", which need to weigh in if humankind keeps on enhancing the climate-system stock of CO2. Yet even if CDR could restore atmospheric CO2 to substantially lower concentrations, would it really qualify to undo the critical impacts of past emissions? In the study presented here, we employed an Earth System Model of Intermediate Complexity (EMIC) to investigate how CDR might erase the emissions legacy in the marine environment, focusing on pH, temperature and dissolved oxygen. Against a background of a world following the RCP8.5 emissions path ("business-as-usual") for centuries, we simulated the effects of two massive CDR interventions with CO2 extraction rates of 5 GtC yr-1 and 25 GtC yr-1, respectively, starting in 2250. We found that the 5 GtC yr-1 scheme would have only minor ameliorative influence on the oceans, even after several centuries of application. By way of contrast, the extreme 25 GtC yr-1 scheme eventually leads to tangible improvements. However, even with such an aggressive measure, past CO2 emissions leave a substantial legacy in the marine environment within the simulated period (i.e., until 2700). In summary, our study demonstrates that anthropogenic alterations of the oceans, caused by continued business-as-usual emissions, may not be reversed on a multi-centennial time scale by the most aspirational geoengineering measures. We also found that a transition from the RCP8.5 state to the state of a strong mitigation scenario (RCP2.6) is not possible, even under the assumption of extreme extraction rates (25 GtC yr-1). This is explicitly demonstrated by simulating additional scenarios, starting CDR already in 2150 and operating until the atmospheric CO2 concentration reaches 280 ppm and 180 ppm, respectively. The simulated

  20. Response of a Concentrated Monoclonal Antibody Formulation to High Shear

    PubMed Central

    Bee, Jared S.; Stevenson, Jennifer L.; Mehta, Bhavya; Svitel, Juraj; Pollastrini, Joey; Platz, Robert; Freund, Erwin; Carpenter, John F.

    2009-01-01

    There is concern that shear could cause protein unfolding or aggregation during commercial biopharmaceutical production. In this work we exposed two concentrated immunoglobulin-G1 (IgG1) monoclonal antibody (mAb, at >100 mg/mL) formulations to shear rates of between 20,000 and 250,000 s-1 for between 5 minutes and 30 ms using a parallel-plate and capillary rheometer respectively. The maximum shear and force exposures were far in excess of those expected during normal processing operations (20,000 s-1 and 0.06 pN respectively). We used multiple characterization techniques to determine if there was any detectable aggregation. We found that shear alone did not cause aggregation, but that prolonged exposure to shear in the stainless steel parallel-plate rheometer caused a very minor reversible aggregation (<0.3%). Additionally, shear did not alter aggregate populations in formulations containing 17% preformed heat-induced aggregates of a mAb. We calculate that that the forces applied to a protein by production shear exposures (<0.06 pN) are small when compared with the 140 pN force expected at the air-water interface or the 20 to 150 pN forces required to mechanically unfold proteins described in the atomic force microscope (AFM) literature. Therefore, we suggest that in many cases air-bubble entrainment, adsorption to solid surfaces (with possible shear synergy), contamination by particulates, or pump cavitation stresses could be much more important causes of aggregation than shear exposure during production. PMID:19370772

  1. View looking northwest toward HIghGrade Ore Bin and Concentrate Bin ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View looking northwest toward HIgh-Grade Ore Bin and Concentrate Bin - Kennecott Copper Corporation, Concentration Mill, On Copper River & Northwestern Railroad, Kennicott, Valdez-Cordova Census Area, AK

  2. Redirection of metabolic flux for high levels of omega-7 monounsaturated fatty acid accumulation in camelina seeds.

    PubMed

    Nguyen, Huu Tam; Park, Hyunwoo; Koster, Karen L; Cahoon, Rebecca E; Nguyen, Hanh T M; Shanklin, John; Clemente, Thomas E; Cahoon, Edgar B

    2015-01-01

    Seed oils enriched in omega-7 monounsaturated fatty acids, including palmitoleic acid (16:1∆9) and cis-vaccenic acid (18:1∆11), have nutraceutical and industrial value for polyethylene production and biofuels. Existing oilseed crops accumulate only small amounts (<2%) of these novel fatty acids in their seed oils. We demonstrate a strategy for enhanced production of omega-7 monounsaturated fatty acids in camelina (Camelina sativa) and soybean (Glycine max) that is dependent on redirection of metabolic flux from the typical ∆9 desaturation of stearoyl (18:0)-acyl carrier protein (ACP) to ∆9 desaturation of palmitoyl (16:0)-acyl carrier protein (ACP) and coenzyme A (CoA). This was achieved by seed-specific co-expression of a mutant ∆9-acyl-ACP and an acyl-CoA desaturase with high specificity for 16:0-ACP and CoA substrates, respectively. This strategy was most effective in camelina where seed oils with ~17% omega-7 monounsaturated fatty acids were obtained. Further increases in omega-7 fatty acid accumulation to 60-65% of the total fatty acids in camelina seeds were achieved by inclusion of seed-specific suppression of 3-keto-acyl-ACP synthase II and the FatB 16:0-ACP thioesterase genes to increase substrate pool sizes of 16:0-ACP for the ∆9-acyl-ACP desaturase and by blocking C18 fatty acid elongation. Seeds from these lines also had total saturated fatty acids reduced to ~5% of the seed oil versus ~12% in seeds of nontransformed plants. Consistent with accumulation of triacylglycerol species with shorter fatty acid chain lengths and increased monounsaturation, seed oils from engineered lines had marked shifts in thermotropic properties that may be of value for biofuel applications. PMID:25065607

  3. High doses of intravenously administered titanium dioxide nanoparticles accumulate in the kidneys of rainbow trout but with no observable impairment of renal function.

    PubMed

    Scown, Tessa M; van Aerle, Ronny; Johnston, Blair D; Cumberland, Susan; Lead, Jamie R; Owen, Richard; Tyler, Charles R

    2009-06-01

    Our recent work suggests limited uptake of unstabilized metal oxide nanoparticles via water into fish, however, some other studies have indicated such exposures can induce oxidative stress. To investigate tissue distribution and toxicity of titanium dioxide (TiO(2)) nanoparticles that may enter into fish, we conducted a series of injection studies. Rainbow trout (Oncorhynchus mykiss) were intravenously injected with 100 microg TiO(2) nanoparticles and the content of titanium in blood, brain, gills, liver, and kidney quantified at time points between 6 h and 90 days using inductively coupled plasma optical emission spectroscopy. Injected Ti was concentrated in the kidneys and remained there up to 21 days, however, there was evidence of clearance of TiO(2) at 90 days. Ti accumulation in the liver was 15 times lower than in the kidney with no apparent clearance. Using TEM we showed nanoparticles were localized in tissue vesicles surrounding the kidney tubules. In a second injection study, rainbow trout were injected with 100 microg TiO(2) and plasma samples from individual fish analyzed for total protein and creatinine content at time points between 6 h and 21 days to assess for possible effects on kidney function. No effect of TiO(2) on total plasma protein content or creatinine concentrations were found indicating that neither urine production nor glomerular filtration rate were affected. We conclude that in trout upon a single high dose exposure of TiO(2) nanoparticles via the bloodstream, TiO(2) accumulates in the kidneys but has minimal effect on kidney function. PMID:19332650

  4. 1-FFT amino acids involved in high DP inulin accumulation in Viguiera discolor

    PubMed Central

    De Sadeleer, Emerik; Vergauwen, Rudy; Struyf, Tom; Le Roy, Katrien; Van den Ende, Wim

    2015-01-01

    Fructans are important vacuolar reserve carbohydrates with drought, cold, ROS and general abiotic stress mediating properties. They occur in 15% of all flowering plants and are believed to display health benefits as a prebiotic and dietary fiber. Fructans are synthesized by specific fructosyltransferases and classified based on the linkage type between fructosyl units. Inulins, one of these fructan types with β(2-1) linkages, are elongated by fructan:fructan 1-fructosyltransferases (1-FFT) using a fructosyl unit from a donor inulin to elongate the acceptor inulin molecule. The sequence identity of the 1-FFT of Viguiera discolor (Vd) and Helianthus tuberosus (Ht) is 91% although these enzymes produce distinct fructans. The Vd 1-FFT produces high degree of polymerization (DP) inulins by preferring the elongation of long chain inulins, in contrast to the Ht 1-FFT which prefers small molecules (DP3 or 4) as acceptor. Since higher DP inulins have interesting properties for industrial, food and medical applications, we report here on the influence of two amino acids on the high DP inulin production capacity of the Vd 1-FFT. Introducing the M19F and H308T mutations in the active site of the Vd 1-FFT greatly reduces its capacity to produce high DP inulin molecules. Both amino acids can be considered important to this capacity, although the double mutation had a much higher impact than the single mutations. PMID:26322058

  5. High relative air humidity influences mineral accumulation and growth in iron deficient soybean plants

    PubMed Central

    Roriz, Mariana; Carvalho, Susana M. P.; Vasconcelos, Marta W.

    2014-01-01

    Iron (Fe) deficiency chlorosis (IDC) in soybean results in severe yield losses. Cultivar selection is the most commonly used strategy to avoid IDC but there is a clear interaction between genotype and the environment; therefore, the search for quick and reliable tools to control this nutrient deficiency is essential. Several studies showed that relative humidity (RH) may influence the long distance transport of mineral elements and the nutrient status of plants. Thus, we decided to analyze the response of an “Fe-efficient” (EF) and an “Fe-inefficient” (INF) soybean accession grown under Fe-sufficient and deficient conditions under low (60%) and high (90%) RH, evaluating morphological, and physiological parameters. Furthermore, the mineral content of different plant organs was analyzed. Our results showed beneficial effects of high RH in alleviating IDC symptoms as seen by increased SPAD values, higher plant dry weight (DW), increased plant height, root length, and leaf area. This positive effect of RH in reducing IDC symptoms was more pronounced in the EF accession. Also, Fe content in the different plant organs of the EF accession grown under deficient conditions increased with RH. The lower partitioning of Fe to roots and stems of the EF accessions relative to dry matter also supported our hypothesis, suggesting a greater capacity of this accession in Fe translocation to the aerial parts under Fe deficient conditions, when grown under high RH. PMID:25566297

  6. 1-FFT amino acids involved in high DP inulin accumulation in Viguiera discolor.

    PubMed

    De Sadeleer, Emerik; Vergauwen, Rudy; Struyf, Tom; Le Roy, Katrien; Van den Ende, Wim

    2015-01-01

    Fructans are important vacuolar reserve carbohydrates with drought, cold, ROS and general abiotic stress mediating properties. They occur in 15% of all flowering plants and are believed to display health benefits as a prebiotic and dietary fiber. Fructans are synthesized by specific fructosyltransferases and classified based on the linkage type between fructosyl units. Inulins, one of these fructan types with β(2-1) linkages, are elongated by fructan:fructan 1-fructosyltransferases (1-FFT) using a fructosyl unit from a donor inulin to elongate the acceptor inulin molecule. The sequence identity of the 1-FFT of Viguiera discolor (Vd) and Helianthus tuberosus (Ht) is 91% although these enzymes produce distinct fructans. The Vd 1-FFT produces high degree of polymerization (DP) inulins by preferring the elongation of long chain inulins, in contrast to the Ht 1-FFT which prefers small molecules (DP3 or 4) as acceptor. Since higher DP inulins have interesting properties for industrial, food and medical applications, we report here on the influence of two amino acids on the high DP inulin production capacity of the Vd 1-FFT. Introducing the M19F and H308T mutations in the active site of the Vd 1-FFT greatly reduces its capacity to produce high DP inulin molecules. Both amino acids can be considered important to this capacity, although the double mutation had a much higher impact than the single mutations. PMID:26322058

  7. Atomic physics and synchrotron radiation: The production and accumulation of highly charged ions

    NASA Astrophysics Data System (ADS)

    Johnson, B. M.; Meron, M.; Agagu, A.; Jones, K. W.

    1987-04-01

    Synchrotron radiation can be used to produce highly-charged ions, and to study photoexcitation and photoionization for ions of virtually any element in the periodic table. To date, with few exceptions, atomic physics studies have been limited to rare gases and a few metal vapors, and to photoexcitation energies in the VUV region of the electromagnetic spectrum. These limitations can now be overcome using photons produced by high-brightness synchrotron storage rings, such as the X-ray ring at the National Synchrotron Light Source (NSLS) at Brookhaven. Furthermore, calculations indicate that irradiation of an ion trap with an intense energetic photon beam will result in a viable source of highly-charged ions that can be given the name PHOBIS: the photon beam ion source. Promising results, which encourage the wider systematic use of synchrotron radiation in atomic physics research, have been obtained in recent experiments on VUV photoemission and the production and storage of multiply-charged ions. An overview of the field, current plans, and future possibilities will be presented.

  8. Nitrogen Accumulation and Partitioning in High Arctic Tundra from Extreme Atmospheric N Deposition Events

    NASA Astrophysics Data System (ADS)

    Phoenix, G. K.; Osborn, A.; Blaud, A.; Press, M. C.; Choudhary, S.

    2013-12-01

    Arctic ecosystems are threatened by pollution from extreme atmospheric nitrogen (N) deposition events. These events occur from the long-range transport of reactive N from pollution sources at lower latitudes and can deposit up to 80% of the annual N deposition in just a few days. To date, the fate and impacts of these extreme pollutant events has remained unknown. Using a field simulation study, we undertook the first assessment of the fate of acutely deposited N on arctic tundra. Extreme N deposition events were simulated on field plots at Ny-Ålesund, Svalbard (79oN) at rates of 0, 0.04, 0.4 and 1.2 g N m-2 yr-1 applied as NH4NO3 solution over 4 days, with 15N tracers used in the second year to quantify the fate of the deposited N in the plant, soil, microbial and leachate pools. Separate applications of 15NO3- and 15NH4+ were also made to determine the importance of N form in the fate of N. Recovery of the 15N tracer at the end of the first growing season approached 100% of the 15N applied irrespective of treatment level, demonstrating the considerable capacity of High Arctic tundra to capture pollutant N from extreme deposition events. Most incorporation of the 15N was found in bryophytes, followed by the dominant vascular plant (Salix polaris) and the microbial biomass of the soil organic layer. Total recovery remained high in the second growing season (average of 90%), indicating highly conservative N retention. Between the two N forms, recovery of 15NO3- and 15NH4+ were equal in the non-vascular plants, whereas in the vascular plants (particularly Salix polaris) recovery of 15NO3- was four times higher than of 15NH4+. Overall, these findings show that High Arctic tundra has considerable capacity to capture and retain the pollutant N deposited in acute extreme deposition events. Given they can represent much of the annual N deposition, extreme deposition events may be more important than increased chronic N deposition as a pollution source. Furthermore

  9. Overexpression of UV-DAMAGED DNA BINDING PROTEIN 1 links plant development and phytonutrient accumulation in high pigment-1 tomato

    PubMed Central

    Azari, Raviv; Reuveni, Moshe; Evenor, Dalia; Nahon, Sahadia; Shlomo, Haviva; Chen, Lea; Levin, Ilan

    2010-01-01

    Fruits of tomato plants carrying the high pigment-1 mutations hp-1 and hp-1w are characterized by an increased number of plastids coupled with enhanced levels of functional metabolites. Unfortunately, hp-1 mutant plants are also typified by light-dependent retardation in seedling and whole-plant growth and development, which limits their cultivation. These mutations were mapped to the gene encoding UV-DAMAGED DNA BINDING PROTEIN 1 (DDB1) and, recently, fruit-specific RNA interference studies have demonstrated an increased number of plastids and enhanced carotenoid accumulation in the transgenic tomato fruits. However, whole-plant overexpression of DDB1, required to substantiate its effects on seedling and plant development and to couple them with fruit phenotypes, has heretofore been unsuccessful. In this study, five transgenic lines constitutively overexpressing normal DDB1 in hp-1 mutant plants were analysed. Eleven-day-old seedlings, representing these lines, displayed up to ∼73- and ∼221-fold overexpression of the gene in hypocotyls and cotyledons, respectively. This overexpression resulted in statistically significant reversion to the non-mutant developmental phenotypes, including more than a full quantitative reversion. This reversion of phenotypes was generally accompanied by correlated responses in chlorophyll accumulation and altered expression of selected light signalling genes: PHYTOCHROME A, CRYPTOCHROME 1, ELONGATED HYPOCOTYL 5, and the gene encoding CHLOROPHYLL A/B-BINDING PROTEIN 4. Cumulatively, these results provide the missing link between DDB1 and its effects on tomato plant development. PMID:20566564

  10. Fenugreek seed extract inhibit fat accumulation and ameliorates dyslipidemia in high fat diet-induced obese rats.

    PubMed

    Kumar, Parveen; Bhandari, Uma; Jamadagni, Shrirang

    2014-01-01

    This study investigated the inhibitory effect of aqueous extract of Trigonella foenum-graecum seeds (AqE-TFG) on fat accumulation and dyslipidemia in high fat diet- (HFD-) induced obese rats. Female Wistar rats were fed with HFD ad libitum, and the rats on HFD were treated orally with AqE-TFG or orlistat ((HFD for 28 days+AqE-TFG (0.5 and 1.0 g/kg) or orlistat (10 mg/kg) from day 8 to 28), respectively. Treatment with AqE-TFG produced significant reduction in body weight gain, body mass index (BMI), white adipose tissue (WAT) weights, blood glucose, serum insulin, lipids, leptin, lipase, and apolipoprotein-B levels and elevation in adiponectin levels. AqE-TFG improved serum aspartate amino transferase (AST), alanine amino transferase (ALT), and lactate dehydrogenase (LDH) levels. AqE-TFG treatment reduced the hepatic and cardiac thiobarbituric acid reactive substances (TBARS) and elevated the antioxidant enzyme (glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT)) levels. In addition, liver and uterine WAT lipogenic enzyme (fatty acid synthetase (FAS) and glucose-6-phosphate dehydrogenase (G6PD)) activities were restored towards normal levels. These findings demonstrated the preventive effect of AqE-TFG on fat accumulation and dyslipidemia, due to inhibition of impaired lipid digestion and absorption, in addition to improvement in glucose and lipid metabolism, enhancement of insulin sensitivity, increased antioxidant defense, and downregulation of lipogenic enzymes. PMID:24868532

  11. Targeting of the polyhydroxybutyrate biosynthetic pathway to the plastids of Arabidopsis thaliana results in high levels of polymer accumulation

    SciTech Connect

    Nawrath, C.; Poirier, Y.; Somerville, C. )

    1994-12-20

    In the bacterium Alcaligenes eutrophus, three genes encode the enzymes necessary to catalyze the synthesis of poly[(R)-(-)-3-hydroxybutyrate] (PHB) from acetyl-CoA. In order to target these enzymes into the plastids of higher plants, the genes were modified by addition of DNA fragments encoding a pea chloroplast transit peptide, a constitutive plant promoter, and a poly(A) addition sequence. Each of the modified bacterial genes was introduced into Arabidopsis thaliana by Agrobacterium-mediated transformation, and plants containing all three genes were obtained by sexual crosses. These plans accumulated PHB up to 14% of the dry weight as 0.2- to 0.7-[mu]m granules within plastids. In contrast to earlier experiments in which expression of the PHB biosynthetic pathway in the cytoplasm led to a deleterious effect on growth, expression of the PHB biosynthetic pathway in plastids had no obvious effect on the growth or fertility of the transgenic plants and resulted in a 100-fold increase in the amount of PHB in higher plants. The high level of PHB accumulation also suggests that the synthesis of plastid acetyl-CoA is regulated by a mechanism which responds to metabolic demand. 20 refs., 6 figs.

  12. Synthesis and characterization of high-quality PbI2 nanopowders from depleted SLA accumulator anode and cathode

    NASA Astrophysics Data System (ADS)

    Malevu, T. D.; Ocaya, R. O.; Tshabalala, K. G.; Fernandez, C.

    2016-07-01

    High-quality lead iodide (PbI2) nanoparticles were synthesized from both anode and cathode of a discarded sealed lead-acid accumulator as starting materials. The structure, morphology, chemical composition and optical properties of washed PbI2 were investigated using X-ray diffraction, field emission scanning electron microscope, photoluminescence and energy-dispersive X-ray spectrometer. The XRD measurements indicated the presence of pure hexagonal PbI2 nanoparticles. Application of the Scherrer equation indicates crystal sizes between 13.703 and 14.320 nm. SEM indicated the presence of spherical particle agglomerations between 1.5 and 3.5 \\upmum in diameter. The measured band gap using two methods was consistent at 2.75 eV. EDS results suggest the absence of impurities in the synthesized nanoparticles. The overall results suggest that discarded sealed lead-acid accumulators can source pure hexagonal-phase lead iodide nanoparticles with potential applications in perovskite solar cells. The novelty aspect is that this approach has not been previously reported.

  13. Synthesis and characterization of high-quality PbI2 nanopowders from depleted SLA accumulator anode and cathode

    NASA Astrophysics Data System (ADS)

    Malevu, T. D.; Ocaya, R. O.; Tshabalala, K. G.; Fernandez, C.

    2016-07-01

    High-quality lead iodide (PbI2) nanoparticles were synthesized from both anode and cathode of a discarded sealed lead-acid accumulator as starting materials. The structure, morphology, chemical composition and optical properties of washed PbI2 were investigated using X-ray diffraction, field emission scanning electron microscope, photoluminescence and energy-dispersive X-ray spectrometer. The XRD measurements indicated the presence of pure hexagonal PbI2 nanoparticles. Application of the Scherrer equation indicates crystal sizes between 13.703 and 14.320 nm. SEM indicated the presence of spherical particle agglomerations between 1.5 and 3.5 μm in diameter. The measured band gap using two methods was consistent at 2.75 eV. EDS results suggest the absence of impurities in the synthesized nanoparticles. The overall results suggest that discarded sealed lead-acid accumulators can source pure hexagonal-phase lead iodide nanoparticles with potential applications in perovskite solar cells. The novelty aspect is that this approach has not been previously reported.

  14. Development of semi-automated system for preparation of (188)Re aqueous solutions of high and reproducible activity concentrations.

    PubMed

    Jäckel, B; Cripps, R; Güntay, S; Bruchertseifer, H

    2005-09-01

    A semi-automated system has been developed for elution and concentration of the (188)Re-eluate from 111 GBq (3 Ci) (188)W/(188)Re-generators to provide a dissolved beta-source of high (188)Re-activity per unit volume. The elution progress and concentration were precisely and continuously monitored by use of collimated diode detectors. By using ion exchange cartridges, small eluate volumes (2-3 ml) of maximum 40 GBq, (188)Re/ml activity concentration were routinely prepared. The concentrated (188)Re solutions were used to beta-irradiate aqueous suspensions and solutions of iodine species to evaluate a simulation of the extent of radiolytic decomposition of chemical species (AgI and CH(3)I) expected to accumulate in the containment sump of a nuclear reactor in the event of a severe accident with reproducible dose rates of up to 0.4 Gys(-1). Results have shown that AgI colloidal particles decompose to varying extents, depending on conditions, and in proportion to their initial mass, which indicates surface oxidation. Experiments have also confirmed CH(3)I decomposition in proportion to initial aqueous concentration. PMID:15963728

  15. Elevated CO2-Mitigation of High Temperature Stress Associated with Maintenance of Positive Carbon Balance and Carbohydrate Accumulation in Kentucky Bluegrass

    PubMed Central

    Huang, Bingru

    2014-01-01

    Elevated CO2 concentration may promote plant growth while high temperature is inhibitory for C3 plant species. The interactive effects of elevated CO2 and high temperatures on C3 perennial grass growth and carbon metabolism are not well documented. Kentucky bluegrass (Poa pratensis) plants were exposed to two CO2 levels (400 and 800 μmol mol−1) and five temperatures (15/12, 20/17, 25/22, 30/27, 35/32°C, day/night) in growth chambers. Increasing temperatures to 25°C and above inhibited leaf photosynthetic rate (Pn) and shoot and root growth, but increased leaf respiration rate (R), leading to a negative carbon balance and a decline in soluble sugar content under ambient CO2. Elevated CO2 did not cause shift of optimal temperatures in Kentucky bluegrass, but promoted Pn, shoot and root growth under all levels of temperature (15, 20, 25, 30, and 35°C) and mitigated the adverse effects of severe high temperatures (30 and 35°C). Elevated CO2-mitigation of adverse effects of high temperatures on Kentucky bluegrass growth could be associated with the maintenance of a positive carbon balance and the accumulation of soluble sugars and total nonstructural carbohydrates through stimulation of Pn and suppression of R and respiratory organic acid metabolism. PMID:24662768

  16. Rapid transport and high accumulation of amorphous silica in the Congo deep-sea fan: A preliminary budget

    NASA Astrophysics Data System (ADS)

    Raimonet, Mélanie; Ragueneau, Olivier; Jacques, Vincent; Corvaisier, Rudolph; Moriceau, Brivaëla; Khripounoff, Alexis; Pozzato, Lara; Rabouille, Christophe

    2015-01-01

    Mechanisms controlling the transfer and retention of silicon (Si) along continental margins are poorly understood, but play a major role in the functioning of coastal ecosystems and the oceanic biological pump of carbon. Deep-sea fans are well recognized as carbon sink spots, but we lack knowledge about the importance of the fans in the global Si cycle. Here, we provide a first estimate of the role played by the Congo deep-sea fan, one of the biggest in the world, in the Si cycle. Sediment cores sampled in the deep-sea fan were analyzed to build a Si mass balance. An exceptionally high accumulation rate of amorphous silica aSiO2 (2.29 ± 0.58 mol Si m- 2 y- 1) was found, due to a high sedimentation rate and the presence of aluminum in the sediments. Although favored by bioirrigation, recycling fluxes remained low (0.3 mol Si m- 2 y- 1) and reconstructed input fluxes could only be explained by lateral inputs coming from the canyon. Preliminary calculations show that the rapid transport of aSiO2 through the canyon and the excellent preservation efficiency in the sediments imply that 50% of aSiO2 river inputs from the Congo River accumulate annually in the deep-sea fan. Si:C ratios in deep-sea fan sediments were very low (0.2) and only three times as high as those measured in the river itself, which suggests that material from the river and the continental shelf was delivered directly through the canyon, with very little time for Si and C cycle decoupling to take place.

  17. Effect of imprecise lag time and high-frequency attenuation on surface-atmosphere exchange fluxes determined with the relaxed eddy accumulation method

    NASA Astrophysics Data System (ADS)

    Moravek, A.; Trebs, I.; Foken, T.

    2013-09-01

    eddy accumulation (REA) systems that employ one single long inlet tube are prone to measurement uncertainties caused by (a) an imprecisely determined lag time between the change of sign in the vertical wind velocity and the switching of the splitter valves and (b) attenuation of high-frequency concentration fluctuations in the tube flow. However, there is currently no commonly applied procedure to address these uncertainties. In this study, we first evaluated the lag time error of the volume flow, mass flow, and cross-correlation method (online and offline) and experimentally determined the magnitude of high-frequency attenuation for a 21.5 m long inlet tube of an operating REA system. In a second step, we simulated the impact for different artificial lag time errors and low-pass filter strengths on the REA concentration differences and, thus, on the REA flux, using high-frequency time series of temperature, O3, CO2, and H2O. The reduction of scalar fluxes was mainly correlated with increasing switching frequencies and ranged for typical lag time errors of the investigated REA system between <5% and 50%, whereas the flux loss due to high-frequency attenuation was between <5% and 30%. The results were very similar for all scalar quantities. Based on our results, we derived empirical correction functions for both imprecise lag times and high-frequency attenuation, discuss their potential application to correct fluxes measured with other REA systems, and give a general procedure to address the uncertainties in future REA setups.

  18. Hyaluronan Accumulates With High-Fat Feeding and Contributes to Insulin Resistance

    PubMed Central

    Kang, Li; Lantier, Louise; Kennedy, Arion; Bonner, Jeffrey S.; Mayes, Wesley H.; Bracy, Deanna P.; Bookbinder, Louis H.; Hasty, Alyssa H.; Thompson, Curtis B.; Wasserman, David H.

    2013-01-01

    Increased deposition of specific extracellular matrix (ECM) components is a characteristic of insulin-resistant skeletal muscle. Hyaluronan (HA) is a major constituent of the ECM. The hypotheses that 1) HA content is increased in the ECM of insulin-resistant skeletal muscle and 2) reduction of HA in the muscle ECM by long-acting pegylated human recombinant PH20 hyaluronidase (PEGPH20) reverses high-fat (HF) diet–induced muscle insulin resistance were tested. We show that muscle HA was increased in HF diet–induced obese (DIO) mice and that treatment of PEGPH20, which dose-dependently reduced HA in muscle ECM, decreased fat mass, adipocyte size, and hepatic and muscle insulin resistance in DIO mice at 10 mg/kg. Reduced muscle insulin resistance was associated with increased insulin signaling, muscle vascularization, and percent cardiac output to muscle rather than insulin sensitization of muscle per se. Dose-response studies revealed that PEGPH20 dose-dependently increased insulin sensitivity in DIO mice with a minimally effective dose of 0.01 mg/kg. PEGPH20 at doses of 0.1 and 1 mg/kg reduced muscle HA to levels seen in chow-fed mice, decreased fat mass, and increased muscle glucose uptake. These findings suggest that ECM HA is a target for treatment of insulin resistance. PMID:23349492

  19. Cerebrospinal fluid concentrations of hypoxanthine, xanthine, uridine and inosine: high concentrations of the ATP metabolite, hypoxanthine, after hypoxia.

    PubMed Central

    Harkness, R A; Lund, R J

    1983-01-01

    CSF obtained for clinical purposes from newborn, children and adults has been analysed by high pressure liquid chromatography for hypoxanthine, xanthine, inosine, uridine and urate. Large rises in hypoxanthine and to a lesser extent xanthine occur for about 24 h after hypoxia. High concentrations were associated with later evidence of brain damage or subsequent death. Changes in CSF could be independent of those in plasma. Small or negligible rises were associated with localised and generalised infections including bacterial meningitis, fits, or both. Marked and rapid rises were found after death. These estimations may "predict" the extent of brain damage or brain death. PMID:6681617

  20. Nitrogen accumulation and partitioning in a High Arctic tundra ecosystem from extreme atmospheric N deposition events.

    PubMed

    Choudhary, Sonal; Blaud, Aimeric; Osborn, A Mark; Press, Malcolm C; Phoenix, Gareth K

    2016-06-01

    Arctic ecosystems are threatened by pollution from recently detected extreme atmospheric nitrogen (N) deposition events in which up to 90% of the annual N deposition can occur in just a few days. We undertook the first assessment of the fate of N from extreme deposition in High Arctic tundra and are presenting the results from the whole ecosystem (15)N labelling experiment. In 2010, we simulated N depositions at rates of 0, 0.04, 0.4 and 1.2 g Nm(-2)yr(-1), applied as (15)NH4(15)NO3 in Svalbard (79(°)N), during the summer. Separate applications of (15)NO3(-) and (15)NH4(+) were also made to determine the importance of N form in their retention. More than 95% of the total (15)N applied was recovered after one growing season (~90% after two), demonstrating a considerable capacity of Arctic tundra to retain N from these deposition events. Important sinks for the deposited N, regardless of its application rate or form, were non-vascular plants>vascular plants>organic soil>litter>mineral soil, suggesting that non-vascular plants could be the primary component of this ecosystem to undergo measurable changes due to N enrichment from extreme deposition events. Substantial retention of N by soil microbial biomass (70% and 39% of (15)N in organic and mineral horizon, respectively) during the initial partitioning demonstrated their capacity to act as effective buffers for N leaching. Between the two N forms, vascular plants (Salix polaris) in particular showed difference in their N recovery, incorporating four times greater (15)NO3(-) than (15)NH4(+), suggesting deposition rich in nitrate will impact them more. Overall, these findings show that despite the deposition rates being extreme in statistical terms, biologically they do not exceed the capacity of tundra to sequester pollutant N during the growing season. Therefore, current and future extreme events may represent a major source of eutrophication. PMID:26956177

  1. Ultra-low specific on-resistance high-voltage vertical double diffusion metal–oxide–semiconductor field-effect transistor with continuous electron accumulation layer

    NASA Astrophysics Data System (ADS)

    Da, Ma; Xiao-Rong, Luo; Jie, Wei; Qiao, Tan; Kun, Zhou; Jun-Feng, Wu

    2016-04-01

    A new ultra-low specific on-resistance (R on,sp) vertical double diffusion metal–oxide–semiconductor field-effect transistor (VDMOS) with continuous electron accumulation (CEA) layer, denoted as CEA-VDMOS, is proposed and its new current transport mechanism is investigated. It features a trench gate directly extended to the drain, which includes two PN junctions. In on-state, the electron accumulation layers are formed along the sides of the extended gate and introduce two continuous low-resistance current paths from the source to the drain in a cell pitch. This mechanism not only dramatically reduces the R on,sp but also makes the R on,sp almost independent of the n-pillar doping concentration (N n). In off-state, the depletion between the n-pillar and p-pillar within the extended trench gate increases the N n, and further reduces the R on,sp. Especially, the two PN junctions within the trench gate support a high gate–drain voltage in the off-state and on-state, respectively. However, the extended gate increases the gate capacitance and thus weakens the dynamic performance to some extent. Therefore, the CEA-VDMOS is more suitable for low and medium frequencies application. Simulation indicates that the CEA-VDMOS reduces the R on,sp by 80% compared with the conventional super-junction VDMOS (CSJ-VDMOS) at the same high breakdown voltage (BV). Project supported by the National Natural Science Foundation of China (Grant Nos. 61176069 and 61376079) and the Fundamental Research Funds for the Central Universities, China (Grant No. ZYGX2014Z006).

  2. Accumulation and conversion of sugars by developing wheat grains. VII. Effect of changes in sieve tube and endosperm cavity sap concentrations on the grain filling rate. [Triticum aestivum

    SciTech Connect

    Fisher, D.B.; Gifford, R.M.

    1987-06-01

    The extent to which wheat grain growth is dependent on transport pool solute concentration was investigated by the use of illumination and partial grain removal to vary solute concentrations in the sieve tube and endosperm cavity saps of the wheat ear (Triticum aestivum L.). Short-term grain growth rates were estimated indirectly from the product of phloem area, sieve tube sap concentration, and /sup 32/P translocation velocity. On a per grain basis, calculated rates of mass transport through the peduncle were fairly constant over a substantial range in other transport parameters (i.e. velocity, concentration, phloem area, and grain number). The rates were about 40% higher than expected; this probably reflects some unavoidable bias on faster-moving tracer in the velocity estimates. Sieve tube sap concentration increased in all experiments (by 20 to 64%), with a concomitant decline in velocity (to as low as 8% of the initial value). Endosperm cavity sucrose concentration also increased in all experiments, but cavity sap osmolality and total amino acid concentration remained nearly constant. No evidence was found for an increase in the rate of mass transport per grain through the peduncle in response to the treatments. This apparent unresponsiveness of grain growth rate to increased cavity sap sucrose concentration conflicts with earlier in vitro endosperm studies showing that sucrose uptake increased with increasing external sucrose concentration up to 150 to 200 millimolar.

  3. Malting revisited: Germination of barley (Hordeum vulgare L.) is inhibited by both oxygen deficiency and high carbon dioxide concentrations.

    PubMed

    Kleinwächter, Maik; Meyer, Ann-Kathrin; Selmar, Dirk

    2012-05-01

    During malting, barley (Hordeum vulgare L.) seeds are germinated to promote the mobilisation of storage compounds. Germination is strongly influenced by O2 and CO2; however, any distinction between the particular effects is missing. Since, in this study, the ambient O2 concentration was maintained when high CO2 concentrations were applied, for the first time the impacts of CO2 and of O2 deficiency could be distinguished unambiguously. Germination was inhibited by both O2 deficiency and high CO2 (80%) concentrations, documented by the lack of any growth of coleoptiles and any increase of α-amylase and β-glucanase activity. In contrast, the related impacts of O2 starvation and high CO2 on fermentation differ strongly, demonstrated by quite different patterns of ethanol emission. Additionally, the stress metabolism - monitored by the means of GABA accumulation - was also differently impacted. The elucidation of the underlying, so far unknown, mechanisms will provide novel opportunities to improve malting. PMID:26434318

  4. Zinc Excess Triggered Polyamines Accumulation in Lettuce Root Metabolome, As Compared to Osmotic Stress under High Salinity

    PubMed Central

    Rouphael, Youssef; Colla, Giuseppe; Bernardo, Letizia; Kane, David; Trevisan, Marco; Lucini, Luigi

    2016-01-01

    Abiotic stresses such as salinity and metal contaminations are the major environmental stresses that adversely affect crop productivity worldwide. Crop responses and tolerance to abiotic stress are complex processes for which “-omic” approaches such as metabolomics is giving us a newest view of biological systems. The aim of the current research was to assess metabolic changes in lettuce (Lactuca sativa L.), by specifically probing the root metabolome of plants exposed to elevated isomolar concentrations of NaCl and ZnSO4. Most of the metabolites that were differentially accumulated in roots were identified for stress conditions, however the response was more intense in plants exposed to NaCl. Compounds identified in either NaCl or ZnSO4 conditions were: carbohydrates, phenolics, hormones, glucosinolates, and lipids. Our findings suggest that osmotic stress and the consequent redox imbalance play a major role in determining lettuce root metabolic response. In addition, it was identified that polyamines and polyamine conjugates were triggered as a specific response to ZnSO4. These findings help improve understanding of how plants cope with abiotic stresses. This information can be used to assist decision-making in breeding programs for improving crop tolerance to salinity and heavy metal contaminations. PMID:27375675

  5. Zinc Excess Triggered Polyamines Accumulation in Lettuce Root Metabolome, As Compared to Osmotic Stress under High Salinity.

    PubMed

    Rouphael, Youssef; Colla, Giuseppe; Bernardo, Letizia; Kane, David; Trevisan, Marco; Lucini, Luigi

    2016-01-01

    Abiotic stresses such as salinity and metal contaminations are the major environmental stresses that adversely affect crop productivity worldwide. Crop responses and tolerance to abiotic stress are complex processes for which "-omic" approaches such as metabolomics is giving us a newest view of biological systems. The aim of the current research was to assess metabolic changes in lettuce (Lactuca sativa L.), by specifically probing the root metabolome of plants exposed to elevated isomolar concentrations of NaCl and ZnSO4. Most of the metabolites that were differentially accumulated in roots were identified for stress conditions, however the response was more intense in plants exposed to NaCl. Compounds identified in either NaCl or ZnSO4 conditions were: carbohydrates, phenolics, hormones, glucosinolates, and lipids. Our findings suggest that osmotic stress and the consequent redox imbalance play a major role in determining lettuce root metabolic response. In addition, it was identified that polyamines and polyamine conjugates were triggered as a specific response to ZnSO4. These findings help improve understanding of how plants cope with abiotic stresses. This information can be used to assist decision-making in breeding programs for improving crop tolerance to salinity and heavy metal contaminations. PMID:27375675

  6. Selection of microalgae for high CO2 fixation efficiency and lipid accumulation from ten Chlorella strains using municipal wastewater.

    PubMed

    Hu, Xia; Zhou, Jiti; Liu, Guangfei; Gui, Bing

    2016-08-01

    As significant differences in cellular physiology, metabolic potential and genetics occur among strains with morphological similarity, the screening of appropriate microalgae species for effective CO2 fixation and biodiesel production is extremely critical. In this study, ten strains of Chlorella were cultivated in municipal wastewater influent (MWI) and their tolerance for MWI, CO2 fixation efficiency and lipid productivity were assessed. The results showed that the biomass concentrations of four strains (Chlorella vulgaris, Chlorella 64.01, Chlorella regularis var. minima and Chlorella sp.) were significantly higher than other strains. When the cultivation systems were aerated with 10% CO2, Chlorella sp. showed the highest CO2 fixation efficiency (35.51%), while the highest lipid accumulation (58.48%) was observed with C. vulgaris. Scanning electron microscopy images revealed that the cells of both Chlorella sp. and C. vulgaris kept their normal morphologies after 15day batch culture. These findings indicated that Chlorella sp. and C. vulgaris have fairly good tolerance for MWI, and moreover, Chlorella sp. was appropriate for CO2 fixation while C. vulgaris represented the highest potential for producing biodiesel. PMID:27521939

  7. High Resolution Quantification of Crystalline Cellulose Accumulation in Arabidopsis Roots to Monitor Tissue-specific Cell Wall Modifications.

    PubMed

    Fridman, Yulia; Holland, Neta; Elbaum, Rivka; Savaldi-Goldstein, Sigal

    2016-01-01

    Plant cells are surrounded by a cell wall, the composition of which determines their final size and shape. The cell wall is composed of a complex matrix containing polysaccharides that include cellulose microfibrils that form both crystalline structures and cellulose chains of amorphous organization. The orientation of the cellulose fibers and their concentrations dictate the mechanical properties of the cell. Several methods are used to determine the levels of crystalline cellulose, each bringing both advantages and limitations. Some can distinguish the proportion of crystalline regions within the total cellulose. However, they are limited to whole-organ analyses that are deficient in spatiotemporal information. Others relying on live imaging, are limited by the use of imprecise dyes. Here, we report a sensitive polarized light-based system for specific quantification of relative light retardance, representing crystalline cellulose accumulation in cross sections of Arabidopsis thaliana roots. In this method, the cellular resolution and anatomical data are maintained, enabling direct comparisons between the different tissues composing the growing root. This approach opens a new analytical dimension, shedding light on the link between cell wall composition, cellular behavior and whole-organ growth. PMID:27214583

  8. Increased accumulation of carbohydrates and decreased photosynthetic gene transcript levels in wheat grown at an elevated CO{sub 2} concentration in the field

    SciTech Connect

    Nie, G.; Hendrix, D.L.; Webber, A.N.

    1995-07-01

    Repression of photosynthetic genes by increased soluble carbohydrate concentrations may explain acclimation of photosynthesis to elevated CO{sub 2} concentration. This hypothesis was examined in a field crop of spring wheat (Triticum aestivum L.) grown at both ambient (approximately 360 {mu}mol{sup -1}) and elevated (550 {mu}mol mol{sup -1}) atmospheric CO{sub 2} concentrations using free-air CO{sub 2} enrichment at Maricopa, Arizona. The correspondence of steady-state levels of mRNA transcripts (coding for the 83-kD photosystem 1 apoprotein, sedoheptulose-1,7-bisphosphatase, phosphoribulokinase, phosphoglcerodkinase, and the large and small subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase) with leaf carbohydrate concentrations (glucose-6-phosphate, glucose, fructose, sucrose, fructans, and starch) was examined at different stages of crop and leaf development and through the diurnal cycle. Overall only a weak correspondence between increased soluble carbohydrate concentrations and decreased levels for nuclear gene transcripts was found. The difference in soluble carbohydrate concentration between leaves grown at elevated and current ambient CO{sub 2} concentrations diminished with crop development, whereas the difference in transcript levels increased. In the flag leaf, soluble carbohydrate concentrations declined markedly with the onset of grain filling; yet transcript levels also declined. The results suggest that, many other factors modified its significance in this field wheat crop. 52 refs., 8 figs.

  9. Passive treatment of acid mine drainage with high metal concentrations using dispersed alkaline substrate.

    PubMed

    Rötting, Tobias S; Thomas, Robert C; Ayora, Carlos; Carrera, Jesús

    2008-01-01

    Passive treatment systems based on the dissolution of coarse calcite grains are widely used to remediate acid mine drainage (AMD). Unfortunately, they tolerate only low metal concentrations or acidity loads, because they are prone to passivation (loss of reactivity due to coating) and/or clogging (loss of permeability) by precipitates. To overcome these problems, a dispersed alkaline substrate (DAS) composed of a fine-grained alkaline reagent (calcite sand) mixed with a coarse inert matrix (wood chips) was developed. The small grains provide a large reactive surface and dissolve almost completely before the growing layer of precipitates passivates the substrate, whereas the dispersion of nuclei for precipitation on the inert surfaces retards clogging. Chemical and hydraulic performance of DAS was investigated in two laboratory columns fed at different flow rates with natural AMD of pH 2.3 to 3.5 and inflow net acidity 1350 to 2300 mg/L as CaCO(3). The DAS columns removed 900 to 1600 mg/L net acidity, 3 to 4.5 times more than conventional passive treatment systems. Regardless of the flow rate employed, Al, Fe(III), Cu, and Pb were virtually eliminated. Minor Zn, Ni, and Cd were removed at low flow rates. High acidity removal is possible because these metals accumulate intentionally in DAS, and their precipitation promotes further calcite dissolution. During 15 mo, DAS operated without clogging at 120 g acidity/m(2).d, four times the loading rate recommended for conventional passive systems; DAS may therefore be capable of treating AMD at sites where influent chemistry precludes the use of other passive systems. PMID:18689735

  10. Cellular cholesterol accumulation modulates high fat high sucrose (HFHS) diet-induced ER stress and hepatic inflammasome activation in the development of non-alcoholic steatohepatitis.

    PubMed

    Bashiri, Amir; Nesan, Dinushan; Tavallaee, Ghazaleh; Sue-Chue-Lam, Ian; Chien, Kevin; Maguire, Graham F; Naples, Mark; Zhang, Jing; Magomedova, Lilia; Adeli, Khosrow; Cummins, Carolyn L; Ng, Dominic S

    2016-07-01

    Non-alcoholic steatohepatitis (NASH), is the form of non-alcoholic fatty liver disease posing risk to progress into serious long term complications. Human and pre-clinical models implicate cellular cholesterol dysregulation playing important role in its development. Mouse model studies suggest synergism between dietary cholesterol and fat in contributing to NASH but the mechanisms remain poorly understood. Our laboratory previously reported the primary importance of hepatic endoplasmic reticulum cholesterol (ER-Chol) in regulating hepatic ER stress by comparing the responses of wild type, Ldlr-/-xLcat+/+ and Ldlr-/-xLcat-/- mice, to a 2% high cholesterol diet (HCD). Here we further investigated the roles of ER-Chol and ER stress in HFHS diet-induced NASH using the same strains. With HFHS diet feeding, both WT and Ldlr-/-xLcat+/+ accumulate ER-Chol in association with ER stress and inflammasome activation but the Ldlr-/-xLcat-/- mice are protected. By contrast, all three strains accumulate cholesterol crystal, in correlation with ER-Chol, albeit less so in Ldlr-/-xLcat-/- mice. By comparison, HCD feeding per se (i) is sufficient to promote steatosis and activate inflammasomes, and (ii) results in dramatic accumulation of cholesterol crystal which is linked to inflammasome activation in Ldlr-/-xLcat-/- mice, independent of ER-Chol. Our data suggest that both dietary fat and cholesterol each independently promote steatosis, cholesterol crystal accumulation and inflammasome activation through distinct but complementary pathways. In vitro studies using palmitate-induced hepatic steatosis in HepG2 cells confirm the key roles by cellular cholesterol in the induction of steatosis and inflammasome activations. These novel findings provide opportunities for exploring a cellular cholesterol-focused strategy for treatment of NASH. PMID:27090939

  11. Accumulation of artificial radionuclides in agricultural plants in the area used for surface nuclear tests.

    PubMed

    Kozhakhanov, T E; Lukashenko, S N; Larionova, N V

    2014-11-01

    The paper reports on the study of artificial radionuclide accumulation in agricultural crops grown at the territory with high concentration of radionuclides, and first of all - with high concentration of transuranium elements. As a result of this work, peculiarities of accumulation and distribution of artificial radionuclides in the vegetative and generative organs of the studied plants have been revealed. Basic accumulation factors have been found for (137)Cs, (90)Sr, (239+240)Pu, and (241)Am in agricultural products. Accumulation factor dependence on type of planting was found for the investigated types of plants. It has been found that the vegetative organs accumulate radionuclides most of all. PMID:25128979

  12. Age-related changes in amino acid pool sizes in the adult silkmoth, Bombyx mori, reared at low and high temperature; a biochemical examination of the rate-of-living theory and urea accumulation when reared at high temperature.

    PubMed

    Osanai, M; Yonezawa, Y

    1984-01-01

    To examine the rate-of-living theory, age-related changes in amino acid pool sizes were investigated in the adult silkmoth, Bombyx mori, reared at low and high temperature. At either temperature concentrations of free amino acids contained in silkmoths revealed a great sexual difference. Those in females were generally much higher than in males and the former changed much more dynamically than the latter. Major amino acids or ninhydrin-positive compounds inclusive of some essential amino acids such as Leu, Ile, Val, Thr, Arg, Phe, Met, Ala, Tyr, Gln, Aspn , Lan , Cysta , GABA and PEA accumulated in 4 degrees C-moths. However, the levels of these amino changed irregularly with advanced age. Inhibition of protein synthesis may occur generally at low temperature, while protein degradation may be promoted at high temperature. High concentrations of MSO and Tau in the moths reared at high temperature than in the normal moths suggested also catabolism of amino acids proceeding together with protein degradation at high temperature. Amino acid metabolism seems to be complicated under various temperature conditions. When reared at the optimal temperature of 25 degrees C, urea is not present in the body of the silkmoth except for a slight amount in the secreted meconium. In silkmoths reared at the higher temperature of 35 degrees C, however, an extraordinary accumulation of urea occurs accompanied by a reduction in lifespan by one half. Undoubtedly, urea is produced in this terrestrial insect, although the accumulation mechanism is not clear: in silkmoths reared at various temperatures, arginase is found, but urease is not detected. Arginase activity was found to be higher in male moths than in female moths regardless of the rearing temperature. High temperature rearing also did not induce activity and female activity never exceeded that in males at either 25 degrees C or 35 degrees C rearing. Protein degradation accelerated by rearing at high temperatures may result in

  13. High-Efficiency Solar Thermal Vacuum Demonstration Completed for Refractive Secondary Concentrator

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.

    2001-01-01

    Common to many of the space applications that utilize solar thermal energy--such as electric power conversion, thermal propulsion, and furnaces--is a need for highly efficient, solar concentration systems. An effort is underway at the NASA Glenn Research Center to develop the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced lightweight primary concentrators, the refractive secondary concentrator enables very high system concentration ratios (10,000 to 1) and very high temperatures (>2000 K). The innovative refractive secondary concentrator offers significant advantages over all other types of secondary concentrators. The refractive secondary offers the highest throughput efficiency, provides for flux tailoring, requires no active cooling, relaxes the pointing and tracking requirements of the primary concentrator, and enables very high system concentration ratios. This technology has broad applicability to any system that requires the conversion of solar energy to heat. Glenn initiated the development of the refractive secondary concentrator in support of Shooting Star, a solar thermal propulsion flight experiment, and continued the development in support of Space Solar Power.

  14. Application of high-content image analysis for quantitatively estimating lipid accumulation in oleaginous yeasts with potential for use in biodiesel production.

    PubMed

    Capus, Aurélie; Monnerat, Marianne; Ribeiro, Luiz Carlos; de Souza, Wanderley; Martins, Juliana Lopes; Sant'Anna, Celso

    2016-03-01

    Biodiesel from oleaginous microorganisms is a viable substitute for a fossil fuel. Current methods for microorganism lipid productivity evaluation do not analyze lipid dynamics in single cells. Here, we described a high-content image analysis (HCA) as a promising strategy for screening oleaginous microorganisms for biodiesel production, while generating single-cell lipid dynamics data in large cell density. Rhodotorula slooffiae yeast were grown in standard (CTL) or lipid trigger medium (LTM), and lipid droplet (LD) accumulation was analyzed in deconvolved confocal microscopy images of cells stained with the lipophilic fluorescent Nile red (NR) dye using automated cell and LD segmentation. The 'vesicle segmentation' method yielded valid morphometric results for limited lipid accumulation in smaller LDs (CTL samples) and for high lipid accumulation in larger LDs (LTM samples), and detected LD localization changes. Thus, HCA can be used to analyze the lipid accumulation patterns likely to be encountered in screens for biodiesel production. PMID:26744805

  15. Accumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin by rainbow trout (Onchorhynchus mykiss) at environmentally relevant dietary concentrations

    USGS Publications Warehouse

    Jones, P.D.; Kannan, K.; Newsted, J.L.; Tillitt, D.E.; Williams, L.L.; Giesy, J.P.

    2001-01-01

    Rainbow trout were fed a diet containing 1.8, 18, or 90 pg/g 3H-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for up to 320 d. Concentrations of TCDD were determined in muscle, liver, and ovaries at 100, 150, 200, and 250 d. Concentrations of TCDD reached an apparent steady-state concentration in liver after 100 d of exposure, whereas concentrations in other tissues continued to increase until 150 d of exposure. The greatest portion of the total mass of TCDD was present in the muscle tissue with lesser proportions in other organs. As the ovaries developed before spawning, an increase occurred in the total mass of TCDD present in this tissue. The assimilation rate of TCDD during the initial 100 d of the exposure was determined to be between 10 and 30%. This is somewhat less than estimates derived based on both uptake and elimination constants determined during shorter exposures. Biomagnification factors (BMFs) were estimated for all tissues and exposure concentrations, and at all exposure periods. Lipid-normalized BMFs for muscle ranged from 0.38 to 1.51, which is consistent with the value of 1.0 predicted from fugacity theory. Uptake and depuration rate constants were determined and used to predict individual organ TCDD concentrations. Comparison with observed values indicated that the model could be used to predict tissue concentrations from the known concentrations of TCDD in food. This model will allow more refined risk assessments by predicting TCDD concentrations in sensitive tissues such as developing eggs.

  16. TFH cells accumulate in mucosal tissues of humanized-DRAG mice and are highly permissive to HIV-1

    PubMed Central

    Allam, Atef; Majji, Sai; Peachman, Kristina; Jagodzinski, Linda; Kim, Jiae; Ratto-Kim, Silvia; Wijayalath, Wathsala; Merbah, Melanie; Kim, Jerome H.; Michael, Nelson L.; Alving, Carl R.; Casares, Sofia; Rao, Mangala

    2015-01-01

    CD4+ T follicular helper cells (TFH) in germinal centers are required for maturation of B-cells. While the role of TFH-cells has been studied in blood and lymph nodes of HIV-1 infected individuals, its role in the mucosal tissues has not been investigated. We show that the gut and female reproductive tract (FRT) of humanized DRAG mice have a high level of human lymphocytes and a high frequency of TFH (CXCR5+PD-1++) and precursor-TFH (CXCR5+PD-1+) cells. The majority of TFH-cells expressed CCR5 and CXCR3 and are the most permissive to HIV-1 infection. A single low-dose intravaginal HIV-1 challenge of humanized DRAG mice results in 100% infectivity with accumulation of TFH-cells mainly in the Peyer’s patches and FRT. The novel finding of TFH-cells in the FRT may contribute to the high susceptibility of DRAG mice to HIV-1 infection. This mouse model thus provides new opportunities to study TFH-cells and to evaluate HIV-1 vaccines. PMID:26034905

  17. A glutathione reductase mutant of yeast accumulates high levels of oxidized glutathione and requires thioredoxin for growth.

    PubMed Central

    Muller, E G

    1996-01-01

    A glutathione reductase null mutant of Saccharomyces cerevisiae was isolated in a synthetic lethal genetic screen for mutations which confer a requirement for thioredoxin. Yeast mutants that lack glutathione reductase (glr1 delta) accumulate high levels of oxidized glutathione and have a twofold increase in total glutathione. The disulfide form of glutathione increases 200-fold and represents 63% of the total glutathione in a glr1 delta mutant compared with only 6% in wild type. High levels of oxidized glutathione are also observed in a trx1 delta, trx2 delta double mutant (22% of total), in a glr1 delta, trx1 delta double mutant (71% of total), and in a glr1 delta, trx2 delta double mutant (69% of total). Despite the exceptionally high ratio of oxidized/reduced glutathione, the glr1 delta mutant grows with a normal cell cycle. However, either one of the two thioredoxins is essential for growth. Cells lacking both thioredoxins and glutathione reductase are not viable under aerobic conditions and grow poorly anaerobically. In addition, the glr1 delta mutant shows increased sensitivity to the thiol oxidant diamide. The sensitivity to diamide was suppressed by deletion of the TRX2 gene. The genetic analysis of thioredoxin and glutathione reductase in yeast runs counter to previous studies in Escherichia coli and for the first time links thioredoxin with the redox state of glutathione in vivo. Images PMID:8930901

  18. TFH cells accumulate in mucosal tissues of humanized-DRAG mice and are highly permissive to HIV-1.

    PubMed

    Allam, Atef; Majji, Sai; Peachman, Kristina; Jagodzinski, Linda; Kim, Jiae; Ratto-Kim, Silvia; Wijayalath, Wathsala; Merbah, Melanie; Kim, Jerome H; Michael, Nelson L; Alving, Carl R; Casares, Sofia; Rao, Mangala

    2015-01-01

    CD4(+) T follicular helper cells (TFH) in germinal centers are required for maturation of B-cells. While the role of TFH-cells has been studied in blood and lymph nodes of HIV-1 infected individuals, its role in the mucosal tissues has not been investigated. We show that the gut and female reproductive tract (FRT) of humanized DRAG mice have a high level of human lymphocytes and a high frequency of TFH (CXCR5(+)PD-1(++)) and precursor-TFH (CXCR5(+)PD-1(+)) cells. The majority of TFH-cells expressed CCR5 and CXCR3 and are the most permissive to HIV-1 infection. A single low-dose intravaginal HIV-1 challenge of humanized DRAG mice results in 100% infectivity with accumulation of TFH-cells mainly in the Peyer's patches and FRT. The novel finding of TFH-cells in the FRT may contribute to the high susceptibility of DRAG mice to HIV-1 infection. This mouse model thus provides new opportunities to study TFH-cells and to evaluate HIV-1 vaccines. PMID:26034905

  19. A deficiency of manganese ions in the presence of high sugar concentrations is the critical parameter for achieving high yields of itaconic acid by Aspergillus terreus.

    PubMed

    Karaffa, Levente; Díaz, Rafael; Papp, Benedek; Fekete, Erzsébet; Sándor, Erzsébet; Kubicek, Christian P

    2015-10-01

    Itaconic acid (IA), an unsaturated dicarboxylic acid with a high potential as a platform for chemicals derived from sugars, is industrially produced by large-scale submerged fermentation by Aspergillus terreus. Although the biochemical pathway and the physiology leading to IA is almost the same as that leading to citric acid production in Aspergillus niger, published data for the volumetric (g L(-1)) and the specific yield (mol/mol carbon source) of IA are significantly lower than for citric acid. Citric acid is known to accumulate to high levels only when a number of nutritional parameters are carefully adjusted, of which the concentration of the carbon source and that of manganese ions in the medium are particularly important. We have therefore investigated whether a variation in these two parameters may enhance IA production and yield by A. terreus. We show that manganese ion concentrations < 3 ppb are necessary to obtain highest yields. Highest yields were also dependent on the concentration of the carbon source (D-glucose), and highest yields (0.9) were only obtained at concentrations of 12-20 % (w/v), thus allowing the accumulation of up to 130 g L(-1) IA. These findings perfectly mirror those obtained when these parameters are varied in citric acid production by A. niger, thus showing that the physiology of both processes is widely identical. Consequently, applying the fermentation technology established for citric acid production by A. niger citric acid production to A. terreus should lead to high yields of IA, too. PMID:26078111

  20. MICROSTRUCTURAL PROPERTIES OF HIGH-LEVEL WASTE CONCENTRATES AND GELS WITH RAMAN AND INFRARED SPECTROSCOPIES

    EPA Science Inventory

    Nearly half of the high level radioactive waste stored at Hanford is composed of highly alkaline concentrates referred to as either salt cakes or Double-Shell Slurry (DSS), depending on their compositions and processing histories. The major components of these concentrates are wa...

  1. Effect of soil weathering degree on the increase of cotton biomass and silicon mineralomass after amendment with biochar highly concentrated in phytoliths

    NASA Astrophysics Data System (ADS)

    Li, Zimin; Delvaux, Bruno; Yans, Johan; Dufour, Nicolas; Houben, David; Cornelis, Jean-Thomas

    2016-04-01

    Silicon (Si) is beneficial for plants, but not essential. It plays a crucial role in improving the yields of Si-accumulator crops through alleviating various biotic and abiotic stresses. The demand of Si fertilizers will likely increase due to soil desilication and removal of harvested biomass. Since plants accumulate Si in the form of readily soluble phytoliths, plant-derived biochar is considered as a Si source for Si accumulator crops. In addition to its beneficial effects on soil fertility and carbon sequestration, biochar is a promising cost-effective and environmentally friendly alternative to conventional Si amendments. Here, we study the impact of biochar materials with different phytolith concentrations on the bioavailability of Si in soils differing in weathering stage, and its effect on cotton biomass and Si mineralomass. Two biochar materials were used: Miscanthus x giganteus (Si concentration: 34.6 g/kg) and soft woody material (Si concentration: 0.9 g/kg). A conventional wollastonite (CaSiO3) treatment was carried for comparison purpose. The concentration of bioavailable Si was determined through 0.01 M CaCl2 extraction. Biochars were incorporated at the rate of 3% (w/w) in two soils: a slightly weathered Cambisol and a highly weathered Nitisol. The Miscanthus biochar ability to release bioavailable Si in the Cambisol (CaCl2 extractable Si/total Si concentration) is significantly smaller (0.9%) than the one of wollastonite (5.2%). In the highly weathered Nitisol, the Miscanthus biochar ability to release bioavailable Si is much larger (1.4%) than that of wollastonite (0.7%). Miscanthus biochar significantly increases the cotton biomass and Si mineralomass relative to soft wood biochar. The increase is larger in the highly weathered Nitisol than in the slightly weathered Cambisol. Principal component analyses and linear regression show that both the larger release rate of bioavailable Si and CEC are the main factors responsible for the increase of

  2. High osmolarity glycerol (HOG) pathway-induced phosphorylation and activation of 6-phosphofructo-2-kinase are essential for glycerol accumulation and yeast cell proliferation under hyperosmotic stress.

    PubMed

    Dihazi, Hassan; Kessler, Renate; Eschrich, Klaus

    2004-06-01

    In response to changes in the environment, yeast cells coordinate intracellular activities to optimize survival and proliferation. The transductions of diverse extracellular stimuli are exerted through multiple mitogen-activated protein kinase (MAPK) cascades. The high osmolarity glycerol (HOG) MAPK pathway is activated by increased environmental osmolarity and results in a rise of the cellular glycerol concentration to adapt the intracellular osmotic pressure. We studied the importance of the short time regulation of glycolysis under hyperosmotic stress for the survival and proliferation of yeast cells. A stimulation of the HOG-MAPK pathway by increasing the medium osmolarity through addition of salt or glucose to cultivated yeast leads to an activation of 6-phosphofructo-2-kinase (PFK2), which is accompanied by a complex phosphorylation pattern of the enzyme. An increase in medium osmolarity with 5% NaCl activates PFK2 3-fold over the initial value. This change in the activity is the result of a 4-fold phosphorylation of the enzyme mediated by protein kinases from the HOG-MAPK pathway. In the case of hyperosmolar glucose a 5-fold PFK2 activation was achieved by a single phosphorylation with protein kinase A near the carboxyl terminus of the protein on Ser(644) and an additional 5-fold phosphorylation within the same amino-terminal fragment as in the presence of salt. The effect of hyperosmolar glucose is the result of an activation of the Ras-cAMP pathway together with the HOG-MAPK pathway. The activation of PFK2 leads to an activation of the upper part of glycolysis, which is a precondition for glycerol accumulation. Yeast cells containing PFK2 accumulate three times more glycerol than cells lacking PFK2, which are not able to grow under hypertonic stress. PMID:15037628

  3. Transient proliferation of proanthocyanidin-accumulating cells on the epidermal apex contributes to highly aluminum-resistant root elongation in camphor tree.

    PubMed

    Osawa, Hiroki; Endo, Izuki; Hara, Yukari; Matsushima, Yuki; Tange, Takeshi

    2011-01-01

    Aluminum (Al) is a harmful element that rapidly inhibits the elongation of plant roots in acidic soils. The release of organic anions explains Al resistance in annual crops, but the mechanisms that are responsible for superior Al resistance in some woody plants remain unclear. We examined cell properties at the surface layer of the root apex in the camphor tree (Cinnamomum camphora) to understand its high Al resistance mechanism. Exposure to 500 μm Al for 8 d, more than 20-fold higher concentration and longer duration than what soybean (Glycine max) can tolerate, only reduced root elongation in the camphor tree to 64% of the control despite the slight induction of citrate release. In addition, Al content in the root apices was maintained at low levels. Histochemical profiling revealed that proanthocyanidin (PA)-accumulating cells were present at the adjacent outer layer of epidermis cells at the root apex, having distinctive zones for cell division and the early phase of cell expansion. Then the PA cells were gradually detached off the root, leaving thin debris behind, and the root surface was replaced with the elongating epidermis cells at the 3- to 4-mm region behind the tip. Al did not affect the proliferation of PA cells or epidermis cells, except for the delay in the start of expansion and the accelerated detachment of the former. In soybean roots, the innermost lateral root cap cells were absent in both PA accumulation and active cell division and failed to protect the epidermal cell expansion at 25 μm Al. These results suggest that transient proliferation and detachment of PA cells may facilitate the expansion of epidermis cells away from Al during root elongation in camphor tree. PMID:21045123

  4. High-sensitivity in situ QCLAS-based ammonia concentration sensor for high-temperature applications

    NASA Astrophysics Data System (ADS)

    Peng, W. Y.; Sur, R.; Strand, C. L.; Spearrin, R. M.; Jeffries, J. B.; Hanson, R. K.

    2016-07-01

    A novel quantum cascade laser (QCL) absorption sensor is presented for high-sensitivity in situ measurements of ammonia (hbox {NH}_3) in high-temperature environments, using scanned wavelength modulation spectroscopy (WMS) with first-harmonic-normalized second-harmonic detection (scanned WMS-2 f/1 f) to neutralize the effect of non-absorption losses in the harsh environment. The sensor utilized the sQ(9,9) transition of the fundamental symmetric stretch band of hbox {NH}_3 at 10.39 {\\upmu }hbox {m} and was sinusoidally modulated at 10 kHz and scanned across the peak of the absorption feature at 50 Hz, leading to a detection bandwidth of 100 Hz. A novel technique was used to select an optimal WMS modulation depth parameter that reduced the sensor's sensitivity to spectral interference from hbox {H}_2hbox {O} and hbox {CO}_2 without significantly sacrificing signal-to-noise ratio. The sensor performance was validated by measuring known concentrations of hbox {NH}_3 in a flowing gas cell. The sensor was then demonstrated in a laboratory-scale methane-air burner seeded with hbox {NH}_3, achieving a demonstrated detection limit of 2.8 ± 0.26 ppm hbox {NH}_3 by mole at a path length of 179 cm, equivalence ratio of 0.6, pressure of 1 atm, and temperatures of up to 600 K.

  5. Arsenic accumulation by edible aquatic macrophytes.

    PubMed

    Falinski, K A; Yost, R S; Sampaga, E; Peard, J

    2014-01-01

    Edible aquatic macrophytes grown in arsenic (As)-contaminated soil and sediment were investigated to determine the extent of As accumulation and potential risk to humans when consumed. Nasturtium officinale (watercress) and Diplazium esculentum (warabi) are two aquatic macrophytes grown and consumed in Hawaii. Neither has been assessed for potential to accumulate As when grown in As-contaminated soil. Some former sugarcane plantation soils in eastern Hawaii have been shown to have concentrations of total As over 500 mg kg(-1). It was hypothesized that both species will accumulate more As in contaminated soils than in non-contaminated soils. N. officinale and D. esculentum were collected in areas with and without As-contaminated soil and sediment. High soil As concentrations averaged 356 mg kg(-1), while low soil As concentrations were 0.75 mg kg(-1). Average N. officinale and D. esculentum total As concentrations were 0.572 mg kg(-1) and 0.075 mg kg(-1), respectively, corresponding to hazard indices of 0.12 and 0.03 for adults. Unlike previous studies where watercress was grown in As-contaminated water, N. officinale did not show properties of a hyperaccumulator, yet plant concentrations in high As areas were more than double those in low As areas. There was a slight correlation between high total As in sediment and soil and total As concentrations in watercress leaves and stems, resulting in a plant uptake factor of 0.010, an order of magnitude higher than previous studies. D. esculentum did not show signs of accumulating As in the edible fiddleheads. Hawaii is unique in having volcanic ash soils with extremely high sorption characteristics of As and P that limit release into groundwater. This study presents a case where soils and sediments were significantly enriched in total As concentration, but the water As concentration was below detection limits. PMID:24210365

  6. Determination of water quality variables, endotoxin concentration, and Enterobacteriaceae concentration and identification in southern High Plains dairy lagoons.

    PubMed

    Purdy, C W; Clark, R N; Straus, D C

    2010-04-01

    The objectives of this study were to determine the concentration of endotoxin, determine 20 water quality variables, and identify and enumerate fungal and bacterial pathogens from United States southern High Plains dairy lagoons and control lakes during summer and winter. Water samples were collected in triplicate from the north, south, east, and west quadrants of each body of water. The mean (+/- SEM) winter dairy lagoon endotoxin concentration was significantly higher (9,678+/-1,834 ng/mL) than the summer concentration (3,220+/-810 ng/mL). The mean endotoxin concentration of the 2 control lakes (summer: 58.1+/-8.8 ng/mL; winter: 38.6+/-4.2 ng/mL) was significantly less than that of the dairy lagoons. Two hundred-one Salmonella enterica spp. isolates were identified, 7 serovars were recovered from the dairy lagoons, and 259 Salmonella ssp. were identified from 5 other dairy locations (milk barn, ditch effluent, settling basin, feed alley pad flush, and center pivots). Twenty-eight Salmonella spp. were identified from center pivot water. Escherichia coli O157:H7 pathogens were isolated from other dairy locations but not from lagoons. Neither Salmonella spp. nor E. coli O157:H7 were identified from control lakes. Enterobacteriaceae opportunistic pathogens were isolated from both dairies and control lakes. Important mesophilic and thermophilic catabolic (to manure biosolids) fungal isolates were identified from dairy effluent locations, but no thermophilic fungal isolates were cultured from the control lakes. Adequate curing of green forage following center pivot irrigation is important to kill lagoon water enteric pathogens, even though the lagoon water is mixed with fresh water. Recirculating lagoon water to flush the feed alley pad, where cows stand while eating, to remove manure and using lagoon water to abate dairy dust in loafing pens and unimproved dairy roads is inconsistent with good environmental practice management. PMID:20338428

  7. Case study of the 9 April 2009 ‘brown’ cloud: Observations of usually high cloud droplet concentrations in Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Delene, D. J.

    2009-12-01

    Cloud droplets nucleate on aerosol particles termed cloud condensation nuclei (CCN). It is well known that a larger number concentration of CCN results in a larger number concentration of droplets in developing cumulus clouds. However, the conditions where dust particles can serve as cloud condensation nuclei (CCN) and hence change cloud droplet concentration and precipitation formation processes is uncertain. Aircraft measurements of cloud droplet concentration between 13:20 and 13:30 UTC during the 9 April 2009 flight near Riyadh, Saudi Arabia, show total cloud droplet concentration (3-50 µm in diameter) of 800 to 1200 #/cm-3 at a altitude of 18000 ft. Typical cloud droplet concentration for this type of cloud in the Riyadh region is approximately 400 #/cm-3 and is typical of observation made between 13:00 and 13:20 UTC during the 9 April 2009 flight at 18,000 ft. Photographs of ice accumulation on the unprotected leading edge of the aircraft’s wing due to the freezing of super cooled droplets show a color changed from white during the time of low droplet number condensation to brown during the high droplet number concentration. It is hypothesized that high droplet number concentration observations were the result of ingestion of a large about of dust particles by the cloud. : Case Study of the 9 April 2009 ‘Brown’ Cloud: Observations of Usually High Cloud Droplet Concentrations in Saudi Arabia.

  8. Accumulation of High-Value Lipids in Single-Cell Microorganisms: A Mechanistic Approach and Future Perspectives

    PubMed Central

    2015-01-01

    In recent years attention has been focused on the utilization of microorganisms as alternatives for industrial and nutritional applications. Considerable research has been devoted to techniques for growth, extraction, and purification of high-value lipids for their use as biofuels and biosurfactants as well as high-value metabolites for nutrition and health. These successes argue that the elucidation of the mechanisms underlying the microbial biosynthesis of such molecules, which are far from being completely understood, now will yield spectacular opportunities for industrial scale biomolecular production. There are important additional questions to be solved to optimize the processing strategies to take advantage of the assets of microbial lipids. The present review describes the current state of knowledge regarding lipid biosynthesis, accumulation, and transport mechanisms present in single-cell organisms, specifically yeasts, microalgae, bacteria, and archaea. Similarities and differences in biochemical pathways and strategies of different microorganisms provide a diverse toolset to the expansion of biotechnologies for lipid production. This paper is intended to inspire a generation of lipid scientists to insights that will drive the biotechnologies of microbial production as uniquely enabling players of lipid biotherapeutics, biofuels, biomaterials, and other opportunity areas into the 21st century. PMID:24628496

  9. Pseudomonas aeruginosa Cytotoxicity Is Attenuated at High Cell Density and Associated with the Accumulation of Phenylacetic Acid

    PubMed Central

    Wang, Jianhe; Dong, Yihu; Zhou, Tielin; Liu, Xiaoling; Deng, Yinyue; Wang, Chao; Lee, Jasmine; Zhang, Lian-Hui

    2013-01-01

    Background P. aeruginosa is known to cause acute cytotoxicity against various human and animal cells and tissues. Methodology/Findings Intriguingly, however, in this study we noticed that while a low cell density inoculum of P. aeruginosa caused severe cytotoxicity against human lung tissue cell line A549, increasing the cell density of bacterial inoculum led to decreased cytotoxicity. Addition of the supernatants from high density bacterial culture to low cell density inoculum protected the human cells from bacterial cytotoxic damage, suggesting that P. aeruginosa may produce and accumulate an inhibitory molecule(s) counteracting its pathogenic infection. The inhibitor was purified from the stationary-phase culture supernatants of P. aeruginosa strain PAO1 using bioassay-guided high performance liquid chromatography (HPLC), and characterized to be phenylacetic acid (PAA) by mass spectrometry and nuclear magnetic resonance spectroscopy. Microarray analysis revealed that treatment of P. aeruginosa with PAA down-regulated the transcriptional expression of Type III secretion system (T3SS) genes and related regulatory genes including rsmA and vfr, which were confirmed by transcriptional and translational analysis. Conclusions Identification of bacterial metabolite PAA as a T3SS-specific inhibitor explains this intriguing inverse cell-density-dependent-cytotoxicity phenomenon as T3SS is known to be a key virulence factor associated with cytotoxicity and acute infection. The findings may provide useful clues for design and development of new strategies to combat this formidable bacterial pathogen. PMID:23555919

  10. Butyrylcholinesterase Deficiency Promotes Adipose Tissue Growth and Hepatic Lipid Accumulation in Male Mice on High-Fat Diet.

    PubMed

    Chen, Vicky Ping; Gao, Yang; Geng, Liyi; Stout, Michael B; Jensen, Michael D; Brimijoin, Stephen

    2016-08-01

    Despite numerous reports of relationships between weight gain and butyrylcholinesterase (BChE), this enzyme's role in the genesis of obesity remains unclear, but recent research points to strong links with ghrelin, the "hunger hormone." The availability of BChE knockout (KO) mice provides an opportunity to clarify the causal relationship between BChE and obesity onset. We now find that young KO mice have abnormally high plasma ghrelin levels that slowly decline during long-term high-fat feeding and ultimately drop below those in wild-type mice. On such a diet, the KO mice gained notably more weight, more white fat, and more hepatic fat than wild-type animals. In addition to a greater burden of hepatic triglycerides, the livers of these KO mice show distinctly higher levels of inflammatory markers. Finally, their energy expenditure proved to be lower than in wild-type mice despite similar activity levels and increased caloric intake. A gene transfer of mouse BChE with adeno-associated virus vector restored nearly all aspects of the normal phenotype. Our results indicate that BChE strongly affects fat metabolism, has an important impact on fat accumulation, and may be a promising tool for combating obesity. PMID:27300766

  11. High-latitude regions of Siberia and Northeast Russia in the Paleogene: Stratigraphy, flora, climate, coal accumulation

    NASA Astrophysics Data System (ADS)

    Akhmetiev, M. A.

    2015-07-01

    The geological structure and development history of superposed depressions on the Arctic coast of East Siberia and Bering Sea region (Chukotka, Koryakiya, northern Kamchatka) in the Early Paleogene are considered with the analysis of their flora and climatic parameters. The paleofloral analysis revealed thermophilic assemblages that reflect phases of maximum warming at the Paleocene-Eocene transition and in the Early Eocene. The appearance of thermophilic plants (Magnoliaceae, Myrtaceae, Lauraceae, Araliaceae, Loranthaceae, and others) in the Siberian segment of the Arctic region is explained by the stable atmospheric heat transfer from the Tethys to higher latitudes and absence of the latitudinal orographic barrier (Alpine-Himalayan belt). The plants migrated to high latitudes also along the meridional seaway that connected the Tethys with the Arctic Ocean via marine basins of the Eastern Paratethys, Turgai Strait, and West Siberia. The migration from the American continent was realized along the southern coast of Beringia under influence of a warm current flowing from low latitudes along the western coast of North America. The palm genus Sabal migrated to northern Kamchatka and Koryakiya precisely in this way via southern Alaska. In the Oligocene, shallow-water marine sediments in high-latitude regions were replaced by terrestrial facies. The Late Oligocene was marked by maximum cooling. Coal accumulation in Northeast Russia through the Paleogene is reviewed.

  12. Efficient purification and concentration of viruses from a large body of high turbidity seawater

    PubMed Central

    Sun, Guowei; Xiao, Jinzhou; Wang, Hongming; Gong, Chaowen; Pan, Yingjie; Yan, Shuling; Wang, Yongjie

    2014-01-01

    Marine viruses are the most abundant entities in the ocean and play crucial roles in the marine ecological system. However, understanding of viral diversity on large scale depends on efficient and reliable viral purification and concentration techniques. Here, we report on developing an efficient method to purify and concentrate viruses from large body of high turbidity seawater. The developed method characterizes with high viral recovery efficiency, high concentration factor, high viral particle densities and high-throughput, and is reliable for viral concentration from high turbidity seawater. Recovered viral particles were used directly for subsequent analysis by epifluorescence microscopy, transmission electron microscopy and metagenomic sequencing. Three points are essential for this method:•The sampled seawater (>150 L) was initially divided into two parts, water fraction and settled matter fraction, after natural sedimentation.•Both viruses in the water fraction concentrated by tangential flow filtration (TFF) and viruses isolated from the settled matter fraction were considered as the whole viral community in high turbidity seawater.•The viral concentrates were re-concentrated by using centrifugal filter device in order to obtain high density of viral particles. PMID:26150953

  13. High nitrate to phosphorus regime attenuates negative effects of rising pCO2 on total population carbon accumulation

    NASA Astrophysics Data System (ADS)

    Matthiessen, B.; Eggers, S. L.; Krug, S. A.

    2012-03-01

    The ongoing rise in atmospheric pCO2 and consequent increase in ocean acidification have direct effects on marine calcifying phytoplankton, which potentially alters carbon export. To date it remains unclear, firstly, how nutrient regime, in particular by coccolithophores preferred phosphate limitation, interacts with pCO2 on particulate carbon accumulation; secondly, how direct physiological responses on the cellular level translate into total population response. In this study, cultures of Emiliania huxleyi were full-factorially exposed to two different N:P regimes and three different pCO2 levels. Cellular biovolume and PIC and POC content significantly declined in response to pCO2 in both nutrient regimes. Cellular PON content significantly increased in the Redfield treatment and decreased in the high N:P regime. Cell abundance significantly declined in the Redfield and remained constant in the high N:P regime. We hypothesise that in the high N:P regime severe phosphorous limitation could be compensated either by reduced inorganic phosphorous demand and/or by enzymatic uptake of organic phosphorous. In the Redfield regime we suggest that enzymatic phosphorous uptake to supplement enhanced phosphorous demand with pCO2 was not possible and thus cell abundance declined. These hypothesised different physiological responses of E. huxleyi among the nutrient regimes significantly altered population carrying capacities along the pCO2 gradient. This ultimately led to the attenuated total population response in POC and PIC content and biovolume to increased pCO2 in the high N:P regime. Our results point to the fact that the physiological (i.e. cellular) PIC and POC response to ocean acidification cannot be linearly extrapolated to total population response and thus carbon export. It is therefore necessary to consider both effects of nutrient limitation on cell physiology and their consequences for population size when predicting the influence of coccolithophores on

  14. Design, Fabrication and Test of a High Efficiency Refractive Secondary Concentrator for Solar Applications

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.; Geng, Steven M.; Castle, Charles H.; Macosko, Robert P.

    2000-01-01

    Common to many of the space applications that utilize solar thermal energy such as electric power conversion, thermal propulsion, and furnaces, is a need for highly efficient, solar concentration systems. An effort is underway to develop the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced primary concentrators, the refractive secondary concentrator enables very high system concentration ratios (10,000 to 1) and very high temperatures (greater than 2000 K). Presented is an overview of the effort at the NASA Glenn Research Center to evaluate the performance of a prototype single crystal sapphire refractive secondary concentrator and to compare the performance with analytical models. The effort involves the design and fabrication of a secondary concentrator, design and fabrication of a calorimeter and its support hardware, calibration of the calorimeter, testing of the secondary concentrator in NASA Glenn's Tank 6 solar thermal vacuum facility, and comparing the test results with predictions. Test results indicate an average throughput efficiency of 87%. It is anticipated that reduction of a known reflection loss with an anti-reflective coating would result in a secondary concentrator throughput efficiency of approximately 93%.

  15. Impact of high dietary zinc on zinc accumulation, enzyme activity and proteomic profiles in the pancreas of piglets.

    PubMed

    Pieper, R; Martin, L; Schunter, N; Villodre Tudela, C; Weise, C; Klopfleisch, R; Zentek, J; Einspanier, R; Bondzio, A

    2015-04-01

    The exocrine pancreas plays an important role in zinc homeostasis. Feeding very high (2000-3000mgzinc/kg diet) levels of zinc oxide to piglets for short periods is a common practice in the swine industry to improve performance and prevent diseases. The impact on pancreatic function and possible side effects during long-term feeding of high dietary zinc levels are still poorly understood. A total of 54 weaned piglets were either fed with low (57mg/kg, LZn), normal (164mg/kg, NZn) or high (2425mg/kg, HZn) zinc concentration in the diets. After 4 weeks of feeding, ten piglets per treatment were euthanized and pancreas samples were taken. Tissue zinc concentration and metallothionein abundance was greater with HZn compared with NZn and LZn (P<0.05). Similarly, activity of α-amylase, lipase, trypsin and chymotrypsin was higher with HZn as compared with NZn and LZn diets (P<0.05), whereas elastase activity was unchanged. Total trolox equivalent antioxidative capacity of pancreas tissue was higher with HZn diets compared with the other treatments (P<0.05). Pancreatic protein profiles of NZn and HZn fed piglets were obtained by 2D-DIGE technique and revealed 15 differentially expressed proteins out of 2100 detected spots (P<0.05). The differentially expressed proteins aldose reductase, eukaryotic elongation factor II and peroxiredoxin III were confirmed by immunoblotting. Identified proteins include zinc finger-containing transcription factors and proteins mainly associated with oxidative stress response and signal transduction in HZn compared with NZn pigs. Histologic examination however showed no morphologic changes. The results suggest that long-term supply of very high dietary zinc increases zinc and metallothionein concentration, and digestive enzyme activity, but also triggers oxidative stress reactions in the pancreas of young pigs. The data provide new insights into pancreatic function under outbalanced zinc homeostasis. PMID:25744507

  16. Quantification of susceptibility change at high-concentrated SPIO-labeled target by characteristic phase gradient recognition.

    PubMed

    Zhu, Haitao; Nie, Binbin; Liu, Hua; Guo, Hua; Demachi, Kazuyuki; Sekino, Masaki; Shan, Baoci

    2016-05-01

    Phase map cross-correlation detection and quantification may produce highlighted signal at superparamagnetic iron oxide nanoparticles, and distinguish them from other hypointensities. The method may quantify susceptibility change by performing least squares analysis between a theoretically generated magnetic field template and an experimentally scanned phase image. Because characteristic phase recognition requires the removal of phase wrap and phase background, additional steps of phase unwrapping and filtering may increase the chance of computing error and enlarge the inconsistence among algorithms. To solve problem, phase gradient cross-correlation and quantification method is developed by recognizing characteristic phase gradient pattern instead of phase image because phase gradient operation inherently includes unwrapping and filtering functions. However, few studies have mentioned the detectable limit of currently used phase gradient calculation algorithms. The limit may lead to an underestimation of large magnetic susceptibility change caused by high-concentrated iron accumulation. In this study, mathematical derivation points out the value of maximum detectable phase gradient calculated by differential chain algorithm in both spatial and Fourier domain. To break through the limit, a modified quantification method is proposed by using unwrapped forward differentiation for phase gradient generation. The method enlarges the detectable range of phase gradient measurement and avoids the underestimation of magnetic susceptibility. Simulation and phantom experiments were used to quantitatively compare different methods. In vivo application performs MRI scanning on nude mice implanted by iron-labeled human cancer cells. Results validate the limit of detectable phase gradient and the consequent susceptibility underestimation. Results also demonstrate the advantage of unwrapped forward differentiation compared with differential chain algorithms for susceptibility

  17. Consumption of low doses of fat prevents the postprandial rise in chylomicron particle concentration and remnant accumulation in healthy normolipidaemic males

    PubMed Central

    James, Anthony P.; Mamo, John C.

    2012-01-01

    Chylomicron particles are continually synthesised and secreted from the intestine even in the absence of ingested fat. It is possible that following consumption of low doses of fat the basal level of chylomicron secretion and subsequent metabolism are sufficient to metabolise this fat without an increase in postprandial chylomicron concentrations. To test this hypothesis, healthy male subjects were randomised to receive, on three separate occasions, meals containing a range of doses of fat (average 8·1–19 g) and effects on postprandial lipaemia and chylomicron concentration were determined. Furthermore, to delineate the effect on lipid-rich v. lipid-poor (remnant) forms lipid levels were also determined in a density <1·006 g/ml fraction. Following consumption of the very low dose of fat the postprandial concentration of chylomicrons was unaltered, whereas following the medium dose postprandial chylomicron concentrations were significantly increased. Interestingly, this increase was only detected in the lipid-rich chylomicron fraction, with postprandial levels of chylomicron remnants remaining unchanged. In conclusion, it appears that consumption of what would be considered low to medium doses of fat are not associated with transient postprandial increases in chylomicron remnants in healthy male subjects. PMID:25191552

  18. Nitrogen concentration and dry matter accumulation in maize crop: Assessing maize nitrogen status with an allometric function and a chlorophyll meter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability to determine the minimum critical nitrogen (N) content in maize plants in order to obtain maximum growth is important to the management of the crop. To conduct plant-based N nutrition diagnosis in maize, it is essential to establish a critical N concentration ([N]), which is the minimum ...

  19. Effect of TiO2 nanoparticle-accumulated bilayer photoelectrode and condenser lens-assisted solar concentrator on light harvesting in dye-sensitized solar cells.

    PubMed

    Moon, Kook Joo; Lee, Sun Woo; Lee, Yong Hun; Kim, Ji Hoon; Ahn, Ji Young; Lee, Seung Jun; Lee, Deug Woo; Kim, Soo Hyung

    2013-01-01

    TiO2 nanoparticles (NPs) with a size of 240 nm (T240), used as a light-scattering layer, were applied on 25-nm-sized TiO2 NPs (T25) that were used as a dye-absorbing layer in the photoelectrodes of dye-sensitized solar cells (DSSCs). In addition, the incident light was concentrated via a condenser lens, and the effect of light concentration on the capacity of the light-scattering layer was systematically investigated. At the optimized focal length of the condenser lens, T25/T240 double layer (DL)-based DSSCs with the photoactive area of 0.36 cm2 were found to have the short circuit current (Isc) of 11.92 mA, the open circuit voltage (Voc) of 0.74 V, and power conversion efficiency (PCE) of approximately 4.11%, which is significantly improved when they were compared to the T25 single layer (SL)-based DSSCs without using a solar concentrator (the corresponding values were the Isc of 2.53 mA, the Voc of 0.69, and the PCE of 3.57%). Thus, the use of the optimized light harvesting structure in the photoelectrodes of DSSCs in conjunction with light concentration was found to significantly enhance the power output of DSSCs. PMID:23758633

  20. High Concentrate Diet Induced Mucosal Injuries by Enhancing Epithelial Apoptosis and Inflammatory Response in the Hindgut of Goats

    PubMed Central

    Tao, Shiyu; Duanmu, Yongqian; Dong, Haibo; Ni, Yingdong; Chen, Jie; Shen, Xiangzhen; Zhao, Ruqian

    2014-01-01

    Purpose It is widely accepted that lipopolysaccharide and volatile fatty acids (VFA) accumulate in the digestive tract of ruminants fed diets containing high portions of grain. Compared to the ruminal epithelium, the hindgut epithelium is composed of a monolayer structure that is more “leaky” for lipopolysaccharide and susceptible to organic acid-induced damage. The aim of this study was to investigate changes in epithelial structure, apoptosis and inflammatory response in the hindgut of goats fed a high-concentrate diet for 6 weeks. Experimental Design Eight local Chinese goats with rumen cannulas were randomly assigned to two groups: one group was fed a high-concentrate diet (65% concentrate of dry matter, HC) and the other group was fed a low-concentrate diet (35% concentrate of dry matter, LC) for 6 wks. Ruminal fluid, plasma, and hindgut mucosa tissues were collected. Histological techniques, real-time PCR and western blotting were used to evaluate the tissues structure, cell apoptosis and local inflammation in the hindguts. Results Feeding HC diet for 6 wks resulted in a significant decrease of ruminal pH (p<0.01), and ruminal lipopolysaccharide concentrations were significantly increased in HC goats (p<0.05). Obvious damage was observed to mucosal epithelium of the hindgut and the intercellular tight junctions in HC, but not in LC, goats. The expression of MyD88 and caspase-8 mRNA was increased in colonic epithelium of HC goats compared to LC (p<0.05), and the expression of TLR-4 and caspase-3 showed a tendency to increase. In the cecum, interleukin-1β mRNA expression was decreased (p<0.05), and caspase-3 showed a potential increase (p = 0.07) in HC goats. The level of NF-κB protein was increased in colonic epithelium of HC goats. Caspase-3 activity was elevated in both colon and cecum, whereas caspase-8 activity was statistically increased only in colon. Conclusions Feeding a high-concentrate diet to goats for 6 wks led to hindgut mucosal injuries

  1. High accumulation of PCDD, PCDF, and PCB congeners in marine mammals from Brazil: a serious PCB problem.

    PubMed

    Dorneles, Paulo R; Sanz, Paloma; Eppe, Gauthier; Azevedo, Alexandre F; Bertozzi, Carolina P; Martínez, María A; Secchi, Eduardo R; Barbosa, Lupércio A; Cremer, Marta; Alonso, Mariana B; Torres, João P M; Lailson-Brito, José; Malm, Olaf; Eljarrat, Ethel; Barceló, Damià; Das, Krishna

    2013-10-01

    Blubber samples from three delphinid species (false killer whale, Guiana and rough-toothed dolphin), as well as liver samples from franciscana dolphins were analyzed for dioxins and related compounds (DRCs). Samples were collected from 35 cetaceans stranded or incidentally captured in a highly industrialized and urbanized area (Southeast and Southern Brazilian regions). Dioxin-like PCBs accounted for over 83% of the total TEQ for all cetaceans. Non-ortho coplanar PCBs, for franciscanas (82%), and mono-ortho PCBs (up to 80%), for delphinids, constituted the groups of highest contribution to total TEQ. Regarding franciscana dolphins, significant negative correlations were found between total length (TL) and three variables, ΣTEQ-DRCs, ΣTEQ-PCDF and ΣTEQ non-ortho PCB. An increasing efficiency of the detoxifying activity with the growth of the animal may be a plausible explanation for these findings. This hypothesis is reinforced by the significant negative correlation found between TL and PCB126/PCB169 concentration ratio. DRC concentrations (ng/g lipids) varied from 36 to 3006, for franciscana dolphins, as well as from 356 to 30,776, for delphinids. The sum of dioxin-like and indicator PCBs varied from 34,662 to 279,407 ng/g lipids, for Guiana dolphins from Rio de Janeiro state, which are among the highest PCB concentrations ever reported for cetaceans. The high concentrations found in our study raise concern not only on the conservation of Brazilian coastal cetaceans, but also on the possibility of human health problem due to consumption of fish from Brazilian estuaries. PMID:23827355

  2. High concentration suspended sediment measurments using acontinuous fiber optic in-stream transmissometer

    SciTech Connect

    Campbell, Chris G.; Laycak, Danny T.; Hoppes, William; Tran,Nguyen T.; Shi, Frank G.

    2004-05-26

    Suspended sediment loads mobilized during high flow periods in rivers and streams are largely uncharacterized. In smaller and intermittent streams, a large storm may transport a majority of the annual sediment budget. Therefore monitoring techniques that can measure high suspended sediment concentrations at semi-continuous time intervals are needed. A Fiber optic In-stream Transmissometer (FIT) is presented for continuous measurement of high concentration suspended sediment in storm runoff. FIT performance and precision were demonstrated to be reasonably good for suspended sediment concentrations up to 10g/L. The FIT was compared to two commercially available turbidity devices and provided better precision and accuracy at both high and low concentrations. Both turbidity devices were unable to collect measurements at concentrations greater than 4 g/L. The FIT and turbidity measurements were sensitive to sediment particle size. Particle size dependence of transmittance and turbidity measurement poses the greatest problem for calibration to suspended sediment concentration. While the FIT was demonstrated to provide acceptable measurements of high suspended sediment concentrations, approaches to real-time suspended sediment detection need to address the particle size dependence in concentration measurements.

  3. Novel DDR Processing of Corn Stover Achieves High Monomeric Sugar Concentrations from Enzymatic Hydrolysis (230 g/L) and High Ethanol Concentration (10% v/v) During Fermentation

    SciTech Connect

    Chen, Xiaowen; Jennings, Ed; Shekiro, Joe; Kuhn, Erik M.; O'Brien, Marykate; Wang, Wei; Schell, Daniel J.; Himmel, Mike; Elander, Richard T.; Tucker, Melvin P.

    2015-04-03

    Distilling and purifying ethanol, butanol, and other products from second and later generation lignocellulosic biorefineries adds significant capital and operating cost for biofuels production. The energy costs associated with distillation affects plant gate and life cycle analysis costs. Lower titers in fermentation due to lower sugar concentrations from pretreatment increase both energy and production costs. In addition, higher titers decrease the volumes required for enzymatic hydrolysis and fermentation vessels. Therefore, increasing biofuels titers has been a research focus in renewable biofuels production for several decades. In this work, we achieved over 200 g/L of monomeric sugars after high solids enzymatic hydrolysis using the novel deacetylation and disc refining (DDR) process on corn stover. The high sugar concentrations and low chemical inhibitor concentrations from the DDR process allowed ethanol titers as high as 82 g/L in 22 hours, which translates into approximately 10 vol% ethanol. To our knowledge, this is the first time that 10 vol% ethanol in fermentation derived from corn stover without any sugar concentration or purification steps has been reported. Techno-economic analysis shows the higher titer ethanol achieved from the DDR process could significantly reduce the minimum ethanol selling price from cellulosic biomass.

  4. Cinnamaldehyde supplementation prevents fasting-induced hyperphagia, lipid accumulation, and inflammation in high-fat diet-fed mice.

    PubMed

    Khare, Pragyanshu; Jagtap, Sneha; Jain, Yachna; Baboota, Ritesh K; Mangal, Priyanka; Boparai, Ravneet K; Bhutani, Kamlesh K; Sharma, Shyam S; Premkumar, Louis S; Kondepudi, Kanthi K; Chopra, Kanwaljit; Bishnoi, Mahendra

    2016-01-01

    Cinnamaldehyde, a bioactive component of cinnamon, is increasingly gaining interest for its preventive and therapeutic effects against metabolic complications like type-2 diabetes. This study is an attempt to understand the effect of cinnamaldehyde in high-fat diet (HFD)-associated increase in fasting-induced hyperphagia and related hormone levels, adipose tissue lipolysis and inflammation, and selected cecal microbial count in mice. Cinnamaldehyde, at 40 µm dose, prevented lipid accumulation and altered gene expression toward lipolytic phenotype in 3T3-L1 preadipocyte cell lines. In vivo, cinnamaldehyde coadministration prevented HFD-induced body weight gain, decreased fasting-induced hyperphagia, as well as circulating leptin and leptin/ghrelin ratio. In addition to that, cinnamaldehyde altered serum biochemical parameters related to lipolysis, that is, glycerol and free fatty acid levels. At transcriptional level, cinnamaldehyde increased anorectic gene expression in hypothalamus and lipolytic gene expression in visceral white adipose tissue. Furthermore, cinnamaldehyde also decreased serum IL-1β and inflammatory gene expression in visceral white adipose tissue. However, cinnamaldehyde did not modulate the population of selected gut microbial (Lactobacillus, Bifidibaceria, and Roseburia) count in cecal content. In conclusion, cinnamaldehyde increased adipose tissue lipolysis, decreased fasting-induced hyperphagia, normalized circulating levels of leptin/ghrelin ratio, and reduced inflammation in HFD-fed mice, which augurs well for its antiobesity role. © 2016 BioFactors, 42(2):201-211, 2016. PMID:26893251

  5. Paternal High Fat Diet in Rats Leads to Renal Accumulation of Lipid and Tubular Changes in Adult Offspring.

    PubMed

    Chowdhury, Sabiha S; Lecomte, Virginie; Erlich, Jonathan H; Maloney, Christopher A; Morris, Margaret J

    2016-01-01

    Along with diabetes and obesity, chronic kidney disease (CKD) is increasing across the globe. Although some data support an effect of maternal obesity on offspring kidney, the impact of paternal obesity is unknown; thus, we have studied the effect of paternal obesity prior to conception. Male Sprague Dawley rats were fed chow diet or high fat diet (HFD) for 13-14 weeks before mating with chow-fed females. Male offspring were weaned onto chow and killed at 27 weeks for renal gene expression and histology. Fathers on HFD were 30% heavier than Controls at mating. At 27 weeks of age offspring of obese fathers weighed 10% less; kidney triglyceride content was significantly increased (5.35 ± 0.84 vs. 2.99 ± 0.47 μg/mg, p < 0.05, n = 8 litters per group. Histological analysis of the kidney demonstrated signs of tubule damage, with significantly greater loss of brush border, and increased cell sloughing in offspring of obese compared to Control fathers. Acat1, involved in entry of fatty acid for beta-oxidation, was significantly upregulated, possibly to counteract increased triglyceride storage. However other genes involved in lipid metabolism, inflammation and kidney injury showed no changes. Paternal obesity was associated with renal triglyceride accumulation and histological changes in tubules, suggesting a mild renal insult in offspring, who may be at risk of developing CKD. PMID:27563922

  6. Korean Pine Nut Oil Attenuated Hepatic Triacylglycerol Accumulation in High-Fat Diet-Induced Obese Mice.

    PubMed

    Park, Soyoung; Shin, Sunhye; Lim, Yeseo; Shin, Jae Hoon; Seong, Je Kyung; Han, Sung Nim

    2016-01-01

    Korean pine nut oil (PNO) has been reported to influence weight gain and lipid metabolism. We examined whether PNO replacement in a high-fat diet (HFD) can ameliorate HFD-induced hepatic steatosis. Five-week-old male C57BL mice were fed control diets containing 10% of the energy from fat from PNO or soybean oil (SBO) (PC, SC) or HFDs with 45% of the energy from fat, with 10% from PNO or SBO and 35% from lard (PHFD, SHFD), for 12 weeks. Body weight gain and amount of white adipose tissue were lower in PHFD (10% and 18% lower, respectively) compared with SHFD. Hepatic triacylglycerol (TG) level was significantly lower in PHFD than the SHFD (26% lower). PNO consumption upregulated hepatic ACADL mRNA levels. The hepatic PPARG mRNA level was lower in the PC than in the SC. Expression of the sirtuin (SIRT) 3 protein in white adipose tissue was down-regulated in the SHFD and restored in the PHFD to the level in the lean control mice. SIRT 3 was reported to be upregulated under conditions of caloric restriction (CR) and plays a role in regulating mitochondrial function. PNO consumption resulted in lower body fat and hepatic TG accumulation in HFD-induced obesity, which seemed to be associated with the CR-mimetic response. PMID:26805879

  7. Korean Pine Nut Oil Attenuated Hepatic Triacylglycerol Accumulation in High-Fat Diet-Induced Obese Mice

    PubMed Central

    Park, Soyoung; Shin, Sunhye; Lim, Yeseo; Shin, Jae Hoon; Seong, Je Kyung; Han, Sung Nim

    2016-01-01

    Korean pine nut oil (PNO) has been reported to influence weight gain and lipid metabolism. We examined whether PNO replacement in a high-fat diet (HFD) can ameliorate HFD-induced hepatic steatosis. Five-week-old male C57BL mice were fed control diets containing 10% of the energy from fat from PNO or soybean oil (SBO) (PC, SC) or HFDs with 45% of the energy from fat, with 10% from PNO or SBO and 35% from lard (PHFD, SHFD), for 12 weeks. Body weight gain and amount of white adipose tissue were lower in PHFD (10% and 18% lower, respectively) compared with SHFD. Hepatic triacylglycerol (TG) level was significantly lower in PHFD than the SHFD (26% lower). PNO consumption upregulated hepatic ACADL mRNA levels. The hepatic PPARG mRNA level was lower in the PC than in the SC. Expression of the sirtuin (SIRT) 3 protein in white adipose tissue was down-regulated in the SHFD and restored in the PHFD to the level in the lean control mice. SIRT 3 was reported to be upregulated under conditions of caloric restriction (CR) and plays a role in regulating mitochondrial function. PNO consumption resulted in lower body fat and hepatic TG accumulation in HFD-induced obesity, which seemed to be associated with the CR-mimetic response. PMID:26805879

  8. Accumulated Metabolites of Hydroxybutyric Acid Serve as Diagnostic and Prognostic Biomarkers of Ovarian High-Grade Serous Carcinomas.

    PubMed

    Hilvo, Mika; de Santiago, Ines; Gopalacharyulu, Peddinti; Schmitt, Wolfgang D; Budczies, Jan; Kuhberg, Marc; Dietel, Manfred; Aittokallio, Tero; Markowetz, Florian; Denkert, Carsten; Sehouli, Jalid; Frezza, Christian; Darb-Esfahani, Silvia; Braicu, Elena Ioana

    2016-02-15

    Ovarian cancer is a heterogeneous disease of low prevalence, but poor survival. Early diagnosis is critical for survival, but it is often challenging because the symptoms of ovarian cancer are subtle and become apparent only during advanced stages of the disease. Therefore, the identification of robust biomarkers of early disease is a clinical priority. Metabolomic profiling is an emerging diagnostic tool enabling the detection of biomarkers reflecting alterations in tumor metabolism, a hallmark of cancer. In this study, we performed metabolomic profiling of serum and tumor tissue from 158 patients with high-grade serous ovarian cancer (HGSOC) and 100 control patients with benign or non-neoplastic lesions. We report metabolites of hydroxybutyric acid (HBA) as novel diagnostic and prognostic biomarkers associated with tumor burden and patient survival. The accumulation of HBA metabolites caused by HGSOC was also associated with reduced expression of succinic semialdehyde dehydrogenase (encoded by ALDH5A1), and with the presence of an epithelial-to-mesenchymal transition gene signature, implying a role for these metabolic alterations in cancer cell migration and invasion. In conclusion, our findings represent the first comprehensive metabolomics analysis in HGSOC and propose a new set of metabolites as biomarkers of disease with diagnostic and prognostic capabilities. PMID:26685161

  9. Accumulated metabolites of hydroxybutyric acid serve as diagnostic and prognostic biomarkers of ovarian high-grade serous carcinomas

    PubMed Central

    Hilvo, Mika; de Santiago, Ines; Gopalacharyulu, Peddinti; Schmitt, Wolfgang D.; Budczies, Jan; Kuhberg, Marc; Dietel, Manfred; Aittokallio, Tero; Markowetz, Florian; Denkert, Carsten; Sehouli, Jalid; Frezza, Christian

    2016-01-01

    Ovarian cancer is a heterogeneous disease of low prevalence, but poor survival. Early diagnosis is critical for survival, but is often challenging because the symptoms of ovarian cancer are subtle and become apparent only during advanced stages of the disease. Therefore, the identification of robust biomarkers of early disease is a clinical priority. Metabolomic profiling is an emerging diagnostic tool enabling the detection of biomarkers reflecting alterations in tumor metabolism, a hallmark of cancer. In this study, we performed metabolomic profiling of serum and tumor tissue from 158 patients with high-grade serous ovarian cancer (HGSOC) and 100 control patients with benign or non-neoplastic lesions. We report metabolites of hydroxybutyric acid (HBA) as novel diagnostic and prognostic biomarkers associated with tumor burden and patient survival. The accumulation of HBA metabolites caused by HGSOC was also associated with reduced expression of succinic semialdehyde dehydrogenase (encoded by ALDH5A1), and with the presence of an epithelial-to-mesenchymal transition (EMT) gene signature, implying a role for these metabolic alterations in cancer cell migration and invasion. In conclusion, our findings represent the first comprehensive metabolomics analysis in HGSOC and propose a new set of metabolites as biomarkers of disease with diagnostic and prognostic capabilities. PMID:26685161

  10. High variability of stress accumulation, seismic and aseismic release mode along the Peru-Ecuador subduction zone (Invited)

    NASA Astrophysics Data System (ADS)

    Nocquet, J.; Villegas, J. C.; Chlieh, M.; Mothes, P. A.; Rolandone, F.; Jarrín, P.; Cisneros, D.; Vallee, M.

    2013-12-01

    Most geodetic measurements of interseismic strain along subduction zones have led to the view of coupled asperities of variable size usually separated by narrower zones of low coupling. Along the western margin of South America, fast convergence of the oceanic Nazca plate has repeatedly produced M>8 earthquakes and three of the ten largest megathrust earthquakes since 1900. Contrasting with this behavior, the segment comprised between central Peru and central Ecuador has not experienced any great earthquake for at least five centuries. New GPS measurements in Peru and Ecuador first highlight that a along a ~1000km long segment, convergence is predominantly accommodated by aseismic creep along the plate interface, with possible coupling occurring at shallow depth, close to the trench. This area is bounded by highly locked segments, which produced M>8.5 earthquakes in central Peru and northern Ecuador. While the observed low interseismic coupling explains the lack of great earthquakes, this area has experienced two earthquakes that share the characteristics of tsunamigenic earthquakes, indicating a correlation between the mode of stress accumulation along the plate interface and its release. Finally, we have observed several episodes of slow slip, sometimes associated with intense, micro to moderate seismicity. These observations suggest a specific behavior for this segment, which contrasts with the behavior of the neighboring segments.

  11. High level accumulation of soluble diphtheria toxin mutant (CRM197) with co-expression of chaperones in recombinant Escherichia coli.

    PubMed

    Mahamad, Pornpimol; Boonchird, Chuenchit; Panbangred, Watanalai

    2016-07-01

    CRM197 is the diphtheria toxin mutant used in many conjugate vaccines. A fusion CRM197 (fCRM197) containing all the tags conferred by the pET32a vector was produced as a soluble protein in Escherichia coli co-expressing several chaperone proteins in conjunction with low temperature cultivation. Trigger factor (Tf) enhanced formation of soluble fCRM197 (150.69 ± 8.95 μg/mL) to a greater degree than other chaperones when fCRM197 expression was induced at 25 °C for 12 h. However, prolonged cultivation resulted in a progressive reduction of fCRM197 accumulation. In contrast, at 15 °C cells, with or without Tf, fCRM197 accumulated to the highest level at 48 h (153.70 ± 13.14 μg/mL and 150.07 ± 8.13 μg/mL, respectively). Transmission electron microscopy (TEM) demonstrated that the formation of inclusion protein as well as cell lysis was reduced in cultures grown at 15 °C. Cell viability was substantially reduced in cells expressing Tf, compared to cultures without Tf, when fCRM197 was induced at 25 °C. The viability of Tf-expressing cells was enhanced when cultured at 15 °C. Both purified fCRM197 and CRM197 efficiently digested lambda DNA (λDNA) at 37 °C (92.78 and 97.45 %, respectively). Digestion efficiency of fCRM197 and CRM197 was reduced at 25 °C (80.80 and 62.73 %, respectively) and at 15 °C (7.34 and 24.79 %, respectively). These results demonstrating nuclease activity, enhanced cell lysis, and reduced cell viability are consistent with the finding of lower fCRM197 yield when cultivation and induction times were prolonged at 25 °C. The present work provides a procedure for the high-level production of soluble fCRM197 using E. coli as a heterologous host. PMID:27020286

  12. Ecotoxicological investigation of the effect of accumulation of PAH and possible impact of dispersant in resting high arctic copepod Calanus hyperboreus.

    PubMed

    Nørregaard, Rasmus Dyrmose; Gustavson, Kim; Møller, Eva Friis; Strand, Jakob; Tairova, Zhanna; Mosbech, Anders

    2015-10-01

    Due to high lipid content and a slow metabolism, there is a higher risk of bioaccumulation of oil compounds in Arctic than in temperate copepods. There is also a concern that the bioavailability of oil compounds is higher when oil is dispersed with dispersants. The purpose of this project was to increase the knowledge on how the use of dispersants on an oil spill may affect the passive uptake of PAHs in resting high arctic copepods using Calanus hyperboreus as a model organism. To evaluate this, resting high arctic C. hyperboreus were caught in Disko Bay at>250 meters depth, November 2013, and subsequent experimental work was initiated immediately after, at nearby Arctic Station at Disko Island Western Greenland. C. hyperboreus females were incubated in phenanthrene (111, 50 and 10 nM), pyrene (57, 28 and 6 nM) and benzo(a) pyrene (10, 5 and 1 nM) for three days in treatments with and without oil (corn oil) and dispersant (AGMA DR372). After exposure, the highest measured concentrations of respectively phenanthrene, pyrene and benzo(a) pyrene in the copepods were 129, 30 and 6 nmol PAH g female(-1). Results showed that with addition of oil and dispersant to the water, the accumulation of PAH was significantly reduced, due to the deposition of the PAHs in the oil phase, decreasing the available PAHs for copepod uptake. While PAH metabolites and a depuration of the PAHs were observed, the copepods still contained PAHs after 77 days of incubation in clean seawater. Differences of treatments with and without oil and dispersant on the egg production were not statistically conclusive, although it is the most likely an effect of the highly variable day-to-day egg production between individual copepods. Equally, although there was an indication that the addition of dispersant and oil increased the mortality rate, there was no statistical difference. PMID:26253790

  13. High altitude AM0 testing of PV concentrator lens elements. [Air Mass Zero

    NASA Technical Reports Server (NTRS)

    Piszczor, M. F.; Brinker, D. J.; Boyer, E. O.; Mcknight, R. C.; Ranaudo, R. J.

    1990-01-01

    Recently, the NASA Lewis Research Center modified its Lear High Altitude Test Facility to fly two prototype ENTECH minidome Fresnel lens photovoltaic concentrator elements. The tests were highly successful, and the results verified the ability of the Lear High Altitude Facility to measure the optical performance of individual concentrator lens elements and concentrator/cell combinations at near AM0 insolation conditions. The two concentrator lenses flown achieved optical efficiencies, based on a gallium arsenide concentrator cell response, of 89.8 percent and 90.0 percent. The flights demonstrated the ability of the aircraft to maintain the pointing accuracy required to obtain useful data. With proper alignment of the collimating tube and the pilot's sunsight, this facility could easily maintain a pointing accuracy of + or - 0.5 deg for a sufficiently long time to obtain accurate, reproducible results.

  14. Effect of digestion time on anaerobic digestion with high ammonia concentration

    NASA Astrophysics Data System (ADS)

    Oktavitri, Nur Indradewi; Purnobasuki, Hery; Kuncoro, Eko Prasetyo; Purnamasari, Indah; Semma Hadinnata, P.

    2016-03-01

    Anaerobic digestion was developed to treat high concentration organic compound efficiently in certain Digestion Time (DT). High ammonia concentration could influenced removal organic compound in digestion. This bench scale study investigated the effect of digestion time on anaerobic batch reactor with high ammonia concentration. Total Ammonia Nitrogen (TAN) concentration was adjusted 4000 and 5000 mg/1, Digestion time was ranged from 0-26 d, operation temperature was ranged from 28-29°C, inoculum was collected from slaughter house sludge. The degradation of Chemical Oxygen Demand (COD) correlated with digestion time. The concentration of TAN from synthetic wastewater contain 5000 mg/1 of TAN more fluctuated than those use 4000 mg/1 of TAN. However, the biogas production from wastewater contained 4000 mg/1 of TAN gradually increased until 24 d of DT. The reactor contain 5000 mg/1 of TAN only growth until 12 d and steady state at over 12 d of digestion time.

  15. Triglyceride accumulation and fatty acid profile changes in Chlorella (Chlorophyta) during high pH-induced cell cycle inhibition

    SciTech Connect

    Guckert, J.B.; Cooksey, K.E. )

    1990-03-01

    Alkaline pH stress resulted in triglyceride (TG) accumulation in Chlorella CHLOR1 and was independent of medium nitrogen or carbon levels. Based on morphological observations, alkaline pH inhibited autospore release, thus increasing the time for cell cycle completion. Autospore release has been postulated to coincide with TG utilization within the microalgal cell division cycle. The alkaline pH stress affected lipid accumulation by inhibiting the cell division cycle prior to autospore release and, therefore, prior to TG utilization. Cells inhibited in this manner showed an increase in TG accumulation but a decrease in both membrane lipid classes (glycolipid and polar lipid). Unlike TG fatty acid profiles, membrane lipid fatty acid profiles were not stable during TG accumulation. The membrane profiles became similar to the TG, i.e. less unsaturated than in the membrane lipids of unstressed control cells.

  16. Metals and metalloids in fruits of tomatoes (Solanum lycopersicum) and their cultivation soils in the Basque Country: concentrations and accumulation trends.

    PubMed

    Rodriguez-Iruretagoiena, Azibar; Trebolazabala, Josu; Martinez-Arkarazo, Irantzu; de Diego, Alberto; Madariaga, Juan Manuel

    2015-04-15

    The concentrations of several elements (Al, Fe, As, Cu, Cd, Co, Cr, Mn, Ni, Pb, Sn, V, and Zn) were measured in soils and the edible part of different vegetables (tomatoes (Solanum lycopersicum "Raf") peppers (Capsicum annuum), chards (Betavulgaris var. cicla), artichokes (Cynarascholymus)) and fruits (Raspberries (Rubusidaeus)) from 13 orchards in the Basque Country affected by different pollution sources. Multivariate analysis of data was used to look for possible correlations between metals in soil and metals in the edible part of the plant. Only manganese showed a correlation significantly different from zero. The metal concentrations found in the edible part were always below the upper limits recommended by the European legislation in force. The Bioaccumulation Index was used to investigate how efficient the plant is to uptake an element from the cultivation soil and to preserve its edible part from the element. PMID:25466128

  17. Advanced process development for high reflector coatings on solar concentrator panels. Final letter report

    SciTech Connect

    Martin, P.M.; Stewart, C.D.; Bennett, W.D.; Johnston, J.W.

    1996-10-01

    Objectives were to develop and demonstrate the manufacturing process for vacuum deposition of low-cost thin-film high reflectance coatings onto large solar concentrator panels; demonstrate thin-film deposition processes for commercialization of this technology by United Solar Technologies (UST); apply reflective coatings to solar concentrator panels for prototype application by UST.

  18. Plasma lipoprotein composition in alcoholic hepatitis: accumulation of apolipoprotein E-rich high density lipoprotein and preferential reappearance of "light'-HDL during partial recovery.

    PubMed

    Weidman, S W; Ragland, J B; Sabesin, S M

    1982-05-01

    Abnormal lipoproteins accumulate in the plasma of alcoholic hepatitis patients in association with a deficiency of the cholesterol esterifying enzyme, lecithin:cholesterol acyl-transferase. Most of these abnormal lipoproteins are found in the d > 1.006 g/ml density fraction. To investigate the composition and morphology of the lipoproteins at various times during the illness in four patients, we have employed density gradient ultracentrifugation combined with analyses of gradient fractions by polyacrylamide gel electrophoresis, electroimmunoassay, and electron microscopy. At the onset of the illness, plasma cholesteryl esters ranged from 19-34% of total cholesterol; high density lipoprotein (HDL) cholesterol and apoA-I, the major HDL apoprotein, were <10% of normal; and most of the d > 1.006 g/ml triglycerides and phospholipids were found in the LDL density region. A linear correlation (r = 0.964, P < 0.001) was found between the d > 1.006 g/ml apoB concentration and the summation of the triglyceride and esterified cholesterol for that fraction, indicating a constant ratio of apoB to the summation of these two "core lipids". ApoA-I was primarily found in the fraction d > 1.18 g/ml (HDL(3) and VHDL) but not at all in the HDL(2) density range of the gradient. No cholesteryl esters were present in the apoA-I containing fractions. In contrast to normal, large amounts of apoE accumulated in lipoproteins isolated at d 1.055-1.114 g/ml. The apoE-rich fractions contained primarily phospholipids and unesterified cholesterol; they appeared by electron microscopy to be mixtures of spherical particles, vesicular particles, and chains of bilamellar discs. Analyses of the density gradient fractions by SDS polyacrylamide gel electrophoresis under reducing conditions indicated that apoA-II levels and distribution paralleled apoA-I, not apoE, providing evidence against appreciable concentrations of apoE-apoA-II complexes. During partial recovery from alcoholic hepatitis in three

  19. Impaired clearance of accumulated lysosomal glycogen in advanced Pompe disease despite high-level vector-mediated transgene expression

    PubMed Central

    Sun, Baodong; Zhang, Haoyue; Bird, Andrew; Li, Songtao; Young, Sarah P.; Koeberl, Dwight D.

    2013-01-01

    Background Infantile-onset glycogen storage disease type II (GSD-II; Pompe disease; MIM 232300) causes death early in childhood from cardiorespiratory failure in absence of effective treatment, whereas late-onset Pompe disease causes a progressive skeletal myopathy. The limitations of enzyme replacement therapy could potentially be addressed with adeno-associated virus (AAV) vector-mediated gene therapy. Methods AAV vectors containing tissue-specific regulatory cassettes, either liver-specific or muscle-specific, were administered to 12 and 17 month old Pompe disease mice to evaluate the efficacy of gene therapy in advanced Pompe disease. Biochemical correction was evaluated through GAA activity and glycogen content analyses of the heart and skeletal muscle. Western blotting, urinary biomarker, and Rotarod performance were evaluated following vector administration. Results The AAV vector containing the liver-specific regulatory cassette secreted high-level hGAA into the blood and corrected glycogen storage in the heart and diaphragm. The biochemical correction of the heart and diaphragm was associated with efficacy, as reflected by increased Rotarod performance; however, the clearance of glycogen from skeletal muscles was relatively impaired, in comparison with younger Pompe disease mice. An alternative vector containing a muscle-specific regulatory cassette transduced skeletal muscle with high efficiency, but also failed to achieve complete clearance of accumulated glycogen. Decreased transduction of the heart and liver in older mice, especially in females, was implicated as a cause for reduced efficacy in advanced Pompe disease. Conclusion The impaired efficacy of AAV vector-mediated gene therapy in old Pompe disease mice emphasized the need for early treatment to achieve full efficacy. PMID:19621331

  20. Emodin ameliorates high-fat-diet induced insulin resistance in rats by reducing lipid accumulation in skeletal muscle.

    PubMed

    Cao, Yanni; Chang, Shufang; Dong, Jie; Zhu, Shenyin; Zheng, Xiaoying; Li, Juan; Long, Rui; Zhou, Yuanda; Cui, Jianyu; Zhang, Ye

    2016-06-01

    Emodin, an anthraquinone derivative isolated from root and rhizome of Rheum palmatum, has been reported to have promising anti-diabetic activity. The present study was to explore the possible mechanism of emodin to ameliorate insulin resistance. Insulin resistance was induced by feeding a high fat diet to Sprague-Dawley rats. The blood glucose and lipid profiles in serum were measured by an enzymatic method, and a hyperinsulinaemic-euglycaemic clamp was used to evaluate insulin resistance. L6 cells were cultured and treated with palmitic acid and emodin. The lipid content was assayed in the soleus muscle and L6 cells by Oil Red O staining. Western blot, qRT-PCR, and immunohistochemical staining were used to detect the following in the rat soleus muscle and L6 cells: protein levels, mRNA levels of FATP1, FATP4, transporter fatty acid translocase (FAT/CD36), and plasma membrane-associated fatty acid protein (FABPpm). We found that blood glucose, triglyceride (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly decreased in the emodin group. Oil Red O staining and the level of TG in skeletal muscle and L6 cells confirmed that lipid deposition decreased after treatment with emodin. Furthermore, the protein levels and mRNA levels of FATP1 in skeletal muscle and in L6 cells of rats were significantly decreased, yet the protein levels and mRNA levels of FATP4, FAT/CD36 and FABPpm did not drop off significantly. The study suggest that emodin ameliorates insulin resistance by reducing FATP1-mediated skeletal muscle lipid accumulation in rats fed a high fat diet. PMID:27020550

  1. Mature-stem expression of a silencing-resistant sucrose isomerase gene drives isomaltulose accumulation to high levels in sugarcane.

    PubMed

    Mudge, Stephen R; Basnayake, Shiromi W V; Moyle, Richard L; Osabe, Kenji; Graham, Michael W; Morgan, Terence E; Birch, Robert G

    2013-05-01

    Isomaltulose (IM) is a natural isomer of sucrose. It is widely approved as a food with properties including slower digestion, lower glycaemic index and low cariogenicity, which can benefit consumers. Availability is currently limited by the cost of fermentative conversion from sucrose. Transgenic sugarcane plants with developmentally-controlled expression of a silencing-resistant gene encoding a vacuole-targeted IM synthase were tested under field conditions typical of commercial sugarcane cultivation. High yields of IM were obtained, up to 483 mm or 81% of total sugars in whole-cane juice from plants aged 13 months. Using promoters from sugarcane to drive expression preferentially in the sugarcane stem, IM levels were consistent between stalks and stools within a transgenic line and across consecutive vegetative field generations of tested high-isomer lines. Germination and early growth of plants from setts were unaffected by IM accumulation, up to the tested level around 500 mm in flanking stem internodes. These are the highest yields ever achieved of value-added materials through plant metabolic engineering. The sugarcane stem promoters are promising for strategies to achieve even higher IM levels and for other applications in sugarcane molecular improvement. Silencing-resistant transgenes are critical to deliver the potential of these promoters in practical sugarcane improvement. At the IM levels now achieved in field-grown sugarcane, direct production of IM in plants is feasible at a cost approaching that of sucrose, which should make the benefits of IM affordable on a much wider scale. PMID:23297683

  2. A loss-of-function allele of OsHMA3 associated with high cadmium accumulation in shoots and grain of Japonica rice cultivars.

    PubMed

    Yan, Jiali; Wang, Peitong; Wang, Peng; Yang, Meng; Lian, Xingming; Tang, Zhong; Huang, Chao-Feng; Salt, David E; Zhao, Fang Jie

    2016-09-01

    Excessive cadmium (Cd) accumulation in rice poses a risk to food safety. OsHMA3 plays an important role in restricting Cd translocation from roots to shoots. A non-functional allele of OsHMA3 has been reported in some Indica rice cultivars with high Cd accumulation, but it is not known if OsHMA3 allelic variation is associated with Cd accumulation in Japonica cultivars. In this study, we identified a Japonica cultivar with consistently high Cd accumulation in shoots and grain in both field and greenhouse experiments. The cultivar possesses an OsHMA3 allele with a predicted amino acid mutation at the 380(th) position from Ser to Arg. The haplotype had no Cd transport activity when the gene was expressed in yeast, and the allele did not complement a known nonfunctional allele of OsHMA3 in F1 test. The allele is present only in temperate Japonica cultivars among diversity panels of 1483 rice cultivars. Different cultivars possessing this allele showed greatly increased root-to-shoot Cd translocation and a shift in root Cd speciation from Cd-S to Cd-O bonding determined by synchrotron X-ray absorption spectroscopy. Our study has identified a new loss-of-function allele of OsHMA3 in Japonica rice cultivars leading to high Cd accumulation in shoots and grain. PMID:27038090

  3. Investigating cold gelation properties of recombined highly concentrated micellar casein concentrate and cream for use in cheese making.

    PubMed

    Lu, Y; McMahon, D J; Vollmer, A H

    2016-07-01

    Highly concentrated micellar casein concentrate (HC-MCC), a potential ingredient for cheese making, contains ~20% casein with ~70% of serum proteins removed by microfiltration and diafiltration of skim milk, followed by vacuum evaporation. Our objective was to investigate cold gelation properties of recombined concentrated milk (RCM) by mixing thawed frozen HC-MCC and cream under different casein levels, pH, and protein-to-fat ratios, and with addition of sodium citrate or calcium. The HC-MCC was recombined with cream using low shear at 50°C for 30 min, and rheological measurements were conducted. Cold-gelling temperature [the temperature at which storage modulus (G')=loss modulus (G″)] was linearly correlated with casein levels from 8.6 to 11.5% (R(2)=0.71), pH from 6.6 to 7.0 (R(2)=0.96), and addition of sodium citrate from 0 to 0.36mmol/g of casein (R(2)=0.80). At pH 7.0, gelation occurred at 12, 26, and 38°C with 9, 10, and 11% casein, respectively. At pH 6.6, 6.8, and 7.0, RCM with 12% casein gelled at a mean temperature of 12, 26, and 37°C, respectively. Adding calcium chloride at 0.17mmol/g of casein significantly increased cold-gelling temperature from 18 to ≥50°C, whereas no significant change was observed at levels up to 0.12mmol/g of casein. Different protein to fat ratios ranging from 0.8 to 1.2 did not significantly influence gelling temperature. In transmission electron micrographs of RCM with 12% casein, casein micelles were nonspherical and partially dissociated into small protein strands. Upon addition of calcium chloride at 0.21mmol/g of casein, casein micelles were more spherical and retained colloidal structure with the presence of aggregated casein micelles. These gelation processes of RCM with or without addition of trisodium citrate were both reversible. We propose that cold gelation of RCM occurs when protein strands that have been partially released from the casein micelles entangle, restrict their mobility, and form a fine

  4. Differences in nitrite-oxidizing communities and kinetics in a brackish environment after enrichment at low and high nitrite concentrations.

    PubMed

    Tangkitjawisut, Wipasanee; Limpiyakorn, Tawan; Powtongsook, Sorawit; Pornkulwat, Preeyaporn; Suwannasilp, Benjaporn Boonchayaanant

    2016-04-01

    Nitrite accumulation in shrimp ponds can pose serious adverse effects to shrimp production and the environment. This study aims to develop an effective process for the enrichment of ready-to-use nitrite-oxidizing bacteria (NOB) inocula that would be appropriate for nitrite removal in brackish shrimp ponds. To achieve this objective, the effects of nitrite concentrations on NOB communities and nitrite oxidation kinetics in a brackish environment were investigated. Moving-bed biofilm sequencing batch reactors and continuous moving-bed biofilm reactors were used for the enrichment of NOB at various nitrite concentrations, using sediment from brackish shrimp ponds as seed inoculum. The results from NOB population analysis with quantitative polymerase chain reaction (qPCR) show that only Nitrospira were detected in the sediment from the shrimp ponds. After the enrichment, both Nitrospira and Nitrobacter coexisted in the reactors controlling effluent nitrite at 0.1 and 0.5 mg-NO2(-)-N/L. On the other hand, in the reactors controlling effluent nitrite at 3, 20, and 100 mg-NO2(-)-N/L, Nitrobacter outcompeted Nitrospira in many orders of magnitude. The half saturation coefficients (Ks) for nitrite oxidation of the enrichments at low nitrite concentrations (0.1 and 0.5 mg-NO2(-)-N/L) were in the range of 0.71-0.98 mg-NO2(-)-N/L. In contrast, the K(s) values of NOB enriched at high nitrite concentrations (3, 20, and 100 mg-NO2(-)-N/L) were much higher (8.36-12.20 mg-NO2(-)-N/L). The results suggest that the selection of nitrite concentrations for the enrichment of NOB inocula can significantly influence NOB populations and kinetics, which could affect the effectiveness of their applications in brackish shrimp ponds. PMID:27090693

  5. Argon, oxygen, and boron isotopic evidence documenting 40ArE accumulation in phengite during water-rich high-pressure subduction metasomatism of continental crust

    NASA Astrophysics Data System (ADS)

    Menold, Carrie A.; Grove, Marty; Sievers, Natalie E.; Manning, Craig E.; Yin, An; Young, Edward D.; Ziegler, Karen

    2016-07-01

    were even older, exceeding the time of eclogite formation by a factor of 1.7. In contrast, lower pressure retrograde muscovite present within the host gneiss and in discrete shear zones cutting the selvage yield 40Ar/39Ar ages that were younger than the time of HP metamorphism and consistent with regional cooling age patterns. Our observation of high 40ArE concentrations in phengite from schistose rocks infiltrated by regionally extensive fluids at HP conditions runs contrary to widely held expectations. Conventional wisdom dictates that low phengite/fluid partition coefficients for argon (Dphg/fluid Ar =10-3to10-5) coupled with the dry, closed systems conditions that are widely reported to characterize HP metamorphism of continental crust explains why high concentrations of 40ArE partitions are able to accumulate within phengite. We alternatively propose that phengite/fluid partition coefficients for argon increase linearly with pressure to values as high as 10-2 to allow phengites to accumulate large amounts of 40ArE from aqueous fluids under HP to UHP conditions.

  6. A High-Efficiency Refractive Secondary Solar Concentrator for High Temperature Solar Thermal Applications

    NASA Technical Reports Server (NTRS)

    Piszczor, Michael F., Jr.; Macosko, Robert P.

    2000-01-01

    A refractive secondary solar concentrator is a non-imaging optical device that accepts focused solar energy from a primary concentrator and redirects that light, by means of refraction and total internal reflection (TIR) into a cavity where the solar energy is used for power and/or propulsion applications. This concept offers a variety of advantages compared to typical reflective secondary concentrators (or the use of no secondary at all): higher optical efficiency, minimal secondary cooling requirements, a smaller cavity aperture, a reduction of outgassing from the cavity and flux tailoring of the solar energy within the heat receiver. During the past 2 years, NASA Lewis has been aggressively developing this concept in support of the NASA Marshall Shooting Star Flight Experiment. This paper provides a brief overview of the advantages and technical challenges associated with the development of a refractive secondary concentrator and the fabrication of a working unit in support of the flight demonstration program.

  7. Concentrator Systems

    NASA Astrophysics Data System (ADS)

    Luque-Heredia, Ignacio; Luque, Antonio

    2015-10-01

    The following sections are included: * Introduction * The early development of CPV * Concentrator solar cells * Optics for photovoltaic concentrators * Photovoltaic concentration modules * Tracking systems for photovoltaic concentration * High-concentration systems * Rating and performance * Cost considerations * Conclusions * References

  8. Highly Variable Holocene Antarctic Climate: A High-Resolution Marine Geochemical Record of Surface and Export Production, Terrigenous Provenance, and Terrigenous Accumulation from the Palmer Deep, West Antarctic Peninsula.

    NASA Astrophysics Data System (ADS)

    Kryc, K. A.; Murray, R. W.; Dunbar, R. B.

    2001-12-01

    The Antarctic Peninsula is an ideal region to investigate climate change at decadal to millennial timescales due to its location in one of the earth's most dynamic climate systems. We have targeted the geochemical sedimentary record of ODP Site 1098 in the Palmer Deep to investigate changes in Holocene glacial evolution and oscillations in the Circumpolar Deep Water as traced by terrigenous provenance, terrigenous accumulation, nutrient utilization, and surface and export production. More than 50 meters of laminated diatomaceous muds, oozes, and muddy diamictons were recovered from the Palmer Deep, comprising the first, high-resolution, continuous Holocene sediment record from the Antarctic continental margin. We report on a synthesis of trace and major element, stable isotope, and C/N geochemistry on samples collected at a temporal resolution ranging from ~8 to ~50 years. We analyzed Si, Al, Ti, P, Ba, biogenic opal, organic C and N, and organic 13C/12C and 15N/14N isotopic ratios every 2.5 to 10 cm downcore. A series of sequential extractions were completed on a subset of samples to better constrain the elemental distribution within the different components of the sediment. Our chronology is based on 36 AMS radiocarbon dates. Biogenic opal, Corg, and P accumulation rates all increase ~2,000 years B.P., reaching a maximum ~5,500 to 7,000 years B.P. Opal concentrations are less variable, yet indicate that biosiliceous production increased during the mid-Holocene. 13C/12C in bulk organic matter are high (with values similar to ice-edge bloom products) ~4500 to 7000 years B.P., signifying stronger diatom bloom events during the mid-Holocene. Prior to ~3000 years B.P., delta15N was lower for ~2,000 years, resulting from less complete utilization of photic zone nitrate. The Al/Ti ratio indicates a change in terrigenous composition ~3500 years B.P. indicating a change in source, weathering style, and/or intensity. All tracers of productivity and terrigenous provenance

  9. Dynamic instability of dislocation motion at high-strain-rate deformation of crystals with high concentration of point defects

    NASA Astrophysics Data System (ADS)

    Malashenko, V. V.

    2015-12-01

    The motion of an ensemble of edge dislocations has been studied under conditions of high-strainrate deformation of a crystal with a high concentration of point defects. The conditions of existence of the region of dynamic instability of dislocation motion have been found. It has been shown that the existence of the region and its boundaries is determined by the proportion of the point defect concentration and the dislocation density.

  10. Estimating Cell Concentration in Three-Dimensional Engineered Tissues using High Frequency Quantitative Ultrasound

    PubMed Central

    Mercado, Karla P.; Helguera, Marίa; Hocking, Denise C.; Dalecki, Diane

    2015-01-01

    Histology and biochemical assays are standard techniques for estimating cell concentration in engineered tissues. However, these techniques are destructive and cannot be used for longitudinal monitoring of engineered tissues during fabrication processes. The goal of this study was to develop high-frequency quantitative ultrasound techniques to nondestructively estimate cell concentration in three-dimensional (3-D) engineered tissue constructs. High-frequency ultrasound backscatter measurements were obtained from cell-embedded, 3-D agarose hydrogels. Two broadband single-element transducers (center frequencies of 30 and 38 MHz) were employed over the frequency range of 13 to 47 MHz. Agarose gels with cell concentrations ranging from 1×104 to 1×106 cells mL−1 were investigated. The integrated backscatter coefficient (IBC), a quantitative ultrasound spectral parameter, was calculated and used to estimate cell concentration. Accuracy and precision of this technique were analyzed by calculating the percent error and coefficient of variation of cell concentration estimates. The IBC increased linearly with increasing cell concentration. Axial and lateral dimensions of regions of interest that resulted in errors of less than 20% were determined. Images of cell concentration estimates were employed to visualize quantitatively regional differences in cell concentrations. This ultrasound technique provides the capability to rapidly quantify cell concentration within 3-D tissue constructs noninvasively and nondestructively. PMID:24627179

  11. [Evaluation of penicillin expandase mutants and complex substrate inhibition characteristics at high concentrations of penicillin G].

    PubMed

    Wu, Linjun; Fan, Keqiang; Ji, Junjie; Yang, Keqian

    2015-12-01

    Penicillin expandase, also known as deacetoxycephalosporin C synthase (DAOCS), is an essential enzyme involved in cephalosporin C biosynthesis. To evaluate the catalytic behaviors of penicillin expandase under high penicillin G concentration and to identify mutants suitable for industrial applications, the specific activities of wild-type DAOCS and several mutants with increased activities toward penicillin G were determined by HPLC under high penicillin G concentrations. Their specific activity profiles were compared with theoretical predictions by different catalytic dynamics models. We evaluated the specific activities of wild-type DAOCS and previous reported high-activity mutants H4, H5, H6 and H7 at concentrations ranging from 5.6 to 500 mmol/L penicillin G. The specific activities of wild-type DAOCS and mutant H4 increased as penicillin G concentration increased, but decreased when concentrations of substrate go above 200 mmol/L. Other mutants H5, H6 and H7 showed more complex behaviors under high concentration of penicillin G. Among all tested enzymes, mutant H6 showed the highest activity when concentration of penicillin G is above 100 mmol/L. Our results revealed that the substrate inhibition to wild-type DAOCS' by penicillin G is noncompetitive. Other DAOCS mutants showed more complex trends in their specific activities at high concentration of penicillin G (>100 mmol/L), indicating more complex substrate inhibition mechanism might exist. The substrate inhibition and activity of DAOCS mutants at high penicillin G concentration provide important insight to help select proper mutants for industrial application. PMID:27093832

  12. Low concentrations of isothiocyanates protect mesenchymal stem cells from oxidative injuries, while high concentrations exacerbate DNA damage.

    PubMed

    Zanichelli, Fulvia; Capasso, Stefania; Di Bernardo, Giovanni; Cipollaro, Marilena; Pagnotta, Eleonora; Cartenì, Maria; Casale, Fiorina; Iori, Renato; Giordano, Antonio; Galderisi, Umberto

    2012-09-01

    Isothiocyanates (ITCs) are molecules naturally present in many cruciferous vegetables (broccoli, black radish, daikon radish, and cauliflowers). Several studies suggest that cruciferous vegetable consumption may reduce cancer risk and slow the aging process. To investigate the effect of ITCs on cellular DNA damage, we evaluated the effects of two different ITCs [sulforaphane (SFN) and raphasatin (RPS)] on the biology of human mesenchymal stem cells (MSCs), which, in addition to their ability to differentiate into mesenchymal tissues, contribute to the homeostatic maintenance of many organs. The choice of SFN and RPS relies on two considerations: they are among the most popular cruciferous vegetables in the diet of western and eastern countries, respectively, and their bioactive properties may differ since they possess specific molecular moiety. Our investigation evidenced that MSCs incubated with low doses of SFN and RPS show reduced in vitro oxidative stress. Moreover, these cells are protected from oxidative damages induced by hydrogen peroxide, while no protection was evident following treatment with the UV ray of a double strand DNA damaging drug, such as doxorubicin. High concentrations of both ITCs induced cytotoxic effects in MSC cultures and further increased DNA damage induced by peroxides. In summary, our study suggests that ITCs, at low doses, may contribute to slowing the aging process related to oxidative DNA damage. Moreover, in cancer treatment, low doses of ITCs may be used as an adjuvant to reduce chemotherapy-induced oxidative stress, while high doses may synergize with anticancer drugs to promote cell DNA damage. PMID:22684843

  13. High efficiency concentrator modules using single and multijunction III-V solar cells

    SciTech Connect

    Kuryla, M.S.; Fraas, L.M. ); Bigger, J.E. )

    1992-12-01

    Solar cells fabricated from various III-V compounds have recently produced very high laboratory conversion efficiencies approaching 29% for single junction and 35% for multijunction structures under concentrated illumination. However, due to their relatively limited availability, few of these devices have been incorporated into actual concentrator module structures. Details are presented from two development efforts which have incorporated III-V cells into high efficiency prototype concentrator modules: (1) Varian's GaAs module operating at 1000 suns with flat fresnel lenses; and (2) Boeing's tandem GaAs/GaSb module operating at 50 suns with Entech's domed fresnel lenses.

  14. High-accuracy measurements of N2O concentration and isotopic composition of low and high concentration samples with small volume injections using Cavity Ring-Down Spectroscopy

    NASA Astrophysics Data System (ADS)

    Saad, Nabil; Palmer, Melissa; Huang, Kuan

    2015-04-01

    Nitrous oxide (N2O) gas is among the major contributors to global warming and ozone depletion in stratosphere. Quantitative estimate of N2O production in various pathways and N2O fluxes across different reservoirs is the key to understanding the role of N2O in the global change. To achieve this goal, accurate and concurrent measurement of both N2O concentration ([N2O]) and its associated isotopic ratios (δ 15Nα , δ 15{N}β & δ 18O) is desired. Recent developments in Cavity Ring-Down Spectroscopy (CRDS) have enabled high-precision measurements of [N2O] and Site-Preference-δ 15N (SP-δ 15N) and δ 18O of a continuous gas flow. However, many N2O samples are discrete with limited volume ( 2 ppm), and are not suitable for direct continuous measurements by CRDS. Here we present results of a small sample introduction and handling device, labelled as Small Sample Isotope Module (SSIM), coupled to and automatically coordinated with a Picarro isotopic N2O CRDS analyzer to handle and measure high concentration and/or small volume samples. The SSIM requires 20 ml of sample volume per analysis at STP, and transfers the sample to the CRDS for high-precision concentration and isotope ratio measurements. When the injected sample is

  15. Stable, concentrated solutions of high molecular weight polyaniline and articles therefrom

    DOEpatents

    Mattes, Benjamin R.; Wang, Hsing-Lin

    1999-11-09

    Stable, concentrated solutions of high molecular weight polyaniline. In order to process high quality fibers and other articles possessing good mechanical properties, it is known that solution concentrations of the chosen polymer should be in the range from 15-30% (w/w). Moreover, it is desirable to use the highest molecular weight consistent with the solubility properties of the polymer. However, such solutions are inherently unstable, forming gels before processing can be achieved. The present invention describes the addition gel inhibitors (GIs) to the polymer solution, thereby permitting high concentrations (between 15% and 30% (w/w)) of high molecular weight ((M.sub.w)>120,000, and (M.sub.n)>30,000) emeraldine base (EB) polyaniline to be dissolved. Secondary amines have been used for this purpose in concentrations which are small compared to those which might otherwise be used in a cosolvent role therefor. The resulting solutions are useful for generating excellent fibers, films, coatings and other objects, since the solutions are stable for significant time periods, and the GIs are present in too small concentrations to cause polymer deterioration. It is demonstrated that the GIs found to be useful do not act as cosolvents, and that gelation times of the solutions are directly proportional to the concentration of GI. In particular, there is a preferred concentration of GI, which if exceeded causes structural and electrical conductivity degradation of resulting articles. Heating of the solutions significantly improves solubility.

  16. Stable, concentrated solutions of high molecular weight polyaniline and articles therefrom

    DOEpatents

    Mattes, Benjamin R.; Wang, Hsing-Lin

    2000-01-01

    Stable, concentrated solutions of high molecular weight polyaniline. In order to process high quality fibers and other articles possessing good mechanical properties, it is known that solution concentrations of the chosen polymer should be in the range from 15-30% (w/w). Moreover, it is desirable to use the highest molecular weight consistent with the solubility properties of the polymer. However, such solutions are inherently unstable, forming gels before processing can be achieved. The present invention describes the addition gel inhibitors (GIs) to the polymer solution, thereby permitting high concentrations (>15% (w/w)) of high molecular weight ((M.sub.w)>120,000, and (M.sub.n)>30,000) emeraldine base (EB) polyaniline to be dissolved. Secondary amines have been used for this purpose in concentrations which are small compared to those which might otherwise be used in a cosolvent role therefor. The resulting solutions are useful for generating excellent fibers, films, coatings and other objects, since the solutions are stable for significant time periods, and the GIs are present in too small concentrations to cause polymer deterioration. It is demonstrated that the GIs found to be useful do not act as cosolvents, and that gelation times of the solutions are directly proportional to the concentration of GI. In particular, there is a preferred concentration of GI, which if exceeded causes structural and electrical conductivity degradation of resulting articles. Heating of the solutions significantly improves solubility.

  17. The Cauliflower Or Gene Encodes a DnaJ Cysteine-Rich Domain-Containing Protein That Mediates High Levels of β-Carotene Accumulation[W

    PubMed Central

    Lu, Shan; Van Eck, Joyce; Zhou, Xiangjun; Lopez, Alex B.; O'Halloran, Diana M.; Cosman, Kelly M.; Conlin, Brian J.; Paolillo, Dominick J.; Garvin, David F.; Vrebalov, Julia; Kochian, Leon V.; Küpper, Hendrik; Earle, Elizabeth D.; Cao, Jun; Li, Li

    2006-01-01

    Despite recent progress in our understanding of carotenogenesis in plants, the mechanisms that govern overall carotenoid accumulation remain largely unknown. The Orange (Or) gene mutation in cauliflower (Brassica oleracea var botrytis) confers the accumulation of high levels of β-carotene in various tissues normally devoid of carotenoids. Using positional cloning, we isolated the gene representing Or and verified it by functional complementation in wild-type cauliflower. Or encodes a plastid-associated protein containing a DnaJ Cys-rich domain. The Or gene mutation is due to the insertion of a long terminal repeat retrotransposon in the Or allele. Or appears to be plant specific and is highly conserved among divergent plant species. Analyses of the gene, the gene product, and the cytological effects of the Or transgene suggest that the functional role of Or is associated with a cellular process that triggers the differentiation of proplastids or other noncolored plastids into chromoplasts for carotenoid accumulation. Moreover, we demonstrate that Or can be used as a novel genetic tool to induce carotenoid accumulation in a major staple food crop. We show here that controlling the formation of chromoplasts is an important mechanism by which carotenoid accumulation is regulated in plants. PMID:17172359

  18. The accumulation of glutamate is necessary for optimal growth of Salmonella typhimurium in media of high osmolality but not induction of the proU operon.

    PubMed

    Csonka, L N; Ikeda, T P; Fletcher, S A; Kustu, S

    1994-10-01

    Synthesis of glutamate can be limited in bacterial strains carrying mutations to loss of function of glutamate synthase (2-oxoglutarate:glutamine aminotransferase) by using low concentrations of NH4+ in the growth medium. By using such gltB/D mutant strains of Salmonella typhimurium, we demonstrated that: (i) a large glutamate pool, previously observed to correlate with growth at high external osmolality, is actually required for optimal growth under these conditions; (ii) the osmoprotectant glycine betaine (N,N,N-trimethylglycine) apparently cannot substitute for glutamate; and (iii) accumulation of glutamate is not necessary for high levels of induction of the proU operon in vivo. Expression of the proU operon, which encodes a transport system for the osmoprotectants proline and glycine betaine, is induced > 100-fold in the wild-type strain under conditions of high external osmolality. Ramirez et al. (R. M. Ramirez, W. S. Prince, E. Bremer, and M. Villarejo, Proc. Natl. Acad. Sci. USA 86:1153-1157, 1989) observed and we confirmed that in vitro expression of the lacZ gene from the wild-type proU promoter is stimulated by 0.2 to 0.3 M K glutamate. However, we observed a very similar stimulation for lacZ expressed from the lacUV5 promoter and from the proU promoter when an important negative regulatory element downstream of this promoter (the silencer) was deleted. Since the lacUV5 promoter is not osmotically regulated in vivo and osmotic regulation of the proU promoter is largely lost as a result of deletion of the silencer, we conclude that stimulation of proU expression by K glutamate in vitro is not a specific osmoregulatory response but probably a manifestation of the optimization of in vitro transcription-translation at high concentrations of this solute. Our in vitro and in vivo results demonstrate that glutamate is not an obligatory component of the transcriptional regulation of the proU operon. PMID:7929004

  19. Ginger Essential Oil Ameliorates Hepatic Injury and Lipid Accumulation in High Fat Diet-Induced Nonalcoholic Fatty Liver Disease.

    PubMed

    Lai, Yi-Syuan; Lee, Wan-Ching; Lin, Yu-En; Ho, Chi-Tang; Lu, Kuan-Hung; Lin, Shih-Hang; Panyod, Suraphan; Chu, Yung-Lin; Sheen, Lee-Yan

    2016-03-16

    The objective of this study was to investigate the hepatoprotective efficacy and mechanism of action of ginger essential oil (GEO) against the development of nonalcoholic fatty liver disease (NAFLD). Mice were maintained on either a control diet or high-fat diet (HFD) supplemented with GEO (12.5, 62.5, and 125 mg/kg) or citral (2.5 and 25 mg/kg) for 12 weeks. We demonstrated that GEO and its major component (citral) lowered HFD-induced obesity in a dose-dependent manner, accompanied by anti-hyperlipidemic effects by reducing serum free fatty acid, triglyceride, and total cholesterol levels. Moreover, liver histological results showed that administration of 62.5 and 125 mg/kg GEO and 25 mg/kg citral significantly reduced hepatic lipid accumulation. Further assessment by Western blotting and investigation of the lipid metabolism revealed that hepatic protein expression of sterol regulatory element-binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), and cytochrome P450 2E1 (CYP2E1) were down-regulated by GEO and citral, indicating that GEO and citral suppressed HFD-stimulated lipid biosynthesis and oxidative stress. Furthermore, GEO and citral effectively enhanced the antioxidant capacities and reduced inflammatory response in mouse liver, which exerted protective effects against steatohepatitis. Collectively, GEO and citral exhibited potent hepatoprotective effects against NAFLD induced by HFD in obese mice. Thus, GEO might be an effective dietary supplement to ameliorate NAFLD-related metabolic diseases, and citral could play a vital role in its management. PMID:26900108

  20. Inhibitory effect of high NH4(+)-N concentration on anaerobic biotreatment of fresh leachate from a municipal solid waste incineration plant.

    PubMed

    Liu, Zhao; Dang, Yan; Li, Caihua; Sun, Dezhi

    2015-09-01

    Fresh leachate from municipal solid waste (MSW) incineration plants generally contains extremely high NH4(+)-N concentration which could inhibit the bioactivity of microorganisms. The inhibitory effect of high NH4(+)-N concentration on anaerobic biotreatment of fresh leachate from a MSW incineration plant in China has been investigated in this study. The inhibition processes was studied by both static tests and a laboratory-scale expanded granular sludge bed (EGSB) reactor. The specific methanogenic activity (SMA) of the microorganisms in anaerobic granular sludge was inhibited with the NH4(+)-N concentration increasing to 1000mg/L in static tests. As well the chemical oxygen demand (COD) removal efficiency and the methane yield decreased in the EGSB reactor, while the volatile fatty acids (VFAs) accumulated and extracellular polymeric substances (EPS) of the anaerobic granular sludge increased with NH4(+)-N concentration rising to 1000mg/L, without any rebounding during 30days of operation. Decreasing NH4(+)-N concentration to 500mg/L in influent, the COD removal efficiency recovered to about 85% after 26days. 1000mg/L of NH4(+)-N in leachate was suggested to be the inhibition threshold in EGSB reactor. High-throughput sequencing results showed little changes in microbial communities of the sludge for a high NH4(+)-N concentration, indicating that the survival of most microorganisms was not affected under such a condition. It inhibited the bioactivity of the microorganisms, resulting in decrease of the COD removal efficiency. PMID:26139135

  1. The influence of climate change on recent peat accumulation patterns of Distichia muscoides cushion bogs in the high-elevation tropical Andes of Colombia

    NASA Astrophysics Data System (ADS)

    Benavides, Juan C.; Vitt, Dale H.; Wieder, R. Kelman

    2013-12-01

    Extensive cushions of Distichia muscoides found at high elevations in the Andes form deep deposits of peat and function as peatland. The location of Distichia peatlands at the highest elevations makes them susceptible to the effects of global change including global warming. Accumulation rates of organic matter are the key function of peatland ecosystems and are highly susceptible to changes in climate. This study used 210Pb chronologies to infer the recent dynamics of three Distichia muscoides peatlands located above 4000 m in elevation. Chronological markers from dated volcanic eruptions were correlated to the 210Pb chronologies of Distichia peat and validated the 210Pb chronologies. Changes in 210Pb activity with depth indicated rapid accumulation in recent times. Organic matter had a mean accumulation rate of 1400 g m-2 yr-1 during the past 10 years, with values well above the observed regional accumulation rate of 300-400 g m-2 yr-1. The same pattern was observed in peat accretion rates, with growth rates of 1-2 cm per year during the last 10 years. Cushion plants engineer their own environment, allowing the system to be less susceptible to direct changes in climate. However, the high rates of peat accretion in recent times may be originated from increasing temperatures and excess water from nearby glacier melt. However, glaciers are predicted to disappear during the next 20 years in the northern Andes, reducing water inputs in tropical high-elevation ecosystems.

  2. Quantification of Maize Fine Streak Virus Genomic and Positive-sense RNAs in Infected Maize Reveals High Level Accumulation of ORF 3 and 4 MFSV Transcripts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantification of Maize fine streak virus genomic and positive-sense RNAs in infected maize reveals high level accumulation of ORF 3 and 4 MFSV transcripts. We improved methods to analyze RNA produced by Maize fine streak virus (MVSF) within infected maize tissue using real-time RT-qPCR. We designe...

  3. Accumulation of formamide in hydrothermal pores to form prebiotic nucleobases.

    PubMed

    Niether, Doreen; Afanasenkau, Dzmitry; Dhont, Jan K G; Wiegand, Simone

    2016-04-19

    Formamide is one of the important compounds from which prebiotic molecules can be synthesized, provided that its concentration is sufficiently high. For nucleotides and short DNA strands, it has been shown that a high degree of accumulation in hydrothermal pores occurs, so that temperature gradients might play a role in the origin of life [Baaske P, et al. (2007)Proc Natl Acad Sci USA104(22):9346-9351]. We show that the same combination of thermophoresis and convection in hydrothermal pores leads to accumulation of formamide up to concentrations where nucleobases are formed. The thermophoretic properties of aqueous formamide solutions are studied by means of Infrared Thermal Diffusion Forced Rayleigh Scattering. These data are used in numerical finite element calculations in hydrothermal pores for various initial concentrations, ambient temperatures, and pore sizes. The high degree of formamide accumulation is due to an unusual temperature and concentration dependence of the thermophoretic behavior of formamide. The accumulation fold in part of the pores increases strongly with increasing aspect ratio of the pores, and saturates to highly concentrated aqueous formamide solutions of ∼85 wt% at large aspect ratios. Time-dependent studies show that these high concentrations are reached after 45-90 d, starting with an initial formamide weight fraction of[Formula: see text]wt % that is typical for concentrations in shallow lakes on early Earth. PMID:27044100

  4. Phenylacetylene reversibly inhibits the phenol hydroxylase of Pseudomonas sp. CF600 at high concentrations but is oxidized at lower concentrations.

    PubMed

    Kagle, Jeanne; Hay, Anthony G

    2006-09-01

    Alkynes are mechanism-based inhibitors of several bacterial monooxygenases, including the soluble methane monooxygenase (sMMO) of Methylococcus capsulatus and the toluene o-monooxygenase (TOM) of Burkholderia cepacia G4. In this paper, we investigated the inhibition of the phenol hydroxylase of Pseudomonas sp. CF600 by the alkyne phenylacetylene. Growth of CF600 on phenol and phenol hydroxylase activity were inhibited by phenylacetylene concentrations greater than 1.0 mM. Unlike other alkynes, which irreversibly inhibit a number of monooxygenases, inhibition of phenol hydroxylase by phenylacetylene was reversible, as demonstrated by the ability of washed cells to regain phenol hydroxylase activity. Additionally, phenylacetylene was metabolized by phenol-grown cells, yielding a yellow meta-ring fission product which absorbed light maximally at 412 nm. Phenol-grown CF600 transformed phenylacetylene to hydroxyphenylacetylene and 2-hydroxy-6-oxo-octa-2,4-dien-7-ynoic acid as detected by gas chromatography--mass spectroscopy and high-performance liquid chromatography (HPLC), respectively, while neither a derivative of CF600 with a non-functional phenol hydroxylase nor wild-type CF600 grown on acetate transformed phenylacetylene. These results demonstrate that the phenol hydroxylase of CF600 has broader substrate specificity than previously reported. They also suggest that phenylacetylene acts as a competitive inhibitor rather than as a mechanism-based inhibitor of this phenol hydroxylase. PMID:16485115

  5. Spatiotemporal models for predicting high pollen concentration level of Corylus, Alnus, and Betula

    NASA Astrophysics Data System (ADS)

    Nowosad, Jakub

    2016-06-01

    Corylus, Alnus, and Betula trees are among the most important sources of allergic pollen in the temperate zone of the Northern Hemisphere and have a large impact on the quality of life and productivity of allergy sufferers. Therefore, it is important to predict high pollen concentrations, both in time and space. The aim of this study was to create and evaluate spatiotemporal models for predicting high Corylus, Alnus, and Betula pollen concentration levels, based on gridded meteorological data. Aerobiological monitoring was carried out in 11 cities in Poland and gathered, depending on the site, between 2 and 16 years of measurements. According to the first allergy symptoms during exposure, a high pollen count level was established for each taxon. An optimizing probability threshold technique was used for mitigation of the problem of imbalance in the pollen concentration levels. For each taxon, the model was built using a random forest method. The study revealed the possibility of moderately reliable prediction of Corylus and highly reliable prediction of Alnus and Betula high pollen concentration levels, using preprocessed gridded meteorological data. Cumulative growing degree days and potential evaporation proved to be two of the most important predictor variables in the models. The final models predicted not only for single locations but also for continuous areas. Furthermore, the proposed modeling framework could be used to predict high pollen concentrations of Corylus, Alnus, Betula, and other taxa, and in other countries.

  6. Spatiotemporal models for predicting high pollen concentration level of Corylus, Alnus, and Betula.

    PubMed

    Nowosad, Jakub

    2016-06-01

    Corylus, Alnus, and Betula trees are among the most important sources of allergic pollen in the temperate zone of the Northern Hemisphere and have a large impact on the quality of life and productivity of allergy sufferers. Therefore, it is important to predict high pollen concentrations, both in time and space. The aim of this study was to create and evaluate spatiotemporal models for predicting high Corylus, Alnus, and Betula pollen concentration levels, based on gridded meteorological data. Aerobiological monitoring was carried out in 11 cities in Poland and gathered, depending on the site, between 2 and 16 years of measurements. According to the first allergy symptoms during exposure, a high pollen count level was established for each taxon. An optimizing probability threshold technique was used for mitigation of the problem of imbalance in the pollen concentration levels. For each taxon, the model was built using a random forest method. The study revealed the possibility of moderately reliable prediction of Corylus and highly reliable prediction of Alnus and Betula high pollen concentration levels, using preprocessed gridded meteorological data. Cumulative growing degree days and potential evaporation proved to be two of the most important predictor variables in the models. The final models predicted not only for single locations but also for continuous areas. Furthermore, the proposed modeling framework could be used to predict high pollen concentrations of Corylus, Alnus, Betula, and other taxa, and in other countries. PMID:26487352

  7. Evidence of Cholesterol Accumulated in High Curvature Regions: Implication to the Curvature Elastic Energy for Lipid Mixtures

    PubMed Central

    Wang, Wangchen; Yang, Lin; Huang, Huey W.

    2007-01-01

    Recent experiments suggested that cholesterol and other lipid components of high negative spontaneous curvature facilitate membrane fusion. This is taken as evidence supporting the stalk-pore model of membrane fusion in which the lipid bilayers go through intermediate structures of high curvature. How do the high-curvature lipid components lower the free energy of the curved structure? Do the high-curvature lipid components modify the average spontaneous curvature of the relevant monolayer, thereby facilitate its bending, or do the lipid components redistribute in the curved structure so as to lower the free energy? This question is fundamental to the curvature elastic energy for lipid mixtures. Here we investigate the lipid distribution in a monolayer of a binary lipid mixture before and after bending, or more precisely in the lamellar, hexagonal, and distorted hexagonal phases. The lipid mixture is composed of 2:1 ratio of brominated di18:0PC and cholesterol. Using a newly developed procedure for the multiwavelength anomalous diffraction method, we are able to isolate the bromine distribution and reconstruct the electron density distribution of the lipid mixture in the three phases. We found that the lipid distribution is homogenous and uniform in the lamellar and hexagonal phases. But in the distorted hexagonal phase, the lipid monolayer has nonuniform curvature, and cholesterol almost entirely concentrates in the high curvature region. This finding demonstrates that the association energies between lipid molecules vary with the curvature of membrane. Thus, lipid components in a mixture may redistribute under conditions of nonuniform curvature, such as in the stalk structure. In such cases, the spontaneous curvature depends on the local lipid composition and the free energy minimum is determined by lipid distribution as well as curvature. PMID:17259270

  8. Investigating high-concentration monoclonal antibody powder suspension in nonaqueous suspension vehicles for subcutaneous injection.

    PubMed

    Bowen, Mayumi; Armstrong, Nick; Maa, Yuh-Fun

    2012-12-01

    Developing high-concentration monoclonal antibody (mAb) liquid formulations for subcutaneous (s.c.) administration is challenging because increased viscosity makes injection difficult. To overcome this obstacle, we investigated a nonaqueous powder suspension approach. Three IgG1 mAbs were spray dried and suspended at different concentrations in Miglyol® 840, benzyl benzoate, or ethyl lactate. Suspensions were characterized for viscosity, particle size, and syringeability; physical stability was visually inspected. Suspensions generally outperformed liquid solutions for injectability despite higher viscosity at the same mAb concentrations. Powder formulations and properties had little effect on viscosity or injectability. Ethyl lactate suspensions had lowest viscosity (<20 cP) and lowest syringe injection glide force (<15 N) at mAb concentrations as high as 333 mg/mL (500 mg powder/mL). Inverse gas chromatography analysis indicated that the vehicle was the most important factor impacting suspension performance. Ethyl lactate rendered greater heat of sorption (suggesting strong particle-suspension vehicle interaction may reduce particle-particle self-association, leading to low suspension viscosity and glide force) but lacked the physical suspension stability exhibited by the other vehicles. Specific mixtures of ethyl lactate and Miglyol® 840 improved overall performance in high mAb concentration suspensions. This study demonstrated the viability of high mAb concentration (>300 mg/mL) in suspension formulations for s.c. administration. PMID:23001898

  9. Dependence of Ablative Rayleigh—Taylor Instability on High-Z Dopant Concentration

    NASA Astrophysics Data System (ADS)

    Shiroto, Takashi; Ohnishi, Naofumi; Sunahara, Atsushi; Fujioka, Shinsuke

    2016-03-01

    We conducted two-dimensional simulations of inertial confinement fusion targets to evaluate effects of high-Z doping on implosion hydrodynamics. It was found that an ablation structure drastically changes with concentration of dopant material. We also confirmed that even a lightly-doped target can suppress Rayleigh-Taylor instability on short wavelength, while a long-wavelength perturbation is difficult to be suppressed with any dopant concentration. The high-Z doping is thus only effective for a spherical implosion with high-mode perturbations.

  10. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  11. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  12. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  13. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  14. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  15. Efficient photoinduced charge accumulation in reduced graphene oxide coupled with titania nanosheets to show highly enhanced and persistent conductance.

    PubMed

    Cai, Xingke; Sakai, Nobuyuki; Ozawa, Tadashi C; Funatsu, Asami; Ma, Renzhi; Ebina, Yasuo; Sasaki, Takayoshi

    2015-06-01

    Tuning of the electrical properties of graphene via photoexcitation of a heteroassembled material has started to attract attention for electronic and optoelectronic applications. Actually photoinduced carrier doping from the hexagonal boron nitride (h-BN) substrate greatly modulated the transport property of the top layer graphene, showing promising potential for this approach. However, for practical applications, the large scale production of this two-dimensional heterostructure is needed. Here, a superlattice film constructed from reduced graphene oxide (rGO) and photoactive titania nanosheets (Ti0.87O2(0.52-)) was employed as a channel to construct a field effect transistor (FET) device, and its UV light response on the electrical transport property was examined. The UV light illumination induced significant improvement of the electrical conductance by ∼7 times on the basis of simultaneous enhancements of the electron carrier concentration and its mobility in rGO. Furthermore, the polarity of the FET response changed from ambipolar to n-type unipolar. Such modulated properties persisted in vacuum even after the UV light was turned off. These interesting behaviors may be explained in terms of photomodulation effects from Ti0.87O2(0.52-) nanosheets. The photoexcited electrons in Ti0.87O2(0.52-) are injected into rGO to increase the electron carrier concentration as high as 7.6×10(13) cm(-2). On the other hand, the holes are likely trapped in the Ti0.87O2(0.52-) nanosheets. These photocarriers undergo reduction and oxidation of oxygen and water molecules adsorbed in the film, respectively, which act as carrier scattering centers, contributing to the enhancement of the carrier mobility. Since the film likely contains more water molecules than oxygen, upon extinction of UV light, a major portion of electrons (∼80% of the concentration at the UV off) survives in rGO, showing the highly enhanced conductance for days. This surpassing photomodulated FET response and

  16. Capillary electrophoresis of proteins in buffers containing high concentrations of zwitterionic salts.

    PubMed

    Bushey, M M; Jorgenson, J W

    1989-10-20

    A method for improving protein separations in capillary zone electrophoresis utilizing high concentrations of zwitterionic buffer additives was examined. Lysozyme and alpha-chymotrypsinogen A were used as test proteins in untreated fused-silica capillaries in buffers of pH ca. 7.0 and 9.0 The zwitterion-containing buffers were compared with buffers containing high ionic salt concentrations and a buffer containing a combination of high ionic salt and high zwitterion concentrations. Over 100,000 theoretical plates were obtained in less than 30 min. for both test proteins in a pH 7 buffer containing both trimethylglycine and potassium sulfate. The advantages and disadvantages of this technique compared with those of other methods used to prevent protein adsorption are discussed. PMID:2592485

  17. The design and research of distributed cooling type high concentrated photovoltaic module

    NASA Astrophysics Data System (ADS)

    Dai, Mingchong; Yao, Shun; Chen, Bingzhen; Yang, Guanghui; Guo, Limin; Peng, Na; Shen, Du; Bao, Wei; Yang, Cuibai; Zhang, Yang; Wang, Zhiyong

    2015-10-01

    At present, the conversion efficiency of high concentrated photovoltaic modules is about 30%, most of the solar energy is converted into heat, which will result in solar cell temperature rise and subsequent module efficiency decrease. For existing module with large solar cell, the heat source is concentrated and additional cooling fins must be used, resulting in high system complexity and cost rise. In order to lower the cost of photovoltaic, we developed distributed cooling type module with simple structure. This paper depicts a distributed cooling design for high concentrated photovoltaic module, as well as the thermal simulation of this design with analysis software. Module prototype was also made to test the actual effect. The final outdoor results showed high consistency with the simulation results. The chip temperature can be lower than 45° and the module outdoor working efficiency is higher than 26% and lower temperature provide a guarantee of long-term reliability to module packaging material.

  18. A High Frequency Response Relaxed Eddy Accumulation Flux Measurement System for Sampling Short-Lived Biogenic Volatile Organic Compounds

    EPA Science Inventory

    A second-generation relaxed eddy accumulation system was built and tested with the capability to measure vertical biogenic volatile organic compound (VOC) fluxes at levels as low as 10 µg C m−2 hr−1. The system features a continuous, integrated gas-phase ozo...

  19. Understanding sugar yield loss and enzyme inhibition due to oligosaccharides accumulation during high solids-loading enzymatic hydrolisis.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During enzymatic hydrolysis of biomass, polysaccharides are cleaved by glycosyl hydrolases to soluble oligosaccharides and further hydrolyzed by ß-glucosidase, ß-xylosidase and other enzymes to monomeric sugars. However, not all oligosaccharides can be fully hydrolyzed and they may accumulate to 18-...

  20. Prodigious Effects of Concentration Intensification on Nanoparticle Synthesis: A High-Quality, Scalable Approach.

    PubMed

    Williamson, Curtis B; Nevers, Douglas R; Hanrath, Tobias; Robinson, Richard D

    2015-12-23

    Realizing the promise of nanoparticle-based technologies demands more efficient, robust synthesis methods (i.e., process intensification) that consistently produce large quantities of high-quality nanoparticles (NPs). We explored NP synthesis via the heat-up method in a regime of previously unexplored high concentrations near the solubility limit of the precursors. We discovered that in this highly concentrated and viscous regime the NP synthesis parameters are less sensitive to experimental variability and thereby provide a robust, scalable, and size-focusing NP synthesis. Specifically, we synthesize high-quality metal sulfide NPs (<7% relative standard deviation for Cu2-xS and CdS), and demonstrate a 10-1000-fold increase in Cu2-xS NP production (>200 g) relative to the current field of large-scale (0.1-5 g yields) and laboratory-scale (<0.1 g) efforts. Compared to conventional synthesis methods (hot injection with dilute precursor concentration) characterized by rapid growth and low yield, our highly concentrated NP system supplies remarkably controlled growth rates and a 10-fold increase in NP volumetric production capacity (86 g/L). The controlled growth, high yield, and robust nature of highly concentrated solutions can facilitate large-scale nanomanufacturing of NPs by relaxing the synthesis requirements to achieve monodisperse products. Mechanistically, our investigation of the thermal and rheological properties and growth rates reveals that this high concentration regime has reduced mass diffusion (a 5-fold increase in solution viscosity), is stable to thermal perturbations (∼64% increase in heat capacity), and is resistant to Ostwald ripening. PMID:26592380

  1. Evaluation of the Chemcatcher and DGT passive samplers for monitoring metals with highly fluctuating water concentrations.

    PubMed

    Allan, Ian J; Knutsson, Jesper; Guigues, Nathalie; Mills, Graham A; Fouillac, Anne-Marie; Greenwood, Richard

    2007-07-01

    Passive sampling devices accumulate chemicals continuously from water and can provide time weighted average (TWA) concentrations of pollutants over the exposure period. Hence, they offer a number of advantages over other conventional monitoring techniques such as spot or grab sampling. The diffusive gradient in thin film (DGT) and the Chemcatcher passive samplers can be used to provide TWA concentrations of labile metals, but the approaches to their calibration differ. DGT uses diffusion coefficients of metals in the hydrogel layer, whereas Chemcatcher uses metal specific uptake rates, with both sets of values obtained under controlled laboratory conditions with constant aqueous metal concentrations. However, little is known of how such samplers respond to fluctuating concentrations. We evaluated the responsiveness of these two passive sampling devices to rapidly changing concentrations of Cd, Cu, Ni, Pb and Zn in natural freshwater, over a relatively short deployment time. Maximum metal concentrations in water were varied between 70 and 140 microg L(-1). Experiments were carried out in a tank with a rotating carousel system and filled with Meuse river water, allowing a degree of control over experimental conditions while using natural river water. Fluctuating concentrations were obtained by stepwise addition of standard solutions of the metals. The reliability and accuracy of the TWA concentrations measured by the samplers were assessed by comparison with concentrations of the metals in spot samples of water taken regularly over the deployment period. The spot samples of water were either unfiltered (total), filtered (0.45 microm) or ultrafiltered (5 kDa). Predictive speciation modelling using the visual MINTEQ programme was also undertaken. There was reasonable agreement between the TWA concentrations of Cd and Ni obtained with Chemcatcher and DGT and the total Cd and Ni concentrations measured in repeated unfiltered spot samples. For elements (i.e. Cu, Pb, Zn

  2. Geochemistry Model Validation Report: External Accumulation Model

    SciTech Connect

    K. Zarrabi

    2001-09-27

    The purpose of this Analysis and Modeling Report (AMR) is to validate the External Accumulation Model that predicts accumulation of fissile materials in fractures and lithophysae in the rock beneath a degrading waste package (WP) in the potential monitored geologic repository at Yucca Mountain. (Lithophysae are voids in the rock having concentric shells of finely crystalline alkali feldspar, quartz, and other materials that were formed due to entrapped gas that later escaped, DOE 1998, p. A-25.) The intended use of this model is to estimate the quantities of external accumulation of fissile material for use in external criticality risk assessments for different types of degrading WPs: U.S. Department of Energy (DOE) Spent Nuclear Fuel (SNF) codisposed with High Level Waste (HLW) glass, commercial SNF, and Immobilized Plutonium Ceramic (Pu-ceramic) codisposed with HLW glass. The scope of the model validation is to (1) describe the model and the parameters used to develop the model, (2) provide rationale for selection of the parameters by comparisons with measured values, and (3) demonstrate that the parameters chosen are the most conservative selection for external criticality risk calculations. To demonstrate the applicability of the model, a Pu-ceramic WP is used as an example. The model begins with a source term from separately documented EQ6 calculations; where the source term is defined as the composition versus time of the water flowing out of a breached waste package (WP). Next, PHREEQC, is used to simulate the transport and interaction of the source term with the resident water and fractured tuff below the repository. In these simulations the primary mechanism for accumulation is mixing of the high pH, actinide-laden source term with resident water; thus lowering the pH values sufficiently for fissile minerals to become insoluble and precipitate. In the final section of the model, the outputs from PHREEQC, are processed to produce mass of accumulation

  3. NMR high-resolution magic angle spinning rotor design for quantification of metabolic concentrations

    NASA Astrophysics Data System (ADS)

    Holly, R.; Damyanovich, A.; Peemoeller, H.

    2006-05-01

    A new high-resolution magic angle spinning nuclear magnetic resonance technique is presented to obtain absolute metabolite concentrations of solutions. The magnetic resonance spectrum of the sample under investigation and an internal reference are acquired simultaneously, ensuring both spectra are obtained under the same experimental conditions. The robustness of the technique is demonstrated using a solution of creatine, and it is shown that the technique can obtain solution concentrations to within 7% or better.

  4. Prescriptions of dialysate potassium concentration during short daily or long nocturnal (high dose) hemodialysis.

    PubMed

    Leypoldt, John K; Agar, Baris U; Bernardo, Angelito A; Culleton, Bruce F

    2016-04-01

    The prescription of dialysate potassium concentration during short daily and long nocturnal (high dose) hemodialysis (HD) is challenging due to limited clinical experience with such modalities. The aim here is to propose a quantitative approach for prescribing dialysate potassium concentrations during high-dose HD. Potassium kinetic parameters based on a pseudo one-compartment model from 547 patients participating in the HEMO Study were used for prediction purposes in this study. Patients were categorized based on the prescribed dialysate potassium concentration during thrice weekly HD as 1K (mean of 1.02 mEq/L, N = 60), 2K (2.01 mEq/L, N = 437), or 3K (3.01 mEq/L, N = 50). Dialysate potassium concentrations were then predicted for each patient during short daily and long nocturnal HD based on a pseudo one-compartment model to maintain the identical weekly dialytic potassium removal and predialysis serum potassium concentration as during thrice weekly HD. Predicted prescribed dialysate potassium concentrations for short daily HD were 0.18-0.45 mEq/L higher than during thrice weekly HD but were approximately 4 (3.72-4.26) mEq/L for all patients during long nocturnal HD. The intradialytic decrease in serum potassium concentration was predicted to be reduced by more than one-half during short daily HD and by approximately three-quarters during long nocturnal HD of that during thrice weekly HD. Prescribed dialysate potassium concentration during high-dose HD modalities can be quantitatively predicted using a pseudo one-compartment kinetic model. High-dose HD modalities may improve clinical outcomes by reducing intradialytic decreases in serum potassium. PMID:26179136

  5. High frequency measurement of nitrate concentration in the Lower Mississippi River, USA

    NASA Astrophysics Data System (ADS)

    Duan, Shuiwang; Powell, Rodney T.; Bianchi, Thomas S.

    2014-11-01

    Nutrient concentrations in the Mississippi River have increased dramatically since the 1950s, and high frequency measurements on nitrate concentration are required for accurate load estimations and examinations on nitrate transport and transformation processes. This three year record of high temporal resolution (every 2-3 h) data clearly illustrates the importance of high frequency sampling in improving load estimates and resolving variations in nitrate concentration with river flow and tributary inputs. Our results showed large short-term (days to weeks) variations in nitrate concentration but with no diurnal patterns. A repeatable and pronounced seasonal pattern of nitrate concentration was observed, and showed gradual increases from the lowest values in September (during base-flow), to the highest in June - which was followed by a rapid decrease. This seasonal pattern was only moderately linked with water discharge, and more controlled by nitrogen transformation/export from watershed as well as mixing patterns of the two primary tributaries (the upper Mississippi and the Ohio Rivers), which have distinctly different nitrate concentrations and flow patterns. Based on continuous in situ flow measurements, we estimated 554-886 × 106 kg of nitrate-N was exported from the Mississippi River system during years 2004-2006, which was <9% and <16% lower than U.S. Geological Survey's (USGS) estimates using their LOADEST or composite methods, respectively. USGS methods generally overestimated nitrate loads during rising stages and underestimated the loads during falling stages. While changes in nitrate concentrations in large rivers are generally not as responsive to alterations in diurnal inputs and/or watershed hydrology as small rivers, high-frequency water quality sampling would help in monitoring short-term (days to weeks) variations in nutrient concentration patterns and thus improve the accuracy of nutrient flux estimates.

  6. Photorespiration and carbon concentrating mechanisms: two adaptations to high O2, low CO2 conditions.

    PubMed

    Moroney, James V; Jungnick, Nadine; Dimario, Robert J; Longstreth, David J

    2013-11-01

    This review presents an overview of the two ways that cyanobacteria, algae, and plants have adapted to high O2 and low CO2 concentrations in the environment. First, the process of photorespiration enables photosynthetic organisms to recycle phosphoglycolate formed by the oxygenase reaction catalyzed by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Second, there are a number of carbon concentrating mechanisms that increase the CO2 concentration around Rubisco which increases the carboxylase reaction enhancing CO2 fixation. This review also presents possibilities for the beneficial modification of these processes with the goal of improving future crop yields. PMID:23771683

  7. High Concentrating GaAs Cell Operation Using Optical Waveguide Solar Energy System

    NASA Technical Reports Server (NTRS)

    Nakamura, T.; Case, J. A.; Timmons, M. L.

    2004-01-01

    This paper discusses the result of the concentrating photovoltaic (CPV) cell experiments conducted with the Optical Waveguide (OW) Solar Energy System. The high concentration GaAs cells developed by Research Triangle Institute (RTI) were combined with the OW system in a "fiber-on-cell" configuration. The sell performance was tested up to the solar concentration of 327. Detailed V-I characteristics, power density and efficiency data were collected. It was shown that the CPV cells combined with the OW solar energy system will be an effective electric power generation device.

  8. Three Patients Needing High Doses of Valproic Acid to Get Therapeutic Concentrations

    PubMed Central

    Jackson, James; McCollum, Betsy; Ognibene, Judy; Diaz, Francisco J.; de Leon, Jose

    2015-01-01

    Valproic acid (VPA) can autoinduce its own metabolism. Cases requiring VPA doses >4000 mg/day to obtain therapeutic plasma concentrations, such as these 3 cases, have never been published. Case 1 received VPA for seizures and schizophrenia and had >50 VPA concentrations in 4 years. A high dose of 5,250 mg/day of VPA concentrate was prescribed for years but this dose led to an intoxication when switched to the enterocoated divalproex sodium formulation, requiring a normal dose of 2000 mg/day. VPA metabolic capacity was significantly higher (t = −9.6; df = 6.3, p < 0.001) during the VPA concentrate therapy, possibly due to autoinduction in that formulation. Case 2 had VPA for schizoaffective psychosis with 10 VPA concentrations during an 8-week admission. To maintain a VPA level ≥50 μg/mL, VPA doses increased from 1500 to 4000 mg/day. Case 3 had tuberous sclerosis and epilepsy and was followed up for >4 years with 137 VPA concentrations. To maintain VPA concentrations ≥50 μg/mL, VPA doses increased from 3,375 to 10,500 mg/day. In Cases 2 and 3, the duration of admission and the VPA dose were strongly correlated (r around 0.90; p < 0.001) with almost no change after controlling for VPA concentrations, indicating progressive autoinduction that increased with time. PMID:26000191

  9. High Voltage Solar Concentrator Experiment with Implications for Future Space Missions

    NASA Technical Reports Server (NTRS)

    Mehdi, Ishaque S.; George, Patrick J.; O'Neill, Mark; Matson, Robert; Brockschmidt, Arthur

    2004-01-01

    This paper describes the design, development, fabrication, and test of a high performance, high voltage solar concentrator array. This assembly is believed to be the first ever terrestrial triple-junction-cell solar array rated at over 1 kW. The concentrator provides over 200 W/square meter power output at a nominal 600 Vdc while operating under terrestrial sunlight. Space-quality materials and fabrication techniques were used for the array, and the 3005 meter elevation installation below the Tropic of Cancer allowed testing as close as possible to space deployment without an actual launch. The array includes two concentrator modules, each with a 3 square meter aperture area. Each concentrator module uses a linear Fresnel lens to focus sunlight onto a photovoltaic receiver that uses 240 series-connected triple-junction solar cells. Operation of the two receivers in series can provide 1200 Vdc which would be adequate for the 'direct drive' of some ion engines or microwave transmitters in space. Lens aperture width is 84 cm and the cell active width is 3.2 cm, corresponding to a geometric concentration ratio of 26X. The evaluation includes the concentrator modules, the solar cells, and the materials and techniques used to attach the solar cells to the receiver heat sink. For terrestrial applications, a finned aluminum extrusion was used for the heat sink for the solar cells, maintaining a low cell temperature so that solar cell efficiency remains high.

  10. High concentrations of myeloperoxidase in the equine uterus as an indicator of endometritis.

    PubMed

    Parrilla-Hernandez, Sonia; Ponthier, Jérôme; Franck, Thierry Y; Serteyn, Didier D; Deleuze, Stéfan C

    2014-04-15

    Intraluminal fluid and excessive abnormal hyperedema are regularly used for the diagnosis of endometritis in the mare, which is routinely confirmed by the presence of neutrophils on endometrial smears. Studies show a relation between neutrophils and myeloperoxidase (MPO), an enzyme contained in and released by neutrophils during degranulation or after cell lysis. This enzyme has been found in many fluids and tissues, and associated with different inflammatory pathologies in the horse. The aims of this study were to assess the presence and concentration of MPO in the equine uterus, and to investigate its relation with neutrophils, and other clinical signs of endometritis. Mares (n = 51) were evaluated for the presence of intraluminal fluid and excessive endometrial edema before breeding, and a small volume lavage and cytology samples were obtained. From 69 cycles, supernatant of the uterine flushes was analyzed with a specific equine MPO ELISA assay to measure MPO concentration. Cytology samples were used for the diagnosis of endometritis. Myeloperoxidase was present in the uterus of all estrus mares in highly variable concentrations. Myeloperoxidase concentrations were significantly (P < 0.05) higher in samples with positive cytologies and in the presence of intraluminal fluid. Occasionally, some samples with negative cytologies showed high MPO concentration, but the opposite was never observed. Cycles presenting hyperedema weren't associated with high concentration of MPO, intraluminal fluid, or positive cytology, making it a poor diagnostic tool of endometritis. PMID:24565475

  11. [How large is the tocopherol accumulation capacity of organs? Long term trials with various high oral alpha-tocopherol doses administered to rats and guinea pigs].

    PubMed

    Elmadfa, I; Walter, A

    1981-01-01

    Accumulation of Tocopherol in Various Organs. 1. The influence of different doses of vitamin E on the absorption and accumulation of tocopherol in blood and various organs was studied in long time feeding experiments with male guinea pigs (Pirbright White W 58) and male Sprague Dawley rats. The experiment with guinea pigs lasted 32 weeks, that with rats 46 weeks. Three groups of 20 animals of each species were fed semisynthetic diets containing 0.003 g (Gr. I = control), 0.203 g (Gr. II) and 1.009 g (Gr. III) D, L-alpha-tocopherol acetate per 100 g diet. The ratio of tocopherol contents in the diets was 1:100:500. 2. The tocopherol excretion in the faeces increased significantly according to the vitamin E intake; the absorption rate of tocopherol behaves inversely proportional to the level of supply. 3. The tocopherol concentration in blood serum, liver, heart and adrenals of animals of the Groups II and III increased significantly in comparison with the control animals. The tocopherol accumulation in blood and the analysed organs depends on species and is organ specific: Organs of rats of the control group contain higher levels of alpha-tocopherol compared with those of the corresponding group of guinea pigs. According to the relative accumulation capacity of the organs for vitamin E (I:II:III) following sequences can be considered: Guinea pigs: adrenals and heart, liver, blood; rats: liver, heart, blood, adrenals. 4. The tocopherol accumulating organs are of limited capacity. The ratio of the tocopherol intake (1:100:500) could not be found in any of the analysed organs. PMID:7319728

  12. High efficiency solar cells for concentrator systems: silicon or multi-junction?

    NASA Astrophysics Data System (ADS)

    Slade, Alexander; Stone, Kenneth W.; Gordon, Robert; Garboushian, Vahan

    2005-08-01

    Amonix has become the first company to begin production of high concentration silicon solar cells where volumes are over 10 MW/year. Higher volumes are available due to the method of manufacture; Amonix solely uses semiconductor foundries for solar cell production. In the previous years of system and cell field testing, this method of manufacturing enabled Amonix to maintain a very low overhead while incurring a high cost for the solar cell. However, recent simplifications to the solar cell processing sequence resulted in cost reduction and increased yield. This new process has been tested by producing small qualities in very short time periods, enabling a simulation of high volume production. Results have included over 90% wafer yield, up to 100% die yield and world record performance (η =27.3%). This reduction in silicon solar cell cost has increased the required efficiency for multi-junction concentrator solar cells to be competitive / advantageous. Concentrator systems are emerging as a low-cost, high volume option for solar-generated electricity due to the very high utilization of the solar cell, leading to a much lower $/Watt cost of a photovoltaic system. Parallel to this is the onset of alternative solar cell technologies, such as the very high efficiency multi-junction solar cells developed at NREL over the last two decades. The relatively high cost of these type of solar cells has relegated their use to non-terrestrial applications. However, recent advancements in both multi-junction concentrator cell efficiency and their stability under high flux densities has made their large-scale terrestrial deployment significantly more viable. This paper presents Amonix's experience and testing results of both high-efficiency silicon rear-junction solar cells and multi-junction solar cells made for concentrated light operation.

  13. High propionic acid fermentations and mineral accumulation in the cecum of rats adapted to different levels of inulin.

    PubMed

    Levrat, M A; Rémésy, C; Demigné, C

    1991-11-01

    The digestive and metabolic effects of inulin (from chicory) were studied in rats adapted to semipurified diets containing 0, 5, 10 or 20% inulin (wt/wt). Moderate levels of inulin (5-10%) did not significantly affect food intake or body weight gain. Dietary inulin resulted in considerably greater cecal fermentation and a significantly greater intraluminal concentration of propionate (peaking at 58.4 mmol/L). A lower concentration of acetate (42.6 mmol/L) was observed in rats fed 20% inulin. Lactic fermentations were observed in rats fed the 10 or 20% inulin diets. The cecal pool of volatile fatty acids tended to reach a plateau in rats fed diets containing more than 10% inulin (up to 600-700 mumol), but volatile fatty acid absorption was a slightly hyperbolic function of the dietary inulin level. Butyrate absorption was proportionally lower than that of propionate. Inulin-containing diets induced an enlargement of the cecal pool of calcium, phosphate and (to a lesser extent) magnesium. There was also an enhanced absorption of these divalent cations. The cecal pool of bile acids was greater in rats fed inulin, and this oligosaccharide displayed a slight hypocholesterolemic effect, even in rats fed the 5% inulin diet. However, plasma triglycerides were depressed only in rats fed the 20% inulin diet. In conclusion, inulin seems very effective in promoting propionic fermentation and in enhancing the calcium content of the large intestine. However, high levels of inulin (greater than 10%) may affect growth in rats and lead to acidic (pH 5.65) cecal fermentation. PMID:1941180

  14. Photosynthetic acclimation to high CO{sub 2} concentration varies with a plant`s capacity to adjust leaf thickness and nitrogen concentration

    SciTech Connect

    Sims, D.A.; Luo, Y.; Ball, J.T.

    1995-06-01

    Photosynthetic capacities (A{sub max}) of plants grown at high CO{sub 2} concentrations can increase, decrease or remain unchanged depending on the species and growth conditions. Increases in A{sub max} are associated with increases in leaf nitrogen concentration and/or leaf thickness. Leaf nitrogen concentration invariably decreases during growth at high CO{sub 2} while leaf thickness often increases. A{sub max} will increase during growth in high CO{sub 2} if the increase in leaf thickness outweighs the decrease in leaf nitrogen concentration. We will present a model that predicts the photosynthetic acclimation response to CO{sub 2} concentration from changes in leaf nitrogen concentration and thickness. The model was also used to predict the acclimation response under various environmental conditions. It is assumed that plants have a limited range of potential adjustment in leaf nitrogen concentration and thickness. Plants already near these limits, such as sun plants with thick leaves or low nitrogen grown plants with low leaf nitrogen concentration, may have limited potential for further adjustment in response to high CO{sub 2}. We predict that growth in high CO{sub 2} will result in upregulation of A{sub max} in low light and high nutrient environments and downregulation and low nutrient environments.

  15. DMR (deacetylation and mechanical refining) processing of corn stover achieves high monomeric sugar concentrations (230 g L-1) during enzymatic hydrolysis and high ethanol concentrations (>10% v/v) during fermentation without hydrolysate purification or concentration

    DOE PAGESBeta

    Chen, Xiaowen; Kuhn, Erik; Jennings, Edward W.; Nelson, Robert; Tao, Ling; Zhang, Min; Tucker, Melvin P.

    2016-04-01

    Distilling and purifying ethanol and other products from second generation lignocellulosic biorefineries adds significant capital and operating costs to biofuel production. The energy usage associated with distillation negatively affects plant gate costs and causes environmental and life-cycle impacts, and the lower titers in fermentation caused by lower sugar concentrations from pretreatment and enzymatic hydrolysis increase energy and water usage and ethanol production costs. In addition, lower ethanol titers increase the volumes required for enzymatic hydrolysis and fermentation vessels increase capital expenditure (CAPEX). Therefore, increasing biofuel titers has been a research focus in renewable biofuel production for several decades. In thismore » work, we achieved approximately 230 g L-1 of monomeric sugars after high solid enzymatic hydrolysis using deacetylation and mechanical refining (DMR) processed corn stover substrates produced at the 100 kg per day scale. The high sugar concentrations and low chemical inhibitor concentrations achieved by the DMR process allowed fermentation to ethanol with titers as high as 86 g L-1, which translates into approximately 10.9% v/v ethanol. To our knowledge, this is the first time that titers greater than 10% v/v ethanol in fermentations derived from corn stover without any sugar concentration or purification steps have been reported. As a result, the potential cost savings from high sugar and ethanol titers achieved by the DMR process are also reported using TEA analysis.« less

  16. Intermolecular interactions in highly concentrated protein solutions upon compression and the role of the solvent.

    PubMed

    Grobelny, S; Erlkamp, M; Möller, J; Tolan, M; Winter, R

    2014-12-14

    The influence of high hydrostatic pressure on the structure and protein-protein interaction potential of highly concentrated lysozyme solutions up to about 370 mg ml(-1) was studied and analyzed using small-angle X-ray scattering in combination with a liquid-state theoretical approach. In the concentration region below 200 mg ml(-1), the interaction parameters of lysozyme solutions are affected by pressure in a nonlinear way, which is probably due to significant changes in the structural properties of bulk water, i.e., due to a solvent-mediated effect. Conversely, for higher concentrated protein solutions, where hydration layers below ∼4 water molecules are reached, the interaction potential turns rather insensitive to compression. The onset of transient (dynamic) clustering is envisaged in this concentration range. Our results also show that pressure suppresses protein nucleation, aggregation and finally crystallization in supersaturated condensed protein solutions. These findings are of importance for controlling and fine-tuning protein crystallization. Moreover, these results are also important for understanding the high stability of highly concentrated protein solutions (as they occur intracellularly) in organisms thriving under hydrostatic pressure conditions such as in the deep sea, where pressures up to the kbar-level are reached. PMID:25494777

  17. Knowledge discovery from high-frequency stream nitrate concentrations: hydrology and biology contributions

    PubMed Central

    Aubert, Alice H.; Thrun, Michael C.; Breuer, Lutz; Ultsch, Alfred

    2016-01-01

    High-frequency, in-situ monitoring provides large environmental datasets. These datasets will likely bring new insights in landscape functioning and process scale understanding. However, tailoring data analysis methods is necessary. Here, we detach our analysis from the usual temporal analysis performed in hydrology to determine if it is possible to infer general rules regarding hydrochemistry from available large datasets. We combined a 2-year in-stream nitrate concentration time series (time resolution of 15 min) with concurrent hydrological, meteorological and soil moisture data. We removed the low-frequency variations through low-pass filtering, which suppressed seasonality. We then analyzed the high-frequency variability component using Pareto Density Estimation, which to our knowledge has not been applied to hydrology. The resulting distribution of nitrate concentrations revealed three normally distributed modes: low, medium and high. Studying the environmental conditions for each mode revealed the main control of nitrate concentration: the saturation state of the riparian zone. We found low nitrate concentrations under conditions of hydrological connectivity and dominant denitrifying biological processes, and we found high nitrate concentrations under hydrological recession conditions and dominant nitrifying biological processes. These results generalize our understanding of hydro-biogeochemical nitrate flux controls and bring useful information to the development of nitrogen process-based models at the landscape scale. PMID:27572284

  18. Knowledge discovery from high-frequency stream nitrate concentrations: hydrology and biology contributions.

    PubMed

    Aubert, Alice H; Thrun, Michael C; Breuer, Lutz; Ultsch, Alfred

    2016-01-01

    High-frequency, in-situ monitoring provides large environmental datasets. These datasets will likely bring new insights in landscape functioning and process scale understanding. However, tailoring data analysis methods is necessary. Here, we detach our analysis from the usual temporal analysis performed in hydrology to determine if it is possible to infer general rules regarding hydrochemistry from available large datasets. We combined a 2-year in-stream nitrate concentration time series (time resolution of 15 min) with concurrent hydrological, meteorological and soil moisture data. We removed the low-frequency variations through low-pass filtering, which suppressed seasonality. We then analyzed the high-frequency variability component using Pareto Density Estimation, which to our knowledge has not been applied to hydrology. The resulting distribution of nitrate concentrations revealed three normally distributed modes: low, medium and high. Studying the environmental conditions for each mode revealed the main control of nitrate concentration: the saturation state of the riparian zone. We found low nitrate concentrations under conditions of hydrological connectivity and dominant denitrifying biological processes, and we found high nitrate concentrations under hydrological recession conditions and dominant nitrifying biological processes. These results generalize our understanding of hydro-biogeochemical nitrate flux controls and bring useful information to the development of nitrogen process-based models at the landscape scale. PMID:27572284

  19. Exploration of the horizontally staggered light guides for high concentration CPV applications.

    PubMed

    Selimoglu, Ozgur; Turan, Rasit

    2012-08-13

    The material and processing costs are still the major drawbacks of the c-Si based photovoltaic (PV) technology. The wafer cost comprises up to 35-40% of the total module cost. New approaches and system designs are needed in order to reduce the share of the wafer cost in photovoltaic energy systems. Here we explore the horizontally staggered light guide solar optics for use in Concentrated Photovoltaic (CPV) applications. This optical system comprises a lens array system coupled to a horizontal light guide which directs the incoming light beam to its edge. We have designed and simulated this system using a commercial ray tracing software (Zemax). The system is more compact, thinner and more robust compared to the conventional CPV systems. Concentration levels as high as 1000x can easily be reached when the system is properly designed. With such a high concentration level, a good acceptance angle of + -1 degree is still be conserved. The analysis of the system reveals that the total optical efficiency of the system could be as high as %94.4 without any anti-reflection (AR) coating. Optical losses can be reduced by just accommodating a single layer AR coating on the initial lens array leading to a %96.5 optical efficiency. Thermal behavior of high concentration linear concentrator is also discussed and compared with a conventional point focus CPV system. PMID:23038554

  20. High-Resolution, Noninvasive, Two-Photon Fluorescence Measurement of Molecular Concentrations in Corneal Tissue

    PubMed Central

    Cui, Liping; Huxlin, Krystel R.; Xu, Lisen; MacRae, Scott

    2011-01-01

    Purpose. To perform high-resolution, noninvasive, calibrated measurements of the concentrations and diffusion profiles of fluorescent molecules in the live cornea after topical application to the ocular surface. Methods. An 800-nm femtosecond laser was used to perform two-photon fluorescence (TPF) axial scanning measurements. Calibration solutions consisting of sodium fluorescein (Na-Fl; concentration range, 0.01%–2.5%) and riboflavin (concentration range, 0.0125%–0.1%) were tested in well slides, and TPF signals were assessed. Excised feline eyeballs preserved in corneal storage medium and with either intact or removed corneal epithelia were then treated with Na-Fl, riboflavin, or fluorescein dextran (Fl-d) of different molecular weight (MW) for 30 minutes. Calibrated TPF was then used immediately to measure the concentration of these molecules across the central corneal depth. Results. The axial resolution of our TPF system was 6 μm, and a linear relationship was observed between TPF signal and low concentrations of most fluorophores. Intact corneas treated with Na-Fl or riboflavin exhibited a detectable penetration depth of only approximately 20 μm, compared with approximately 400 to 600 μm when the epithelium was removed before fluorophore application. Peak concentrations for intact corneas were half those attained with epithelial removal. Debrided corneas treated with 2,000,000 MW Fl-d showed a half-maximum penetration depth of 156.7 μm compared with 384 μm for the 3,000 MW dextran. The peak concentration of the high MW dextran was one quarter that of the lower MW dextran. Conclusions. TPF is an effective, high-resolution, noninvasive method of quantifying the diffusion and concentration of fluorescent molecules across the cornea. PMID:21228379

  1. Effects of prior acute exercise on circulating cytokine concentration responses to a high-fat meal.

    PubMed

    Brandauer, Josef; Landers-Ramos, Rian Q; Jenkins, Nathan T; Spangenburg, Espen E; Hagberg, James M; Prior, Steven J

    2013-08-01

    High-fat meal consumption alters the circulating cytokine profile and contributes to cardiometabolic diseases. A prior bout of exercise can ameliorate the triglyceride response to a high-fat meal, but the interactive effects of exercise and high-fat meals on cytokines that mediate cardiometabolic risk are not fully understood. We investigated the effects of prior exercise on the responses of circulating tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-8, leptin, retinol-binding protein 4 (RBP4), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), placental growth factor (PlGF), and soluble fms-like tyrosine kinase-1 (sFlt-1) to a high-fat meal. Ten healthy men were studied before and 4 h after ingestion of a high-fat meal either with or without ∼50 min of endurance exercise at 70% of VO2 max on the preceding day. In response to the high-fat meal, lower leptin and higher VEGF, bFGF, IL-6, and IL-8 concentrations were evident (P < 0.05 for all). There was no effect of the high-fat meal on PlGF, TNF-α, or RBP4 concentrations. We found lower leptin concentrations with prior exercise (P < 0.05) and interactive effects of prior exercise and the high-fat meal on sFlt-1 (P < 0.05). The high-fat meal increased IL-6 by 59% without prior exercise and 218% with prior exercise (P < 0.05). In conclusion, a prior bout of endurance exercise does not affect all high-fat meal-induced changes in circulating cytokines, but does affect fasting or postprandial concentrations of IL-6, leptin, and sFlt-1. These data may reflect a salutary effect of prior exercise on metabolic responses to a high-fat meal. PMID:24303126

  2. Effects of prior acute exercise on circulating cytokine concentration responses to a high-fat meal

    PubMed Central

    Brandauer, Josef; Landers-Ramos, Rian Q; Jenkins, Nathan T; Spangenburg, Espen E; Hagberg, James M; Prior, Steven J

    2013-01-01

    High-fat meal consumption alters the circulating cytokine profile and contributes to cardiometabolic diseases. A prior bout of exercise can ameliorate the triglyceride response to a high-fat meal, but the interactive effects of exercise and high-fat meals on cytokines that mediate cardiometabolic risk are not fully understood. We investigated the effects of prior exercise on the responses of circulating tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-8, leptin, retinol-binding protein 4 (RBP4), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), placental growth factor (PlGF), and soluble fms-like tyrosine kinase-1 (sFlt-1) to a high-fat meal. Ten healthy men were studied before and 4 h after ingestion of a high-fat meal either with or without ∼50 min of endurance exercise at 70% of VO2 max on the preceding day. In response to the high-fat meal, lower leptin and higher VEGF, bFGF, IL-6, and IL-8 concentrations were evident (P < 0.05 for all). There was no effect of the high-fat meal on PlGF, TNF-α, or RBP4 concentrations. We found lower leptin concentrations with prior exercise (P < 0.05) and interactive effects of prior exercise and the high-fat meal on sFlt-1 (P < 0.05). The high-fat meal increased IL-6 by 59% without prior exercise and 218% with prior exercise (P < 0.05). In conclusion, a prior bout of endurance exercise does not affect all high-fat meal–induced changes in circulating cytokines, but does affect fasting or postprandial concentrations of IL-6, leptin, and sFlt-1. These data may reflect a salutary effect of prior exercise on metabolic responses to a high-fat meal. PMID:24303126

  3. High accumulation of dehydrodiconiferyl alcohol-4-beta-D: -glucoside in free and immobilized Linum usitatissimum cell cultures.

    PubMed

    Attoumbré, Jacques; Charlet, Stéphane; Baltora-Rosset, Sylvie; Hano, Christophe; Raynaud-Le Grandic, Sophie; Gillet, Françoise; Bensaddek, Lamine; Mesnard, François; Fliniaux, Marc-André

    2006-08-01

    As flaxseed mainly accumulates lignans (secoisolariciresinol diglucoside and matairesinol), these compounds were barely or not detected in plant cell suspensions initiated from Linum usitatissimum. In contrast, these cell suspensions were shown to accumulate substantial amounts of a neolignan identified as dehydrodiconiferyl alcohol-4-beta-D: -glucoside (DCG) (up to 47.7 mg g(-1) DW). The formation of this pharmacologically active compound was evaluated as a function of cell growth and in relation to phytohormone balance of the culture media. After establishment of efficient culture conditions, production of DCG was investigated in immobilized plant cell suspensions initiated from plantlet roots of L. usitatissimum. The results indicate that immobilization enhances the DCG production up to 60.0 mg g(-1) DW but depresses the cell growth resulting in no improvement of the total DCG yield. Nevertheless, with immobilized cell suspensions, a release of DCG into the medium is observed allowing an easier recovery. PMID:16523286

  4. Investigating high concentrations of three greenhouse gases in the Los Angeles Basin and San Bernardino Valley

    NASA Astrophysics Data System (ADS)

    Kirpes, R.; Blake, D. R.; Marrero, J.

    2013-12-01

    Following the Montreal Protocol of 1987 calling for the phase-out of CFCs and other ozone depleting substances, HCFCs and HFCs were introduced as alternatives despite still being greenhouse gases with high global warming potentials. In this study, whole air samples were collected during four research flights over Southern California aboard the NASA DC-8 Airborne Science Laboratory as part of the NASA Student Airborne Science Program. These samples were then analyzed by gas chromatography using a suite of detectors for many compounds, including HFC-134a, HCFC-22, and HFC-152a. HCFC-22 is primarily used as a refrigerant, while HFC-134a and HFC-152a are also used as aerosol propellants and foam blowing agents. High concentrations of these three compounds were observed for samples taken at low altitudes over urban areas around Los Angeles and San Bernardino. Exceptionally high concentrations were seen for all three compounds in samples taken near the Ontario and San Bernardino airports. Concentrations of HFC-134a, HCFC-22, and HFC-152a were enhanced above background levels near other airports sampled in the Los Angeles Basin and San Bernardino Valley. It is clear that concentrations of these three gases are higher in the San Bernardino Valley than in the Los Angeles Basin, and locations with exceptionally high concentrations were investigated to identify potential point sources. Concentrations of these three compounds were also compared to data from past SARP missions and data collected at Trinidad Head, California since 2005 as part of the AGAGE network. Comparison of the average values for each of these campaigns reveal that the background concentrations of HFC-134a, HCFC-22, and HFC-152a are all increasing with a strong linear trend in Southern California.

  5. Development of xylose-fermenting yeasts for ethanol production at high acetic acid concentrations

    SciTech Connect

    Mohandas, D.V.; Whelan, D.R.; Panchal, C.J.

    1995-12-31

    Mutants resistant to comparatively high levels of acetic acid were isolated from the xylose-fermenting yeasts Candida shehatae and Pichia Stipitis by adapting these cultures to increasing concentrations of acetic acid grown in shake-flask cultures. These mutants were tested for their ability to ferment xylose in presence of high acetic acid concentrations, in acid hydrolysates of wood, and in hardwood spent sulfite liquor, and compared with their wild-type counterparts and between themselves. The P. stipitis mutant exhibited faster fermentation times, better tolerance to acid hydrolysates, and tolerance to lower pH.

  6. High-efficiency AlGaAs-GaAs Cassegrainian concentrator cells

    NASA Technical Reports Server (NTRS)

    Werthen, J. G.; Hamaker, H. C.; Virshup, G. F.; Lewis, C. R.; Ford, C. W.

    1985-01-01

    AlGaAs-GaAs heteroface space concentrator solar cells have been fabricated by metalorganic chemical vapor deposition. AMO efficiencies as high as 21.1% have been observed both for p-n and np structures under concentration (90 to 100X) at 25 C. Both cell structures are characterized by high quantum efficiencies and their performances are close to those predicted by a realistic computer model. In agreement with the computer model, the n-p cell exhibits a higher short-circuit current density.

  7. The Aqueous Thermodynamics and Complexation Reactions of Anionic Silica and Uranium Species to High Concentration

    SciTech Connect

    Felmy, Andrew R.

    2004-06-01

    Highly basic tank wastes contain several important radionuclides, including 90Sr, 99Tc, and 60Co, as well as actinide elements (i.e., isotopes of U, Pu, and Am). These highly basic tank wastes are known to have leaked into the vadose zone at the Hanford Site. Upon entering the sediments in the vadose zone, the highly basic solutions dissolve large concentrations of silica from the silica and aluminosilicate minerals present in the subsurface. These dissolution reactions alter the chemical composition of the leaking solutions, transforming them from a highly basic (as high 2M NaOH) solution into a pore solution with a very high concentration of dissolved silica and a significantly reduced pH. This moderately basic (pH 9 to 11), high-silica solution has the potential to complex radionuclides and move through the subsurface. Such strong radionuclide complexation is a currently unconsidered transport vector that has the potential to expedite radionuclide transport through the vad ose zone. These strong complexation effects have the ability to significantly alter current conceptual models of contaminant migration beneath leaking tanks. In this project, we are determining the aqueous thermodynamics and speciation of dissolved silica and silica-radionuclide complexes to high silica concentration. We are also initiating studies of U(VI) speciation under strongly basic conditions.

  8. Vitamin E Concentrations in Adults with HIV/AIDS on Highly Active Antiretroviral Therapy

    PubMed Central

    Kaio, Daniella J. Itinoseki; Rondó, Patricia Helen C.; Luzia, Liania Alves; Souza, José Maria P.; Firmino, Aline Vale; Santos, Sigrid Sousa

    2014-01-01

    HIV/AIDS patients are probably more predisposed to vitamin E deficiency, considering that they are more exposed to oxidative stress. Additionally, there are an extensive number of drugs in the highly active antiretroviral therapy (HAART) regimens that may interfere with vitamin E concentrations. The objective of this study was to compare serum concentrations of alpha-tocopherol in 182 HIV/AIDS patients receiving different HAART regimens. The patients were divided into three groups according to regimen: nucleoside analog reverse-transcriptase inhibitors (NRTIs) + non-nucleoside analog reverse-transcriptase inhibitors (NNRTIs); NRTIs + protease inhibitors + ritonavir; NRTIs + other classes. Alpha-tocopherol was assessed by high-performance liquid chromatography. Multiple linear regression analysis was used to evaluate the effects of HAART regimen, time of use, and compliance with the regimen on alpha-tocopherol concentrations. Alpha-tocopherol concentrations were on average 4.12 μmol/L lower for the NRTIs + other classes regimen when compared to the NRTIs + NNRTIs regimen (p = 0.037). A positive association (p < 0.001) was observed between alpha-tocopherol and cholesterol concentrations, a finding due, in part, to the relationship between liposoluble vitamins and lipid profile. This study demonstrated differences in alpha-tocopherol concentrations between patients using different HAART regimens, especially regimens involving the use of new drugs. Long-term prospective cohort studies are needed to monitor vitamin E status in HIV/AIDS patients since the beginning of treatment. PMID:25225815

  9. Antagonistic effects between magnetite nanoparticles and a hydrophobic surfactant in highly concentrated Pickering emulsions.

    PubMed

    Vílchez, Alejandro; Rodríguez-Abreu, Carlos; Menner, Angelika; Bismarck, Alexander; Esquena, Jordi

    2014-05-13

    Herein we present a systematic study of the antagonistic interaction between magnetite nanoparticles (Fe3O4) and nonionic hydrophobic surfactant in Pickering highly concentrated emulsions. Interfacial tension measurements, phase behavior, and emulsion stability studies, combined with electron microscopy observations in polymerized systems and magnetometry, are used to support the discussion. First, stable W/O highly concentrated emulsions were obtained using partially hydrophobized magnetite nanoparticles. These emulsions experienced phase separation when surfactant is added at concentrations as low as 0.05 wt %. Such phase separation arises from the preferential affinity of the surfactant for the nanoparticle surfaces, which remarkably enhances their hydrophobicity, leading to a gradual desorption of nanoparticles from the interface. W/O emulsions were obtained at higher surfactant concentrations, but in this case, these emulsions were mainly stabilized by surfactant molecules. Therefore, stable emulsions could be prepared in two separate ranges of surfactant concentrations. After polymerization, low-density macroporous polymers were obtained, and the adsorption and aggregation of nanoparticles was analyzed by transmission electron microscopy. The progressive displacement of the nanoparticles was revealed: from the oil-water interface, in which aggregated nanoparticles were adsorbed, forming dense layers, to the continuous phase of the emulsions, where small nanoparticle aggregates were randomly dispersed. Interestingly, the results also show that the blocking temperature of the iron oxide superparamagnetic nanoparticles embedded in the macroporous polymers could be modulated by appropriate control of the concentrations of both surfactant and nanoparticles. PMID:24738961

  10. Potential risk of mitomycin C at high concentrations on peripheral nerve structure.

    PubMed

    Sui, Tao; Zhang, Jinhong; Du, Shihao; Su, Changhui; Que, Jun; Cao, Xiaojian

    2014-04-15

    Although the local application of mitomycin C may prevent epidural adhesion after laminectomy, mitomycin C can induce neurotoxicity in optic and acoustic nerves at high concentrations. To determine the safe concentration range for mitomycin C, cotton pads soaked with mitomycin C at different concentrations (0.1, 0.3, 0.5, and 0.7 mg/mL) were immediately applied for 5 minutes to the operation area of rats that had undergone laminectomy at L1. Rat sciatic nerves, instead of dorsal nerves, were used in this study. The results showed that mitomycin C at 0.1-0.5 mg/mL did not damage the structure and function of the sciatic nerve, while at 0.7 mg/mL, mitomycin C significantly reduced the thickness of the sciatic nerve myelin sheath compared with lower concentrations, though no functional change was found. These experimental findings indicate that the local application of mitomycin C at low concentrations is safe to prevent scar adhesion following laminectomy, but that mitomycin C at high concentrations (> 0.7 mg/mL) has potential safety risks to peripheral nerve structures. PMID:25206895

  11. CKA2 functions in H2O2-induced apoptosis and high-temperature stress tolerance by regulating NO accumulation in yeast.

    PubMed

    Liu, Wen-Cheng; Yuan, Hong-Mei; Li, Yun-Hui; Lu, Ying-Tang

    2015-09-01

    Nitric oxide (NO) plays key roles in yeast responses to various environmental factors, such as H2O2 and high temperature. However, the gene encoding NO synthase (NOS) in yeast has not yet been identified, and the mechanism underlying the regulation of NOS-like activity is poorly understood. Here, we report on the involvement of CKA2 in H2O2-induced yeast apoptosis and yeast high-temperature stress tolerance. Our results showed that although Δcka2 mutant had reduced NO accumulation with decreased apoptosis after H2O2 exposure, treatment with a NO donor, sodium nitroprusside, resulted in similar survival rate of Δcka2 mutant compared to that of wild-type yeast when subjected to H2O2 stress. This finding occurred because H2O2-enhanced NOS-like activity in wild-type yeast was significantly repressed in Δcka2. Our additional experiments indicated that both high-temperature-enhanced NO accumulation and NOS-like activity were also suppressed in Δcka2, leading to the hypersensitivity of the mutant to high temperature in terms of changes in survival rate. Thus, our results showed that CKA2 functioned in H2O2-induced apoptosis and high-temperature stress tolerance by regulating NOS-like-dependent NO accumulation in yeast. PMID:26100262

  12. High Frequency Measurements of Methane Concentrations and Carbon Isotopes at a Marsh and Landfill

    NASA Astrophysics Data System (ADS)

    Mortazavi, B.; Wilson, B.; Chanton, J.; Eller, K.; Dong, F.; Baer, D. S.; Gupta, M.; Dzwonkowski, B.

    2012-12-01

    High frequency measurements of methane concentrations and carbon isotopes can help constrain the source strengths of methane emitted to the atmosphere. We report here methane concentrations and 13C values measured at 0.5 Hz with cavity enhanced laser absorption spectrometers (Los Gatos Research) deployed at a saltmarsh in Alabama and a landfill in Florida. Methane concentrations and 13C at the saltmarsh were monitored over a 2.5 day time period at 2 m, 0.5 m above the ground as well as from the outflow of a flow-through (2 L) chamber placed on the Spartina alterniflora dominated marsh. A typical measurement cycle included regular samples from two tanks of known methane concentrations and isotopic values and from ambient air samples. Over the 2.5-day measurement period methane concentrations and isotopic ratios at 2 m averaged 1.85 ppm and -43.57‰ (±0.34, 1 SE), respectively. The concentration and isotopic values from the chamber outflow varied from 1.92 to 5.81 ppm and -38.5 to -59.3‰, respectively. Methane flux from the marsh ranged from undetectable to 3.6 mgC m-2hr-1, with high fluxes measured during low tide. The 13δCH4 of the emitted CH4 from the marsh, determined from a mass balance equation using the chamber inflow and outflow concentration and isotopic values ranged from -62.1 to -93.9‰ and averaged -77‰ (±1.25, 1SE). At the landfill ambient methane concentrations and 13C ratios measured over multiple days varied from 4.25 to 11.91 ppm and from -58.81 to -45.12‰, respectively. At higher methane concentrations the δ13C of CH4 was more depleted consistent with previously observed relationship at this site made by more traditional techniques. Over a 30-minute measurement period CH4 concentrations at the landfill could vary by as much as 15 ppm. The high frequency continuous optical measurements with field-deployed instruments provide us with an unprecedented temporal resolution of CH4 concentrations and isotopic ratios. These measurements will

  13. Phenomena that influence high ozone concentrations in the Paso del Norte area

    SciTech Connect

    MacDonald, C.P.; Roberts, P.T.; Main, H.H.; Dye, T.S.; Yarbrough, J.

    1998-12-31

    This paper summarizes the results of analyses of meteorological and air quality data for the 1996 Paso del Norte Ozone Study. The purpose of these data analyses was to develop an understanding of the significant chemical and physical processes which lead to high concentrations of ozone in the Paso del Norte study region which includes El Paso, TX; Sunland Park, NM; and Juarez, Mexico. This analysis has shown that the high ozone concentrations are a result of slow convective boundary layer growth, reduced convective boundary layer depth, light surface winds, and high morning surface ozone precursor concentrations. Overlying meteorological conditions observed during high ozone episodes include an upstream aloft high pressure system, aloft warming, and weak surface pressure gradients. The analysis has also shown that aloft carryover of ozone and ozone precursors does not significantly contribute to the surface ozone concentration. Furthermore, hydrocarbon and NO{sub x} data, although spatially limited, show that the system is most often NO{sub x} rather than VOC limited.

  14. Comparison of charged nanoparticle concentrations near busy roads and overhead high-voltage power lines.

    PubMed

    Jayaratne, E R; Ling, X; Morawska, L

    2015-09-01

    Overhead high-voltage power lines are known sources of corona ions. These ions rapidly attach to aerosols to form charged particles in the environment. Although the effect of ions and charged particles on human health is largely unknown, much attention has focused on the increasing exposure as a result of the expanding power network in urban residential areas. However, it is not widely known that a large number of charged particles in urban environments originate from motor vehicle emissions. In this study, for the first time, we compare the concentrations of charged nanoparticles near busy roads and overhead power lines. We show that large concentrations of both positive and negative charged nanoparticles are present near busy roadways and that these concentrations commonly exceed those under high-voltage power lines. We estimate that the concentration of charged nanoparticles found near two freeways carrying around 120 vehicles per minute exceeded the corresponding maximum concentrations under two corona-emitting overhead power lines by as much as a factor of 5. The difference was most pronounced when a significant fraction of traffic consisted of heavy-duty diesel vehicles which typically have high particle and charge emission rates. PMID:25917858

  15. Potential of membrane distillation for production of high quality fruit juice concentrate.

    PubMed

    Onsekizoglu Bagci, Pelin

    2015-01-01

    Fruit juices are generally concentrated in order to improve the stability during storage and to reduce handling, packaging, and transportation costs. Thermal evaporation is the most widely used technique in industrial fruit juice concentrate production. In addition to high energy consumption, a large part of the characteristics determining the quality of the fresh juice including aroma, color, vitamins, and antioxidants undergoes remarkable alterations through the use of high operation temperatures. Increasing consumer demand for minimally or naturally processed stable products able to retain as much possible the uniqueness of the fresh fruit has engendered a growing interest for development of nonthermal approaches for fruit juice concentration. Among them, membrane distillation (MD) and its variants have attracted much attention for allowing very high concentrations to be reached under atmospheric pressure and temperatures near ambient temperature. This review will provide an overview of the current status and recent developments in the use of MD for concentration of fruit juices. In addition to the most basic concepts of MD variants, crucial suggestions for membrane selection and operating parameters will be presented. Challenges and future trends for industrial adaptation taking into account the possibility of integrating MD with other existing processes will be discussed. PMID:24915342

  16. Highly Efficient Large-Scale Lentiviral Vector Concentration by Tandem Tangential Flow Filtration

    PubMed Central

    Cooper, Aaron R.; Patel, Sanjeet; Senadheera, Shantha; Plath, Kathrin; Kohn, Donald B.; Hollis, Roger P.

    2014-01-01

    Large-scale lentiviral vector (LV) concentration can be inefficient and time consuming, often involving multiple rounds of filtration and centrifugation. This report describes a simpler method using two tangential flow filtration (TFF) steps to concentrate liter-scale volumes of LV supernatant, achieving in excess of 2000-fold concentration in less than 3 hours with very high recovery (>97%). Large volumes of LV supernatant can be produced easily through the use of multi-layer flasks, each having 1720 cm2 surface area and producing ~560 mL of supernatant per flask. Combining the use of such flasks and TFF greatly simplifies large-scale production of LV. As a demonstration, the method is used to produce a very high titer LV (>1010 TU/mL) and transduce primary human CD34+ hematopoietic stem/progenitor cells at high final vector concentrations with no overt toxicity. A complex LV (STEMCCA) for induced pluripotent stem cell generation is also concentrated from low initial titer and used to transduce and reprogram primary human fibroblasts with no overt toxicity. Additionally, a generalized and simple multiplexed real- time PCR assay is described for lentiviral vector titer and copy number determination. PMID:21784103

  17. Enhanced energy conversion efficiency from high strength synthetic organic wastewater by sequential dark fermentative hydrogen production and algal lipid accumulation.

    PubMed

    Ren, Hong-Yu; Liu, Bing-Feng; Kong, Fanying; Zhao, Lei; Xing, Defeng; Ren, Nan-Qi

    2014-04-01

    A two-stage process of sequential dark fermentative hydrogen production and microalgal cultivation was applied to enhance the energy conversion efficiency from high strength synthetic organic wastewater. Ethanol fermentation bacterium Ethanoligenens harbinense B49 was used as hydrogen producer, and the energy conversion efficiency and chemical oxygen demand (COD) removal efficiency reached 18.6% and 28.3% in dark fermentation. Acetate was the main soluble product in dark fermentative effluent, which was further utilized by microalga Scenedesmus sp. R-16. The final algal biomass concentration reached 1.98gL(-1), and the algal biomass was rich in lipid (40.9%) and low in protein (23.3%) and carbohydrate (11.9%). Compared with single dark fermentation stage, the energy conversion efficiency and COD removal efficiency of two-stage system remarkably increased 101% and 131%, respectively. This research provides a new approach for efficient energy production and wastewater treatment using a two-stage process combining dark fermentation and algal cultivation. PMID:24582427

  18. Acute administration of high doses of taurine does not substantially improve high-intensity running performance and the effect on maximal accumulated oxygen deficit is unclear.

    PubMed

    Milioni, Fabio; Malta, Elvis de Souza; Rocha, Leandro George Spinola do Amaral; Mesquita, Camila Angélica Asahi; de Freitas, Ellen Cristini; Zagatto, Alessandro Moura

    2016-05-01

    The aim of the present study was to investigate the effects of acute administration of taurine overload on time to exhaustion (TTE) of high-intensity running performance and alternative maximal accumulated oxygen deficit (MAODALT). The study design was a randomized, placebo-controlled, crossover design. Seventeen healthy male volunteers (age: 25 ± 6 years; maximal oxygen uptake: 50.5 ± 7.6 mL·kg(-1)·min(-1)) performed an incremental treadmill-running test until voluntary exhaustion to determine maximal oxygen uptake and exercise intensity at maximal oxygen uptake. Subsequently, participants completed randomly 2 bouts of supramaximal treadmill-running at 110% exercise intensity at maximal oxygen uptake until exhaustion (placebo (6 g dextrose) or taurine (6 g) supplementation), separated by 1 week. MAODALT was determined using a single supramaximal effort by summating the contribution of the phosphagen and glycolytic pathways. When comparing the results of the supramaximal trials (i.e., placebo and taurine conditions) no differences were observed for high-intensity running TTE (237.70 ± 66.00 and 277.30 ± 40.64 s; p = 0.44) and MAODALT (55.77 ± 8.22 and 55.06 ± 7.89 mL·kg(-1); p = 0.61), which seem to indicate trivial and unclear differences using the magnitude-based inferences approach, respectively. In conclusion, acute 6 g taurine supplementation before exercise did not substantially improve high-intensity running performance and showed an unclear effect on MAODALT. PMID:27109264

  19. Purification and partial kinetic and physical characterization of two NADP-specific glutamate dehydrogenase isoenzymes and their protein precursors, and measurement of the patterns of accumulation and rates of degradation of their nonidentical subunits in synchronized cells of Chlorella cultured in different concentrations of ammonia

    SciTech Connect

    Bascomb, N.F.

    1986-01-01

    Two ammonium-inducible, chloroplast-localized, NADP-specific glutamate dehydrogenases were purified from Chlorella sorokiniana. They were homopolymers of either alpha or beta subunits with molecular weights of 55,500 and 53,000, respectively. These isoenzymes were separated by their differential binding to the substrate affinity column. Peptide mapping of purified alpha and beta subunits showed them to have a high degree of sequence homology. By use of SDS slab-gel electrophoresis and a Western blot/immunodetection procedure, patterns of accumulation of alpha and beta subunits (in their holoenzyme) were measured in cells cultured in media, containing different concentrations of ammonia. Pulse-chase experiments with (/sup 35/S)sulfate were performed to measured the rates of degradation of the two isoenzymes. When the culture medium contained 2 mM ammonia or lower, cells accumulated only the alpha holoenzyme. Above 2 mM ammonia, cells contained both enzymes; however, their patterns of accumulation and rates of degradation were very different. The physiological role of alpha and beta holoenzymes appears to be ammonia assimilation at low and high external ammonia concentrations, respectively. From in vitro-translation studies with total cellular poly(A)/sup +/RNA, isolated from cells engaged in synthesis of alpha or beta holoenzymes or both, it was concluded that alpha and beta subunits have protein precursor(s) or identical molecular weight (M/sub r/ = 58,500). When the putative protein-precursor(s) were incubated in vitro, with cell-free extracts from Chlorella cells, they were processed to proteins the size of alpha and beta subunits.

  20. Effects of high temperature stress at different development stages on soybean isoflavone and tocopherol concentrations.

    PubMed

    Chennupati, Pratyusha; Seguin, Philippe; Liu, Wucheng

    2011-12-28

    Soybean contains a range of compounds with putative health benefits including isoflavones and tocopherols. A study was conducted to determine the effects on these compounds of high temperature stress imposed at specific development stages [i.e., none, pre-emergence, vegetative, early reproductive (R1-4), late-reproductive (R5-8), or all stages]. Two cultivars (AC Proteina and OAC Champion) were grown in growth chambers set at contrasting temperatures [i.e., stress conditions of 33/25 °C (day/night temperature) and control conditions of 23/15 °C] in order to generate these treatments. Isoflavone and tocopherol concentrations in mature seeds were determined using high-performance liquid chromatography. In both cultivars isoflavone response was greatest when stress occurred during the R5-8 stages and during all development stages, these treatments reducing total isoflavone concentration by an average of 85% compared to the control. Stress imposed at other stages also affected isoflavone concentration although the response was smaller. For example, stress during the vegetative stages reduced total isoflavones by 33% in OAC Champion. Stress imposed pre-emergence had an opposite effect increasing daidzein concentration by 24% in AC Proteina. Tocopherol concentrations were affected the most when stress was imposed during all stages of development, followed by stress restricted to stages R5-8; response to stress during other stages was limited. The specific response of tocopherols differed, α-tocopherol being increased by high temperature by as much as 752%, the reverse being observed for δ-tocopherol and γ-tocopherol. The present study demonstrates that while isoflavone and tocopherol concentrations in soybeans are affected the most by stress occurring during seed formation, concentrations can also be affected by stress occurring at other stages including stages as early as pre-emergence. PMID:22098462

  1. Inhibition effects of high calcium concentration on anaerobic biological treatment of MSW leachate.

    PubMed

    Xia, Yi; He, Pin-Jing; Pu, Hong-Xia; Lü, Fan; Shao, Li-Ming; Zhang, Hua

    2016-04-01

    With the increasing use of municipal solid waste incineration (MSWI) and more stringent limits on landfilling of organic waste, more MSWI bottom ash is being landfilled, and the proportion of inorganic wastes in landfills is increasing, causing the increased Ca concentrations in landfill leachate. In this research, the inhibition effect of Ca concentration on the anaerobic treatment of landfill leachate was studied using a biochemical methane potential experiment. Slight inhibition of methane production occurred when the addition of Ca concentration was less than 2000 mg/L. When the addition of Ca concentration was between 6000 and 8000 mg/L, methane production was significantly reduced (to 29.4-34.8 % of that produced by the BLK reactor), and the lag phase was increased from 8.55 to 16.32 d. Moreover, when the dosage of Ca concentration increased from zero to 8000 mg/L, reductions in solution Ca concentration increased from 929 to 2611 mg/L, and the proportion of Ca in the residual sludge increased from 22.58 to 46.87 %. Based on the results, when the dosage of Ca concentration was less than 4000 mg/L, the formation of Ca precipitates on the surface of sludge appeared to prevent mass transfer and was the dominant reason for the reduction in methane production and sludge biomass. At higher Ca concentrations (6000-8000 mg/L), the severe inhibition of methane production appeared to be caused by the toxic effect of highly concentrated Ca on sludge as well as mass transfer blockage. PMID:26769478

  2. Archean high δ18O Mg-diorite: crustal-derived melt hybridized with enriched mafic accumulated rocks

    NASA Astrophysics Data System (ADS)

    Wang, Dan; Guo, Jing-Hui

    2016-04-01

    The genesis of Mg-diorite or sanukitoids has significances to understand the crustal growth and tectonic style in Archean. The chemical compositions of minerals and rocks, whole-rock Sm-Nd isotope, zircon SIMS U-Pb ages and Hf-O isotopes of Zhulagou (ZLG) Mg-diorite and their mafic enclaves (Yinshan Block, North China Craton) were studied to place constraints on their sources and genesis, and therefore provide information about dynamic processes. The ~2520 Ma ZLG diorites have intermediate SiO2 (59.4-65.5 wt.%), high Mg# (49-52), Cr (90.4-438 ppm), Ni (15.0-95.9 ppm), Sr (436-882 ppm) and Ba (237-1206 ppm) contents with fractionated rare earth elements (REE, LaN/YbN = 9.1-40.5) and depleted high field-strength element (HFSE, e.g. Nb, Ta and Ti). These geochemical signatures are similar to those Archean high-Mg diorites and sanukitoids. However, they are sodic with low K2O/Na2O (0.14-0.49) ratios, exhibiting an affinity with Archean trondhjemite-tonalite-granodiorite (TTG). Abundant coeval amphibole-bearing mafic enclaves (~2525 Ma) are enclosed within the ZLG diorites. They display low SiO2 (46.5-50.3 wt.%) contents but high concentrations of MgO (9.0-14.5 wt.%), Cr (647-1946 ppm) and Ni (197-280 ppm). They are enriched in K2O (0.64-3.43 wt.%) and large ion lithophile element (LILE), depleted in Nb, Ta and Ti. Combined with their concave REE patterns and prominent negative Eu anomaly, we suggest that they are cumulates of the melt which probably derived from subduction-related Archean metasomatized mantle source. Mineral trace element modelling results, similar ɛNd(t) (+0.6 to +2.3) and δ18O(Zrc) values (~8.6-9.0 ‰) of the diorites and mafic enclaves, strongly reflect that they had experienced intense interaction and hybridization. Evolved whole-rock Nd isotopes (TDM = 2.80-2.70 Ga), variable zircon ɛHf (t) (-1.6 to +6.0) and high δ18O (~9.0 ‰) values of the diorites indicate that they most likely originated from melting of an older continental crust (≥ 2

  3. Elongation factor 1 alpha concentration is highly correlated with the lysine content of maize endosperm.

    PubMed Central

    Habben, J E; Moro, G L; Hunter, B G; Hamaker, B R; Larkins, B A

    1995-01-01

    Lysine is the most limiting essential amino acid in cereals, and for many years plant breeders have attempted to increase its concentration to improve the nutritional quality of these grains. The opaque2 mutation in maize doubles the lysine content in the endosperm, but the mechanism by which this occurs is unknown. We show that elongation factor 1 alpha (EF-1 alpha) is overexpressed in opaque2 endosperm compared with its normal counterpart and that there is a highly significant correlation between EF-1 alpha concentration and the total lysine content of the endosperm. This relationship is also true for two other cereals, sorghum and barley. It appears that genetic selection for genotypes with a high concentration of EF-1 alpha can significantly improve the nutritional quality of maize and other cereals. Images Fig. 1 Fig. 2 PMID:7567989

  4. Preparation of a high concentration of lithium-7 atoms in a magneto-optical trap

    SciTech Connect

    Zelener, B. B. Saakyan, S. A.; Sautenkov, V. A.; Manykin, E. A.; Zelener, B. V.; Fortov, V. E.

    2014-11-15

    This study is aimed at obtaining high concentration of optically cooled lithium-7 atoms for preparing strongly interacting ultracold plasma and Rydberg matter. A special setup has been constructed, in which two high-power semiconductor lasers are used to cool lithium-7 atoms in a magneto-optical trap. At an optimum detuning of the cooling laser frequency and a magnetic field gradient of 35 G/cm, the concentration of ultracold lithium-7 atoms reaches about 10{sup 11} cm{sup −3}. Additional independent information about the concentration and number of ultracold lithium-7 atoms on different sublevels of the ground state was obtained by using of an additional probing laser.

  5. Airborne laser scan measurements of winter snow accumulation in high alpine catchments - hydrological implications and verification by ground penetrating radar at glacier surface

    NASA Astrophysics Data System (ADS)

    Helfricht, K.; Keuschnig, M.; Heilig, A.; Mayer, C.; Kuhn, M.

    2012-04-01

    The snow cover as storage of winter precipitation is a substantial source for runoff generation in high mountain catchments. Redistribution of solid precipitation, caused by wind and gravity, leads to a characteristic spatial distribution of snow accumulation which differs from simple model assumption of a homogenous snowpack increasing with altitude. Both, the distinct distribution of snow accumulation and the total amount of SWE stored in the snow cover, affect the magnitude and seasonality of melt water runoff. Complex relations exist between the spatial pattern of snow accumulation and the presence of glaciers and vice versa. For proper hydrological modeling in high mountain catchments, knowledge about snow cover distribution is an important requirement. To date, to evaluate modeling results, spatially insufficient point data on snow depths and SWE are usually available. On catchment scale, optical space-borne remote sensing techniques deliver areal extent of snow cover, but no snow depths and hence no volume of snow cover. Multi-temporal airborne laser scanning (ALS) is an active remote sensing method to obtain elevation changes extensively even in inaccessible alpine terrain. Before the start and at the end of accumulation season of winter 2010/2011, two airborne laser scan acquisitions were performed in the Ötztal Alps (Tirol, Austria). Differences of the respective digital elevation models were interpreted as snow depths and converted into SWE using a simple regression method between snow depths and snow density. Preferred snow accumulation areas were determined, e.g. wind sheltered depressions, the base of steep mountain walls and flat glacier surfaces. At catchment scale, solid precipitation is obviously redistributed from wind exposed mountain ridges to lower elevations, inducing characteristic elevations of maximum snow accumulation. Overall, catchment precipitation derived from snow accumulation is a valuable reference for precipitation approaches in

  6. Comparative Transcriptome Analysis between Low- and High-Cadmium-Accumulating Genotypes of Pakchoi (Brassica chinensis L.) in Response to Cadmium Stress.

    PubMed

    Zhou, Qian; Guo, Jing-Jie; He, Chun-Tao; Shen, Chuang; Huang, Ying-Ying; Chen, Jing-Xin; Guo, Jian-Hua; Yuan, Jian-Gang; Yang, Zhong-Yi

    2016-06-21

    To reduce cadmium (Cd) pollution of food chains, screening and breeding of low-Cd-accumulating cultivars are the focus of much study. Two previously identified genotypes, a low-Cd-accumulating genotype (LAJK) and a high-Cd-accumulating genotype (HAJS) of pakchoi (Brassica chinesis L.), were stressed by Cd (12.5 μM) for 0 h (T0), 3 h (T3) and 24 h (T24). By comparative transcriptome analysis for root tissue, 3005 and 4343 differentially expressed genes (DEGs) were identified in LAJK at T3 (vs T0) and T24 (vs T3), respectively, whereas 8677 and 5081 DEGs were detected in HAJS. Gene expression pattern analysis suggested a delay of Cd responded transcriptional changes in LAJK compared to HAJS. DEG functional enrichments proposed genotype-specific biological processes coped with Cd stress. Cell wall biosynthesis and glutathione (GSH) metabolism were found to involve in Cd resistance in HAJS, whereas DNA repair and abscisic acid (ABA) signal transduction pathways played important roles in LAJK. Furthermore, the genes participating in Cd efflux such as PDR8 were overexpressed in LAJK, whereas those responsible for Cd transport such as YSL1 were more enhanced in HAJS, exhibiting different Cd transport processes between two genotypes. These novel findings should be useful for molecular assisted screening and breeding of low-Cd-accumulating genotypes for pakchoi. PMID:27228483

  7. Interculturalism in Italian Primary Schools with a High Concentration of Immigrant Students

    ERIC Educational Resources Information Center

    Catarci, Marco

    2013-01-01

    The present article focuses on quantitative research carried out on a statistically representative sample of Italian primary schools with a high concentration of immigrant students. Research data show that schools with a higher number of immigrant students offer a greater number and a wider variety of intercultural initiatives. The presence of…

  8. Selection of respiratory protection devices for use in very high concentrations of airborne plutonium.

    PubMed

    Bianconi, C J

    2000-08-01

    This paper focuses on the proper selection of respiratory protection devices for use in very high concentrations of airborne plutonium. Special attention is given to the determination of levels at which airborne plutonium presents a hazard that is immediately dangerous to life or health. PMID:10910403