Effects of Al(III and Nano-Al13 Species on Malate Dehydrogenase Activity

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Rong Fu Chen

2011-05-01

Full Text Available The effects of different aluminum species on malate dehydrogenase (MDH activity were investigated by monitoring amperometric i-t curves for the oxidation of NADH at low overpotential using a functionalized multi-wall nanotube (MWNT modified glass carbon electrode (GCE. The results showed that Al(III and Al13 can activate the enzymatic activity of MDH, and the activation reaches maximum levels as the Al(III and Al13 concentration increase. Our study also found that the effects of Al(III and Al13 on the activity of MDH depended on the pH value and aluminum speciation. Electrochemical and circular dichroism spectra methods were applied to study the effects of nano-sized aluminum compounds on biomolecules.

Effects of Al(III) and nano-Al13 species on malate dehydrogenase activity.

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Yang, Xiaodi; Cai, Ling; Peng, Yu; Li, Huihui; Chen, Rong Fu; Shen, Ren Fang

2011-01-01

The effects of different aluminum species on malate dehydrogenase (MDH) activity were investigated by monitoring amperometric i-t curves for the oxidation of NADH at low overpotential using a functionalized multi-wall nanotube (MWNT) modified glass carbon electrode (GCE). The results showed that Al(III) and Al(13) can activate the enzymatic activity of MDH, and the activation reaches maximum levels as the Al(III) and Al(13) concentration increase. Our study also found that the effects of Al(III) and Al(13) on the activity of MDH depended on the pH value and aluminum speciation. Electrochemical and circular dichroism spectra methods were applied to study the effects of nano-sized aluminum compounds on biomolecules.

Role of malate transporter in lipid accumulation of oleaginous fungus Mucor circinelloides.

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Zhao, Lina; Cánovas-Márquez, José T; Tang, Xin; Chen, Haiqin; Chen, Yong Q; Chen, Wei; Garre, Victoriano; Song, Yuanda; Ratledge, Colin

2016-02-01

Fatty acid biosynthesis in oleaginous fungi requires the supply of reducing power, NADPH, and the precursor of fatty acids, acetyl-CoA, which is generated in the cytosol being produced by ATP: citrate lyase which requires citrate to be, transported from the mitochondrion by the citrate/malate/pyruvate transporter. This transporter, which is within the mitochondrial membrane, transports cytosolic malate into the mitochondrion in exchange for mitochondrial citrate moving into the cytosol (Fig. 1). The role of malate transporter in lipid accumulation in oleaginous fungi is not fully understood, however. Therefore, the expression level of the mt gene, coding for a malate transporter, was manipulated in the oleaginous fungus Mucor circinelloides to analyze its effect on lipid accumulation. The results showed that mt overexpression increased the lipid content for about 70 % (from 13 to 22 % dry cell weight, CDW), whereas the lipid content in mt knockout mutant decreased about 27 % (from 13 to 9.5 % CDW) compared with the control strain. Furthermore, the extracellular malate concentration was decreased in the mt overexpressing strain and increased in the mt knockout strain compared with the wild-type strain. This work suggests that the malate transporter plays an important role in regulating lipid accumulation in oleaginous fungus M. circinelloides.

The varied functions of aluminium-activated malate transporters-much more than aluminium resistance.

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Palmer, Antony J; Baker, Alison; Muench, Stephen P

2016-06-15

The ALMT (aluminium-activated malate transporter) family comprises a functionally diverse but structurally similar group of ion channels. They are found ubiquitously in plant species, expressed throughout different tissues, and located in either the plasma membrane or tonoplast. The first family member identified was TaALMT1, discovered in wheat root tips, which was found to be involved in aluminium resistance by means of malate exudation into the soil. However, since this discovery other family members have been shown to have many other functions such as roles in stomatal opening, general anionic homoeostasis, and in economically valuable traits such as fruit flavour. Recent evidence has also shown that ALMT proteins can act as key molecular actors in GABA (γ-aminobutyric acid) signalling, the first evidence that GABA can act as a signal transducer in plants. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Low pH, Aluminum, and Phosphorus Coordinately Regulate Malate Exudation through GmALMT1 to Improve Soybean Adaptation to Acid Soils1[W][OA

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Liang, Cuiyue; Piñeros, Miguel A.; Tian, Jiang; Yao, Zhufang; Sun, Lili; Liu, Jiping; Shaff, Jon; Coluccio, Alison; Kochian, Leon V.; Liao, Hong

2013-01-01

Low pH, aluminum (Al) toxicity, and low phosphorus (P) often coexist and are heterogeneously distributed in acid soils. To date, the underlying mechanisms of crop adaptation to these multiple factors on acid soils remain poorly understood. In this study, we found that P addition to acid soils could stimulate Al tolerance, especially for the P-efficient genotype HN89. Subsequent hydroponic studies demonstrated that solution pH, Al, and P levels coordinately altered soybean (Glycine max) root growth and malate exudation. Interestingly, HN89 released more malate under conditions mimicking acid soils (low pH, +P, and +Al), suggesting that root malate exudation might be critical for soybean adaptation to both Al toxicity and P deficiency on acid soils. GmALMT1, a soybean malate transporter gene, was cloned from the Al-treated root tips of HN89. Like root malate exudation, GmALMT1 expression was also pH dependent, being suppressed by low pH but enhanced by Al plus P addition in roots of HN89. Quantitative real-time PCR, transient expression of a GmALMT1-yellow fluorescent protein chimera in Arabidopsis protoplasts, and electrophysiological analysis of Xenopus laevis oocytes expressing GmALMT1 demonstrated that GmALMT1 encodes a root cell plasma membrane transporter that mediates malate efflux in an extracellular pH-dependent and Al-independent manner. Overexpression of GmALMT1 in transgenic Arabidopsis, as well as overexpression and knockdown of GmALMT1 in transgenic soybean hairy roots, indicated that GmALMT1-mediated root malate efflux does underlie soybean Al tolerance. Taken together, our results suggest that malate exudation is an important component of soybean adaptation to acid soils and is coordinately regulated by three factors, pH, Al, and P, through the regulation of GmALMT1 expression and GmALMT1 function. PMID:23341359

Novel properties of the wheat aluminum tolerance organic acid transporter (TaALMT1) revealed by electrophysiological characterization in Xenopus Oocytes: functional and structural implications.

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Piñeros, Miguel A; Cançado, Geraldo M A; Kochian, Leon V

2008-08-01

Many plant species avoid the phytotoxic effects of aluminum (Al) by exuding dicarboxylic and tricarboxylic acids that chelate and immobilize Al(3+) at the root surface, thus preventing it from entering root cells. Several novel genes that encode membrane transporters from the ALMT and MATE families recently were cloned and implicated in mediating the organic acid transport underlying this Al tolerance response. Given our limited understanding of the functional properties of ALMTs, in this study a detailed characterization of the transport properties of TaALMT1 (formerly named ALMT1) from wheat (Triticum aestivum) expressed in Xenopus laevis oocytes was conducted. The electrophysiological findings are as follows. Although the activity of TaALMT1 is highly dependent on the presence of extracellular Al(3+) (K(m1/2) of approximately 5 microm Al(3+) activity), TaALMT1 is functionally active and can mediate ion transport in the absence of extracellular Al(3+). The lack of change in the reversal potential (E(rev)) upon exposure to Al(3+) suggests that the "enhancement" of TaALMT1 malate transport by Al is not due to alteration in the transporter's selectivity properties but is solely due to increases in its anion permeability. The consistent shift in the direction of the E(rev) as the intracellular malate activity increases indicates that TaALMT1 is selective for the transport of malate over other anions. The estimated permeability ratio between malate and chloride varied between 1 and 30. However, the complex behavior of the E(rev) as the extracellular Cl(-) activity was varied indicates that this estimate can only be used as a general guide to understanding the relative affinity of TaALMT1 for malate, representing only an approximation of those expected under physiologically relevant ionic conditions. TaALMT1 can also mediate a large anion influx (i.e. outward currents). TaALMT1 is permeable not only to malate but also to other physiologically relevant anions such as Cl

The BnALMT1 Protein That is an Aluminum-Activated Malate Transporter is Localized in the Plasma Membrane

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Ligaba, Ayalew; Katsuhara, Maki; Sakamoto, Wataru; Matsumoto, Hideaki

2007-01-01

We have previously reported that Al-induces citrate and malate efflux from P-sufficient and P-deficient plants of rape (Brassica napus L.) and that P-deficiency alone could not induce this response. Further investigation showed that the transcript of two genes designated BnALMT1 and BnALMT2 is accumulated in roots by Al-treatment. Transgenic tobacco cells (Nicotiana tabacum) and Xenopus laevis oocytes expressing the BnALMT1 and BnALMT2 proteins released more malate than control cells in the p...

Altered Expression of the Malate-Permeable Anion Channel OsALMT4 Reduces the Growth of Rice Under Low Radiance

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Jie Liu; Jie Liu; Muyun Xu; Gonzalo M. Estavillo; Emmanuel Delhaize; Rosemary G. White; Meixue Zhou; Peter R. Ryan

2018-01-01

We examined the function of OsALMT4 in rice (Oryza sativa L.) which is a member of the aluminum-activated malate transporter family. Previous studies showed that OsALMT4 localizes to the plasma membrane and that expression in transgenic rice lines results in a constitutive release of malate from the roots. Here, we show that OsALMT4 is expressed widely in roots, shoots, flowers, and grain but not guard cells. Expression was also affected by ionic and osmotic stress, light and to the hormones ...

Novel Properties of the Wheat Aluminum Tolerance Organic Acid Transporter (TaALMT1) Revealed by Electrophysiological Characterization in Xenopus Oocytes: Functional and Structural Implications1[OA

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Piñeros, Miguel A.; Cançado, Geraldo M.A.; Kochian, Leon V.

2008-01-01

Many plant species avoid the phytotoxic effects of aluminum (Al) by exuding dicarboxylic and tricarboxylic acids that chelate and immobilize Al3+ at the root surface, thus preventing it from entering root cells. Several novel genes that encode membrane transporters from the ALMT and MATE families recently were cloned and implicated in mediating the organic acid transport underlying this Al tolerance response. Given our limited understanding of the functional properties of ALMTs, in this study a detailed characterization of the transport properties of TaALMT1 (formerly named ALMT1) from wheat (Triticum aestivum) expressed in Xenopus laevis oocytes was conducted. The electrophysiological findings are as follows. Although the activity of TaALMT1 is highly dependent on the presence of extracellular Al3+ (Km1/2 of approximately 5 μm Al3+ activity), TaALMT1 is functionally active and can mediate ion transport in the absence of extracellular Al3+. The lack of change in the reversal potential (Erev) upon exposure to Al3+ suggests that the “enhancement” of TaALMT1 malate transport by Al is not due to alteration in the transporter's selectivity properties but is solely due to increases in its anion permeability. The consistent shift in the direction of the Erev as the intracellular malate activity increases indicates that TaALMT1 is selective for the transport of malate over other anions. The estimated permeability ratio between malate and chloride varied between 1 and 30. However, the complex behavior of the Erev as the extracellular Cl− activity was varied indicates that this estimate can only be used as a general guide to understanding the relative affinity of TaALMT1 for malate, representing only an approximation of those expected under physiologically relevant ionic conditions. TaALMT1 can also mediate a large anion influx (i.e. outward currents). TaALMT1 is permeable not only to malate but also to other physiologically relevant anions such as Cl−, NO3−, and

Altered Expression of a Malate-Permeable Anion Channel, OsALMT4, Disrupts Mineral Nutrition1[OPEN

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Delhaize, Emmanuel

2017-01-01

Aluminum-activated malate transporters (ALMTs) form a family of anion channels in plants, but little is known about most of its members. This study examined the function of OsALMT4 from rice (Oryza sativa). We show that OsALMT4 is expressed in roots and shoots and that the OsALMT4 protein localizes to the plasma membrane. Transgenic rice lines overexpressing (OX) OsALMT4 released malate from the roots constitutively and had 2-fold higher malate concentrations in the xylem sap than nulls, indicating greater concentrations of malate in the apoplast. OX lines developed brown necrotic spots on the leaves that did not appear on nulls. These symptoms were not associated with altered concentrations of any mineral element in the leaves, although the OX lines had higher concentrations of Mn and B in their grain compared with nulls. While total leaf Mn concentrations were not different between the OX and null lines, Mn concentrations in the apoplast were greater in the OX plants. The OX lines also displayed increased expression of Mn transporters and were more sensitive to Mn toxicity than null plants. We showed that the growth of wild-type rice was unaffected by 100 µm Mn in hydroponics but, when combined with 1 mm malate, this concentration inhibited growth. We conclude that increasing OsALMT4 expression affected malate efflux and compartmentation within the tissues, which increased Mn concentrations in the apoplast of leaves and induced the toxicity symptoms. This study reveals new links between malate transport and mineral nutrition. PMID:29101278

Malate and fumarate extend lifespan in Caenorhabditis elegans.

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Clare B Edwards

Full Text Available Malate, the tricarboxylic acid (TCA cycle metabolite, increased lifespan and thermotolerance in the nematode C. elegans. Malate can be synthesized from fumarate by the enzyme fumarase and further oxidized to oxaloacetate by malate dehydrogenase with the accompanying reduction of NAD. Addition of fumarate also extended lifespan, but succinate addition did not, although all three intermediates activated nuclear translocation of the cytoprotective DAF-16/FOXO transcription factor and protected from paraquat-induced oxidative stress. The glyoxylate shunt, an anabolic pathway linked to lifespan extension in C. elegans, reversibly converts isocitrate and acetyl-CoA to succinate, malate, and CoA. The increased longevity provided by malate addition did not occur in fumarase (fum-1, glyoxylate shunt (gei-7, succinate dehydrogenase flavoprotein (sdha-2, or soluble fumarate reductase F48E8.3 RNAi knockdown worms. Therefore, to increase lifespan, malate must be first converted to fumarate, then fumarate must be reduced to succinate by soluble fumarate reductase and the mitochondrial electron transport chain complex II. Reduction of fumarate to succinate is coupled with the oxidation of FADH2 to FAD. Lifespan extension induced by malate depended upon the longevity regulators DAF-16 and SIR-2.1. Malate supplementation did not extend the lifespan of long-lived eat-2 mutant worms, a model of dietary restriction. Malate and fumarate addition increased oxygen consumption, but decreased ATP levels and mitochondrial membrane potential suggesting a mild uncoupling of oxidative phosphorylation. Malate also increased NADPH, NAD, and the NAD/NADH ratio. Fumarate reduction, glyoxylate shunt activity, and mild mitochondrial uncoupling likely contribute to the lifespan extension induced by malate and fumarate by increasing the amount of oxidized NAD and FAD cofactors.

The ALMT Family of Organic Acid Transporters in Plants and Their Involvement in Detoxification and Nutrient Security.

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Sharma, Tripti; Dreyer, Ingo; Kochian, Leon; Piñeros, Miguel A

2016-01-01

About a decade ago, members of a new protein family of anion channels were discovered on the basis of their ability to confer on plants the tolerance toward toxic aluminum ions in the soil. The efflux of Al 3+ -chelating malate anions through these channels is stimulated by external Al 3+ ions. This feature of a few proteins determined the name of the entire protein family as Aluminum-activated Malate Transporters (ALMT). Meanwhile, after several years of research, it is known that the physiological roles of ALMTs go far beyond Al-detoxification. In this review article we summarize the current knowledge on this transporter family and assess their involvement in diverse physiological processes.

The ALMT family of organic acid transporters in plants and their involvement in detoxification and nutrient security

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Tripti Sharma

2016-10-01

Full Text Available About a decade ago, members of a new protein family of anion channels were discovered on the basis of their ability to confer on plants the tolerance towards toxic aluminum ions in the soil. The efflux of Al3+-chelating malate anions through these channels is stimulated by external Al3+ ions. This feature of a few proteins determined the name of the entire protein family as Aluminum-activated Malate Transporters (ALMT. Meanwhile, after several years of research, it is known that the physiological roles of ALMTs go far beyond Al-detoxification. In this review article we summarize the current knowledge on this transporter family and assess their involvement in diverse physiological processes.

Correlation between myocardial malate/aspartate shuttle activity and EAAT1 protein expression in hyper- and hypothyroidism.

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Ralphe, J Carter; Bedell, Kurt; Segar, Jeffrey L; Scholz, Thomas D

2005-05-01

In the heart, elevated thyroid hormone leads to upregulation of metabolic pathways associated with energy production and development of hypertrophy. The malate/aspartate shuttle, which transfers cytosolic-reducing equivalents into the cardiac mitochondria, is increased 33% in hyperthyroid rats. Within the shuttle, the aspartate-glutamate carrier is rate limiting. The excitatory amino acid transporter type 1 (EAAT1) functions as a glutamate carrier in the malate/aspartate shuttle. In this study, we hypothesize that EAAT1 is regulated by thyroid hormone. Adult rats were injected with triiodothyronine (T3) or saline over a period of 8-9 days or provided with propylthiouracil (PTU) in their drinking water for 2 mo. Steady-state mRNA levels of EAAT1 and aralar1 and citrin (both cardiac mitochondrial aspartate-glutamate transporters) were determined by Northern blot analysis and normalized to 18S rRNA. A spectrophotometric assay of maximal malate/aspartate shuttle activity was performed on isolated cardiac mitochondria from PTU-treated and control animals. Protein lysates from mitochondria were separated by SDS-PAGE and probed with a human anti-EAAT1 IgG. Compared with control, EAAT1 mRNA levels (arbitrary units) were increased nearly threefold in T3-treated (3.1 +/- 0.5 vs. 1.1 +/- 0.2; P Hyperthyroidism in rats is related to an increase in cardiac expression of EAAT1 mRNA and protein. The 49% increase in EAAT1 mitochondrial protein level shows that malate/aspartate shuttle activity increased in hyperthyroid rat cardiac mitochondria. Although hypothyroidism resulted in a decrease in EAAT1 mRNA, neither the EAAT1 protein level nor shuttle activity was affected. EAAT1 regulation by thyroid hormone may facilitate increased metabolic demands of the cardiomyocyte during hyperthyroidism and impact cardiac function in hyperthyroidism.

The varied functions of aluminium-activated malate transporters–much more than aluminium resistance

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Palmer, Antony J.; Baker, Alison; Muench, Stephen P.

2016-01-01

The ALMT (aluminium-activated malate transporter) family comprises a functionally diverse but structurally similar group of ion channels. They are found ubiquitously in plant species, expressed throughout different tissues, and located in either the plasma membrane or tonoplast. The first family member identified was TaALMT1, discovered in wheat root tips, which was found to be involved in aluminium resistance by means of malate exudation into the soil. However, since this discovery other family members have been shown to have many other functions such as roles in stomatal opening, general anionic homoeostasis, and in economically valuable traits such as fruit flavour. Recent evidence has also shown that ALMT proteins can act as key molecular actors in GABA (γ-aminobutyric acid) signalling, the first evidence that GABA can act as a signal transducer in plants. PMID:27284052

Maize ZmALMT2 is a root anion transporter that mediates constitutive root malate efflux.

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Ligaba, Ayalew; Maron, Lyza; Shaff, Jon; Kochian, Leon; Piñeros, Miguel

2012-07-01

Root efflux of organic acid anions underlies a major mechanism of plant aluminium (Al) tolerance on acid soils. This efflux is mediated by transporters of the Al-activated malate transporter (ALMT) or the multi-drug and toxin extrusion (MATE) families. ZmALMT2 was previously suggested to be involved in Al tolerance based on joint association-linkage mapping for maize Al tolerance. In the current study, we functionally characterized ZmALMT2 by heterologously expressing it in Xenopus laevis oocytes and transgenic Arabidopsis. In oocytes, ZmALMT2 mediated an Al-independent electrogenic transport product of organic and inorganic anion efflux. Ectopic overexpression of ZmALMT2 in an Al-hypersensitive Arabidopsis KO/KD line lacking the Al tolerance genes, AtALMT1 and AtMATE, resulted in Al-independent constitutive root malate efflux which partially restored the Al tolerance phenotype. The lack of correlation between ZmALMT2 expression and Al tolerance (e.g., expression not localized to the root tip, not up-regulated by Al, and higher in sensitive versus tolerance maize lines) also led us to question ZmALMT2's role in Al tolerance. The functional properties of the ZmALMT2 transporter presented here, along with the gene expression data, suggest that ZmALMT2 is not involved in maize Al tolerance but, rather, may play a role in mineral nutrient acquisition and transport. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.

Altered Expression of the Malate-Permeable Anion Channel OsALMT4 Reduces the Growth of Rice Under Low Radiance

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Jie Liu

2018-05-01

Full Text Available We examined the function of OsALMT4 in rice (Oryza sativa L. which is a member of the aluminum-activated malate transporter family. Previous studies showed that OsALMT4 localizes to the plasma membrane and that expression in transgenic rice lines results in a constitutive release of malate from the roots. Here, we show that OsALMT4 is expressed widely in roots, shoots, flowers, and grain but not guard cells. Expression was also affected by ionic and osmotic stress, light and to the hormones ABA, IAA, and salicylic acid. Malate efflux from the transgenic plants over-expressing OsALMT4 was inhibited by niflumate and salicylic acid. Growth of transgenic lines with either increased OsALMT4 expression or reduced expression was measured in different environments. Light intensity caused significant differences in growth between the transgenic lines and controls. When day-time light was reduced from 700 to 300 μmol m-2s-1 independent transgenic lines with either increased or decreased OsALMT4 expression accumulated less biomass compared to their null controls. This response was not associated with differences in photosynthetic capacity, stomatal conductance or sugar concentrations in tissues. We propose that by disrupting malate fluxes across the plasma membrane carbon partitioning and perhaps signaling are affected which compromises growth under low light. We conclude that OsALMT4 is expressed widely in rice and facilitates malate efflux from different cell types. Altering OsALMT4 expression compromises growth in low-light environments.

A natural mutation-led truncation in one of the two aluminum-activated malate transporter-like genes at the Ma locus is associated with low fruit acidity in apple.

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Bai, Yang; Dougherty, Laura; Li, Mingjun; Fazio, Gennaro; Cheng, Lailiang; Xu, Kenong

2012-08-01

Acidity levels greatly affect the taste and flavor of fruit, and consequently its market value. In mature apple fruit, malic acid is the predominant organic acid. Several studies have confirmed that the major quantitative trait locus Ma largely controls the variation of fruit acidity levels. The Ma locus has recently been defined in a region of 150 kb that contains 44 predicted genes on chromosome 16 in the Golden Delicious genome. In this study, we identified two aluminum-activated malate transporter-like genes, designated Ma1 and Ma2, as strong candidates of Ma by narrowing down the Ma locus to 65-82 kb containing 12-19 predicted genes depending on the haplotypes. The Ma haplotypes were determined by sequencing two bacterial artificial chromosome clones from G.41 (an apple rootstock of genotype Mama) that cover the two distinct haplotypes at the Ma locus. Gene expression profiling in 18 apple germplasm accessions suggested that Ma1 is the major determinant at the Ma locus controlling fruit acidity as Ma1 is expressed at a much higher level than Ma2 and the Ma1 expression is significantly correlated with fruit titratable acidity (R (2) = 0.4543, P = 0.0021). In the coding sequences of low acidity alleles of Ma1 and Ma2, sequence variations at the amino acid level between Golden Delicious and G.41 were not detected. But the alleles for high acidity vary considerably between the two genotypes. The low acidity allele of Ma1, Ma1-1455A, is mainly characterized by a mutation at base 1455 in the open reading frame. The mutation leads to a premature stop codon that truncates the carboxyl terminus of Ma1-1455A by 84 amino acids compared with Ma1-1455G. A survey of 29 apple germplasm accessions using marker CAPS(1455) that targets the SNP(1455) in Ma1 showed that the CAPS(1455A) allele was associated completely with high pH and highly with low titratable acidity, suggesting that the natural mutation-led truncation is most likely responsible for the abolished function of Ma

Malate-aspartate shuttle and exogenous NADH/cytochrome c electron transport pathway as two independent cytosolic reducing equivalent transfer systems.

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Abbrescia, Daniela Isabel; La Piana, Gianluigi; Lofrumento, Nicola Elio

2012-02-15

In mammalian cells aerobic oxidation of glucose requires reducing equivalents produced in glycolytic phase to be channelled into the phosphorylating respiratory chain for the reduction of molecular oxygen. Data never presented before show that the oxidation rate of exogenous NADH supported by the malate-aspartate shuttle system (reconstituted in vitro with isolated liver mitochondria) is comparable to the rate obtained on activation of the cytosolic NADH/cytochrome c electron transport pathway. The activities of these two reducing equivalent transport systems are independent of each other and additive. NADH oxidation induced by the malate-aspartate shuttle is inhibited by aminooxyacetate and by rotenone and/or antimycin A, two inhibitors of the respiratory chain, while the NADH/cytochrome c system remains insensitive to all of them. The two systems may simultaneously or mutually operate in the transfer of reducing equivalents from the cytosol to inside the mitochondria. In previous reports we suggested that the NADH/cytochrome c system is expected to be functioning in apoptotic cells characterized by the presence of cytochrome c in the cytosol. As additional new finding the activity of reconstituted shuttle system is linked to the amount of α-ketoglutarate generated inside the mitochondria by glutamate dehydrogenase rather than by aspartate aminotransferase. Copyright © 2011 Elsevier Inc. All rights reserved.

Impaired Malate and Fumarate Accumulation Due to the Mutation of the Tonoplast Dicarboxylate Transporter Has Little Effects on Stomatal Behavior.

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Medeiros, David B; Barros, Kallyne A; Barros, Jessica Aline S; Omena-Garcia, Rebeca P; Arrivault, Stéphanie; Sanglard, Lílian M V P; Detmann, Kelly C; Silva, Willian Batista; Daloso, Danilo M; DaMatta, Fábio M; Nunes-Nesi, Adriano; Fernie, Alisdair R; Araújo, Wagner L

2017-11-01

Malate is a central metabolite involved in a multiplicity of plant metabolic pathways, being associated with mitochondrial metabolism and playing significant roles in stomatal movements. Vacuolar malate transport has been characterized at the molecular level and is performed by at least one carrier protein and two channels in Arabidopsis ( Arabidopsis thaliana ) vacuoles. The absence of the Arabidopsis tonoplast Dicarboxylate Transporter (tDT) in the tdt knockout mutant was associated previously with an impaired accumulation of malate and fumarate in leaves. Here, we investigated the consequences of this lower accumulation on stomatal behavior and photosynthetic capacity as well as its putative metabolic impacts. Neither the stomatal conductance nor the kinetic responses to dark, light, or high CO 2 were highly affected in tdt plants. In addition, we did not observe any impact on stomatal aperture following incubation with abscisic acid, malate, or citrate. Furthermore, an effect on photosynthetic capacity was not observed in the mutant lines. However, leaf mitochondrial metabolism was affected in the tdt plants. Levels of the intermediates of the tricarboxylic acid cycle were altered, and increases in both light and dark respiration were observed. We conclude that manipulation of the tonoplastic organic acid transporter impacted mitochondrial metabolism, while the overall stomatal and photosynthetic capacity were unaffected. © 2017 American Society of Plant Biologists. All Rights Reserved.

The metabolism of malate by cultured rat brain astrocytes

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McKenna, M.C.; Tildon, J.T.; Couto, R.; Stevenson, J.H.; Caprio, F.J. (Department of Pediatrics, University of Maryland School of Medicine, Baltimore (USA))

1990-12-01

Since malate is known to play an important role in a variety of functions in the brain including energy metabolism, the transfer of reducing equivalents and possibly metabolic trafficking between different cell types; a series of biochemical determinations were initiated to evaluate the rate of 14CO2 production from L-(U-14C)malate in rat brain astrocytes. The 14CO2 production from labeled malate was almost totally suppressed by the metabolic inhibitors rotenone and antimycin A suggesting that most of malate metabolism was coupled to the electron transport system. A double reciprocal plot of the 14CO2 production from the metabolism of labeled malate revealed biphasic kinetics with two apparent Km and Vmax values suggesting the presence of more than one mechanism of malate metabolism in these cells. Subsequent experiments were carried out using 0.01 mM and 0.5 mM malate to determine whether the addition of effectors would differentially alter the metabolism of high and low concentrations of malate. Effectors studied included compounds which could be endogenous regulators of malate metabolism and metabolic inhibitors which would provide information regarding the mechanisms regulating malate metabolism. Both lactate and aspartate decreased 14CO2 production from malate equally. However, a number of effectors were identified which selectively altered the metabolism of 0.01 mM malate including aminooxyacetate, furosemide, N-acetylaspartate, oxaloacetate, pyruvate and glucose, but had little or no effect on the metabolism of 0.5 mM malate. In addition, alpha-ketoglutarate and succinate decreased 14CO2 production from 0.01 mM malate much more than from 0.5 mM malate. In contrast, a number of effectors altered the metabolism of 0.5 mM malate more than 0.01 mM. These included methionine sulfoximine, glutamate, malonate, alpha-cyano-4-hydroxycinnamate and ouabain.

The plant homolog to the human sodium/dicarboxylic cotransporter is the vacuolar malate carrier

OpenAIRE

Emmerlich, Vera; Linka, Nicole; Reinhold, Thomas; Hurth, Marco A.; Traub, Michaela; Martinoia, Enrico; Neuhaus, H. Ekkehard

2003-01-01

Malate plays a central role in plant metabolism. It is an intermediate in the Krebs and glyoxylate cycles, it is the store for CO2 in C4 and crassulacean acid metabolism plants, it protects plants from aluminum toxicity, it is essential for maintaining the osmotic pressure and charge balance, and it is therefore involved in regulation of stomatal aperture. To fulfil many of these roles, malate has to be accumulated within the large central vacuole. Many unsuccessful efforts have been made in ...

A Dicarboxylate Transporter, LjALMT4, Mainly Expressed in Nodules of Lotus japonicus.

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Takanashi, Kojiro; Sasaki, Takayuki; Kan, Tomohiro; Saida, Yuka; Sugiyama, Akifumi; Yamamoto, Yoko; Yazaki, Kazufumi

2016-07-01

Legume plants can establish symbiosis with soil bacteria called rhizobia to obtain nitrogen as a nutrient directly from atmospheric N2 via symbiotic nitrogen fixation. Legumes and rhizobia form nodules, symbiotic organs in which fixed-nitrogen and photosynthetic products are exchanged between rhizobia and plant cells. The photosynthetic products supplied to rhizobia are thought to be dicarboxylates but little is known about the movement of dicarboxylates in the nodules. In terms of dicarboxylate transporters, an aluminum-activated malate transporter (ALMT) family is a strong candidate responsible for the membrane transport of carboxylates in nodules. Among the seven ALMT genes in the Lotus japonicus genome, only one, LjALMT4, shows a high expression in the nodules. LjALMT4 showed transport activity in a Xenopus oocyte system, with LjALMT4 mediating the efflux of dicarboxylates including malate, succinate, and fumarate, but not tricarboxylates such as citrate. LjALMT4 also mediated the influx of several inorganic anions. Organ-specific gene expression analysis showed LjALMT4 mRNA mainly in the parenchyma cells of nodule vascular bundles. These results suggest that LjALMT4 may not be involved in the direct supply of dicarboxylates to rhizobia in infected cells but is responsible for supplying malate as well as several anions necessary for symbiotic nitrogen fixation, via nodule vasculatures.

Physiological and Biochemical Responses to Aluminum Stress in the Root of a Biodiesel Plant Jatropha curcas L.

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RADITE TISTAMA

2012-03-01

Full Text Available We investigated J. curcas responses to aluminum stress, histochemically and biochemically. Histochemical stainings were observed to analysis aluminum accumulation, lipid peroxidation and the loss of plasma membrane integrity on the surface and tissue of the root apex. Enzymatic analysis was conducted to measure malate content in leaf, root and malate efflux in the medium. We used M. malabathricum as a comparison for Al-tolerance plant. J. curcas root elongation was inhibited by 0.4 mM AlCl3, while M. malabathricum root elongation was inhibited by 0.8 mM AlCl3 treatment. Inhibition of root elongation has high correlation with Al accumulation in the root apex, which caused lipid degradation and cell death. Generally, malate content in J. curcas leaf and root was higher than that in M. malabathricum. In the contrary malate efflux from the root into the medium was lower. J. curcas root has a different pattern compared to M. malabathricum in malate synthesis and malate secretion when treated with a different Al concentration. We categorized J. curcas acc IP3 as more sensitive to aluminum than M. malabathricum.

The vacuolar channel VvALMT9 mediates malate and tartrate accumulation in berries of Vitis vinifera.

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De Angeli, Alexis; Baetz, Ulrike; Francisco, Rita; Zhang, Jingbo; Chaves, Maria Manuela; Regalado, Ana

2013-08-01

Vitis vinifera L. represents an economically important fruit species. Grape and wine flavour is made from a complex set of compounds. The acidity of berries is a major parameter in determining grape berry quality for wine making and fruit consumption. Despite the importance of malic and tartaric acid (TA) storage and transport for grape berry acidity, no vacuolar transporter for malate or tartrate has been identified so far. Some members of the aluminium-activated malate transporter (ALMT) anion channel family from Arabidopsis thaliana have been shown to be involved in mediating malate fluxes across the tonoplast. Therefore, we hypothesised that a homologue of these channels could have a similar role in V. vinifera grape berries. We identified homologues of the Arabidopsis vacuolar anion channel AtALMT9 through a TBLASTX search on the V. vinifera genome database. We cloned the closest homologue of AtALMT9 from grape berry cDNA and designated it VvALMT9. The expression profile revealed that VvALMT9 is constitutively expressed in berry mesocarp tissue and that its transcription level increases during fruit maturation. Moreover, we found that VvALMT9 is targeted to the vacuolar membrane. Using patch-clamp analysis, we could show that, besides malate, VvALMT9 mediates tartrate currents which are higher than in its Arabidopsis homologue. In summary, in the present study we provide evidence that VvALMT9 is a vacuolar malate channel expressed in grape berries. Interestingly, in V. vinifera, a tartrate-producing plant, the permeability of the channel is apparently adjusted to TA.

Catalytic properties of thermophilic lactate dehydrogenase and halophilic malate dehydrogenase at high temperature and low water activity.

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Hecht, K; Wrba, A; Jaenicke, R

1989-07-15

Thermophilic lactate dehydrogenases from Thermotoga maritima and Bacillus stearothermophilus are stable up to temperature limits close to the optimum growth temperature of their parent organisms. Their catalytic properties are anomalous in that Km shows a drastic increase with increasing temperature. At low temperatures, the effect levels off. Extreme halophilic malate dehydrogenase from Halobacterium marismortui exhibits a similar anomaly. Increasing salt concentration (NaCl) leads to an optimum curve for Km, oxaloacctate while Km, NADH remains constant. Previous claims that the activity of halophilic malate dehydrogenase shows a maximum at 1.25 M NaCl are caused by limiting substrate concentration; at substrate saturation, specific activity of halophilic malate dehydrogenase reaches a constant value at ionic strengths I greater than or equal to 1 M. Non-halophilic (mitochondrial) malate dehydrogenase shows Km characteristics similar to those observed for the halophilic enzyme. The drastic decrease in specific activity of the mitochondrial enzyme at elevated salt concentrations is caused by the salt-induced increase in rigidity of the enzyme, rather than gross structural changes.

Ammonium intensifies CAM photosynthesis and counteracts drought effects by increasing malate transport and antioxidant capacity in Guzmania monostachia.

Science.gov (United States)

Pereira, Paula Natália; Gaspar, Marília; Smith, J Andrew C; Mercier, Helenice

2018-04-09

Guzmania monostachia (Bromeliaceae) is a tropical epiphyte capable of up-regulating crassulacean acid metabolism (CAM) in its photosynthetic tissues in response to changing nutrient and water availability. Previous studies have shown that under drought there is a gradient of increasing CAM expression from the basal (youngest) to the apical (oldest) portion of the leaves, and additionally that nitrogen deficiency can further increase CAM intensity in the leaf apex of this bromeliad. The present study investigated the inter-relationships between nitrogen source (nitrate and/or ammonium) and water deficit in regulating CAM expression in G. monostachia leaves. The highest CAM activity was observed under ammonium nutrition in combination with water deficit. This was associated with enhanced activity of the key enzyme phosphoenolpyruvate carboxylase, elevated rates of ATP- and PPi-dependent proton transport at the vacuolar membrane in the presence of malate, and increased transcript levels of the vacuolar malate channel-encoding gene, ALMT. Water deficit was consistently associated with higher levels of total soluble sugars, which were maximal under ammonium nutrition, as were the activities of several antioxidant enzymes (superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase). Thus, ammonium nutrition, whilst associated with the highest degree of CAM induction in G. monostachia, also mitigates the effects of water deficit by osmotic adjustment and can limit oxidative damage in the leaves of this bromeliad under conditions that may be typical of its epiphytic habitat.

[Process and mechanism of plants in overcoming acid soil aluminum stress].

Science.gov (United States)

Zhao, Tian-Long; Xie, Guang-Ning; Zhang, Xiao-Xia; Qiu, Lin-Quan; Wang, Na; Zhang, Su-Zhi

2013-10-01

Aluminum (Al) stress is one of the most important factors affecting the plant growth on acid soil. Currently, global soil acidification further intensifies the Al stress. Plants can detoxify Al via the chelation of ionic Al and organic acids to store the ionic Al in vacuoles and extrude it from roots. The Al extrusion is mainly performed by the membrane-localized anion channel proteins Al(3+)-activated malate transporter (ALMT) and multi-drug and toxin extrusion (MATE). The genes encoding ABC transporter and zinc-finger protein conferred plant Al tolerance have also been found. The identification of these Al-resistant genes makes it possible to increase the Al resistance of crop plants and enhance their production by the biological methods such as gene transformation and mark-associated breeding. The key problems needed to be solved and the possible directions in the researches of plant Al stress resistance were proposed.

Role of the plasma membrane H(+)-ATPase in the regulation of organic acid exudation under aluminum toxicity and phosphorus deficiency.

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Yu, Wenqian; Kan, Qi; Zhang, Jiarong; Zeng, Bingjie; Chen, Qi

2016-01-01

Aluminum (Al) toxicity and phosphorus (P) deficiency are 2 major limiting factors for plant growth and crop production in acidic soils. Organic acids exuded from roots have been generally regarded as a major resistance mechanism to Al toxicity and P deficiency. The exudation of organic acids is mediated by membrane-localized OA transporters, such as ALMT (Al-activated malate transporter) and MATE (multidrug and toxic compound extrusion). Beside on up-regulation expression of organic acids transporter gene, transcriptional, translational and post-translational regulation of the plasma membrane H(+)-ATPase are also involved in organic acid release process under Al toxicity and P deficiency. This mini-review summarizes the current knowledge about this field of study on the role of the plasma membrane H(+)-ATPase in organic acid exudation under Al toxicity and P deficiency conditions.

Magnitude of malate-aspartate reduced nicotinamide adenine dinucleotide shuttle activity in intact respiring tumor cells.

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Greenhouse, W V; Lehninger, A L

1977-11-01

Measurements of respiration, CO2 and lactate production, and changes in the levels of various key metabolites of the glycolytic sequence and tricarboxylic acid cycle were made on five lines of rodent ascites tumor cells (two strains of Ehrlich ascites tumor cells, Krebs II carcinoma, AS-30D carcinoma, and L1210 cells) incubated aerobically in the presence of uniformly labeled D-[14C]glucose. From these data, as well as earlier evidence demonstrating that the reduced nicotinamide adenine dinucleotide (NADH) shuttle in these cells requires a transaminase step and is thus identified as the malate-aspartate shuttle (W.V.V. Greenhouse and A.L. Lehninger, Cancer Res., 36: 1392-1396, 1976), metabolic flux diagrams were constructed for the five cell lines. These diagrams show the relative rates of glycolysis, the tricarboxylic acid cycle, electron transport, and the malate-aspartate shuttle in these tumors. Large amounts of cytosolic NADH were oxidized by the mitochondrial respiratory chain via the NADH shuttle, comprising anywhere from about 20 to 80% of the total flow of reducing equivalents to oxygen in these tumors. Calculations of the sources of energy for adenosine triphosphate synthesis indicated that on the average about one-third of the respiratory adenosine triphosphate is generated by electron flow originating from cytosolic NADH via the malate-aspartate shuttle.

Role of the plasma membrane H+-ATPase in the regulation of organic acid exudation under aluminum toxicity and phosphorus deficiency

Science.gov (United States)

Yu, Wenqian; Kan, Qi; Zhang, Jiarong; Zeng, Bingjie; Chen, Qi

2016-01-01

Aluminum (Al) toxicity and phosphorus (P) deficiency are 2 major limiting factors for plant growth and crop production in acidic soils. Organic acids exuded from roots have been generally regarded as a major resistance mechanism to Al toxicity and P deficiency. The exudation of organic acids is mediated by membrane-localized OA transporters, such as ALMT (Al-activated malate transporter) and MATE (multidrug and toxic compound extrusion). Beside on up-regulation expression of organic acids transporter gene, transcriptional, translational and post-translational regulation of the plasma membrane H+-ATPase are also involved in organic acid release process under Al toxicity and P deficiency. This mini-review summarizes the current knowledge about this field of study on the role of the plasma membrane H+-ATPase in organic acid exudation under Al toxicity and P deficiency conditions. PMID:26713714

Proteomic analysis of a high aluminum tolerant yeast Rhodotorula taiwanensis RS1 in response to aluminum stress.

Science.gov (United States)

Wang, Chao; Wang, Chang Yi; Zhao, Xue Qiang; Chen, Rong Fu; Lan, Ping; Shen, Ren Fang

2013-10-01

Rhodotorula taiwanensis RS1 is a high-aluminum (Al)-tolerant yeast that can survive in Al concentrations up to 200mM. The mechanisms for the high Al tolerance of R. taiwanensis RS1 are not well understood. To investigate the molecular mechanisms underlying Al tolerance and toxicity in R. taiwanensis RS1, Al toxicity-induced changes in the total soluble protein profile were analyzed using two-dimensional gel electrophoresis (2-DE) coupled with mass spectrometry. A total of 33 differentially expressed proteins responding to Al stress were identified from approximately 850 reproducibly detected proteins. Among them, the abundance of 29 proteins decreased and 4 increased. In the presence of 100mM Al, the abundance of proteins involved in DNA transcription, protein translation, DNA defense, Golgi functions and glucose metabolism was decreased. By contrast, Al treatment led to increased abundance of malate dehydrogenase, which correlated with increased malate dehydrogenase activity and the accumulation of intracellular citrate, suggesting that Al-induced intracellular citrate could play an important role in detoxification of Al in R. taiwanensis RS1. © 2013.

Mutation in the peroxin-coding gene PEX22 contributing to high malate production in Saccharomyces cerevisiae.

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Negoro, Hiroaki; Sakamoto, Mitsuru; Kotaka, Atsushi; Matsumura, Kengo; Hata, Yoji

2018-02-01

Saccharomyces cerevisiae produces organic acids such as succinate, acetate, and malate during alcoholic fermentation. Since malate contributes to the pleasant taste of sake (a Japanese alcoholic beverage), various methods for breeding high-malate-producing yeast strains have been developed. Here, a high-malate-producing yeast strain F-701H was isolated. This mutant was sensitive to dimethyl succinate (DMS) and harbored a nonsense mutation in the peroxin gene PEX22, which was identified as the cause of high malate production by comparative genome analysis. This mutation, which appeared to cause Pex22p dysfunction, was sufficient to confer increased malate productivity and DMS sensitivity to yeast cells. Next, we investigated the mechanism by which this mutation led to high malate production in yeast cells. Peroxins, such as Pex22p, maintain peroxisomal biogenesis. Analysis of 29 PEX disruptants revealed an increased malate production by deletion of the genes encoding peroxins responsible for importing proteins (containing peroxisomal targeting signal 1, PTS1) into the peroxisomal matrix, and those responsible for the assembly of peroxins themselves in the peroxisomal membrane. A defect in peroxisomal malate dehydrogenase (Mdh3p), harboring endogenous PTS1, inhibited the high malate-producing phenotype in the PEX22 mutant. Moreover, Mdh3p, which was normally sorted to the peroxisomal matrix, was potentially mislocalized to the cytosol in the PEX22 mutant. This suggested that an increase in malate production resulted from the mislocalization of Mdh3p from the peroxisome to the cytoplasm due to the loss of peroxin-mediated transportation. Thus, the present study revealed a novel mechanism for organic acid productions in yeast during sake brewing. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Cellular distribution, purification and electrophoretic properties of malate dehydrogenase in Trichuris ovis and inhibition by benzimidazoles and pyrimidine derivatives.

Science.gov (United States)

Sanchez-Moreno, M; Ortega, J E; Valero, A

1989-12-01

High levels of malate dehydrogenase were found in Trichuris ovis. Two molecular forms of the enzyme, of different cellular location and electrophoretic pattern, were isolated and purified. The activity of soluble malate dehydrogenase was greater than that of mitochondrial malate dehydrogenase. Both forms also displayed different electrophoretic profiles in comparison with purified extracts from goat (Capra hircus) liver. Substrate concentration directly affected enzyme activity. Host and parasite malate dehydrogenase activity were both inhibited by a series of benzimidazoles and pyrimidine-derived compounds, some of which markedly reduced parasite enzyme activity, but not host enzyme activity. Percentage inhibition by some pyrimidine derivatives was greater than that produced by benzimidazoles.

Electrical transport through single-wall carbon nanotube-anodic aluminum oxide-aluminum heterostructures

International Nuclear Information System (INIS)

Kukkola, Jarmo; Rautio, Aatto; Sala, Giovanni; Pino, Flavio; Toth, Geza; Leino, Anne-Riikka; Maeklin, Jani; Jantunen, Heli; Uusimaeki, Antti; Kordas, Krisztian; Gracia, Eduardo; Terrones, Mauricio; Shchukarev, Andrey; Mikkola, Jyri-Pekka

2010-01-01

Aluminum foils were anodized in sulfuric acid solution to form thick porous anodic aluminum oxide (AAO) films of thickness ∼6 μm. Electrodes of carboxyl-functionalized single-wall carbon nanotube (SWCNT) thin films were inkjet printed on the anodic oxide layer and the electrical characteristics of the as-obtained SWCNT-AAO-Al structures were studied. Nonlinear current-voltage transport and strong temperature dependence of conduction through the structure was measured. The microstructure and chemical composition of the anodic oxide layer was analyzed using transmission and scanning electron microscopy as well as x-ray photoelectron spectroscopy. Schottky emission at the SWCNT-AAO and AAO-Al interfaces allowed by impurity states in the anodic aluminum oxide film together with ionic surface conduction on the pore walls of AAO gives a reasonable explanation for the measured electrical conduction. Calcined AAO is proposed as a dielectric material for SWCNT-field effect transistors.

Akkumulation von L-Malat und D-Lactat in Arabidopsis thaliana und Laccase/HBT-vermittelte Delignifizierung von Spartina alterniflora und Phragmites australis

OpenAIRE

Heil, Alexander

2016-01-01

The current work contains two projects "Accumulation of L-malate and D-lactate in Arabidopsis thaliana" (A) "Laccase/HBT mediated delignification of Spartina alterniflora and Phragmites australis" (B). In project A, L-malate and D-lactate accumulated in A. thaliana plants. The accumulation of L-malate is carried out by modification of the plant metabolism with the enzymes PEPC, MDH and the tonoplast dicarboxylate transporter (TDT). Gene pepci2 (Hydrilla verticillata), mdh5 (Zea mays) and tdt ...

Common catabolic enzyme patterns in a microplankton community of the Humboldt Current System off northern and central-south Chile: Malate dehydrogenase activity as an index of water-column metabolism in an oxygen minimum zone

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González, R. R.; Quiñones, R. A.

2009-07-01

An extensive subsurface oxygen minimum zone off northern and central-south Chile, associated with the Peru-Chile undercurrent, has important effects on the metabolism of the organisms inhabiting therein. Planktonic species deal with the hypoxic and anoxic environments by relying on biochemical as well as physiological processes related to their anaerobic metabolisms. Here we characterize, for the first time, the potential enzymatic activities involved in the aerobic and anaerobic energy production pathways of microplanktonic organisms (oxygen concentration and microplanktonic biomass in the oxygen minimum zone and adjacent areas of the Humboldt Current System water column. Our results demonstrate significant potential enzymatic activity of catabolic pathways in the oxygen minimum zone. Malate dehydrogenase had the highest oxidizing activity of nicotinamide adenine dinucleotide (reduced form) in the batch of catabolic enzymatic activities assayed, including potential pyruvate oxidoreductases activity, the electron transport system, and dissimilatory nitrate reductase. Malate dehydrogenase correlated significantly with almost all the enzymes analyzed within and above the oxygen minimum zone, and also with the oxygen concentration and microplankton biomass in the water column of the Humboldt Current System, especially in the oxygen minimum zone off Iquique. These results suggest a possible specific pattern for the catabolic activity of the microplanktonic realm associated with the oxygen minimum zone spread along the Humboldt Current System off Chile. We hypothesize that malate dehydrogenase activity could be an appropriate indicator of microplankton catabolism in the oxygen minimum zone and adjacent areas.

A molecular, genetic and physiological analysis of plant aluminum tolerance (abstract)

International Nuclear Information System (INIS)

Pineros, M.

2005-01-01

Aluminum (Al) toxicity is an important agronomic trait, limiting crop production on acid soils that comprise up to 50% of the world's potentially arable lands. A significant genetic variation in Al tolerance exists in both crop plants and Arabidopsis. The exploitation of this genetic variation to breed crops with increased Al tolerance has been a productive and active area of research, however, the underlying molecular, genetic and physiological bases are still not well understood. Only very recently was the first Al tolerance gene, ALMT1, isolated in wheat and shown to be a novel Al-activated malate transporter. Work in our laboratory has focused on using integrated genomic (gene and protein expression profiling), molecular genetic and physiological approaches to identify novel Al tolerance genes and the physiological mechanisms they control in the cereal crops maize and sorghum, and also in arabidopsis. In sorghum we had previously shown that Al tolerance is the result of a single locus, Alt/sub SB/ which maps to the top of sorghum chromosome 3 in a region totally distinct from where the major Al tolerance maps in wheat and other related members of the Triticeae. Very recently, we have used map-based cloning techniques in sorghum to clone Alt/sub SB/ and have found it is a novel Al tolerance gene. Here we will present a molecular characterization of the Alt/sub SB/ gene and also the physiological mechanism of sorghum Al tolerance it controls. In arabidopsis, we have previously shown that Al tolerance is a quantitative trait and have identified two major Al tolerance QTL on chromosomes 1 and 5. These genes function to confer tolerance via Al via activated root malate release. We found that a member of the arabidopsis gene family that is a close homolog to wheat ALMT1 maps near the largest tolerance QTL on chromosome 1 and have also found this gene encodes the Al-activated malate transport involved in arabidopsis Al tolerance. However, we have clear molecular

Photosynthetic metabolism of malate and aspartate in Flaveria trinervia a C4 dicot

International Nuclear Information System (INIS)

Moore, B.A.

1986-01-01

C 4 species are known to vary in their apparent relative use of malate and aspartate to mediate carbon flux through the C 4 cycle. These studies investigate some of the adjustments in photosynthetic carbon metabolism that occur during a dark to light transition and during expansion of leaves of Flaveria trinervia, a C 4 dicot. Enzyme localization studies with isolated leaf mesophyll and bundle sheath protoplasts, indicated that both C 4 acids are formed in the mesophyll chloroplast, and that aspartate is metabolized to malate in the bundle sheath chloroplast prior to decaroxylation there. During photosynthetic induction, the partitioning of 14 CO 2 between malate and aspartate showed a single oscillation of increased aspartate labelling after 5 min of illumination. Turnover of [4-14C] (malate plus aspartate) was slow initially during illumination, prior to establishment of active pools of C 4 cycle metabolites

Modeling the vacuolar storage of malate shed lights on pre- and post-harvest fruit acidity.

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Etienne, Audrey; Génard, Michel; Lobit, Philippe; Bugaud, Christophe

2014-11-18

Malate is one of the most important organic acids in many fruits and its concentration plays a critical role in organoleptic properties. Several studies suggest that malate accumulation in fruit cells is controlled at the level of vacuolar storage. However, the regulation of vacuolar malate storage throughout fruit development, and the origins of the phenotypic variability of the malate concentration within fruit species remain to be clarified. In the present study, we adapted the mechanistic model of vacuolar storage proposed by Lobit et al. in order to study the accumulation of malate in pre and postharvest fruits. The main adaptation concerned the variation of the free energy of ATP hydrolysis during fruit development. Banana fruit was taken as a reference because it has the particularity of having separate growth and post-harvest ripening stages, during which malate concentration undergoes substantial changes. Moreover, the concentration of malate in banana pulp varies greatly among cultivars which make possible to use the model as a tool to analyze the genotypic variability. The model was calibrated and validated using data sets from three cultivars with contrasting malate accumulation, grown under different fruit loads and potassium supplies, and harvested at different stages. The model predicted the pre and post-harvest dynamics of malate concentration with fairly good accuracy for the three cultivars (mean RRMSE = 0.25-0.42). The sensitivity of the model to parameters and input variables was analyzed. According to the model, vacuolar composition, in particular potassium and organic acid concentrations, had an important effect on malate accumulation. The model suggested that rising temperatures depressed malate accumulation. The model also helped distinguish differences in malate concentration among the three cultivars and between the pre and post-harvest stages by highlighting the probable importance of proton pump activity and particularly of the free

C-terminus-mediated voltage gating of Arabidopsis guard cell anion channel QUAC1.

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Mumm, Patrick; Imes, Dennis; Martinoia, Enrico; Al-Rasheid, Khaled A S; Geiger, Dietmar; Marten, Irene; Hedrich, Rainer

2013-09-01

Anion transporters in plants play a fundamental role in volume regulation and signaling. Currently, two plasma membrane-located anion channel families—SLAC/SLAH and ALMT—are known. Among the ALMT family, the root-expressed ALuminium-activated Malate Transporter 1 was identified by comparison of aluminum-tolerant and Al(3+)-sensitive wheat cultivars and was subsequently shown to mediate voltage-independent malate currents. In contrast, ALMT12/QUAC1 (QUickly activating Anion Channel1) is expressed in guard cells transporting malate in an Al(3+)-insensitive and highly voltage-dependent manner. So far, no information is available about the structure and mechanism of voltage-dependent gating with the QUAC1 channel protein. Here, we analyzed gating of QUAC1-type currents in the plasma membrane of guard cells and QUAC1-expressing oocytes revealing similar voltage dependencies and activation–deactivation kinetics. In the heterologous expression system, QUAC1 was electrophysiologically characterized at increasing extra- and intracellular malate concentrations. Thereby, malate additively stimulated the voltage-dependent QUAC1 activity. In search of structural determinants of the gating process, we could not identify transmembrane domains common for voltage-sensitive channels. However, site-directed mutations and deletions at the C-terminus of QUAC1 resulted in altered voltage-dependent channel activity. Interestingly, the replacement of a single glutamate residue, which is conserved in ALMT channels from different clades, by an alanine disrupted QUAC1 activity. Together with C- and N-terminal tagging, these results indicate that the cytosolic C-terminus is involved in the voltage-dependent gating mechanism of QUAC1.

Post-irradiation inactivation, protection, and repair of the sulfhydryl enzyme malate synthase

International Nuclear Information System (INIS)

Durchschlag, H.; Zipper, P.

1985-01-01

Malate synthase from baker's yeast, a trimeric sulfhydryl enzyme with one essential sulfhydryl group per subunit, was inactivated by 2 kGy X-irradiation in air-saturated aqueous solution (enzyme concentration: 0.5 mg/ml). The radiation induced changes of enzymic activity were registered at about 0,30,60 h after irradiation. To elucidate the role of OH - , O 2 , and H 2 O 2 in the X-ray inactivation of the enzyme, experiments were performed in the absence of presence of different concentrations of specific additives (formate, superoxide dismutase, catalase). These additives were added to malate synthase solutions before or after X-irradiation. Moreover, repairs of inactivated malate synthase were initiated at about 0 or 30 h after irradiation by means of the sulfhydryl agent dithiothreitol. Experiments yielded the following results: 1. Irradiation of malate synthase in the absence of additives inactivated the enzyme immediately to a residual activity Asub(r)=3% (corresponding to a D 37 =0.6 kGy), and led to further slow inactivation in the post-irradiation phase. Repairs, initiated at different times after irradiation, restored enzymic activity considerably. The repair initiated at t=0 led to Asub(r)=21%; repairs started later on resulted in somewhat lower activities. The decay of reparability, however, was found to progress more slowly than post-irradiation inactivation itself. After completion of repair the activities of repaired samples did not decrease significantly. 2. The presence of specific additives during irradiation caused significant protective effects against primary inactivation. The protection by formate was very pronounced (e.g., Asub(r)=72% and D 37 =6 kGy for 100 mM formate). The presence of catalytic amounts of superoxide dismutase and/or catalase exhibited only minor effects, depending on the presence and concentration of formate. (orig.)

Impaired pH homeostasis in Arabidopsis lacking the vacuolar dicarboxylate transporter and analysis of carboxylic acid transport across the tonoplast.

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Hurth, Marco Alois; Suh, Su Jeoung; Kretzschmar, Tobias; Geis, Tina; Bregante, Monica; Gambale, Franco; Martinoia, Enrico; Neuhaus, H Ekkehard

2005-03-01

Arabidopsis (Arabidopsis thaliana) mutants lacking the tonoplastic malate transporter AttDT (A. thaliana tonoplast dicarboxylate transporter) and wild-type plants showed no phenotypic differences when grown under standard conditions. To identify putative metabolic changes in AttDT knock-out plants, we provoked a metabolic scenario connected to an increased consumption of dicarboxylates. Acidification of leaf discs stimulated dicarboxylate consumption and led to extremely low levels of dicarboxylates in mutants. To investigate whether reduced dicarboxylate concentrations in mutant leaf cells and, hence, reduced capacity to produce OH(-) to overcome acidification might affect metabolism, we measured photosynthetic oxygen evolution under conditions where the cytosol is acidified. AttDT::tDNA protoplasts showed a much stronger inhibition of oxygen evolution at low pH values when compared to wild-type protoplasts. Apparently citrate, which is present in higher amounts in knock-out plants, is not able to replace dicarboxylates to overcome acidification. To raise more information on the cellular level, we performed localization studies of carboxylates. Although the total pool of carboxylates in mutant vacuoles was nearly unaltered, these organelles contained a lower proportion of malate and fumarate and a higher proportion of citrate when compared to wild-type vacuoles. These alterations concur with the observation that radioactively labeled malate and citrate are transported into Arabidopsis vacuoles by different carriers. In addition, wild-type vacuoles and corresponding organelles from AttDT::tDNA mutants exhibited similar malate channel activities. In conclusion, these results show that Arabidopsis vacuoles contain at least two transporters and a channel for dicarboxylates and citrate and that the activity of AttDT is critical for regulation of pH homeostasis.

Occurrence of the malate-aspartate shuttle in various tumor types.

Science.gov (United States)

Greenhouse, W V; Lehninger, A L

1976-04-01

The activity of the malate-aspartate shuttle for the reoxidation of cytoplasmic reduced nicotinamide adenine dinucleotide (NADH) by mitochondria was assessed in six lines of rodent ascites tumor cells (two strains of Ehrlich ascites carcinoma, Krebs II carcinoma, Novikoff hepatoma, AS-30D hepatoma, and L1210 mouse leukemia). All the tumor cells examined showed mitochondrial reoxidation of cytoplasmic NADH, as evidenced by the accumulation of pyruvate when the cells were incubated aerobically with L-lactate. Reoxidation of cytoplasmic NADH thus generated was completely inhibited by the transaminase inhibitor aminooxyacetate. The involvement of the respiratory chain in the reoxidation of cytoplasmic NADH was demonstrated by the action of cyanide, rotenone, and antimycin A, which strongly inhibited the formation of pyruvate from added L-lactate. Compounds that inhibit the carrier-mediated entry of malate into mitochondria, such as butylmalonate, benzenetricarboxylate, and iodobenzylmalonate, also inhibited the accumulation of pyruvate from added L-lactate by the tumor cells. The maximal rate of the malate-aspartate shuttle was established by addtion of arsenite to inhibit the mitochondrial oxidation of the pyruvate formed from added lactate. The capacity of the various tumor lines for the reoxidation of cytoplasmic NADH via the malate-aspartate shuttle approaches 20% of the total respiratory rate of the cells and thus appears to be sufficient to account for the mitochondrial reoxidation of that fraction of glycolytic NADH not reoxidized by pyruvate and lactate dehydrognenase in the cytoplasm.

Type 2 Diabetic Rats on Diet Supplemented With Chromium Malate Show Improved Glycometabolism, Glycometabolism-Related Enzyme Levels and Lipid Metabolism

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Feng, Weiwei; Zhao, Ting; Mao, Guanghua; Wang, Wei; Feng, Yun; Li, Fang; Zheng, Daheng; Wu, Huiyu; Jin, Dun; Yang, Liuqing; Wu, Xiangyang

2015-01-01

Our previous study showed that chromium malate improved the regulation of blood glucose in mice with alloxan-induced diabetes. The present study was designed to evaluate the effect of chromium malate on glycometabolism, glycometabolism-related enzymes and lipid metabolism in type 2 diabetic rats. Our results showed that fasting blood glucose, serum insulin level, insulin resistance index and C-peptide level in the high dose group had a significant downward trend when compared with the model group, chromium picolinate group and chromium trichloride group. The hepatic glycogen, glucose-6-phosphate dehydrogenase, glucokinase, Glut4, phosphor-AMPKβ1 and Akt levels in the high dose group were significantly higher than those of the model, chromium picolinate and chromium trichloride groups. Chromium malate in a high dose group can significantly increase high density lipoprotein cholesterol level while decreasing the total cholesterol, low density lipoprotein cholesterol and triglyceride levels when compared with chromium picolinate and chromium trichloride. The serum chromium content in chromium malate and chromium picolinate group is significantly higher than that of the chromium trichloride group. The results indicated that the curative effects of chromium malate on glycometabolism, glycometabolism-related enzymes and lipid metabolism changes are better than those of chromium picolinate and chromium trichloride. Chromium malate contributes to glucose uptake and transport in order to improved glycometabolism and glycometabolism-related enzymes. PMID:25942313

Impaired pH Homeostasis in Arabidopsis Lacking the Vacuolar Dicarboxylate Transporter and Analysis of Carboxylic Acid Transport across the Tonoplast1

Science.gov (United States)

Hurth, Marco Alois; Suh, Su Jeoung; Kretzschmar, Tobias; Geis, Tina; Bregante, Monica; Gambale, Franco; Martinoia, Enrico; Neuhaus, H. Ekkehard

2005-01-01

Arabidopsis (Arabidopsis thaliana) mutants lacking the tonoplastic malate transporter AttDT (A. thaliana tonoplast dicarboxylate transporter) and wild-type plants showed no phenotypic differences when grown under standard conditions. To identify putative metabolic changes in AttDT knock-out plants, we provoked a metabolic scenario connected to an increased consumption of dicarboxylates. Acidification of leaf discs stimulated dicarboxylate consumption and led to extremely low levels of dicarboxylates in mutants. To investigate whether reduced dicarboxylate concentrations in mutant leaf cells and, hence, reduced capacity to produce OH− to overcome acidification might affect metabolism, we measured photosynthetic oxygen evolution under conditions where the cytosol is acidified. AttDT::tDNA protoplasts showed a much stronger inhibition of oxygen evolution at low pH values when compared to wild-type protoplasts. Apparently citrate, which is present in higher amounts in knock-out plants, is not able to replace dicarboxylates to overcome acidification. To raise more information on the cellular level, we performed localization studies of carboxylates. Although the total pool of carboxylates in mutant vacuoles was nearly unaltered, these organelles contained a lower proportion of malate and fumarate and a higher proportion of citrate when compared to wild-type vacuoles. These alterations concur with the observation that radioactively labeled malate and citrate are transported into Arabidopsis vacuoles by different carriers. In addition, wild-type vacuoles and corresponding organelles from AttDT::tDNA mutants exhibited similar malate channel activities. In conclusion, these results show that Arabidopsis vacuoles contain at least two transporters and a channel for dicarboxylates and citrate and that the activity of AttDT is critical for regulation of pH homeostasis. PMID:15728336

Are phloem-derived amino acids the origin of the elevated malate concentration in the xylem sap following mineral N starvation in soybean?

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Vitor, Simone C; do Amarante, Luciano; Sodek, Ladaslav

2018-05-16

A substantial increase in malate in the xylem sap of soybean subjected to mineral N starvation originates mainly from aspartate, a prominent amino acid of the phloem. A substantial increase in xylem malate was found when non-nodulated soybean plants were transferred to a N-free medium. Nodulated plants growing in the absence of mineral N and, therefore, dependent on symbiotic N 2 fixation also contained elevated concentrations of malate in the xylem sap. When either nitrate or ammonium was supplied, malate concentrations in the xylem sap were low, both for nodulated and non-nodulated plants. Evidence was obtained that the elevated malate concentration of the xylem was derived from amino acids supplied by the phloem. Aspartate was a prominent component of the phloem sap amino acids and, therefore, a potential source of malate. Supplying the roots of intact plants with 13 C-aspartate revealed that malate of the xylem sap was readily labelled under N starvation. A hypothetical scheme is proposed whereby aspartate supplied by the phloem is metabolised in the roots and the products of this metabolism cycled back to the shoot. Under N starvation, aspartate metabolism is diverted from asparagine synthesis to supply N for the synthesis of other amino acids via transaminase activity. The by-product of aspartate transaminase activity, oxaloacetate, is transformed to malate and its export accounts for much of the elevated concentration of malate found in the xylem sap. This mechanism represents a new additional role for malate during mineral N starvation of soybean, beyond that of charge balance.

Processes of malate catabolism during the anaerobic metabolism of grape berries

International Nuclear Information System (INIS)

Flanzy, C.; Andre, P.; Buret, M.; Chambroy, Y.; Garcia, P.

1976-01-01

In order to precise malate fate during the anaerobic metabolism of grape, malate- 3 - 14 C was injected into Carignan berries kept in darkness at 35 0 C under carbon dioxide atmosphere. The injection of labelled malate was effected in presence or not of non-labelled oxalate which inhibits malic enzyme (EC I.I.I.40). The analyses of the samples fixed after 3 and 7 days anaerobiosis concerned the titration of various substrates, organic acids, amino-acids and glycolysis products, and the measuring of the NADP + -malic enzyme (EC I.I.I.40) and malate dehydrogenase (EC I.I.I.40). Radioactivity is mainly observed in ethanol, amino-butyrate the non-separated group glycerate-shikimate and succinate. Malic enzyme acts in the first sequence of a process leading from malate to ethanol. Alanin synthesis seems to be stimulated in presence of oxalate. The results obtained and some hypotheses presented in the literature induce to suggest a utilization scheme for malate in the anaerobic metabolism of grape [fr

Association and linkage analysis of aluminum tolerance genes in maize.

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Allison M Krill

Full Text Available BACKGROUND: Aluminum (Al toxicity is a major worldwide constraint to crop productivity on acidic soils. Al becomes soluble at low pH, inhibiting root growth and severely reducing yields. Maize is an important staple food and commodity crop in acidic soil regions, especially in South America and Africa where these soils are very common. Al exclusion and intracellular tolerance have been suggested as two important mechanisms for Al tolerance in maize, but little is known about the underlying genetics. METHODOLOGY: An association panel of 282 diverse maize inbred lines and three F2 linkage populations with approximately 200 individuals each were used to study genetic variation in this complex trait. Al tolerance was measured as net root growth in nutrient solution under Al stress, which exhibited a wide range of variation between lines. Comparative and physiological genomics-based approaches were used to select 21 candidate genes for evaluation by association analysis. CONCLUSIONS: Six candidate genes had significant results from association analysis, but only four were confirmed by linkage analysis as putatively contributing to Al tolerance: Zea mays AltSB like (ZmASL, Zea mays aluminum-activated malate transporter2 (ALMT2, S-adenosyl-L-homocysteinase (SAHH, and Malic Enzyme (ME. These four candidate genes are high priority subjects for follow-up biochemical and physiological studies on the mechanisms of Al tolerance in maize. Immediately, elite haplotype-specific molecular markers can be developed for these four genes and used for efficient marker-assisted selection of superior alleles in Al tolerance maize breeding programs.

Cytosolic malate dehydrogenase regulates RANKL-mediated osteoclastogenesis via AMPK/c-Fos/NFATc1 signaling

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Oh, Se Jeong [Department of Oral Microbiology and Immunology, College of Dentistry, Wonkwang University, Iksan, Jeonbuk 54538 (Korea, Republic of); Gu, Dong Ryun [Department of Oral Microbiology and Immunology, College of Dentistry, Wonkwang University, Iksan, Jeonbuk 54538 (Korea, Republic of); Center for Metabolic Function Regulation (CMFR), School of Medicine, Wonkwang University, Iksan, Jeonbuk 54538 (Korea, Republic of); Jin, Su Hyun [Center for Metabolic Function Regulation (CMFR), School of Medicine, Wonkwang University, Iksan, Jeonbuk 54538 (Korea, Republic of); Park, Keun Ha [Department of Oral Microbiology and Immunology, College of Dentistry, Wonkwang University, Iksan, Jeonbuk 54538 (Korea, Republic of); Center for Metabolic Function Regulation (CMFR), School of Medicine, Wonkwang University, Iksan, Jeonbuk 54538 (Korea, Republic of); Lee, Seoung Hoon, E-mail: leesh2@wku.ac.kr [Department of Oral Microbiology and Immunology, College of Dentistry, Wonkwang University, Iksan, Jeonbuk 54538 (Korea, Republic of); Center for Metabolic Function Regulation (CMFR), School of Medicine, Wonkwang University, Iksan, Jeonbuk 54538 (Korea, Republic of); Wonkwang Institute of Biomaterials and Implant, Wonkwang University, Iksan, Jeonbuk 54538 (Korea, Republic of)

2016-06-17

Cytosolic malate dehydrogenase (malate dehydrogenase 1, MDH1) plays pivotal roles in the malate/aspartate shuttle that might modulate metabolism between the cytosol and mitochondria. In this study, we investigated the role of MDH1 in osteoclast differentiation and formation. MDH1 expression was induced by receptor activator of nuclear factor kappa-B ligand (RANKL) treatment. Knockdown of MDH1 by infection with retrovirus containing MDH1-specific shRNA (shMDH1) reduced mature osteoclast formation and bone resorption activity. Moreover, the expression of marker genes associated with osteoclast differentiation was downregulated by shMDH1 treatment, suggesting a role of MDH1 in osteoclast differentiation. In addition, intracellular ATP production was reduced following the activation of adenosine 5′ monophosphate-activated protein kinase (AMPK), a cellular energy sensor and negative regulator of RANKL-induced osteoclast differentiation, in shMDH1-infected osteoclasts compared to control cells. In addition, the expression of c-Fos and nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), a critical transcription factor of osteoclastogenesis, was decreased with MDH1 knockdown during RANKL-mediated osteoclast differentiation. These findings provide strong evidence that MDH1 plays a critical role in osteoclast differentiation and function via modulation of the intracellular energy status, which might affect AMPK activity and NFATc1 expression.

Cytosolic malate dehydrogenase regulates RANKL-mediated osteoclastogenesis via AMPK/c-Fos/NFATc1 signaling

International Nuclear Information System (INIS)

Oh, Se Jeong; Gu, Dong Ryun; Jin, Su Hyun; Park, Keun Ha; Lee, Seoung Hoon

2016-01-01

Cytosolic malate dehydrogenase (malate dehydrogenase 1, MDH1) plays pivotal roles in the malate/aspartate shuttle that might modulate metabolism between the cytosol and mitochondria. In this study, we investigated the role of MDH1 in osteoclast differentiation and formation. MDH1 expression was induced by receptor activator of nuclear factor kappa-B ligand (RANKL) treatment. Knockdown of MDH1 by infection with retrovirus containing MDH1-specific shRNA (shMDH1) reduced mature osteoclast formation and bone resorption activity. Moreover, the expression of marker genes associated with osteoclast differentiation was downregulated by shMDH1 treatment, suggesting a role of MDH1 in osteoclast differentiation. In addition, intracellular ATP production was reduced following the activation of adenosine 5′ monophosphate-activated protein kinase (AMPK), a cellular energy sensor and negative regulator of RANKL-induced osteoclast differentiation, in shMDH1-infected osteoclasts compared to control cells. In addition, the expression of c-Fos and nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), a critical transcription factor of osteoclastogenesis, was decreased with MDH1 knockdown during RANKL-mediated osteoclast differentiation. These findings provide strong evidence that MDH1 plays a critical role in osteoclast differentiation and function via modulation of the intracellular energy status, which might affect AMPK activity and NFATc1 expression.

Long Non-Coding RNA MALAT1 Mediates Transforming Growth Factor Beta1-Induced Epithelial-Mesenchymal Transition of Retinal Pigment Epithelial Cells.

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Shuai Yang

Full Text Available To study the role of long non-coding RNA (lncRNA MALAT1 in transforming growth factor beta 1 (TGF-β1-induced epithelial-mesenchymal transition (EMT of retinal pigment epithelial (RPE cells.ARPE-19 cells were cultured and exposed to TGF-β1. The EMT of APRE-19 cells is confirmed by morphological change, as well as the increased expression of alpha-smooth muscle actin (αSMA and fibronectin, and the down-regulation of E-cadherin and Zona occludin-1(ZO-1 at both mRNA and protein levels. The expression of lncRNA MALAT1 in RPE cells were detected by quantitative real-time PCR. Knockdown of MALAT1 was achieved by transfecting a small interfering RNA (SiRNA. The effect of inhibition of MALAT1 on EMT, migration, proliferation, and TGFβ signalings were observed. MALAT1 expression was also detected in primary RPE cells incubated with proliferative vitreoretinopathy (PVR vitreous samples.The expression of MALAT1 is significantly increased in RPE cells incubated with TGFβ1. MALAT1 silencing attenuates TGFβ1-induced EMT, migration, and proliferation of RPE cells, at least partially through activating Smad2/3 signaling. MALAT1 is also significantly increased in primary RPE cells incubated with PVR vitreous samples.LncRNA MALAT1 is involved in TGFβ1-induced EMT of human RPE cells and provides new understandings for the pathogenesis of PVR.

Induction of long noncoding RNA MALAT1 in hypoxic mice

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Lelli A

2015-10-01

Full Text Available Aurelia Lelli,1,2,* Karen A Nolan,1,2,* Sara Santambrogio,1,2 Ana Filipa Gonçalves,1,2 Miriam J Schönenberger,1,2 Anna Guinot,1,2 Ian J Frew,1,2 Hugo H Marti,3 David Hoogewijs,1,2,4 Roland H Wenger1,2 1Institute of Physiology and Zurich Center for Human Physiology (ZIHP, University of Zurich, Zurich, Switzerland; 2National Center of Competence in Research "Kidney.CH", Zurich, Switzerland; 3Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany; 4Institute of Physiology, University of Duisburg-Essen, Essen, Germany *These authors contributed equally to this work Abstract: Long thought to be “junk DNA”, in recent years it has become clear that a substantial fraction of intergenic genomic DNA is actually transcribed, forming long noncoding RNA (lncRNA. Like mRNA, lncRNA can also be spliced, capped, and polyadenylated, affecting a multitude of biological processes. While the molecular mechanisms underlying the function of lncRNAs have just begun to be elucidated, the conditional regulation of lncRNAs remains largely unexplored. In genome-wide studies our group and others recently found hypoxic transcriptional induction of a subset of lncRNAs, whereof nuclear-enriched abundant/autosomal transcript 1 (NEAT1 and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1 appear to be the lncRNAs most ubiquitously and most strongly induced by hypoxia in cultured cells. Hypoxia-inducible factor (HIF-2 rather than HIF-1 seems to be the preferred transcriptional activator of these lncRNAs. For the first time, we also found strong induction primarily of MALAT1 in organs of mice exposed to inspiratory hypoxia. Most abundant hypoxic levels of MALAT1 lncRNA were found in kidney and testis. In situ hybridization revealed that the hypoxic induction in the kidney was confined to proximal rather than distal tubular epithelial cells. Direct oxygen-dependent regulation of MALAT1 lncRNA was confirmed using isolated primary

Immobilization of malate dehydrogenase on carbon nanotubes for development of malate biosensor.

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Ruhal, A; Rana, J S; Kumar, S; Kumar, A

2012-12-22

An amperometric malic acid biosensor was developed by immobilizing malate dehydrogenase on multi-walled carbon nanotubes (MWCNT) coated on screen printed carbon electrode. The screen printed carbon electrode is made up of three electrodes viz., carbon as working, platinum as counter and silver as reference electrode. Detection of L-malic acid concentration provides important information about the ripening and shelf life of the fruits. The NADP specific malate dehydrogenase was immobilized on carboxylated multiwalled carbon nanotubes using cross linker EDC [1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide] on screen printed carbon electrode. An amperometric current was measured by differential pulse voltammetry (DPV) which increases with increasing concentrations of malic acid at fixed concentration of NADP. Enzyme electrode was characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The detection limit of malic acid by the sensor was 60 - 120 μM and sensitivity of the sensor was 60 μM with a response time of 60s. The usual detection methods of malic acid are nonspecific, time consuming and less sensitive. However, an amperometric malic acid nanosensor is quick, specific and more sensitive for detection of malic acid in test samples.

Prognostic value of long non-coding RNA MALAT1 in cancer patients.

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Wu, Yihua; Lu, Wei; Xu, Jinming; Shi, Yu; Zhang, Honghe; Xia, Dajing

2016-01-01

Metastasis associated in lung adenocarcinoma transcript 1 (MALAT1) was identified to be the first long non-coding RNA as a biomarker of independent prognostic value for early stage non-small cell lung cancer patient survival. In recent years, the association between upregulated tissue MALAT1 level and incidence of various cancers including bladder cancer, colorectal cancer, and renal cancer has been widely discussed. The aim of our present study was to assess the potential prognostic value of MALAT1 in various human cancers. PubMed, Embase, Ovid, and Cochrane Library databases were systematically searched, and eligible studies evaluating the prognostic value of MALAT1 in various cancers were included. Finally, 11 studies encompassing 1216 participants reporting with sufficient data were enrolled in the current meta-analysis. The pooled hazard ratio (HR) was 2.05 (95 % confidence interval (CI) 1.64-2.55, p < 0.01) for overall survival (OS) and 2.66 (95 % CI 1.86-3.80, p < 0.01) for disease-free survival (DFS). In conclusion, high tissue MALAT1 level was associated with an inferior clinical outcome in various cancers, suggesting that MALAT1 might serve as a potential prognostic biomarker for various cancers.

[A case of respiratory dyskinesia due to clebopride malate].

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Kawasaki, H; Yamamoto, M; Okayasu, H; Wakayama, Y

1991-08-01

Clebopride malate is therapeutically used for the treatment of peptic ulcer. This drug has potent antidopaminergic activity that causes acute dystonic reaction, parkinsonism and tardive dyskinesia as adverse effects. Here, we have reported an 86-year-old man who developed abnormal involuntary movement of respiratory muscles and lower limb muscles after this drug had been given for four months. This involuntary movement appeared spontaneously at resting state and disappeared during sleep. Surface EMG demonstrated a synchronous grouping discharge in m. orbicularis oris, m. sternocleidomastoideus and m. interstales which synchronized with diaphragmatic movement on cinefluorography. Involuntary movement of the lower limbs was synchronous bilaterally and had little relationship with diaphragmatic movement. This involuntary movement was irregular not only in rhythm but also in duration. According to this irregular nature, we diagnosed this involuntary movement as respiratory dyskinesia with limb dyskinesia that belongs to tardive dyskinesia. After cessation of clebopride malate limb dyskinesia disappeared rapidly and respiratory dyskinesia markedly decreased. We emphasize that respiratory dyskinesia should be differentiated from psychogenic hyperventilation as easily misdiagnosed on initial examination.

A simple method for determining the activity of large-area beta sources constructed from anodized aluminum foils

International Nuclear Information System (INIS)

Stanga, D.

2014-01-01

A simple method has been developed for determining the activity of large-area beta reference sources in anodized aluminum foils. It is based on the modeling of the transmission of beta rays through thin foils in planar geometry using Monte Carlo simulation. The method was checked experimentally and measurement results show that the activity of large-area beta reference sources in anodized aluminum foils can be measured with standard uncertainties smaller than the limit of 10% required by ISO 8769. - Highlights: • A method for determining the activity of large-area beta sources is presented. • The method is based on a model of electron transport in planar geometry. • The method makes use of linear programming for determining the activity. • The uncertainty of the method is smaller than 10%

L-malate enhances the gene expression of carried proteins and antioxidant enzymes in liver of aged rats.

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Zeng, X; Wu, J; Wu, Q; Zhang, J

2015-01-01

Previous studies in our laboratory reported L-malate as a free radical scavenger in aged rats. To investigate the antioxidant mechanism of L-malate in the mitochondria, we analyzed the change in gene expression of two malate-aspartate shuttle (MAS)-related carried proteins (AGC, aspartate/glutamate carrier and OMC, oxoglutarate/malate carrier) in the inner mitochondrial membrane, and three antioxidant enzymes (CAT, SOD, and GSH-Px) in the mitochondria. The changes in gene expression of these proteins and enzymes were examined by real-time RT-PCR in the heart and liver of aged rats treated with L-malate. L-malate was orally administered in rats continuously for 30 days using a feeding atraumatic needle. We found that the gene expression of OMC and GSH-Px mRNA in the liver increased by 39 % and 38 %, respectively, in the 0.630 g/kg L-malate treatment group than that in the control group. The expression levels of SOD mRNA in the liver increased by 39 %, 56 %, and 78 % in the 0.105, 0.210, and 0.630 g/kg L-malate treatment groups, respectively. No difference were observed in the expression levels of AGC, OMC, CAT, SOD, and GSH-Px mRNAs in the heart of rats between the L-malate treatment and control groups. These results predicted that L-malate may increase the antioxidant capacity of mitochondria by enhancing the expression of mRNAs involved in the MAS and the antioxidant enzymes.

GABA signalling modulates plant growth by directly regulating the activity of plant-specific anion transporters.

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Ramesh, Sunita A; Tyerman, Stephen D; Xu, Bo; Bose, Jayakumar; Kaur, Satwinder; Conn, Vanessa; Domingos, Patricia; Ullah, Sana; Wege, Stefanie; Shabala, Sergey; Feijó, José A; Ryan, Peter R; Gilliham, Matthew; Gillham, Matthew

2015-07-29

The non-protein amino acid, gamma-aminobutyric acid (GABA) rapidly accumulates in plant tissues in response to biotic and abiotic stress, and regulates plant growth. Until now it was not known whether GABA exerts its effects in plants through the regulation of carbon metabolism or via an unidentified signalling pathway. Here, we demonstrate that anion flux through plant aluminium-activated malate transporter (ALMT) proteins is activated by anions and negatively regulated by GABA. Site-directed mutagenesis of selected amino acids within ALMT proteins abolishes GABA efficacy but does not alter other transport properties. GABA modulation of ALMT activity results in altered root growth and altered root tolerance to alkaline pH, acid pH and aluminium ions. We propose that GABA exerts its multiple physiological effects in plants via ALMT, including the regulation of pollen tube and root growth, and that GABA can finally be considered a legitimate signalling molecule in both the plant and animal kingdoms.

Phosphorylation of glyoxysomal malate synthase from castor oil seed endosperm and cucumber cotyledon

International Nuclear Information System (INIS)

Yang, Y.P; Randall, D.D.

1989-01-01

Glyoxysomal malate synthase (MS) was purified to apparent homogeneity from 3-d germinating castor oil seed endosperm by a relatively simple procedure including two sucrose density gradient centrifugations. Antibodies raised to the caster oil seed MS crossreacted with MS from cucumber cotyledon. MS was phosphorylated in both tissues in an MgATP dependent reaction. The phosphorylation pattern was similar for both enzymes and both enzymes were inhibited by NaF, NaMo, (NH 4 )SO 4 , glyoxylate and high concentration of MgCl 2 (60 mM), but was not inhibited by NaCl and malate. Further characterization of the phosphorylation of MS from castor oil seed endosperms showed that the 5S form of MS is the form which is labelled by 32 P. The addition of exogenous alkaline phosphatase to MS not only decreased enzyme activity, but could also dephosphorylate phospho-MS. The relationship between dephosphorylation of MS and the decrease of MS activity is currently under investigation

Activated aluminum hydride hydrogen storage compositions and uses thereof

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Sandrock, Gary; Reilly, James; Graetz, Jason; Wegrzyn, James E.

2010-11-23

In one aspect, the invention relates to activated aluminum hydride hydrogen storage compositions containing aluminum hydride in the presence of, or absence of, hydrogen desorption stimulants. The invention particularly relates to such compositions having one or more hydrogen desorption stimulants selected from metal hydrides and metal aluminum hydrides. In another aspect, the invention relates to methods for generating hydrogen from such hydrogen storage compositions.

Enhanced active aluminum content and thermal behaviour of nano-aluminum particles passivated during synthesis using thermal plasma route

International Nuclear Information System (INIS)

Mathe, Vikas L.; Varma, Vijay; Raut, Suyog; Nandi, Amiya Kumar; Pant, Arti; Prasanth, Hima; Pandey, R.K.; Bhoraskar, Sudha V.; Das, Asoka K.

2016-01-01

Graphical abstract: - Highlights: • Synthesis of nano crystalline Al (nAl) using DC thermal plasma reactor. • In situ passivation of nAl by palmitic acid and air. • Enhanced active aluminum content obtained for palmitic acid passivated nAl. • Palmitic acid passivated nAl are quite stable in humid atmospheres. - Abstract: Here, we report synthesis and in situ passivation of aluminum nanoparticles using thermal plasma reactor. Both air and palmitc acid passivation was carried out during the synthesis in the thermal plasma reactor. The passivated nanoparticles have been characterized for their structural and morphological properties using X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. In order to understand nature of passivation vibrational spectroscopic analysis have been carried out. The enhancement in active aluminum content and shelf life for a palmitic acid passivated nano-aluminum particles in comparison to the air passivated samples and commercially available nano Al powder (ALEX) has been observed. Thermo-gravimetric analysis was used to estimate active aluminum content of all the samples under investigation. In addition cerimetric back titration method was also used to estimate AAC and the shelf life of passivated aluminum particles. Structural, microstructural and thermogravomateric analysis of four year aged passivated sample also depicts effectiveness of palmitic acid passivation.

Enhanced active aluminum content and thermal behaviour of nano-aluminum particles passivated during synthesis using thermal plasma route

Energy Technology Data Exchange (ETDEWEB)

Mathe, Vikas L., E-mail: vlmathe@physics.unipune.ac.in [Department of Physics, Savitribai Phule Pune University, Pune 411007, Maharashtra (India); Varma, Vijay; Raut, Suyog [Department of Physics, Savitribai Phule Pune University, Pune 411007, Maharashtra (India); Nandi, Amiya Kumar; Pant, Arti; Prasanth, Hima; Pandey, R.K. [High Energy Materials Research Lab, Sutarwadi, Pune 411021, Maharashtra (India); Bhoraskar, Sudha V. [Department of Physics, Savitribai Phule Pune University, Pune 411007, Maharashtra (India); Das, Asoka K. [Utkal University, VaniVihar, Bhubaneswar, Odisha 751004 (India)

2016-04-15

Graphical abstract: - Highlights: • Synthesis of nano crystalline Al (nAl) using DC thermal plasma reactor. • In situ passivation of nAl by palmitic acid and air. • Enhanced active aluminum content obtained for palmitic acid passivated nAl. • Palmitic acid passivated nAl are quite stable in humid atmospheres. - Abstract: Here, we report synthesis and in situ passivation of aluminum nanoparticles using thermal plasma reactor. Both air and palmitc acid passivation was carried out during the synthesis in the thermal plasma reactor. The passivated nanoparticles have been characterized for their structural and morphological properties using X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. In order to understand nature of passivation vibrational spectroscopic analysis have been carried out. The enhancement in active aluminum content and shelf life for a palmitic acid passivated nano-aluminum particles in comparison to the air passivated samples and commercially available nano Al powder (ALEX) has been observed. Thermo-gravimetric analysis was used to estimate active aluminum content of all the samples under investigation. In addition cerimetric back titration method was also used to estimate AAC and the shelf life of passivated aluminum particles. Structural, microstructural and thermogravomateric analysis of four year aged passivated sample also depicts effectiveness of palmitic acid passivation.

Effect of mechanical activation on structure and thermal decomposition of aluminum sulfate

International Nuclear Information System (INIS)

Ghasri-Khouzani, M.; Meratian, M.; Panjepour, M.

2009-01-01

The thermal decompositions of both non-activated and mechanically activated aluminum sulfates were studied by thermogravimetry (TG). The structural disorder, the specific surface area (SSA) and the morphology of mechanically activated aluminum sulfates were analyzed by X-ray diffraction (XRD), laser particle-size analyzer, and scanning electron microscopy (SEM), respectively. Thermal analyses results indicated that the initial temperature of thermal decomposition (T i ) in TG curves for mechanically activated aluminum sulfates decreased gradually with increasing the milling time. It was also found that the SSA of mechanically activated aluminum sulfates remained almost constant after a certain milling time, and lattice strains (ε) rose but the crystallite sizes (D) decreased with increasing the milling time. These results showed that the decrease of T i in TG curves of mechanically activated aluminum sulfates was mainly caused by the increase of lattice distortions and decrease of the crystallite sizes with increasing the milling time

Evaluation of 90-day Repeated Dose Oral Toxicity, Glycometabolism, Learning and Memory Ability, and Related Enzyme of Chromium Malate Supplementation in Sprague-Dawley Rats.

Science.gov (United States)

Feng, Weiwei; Wu, Huiyu; Li, Qian; Zhou, Zhaoxiang; Chen, Yao; Zhao, Ting; Feng, Yun; Mao, Guanghua; Li, Fang; Yang, Liuqing; Wu, Xiangyang

2015-11-01

Our previous study showed that chromium malate improved the regulation of blood glucose in mice with alloxan-induced diabetes. The present study was designed to evaluate the 90-day oral toxicity of chromium malate in Sprague-Dawley rats. The present study inspected the effect of chromium malate on glycometabolism, glycometabolism-related enzymes, lipid metabolism, and learning and memory ability in metabolically healthy Sprague-Dawley rats. The results showed that all rats survived and pathological, toxic, feces, and urine changes were not observed. Chromium malate did not cause measurable damage on liver, brain, and kidney. The fasting blood glucose, serum insulin, insulin resistance index, C-peptide, hepatic glycogen, glucose-6-phosphate dehydrogenase, glucokinase, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels of normal rats in chromium malate groups had no significant change when compared with control group and chromium picolinate group under physiologically relevant conditions. The serum and organ content of Cr in chromium malate groups had no significant change compared with control group. No significant changes were found in morris water maze test and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and true choline esterase (TChE) activity. The results indicated that supplementation with chromium malate did not cause measurable toxicity and has no obvious effect on glycometabolism and related enzymes, learning and memory ability, and related enzymes and lipid metabolism of female and male rats. The results of this study suggest that chromium malate is safe for human consumption.

Long noncoding RNA MALAT1 as a potential novel biomarker in digestive system cancers: a meta-analysis.

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Song, Wei; Zhang, Run J; Zou, Shu B

2016-08-01

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a newly discovered long non-coding RNA (lncRNA), has been reported to be overexpressed in various cancers. However, the clinical value of MALAT1 in digestive system cancers is unclear. This study was designed to investigate the potential value of MALAT1 as a prognostic biomarker in digestive system cancers. We searched the Medline, Embase and Cochrane Library databases. All studies that explored the correlation between lncRNA MALAT1 expression and survival in digestive system tumors were selected. A quantitative meta-analysis was performed for the correlation between lncRNA MALAT1 expression and survival in digestive system tumors. Five studies were eligible for analysis, which included 547 patients. Meta-analysis showed that high expression of MALAT1 could predict poor overall survival (OS) in digestive system cancers (pooled HR: 1.85, 95% CI: 1.41-2.43, Pdigestive system cancers.

The Association between Abnormal Long Noncoding RNA MALAT-1 Expression and Cancer Lymph Node Metastasis: A Meta-Analysis

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Jun Wang

2016-01-01

Full Text Available Previous studies have investigated that the expression levels of MALAT-1 were higher in cancerous tissues than matched histologically normal tissues. And, to some extent, overexpression of MALAT-1 was inclined to lymph node metastasis. This meta-analysis collected all relevant articles and explored the association between MALAT-1 expression levels and lymph node metastasis. We searched PubMed, EmBase, Web of Science, Cochrane Library, and OVID to address the level of MALAT-1 expression in cancer cases and noncancerous controls (accessed February 2015. And 8 studies comprising 696 multiple cancer patients were included to assess this association. The odds ratio (OR and its corresponding 95% confidence interval (CI were calculated to assess the strength of the association using Stata 12.0 version software. The results revealed there was a significant difference in the incidence of lymph node metastasis between high MALAT-1 expression group and low MALAT-1 expression group (OR = 1.94, 95% CI 1.15–3.28, P=0.013 random-effects model. Subgroup analysis indicated that MALAT-1 high expression had an unfavorable impact on lymph node metastasis in Chinese patients (OR = 1.87, 95% CI 1.01–2.46. This study demonstrated that the incidence of lymph node metastasis in patients detected with high MALAT-1 expression was higher than that in patients with low MALAT-1 expression in China.

Metabolic engineering of Aspergillus oryzae for efficient production of l-malate directly from corn starch.

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

2017-11-20

l-Malate, an important chemical building block, has been widely applied in the food, pharmaceutical, and bio-based materials industries. In previous work, we engineered Aspergillus oryzae by rewiring the reductive tricarboxylic acid pathway to produce l-malate from glucose. To decrease the production cost, here, we further engineered A. oryzae to efficiently produce l-malate directly from corn starch with simultaneous liquefaction-saccharification and fermentation. First, a promoter PN5 was constructed by quintuple tandem of the 97-bp fragment containing the cis-element of the glucoamylase gene promoter (PglaA), and with the promoter PN5, the transcriptional level of glaA gene increased by 25-45%. Then, by co-overexpression of glaA, a-amylase (amyB) and a-glucosidase (agdA) genes with the promoter PN5, the l-malate titer increased from 55.5g/L to 72.0g/L with 100g/L corn starch in shake flask. In addition, to reduce the concentration of byproducts succinate and fumarate, a fumarase from Saccharomyces cerevisiae, which facilitated the transformation of fumarate to l-malate, was overexpressed. As a result, the concentration of succinate and fumarate decreased from 12.6 and 1.29g/L to 7.8 and 0.59g/L, and the l-malate titer increased from 72.0g/L to 78.5g/L. Finally, we found that the addition of glucose at the initial fermentation stage facilitated the cell growth and l-malate synthesis, and the l-malate titer further increased to 82.3g/L by co-fermentation of 30g/L glucose and 70g/L corn starch, with a productivity of 1.18g/L/h and a yield of 0.82g/g total carbon sources. Copyright © 2017 Elsevier B.V. All rights reserved.

Utilization of Aluminum Waste with Hydrogen and Heat Generation

Science.gov (United States)

Buryakovskaya, O. A.; Meshkov, E. A.; Vlaskin, M. S.; Shkolnokov, E. I.; Zhuk, A. Z.

2017-10-01

A concept of energy generation via hydrogen and heat production from aluminum containing wastes is proposed. The hydrogen obtained by oxidation reaction between aluminum waste and aqueous solutions can be supplied to fuel cells and/or infrared heaters for electricity or heat generation in the region of waste recycling. The heat released during the reaction also can be effectively used. The proposed method of aluminum waste recycling may represent a promising and cost-effective solution in cases when waste transportation to recycling plants involves significant financial losses (e.g. remote areas). Experiments with mechanically dispersed aluminum cans demonstrated that the reaction rate in alkaline solution is high enough for practical use of the oxidation process. In theexperiments aluminum oxidation proceeds without any additional aluminum activation.

Dispersive electron transport in tris(8-hydroxyquinoline) aluminum (Alq3) probed by impedance spectroscopy.

Science.gov (United States)

Berleb, Stefan; Brütting, Wolfgang

2002-12-31

Electron transport in tris(8-hydroxyquinoline) aluminum (Alq3) is investigated by impedance spectroscopy under conditions of space-charge limited conduction (SCLC). Existing SCLC models are extended to include the field dependence of the charge carrier mobility and energetically distributed trap states. The dispersive nature of electron transport is revealed by a frequency-dependent mobility with a dispersion parameter alpha in the range 0.4-0.5, independent of temperature. This indicates that positional rather than energetic disorder is the dominant mechanism for the dispersive transport of electrons in Alq3.

FUNCTIONAL-ANALYSIS OF THE N-TERMINAL PREPEPTIDES OF WATERMELON MITOCHONDRIAL AND GLYOXYSOMAL MALATE-DEHYDROGENASES

NARCIS (Netherlands)

LEHNERER, M; KEIZERGUNNIK, [No Value; VEENHUIS, M; GIETL, C

1994-01-01

Mitochondrial and glyoxysomal malate dehydrogenase (mMDH; gMDH; L-malate : NAD(+) oxidoreductase; EC 1.1.1.37) of watermelon (Citrullus vulgaris) cotyledons are synthesized with N-terminal cleavable presequences which are shown to specify sorting of the two proteins. The two presequences differ in

Primary structure of the light-dependent regulatory site of corn NADP-malate dehydrogenase

Energy Technology Data Exchange (ETDEWEB)

Decottignies, P.; Schmitter, J.M.; Miginiac-Maslow, M.; Le Marechal, P.; Jacquot, J.P.; Gadal, P.

1988-08-25

The light-activated NADP-malate dehydrogenase (NADP-MDH) catalyzes the reduction of oxaloacetate to malate in higher plant chloroplasts. This enzyme is regulated in vivo by the ferredoxin-thioredoxin system through redox reactions. NADP-MDH has been photoactivated in vitro in a chloroplast system reconstituted from the pure protein components and thylakoid membranes. Photoactivation was accompanied by the appearance of new thiol groups (followed by (14C)iodoacetate incorporation). 14C-Carboxymethylated NADP-MDH has been purified from the incubation mixture and its amino-terminal sequence analyzed. Two (14C)carboxymethylcysteines were identified at positions 10 and 15 after light activation, while they were not detected in the dark-treated protein. In addition, the analysis of the tryptic digest of light-activated (14C)carboxymethylated NADP-MDH revealed that the radioactive label was mostly incorporated in Cys10 and Cys15, indicating that these 2 residues play a major role in the light activation mechanism. Moreover, an activation model, in which photoreduced thio-redoxin was replaced by the dithiol reductant dithio-threitol, has been developed. When NADP-MDH was activated in this way, the same sulfhydryls were found to be labeled, and alternatively, they did not incorporate any radioactivity when dithiothreitol reduction was performed after carboxymethylation in denaturating conditions. These results indicate that activation (by light or by dithiothreitol) proceeds on each subunit by reduction of a disulfide bridge located at the amino terminus of the enzyme between Cys10 and Cys15.

Primary structure of the light-dependent regulatory site of corn NADP-malate dehydrogenase

International Nuclear Information System (INIS)

Decottignies, P.; Schmitter, J.M.; Miginiac-Maslow, M.; Le Marechal, P.; Jacquot, J.P.; Gadal, P.

1988-01-01

The light-activated NADP-malate dehydrogenase (NADP-MDH) catalyzes the reduction of oxaloacetate to malate in higher plant chloroplasts. This enzyme is regulated in vivo by the ferredoxin-thioredoxin system through redox reactions. NADP-MDH has been photoactivated in vitro in a chloroplast system reconstituted from the pure protein components and thylakoid membranes. Photoactivation was accompanied by the appearance of new thiol groups (followed by [14C]iodoacetate incorporation). 14C-Carboxymethylated NADP-MDH has been purified from the incubation mixture and its amino-terminal sequence analyzed. Two [14C]carboxymethylcysteines were identified at positions 10 and 15 after light activation, while they were not detected in the dark-treated protein. In addition, the analysis of the tryptic digest of light-activated [14C]carboxymethylated NADP-MDH revealed that the radioactive label was mostly incorporated in Cys10 and Cys15, indicating that these 2 residues play a major role in the light activation mechanism. Moreover, an activation model, in which photoreduced thio-redoxin was replaced by the dithiol reductant dithio-threitol, has been developed. When NADP-MDH was activated in this way, the same sulfhydryls were found to be labeled, and alternatively, they did not incorporate any radioactivity when dithiothreitol reduction was performed after carboxymethylation in denaturating conditions. These results indicate that activation (by light or by dithiothreitol) proceeds on each subunit by reduction of a disulfide bridge located at the amino terminus of the enzyme between Cys10 and Cys15

Action of sulphite on plant malate dehydrogenase

Energy Technology Data Exchange (ETDEWEB)

Ziegler, I.

1974-01-01

SO/sub 3//sup 2 -/ acts on NAD- and NADP-dependent malate dehydrogenase in several ways. Firstly, SO/sub 3//sup 2 -/ favours the appearance of low MW species (65000 and 39000 daltons) in Sephadex gel chromatography. Secondly, the enzyme from which is obtained by gel chromatography with dithioerythritol plus nucleotide cofactor is changed in the presence of SO/sub 3//sup 2 -/. This is indicated by the appearance of a linear reaction (instead of curvilinear), and by the abolition of the biphasic sigmoidal kinetics on varying substrate and cofactor concentrations. Thus the inhibition of initial velocity at high substrate or cofactor concentrations is even more marked than at lower ones. Thirdly, SO/sub 3//sup 2 -/ strongly reduces the activity in substrate saturating conditions.

la phosphoglucoisomerase et la malate deshydrogenase

African Journals Online (AJOL)

AISA

dimérique du cycle de Krebs qui catalyse la réaction suivante: Malate + NAD MDH Oxaloacétate +. NADH. Dans les cellules du maïs, les formes cytosoliques sont codées par deux loci, les formes mitochondriales par 3 loci (Newton et. Schwartz, 1980). L'acide ascorbique inhibe préférentiellement les formes du cytosol.

The long non-coding RNA MALAT1 promotes the migration and invasion of hepatocellular carcinoma by sponging miR-204 and releasing SIRT1.

Science.gov (United States)

Hou, Zhouhua; Xu, Xuwen; Zhou, Ledu; Fu, Xiaoyu; Tao, Shuhui; Zhou, Jiebin; Tan, Deming; Liu, Shuiping

2017-07-01

Increasing evidence supports the significance of long non-coding RNA in cancer development. Several recent studies suggest the oncogenic activity of long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in hepatocellular carcinoma. In this study, we explored the molecular mechanisms by which MALAT1 modulates hepatocellular carcinoma biological behaviors. We found that microRNA-204 was significantly downregulated in sh-MALAT1 HepG2 cell and 15 hepatocellular carcinoma tissues by quantitative real-time polymerase chain reaction analysis. Through bioinformatic screening, luciferase reporter assay, RNA-binding protein immunoprecipitation, and RNA pull-down assay, we identified microRNA-204 as a potential interacting partner for MALAT1. Functionally, wound-healing and transwell assays revealed that microRNA-204 significantly inhibited the migration and invasion of hepatocellular carcinoma cells. Notably, sirtuin 1 was recognized as a direct downstream target of microRNA-204 in HepG2 cells. Moreover, si-SIRT1 significantly inhibited cell invasion and migration process. These data elucidated, by sponging and competitive binding to microRNA-204, MALAT1 releases the suppression on sirtuin 1, which in turn promotes hepatocellular carcinoma migration and invasion. This study reveals a novel mechanism by which MALAT1 stimulates hepatocellular carcinoma progression and justifies targeting metastasis-associated lung adenocarcinoma transcript 1 as a potential therapy for hepatocellular carcinoma.

Long Non-Coding RNA Malat-1 Is Dispensable during Pressure Overload-Induced Cardiac Remodeling and Failure in Mice.

Directory of Open Access Journals (Sweden)

Tim Peters

Full Text Available Long non-coding RNAs (lncRNAs are a class of RNA molecules with diverse regulatory functions during embryonic development, normal life, and disease in higher organisms. However, research on the role of lncRNAs in cardiovascular diseases and in particular heart failure is still in its infancy. The exceptionally well conserved nuclear lncRNA Metastasis associated in lung adenocarcinoma transcript 1 (Malat-1 is a regulator of mRNA splicing and highly expressed in the heart. Malat-1 modulates hypoxia-induced vessel growth, activates ERK/MAPK signaling, and scavenges the anti-hypertrophic microRNA-133. We therefore hypothesized that Malat-1 may act as regulator of cardiac hypertrophy and failure during cardiac pressure overload induced by thoracic aortic constriction (TAC in mice.Absence of Malat-1 did not affect cardiac hypertrophy upon pressure overload: Heart weight to tibia length ratio significantly increased in WT mice (sham: 5.78±0.55, TAC 9.79±1.82 g/mm; p<0.001 but to a similar extend also in Malat-1 knockout (KO mice (sham: 6.21±1.12, TAC 8.91±1.74 g/mm; p<0.01 with no significant difference between genotypes. As expected, TAC significantly reduced left ventricular fractional shortening in WT (sham: 38.81±6.53%, TAC: 23.14±11.99%; p<0.01 but to a comparable degree also in KO mice (sham: 37.01±4.19%, TAC: 25.98±9.75%; p<0.05. Histological hallmarks of myocardial remodeling, such as cardiomyocyte hypertrophy, increased interstitial fibrosis, reduced capillary density, and immune cell infiltration, did not differ significantly between WT and KO mice after TAC. In line, the absence of Malat-1 did not significantly affect angiotensin II-induced cardiac hypertrophy, dysfunction, and overall remodeling. Above that, pressure overload by TAC significantly induced mRNA levels of the hypertrophy marker genes Nppa, Nppb and Acta1, to a similar extend in both genotypes. Alternative splicing of Ndrg2 after TAC was apparent in WT (isoform ratio

Pengaruh Pengasapan (Thermal Fogging Insektisida Piretroid (Malation 95% Terhadap Nyamuk Aedes aegypti dan Culex quinquefasciatus di Pemukiman

Directory of Open Access Journals (Sweden)

Hasan Boesri

2013-02-01

Full Text Available Abstracts. The evaluation of piretroid insecticide (active ingredient Malation 95% was con­ducted in Sub district Tengarang, Semarang Segency, Central Java Province. The insecti­cide was applied using thermal fogging method for dosages of 125, 250, 375, 500 and 625 ml/ha (diluted in diesel to 10 litters. The evaluation of the efficacy was conducted against two mosquito species, Aedes aegypti (the main dengue haemorrhagic fever and Culex quinquefasciatus (the urban lymphatic fil­ariasis vector. Result of the evaluation was revealed that dosages of 500 and 625 ml/ha were effective against both tested mosquito species indoor and outdoor.Key Word: Aedes aegypti, Culex quinquefasciatus, insecticide Piretroid (Malation 95%, thermal fogging.

Mechanism of Corrosion of Activated Aluminum Particles by Hot Water

International Nuclear Information System (INIS)

Razavi-Tousi, S.S.; Szpunar, J.A.

2014-01-01

Mechanism of corrosion in aluminum particles by hot water treatment for hydrogen generation is evaluated. The aluminum powder was activated by ball milling for different durations, which modified size and microstructure of the particles. Open circuit potential test was carried out to elucidate different stages of the reaction. Tafel test was used to explain the effect of ball milling and growth of hydroxide layer on corrosion of the particles. Surface, cross section and thickness of the grown hydroxide on the aluminum particles were studied in a scanning electron microscope. The corrosion potential of the aluminum powders depends on microstructure of the aluminum particles, growth of the hydroxide layer and a change in pH because of cathodic reactions. The hydrogen production test showed that a deformed microstructure and smaller particle size accelerates the corrosion rate of aluminum by hot water, the effect of the deformed microstructure being more significant at the beginning of the reaction. Effect of growth of the hydroxide layer on corrosion mechanism is discussed

Quininium Malates: Partial Chiral Discrimination via Diastereomeric ...

African Journals Online (AJOL)

Quinine was employed as a resolving agent for racemic malic acid. The resultant product was a quininium salt containing 75 % of the D-malate anion. Quinine was also crystallized with pure L- and D-malic acids and the structures of the resulting diastereomeric salts were elucidated. The crystal packings were analyzed in ...

Prognostic value of long noncoding RNA MALAT1 in digestive system malignancies.

Science.gov (United States)

Zhai, Hui; Li, Xiao-Mei; Maimaiti, Ailifeire; Chen, Qing-Jie; Liao, Wu; Lai, Hong-Mei; Liu, Fen; Yang, Yi-Ning

2015-01-01

MALAT1, a newly discovered long noncoding RNA (lncRNA), has been reported to be highly expressed in many types of cancers. This meta-analysis summarizes its potential prognostic value in digestive system malignancies. A quantitative meta-analysis was performed through a systematic search in PubMed, Cochrane Library, Web of Science and Chinese National Knowledge Infrastructure (CNKI) for eligible papers on the prognostic impact of MALAT1 in digestive system malignancies from inception to Apr. 25, 2015. Pooled hazard ratios (HRs) with 95% confidence interval (95% CI) were calculated to summarize the effect. Five studies were included in the study, with a total of 527 patients. A significant association was observed between MALAT1 abundance and poor overall survival (OS) of patients with digestive system malignancies, with pooled hazard ratio (HR) of 7.68 (95% confidence interval [CI]: 4.32-13.66, Pdigestive system malignancies.

In Vitro Analysis of Metabolite Transport Proteins.

Science.gov (United States)

Roell, Marc-Sven; Kuhnert, Franziska; Zamani-Nour, Shirin; Weber, Andreas P M

2017-01-01

The photorespiratory cycle is distributed over four cellular compartments, the chloroplast, peroxisomes, cytoplasm, and mitochondria. Shuttling of photorespiratory intermediates between these compartments is essential to maintain the function of photorespiration. Specific transport proteins mediate the transport across biological membranes and represent important components of the cellular metabolism. Although significant progress was made in the last years on identifying and characterizing new transport proteins, the overall picture of intracellular metabolite transporters is still rather incomplete. The photorespiratory cycle requires at least 25 transmembrane transport steps; however to date only plastidic glycolate/glycerate transporter and the accessory 2-oxoglutarate/malate and glutamate/malate transporters as well as the mitochondrial transporter BOU1 have been identified. The characterization of transport proteins and defining their substrates and kinetics are still major challenges.Here we present a detailed set of protocols for the in vitro characterization of transport proteins. We provide protocols for the isolation of recombinant transport protein expressed in E. coli or Saccharomyces cerevisiae and the extraction of total leaf membrane protein for in vitro analysis of transporter proteins. Further we explain the process of reconstituting transport proteins in artificial lipid vesicles and elucidate the details of transport assays.

Enzymatic urea adaptation: lactate and malate dehydrogenase in elasmobranchs

Czech Academy of Sciences Publication Activity Database

Lagana, G.; Bellocco, E.; Mannucci, C.; Leuzzi, U.; Tellone, E.; Kotyk, Arnošt; Galtieri, A.

2006-01-01

Roč. 55, č. 6 (2006), s. 675-688 ISSN 0862-8408 Institutional research plan: CEZ:AV0Z50110509 Keywords : elasmobranchs * lactate dehydrogenase * malate dehydrogenase Subject RIV: CE - Biochemistry Impact factor: 2.093, year: 2006

Development of antimigraine transdermal delivery systems of pizotifen malate.

Science.gov (United States)

Serna-Jiménez, C E; del Rio-Sancho, S; Calatayud-Pascual, M A; Balaguer-Fernández, C; Femenía-Font, A; López-Castellano, A; Merino, V

2015-08-15

The aim of this study was to develop and evaluate a transdermal delivery system of pizotifen malate. Pizotifen is frequently used in the preventive treatment of migraine, but is also indicated in eating disorders. In the course of the project, the effects of chemical enhancers such as ethanol, 1,8-cineole, limonene, azone and different fatty acids (decanoic, decenoic, dodecanoic, linoleic and oleic acids) were determined, first using a pizotifen solution. Steady state flux, diffusion and partition parameters were estimated by fitting the Scheuplein equation to the data obtained. Among the chemical enhancers studied, decenoic acid showed the highest enhancement activity, which seemed to be due to the length of its alkyl chain and unsaturation at the 9th carbon. The influence of iontophoresis and the involvement of electrotransport in said process was determined. The absorption profile obtained with iontophoresis was similar to that obtained with fatty acids and terpenes, though skin deposition of the drug was lower with the former. Transdermal delivery systems (TDS) of pizotifen were manufactured by including chemical enhancers, decenoic acid or oleic acid, and were subsequently characterized. When the results obtained with solutions were compared with those obtained with the TDS, a positive enhancement effect was observed with the latter with respect to the partitioning and diffusion of the drug across the skin. Our findings endorse the suitability of our TDS for delivering therapeutic amounts of pizotifen malate. Copyright © 2015 Elsevier B.V. All rights reserved.

The lncRNA Malat1 Is Dispensable for Mouse Development but Its Transcription Plays a cis-Regulatory Role in the Adult

Directory of Open Access Journals (Sweden)

Bin Zhang

2012-07-01

Full Text Available Genome-wide studies have identified thousands of long noncoding RNAs (lncRNAs lacking protein-coding capacity. However, most lncRNAs are expressed at a very low level, and in most cases there is no genetic evidence to support their in vivo function. Malat1 (metastasis associated lung adenocarcinoma transcript 1 is among the most abundant and highly conserved lncRNAs, and it exhibits an uncommon 3′-end processing mechanism. In addition, its specific nuclear localization, developmental regulation, and dysregulation in cancer are suggestive of it having a critical biological function. We have characterized a Malat1 loss-of-function genetic model that indicates that Malat1 is not essential for mouse pre- and postnatal development. Furthermore, depletion of Malat1 does not affect global gene expression, splicing factor level and phosphorylation status, or alternative pre-mRNA splicing. However, among a small number of genes that were dysregulated in adult Malat1 knockout mice, many were Malat1 neighboring genes, thus indicating a potential cis-regulatory role of Malat1 gene transcription.

Decarboxylation of Malate in the Crassulacean Acid Metabolism Plant Bryophyllum (Kalanchoe) fedtschenkoi (Role of NAD-Malic Enzyme).

Science.gov (United States)

Cook, R. M.; Lindsay, J. G.; Wilkins, M. B.; Nimmo, H. G.

1995-01-01

The role of NAD-malic enzyme (NAD-ME) in the Crassulacean acid metabolism plant Bryophyllum (Kalanchoe) fedtschenkoi was investigated using preparations of intact and solubilized mitochondria from fully expanded leaves. Intact, coupled mitochondria isolated during the day or night did not differ in their ability to take up [14C]malic acid from the surrounding medium or to respire using malate or succinate as substrate. However, intact mitochondria isolated from plants during the day decarboxylated added malate to pyruvate significantly faster than mitochondria isolated from plants at night. NAD-ME activity in solubilized mitochondrial extracts showed hysteretic kinetics and was stimulated by a number of activators, including acetyl-coenzyme A, fructose-1,6-bisphosphate, and sulfate ions. In the absence of these effectors, reaction progress curves were nonlinear, with a pronounced acceleration phase. The lag period before a steady-state rate was reached in assays of mitochondrial extracts decreased during the photoperiod and increased slowly during the period of darkness. However, these changes in the kinetic properties of the enzyme could not account for the changes in the rate of decarboxylation of malate by intact mitochondria. Gel-filtration experiments showed that mitochondrial extracts contained three forms of NAD-ME with different molecular weights. The relative proportions of the three forms varied somewhat throughout the light/dark cycle, but this did not account for the changes in the kinetics behavior of the enzyme during the diurnal cycle. PMID:12228671

Fumarate to Malate Conversion in Infarcted Porcine Heart – a Pilot Study

DEFF Research Database (Denmark)

Søvsø Szocska Hansen, Esben; Tougaard, Rasmus Stilling; Nielsen, Per Mose

2017-01-01

Hyperpolarized MR may be a key tool for investigation cardiac metabolism and cardiac treatment response. [1,4- 13C2]Fumarate is an emerging and interesting candidate for measuring and visualizing cardiac injury after ischemia. In this study we showed an initial step for imaging cardiac cell death...... in a large animal model with [1,4- 13C2]malate. The [1,4- 13C2]malate signal correlated well with increased 13C-lactate signal and 13C-alanine absence. Overall, this shows increased metabolism in the infarcted area and ongoing necrosis....

Overexpression of BdMATE Gene Improves Aluminum Tolerance in Setaria viridis

Directory of Open Access Journals (Sweden)

Ana P. Ribeiro

2017-06-01

Full Text Available Acidic soils are distributed worldwide, predominantly in tropical and subtropical areas, reaching around 50% of the arable soil. This type of soil strongly reduces crop production, mainly because of the presence of aluminum, which has its solubility increased at low pH levels. A well-known physiological mechanism used by plants to cope with Al stress involves activation of membrane transporters responsible for organic acid anions secretion from the root apex to the rhizosphere, which chelate Al, preventing its absorption by roots. In sorghum, a membrane transporter gene belonging to multidrug and toxic compound extrusion (MATE family was identified and characterized as an aluminum-activated citrate transporter gene responsible for Al tolerance in this crop. Setaria viridis is an emerging model for C4 species and it is an important model to validate some genes for further C4 crops transformation, such as sugarcane, maize, and wheat. In the present work, Setaria viridis was used as a model plant to overexpress a newly identified MATE gene from Brachypodium distachyon (BdMATE, closely related to SbMATE, for aluminum tolerance assays. Transgenic S. viridis plants overexpressing a BdMATE presented an improved Al tolerance phenotype, characterized by sustained root growth and exclusion of aluminum from the root apex in transgenic plants, as confirmed by hematoxylin assay. In addition, transgenic plants showed higher root citrate exudation into the rhizosphere, suggesting that Al tolerance improvement in these plants could be related to the chelation of the metal by the organic acid anion. These results suggest that BdMATE gene can be used to transform C4 crops of economic importance with improved aluminum tolerance.

Estimation of aluminum and argon activation sources in the HANARO coolant

International Nuclear Information System (INIS)

Jun, Byung Jin; Lee, Byung Chul; Kim, Myong Seop

2010-01-01

The activation products of aluminum and argon are key radionuclides for operational and environmental radiological safety during the normal operation of open-tank-in-pool type research reactors using aluminum-clad fuels. Their activities measured in the primary coolant and pool surface water of HANARO have been consistent. We estimated their sources from the measured activities and then compared these values with their production rates obtained by a core calculation. For each aluminum activation product, an equivalent aluminum thickness (EAT) in which its production rate is identical to its release rate into the coolant is determined. For the argon activation calculation, the saturated argon concentration in the water at the temperature of the pool surface is assumed. The EATs are 5680, 266 and 1.2 nm, respectively, for Na-24, Mg-27 and Al-28, which are much larger than the flight lengths of the respective recoil nuclides. These values coincide with the water solubility levels and with the half-lives. The EAT for Na-24 is similar to the average oxide layer thickness (OLT) of fuel cladding as well; hence, the majority of them in the oxide layer may be released to the coolant. However, while the average OLT clearly increases with the fuel burn-up during an operation cycle, its effect on the pool-top radiation is not distinguishable. The source of Ar-41 is in good agreement with the calculated reaction rate of Ar-40 dissolved in the coolant

Enhancement of malate-production and increase in sensitivity to dimethyl succinate by mutation of the VID24 gene in Saccharomyces cerevisiae.

Science.gov (United States)

Negoro, Hiroaki; Kotaka, Atsushi; Matsumura, Kengo; Tsutsumi, Hiroko; Hata, Yoji

2016-06-01

Malate in sake (a Japanese alcoholic beverage) is an important component for taste that is produced by yeasts during alcoholic fermentation. To date, many researchers have developed methods for breeding high-malate-producing yeasts; however, genes responsible for the high-acidity phenotype are not known. We determined the mutated gene involved in high malate production in yeast, isolated as a sensitive mutant to dimethyl succinate. In the comparative whole genome analysis between high-malate-producing strain and its parent strain, one of the non-synonymous substitutions was identified in the VID24 gene. The mutation of VID24 resulted in enhancement of malate-productivity and sensitivity to dimethyl succinate. The mutation appeared to lead to a deficiency in Vid24p function. Furthermore, disruption of cytoplasmic malate dehydrogenase (Mdh2p) gene in the VID24 mutant inhibited the high-malate-producing phenotype. Vid24p is known as a component of the multisubunit ubiquitin ligase and participates in the degradation of gluconeogenic enzymes such as Mdh2p. We suggest that the enhancement of malate-productivity results from an accumulation of Mdh2p due to the loss of Vid24p function. These findings propose a novel mechanism for the regulation of organic acid production in yeast cells by the component of ubiquitin ligase, Vid24p. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Aberrant KDM5B expression promotes aggressive breast cancer through MALAT1 overexpression and downregulation of hsa-miR-448

International Nuclear Information System (INIS)

Bamodu, Oluwaseun Adebayo; Huang, Wen-Chien; Lee, Wei-Hwa; Wu, Alexander; Wang, Liang Shun; Hsiao, Michael; Yeh, Chi-Tai; Chao, Tsu-Yi

2016-01-01

Triple negative breast cancers (TNBC) possess cell dedifferentiation characteristics, carry out activities connate to those of cancer stem cells (CSCs) and are associated with increased metastasis, as well as, poor clinical prognosis. The regulatory mechanism of this highly malignant phenotype is still poorly characterized. Accruing evidence support the role of non-coding RNAs (ncRNAs) as potent regulators of CSC and metastatic gene expression, with their dysregulation implicated in tumorigenesis and disease progression. In this study, we investigated TNBC metastasis, metastasis-associated genes and potential inhibitory mechanisms using bioinformatics, tissue microarray analyses, immunoblotting, polymerase chain reaction, loss and gain of gene function assays and comparative analyses of data obtained. Compared with other breast cancer types, the highly metastatic MDA-MB-231 cells concurrently exhibited increased expression levels of Lysine-specific demethylase 5B protein (KDM5B) and long non-coding RNA (lncRNA), MALAT1, suggesting their functional association. KDM5B-silencing in the TNBC cells correlated with the upregulation of hsa-miR-448 and led to suppression of MALAT1 expression with decreased migration, invasion and clonogenic capacity in vitro, as well as, poor survival in vivo. This projects MALAT1 as a mediator of KDM5B oncogenic potential and highlights the critical role of this microRNA, lncRNA and histone demethylase in cancer cell motility and metastatic colonization. Increased expression of KDM5B correlating with disease progression and poor clinical outcome in breast cancer was reversed by hsa-miR-448. Our findings demonstrate the critical role of KDM5B and its negative regulator hsa-miR-448 in TNBC metastasis and progression. Hsa-miR-448 disrupting KDM5B-MALAT1 signalling axis and associated activities in TNBC cells, projects it as a putative therapeutic factor for selective eradication of TNBC cells

microRNA-9 targets the long non-coding RNA MALAT1 for degradation in the nucleus

DEFF Research Database (Denmark)

Leucci, Eleonora; Patella, Francesca; Waage, Johannes

2013-01-01

-coding RNAs. Here we report that microRNA-9 (miR-9) regulates the expression of the Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT-1), one of the most abundant and conserved long non-coding RNAs. Intriguingly, we find that miR-9 targets AGO2-mediated regulation of MALAT1 in the nucleus. Our...

Systemic Sunitinib Malate Treatment for Advanced Juxtapapillary Retinal Hemangioblastomas Associated with von Hippel-Lindau Disease.

Science.gov (United States)

Knickelbein, Jared E; Jacobs-El, Naima; Wong, Wai T; Wiley, Henry E; Cukras, Catherine A; Meyerle, Catherine B; Chew, Emily Y

2017-01-01

To describe the clinical course of advanced juxtapapillary retinal capillary hemangioblastomas (RCH) associated with von Hippel-Lindau (VHL) disease treated with systemic sunitinib malate, an agent that inhibits both anti-vascular endothelial growth factor and anti-platelet-derived growth factor signaling. Observational case review. Three patients with advanced VHL-related juxtapapillary RCH treated with systemic sunitinib malate. Patient 1 was followed routinely every 4 months while on systemic sunitinib prescribed by her oncologist for metastatic pancreatic neuroendocrine and kidney tumors. Patients 2 and 3 were part of a prospective clinical trial evaluating the use of systemic sunitinib for ocular VHL lesions during a period of 9 months. Visual acuity, size of RCH, and degree of exudation were recorded at each visit. Optical coherence tomography (OCT) and fluorescein angiography were also obtained at some visits. Visual acuity, size of RCH, and degree of exudation. Three patients with advanced VHL-associated juxtapapillary RCH were treated with systemic sunitinib malate. While none of the patients lost vision during therapy, treatment with sunitinib malate did not improve visual acuity or reduce the size of RCH. Improvements in RCH-associated retinal edema were observed in two patients. All patients experienced multiple adverse effects, including thyroid toxicity, thrombocytopenia, nausea, fatigue, jaundice, and muscle aches. Two of the three patients had to discontinue treatment prematurely and the third required dose reduction. Systemic sunitinib malate may be useful in slowing progression of ocular disease from VHL-associated RCH. However, significant systemic adverse effects limited its use in this small series, and systemic sunitinib malate may not be safe for treatment of RCH when used at the doses described in this report. Further studies are required to determine if this medication used at lower doses with different treatment strategies, other

49 CFR 178.505 - Standards for aluminum drums.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for aluminum drums. 178.505 Section 178... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.505 Standards for aluminum drums. (a) The following are the identification codes for aluminum drums: (1) 1B1 for a non-removable head aluminum drum...

Preliminary Report: Bases for Containment Analysis for Transportation of Aluminum-Based Spent Nuclear Fuel

International Nuclear Information System (INIS)

Vinson, D.W.

1998-01-01

Aluminum-based spent nuclear fuel (Al-SNF) from foreign and domestic research reactors (FRR/DRR) is being shipped to SRS under the site FRR/DRR Receipts Program. Shipment of the FRR/DRR assemblies required that the cask with loaded fuel be certified by the US Nuclear Regulatory Commission (for US-owned casks) or the US Department of Transportation (for foreign-owned casks) to comply with the requirements in 10CFR71

Tolerance of physic nut plants to aluminum activity in nutrient solution

OpenAIRE

Lana, Maria do Carmo; Steiner, Fábio [UNESP; Zoz, Tiago [UNESP; Fey, Rubens; Frandoloso, Jucenei Fernando

2013-01-01

Plants have different levels of tolerance to phytotoxic effects of aluminum and the exploitation of this characteristic is of significant importance to the use of acid soils. This research aimed to evaluate the effect of aluminum activity in nutrient solution on growth of physic nut young plant. After seven days of adaptation, plants were submitted to Al concentrations of 0; 200; 400; 600; 800 and 1,000 μmol L-1, corresponding to Al3+ activity solution, of: 14.5, 21.4; 46.6; 75.6; 108.3 e 144...

Identification of genes and pathways associated with aluminum stress and tolerance using transcriptome profiling of wheat near-isogenic lines.

Science.gov (United States)

Houde, Mario; Diallo, Amadou Oury

2008-08-27

Aluminum is considered the most limiting factor for plant productivity in acidic soils, which cover large areas of the world's potential arable lands. The inhibition of root growth is recognized as the primary effect of Al toxicity. To identify genes associated with Al stress and tolerance, transcriptome analyses of four different wheat lines (2 Al-tolerant and 2 Al sensitive) that differ in their response to Al were performed. Microarray expression profiling revealed that 83 candidate genes are associated with Al stress and 25 are associated with tolerance. The stress-associated genes include important enzymes such as pyruvate dehydrogenase, alternative oxidase, and galactonolactone oxidase, ABC transporter and ascorbate oxido-reducatase. The Al tolerance-associated genes include the ALMT-1 malate transporter, glutathione S-transferase, germin/oxalate oxidase, fructose 1,6-bisphosphatase, cysteine-rich proteins, cytochrome P450 monooxygenase, cellulose synthase, zinc finger transcription factor, disease resistance response protein and F-box containing domain protein. In this survey, we identified stress- and tolerance-associated genes that may be involved in the detoxification of Al and reactive oxygen species. Alternative pathways could help maintain the supply of important metabolites (H2O2, ascorbate, NADH, and phosphate) needed for Al tolerance and root growth. The Al tolerance-associated genes may be key factors that regulate these pathways.

Evidence for catabolite degradation in the glucose-dependent inactivation of yeast cytoplasmic malate dehydrogenase

International Nuclear Information System (INIS)

Neeff, J.; Haegele, E.; Nauhaus, J.; Heer, U.; Mecke, D.

1978-01-01

The cytoplasmic malate dehydrogenase of Saccharomyces cerevisiae was radioactively labeled during its synthesis on a glucose-free derepression medium. After purification a sensitive radioimmunoassay for this enzyme could be developed. The assay showed that after the physiological, glucose-dependent 'catabolite inactivation' of cytoplasmic malate dehydrogenase an inactive enzyme protein is immunologically not detectable. Together with the irreversibility of this reaction in vivo this finding strongly suggests a proteolytic mechanism of enzyme inactivation. For this process the term 'catabolite degradation' is used. (orig.) [de

Wheat genotypes differing in aluminum tolerance differ in their growth response to CO2 enrichment in acid soils

OpenAIRE

Tian, Qiuying; Zhang, Xinxin; Gao, Yan; Bai, Wenming; Ge, Feng; Ma, Yibing; Zhang, Wen-Hao

2013-01-01

Aluminum (Al) toxicity is a major factor limiting plant growth in acid soils. Elevated atmospheric CO2 [CO2] enhances plant growth. However, there is no report on the effect of elevated [CO2] on growth of plant genotypes differing in Al tolerance grown in acid soils. We investigated the effect of short-term elevated [CO2] on growth of Al-tolerant (ET8) and Al-sensitive (ES8) wheat plants and malate exudation from root apices by growing them in acid soils under ambient [CO2] and elevated [CO2]...

Permeabilization and lysis of Pseudomonas pseudoalcaligenes cells by triton X-100 for efficient production of D-malate

NARCIS (Netherlands)

Werf, M.J. van der; Hartmans, S.; Tweel, W.J.J. van den

1995-01-01

Pseudomonas pseudoalcaligenes can only form d-malate from maleate after incubation of the cells with a solvent or a detergent. The effect of the detergent Triton X-100 on d-malate production was studied in more detail. The longer the cells were incubated with Triton X-100, the higher was the

D-malate production by permeabilized Pseudomonas pseudoalcaligenes; optimization of conversion and biocatalyst productivity.

Science.gov (United States)

Michielsen, M J; Frielink, C; Wijffels, R H; Tramper, J; Beeftink, H H

2000-04-14

For the development of a continuous process for the production of solid D-malate from a Ca-maleate suspension by permeabilized Pseudomonas pseudoalcaligenes, it is important to understand the effect of appropriate process parameters on the stability and activity of the biocatalyst. Previously, we quantified the effect of product (D-malate2 -) concentration on both the first-order biocatalyst inactivation rate and on the biocatalytic conversion rate. The effects of the remaining process parameters (ionic strength, and substrate and Ca2 + concentration) on biocatalyst activity are reported here. At (common) ionic strengths below 2 M, biocatalyst activity was unaffected. At high substrate concentrations, inhibition occurred. Ca2+ concentration did not affect biocatalyst activity. The kinetic parameters (both for conversion and inactivation) were determined as a function of temperature by fitting the complete kinetic model, featuring substrate inhibition, competitive product inhibition and first-order irreversible biocatalyst inactivation, at different temperatures simultaneously through three extended data sets of substrate concentration versus time. Temperature affected both the conversion and inactivation parameters. The final model was used to calculate the substrate and biocatalyst costs per mmol of product in a continuous system with biocatalyst replenishment and biocatalyst recycling. Despite the effect of temperature on each kinetic parameter separately, the overall effect of temperature on the costs was found to be negligible (between 293 and 308 K). Within pertinent ranges, the sum of the substrate and biocatalyst costs per mmol of product was calculated to decrease with the influent substrate concentration and the residence time. The sum of the costs showed a minimum as a function of the influent biocatalyst concentration.

Heat inactivation of leaf phosphoenolpyruvate carboxylase: Protection by aspartate and malate in C4 plants.

Science.gov (United States)

Rathnam, C K

1978-01-01

The activity of phosphoenolpyruvate (PEP) carboxylase EC 4.1.1.31 in leaf extracts of Eleusine indica L. Gaertn., a C4 plant, exhibited a temperature optimum of 35-37° C with a complete loss of activity at 50° C. However, the enzyme was protected effectively from heat inactivation up to 55° C by L-aspartate. Activation energies (Ea) for the enzyme in the presence of aspartate were 2.5 times lower than that of the control enzyme. Arrhenius plots of PEP carboxylase activity (±aspartate) showed a break in the slope around 17-20° C with a 3-fold increase in the Ea below the break. The discontinuity in the slopes was abolished by treating the enzyme extracts with Triton X-100, suggesting that PEP carboxylase in C4 plants is associated with lipid and may be a membrane bound enzyme. Depending upon the species, the major C4 acid formed during photosynthesis (malate or aspartate) was found to be more protective than the minor C4 acid against the heat inactivation of their PEP carboxylase. Oxaloacetate, the reaction product, was less effective compared to malate or aspartate. Several allosteric inhibitors of PEP carboxylase were found to be moderately to highly effective in protecting the C4 enzyme while its activators showed no significant effect. PEP carboxylase from C3 species was not protected from thermal inactivation by the C4 acids. The physiological significance of these results is discussed in relation to the high temperature tolerance of C4 plants.

Shielding gas effect to diffusion activities of magnesium and copper on aluminum clad

Science.gov (United States)

Manurung, Charles SP; Napitupulu, Richard AM

2017-09-01

Aluminum is the second most metal used in many application, because of its corrosion resistance. The Aluminum will be damaged in over time if it’s not maintained in good condition. That is important to give protection to the Aluminums surface. Cladding process is one of surface protection methodes, especially for metals. Aluminum clad copper (Al/Cu) or copper clad aluminum (Cu/Al) composite metals have been widely used for many years. These mature protection method and well tested clad metal systems are used industrially in a variety application. The inherent properties and behavior of both copper and aluminum combine to provide unique performance advantages. In this paper Aluminum 2024 series will be covered with Aluminum 1100 series by hot rolling process. Observations will focus on diffusion activities of Mg and Cu that not present on Aluminum 1100 series. The differences of clad material samples is the use of shielding gas during heating before hot rolling process. The metallurgical characteristics will be examined by using optical microscopy. Transition zone from the interface cannot be observed but from Energy Dispersive Spectrometry it’s found that Mg and Cu are diffused from base metal (Al 2024) to the clad metal (Al 1100). Hardness test proved that base metals hardness to interface was decrease.

Doubling the CO{sub 2} concentration enhanced the activity of carbohydrate-metabolism enzymes, source carbohydrate production, photoassimilate transport, and sink strength for Opuntia ficus-indica

Energy Technology Data Exchange (ETDEWEB)

Wang, Ning; Nobel, P.S. [Univ. of California, Los Angeles, CA (United States)

1996-03-01

After exposure to a doubled CO{sub 2} concentration of 750 {mu}mol mol{sup -1} air for about 3 months, glucose and starch in the chlorenchyma of basal cladodes of Opuntia ficus-indica increased 175 and 57%, respectively, compared with the current CO{sub 2} concentration of 370 {mu}mol mol{sup -1}, but sucrose content was virtually unaffected. Doubling the CO{sub 2} concentration increased the noncturnal malate production in basal cladodes by 75%, inorganic phosphate (Pi) by 32% soluble starch synthase activity by 30%, and sucrose-Pi synthase activity by 146%, but did not affect the activity of hexokinase. Doubling CO{sub 2} accelerated phloem transport of sucrose out of the basal cladodes, resulting in a 73% higher dry weight for the daughter cladodes. Doubling CO{sub 2} increased the glucose content in 14-d-old daughter cladodes by 167%, increased nocturnal malate production by 22%, decreased total amino acid content by 61%, and increased soluble starch synthase activity by 30% and sucrose synthase activity by 62%. No downward acclimation of photosynthesis during long-term exposure to elevated CO{sub 2} concentrations occurs for O. ficus-indica, consistent with its higher source capacity and sink strength than under current CO{sub 2}. These changes apparently do not result in Pi limitation of photosynthesis or suppression of genes governing photosynthesis for this perennial Crassulacean acid metabolism species, as occur for some annual crops.

Long non-coding RNA MALAT1 acts as a competing endogenous RNA to promote malignant melanoma growth and metastasis by sponging miR-22.

Science.gov (United States)

Luan, Wenkang; Li, Lubo; Shi, Yan; Bu, Xuefeng; Xia, Yun; Wang, Jinlong; Djangmah, Henry Siaw; Liu, Xiaohui; You, Yongping; Xu, Bin

2016-09-27

Long non-coding RNAs (lncRNAs) are involved in tumorigenesis. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), an lncRNAs, is associated with the growth and metastasis of many human tumors, but its biological roles in malignant melanoma remain unclear. In this study, the aberrant up-regulation of MALAT1 was detected in melanoma. We determined that MALAT1 promotes melanoma cells proliferation, invasion and migration by sponging miR-22. MiR-22 was decreased and acted as a tumor suppressor in melanoma, and MMP14 and Snail were the functional targets of miR-22. Furthermore, MALAT1 could modulate MMP14 and Snail by operating as a competing endogenous RNA (ceRNA) for miR-22. The effects of MALAT1 in malignant melanoma is verified using a xenograft model. This finding elucidates a new mechanism for MALAT1 in melanoma development and provides a potential target for melanoma therapeutic intervention.

49 CFR 178.512 - Standards for steel or aluminum boxes.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for steel or aluminum boxes. 178.512... aluminum boxes. (a) The following are identification codes for steel or aluminum boxes: (1) 4A for a steel box; and (2) 4B for an aluminum box. (b) Construction requirements for steel or aluminum boxes are as...

Mutational analysis of the N-terminal topogenic signal of watermelon glyoxysomal malate dehydrogenase using the heterologous host Hansenula polymorpha

NARCIS (Netherlands)

Gietl, Christine; Faber, Klaas Nico; Klei, Ida J. van der; Veenhuis, Marten

1994-01-01

We have studied the significance of the N-terminal presequence of watermelon (Citrullus vulgaris) glyoxysomal malate dehydrogenase [gMDH; (S)-malate:NAD+ oxidoreductase; EC 1.1.1.37] in microbody targeting. The yeast Hansenula polymorpha was used as heterologous host for the in vivo expression of

Modeling and sensitivity analysis on the transport of aluminum oxide nanoparticles in saturated sand: effects of ionic strength, flow rate, and nanoparticle concentration.

Science.gov (United States)

Rahman, Tanzina; Millwater, Harry; Shipley, Heather J

2014-11-15

Aluminum oxide nanoparticles have been widely used in various consumer products and there are growing concerns regarding their exposure in the environment. This study deals with the modeling, sensitivity analysis and uncertainty quantification of one-dimensional transport of nano-sized (~82 nm) aluminum oxide particles in saturated sand. The transport of aluminum oxide nanoparticles was modeled using a two-kinetic-site model with a blocking function. The modeling was done at different ionic strengths, flow rates, and nanoparticle concentrations. The two sites representing fast and slow attachments along with a blocking term yielded good agreement with the experimental results from the column studies of aluminum oxide nanoparticles. The same model was used to simulate breakthrough curves under different conditions using experimental data and calculated 95% confidence bounds of the generated breakthroughs. The sensitivity analysis results showed that slow attachment was the most sensitive parameter for high influent concentrations (e.g. 150 mg/L Al2O3) and the maximum solid phase retention capacity (related to blocking function) was the most sensitive parameter for low concentrations (e.g. 50 mg/L Al2O3). Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of alkaline cleaning and activation on aluminum alloy 7075-T6

International Nuclear Information System (INIS)

Joshi, Simon; Fahrenholtz, William G.; O'Keefe, Matthew J.

2011-01-01

The effect of alkaline cleaning and activation on the composition and thickness of the oxide layer on aluminum alloy 7075-T6 was studied. E-pH diagrams were developed to predict the effect of alkaline cleaning and activation solutions on the stability of the oxide surface layers. The thickness of the native oxide layer was determined to be ∼30 nm by Auger electron spectroscopy depth profiling analysis. The outer ∼20 nm was rich in magnesium while the remaining ∼10 nm was rich in aluminum. Cleaning in a 9.1 pH alkaline solution was found to remove the magnesium-rich layer and leave behind an aluminum-rich oxide layer ∼10 nm thick. Activation in alkaline solutions of NaOH (pH > 12.9) or Na 2 CO 3 (pH > 11.5) produced an oxide that was ∼20 to 60 nm thick and rich in magnesium. Alkaline cleaning and activation altered the oxide composition and thickness making it possible for deposition of thicker cerium-based conversion coatings (∼100 to 250 nm) compared to only alkaline cleaning (∼30 nm), with application of one spray cycle of deposition solution.

Effect of alkaline cleaning and activation on aluminum alloy 7075-T6

Energy Technology Data Exchange (ETDEWEB)

Joshi, Simon, E-mail: sjwt5@mst.edu [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Fahrenholtz, William G.; O' Keefe, Matthew J. [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States)

2011-01-01

The effect of alkaline cleaning and activation on the composition and thickness of the oxide layer on aluminum alloy 7075-T6 was studied. E-pH diagrams were developed to predict the effect of alkaline cleaning and activation solutions on the stability of the oxide surface layers. The thickness of the native oxide layer was determined to be {approx}30 nm by Auger electron spectroscopy depth profiling analysis. The outer {approx}20 nm was rich in magnesium while the remaining {approx}10 nm was rich in aluminum. Cleaning in a 9.1 pH alkaline solution was found to remove the magnesium-rich layer and leave behind an aluminum-rich oxide layer {approx}10 nm thick. Activation in alkaline solutions of NaOH (pH > 12.9) or Na{sub 2}CO{sub 3} (pH > 11.5) produced an oxide that was {approx}20 to 60 nm thick and rich in magnesium. Alkaline cleaning and activation altered the oxide composition and thickness making it possible for deposition of thicker cerium-based conversion coatings ({approx}100 to 250 nm) compared to only alkaline cleaning ({approx}30 nm), with application of one spray cycle of deposition solution.

Serum long non coding RNA MALAT-1 protected by exosomes is up-regulated and promotes cell proliferation and migration in non-small cell lung cancer.

Science.gov (United States)

Zhang, Rui; Xia, Yuhong; Wang, Zhixin; Zheng, Jie; Chen, Yafei; Li, Xiaoli; Wang, Yu; Ming, Huaikun

2017-08-19

Circulating lncRNAs have been defined as a novel biomarker for non-small cell lung cancer (NSCLC), MALAT-1 was first identified lncRNA that was related to lung cancer metastasis. However, the relationship between exosomal lncRNAs and the diagnosis and prognosis of NSCLC was poorly understood. The aim of this study is to evaluate the clinical significance of serum exosomal MALAT-1 as a biomarker in the metastasis of NSCLC. In this study, we firstly isolated the exosomes from healthy subjects and NSCLC patients. Then we measured the expression levels of MALAT-1 contained in exosomes, and found that exosomal MALAT-1 was highly expressed in NSCLC patients, more importantly, the levels of exosomal MALAT-1 were positively associated with tumor stage and lymphatic metastasis. In addition, we decreased MALAT-1 expression by short hairpin RNA and conducted a series of assays including MTT, cell cycle, colony formation, wound-healing scratch and Annexin/V PI by flow cytometry in human lung cancer cell lines. These in vitro studies demonstrated that serum exosome-derived long noncoding RNA MALAT-1 promoted the tumor growth and migration, and prevented tumor cells from apoptosis in lung cancer cell lines. Taken together, this study shed a light on utilizing MALAT-1 in exosomes as a non-invasive serum-based tumor biomarker for diagnosis and prognosis of NSCLC. Copyright © 2017 Elsevier Inc. All rights reserved.

Identification of genes and pathways associated with aluminum stress and tolerance using transcriptome profiling of wheat near-isogenic lines

Directory of Open Access Journals (Sweden)

Diallo Amadou

2008-08-01

Full Text Available Abstract Background Aluminum is considered the most limiting factor for plant productivity in acidic soils, which cover large areas of the world's potential arable lands. The inhibition of root growth is recognized as the primary effect of Al toxicity. To identify genes associated with Al stress and tolerance, transcriptome analyses of four different wheat lines (2 Al-tolerant and 2 Al sensitive that differ in their response to Al were performed. Results Microarray expression profiling revealed that 83 candidate genes are associated with Al stress and 25 are associated with tolerance. The stress-associated genes include important enzymes such as pyruvate dehydrogenase, alternative oxidase, and galactonolactone oxidase, ABC transporter and ascorbate oxido-reducatase. The Al tolerance-associated genes include the ALMT-1 malate transporter, glutathione S-transferase, germin/oxalate oxidase, fructose 1,6-bisphosphatase, cysteine-rich proteins, cytochrome P450 monooxygenase, cellulose synthase, zinc finger transcription factor, disease resistance response protein and F-box containing domain protein. Conclusion In this survey, we identified stress- and tolerance-associated genes that may be involved in the detoxification of Al and reactive oxygen species. Alternative pathways could help maintain the supply of important metabolites (H2O2, ascorbate, NADH, and phosphate needed for Al tolerance and root growth. The Al tolerance-associated genes may be key factors that regulate these pathways.

Study the properties of activated carbon and oxyhydroxide aluminum as sorbents for removal humic substances from natural waters

International Nuclear Information System (INIS)

Shiyan, L N; Machekhina, K I; Gryaznova, E N

2016-01-01

The present work relates to the problem of high-quality drinking water supply using processes of adsorption on activated carbon and aluminum oxyhydroxide for removal humic- type organic substances. Also the paper reports on sorbtion properties of the activeted carbon Norit SA UF and oxyhydroxide aluminum for removal humic substances. It was found out that the maximum adsorption capacity of activated carbon to organic substances is equal to 0.25 mg/mg and aluminum oxyhydroxide is equal to 0.3 mg/mg. It is shown that the maximum adsorption capacity of activated carbon Norit SA UF to iron (III) ions is equal to 0.0045 mg/mg and to silicon ions is equal to 0.024 mg/mg. Consequently, the aluminum oxyhydroxide has better adsorption characteristics in comparison with the activated carbon for removal of humic substances, iron and silicon ions. It is associated with the fact that activated carbon has a large adsorption surface, and this is due to its porous structure, but not all molecules can enter into these pores. Therefore, the fibrous structure of aluminum oxyhydroxide promotes better sorption capacity. The presented results suggest that activated carbon Norit SA UF and aluminum oxyhydroxide can be used as sorbents for removal humic substances or other organic substances from groundwater and natural waters. (paper)

49 CFR 178.506 - Standards for metal drums other than steel or aluminum.

Science.gov (United States)

2010-10-01

... aluminum. 178.506 Section 178.506 Transportation Other Regulations Relating to Transportation PIPELINE AND... drums other than steel or aluminum. (a) The following are the identification codes for metal drums other than steel or aluminum: (1) 1N1 for a non-removable head metal drum; and (2) 1N2 for a removable head...

Ballistic phonon and thermal radiation transport across a minute vacuum gap in between aluminum and silicon thin films: Effect of laser repetitive pulses on transport characteristics

Science.gov (United States)

Yilbas, B. S.; Ali, H.

2016-08-01

Short-pulse laser heating of aluminum and silicon thin films pair with presence of a minute vacuum gap in between them is considered and energy transfer across the thin films pair is predicted. The frequency dependent Boltzmann equation is used to predict the phonon intensity distribution along the films pair for three cycles of the repetitive short-pulse laser irradiation on the aluminum film surface. Since the gap size considered is within the Casimir limit, thermal radiation and ballistic phonon contributions to energy transfer across the vacuum gap is incorporated. The laser irradiated field is formulated in line with the Lambert's Beer law and it is considered as the volumetric source in the governing equations of energy transport. In order to assess the phonon intensity distribution in the films pair, equivalent equilibrium temperature is introduced. It is demonstrated that thermal separation of electron and lattice sub-systems in the aluminum film, due to the short-pulse laser irradiation, takes place and electron temperature remains high in the aluminum film while equivalent equilibrium temperature for phonons decays sharply in the close region of the aluminum film interface. This behavior is attributed to the phonon boundary scattering at the interface and the ballistic phonon transfer to the silicon film across the vacuum gap. Energy transfer due to the ballistic phonon contribution is significantly higher than that of the thermal radiation across the vacuum gap.

Ballistic phonon and thermal radiation transport across a minute vacuum gap in between aluminum and silicon thin films: Effect of laser repetitive pulses on transport characteristics

Energy Technology Data Exchange (ETDEWEB)

Yilbas, B.S., E-mail: bsyilbas@kfupm.edu.sa; Ali, H.

2016-08-15

Short-pulse laser heating of aluminum and silicon thin films pair with presence of a minute vacuum gap in between them is considered and energy transfer across the thin films pair is predicted. The frequency dependent Boltzmann equation is used to predict the phonon intensity distribution along the films pair for three cycles of the repetitive short-pulse laser irradiation on the aluminum film surface. Since the gap size considered is within the Casimir limit, thermal radiation and ballistic phonon contributions to energy transfer across the vacuum gap is incorporated. The laser irradiated field is formulated in line with the Lambert's Beer law and it is considered as the volumetric source in the governing equations of energy transport. In order to assess the phonon intensity distribution in the films pair, equivalent equilibrium temperature is introduced. It is demonstrated that thermal separation of electron and lattice sub-systems in the aluminum film, due to the short-pulse laser irradiation, takes place and electron temperature remains high in the aluminum film while equivalent equilibrium temperature for phonons decays sharply in the close region of the aluminum film interface. This behavior is attributed to the phonon boundary scattering at the interface and the ballistic phonon transfer to the silicon film across the vacuum gap. Energy transfer due to the ballistic phonon contribution is significantly higher than that of the thermal radiation across the vacuum gap.

Ballistic phonon and thermal radiation transport across a minute vacuum gap in between aluminum and silicon thin films: Effect of laser repetitive pulses on transport characteristics

International Nuclear Information System (INIS)

Yilbas, B.S.; Ali, H.

2016-01-01

Short-pulse laser heating of aluminum and silicon thin films pair with presence of a minute vacuum gap in between them is considered and energy transfer across the thin films pair is predicted. The frequency dependent Boltzmann equation is used to predict the phonon intensity distribution along the films pair for three cycles of the repetitive short-pulse laser irradiation on the aluminum film surface. Since the gap size considered is within the Casimir limit, thermal radiation and ballistic phonon contributions to energy transfer across the vacuum gap is incorporated. The laser irradiated field is formulated in line with the Lambert's Beer law and it is considered as the volumetric source in the governing equations of energy transport. In order to assess the phonon intensity distribution in the films pair, equivalent equilibrium temperature is introduced. It is demonstrated that thermal separation of electron and lattice sub-systems in the aluminum film, due to the short-pulse laser irradiation, takes place and electron temperature remains high in the aluminum film while equivalent equilibrium temperature for phonons decays sharply in the close region of the aluminum film interface. This behavior is attributed to the phonon boundary scattering at the interface and the ballistic phonon transfer to the silicon film across the vacuum gap. Energy transfer due to the ballistic phonon contribution is significantly higher than that of the thermal radiation across the vacuum gap.

Development of high-strength aluminum alloys for basket in transport and storage cask for high burn-up spent fuel

International Nuclear Information System (INIS)

Maeguchi, T.; Sakaguchi, Y.; Kamiwaki, Y.; Ishii, M.; Yamamoto, T.

2004-01-01

Mitsubishi Heavy Industries, Ltd. (MHI) has developed high-strength borated aluminum alloys (high-strength B-Al alloys), suitable for application to baskets in transport and storage casks for high burn-up spent fuels. Aluminum is a suitable base material for the baskets due to its low density and high thermal conductivity. The aluminum basket would reduce weight of the cask, and effectively release heat generated by spent fuels. MHI had already developed borated aluminum alloys (high-toughness B-Al alloy), and registered them as ASME Code Case ''N-673''. However, there has been a strong demand for basket materials with higher strength in the case of MSF (Mitsubishi Spent Fuel) casks for high-burn up spent fuels, since the basket is required to stand up to higher stress at higher temperature. The high-strength basket material enables the design of a compact cask under a limitation of total size and weight. MHI has developed novel high-strength B-Al alloys which meet these requirements, based on a new manufacturing process. The outline of mechanical and metallurgical characteristics of the high-strength B-Al alloys is described in this paper

Inhibition of several enzymes by gold compounds. II. beta-Glucuronidase, acid phosphatase and L-malate dehydrogenase by sodium thiomalatoraurate (I), sodium thiosulfatoaurate (I) and thioglucosoaurate (I).

Science.gov (United States)

Lee, M T; Ahmed, T; Haddad, R; Friedman, M E

1989-01-01

Bovine liver beta-D-glucuronide glucuronohydrolase, EC 3.2.1.32), wheat germ acid phosphatase (orthophosphoric monoesterphosphohydrolase, EC 3.1.3.2) and bovine liver L-malate dehydrogenase (L-malate: NAD oxidoreductase, EC 1.1.1.37) were inhibited by a series of gold (I) complexes that have been used as anti-inflammatory drugs. Both sodium thiosulfatoaurate (I) (Na AuTs) and sodium thiomalatoraurate (NaAuTM) effectively inhibited all three enzymes, while thioglucosoaurate (I) (AuTG) only inhibited L-malate dehydrogenase. The equilibrium constants (K1) ranged from nearly 4000 microM for the NaAuTM-beta-glucuronidase interaction to 24 microM for the NaAuTS-beta-glucuronidase interaction. The rate of covalent bond formation (kp) ranged from 0.00032 min-1 for NaAuTM-beta-glucuronidase formation to 1.7 min-1 for AuTG-L-malate dehydrogenase formation. The equilibrium data shows that the gold (I) drugs bind by several orders lower than the gold (III) compounds, suggesting a significantly stronger interaction between the more highly charged gold ion and the enzyme. Yet the rate of covalent bond formation depends as much on the structure of the active site as upon the lability of the gold-ligand bond. It was also observed that the more effective the gold inhibition the more toxic the compound.

Utilization of L-aspartate, L-malate and fumarate by Pasteurella multocida

Energy Technology Data Exchange (ETDEWEB)

Hoefer, M.; Flossmann, K.D. (Akademie der Landwirtschaftswissenschaften der DDR, Jena. Inst. fuer Bakterielle Tierseuchenforschung)

1981-01-01

Strains of Pasteurella multocida use L-aspartate, L-malate and furmarate, respectively, as substrates for production of succinic acid which accumulates in the medium. As was established by studies with /sup 14/C- and /sup 3/H-labelled substrates, the degradation of these substances proceeds analogously via the citric acid cycle.

Utilization of L-aspartate, L-malate and fumarate by Pasteurella multocida

International Nuclear Information System (INIS)

Hoefer, M.; Flossmann, K.D.

1981-01-01

Strains of Pasteurella multocida use L-aspartate, L-malate and furmarate, respectively, as substrates for production of succinic acid which accumulates in the medium. As was established by studies with 14 C- and 3 H-labelled substrates, the degradation of these substances proceeds analogously via the citric acid cycle. (author)

CONTAINMENT ANALYSIS METHODOLOGY FOR TRANSPORT OF BREACHED CLAD ALUMINUM SPENT FUEL

Energy Technology Data Exchange (ETDEWEB)

Vinson, D.

2010-07-11

Aluminum-clad, aluminum-based spent nuclear fuel (Al-SNF) from foreign and domestic research reactors (FRR/DRR) is being shipped to the Savannah River Site and placed in interim storage in a water basin. To enter the United States, a cask with loaded fuel must be certified to comply with the requirements in the Title 10 of the U.S. Code of Federal Regulations, Part 71. The requirements include demonstration of containment of the cask with its contents under normal and accident conditions. Many Al-SNF assemblies have suffered corrosion degradation in storage in poor quality water, and many of the fuel assemblies are 'failed' or have through-clad damage. A methodology was developed to evaluate containment of Al-SNF even with severe cladding breaches for transport in standard casks. The containment analysis methodology for Al-SNF is in accordance with the methodology provided in ANSI N14.5 and adopted by the U. S. Nuclear Regulatory Commission in NUREG/CR-6487 to meet the requirements of 10CFR71. The technical bases for the inputs and assumptions are specific to the attributes and characteristics of Al-SNF received from basin and dry storage systems and its subsequent performance under normal and postulated accident shipping conditions. The results of the calculations for a specific case of a cask loaded with breached fuel show that the fuel can be transported in standard shipping casks and maintained within the allowable release rates under normal and accident conditions. A sensitivity analysis has been conducted to evaluate the effects of modifying assumptions and to assess options for fuel at conditions that are not bounded by the present analysis. These options would include one or more of the following: reduce the fuel loading; increase fuel cooling time; reduce the degree of conservatism in the bounding assumptions; or measure the actual leak rate of the cask system. That is, containment analysis for alternative inputs at fuel-specific conditions and

Tingkat Kerentanan Aedes aegypti (Linn. terhadap Malation di Provinsi Sumatera Selatan

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Lasbudi P. Ambarita

2015-07-01

Full Text Available AbstractDengue vector control program in Indonesia and also South Sumatera Province has been using malathion quite long enough. The extensive use of chemical in dengue vector control can lead to development of resistance. This study aims to determine the susceptibility of Aedes aegypti against malathion in 11 district of South Sumatera Province. Larva or pupae were collected with entomology survey kit and colonized until first generation (F1 that were used for bioassay. This test was conducted according to WHO adult susceptibility bioassay procedure.Twenty five blood-fed mosquitoes were exposed to insecticide impregnated paper in each of 4 WHO test kits and 1 control tube. Aedes aegypti from all study sites were still susceptible to operational dose of malathion (5%after 1 hour exposure. The estimated resistance ratio (ERR of knockdown time (KT to operasional dose of malathion is about 1,02 – 1,27 for KT50 and 0,96 – 1,24 for KT95. The susceptibility test of adult mosquitoes to diagnostic dose (0,8% of malathion showed a variety of susceptibility after 24 hours. Strain of 7 districts showed resistance, 3 districts toleran and 1 district still susceptible. The detection of resistance can actually help public health personnel to formulate appropriate steps in encountering the reduction in effectiveness of vector control efforts.Keywords : Aedes aegypti, Malathion, Susceptibility, South SumateraAbstrakProgram pengendalian vektor DBD di Indonesia termasuk di Provinsi Sumatera Selatan telah cukup lama menggunakan malation dengan konsentrasi 5%. Penggunaan satu jenis insektisida kimiawi secara ekstensif dapat memicu perkembangan resistensi. Penelitian ini bertujuan untuk menentukan status kerentanan Aedes aegypti terhadap malation dari 11 kabupaten/kota di Provinsi Sumatera Selatan. Larva atau pupa dikumpulkan menggunakan alat survei entomologi dan selanjutnyadipelihara hingga mendapatkan generasi pertama (F1 yang akan digunakan pada uji

Citrate, malate and alkali content in commonly consumed diet sodas: implications for nephrolithiasis treatment.

Science.gov (United States)

Eisner, Brian H; Asplin, John R; Goldfarb, David S; Ahmad, Ardalanejaz; Stoller, Marshall L

2010-06-01

Citrate is a known inhibitor of calcium stone formation. Dietary citrate and alkali intake may have an effect on citraturia. Increasing alkali intake also increases urine pH, which can help prevent uric acid stones. We determined citrate, malate and total alkali concentrations in commonly consumed diet sodas to help direct dietary recommendations in patients with hypocitraturic calcium or uric acid nephrolithiasis. Citrate and malate were measured in a lemonade beverage commonly used to treat hypocitraturic calcium nephrolithiasis and in 15 diet sodas. Anions were measured by ion chromatography. The pH of each beverage was measured to allow calculation of the unprotonated anion concentration using the known pK of citric and malic acid. Total alkali equivalents were calculated for each beverage. Statistical analysis was done using Pearson's correlation coefficient. Several sodas contained an amount of citrate equal to or greater than that of alkali and total alkali as a lemonade beverage commonly used to treat hypocitraturic calcium nephrolithiasis (6.30 mEq/l citrate as alkali and 6.30 as total alkali). These sodas were Diet Sunkist Orange, Diet 7Up, Sprite Zero, Diet Canada Dry Ginger Ale, Sierra Mist Free, Diet Orange Crush, Fresca and Diet Mountain Dew. Colas, including Caffeine Free Diet Coke, Coke Zero, Caffeine Free Diet Pepsi and Diet Coke with Lime, had the lowest total alkali (less than 1.0 mEq/l). There was no significant correlation between beverage pH and total alkali content. Several commonly consumed diet sodas contain moderate amounts of citrate as alkali and total alkali. This information is helpful for dietary recommendations in patients with calcium nephrolithiasis, specifically those with hypocitraturia. It may also be useful in patients with low urine pH and uric acid stones. Beverage malate content is also important since malate ingestion increases the total alkali delivered, which in turn augments citraturia and increases urine pH. Copyright

Conjugated fatty acids and methane production by rumen microbes when incubated with linseed oil alone or mixed with fish oil and/or malate.

Science.gov (United States)

Li, Xiang Z; Gao, Qing S; Yan, Chang G; Choi, Seong H; Shin, Jong S; Song, Man K

2015-08-01

We hypothesized that manipulating metabolism with fish oil and malate as a hydrogen acceptor would affect the biohydrogenation process of α-linolenic acid by rumen microbes. This study was to examine the effect of fish oil and/or malate on the production of conjugated fatty acids and methane (CH4 ) by rumen microbes when incubated with linseed oil. Linseed oil (LO), LO with fish oil (LO-FO), LO with malate (LO-MA), or LO with fish oil and malate (LO-FO-MA) was added to diluted rumen fluid, respectively. The LO-MA and LO-FO-MA increased pH and propionate concentration compared to the other treatments. LO-MA and LO-FO-MA reduced CH4 production compared to LO. LO-MA and LO-FO-MA increased the contents of c9,t11-conjugated linoleic acid (CLA) and c9,t11,c15-conjugated linolenic acid (CLnA) compared to LO. The content of malate was rapidly reduced while that of lactate was reduced in LO-MA and LO-FO-MA from 3 h incubation time. The fold change of the quantity of methanogen related to total bacteria was decreased at both 3 h and 6 h incubation times in all treatments compared to the control. Overall data indicate that supplementation of combined malate and/or fish oil when incubated with linseed oil, could depress methane generation and increase production of propionate, CLA and CLnA under the conditions of the current in vitro study. © 2015 Japanese Society of Animal Science.

Aluminum stimulates uptake of non-transferrin bound iron and transferrin bound iron in human glial cells

International Nuclear Information System (INIS)

Kim, Yongbae; Olivi, Luisa; Cheong, Jae Hoon; Maertens, Alex; Bressler, Joseph P.

2007-01-01

Aluminum and other trivalent metals were shown to stimulate uptake of transferrin bound iron and nontransferrin bound iron in erytholeukemia and hepatoma cells. Because of the association between aluminum and Alzheimer's Disease, and findings of higher levels of iron in Alzheimer's disease brains, the effects of aluminum on iron homeostasis were examined in a human glial cell line. Aluminum stimulated dose- and time-dependent uptake of nontransferrin bound iron and iron bound to transferrin. A transporter was likely involved in the uptake of nontransferrin iron because uptake reached saturation, was temperature-dependent, and attenuated by inhibitors of protein synthesis. Interestingly, the effects of aluminum were not blocked by inhibitors of RNA synthesis. Aluminum also decreased the amount of iron bound to ferritin though it did not affect levels of divalent metal transporter 1. These results suggest that aluminum disrupts iron homeostasis in Brain by several mechanisms including the transferrin receptor, a nontransferrin iron transporter, and ferritin

The crystal structures of the tri-functional Chloroflexus aurantiacus and bi-functional Rhodobacter sphaeroides malyl-CoA lyases and comparison with CitE-like superfamily enzymes and malate synthases.

Science.gov (United States)

Zarzycki, Jan; Kerfeld, Cheryl A

2013-11-09

Malyl-CoA lyase (MCL) is a promiscuous carbon-carbon bond lyase that catalyzes the reversible cleavage of structurally related Coenzyme A (CoA) thioesters. This enzyme plays a crucial, multifunctional role in the 3-hydroxypropionate bi-cycle for autotrophic CO2 fixation in Chloroflexus aurantiacus. A second, phylogenetically distinct MCL from Rhodobacter sphaeroides is involved in the ethylmalonyl-CoA pathway for acetate assimilation. Both MCLs belong to the large superfamily of CitE-like enzymes, which includes the name-giving β-subunit of citrate lyase (CitE), malyl-CoA thioesterases and other enzymes of unknown physiological function. The CitE-like enzyme superfamily also bears sequence and structural resemblance to the malate synthases. All of these different enzymes share highly conserved catalytic residues, although they catalyze distinctly different reactions: C-C bond formation and cleavage, thioester hydrolysis, or both (the malate synthases). Here we report the first crystal structures of MCLs from two different phylogenetic subgroups in apo- and substrate-bound forms. Both the C. aurantiacus and the R. sphaeroides MCL contain elaborations on the canonical β8/α8 TIM barrel fold and form hexameric assemblies. Upon ligand binding, changes in the C-terminal domains of the MCLs result in closing of the active site, with the C-terminal domain of one monomer forming a lid over and contributing side chains to the active site of the adjacent monomer. The distinctive features of the two MCL subgroups were compared to known structures of other CitE-like superfamily enzymes and to malate synthases, providing insight into the structural subtleties that underlie the functional versatility of these enzymes. Although the C. aurantiacus and the R. sphaeroides MCLs have divergent primary structures (~37% identical), their tertiary and quaternary structures are very similar. It can be assumed that the C-C bond formation catalyzed by the MCLs occurs as proposed for

Phonon transport in a curved aluminum thin film due to laser short pulse irradiation

Science.gov (United States)

Mansoor, Saad Bin; Yilbas, Bekir Sami

2018-05-01

Laser short-pulse heating of a curved aluminum thin film is investigated. The Boltzmann transport equation is incorporated to formulate the heating situation. A Gaussian laser intensity distribution is considered along the film arc and time exponentially decaying of pulse intensity is incorporated in the analysis. The governing equations of energy transport in the electron and lattice sub-systems are coupled through the electron-phonon coupling parameter. To quantify the phonon intensity distribution in the thin film, equivalent equilibrium temperature is introduced, which is associated with the average energy of all phonons around a local point when the phonon energies are redistributed adiabatically to an equilibrium state. It is found the numerical simulations that electron temperature follows similar trend to the spatial distribution of the laser pulse intensity at the film edge. Temporal variation of electron temperature does not follow the laser pulse intensity distribution. The rise of temperature in the electron sub-system is fast while it remains slow in the lattice sub-system.

Preparation and thermal properties of form-stable palmitic acid/active aluminum oxide composites as phase change materials for latent heat storage

International Nuclear Information System (INIS)

Fang, Guiyin; Li, Hui; Cao, Lei; Shan, Feng

2012-01-01

Form-stable palmitic acid (PA)/active aluminum oxide composites as phase change materials were prepared by adsorbing liquid palmitic acid into active aluminum oxide. In the composites, the palmitic acid was used as latent heat storage materials, and the active aluminum oxide was used as supporting material. Fourier transformation infrared spectroscope (FT-IR), X-ray diffractometer (XRD) and scanning electronic microscope (SEM) were used to determine the chemical structure, crystalloid phase and microstructure of the composites, respectively. The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetry analyzer (TGA). The FT-IR analyses results indicated that there is no chemical interaction between the palmitic acid and active aluminum oxide. The SEM results showed that the palmitic acid was well adsorbed into porous network of the active aluminum oxide. The DSC results indicated that the composites melt at 60.25 °C with a latent heat of 84.48 kJ kg −1 and solidify at 56.86 °C with a latent heat of 78.79 kJ kg −1 when the mass ratio of the PA to active aluminum oxide is 0.9:1. Compared with that of the PA, the melting and solidifying time of the composites CPCM5 was reduced by 20.6% and 21.4% because of the increased heat transfer rate through EG addition. The TGA results showed that the active aluminum oxide can improve the thermal stability of the composites. -- Highlights: ► Form-stable PA/active aluminum oxide composites as PCMs were prepared. ► Chemical structure, crystalloid phase and microstructure of composites were determined. ► Thermal properties and thermal stability of the composites were investigated. ► Expanded graphite can improve thermal conductivity of the composites.

Tonoplast- and plasma membrane-localized aquaporin-family transporters in blue hydrangea sepals of aluminum hyperaccumulating plant.

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Takashi Negishi

Full Text Available Hydrangea (Hydrangea macrophylla is tolerant of acidic soils in which toxicity generally arises from the presence of the soluble aluminum (Al ion. When hydrangea is cultivated in acidic soil, its resulting blue sepal color is caused by the Al complex formation of anthocyanin. The concentration of vacuolar Al in blue sepal cells can reach levels in excess of approximately 15 mM, suggesting the existence of an Al-transport and/or storage system. However, until now, no Al transporter has been identified in Al hyperaccumulating plants, animals or microorganisms. To identify the transporter being responsible for Al hyperaccumulation, we prepared a cDNA library from blue sepals according to the sepal maturation stage, and then selected candidate genes using a microarray analysis and an in silico study. Here, we identified the vacuolar and plasma membrane-localized Al transporters genes vacuolar Al transporter (VALT and plasma membrane Al transporter 1 (PALT1, respectively, which are both members of the aquaporin family. The localization of each protein was confirmed by the transient co-expression of the genes. Reverse transcription-PCR and immunoblotting results indicated that VALT and PALT1 are highly expressed in sepal tissue. The overexpression of VALT and PALT1 in Arabidopsis thaliana conferred Al-tolerance and Al-sensitivity, respectively.

Photothermally activated motion and ignition using aluminum nanoparticles

International Nuclear Information System (INIS)

Abboud, Jacques E.; Chong Xinyuan; Zhang Mingjun; Zhang Zhili; Jiang Naibo; Roy, Sukesh; Gord, James R.

2013-01-01

The aluminum nanoparticles (Al NPs) are demonstrated to serve as active photothermal media, to enhance and control local photothermal energy deposition via the photothermal effect activated by localized surface plasmon resonance (LSPR) and amplified by Al NPs oxidation. The activation source is a 2-AA-battery-powered xenon flash lamp. The extent of the photothermally activated movement of Al NPs can be ∼6 mm. Ignition delay can be ∼0.1 ms. Both scanning electron microscopy and energy-dispersive X-ray spectroscopy measurements of motion-only and after-ignition products confirm significant Al oxidation occurs through sintering and bursting after the flash exposure. Simulations suggest local heat generation is enhanced by LSPR. The positive-feedback effects from the local heat generation amplified by Al oxidation produce a large increase in local temperature and pressure, which enhances movement and accelerates ignition.

Reconstruction of Oryza sativa indica Genome Scale Metabolic Model and Its Responses to Varying RuBisCO Activity, Light Intensity, and Enzymatic Cost Conditions

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Ankita Chatterjee

2017-11-01

Full Text Available To combat decrease in rice productivity under different stresses, an understanding of rice metabolism is needed. Though there are different genome scale metabolic models (GSMs of Oryza sativa japonica, no GSM with gene-protein-reaction association exist for Oryza sativa indica. Here, we report a GSM, OSI1136 of O.s. indica, which includes 3602 genes and 1136 metabolic reactions and transporters distributed across the cytosol, mitochondrion, peroxisome, and chloroplast compartments. Flux balance analysis of the model showed that for varying RuBisCO activity (Vc/Vo (i the activity of the chloroplastic malate valve increases to transport reducing equivalents out of the chloroplast under increased photorespiratory conditions and (ii glyceraldehyde-3-phosphate dehydrogenase and phosphoglycerate kinase can act as source of cytosolic ATP under decreased photorespiration. Under increasing light conditions we observed metabolic flexibility, involving photorespiration, chloroplastic triose phosphate and the dicarboxylate transporters of the chloroplast and mitochondrion for redox and ATP exchanges across the intracellular compartments. Simulations under different enzymatic cost conditions revealed (i participation of peroxisomal glutathione-ascorbate cycle in photorespiratory H2O2 metabolism (ii different modes of the chloroplastic triose phosphate transporters and malate valve, and (iii two possible modes of chloroplastic Glu–Gln transporter which were related with the activity of chloroplastic and cytosolic isoforms of glutamine synthetase. Altogether, our results provide new insights into plant metabolism.

Uncovering driving forces on greenhouse gas emissions in China’ aluminum industry from the perspective of life cycle analysis

International Nuclear Information System (INIS)

Liu, Zhe; Geng, Yong; Adams, Michelle; Dong, Liang; Sun, Lina; Zhao, Jingjing; Dong, Huijuan; Wu, Jiao; Tian, Xu

2016-01-01

Highlights: • Energy-related GHG emission trajectories, features and driving forces of CAI are analyzed from the perspective of LCA. • CAI experienced a rapid growth of energy-related GHG emissions from 2004 to 2013. • Energy-scale effect is the main driving force for energy-related GHG emissions increase in CAI. • Construction and transportation-related activities account for more than 40% of the total embodied emissions. • Policy implications such as developing secondary aluminum industry, improving energy mix etc, are raised. - Abstract: With the rapid growth of aluminum production, reducing greenhouse gas (GHG) emissions in China’s aluminum industry (CAI) is posing a significant challenge. In this study, the energy-related GHG emission trajectories, features and driving forces of CAI are analyzed from the perspective of life cycle analysis (LCA) from 2004 to 2013. Results indicate that CAI experienced a rapid growth of energy-related GHG emissions with an average annual growth of 28.5 million tons CO_2e from 2004 to 2013. Energy-scale effect is the main driving force for energy-related GHG emissions increase in CAI, while emission-factor effect of secondary aluminum production plays a marginal effect. Construction and transportation-related activities account for the bulk of the embodied emissions, accounting for more than 40% of the total embodied emissions from CAI. Policy implications for GHG mitigation within the CAI, such as developing secondary aluminum industry, improving energy mix and optimizing resource efficiency of production, are raised.

Improvement of carrier transport and luminous efficiency of organic light emitting diodes by introducing a co-deposited active layer

Energy Technology Data Exchange (ETDEWEB)

Ohtani, Naoki; Murata, Masaya; Kashiwabara, Keiichiro; Kurata, Kazunori, E-mail: ohtani@mail.doshisha.ac.j [Department of Electronics, Doshisha University, 3-1 Tatara-Miyakodani, Kyotanabe-shi, Kyoto 610-0321 (Japan)

2009-11-15

We evaluated carrier transport and luminous efficiency of organic light-emitting diodes (OLEDs) whose active regions consist of a single co-deposited layer. One organic material is a hole transport material N,N'-Bis(3-methylphenyl)-N,N'-diphenylbenzidine (TPD), while the other is an electron transport/emissive material Tris(8-hydroxyquinolinato)-aluminum (Alq3). It was found that the luminous efficiency strongly depends on the thickness and the ratio of the TPD:Alq3 co-deposited layer. This indicates that the carrier balance in the active region can be improved by changing the co-deposited layers. In addition, we performed the dye-doping method to clarify the recombination region. As a result, we found that the radiative recombination is caused in the whole TPD:Alq3 co-deposited layer.

Convenient method of simultaneously analyzing aluminum and magnesium in pharmaceutical dosage forms using californium-252 thermal neutron activation

International Nuclear Information System (INIS)

Landolt, R.R.; Hem, S.L.

1983-01-01

A commercial antacid suspension containing aluminum hydroxide and magnesium hydroxide products was used as a model sample to study the use of a californium-252 thermal neutron activation as a method for quantifying aluminum content as well as for the simultaneous assay of aluminum and magnesium. A 3.5-micrograms californium-252 source was used for the activation, and the induced aluminum-28 and magnesium-27 activity was simultaneously measured by sodium iodide crystal gamma-ray spectrometry using dual single-channel analyzers and scalers. The antacid suspension was contained in a chamber designed with the unique capability of serving as the container for counting the induced radioactivity in addition to being the irradiation chamber itself. This pilot study demonstrated that use of more intense californium-252 sources, which are commonly available, would provide a method that is competitive with the ethylenediaminetetraacetic acid titration method in precision and in other aspects as well

Analysis of copper and uranyl malates by potentiometry, polarimetry and spectrophotometry

Energy Technology Data Exchange (ETDEWEB)

Khalil, I; Petit-Ramel, M M; Chapelet-Barbier, C [Lyon-1 Univ., 69 (France)

1978-07-15

The stability and optical constants of the copper malates (CuH/sub 2/Mal)/sup +/, (CuHMal), (CuH/sub 2/Mal/sub 2/)/sup 2 -/, (CuMal)/sup -/, (Cu/sub 2/Mal/sub 2/)/sup 2 -/, and (CuHsub(-1)Mal)/sup 2 -/ have been fitted by a pit-mapping method, which also gives their confidence limits, from potentiometric, visible spectroscopic and polarimetric measurements.

PHYSIOLOGY OF ION TRANSPORT ACROSS THE TONOPLAST OF HIGHER PLANTS.

Science.gov (United States)

Barkla, Bronwyn J.; Pantoja, Omar

1996-06-01

The vacuole of plant cells plays an important role in the homeostasis of the cell. It is involved in the regulation of cytoplasmic pH, sequestration of toxic ions and xenobiotics, regulation of cell turgor, storage of amino acids, sugars and CO2 in the form of malate, and possibly as a source for elevating cytoplasmic calcium. All these activities are driven by two primary active transport mechanisms present in the vacuolar membrane (tonoplast). These two mechanisms employ high-energy metabolites to pump protons into the vacuole, establishing a proton electrochemical potential that mediates the transport of a diverse range of solutes. Within the past few years, great advances at the molecular and functional levels have been made on the characterization and identification of these mechanisms. The aim of this review is to summarize these studies in the context of the physiology of the plant cell.

Carbon isotope composition of intermediates of the starch-malate sequence and level of the crassulacean acid metabolism in leaves of Kalanchoe blossfeldiana Tom Thumb.

Science.gov (United States)

Deleens, E; Garnier-Dardart, J; Queiroz, O

1979-09-01

Isotype analyses were performed on biochemical fractions isolated from leaves of Kalanchoe blossfeldiana Tom Thumb. during aging under long days or short days. Irrespective of the age or photoperiodic conditions, the intermediates of the starch-malate sequence (starch, phosphorylated compounds and organic acids) have a level of (13)C higher than that of soluble sugars, cellulose and hemicellulose. In short days, the activity of the crassulacean acid metabolism pathway is predominant as compared to that of C3 pathway: leaves accumulate organic acids, rich in (13)C. In long days, the activity of the crassulacean acid metabolism pathway increases as the leaves age, remaining, however, relatively low as compared to that of C3 pathway: leaves accumulate soluble sugars, poor in (13)C. After photoperiodic change (long days→short days), isotopic modifications of starch and organic acids suggest evidence for a lag phase in the establishment of the crassulacean acid metabolism pathway specific to short days. The relative proportions of carbon from a C3-origin (RuBPC acitivity as strong discriminating step, isotope discrimination in vivo=20‰) or C4-origin (PEPC activity as weak discriminating step, isotope discrimination in vivo=4‰) present in the biochemical fractions were calculated from their δ(13)C values. Under long days, 30 to 70% versus 80 to 100% under short days, of the carbon of the intermediates linked to the starch-malate sequence, or CAM pathway (starch, phosphorylated compounds and organic acids), have a C4-origin. Products connected to the C3 pathway (free sugars, cellulose, hemicellulose) have 0 to 50% of their carbon, arising from reuptake of the C4 from malate, under long days versus 30 to 70% under short days.

A co-expression gene network associated with developmental regulation of apple fruit acidity.

Science.gov (United States)

Bai, Yang; Dougherty, Laura; Cheng, Lailiang; Xu, Kenong

2015-08-01

Apple fruit acidity, which affects the fruit's overall taste and flavor to a large extent, is primarily determined by the concentration of malic acid. Previous studies demonstrated that the major QTL malic acid (Ma) on chromosome 16 is largely responsible for fruit acidity variations in apple. Recent advances suggested that a natural mutation that gives rise to a premature stop codon in one of the two aluminum-activated malate transporter (ALMT)-like genes (called Ma1) is the genetic causal element underlying Ma. However, the natural mutation does not explain the developmental changes of fruit malate levels in a given genotype. Using RNA-seq data from the fruit of 'Golden Delicious' taken at 14 developmental stages from 1 week after full-bloom (WAF01) to harvest (WAF20), we characterized their transcriptomes in groups of high (12.2 ± 1.6 mg/g fw, WAF03-WAF08), mid (7.4 ± 0.5 mg/g fw, WAF01-WAF02 and WAF10-WAF14) and low (5.4 ± 0.4 mg/g fw, WAF16-WAF20) malate concentrations. Detailed analyses showed that a set of 3,066 genes (including Ma1) were expressed not only differentially (P FDR < 0.05) between the high and low malate groups (or between the early and late developmental stages) but also in significant (P < 0.05) correlation with malate concentrations. The 3,066 genes fell in 648 MapMan (sub-) bins or functional classes, and 19 of them were significantly (P FDR < 0.05) co-enriched or co-suppressed in a malate dependent manner. Network inferring using the 363 genes encompassed in the 19 (sub-) bins, identified a major co-expression network of 239 genes. Since the 239 genes were also differentially expressed between the early (WAF03-WAF08) and late (WAF16-WAF20) developmental stages, the major network was considered to be associated with developmental regulation of apple fruit acidity in 'Golden Delicious'.

Advanced powder metallurgy aluminum alloys and composites

Science.gov (United States)

Lisagor, W. B.; Stein, B. A.

1982-01-01

The differences between powder and ingot metallurgy processing of aluminum alloys are outlined. The potential payoff in the use of advanced powder metallurgy (PM) aluminum alloys in future transport aircraft is indicated. The national program to bring this technology to commercial fruition and the NASA Langley Research Center role in this program are briefly outlined. Some initial results of research in 2000-series PM alloys and composites that highlight the property improvements possible are given.

Combination of long noncoding RNA MALAT1 and carcinoembryonic antigen for the diagnosis of malignant pleural effusion caused by lung cancer.

Science.gov (United States)

Wang, Wan-Wei; Zhou, Xi-Lei; Song, Ying-Jian; Yu, Chang-Hua; Zhu, Wei-Guo; Tong, Yu-Suo

2018-01-01

Long noncoding RNAs (lncRNAs) are present in body fluids, but their potential as tumor biomarkers has never been investigated in malignant pleural effusion (MPE) caused by lung cancer. The aim of this study was to assess the clinical significance of lncRNAs in pleural effusion, which could potentially serve as diagnostic and predictive markers for lung cancer-associated MPE (LC-MPE). RNAs from pleural effusion were extracted in 217 cases of LC-MPE and 132 cases of benign pleural effusion (BPE). Thirty-one lung cancer-associated lncRNAs were measured using quantitative real-time polymerase chain reaction (qRT-PCR). The level of carcinoembryonic antigen (CEA) was also determined. The receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were established to evaluate the sensitivity and specificity of the identified lncRNAs and other biomarkers. The correlations between baseline pleural effusion lncRNAs expression and response to chemotherapy were also analyzed. Three lncRNAs ( MALAT1 , H19 , and CUDR ) were found to have potential as diagnostic markers in LC-MPE. The AUCs for MALAT1 , H19 , CUDR , and CEA were 0.891, 0.783, 0.824, and 0.826, respectively. Using a logistic model, the combination of MALAT1 and CEA (AUC, 0.924) provided higher sensitivity and accuracy in predicting LC-MPE than CEA (AUC, 0.826) alone. Moreover, baseline MALAT1 expression in pleural fluid was inversely correlated with chemotherapy response in patients with LC-MPE. Pleural effusion lncRNAs were effective in differentiating LC-MPE from BPE. The combination of MALAT1 and CEA was more effective for LC-MPE diagnosis.

Watermelon glyoxysomal malate dehydrogenase is sorted to peroxisomes of the methylotrophic yeast, Hansenula polymorpha

NARCIS (Netherlands)

Klei, I.J. van der; Faber, K.N.; Keizer-Gunnink, I.; Gietl, C.; Harder, W.; Veenhuis, M.

1993-01-01

We have studied the fate of the watermelon (Citrullus vulgaris Schrad.) glyoxysomal enzyme, malate dehydrogenase (gMDH), after synthesis in the methylotrophic yeast, Hansenula polymorpha. The gene encoding the precursor form of gMDH (pre-gMDH) was cloned in an H. polymorpha expression vector

Posttranscriptional silencing of the lncRNA MALAT1 by miR-217 inhibits the epithelial–mesenchymal transition via enhancer of zeste homolog 2 in the malignant transformation of HBE cells induced by cigarette smoke extract

International Nuclear Information System (INIS)

Lu, Lu; Luo, Fei; Liu, Yi; Liu, Xinlu; Shi, Le; Lu, Xiaolin; Liu, Qizhan

2015-01-01

Lung cancer is regarded as the leading cause of cancer-related deaths, and cigarette smoking is one of the strongest risk factors for the development of lung cancer. However, the mechanisms for cigarette smoke-induced lung carcinogenesis remain unclear. The present study investigated the effects of an miRNA (miR-217) on levels of an lncRNA (MALAT1) and examined the role of these factors in the epithelial–mesenchymal transition (EMT) induced by cigarette smoke extract (CSE) in human bronchial epithelial (HBE) cells. In these cells, CSE caused decreases of miR-217 levels and increases in lncRNA MALAT1 levels. Over-expression of miR-217 with a mimic attenuated the CSE-induced increase of MALAT1 levels, and reduction of miR-217 levels by an inhibitor enhanced expression of MALAT1. Moreover, the CSE-induced increase of MALAT1 expression was blocked by an miR-217 mimic, indicating that miR-217 negatively regulates MALAT1 expression. Knockdown of MALAT1 reversed CSE-induced increases of EZH2 (enhancer of zeste homolog 2) and H3K27me3 levels. In addition to the alteration from epithelial to spindle-like mesenchymal morphology, chronic exposure of HBE cells to CSE increased the levels of EZH2, H3K27me3, vimentin, and N-cadherin and decreased E-cadherin levels, effects that were reversed by MALAT1 siRNA or EZH2 siRNA. The results indicate that miR-217 regulation of EZH2/H3K27me3 via MALAT1 is involved in CSE-induced EMT and malignant transformation of HBE cells. The posttranscriptional silencing of MALAT1 by miR-217 provides a link, through EZH2, between ncRNAs and the EMT and establishes a mechanism for CSE-induced lung carcinogenesis. - Highlights: • CSE exposure decreases miR-217 levels and increases MALAT1 levels. • miR-217 negatively regulates MALAT1 expression. • MALAT1, via EZH2, is involved in the EMT of CSE-transformed HBE cells.

Aluminum Target Dissolution in Support of the Pu-238 Program

Energy Technology Data Exchange (ETDEWEB)

McFarlane, Joanna [ORNL; Benker, Dennis [ORNL; DePaoli, David W [ORNL; Felker, Leslie Kevin [ORNL; Mattus, Catherine H [ORNL

2014-09-01

Selection of an aluminum alloy for target cladding affects post-irradiation target dissolution and separations. Recent tests with aluminum alloy 6061 yielded greater than expected precipitation in the caustic dissolution step, forming up to 10 wt.% solids of aluminum hydroxides and aluminosilicates. We present a study to maximize dissolution of aluminum metal alloy, along with silicon, magnesium, and copper impurities, through control of temperature, the rate of reagent addition, and incubation time. Aluminum phase transformations have been identified as a function of time and temperature, using X-ray diffraction. Solutions have been analyzed using wet chemical methods and X-ray fluorescence. These data have been compared with published calculations of aluminum phase diagrams. Temperature logging during the transients has been investigated as a means to generate kinetic and mass transport data on the dissolution process. Approaches are given to enhance the dissolution of aluminum and aluminosilicate phases in caustic solution.

Structure of halophilic malate dehydrogenase in multimolar KCl solutions from neutron scattering and ultracentrifugation

International Nuclear Information System (INIS)

Calmettes, P.

1987-01-01

The structure and solvent interactions of malate dehydrogenase from Halobacterium marismortui in multimolar KCl solvents are found to be similar to those in multimolar NaCl solvents reported previously (G. Zaccai, E. Wachtel and H. Eisenberg, J. Mol. Biol. 190 (1986) 97). KCl rather than NaCl is predominant in physiological medium. At salt concentrations up to about 3.0 M, the protein (a dimer of M 87000 g/mol) can be considered to occupy an invariant volume in which it is associated with about 4100 molecules of water and about 520 molecules of salt. At very low resolution, the enzyme particle appears to have a compact protein core and protruding protein parts in interaction with the water and salt components, structural features that are not observed in non-halophilic mitochondrial malate dehydrogenase. The above conclusions were drawn from the analysis of neutron scattering and ultracentrifugation data, and the complementarity of these approaches is discussed extensively. 24 refs.; 7 figs.; 4 tabs

Verification of Monte Carlo transport codes by activation experiments

Energy Technology Data Exchange (ETDEWEB)

Chetvertkova, Vera

2012-12-18

With the increasing energies and intensities of heavy-ion accelerator facilities, the problem of an excessive activation of the accelerator components caused by beam losses becomes more and more important. Numerical experiments using Monte Carlo transport codes are performed in order to assess the levels of activation. The heavy-ion versions of the codes were released approximately a decade ago, therefore the verification is needed to be sure that they give reasonable results. Present work is focused on obtaining the experimental data on activation of the targets by heavy-ion beams. Several experiments were performed at GSI Helmholtzzentrum fuer Schwerionenforschung. The interaction of nitrogen, argon and uranium beams with aluminum targets, as well as interaction of nitrogen and argon beams with copper targets was studied. After the irradiation of the targets by different ion beams from the SIS18 synchrotron at GSI, the γ-spectroscopy analysis was done: the γ-spectra of the residual activity were measured, the radioactive nuclides were identified, their amount and depth distribution were detected. The obtained experimental results were compared with the results of the Monte Carlo simulations using FLUKA, MARS and SHIELD. The discrepancies and agreements between experiment and simulations are pointed out. The origin of discrepancies is discussed. Obtained results allow for a better verification of the Monte Carlo transport codes, and also provide information for their further development. The necessity of the activation studies for accelerator applications is discussed. The limits of applicability of the heavy-ion beam-loss criteria were studied using the FLUKA code. FLUKA-simulations were done to determine the most preferable from the radiation protection point of view materials for use in accelerator components.

Adsorption of low concentration ceftazidime from aqueous solutions using impregnated activated carbon promoted by Iron, Copper and Aluminum

Energy Technology Data Exchange (ETDEWEB)

Hu, Xiang, E-mail: huxiang@mail.buct.edu.cn [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Research Centre for Environmental Pollution Control and Resource Reuse Engineering of Beijing City, Beijing 100029 (China); Zhang, Hua [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Research Centre for Environmental Pollution Control and Resource Reuse Engineering of Beijing City, Beijing 100029 (China); Sun, Zhirong, E-mail: zrsun@bjut.edu.cn [College of Environmental & Energy Engineering, Beijing University of Technology, Beijing 100124 (China)

2017-01-15

Graphical abstract: The graphic abstract describes the research that we used modified activated carbons impregnated with iron nitrate, copper nitrate and aluminium nitrate to adsorb ceftazidime from aqueous solution. The surface functional groups of the modified activated carbons were different, and thus resulted in the big difference in the adsorption performance of the modified activated carbons. The theory and the experiments both showed the preferable adsorption of ceftazidime could be achieved on modified activated carbons. - Highlights: • Three modified activated carbons were prepared by impregnating metal nitrate. • Characteristics of the modified activated carbons were analyzed. • Adsorption capacity of ceftazidime on modified activated carbons was improved. • The adsorption behavior of ceftazidime on modified activated carbons were revealed. • The nature of ceftazidime adsorption on modified activated carbons was elucidated. - Abstract: In this paper, three impregnated activated carbon IAC (AC-Cu, AC-Fe, and AC-Al) promoted by Iron, Copper and Aluminum were used for adsorption of ceftazidime. Iron(III), Copper(II) and Aluminum(III) nitrate were used as an impregnant. The IACs were characterized by scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS).The influence of factors, such as ion strength, pH, temperature, initial concentration, and concentration of natural organic matter organic matter on the adsorption process were studied. The adsorption kinetics and isotherms of ceftazidime were studied for the three IACs. The results showed that the adsorption was accurately represented by pseudo-second order model. Under different temperature, the maximum adsorption quantity of ceftazidime on AC-Cu calculated by pseudo-second order kinetic model were 200.0 mg g{sup −1} (298 K), 196.1 mg g{sup −1} (303 K) and 185.2 mg g

Adsorption of low concentration ceftazidime from aqueous solutions using impregnated activated carbon promoted by Iron, Copper and Aluminum

International Nuclear Information System (INIS)

Hu, Xiang; Zhang, Hua; Sun, Zhirong

2017-01-01

Graphical abstract: The graphic abstract describes the research that we used modified activated carbons impregnated with iron nitrate, copper nitrate and aluminium nitrate to adsorb ceftazidime from aqueous solution. The surface functional groups of the modified activated carbons were different, and thus resulted in the big difference in the adsorption performance of the modified activated carbons. The theory and the experiments both showed the preferable adsorption of ceftazidime could be achieved on modified activated carbons. - Highlights: • Three modified activated carbons were prepared by impregnating metal nitrate. • Characteristics of the modified activated carbons were analyzed. • Adsorption capacity of ceftazidime on modified activated carbons was improved. • The adsorption behavior of ceftazidime on modified activated carbons were revealed. • The nature of ceftazidime adsorption on modified activated carbons was elucidated. - Abstract: In this paper, three impregnated activated carbon IAC (AC-Cu, AC-Fe, and AC-Al) promoted by Iron, Copper and Aluminum were used for adsorption of ceftazidime. Iron(III), Copper(II) and Aluminum(III) nitrate were used as an impregnant. The IACs were characterized by scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS).The influence of factors, such as ion strength, pH, temperature, initial concentration, and concentration of natural organic matter organic matter on the adsorption process were studied. The adsorption kinetics and isotherms of ceftazidime were studied for the three IACs. The results showed that the adsorption was accurately represented by pseudo-second order model. Under different temperature, the maximum adsorption quantity of ceftazidime on AC-Cu calculated by pseudo-second order kinetic model were 200.0 mg g"−"1 (298 K), 196.1 mg g"−"1 (303 K) and 185.2 mg g"−"1 (308 K

Pengaruh Pengasapan (Thermal Fogging Insektisida Piretroid (Malation 95% Terhadap Nyamuk Aedes aegypti dan Culex quinquefasciatus di Pemukiman

Directory of Open Access Journals (Sweden)

Hasan Boesri

2009-12-01

Full Text Available The evaluation of piretroid insecticide (active ingredient Malation 95% was con-ducted in Sub district Tengarang, Semarang Segency, Central Java Province. The insecti-cide was applied using thermal fogging method for dosages of 125, 250, 375, 500 and 625 ml/ha (diluted in diesel to 10 litters. The evaluation of the efficacy was conducted against two mosquito species, Aedes aegypti (the main dengue haemorrhagic fever and Culex quinquefasciatus (the urban lymphatic fil-ariasis vector. Result of the evaluation was revealed that dosages of 500 and 625 ml/ha were effective against both tested mosquito species indoor and outdoor.

Lithium-aluminum-magnesium electrode composition

Science.gov (United States)

Melendres, Carlos A.; Siegel, Stanley

1978-01-01

A negative electrode composition is presented for use in a secondary, high-temperature electrochemical cell. The cell also includes a molten salt electrolyte of alkali metal halides or alkaline earth metal halides and a positive electrode including a chalcogen or a metal chalcogenide as the active electrode material. The negative electrode composition includes up to 50 atom percent lithium as the active electrode constituent and a magnesium-aluminum alloy as a structural matrix. Various binary and ternary intermetallic phases of lithium, magnesium, and aluminum are formed but the electrode composition in both its charged and discharged state remains substantially free of the alpha lithium-aluminum phase and exhibits good structural integrity.

The aluminum-air battery for electric vehicles - An update

Science.gov (United States)

1980-11-01

The development of aluminum-air batteries as mechanically rechargeable power sources to be used in electric vehicles is discussed. The chemistry of the aluminum-air battery, which has a potential for providing the range, acceleration and rapid refueling capability of contemporary automobiles and is based on the reaction of aluminum metal with atmospheric oxygen in the presence of an aqueous sodium hydroxide/sodium aluminate electrolyte, is examined, and it is pointed out that the electric vehicle would be practically emissionless. The battery development program at the Lawrence Livermore National Laboratory, which includes evaluations of electrochemical and chemical phenomena, studies of the economics and energy balance of a transportation system based on aluminum, and power cell design and performance analysis, is presented. It is concluded that although difficult problems must be overcome before the technical and economic feasibility of aluminum-air batteries for electric vehicles can be established, projections indicate that the aluminum-air vehicle is potentially competitive with internal combustion vehicles powered by synthetic liquid fuels.

Adsorption of low concentration ceftazidime from aqueous solutions using impregnated activated carbon promoted by Iron, Copper and Aluminum

Science.gov (United States)

Hu, Xiang; Zhang, Hua; Sun, Zhirong

2017-01-01

In this paper, three impregnated activated carbon IAC (AC-Cu, AC-Fe, and AC-Al) promoted by Iron, Copper and Aluminum were used for adsorption of ceftazidime. Iron(III), Copper(II) and Aluminum(III) nitrate were used as an impregnant. The IACs were characterized by scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS).The influence of factors, such as ion strength, pH, temperature, initial concentration, and concentration of natural organic matter organic matter on the adsorption process were studied. The adsorption kinetics and isotherms of ceftazidime were studied for the three IACs. The results showed that the adsorption was accurately represented by pseudo-second order model. Under different temperature, the maximum adsorption quantity of ceftazidime on AC-Cu calculated by pseudo-second order kinetic model were 200.0 mg g-1 (298 K), 196.1 mg g-1 (303 K) and 185.2 mg g-1 (308 K). It was much higher than that of AC-Fe and AC-Al. And the process was controlled by both film diffusion and intra particle mass transport. The results also showed that, the Freundlich and Temkin isotherm fit the adsorption well.

Lithium-aluminum-iron electrode composition

Science.gov (United States)

Kaun, Thomas D.

1979-01-01

A negative electrode composition is presented for use in a secondary electrochemical cell. The cell also includes an electrolyte with lithium ions such as a molten salt of alkali metal halides or alkaline earth metal halides that can be used in high-temperature cells. The cell's positive electrode contains a a chalcogen or a metal chalcogenide as the active electrode material. The negative electrode composition includes up to 50 atom percent lithium as the active electrode constituent in an alloy of aluminum-iron. Various binary and ternary intermetallic phases of lithium, aluminum and iron are formed. The lithium within the intermetallic phase of Al.sub.5 Fe.sub.2 exhibits increased activity over that of lithium within a lithium-aluminum alloy to provide an increased cell potential of up to about 0.25 volt.

The contribution of stored malate and citrate to the substrate requirements of metabolism of ripening peach (Prunus persica L. Batsch) flesh is negligible. Implications for the occurrence of phosphoenolpyruvate carboxykinase and gluconeogenesis.

Science.gov (United States)

Famiani, Franco; Farinelli, Daniela; Moscatello, Stefano; Battistelli, Alberto; Leegood, Richard C; Walker, Robert P

2016-04-01

The first aim of this study was to determine the contribution of stored malate and citrate to the substrate requirements of metabolism in the ripening flesh of the peach (Prunus persica L. Batsch) cultivar Adriatica. In the flesh, stored malate accumulated before ripening could contribute little or nothing to the net substrate requirements of metabolism. This was because there was synthesis and not dissimilation of malate throughout ripening. Stored citrate could potentially contribute a very small amount (about 5.8%) of the substrate required by metabolism when the whole ripening period was considered, and a maximum of about 7.5% over the latter part of ripening. The second aim of this study was to investigate why phosphoenolpyruvate carboxykinase (PEPCK) an enzyme utilised in gluconeogenesis from malate and citrate is present in peach flesh. The occurrence and localisation of enzymes utilised in the metabolism of malate, citrate and amino acids were determined in peach flesh throughout its development. Phosphoenolpyruvate carboxylase (essential for the synthesis of malate and citrate) was present in the same cells and at the same time as PEPCK and NADP-malic enzyme (both utilised in the dissimilation of malate and citrate). A hypothesis is presented to explain the presence of these enzymes and to account for the likely occurrence of gluconeogenesis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Pre-ischemic mitochondrial substrate constraint by inhibition of malate-aspartate shuttle preserves mitochondrial function after ischemia-reperfusion

DEFF Research Database (Denmark)

Jespersen, Nichlas Riise; Yokota, Takashi; Støttrup, Nicolaj Brejnholt

2017-01-01

KEY POINTS: Pre-ischaemic administration of aminooxiacetate (AOA), an inhibitor of the malate-aspartate shuttle (MAS), provides cardioprotection against ischaemia-reperfusion injury. The underlying mechanism remains unknown. We examined whether transient inhibition of the MAS during ischaemia......, but not IPC, reduced the myocardial interstitial concentration of tricarboxylic acid cycle intermediates at the onset of reperfusion. The results obtained in the present study demonstrate that metabolic regulation by inhibition of the MAS at the onset of reperfusion may be beneficial for the preservation...... of mitochondrial function during late reperfusion in an IR-injured heart. ABSTRACT: Mitochondrial dysfunction plays a central role in ischaemia-reperfusion (IR) injury. Pre-ischaemic administration of aminooxyacetate (AOA), an inhibitor of the malate-aspartate shuttle (MAS), provides cardioprotection against IR...

Oxidation of nano-sized aluminum powders

International Nuclear Information System (INIS)

Vorozhtsov, A.B.; Lerner, M.; Rodkevich, N.; Nie, H.; Abraham, A.; Schoenitz, M.; Dreizin, E.L.

2016-01-01

Highlights: • Weight gain measured in TG oxidation experiments was split between particles of different sizes. • Reaction kinetics obtained by isoconversion explicitly accounting for the effect of size distribution. • Activation energy is obtained as a function of oxide thickness for growth of amorphous alumina. • Oxidation mechanism for nanopowders remains the same as for coarser aluminum powders. - Abstract: Oxidation of aluminum nanopowders obtained by electro-exploded wires is studied. Particle size distributions are obtained from transmission electron microscopy (TEM) images. Thermo-gravimetric (TG) experiments are complemented by TEM and XRD studies of partially oxidized particles. Qualitatively, oxidation follows the mechanism developed for coarser aluminum powder and resulting in formation of hollow oxide shells. Sintering of particles is also observed. The TG results are processed to account explicitly for the particle size distribution and spherical shapes, so that oxidation of particles of different sizes is characterized. The apparent activation energy is obtained as a function of the reaction progress using model-free isoconversion processing of experimental data. A complete phenomenological oxidation model is then proposed assuming a spherically symmetric geometry. The oxidation kinetics of aluminum powder is shown to be unaffected by particle sizes reduced down to tens of nm. The apparent activation energy describing growth of amorphous alumina is increasing at the very early stages of oxidation. The higher activation energy is likely associated with an increasing homogeneity in the growing amorphous oxide layer, initially containing multiple defects and imperfections. The trends describing changes in both activation energy and pre-exponent of the growing amorphous oxide are useful for predicting ignition delays of aluminum particles. The kinetic trends describing activation energies and pre-exponents in a broader range of the oxide

Hydrolysis of aluminum dross material to achieve zero hazardous waste

International Nuclear Information System (INIS)

David, E.; Kopac, J.

2012-01-01

Highlights: ► The hydrolysis of aluminum dross in tap water generates pure hydrogen. ► Aluminum particles from dross are activated by mechanically milling technique. ► The process is completely greenhouse gases free and is cleanly to environment. ► Hydrolysis process leads to recycling of waste aluminum by hydrogen production. - Abstract: A simple method with high efficiency for generating high pure hydrogen by hydrolysis in tap water of highly activated aluminum dross is established. Aluminum dross is activated by mechanically milling to particles of about 45 μm. This leads to removal of surface layer of the aluminum particles and creation of a fresh chemically active metal surface. In contact with water the hydrolysis reaction takes place and hydrogen is released. In this process a Zero Waste concept is achieved because the other product of reaction is aluminum oxide hydroxide (AlOOH), which is nature-friendly and can be used to make high quality refractory or calcium aluminate cement. For comparison we also used pure aluminum powder and alkaline tap water solution (NaOH, KOH) at a ratio similar to that of aluminum dross content. The rates of hydrogen generated in hydrolysis reaction of pure aluminum and aluminum dross have been found to be similar. As a result of the experimental setup, a hydrogen generator was designed and assembled. Hydrogen volume generated by hydrolysis reaction was measured. The experimental results obtained reveal that aluminum dross could be economically recycled by hydrolysis process with achieving zero hazardous aluminum dross waste and hydrogen generation.

Alternative oxidase pathway optimizes photosynthesis during osmotic and temperature stress by regulating cellular ROS, malate valve and antioxidative systems

Directory of Open Access Journals (Sweden)

DINAKAR eCHALLABATHULA

2016-02-01

Full Text Available The present study reveals the importance of alternative oxidase (AOX pathway in optimizing photosynthesis under osmotic and temperature stress conditions in the mesophyll protoplasts of Pisum sativum. The responses of photosynthesis and respiration were monitored at saturating light intensity of 1000 µmoles m-2 s-1 at 25 oC under a range of sorbitol concentrations from 0.4 M to 1.0M to induce hyper-osmotic stress and by varying the temperature of the thermo-jacketed pre-incubation chamber from 25 oC to 10 oC to impose sub-optimal temperature stress. Compared to controls (0.4 M sorbitol and 25 OC, the mesophyll protoplasts showed remarkable decrease in NaHCO3-dependent O2 evolution (indicator of photosynthetic carbon assimilation, under both hyper-osmotic (1.0 M sorbitol and sub-optimal temperature stress conditions (10 OC, while the decrease in rates of respiratory O2 uptake were marginal. The capacity of AOX pathway increased significantly in parallel to increase in intracellular pyruvate and reactive oxygen species (ROS levels under both hyper-osmotic stress and sub-optimal temperature stress under the background of saturating light. The ratio of redox couple (Malate/OAA related to malate valve increased in contrast to the ratio of redox couple (GSH/GSSG related to antioxidative system during hyper-osmotic stress. Nevertheless, the ratio of GSH/GSSG decreased in the presence of sub-optimal temperature, while the ratio of Malate/OAA showed no visible changes. Also, the redox ratios of pyridine nucleotides increased under hyper-osmotic (NADH/NAD and sub-optimal temperature (NADPH/NADP stresses, respectively. However, upon restriction of AOX pathway by using salicylhydroxamic acid (SHAM, the observed changes in NaHCO3 dependent O2 evolution, cellular ROS, redox ratios of Malate/OAA, NAD(PH/NAD(P and GSH/GSSG were further aggravated under stress conditions with concomitant modulations in NADP-MDH and antioxidant enzymes. Taken together, the

Ab Initio Calculations of Transport in Titanium and Aluminum Mixtures

Science.gov (United States)

Walker, Nicholas; Novak, Brian; Tam, Ka Ming; Moldovan, Dorel; Jarrell, Mark

In classical molecular dynamics simulations, the self-diffusion and shear viscosity of titanium about the melting point have fallen within the ranges provided by experimental data. However, the experimental data is difficult to collect and has been rather scattered, making it of limited value for the validation of these calculations. By using ab initio molecular dynamics simulations within the density functional theory framework, the classical molecular dynamics data can be validated. The dynamical data from the ab initio molecular dynamics can also be used to calculate new potentials for use in classical molecular dynamics, allowing for more accurate classical dynamics simulations for the liquid phase. For metallic materials such as titanium and aluminum alloys, these calculations are very valuable due to an increasing demand for the knowledge of their thermophysical properties that drive the development of new materials. For example, alongside knowledge of the surface tension, viscosity is an important input for modeling the additive manufacturing process at the continuum level. We are developing calculations of the viscosity along with the self-diffusion for aluminum, titanium, and titanium-aluminum alloys with ab initio molecular dynamics. Supported by the National Science Foundation through cooperative agreement OIA-1541079 and the Louisiana Board of Regents.

Aluminum-carbon composite electrode

Science.gov (United States)

Farahmandi, C. Joseph; Dispennette, John M.

1998-07-07

A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.

Improved age-diffusion model for low-energy electron transport in solids. II. Application to secondary emission from aluminum

International Nuclear Information System (INIS)

Dubus, A.; Devooght, J.; Dehaes, J.C.

1987-01-01

The ''improved age-diffusion'' model for secondary-electron transport is applied to aluminum. Electron cross sections for inelastic collisions with the free-electron gas using the Lindhard dielectric function and for elastic collisions with the randomly distributed ionic cores are used in the calculations. The most important characteristics of backward secondary-electron emission induced by low-energy electrons on polycrystalline Al targets are calculated and compared to experimental results and to Monte Carlo calculations. The model appears to predict the electronic yield, the energy spectra, and the spatial dependence of secondary emission with reasonable accuracy

NCBI nr-aa BLAST: CBRC-CBRI-04-0044 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-CBRI-04-0044 ref|NP_595047.1| malate permease [Schizosaccharomyces pombe 972h-...] ref|NP_595048.1| malate permease [Schizosaccharomyces pombe 972h-] ref|NP_595049.1| malate permease [Schizosaccharomyce...s pombe 972h-] ref|NP_595050.1| malate permease [Schizosaccharomyces pombe 972h-] emb|CAC36913....1| membrane transporter (predicted) [Schizosaccharomyces pombe] emb|CAC36914.1| m...embrane transporter (predicted) [Schizosaccharomyces pombe] emb|CAC36915.1| membrane transporter (predicted) [Schizosaccharomyce

Adsorption of Trametes versicolor laccase to soil iron and aluminum minerals: enzyme activity, kinetics and stability studies.

Science.gov (United States)

Wu, Yue; Jiang, Ying; Jiao, Jiaguo; Liu, Manqiang; Hu, Feng; Griffiths, Bryan S; Li, Huixin

2014-02-01

Laccases play an important role in the degradation of soil phenol or phenol-like substance and can be potentially used in soil remediation through immobilization. Iron and aluminum minerals can adsorb extracellular enzymes in soil environment. In the present study, we investigated the adsorptive interaction of laccase, from the white-rot fungus Trametes versicolor, with soil iron and aluminum minerals and characterized the properties of the enzyme after adsorption to minerals. Results showed that both soil iron and aluminum minerals adsorbed great amount of laccase, independent of the mineral specific surface areas. Adsorbed laccases retained 26-64% of the activity of the free enzyme. Compared to the free laccase, all adsorbed laccases showed higher Km values and lower Vmax values, indicating a reduced enzyme-substrate affinity and a lower rate of substrate conversion in reactions catalyzed by the adsorbed laccase. Adsorbed laccases exhibited increased catalytic activities compared to the free laccase at low pH, implying the suitable application of iron and aluminum mineral-adsorbed T. versicolor laccase in soil bioremediation, especially in acid soils. In terms of the thermal profiles, adsorbed laccases showed decreased thermal stability and higher temperature sensitivity relative to the free laccase. Moreover, adsorption improved the resistance of laccase to proteolysis and extended the lifespan of laccase. Our results implied that adsorbed T. versicolor laccase on soil iron and aluminum minerals had promising potential in soil remediation. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Development of boronated aluminum alloy for basket of cask for nuclear spent fuel

International Nuclear Information System (INIS)

Sakaguchi, Y.; Saida, T.; Matsuoka, T.; Kuri, S.; Ohsono, K.; Hode, S.

2001-01-01

Since 1980's Mitsubishi Heavy Industries, Ltd. (MHI) has been contributing to develop metal cask technologies for utilities and competent authorities in Japan, and have established transport and storage cask design ''MSF series'' which realizes higher payload and reliability for long term storage. MSF series transport and storage cask uses new-developed boronated aluminum as basket material. This boronated aluminum has been developed to improve characteristics of material. To achieve this object, powder metallurgy method has been adopted for manufacturing boronated material. It is well known that this method provides excellent characteristics for the material and this boronated aluminum alloy has obtained excellent both mechanical and neutron absorbing characteristics. In addition, in order to maintain material properties for long-term use this boronated material is not strengthened by aging treatment. This paper summarizes an outline of the boronated aluminum alloy for basket assemblies by powder metallurgy. (author)

Systematic replacement of lysine with glutamine and alanine in Escherichia coli malate synthase G: effect on crystallization

International Nuclear Information System (INIS)

Anstrom, David M.; Colip, Leslie; Moshofsky, Brian; Hatcher, Eric; Remington, S. James

2005-01-01

Alanine and glutamine mutations were made to the same 15 lysine positions on the surface of E. coli malate synthase G and the impact on crystallization observed. The results support lysine replacement for improvement of crystallization and provide insight into site selection and type of amino-acid replacement. Two proposals recommend substitution of surface lysine residues as a means to improve the quality of protein crystals. In proposal I, substitution of lysine by alanine has been suggested to improve crystallization by reducing the entropic cost of ordering flexible side chains at crystal contacts. In proposal II, substitution of lysine by residues more commonly found in crystal contacts, such as glutamine, has been proposed to improve crystallization. 15 lysine residues on the surface of Escherichia coli malate synthase G, distributed over a variety of secondary structures, were individually mutated to both alanine and glutamine. For 28 variants, detailed studies of the effect on enzymatic activity and crystallization were conducted. This has permitted direct comparison of the relative effects of the two types of mutations. While none of the variants produced crystals suitable for X-ray structural determination, small crystals were obtained in a wide variety of conditions, in support of the general approach. Glutamine substitutions were found to be more effective than alanine in producing crystals, in support of proposal II. Secondary structure at the site of mutation does not appear to play a major role in determining the rate of success

[Microbiological corrosion of aluminum alloys].

Science.gov (United States)

Smirnov, V F; Belov, D V; Sokolova, T N; Kuzina, O V; Kartashov, V R

2008-01-01

Biological corrosion of ADO quality aluminum and aluminum-based construction materials (alloys V65, D16, and D16T) was studied. Thirteen microscopic fungus species and six bacterial species proved to be able to attack aluminum and its alloys. It was found that biocorrosion of metals by microscopic fungi and bacteria was mediated by certain exometabolites. Experiments on biocorrosion of the materials by the microscopic fungus Alternaria alternata, the most active biodegrader, demonstrated that the micromycete attack started with the appearance of exudate with pH 8-9 on end faces of the samples.

Action of diclofenac on kidney mitochondria and cells

International Nuclear Information System (INIS)

Ng, Lin Eng; Vincent, Annette S.; Halliwell, Barry; Wong, Kim Ping

2006-01-01

The mitochondrial membrane potential measured in isolated rat kidney mitochondria and in digitonin-permeabilized MDCK type II cells pre-energized with succinate, glutamate, and/or malate was reduced by micromolar diclofenac dose-dependently. However, ATP biosynthesis from glutamate/malate was significantly more compromised compared to that from succinate. Inhibition of the malate-aspartate shuttle by diclofenac with a resultant decrease in the ability of mitochondria to generate NAD(P)H was demonstrated. Diclofenac however had no effect on the activities of NADH dehydrogenase, glutamate dehydrogenase, and malate dehydrogenase. In conclusion, decreased NAD(P)H production due to an inhibition of the entry of malate and glutamate via the malate-aspartate shuttle explained the more pronounced decreased rate of ATP biosynthesis from glutamate and malate by diclofenac. This drug, therefore affects the bioavailability of two major respiratory complex I substrates which would normally contribute substantially to supplying the reducing equivalents for mitochondrial electron transport for generation of ATP in the renal cell

Effects of cations on hormone transport in primary roots of Zea mays

Science.gov (United States)

Hasenstein, K. H.; Evans, M. L.

1988-01-01

We examined the influence of aluminum and calcium (and certain other cations) on hormone transport in corn roots. When aluminum was applied unilaterally to the caps of 15 mm apical root sections the roots curved strongly away from the aluminum. When aluminum was applied unilaterally to the cap and 3H-indole-3-acetic acid was applied to the basal cut surface twice as much radioactivity (assumed to be IAA) accumulated on the concave side of the curved root as on the convex side. Auxin transport in the apical region of intact roots was preferentially basipetal, with a polarity (basipetal transport divided by acropetal transport) of 6.3. In decapped 5 mm apical root segments, auxin transport was acropetally polar (polarity = 0.63). Application of aluminum to the root cap strongly promoted acropetal transport of auxin reducing polarity from 6.3 to 2.1. Application of calcium to the root cap enhanced basipetal movement of auxin, increasing polarity from 6.3 to 7.6. Application of the calcium chelator, ethylene-glycol-bis-(beta-aminoethylether)-N,N,N',N'-tetraacetic acid, greatly decreased basipetal auxin movement, reducing polarity from 6.3 to 3.7. Transport of label after application of tritiated abscisic acid showed no polarity and was not affected by calcium or aluminum. The results indicate that the root cap is particularly important in maintaining basipetal polarity of auxin transport in primary roots of corn. The induction of root curvature by unilateral application of aluminum or calcium to root caps is likely to result from localized effects of these ions on auxin transport. The findings are discussed relative to the possible role of calcium redistribution in the gravitropic curvature of roots and the possibility of calmodulin involvement in the action of calcium and aluminum on auxin transport.

Aluminum as anode for energy storage and conversion: a review

Science.gov (United States)

Li, Qingfeng; Bjerrum, Niels J.

Aluminum has long attracted attention as a potential battery anode because of its high theoretical voltage and specific energy. The protective oxide layer on the aluminum surface is however detrimental to the battery performance, contributing to failure to achieve the reversible potential and causing the delayed activation of the anode. By developing aluminum alloys as anodes and solution additives to electrolytes, a variety of aluminum batteries have been extensively investigated for various applications. From molten salt and other non-aqueous electrolytes, aluminum can be electrodeposited and therefore be suitable for developing rechargable batteries. Considerable efforts have been made to develop secondary aluminum batteries of high power density. In the present paper, these research activities are reviewed, including aqueous electrolyte primary batteries, aluminum-air batteries and molten salt secondary batteries.

Precipitation and Deposition of Aluminum-Containing Phases in Tank Wastes

International Nuclear Information System (INIS)

Dabbs, Daniel M.; Aksay, Ilhan A.

2005-01-01

Aluminum-containing phases compose the bulk of solids precipitating during the processing of radioactive tank wastes. Processes designed to minimize the volume of high-level waste through conversion to glassy phases require transporting waste solutions near-saturated with aluminum-containing species from holding tank to processing center. The uncontrolled precipitation within transfer lines results in clogged pipes and lines and fouled ion exchangers, with the potential to shut down processing operations

Oxidation of zirconium-aluminum alloys

International Nuclear Information System (INIS)

Cox, B.

1967-10-01

Examination of the processes occurring during the oxidation of Zr-1% A1, Zr-3% A1, and Zr-1.5% A1-0.5% Mo alloys has shown that in steam rapid oxidation occurs predominantly around the Zr 3 A1 particles, which at low temperatures appear to be relatively unattacked. The unoxidised particles become incorporated in the oxide, and become fully oxidised as the film thickens. This rapid localised oxidation is preceded by a short period of uniform film growth, during which the oxide film thickness does not exceed ∼200A-o. Thus the high oxidation rates can probably be ascribed to aluminum in solution in the zirconium matrix, although its precise mode of operation has not been determined. Once the solubility limit of aluminum is exceeded, the size, distribution and number of intermetallic particles affects the oxidation rate merely by altering the distribution of regions of metal giving high oxidation rates. The controlling process during the early stages of oxidation is electron transport and not ionic transport. Thus, the aluminum in the oxide film is presumably increasing the ionic conductivity more than the electronic. The oxidation rates in atmospheric pressure steam are very high and their irregular temperature dependence suggests that the oxidation rate will be pressure dependent. This was confirmed, in part, by a comparison with oxidation in moist air. It was found that the rate of development of white oxide around intermetallic particles was considerably reduced by the decrease in the partial pressure of H 2 O; the incubation period was not much different, however. (author)

Active Transportation Surveillance - United States, 1999-2012.

Science.gov (United States)

Whitfield, Geoffrey P; Paul, Prabasaj; Wendel, Arthur M

2015-08-28

Physical activity is a health-enhancing behavior, and most U.S. adults do not meet the 2008 Physical Activity Guidelines for Americans. Active transportation, such as by walking or bicycling, is one way that persons can be physically active. No comprehensive, multiyear assessments of active transportation surveillance in the United States have been conducted. 1999-2012. Five surveillance systems assess one or more components of active transportation. The American Community Survey and the National Household Travel Survey (NHTS) both assess the mode of transportation to work in the past week. From these systems, the proportion of respondents who reported walking or bicycling to work can be calculated. NHTS and the American Time Use Survey include 1-day assessments of trips or activities. With that information, the proportion of respondents who report any walking or bicycling for transportation can be calculated. The National Health and Nutrition Examination Survey and the National Health Interview Survey both assess recent (i.e., in the past week or past month) habitual physical activity behaviors, including those performed during active travel. From these systems, the proportion of respondents who report any recent habitual active transportation can be calculated. The prevalence of active transportation as the primary commute mode to work in the past week ranged from 2.6% to 3.4%. The 1-day assessment indicated that the prevalence of any active transportation ranged from 10.5% to 18.5%. The prevalence of any habitual active transportation ranged from 23.9% to 31.4%. No consistent trends in active transportation across time periods and surveillance systems were identified. Among systems, active transportation was usually more common among men, younger respondents, and minority racial/ethnic groups. Among education groups, the highest prevalence of active transportation was usually among the least or most educated groups, and active transportation tended to be more

Crystal structures of a halophilic archaeal malate synthase from Haloferax volcanii and comparisons with isoforms A and G

Science.gov (United States)

2011-01-01

Background Malate synthase, one of the two enzymes unique to the glyoxylate cycle, is found in all three domains of life, and is crucial to the utilization of two-carbon compounds for net biosynthetic pathways such as gluconeogenesis. In addition to the main isoforms A and G, so named because of their differential expression in E. coli grown on either acetate or glycolate respectively, a third distinct isoform has been identified. These three isoforms differ considerably in size and sequence conservation. The A isoform (MSA) comprises ~530 residues, the G isoform (MSG) is ~730 residues, and this third isoform (MSH-halophilic) is ~430 residues in length. Both isoforms A and G have been structurally characterized in detail, but no structures have been reported for the H isoform which has been found thus far only in members of the halophilic Archaea. Results We have solved the structure of a malate synthase H (MSH) isoform member from Haloferax volcanii in complex with glyoxylate at 2.51 Å resolution, and also as a ternary complex with acetyl-coenzyme A and pyruvate at 1.95 Å. Like the A and G isoforms, MSH is based on a β8/α8 (TIM) barrel. Unlike previously solved malate synthase structures which are all monomeric, this enzyme is found in the native state as a trimer/hexamer equilibrium. Compared to isoforms A and G, MSH displays deletion of an N-terminal domain and a smaller deletion at the C-terminus. The MSH active site is closely superimposable with those of MSA and MSG, with the ternary complex indicating a nucleophilic attack on pyruvate by the enolate intermediate of acetyl-coenzyme A. Conclusions The reported structures of MSH from Haloferax volcanii allow a detailed analysis and comparison with previously solved structures of isoforms A and G. These structural comparisons provide insight into evolutionary relationships among these isoforms, and also indicate that despite the size and sequence variation, and the truncated C-terminal domain of the H

HvALMT1 from barley is involved in the transport of organic anions.

Science.gov (United States)

Gruber, Benjamin D; Ryan, Peter R; Richardson, Alan E; Tyerman, Stephen D; Ramesh, Sunita; Hebb, Diane M; Howitt, Susan M; Delhaize, Emmanuel

2010-03-01

Members of the ALMT gene family contribute to the Al(3+) resistance of several plant species by facilitating malate efflux from root cells. The first member of this family to be cloned and characterized, TaALMT1, is responsible for most of the natural variation of Al(3+) resistance in wheat. The current study describes the isolation and characterization of HvALMT1, the barley gene with the greatest sequence similarity to TaALMT1. HvALMT1 is located on chromosome 2H which has not been associated with Al(3+) resistance in barley. The relatively low levels of HvALMT1 expression detected in root and shoot tissues were independent of external aluminium or phosphorus supply. Transgenic barley plants transformed with the HvALMT1 promoter fused to the green fluorescent protein (GFP) indicated that expression of HvALMT1 was relatively high in stomatal guard cells and in root tissues containing expanding cells. GFP fused to the C-terminus of the full HvALMT1 protein localized to the plasma membrane and motile vesicles within the cytoplasm. HvALMT1 conferred both inward and outward currents when expressed in Xenopus laevis oocytes that were bathed in a range of anions including malate. Both malate uptake and efflux were confirmed in oocyte assays using [(14)C]malate as a radiotracer. It is suggested that HvALMT1 functions as an anion channel to facilitate organic anion transport in stomatal function and expanding cells.

Short-lived long non-coding RNAs as surrogate indicators for chemical exposure and LINC00152 and MALAT1 modulate their neighboring genes.

Directory of Open Access Journals (Sweden)

Hidenori Tani

Full Text Available Whole transcriptome analyses have revealed a large number of novel long non-coding RNAs (lncRNAs. Although accumulating evidence demonstrates that lncRNAs play important roles in regulating gene expression, the detailed mechanisms of action of most lncRNAs remain unclear. We previously reported that a novel class of lncRNAs with a short half-life (t1/2 < 4 h in HeLa cells, termed short-lived non-coding transcripts (SLiTs, are closely associated with physiological and pathological functions. In this study, we focused on 26 SLiTs and nuclear-enriched abundant lncRNA, MALAT1(t1/2 of 7.6 h in HeLa cells in neural stem cells (NSCs derived from human induced pluripotent stem cells, and identified four SLiTs (TUG1, GAS5, FAM222-AS1, and SNHG15 that were affected by the following typical chemical stresses (oxidative stress, heavy metal stress and protein synthesis stress. We also found the expression levels of LINC00152 (t1/2 of 2.1 h in NSCs, MALAT1 (t1/2 of 1.8 h in NSCs, and their neighboring genes were elevated proportionally to the chemical doses. Moreover, we confirmed that the overexpression of LINC00152 or MALAT1 upregulated the expressions of their neighboring genes even in the absence of chemical stress. These results reveal that LINC00152 and MALAT1 modulate their neighboring genes, and thus provide a deeper understanding of the functions of lncRNAs.

In-situ Electrodeposition of Highly Active Silver Catalyst on Carbon Fiber Papers as Binder Free Cathodes for Aluminum-air Battery

OpenAIRE

Hong, Qingshui; Lu, Huimin

2017-01-01

Carbon fiber papers supported Ag catalysts (Ag/CFP) with different coverage of electro-active site are prepared by electrochemical deposition and used as binder free cathodes in primary aluminum-air (Al-air) battery. Scanning Electron Microscopy and X-ray Diffraction studies are carried out to characterize the as-prepared Ag/CFP air cathodes. Oxygen reduction reaction (ORR) activities on these air cathodes in alkaline solutions are systematic studied. A newly designed aluminum-air cell is use...

Updated Life-Cycle Assessment of Aluminum Production and Semi-fabrication for the GREET Model

Energy Technology Data Exchange (ETDEWEB)

Dai, Qiang [Argonne National Lab. (ANL), Argonne, IL (United States); Kelly, Jarod C. [Argonne National Lab. (ANL), Argonne, IL (United States); Burnham, Andrew [Argonne National Lab. (ANL), Argonne, IL (United States); Elgowainy, Amgad [Argonne National Lab. (ANL), Argonne, IL (United States)

2015-09-01

This report serves as an update for the life-cycle analysis (LCA) of aluminum production based on the most recent data representing the state-of-the-art of the industry in North America. The 2013 Aluminum Association (AA) LCA report on the environmental footprint of semifinished aluminum products in North America provides the basis for the update (The Aluminum Association, 2013). The scope of this study covers primary aluminum production, secondary aluminum production, as well as aluminum semi-fabrication processes including hot rolling, cold rolling, extrusion and shape casting. This report focuses on energy consumptions, material inputs and criteria air pollutant emissions for each process from the cradle-to-gate of aluminum, which starts from bauxite extraction, and ends with manufacturing of semi-fabricated aluminum products. The life-cycle inventory (LCI) tables compiled are to be incorporated into the vehicle cycle model of Argonne National Laboratory’s Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model for the release of its 2015 version.

ALUMINUM CHLORIDE EFFECT ON Ca2+,Mg(2+)-ATPase ACTIVITY AND DYNAMIC PARAMETERS OF SKELETAL MUSCLE CONTRACTION.

Science.gov (United States)

Nozdrenko, D M; Abramchuk, O M; Soroca, V M; Miroshnichenko, N S

2015-01-01

We studied enzymatic activity and measured strain-gauge contraction properties of the frog Rana temporaria m. tibialis anterior muscle fascicles during the action of aluminum chloride solution. It was shown that AlCl3 solutions did not affect the dynamic properties of skeletal muscle preparation in concentrations less than 10(-4) M Increasing the concentration of AlCl3 to 10(-2) M induce complete inhibition of muscle contraction. A linear correlation between decrease in Ca2+,Mg(2+)-ATPase activity of sarcoplasmic reticulum and the investigated concentrations range of aluminum chloride was observed. The reduction in the dynamic contraction performance and the decrease Ca2+,Mg(2+)-ATPase activity of the sarcoplasmic reticulum under the effect of the investigated AlCl3 solution were minimal in pre-tetanus period of contraction.

Aluminum chloride effect on Ca(2+,Mg(2+-ATPase activity and dynamic parameters of skeletal muscle contraction

Directory of Open Access Journals (Sweden)

D. M. Nozdrenko

2015-10-01

Full Text Available We studied enzymatic activity and measured strain-gauge contraction properties of the frog Rana temporaria m. tibialis anterior muscle fascicles during the action of aluminum chloride solution. It was shown that AlCl3 solutions did not affect the dynamic properties of skeletal muscle preparation in concentrations less than 10-4 M. Increasing the concentration of AlCl3 to 10-2 M induce complete inhibition of muscle contraction. A linear correlation between decrease in Ca2+,Mg2+-ATPase activity of sarcoplasmic reticulum and the investigated concentrations range of aluminum chloride was observed. The reduction in the dynamic contraction performance and the decrease Ca2+,Mg2+-ATPase activity of the sarcoplasmic reticulum under the effect of the investigated AlCl3 solution were minimal in pre-tetanus period of contraction.

Electrometallurgical treatment of aluminum-based fuels

International Nuclear Information System (INIS)

Willit, J. L.

1998-01-01

We have successfully demonstrated aluminum electrorefining from a U-Al-Si alloy that simulates spent aluminum-based reactor fuel. The aluminum product contains less than 200 ppm uranium. All the results obtained have been in agreement with predictions based on equilibrium thermodynamics. We have also demonstrated the need for adequate stirring to achieve a low-uranium product. Most of the other process steps have been demonstrated in other programs. These include uranium electrorefining, transuranic fission product scrubbing, fission product oxidation, and product consolidation by melting. Future work will focus on the extraction of active metal and rare earth fission products by a molten flux salt and scale-up of the aluminum electrorefining

Use of Permanent Magnets in Electromagnetic Facilities for the Treatment of Aluminum Alloys

Science.gov (United States)

Beinerts, Toms; Bojarevičs, Andris; Bucenieks, Imants; Gelfgat, Yuri; Kaldre, Imants

2016-06-01

The possibility of applying the electromagnetic induction pump with permanent magnets for the transportation and stirring of aluminum melts in metallurgical furnaces is investigated. The electromagnetic and hydraulic characteristics of the pump have been investigated theoretically and experimentally with regard to its position in the furnace. The results of the experiments performed with a model in a eutectic InGaSn melt are in good agreement with the calculation data. Extrapolation of the experimental results on the physical characteristics of aluminum melts allows recommending such pumps for contactless control of motion and heat/mass transfer in aluminum melts in different technological processes. A high temperature and the aggressive properties of aluminum alloys make it complicated to use different mechanical devices to solve technological problems, such as liquid metal transportation, dosing, stirring, etc. In this case, any device units or elements moving in or contacting with the melt suffer from corrosion polluting the melt. Therefore, of more importance and topicality are contactless electromagnetic methods for processing of molten metals.

Drosophila melanogaster as a model system of aluminum toxicity and aging.

Science.gov (United States)

Kijak, Ewelina; Rosato, Ezio; Knapczyk, Katarzyna; Pyza, Elżbieta

2014-04-01

The aim of this study was to investigate the toxic effects of aluminum (Al) on the model organism-Drosophila melanogaster. The study is especially concerned with the effects of aluminum on the fruit fly's development, life span, and circadian rhythm in rest and activity. Flies were exposed to aluminum in concentrations from 40 to 280 mg/kg in rearing media or the flies were raised on control medium. Moreover, the life span of insects exposed to aluminum containing 40, 120, or 240 mg/kg of Al in the medium, only during their larval development, during the whole life cycle and only in their adult life was tested. To check if aluminum and aging cause changes in D. melanogaster behavior, the locomotor activity of flies at different ages was recorded. Results showed that aluminum is toxic in concentrations above 160 mg/kg in the rearing medium. Depending on Al concentration and time of exposure, the life span of the flies was shortened. At intermediate concentrations (120 mg/kg), however, Al had a stimulating effect on males increasing their life span and level of locomotor activity. At higher concentration the aluminum exposure increased or decreased the level of locomotor activity of D. melanogaster depending on age of flies. In addition, in the oldest insects reared on aluminum supplemented media and in mid-aged flies reared on the highest concentration of Al the daily rhythm of activity was disrupted. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Achieving Carbon Neutrality in the Global Aluminum Industry

Science.gov (United States)

Das, Subodh

2012-02-01

In the 21st century, sustainability is widely regarded as the new corporate culture, and leading manufacturing companies (Toyota, GE, and Alcoa) and service companies (Google and Federal Express) are striving towards carbon neutrality. The current carbon footprint of the global aluminum industry is estimated at 500 million metric tonnes carbon dioxide equivalent (CO2eq), representing about 1.7% of global emissions from all sources. For the global aluminum industry, carbon neutrality is defined as a state where the total "in-use" CO2eq saved from all products in current use, including incremental process efficiency improvements, recycling, and urban mining activities, equals the CO2eq expended to produce the global output of aluminum. This paper outlines an integrated and quantifiable plan for achieving "carbon neutrality" in the global aluminum industry by advocating five actionable steps: (1) increase use of "green" electrical energy grid by 8%, (2) reduce process energy needs by 16%, (3) deploy 35% of products in "in-use" energy saving applications, (4) divert 6.1 million metric tonnes/year from landfills, and (5) mine 4.5 million metric tonnes/year from aluminum-rich "urban mines." Since it takes 20 times more energy to make aluminum from bauxite ore than to recycle it from scrap, the global aluminum industry could set a reasonable, self-imposed energy/carbon neutrality goal to incrementally increase the supply of recycled aluminum by at least 1.05 metric tonnes for every tonne of incremental production via primary aluminum smelter capacity. Furthermore, the aluminum industry can and should take a global leadership position by actively developing internationally accepted and approved carbon footprint credit protocols.

Aluminum anode for aluminum-air battery - Part I: Influence of aluminum purity

Science.gov (United States)

Cho, Young-Joo; Park, In-Jun; Lee, Hyeok-Jae; Kim, Jung-Gu

2015-03-01

2N5 commercial grade aluminum (99.5% purity) leads to the lower aluminum-air battery performances than 4N high pure grade aluminum (99.99% purity) due to impurities itself and formed impurity complex layer which contained Fe, Si, Cu and others. The impurity complex layer of 2N5 grade Al declines the battery voltage on standby status. It also depletes discharge current and battery efficiency at 1.0 V which is general operating voltage of aluminum-air battery. However, the impurity complex layer of 2N5 grade Al is dissolved with decreasing discharge voltage to 0.8 V. This phenomenon leads to improvement of discharge current density and battery efficiency by reducing self-corrosion reaction. This study demonstrates the possibility of use of 2N5 grade Al which is cheaper than 4N grade Al as the anode for aluminum-air battery.

Effect of Punica granatum fruit peel on glucose-6-phosphate dehydrogenase and malate dehydrogenase in amphistome Gastrothylax indicus.

Science.gov (United States)

Aggarwal, Rama; Bagai, Upma

2017-03-01

Increasing anthelmintic resistance and the impact of conventional anthelmintics on the environment, it is important to look for alternative strategies against helminth parasite in sheep. Important lipogenic enzymes like glucose-6-phosphate dehydrogenase (G-6-PDH) and malate dehydrogenase (MDH) show subcellular distribution pattern. Activity of G-6-PDH was largely restricted to cytosolic fraction while MDH was found in both cytosolic and mitochondrial fraction in Gastrothylax indicus. Following in vitro treatment with ethanolic and aqueous extracts of Punica granatum fruit peel and commercial anthelmintic, albendazole G-6-PDH activity was decreased by 19-32 %, whereas MDH was suppressed by 24-41 %, compared to the respective control. Albendazole was quite effective when compared with negative control and both the extracts. The results indicate that phytochemicals of plant may act as potential vermifuge or vermicide.

MANAGEMENT OF RESEARCH AND TEST REACTOR ALUMINUM SPENT NUCLEAR FUEL - A TECHNOLOGY ASSESSMENT

Energy Technology Data Exchange (ETDEWEB)

Vinson, D.

2010-07-11

The Department of Energy's Environmental Management (DOE-EM) Program is responsible for the receipt and storage of aluminum research reactor spent nuclear fuel or used fuel until ultimate disposition. Aluminum research reactor used fuel is currently being stored or is anticipated to be returned to the U.S. and stored at DOE-EM storage facilities at the Savannah River Site and the Idaho Nuclear Technology and Engineering Center. This paper assesses the technologies and the options for safe transportation/receipt and interim storage of aluminum research reactor spent fuel and reviews the comprehensive strategy for its management. The U.S. Department of Energy uses the Appendix A, Spent Nuclear Fuel Acceptance Criteria, to identify the physical, chemical, and isotopic characteristics of spent nuclear fuel to be returned to the United States under the Foreign Research Reactor Spent Nuclear Fuel Acceptance Program. The fuel is further evaluated for acceptance through assessments of the fuel at the foreign sites that include corrosion damage and handleability. Transport involves use of commercial shipping casks with defined leakage rates that can provide containment of the fuel, some of which are breached. Options for safe storage include wet storage and dry storage. Both options must fully address potential degradation of the aluminum during the storage period. This paper focuses on the various options for safe transport and storage with respect to technology maturity and application.

NON-LINEAR TRANSIENT HEAT CONDUCTION ANALYSIS OF INSULATION WALL OF TANK FOR TRANSPORTATION OF LIQUID ALUMINUM

Directory of Open Access Journals (Sweden)

Miroslav M Živković

2010-01-01

Full Text Available This paper deals with transient nonlinear heat conduction through the insulation wall of the tank for transportation of liquid aluminum. Tanks designed for this purpose must satisfy certain requirements regarding temperature of loading and unloading, during transport. Basic theoretical equations are presented, which describe the problem of heat conduction finite element (FE analysis, starting from the differential equation of energy balance, taking into account the initial and boundary conditions of the problem. General 3D problem for heat conduction is considered, from which solutions for two- and one-dimensional heat conduction can be obtained, as special cases. Forming of the finite element matrices using Galerkin method is briefly described. The procedure for solving equations of energy balance is discussed, by methods of resolving iterative processes of nonlinear transient heat conduction. Solution of this problem illustrates possibilities of PAK-T software package, such as materials properties, given as tabular data, or analytical functions. Software also offers the possibility to solve nonlinear and transient problems with incremental methods. Obtained results for different thicknesses of the tank wall insulation materials enable its comparison in regards to given conditions

Glutamine and ornithine alpha-ketoglutarate supplementation on malate dehydrogenases expression in hepatectomized rats

OpenAIRE

Guimarães Filho, Artur; Cunha, Rodrigo Maranguape Silva da; Vasconcelos, Paulo Roberto Leitão de; Guimarães, Sergio Botelho

2014-01-01

PURPOSE: To evaluate the relative gene expression (RGE) of cytosolic (MDH1) and mitochondrial (MDH2) malate dehydrogenases enzymes in partially hepatectomized rats after glutamine (GLN) or ornithine alpha-ketoglutarate (OKG) suplementation. METHODS: One-hundred and eight male Wistar rats were randomly distributed into six groups (n=18): CCaL, GLNL and OKGL and fed calcium caseinate (CCa), GLN and OKG, 0.5g/Kg by gavage, 30 minutes before laparotomy. CCaH, GLNH and OKGH groups were likewise fe...

Validity of the Aluminum Equivalent Approximation in Space Radiation Shielding

Science.gov (United States)

Badavi, Francis F.; Adams, Daniel O.; Wilson, John W.

2009-01-01

The origin of the aluminum equivalent shield approximation in space radiation analysis can be traced back to its roots in the early years of the NASA space programs (Mercury, Gemini and Apollo) wherein the primary radiobiological concern was the intense sources of ionizing radiation causing short term effects which was thought to jeopardize the safety of the crew and hence the mission. Herein, it is shown that the aluminum equivalent shield approximation, although reasonably well suited for that time period and to the application for which it was developed, is of questionable usefulness to the radiobiological concerns of routine space operations of the 21 st century which will include long stays onboard the International Space Station (ISS) and perhaps the moon. This is especially true for a risk based protection system, as appears imminent for deep space exploration where the long-term effects of Galactic Cosmic Ray (GCR) exposure is of primary concern. The present analysis demonstrates that sufficiently large errors in the interior particle environment of a spacecraft result from the use of the aluminum equivalent approximation, and such approximations should be avoided in future astronaut risk estimates. In this study, the aluminum equivalent approximation is evaluated as a means for estimating the particle environment within a spacecraft structure induced by the GCR radiation field. For comparison, the two extremes of the GCR environment, the 1977 solar minimum and the 2001 solar maximum, are considered. These environments are coupled to the Langley Research Center (LaRC) deterministic ionized particle transport code High charge (Z) and Energy TRaNsport (HZETRN), which propagates the GCR spectra for elements with charges (Z) in the range I aluminum equivalent approximation for a good polymeric shield material such as genetic polyethylene (PE). The shield thickness is represented by a 25 g/cm spherical shell. Although one could imagine the progression to greater

Molecular regulation of aluminum resistance and sulfur nutrition during root growth.

Science.gov (United States)

Alarcón-Poblete, Edith; Inostroza-Blancheteau, Claudio; Alberdi, Miren; Rengel, Zed; Reyes-Díaz, Marjorie

2018-01-01

Aluminum toxicity and sulfate deprivation both regulate microRNA395 expression, repressing its low-affinity sulfate transporter ( SULTR2;1 ) target. Sulfate deprivation also induces the high-affinity sulfate transporter gene ( SULTR12 ), allowing enhanced sulfate uptake. Few studies about the relationships between sulfate, a plant nutrient, and aluminum, a toxic ion, are available; hence, the molecular and physiological processes underpinning this interaction are poorly understood. The Al-sulfate interaction occurs in acidic soils, whereby relatively high concentrations of trivalent toxic aluminum (Al 3+ ) may hamper root growth, limiting uptake of nutrients, including sulfur (S). On the other side, Al 3+ may be detoxified by complexation with sulfate in the acid soil solution as well as in the root-cell vacuoles. In this review, we focus on recent insights into the mechanisms governing plant responses to Al toxicity and its relationship with sulfur nutrition, emphasizing the role of phytohormones, microRNAs, and ion transporters in higher plants. It is known that Al 3+ disturbs gene expression and enzymes involved in biosynthesis of S-containing cysteine in root cells. On the other hand, Al 3+ may induce ethylene biosynthesis, enhance reactive oxygen species production, alter phytohormone transport, trigger root growth inhibition and promote sulfate uptake under S deficiency. MicroRNA395, regulated by both Al toxicity and sulfate deprivation, represses its low-affinity Sulfate Transporter 2;1 (SULTR2;1) target. In addition, sulfate deprivation induces High Affinity Sulfate Transporters (HAST; SULTR1;2), improving sulfate uptake from low-sulfate soil solutions. Identification of new microRNAs and cloning of their target genes are necessary for a better understanding of the role of molecular regulation of plant resistance to Al stress and sulfate deprivation.

Transport on prescription: How can GPs contribute to the promotion of active transport?

Science.gov (United States)

Pistoll, Chance; Furler, John

2017-10-01

Active transport (ie walking, cycling, using public transport) can play a part in reducing non-communicable diseases (NCDs). Very little is known about how general practitioners (GPs) can contribute to promoting active transport. We explored GPs' ideas around active transport, and potential barriers and facilitators to its promotion in the clinical setting. Using a maximal variation sample, we conducted 10 semi-structured interviews with GPs in Victoria, Australia. The socioecological model informed data collection and analysis. The idea of active transport resonated with GPs. Limited awareness around active transport and safety concerns regarding commuter cycling were barriers to clinical promotion. GPs believed patients' health, cultural norms, socioeconomic position and access to supportive environments could facilitate participation. Future efforts should prioritise awareness of active transport among GPs. The perspectives of GPs would be valuable to policymakers, particularly in designing programs to mitigate inequalities around active transport access and use.

Magnesium-Based Sacrificial Anode Cathodic Protection Coatings (Mg-Rich Primers for Aluminum Alloys

Directory of Open Access Journals (Sweden)

Michael D. Blanton

2012-09-01

Full Text Available Magnesium is electrochemically the most active metal employed in common structural alloys of iron and aluminum. Mg is widely used as a sacrificial anode to provide cathodic protection of underground and undersea metallic structures, ships, submarines, bridges, decks, aircraft and ground transportation systems. Following the same principle of utilizing Mg characteristics in engineering advantages in a decade-long successful R&D effort, Mg powder is now employed in organic coatings (termed as Mg-rich primers as a sacrificial anode pigment to protect aerospace grade aluminum alloys against corrosion. Mg-rich primers have performed very well on aluminum alloys when compared against the current chromate standard, but the carcinogenic chromate-based coatings/pretreatments are being widely used by the Department of Defense (DoD to protect its infrastructure and fleets against corrosion damage. Factors such as reactivity of Mg particles in the coating matrix during exposure to aggressive corrosion environments, interaction of atmospheric gases with Mg particles and the impact of Mg dissolution, increases in pH and hydrogen gas liberation at coating-metal interface, and primer adhesion need to be considered for further development of Mg-rich primer technology.

Antioxidant activity and protective effect of bee bread (honey and pollen) in aluminum-induced anemia, elevation of inflammatory makers and hepato-renal toxicity.

Science.gov (United States)

Bakour, Meryem; Al-Waili, Noori S; El Menyiy, Nawal; Imtara, Hamada; Figuira, Anna Cristina; Al-Waili, Thia; Lyoussi, Badiaa

2017-12-01

Aluminum toxicity might be related to oxidative stress, and the antioxidant activity and protective effect of bee bread, which contains pollen, honey and bees' enzymes, on aluminum induced blood and hepato-renal toxicity was investigated in rats. Chemical analysis and antioxidant capacity of bee bread were conducted. The animal experiment in rats included; group 1: received distilled water (10 ml/kg b.wt), group 2: received aluminum chloride (662.2 mg/kg b.wt), group 3: received aluminum chloride (662.2 mg/kg b.wt) and ethanolic extract of the bee bread (500 mg/kg b.wt), and group 4: received aluminum chloride (662.2 mg/kg b.wt) and ethanolic extract of the bee bread (750 mg/kg b.wt). Doses were given once daily via a gavage. C-reactive protein, transaminases, urea, creatinine, creatinine clearance, sodium and potassium and urine sodium and potassium were determined on day 28 of the experiment. Bee bread contained protein, fat, fiber, ash, carbohydrate, phenol and flavonoids and it exhibited antioxidant activity. Aluminum caused a significant elevation of blood urea, transaminase, C-reactive protein and monocyte count and significantly decreased hemoglobin. These changes were significantly ameliorated by the use of bee bread. Bee bread has an antioxidant property, and exhibited a protective effect on aluminum induced blood and hepato-renal toxicity and elevation of inflammatory markers C-reactive protein, leukocyte and monocyte counts.

5-lipoxygenase activation is involved in the mechanisms of chronic hepatic injury in a rat model of chronic aluminum overload exposure

Energy Technology Data Exchange (ETDEWEB)

Mai, Shaoshan [Department of Pharmacology, Chongqing Medical University, Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing 400016 (China); He, Qin [Department of Heptobiliary Surgery, 1st Affiliated Hospital, Chongqing Medical University, Chongqing 400016 (China); Wang, Hong; Hu, Xinyue; Luo, Ying; Yang, Yang; Kuang, Shengnan; Tian, Xiaoyan; Ma, Jie [Department of Pharmacology, Chongqing Medical University, Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing 400016 (China); Yang, Junqing, E-mail: 1139627371@qq.com [Department of Pharmacology, Chongqing Medical University, Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing 400016 (China)

2016-08-15

We previously confirmed that rats overloaded with aluminum exhibited hepatic function damage and increased susceptibility to hepatic inflammation. However, the mechanism of liver toxicity by chronic aluminum overload is poorly understood. In this study, we investigated changes in the 5-lipoxygenase (5-LO) signaling pathway and its effect on liver injury in aluminum-overloaded rats. A rat hepatic injury model of chronic aluminum injury was established via the intragastric administration of aluminum gluconate (Al{sup 3+} 200 mg/kg per day, 5 days a week for 20 weeks). The 5-LO inhibitor, caffeic acid (10 and 30 mg/kg), was intragastrically administered 1 h after aluminum administration. Hematoxylin and eosin staining was used to visualize pathological changes in rat liver tissue. A series of biochemical indicators were measured with biochemistry assay or ELISAs. Immunochemistry and RT-PCR methods were used to detect 5-LO protein and mRNA expression in the liver, respectively. Caffeic acid administration protected livers against histopathological injury, decreased plasma ALT, AST, and ALP levels, decreased TNF-α, IL-6, IL-1β and LTs levels, increased the reactive oxygen species content, and down-regulated the mRNA and protein expressions of 5-LO in aluminum overloaded rats. Our results indicate that 5-lipoxygenase activation is mechanistically involved in chronic hepatic injury in a rat model of chronic aluminum overload exposure and that the 5-LO signaling pathway, which associated with inflammation and oxidative stress, is a potential therapeutic target for chronic non-infection liver diseases. - Highlights: • 5-LO signaling contributes to mechanisms of hepatotoxicity of aluminum overload. • Oxidative and inflammatory reaction involve in chonic aluminum hepatotoxicity. • 5-LO inhibitor has a protective effect on aluminum-overload liver injury. • 5-LO signaling is a potential therapeutic target for non-infection liver diseases.

Packaging material and aluminum. Hoso zairyo to aluminum

Energy Technology Data Exchange (ETDEWEB)

Itaya, T [Mitsubishi Aluminum Co. Ltd., Tokyo (Japan)

1992-02-01

The present paper introduces aluminum foil packaging materials among the relation between packing materials and aluminum. The characteristics of aluminum foil in the packaging area are in its barrier performance, non-toxicity, tastelessness and odorlessness. Its excellent functions and processibility suit best as functional materials for food, medicine and industrial material packaging. While an aluminum foil may be used as a single packing material as in foils used in homes, many of it as a packaging material are used in combination with adhesives, papers or plastic films, or coated or printed. It is used as composite materials laminated or coated with other materials according to their use for the purpose of complementing the aluminum foil as the base material. Representative method to laminate aluminum foils include the wet lamination, dry lamination, thermally dissolved lamination and extruded lamination. The most important quality requirement in lamination is the adhesion strength, which requires a close attention in selecting the kinds of adhesive, laminating conditions, and aging conditions. 8 figs., 6 tabs.

Method of melting and decontaminating radioactive contaminated aluminum material

International Nuclear Information System (INIS)

Uda, Tatsuhiko; Miura, Noboru; Kawasaki, Katsuo; Iba, Hajime.

1986-01-01

Purpose: To improve the decontaminating efficiency upon melting decontamination of radioactive-contaminated aluminum materials. Method: This invention concerns an improvement for the method of melting decontamination by adding slug agent composed of organic compound to contaminated aluminum material and extracting the radioactive materials into the slug thereby decontaminating the aluminum material. Specifically metals effective for reducing the active amount of aluminum are added such that the content is greater than a predetermined value in the heat melting process. The metal comprises Mg, Cu or a mixture thereof and the content is more than 4 % including those previously contained in the aluminum material. (Ikeda, J.)

Active transport among Czech school-aged children

Directory of Open Access Journals (Sweden)

Jan Pavelka

2012-09-01

Full Text Available BACKGROUND: Active transport is a very important factor for increasing the level of physical activity in children, which is significant for both their health and positive physical behaviour in adult age. OBJECTIVE: The aim of the study was to establish the proportion of Czech children aged 11 to 15 who select active transport to and from school and, at the same time, describe socio-economic and socio-demographic factors influencing active transport to and from school among children. METHODS: To establish the socio-demographic factors affecting active transport, data of a national representative sample of 11 to 15 year-old elementary school children in the Czech Republic (n = 4,425. Research data collection was performed within an international research study called Health Behaviour in School Aged Children in June 2010. Statistical processing of the results was made using a logistic regression analysis in the statistical programme IBM SPSS v 20. RESULTS: Active transport to and from school is opted for in the Czech Republic by approximately 2/3 of children aged 11 to 15. Differences between genders are not statistically significant; most children opting for active transport are aged 11 (69%. An important factor increasing the probability of active transport as much as 16 times is whether a child's place of residence is in the same municipality as the school. Other factors influencing this choice include BMI, time spent using a computer or a privateroom in a family. A significant factor determining active transport by children is safety; safe road crossing, opportunity to leave a bicycle safely at school, no fear of being assaulted on the way or provision of school lockers where children can leave their items. CONCLUSIONS: Active transport plays an important role in increasing the overall level of physical activity in children. Promotion of active transport should focus on children who spend more time using a computer; attention should also be

Helium trapping in aluminum and sintered aluminum powders

International Nuclear Information System (INIS)

Das, S.K.; Kaminsky, M.; Rossing, T.

1975-01-01

The surface erosion of annealed aluminum and of sintered aluminum powder (SAP) due to blistering from implantation of 100-keV 4 He + ions at room temperature has been investigated. A substantial reduction in the blistering erosion rate in SAP was observed from that in pure annealed aluminum. In order to determine whether the observed reduction in blistering is due to enhanced helium trapping or due to helium released, the implanted helium profiles in annealed aluminum and in SAP have been studied by Rutherford backscattering. The results show that more helium is trapped in SAP than in aluminum for identical irradiation conditions. The observed reduction in erosion from helium blistering in SAP is more likely due to the dispersion of trapped helium at the large Al-Al 2 O 3 interfaces and at the large grain boundaries in SAP than to helium release

Regulation by magnesium of potato tuber mitochondrial respiratory activities.

Science.gov (United States)

Vicente, Joaquim A F; Madeira, Vítor M C; Vercesi, Anibal E

2004-12-01

Dehydrogenase activities of potato tuber mitochondria and corresponding phosphorylation rates were measured for the dependence on external and mitochondrial matrix Mg2+. Magnesium stimulated state 3 and state 4 respiration, with significantly different concentrations of matrix Mg2+ required for optimal activities of the several substrates. Maximal stimulation of respiration with all substrates was obtained at 2-mM external Mg2+. However, respiration of malate, citrate, and alpha-ketoglutarate requires at least 4-mM Mg2+ inside mitochondria for maximization of dehydrogenase activities. The phosphorylation system, requires a low level of internal Mg2+ (0.25 mM) to reach high activity, as judged by succinate-dependent respiration. However, mitochondria respiring on citrate or alpha-ketoglutarate only sustain high levels of phosphorylation with at least 4-mM matrix Mg2+. Respiration of succinate is active without external and matrix Mg2+, although stimulated by the cation. Respiration of alpha-ketoglutarate was strictly dependent on external Mg2+ required for substrate transport into mitochondria, and internal Mg2+ is required for dehydrogenase activity. Respiration of citrate and malate also depend on internal Mg2+ but, unlike alpha-ketoglutarate, some activity still remains without external Mg2+. All the substrates revealed insensitive to external and internal mitochondrial Ca2+, except the exogenous NADH dehydrogenase, which requires either external Ca2+ or Mg2+ for detectable activity. Calcium is more efficient than Mg2+, both having cumulative stimulation. Unlike Ca2+, Mn2+ could substitute for Mg2+, before and after addition of A23, showing its ability to regulate phosphorylation and succinate dehydrogenase activities, with almost the same efficiency as Mg2+.

Graphene-aluminum nanocomposites

International Nuclear Information System (INIS)

Bartolucci, Stephen F.; Paras, Joseph; Rafiee, Mohammad A.; Rafiee, Javad; Lee, Sabrina; Kapoor, Deepak; Koratkar, Nikhil

2011-01-01

Highlights: → We investigated the mechanical properties of aluminum and aluminum nanocomposites. → Graphene composite had lower strength and hardness compared to nanotube reinforcement. → Processing causes aluminum carbide formation at graphene defects. → The carbides in between grains is a source of weakness and lowers tensile strength. - Abstract: Composites of graphene platelets and powdered aluminum were made using ball milling, hot isostatic pressing and extrusion. The mechanical properties and microstructure were studied using hardness and tensile tests, as well as electron microscopy, X-ray diffraction and differential scanning calorimetry. Compared to the pure aluminum and multi-walled carbon nanotube composites, the graphene-aluminum composite showed decreased strength and hardness. This is explained in the context of enhanced aluminum carbide formation with the graphene filler.

Health Impacts of Active Transportation in Europe

DEFF Research Database (Denmark)

Rojas-Rueda, David; de Nazelle, Audrey; Andersen, Zorana J

2016-01-01

Policies that stimulate active transportation (walking and bicycling) have been related to heath benefits. This study aims to assess the potential health risks and benefits of promoting active transportation for commuting populations (age groups 16-64) in six European cities. We conducted a health...... reduce carbon dioxide emissions in the six cities by 1,139 to 26,423 (metric tonnes per year). Policies to promote active transportation may produce health benefits, but these depend of the existing characteristics of the cities. Increased collaboration between health practitioners, transport specialists...... and urban planners will help to introduce the health perspective in transport policies and promote active transportation....

A melt refining method for uranium-contaminated aluminum

International Nuclear Information System (INIS)

Uda, T.; Iba, H.; Hanawa, K.

1986-01-01

Melt refining of uranium-contaminated aluminum which has been difficult to decontaminate because of the high reactivity of aluminum, was experimentally studied. Samples of contaminated aluminum and its alloys were melted after adding various halide fluxes at various melting temperatures and various melting times. Uranium concentration in the resulting ingots was determined. Effective flux compositions were mixtures of chlorides and fluorides, such as LiF, KCl, and BaCl 2 , at a fluoride/chloride mole ratio of 1 to 1.5. The removal of uranium from aluminum (the ''decontamination effect'') increased with decreasing melting temperature, but the time allowed for reaction had little influence. Pure aluminum was difficult to decontaminate from uranium; however, uranium could be removed from alloys containing magnesium. This was because the activity of the aluminum was decreased by formation of the intermetallic compound Al-Mg. With a flux of LiF-KCl-BaCl 2 and a temperature of 800 0 C, uranium added to give an initial concentration of 500 ppm was removed from a commercial alloy of aluminum, A5056, which contains 5% magnesium, to a final concentration of 0.6 ppm, which is near that in the initial aluminum alloy

Active transportation and public transportation use to achieve physical activity recommendations? A combined GPS, accelerometer, and mobility survey study.

Science.gov (United States)

Chaix, Basile; Kestens, Yan; Duncan, Scott; Merrien, Claire; Thierry, Benoît; Pannier, Bruno; Brondeel, Ruben; Lewin, Antoine; Karusisi, Noëlla; Perchoux, Camille; Thomas, Frédérique; Méline, Julie

2014-09-27

Accurate information is lacking on the extent of transportation as a source of physical activity, on the physical activity gains from public transportation use, and on the extent to which population shifts in the use of transportation modes could increase the percentage of people reaching official physical activity recommendations. In 2012-2013, 234 participants of the RECORD GPS Study (French Paris region, median age = 58) wore a portable GPS receiver and an accelerometer for 7 consecutive days and completed a 7-day GPS-based mobility survey (participation rate = 57.1%). Information on transportation modes and accelerometry data aggregated at the trip level [number of steps taken, energy expended, moderate to vigorous physical activity (MVPA), and sedentary time] were available for 7,644 trips. Associations between transportation modes and accelerometer-derived physical activity were estimated at the trip level with multilevel linear models. Participants spent a median of 1 h 58 min per day in transportation (8.2% of total time). Thirty-eight per-cent of steps taken, 31% of energy expended, and 33% of MVPA over 7 days were attributable to transportation. Walking and biking trips but also public transportation trips with all four transit modes examined were associated with greater steps, MVPA, and energy expenditure when compared to trips by personal motorized vehicle. Two simulated scenarios, implying a shift of approximately 14% and 33% of all motorized trips to public transportation or walking, were associated with a predicted 6 point and 13 point increase in the percentage of participants achieving the current physical activity recommendation. Collecting data with GPS receivers, accelerometers, and a GPS-based electronic mobility survey of activities and transportation modes allowed us to investigate relationships between transportation modes and physical activity at the trip level. Our findings suggest that an increase in active transportation

Calcium signaling in brain mitochondria: interplay of malate aspartate NADH shuttle and calcium uniporter/mitochondrial dehydrogenase pathways.

Science.gov (United States)

Contreras, Laura; Satrústegui, Jorgina

2009-03-13

Ca2+ signaling in mitochondria has been mainly attributed to Ca2+ entry to the matrix through the Ca2+ uniporter and activation of mitochondrial matrix dehydrogenases. However, mitochondria can also sense increases in cytosolic Ca2+ through a mechanism that involves the aspartate-glutamate carriers, extramitochondrial Ca2+ activation of the NADH malate-aspartate shuttle (MAS). Both pathways are linked through the shared substrate alpha-ketoglutarate (alphaKG). Here we have studied the interplay between the two pathways under conditions of Ca2+ activation. We show that alphaKG becomes limiting when Ca2+ enters in brain or heart mitochondria, but not liver mitochondria, resulting in a drop in alphaKG efflux through the oxoglutarate carrier and in a drop in MAS activity. Inhibition of alphaKG efflux and MAS activity by matrix Ca2+ in brain mitochondria was fully reversible upon Ca2+ efflux. Because of their differences in cytosolic calcium concentration requirements, the MAS and Ca2+ uniporter-mitochondrial dehydrogenase pathways are probably sequentially activated during a Ca2+ transient, and the inhibition of MAS at the center of the transient may provide an explanation for part of the increase in lactate observed in the stimulated brain in vivo.

Use of low-cost aluminum in electric energy production

Science.gov (United States)

Zhuk, Andrey Z.; Sheindlin, Alexander E.; Kleymenov, Boris V.; Shkolnikov, Eugene I.; Lopatin, Marat Yu.

Suppression of the parasitic corrosion while maintaining the electrochemical activity of the anode metal is one of the serious problems that affects the energy efficiency of aluminum-air batteries. The need to use high-purity aluminum or special aluminum-based alloys results in a significant increase in the cost of the anode, and thus an increase in the total cost of energy generated by the aluminum-air battery, which narrows the range of possible applications for this type of power source. This study considers the process of parasitic corrosion as a method for hydrogen production. Hydrogen produced in an aluminum-air battery by this way may be further employed in a hydrogen-air fuel cell (Hy-air FC) or in a heat engine, or it may be burnt to generate heat. Therefore, anode materials may be provided by commercially pure aluminum, commercially produced aluminum alloys, and secondary aluminum. These materials are much cheaper and more readily available than special anode alloys of aluminum and high-purity aluminum. The aim of present study is to obtain experimental data for comparison of energy and cost parameters of some commercially produced aluminum alloys, of high-purity aluminum, and of a special Al-ln anode alloy in the context of using these materials as anodes for an Al-air battery and for combined production of electrical power and hydrogen.

Active transport and heat.

Science.gov (United States)

Tait, Peter W

2011-07-01

Increasing heat may impede peoples' ability to be active outdoors thus limiting active transport options. Co-benefits from mitigation of and adaptation to global warming should not be assumed but need to be actively designed into strategies.

Selective Adsorption of Sodium Aluminum Fluoride Salts from Molten Aluminum

Energy Technology Data Exchange (ETDEWEB)

Leonard S. Aubrey; Christine A. Boyle; Eddie M. Williams; David H. DeYoung; Dawid D. Smith; Feng Chi

2007-08-16

Aluminum is produced in electrolytic reduction cells where alumina feedstock is dissolved in molten cryolite (sodium aluminum fluoride) along with aluminum and calcium fluorides. The dissolved alumina is then reduced by electrolysis and the molten aluminum separates to the bottom of the cell. The reduction cell is periodically tapped to remove the molten aluminum. During the tapping process, some of the molten electrolyte (commonly referred as “bath” in the aluminum industry) is carried over with the molten aluminum and into the transfer crucible. The carryover of molten bath into the holding furnace can create significant operational problems in aluminum cast houses. Bath carryover can result in several problems. The most troublesome problem is sodium and calcium pickup in magnesium-bearing alloys. Magnesium alloying additions can result in Mg-Na and Mg-Ca exchange reactions with the molten bath, which results in the undesirable pickup of elemental sodium and calcium. This final report presents the findings of a project to evaluate removal of molten bath using a new and novel micro-porous filter media. The theory of selective adsorption or removal is based on interfacial surface energy differences of molten aluminum and bath on the micro-porous filter structure. This report describes the theory of the selective adsorption-filtration process, the development of suitable micro-porous filter media, and the operational results obtained with a micro-porous bed filtration system. The micro-porous filter media was found to very effectively remove molten sodium aluminum fluoride bath by the selective adsorption-filtration mechanism.

Action of the antitumor and antispermatogenic agent lonidamine on electron transport in Ehrlich ascites tumor mitochondria.

Science.gov (United States)

Floridi, A; Lehninger, A L

1983-10-01

The effect of lonidamine, an antispermatogenic and antitumor drug, on the oxygen consumption, ATPase activity, and redox state of the electron carriers of Ehrlich ascites tumor mitochondria has been studied. Lonidamine inhibits ADP- and uncoupler-stimulated respiration on various NAD- and FAD-linked substrates, but does not affect state 4 respiration. Experiments to determine its site of action showed that lonidamine does not significantly inhibit electron flow through cytochrome oxidase. Electron flow through site 2, the ubiquinone-cytochrome b-cytochrome c1 complex, also was unaffected by lonidamine, which failed to inhibit the oxidation of duroquinol. Moreover, inhibition of electron flow through site 2 was also excluded because of the inability of the N,N,N',N'-tetramethyl-p-phenylenediamine bypass to relieve the lonidamine inhibition of the oxidation of pyruvate + malate. The F0F1ATPase activity and vectorial H+ ejection are also unaffected by lonidamine. The inhibition of succinate oxidation by lonidamine was found to take place at a point between succinate and iron-sulfur center S3. Spectroscopic experiments demonstrated that lonidamine inhibits the reduction of mitochondrial NAD+ by pyruvate + malate and other NAD-linked substrates in the transition from state 1 to state 4. However, lonidamine does not inhibit reduction of added NAD+ by submitochondrial vesicles or by soluble purified NAD-linked dehydrogenases. These observations, together with other evidence, suggest that electron transport in tumor mitochondria is inhibited by lonidamine at the dehydrogenase-coenzyme level, particularly when the electron carriers are in a relatively oxidized state and/or when the inner membrane-matrix compartment is in the condensed state. The action of lonidamine in several respects resembles the selective inhibition of electron transport in tumor cells produced by cytotoxic macrophages (D. L. Granger and A. L. Lehninger (1982) J. Cell Biol. 95, 527).

Effect of temperature oscillation on thermal characteristics of an aluminum thin film

Science.gov (United States)

Ali, H.; Yilbas, B. S.

2014-12-01

Energy transport in aluminum thin film is examined due to temperature disturbance at the film edge. Thermal separation of electron and lattice systems is considered in the analysis, and temperature variation in each sub-system is formulated. The transient analysis of frequency-dependent and frequency-independent phonon radiative transport incorporating electron-phonon coupling is carried out in the thin film. The dispersion relations of aluminum are used in the frequency-dependent analysis. Temperature at one edge of the film is oscillated at various frequencies, and temporal response of phonon intensity distribution in the film is predicted numerically using the discrete ordinate method. To assess the phonon transport characteristics, equivalent equilibrium temperature is introduced. It is found that equivalent equilibrium temperature in the electron and lattice sub-systems oscillates due to temperature oscillation at the film edge. The amplitude of temperature oscillation reduces as the distance along the film thickness increases toward the low-temperature edge of the film. Equivalent equilibrium temperature attains lower values for the frequency-dependent solution of the phonon transport equation than that corresponding to frequency-independent solution.

Angular neutron transport investigation in the HZETRN free-space ion and nucleon transport and shielding computer program

International Nuclear Information System (INIS)

Singleterry, R.C. Jr.; Wilson, J.W.

1997-01-01

Extension of the high charge and energy (HZE) transport computer program HZETRN for angular transport of neutrons is considered. For this paper, only light ion transport, He 4 and lighter, will be analyzed using a pure solar proton source. The angular transport calculator is the ANISN/PC program which is being controlled by the HZETRN program. The neutron flux values are compared for straight-ahead transport and angular transport in one dimension. The shield material is aluminum and the target material is water. The thickness of these materials is varied; however, only the largest model calculated is reported which is 50 gm/cm 2 of aluminum and 100 gm/cm 2 of water. The flux from the ANISN/PC calculation is about two orders of magnitude lower than the flux from HZETRN for very low energy neutrons. It is only a magnitude lower for the neutrons in the 10 to 20 MeV range in the aluminum and two orders lower in the water. The major reason for this difference is in the transport modes: straight-ahead versus angular. The angular treatment allows a longer path length than the straight-ahead approximation. Another reason is the different cross section sets used by the ANISN/PC-BUGLE-80 mode and the HZETRN mode. The next step is to investigate further the differences between the two codes and isolate the differences to just the angular versus straight-ahead transport mode. Then, create a better coupling between the angular neutron transport and the charged particle transport

Bone aluminum measurements in patients with end-stage renal disease

International Nuclear Information System (INIS)

Ellis, K.J.; Kelleher, S.P.

1986-01-01

Long-term use of aluminum-based phosphate binders and trace aluminum contamination of dialysate solution have led to increased body burden of this metal in patients with end-stage renal disease. Aluminum accumulates in bone and has been associated with the development of a renal osteodystrophy, called aluminum-induced osteomalacia. At present, bone biopsy is the method of diagnosis of this condition. When examined by quantitative histomorphometry, the aluminum accumulation was reported to correlate with the severity of the osteomalacia. This project was therefore undertaken to investigate the possibility of developing a non-invasive technique using neutron activation analysis for the direct in vivo assessment of bone aluminum levels. A bilateral exposure of the patient's hand is performed at the patient port of the Brookhaven Medical Research Reactor. The induced activity is then counted for 5 min using four 4'' x 4'' x 16'' NaI(T1) detectors arranged in a quasi-4! geometry. In addition to Al, Ca is also detected and serves as each individual's internal standard for the volume of bone mass irradiated. The Al/Ca ratio provides an index of the amount of elevated aluminum per unit bone mass. When this ratio is multiplied by the total body calcium value, an estimate of total skeletal aluminum is obtained. These measurements will be presented for a pilot study of ten asymptomatic renal patients

Geminal phosphorus/aluminum-based frustrated Lewis pairs: C-H versus C≡C activation and CO2 fixation

NARCIS (Netherlands)

Appelt, C.; Westenberg, H.; Bertini, F.; Ehlers, A.W.; Slootweg, J.C.; Lammertsma, K.; Uhl, W.

2011-01-01

Catch it! Geminal phosphorus/aluminum-based frustrated Lewis pairs (FLPs) are easily obtained by hydroalumination of alkynylphosphines. These FLPs can activate terminal acetylenes by two competitive pathways, which were analyzed by DFT calculations, and they can bind carbon dioxide reversibly.

Aluminum Solubility in Complex Electrolytes - 13011

Energy Technology Data Exchange (ETDEWEB)

Agnew, S.F. [Columbia Energy and Environmental Services, Inc., 1806 Terminal Dr., Richland, WA 99354 (United States); Johnston, C.T. [Dept. of Crop, Soil, and Environmental Sciences, Purdue University, West Lafayette, IN 47907 (United States)

2013-07-01

Predicting aluminum solubility for Hanford and Savannah River waste liquids is very important for their disposition. It is a key mission goal at each Site to leach as much aluminum as practical from sludges in order to minimize the amount of vitrified high level waste. And it is correspondingly important to assure that any soluble aluminum does not precipitate during subsequent decontamination of the liquid leachates with ion exchange. This report shows a very simple and yet thermodynamic model for aluminum solubility that is consistent with a wide range of Al liquors, from simple mixtures of hydroxide and aluminate to over 300 Hanford concentrates and to a set of 19 Bayer liquors for temperatures from 20-100 deg. C. This dimer-dS{sub mix} (DDS) model incorporates an ideal entropy of mixing along with previous reports for the Al dimer, water activities, gibbsite, and bayerite thermodynamics. We expect this model will have broad application for nuclear wastes as well as the Bayer gibbsite process industry. (authors)

Painting rusted steel: The role of aluminum phosphosilicate

International Nuclear Information System (INIS)

Roselli, S.N.; Amo, B. del; Carbonari, R.O.; Di Sarli, A.R.; Romagnoli, R.

2013-01-01

Highlights: •Aluminum phosphosilicate is an acid pigment which could act as mild phosphating agent. •Aluminum phosphosilicate can phosphatize iron oxides on rusted surfaces. •Aluminum phosphosilicate is compatible with acid binders. •Aluminum phosphosilicate could replace chromate in complete painting schemes. •Aluminum phosphosilicate primers improve paints adhesion on rusted surfaces. -- Abstract: Surface preparation is a key factor for the adequate performance of a paint system. The aim of this investigation is to employ a wash-primer to accomplish the chemical conversion of rusted surface when current cleaning operations are difficult to carry out. The active component of the wash-primer was aluminum phosphosilicate whose electrochemical behavior and the composition of the generated protective layer, both, were studied by electrochemical techniques and scanning electron microscopy (SEM), respectively. Primed rusted steel panels were coated with an alkyd system to perform accelerated tests in the salt spray chamber and electrochemical impedance measurements (EIS). These tests were conducted in parallel with a chromate wash primer and the same alkyd system. Results showed that the wash-primer containing aluminum phosphosilicate could be used satisfactorily to paint rusted steel exhibiting a similar performance to the chromate primer

A study on aluminum determination in environmental samples by Neutron Activation Analysis

International Nuclear Information System (INIS)

Noyori, Amanda

2017-01-01

Aluminum determinations are of great interest since this element is toxic to humans and it is widely distributed in the environment. Besides, the determinations of this element by conventional analytical methods present difficulties due to sample contamination during the analyses. Neutron activation analysis (NAA) for Al determination presents advantages of fast analyses and of high sensitivity. However, NAA of Al does present problems of P and Si nuclear reaction interferences. Aluminum is determined by measuring 28 Al, formed in the reaction 27 Al (n, γ) 28 Al, the same radioisotope formed in reactions 31 P (n, α) 28 Al and 28 Si (n, p) 28 Al. The purpose of this study was to determine Al in environmental samples by NAA correcting these interferences using correction factors, and determining P and Si concentrations in the samples. In this study, certified reference materials and biomonitor samples (tree barks and lichen) were analyzed. Experimental procedure consisted of irradiating an aliquot of the sample at the IEA-R1 nuclear research reactor together with Al standard, followed by gamma ray spectrometry. Phosphorus was determined by measuring beta radiation of 32 P using a Geiger-Müller counter. Silicon was determined by epithermal neutron activation analysis and measuring 29 Al formed in the reaction 29 Si (n, p) 29 Al. Results obtained in the determination of Al, P and Si in the certified reference materials showed good precision and accuracy with |Z-score| ≤ 2. Aluminum results in the biomonitor samples varied from to 253 to 15783 μg g -1 . In the case of P its concentrations varied from 283 to 1946 μg g -1 . Silicon determinations in biomonitors varied from 0.11 to 7.8 %. The interference contribution rates in the analyses of the biomonitor samples were of the order of 2.0 % and this contribution depends on the relation between concentrations of interfering elements and of Al in the sample. Detection limit values of Al in the biomonitor analyses

Low-temperature, solution-processed aluminum-doped zinc oxide as electron transport layer for stable efficient polymer solar cells

Energy Technology Data Exchange (ETDEWEB)

Zhu, Qianqian [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Bao, Xichang, E-mail: baoxc@qibebt.ac.cn [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Yu, Jianhua [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zhu, Dangqiang [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Zhang, Qian [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Gu, Chuantao [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Dong, Hongzhou [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Yang, Renqiang [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Dong, Lifeng, E-mail: DongLifeng@qust.edu.cn [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Department of Physics, Hamline University, St. Paul, MN 55104 (United States)

2016-04-30

A simple low-temperature solution-processed zinc oxide (ZnO) and aluminum-doped ZnO (AZO) were synthesized and investigated as an electron transport layer (ETL) for inverted polymer solar cells. A solar cell with a blend of poly(4,8-bis-alkyloxy-benzo[1,2-b:4,5-b′] dithiophene-alt-alkylcarbonyl-thieno [3,4-b] thiophene) and (6,6)-phenyl-C71-butyric acid methyl ester as an active layer and AZO as ETL demonstrates a high power conversion efficiency (PCE) of 7.36% under the illumination of AM 1.5G, 100 mW/cm{sup 2}. Compared to the cells with ZnO ETL (PCE of 6.85%), the PCE is improved by 7.45% with the introduction of an AZO layer. The improved PCE is ascribed to the enhanced short circuit current density, which results from the electron transport property of the AZO layer. Moreover, AZO is a more stable interfacial layer than ZnO. The PCE of the solar cells with AZO as ETL retain 85% of their original value after storage for 120 days, superior to the 39% of cells with ZnO ETL. The results above indicate that a simple low-temperature solution-processed AZO film is an efficient and economical ETL for high-performance inverted polymer solar cells. Due to its environmental friendliness, good electrical properties, and simple preparation approach, AZO has the potential to be applied in high-performance, large-scale industrialization of solar cells and other electronic devices. - Highlights: • ZnO and AZO were synthesized by a simple low-temperature solution-processed method. • AZO films show high transmittance and conductivity. • The photovoltaic performance can be improved with AZO as ETL. • AZO-based devices demonstrate excellent stability, with 85% retained after 120 days.

Identification and Functional Characterization of a Tonoplast Dicarboxylate Transporter in Tomato (Solanum lycopersicum).

Science.gov (United States)

Liu, Ruiling; Li, Boqiang; Qin, Guozheng; Zhang, Zhanquan; Tian, Shiping

2017-01-01

Acidity plays an important role in flavor and overall organoleptic quality of fruit and is mainly due to the presence of organic acids. Understanding the molecular basis of organic acid metabolism is thus of primary importance for fruit quality improvement. Here, we cloned a putative tonoplast dicarboxylate transporter gene ( SlTDT ) from tomato, and submitted it to the NCBI database (GenBank accession number: KC733165). SlTDT protein contained 13 putative transmembrane domains in silico analysis. Confocal microscopic study using green fluorescent fusion proteins revealed that SlTDT was localized on tonoplast. The expression patterns of SlTDT in tomato were analyzed by RT-qPCR. The results indicated that SlTDT expressed in leaves, roots, flowers and fruits at different ripening stages, suggesting SlTDT may be associated with the development of different tissues. To further explore the function of SlTDT , we constructed both overexpression and RNAi vectors and obtained transgenic tomato plants by agrobacterium-mediated method. Gas chromatography-mass spectrometer (GC-MS) analysis showed that overexpression of SlTDT significantly increased malate content, and reduced citrate content in tomato fruit. By contrast, repression of SlTDT in tomato reduced malate content of and increased citrate content. These results indicated that SlTDT played an important role in remobilization of malate and citrate in fruit vacuoles.

Functional aluminum alloys for ultra high vacuum use

International Nuclear Information System (INIS)

Kato, Yutaka; Tsukamoto, Kenji; Isoyama, Eizo

1985-01-01

Ultra high vacuum systems made of aluminum alloys are actively developed. The reasons for using aluminum alloys are low residual radioactivity, light weight, good machinability, good thermal conductivity, non-magnetism. The important function required for ultra high vacuum materials is low outgassing rate, but surface gas on ordinary aluminum is much. Then the research on aluminum surface structure with low outgassing rate has been made and the special extrusion method, that is, extrusion method with the conditions of preventing air from entering inside of pipe and of taking in mixture gas of Ar + O 2 , was developed. 6063 alloy obtained by special extrusion method showed low outgassing rate (2 x 10 -13 Torr. 1/s. cm 2 ) by only 150 deg C, 24 h baking. For the future it will be important to develop aluminum alloys with low dynamic outgassing rate as well as low static outgassing rate. (author)

Aluminum recovery as a product with high added value using aluminum hazardous waste

International Nuclear Information System (INIS)

David, E.; Kopac, J.

2013-01-01

Highlights: • Granular and compact aluminum dross were physically and chemically characterized. • A relationship between density, porosity and metal content from dross was established. • Chemical reactions involving aluminum in landfill and negative consequences are shown. • A processing method for aluminum recovering from aluminum dross was developed. • Aluminum was recovered as an value product with high grade purity such as alumina. -- Abstract: The samples of hazardous aluminum solid waste such as dross were physically and chemically characterized. A relationship between density, porosity and metal content of dross was established. The paper also examines the chemical reactions involving aluminum dross in landfill and the negative consequences. To avoid environmental problems and to recovery the aluminum, a processing method was developed and aluminum was recovered as an added value product such as alumina. This method refers to a process at low temperature, in more stages: acid leaching, purification, precipitation and calcination. At the end of this process aluminum was extracted, first as Al 3+ soluble ions and final as alumina product. The composition of the aluminum dross and alumina powder obtained were measured by applying the leaching tests, using atomic absorption spectrometry (AAS) and chemical analysis. The mineralogical composition of aluminum dross samples and alumina product were determined by X-ray diffraction (XRD) and the morphological characterization was performed by scanning electron microscopy (SEM). The method presented in this work allows the use of hazardous aluminum solid waste as raw material to recover an important fraction from soluble aluminum content as an added value product, alumina, with high grade purity (99.28%)

The role of aluminum sensing and signaling in plant aluminum resistance.

Science.gov (United States)

Liu, Jiping; Piñeros, Miguel A; Kochian, Leon V

2014-03-01

As researchers have gained a better understanding in recent years into the physiological, molecular, and genetic basis of how plants deal with aluminum (Al) toxicity in acid soils prevalent in the tropics and sub-tropics, it has become clear that an important component of these responses is the triggering and regulation of cellular pathways and processes by Al. In this review of plant Al signaling, we begin by summarizing the understanding of physiological mechanisms of Al resistance, which first led researchers to realize that Al stress induces gene expression and modifies protein function during the activation of Al resistance responses. Subsequently, an overview of Al resistance genes and their function provides verification that Al induction of gene expression plays a major role in Al resistance in many plant species. More recent research into the mechanistic basis for Al-induced transcriptional activation of resistance genes has led to the identification of several transcription factors as well as cis-elements in the promoters of Al resistance genes that play a role in greater Al-induced gene expression as well as higher constitutive expression of resistance genes in some plant species. Finally, the post-transcriptional and translational regulation of Al resistance proteins is addressed, where recent research has shown that Al can both directly bind to and alter activity of certain organic acid transporters, and also influence Al resistance proteins indirectly, via protein phosphorylation. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Effects of exogenous salicylic acid on cell wall polysaccharides and aluminum tolerance of trichosanthes kirilowii

International Nuclear Information System (INIS)

Xu, G.; Liu, D.; Xio, Y.; Liu, P.; Gao, P. P.; Cao, L.; Wu, Y.

2015-01-01

A hydroponic experiment was conducted to study the effects of exogenous salicylic acid (SA) on root length, relative aluminum content in the apical cell wall, acid phosphatase (APA) and pectin methyl esterase (PME) activity, root pectin, hemicellulose 1(HC1), and hemicellulose 2 (HC2) contents of Anguo Trichosanthes kirilowii (Al-tolerant genotype) and Pujiang T. kirilowii (Al-sensitive genotype) under 800 micro mol/L of aluminum stress. The results showed that the growth of Al-tolerant Anguo T. kirilowii and Al-sensitive Pujiang T. kirilowii was inhibited when exposed to 800 micro mol/L of aluminum solution. APA and PME activities were also enhanced for both genotypes. The contents of relative aluminum, pectin, HC1, and HC2, as well as Al accumulation in the root tips were increased under aluminum toxicity. Pujiang T. kirilowii showed higher enzyme activity and cell wall polysaccharide contents than Anguo T. kirilowii. In addition, the root cell wall pectin, HC1, and HC2 contents of Pujiang T. kirilowii were increased by a large margin, showing its greater sensitivity to aluminum toxicity. Root length is an important indicator of aluminum toxicity, and has an important relationship with cell wall polysaccharide content. Aluminum toxicity led to the accumulation of pectin and high PME activity, and also increased the number of free carboxyl groups, which have more aluminum binding sites. Membrane skim increased extensively with the increase in APA activity, damaging membrane structure and function. Different SA concentrations can decrease enzyme activity and cell wall polysaccharide content to some extent. With the addition of different SA concentrations, the root relative aluminum content, cell wall polysaccharide content, APA and PME activities decreased. Aluminum toxicity to both genotypes of T. kirilowii was relieved in different degrees as exogenous SA concentration increased. Inter-simple sequence repeat (ISSR) marker was used to examine the genetic distance

In-situ Electrodeposition of Highly Active Silver Catalyst on Carbon Fiber Papers as Binder Free Cathodes for Aluminum-air Battery.

Science.gov (United States)

Hong, Qingshui; Lu, Huimin

2017-06-13

Carbon fiber papers supported Ag catalysts (Ag/CFP) with different coverage of electro-active site are prepared by electrochemical deposition and used as binder free cathodes in primary aluminum-air (Al-air) battery. Scanning Electron Microscopy and X-ray Diffraction studies are carried out to characterize the as-prepared Ag/CFP air cathodes. Oxygen reduction reaction (ORR) activities on these air cathodes in alkaline solutions are systematic studied. A newly designed aluminum-air cell is used to further determine the cathodes performance under real operation condition and during the test, the Ag/CFP electrodes show outstanding catalytic activity for ORR in concentrated alkaline electrolyte, and no obvious activity degradation is observed after long-time discharge. The electrochemical test results display the dependence of coverage of the electro-active Ag on the catalytic performance of the air cathodes. The resulting primary Al-air battery made from the best-performing cathode shows an impressive discharge peak power density, outperforming that of using commercial nano-manganese catalyst air electrodes.

Inhibition of aluminum corrosion using Opuntia extract

International Nuclear Information System (INIS)

El-Etre, A.Y.

2003-01-01

The inhibitive action of the mucilage extracted from the modified stems of prickly pears, toward acid corrosion of aluminum, is tested using weight loss, thermometry, hydrogen evolution and polarization techniques. It was found that the extract acts as a good corrosion inhibitor for aluminum corrosion in 2.0 M HCl solution. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm. It was found that the adsorption of the extract on aluminum surface is a spontaneous process. The inhibition efficiency (IE) increases as the extract concentration is increased. The effect of temperature on the IE was studied. It was found that the presence of extract increases the activation energy of the corrosion reaction. Moreover, the thermodynamic parameters of the adsorption process were calculated. It was found also that the Opuntia extract provides a good protection to aluminum against pitting corrosion in chloride ion containing solutions

First-principles surface interaction studies of aluminum-copper and aluminum-copper-magnesium secondary phases in aluminum alloys

Science.gov (United States)

da Silva, Thiago H.; Nelson, Eric B.; Williamson, Izaak; Efaw, Corey M.; Sapper, Erik; Hurley, Michael F.; Li, Lan

2018-05-01

First-principles density functional theory-based calculations were performed to study θ-phase Al2Cu, S-phase Al2CuMg surface stability, as well as their interactions with water molecules and chloride (Cl-) ions. These secondary phases are commonly found in aluminum-based alloys and are initiation points for localized corrosion. Density functional theory (DFT)-based simulations provide insight into the origins of localized (pitting) corrosion processes of aluminum-based alloys. For both phases studied, Cl- ions cause atomic distortions on the surface layers. The nature of the distortions could be a factor to weaken the interlayer bonds in the Al2Cu and Al2CuMg secondary phases, facilitating the corrosion process. Electronic structure calculations revealed not only electron charge transfer from Cl- ions to alloy surface but also electron sharing, suggesting ionic and covalent bonding features, respectively. The S-phase Al2CuMg structure has a more active surface than the θ-phase Al2Cu. We also found a higher tendency of formation of new species, such as Al3+, Al(OH)2+, HCl, AlCl2+, Al(OH)Cl+, and Cl2 on the S-phase Al2CuMg surface. Surface chemical reactions and resultant species present contribute to establishment of local surface chemistry that influences the corrosion behavior of aluminum alloys.

Monte Carlo electron-photon transport using GPUs as an accelerator: Results for a water-aluminum-water phantom

Energy Technology Data Exchange (ETDEWEB)

Su, L.; Du, X.; Liu, T.; Xu, X. G. [Nuclear Engineering Program, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States)

2013-07-01

An electron-photon coupled Monte Carlo code ARCHER - Accelerated Radiation-transport Computations in Heterogeneous Environments - is being developed at Rensselaer Polytechnic Institute as a software test bed for emerging heterogeneous high performance computers that utilize accelerators such as GPUs. In this paper, the preliminary results of code development and testing are presented. The electron transport in media was modeled using the class-II condensed history method. The electron energy considered ranges from a few hundred keV to 30 MeV. Moller scattering and bremsstrahlung processes above a preset energy were explicitly modeled. Energy loss below that threshold was accounted for using the Continuously Slowing Down Approximation (CSDA). Photon transport was dealt with using the delta tracking method. Photoelectric effect, Compton scattering and pair production were modeled. Voxelised geometry was supported. A serial ARHCHER-CPU was first written in C++. The code was then ported to the GPU platform using CUDA C. The hardware involved a desktop PC with an Intel Xeon X5660 CPU and six NVIDIA Tesla M2090 GPUs. ARHCHER was tested for a case of 20 MeV electron beam incident perpendicularly on a water-aluminum-water phantom. The depth and lateral dose profiles were found to agree with results obtained from well tested MC codes. Using six GPU cards, 6x10{sup 6} histories of electrons were simulated within 2 seconds. In comparison, the same case running the EGSnrc and MCNPX codes required 1645 seconds and 9213 seconds, respectively, on a CPU with a single core used. (authors)

Calcium-regulation of mitochondrial respiration maintains ATP homeostasis and requires ARALAR/AGC1-malate aspartate shuttle in intact cortical neurons.

Science.gov (United States)

Llorente-Folch, Irene; Rueda, Carlos B; Amigo, Ignacio; del Arco, Araceli; Saheki, Takeyori; Pardo, Beatriz; Satrústegui, Jorgina

2013-08-28

Neuronal respiration is controlled by ATP demand and Ca2+ but the roles played by each are unknown, as any Ca2+ signal also impacts on ATP demand. Ca2+ can control mitochondrial function through Ca2+-regulated mitochondrial carriers, the aspartate-glutamate and ATP-Mg/Pi carriers, ARALAR/AGC1 and SCaMC-3, respectively, or in the matrix after Ca2+ transport through the Ca2+ uniporter. We have studied the role of Ca2+ signaling in the regulation of mitochondrial respiration in intact mouse cortical neurons in basal conditions and in response to increased workload caused by increases in [Na+]cyt (veratridine, high-K+ depolarization) and/or [Ca2+]cyt (carbachol). Respiration in nonstimulated neurons on 2.5-5 mm glucose depends on ARALAR-malate aspartate shuttle (MAS), with a 46% drop in aralar KO neurons. All stimulation conditions induced increased OCR (oxygen consumption rate) in the presence of Ca2+, which was prevented by BAPTA-AM loading (to preserve the workload), or in Ca2+-free medium (which also lowers cell workload). SCaMC-3 limits respiration only in response to high workloads and robust Ca2+ signals. In every condition tested Ca2+ activation of ARALAR-MAS was required to fully stimulate coupled respiration by promoting pyruvate entry into mitochondria. In aralar KO neurons, respiration was stimulated by veratridine, but not by KCl or carbachol, indicating that the Ca2+ uniporter pathway played a role in the first, but not in the second condition, even though KCl caused an increase in [Ca2+]mit. The results suggest a requirement for ARALAR-MAS in priming pyruvate entry in mitochondria as a step needed to activate respiration by Ca2+ in response to moderate workloads.

Acoustic emission from a solidifying aluminum-lithium alloy

Science.gov (United States)

Henkel, D. P.; Wood, J. D.

1992-01-01

Physical phenomena associated with the solidification of an AA2090 Al-Li alloy have been characterized by AE methods. Repeatable patterns of AE activity as a function of solidification time are recorded and explained for ultrahigh-purity (UHP) aluminum and an Al-4.7 wt pct Cu binary alloy, in addition to the AA2090 Al-Li alloy, by the complementary utilization of thermal, AE, and metallographic methods. One result shows that the solidification of UHP aluminum produces one discrete period of high AE activity as the last 10 percent of solid forms.

Molecular and Physiological Logics of the Pyruvate-Induced Response of a Novel Transporter in Bacillus subtilis

Directory of Open Access Journals (Sweden)

Teddy Charbonnier

2017-10-01

Full Text Available At the heart of central carbon metabolism, pyruvate is a pivotal metabolite in all living cells. Bacillus subtilis is able to excrete pyruvate as well as to use it as the sole carbon source. We herein reveal that ysbAB (renamed pftAB, the only operon specifically induced in pyruvate-grown B. subtilis cells, encodes a hetero-oligomeric membrane complex which operates as a facilitated transport system specific for pyruvate, thereby defining a novel class of transporter. We demonstrate that the LytST two-component system is responsible for the induction of pftAB in the presence of pyruvate by binding of the LytT response regulator to a palindromic region upstream of pftAB. We show that both glucose and malate, the preferred carbon sources for B. subtilis, trigger the binding of CcpA upstream of pftAB, which results in its catabolite repression. However, an additional CcpA-independent mechanism represses pftAB in the presence of malate. Screening a genome-wide transposon mutant library, we find that an active malic enzyme replenishing the pyruvate pool is required for this repression. We next reveal that the higher the influx of pyruvate, the stronger the CcpA-independent repression of pftAB, which suggests that intracellular pyruvate retroinhibits pftAB induction via LytST. Such a retroinhibition challenges the rational design of novel nature-inspired sensors and synthetic switches but undoubtedly offers new possibilities for the development of integrated sensor/controller circuitry. Overall, we provide evidence for a complete system of sensors, feed-forward and feedback controllers that play a major role in environmental growth of B. subtilis.

Aluminum powder metallurgy processing

Energy Technology Data Exchange (ETDEWEB)

Flumerfelt, J.F.

1999-02-12

The objective of this dissertation is to explore the hypothesis that there is a strong linkage between gas atomization processing conditions, as-atomized aluminum powder characteristics, and the consolidation methodology required to make components from aluminum powder. The hypothesis was tested with pure aluminum powders produced by commercial air atomization, commercial inert gas atomization, and gas atomization reaction synthesis (GARS). A comparison of the GARS aluminum powders with the commercial aluminum powders showed the former to exhibit superior powder characteristics. The powders were compared in terms of size and shape, bulk chemistry, surface oxide chemistry and structure, and oxide film thickness. Minimum explosive concentration measurements assessed the dependence of explosibility hazard on surface area, oxide film thickness, and gas atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization oxidation of aluminum powder. An Al-Ti-Y GARS alloy exposed in ambient air at different temperatures revealed the effect of reactive alloy elements on post-atomization powder oxidation. The pure aluminum powders were consolidated by two different routes, a conventional consolidation process for fabricating aerospace components with aluminum powder and a proposed alternative. The consolidation procedures were compared by evaluating the consolidated microstructures and the corresponding mechanical properties. A low temperature solid state sintering experiment demonstrated that tap densified GARS aluminum powders can form sintering necks between contacting powder particles, unlike the total resistance to sintering of commercial air atomization aluminum powder.

The Oxidation Products of Aluminum Hydride and Boron Aluminum Hydride Clusters

Science.gov (United States)

2016-01-04

AFRL-AFOSR-VA-TR-2016-0075 The Oxidation Products of Aluminum Hydride and Boron Aluminum Hydride Clusters KIT BOWEN JOHNS HOPKINS UNIV BALTIMORE MD...2. REPORT TYPE Final Performance 3. DATES COVERED (From - To) 30-09-2014 to 29-09-2015 4. TITLE AND SUBTITLE The Oxidation Products of Aluminum ...Hydride and Boron Aluminum Hydride Clusters 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-14-1-0324 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) KIT

Aluminum Hydroxide

Science.gov (United States)

Aluminum hydroxide is used for the relief of heartburn, sour stomach, and peptic ulcer pain and to ... Aluminum hydroxide comes as a capsule, a tablet, and an oral liquid and suspension. The dose and ...

Activation of aluminum as an effective reducing agent by pitting corrosion for wet-chemical synthesis.

Science.gov (United States)

Li, Wei; Cochell, Thomas; Manthiram, Arumugam

2013-01-01

Metallic aluminum (Al) is of interest as a reducing agent because of its low standard reduction potential. However, its surface is invariably covered with a dense aluminum oxide film, which prevents its effective use as a reducing agent in wet-chemical synthesis. Pitting corrosion, known as an undesired reaction destroying Al and is enhanced by anions such as F⁻, Cl⁻, and Br⁻ in aqueous solutions, is applied here for the first time to activate Al as a reducing agent for wet-chemical synthesis of a diverse array of metals and alloys. Specifically, we demonstrate the synthesis of highly dispersed palladium nanoparticles on carbon black with stabilizers and the intermetallic Cu₂Sb/C, which are promising candidates, respectively, for fuel cell catalysts and lithium-ion battery anodes. Atomic hydrogen, an intermediate during the pitting corrosion of Al in protonic solvents (e.g., water and ethylene glycol), is validated as the actual reducing agent.

Application of spectral decomposition analysis to in vivo quantification of aluminum by neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Comsa, D.C. E-mail: comsadc@mcmaster.ca; Prestwich, W.V.; McNeill, F.E.; Byun, S.H

2004-12-01

The toxic effects of aluminum are cumulative and result in painful forms of renal osteodystrophy, most notably adynamic bone disease and osteomalacia, but also other forms of disease. The Trace Element Group at McMaster University has developed an accelerator-based in vivo procedure for detecting aluminum body burden by neutron activation analysis (NAA). Further refining of the method was necessary for increasing its sensitivity. In this context, the present study proposes an improved algorithm for data analysis, based on spectral decomposition. A new minimum detectable limit (MDL) of (0.7{+-}0.1) mg Al was reached for a local dose of (20{+-}1) mSv. The study also addresses the feasibility of a new data acquisition technique, the electronic rejection of the coincident events detected by a NaI(Tl) system. It is expected that the application of this technique, together with spectral decomposition analysis, would provide an acceptable MDL for the method to be valuable in a clinical setting.

Is the Aluminum Hypothesis Dead?

Science.gov (United States)

2014-01-01

The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed with concern by some of the public. This review article discusses reasons that mainstream science has largely abandoned the Aluminum Hypothesis and explores a possible reason for some in the general public continuing to view aluminum with mistrust. PMID:24806729

75 FR 70689 - Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum-Greenwood Forge Division; Currently...

Science.gov (United States)

2010-11-18

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-70,376] Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum- Greenwood Forge Division; Currently Known As Contech Forgings, LLC..., applicable to workers of Kaiser Aluminum Fabricated Products, LLC, Kaiser Aluminum-Greenwood Forge Division...

The effect of zinc on the aluminum anode of the aluminum-air battery

Science.gov (United States)

Tang, Yougen; Lu, Lingbin; Roesky, Herbert W.; Wang, Laiwen; Huang, Baiyun

Aluminum is an ideal material for batteries, due to its excellent electrochemical performance. Herein, the effect of zinc on the aluminum anode of the aluminum-air battery, as an additive for aluminum alloy and electrolytes, has been studied. The results show that zinc can decrease the anodic polarization, restrain the hydrogen evolution and increase the anodic utilization rate.

Transport of biologically active material in laser cutting.

Science.gov (United States)

Frenz, M; Mathezloic, F; Stoffel, M H; Zweig, A D; Romano, V; Weber, H P

1988-01-01

The transport of biologically active material during laser cutting with CO2 and Er lasers is demonstrated. This transport mechanism removes particles from the surface of gelatin, agar, and liver samples into the depth of the laser-formed craters. The transport phenomenon is explained by a contraction and condensation of enclosed hot water vapor. We show by cultivating transported bacteria in agar that biological particles can survive the shock of the transport. Determination of the numbers of active cells evidences a more pronounced activity of the cultivated bacteria after impact with an Er laser than with a CO2 laser.

Aluminum phosphate shows more adjuvanticity than Aluminum hydroxide in recombinant hepatitis –B vaccine formulation

Directory of Open Access Journals (Sweden)

2008-08-01

Full Text Available Background: Although a number of investigation have been carried out to find alternative adjuvants to aluminum salts in vaccine formulations, they are still extensively used due to their good track record of safety, low cost and proper adjuvanticity with a variety of antigens. Adsorption of antigens onto aluminum compounds depends heavily on electrostatic forces between adjuvant and antigen. Commercial recombinant protein hepatitis B vaccines containing aluminum hydroxide as adjuvant is facing low induction of immunity in some sections of the vaccinated population. To follow the current global efforts in finding more potent hepatitis B vaccine formulation, adjuvanticity of aluminum phosphate has been compared to aluminum hydroxide. Materials and methods: The adjuvant properties of aluminum hydroxide and aluminum phosphate in a vaccine formulation containing a locally manufactured hepatitis B (HBs surface antigen was evaluated in Balb/C mice. The formulations were administered intra peritoneally (i.p. and the titers of antibody which was induced after 28 days were determined using ELISA technique. The geometric mean of antibody titer (GMT, seroconversion and seroprotection rates, ED50 and relative potency of different formulations were determined. Results: All the adjuvanicity markers obtained in aluminum phosphate formulation were significantly higher than aluminum hydroxide. The geometric mean of antibody titer of aluminum phosphate was approximately three folds more than aluminum hydroxide. Conclusion: Aluminum phosphate showed more adjuvanticity than aluminum hydroxide in hepatitis B vaccine. Therefore the use of aluminum phosphate as adjuvant in this vaccine may lead to higher immunity with longer duration of effects in vaccinated groups.

Radioactive materials transporting container and vehicles

International Nuclear Information System (INIS)

Reese, S.L.

1980-01-01

A container and vehicle therefor for transporting radioactive materials is provided. The container utilizes a removable system of heat conducting fins made of a light weight highly heat conductive metal, such as aluminum or aluminum alloys. This permits a substantial reduction in the weight of the container during transport, increases the heat dissipation capability of the container and substantially reduces the scrubbing operation after loading and before unloading the radioactive material from the container. The vehicle utilizes only a pair of horizontal side beams interconnecting a pair of yoke members to support the container and provide the necessary strength and safety with a minimum of weight

Aluminum fin-stock alloys

International Nuclear Information System (INIS)

Gul, R.M.; Mutasher, F.

2007-01-01

Aluminum alloys have long been used in the production of heat exchanger fins. The comparative properties of the different alloys used for this purpose has not been an issue in the past, because of the significant thickness of the finstock material. However, in order to make fins lighter in weight, there is a growing demand for thinner finstock materials, which has emphasized the need for improved mechanical properties, thermal conductivity and corrosion resistance. The objective of this project is to determine the effect of iron, silicon and manganese percentage increment on the required mechanical properties for this application by analyzing four different aluminum alloys. The four selected aluminum alloys are 1100, 8011, 8079 and 8150, which are wrought non-heat treatable alloys with different amount of the above elements. Aluminum alloy 1100 serve as a control specimen, as it is commercially pure aluminum. The study also reports the effect of different annealing cycles on the mechanical properties of the selected alloys. Metallographic examination was also preformed to study the effect of annealing on the precipitate phases and the distribution of these phases for each alloy. The microstructure analysis of the aluminum alloys studied indicates that the precipitated phase in the case of aluminum alloys 1100 and 8079 is beta-FeAI3, while in 8011 it is a-alfa AIFeSi, and the aluminum alloy 8150 contains AI6(Mn,Fe) phase. The comparison of aluminum alloys 8011 and 8079 with aluminum alloy 1100 show that the addition of iron and silicon improves the percent elongation and reduces strength. The manganese addition increases the stability of mechanical properties along the annealing range as shown by the comparison of aluminum alloy 8150 with aluminum alloy 1100. Alloy 8150 show superior properties over the other alloys due to the reaction of iron and manganese, resulting in a preferable response to thermal treatment and improved mechanical properties. (author)

Effect of interfacial oxide thickness on the photocatalytic activity of magnetron-sputtered TiO2coatings on aluminum substrate

DEFF Research Database (Denmark)

Daviðsdóttir, Svava; Petit, Jean-Pierre; Shabadi, Rajashekhara

2015-01-01

The influence of the coating/substrate interface on the photocatalytic behavior of Al-TiO2 coatings was investigated. The TiO2 coatings were prepared by magnetron sputtering. The nanoscale structure of the coating was analyzed using X-ray diffraction; atomic force microscopy; scanning electron...... transport between the coating and the metallic substrate. The highest photocurrents were indeed obtained when the thickness of interfacial aluminum oxide could be reduced by sputtering a thin Ti layer prior to TiO2 coating. Photocurrent plotted for different photon energy for a TiO2 coating on a Ti...

Pyruvate transport by thermogenic-tissue mitochondria.

OpenAIRE

Proudlove, M O; Beechey, R B; Moore, A L

1987-01-01

1. Mitochondria isolated from the thermogenic spadices of Arum maculatum and Sauromatum guttatum plants oxidized external NADH, succinate, citrate, malate, 2-oxoglutarate and pyruvate without the need to add exogenous cofactors. 2. Oxidation of substrates was virtually all via the alternative oxidase, the cytochrome pathway constituting only 10-20% of the total activity, depending on the stage of spadix development. 3. During later stages of spadix development, pyruvate oxidation was enhanced...

Impact of acid atmosphere deposition on soils : field monitoring and aluminum chemistry

NARCIS (Netherlands)

Mulder, J.

1988-01-01

The effect of acid atmospheric deposition on concentrations and transfer of major solutes in acid, sandy soils was studied. Emphasis was given to mobilization and transport of potentially toxic aluminum. Data on solute concentrations and fluxes in meteoric water as well as soil solutions

Expression of the 68-kilodalton neurofilament gene in aluminum intoxication

International Nuclear Information System (INIS)

Muma, N.A.; Troncoso, J.C.; Hoffman, P.N.; Price, D.L.

1986-01-01

Intrathecal administration of aluminum salts induces accumulation of neurofilaments (NFs) in cell bodies and proximal axons of rabbit spinal motor neurons. Mechanisms leading to this pathological change are not well understood. Although impairments of NF transport have been demonstrated in this model, the hypothesis that NF accumulations are the result of an increase in NF synthesis needs to be explored. In rabbits, a large percentage of neurons develop accumulations of NFs following injections of aluminum lactate directly into the cisterna magna or into a reservoir placed in the lateral ventricle. To study levels of mRNA encoding cytoskeletal proteins, spinal cord RNA was extracted, separated on a denaturing agarose gel, transferred to nitrocellulose paper, and hybridized to [ 32 P]-labeled cDNA clones encoding the mouse 68-kilodalton (kd) NF subunit and tubulin. Examining a constant amount of RNA, the radioactivity of labeled mRNA bands for the 68-kd NF subunit and for tubulin was decreased in spinal cords of aluminum-treated rabbits. These preliminary results will be followed up by in situ hybridization to determine levels of mRNA for tubulin and 68-kd NF subunit in affected and in normal spinal neurons. In conclusion, administration of aluminum decreased mRNA for the 608-kd NF protein in spinal neurons

Investigation of Methods for Selectively Reinforcing Aluminum and Aluminum-Lithium Materials

Science.gov (United States)

Bird, R. Keith; Alexa, Joel A.; Messick, Peter L.; Domack, Marcia S.; Wagner, John A.

2013-01-01

Several studies have indicated that selective reinforcement offers the potential to significantly improve the performance of metallic structures for aerospace applications. Applying high-strength, high-stiffness fibers to the high-stress regions of aluminum-based structures can increase the structural load-carrying capability and inhibit fatigue crack initiation and growth. This paper discusses an investigation into potential methods for applying reinforcing fibers onto the surface of aluminum and aluminum-lithium plate. Commercially-available alumina-fiber reinforced aluminum alloy tapes were used as the reinforcing material. Vacuum hot pressing was used to bond the reinforcing tape to aluminum alloy 2219 and aluminum-lithium alloy 2195 base plates. Static and cyclic three-point bend testing and metallurgical analysis were used to evaluate the enhancement of mechanical performance and the integrity of the bond between the tape and the base plate. The tests demonstrated an increase in specific bending stiffness. In addition, no issues with debonding of the reinforcing tape from the base plate during bend testing were observed. The increase in specific stiffness indicates that selectively-reinforced structures could be designed with the same performance capabilities as a conventional unreinforced structure but with lower mass.

Tunable blue organic light emitting diode based on aluminum calixarene supramolecular complex

Science.gov (United States)

Legnani, C.; Reyes, R.; Cremona, M.; Bagatin, I. A.; Toma, H. E.

2004-07-01

In this letter, the results of supramolecular organic light emitting diodes using a calix[4] arene complex thin film as emitter and electron transporting layer are presented. The devices were grown onto glass substrates coated with indium-tin-oxide layer and aluminum thick (150nm) cathode. By applying a dc voltage between the device electrodes in forward bias condition, a blue light emission in the active area of the device was observed. It was found that the electroluminescent emission peak can be tuned between 470 and 510nm changing the applied voltage bias from 4.3 to 5.4V. The observed tunable emission can be associated with an energy transfer from the calixarene compound.

[The unbearable lightness of aluminum: the social and environmental impacts of Brazil's insertion in the primary aluminum global market].

Science.gov (United States)

Henriques, Alen Batista; Porto, Marcelo Firpo Souza

2013-11-01

This article assesses aluminum production in Brazil and its social, environmental and public health impacts. The effects of the aluminum production chain challenge the idea of sustainable growth affirmed by business groups that operate in the sector. This article upholds the theory that the insertion of Brazil in the global aluminum market is part of a new configuration of the International Division of Labor (IDL), the polluting economic and highly energy dependent activities of which - as is the case of aluminum - have been moving to peripheral nations or emerging countries. The laws in such countries are less stringent, and similarly the environmental movements and the claims of the affected populations in the territories prejudiced in their rights to health, a healthy environment and culture are less influential. The competitiveness of this commodity is guaranteed in the international market, from the production of external factors such as environmental damage, deforestation, emissions of greenhouse gases and scenarios of environmental injustice. This includes undertakings in the construction of hydroelectric dams that expose traditional communities to situations involving the loss of their territories.

40 CFR 180.1091 - Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Aluminum isopropoxide and aluminum... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1091 Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a tolerance. Aluminum isopropoxide (CAS Reg. No. 555...

A simple aluminum gasket for use with both stainless steel and aluminum flanges

Energy Technology Data Exchange (ETDEWEB)

Langley, R.A.

1991-01-01

A technique has been developed for making aluminum wire seal gaskets of various sizes and shapes for use with both stainless steel and aluminum alloy flanges. The gasket material used is 0.9999 pure aluminum, drawn to a diameter of 3 mm. This material can be easily welded and formed into various shapes. A single gasket has been successfully used up to five times without baking. The largest gasket tested to date is 3.5 m long and was used in the shape of a parallelogram. Previous use of aluminum wire gaskets, including results for bakeout at temperatures from 20 to 660{degree}C, is reviewed. A search of the literature indicates that this is the first reported use of aluminum wire gaskets for aluminum alloy flanges. The technique is described in detail, and the results are summarized. 11 refs., 4 figs.

Precipitation and Deposition of Aluminum-Containing Phases in Tank Wastes. Final Report

International Nuclear Information System (INIS)

Dabbs, Daniel M.; Aksay, Ilhan A.

2009-01-01

Aluminum-containing phases compose the bulk of solids precipitating during the processing of radioactive tank wastes. Processes designed to minimize the volume of high-level waste through conversion to glassy phases require transporting waste solutions near-saturated with aluminum-containing species from holding tank to processing center. The uncontrolled precipitation within transfer lines results in clogged pipes and lines and fouled ion exchangers, with the potential to shut down processing operations. The principal focus of our research was to maintain the fluidity of aluminum- or silicon-containing suspensions and solutions during transport, whether by preventing particle formation, stabilizing colloidal particles in suspension, or by combining partial dissolution with particle stabilization. We have found that all of these can be effected in aluminum-containing solutions using the simple organic, citric acid. Silicon-containing solutions were found to be less tractable, but we have strong indications that chemistries similar to the citric acid/aluminum suspensions can be effective in maintaining silicon suspensions at high alkalinities. In the first phase of our study, we focused on the use of simple organics to raise the solubility of aluminum oxyhydroxides in high alkaline aqueous solvents. In a limited survey of common organic acids, we determined that citric acid had the highest potential to achieve our goal. However, our subsequent investigation revealed that the citric acid appeared to play two roles in the solutions: first, raising the concentration of aluminum in highly alkaline solutions by breaking up or inhibiting 'seed' polycations and thereby delaying the nucleation and growth of particles; and second, stabilizing nanometer-sized particles in suspension when nucleation did occur. The second phase of our work involved the solvation of silicon, again in solutions of high alkalinity. Here, the use of polyols was determined to be effective in

Modelling of activity transport in PHWR

International Nuclear Information System (INIS)

Veena, S.N.; Rangarajan, S.; Narasimhan, S.V.; Horvath, G.L.

2000-01-01

The modelling of mass and activity transport in PHWR is of importance in predicting the build up of radiation field in and around the Primary Heat Transport system which will consequently help in planning the Dilute Chemical Decontamination and man rem budgeting. Modeling also helps in understanding the different parameters controlling the transport behaviour. Some of the important parameters include coolant chemistry like pH, physical parameters like temperature, the nature of the corrosion film and hence the effect of passivation techniques. VVER code for activity transport uses six nodes for the primary system and is essentially devised for stainless steel system. In the present work though based on this model, major modifications have been incorporated to suit the PHWR conditions. In the code, the PHT system of PHWR is suitably divided into 14 nodes, 5 in-core and 9 out of core nodes based on material and heat transfer properties. This paper describes the mechanisms involved in the various processes like generation of corrosion products, their release as well as their transport into the primary coolant, the activation of inactive corrosion product nuclides and the build up of radiation field due to 60 Co around the PHT system. (author)

Molten Triazolium Chloride Systems as New Aluminum Battery Electrolytes

DEFF Research Database (Denmark)

Vestergaard, B.; Bjerrum, Niels; Petrushina, Irina

1993-01-01

-170-degrees-C) depending on melt acidity and anode material. DMTC, being specifically adsorbed and reduced on the tungsten electrode surface, had an inhibiting effect on the aluminum reduction, but this effect was suppressed on the aluminum substrate. An electrochemical process with high current density (tens...... of milliamperes per square centimeter) was observed at 0.344 V on the acidic sodium tetrachloroaluminate background, involving a free triazolium radical mechanism. Molten DMTC-AlCl3 electrolytes are acceptable for battery performance and both the aluminum anode and the triazolium electrolyte can be used as active......The possibility of using molten mixtures of 1,4-dimethyl-1,2,4-triazolium chloride (DMTC) and aluminum chloride (AlCl3) as secondary battery electrolytes was studied, in some cases extended by the copresence of sodium chloride. DMTC-AlCl, mixtures demonstrated high specific conductivity in a wide...

Aluminum enhances inflammation and decreases mucosal healing in experimental colitis in mice

Science.gov (United States)

Pineton de Chambrun, G; Body-Malapel, M; Frey-Wagner, I; Djouina, M; Deknuydt, F; Atrott, K; Esquerre, N; Altare, F; Neut, C; Arrieta, M C; Kanneganti, T-D; Rogler, G; Colombel, J-F; Cortot, A; Desreumaux, P; Vignal, C

2014-01-01

The increasing incidence of inflammatory bowel diseases (IBDs) in developing countries has highlighted the critical role of environmental pollutants as causative factors in their pathophysiology. Despite its ubiquity and immune toxicity, the impact of aluminum in the gut is not known. This study aimed to evaluate the effects of environmentally relevant intoxication with aluminum in murine models of colitis and to explore the underlying mechanisms. Oral administration of aluminum worsened intestinal inflammation in mice with 2,4,6-trinitrobenzene sulfonic acid- and dextran sodium sulfate-induced colitis and chronic colitis in interleukin 10-negative (IL10−/−) mice. Aluminum increased the intensity and duration of macroscopic and histologic inflammation, colonic myeloperoxidase activity, inflammatory cytokines expression, and decreased the epithelial cell renewal compared with control animals. Under basal conditions, aluminum impaired intestinal barrier function. In vitro, aluminum induced granuloma formation and synergized with lipopolysaccharide to stimulate inflammatory cytokines expression by epithelial cells. Deleterious effects of aluminum on intestinal inflammation and mucosal repair strongly suggest that aluminum might be an environmental IBD risk factor. PMID:24129165

The aluminum smelting process.

Science.gov (United States)

Kvande, Halvor

2014-05-01

This introduction to the industrial primary aluminum production process presents a short description of the electrolytic reduction technology, the history of aluminum, and the importance of this metal and its production process to modern society. Aluminum's special qualities have enabled advances in technologies coupled with energy and cost savings. Aircraft capabilities have been greatly enhanced, and increases in size and capacity are made possible by advances in aluminum technology. The metal's flexibility for shaping and extruding has led to architectural advances in energy-saving building construction. The high strength-to-weight ratio has meant a substantial reduction in energy consumption for trucks and other vehicles. The aluminum industry is therefore a pivotal one for ecological sustainability and strategic for technological development.

An active matter analysis of intracellular Active Transport

Science.gov (United States)

Wang, Bo; Chen, Kejia; Bae, Sung Chul; Granick, Steve

2012-02-01

Tens of thousands of fluorescence-based trajectories at nm resolution have been analyzed, regarding active transport along microtubules in living cells. The following picture emerges. Directed motion to pre-determined locations is certainly an attractive idea, but cannot be pre-programmed as to do so would sacrifice adaptability. The polarity of microtubules is inadequate to identify these directions in cells, and no other mechanism is currently known. We conclude that molecular motors carry cargo through disordered intracellular microtubule networks in a statistical way, with loud cellular ``noise'' both in directionality and speed. Programmed random walks describe how local 1D active transport traverses crowded cellular space efficiently, rapidly, minimizing the energy waste that would result from redundant activity. The mechanism of statistical regulation is not yet understood, however.

Isoform expression in the multiple soluble malate dehydrogenase of Hoplias malabaricus (Erythrinidae, Characiformes

Directory of Open Access Journals (Sweden)

M. R. Aquino-Silva

Full Text Available Kinetic properties and thermal stabilities of Hoplias malabaricus liver and skeletal muscle unfractionated malate dehydrogenase (MDH, EC 1.1.1.37 and its isolated isoforms were analyzed to further study the possible sMDH-A* locus duplication evolved from a recent tandem duplication. Both A (A1 and A2 and B isoforms had similar optima pH (7.5-8.0. While Hoplias A isoform could not be characterized as thermostable, B could as thermolabile. A isoforms differed from B isoform in having higher Km values for oxaloacetate. The possibly duplicated A2 isoform showed higher substrate affinity than the A1. Hoplias duplicated A isoforms may influence the direction of carbon flow between glycolisis and gluconeogenesis.

Isoform expression in the multiple soluble malate dehydrogenase of Hoplias malabaricus (Erythrinidae, Characiformes

Directory of Open Access Journals (Sweden)

Aquino-Silva M. R.

2003-01-01

Full Text Available Kinetic properties and thermal stabilities of Hoplias malabaricus liver and skeletal muscle unfractionated malate dehydrogenase (MDH, EC 1.1.1.37 and its isolated isoforms were analyzed to further study the possible sMDH-A* locus duplication evolved from a recent tandem duplication. Both A (A1 and A2 and B isoforms had similar optima pH (7.5-8.0. While Hoplias A isoform could not be characterized as thermostable, B could as thermolabile. A isoforms differed from B isoform in having higher Km values for oxaloacetate. The possibly duplicated A2 isoform showed higher substrate affinity than the A1. Hoplias duplicated A isoforms may influence the direction of carbon flow between glycolisis and gluconeogenesis.

Deposition behavior of residual aluminum in drinking water distribution system: Effect of aluminum speciation.

Science.gov (United States)

Zhang, Yue; Shi, Baoyou; Zhao, Yuanyuan; Yan, Mingquan; Lytle, Darren A; Wang, Dongsheng

2016-04-01

Finished drinking water usually contains some residual aluminum. The deposition of residual aluminum in distribution systems and potential release back to the drinking water could significantly influence the water quality at consumer taps. A preliminary analysis of aluminum content in cast iron pipe corrosion scales and loose deposits demonstrated that aluminum deposition on distribution pipe surfaces could be excessive for water treated by aluminum coagulants including polyaluminum chloride (PACl). In this work, the deposition features of different aluminum species in PACl were investigated by simulated coil-pipe test, batch reactor test and quartz crystal microbalance with dissipation monitoring. The deposition amount of non-polymeric aluminum species was the least, and its deposition layer was soft and hydrated, which indicated the possible formation of amorphous Al(OH)3. Al13 had the highest deposition tendency, and the deposition layer was rigid and much less hydrated, which indicated that the deposited aluminum might possess regular structure and self-aggregation of Al13 could be the main deposition mechanism. While for Al30, its deposition was relatively slower and deposited aluminum amount was relatively less compared with Al13. However, the total deposited mass of Al30 was much higher than that of Al13, which was attributed to the deposition of particulate aluminum matters with much higher hydration state. Compared with stationary condition, stirring could significantly enhance the deposition process, while the effect of pH on deposition was relatively weak in the near neutral range of 6.7 to 8.7. Copyright © 2015. Published by Elsevier B.V.

Production of aluminum metal by electrolysis of aluminum sulfide

Science.gov (United States)

Minh, Nguyen Q.; Loutfy, Raouf O.; Yao, Neng-Ping

1984-01-01

Production of metallic aluminum by the electrolysis of Al.sub.2 S.sub.3 at 700.degree.-800.degree. C. in a chloride melt composed of one or more alkali metal chlorides, and one or more alkaline earth metal chlorides and/or aluminum chloride to provide improved operating characteristics of the process.

Development of new low activation aluminum alloys for fusion devices

International Nuclear Information System (INIS)

Kamada, Kohji; Kakihana, Hidetake.

1985-01-01

As the materials for the R facility (a tokamak nuclear fusion device in the R project intended for D-T burning) in the Institute of Plasma Physics, Nagoya University, Al-4 % Mg-0.2 % Bi (5083 improved type) and Al-4 % Mg-1 % Li, aimed at low radioactivability, high electric resistance and high strength, have been developed. The results of the nuclear properties evaluation with 14 MeV neutrons and of the measurements of electric resistance and mechanical properties were satisfactory. The possibility of producing large Al-4 % Mg-1 % Li plate (1 m x 2 m x 25 mm) in the existing factory was confirmed, with the properties retained. The electric resistances were higher than those in the conventional aluminum alloys, and still with feasibility for the further improvement. General properties of the fusion aluminum alloys and the 26 Al formation in (n, 2n) reaction were studied. (Mori, K.)

Cytosolic nucleotides block and regulate the Arabidopsis vacuolar anion channel AtALMT9.

Science.gov (United States)

Zhang, Jingbo; Martinoia, Enrico; De Angeli, Alexis

2014-09-12

The aluminum-activated malate transporters (ALMTs) form a membrane protein family exhibiting different physiological roles in plants, varying from conferring tolerance to environmental Al(3+) to the regulation of stomatal movement. The regulation of the anion channels of the ALMT family is largely unknown. Identifying intracellular modulators of the activity of anion channels is fundamental to understanding their physiological functions. In this study we investigated the role of cytosolic nucleotides in regulating the activity of the vacuolar anion channel AtALMT9. We found that cytosolic nucleotides modulate the transport activity of AtALMT9. This modulation was based on a direct block of the pore of the channel at negative membrane potentials (open channel block) by the nucleotide and not by a phosphorylation mechanism. The block by nucleotides of AtALMT9-mediated currents was voltage dependent. The blocking efficiency of intracellular nucleotides increased with the number of phosphate groups and ATP was the most effective cellular blocker. Interestingly, the ATP block induced a marked modification of the current-voltage characteristic of AtALMT9. In addition, increased concentrations of vacuolar anions were able to shift the ATP block threshold to a more negative membrane potential. The block of AtALMT9-mediated anion currents by ATP at negative membrane potentials acts as a gate of the channel and vacuolar anion tune this gating mechanism. Our results suggest that anion transport across the vacuolar membrane in plant cells is controlled by cytosolic nucleotides and the energetic status of the cell. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Cytosolic Nucleotides Block and Regulate the Arabidopsis Vacuolar Anion Channel AtALMT9*

Science.gov (United States)

Zhang, Jingbo; Martinoia, Enrico; De Angeli, Alexis

2014-01-01

The aluminum-activated malate transporters (ALMTs) form a membrane protein family exhibiting different physiological roles in plants, varying from conferring tolerance to environmental Al3+ to the regulation of stomatal movement. The regulation of the anion channels of the ALMT family is largely unknown. Identifying intracellular modulators of the activity of anion channels is fundamental to understanding their physiological functions. In this study we investigated the role of cytosolic nucleotides in regulating the activity of the vacuolar anion channel AtALMT9. We found that cytosolic nucleotides modulate the transport activity of AtALMT9. This modulation was based on a direct block of the pore of the channel at negative membrane potentials (open channel block) by the nucleotide and not by a phosphorylation mechanism. The block by nucleotides of AtALMT9-mediated currents was voltage dependent. The blocking efficiency of intracellular nucleotides increased with the number of phosphate groups and ATP was the most effective cellular blocker. Interestingly, the ATP block induced a marked modification of the current-voltage characteristic of AtALMT9. In addition, increased concentrations of vacuolar anions were able to shift the ATP block threshold to a more negative membrane potential. The block of AtALMT9-mediated anion currents by ATP at negative membrane potentials acts as a gate of the channel and vacuolar anion tune this gating mechanism. Our results suggest that anion transport across the vacuolar membrane in plant cells is controlled by cytosolic nucleotides and the energetic status of the cell. PMID:25028514

Scaling with toroidal current of impurity transport in ATC

International Nuclear Information System (INIS)

Marmar, E.S.; Cohen, S.A.; Cecchi, J.L.

1976-06-01

An experiment measuring the scaling with changing plasma conditions of a parameter characteristic of the transport of aluminum injected into the ATC tokamak is discussed. This parameter is the time after injection at which the photon signal from Al XI reaches its maximum. It is found that the data are in agreement with the predictions of a computer code which uses neoclassical theory in the Pfirsch-Schluter regime. An approximate model describing impurity transport in ATC is also presented. This model is utilized to calculate the expected scaling with current of the aluminum transport assuming classical, neoclassical and pseudoclassical forms for the diffusion coefficient. The data are in agreement with both the neoclassical and pseudoclassical results from this model

Health Impacts of Active Transportation in Europe.

Science.gov (United States)

Rojas-Rueda, David; de Nazelle, Audrey; Andersen, Zorana J; Braun-Fahrländer, Charlotte; Bruha, Jan; Bruhova-Foltynova, Hana; Desqueyroux, Hélène; Praznoczy, Corinne; Ragettli, Martina S; Tainio, Marko; Nieuwenhuijsen, Mark J

2016-01-01

Policies that stimulate active transportation (walking and bicycling) have been related to heath benefits. This study aims to assess the potential health risks and benefits of promoting active transportation for commuting populations (age groups 16-64) in six European cities. We conducted a health impact assessment using two scenarios: increased cycling and increased walking. The primary outcome measure was all-cause mortality related to changes in physical activity level, exposure to fine particulate matter air pollution with a diameter Paris, Prague, and Warsaw. All scenarios produced health benefits in the six cities. An increase in bicycle trips to 35% of all trips (as in Copenhagen) produced the highest benefits among the different scenarios analysed in Warsaw 113 (76-163) annual deaths avoided, Prague 61 (29-104), Barcelona 37 (24-56), Paris 37 (18-64) and Basel 5 (3-9). An increase in walking trips to 50% of all trips (as in Paris) resulted in 19 (3-42) deaths avoided annually in Warsaw, 11(3-21) in Prague, 6 (4-9) in Basel, 3 (2-6) in Copenhagen and 3 (2-4) in Barcelona. The scenarios would also reduce carbon dioxide emissions in the six cities by 1,139 to 26,423 (metric tonnes per year). Policies to promote active transportation may produce health benefits, but these depend of the existing characteristics of the cities. Increased collaboration between health practitioners, transport specialists and urban planners will help to introduce the health perspective in transport policies and promote active transportation.

BONDING ALUMINUM METALS

Science.gov (United States)

Noland, R.A.; Walker, D.E.

1961-06-13

A process is given for bonding aluminum to aluminum. Silicon powder is applied to at least one of the two surfaces of the two elements to be bonded, the two elements are assembled and rubbed against each other at room temperature whereby any oxide film is ruptured by the silicon crystals in the interface; thereafter heat and pressure are applied whereby an aluminum-silicon alloy is formed, squeezed out from the interface together with any oxide film, and the elements are bonded.

Evaluation of water chemistry on the pitting susceptibility of aluminum

International Nuclear Information System (INIS)

Chandler, G.T.; Sindelar, R.L.; Lam, P.S.

1997-01-01

Aluminum-clad spent nuclear fuels are being stored in water in the Receiving Basin for Off-site Fuels (RBOF) and the reactor disassembly (cooling) basins at the Savannah River Site (SRS). Experience shows that fuels stored in water are subject to rapid pitting corrosion if the water quality is poor. Upgrade projects and actions, including those to improve water quality, were recently undertaken to upgrade the disassembly basins for extended storage. A technical strategy was developed for continued basin storage of aluminum-clad fuel assemblies. The strategy includes development and implementation of basin technical standards for water quality to minimize attack due to pitting corrosion over a desired storage period. In the absence of localized corrosion, only slow, general corrosion of the cladding would be expected. A laboratory corrosion program is being performed to provide the bases for technical standards by identifying the region of aggressive water qualities where existing oxide films would tend to break down and pits would initiate and remain active. Initial results from corrosion potential and cyclic polarization testing of aluminum alloys in various water chemistries have shown that low conductivity water (< 50 μS/cm) should not be aggressive to cause self-pitting corrosion. Initial results from tests of 8001 and 5052 aluminum and aluminium-10% uranium alloy indicate that a strong galvanic couple should not exist between the aluminum cladding materials and the aluminum-uranium fuel. Additional laboratory testing will include immersion testing to allow characterization of the growth rate of active pits to benchmark a kinetic model. This model will form the basis for a water quality technical standard and enable prediction of the life of aluminum-clad spent nuclear fuels in basin storage

The Advanced Aluminum Nitride Synthesis Methods and Its Applications: Patent Review.

Science.gov (United States)

Shishkin, Roman A; Elagin, Andrey A; Mayorova, Ekaterina S; Beketov, Askold R

2016-01-01

High purity nanosized aluminum nitride synthesis is a current issue for both industry and science. However, there is no up-to-date review considering the major issues and the technical solutions for different methods. This review aims to investigate the advanced methods of aluminum nitride synthesis and its development tendencies. Also the aluminum nitride application patents and prospects for development of the branch have been considered. The patent search on "aluminum nitride synthesis" has been carried out. The research activity has been analyzed. Special attention has been paid to the patenting geography and the leading researchers in aluminum nitride synthesis. Aluminum nitride synthesis methods have been divided into 6 main groups, the most studied approaches are carbothermal reduction (88 patents) and direct nitridation (107 patents). The current issues for each group have been analyzed; the main trends are purification of the final product and nanopowder synthesis. The leading researchers in aluminum nitride synthesis have represented 5 countries, namely: Japan, China, Russia, South Korea and USA. The main aluminum nitride application spheres are electronics (59,1 percent of applications) and new materials manufacturing (30,9 percent). The review deals with the state of the art data in nanosized aluminum nitride synthesis, the major issues and the technical solutions for different synthesis methods. It gives a full understanding of the development tendencies and of the current leaders in the sphere.

Porous aluminum room temperature anodizing process in a fluorinated-oxalic acid solution

Science.gov (United States)

Dhahri, S.; Fazio, E.; Barreca, F.; Neri, F.; Ezzaouia, H.

2016-08-01

Anodizing of aluminum is used for producing porous insulating films suitable for different applications in electronics and microelectronics. Porous-type aluminum films are most simply realized by galvanostatic anodizing in aqueous acidic solutions. The improvement in application of anodizing technique is associated with a substantial reduction of the anodizing voltage at appropriate current densities as well as to the possibility to carry out the synthesis process at room temperature in order to obtain a self-planarizing dielectric material incorporated in array of super-narrow metal lines. In this work, the anodizing of aluminum to obtain porous oxide was carried out, at room temperature, on three different substrates (glass, stainless steel and aluminum), using an oxalic acid-based electrolyte with the addition of a relatively low amount of 0.4 % of HF. Different surface morphologies, from nearly spherical to larger porous nanostructures with smooth edges, were observed by means of scanning electron microscopy. These evidences are explained by considering the formation, transport and adsorption of the fluorine species which react with the Al3+ ions. The behavior is also influenced by the nature of the original substrate.

Determination of malation, methidathion, and chlorpyrifos ethyl pesticides using acetylcholinesterase biosensor based on Nafion/Ag@rGO-NH_2 nanocomposites

International Nuclear Information System (INIS)

Guler, Muhammet; Turkoglu, Vedat; Basi, Zehra

2017-01-01

Herein, a facile electrochemical acetylcholinesterase (EC 3.1.1.7; AChE) biosensor based on nafion (NA) and Ag nanoparticles supported on amine functionalized reduced graphene oxide (rGO-NH_2) was developed. The Ag@rGO-NH_2 nanocomposite was characterized using Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). After being optimized, the biosensor exhibited excellent electrochemical response to the oxidation of thiocholine, the hydrolysis product of acetylthiocholine chloride (ATCl) catalyzed by AChE. An apparent Michealis-Menten value of 20.5 μM was obtained. Under optimized conductions, the biosensor detected malation, methidathion, and chlorpyrifos ethyl in the linear range from 0.0063 to 0.077 μg/mL, from 0.012 to 0.105 μg/mL, and from 0.021 to 0.122 μg/mL, respectively. The detection limit (LoD) was 4.5 ng/mL for malation, 9.5 ng/mL for methidathion, and 14 ng/mL for chlorpyrifos ethyl. Also, the NA/Ag@rGO-NH_2/AChE/GCE biosensor showed god sensitivity, stability and repeatability, which provides a promising tool for the detection of organophosphate pesticides.

Aluminum-Industry of the Future; Industrial Partnerships: Advancing Energy and Environmental Goals

International Nuclear Information System (INIS)

Jones, A.

2001-01-01

This tri-fold brochure describe the partnering activities of the Office of Industrial Technologies' (OIT) Industries of the Future (IOF) for Aluminum. Information on what works for the Aluminum industry, examples of successful partnerships, and benefits of partnering with OIT are included

Borated aluminum alloy manufacturing technology

International Nuclear Information System (INIS)

Shimojo, Jun; Taniuchi, Hiroaki; Kajihara, Katsura; Aruga, Yasuhiro

2003-01-01

Borated aluminum alloy is used as the basket material of cask because of its light weight, thermal conductivity and superior neutron absorbing abilities. Kobe Steel has developed a unique manufacturing process for borated aluminum alloy using a vacuum induction melting method. In this process, aluminum alloy is melted and agitated at higher temperatures than common aluminum alloy fabrication methods. It is then cast into a mold in a vacuum atmosphere. The result is a high quality aluminum alloy which has a uniform boron distribution and no impurities. (author)

Enhancing phosphorus release from waste activated sludge containing ferric or aluminum phosphates by EDTA addition during anaerobic fermentation process.

Science.gov (United States)

Zou, Jinte; Zhang, Lili; Wang, Lin; Li, Yongmei

2017-03-01

The effect of ethylene diamine tetraacetic acid (EDTA) addition on phosphorus release from biosolids and phosphate precipitates during anaerobic fermentation was investigated. Meanwhile, the impact of EDTA addition on the anaerobic fermentation process was revealed. The results indicate that EDTA addition significantly enhanced the release of phosphorus from biosolids, ferric phosphate precipitate and aluminum phosphate precipitate during anaerobic fermentation, which is attributed to the complexation of metal ions and damage of cell membrane caused by EDTA. With the optimal EDTA addition of 19.5 mM (0.41 gEDTA/gSS), phosphorus release efficiency from biosolids was 82%, which was much higher than that (40%) without EDTA addition. Meanwhile, with 19.5 mM EDTA addition, almost all the phosphorus in ferric phosphate precipitate was released, while only 57% of phosphorus in aluminum phosphate precipitate was released. This indicates that phosphorus in ferric phosphate precipitate was much easier to be released than that in aluminum phosphate precipitate during anaerobic fermentation of sludge. In addition, proper EDTA addition facilitated the production of soluble total organic carbon and volatile fatty acids, as well as solid reduction during sludge fermentation, although methane production could be inhibited. Therefore, EDTA addition can be used as an alternative method for recovering phosphorus from waste activated sludge containing ferric or aluminum precipitates, as well as recovery of soluble carbon source. Copyright © 2016 Elsevier Ltd. All rights reserved.

21 CFR 73.1645 - Aluminum powder.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum. It...

Effects of a Danish multicomponent physical activity intervention on active school transport

DEFF Research Database (Denmark)

Breum, Lars; Toftager, Mette; Ersbøll, Annette K.

2014-01-01

activity, active transport and after-school fitness program. Transport mode to school was assessed through a 5-day transportation diary. Results The proportion of active transport was high at baseline (86.0%) and was maintained at the two-year follow-up (87.0%). There was no difference in active travel...... between the intervention and the comparison schools after the intervention, but more students perceived parental encouragement and had a positive attitude towards bicycling at the intervention schools. This difference was however only borderline significant. Conclusion The prevalence of AST was high...... at both baseline and follow-up, but no difference between the intervention and comparison schools was detected. Future intervention research should ensure a high degree of involvement of students, teachers and parents, focus merely on AST and take advantage of already planned physical environment changes...

ALUMINUM BOX BUNDLING PRESS

Directory of Open Access Journals (Sweden)

Iosif DUMITRESCU

2015-05-01

Full Text Available In municipal solid waste, aluminum is the main nonferrous metal, approximately 80- 85% of the total nonferrous metals. The income per ton gained from aluminum recuperation is 20 times higher than from glass, steel boxes or paper recuperation. The object of this paper is the design of a 300 kN press for aluminum box bundling.

Determination of trace aluminum concentration and homogeneity in biological material TORT-1 by instrumental neutron activation and graphite furnace atomic absorption spectrometry

International Nuclear Information System (INIS)

Kratochvil, B.; Motkosky, N.; Duke, M.J.M.; Ng, D.

1987-01-01

The biological reference material TORT-1, lobster hepatopancreas, was analyzed for aluminum by instrumental neutron activation analysis (INAA) and graphite furnace atomic absorption spectroscopy (GFAAS). After correction of the INAA results for interferences from 28 Al produced by 31 P(n,α) 28 Al and 28 (n,p) 28 Al reactions, and use of HNO 3 plus HF for sample dissolution for the GFAAS analyses, the methods gave similar results of 43 ± 3 and 42 ± 2 μg/g respectively for 200 to 300-mg test portions. Analysis of six portions from each of six bottles of TORT-1 showed no statistical difference at the 95% confidence level for the between and within bottle variances. Therefore, The material can be considered homogeneous for aluminum if 200- to 300-mg test portions are taken. The variance was greater and the average lower when 30-mg test portions were analyzed for aluminum by GFAAS. The pattern of the results, together with the need for HF in the dissolution procedure, suggests the presence of aluminum-containing microparticulate mineral matter, perhaps silicate material, in the material

Determination of trace aluminum concentration and homogeneity in biological material TORT-1 by instrumental neutron activation and graphite furnace atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Kratochvil, B; Motkosky, N; Duke, M J.M.; Ng, D

1987-05-01

The biological reference material TORT-1, lobster hepatopancreas, was analyzed for aluminum by instrumental neutron activation analysis (INAA) and graphite furnace atomic absorption spectroscopy (GFAAS). After correction of the INAA results for interferences from /sup 28/Al produced by /sup 31/P(n,..cap alpha..)/sup 28/Al and /sup 28/(n,p)/sup 28/Al reactions, and use of HNO/sub 3/ plus HF for sample dissolution for the GFAAS analyses, the methods gave similar results of 43 +- 3 and 42 +- 2 ..mu..g/g respectively for 200 to 300-mg test portions. Analysis of six portions from each of six bottles of TORT-1 showed no statistical difference at the 95% confidence level for the between and within bottle variances. Therefore, The material can be considered homogeneous for aluminum if 200- to 300-mg test portions are taken. The variance was greater and the average lower when 30-mg test portions were analyzed for aluminum by GFAAS. The pattern of the results, together with the need for HF in the dissolution procedure, suggests the presence of aluminum-containing microparticulate mineral matter, perhaps silicate material, in the material.

Health Impacts of Active Transportation in Europe.

Directory of Open Access Journals (Sweden)

David Rojas-Rueda

Full Text Available Policies that stimulate active transportation (walking and bicycling have been related to heath benefits. This study aims to assess the potential health risks and benefits of promoting active transportation for commuting populations (age groups 16-64 in six European cities. We conducted a health impact assessment using two scenarios: increased cycling and increased walking. The primary outcome measure was all-cause mortality related to changes in physical activity level, exposure to fine particulate matter air pollution with a diameter <2.5 μm, as well as traffic fatalities in the cities of Barcelona, Basel, Copenhagen, Paris, Prague, and Warsaw. All scenarios produced health benefits in the six cities. An increase in bicycle trips to 35% of all trips (as in Copenhagen produced the highest benefits among the different scenarios analysed in Warsaw 113 (76-163 annual deaths avoided, Prague 61 (29-104, Barcelona 37 (24-56, Paris 37 (18-64 and Basel 5 (3-9. An increase in walking trips to 50% of all trips (as in Paris resulted in 19 (3-42 deaths avoided annually in Warsaw, 11(3-21 in Prague, 6 (4-9 in Basel, 3 (2-6 in Copenhagen and 3 (2-4 in Barcelona. The scenarios would also reduce carbon dioxide emissions in the six cities by 1,139 to 26,423 (metric tonnes per year. Policies to promote active transportation may produce health benefits, but these depend of the existing characteristics of the cities. Increased collaboration between health practitioners, transport specialists and urban planners will help to introduce the health perspective in transport policies and promote active transportation.

Final Technical Report Transport Task Force Activities

International Nuclear Information System (INIS)

P.W. Terry

2006-01-01

The Transport Task Force has functioned as the primary scientific organization in the area of magnetic-fusion confinement and transport since its inception in 1988. It has defined and set research directions, coordinated broad research efforts, advocated new funding initiatives, and created a highly successful and widely admired interactive culture between experiment, theory and modeling. The Transport Task Force carries out its activities under the direction of its chair and the Executive Committee. The Executive Committee is comprised of the leaders and deputy leaders of the scientific working groups. The working groups are structured and organized according to research needs and priorities and have been organized around the areas of Core Transport, H Mode and Pedestal, Fast Particle Transport, Transient Transport Phenomena, and Modeling and Simulation. A steering committee provides advise on TTF activities. Further information on the working groups and the structure and management of the TTF can be found at http://psfcwww2.psfc.mit.edu/ttf/index.html. The TTF holds an annual workshop. A summary of the workshops held during the period of this report is given in Appendix I. During the period of this report the Transport Task Force was involved in several significant activities. Foremost of these was a sweeping review of the status of transport science, the key research tasks for progress during the next 5-10 years, and a proposal for a funding initiative to ensure application of adequate resources to these problems. The conclusions of this study were incorporated into a white paper, which is copied below in Appendix II. Other significant activities have included the introduction of an extended, ongoing discussion on verification and validation as a requisite for defining and codifying the path toward predictive capability, the orchestration of a gradual shift of focus from ion thermal confinement to electron thermal confinement, and a joining of efforts on edge

Mechanical properties of composite coatings of chromium and nanodiamonds on aluminum

Directory of Open Access Journals (Sweden)

Gidikova Nelly

2018-01-01

Full Text Available Aluminum offers engineers weight saving advantages in their product design. However, aluminum has poor wear and friction properties. In addition, the surface oxide layer of this chemically active metal, which gives it the corrosion resistance, makes it a very difficult metal to plate [1]. Specific pre-treatment must be applied to remove the oxide layer from the aluminum surface. The nanodiamond particles additionally facilitates the process of chromium deposition. The object of this study is to evaluate the impact of nanodiamonds on the mechanical properties of the chromium coating plated on

Influence of coolant pH on corrosion of 6061 aluminum under reactor heat transfer conditions

International Nuclear Information System (INIS)

Pawel, S.J.; Felde, D.K.; Pawel, R.E.

1995-10-01

To support the design of the Advanced Neutron Source (ANS), an experimental program was conducted wherein aluminum alloy specimens were exposed at high heat fluxes to high-velocity aqueous coolants in a corrosion test loop. The aluminum alloys selected for exposure were candidate fuel cladding materials, and the loop system was constructed to emulate the primary coolant system for the proposed ANS reactor. One major result of this program has been the generation of an experimental database defining oxide film growth on 6061 aluminum alloy cladding. Additionally, a data correlation was developed from the database to permit the prediction of film growth for any reasonable thermal-hydraulic excursion. This capability was utilized effectively during the conceptual design stages of the reactor. During the course of this research, it became clear that the kinetics of film growth on the aluminum alloy specimens were sensitively dependent on the chemistry of the aqueous coolant and that relatively small deviations from the intended pH 5 operational level resulted in unexpectedly large changes in the corrosion behavior. Examination of the kinetic influences and the details of the film morphology suggested that a mechanism involving mass transport from other parts of the test loop was involved. Such a mechanism would also be expected to be active in the operating reactor. This report emphasizes the results of experiments that best illustrate the influence of the nonthermal-hydraulic parameters on film growth and presents data to show that comparatively small variations in pH near 5.0 invoke a sensitive response. Simply, for operation in the temperature and heat flux range appropriate for the ANS studies, coolant pH levels from 4.5 to 4.9 produced significantly less film growth than those from pH 5.1 to 6. A mechanism for this behavior based on the concept of treating the entire loop as an active corrosion system is presented

Progress in Aluminum Electrolysis Control and Future Direction for Smart Aluminum Electrolysis Plant

Science.gov (United States)

Zhang, Hongliang; Li, Tianshuang; Li, Jie; Yang, Shuai; Zou, Zhong

2017-02-01

The industrial aluminum reduction cell is an electrochemistry reactor that operates under high temperatures and highly corrosive conditions. However, these conditions have restricted the measurement of key control parameters, making the control of aluminum reduction cells a difficult problem in the industry. Because aluminum electrolysis control systems have a significant economic influence, substantial research has been conducted on control algorithms, control systems and information systems for aluminum reduction cells. This article first summarizes the development of control systems and then focuses on the progress made since 2000, including alumina concentration control, temperature control and electrolyte molecular ratio control, fault diagnosis, cell condition prediction and control system expansion. Based on these studies, the concept of a smart aluminum electrolysis plant is proposed. The frame construction, key problems and current progress are introduced. Finally, several future directions are discussed.

Protective Performance of Polyaniline-Sulfosalicylic Acid/Epoxy Coating for 5083 Aluminum

Science.gov (United States)

Liu, Suyun; Liu, Li; Meng, Fandi; Li, Ying; Wang, Fuhui

2018-01-01

Epoxy coatings incorporating different content of sulfosalicylic acid doped polyaniline (PANI-SSA) have been investigated for corrosion protection of 5083 aluminum alloy in 3.5% NaCl solution. The performance of the coatings is studied using a combination of electrochemical impedance spectroscopy (EIS), open circuit potential (OCP), gravimetric tests, adhesion tests, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results demonstrate that the content of PANI-SSA not only affects the coating compactness and the transportation of aggressive medium, but also has a significant influence on the-based aluminum. The coating with 2 wt. % PANI-SSA exhibits the best corrosion inhibition due to its good protective properties and the formation of a complete PANI-SSA induced oxide layer. PMID:29438304

Study on combined polishing process of aspherical aluminum mirrors

Science.gov (United States)

Deng, Jinqiu; Peng, Xiaoqiang; Hu, Hao; Ge, Kunpeng

2017-10-01

The aluminum mirrors are widely used as important optical components in some vital fields such as astronomical instruments or military installations due to the unique advantages of aluminum alloy. In order to simplify the structure of optical system and improve the performance at the same time, it's a tendency that the optics will be designed to aspherical or other freeform shapes. However, the traditional techniques are falling to have adequate abilities to deal with the increasing demands of aluminum optics. For example, the tool marks leaved on the surface from single point diamond turning (SPDT) has obvious adverse effects to optical system. The deterministic and sub-aperture polishing process has showed the potential to fabricate complex shapes over the few years. But it's still recognized as a problem to polish bare aluminum directly because of its soft surface and active chemical characteristics. Therefore, a combination of magnetorheological finishing (MRF) and small tool polishing (STP) is applied to obtain high performance aluminum optics in this paper. A paraboloid aluminum mirror was polished with this proposed method, and the results showed that the surface texture of the sample is restrained from rms 0.409λ (λ=632.8nm) to rms 0.025λ, and the surface roughness is improved from average Ra 6 7nm to Ra 3 4nm.

Collaboration between physical activity researchers and transport planners

DEFF Research Database (Denmark)

Crist, Katie; Bolling, Khalisa; Schipperijn, Jasper

2018-01-01

Collaboration between physical activity (PA) researchers and transport planners is a recommended strategy to combat the physical inactivity epidemic. Data collected by PA researchers could be used to identify, implement and evaluate active transport (AT) projects. However, despite aligned interests......, researchers and transport planners rarely collaborate. This study utilized qualitative methods to 1) gain an in-depth understanding of the data utilized in AT planning, 2) explore the utility of Global Positioning Systems (GPS) and accelerometer data in supporting the planning process, 3) identify...... expertise in health or transport planning. A thematic analysis was conducted following structural coding by two researchers. The analysis revealed that geographic and physical activity data that are current, local, objective and specific to individual AT trips would improve upon currently available data...

Research of plating aluminum and aluminum foil on internal surface of carbon fiber composite material centrifuge rotor drum

International Nuclear Information System (INIS)

Lu Xiuqi; Dong Jinping; Dai Xingjian

2014-01-01

In order to improve the corrosion resistance, thermal conductivity and sealability of the internal surface of carbon fiber/epoxy composite material centrifuge rotor drum, magnetron sputtering aluminum and pasting an aluminum foil on the inner wall of the drum are adopted to realize the aim. By means of XRD, SEM/EDS and OM, the surface topography of aluminum coated (thickness of 5 μm and 12 μm) and aluminum foil (12 μm) are observed and analyzed; the cohesion of between aluminum coated (or aluminum foil) and substrate material (CFRP) is measured by scratching experiment, direct drawing experiment, and shear test. Besides, the ultra-high-speed rotation experiment of CFRP ring is carried out to analyze stress and strain of coated aluminum (or aluminum foil) which is adhered on the ring. The results showed aluminum foil pasted on inner surface do better performance than magnetron sputtering aluminum on CFRP centrifuge rotor drum. (authors)

Aluminium toxicity tolerance in crop plants: Present status of research

African Journals Online (AJOL)

... tolerance of which genes of the Aluminium-activated malate transporter (ALMT) and multidrug and toxic compound extrusion (MATE) families are prominent. In this review, the progress of research in identifying aluminium toxicity tolerant genes is discussed. Keywords: Aluminium toxicity, soil acidity, hydroponic screening, ...

Modelling activity transport behavior in PWR plant

International Nuclear Information System (INIS)

Henshaw, Jim; McGurk, John; Dickinson, Shirley; Burrows, Robert; Hinds, Kelvin; Hussey, Dennis; Deshon, Jeff; Barrios Figueras, Joan Pau; Maldonado Sanchez, Santiago; Fernandez Lillo, Enrique; Garbett, Keith

2012-09-01

The activation and transport of corrosion products around a PWR circuit is a major concern to PWR plant operators as these may give rise to high personnel doses. The understanding of what controls dose rates on ex-core surfaces and shutdown releases has improved over the years but still several questions remain unanswered. For example the relative importance of particle and soluble deposition in the core to activity levels in the plant is not clear. Wide plant to plant and cycle to cycle variations are noted with no apparent explanations why such variations are observed. Over the past few years this group have been developing models to simulate corrosion product transport around a PWR circuit. These models form the basis for the latest version of the BOA code and simulate the movement of Fe and Ni around the primary circuit. Part of this development is to include the activation and subsequent transport of radioactive species around the circuit and this paper describes some initial modelling work in this area. A simple model of activation, release and deposition is described and then applied to explain the plant behaviour at Sizewell B and Vandellos II. This model accounts for activation in the core, soluble and particulate activity movement around the circuit and for activity capture ex-core on both the inner and outer oxides. The model gives a reasonable comparison with plant observations and highlights what controls activity transport in these plants and importantly what factors can be ignored. (authors)

Protective effect of ashwagandha (Withania somnifera against neurotoxicity induced by aluminum chloride in rats

Directory of Open Access Journals (Sweden)

Mohamed E Elhadidy

2018-01-01

Full Text Available Objective: To evaluate the neuroprotective effect of ashwagandha extract against aluminum chloride-induced neurotoxicity in rats. Methods: Rats were divided into control, aluminum-intoxicated rats treated daily with aluminum trichloride (AlCl3 (100 mg/kg, orally for 30 d and aluminum-intoxicated animals protected by receiving daily ashwagandha extract (200 mg/kg, orally one hour before AlCl3 administration for 30 d. Levels of lipid peroxidation, nitric oxide, reduced glutathione and tumor necrosis factor-α were measured in the cortex, hippocampus and striatum. In addition, the activities of Na+, K+, ATPase and acetylcholinesterase were determined in the three studied brain regions. Results: Aluminum increased the levels of lipid peroxidation and nitric oxide in the cortex, hippocampus and striatum and decreased the reduced glutathione level in the hippocampus and striatum. In rats protected with ashwagandha extract, non significant changes were observed in lipid peroxidation, nitric oxide and reduced glutathione. In addition, ashwagandha extracts prevented the increased activity of acetylcholinesterase and Na+, K+, ATPase induced by AlCl3 in the cortex, hippocampus and striatum. The present findings also showed that the significant increase in tumor necrosis factor-α induced by AlCl3 in the cortex and hippocampus was prevented by ashwagandha extract. Conclusions: The present results suggest that ashwagandha extract possesses antioxidant and anti-inflammatory effects against aluminum neurotoxicity. In addition, ashwagandha extract could prevent the decline in cholinergic activity by maintaining normal acetylcholinesterase activity. The later effect could recommend the use of ashwagandha as a memory enhancer.

Coordination Structure of Aluminum in Magnesium Aluminum Hydroxide Studied by 27Al NMR

Institute of Scientific and Technical Information of China (English)

无

2003-01-01

The coordination structure of aluminum in magnesium aluminum hydroxide was studiedby 27Al NMR. The result showed that tetrahedral aluminum (AlⅣ) existed in magnesiumaluminum hydroxide, and the contents of AlⅣ increased with the increase of the ratio of Al/Mg andwith the peptizing temperature. AlⅣ originated from the so-called Al13 polymer with the structureof one Al tetrahedron surrounded by twelve Al octahedrons.

Air-Impregnated Nanoporous Anodic Aluminum Oxide Layers for Enhancing the Corrosion Resistance of Aluminum.

Science.gov (United States)

Jeong, Chanyoung; Lee, Junghoon; Sheppard, Keith; Choi, Chang-Hwan

2015-10-13

Nanoporous anodic aluminum oxide layers were fabricated on aluminum substrates with systematically varied pore diameters (20-80 nm) and oxide thicknesses (150-500 nm) by controlling the anodizing voltage and time and subsequent pore-widening process conditions. The porous nanostructures were then coated with a thin (only a couple of nanometers thick) Teflon film to make the surface hydrophobic and trap air in the pores. The corrosion resistance of the aluminum substrate was evaluated by a potentiodynamic polarization measurement in 3.5 wt % NaCl solution (saltwater). Results showed that the hydrophobic nanoporous anodic aluminum oxide layer significantly enhanced the corrosion resistance of the aluminum substrate compared to a hydrophilic oxide layer of the same nanostructures, to bare (nonanodized) aluminum with only a natural oxide layer on top, and to the latter coated with a thin Teflon film. The hydrophobic nanoporous anodic aluminum oxide layer with the largest pore diameter and the thickest oxide layer (i.e., the maximized air fraction) resulted in the best corrosion resistance with a corrosion inhibition efficiency of up to 99% for up to 7 days. The results demonstrate that the air impregnating the hydrophobic nanopores can effectively inhibit the penetration of corrosive media into the pores, leading to a significant improvement in corrosion resistance.

Assessment of Physical Activity and Active Transport Among School ...

International Development Research Centre (IDRC) Digital Library (Canada)

Assessment of Physical Activity and Active Transport Among School Children in Kenya, Nigeria, and Mozambique ... International Water Resources Association, in close collaboration with IDRC, is holding a webinar titled “Climate change and adaptive water management: Innovative solutions from the Global South”.

Decarbonization process for carbothermically produced aluminum

Science.gov (United States)

Bruno, Marshall J.; Carkin, Gerald E.; DeYoung, David H.; Dunlap, Sr., Ronald M.

2015-06-30

A method of recovering aluminum is provided. An alloy melt having Al.sub.4C.sub.3 and aluminum is provided. This mixture is cooled and then a sufficient amount of a finely dispersed gas is added to the alloy melt at a temperature of about 700.degree. C. to about 900.degree. C. The aluminum recovered is a decarbonized carbothermically produced aluminum where the step of adding a sufficient amount of the finely dispersed gas effects separation of the aluminum from the Al.sub.4C.sub.3 precipitates by flotation, resulting in two phases with the Al.sub.4C.sub.3 precipitates being the upper layer and the decarbonized aluminum being the lower layer. The aluminum is then recovered from the Al.sub.4C.sub.3 precipitates through decanting.

Comparative transcriptome analysis reveals key genes potentially related to soluble sugar and organic acid accumulation in watermelon

Science.gov (United States)

Gao, Lei; Zhao, Shengjie; Lu, Xuqiang; He, Nan; Zhu, Hongju; Dou, Junling

2018-01-01

Soluble sugars and organic acids are important components of fruit flavor and have a strong impact on the overall organoleptic quality of watermelon (Citrullus lanatus) fruit. Several studies have analyzed the expression levels of the genes related to soluble sugar accumulation and the dynamic changes in their content during watermelon fruit development and ripening. Nevertheless, to date, there have been no reports on the organic acid content in watermelon or the genes regulating their synthesis. In this study, the soluble sugars and organic acids in watermelon were measured and a comparative transcriptome analysis was performed to identify the key genes involved in the accumulation of these substances during fruit development and ripening. The watermelon cultivar ‘203Z’ and its near-isogenic line (NIL) ‘SW’ (in the ‘203Z’ background) were used as experimental materials. The results suggested that soluble sugar consist of fructose, glucose and sucrose while malic-, citric-, and oxalic acids are the primary organic acids in watermelon fruit. Several differentially expressed genes (DEGs) related to soluble sugar- and organic acid accumulation and metabolism were identified. These include the DEGs encoding raffinose synthase, sucrose synthase (SuSy), sucrose-phosphate synthase (SPSs), insoluble acid invertases (IAI), NAD-dependent malate dehydrogenase (NAD-cyt MDH), aluminum-activated malate transporter (ALMT), and citrate synthase (CS). This is the first report addressing comparative transcriptome analysis via NILs materials in watermelon fruit. These findings provide an important basis for understanding the molecular mechanism that leads to soluble sugar and organic acid accumulation and metabolism during watermelon fruit development and ripening. PMID:29324867

Comparative transcriptome analysis reveals key genes potentially related to soluble sugar and organic acid accumulation in watermelon.

Directory of Open Access Journals (Sweden)

Lei Gao

Full Text Available Soluble sugars and organic acids are important components of fruit flavor and have a strong impact on the overall organoleptic quality of watermelon (Citrullus lanatus fruit. Several studies have analyzed the expression levels of the genes related to soluble sugar accumulation and the dynamic changes in their content during watermelon fruit development and ripening. Nevertheless, to date, there have been no reports on the organic acid content in watermelon or the genes regulating their synthesis. In this study, the soluble sugars and organic acids in watermelon were measured and a comparative transcriptome analysis was performed to identify the key genes involved in the accumulation of these substances during fruit development and ripening. The watermelon cultivar '203Z' and its near-isogenic line (NIL 'SW' (in the '203Z' background were used as experimental materials. The results suggested that soluble sugar consist of fructose, glucose and sucrose while malic-, citric-, and oxalic acids are the primary organic acids in watermelon fruit. Several differentially expressed genes (DEGs related to soluble sugar- and organic acid accumulation and metabolism were identified. These include the DEGs encoding raffinose synthase, sucrose synthase (SuSy, sucrose-phosphate synthase (SPSs, insoluble acid invertases (IAI, NAD-dependent malate dehydrogenase (NAD-cyt MDH, aluminum-activated malate transporter (ALMT, and citrate synthase (CS. This is the first report addressing comparative transcriptome analysis via NILs materials in watermelon fruit. These findings provide an important basis for understanding the molecular mechanism that leads to soluble sugar and organic acid accumulation and metabolism during watermelon fruit development and ripening.

Comparative transcriptome analysis reveals key genes potentially related to soluble sugar and organic acid accumulation in watermelon.

Science.gov (United States)

Gao, Lei; Zhao, Shengjie; Lu, Xuqiang; He, Nan; Zhu, Hongju; Dou, Junling; Liu, Wenge

2018-01-01

Soluble sugars and organic acids are important components of fruit flavor and have a strong impact on the overall organoleptic quality of watermelon (Citrullus lanatus) fruit. Several studies have analyzed the expression levels of the genes related to soluble sugar accumulation and the dynamic changes in their content during watermelon fruit development and ripening. Nevertheless, to date, there have been no reports on the organic acid content in watermelon or the genes regulating their synthesis. In this study, the soluble sugars and organic acids in watermelon were measured and a comparative transcriptome analysis was performed to identify the key genes involved in the accumulation of these substances during fruit development and ripening. The watermelon cultivar '203Z' and its near-isogenic line (NIL) 'SW' (in the '203Z' background) were used as experimental materials. The results suggested that soluble sugar consist of fructose, glucose and sucrose while malic-, citric-, and oxalic acids are the primary organic acids in watermelon fruit. Several differentially expressed genes (DEGs) related to soluble sugar- and organic acid accumulation and metabolism were identified. These include the DEGs encoding raffinose synthase, sucrose synthase (SuSy), sucrose-phosphate synthase (SPSs), insoluble acid invertases (IAI), NAD-dependent malate dehydrogenase (NAD-cyt MDH), aluminum-activated malate transporter (ALMT), and citrate synthase (CS). This is the first report addressing comparative transcriptome analysis via NILs materials in watermelon fruit. These findings provide an important basis for understanding the molecular mechanism that leads to soluble sugar and organic acid accumulation and metabolism during watermelon fruit development and ripening.

Critical role of mitochondrial ROS is dependent on their site of production on the electron transport chain in ischemic heart.

Science.gov (United States)

Madungwe, Ngonidzashe B; Zilberstein, Netanel F; Feng, Yansheng; Bopassa, Jean C

2016-01-01

Reactive oxygen species (ROS) generation has been implicated in many pathologies including ischemia/reperfusion (I/R) injury. This led to multiple studies on antioxidant therapies to treat cardiovascular diseases but paradoxically, results have so far been mixed as ROS production can be beneficial as a signaling mechanism and in cardiac protection via preconditioning interventions. We investigated whether the differential impact of increased ROS in injury as well as in protection could be explained by their site of production on the mitochondrial electron transport chain. Using amplex red to measure ROS production, we found that mitochondria isolated from hearts after I/R produced more ROS than non-ischemic when complex I substrate (glutamate/malate) was used. Interestingly, the substrates of complex II (succinate) and ubiquinone (sn-glycerol 3-phosphate, G3P) produced less ROS in mitochondria from I/R hearts compared to normal healthy hearts. The inhibitors of complex I (rotenone) and complex III (antimycin A) increased ROS production when glutamate/malate and G3P were used; in contrast, they reduced ROS production when the complex II substrate was used. Mitochondrial calcium retention capacity required to induce mitochondrial permeability transition pore (mPTP) opening was measured using calcium green fluorescence and was found to be higher when mitochondria were treated with G3P and succinate compared to glutamate/malate. Furthermore, Langendorff hearts treated with glutamate/malate exhibited reduced cardiac functional recovery and increased myocardial infarct size compared to hearts treated with G3P. Thus, ROS production by the stimulated respiratory chain complexes I and III has opposite roles: cardio-deleterious when produced in complex I and cardio-protective when produced in complex III. The mechanism of these ROS involves the inhibition of the mPTP opening, a key event in cell death following ischemia/reperfusion injury.

Optimization of data analysis for the in vivo neutron activation analysis of aluminum in bone

International Nuclear Information System (INIS)

Mohseni, H.K.; Matysiak, W.; Chettle, D.R.; Byun, S.H.; Priest, N.; Atanackovic, J.; Prestwich, W.V.

2016-01-01

An existing system at McMaster University has been used for the in vivo measurement of aluminum in human bone. Precise and detailed analysis approaches are necessary to determine the aluminum concentration because of the low levels of aluminum found in the bone and the challenges associated with its detection. Phantoms resembling the composition of the human hand with varying concentrations of aluminum were made for testing the system prior to the application to human studies. A spectral decomposition model and a photopeak fitting model involving the inverse-variance weighted mean and a time-dependent analysis were explored to analyze the results and determine the model with the best performance and lowest minimum detection limit. The results showed that the spectral decomposition and the photopeak fitting model with the inverse-variance weighted mean both provided better results compared to the other methods tested. The spectral decomposition method resulted in a marginally lower detection limit (5 μg Al/g Ca) compared to the inverse-variance weighted mean (5.2 μg Al/g Ca), rendering both equally applicable to human measurements. - Highlights: • Data analysis optimization for measuring aluminum in human subjects. • Development and Comparison of multiple approaches to data analysis for NAA of Al. • Improving the MDL of IVNAA method for Al measurement compared to previous studies. • Exploring the advantage of sequential data acquisition for IVNAA data analysis.

Weld Repair of Thin Aluminum Sheet

Science.gov (United States)

Beuyukian, C. S.; Mitchell, M. J.

1986-01-01

Weld repairing of thin aluminum sheets now possible, using niobium shield and copper heat sinks. Refractory niobium shield protects aluminum adjacent to hole, while copper heat sinks help conduct heat away from repair site. Technique limits tungsten/inert-gas (TIG) welding bombardment zone to melt area, leaving surrounding areas around weld unaffected. Used successfully to repair aluminum cold plates on Space Shuttle, Commercial applications, especially in sealing fractures, dents, and holes in thin aluminum face sheets or clad brazing sheet in cold plates, heat exchangers, coolers, and Solar panels. While particularly suited to thin aluminum sheet, this process also used in thicker aluminum material to prevent surface damage near weld area.

Gas evolution behavior of aluminum in mortar

Energy Technology Data Exchange (ETDEWEB)

Hashizume, Shuji; Matsumoto, Junko; Banba, Tsunetaka [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1996-10-01

As a part of study of leaching behavior for solidified dry low level radioactive waste, gas evolution behavior of aluminum in mortar was investigated, and a plan of our research was proposed. The effect of pH on corrosion rate of aluminum, corrosion product, time dependency of corrosion rate of aluminum in mortar, change of corrosion mechanism, the effects of Na, Ca and Cl ions on corrosion rate of aluminum in mortar and corrosion behavior of aluminum when aluminum was used as sacrificed anode in reinforced concrete were previously clarified. Study of the effects of environmental factors such as pH, kind of ions and temperature on gas evolution behavior of aluminum and the effect of aluminum/carbon steel surface ratio no gas evolution behavior of aluminum were planed. (author). 75 refs.

Gas evolution behavior of aluminum in mortar

International Nuclear Information System (INIS)

Hashizume, Shuji; Matsumoto, Junko; Banba, Tsunetaka

1996-10-01

As a part of study of leaching behavior for solidified dry low level radioactive waste, gas evolution behavior of aluminum in mortar was investigated, and a plan of our research was proposed. The effect of pH on corrosion rate of aluminum, corrosion product, time dependency of corrosion rate of aluminum in mortar, change of corrosion mechanism, the effects of Na, Ca and Cl ions on corrosion rate of aluminum in mortar and corrosion behavior of aluminum when aluminum was used as sacrificed anode in reinforced concrete were previously clarified. Study of the effects of environmental factors such as pH, kind of ions and temperature on gas evolution behavior of aluminum and the effect of aluminum/carbon steel surface ratio no gas evolution behavior of aluminum were planed. (author). 75 refs

Chemically activated nanodiamonds for aluminum alloy corrosion protection and monitoring

Science.gov (United States)

Hannstein, Inga; Adler, Anne-Katrin; Lapina, Victoria; Osipov, Vladimir; Opitz, Jörg; Schreiber, Jürgen; Meyendorf, Norbert

2009-03-01

In the present study, a smart coating for light metal alloys was developed and investigated. Chemically activated nanodiamonds (CANDiT) were electrophoretically deposited onto anodized aluminum alloy AA2024 substrates in order to increase corrosion resistance, enhance bonding properties and establish a means of corrosion monitoring based on the fluorescence behavior of the particles. In order to create stable aqueous CANDiT dispersions suitable for electrophoretic deposition, mechanical milling had to be implemented under specific chemical conditions. The influence of the CANDiT volume fraction and pH of the dispersion on the electrochemical properties of the coated samples was investigated. Linear voltammetry measurements reveal that the chemical characteristics of the CANDiT dispersion have a distinct influence on the quality of the coating. The fluorescence spectra as well as fluorescence excitation spectra of the samples show that corrosion can be easily detected by optical means. Furthermore, an optimization on the basis of "smart" - algorithms for the data processing of a surface analysis by the laser-speckle-method is presented.

Advocacy for active transport: advocate and city council perspectives

Directory of Open Access Journals (Sweden)

Rosenby Marieah

2010-01-01

Full Text Available Abstract Background Effective advocacy is an important part of efforts to increase population participation in physical activity. Research about effective health advocacy is scarce, however, the health sector can learn from the experiences and knowledge of community advocates and those who are on the receiving end of this advocacy. The aim of this study is to explore advocacy for active transport from the perspectives of community advocates and representatives from City councils. Methods Cycling and walking advocates were identified from the local contact list of Cycling Advocates Network and Living Streets Aotearoa. Semi-structured telephone interviews were conducted with cycle and walking advocates from throughout New Zealand. Advocates also nominated a suitable council officer at their local City council to be interviewed. Interviews were recorded and transcribed and categories of responses for each of the questions created. Results Several processes were used by advocates to engage with council staff, including formal council submissions, meetings, stakeholder forums and partnership in running community events promoting active transport. Several other agencies were identified as being influential for active transport, some as potential coalition partners and others as potential adversaries. Barriers to improving conditions for active transport included a lack of funding, a lack of will-power among either council staff or councillors, limited council staff capacity (time or training and a culture of providing infrastructure for motor vehicles instead of people. Several suggestions were made about how the health sector could contribute to advocacy efforts, including encouraging political commitment, engaging the media, communicating the potential health benefits of active transport to the general public and being role models in terms of personal travel mode choice and having workplaces that support participation in active transport

Phonon optimized interatomic potential for aluminum

Directory of Open Access Journals (Sweden)

Murali Gopal Muraleedharan

2017-12-01

Full Text Available We address the problem of generating a phonon optimized interatomic potential (POP for aluminum. The POP methodology, which has already been shown to work for semiconductors such as silicon and germanium, uses an evolutionary strategy based on a genetic algorithm (GA to optimize the free parameters in an empirical interatomic potential (EIP. For aluminum, we used the Vashishta functional form. The training data set was generated ab initio, consisting of forces, energy vs. volume, stresses, and harmonic and cubic force constants obtained from density functional theory (DFT calculations. Existing potentials for aluminum, such as the embedded atom method (EAM and charge-optimized many-body (COMB3 potential, show larger errors when the EIP forces are compared with those predicted by DFT, and thus they are not particularly well suited for reproducing phonon properties. Using a comprehensive Vashishta functional form, which involves short and long-ranged interactions, as well as three-body terms, we were able to better capture interactions that reproduce phonon properties accurately. Furthermore, the Vashishta potential is flexible enough to be extended to Al2O3 and the interface between Al-Al2O3, which is technologically important for combustion of solid Al nano powders. The POP developed here is tested for accuracy by comparing phonon thermal conductivity accumulation plots, density of states, and dispersion relations with DFT results. It is shown to perform well in molecular dynamics (MD simulations as well, where the phonon thermal conductivity is calculated via the Green-Kubo relation. The results are within 10% of the values obtained by solving the Boltzmann transport equation (BTE, employing Fermi’s Golden Rule to predict the phonon-phonon relaxation times.

Phonon optimized interatomic potential for aluminum

Science.gov (United States)

Muraleedharan, Murali Gopal; Rohskopf, Andrew; Yang, Vigor; Henry, Asegun

2017-12-01

We address the problem of generating a phonon optimized interatomic potential (POP) for aluminum. The POP methodology, which has already been shown to work for semiconductors such as silicon and germanium, uses an evolutionary strategy based on a genetic algorithm (GA) to optimize the free parameters in an empirical interatomic potential (EIP). For aluminum, we used the Vashishta functional form. The training data set was generated ab initio, consisting of forces, energy vs. volume, stresses, and harmonic and cubic force constants obtained from density functional theory (DFT) calculations. Existing potentials for aluminum, such as the embedded atom method (EAM) and charge-optimized many-body (COMB3) potential, show larger errors when the EIP forces are compared with those predicted by DFT, and thus they are not particularly well suited for reproducing phonon properties. Using a comprehensive Vashishta functional form, which involves short and long-ranged interactions, as well as three-body terms, we were able to better capture interactions that reproduce phonon properties accurately. Furthermore, the Vashishta potential is flexible enough to be extended to Al2O3 and the interface between Al-Al2O3, which is technologically important for combustion of solid Al nano powders. The POP developed here is tested for accuracy by comparing phonon thermal conductivity accumulation plots, density of states, and dispersion relations with DFT results. It is shown to perform well in molecular dynamics (MD) simulations as well, where the phonon thermal conductivity is calculated via the Green-Kubo relation. The results are within 10% of the values obtained by solving the Boltzmann transport equation (BTE), employing Fermi's Golden Rule to predict the phonon-phonon relaxation times.

The Influence of Urban Land-Use and Public Transport Facilities on Active Commuting in Wellington, New Zealand: Active Transport Forecasting Using the WILUTE Model

Directory of Open Access Journals (Sweden)

Joreintje Dingena Mackenbach

2016-03-01

Full Text Available Physical activity has numerous physical and mental health benefits, and active commuting (walking or cycling to work can help meet physical activity recommendations. This study investigated socioeconomic differences in active commuting, and assessed the impact of urban land-use and public transport policies on active commuting in the Wellington region in New Zealand. We combined data from the New Zealand Household Travel Survey and GIS data on land-use and public transport facilities with the Wellington Integrated Land-Use, Transportation and Environment (WILUTE model, and forecasted changes in active commuter trips associated with changes in the built environment. Results indicated high income individuals were more likely to commute actively than individuals on low income. Several land-use and transportation factors were associated with active commuting and results from the modelling showed a potential increase in active commuting following an increase in bus frequency and parking fees. In conclusion, regional level policies stimulating environmental factors that directly or indirectly affect active commuting may be a promising strategy to increase population level physical activity. Access to, and frequency of, public transport in the neighbourhood can act as a facilitator for a more active lifestyle among its residents without negatively affecting disadvantaged groups.

Aluminum-based metal-air batteries

Science.gov (United States)

Friesen, Cody A.; Martinez, Jose Antonio Bautista

2016-01-12

Provided in one embodiment is an electrochemical cell, comprising: (i) a plurality of electrodes, comprising a fuel electrode that comprises aluminum and an air electrode that absorbs gaseous oxygen, the electrodes being operable in a discharge mode wherein the aluminum is oxidized at the fuel electrode and oxygen is reduced at the air electrode, and (ii) an ionically conductive medium, comprising an organic solvent; wherein during non-use of the cell, the organic solvent promotes formation of a protective interface between the aluminum of the fuel electrode and the ionically conductive medium, and wherein at an onset of the discharge mode, at least some of the protective interface is removed from the aluminum to thereafter permit oxidation of the aluminum during the discharge mode.

A Rare but Potentially Fatal Poisoning; Aluminum Phosphide Poisoning

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Orkun Tolunay

2017-04-01

Full Text Available Phosphide, a very toxic gas, is used in our country as aluminium phosphide tablets impregnated in clay. It is widely used since it has a very high diffusion capacity, whereby it can eradicate all living creatures in any form of their life cycle and does not leave any remnants in agricultural products. Aluminum phosphide poisoning is among intoxications for which there are still no true antidotes. Mortality rate varies between 30% and 100%. This paper presents a case of aluminum phosphide poisoning caused by the uncompleted suicide attempt. A 14-year-old girl, who swallowed aluminum phosphate tablets, was brought to the emergency department with the complaints of nausea and vomiting. The patient was treated with gastric lavage and activated charcoal. Since the patient ingested a lethal amount of aluminum phosphide, she was referred to the pediatric intensive care unit. The patient was discharged in stable condition after supportive care and monitoring. Specific antidotes are life-saving in poisonings. However, this case was presented to show how general treatment principles and quick access to health services affect the result of treatment. Also, we aimed to highlight the uncontrolled selling of aluminum phosphate, which results in high mortality rates in case of poisoning.

Optimization of data analysis for the in vivo neutron activation analysis of aluminum in bone.

Science.gov (United States)

Mohseni, H K; Matysiak, W; Chettle, D R; Byun, S H; Priest, N; Atanackovic, J; Prestwich, W V

2016-10-01

An existing system at McMaster University has been used for the in vivo measurement of aluminum in human bone. Precise and detailed analysis approaches are necessary to determine the aluminum concentration because of the low levels of aluminum found in the bone and the challenges associated with its detection. Phantoms resembling the composition of the human hand with varying concentrations of aluminum were made for testing the system prior to the application to human studies. A spectral decomposition model and a photopeak fitting model involving the inverse-variance weighted mean and a time-dependent analysis were explored to analyze the results and determine the model with the best performance and lowest minimum detection limit. The results showed that the spectral decomposition and the photopeak fitting model with the inverse-variance weighted mean both provided better results compared to the other methods tested. The spectral decomposition method resulted in a marginally lower detection limit (5μg Al/g Ca) compared to the inverse-variance weighted mean (5.2μg Al/g Ca), rendering both equally applicable to human measurements. Copyright © 2016 Elsevier Ltd. All rights reserved.

High Performance Liquid Chromatographic Analysis of Almotriptan Malate in Bulk and Tablets

Directory of Open Access Journals (Sweden)

Chandra Bala Sekaran

2013-02-01

Full Text Available Purpose: A simple RP-HPLC method has been developed and validated for the determination of almotriptan malate (ATM in bulk and tablets. Methods: Chromatographic separation of ATM was achieved by using a Thermo Scientific C18 column. A Mobile phase containing a mixture of methanol, water and acetic acid (4:8:0.1 v/v was pumped at the flow rate of 1 mL/min. Detection was performed at 227 nm. According to ICH guidelines, the method was validated. Results: The calibration curve was linear in the concentration range 5–60 μg/mL for the ATM with regression coefficient 0.9999. The method was precise with RSD <1.2%. Excellent recoveries of 99.60 - 100.80% proved the accuracy of the method. The limits of detection and quantification were found to be 0.025 and 0.075 μg/mL, respectively. Conclusion: The method was successfully applied for the quantification of ATM in tablets with acceptable accuracy and precision.

Individual, Social, and Environmental Correlates of Active Transportation Patterns in French Women.

Science.gov (United States)

Perchoux, Camille; Enaux, Christophe; Oppert, Jean-Michel; Menai, Mehdi; Charreire, Hélène; Salze, Paul; Weber, Christiane; Hercberg, Serge; Feuillet, Thierry; Hess, Franck; Roda, Célina; Simon, Chantal; Nazare, Julie-Anne

2017-01-01

The objectives were (1) to define physical activity (PA) and sedentary behaviors (SB) patterns in daily life contexts (work, leisure, and transportation) in French working women from NutriNet-Santé web-cohort and (2) to identify pattern(s) of active transportation and their individual, social, and environmental correlates. 23,432 participants completed two questionnaires to evaluate PA and SB in daily life contexts and individual representations of residential neighborhood and transportation modes. Hierarchical cluster analysis was performed which identified 6 distinct movement behavior patterns: (i) active occupation, high sedentary leisure, (ii) sedentary occupation, low leisure, (iii) sedentary transportation, (iv) sedentary occupation and leisure, (v) active transportation, and (vi) active leisure. Multinomial logistic regressions were performed to identify correlates of the "active transportation" cluster. The perceived environmental characteristics positively associated with "active transportation" included "high availability of destinations around home," "presence of bicycle paths," and "low traffic." A "positive image of walking/cycling," the "individual feeling of being physically active," and a "high use of active transport modes by relatives/friends" were positively related to "active transportation," identified as a unique pattern regarding individual and environmental correlates. Identification of PA and SB context-specific patterns will help to understand movement behaviors' complexity and to design interventions to promote active transportation in specific subgroups.

Effect of Silicon on Desulfurization of Aluminum-killed Steels

Science.gov (United States)

Roy, Debdutta

controlled by mass transfer in the metal and slag phase mass transfer has a minor effect on the overall desulfurization kinetics. The model results are in agreement with the experimental data for the change in sulfur, silicon and aluminum contents with time which renders credibility to the underlying hypothesis of the kinetic model. Although the change of sulfur content with time is not very sensitive to the activity data source, the change of aluminum and silicon contents with time depend on the activity data source. The experimental results demonstrate that if the silicon content in the steel is high enough, the silicon can reduce the alumina from the slag and thus the steel melt will pick up aluminum. This can cause significant savings in aluminum consumption. For most of the slag compositions used in the experiments, the overall mass transfer is only limited by the steel phase and the slag phase mass transfer can be neglected for most practical cases. Mass balance calculations in the experiments support the basis of the model and also show that with respect to aluminum consumption, silica reduction is the main aluminum consuming (or production) reaction and the desulfurization reaction is only a secondary consumer of aluminum. Results from the plant trials conducted to test the effect of silicon on ladle desulfurization show that the rate and extent of desulfurization increase with the increase of the initial Si content, so in the ladle refining process, adding all the silicon in the beginning with the aluminum and the fluxes will be beneficial and could save considerable processing time at the ladle. The aluminum consumption for the heats with silicon added in the beginning (both in terms of the Al added to the steel and as slag deoxidants) is considerably lower compared to the cases where the silicon is added at the end. However, on a relative cost term, aluminum and silicon are similarly priced so substitution would not offer a major cost advantage.

A Virtual Aluminum Reduction Cell

Science.gov (United States)

Zhang, Hongliang; Zhou, Chenn Q.; Wu, Bing; Li, Jie

2013-11-01

The most important component in the aluminum industry is the aluminum reduction cell; it has received considerable interests and resources to conduct research to improve its productivity and energy efficiency. The current study focused on the integration of numerical simulation data and virtual reality technology to create a scientifically and practically realistic virtual aluminum reduction cell by presenting complex cell structures and physical-chemical phenomena. The multiphysical field simulation models were first built and solved in ANSYS software (ANSYS Inc., Canonsburg, PA, USA). Then, the methodology of combining the simulation results with virtual reality was introduced, and a virtual aluminum reduction cell was created. The demonstration showed that a computer-based world could be created in which people who are not analysis experts can see the detailed cell structure in a context that they can understand easily. With the application of the virtual aluminum reduction cell, even people who are familiar with aluminum reduction cell operations can gain insights that make it possible to understand the root causes of observed problems and plan design changes in much less time.

Crystallization and crystallographic analysis of the ligand-binding domain of the Pseudomonas putida chemoreceptor McpS in complex with malate and succinate

International Nuclear Information System (INIS)

Gavira, J. A.; Lacal, J.; Ramos, J. L.; García-Ruiz, J. M.; Krell, T.; Pineda-Molina, E.

2012-01-01

The crystallization of the ligand-binding domain of the methyl-accepting chemotaxis protein chemoreceptor McpS (McpS-LBD) is reported. Methyl-accepting chemotaxis proteins (MCPs) are transmembrane proteins that sense changes in environmental signals, generating a chemotactic response and regulating other cellular processes. MCPs are composed of two main domains: a ligand-binding domain (LBD) and a cytosolic signalling domain (CSD). Here, the crystallization of the LBD of the chemoreceptor McpS (McpS-LBD) is reported. McpS-LBD is responsible for sensing most of the TCA-cycle intermediates in the soil bacterium Pseudomonas putida KT2440. McpS-LBD was expressed, purified and crystallized in complex with two of its natural ligands (malate and succinate). Crystals were obtained by both the counter-diffusion and the hanging-drop vapour-diffusion techniques after pre-incubation of McpS-LBD with the ligands. The crystals were isomorphous and belonged to space group C2, with two molecules per asymmetric unit. Diffraction data were collected at the ESRF synchrotron X-ray source to resolutions of 1.8 and 1.9 Å for the malate and succinate complexes, respectively

Activity-Dependent Regulation of Surface Glucose Transporter-3

OpenAIRE

Ferreira, Jainne M.; Burnett, Arthur L.; Rameau, Gerald A.

2011-01-01

Glucose transporter 3 (GLUT3) is the main facilitative glucose transporter in neurons. Glucose provides neurons with a critical energy source for neuronal activity. However, the mechanism by which neuronal activity controls glucose influx via GLUT3 is unknown. We investigated the influence of synaptic stimulation on GLUT3 surface expression and glucose import in primary cultured cortical and hippocampal neurons. Synaptic activity increased surface expression of GLUT3 leading to an elevation o...

Electrically conductive anodized aluminum coatings

Science.gov (United States)

Alwitt, Robert S. (Inventor); Liu, Yanming (Inventor)

2001-01-01

A process for producing anodized aluminum with enhanced electrical conductivity, comprising anodic oxidation of aluminum alloy substrate, electrolytic deposition of a small amount of metal into the pores of the anodized aluminum, and electrolytic anodic deposition of an electrically conductive oxide, including manganese dioxide, into the pores containing the metal deposit; and the product produced by the process.

ALUMINUM AND CHROMIUM LEACHING WORKSHOP WHITEPAPER

International Nuclear Information System (INIS)

McCabe, D; Jeff Pike, J; Bill Wilmarth, B

2007-01-01

formulations. Disposal of the resulting aluminum and chromium-rich streams are different at the two sites, with vitrification into Low Activity Waste (LAW) glass at Hanford, and solidification in Saltstone at SRS. Prior to disposal, the leachate solutions must be treated to remove radionuclides, resulting in increased operating costs and extended facility processing schedules. Interim storage of leachate can also add costs and delay tank closure. Recent projections at Hanford indicate that up to 40,000 metric tons of sodium would be needed to dissolve the aluminum and maintain it in solution, which nearly doubles the amount of sodium in the entire current waste tank inventory. This underscores the dramatic impact that the aluminum leaching can have on the entire system. A comprehensive view of leaching and the downstream impacts must therefore be considered prior to implementation. Many laboratory scale tests for aluminum and chromium dissolution have been run on Hanford wastes, with samples from 46 tanks tested. Three samples from SRS tanks have been tested, out of seven tanks containing high aluminum sludge. One full-scale aluminum dissolution was successfully performed on waste at SRS in 1982, but generated a very large quantity of liquid waste (∼3,000,000 gallons). No large-scale tests have been done on Hanford wastes. Although the data to date give a generally positive indication that aluminum dissolution will work, many issues remain, predominantly because of variable waste compositions and changes in process conditions, downstream processing, or storage limitations. Better approaches are needed to deal with the waste volumes and limitations on disposal methods. To develop a better approach requires a more extensive understanding of the kinetics of dissolution, as well as the factors that effect rates, effectiveness, and secondary species. Models of the dissolution rate that have been developed are useful, but suffer from limitations on applicable compositional ranges

Mesoporous aluminum phosphite

International Nuclear Information System (INIS)

El Haskouri, Jamal; Perez-Cabero, Monica; Guillem, Carmen; Latorre, Julio; Beltran, Aurelio; Beltran, Daniel; Amoros, Pedro

2009-01-01

High surface area pure mesoporous aluminum-phosphorus oxide-based derivatives have been synthesized through an S + I - surfactant-assisted cooperative mechanism by means of a one-pot preparative procedure from aqueous solution and starting from aluminum atrane complexes and phosphoric and/or phosphorous acids. A soft chemical extraction procedure allows opening the pore system of the parent as-prepared materials by exchanging the surfactant without mesostructure collapse. The nature of the pore wall can be modulated from mesoporous aluminum phosphate (ALPO) up to total incorporation of phosphite entities (mesoporous aluminum phosphite), which results in a gradual evolution of the acidic properties of the final materials. While phosphate groups in ALPO act as network building blocks (bridging Al atoms), the phosphite entities become basically attached to the pore surface, what gives practically empty channels. The mesoporous nature of the final materials is confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and N 2 adsorption-desorption isotherms. The materials present regular unimodal pore systems whose order decreases as the phosphite content increases. NMR spectroscopic results confirm the incorporation of oxo-phosphorus entities to the framework of these materials and also provide us useful information concerning the mechanism through which they are formed. - Abstract: TEM image of the mesoporous aluminum phosphite showing the hexagonal disordered pore array that is generated by using surfactant micelles as template. Also a scheme emphasizing the presence of an alumina-rich core and an ALPO-like pore surface is presented.

76 FR 7560 - Agency Information Collection Activities; Proposed Collection; Comment Request; Transportation...

Science.gov (United States)

2011-02-10

... Activities; Proposed Collection; Comment Request; Transportation Conformity Determinations for Federally... federally supported transportation activities are consistent with (``conform to'') the purpose of the state air quality implementation plan (SIP). Transportation activities include transportation plans...

Analyses of the transportation of spent research reactor fuel in the United States

International Nuclear Information System (INIS)

Cashwell, J.W.; Neuhauser, K.S.

1989-01-01

We analyzed the impacts of transportation of research reactor spent fuel from US and foreign reactors for the US Department of Energy's (DOE) Office of Defense Programs. Two separate shipment programs were analyzed. The shipment of research reactor spent fuel from Taiwan to the US (Fuel Movement Program), and the return of research reactor spent fuels of US origin from foreign and domestic reactors (Research Reactor Fuel Return Program). To perform these analyses, a comprehensive methodology for analyzing the probabilities and consequences of transportation in coastal waters and port facilities, handling at the port, and shipment by truck to reprocessing facilities was developed. The Taiwanese fuel consists of low-burnup aluminum-clad metallic uranium research reactor spent fuel; the other fuels are primarily aluminum-clad oxide fuels. The Fuel Movement Program is ongoing, while the Fuel Return Program addresses future shipments over a ten-year period. The operational aspects of the Taiwanese shipments have been uniform, but several possible shipping configurations are possible for the Fuel Return Program shipments. The risks of transporting spent nuclear fuel and other radioactive materials by all modes have been analyzed extensively. Comprehensive assessments, which bound the impacts of spent fuel transport, demonstrate that when shipments are made in compliance with applicable regulations, the risks for all such transport are low. For comparison with previously licensed transport activities and to provide continuity with earlier analyses, the results for shipment of 150-day-old commercial pressurized water reactor (PWR) spent fuel are presented as part of this study

Assessment of Physical Activity and Active Transport Among School ...

International Development Research Centre (IDRC) Digital Library (Canada)

This study will assess physical activity and active transportation levels among ... the Neighbourhood Environment Walkability Scale instrument (NEWS) for use in ... prix de la diplomatie scientifique de la part du gouvernement de l'Afrique du Sud. ... Dans le dernier numéro du bulletin de BRAS, lisez un message d'adieu de ...

Measurement of quasiparticle transport in aluminum films using tungsten transition-edge sensors

International Nuclear Information System (INIS)

Yen, J. J.; Shank, B.; Cabrera, B.; Moffatt, R.; Redl, P.; Young, B. A.; Tortorici, E. C.; Brink, P. L.; Cherry, M.; Tomada, A.; Kreikebaum, J. M.

2014-01-01

We report on experimental studies of phonon sensors which utilize quasiparticle diffusion in thin aluminum films connected to tungsten transition-edge-sensors (TESs) operated at 35 mK. We show that basic TES physics and a simple physical model of the overlap region between the W and Al films in our devices enables us to accurately reproduce the experimentally observed pulse shapes from x-rays absorbed in the Al films. We further estimate quasiparticle loss in Al films using a simple diffusion equation approach. These studies allow the design of phonon sensors with improved performance.

Transport of the moving barrier driven by chiral active particles

Science.gov (United States)

Liao, Jing-jing; Huang, Xiao-qun; Ai, Bao-quan

2018-03-01

Transport of a moving V-shaped barrier exposed to a bath of chiral active particles is investigated in a two-dimensional channel. Due to the chirality of active particles and the transversal asymmetry of the barrier position, active particles can power and steer the directed transport of the barrier in the longitudinal direction. The transport of the barrier is determined by the chirality of active particles. The moving barrier and active particles move in the opposite directions. The average velocity of the barrier is much larger than that of active particles. There exist optimal parameters (the chirality, the self-propulsion speed, the packing fraction, and the channel width) at which the average velocity of the barrier takes its maximal value. In particular, tailoring the geometry of the barrier and the active concentration provides novel strategies to control the transport properties of micro-objects or cargoes in an active medium.

Measurement of tritium activity in the aluminum pipe of JRR-2 heavy water primary cooling system using imaging plate

International Nuclear Information System (INIS)

Motoishi, Shoji; Kobayashi, Katsutoshi

2000-12-01

JRR-2 is the heavy water cooling type nuclear reactor, which has been operated for 36 years (1960-1976) and in the process of decommissioning at present. For this reason, evaluation of tritium quantity permeated into the pipe and apparatus of the primary coolant heavy water circulating system is important. In the Radioisotope Production Division, activity of tritium in aluminum pipe was measured with imaging plate (IP), liquid scintillation analyzer and high purity germanium detector (HPGe). After acrylic paints was applied for the region except for tritium contamination on the surface of aluminum pipe, only the oxidized contaminated part was dissolved by 1.5%(1.21M) HF for 3 minutes, and measured with IP. As a result, the tritium was found to permeate in the depth of 25 μm. Moreover, 90% of it was found to be distributed within 7 μm. (author)

What Moves Them? Active Transport among Inhabitants of Dutch Deprived Districts

Directory of Open Access Journals (Sweden)

Carla Saris

2013-01-01

Full Text Available Background. Active modes of transport like walking and cycling have been shown to be valuable contributions to daily physical activity. The current study investigates associations between personal and neighbourhood environmental characteristics and active transport among inhabitants of Dutch deprived districts. Method. Questionnaires about health, neighbourhoods, and physical activity behaviour were completed by 742 adults. Data was analysed by means of multivariate linear regression analyses. Results. Being younger, female, and migrant and having a normal weight were associated with more walking for active transport. Being younger, male, and native Dutch and having a normal weight were associated with more cycling for active transport. Neighbourhood characteristics were generally not correlated with active transport. Stratified analyses, based on significant person-environment interactions, showed that migrants and women walked more when cars did not exceed maximum speed in nearby streets and that younger people walked more when speed of traffic in nearby streets was perceived as low. Among migrants, more cycling was associated with the perceived attractiveness of the neighbourhood surroundings. Discussion and Conclusion. Results indicated that among inhabitants of Dutch deprived districts, personal characteristics were associated with active transport, whereas neighbourhood environmental characteristics were generally not associated with active transport. Nevertheless, interaction effects showed differences among subgroups that should be considered in intervention development.

Gut: An underestimated target organ for Aluminum.

Science.gov (United States)

Vignal, C; Desreumaux, P; Body-Malapel, M

2016-06-01

Since World War II, several factors such as an impressive industrial growth, an enhanced environmental bioavailability and intensified food consumption have contributed to a significant amplification of human exposure to aluminum. Aluminum is particularly present in food, beverages, some drugs and airbone dust. In our food, aluminum is superimposed via additives and cooking utensils. Therefore, the tolerable intake of aluminum is exceeded for a significant part of the world population, especially in children who are more vulnerable to toxic effects of pollutants than adults. Faced with this oral aluminum influx, intestinal tract is an essential barrier, especially as 38% of ingested aluminum accumulates at the intestinal mucosa. Although still poorly documented to date, the impact of oral exposure to aluminum in conditions relevant to real human exposure appears to be deleterious for gut homeostasis. Aluminum ingestion affects the regulation of the permeability, the microflora and the immune function of intestine. Nowadays, several arguments are consistent with an involvement of aluminum as an environmental risk factor for inflammatory bowel diseases. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Infrared radiation properties of anodized aluminum

Energy Technology Data Exchange (ETDEWEB)

Kohara, S. [Science Univ. of Tokyo, Noda, Chiba (Japan). Dept. of Materials Science and Technology; Niimi, Y. [Science Univ. of Tokyo, Noda, Chiba (Japan). Dept. of Materials Science and Technology

1996-12-31

The infrared radiation heating is an efficient and energy saving heating method. Ceramics have been used as an infrared radiant material, because the emissivity of metals is lower than that of ceramics. However, anodized aluminum could be used as the infrared radiant material since an aluminum oxide film is formed on the surface. In the present study, the infrared radiation properties of anodized aluminum have been investigated by determining the spectral emissivity curve. The spectral emissivity curve of anodized aluminum changed with the anodizing time. The spectral emissivity curve shifted to the higher level after anodizing for 10 min, but little changed afterwards. The infrared radiant material with high level spectral emissivity curve can be achieved by making an oxide film thicker than about 15 {mu}m on the surface of aluminum. Thus, anodized aluminum is applicable for the infrared radiation heating. (orig.)

Vapor corrosion of aluminum cladding alloys and aluminum-uranium fuel materials in storage environments

International Nuclear Information System (INIS)

Lam, P.; Sindelar, R.L.; Peacock, H.B. Jr.

1997-04-01

An experimental investigation of the effects of vapor environments on the corrosion of aluminum spent nuclear fuel (A1 SNF) has been performed. Aluminum cladding alloys and aluminum-uranium fuel alloys have been exposed to environments of air/water vapor/ionizing radiation and characterized for applications to degradation mode analysis for interim dry and repository storage systems. Models have been developed to allow predictions of the corrosion response under conditions of unlimited corrodant species. Threshold levels of water vapor under which corrosion does not occur have been identified through tests under conditions of limited corrodant species. Coupons of aluminum 1100, 5052, and 6061, the US equivalent of cladding alloys used to manufacture foreign research reactor fuels, and several aluminum-uranium alloys (aluminum-10, 18, and 33 wt% uranium) were exposed to various controlled vapor environments in air within the following ranges of conditions: Temperature -- 80 to 200 C; Relative Humidity -- 0 to 100% using atmospheric condensate water and using added nitric acid to simulate radiolysis effects; and Gamma Radiation -- none and 1.8 x 10 6 R/hr. The results of this work are part of the body of information needed for understanding the degradation of the A1 SNF waste form in a direct disposal system in the federal repository. It will provide the basis for data input to the ongoing performance assessment and criticality safety analyses. Additional testing of uranium-aluminum fuel materials at uranium contents typical of high enriched and low enriched fuels is being initiated to provide the data needed for the development of empirical models

Analyses of the transportation of spent research reactor fuel in the United States

International Nuclear Information System (INIS)

Cashwell, J.W.; Neuhauser, K.S.

1989-01-01

The Transportation Technology Center at Sandia National Laboratories has analyzed the impacts of transportation of research reactor spent fuel from US and foreign reactors for the US Department of Energy (DOE) Office of Defense Programs. This effort represents the first comprehensive analytical evaluation of the risks of transporting high-, medium-, and low-enriched uranium spent research reactor fuel by both sea and land. Two separate shipment programs have been analyzed: the shipment of research reactor spent fuel from Taiwan to the US (Fuel Movement Program), and the return of research reactor spent fuels of US origin from foreign and domestic reactors (Research Reactor Fuel Return Program). In order to perform these analyses, a comprehensive methodology for analyzing the probabilities and consequences of transportation in coastal waters and port facilities, handling at the port, and shipment by truck to reprocessing facilities was developed. The Taiwanese fuel consists of low-burnup aluminum-clad metallic uranium research reactor spent fuel; the other fuels are primarily aluminum-clad oxide fuels. The Fuel Movement Program is ongoing, while the Fuel Return Program addresses future shipments over a ten-year period. The operational aspects of the Taiwanese shipments have been uniform, but several possible shipping configurations are possible for the Fuel Return Program shipments. Comprehensive assessments, which bound the impacts of spent fuel transport, demonstrate that when shipments are made in compliance with applicable regulations, the risks for all such transport are low. For comparison with previously licensed transport activities and to provide continuity with earlier analyses, the results for shipment of 150-day-old commercial pressurized water reactor (PWR) spent fuel are presented as part of this study

ABA-Induced Stomatal Closure Involves ALMT4, a Phosphorylation-Dependent Vacuolar Anion Channel of Arabidopsis[OPEN

Science.gov (United States)

Baetz, Ulrike; Huck, Nicola V.; Zhang, Jingbo

2017-01-01

Stomatal pores are formed between a pair of guard cells and allow plant uptake of CO2 and water evaporation. Their aperture depends on changes in osmolyte concentration of guard cell vacuoles, specifically of K+ and Mal2−. Efflux of Mal2− from the vacuole is required for stomatal closure; however, it is not clear how the anion is released. Here, we report the identification of ALMT4 (ALUMINUM ACTIVATED MALATE TRANSPORTER4) as an Arabidopsis thaliana ion channel that can mediate Mal2− release from the vacuole and is required for stomatal closure in response to abscisic acid (ABA). Knockout mutants showed impaired stomatal closure in response to the drought stress hormone ABA and increased whole-plant wilting in response to drought and ABA. Electrophysiological data show that ALMT4 can mediate Mal2− efflux and that the channel activity is dependent on a phosphorylatable C-terminal serine. Dephosphomimetic mutants of ALMT4 S382 showed increased channel activity and Mal2− efflux. Reconstituting the active channel in almt4 mutants impaired growth and stomatal opening. Phosphomimetic mutants were electrically inactive and phenocopied the almt4 mutants. Surprisingly, S382 can be phosphorylated by mitogen-activated protein kinases in vitro. In brief, ALMT4 likely mediates Mal2− efflux during ABA-induced stomatal closure and its activity depends on phosphorylation. PMID:28874508

Inability to produce a model of dialysis encephalopathy in the rat by aluminum administration.

Science.gov (United States)

Perry, T L; Yong, V W; Godolphin, W J; Sutter, M; Hansen, S; Kish, S J; Foulks, J G; Ito, M

1987-04-01

We attempted to produce a rat model of brain aluminum toxicity in order to explore whether or not aluminum accumulation produces the neurochemical changes observed in brains of patients who die with dialysis encephalopathy. Daily subcutaneous injection of Al(OH)3 caused marked elevation of serum aluminum concentrations, but did not increase brain aluminum contents, either in rats with normal renal function, or in rats with unilateral or 5/6 nephrectomies. LiCl pretreatment, which has been reported to cause irreversible renal failure, did not impair renal function nor aid in achieving elevated brain aluminum contents. No reductions in brain contents of gamma-aminobutyric acid (GABA) or in glutamic acid decarboxylase (GAD, E.C.4.1.1.15) and choline acetyltransferase (ChAT, E.C.2.3.1.6) activities were observed in aluminum-treated rats. We conclude that the rat is not a suitable laboratory animal to explore the role of aluminum toxicity in causing the GABA and ChAT deficits present in brains of hemodialyzed human patients.

PREPARATION OF ACTINIDE-ALUMINUM ALLOYS

Science.gov (United States)

Moore, R.H.

1962-09-01

BS>A process is given for preparing alloys of aluminum with plutonium, uranium, and/or thorium by chlorinating actinide oxide dissolved in molten alkali metal chloride with hydrochloric acid, chlorine, and/or phosgene, adding aluminum metal, and passing air and/or water vapor through the mass. Actinide metal is formed and alloyed with the aluminum. After cooling to solidification, the alloy is separated from the salt. (AEC)

Activity transport in nuclear reactors

International Nuclear Information System (INIS)

Narasimhan, S.V.

2000-01-01

The chemistry of the primary coolant is such that the general material loss is immeasurably low. However, the generation of radioactive corrosion products in the coolant, their transportation and distribution to different out of core surfaces occur irrevocably through the life cycle of the reactor. This phenomena leading to the build up of radiation field, which is unique to the nuclear reactor systems, is the only major problem of any significance. Minimization of this phenomenon can be done by many ways. The processes involved in the mechanism of activity transport are quite complex and are not at all thoroughly understood. The codes that have been developed so far use many empirical coefficients for some of the rate processes, which are either partially justified by simulated experimental studies or supported theoretically. In a multi-metal system like that of the reactor, the corrosion rates or release rates need not be similar especially in reactors like PHWRs. The mechanisms involved in the formation of protective oxide coating are quite complex to model in a simplified manner. The paper brings out some these features involved in the activity transport modeling and analyses the need for extensive field related experimental work to substantiate the model. (author)

40 CFR 63.5753 - How do I calculate the combined organic HAP content of aluminum wipedown solvents and aluminum...

Science.gov (United States)

2010-07-01

... HAP content of aluminum wipedown solvents and aluminum recreational boat surface coatings? 63.5753... Standards for Hazardous Air Pollutants for Boat Manufacturing Standards for Aluminum Recreational Boat Surface Coating Operations § 63.5753 How do I calculate the combined organic HAP content of aluminum...

Casting Characteristics of High Cerium Content Aluminum Alloys

Energy Technology Data Exchange (ETDEWEB)

Weiss, D; Rios, O R; Sims, Z C; McCall, S K; Ott, R T

2017-09-05

This paper compares the castability of the near eutectic aluminum-cerium alloy system to the aluminum-silicon and aluminum-copper systems. The alloys are compared based on die filling capability, feeding characteristics and tendency to hot tear in both sand cast and permanent mold applications. The castability ranking of the binary Al–Ce systems is as good as the aluminum-silicon system with some deterioration as additional alloying elements are added. In alloy systems that use cerium in combination with common aluminum alloying elements such as silicon, magnesium and/or copper, the casting characteristics are generally better than the aluminum-copper system. In general, production systems for melting, de-gassing and other processing of aluminum-silicon or aluminum-copper alloys can be used without modification for conventional casting of aluminum-cerium alloys.

A study of aluminum-lithium alloy solidification using acoustic emission techniques. Ph.D. Thesis, 1991

Science.gov (United States)

Henkel, Daniel P.

1992-01-01

Physical phenomena associated with the solidification of an aluminum lithium alloy was characterized using acoustic emission (AE) techniques. It is shown that repeatable patterns of AE activity may be correlated to microstructural changes that occur during solidification. The influence of the experimental system on generated signals was examined in the time and frequency domains. The analysis was used to show how an AE signal from solidifying aluminum is changed by each component in the detection system to produce a complex waveform. Conventional AE analysis has shown that a period of high AE activity occurs in pure aluminum, an Al-Cu alloy, and the Al-Li alloy, as the last fraction of solid forms. A model attributes this to the internal stresses of grain boundary formation. An additional period of activity occurs as the last fraction of solid forms, but only in the two alloys. A model attributes this to the formation of interdendritic porosity which was not present in the pure aluminum. The AE waveforms were dominated by resonant effects of the waveguide and the transducer.

Aluminum industry options paper

International Nuclear Information System (INIS)

1999-10-01

In 1990, Canada's producers of aluminum (third largest in the world) emitted 10 million tonnes of carbon dioxide and equivalent, corresponding to 6.4 tonnes of greenhouse gas intensity per tonne of aluminum. In 2000, the projection is that on a business-as-usual (BAU) basis Canadian producers now producing 60 per cent more aluminum than in 1990, will emit 10.7 million tonnes of carbon dioxide and equivalent, corresponding to a GHG intensity of 4.2 tonnes per tonne of aluminum. This improvement is due to production being based largely on hydro-electricity, and partly because in general, Canadian plants are modern, with technology that is relatively GHG-friendly. The Aluminum Association of Canada estimates that based on anticipated production, and under a BAU scenario, GHG emissions from aluminum production will rise by 18 per cent by 2010 and by 30 per cent by 2020. GHG emissions could be reduced below the BAU forecast first, by new control and monitoring systems at some operations at a cost of $4.5 to 7.5 million per smelter. These systems could reduce carbon dioxide equivalent emissions by 0.8 million tonnes per year. A second alternative would require installation of breaker feeders which would further reduce perfluorocarbon (PFC) emissions by 0.9 million tonnes of carbon dioxide equivalent. Cost of the breakers feeders would be in the order of $200 million per smelter. The third option calls for the the shutting down of some of the smelters with older technology by 2015. In this scenario GHG emissions would be reduced by 2010 by 0.8 million tonnes per year of carbon dioxide equivalent. However, the cost in this case would be about $1.36 billion. The industry would support measures that would encourage the first two sets of actions, which would produce GHG emissions from aluminum production in Canada of about 10.2 million tonnes per year of carbon dioxide equivalent, or about two per cent above 1990 levels with double the aluminum production of 1990. Credit for

Corrosion Properties of Dissimilar Friction Stir Welded 6061 Aluminum and HT590 Steel

Science.gov (United States)

Seo, Bosung; Song, Kuk Hyun; Park, Kwangsuk

2018-05-01

Corrosion properties of dissimilar friction stir welded 6061 aluminum and HT590 steel were investigated to understand effects of galvanic corrosion. As cathode when coupled, HT590 was cathodically protected. However, the passivation of AA6061 made the aluminum alloy cathode temporarily, which leaded to corrosion of HT590. From the EIS analysis showing Warburg diffusion plot in Nyquist plots, it can be inferred that the stable passivation layer was formed on AA6061. However, the weld as well as HT590 did not show Warburg diffusion plot in Nyquist plots, suggesting that there was no barrier for corrosion or even if it exists, the barrier had no function for preventing and/or retarding charge transport through the passivation layer. The open circuit potential measurements showed that the potential of the weld was similar to that of HT590, which lied in the pitting region for AA6061, making the aluminum alloy part of the weld keep corrosion state. That resulted in the cracked oxide film on AA6061 of the weld, which could not play a role of corrosion barrier.

Effect of External Electric Field on Substrate Transport of a Secondary Active Transporter.

Science.gov (United States)

Zhang, Ji-Long; Zheng, Qing-Chuan; Yu, Li-Ying; Li, Zheng-Qiang; Zhang, Hong-Xing

2016-08-22

Substrate transport across a membrane accomplished by a secondary active transporter (SAT) is essential to the normal physiological function of living cells. In the present research, a series of all-atom molecular dynamics (MD) simulations under different electric field (EF) strengths was performed to investigate the effect of an external EF on the substrate transport of an SAT. The results show that EF both affects the interaction between substrate and related protein's residues by changing their conformations and tunes the timeline of the transport event, which collectively reduces the height of energy barrier for substrate transport and results in the appearance of two intermediate conformations under the existence of an external EF. Our work spotlights the crucial influence of external EFs on the substrate transport of SATs and could provide a more penetrating understanding of the substrate transport mechanism of SATs.

Layered-disk transport experiments at 1.064μm and 0.355μm

International Nuclear Information System (INIS)

Campbell, E.M.; Mead, W.C.; Turner, R.E.

1981-01-01

The results of electron transport experiments conducted at 1.064μm and 0.355μm with the Argus Laser will be presented. The experiments were conducted at a fixed absorbed intensity and pulse width of approximately 1-2x10 14 W/cm 2 and 600 psec (FWHM) respectively. Energy on target ranged from 30 to 90 joules. To explore axial transport a variable thickness beryllium layer is coated onto an aluminum substrate. The effectiveness of electron heat conduction is studied by measuring the fall-off in aluminum x-ray yield (line and continuum) as the beryllium thickness is increased. In addition to the axial transport studies, lateral conduction is examined by placing the axial transport target onto a titanium disk

Anodizing Aluminum with Frills.

Science.gov (United States)

Doeltz, Anne E.; And Others

1983-01-01

"Anodizing Aluminum" (previously reported in this journal) describes a vivid/relevant laboratory experience for general chemistry students explaining the anodizing of aluminum in sulfuric acid and constrasting it to electroplating. Additions to this procedure and the experiment in which they are used are discussed. Reactions involved are…

Scientific Background for Processing of Aluminum Waste

Science.gov (United States)

Kononchuk, Olga; Alekseev, Alexey; Zubkova, Olga; Udovitsky, Vladimir

2017-11-01

Changing the source of raw materials for producing aluminum and the emergence of a huge number of secondary alumina waste (foundry slag, sludge, spent catalysts, mineral parts of coal and others that are formed in various industrial enterprises) require the creation of scientific and theoretical foundations for their processing. In this paper, the aluminum alloys (GOST 4784-97) are used as an aluminum raw material component, containing the aluminum component produced as chips in the machine-building enterprises. The aluminum waste is a whole range of metallic aluminum alloys including elements: magnesium, copper, silica, zinc and iron. Analysis of the aluminum waste A1- Zn-Cu-Si-Fe shows that depending on the content of the metal the dissolution process of an aluminum alloy should be treated as the result of the chemical interaction of the metal with an alkaline solution. It is necessary to consider the behavior of the main components of alloys in an alkaline solution as applied to the system Na2O - Al2O3 - SiO2 - CO2 - H2O.

Individual, Social, and Environmental Correlates of Active Transportation Patterns in French Women

Directory of Open Access Journals (Sweden)

Camille Perchoux

2017-01-01

Full Text Available The objectives were (1 to define physical activity (PA and sedentary behaviors (SB patterns in daily life contexts (work, leisure, and transportation in French working women from NutriNet-Santé web-cohort and (2 to identify pattern(s of active transportation and their individual, social, and environmental correlates. 23,432 participants completed two questionnaires to evaluate PA and SB in daily life contexts and individual representations of residential neighborhood and transportation modes. Hierarchical cluster analysis was performed which identified 6 distinct movement behavior patterns: (i active occupation, high sedentary leisure, (ii sedentary occupation, low leisure, (iii sedentary transportation, (iv sedentary occupation and leisure, (v active transportation, and (vi active leisure. Multinomial logistic regressions were performed to identify correlates of the “active transportation” cluster. The perceived environmental characteristics positively associated with “active transportation” included “high availability of destinations around home,” “presence of bicycle paths,” and “low traffic.” A “positive image of walking/cycling,” the “individual feeling of being physically active,” and a “high use of active transport modes by relatives/friends” were positively related to “active transportation,” identified as a unique pattern regarding individual and environmental correlates. Identification of PA and SB context-specific patterns will help to understand movement behaviors’ complexity and to design interventions to promote active transportation in specific subgroups.

Study of nanodispersed aluminum and iron alcosols by photoacoustic spectroscopy

Science.gov (United States)

An, Vladimir; de Izarra, Charles; Saveliev, Gennady

2011-06-01

Nanodispersed aluminum and iron alcosols were prepared by ultrasonic dispersion of nanodispersed aluminum and iron powders in absolute ethanol. The photoacoustic signal (PAS) produced in modulated CO2 laser irradiation (1.026 and 1.096 kHz) of alcosols depends on the nature and method of nanoparticle fabrication and does not depend on their concentration in ethanol (within 1-5 g/l). Chemical interaction between metal nanoparticles and ethanol activated by laser irradiation or/and ultrasound is considered as the cause of the PAS.

Identifying clusters of active transportation using spatial scan statistics.

Science.gov (United States)

Huang, Lan; Stinchcomb, David G; Pickle, Linda W; Dill, Jennifer; Berrigan, David

2009-08-01

There is an intense interest in the possibility that neighborhood characteristics influence active transportation such as walking or biking. The purpose of this paper is to illustrate how a spatial cluster identification method can evaluate the geographic variation of active transportation and identify neighborhoods with unusually high/low levels of active transportation. Self-reported walking/biking prevalence, demographic characteristics, street connectivity variables, and neighborhood socioeconomic data were collected from respondents to the 2001 California Health Interview Survey (CHIS; N=10,688) in Los Angeles County (LAC) and San Diego County (SDC). Spatial scan statistics were used to identify clusters of high or low prevalence (with and without age-adjustment) and the quantity of time spent walking and biking. The data, a subset from the 2001 CHIS, were analyzed in 2007-2008. Geographic clusters of significantly high or low prevalence of walking and biking were detected in LAC and SDC. Structural variables such as street connectivity and shorter block lengths are consistently associated with higher levels of active transportation, but associations between active transportation and socioeconomic variables at the individual and neighborhood levels are mixed. Only one cluster with less time spent walking and biking among walkers/bikers was detected in LAC, and this was of borderline significance. Age-adjustment affects the clustering pattern of walking/biking prevalence in LAC, but not in SDC. The use of spatial scan statistics to identify significant clustering of health behaviors such as active transportation adds to the more traditional regression analysis that examines associations between behavior and environmental factors by identifying specific geographic areas with unusual levels of the behavior independent of predefined administrative units.

The association between access to public transportation and self-reported active commuting.

Science.gov (United States)

Djurhuus, Sune; Hansen, Henning S; Aadahl, Mette; Glümer, Charlotte

2014-12-05

Active commuting provides routine-based regular physical activity which can reduce the risk of chronic diseases. Using public transportation involves some walking or cycling to a transit stop, transfers and a walk to the end location and users of public transportation have been found to accumulate more moderate physical activity than non-users. Understanding how public transportation characteristics are associated with active transportation is thus important from a public health perspective. This study examines the associations between objective measures of access to public transportation and self-reported active commuting. Self-reported time spent either walking or cycling commuting each day and the distance to workplace were obtained for adults aged 16 to 65 in the Danish National Health Survey 2010 (n = 28,928). Access to public transportation measures were computed by combining GIS-based road network distances from home address to public transit stops an integrating their service level. Multilevel logistic regression was used to examine the association between access to public transportation measures and active commuting. Distance to bus stop, density of bus stops, and number of transport modes were all positively associated with being an active commuter and with meeting recommendations of physical activity. No significant association was found between bus services at the nearest stop and active commuting. The results highlight the importance of including detailed measurements of access to public transit in order to identify the characteristics that facilitate the use of public transportation and active commuting.

The Association between Access to Public Transportation and Self-Reported Active Commuting

Directory of Open Access Journals (Sweden)

Sune Djurhuus

2014-12-01

Full Text Available Active commuting provides routine-based regular physical activity which can reduce the risk of chronic diseases. Using public transportation involves some walking or cycling to a transit stop, transfers and a walk to the end location and users of public transportation have been found to accumulate more moderate physical activity than non-users. Understanding how public transportation characteristics are associated with active transportation is thus important from a public health perspective. This study examines the associations between objective measures of access to public transportation and self-reported active commuting. Self-reported time spent either walking or cycling commuting each day and the distance to workplace were obtained for adults aged 16 to 65 in the Danish National Health Survey 2010 (n = 28,928. Access to public transportation measures were computed by combining GIS-based road network distances from home address to public transit stops an integrating their service level. Multilevel logistic regression was used to examine the association between access to public transportation measures and active commuting. Distance to bus stop, density of bus stops, and number of transport modes were all positively associated with being an active commuter and with meeting recommendations of physical activity. No significant association was found between bus services at the nearest stop and active commuting. The results highlight the importance of including detailed measurements of access to public transit in order to identify the characteristics that facilitate the use of public transportation and active commuting.

Entropic Ratchet transport of interacting active Brownian particles

Energy Technology Data Exchange (ETDEWEB)

Ai, Bao-Quan, E-mail: aibq@hotmail.com [Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, 510006 Guangzhou (China); He, Ya-Feng [College of Physics Science and Technology, Hebei University, 071002 Baoding (China); Zhong, Wei-Rong, E-mail: wrzhong@jnu.edu.cn [Department of Physics and Siyuan Laboratory, College of Science and Engineering, Jinan University, 510632 Guangzhou (China)

2014-11-21

Directed transport of interacting active (self-propelled) Brownian particles is numerically investigated in confined geometries (entropic barriers). The self-propelled velocity can break thermodynamical equilibrium and induce the directed transport. It is found that the interaction between active particles can greatly affect the ratchet transport. For attractive particles, on increasing the interaction strength, the average velocity first decreases to its minima, then increases, and finally decreases to zero. For repulsive particles, when the interaction is very weak, there exists a critical interaction at which the average velocity is minimal, nearly tends to zero, however, for the strong interaction, the average velocity is independent of the interaction.

Entropic Ratchet transport of interacting active Brownian particles

International Nuclear Information System (INIS)

Ai, Bao-Quan; He, Ya-Feng; Zhong, Wei-Rong

2014-01-01

Directed transport of interacting active (self-propelled) Brownian particles is numerically investigated in confined geometries (entropic barriers). The self-propelled velocity can break thermodynamical equilibrium and induce the directed transport. It is found that the interaction between active particles can greatly affect the ratchet transport. For attractive particles, on increasing the interaction strength, the average velocity first decreases to its minima, then increases, and finally decreases to zero. For repulsive particles, when the interaction is very weak, there exists a critical interaction at which the average velocity is minimal, nearly tends to zero, however, for the strong interaction, the average velocity is independent of the interaction

49 CFR 37.61 - Public transportation programs and activities in existing facilities.

Science.gov (United States)

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Public transportation programs and activities in... TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Transportation Facilities § 37.61 Public transportation programs and activities in existing facilities. (a) A public entity shall operate a designated...

Synthesis of Aluminum-Aluminum Nitride Nanocomposites by a Gas-Liquid Reaction II. Microstructure and Mechanical Properties

Science.gov (United States)

Borgonovo, Cecilia; Makhlouf, Makhlouf M.

2016-04-01

In situ fabrication of the reinforcing particles in the metal matrix is an answer to many of the challenges encountered in manufacturing aluminum matrix nanocomposites. In this method, the nanoparticles are formed directly within the melt by means of a chemical reaction between a specially designed aluminum alloy and a gas. In this publication, we describe a process for synthesizing aluminum-aluminum nitride nanocomposites by reacting a nitrogen-containing gas with a molten aluminum-lithium alloy. We quantify the effect of the process parameters on the average particle size and particle distribution, as well as on the tendency of the particles to cluster in the alloy matrix, is quantified. Also in this publication, we present the measured room temperature and elevated temperature tensile properties of the nanocomposite material as well as its measured room temperature impact toughness.

Electrical properties of aluminum-doped zinc oxide (AZO) nanoparticles synthesized by chemical vapor synthesis

International Nuclear Information System (INIS)

Hartner, Sonja; Schulz, Christof; Wiggers, Hartmut; Ali, Moazzam; Winterer, Markus

2009-01-01

Aluminum-doped zinc oxide nanoparticles have been prepared by chemical vapor synthesis, which facilitates the incorporation of a higher percentage of dopant atoms, far above the thermodynamic solubility limit of aluminum. The electrical properties of aluminum-doped and undoped zinc oxide nanoparticles were investigated by impedance spectroscopy. The impedance is measured under hydrogen and synthetic air between 323 and 673 K. The measurements under hydrogen as well as under synthetic air show transport properties depending on temperature and doping level. Under hydrogen atmosphere, a decreasing conductivity with increasing dopant content is observed, which can be explained by enhanced scattering processes due to an increasing disorder in the nanocrystalline material. The temperature coefficient for the doped samples switches from positive temperature coefficient behavior to negative temperature coefficient behavior with increasing dopant concentration. In the presence of synthetic air, the conductivity firstly increases with increasing dopant content by six orders of magnitude. The origin of the increasing conductivity is the generation of free charge carriers upon dopant incorporation. It reaches its maximum at a concentration of 7.7% of aluminum, and drops for higher doping levels. In all cases, the conductivity under hydrogen is higher than under synthetic air and can be changed reversibly by changing the atmosphere.

Electrical properties of aluminum-doped zinc oxide (AZO) nanoparticles synthesized by chemical vapor synthesis.

Science.gov (United States)

Hartner, Sonja; Ali, Moazzam; Schulz, Christof; Winterer, Markus; Wiggers, Hartmut

2009-11-04

Aluminum-doped zinc oxide nanoparticles have been prepared by chemical vapor synthesis, which facilitates the incorporation of a higher percentage of dopant atoms, far above the thermodynamic solubility limit of aluminum. The electrical properties of aluminum-doped and undoped zinc oxide nanoparticles were investigated by impedance spectroscopy. The impedance is measured under hydrogen and synthetic air between 323 and 673 K. The measurements under hydrogen as well as under synthetic air show transport properties depending on temperature and doping level. Under hydrogen atmosphere, a decreasing conductivity with increasing dopant content is observed, which can be explained by enhanced scattering processes due to an increasing disorder in the nanocrystalline material. The temperature coefficient for the doped samples switches from positive temperature coefficient behavior to negative temperature coefficient behavior with increasing dopant concentration. In the presence of synthetic air, the conductivity firstly increases with increasing dopant content by six orders of magnitude. The origin of the increasing conductivity is the generation of free charge carriers upon dopant incorporation. It reaches its maximum at a concentration of 7.7% of aluminum, and drops for higher doping levels. In all cases, the conductivity under hydrogen is higher than under synthetic air and can be changed reversibly by changing the atmosphere.

Entropic transport of active particles driven by a transverse ac force

Energy Technology Data Exchange (ETDEWEB)

Wu, Jian-chun, E-mail: wjchun2010@163.com; Chen, Qun; Ai, Bao-quan, E-mail: aibq@scnu.edu.cn

2015-12-18

Transport of active particles is numerically investigated in a two-dimensional period channel. In the presence of a transverse ac force, the directed transport of active particles demonstrates striking behaviors. By adjusting the amplitude and the frequency of the transverse ac force, the average velocity will be influenced significantly and the direction of the transport can be reversed several times. Remarkably, it is also found that the direction of the transport varies with different self-propelled speeds. Therefore, particles with different self-propelled speeds will move to the different directions, which is able to separate particles of different self-propelled speeds. - Highlights: • A transverse ac force strongly influence the transport of active particles. • The direction of the transport can be reversed several times. • Active particles with different self-propelled speeds can be separated.

Design risk analysis comparison between low-activation composite and aluminum alloy target chamber for the National Ignition Facility

International Nuclear Information System (INIS)

Streckert, H.H.; Schleicher, R.W.

1997-01-01

The baseline design for the target chamber for the National Ignition Facility (NIF) consists of an aluminum alloy spherical shell. A low-activation composite chamber (e.g., carbon fiber/epoxy) has important advantages such as enhanced environmental and safety characteristics, improved chamber accessibility due to reduced neutron-induced radioactivity, and elimination of the concrete shield. However, it is critical to determine the design and manufacturing risk for the first application. The replacement of such a critical component requires a detailed development risk assessment. A semiquantitative approach to risk assessment has been applied to this problem based on failure modes, effects, and criticality analysis. This analysis consists of a systematic method for organizing the collective judgment of the designers to identify failure modes, estimate probabilities, judge the severity of the consequence, and illustrate risk in a matrix representation. The results of the analyses indicate that the composite chamber has a reasonably high probability of success in the NIF application. The aluminum alloy chamber, however, represents a lower risk, partially based on a more mature technology. 8 refs., 4 figs., 5 tabs

Transporting Radioactive Waste: An Engineering Activity. Grades 5-12.

Science.gov (United States)

HAZWRAP, The Hazardous Waste Remedial Actions Program.

This brochure contains an engineering activity for upper elementary, middle school, and high school students that examines the transportation of radioactive waste. The activity is designed to inform students about the existence of radioactive waste and its transportation to disposal sites. Students experiment with methods to contain the waste and…

21 CFR 73.2645 - Aluminum powder.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.2645 Section 73.2645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in identity and specifications to the requirements of...

21 CFR 582.1125 - Aluminum sulfate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

21 CFR 182.1125 - Aluminum sulfate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

Fast LIBS Identification of Aluminum Alloys

Directory of Open Access Journals (Sweden)

Tawfik W.

2007-04-01

Full Text Available Laser-induced breakdown spectroscopy (LIBS has been applied to analysis aluminum alloy targets. The plasma is generated by focusing a 300 mJ pulsed Nd: YAG laser on the target in air at atmospheric pressure. Such plasma emission spectrum was collected using a one-meter length wide band fused-silica optical fiber connected to a portable Echelle spectrometer with intensified CCD camera. Spectroscopic analysis of plasma evolution of laser produced plasmas has been characterized in terms of their spectra, electron density and electron temperature assuming the LTE and optically thin plasma conditions. The LIBS spectrum was optimized for high S/N ratio especially for trace elements. The electron temperature and density were determined using the emission intensity and stark broadening, respectively, of selected aluminum spectral lines. The values of these parameters were found to change with the aluminum alloy matrix, i.e. they could be used as a fingerprint character to distinguish between different aluminum alloy matrices using only one major element (aluminum without needing to analysis the rest of elements in the matrix. Moreover, It was found that the values of T(e and N(e decrease with increasing the trace elements concentrations in the aluminum alloy samples. The obtained results indicate that it is possible to improve the exploitation of LIBS in the remote on-line industrial monitoring application, by following up only the values of T(e and N(e for the aluminum in aluminum alloys using an optical fiber probe.

An all aluminum alloy UHV components

International Nuclear Information System (INIS)

Sugisaki, Kenzaburo

1985-01-01

An all aluminum components was developed for use with UHV system. Aluminum alloy whose advantage are little discharge gas, easy to bake out, light weight, little damage against radieactivity radiation is used. Therefore, as it is all aluminum alloy, baking is possible. Baking temperature is 150 deg C in case of not only ion pump, gate valve, angle valve but also aluminum components. Ion pump have to an ultrahigh vacuum of order 10 -9 torr can be obtained without baking, 10 -10 torr order can be obtained after 24 hour of baking. (author)

A systematic review of interventions for promoting active transportation to school.

Science.gov (United States)

Chillón, Palma; Evenson, Kelly R; Vaughn, Amber; Ward, Dianne S

2011-02-14

Active transportation to school is an important contributor to the total physical activity of children and adolescents. However, active school travel has declined over time, and interventions are needed to reverse this trend. The purpose of this paper is to review intervention studies related to active school transportation to guide future intervention research. A systematic review was conducted to identify intervention studies of active transportation to school published in the scientific literature through January 2010. Five electronic databases and a manual search were conducted. Detailed information was extracted, including a quantitative assessment comparing the effect sizes, and a qualitative assessment using an established evaluation tool. We identified 14 interventions that focused on active transportation to school. These interventions mainly focused on primary school children in the United States, Australia, and the United Kingdom. Almost all the interventions used quasi-experimental designs (10/14), and most of the interventions reported a small effect size on active transportation (6/14). More research with higher quality study designs and measures should be conducted to further evaluate interventions and to determine the most successful strategies for increasing active transportation to school. © 2011 Chillón P et al; licensee BioMed Central Ltd.

Low-temperature resistance of cyclically strained aluminum

International Nuclear Information System (INIS)

Segal, H.R.; Richard, T.G.

1977-01-01

An experimental study of the resistance changes in high-purity, reinforced aluminum due to cyclic straining is presently underway. The purpose of this work is to determine the optimum purity of aluminum to be used as a stabilizing material for superconducting magnets used for energy storage. Since pure aluminum has a low yield strength, it is not capable of supporting the stress levels in an energized magnet. Therefore, it has been bonded to a high-strength material--in this case, 6061 aluminum alloy. This bonding permits pure aluminum to be strained cyclically beyond its elastic limit with recovery of large plastic strains upon release of the load. The resistance change in this composite material is less than that of pure, unreinforced aluminum

Single-Site Tetracoordinated Aluminum Hydride Supported on Mesoporous Silica. From Dream to Reality!

KAUST Repository

Werghi, Baraa; Bendjeriou-Sedjerari, Anissa; Jedidi, Abdesslem; Abou-Hamad, Edy; Cavallo, Luigi; Basset, Jean-Marie

2016-01-01

The reaction of mesoporous silica (SBA15) dehydroxylated at 700 °C with diisobutylaluminum hydride, i-Bu2AlH, gives after thermal treatment a single-site tetrahedral aluminum hydride with high selectivity. The starting aluminum isobutyl and the final aluminum hydride have been fully characterized by FT-IR, advanced SS NMR spectroscopy (1H, 13C, multiple quanta (MQ) 2D 1H-1H, and 27Al), and elemental analysis, while DFT calculations provide a rationalization of the occurring reactivity. Trimeric i-Bu2AlH reacts selectively with surface silanols without affecting the siloxane bridges. Its analogous hydride catalyzes ethylene polymerization. Indeed, catalytic tests show that this single aluminum hydride site is active in the production of a high-density polyethylene (HDPE). © 2016 American Chemical Society.

Single-Site Tetracoordinated Aluminum Hydride Supported on Mesoporous Silica. From Dream to Reality!

KAUST Repository

Werghi, Baraa

2016-09-26

The reaction of mesoporous silica (SBA15) dehydroxylated at 700 °C with diisobutylaluminum hydride, i-Bu2AlH, gives after thermal treatment a single-site tetrahedral aluminum hydride with high selectivity. The starting aluminum isobutyl and the final aluminum hydride have been fully characterized by FT-IR, advanced SS NMR spectroscopy (1H, 13C, multiple quanta (MQ) 2D 1H-1H, and 27Al), and elemental analysis, while DFT calculations provide a rationalization of the occurring reactivity. Trimeric i-Bu2AlH reacts selectively with surface silanols without affecting the siloxane bridges. Its analogous hydride catalyzes ethylene polymerization. Indeed, catalytic tests show that this single aluminum hydride site is active in the production of a high-density polyethylene (HDPE). © 2016 American Chemical Society.

Two step novel hydrogen system using additives to enhance hydrogen release from the hydrolysis of alane and activated aluminum

Science.gov (United States)

Zidan, Ragaiy; Teprovich, Joseph A.; Motyka, Theodore

2015-12-01

A system for the generation of hydrogen for use in portable power systems is set forth utilizing a two-step process that involves the thermal decomposition of AlH.sub.3 (10 wt % H.sub.2) followed by the hydrolysis of the activated aluminum (Al*) byproduct to release additional H.sub.2. Additionally, a process in which water is added directly without prior history to the AlH.sub.3:PA composite is also disclosed.

Investigating aluminum alloy reinforced by graphene nanoflakes

Energy Technology Data Exchange (ETDEWEB)

Yan, S.J., E-mail: shaojiuyan@126.com [Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Dai, S.L.; Zhang, X.Y.; Yang, C.; Hong, Q.H.; Chen, J.Z. [Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Lin, Z.M. [Aviation Industry Corporation of China, Beijing 100022 (China)

2014-08-26

As one of the most important engineering materials, aluminum alloys have been widely applied in many fields. However, the requirement of enhancing their mechanical properties without sacrificing the ductility is always a challenge in the development of aluminum alloys. Thanks to the excellent physical and mechanical properties, graphene nanoflakes (GNFs) have been applied as promising reinforcing elements in various engineering materials, including polymers and ceramics. However, the investigation of GNFs as reinforcement phase in metals or alloys, especially in aluminum alloys, is still very limited. In this study, the aluminum alloy reinforced by GNFs was successfully prepared via powder metallurgy approach. The GNFs were mixed with aluminum alloy powders through ball milling and followed by hot isostatic pressing. The green body was then hot extruded to obtain the final GNFs reinforced aluminum alloy nanocomposite. The scanning electron microscopy and transmission electron microscope analysis show that GNFs were well dispersed in the aluminum alloy matrix and no chemical reactions were observed at the interfaces between the GNFs and aluminum alloy matrix. The mechanical properties' testing results show that with increasing filling content of GNFs, both tensile and yield strengths were remarkably increased without losing the ductility performance. These results not only provided a pathway to achieve the goal of preparing high strength aluminum alloys with excellent ductilitybut they also shed light on the development of other metal alloys reinforced by GNFs.

Nanoscale aluminum dimples for light-trapping in organic thin-films

DEFF Research Database (Denmark)

Goszczak, Arkadiusz Jaroslaw; Adam, Jost; Cielecki, Pawel Piotr

Integration of nanostructures in organic solar cells (OSCs) has been investigated intensively in the past few years as an alternative way for enhancing the power conversion efficiency of the devices. Incorporating structured electrodes in the solar cell architecture holds potential for light...... absorption improvement in the active layer of the devices. A prospective, cheap and large-scale compatible method for structuring the electrodes in OSCs arises by the use of anodic aluminum oxide (AAO) membranes. In the present work, aluminum films of high purity and low roughness are formed via e...

Metallography of pitted aluminum-clad, depleted uranium fuel

International Nuclear Information System (INIS)

Nelson, D.Z.; Howell, J.P.

1994-01-01

The storage of aluminum-clad fuel and target materials in the L-Disassembly Basin at the Savannah River Site for more than 5 years has resulted in extensive pitting corrosion of these materials. In many cases the pitting corrosion of the aluminum clad has penetrated in the uranium metal core, resulting in the release of plutonium, uranium, cesium-137, and other fission product activity to the basin water. In an effort to characterize the extent of corrosion of the Mark 31A target slugs, two unirradiated slug assemblies were removed from basin storage and sent to the Savannah River Technology Center for evaluation. This paper presents the results of the metallography and photographic documentation of this evaluation. The metallography confirmed that pitting depths varied, with the deepest pit found to be about 0.12 inches (3.05 nun). Less than 2% of the aluminum cladding was found to be breached resulting in less than 5% of the uranium surface area being affected by corrosion. The overall integrity of the target slug remained intact

Studies of aluminum in rat brain

Energy Technology Data Exchange (ETDEWEB)

Lipman, J.J.; Brill, A.B.; Som, P.; Jones, K.W.; Colowick, S.; Cholewa, M.

1985-01-01

The effects of high aluminum concentrations in rat brains were studied using /sup 14/C autoradiography to measure the uptake of /sup 14/C 2-deoxy-D-glucose (/sup 14/C-2DG) and microbeam proton-induced x-ray emission (microPIXE) with a 20-..mu..m resolution to measure concentrations of magnesium, aluminum, potassium, and calcium. The aluminum was introduced intracisternally in the form of aluminum tartrate (Al-T) while control animals were given sodium tartrate (Na-T). The /sup 14/C was administered intravenously. The animals receiving Al-T developed seizure disorders and had pathological changes that included cerebral cortical atrophy. The results showed that there was a decreased uptake of /sup 14/C-2DG in cortical regions in which increased aluminum levels were measured, i.e., there is a correlation between the aluminum in the rat brain and decreased brain glucose metabolism. A minimum detection limit of about 16 ppM (mass fraction) or 3 x 10/sup 9/ Al atoms was obtained for Al under the conditions employed. 14 refs., 4 figs., 1 tab.

Aluminum neurotoxicity in the rat brain

International Nuclear Information System (INIS)

Yumoto, S.; Ohashi, H.; Nagai, H.; Kakimi, S.; Ogawa, Y.; Iwata, Y.; Ishii, K.

1992-01-01

To investigate the etiology of Alzheimer's disease, we administered aluminum to healthy rats and examined the aluminum uptake in the brain and isolated brain cell nuclei by particle-induced X-ray emission (PIXE) analysis. Ten days after the last injection, Al was detected in the rat brain and in isolated brain cell nuclei by PIXE analysis. Al was also demonstrated in the brain after 15 months of oral aluminum administration. Moreover, Al was detected in the brain and isolated brain cell nuclei from the patients with Alzheimer's disease. Silver impregnation studies revealed that spines attached to the dendritic processes of cortical nerve cells decreased remarkably after aluminum administration. Electron microscopy revealed characteristic inclusion bodies in the hippocampal nerve cells 75 days after the injection. These morphological changes in the rat brain after the aluminum administration were similar to those reportedly observed in the brain of Alzheimer's disease patients. Our results indicate that Alzheimer's disease is caused by irreversible accumulation of aluminum in the brain, as well as in the nuclei of brain cells. (author)

Aluminum neurotoxicity in the rat brain

Energy Technology Data Exchange (ETDEWEB)

Yumoto, S [Tokyo Univ. (Japan). Faculty of Medicine; Ohashi, H; Nagai, H; Kakimi, S; Ogawa, Y; Iwata, Y; Ishii, K

1993-12-31

To investigate the etiology of Alzheimer`s disease, we administered aluminum to healthy rats and examined the aluminum uptake in the brain and isolated brain cell nuclei by particle-induced X-ray emission (PIXE) analysis. Ten days after the last injection, Al was detected in the rat brain and in isolated brain cell nuclei by PIXE analysis. Al was also demonstrated in the brain after 15 months of oral aluminum administration. Moreover, Al was detected in the brain and isolated brain cell nuclei from the patients with Alzheimer`s disease. Silver impregnation studies revealed that spines attached to the dendritic processes of cortical nerve cells decreased remarkably after aluminum administration. Electron microscopy revealed characteristic inclusion bodies in the hippocampal nerve cells 75 days after the injection. These morphological changes in the rat brain after the aluminum administration were similar to those reportedly observed in the brain of Alzheimer`s disease patients. Our results indicate that Alzheimer`s disease is caused by irreversible accumulation of aluminum in the brain, as well as in the nuclei of brain cells. (author).

Studies of aluminum in rat brain

International Nuclear Information System (INIS)

Lipman, J.J.; Brill, A.B.; Som, P.; Jones, K.W.; Colowick, S.; Cholewa, M.

1985-01-01

The effects of high aluminum concentrations in rat brains were studied using 14 C autoradiography to measure the uptake of 14 C 2-deoxy-D-glucose ( 14 C-2DG) and microbeam proton-induced x-ray emission (microPIXE) with a 20-μm resolution to measure concentrations of magnesium, aluminum, potassium, and calcium. The aluminum was introduced intracisternally in the form of aluminum tartrate (Al-T) while control animals were given sodium tartrate (Na-T). The 14 C was administered intravenously. The animals receiving Al-T developed seizure disorders and had pathological changes that included cerebral cortical atrophy. The results showed that there was a decreased uptake of 14 C-2DG in cortical regions in which increased aluminum levels were measured, i.e., there is a correlation between the aluminum in the rat brain and decreased brain glucose metabolism. A minimum detection limit of about 16 ppM (mass fraction) or 3 x 10 9 Al atoms was obtained for Al under the conditions employed. 14 refs., 4 figs., 1 tab

Presentation and exhibition activities for promoting theexportof transport services

Directory of Open Access Journals (Sweden)

Darya Vladimirovna Nesterova

2012-03-01

Full Text Available Development of presentation and exhibition activities is considered as an important factor in providing new competitive advantages at the strategic markets for exporting of transportation services. A specific role for exhibition activities as a factor to overcome market failures arose from imperfect information and incomplete markets is displayed. Exhibitions are considered as a true reflection of most market parameters, as a means to get correct information concerning market capacity and its borders, as an instrument to access to new markets. At the firm level presentation and branding activities should be considered as a modern technology (especially it concerns Russian companies which provide to hold up already existed markets and to conquer new ones. Presentation and branding activities are an effective technology to promote company trade-mark, competitive advantages for market demand increasing. Comparative analysis of the main exhibitions on transport and logistics issues is fulfilled on the data basecollected by authors. Data observes geographical distribution of transport exhibition and exhibition facilities development at several regions for the last years. The analyses allow to revealing a geographical structure of the exhibitions and its distribution by type of transport. The most promising and economically favorable exhibition areas for the promotion of Russian transport services are shown.

The Association between Access to Public Transportation and Self-Reported Active Commuting

DEFF Research Database (Denmark)

Djurhuus, Sune; Hansen, Henning S; Aadahl, Mette

2014-01-01

Active commuting provides routine-based regular physical activity which can reduce the risk of chronic diseases. Using public transportation involves some walking or cycling to a transit stop, transfers and a walk to the end location and users of public transportation have been found to accumulate...... more moderate physical activity than non-users. Understanding how public transportation characteristics are associated with active transportation is thus important from a public health perspective. This study examines the associations between objective measures of access to public transportation...... and self-reported active commuting. Self-reported time spent either walking or cycling commuting each day and the distance to workplace were obtained for adults aged 16 to 65 in the Danish National Health Survey 2010 (n = 28,928). Access to public transportation measures were computed by combining GIS...

Aluminum Hydroxide and Magnesium Hydroxide

Science.gov (United States)

Aluminum Hydroxide, Magnesium Hydroxide are antacids used together to relieve heartburn, acid indigestion, and upset stomach. They ... They combine with stomach acid and neutralize it. Aluminum Hydroxide, Magnesium Hydroxide are available without a prescription. ...

[Analysis of tartrazine aluminum lake and sunset yellow aluminum lake in foods by capillary zone electrophoresis].

Science.gov (United States)

Zhang, Yiding; Chang, Cuilan; Guo, Qilei; Cao, Hong; Bai, Yu; Liu, Huwei

2014-04-01

A novel analytical method for tartrazine aluminum lake and sunset yellow aluminum lake using capillary zone electrophoresis (CZE) was studied. The pigments contained in the color lakes were successfully separated from the aluminum matrix in the pre-treatment process, which included the following steps: dissolve the color lakes in 0.1 mol/L H2SO4, adjust the pH of the solution to 5.0, then mix it with the solution of EDTA x 2Na and heat it in a water bath, then use polyamide powder as the stationary phase of solid phase extraction to separate the pigments from the solution, and finally elute the pigments with 0.1 mol/L NaOH. The CZE conditions systematically optimized for tartrazine aluminum lake were: 48.50 cm of a fused silica capillary with 40.00 cm effective length and 50 microm i. d., the temperature controlled at 20.0 degrees C, 29.0 kV applied, HPO4(2-)-PO4(3-) (0.015 mol/L, pH 11.45) solution as running buffer, detection at 263 nm. The conditions for sunset yellow aluminum lake were: the same capillary and temperature, 25.0 kV applied, HPO4(2-)-PO4(3-) (0.025 mol/L, pH 11.45) solution as running buffer, detection at 240 nm. The limits of detection were 0.26 mg/L and 0.27 mg/L, and the linear ranges were 0.53-1.3 x 10(2) mg/L and 0.54-1.4 x 10(2) mg/L for tartrazine aluminum lake and sunset yellow aluminum lake, respectively. The RSDs were 4.3% and 5.7% (run to run, n = 6), 5.6% and 6.0% (day to day, n = 6) for tartrazine aluminum lake and sunset yellow aluminum lake, respectively. Further developments for this method could make it a routinely used method analyzing color lakes in foods.

Intrinsic Hand Muscle Activation for Grasp and Horizontal Transport

OpenAIRE

Winges, Sara A.; Kundu, Bornali; Soechting, John F.; Flanders, Martha

2007-01-01

During object manipulation, the hand and arm muscles produce internal forces on the object (grasping forces) and forces that result in external translation or rotation of the object in space (transport forces). The present study tested whether the intrinsic hand muscles are actively involved in transport as well as grasping. Intrinsic hand muscle activity increased with increasing demands for grasp stability, but also showed the timing and directional tuning patterns appropriate for actively ...

Fast LIBS Identification of Aluminum Alloys

Directory of Open Access Journals (Sweden)

Tawfik W.

2007-04-01

Full Text Available Laser-induced breakdown spectroscopy (LIBS has been applied to analysis aluminum alloy targets. The plasma is generated by focusing a 300 mJ pulsed Nd: YAG laser on the target in air at atmospheric pressure. Such plasma emission spectrum was collected using a one-meter length wide band fused-silica optical fiber connected to a portable Echelle spectrometer with intensified CCD camera. Spectroscopic analysis of plasma evolution of laser produced plasmas has been characterized in terms of their spectra, electron density and electron temperature assuming the LTE and optically thin plasma conditions. The LIBS spectrum was optimized for high S/N ratio especially for trace elements. The electron temperature and density were determined using the emission intensity and stark broadening, respectively, of selected aluminum spectral lines. The values of these parameters were found to change with the aluminum alloy matrix, i.e. they could be used as a fingerprint character to distinguish between different aluminum alloy matrices using only one major element (aluminum without needing to analysis the rest of elements in the matrix. Moreover, It was found that the values of T e and N e decrease with increasing the trace elements concentrations in the aluminum alloy samples. The obtained results indicate that it is possible to improve the exploitation of LIBS in the remote on-line industrial monitoring application, by following up only the values of T e and N e for aluminum in aluminum alloys as a marker for the correct alloying using an optical fiber probe.

Endocrine control of active sodium transport across frog skin

International Nuclear Information System (INIS)

Maetz, J.

1959-01-01

I. Action of the neurohypophyseal peptides on sodium transport. 1) On Rana Esculenta, oxytocin alone is active on the sodium transport (not vaso pressin). 2) The post hypophysis of R.e. contains an hormonal factor even more specific on Na transport (12 times more active than oxytocin). 3) This new factor must be closely related to oxytocin. II. Action of the adrenal corticoids. 1) The skin of frogs adapted to a salt-rich external medium, shows a considerable diminution in sodium uptake. 2) This decreased sodium uptake is brought back to normal by the injections of aldosterone. 3) This suggests that salt loading of amphibians (as well as mammals) inhibits the mineralocorticoid activity of the adrenals. (author) [fr

Active transportation in adult survivors of childhood cancer and neighborhood controls.

Science.gov (United States)

Slater, Megan E; Kelly, Aaron S; Sadak, Karim T; Ross, Julie A

2016-02-01

Childhood cancer survivors (CCS) are at high risk of treatment-related late effects, including cardiovascular disease and diabetes, which can be exacerbated by inadequate physical activity (PA). Previous PA interventions targeting CCS have focused on the domain of leisure-time/recreational PA. Active transportation, another domain of PA, has not been described in CCS. Therefore, this study aimed to identify active transportation behaviors, barriers, and correlates in adult CCS. We recruited 158 adult CCS and 153 controls matched on age, sex, and neighborhood for a survey regarding active transportation behaviors and perceptions. Linear and logistic regression models accounting for correlation among matched participants were used. Adult CCS engaged in similar levels of active transportation as controls (2.72 vs. 2.32 h/week, P = 0.40) despite perceiving greater health-related barriers (1.88 vs. 1.65 (measured on four-point Likert scale), P = 0.01). Marital/relationship status (odds ratio (OR) = 0.30, 95 % confidence interval (CI) = 0.11-0.81), planning/psychosocial barriers (OR = 0.15, 95 % CI = 0.04-0.53), and perceived neighborhood walkability (OR = 2.55, 95 % CI = 1.14-5.66) were correlates of active transportation among adult CCS, while objective neighborhood walkability (OR = 1.03, 95 % CI = 1.01-1.05) was a correlate among controls. Results suggest adult CCS and controls utilize active transportation at approximately equal levels. Factors other than health, including perceived neighborhood walkability, are related to active transportation behaviors to a greater degree in adult CCS. Interventions might consider promoting active transportation as a way to incorporate more PA into the daily lives of adult CCS. Such interventions will not be likely successful, however, without existing or improved neighborhood walkability/bikeability.

Active Transportation in Adult Survivors of Childhood Cancer and Neighborhood Controls

Science.gov (United States)

Slater, Megan E.; Kelly, Aaron S.; Sadak, Karim T.; Ross, Julie A.

2015-01-01

Purpose Childhood cancer survivors (CCS) are at high risk of treatment-related late effects, including cardiovascular disease and diabetes, which can be exacerbated by inadequate physical activity (PA). Previous PA interventions targeting CCS have focused on the domain of leisure-time/recreational PA. Active transportation, another domain of PA, has not been described in CCS. Therefore, this study aimed to identify active transportation behaviors, barriers, and correlates in adult CCS. Methods We recruited 158 adult CCS and 153 controls matched on age, sex, and neighborhood for a survey regarding active transportation behaviors and perceptions. Linear and logistic regression models accounting for correlation among matched participants were used. Results Adult CCS engaged in similar levels of active transportation as controls (2.72 vs. 2.32 hours/week, P=0.40) despite perceiving greater health-related barriers (1.88 vs. 1.65 (measured on four-point Likert scale), P=0.01). Marital/relationship status (odds ratio (OR)=0.30, 95% confidence interval (CI)=0.11–0.81), planning/psychosocial barriers (OR=0.15, 95% CI=0.04–0.53), and perceived neighborhood walkability (OR=2.55, 95% CI=1.14–5.66) were correlates of active transportation among adult CCS, while objective neighborhood walkability (OR=1.03, 95% CI=1.01–1.05) was a correlate among controls. Conclusions Results suggest adult CCS and controls utilize active transportation at approximately equal levels. Factors other than health, including perceived neighborhood walkability, appear to influence active transportation behaviors to a greater degree in adult CCS. Implications for Cancer Survivors Interventions might consider promoting active transportation as a way to incorporate more PA into the daily lives of adult CCS. Such interventions will not be widely successful, however, without existing or improved neighborhood walkability/bikeability. PMID:25809159

Radioluminescence of rare-earth doped aluminum oxide

Energy Technology Data Exchange (ETDEWEB)

Santiago, M.; Molina, P. [Universidad Nacional del Centro de la Provincia de Buenos Aires, Instituto de Fisica Arroyo Seco, Pinto 399, 7000 Tandil (Argentina); Barros, V. S.; Khoury, H. J.; Elihimas, D. R., E-mail: msantiag@exa.unicen.edu.ar [Universidade Federal de Pernambuco, Departamento de Energia Nuclear, Av. Prof. Luiz Freire 1000, Recife, PE 50740-540 (Brazil)

2011-10-15

Carbon-doped aluminum oxide (Al{sub 2}O{sub 3}:C) is one of the most used radioluminescence (Rl) materials for fiberoptic dosimetry due to its high efficiency and commercial availability. However, this compound presents the drawback of emitting in the spectral region, where the spurious radioluminescence of fibers is also important. In this work, the radioluminescence response of rare-earth doped Al{sub 2}O{sub 3} samples has been evaluated. The samples were prepared by mixing stoichiometric amounts of aluminum nitrate, urea and dopants with different amounts of terbium, samarium, cerium and thulium nitrates varying from 0 to 0.15 mo 1%. The influence of the different activators on the Rl spectra has been investigated in order to determine the feasibility of using these compounds for Rl fiberoptic dosimetry. (Author)

Radioluminescence of rare-earth doped aluminum oxide

International Nuclear Information System (INIS)

Santiago, M.; Molina, P.; Barros, V. S.; Khoury, H. J.; Elihimas, D. R.

2011-10-01

Carbon-doped aluminum oxide (Al 2 O 3 :C) is one of the most used radioluminescence (Rl) materials for fiberoptic dosimetry due to its high efficiency and commercial availability. However, this compound presents the drawback of emitting in the spectral region, where the spurious radioluminescence of fibers is also important. In this work, the radioluminescence response of rare-earth doped Al 2 O 3 samples has been evaluated. The samples were prepared by mixing stoichiometric amounts of aluminum nitrate, urea and dopants with different amounts of terbium, samarium, cerium and thulium nitrates varying from 0 to 0.15 mo 1%. The influence of the different activators on the Rl spectra has been investigated in order to determine the feasibility of using these compounds for Rl fiberoptic dosimetry. (Author)

FLOWSHEET FOR ALUMINUM REMOVAL FROM SLUDGE BATCH 6

International Nuclear Information System (INIS)

Pike, J.; Gillam, J.

2008-01-01

Samples of Tank 12 sludge slurry show a substantially larger fraction of aluminum than originally identified in sludge batch planning. The Liquid Waste Organization (LWO) plans to formulate Sludge Batch 6 (SB6) with about one half of the sludge slurry in Tank 12 and one half of the sludge slurry in Tank 4. LWO identified aluminum dissolution as a method to mitigate the effect of having about 50% more solids in High Level Waste (HLW) sludge than previously planned. Previous aluminum dissolution performed in a HLW tank in 1982 was performed at approximately 85 C for 5 days and dissolved nearly 80% of the aluminum in the sludge slurry. In 2008, LWO successfully dissolved 64% of the aluminum at approximately 60 C in 46 days with minimal tank modifications and using only slurry pumps as a heat source. This report establishes the technical basis and flowsheet for performing an aluminum removal process in Tank 51 for SB6 that incorporates the lessons learned from previous aluminum dissolution evolutions. For SB6, aluminum dissolution process temperature will be held at a minimum of 65 C for at least 24 days, but as long as practical or until as much as 80% of the aluminum is dissolved. As planned, an aluminum removal process can reduce the aluminum in SB6 from about 84,500 kg to as little as 17,900 kg with a corresponding reduction of total insoluble solids in the batch from 246,000 kg to 131,000 kg. The extent of the reduction may be limited by the time available to maintain Tank 51 at dissolution temperature. The range of dissolution in four weeks based on the known variability in dissolution kinetics can range from 44 to more than 80%. At 44% of the aluminum dissolved, the mass reduction is approximately 1/2 of the mass noted above, i.e., 33,300 kg of aluminum instead of 66,600 kg. Planning to reach 80% of the aluminum dissolved should allow a maximum of 81 days for dissolution and reduce the allowance if test data shows faster kinetics. 47,800 kg of the dissolved

Variability and seasonality of active transportation in USA: evidence from the 2001 NHTS

Science.gov (United States)

2011-01-01

Background Active transportation including walking and bicycling is an important source of physical activity. Promoting active transportation is a challenge for the fields of public health and transportation. Descriptive data on the predictors of active transportation, including seasonal patterns in active transportation in the US as a whole, is needed to inform interventions and policies. Methods This study analyzed monthly variation in active transportation for the US using National Household Travel Survey 2001 data. For each age group of children, adolescents, adults and elderly, logistic regression models were used to identify predictors of the odds of active transportation including gender, race/ethnicity, household income level, geographical region, urbanization level, and month. Results The probability of engaging in active transportation was generally higher for children and adolescents than for adults and the elderly. Active transportation was greater in the lower income groups (except in the elderly), was lower in the South than in other regions of the US, and was greater in areas with higher urbanization. The percentage of people using active transportation exhibited clear seasonal patterns: high during summer months and low during winter months. Children and adolescents were more sensitive to seasonality than other age groups. Women, non-Caucasians, persons with lower household income, who resided in the Midwest or Northeast, and who lived in more urbanized areas had greater seasonal variation. Conclusions These descriptive results suggest that interventions and policies that target the promotion of active transportation need to consider socio-demographic factors and seasonality. PMID:21917136

Radiation induced defects and thermoluminescence mechanism in aluminum oxide

Energy Technology Data Exchange (ETDEWEB)

Atobe, K.; Kobayashi, T.; Awata, T. [Naruto Univ. of Education, Tokushima (Japan); Okada, M. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst; Nakagawa, M. [Kagawa Univ., Faculty of Education, Takamatsu, Kagawa (Japan)

2001-01-01

The thermoluminescence of the irradiated aluminum oxides were measured to study the radiation induced defects and their behaviors. Neutron and {gamma}-ray irradiation were performed for a shingle crystal of the high purity aluminum oxide. The thermoluminescence glow curve and its activation energy were measured. The spectroscopy measurement on the thermoluminescence and the absorption are also carried out. The observed 430 and 340 nm peaks are discussed relating to the F{sup +} and F centers, respectively. Activation state of the F center transits to 3P state through 1P state by emitting phonons. Trapped electron on 3P state emits phonon of 2.9 eV (430 nm) during transition to the ground state. The above reaction can be written by the equation. F{sup +} + e {yields} (F){sup *} {yields} F + h{nu}(2.9 eV, 470 nm). (Katsuta, H.)

Activation of ion transport systems during cell volume regulation

International Nuclear Information System (INIS)

Eveloff, J.L.; Warnock, D.G.

1987-01-01

This review discusses the activation of transport pathways during volume regulation, including their characteristics, the possible biochemical pathways that may mediate the activation of transport pathways, and the relations between volume regulation and transepithelial transport in renal cells. Many cells regulate their volume when exposed to an anisotonic medium. The changes in cell volume are caused by activation of ion transport pathways, plus the accompanying osmotically driven water movement such that cell volume returns toward normal levels. The swelling of hypertonically shrunken cells is termed regulatory volume increase (RVI) and involves an influx of NaCl into the cell via either activation of Na-Cl, Na-K-2Cl cotransport systems, or Na + -H + and Cl - -HCO 3 - exchangers. The reshrinking of hypotonically swollen cells is termed regulatory volume decrease (RVD) and involves an efflux of KCl and water from the cell by activation of either separate K + and Cl - conductances, a K-Cl cotransport system, or parallel K + -H + and Cl - -HCO 3 - exchangers. The biochemical mechanisms involved in the activation of transport systems are largely unknown, however, the phosphoinositide pathway may be implicated in RVI; phorbol esters, cGMP, and Ca 2+ affect the process of volume regulation. Renal tubular cells, as well as the blood cells that transverse the medulla, are subjected to increasing osmotic gradients from the corticomedullary junction to the papillary tip, as well as changing interstitial and tubule fluid osmolarity, depending on the diuretic state of the animal. Medullary cells from the loop of Henle and the papilla can volume regulate by activating Na-K-2Cl cotransport or Na + -H + and Cl - -HCO 3 - exchange systems

Molecular and Physiological Logics of the Pyruvate-Induced Response of a Novel Transporter in Bacillus subtilis.

Science.gov (United States)

Charbonnier, Teddy; Le Coq, Dominique; McGovern, Stephen; Calabre, Magali; Delumeau, Olivier; Aymerich, Stéphane; Jules, Matthieu

2017-10-03

At the heart of central carbon metabolism, pyruvate is a pivotal metabolite in all living cells. Bacillus subtilis is able to excrete pyruvate as well as to use it as the sole carbon source. We herein reveal that ysbAB (renamed pftAB ), the only operon specifically induced in pyruvate-grown B. subtilis cells, encodes a hetero-oligomeric membrane complex which operates as a facilitated transport system specific for pyruvate, thereby defining a novel class of transporter. We demonstrate that the LytST two-component system is responsible for the induction of pftAB in the presence of pyruvate by binding of the LytT response regulator to a palindromic region upstream of pftAB We show that both glucose and malate, the preferred carbon sources for B. subtilis , trigger the binding of CcpA upstream of pftAB , which results in its catabolite repression. However, an additional CcpA-independent mechanism represses pftAB in the presence of malate. Screening a genome-wide transposon mutant library, we find that an active malic enzyme replenishing the pyruvate pool is required for this repression. We next reveal that the higher the influx of pyruvate, the stronger the CcpA-independent repression of pftAB , which suggests that intracellular pyruvate retroinhibits pftAB induction via LytST. Such a retroinhibition challenges the rational design of novel nature-inspired sensors and synthetic switches but undoubtedly offers new possibilities for the development of integrated sensor/controller circuitry. Overall, we provide evidence for a complete system of sensors, feed-forward and feedback controllers that play a major role in environmental growth of B. subtilis IMPORTANCE Pyruvate is a small-molecule metabolite ubiquitous in living cells. Several species also use it as a carbon source as well as excrete it into the environment. The bacterial systems for pyruvate import/export have yet to be discovered. Here, we identified in the model bacterium Bacillus subtilis the first import

Aluminum-silicon co-deposition by FB-CVD on austenitic stainless steel AISI 316

International Nuclear Information System (INIS)

Marulanda, J L; Perez, F J; Remolina-Millán, A

2013-01-01

Aluminum-silicon coatings were deposited on stainless steel AISI 316 in the temperature range of 540 to 560°C by CVD-FBR. It was used a fluidized bed with 2.5% silicon and 7.5% aluminum powder and 90% inert (alumina). This bed was fluidized with Ar and as an activator a mixture of HCl/H2 in ratios of 1/10 to 1/16. Furthermore, the deposition time of the coatings was varied between 45 minutes to 1.5 hours, with a 50% active gas, neutral gases 50%. Thermodynamic simulation was conducted with the Thermocalc software to get the possible compositions and amount of material deposited for the chosen conditions. The coatings presented the follow compounds FeAl 2 Si, FeAl 2 and Fe 2 Al 5 . Aluminum-silicon coatings were heat treated to improve its mechanical properties and its behavior against oxidation for the inter diffusion of the alloying elements. The heat treatment causes the aluminum diffuse into the substrate and the iron diffuse into coating surface. This leads to the transformation of the above compounds in FeAl, Al 2 FeSi, Cr 3 Si, AlFeNi and AlCrFe

Influence of short-term aluminum exposure on demineralized bone matrix induced bone formation

Energy Technology Data Exchange (ETDEWEB)

Severson, A.R. (Minnesota Univ., Duluth, MN (United States). Dept. of Anatomy and Cell Biology); Haut, C.F.; Firling, C.E. (Minnesota Univ., Duluth, MN (United States). Dept. of Biology); Huntley, T.E. (Minnesota Univ., Duluth, MN (United States). Dept. of Biochemistry and Molecular Biology)

1992-12-01

The effects of aluminum exposure on bone formation employing the demineralized bone matrix (DBM) induced bone development model were studied using 4-week-old Sprague-Dawley rats injected with a saline (control) or an aluminum chloride (experimental) solution. After 2 weeks of aluminum treatment, 20-mg portions of rat DBM were implanted subcutaneously on each side in the thoracic region of the control and experimental rats. Animals were killed 7, 12, or 21 days after implantation of the DBM and the developing plaques removed. No morphological, histochemical, or biochemical differences were apparent between plaques from day 7 control and experimental rats. Plaques from day 12 control and experimental rats exhibited cartilage formation and alkaline phosphatase activity localized in osteochondrogenic cells, chondrocytes, osteoblasts, and extracellular matrix. Unlike the plaques from control rats that contained many osteoblastic mineralizing fronts, the plaques from the 12-day experimental group had a preponderance of cartilaginous tissue, no evidence of mineralization, increased levels of alkaline phosphatase activity, and a reduced calcium content. Plaques developing for 21 days in control animals demonstrated extensive new bone formation and bone marrow development, while those in the experimental rats demonstrated unmineralized osteoid-like matrix with poorly developed bone marrow. Alkaline phosphatase activity of the plaques continued to remain high on day 21 for the control and experimental groups. Calcium levels were significantly reduced in the experimental group. These biochemical changes correlated with histochemical reductions in bone calcification. Thus, aluminum administration to rats appears to alter the differentiation and calcification of developing cartilage and bone in the DBM-induced bone formation model and suggests that aluminum by some mechanism alters the matrix calcification in growing bones. (orig.).