Science.gov

Sample records for acid tca precipitation

  1. Glycation inhibits trichloroacetic acid (TCA)-induced whey protein precipitation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four different WPI saccharide conjugates were successfully prepared to test whether glycation could inhibit WPI precipitation induced by trichloroacetic acid (TCA). Conjugates molecular weights after glycation were analyzed with SDS-PAGE. No significant secondary structure change due to glycation wa...

  2. IRIS Toxicological Review of Trichloroacetic Acid (TCA) ...

    EPA Pesticide Factsheets

    EPA is releasing the draft report, Toxicological Review of Trichloroacetic Acid (TCA), that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development Process. Comments received from other Federal agencies and White House Offices are provided below with external peer review panel comments. The draft Toxicological Review of Trichloroacetic Acid provides scientific support and rationale for the hazard identification and dose-response assessment pertaining to chronic exposure to trichloroacetic acid.

  3. IRIS Toxicological Review of Trichloroacetic Acid (TCA) ...

    EPA Pesticide Factsheets

    EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of Trichloroacetic acid (TCA) that when finalized will appear on the Integrated Risk Information System (IRIS) database. The draft Toxicological Review of trichloroacetic acid provides scientific support and rationale for the hazard and dose-response assessment pertaining to chronic exposure to trichloroacetic acid.

  4. IRIS Toxicological Review of Trichloroacetic Acid (TCA) ...

    EPA Pesticide Factsheets

    On September 24, 2009, the Toxicological Review of Trichloroacetic Acid (TCA) and the charge to external peer reviewers were released for external peer review and public comment. The Toxicological Review and charge were reviewed internally by EPA and by other federal agencies and White House Offices before public release. In the new IRIS process, introduced by the EPA Administrator, all written comments on IRIS assessments submitted by other federal agencies and White House Offices will be made publicly available. Accordingly, interagency comments and the interagency science consultation draft of the IRIS Toxicological Review of Trichloroacetic Acid and the charge to external peer reviewers are posted on this site. The draft Toxicological Review of Trichloroacetic Acid provides scientific support and rationale for the hazard identification and dose-response assessment pertaining to chronic exposure to trichloroacetic acid.

  5. IRIS Toxicological Review of Trichloroacetic Acid (TCA) (External Review Draft)

    EPA Science Inventory

    EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of Trichloroacetic acid (TCA) that when finalized will appear on the Integrated Risk Information System (IRIS) database.

  6. Metabolism: Part II. The Tricarboxylic Acid (TCA), Citric Acid, or Krebs Cycle.

    ERIC Educational Resources Information Center

    Bodner, George M.

    1986-01-01

    Differentiates the tricarboxylic acid (TCA) cycle (or Krebs cycle) from glycolysis, and describes the bridge between the two as being the conversion of pyruvate into acetyl coenzyme A. Discusses the eight steps in the TCA cycle, the results of isotopic labeling experiments, and the net effects of the TCA cycle. (TW)

  7. Acidic precipitation

    SciTech Connect

    Martin, H.C.

    1987-01-01

    At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

  8. Acid Precipitation

    ERIC Educational Resources Information Center

    Likens, Gene E.

    1976-01-01

    Discusses the fact that the acidity of rain and snow falling on parts of the U.S. and Europe has been rising. The reasons are still not entirely clear and the consequences have yet to be well evaluated. (MLH)

  9. Comparative study of 15% TCA peel versus 35% glycolic acid peel for the treatment of melasma

    PubMed Central

    Puri, Neerja

    2012-01-01

    Background: Chemical peels are the mainstay of a cosmetic practitioner's armamentarium because they can be used to treat some skin disorders and can provide aesthetic benefit. Objectives: To compare 15% TCA peel and 35% glycolic acid peel for the treatment of melasma. Material and Methods: We selected 30 participants of melasma aged between 20 and 50 years from the dermatology outpatient department and treated equal numbers with 15% TCA and 35% glycolic acid. Results: Subjective response as graded by the patient showed good or very good response in 70% participants in the glycolic acid group and 64% in the TCA group. Conclusions: There was statistically insignificant difference in the efficacy between the two groups for the treatment of melasma. PMID:23130283

  10. IRIS Toxicological Review of Trichloroacetic Acid (Tca) (Final ...

    EPA Pesticide Factsheets

    EPA has finalized the Toxicological Review of Trichloroacetic Acid: in support of the Integrated Risk Information System (IRIS). Now final, this assessment may be used by EPA’s program and regional offices to inform decisions to protect human health. The draft Toxicological Review of Trichloroacetic Acid provides scientific support and rationale for the hazard identification and dose-response assessment pertaining to chronic exposure to trichloroacetic acid.

  11. P-cadherin expression in skin peeled with phenol or trichloroacetic acid (TCA).

    PubMed

    Yamamoto, Yuki; Uede, Koji; Ohtani, Toshio; Wakita, Hisashi; Furukawa, Fukumi

    2003-12-01

    P-cadherin expression patterns were studied in trichloroacetic acid (TCA) or phenol treated skin. The expression was absent or very weak on the basal cell surfaces by day 2. Seven days after peeling, P-cadherin was clearly distributed in a continuous granular pattern over the cell surface of the entire epidermis of the 40% TCA treated skin, in a weak granular pattern on a few suprabasal cells and basal cells of the phenol treated skin, and very weakly expressed on the lateral surfaces and in the cytoplasm of basal cells of the 60% TCA treated skin. Based on the present results and previous reports, it is likely that there are distinct patterns of P cadherin expression. Furthermore, a specific type of P cadherin expression might be involved in wound healing in general, which could provide new insights into tissue repair mechanisms after chemical peeling.

  12. IRIS Toxicological Review of Trichloroacetic Acid (TCA) (Interagency Science Discussion Draft)

    EPA Science Inventory

    EPA is releasing the draft report, Toxicological Review of Trichloroacetic Acid (TCA), that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development ...

  13. IRIS Toxicological Review of Trichloroacetic Acid (Tca) (Final Report)

    EPA Science Inventory

    EPA has finalized the Toxicological Review of Trichloroacetic Acid: in support of the Integrated Risk Information System (IRIS). Now final, this assessment may be used by EPA’s program and regional offices to inform decisions to protect human health.

  14. [Construction and fermentation control of reductive TCA pathway for malic acid production in Saccharomyces cerevisiae].

    PubMed

    Yan, Daojiang; Wang, Caixia; Zhou, Jiemin; Liu, Yilan; Yang, Maohua; Xing, Jianmin

    2013-10-01

    Malic acid is widely used in food, and chemical industries. Through overexpressing pyruvate carboxylase and malate dehydrogenase in pdc1-deficient Saccharomyces cerevisiae, malic acid was successfully produced through the reductive TCA pathway. No malic acid was detected in wild type Saccharomyces cerevisiae, however, 45 mmol/L malic acid was produced in engineered strain, and the concentration of byproduct ethanol also reduced by 18%. The production of malic acid enhanced 6% by increasing the concentration of Ca2+. In addition, the final concentration reached 52.5 mmol/L malic acid by addition of biotin. The increasing is almost 16% higher than that of the original strain.

  15. Effects of intermediate metabolite carboxylic acids of TCA cycle on Microcystis with overproduction of phycocyanin.

    PubMed

    Bai, Shijie; Dai, Jingcheng; Xia, Ming; Ruan, Jing; Wei, Hehong; Yu, Dianzhen; Li, Ronghui; Jing, Hongmei; Tian, Chunyuan; Song, Lirong; Qiu, Dongru

    2015-04-01

    Toxic Microcystis species are the main bloom-forming cyanobacteria in freshwaters. It is imperative to develop efficient techniques to control these notorious harmful algal blooms (HABs). Here, we present a simple, efficient, and environmentally safe algicidal way to control Microcystis blooms, by using intermediate carboxylic acids from the tricarboxylic acid (TCA) cycle. The citric acid, alpha-ketoglutaric acid, succinic acid, fumaric acid, and malic acid all exhibited strong algicidal effects, and particularly succinic acid could cause the rapid lysis of Microcystis in a few hours. It is revealed that the Microcystis-lysing activity of succinic acid and other carboxylic acids was due to their strong acidic activity. Interestingly, the acid-lysed Microcystis cells released large amounts of phycocyanin, about 27-fold higher than those of the control. On the other hand, the transcription of mcyA and mcyD of the microcystin biosynthesis operon was not upregulated by addition of alpha-ketoglutaric acid and other carboxylic acids. Consider the environmental safety of intermediate carboxylic acids. We propose that administration of TCA cycle organic acids may not only provide an algicidal method with high efficiency and environmental safety but also serve as an applicable way to produce and extract phycocyanin from cyanobacterial biomass.

  16. 2-Oxoglutarate: linking TCA cycle function with amino acid, glucosinolate, flavonoid, alkaloid, and gibberellin biosynthesis

    PubMed Central

    Araújo, Wagner L.; Martins, Auxiliadora O.; Fernie, Alisdair R.; Tohge, Takayuki

    2014-01-01

    The tricarboxylic acid (TCA) cycle intermediate 2-oxoglutarate (2-OG) is used as an obligatory substrate in a range of oxidative reactions catalyzed by 2-OG-dependent dioxygenases. These enzymes are widespread in nature being involved in several important biochemical processes. We have recently demonstrated that tomato plants in which the TCA cycle enzyme 2-OG dehydrogenase (2-ODD) was antisense inhibited were characterized by early senescence and modified fruit ripening associated with differences in the levels of bioactive gibberellin (GA). Accordingly, there is now compelling evidence that the TCA cycle plays an important role in modulating the rate of flux from 2-OG to amino acid metabolism. Here we discuss recent advances in the biochemistry and molecular biology of 2-OG metabolism occurring in different biological systems indicating the importance of 2-OG and 2-OG dependent dioxygenases not only in glucosinolate, flavonoid and alkaloid metabolism but also in GA and amino acid metabolism. We additionally summarize recent findings regarding the impact of modification of 2-OG metabolism on biosynthetic pathways involving 2-ODDs. PMID:25360142

  17. Engineering rTCA pathway and C4-dicarboxylate transporter for L-malic acid production.

    PubMed

    Chen, Xiulai; Wang, Yuancai; Dong, Xiaoxiang; Hu, Guipeng; Liu, Liming

    2017-02-22

    L-Malic acid is an important component of a vast array of food additives, antioxidants, disincrustants, pharmaceuticals, and cosmetics. Here, we presented a pathway optimization strategy and a transporter modification approach to reconstruct the L-malic acid biosynthesis pathway and transport system, respectively. First, pyruvate carboxylase (pyc) and malate dehydrogenase (mdh) from Aspergillus flavus and Rhizopus oryzae were combinatorially overexpressed to construct the reductive tricarboxylic acid (rTCA) pathway for L-malic acid biosynthesis. Second, the L-malic acid transporter (Spmae) from Schizosaccharomyces pombe was engineered by removing the ubiquitination motification to enhance the L-malic acid efflux system. Finally, the L-malic acid pathway was optimized by controlling gene expression levels, and the final L-malic acid concentration, yield, and productivity were up to 30.25 g L(-1), 0.30 g g(-1), and 0.32 g L(-1) h(-1) in the resulting strain W4209 with CaCO3 as a neutralizing agent, respectively. In addition, these corresponding parameters of pyruvic acid remained at 30.75 g L(-1), 0.31 g g(-1), and 0.32 g L(-1) h(-1), respectively. The metabolic engineering strategy used here will be useful for efficient production of L-malic acid and other chemicals.

  18. Mitochondrial TCA cycle intermediates regulate body fluid and acid-base balance.

    PubMed

    Peti-Peterdi, János

    2013-07-01

    Intrarenal control mechanisms play an important role in the maintenance of body fluid and electrolyte balance and pH homeostasis. Recent discoveries of new ion transport and regulatory pathways in the distal nephron and collecting duct system have helped to better our understanding of these critical kidney functions and identified new potential therapeutic targets and approaches. In this issue of the JCI, Tokonami et al. report on the function of an exciting new paracrine mediator, the mitochondrial the citric acid(TCA) cycle intermediate α-ketoglutarate (αKG), which via its OXGR1 receptor plays an unexpected, nontraditional role in the adaptive regulation of renal HCO(3⁻) secretion and salt reabsorption.

  19. Mitochondrial TCA cycle intermediates regulate body fluid and acid-base balance

    PubMed Central

    Peti-Peterdi, János

    2013-01-01

    Intrarenal control mechanisms play an important role in the maintenance of body fluid and electrolyte balance and pH homeostasis. Recent discoveries of new ion transport and regulatory pathways in the distal nephron and collecting duct system have helped to better our understanding of these critical kidney functions and identified new potential therapeutic targets and approaches. In this issue of the JCI, Tokonami et al. report on the function of an exciting new paracrine mediator, the mitochondrial the citric acid (TCA) cycle intermediate α-ketoglutarate (αKG), which via its OXGR1 receptor plays an unexpected, nontraditional role in the adaptive regulation of renal HCO3– secretion and salt reabsorption. PMID:23926603

  20. Editorial: Acid precipitation

    SciTech Connect

    1995-09-01

    This editorial focuses on acid rain and the history of public and governmental response to acid rain. Comments on a book by Gwineth Howell `Acid Rain and Acid Waters` are included. The editor feels that Howells has provide a service to the environmental scientific community, with a textbook useful to a range of people, as well as a call for decision makers to learn from the acid rain issue and use it as a model for more sweeping global environmental issues. A balance is needed among several parameters such as level of evidence, probability that the evidence will lead to a specific direction and the cost to the global community. 1 tab.

  1. Acid Precipitation: Causes and Consequences.

    ERIC Educational Resources Information Center

    Babich, Harvey; And Others

    1980-01-01

    This article is the first of three articles in a series on the acid rain problem in recent years. Discussed are the causes of acid precipitation and its consequences for the abiotic and biotic components of the terrestrial and aquatic ecosystems, and for man-made materials. (Author/SA)

  2. Acid precipitation in southeastern Wyoming

    SciTech Connect

    Ahern, J.; Baird, C.

    1983-09-01

    Snowfall, snowpack, and rainfall samples were collected in Laramie, Wyoming and in the Snowy Range west of Laramie from March to June 1981 to determine the occurrence and sources of acid precipitation in southeast Wyoming. Electrodes measured different pH values in the samples; however, fast-response electrodes yielded higher and apparently more accurate pH measurements. The pH values in the Laramie precipitation and snowpack were typically greater than 5.0, but all the Snowy Range snowpack pH values were less than 5.0. The lower pH values in the Snowy Range snowpack were caused by higher concentrations of the acid-forming nitrate and lower concentrations of the neutralizing calcium. Two organic species, formate and acetate, were detected in the Laramie samples, but had no significant influence on the acidity of the samples. 33 references, 3 figures, 17 tables.

  3. Universal sample preparation method integrating trichloroacetic acid/acetone precipitation with phenol extraction for crop proteomic analysis.

    PubMed

    Wu, Xiaolin; Xiong, Erhui; Wang, Wei; Scali, Monica; Cresti, Mauro

    2014-02-01

    Crop plants contain large amounts of secondary compounds that interfere with protein extraction and gel-based proteomic analysis. Thus, a protein extraction protocol that can be easily applied to various crop materials with minimal optimization is essential. Here we describe a universal protocol for total protein extraction involving trichloroacetic acid (TCA)/acetone precipitation followed by SDS and phenol extraction. Through SDS extraction, the proteins precipitated by the TCA/acetone treatment can be fully resolubilized and then further purified by phenol extraction. This protocol combines TCA/acetone precipitation, which aggressively removes nonprotein compounds, and phenol extraction, which selectively dissolves proteins, resulting in effective purification of proteins from crop tissues. This protocol can also produce high-quality protein preparations from various recalcitrant tissues, and therefore it has a wide range of applications in crop proteomic analysis. Designed to run on a small scale, this protocol can be completed within 5 h.

  4. Acid precipitation; an annotated bibliography

    USGS Publications Warehouse

    Wiltshire, Denise A.; Evans, Margaret L.

    1984-01-01

    This collection of 1660 bibliographies references on the causes and environmental effects of acidic atmospheric deposition was compiled from computerized literature searches of earth-science and chemistry data bases. Categories of information are (1) atmospheric chemistry (gases and aerosols), (2) precipitation chemistry, (3) transport and deposition (wet and dry), (4) aquatic environments (biological and hydrological), (5) terrestrial environments, (6) effects on materials and structures, (7) air and precipitation monitoring and data collection, and (8) modeling studies. References date from the late 1800 's through December 1981. The bibliography includes short summaries of most documents. Omitted are unpublished manuscripts, publications in press, master 's theses and doctoral dissertations, newspaper articles, and book reviews. Coauthors and subject indexes are included. (USGS)

  5. Contribution of the tricarboxylic acid (TCA) cycle and the glyoxylate shunt in Saccharomyces cerevisiae to succinic acid production during dough fermentation.

    PubMed

    Rezaei, Mohammad N; Aslankoohi, Elham; Verstrepen, Kevin J; Courtin, Christophe M

    2015-07-02

    Succinic acid produced by yeast during bread dough fermentation can significantly affect the rheological properties of the dough. By introducing mutations in the model S288C yeast strain, we show that the oxidative pathway of the TCA cycle and the glyoxylate shunt contribute significantly to succinic acid production during dough fermentation. More specifically, deletion of ACO1 and double deletion of ACO1 and ICL1 resulted in a 36 and 77% decrease in succinic acid levels in fermented dough, respectively. Similarly, double deletion of IDH1 and IDP1 decreased succinic acid production by 85%, while also affecting the fermentation rate. By contrast, double deletion of SDH1 and SDH2 resulted in a two-fold higher succinic acid accumulation compared to the wild-type. Deletion of fumarate reductase activity (FRD1 and OSM1) in the reductive pathway of the TCA cycle did not affect the fermentation rate and succinic acid production. The changes in the levels of succinic acid produced by mutants Δidh1Δidp1 (low level) and Δsdh1Δsdh2 (high level) in fermented dough only resulted in small pH differences, reflecting the buffering capacity of dough at a pH of around 5.1. Moreover, Rheofermentometer analysis using these mutants revealed no difference in maximum dough height and gas retention capacity with the dough prepared with S288C. The impact of the changed succinic acid profile on the organoleptic or antimicrobial properties of bread remains to be demonstrated.

  6. Acid Precipitation and the Forest Ecosystem

    ERIC Educational Resources Information Center

    Dochinger, Leon S.; Seliga, Thomas A.

    1975-01-01

    The First International Symposium on Acid Precipitation and the Forest Ecosystem dealt with the potential magnitude of the global effects of acid precipitation on aquatic ecosystems, forest soils, and forest vegetation. The problem is discussed in the light of atmospheric chemistry, transport, and precipitation. (Author/BT)

  7. Cofactor Balance by Nicotinamide Nucleotide Transhydrogenase (NNT) Coordinates Reductive Carboxylation and Glucose Catabolism in the Tricarboxylic Acid (TCA) Cycle*♦

    PubMed Central

    Gameiro, Paulo A.; Laviolette, Laura A.; Kelleher, Joanne K.; Iliopoulos, Othon; Stephanopoulos, Gregory

    2013-01-01

    Cancer and proliferating cells exhibit an increased demand for glutamine-derived carbons to support anabolic processes. In addition, reductive carboxylation of α-ketoglutarate by isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) was recently shown to be a major source of citrate synthesis from glutamine. The role of NAD(P)H/NAD(P)+ cofactors in coordinating glucose and glutamine utilization in the tricarboxylic acid (TCA) cycle is not well understood, with the source(s) of NADPH for the reductive carboxylation reaction remaining unexplored. Nicotinamide nucleotide transhydrogenase (NNT) is a mitochondrial enzyme that transfers reducing equivalents from NADH to NADPH. Here, we show that knockdown of NNT inhibits the contribution of glutamine to the TCA cycle and activates glucose catabolism in SkMel5 melanoma cells. The increase in glucose oxidation partially occurred through pyruvate carboxylase and rendered NNT knockdown cells more sensitive to glucose deprivation. Importantly, knocking down NNT inhibits reductive carboxylation in SkMel5 and 786-O renal carcinoma cells. Overexpression of NNT is sufficient to stimulate glutamine oxidation and reductive carboxylation, whereas it inhibits glucose catabolism in the TCA cycle. These observations are supported by an impairment of the NAD(P)H/NAD(P)+ ratios. Our findings underscore the role of NNT in regulating central carbon metabolism via redox balance, calling for other mechanisms that coordinate substrate preference to maintain a functional TCA cycle. PMID:23504317

  8. Systematic engineering of TCA cycle for optimal production of a four-carbon platform chemical 4-hydroxybutyric acid in Escherichia coli.

    PubMed

    Choi, Sol; Kim, Hyun Uk; Kim, Tae Yong; Lee, Sang Yup

    2016-11-01

    To address climate change and environmental problems, it is becoming increasingly important to establish biorefineries for the production of chemicals from renewable non-food biomass. Here we report the development of Escherichia coli strains capable of overproducing a four-carbon platform chemical 4-hybroxybutyric acid (4-HB). Because 4-HB production is significantly affected by aeration level, genome-scale metabolic model-based engineering strategies were designed under aerobic and microaerobic conditions with emphasis on oxidative/reductive TCA branches and glyoxylate shunt. Several different metabolic engineering strategies were employed to develop strains suitable for fermentation both under aerobic and microaerobic conditions. It was found that microaerobic condition was more efficient than aerobic condition in achieving higher titer and productivity of 4-HB. The final engineered strain produced 103.4g/L of 4-HB by microaerobic fed-batch fermentation using glycerol. The aeration-dependent optimization strategy of TCA cycle will be useful for developing microbial strains producing other reduced derivative chemicals of TCA cycle intermediates.

  9. Optimal Concentration of 2,2,2-Trichloroacetic Acid for Protein Precipitation Based on Response Surface Methodology

    PubMed Central

    Ngo, Albert N; Ezoulin, Miezan JM; Youm, Ibrahima; Youan, Bi-Botti C

    2014-01-01

    For low protein concentrations containing biological samples (in proteomics) and for non proteinaceous compound assays (in bioanalysis), there is a critical need for a simple, fast, and cost-effective protein enrichment or precipitation method. However, 2,2,2-trichloroacetic acid (TCA) is traditionally used for protein precipitation at ineffective concentrations for very low protein containing samples. It is hypothesized that response surface methodology, can be used to systematically identify the optimal TCA concentration for protein precipitation in a wider concentration range. To test this hypothesis, a central composite design is used to assess the effects of two factors (X1 = volume of aqueous solution of protein, and X2 = volume of TCA solution 6.1N) on the optical absorbance of the supernatant (Y1), and the percentage of protein precipitated (Y2). Using either bovine serum albumin (BSA) as a model protein or human urine (with 20 ppm protein content), 4% w/v (a saddle point) is the optimal concentration of the TCA solution for protein precipitation that is visualized by SDS-PAGE analysis. At this optimal concentration, the Y2-values range from 76.26 to 92.67% w/w for 0.016 to 2 mg/mL of BSA solution. It is also useful for protein enrichment and xenobiotic analysis in protein-free supernatant as applied to tenofovir (a model HIV microbicide). In these conditions, the limit of detection and limit of quantitation of tenofovir are respectively 0.0014 mg/mL and 0.0042 mg/mL. This optimal concentration of TCA provides optimal condition for protein purification and analysis of any xenobiotic compound like tenofovir. PMID:25750762

  10. Effects of a dietary ketone ester on hippocampal glycolytic and TCA cycle intermediates and amino acids in a 3xTgAD mouse model of Alzheimer's disease.

    PubMed

    Pawlosky, Robert J; Kemper, Martin F; Kashiwaya, Yoshihero; King, M Todd; Mattson, Mark P; Veech, Richard L

    2017-01-18

    In patients with Alzheimer's disease (AD) and in a triple transgenic (3xTgAD) mouse model of AD low glucose metabolism in the brain precedes loss of memory and cognitive decline. The metabolism of ketones in the brain by-passes glycolysis and therefore may correct several deficiencies that are associated with glucose hypometabolism. A dietary supplement composed of an ester of D-β-hydroxybutyrate and R-1,3 butane diol referred to as ketone ester (KE) was incorporated into a rodent diet and fed to 3xTgAD mice for 8 months. At 16.5 months of age animals were euthanized and brains dissected. Analyses were carried out on the hippocampus and frontal cortex for glycolytic and TCA (Tricarboxylic Acid) cycle intermediates, amino acids, oxidized lipids and proteins, and enzymes. There were higher concentrations of D-β-hydroxybutyrate in the hippocampus of KE-fed mice where there were also higher concentrations of TCA cycle and glycolytic intermediates and the energy-linked biomarker, n-acetyl aspartate compared to controls. In the hippocampi of control-fed animals the free mitochondrial [NAD(+) ]/[NADH] ratio were highly oxidized, whereas, in KE-fed animals the mitochondria were reduced. Also, the levels of oxidized protein and lipids were lower and the energy of ATP hydrolysis was greater compared to controls. 3xTgAD mice maintained on a KE-supplemented diet had higher concentrations of glycolytic and TCA cycle metabolites, a more reduced mitochondrial redox potential, and lower amounts of oxidized lipids and proteins in their hippocampi compared to controls. The KE offers a potential therapy to counter fundamental metabolic deficits common to patients and transgenic models. This article is protected by copyright. All rights reserved.

  11. Effects of acid precipitation on Daphnia magna

    SciTech Connect

    Parent, S.; Cheetham, R.D.

    1980-08-01

    Pollutants derived from fossil fuel combustion and precipitated from the atmosphere have substantially increased in the past decades. These materials, precipitated in such industrialized areas as southeastern Canada, have caused considerable alterations in aquatic ecosystems. Precipitation over most of the eastern United States is presently 10 to 500 times more acidic than is natural. Most affected aquatic ecosystems contain oligotrophic waters in regions of thin poorly buffered soils. Zooplankton are an important link in food chains of aquatic ecosystems and their disappearance or decline could drastically affect trophic relationships. Declines in zooplankton density in response to acid precipitation have been reported and short term survival of Daphnia pulex between pH 4.3 and 10.4; however, its potential for reproduction was limited to a fairly narrow range. Anderson (1944) noted the advantages of using daphnia as test organisms, and concluded that Daphnia magna was representative of other abundant zooplankton in sensitivity to toxic substances.

  12. Biologically produced acid precipitable polymeric lignin

    DOEpatents

    Crawford, Don L.; Pometto, III, Anthony L.

    1984-01-01

    A water soluble, acid precipitable polymeric degraded lignin (APPL), having a molecular weight of at least 12,000 daltons, and comprising, by percentage of total weight, at least three times the number of phenolic hydroxyl groups and carboxylic acid groups present in native lignin. The APPL may be modified by chemical oxidation and reduction to increase its phenolic hydroxyl content and reduce the number of its antioxidant inhibitory side chains, thereby improving antioxidant properties.

  13. NAPAP (National Acid Precipitation Assessment Program) results on acid rain

    SciTech Connect

    Not Available

    1990-06-01

    The National Acid Precipitation Assessment Program (NAPAP) was mandated by Congress in 1980 to study the effects of acid rain. The results of 10 years of research on the effect of acid deposition and ozone on forests, particularly high elevation spruce and fir, southern pines, eastern hardwoods and western conifers, will be published this year.

  14. Acid precipitation. (Latest citations from the Compendex database). Published Search

    SciTech Connect

    Not Available

    1993-06-01

    The bibliography contains citations concerning the causes, effects, sources, and controls of acid precipitation and acidification. Techniques and technology for measurement and analysis of acid precipitation are considered. (Contains 250 citations and includes a subject term index and title list.)

  15. Acid precipitation. (Latest citations from Pollution Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-09-01

    The bibliography contains citations concerning the research of acid precipitation, and the resultant acidification of land and water. Topics include composition, causes, effects, sources, measurements, and controls of acid precipitation. Worldwide geographical distribution of acid precipitation and acidification are covered. (Contains 250 citations and includes a subject term index and title list.)

  16. Acid precipitation. (Latest citations from Pollution abstracts). Published Search

    SciTech Connect

    Not Available

    1994-03-01

    The bibliography contains citations concerning the research of acid precipitation, and the resultant acidification of land and water. Topics include composition, causes, effects, sources, measurements, and controls of acid precipitation. Worldwide geographical distribution of acid precipitation and acidification are covered. (Contains 250 citations and includes a subject term index and title list.)

  17. A mutation in the E2 subunit of the mitochondrial pyruvate dehydrogenase complex in Arabidopsis reduces plant organ size and enhances the accumulation of amino acids and intermediate products of the TCA cycle.

    PubMed

    Yu, Hailan; Du, Xiaoqiu; Zhang, Fengxia; Zhang, Fang; Hu, Yong; Liu, Shichang; Jiang, Xiangning; Wang, Guodong; Liu, Dong

    2012-08-01

    The mitochondrial pyruvate dehydrogenase complex (mtPDC) plays a pivotal role in controlling the entry of carbon into the tricarboxylic acid (TCA) cycle for energy production. This multi-enzyme complex consists of three components: E1, E2, and E3. In Arabidopsis, there are three genes, mtE2-1, mtE2-2, and mtE2-3, which encode the putative mtPDC E2 subunit but how each of them contributes to the total mtPDC activity remains unknown. In this work, we characterized an Arabidopsis mutant, m132, that has abnormal small organs. Molecular cloning indicated that the phenotype of m132 is caused by a mutation in the mtE2-1 gene, which results in a truncation of 109 amino acids at the C-terminus of the encoded protein. In m132, mtPDC activity is only 30% of the WT and ATP production is severely impaired. The mutation in the mtE2-1 gene also leads to the over-accumulation of most intermediate products of the TCA cycle and of all the amino acids for protein synthesis. Our results suggest that, among the three mtE2 genes, mtE2-1 is a major contributor to the function of Arabidopsis mtPDC and that the functional disruption of mtE2-1 profoundly affects plant growth and development, as well as its metabolism.

  18. Acid Precipitation Awareness Curriculum Materials in the Life Sciences.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.

    1983-01-01

    Provides an outline of course content for acid precipitation and two acid rain activities (introduction to pH and effects of acid rain on an organism). Information for obtaining 20 additional activities as well as an information packet containing booklets, pamphlets, and articles are also provided. (JN)

  19. Acid Precipitation in the Pacific Northwest.

    ERIC Educational Resources Information Center

    Baldwin, John; Kozak, David

    1988-01-01

    Discusses the causes, sources, and problems associated with acid deposition in the Pacific Northwest. Includes a learning activity about acid rain, "Deadly Skies," which was adapted from the Project WILD Aquatic Supplement. (TW)

  20. Effects of acid precipitation on crops

    SciTech Connect

    Lee, J.J.

    1981-01-01

    The effects of acid rain on crop yield have been studied using field-grown and potted plants. Results have shown that the chemicals in acid rain can affect crop growth and yield at ambient concentrations. For many crops, the dose-response curve probably has at least one peak and crossover point from stimulatory to inhibitory response may depend on other environmental factors. Plant parts often are affected differently, suggesting that acid rain can change the allocation of energy within plants. Available experimental results are not transferable to agricultural situations. The characteristics of acid rain which have the greatest influence on crop yield have not been determined. Interactions between acid rain and other environmental factors have scarcely been studied. Before a believable assessment of the economic impact of acid rain on crops can be done, the mechanisms of response have to be studied and the predictive capability enhanced and validated.

  1. Acid Precipitation: Scientific Progress and Public Awareness.

    ERIC Educational Resources Information Center

    Cowling, Ellis B.

    1983-01-01

    Describes certain perspectives on scientific research and on the public debates about acid deposition and its effects. Although primary attention is given to European/North American research, the ideas developed are relevant in any world region sensitive to acid deposition resulting from intense industrialization. (Author/JN)

  2. Acid precipitation. (Latest citations from the Aerospace database). Published Search

    SciTech Connect

    Not Available

    1993-12-01

    The bibliography contains citations concerning the measurement and analysis of acid rain and acidification of areas by precipitation. Both global and regionalized areas of acid rain effects are examined. Control techniques applicable to the sources and causes are discussed. (Contains a minimum of 187 citations and includes a subject term index and title list.)

  3. Effects of acidic precipitation on field crops

    SciTech Connect

    Evans, L.S.; Hendrey, G.R.; Lewin, K.F.; Gmur, N.F.

    1982-02-01

    The effects of acid rain on yields of field-grown soybeans has been investigated. Plants exposed to simulated rainfalls of pH 4.1, 3,3 and 2.7 had decreased seed yields of 10.6, 16.8 and 23.9% below yields of plants exposed to simulated rainfalls of pH 5.6. (ACR)

  4. Acid precipitation at 3 sites in the Klang Valley, Malaysia

    SciTech Connect

    Philip, E.; Yap, S.K.; Azimi, S.

    1996-12-31

    A study which examined spatial variation, dust and chemical composition factors associated with precipitation pH in the Klang Valley had been conducted. Precipitation samples were collected on a monthly basis at 3 different locations during the periods of 1993-1995. These long term sites were situated at varying distance from the industrial zone of the Klang Valley. Data were collected on a monthly basis and where possible after every rainfall. This included the field pH, electrical conductivity (EC) and analysis of chemical components. To date, the general pH trend at these stations is decreasing towards the acid range. The site furthest from the industrial zone had the highest pH values while site closest to the industrial zone had the lowest pH. There appeared to be a correlation between the precipitation pH and electrical conductivity (EC), the EC readings increased with increased acidity. Variations in precipitation pH was closely associated with the changes in sulfate concentration. The pH of precipitation is determined not only by the anions, but also by the concentration of cations in the atmosphere which neutralized the acidity by forming salts. The main cause for the decrease in the pH values is the significant increase of acidic components and decrease of soil-oriented components (Mg and Ca) in the rain water.

  5. Acid precipitation chemistry in an urban plume

    SciTech Connect

    Saxena, P.; Arcado, T.D.; Marler, B.L.; Altshuler, S.L. )

    1987-01-01

    In this paper the authors present the results of an ongoing study performed by the Pacific Gas and Electric Company (PGandE) to: investigate the formation, transport and deposition of acidic species in the urban plume from the San Francisco Bay Area (SFBA) and assess the role of two gas-fired electric generation facilities located on the eastern boundary of the SFBA. They present a brief summary of their study area's climate. The network used in this study and our experimental methods are also described. An analysis of wet deposition data collected by our network is presented along with a discussion of the major findings, to date, of our study.

  6. Precipitation of sodium acid urate from electrolyte solutions

    NASA Astrophysics Data System (ADS)

    Füredi-Milhofer, Helga; Babić-Ivaniĉić, Vesna; Milat, Ognjen; Brown, Walter E.; Gregory, Thomas M.

    1987-07-01

    The precipitation of soduim urate from solutions containing uric acid, soduim hydroxide, hydrochloric acid, sodium chloride and water was investigated at constant pH (7.5±0.1) and temperature (308 K). Precipitates were observed by lights and electron microscopy and characterized by electron and X-ray diffraction. The results are presented in the form of "precipitation" and "chemical potential" diagrams, the latter giving the soduim-to-urate molar ratios of the precipitates. Two types of precipitation boundaries were observed, both of which had indicated soduim-to-urate moral ratios of 1:1. The ion activity product, (Na +)(HU -), associated with boundary I was AP I=(4.8±1.1)×10 -5 and with boundary II was with boundary II was AP II=(6.5±0.4)×10 -4. The supersaturation, S, at boundary II was S=AP II/ Ksp=12.3, in which Ksp is the solubility product of soduim acid urate monohydrate. The latter precipitated as well-formed crystals at supersaturations of 12.3 and above. The ion activity product associated with boundary I is approximately equal to the solubility product of soduim acid urate monohydrate. Small amounts of several morphologically different sodium urate crystals formed in the range of supersaturations (1≤ S≤12.3). Crystals formed in this range may include the monohydrate of sodium acid urate and possibly a higher hydrate. The findings have relevance to pathological renal stone formation and gouty arthritis.

  7. Compositions and method for controlling precipitation when acidizing sour wells

    SciTech Connect

    Dill, W.R.; Walker, M.L.

    1989-12-19

    This patent describes an acidizing composition for treating a sour well. It comprises: a base acid solution having an initial ph below 1.9; an iron sequestering agent to combine with iron present in the solution comprising at least one compound selected from the group consisting of aminopolycarboxylic acids, hydroxycarboxylic acids, cyclic polyethers and derivatives of the acids and ethers present in an amount of from about 0.25 to about 5 percent by weight of the acid solution; and a sulfide modifier to combine with sulfides present in the solution comprising at least one member selected from the group consisting of an aldehyde, acetal, hemiacetal and any other compound capable of forming an aldehyde in solution, present in an amount of from about 1 to about 4 percent by weight of the acid solution, whereby precipitation of ferric hydroxide, ferrous sulfide and elemental sulfur is inhibited as acid spending occurs.

  8. Acidic precipitation: considerations for an air-quality standard

    SciTech Connect

    Evans, L.S.; Hendrey, G.R.; Stensland, G.J.; Johnson, D.W.; Francis, A.J.

    1980-01-01

    Acidic precipitation, wet or frozen deposition with a hydrogen ion concentration greatern than 2.5 ..mu..eq l/sup -1/ is a significant air pollution problem in the United States. The chief anions accounting for the hydrogen ions in rainfall are nitrate and sulfate. Agricultural systems are more likely to derive net nutritional benefits from increasing inputs of acidic rain than are forest systems when soils alone are considered. Agricultural soils may benefit because of the high N and S requirements of agricultural plants. Detrimental effects to forest soils may result if atmospheric H/sup +/ inputs significantly add to or exceed H/sup +/ production by soils. Acidification of fresh waters of southern Scandinavia, southwestern Scotland, southeastern Canada, and northeastern United States is caused by acid deposition. Areas of these regions in which this acidification occurs have in common, highly acidic precipitation with volume weighted mean annual H/sup +/ concentrations of 25 ..mu..eq l/sup -1/ or higher and slow weathering granitic or precambrian bedrock with thin soils deficient in minerals which would provide buffer capacity. Biological effects of acidification of fresh waters are detectable below pH 6.0. As lake and stream pH levels decrease below pH. 6.0, many species of plants, invertebrates, and vertebrates are progressively eliminated. Generally, fisheries are impacted below pH 5.0 and are completely destroyed below pH 4.8. There are few studies that document effects of acidic precipitation on terrestrial vegetation to establish an air quality standard. It must be demonstrated that current levels of precipitation acidity alone significantly injure terrestrial vegetation. In terms of documented damanges, current research indicates that establishing a standard for precipitation for the volume weighted annual H/sup +/ concentration at 25 ..mu..eq l/sup -1/ may protect the most sensitive areas from permanent lake acidification.

  9. Teacher's Resource Guide on Acidic Precipitation with Laboratory Activities.

    ERIC Educational Resources Information Center

    Barrow, Lloyd H.

    The purpose of this teacher's resource guide is to help science teachers incorporate the topic of acidic precipitation into their curricula. A survey of recent junior high school science textbooks found a maximum of one paragraph devoted to the subject; in addition, none of these books had any related laboratory activities. It was on the basis of…

  10. Acidic precipitation, Vol. 2: Biological and ecological effects

    SciTech Connect

    Adriano, D.C.; Johnson, A.H.

    1989-01-01

    Acidic precipitation has its origin in emissions to the atmosphere of numerous compounds from both natural and man-made sources. The chapters in this volume cover a wide array of topics on the biological and ecological effects of acidic precipitation. A chapter on soil productivity emphasizes changes in biological and chemical characters of forest soils impacted by acidic deposition. Additional chapters discuss specific effects on soil microorganisms, trees, and crops. The importance of aluminum in this environmental issue is highlighted by a discussion on the mobility and phytotoxicity of this element in acidic soils. This chapter puts into perspective the biology of Al stressed plants. Two major chapters discuss the effect of acidic precipitation on forest ecosystems; one emphasizing North America, and the other Europe. Effects of soil acidification on key soil processes, including litter decomposition and depletion of essential plant nutrients in the soil profile are emphasized. Finally, three major chapters comprehensively cover limnological ecosystems and their response to acidic perturbation. These chapters discuss the response of stream and lake communities, both floral and faunal, to water acidification, including reduced biodiversity in these systems. Ten chapters have been processed separately for inclusion in the appropriate data bases.

  11. HF acid blends based on formation conditions eliminate precipitation problems

    SciTech Connect

    Gdanski, R.; Shuchart, C.

    1997-03-01

    Formulating HCl-HF acid blends based on the mineralogy and temperature of a formation can increase the success of hydrofluoric acid (HF) treatments. Sodium and potassium in the structures of formation minerals can cause precipitation and matrix plugging problems during acidizing. Slight modifications of the acid blend used in the treatment can help eliminate fluosilicate precipitation. Researchers recently conducted tests to determine how acid blends react in different formations under varying temperatures. The results of the tests indicate that the minimum HCl:HF ratio in an acid blend is 6-to-1, and the optimum ratio is 9-to-1. Regular mud acid (12% HCl-3% HF) has been used successfully for years to enhance production in sandstone formations. By the 1980s, operators began to vary the concentration of HF and HCl acids to solve excessive sanding problems in sandstone. The paper discusses treatment problems, formation characteristics, alumino-silicate scaling, research results, brine compatibility, optimum treatment, and acid volume guidelines.

  12. Dysfunctional TCA-Cycle Metabolism in Glutamate Dehydrogenase Deficient Astrocytes.

    PubMed

    Nissen, Jakob D; Pajęcka, Kamilla; Stridh, Malin H; Skytt, Dorte M; Waagepetersen, Helle S

    2015-12-01

    Astrocytes take up glutamate in the synaptic area subsequent to glutamatergic transmission by the aid of high affinity glutamate transporters. Glutamate is converted to glutamine or metabolized to support intermediary metabolism and energy production. Glutamate dehydrogenase (GDH) and aspartate aminotransferase (AAT) catalyze the reversible reaction between glutamate and α-ketoglutarate, which is the initial step for glutamate to enter TCA cycle metabolism. In contrast to GDH, AAT requires a concomitant interconversion of oxaloacetate and aspartate. We have investigated the role of GDH in astrocyte glutamate and glucose metabolism employing siRNA mediated knock down (KD) of GDH in cultured astrocytes using stable and radioactive isotopes for metabolic mapping. An increased level of aspartate was observed upon exposure to [U-(13) C]glutamate in astrocytes exhibiting reduced GDH activity. (13) C Labeling of aspartate and TCA cycle intermediates confirmed that the increased amount of aspartate is associated with elevated TCA cycle flux from α-ketoglutarate to oxaloacetate, i.e. truncated TCA cycle. (13) C Glucose metabolism was elevated in GDH deficient astrocytes as observed by increased de novo synthesis of aspartate via pyruvate carboxylation. In the absence of glucose, lactate production from glutamate via malic enzyme was lower in GDH deficient astrocytes. In conclusions, our studies reveal that metabolism via GDH serves an important anaplerotic role by adding net carbon to the TCA cycle. A reduction in GDH activity seems to cause the astrocytes to up-regulate activity in pathways involved in maintaining the amount of TCA cycle intermediates such as pyruvate carboxylation as well as utilization of alternate substrates such as branched chain amino acids.

  13. Impact of effects of acid precipitation on toxicity of metals.

    PubMed Central

    Nordberg, G F; Goyer, R A; Clarkson, T W

    1985-01-01

    Acid precipitation may increase human exposure to several potentially toxic metals by increasing metal concentrations in major pathways to man, particularly food and water, and in some instances by enhancing the conversion of metal species to more toxic forms. Human exposures to methylmercury are almost entirely by way of consumption of fish and seafood. In some countries, intakes by this route may approach the levels that can give rise to adverse health effects for population groups with a high consumption of these food items. A possible increase in methylmercury concentrations in fish from lakes affected by acid precipitation may thus be of concern to selected population groups. Human exposures to lead reach levels that are near those associated with adverse health effects in certain sensitive segments of the general population in several countries. The possibility exists that increased exposures to lead may be caused by acid precipitation through a mobilization of lead from soils into crops. A route of exposure to lead that may possibly be influenced by acid precipitation is an increased deterioration of surface materials containing lead and a subsequent ingestion by small children. A similar situation with regard to uptake from food exists for cadmium (at least in some countries). Human metal exposures via drinking water may be increased by acid precipitation. Decreasing pH increases corrosiveness of water enhancing the mobilization of metal salts from soil; metallic compounds may be mobilized from minerals, which may eventually reach drinking water. Also, the dissolution of metals (Pb, Cd, Cu) from piping systems for drinking water by soft acidic waters of high corrosivity may increase metal concentrations in drinking water. Exposures have occasionally reached concentrations which are in the range where adverse health effects may be expected in otherwise healthy persons. Dissolution from piping systems can be prevented by neutralizing the water before

  14. Ten-year study on acid precipitation nears conclusion

    SciTech Connect

    Olem, H. )

    1990-04-01

    Results from the National Acid Precipitation Assessment Program (NAPAP) are discussed. Final results are contained in 26 state of the science reports. Seven of the reports provide information on acid rain and aquatic ecosystems. They describe the current state of acidic surface waters, watershed processes affecting surface water chemistry, historical evidence for surface water acidification, methods for forecasting future changes, and the response of acidic surface water to liming. Six areas of the country were found to be of special interest: southwest Adirondacks, New England, forested areas of the mid-Atlantic highlands, the Atlantic coastal plain, the northern Florida highlands, parts of northeastern Wisconsin and the Upper Peninsula of Michigan. Environmental effects, mitigation efforts and possible legislation are briefly discussed.

  15. Natural acidity of waters in podzolized soils and potential impacts from acid precipitation

    SciTech Connect

    Stednick, J.D.; Johnson, D.W.

    1982-01-01

    Nutrient movements through sites in southeast Alaska and Washington were documented to determine net changes in chemical composition of precipitation water as it passed through a forest soil and became stream-flow. These sites were not subject to acid precipitation (rainfall pH 5.8 to 7.2), yet soil water was acidified to 4.2 by natural organic acid-forming processes in the podzol soils. Organic acids precipitated in the subsoils, allowing a pH increase. Streamwater pH ranged from 6.5 to 7.2 indicating a natural buffering capacity that may exceed any additional acid input from acid rain. Precipitation composition was dominated by calcium, magnesium, sodium, and chloride due to the proximity of the ocean at the southeast Alaska site. Anionic constituents of the precipitation were dominated by bicarbonate at the Washington site. Soil podzolization processes concurrently increased solution color and iron concentrations in the litter and surface horizons leachates. The anion flux through the soil profile was dominated by chloride and sulfate at the southeast Alaska site, whereas at the Washington site anion flux appeared to be dominated by organic acids. Electroneutrality calculations indicated a cation deficit for the southeast Alaska site.

  16. Natural acidity of waters in podzolized soils and potential impacts from acid precipitation

    SciTech Connect

    Stednick, J.D.; Johnson, D.W.

    1982-01-01

    Nutrient movements through sites in southeast Alaska and Washington were documented to determine net changes in chemical composition of precipitation water as it passed through a forest soil and became stream flow. These sites were not subject to acid precipitation (rainfall pH 5.8 to 7.2), yet soil water was acidified to 4.2 by natural organic acid forming processes in the podzol soils. Organic acids precipitated in the subsoils, allowing a pH increase. Stream water pH ranged from 6.5 to 7.2 indicating a natural buffering capacity that may exceed any additional acid input from acid rain. Precipitation composition was dominated by magnesium, sodium, and chloride due to the proximity of the ocean at the southeast Alaska site. Anionic constituents of the precipitation were dominated by bicarbonate at the Washington site. Soil podzolization processes concurrently increased solution color and iron concentrations in the litter and surface horizons leachates. The anion flux through the soil profile was dominated by chloride and sulfate at the southwast Alaska site, whereas at the Washington site anion flux appeared to be dominated by organic acids. Electroneutrality calculations indicated a cation deficit for the southeast Alaska site. 10 references, 2 tables.

  17. Precipitation of biomimetic fluorhydroxyapatite/polyacrylic acid nanostructures

    NASA Astrophysics Data System (ADS)

    Roche, Kevin J.; Stanton, Kenneth T.

    2015-01-01

    Ordered structures of fluorhydroxyapatite (FHA) nanoparticles that resemble the nanostructure of natural human enamel have been prepared. Wet precipitation in the presence of polyacrylic acid (PAA) was used, and the particle morphology was altered by varying several reaction conditions. High molecular weight PAA increased particle length from around 54 nm to several hundred nanometres, while maintaining particle width at 15 nm. PAA concentration and the order of mixing the reactants also influenced crystal morphology. Optimum conditions produced dense, aligned bundles of highly elongated nanorods, which are very similar to the hierarchical nanostructure of human tooth enamel.

  18. Induction of PDGF-B in TCA-treated epidermal keratinocytes.

    PubMed

    Yonei, Nozomi; Kanazawa, Nobuo; Ohtani, Toshio; Furukawa, Fukumi; Yamamoto, Yuki

    2007-11-01

    Trichloroacetic acid (TCA) is one of the most widely used peeling agents, and induces full necrosis of the whole epidermis, followed by reconstitution of the epidermis and the matrix of the papillary dermis. The cytotoxic effects of TCA, such as suppressing proliferation of keratinocytes and fibroblasts and protein synthesis by fibroblasts, have already been reported. However, the entire biological mechanism responsible for TCA peeling has yet to be determined. Hypothetical activation effects of TCA treatment on epidermal cells to induce production of growth factors and cytokines are examined, and are compared with its cytotoxic effects in terms of time course and applied TCA concentrations. After various periods of incubation with TCA, viability of Pam212 murine keratinocytes was investigated with MTT assay and dye exclusion assay, and production of growth factors and cytokines with reverse transcription-polymerase chain reaction (RT-PCR). Changes in platelet-derived growth factor (PDGF)-B mRNA expression and protein production in the human skin specimens after TCA application were then examined by RT-PCR and immunohistochemistry, respectively. Incubation with TCA showed cytotoxicity and induced death of Pam212 cells, depending on the incubation period and the TCA concentration. In addition, expressions of PDGF-B, tumor growth factor (TGF)-alpha, TGF- beta1 and vascular endothelial growth factor, which are the growth factors reportedly secreted from keratinocytes during wound healing, were all detected in Pam212 cells after short-term treatment with TCA. Expressions of inflammatory cytokines such as interleukin (IL)-1 and IL-10 were also induced. In TCA-treated NIH-3T3 fibroblasts, in contrast, observed was upregulation of only keratinocyte growth factor, which is reportedly secreted from fibroblasts, as well as the similar cytotoxic effect. In human skin, PDGF-B mRNA expression became significantly upregulated after TCA application, and then immediately

  19. Impact of acid precipitation on recreation and tourism in Ontario: an overview

    SciTech Connect

    Not Available

    1984-01-01

    The impacts of acid precipitation on fishing opportunities, waterfowl and moose hunting, water contact activities, and the perception of the environment in Ontario are analyzed. Economic effects and future research needs are also estimated and discussed. These questions have been examined by identifying the likely links between acidic precipitation and recreation and tourism, by developing estimates of the importance of aquatic-based recreation and tourism, by describing the current and estimated future effects of acid precipitation. 101 references, 9 figures, 19 tables.

  20. Relationship between acid precipitation and three-dimensional transport associated with synoptic-scale cyclones

    SciTech Connect

    Haagenson, P.L.; Lazrus, A.L.; Kuo, Y.H.; Caldwell, G.A.

    1985-09-01

    Field data collected during APEX (Acid Precipitation Experiment) are used in combination with an isentropic trajectory model to analyze the relationship between acid precipitation and three-dimensional transport associated with cyclonic storms. Data are presented which indicate that high acidity in precipitation is often associated with slow transport speed and elevated SO2 concentrations in the dry air feeding into the precipitating regions. Conversely, low acidity is usually related to rapid transit, descending motion, and transport above the atmospheric boundary layer. The results also show that precipitation in the cold sector of a cyclone (in advance of the surface warm front) is often more acidic than that in other sectors of the storm. Four case studies are included to detail some of these meteorological effects. 19 references.

  1. PIE Nacelle Flow Analysis and TCA Inlet Flow Quality Assessment

    NASA Technical Reports Server (NTRS)

    Shieh, C. F.; Arslan, Alan; Sundaran, P.; Kim, Suk; Won, Mark J.

    1999-01-01

    This presentation includes three topics: (1) Analysis of isolated boattail drag; (2) Computation of Technology Concept Airplane (TCA)-installed nacelle effects on aerodynamic performance; and (3) Assessment of TCA inlet flow quality.

  2. Quantitative validation of different protein precipitation methods in proteome analysis of blood platelets.

    PubMed

    Zellner, Maria; Winkler, Wolfgang; Hayden, Hubert; Diestinger, Michael; Eliasen, Maja; Gesslbauer, Bernd; Miller, Ingrid; Chang, Martina; Kungl, Andreas; Roth, Erich; Oehler, Rudolf

    2005-06-01

    For the preparation of proteins for proteome analysis, precipitation is frequently used to concentrate proteins and to remove interfering compounds. Various methods for protein precipitation are applied, which rely on different chemical principles. This study compares the changes in the protein composition of human blood platelet extracts after precipitation with ethanol (EtOH) or trichloroacetic acid (TCA). Both methods yielded the same amount of proteins from the platelet preparations. However, the EtOH-precipitated samples had to be dialyzed because of the considerable salt content. To characterize single platelet proteins, samples were analyzed by two-dimensional fluorescence differential gel electrophoresis. More than 90% of all the spots were equally present in the EtOH- and TCA-precipitated samples. However, both precipitation methods showed a smaller correlation with nonprecipitated samples (EtOH 74.9%, TCA 79.2%). Several proteins were either reduced or relatively enriched in the precipitated samples. The proteins varied randomly in molecular weight and isoelectric point. This study shows that protein precipitation leads to specific changes in the protein composition of proteomics samples. This depends more on the specific structure of the protein than on the precipitating agent used in the experiment.

  3. Occurrence of acid precipitation on the West Coast of the United States

    SciTech Connect

    Powers, C.F.; Rambo, D.L.

    1981-01-01

    Compilation of published and unpublished data shows acid precipitation to be more widespread in the Pacific coastal states than is generally recognized. Although information is scattered and discontinuous, precipitation is definitely acidic in the Los Angeles Basin and north-central California and in the Puget Sound region in Washington. Acid-rain occurrences were observed in western and eastern Oregon, but data are inadequate for regional generalization. New stations currently being established in Washington and Oregon, largely in response to the recently renewed activity of Mount St. Helens, will greatly facilitate assessment of precipitation acidity in the Northwest.

  4. Caprylic acid precipitation method for impurity reduction: an alternative to conventional chromatography for monoclonal antibody purification.

    PubMed

    Brodsky, Yan; Zhang, Cheng; Yigzaw, Yinges; Vedantham, Ganesh

    2012-10-01

    We report the use of caprylic acid based impurity precipitation as (1) an alternative method to polishing chromatography techniques commonly used for monoclonal antibody purification and (2) an impurity reduction step prior to harvesting the bioreactor. This impurity reduction method was tested with protein A purified antibodies and with cell culture fluid. First, the operational parameters influencing precipitation of host cell proteins and high molecular weight aggregate in protein A pools were investigated. When used as a polishing step, the primary factor affecting purification and yield was determined to be pH. Caprylic acid precipitation was comparable to polishing IEX chromatography in reducing host cell protein and aggregate levels. A virus reduction study showed complete clearance of a model retrovirus during caprylic acid precipitation of protein A purified antibody. Caprylic acid mediated impurity precipitation in cell culture showed that the impurity clearance was generally insensitive to pH and caprylic acid concentration whereas yield was a function of caprylic acid concentration. Protein A purification of caprylic acid precipitated cell culture fluid generated less turbid product pool with reduced levels of host cell proteins and high molecular weight aggregate. The results of this study show caprylic acid precipitation to be an effective purification method that can be incorporated into a production facility with minimal cost as it utilizes existing tanks and process flow. Eliminating flow through chromatography polishing step can provide process intensification by avoiding the process tank volume constraints for high titer processes.

  5. Protein concentration by precipitation with pyrogallol red prior to electrophoresis.

    PubMed

    Marshall, T; Abbott, N J; Fox, P; Williams, K M

    1995-01-01

    The pyrogallol red protein assay (Clinical Chemistry 1986, 32, 1551-1554) is based upon formation of a blue protein-dye complex in the presence of molybdate under acidic conditions. However, centrifugation of the assay mixture results in loss of color yield and precipitation of the protein-dye complex which can be recovered and resolubilized to achieve protein concentration prior to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The method has been evaluated relative to trichloroacetic acid (TCA) precipitation for recovery and electrophoresis of commercial protein and peptide molecular weight markers. Precipitation with pyrogallol red-molybdate (PRM) gives better and more uniform recovery of both proteins and peptides as compared to TCA. The lower limit of PRM precipitation is similar to TCA and corresponds to 1 microgram protein per mL assay mixture. This is equivalent to 100 microL of 10 micrograms/mL protein using the standard protein assay or 1 microgram/mL protein using a modified assay incorporating a fivefold concentrate of the dye reagent. Application of the method is demonstrated by concentration of urinary proteins. The method is simple and economic and useful for conserving trace amounts of precious sample as it allows recovery of protein for electrophoresis following protein assay.

  6. The alpha-glycosidic bonds of poly(ADP-ribose) are acid-labile.

    PubMed

    Panzeter, P L; Zweifel, B; Althaus, F R

    1992-04-15

    The poly(ADP-ribosyl)ation system of higher eukaryotes produces multiple ADP-ribose polymers of distinct sizes which exhibit different binding affinities for histones. Although precipitation with trichloroacetic acid (TCA) is the standard procedure for isolation of poly(ADP-ribose) from biological material, we show here that poly(ADP-ribose) is not stable under acidic conditions. Storage of poly(ADP-ribose) as TCA pellets results in acid hydrolysis of polymers, the extent of which is dependent on storage time and temperature. The alpha-glycosidic, inter-residue bonds are the preferred sites of attack, thus reducing polymer sizes by integral numbers of ADP-ribose to yield artefactually more and smaller polymers than originally present. Therefore, poly(ADP-ribosyl)ation studies involving TCA precipitation, histone extraction with acids, or acidic incubations of ADP-ribose polymers must account for the impact of acids on resulting polymer populations.

  7. National Acid Precipitation Assessment Program: Acidic deposition: An inventory of non-Federal research, monitoring, and assessment information

    SciTech Connect

    Herrick, C.N.

    1990-01-01

    The Acid Precipitation Act of 1990 (Title VII of the Energy Security Act of 1980, P.L. 96-294) established the Interagency Task Force on Acid Precipitation to develop and implement the National Acid Precipitation Assessment Program (NAPAP). The information included in the document was provided to NAPAP's Task Group Leaders and State-of-Science and State-of-Technology authors in July 1989. The early release was intended to assure that the authors would be aware of the information at an early phase in the assessment production process.

  8. The annual course of TCA formation in the lower troposphere: a modeling study.

    PubMed

    Folberth, Gerd; Pfister, Gabriele; Baumgartner, Dietmar; Putz, Erich; Weissflog, Ludwig; Elansky, Nikolai P

    2003-01-01

    We present a modeling study investigating the influence of climate conditions and solar radiation intensity on gas-phase trichloroacetic acid (TCA) formation. As part of the ECCA-project (Ecotoxicological Risk in the Caspian Catchment Area), this modeling study uses climate data specific for the two individual climate regimes, namely "Kalmykia" and "Kola Peninsula". A third regime has also been included in this study, namely "Central Europe", which serves as a reference to somehow more moderate climate conditions. The simulations have been performed with a box modeling package (SBOX, photoRACM), which uses Regional Atmospheric Chemistry Mechanism (RACM) as its chemistry scheme. For this model a mechanism supplement has been developed including the reaction pathways of methyl chloroform photooxidation. The investigations are completed by a detailed sensitivity study addressing the impact of temperature and relative humidity. Atmospheric OH and HO2 concentrations and the NOx/HO2 ratio were identified as the governing quantities controlling the TCA formation trough methyl chloroform oxidation in the gas phase. Model calculations show a TCA production rate ranging between almost zero and 6.5 x 10(3) molecules cm(-3) day(-1) depending on location and season. In the Kalmykia regime the model predicts mean TCA production rates of 1.3 x 10(-4) and 5.4 x 10(-5) microg m(-3) year(-1) for the urban and rural environment, respectively. From the comparison of model calculations with measured TCA burdens in the soil ranging between 130 g m(-3) and 1750 g m(-3) we conclude that TCA formation through methyl chloroform photooxidation in the gas-phase is probably not the principal atmospheric TCA source in this region.

  9. Acid-Base and Precipitation Equilibria in Wine

    ERIC Educational Resources Information Center

    Palma, Miguel; Barroso, Carmelo G.

    2004-01-01

    Experiments are performed to establish the changes of pH during the precipitation of potassium hydrogen tartrate, with its unfavorable impact on the stability of wine. Students, thus, obtain a clearer understanding of the interplay between a variety of chemical equilibria within a single medium.

  10. Compositions and method for controlling precipitation when acidizing sour wells

    SciTech Connect

    Dill, W.R.; Walker, M.L.

    1990-08-21

    This patent describes a method of treating a sour well penetrating a subterranean formation. It comprises: introducing into the well a treating fluid comprising an acid solution having a pH below 1.9, an iron sequestering agent comprising at least one compound selected from the group consisting of aminopolycarboxylic acids, hydroxycarboxylic acids, cyclic polyethers and derivatives of the acids and ethers, present in an amount of from about 0.25 to about 5 percent by weight of the acid solution, and a sulfide modifier comprising at least one compound selected from the group consisting of an aldehyde, acetal, hemiacetal and any other compound capable of forming aldehydes in the acid solution, present in an amount of from about 0.25 to about 5 percent of the acid solution; and treating the subterranean formation with the treating fluid.

  11. Baseline Acidity of Ancient Precipitation from the South Pole,

    DTIC Science & Technology

    1984-06-01

    post-depositional diffusion of ait ferences ( Langway et al. 1975). The first three through the firn was contributing significantly to the measured...C.C. Langway , the Canadian high Arctic. Nature, 295: 137-140. Jr. (1975) Chemistry of 700 years of precipitation Kolthoff, i.M., E.B.Sandell...sis. London: Macmillian Company, p. 55. port 341. ADA 014970. Kuivinen, K.C., B.R. Koci, G.W. Holdsworth Cragin, J.H., M.M. Herron, C.C. Langway , Jr

  12. Considerations of an air-quality standard to protect terrestrial vegetation from acidic precipitation

    SciTech Connect

    Evans, L.S.

    1981-01-01

    Studies on the effects of acidic precipitation which is here defined as wet or frozen deposition with a hydrogen ion concentration greater than 2.5 ..mu..eq 1/sup -1/, are reviewed. At the present time there is an inadequate amount of information that shows decreases in crop growth except for one field study. Most studies with plants (crops and forests) are inadequate for standard setting because they are not conducted in the field with adequate randomization of plots coupled with rigorous statistical analyses. Although visible injury to foliage has been documented in a variety of greenhouse studies, no experimental evidence demonstrates loss of field crop value or reduction in plant productivity due to visible foliar injury. Acidic precipitation can contribute nutrients to vegetation and could also influence leaching rates of nutrients from vegetation. Although these processes occur, there are no data that show changes in nutrient levels in foliage that relate to crop or natural ecosystem productivity. Experimental results show that fertilization of ferns is inhibited by current levels of acidic precipitation in the northeastern United States. However, the overall impacts of inhibited fertilization on perpetuation of the species or ecosystem productivity have not been evaluated. Simulated acidic precipitation has been shown to effect plant pathogens in greenhouse and field experiments. Simulated acidic precipitation inhibited pathogen activities under some circumstances and promoted pathogen activities under other circumstances. No conclusion can be drawn about the effects of current levels of precipitation acidity on plant pathogen-host interactions. From these data it must be concluded that research on the effects of acidic precipitation on terrestrial vegetation is too meager to draw any conclusions with regard to an air quality standard.

  13. Acid Precipitation Learning Materials: Science, Environmental and Social Studies, Grades 6-12.

    ERIC Educational Resources Information Center

    Hessler, Edward W.

    The major environmental problem of acid precipition is addressed through a series of activities contained in this guide for teachers of grades 6 through 12. Exercises are provided to help students learn science inquiry skills, facts, and concepts while focusing on the acid rain situation. Activities are organized by content areas. These include:…

  14. Acid precipitation: things one can do - the Tug Hill Commission approach

    SciTech Connect

    Beevers, D.J.

    1982-01-01

    Acid precipitation is an international problem requiring more knowledge of its causes and effects, increased public awareness, and national policies to address it. New York's Temporary Tug Hill State Commission, with limited budget, small staff, and only regional jurisdiction, has sought to learn and provide information about acid precipitation and to impact public policy. The area receives a large quantity of highly acidic precipitation. For example, the average lab pH for 22 samples taken at Bennett Bridge between June and December 1980 (the only data available) was 4.09. Some red spruce and red maple die-back may be linked to acid precipitation. The Commission has implemented a variety of activities in response, including use of students to survey acid precipitation, policy statements, research projects on water quality and forest impacts, and design and implementation of a public opinion survey that may lead to additional public awareness, legislative action, and research. Most of these are relatively low-cost activities that similar agencies or other groups could participate in or initiate. 9 references, 3 figures.

  15. [Study on solid dispersion of precipitated calcium carbonate-based oleanolic acid].

    PubMed

    Yan, Hong-mei; Zhang, Zhen-hai; Jia, Xiao-bin; Jiang, Yan-rong; Sun, E

    2015-05-01

    Oleanolic acid-precipitated calcium carbonate solid dispersion was prepared by using solvent evaporation method. The microscopic structure and physicochemical properties of solid dispersion were analyzed using differential scanning calorimetry and scanning electron microscopy (SEM). And its in vitro release also was investigated. The properties of the precipitated calcium carbonate was studied which was as a carrier of oleanolic acid solid dispersion. Differential scanning calorimetry analysis suggested that oleanolic acid may be present in solid dispersion as amorphous substance. The in vitro release determination results of oleanolic acid-precipitated calcium carbonate (1: 5) solid dispersion showed accumulated dissolution rate of.oleanolic acid was up to 90% at 45 min. Accelerating experiment showed that content and in vitro dissolution of oleanolic acid solid dispersion did not change after storing over 6 months. The results indicated that in vitro dissolution of oleanolic acid was improved greatly by the solid dispersion with precipitated calcium carbonate as a carrier. The solid dispersion is a stabilizing system which has actual applied value.

  16. Reconciling Empirical Carbonate Clumped Isotope Calibrations: A Comparison of Calcite Precipitation and Acid Digestion Methods

    NASA Astrophysics Data System (ADS)

    Kelson, J.; Huntington, K. W.; Schauer, A. J.; Saenger, C.; Lechler, A. R.

    2015-12-01

    An accurate empirical calibration is necessary to confidently apply the carbonate clumped isotope (Δ47) thermometer. Previous synthetic carbonate calibrations disagree in temperature sensitivity, with one group of calibrations displaying a shallow Δ47-temperature slope (e.g., Dennis & Schrag, GCA, 2010), and the other a steep slope (e.g., Zaarur et al., EPSL, 2013). These calibrations differ in both the method of mineral precipitation and the temperature of the phosphoric acid used to digest carbonates for analysis, making it difficult to isolate the cause of the discrepancy. Here, we precipitate synthetic carbonates at temperatures of 6-80ºC using 4 different precipitation methods, and analyze the samples using both 90 and 25°C acid digestion. Precipitation experiments varied the use of salts (NaHCO3 and CaCl2) vs. dissolved CaCO3 as a starting solution, the use of carbonic anhydrase to promote isotopic equilibrium among dissolved inorganic carbon species in solution, and the method by which CO2 degasses to force carbonate precipitation. Carbonates precipitated by using salts and allowing CO2 to passively degas produce a shallow calibration slope that we hypothesize to approach isotopic equilibrium. Precipitation methods that bubble CO2 into solution then degas that CO2 (either passively or actively by bubbling N2) produce carbonates with consistently lower Δ47 and higher δ18O values for a given growth temperature. We infer that these carbonates grew in disequilibrium during rapid CO2 degassing. Varying acid digestion temperature does not change the results; acid fractionation factor is not correlated with grain size, Δ47, or d47 values. No precipitation method produces a steep calibration slope. Our large sample set of >60 carbonates lend confidence to a shallow slope calibration, and inform interpretations of Δ47 and δ18O values of natural carbonates that grow under conditions of isotopic disequilibrium.

  17. Selective precipitation of ribonucleic acid from a mixture of total cellular nucleic acids extracted from cultured mammalian cells

    PubMed Central

    Harrison, P. R.

    1971-01-01

    A simple and reproducible method is described for precipitating RNA selectively from total mammalian-cell nucleic acids extracted by the phenol–sodium dodecyl sulphate procedure at pH8.0. Under specified conditions bulk RNA is precipitated almost quantitatively whereas bulk DNA remains in solution. Minor components of RNA (detected by pulse-labelling and chromatography on methylated albumin–kieselguhr) and rapidly labelled components of DNA containing single-stranded regions are also precipitated. The usefulness of the method is discussed in the context of isolating separately both RNA and DNA from cultured cells that are difficult to obtain in quantity. PMID:5165620

  18. Composition and hygroscopicity of aerosol particles at Mt. Lu in South China: Implications for acid precipitation

    NASA Astrophysics Data System (ADS)

    Li, Weijun; Chi, Jianwei; Shi, Zongbo; Wang, Xinfeng; Chen, Bin; Wang, Yan; Li, Tao; Chen, Jianmin; Zhang, Daizhou; Wang, Zifa; Shi, Chune; Liu, Liangke; Wang, Wenxing

    2014-09-01

    Physicochemical properties of aerosol particles were studied at Mt. Lu, an elevated site (115°59‧E, 29°35‧N, 1165 m) within the acid precipitation area. Northeast winds transport copious amounts of air pollutants and water vapor from the Yangtze River Delta into this acid precipitation area. NH4+ and SO42- are the dominant ions in PM2.5 and determine aerosol acidity. Individual particle analysis shows abundant S-rich and metals (i.e. Fe-, Zn-, Mn-, and Pb-rich) particles. Unlike aerosol particles in North China and urban areas, there are little soot and mineral particles at Mt. Lu. Lack of mineral particles contributed to the higher acidity in precipitation in the research area. Nano-sized spherical metal particles were observed to be embedded in 37% of S-rich particles. These metal particles were likely originated from heavy industries and fired-power plants. Hygroscopic experiments show that most particles start to deliquesce at 73-76% but organic coating lowers the particle deliquescence relative humidity (DRH) to 63-73%. The DRHs of these aerosol particles are clearly smaller than that of pure ammonium sulfate particles which is 80%. Since RH in ambient air was relatively high, ranging from 65% to 85% during our study period, most particles at our sampling site were in liquid phase. Our results suggest that liquid phase reactions in aerosol particles may contribute to SO2 to sulfuric acid conversion in the acid precipitation area.

  19. The TCA Pathway is an Important Player in the Regulatory Network Governing Vibrio alginolyticus Adhesion Under Adversity

    PubMed Central

    Huang, Lixing; Huang, Li; Yan, Qingpi; Qin, Yingxue; Ma, Ying; Lin, Mao; Xu, Xiaojin; Zheng, Jiang

    2016-01-01

    Adhesion is a critical step in the initial stage of Vibrio alginolyticus infection; therefore, it is important to understand the underlying mechanisms governing the adhesion of V. alginolyticus and determine if environmental factors have any effect. A greater understanding of this process may assist in developing preventive measures for reducing infection. In our previous research, we presented the first RNA-seq data from V. alginolyticus cultured under stress conditions that resulted in reduced adhesion. Based on the RNA-seq data, we found that the Tricarboxylic acid cycle (TCA pathway) might be closely related to adhesion. Environmental interactions with the TCA pathway might alter adhesion. To validate this, bioinformatics analysis, quantitative Real-Time PCR (qPCR), RNAi, and in vitro adhesion assays were performed, while V. alginolyticus was treated with various stresses including temperature, pH, salinity, and starvation. The expression of genes involved in the TCA pathway was confirmed by qPCR, which reinforced the reliability of the sequencing data. Silencing of these genes was capable of reducing the adhesion ability of V. alginolyticus. Adhesion of V. alginolyticus is influenced substantially by environmental factors and the TCA pathway is sensitive to some environmental stresses, especially changes in pH and starvation. Our results indicated that (1) the TCA pathway plays a key role in V. alginolyticus adhesion: (2) the TCA pathway is sensitive to environmental stresses. PMID:26870007

  20. The TCA Pathway is an Important Player in the Regulatory Network Governing Vibrio alginolyticus Adhesion Under Adversity.

    PubMed

    Huang, Lixing; Huang, Li; Yan, Qingpi; Qin, Yingxue; Ma, Ying; Lin, Mao; Xu, Xiaojin; Zheng, Jiang

    2016-01-01

    Adhesion is a critical step in the initial stage of Vibrio alginolyticus infection; therefore, it is important to understand the underlying mechanisms governing the adhesion of V. alginolyticus and determine if environmental factors have any effect. A greater understanding of this process may assist in developing preventive measures for reducing infection. In our previous research, we presented the first RNA-seq data from V. alginolyticus cultured under stress conditions that resulted in reduced adhesion. Based on the RNA-seq data, we found that the Tricarboxylic acid cycle (TCA pathway) might be closely related to adhesion. Environmental interactions with the TCA pathway might alter adhesion. To validate this, bioinformatics analysis, quantitative Real-Time PCR (qPCR), RNAi, and in vitro adhesion assays were performed, while V. alginolyticus was treated with various stresses including temperature, pH, salinity, and starvation. The expression of genes involved in the TCA pathway was confirmed by qPCR, which reinforced the reliability of the sequencing data. Silencing of these genes was capable of reducing the adhesion ability of V. alginolyticus. Adhesion of V. alginolyticus is influenced substantially by environmental factors and the TCA pathway is sensitive to some environmental stresses, especially changes in pH and starvation. Our results indicated that (1) the TCA pathway plays a key role in V. alginolyticus adhesion: (2) the TCA pathway is sensitive to environmental stresses.

  1. Reuse of washing effluent containing oxalic acid by a combined precipitation-acidification process.

    PubMed

    Lim, Mihee; Kim, Myoung-Jin

    2013-01-01

    This study aims at evaluating the reuse feasibility of effluent produced by the soil washing of mine tailings with oxalic acid. Alkaline chemicals such as NaOH, Ca(OH)(2), and Na(2)CO(3) are used for the precipitation of arsenic and heavy metals in the effluent containing oxalic acid. All of the target contaminants are removed with very high efficiency (up to 100%) at high pH. The precipitation using NaOH at pH 9 is determined to be the most cost-effective method for the removal of arsenic as well as heavy metals in the effluent. The effluent decontaminated by NaOH is consecutively reused for the soil washing of raw mine tailings, resulting in considerable efficiency. Furthermore, even more arsenic and heavy metals are extracted from raw mine tailings by acidifying the decontaminated effluent under the alkaline condition, compared with direct reuse of the decontaminated effluent. Here, the oxalic acid, which is a weak complex-forming ligand as well as a weak acid, has noticeable effects on both soil washing and effluent treatment by precipitation. It extracts efficiently the contaminants from the mine tailings without adverse change of soil and also makes possible the precipitation of the contaminants in the effluent unlike strong chelating reagent. Reuse of the washing effluent containing oxalic acid would make the existing soil washing process more environment-friendly and cost-effective.

  2. Cloning and characterization of four novel coral acid-rich proteins that precipitate carbonates in vitro.

    PubMed

    Mass, Tali; Drake, Jeana L; Haramaty, Liti; Kim, J Dongun; Zelzion, Ehud; Bhattacharya, Debashish; Falkowski, Paul G

    2013-06-17

    Biomineralization is a widely dispersed and highly regulated but poorly understood process by which organisms precipitate minerals from a wide variety of elements [1]. For many years, it has been hypothesized that the biological precipitation of carbonates is catalyzed by and organized on an extracellular organic matrix containing a suite of proteins, lipids, and polysaccharides [2, 3]. The structures of these molecules, their evolutionary history, and the biophysical mechanisms responsible for calcification remain enigmatic. Despite the recognition that mineralized tissues contain proteins that are unusually rich in aspartic and glutamic acids [4-6], the role of these proteins in biomineralization remains elusive [5, 6]. Here we report, for the first time, the identification, cloning, amino acid sequence, and characterization of four highly acidic proteins, derived from expression of genes obtained from the common stony coral, Stylophora pistillata. Each of these four proteins can spontaneously catalyze the precipitation of calcium carbonate in vitro. Our results demonstrate that coral acid-rich proteins (CARPs) not only bind Ca(2+) stoichiometrically but also precipitate aragonite in vitro in seawater at pH 8.2 and 7.6, via an electrostatic interaction with protons on bicarbonate anions. Phylogenetic analysis suggests that at least one of the CARPs arose from a gene fusion. Similar, highly acidic proteins appear to have evolved several times independently in metazoans through convergence. Based purely on thermodynamic grounds, the predicted change in surface ocean pH in the next decades would appear to have minimal effect on the capacity of these acid-rich proteins to precipitate carbonates.

  3. IMPROVEMENT UPON THE CARRIER PRECIPITATION OF PLUTONIUM IONS FROM NITRIC ACID SOLUTIONS

    DOEpatents

    James, R.A.; Thompson, S.G.

    1958-12-23

    A process is reported for improving the removal of plutonlum by carrier precipitation by the addition of nitrite ions to a nitrlc acid solutlon of neutronirradiated unanium so as to destroy any hydrazine that may be present in the solution since the hydrazine tends to complex the tetravalent plutonium and prevents removal by the carrier precipltate, such as bismuth phospbate.

  4. Organic acids in precipitation in the Basque country (North of Spain)

    NASA Astrophysics Data System (ADS)

    Durana, N.; Casado, H.; García, C.; Ezcurra, A.; Lacaux, J. P.; Encinas, D.

    This paper discusses the results of the measurement of organic anions in precipitation collected since July 1989 in Olaeta, a rural village in the Basque Country (North of Spain). In order to gain a deeper knowledge of the characteristics and acids responsible for the free acidity observed in precipitation, a study was started within the EPOCA programme (Estudios en el Pirineo Occidental de la Contaminación Acida), for measuring organic anions: formiate, acetate and propionate. These results show that it was possible to observe organic anions in nearly every event, with a 5% contribution to the anionic total, and with an appreciable seasonal variation in concentration. The maximum contribution of organic acids to free acidity (H +) is 6% in rain events with pH≤5.0. There is significant correlation between acetic acid and inorganic ions of marine origin Cl -, Na + and Mg 2+ which might indicate the importance which the air masses of marine origin are going to have in the concentration of this acid. There is also significant correlation between formic acid and SO 42- and H + ions which might indicate the relatively importance contribution of formic acid to free acidity.

  5. Baseline acidity of precipitation at the South Pole during the last two millennia

    NASA Astrophysics Data System (ADS)

    Cragin, J. H.; Giovinetto, M. B.; Gow, A. J.

    Measurements of meltwater pH from annual layers of South Pole firn and ice samples ranging in age from 40 to 2000 years B.P. show that precipitation at this remote site has a higher natural acidity than that expected from atmospheric equilibrium with CO2. The average pH of deaerated (CO2-free) samples was 5.64 ± 0.08, while air-equilibrated samples averaged 5.37 ± 0.08, a pH that is about a factor of two more acidic than the expected background pH of 5.65. The observed “excess” acidity can be accounted for by SO42- and NO3- levels in the samples originating from non-anthropogenic H2SO4 and HNO3. Because of the presence of these naturally occurring acids in South Pole precipitation, a pH of 5.4 is considered a more representative baseline reference pH for acid precipitation studies.

  6. Effects of acid precipitation on reproduction in alpine plant species. [Erythronium grandiflorum; Aquilegia caerulea

    SciTech Connect

    McKenna, M.A.; Hille-Salgueiro, M.; Musselman, R.C. Dept. of Agriculture, Fort Collins, CO )

    1990-01-01

    A series of experiments were designed to determine the impact of acid rain on plant reproductive processes, a critical component of a species life history. Research was carried out in herbaceous alpine communities at the USDA (United States Department of Agriculture) Forest Service Glacier Lakes Ecosystem Experiments Site in the Snowy Mts. of Wyoming. A range of species were surveyed to monitor the sensitivity of pollen to acidification during germination and growth, and all species demonstrated reduced in vitro pollen germination in acidified media. Field pollinations were carried out in Erythronium grandiflorum and Aquilegia caerulea to determine the reproductive success of plants exposed to simulated ambient precipitation (pH 5.6) or simulated acid precipitation (pH 3.6) prior to pollination. In Erythronium, no differences were observed in seed set and seed weight of fruits resulting from the two pollination treatments. In Aquilegia, fruits resulting from the acid spray treatment produced fewer seeds and lighter seeds.

  7. Acid deposition in Maryland: Implications of the results of the National Acid Precipitation Assessment Program

    SciTech Connect

    DeMuro, J.; Bowmann, M.; Ross, J.; Blundell, C.; Price, R.

    1991-07-01

    Acid deposition, commonly referred to as 'acid rain,' is a major global environmental concern. Acid deposition has reportedly resulted in damage to aquatic, terrestrial, and physical resources and has potentially adverse effects on human health. A component of the Maryland acid deposition program is the preparation of an annual report that summarizes yearly activities and costs of ongoing acid deposition research and monitoring programs.

  8. Temporal trends in the acidity of precipitation and surface waters of New York

    USGS Publications Warehouse

    Peters, Norman E.; Schroeder, Roy A.; Troutman, David E.

    1982-01-01

    Statistical analyses of precipitation data from a nine-station monitoring network indicate little change in pH from 1965-78 within New York State as a whole but suggest that pH of bulk precipitation has decreased in the western part of the State by approximately 0.2 pH units since 1965 and increased in the eastern part by a similar amount. This trend is equivalent to an annual change in hydrogen-ion concentration of 0.2 microequivalents per liter. An average annual increase in precipitation quantity of 2 to 3 percent since 1965 has resulted in an increased acid load in the western and central parts of the State. During 1965-78, sulfate concentration in precipitation decreased an average of 1-4 percent annually. In general, no trend in nitrate was detected. Calculated trends in hydrogen-ion concentration do not correlate with measured trends of sulfate and nitrate, which suggests variable neutralization of hydrogen ion, possibly by particles from dry deposition. Neutralization has produced an increase of about 0.3 pH units in nonurban areas and 0.7 pH units in urban areas. Statistical analyses of chemical data from several streams throughout New York suggest that sulfate concentrations decreased an average of 1 to 4 percent per year. This decrease is comparable to the sulfate decrease in precipitation during the same period. In most areas of the State, chemical contributions from urbanization and farming, as well as the neutralizing effect of carbonate soils, conceal whatever effects acid precipitation may have on pH of streams.

  9. Fractionation of equine antivenom using caprylic acid precipitation in combination with cationic ion-exchange chromatography.

    PubMed

    Raweerith, Rutai; Ratanabanangkoon, Kavi

    2003-11-01

    A combined process of caprylic acid (CA) precipitation and ion-exchange chromatography on SP-Sepharose was studied as a means to fractionate pepsin-digested horse antivenom F(ab')(2) antibody. In the CA precipitation, the optimal concentration for fractionation of F(ab')(2) from pepsin-digested horse plasma was 2%, in which 89.61% of F(ab')(2) antibody activity was recovered in the supernatant with 1.5-fold purification. A significant amount of pepsin was not precipitated and remained active under these conditions. An analytical cation exchanger Protein-Pak SP 8HR HPLC column was tested to establish optimal conditions for the effective separation of IgG, albumin, pepsin and CA from the F(ab')(2) product. From these results, the supernatant from CA precipitation of pepsin-digested plasma was subjected to a SP-Sepharose column chromatography using a linear salt gradient. With stepwise elution, a peak containing F(ab')(2) antibody could be obtained by elution with 0.25 M NaCl. The total recovery of antibody was 65.56% with 2.91-fold purification, which was higher than that achieved by ammonium sulfate precipitation. This process simultaneously and effectively removed residual pepsin, high molecular weight aggregates and CA in the final F(ab')(2) product, and should be suitable for large-scale fractionation of therapeutic equine antivenoms.

  10. Biomediated Precipitation of Calcium Carbonate and Sulfur in a Faintly Acidic Hot Spring

    NASA Astrophysics Data System (ADS)

    Jiang, L.; Peng, X.; Qiao, H.

    2014-12-01

    A faintly acidic hot spring named "female Tower" (T=73.5 ℃, pH=6.64 ) is located in the Jifei Geothermal Field,Yunnan province, Southwest China. The precipitates in the hot spring are composed of large amounts of calcite and sulfur, as reveals by XRD analysis. Scanning electron microscopy (SEM) analysis show the microbial mats are formed of various coccoid, rod and filamentous microbes. Transmission electron microscopy (TEM) analysis show that intracellular sulfur granules are commonly associated with these microbes. Energy dispersive X-ray spectrometer (EDS) analysis shows that the surface of microbes are mainly composed of Ca, C, O and S. A culture-independent molecular phylogenetic analysis demonstrates the majority of bacteria in the spring are sulfur-oxidizing bacteria. In the spring water, H2S concentration was up to 60 ppm, while SO42- concentration was only about 10 ppm. We suggest that H2S might be utilized by sulfur-oxidizing bacteria in this hot spring water, leading to the formation of sulfur granules intracellularly and extracellularly. In the meantime, this reaction increases the pH in ambient environments, which fosters the precipitation of calcium carbonate precipitation in the microbial mats. This study suggests that the sulfur-oxidizing bacteria could play an important role in calcium carbonate precipitation in faintly acidic hot spring environments.

  11. Precipitation-chemistry measurements from the California Acid Deposition Monitoring Program, 1985-1990

    USGS Publications Warehouse

    Blanchard, Charles L.; Tonnessen, Kathy A.

    1993-01-01

    The configuration of the California Acid Deposition Monitoring Program (CADMP) precipitation network is described and quality assurance results summarized. Comparison of CADMP and the National Acid Deposition Program/National Trends Network (NADP/NTN) data at four parallel sites indicated that mean depth-weighted differences were less than 3 μeq ℓ−1 for all ions, being statistically significant for ammonium, sulfate and hydrogen ion. These apparently small differences were 15–30% of the mean concentrations of ammonium, sulfate and hydrogen ion. Mean depth-weighted concentrations and mass deposition rates for the period 1985–1990 are summarized; the latter were highest either where concentrations or precipitation depths were relatively high.

  12. Mitochondrial engineering of the TCA cycle for fumarate production.

    PubMed

    Chen, Xiulai; Dong, Xiaoxiang; Wang, Yuancai; Zhao, Zihao; Liu, Liming

    2015-09-01

    Microbial fumarate production from renewable feedstock is a promising and sustainable alternative to petroleum-based chemical synthesis. Here, mitochondrial engineering was used to construct the oxidative pathway for fumarate production starting from the TCA cycle intermediate α-ketoglutarate in Candida glabrata. Accordingly, α-ketoglutarate dehydrogenase complex (KGD), succinyl-CoA synthetase (SUCLG), and succinate dehydrogenase (SDH) were selected to be manipulated for strengthening the oxidative pathway, and the engineered strain T.G-K-S-S exhibited increased fumarate biosynthesis (1.81 g L(-1)). To further improve fumarate production, the oxidative route was optimized. First, three fusion proteins KGD2-SUCLG2, SUCLG2-SDH1 and KGD2-SDH1 were constructed, and KGD2-SUCLG2 led to improved fumarate production (4.24 g L(-1)). In addition, various strengths of KGD2-SUCLG2 and SDH1 expression cassettes were designed by combinations of promoter strengths and copy numbers, resulting in a large increase in fumarate production (from 4.24 g L(-1) to 8.24 g L(-1)). Then, through determining intracellular amino acids and its related gene expression levels, argininosuccinate lyase in the urea cycle was identified as the key factor for restricting higher fumarate production. Correspondingly, after overexpression of it, the fumarate production was further increased to 9.96 g L(-1). Next, two dicarboxylic acids transporters facilitated an improvement of fumarate production, and, as a result, the final strain T.G-KS(H)-S(M)-A-2S reached fumarate titer of 15.76 g L(-1). This strategy described here paves the way to the development of an efficient pathway for microbial production of fumarate.

  13. Silica precipitation in acidic solutions: mechanism, pH effect, and salt effect.

    PubMed

    Gorrepati, Elizabeth A; Wongthahan, Pattanapong; Raha, Sasanka; Fogler, H Scott

    2010-07-06

    This study is the first to show that silica precipitation under very acidic conditions ([HCl] = 2-8 M) proceeds through two distinct steps. First, the monomeric form of silica is quickly depleted from solution as it polymerizes to form primary particles approximately 5 nm in diameter. Second, the primary particles formed then flocculate. A modified Smoluchowski equation that incorporates a geometric population balance accurately describes the exponential growth of silica flocs. Variation of the HCl concentration between 2 and 8 M further showed that polymerization to form primary particles and subsequent particle flocculation become exponentially faster with increasing acid concentration. The effect of salt was also studied by adding 1 M chloride salts to the solutions; it was found that salts accelerated both particle formation and growth rates in the order: AlCl(3) > CaCl(2) > MgCl(2) > NaCl > CsCl > no salt. It was also found that ionic strength, over cation identity, determines silica polymerization and particle flocculation rates. This research reveals that precipitation of silica products from acid dissolution of minerals can be studied apart from the mineral dissolution process. Thus, silica product precipitation from mineral acidization follows a two-step process--formation of 5 nm primary particles followed by particle flocculation--which becomes exponentially faster with increasing HCl concentration and with salts accelerating the process in the above order. This result has implications for any study of acid dissolution of aluminosilicate or silicate material. In particular, the findings are applicable to the process of acidizing oil-containing rock formations, a common practice of the petroleum industry where silica dissolution products encounter a low-pH, salty environment within the oil well.

  14. Influence of phosphate and silica on U(VI) precipitation from acidic and neutralized wastewaters

    SciTech Connect

    Kanematsu, Masakazu; Perdrial, Nicolas; Um, Wooyong; Chorover, Jon; O'Day, Peggy A.

    2014-06-03

    Uranium speciation and physical-chemical characteristics were studied in solids precipitated from synthetic acidic to circumneutral wastewaters in the presence and absence of dissolved silica and phosphate to examine thermodynamic and kinetic controls on phase formation. Composition of synthetic wastewater was based on disposal sites 216-U-8 and 216-U-12 Cribs at the Hanford site (WA, USA). In the absence of dissolved silica or phosphate, crystalline or amorphous uranyl oxide hydrates, either compreignacite or meta-schoepite, precipitated at pH 5 or 7 after 30 d of reaction, in agreement with thermodynamic calculations. In the presence of 1 mM dissolved silica representative of groundwater concentrations, amorphous phases dominated by compreignacite precipitated rapidly at pH 5 or 7 as a metastable phase and formation of poorly-crystalline boltwoodite, the thermodynamically stable uranyl silicate phase, was slow. In the presence of phosphate (3 mM), meta-ankoleite initially precipitated as the primary phase at pH 3, 5, or 7 regardless of the presence of 1 mM dissolved silica. Analysis of precipitates by U LIII-edge EXAFS indicated that “autunite-type” sheets of meta-ankoleite transformed to “phosphuranylite-type” sheets after 30 d of reaction, probably due to Ca substitution in the structure. Low solubility of uranyl phosphate phases limits dissolved U(VI) concentrations but differences in particle size, crystallinity, and precipitate composition vary with pH and base cation concentration, which will influence the thermodynamic and kinetic stability of these phases.

  15. Colloidal precipitates related to Acid Mine Drainage: bacterial diversity and micro fungi-heavy metal interactions

    NASA Astrophysics Data System (ADS)

    Lucchetti, G.; Carbone, C.; Consani, S.; Zotti, M.; Di Piazza, S.; Pozzolini, M.; Giovine, M.

    2015-12-01

    In Acid Mine Drainage (AMD) settings colloidal precipitates control the mobility of Potential Toxic Elements (PTEs). Mineral-contaminant relationships (i.e. adsorption, ion-exchange, desorption) are rarely pure abiotic processes. Microbes, mainly bacteria and microfungi, can catalyze several reactions modifying the element speciation, as well as the bioavailability of inorganic pollutants. Soil, sediments, and waters heavily polluted with PTEs through AMD processes are a potential reservoir of extremophile bacteria and fungi exploitable for biotechnological purposes. Two different AMD related colloids, an ochraceous precipitate (deposited in weakly acidic conditions, composed by nanocrystalline goethite) and a greenish-blue precipitate (deposited at near-neutral pH, composed by allophane + woodwardite) were sampled. The aims of this work were to a) characterize the mycobiota present in these colloidal minerals by evaluating the presence of alive fungal propagules and extracting bacteria DNA; b) verify the fungal strains tolerance, and bioaccumulation capability on greenish-blue and ZnSO4 enriched media; c) evaluate potential impact of bacteria in the system geochemistry. The preliminary results show an interesting and selected mycobiota able to survive under unfavourable environmental conditions. A significant number of fungal strains were isolated in pure culture. Among them, species belonging to Penicillium and Trichoderma genera were tested on both greenish-blue and ZnSO4 enriched media. The results show a significant tolerance and bioaccumulation capability to some PTEs. The same colloidal precipitates were processed to extract bacteria DNA by using a specific procedure developed for sediments. The results give a good yield of nucleic acids and a positive PCR amplification of 16S rDNA accomplished the first step for future metagenomic analyses.

  16. Influence of Aldrich humic acid and metal precipitates on survivorship of mayflies (Atalophlebia spp.) to acid mine drainage.

    PubMed

    Holland, Aleicia; Duivenvoorden, Leo J; Kinnear, Susan H W

    2014-03-01

    Humic substances (HS) have been shown to decrease the toxicity of environmental stressors, but knowledge of their ability to influence the toxicity of multiple stressors such as metal mixtures and low pH associated with acid mine drainage (AMD) is still limited. The present study investigated the ability of HS to decrease toxicity of AMD to mayflies (Atalophlebia spp.). The AMD was collected from the Mount Morgan (Mount Morgan, Queensland, Australia) open pit. Mayflies were exposed to concentrations of AMD at 0%, 1%, 2%, 3%, and 4% in the presence of 0 mg/L, 10 mg/L, and 20 mg/L Aldrich humic acid (AHA). A U-shaped response was noted in all AHA treatments, with higher rates of mortality recorded in the 2% and 3% dilutions compared with 4%. This result was linked with increased precipitates in the lower concentrations. A follow-up trial showed significantly higher concentrations of precipitates in the 2% and 3% AMD dilutions in the 0 mg/L AHA treatment and higher precipitates in the 2% AMD, 10 mg/L and 20 mg/L AHA, treatments. Humic substances were shown to significantly increase survival of mayflies exposed to AMD by up to 50% in the 20 mg/L AHA treatment. Humic substances may have led to increased survival after AMD exposure through its ability to influence animal physiology and complex heavy metals. These results are valuable in understanding the ability of HS to influence the toxicity of multiple stressors.

  17. Biomediated Precipitation of Calcium Carbonate in a Slightly Acidic Hot Spring

    NASA Astrophysics Data System (ADS)

    Jiang, L.

    2015-12-01

    A slightly acidic hot spring named "Female Tower" (T=73.5 °C, pH=6.64) is located in the Jifei Geothermal Field, Yunnan Province, Southwest China. The precipitates in the hot spring are composed of large amounts of calcite, aragonite, and sulfur. Scanning electron microscopy (SEM) analyses revealed that the microbial mats were formed of various coccoid, rod-shaped, and filamentous microbes. Transmission electron microscopy (TEM) showed that the intracellular sulfur granules were commonly associated with these microbes. A culture-independent molecular phylogenetic analysis demonstrated that the majority of the bacteria in the spring were sulfur-oxidizing bacteria. In the spring water, H2S concentration was up to 60 ppm, while SO42- concentration was only about 10 ppm. We speculated that H2S might be utilized by sulfur-oxidizing bacteria in this hot spring water, leading to the intracellular formation of sulfur granules. In the meantime, this reaction increased the pH in the micron-scale microdomains, which fostered the precipitation of calcium carbonate in the microbial mats. The results of this study indicated that the sulfur-oxidizing bacteria could play an important role in calcium carbonate precipitation in slightly acidic hot spring environments.

  18. Design of an AdvancedTCA board management controller (IPMC)

    NASA Astrophysics Data System (ADS)

    Mendez, J.; Bobillier, V.; Haas, S.; Joos, M.; Mico, S.; Vasey, F.

    2017-03-01

    The AdvancedTCA (ATCA) standard has been selected as the hardware platform for the upgrade of the back-end electronics of the CMS and ATLAS experiments of the Large Hadron Collider (LHC) . In this context, the electronic systems for experiments group at CERN is running a project to evaluate, specify, design and support xTCA equipment. As part of this project, an Intelligent Platform Management Controller (IPMC) for ATCA blades, based on a commercial solution, has been designed to be used on existing and future ATCA blades. This paper reports on the status of this project presenting the hardware and software developments.

  19. Preparation of All-Trans Retinoic Acid nanosuspensions using a modified precipitation method.

    PubMed

    Zhang, X; Xia, Q; Gu, N

    2006-08-01

    All-Trans Retinoic Acid (ATRA) nanosuspensions were prepared with a modified precipitation method. The ATRA solution in acetone was injected into pure water by an air compressor under the action of ultrasonication. Photon correlation spectroscopy results showed that the mean particle size of ATRA nanoparticles in nanosuspensions reduced from 337 nm to 155 nm as the injection velocity increased and the polydispersity index was 0.45-0.50. The morphology of ATRA nanoparticles varied with the different concentration of ATRA solution in acetone. ATRA nanoparticles showed an amorphous state and stable in 6 months. It could be concluded that this modified precipitation method could produce stable and controllable ATRA nanosuspension to a certain extent, thus benefit for higher saturation solubility.

  20. Factors affecting the rate of hydrolysis of phenylboronic acid in lab-scale precipitate reactor studies

    SciTech Connect

    Bannochie, C.J.; Marek, J.C.; Eibling, R.E.; Baich, M.A.

    1992-01-01

    Removing aromatic carbon from an aqueous slurry of cesium-137 and other alkali tetraphenylborates by acid hydrolysis will be an important step in preparing high-level radioactive waste for vitrification at the Savannah River Site's Defense Waste Processing Facility (DWPF). Kinetic data obtained in bench-scale precipitate hydrolysis reactors suggest changes in operating parameters to improve product quality in the future plant-scale radioactive operation. The rate-determining step is the removal of the fourth phenyl group, i.e. hydrolysis of phenylboronic acid. Efforts to maximize this rate have established the importance of several factors in the system, including the ratio of copper(II) catalyst to formic acid, the presence of nitrite ion, reactions of diphenylmercury, and the purge gas employed in the system.

  1. Factors affecting the rate of hydrolysis of phenylboronic acid in lab-scale precipitate reactor studies

    SciTech Connect

    Bannochie, C.J.; Marek, J.C.; Eibling, R.E.; Baich, M.A.

    1992-10-01

    Removing aromatic carbon from an aqueous slurry of cesium-137 and other alkali tetraphenylborates by acid hydrolysis will be an important step in preparing high-level radioactive waste for vitrification at the Savannah River Site`s Defense Waste Processing Facility (DWPF). Kinetic data obtained in bench-scale precipitate hydrolysis reactors suggest changes in operating parameters to improve product quality in the future plant-scale radioactive operation. The rate-determining step is the removal of the fourth phenyl group, i.e. hydrolysis of phenylboronic acid. Efforts to maximize this rate have established the importance of several factors in the system, including the ratio of copper(II) catalyst to formic acid, the presence of nitrite ion, reactions of diphenylmercury, and the purge gas employed in the system.

  2. Recovery of molybdenum, nickel and cobalt by precipitation from the acidic leachate of a mineral sludge.

    PubMed

    Vemic, M; Bordas, F; Comte, S; Guibaud, G; Lens, P N L; van Hullebusch, E D

    2016-09-01

    The objective of this study was to investigate the recovery potential of molybdenum (Mo), nickel (Ni) and cobalt (Co) from synthetic and real acidic leachate of a mineral sludge from a metal recycling plant by sulfide precipitation. The operational parameters (metal sulfide (M/S) ratio 0.1-1, agitation speed 0-100 rpm, contact time 15-120 min and pH 1-5) were optimized in batch conditions on synthetic metal leachate (0.5 M HNO3, Mo = 101.6 mg L(-1), Ni = 70.8 mg L(-1), Co = 27.1 mg L(-1)) with a 0.1 M Na2S solution. Additionally, recovery of the target metals was theoretically simulated with a chemical equilibrium model (Visual MINTEQ 3.0). The optimized Na2S precipitation of metals from the synthetic leachate resulted in the potential selective recovery of Mo at pH 1 (98% by modeling, 95% experimental), after simultaneous precipitation of Ni and Co as sulfide at pH 4 (100% by modeling, 98% experimental). Metal precipitation from the real leachate (18 M H2SO4, Mo = 10,160 mg L(-1), Ni = 7,080 mg L(-1), Co = 2,710 mg L(-1)) was performed with 1 M Na2S, and resulted in a maximal Mo recovery at pH 2 (50%), while maximal recoveries of Ni and Co were observed at pH 4 (56% and 60%, respectively). Real leachate gave a lower metals recovery efficiency compared with synthetic leachate, which can be attributed to changes in the pH, nature of leachant, co-precipitation of Zn and competition for S(2-) ions.

  3. Purification of IgG from serum with caprylic acid and ammonium sulphate precipitation is not superior to ammonium sulphate precipitation alone.

    PubMed

    Mohanty, J G; Elazhary, Y

    1989-01-01

    Immunoglobulin G (IgG) from bovine serum raised against Aeromonas Salmonicida was purified by ammonium sulphate precipitation (ASP) or caprylic acid treatment followed by ammonium sulphate precipitation (CAAS). Purity of IgG samples prepared by both methods were examined by High Performance Gel Permeation Chromatography, electrophoresis and antibody activity assay. Results suggest that IgG prepared by ASP is better than that obtained by CAAS method in terms of the yield of the IgG monomers and the recovery of the antibody activity.

  4. Correlation between TCA cycle flux and glucose uptake rate during respiro-fermentative growth of Saccharomyces cerevisiae.

    PubMed

    Heyland, Jan; Fu, Jianan; Blank, Lars M

    2009-12-01

    Glucose repression of the tricarboxylic acid (TCA) cycle in Saccharomyces cerevisiae was investigated under different environmental conditions using (13)C-tracer experiments. Real-time quantification of the volatile metabolites ethanol and CO(2) allowed accurate carbon balancing. In all experiments with the wild-type, a strong correlation between the rates of growth and glucose uptake was observed, indicating a constant yield of biomass. In contrast, glycerol and acetate production rates were less dependent on the rate of glucose uptake, but were affected by environmental conditions. The glycerol production rate was highest during growth in high-osmolarity medium (2.9 mmol g(-1) h(-1)), while the highest acetate production rate of 2.1 mmol g(-1) h(-1) was observed in alkaline medium of pH 6.9. Under standard growth conditions (25 g glucose l(-1) , pH 5.0, 30 degrees C) S. cerevisiae had low fluxes through the pentose phosphate pathway and the TCA cycle. A significant increase in TCA cycle activity from 0.03 mmol g(-1) h(-1) to about 1.7 mmol g(-1) h(-1) was observed when S. cerevisiae grew more slowly as a result of environmental perturbations, including unfavourable pH values and sodium chloride stress. Compared to experiments with high glucose uptake rates, the ratio of CO(2) to ethanol increased more than 50 %, indicating an increase in flux through the TCA cycle. Although glycolysis and the ethanol production pathway still exhibited the highest fluxes, the net flux through the TCA cycle increased significantly with decreasing glucose uptake rates. Results from experiments with single gene deletion mutants partially impaired in glucose repression (hxk2, grr1) indicated that the rate of glucose uptake correlates with this increase in TCA cycle flux. These findings are discussed in the context of regulation of glucose repression.

  5. Contribution of natural and anthropogenic emissions to acid precipitation formation in the Mexico City Metropolitan Area

    SciTech Connect

    Garcia, L.; Barrera, G.; Castellanos, L.; Moreno, D.

    1996-12-31

    The emissions of precursor compounds that contribute significantly the formation of acid precipitation in urban areas are associated with the burning of fossils fuels from mobile, area and point sources. In Mexico City, these include services, institutions and residences aggregated as area sources, as well as industrial point sources, including smelting, refinement of petroleum and power generation. In addition, dusts from soil erosion and lack of vegetation in the urban landscape contribute to modification of natural rain water. It is common knowledge that acid precipitation characterizes a large variety of compounds, as much related to precursor emissions as to prevailing environmental factors. This study attempts to establish the contribution of natural and anthropogenic emissions and meteorological conditions during the rainy season by analysis of spatial and temporal distributions, as of different ions in solution with rain water, as well as the modeling of wind patterns, as represented by using the arc/info software. This study`s results also show the geographic areas impacted by the acid rain phenomenon and the acidification rates in the Mexico City Metropolitan Area during the past 3 years.

  6. Precipitation of heavy metals from acid mine drainage and their geochemical modeling

    NASA Astrophysics Data System (ADS)

    Petrilakova, Aneta; Balintova, Magdalena; Holub, Marian

    2014-06-01

    Geochemical modeling plays an increasingly vital role in a number of areas of geoscience, ranging from groundwater and surface water hydrology to environmental preservation and remediation. Geochemical modeling is also used to model the interaction processes at the water - sediment interface in acid mine drainage (AMD). AMD contains high concentrations of sulfate and dissolved metals and it is a serious environmental problem in eastern Slovakia. The paper is focused on comparing the results of laboratory precipitation of metal ions from AMD (the Smolnik creek, Slovakia) with the results obtained by geochemical modeling software Visual Minteq 3.0.

  7. Seasonal factors controlling mineral precipitation in the acid mine drainage at Donghae coal mine, Korea.

    PubMed

    Kim, J J; Kim, S J

    2004-06-05

    Monitoring over a 12 month period in the Sanae creek flow in acid mine drainage, Donghae coal mine area, demonstrates that the concentrations of dissolved metals and sulphate are highest during autumn when water flow in the creek is at its lowest. The highest pH values of the stream were measured in April and May, whereas the lowest pH was recorded in October. The Fe concentration of stream water rapidly decreased downstream due to the precipitation of Fe oxyhydroxide and/or oxyhydroxysulfate phases in the stream. Mineral precipitates in the creek in the Donghae mine area show various colours such as brownish yellow (Munsell colour 9.5 YR hues), reddish brown (Munsell colour 3.5 YR hues) and white depending on seasons and distance from the pollution source in the creek. Such phenomena are attributed to the variation in pH and chemical composition of stream water caused by seasonal factors. The measured pH ranges in stream water of the brownish yellow, white and reddish brown precipitates are pH 3.2-4.5, 4.5-6.0 and 5.3-6.9, respectively.

  8. Histone-dependent IgG conservation in octanoic acid precipitation and its mechanism.

    PubMed

    Chen, Quan; Toh, Phyllicia; Sun, Yue; Latiff, Sarah Maria Abdul; Hoi, Aina; Xian, Mo; Zhang, Haibo; Nian, Rui; Zhang, Wei; Gagnon, Pete

    2016-12-01

    Octanoic acid (OA) precipitation has long been used in protein purification. Recently, we reported a new cell culture clarification method for immunoglobulin G (IgG) purification, employing an advance elimination of chromatin heteroaggregates with a hybrid OA-solid phase system. This treatment reduced DNA more than 3 logs, histone below the detection limit (LOD), and non-histone host cell proteins (nh-HCP) by 90 % while conserving more than 90 % of the IgG monomer. In this study, we further investigated the conservation of IgG monomer and antibody light chain (LC) to the addition of OA/OA-solid phase complex, with or without histone and DNA in different combinations. The results showed that highly basic histone protein was the prime target in OA/OA-solid phase precipitation system for IgG purification, and the selective conservation of IgG monomer in this system was histone dependent. Our findings partially support the idea that OA works by sticking to electropositive hydrophobic domains on proteins, reducing their solubility, and causing them to agglomerate into large particles that precipitate from solution. Our findings also provide a new perspective for IgG purification and emphasize the necessity to re-examine the roles of various host contaminants in IgG purification.

  9. Comparison of Four Strong Acids on the Precipitation Potential of Gypsum in Brines During Distillation of Pretreated, Augmented Urine

    NASA Technical Reports Server (NTRS)

    Muirhead, Dean

    2011-01-01

    Two batches of nominally pretreated and augmented urine were prepared with the baseline pretreatment formulation of sulfuric acid and chromium trioxide. The urine was augmented with inorganic salts and organic compounds in order to simulate a urinary ionic concentrations representing the upper 95 percentile on orbit. Three strong mineral acids: phosphoric, hydrochloric, and nitric acid, were substituted for the sulfuric acid for comparison to the baseline sulfuric acid pretreatment formulation. Three concentrations of oxidizer in the pretreatment formulation were also tested. Pretreated urine was distilled to 85% water recovery to determine the effect of each acid and its conjugate base on the precipitation of minerals during distillation. The brines were analyzed for calcium and sulfate ion, total, volatile, and fixed suspended solids. Test results verified that substitution of phosphoric, hydrochloric, or nitric acids for sulfuric acid would prevent the precipitation of gypsum up to 85% recovery from pretreated urine representing the upper 95 percentile calcium concentration on orbit.

  10. Carbonate precipitation under bulk acidic conditions as a potential biosignature for searching life on Mars

    NASA Astrophysics Data System (ADS)

    Fernández-Remolar, David C.; Preston, Louisa J.; Sánchez-Román, Mónica; Izawa, Matthew R. M.; Huang, L.; Southam, Gordon; Banerjee, Neil R.; Osinski, Gordon R.; Flemming, Roberta; Gómez-Ortíz, David; Prieto Ballesteros, Olga; Rodríguez, Nuria; Amils, Ricardo; Darby Dyar, M.

    2012-10-01

    Recent observations of carbonate minerals in ancient Martian rocks have been interpreted as evidence for the former presence of circumneutral solutions optimal for carbonate precipitation. Sampling from surface and subsurface regions of the low-pH system of Río Tinto has shown, unexpectedly, that carbonates can form under diverse macroscopic physicochemical conditions ranging from very low to neutral pH (1.5-7.0). A multi-technique approach demonstrates that carbonate minerals are closely associated with microbial activity. Carbonates occur in the form of micron-size carbonate precipitates under bacterial biofilms, mineralization of subsurface colonies, and possible biogenic microstructures including globules, platelets and dumbbell morphologies. We propose that carbonate precipitation in the low-pH environment of Río Tinto is a process enabled by microbially-mediated neutralization driven by the reduction of ferric iron coupled to the oxidation of biomolecules in microbially-maintained circumneutral oases, where the local pH (at the scale of cells or cell colonies) can be much different than in the macroscopic environment. Acidic conditions were likely predominant in vast regions of Mars over the last four billion years of planetary evolution. Ancient Martian microbial life inhabiting low-pH environments could have precipitated carbonates similar to those observed at Río Tinto. Preservation of carbonates at Río Tinto over geologically significant timescales suggests that similarly-formed carbonate minerals could also be preserved on Mars. Such carbonates could soon be observed by the Mars Science Laboratory, and by future missions to the red planet.

  11. Biogenic precipitation of manganese oxides and enrichment of heavy metals at acidic soil pH

    NASA Astrophysics Data System (ADS)

    Mayanna, Sathish; Peacock, Caroline L.; Schäffner, Franziska; Grawunder, Anja; Merten, Dirk; Kothe, Erika; Büchel, Georg

    2014-05-01

    The precipitation of biogenic Mn oxides at acidic pH is rarely reported and poorly understood, compared to biogenic Mn oxide precipitation at near neutral conditions. Here we identified and investigated the precipitation of biogenic Mn oxides in acidic soil, and studied their role in the retention of heavy metals, at the former uranium mining site of Ronneburg, Germany. The site is characterized by acidic pH, low carbon content and high heavy metal loads including rare earth elements. Specifically, the Mn oxides were present in layers identified by detailed soil profiling and within these layers pH varied from 4.7 to 5.1, Eh varied from 640 to 660 mV and there were enriched total metal contents for Ba, Ni, Co, Cd and Zn in addition to high Mn levels. Using electron microprobe analysis, synchrotron X-ray diffraction and X-ray absorption spectroscopy, we identified poorly crystalline birnessite (δ-MnO2) as the dominant Mn oxide in the Mn layers, present as coatings covering and cementing quartz grains. With geochemical modelling we found that the environmental conditions at the site were not favourable for chemical oxidation of Mn(II), and thus we performed 16S rDNA sequencing to isolate the bacterial strains present in the Mn layers. Bacterial phyla present in the Mn layers belonged to Firmicutes, Actinobacteria and Proteobacteria, and from these phyla we isolated six strains of Mn(II) oxidizing bacteria and confirmed their ability to oxidise Mn(II) in the laboratory. The biogenic Mn oxide layers act as a sink for metals and the bioavailability of these metals was much lower in the Mn layers than in adjacent layers, reflecting their preferential sorption to the biogenic Mn oxide. In this presentation we will report our findings, concluding that the formation of natural biogenic poorly crystalline birnessite can occur at acidic pH, resulting in the formation of a biogeochemical barrier which, in turn, can control the mobility and bioavailability of heavy metals in

  12. Microscopic evaluation of trace metals in cloud droplets in an acid precipitation region.

    PubMed

    Li, Weijun; Wang, Yan; Collett, Jeffrey L; Chen, Jianmin; Zhang, Xiaoye; Wang, Zifa; Wang, Wenxing

    2013-05-07

    Mass concentrations of soluble trace metals and size, number, and mixing properties of nanometal particles in clouds determine their toxicity to ecosystems. Cloud water was found to be acidic, with a pH of 3.52, at Mt. Lu (elevation 1,165 m) in an acid precipitation region in South China. A combination of Inductively Coupled Plasma Mass Spectrometry (ICPMS) and Transmission Electron Microscopy (TEM) for the first time demonstrates that the soluble metal concentrations and solid metal particle number are surprisingly high in acid clouds at Mt. Lu, where daily concentrations of SO2, NO2, and PM10 are 18 μg m(-3), 7 μg m(-3), and 22 μg m(-3). The soluble metals in cloudwater with the highest concentrations were zinc (Zn, 200 μg L(-1)), iron (Fe, 88 μg L(-1)), and lead (Pb, 77 μg L(-1)). TEM reveals that 76% of cloud residues include metal particles that range from 50 nm to 1 μm diameter with a median diameter of 250 nm. Four major metal-associated particle types are Pb-rich (35%), fly ash (27%), Fe-rich (23%), and Zn-rich (15%). Elemental mapping shows that minor soluble metals are distributed within sulfates of cloud residues. Emissions of fine metal particles from large, nonferrous industries and coal-fired power plants with tall stacks were transported upward to this high elevation. Our results suggest that the abundant trace metals in clouds aggravate the impacts of acid clouds or associated precipitation on the ecosystem and human health.

  13. Evaluation of simulated acid precipitation effects on forest microcosms. Final report

    SciTech Connect

    Kelly, J.M.; Strickland, R.C.; Weatherford, F.P.; Noggle, J.C.

    1984-04-01

    Microcosms were treated for a 30-month period with simulated precipitation acidified to four pH levels (5.7, 4.5, 4.0, and 3.5) to evaluate the impact of acid precipitation on foliar leaching, plant nutrient content, soil leaching, soil nutrient content, and litter decomposition. Direct effects of acid precipitation on diameter growth, bud break, leaf senescence, chlorophyll content, stomatal size, stomatal density, photosynthesis, respiration, transpiration, and cuticle erosion were evaluated on tulip poplar, white oak, and Virginia pine seedlings growing as mixed stands in the microcosms. None of the plant physiological or morphological parameters evaluated responded in a statistically significant manner as a result of treatment. A significant treatment canopy interaction was observed in the form of a 60 percent increase in calcium input in throughfall in response to the pH 3.5 treatment. Foliar nutrient content did not change in response to treatment nor did field measurements of decomposer activity. Soil analysis indicated a significantly lower concentration of exchangeable calcium and magnesium in the top 3.5 cm of the mineral soil in association with the pH 3.5 treatment. Soil leachate concentrations exhibited significant increases at both the 25 and 50 cm depths. However, at the 100 cm depth no significant response in concentration or elemental loss from the system was observed. Laboratory respiration measurements indicated a small, but statistically significant reduction in decomposer activity in the lower litter (02) horizon. This reduction was masked in the field measurements of decomposer activity due to the relatively small contribution of the 02 to total soil respiration. 38 references, 12 figures, 18 tables.

  14. Effectiveness of coagulation and acid precipitation processes for the pre-treatment of diluted black liquor.

    PubMed

    Garg, Anurag; Mishra, I M; Chand, S

    2010-08-15

    The effectiveness of coagulation (using aluminium-based chemicals and ferrous sulfate) and acid precipitation (using H(2)SO(4)) processes for the pre-treatment of diluted black liquor obtained from a pulp and paper mill is reported. Commercial alum was found to be the most economical among all the aluminium and ferrous salts used as a coagulant. A maximum removal of chemical oxygen demand (COD) (ca. 63%) and colour reduction (ca. 90%) from the wastewater (COD = 7000 mg l(-1)) at pH 5.0 was obtained with alum. During the acid precipitation process, at pH < 5.0, significant COD reductions (up to 64%) were observed. Solid residue obtained from the alum treatment at a temperature of 95 degrees C showed much better (3 times) settling rate than that for the residue obtained after treatment with the same coagulant at a temperature of 25 degrees C. The settling curves had three parts, namely, hindered, transition and compression zones. Tory plots were used to determine the critical height of suspension-supernatant interface that is used in the design of a clarifier-thickener unit. High heating values and large biomass fraction of the solid residues can encourage the fuel users to use this waste derived sludge as a potential renewable energy source.

  15. Technical and economical assessment of formic acid to recycle phosphorus from pig slurry by a combined acidification-precipitation process.

    PubMed

    Daumer, M-L; Picard, S; Saint-Cast, P; Dabert, P

    2010-08-15

    Dissolution by acidification followed by a liquid/solid separation and precipitation of phosphorus from the liquid phase is one possibility to recycle phosphorus from livestock effluents. To avoid increase of effluent salinity by using mineral acids in the recycling process, the efficiency of two organic acids, formic and acetic acid, in dissolving the mineral phosphorus from piggery wastewater was compared. The amount of formic acid needed to dissolve the phosphorus was reduced three fold, compared to acetic acid. The amount of magnesium oxide needed for further precipitation was decreased by two with formic acid. Neither the carbon load nor the effluent salinity was significantly increased by using formic acid. An economical comparison was performed for the chemical recycling process (mineral fertilizer) vs. centrifugation (organic fertilizer) considering the centrifugation and the mineral fertilizers sold in the market. After optimisation of the process, the product could be economically competitive with mineral fertilizer as superphosphate in less than 10 years.

  16. National Acid Precipitation Assessment Program Report to Congress: An Integrated Assessment

    SciTech Connect

    Uhart, M.; et al,

    2005-08-01

    Under Title IX of the 1990 Clean Air Act Amendments, Congress reauthorized the National Acid Precipitation Assessment Program (NAPAP) to continue coordinating acid rain research and monitoring, as it had done during the previous decade, and to provide Congress with periodic reports. In particular, Congress asked NAPAP to assess all available data and information to answer two questions: (1) What are the costs, benefits, and effectiveness of Title IV? This question addresses the costs and economic impacts of complying with the Acid Rain Program as well as benefit analyses associated with the various human health and welfare effects, including reduced visibility, damages to materials and cultural resources, and effects on ecosystems. (2) What reductions in deposition rates are needed to prevent adverse ecological effects? This complex questions addresses ecological systems and the deposition levels at which they experience harmful effects. The results of the assessment of the effects of Title IV and of the relationship between acid deposition rates and ecological effects were to be reported to Congress quadrennially, beginning with the 1996 report to Congress. The objective of this Report is to address the two main questions posed by Congress and fully communicate the results of the assessment to decision-makers. Given the primary audience, most of this report is not written as a technical document, although information supporting the conclusions is provided along with references.

  17. Precipitation of Metallic Cations by the Acidic Exopolysaccharides from Bradyrhizobium japonicum and Bradyrhizobium (Chamaecytisus) Strain BGA-1

    PubMed Central

    Corzo, J.; León-Barrios, M.; Hernando-Rico, V.; Gutierrez-Navarro, A. M.

    1994-01-01

    The interaction between the acidic exopolysaccharides produced by two Bradyrhizobium strains and several metal cations has been studied. Aqueous solutions in the millimolar range of Fe3+ but not of Fe2+ precipitated the exopolysaccharides from Bradyrhizobium (Chamaecytisus) strain BGA-1 and, to a lesser extent, Bradyrhizobium japonicum USDA 110. The precipitation was pH dependent, with a maximum around pH 3. The precipitate was redissolved by changing the pH and by Fe3+ reduction or chelation. Deacetylation of B. japonicum polysaccharide increased its precipitation by Fe3+. At pH near neutrality, the polysaccharide from Bradyrhizobium (Chamaecytisus) strain BGA-1 stabilized Fe3+ solutions, despite the insolubility of Fe(OH)3. Aluminum precipitated Bradyrhizobium (Chamaecytisus) polysaccharide but not the polysaccharide produced by B. japonicum. The precipitation showed a maximum at about pH 4.8, and the precipitate was redissolved after Al3+ chelation with EDTA. Precipitation was inhibited by increases in the ionic strength over 10 mM. Bradyrhizobium (Chamaecytisus) polysaccharide was also precipitated by Th4+, Sn2+, Mn2+, and Co2+. The presence of Fe3+ increased the exopolysaccharide precipitation by aluminum. No precipitation, gelation, or increase in turbidity of polysaccharide solutions occurred when K+, Na+, Ca2+, Mg2+, Cu2+, Cd2+, Pb2+, Zn2+, Hg2+, or U6+ was added at several pH values. The results suggest that the precipitation is based on the interaction between carboxylate groups from different polysaccharide chains and the partially hydrolyzed aquoions of Fe3+, Al3+, Th4+, and Sn2+. PMID:16349466

  18. Performance of a pilot-scale wet electrostatic precipitator for the control of sulfuric acid mist.

    PubMed

    Huang, Jiayu; Wang, Hongmei; Shi, Yingjie; Zhang, Fan; Dang, Xiaoqing; Zhang, Hui; Shu, Yun; Deng, Shuang; Liu, Yu

    2016-10-01

    The use of a wet electrostatic precipitator (WESP) is often regarded as a viable option to reduce sulfuric acid mist emitted from the wet flue gas desulfurization (WFGD) tower in coal-fired power plants. In this study, a pilot-scale wet electrostatic precipitator equipped with a wall-cooled collection electrode is investigated for the control of sulfuric acid mist from a simulated WFGD system. The results show that due to partial charging effect, the removal efficiency of sulfuric acid aerosol decreases when the aerosol size decreases to several tens of nanometers. Moreover, due to the plasma-induced effect, a large number of ultrafine sulfuric acid aerosols below 50 nm formed at a voltage higher than 24 kV inside the WESP. The percentages of submicron-sized aerosols significantly increase together with the voltage. To minimize the adverse plasma-induced effect, a WESP should be operated at a high gas velocity with an optimum high voltage. Even at a high flue gas velocity of 2.3 m s(-1), the mass concentration and the total number concentration of uncaptured sulfuric acid aerosols at the WESP outlet are as low as ca. 0.6 mg m(-3) and ca. 10(4) 1 cm(-3) at 28 kV, respectively. The corresponding removal efficiencies were respectively higher than 99.4 and 99.9 % and are very similar to that at 1.1 and 1.6 m s(-1). Moreover, the condensation-induced aerosol growth enhances the removal of sulfuric acid mist inside a WESP and enables a low emission concentration of ca. 0.65 mg m(-3) with a corresponding removal efficiency superior to 99.4 % even at a low voltage of 21 kV, and of ca. 0.35 mg m(-3) with a corresponding removal efficiency superior to 99.6 % at a higher voltage level of 26 kV.

  19. Preparation and characterization of micronized ellagic acid using antisolvent precipitation for oral delivery.

    PubMed

    Li, Yong; Zhao, Xiuhua; Zu, Yuangang; Zhang, Yin; Ge, Yunlong; Zhong, Chen; Wu, Weiwei

    2015-01-01

    In this work, poorly water soluble phytochemical ellagic acid (EA) was micronized to increase its solubility and thereby the bioavailability during antisolvent precipitation process using N-methyl pyrrolidone (NMP) as solvent and deionized water as antisolvent. The micronized EA (m-EA) freeze-dried powder was prepared by the subsequent lyophilization process. The effects of various experimental parameters on the mean particle size (MPS) of m-EA suspension (m-EAS) in the antisolvent precipitation process were investigated. MPS and production efficiency were taken into account comprehensively to obtain the optimum conditions of antisolvent precipitation. Under the optimum conditions, m-EA freeze-dried powder with a MPS of 429.2 ± 7.6 nm was obtained. The physico-chemical properties of m-EA freeze-dried powder were detected by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), liquid chromatography-tandem mass spectrometry (LC-MS/MS), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results indicated m-EA kept the same chemical structure with raw EA, but the crystallinity was greatly reduced. Furthermore, a comparison of the 50% inhibition concentration (IC50) values revealed that m-EA was more effective than raw EA in scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Meanwhile, m-EA also showed higher reducing power. Moreover, the residual amount of NMP was lower than the International Conference on Harmonization limit (530 ppm) for solvents. The dissolution rate of m-EA was approximately 2 times of raw EA. Moreover, the solubility of m-EA was about 6.5 times of raw EA. Meanwhile, the bioavailability of m-EA increased about 2 times compared with raw EA via oral administration.

  20. Determination of trifluoroacetic acid in 1996--1997 precipitation and surface waters in California and Nevada

    SciTech Connect

    Wujcik, C.E.; Cahill, T.M.; Seiber, J.N.

    1999-05-15

    The atmospheric degradation of three chlorofluorocarbon (CFC) replacement compounds, namely HFC-134a, HCFC-123, and HCFC-124, results in the formation of trifluoroacetic acid (TFA). Concentrations of TFA were determined in precipitation and surface water samples collected in California and Nevada during 1996--1997. Terminal lake systems were found to have concentrations 4--13 times higher than their calculated yearly inputs, providing evidence for accumulation. The results support dry deposition as the primary contributor of TFA to surface waters in arid and semiarid environments. Precipitation samples obtained from three different locations contained 20.7--1530 ng/L with significantly higher concentrations in fogwater over rainwater. Elevated levels of TFA were observed for rainwater collected in Nevada over those collected in California, indicating continual uptake and concentration as clouds move from a semiarid to arid climate. Thus several mechanisms exist, including evaporative concentration, vapor-liquid phase partitioning, lowered washout volumes of atmospheric deposition water, and dry deposition, which may lead to elevated concentrations of TFA in atmospheric and surface waters above levels expected from usual rainfall washout.

  1. Purification of human immunoglobulins by sequential precipitation with caprylic acid and ammonium sulphate.

    PubMed

    Perosa, F; Carbone, R; Ferrone, S; Dammacco, F

    1990-03-27

    We have tested the usefulness of sequential precipitation with caprylic acid and ammonium sulfate to purify human monoclonal and polyclonal immunoglobulins from sera of 11 patients with monoclonal gammapathy (4 IgG kappa, 2 IgG lambda, 2 IgM kappa, 1 IgA kappa, 2 IgA lambda), four patients with autoimmune diseases and four healthy donors. In terms of purity and activity of Ig as well as execution time and cost, this two-step non-chromatographic procedure is highly efficient for the purification of IgG, IgA and IgM, thus offering several advantages over other methods of purification. Therefore, this procedure may have useful application in the preparation of human Ig for structural studies and therapeutic purposes.

  2. A study of the source-receptor relationships influencing the acidity of precipitation collected at a rural site in France

    NASA Astrophysics Data System (ADS)

    Charron, Aurélie; Plaisance, Hervé; Sauvage, Stéphane; Coddeville, Patrice; Galloo, Jean-Claude; Guillermo, René

    In order to examine the qualitative and quantitative source-receptor relationships responsible for acid rains at a background site in France, a receptor-oriented model was applied to the precipitation data collected from 1992 to 1995. Origins of acidic and alkaline species in precipitations have been investigated. The methodology combines precipitation chemical data with air parcel backward trajectories to establish concentration field maps of likely contributing sources. Highest acidities and concentrations of sulfate and nitrate in precipitation were associated with transport from the high emission areas of central Europe. Alkaline events were associated with air masses originating from Mediterranean basin or northern Africa. The quantitative relationships between the maps of potential sources and the European emissions of SO 2 and NO x were examined performing a correlation analysis. Good correlations were found between computed concentrations of acidic species and emissions of SO 2 and NO x. Substantial seasonal variations of acidic species were revealed. The highest concentrations occurred during the warm season. These seasonal variations are the effect of change of meteorological conditions and of the strength atmospheric processes according to the season.

  3. Environmental, mineralogical, and genetic characterization of ochreous and white precipitates from acid mine drainages in Taebaeg, Korea.

    PubMed

    Kim, Jeong Tin; Kim, Soo Jin

    2003-05-15

    X-ray diffraction, energy-dispersive X-ray fluorescence, thermal analysis, scanning electron microscopy, inductively coupled plasma emission spectroscopy, and ion chromatography were used for the environmental, mineralogical, and genetic characterization of brownish yellow, reddish brown, and white precipitates from acid mine drainage in Taebaeg, Korea. Ferrihydrite+goethite, schwertmannite, and Al-sulfate were precipitated under different chemical environments on the stream bottom of acid mine drainages. The brownish yellow precipitates (Munsell color 9.5YR hues) consist mainly of schwertmannite with traces of quartz, illite, pyrophyllite, goethite, lepidocrocite, and gypsum. The reddish brown precipitates (Munsell color 3.5YR hues) consist mainly of ferrihydrite with small amount of goethite. The white precipitates consist mainly of poorly crystalline Al-sulfate with small amounts of quartz, gypsum, and calcite. Thermal decomposition due to dehydration of ferrihydrite and schwertmannite takes place at approximately 120 degrees C and 140 degrees C, respectively. Al-sulfate converts to gamma-alumina at 850 degrees C. SEM study shows that the spheroid and rod-shaped precipitates characteristic of Gallionella consist of iron hydroxide with varying chemical compositions.

  4. A simple procedure for preparing chitin oligomers through acetone precipitation after hydrolysis in concentrated hydrochloric acid.

    PubMed

    Kazami, Nao; Sakaguchi, Masayoshi; Mizutani, Daisuke; Masuda, Tatsuhiko; Wakita, Satoshi; Oyama, Fumitaka; Kawakita, Masao; Sugahara, Yasusato

    2015-11-05

    Chitin oligomers are of interest because of their numerous biologically relevant properties. To prepare chitin oligomers containing 4-6 GlcNAc units [(GlcNAc)4-6], α- and β-chitin were hydrolyzed with concentrated hydrochloric acid at 40 °C. The reactant was mixed with acetone to recover the acetone-insoluble material, and (GlcNAc)4-6 was efficiently recovered after subsequent water extraction. Composition analysis using gel permeation chromatography and MALDI-TOF mass spectrometry indicated that (GlcNAc)4-6 could be isolated from the acetone-insoluble material with recoveries of approximately 17% and 21% from the starting α-chitin and β-chitin, respectively. The acetone precipitation method is highly useful for recovering chitin oligomers from the acid hydrolysate of chitin. The changes in the molecular size and higher-order structure of chitin during the course of hydrolysis were also analyzed, and a model that explains the process of oligomer accumulation is proposed.

  5. Weathering processes and pickeringite formation in a sulfidic schist: a consideration in acid precipitation neutralization studies

    SciTech Connect

    Parnell, R.A. Jr.

    1983-01-01

    Extremely low abrasion pH values (2.8-3.3) characterize the weathering products of the Partridge Formation, a Middle-Ordovician metamorphosed, black, sulfidic shale. The local occurrence is observed of two sulfates that are rare in the Northeast: pickeringite and jarosite. X-ray diffraction studies of the weathering residues and the sulfate efflorescences have also identified dioctahedral and trioctahedral illite, kaolinite, vermiculite, and an 11-12 Angstrom phase, thought to be a type of randomly-interstratified biotite-vermiculite. From the mineralogical studies, qualitative weathering processes for the schist are formulated. A probable mechanism for the intense chemical weathering of the schist appears to be oxidation of iron sulfides to form iron oxide-hydroxides, sulfates, and sulfuric acid. This natural weathering process is proposed as an analog to anthropogenic low pH rock weathering resulting from acid precipitation. In the Northeast, natural weathering rates, may, in places, significantly affect the water chemistry and mineralogy used to quantify total (natural plus anthropogenic) weathering and leaching rates. 27 references, 4 figures.

  6. [Characterization and analysis of direction extraction and precipitation of cerium loading organic phase by oxalic acid solution].

    PubMed

    Mei, Yan; Xia, Chuan; Chen, Xiao-Li; Sun, He; Nie, Zuo-Ren

    2011-11-01

    In the condition of sodium hydroxide saponification, the test results using direction extraction and precipitation of cerium from P507 loading organic phase by oxalic acid solution were studied. Infared (IR) spectrum, X-ray diffraction (XRD), transmission electron microscope (TEM) and thermogravimetry (TG-DSC) were used to study and characterize organic cerium precipitates and the final calcined products. The results showed that organic cerium precipitates and final calcined products were spheric organic cerium coordination and spheric cube CeO2 crystal, respectively, showing their morphologies were successive. IR made out that the structures of organic cerium precipitates and final calcined products were different. TG-DSC indicated that the final calcined products weightlessness was 3.5% and chemical composing was CeO2 x 1/3H2O.

  7. Chemical characteristics and sources of organic acids in precipitation at a semi-urban site in Southwest China

    NASA Astrophysics Data System (ADS)

    Zhang, Y. L.; Lee, X. Q.; Cao, F.

    2011-01-01

    In order to investigate the chemical characteristics and sources of organic acids in precipitation in Southwest China, 105 rainwater samples were collected at a semi-urban site in Anshun from June 2007 to June 2008. Organic acids and major anions were analyzed along with pH and electrical conductivity. The pH values varied from 3.57 to 7.09 for all the rainfall events sampled, with an average of 4.67 which was typical acidic value. Formic, acetic and oxalic acids were found to be the predominant carboxylic acids and their volume weighted average (VWA) concentrations were 8.77, 6.93 and 2.84 μmol l -1, respectively. These organic acids were estimated to account for 8.1% to the total free acidity (TFA) in precipitation. The concentrations of the majority organic acids at studied site had a clear seasonal pattern, reaching higher levels during the non-growing season than those in growing season, which was attributed to dilution effect of heavy rainfall during the growing season. The seasonal variation of wet deposition flux of these organic acids confirmed higher source strength of biogenic emissions from vegetation during the growing season. Formic-to-acetic acids ratio (F/A), an indicator of primary versus secondary sources of these organic acids, suggested that primary sources from vehicular emission, biomass burning, soil and vegetation emissions were dominant sources. In addition, the lowest concentrations of organic acids were found under type S, when air masses originated from the marine (South China Sea) during Southern Asian Monsoon period. And the highest concentrations were observed in precipitation events from Northeast China (type NE), prevailing mostly during winter with the lowest rainfall.

  8. Both forward and reverse TCA cycles operate in green sulfur bacteria.

    PubMed

    Tang, Kuo-Hsiang; Blankenship, Robert E

    2010-11-12

    The anoxygenic green sulfur bacteria (GSBs) assimilate CO(2) autotrophically through the reductive (reverse) tricarboxylic acid (RTCA) cycle. Some organic carbon sources, such as acetate and pyruvate, can be assimilated during the phototrophic growth of the GSBs, in the presence of CO(2) or HCO(3)(-). It has not been established why the inorganic carbonis required for incorporating organic carbon for growth and how the organic carbons are assimilated. In this report, we probed carbon flux during autotrophic and mixotrophic growth of the GSB Chlorobaculum tepidum. Our data indicate the following: (a) the RTCA cycle is active during autotrophic and mixotrophic growth; (b) the flux from pyruvate to acetyl-CoA is very low and acetyl-CoA is synthesized through the RTCA cycle and acetate assimilation; (c) pyruvate is largely assimilated through the RTCA cycle; and (d) acetate can be assimilated via both of the RTCA as well as the oxidative (forward) TCA (OTCA) cycle. The OTCA cycle revealed herein may explain better cell growth during mixotrophic growth with acetate, as energy is generated through the OTCA cycle. Furthermore, the genes specific for the OTCA cycle are either absent or down-regulated during phototrophic growth, implying that the OTCA cycle is not complete, and CO(2) is required for the RTCA cycle to produce metabolites in the TCA cycle. Moreover, CO(2) is essential for assimilating acetate and pyruvate through the CO(2)-anaplerotic pathway and pyruvate synthesis from acetyl-CoA.

  9. Integrated Lake-Watershed Acidification Study (ILWAS): contributions to the international conference on the ecological impact of acid precipitation

    SciTech Connect

    Not Available

    1981-05-01

    The Integrated Lake-Watershed Acidification Study (ILWAS) was initiated to study and detail lake acidification processes for three lake watershed basins in the Adirondack Park region of New York. The three basins (Woods, Sagamore, and Panther), receive similar amounts of acid deposition yet observable pH values for the lakes are very dissimilar indicating unequal acid neutralizing capacities among the watersheds. This volume contains a compilation of seven papers. Relevant topics include: a characterization of the geology, hydrology, limnology and vegetation of the three study sites, an analysis of acid precipitation quality and quantity, the effects of vegetative canopy, the effects of snowmelt, the effects of winter lake stratification, comparison of heavy metal transport, examination of acidic sources other than direct precipitation, assessment of lake acidification during spring thaw and integration of all acidification components with a mathematical model.

  10. [Low molecular weight carboxylic acids in precipitation during the rainy season in the rural area of Anshun, West Guizhou Province].

    PubMed

    Zhang, Yan-Lin; Lee, Xin-Qing; Huang, Dai-Kuan; Huang, Rong-Sheng; Jiang, Wei

    2009-03-15

    40 rainwater samples were collected at Anshun from June 2007 to October 2007 and analysed in terms of pH values, electrical conductivity, major inorganic anions and soluble low molecular weight carboxylic acids. The results showed that pH of individual precipitation events ranged from 3.57-7.09 and the volume weight mean pH value was 4.57. The most abundant carboxylic acids were acetic (volume weight mean concentration 6.75 micromol x L(-1)) and formic (4.61 micromol x L(-1)) followed by oxalic (2.05 micromol x L(-1)). The concentration levels for these three species during summer especially June and July were comparatively high; it implied that organic acids in Anshun may came primarily from emissions from growing vegetations or products of the photochemical reactions of unsaturated hydrocarbons. Carboxylic acids were estimated to account for 32.2% to the free acidity in precipitation. The contribution was higher than in Guiyang rainwater, which indicated contamination by industry in Guiyang was more than in Anshun. The remarkable correlation(p = 0.01) between formic acid and acetic acid suggest that they have similar sources or similar intensity but different sources. And the remarkable correlation (p = 0.01) between and formic acid and oxalic acid showed that the precursors of oxalic acid and formic acid had similar sources. During this period, the overall wet deposition of carboxylic acids were 2.10 mmol/m2. And it appeared mainly in the summer, during which both concentration and contribution to free acidity were also relatively high. Consequently, it was necessary to control emission of organic acids in the summer to reduce frequence of acid rain in Anshun.

  11. Comparison of haloacetic acids in the environment of the Northern and Southern Hemispheres.

    PubMed

    Scott, B F; Spencer, C; Martin, J W; Barra, R; Bootsma, H A; Jones, K C; Johnston, A E; Muir, D C G

    2005-11-15

    Haloacetic acids (HAAs) are a family of compounds whose environmental concentrations have been extensively studied, primarily in Europe. Depending on the compound, their sources are believed to be both natural and anthropogenic. To better understand possible sources and contribute to the knowledge of the global distribution of these compounds, especially between the Northern and Southern Hemispheres, samples of precipitation, soils, and conifer needles were collected from Canada, Malawi, Chile, and the U.K. Precipitation samples exhibited highest HAA concentrations in collections from Canada, and lowest in those from Malawi. Malawi samples contained measurable levels of monobromoacetic acid (MBA) (56 ng/ L) unlike those from most other locations (< 9 ng/L). Soil HAA concentration levels were highest in the U.K. (e.g., 7.3 ng/g average TCA) and lowest in Malawi (0.8 ng/g average TCA), with Chile having higher levels (4.8 ng/g average TCA) than Canada (3 ng/g average TCA). Malawi soils contained small amounts of MBA (2 ng/g), in common with the two most southern of the 11 Chilean sites. Analysis of soil cores (10-cm depth sliced at 1 cm) from sites in Malawi and Chile showed that trichloroacetic acid (TCA) generally declined with depth while mono- and dichloroacetic acid (MCA and DCA) showed no trend. MCA, DCA, and TCA concentrations in archived U.K. soil samples increased by factors of 2, 4, and 5-fold over 75 years while TFA showed no consistent trend. Monochloroacetic acid (MCA) was detected in pine needles collected from Malawi. U.K. needle samples had the highest concentrations of all chloroacetic acids (CAAs): MCA, 2-18 ng/g; dichloroacetic acid (DCA), 2-38 ng/g; and trichloroacetic acid (TCA), 28-190 ng/g. Conifer needles from Canada and Chile contained CAAs at levels ranging from < 2 to 16 ng/g wet wt. Trifluoroacetic acid concentrations generally declined with increasing elevation in the samples from the Rocky Mountains in western Canada. The results

  12. Anaerobic respiration using a complete oxidative TCA cycle drives multicellular swarming in Proteus mirabilis.

    PubMed

    Alteri, Christopher J; Himpsl, Stephanie D; Engstrom, Michael D; Mobley, Harry L T

    2012-10-30

    Proteus mirabilis rapidly migrates across surfaces using a periodic developmental process of differentiation alternating between short swimmer cells and elongated hyperflagellated swarmer cells. To undergo this vigorous flagellum-mediated motility, bacteria must generate a substantial proton gradient across their cytoplasmic membranes by using available energy pathways. We sought to identify the link between energy pathways and swarming differentiation by examining the behavior of defined central metabolism mutants. Mutations in the tricarboxylic acid (TCA) cycle (fumC and sdhB mutants) caused altered patterns of swarming periodicity, suggesting an aerobic pathway. Surprisingly, the wild-type strain swarmed on agar containing sodium azide, which poisons aerobic respiration; the fumC TCA cycle mutant, however, was unable to swarm on azide. To identify other contributing energy pathways, we screened transposon mutants for loss of swarming on sodium azide and found insertions in the following genes that involved fumarate metabolism or respiration: hybB, encoding hydrogenase; fumC, encoding fumarase; argH, encoding argininosuccinate lyase (generates fumarate); and a quinone hydroxylase gene. These findings validated the screen and suggested involvement of anaerobic electron transport chain components. Abnormal swarming periodicity of fumC and sdhB mutants was associated with the excretion of reduced acidic fermentation end products. Bacteria lacking SdhB were rescued to wild-type pH and periodicity by providing fumarate, independent of carbon source but dependent on oxygen, while fumC mutants were rescued by glycerol, independent of fumarate only under anaerobic conditions. These findings link multicellular swarming patterns with fumarate metabolism and membrane electron transport using a previously unappreciated configuration of both aerobic and anaerobic respiratory chain components. Bacterial locomotion and the existence of microbes were the first scientific

  13. [Formation and environmental implications of iron-enriched precipitates derived from natural neutralization of acid mine drainage].

    PubMed

    Zhou, Yue-Fei; Xie, Yue; Zhou, Li-Xiang

    2010-06-01

    Acid mine drainage (AMD) and its natural neutralizing products in Wangjiatan iron mine were collected and analyzed by using spectroscopic and electron microanalytic methods. The results show that after natural neutralization of AMD by surface water of the stream, acidity and electric conductivity of AMD are both decreased. While for dissolved elements, no other element is obviously decreased except for Fe3+, SO4(2-), and Ca2+. For precipitates formed by natural neutralization, Fe is enriched and ferrihydrite is the main iron mineral, with little amount of goethite and fibroferrite contained in downstream precipitates. To ferrihydrite, 2-line and 6-line ferrihydrite are the main mineral type in upstream and downstream precipitates, respectively. Furthermore, for all precipitates, two layers are observed. In outer layer 2-line ferrihydrite is the main mineral, while in inner layer 6-line ferrihydrite and goethite are the main minerals. Ferrihydrite dominated precipitates are favorable in immobilizing toxic and hazardous elements. Furthermore, it is demonstrated that pH and the concentration of SO4(2-) are decisive factors for ferrihydrite formation. The ferrihydrite translocation and its attenuation for toxic elements are, to a great extent, affected by hydrodynamics in neutralization zone.

  14. Comparison of Four Strong Acids on the Precipitation Potential of Gypsum in Brines During Distillation of Pretreated, Augmented Urine

    NASA Technical Reports Server (NTRS)

    Muirhead, Dean; Carrier, Christopher

    2012-01-01

    In this study, three different mineral acids were substituted for sulfuric acid (H2SO4) in the urine stabilizer solution to eliminate the excess of sulfate ions in pretreated urine and assess the impact on maximum water recovery to avoid precipitation of minerals during distillation. The study evaluated replacing 98% sulfuric acid with 85% phosphoric acid (H3PO4), 37% hydrochloric acid (HCl), or 70% nitric acid (HNO3). The effect of lowering the oxidizer concentration in the pretreatment formulation also was studied. This paper summarizes the test results, defines candidate formulations for further study, and specifies the injection masses required to stabilize urine and minimize the risk of mineral precipitation during distillation. In the first test with a brine ersatz acidified with different acids, the solubility of calcium in gypsum saturated solutions was measured. The solubility of gypsum was doubled in the brines acidified with the alternative acids compared to sulfuric acid. In a second series of tests, the alternative acid pretreatment concentrations were effective at preventing precipitation of gypsum and other minerals up to 85% water recovery from 95th-percentile pretreated, augmented urine. Based on test results, phosphoric acid is recommended as the safest alternative to sulfuric acid. It also is recommended that the injected mass concentration of chromium trioxide solution be reduced by 75% to minimize liquid resupply mass by about 50%, reduce toxicity of brines, and reduce the concentration of organic acids in distillate. The new stabilizer solution formulations and required doses to stabilize urine and prevent precipitation of minerals up to 85% water recovery are given. The formulations in this study were tested on a limited number of artificially augmented urine batches collected from employees at the Johnson Space Center (JSC). This study successfully demonstrated that the desired physical and chemical stability of pretreated urine and brines

  15. Geological and hydrochemical sensitivity of the eastern United States to acid precipitation

    SciTech Connect

    Hendrey, G.R.; Galloway, J.N.; Norton, S.A.; Schofield, C.L.; Shaffer, P.W.; Burns, D.A.

    1980-03-01

    A new analysis of bedrock geology maps of the eastern US constitutes a simple model for predicting areas which might be impacted by acid precipitation and it allows much greater resolution for detecting sensitivity than has previously been available for the region. Map accuracy has been verified by examining current alkalinities and pH's of waters in several test states, including Maine, New Hampshire, New York, Virginia and North Carolina. In regions predicted to be highly sensitive, alkalinities in upstream sites were generally low. Many areas of the eastern US are pinpointed in which some of the surface waters, especially upstream reaches, may be sensitive to acidification. Pre-1970 data were compared to post-1975 data, revealing marked declines in both alkalinity and pH of sensitive waters of two states tested, North Carolina, where pH and alkalinity have decreased in 80% of 38 streams and New Hampshire, where pH in 90% of 49 streams and lakes has decreased since 1949. These sites are predicted to be sensitive by the geological map on the basis of their earlier alkalinity values. The map is to be improved by the addition of a soils component.

  16. Selective recovery of soil-borne metal contaminants through integrated solubilization by biogenic sulfuric acid and precipitation by biogenic sulfide.

    PubMed

    Fang, Di; Zhang, Ruichang; Liu, Xue; Zhou, Lixiang

    2012-06-15

    A hybrid process combining solubilization via sulfuric acid produced by sulfur-oxidizing bacteria with precipitation via sulfide produced by sulfate-reducing bacteria was investigated to isolate soil-borne metal contaminants as purified metal-sulfides. The highly efficient two-step acidification process involved bioproduction of sulfuric acid in a culture medium containing 30% (v/v) of sludge filtrate (SF). Soil was added to the culture after maximum acid production. Solubilization efficiencies of 95% for Zn, 76% for Cu and 97% for Cd were achieved after 16 days. At pH 1.9, 3.0 and 4.0, 99% of Cu(2+), 96% of Cd(3+) and 93% of Zn(2+), respectively, were precipitated from the soil leachate by sulfide transported from sulfidogenic bioreactor via N(2) sparging, resulting in final effluent metal contents at the ppb-level. The introduction of SF did not affect the precipitation kinetics and purity of the recovered precipitates. Ultimately, 75% of Cu and 86% of Zn were recovered from the soil as pure CuS and ZnS (confirmed by SEM-EDS and XRD). These results demonstrate the potential of the integrated method for the selective production of valuable metals from metal contamination in soils.

  17. Historic volcanism, European dry fogs, and greenland Acid precipitation, 1500 B.C. To a.d. 1500.

    PubMed

    Stothers, R B; Rampino, M R

    1983-10-28

    Historic dry fogs in Europe, acid precipitation in Greenland, and major explosive volcanic eruptions correlate well with each other between 1500 B.C. and A.D. 1500. European (Mediterranean and Icelandic) volcanic eruptions appear to be the source of at least five of the nine largest acidity signals found in Greenland ice for this period. Between 152 B.C. and A.D. 43, eruptions of sulfur-rich Mount Etna probably supplied about 15 percent of the smaller acidity signals.

  18. Survival of Listeria innocua in rainbow trout protein recovered by isoelectric solubilization and precipitation with acetic and citric acids.

    PubMed

    Otto, R A; Paker, I; Bane, L; Beamer, S; Jaczynski, J; Matak, K E

    2011-08-01

    During mechanical fish processing, a substantial amount of protein is discarded as by-products. Isoelectric solubilization and precipitation (ISP) is a process that uses extreme pH shifts to solubilize and precipitate protein from by-products to recover previously discarded protein. Typically, strong acids are used for pH reduction, but these acids do not have a pasteurization effect (6 log reduction) on bacterial load; therefore, organic acids were used during ISP processing to test the impact on Listeria innocua concentrations. Headed and gutted rainbow trout (Oncorhynchus mykiss) were inoculated with L. innocua, homogenized, and brought to the target pH with granular citric acid (pH 2.0 and 2.5) or glacial acetic acid (pH 3.0 and 3.5). Proteins were solubilized for 10 min at 4°C, and insoluble components (e.g., skin and insoluble protein) were removed by centrifugation. The remaining solution was pH shifted to the protein isoelectric point (pH 5.5) with sodium hydroxide, and precipitated protein was separated from the water. Microbial cells for each component (proteins, insolubles, and water) were enumerated on modified Oxford agar (MOX) and tryptic soy agar with 6% yeast extract (TSAYE). The sums of the surviving cells from each component were compared with the initial inoculum levels. No significant differences were observed between results obtained from TSAYE and from MOX (P > 0.05). Significant reductions in microbial populations were detected, regardless of pH or acid type (P < 0.05). The greatest reduction was at pH 3.0 with glacial acetic acid, resulting in a mean reduction of 6.41 log CFU/g in the recovered protein and 5.88 log CFU/g in the combined components. These results demonstrate the antimicrobial potential of organic acids in ISP processing.

  19. Reductive photo-dechlorination (RPD) technology for remediation of TCA

    SciTech Connect

    Lavid, M.; Gulati, S.K.; Teytelboym, M.

    1994-12-31

    The Reductive Photo-Dechlorination (RPD) technology uses ultraviolet light in a reducing atmosphere to remove chlorine atoms from organo-chlorine waste streams at low to moderate temperatures. Because chlorinated organics are destroyed in a reducing environment, process products include valuable hydrocarbons and hydrogen chloride with no toxic oxygenated chlorocarbon by-products. The RPD process is designed specifically to treat volatile chlorinated wastes in the liquid or gaseous phases. Field applications include organic wastes produced from soil venting operations and those adsorbed on activated carbon. The process can also be used to pretreat gas streams entering catalytic oxidation systems, reducing chlorine content and hereby protecting the catalyst against poisoning. This paper focuses on photo-thermal remediation of 1,1,1-trichloroethane (TCA). It describes bench-scale experimental results, kinetic modeling predictions, and selected design parameters for a pilot-scale demonstration.

  20. WACCM-D—Improved modeling of nitric acid and active chlorine during energetic particle precipitation

    NASA Astrophysics Data System (ADS)

    Andersson, M. E.; Verronen, P. T.; Marsh, D. R.; Päivärinta, S.-M.; Plane, J. M. C.

    2016-09-01

    Observations have shown that a number of neutral minor species are affected by energetic particle precipitation (EPP) and ion chemistry (IC) in the polar regions. However, to date the complexity of the ion chemistry below the mesopause (i.e., in the D region ionosphere) has restricted global models to simplified EEP/IC parameterizations which are unable to reproduce some important effects, e.g., the increase of mesospheric nitric acid (HNO3). Here we use WACCM-D, a variant of the Whole Atmosphere Community Climate Model which includes a selected set of D region ion chemistry designed to produce the observed effects of EPP/IC. We evaluate the performance of EPP/IC modeling by comparing WACCM-D results for the January 2005 solar proton event (SPE) to those from the standard WACCM and Aura/Microwave Limb Sounder (MLS) and SCISAT/Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) observations. The results indicate that WACCM-D improves the modeling of HNO3, HCl, ClO, OH, and NOx during the SPE. Northern Hemispheric HNO3 from WACCM-D shows an increase by 2 orders of magnitude at 40-70 km compared to WACCM, reaching 2.6 ppbv, in agreement with the observations. For HCl and ClO, the improvement is most pronounced in the Southern Hemisphere at 40-50 km where WACCM-D predicts a decrease of HCl and increase of ClO by 1.6% and 10%, respectively, similar to MLS data. Compared to WACCM, WACCM-D produces 25-50% less OH and 30-130% more NOx at 70-85 km which leads to better agreement with the observations. Although not addressed here, longer-term NOx impact of ion chemistry could be important for polar stratospheric ozone and middle atmospheric dynamics.

  1. Potential effects of clean coal technologies on acid precipitation, greenhouse gases, and solid waste disposal

    SciTech Connect

    Blasing, T.J.; Miller, R.L.; McCold, L.N.

    1993-11-01

    The US Department of Energy`s (DOE`s) Clean Coal Technology Demonstration Program (CCTDP) was initially funded by Congress to demonstrate more efficient, economically feasible, and environmentally acceptable coal technologies. Although the environmental focus at first was on sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) because their relationship to acid precipitation, the CCTDP may also lead to reductions in carbon dioxide (CO{sub 2}) emissions and in the volume of solid waste produced, compared with conventional technologies. The environmental effects of clean coal technologies (CCTs) depend upon which (if any) specific technologies eventually achieve high acceptance in the marketplace. In general, the repowering technologies and a small group of retrofit technologies show the most promise for reducing C0{sub 2} emissions and solid waste. These technologies also compare favorably with other CCTs in terms of SO{sub 2} and NO{sub x} reductions. The upper bound for CO{sup 2} reductions in the year 2010 is only enough to reduce global ``greenhouse`` warming potential by about 1%. However, CO{sub 2} emissions come from such variety of sources around the globe that no single technological innovation or national policy change could realistically be expected to reduce these emissions by more than a few percent. Particular CCTs can lead to either increases or decreases in the amount of solid waste produced. However, even if decreases are not achieved, much of the solid waste from clean coal technologies would be dry and therefore easier to dispose of than scrubber sludge.

  2. Particle size tailoring of ursolic acid nanosuspensions for improved anticancer activity by controlled antisolvent precipitation.

    PubMed

    Wang, Yancai; Song, Ju; Chow, Shing Fung; Chow, Albert H L; Zheng, Ying

    2015-10-15

    The present study was aimed at tailoring the particle size of ursolic acid (UA) nanosuspension for improved anticancer activity. UA nanosuspensions were prepared by antisolvent precipitation using a four-stream multi-inlet vortex mixer (MIVM) under defined conditions of varying solvent composition, drug feeding concentration or stream flow rate. The resulting products were characterized for particle size and polydispersity. Two of the UA nanosuspensions with mean particle sizes of 100 and 300 nm were further assessed for their in-vitro activity against MCF-7 breast cancer cells using fluorescence microscopy with 4',6-diamidino-2-phenylindole (DAPI) staining, as well as flow cytometry with propidium (PI) staining and with double staining by fluorescein isothiocyanate. It was revealed that the solvent composition, drug feeding concentration and stream flow rate were critical parameters for particle size control of the UA nanosuspensions generated with the MIVM. Specifically, decreasing the UA feeding concentration or increasing the stream flow rate or ethanol content resulted in a reduction of particle size. Excellent reproducibility for nanosuspension production was demonstrated for the 100 and 300 nm UA preparations with a deviation of not more than 5% in particle size from the mean value of three independent batches. Fluorescence microscopy and flow cytometry revealed that these two different sized UA nanosuspensions, particularly the 300 nm sample, exhibited a higher anti-proliferation activity against the MCF-7 cells and afforded a larger population of these cells in both early and late apoptotic phases. In conclusion, MIVM is a robust and pragmatic tool for tailoring the particle size of the UA nanosuspension. Particle size appears to be a critical determinant of the anticancer activity of the UA nanoparticles.

  3. STRONTIUM PRECIPITATION

    DOEpatents

    McKenzie, T.R.

    1960-09-13

    A process is given for improving the precipitation of strontium from an aqueous phosphoric-acid-containing solution with nickel or cobalt ferrocyanide by simultaneously precipitating strontium or calcium phosphate. This is accomplished by adding to the ferrocyanide-containing solution calcium or strontium nitrate in a quantity to yield a concentration of from 0.004 to 0.03 and adjusting the pH of the solution to a value of above 8.

  4. Stepwise ethanolic precipitation of sugar beet pectins from the acidic extract.

    PubMed

    Guo, Xiaoming; Meng, Hecheng; Zhu, Siming; Tang, Qiang; Pan, Runquan; Yu, Shujuan

    2016-01-20

    A stepwise ethanol-precipitation (SEP) procedure was developed for the purification of sugar beet pectins (SBP) from a pectin-containing aqueous extract. Five fractions of different chemical and molecular characteristics were produced by stepwise elevating the alcohol concentration of the precipitation medium from 50% to 80% v/v. Comparison of chemical and macromolecular features between the obtained fractions indirectly suggested that the ability of pectin to solubilize in the ethanol-water binary mixture depended greatly on the polymer structure. Fractions rich in neutral sugars were precipitated at relatively high ethanol concentrations, probably due to the enhanced interactions generated between pectin side chains and solvent molecules. Furthermore, the obtained fractions displayed different surface activities. Results obtained in this work indicate that the SEP procedure is more selective with respect to pectin structural features and surface properties than the one-step ethanolic precipitation.

  5. Advances in biotreatment of acid mine drainage and biorecovery of metals: 1. Metal precipitation for recovery and recycle.

    PubMed

    Tabak, Henry H; Scharp, Richard; Burckle, John; Kawahara, Fred K; Govind, Rakesh

    2003-12-01

    Acid mine drainage (AMD), an acidic metal-bearing wastewater, poses a severe pollution problem attributed to post mining activities. The metals usually encountered in AMD and considered of concern for risk assessment are arsenic, cadmium, iron, lead, manganese, zinc, copper and sulfate. The pollution generated by abandoned mining activities in the area of Butte, Montana has resulted in the designation of the Silver Bow Creek-Butte Area as the largest Superfund (National Priorities List) site in the U.S. This paper reports the results of bench-scale studies conducted to develop a resource recovery based remediation process for the clean up of the Berkeley Pit. The process utilizes selective, sequential precipitation (SSP) of metals as hydroxides and sulfides, such as copper, zinc, aluminum, iron and manganese, from the Berkeley Pit AMD for their removal from the water in a form suitable for additional processing into marketable precipitates and pigments. The metal biorecovery and recycle process is based on complete separation of the biological sulfate reduction step and the metal precipitation step. Hydrogen sulfide produced in the SRB bioreactor systems is used in the precipitation step to form insoluble metal sulfides. The average metal recoveries using the SSP process were as follows: aluminum (as hydroxide) 99.8%, cadmium (as sulfide) 99.7%, cobalt (as sulfide) 99.1% copper (as sulfide) 99.8%, ferrous iron (sulfide) 97.1%, manganese (as sulfide) 87.4%, nickel (as sulfide) 47.8%, and zinc (as sulfide) 100%. The average precipitate purity for metals, copper sulfide, ferric hydroxide, zinc sulfide, aluminum hydroxide and manganese sulfide were: 92.4, 81.5, 97.8, 95.6, 92.1 and 75.0%, respectively. The final produced water contained only calcium and magnesium and both sulfate and sulfide concentrations were below usable water limits. Water quality of this agriculturally usable water met the EPA's gold standard criterion.

  6. Blocking anaplerotic entry of glutamine into the TCA cycle sensitizes K-Ras mutant cancer cells to cytotoxic drugs.

    PubMed

    Saqcena, M; Mukhopadhyay, S; Hosny, C; Alhamed, A; Chatterjee, A; Foster, D A

    2015-05-14

    Cancer cells undergo a metabolic transformation that allows for increased anabolic demands, wherein glycolytic and tricarboxylic acid (TCA) cycle intermediates are shunted away for the synthesis of biological molecules required for cell growth and division. One of the key shunts is the exit of citrate from the mitochondria and the TCA cycle for the generation of cytosolic acetyl-coenzyme A that can be used for fatty acid and cholesterol biosynthesis. With the loss of mitochondrial citrate, cancer cells rely on the 'conditionally essential' amino acid glutamine (Q) as an anaplerotic carbon source for TCA cycle intermediates. Although Q deprivation causes G1 cell cycle arrest in non-transformed cells, its impact on the cancer cell cycle is not well characterized. We report here a correlation between bypass of the Q-dependent G1 checkpoint and cancer cells harboring K-Ras mutations. Instead of arresting in G1 in response to Q-deprivation, K-Ras-driven cancer cells arrest in either S- or G2/M-phase. Inhibition of K-Ras effector pathways was able to revert cells to G1 arrest upon Q deprivation. Blocking anaplerotic utilization of Q mimicked Q deprivation--causing S- and G2/M-phase arrest in K-Ras mutant cancer cells. Significantly, Q deprivation or suppression of anaplerotic Q utilization created synthetic lethality to the cell cycle phase-specific cytotoxic drugs, capecitabine and paclitaxel. These data suggest that disabling of the G1 Q checkpoint could represent a novel vulnerability of cancer cells harboring K-Ras and possibly other mutations that disable the Q-dependent checkpoint.

  7. Pyridine-2,6-bis(thiocarboxylic acid) produced by Pseudomonas stutzeri KC reduces and precipitates selenium and tellurium oxyanions.

    PubMed

    Zawadzka, Anna M; Crawford, Ronald L; Paszczynski, Andrzej J

    2006-05-01

    The siderophore of Pseudomonas stutzeri KC, pyridine-2,6-bis(thiocarboxylic acid) (pdtc), is shown to detoxify selenium and tellurium oxyanions in bacterial cultures. A mechanism for pdtc's detoxification of tellurite and selenite is proposed. The mechanism is based upon determination using mass spectrometry and energy-dispersive X-ray spectrometry of the chemical structures of compounds formed during initial reactions of tellurite and selenite with pdtc. Selenite and tellurite are reduced by pdtc or its hydrolysis product H(2)S, forming zero-valent pdtc selenides and pdtc tellurides that precipitate from solution. These insoluble compounds then hydrolyze, releasing nanometer-sized particles of elemental selenium or tellurium. Electron microscopy studies showed both extracellular precipitation and internal deposition of these metalloids by bacterial cells. The precipitates formed with synthetic pdtc were similar to those formed in pdtc-producing cultures of P. stutzeri KC. Culture filtrates of P. stutzeri KC containing pdtc were also active in removing selenite and precipitating elemental selenium and tellurium. The pdtc-producing wild-type strain KC conferred higher tolerance against selenite and tellurite toxicity than a pdtc-negative mutant strain, CTN1. These observations support the hypothesis that pdtc not only functions as a siderophore but also is involved in an initial line of defense against toxicity from various metals and metalloids.

  8. Effects of airborne particulate matter on the acidity of precipitation in central Missouri

    SciTech Connect

    Applin, K.R.

    1985-01-01

    The pH of rainfall in central Missouri was monitored at four sites during the fall of 1983. Several pH values were well above 5.6, the theoretical pH of pure water in equilibrium with ambient levels of CO/sub 2/. Most of the higher pH's were measured on rainfall of short duration or rainfall collected during the first few hours of extended rainfall events. Furthermore, the rainfall associated with storm events lasting several days exhibited a trend of decreasing pH with time approaching values as low as 4.0 during the late stages of rainfall. Precipitation pH values above 5.6 apparently reflect neutralization reactions between wet precipitation and various components of airborne dust, especially clays and carbonates. During extended rainfalls, the neutralization effects gradually diminish as suspended dust is washed from the atmosphere yielding more accurate values of the wet precipitation pH. The results of this study suggest that airborne particulate matter generated from the dust bowl region of the US may affect the chemistry of precipitation in areas hundreds of kilometers downwind. Using date available in the literature, a direct relationship between precipitation pH and accumulated dustfall was found for data taken along a transect which represents the path of major storms crossing the US, i.e., from the south-central to northeastern regions.

  9. Dissolved, particulate and acid-leachable trace metal concentrations in North Atlantic precipitation collected on the Global Change Expedition

    SciTech Connect

    Lim, B.; Jickells, T.D. )

    1990-12-01

    Atmospheric inputs of trace metals into surface waters are an important pathway for the oceanic biogeochemical cycling of many trace constituents. Rainwater samples from six precipitation events were collected on board ship during legs 3 and 4 of the Global Change Expedition over the North Atlantic Ocean and analyzed for dissolved, particulate (Al and Pb), and acid-leachable trace metals (Al, Fe, Mn, Cd, Cu, Pb, Zn). Acid-leachable concentrations of the elements were similar to reported values from the North Atlantic and Pacific Oceans which were measured using comparable acidification procedures. Concentrations of dissolved and particulate Al and Pb were determined in rain events acid-leachable and total trace metal concentrations suggest that the acid-leachable fraction of metals can significantly underestimate total concentrations of crustal elements in rain. The solubilities of Al and Pb in precipitation were variable and mean solubilities of the elements were 13% and 45%, respectively. Recycled sea salt components were less than 14% for Al, Fe, Mn, Pb, Cd, Cu, and Zn, indicating that the net trace metal flux is from the atmosphere to the oceans. Deep sea particle fluxes for these metals through the western tropical North Atlantic exceed atmospheric deposition fluxes by a factor of 18 to 41. 57 refs., 2 figs., 12 tabs.

  10. Adsorption and co-precipitation behavior of arsenate, chromate, selenate and boric acid with synthetic allophane-like materials.

    PubMed

    Opiso, Einstine; Sato, Tsutomu; Yoneda, Tetsuro

    2009-10-15

    Pollution caused by boric acid and toxic anions such as As(V), Cr(VI) and Se(VI) is hazardous to human health and environment. The sorption characteristics of these environmentally significant ionic species on allophane-like nanoparticles were investigated in order to determine whether allophane can reduce their mobility in the subsurface environment at circum-neutral pH condition. Solutions containing 100 or 150 mmol of AlCl(3)x6H(2)O were mixed to 100 mmol of Na(4)SiO(4) and the pH were adjusted to 6.4+/-0.3. The mineral suspensions were shaken for 1h and incubated at 80 degrees C for 5 days. Appropriate amounts of As, B, Cr and Se solutions were added separately during and after allophane precipitation. The results showed that As(V) and boric acid can be irreversibly fixed during co-precipitation in addition to surface adsorption. However, Cr(VI) and Se(VI) retention during and after allophane precipitation is mainly controlled by surface adsorption. The structurally fixed As(V) and boric acid were more resistant to release than those bound on the surface. The sorption characteristics of oxyanions and boric acid were also influenced by the final Si/Al molar ratio of allophane in which Al-rich allophane tend to have higher uptake capacity. The overall results of this study have demonstrated the role of allophane-like nanoparticles and the effect of its Si/Al ratio on As, B, Cr and Se transport processes in the subsurface environment.

  11. Quantifying foliar responses of white ash to ozone and simulated acid precipitation: An assessment proposal for forest exposure studies. Forest Service research paper. (Final)

    SciTech Connect

    Dochinger, L.S.; Jensen, K.F.

    1990-04-01

    Seedlings populations represent an important linkage for assessing the effect of air pollution on forests. The study examines the foliar responses of white ash seedlings to ozone and acid precipitation as a means of identifying atmospheric deposition effects on forests.

  12. Electron micrographic study of precipitates formed by interaction of silicic acid and alkaline phosphatase: contribution to a study of silica urolithiasis in cattle.

    PubMed

    Bailey, C B; Cheng, K J; Costerton, J W

    1982-12-01

    Association of alkaline phosphatase with silicic acid in precipitates formed in dilute solution was studied as a model for the nonspecific reaction between silicic acid and protein. Precipitates contained 68-83% of the silicic acid and 52-83% of the enzyme in the original mixture and were in the form of aggregates of roundish particles 150-800 nm in diameter. Enzyme protein formed a tightly bound layer on the surface of particles formed in solutions of freshly prepared silicic acid. The similarity between the ultrastructural features of precipitates from solutions of silicic acid and of internal portions of siliceous urinary calculi from cattle suggests that deposition of silica during development of such calculi is due, at least in part, to the interaction of protein with silicic acid in urine.

  13. Precipitation of jarosite-type double salts from spent acid solutions from a chemical coal cleaning process

    SciTech Connect

    Norton, G.

    1990-09-21

    The precipitation of jarosite compounds to remove Na, K, Fe, and SO{sub 4}{sup 2{minus}} impurities from spent acid solutions from a chemical coal cleaning process was studied. Simple heating of model solutions containing Fe{sub 2}(SO{sub 4}){sub 3}, Na{sub 2}SO{sub 4}, and K{sub 2}SO{sub 4} caused jarosite (KFe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}) to form preferentially to natrojarosite (NaFe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}). Virtually all of the K, about 90% of the Fe, and about 30% of the SO{sub 4}{sup 2{minus}} could be precipitated from those solutions at 95{degree}C, while little or no Na was removed. However, simple heating of model solutions containing only Fe{sub 2}(SO{sub 4}){sub 3} and Na{sub 2}SO{sub 4} up to 95{degree}C for {le}12 hours produced low yields of jarosite compounds, and the Fe concentration in the solution had to be increased to avoid the formation of undesirable Fe compounds. Precipitate yields could be increased dramatically in model solutions of Na{sub 2}SO{sub 4}/Fe{sub 2}(SO{sub 4}){sub 3} containing excess Fe by using either CaCO{sub 3}, Ca(OH){sub 2}, or ZnO to neutralize H{sub 2}SO{sub 4} released during hydrolysis of the Fe{sub 2}(SO{sub 4}){sub 3} and during the precipitation reactions. Results obtained from the studies with model solutions were applied to spent acids produced during laboratory countercurrent washing of coal which had been leached with a molten NaOH/KOH mixture. Results indicated that jarosite compounds can be precipitated effectively from spent acid solutions by heating for 6 hours at 80{degree}C while maintaining a pH of about 1.5 using CaCO{sub 3}.

  14. Preliminary Results of the 1.5% TCA (Modular) Controls Model in the NASA Langley UPWT

    NASA Technical Reports Server (NTRS)

    Kubiatko, Paul; McMillin, Naomi; Cameron, Douglas C.

    1999-01-01

    To summarize the significant highlights in this report: (1) Data quality, determined by multiple repeat runs performed on the TCA baseline configuration, and long-term repeatability, determined by comparing baseline Reference H data from this test to a previous test, have been shown to be good. (2) The longitudinal stability of the TCA is more non-linear than for the Reference H, and while it is similar at normal lift values, the TCA has considerably more pitch-up at higher lift. (3) Longitudinal control effectiveness of the TCA is similar to the Reference H and the ratio of elevator effectiveness to horizontal tail effectiveness is approximately 0.3. 4) The directional stability of the TCA is improved relative to Reference H at higher angles-of attack. The chine is effective for improving directional stability. (5) The directional control effectiveness 'of the TCA rudder is the same as that of the Reference H rudder at low angles-of-attack, after taking factors, such as number of rudder panels deflected and vertical tail volume into account. However, rudder effectiveness was shown to be reduced at higher angles-of-attack. (6) The lateral stability was shown to be reduced relative to the Reference H, which may be beneficial at low speeds for alleviating lateral control saturation. (7) Lateral control effectiveness for the TCA was shown to be similar to the Reference H for negative trailing-edge flap deflections and was reduced by approximately 25% for positive trailing-edge flap deflections.

  15. Understanding barite and gypsum precipitation in upland acid-sulfate soils: An example from a Lufkin Series toposequence, south-central Texas, USA

    NASA Astrophysics Data System (ADS)

    Jennings, Debra S.; Driese, Steven G.

    2014-01-01

    Although low-temperature barite precipitation has been previously documented in soils and paleosols, pedogenic barite precipitation remains poorly understood. This study characterizes the micromorphology, elemental trends, and stable isotope geochemistry of sulfates in a barite-bearing soil (Lufkin Series) toposequence using optical microscopy, XRD, ICP-MS, and stable S and O isotope data. Synthesized data indicate that fluctuating redox processes and microbial activity resulting from epiaquatic and evaporative conditions lead to the precipitation of sulfates in the Lufkin soils. Stable sulfur and oxygen isotopes indicate that the primary source of sulfur is the partial dissolution of jarosite during microbial sulfate reduction. Barium-rich parent material provides adequate barium for barite precipitation. Barium is mobilized and concentrated in Btg horizons ~ 100-160 cm below the surface. The presence of humic acids in profiles lower on the landscape prevents barite precipitation and drives the precipitation of gypsum between saturated, anoxic conditions (November to May) and drier, more oxic conditions (May to November). Barite precipitation is a slow, punctuated process. Micromorphological data reveal that barite precipitates first along evacuated macropores and then in the adjacent matrix. In general, optimal conditions for pedogenic barite precipitation in upland wetland acid-sulfate soils are: 1) warm soil temperature that supports active sulfur-reducing and sulfur oxidizing microbes; 2) distinct wet/dry seasons that allow alternating redox conditions; 3) low-gradient landscape; 4) parent material that contains barium- and sulfur-rich constituents; and 5) a long-lived, stable landscape.

  16. Effect of precipitation, geographical location and biosynthesis on New Zealand milk powder bulk and fatty acids D/H ratios

    NASA Astrophysics Data System (ADS)

    Frew, R.; Emad Ehtesham, R.; Van Hale, R.; Hayman, A.; Baisden, T.

    2012-04-01

    D/H ratio measurements provide useful information for the investigation of biogeochemical influences on natural and agricultural produce, particularly with application to food traceability and authentication. Numerous studies have shown that variation of a product's D/H ratio is influenced by both environmental factors and biological processes. This study investigates the D/H ratio of New Zealand milk powder and individual fatty acids, and causal determinants of isotopic variation. One of the key environmental factors is precipitation, and the D/H ratio "isoscaping" of NZ has been undertaken. New Zealand provides a unique geography for these kinds of study in terms of proximity to the ocean and natural geographical variability from sea level to elevations as high as 3700 m. Milk powder samples were collected from different geographical regions from milk processing units, which were supplied by producers in the immediate region. H/D ratios of bulk milk powder and of individual fatty acids were determined. Initial comparison of the precipitation and milk powder bulk D/H data show a very good differentiation from north to southernmost parts of New Zealand and a relation between rain and milk bulk D/H abundance ratio. Almost 98% of milk FAs are in the form of triglycerides that have been extracted and hydrolysed to free FAs. Free FAs were esterified and analyzed with GC-IRMS. Individual FAs show variation in D/H ratio, and all values are depleted relative to the precipitation data. The difference in D/H ratio amongst individual FAs reflects the geographical environment and biological processes i.e. micro-organisms activity in the rumen of the cow. Short chain FAs (less than 8 carbons), particularly C4 (Butyric acid), appear to be key determinants. The variation in the data can be rationalized using statistical multivariate analysis.

  17. Evaluation results of xTCA equipment for HEP experiments at CERN

    NASA Astrophysics Data System (ADS)

    Di Cosmo, M.; Bobillier, V.; Haas, S.; Joos, M.; Mico, S.; Vasey, F.; Vichoudis, P.

    2013-12-01

    The MicroTCA and AdvancedTCA industry standards are candidate modular electronic platforms for the upgrade of the current generation of high energy physics experiments. The PH-ESE group at CERN launched in 2011 the xTCA evaluation project with the aim of performing technical evaluations and eventually providing support for commercially available components. Different devices from different vendors have been acquired, evaluated and interoperability tests have been performed. This paper presents the test procedures and facilities that have been developed and focuses on the evaluation results including electrical, thermal and interoperability aspects.

  18. The ecological effect of acid conditions and precipitation of hydrous metal oxides in a Rocky Mountain stream

    USGS Publications Warehouse

    McKnight, Diane M.; Feder, G.L.

    1984-01-01

    Periphyton and benthic invertebrates assemblages were studied at the confluence of two Rocky Mountain streams, Deer Creek and the Snake River near Montezuma, Colorado. Upstream from the confluence the Snake River is acidic and enriched in dissolved trace metals, while Deer Creek is a typical Rocky Mountain stream. In the Snake River, downstream from the confluence, the pH increases and hydrous metal oxides precipitate and cover the streambed. The algal and benthic invertebrate communities in the upstream reaches of the Snake River and in Deer Creek were very different. A liverwort, Scapania undulata var. undulata, was abundant in the Snake River, and although periphyton were very sparse, there were as many benthic invertebrates as in Deer Creek. Downstream from the confleunce, the precipitation of hydrous metal oxides greatly decreased the abundance of periphyton and benthic invertebrates. This study shows that in streams metal precipitates covering the streambed may have a more deleterious effect on stream communities than high metal-ion activities. ?? 1984 Dr. W. Junk Publishers.

  19. A Process-Based Model of TCA Cycle Functioning to Analyze Citrate Accumulation in Pre- and Post-Harvest Fruits

    PubMed Central

    Etienne, Audrey; Génard, Michel; Bugaud, Christophe

    2015-01-01

    Citrate is one of the most important organic acids in many fruits and its concentration plays a critical role in organoleptic properties. The regulation of citrate accumulation throughout fruit development, and the origins of the phenotypic variability of the citrate concentration within fruit species remain to be clarified. In the present study, we developed a process-based model of citrate accumulation based on a simplified representation of the TCA cycle to predict citrate concentration in fruit pulp during the pre- and post-harvest stages. Banana fruit was taken as a reference because it has the particularity of having post-harvest ripening, during which citrate concentration undergoes substantial changes. The model was calibrated and validated on the two stages, using data sets from three contrasting cultivars in terms of citrate accumulation, and incorporated different fruit load, potassium supply, and harvest dates. The model predicted the pre and post-harvest dynamics of citrate concentration with fairly good accuracy for the three cultivars. The model suggested major differences in TCA cycle functioning among cultivars during post-harvest ripening of banana, and pointed to a potential role for NAD-malic enzyme and mitochondrial malate carriers in the genotypic variability of citrate concentration. The sensitivity of citrate accumulation to growth parameters and temperature differed among cultivars during post-harvest ripening. Finally, the model can be used as a conceptual basis to study citrate accumulation in fleshy fruits and may be a powerful tool to improve our understanding of fruit acidity. PMID:26042830

  20. Acid precipitation and drinking water quality in the eastern United States. Final report, November 1981-January 1984

    SciTech Connect

    Taylor, F.; Taylor, J.A.; Symons, G.E.; Collins, J.J.; Schock, M.R.

    1984-01-01

    Research was conducted to provide accurate modern and historical data on drinking water quality and the possible effect of acid precipitation on water samples. Samples of source raw and finished water were collected from more than 300 surface and groundwater supplies in the New England States, New York, New Jersey, Pennsylvania, West Virginia, Virginia, and North Carolina. The samples were analyzed at EPA laboratories. Historical records were obtained dating back to 1886. Acid rain may dissolve harmful elements from soils and from water supply distribution systems. Because soils can alter the character of acid rain through buffering, causal relationships are difficult to identify. A helpful approach to this problem is the use of indices of water supply sensitiviy and corrosiveness. With these indices, drinking water standards, and reliable chemical data, an assessment of water supply characteristics has been accomplished. Though solution products of acid rain in the water supply sources studied do not exceed EPA Primary Drinking Water Regulations, a large number of tests for aluminum showed levels that could be of concern to kidney dialysis patients. Because of the present water quality conditions (low alkalinity and pH) at numerous water sources, future acid deposition could be expected to have a detrimental effect on water quality. 42 references, 15 figures, 42 tables.

  1. A mitochondrial GABA permease connects the GABA shunt and the TCA cycle, and is essential for normal carbon metabolism.

    PubMed

    Michaeli, Simon; Fait, Aaron; Lagor, Kelly; Nunes-Nesi, Adriano; Grillich, Nicole; Yellin, Ayelet; Bar, Dana; Khan, Munziba; Fernie, Alisdair R; Turano, Frank J; Fromm, Hillel

    2011-08-01

    In plants, γ-aminobutyric acid (GABA) accumulates in the cytosol in response to a variety of stresses. GABA is transported into mitochondria, where it is catabolized into TCA cycle or other intermediates. Although there is circumstantial evidence for mitochondrial GABA transporters in eukaryotes, none have yet been identified. Described here is an Arabidopsis protein similar in sequence and topology to unicellular GABA transporters. The expression of this protein complements a GABA-transport-deficient yeast mutant. Thus the protein was termed AtGABP to indicate GABA-permease activity. In vivo localization of GABP fused to GFP and immunobloting of subcellular fractions demonstrate its mitochondrial localization. Direct [(3) H]GABA uptake measurements into isolated mitochondria revealed impaired uptake into mitochondria of a gabp mutant compared with wild-type (WT) mitochondria, implicating AtGABP as a major mitochondrial GABA carrier. Measurements of CO(2) release, derived from radiolabeled substrates in whole seedlings and in isolated mitochondria, demonstrate impaired GABA-derived input into the TCA cycle, and a compensatory increase in TCA cycle activity in gabp mutants. Finally, growth abnormalities of gabp mutants under limited carbon availability on artificial media, and in soil under low light intensity, combined with their metabolite profiles, suggest an important role for AtGABP in primary carbon metabolism and plant growth. Thus, AtGABP-mediated transport of GABA from the cytosol into mitochondria is important to ensure proper GABA-mediated respiration and carbon metabolism. This function is particularly essential for plant growth under conditions of limited carbon.

  2. The Debate over Acid Precipitation--Opposing Views--Status of Research.

    DTIC Science & Technology

    1981-09-11

    effects of acid deposition on terrestrial ecosystems. This contrasts with the general agreement among scientists that oxides of sulfur and nitro - gen...Altsnuller and G.A. McBean, Co-chairman, Nov. 148U, p. 1I. 2/Peter E. Coffee , "Long-Range Transport of Acidic Pollutants to New York," in Proceedings of

  3. Molecularly imprinted polymer for chlorogenic acid by modified precipitation polymerization and its application to extraction of chlorogenic acid from Eucommia ulmodies leaves.

    PubMed

    Miura, Chitose; Li, Hui; Matsunaga, Hisami; Haginaka, Jun

    2015-10-10

    Molecularly imprinted polymers (MIPs) for chlorogenic acid (CGA) were prepared by modified precipitation polymerization using methacrylic acid as a functional monomer, divinylbenzene as a crosslinker and methanol or dimethylsulfoxide as a co-solvent. The prepared MIPs were microspheres with a narrow particle size distribution. Binding experiments and Scatchard analyses revealed that two classes of binding sites, high and low affinity sites, were formed on the MIP. The retention and molecular-recognition properties of the prepared MIP were evaluated using a mixture of water and acetonitrile as a mobile phase in hydrophilic interaction chromatography. With an increase of acetonitrile content, the retention factor of CGA was increased on the MIP. In addition to shape recognition, hydrophilic interactions seem to work for the recognition of CGA on the MIP. The MIP had a specific molecular-recognition ability for CGA, while other related compounds, such as caffeic acid, gallic acid, protocatechuic acid and vanillic acid, could not be recognized by the MIP. Furthermore, the MIP for CGA was successfully applied for extraction of CGA in the leaves of Eucommia ulmodies.

  4. Precipitation polymerization in acetic acid: study of the solvent effect on the morphology of poly(divinylbenzene).

    PubMed

    Yan, Qing; Zhao, Tongyang; Bai, Yaowen; Zhang, Fen; Yang, Wantai

    2009-03-12

    This paper reports on two important results regarding the precipitation polymerization of poly(divinylbenzene) (PDVB) in acetic acid (HAc). (1) Acetic acid is a novel kind of solvent worthy of investigation because it is amphipathic and innoxious. Thus, two kinds of model solvents, methyl ethyl ketone (MEK) and n-heptane, were selected to investigate the solvent effect on the particle morphology of PDVB-55 during precipitation polymerization in acetic acid. Monodisperse PDVB-55 microspheres were obtained with an MEK content of 30 vol % and a DVB loading of 2 vol %. Odd-shaped particles were found to almost disappear when MEK was added. For MEK contents up to 90 vol %, space-filling macrogels consisting of small particles with diameters of around 10 nm were obtained. More homocoagulated particles were produced when n-heptane was added, for which concentrations up to 50 vol % gave rise to cauliflower-like particles. Thus, in the acetic acid system, microspheres, pumpkin-like particles, macrogels, and coagulum could be successfully obtained. (2) The preparation of nonpolar PDVB-55 particles could be more predictable. For the first time-based on the regulation of former studies--the regularity of the dispersive term (delta(d)) on the particle morphology for a PDVB precipitation polymerization system was reported. The three-dimensional Hansen solubility parameters were utilized to perfect the regularity of the Hildebrand solubility parameter. Microspheres or particles were formed in the range of moderate delta values for both parameters, i.e., delta = 20.2-24.3 MPa1/2 or delta = 16 MPa1/2. What was even more important, delta(d) was found to be around 15.4 MPa1/2, and delta(h) should be below 13.5 MPa1/2. Cyclohexane, cyclohexanone, n-butyl acetate, and 1,4-dioxane were used to verify this regularity, and positive results were obtained. Stable, uniform, and well-separated PDVB-55 microspheres and particles were produced as a result of interaction forces between oligomers

  5. Soluble species in the Arctic summer troposphere - Acidic gases, aerosols, and precipitation

    NASA Technical Reports Server (NTRS)

    Talbot, R. W.; Vijgen, A. S.; Harriss, R. C.

    1992-01-01

    The large-scale spatial distribution from 0.15-to 6 km altitude in the North American Arctic troposphere of several soluble acidic gases and major aerosol species during the summertime is reported. The distribution is found to be compositionally consistent on a large spatial scale. The summertime troposphere is an acidic environment, with HCOOH and CH3COOH the principal acidic gases while acidic sulfate aerosols dominate the particulate phase. There appears to be a surface source of NH3 over the pack ice which may originate from decay of dead marine organisms on the ice surface, evolution from surface ocean waters in open ice leads, or release from rotting sea ice. At low altitude over the pack ice this NH34 appears to partially neutralize aerosol acidity. Over sub-Arctic tundra in southeastern Alaska, inputs of marine biogenic sulfur from the Bering Sea appear to be an important source of boundary layer aerosol SO4(2-). The rainwater acidity over the tundra is typical of remote regions.

  6. Soluble species in the Arctic summer troposphere - acidic gases, aerosols, and precipitation

    SciTech Connect

    Talbot, R.W.; Vijgen, A.S.; Harriss, R.C. Old Dominion Univ., Norfolk, VA )

    1992-10-01

    The large-scale spatial distribution from 0.15-to 6 km altitude in the North American Arctic troposphere of several soluble acidic gases and major aerosol species during the summertime is reported. The distribution is found to be compositionally consistent on a large spatial scale. The summertime troposphere is an acidic environment, with HCOOH and CH3COOH the principal acidic gases while acidic sulfate aerosols dominate the particulate phase. There appears to be a surface source of NH3 over the pack ice which may originate from decay of dead marine organisms on the ice surface, evolution from surface ocean waters in open ice leads, or release from rotting sea ice. At low altitude over the pack ice this NH34 appears to partially neutralize aerosol acidity. Over sub-Arctic tundra in southeastern Alaska, inputs of marine biogenic sulfur from the Bering Sea appear to be an important source of boundary layer aerosol SO4(2-). The rainwater acidity over the tundra is typical of remote regions. 61 refs.

  7. Generation of dose-response relationships to assess the effects of acidity in precipitation on growth and productivity of vegetation

    SciTech Connect

    Evans, L.S.

    1981-01-01

    Experiments were performed with several plant species in natural environments as well in a greenhouse and/or tissue culture facilities to establish dose-response functions of plant responses to simulated acidic rain in order to determine environmental risk assessments to ambient levels of acidic rain. Response functions of foliar injury, biomass of leaves and seed of soybean and pinto beans, root yields of radishes and garden beets, and reproduction of bracken fern are considered. The dose-response function of soybean seed yields with the hydrogen ion concentration of simulated acidic rainfalls was expressed by the equation y = 21.06-1.01 log x where y = seed yield in grams per plant and x = the hydrogen concentration if ..mu..eq l/sup -1/. The correlation coefficient of this relationship was -0.90. A similar dose-response function was generated for percent fertilization of ferns in a forest understory. When percent fertilization is plotted on logarithmic scale with hydrogen ion concentration of the simulated rain solution, the Y intercept is 51.18, slope -0.041 with a correlation coefficient of -0.98. Other dose-response functions were generated that assist in a general knowledge as to which plant species and which physiological processes are most impacted by acidic precipitation. Some responses did not produce convenient dose-response relationships. In such cases the responses may be altered by other environmental factors or there may be no differences among treatment means.

  8. Index markers of chronic fatigue syndrome with dysfunction of TCA and urea cycles

    PubMed Central

    Yamano, Emi; Sugimoto, Masahiro; Hirayama, Akiyoshi; Kume, Satoshi; Yamato, Masanori; Jin, Guanghua; Tajima, Seiki; Goda, Nobuhito; Iwai, Kazuhiro; Fukuda, Sanae; Yamaguti, Kouzi; Kuratsune, Hirohiko; Soga, Tomoyoshi; Watanabe, Yasuyoshi; Kataoka, Yosky

    2016-01-01

    Chronic fatigue syndrome (CFS) is a persistent and unexplained pathological state characterized by exertional and severely debilitating fatigue, with/without infectious or neuropsychiatric symptoms, lasting at least 6 consecutive months. Its pathogenesis remains incompletely understood. Here, we performed comprehensive metabolomic analyses of 133 plasma samples obtained from CFS patients and healthy controls to establish an objective diagnosis of CFS. CFS patients exhibited significant differences in intermediate metabolite concentrations in the tricarboxylic acid (TCA) and urea cycles. The combination of ornithine/citrulline and pyruvate/isocitrate ratios discriminated CFS patients from healthy controls, yielding area under the receiver operating characteristic curve values of 0.801 (95% confidential interval [CI]: 0.711–0.890, P < 0.0001) and 0.750 (95% CI: 0.584–0.916, P = 0.0069) for training (n = 93) and validation (n = 40) datasets, respectively. These findings provide compelling evidence that a clinical diagnostic tool could be developed for CFS based on the ratios of metabolites in plasma. PMID:27725700

  9. Synthesis of WO{sub 3} nanoparticles by citric acid-assisted precipitation and evaluation of their photocatalytic properties

    SciTech Connect

    Sánchez-Martínez, D.; Martínez-de la Cruz, A.; López-Cuéllar, E.

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ► WO{sub 3} nanoparticles were synthesized by a simple citric acid-assisted precipitation. ► WO{sub 3} photocatalyst was able to the partial mineralization of rhB, IC and MO. ► WO{sub 3} can be considered as a photocatalyst active under visible light irradiation. -- Abstract: WO{sub 3} nanoparticles were synthesized by citric acid-assisted precipitation method using a 1:1.5 molar ratio of ammonium paratungstate hydrate (H{sub 42}N{sub 10}O{sub 42}W{sub 12}·xH{sub 2}O):citric acid (C{sub 6}H{sub 8}O{sub 7}). The formation of monoclinic crystal structure of WO{sub 3} at different temperatures was confirmed by X-ray powder diffraction (XRD). The characterization of the samples synthesized was complemented by transmission electron microscopy (TEM), Brunauer–Emmitt–Teller surface area (BET) and diffuse reflectance spectroscopy (DRS). According to the thermal treatment followed during the synthesis of WO{sub 3}, the morphology of the nanoparticles formed was characterized by rectangular and ovoid shapes. The photocatalytic activity of WO{sub 3} obtained under different experimental conditions was evaluated in the degradation of rhodamine B (rhB), indigo carmine (IC), methyl orange (MO), and Congo red (CR) in aqueous solution under UV and UV–vis radiation. The highest photocatalytic activity was observed in the sample obtained by thermal treatment at 700 °C. In general, the sequence of degradation of the organic dyes was: indigo carmine (IC) > rhodamine B (rhB) > methyl orange (MO) > Congo red (CR). The mineralization degree of organic dyes by WO{sub 3} photocatalysts was determined by total organic carbon analysis (TOC) reaching percentages of mineralization of 82% (rhB), 85% (IC), 28% (MO), and 7% (CR) for 96 h of lamp irradiation.

  10. Relationship between acidity and ionic composition of wet precipitation: A two years study at an urban site, Thessaloniki, Greece

    NASA Astrophysics Data System (ADS)

    Anatolaki, Ch.; Tsitouridou, R.

    2009-03-01

    Wet precipitation samples were collected in the city center of Thessaloniki, northern Greece, for two years with different rainfall amount (April 2002-March 2004). All samples were analyzed for major anions and cations (Cl -, NO 3-, SO 42-, NH 4+, Na +, K +, Ca 2+ and Mg 2+). HCO 3- concentrations were calculated through pH measurements. Arithmetic mean pH values of 6.06 and 6.57 were found for the two periods. 10.5% of the first year rain events (April 2002-March 2003) and 2.5% of the second (April 2003-March 2004) exhibited pH ≤ 4.5. The quite typical, for Mediterranean areas, trend Ca 2+ > SO 42- > NH 4+ > Cl - > NO 3- was observed in the majority of the samples. The study of the relationship between the ionic concentrations and the precipitation amount gave information about the scavenging mechanism of ions (below or in-cloud). 67% of the rain acidity was found to be due to sulfuric acid and the rest 33% to nitric acid. The calculation of Neutralization Factors (NF) and the application of Multiple Linear Regression Analysis (MLR), showed the higher Ca 2+ contribution to the neutralization process. The impact of maritime sources was extracted from the SSF of Cl - and Mg 2+, while the anthropogenic origin of SO 42- was supported by the high NSSF (~ 98%). The local calcareous soil dust and possible long-range transport are the main sources of Ca 2+ in the area. A case study by using trajectory analysis to predict a long-range transport of pollutants from Etnean volcano, Italy, to the study area, is described.

  11. The Variations of Glycolysis and TCA Cycle Intermediate Levels Grown in Iron and Copper Mediums of Trichoderma harzianum.

    PubMed

    Tavsan, Zehra; Ayar Kayali, Hulya

    2015-05-01

    The efficiency of optimal metabolic function by microorganism depends on various parameters, especially essential metal supplementation. In the present study, the effects of iron and copper metals on metabolism were investigated by determination of glycolysis and tricarboxylic acid (TCA) cycle metabolites' levels with respect to the metal concentrations and incubation period in Trichoderma harzianum. The pyruvate and citrate levels of T. harzianum increased up to 15 mg/L of copper via redirection of carbon flux though glycolysis by suppression of pentose phosphate pathway (PPP). However, the α-ketoglutarate levels decreased at concentration higher than 5 mg/L of copper to overcome damage of oxidative stress. The fumarate levels correlated with the α-ketoglutarate levels because of substrate limitation. Besides, in T. harzianum cells grown in various concentrations of iron-containing medium, the intracellular pyruvate, citrate, and α-ketoglutarate levels showed positive correlation with iron concentration due to modifying of expression of glycolysis and TCA cycle enzymes via a mechanism involving cofactor or allosteric regulation. However, as a result of consuming of prior substrates required for fumarate production, its levels rose up to 10 mg/L.

  12. Effects of calcium phosphate precipitation method on acid resistance to apatite powder and bovine tooth.

    PubMed

    Suge, Toshiyuki; Kawasaki, Akiko; Ishikawa, Kunio; Matsuo, Takashi; Ebisu, Shigeyuki

    2008-07-01

    The aims of this study were to evaluate the effects of CPP method on the crystallinity of apatite powder and on the acid resistance of bovine enamel. Crystallinity degrees of apatite powder before and after CPP treatment were measured by powder X-ray diffraction analysis. Polished bovine enamel specimens treated with CPP method or NaF were immersed in a lactic acid solution for up to five days. The demineralized depth of enamel was measured with a surface roughness analyzer. XRD peaks became sharper after the CPP treatment, indicating an increased crystallinity of the apatite powder. The demineralized depth of bovine enamel treated with CPP method was shallower than that of enamel treated with NaF. Results of this study revealed that the CPP method increased the crystallinity of apatite powder and the acid resistance of enamel. Therefore, the CPP method would be useful not only for treating dentin hypersensitivity, but also for the prevention of dental caries.

  13. Acid precipitation effects on algal productivity and biomass in Adirondack Lakes. Final completion report

    SciTech Connect

    Hendrey, G.R.

    1982-12-01

    Relationships between phytoplankton communities and lake acidity in three Adirondack Mountain Lakes were studied at Woods Lake, Sagamore Lake (pH ca. 5.5), and Panther Lake (pH ca. 7.0). Numbers of phytoplankton species observed were Woods 45, Sagamore 55, and Panther 85, conforming to observations at many other sites that species numbers decrease with increasing acidity. The smaller plankton are relatively more important in the more acid lakes, Woods > Sagamore > Panther. This pattern could be determined by nutrient availability (lake acidification is suspected of leading to decreased availability of phosphorus). The amount of 14C-labelled dissolved photosynthate (14C-DOM), as a percent of total productivity, is ordered Woods > Sagamore > Panther.

  14. Soluble species in the Arctic summer troposphere: Acidic gases, aerosols, and precipitation

    NASA Astrophysics Data System (ADS)

    Talbot, R. W.; Vijgen, A. S.; Harriss, R. C.

    1992-10-01

    We report here the distribution of selected acidic gases and aerosol species in the North American Arctic and sub-Arctic summer troposphere. The summertime troposphere is an acidic environment, with HCOOH and CH3COOH the principal acidic gases and acidic sulfate aerosols dominating the particulate phase. Our data show that the acidic gas and aerosol composition is uniform on a large spatial scale. There appears to be a surface source of NH4+ over the Arctic Ocean pack ice which may reflect release of NH3 from decay of dead marine organisms on the ice surface near ice leads, release from rotting sea ice, or an upward flux from surface ocean waters in open ice leads. This NH3 appears to partially neutralize aerosol acidity in the boundary layer. Over sub-Arctic tundra in southwestern Alaska inputs of marine biogenic sulfur from the nearby Bering Sea appear to be an important source of boundary layer aerosol SO42-. While there were only minor effects on aerosol chemistry over the tundra from sea salt, the rainwater chemistry showed influence from marine aerosols which were apparently incorporated into air masses during frontal passages moving inland from the Bering Sea. The rainwater acidity over the tundra (pH 4.69) is typical of remote regions. The principal acidity components are H2SO4 and carboxylic acids, especially HCOOH. The carboxylic acids appear to have a strong continental biogenic source, but hydrocarbons of marine origin and emissions from forest fires may also be important. The wet deposition fluxes of NO3--N and SO42--S over sub-Arctic tundra during July-August 1988 were 2.1 and 2.4 mmol m-2 yr-1. Wet deposition of NO3- was nearly 3 times higher than the average NOy deposition flux, which is believed to represent primarily dry deposition of HNO3 (Bakwin et al., this issue). Our measurements indicate that the mid-troposphere in the Arctic is generally contaminated with low levels of anthropogenic pollutants even in summer when direct atmospheric coupling

  15. A global assessment of precipitation chemistry and deposition of sulfur, nitrogen, sea salt, base cations, organic acids, acidity and pH, and phosphorus

    NASA Astrophysics Data System (ADS)

    Vet, Robert; Artz, Richard S.; Carou, Silvina

    2014-08-01

    Investigating and assessing the chemical composition of precipitation and atmospheric deposition is essential to understanding how atmospheric pollutants contribute to contemporary environmental concerns including ecosystem acidification and eutrophication, loss of biodiversity, air pollution and global climate change. Evidence of the link between atmospheric deposition and these environmental issues is well established. The state of scientific understanding of this link is that present levels of atmospheric deposition of sulfur and nitrogen adversely affect terrestrial and aquatic ecosystems, putting forest sustainability and aquatic biodiversity at risk. Nitrogen and phosphorus loadings are linked to impacts on the diversity of terrestrial and aquatic vegetation through biological cycling, and atmospheric deposition plays a major role in the emission-transport-conversion-loss cycle of chemicals in the atmosphere as well as the formation of particulate matter and ozone in the troposphere. Evidence also shows that atmospheric constituents are changing the earth's climate through direct and indirect atmospheric processes. This Special Issue, comprising a single article titled "A global assessment of precipitation chemistry and deposition of sulfur, nitrogen, sea salt, base cations, organic acids, acidity and pH, and phosphorus", presents a recent comprehensive review of precipitation chemistry and atmospheric deposition at global and regional scales. The information in the Special Issue, including all supporting data sets and maps, is anticipated to be of great value not only to the atmospheric deposition community but also to other science communities including those that study ecosystem impacts, human health effects, nutrient processing, climate change, global and hemispheric modeling and biogeochemical cycling. Understanding and quantifying pollutant loss from the atmosphere is, and will remain, an important component of each of these scientific fields as they

  16. Metal and acidity fluxes controlled by precipitation/dissolution cycles of sulfate salts in an anthropogenic mine aquifer

    NASA Astrophysics Data System (ADS)

    Cánovas, C. R.; Macías, F.; Pérez-López, R.

    2016-05-01

    Underground mine drainages are extremely difficult to study due to the lack of information about the flow path and source proximity in relation to the outflow adit. Geochemical processes controlling metals and acidity fluxes in a complex anthropogenic mine aquifer in SW Spain during the dry and rainy season were investigated by geochemical and statistical tools. High concentrations of acidity, sulfate, metals and metalloids (e.g. Fe, Cu, Zn, As, Cd, Ni, Co) were observed due to intense sulfide oxidation processes. The high residence time inside the anthropogenic aquifer, around 40 days, caused the release of significant quantities of metals linked to host rocks (e.g. Al, Ca, Ge, Li, Mg, REE). The most outstanding characteristic of the acid mine drainage (AMD) outflows is the existence of higher Fe/SO4 molar ratios than those theoretical of pyrite (0.50) during most of the monitored period, due to a fire which occurred in 1949 and remained active for decades. Permanent and temporal retention mechanisms of acidity and metals were observed in the galleries. Once released from sulfide oxidation, Pb and As are sorbed on Fe oxyhydroxysulfate or precipitated as low solubility minerals (i.e. anglesite) inside the galleries. The precipitation of evaporitic sulfate salts during the dry season and the subsequent re-dissolution after rainfall control the fluxes of acidity and main metals (i.e. Fe, Mg, Al) from this anthropogenic aquifer. Some elements, such as Cd, Cu, Ni, REE and Zn, are retained in highly soluble sulfate salts while other elements, such as Ge, Pb and Sc, have a lower response to washout processes due to its incorporation in less soluble sulfate salts. In this way, metal concentration during the washout processes would be controlled by the proportion and solubility of each type of evaporitic sulfate salt stored during the dry season. The recovery of metals of economic interest contained in the AMD could help to self-finance the remediation of these waters in

  17. Acid precipitation effects on algal productivity and biomass in Adirondack Mountain lakes

    SciTech Connect

    Hendrey, G.R.

    1982-12-01

    Relationships between phytoplankton communities and lake acidity in three Adirondack Mountain lakes were studied at Woods Lake (pH ca. 4.9), Sagamore Lake (pH ca. 5.5), and Panther Lake (pH ca. 7.0). Species numbers decrease with increasing acidity. Patterns of increasing biomass and productivity in Woods Lake may be atypical of similar oligotrophic lakes in that they develop rather slowly to maxima six weeks after ice-out, instead of occurring very close to ice-out. Contributions of netplankton, nannoplankton and ultraplankton to productivity per m/sup 2/ show that the smaller plankton are relatively more important in the more acid lakes. This pattern could be determined by nutrient availability (lake acidification is suspected of leading to decreased availability of phosphorus). This was consistent with a hypothesis that microbial heterotrophic activity is reduced with increasing acidity, but the smaller phytoplankton may be more leaky at low pH. 11 references, 2 tables.

  18. Potential for acid precipitation damage to lakes of the Sierra Nevada, California

    SciTech Connect

    Harte, J.; Holdren, J.; Tonnesson, K.

    1983-04-01

    One of the areas of California potentially sensitive to acidic deposition is the Sierra Nevada, located along the eastern boundary. A report on sensitive areas in North America identifies the Sierra as a region characterized by poorly buffered soils and granite based lakes. The subalpine and alpine lakes in this region share many of the characteristics of lakes adversely affected by acid deposition in other parts of the US and the world. For this investigation selected subalpine lakes of the western slope of the Sierra were chosen for study, to establish baseline water quality which would allow for the identification of chemical and biological changes due to acidic deposition. It was then attempted to simulate the ecosystem stress of increased acidic deposition, particularly in the form of snowmelt, on these systems by performing microcosm experiments in the laboratory. These experiments were particularly concerned with recording changes in concentrations of micronutrients which might be leached from lake sediments with increasing acidification. This phenomenon is particularly important to study in the light of finds on the importance of aluminum leaching in the northeast which was led to toxic effects of biota in Adirondack lakes. 10 references, 3 figures, 1 table.

  19. Aquatic Activities for Middle School Children. A Focus on the Effects of Acid Precipitation.

    ERIC Educational Resources Information Center

    Minnesota Univ., Minneapolis. Minnesota Sea Grant Program.

    Basic water-related concepts and underlying principles of acid rain are described in this curriculum in a manner that young children can understand. The curriculum consists of activities presented in four units: Background Unit, Earth Science Unit, Life Science Unit, and Extension Unit. The first three units consist of several modules, each module…

  20. Acetylation dictates the morphology of nanophase biosilica precipitated by a 14-amino acid leucine-lysine peptide.

    PubMed

    Lutz, Helmut; Jaeger, Vance; Bonn, Mischa; Pfaendtner, Jim; Weidner, Tobias

    2017-02-01

    N-terminal acetylation is a commonly used modification technique for synthetic peptides, mostly applied for reasons of enhanced stability, and in many cases regarded as inconsequential. In engineered biosilification - the controlled deposition of silica for nanotechnology applications by designed peptides - charged groups often play a deciding role. Here we report that changing the charge by acetylation of a 14-amino acid leucine-lysine (LK) peptide dramatically changes the morphology of precipitated biosilica; acetylated LK peptides produce nano-spheres, whereas nano-wires are precipitated by the same peptide in a non-acetylated form. By using interface-specific vibrational spectroscopy and coarse-grained molecular simulations, we show that this change in morphology is not the result of modified peptide-silica interactions, but rather caused by the stabilization of the hydrophobic core of peptide aggregates created by the removal of a peptide charge upon acetylation. These results should raise awareness of the potential impact of N-terminal modifications in peptide applications. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  1. Production and characterization of poly(3-hydroxybutyrate) generated by Alcaligenes latus using lactose and whey after acid protein precipitation process.

    PubMed

    Berwig, Karina Hammel; Baldasso, Camila; Dettmer, Aline

    2016-10-01

    Whey after acid protein precipitation was used as substrate for PHB production in orbital shaker using Alcaligenes latus. Statistical analysis determined the most appropriate hydroxide for pH neutralization of whey after protein precipitation among NH4OH, KOH and NaOH 10%w/v. The results were compared to those of commercial lactose. A scale-up test in a 4L bioreactor was done at 35°C, 750rpm, 7L/min air flow, and 6.5 pH. The PHB was characterized through Fourier Transform Infrared Spectroscopy, thermogravimetry and differential scanning calorimetry. NH4OH provided the best results for productivity (p), 0.11g/L.h, and for polymer yield, (YP/S), 1.08g/g. The bioreactor experiment resulted in lower p and YP/S. PHB showed maximum degradation temperature (291°C), melting temperature (169°C), and chemical properties similar to those of standard PHB. The use of whey as a substrate for PHB production did not affect significantly the final product quality.

  2. Stability-time profile of trichloroacetic acid at various concentrations and storage conditions.

    PubMed

    Spinowitz, A L; Rumsfield, J

    1989-09-01

    Trichloroacetic acid (TCA) is a deliquescent chemical widely used for a variety of procedures. Stability of various concentrations of TCA in both amber glass and plastic bottles stored under refrigeration and at room temperature was measured at several time points. Extended stability data suggest that TCA potency is stable for 23 weeks and would best be maintained in glass amber bottles stored under refrigeration.

  3. Ammonia emission factors for the NAPAP (National Acid Precipitation Assessment Program) emission inventory. Final report, January 1985-December 1986

    SciTech Connect

    Misenheimer, D.C.; Warn, T.E.; Zelmanowitz, S.

    1987-01-01

    The report provides information on certain sources of ammonia emissions to the atmosphere for use in the National Acid Precipitation Assessment Program (NAPAP) emission inventories. Major anthropogenic sources of ammonia emissions to the atmosphere are identified, and emission factors for these sources are presented based on a review of the most recent data available. The emission factors developed are used to estimate nationwide emissions for base year 1980 and are compared to ammonia emission factors used in other emission inventories. Major anthropogenic source categories covered are cropland spreading of livestock wastes, beef cattle feedlots, fertilizer manufacture and use, fuel combustion, ammonia synthesis, petroleum refineries, and coke manufacture. Approximately 840,000 tons of ammonia is estimated to have been emitted in the U.S. in 1980; over 64% of which is estimated to have been from livestock wastes.

  4. A computer simulation of ecosystem processes in forests for application to air pollution, acid precipitation and global change

    SciTech Connect

    Kercher, J.R. ); Anderson, P.D. . Dept. of Forestry and Resource Management)

    1992-07-17

    We have developed a simulation model, TREE, of the effects of gaseous air pollutants and acid precipitation on the forest ecosystem processes of tree productivity and growth. This model is based on an existing general model of forest ecosystem processes developed for regional application (FOREST-BGC) combined with an existing model of plant productivity and transpiration (BACROS). The former model uses daily and annual time-steps; BACROS uses hourly time-steps and computes gaseous pollutant (ozone) uptake. In FOREST-BGC, we model the effects of ozone by reducing productivity based on the cumulative uptake for each leaf age-class. The model computations convert this reduction in productivity to a reduction in growth. This version of the model restricts consideration of acid precipitation to possible effects on productivity due to foliar exposure. Basic model performance has been studied for ponderosa pine exposed to ozone at the USFS Chico Tree Improvement Center The model simulates observed phenomena such as draw down of soil water during summer months. For ozone levels for the Chico Field Site for the 1990 season, maximum daily ozone uptake occurred in August with peak of 2.2 {times} 10{sup {minus}5} kg m{sup {minus}2} d{sup 1}. Cumulative annual ozone uptake for current year needles was 3.2 {times} 10{sup {minus}2} kg m{sup {minus}2} producing a 12.6% reduction in productivity for current year needles and a 13.3% reduction in chlorophyll and effective leaf area. Total transpiration was 0.95 m. The model is now being used to develop a terrestrial ecosystem submodel for a global scale Earth System Model (ESM) that integrates interacting atmospheric, oceanic, and land system components. Algorithms from the forest model will support feedback calculation of the effect of forests on atmospheric physics and chemistry as well as calculate effects of climate- and C0{sub 2}-change on forest productivity.

  5. Validation of a NIR quantification method for the determination of chlorogenic acid in Lonicera japonica solution in ethanol precipitation process.

    PubMed

    Wu, Zhisheng; Xu, Bing; Du, Min; Sui, Chenglin; Shi, Xinyuan; Qiao, Yanjiang

    2012-03-25

    The feasibility of near-infrared spectroscopy (NIRS) for chlorogenic acid content analysis in ethanol precipitation process of water extract of Lonicera japonica was verified in this work. A calibration and validation set was designed for the conception and evaluation of the method adequacy. An experimental protocol was then followed, involving two different NIR instruments for data acquisition. On the basis of this protocol, the model was developed based on partial least squares regression (PLS) and the determination coefficient (R(2)(cal) and R(2)(val)), standard error of calibration and prediction (SEC and SEP) were 0.9962, 0.9955, 111.1 μg/mL and 107.1 μg/mL for Holographic Grating NIR instrument, and 0.9984, 0.9971, 53.6 μg/mL and 83.3 μg/mL for Fourier Transform NIR instrument. However, such above criteria did not clearly demonstrate the model's prediction error over each analyzed content range. Consequently, a novel approach based on accuracy profile which allowed the acquisition of the lower limit of quantification (LLOQ) was used to validate the robustness and accuracy of PLS model. The resulting accuracy profile showed that PLS model was able to determine chlorogenic acid content by two NIR systems, whose LLOQ was about 1550 μg/mL. It was concluded that the two NIR systems were suitable for use as Process Analytical Technology (PAT) to understand ethanol precipitation process of water extract of Lonicera japonica.

  6. Red spruce germination and growth in soil-mediated regeneration microcosms under acid precipitation

    SciTech Connect

    Ho, M.

    1992-01-01

    In the past three decades, atmospheric pollution has caused substantial problems for the environment as well as for many biological processes. The objective of this study focuses on red spruce (Picea ruben Sarg.) regeneration potential and chemical change within the soil-water-plant continuum following simulated acid rain treatments. Inceptisols from three forests at 1735, 1920, and 2015 m at Mt. Mitchell, North Carolina had lower pH, bulk density, and higher organic matter, and base cations as altitude increased. Red spruce seeds were collected from two nearby standing trees at the 1735 m site. A strip-split-split plot experiment was constructed using soils from the two lower elevations, which support natural red spruce stands. Besides a control (pH 5.6, NO[sub 3]:SO[sub 4] ratio 0.10), eight treatments corresponding to two pHs (3.5 and 4.2) with four NO[sub 3]:SO[sub 4] ratios (0.20, 0.33, 0.40, and 0.67) each were used. Seedling emergence and growth, chemistry of soil. Soil leachate, and plant tissue were analyzed to test soil differences and treatment effects of acidity, nitrate, and sulfate. Temporal patterns of germination respond more to soil than to rain chemistry, but significant interactions were found. Besides higher survival, faster germinating seedlings in the 1735 m soil also produced more complex root system and more biomass. Lower root-to-shoot ratios at more acidic treatments suggest a negative effect of acidity on root growth. Canonical discriminant analysis revealed that factors controlling overall soil chemistry were dominated by soil origin, then by rain pH.

  7. National Acid Precipitation Assessment Program Report to Congress: An Integrated Assessment

    DTIC Science & Technology

    2005-01-01

    qualitative indicators to assess the effectiveness of the cap and trade approach to reduce emissions, improve air quality and reduce acid deposition while...report indicates that nitrogen deposition has declined in some areas with resulting benefits. Overall a 40% reduction in NOx emissions from power...acidification.The report, however, also indicates that emission reductions beyond Title IV alone are not sufficient to allow sensitive forests and aquatic systems

  8. Expression patterns of proliferating cell nuclear antigen in trichloroacetic acid peeled skin.

    PubMed

    Yamamoto, Yuki; Uede, Koji; Yonei, Nozomi; Furukawa, Fukumi

    2007-02-01

    This study was designed to investigate whether trichloroacetic acid (TCA) peeling induces cellular proliferation in human skin using an immunohistochemical method. A 40% TCA peel resulted in a greater number of proliferating cell nuclear antigen (PCNA)-immunopositive cells in the whole epidermis as compared with 60% TCA or phenol peels. This finding suggests that long-term and frequent TCA peelings of low concentration would require special attention for unexpected cutaneous lesions such as skin tumors.

  9. Acidity, nutrients, and minerals in atmospheric precipitation over Florida: deposition patterns, mechanisms and ecological effects

    SciTech Connect

    Brezonik, P.L.; Hendry, C.D. Jr.; Edgerton, E.S.; Schulze, R.L.; Crisman, T.L.

    1983-06-01

    A monitoring network of 21 bulk and 4 wet/dry collectors located throughout Florida measured spatial and temporal trends during a one-year period from May 1978 to April 1979. The project summary notes that statewide deposition rates of nitrogen and phosphorus were below the loading rates associated with eutrophication, although nutrient concentrations were higher during the summer. Overall, pH appears to have relatively small effects (in the range 4.7-6.8) on community structure in soft-water Florida lakes. More dramatic effects could occur under more acidic conditions in the future. 4 references, 5 figures, 1 table.

  10. The Tribolium castaneum cell line TcA: a new tool kit for cell biology.

    PubMed

    Silver, Kristopher; Jiang, Hongbo; Fu, Jinping; Phillips, Thomas W; Beeman, Richard W; Park, Yoonseong

    2014-10-30

    The red flour beetle, Tribolium castaneum, is an agriculturally important insect pest that has been widely used as a model organism. Recently, an adherent cell line (BCIRL-TcA-CLG1 or TcA) was developed from late pupae of the red flour beetle. Next generation transcriptome sequencing of TcA cells demonstrated expression of a wide variety of genes associated with specialized functions in chitin metabolism, immune responses and cellular and systemic RNAi pathways. Accordingly, we evaluated the sensitivity of TcA cells to dsRNA to initiate an RNAi response. TcA cells were highly sensitive to minute amounts of dsRNA, with a minimum effective dose of 100 pg/mL resulting in significant suppression of gene expression. We have also developed a plasmid containing two TcA-specific promoters, the promoter from the 40S ribosomal protein subunit (TC006550) and a bi-directional heat shock promoter (TcHS70) from the intergenic space between heat shock proteins 68a and b. These promoters have been employed to provide high levels of either constitutive (TC006550) or inducible (TcHS70) gene expression of the reporter proteins. Our results show that the TcA cell line, with its sensitivity to RNAi and functional TcA-specific promoters, is an invaluable resource for studying basic molecular and physiological questions.

  11. Nickel recovery from spent Raneynickel catalyst through dilute sulfuric acid leaching and soda ash precipitation.

    PubMed

    Lee, Jin Young; Rao, S Venkateswara; Kumar, B Nagaphani; Kang, Dong Jun; Reddy, B Ramachandra

    2010-04-15

    Pharmaceutical industry makes extensive use of Raneynickel catalyst for various organic drug intermediates/end products. Spent catalysts contain environmentally critical and economically valuable metals. In the present study, a simple hydrometallurgical process using dilute sulfuric acid leaching was described for the recovery of nickel from spent Raneynickel catalyst. Recovery of nickel varied with acid concentration and time, whereas temperature had negligible effect. Increase of S/L ratio to 30% (w/v) showed marginal effect on nickel (90%) recovery, whereas Al recovery decreased drastically to approximately 20%. Under the optimum conditions of leaching viz: 12 vol.% H(2)SO(4), 30 degrees C, 20% solid to liquid (S/L) ratio and 120 min reaction time, it was possible to recover 98.6% Ni along with 39.2% Al. Leach liquor [pH 0.7] containing 85.0 g/L Ni and 3.25 g/L Al was adjusted to pH 5.4 with 30 wt.% alkali for quantitative aluminum removal. Nickel loss was about 2% during this Al removal step. Nickel from the purified leach liquor was recovered as nickel carbonate by adding required amount of Na(2)CO(3). The purity of NiCO(3) product was found to be 100% with a Ni content of 48.6%. Na(2)SO(4) was recovered as a by-product with a purity of 99%. Complete process is presented.

  12. Evaluation of phosphate pebble as a precipitant for acid mine drainage treatment

    SciTech Connect

    Choi, J.C.; West, T.R.

    1995-12-01

    Laboratory testing was performed to evaluate the effectiveness of phosphate pebbles from Florida in the treatment of acid mine drainage under aerobic conditions. Using different flow rates, results show that phosphate pebbles effectively removed ferric iron up to 1,200 mg/l, aluminum up to 800 mg/l and sulfate up to 8,600 mg/l in three weeks. In addition, the pH increased to values as high as 3.2 in the effluent water from a pH of the influent water ranging from 2.1 to 2.2. Removal of ferric iron, aluminum, and sulfate as well as pH increases were inversely proportional to flow rates, ranging from 1.17 {times} 10{sup {minus}4} to 1.05 {times} 10{sup {minus}3} liters per minute per kg of phosphate pebble. Apparently this method can be applied to reduce acid mine drainage from old coal refuse piles, even those containing high concentration of ferric iron and aluminum ions.

  13. Effect of acidic precipitation on amphibian breeding in temporary ponds in Pennsylvania. [Rana sylvatica; Ambystoma jeffersonianum

    SciTech Connect

    Freda, J.; Dunson, W.A.

    1985-11-01

    This study assessed the impacts of acid deposition on amphibians breeding in temporary ponds in Pennsylvania by investigating the lowest pH's at which embryos could hatch, the physiological effects of low pH on amphibian larvae, pond chemistry and the influence of rainfall on pond pH, and the effect of pond pH on embryonic survival and local distribution of Ambystoma jeffersonianum and Rana sylvatica. At very low pH's, embryos stopped development soon after exposure. At higher but still lethal pH's, embryos became curled and failed to hatch. Embryos of Ambystoma were able to hatch even though they were curled, but R. sylvatica became trapped and died. Acute exposure to low pH's depressed sodium influx and accelerated sodium efflux, with a net loss of 50% of body sodium resulting in death. Increasing the external calcium concentration extended survival time by slowing the loss of sodium. Chronic exposure to low pH's resulted in reduction in body sodium, but to a lesser degree. R sylvatica tadpoles from a low pH pond had lower body sodium than tadpoles from a nearby high pH pond. Tadpoles from both ponds placed in a low pH pond underwent higher sodium efflux than when placed in the high pH pond. In studying the effect of low environmental pH, A. jeffersonianum was intolerant of low pH and was absent from most acidic ponds. R. sylvatica was tolerant and was found in ponds with the lowest pH. 73 refs., 14 figs., 21 tabs.

  14. Jarosite Precipitation from Acidic Saline Waters in Kachchh, Gujarat, India: an Appropriate Martian Analogue?

    NASA Astrophysics Data System (ADS)

    Mitra, S.; Gupta, S.; Bhattacharya, S.; Banerjee, S.; Chauhan, P.; Parthasarathy, G.

    2014-12-01

    The origin of jarosite [KFe3(SO4)2(OH)6] on the Martian surface has been an intriguing problem since the Mars Exploration Rover 'Opportunity' first revealed its presence at the Meridiani Planum on Mars. To explain its origin, several terrestrial analogue sites have been studied in different geographical zones. Although several models have been suggested, there is a consensus that only the prevalence of acidic and oxidizing aqueous environmental conditions are conducive to form jarosite. In the Kachchh region of Gujarat, western India, jarosite has been recently discovered from gorges dissecting the Paleocene Matanumadh Formation sediments, that overlie basalts of the Deccan Volcanic Province. This formation comprises pebble conglomerates, carbonaceous shales and purple sandstones capped by a laterite on top. Jarosite, in association with gypsum and goethite, has been detected through FTIR and VNIR spectrometry in almost all litho-units of the succession, albeit in different modes and concentrations. The occurrence of jarosite within black shale in other parts of the world, has been attributed to the oxidation of pyrites within the shale layers. However, in shales of the Matanumadh Formation, jarosite is restricted to fractures that cut across the bedding, while the overlying purple sandstone unit only preserves jarosite in shale clasts within the sandstone. Since the sandstone overlies the black shale layer, downward percolation of sulfate-bearing water from the oxidation of pyrite within the shale layer cannot explain jarosite formation in this unit. In addition, no jarosite is observed below or within pyrite-rich lignite bearing sections in other parts of Kachchh. Alternative suggestions, that jarosite developed in the immediate aftermath of Deccan volcanism as surface waters were rendered acidic by interaction with the final phase of volcanic effusives, are also unlikely as on-going studies suggest that jarosite is not restricted to the Matanumadh Formation. The

  15. Limestone characterization to model damage from acidic precipitation: Effect of pore structure on mass transfer

    USGS Publications Warehouse

    Leith, S.D.; Reddy, M.M.; Irez, W.F.; Heymans, M.J.

    1996-01-01

    The pore structure of Salem limestone is investigated, and conclusions regarding the effect of the pore geometry on modeling moisture and contaminant transport are discussed based on thin section petrography, scanning electron microscopy, mercury intrusion porosimetry, and nitrogen adsorption analyses. These investigations are compared to and shown to compliment permeability and capillary pressure measurements for this common building stone. Salem limestone exhibits a bimodal pore size distribution in which the larger pores provide routes for convective mass transfer of contaminants into the material and the smaller pores lead to high surface area adsorption and reaction sites. Relative permeability and capillary pressure measurements of the air/water system indicate that Salem limestone exhibits high capillarity end low effective permeability to water. Based on stone characterization, aqueous diffusion and convection are believed to be the primary transport mechanisms for pollutants in this stone. The extent of contaminant accumulation in the stone depends on the mechanism of partitioning between the aqueous and solid phases. The described characterization techniques and modeling approach can be applied to many systems of interest such as acidic damage to limestone, mass transfer of contaminants in concrete and other porous building materials, and modeling pollutant transport in subsurface moisture zones.

  16. Chemical composition of softwater Florida lakes and their sensitivity to acid precipitation

    SciTech Connect

    Hendry, C.D.; Brezonik, P.L.

    1984-02-01

    Based on alkalinity data for 596 lakes, 31 percent of Florida's 7300 lakes have < 100 ..mu..eq/L alkalinity and are sensitive to acid deposition. More than two-thirds of the lakes in 12 northern Florida counties fit this criterion. Increasing aluminum and decreasing nutrient and chlorophyll a concentrations were observed with decreasing pH in a survey of 20 softwater lakes. Maximum measured aluminum values (100-150 ..mu..g/L) are below levels associated with fish toxicity. Factor analysis showed that lake chemistry was related to three principal factors, representing three major processes: watershed weathering, acidification, and nutrient inputs. An acidification index defined as the difference between excess SO/sub 4//sup 2 -/ and excess (Ca/sup 2 +/ + Mg/sup 2 +/) accounted for 74 percent of the variance in lake pH. Comparison of historical (late 1950s) and present data for pH, alkalinity, and excess SO/sub 4//sup 2 -/ indicated loss of alkalinity (> 25 ..mu..eq/L) and increases in excess SO/sub 4//sup 2 -/ (16-34 ..mu..eq/L) in several softwater lakes.

  17. Heterogeneous degradation of precipitated hexamine from wastewater by catalytic function of silicotungstic acid in the presence of H2O2 and H2O2/Fe2+.

    PubMed

    Taghdiri, Mehdi; Saadatjou, Naghi; Zamani, Navid; Farrokhi, Reyhaneh

    2013-02-15

    The industrial wastewater produced by hexamine plants is considered as a major environmental polluting factor due to resistance to biodegradation. So the treatment of such wastewater is required. In this work, the removal of hexamine from wastewater and its degradation have been studied. Hexamine was precipitated through formation of an insoluble and stable compound with silicotungstic acid. The oxidative heterogeneous degradation of precipitated hexamine was carried out with hydrogen peroxide (H(2)O(2)) aqueous solution and H(2)O(2)/Fe(2+) under the catalysis of silicotungstic acid. The operating conditions including amount of precipitate, hydrogen peroxide and ferrous ion dosage, temperature, time and pH were optimized by evaluating the removal of total organic carbon from system. A total organic carbon conversion higher than 70% was achieved in the presence of H(2)O(2)/Fe(2+). The experimental results showed that hexamine can be effectively degraded with H(2)O(2) and H(2)O(2)/Fe(2+) under the catalysis of silicotungstic acid. It was interesting that the solution of dissolved precipitate with H(2)O(2) can re-react with hexamine after the removal of excess hydrogen peroxide. This observation indicates the catalysis role of silicotungstic acid in the degradation of hexamine. A kinetic analysis based on total organic carbon reduction was carried out. The two steps mechanism was proposed for the degradation of hexamine.

  18. Citric acid cycle and role of its intermediates in metabolism.

    PubMed

    Akram, Muhammad

    2014-04-01

    The citric acid cycle is the final common oxidative pathway for carbohydrates, fats and amino acids. It is the most important metabolic pathway for the energy supply to the body. TCA is the most important central pathway connecting almost all the individual metabolic pathways. In this review article, introduction, regulation and energetics of TCA cycle have been discussed. The present study was carried out to review literature on TCA cycle.

  19. A perspective of stepwise utilisation of Bayer red mud: Step two--Extracting and recovering Ti from Ti-enriched tailing with acid leaching and precipitate flotation.

    PubMed

    Huang, Yanfang; Chai, Wencui; Han, Guihong; Wang, Wenjuan; Yang, Shuzhen; Liu, Jiongtian

    2016-04-15

    The extraction and recovery of Ti from Ti-enriched tailing with acid leaching and precipitate flotation, as one of the critical steps, was proposed for the stepwise utilization of red mud. The factors influencing acid leaching and precipitate flotation were examined by factorial design. The leaching thermodynamics, kinetics of Ti(4+), Al(3+) and Fe(3+), and the mechanism of selectively Fe(3+) removal using [Hbet][Tf2N] as precipitating reagent were discussed. The extracting of Ti(4+), Al(3+) and Fe(3+) in concentrated H2SO4 is controlled by diffusion reactions, depending mainly upon leaching time and temperature. The maximum extracting efficiency of Ti(4+) is approximately 92.3%, whereas Al(3+) and Fe(3+) leaching are respectively 75.8% and 84.2%. [Hbet][Tf2N], as a precipitating reagent, operates through a coordination mechanism in flotation. The pH value is the key factor influencing the flotation recovery of Ti(4+), whereas the dosage of precipitating reagent is that for Al(3+) recovery. The maximum flotation recovery of Ti(4+) is 92.7%, whereas the maximum Al(3+) recovery is 93.5%. The total recovery rate for extracting and recovering titanium is 85.5%. The liquor with Ti(4+) of 15.5g/L, Al(3+) of 30.4g/L and Fe(3+) of 0.48g/L was obtained for the following hydrolysis step in the integrated process for red mud utilisation.

  20. Molecularly imprinted microspheres and nanoparticles prepared using precipitation polymerisation method for selective extraction of gallic acid from Emblica officinalis.

    PubMed

    Pardeshi, Sushma; Dhodapkar, Rita; Kumar, Anupama

    2014-03-01

    This paper reports the preparation of gallic acid (GA) molecularly imprinted polymers (MIPs) by the precipitation polymerisation and highlights the effect of porogen on particle size and specific molecular recognition properties. MIP, M-100 prepared in the porogen acetonitrile and MIP, M-75 prepared in a mixture of acetonitrile-toluene (75:25 v/v), resulted in the formation of microspheres with approximately 4μm particle size and surface area of 96.73m(2)g(-1) and nanoparticles (0.8-1000nm) and a surface area of 345.9m(2)g(-1), respectively. The Langmuir-Freundlich isotherm study revealed that M-75 has comparatively higher number of binding sites which are homogenous and has higher affinity for GA. The MIPs selectively recognised GA in presence of its structural analogues. Pure GA with percent recovery of 75 (±1.6) and 83.4 (±2.2) was obtained from the aqueous extract of Emblica officinalis by M-100 and M-75, respectively and hot water at 60°C served as the eluting solvent.

  1. Zirconium(IV) tungstate nanoparticles prepared through chemical co-precipitation method and its function as solid acid catalyst

    NASA Astrophysics Data System (ADS)

    Sadanandan, Manoj; Bhaskaran, Beena

    2014-08-01

    In this paper, we report the synthesis of zirconium(IV) tungstate nanoparticles, a new and efficient catalyst for the oxidation of benzyl alcohol and esterification of acetic acid with various alcohols. The nanoparticle catalyst was prepared using the room temperature chemical co-precipitation method. The catalyst was characterized with thermogravimetric and differential thermal analysis, elemental analysis, X-ray diffraction analysis (XRD), fourier transform infrared spectroscopy (FT-IR), high-resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM) and the Brunauer-Emmett-Teller (BET) surface area. The crystallite size was found to be ~20 nm as revealed by XRD, HRTEM and AFM. The Na+ exchange capacity was found to be 2.76 meq g-1 and the surface area of the compound measured using BET method was found to be 250-265 m2 g-1. The high value of ion exchange capacity indicates the presence of surface hydroxyl groups. The prepared nanoparticles have proven to be excellent catalysts for both oxidation and ester synthesis under mild reaction conditions. The mechanism of the catalytic reaction was studied as well.

  2. The effects of acid precipitation runoff episodes on reservoir and tapwater quality in an Appalachian Mountain water supply.

    PubMed Central

    Sharpe, W E; DeWalle, D R

    1990-01-01

    The aluminum concentration and Ryznar Index increased and the pH decreased in a small Appalachian water supply reservoir following acid precipitation runoff episodes. Concomitant increases in tapwater aluminum and decreases in tapwater pH were also observed at two homes in the water distribution system. Lead concentrations in the tapwater of one home frequently exceeded recommended levels, although spatial and temporal variation in tapwater copper and lead concentrations was considerable. Since source water and reservoir water copper and lead concentrations were much lower, the increased copper and lead concentrations in tapwater were attributed to corrosion of household plumbing. Tapwater copper concentration correlated well with tapwater pH and tapwater temperature. Asbestos fibers were not detected in tapwater. The asbestos-cement pipe in the water distribution system was protected by a spontaneous metallic coating that inhibited fiber release from the pipe. Several simultaneous reactions were hypothesized to be taking place in the distribution system that involved corrosion of metallic components and coating of asbestos-cement pipe components in part with corrosion products and in part by cations of watershed origin. Greater water quality changes might be expected in areas of higher atmospheric deposition. Images FIGURE 5. FIGURE 6. PMID:2088742

  3. Response of surface water chemistry to reduced levels of acid precipitation: Comparison of trends in two regions of New York, USA

    USGS Publications Warehouse

    Burns, Douglas A.; McHale, M.R.; Driscoll, C.T.; Roy, K.M.

    2006-01-01

    In light of recent reductions in sulphur (S) and nitrogen (N) emissions mandated by Title IV of the Clean Air Act Amendments of 1990, temporal trends and trend coherence in precipitation (1984-2001 and 1992-2001) and surface water chemistry (1992-2001) were determined in two of the most acid-sensitive regions of North America, i.e. the Catskill and Adirondack Mountains of New York. Precipitation chemistry data from six sites located near these regions showed decreasing sulphate (SO42-), nitrate (NO3-), and base cation (CB) concentrations and increasing pH during 1984-2001, but few significant trends during 1992-2001. Data from five Catskill streams and 12 Adirondack lakes showed decreasing trends in SO42- concentrations at all sites, and decreasing trends in NO3-, CB, and H+ concentrations and increasing trends in dissolved organic carbon at most sites. In contrast, acid-neutralizing capacity (ANC increased significantly at only about half the Adirondack lakes and in one of the Catskill streams. Flow correction prior to trend analysis did not change any trend directions and had little effect on SO42- trends, but it caused several significant non-flow-corrected trends in NO3- and ANC to become non-significant, suggesting that trend results for flow-sensitive constituents are affected by flow-related climate variation. SO42- concentrations showed high temporal coherence in precipitation, surface waters, and in precipitation-surface water comparisons, reflecting a strong link between S emissions, precipitation SO42- concentrations, and the processes that affect S cycling within these regions. NO3- and H+ concentrations and ANC generally showed weak coherence, especially in surface waters and in precipitation-surface water comparisons, indicating that variation in local-scale processes driven by factors such as climate are affecting trends in acid-base chemistry in these two regions. Copyright ?? 2005 John Wiley & Sons, Ltd.

  4. PICMG xTCA Standards Extensions for Physics: New Developments & Future Plans

    SciTech Connect

    Larsen, R.S.; /SLAC

    2010-08-26

    After several years of planning and workshop meetings, a decision was reached in late 2008 to organize PICMG xTCA for Physics Technical Subcommittees to extend the ATCA and MTCA telecom standards for enhanced system performance, availability and interoperability for physics controls and applications hardware and software. Since formation in May-June 2009, the Hardware Technical Subcommittee has developed a number of ATCA, ARTM, AMC, MTCA and RTM extensions to be completed in mid-to-late 2010. The Software Technical Subcommittee is developing guidelines to promote interoperability of modules designed by industry and laboratories, in particular focusing on middleware and generic application interfaces such as Standard Process Model, Standard Device Model and Standard Hardware API. The paper describes the prototype design work completed by the lab-industry partners to date, the timeline for hardware releases to PICMG for approval, and the status of the software guidelines roadmap. The paper also briefly summarizes the program of the 4th xTCA for Physics Workshop immediately preceding the RT2010 Conference. he case for developing ATCA and MicroTCA (xTCA) specification extensions for physics has been covered in several previous papers. Briefly, ATCA and MicroTCA is the first all-serial communication platform available to the physics community to support both massively complex accelerator controls and massively large, high bandwidth and throughput experimental data acquisition systems. The major strength of xTCA is its multi-layer highly scalable managed platform architecture designed to achieve the highest possible system availability. Physics research imaging technologies have driven industrial applications in a wide range of medical scanners, for example, and in turn continue to evolve to exponentially higher speeds and resolution through new computer, communications industry and analog-to-digital conversion chip developments. The high availability managed platform is

  5. Selective Precipitation of Thorium lodate from a Tartaric Acid-Hydrogen Peroxide Medium Application to Rapid Spectrophotometric Determination of Thorium in Silicate Rocks and in Ores

    USGS Publications Warehouse

    Grimaldi, F.S.

    1957-01-01

    This paper presents a selective iodate separation of thorium from nitric acid medium containing d-tartaric acid and hydrogen peroxide. The catalytic decomposition of hydrogen peroxide is prevented by the use of 8quinolinol. A few micrograms of thorium are separated sufficiently clean from 30 mg. of such oxides as cerium, zirconium, titanium, niobium, tantalum, scandium, or iron with one iodate precipitation to allow an accurate determination of thorium with the thoronmesotartaric acid spectrophotometric method. The method is successful for the determination of 0.001% or more of thorium dioxide in silicate rocks and for 0.01% or more in black sand, monazite, thorite, thorianite, eschynite, euxenite, and zircon.

  6. Expression of the human isoform of glutamate dehydrogenase, hGDH2, augments TCA cycle capacity and oxidative metabolism of glutamate during glucose deprivation in astrocytes.

    PubMed

    Nissen, Jakob D; Lykke, Kasper; Bryk, Jaroslaw; Stridh, Malin H; Zaganas, Ioannis; Skytt, Dorte M; Schousboe, Arne; Bak, Lasse K; Enard, Wolfgang; Pääbo, Svante; Waagepetersen, Helle S

    2017-03-01

    A key enzyme in brain glutamate homeostasis is glutamate dehydrogenase (GDH) which links carbohydrate and amino acid metabolism mediating glutamate degradation to CO2 and expanding tricarboxylic acid (TCA) cycle capacity with intermediates, i.e. anaplerosis. Humans express two GDH isoforms, GDH1 and 2, whereas most other mammals express only GDH1. hGDH1 is widely expressed in human brain while hGDH2 is confined to astrocytes. The two isoforms display different enzymatic properties and the nature of these supports that hGDH2 expression in astrocytes potentially increases glutamate oxidation and supports the TCA cycle during energy-demanding processes such as high intensity glutamatergic signaling. However, little is known about how expression of hGDH2 affects the handling of glutamate and TCA cycle metabolism in astrocytes. Therefore, we cultured astrocytes from cerebral cortical tissue of hGDH2-expressing transgenic mice. We measured glutamate uptake and metabolism using [(3) H]glutamate, while the effect on metabolic pathways of glutamate and glucose was evaluated by use of (13) C and (14) C substrates and analysis by mass spectrometry and determination of radioactively labeled metabolites including CO2 , respectively. We conclude that hGDH2 expression increases capacity for uptake and oxidative metabolism of glutamate, particularly during increased workload and aglycemia. Additionally, hGDH2 expression increased utilization of branched-chain amino acids (BCAA) during aglycemia and caused a general decrease in oxidative glucose metabolism. We speculate, that expression of hGDH2 allows astrocytes to spare glucose and utilize BCAAs during substrate shortages. These findings support the proposed role of hGDH2 in astrocytes as an important fail-safe during situations of intense glutamatergic activity. GLIA 2017;65:474-488.

  7. PRECIPITATION OF PROTACTINIUM

    DOEpatents

    Moore, R.L.

    1958-07-15

    An lmprovement in the separation of protactinium from aqueous nitric acid solutions is described. 1t covers the use of lead dioxide and tin dioxide as carrier precipitates for the protactinium. In carrying out the process, divalent lead or divalent tin is addcd to the solution and oxidized, causing formation of a carrier precipitate of lead dioxide or stannic oxide, respectively.

  8. The precipitation of indium at elevated pH in a stream influenced by acid mine drainage.

    PubMed

    White, Sarah Jane O; Hussain, Fatima A; Hemond, Harold F; Sacco, Sarah A; Shine, James P; Runkel, Robert L; Walton-Day, Katherine; Kimball, Briant A

    2017-01-01

    Indium is an increasingly important metal in semiconductors and electronics and has uses in important energy technologies such as photovoltaic cells and light-emitting diodes (LEDs). One significant flux of indium to the environment is from lead, zinc, copper, and tin mining and smelting, but little is known about its aqueous behavior after it is mobilized. In this study, we use Mineral Creek, a headwater stream in southwestern Colorado severely affected by heavy metal contamination as a result of acid mine drainage, as a natural laboratory to study the aqueous behavior of indium. At the existing pH of ~3, indium concentrations are 6-29μg/L (10,000× those found in natural rivers), and are completely filterable through a 0.45μm filter. During a pH modification experiment, the pH of the system was raised to >8, and >99% of the indium became associated with the suspended solid phase (i.e. does not pass through a 0.45μm filter). To determine the mechanism of removal of indium from the filterable and likely primarily dissolved phase, we conducted laboratory experiments to determine an upper bound for a sorption constant to iron oxides, and used this, along with other published thermodynamic constants, to model the partitioning of indium in Mineral Creek. Modeling results suggest that the removal of indium from the filterable phase is consistent with precipitation of indium hydroxide from a dissolved phase. This work demonstrates that nonferrous mining processes can be a significant source of indium to the environment, and provides critical information about the aqueous behavior of indium.

  9. The precipitation of indium at elevated pH in a stream influenced by acid mine drainage

    USGS Publications Warehouse

    White, Sarah Jane O.; Hussain, Fatima A.; Hemond, Harold F.; Sacco, Sarah A.; Shine, James P.; Runkel, Robert L.; Walton-Day, Katherine; Kimball, Briant A.

    2017-01-01

    Indium is an increasingly important metal in semiconductors and electronics and has uses in important energy technologies such as photovoltaic cells and light-emitting diodes (LEDs). One significant flux of indium to the environment is from lead, zinc, copper, and tin mining and smelting, but little is known about its aqueous behavior after it is mobilized. In this study, we use Mineral Creek, a headwater stream in southwestern Colorado severely affected by heavy metal contamination as a result of acid mine drainage, as a natural laboratory to study the aqueous behavior of indium. At the existing pH of ~ 3, indium concentrations are 6–29 μg/L (10,000 × those found in natural rivers), and are completely filterable through a 0.45 μm filter. During a pH modification experiment, the pH of the system was raised to > 8, and > 99% of the indium became associated with the suspended solid phase (i.e. does not pass through a 0.45 μm filter). To determine the mechanism of removal of indium from the filterable and likely primarily dissolved phase, we conducted laboratory experiments to determine an upper bound for a sorption constant to iron oxides, and used this, along with other published thermodynamic constants, to model the partitioning of indium in Mineral Creek. Modeling results suggest that the removal of indium from the filterable phase is consistent with precipitation of indium hydroxide from a dissolved phase. This work demonstrates that nonferrous mining processes can be a significant source of indium to the environment, and provides critical information about the aqueous behavior of indium.

  10. Preparation and adsorption properties of molecularly imprinted polymer via RAFT precipitation polymerization for selective removal of aristolochic acid I.

    PubMed

    Xiao, Yonghua; Xiao, Rong; Tang, Jian; Zhu, Qiankun; Li, Xiaoming; Xiong, Yan; Wu, Xuewen

    2017-01-01

    The molecularly imprinted polymers (MIP) were prepared via aqueous RAFT precipitation polymerization, with aristolochic acid I (AAI) as the template molecule, AA as the functional monomer, EGDMA as the cross-linker, AIBN as the chain initiator, CTP as the chain transfer agent and 80% (g/g) DMF-aqueous solution as the porogen. The differential UV-vis spectra revealed that a cooperative hydrogen-bonding complex between AAI and AA might be formed at the molar ratio of 1:3 in prepolymerized system. The synthesized MIPs were characterized by FTIR spectra, solid UV-visible absorption spectra, nitrogen adsorption-desorption isotherms and scanning electron microscope, which proved that the MIPs and NIPs have the similar chemical structures and the adding of AAI could affect the size and morphology of the microspheres. UV-visible absorption spectra and High-performance liquid chromatography (HPLC) was used to investigate the adsorption and recognition properties of the MIPs. The Scatchard isotherm model described that the binding sites independently acted. The Langmuir isotherm model suggested an excellent imprinting effect owing to the presence of a large number of specific binding sites on the MIP. The Freundlich model indicated that the AAI could be readily absorbed by MIP. Selective absorption of the template molecule was demonstrated in presence of its analogous compounds, benzoic acid and nitrobenzene. The recycling experiments implied that the MIP could be reused to further selective recognition and separation to AAI for six times at least. MIP was developed for removal of AAI from the Aristolochia manshuriensis extraction. The results indicated that 25mg of MIP could remove the AAI below the HPLC detection limits (6.47ngmL(-1)) from 5.0mL of the extraction (CAAI=0.0018mgmL(-1)) with the recovery of AAI to 91.50% (n=3, SD=4.24%). Therefore, it is clearly revealed that the MIP can be a useful tool to remove toxic compounds from natural products.

  11. Bioavailability of zinc to rats from defatted soy flour, acid-precipitated soy concentrate and neutralized soy concentrate as determined by intrinsic and extrinsic labeling techniques

    SciTech Connect

    Ketelsen, S.M.; Stuart, M.A.; Weaver, C.M.; Forbes, R.M.; Erdman, J.W. Jr.

    1984-03-01

    The bioavailability of 65Zn from intrinsically and extrinsically labeled soy flour, acid-precipitated soy concentrate and neutralized soy concentrate was evaluated in rats. Weanling rats were fed marginally zinc-deficient diets, providing 8 ppm zinc from one of these three soy products, for 7 days. The rats then received a radioactively labeled test meal, identical in composition to the previous diet except that the soy product was either intrinsically or extrinsically labeled with 65Zn. After the test meal the rats were again fed diets the same as those consumed prior to the test meal. Whole-body retention of 65Zn at 24 hours and 12 days as well as 65Zn retained in tibias of rats given meals containing neutralized concentrate-based meals was significantly lower than for rats given meals containing the soy flour or acid-precipitated concentrate. In addition, retention of 65Zn from the extrinsically labeled acid-precipitated concentrate-based meal was significantly higher than from the same product intrinsically labeled. These findings confirm the results of previous feeding studies from which it was suggested that neutralization of soy protein concentrates reduces zinc bioavailability to the rat. In addition, the results are taken to suggest that experimental conditions may influence the validity of the extrinsic labeling technique for zinc.

  12. Effects of acidic precipitation on the water quality of streams in the Laurel Hill area, Somerset County, Pennsylvania, 1983-86

    USGS Publications Warehouse

    Barker, J.L.; Witt, E. C.

    1990-01-01

    Five headwater streams in the Laurel Hill area in southwestern Pennsylvania were investigated from September 1983 through February 1986 to determine possible effects of acidic precipitation on water quality. Precipitation in the Laurel Hill area is among the most acidic in the Nation, with a mean volume-weighted pH of 4.06. Sulfate is the dominant acid-forming anion, averaging 3.6 milligrams per liter or about 50 kilograms per hectare in wet deposition alone. Nitrate averages about 2 milligrams per liter or 7 kilograms per hectare in the study area. Stream chemistry in the five streams is quite variable and apparently is influenced to a large degree by the bedrock geology and by small amounts of alkaline material in watershed soils. Three of the five streams with no or little acid-neutralizing capacity presently are devoid of fish because of low pH and elevated aluminum concentrations. Aluminum concentrations increase in the other two streams during rainfall and snowmelt despite comparatively higher base flow and acid-neutralizing capacities. Comparison of the chemistry of streamflow during 14 storm events at South Fork Bens Creek and North Fork Bens Creek reveals similar chemical responses when discharge suddenly increases. Concentrations of dissolved metals and sulfate increased during stormflow and snowmelt runoff, whereas concentrations of base cations, silica, and chloride decreased. Nitrate concentrations were not affected by rainfall runoff by tended to increase with snowmelt runoff.

  13. Synthesis of aqueous suspensions of magnetic nanoparticles with the co-precipitation of iron ions in the presence of aspartic acid

    NASA Astrophysics Data System (ADS)

    Pušnik, Klementina; Goršak, Tanja; Drofenik, Miha; Makovec, Darko

    2016-09-01

    There is increasing demand for the production of large quantities of aqueous suspensions of magnetic iron-oxide nanoparticles. Amino acids are one possible type of inexpensive, nontoxic, and biocompatible molecules that can be used as the surfactants for the preparation of stable suspensions. This preparation can be conducted in a simple, one-step process based on the co-precipitation of Fe3+/Fe2+ ions in the presence of the amino acid. However, the presence of this amino acid changes the mechanism of the magnetic nanoparticles' formation. In this investigation we analyzed the influence of aspartic amino acid (Asp) on the formation of magnetic iron-oxide nanoparticles during the co-precipitation. The process of the nanoparticles' formation was followed using a combination of TEM, x-ray diffractometry, magnetic measurements, in-situ FT-IR spectroscopy, and chemical analysis, and compared with the formation of nanoparticles without the Asp. The Asp forms a coordination complex with the Fe3+ ions, which impedes the formation of the intermediate iron oxyhydroxide phase and suppresses the growth of the final magnetic iron-oxide nanoparticles. Slower reaction kinetics can lead to the formation of nonmagnetic secondary phases. The aspartic-acid-absorbed nanoparticles can be dispersed to form relatively concentrated aqueous suspensions displaying a good colloidal stability at an increased pH.

  14. Caprylic acid-induced impurity precipitation from protein A capture column elution pool to enable a two-chromatography-step process for monoclonal antibody purification.

    PubMed

    Zheng, Ji; Wang, Lu; Twarowska, Barbara; Laino, Sarah; Sparks, Colleen; Smith, Timothy; Russell, Reb; Wang, Michelle

    2015-01-01

    This article presents the use of caprylic acid (CA) to precipitate impurities from the protein A capture column elution pool for the purification of monoclonal antibodies (mAbs) with the objective of developing a two chromatography step antibody purification process. A CA-induced impurity precipitation in the protein A column elution pool was evaluated as an alternative method to polishing chromatography techniques for use in the purification of mAbs. Parameters including pH, CA concentrations, mixing time, mAb concentrations, buffer systems, and incubation temperatures were evaluated on their impacts on the impurity removal, high-molecular weight (HMW) formation and precipitation step yield. Both pH and CA concentration, but not mAb concentrations and buffer systems, are key parameters that can affect host-cell proteins (HCPs) clearance, HMW species, and yield. CA precipitation removes HCPs and some HMW species to the acceptable levels under the optimal conditions. The CA precipitation process is robust at 15-25°C. For all five mAbs tested in this study, the optimal CA concentration range is 0.5-1.0%, while the pH range is from 5.0 to 6.0. A purification process using two chromatography steps (protein A capture column and ion exchange polishing column) in combination with CA-based impurity precipitation step can be used as a robust downstream process for mAb molecules with a broad range of isoelectric points. Residual CA can be effectively removed by the subsequent polishing cation exchange chromatography.

  15. Treatment technologies and mechanisms for three odorants at trace level: IPMP, IBMP, and TCA.

    PubMed

    Li, Xin; Lin, Pengfei; Wang, Jun; Liu, Yuanyuan; Li, Yong; Zhang, Xiaojian; Chen, Chao

    2016-01-01

    Odour episodes caused by algal metabolites are gaining more and more attention in recent years. Besides geosmin and 2-methylisoborneol (MIB), 2-isopropyl-3-methoxypyrazine (IPMP), 2-isobutyl-3-methoxypyrazine (IBMP), and 2,4,6-trichloroanisole (TCA) have emerged to be important off-flavour sources. Their low odour threshold concentrations (several ng ·L(-1)), which are even lower than those of MIB and geosmin, pose challenges for treatment strategies. Hence, a practical and efficient mitigation technology is needed. The possible practical technologies, including powdered activated carbon (PAC) adsorption and oxidation by chlorine and potassium permanganate, were investigated. The results indicated that chlorine and potassium permanganate oxidation of the three odorants were unfeasible while PAC adsorption was effective. As for adsorption, TCA, followed by IBMP and IPMP, was most easily removed by PAC. The Freundlich model could well describe the adsorption isotherm data. The adsorption capacities for IPMP, IBMP, and TCA were described as follows: [Formula: see text], [Formula: see text], and [Formula: see text]. For five earthy/musty odorants including geosmin and MIB, octanol/water partition coefficient, molecular weight, and polarizability all promoted adsorption while aqueous solubility showed a negative influence. The hydrophobic interaction was believed to be the dominant force in the adsorption mechanism while the π-electron interaction enhanced adsorption when a benzene ring was present. This result could be used to predict the adsorption performance of emerging odorants.

  16. Partial reverse of the TCA cycle is enhanced in Taenia crassiceps experimental neurocysticercosis after in vivo treatment with anthelminthic drugs.

    PubMed

    de Almeida Leandro, Leticia; Fraga, Carolina Miguel; de Souza Lino, Ruy; Vinaud, Marina Clare

    2014-04-01

    Neurocysticercosis (NCC) is the most common helminthic infection and neglected disease of the central nervous system. It is the leading cause of acquired epilepsy and seizures worldwide. Therefore, to study this important neglected disease, it is important to use experimental models. There is no report in the literature on how the parasite's metabolism reacts to antihelminthic treatment when it is still within the central nervous system of the host. Therefore, the aim of this study was to investigate the energetic metabolism of cysticerci experimentally inoculated in the encephala of BALB/c mice after treatment with low dosages (not sufficient to kill the parasite) of albendazole (ABDZ) and praziquantel (PZQ). BALB/c mice were intracranially inoculated with Taenia crassiceps cysticerci and, after 30 days, received treatment with low dosages of ABDZ and PZQ. After 24 h of treatment, the mice were euthanized, and the cysticerci were removed and analyzed through high-performance liquid chromatography (HPLC) to quantify the organic acids related to the energetic metabolism of the parasite. The partial reverse of the TCA cycle was enhanced by the ABDZ and PZQ treatments both with the higher dosage, as the organic acids of this pathway were significantly increased when compared to the control group and to the other dosages. In conclusion, it was possible to detect the increase of this pathway in the parasites that were exposed to low dosages of ABDZ and PZQ, as it is a mechanism that would amplify the energy production in a hostile environment.

  17. Modeling Precipitation and Sorption of Al, U and Co-contaminants during Titration of Acidic Sediments in Recirculation Flow-Through Experiments

    SciTech Connect

    Tang, Guoping; Luo, Wensui; Brooks, Scott C; Watson, David B; Gu, Baohua

    2013-01-01

    We conducted batch and recirculating column titration tests with contaminated acidic sediments with controlled CO2 in the headspace, and extended the geochemical model by Gu et al. (2003, GCA) to better understand and quantify the reactions governing trace metal fate in the subsurface. The sediment titration curve showed slow pH increase due to strong buffering by Al precipitation and CO2 uptake. Assuming precipitation of basaluminite at low saturation index (SI=-4), and decreasing cation exchange selectivity coefficient (kNa\\Al=0.3), the predictions are close to the observed pH and Al; and the model explains 1) the observed Ca, Mg, and Mn concentration decrease by cation exchange with sorbed Al, and 2) the decrease of U by surface complexation with Fe hydroxides at low pH, and precipitation as liebigite (Ca2UO2(CO3)3:10H2O) at pH>5.5. Without further adjustment geochemical parameters, the model describes reasonably well previous sediment and column titration tests without CO2 in the headspace, as well as the new large column test. The apparent inhibition of U and Ni decrease in the large column can be explained by formation of aqueous carbonate complexes and/or competition with carbonate for surface sites. These results indicated that ignoring labile solid phase Al would underestimate base requirement in titration of acidic aquifers.

  18. Preparation of porous carboxymethyl chitosan grafted poly (acrylic acid) superabsorbent by solvent precipitation and its application as a hemostatic wound dressing.

    PubMed

    Chen, Yu; Zhang, Yong; Wang, Fengju; Meng, Weiwei; Yang, Xinlin; Li, Peng; Jiang, Jianxin; Tan, Huimin; Zheng, Yongfa

    2016-06-01

    The volume phase transition of a hydrogel initiated by shrinking may result in complex patterns on its surface. Based on this unique property of hydrogel, we have developed a novel solvent precipitation method to prepare a kind of novel superabsorbent polymers with excellent hemostatic properties. A porous carboxymethyl chitosan grafted poly (acrylic acid) (CMCTS-g-PAA) superabsorbent polymer was prepared by precipitating CMCTS-g-PAA hydrogel with ethanol. Its potential application in hemostatic wound dressing was investigated. The results indicate that the modified superabsorbent polymer is non-cytotoxic. It showed a high swelling capacity and better hemostatic performance in the treatments of hemorrhage model of ear artery, arteria cruralis and spleen of the New Zealand white rabbit than the unmodified polymer and other commonly used clinic wound dressings. The hemostatic mechanism of the porous CMCTS-g-PAA polymer was also discussed.

  19. Application of dissolvable layered double hydroxides as sorbent in dispersive solid-phase extraction and extraction by co-precipitation for the determination of aromatic acid anions.

    PubMed

    Tang, Sheng; Lee, Hian Kee

    2013-08-06

    Three types of magnesium-aluminum layered double hydroxides were synthesized and employed as solid-phase extraction (SPE) sorbents to extract several aromatic acids (protocatechuic acid, mandelic acid, phthalic acid, benzoic acid, and salicylic acid) from aqueous samples. An interesting feature of these sorbents is that they dissolve when the pH of the solution is lower than 4. Thus, the analyte elution step, as needed in conventional sorbent-based extraction, was obviated by dissolving the sorbent in acid after extraction and separation from the sample solution. The extract was then directly injected into a high-performance liquid chromatography-ultraviolet detection system for analysis. In the key adsorption process, both dispersive SPE and co-precipitation extraction with the sorbents were conducted and experimental parameters such as pH, temperature, and extraction time were optimized. The results showed that both extraction methods provided low limits of detection (0.03-1.47 μg/L) and good linearity (r(2) > 0.9903). The optimized extraction conditions were applied to human urine and sports drink samples. This new and interesting extraction approach was demonstrated to be a fast and efficient procedure for the extraction of organic anions from aqueous samples.

  20. Dwell Time and Surface Parameter Effects on Removal of Silicone Oil From D6ac Steel Using TCA

    NASA Technical Reports Server (NTRS)

    Boothe, R. E.

    2003-01-01

    This study was conducted to evaluate the impact of dwell time, surface roughness, and the surface activation state on 1,1,1-trichloroethane's (TCA's) effectiveness for removing silicone oil from D6ac steel. Silicone-contaminated test articles were washed with TCA solvent, and then the surfaces were analyzed for residue, using Fourier transform infrared spectroscopy. The predominant factor affecting the ability to remove the silicone oil was surface roughness.

  1. Acidification of soil-water in low base-saturated sand soils of the superior uplands under acid and normal precipitation.

    PubMed

    Harris, A R

    1989-04-01

    Lakes and streams are acidified by direct precipitation and water channeled through nearby soils, but water in low base-saturation soils can produce highly acidic percolate after prolonged contact and subsequent degassing in surface waters. Theories advanced by Reuss (1983), Reuss and Johnson (1985), and Seip and Rustad (1984) suggest that soils with less than 15% base saturation are susceptible to soil-water pH depression of up to 0.4 unit, which is sufficient to cause negative alkalinity in soil solutions. High concentrations of mobile anions (notably sulfate) are responsible for the negative alkalinity and these solutions on CO2 degassing in surface waters can retain acidities equivalent to a pH value of 5.0 or less. This mechanism purports to explain why some lakes acidify when they are surrounded by acid soils and cation leaching is not required.Ambient precipitation set to pH 5.4 and pH 4.2 was applied to columns of low base-saturated, sand, soils, starting in 1985. The columns (15 cm diameter and 150 cm long) were collected from soils with base saturations falling into one of three groups (0-10, 10-20, and 20-40%) from national forests in the Superior Uplands area (includes Boundary Waters Canoe Area, Rainbow Lakes, Sylvania, Moquah Barrens, and other Wilderness and Natural areas). The soils were Haplorthods and Udipsamments mainly from outwash plains.The soil columns were instrumented and reburied around a subterranean structure used to collect leachate water and to maintain natural temperature, air, and light conditions. Three humus treatments were applied to soil column (none, northern hardwood, and jack pine) to measure the effect of natural acidification compared to acidification by acid precipitation. The cores were treated with precipitation buffered to pH 5.4 to simulate natural rain and pH 4.2 to simulate acid rain.Columns were treated in 1985 and 1986 with approximately 200 cm of buffered precipitation each year over the frost-free season. Data is

  2. Microbiological aspects of determination of trichloroacetic acid in soil.

    PubMed

    Matucha, M; Gryndler, M; Uhlírová, H; Fuksová, K; Rohlenová, J; Forczek, S T; Schröder, P

    2004-01-01

    Soils have been shown to possess a strong microbial trichloroacetic acid (TCA)-degrading activity. High TCA-degradation rate was also observed during soil extraction with water. For correct measurements of TCA levels in soil all TCA-degrading activities have to be inhibited immediately after sampling before analysis. We used rapid freezing of soil samples (optimally in liquid nitrogen) with subsequent storage and slow thawing before analysis as an efficient technique for suppressing the degradation. Frozen soil samples stored overnight at -20 degrees C and then thawed slowly exhibited very low residual TCA-degrading activity for several hours. Omitting the above procedure could lead to the confusing differences between the TCA levels previously reported in the literature.

  3. Synthesis and evaluation of uniformly sized nalidixic acid-imprinted nanospheres based on precipitation polymerization method for analytical and biomedical applications.

    PubMed

    Abouzarzadeh, Atefeh; Forouzani, Mehdi; Jahanshahi, Mohsen; Bahramifar, Nader

    2012-07-01

    For the first time in this work, uniform molecularly imprinted polymer (MIP) nanoparticles were prepared using nalidixic acid as a template. The MIP nanoparticles were successfully synthesized by precipitation polymerization applying methacrylic acid (MAA) as a functional monomer and trimethylolpropane trimethacrylate (TRIM) as a cross-linking monomer at different mole ratios. The morphology, binding, recognition, selectivity, and in vitro release behaviors of obtained particles were studied. The produced polymers were characterized by Fourier transform infrared spectroscopy and differential scanning calorimetric. Furthermore, their morphology was analyzed accurately by scanning electron microscopy, photon correlation spectroscopy, and Brunauer-Emmett-Teller analysis. The nanospheres and microspheres with mean diameter values of 94 nm, 256 nm, and 1.2 µm were obtained using nalidixic acid-MAA-TRIM various mole ratios. Among the MIPs, the product with nalidixic acid-MAA-TRIM mole ratio of 1:12:12 established nanospheres with the lowest polydispersity index (0.003), an average pore diameter (12 nm), and the highest specific surface area (280 m(2) g(-1)) and selectivity factor (10.4). Results from binding experiments demonstrated that the imprinted nanospheres with a 94-nm mean diameter and a binding capacity of 28 mg of nalidixic acid per gram of polymer had higher specific affinity to nalidixic acid in contrast with the other imprinted nanospheres, microspheres, and nonimprinted particles. However, the binding performance of imprinted nanospheres in human serum was estimated using high-performance liquid chromatography analysis (binding approximately 98% of nalidixic acid). In addition, release experiments proved to be successful in the controlled release of nalidixic acid during a long period. The 20% of loaded nalidixic acid was released from the imprinted nanospheres within the first 20 h, whereas the remaining 80% was released in the after 120 h. The nalidixic

  4. Mitochondria-Translocated PGK1 Functions as a Protein Kinase to Coordinate Glycolysis and the TCA Cycle in Tumorigenesis.

    PubMed

    Li, Xinjian; Jiang, Yuhui; Meisenhelder, Jill; Yang, Weiwei; Hawke, David H; Zheng, Yanhua; Xia, Yan; Aldape, Kenneth; He, Jie; Hunter, Tony; Wang, Liwei; Lu, Zhimin

    2016-03-03

    It is unclear how the Warburg effect that exemplifies enhanced glycolysis in the cytosol is coordinated with suppressed mitochondrial pyruvate metabolism. We demonstrate here that hypoxia, EGFR activation, and expression of K-Ras G12V and B-Raf V600E induce mitochondrial translocation of phosphoglycerate kinase 1 (PGK1); this is mediated by ERK-dependent PGK1 S203 phosphorylation and subsequent PIN1-mediated cis-trans isomerization. Mitochondrial PGK1 acts as a protein kinase to phosphorylate pyruvate dehydrogenase kinase 1 (PDHK1) at T338, which activates PDHK1 to phosphorylate and inhibit the pyruvate dehydrogenase (PDH) complex. This reduces mitochondrial pyruvate utilization, suppresses reactive oxygen species production, increases lactate production, and promotes brain tumorigenesis. Furthermore, PGK1 S203 and PDHK1 T338 phosphorylation levels correlate with PDH S293 inactivating phosphorylation levels and poor prognosis in glioblastoma patients. This work highlights that PGK1 acts as a protein kinase in coordinating glycolysis and the tricarboxylic acid (TCA) cycle, which is instrumental in cancer metabolism and tumorigenesis.

  5. Possible Links Between Stress Defense and the Tricarboxylic Acid (TCA) Cycle in Francisella Pathogenesis*

    PubMed Central

    Dieppedale, Jennifer; Gesbert, Gael; Ramond, Elodie; Chhuon, Cerina; Dubail, Iharilalao; Dupuis, Marion; Guerrera, Ida Chiara; Charbit, Alain

    2013-01-01

    Francisella tularensis is a highly infectious bacterium causing the zoonotic disease tularemia. In vivo, this facultative intracellular bacterium survives and replicates mainly in the cytoplasm of infected cells. We have recently identified a genetic locus, designated moxR that is important for stress resistance and intramacrophage survival of F. tularensis. In the present work, we used tandem affinity purification coupled to mass spectrometry to identify in vivo interacting partners of three proteins encoded by this locus: the MoxR-like ATPase (FTL_0200), and two proteins containing motifs predicted to be involved in protein–protein interactions, bearing von Willebrand A (FTL_0201) and tetratricopeptide (FTL_0205) motifs. The three proteins were designated here for simplification, MoxR, VWA1, and TPR1, respectively. MoxR interacted with 31 proteins, including various enzymes. VWA1 interacted with fewer proteins, but these included the E2 component of 2-oxoglutarate dehydrogenase and TPR1. The protein TPR1 interacted with one hundred proteins, including the E1 and E2 subunits of both oxoglutarate and pyruvate dehydrogenase enzyme complexes, and their common E3 subunit. Remarkably, chromosomal deletion of either moxR or tpr1 impaired pyruvate dehydrogenase and oxoglutarate dehydrogenase activities, supporting the hypothesis of a functional role for the interaction of MoxR and TPR1 with these complexes. Altogether, this work highlights possible links between stress resistance and metabolism in F. tularensis virulence. PMID:23669032

  6. A phylogenetic approach to the early evolution of autotrophy: the case of the reverse TCA and the reductive acetyl-CoA pathways.

    PubMed

    Becerra, Arturo; Rivas, Mario; García-Ferris, Carlos; Lazcano, Antonio; Peretó, Juli

    2014-06-01

    In recent decades, a number of hypotheses on the autotrophic origin of life have been presented. These proposals invoke the emergence of reaction networks leading from CO or CO₂ to the organic molecules required for life. It has also been suggested that the last (universal) common ancestor (LCA or LUCA) of all extant cell lineages was a chemolitho-autotrophic thermophilic anaerobe. The antiquity of some carbon fixation pathways, the phylogenetic basal distribution of some autotrophic organisms, and the catalytic properties of iron-sulfur minerals have been advanced in support of these ideas. Here we critically examine the phylogenetic distribution and evolution of enzymes that are essential for two of the most ancient autotrophic means of metabolism: the reductive tricarboxylic acid (rTCA) cycle and the reductive acetyl-CoA pathway. Phylogenetic analysis of citryl-CoA synthetase and of citryl-CoA lyase, key enzymatic components of the rTCA cycle, and of CO dehydrogenase/acetyl-CoA synthase, a key enzyme in the reductive acetyl-CoA pathway, revealed that all three enzymes have undergone major lateral transfer events and therefore cannot be used as proof of the LCA's metabolic abilities nor as evidence of an autotrophic origin of life.

  7. Direct analysis for urinary protein with biuret reagent, with use of urine ultrafiltrate blanking: comparison with a manual biuret method involving trichloroacetic acid precipitation.

    PubMed

    Eckfeldt, J H; Kershaw, M J; Dahl, I I

    1984-03-01

    We describe a method for measuring urinary protein with a centrifugal analyzer. Biuret reagent is used, and blanking with an ultrafiltrate of urine eliminates interferences from the nonprotein, biuret-positive chromogens in urine. We compare results by this new method with those by a manual method in which trichloroacetic acid precipitation and biuret reagent are used. The new method shows good precision and excellent correlation (r = 0.997) with the manual method. The ease and convenience of this assay should make this a useful method for the routine clinical laboratory.

  8. Low-molecular-weight organic acids in the Tibetan Plateau: Results from one-year of precipitation samples at the SET station

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Kang, Shichang; Sun, Jimin; Wan, Xin; Wang, Yongjie; Gao, Shaopeng; Cong, Zhiyuan

    2014-04-01

    Background atmospheric organic acids: formic (F), acetic (A), oxalic (O), and methanesulfonic (MSA, abbreviated to M) acids in the southern Tibetan Plateau (TP), were determined in one-year of precipitation measurements at a remote alpine station. These organic acids were dominated by oxalic (volume-weighted mean of 0.51 μmol l-1)/formic acid (0.38 μmol l-1), followed by acetic acid (0.20 μmol l-1) and MSA (0.10 μmol l-1). Their levels were comparable with those from other remote sites, while they were lower than those found in populated areas. The South Asian monsoon is responsible for the seasonal variation of organic acid concentration: a relative abundance of MSA and lower concentrations of other organic acids (by the dilution effect) in the monsoon season, while opposite in the non-monsoon season. Diverse sources were identified by principal component analysis combined with the corresponding tracers. These were anthropogenic disturbances (which explain 41% of the variance), marine emission (24%), and biogenic emission (16%). Moreover, the variances of F/A, M/(F + A), and O/(F + A) in monsoonal versus non-monsoonal samples, were involved with the changes of sources. Furthermore, these chemical indexes suggest that active photochemistry over the TP was significant for the production of organic acids and consequently enhanced the ratios of M/(F + A) and O/(F + A) in monsoonal rainfalls. The elevated organic compounds within the ascending tropical moisture imply potential significances for the secondary formation of organic acids in the high-altitude and the changes of the Asian monsoon.

  9. The effect of using citric or acetic acid on survival of Listeria monocytogenes during fish protein recovery by isoelectric solubilization and precipitation process.

    PubMed

    Otto, R A; Beamer, S; Jaczynski, J; Matak, K E

    2011-10-01

    Isoelectric solubilization and precipitation (ISP) is a protein recovery process effective at reducing Listeria innocua, a nonpathogenic bacterium typically used as a surrogate for L. monocytogenes in recovered trout protein. The response of L. monocytogenes to ISP processing was determined and compared to the response of L. innocua. Headed and gutted rainbow trout were inoculated with L. monocytogenes (10.16 log CFU/g), homogenized, and pH-adjusted with granular citric acid (pH 2.0 and 2.5) or glacial acetic acid (pH 3.0 and 3.5). Proteins were solubilized and centrifugation was used to remove insoluble components (skin, insoluble protein, so on). The supernatant was returned to the protein isoelectric point (pH 5.5) with NaOH and centrifuged to remove precipitated protein. Microbial load was enumerated on both growth and selective media; recovery was not significantly different (P > 0.05). Surviving cells from each component (protein, insoluble, and water) were compared to initial inoculum numbers. Significant reductions were detected at all pH (P < 0.05). The greatest reductions were at pH 3.0 with acetic acid, with a mean log reduction of 3.03 in the combined components, and a 3.53 log reduction in the protein portion. Data were compared to results from a previous study using L. innocua. Significant differences (P < 0.05) in recovery were found between the 2 species at pH 2.0 and 3.0 with greater recovery of L. monocytogenes, regardless of processing pH or acid type. These results demonstrate the variability in resistance between species and indicate that L. innocua is not an appropriate surrogate for L. monocytogenes for ISP processing with organic acids.

  10. URANIUM PRECIPITATION PROCESS

    DOEpatents

    Thunaes, A.; Brown, E.A.; Smith, H.W.; Simard, R.

    1957-12-01

    A method for the recovery of uranium from sulfuric acid solutions is described. In the present process, sulfuric acid is added to the uranium bearing solution to bring the pH to between 1 and 1.8, preferably to about 1.4, and aluminum metal is then used as a reducing agent to convert hexavalent uranium to the tetravalent state. As the reaction proceeds, the pH rises amd a selective precipitation of uranium occurs resulting in a high grade precipitate. This process is an improvement over the process using metallic iron, in that metallic aluminum reacts less readily than metallic iron with sulfuric acid, thus avoiding consumption of the reducing agent and a raising of the pH without accomplishing the desired reduction of the hexavalent uranium in the solution. Another disadvantage to the use of iron is that positive ferric ions will precipitate with negative phosphate and arsenate ions at the pH range employed.

  11. Spur gears: Optimal geometry, methods for generation and Tooth Contact Analysis (TCA) program

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.; Zhang, Jiao

    1988-01-01

    The contents of this report include the following: (1) development of optimal geometry for crowned spur gears; (2) methods for their generation; and (3) tooth contact analysis (TCA) computer programs for the analysis of meshing and bearing contact on the crowned spur gears. The method developed for synthesis is used for the determination of the optimal geometry for crowned pinion surface and is directed to reduce the sensitivity of the gears to misalignment, localize the bearing contact, and guarantee the favorable shape and low level of the transmission errors. A new method for the generation of the crowned pinion surface has been proposed. This method is based on application of the tool with a surface of revolution that slightly deviates from a regular cone surface. The tool can be used as a grinding wheel or as a shaver. The crowned pinion surface can also be generated by a generating plane whose motion is provided by an automatic grinding machine controlled by a computer. The TCA program simulates the meshing and bearing contact of the misaligned gears. The transmission errors are also determined.

  12. Topology of modified helical gears and Tooth Contact Analysis (TCA) program

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.; Zhang, Jiao

    1989-01-01

    The contents of this report covers: (1) development of optimal geometries for crowned helical gears; (2) a method for their generation; (3) tooth contact analysis (TCA) computer programs for the analysis of meshing and bearing contact of the crowned helical gears; and (4) modelling and simulation of gear shaft deflection. The developed method for synthesis was used to determine the optimal geometry for a crowned helical pinion surface and was directed to localize the bearing contact and guarantee favorable shape and a low level of transmission errors. Two new methods for generation of the crowned helical pinion surface are proposed. One is based on the application of a tool with a surface of revolution that slightly deviates from a regular cone surface. The tool can be used as a grinding wheel or as a shaver. The other is based on a crowning pinion tooth surface with predesigned transmission errors. The pinion tooth surface can be generated by a computer-controlled automatic grinding machine. The TCA program simulates the meshing and bearing contact of the misaligned gears. The transmission errors are also determined. The gear shaft deformation was modelled and investigated. It was found that the deflection of gear shafts has the same effect as gear misalignment.

  13. ADVANCES IN BIOTREATMENT OF ACID MINE DRAINAGE AND BIORECOVERY OF METALS: 1. METAL PRECIPITATION FOR RECOVERY AND RECYCLE

    EPA Science Inventory

    Acid-mine drainage (AMD) is a severe pollution problem attributed to past mining activities. AMD is an acidic, metal-bearing wastewater generated by the oxidation of metal sulfides to sulfates by Thiobacillus bacteria in both active and abandoned mining operations. The wastewater...

  14. Determination of paclitaxel in hyaluronic acid polymeric micelles in rat blood by protein precipitation-micelle breaking method: application to a pharmacokinetic study.

    PubMed

    Liu, Yanhua; Sun, Jin; Lian, He; Li, Xin; Cao, Wen; Bai, Liming; Wang, Yongjun; He, Zhonggui

    2013-09-15

    An efficient dissociation of paclitaxel (PTX) from the home-made hyaluronic acid-octadecyl (HA-C18) polymeric micelles formulation in rat blood could not be achieved using previously published PTX analytical methods. So, we intended to develop the micelle-breaking method to determine paclitaxel encapsulated in the HA-C18 polymeric micelles in blood. The pretreatment method of blood samples adopted a simple one-step protein precipitation-micelle breaking process with methanol as micelle-breaking and protein precipitant solvents for complete extraction of PTX from HA-C18 micelles in blood. The micelle breaking efficiency of methanol was as high as 97.7%. Separation was carried out by gradient elution on an Acquity UPLC BEH C18 column with a mobile phase consisting of water (containing 0.1% formic acid) and acetonitrile. A total single run time was as short as 3.0min. Detection was performed by triple-quadrupole mass spectrometry with positive electrospray ionization as source ionization in multiple-reaction monitoring mode at m/z 854.3→286.2 for PTX and m/z 808.5→527.3 for the internal standard, docetaxel. The method demonstrated good linearity at the concentrations ranging from 20 to 10,000ng/mL. The intra- and inter-day relative standard deviations were less than 9.9%. The mean extraction recoveries of PTX and IS were 94.7% and 87.5%, respectively. In summary, the methanol protein precipitation-micelle breaking method could extract PTX completely from the polymeric micelles. Finally, the method was successfully applied to a pharmacokinetic study of the home-made PTX-loaded HA-C18 polymeric micelles and Taxol solution after intravenous administration in rats.

  15. The Aurora kinase A inhibitor TC-A2317 disrupts mitotic progression and inhibits cancer cell proliferation.

    PubMed

    Min, Yoo Hong; Kim, Wootae; Kim, Ja-Eun

    2016-12-20

    Mitotic progression is crucial for the maintenance of chromosomal stability. A proper progression is ensured by the activities of multiple kinases. One of these enzymes, the serine/threonine kinase Aurora A, is required for proper mitosis through the regulation of centrosome and spindle assembly. In this study, we functionally characterized a newly developed Aurora kinase A inhibitor, TC-A2317. In human lung cancer cells, TC-A2317 slowed proliferation by causing aberrant formation of centrosome and microtubule spindles and prolonging the duration of mitosis. Abnormal mitotic progression led to accumulation of cells containing micronuclei or multinuclei. Furthermore, TC-A2317-treated cells underwent apoptosis, autophagy or senescence depending on cell type. In addition, TC-A2317 inactivated the spindle assembly checkpoint triggered by paclitaxel, thereby exacerbating mitotic catastrophe. Consistent with this, the expression level of Aurora A in tumors was inversely correlated with survival in lung cancer patients. Collectively, these data suggest that inhibition of Aurora kinase A using TC-A2317 is a promising target for anti-cancer therapeutics.

  16. Upregulation of PTEN suppresses invasion in Tca8113 tongue cancer cells through repression of epithelial-mesenchymal transition (EMT).

    PubMed

    Xie, Siming; Lu, Zhiyuan; Lin, Yanzhu; Shen, Lijia; Yin, Cao

    2016-05-01

    We previously discovered that the expression of the tumor suppressor phosphatase and tensin homolog (PTEN) was downregulated in the majority patients with tongue squamous cell carcinoma (TSCC). The aim of this study was to investigate the role of PTEN overexpression in the regulation of epithelial-mesenchymal transition (EMT) of the tongue squamous carcinoma cell line Tca8113 as well as explore the underlying mechanism. GV230 (containing the PTEN gene) and empty vectors were transfected into Tca8113 cells. After stable transfection, the messenger RNA (mRNA) and protein levels of PTEN were validated using quantitative real-time PCR (qPCR) and Western blot analysis. The growth and cell cycle were analyzed using Cell Counting Kit-8 (CCK-8) and flow cytometry, respectively. The invasion ability was measured with a transwell assay. The effects of PTEN overexpression on EMT and Hedgehog signaling were assessed by comparing Tca8113-PTEN cells with control and negative control cell groups. We found that PTEN expression was significantly upregulated after transfection. Meanwhile, upregulated PTEN inhibited the proliferation and invasion of Tca8113 cells. In addition, we observed changes in the EMT- and Hedgehog-associated proteins. These data demonstrated that PTEN upregulation could reduce invasion by inhibiting the process of EMT in Tca8113 cells, which might be related to the Hedgehog signaling pathway.

  17. Bioprocess monitoring: minimizing sample matrix effects for total protein quantification with bicinchoninic acid assay.

    PubMed

    Reichelt, Wieland N; Waldschitz, Daniel; Herwig, Christoph; Neutsch, Lukas

    2016-09-01

    Determining total protein content is a routine operation in many laboratories. Despite substantial work on assay optimization interferences, the widely used bicinchoninic acid (BCA) assay remains widely recognized for its robustness. Especially in the field of bioprocess engineering the inaccuracy caused by interfering substances remains hardly predictable and not well understood. Since the introduction of the assay, sample pre-treatment by trichloroacetic acid (TCA) precipitation has been indicated as necessary and sufficient to minimize interferences. However, the sample matrix in cultivation media is not only highly complex but also dynamically changing over process time in terms of qualitative and quantitative composition. A significant misestimation of the total protein concentration of bioprocess samples is often observed when following standard work-up schemes such as TCA precipitation, indicating that this step alone is not an adequate means to avoid measurement bias. Here, we propose a modification of the BCA assay, which is less influenced by sample complexity. The dynamically changing sample matrix composition of bioprocessing samples impairs the conventional approach of compensating for interfering substances via a static offset. Hence, we evaluated the use of a correction factor based on an internal spike measurement for the respective samples. Using protein spikes, the accuracy of the BCA protein quantification could be improved fivefold, taking the BCA protein quantification to a level of accuracy comparable to other, more expensive methods. This will allow reducing expensive iterations in bioprocess development to due inaccurate total protein analytics.

  18. Production and functional evaluation of a protein concentrate from giant squid (Dosidicus gigas) by acid dissolution and isoelectric precipitation.

    PubMed

    Cortés-Ruiz, Juan A; Pacheco-Aguilar, Ramón; Elena Lugo-Sánchez, M; Gisela Carvallo-Ruiz, M; García-Sánchez, Guillermina

    2008-09-15

    A protein concentrate from giant squid (Dosidicus gigas) was produced under acidic conditions and its functional-technological capability evaluated in terms of its gel-forming ability, water holding capacity and colour attributes. Technological functionality of the concentrate was compared with that of squid muscle and a neutral concentrate. Protein-protein aggregates insoluble at high ionic strength (I=0.5M), were detected in the acidic concentrate as result of processing with no preclusion of its gel-forming ability during the sol-to-gel thermal transition. Even though washing under acidic condition promoted autolysis of the myosin heavy chain, the acidic concentrate displayed an outstanding ability to gel giving samples with a gel strength of 455 and 1160gcm at 75% and 90% compression respectively, and an AA folding test grade indicative of high gel strength, elasticity, and cohesiveness. The process proved to be a good alternative for obtaining a functional protein concentrate from giant squid muscle.

  19. Effects of acid precipitation on forest soils and watershed biogeochemistry in New England. A technical progress report

    SciTech Connect

    Cronan, C.S.

    1984-05-01

    The research described was initiated to address the need for improved understanding of the mechanistic linkages between forest growth and acidic depositing. A long-term whole-system investigation of forest responses to acidic deposition has been initiated. Nutrient depletion and availability in forest soils, plant nutrient status, trace metal cycling and toxicity, plant disease resistance, and overall plant productivity is emphasized. 48 references, 4 figures, 7 tables.

  20. Acid precipitation: Effects on fresh water ecosystems. (Latest citations from the Life Sciences Collection database). Published Search

    SciTech Connect

    Not Available

    1993-05-01

    The bibliography contains citations concerning the effects of acidification on fresh water ecosystems. Algae and diatom distribution, survival and reproduction rates of specific fish species under acid lake conditions, and tolerance to stress caused by acidic conditions in fresh water ecosystems are studied. Effects of water pH on trace metal toxicity to fresh water organisms are briefly considered. Control and reduction of acidification are excluded from this bibliography. (Contains 250 citations and includes a subject term index and title list.)

  1. LC-MS/MS analysis of Δ9-tetrahydrocannabinolic acid A in serum after protein precipitation using an in-house synthesized deuterated internal standard.

    PubMed

    Wohlfarth, Ariane; Roth, Nadine; Auwärter, Volker

    2012-06-01

    An assay based on liquid chromatography/tandem mass spectrometry is presented for the fast, precise and sensitive quantitation of Δ9-tetrahydrocannabinolic acid A (THCA) in serum. THCA is the biogenetic precursor of Δ9-tetrahydrocannabinol in cannabis and has aroused interest in the pharmacological and forensic field especially as a potential marker for recent cannabis use. After addition of deuterated THCA, synthesized from D(3)-THC as starting material, and protein precipitation, the analytes were separated using gradient elution on a Luna C18 column (150 × 2.0 mm × 5 µm) with 0.1% formic acid and acetonitrile/0.1% formic acid. Data acquisition was performed on a triple quadrupole linear ion trap mass spectrometer in multiple reaction monitoring mode with negative electrospray ionization. After optimization, the following sample preparation procedure was used: 200 μL serum was spiked with internal standard solution and methanol and then precipitated 'in fractions' with 500 μL ice-cold acetonitrile. After storage and centrifugation, the supernatant was evaporated and the residue redissolved in mobile phase. The assay was fully validated according to international guidelines including, for the first time, the assessment of matrix effects and stability experiments. Limit of detection was 0.1 ng/mL, and limit of quantification was 1.0 ng/mL. The method was found to be selective and proved to be linear over a range of 1.0 to 100 ng/mL using a 1/x weighted calibration model with regression coefficients >0.9996. Accuracy and precision data were within the required limits (RSD ≤ 8.6%, bias: 2.4 to 11.4%), extractive yield was greater than 84%. The analytes were stable in serum samples after three freeze/thaw cycles and storage at -20 °C for one month.

  2. Precipitation Recycling

    NASA Technical Reports Server (NTRS)

    Eltahir, Elfatih A. B.; Bras, Rafael L.

    1996-01-01

    The water cycle regulates and reflects natural variability in climate at the regional and global scales. Large-scale human activities that involve changes in land cover, such as tropical deforestation, are likely to modify climate through changes in the water cycle. In order to understand, and hopefully be able to predict, the extent of these potential global and regional changes, we need first to understand how the water cycle works. In the past, most of the research in hydrology focused on the land branch of the water cycle, with little attention given to the atmospheric branch. The study of precipitation recycling which is defined as the contribution of local evaporation to local precipitation, aims at understanding hydrologic processes in the atmospheric branch of the water cycle. Simply stated, any study on precipitation recycling is about how the atmospheric branch of the water cycle works, namely, what happens to water vapor molecules after they evaporate from the surface, and where will they precipitate?

  3. Speciation and precipitation of heavy metals in high-metal and high-acid mine waters from the Iberian Pyrite Belt (Portugal).

    PubMed

    Durães, Nuno; Bobos, Iuliu; da Silva, Eduardo Ferreira

    2017-02-01

    Acid mine waters (AMW) collected during high- and low-flow water conditions from the Lousal, Aljustrel, and São Domingos mining areas (Iberian Pyrite Belt) were physicochemically analyzed. Speciation calculation using PHREEQC code confirms the predominance of Me(n+) and Me-SO4 species in AMW samples. Higher concentration of sulfate species (Me-SO4) than free ion species (Me(n+), i.e., Al, Fe, and Pb) were found, whereas opposite behavior is verified for Mg, Cu, and Zn. A high mobility of Zn than Cu and Pb was identified. The sulfate species distribution shows that Fe(3+)-SO4(2-), SO4(2-), HSO4(-), Al-SO4, MgSO4(0), and CaSO4(0) are the dominant species, in agreement with the simple and mixed metal sulfates and oxy-hydroxysulphates precipitated from AMW. The saturation indices (SI) of melanterite and epsomite show a positive correlation with Cu and Zn concentrations in AMW, which are frequently retained in simple metal sulfates. Lead is well correlated with jarosite and alunite (at least in very acid conditions) than with simple metal sulfates. The Pb for K substitution in jarosite occurs as increasing Pb concentration in solution. Lead mobility is also controlled by anglesite precipitation (a fairly insoluble sulfate), where a positive correlation was ascertained when the SI approaches equilibrium. The zeta potential of AMW decreased as pH increased due to colloidal particles aggregation, where water species change from SO4(2-) to OH(-) species during acid to alkaline conditions, respectively. The AMW samples were supersaturated in schwertmannite and goethite, confirmed by the Me(n+)-SO4, Me(n+)-Fe-O-OH, or Me(n+)-S-O-Fe-O complexes identified by attenuated total reflectance infrared spectroscopy (ATR-IR). The ATR-IR spectrum of an AMW sample with pH 3.5 (sample L1) shows well-defined vibration plans attributed to SO4 tetrahedron bonded with Fe-(oxy)hydroxides and the Me(n+) sorbed by either SO4 or Fe-(oxy)hydroxides. For samples with lower pH values (pH ~ 2

  4. A new MicroTCA-based waveform digitizer for the Muon g-2 experiment

    SciTech Connect

    Sweigart, David A.

    2016-12-15

    We present the design of a new $\\mu$TCA-based waveform digitizer, which will be deployed in the Muon g-2 experiment at Fermilab and will allow our pileup identification requirement to be met. This digitizer features five independent channels, each with 12-bit, 800-MSPS digitization and a 1-Gbit memory buffer. The data storage and readout along with configuration are handled by six Xilinx Kintex-7 FPGAs. In addition, the digitizer is equipped with a mezzanine card for analog signal conditioning prior to digitization, further widening its range of possible applications. The performance results of this design are also presented, highlighting its $0.51 \\pm 0.13$ mV intrinsic noise level and $< 22$ ps intrinsic timing resolution between channels. We believe that its performance, together with its flexible design, could be of interest to future experiments in search of a cost-effective waveform digitizer.

  5. HSulf-1 deficiency dictates a metabolic reprograming of glycolysis and TCA cycle in ovarian cancer

    PubMed Central

    Mondal, Susmita; Roy, Debarshi; Camacho-Pereira, Juliana; Khurana, Ashwani; Chini, Eduardo; Yang, Lifeng; Baddour, Joelle; Stilles, Katherine; Padmabandu, Seth; Leung, Sam; Kalloger, Steve; Gilks, Blake; Lowe, Val; Dierks, Thomas; Hammond, Edward; Dredge, Keith; Nagrath, Deepak; Shridhar, Viji

    2015-01-01

    Warburg effect has emerged as a potential hallmark of many cancers. However, the molecular mechanisms that led to this metabolic state of aerobic glycolysis, particularly in ovarian cancer (OVCA) have not been completely elucidated. HSulf-1 predominantly functions by limiting the bioavailability of heparan binding growth factors and hence their downstream signaling. Here we report that HSulf-1, a known putative tumor suppressor, is a negative regulator of glycolysis. Silencing of HSulf-1 expression in OV202 cell line increased glucose uptake and lactate production by upregulating glycolytic genes such as Glut1, HKII, LDHA, as well as metabolites. Conversely, HSulf-1 overexpression in TOV21G cells resulted in the down regulation of glycolytic enzymes and reduced glycolytic phenotype, supporting the role of HSulf-1 loss in enhanced aerobic glycolysis. HSulf-1 deficiency mediated glycolytic enhancement also resulted in increased inhibitory phosphorylation of pyruvate dehydrogenase (PDH) thus blocking the entry of glucose flux into TCA cycle. Consistent with this, metabolomic and isotope tracer analysis showed reduced glucose flux into TCA cycle. Moreover, HSulf-1 loss is associated with lower oxygen consumption rate (OCR) and impaired mitochondrial function. Mechanistically, lack of HSulf-1 promotes c-Myc induction through HB-EGF-mediated p-ERK activation. Pharmacological inhibition of c-Myc reduced HB-EGF induced glycolytic enzymes implicating a major role of c-Myc in loss of HSulf-1 mediated altered glycolytic pathway in OVCA. Similarly, PG545 treatment, an agent that binds to heparan binding growth factors and sequesters growth factors away from their ligand also blocked HB-EGF signaling and reduced glucose uptake in vivo in HSulf-1 deficient cells. PMID:26378042

  6. DISSOLUTION OF LANTHANUM FLUORIDE PRECIPITATES

    DOEpatents

    Fries, B.A.

    1959-11-10

    A plutonium separatory ore concentration procedure involving the use of a fluoride type of carrier is presented. An improvement is given in the derivation step in the process for plutonium recovery by carrier precipitation of plutonium values from solution with a lanthanum fluoride carrier precipitate and subsequent derivation from the resulting plutonium bearing carrier precipitate of an aqueous acidic plutonium-containing solution. The carrier precipitate is contacted with a concentrated aqueous solution of potassium carbonate to effect dissolution therein of at least a part of the precipitate, including the plutonium values. Any remaining precipitate is separated from the resulting solution and dissolves in an aqueous solution containing at least 20% by weight of potassium carbonate. The reacting solutions are combined, and an alkali metal hydroxide added to a concentration of at least 2N to precipitate lanthanum hydroxide concomitantly carrying plutonium values.

  7. Acid precipitation and food quality: Inhibition of growth and survival in black ducks and mallards by dietary aluminum, calcium and phosphorus

    USGS Publications Warehouse

    Robbins, C.S.

    1990-01-01

    In areas impacted by acid precipitation, water chemistry of acidic ponds and streams often changes, resulting in increased mobilization of aluminum and decreased concentration of calcium carbonate. Aluminum binds with phosphorus and inhibits its uptake by organisms. Thus, invertebrate food organisms used by waterfowl may have inadequate Ca and P or elevated Al for normal growth and development. Acid rain and its effects may be one of the factors negatively impacting American black ducks (Anas rubripes) in eastern North America. One-day old mallards (A. platyrhynchos) and black ducks were placed on one of three Ca:P regimens: low:low (LL), normal:normal (NN), and low:high (LH) with each regimen divided further into three or four Al levels for 10 weeks. Forty-five % of the black ducks died on nine different diets whereas only 28% of the mallards died on three different diets. Mortality was significantly related to diet in both species. Growth rates for body weight, culmens, wings, and tarsi of both species on control diets exceeded those on many treatment diets but the differences were less apparent for mallards than for black ducks. Differences among treatments were due to both Ca:P and Al levels.

  8. CONCENTRATION OF Pu USING AN IODATE PRECIPITATE

    DOEpatents

    Fries, B.A.

    1960-02-23

    A method is given for separating plutonium from lanthanum in a lanthanum fluoride carrier precipitation process for the recovery of plutonium values from an aqueous solution. The carrier precipitation process includes the steps of forming a lanthanum fluoride precipi- . tate, thereby carrying plutonium out of solution, metathesizing the fluoride precipitate to a hydroxide precipitate, and then dissolving the hydroxide precipitate in nitric acid. In accordance with the invention, the nitric acid solution, which contains plutonium and lanthanum, is made 0.05 to 0.15 molar in potassium iodate. thereby precipitating plutonium as plutonous iodate and the plutonous iodate is separated from the lanthanum- containing supernatant solution.

  9. Extraction-less, rapid assay for the direct detection of 2,4,6-trichloroanisole (TCA) in cork samples.

    PubMed

    Apostolou, Theofylaktos; Pascual, Nuria; Marco, M-Pilar; Moschos, Anastassios; Petropoulos, Anastassios; Kaltsas, Grigoris; Kintzios, Spyridon

    2014-07-01

    2,4,6-trichloroanisole (TCA), the cork taint molecule, has been the target of several analytical approaches over the few past years. In spite of the development of highly efficient and sensitive tools for its detection, ranging from advanced chromatography to biosensor-based techniques, a practical breakthrough for routine cork screening purposes has not yet been realized, in part due to the requirement of a lengthy extraction of TCA in organic solvents, mostly 12% ethanol and the high detectability required. In the present report, we present a modification of a previously reported biosensor system based on the measurement of the electric response of cultured fibroblast cells membrane-engineered with the pAb78 TCA-specific antibody. Samples were prepared by macerating cork tissue and mixing it directly with the cellular biorecognition elements, without any intervening extraction process. By using this novel approach, we were able to detect TCA in just five minutes at extremely low concentrations (down to 0.2 ppt). The novel biosensor offers a number of practical benefits, including a very considerable reduction in the total assay time by one day, and a full portability, enabling its direct employment for on-site, high throughput screening of cork in the field and production facilities, without requiring any type of supporting infrastructure.

  10. (1)H nuclear magnetic resonance-based extracellular metabolomic analysis of multidrug resistant Tca8113 oral squamous carcinoma cells.

    PubMed

    Wang, Hui; Chen, Jiao; Feng, Yun; Zhou, Wenjie; Zhang, Jihua; Yu, Y U; Wang, Xiaoqian; Zhang, Ping

    2015-06-01

    A major obstacle of successful chemotherapy is the development of multidrug resistance (MDR) in the cancer cells, which is difficult to reverse. Metabolomic analysis, an emerging approach that has been increasingly applied in various fields, is able to reflect the unique chemical fingerprints of specific cellular processes in an organism. The assessment of such metabolite changes can be used to identify novel therapeutic biomarkers. In the present study, (1)H nuclear magnetic resonance (NMR) spectroscopy was used to analyze the extracellular metabolomic spectrum of the Tca8113 oral squamous carcinoma cell line, in which MDR was induced using the carboplatin (CBP) and pingyangmycin (PYM) chemotherapy drugs in vitro. The data were analyzed using the principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) methods. The results demonstrated that the extracellular metabolomic spectrum of metabolites such as glutamate, glycerophosphoethanol amine, α-Glucose and β-Glucose for the drug-induced Tca8113 cells was significantly different from the parental Tca8113 cell line. A number of biochemicals were also significantly different between the groups based on their NMR spectra, with drug-resistant cells presenting relatively higher levels of acetate and lower levels of lactate. In addition, a significantly higher peak was observed at δ 3.35 ppm in the spectrum of the PYM-induced Tca8113 cells. Therefore, (1)H NMR-based metabolomic analysis has a high potential for monitoring the formation of MDR during clinical tumor chemotherapy in the future.

  11. Acid-Sulfate Alteration at Gusev Crater and Across Mars: High-SiO2 Residues and Ferric Sulfate Precipitates

    NASA Technical Reports Server (NTRS)

    Morris, R. V.; Catalano, J. G.; Klingelhoefer, G.; Schroeder, C.; Gellert, R.; Clark, B. C.; Ming, D. W.; Yen, A. S.; Arvidson, R. E.; Cohen, B. A.; Fleischer, I.; McCoy, T. J.; Mittlefehldt, D. W.; Squyres, S. W.

    2017-01-01

    The Mars Exploration Rover Spirit ended its mission in Gusev crater on sol 2210 after it had become stuck in a deposit of fined-grained and sulfate rich soil with dust covered solar panels unfavorably pointed toward the sun. Final analysis of remaining data from Spirit's Moessbauer spectrometer (Fe redox and mineralogy) for sols 1529 through 2071 is now complete. We focus here on chemical (APXS) and MB data for targets having high-SiO2 or high-SO3 and process link the targets through mixing and geochemical modelling to an acid-sulfate system centered at Home Plate, which is considered to be a hydrovolcanic complex.

  12. Increased anaplerosis, TCA cycling, and oxidative phosphorylation in the liver of dairy cows with intensive body fat mobilization during early lactation.

    PubMed

    Schäff, Christine; Börner, Sabina; Hacke, Sandra; Kautzsch, Ulrike; Albrecht, Dirk; Hammon, Harald M; Röntgen, Monika; Kuhla, Björn

    2012-11-02

    The onset of milk production lets mammals experience an enormous energy and nutrient demand. To meet these requirements, high-yielding dairy cows mobilize body fat resulting in an augmented hepatic oxidative metabolism, which has been suggested to signal for depressing hunger after calving. To examine how the extent of fat mobilization influences hepatic oxidative metabolism and thus potentially feed intake, blood and liver samples of 19 Holstein cows were taken throughout the periparturient period. Retrospectively grouped according to high (H) and low (L) liver fat content, H cows showed higher fatty acid but lower amino acid plasma concentrations and lower feed intake than L cows. The hepatic phospho-AMPK/total AMP ratio was not different between groups but decreased after parturition. A 2-DE coupled MALDI-TOF-TOF analysis and qRT-PCR studies revealed H cows having lower expressions of major enzymes involved in mitochondrial β-oxidation, urea cycling, and the pentose phosphate pathway but higher expressions of enzymes participating in peroxisomal and endoplasmic fatty acid degradation, pyruvate and TCA cycling, amino acid catabolism, oxidative phosphorylation, and oxidative stress defense. These data indicate that increasing lipolysis leads to augmenting nutrient catabolism for anaplerosis and mitochondrial respiration, providing a molecular link between hepatic oxidative processes and feed intake.

  13. Real-time cell analysis and heat shock protein gene expression in the TcA Tribolium castaneum cell line in response to environmental stress conditions.

    PubMed

    García-Reina, Andrés; Rodríguez-García, María Juliana; Ramis, Guillermo; Galián, José

    2015-12-17

    The rust red flour beetle, Tribolium castaneum (Herbst, 1797) (Coleoptera: Tenebrionidae), is a pest of stored grain and one of the most studied insect model species. Some of the previous studies involved heat response studies in terms of survival and heat shock protein expression, which are regulated to protect other proteins against environmental stress conditions. In the present study, we characterize the impedance profile with the xCELLigence Real-Time Cell Analyzer and study the effect of increased temperature in cell growth and viability in the cell line BCIRL-TcA-CLG1 (TcA) of T. castaneum. This novel system measures cells behavior in real time and is applied for the first time to insect cells. Additionally, cells are exposed to heat shock, increased salinity, acidic pH and UV-A light with the aim of measuring the expression levels of Hsp27, Hsp68a and Hsp83 genes. Results show a high thermotolerance of TcA in terms of cell growth and viability. This result is likely related to gene expression results in which a significant up-regulation of all studied Hsp genes is observed after one hour of exposure to 40 ºC and UV light. All three genes show similar expression patterns, but Hsp27 seems to be the most affected. The results of this study validate the RTCA method and reveal the utility of insect cell lines, real-time analysis and gene expression studies to better understand the physiological response of insect cells, with potential applications in different fields of biology such as conservation biology and pest management. This article is protected by copyright. All rights reserved.

  14. Acid precipitation studies in Colorado and Wyoming: interim report of surveys of montane amphibians and water chemistry

    USGS Publications Warehouse

    Corn, Paul Stephen; Stolzenburg, William; Bury, R. Bruce

    1989-01-01

    Acid deposition may be detrimental or stressful to native populations of wildlife. Because many species of amphibians breed in shallow ponds created by spring rains or melting snow, they may be particularly vulnerable to the effects of acidification. From 1986 to 1988, we surveyed 105 locations in the central Rocky Mountains where amphibians had been recorded previously, and we found that two species of amphibians had experiences major losses. We found the northern leopard frog (Rana pipiens) at only 4 of 33 (12%) historically known localities, and the boreal toad (Bufo boreas) was present at 10 of 59 (17%) known localities. Three other species have not suffered region-wide declines. Tiger salamanders (Ambystoma tigrinum) and wood frogs (Rana sylvatica) were present at 45% and 69% of known localities respectively, and were observed at several localities were they had not been recorded previously. Chorus frogs (Pseudacris triseriata) suffered a catastrophic decline in population size in one population monitored since 1961, but regionally, this species was observed in 36 of 56 (64%) known localities and in another 19 localities where there were no previous records. Complete water chemistry was recorded for 41 localities, and pH was measured at 110 sites in total. Acid neutralizing capacity, pH, specific conductivity, and cation concentrations were negatively correlated with elevation. However, in mountain ponds and lakes, pH was rarely less than 6.0 during the amphibian breeding season. We tested the tolerance of embryos of the four species of frogs to low pH. The LC50 pH was 4.8 for chorus frogs, 4.4-4.7 for leopard frogs, 4.4-4.5 for boreal toads, and 4.2-4.3 for wood frogs. Survival of wood frog embryos declined when exposed to aluminum concentrations of 100 µg/L or greater, but boreal toad embryos survived exposure to aluminum concentrations of 400 µg/L. Acid deposition does not appear to be a major factor in the decline of leopard frogs and boreal toads

  15. Growth response of four species of Eastern hardwood tree seedlings exposed to ozone, acidic precipitation, and sulfur dioxide. [Prunus serotina, Acer rubrum, Quercus rubra, Liriodendron tulipifera

    SciTech Connect

    Davis, D.D. Skelly, J.M. )

    1992-03-01

    In 1987 a study was conducted in controlled environment chambers to determine the foliar sensitivity of tree seedlings of eight species to ozone and acidic precipitation, and to determine the influence of leaf position on symptom severity. Jensen and Dochinger conducted concurrent similar studies in Continuously Stirred Tank Reactor (CSTR) chambers with ten species of forest trees. Based on the results of these initial studies, four species representing a range in foliar sensitivity to ozone were chosen: black cherry (Prunus serotina Ehrh.), red maple (Acer rubrum L.), northern red oak (Quercus rubra L.) and yellow-poplar (Liriodendron tulipifera L.). These species were also chosen because of their ecological and/or commercial importance in Pennsylvania. Seedlings were exposed in growth chambers simulated acid rain. In addition acute exposures to sulfur dioxide were conducted in a regime based on unpublished monitoring data collected near coal-fired power plants. The objective of this study was to determine if the pollutant treatments influenced the growth and productivity of seedlings of these four species. This information will help researchers and foresters understand the role of air pollution in productivity of eastern forests.

  16. Precipitation Matters

    ERIC Educational Resources Information Center

    McDuffie, Thomas

    2007-01-01

    Although weather, including its role in the water cycle, is included in most elementary science programs, any further examination of raindrops and snowflakes is rare. Together rain and snow make up most of the precipitation that replenishes Earth's life-sustaining fresh water supply. When viewed individually, raindrops and snowflakes are quite…

  17. Developmental and anatomical changes in leaves of yellow birch and red kidney bean exposed to simulated acid precipitation

    SciTech Connect

    Paparozzi, E.T.; Tukey, H.B. Jr.

    1983-01-01

    Leaves of Betula alleghaniensis Britt. (yellow birch) and Phaseolus vulgaris L cv. Red Kidney (bean) were examined microscopically during development and after exposure to simulated rain of pH 5.5, 4.3, 3.2, and 2.8. Yellow birch leaves attained maximal leaf area, midvein length, and cuticle thickness at 21 days. Trichomes were either long, unicellular, or multicellular with caplike head and stalk. Epicuticular wax was a bumpy and amorphous layer. The 2nd trifoliolate leaf of red kidney bean attained maximal leaf area, midvein length, and cuticle thickness when the 3rd trifoliolate leaf was expanding. Trichomes present were long, with a unicellular head and a multicellular base; long, unicellular, and terminally hooked; and small and multicellular. Epicuticular wax was present as small irregular flakes. After 2 days of pH 2.8 and 4 days of pH 3.2 simulated acid rain, round yellow and small tan lesions appeared on birch and bean leaves, respectively. Most injury occurred on or between small veins. Most trichome types were uninjured. Lesions formed as a result of collapsed epidermal and highly plasmolyzed palisade cells. The cuticle was still present over injured epidermal cells and epicuticular waxes were unchanged. There was not statistical difference in mean cuticle thickness due to pH of simulated rain. 25 references, 10 figures, 4 tables.

  18. Co-precipitation of asiatic acid and poly( l-lactide) using rapid expansion of subcritical solutions into liquid solvents

    NASA Astrophysics Data System (ADS)

    Sane, Amporn; Limtrakul, Jumras

    2011-09-01

    Poly( l-lactide) (PLLA) nanoparticles loaded with asiatic acid (AA) were successfully produced by rapid expansion of a subcritical solution into an aqueous receiving solution containing a dispersing agent. A mixture of carbon dioxide (CO2) and ethanol (EtOH) with a weight ratio of 1:1 was used as the solvent for AA and PLLA. Two surfactants, Pluronic F127 and sodium dodecyl sulfate were employed. The former was found to be more effective for stabilizing AA-loaded PLLA nanoparticles, as a rapid expansion into a 0.1 wt% Pluronic F127 solution produced a stable nanosuspension consisting mainly of well-dispersed, individual nanoparticles. The effects of rapid expansion-processing conditions—AA to PLLA weight ratio and pre-expansion temperature (Tpre)—on the size and morphology of composite nanoparticles, and the loading capacity and entrapment efficiency of AA in PLLA nanoparticles, were systematically investigated. It was found that AA-loaded PLLA nanoparticles with a size range of 30-100 nm were consistently fabricated by rapid expansion at Tpre of 70-100 °C and AA to PLLA weight ratios of 1:2 and 1:4, and with a constant pre-expansion pressure of 330 bar. The Tpre and AA to PLLA weight ratio had no significant effects on the size of the nanoparticles. The AA to PLLA weight ratio is a controlling parameter for both the loading capacity and the entrapment efficiency of AA in PLLA nanoparticles. The loading capacity and entrapment efficiency increased from 8-11 to 16-21 wt%, and 38-57 to 50-62 wt%, respectively, when the AA to PLLA weight ratio changed from 1:4 to 1:2. However, increasing the Tpre from 70 to 100 °C decreased both the loading capacity and entrapment efficiency of AA in PLLA nanoparticles by 20-30%.

  19. Effects of acidic deposition on the erosion of carbonate stone - experimental results from the U.S. National Acid Precipitation Assessment Program (NAPAP)

    USGS Publications Warehouse

    Baedecker, P.A.; Reddy, M.M.; Reimann, K.J.; Sciammarella, C.A.

    1992-01-01

    One of the goals of NAPAP-sponsored research on the effects of acidic deposition on carbonate stone has been to quantify the incremental effects of wet and dry deposition of hydrogen ion, sulfur dioxide and nitrogen oxides on stone erosion. Test briquettes and slabs of freshly quarried Indiana limestone and Vermont marble have been exposed to ambient environmental conditions in a long-term exposure program. Physical measurements of the recession of test stones exposed to ambient conditions at an angle of 30?? to horizontal at the five NAPAP materials exposure sites range from ~15 to ~30?? ??m yr-1 for marble, and from ~25 to ~45 ??m yr -1 for limestone, and are approximately double the recession estimates based on the observed calcium content of run-off solutions from test slabs. The difference between the physical and chemical recession measurements is attributed to the loss of mineral grains from the stone surfaces that are not measured in the run-off experiments. The erosion due to grain loss does not appear to be influenced by rainfall acidity, however, preliminary evidence suggests that grain loss may be influenced by dry deposition of sulfur dioxide between rainfall events. Chemical analyses of the run-off solutions and associated rainfall blanks suggest that ~30% of erosion by dissolution can be attributed to the wet deposition of hydrogen ion and the dry deposition of sulfur dioxide and nitric acid between rain events. The remaining ~70% of erosion by dissolution is accounted for by the solubility of carbonate stone in rain that is in equilibrium with atmospheric carbon dioxide ('clean rain'). These results are for marble and limestone slabs exposed at an angle of 30?? from horizontal. The relative contribution of sulfur dioxide to chemical erosion is significantly enhanced for stone slabs having an inclination of 60?? or 85??. The dry deposition of alkaline particulate material has a mitigating effect at the two urban field exposure sites at Washington, DC

  20. Targeted toxicological screening for acidic, neutral and basic substances in postmortem and antemortem whole blood using simple protein precipitation and UPLC-HR-TOF-MS.

    PubMed

    Telving, Rasmus; Hasselstrøm, Jørgen Bo; Andreasen, Mette Findal

    2016-09-01

    A broad targeted screening method based on broadband collision-induced dissociation (bbCID) ultra-performance liquid chromatography high-resolution time-of-flight mass spectrometry (UPLC-HR-TOF-MS) was developed and evaluated for toxicological screening of whole blood samples. The acidic, neutral and basic substances covered by the method were identified in postmortem and antemortem whole blood samples from forensic autopsy cases, clinical forensic cases and driving under the influence of drugs (DUID) cases by a reverse target database search. The screening method covered 467 substances. Validation was performed on spiked whole blood samples and authentic postmortem and antemortem whole blood samples. For most of the basic drugs, the established cut-off limits were very low, ranging from 0.25ng/g to 50ng/g. The established cut-off limits for most neutral and acidic drugs, were in the range from 50ng/g to 500ng/g. Sample preparation was performed using simple protein precipitation of 300μL of whole blood with acetonitrile and methanol. Ten microliters of the reconstituted extract were injected and separated within a 13.5min UPLC gradient reverse-phase run. Positive electrospray ionization (ESI) was used to generate the ions in the m/z range of 50-1000. Fragment ions were generated by bbCID. Identification was based on retention time, accurate mass, fragment ion(s) and isotopic pattern. A very sensitive broad toxicological screening method using positive electrospray ionization UPLC-HR-TOF-MS was achieved in one injection. This method covered basic substances, substances traditionally analyzed in negative ESI (e.g., salicylic acid), small highly polar substances such as beta- and gamma-hydroxybutyric acid (BHB and GHB, respectively) and highly non-polar substances such as amiodarone. The new method was shown to combine high sensitivity with a very broad scope that has not previously been reported in toxicological whole blood screening when using only one injection.

  1. Global transcription analysis of Krebs tricarboxylic acid cycle mutants reveals an alternating pattern of gene expression and effects on hypoxic and oxidative genes.

    PubMed

    McCammon, Mark T; Epstein, Charles B; Przybyla-Zawislak, Beata; McAlister-Henn, Lee; Butow, Ronald A

    2003-03-01

    To understand the many roles of the Krebs tricarboxylic acid (TCA) cycle in cell function, we used DNA microarrays to examine gene expression in response to TCA cycle dysfunction. mRNA was analyzed from yeast strains harboring defects in each of 15 genes that encode subunits of the eight TCA cycle enzymes. The expression of >400 genes changed at least threefold in response to TCA cycle dysfunction. Many genes displayed a common response to TCA cycle dysfunction indicative of a shift away from oxidative metabolism. Another set of genes displayed a pairwise, alternating pattern of expression in response to contiguous TCA cycle enzyme defects: expression was elevated in aconitase and isocitrate dehydrogenase mutants, diminished in alpha-ketoglutarate dehydrogenase and succinyl-CoA ligase mutants, elevated again in succinate dehydrogenase and fumarase mutants, and diminished again in malate dehydrogenase and citrate synthase mutants. This pattern correlated with previously defined TCA cycle growth-enhancing mutations and suggested a novel metabolic signaling pathway monitoring TCA cycle function. Expression of hypoxic/anaerobic genes was elevated in alpha-ketoglutarate dehydrogenase mutants, whereas expression of oxidative genes was diminished, consistent with a heme signaling defect caused by inadequate levels of the heme precursor, succinyl-CoA. These studies have revealed extensive responses to changes in TCA cycle function and have uncovered new and unexpected metabolic networks that are wired into the TCA cycle.

  2. Thiomonas sp. CB2 is able to degrade urea and promote toxic metal precipitation in acid mine drainage waters supplemented with urea

    PubMed Central

    Farasin, Julien; Andres, Jérémy; Casiot, Corinne; Barbe, Valérie; Faerber, Jacques; Halter, David; Heintz, Dimitri; Koechler, Sandrine; Lièvremont, Didier; Lugan, Raphael; Marchal, Marie; Plewniak, Frédéric; Seby, Fabienne; Bertin, Philippe N.; Arsène-Ploetze, Florence

    2015-01-01

    The acid mine drainage (AMD) in Carnoulès (France) is characterized by the presence of toxic metals such as arsenic. Several bacterial strains belonging to the Thiomonas genus, which were isolated from this AMD, are able to withstand these conditions. Their genomes carry several genomic islands (GEIs), which are known to be potentially advantageous in some particular ecological niches. This study focused on the role of the “urea island” present in the Thiomonas CB2 strain, which carry the genes involved in urea degradation processes. First, genomic comparisons showed that the genome of Thiomonas sp. CB2, which is able to degrade urea, contains a urea genomic island which is incomplete in the genome of other strains showing no urease activity. The urease activity of Thiomonas sp. CB2 enabled this bacterium to maintain a neutral pH in cell cultures in vitro and prevented the occurrence of cell death during the growth of the bacterium in a chemically defined medium. In AMD water supplemented with urea, the degradation of urea promotes iron, aluminum and arsenic precipitation. Our data show that ureC was expressed in situ, which suggests that the ability to degrade urea may be expressed in some Thiomonas strains in AMD, and that this urease activity may contribute to their survival in contaminated environments. PMID:26441922

  3. Acid precipitation and food quality: Effects of dietary Al, Ca and P on bone and liver characteristics in American black ducks and mallards

    USGS Publications Warehouse

    Sparling, D.W.

    1991-01-01

    American black ducks (Anas rubripes) and mallards (A. platyrhynchos) were fed diets varying in concentrations of aluminum (Al). calcium (Ca), and phosphorus (P) for 10 weeks to identify toxic effects of Al under conditions representative of areas with acid precipitation. Femur and liver tissues were analyzed for Al. Ca, and P concentrations and structural characteristics. At two weeks of age, both species demonstrated pronounced differences in femur Al and P concentrations and femur mass from dietary Al and interaction between Ca:P regimen and Al:Low Ca:Low P enhanced Al storage and decreased P and mass in femurs. Femur Ca was lowest in the Low Ca:Low P regimen but was not affected by dietary Al. At 10 weeks, femur and liver Al continued to vary with dietary Al. Elevated Al and reduced Ca lowered modulus of elasticity. Femur P increased with elevated dietary P in black ducks. Elevated dietary P negated some of the effects of dietary A! on femur mass in black ducks. Reduced Ca concentrations weakened bones of both species and lowered both Ca and P. An array of clinical signs including lameness, discoloration of the upper mandible, complete and greenstick fractures, and death were responses to elevated Al and Ca:P regimen. Black ducks seemed to display these signs over a wider range of diets than mallards. Diets of 1,000 mg/kg Al had toxic effects on both species, particularly when combined with diets low in Ca and P.

  4. Convenient and rapid determination of cimetidine in human plasma using perchloric acid-mediated plasma protein precipitation and high-performance liquid chromatography.

    PubMed

    Jantratid, Ekarat; Prakongpan, Sompol; Foley, Joe P; Dressman, Jennifer B

    2007-09-01

    This study demonstrates the analysis of cimetidine in human plasma with HPLC using a simplified sample preparation by protein precipitation with perchloric acid. Plasma cimetidine concentration was determined by plotting peak height ratio of cimetidine to ranitidine (internal standard, IS) against cimetidine concentrations in plasma. The cimetidine and ranitidine peaks were completely separated and no interference from plasma was observed. The lower limit of quantification (LLOQ) of the method was established at 0.1 microg/mL with a precision of 4.3% and a relative error of 1.9%. The average analytical recovery was >90% over the range of cimetidine concentrations (0.1-15.0 microg/mL). The linearity of calibration curve was excellent (r(2) > 0.999). The within- and between-day precision and accuracy, expressed as the coefficients of variation and relative error, were found to be less than 5%. Compared with previously reported methods, the analytical technique for cimetidine determination in human plasma presented here demonstrates comparable accuracy and precision, an acceptable analysis time, shorter and simpler sample preparation, and a reduced need for complicated equipment. The method presented here is simple and rapid, and the precision and sensitivity are appropriate for the determination of cimetidine in plasma in pharmacokinetic studies.

  5. TCA1, a single nuclear-encoded translational activator specific for petA mRNA in Chlamydomonas reinhardtii chloroplast.

    PubMed Central

    Wostrikoff, K; Choquet, Y; Wollman, F A; Girard-Bascou, J

    2001-01-01

    We isolated seven allelic nuclear mutants of Chlamydomonas reinhardtii specifically blocked in the translation of cytochrome f, a major chloroplast-encoded subunit of the photosynthetic electron transport chain encoded by the petA gene. We recovered one chloroplast suppressor in which the coding region of petA was now expressed under the control of a duplicated 5' untranslated region from another open reading frame of presently unknown function. Since we also recovered 14 nuclear intragenic suppressors, we ended up with 21 alleles of a single nuclear gene we called TCA1 for translation of cytochrome b(6)f complex petA mRNA. The high number of TCA1 alleles, together with the absence of genetic evidence for other nuclear loci controlling translation of the chloroplast petA gene, strongly suggests that TCA1 is the only trans-acting factor. We studied the assembly-dependent regulation of cytochrome f translation--known as the CES process--in TCA1-mutated contexts. In the presence of a leaky tca1 allele, we observed that the regulation of cytochrome f translation was now exerted within the limits of the restricted translational activation conferred by the altered version of TCA1 as predicted if TCA1 was the ternary effector involved in the CES process. PMID:11560891

  6. Power Effects on High Lift, Stability and Control Characteristics of the TCA Model Tested in the LaRC 14 x 22 Ft Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Glessner, Paul T.

    1999-01-01

    The TCA-2 wind-tunnel test was the second in a series of planned tests utilizing the 5% Technology Concept Airplane (TCA) model. Each of the tests was planned to utilize the unique capabilities of the NASA Langley 14'x22' and the NASA Ames 12' test facilities, in order to assess specific aspects of the high lift and stability and control characteristics of the TCA configuration. However, shortly after the completion of the TCA-1 test, an early projection of the Technology Configuration (TC) identified the need for several significant changes to the baseline TCA configuration. These changes were necessary in order to meet more stringent noise certification levels, as well as, to provide a means to control dynamic structural modes. The projected changes included a change to the outboard wing (increased aspect ratio and lower sweep) and a reconfiguration of the longitudinal control surfaces to include a medium size canard and a reduced horizontal tail. The impact of these proposed changes did not affect the TCA-2 test, because it was specifically planned to address power effects on the empennage and a smaller horizontal tail was in the plan to be tested. However, the focus of future tests was reevaluated and the emphasis was shifted away from assessment of TCA specific configurations to a more general assessment of configurations that encompass the projected design space for the TC.

  7. A general method of protein purification for recombinant unstructured non-acidic proteins.

    PubMed

    Campos, Francisco; Guillén, Gabriel; Reyes, José L; Covarrubias, Alejandra A

    2011-11-01

    Typical late embryogenesis abundant (LEA) proteins accumulate in response to water deficit imposed by the environment or by plant developmental programs. Because of their physicochemical properties, they can be considered as hydrophilins and as a paradigm of intrinsically unstructured proteins (IUPs) in plants. To study their biophysical and biochemical characteristics large quantities of highly purified protein are required. In this work, we report a fast and simple purification method for non-acidic recombinant LEA proteins that does not need the addition of tags and that preserves their in vitro protective activity. The method is based on the enrichment of the protein of interest by boiling the bacterial protein extract, followed by a differential precipitation with trichloroacetic acid (TCA). Using this procedure we have obtained highly pure recombinant LEA proteins of groups 1, 3, and 4 and one recombinant bacterial hydrophilin. This protocol will facilitate the purification of this type of IUPs, and could be particularly useful in proteomic projects/analyses.

  8. The Aspergillus nidulans acuL gene encodes a mitochondrial carrier required for the utilization of carbon sources that are metabolized via the TCA cycle.

    PubMed

    Flipphi, Michel; Oestreicher, Nathalie; Nicolas, Valérie; Guitton, Audrey; Vélot, Christian

    2014-07-01

    In Aspergillus nidulans, the utilization of acetate as sole carbon source requires several genes (acu). Most of them are also required for the utilization of fatty acids. This is the case for acuD and acuE, which encode the two glyoxylate cycle-specific enzymes, isocitrate lyase and malate synthase, respectively, but also for acuL that we have identified as AN7287, and characterized in this study. Deletion of acuL resulted in the same phenotype as the original acuL217 mutant. acuL encodes a 322-amino acid protein which displays all the structural features of a mitochondrial membrane carrier, and shares 60% identity with the Saccharomyces cerevisiae succinate/fumarate mitochondrial antiporter Sfc1p (also named Acr1p). Consistently, the AcuL protein was shown to localize in mitochondria, and partial cross-complementation was observed between the S. cerevisiae and A. nidulans homologues. Extensive phenotypic characterization suggested that the acuL gene is involved in the utilization of carbon sources that are catabolized via the TCA cycle, and therefore require gluconeogenesis. In addition, acuL proves to be co-regulated with acuD and acuE. Overall, our data suggest that AcuL could link the glyoxylate cycle to gluconeogenesis by exchanging cytoplasmic succinate for mitochondrial fumarate.

  9. Parametric Flutter Analysis of the TCA Configuration and Recommendation for FFM Design and Scaling

    NASA Technical Reports Server (NTRS)

    Baker, Myles; Lenkey, Peter

    1997-01-01

    The current HSR Aeroelasticity plan to design, build, and test a full span, free flying transonic flutter model in the TDT has many technical obstacles that must be overcome for a successful program. One technical obstacle is the determination of a suitable configuration and point in the sky to use in setting the scaling point for the ASE models program. Determining this configuration and point in the sky requires balancing several conflicting requirements, including model buildability, tunnel test safety, and the ability of the model to represent the flutter mechanisms of interest. As will be discussed in detail in subsequent sections, the current TCA design exhibits several flutter mechanisms of interest. It has been decided that the ASE models program will focus on the low frequency symmetric flutter mechanism, and will make no attempt to investigate high frequency flutter mechanisms. There are several reasons for this choice. First, it is believed that the high frequency flutter mechanisms are similar in nature to classical wing bending/torsion flutter, and therefore there is more confidence that this mechanism can be predicted using current techniques. The low frequency mode, on the other hand, is a highly coupled mechanism involving wing, body, tail, and engine motion which may be very difficult to predict. Second, the high frequency flutter modes result in very small weight penalties (several hundred pounds), while suppression of the low frequency mechanism inside the flight envelope causes thousands of pounds to be added to the structure. In order to successfully test the low frequency flutter mode of interest, a suitable starting configuration and point in the sky must be identified. The configuration and point in the sky must result in a wind tunnel model that (1) represents the low-frequency wing/body/engine/empennage flutter mechanisms that are unique to HSCT configurations, (2) flutters at an acceptably low frequency in the tunnel, (3) flutters at an

  10. Combined effects of CO2 enrichment and elevated growth temperatures on metabolites in soybean leaflets: evidence for dynamic changes of TCA cycle intermediates.

    PubMed

    Sicher, Richard

    2013-08-01

    Soybean (Glycine max [Merr.] L.) was grown in indoor chambers with ambient (38 Pa) and elevated (70 Pa) CO2 and day/night temperature treatments of 28/20, 32/24 and 36/28 °C. We hypothesized that CO2 enrichment would mitigate the deleterious effects of elevated growth temperatures on metabolites in soybean leaflets. Net CO2 assimilation rates increased incrementally with growth temperature and were enhanced up to 24 % on average by CO2 enrichment. Stomatal conductance about doubled from the lowest to highest temperature but this was partially reversed by CO2 enrichment. Metabolites were measured thrice daily and 19 and 28 of 43 total leaf metabolites were altered by the 32/24 and 36/28 °C temperature treatments, respectively, in both CO2 treatments. Polyols, raffinose and GABA increased and 23 nonstructural carbohydrates, organic acids and amino acids decreased when the temperature was increased from 28 to 36 °C under ambient CO2. Citrate, aconitate and 2-oxoglutarate decreased over 90 % in the 36/28 °C compared to the 28/20 °C temperature treatment. Temperature-dependent changes of sugars, organic acids and all but three amino acids were almost completely eliminated by CO2 enrichment. The above findings suggested that specific TCA cycle intermediates were highly depleted by heat stress under ambient CO2. Mitigating effects of CO2 enrichment on soybean leaflet metabolites were attributed to altered rates of photosynthesis, photorespiration, dark respiration, the anaplerotic pathway and to possible changes of gene expression.

  11. Photocatalytic removal of 2,4-dichlorophenoxyacetic acid herbicide on copper oxide/titanium dioxide prepared by co-precipitation method

    NASA Astrophysics Data System (ADS)

    Lee, Shu Chin; Hasan, Norhasnita; Lintang, Hendrik O.; Shamsuddin, Mustaffa; Yuliati, Leny

    2016-02-01

    In this work, suppression of the charge recombination on the titanium dioxide (TiO2) was reported by the addition of copper oxide (CuO), which led to a higher activity of TiO2 for removal of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide. A series of CuO/TiO2 with CuO loadings of 0.1-1 wt% was prepared through a co-precipitation method. X-ray diffraction patterns revealed that the presence of CuO could not be detected as the low loading amount of CuO might have good dispersion on the surface of TiO2. Diffuse reflectance UV-visible spectra suggested that low loading amount of CuO did not influence the optical property of TiO2. Fluorescence spectroscopy revealed that TiO2 possessed a dominant emission peak of 407 nm at an excitation wavelength of 218 nm. The increasing loading amount of CuO decreased the emission intensity of TiO2, suggesting the successful reduction of charge recombination. After irradiation under UV light for 1 h, CuO(0.1 wt%)/TiO2 gave the highest percentage removal of the herbicide among the samples. The optimum loading amount of CuOmight improve the charge separation and reduce the electron-hole recombination on TiO2 without blocking the active sites, thus leading to the improved photocatalytic activity. This work showed that CuO/TiO2 is a potential photocatalyst for environmental remediation.

  12. Selective recovery of dissolved Fe, Al, Cu, and Zn in acid mine drainage based on modeling to predict precipitation pH.

    PubMed

    Park, Sang-Min; Yoo, Jong-Chan; Ji, Sang-Woo; Yang, Jung-Seok; Baek, Kitae

    2015-02-01

    Mining activities have caused serious environmental problems including acid mine drainage (AMD), the dispersion of mine tailings and dust, and extensive mine waste. In particular, AMD contaminates soil and water downstream of mines and generally contains mainly valuable metals such as Cu, Zn, and Ni as well as Fe and Al. In this study, we investigated the selective recovery of Fe, Al, Cu, Zn, and Ni from AMD. First, the speciation of Fe, Al, Cu, Zn, and Ni as a function of the equilibrium solution pH was simulated by Visual MINTEQ. Based on the simulation results, the predicted pHs for the selective precipitation of Fe, Al, Cu, and Zn/Ni were determined. And recovery yield of metals using simulation is over 99 %. Experiments using artificial AMD based on the simulation results confirmed the selective recovery of Fe, Al, Cu, and Zn/Ni, and the recovery yields of Fe/Al/Cu/Zn and Fe/Al/Cu/Ni mixtures using Na2CO3 were 99.6/86.8/71.9/77.0 % and 99.2/85.7/73.3/86.1 %, respectively. After then, the simulation results were applied to an actual AMD for the selective recovery of metals, and the recovery yields of Fe, Al, Cu, and Zn using NaOH were 97.2, 74.9, 66.9, and 89.7 %, respectively. Based on the results, it was concluded that selective recovery of dissolved metals from AMD is possible by adjusting the solution pH using NaOH or Na2CO3 as neutralizing agents.

  13. Chloroacetic acids in European soils and vegetation.

    PubMed

    Peters, Ruud J B

    2003-04-01

    Trichloroacetic acid (TCA) and dichloroacetic acid (DCA) are possible minor atmospheric degradation products of perchloroethylene and trichloroethylene, respectively. These acids may be wet- or dry-deposited from the atmosphere to land surfaces and hence possibly affect plant growth. However, the existing database on TCA levels in soil is limited to a few studies carried out in the late 1980's and the early to mid-1990's and it was concluded that there is a need for further measurements of concentrations of TCA and DCA in soils. In this study soil samples from 10 locations in 5 European countries, as well as vegetation samples, and a limited number of rainwater and air samples were collected and analysed for DCA and TCA to determine the concentrations of these compounds. An isotope dilution method using GC-MS was used for the determination of these acids in the samples. The method was briefly validated and the performance characteristics are presented. The results of the analysis of the soil samples show that the DCA and TCA concentrations in soil from different sites in Europe are more or less comparable, with the exception of Germany, especially Freudenstadt, where significantly higher TCA concentrations (up to 12 microg kg(-1) dw) were found. The average DCA and TCA concentrations in soil in this study were 0.25 +/- 0.12 and 0.64 +/- 1.40 microg kg(-1) dw, respectively. Generally, the concentration in soils from forest areas are about twice those from open-land areas. The DCA and TCA concentrations in vegetation samples ranged from 2.1 to 73 microg kg(-1) dw for DCA and from 4.7 to 17 microg kg(-1) dw for TCA. Thus, the concentrations in vegetation samples are 10-20 times higher than the soil concentrations. DCA and TCA concentrations in wet deposition samples and air samples collected in The Netherlands were 0.14 and 0.15 microg l(-1) for wet deposition samples and <0.5 and 0.7 ng m(-3) for air samples respectively. For these samples taken in The Netherlands

  14. Exposure of ELF-EMF and RF-EMF Increase the Rate of Glucose Transport and TCA Cycle in Budding Yeast

    PubMed Central

    Lin, Kang-Wei; Yang, Chuan-Jun; Lian, Hui-Yong; Cai, Peng

    2016-01-01

    In this study, we investigated the transcriptional response to 50 Hz extremely low frequency electromagnetic field (ELF-EMF) and 2.0 GHz radio frequency electromagnetic field (RF-EMF) exposure by Illumina sequencing technology using budding yeast as the model organism. The transcription levels of 28 genes were upregulated and those of four genes were downregulated under ELF-EMF exposure, while the transcription levels of 29 genes were upregulated and those of 24 genes were downregulated under RF-EMF exposure. After validation by reverse transcription quantitative polymerase chain reaction (RT-qPCR), a concordant direction of change both in differential gene expression (DGE) and RT-qPCR was demonstrated for nine genes under ELF-EMF exposure and for 10 genes under RF-EMF exposure. The RT-qPCR results revealed that ELF-EMF and RF-EMF exposure can upregulate the expression of genes involved in glucose transportation and the tricarboxylic acid (TCA) cycle, but not the glycolysis pathway. Energy metabolism is closely related with the cell response to environmental stress including EMF exposure. Our findings may throw light on the mechanism underlying the biological effects of EMF. PMID:27630630

  15. Exposure of ELF-EMF and RF-EMF Increase the Rate of Glucose Transport and TCA Cycle in Budding Yeast.

    PubMed

    Lin, Kang-Wei; Yang, Chuan-Jun; Lian, Hui-Yong; Cai, Peng

    2016-01-01

    In this study, we investigated the transcriptional response to 50 Hz extremely low frequency electromagnetic field (ELF-EMF) and 2.0 GHz radio frequency electromagnetic field (RF-EMF) exposure by Illumina sequencing technology using budding yeast as the model organism. The transcription levels of 28 genes were upregulated and those of four genes were downregulated under ELF-EMF exposure, while the transcription levels of 29 genes were upregulated and those of 24 genes were downregulated under RF-EMF exposure. After validation by reverse transcription quantitative polymerase chain reaction (RT-qPCR), a concordant direction of change both in differential gene expression (DGE) and RT-qPCR was demonstrated for nine genes under ELF-EMF exposure and for 10 genes under RF-EMF exposure. The RT-qPCR results revealed that ELF-EMF and RF-EMF exposure can upregulate the expression of genes involved in glucose transportation and the tricarboxylic acid (TCA) cycle, but not the glycolysis pathway. Energy metabolism is closely related with the cell response to environmental stress including EMF exposure. Our findings may throw light on the mechanism underlying the biological effects of EMF.

  16. DISSOLUTION OF PLUTONIUM CONTAINING CARRIER PRECIPITATE BY CARBONATE METATHESIS AND SEPARATION OF SULFIDE IMPURITIES THEREFROM BY SULFIDE PRECIPITATION

    DOEpatents

    Duffield, R.B.

    1959-07-14

    A process is described for recovering plutonium from foreign products wherein a carrier precipitate of lanthanum fluoride containing plutonium is obtained and includes the steps of dissolving the carrier precipitate in an alkali metal carbonate solution, adding a soluble sulfide, separating the sulfide precipitate, adding an alkali metal hydroxide, separating the resulting precipitate, washing, and dissolving in a strong acid.

  17. Icotinib inhibits the invasion of Tca8113 cells via downregulation of nuclear factor κB-mediated matrix metalloproteinase expression

    PubMed Central

    YANG, CAILING; YAN, JIANGUO; YUAN, GUOYAN; ZHANG, YINGHUA; LU, DERONG; REN, MINGXIN; CUI, WEIGANG

    2014-01-01

    Icotinib is an epidermal growth factor receptor tyrosine kinase inhibitor, which has been revealed to inhibit proliferation in tumor cells. However, the effect of icotinib on cancer cell metastasis remains to be explained. This study examines the effect of icotinib on the migration and invasion of squamous cells of tongue carcinoma (Tca8113 cells) in vitro. The results of the Boyden chamber invasion assay demonstrated that icotinib reduced cell invasion, suppressed the protein levels of matrix metalloproteinases (MMPs), MMP-2 and MMP-9, and increased the expression of tissue inhibitor of metalloproteinase-1. In addition, icotinib was found to significantly decrease the protein levels of nuclear factor κB (NF-κB) p65, which suggested that icotinib inhibits NF-κB activity. Furthermore, treatment with the NF-κB inhibitor, pyrrolidine dithiocarbamate, suppressed cell invasion and MMP-2 expression. These results suggested that icotinib inhibits the invasion of Tca8113 cells by downregulating MMP via the inactivation of the NF-κB signaling pathways. PMID:25120710

  18. The Role of TCA Cycle Anaplerosis in Ketosis and Fatty Liver in Periparturient Dairy Cows

    PubMed Central

    White, Heather M.

    2015-01-01

    The transition to lactation period in dairy cattle is characterized by metabolic challenges, negative energy balance, and adipose tissue mobilization. Metabolism of mobilized adipose tissue is part of the adaptive response to negative energy balance in dairy cattle; however, the capacity of the liver to completely oxidize nonesterified fatty acids may be limited and is reflective of oxaloacetate pool, the carbon carrier of the tricarboxylic acid cycle. Alternative metabolic fates of acetyl-CoA from nonesterified fatty acids include esterification to triacylglycerides and ketogenesis, and when excessive, these pathways lead to fatty liver and ketosis. Examination of the anaplerotic and cataplerotic pull of oxaloacetate by the tricarboxylic acid cycle and gluconeogenesis may provide insight into the balance of oxidation and esterification of acetyl-CoA within the liver of periparturient dairy cows. PMID:26479386

  19. Quantification of PEGylated proteases with varying degree of conjugation in mixtures: An analytical protocol combining protein precipitation and capillary gel electrophoresis.

    PubMed

    Morgenstern, Josefine; Busch, Markus; Baumann, Pascal; Hubbuch, Jürgen

    2016-09-02

    PEGylation, i.e. the covalent attachment of chemically activated polyethylene glycol (PEG) to proteins, is a technique commonly used in biopharmaceutical industry to improve protein stability, pharmacokinetics and resistance to proteolytic degradation. Therefore, PEGylation represents a valuable strategy to reduce autocatalysis of biopharmaceutical relevant proteases during production, purification and storage. In case of non-specific random conjugation the existence of more than one accessible binding site results in conjugates which vary in position and number of attached PEG molecules. These conjugates may differ considerably in their physicochemical properties. Optimizing the reaction conditions with respect to the degree of PEGylation (number of linked PEG molecules) using high-throughput screening (HTS) technologies requires a fast and reliable analytical method which allows stopping the reaction at defined times. In this study an analytical protocol for PEGylated proteases is proposed combining preservation of sample composition by trichloroacetic acid (TCA) precipitation with high-throughput capillary gel electrophoresis (HT-CGE). The well-studied protein hen egg-white lysozyme served as a model system for validating the newly developed analytical protocol for 10kDa mPEG-aldehyde conjugates. PEGamer species were purified by chromatographic separation for calibrating the HT-CGE system. In a case study, the serine protease Savinase(®) which is highly sensitive to autocatalysis was randomly modified with 5kDa and 10kDa mPEG-aldehyde and analyzed. Using the presented TCA protocol baseline separation between PEGamer species was achieved allowing for the analysis of heterogeneous PEGamer mixtures while preventing protease autocatalysis.

  20. Aluminum colloid formation and its effect on co-precipitation of zinc during acid rock drainage remediation with clinoptilolite in a slurry bubble column

    NASA Astrophysics Data System (ADS)

    Xu, W.; Li, L. Y.; Grace, J. R.

    2012-04-01

    Zinc and other metal ions were adsorbed in a laboratory slurry bubble column (SBC) by natural clinoptilolite sorbent particles. During the remediation process, significant white precipitates were sometimes observed. Both zinc and aluminum were detected in the colloidal mixtures. It is shown that Al leached from clinoptilolite during the agitation, contributing to the precipitate. As a result of the Al leaching and increase of pH during the remediation process, the formation of an Al colloid and zinc adsorption onto it could significantly improve ARD remediation, given the high adsorption capacity of the colloid. Sorption of cations increased with increasing colloid formation. Various conditions were tested to investigate their impact on (a) dealumination of clinoptilolite; (b) Al hydrolysis/colloid formation; and (c) adsorption onto the colloidal mixture. The test results indicate that dealumination contributes to the excess aluminum in the aqueous phase and to precipitates. The excess dealumination varies with pH and agitation time. Al hydrolysis occurs with increasing pH due to the neutralization effect of clinoptilolite. A significant proportion of zinc adsorbed onto the collectible aluminum precipitates.

  1. Histological evaluation of the effect of three medicaments; trichloracetic acid, formocresol and mineral trioxide aggregate on pulpotomised teeth of dogs.

    PubMed

    Karami, Babak; Khayat, Akbar; Moazami, Fariborz; Pardis, Soheil; Abbott, Paul

    2009-04-01

    The aim of this study was to use clinical, radiographic and histological examinations to compare the dental pulp response in 162 premolar roots of eight dogs when trichloracetic acid (TCA), formocresol, mineral trioxide aggregate (MTA) and zinc oxide eugenol were used as pulpotomy agents. The teeth were divided into four groups. Following pulpotomy, the teeth were restored with amalgam. The animals were sacrificed at 48 h, 2, 4 and 8 weeks (two dogs at each interval). Histological evaluation indicated no cases with necrosis. After 8 weeks follow up, dentine bridge formation was evident in 20%, 50% and 91.7% of formocresol, TCA and MTA cases respectively. The first signs of bridge formation were seen for MTA at 2 weeks and for TCA at 4 weeks. MTA was superior to formocresol and TCA in treating pulps in dogs. However, bridge formation was seen in 50% of TCA cases after 8 weeks which is a desirable finding in pulpotomy procedures.

  2. Citric acid as the last therapeutic approach in an acute life-threatening metabolic decompensation of propionic acidaemia.

    PubMed

    Siekmeyer, Manuela; Petzold-Quinque, Stefanie; Terpe, Friederike; Beblo, Skadi; Gebhardt, Rolf; Schlensog-Schuster, Franziska; Kiess, Wieland; Siekmeyer, Werner

    2013-01-01

    The tricarboxylic acid (TCA) cycle represents the key enzymatic steps in cellular energy metabolism. Once the TCA cycle is impaired in case of inherited metabolic disorders, life-threatening episodes of metabolic decompensation and severe organ failure can arise. We present the case of a 6 ½-year-old girl with propionic acidaemia during an episode of acute life-threatening metabolic decompensation and severe lactic acidosis. Citric acid given as an oral formulation showed the potential to sustain the TCA cycle flux. This therapeutic approach may become a treatment option in a situation of acute metabolic crisis, possibly preventing severe disturbance of energy metabolism.

  3. Species and strain sensitivity to the induction of peroxisome proliferation by chloroacetic acids.

    PubMed

    DeAngelo, A B; Daniel, F B; McMillan, L; Wernsing, P; Savage, R E

    1989-11-01

    B6C3F1 mice and Sprague-Dawley rats were provided drinking water containing 6-31 mM (1-5 g/liter) trichloroacetic acid (TCA), 8-39 mM (1-5 g/liter) dichloroacetic acid (DCA), or 11-32 mM (1-3 g/liter) monochloroacetic acid (MCA) for 14 days. TCA and DCA, but not MCA, increased the mouse relative liver weight in a dose-dependent manner. Rat liver weights were not altered by TCA or DCA treatment, but were depressed by MCA. Hepatic peroxisome proliferation was demonstrated by (1) increased palmitoyl-CoA oxidase and carnitine acetyl transferase activities, (2) appearance of a peroxisome proliferation-associated protein, and (3) morphometric analysis of electron micrographs. Mouse peroxisome proliferation was enhanced in a dose-dependent manner by both TCA and DCA, but only the high DCA concentration (39 mM) increased rat liver peroxisome proliferation. MCA was ineffective in both species. Three other mouse strains (Swiss-Webster, C3H, and C57BL/6) and two strains of rat (F344 and Osborne-Mendel) were examined for sensitivity to TCA. TCA (12 and 31 mM) effectively enhanced peroxisome proliferation in all mouse strains, especially the C57BL/6. A more modest enhancement in the Osborne-Mendel (288%) and F344 rat (167%) was seen. Dosing F344 rats with 200 mg/kg TCA in water or corn oil for 10 days increased peroxisome proliferation 179 and 278%, respectively, above the vehicle controls. These studies demonstrate that the mouse is more sensitive than the rat with respect to the enhancement of liver peroxisome proliferation by TCA and DCA and suggest that if peroxisome proliferation is critical for the induction of hepatic cancer by TCA and DCA, then the rat should be less sensitive or refractory to tumor induction.

  4. PRECIPITATION OF PLUTONOUS PEROXIDE

    DOEpatents

    Barrick, J.G.; Manion, J.P.

    1961-08-15

    A precipitation process for recovering plutonium values contained in an aqueous solution is described. In the process for precipitating plutonium as plutonous peroxide, hydroxylamine or hydrazine is added to the plutoniumcontaining solution prior to the addition of peroxide to precipitate plutonium. The addition of hydroxylamine or hydrazine increases the amount of plutonium precipitated as plutonous peroxide. (AEC)

  5. ROCK inhibitor Y-27632 inhibits the growth, migration, and invasion of Tca8113 and CAL-27 cells in tongue squamous cell carcinoma.

    PubMed

    Wang, Zhi-Ming; Yang, Dong-Sheng; Liu, Jie; Liu, Hong-Bo; Ye, Ming; Zhang, Yu-Fei

    2016-03-01

    The objective of this study is to determine the effects of Rho-associated coiled-coil containing protein kinase (ROCK) inhibitor Y-27632 on the growth, invasion, and migration of Tca8113 and CAL-27 cells in tongue squamous cell carcinoma (TSCC). The methods of the study are as follows: After being routinely cultured for 24 h, Tca8113 and CAL-27 cells were treated with Y-27632 solution. The morphological change of Y-27632-treated cells was observed under an optical microscope and an inverted microscope; MTT assay was performed to measure the optical density (OD) of cells and calculate cell growth inhibition rate; the change of apoptosis was detected by AnnexinV-FITC/PI assay; cell invasion and migration were measured by Transwell assay. The results were as follows: (1) With increasing concentration of Y-27632, cell morphology changed and cell apoptosis appeared; (2) MTT assay showed that inhibition effect of Y-27632 on Tca8113 and CAL-27 cells was enhanced with increasing concentrations and time (all P < 0.01); (3) Apoptosis showed that, compared with controls, the number of apoptosis cells in experimental groups was significantly increased (all P < 0.01). Apoptosis rate was elevated with increasing concentrations of Y-27632; (4) Transwell assay showed, after a treatment with Y-27632, the number of migrated and invaded Tca8113 and CAL-27 cells in each group was statistically different (all P < 0.01); compared with controls, the number of migrated cell in groups treated with Y-27632 was decreased and less Tca8113 and CAL-27 cells in experimental groups passed through polycarbonate membrane (all P < 0.05). The study concludes that Y-27632 can inhibit the growth, invasion, and migration of Tca8113 and CAL-27 cells, suggesting that Y-27632 may be therapeutically useful in TSCC.

  6. Hydrocarbonates in precipitation of Moscow

    NASA Astrophysics Data System (ADS)

    Larin, Igor; Eremina, Iren; Aloyan, Artash; Arutunan, Vardan; Chubarova, Natalia; Yermakov, Alexandr

    2016-04-01

    According to monitoring of the atmospheric precipitation of Moscow a number of episodes is revealed, the content of hydrocarbonates in which repeatedly surpasses equilibrium level. Facts of their registration are linked to complex structure of precipitation which is caused by a different chemical composition of condensation nucleus. As a result on the underlying surface two groups of drops with acidity of the different nature are transferred. The acidity of the first, "metal" group of droplets, is determined by a carbonate equilibrium with atmospheric CO2 and with dissolved carbonates of alkali and alkaline earth metals. The acidity of the second, "ammonium" group droplets, is characterized by the balance between an ammonia absorbed from the air and atmospheric acids. Regulation of acidity of the deposits measured in a course of monitoring, occurs for this reason not only in the air, but also in the condensate receiver. A mixing "metal" and "ammonium" groups precipitation accompanied by only a partial transfer of hydrocarbonates in the dissolved CO2. The process is braked as a result of a practical stop of exit of CO2 into the atmosphere because of a mass transfer deceleration. In turn it leads to excess of equilibrium level of hydrocarbonates in the receiver. Estimates show that the acidity of "ammonia" component of precipitation should be much higher than the reported monitoring data. In other words, real acidity of rain drops can essentially exceed that is measured by standard procedures of monitoring of deposits, that it is necessary to take into consideration at calculations of so-called critical levels of acid loading on people and environment. In other words, the actual acidity of raindrops could greatly exceed that is measured by the standard procedures for monitoring rainfall, which should be taken into account when calculating the so-called critical levels of acid loads on people and the environment. It follows that the true level of hazard of acid rain

  7. Aircraft Emission Scenarios Projected in Year 2015 for the NASA Technology Concept Aircraft (TCA) High Speed Civil Transport

    NASA Technical Reports Server (NTRS)

    Baughcum, Steven L.; Henderson, Stephen C.

    1998-01-01

    This report describes the development of a three-dimensional database of aircraft fuel burn and emissions (fuel burned, NOx, CO, and hydrocarbons) from projected fleets of high speed civil transports (HSCTs) on a universal airline network. Inventories for 500 and 1000 HSCT fleets, as well as the concurrent subsonic fleets, were calculated. The HSCT scenarios are calculated using the NASA technology concept airplane (TCA) and update an earlier report. These emissions inventories are available for use by atmospheric scientists conducting the Atmospheric Effects of Stratospheric Aircraft (AESA) modeling studies. Fuel burned and emissions of nitrogen oxides (NOx as NO2), carbon monoxide, and hydrocarbons have been calculated on a 1 degree latitude x 1 degree longitude x 1 kilometer pressure altitude grid and delivered to NASA as electronic files.

  8. 35CI NQR Spectroscopy on Salts and Molecular Compounds of Trichloroacetic Acid

    NASA Astrophysics Data System (ADS)

    Fichtner, Winfried; Markworth, Axel; Weiden, Norbert; Weiss, Alarich

    1986-02-01

    The temperature dependence of salts M(1)H(Cl3CCOO)2 and molecular compounds of trichloroacetic acid with amines and benzaldehydes, TCA · X, was studied, The data fit rather well to the known dependence of the mean frequency shift Δ on the pkadifference of X with respect to TCA. A linear relation is observed between the bleaching out temperature Tb of the 35Cl NQR lines and Δ for M(1)H(Cl3CCOO)2 and for TCA · X, X = benzaldehydes.

  9. Mechanisms by which acid precipitation produces embryonic death in aquatic vertebrates. Technical completion report, 1 May 1977-31 December 1980

    SciTech Connect

    Pough, F.H.

    1981-03-01

    Fourteen species of amphibians show a general similarity in their tolerance of acid media during embryonic development. More than 85% mortality is produced by pHs of 3.7 to 3.9 and more than 50% mortality occurs at pHs of 4.0 or less. Similar values have been reported for fishes. The sensitivity of amphibian embryos to acidity is greater in late stages of their development than it is during the initial cleavage of the embryos. The teratogenic effects of acidity appear to be the result of damage to the superficial tissues of the embryo. A similar response occurs in fish embryos. Because of the similarity of sensitivity and response to acidity of fishes and amphibians, the latter animals are suitable experimental models for investigations of the details of acid resistance. Controlled breedings of African clawed frogs (Xenopus laevis) indicated that the offspring of some pairs of parents were more resistant to acidity than those of other pairs. Wild populations of spotted salamanders (Ambystoma maculatum) breeding in some ponds in the Ithaca, New York, region have probably been exposed to increasingly acid conditions for the past three decades (10 or more generations). In the most acid ponds more than 70% of the embryos die before hatching. Despite the intensity and duration of this selection, it was not possible to demonstrate any difference in sensitivity to acidity between eggs collected from acidic and neutral breeding sites.

  10. A Simple Protein Precipitation-based Simultaneous Quantification of Lovastatin and Its Active Metabolite Lovastatin Acid in Human Plasma by Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry using Polarity Switching.

    PubMed

    Wujian, Ju; Kuan-Wei, Peng; Sihyung, Yang; Huijing, Sun; Mario, Sampson; Zhuo, Wang Michael

    2015-05-01

    Lovastatin is an anti-cholesterol lactone drug indicated for the treatment of hyperlipidemia and to reduce the risk of coronary heart disease. It is converted to the β-hydroxy acid form (lovastatin acid) in vivo, which is the major pharmacologically active metabolite. Here, we describe the development and validation of an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)-based method utilizing polarity switching for the simultaneous quantification of lovastatin and lovastatin acid in human plasma. Simple protein precipitation extraction and direct injection of the extracted samples without drying/reconstitution showed good recoveries of both analytes (~70%). The developed method exhibited satisfactory intra-day and inter-day accuracy and precision. The interconversion between lovastatin and lovastatin acid during sample preparation and storage was minimal (< 1.9%). The lower limits of quantification were 0.5 and 0.2 nM (or 0.2 and 0.084 ng/mL) for lovastatin and lovastatin acid, respectively, using only 50 μL of plasma during extraction. The validated method was successfully applied to analyze plasma samples obtained from a healthy human subject who enrolled in a clinical drug interaction study involving lovastatin.

  11. Characterization of the metabolic interaction between trihalomethanes and chloroacetic acids using rat liver microsomes.

    PubMed

    St-Pierre, Annie; Krishnan, Kannan; Tardif, Robert

    2005-02-27

    The aim of this study was to investigate the in vitro metabolism of trihalomethanes (THMs) in the presence of trichloroacetic acid (TCA), dichloracetic acid (DCA), monochloroacetic acid (MCA), and 4-methylpyrazole (4-MP) using liver microsomes from male Sprague-Dawley rats. Using the vial equilibration technique, initial experiments were carried out with starting concentrations of approximately 40 ppm THMs and 12-22 mM chloroacetic acids. The results indicated a mutual metabolic inhibition between THMs present as binary or quaternary mixtures. Although DCA and MCA had no influence on THMs, TCA produced a marked inhibition of the metabolism of all THMs: chloroform (CHCl3) (55%), bromodichloromethane (BDCM) (34%), dibromochloromethane (DBCM) (30%), and bromoform (TBM) (23%). The presence of 4-MP also reduced THM metabolism, the importance of which decreased in the following order: CHCl3 > BDCM > DBCM = TBM. In further vial equilibration experiments, using 9-140 ppm as starting concentrations of THMs, enzyme kinetic parameters (i.e., Michaelis constant, K(m), and maximum velocity, V(max)) were determined both in the absence and in the presence of TCA (12.2 mM). Results are consistent with a competitive inhibition between TCA and CHCl3, whereas the metabolic inhibition of BDCM and TMB by TCA was non-competitive. As for DBCM, results suggest a more complex pattern of inhibition. These results suggest that CYP2E1 is involved in the metabolism of THMs as well as in the metabolic interaction between THMs and TCA.

  12. Biosynthesis of the 1,3,4,6-hexanetetracarboxylic acid subunit of methanofuran

    SciTech Connect

    White, R.H.

    1987-06-02

    /sup 2/H- and /sup 13/C-labeled precursors were used to establish the pathway for the biosynthesis of the 1,3,4,6-hexanetetracarboxylic acid (TCA) component of methanofuran, which is found in some methanogenic bacteria. The extent and position of incorporation of label into TCA were measured from the mass spectrum of the tetramethyl ester of TCA that was prepared from methanofuran present in cells grown in the presence of labeled acetate. (2,2,2-/sup 2/H/sub 3/)Acetate was found to incorporate deuterium into two separate sites of the TCA molecule, with one on each side of the symmetrical molecule. One site was found to be labeled 37% with deuterium, the same as for the glutamic acid present in the cells; the other site was labeled 77% with deuterium, the same as for the malonate-derived compounds in the cells. An analog of TCA, 1-hydroxy-1,3,4,6-hexanetetracarboxylic acid, found in methanofuran isolated from Methanobrevibacter smithii, was found to incorporate /sup 13/C/sub 2/ units from (1,2-/sup 13/C/sub 2/)acetate into three positions of the molecule. One of the acetate /sup 13/C/sub 2/ units was incorporated into the non-hydroxyl-containing side of the molecule (carbons 4, 5, and 6 and the C-6 carboxylic acid group), and two acetate units were incorporated into the hydroxyl-containing side of the molecule (carbons 1, 2, and 3 and the C-1 carboxylic acid group). On the basis of this and additional information, it is concluded that TCA is biosynthesized by the condensation of ..cap alpha..-ketoglutaric acid with malonic acid to form 1,1,2,4-butanetetracarboxylic acid, which is further condensed with a second molecule of malonate, in a series of reactions analogous to those observed during fatty acid biosynthesis, to form TCA.

  13. A micro-TCA based data acquisition system for the Triple-GEM detectors for the upgrade of the CMS forward muon spectrometer

    NASA Astrophysics Data System (ADS)

    Lenzi, T.

    2017-01-01

    The Gas Electron Multiplier (GEM) upgrade project aims at improving the performance of the muon spectrometer of the Compact Muon Solenoid (CMS) experiment which will suffer from the increase in luminosity of the Large Hadron Collider (LHC). The GEM collaboration proposes to instrument the first muon station with Triple-GEM detectors, a technology which has proven to be resistant to high fluxes of particles. The architecture of the readout system is based on the use of the microTCA standard hosting FPGA-based Advanced Mezzanine Card (AMC) and of the Versatile Link with the GBT chipset to link the on-detector electronics to the micro-TCA boards. For the front-end electronics a new ASIC, called VFAT3, is being developed. On the detector, a Xilinx Virtex-6 FPGA mezzanine board, called the OptoHybrid, has to collect the data from 24 VFAT3s and to transmit the data optically to the off-detector micro-TCA electronics, as well as to transmit the trigger data at 40 MHz to the CMS Cathode Strip Chamber (CSC) trigger. The microTCA electronics provides the interfaces from the detector (and front-end electronics) to the CMS DAQ, TTC (Timing, Trigger and Control) and Trigger systems. In this paper, we will describe the DAQ system of the Triple-GEM project and provide results from the latest test beam campaigns done at CERN.

  14. Precipitation Climate Data Records

    NASA Astrophysics Data System (ADS)

    Nelson, B. R.; Prat, O.; Vasquez, L.

    2015-12-01

    Five precipitation CDRs are now or soon will be transitioned to NOAA's CDR program. These include the PERSIANN data set, which is a 30-year record of daily adjusted global precipitation based on retrievals from satellite microwave data using artificial neural networks. The AMSU-A/B/Hydrobundle is an 11-year record of precipitable water, cloud water, ice water, and other variables. CMORPH (the NOAA Climate Prediction Center Morphing Technique) is a 17-year record of daily and sub-daily adjusted global precipitation measured from passive microwave and infrared data at high spatial and temporal resolution. GPCP (the Global Precipitation Climatology Project) is an approximately 30-year record of monthly and pentad adjusted global precipitation and a 17-year record of daily adjusted global precipitation. The NEXRAD Reanalysis is a 10-year record of high resolution NEXRAD radar based adjusted CONUS-wide hourly and daily precipitation. This study provides an assessment of the existing and transitioned long term precipitation CDRs and includes the verification of the five precipitation CDRs using various methods including comparison with in-situ data sets and trend analysis. As all of the precipitation related CDRs are transitioned, long term analyses can be performed. Comparisons at varying scales (hourly, daily and longer) of the precipitation CDRs with in-situ data sets are provided as well as a first look at what could be an ensemble long term precipitation data record.

  15. Uncertainty of Prebiotic Scenarios: The Case of the Non-Enzymatic Reverse Tricarboxylic Acid Cycle

    PubMed Central

    Zubarev, Dmitry Yu; Rappoport, Dmitrij; Aspuru-Guzik, Alán

    2015-01-01

    We consider the hypothesis of the primordial nature of the non-enzymatic reverse tricarboxylic acid (rTCA) cycle and describe a modeling approach to quantify the uncertainty of this hypothesis due to the combinatorial aspect of the constituent chemical transformations. Our results suggest that a) rTCA cycle belongs to a degenerate optimum of auto-catalytic cycles, and b) the set of targets for investigations of the origin of the common metabolic core should be significantly extended. PMID:25620471

  16. Acid precipitation: effects on fresh-water ecosystems. January 1978-September 1988 (Citations from the Life Sciences Collection data base). Report for January 1978-September 1988

    SciTech Connect

    Not Available

    1988-10-01

    This bibliography contains citations concerning the effects of acidification of fresh-water ecosystems. Algae and diatom distribution, survival, and reproduction rates of specific fish species under acid-lake conditions, and tolerance to stress caused by acidic conditions in fresh water ecosystems are studied. Effects of water ph on trace metal toxicity to fresh water organisms is briefly considered. Control and reduction of acidification is excluded from this bibliography. (Contains 290 citations fully indexed and including a title list.)

  17. Metabolic engineering in the biotechnological production of organic acids in the tricarboxylic acid cycle of microorganisms: Advances and prospects.

    PubMed

    Yin, Xian; Li, Jianghua; Shin, Hyun-Dong; Du, Guocheng; Liu, Long; Chen, Jian

    2015-11-01

    Organic acids, which are chemically synthesized, are also natural intermediates in the metabolic pathways of microorganisms, among which the tricarboxylic acid (TCA) cycle is the most crucial route existing in almost all living organisms. Organic acids in the TCA cycle include citric acid, α-ketoglutaric acid, succinic acid, fumaric acid, l-malic acid, and oxaloacetate, which are building-block chemicals with wide applications and huge markets. In this review, we summarize the synthesis pathways of these organic acids and review recent advances in metabolic engineering strategies that enhance organic acid production. We also propose further improvements for the production of organic acids with systems and synthetic biology-guided metabolic engineering strategies.

  18. Bile acids regulate intestinal cell proliferation by modulating EGFR and FXR signaling

    PubMed Central

    Dossa, Avafia Y.; Escobar, Oswaldo; Golden, Jamie; Frey, Mark R.; Ford, Henri R.

    2015-01-01

    Bile acids (BAs) are synthesized in the liver and secreted into the intestine. In the lumen, enteric bacteria metabolize BAs from conjugated, primary forms into more toxic unconjugated, secondary metabolites. Secondary BAs can be injurious to the intestine and may contribute to disease. The epidermal growth factor receptor (EGFR) and the nuclear farnesoid X receptor (FXR) are known to interact with BAs. In this study we examined the effects of BAs on intestinal epithelial cell proliferation and investigated the possible roles for EGFR and FXR in these effects. We report that taurine-conjugated cholic acid (TCA) induced proliferation, while its unconjugated secondary counterpart deoxycholic acid (DCA) inhibited proliferation. TCA stimulated phosphorylation of Src, EGFR, and ERK 1/2. Pharmacological blockade of any of these pathways or genetic ablation of EGFR abrogated TCA-stimulated proliferation. Interestingly, Src or EGFR inhibitors eliminated TCA-induced phosphorylation of both molecules, suggesting that their activation is interdependent. In contrast to TCA, DCA exposure diminished EGFR phosphorylation, and pharmacological or siRNA blockade of FXR abolished DCA-induced inhibition of proliferation. Taken together, these results suggest that TCA induces intestinal cell proliferation via Src, EGFR, and ERK activation. In contrast, DCA inhibits proliferation via an FXR-dependent mechanism that may include downstream inactivation of the EGFR/Src/ERK pathway. Since elevated secondary BA levels are the result of specific bacterial modification, this may provide a mechanism through which an altered microbiota contributes to normal or abnormal intestinal epithelial cell proliferation. PMID:26608185

  19. Recovery of Plutonium by Carrier Precipitation

    DOEpatents

    Goeckermann, R. H.

    1961-04-01

    The recovery of plutonium from an aqueous nitric acid Zr-containing solution of 0.2 to 1N acidity is accomplished by adding fluoride anions (1.5 to 5 mg/l), and precipitating the Pu with an excess of H/sub 2/0/sub 2/ at 53 to 65 deg C. (AEC)

  20. RECOVERY OF PLUTONIUM BY CARRIER PRECIPITATION

    DOEpatents

    Goeckermann, R.H.

    1961-04-01

    A process is given for recovering plutonium from an aqueous nitric acid zirconium-containing solution of an acidity between 0.2 and 1 N by adding fluoride anions (1.5 to 5 mg/l) and precipitating the plutonium with an excess of hydrogen peroxide at from 53 to 65 deg C.

  1. Acid precipitation: Effects on fresh-water ecosystems. April 1978-January 1990 (A Bibliography from the Life Sciences Collection data base). Report for April 1978-January 1990

    SciTech Connect

    Not Available

    1990-06-01

    This bibliography contains citations concerning the effects of acidification on fresh water ecosystems. Algae and diatom distribution, survival and reproduction rates of specific fish species under acid lake conditions, and tolerance to stress caused by acidic conditions in fresh water ecosystems are studied. Effects of water pH on trace metal toxicity to fresh water organisms are briefly considered. Control and reduction of acidification are excluded from this bibliography. (This updated bibliography contains 331 citations, 41 of which are new entries to the previous edition.)

  2. N- Trichloro- and dichloroacetyl amino acids and compounds of amino acids with halogeno acetic acids: 35Cl nuclear quadrupole resonance spectroscopy; crystal structure of N- trichloroacetyl- glycine, - DL-alanine, and - L-alanine

    NASA Astrophysics Data System (ADS)

    Dou, Shi-qi; Kehrer, Armin; Ofial, Armin R.; Weiss, Alarich

    1995-02-01

    The crystal structures of N- trichloroacetyl- glycine ( N- TCA- G), N-trichloroacetyl-dl-alanine ( N-TCA- dl-A ), and N-trichloroacetyl- l-alanine ( N-TCA- l-A ) were determined. In addition, the 35Cl NQR spectra of these N-trichloroacetyl amino acids, of N-trichloroacetyl- l-valine ( N-TCA- l-V ), and of N- dichloroacetyl- glycine and - L-alanine were measured, mostly as a function of temperature. Compounds of glycine and L-alanine with chlorodifluoroacetic acid, of glycine and L-leucine with monochloroacetic acid, of glycine and L-leucine with dichloroacetic acid, and of glycine and L-leucine with trichloroacetic acid were also studied using 35Cl NQR. The structures (in picometres and degrees) were found to be as follows. N- TCA- G: Pna2 1, Z = 8, a = 1641, b = 1002, c = 1018. N-TCA- dl-A : {C2}/{c}, Z = 8, a = 3280, b = 556, c = 1031, β = 96.68. N-TCA- l-A: P1 , Z = 2, a = 967, b = 949, c = 619, α = 74.97, β = 74.20, γ = 61.20. The 35Cl NQR frequencies (ν) were observed in the range 35-41 MHz, and decrease with increasing temperature. Some of the resonances bleach out at a temperature ( Tb) far below the melting temperature; this provides information about the crystal structures at 77 K. No phase transitions were observed by differential thermal analysis between 77 and 295 K. The crystal structures are discussed in connection with the NQR results, and conclusions are drawn about the structures of the compounds for which only 35Cl NQR data are available.

  3. Acid Rain.

    ERIC Educational Resources Information Center

    Openshaw, Peter

    1987-01-01

    Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

  4. The CMS fast beams condition monitor back-end electronics based on MicroTCA technology: status and development

    NASA Astrophysics Data System (ADS)

    Zagozdzinska, Agnieszka A.; Dabrowski, Anne E.; Pozniak, Krzysztof T.

    2015-09-01

    The Fast Beams Condition Monitor (BCM1F), upgraded for LHC Run II, is used to measure the online luminosity and machine induced background for the CMS experiment. The detector consists of 24 single-crystal CVD diamond sensors that are read out with a custom fast front-end chip fabricated in 130 nm CMOS technology. Since the signals from the sensors are used for real time monitoring of the LHC conditions they are processed by dedicated back-end electronics to measure separately rates corresponding to LHC collision products, machine induced background and residual activation exploiting different arrival times. The system is built in MicroTCA technology and uses high speed analog-to-digital converters. In operational modes of high rates, consecutive events, spaced in time by less than 12.5 ns, may cause partially overlapping events. Hence, novel signal processing techniques are deployed to resolve overlapping peaks. The high accuracy qualification of the signals is crucial to determine the luminosity and the machine induced background rates for the CMS experiment and the LHC.

  5. The role of surface chemical analysis in a study to select replacement processes for TCA vapor degreasing

    NASA Technical Reports Server (NTRS)

    Lesley, Michael W.; Davis, Lawrence E.; Moulder, John F.; Carlson, Brad A.

    1995-01-01

    The role of surface-sensitive chemical analysis (ESCA, AES, and SIMS) in a study to select a process to replace 1, 1, 1-trichloroethane (TCA) vapor degreasing as a steel and aluminum bonding surface preparation method is described. The effort was primarily concerned with spray-in-air cleaning processes involving aqueous alkaline and semi-aqueous cleaners and a contamination sensitive epoxy-to-metal bondline. While all five cleaners tested produced bonding strength results equal to or better than those produced by vapor degreasing, the aqueous alkaline cleaners yielded results which were superior to those produced by the semi-aqueous cleaners. The main reason for the enhanced performance appears to be a silicate layer left behind by the aqueous alkaline cleaners. The silicate layer increases the polarity of the surface and enhances epoxy-to-metal bonding. On the other hand, one of the semi-aqueous cleaners left a nonpolar carbonaceous residue which appeared to have a negative effect on epoxy-to-metal bonding. Differences in cleaning efficiency between cleaners/processes were also identified. These differences in surface chemistry, which were sufficient to affect bonding, were not detected by conventional chemical analysis techniques.

  6. Mitochondria-translocated phosphoglycerate kinase 1 functions as a protein kinase to coordinate glycolysis and TCA cycle in tumorigenesis

    PubMed Central

    Li, Xinjian; Jiang, Yuhui; Meisenhelder, Jill; Yang, Weiwei; Hawke, David H.; Zheng, Yanhua; Xia, Yan; Aldape, Kenneth; He, Jie; Hunter, Tony; Wang, Liwei; Lu, Zhimin

    2016-01-01

    SUMMARY It is unclear how the Warburg effect that exemplifies enhanced glycolysis in the cytosol is coordinated with suppressed mitochondrial pyruvate metabolism. We demonstrate here that hypoxia, EGFR activation, and expression of K-Ras G12V and B-Raf V600E induce mitochondrial translocation of phosphoglycerate kinase 1 (PGK1); this is mediated by ERK-dependent PGK1 S203 phosphorylation and subsequent PIN1-mediated cis–trans isomerization. Mitochondrial PGK1 acts as a protein kinase to phosphorylate pyruvate dehydrogenase kinase 1 (PDHK1) at T338, which activates PDHK1 to phosphorylate and inhibit the pyruvate dehydrogenase (PDH) complex. This reduces mitochondrial pyruvate utilization, suppresses reactive oxygen species production, increases lactate production, and promotes brain tumorigenesis. Furthermore, PGK1 S203 and PDHK1 T338 phosphorylation levels correlate with PDH S293 inactivating phosphorylation levels and poor prognosis in glioblastoma patients. This work highlights that PGK1 act as a protein kinase in coordinating glycolysis and the TCA cycle, which is instrumental in cancer metabolism and tumorigenesis. PMID:26942675

  7. Reducing endocannabinoid metabolism with the fatty acid amide hydrolase inhibitor, URB597, fails to modify reinstatement of morphine-induced conditioned floor preference and naloxone-precipitated morphine withdrawal-induced conditioned floor avoidance.

    PubMed

    McCallum, Amanda L; Limebeer, Cheryl L; Parker, Linda A

    2010-10-01

    The potential of the fatty acid amide hydrolase (FAAH) inhibitor, URB597, to modify drug prime-induced reinstatement of morphine-induced conditioned floor preference or naloxone-precipitated morphine withdrawal-induced conditioned floor avoidance was evaluated. In Experiment 1, morphine-induced conditioned floor preference was established across 4 conditioning trials. Following extinction training (4 trials), rats were pretreated with URB597 or vehicle prior to a morphine prime or a saline prime. Morphine reinstated the previously extinguished floor preference, but URB597 did not modify the strength of the reinstated preference. In Experiment 2, naloxone-precipitated morphine withdrawal-induced conditioned floor avoidance was established across 2 conditioning trials. Following extinction training (14 trials), rats were pretreated with URB597 or vehicle prior to a saline prime or a morphine withdrawal prime. The morphine withdrawal prime reinstated the previously extinguished floor avoidance, but URB597 did not modify the strength of reinstated avoidance. These results suggest that under the conditions in which URB597 promotes extinction (e.g., Manwell et al. (2009)) it does not interfere with drug-induced reinstatement of either conditioned floor preference or avoidance. That is, although activation of the endocannabinoid (eCB) system promotes extinction of aversive learning, it may not prevent reinstatement of that aversion by re-exposure to the aversive treatment.

  8. Determination of methylphenidate and ritalinic acid in blood, plasma and oral fluid from adolescents and adults using protein precipitation and liquid chromatography tandem mass spectrometry--a method applied on clinical and forensic investigations.

    PubMed

    Josefsson, Martin; Rydberg, Irene

    2011-07-15

    A validated, accurate and sensitive LC-MS/MS method for determination of racemic methylphenidate and its metabolite ritalinic acid has been developed. The analytes were quantified by tandem mass spectrometry operating in positive electrospray ionization mode with multiple reaction monitoring. Blood, plasma and oral fluid samples of 100μl were prepared by simple precipitation with 200μl of an aqueous solution of zinc sulphate in methanol. Corresponding deuterated internal standards were used for quantification. Calibrations for methylphenidate and ritalinic acid were linear within the selected range of 0.2-30ng/ml and 10-1500ng/ml in blood or plasma and in the range of 1-500ng/ml and 0.25-125ng/ml in oral fluid, respectively. The method was successfully applied for the analysis of samples from patients treated with methylphenidate in the dose range of 36-72mg/day and some representative ante mortem and post mortem samples from clinical and forensic toxicological investigations. A three to fourfold higher concentration of methylphenidate was found in oral fluid compared with blood while for ritalinic acid the concentrations were about 25-fold lower in oral fluid.

  9. IMPROVED PROCESS OF PLUTONIUM CARRIER PRECIPITATION

    DOEpatents

    Faris, B.F.

    1959-06-30

    This patent relates to an improvement in the bismuth phosphate process for separating and recovering plutonium from neutron irradiated uranium, resulting in improved decontamination even without the use of scavenging precipitates in the by-product precipitation step and subsequently more complete recovery of the plutonium in the product precipitation step. This improvement is achieved by addition of fluomolybdic acid, or a water soluble fluomolybdate, such as the ammonium, sodium, or potassium salt thereof, to the aqueous nitric acid solution containing tetravalent plutonium ions and contaminating fission products, so as to establish a fluomolybdate ion concentration of about 0.05 M. The solution is then treated to form the bismuth phosphate plutonium carrying precipitate.

  10. Genetic Investigation of Tricarboxylic Acid Metabolism During the Plasmodium falciparum Lifecycle

    PubMed Central

    Ke, Hangjun; Lewis, Ian A.; Morrisey, Joanne M.; McLean, Kyle J.; Ganesan, Suresh M.; Painter, Heather J.; Mather, Michael W.; Jacobs-Lorena, Marcelo; Llinás, Manuel; Vaidya, Akhil B.

    2015-01-01

    SUMMARY New antimalarial drugs are urgently needed to control drug resistant forms of the malaria parasite, Plasmodium falciparum. Mitochondrial electron transport is the target of both existing and new antimalarials. Herein, we describe 11 genetic knockout (KO) lines that delete six of the eight mitochondrial tricarboxylic acid (TCA) cycle enzymes. Although all TCA KOs grew normally in asexual blood stages, these metabolic deficiencies halted lifecycle progression in later stages. Specifically, aconitase KO parasites arrested as late gametocytes, whereas α-ketoglutarate dehydrogenase deficient parasites failed to develop oocysts in the mosquitoes. Mass spectrometry analysis of 13C isotope-labeled TCA mutant parasites showed that P. falciparum has significant flexibility in TCA metabolism. This flexibility manifested itself through changes in pathway fluxes and through altered exchange of substrates between cytosolic and mitochondrial pools. Our findings suggest that mitochondrial metabolic plasticity is essential for parasite development. PMID:25843709

  11. Akaganéite (β-FeOOH) precipitation in inland acid sulfate soils of south-western New South Wales (NSW), Australia

    NASA Astrophysics Data System (ADS)

    Bibi, Irshad; Singh, Balwant; Silvester, Ewen

    2011-11-01

    The prevalence of sulphidic sediments in inland wetlands has been only recently recognized in many parts of the world, including Australia. The exposure of sulphidic sediments in these wetlands due to natural and human induced drying events has resulted in the oxidation of iron sulfide minerals, the formation of secondary iron minerals characteristic of acid sulfate soils and the release of highly acidic solutions. The objective of this study was to determine the mineralogy and morphology of sediments collected from the oxidized surface horizon (0-5 cm) of an inland acid sulfate soil located in south-western New South Wales (NSW), Australia. Random powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning transmission electron microscopy combined with energy dispersive X-ray spectroscopy (STEM-EDS) techniques were used to characterize the minerals present in these sediments. Akaganéite was identified as the major mineral phase in the sediments; K-jarosite was also determined in small amounts in some sediments. The XRD patterns of sequentially washed (E-pure® water-0.01 M HCl-0.01 M EDTA) sediment samples showed all akaganéite peaks; the Rietveld refinement of these patterns also revealed a predominance of akaganéite. The chemical analyses of the original and washed sediments using STEM-EDS clearly showed the presence of akaganéite as a pure mineral phase with an average Fe/Cl mole ratio of 6.7 and a structural formula of Fe 8O 8(OH) 6.8(Cl) 1.2. These findings show that the extreme saline-acidic solutions (pH ˜ 2, EC = 216 dS/m) at the Bottle Bend lagoon provide ideal conditions for the crystallization of this rarely forming mineral.

  12. Ames Optimized TCA Configuration

    NASA Technical Reports Server (NTRS)

    Cliff, Susan E.; Reuther, James J.; Hicks, Raymond M.

    1999-01-01

    Configuration design at Ames was carried out with the SYN87-SB (single block) Euler code using a 193 x 49 x 65 C-H grid. The Euler solver is coupled to the constrained (NPSOL) and the unconstrained (QNMDIF) optimization packages. Since the single block grid is able to model only wing-body configurations, the nacelle/diverter effects were included in the optimization process by SYN87's option to superimpose the nacelle/diverter interference pressures on the wing. These interference pressures were calculated using the AIRPLANE code. AIRPLANE is an Euler solver that uses a unstructured tetrahedral mesh and is capable of computations about arbitrary complete configurations. In addition, the buoyancy effects of the nacelle/diverters were also included in the design process by imposing the pressure field obtained during the design process onto the triangulated surfaces of the nacelle/diverter mesh generated by AIRPLANE. The interference pressures and nacelle buoyancy effects are added to the final forces after each flow field calculation. Full details of the (recently enhanced) ghost nacelle capability are given in a related talk. The pseudo nacelle corrections were greatly improved during this design cycle. During the Ref H and Cycle 1 design activities, the nacelles were only translated and pitched. In the cycle 2 design effort the nacelles can translate vertically, and pitch to accommodate the changes in the lower surface geometry. The diverter heights (between their leading and trailing edges) were modified during design as the shape of the lower wing changed, with the drag of the diverter changing accordingly. Both adjoint and finite difference gradients were used during optimization. The adjoint-based gradients were found to give good direction in the design space for configurations near the starting point, but as the design approached a minimum, the finite difference gradients were found to be more accurate. Use of finite difference gradients was limited by the CPU time limit available on the Cray machines. A typical optimization run using finite difference gradients can use only 30 to 40 design variables and one optimization iteration within the 8 hour queue limit for the chosen grid size and convergence level. The efficiency afforded by the adjoint method allowed for 50-120 design variables and 5-10 optimization iterations in the 8 hour queue. Geometric perturbations to the wing and fuselage were made using the Hicks/Henne (HH) shape functions. The HH functions were distributed uniformly along the chords of the wing defining sections and lofted linearly. During single-surface design, constraints on thickness and volume at selected wing stations were imposed. Both fuselage camber and cross-sectional area distributions were permitted to change during design. The major disadvantage to the use of these functions is the inherent surface waviness produced by repeated use of such functions. Many smoothing operations were required following optimization runs to produce a configuration with reasonable smoothness. Wagner functions were also used on the wing sections but were never used on the fuselage. The Wagner functions are a family of increasingly oscillatory functions that have also been used extensively in airfoil design. The leading and trailing edge regions of the wing were designed by use of polynomial and monomial functions respectively. Twist was attempted but was abandoned because of little performance improvement available from changing the baseline twist.

  13. Global Precipitation Measurement

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.; Skofronick-Jackson, Gail; Kummerow, Christian D.; Shepherd, James Marshall

    2008-01-01

    This chapter begins with a brief history and background of microwave precipitation sensors, with a discussion of the sensitivity of both passive and active instruments, to trace the evolution of satellite-based rainfall techniques from an era of inference to an era of physical measurement. Next, the highly successful Tropical Rainfall Measuring Mission will be described, followed by the goals and plans for the Global Precipitation Measurement (GPM) Mission and the status of precipitation retrieval algorithm development. The chapter concludes with a summary of the need for space-based precipitation measurement, current technological capabilities, near-term algorithm advancements and anticipated new sciences and societal benefits in the GPM era.

  14. An acute decrease in TCA cycle intermediates does not affect aerobic energy delivery in contracting rat skeletal muscle.

    PubMed

    Dawson, Kristen D; Baker, David J; Greenhaff, Paul L; Gibala, Martin J

    2005-06-01

    We tested the hypothesis that an acute decrease in muscle TCA cycle intermediates during contraction would compromise aerobic energy delivery. Male Wistar rats were anaesthetized and the gastrocnemius-plantaris-soleus (GPS) muscle complex from one leg was isolated and perfused with a red cell medium containing either saline (Con) or cycloserine (Cyclo; 0.05 mg g-1), an inhibitor of alanine aminotransferase (AAT). After 1 h of perfusion, the GPS muscle was either snap frozen (Con-Rest, n=11; Cyclo-Rest, n=9) or stimulated to contract for 10 min (1 Hz, 0.3 ms, 2 V) with blood flow fixed at 30 ml min-1 (100 g)-1 and then snap frozen (Con-Stim, n=10; Cyclo-Stim, n=10). Maximal AAT activity was>80% lower (P<0.001) in both Cyclo-treated groups (Rest: 0.61+/-0.02; Stim: 0.63+/-0.01 mmol (kg wet wt)-1 min-1; mean+/-s.e.m.) compared to Con (Rest: 3.56+/-0.16; Stim: 3.92+/-0.29). The sum of five measured TCAI (SigmaTCAI) was reduced by 23% in Cyclo-Rest versus Con-Rest but this was not different (P=0.08). However, after 10 min of contraction, the SigmaTCAI was 25% lower (P=0.006) in Cyclo-Stim compared to Con-Stim (1.88+/-0.15 versus 2.48+/-0.11 mmol (kg dry wt)-1). Despite the acute decrease in TCAI after Cyclo treatment, the contraction-induced changes in markers of non-oxidative energy provision (phosphocreatine, ATP and lactate) and the decline in tension after 10 min of stimulation were similar compared to Con. These data do not support the hypothesis that the total muscle concentration of TCAI is causally linked to the rate of mitochondrial respiration during contraction.

  15. The Effect of Walterinnesia aegyptia Venom Proteins on TCA Cycle Activity and Mitochondrial NAD+-Redox State in Cultured Human Fibroblasts

    PubMed Central

    Ghneim, Hazem K.; Al-Sheikh, Yazeed A.; Aboul-Soud, Mourad A. M.

    2015-01-01

    Fibroblast cultures were used to study the effects of crude Walterinnesia aegyptia venom and its F1–F7 protein fractions on TCA cycle enzyme activities and mitochondrial NAD-redox state. Confluent cells were incubated with 10 μg of venom proteins for 4 hours at 37°C. The activities of all studied TCA enzymes and the non-TCA mitochondrial NADP+-dependent isocitrate dehydrogenase underwent significant reductions of similar magnitude (50–60% of control activity) upon incubation of cells with the crude venom and fractions F4, F5, and F7 and 60–70% for fractions F3 and F6. In addition, the crude and fractions F3–F7 venom proteins caused a drop in mitochondrial NAD+ and NADP+ levels equivalent to around 25% of control values. Whereas the crude and fractions F4, F5, and F7 venom proteins caused similar magnitude drops in NADH and NADPH (around 55% of control levels), fractions F3 and F6 caused a more drastic drop (60–70% of control levels) of both reduced coenzymes. Results indicate that the effects of venom proteins could be directed at the mitochondrial level and/or the rates of NAD+ and NADP+ biosynthesis. PMID:25705684

  16. The effect of Walterinnesia aegyptia venom proteins on TCA cycle activity and mitochondrial NAD(+)-redox state in cultured human fibroblasts.

    PubMed

    Ghneim, Hazem K; Al-Sheikh, Yazeed A; Aboul-Soud, Mourad A M

    2015-01-01

    Fibroblast cultures were used to study the effects of crude Walterinnesia aegyptia venom and its F1-F7 protein fractions on TCA cycle enzyme activities and mitochondrial NAD-redox state. Confluent cells were incubated with 10 μg of venom proteins for 4 hours at 37°C. The activities of all studied TCA enzymes and the non-TCA mitochondrial NADP(+)-dependent isocitrate dehydrogenase underwent significant reductions of similar magnitude (50-60% of control activity) upon incubation of cells with the crude venom and fractions F4, F5, and F7 and 60-70% for fractions F3 and F6. In addition, the crude and fractions F3-F7 venom proteins caused a drop in mitochondrial NAD(+) and NADP(+) levels equivalent to around 25% of control values. Whereas the crude and fractions F4, F5, and F7 venom proteins caused similar magnitude drops in NADH and NADPH (around 55% of control levels), fractions F3 and F6 caused a more drastic drop (60-70% of control levels) of both reduced coenzymes. Results indicate that the effects of venom proteins could be directed at the mitochondrial level and/or the rates of NAD(+) and NADP(+) biosynthesis.

  17. The anticancer activity of the fungal metabolite terrecyclic acid A is associated with modulation of multiple cellular stress response pathways.

    PubMed

    Turbyville, Thomas J; Wijeratne, E M Kithsiri; Whitesell, Luke; Gunatilaka, A A Leslie

    2005-10-01

    Tumors are dependent on cellular stress responses, in particular the heat shock response, for survival in their hypoxic, acidotic, and nutrient-deprived microenvironments. Using cell-based reporter assays, we have identified terrecyclic acid A (TCA) from Aspergillus terreus, a fungus inhabiting the rhizosphere of Opuntia versicolor of the Sonoran desert, as a small-molecule inducer of the heat shock response that shows anticancer activity. Further characterization suggested that TCA also affects oxidative and inflammatory cellular stress response pathways. The presence of an alpha-methylene ketone moiety suggested that TCA may form adducts with sulfhydryl groups of proteins. Reaction with labile intracellular cysteines was supported by our finding that the glutathione precursor N-acetyl-cysteine protected tumor cells from the cytotoxic effects of TCA whereas the glutathione-depleting agent buthionine sulfoximine enhanced its activity. Related sesquiterpenes have been shown to increase levels of reactive oxygen species (ROS) and to inhibit nuclear factor kappaB (NF-kappaB) transcriptional activity. To assess whether TCA could have similar activities, we used a ROS-sensitive dye and flow cytometry to show that TCA does indeed increase ROS levels in 3LL cells. When tested in cells carrying NF-kappaB reporter constructs, TCA also exhibited concentration-dependent inhibition of cytokine-induced NF-kappaB transcriptional activity. These findings suggest that TCA modulates multiple stress pathways-the oxidative, heat shock, and inflammatory responses-in tumor cells that promote their survival. Small-molecule natural products such as TCA may serve as useful probes for understanding the relationships between these pathways, potentially providing leads for the design of novel and effective anticancer drugs.

  18. [Metabolism of Yarrowia lipolytica grown on ethanol under conditions promoting the production of alpha-ketoglutaric and citric acids: a comparative study of the central metabolism enzymes].

    PubMed

    Il'chenko, A P; Cherniavskaia, O G; Shishkanova, N V; Finogenova, T V

    2002-01-01

    A comparative study of the enzymes of the tricarboxylic acid (TCA) and glyoxylate cycles in the mutant Yarrowia lipolytica strain N1 capable of producing alpha-ketoglutaric acid (KGA) and citric acid showed that almost all enzymes of the TCA cycle are more active under conditions promoting the production of KGA. The only exception was citrate synthase, whose activity was higher in yeast cells producing citric acid. The production of both acids was accompanied by suppression of the glyoxylate cycle enzymes. The activities of malate dehydrogenase, aconitase, NADP-dependent isocitrate dehydrogenase, and fumarase were higher in cells producing KGA than in cells producing citric acid.

  19. Acid-precipitation studies in Colorado and Wyoming: Interim report of surveys of Montane amphibians and water chemistry. Interim report, 1986-1988

    SciTech Connect

    Corn, P.S.; Stolzenburg, W.; Bury, R.B.

    1989-06-01

    Surveys for amphibians were conducted in the Rocky Mountains of northern Colorado and southern Wyoming from 1986 to 1988. The northern leopard frog (Rana pipiens) was present at only 12% of historically known localities, and the boreal toad (Bufo boreas) was present at 17% of known localities. Chorus frogs (Pseudacris triseriata) suffered a catastrophic decline in population size in one population monitored since 1961, but regionally, this species was observed in 64% of known localities. Tiger salamanders (Ambystoma tigrinum) and wood frogs (Rana sylvatica) were present at 45% and 69% of known localities respectively. Acid neutralizing capacity, pH, specific conductivity, and cation concentrations in water at amphibian localities were negatively correlated with elevation. Survival of wood frog embryos declined when exposed to aluminum concentrations.

  20. Simultaneous chemical oxygen demand removal, methane production and heavy metal precipitation in the biological treatment of landfill leachate using acid mine drainage as sulfate resource.

    PubMed

    Li, Yu-Long; Wang, Jin; Yue, Zheng-Bo; Tao, Wei; Yang, Hai-Bin; Zhou, Yue-Fei; Chen, Tian-Hu

    2017-03-06

    Biological treatment played an important role in the treatment of landfill leachate. In the current study, acid mine drainage (AMD) was used as a source of sulfate to strengthen the anaerobic treatment of landfill leachate. Effects of chemical oxygen demand (COD) and SO4(2-) mass concentration ratio on the decomposition of organic matter, methane production and sulfate reduction were investigated and the microbial community was analyzed using the high throughout methods. Results showed that high removal efficiency of COD, methane production and heavy metal removal was achieved when the initial COD/SO4(2-) ratio (based on mass) was set at 3.0. The relative abundance of anaerobic hydrogen-producing bacteria (Candidatus Cloacamonas) in the experimental group with the addition of AMD was significantly increased compared to the control. Abundance of hydrogenotrophic methanogens of Methanosarcina and Methanomassiliicoccus was increased. Results confirmed that AMD could be used as sulfate resource to strengthen the biological treatment of landfill leachate.

  1. Distribution, thickness, and volume of fine-grained sediment from precipitation of metals from acid-mine waters in Keswick Reservoir, Shasta County, California

    USGS Publications Warehouse

    Bruns, Terry R.; Alpers, Charles N.; Carlson, Paul

    2006-01-01

    In February 1993, the U.S. Geological Survey (USGS) acquired high-resolution seismic-reflection data to map the distribution and thickness of fine-grained sediments associated with acid-mine drainage in Keswick Reservoir on the Sacramento River, near Redding, California. In the Spring Creek Arm of Keswick Reservoir, the sediments occurred in three distinct accumulations; thicknesses are greater than 2 meters (m) in the western accumulation, greater than 5 m in the central accumulation, and up to 8 m in the eastern accumulation. In Keswick Reservoir, fine-grained sediments related to acid-mine drainage were present from slightly north of the Spring Creek Arm downstream to the Keswick Dam. Sediment thickness varies from about 3 m opposite the mouth of the Spring Creek Arm to less than 1 m near Keswick Dam. Our estimate for the total volume of fine-grained sediments in the Spring Creek Arm at the time of the geophysical survey in February 1993 is about 152,000 cubic meters in three sediment accumulations, with about 14,000, 32,000, and 105,000 cubic meters respectively in the western, central, and eastern accumulations. We interpreted that an additional 110, 000 cubic meters of material was present in the main part of Keswick Reservoir. At the time of data collection, we therefore estimate that the total volume of fine-grained sediment was 260,000 cubic meters. In the main part of Keswick Reservoir, 42% to 50% of the reservoir area contiguous to Spring Creek Arm had mappable fine-grained sediments. Decreasing sediment supply down-reservoir meant that mappable sediment covered only about 35% of the reservoir in the area to the south, decreasing to about 12% near Keswick Dam. Much of the reservoir bottom below the Spring Creek Arm could have had a thin (less than 20-30 cm) cover of fine-grained sediment that was not mappable using the seismic-reflection data.

  2. Influence of acid and alkaline sources on optical, structural and photovoltaic properties of CdSe nanoparticles precipitated from aqueous solution

    NASA Astrophysics Data System (ADS)

    Coria-Monroy, C. Selene; Sotelo-Lerma, Mérida; Hu, Hailin

    2016-06-01

    CdSe is a widely researched material for photovoltaic applications. One of the most important parameters of the synthesis is the pH value, since it determines the kinetics and the mechanism of the reaction and in consequence, the optical and morphological properties of the products. We present the synthesis of CdSe in solution with strict control of pH and the comparison of ammonia and KOH as alkaline sources and diluted HCl as acid medium. CdSe formation was monitored with photoluminescence emission spectra (main peak in 490 nm, bandgap of CdSe nanoparticles). XRD patterns indicated that CdSe nanoparticles are mainly of cubic structure for ammonia and HCl, but the hexagonal planes appear with KOH. Product yield decreases with pH and also decreases with KOH at constant pH value since ammonia has a double function, as complexing agent and alkaline source. Changes in morphology were observed in SEM images as well with the different alkaline source. The effect of alkaline sources on photovoltaic performance of hybrid organic solar cells with CdSe and poly(3-hexylthiophene) as active layers was clearly observed, indicating the importance of synthesis conditions on optoelectronic properties of promising semiconductor nanomaterials for solar cell applications.

  3. Global Climatology of Surface Precipitation: Role of TRMM and GPM

    NASA Astrophysics Data System (ADS)

    Adler, R. F.; Wang, J.; Gu, G.

    2011-12-01

    analysis will be presented, along with validation of the estimated errors from the TCC. A potential procedure to incorporate the TRMM estimates over the last 14 years into the GPCP will be described, as well as how the GPM data, especially at higher latitudes, will be valuable by themselves, and as a continuation of the TRMM information in lower latitudes. In addition, the development of TRMM Composite Monthly (TCM) and TRMM Composite Anomaly (TCA) analyses, which use a similar approach as the TCC, but with time and space disaggregation using the TRMM Multi-satellite Precipitation Analysis (TMPA/3B42) data set will be described, along with examples indicating the use of this form of mission product for a variety of climate analyses. Thoughts for use of GPM data for similar products and the special requirements for high latitudes will also be described.

  4. [Chemical characteristics of atmospheric precipitation in Shenzhen].

    PubMed

    Niu, Yu-wen; He, Ling-yan; Hu, Min

    2008-04-01

    The precipitation chemical components are good indicators of the air pollution. With rapid economic developing, air quality has greatly changed in Shenzhen. To investigate Chemical feature of precipitation and atmospheric pollution characteristics in Shenzhen, two-year precipitation samples in Shenzhen were collected and analyzed. Based on the dataset, chemical characteristics of rainwater in Shenzhen were discussed. Results show that the concentration of the sum of anions and rations in Shenzhen rainwater was lower compared to northern cities like Beijing, whereas the acidification of rainwater was very serious in Shenzhen. Volume-weighted mean pH values of rainwater were 4.48 and 4.68 respectively, and 88% and 91% of rain events were acidic in 2004 and 2005, respectively. The contribution of SO4(2-) to Shenzhen rainwater acidity was smaller than that in northern cities and NO3- and Cl- played an important part to acidification of Shenzhen precipitation. The contribution of Cl- and Na+ to rainwater chemical components was higher, indicating the significant marine influence on Shenzhen precipitation. The secondary components like SO4(2-), NO3- and NH4+ contributed significantly to total ions of rainwater and they accounted for more than 40% of total ions in 2004 and 2005, which indicated the severe secondary pollution in Shenzhen. There was the obvious difference in origins for different rainwater components. Cl-, K+ and Na+ were mainly from marine contribution while SO4(2-), NO3-, Ca2+ and Mg2+ were mainly from non-sea salt fraction. Formic acid, acetic acid and oxalic acid were most abundant low-molecular weight organic acids and the sum of their concentrations accounted for 94% and 99% of total organic acids determined in 2004 and 2005, respectively.

  5. Catalyzed precipitation in aluminum

    NASA Astrophysics Data System (ADS)

    Mitlin, David

    The work reported in Chapter 1 concerned the influence of Si on the precipitation of theta' (metastable Al2Cu) during the isothermal aging of Al-2Cu-1Si (wt. %). The binary alloys Al-2Cu and Al-1Si were studied for comparison. Only two precipitate phases were detected: pure Si in Al-Si and Al-Cu-Si, and theta' (metastable Al 2Cu) in Al-Cu and Al-Cu-Si. On aging the ternary, Si precipitates first, and provides heterogeneous sites to nucleate theta'. As a consequence, the density of theta' precipitates in Al-Cu-Si is much higher than in the binary Al-Cu. Also, the theta ' precipitates in the ternary alloy have lower aspect ratio (at given particle size) and lose coherence on their broad faces at a slower rate. The principal focus of Chapter 2 is to explain precipitation in Al-lat.%Si-lat%Ge. The microstructure is characterized using conventional and high resolution transmission electron microscopy, as well as energy dispersive X-ray spectroscopy. The first precipitates to come out of solid solution have a cube-cube orientation relationship with the matrix. High resolution TEM demonstrated that all the precipitates start out, and remain multiply twinned throughout the aging treatment. There is a variation in the stoichiometry of the precipitates, with the mean composition being Si-44.5at%Ge. It is also shown that in Al-Si-Ge it is not possible to achieve satisfactory hardness through a conventional heat treatment. This result is explained in terms of sluggish precipitation of the diamond-cubic Si-Ge phase coupled with particle coarsening. The purpose of Chapters 3 and 4 is to explain these properties in terms of the role that the Si-Ge additions have on modifying the conventional Al-Cu aging sequence. In both AlCu and AlCuSiGe the room temperature microstructure consists of both GP zones and theta″ precipitates. Upon aging at 190°C Al-Cu displays the well known precipitation sequence; the slow dissolution of GP zones and theta″ and the gradual formation of theta

  6. [Progress in microbial production of succinic acid].

    PubMed

    Liu, Rongming; Liang, Liya; Wu, Mingke; Jiang, Min

    2013-10-01

    Succinic acid is one of the key intermediates in the tricarboxylic acid cycle (TCA)and has huge potentials in biopolymer, food, medicine applications. This article reviews recent research progress in the production of succinic acid by microbial fermentation, including discovery and screening of the succinic-acid-producing microbes, the progress of genetic engineering strategy and metabolic engineering technology for construction of succinic acid-producing strains, and fermentation process control and optimization. Finally, we discussed the limitation of current progress and proposed the future research needs for microbial production of succinic acid.

  7. Acid rains over semi-urban atmosphere at eastern Himalaya and near coast of Bay of Bengal and alkaline rains over typical urban atmosphere in India: A study on precipitation chemistry during monsoon, 2013

    NASA Astrophysics Data System (ADS)

    Roy, Arindam; Chatterjee, Abhijit; Sarkar, Chirantan; Ghosh, Sanjay; Raha, Sibaji

    A study has been made on precipitation chemistry over three different atmosphere in India. Rain samples were collected during the entire period of monsoon (June-October) in the year of 2013 over Kolkata (22.6 (°) N, 89.4 (°) E), a mega city with typical urban atmosphere; Falta (22.3 (°) N, 88.1 (°) E), a rural atmosphere near eastern coast of Bay of Bengal and Darjeeling (27.01 (°) N, 88.15 (°) E), a high altitude (2200 m asl)hill station over eastern Himalaya in India. The major focus of the study is to investigate the composition of various types of aerosol ionic components scavenged and its effect on the acidity and how it differs between these three distinctly different atmospheres. The results showed that the sea-salt components were higher in Falta (140 mueqv/lit) followed by Kolkata (120 mueqv/lit) and minimum in Darjeeling (30 mueqv/lit). Over all the stations, Na (+) and Cl (-) showed strong correlations indicating common marine source. The marine air masses originated from Bay of Bengal (BoB) were found to significantly enrich sea-salt particles over Falta, the nearest station from BoB and having least effect on Darjeeling, the farthest station from BoB. Dust and anthropogenic aerosols particles were significantly higher over Kolkata compared to other two stations. Dust particles were found to scavenge more in the initial phase of monsoon and it gradually decreased as the monsoon progressed. The average pH of rain water over Kolkata was 6.0 indicating alkaline in nature. pH over Falta was 5.2 indicating slightly acidic in nature and the most important fact is that pH over Darjeeling was 4.6 indicating highly acidic in nature. It was found that Ca (2+) , Mg (2+) and NH _{4} (+) neutralized the acidity of rain water over all the stations with the maximum neutralizing factor for Ca (2+) . However, NH _{4} (+) played important role over Darjeeling in neutralizing rain water acidity. The major reason for high acidity of rain water was not due to high

  8. The effect of preincubation of seed crystals of uric acid and monosodium urate with undiluted human urine to induce precipitation of calcium oxalate in vitro : implications for urinary stone formation.

    PubMed Central

    Grover, Phulwinder K.; Ryall, Rosemary L.

    2002-01-01

    BACKGROUND: Previous studies demonstrated that crystals of uric acid (UA) and sodium urate (NaU) can induce the precipitation of calcium oxalate (CaOx) from its inorganic metastable solutions, but similar effects have not been unequivocally shown to occur in urine. The aim of this investigation was to determine whether preincubation of these seeds with urine alter their ability to induce deposition of CaOx from solution and thus provide a possible explanation for discrepancy of results obtained from aqueous inorganic solutions and undiluted urine. MATERIALS AND METHODS: The effects of commercial seed crystals of UA, NaU and CaOx (6 mg/100 ml) on CaOx crystallization were compared in a solution with the same crystals that had been preincubated for 3 hours with healthy male urine. A Coulter Counter was used to follow the crystallization and decrease in soluble (14) C-oxalate was measured to determine the deposition of CaOx. The precipitated particles were examined by scanning electron microscopy (SEM). The preincubated seeds were demineralized and proteins released were analyzed by sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: Analysis of (14) C-oxalate data revealed that while treated UA seeds did not affect CaOx deposition, those of NaU and CaOx inhibited the process by 51.9 (p<0.05) and 8.5% (p<0.05) relative to their respective untreated counterparts. Particle size analysis showed that the average modal sizes of particles precipitated in the presence of treated seed crystals of UA, NaU, and CaOx were very similar to those deposited in the presence of their respective untreated controls. These findings were confirmed by SEM which also showed that seed crystals of UA and NaU, untreated and treated, were attached like barnacles upon the surfaces of CaOx crystals which themselves were bigger than those precipitated in the presence of CaOx seeds. SDS-PAGE analysis of the demineralized treated seeds showed that they all selectively

  9. Precipitation chemistry in central Amazonia

    NASA Technical Reports Server (NTRS)

    Andreae, M. O.; Talbot, R. W.; Berresheim, H.; Beecher, K. M.

    1990-01-01

    Rain samples from three sites in central Amazonia were collected over a period of 6 weeks during the 1987 wet season and analyzed for ionic species and dissolved organic carbon. A continuous record of precipitation chemistry and amount was obtained at two of these sites, which were free from local or regional pollution, for a time period of over 1 month. The volume-weighted mean concentrations of most species were found to be about a factor of 5 lower during the wet season compared with previous results from the dry season. Only sodium, potassium, and chloride showed similar concentrations in both seasons. When the seasonal difference in rainfall amount is taken into consideration, the deposition fluxes are only slightly lower for most species during the wet season than during the dry season, again with the exception of chloride, potassium, and sodium. Sodium and chloride are present in the same ratio as in sea salt; rapid advection of air masses of marine origin to the central Amazon Basin during the wet season may be responsible for the observed higher deposition flux of these species. Statistical analysis suggests that sulfate is, to a large extent, of marine (sea salt and biogenic) origin, but that long-range transport of combustion-derived aerosols also makes a significant contribution to sulfate and nitrate levels in Amazonian rain. Organic acid concentrations in rain were responsible for a large fraction of the observed precipitation acidity; their concentration was strongly influenced by gas/liquid interactions.

  10. IMERG Global Precipitation Rates

    NASA Video Gallery

    NASA's Global Precipitation Measurement mission has produced its first global map of rainfall and snowfall. The GPM Core Observatory launched one year ago on Feb. 27, 2014 as a collaboration betwee...

  11. My NASA Data Precipitation

    NASA Video Gallery

    This lesson has two activities that help students develop a basic understanding of the relationship between cloud type and the form of precipitation and the relationship between the amount of water...

  12. Precipitation Estimates for Hydroelectricity

    NASA Technical Reports Server (NTRS)

    Tapiador, Francisco J.; Hou, Arthur Y.; de Castro, Manuel; Checa, Ramiro; Cuartero, Fernando; Barros, Ana P.

    2011-01-01

    Hydroelectric plants require precise and timely estimates of rain, snow and other hydrometeors for operations. However, it is far from being a trivial task to measure and predict precipitation. This paper presents the linkages between precipitation science and hydroelectricity, and in doing so it provides insight into current research directions that are relevant for this renewable energy. Methods described include radars, disdrometers, satellites and numerical models. Two recent advances that have the potential of being highly beneficial for hydropower operations are featured: the Global Precipitation Measuring (GPM) mission, which represents an important leap forward in precipitation observations from space, and high performance computing (HPC) and grid technology, that allows building ensembles of numerical weather and climate models.

  13. Chemisorption And Precipitation Reactions

    EPA Science Inventory

    The transport and bioavailability of chemical components within soils is, in part, controlled by partitioning between solids and solution. General terms used to describe these partitioning reactions include chemisorption and precipitation. Chemisorption is inclusive of the suit...

  14. Genome-wide screen identifies Escherichia coli TCA cycle-related mutants with extended chronological lifespan dependent on acetate metabolism and the hypoxia-inducible transcription factor ArcA

    PubMed Central

    Gonidakis, Stavros; Finkel, Steven E.; Longo, Valter D.

    2010-01-01

    Summary Single-gene mutants with extended lifespan have been described in several model organisms. We performed a genome-wide screen for long-lived mutants in Escherichia coli which revealed strains lacking TCA cycle-related genes that exhibit longer stationary phase survival and increased resistance to heat stress compared to wild-type. Extended lifespan in the sdhA mutant, lacking subunit A of succinate dehydrogenase, is associated with reduced production of superoxide and increased stress resistance. On the other hand, the longer lifespan of the lipoic acid synthase mutant (lipA) is associated with reduced oxygen consumption and requires the acetate-producing enzyme pyruvate oxidase, as well as acetyl-CoA synthetase, the enzyme that converts extracellular acetate to acetyl-CoA. The hypoxia-inducible transcription factor ArcA, acting independently of acetate metabolism, is also required for maximum lifespan extension in the lipA and lpdA mutants, indicating that these mutations promote entry into a mode normally associated with a low-oxygen environment. Since analogous changes from respiration to fermentation have been observed in long-lived Saccharomyces cerevisiae and Caenorhabditis elegans strains, such metabolic alterations may represent an evolutionarily conserved strategy to extend lifespan. PMID:20707865

  15. Severe ulceration with impaired induction of growth factors and cytokines in keratinocytes after trichloroacetic acid application on TRPV1-deficient mice.

    PubMed

    Li, Hong-jin; Kanazawa, Nobuo; Kimura, Ayako; Kaminaka, Chikako; Yonei, Nozomi; Yamamoto, Yuki; Furukawa, Fukumi

    2012-01-01

    Transient receptor potential vanilloid 1 (TRPV1) is a highly polymodal TRP channel activated by various stimuli, including capsaicin, heat and acids. TRPV1 expression can be detected widely but is highest in sensory neurons and its activation alerts the body to noxious signals via neurogenic pain. Although TRPV1 is reportedly localized in the epidermis, it remains unclear how TRPV1 is involved in the chemical peeling processes with cytotoxic acids. Therefore, in this study, the role of TRPV1 on the effects of trichloroacetic acid (TCA) peeling was assessed using TRPV1-deficient mice. Following the confirmation of TRPV1 expression in murine keratinocytes with reverse transcription-polymerase chain reaction and immunohistochemistry, the effects of TCA on TRPV1-deficient mouse skin were compared with those on wild-type mouse skin. Our results indicated that TRPV1 expression was not required for TCA-induced DNA damage, as shown by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling, but was indispensable for the TCA-induced production of distinct growth factors and cytokines by keratinocytes. Ulceration after TCA peeling was actually more severe in the absence of TRPV1, suggesting that the TRPV1-mediated epidermal production of growth factors and cytokines affected the damaging and healing processes of TCA-peeled skin to induce rejuvenation.

  16. Extraction and Separation of Vitisin D, Ampelopsin B and cis-Vitisin A from Iris lactea Pall. var. chinensis (Fisch.) Koidz by Alkaline Extraction-Acid Precipitation and High-Speed Counter-Current Chromatography.

    PubMed

    Lv, Huanhuan; Zhou, Wenna; Wang, Xiaoyan; Wang, Zhenhua; Suo, Yourui; Wang, Honglun

    2016-01-01

    Naturally occurring oligostilbenes are receiving more attention because they exhibit several beneficial effects for health, including hepatoprotective, antitumor, anti-adipogenic, antioxidant, antiaging, anti-inflammatory, anti-microbial, antiviral, immunosuppressive and neuroprotective activities. Thus, they could be of some potentially therapeutic values for several diseases. In this study, we adopted the alkaline extraction-acid precipitation (AEAP) method for extraction of oligostilbenes from the seed kernel of Iris lactea Then, the high-speed counter-current chromatography (HSCCC) was used for preparative isolation and purification of oligostilbenes from the AEAP extracts. Finally, three oligostilbenes, namely vitisin D (73 mg), ampelopsin B (25 mg) and cis-vitisin A (16 mg), were successfully fractionated by HSCCC with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (2:5:3:6, v/v/v/v) from 300 mg of the AEAP extracts in ∼ 190 min. The purities of the three isolated oligostilbenes were all over 95.0% as analyzed by high performance liquid chromatography. They all were isolated from I. lacteal for the first time.The method of AEAP for the preparation of the oligostilbene-enriched crude sample was simple, and the HSCCC technique for the isolation and purification of oligostilbenes was efficient.

  17. The Majority of Free-Living Autotrophic Bacteria use the Reductive TCA Cycle for Carbon Fixation at Deep-Sea Hydrothermal Vents

    NASA Astrophysics Data System (ADS)

    Campbell, B. J.; Cary, C.

    2003-12-01

    Deep-sea hydrothermal vents support large micro and macroscopic communities, without the input of photosynthesis. Autotrophic production at these vents is based on hydrothermal vent fluid chemistry. Primary production has been thought to occur mainly via hydrogen sulfide oxidation through the Calvin-Benson pathway, as measured by the presence of Rubisco in endosymbionts of several invertebrate hosts. Recently, we characterized two fosmids from a large insert library of the epsilon Proteobacterial episymbionts of Alvinella pompejana. Both contained sequences encoding ATP citrate lyase, a key enzyme in the reverse TCA cycle, an alternate carbon dioxide fixation pathway. Previous investigators have demonstrated the dominance of the epsilon subdivision in the free-living bacterial communities at hydrothermal vents. Based on these results, our working hypothesis is: The rTCA cycle is the dominant pathway for carbon fixation in the free-living bacterial communities at hydrothermal vents. A selection of free-living bacterial communities from various geographic locations (9N, East Pacific Rise and Guaymas Basin) were screened for the presence, diversity and expression (via RT-PCR) of Rubisco (forms I and II) and ATP citrate lyase. Our results indicate that the ATP citrate lyase gene is diverse and is consistently expressed in several types of vent communities. The two forms of Rubisco are not consistently present or expressed in the same environments. These results indicate that chemoautotrophic production in the free-living bacterial communities at deep-sea hydrothermal vents is dominated by bacteria that utilize the rTCA cycle, and parallels the phylogenetic dominance of members of the epsilon subdivision of Proteobacteria.

  18. Data Corrections and Wind-Tunnel Data Comparisons of a 5% TCA Model in the NASA Ames 12-ft Pressure Tunnel

    NASA Technical Reports Server (NTRS)

    Zuniga, Fanny A.

    1999-01-01

    The objectives of this research are: 1) To determine the effect of geometric variations near the inboard leading-edge flap on high-lift and stability and control performance data; 2) To determine Re effects on TCA (Technology Concept Aircraft) high-lift configuration for optimum high-lift and stability and control performance at takeoff, climbout, approach and landing conditions; and 3) To obtain flow-visualization data on upper surface of wing for CFD validations. This paper is presented in viewgraph form.

  19. Understanding Acid Rain

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  20. Comparison of efficacy of chemical peeling with 25% trichloroacetic acid and 0.1% retinoic acid for facial rejuvenation

    PubMed Central

    Gurel, Mehmet Salih; Gungor, Sule; Tekeli, Omur; Canat, Dilek

    2016-01-01

    Introduction Skin aging is a problem which negatively affects the psyche of the person, social relations, as well as work life and health and which compels the patients to find appropriate treatment methods. Numerous treatment methods have been developed in order to delay aging and to reduce the aging effects in addition to having a younger, healthier and more beautiful facial appearance. Aim To compare the efficiency, cosmetic results and possible adverse effects of the peeling treatment with 25% trichloroacetic acid (TCA) and 0.1% retinoic acid for facial rejuvenation in patients presenting with skin aging. Material and methods Fifty female patients in total presenting with medium and advanced degree skin aging were subject to this study. Two separate treatment groups were formed; the first group underwent chemical skin treatment with 25% TCA while the other group was applied with 0.1% retinoic acid treatment. Following the 4 months’ treatment the patients were controlled three times in total for post lesional hypopigmentation, hyperpigmentation, scars, skin irritation and other possible changes per month. The pretreatment and first follow-up visit, and final control images were comparatively evaluated by three observers via specific software. Results The healing rates of the group subject to retinoic acid were statistically higher (p < 0.05) compared to patients in the TCA group in the final follow-up visit following the treatment according to the first and second observers. On the other hand, according to the third observer, patients applied with retinoic acid presented with higher healing rates compared to those treated with TCA, however; this rate was not statistically significant (p > 0.05). The frequency of TCA- and retinoic acid-associated adverse effects was similar in both groups (p > 0.05). As a result of both treatments, a reduction in the quality of life scores as well as a pronounced recovery (p = 0.001) in the quality of life of those patients

  1. A STUDY COMPARING CHEMICAL PEELING USING MODIFIED JESSNER'S SOLUTION AND 15%TRICHLOROACETIC ACID VERSUS 15% TRICHLOROACETIC ACID IN THE TREATMENT OF MELASMA

    PubMed Central

    Safoury, Omar Soliman; Zaki, Nagla Mohamed; El Nabarawy, Eman Ahmad; Farag, Eman Abas

    2009-01-01

    Background: Melasma is a symmetric progressive hyperpigmentation of the facial skin that occurs in all races but has a predilection for darker skin phenotypes. Depigmenting agents, laser and chemical peeling as classic Jessner's solution, modified Jessner's solution and trichloroacetic acid have been used alone and in combination in the treatment of melasma. Objectives: The aim of the study was to compare the therapeutic effect of combined 15% Trichloroacetic acid (TCA) and modified Jessner's solution with 15% TCA on melasma. Materials and Methods: Twenty married females with melasma (epidermal type), with a mean age of 38.25 years, were included in this study. All were of skin type III or IV. Fifteen percent TCA was applied to the whole face, with the exception of the left malar area to which combined TCA 15% and modified Jessner's solution was applied. Results: Our results revealed statistically highly significant difference between MASI Score (Melasma Area and Severity Index) between the right malar area and the left malar area. Conclusion: Modified Jessner's solution proved to be useful as an adjuvant treatment with TCA in the treatment of melasma, improving the results and minimizing postinflammatory hyperpigmentation. PMID:20049268

  2. Centrifugal precipitation chromatography.

    PubMed

    Ito, Yoichiro; Qi, Lin

    2010-01-15

    Centrifugal precipitation chromatography separates analytes according their solubility in ammonium sulfate (AS) solution and other precipitants. The separation column is made from a pair of long spiral channels partitioned with a semipermeable membrane. In a typical separation, concentrated ammonium sulfate is eluted through one channel while water is eluted through the other channel in the opposite direction. This countercurrent process forms an exponential AS concentration gradient through the water channel. Consequently, protein samples injected into the water channel is subjected to a steadily increasing AS concentration and at the critical AS concentration they are precipitated and deposited in the channel bed by the centrifugal force. Then the chromatographic separation is started by gradually reducing the AS concentration in the AS channel which lowers the AS gradient concentration in the water channel. This results in dissolution of deposited proteins which are again precipitated at an advanced critical point as they move through the channel. Consequently, proteins repeat precipitation and dissolution through a long channel and finally eluted out from the column in the order of their solubility in the AS solution. The present method has been successfully applied to a number of analytes including human serum proteins, recombinant ketosteroid isomerase, carotenoid cleavage enzymes, plasmid DNA, polysaccharide, polymerized pigments, PEG-protein conjugates, etc. The method is capable to single out the target species of proteins by affinity ligand or immunoaffinity separation.

  3. Lipotoxicity in steatohepatitis occurs despite an increase in tricarboxylic acid cycle activity

    PubMed Central

    Patterson, Rainey E.; Kalavalapalli, Srilaxmi; Williams, Caroline M.; Nautiyal, Manisha; Mathew, Justin T.; Martinez, Janie; Reinhard, Mary K.; McDougall, Danielle J.; Rocca, James R.; Yost, Richard A.; Cusi, Kenneth; Garrett, Timothy J.

    2016-01-01

    The hepatic tricarboxylic acid (TCA) cycle is central to integrating macronutrient metabolism and is closely coupled to cellular respiration, free radical generation, and inflammation. Oxidative flux through the TCA cycle is induced during hepatic insulin resistance, in mice and humans with simple steatosis, reflecting early compensatory remodeling of mitochondrial energetics. We hypothesized that progressive severity of hepatic insulin resistance and the onset of nonalcoholic steatohepatitis (NASH) would impair oxidative flux through the hepatic TCA cycle. Mice (C57/BL6) were fed a high-trans-fat high-fructose diet (TFD) for 8 wk to induce simple steatosis and NASH by 24 wk. In vivo fasting hepatic mitochondrial fluxes were determined by 13C-nuclear magnetic resonance (NMR)-based isotopomer analysis. Hepatic metabolic intermediates were quantified using mass spectrometry-based targeted metabolomics. Hepatic triglyceride accumulation and insulin resistance preceded alterations in mitochondrial metabolism, since TCA cycle fluxes remained normal during simple steatosis. However, mice with NASH had a twofold induction (P < 0.05) of mitochondrial fluxes (μmol/min) through the TCA cycle (2.6 ± 0.5 vs. 5.4 ± 0.6), anaplerosis (9.1 ± 1.2 vs. 16.9 ± 2.2), and pyruvate cycling (4.9 ± 1.0 vs. 11.1 ± 1.9) compared with their age-matched controls. Induction of the TCA cycle activity during NASH was concurrent with blunted ketogenesis and accumulation of hepatic diacylglycerols (DAGs), ceramides (Cer), and long-chain acylcarnitines, suggesting inefficient oxidation and disposal of excess free fatty acids (FFA). Sustained induction of mitochondrial TCA cycle failed to prevent accretion of “lipotoxic” metabolites in the liver and could hasten inflammation and the metabolic transition to NASH. PMID:26814015

  4. Lipotoxicity in steatohepatitis occurs despite an increase in tricarboxylic acid cycle activity.

    PubMed

    Patterson, Rainey E; Kalavalapalli, Srilaxmi; Williams, Caroline M; Nautiyal, Manisha; Mathew, Justin T; Martinez, Janie; Reinhard, Mary K; McDougall, Danielle J; Rocca, James R; Yost, Richard A; Cusi, Kenneth; Garrett, Timothy J; Sunny, Nishanth E

    2016-04-01

    The hepatic tricarboxylic acid (TCA) cycle is central to integrating macronutrient metabolism and is closely coupled to cellular respiration, free radical generation, and inflammation. Oxidative flux through the TCA cycle is induced during hepatic insulin resistance, in mice and humans with simple steatosis, reflecting early compensatory remodeling of mitochondrial energetics. We hypothesized that progressive severity of hepatic insulin resistance and the onset of nonalcoholic steatohepatitis (NASH) would impair oxidative flux through the hepatic TCA cycle. Mice (C57/BL6) were fed a high-trans-fat high-fructose diet (TFD) for 8 wk to induce simple steatosis and NASH by 24 wk. In vivo fasting hepatic mitochondrial fluxes were determined by(13)C-nuclear magnetic resonance (NMR)-based isotopomer analysis. Hepatic metabolic intermediates were quantified using mass spectrometry-based targeted metabolomics. Hepatic triglyceride accumulation and insulin resistance preceded alterations in mitochondrial metabolism, since TCA cycle fluxes remained normal during simple steatosis. However, mice with NASH had a twofold induction (P< 0.05) of mitochondrial fluxes (μmol/min) through the TCA cycle (2.6 ± 0.5 vs. 5.4 ± 0.6), anaplerosis (9.1 ± 1.2 vs. 16.9 ± 2.2), and pyruvate cycling (4.9 ± 1.0 vs. 11.1 ± 1.9) compared with their age-matched controls. Induction of the TCA cycle activity during NASH was concurrent with blunted ketogenesis and accumulation of hepatic diacylglycerols (DAGs), ceramides (Cer), and long-chain acylcarnitines, suggesting inefficient oxidation and disposal of excess free fatty acids (FFA). Sustained induction of mitochondrial TCA cycle failed to prevent accretion of "lipotoxic" metabolites in the liver and could hasten inflammation and the metabolic transition to NASH.

  5. Bile acids alter the subcellular localization of CNT2 (concentrative nucleoside cotransporter) and increase CNT2-related transport activity in liver parenchymal cells

    PubMed Central

    Fernández-Veledo, Sonia; Huber-Ruano, Isabel; Aymerich, Ivette; Duflot, Sylvie; Casado, F. Javier; Pastor-Anglada, Marçal

    2006-01-01

    CNT2 (concentrative nucleoside cotransporter) is a plasma membrane high-affinity Na+-coupled adenosine transporter, also localized in intracellular structures. This transporter protein may play additional roles other than nucleoside salvage, since it has recently been shown to be under purinergic control via KATP channels, by a mechanism that does not seem to involve changes in its subcellular localization. In an attempt to identify the agents that promote CNT2 trafficking, bile acids were found to increase CNT2-related transport activity in a KATP channel-independent manner in both Fao hepatoma and rat liver parenchymal cells. A maximum effect was recorded after treatment with hydrophilic anions such as TCA (taurocholate). However, this effect did not involve changes in the amount of CNT2 protein, it was instead associated with a subcellular redistribution of CNT2, resulting in an accumulation of the transporter at the plasma membrane. This was deduced from subcellular fractionation studies, biotinylation of plasma membrane proteins and subsequent CNT2 detection in streptavidin precipitates and in vivo confocal microscopic analysis of the distribution of a YFP (yellow fluorescent protein)–CNT2 construct. The induction of CNT2 translocation, triggered by TCA, was inhibited by wortmannin, dibutyryl-AMPc, PD98059 and colchicine, thus suggesting the involvement of the PI3K/ERK (phosphoinositide 3-kinase/extracellular-signal related kinase) pathway in microtubule-dependent activation of recombinant CNT2. These are novel effects of bile-acid physiology and provide the first evidence for short-term regulation of CNT2 translocation into and from the plasma membrane. PMID:16390326

  6. FORMATION OF URANIUM PRECIPITATES

    DOEpatents

    Googin, J.M. Jr.

    1959-03-17

    A method is described for precipitation of uranium peroxide from uranium- containing solutions so as to obtain larger aggregates which facilitates washings decantations filtrations centrifugations and the like. The desired larger aggregate form is obtained by maintaining the pH of the solution in the approximate range of 1 to 3 and the temperature at about 25 deg C or below while carrytng out the precipitation. Then prior to removal of the precipitate a surface active sulfonated bicarboxyacids such as di-octyl sodium sulfo-succinates is incorporated in an anount of the order of 0.01 to 0.05 percent by weights and the slurry is allowed to ripen for about one-half hour at a temperatare below 10 deg C.

  7. Surface plasmon resonance based fiber optic trichloroacetic acid sensor utilizing layer of silver nanoparticles and chitosan doped hydrogel.

    PubMed

    Semwal, Vivek; Shrivastav, Anand M; Gupta, Banshi D

    2017-02-10

    In this study, we report a silver nanoparticles/chitosan doped hydrogel-based fiber optic sensor for the detection of trichloroacetic acid (TCA). The sensor is based on the combined phenomenon of localized and propagating surface plasmons. The sensing relies on the interaction of TCA with silver nanoparticles (AgNP) which results in the electron transfer between the negative group of TCA and positive amino group of AgNP stabilizer (chitosan). This alters the mechanical properties/refractive index of the AgNP embedded hydrogel matrix as well as the refractive index of the AgNP. The change in refractive index of both in turn changes the effective refractive index of the nanocomposite hydrogel layer which can be determined using the Maxwell-Garnet Theory. Four stage optimization of the probe fabrication parameters is performed to obtain the best performance of the sensing probe. The sensor operates in the TCA concentration range 0-120 μm which is harmful for the humans and environment. The shift in peak extinction wavelength observed for the same TCA concentration range is 42 nm. The sensor has the linearity range for the TCA concentration range of 40-100 μm. The sensor possesses high sensitivity, selectivity and numerous other advantages such as ease of handling, quick response, modest cost and capability of online monitoring and remote sensing.

  8. Surface plasmon resonance based fiber optic trichloroacetic acid sensor utilizing layer of silver nanoparticles and chitosan doped hydrogel

    NASA Astrophysics Data System (ADS)

    Semwal, Vivek; Shrivastav, Anand M.; Gupta, Banshi D.

    2017-02-01

    In this study, we report a silver nanoparticles/chitosan doped hydrogel-based fiber optic sensor for the detection of trichloroacetic acid (TCA). The sensor is based on the combined phenomenon of localized and propagating surface plasmons. The sensing relies on the interaction of TCA with silver nanoparticles (AgNP) which results in the electron transfer between the negative group of TCA and positive amino group of AgNP stabilizer (chitosan). This alters the mechanical properties/refractive index of the AgNP embedded hydrogel matrix as well as the refractive index of the AgNP. The change in refractive index of both in turn changes the effective refractive index of the nanocomposite hydrogel layer which can be determined using the Maxwell-Garnet Theory. Four stage optimization of the probe fabrication parameters is performed to obtain the best performance of the sensing probe. The sensor operates in the TCA concentration range 0-120 μm which is harmful for the humans and environment. The shift in peak extinction wavelength observed for the same TCA concentration range is 42 nm. The sensor has the linearity range for the TCA concentration range of 40-100 μm. The sensor possesses high sensitivity, selectivity and numerous other advantages such as ease of handling, quick response, modest cost and capability of online monitoring and remote sensing.

  9. Precipitation-Regulated Feedback

    NASA Astrophysics Data System (ADS)

    Voit, Mark

    2016-07-01

    Star formation in the central galaxies of galaxy clusters appears to be fueled by precipitation of cold clouds out of hot circumgalactic gas via thermal instability. I will present both observational and theoretical support for the precipitation mode in large galaxies and discuss how it can be implemented in cosmological simulations of galaxy evolution. Galaxy cluster cores are unique laboratories for studying the astrophysics of thermal instability and may be teaching us valuable lessons about how feedback works in galaxies spanning the entire mass spectrum.

  10. The antidiabetic drug metformin decreases mitochondrial respiration and tricarboxylic acid cycle activity in cultured primary rat astrocytes.

    PubMed

    Hohnholt, Michaela C; Blumrich, Eva-Maria; Waagepetersen, Helle S; Dringen, Ralf

    2017-03-19

    Metformin is an antidiabetic drug that is used daily by millions of patients worldwide. Metformin is able to cross the blood-brain barrier and has recently been shown to increase glucose consumption and lactate release in cultured astrocytes. However, potential effects of metformin on mitochondrial tricarboxylic acid (TCA) cycle metabolism in astrocytes are unknown. We investigated this by mapping (13) C labeling in TCA cycle intermediates and corresponding amino acids after incubation of primary rat astrocytes with [U-(13) C]glucose. The presence of metformin did not compromise the viability of cultured astrocytes during 4 hr of incubation, but almost doubled cellular glucose consumption and lactate release. Compared with control cells, the presence of metformin dramatically lowered the molecular (13) C carbon labeling (MCL) of the cellular TCA cycle intermediates citrate, α-ketoglutarate, succinate, fumarate, and malate, as well as the MCL of the TCA cycle intermediate-derived amino acids glutamate, glutamine, and aspartate. In addition to the total molecular (13) C labeling, analysis of the individual isotopomers of TCA cycle intermediates confirmed a severe decline in labeling and a significant lowering in TCA cycling ratio in metformin-treated astrocytes. Finally, the oxygen consumption of mitochondria isolated from metformin-treated astrocytes was drastically reduced in the presence of complex I substrates, but not of complex II substrates. These data demonstrate that exposure to metformin strongly impairs complex I-mediated mitochondrial respiration in astrocytes, which is likely to cause the observed decrease in labeling of mitochondrial TCA cycle intermediates and the stimulation of glycolytic lactate production. © 2017 Wiley Periodicals, Inc.

  11. The Global Precipitation Mission

    NASA Technical Reports Server (NTRS)

    Braun, Scott; Kummerow, Christian

    2000-01-01

    The Global Precipitation Mission (GPM), expected to begin around 2006, is a follow-up to the Tropical Rainfall Measuring Mission (TRMM). Unlike TRMM, which primarily samples the tropics, GPM will sample both the tropics and mid-latitudes. The primary, or core, satellite will be a single, enhanced TRMM satellite that can quantify the 3-D spatial distributions of precipitation and its associated latent heat release. The core satellite will be complemented by a constellation of very small and inexpensive drones with passive microwave instruments that will sample the rainfall with sufficient frequency to be not only of climate interest, but also have local, short-term impacts by providing global rainfall coverage at approx. 3 h intervals. The data is expected to have substantial impact upon quantitative precipitation estimation/forecasting and data assimilation into global and mesoscale numerical models. Based upon previous studies of rainfall data assimilation, GPM is expected to lead to significant improvements in forecasts of extratropical and tropical cyclones. For example, GPM rainfall data can provide improved initialization of frontal systems over the Pacific and Atlantic Oceans. The purpose of this talk is to provide information about GPM to the USWRP (U.S. Weather Research Program) community and to discuss impacts on quantitative precipitation estimation/forecasting and data assimilation.

  12. Total Precipitable Water

    SciTech Connect

    2012-01-01

    The simulation was performed on 64K cores of Intrepid, running at 0.25 simulated-years-per-day and taking 25 million core-hours. This is the first simulation using both the CAM5 physics and the highly scalable spectral element dynamical core. The animation of Total Precipitable Water clearly shows hurricanes developing in the Atlantic and Pacific.

  13. Precipitation of phenyl and phenoxypenicillin from solutions using ammonium sulfate.

    PubMed

    Luengo, J M

    1985-09-01

    An easy, rapid, and available method for separating 6-aminopenicillanic acid (6-APA), benzylpenicillin (penicillin G), and other related molecules from aqueous solutions or complex industrial broths is described. A high concentration of ammonium sulphate induces partially or totally the precipitation of the penicillin present in the solutions, while 6-APA, phenylacetic, and phenoxyacetic acid always remain in the supernatant. The filtration through No. 4 Pyrex glass-fiber filter or Whatman 3MM paper permits the separation of the compounds present in the supernatant from the other ones precipitated. The precipitated product was identified, in all cases, as ammonium penicillin. This method is described here for the first time.

  14. Influence of trichloroacetic acid peeling on the skin stress response system.

    PubMed

    Kimura, Ayako; Kanazawa, Nobuo; Li, Hong-Jin; Yonei, Nozomi; Yamamoto, Yuki; Furukawa, Fukumi

    2011-08-01

    Although trichloroacetic acid (TCA) peeling is widely applied for cosmetic treatment of photodamaged skin, the entire biological mechanisms have yet to be determined. The skin stress response system (SSRS) involves corticotropin-releasing hormone (CRH) and proopiomelanocortin (POMC) products that are locally-generated in response to locally-provided stressors or pro-inflammatory cytokines. This system would restrict tissue damage and restore local homeostasis. To determine the influence of TCA peeling on the SSRS in vitro and in vivo, expressions of POMC, melanocortin receptor 1 (MC1R), CRH and CRH receptor 1 (CRHR1) mRNA were examined by reverse transcription polymerase chain reaction in Pam212 murine keratinocytes, murine plantar and healthy human abdominal skin specimens after TCA treatment. In addition, their protein expressions as well as those of POMC-derived peptides were examined immunohistochemically. After TCA treatment, transient upregulation of POMC and MC1R mRNA expressions was observed in both murine and human skin, as well as in Pam212. Enhanced POMC protein, recovery of once-impaired MC1R protein, and no enhancement of POMC-derived peptide productions were revealed immunohistochemically in both murine and human epidermis. In contrast, neither expression levels of CRH and CRHR1 mRNA nor epidermal protein were enhanced after TCA application in murine and human skin, except for induction of human CRH mRNA expression. These results suggest that TCA activates the SSRS by inducing POMC and MC1R productions of keratinocytes in the CRH-independent manner, and that the biological effects of POMC itself are responsible for the TCA-induced epidermal SSRS activation.

  15. Inhibition of histone deacetylases by trans-cinnamic acid and its antitumor effect against colon cancer xenografts in athymic mice

    PubMed Central

    ZHU, BINGYAN; SHANG, BOYANG; LI, YI; ZHEN, YONGSU

    2016-01-01

    Previous studies have shown that trans-cinnamic acid (tCA) has a broad spectrum of biological activities, and exhibits antioxidant, anti-inflammatory and anticancer properties. In addition, tCA and a variety of its analogs have been detected as gut microbe-derived metabolites exerting various biological effects in the colon. The aim of this study was to assess the antitumor activity of tCA in vitro and in vivo, in particular its therapeutic efficacy against colon cancer xenografts in athymic mice. Furthermore, it aimed to examine the effects of tCA on histone deacetylases (HDACs) and to identify the underlying molecular mechanisms. Using an MTT assay, tCA was observed to inhibit the proliferation of several cancer cell lines, and the half maximal inhibitory concentration (IC50) in HT29 colon carcinoma cells was ~1 mM. Western blot analysis demonstrated that tCA upregulated the expression of acetyl-H3 and acetyl-H4 proteins, which was consistent with the effects of the HDAC inhibitor, trichostatin A (TSA). Furthermore, expression of Bcl-2 (a marker of cell proliferation) was reduced, and apoptosis was induced. Apoptosis was shown by the activation of cleavage of poly ADP ribose polymerase and the increased expression of Bax. Apoptosis was also confirmed using APC Annexin V and SYTOX Green Nucleic Acid Stain. In addition, the tCA-induced inhibition of the expression of HDAC markers and activation of apoptosis in tumor tissues were further confirmed by immunohistochemistry. Intragastric administration of tCA at doses of 1.0 and 1.5 mmol/kg body weight suppressed the growth of HT29 human colon carcinoma xenografts in athymic mice at well-tolerated doses. No toxic changes were found in the heart, lung, liver, kidney, colon or bone marrow following histopathological examination. This study indicated that tCA is effective against colon cancer xenograft in nude mice. The antitumor mechanism of tCA was mediated, at least in part, by inhibition of HDACs in cancer cells. As

  16. Precipitation hardening austenitic superalloys

    DOEpatents

    Korenko, Michael K.

    1985-01-01

    Precipitation hardening, austenitic type superalloys are described. These alloys contain 0.5 to 1.5 weight percent silicon in combination with about 0.05 to 0.5 weight percent of a post irradiation ductility enhancing agent selected from the group of hafnium, yttrium, lanthanum and scandium, alone or in combination with each other. In addition, when hafnium or yttrium are selected, reductions in irradiation induced swelling have been noted.

  17. Uncertainties in Arctic Precipitation

    NASA Astrophysics Data System (ADS)

    Majhi, I.; Alexeev, V. A.; Cherry, J. E.; Cohen, J. L.; Groisman, P. Y.

    2012-12-01

    Arctic precipitation is riddled with measurement biases; to address the problem is imperative. Our study focuses on comparison of various datasets and analyzing their biases for the region of Siberia and caution that is needed when using them. Five sources of data were used ranging from NOAA's product (RAW, Bogdanova's correction), Yang's correction technique and two reanalysis products (ERA-Interim and NCEP). The reanalysis dataset performed better for some months in comparison to Yang's product, which tends to overestimate precipitation, and the raw dataset, which tends to underestimate. The sources of bias vary from topography, to wind, to missing data .The final three products chosen show higher biases during the winter and spring season. Emphasis on equations which incorporate blizzards, blowing snow and higher wind speed is necessary for regions which are influenced by any or all of these factors; Bogdanova's correction technique is the most robust of all the datasets analyzed and gives the most reasonable results. One of our future goals is to analyze the impact of precipitation uncertainties on water budget analysis for the Siberian Rivers.

  18. Suppression of mitochondrial oxidative phosphorylation and TCA enzymes in discrete brain regions of mice exposed to high fluoride: amelioration by Panax ginseng (Ginseng) and Lagerstroemia speciosa (Banaba) extracts.

    PubMed

    Mahaboob Basha, P; Saumya, S M

    2013-04-01

    Chronic fluoride intoxication results in pathophysiological complications pertaining to soft tissues, called non-skeletal fluorosis. This study examined whether fluoride-induced alterations in selected parameters that are indicative of mitochondrial dysfunction accompany the toxic effects of fluoride in discrete brain regions in vivo and also explored the possibility of treatment with Ginseng (GE) and Banaba (BLE) either alone or with their co-exposure which is capable of reversing parameters indicative of fluoride-induced impairments in mitochondrial function. Swiss mice, Mus musculus, were given 270 ppm fluoride (600 ppm NaF) in their drinking water for 30 days, while continuing the fluoride exposure, toxicated animals were given differential doses (50-250 mg/kg body wt) of phytoextracts through oral gavage for 2 weeks. Discrete brain regions separated from dissected animals to perform biochemical assessments. Disturbances in mitochondrial enzyme complexes (I-IV) and decrements in TCA enzymes (ICDH, SDH, and aconitase) were noted in discrete brain regions upon F exposure, suggesting mitochondrial dysfunction. In addition, a significant reduction in oxidative stress indices with increased MDA content as well as decrease in reduced glutathione content and increases in catalase and SOD enzyme activity suggests the involvement of severe oxidative stress affecting the mitochondrial function(s). Treatment with either GE or BLE reversed F-induced alterations in augmenting the suppressed complex enzymes followed by TCA enzymes and oxidative stress indices in a dose independent manner. However, the co-exposure of GE and BLE at a dose of 150 mg/kgbw appeared to restore mitochondrial functioning. These results provide in vivo evidence supporting the hypothesis that fluoride induces impairments in mitochondrial function, which can be reversed by treatment with GE and BLE as well their co-exposure at 150 mg/kgbw.

  19. High-density natural luffa sponge as anaerobic microorganisms carrier for degrading 1,1,1-TCA in groundwater.

    PubMed

    Wang, Wenbing; Wu, Yanqing; Zhang, Chi

    2017-03-01

    Anaerobic microorganisms were applied to degrade organic contaminants in groundwater with permeable reactive barriers (PRBs). However, anaerobic microorganisms need to select optimal immobilizing material as carrier. The potential of high-density natural luffa sponge (HDLS) (a new variety of luffa) for the immobilization and protection of anaerobic microorganisms was investigated. The HDLS has a dense structure composed of a complicated interwoven fibrous network. Therefore, the abrasion rate of HDLS (0.0068 g s(-1)) was the smallest among the four carriers [HDLS, ordinary natural luffa sponge (OLS), polyurethane sponge (PS), and gel carrier AQUAPOROUSGEL (APG)]. The results suggest that it also had the greatest water retention (10.26 H2O-g dry carrier-g(-1)) and SS retention (0.21 g dry carrier-g(-1)). In comparison to well-established commercialized gel carrier APG, HDLS was of much better mechanical strength, hydrophilicity and stability. Microbial-immobilized HDLS also had the best performance for the remediation of 1,1,1-TCA simulated groundwater. Analysis of the clone libraries from microorganism-immobilized HDLS showed the HDLS could protect microorganisms from the toxicity of 1,1,1-TCA and maintain the stability of microbial community diversity. The mechanism of HDLS immobilizing and protecting microorganisms was proposed as follows. The HDLS had a micron-scale honeycomb structure (30-40 μm) and an irregular ravine structure (4-20 μm), which facilitate the immobilization of anaerobic microorganisms and protect the anaerobic microorganisms.

  20. Precipitation Indices Low Countries

    NASA Astrophysics Data System (ADS)

    van Engelen, A. F. V.; Ynsen, F.; Buisman, J.; van der Schrier, G.

    2009-09-01

    Since 1995, KNMI published a series of books(1), presenting an annual reconstruction of weather and climate in the Low Countries, covering the period AD 763-present, or roughly, the last millennium. The reconstructions are based on the interpretation of documentary sources predominantly and comparison with other proxies and instrumental observations. The series also comprises a number of classifications. Amongst them annual classifications for winter and summer temperature and for winter and summer dryness-wetness. The classification of temperature have been reworked into peer reviewed (2) series (AD 1000-present) of seasonal temperatures and temperature indices, the so called LCT (Low Countries Temperature) series, now incorporated in the Millennium databases. Recently we started a study to convert the dryness-wetness classifications into a series of precipitation; the so called LCP (Low Countries Precipitation) series. A brief outline is given here of the applied methodology and preliminary results. The WMO definition for meteorological drought has been followed being that a period is called wet respectively dry when the amount of precipitation is considerable more respectively less than usual (normal). To gain a more quantitative insight for four locations, geographically spread over the Low Countries area (De Bilt, Vlissingen, Maastricht and Uccle), we analysed the statistics of daily precipitation series, covering the period 1900-present. This brought us to the following definition, valid for the Low Countries: A period is considered as (very) dry respectively (very) wet if over a continuous period of at least 60 days (~two months) cq 90 days (~three months) on at least two out of the four locations 50% less resp. 50% more than the normal amount for the location (based on the 1961-1990 normal period) has been measured. This results into the following classification into five drought classes hat could be applied to non instrumental observations: Very wet period

  1. Effect of calcium oxide on the efficiency of ferrous ion oxidation and total iron precipitation during ferrous ion oxidation in simulated acid mine drainage treatment with inoculation of Acidithiobacillus ferrooxidans.

    PubMed

    Liu, Fenwu; Zhou, Jun; Jin, Tongjun; Zhang, Shasha; Liu, Lanlan

    2016-01-01

    Calcium oxide was added into ferrous ion oxidation system in the presence of Acidithiobacillus ferrooxidans at concentrations of 0-4.00 g/L. The pH, ferrous ion oxidation efficiency, total iron precipitation efficiency, and phase of the solid minerals harvested from different treatments were investigated during the ferrous ion oxidation process. In control check (CK) system, pH of the solution decreased from 2.81 to 2.25 when ferrous ions achieved complete oxidation after 72 h of Acidithiobacillus ferrooxidans incubation without the addition of calcium oxide, and total iron precipitation efficiency reached 20.2%. Efficiency of ferrous ion oxidation and total iron precipitation was significantly improved when the amount of calcium oxide added was ≤1.33 g/L, and the minerals harvested from systems were mainly a mixture of jarosite and schwertmannite. For example, the ferrous ion oxidation efficiency reached 100% at 60 h and total iron precipitation efficiency was increased to 32.1% at 72 h when 1.33 g/L of calcium oxide was added. However, ferrous ion oxidation and total iron precipitation for jarosite and schwertmannite formation were inhibited if the amount of calcium oxide added was above 2.67 g/L, and large amounts of calcium sulfate dihydrate were generated in systems.

  2. Teaching about citric acid cycle using plant mitochondrial preparations: Some assays for use in laboratory courses*.

    PubMed

    Vicente, Joaquim A F; Gomes-Santos, Carina S S; Sousa, Ana Paula M; Madeira, Vítor M C

    2005-03-01

    Potato tubers and turnip roots were used to prepare purified mitochondria for laboratory practical work in the teaching of the citric acid cycle (TCA cycle). Plant mitochondria are particularly advantageous over the animal fractions to demonstrate the TCA cycle enzymatic steps, by using simple techniques to measure O(2) consumption and transmembrane potential (ΔΨ). The several TCA cycle intermediates induce specific enzyme activities, which can be identified by respiratory parameters. Such a strategy is also used to evidence properties of the TCA cycle enzymes: ADP stimulation of isocitrate dehydrogenase and α-ketoglutarate dehydrogenase; activation by citrate of downstream oxidation steps, e.g. succinate dehydrogenase; and regulation of the activity of isocitrate dehydrogenase by citrate action on the citrate/isocitrate carrier. Furthermore, it has been demonstrated that, in the absence of exogenous Mg(2+) , isocitrate-dependent respiration favors the alternative oxidase pathway, as judged by changes of the ADP/O elicited by the inhibitor n-propyl galate. These are some examples of assays related with TCA cycle intermediates we can use in laboratory courses.

  3. The tricarboxylic acid cycle in Shewanella oneidensis is independent of Fur and RyhB control

    SciTech Connect

    Yang, Yunfeng; McCue, Lee Ann; Parsons, Andrea; Feng, Sheng; Zhou, Jizhong

    2010-01-01

    Background: It is well established in E. coli and Vibrio cholerae that strains harboring mutations in the ferric uptake regulator gene (fur) are unable to utilize tricarboxylic acid (TCA) compounds, due to the down-regulation of key TCA cycle enzymes, such as AcnA and SdhABCD. This down-regulation is mediated by a Fur-regulated small regulatory RNA named RyhB. It is unclear in the g-proteobacterium S. oneidensis whether TCA is also regulated by Fur and RyhB. Results: In the present study, we showed that a fur deletion mutant of S. oneidensis could utilize TCA compounds. Consistently, expression of the TCA cycle genes acnA and sdhA was not down-regulated in the mutant. To explore this observation further, we identified a ryhB gene in Shewanella species and experimentally demonstrated the gene expression. Further experiments suggested that RyhB was up-regulated in fur mutant, but that AcnA and SdhA were not controlled by RyhB. Conclusions: These cumulative results delineate an important difference of the Fur-RyhB regulatory cycle between S. oneidensis and other g-proteobacteria. This work represents a step forward for understanding the unique regulation in S. oneidensis.

  4. Acid rain

    SciTech Connect

    Sweet, W.

    1980-06-20

    Acid precipitation includes not only rain but also acidified snow, hail and frost, as well as sulfur and nitrogen dust. The principal source of acid precipitation is pollution emitted by power plants and smelters. Sulfur and nitrogen compounds contained in the emissions combine with moisture to form droplets with a high acid content - sometimes as acidic as vinegar. When sufficiently concentrated, these acids can kill fish and damage material structures. Under certain circumstances they may reduce crop and forest yields and cause or aggravate respiratory diseases in humans. During the summer, especially, pollutants tend to collect over the Great Lakes in high pressure systems. Since winds typically are westerly and rotate clockwise around high pressure systems, the pollutants gradually are dispersed throughout the eastern part of the continent.

  5. Magnetite seeded precipitation of phosphate.

    PubMed

    Karapinar, Nuray; Hoffmann, Erhard; Hahn, Hermann H

    2004-07-01

    Seeded precipitation of Ca phosphate on magnetite mineral (Fe3O4) surfaces was investigated using a Jar Test system in supersaturated solutions at 20 degrees C and ionic strength 0.01 mol l(-1) with relative super saturation, 12.0-20.0 for HAP. pH of the solution, initial phosphorus concentration and molar Ca/P ratio were investigated as the main parameters, which effect the seeded precipitation of Ca phosphate. Results showed that there is no pronounced effect of magnetite seed, neither positive nor negative on the amount of calcium phosphate precipitation. pH was found to be the main parameter that determines the phosphate precipitated onto the seed surface. Increasing of the pH of precipitation reaction was resulted in the decrease in percentage amount of phosphate precipitated onto seed surfaces to total precipitation (magnetite seeded precipitation efficiency). It was concluded that the pH dependence of magnetite-seeded precipitation should be considered in the light of its effect on the supersaturated conditions of solution. Saturation index (SI) of solution with respect to the precipitate phase was considered the driving force for the precipitation. A simulation programme PHREEQC (Version 2) was employed to calculate the Saturation-index with respect to hydroxyapatite (HAP) of the chemically defined precipitation system. It was found a good relationship between SI of solution with respect to HAP and the magnetite seeded precipitation efficiency, a second order polynomial function. Results showed that more favorable solution conditions for precipitation (higher SI values of solution) causes homogenous nucleation whereas heterogeneous nucleation led to a higher magnetite seeded precipitation efficiency.

  6. Measurement of Global Precipitation

    NASA Technical Reports Server (NTRS)

    Flaming, Gilbert Mark

    2004-01-01

    The Global Precipitation Measurement (GPM) Program is an international cooperative effort whose objectives are to (a) obtain increased understanding of rainfall processes, and (b) make frequent rainfall measurements on a global basis. The National Aeronautics and Space Administration (NASA) of the United States and the Japanese Aviation and Exploration Agency (JAXA) have entered into a cooperative agreement for the formulation and development of GPM. This agreement is a continuation of the partnership that developed the highly successful Tropical Rainfall Measuring Mission (TRMM) that was launched in November 1997; this mission continues to provide valuable scientific and meteorological information on rainfall and the associated processes. International collaboration on GPM from other space agencies has been solicited, and discussions regarding their participation are currently in progress. NASA has taken lead responsibility for the planning and formulation of GPM, Key elements of the Program to be provided by NASA include a Core satellite bus instrumented with a multi-channel microwave radiometer, a Ground Validation System and a ground-based Precipitation Processing System (PPS). JAXA will provide a Dual-frequency Precipitation Radar for installation on the Core satellite and launch services. Other United States agencies and international partners may participate in a number of ways, such as providing rainfall measurements obtained from their own national space-borne platforms, providing local rainfall measurements to support the ground validation activities, or providing hardware or launch services for GPM constellation spacecraft. This paper will present an overview of the current planning for the GPM Program, and discuss in more detail the status of the lead author's primary responsibility, development and acquisition of the GPM Microwave Imager.

  7. Cross-talk between branched-chain amino acids and hepatic mitochondria is compromised in nonalcoholic fatty liver disease

    PubMed Central

    Kalavalapalli, Srilaxmi; Bril, Fernando; Garrett, Timothy J.; Nautiyal, Manisha; Mathew, Justin T.; Williams, Caroline M.; Cusi, Kenneth

    2015-01-01

    Elevated plasma branched-chain amino acids (BCAA) in the setting of insulin resistance have been relevant in predicting type 2 diabetes mellitus (T2DM) onset, but their role in the etiology of hepatic insulin resistance remains uncertain. We determined the link between BCAA and dysfunctional hepatic tricarboxylic acid (TCA) cycle, which is a central feature of hepatic insulin resistance and nonalcoholic fatty liver disease (NAFLD). Plasma metabolites under basal fasting and euglycemic hyperinsulinemic clamps (insulin stimulation) were measured in 94 human subjects with varying degrees of insulin sensitivity to identify their relationships with insulin resistance. Furthermore, the impact of elevated BCAA on hepatic TCA cycle was determined in a diet-induced mouse model of NAFLD, utilizing targeted metabolomics and nuclear magnetic resonance (NMR)-based metabolic flux analysis. Insulin stimulation revealed robust relationships between human plasma BCAA and indices of insulin resistance, indicating chronic metabolic overload from BCAA. Human plasma BCAA and long-chain acylcarnitines also showed a positive correlation, suggesting modulation of mitochondrial metabolism by BCAA. Concurrently, mice with NAFLD failed to optimally induce hepatic mTORC1, plasma ketones, and hepatic long-chain acylcarnitines, following acute elevation of plasma BCAA. Furthermore, elevated BCAA failed to induce multiple fluxes through hepatic TCA cycle in mice with NAFLD. Our data suggest that BCAA are essential to mediate efficient channeling of carbon substrates for oxidation through mitochondrial TCA cycle. Impairment of BCAA-mediated upregulation of the TCA cycle could be a significant contributor to mitochondrial dysfunction in NAFLD. PMID:26058864

  8. Cross-talk between branched-chain amino acids and hepatic mitochondria is compromised in nonalcoholic fatty liver disease.

    PubMed

    Sunny, Nishanth E; Kalavalapalli, Srilaxmi; Bril, Fernando; Garrett, Timothy J; Nautiyal, Manisha; Mathew, Justin T; Williams, Caroline M; Cusi, Kenneth

    2015-08-15

    Elevated plasma branched-chain amino acids (BCAA) in the setting of insulin resistance have been relevant in predicting type 2 diabetes mellitus (T2DM) onset, but their role in the etiology of hepatic insulin resistance remains uncertain. We determined the link between BCAA and dysfunctional hepatic tricarboxylic acid (TCA) cycle, which is a central feature of hepatic insulin resistance and nonalcoholic fatty liver disease (NAFLD). Plasma metabolites under basal fasting and euglycemic hyperinsulinemic clamps (insulin stimulation) were measured in 94 human subjects with varying degrees of insulin sensitivity to identify their relationships with insulin resistance. Furthermore, the impact of elevated BCAA on hepatic TCA cycle was determined in a diet-induced mouse model of NAFLD, utilizing targeted metabolomics and nuclear magnetic resonance (NMR)-based metabolic flux analysis. Insulin stimulation revealed robust relationships between human plasma BCAA and indices of insulin resistance, indicating chronic metabolic overload from BCAA. Human plasma BCAA and long-chain acylcarnitines also showed a positive correlation, suggesting modulation of mitochondrial metabolism by BCAA. Concurrently, mice with NAFLD failed to optimally induce hepatic mTORC1, plasma ketones, and hepatic long-chain acylcarnitines, following acute elevation of plasma BCAA. Furthermore, elevated BCAA failed to induce multiple fluxes through hepatic TCA cycle in mice with NAFLD. Our data suggest that BCAA are essential to mediate efficient channeling of carbon substrates for oxidation through mitochondrial TCA cycle. Impairment of BCAA-mediated upregulation of the TCA cycle could be a significant contributor to mitochondrial dysfunction in NAFLD.

  9. METHOD OF IMPROVING THE CARRIER PRECIPITATION OF PLUTONIUM

    DOEpatents

    Kamack, H.J.; Balthis, J.H.

    1958-12-01

    Plutonium values can be recovered from acidic solutlons by adding lead nitrate, hydrogen fluoride, lantha num nitrate, and sulfurlc acid to the solution to form a carrler preclpitate. The lead sulfate formed improves the separatlon characteristics of the lanthanum fluoride carrier precipitate,

  10. Urease activity in microbiologically-induced calcite precipitation.

    PubMed

    Bachmeier, Keri L; Williams, Amy E; Warmington, John R; Bang, Sookie S

    2002-02-14

    The role of microbial urease in calcite precipitation was studied utilizing a recombinant Escherichia coli HB101 containing a plasmid, pBU11, that encodes Bacillus pasteurii urease. The calcite precipitation by E. coli HB101 (pBU11) was significant although its precipitation level was not as high as that by B. pasteurii. Addition of low concentrations (5-100 microM) of nickel, the cofactor of urease, to the medium further enhanced calcite precipitation by E. coli (pBU11). Calcite precipitation induced by both B. pasteurii and E. coli (pBU11) was inhibited in the presence of a urease inhibitor, acetohydroxamic acid (AHA). These observations on the recombinant urease have confirmed that urease activity is essential for microbiologically-induced calcite precipitation. Partially purified B. pasteurii urease was immobilized in polyurethane (PU) foam to compare the efficacy of calcite precipitation between the free and immobilized enzymes. The immobilized urease showed higher K(m) and lower V(max) values, which were reflected by a slower overall calcite precipitation. However, scanning electron micrographs (SEM) identified that the calcite precipitation occurred throughout the matrices of polyurethane. Furthermore, PU-immobilized urease retained higher enzymatic activities at high temperatures and in the presence of a high concentration of pronase, indicating that immobilization protects the enzyme activity from environmental changes.

  11. The effectiveness of matrix cauterization with trichloroacetic acid in the treatment of ingrown toenails

    PubMed Central

    Terzi, Erdinc; Guvenc, Ulas; Türsen, Belma; Kaya, Tamer İrfan; Erdem, Teoman; Türsen, Ümit

    2015-01-01

    Ingrown toenail is an often painful clinical condition that usually affects the big toe. Chemical matricectomy with phenol has a low recurrence rate and good cosmetic results. However, it produces extensive tissue destruction that can result in drainage and delayed healing. Alternatives such as sodium hydroxide and trichloroacetic acid (TCA) have therefore come into vogue. A total of 39 patients with 56 ingrown toenail edges underwent chemical matricectomy with 90% TCA after partial nail avulsion. In most of the patients, adverse effects such as postoperative pain and drainage were minimal. One patient who underwent matricectomy had recurrence in a single nail edge (1.8%) at 12 months follow-up. No recurrence was observed among 38 patients during the mean follow-up period. This was considered to be statistically significant (P < 0.001). Partial nail avulsion followed by TCA matricectomy is a safe, simple, and effective method with low rates of postoperative morbidity and high rates of success. PMID:25657908

  12. Superficial basal cell carcinoma treated with 70% trichloroacetic acid applied topically: a case study

    PubMed Central

    Chiriac, Anca; Brzezinski, Piotr; Moldovan, Cosmin; Podoleanu, Cristian; Coros, Marius Florin; Stolnicu, Simona

    2017-01-01

    Background Basal cell carcinoma (BCC) is the most common form of skin cancer, affecting millions of people worldwide. The treatment concept for BCCs is the surgical one, but it is costly, as such, searching for alternative medical therapeutics is justified. Aim To highlight the efficacy of high concentration (70%) trichloroacetic acid (TCA) as a choice therapy for low-risk BCC. Method and patient Authors present, for the first time, the use of a high concentration TCA applied once a week for 2 consecutive weeks with a toothpick, on a patient with BCC on the right preauricular area. Results On examination 4 weeks later, the lesion was not clinically and dermatoscopically evidenced. Conclusion High concentration TCA could be an effective and safe, non-invasive choice of therapy for low-risk BCC, easy to perform, not expensive, with good cosmetic results, especially for patients who are not likely to undergo invasive or expensive treatments. PMID:28260938

  13. Precipitation Extremes Under Climate Change.

    PubMed

    O'Gorman, Paul A

    The response of precipitation extremes to climate change is considered using results from theory, modeling, and observations, with a focus on the physical factors that control the response. Observations and simulations with climate models show that precipitation extremes intensify in response to a warming climate. However, the sensitivity of precipitation extremes to warming remains uncertain when convection is important, and it may be higher in the tropics than the extratropics. Several physical contributions govern the response of precipitation extremes. The thermodynamic contribution is robust and well understood, but theoretical understanding of the microphysical and dynamical contributions is still being developed. Orographic precipitation extremes and snowfall extremes respond differently from other precipitation extremes and require particular attention. Outstanding research challenges include the influence of mesoscale convective organization, the dependence on the duration considered, and the need to better constrain the sensitivity of tropical precipitation extremes to warming.

  14. Lack of formic acid production in rat hepatocytes and human renal proximal tubule cells exposed to chloral hydrate or trichloroacetic acid.

    PubMed

    Lock, Edward A; Reed, Celia J; McMillan, Joellyn M; Oatis, John E; Schnellmann, Rick G

    2007-02-12

    The industrial solvent trichloroethylene (TCE) and its major metabolites have been shown to cause formic aciduria in male rats. We have examined whether chloral hydrate (CH) and trichloroacetic acid (TCA), known metabolites of TCE, produce an increase in formic acid in vitro in cultures of rat hepatocytes or human renal proximal tubule cells (HRPTC). The metabolism and cytotoxicity of CH was also examined to establish that the cells were metabolically active and not compromised by toxicity. Rat hepatocytes and HRPTC were cultured in serum-free medium and then treated with 0.3-3mM CH for 3 days or 0.03-3mM CH for 10 days, respectively and formic acid production, metabolism to trichloroethanol (TCE-OH) and TCA and cytotoxicity determined. No increase in formic acid production in rat hepatocytes or HRPTC exposed to CH was observed over and above that due to chemical degradation, neither was formic acid production observed in rat hepatocytes exposed to TCA. HRPTC metabolized CH to TCE-OH and TCA with a 12-fold greater capacity to form TCE-OH versus TCA. Rat hepatocytes exhibited a 1.6-fold and three-fold greater capacity than HRPTC to form TCE-OH and TCA, respectively. CH and TCA were not cytotoxic to rat hepatocytes at concentrations up to 3mM/day for 3 days. With HRPTC, one sample showed no cytotoxicity to CH at concentrations up to 3mM/day for 10 days, while in another cytotoxicity was seen at 1mM/day for 3 days. In summary, increased formic acid production was not observed in rat hepatocytes or HRPTC exposed to TCE metabolites, suggesting that the in vivo response cannot be modelled in vitro. CH was toxic to HRPTC at millimolar concentrations/day over 10 days, while glutathione derived metabolites of TCE were toxic at micromolar concentrations/day over 10 days [Lock, E.A., Reed, C.J., 2006. Trichloroethylene: mechanisms of renal toxicity and renal cancer and relevance to risk assessment. Toxicol. Sci. 19, 313-331] supporting the view that glutathione derived

  15. Acidic bile salts modulate the squamous epithelial barrier function by modulating tight junction proteins.

    PubMed

    Chen, Xin; Oshima, Tadayuki; Tomita, Toshihiko; Fukui, Hirokazu; Watari, Jiro; Matsumoto, Takayuki; Miwa, Hiroto

    2011-08-01

    Experimental models for esophageal epithelium in vitro either suffer from poor differentiation or complicated culture systems. An air-liquid interface system with normal human bronchial epithelial cells can serve as a model of esophageal-like squamous epithelial cell layers. Here, we explore the influence of bile acids on barrier function and tight junction (TJ) proteins. The cells were treated with taurocholic acid (TCA), glycocholic acid (GCA), or deoxycholic acid (DCA) at different pH values, or with pepsin. Barrier function was measured by transepithelial electrical resistance (TEER) and the diffusion of paracellular tracers (permeability). The expression of TJ proteins, including claudin-1 and claudin-4, was examined by Western blotting of 1% Nonidet P-40-soluble and -insoluble fractions. TCA and GCA dose-dependently decreased TEER and increased paracellular permeability at pH 3 after 1 h. TCA (4 mM) or GCA (4 mM) did not change TEER and permeability at pH 7.4 or pH 4. The combination of TCA and GCA at pH 3 significantly decreased TEER and increased permeability at lower concentrations (2 mM). Pepsin (4 mg/ml, pH 3) did not have any effect on barrier function. DCA significantly decreased the TEER and increased permeability at pH 6, a weakly acidic condition. TCA (4 mM) and GCA (4 mM) significantly decreased the insoluble fractions of claudin-1 and claudin-4 at pH 3. In conclusion, acidic bile salts disrupted the squamous epithelial barrier function partly by modulating the amounts of claudin-1 and claudin-4. These results provide new insights for understanding the role of TJ proteins in esophagitis.

  16. Characterisation of Suspension Precipitated Nanocrystalline Hydroxyapatite Powders

    NASA Astrophysics Data System (ADS)

    Mallik, P. K.; Swain, P. K.; Patnaik, S. C.

    2016-02-01

    Hydroxyapatite (HA) is a well-known biomaterial for coating on femoral implants, filling of dental cavity and scaffold for tissue replacement. Hydroxyapatite possess limited load bearing capacity due to their brittleness. In this paper, the synthesis of nanocrystalline hydroxyapatite powders was prepared by dissolving calcium oxide in phosphoric acid, followed by addition of ammonia liquor in a beaker. The prepared solution was stirred by using magnetic stirrer operated at temperature of 80°C for an hour. This leads to the formation of hydroxyapatite precipitate. The precipitate was dried in oven for overnight at 100°C. The dried agglomerated precipitate was calcined at 800°C in conventional furnace for an hour. The influence of calcium oxide concentration and pH on the resulting precipitates was studied using BET, XRD and SEM. As result, a well-defined sub-rounded morphology of powders size of ∼41 nm was obtained with a salt concentration of 0.02 M. Finally, it can be concluded that small changes in the reaction conditions led to large changes in final size, shape and degree of aggregation of the hydroxyapatite particles.

  17. The CC chemokine thymus-derived chemotactic agent 4 (TCA-4, secondary lymphoid tissue chemokine, 6Ckine, exodus-2) triggers lymphocyte function-associated antigen 1-mediated arrest of rolling T lymphocytes in peripheral lymph node high endothelial venules.

    PubMed

    Stein, J V; Rot, A; Luo, Y; Narasimhaswamy, M; Nakano, H; Gunn, M D; Matsuzawa, A; Quackenbush, E J; Dorf, M E; von Andrian, U H

    2000-01-03

    T cell homing to peripheral lymph nodes (PLNs) is defined by a multistep sequence of interactions between lymphocytes and endothelial cells in high endothelial venules (HEVs). After initial tethering and rolling via L-selectin, firm adhesion of T cells requires rapid upregulation of lymphocyte function-associated antigen 1 (LFA-1) adhesiveness by a previously unknown pathway that activates a Galpha(i)-linked receptor. Here, we used intravital microscopy of murine PLNs to study the role of thymus-derived chemotactic agent (TCA)-4 (secondary lymphoid tissue chemokine, 6Ckine, Exodus-2) in homing of adoptively transferred T cells from T-GFP mice, a transgenic strain that expresses green fluorescent protein (GFP) selectively in naive T lymphocytes (T(GFP) cells). TCA-4 was constitutively presented on the luminal surface of HEVs, where it was required for LFA-1 activation on rolling T(GFP) cells. Desensitization of the TCA-4 receptor, CC chemokine receptor 7 (CCR7), blocked T(GFP) cell adherence in wild-type HEVs, whereas desensitization to stromal cell-derived factor (SDF)-1alpha (the ligand for CXC chemokine receptor 4 [CXCR4]) did not affect T(GFP) cell behavior. TCA-4 protein was not detected on the luminal surface of PLN HEVs in plt/plt mice, which have a congenital defect in T cell homing to PLNs. Accordingly, T(GFP) cells rolled but did not arrest in plt/plt HEVs. When TCA-4 was injected intracutaneously into plt/plt mice, the chemokine entered afferent lymph vessels and accumulated in draining PLNs. 2 h after intracutaneous injection, luminal presentation of TCA-4 was detectable in a subset of HEVs, and LFA-1-mediated T(GFP) cell adhesion was restored in these vessels. We conclude that TCA-4 is both required and sufficient for LFA-1 activation on rolling T cells in PLN HEVs. This study also highlights a hitherto undocumented role for chemokines contained in afferent lymph, which may modulate leukocyte recruitment in draining PLNs.

  18. BASIC PEROXIDE PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINANTS

    DOEpatents

    Seaborg, G.T.; Perlman, I.

    1959-02-10

    A process is described for the separation from each other of uranyl values, tetravalent plutonium values and fission products contained in an aqueous acidic solution. First the pH of the solution is adjusted to between 2.5 and 8 and hydrogen peroxide is then added to the solution causing precipitation of uranium peroxide which carries any plutonium values present, while the fission products remain in solution. Separation of the uranium and plutonium values is then effected by dissolving the peroxide precipitate in an acidic solution and incorporating a second carrier precipitate, selective for plutonium. The plutonium values are thus carried from the solution while the uranium remains flissolved. The second carrier precipitate may be selected from among the group consisting of rare earth fluorides, and oxalates, zirconium phosphate, and bismuth lihosphate.

  19. The different phases in the precipitation of dicalcium phosphate dihydrate

    NASA Astrophysics Data System (ADS)

    Ferreira, A.; Oliveira, C.; Rocha, F.

    2003-05-01

    The precipitation of dicalcium phosphate dihydrate, brushite, by mixing a calcium hydroxide suspension and an orthophosphoric acid solution in equimolar quantities, has been investigated in a batch system at 25°C. The concentration of calcium hydroxide and orthophosphoric acid, before mixing, ranged from 50 to 300 mmol dm -3. The phase first precipitated is Ca 5OH(PO 4) 3, hydroxyapatite. The precipitation process of brushite is divided into five stages and is similar for all initial experimental conditions. The extension of each stage varies with the initial reagents' concentrations. These stages are discussed individually as a function of pH and reagents' concentrations. The precipitate was analysed by scanning electron microscopy and X-ray diffraction. The solubility of brushite was determined at 25°C, 30°C and 35°C, and in the pH range 4.5-8.

  20. The Global Precipitation Climatology Project (GPCP) Combined Precipitation Dataset

    NASA Technical Reports Server (NTRS)

    Huffman, George J.; Adler, Robert F.; Arkin, Philip; Chang, Alfred; Ferraro, Ralph; Gruber, Arnold; Janowiak, John; McNab, Alan; Rudolf, Bruno; Schneider, Udo

    1997-01-01

    The Global Precipitation Climatology Project (GPCP) has released the GPCP Version 1 Combined Precipitation Data Set, a global, monthly precipitation dataset covering the period July 1987 through December 1995. The primary product in the dataset is a merged analysis incorporating precipitation estimates from low-orbit-satellite microwave data, geosynchronous-orbit -satellite infrared data, and rain gauge observations. The dataset also contains the individual input fields, a combination of the microwave and infrared satellite estimates, and error estimates for each field. The data are provided on 2.5 deg x 2.5 deg latitude-longitude global grids. Preliminary analyses show general agreement with prior studies of global precipitation and extends prior studies of El Nino-Southern Oscillation precipitation patterns. At the regional scale there are systematic differences with standard climatologies.

  1. The use of glycolic acid as a peeling agent.

    PubMed

    Murad, H; Shamban, A T; Premo, P S

    1995-04-01

    Glycolic acid is a member of the AHA family, which occurs naturally in foods and has been used for centuries as a cutaneous rejuvenation treatment. Recently it has proved to be a versatile peeling agent and it is now widely used to treat many defects of the epidermis and papillary dermis in a variety of strengths, ranging from 20% to 70%, depending on the condition being treated. People of almost any skin type and color are candidates, and almost any area of the body can be peeled. Several weeks prior to a peel the skin may be prepared with topical tretinoin or glycolic acid, and immediately prior to the peel the skin may be degreased with a variety of agents. Following the peel the skin is carefully observed for any complications such as hyperpigmentation and infection. Results are maintained with serial peels and at-home use of tretinoin or glycolic acid, as well as sun avoidance. The glycolic acid can be applied simultaneously with TCA and is another technique for a medium-depth peel. Comparison of 35% TCA-treated skin with 70% glycolic acid-treated skin examined histologically at different times reveals similar changes in papillary dermis connective tissue proteins, epidermal necrosis seen only with TCA, and reversion at 2 years postpeel to pretreatment appearance.

  2. Biosynthesis of pyruvic acid from glucose by Blastobotrys adeninivorans.

    PubMed

    Kamzolova, Svetlana V; Morgunov, Igor G

    2016-09-01

    The ability of taxonomically different yeasts to synthesize pyruvic acid (PA) from glucose was studied. The study showed that many yeasts are able to produce PA from glucose under the condition of growth limitation by thiamine. This ability was found in the yeast Blastobotrys adeninivorans for the first time. The production (oversynthesis) of PA in this yeast can be explained by disturbance in the function of thiamine-dependent pyruvate dehydrogenase. Namely, the partial inhibition of this enzyme brings about the excretion of PA from the yeast cells. Due to incomplete inhibition of pyruvate dehydrogenase, the formation of acetyl-CoA continues, although at a lower level, maintaining the synthesis of α-ketoglutaric acid (KGA) in the tricarboxylic acid (TCA) cycle. KGA is no longer oxidized in the TCA cycle, because thiamine limitation inhibits α-ketoglutarate dehydrogenase. As a result, KGA is excreted from the yeast cells as a byproduct of PA oversynthesis. Furthermore, the increased level of KGA in the yeast cells inhibits NAD-dependent isocitrate dehydrogenase in the TCA cycle and enhances the production and excretion of citric acid, another byproduct of PA oversynthesis. During cultivation in a fermentor, the strain Blastobotrys adeninivorans VKM Y-2677 produced 43.2 g l(-1) PA from glucose with a product yield (YPA) of 0.77 g PA/g glucose. The proportion of PA to byproducts was 18:1 for KGA and 8:1 for citric acid.

  3. Auroral helium precipitation.

    NASA Technical Reports Server (NTRS)

    Axford, W. I.; Chivers, H. J. A.; Eberhardt, P.; Geiss, J.; Buehler, F.

    1972-01-01

    Application of the metal foil sampling technique, which has been used to measure helium, neon, and argon fluxes in the solar wind, to the problem of measuring the fluxes of these gases in the auroral primary radiation. Aluminum and platinum foils have been flown into two bright auroras and have been recovered. The foils have been analyzed for helium and neon isotopes with a mass spectrometer; so far only He4 has been detected. In the first flight the precipitating flux of He4 with particle energies above about 1 keV was approximately 1,000,000 per sq cm per sec, and the backscattered flux was smaller by about a factor of 10. In the second flight the aurora was less bright, and the He4 fluxes were lower by a factor of about 2. A rough analysis suggests that the mean energy of the incident particles was greater than 3 keV.

  4. Immunoaffinity centrifugal precipitation chromatography.

    PubMed

    Qi, Lin; Ito, Yoichiro

    2007-06-01

    Purification of proteins based on immunoaffinity has been performed using a solid support coated with antibody against the target proteins. The method requires immobilizing the antibody onto the solid support using protein A or G, and has a risk of adsorptive loss of target proteins onto the solid support. Centrifugal precipitation chromatography has been successfully used to purify enzymes, such as ketosteroid isomerase and hyaluronidase without the use of solid support. The purpose of this study is to demonstrate that immunoaffinity centrifugal precipitation chromatography is capable of isolating an antigen by exploiting antigen-antibody binding. The separation was initiated by filling both channels with 40% saturated ammonium sulfate (AS) of pH 4-4.5 followed by loading 20 microl of human plasma (National Institutes of Health blood bank) mixed with 2 mg of rabbit anti-HSA (human serum protein) antibody (Sigma). Then, the sample channel was eluted with water at 0.03 ml/min and AS channel with 40% AS solution of pH 4-4.5 at 1 ml/min until all non-binding components were eluted. Then, the releasing reagent (50% AS solution containing 0.5 M glycine and 10% ammonium hydroxide at pH 10) was introduced through the AS channel to release the target protein (HSA). The retained antibody was recovered by eluting the sample channel with water at 1 ml/min. A hollow fiber membrane device at the outlet (MicroKros, Spectrum, New Brunswick, NJ, USA) was provided on-line dialysis of the eluent before fractions were collected, so that the fractions could be analyzed by SDS-PAGE (sodium dodecyl sulfate - polyacrylamide gel electrophoresis) without further dialysis. The current method does not require immobilizing the antibody onto a matrix, which is used by the conventional immunoaffinity chromatography. This method ensures full recovery of the antigen and antibody, and it may be applied to purification of other proteins.

  5. Precipitation-Based ENSO Indices

    NASA Technical Reports Server (NTRS)

    Adler, Robert; Curtis, Scott

    1998-01-01

    In this study gridded observed precipitation data sets are used to construct rainfall-based ENSO indices. The monthly El Nino and La Nina Indices (EI and LI) measure the steepest zonal gradient of precipitation anomalies between the equatorial Pacific and the Maritime Continent. This is accomplished by spatially averaging precipitation anomalies using a spatial boxcar filter, finding the maximum and minimum averages within a Pacific and Maritime Continent domain for each month, and taking differences. EI and LI can be examined separately or combined to produce one ENSO Precipitation Index (ESPI). ESPI is well correlated with traditional sea surface temperature and pressure indices, leading Nino 3.4. One advantage precipitation indices have over more conventional indices, is describing the strength and position of the Walker circulation. Examples are given of tracking the impact of ENSO events on the tropical precipitation fields.

  6. Acid Rain

    USGS Publications Warehouse

    Bricker, Owen P.; Rice, Karen C.

    1995-01-01

    Although acid rain is fading as a political issue in the United States and funds for research in this area have largely disappeared, the acidity of rain in the Eastern United States has not changed significantly over the last decade, and it continues to be a serious environmental problem. Acid deposition (commonly called acid rain) is a term applied to all forms of atmospheric deposition of acidic substances - rain, snow, fog, acidic dry particulates, aerosols, and acid-forming gases. Water in the atmosphere reacts with certain atmospheric gases to become acidic. For example, water reacts with carbon dioxide in the atmosphere to produce a solution with a pH of about 5.6. Gases that produce acids in the presence of water in the atmosphere include carbon dioxide (which converts to carbonic acid), oxides of sulfur and nitrogen (which convert to sulfuric and nitric acids}, and hydrogen chloride (which converts to hydrochloric acid). These acid-producing gases are released to the atmosphere through natural processes, such as volcanic emissions, lightning, forest fires, and decay of organic matter. Accordingly, precipitation is slightly acidic, with a pH of 5.0 to 5.7 even in undeveloped areas. In industrialized areas, most of the acid-producing gases are released to the atmosphere from burning fossil fuels. Major emitters of acid-producing gases include power plants, industrial operations, and motor vehicles. Acid-producing gases can be transported through the atmosphere for hundreds of miles before being converted to acids and deposited as acid rain. Because acids tend to build up in the atmosphere between storms, the most acidic rain falls at the beginning of a storm, and as the rain continues, the acids "wash out" of the atmosphere.

  7. Assessment of the cytotoxicity and genotoxicity of haloacetic acids using microplate-based cytotoxicity test and CHO/HGPRT gene mutation assay.

    PubMed

    Zhang, Shao-Hui; Miao, Dong-Yue; Liu, Ai-Lin; Zhang, Li; Wei, Wei; Xie, Hong; Lu, Wen-Qing

    2010-12-21

    Haloacetic acids (HAAs) are the second most prevalent class of disinfection byproducts found in drinking water. The implications of HAAs presence in drinking water are a public health concern due to their potential mutagenic and carcinogenic effects. In the present study, we examined the cytotoxic and genotoxic effects of six common HAAs using a microplate-based cytotoxicity test and a hypoxanthine-guanine phosphoribosyltransferase (HGPRT) gene mutation assay in Chinese hamster ovary K1 (CHO-K1) cells. We found that their chronic cytotoxicities (72h exposure) to CHO-K1 cells varied, and we ranked their levels of toxicity in the following descending order: iodoacetic acid (IA)>bromoacetic acid (BA)>dibromoacetic acid (DBA)>chloroacetic acid (CA)>dichloroacetic acid (DCA)>trichloroacetic acid (TCA). The toxicity of IA is 1040-fold of that of TCA. All HAAs except TCA were shown to be mutagenic to CHO-K1 cells in the HGPRT gene mutation assay. The mutagenic potency was compared and ranked as follows: IA>DBA>BA>CA>DCA>TCA. There was a statistically significant correlation between cytotoxicity and mutagenicity of the HAAs in CHO-K1 cells. The microplate-based cytotoxicity assay and HGPRT gene mutation assay were suitable methods to monitor the cytotoxicity and genotoxicity of HAAs, particularly for comparing the toxic intensities quantitatively.

  8. A systematic analysis of TCA Escherichia coli mutants reveals suitable genetic backgrounds for enhanced hydrogen and ethanol production using glycerol as main carbon source.

    PubMed

    Valle, Antonio; Cabrera, Gema; Muhamadali, Howbeer; Trivedi, Drupad K; Ratray, Nicholas J W; Goodacre, Royston; Cantero, Domingo; Bolivar, Jorge

    2015-09-01

    Biodiesel has emerged as an environmentally friendly alternative to fossil fuels; however, the low price of glycerol feed-stocks generated from the biodiesel industry has become a burden to this industry. A feasible alternative is the microbial biotransformation of waste glycerol to hydrogen and ethanol. Escherichia coli, a microorganism commonly used for metabolic engineering, is able to biotransform glycerol into these products. Nevertheless, the wild type strain yields can be improved by rewiring the carbon flux to the desired products by genetic engineering. Due to the importance of the central carbon metabolism in hydrogen and ethanol synthesis, E. coli single null mutant strains for enzymes of the TCA cycle and other related reactions were studied in this work. These strains were grown anaerobically in a glycerol-based medium and the concentrations of ethanol, glycerol, succinate and hydrogen were analysed by HPLC and GC. It was found that the reductive branch is the more relevant pathway for the aim of this work, with malate playing a central role. It was also found that the putative C4-transporter dcuD mutant improved the target product yields. These results will contribute to reveal novel metabolic engineering strategies for improving hydrogen and ethanol production by E. coli.

  9. Code Calibration Applied to the TCA High-Lift Model in the 14 x 22 Wind Tunnel (Simulation With and Without Model Post-Mount)

    NASA Technical Reports Server (NTRS)

    Lessard, Wendy B.

    1999-01-01

    The objective of this study is to calibrate a Navier-Stokes code for the TCA (30/10) baseline configuration (partial span leading edge flaps were deflected at 30 degs. and all the trailing edge flaps were deflected at 10 degs). The computational results for several angles of attack are compared with experimental force, moments, and surface pressures. The code used in this study is CFL3D; mesh sequencing and multi-grid were used to full advantage to accelerate convergence. A multi-grid approach was used similar to that used for the Reference H configuration allowing point-to-point matching across all the trailingedge block interfaces. From past experiences with the Reference H (ie, good force, moment, and pressure comparisons were obtained), it was assumed that the mounting system would produce small effects; hence, it was not initially modeled. However, comparisons of lower surface pressures indicated the post mount significantly influenced the lower surface pressures, so the post geometry was inserted into the existing grid using Chimera (overset grids).

  10. Dynamics and regulation of glycolysis-tricarboxylic acid metabolism in the midgut of Spodoptera litura during metamorphosis.

    PubMed

    Hu, D; Luo, W; Fan, L F; Liu, F L; Gu, J; Deng, H M; Zhang, C; Huang, L H; Feng, Q L

    2016-04-01

    Significant changes usually take place in the internal metabolism of insects during metamorphosis. The glycolysis-tricarboxylic acid (glycolysis-TCA) pathway is important for energy metabolism. To elucidate its dynamics, the mRNA levels of genes involved in this pathway were examined in the midgut of Spodoptera litura during metamorphosis, and the pyruvate content was quantified. The expression patterns of these genes in response to starvation were examined, and the interaction between protein phosphatase 1 (PP1) and phosphofructokinase (PFK) was studied. The results revealed that the expression or activities of most glycolytic enzymes was down-regulated in prepupae and then recovered in some degree in pupae, and all TCA-related genes were remarkably suppressed in both the prepupae and pupae. Pyruvate was enriched in the pupal midgut. Taken together, these results suggest that insects decrease both glycolysis and TCA in prepupae to save energy and then up-regulate glycolysis but down-regulate TCA in pupae to increase the supply of intermediates for construction of new organs. The expression of all these genes were down-regulated by starvation, indicating that non-feeding during metamorphosis may be a regulator of glycolysis-TCA pathway in the midgut. Importantly, interaction between PP1 and PFK was identified and is suggested to be involved in the regulation of glycolysis.

  11. Inducing mineral precipitation in groundwater by addition of phosphate

    PubMed Central

    2011-01-01

    Background Induced precipitation of phosphate minerals to scavenge trace elements from groundwater is a potential remediation approach for contaminated aquifers. The success of engineered precipitation schemes depends on the particular phases generated, their rates of formation, and their long term stability. The purpose of this study was to examine the precipitation of calcium phosphate minerals under conditions representative of a natural groundwater. Because microorganisms are present in groundwater, and because some proposed schemes for phosphate mineral precipitation rely on stimulation of native microbial populations, we also tested the effect of bacterial cells (initial densities of 105 and 107 mL-1) added to the precipitation medium. In addition, we tested the effect of a trace mixture of propionic, isovaleric, formic and butyric acids (total concentration 0.035 mM). Results The general progression of mineral precipitation was similar under all of the study conditions, with initial formation of amorphous calcium phosphate, and transformation to poorly crystalline hydroxylapatite (HAP) within one week. The presence of the bacterial cells appeared to delay precipitation, although by the end of the experiments the overall extent of precipitation was similar for all treatments. The stoichiometry of the final precipitates as well as Rietveld structure refinement using x-ray diffraction data indicated that the presence of organic acids and bacterial cells resulted in an increasing a and decreasing c lattice parameter, with the higher concentration of cells resulting in the greatest distortion. Uptake of Sr into the solids was decreased in the treatments with cells and organic acids, compared to the control. Conclusions Our results suggest that the minerals formed initially during an engineered precipitation application for trace element sequestration may not be the ones that control long-term immobilization of the contaminants. In addition, the presence of

  12. Inducing Mineral Precipitation in Groundwater by Addition of Phosphate

    SciTech Connect

    Karen E. Wright; Yoshiko Fujita; Thomas Hartmann; Mark Conrad

    2011-10-01

    Induced precipitation of phosphate minerals to scavenge trace metals and radionuclides from groundwater is a potential remediation approach for contaminated aquifers. Phosphate minerals can sequester trace elements by primary mineral formation, solid solution formation and/or adsorption, and they are poorly soluble under many environmental conditions, making them attractive for long-term sustainable remediation. The success of such engineered schemes will depend on the particular mineral phases generated, their rates of formation, and their long term stability. The purpose of this study was to examine the precipitation of calcium phosphate minerals under conditions representative of a natural groundwater. Because microorganisms are present in groundwater, and because some proposed schemes for induced phosphate mineral precipitation rely on the stimulation of native groundwater populations, we also tested the effect of bacterial cells (initial densities of 105 and 107 ml-1) within the precipitation medium. We also tested the effect of a trace mixture of propionic, isovaleric, formic and butyric acids (total concentration 0.035 mM). The experiments showed that the general progression of mineral precipitation was similar under all of the conditions, with initial formation of amorphous calcium carbonate, and transformation to poorly crystalline hydroxyapatite (HAP) by the end of the week-long experiments. The presence of the bacterial cells appeared to delay precipitation, although by the end of 7 days the overall extent of precipitation was similar for all of the treatments. The stoichiometry of the final precipitates as well as results of Rietveld refinement of x-ray diffraction data indicated that the treatments including organic acids and bacterial cells resulted in increased distortion of the HAP crystal lattice, with the higher concentration of cells resulting in the greatest distortion. Uptake of Sr into the phosphate minerals was decreased in the treatments

  13. Precipitation in the Solar System

    ERIC Educational Resources Information Center

    McIntosh, Gordon

    2007-01-01

    As an astronomy instructor, I am always looking for commonly observed Earthly experiences to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote a short TPT article on frost. This paper is on the related phenomena of precipitation. Precipitation, so common on most of the Earth's…

  14. Resistivity Problems in Electrostatic Precipitation

    ERIC Educational Resources Information Center

    White, Harry J.

    1974-01-01

    The process of electrostatic precipitation has ever-increasing application in more efficient collection of fine particles from industrial air emissions. This article details a large number of new developments in the field. The emphasis is on high resistivity particles which are a common cause of poor precipitator performance. (LS)

  15. Precipitation Process and Apparatus Therefor

    DOEpatents

    Stang, Jr, L C

    1950-12-05

    This invention concerns an apparatus for remotely-controlled precipitation and filtration operations. Liquid within a precipitation chamber is maintained above a porous member by introducing air beneath the member; pressure beneath the porous member is reduced to suck the liquid through the member and effect filtration.

  16. Low-temperature Storage of Cucumbers Induces Changes in the Organic Acid Content and in Citrate Synthase Activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To elucidate the cause of reported pyruvate accumulation in chilled stored cucumbers (Cucumis sativus L.) cv. ‘Toppugurin’, we have examined differences in the extent of incorporation of acetate-1,2-14C into the tricarboxylic acid (TCA) cycle and the specific activity of the enzyme citrate synthase ...

  17. Encoding information into precipitation structures

    NASA Astrophysics Data System (ADS)

    Martens, Kirsten; Bena, Ioana; Droz, Michel; Rácz, Zoltan

    2008-12-01

    Material design at submicron scales would be profoundly affected if the formation of precipitation patterns could be easily controlled. It would allow the direct building of bulk structures, in contrast to traditional techniques which consist of removing material in order to create patterns. Here, we discuss an extension of our recent proposal of using electrical currents to control precipitation bands which emerge in the wake of reaction fronts in A+ + B- → C reaction-diffusion processes. Our main result, based on simulating the reaction-diffusion-precipitation equations, is that the dynamics of the charged agents can be guided by an appropriately designed time-dependent electric current so that, in addition to the control of the band spacing, the width of the precipitation bands can also be tuned. This makes straightforward the encoding of information into precipitation patterns and, as an amusing example, we demonstrate the feasibility by showing how to encode a musical rhythm.

  18. Studies on effective utilization of precipitates from neutralized mine drainage

    SciTech Connect

    Harada, Taneomi

    1995-12-31

    Mine drainage has high acidity and sometimes contains more than the allowable concentration of ionized iron. In such a case, mine drainage is neutralized with calcium carbonate and calcium hydroxide to separate precipitates, such as the iron hydroxide and gypsum generated. Currently, most of these precipitates are not utilized and are accumulated in tailing dams. As a result, the service life of the tailing dams is reduced. This becomes a matter of concern, since securing sites for such dams is difficult. A most effective means of solving this problem would be to promote utilization of these neutralized precipitates. This paper reports on the results of studies on neutralized precipitates produced at the old Matsuo Mine (Iwate Prefecture), which has the largest neutralization treatment facility in Japan. As a result of the studies, the following was proposed regarding application of neutralized precipitates. Utilization as ferrite: mix ferrous hydroxide and ferric hydroxide in water to synthesize magnetite-like ferrite, to be used in the manufacture of magnetic markers for a mobility support system for blind pedestrians, or in producing magnetic fluids for sink-and-float separation of nonmagnetic metals and nonmetals. Utilization as hematite: bake ferric hydroxide to produce hematite, thereby extracting metallic iron for paint pigment as well as for the manufacture of ironware by local industry. Production of aluminum sulfate: precipitate aluminum ions from water and add sulfuric acid to produce aluminum sulfate.

  19. Systems-level metabolic flux profiling elucidates a complete, bifurcated tricarboxylic acid cycle in Clostridium acetobutylicum.

    PubMed

    Amador-Noguez, Daniel; Feng, Xiao-Jiang; Fan, Jing; Roquet, Nathaniel; Rabitz, Herschel; Rabinowitz, Joshua D

    2010-09-01

    Obligatory anaerobic bacteria are major contributors to the overall metabolism of soil and the human gut. The metabolic pathways of these bacteria remain, however, poorly understood. Using isotope tracers, mass spectrometry, and quantitative flux modeling, here we directly map the metabolic pathways of Clostridium acetobutylicum, a soil bacterium whose major fermentation products include the biofuels butanol and hydrogen. While genome annotation suggests the absence of most tricarboxylic acid (TCA) cycle enzymes, our results demonstrate that this bacterium has a complete, albeit bifurcated, TCA cycle; oxaloacetate flows to succinate both through citrate/alpha-ketoglutarate and via malate/fumarate. Our investigations also yielded insights into the pathways utilized for glucose catabolism and amino acid biosynthesis and revealed that the organism's one-carbon metabolism is distinct from that of model microbes, involving reversible pyruvate decarboxylation and the use of pyruvate as the one-carbon donor for biosynthetic reactions. This study represents the first in vivo characterization of the TCA cycle and central metabolism of C. acetobutylicum. Our results establish a role for the full TCA cycle in an obligatory anaerobic organism and demonstrate the importance of complementing genome annotation with isotope tracer studies for determining the metabolic pathways of diverse microbes.

  20. Estimation of continental precipitation recycling

    NASA Technical Reports Server (NTRS)

    Brubaker, Kaye L.; Entekhabi, Dara; Eagleson, P. S.

    1993-01-01

    The total amount of water that precipitates on large continental regions is supplied by two mechanisms: 1) advection from the surrounding areas external to the region and 2) evaporation and transpiration from the land surface within the region. The latter supply mechanism is tantamount to the recycling of precipitation over the continental area. The degree to which regional precipitation is supplied by recycled moisture is a potentially significant climate feedback mechanism and land surface-atmosphere interaction, which may contribute to the persistence and intensification of droughts. Gridded data on observed wind and humidity in the global atmosphere are used to determine the convergence of atmospheric water vapor over continental regions. A simplified model of the atmospheric moisture over continents and simultaneous estimates of regional precipitation are employed to estimate, for several large continental regions, the fraction of precipitation that is locally derived. The results indicate that the contribution of regional evaporation to regional precipitation varies substantially with location and season. For the regions studied, the ratio of locally contributed to total monthly precipitation generally lies between 0. 10 and 0.30 but is as high as 0.40 in several cases.

  1. What Is Acid Rain?

    ERIC Educational Resources Information Center

    Likens, Gene E.

    2004-01-01

    Acid rain is the collective term for any type of acidified precipitation: rain, snow, sleet, and hail, as well as the presence of acidifying gases, particles, cloud water, and fog in the atmosphere. The increased acidity, primarily from sulfuric and nitric acids, is generated as a by-product of the combustion of fossil fuels such as coal and oil.…

  2. Purple bamboo salt has anticancer activity in TCA8113 cells in vitro and preventive effects on buccal mucosa cancer in mice in vivo.

    PubMed

    Zhao, Xin; Deng, Xiaoxiao; Park, Kun-Young; Qiu, Lihua; Pang, Liang

    2013-02-01

    Bamboo salt is a traditional healthy salt known in Korea. The in vitro anticancer effects of the salt were evaluated using a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay in TCA8113 human tongue carcinoma cells. At 1% concentration, the growth inhibitory rate of purple bamboo salt was 61% higher than that of sea salt (27%). Apoptosis analysis of the cancer cells was carried out using 4,6-diamidino-2-phenylindole (DAPI) staining to investigate the mechanism of the anticancer effects in tongue carcinoma cells. Purple bamboo salt induced a stronger apoptotic effect than sea salt. An Institute of Cancer Research (ICR) mouse buccal mucosa cancer model was established by injecting mice with U14 squamous cell carcinoma cells. Following injection, the wound at the injection site was smeared with salt samples. It was observed that the tumor volumes for the group treated with purple bamboo salt were smaller than those from the sea salt treatment and control groups. The sections of buccal mucosa cancer tissue showed that canceration in the purple bamboo salt group was weaker compared with that in the sea salt group. Similar results were observed in the lesion section of the cervical lymph. Using reverse transcription-polymerase chain reaction (RT-PCR) and western blotting, the purple bamboo salt group demonstrated an increase in Bcl-2-associated X protein (Bax) and a decrease in B cell lymphoma-2 (Bcl-2), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, compared with the sea salt and control groups. The results demonstrated that purple bamboo salt had improved in vivo buccal mucosa cancer preventive activity compared with sea salt in mice.

  3. Precipitation Measurements from Space: The Global Precipitation Measurement Mission

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.

    2007-01-01

    Water is fundamental to the life on Earth and its phase transition between the gaseous, liquid, and solid states dominates the behavior of the weather/climate/ecological system. Precipitation, which converts atmospheric water vapor into rain and snow, is central to the global water cycle. It regulates the global energy balance through interactions with clouds and water vapor (the primary greenhouse gas), and also shapes global winds and dynamic transport through latent heat release. Surface precipitation affects soil moisture, ocean salinity, and land hydrology, thus linking fast atmospheric processes to the slower components of the climate system. Precipitation is also the primary source of freshwater in the world, which is facing an emerging freshwater crisis in many regions. Accurate and timely knowledge of global precipitation is essential for understanding the behavior of the global water cycle, improving freshwater management, and advancing predictive capabilities of high-impact weather events such as hurricanes, floods, droughts, and landslides. With limited rainfall networks on land and the impracticality of making extensive rainfall measurements over oceans, a comprehensive description of the space and time variability of global precipitation can only be achieved from the vantage point of space. This presentation will examine current capabilities in space-borne rainfall measurements, highlight scientific and practical benefits derived from these observations to date, and provide an overview of the multi-national Global Precipitation Measurement (GPM) Mission scheduled to bc launched in the early next decade.

  4. Non-precipitating cumulus cloud study

    SciTech Connect

    Alkezweeny, A.J.

    1984-10-01

    This document describes the field experiment that was conducted in Kentucky during the period from July 20 to August 24, 1983. The objectives were to determine the vertical transport of acidic pollutants by cumulus convection and formation of acidic substances in non-precipitating clouds. The study is a research component of Task Group C (Atmospheric Processes) of the National Acid Precipitation Assessment Program. To examine the vertical transport, an SF/sub 6/ tracer was released from one aircraft, sampled by another aircraft, and sampled on the ground. The results show that pollutants from the boundary layer are lifted to the cloud layer. From there, they are intermittently transported both to the ground and to higher elevations, possibly in the vertical updrafts of towering cumulus clouds. A series of instrumented aircraft flights around the clouds were conducted to study the formation of acidic aerosols. The concentrations of SO/sub 2/, SO/sub 4/, NO/sub 3/, NH/sub 4/, NH/sub 3/, HNO/sub 3/ and trace metals were measured by filter techniques. Furthermore, NO/sub x/, O/sub 3/, light scattering, and basic meteorological parameters were measured in real-time. Detailed chemical composition of aerosols and NH/sub 3/ was also measured on the ground. Preliminary results show that the molar ratio of SO/sub 2//SO/sub 2/ + SO/sub 4/) at cloud tops is higher than at cloud bases. This indicates that sulfate aerosols were formed in the clouds. The NH/sub 3/ concentration shows higher values at nighttime than daytime and decreases sharply with increasing altitude. 3 references.

  5. Co-precipitation of dissolved organic matter by calcium carbonate in Pyramid Lake, Nevada

    USGS Publications Warehouse

    Leenheer, Jerry A.; Reddy, Michael M.

    2008-01-01

    Our previous research has demonstrated that dissolved organic matter (DOM) influences calcium carbonate mineral formation in surface and ground water. To better understand DOM mediation of carbonate precipitation and DOM co-precipitation and/or incorporation with carbonate minerals, we characterized the content and speciation of DOM in carbonate minerals and in the lake water of Pyramid Lake, Nevada, USA. A 400-gram block of precipitated calcium carbonate from the Pyramid Lake shore was dissolved in 8 liters of 10% acetic acid. Particulate matter not dissolved by acetic acid was removed by centrifugation. DOM from the carbonate rock was fractionated into nine portions using evaporation, dialysis, resin adsorption, and selective precipitations to remove acetic acid and inorganic constituents. The calcium carbonate rock contained 0.23% DOM by weight. This DOM was enriched in polycarboxylic proteinaceous acids and hydroxy-acids in comparison with the present lake water. DOM in lake water was composed of aliphatic, alicyclic polycarboxylic acids. These compound classes were found in previous studies to inhibit calcium carbonate precipitation. DOM fractions from the carbonate rock were 14C-age dated at about 3,100 to 3,500 years before present. The mechanism of DOM co-precipitation and/or physical incorporation in the calcium carbonate is believed to be due to formation of insoluble calcium complexes with polycarboxylic proteinaceous acids and hydroxy-acids that have moderately large stability constants at the alkaline pH of the lake. DOM co-precipitation with calcium carbonate and incorporation in precipitated carbonate minerals removes proteinaceous DOM, but nearly equivalent concentrations of neutral and acidic forms of organic nitrogen in DOM remain in solution. Calcium carbonate precipitation during lime softening pretreatment of drinking water may have practical applications for removal of proteinaceous disinfection by-product precursors.

  6. Identifying Anomality in Precipitation Processes

    NASA Astrophysics Data System (ADS)

    Jiang, P.; Zhang, Y.

    2014-12-01

    Safety, risk and economic analyses of engineering constructions such as storm sewer, street and urban drainage, and channel design are sensitive to precipitation storm properties. Whether the precipitation storm properties exhibit normal or anomalous characteristics remains obscure. In this study, we will decompose a precipitation time series as sequences of average storm intensity, storm duration and interstorm period to examine whether these sequences could be treated as a realization of a continuous time random walk with both "waiting times" (interstorm period) and "jump sizes" (average storm intensity and storm duration). Starting from this viewpoint, we will analyze the statistics of storm duration, interstorm period, and average storm intensity in four regions in southwestern United States. We will examine whether the probability distribution is temporal and spatial dependent. Finally, we will use fractional engine to capture the randomness in precipitation storms.

  7. Evaluation of Coupled Precipitator Two

    SciTech Connect

    Stone, M.E.

    1999-11-08

    The offline testing of the Coupled Precipitator Two (CP-2) has been completed. The tests were conducted and are documented. The tests were conducted at an offline test rack near the Drain Tube Test Stand facility in 672-T.

  8. WEATHER_Layered-Precipitable-Water

    Atmospheric Science Data Center

    2016-06-23

    ... TOVS (HIRS) clear sky radiances Radiosonde GPS (after 1995) AIRS Level 2 TPW and Layered PW Spatial ... Parameters:  Precipitable Water Order Data:  Earthdata Search:  Earthdata Search SCAR-B ...

  9. WEATHER_Total-Precipitable-Water

    Atmospheric Science Data Center

    2016-06-23

    ... TOVS (HIRS) clear sky radiances Radiosonde GPS (after 1995) AIRS Level 2 TPW and Layered PW Spatial ... Parameters:  Precipitable Water Order Data:  Earthdata Search:  Earthdata Search SCAR-B ...

  10. Environmental Radioactivity, Temperature, and Precipitation.

    ERIC Educational Resources Information Center

    Riland, Carson A.

    1996-01-01

    Reports that environmental radioactivity levels vary with temperature and precipitation and these effects are due to radon. Discusses the measurement of this environmental radioactivity and the theory behind it. (JRH)

  11. Silica Precipitation and Lithium Sorption

    SciTech Connect

    Jay Renew

    2015-09-20

    This file contains silica precipitation and lithium sorption data from the project. The silica removal data is corrected from the previous submission. The previous submission did not take into account the limit of detection of the ICP-MS procedure.

  12. Atmospheric science: Energy and precipitation

    NASA Astrophysics Data System (ADS)

    Donohoe, Aaron

    2016-12-01

    The latitude of the tropical rainbelt is constrained by the energy balance between hemispheres. An expansion of this theory that includes longitudinal variations of atmospheric heating can predict regional changes in tropical precipitation.

  13. The 2014 Silba Precipitation Extreme

    NASA Astrophysics Data System (ADS)

    Rasol, Dubravka; Ólafsson, Haraldur

    2015-04-01

    On 30 July 2014 a 24 h precipitation record of 218 mm was set at the island of Silba in the N-Adriatic Sea. The precipitation was of convective nature and significantly less precipitation was recorded only small distances away, at the coast of mainland Croatia. The event is reproduced numerically and discussed in terms of dynamics and predictability. On a large scale, the precipitation extreme was associated with a slow-moving upper tropospheric low that formed over the N-Atlantic several days earlier. At lower levels, there were humid mediterranean airmasses. On a smaller scale, there are indications that the extreme convection may have been triggered by an orographic disturbance.

  14. Extraction, purification, methylation and GC-MS analysis of short-chain carboxylic acids for metabolic flux analysis.

    PubMed

    Tivendale, Nathan D; Jewett, Erin M; Hegeman, Adrian D; Cohen, Jerry D

    2016-08-15

    Dynamic metabolic flux analysis requires efficient and effective methods for extraction, purification and analysis of a plethora of naturally-occurring compounds. One area of metabolism that would be highly informative to study using metabolic flux analysis is the tricarboxylic acid (TCA) cycle, which consists of short-chain carboxylic acids. Here, we describe a newly-developed method for extraction, purification, derivatization and analysis of short-chain carboxylic acids involved in the TCA cycle. The method consists of snap-freezing the plant material, followed by maceration and a 12-15h extraction at -80 °C. The extracts are then subject to reduction (to stabilize β-keto acids), purified by strong anion exchange solid phase extraction and methylated with methanolic HCl. This method could also be readily adapted to quantify many other short-chain carboxylic acids.

  15. Oceanic Precipitation Measurement - Surface Validation

    NASA Astrophysics Data System (ADS)

    Klepp, Christian

    2013-04-01

    State-of-the-art satellite derived and reanalysis based precipitation climatologies still show remarkably large differences in frequency, amount, intensity, variability and temporal behavior of precipitation over the oceans. Additionally so far appropriate in-situ validation instruments were not available for shipboard use. The uncertainties are largest for light precipitation within the ITCZ and subtropics and for cold season high-latitude precipitation including mix-phase and snowfall. Hence, a long-term issue on which IPWG and GPM-GV is urging more attention is the provision of high quality surface validation data in oceanic areas using innovative ship-based instruments. Precipitation studies would greatly benefit from systematic dataset collection and analysis as such data could also be used to constrain precipitation retrievals. To achieve this goal, the KlimaCampus and Max Planck Institute for Meteorology in Hamburg, Germany funded this project that uses automated shipboard optical disdrometers, called Eigenbrodt ODM470, that are capable of measuring liquid and solid precipitation using drop size distributions in minute intervals on moving ships with high accuracy even under high wind speeds and rough sea states. Since the project start in 2009 the statistical basis for a conclusive validation has significantly improved with comprehensive data collection of more than 3 million minutes of precipitation measurements onboard six ships. Currently, six ODM470 instrument systems are available of which three are long-term mounted onboard the German research icebreaker R/V Polarstern (Alfred Wegner Institut) since June 2010, on R/V Akademik Ioffe (P.P.Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia) since September 2010 and on R/V Maria S. Merian (Brise Research, University of Hamburg) since December 2011. Three instruments are used for additional short-term shipboard campaigns and intercomparison projects. The core regions for these

  16. Precipitation of DNA with Ethanol.

    PubMed

    Green, Michael R; Sambrook, Joseph

    2016-12-01

    DNA can be precipitated out of solution for the removal of salts and/or for resuspension in an alternative buffer. Either ethanol or isopropanol can be used to achieve this purpose; however, the use of ethanol is generally preferred. Cations, provided as salts, are typically included to neutralize the negative charge of the DNA phosphate backbone. This method describes ethanol precipitation of DNA in microcentrifuge tubes.

  17. Ticarcillin-clavulanic acid plus amikacin versus ceftazidime plus amikacin in the empirical treatment of fever in acute leukemia: a prospective randomized trial.

    PubMed

    Fanci, R; Paci, C; Leoni, F; Casini, C; Longo, G

    2003-06-01

    We evaluated the efficacy of ticarcillin-clavulanic acid plus amikacin (TCA) with ceftazidime plus amikacin (CFA) as empiric therapy of fever in acute leukemia in a total of 127 episodes. The overall success rate of the therapy (survival) was 93% in TCA group and 92% in CFA group. Success without therapy modifications (afebrile at 72 hours) was 39% for TCA, 31% for CFA; success with modifications was 55% and 61% respectively. Failure (death due to documented or presumed infection) was 6% for TCA and 8% for CFA. Differences were not statistically significant. The success without modifications was higher in the group of patients with fever of unknown origin (FUO) than in documented infections (DI), mainly with CFA. No differences were documented in the resistance rate and in clinical outcome during severe neutropenia (ANC <100 microl). In our experience TCA is as effective as CFA as first-line treatment in severe neutropenic patients with acute leukemia, although in both regimens patients with DI are likely to require modifications in treatment.

  18. Highly sensitive amperometric sensor for micromolar detection of trichloroacetic acid based on multiwalled carbon nanotubes and Fe(II)-phtalocyanine modified glassy carbon electrode.

    PubMed

    Kurd, Masoumeh; Salimi, Abdollah; Hallaj, Rahman

    2013-04-01

    A highly sensitive electrochemical sensor for the detection of trichloroacetic acid (TCA) is developed by subsequent immobilization of phthalocyanine (Pc) and Fe(II) onto multiwalled carbon nanotubes (MWCNTs) modified glassy carbon (GC) electrode. The GC/MWCNTs/Pc/Fe(II) electrode showed a pair of well-defined and nearly reversible redox couple correspondent to (Fe(III)Pc/Fe(II)Pc) with surface-confined characteristics. The surface coverage (Γ) and heterogeneous electron transfer rate constant (ks) of immobilized Fe(II)-Pc were calculated as 1.26×10(-10) mol cm(-2) and 28.13 s(-1), respectively. Excellent electrocatalytic activity of the proposed GC/MWCNTs/Pc/Fe(II) system toward TCA reduction has been indicated and the three consequent irreversible peaks for electroreduction of CCl3COOH to CH3COOH have been clearly seen. The observed chronoamperometric currents are linearly increased with the concentration of TCA at concentration range up to 20mM. Detection limit and sensitivity of the modified electrode were 2.0 μM and 0.10 μA μM(-1) cm(-2), respectively. The applicability of the sensor for TCA detection in real samples was tested. The obtained results suggest that the proposed system can serve as a promising electrochemical platform for TCA detection.

  19. Activation and attenuation of apoptosis of CD4+ T cells following in vivo exposure to two common environmental toxicants, trichloroacetaldehyde hydrate and trichloroacetic acid.

    PubMed

    Blossom, Sarah J; Pumford, Neil R; Gilbert, Kathleen M

    2004-11-01

    Exposure to occupationally relevant concentrations of the environmental pollutant, trichloroethylene (TCE), in the drinking water of autoimmune-prone MRL+/+ mice has been shown to promote the generation of lupus and autoimmune hepatitis in association with the activation of Interferon-gamma (IFN-gamma)-producing CD4+ T cells. Since blocking TCE metabolism suppressed the TCE-induced alteration in immune function, the present study was initiated to determine whether the major metabolites of TCE, trichloroacetaldehyde hydrate (TCAH) and trichloroacetic acid (TCA) could also mediate these immunoregulatory affects in vivo. TCAH and TCA were administered to the drinking water of MRL+/+ mice for 4 weeks. CD4+ T cells from TCAH and TCA-treated MRL+/+ mice, unlike CD4+ T cells from control mice, demonstrated functional and phenotypic signs of activation, as evidenced by increased IFN-gamma production in association with the increased percentage of CD62L(lo) CD4+ T cells. Interestingly, it was also found that the CD4+ T cells from the TCAH and TCA-treated mice showed a decreased susceptibility to the activation-induced cell death (AICD) form of apoptosis following re-stimulation in vitro. By demonstrating that TCAH and TCA can activate CD4+ T cells and inhibit their apoptosis following in vivo exposure represents a mechanism by which environmental toxicants may induce or accelerate the development of autoimmune disease.

  20. Composition of precipitation in remote areas of the world

    SciTech Connect

    Galloway, J.N.; Likens, G.E.; Keene, W.C.; Miller, J.M.

    1982-10-20

    The Global Precipitation Chemistry Project collects precipitation by event to determine composition and processes controlling it in five remote areas. Compositions (excluding seasalt) at St. Georges, Bermuda, were primarily controlled by anthropogenic processes; compositions and acidities at San Carlos, Venezuela, Katherine, Australia, Poker, Flat, Alaska, and Amsterdam Island were controlled by unknown mixtures of natural or anthropogenic processes. Precipitation was acidic; average volume-weighted pH values were 4.8 for Bermuda; 5.0, Alaska; 4.9, Amsterdam Island; 4.8, Australia; 4.8, Venezuela. Acidities at Bermuda and Alaska were from long-range transport of sulfate aerosol; at Venezuela, Australia, and Amsterdam Island, from mixtures of weak organic and strong mineral acids, primarily H/sub 2/SO/sub 4/. Relative proportions of weak to strong acids were largest at Venezuela and lowest at Amsterdam Island. Weak and strong acids were from mixtures of natural and anthropogenic processes. Once contributions from human activities were removed, the lower limit of natural contributions was probably > or =pH 5.

  1. Composition of precipitation in remote areas of the world

    SciTech Connect

    Galloway, J.N.; Likens, G.E.; Keene, W.C.; Miller, J.M.

    1982-10-20

    The Global Precipitation Chemistry Project collects precipitation by event to determine composition and processes controlling it in five remote areas. Compositions (excluding sea-salt) at St. Georges, Bermuda, were primarily controlled by anthropogenic processes; composition and acidities at San Carlos, Venezuela, Katherine, Australia, Poker Flat, Alaska, and Amsterdam Island were controlled by unknown mixtures of natural or anthropogenic processes. Precipitation was acidic; average volume-weighted pH values were 4.8 for Bermuda; 5.0, Alaska; 4.9, Amsterdam Island; 4.8, Australia; 4.8, Venezuela. Acidities at Bermuda and Alaska were from long-range transport of sulfate aerosol; at Venezuela, Australia, and Amsterdam Island, from mixtures of weak organic and strong mineral acids, primarily H/sub 2/SO/sub 4/. Relative proportions of weak to strong acids were largest at Venezuela and lowest at Amsterdam Island. Weak and strong acids were from mixtures of natural and anthropogenic processes. Once contributions from human activities were removed, the lower limit of natural contributions was probably greater than or equal to pH 5.

  2. NASA Dual Precipitation Radar Arrives at Goddard

    NASA Video Gallery

    The Dual-frequency Precipitation Radar (DPR) built by the Japan Aerospace Exploration Agency (JAXA) for the Global Precipitation Measurement (GPM) mission's Core Observatory arrived on Friday, Marc...

  3. Advanced Microwave Precipitation Radiometer (AMPR) for remote observation of precipitation

    NASA Technical Reports Server (NTRS)

    Galliano, J. A.; Platt, R. H.

    1990-01-01

    The design, development, and tests of the Advanced Microwave Precipitation Radiometer (AMPR) operating in the 10 to 85 GHz range specifically for precipitation retrieval and mesoscale storm system studies from a high altitude aircraft platform (i.e., ER-2) are described. The primary goals of AMPR are the exploitation of the scattering signal of precipitation at frequencies near 10, 19, 37, and 85 GHz together to unambiguously retrieve precipitation and storm structure and intensity information in support of proposed and planned space sensors in geostationary and low earth orbit, as well as storm-related field experiments. The development of AMPR will have an important impact on the interpretation of microwave radiances for rain retrievals over both land and ocean for the following reasons: (1) A scanning instrument, such as AMPR, will allow the unambiguous detection and analysis of features in two dimensional space, allowing an improved interpretation of signals in terms of cloud features, and microphysical and radiative processes; (2) AMPR will offer more accurate comparisons with ground-based radar data by feature matching since the navigation of the ER-2 platform can be expected to drift 3 to 4 km per hour of flight time; and (3) AMPR will allow underflights of the SSM/I satellite instrument with enough spatial coverage at the same frequencies to make meaningful comparisons of the data for precipitation studies.

  4. Development of an HPLC-fluorescence determination method for carboxylic acids related to the tricarboxylic acid cycle as a metabolome tool.

    PubMed

    Kubota, Kazuyuki; Fukushima, Takeshi; Yuji, Reiko; Miyano, Hiroshi; Hirayama, Kazuo; Santa, Tomofumi; Imai, Kazuhiro

    2005-12-01

    We report the simultaneous determination of the carboxylic acids related to the tricarboxylic acid (TCA) cycle, which plays an important role in producing adenosine triphosphate (ATP) and generating energy in mitochondria. Seven carboxylic acids from the TCA cycle, and pyruvic acid and 2-methylsuccinic acid, as an internal standard, were derivatized with a fluorescent reagent for carboxyl groups, 4-N,N-dimethylaminosulfonyl-7-piperazino-2,1,3-benzoxadiazole (DBD-PZ), in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 4-N,N-dimethyaminopyridine as the coupling reagents, at 60 degrees C for 120 min. Subsequently, the excess DBD-PZ was removed efficiently using a cation-exchange cartridge, SDB-RPS (Empore). These fluorescent derivatives were separated well from each other on an octadecyl silica column (TSKgel ODS-80Ts, 250 x 4.6 mm, i.d.) with an eluent of acetonitrile-water containing 1% formic acid at a flow rate of 0.8 mL/min, and were detected fluorometrically at 560 nm, with excitation at 450 nm. The validation data were satisfactory in the range of 2.5-100 microm citric acid, isocitric acid, 2-oxoglutaric acid, succinic acid and fumaric acid. The detection limit (S/N = 3) for citric acid was 2 fmol on the column. The structures of these derivatives were confirmed by high-performance liquid chromatography-mass spectrometry, which proved that their carboxylic groups were completely labeled with DBD-PZ, except for oxaloacetic acid. This HPLC method was successfully applied to the analysis of TCA cycle metabolites in rat urine. The method will also be useful for metabolome research, such as for target analyses of metabolites with carboxyl groups, not only in urine but also in cells and organs.

  5. Chemical Data for Precipitate Samples

    USGS Publications Warehouse

    Foster, Andrea L.; Koski, Randolph A.

    2008-01-01

    During studies of sulfide oxidation in coastal areas of Prince William Sound in 2005, precipitate samples were collected from onshore and intertidal locations near the Ellamar, Threeman, and Beatson mine sites (chapter A, fig. 1; table 7). The precipitates include jarosite and amorphous Fe oxyhydroxide from Ellamar, amorphous Fe oxyhydroxide from Threeman, and amorphous Fe oxyhydroxide, ferrihydrite, and schwertmannite from Beatson. Precipitates occurring in the form of loose, flocculant coatings were harvested using a syringe and concentrated in the field by repetitive decanting. Thicker accumulations were either scraped gently from rocks using a stainless steel spatula or were scooped directly into receptacles (polyethylene jars or plastic heavy-duty zippered bags). Most precipitate samples contain small amounts of sedimentary detritus. With three jarosite-bearing samples from Ellamar, an attempt was made to separate the precipitate from the heavy-mineral fraction of the sediment. In this procedure, the sample was stirred in a graduated cylinder containing deionized water. The jarosite-rich suspension was decanted onto analytical filter paper and air dried before analysis. Eleven precipitate samples from the three mine sites were analyzed in laboratories of the U.S. Geological Survey (USGS) in Denver, Colorado (table 8). Major and trace elements were determined by inductively coupled plasma-mass spectrometry following multiacid (HCl-HNO3-HClO4-HF) digestion (Briggs and Meier, 2002), except for mercury, which was analyzed by cold-vapor atomic absorption spectroscopy (Brown and others, 2002a). X-ray diffraction (XRD) analyses were performed on powdered samples (<200 mesh) by S. Sutley of the USGS. Additional details regarding sample preparation and detection limits are found in Taggert (2002). Discussions of the precipitate chemistry and associated microbial communities are presented in Koski and others (2008) and Foster and others (2008), respectively.

  6. Glutamate is the major anaplerotic substrate in the tricarboxylic acid cycle of isolated rumen epithelial and duodenal mucosal cells from beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study aimed to determine the contribution of substrates to tricarboxylic acid (TCA) cycle fluxes in rumen epithelial (REC) and duodenal mucosal (DMC) cells isolated from bulls (n = 6) fed either a 75% forage (HF) or 75% concentrate (HC) diet. In separate incubations, [13C6]glucose, [13C5]glutam...

  7. Acid Rain. LC Science Tracer Bullet.

    ERIC Educational Resources Information Center

    Hollmann, Pauline, Comp.

    The term "acid rain," also called "acid precipitation," generally refers to any precipitation having a pH value of less than 5.6. This guide to the literature on acid rain in the collections of the Library of Congress is not necessarily intended to be a comprehensive bibliography. It is designed to provide the reader with a set…

  8. Dust particles precipitation in AC/DC electrostatic precipitator

    NASA Astrophysics Data System (ADS)

    Jaworek, A.; Marchewicz, A.; Krupa, A.; Sobczyk, A. T.; Czech, T.; Antes, T.; Śliwiński, Ł.; Kurz, M.; Szudyga, M.; Rożnowski, W.

    2015-10-01

    Submicron and nanoparticles removal from flue or exhaust gases remain still a challenge for engineers. The most effective device used for gas cleaning in power plants or industry is electrostatic precipitator, but its collection efficiency steeply decreases for particles smaller than 1 micron. In this paper, fractional collection efficiency of two-stage electrostatic precipitator comprising of alternating electric field charger and DC supplied parallel-plate collection stage has been investigated. The total number collection efficiency for PM2.5 particles was higher than 95% and mass collection efficiency >99%. Fractional collection efficiency for particles between 300 nm and 1 μm was >95%.

  9. Are hourly precipitation extremes increasing faster than daily precipitation extremes?

    NASA Astrophysics Data System (ADS)

    Barbero, Renaud; Fowler, Hayley; Blenkinsop, Stephen; Lenderink, Geert

    2016-04-01

    Extreme precipitation events appear to be increasing with climate change in many regions of the world, including the United States. These extreme events have large societal impacts, as seen during the recent Texas-Oklahoma flooding in May 2015 which caused several billion in damages and left 47 deaths in its path. Better understanding of past changes in the characteristics of extreme rainfall events is thus critical for reliable projections of future changes. Although it has been documented in several studies that daily precipitation extremes are increasing across parts of the contiguous United States, very few studies have looked at hourly extremes. However, this is of primary importance as recent studies on the temperature scaling of extreme precipitation have shown that increases above the Clausius-Clapeyron (~ 7% °C-1) are possible for hourly precipitation. In this study, we used hourly precipitation data (HPD) from the National Climatic Data Center and extracted more than 1,000 stations across the US with more than 40 years of data spanning the period 1950-2010. As hourly measurements are often associated with a range of issues, the data underwent multiple quality control processes to exclude erroneous data. While no significant changes were found in annual maximum precipitation using both hourly and daily resolution datasets, significant increasing trends in terms of frequency of episodes exceeding present-day 95th percentiles of wet hourly/daily precipitation were observed across a significant portion of the US. The fraction of stations with significant increasing trends falls outside the confidence interval range during all seasons but the summer. While less than 12% of stations exhibit significant trends at the daily scale in the wintertime, more than 45% of stations, mostly clustered in central and Northern United States, show significant increasing trends at the hourly scale. This suggests that short-duration storms have increased faster than daily

  10. The Global Precipitation Measurement Mission

    NASA Astrophysics Data System (ADS)

    Jackson, Gail

    2014-05-01

    The Global Precipitation Measurement (GPM) mission's Core satellite, scheduled for launch at the end of February 2014, is well designed estimate precipitation from 0.2 to 110 mm/hr and to detect falling snow. Knowing where and how much rain and snow falls globally is vital to understanding how weather and climate impact both our environment and Earth's water and energy cycles, including effects on agriculture, fresh water availability, and responses to natural disasters. The design of the GPM Core Observatory is an advancement of the Tropical Rainfall Measuring Mission (TRMM)'s highly successful rain-sensing package [3]. The cornerstone of the GPM mission is the deployment of a Core Observatory in a unique 65o non-Sun-synchronous orbit to serve as a physics observatory and a calibration reference to improve precipitation measurements by a constellation of 8 or more dedicated and operational, U.S. and international passive microwave sensors. The Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR will provide measurements of 3-D precipitation structures and microphysical properties, which are key to achieving a better understanding of precipitation processes and improving retrieval algorithms for passive microwave radiometers. The combined use of DPR and GMI measurements will place greater constraints on possible solutions to radiometer retrievals to improve the accuracy and consistency of precipitation retrievals from all constellation radiometers. Furthermore, since light rain and falling snow account for a significant fraction of precipitation occurrence in middle and high latitudes, the GPM instruments extend the capabilities of the TRMM sensors to detect falling snow, measure light rain, and provide, for the first time, quantitative estimates of microphysical properties of precipitation particles. The GPM Core Observatory was developed and tested at NASA

  11. SEPARATION OF FISSION PRODUCT VALUES FROM THE HEXAVALENT PLUTONIUM BY CARRIER PRECIPITATION

    DOEpatents

    Davies, T.H.

    1959-12-15

    An improved precipitation of fission products on bismuth phosphate from an aqueous mineral acid solution also containing hexavalent plutonium by incorporating, prior to bismuth phosphate precipitation, from 0.05 to 2.5 grams/ liter of zirconium phosphate, niobium oxide. and/or lanthanum fluoride is described. The plutonium remains in solution.

  12. Solar wind precipitation on Mars

    NASA Astrophysics Data System (ADS)

    Stenberg, G.; Dieval, C.; Nilsson, H.; Kallio, E.; Barabash, S.; Futaana, Y.; Shematovich, V.; Bisikalo, D.

    2011-10-01

    We have found that solar wind particles frequently precipitate onto the atmosphere of Mars [1,2]. The precipitating particles contribute to the energy and matter flux into the ionosphere. We use ion data from the ASPERA-3 instrument onboard Mars Express to investigate the precipitation patterns, processes and the total transfer of energy and matter from the solar wind to the atmosphere. The main reason for the proton and alpha particle precipitation is likely the large gyroradii of hot particles compared to the size of the induced magnetosphere/magnetic barrier. We find that the particle penetration depends on the direction of the convection electric field in the solar wind but that the crustal magnetic fields have very little influence. The total energy flux is low compared to the solar radiation heating on the dayside, but a significant energy source on the nightside. We also believe that the solar wind alphaparticles precipitating into the atmosphere is an important source of the neutral helium in the Martian atmosphere. We combine our observations with computer modeling [3,4]. We have applied a Direct Simulation Monte Carlo method to solve the kinetic equation for the H/H+ transport in the upper Martian atmosphere including CO2, N2 and O. We conclude that the induced magnetic field around Mars plays the crucial role in the transport of charged particles in the upper atmosphere, and it determines the energy deposition of the solar wind.

  13. Brown Pine Leaf Extract and Its Active Component Trans-Communic Acid Inhibit UVB-Induced MMP-1 Expression by Targeting PI3K.

    PubMed

    Huh, Won Bum; Kim, Jong-Eun; Kang, Young-Gyu; Park, Gaeun; Lim, Tae-gyu; Kwon, Jung Yeon; Song, Da Som; Jeong, Eun Hee; Lee, Charles C; Son, Joe Eun; Seo, Sang Gwon; Lee, Eunjung; Kim, Jong Rhan; Lee, Chang Yong; Park, Jun Seong; Lee, Ki Won

    2015-01-01

    Japanese red pine (Pinus densiflora) is widely present in China, Japan, and Korea. Its green pine leaves have traditionally been used as a food as well as a coloring agent. After being shed, pine leaves change their color from green to brown within two years, and although the brown pine leaves are abundantly available, their value has not been closely assessed. In this study, we investigated the potential anti-photoaging properties of brown pine leaves for skin. Brown pine leaf extract (BPLE) inhibited UVB-induced matrix metalloproteinase-1 (MMP-1) expression to a greater extent than pine leaf extract (PLE) in human keratinocytes and a human skin equivalent model. HPLC analysis revealed that the quantity of trans-communic acid (TCA) and dehydroabietic acid (DAA) significantly increases when the pine leaf color changes from green to brown. BPLE and TCA elicited reductions in UVB-induced MMP-1 mRNA expression and activator protein-1 (AP-1) transactivation by reducing DNA binding activity of phospho-c-Jun, c-fos and Fra-1. BPLE and TCA also inhibited UVB-induced Akt phosphorylation, but not mitogen activated protein kinase (MAPK), known regulators of AP-1 transactivation. We additionally found that BPLE and TCA inhibited phosphoinositide 3-kinase (PI3K), the upstream kinase of Akt, in vitro. In summary, both BPLE and its active component TCA exhibit protective effects against UVB-induced skin aging. Taken together, these findings underline the potential for BPLE and TCA to be utilized as anti-wrinkling agents and cosmetic ingredients, as they suppress UVB-induced MMP-1 expression.

  14. Brown Pine Leaf Extract and Its Active Component Trans-Communic Acid Inhibit UVB-Induced MMP-1 Expression by Targeting PI3K

    PubMed Central

    Park, Gaeun; Lim, Tae-gyu; Kwon, Jung Yeon; Song, Da Som; Jeong, Eun Hee; Lee, Charles C.; Son, Joe Eun; Seo, Sang Gwon; Lee, Eunjung; Kim, Jong Rhan; Lee, Chang Yong; Park, Jun Seong; Lee, Ki Won

    2015-01-01

    Japanese red pine (Pinus densiflora) is widely present in China, Japan, and Korea. Its green pine leaves have traditionally been used as a food as well as a coloring agent. After being shed, pine leaves change their color from green to brown within two years, and although the brown pine leaves are abundantly available, their value has not been closely assessed. In this study, we investigated the potential anti-photoaging properties of brown pine leaves for skin. Brown pine leaf extract (BPLE) inhibited UVB-induced matrix metalloproteinase-1 (MMP-1) expression to a greater extent than pine leaf extract (PLE) in human keratinocytes and a human skin equivalent model. HPLC analysis revealed that the quantity of trans-communic acid (TCA) and dehydroabietic acid (DAA) significantly increases when the pine leaf color changes from green to brown. BPLE and TCA elicited reductions in UVB-induced MMP-1 mRNA expression and activator protein-1 (AP-1) transactivation by reducing DNA binding activity of phospho-c-Jun, c-fos and Fra-1. BPLE and TCA also inhibited UVB-induced Akt phosphorylation, but not mitogen activated protein kinase (MAPK), known regulators of AP-1 transactivation. We additionally found that BPLE and TCA inhibited phosphoinositide 3-kinase (PI3K), the upstream kinase of Akt, in vitro. In summary, both BPLE and its active component TCA exhibit protective effects against UVB-induced skin aging. Taken together, these findings underline the potential for BPLE and TCA to be utilized as anti-wrinkling agents and cosmetic ingredients, as they suppress UVB-induced MMP-1 expression. PMID:26066652

  15. Staphylococcus epidermidis Polysaccharide Intercellular Adhesin Production Significantly Increases during Tricarboxylic Acid Cycle Stress

    PubMed Central

    Vuong, Cuong; Kidder, Joshua B.; Jacobson, Erik R.; Otto, Michael; Proctor, Richard A.; Somerville, Greg A.

    2005-01-01

    Staphylococcal polysaccharide intercellular adhesin (PIA) is important for the development of a mature biofilm. PIA production is increased during growth in a nutrient-replete or iron-limited medium and under conditions of low oxygen availability. Additionally, stress-inducing stimuli such as heat, ethanol, and high concentrations of salt increase the production of PIA. These same environmental conditions are known to repress tricarboxylic acid (TCA) cycle activity, leading us to hypothesize that altering TCA cycle activity would affect PIA production. Culturing Staphylococcus epidermidis with a low concentration of the TCA cycle inhibitor fluorocitrate dramatically increased PIA production without impairing glucose catabolism, the growth rate, or the growth yields. These data lead us to speculate that one mechanism by which staphylococci perceive external environmental change is through alterations in TCA cycle activity leading to changes in the intracellular levels of biosynthetic intermediates, ATP, or the redox status of the cell. These changes in the metabolic status of the bacteria result in the attenuation or augmentation of PIA production. PMID:15838022

  16. The tricarboxylic acid cycle in Shewanella oneidensis is independent of Fur and RyhB control

    SciTech Connect

    Yang, Yunfeng; McCue, Lee Ann; Parsons, Andrea B.; Feng, Sheng; Zhou, Jizhong

    2010-10-26

    It is well established in E. coli and Vibrio cholerae that strains harboring mutations in the ferric uptake regulator gene (fur) are unable to utilize tricarboxylic acid (TCA) compounds, due to the down-regulation of key TCA cycle enzymes, such as AcnA and SdhABCD. This down-regulation is mediated by a Fur-regulated small regulatory RNA named RyhB. In this study, we showed that a fur deletion mutant of the γ-proteobacterium S. oneidensis could utilize TCA compounds. In addition, expression of the TCA cycle genes acnA and sdhA was not down-regulated in the mutant. To explore this observation further, we identified a ryhB gene in Shewanella species and demonstrated its expression experimentally. Further experiments suggested that RyhB was up-regulated in fur mutant, but that AcnA and SdhA were not controlled by RyhB. This work delineates an important difference of the Fur-RyhB regulatory cycle between S. oneidensis and other γ-proteobacteria.

  17. Improved proteomic analysis following trichloroacetic acid extraction of Bacillus anthracis spore proteins.

    PubMed

    Deatherage Kaiser, Brooke L; Wunschel, David S; Sydor, Michael A; Warner, Marvin G; Wahl, Karen L; Hutchison, Janine R

    2015-11-01

    Proteomic analysis of bacterial samples provides valuable information about cellular responses and functions under different environmental pressures. Analysis of cellular proteins is dependent upon efficient extraction from bacterial samples, which can be challenging with increasing complexity and refractory characteristics. While no single method can recover 100% of the bacterial proteins, selected protocols can improve overall protein isolation, peptide recovery, or enrichment for certain classes of proteins. The method presented here is technically simple, does not require specialized equipment such as a mechanical disrupter, and is effective for protein extraction of the particularly challenging sample type of Bacillus anthracis Sterne spores. The ability of Trichloroacetic acid (TCA) extraction to isolate proteins from spores and enrich for spore-specific proteins was compared to the traditional mechanical disruption method of bead beating. TCA extraction improved the total average number of proteins identified within a sample as compared to bead beating (547 vs 495, respectively). Further, TCA extraction enriched for 270 spore proteins, including those typically identified by first isolating the spore coat and exosporium layers. Bead beating enriched for 156 spore proteins more typically identified from whole spore proteome analyses. The total average number of proteins identified was equal using TCA or bead beating for easily lysed samples, such as B. anthracis vegetative cells. As with all assays, supplemental methods such as implementation of an alternative preparation method may simplify sample preparation and provide additional insight to the protein biology of the organism being studied.

  18. Energy metabolism and alginate biosynthesis in Pseudomonas aeruginosa: role of the tricarboxylic acid cycle.

    PubMed Central

    Schlictman, D; Kavanaugh-Black, A; Shankar, S; Chakrabarty, A M

    1994-01-01

    Infection with mucoid, alginate-producing strains of Pseudomonas aeruginosa is the leading cause of mortality among patients with cystic fibrosis. Alginate production by P. aeruginosa is not constitutive but is triggered by stresses such as starvation. The algR2 (also termed algQ) gene has been previously identified as being necessary for mucoidy; an algR2 mutant strain is unable to produce alginate when grown at 37 degrees C. We show here that the levels of phosphorylated succinyl coenzyme A synthetase (Scs) and nucleoside diphosphate kinase (Ndk), which form a complex in P. aeruginosa, are reduced in the algR2 mutant. We were able to correlate the lower level of phosphorylated Scs with a decrease in Scs activity. Western blots (immunoblots) also showed a decreased level of Ndk in the algR2 mutant, but the presence of another kinase activity sensitive to Tween 20 provides the missing Ndk function. The effect of AlgR2 on tricarboxylic acid (TCA) cycle enzymes appears to be specific for Scs, since none of the other TCA cycle enzymes measured showed a significant decrease in activity. Furthermore, the ability of the algR2 mutant to grow on TCA cycle intermediates, but not glucose, is impaired. These data indicate that AlgR2 is responsible for maintaining proper operation of the TCA cycle and energy metabolism. Images PMID:7928963

  19. Application of talcum powder, trichloroacetic acid and silver nitrate in female rats for non-surgical sterilization: evaluation of the apoptotic pathway mRNA and miRNA genes

    PubMed Central

    Yumrutas, Onder; Kara, Murat; Atilgan, Remzi; Kavak, Salih Burcin; Bozgeyik, Ibrahim; Sapmaz, Ekrem

    2015-01-01

    There are several methods used for non-surgical sterilization in birth control including quinacrine, trichloroacetic acid (TCA), erythromycin, tetracycline, silver nitrate and talcum powder. Among these, talcum powder, TCA and silver nitrate are the most commonly used. However, the toxic and carcinogenic activities of these chemicals in ovarian tissue have been poorly elucidated. This study demonstrates the expression levels of antioxidant, apoptotic and anti-apoptotic genes after administration of talc powder, TCA and silver nitrate for non-surgical sterilization in female rat models. The expression changes of some microRNAs (miR-15b, miR-21, miR-34a and miR-98) that play key roles in the apoptosis pathway were also included. All expression analyses were evaluated with real-time PCR. The expression levels of all genes appeared to be upregulated in the talcum powder group, but the results were not statistically significant. Increased expression of Gsr and Sod1 genes was statistically significant in the talcum powder group. In TCA and silver nitrate group, expression of all genes was appeared to be elevated but only the Gsr expression was statistically significant in the TCA-administrated group; there were no statistically significant changes in the silver nitrate group. miRNA expression levels were increased in talcum powder and TCA-administrated groups, but these results were not significant. Expression levels of miR-15b, miR-21 and miR-98 in the silver nitrate group were significantly increased. Consequently, these chemicals appear to be non-carcinogenic agents for rat ovarian tissue which do not induce apoptosis. However, talcum powder and TCA can be considered as agents that are toxic to ovarian tissue. PMID:25885949

  20. Application of talcum powder, trichloroacetic acid and silver nitrate in female rats for non-surgical sterilization: evaluation of the apoptotic pathway mRNA and miRNA genes.

    PubMed

    Yumrutas, Onder; Kara, Murat; Atilgan, Remzi; Kavak, Salih Burcin; Bozgeyik, Ibrahim; Sapmaz, Ekrem

    2015-04-01

    There are several methods used for non-surgical sterilization in birth control including quinacrine, trichloroacetic acid (TCA), erythromycin, tetracycline, silver nitrate and talcum powder. Among these, talcum powder, TCA and silver nitrate are the most commonly used. However, the toxic and carcinogenic activities of these chemicals in ovarian tissue have been poorly elucidated. This study demonstrates the expression levels of antioxidant, apoptotic and anti-apoptotic genes after administration of talc powder, TCA and silver nitrate for non-surgical sterilization in female rat models. The expression changes of some microRNAs (miR-15b, miR-21, miR-34a and miR-98) that play key roles in the apoptosis pathway were also included. All expression analyses were evaluated with real-time PCR. The expression levels of all genes appeared to be upregulated in the talcum powder group, but the results were not statistically significant. Increased expression of Gsr and Sod1 genes was statistically significant in the talcum powder group. In TCA and silver nitrate group, expression of all genes was appeared to be elevated but only the Gsr expression was statistically significant in the TCA-administrated group; there were no statistically significant changes in the silver nitrate group. miRNA expression levels were increased in talcum powder and TCA-administrated groups, but these results were not significant. Expression levels of miR-15b, miR-21 and miR-98 in the silver nitrate group were significantly increased. Consequently, these chemicals appear to be non-carcinogenic agents for rat ovarian tissue which do not induce apoptosis. However, talcum powder and TCA can be considered as agents that are toxic to ovarian tissue.

  1. Method of repressing the precipitation of calcium fluozirconate

    DOEpatents

    Newby, B.J.; Rhodes, D.W.

    1973-12-25

    Boric acid or a borate salt is added to aqueous solutions of fluoride containing radioactive wastes generated during the reprocessing of zirconium alloy nuclear fuels which are to be converted to solid form by calcining in a fluidized bed. The addition of calcium nitrate to the aqueous waste solutions to prevent fluoride volatility during calcination, causes the precipitation of calcium fluozirconate, which tends to form a gel at fluoride concentrations of 3.0 M or greater. The boron containing species introduced into the solution by the addition of the boric acid or borate salt retard the formation of the calcium fluozirconate precipitate and prevent formation of the gel. These boron containing species can be introduced into the solution by the addition of a borate salt but preferably are introduced by the addition of an aqueous solution of boric acid. (Official Gazette)

  2. Dissolved Organic Carbon In Precipitation At A Coastal Rural Site

    NASA Astrophysics Data System (ADS)

    Liptzin, D.; Daley, M.; Sive, B. C.; Talbot, R. W.; McDowell, W. H.

    2013-12-01

    Dissolved organic carbon (DOC) is a ubiquitous component of precipitation. This DOC is a complex mixture of compounds from biogenic and anthropogenic sources. The amount and chemistry of the DOC in precipitation has been studied for a variety of reasons: as a source of acidity, as a source of C to marine and terrestrial ecosystems, or to track the fate of individual compounds or pollutants. In most cases, past studies have focused on particular compounds or a limited number of precipitation events. Very little is known about the temporal trends in DOC or the relationship between DOC and other constituents of precipitation. We collected precipitation events for more than five years at a rural coastal site in New Hampshire. We evaluated the seasonal patterns and compared the DOC concentrations to other typical measures of the wet atmospheric deposition (ammonium, nitrate, sulfate, and chloride). In addition, we compared the DOC in precipitation to the concentrations of various organic constituents of the atmosphere. The volume weighted mean C concentration was 0.75 mg C/L with concentrations in the summer significantly higher than in the other three seasons. The DOC concentration was most strongly associated with ammonium concentrations (r=0.81), but was also significantly related to nitrate (r=0.50) and sulfate (r=0.63) concentrations. There was no significant association between DOC and chloride concentrations. Preliminary regression tree analysis suggests that the DOC concentration in precipitation was best predicted by the atmospheric concentration of methyl vinyl ketone, an oxidation product of isoprene. These results suggest that both terrestrial biogenic and anthropogenic sources may be important precursors to the C removed from the atmosphere during precipitation events.

  3. Statistical study of precipitating electrons

    NASA Technical Reports Server (NTRS)

    Fontheim, E. G.; Stasiewicz, K.; Chandler, M. O.; Ong, R. S. B.; Hoffman, R. A.

    1981-01-01

    Energy spectra of precipitating electrons are fitted to the sum of three distributions: a power law, a Maxwellian and a Gaussian. This fitting procedure determines seven parameters which characterize the essential features of each spectrum. These characteristic parameters are used to carry out various studies involving precipitating electrons. It is shown that the absence of the power-law population from a particular spectrum is related to the softness of the precipitating primary flux, that the Maxwellian temperature and the Gaussian peak energy have a positive correlation the strength of which varies with local time, that the upward moving Gaussian population has a loss cone distribution, and that the one dimensional velocity distribution parallel to the magnetic field occasionally displays a plateau or a hump on the tail.

  4. Portable liquid collection electrostatic precipitator

    DOEpatents

    Carlson, Duane C.; DeGange, John J.; Halverson, Justin E.

    2005-10-18

    A portable liquid collection electrostatic collection precipitator for analyzing air is provided which is a relatively small, self-contained device. The device has a tubular collection electrode, a reservoir for a liquid, and a pump. The pump pumps the liquid into the collection electrode such that the liquid flows down the exterior of the collection electrode and is recirculated to the reservoir. An air intake is provided such that air to be analyzed flows through an ionization section to ionize analytes in the air, and then flows near the collection electrode where ionized analytes are collected. A portable power source is connected to the air intake and the collection electrode. Ionizable constituents in the air are ionized, attracted to the collection electrode, and precipitated in the liquid. The precipitator may also have an analyzer for the liquid and may have a transceiver allowing remote operation and data collection.

  5. Periodic Precipitation Patterns during Coalescence of Reacting Sessile Droplets.

    PubMed

    Jehannin, Marie; Charton, Sophie; Karpitschka, Stefan; Zemb, Thomas; Möhwald, Helmuth; Riegler, Hans

    2015-10-27

    The coalescence behavior of two sessile drops that contain different chemical reactants (cerium nitrate and oxalic acid) and its impact on the formation of the solid precipitate (cerium oxalate) are investigated. With different liquids, the surface tension difference in the moment of drop-drop contact can induce a Marangoni flow. This flow can strongly influence the drop-drop coalescence behavior and thus, with reacting liquids, also the reaction and its products (through the liquid mixing). In our study we find three distinctly different coalescence behaviors ("barrier", "intermediate", "noncoalescence"), in contrast to only two behaviors that were observed in the case of nonreacting liquids. The amount of liquid mixing and thus the precipitation rate are very different for the three cases. The "intermediate" case, which exhibits the strongest mixing, has been studied in more detail. For high oxalic acid concentrations, mainly needle-like aggregates, and for low concentrations, mainly flower-like precipitate morphologies are obtained. In a transition range of the oxalic acid concentration, both morphologies can be produced. With the applied coalescence conditions, the different aggregate particles are arranged and fixed in a precipitate raft in a regular, periodic line pattern. This confirms the drop-drop coalescence configuration as a convection-reaction-diffusion system, which can have stationary as well as oscillatory behavior depending on the system parameters.

  6. Timber Mountain Precipitation Monitoring Station

    SciTech Connect

    Lyles, Brad; McCurdy, Greg; Chapman, Jenny; Miller, Julianne

    2012-01-01

    A precipitation monitoring station was placed on the west flank of Timber Mountain during the year 2010. It is located in an isolated highland area near the western border of the Nevada National Security Site (NNSS), south of Pahute Mesa. The cost of the equipment, permitting, and installation was provided by the Environmental Monitoring Systems Initiative (EMSI) project. Data collection, analysis, and maintenance of the station during fiscal year 2011 was funded by the U.S. Department of Energy, National Nuclear Security Administration, Nevada Site Office Environmental Restoration, Soils Activity. The station is located near the western headwaters of Forty Mile Wash on the Nevada Test and Training Range (NTTR). Overland flows from precipitation events that occur in the Timber Mountain high elevation area cross several of the contaminated Soils project CAU (Corrective Action Unit) sites located in the Forty Mile Wash watershed. Rain-on-snow events in the early winter and spring around Timber Mountain have contributed to several significant flow events in Forty Mile Wash. The data from the new precipitation gauge at Timber Mountain will provide important information for determining runoff response to precipitation events in this area of the NNSS. Timber Mountain is also a groundwater recharge area, and estimation of recharge from precipitation was important for the EMSI project in determining groundwater flowpaths and designing effective groundwater monitoring for Yucca Mountain. Recharge estimation additionally provides benefit to the Underground Test Area Sub-project analysis of groundwater flow direction and velocity from nuclear test areas on Pahute Mesa. Additionally, this site provides data that has been used during wild fire events and provided a singular monitoring location of the extreme precipitation events during December 2010 (see data section for more details). This letter report provides a summary of the site location, equipment, and data collected in

  7. Measurement and modeling of asphaltene precipitation

    SciTech Connect

    Burke, N.E.; Hobbs, R.E.; Kashou, S.F. )

    1990-11-01

    This paper reports on experimental asphaltene precipitation data on several live-oil/solvent mixtures at reservoir conditions measured to study the effects of temperature, pressure, and composition on precipitate formation and the relationships between critical properties, PVT phase behavior, and precipitate formation. Data generated by the model can be used to identify operating conditions conducive to precipitate formation.

  8. Electron precipitation pattern and substorm morphology

    NASA Technical Reports Server (NTRS)

    Hoffman, R. A.; Burch, J. L.

    1972-01-01

    Patterns of the precipitation of low energy electrons observed by polar satellites were examined as functions of substorm phase. Precipitation boundaries are generally identifiable at the low latitude edge of polar cusp electron precipitation and at the poleward edge of precipitation in the premidnight sector. Both of these boundaries move equatorward when the interplanetary magnetic field turns southward.

  9. Simultaneous quantification of chlorogenic acid and taurocholic acid in human plasma by LC-MS/MS and its application to a pharmacokinetic study after oral administration of Shuanghua Baihe tablets.

    PubMed

    Gu, Pan; Liu, Rui-Juan; Cheng, Min-Lu; Wu, Yao; Zheng, Lu; Liu, Yu-Jie; Ma, Peng-Cheng; Ding, Li

    2016-04-01

    An LC-MS/MS method was developed and validated for the simultaneous quantification of chlorogenic acid (CGA) and taurocholic acid (TCA) in human plasma using hydrochlorothiazide as the internal standard. The chromatographic separation was achieved on a Hedera ODS-2 column with a gradient elution using 10 mmol·L(-1) of ammonium acetate buffer solution containing 0.5% of formic acid - acetonitrile as mobile phase at a flow rate of 300 μL·min(-1). The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring in negative ESI mode. The method was fully validated over the concentration ranges of 0.1-10 ng·mL(-1) for CGA and 2-150 ng·mL(-1) for TCA. It was successfully applied to a pharmacokinetic study of CGA and TCA in healthy Chinese volunteers after oral administration of Shuanghua Baihe tablets (SBTs). In the single-dose study, the maximum plasma concentration (Cmax), time to reach Cmax (Tmax) and elimination half-life (t1/2) of CGA were (0.763 8 ± 0.542 0) ng·mL(-1), (1.0 ± 0.5) h, and (1.3 ± 0.6) h, respectively. In the multiple-dose study, the Cmax, Tmax and t1/2 of CGA were (0.663 7 ± 0.583 3) ng·mL(-1), (1.1 ± 0.5) h, and (1.4 ± 0.7) h, respectively. For TCA, no significant characteristic increasing plasma TCA concentration-time curve was found in the volunteers after oral administration of SBTs, indicating its complicated process in vivo as an endogenous ingredient.

  10. Acid Rain: What It Is -- How You Can Help!

    ERIC Educational Resources Information Center

    National Wildlife Federation, Washington, DC.

    This publication discusses the nature and consequences of acid precipitation (commonly called acid rain). Topic areas include: (1) the chemical nature of acid rain; (2) sources of acid rain; (3) geographic areas where acid rain is a problem; (4) effects of acid rain on lakes; (5) effect of acid rain on vegetation; (6) possible effects of acid rain…

  11. Nonlinear Dynamics of Banded Iron Formation Precipitation

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Xu, H.; Merino, E.

    2010-12-01

    Banded iron formations (BIFs) carry important information on the early evolution of the Earth. The actual mechanisms for their formation remain controversial. We have shown that the passage from predominant occurrence of BIFs in the Archaean-Early Proterozoic to their absence thereafter may have reflected compositional changes in the oceanic crust. Fe-Si-rich geologic fluids can be generated only from Al-poor oceanic crust through hydrothermal leaching by seawater. Al enrichment in the oceanic crust after ~ 1.7 Ga ago tends to prevent BIF formation. We have further shown that periodic precipitation of iron and silica minerals in alternating bands can be induced by positive feedbacks among relevant chemical reactions as a Fe-Si-rich hydrothermal fluid mixes with ambient seawater. Complexation of dissolved Fe(II) with silicic acid plays a crucial role in the self-organized process. Small-scale (< 1 cm) BIF bandings are thus attributed to the internal dynamics of the chemical system, rather than to an outside force such as surface temperature variations. In this presentation, we provide a detailed stability analysis of the model we developed to clarify the physical and chemical conditions for oscillatory precipitation of BIFs.

  12. Experimental study of brushite precipitation

    NASA Astrophysics Data System (ADS)

    Arifuzzaman, S. M.; Rohani, S.

    2004-07-01

    A systematic approach was developed for the synthesis of orthophosphates in the laboratory. A set of experiments was designed to investigate the influence of initial calcium and phosphorus concentration on the precipitated phase, nucleation pH and product size distribution at 25°C. Another goal was to characterize the precipitated phase. The investigation was conducted in a batch reactor. The initial molar concentration of calcium chloride and hydrated sodium phosphate solutions was varied from 0.005 to 0.08-mole dm -3 and the solution pH was kept under 7.1. Analysis by powder XRD, FTIR and elemental P/Ca revealed that the crystals precipitated were pure brushite (dicalcium phosphate dihydrate), as expected, except in one experiment in which amorphous calcium phosphate precipitated. The brushite crystals produced had plate-like morphology as investigated by scanning electron microscopy (SEM). The nucleation pH showed a decreasing trend as the concentration of the calcium and phosphorus increased in the reactor, but the volume mean diameter of the crystals and the span of the crystal size distribution did not show any sensitivity to the changes in the initial calcium and phosphorus concentration.

  13. Classroom Exercises Utilizing Precipitation Data.

    ERIC Educational Resources Information Center

    Kohler, Fred

    Precipitation data for Macomb (Illinois) for the period 1912-1981 were the bases for developing classroom exercises that offered college students experience in collecting such data. After students collected the data, they reduced them to manageable proportions, and then examined average long-term relations which may have emerged among yearly,…

  14. Grassland responses to precipitation extremes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grassland ecosystems are naturally subjected to periods of prolonged drought and sequences of wet years. Climate change is expected to enhance the magnitude and frequency of extreme events at the intraannual and multiyear scales. Are grassland responses to extreme precipitation simply a response to ...

  15. Waste and Simulant Precipitation Issues

    SciTech Connect

    Steele, W.V.

    2000-11-29

    As Savannah River Site (SRS) personnel have studied methods of preparing high-level waste for vitrification in the Defense Waste Processing Facility (DWPF), questions have arisen with regard to the formation of insoluble waste precipitates at inopportune times. One option for decontamination of the SRS waste streams employs the use of an engineered form of crystalline silicotitanate (CST). Testing of the process during FY 1999 identified problems associated with the formation of precipitates during cesium sorption tests using CST. These precipitates may, under some circumstances, obstruct the pores of the CST particles and, hence, interfere with the sorption process. In addition, earlier results from the DWPF recycle stream compatibility testing have shown that leaching occurs from the CST when it is stored at 80 C in a high-pH environment. Evidence was established that some level of components of the CST, such as silica, was leached from the CST. This report describes the results of equilibrium modeling and precipitation studies associated with the overall stability of the waste streams, CST component leaching, and the presence of minor components in the waste streams.

  16. Electrostatic Precipitator (ESP) TRAINING MANUAL

    EPA Science Inventory

    The manual assists engineers in using a computer program, the ESPVI 4.0W, that models all elements of an electrostatic precipitator (ESP). The program is a product of the Electric Power Research Institute and runs in the Windows environment. Once an ESP is accurately modeled, the...

  17. Ninety day toxicity study of chloroacetic acids in rats.

    PubMed

    Bhat, H K; Kanz, M F; Campbell, G A; Ansari, G A

    1991-08-01

    Chloroacetic acids are produced in drinking water as a result of disinfection processes. Chloroacetic acids are also metabolites of widely used and toxic halogenated hydrocarbons. Thus, chronic human exposure to these chemicals is likely to occur. The objective of the present study was to examine the toxic effects of monochloroacetic acid (MCA), dichloroacetic acid (DCA), and trichloroacetic acid (TCA) in a 90-day subchronic study in rats via oral exposure by drinking water. Chloroacetic acid solutions were prepared at concentrations which provided an approximate intake of 1/4 the LD50 dose per day: MCA, 1.9 mM; DCA, 80.5 mM; TCA, 45.8 mM. Control rats received distilled water only. After 90 days, major organs were removed, fixed, paraffin embedded, and stained. Light microscopic examination of the major organs revealed variable degrees of alterations in the lung and liver of all three treated groups. In the liver, morphological changes were predominantly localized to the portal triads, which were mildly to moderately enlarged with random bile duct proliferation, extension of portal veins, fibrosis, edema, and occasional foci of inflammation. In the lungs, minimal alterations were observed as foci of perivascular inflammation on small pulmonary veins. Morphological changes in the testes and brain were seen only in the DCA treated group. Testes were atrophic with few spermatocytes and no mature spermatozoa. Focal vacuolation and gliosis were present in the forebrain and brainstem. The results of these studies indicate that, relative to their respective LD50 values, DCA given at 80.5 mM is more toxic than TCA given at 45.8 mM and MCA at 1.9 mM is least toxic.

  18. PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINATING ELEMENTS

    DOEpatents

    Sutton, J.B.

    1958-02-18

    This patent relates to an improved method for the decontamination of plutonium. The process consists broadly in an improvement in a method for recovering plutonium from radioactive uranium fission products in aqueous solutions by decontamination steps including byproduct carrier precipitation comprising the step of introducing a preformed aqueous slurry of a hydroxide of a metal of group IV B into any aqueous acidic solution which contains the plutonium in the hexavalent state, radioactive uranium fission products contaminant and a by-product carrier precipitate and separating the metal hydroxide and by-product precipitate from the solution. The process of this invention is especially useful in the separation of plutonium from radioactive zirconium and columbium fission products.

  19. Formation of chloroacetic acids from soil, humic acid and phenolic moieties.

    PubMed

    Fahimi, I J; Keppler, F; Schöler, H F

    2003-07-01

    The mechanism of formation of chloroacetates, which are important toxic environmental substances, has been controversial. Whereas the anthropogenic production has been well established, a natural formation has also been suggested. In this study the natural formation of chloroacetic acids from soil, as well as from humic material which is present in soil and from phenolic model substances has been investigated. It is shown that chloroacetates are formed from humic material with a linear relationship between the amount of humic acid used and chloroacetates found. More dichloroacetate (DCA) than trichloroacetate (TCA) is produced. The addition of Fe(2+), Fe(3+) and H(2)O(2) leads to an increased yield. NaCl was added as a source of chloride. We further examined the relationship between the structure and reactivity of phenolic substances, which can be considered as monomeric units of humic acids. Ethoxyphenol with built-in ethyl groups forms large amounts of DCA and TCA. The experiments with phenoxyacetic acid yielded large amounts of monochloroacetate (MCA). With other phenolic substances a ring cleavage was observed. Our investigations indicate that chloroacetates are formed abiotically from humic material and soils in addition to their known biotic mode of formation.

  20. METHOD OF RECOVERING PLUTONIUM VALUES FROM AQUEOUS SOLUTIONS BY CARRIER PRECIPITATION

    DOEpatents

    James, R.A.; Thompson, S.G.

    1959-11-01

    A process is presented for pretreating aqueous nitric acid- plutonium solutions containing a small quantity of hydrazine that has formed as a decomposition product during the dissolution of neutron-bombarded uranium in nitric acid and that impairs the precipitation of plutonium on bismuth phosphate. The solution is digested with alkali metal dichromate or potassium permanganate at between 75 and 100 deg C; sulfuric acid at approximately 75 deg C and sodium nitrate, oxaiic acid plus manganous nitrate, or hydroxylamine are added to the solution to secure the plutonium in the tetravalent state and make it suitable for precipitation on BiPO/sub 4/.

  1. APols-aided protein precipitation: a rapid method for concentrating proteins for proteomic analysis.

    PubMed

    Ning, Zhibin; Hawley, Brett; Seebun, Deeptee; Figeys, Daniel

    2014-10-01

    Amphipols (APols) are a newly designed and milder class of detergent. They have been used primarily in protein structure analysis for membrane protein trapping and stabilization. We have recently demonstrated that APols can be used as an alternative detergent for proteome extraction and digestion, to achieve a "One-stop" single-tube workflow for proteomics. In this workflow, APols are removed by precipitation after protein digestion without depleting the digested peptides. Here, we took further advantage of this precipitation characteristic of APols to concentrate proteins from diluted samples. In contrast with tryptic peptides, a decrease in pH leads to the unbiased co-precipitation of APols with proteins, including globular hydrophilic proteins. We demonstrated that this precipitation is a combined effect of acid precipitation and the APols' protein interactions. Also, we have been able to demonstrate that APols-aided protein precipitation works well on diluted samples, such as secretome sample, and provides a rapid method for protein concentration.

  2. Thioredoxin, a master regulator of the tricarboxylic acid cycle in plant mitochondria.

    PubMed

    Daloso, Danilo M; Müller, Karolin; Obata, Toshihiro; Florian, Alexandra; Tohge, Takayuki; Bottcher, Alexandra; Riondet, Christophe; Bariat, Laetitia; Carrari, Fernando; Nunes-Nesi, Adriano; Buchanan, Bob B; Reichheld, Jean-Philippe; Araújo, Wagner L; Fernie, Alisdair R

    2015-03-17

    Plant mitochondria have a fully operational tricarboxylic acid (TCA) cycle that plays a central role in generating ATP and providing carbon skeletons for a range of biosynthetic processes in both heterotrophic and photosynthetic tissues. The cycle enzyme-encoding genes have been well characterized in terms of transcriptional and effector-mediated regulation and have also been subjected to reverse genetic analysis. However, despite this wealth of attention, a central question remains unanswered: "What regulates flux through this pathway in vivo?" Previous proteomic experiments with Arabidopsis discussed below have revealed that a number of mitochondrial enzymes, including members of the TCA cycle and affiliated pathways, harbor thioredoxin (TRX)-binding sites and are potentially redox-regulated. We have followed up on this possibility and found TRX to be a redox-sensitive mediator of TCA cycle flux. In this investigation, we first characterized, at the enzyme and metabolite levels, mutants of the mitochondrial TRX pathway in Arabidopsis: the NADP-TRX reductase a and b double mutant (ntra ntrb) and the mitochondrially located thioredoxin o1 (trxo1) mutant. These studies were followed by a comparative evaluation of the redistribution of isotopes when (13)C-glucose, (13)C-malate, or (13)C-pyruvate was provided as a substrate to leaves of mutant or WT plants. In a complementary approach, we evaluated the in vitro activities of a range of TCA cycle and associated enzymes under varying redox states. The combined dataset suggests that TRX may deactivate both mitochondrial succinate dehydrogenase and fumarase and activate the cytosolic ATP-citrate lyase in vivo, acting as a direct regulator of carbon flow through the TCA cycle and providing a mechanism for the coordination of cellular function.

  3. Identification of a Chemoreceptor for Tricarboxylic Acid Cycle Intermediates

    PubMed Central

    Lacal, Jesús; Alfonso, Carlos; Liu, Xianxian; Parales, Rebecca E.; Morel, Bertrand; Conejero-Lara, Francisco; Rivas, Germán; Duque, Estrella; Ramos, Juan L.; Krell, Tino

    2010-01-01

    We report the identification of McpS as the specific chemoreceptor for 6 tricarboxylic acid (TCA) cycle intermediates and butyrate in Pseudomonas putida. The analysis of the bacterial mutant deficient in mcpS and complementation assays demonstrate that McpS is the only chemoreceptor of TCA cycle intermediates in the strain under study. TCA cycle intermediates are abundantly present in root exudates, and taxis toward these compounds is proposed to facilitate the access to carbon sources. McpS has an unusually large ligand-binding domain (LBD) that is un-annotated in InterPro and is predicted to contain 6 helices. The ligand profile of McpS was determined by isothermal titration calorimetry of purified recombinant LBD (McpS-LBD). McpS recognizes TCA cycle intermediates but does not bind very close structural homologues and derivatives like maleate, aspartate, or tricarballylate. This implies that functional similarity of ligands, such as being part of the same pathway, and not structural similarity is the primary element, which has driven the evolution of receptor specificity. The magnitude of chemotactic responses toward these 7 chemoattractants, as determined by qualitative and quantitative chemotaxis assays, differed largely. Ligands that cause a strong chemotactic response (malate, succinate, and fumarate) were found by differential scanning calorimetry to increase significantly the midpoint of protein unfolding (Tm) and unfolding enthalpy (ΔH) of McpS-LBD. Equilibrium sedimentation studies show that malate, the chemoattractant that causes the strongest chemotactic response, stabilizes the dimeric state of McpS-LBD. In this respect clear parallels exist to the Tar receptor and other eukaryotic receptors, which are discussed. PMID:20498372

  4. Relation of precipitation quality to storm type, and deposition of dissolved chemical constituents from precipitation in Massachusetts, 1983-85

    USGS Publications Warehouse

    Gay, F.B.; Melching, C.S.

    1995-01-01

    Precipitation samples were collected for 83 storms at a rural inland site in Princeton, Mass., and 73 storms at a rural coastal site in Truro, Mass., to examine the quality of precipitation from storms and relate quality to three storm types (oceanic cyclone, continental cyclone, and cold front). At the inland site, Princeton, ranked-means of precipitation depth, storm duration, specific conductance, and concentrations and loads of hydrogen, sulfate, aluminum, bromide, and copper ions were affected by storm type. At the coastal site, Truro, ranked means of precipitation depth, storm duration, and concentrations and loads of calcium, chloride, magnesium, potassium, and sodium ions were affected by storm type. Precipitation chemistry at the coastal site was 85 percent oceanic in orgin, whereas precipitation 72 kilometers inland was 60 percent hydrogen, nitrate, and sulfate ions, reflecting fossil-fuel combustion. Concentrations and loads for specific conductance and 9 chemical constituents on an annual and seasonal basis were determined from National Atmospheric Deposition Program data for spring 1983 through winter 1985 at Quabbin (rural, inland), Waltham (suburban, inland) and Truro (rural, coastal), Massachusetts. Concentrations of magnesium, potassium, sodium, and chloride concentrations were highest at the coast and much lower inland, with very little difference between Waltham and Quabbin. Loads of ammonium, nitrate, sulfate, and hydrogen are highest at Quabbin and are about equal at Waltham and Truro. About twice as much nitrate and hydrogen and about 35 percent more sulfate is deposited at Quabbin than at Waltham or Truro; this pattern indicates that the interior of Massachusetts receives more acidic precipitation than do the eastern or the coastal areas of Massachusetts.

  5. 21 CFR 184.1007 - Aconitic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aconitic acid. 184.1007 Section 184.1007 Food and... Substances Affirmed as GRAS § 184.1007 Aconitic acid. (a) Aconitic acid (1,2,3-propenetricarboxylic acid... Ranunculaceae. Transaconitic acid can be isolated during sugarcane processing, by precipitation as the...

  6. 21 CFR 184.1007 - Aconitic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Aconitic acid. 184.1007 Section 184.1007 Food and... Substances Affirmed as GRAS § 184.1007 Aconitic acid. (a) Aconitic acid (1,2,3-propenetricarboxylic acid... Ranunculaceae. Transaconitic acid can be isolated during sugarcane processing, by precipitation as the...

  7. 21 CFR 184.1007 - Aconitic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Aconitic acid. 184.1007 Section 184.1007 Food and....1007 Aconitic acid. (a) Aconitic acid (1,2,3-propenetricarboxylic acid (C6H6O6), CAS Reg. No. 000499-12... acid can be isolated during sugarcane processing, by precipitation as the calcium salt from cane...

  8. 21 CFR 184.1007 - Aconitic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Aconitic acid. 184.1007 Section 184.1007 Food and... Substances Affirmed as GRAS § 184.1007 Aconitic acid. (a) Aconitic acid (1,2,3-propenetricarboxylic acid... Ranunculaceae. Transaconitic acid can be isolated during sugarcane processing, by precipitation as the...

  9. 21 CFR 184.1007 - Aconitic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Aconitic acid. 184.1007 Section 184.1007 Food and... Substances Affirmed as GRAS § 184.1007 Aconitic acid. (a) Aconitic acid (1,2,3-propenetricarboxylic acid... Ranunculaceae. Transaconitic acid can be isolated during sugarcane processing, by precipitation as the...

  10. Precipitation patterns during channel flow

    NASA Astrophysics Data System (ADS)

    Jamtveit, B.; Hawkins, C.; Benning, L. G.; Meier, D.; Hammer, O.; Angheluta, L.

    2013-12-01

    Mineral precipitation during channelized fluid flow is widespread in a wide variety of geological systems. It is also a common and costly phenomenon in many industrial processes that involve fluid flow in pipelines. It is often referred to as scale formation and encountered in a large number of industries, including paper production, chemical manufacturing, cement operations, food processing, as well as non-renewable (i.e. oil and gas) and renewable (i.e. geothermal) energy production. We have studied the incipient stages of growth of amorphous silica on steel plates emplaced into the central areas of the ca. 1 meter in diameter sized pipelines used at the hydrothermal power plant at Hellisheidi, Iceland (with a capacity of ca 300 MW electricity and 100 MW hot water). Silica precipitation takes place over a period of ca. 2 months at approximately 120°C and a flow rate around 1 m/s. The growth produces asymmetric ca. 1mm high dendritic structures ';leaning' towards the incoming fluid flow. A novel phase-field model combined with the lattice Boltzmann method is introduced to study how the growth morphologies vary under different hydrodynamic conditions, including non-laminar systems with turbulent mixing. The model accurately predicts the observed morphologies and is directly relevant for understanding the more general problem of precipitation influenced by turbulent mixing during flow in channels with rough walls and even for porous flow. Reference: Hawkins, C., Angheluta, L., Hammer, Ø., and Jamtveit, B., Precipitation dendrites in channel flow. Europhysics Letters, 102, 54001

  11. In vitro inhibition of OATP-mediated uptake of phalloidin using bile acid derivatives

    SciTech Connect

    Herraez, Elisa; Macias, Rocio I.R.; Vazquez-Tato, Jose; Vicens, Marta; Monte, Maria J.; Marin, Jose J.G.

    2009-08-15

    Hepatocyte uptake of phalloidin is carried out mainly by OATP1B1. We have used this compound as a prototypic substrate and assayed the ability to inhibit OATP-mediated phalloidin transport of four bile acid derivatives (BALU-1, BALU-2, BALU-3 and BALU-4) that showed positive results in preliminary screening. Using Xenopus laevis oocytes for heterologous expression of transporters, BALUs were found to inhibit taurocholic acid (TCA) transport by OATP1B1 (but not OATP1B3) as well as by rat Oatp1a1, Oatp1a4 and Oatp1b2. The study of their ability to inhibit sodium-dependent bile acid transporters revealed that the four BALUs induced an inhibition of rat Asbt-mediated TCA transport, which was similar to TCA-induced self-inhibition. Regarding human NTCP and rat Ntcp, BALU-1 differs from the other three BALUS in its lack of effect on TCA transport by these proteins. Using HPLC-MS/MS and CHO cells stably expressing OATP1B1 the ability of BALU-1 to inhibit the uptake of phalloidin itself by this transporter was confirmed. Kinetic analysis using X. laevis oocytes revealed that BALU-1-induced inhibition of OATP1B1 was mainly due to a competitive mechanism (Ki = 8 {mu}M). In conclusion, BALU-1 may be useful as a pharmacological tool to inhibit the uptake of compounds mainly taken up by OATP1B1 presumably without impairing bile acid uptake by the major carrier accounting for this process, i.e., NTCP.

  12. Precipitation of a poorly soluble model drug during in vitro lipolysis: characterization and dissolution of the precipitate.

    PubMed

    Sassene, Philip J; Knopp, Matthias M; Hesselkilde, Janne Z; Koradia, Vishal; Larsen, Anne; Rades, Thomas; Müllertz, Anette

    2010-12-01

    Precipitation of cinnarizine during in vitro lipolysis of a self-microemulsifying drug delivery system (SMEDDS) was characterized to gain a better understanding of the mechanisms behind the precipitation. During in vitro lipolysis of the SMEDDS with or without cinnarizine, samples were taken at several timepoints and ultracentrifuged. Cinnarizine content in the pellet increased from 4% to 59% during lipolysis. The precipitation of cinnarizine during in vitro lipolysis correlated well with the degree of lipid digestion, determined by sodium hydroxide addition. The pellet from the endpoint of lipolysis was isolated and subjected to dissolution in biorelevant media. Dissolution rate of cinnarizine from pellets containing precipitated cinnarizine was initially 10-fold higher than dissolution from blank pellet spiked with crystalline cinnarizine, reaching more than 50% drug dissolved in the first minute. Pellets were further characterized by X-ray powder diffraction (XRPD) and polarized light microscopy (PLM). Both methods indicated the presence of liquid crystalline phases of calcium fatty acid soaps, but no presence of crystalline cinnarizine in the pellet. Overall, dissolution studies along with XRPD and PLM analysis indicate that cinnarizine precipitating during in vitro lipolysis of this SMEDDS is not crystalline, suggesting an either amorphous form or a molecular dispersion.

  13. Global Precipitation Mission Visualization Tool

    NASA Technical Reports Server (NTRS)

    Schwaller, Mathew

    2011-01-01

    The Global Precipitation Mission (GPM) software provides graphic visualization tools that enable easy comparison of ground- and space-based radar observations. It was initially designed to compare ground radar reflectivity from operational, ground-based, S- and C-band meteorological radars with comparable measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite's precipitation radar instrument. This design is also applicable to other groundbased and space-based radars, and allows both ground- and space-based radar data to be compared for validation purposes. The tool creates an operational system that routinely performs several steps. It ingests satellite radar data (precipitation radar data from TRMM) and groundbased meteorological radar data from a number of sources. Principally, the ground radar data comes from national networks of weather radars (see figure). The data ingested by the visualization tool must conform to the data formats used in GPM Validation Network Geometry-matched data product generation. The software also performs match-ups of the radar volume data for the ground- and space-based data, as well as statistical and graphical analysis (including two-dimensional graphical displays) on the match-up data. The visualization tool software is written in IDL, and can be operated either in the IDL development environment or as a stand-alone executable function.

  14. Effect of multiple mutations in tricarboxylic acid cycle and one-carbon metabolism pathways on Edwardsiella ictaluri pathogenesis.

    PubMed

    Dahal, N; Abdelhamed, H; Lu, J; Karsi, A; Lawrence, M L

    2014-02-21

    Edwardsiella ictaluri is a Gram-negative facultative intracellular pathogen causing enteric septicemia of catfish (ESC). We have shown recently that tricarboxylic acid cycle (TCA) and one-carbon (C1) metabolism are involved in E. ictaluri pathogenesis. However, the effect of multiple mutations in these pathways is unknown. Here, we report four novel E. ictaluri mutants carrying double gene mutations in TCA cycle (EiΔmdhΔsdhC, EiΔfrdAΔsdhC), C1 metabolism (EiΔglyAΔgcvP), and both TCA and C1 metabolism pathways (EiΔgcvPΔsdhC). In-frame gene deletions were constructed by allelic exchange and mutants' virulence and vaccine efficacy were evaluated using in vivo bioluminescence imaging (BLI) as well as end point mortality counts in catfish fingerlings. Results indicated that all the double gene mutants were attenuated compared to wild-type (wt) E. ictaluri. There was a 1.39-fold average reduction in bioluminescence, and hence bacterial numbers, from all the mutants except for EiΔfrdAΔsdhC at 144 h post-infection. Vaccination with mutants was very effective in protecting channel catfish against subsequent infection with virulent E. ictaluri 93-146 strain. In particular, immersion vaccination resulted in complete protection. Our results provide further evidence on the importance of TCA and C1 metabolism pathways in bacterial pathogenesis.

  15. Membrane-based wet electrostatic precipitation

    SciTech Connect

    David J. Bayless; Liming Shi; Gregory Kremer; Ben J. Stuart; James Reynolds; John Caine

    2005-06-01

    Emissions of fine particulate matter, PM2.5, in both primary and secondary form, are difficult to capture in typical dry electrostatic precipitators (ESPs). Wet (or waterbased) ESPs are well suited for collection of acid aerosols and fine particulates because of greater corona power and virtually no re-entrainment. However, field disruptions because of spraying (misting) of water, formation of dry spots (channeling), and collector surface corrosion limit the applicability of current wet ESPs in the control of secondary PM2.5. Researchers at Ohio University have patented novel membrane collection surfaces to address these problems. Water-based cleaning in membrane collectors made of corrosion-resistant fibers is facilitated by capillary action between the fibers, maintaining an even distribution of water. This paper presents collection efficiency results of lab-scale and pilot-scale testing at First Energy's Bruce Mansfield Plant for the membrane-based wet ESP. The data indicate that a membrane wet ESP was more effective at collecting fine particulates, acid aerosols, and oxidized mercury than the metal-plate wet ESP, even with {approximately}15% less collecting area. 15 refs., 7 figs., 6 tabs.

  16. Membrane-based wet electrostatic precipitation.

    PubMed

    Bayless, David J; Shi, Liming; Kremer, Gregory; Stuart, Ben J; Reynolds, James; Caine, John

    2005-06-01

    Emissions of fine particulate matter, PM2.5, in both primary and secondary form, are difficult to capture in typical dry electrostatic precipitators (ESPs). Wet (or water-based) ESPs are well suited for collection of acid aerosols and fine particulates because of greater corona power and virtually no re-entrainment. However, field disruptions because of spraying (misting) of water, formation of dry spots (channeling), and collector surface corrosion limit the applicability of current wet ESPs in the control of secondary PM2.5. Researchers at Ohio University have patented novel membrane collection surfaces to address these problems. Water-based cleaning in membrane collectors made of corrosion-resistant fibers is facilitated by capillary action between the fibers, maintaining an even distribution of water. This paper presents collection efficiency results of lab-scale and pilot-scale testing at FirstEnergy's Bruce Mansfield Plant for the membrane-based wet ESP. The data indicate that a membrane wet ESP was more effective at collecting fine particulates, acid aerosols, and oxidized mercury than the metal-plate wet ESP, even with approximately 15% less collecting area.

  17. MAP3S/RAINE precipitation chemistry network: quality control

    SciTech Connect

    Not Available

    1980-10-01

    The participants of the precipitation chemistry network of the Multi-State Atmospheric Power Production Pollution Study/Regional Acidity of Industrial Emissions (MAP3S/RAINE) have developed procedures for maintenance of high quality output from the network operation. The documented procedures-most of which were in place before the network began sampling in 1976-include those for site selection and verification, field equipment, laboratory and data handling, and external laboratory quality testing.

  18. Trends in precipitation and stream-water chemistry in the northeastern United States, water years 1984-96

    USGS Publications Warehouse

    Clow, D.W.; Mast, M. Alisa

    1999-01-01

    Trends in precipitation and stream-water chemistry during water years 1984-96 were examined at eight precipitation monitoring sites and five nearby streams operated by the U.S. Geological Survey in the northeastern United States. The statistical analyses indicate the following: 1)Stream-water sulfate (SO4) concentrations decreased at seven of eight precipitation monitoring sites and in each of five streams. 2)Calcium plus magnesium (Ca + Mg) concentrations decreased at seven of eight precipitation monitoring sites and in three of five streams. 3)Precipitation acidity decreased at five of eight precipitation monitoring sites, but alkalinity increased in only one stream. These results indicate that decreases in atmospheric deposition of SO4 have resulted in decreased precipitation acidity. The chemical response of stream water to changes in precipitation chemistry was complex. Decreases in stream-water SO4 concentrations generally matched decreases of precipitation SO4. In stream water, increases in alkalinity were uncommon because decreases in SO4 concentrations often were accompanied by decreases in Ca + Mg concentrations. The decreases in Ca + Mg concentrations might be related to depletion of base cations from soil caused by long-term exposure to acidic deposition. Increases in streamwater alkalinity might not occur until rates of acidic deposition are reduced to substantially less than the rate of cation resupply by weathering and atmospheric deposition. In areas where forests are aggrading, recovery of stream-water alkalinity will be delayed further because of the acidifying effect of biomass accumulation.

  19. Chemical characteristics of precipitation at metropolitan Newark in the US East Coast

    NASA Astrophysics Data System (ADS)

    Song, Fei; Gao, Yuan

    To investigate the chemical characteristics of precipitation in the polluted coastal atmosphere, a total of 46 event-based precipitation samples were collected using a wet-only automatic precipitation collector from September 2006 to October 2007 at metropolitan Newark, New Jersey in the US East Coast. Samples were analyzed by ion chromatography for the concentrations of major inorganic ions (Cl -, NO 3-, SO 42-, F -, NH 4+, Ca 2+, Mg 2+, Na +, K +) and organic acid species (CH 3COO -, HCOO -, CH 2(COO) 22-, C 2O 42-). Selected trace metals (Sb, Pb, Al, V, Fe, Cr, Co, Ni, Cu, Zn, Cd) in samples were determined by ICPMS. Mass concentration results show that SO 42- was the most dominant anion accounting for 51% of the total anions, controlling the acidity of the precipitation. NH 4+ accounted for 48.6% of the total cations, dominating the precipitation neutralization. CH 3COO - and HCOO - were the two dominant water-soluble organic acid species, accounting for 42% and 40% of the total organic acids analyzed, respectively. Al, Zn and Fe were the three major trace metals in precipitation, accounting for 34%, 27%, and 25% of the total mass of metals analyzed. The pH values in precipitation ranged from 4.4 to 4.9, indicating an acidic nature. Enrichment Factor (EF) Analysis showed that Na +, Cl -, Mg 2+ and K + in the precipitation were primarily of marine origin, while most of the Fe, Co and Al were from crust sources. Pb, V, Cr, Ni were moderately enriched with EFs ranging 43-410, while Zn, Sb, Cu, Cd and F - were highly enriched with EFs > 700, indicating significant anthropogenic influences. Factor analysis suggests 6 major sources contributing to the observed composition of precipitation at this location: (1) nitrogen-enriched soil, (2) secondary pollution processes, (3) marine sources, (4) incinerations, (5) oil combustions, and (6) malonate-vanadium enriched sources. To further explore the source-precipitation event relationships and seasonality, cluster analysis

  20. Scientists Puzzle Over Acid Rain

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1975

    1975-01-01

    Reports on a growing concern over increased acidity in atmospheric percipitation. Explores possible causes of the increased acidity, identifies chemical components of precipitation in various parts of the world, and presents environmental changes that might be attributed to the acidity. (GS)

  1. Global Precipitation Measurement (GPM) Mission: NASA Precipitation Processing System (PPS)

    NASA Technical Reports Server (NTRS)

    Stocker, Erich Franz

    2008-01-01

    NASA is contributing the precipitation measurement data system PPS to support the GPM mission. PPS will distribute all GPM data products including NASA s GMI data products freely and quickly. PPS is implementing no system mechanisms for restricting access to GPM data. PPS is implementing no system mechanisms for charging for GPM data products. PPS will provide a number of geographical and parameter subsetting features available to its users. The first implementation of PPS (called PPS--) will assume processing of TRMM data effective 1 June 2008. TRMM realtime data will be available via PPS- to all users requesting access

  2. Agitation in DWPF Precipitate Pump Pit Tanks

    SciTech Connect

    Marek, J.C.

    1986-01-20

    An experimental program to test the reference agitator design for DWPF Precipitate Pump Pit Tanks has been completed. It was not known whether the reference agitator design would produce uniform mixing of precipitate slurry. There was also a concern that the reference agitator would produce excessive foaming of precipitate. An alternative agitator design that produces good mixing with little or no foam buildup was identified in the tests and is recommended for use in DWPF Precipitate Pump Pit Tanks. 7 refs.

  3. Precipitation hardening in aluminum alloy 6022

    SciTech Connect

    Miao, W.F.; Laughlin, D.E.

    1999-03-05

    Although the precipitation process in Al-Mg-Si alloys has been extensively studied, the understanding of the hardening process is still incomplete, since any change in composition, processing and aging practices, etc., could affect the precipitation hardening behavior. In this paper, hardness measurements, differential scanning calorimetry and transmission electron microscopy have been utilized to study the precipitation hardening behavior in aluminum alloy 6022.

  4. Purification of aqueous plutonium chloride solutions via precipitation and washing.

    SciTech Connect

    Stroud, M. A.; Salazar, R. R.; Abney, Kent David; Bluhm, E. A.; Danis, J. A.

    2003-01-01

    Pyrochemical operations at Los Alamos Plutonium Facility (TA-55) use high temperature melt s of calcium chloride for the reduction of plutonium oxide to plutonium metal and hi gh temperature combined melts of sodium chloride and potassium chloride mixtures for the electrorefining purification of plutonium metal . The remaining plutonium and americium are recovered from thes e salts by dissolution in concentrated hydrochloric acid followed by either solvent extraction or io n exchange for isolation and ultimately converted to oxide after precipitation with oxalic acid . Figur e 1 illustrates the current aqueous chloride flow sheet used for plutonium processing at TA-55 .

  5. Chemical and sulfur isotopic composition of precipitation in Beijing, China.

    PubMed

    Zhu, Guangxu; Guo, Qingjun; Chen, Tongbin; Lang, Yunchao; Peters, Marc; Tian, Liyan; Zhang, Hanzhi; Wang, Chunyu

    2016-03-01

    China is experiencing serious acid rain contamination, with Beijing among the worst-hit areas. To understand the chemical feature and the origin of inorganic ions in precipitation of Beijing, 128 precipitation samples were collected and analyzed for major water-soluble ions and δ(34)S. The pH values ranged from 3.68 to 7.81 and showed a volume weighted average value (VWA) of 5.02, with a frequency of acid rain of 26.8 %. The VWA value of electrical conductivity (EC) was 68.6 μS/cm, which was nearly 4 times higher than the background value of northern China. Ca(2+) represented the main cation; SO4 (2-) and NO3 (-) were the dominant anion in precipitation. Our study showed that SO4 (2-) and NO3 (-) originated from coal and fossil fuel combustion; Ca(2+), Mg(2+), and K(+) were from the continental sources. The δ(34)S value of SO4 (2-) in precipitation ranged from +2.1 to +12.8‰ with an average value of +4.7‰. The δ(34)S value showed a winter maximum and a summer minimum tendency, which was mainly associated with temperature-dependent isotope equilibrium fractionation as well as combustion of coal with relatively positive δ(34)S values in winter. Moreover, the δ(34)S values revealed that atmospheric sulfur in Beijing are mainly correlated to coal burning and traffic emission; coal combustion constituted a significant fraction of the SO4 (2-) in winter precipitation.

  6. Skill assessment of precipitation nowcasting in Mediterranean Heavy Precipitation Events

    NASA Astrophysics Data System (ADS)

    Bech, Joan; Berenguer, Marc

    2013-04-01

    Very short-term precipitation forecasting (i.e nowcasting) systems may provide valuable support in the weather surveillance process as they allow to issue automated early warnings for heavy precipitation events (HPE) as reviewed recently by Pierce et al. (2012). The need for warnings is essential in densely populated regions of small catchments, such as those typically found in Mediterranean coastal areas, prone to flash-floods. Several HPEs that occurred in NE Spain are analyzed using a nowcasting system based on the extrapolation of rainfall fields observed with weather radar following a Lagrangian approach developed and tested successfully in previous studies (Berenguer et al. 2005, 2011). Radar-based nowcasts, with lead times up to 3 h, are verified here against quality-controlled weather radar quantitative precipitation estimates and also against a dense network of raingauges. The basic questions studied are the dependence of forecast quality with lead time and rainfall amounts in several high-impact HPEs such as the 7 September 2005 Llobregat Delta river tornado outbreak (Bech et al. 2007) or the 2 November 2008 supercell tornadic thunderstorms (Bech et al. 2011) - both cases had intense rainfall rates (30' amounts exceeding 38.2 and 12.3 mm respectively) and daily values above 100 mm. Verification scores indicated that forecasts of 30' precipitation amounts provided useful guidance for lead times up to 60' for moderate intensities (up to 1 mm in 30') and up to 2.5h for lower rates (above 0.1 mm). On the other hand correlations of radar estimates and forecasts exceeded Eulerian persistence of precipitation estimates for lead times of 1.5 h for moderate intensities (up to 0.8 mm/h). We complete the analysis with a discussion on the reliability of threshold to lead time dependence based on the event-to-event variability found. This work has been done in the framework of the ProFEWS project (CGL2010-15892). References Bech J, N Pineda, T Rigo, M Aran, J Amaro, M

  7. Precipitation interpolation in mountainous areas

    NASA Astrophysics Data System (ADS)

    Kolberg, Sjur

    2015-04-01

    Different precipitation interpolation techniques as well as external drift covariates are tested and compared in a 26000 km2 mountainous area in Norway, using daily data from 60 stations. The main method of assessment is cross-validation. Annual precipitation in the area varies from below 500 mm to more than 2000 mm. The data were corrected for wind-driven undercatch according to operational standards. While temporal evaluation produce seemingly acceptable at-station correlation values (on average around 0.6), the average daily spatial correlation is less than 0.1. Penalising also bias, Nash-Sutcliffe R2 values are negative for spatial correspondence, and around 0.15 for temporal. Despite largely violated assumptions, plain Kriging produces better results than simple inverse distance weighting. More surprisingly, the presumably 'worst-case' benchmark of no interpolation at all, simply averaging all 60 stations for each day, actually outperformed the standard interpolation techniques. For logistic reasons, high altitudes are under-represented in the gauge network. The possible effect of this was investigated by a) fitting a precipitation lapse rate as an external drift, and b) applying a linear model of orographic enhancement (Smith and Barstad, 2004). These techniques improved the results only marginally. The gauge density in the region is one for each 433 km2; higher than the overall density of the Norwegian national network. Admittedly the cross-validation technique reduces the gauge density, still the results suggest that we are far from able to provide hydrological models with adequate data for the main driving force.

  8. Mercuric iodate precipitation from radioiodine-containing off-gas scrubber solution

    DOEpatents

    Partridge, Jerry A.; Bosuego, Gail P.

    1982-01-01

    Mercuric nitrate-nitric acid scrub solutions containing radioiodine may be reduced in volume without excessive loss of volatile iodine. The use of concentrated nitric acid during an evaporation process oxidizes the mercury-iodide complex to a less volatile mercuric iodate precipitate.

  9. Detection of volcanic influence on global precipitation

    NASA Astrophysics Data System (ADS)

    Gillett, N. P.; Weaver, A. J.; Zwiers, F. W.; Wehner, M. F.

    2004-06-01

    Observations of terrestrial precipitation from the latter half of the 20th century are compared with precipitation simulated by the Parallel Climate Model to determine which external forcings have had a detectable influence on precipitation. Consistent with a previous study using another model, we found that the global mean response to all forcings combined was significantly correlated with that observed. A detection and attribution analysis applied to the simulated and observed precipitation indicated that the volcanic signal is detectable both on its own and in a multiple regression with other forcings. These results are consistent with the hypothesis that shortwave forcings exert a larger influence on precipitation than longwave forcings.

  10. Evaluation of the influence of chloroacetic acids on the pharmacokinetics of trihalomethanes in the rat.

    PubMed

    St-Pierre, Annie; Krishnan, Kannan; Tardif, Robert

    2003-12-12

    Chloroacetic acids (monochloroacetic acid [MCA], dichloroacetic acid [DCA], and trichloroacetic acid [TCA]) and trihalomethanes (THMs: chloroform [CHCl(3)], bromodichloromethane [BDCM], dibromochloromethane [DBCM], and bromoform [TBM]) are common by-products of the chlorination of drinking water. The purpose of this study was to evaluate the influence of chloroacetic acids on the pharmacokinetics of trihalomethanes in the male Sprague-Dawley rat. In the first series of studies, groups of 5 animals were given, by intravenous injections, a single dose of 0.125 mmol/kg of one of the four THMs. Additional groups received a binary mixture containing 0.125 mmol/kg of a THM plus 0.125 mmol/kg of a chloroacetic acid. The venous blood concentrations of unchanged THMs were measured by headspace gas chromatography from 5 min to 6 h postadministration. The areas under the blood concentration versus time curves (AUCs) of CHCl(3), BDCM, and DBCM were increased by a factor of 3.5, 1.6, and 2, respectively, by coadministration of TCA. DCA coadministration resulted in an increase in the AUC of DBCM (x2.5) and TBM (x1.3), whereas MCA modified the Cmax (x1.5) and AUC (x1.8) of BDCM and the AUC of DBCM (x2.5). In the second series of experiments, animals received either a single dose of 0.03125 mmol/kg of one of the four THMs, a mixture containing 0.03125 mmol/kg of each of the four THMs (total dose = 0.125 mmol/kg), or a mixture containing 0.03125 mmol/kg of each of the four THMs plus 0.125 mmol/kg of either TCA or DCA. Results indicated that the AUCs of CHCl(3), BDCM, DBCM, and TBM were increased during coadministration compared to single administrations (+2.5-fold). Combined administration of the four THMs with TCA, and not DCA, resulted in an increase of the AUCs of THMs (CHCl(3): x11.7; BDCM, DBCM, and TBM: x3.9) and an increase in the Cmax of CHCl(3) (x1.9). Overall, these results indicate that, at the dose levels tested in this study, TCA alters the blood concentration profiles

  11. Aluminum in Precipitation, Streams, and Shallow Groundwater in the New Jersey Pine Barrens

    NASA Astrophysics Data System (ADS)

    Budd, W. W.; Johnson, A. H.; Huss, J. B.; Turner, R. S.

    1981-08-01

    Total (acid reactive) aluminum deposited in bulk precipitation in the McDonalds Branch (New Jersey) basin was 140 mg m-2 yr-1 for the period May 1978-May 1980. Stream and groundwater outputs for the same period were 149 and 110 mg m-2 yr-1, respectively. Aluminum inputs and outputs were highest during summer months because of elevated concentrations coupled with increased precipitation and streamflow. Median acid reactive Al concentrations in precipitation, stream water, and groundwater were 100, 350, and 230 μg 1-1, respectively. In streams, acid reactive Al concentration is correlated with dissolved organic matter concentration, suggesting that Al is transported as an organometallic complex. Shallow groundwater Al concentration is apparently controlled by gibbsite solubility in mineral soils and thus is pH dependent. The relatively high Al concentrations are attributable to acid conditions and mobile organic matter.

  12. Temperature-precipitation relationships for Canadian stations

    SciTech Connect

    Isaac, G.A. ); Stuart, R.A. )

    1992-08-01

    The dependence of daily precipitation upon average daily temperature has been examined for all seasons using climatological data from 56 stations across Canada. For east and west coast sites, and the north, more precipitation occurs with warm and cold temperatures during January and July, respectively. In the middle of the country, the temperature dependence tends to increase toward the Arctic, with strong dependencies in the Northwest Territories and weaker dependencies on the Prairies. Southern Ontario and Quebec show almost no dependence of precipitation upon temperature during July, but more precipitation falls during warm weather during the winter. For stations within and immediately downwind of the Rockies, for all seasons, more precipitation occurs when the temperature is colder. These temperature-precipitation relationships can provide information on precipitation formation processes, as well as assistance in weather and climate forecasting.

  13. Illinois Precipitation Research: A Focus on Cloud and Precipitation Modification.

    NASA Astrophysics Data System (ADS)

    Changnon, Stanley A.; Czys, Robert R.; Scott, Robert W.; Westcott, Nancy E.

    1991-05-01

    At the heart of the 40-year atmospheric research endeavors of the Illinois State Water Survey have been studies to understand precipitation processes in order to learn how precipitation is modified purposefully and accidentally, and to measure the physical and socio-economic consequences of cloud and precipitation modification. Major field and laboratory activities of past years or briefly treated as a basis for describing the key findings of the past ten years. Recent studies of inadvertent and purposeful cloud and rain modification and their effects are emphasized, including a 1989 field project conducted in Illinois and key findings from an on-going exploratory experiment addressing cloud and rain modification. Results are encouraging for the use of dynamic seeding on summer cumuliform clouds of the Midwest.Typical in-cloud results at 10°C reveal multiple updrafts that tend to be filled with large amounts of supercooled drizzle and raindrops. Natural ice production is vigorous, and initial concentrations are larger than expected from ice nuclei. However, natural ice production is not so vigorous as to preclude opportunities for seeding. Radar-based studies of such clouds reveal that their echo cores usually can be identified prior to desired seeding times, which is significant for the evaluation of their behavior. Cell characteristics show considerable variance under different types of meteorological conditions. Analysis of cell mergers reveals that under conditions of weak vertical shear, mid-level intercell flow at 4 km occurs as the reflectivity bridge between cells rapidly intensifies. The degree of intensification of single-echo cores after they merge is strongly related to the age and vigor of the cores before they join. Hence, cloud growth may be enhanced if seeding can encourage echo cores to merge at critical times. Forecasting research has developed a technique for objectively distinguishing between operational seeding and nonoperational days and for

  14. Paleo Mars energetic particle precipitation

    NASA Astrophysics Data System (ADS)

    Alho, Markku; McKenna-Lawlor, Susan; Kallio, Esa

    2015-12-01

    A young Mars may well have possessed a global dipolar magnetic field that provided protection for the planet's atmosphere from the space weather environment. Against this background, we study in the present paper the effect of various dipole magnetic fields on particle precipitation (range 10 keV-4.5 MeV) on the upper Martian atmosphere as the magnetosphere gradually declined to become an induced magnetosphere. We utilized a hybrid plasma model to provide, in a self-consistent fashion, simulations (that included ion-kinetic effects) of the interaction between the Martian obstacle (magnetized or otherwise) and the solar wind. Besides the intrinsic dipole, with field strengths of ~100 nT and below, we assume modern solar and atmospheric parameters to examine the effect of the single variable, that is the dipole strength. We thereby investigated the precipitation of solar energetic particles on the upper atmosphere of the planet in circumstances characterized by the evolution of a diminishing Martian dynamo that initially generated an ideal dipolar field. It is demonstrated that an assumed Martian dipole would have provided, in the energy range investigated, significant shielding against proton impingement and that the interaction between the solar wind and the assumed Martian magnetic dipole would have been responsible for generating the shielding effect identified.

  15. Precipitation, Elevation and Relief in the Tropics

    NASA Astrophysics Data System (ADS)

    Anders, A. M.; Nesbitt, S. W.; Gemperline, J.

    2011-12-01

    TRMM (Tropical Rainfall Measuring Mission) satellite precipitation radar data indicate that near-surface precipitation rates vary as a function of elevation in distinct ways in different mountain ranges across the tropics. Regional maximum precipitation rates are found at very low elevation in India's Western Ghats, Hawaii, and Eastern Australia. In New Guinea, the Northern Andes, and Taiwan, the locally maximum precipitation rates occur at moderate elevations (~1000 m). Regional maximum precipitation rates occur at very high elevation (>2000 m) in the African Rift Valley and Mexico's Sierra Madre Occidental. We present a simple model to explain the occurrence of these different relationships between precipitation and elevation as a function of large-scale atmospheric conditions, including those related to flow, moisture, and lower-tropospheric static stability. Additionally, we note that spatial variability in precipitation corresponds with spatial variability in ridge-valley relief in several tropical mountain ranges. We examine topography derived from SRTM (Shuttle Radar Topography Mission) data and precipitation patterns in swaths cutting perpendicular to the strike of these mountain ranges. Ridge-valley relief is defined as the standard deviation of topographic elevation parallel to the strike of the range. Ridge-valley relief varies systematically across several mountain ranges in concert with annual average precipitation. Where precipitation rates are high, ridge-valley relief is diminished and where precipitation rates are low, ridge-valley relief is maximized. The correspondence of precipitation and relief suggest a dynamic interaction between orographic precipitation and topographic development and confirms the predictions of an idealized numerical model of the co-evolution of precipitation and topography.

  16. Precipitation zones of west-central Nevada

    USGS Publications Warehouse

    Lopes, Thomas J.; Medina, Rose L.

    2007-01-01

    Whether Nevada can sustain its fast rate of growth depends in part on accurately quantifying the amount of water that is available, including precipitation. The Precipitation-Zone Method (PZM) is a way of estimating mean annual precipitation at any point. The PZM was developed using data from west-central Nevada and northeastern California, but preliminary analysis indicates it can be applied to the entire state. Patterns in the spatial distribution of precipitation were identified by mapping station locations and plotting 1971-2000 precipitation normals versus station elevation. Precipitation zones are large areas where precipitation is linearly related to elevation. Four precipitation zones with different linear relations were delineated; these zones cover much of west-central Nevada. Regression equations with adjusted R2 values of 0.89 to 0.95 were developed for each zone. All regression equations estimate similar precipitation rates at 4,000 feet, but the slopes of the regression equations become progressively shallower to the south. A geographic information system, 30-meter digital elevation model, and the regression equations were used to estimate the distribution and volumes of precipitation in each zone and in hydrographic areas of the Walker River Basin. Comparison between the PZM and Parameter-elevation Regressions on Independent Slopes Model (PRISM) indicate PRISM estimates are linearly related to elevation at low elevations in each zone, but PRISM estimates become non-linear at high elevations and are up to 2.5 times greater than the normals. However, PRISM under-estimates more than it over-estimates precipitation compared to the PZM. The PZM estimated the same or larger volumes of precipitation compared to PRISM in three of the zones, and the larger volumes mostly were from areas that receive greater than 15 inches/year of precipitation. Additional work is needed to accurately estimate mean annual precipitation throughout Nevada.

  17. Comparing the relationship between precipitation and river geochemistry

    NASA Astrophysics Data System (ADS)

    Epp, A.; Luymes, R.; Bennett, M.; DaSilva, J.; Marsh, S. J.; Gillies, S. L.; Peucker-Ehrenbrink, B.; Voss, B.

    2013-12-01

    The geochemistry of precipitation affects the geochemistry of river water. Ideally, studies of river biogeochemistry should therefore include collection and analyses of dry and wet deposition. The Global Rivers Observatory has studied the Fraser River near Vancouver since the summer of 2009 at roughly bi-weekly resolution. The interpretation of this temporal record of river biogeochemistry, particularly the various sources of solutes, could be improved with a better understanding of atmospheric contributions. In this study precipitation and river water will be analysed from the Fraser River basin for nutrients as well as major and select trace ion concentrations. The nutrients analyzed will include ammonium (NH4), nitrate and nitrate (NO3-NO2), phosphate (PO4) and silicate (SiO4). Major ions include sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), chloride (Cl), and sulfate (SO4). Trace elements may include molybdenum, strontium, barium, uranium, rubidium, manganese and iron. Samples will be collected using the bulk method which collects both wet and dry deposition . Correlating precipitation chemistry with data on wind direction may help elucidate sources of nutrients and major ions. For instance, westerly sources may transport pollution from the City of Vancouver and agricultural lands in the Fraser delta. Such pollutants may increase the acidity of precipitation and imprint the water chemistry with a unique chemical signature . The results of this study will be helpful in correcting Fraser River water data for contributions from atmospheric deposition.

  18. Precipitate hydrolysis experimental facility (PHEF): Run 64 report

    SciTech Connect

    Lambert, D.P.; Edwards, R.E.; Shah, H.B.; Young, S.R.

    1994-07-29

    The significant findings of Run 64 are: (a) Carbon dioxide was demonstrated to be an acceptable inertant for the actual hydrolysis process. However, based on the severe degradation of the tetraphenylborate (TPB) precipitate slurry stored in the Precipitate Hold Tank (PHT) at PHEF following Run 65, further evaluation of the suitability of carbon dioxide as an inertant for the long term storage of precipitate slurries is warranted. (b) Phenylboronic acid (PBA) reaction kinetics were excellent with no detectable PBA in Precipitate Hydrolysis Aqueous (PHA) product. (c) PHA product was low in biphenyl (6 mg/l), diphenylamine (13 mg/l), and total high boiling organics (22 mg/l). (d) Reproduced vacuum collapse problems encountered in DWPF (Defense Waste Processing Facility) water runs and demonstrated that the high vacuums experience during water runs could not be reproduced under normal operating conditions. (e) High benzene losses through stack and fugitive emissions were noted during Run 64. This may lead to poor decanter extraction performance long term and may be problem in DWPF, especially during long lay-ups or at low attainments. Approximately 69% of the benzene produced during Run 64 was released as benzene emissions.

  19. Microbially-Mediated Precipitation of Calcium Carbonate Nanoparticles.

    PubMed

    Kang, Ser Ku; Roh, Yul

    2016-02-01

    Th