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Sample records for dinucleotide phosphate participates

  1. A novel twist on molecular interactions between thioredoxin and nicotinamide adenine dinucleotide phosphate-dependent thioredoxin reductase

    DEFF Research Database (Denmark)

    Kirkensgaard, Kristine Groth; Hägglund, Per; Shahpiri, Azar

    2013-01-01

    The ubiquitous disulfide reductase thioredoxin (Trx) regulates several important biological processes such as seed germination in plants. Oxidized cytosolic Trx is regenerated by nicotinamide adenine dinucleotide phosphate (NADPH)-dependent thioredoxin reductase (NTR) in a multistep transfer...... dinucleotide (FAD)-binding domain of HvNTR2 to strongly affect the interaction with Trx. In particular, Trp42 and Met43 play key roles for recognition of the endogenous HvTrxh2. Trx from Arabidopsis thaliana is also efficiently recycled by HvNTR2 but turnover in this case appears to be less dependent...

  2. Kinetic and thermodynamic study of the reaction catalyzed by glucose-6-phosphate dehydrogenase with nicotinamide adenine dinucleotide

    International Nuclear Information System (INIS)

    Martin del Campo, Julia S.; Patino, Rodrigo

    2011-01-01

    Research highlights: → The reaction catalyzed by one enzyme of the pentose phosphate pathway was studied. → A spectrophotometric method is proposed for kinetic and thermodynamic analysis. → The pH and the temperature influences are reported on physical chemical properties. → Relative concentrations of substrates are also important in the catalytic process. - Abstract: The enzyme glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49) from Leuconostoc mesenteroides has a dual coenzyme specificity with oxidized nicotinamide adenine dinucleotide (NAD ox ) and oxidized nicotinamide adenine dinucleotide phosphate as electron acceptors. The G6PD coenzyme selection is determined by the metabolic cellular prevailing conditions. In this study a kinetic and thermodynamic analysis is presented for the reaction catalyzed by G6PD from L. mesenteroides with NAD ox as coenzyme in phosphate buffer. For this work, an in situ spectrophotometric technique was employed based on the detection of one product of the reaction. Substrate and coenzyme concentrations as well as temperature and pH effects were evaluated. The apparent equilibrium constant, the Michaelis constant, and the turnover number were determined as a function of each experimental condition. The standard transformed Gibbs energy of reaction was determined from equilibrium constants at different initial conditions. For the product 6-phospho-D-glucono-1,5-lactone, a value of the standard Gibbs energy of formation is proposed, Δ f G o = -1784 ± 5 kJ mol -1 .

  3. Kinetic and thermodynamic study of the reaction catalyzed by glucose-6-phosphate dehydrogenase with nicotinamide adenine dinucleotide

    Energy Technology Data Exchange (ETDEWEB)

    Martin del Campo, Julia S. [Departamento de Fisica Aplicada, Centro de Investigacion y de Estudios Avanzados - Unidad Merida, Carretera antigua a Progreso Km. 6, A.P. 73 Cordemex, 97310, Merida, Yucatan (Mexico); Patino, Rodrigo, E-mail: rtarkus@mda.cinvestav.mx [Departamento de Fisica Aplicada, Centro de Investigacion y de Estudios Avanzados - Unidad Merida, Carretera antigua a Progreso Km. 6, A.P. 73 Cordemex, 97310, Merida, Yucatan (Mexico)

    2011-04-20

    Research highlights: {yields} The reaction catalyzed by one enzyme of the pentose phosphate pathway was studied. {yields} A spectrophotometric method is proposed for kinetic and thermodynamic analysis. {yields} The pH and the temperature influences are reported on physical chemical properties. {yields} Relative concentrations of substrates are also important in the catalytic process. - Abstract: The enzyme glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49) from Leuconostoc mesenteroides has a dual coenzyme specificity with oxidized nicotinamide adenine dinucleotide (NAD{sub ox}) and oxidized nicotinamide adenine dinucleotide phosphate as electron acceptors. The G6PD coenzyme selection is determined by the metabolic cellular prevailing conditions. In this study a kinetic and thermodynamic analysis is presented for the reaction catalyzed by G6PD from L. mesenteroides with NAD{sub ox} as coenzyme in phosphate buffer. For this work, an in situ spectrophotometric technique was employed based on the detection of one product of the reaction. Substrate and coenzyme concentrations as well as temperature and pH effects were evaluated. The apparent equilibrium constant, the Michaelis constant, and the turnover number were determined as a function of each experimental condition. The standard transformed Gibbs energy of reaction was determined from equilibrium constants at different initial conditions. For the product 6-phospho-D-glucono-1,5-lactone, a value of the standard Gibbs energy of formation is proposed, {Delta}{sub f}G{sup o} = -1784 {+-} 5 kJ mol{sup -1}.

  4. Changes in phosphorylation of adenosine phosphate and redox state of nicotinamide-adenine dinucleotide (phosphate) in Geobacter sulfurreducens in response to electron acceptor and anode potential variation

    KAUST Repository

    Rose, Nicholas D.; Regan, John M.

    2015-01-01

    © 2015 Elsevier B.V. Geobacter sulfurreducens is one of the dominant bacterial species found in biofilms growing on anodes in bioelectrochemical systems. The intracellular concentrations of reduced and oxidized forms of nicotinamide-adenine dinucleotide (NADH and NAD+, respectively) and nicotinamide-adenine dinucleotide phosphate (NADPH and NADP+, respectively) as well as adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) were measured in G. sulfurreducens using fumarate, Fe(III)-citrate, or anodes poised at different potentials (110, 10, -90, and -190mV (vs. SHE)) as the electron acceptor. The ratios of CNADH/CNAD+ (0.088±0.022) and CNADPH/CNADP+ (0.268±0.098) were similar under all anode potentials tested and with Fe(III)-citrate (reduced extracellularly). Both ratios significantly increased with fumarate as the electron acceptor (0.331±0.094 for NAD and 1.96±0.37 for NADP). The adenylate energy charge (the fraction of phosphorylation in intracellular adenosine phosphates) was maintained near 0.47 under almost all conditions. Anode-growing biofilms demonstrated a significantly higher molar ratio of ATP/ADP relative to suspended cultures grown on fumarate or Fe(III)-citrate. These results provide evidence that the cellular location of reduction and not the redox potential of the electron acceptor controls the intracellular redox potential in G. sulfurreducens and that biofilm growth alters adenylate phosphorylation.

  5. Changes in phosphorylation of adenosine phosphate and redox state of nicotinamide-adenine dinucleotide (phosphate) in Geobacter sulfurreducens in response to electron acceptor and anode potential variation

    KAUST Repository

    Rose, Nicholas D.

    2015-12-01

    © 2015 Elsevier B.V. Geobacter sulfurreducens is one of the dominant bacterial species found in biofilms growing on anodes in bioelectrochemical systems. The intracellular concentrations of reduced and oxidized forms of nicotinamide-adenine dinucleotide (NADH and NAD+, respectively) and nicotinamide-adenine dinucleotide phosphate (NADPH and NADP+, respectively) as well as adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) were measured in G. sulfurreducens using fumarate, Fe(III)-citrate, or anodes poised at different potentials (110, 10, -90, and -190mV (vs. SHE)) as the electron acceptor. The ratios of CNADH/CNAD+ (0.088±0.022) and CNADPH/CNADP+ (0.268±0.098) were similar under all anode potentials tested and with Fe(III)-citrate (reduced extracellularly). Both ratios significantly increased with fumarate as the electron acceptor (0.331±0.094 for NAD and 1.96±0.37 for NADP). The adenylate energy charge (the fraction of phosphorylation in intracellular adenosine phosphates) was maintained near 0.47 under almost all conditions. Anode-growing biofilms demonstrated a significantly higher molar ratio of ATP/ADP relative to suspended cultures grown on fumarate or Fe(III)-citrate. These results provide evidence that the cellular location of reduction and not the redox potential of the electron acceptor controls the intracellular redox potential in G. sulfurreducens and that biofilm growth alters adenylate phosphorylation.

  6. Fluorimetric study of the interaction between nicotinamide adenine dinucleotide phosphate and tetracycline-europium complex and its application

    International Nuclear Information System (INIS)

    Peng Qian; Hou Faju; Ge Xiaoxia; Jiang Chongqiu; Gong Shubo

    2005-01-01

    A new spectrofluorimetric method was developed for the determination of trace amount of nicotinamide adenine dinucleotide phosphate (NADP). Using europium (Eu 3+ )-tetracycline (TC) complex as a fluorescent probe, in the buffer solution of pH 7.60. NADP can remarkably enhance the fluorescence intensity of the Eu 3+ -TC complex at λ = 612 nm and the enhanced fluorescence intensity of Eu 3+ ion is in proportion to the concentration of NADP. Optimum conditions for the determination of NADP were also investigated. The dynamic range for the determination of NADP is 4.4 x 10 -7 to 2.2 x 10 -6 mol l -1 with detection limit of 6.9 x 10 -8 mol l -1 . This method is simple, practical and relatively free interference from coexisting substances and can be successfully applied to determination of NADP in synthetic water samples and in serum samples. Moreover, the enhancement mechanisms of the fluorescence intensity in the Eu 3+ -TC system and the Eu 3+ -TC-NADP system have been also discussed

  7. The human amygdaloid complex: a cytologic and histochemical atlas using Nissl, myelin, acetylcholinesterase and nicotinamide adenine dinucleotide phosphate diaphorase staining.

    Science.gov (United States)

    Sims, K S; Williams, R S

    1990-01-01

    We examined the distribution of acetylcholinesterase and nicotinamide adenine dinucleotide phosphate diaphorase enzyme activity in the human amygdala using histochemical techniques. Both methods revealed compartments of higher or lower enzyme activity, in cells or neuropil, which corresponded to the nuclear subdivisions of the amygdala as defined with classical Nissl and myelin methods. The boundaries between the histochemical compartments were usually so sharp that the identification of these nuclear subdivisions was enhanced. There was also variation of staining intensity within many of the nuclear subdivisions, such as the lateral and central nuclei, anterior amygdaloid area and the intercalated groups. This histochemical difference corresponded to more subtle differences in Nissl and myelin staining patterns, and suggests further structural subdivisions of potential functional significance. We present a revised scheme of anatomical parcellation of the human amygdala based upon serial analysis with all four techniques. Our expectation is that this will allow the delineation of a clearer homology between the cytoarchitectonic subdivisions of the human amygdala and those of experimental animals.

  8. Rho-kinase inhibitor and nicotinamide adenine dinucleotide phosphate oxidase inhibitor prevent impairment of endothelium-dependent cerebral vasodilation by acute cigarette smoking in rats.

    Science.gov (United States)

    Iida, Hiroki; Iida, Mami; Takenaka, Motoyasu; Fukuoka, Naokazu; Dohi, Shuji

    2008-06-01

    We previously reported that acute cigarette smoking can cause a dysfunction of endothelium-dependent vasodilation in cerebral vessels, and that blocking the angiotensin II (Ang II) type 1 (AT1) receptor with valsartan prevented this impairment. Our aim was to investigate the effects of a Rho-kinase inhibitor (fasudil) and a Nicotinamide Adenine Dinucleotide PHosphate (NADPH) oxidase inhibitor (apocynin) on smoking-induced endothelial dysfunction in cerebral arterioles. In Sprague-Dawley rats, we used a closed cranial window preparation to measure changes in pial vessel diameters following topical acetylcholine (ACh) before smoking. After one-minute smoking, we again examined the arteriolar responses to ACh. Finally, after intravenous fasudil or apocynin pre-treatment we re-examined the vasodilator responses to topical ACh (before and after cigarette smoking). Under control conditions, cerebral arterioles were dose-dependently dilated by topical ACh (10(-6) M and 10(-5) M). One hour after a one-minute smoking (1 mg-nicotine cigarette), 10(-5) M ACh constricted cerebral arterioles. However, one hour after a one-minute smoking, 10(-5) M ACh dilated cerebral pial arteries both in the fasudil pre-treatment and the apocynin pre-treatment groups, responses that were significantly different from those obtained without fasudil or apocynin pre-treatment. Thus, inhibition of Rho-kinase and NADPH oxidase activities may prevent the above smoking-induced impairment of endothelium-dependent vasodilation.

  9. Wear Particles Promote Reactive Oxygen Species-Mediated Inflammation via the Nicotinamide Adenine Dinucleotide Phosphate Oxidase Pathway in Macrophages Surrounding Loosened Implants

    Directory of Open Access Journals (Sweden)

    Weishen Chen

    2015-03-01

    Full Text Available Background/Aims: Prosthesis loosening is closely associated with chronic inflammatory cytokine secretion by macrophages, which are activated by wear particles or inflammatory stimulants such as lipopolysaccharide (LPS. Reactive oxygen species (ROS are critical regulators of inflammation, but their enzymatic sources in response to wear particles and their effects on peri-implant LPS-tolerance remain unclear. Methods: Three ROS-related enzymes—nicotinamide adenine dinucleotide phosphate oxidase (NOX-1 and -2 and catalase—were investigated in interface membrane tissues and in titanium (Ti particle-stimulated macrophages in vitro. The generation of ROS and downstream inflammatory effects were measured with or without pre-incubation with apocynin, an NOX inhibitor. Results: Pre-exposure to Ti particles attenuated NF-κB activation in LPS-stimulated macrophages, indicating that wear particles suppress immune response, which may lead to chronic inflammation. NOX-1 and -2 were highly expressed in aseptically loosened interface membranes and in macrophages stimulated with Ti particles; the particles induced a moderate amount of ROS generation, NF-κB activation, and TNF-a secretion in macrophages, and these effects were suppressed by apocynin. Conclusion: Wear particles induce ROS generation through the NOX signaling pathway, resulting in persistent inflammation and delayed loosening. Thus, the suppression of NOX activity may be a useful strategy for preventing prosthesis loosening.

  10. Spectroscopy and Speciation Studies on the Interactions of Aluminum (III with Ciprofloxacin and β-Nicotinamide Adenine Dinucleotide Phosphate in Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Xiaodi Yang

    2012-08-01

    Full Text Available In this study, both experimental and theoretical approaches, including absorption spectra, fluorescence emission spectra, 1H- and 31P-NMR, electrospray ionization mass spectrometry (ESI-MS, pH-potentiometry and theoretical approaches using the BEST & SPE computer programs were applied to study the competitive complexation between ciprofloxacin (CIP and b-nicotinamide adenine dinucleotide phosphate (NADP with aluminum (III in aqueous solutions. Rank annihilation factor analysis (RAFA was used to analyze the absorption and fluorescence emission spectra of the ligands, the binary complexes and the ternary complexes. It is found, at the mM total concentration level and pH = 7.0, the bidentate mononuclear species [Al(CIP]2+ and [Al(NADP] predominate in the aqueous solutions of the Al(III-CIP and Al(III-NADP systems, and the two complexes have similar conditional stability constants. However, the pH-potentiometry results show at the mM total concentration level and pH = 7.0, the ternary species [Al(CIP(HNADP] predominates in the ternary complex system. Comparing predicted NMR spectra with the experimental NMR results, it can be concluded that for the ternary complex, CIP binds to aluminum ion between the 3-carboxylic and 4-carbonyl groups, while the binding site of oxidized coenzyme II is through the oxygen of phosphate, which is linked to adenosine ribose, instead of pyrophosphate. The results also suggested CIP has the potential to be a probe molecular for the detection of NADP and the Al(III-NADP complexes under physiological condition.

  11. Effect of telmisartan on the expression of adiponectin receptors and nicotinamide adenine dinucleotide phosphate oxidase in the heart and aorta in type 2 diabetic rats

    Directory of Open Access Journals (Sweden)

    Guo Zhixin

    2012-08-01

    Full Text Available Abstract Background Diabetic cardiovascular disease is associated with decreased adiponectin and increased oxidative stress. This study investigated the effect of telmisartan on the expression of adiponectin receptor 2 (adipoR2 and nicotinamide adenine dinucleotide phosphate (NADPH oxidase subunits in the heart and the expression of adiponectin receptor 1 (adipoR1 in aorta in type 2 diabetic rats. Methods Type 2 diabetes was induced by high-fat and high-sugar diet and intraperitoneal injection of a low dose of streptozotocin (STZ. Heart function, adipoR2, p22phox, NOX4, glucose transporter 4(GLUT4, monocyte chemoattractant protein-1(MCP-1 and connective tissue growth factor (CTGFin the heart, and adipoR1, MCP-1 and nuclear factor kappa B (NF-κB in aorta were analyzed in controls and diabetic rats treated with or without telmisartan (5mg/kg/d by gavage for 12 weeks. Results Heart function, plasma and myocardial adiponectin levels, the expression of myocardial adipoR2 and GLUT4 were significantly decreased in diabetic rats (P Conclusions Our results suggest that telmisartan upregulates the expression of myocardial adiponectin, its receptor 2 and GLUT4. Simultaneously, it downregulates the expression of myocardial p22phox, NOX4, MCP-1, and CTGF, contributing so to the improvement of heart function in diabetic rats. Telmisartan also induces a protective role on the vascular system by upregulating the expression of adipoR1 and downregulating the expression of MCP-1 and NF-κB in the abdominal aorta in diabetic rats.

  12. Nicotinic Acid Adenine Dinucleotide Phosphate Plays a Critical Role in Naive and Effector Murine T Cells but Not Natural Regulatory T Cells.

    Science.gov (United States)

    Ali, Ramadan A; Camick, Christina; Wiles, Katherine; Walseth, Timothy F; Slama, James T; Bhattacharya, Sumit; Giovannucci, David R; Wall, Katherine A

    2016-02-26

    Nicotinic acid adenine dinucleotide phosphate (NAADP), the most potent Ca(2+) mobilizing second messenger discovered to date, has been implicated in Ca(2+) signaling in some lymphomas and T cell clones. In contrast, the role of NAADP in Ca(2+) signaling or the identity of the Ca(2+) stores targeted by NAADP in conventional naive T cells is less clear. In the current study, we demonstrate the importance of NAADP in the generation of Ca(2+) signals in murine naive T cells. Combining live-cell imaging methods and a pharmacological approach using the NAADP antagonist Ned-19, we addressed the involvement of NAADP in the generation of Ca(2+) signals evoked by TCR stimulation and the role of this signal in downstream physiological end points such as proliferation, cytokine production, and other responses to stimulation. We demonstrated that acidic compartments in addition to the endoplasmic reticulum were the Ca(2+) stores that were sensitive to NAADP in naive T cells. NAADP was shown to evoke functionally relevant Ca(2+) signals in both naive CD4 and naive CD8 T cells. Furthermore, we examined the role of this signal in the activation, proliferation, and secretion of effector cytokines by Th1, Th2, Th17, and CD8 effector T cells. Overall, NAADP exhibited a similar profile in mediating Ca(2+) release in effector T cells as in their counterpart naive T cells and seemed to be equally important for the function of these different subsets of effector T cells. This profile was not observed for natural T regulatory cells. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. The distribution of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) in the medulla oblongata, spinal cord, cranial and spinal nerves of frog, Microhyla ornata.

    Science.gov (United States)

    Jadhao, Arun G; Biswas, Saikat P; Bhoyar, Rahul C; Pinelli, Claudia

    2017-04-01

    Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) enzymatic activity has been reported in few amphibian species. In this study, we report its unusual localization in the medulla oblongata, spinal cord, cranial nerves, spinal nerves, and ganglions of the frog, Microhyla ornata. In the rhombencephalon, at the level of facial and vagus nerves, the NADPH-d labeling was noted in the nucleus of the abducent and facial nerves, dorsal nucleus of the vestibulocochlear nerve, the nucleus of hypoglossus nerve, dorsal and lateral column nucleus, the nucleus of the solitary tract, the dorsal field of spinal grey, the lateral and medial motor fields of spinal grey and radix ventralis and dorsalis (2-10). Many ependymal cells around the lining of the fourth ventricle, both facial and vagus nerves and dorsal root ganglion, were intensely labeled with NADPH-d. Most strikingly the NADPH-d activity was seen in small and large sized motoneurons in both medial and lateral motor neuron columns on the right and left sides of the brain. This is the largest stained group observed from the caudal rhombencephalon up to the level of radix dorsalis 10 in the spinal cord. The neurons were either oval or elongated in shape with long processes and showed significant variation in the nuclear and cellular diameter. A massive NADPH-d activity in the medulla oblongata, spinal cord, and spinal nerves implied an important role of this enzyme in the neuronal signaling as well as in the modulation of motor functions in the peripheral nervous systems of the amphibians. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Nicotinic Acid Adenine Dinucleotide Phosphate Plays a Critical Role in Naive and Effector Murine T Cells but Not Natural Regulatory T Cells*

    Science.gov (United States)

    Ali, Ramadan A.; Camick, Christina; Wiles, Katherine; Walseth, Timothy F.; Slama, James T.; Bhattacharya, Sumit; Giovannucci, David R.; Wall, Katherine A.

    2016-01-01

    Nicotinic acid adenine dinucleotide phosphate (NAADP), the most potent Ca2+ mobilizing second messenger discovered to date, has been implicated in Ca2+ signaling in some lymphomas and T cell clones. In contrast, the role of NAADP in Ca2+ signaling or the identity of the Ca2+ stores targeted by NAADP in conventional naive T cells is less clear. In the current study, we demonstrate the importance of NAADP in the generation of Ca2+ signals in murine naive T cells. Combining live-cell imaging methods and a pharmacological approach using the NAADP antagonist Ned-19, we addressed the involvement of NAADP in the generation of Ca2+ signals evoked by TCR stimulation and the role of this signal in downstream physiological end points such as proliferation, cytokine production, and other responses to stimulation. We demonstrated that acidic compartments in addition to the endoplasmic reticulum were the Ca2+ stores that were sensitive to NAADP in naive T cells. NAADP was shown to evoke functionally relevant Ca2+ signals in both naive CD4 and naive CD8 T cells. Furthermore, we examined the role of this signal in the activation, proliferation, and secretion of effector cytokines by Th1, Th2, Th17, and CD8 effector T cells. Overall, NAADP exhibited a similar profile in mediating Ca2+ release in effector T cells as in their counterpart naive T cells and seemed to be equally important for the function of these different subsets of effector T cells. This profile was not observed for natural T regulatory cells. PMID:26728458

  15. Defects in Nicotinamide-adenine Dinucleotide Phosphate Oxidase Genes NOX1 and DUOX2 in Very Early Onset Inflammatory Bowel DiseaseSummary

    Directory of Open Access Journals (Sweden)

    Patti Hayes

    2015-09-01

    Full Text Available Background & Aims: Defects in intestinal innate defense systems predispose patients to inflammatory bowel disease (IBD. Reactive oxygen species (ROS generated by nicotinamide-adenine dinucleotide phosphate (NADPH oxidases in the mucosal barrier maintain gut homeostasis and defend against pathogenic attack. We hypothesized that molecular genetic defects in intestinal NADPH oxidases might be present in children with IBD. Methods: After targeted exome sequencing of epithelial NADPH oxidases NOX1 and DUOX2 on 59 children with very early onset inflammatory bowel disease (VEOIBD, the identified mutations were validated using Sanger Sequencing. A structural analysis of NOX1 and DUOX2 variants was performed by homology in silico modeling. The functional characterization included ROS generation in model cell lines and in in vivo transduced murine crypts, protein expression, intracellular localization, and cell-based infection studies with the enteric pathogens Campylobacter jejuni and enteropathogenic Escherichia coli. Results: We identified missense mutations in NOX1 (c.988G>A, p.Pro330Ser; c.967G>A, p.Asp360Asn and DUOX2 (c.4474G>A, p.Arg1211Cys; c.3631C>T, p.Arg1492Cys in 5 of 209 VEOIBD patients. The NOX1 p.Asp360Asn variant was replicated in a male Ashkenazi Jewish ulcerative colitis cohort. Patients with both NOX1 and DUOX2 variants showed abnormal Paneth cell metaplasia. All NOX1 and DUOX2 variants showed reduced ROS production compared with wild-type enzymes. Despite appropriate cellular localization and comparable pathogen-stimulated translocation of altered oxidases, cells harboring NOX1 or DUOX2 variants had defective host resistance to infection with C. jejuni. Conclusions: This study identifies the first inactivating missense variants in NOX1 and DUOX2 associated with VEOIBD. Defective ROS production from intestinal epithelial cells constitutes a risk factor for developing VEOIBD. Keywords: Inflammatory Bowel Disease, NADPH Oxidase

  16. Effects of aqueous extract of Ruta graveolens and its ingredients on cytochrome P450, uridine diphosphate (UDP-glucuronosyltransferase, and reduced nicotinamide adenine dinucleotide (phosphate (NAD(PH-quinone oxidoreductase in mice

    Directory of Open Access Journals (Sweden)

    Yune-Fang Ueng

    2015-09-01

    Full Text Available Ruta graveolens (the common rue has been used for various therapeutic purposes, including relief of rheumatism and treatment of circulatory disorder. To elucidate the effects of rue on main drug-metabolizing enzymes, effects of an aqueous extract of the aerial part of rue and its ingredients on cytochrome P450 (P450/CYP, uridine diphosphate (UDP-glucuronosyltransferase, and reduced nicotinamide adenine dinucleotide (phosphate (NAD(PH:quinone oxidoreductase were studied in C57BL/6JNarl mice. Oral administration of rue extract to males increased hepatic Cyp1a and Cyp2b activities in a dose-dependent manner. Under a 7-day treatment regimen, rue extract (0.5 g/kg induced hepatic Cyp1a and Cyp2b activities and protein levels in males and females. This treatment increased hepatic UDP-glucuronosyltransferase activity only in males. However, NAD(PH:quinone oxidoreductase activity remained unchanged. Based on the contents of rutin and furanocoumarins of mouse dose of rue extract, rutin increased hepatic Cyp1a activity and the mixture of furanocoumarins (Fmix increased Cyp2b activities in males. The mixture of rutin and Fmix increased Cyp1a and Cyp2b activities. These results revealed that rutin and Fmix contributed at least in part to the P450 induction by rue.

  17. Automated genotyping of dinucleotide repeat markers

    Energy Technology Data Exchange (ETDEWEB)

    Perlin, M.W.; Hoffman, E.P. [Carnegie Mellon Univ., Pittsburgh, PA (United States)]|[Univ. of Pittsburgh, PA (United States)

    1994-09-01

    The dinucleotide repeats (i.e., microsatellites) such as CA-repeats are a highly polymorphic, highly abundant class of PCR-amplifiable markers that have greatly streamlined genetic mapping experimentation. It is expected that over 30,000 such markers (including tri- and tetranucleotide repeats) will be characterized for routine use in the next few years. Since only size determination, and not sequencing, is required to determine alleles, in principle, dinucleotide repeat genotyping is easily performed on electrophoretic gels, and can be automated using DNA sequencers. Unfortunately, PCR stuttering with these markers generates not one band for each allele, but a pattern of bands. Since closely spaced alleles must be disambiguated by human scoring, this poses a key obstacle to full automation. We have developed methods that overcome this obstacle. Our model is that the observed data is generated by arithmetic superposition (i.e., convolution) of multiple allele patterns. By quantitatively measuring the size of each component band, and exploiting the unique stutter pattern associated with each marker, closely spaced alleles can be deconvolved; this unambiguously reconstructs the {open_quotes}true{close_quotes} allele bands, with stutter artifact removed. We used this approach in a system for automated diagnosis of (X-linked) Duchenne muscular dystrophy; four multiplexed CA-repeats within the dystrophin gene were assayed on a DNA sequencer. Our method accurately detected small variations in gel migration that shifted the allele size estimate. In 167 nonmutated alleles, 89% (149/167) showed no size variation, 9% (15/167) showed 1 bp variation, and 2% (3/167) showed 2 bp variation. We are currently developing a library of dinucleotide repeat patterns; together with our deconvolution methods, this library will enable fully automated genotyping of dinucleotide repeats from sizing data.

  18. Detection of Cyclic Dinucleotides by STING.

    Science.gov (United States)

    Du, Xiao-Xia; Su, Xiao-Dong

    2017-01-01

    STING (stimulator of interferon genes) is an essential signaling adaptor protein mediating cytosolic DNA-induced innate immunity for both microbial invasion and self-DNA leakage. STING is also a direct receptor for cytosolic cyclic dinucleotides (CDNs), including the microbial secondary messengers c-di-GMP (3',3'-cyclic di-GMP), 3',3'cGAMP (3',3'-cyclic GMP-AMP), and mammalian endogenous 2',3'cGAMP (2',3'-cyclic GMP-AMP) synthesized by cGAS (cyclic GMP-AMP synthase). Upon CDN binding, STING undergoes a conformational change to enable signal transduction by phosphorylation and finally to active IRF3 (Interferon regulatory factor 3) for type I interferon production. Here, we describe some experimental procedures such as Isothermal Titration Calorimetry and luciferase reporter assays to study the CDNs binding and activity by STING proteins.

  19. On the mechanism of action of ribonucleases: dinucleotide cleavage catalyzed by imidazole and Zn2+.

    OpenAIRE

    Breslow, R; Huang, D L; Anslyn, E

    1989-01-01

    Cyclization/cleavage of the 2-(p-nitrophenyl) phosphate ester of propylene glycol is catalyzed by imidazole and, much more effectively, by Zn2+ with imidazole. In the latter case, the mechanism involves simultaneous Lewis acid/base catalysis. Similar Zn2+ and imidazole catalysis of cyclization/cleavage is seen with the dinucleotide 3',5'-UpU (uridylyluridine). Again, the zinc system is much more effective than is catalysis by imidazole alone, and in this case simultaneous Lewis acid/base cata...

  20. Arabidopsis copper transport protein COPT2 participates in the cross talk between iron deficiency responses and low-phosphate signaling.

    Science.gov (United States)

    Perea-García, Ana; Garcia-Molina, Antoni; Andrés-Colás, Nuria; Vera-Sirera, Francisco; Pérez-Amador, Miguel A; Puig, Sergi; Peñarrubia, Lola

    2013-05-01

    Copper and iron are essential micronutrients for most living organisms because they participate as cofactors in biological processes, including respiration, photosynthesis, and oxidative stress protection. In many eukaryotic organisms, including yeast (Saccharomyces cerevisiae) and mammals, copper and iron homeostases are highly interconnected; yet, such interdependence is not well established in higher plants. Here, we propose that COPT2, a high-affinity copper transport protein, functions under copper and iron deficiencies in Arabidopsis (Arabidopsis thaliana). COPT2 is a plasma membrane protein that functions in copper acquisition and distribution. Characterization of the COPT2 expression pattern indicates a synergic response to copper and iron limitation in roots. We characterized a knockout of COPT2, copt2-1, that leads to increased resistance to simultaneous copper and iron deficiencies, measured as reduced leaf chlorosis and improved maintenance of the photosynthetic apparatus. We propose that COPT2 could play a dual role under iron deficiency. First, COPT2 participates in the attenuation of copper deficiency responses driven by iron limitation, possibly to minimize further iron consumption. Second, global expression analyses of copt2-1 versus wild-type Arabidopsis plants indicate that low-phosphate responses increase in the mutant. These results open up new biotechnological approaches to fight iron deficiency in crops.

  1. Participation of glyceraldehyde-3-phosphate dehydrogenase in the regulation of 2,3-diphosphoglycerate level in erythrocytes.

    Science.gov (United States)

    Fokina, K V; Yazykova, M Y; Danshina, P V; Schmalhausen, E V; Muronetz, V I

    2000-04-01

    Data are presented concerning the possible participation of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in regulation of the glycolytic pathway and the level of 2,3-diphosphoglycerate in erythrocytes. Experimental support has been obtained for the hypothesis according to which a mild oxidation of GAPDH must result in acceleration of glycolysis and in decrease in the level of 2, 3-diphosphoglycerate due to the acyl phosphatase activity of the mildly oxidized enzyme. Incubation of erythrocytes in the presence of 1 mM hydrogen peroxide decreases 2,3-diphosphoglycerate concentration and causes accumulation of 3-phosphoglycerate. It is assumed that the acceleration of glycolysis in the presence of oxidative agents described previously by a number of authors could be attributed to the acyl phosphatase activity of GAPDH. A pH-dependent complexing of GAPDH and 3-phosphoglycerate kinase or 2, 3-diphosphoglycerate mutase is found to determine the fate of 1,3-diphosphoglycerate that serves as a substrate for the synthesis of 2,3-diphosphoglycerate as well as for the 3-phosphoglycerate kinase reaction in glycolysis. A withdrawal of the two-enzyme complexes from the erythrocyte lysates using Sepharose-bound anti-GAPDH antibodies prevents the pH-dependent accumulation of the metabolites. The role of GAPDH in the regulation of glycolysis and the level of 2,3-diphosphoglycerate in erythrocytes is discussed.

  2. Analysis of dinucleotide signatures in HIV-1 subtype B genomes

    Indian Academy of Sciences (India)

    It was also shown that the profile generated by taking all dinucleotides together ... Keywords. genome signature; DRAP; HIV-1; chaos game representation. Journal of .... be used to quantify low levels of variation as are observed within species ..... Dayton A.I., Sodroski J.G., Rosen C.A., Goh W.C. and Haseltine. W.A. 1986 ...

  3. Dinucleotide controlled null models for comparative RNA gene prediction

    Directory of Open Access Journals (Sweden)

    Gesell Tanja

    2008-05-01

    Full Text Available Abstract Background Comparative prediction of RNA structures can be used to identify functional noncoding RNAs in genomic screens. It was shown recently by Babak et al. [BMC Bioinformatics. 8:33] that RNA gene prediction programs can be biased by the genomic dinucleotide content, in particular those programs using a thermodynamic folding model including stacking energies. As a consequence, there is need for dinucleotide-preserving control strategies to assess the significance of such predictions. While there have been randomization algorithms for single sequences for many years, the problem has remained challenging for multiple alignments and there is currently no algorithm available. Results We present a program called SISSIz that simulates multiple alignments of a given average dinucleotide content. Meeting additional requirements of an accurate null model, the randomized alignments are on average of the same sequence diversity and preserve local conservation and gap patterns. We make use of a phylogenetic substitution model that includes overlapping dependencies and site-specific rates. Using fast heuristics and a distance based approach, a tree is estimated under this model which is used to guide the simulations. The new algorithm is tested on vertebrate genomic alignments and the effect on RNA structure predictions is studied. In addition, we directly combined the new null model with the RNAalifold consensus folding algorithm giving a new variant of a thermodynamic structure based RNA gene finding program that is not biased by the dinucleotide content. Conclusion SISSIz implements an efficient algorithm to randomize multiple alignments preserving dinucleotide content. It can be used to get more accurate estimates of false positive rates of existing programs, to produce negative controls for the training of machine learning based programs, or as standalone RNA gene finding program. Other applications in comparative genomics that require

  4. Dinucleotide controlled null models for comparative RNA gene prediction.

    Science.gov (United States)

    Gesell, Tanja; Washietl, Stefan

    2008-05-27

    Comparative prediction of RNA structures can be used to identify functional noncoding RNAs in genomic screens. It was shown recently by Babak et al. [BMC Bioinformatics. 8:33] that RNA gene prediction programs can be biased by the genomic dinucleotide content, in particular those programs using a thermodynamic folding model including stacking energies. As a consequence, there is need for dinucleotide-preserving control strategies to assess the significance of such predictions. While there have been randomization algorithms for single sequences for many years, the problem has remained challenging for multiple alignments and there is currently no algorithm available. We present a program called SISSIz that simulates multiple alignments of a given average dinucleotide content. Meeting additional requirements of an accurate null model, the randomized alignments are on average of the same sequence diversity and preserve local conservation and gap patterns. We make use of a phylogenetic substitution model that includes overlapping dependencies and site-specific rates. Using fast heuristics and a distance based approach, a tree is estimated under this model which is used to guide the simulations. The new algorithm is tested on vertebrate genomic alignments and the effect on RNA structure predictions is studied. In addition, we directly combined the new null model with the RNAalifold consensus folding algorithm giving a new variant of a thermodynamic structure based RNA gene finding program that is not biased by the dinucleotide content. SISSIz implements an efficient algorithm to randomize multiple alignments preserving dinucleotide content. It can be used to get more accurate estimates of false positive rates of existing programs, to produce negative controls for the training of machine learning based programs, or as standalone RNA gene finding program. Other applications in comparative genomics that require randomization of multiple alignments can be considered. SISSIz

  5. Evolution of function in the "two dinucleotide binding domains" flavoproteins.

    Directory of Open Access Journals (Sweden)

    Sunil Ojha

    2007-07-01

    Full Text Available Structural and biochemical constraints force some segments of proteins to evolve more slowly than others, often allowing identification of conserved structural or sequence motifs that can be associated with substrate binding properties, chemical mechanisms, and molecular functions. We have assessed the functional and structural constraints imposed by cofactors on the evolution of new functions in a superfamily of flavoproteins characterized by two-dinucleotide binding domains, the "two dinucleotide binding domains" flavoproteins (tDBDF superfamily. Although these enzymes catalyze many different types of oxidation/reduction reactions, each is initiated by a stereospecific hydride transfer reaction between two cofactors, a pyridine nucleotide and flavin adenine dinucleotide (FAD. Sequence and structural analysis of more than 1,600 members of the superfamily reveals new members and identifies details of the evolutionary connections among them. Our analysis shows that in all of the highly divergent families within the superfamily, these cofactors adopt a conserved configuration optimal for stereospecific hydride transfer that is stabilized by specific interactions with amino acids from several motifs distributed among both dinucleotide binding domains. The conservation of cofactor configuration in the active site restricts the pyridine nucleotide to interact with FAD from the re-side, limiting the flow of electrons from the re-side to the si-side. This directionality of electron flow constrains interactions with the different partner proteins of different families to occur on the same face of the cofactor binding domains. As a result, superimposing the structures of tDBDFs aligns not only these interacting proteins, but also their constituent electron acceptors, including heme and iron-sulfur clusters. Thus, not only are specific aspects of the cofactor-directed chemical mechanism conserved across the superfamily, the constraints they impose are

  6. Phosphatidylinositol 3-phosphate 5-kinase (PIKfyve) is an AMPK target participating in contraction-stimulated glucose uptake in skeletal muscle.

    Science.gov (United States)

    Liu, Yang; Lai, Yu-Chiang; Hill, Elaine V; Tyteca, Donatienne; Carpentier, Sarah; Ingvaldsen, Ada; Vertommen, Didier; Lantier, Louise; Foretz, Marc; Dequiedt, Franck; Courtoy, Pierre J; Erneux, Christophe; Viollet, Benoît; Shepherd, Peter R; Tavaré, Jeremy M; Jensen, Jørgen; Rider, Mark H

    2013-10-15

    PIKfyve (FYVE domain-containing phosphatidylinositol 3-phosphate 5-kinase), the lipid kinase that phosphorylates PtdIns3P to PtdIns(3,5)P2, has been implicated in insulin-stimulated glucose uptake. We investigated whether PIKfyve could also be involved in contraction/AMPK (AMP-activated protein kinase)-stimulated glucose uptake in skeletal muscle. Incubation of rat epitrochlearis muscles with YM201636, a selective PIKfyve inhibitor, reduced contraction- and AICAriboside (5-amino-4-imidazolecarboxamide riboside)-stimulated glucose uptake. Consistently, PIKfyve knockdown in C2C12 myotubes reduced AICAriboside-stimulated glucose transport. Furthermore, muscle contraction increased PtdIns(3,5)P2 levels and PIKfyve phosphorylation. AMPK phosphorylated PIKfyve at Ser307 both in vitro and in intact cells. Following subcellular fractionation, PIKfyve recovery in a crude intracellular membrane fraction was increased in contracting versus resting muscles. Also in opossum kidney cells, wild-type, but not S307A mutant, PIKfyve was recruited to endosomal vesicles in response to AMPK activation. We propose that PIKfyve activity is required for the stimulation of skeletal muscle glucose uptake by contraction/AMPK activation. PIKfyve is a new AMPK substrate whose phosphorylation at Ser307 could promote PIKfyve translocation to endosomes for PtdIns(3,5)P2 synthesis to facilitate GLUT4 (glucose transporter 4) translocation.

  7. Cyclic Dinucleotides in the Scope of the Mammalian Immune System.

    Science.gov (United States)

    Mankan, Arun K; Müller, Martina; Witte, Gregor; Hornung, Veit

    2017-01-01

    First discovered in prokaryotes and more recently in eukaryotes, cyclic dinucleotides (CDNs) constitute a unique branch of second messenger signaling systems. Within prokaryotes CDNs regulate a wide array of different biological processes, whereas in the vertebrate system CDN signaling is largely dedicated to activation of the innate immune system. In this book chapter we summarize the occurrence and signaling pathways of these small-molecule second messengers, most importantly in the scope of the mammalian immune system. In this regard, our main focus is the role of the cGAS-STING axis in the context of microbial infection and sterile inflammation and its implications for therapeutic applications.

  8. Methods for detection of methyl-CpG dinucleotides

    Science.gov (United States)

    Dunn, John J.

    2012-09-11

    The invention provides methods for enriching methyl-CpG sequences from a DNA sample. The method makes use of conversion of cytosine residues to uracil under conditions in which methyl-cytosine residues are preserved. Additional methods of the invention enable to preservation of the context of me-CpG dinucleotides. The invention also provides a recombinant, full length and substantially pure McrA protein (rMcrA) for binding and isolation of DNA fragments containing the sequence 5'-C.sup.MeCpGG-3'. Methods for making and using the rMcrA protein, and derivatives thereof are provided.

  9. Enzymatic synthesis of 13N-β-nicotinamide adenine dinucleotide

    International Nuclear Information System (INIS)

    Lambrecht, R.H.D.; Slegers, G.; Claeys, A.; Vandecasteele, C.

    1985-01-01

    Nitrogen-13-labelled β-nicotinamide adenine dinucleotide ( 13 N-NAD) is an interesting new compound for positron emission tomography. A semi-automatic production method is developed that yields a solution of 13 N-NAD of radiopharmaceutical quality, suitable for human intravenous administration. The 13 N-NAD is prepared enzymatically in one step from cyclotron-produced 13 NH 3 and nicotinic acid adenine dinucleotide (deamido-NAD). The enzyme NAD synthetase (E.C. 6.3.1.5), catalysing this reaction, is extracted and purified from Escherichia coli. The purified enzyme is immobilized by glutaraldehyde coupling to γ-aminopropylsilane-coated porous glass beads. The enzyme-loaded glass beads are packed in a column. The kinetic properties of the column are optimized. For synthetizing 13 N-NAD, the mixture of co-factors and substrates, containing 13 NH 3 , is pumped over the enzyme column. The unreacted 13 NH 3 is separated from 13 N-NAD by on-line passage over a cation exchanger. After passing over a millipore filter, a sterile solution of radiochemically pure 13 N-NAD is obtained, containing 70 mCi in 10 mL. The total synthesis time is 10 minutes. The specific activity is about 120 mCi/μmol at EOB. Quality control includes sterility and pyrogen tests, HPLC and HPTLC analysis. (author)

  10. Characterization of Two Mitochondrial Flavin Adenine Dinucleotide-Dependent Glycerol-3-Phosphate Dehydrogenases in Trypanosoma brucei

    Czech Academy of Sciences Publication Activity Database

    Škodová, Ingrid; Verner, Zdeněk; Bringaud, F.; Fabian, P.; Lukeš, Julius; Horváth, A.

    2013-01-01

    Roč. 12, č. 12 (2013), s. 1664-1673 ISSN 1535-9778 R&D Projects: GA ČR(CZ) GAP305/11/2179; GA ČR GD206/09/H026; GA MŠk LH12104 Institutional support: RVO:60077344 Keywords : alternative NADH dehydrogenase * inducible expression system * blood-stream forms * complex-I * procyclic trypanosomes * sleeping sickness * oxidase * localization * metabolism * cycle Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.179, year: 2013

  11. CpG dinucleotide frequencies reveal the role of host methylation capabilities in parvovirus evolution.

    Science.gov (United States)

    Upadhyay, Mohita; Samal, Jasmine; Kandpal, Manish; Vasaikar, Suhas; Biswas, Banhi; Gomes, James; Vivekanandan, Perumal

    2013-12-01

    Parvoviruses are rapidly evolving viruses that infect a wide range of hosts, including vertebrates and invertebrates. Extensive methylation of the parvovirus genome has been recently demonstrated. A global pattern of methylation of CpG dinucleotides is seen in vertebrate genomes, compared to "fractional" methylation patterns in invertebrate genomes. It remains unknown if the loss of CpG dinucleotides occurs in all viruses of a given DNA virus family that infect host species spanning across vertebrates and invertebrates. We investigated the link between the extent of CpG dinucleotide depletion among autonomous parvoviruses and the evolutionary lineage of the infected host. We demonstrate major differences in the relative abundance of CpG dinucleotides among autonomous parvoviruses which share similar genome organization and common ancestry, depending on the infected host species. Parvoviruses infecting vertebrate hosts had significantly lower relative abundance of CpG dinucleotides than parvoviruses infecting invertebrate hosts. The strong correlation of CpG dinucleotide depletion with the gain in TpG/CpA dinucleotides and the loss of TpA dinucleotides among parvoviruses suggests a major role for CpG methylation in the evolution of parvoviruses. Our data present evidence that links the relative abundance of CpG dinucleotides in parvoviruses to the methylation capabilities of the infected host. In sum, our findings support a novel perspective of host-driven evolution among autonomous parvoviruses.

  12. Electrochemical oxidation of dihydronicotinamide adenine dinucleotide at nitrogen-doped carbon nanotube electrodes.

    Science.gov (United States)

    Goran, Jacob M; Favela, Carlos A; Stevenson, Keith J

    2013-10-01

    Nitrogen-doped carbon nanotubes (N-CNTs) substantially lower the overpotential necessary for dihydronicotinamide adenine dinucleotide (NADH) oxidation compared to nondoped CNTs or traditional carbon electrodes such as glassy carbon (GC). We observe a 370 mV shift in the peak potential (Ep) from GC to CNTs and another 170 mV shift from CNTs to 7.4 atom % N-CNTs in a sodium phosphate buffer solution (pH 7.0) with 2.0 mM NADH (scan rate 10 mV/s). The sensitivity of 7.4 atom % N-CNTs to NADH was measured at 0.30 ± 0.04 A M(-1) cm(-2), with a limit of detection at 1.1 ± 0.3 μM and a linear range of 70 ± 10 μM poised at a low potential of -0.32 V (vs Hg/Hg2SO4). NADH fouling, known to occur to the electrode surface during NADH oxidation, was investigated by measuring both the change in Ep and the resulting loss of electrode sensitivity. NADH degradation, known to occur in phosphate buffer, was characterized by absorbance at 340 nm and correlated with the loss of NADH electroactivity. N-CNTs are further demonstrated to be an effective platform for dehydrogenase-based biosensing by allowing glucose dehydrogenase to spontaneously adsorb onto the N-CNT surface and measuring the resulting electrode's sensitivity to glucose. The glucose biosensor had a sensitivity of 0.032 ± 0.003 A M(-1) cm(-2), a limit of detection at 6 ± 1 μM, and a linear range of 440 ± 50 μM.

  13. Dinucleotide Composition in Animal RNA Viruses Is Shaped More by Virus Family than by Host Species.

    Science.gov (United States)

    Di Giallonardo, Francesca; Schlub, Timothy E; Shi, Mang; Holmes, Edward C

    2017-04-15

    Viruses use the cellular machinery of their hosts for replication. It has therefore been proposed that the nucleotide and dinucleotide compositions of viruses should match those of their host species. If this is upheld, it may then be possible to use dinucleotide composition to predict the true host species of viruses sampled in metagenomic surveys. However, it is also clear that different taxonomic groups of viruses tend to have distinctive patterns of dinucleotide composition that may be independent of host species. To determine the relative strength of the effect of host versus virus family in shaping dinucleotide composition, we performed a comparative analysis of 20 RNA virus families from 15 host groupings, spanning two animal phyla and more than 900 virus species. In particular, we determined the odds ratios for the 16 possible dinucleotides and performed a discriminant analysis to evaluate the capability of virus dinucleotide composition to predict the correct virus family or host taxon from which it was isolated. Notably, while 81% of the data analyzed here were predicted to the correct virus family, only 62% of these data were predicted to their correct subphylum/class host and a mere 32% to their correct mammalian order. Similarly, dinucleotide composition has a weak predictive power for different hosts within individual virus families. We therefore conclude that dinucleotide composition is generally uniform within a virus family but less well reflects that of its host species. This has obvious implications for attempts to accurately predict host species from virus genome sequences alone. IMPORTANCE Determining the processes that shape virus genomes is central to understanding virus evolution and emergence. One question of particular importance is why nucleotide and dinucleotide frequencies differ so markedly between viruses. In particular, it is currently unclear whether host species or virus family has the biggest impact on dinucleotide frequencies and

  14. Catalytic carbene transfer allows the direct customization of cyclic purine dinucleotides.

    Science.gov (United States)

    Fei, Na; Häussinger, Daniel; Blümli, Seraina; Laventie, Benoît-Joseph; Bizzini, Lorenzo D; Zimmermann, Kaspar; Jenal, Urs; Gillingham, Dennis

    2014-08-11

    We describe a simple method for the direct modification of nucleobases in cyclic purine dinucleotides, important signalling molecules in both prokaryotes and eukaryotes. The method tolerates all members of the cyclic dinucleotide family and could be used to modulate their function or introduce useful side-chains such as fluorophores and photo-crosslinking groups.

  15. Discrepancy variation of dinucleotide microsatellite repeats in eukaryotic genomes

    Directory of Open Access Journals (Sweden)

    HUAN GAO

    2009-01-01

    Full Text Available To address whether there are differences of variation among repeat motif types and among taxonomic groups, we present here an analysis of variation and correlation of dinucleotide microsatellite repeats in eukaryotic genomes. Ten taxonomic groups were compared, those being primates, mammalia (excluding primates and rodentia, rodentia, birds, fish, amphibians and reptiles, insects, molluscs, plants and fungi, respectively. The data used in the analysis is from the literature published in the Journal of Molecular Ecology Notes. Analysis of variation reveals that there are no significant differences between AC and AG repeat motif types. Moreover, the number of alleles correlates positively with the copy number in both AG and AC repeats. Similar conclusions can be obtained from each taxonomic group. These results strongly suggest that the increase of SSR variation is almost linear with the increase of the copy number of each repeat motif. As well, the results suggest that the variability of SSR in the genomes of low-ranking species seem to be more than that of high-ranking species, excluding primates and fungi.

  16. Depletion of CpG Dinucleotides in Papillomaviruses and Polyomaviruses: A Role for Divergent Evolutionary Pressures.

    Science.gov (United States)

    Upadhyay, Mohita; Vivekanandan, Perumal

    2015-01-01

    Papillomaviruses and polyomaviruses are small ds-DNA viruses infecting a wide-range of vertebrate hosts. Evidence supporting co-evolution of the virus with the host does not fully explain the evolutionary path of papillomaviruses and polyomaviruses. Studies analyzing CpG dinucleotide frequencies in virus genomes have provided interesting insights on virus evolution. CpG dinucleotide depletion has not been extensively studied among papillomaviruses and polyomaviruses. We sought to analyze the relative abundance of dinucleotides and the relative roles of evolutionary pressures in papillomaviruses and polyomaviruses. We studied 127 full-length sequences from papillomaviruses and 56 full-length sequences from polyomaviruses. We analyzed the relative abundance of dinucleotides, effective codon number (ENC), differences in synonymous codon usage. We examined the association, if any, between the extent of CpG dinucleotide depletion and the evolutionary lineage of the infected host. We also investigated the contribution of mutational pressure and translational selection to the evolution of papillomaviruses and polyomaviruses. All papillomaviruses and polyomaviruses are CpG depleted. Interestingly, the evolutionary lineage of the infected host determines the extent of CpG depletion among papillomaviruses and polyomaviruses. CpG dinucleotide depletion was more pronounced among papillomaviruses and polyomaviruses infecting human and other mammals as compared to those infecting birds. Our findings demonstrate that CpG depletion among papillomaviruses is linked to mutational pressure; while CpG depletion among polyomaviruses is linked to translational selection. We also present evidence that suggests methylation of CpG dinucleotides may explain, at least in part, the depletion of CpG dinucleotides among papillomaviruses but not polyomaviruses. The extent of CpG depletion among papillomaviruses and polyomaviruses is linked to the evolutionary lineage of the infected host. Our

  17. Mature Microsatellites: Mechanisms Underlying Dinucleotide Microsatellite Mutational Biases in Human Cells

    OpenAIRE

    Baptiste, Beverly A.; Ananda, Guruprasad; Strubczewski, Noelle; Lutzkanin, Andrew; Khoo, Su Jen; Srikanth, Abhinaya; Kim, Nari; Makova, Kateryna D.; Krasilnikova, Maria M.; Eckert, Kristin A.

    2013-01-01

    Dinucleotide microsatellites are dynamic DNA sequences that affect genome stability. Here, we focused on mature microsatellites, defined as pure repeats of lengths above the threshold and unlikely to mutate below it in a single mutational event. We investigated the prevalence and mutational behavior of these sequences by using human genome sequence data, human cells in culture, and purified DNA polymerases. Mature dinucleotides (?10 units) are present within exonic sequences of >350 genes, re...

  18. Efficient regeneration of NADPH in a 3-enzyme cascade reaction by in situ generation of glucose 6-phosphate from glucose and pyrophosphate

    NARCIS (Netherlands)

    Hartog, A.F.; van Herk, T.; Wever, R.

    2011-01-01

    We report here a promising method to regenerate NADPH (nicotinamide adenine dinucleotide phosphate) using the intermediate formation of glucose 6-phosphate (G6P) from glucose and pyrophosphate (PPi) catalyzed by the acid phosphatase from Shigella flexneri (PhoN-Sf). The G6P formed is used in turn by

  19. Phosphate Salts

    Science.gov (United States)

    ... body. They are involved in cell structure, energy transport and storage, vitamin function, and numerous other processes ... Phosphate-containing foods and beverages include cola, wine, beer, whole grain cereals, nuts, dairy products and some ...

  20. Reagentless phosphate ion sensor system for environmental monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, M.; Kurata, H.; Inoue, Y.; Shin, H. [Kyushu Institute of Technology, Fukuoka (Japan). Faculty of computer Science and Systems; Kubo, I. [Soka University, Tokyo (Japan). Faculty of Engineering; Nakamura, H.; Ikebukuro, K.; Karube, I. [The University of Tokyo, Tokyo (Japan). Research Center for Advanced Science and Technology

    1998-06-05

    Phosphate ion sensor system using an electrochemical detector was developed by the use of recombinant pyruvate oxidase (PyOD) from Lactobacillus plantarum, which needs no addition of thiamine pyrophosphate and flavin adenine dinucleotide for reaction. This system could detect 2 nM hydrogen peroxide. Response time for phosphate ion was 80 s and total measurement time for one sample was 3 min. Citrate buffer solution (pH 6.3) was most suitable for the measurement and optimum flow rate was 0.6 ml/min. Under these optimum conditions minimum detection limit of phosphate ion was 15 nM, which was enough for the determination of phosphate ion in dam-lake. 6 refs., 5 figs., 1 tab.

  1. Nicotinamidase participates in the salvage pathway of NAD biosynthesis in Arabidopsis.

    Science.gov (United States)

    Wang, Guodong; Pichersky, Eran

    2007-03-01

    Nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), which is derived from NAD, have important roles as a redox carriers in metabolism. A combination of de novo and salvage pathways contribute to the biosynthesis of NAD in all organisms. The pathways and enzymes of the NAD salvage pathway in yeast and animals, which diverge at nicotinamide, have been extensively studied. Yeast cells convert nicotinamide to nicotinic acid, while mammals lack the enzyme nicotinamidase and instead convert nicotinamide to nicotinamide mononucleotide. Here we show that Arabidopsis thaliana gene At2g22570 encodes a nicotinamidase, which is expressed in all tissues, with the highest levels observed in roots and stems. The 244-residue protein, designated AtNIC1, converts nicotinamide to nicotinic acid and has a Km value of 118 +/- 17 microM and a Kcat value of 0.93 +/- 0.13 sec(-1). Plants homozygous for a null AtNIC1 allele, nic1-1, have lower levels of NAD and NADP under normal growth conditions, indicating that AtNIC1 participates in a yeast-type NAD salvage pathway. Mutant plants also exhibit hypersensitivity to treatments of abscisic acid and NaCl, which is correlated with their inability to increase the cellular levels of NAD(H) under these growth conditions, as occurs in wild-type plants. We also show that the growth of the roots of wild-type but not nic1-1 mutant plants is inhibited and distorted by nicotinamide.

  2. Visualization of Nicotine Adenine Dinucleotide Redox Homeostasis with Genetically Encoded Fluorescent Sensors.

    Science.gov (United States)

    Zhao, Yuzheng; Zhang, Zhuo; Zou, Yejun; Yang, Yi

    2018-01-20

    Beyond their roles as redox currency in living organisms, pyridine dinucleotides (NAD + /NADH and NADP + /NADPH) are also precursors or cosubstrates of great significance in various physiologic and pathologic processes. Recent Advances: For many years, it was challenging to develop methodologies for monitoring pyridine dinucleotides in situ or in vivo. Recent advances in fluorescent protein-based sensors provide a rapid, sensitive, specific, and real-time readout of pyridine dinucleotide dynamics in single cells or in vivo, thereby opening a new era of pyridine dinucleotide bioimaging. In this article, we summarize the developments in genetically encoded fluorescent sensors for NAD + /NADH and NADP + /NADPH redox states, as well as their applications in life sciences and drug discovery. The strengths and weaknesses of individual sensors are also discussed. These sensors have the advantages of being specific and organelle targetable, enabling real-time monitoring and subcellular-level quantification of targeted molecules in living cells and in vivo. NAD + /NADH and NADP + /NADPH have distinct functions in metabolic and redox regulation, and thus, a comprehensive evaluation of metabolic and redox states must be multiplexed with a combination of various metabolite sensors in a single cell. Antioxid. Redox Signal. 28, 213-229.

  3. cGAS produces a 2'-5'-linked cyclic dinucleotide second messenger that activates STING.

    Science.gov (United States)

    Ablasser, Andrea; Goldeck, Marion; Cavlar, Taner; Deimling, Tobias; Witte, Gregor; Röhl, Ingo; Hopfner, Karl-Peter; Ludwig, Janos; Hornung, Veit

    2013-06-20

    Detection of cytoplasmic DNA represents one of the most fundamental mechanisms of the innate immune system to sense the presence of microbial pathogens. Moreover, erroneous detection of endogenous DNA by the same sensing mechanisms has an important pathophysiological role in certain sterile inflammatory conditions. The endoplasmic-reticulum-resident protein STING is critically required for the initiation of type I interferon signalling upon detection of cytosolic DNA of both exogenous and endogenous origin. Next to its pivotal role in DNA sensing, STING also serves as a direct receptor for the detection of cyclic dinucleotides, which function as second messenger molecules in bacteria. DNA recognition, however, is triggered in an indirect fashion that depends on a recently characterized cytoplasmic nucleotidyl transferase, termed cGAMP synthase (cGAS), which upon interaction with DNA synthesizes a dinucleotide molecule that in turn binds to and activates STING. We here show in vivo and in vitro that the cGAS-catalysed reaction product is distinct from previously characterized cyclic dinucleotides. Using a combinatorial approach based on mass spectrometry, enzymatic digestion, NMR analysis and chemical synthesis we demonstrate that cGAS produces a cyclic GMP-AMP dinucleotide, which comprises a 2'-5' and a 3'-5' phosphodiester linkage >Gp(2'-5')Ap(3'-5')>. We found that the presence of this 2'-5' linkage was required to exert potent activation of human STING. Moreover, we show that cGAS first catalyses the synthesis of a linear 2'-5'-linked dinucleotide, which is then subject to cGAS-dependent cyclization in a second step through a 3'-5' phosphodiester linkage. This 13-membered ring structure defines a novel class of second messenger molecules, extending the family of 2'-5'-linked antiviral biomolecules.

  4. Solution structure of the 3'-5' cyclic dinucleotide d. A combined NMR, UV melting, and molecular mechanics study

    International Nuclear Information System (INIS)

    Blommers, M.J.J.; Haasnoot, C.A.G.; Walters, J.A.L.I.; van der Marel, G.A.; van Boom, J.H.; Hilbers, C.W.

    1988-01-01

    The 3'-5' cyclic dinucleotide d 1 H and 13 C NMR experiments, UV-melting experiments, and molecular mechanics calculations. The 1 H and 13 C NMR spectra were analyzed by means of 2-dimensional NMR experiments. J-Coupling analysis of the 1D and 2D 1 H and 13 C spectra was used to determine the conformation of the ring systems in the molecule. It appeared that at low temperature (283 K) the deoxyribose sugars adopt a N-type conformation. The geometry is best described by an intermediate between the 3 2 T and 3 E forms. In addition, the authors were able to derive all other torsion angles in the phosphate backbone ring system, i.e., α + , β/sup t/, γ + , δ (=89/degrees/), ε/sup t/ and /zeta/ + . When the molecule is subjected to an energy minimization procedure (using the program AMBER), the sugar ring system retains, practically speaking, the torsion angles found from the NMR experiments, while the torsion angles around the glycosidic bond adopt a value of 175/degrees/ in the minimum energy conformation. UV-melting experiments indicate that two molecules can form a dimer in which the adenine bases are intercalated. The feasibility of this structure is indicated by molecular mechanics calculations. At higher temperatures the dimer is converted into separate monomers. In the monomer form the sugars exhibit S-pucker 20% of the time. Concomitantly with the conversion of the N- to the S-conformation, the torsion angles α and γ change

  5. Identification of prophages in bacterial genomes by dinucleotide relative abundance difference.

    Directory of Open Access Journals (Sweden)

    K V Srividhya

    Full Text Available BACKGROUND: Prophages are integrated viral forms in bacterial genomes that have been found to contribute to interstrain genetic variability. Many virulence-associated genes are reported to be prophage encoded. Present computational methods to detect prophages are either by identifying possible essential proteins such as integrases or by an extension of this technique, which involves identifying a region containing proteins similar to those occurring in prophages. These methods suffer due to the problem of low sequence similarity at the protein level, which suggests that a nucleotide based approach could be useful. METHODOLOGY: Earlier dinucleotide relative abundance (DRA have been used to identify regions, which deviate from the neighborhood areas, in genomes. We have used the difference in the dinucleotide relative abundance (DRAD between the bacterial and prophage DNA to aid location of DNA stretches that could be of prophage origin in bacterial genomes. Prophage sequences which deviate from bacterial regions in their dinucleotide frequencies are detected by scanning bacterial genome sequences. The method was validated using a subset of genomes with prophage data from literature reports. A web interface for prophage scan based on this method is available at http://bicmku.in:8082/prophagedb/dra.html. Two hundred bacterial genomes which do not have annotated prophages have been scanned for prophage regions using this method. CONCLUSIONS: The relative dinucleotide distribution difference helps detect prophage regions in genome sequences. The usefulness of this method is seen in the identification of 461 highly probable loci pertaining to prophages which have not been annotated so earlier. This work emphasizes the need to extend the efforts to detect and annotate prophage elements in genome sequences.

  6. Improved Model for Predicting the Free Energy Contribution of Dinucleotide Bulges to RNA Duplex Stability.

    Science.gov (United States)

    Tomcho, Jeremy C; Tillman, Magdalena R; Znosko, Brent M

    2015-09-01

    Predicting the secondary structure of RNA is an intermediate in predicting RNA three-dimensional structure. Commonly, determining RNA secondary structure from sequence uses free energy minimization and nearest neighbor parameters. Current algorithms utilize a sequence-independent model to predict free energy contributions of dinucleotide bulges. To determine if a sequence-dependent model would be more accurate, short RNA duplexes containing dinucleotide bulges with different sequences and nearest neighbor combinations were optically melted to derive thermodynamic parameters. These data suggested energy contributions of dinucleotide bulges were sequence-dependent, and a sequence-dependent model was derived. This model assigns free energy penalties based on the identity of nucleotides in the bulge (3.06 kcal/mol for two purines, 2.93 kcal/mol for two pyrimidines, 2.71 kcal/mol for 5'-purine-pyrimidine-3', and 2.41 kcal/mol for 5'-pyrimidine-purine-3'). The predictive model also includes a 0.45 kcal/mol penalty for an A-U pair adjacent to the bulge and a -0.28 kcal/mol bonus for a G-U pair adjacent to the bulge. The new sequence-dependent model results in predicted values within, on average, 0.17 kcal/mol of experimental values, a significant improvement over the sequence-independent model. This model and new experimental values can be incorporated into algorithms that predict RNA stability and secondary structure from sequence.

  7. Solution conformation of 2-aminopurine dinucleotide determined by ultraviolet two-dimensional fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Widom, Julia R; Marcus, Andrew H; Johnson, Neil P; Von Hippel, Peter H

    2013-01-01

    We have observed the conformation-dependent electronic coupling between the monomeric subunits of a dinucleotide of 2-aminopurine (2-AP), a fluorescent analogue of the nucleic acid base adenine. This was accomplished by extending two-dimensional fluorescence spectroscopy (2D FS)—a fluorescence-detected variation of 2D electronic spectroscopy—to excite molecular transitions in the ultraviolet (UV) regime. A collinear sequence of four ultrafast laser pulses centered at 323 nm was used to resonantly excite the coupled transitions of 2-AP dinucleotide. The phases of the optical pulses were continuously swept at kilohertz frequencies, and the ensuing nonlinear fluorescence was phase-synchronously detected at 370 nm. Upon optimization of a point–dipole coupling model to our data, we found that in aqueous buffer the 2-AP dinucleotide adopts an average conformation in which the purine bases are non-helically stacked (center-to-center distance R 12 = 3.5 ± 0.5 Å , twist angle θ 12 = 5° ± 5° ), which differs from the conformation of such adjacent bases in duplex DNA. These experiments establish UV–2D FS as a method for examining the local conformations of an adjacent pair of fluorescent nucleotides substituted into specific DNA or RNA constructs, which will serve as a powerful probe to interpret, in structural terms, biologically significant local conformational changes within the nucleic acid framework of protein–nucleic acid complexes. (paper)

  8. Dynamic changes in nicotinamide pyridine dinucleotide content in normal human epidermal keratinocytes and their effect on retinoic acid biosynthesis

    International Nuclear Information System (INIS)

    Pinkas-Sarafova, Adriana; Markova, N.G.; Simon, M.

    2005-01-01

    The function of many enzymes that regulate metabolism and transcription depends critically on the nicotinamide pyridine dinucleotides. To understand the role of NAD(P)(H) in physiology and pathophysiology, it is imperative to estimate both their amount and ratios in a given cell type. In human epidermis and in cultured epidermal keratinocytes, we found that the total dinucleotide content is in the low millimolar range. The dinucleotide pattern changes during proliferation and maturation of keratinocytes in culture. Differences in the concentrations of NAD(P)(H) of 1.5- to 12-fold were observed. This resulted in alteration of the NAD(P)H/NAD(P) ratio, which could impact the differential regulation of both transcriptional and metabolic processes. In support of this notion, we provide evidence that the two-step oxidation of retinol to retinoic acid, a nuclear hormone critical for epidermal homeostasis, can be regulated by the relative physiological amounts of the pyridine dinucleotides

  9. Distinctive Spectral Features of Exciton and Excimer States in the Ultrafast Electronic Deactivation of the Adenine Dinucleotide

    Science.gov (United States)

    Stuhldreier, Mayra C.; Röttger, Katharina; Temps, Friedrich

    We report the observation by transient absorption spectroscopy of distinctive spectro-temporal signatures of delocalized exciton versus relaxed, weakly bound excimer states in the ultrafast electronic deactivation after UV photoexcitation of the adenine dinucleotide.

  10. Comparative Study between topical applications liposomally entrapped DNA repair enzymes and thymidine dinucleotide as radioprotectors

    International Nuclear Information System (INIS)

    Shabon, M.H.; El-Bedewi, A.F.

    2005-01-01

    The delivery of active agents to the skin by liposome carriers received great interest during the last three decades. This is based on their potential to enclose various types of biological materials and to deliver them to diverse cell types. Recent work suggests that liposomes as vehicles for topical drug delivery may be superior to conventional preparations. Also, topical application of DNA repair enzymes to irradiated skin increases the rate of repair of DNA potentially damaged cells. Moreover, thymidine dinucleotide is a new skin photo-protective agent against non-ionizing radiation through induction of DNA repair. Gamma irradiation can produce DNA damage in human skin. DNA mutations have an important role in the development of skin cancer and precancerous skin lesions. Albino rats were irradiated with Cobalt-60 gamma radiation with different doses (0.5, 1.5, 3 Gy), and were treated by either thymidine dinucleotide or liposomally entrapped DNA repair enzymes topically 24 hours before irradiation. Evaluation was done histopathologically by H and E stain. Computerized image analyzer using Masson's trichrome stain was also done. Gamma radiation produced epidermal thinning and dermal inflammatory cells together with collagen fragmentation and clumping in a dose-dependent manner. Comparing between both thymidine dinucleotide and liposomally entrapped DNA repair enzymes pretreated and irradiated rats. Low dose irradiation (0.5 Gy) together with previous drugs showed preservation of epidermis with no inflammatory cells and also it maintained the normal architecture of collagen bundles. However, they were ineffective with higher doses. In conclusion our results may suggest that the effects of gamma radiation on the skin at low dose could be minimized by the use of these drugs before exposure

  11. The spectrum of genomic signatures: from dinucleotides to chaos game representation.

    Science.gov (United States)

    Wang, Yingwei; Hill, Kathleen; Singh, Shiva; Kari, Lila

    2005-02-14

    In the post genomic era, access to complete genome sequence data for numerous diverse species has opened multiple avenues for examining and comparing primary DNA sequence organization of entire genomes. Previously, the concept of a genomic signature was introduced with the observation of species-type specific Dinucleotide Relative Abundance Profiles (DRAPs); dinucleotides were identified as the subsequences with the greatest bias in representation in a majority of genomes. Herein, we demonstrate that DRAP is one particular genomic signature contained within a broader spectrum of signatures. Within this spectrum, an alternative genomic signature, Chaos Game Representation (CGR), provides a unique visualization of patterns in sequence organization. A genomic signature is associated with a particular integer order or subsequence length that represents a measure of the resolution or granularity in the analysis of primary DNA sequence organization. We quantitatively explore the organizational information provided by genomic signatures of different orders through different distance measures, including a novel Image Distance. The Image Distance and other existing distance measures are evaluated by comparing the phylogenetic trees they generate for 26 complete mitochondrial genomes from a diversity of species. The phylogenetic tree generated by the Image Distance is compatible with the known relatedness of species. Quantitative evaluation of the spectrum of genomic signatures may be used to ultimately gain insight into the determinants and biological relevance of the genome signatures.

  12. Dioxaphosphorinane-constrained nucleic Acid dinucleotides as tools for structural tuning of nucleic acids.

    Science.gov (United States)

    Catana, Dan-Andrei; Renard, Brice-Loïc; Maturano, Marie; Payrastre, Corinne; Tarrat, Nathalie; Escudier, Jean-Marc

    2012-01-01

    We describe a rational approach devoted to modulate the sugar-phosphate backbone geometry of nucleic acids. Constraints were generated by connecting one oxygen of the phosphate group to a carbon of the sugar moiety. The so-called dioxaphosphorinane rings were introduced at key positions along the sugar-phosphate backbone allowing the control of the six-torsion angles α to ζ defining the polymer structure. The syntheses of all the members of the D-CNA family are described, and we emphasize the effect on secondary structure stabilization of a couple of diastereoisomers of α,β-D-CNA exhibiting wether B-type canonical values or not.

  13. Signal-enhanced electrochemiluminescence immunosensor based on synergistic catalysis of nicotinamide adenine dinucleotide hydride and silver nanoparticles.

    Science.gov (United States)

    Wang, Guangjie; Jin, Feng; Dai, Nan; Zhong, Zhaoyang; Qing, Yi; Li, Mengxia; Yuan, Ruo; Wang, Dong

    2012-03-01

    A new metal-organic nanocomposite with synergistic catalysis function was prepared and developed to construct an electrochemiluminescence (ECL) immunosensor for ultrasensitive detection of tumor biomarker CA125. Silver nanoparticles (AgNPs) and nicotinamide adenine dinucleotide hydride (NADH) that can participate and catalyze the ECL reaction of Ru(bpy)(3)(2+) were employed as the metal component and the organic component to synthesize the metal-organic nanocomposite of NADH-AgNPs (NA). The novel ECL immunosensor was assembled via Ru(bpy)(3)(2+)-doped silica nanoparticles (Ru-SiO(2)) modified electrode with the NA as immune labels. First, the chitosan-suspended Ru-SiO(2) nanoparticles were cast on the gold electrode surface to immobilize the ECL probes of Ru(bpy)(3)(2+) and link gold nanoparticles. Then, the primary antibodies were loaded onto the modified electrode via the gold sulfhydryl covalent binding. After immunobinding the analytes of antigen, NA-attached secondary antibodies could be captured as a sandwich type on the electrode. Finally, based on the circularly synergistic catalysis by the silver and NADH for the solid-phase ECL of Ru(bpy)(3)(2+), the proposed immunosensor sensed the concentration of antigen. The synergistic ECL catalysis of metal-organic nanocomposite amplified response signal and pushed the detection limit down to 0.03 U ml(-1), which initiated a new ECL labeling field and has great significance for ECL immunoassays. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Parvovirus b19 DNA CpG dinucleotide methylation and epigenetic regulation of viral expression.

    Directory of Open Access Journals (Sweden)

    Francesca Bonvicini

    Full Text Available CpG DNA methylation is one of the main epigenetic modifications playing a role in the control of gene expression. For DNA viruses whose genome has the ability to integrate in the host genome or to maintain as a latent episome, a correlation has been found between the extent of DNA methylation and viral quiescence. No information is available for Parvovirus B19, a human pathogenic virus, which is capable of both lytic and persistent infections. Within Parvovirus B19 genome, the inverted terminal regions display all the characteristic signatures of a genomic CpG island; therefore we hypothesised a role of CpG dinucleotide methylation in the regulation of viral genome expression.The analysis of CpG dinucleotide methylation of Parvovirus B19 DNA was carried out by an aptly designed quantitative real-time PCR assay on bisulfite-modified DNA. The effects of CpG methylation on the regulation of viral genome expression were first investigated by transfection of either unmethylated or in vitro methylated viral DNA in a model cell line, showing that methylation of viral DNA was correlated to lower expression levels of the viral genome. Then, in the course of in vitro infections in different cellular environments, it was observed that absence of viral expression and genome replication were both correlated to increasing levels of CpG methylation of viral DNA. Finally, the presence of CpG methylation was documented in viral DNA present in bioptic samples, indicating the occurrence and a possible role of this epigenetic modification in the course of natural infections.The presence of an epigenetic level of regulation of viral genome expression, possibly correlated to the silencing of the viral genome and contributing to the maintenance of the virus in tissues, can be relevant to the balance and outcome of the different types of infection associated to Parvovirus B19.

  15. Parvovirus B19 DNA CpG Dinucleotide Methylation and Epigenetic Regulation of Viral Expression

    Science.gov (United States)

    Bonvicini, Francesca; Manaresi, Elisabetta; Di Furio, Francesca; De Falco, Luisa; Gallinella, Giorgio

    2012-01-01

    CpG DNA methylation is one of the main epigenetic modifications playing a role in the control of gene expression. For DNA viruses whose genome has the ability to integrate in the host genome or to maintain as a latent episome, a correlation has been found between the extent of DNA methylation and viral quiescence. No information is available for Parvovirus B19, a human pathogenic virus, which is capable of both lytic and persistent infections. Within Parvovirus B19 genome, the inverted terminal regions display all the characteristic signatures of a genomic CpG island; therefore we hypothesised a role of CpG dinucleotide methylation in the regulation of viral genome expression. The analysis of CpG dinucleotide methylation of Parvovirus B19 DNA was carried out by an aptly designed quantitative real-time PCR assay on bisulfite-modified DNA. The effects of CpG methylation on the regulation of viral genome expression were first investigated by transfection of either unmethylated or in vitro methylated viral DNA in a model cell line, showing that methylation of viral DNA was correlated to lower expression levels of the viral genome. Then, in the course of in vitro infections in different cellular environments, it was observed that absence of viral expression and genome replication were both correlated to increasing levels of CpG methylation of viral DNA. Finally, the presence of CpG methylation was documented in viral DNA present in bioptic samples, indicating the occurrence and a possible role of this epigenetic modification in the course of natural infections. The presence of an epigenetic level of regulation of viral genome expression, possibly correlated to the silencing of the viral genome and contributing to the maintenance of the virus in tissues, can be relevant to the balance and outcome of the different types of infection associated to Parvovirus B19. PMID:22413013

  16. Uranium from phosphate ores

    International Nuclear Information System (INIS)

    Hurst, F.J.

    1983-01-01

    The following topics are described briefly: the way phosphate fertilizers are made; how uranium is recovered in the phosphate industry; and how to detect covert uranium recovery operations in a phsophate plant

  17. Dioxaphosphorinane-Constrained Nucleic Acid Dinucleotides as Tools for Structural Tuning of Nucleic Acids

    Directory of Open Access Journals (Sweden)

    Dan-Andrei Catana

    2012-01-01

    Full Text Available We describe a rational approach devoted to modulate the sugar-phosphate backbone geometry of nucleic acids. Constraints were generated by connecting one oxygen of the phosphate group to a carbon of the sugar moiety. The so-called dioxaphosphorinane rings were introduced at key positions along the sugar-phosphate backbone allowing the control of the six-torsion angles α to ζ defining the polymer structure. The syntheses of all the members of the D-CNA family are described, and we emphasize the effect on secondary structure stabilization of a couple of diastereoisomers of α,β-D-CNA exhibiting wether B-type canonical values or not.

  18. Phosphate acquisition efficiency and phosphate starvation tolerance ...

    Indian Academy of Sciences (India)

    3Department of Genetics and Plant Breeding, College of Agriculture, Lembucherra, Tripura 799 ... vated in soil like red and lateritic or acid, with low soluble phosphate content. ..... activation of genes involved in the adaptation of Arabidopsis to.

  19. Preclinical evidence of mitochondrial nicotinamide adenine dinucleotide as an effective alarm parameter under hypoxia

    Science.gov (United States)

    Shi, Hua; Sun, Nannan; Mayevsky, Avraham; Zhang, Zhihong; Luo, Qingming

    2014-01-01

    Early detection of tissue hypoxia in the intensive care unit is essential for effective treatment. Reduced nicotinamide adenine dinucleotide (NADH) has been suggested to be the most sensitive indicator of tissue oxygenation at the mitochondrial level. However, no experimental evidence comparing the kinetics of changes in NADH and other physiological parameters has been provided. The aim of this study is to obtain the missing data in a systematic and reliable manner. We constructed four acute hypoxia models, including hypoxic hypoxia, hypemic hypoxia, circulatory hypoxia, and histogenous hypoxia, and measured NADH fluorescence, tissue reflectance, cerebral blood flow, respiration, and electrocardiography simultaneously from the induction of hypoxia until death. We found that NADH was not always the first onset parameter responding to hypoxia. The order of responses was mainly affected by the cause of hypoxia. However, NADH reached its alarm level earlier than the other monitored parameters, ranging from several seconds to >10 min. As such, we suggest that the NADH can be used as a hypoxia indicator, although the exact level that should be used must be further investigated. When the NADH alarm is detected, the body still has a chance to recover if appropriate and timely treatment is provided.

  20. Studies of yeast cell oxygenation and energetics by laser fluorometry of reduced nicotinamide adenine dinucleotide

    Science.gov (United States)

    Pan, Fu-shih; Chen, Stephen; Mintzer, Robert A.; Chen, Chin-Tu; Schumacker, Paul

    1991-03-01

    It is of fundamental importance for biological scientists to assess cellular energetics. Under aerobic conditions, the tricarboxylic acid cycle (TCA cycle) is coupled with the mitochondrial electron cascade pathway to provide the cell with energy. The nicotinamide adenine dinucleotide-conjugated pair (NAD and NADH) is the coenzyme in numerous important biomedical reactions which include several important dehydrogenase reactions in the TCA cycle. Based on Le Chatelier's principle, NADH will accumulate when this energy production mechanism is impaired. The relative amounts of NAD and NADH in a cell are defined as the redox state of the cell (Williamson et.al. 1967) which provides a valuable index of cellular energetics. The sum of the amounts of NAD and NADH in a cell may be assumed to be constant during a finite time; therefore, a reliable means of measuring the NADH concentration would provide us with a useful indicator of tissue viability. Traditionally, the quantities of NADH and NAD may be measured by chemical assay methods. We can avoid these tediois analyses by exploiting the significant difference between the ultraviolet absorption spectra of this redox pair. However, because of the opacity of biological samples and the interference of other biochemicals that also absorb ultraviolet radiation, measurement of NADH and NAD+ concentrations in vivo by absorption spectroscopy is not feasible.

  1. Predicting DNA Methylation State of CpG Dinucleotide Using Genome Topological Features and Deep Networks.

    Science.gov (United States)

    Wang, Yiheng; Liu, Tong; Xu, Dong; Shi, Huidong; Zhang, Chaoyang; Mo, Yin-Yuan; Wang, Zheng

    2016-01-22

    The hypo- or hyper-methylation of the human genome is one of the epigenetic features of leukemia. However, experimental approaches have only determined the methylation state of a small portion of the human genome. We developed deep learning based (stacked denoising autoencoders, or SdAs) software named "DeepMethyl" to predict the methylation state of DNA CpG dinucleotides using features inferred from three-dimensional genome topology (based on Hi-C) and DNA sequence patterns. We used the experimental data from immortalised myelogenous leukemia (K562) and healthy lymphoblastoid (GM12878) cell lines to train the learning models and assess prediction performance. We have tested various SdA architectures with different configurations of hidden layer(s) and amount of pre-training data and compared the performance of deep networks relative to support vector machines (SVMs). Using the methylation states of sequentially neighboring regions as one of the learning features, an SdA achieved a blind test accuracy of 89.7% for GM12878 and 88.6% for K562. When the methylation states of sequentially neighboring regions are unknown, the accuracies are 84.82% for GM12878 and 72.01% for K562. We also analyzed the contribution of genome topological features inferred from Hi-C. DeepMethyl can be accessed at http://dna.cs.usm.edu/deepmethyl/.

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

    Science.gov (United States)

    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.

  3. Role of p73 Dinucleotide Polymorphism in Prostate Cancer and p73 Protein Isoform Balance

    Directory of Open Access Journals (Sweden)

    L. Michael Carastro

    2014-01-01

    Full Text Available Background. Molecular markers for prostate cancer (PCa risks are currently lacking. Here we address the potential association of a dinucleotide polymorphism (DNP in exon 2 of the p73 gene with PCa risk/progression and discern any disruption of p73 protein isoforms levels in cells harboring a p73 DNP allele. Methods. We investigated the association between p73 DNP genotype and PCa risk/aggressiveness and survival by fitting logistic regression models in 1,292 incident cases and 682 controls. Results. Although we detected no association between p73 DNP and PCa risk, a significant inverse relationship between p73 DNP and PCa aggressiveness (AT/AT + GC/AT versus GC/GC, OR = 0.55, 95%Cl = 0.31–0.99 was detected. Also, p73 DNP is marginally associated with overall death (dominant model, HR = 0.76, 95%Cl = 0.57–1.00, P=0.053 as well as PCa specific death (HR = 0.69, 95%Cl = 0.45–1.06, P=0.09. Western blot analyses for p73 protein isoforms indicate that cells heterozygous for the p73 DNP have lower levels of ∆Np73 relative to TAp73 (P<0.001. Conclusions. Our findings are consistent with an association between p73 DNP and low risk for PCa aggressiveness by increasing the expressed TAp73/∆Np73 protein isoform ratio.

  4. Quantum Chemical Benchmark Study on 46 RNA Backbone Families Using a Dinucleotide Unit

    Czech Academy of Sciences Publication Activity Database

    Kruse, H.; Mládek, Arnošt; Gkionis, Konstantinos; Hansen, A.; Grimme, S.; Šponer, Jiří

    2015-01-01

    Roč. 11, č. 10 (2015), s. 4972-4991 ISSN 1549-9618 R&D Projects: GA ČR(CZ) GBP305/12/G034 Institutional support: RVO:68081707 Keywords : MOLECULAR-DYNAMICS SIMULATIONS * DENSITY-FUNCTIONAL THEORY * SUGAR-PHOSPHATE BACKBONE Subject RIV: BO - Biophysics Impact factor: 5.301, year: 2015

  5. Hexose-6-phosphate dehydrogenase contributes to skeletal muscle homeostasis independent of 11β-hydroxysteroid dehydrogenase type 1.

    LENUS (Irish Health Repository)

    Semjonous, Nina M

    2011-01-01

    Glucose-6-phosphate (G6P) metabolism by the enzyme hexose-6-phosphate dehydrogenase (H6PDH) within the sarcoplasmic reticulum lumen generates nicotinamide adenine dinucleotide phosphate (reduced) to provide the redox potential for the enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) to activate glucocorticoid (GC). H6PDH knockout (KO) mice have a switch in 11β-HSD1 activity, resulting in GC inactivation and hypothalamic-pituitary-adrenal axis activation. Importantly, H6PDHKO mice develop a type II fiber myopathy with abnormalities in glucose metabolism and activation of the unfolded protein response (UPR). GCs play important roles in muscle physiology, and therefore, we have examined the importance of 11β-HSD1 and GC metabolism in mediating aspects of the H6PDHKO myopathy. To achieve this, we examined 11β-HSD1\\/H6PDH double-KO (DKO) mice, in which 11β-HSD1 mediated GC inactivation is negated. In contrast to H6PDHKO mice, DKO mice GC metabolism and hypothalamic-pituitary-adrenal axis set point is similar to that observed in 11β-HSD1KO mice. Critically, in contrast to 11β-HSD1KO mice, DKO mice phenocopy the salient features of the H6PDHKO, displaying reduced body mass, muscle atrophy, and vacuolation of type II fiber-rich muscle, fasting hypoglycemia, increased muscle glycogen deposition, and elevated expression of UPR genes. We propose that muscle G6P metabolism through H6PDH may be as important as changes in the redox environment when considering the mechanism underlying the activation of the UPR and the ensuing myopathy in H6PDHKO and DKO mice. These data are consistent with an 11β-HSD1-independent function for H6PDH in which sarcoplasmic reticulum G6P metabolism and nicotinamide adenine dinucleotide phosphate-(oxidized)\\/nicotinamide adenine dinucleotide phosphate (reduced) redox status are important for maintaining muscle homeostasis.

  6. The innate immune DNA sensor cGAS produces a noncanonical cyclic dinucleotide that activates human STING.

    Science.gov (United States)

    Diner, Elie J; Burdette, Dara L; Wilson, Stephen C; Monroe, Kathryn M; Kellenberger, Colleen A; Hyodo, Mamoru; Hayakawa, Yoshihiro; Hammond, Ming C; Vance, Russell E

    2013-05-30

    The presence of foreign DNA in the cytosol of mammalian cells elicits a potent antiviral interferon response. Recently, cytosolic DNA was proposed to induce the synthesis of cyclic GMP-AMP (cGAMP) upon binding to an enzyme called cGAMP synthase (cGAS). cGAMP activates an interferon response by binding to a downstream receptor called STING. Here, we identify natural variants of human STING (hSTING) that are poorly responsive to cGAMP yet, unexpectedly, are normally responsive to DNA and cGAS signaling. We explain this paradox by demonstrating that the cGAS product is actually a noncanonical cyclic dinucleotide, cyclic [G(2'-5')pA(3'-5')p], which contains a single 2'-5' phosphodiester bond. Cyclic [G(2'-5')pA(3'-5')p] potently activates diverse hSTING receptors and, therefore, may be a useful adjuvant or immunotherapeutic. Our results indicate that hSTING variants have evolved to distinguish conventional (3'-5') cyclic dinucleotides, known to be produced mainly by bacteria, from the noncanonical cyclic dinucleotide produced by mammalian cGAS. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  7. The Innate Immune DNA Sensor cGAS Produces a Noncanonical Cyclic Dinucleotide that Activates Human STING

    Directory of Open Access Journals (Sweden)

    Elie J. Diner

    2013-05-01

    Full Text Available The presence of foreign DNA in the cytosol of mammalian cells elicits a potent antiviral interferon response. Recently, cytosolic DNA was proposed to induce the synthesis of cyclic GMP-AMP (cGAMP upon binding to an enzyme called cGAMP synthase (cGAS. cGAMP activates an interferon response by binding to a downstream receptor called STING. Here, we identify natural variants of human STING (hSTING that are poorly responsive to cGAMP yet, unexpectedly, are normally responsive to DNA and cGAS signaling. We explain this paradox by demonstrating that the cGAS product is actually a noncanonical cyclic dinucleotide, cyclic [G(2′-5′pA(3′-5′p], which contains a single 2′-5′ phosphodiester bond. Cyclic [G(2′-5′pA(3′-5′p] potently activates diverse hSTING receptors and, therefore, may be a useful adjuvant or immunotherapeutic. Our results indicate that hSTING variants have evolved to distinguish conventional (3′-5′ cyclic dinucleotides, known to be produced mainly by bacteria, from the noncanonical cyclic dinucleotide produced by mammalian cGAS.

  8. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  9. Detection of Mycosphaerella graminicola in Wheat Leaves by a Microsatellite Dinucleotide Specific-Primer

    Directory of Open Access Journals (Sweden)

    Joseph-Alexander Verreet

    2011-01-01

    Full Text Available Early detection of infection is very important for efficient management of Mycosphaerella graminicola leaf blotch. To monitor and quantify the occurrence of this fungus during the growing season, a diagnostic method based on real-time PCR was developed. Standard and real-time PCR assays were developed using SYBR Green chemistry to quantify M. graminicola in vitro or in wheat samples. Microsatellite dinucleotide specific-primers were designed based on microsatellite repeats of sequences present in the genome of M. graminicola. Specificity was checked by analyzing DNA of 55 M. graminicola isolates obtained from different geographical origins. The method appears to be highly specific for detecting M. graminicola; no fluorescent signals were observed from 14 other closely related taxa. Primer (CT 7 G amplified a specific amplicon of 570 bp from all M. graminicola isolates. The primers did not amplify DNA extracted from 14 other fungal species. The approximate melting temperature (Tm of the (CT 7 G primer was 84.2 °C. The detection limit of the real-time PCR assay with the primer sets (CT 7 G is 10 fg/25 µL, as compared to 10 pg/25 µL using conventional PCR technology. From symptomless leaves, a PCR fragment could be generated two days after inoculation. Both conventional and real-time PCR could successfully detect the fungus from artificially inoculated wheat leaves. However, real-time PCR appeared much more sensitive than conventional PCR. The developed quantitative real-time PCR method proved to be rapid, sensitive, specific, cost-effective and reliable for the identification and quantification of M. graminicola in wheat.

  10. A new sensitive 32P-postlabeling assay based on the specific enzymatic conversion of bulky DNA lesions to radiolabeled dinucleotides and nucleoside 5'-monophosphates

    International Nuclear Information System (INIS)

    Randerath, Kurt; Randerath, Erika; Danna, T.F.; Van Golen, K.L.; Putman, K.L.

    1989-01-01

    A new sensitive 32 P-postlabelling assay for DNA adducts has been developed. When DNA containing bulky adducts, X 1 , X 2 , .....X n , is digested with nuclease P1 at pH 5, normal nucleotides are released as 5'-monophosphates, pN, while adducts are excised as 5'-phosphorylated dinucleotides, pX i pN, because inter-nucleotide linkages on the 3' side of X resist attack by nuclease P1. Addition of prostatic acid phosphatase to such a digest results in 5'-dephosphorylation of the nucleotides to normal nucleosides, N, and adducted dinucleotides, X i pN, carrying a 5'-terminal free hydroxyl group. The dinucleotides but not nucleosides are converted to 5'- 32 P-labeled dinucleotides,[ 32 P]pX i pN, by T4 polynucleotide kinase-catalyzed [ 32 P]posphate transfer from [γ- 32 P]ATP. Upon mapping on polyethyleneimine-cellulose anion-exchange TLC, the labeled dinucleotide adducts produce characteristic autoradiographic fingerprints. Alternatively, they are further digested with snake venom phosphodiesterase to yield 5'-monophosphates, [ 32 P]pX i and pN. TLC profiles of the monophosphate adducts are distinct from those of the dinucleotides. These reactions provide the basis of the new 32 P-postlabeling scheme, which is compared in this paper with a previously reported protocol yielding adducts in the form of 5'- 32 P-labeled 3',5'-bisphosphates, [ 32 P]pX i p. (author)

  11. Dinucleotide repeat polymorphism in Fms-like tyrosine kinase-1 (Flt-1 gene is not associated with preeclampsia

    Directory of Open Access Journals (Sweden)

    Park So-Yeon

    2008-07-01

    Full Text Available Abstract Background Preeclampsia is a major cause of maternal and perinatal mortality and morbidity. The etiology of preeclampsia remains unclear. Recently, it was shown that misregulation of fms-like tyrosine kinase-1 (Flt-1 in the peripheral blood mononuclear cells of pregnant women results in over-expression of the soluble splice variant of Flt-1, sFlt-1, producing an additional (extra-placental source of sFlt-1 that can contribute to the etiology of preeclampsia. The aim of this study was to investigate the relationship between preeclampsia and a dinucleotide (threonine-glycine; TGn repeat polymorphism in the 3' non-coding region of the Flt-1 gene. Methods The number of the d(TGn repeats was analyzed in 170 patients with preeclampsia and in 202 normotensive pregnancies. The region containing the dinucleotide repeat polymorphism of the Flt-1 gene was amplified by polymerase chain reaction (PCR from the DNA samples and was analyzed by direct PCR sequencing. Results We found 10 alleles of the dinucleotide repeat polymorphism and designated these as allele*12 (A1 through allele*23 (A12 according to the number of the TG repeats, from 12 to 23. The frequency of the 14-repeat allele (A3 was most abundant (63.82% in preeclampsia and 69.06% in controls, followed by the 21-repeat allele (A10; 28.53% in preeclampsia and 23.76% in controls. There was no significant difference in the allele frequency between patients with preeclampsia and normal controls. The most common genotype in preeclamptic and normotensive pregnancies was heterozygous (TG14/(TG21 (41.76% and homozygous (TG14/(TG14 (45.05%, respectively. However, the genotype frequencies were not significantly different between preeclamptic patients and controls. Conclusion This is the first study to characterize the dinucleotide repeat polymorphism of the Flt-1 gene in patients with preeclampsia. We found no differences in the allele or genotype frequencies between patients with preeclampsia and

  12. Study on preventive effects of i.v. administration of flavin adenine dinucleotide (FAD) before irradiation on radiation stomatitis

    International Nuclear Information System (INIS)

    Nagai, Masao; Houzawa, Jiro; Hakamada, Masaru

    1984-01-01

    In order to compare the preventive effect on radiation stomatitis, flavin adenine dinucleotide (FAD) or vitamin C was administered intravenously until the blood level reached the maximum at the time of irradiation. Thirtyfive patients with cranial or cervical tumors were allocated into the group with FAD (15), the group with vitamin C (10), and the group with irradiation alone (10). The incidence of stomititis was significantly lower and the number of patients in whom the drug was withdrawn due to stomatitis was extremely smaller in the group with FAD than in the other groups. FAD administered before irradiation was considered very useful in preventing radiation stomatitis. (Namekawa, K.)

  13. Understanding the sequence preference of recurrent RNA building blocks using quantum chemistry: The intrastrand RNA dinucleotide platform

    Czech Academy of Sciences Publication Activity Database

    Mládek, Arnošt; Šponer, Judit E.; Kulhánek, P.; Lu, X.-J.; Olson, W.K.; Šponer, Jiří

    2012-01-01

    Roč. 8, č. 1 (2012), s. 335-347 ISSN 1549-9618 R&D Projects: GA AV ČR(CZ) IAA400040802; GA ČR(CZ) GAP208/10/2302; GA ČR(CZ) GA203/09/1476; GA ČR(CZ) GAP208/11/1822; GA ČR(CZ) GD203/09/H046 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : RNA dinucleotide platform * quantum-chemical calculation Subject RIV: BO - Biophysics Impact factor: 5.389, year: 2012

  14. Synthesis, conformational analysis, and biological activity of new analogues of thiazole-4-carboxamide adenine dinucleotide (TAD) as IMP dehydrogenase inhibitors.

    Science.gov (United States)

    Franchetti, Palmarisa; Cappellacci, Loredana; Pasqualini, Michela; Petrelli, Riccardo; Jayaprakasan, Vetrichelvan; Jayaram, Hiremagalur N; Boyd, Donald B; Jain, Manojkumar D; Grifantini, Mario

    2005-03-15

    Thiazole-4-carboxamide adenine dinucleotide (TAD) analogues T-2'-MeAD (1) and T-3'-MeAD (2) containing, respectively, a methyl group at the ribose 2'-C-, and 3'-C-position of the adenosine moiety, were prepared as potential selective human inosine monophosphate dehydrogenase (IMPDH) type II inhibitors. The synthesis of heterodinucleotides was carried out by CDI-catalyzed coupling reaction of unprotected 2'-C-methyl- or 3'-C-methyl-adenosine 5'-monophosphate with 2',3'-O-isopropylidene-tiazofurin 5'-monophosphate, and then deisopropylidenation. Biological evaluation of dinucleotides 1 and 2 as inhibitors of recombinant human IMPDH type I and type II resulted in a good activity. Inhibition of both isoenzymes by T-2'-MeAD and T-3'-MeAD was noncompetitive with respect to NAD substrate. Binding of T-3'-MeAD was comparable to that of parent compound TAD, while T-2'-MeAD proved to be a weaker inhibitor. However, no significant difference was found in inhibition of the IMPDH isoenzymes. T-2'-MeAD and T-3'-MeAD were found to inhibit the growth of K562 cells (IC(50) 30.7 and 65.0muM, respectively).

  15. High-resolution crystal structures of the photoreceptor glyceraldehyde 3-phosphate dehydrogenase (GAPDH) with three and four-bound NAD molecules

    Science.gov (United States)

    Baker, Bo Y; Shi, Wuxian; Wang, Benlian; Palczewski, Krzysztof

    2014-01-01

    Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) catalyzes the oxidative phosphorylation of d-glyceraldehyde 3-phosphate (G3P) into 1,3-diphosphoglycerate (BGP) in the presence of the NAD cofactor. GAPDH is an important drug target because of its central role in glycolysis, and nonglycolytic processes such as nuclear RNA transport, DNA replication/repair, membrane fusion and cellular apoptosis. Recent studies found that GAPDH participates in the development of diabetic retinopathy and its progression after the cessation of hyperglycemia. Here, we report two structures for native bovine photoreceptor GAPDH as a homotetramer with differing occupancy by NAD, bGAPDH(NAD)4, and bGAPDH(NAD)3. The bGAPDH(NAD)4 was solved at 1.52 Å, the highest resolution for GAPDH. Structural comparison of the bGAPDH(NAD)4 and bGAPDH(NAD)3 models revealed novel details of conformational changes induced by cofactor binding, including a loop region (residues 54–56). Structure analysis of bGAPDH confirmed the importance of Phe34 in NAD binding, and demonstrated that Phe34 was stabilized in the presence of NAD but displayed greater mobility in its absence. The oxidative state of the active site Cys149 residue is regulated by NAD binding, because this residue was found oxidized in the absence of dinucleotide. The distance between Cys149 and His176 decreased upon NAD binding and Cys149 remained in a reduced state when NAD was bound. These findings provide an important structural step for understanding the mechanism of GAPDH activity in vision and its pathological role in retinopathies. PMID:25176140

  16. Phosphate control in dialysis

    Directory of Open Access Journals (Sweden)

    Cupisti A

    2013-10-01

    Full Text Available Adamasco Cupisti,1 Maurizio Gallieni,2 Maria Antonietta Rizzo,2 Stefania Caria,3 Mario Meola,4 Piergiorgio Bolasco31Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy; 2Nephrology and Dialysis Unit, San Carlo Borromeo Hospital, Milan, Italy; 3Territorial Department of Nephrology and Dialysis, ASL Cagliari, Italy; 4Sant'Anna School of Advanced Studies, University of Pisa, Pisa, ItalyAbstract: Prevention and correction of hyperphosphatemia is a major goal of chronic kidney disease–mineral and bone disorder (CKD–MBD management, achievable through avoidance of a positive phosphate balance. To this aim, optimal dialysis removal, careful use of phosphate binders, and dietary phosphate control are needed to optimize the control of phosphate balance in well-nourished patients on a standard three-times-a-week hemodialysis schedule. Using a mixed diffusive–convective hemodialysis tecniques, and increasing the number and/or the duration of dialysis tecniques are all measures able to enhance phosphorus (P mass removal through dialysis. However, dialytic removal does not equal the high P intake linked to the high dietary protein requirement of dialysis patients; hence, the use of intestinal P binders is mandatory to reduce P net intestinal absorption. Unfortunately, even a large dose of P binders is able to bind approximately 200–300 mg of P on a daily basis, so it is evident that their efficacy is limited in the case of an uncontrolled dietary P load. Hence, limitation of dietary P intake is needed to reach the goal of neutral phosphate balance in dialysis, coupled to an adequate protein intake. To this aim, patients should be informed and educated to avoid foods that are naturally rich in phosphate and also processed food with P-containing preservatives. In addition, patients should preferentially choose food with a low P-to-protein ratio. For example, patients could choose egg white or protein from a vegetable source

  17. Uranium production from phosphates

    International Nuclear Information System (INIS)

    Ketzinel, Z.; Folkman, Y.

    1979-05-01

    According to estimates of the world's uranium consumption, exploitation of most rich sources is expected by the 1980's. Forecasts show that the rate of uranium consumption will increase towards the end of the century. It is therefore desirable to exploit poor sources not yet in use. In the near future, the most reasonable source for developing uranium is phosphate rock. Uranium reserves in phosphates are estimated at a few million tons. Production of uranium from phosphates is as a by-product of phosphate rock processing and phosphoric acid production; it will then be possible to save the costs incurred in crushing and dissolving the rock when calculating uranium production costs. Estimates show that the U.S. wastes about 3,000 tons of uranium per annum in phosphoric acid based fertilisers. Studies have also been carried out in France, Yugoslavia and India. In Israel, during the 1950's, a small plant was operated in Haifa by 'Chemical and Phosphates'. Uranium processes have also been developed by linking with the extraction processes at Arad. Currently there is almost no activity on this subject because there are no large phosphoric acid plants which would enable production to take place on a reasonable scale. Discussions are taking place about the installation of a plant for phosphoric acid production utilising the 'wet process', producing 200 to 250,000 tons P 2 O 5 per annum. It is necessary to combine these facilities with uranium production plant. (author)

  18. Isolation and characterisation of a dinucleotide microsatellite set for a parentage and biodiversity study in domestic guinea pig (Cavia porcellus

    Directory of Open Access Journals (Sweden)

    Diana Aviles

    2015-10-01

    Full Text Available The domestic guinea pig is a valuable genetic resource because it is part of local folklore and food tradition in many South American countries. The economic importance of the guinea pig is due to its high feed efficiency and the quality of animal protein produced. For these reasons, our study is aimed to design a complete dinucleotide microsatellite marker set following international recommendation to assess the genetic diversity and genealogy management of guinea pigs. We selected a total of 20 microsatellites, looking for laboratory efficiency and good statistical parameters. The set was tested in 100 unrelated individuals of guinea pigs from Ecuador, Peru, Colombia, Bolivia and Spain. Our results show a high degree of polymorphisms with a total of 216 alleles and a mean number of 10.80±3.49 for markers with a combined exclusion probability of 0.99.

  19. Recovering uranium from phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Bergeret, M [Compagnie de Produits Chimiques et Electrometallurgiques Pechiney-Ugine Kuhlmann, 75 - Paris (France)

    1981-06-01

    Processes for the recovery of the uranium contained in phosphates have today become competitive with traditional methods of working uranium sources. These new possibilities will make it possible to meet more rapidly any increases in the demand for uranium: it takes ten years to start working a new uranium deposit, but only two years to build a recovery plant.

  20. Erythrocyte glucose-6-phosphate dehydrogenase from Brazilian opossum Didelphis marsupialis

    Directory of Open Access Journals (Sweden)

    Barretto O.C. de O.

    2006-01-01

    Full Text Available In a comparative study of erythrocyte metabolism of vertebrates, the specific activity of glucose-6-phosphate dehydrogenase (G6PD of the Brazilian opossum Didelphis marsupialis in a hemolysate was shown to be high, 207 ± 38 IU g-1 Hb-1 min-1 at 37ºC, compared to the human erythrocyte activity of 12 ± 2 IU g-1 Hb-1 min-1 at 37ºC. The apparent high specific activity of the mixture led us to investigate the physicochemical properties of the opossum enzyme. We report that reduced glutathione (GSH in the erythrocytes was only 50% higher than in human erythrocytes, a value lower than expected from the high G6PD activity since GSH is maintained in a reduced state by G6PD activity. The molecular mass, determined by G-200 Sephadex column chromatography at pH 8.0, was 265 kDa, which is essentially the same as that of human G6PD (260 kDa. The Michaelis-Menten constants (Km: 55 µM for glucose-6-phosphate and nicotinamide adenine dinucleotide phosphate (Km: 3.3 µM were similar to those of the human enzyme (Km: 50-70 and Km: 2.9-4.4, respectively. A 450-fold purification of the opossum enzyme was achieved and the specific activity of the purified enzyme, 90 IU/mg protein, was actually lower than the 150 IU/mg protein observed for human G6PD. We conclude that G6PD after purification from the hemolysate of D. marsupialis does not have a high specific activity. Thus, it is quite probable that the red cell hyperactivity reported may be explained by increased synthesis of G6PD molecules per unit of hemoglobin or to reduced inactivation in the RBC hemolysate.

  1. Glucose-6-phosphate dehydrogenase protects Escherichia coli from tellurite-mediated oxidative stress.

    Directory of Open Access Journals (Sweden)

    Juan M Sandoval

    Full Text Available The tellurium oxyanion tellurite induces oxidative stress in most microorganisms. In Escherichia coli, tellurite exposure results in high levels of oxidized proteins and membrane lipid peroxides, inactivation of oxidation-sensitive enzymes and reduced glutathione content. In this work, we show that tellurite-exposed E. coli exhibits transcriptional activation of the zwf gene, encoding glucose 6-phosphate dehydrogenase (G6PDH, which in turn results in augmented synthesis of reduced nicotinamide adenine dinucleotide phosphate (NADPH. Increased zwf transcription under tellurite stress results mainly from reactive oxygen species (ROS generation and not from a depletion of cellular glutathione. In addition, the observed increase of G6PDH activity was paralleled by accumulation of glucose-6-phosphate (G6P, suggesting a metabolic flux shift toward the pentose phosphate shunt. Upon zwf overexpression, bacterial cells also show increased levels of antioxidant molecules (NADPH, GSH, better-protected oxidation-sensitive enzymes and decreased amounts of oxidized proteins and membrane lipids. These results suggest that by increasing NADPH content, G6PDH plays an important role in E. coli survival under tellurite stress.

  2. A comparative study of the DG-OMEGA (DG Omega), DGII, and GAT method for the structure elucidation of a methylene-acetal linked thymine dinucleotide

    NARCIS (Netherlands)

    van Kampen, A. H. C.; Beckers, M. L. M.; Buydens, L. M. C.

    1997-01-01

    This research continues the investigation of the properties of the recently developed structure elucidation method DG-OMEGA (DG Omega). Towards this end it was applied for the structure determination of a methylene-acetal linked thymine dinucleotide. The performance of DG Omega was compared to the

  3. Development of a simple and efficient method for assaying cytidine monophosphate sialic acid synthetase activity using an enzymatic reduced nicotinamide adenine dinucleotide/oxidized nicotinamide adenine dinucleotide converting system.

    Science.gov (United States)

    Fujita, Akiko; Sato, Chihiro; Münster-Kühnel, Anja-K; Gerardy-Schahn, Rita; Kitajima, Ken

    2005-02-01

    A new reliable method to assay the activity of cytidine monophosphate sialic acid (CMP-Sia) synthetase (CSS) has been developed. The activation of sialic acids (Sia) to CMP-Sia is a prerequisite for the de novo synthesis of sialoglycoconjugates. In vertebrates, CSS has been cloned from human, mouse, and rainbow trout, and the crystal structure has been resolved for the mouse enzyme. The mouse and rainbow trout enzyme have been compared with respect to substrate specificity, demonstrating that the mouse enzyme exhibits a pronounced specificity for N-acetylneuraminic acid (Neu5Ac), while the rainbow trout CSS is equally active with either of three Sia species, Neu5Ac, N-glycolylneuraminic acid (Neu5Gc), and deaminoneuraminic acid (KDN). However, molecular details that explain the pronounced substrate specificities are unknown. Understanding the catalytic mechanisms of these enzymes is of major importance, since CSSs play crucial roles in cellular sialylation patterns and thus are potential drug targets in a number of pathophysiological situations. The availability of the cDNAs and the obtained structural data enable rational approaches; however, these efforts are limited by the lack of a reliable high-throughput assay system. Here we describe a new assay system that allows product quantification in a reduced nicotinamide adenine dinucleotide (NADH)-dependent color reaction. The activation reaction catalyzed by CSS, CTP+Sia-->CMP-Sia+pyrophosphate, was evaluated by a consumption of Sia, which corresponds to that of NADH on the following two successive reactions: (i) Sia-->pyruvate+ManNAc (or Man), catalyzed by a sialic acid lyase (SAL), and (ii) pyruvate+NADH-->lactate+oxidized nicotinamide adenine dinucleotide (NAD+), catalyzed by a lactate dehydrogenase (LDH). Consumption of NADH can be photometrically monitored on a microtiter plate reader for a number of test samples at the same time. Furthermore, based on the quantification of CSS used in the SAL/LDH assay

  4. Renal phosphate handling: Physiology

    Directory of Open Access Journals (Sweden)

    Narayan Prasad

    2013-01-01

    Full Text Available Phosphorus is a common anion. It plays an important role in energy generation. Renal phosphate handling is regulated by three organs parathyroid, kidney and bone through feedback loops. These counter regulatory loops also regulate intestinal absorption and thus maintain serum phosphorus concentration in physiologic range. The parathyroid hormone, vitamin D, Fibrogenic growth factor 23 (FGF23 and klotho coreceptor are the key regulators of phosphorus balance in body.

  5. Triphenyl phosphate allergy from spectacle frames

    DEFF Research Database (Denmark)

    Carlsen, L; Andersen, K E; Egsgaard, Helge

    1986-01-01

    A case of triphenyl phosphate allergy from spectacle frames is reported. Patch tests with analytical grade triphenyl phosphate, tri-m-cresyl phosphate, and tri-p-cresyl phosphate in the concentrations 5%, 0.5% and 0.05% pet. showed positive reactions to 0.05% triphenyl phosphate and 0.5% tri......-m-cresyl phosphate, but no reaction to tri-p-cresyl phosphate. Gas chromatography of the tricresyl phosphate 5% pet. patch test material supplied from Trolab showed that it contained a mixture of a wide range of triaryl phosphates, including 0.08% triphenyl phosphate which is above the threshold for detecting...

  6. Meal phosphate variability does not support fixed dose phosphate binder schedules for patients treated with peritoneal dialysis: a prospective cohort study.

    Science.gov (United States)

    Leung, Simon; McCormick, Brendan; Wagner, Jessica; Biyani, Mohan; Lavoie, Susan; Imtiaz, Rameez; Zimmerman, Deborah

    2015-12-09

    Removal of phosphate by peritoneal dialysis is insufficient to maintain normal serum phosphate levels such that most patients must take phosphate binders with their meals. However, phosphate 'counting' is complicated and many patients are simply prescribed a specific dose of phosphate binders with each meal. Therefore, our primary objective was to assess the variability in meal phosphate content to determine the appropriateness of this approach. In this prospective cohort study, adult patients with ESRD treated with peritoneal dialysis and prescribed phosphate binder therapy were eligible to participate. Participants were excluded from the study if they were unable to give consent, had hypercalcemia, were visually or hearing impaired or were expected to receive a renal transplant during the time of the study. After providing informed consent, patients kept a 3-day diet diary that included all foods and beverages consumed in addition to portion sizes. At the same time, patients documented the amount of phosphate binders taken with each meal. The phosphate content of the each meal was estimated using ESHA Food Processor SQL Software by a registered dietitian. Meal phosphate and binder variability were estimated by the Intra Class Correlation Coefficient (ICC) where 0 indicates maximal variability and 1 indicates no variability. Seventy-eight patients consented to participate in the study; 18 did not complete the study protocol. The patients were 60 (± 17) years, predominately male (38/60) and Caucasian (51/60). Diabetic nephropathy was the most common cause of end stage kidney disease. The daily phosphate intake including snacks ranged from 959 ± 249 to 1144 ± 362 mg. The phosphate ICC by meal: breakfast 0.63, lunch 0.16; supper 0.27. The phosphate binder ICC by meal: breakfast 0.68, lunch 0.73, supper 0.67. The standard prescription of a set number of phosphate binders with each meal is not supported by the data; patients do not appear to be adjusting their

  7. Integrated assessment of the phosphate industry

    International Nuclear Information System (INIS)

    Ryan, M.T.; Cotter, S.J.

    1980-05-01

    The phosphate industry in the United States includes three major activities, namely, mining and milling of phosphate rock, phosphate product manufacture, and phosphate product use. Phosphatic materials contain uranium, thorium, and their decay products in greater than background amounts. This assessment of the radiological impacts associated with the redistribution of radioactive components of phosphate materials may provide insight into the effects of uranium extraction from phosphate materials for use in the nuclear fuel cycle

  8. Blue light induced reactive oxygen species from flavin mononucleotide and flavin adenine dinucleotide on lethality of HeLa cells.

    Science.gov (United States)

    Yang, Ming-Yeh; Chang, Chih-Jui; Chen, Liang-Yü

    2017-08-01

    Photodynamic therapy (PDT) is a safe and non-invasive treatment for cancers and microbial infections. Various photosensitizers and light sources have been developed for clinical cancer therapies. Flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) are the cofactor of enzymes and are used as photosensitizers in this study. Targeting hypoxia and light-triggering reactive oxygen species (ROS) are experimental strategies for poisoning tumor cells in vitro. HeLa cells are committed to apoptosis when treated with FMN or FAD and exposed to visible blue light (the maximum emitted wavelength of blue light is 462nm). Under blue light irradiation at 3.744J/cm 2 (=0.52mW/cm 2 irradiated for 2h), the minimal lethal dose is 3.125μM and the median lethal doses (LD 50 ) for FMN and FAD are 6.5μM and 7.2μM, respectively. Individual exposure to visible blue light irradiation or riboflavin photosensitizers does not produce cytotoxicity and no side effects are observed in this study. The western blotting results also show that an intrinsic apoptosis pathway is activated by the ROS during photolysis of riboflavin analogues. Blue light triggers the cytotoxicity of riboflavins on HeLa cells in vitro. Based on these results, this is a feasible and efficient of PDT with an intrinsic photosensitizer for cancer research. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. The conserved baculovirus protein p33 (Ac92) is a flavin adenine dinucleotide-linked sulfhydryl oxidase

    International Nuclear Information System (INIS)

    Long, C.M.; Rohrmann, G.F.; Merrill, G.F.

    2009-01-01

    Open reading frame 92 of the Autographa californica baculovirus (Ac92) is one of about 30 core genes present in all sequenced baculovirus genomes. Computer analyses predicted that the Ac92 encoded protein (called p33) and several of its baculovirus orthologs were related to a family of flavin adenine dinucleotide (FAD)-linked sulfhydryl oxidases. Alignment of these proteins indicated that, although they were highly diverse, a number of amino acids in common with the Erv1p/Alrp family of sulfhydryl oxidases are present. Some of these conserved amino acids are predicted to stack against the isoalloxazine and adenine components of FAD, whereas others are involved in electron transfer. To investigate this relationship, Ac92 was expressed in bacteria as a His-tagged fusion protein, purified, and characterized both spectrophotometrically and for its enzymatic activity. The purified protein was found to have the color (yellow) and absorption spectrum consistent with it being a FAD-containing protein. Furthermore, it was demonstrated to have sulfhydryl oxidase activity using dithiothreitol and thioredoxin as substrates.

  10. Kynureninase-type enzymes and the evolution of the aerobic tryptophan-to-nicotinamide adenine dinucleotide pathway

    Energy Technology Data Exchange (ETDEWEB)

    Gaertner, F.H.; Shetty, A.S.

    1977-01-01

    Kynureninase-type (L-kynurenine hydrolase, EC 3.7.1.3) activity has been found to be present in the livers of fish, amphibia, reptiles, and birds. In addition to past information concerning this enzyme activity in mammalian liver, it is now clear that all the major classes of vertebrates carry a highly specialized kynureninase-type enzyme, which we have termed a hydroxykynureninase. To compare the reactivities of these enzymes with L-kynurenine and L-3-hydroxykynurenine, ratios of tau values (K/sub m//V) were used. Based on this comparison, the bacterium Pseudomonas fluorescens carries the most efficient kynureninase, whereas the amphibian Xenopus laevis has the most efficient hydroxykynurenase. In these two cases, the ratio of tau values differs by a factor of 38,000. It is hypothesized that the tryptophan-to-nicotinamide adenine dinucleotide biosynthetic pathway evolved from a catabolic system of enzymes, and that the differences observed in the kynureninase-type enzymes between lower and higher organisms reflect the specialization of the function of these enzymes from a strictly catabolic role to an anabolic one during the course of evolution.

  11. Mitochondrial nicotinamide adenine dinucleotide reduced (NADH) oxidation links the tricarboxylic acid (TCA) cycle with methionine metabolism and nuclear DNA methylation.

    Science.gov (United States)

    Lozoya, Oswaldo A; Martinez-Reyes, Inmaculada; Wang, Tianyuan; Grenet, Dagoberto; Bushel, Pierre; Li, Jianying; Chandel, Navdeep; Woychik, Richard P; Santos, Janine H

    2018-04-18

    Mitochondrial function affects many aspects of cellular physiology, and, most recently, its role in epigenetics has been reported. Mechanistically, how mitochondrial function alters DNA methylation patterns in the nucleus remains ill defined. Using a cell culture model of induced mitochondrial DNA (mtDNA) depletion, in this study we show that progressive mitochondrial dysfunction leads to an early transcriptional and metabolic program centered on the metabolism of various amino acids, including those involved in the methionine cycle. We find that this program also increases DNA methylation, which occurs primarily in the genes that are differentially expressed. Maintenance of mitochondrial nicotinamide adenine dinucleotide reduced (NADH) oxidation in the context of mtDNA loss rescues methionine salvage and polyamine synthesis and prevents changes in DNA methylation and gene expression but does not affect serine/folate metabolism or transsulfuration. This work provides a novel mechanistic link between mitochondrial function and epigenetic regulation of gene expression that involves polyamine and methionine metabolism responding to changes in the tricarboxylic acid (TCA) cycle. Given the implications of these findings, future studies across different physiological contexts and in vivo are warranted.

  12. Electron-transfer studies with a new flavin adenine dinucleotide dependent glucose dehydrogenase and osmium polymers of different redox potentials.

    Science.gov (United States)

    Zafar, Muhammad Nadeem; Wang, Xiaoju; Sygmund, Christoph; Ludwig, Roland; Leech, Dónal; Gorton, Lo

    2012-01-03

    A new extracellular flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase from Glomerella cingulata (GcGDH) was electrochemically studied as a recognition element in glucose biosensors. The redox enzyme was recombinantly produced in Pichia pastoris and homogeneously purified, and its glucose-oxidizing properties on spectrographic graphite electrodes were investigated. Six different Os polymers, the redox potentials of which ranged in a broad potential window between +15 and +489 mV versus the normal hydrogen electrode (NHE), were used to immobilize and "wire" GcGDH to the spectrographic graphite electrode's surface. The GcGDH/Os polymer modified electrodes were evaluated by chronoamperometry using flow injection analysis. The current response was investigated using a stepwisely increased applied potential. It was observed that the ratio of GcGDH/Os polymer and the overall loading of the enzyme electrode significantly affect the performance of the enzyme electrode for glucose oxidation. The best-suited Os polymer [Os(4,4'-dimethyl-2,2'-bipyridine)(2)(PVI)Cl](+) had a potential of +309 mV versus NHE, and the optimum GcGDH/Os polymer ratio was 1:2 yielding a maximum current density of 493 μA·cm(-2) at a 30 mM glucose concentration. © 2011 American Chemical Society

  13. Hypermutability of CpG dinucleotides in the propeptide-encoding sequence of the human albumin gene

    International Nuclear Information System (INIS)

    Brennan, S.O.; Peach, R.; Myles, T.; George, P.; Arai, Kunio; Madison, J.; Watkins, S.; Putnam, F.W.; Laurell, C.B.; Galliano, M.

    1990-01-01

    An electrophoretically slow albumin variant was detected with a phenotype frequency of about 1:1,000 in Sweden and was also found in a family of Scottish descent from Kaikoura, New Zealand, and in five families in Tradate, Italy. Structural study established that the major variant component was arginyl-albumin, in which arginine at the -1 position of the propeptide is still attached to the processed albumin. A minor component with the amino-terminal sequence of proalbumin was also present as 3-6% of the total albumin. After amplification of the gene segment encoding the prepro sequence of albumin, specific hybridization of DNA to an oligonucleotide probe encoding cysteine at position -2 indicated the mutation of arginine at the -2 position to cysteine (-2 Arg → Cys). This produced the propeptide sequence Arg-Gly-Val-Phe-Cys-Arg. This was confirmed by sequence analysis after pyridylethylation of the cysteine. This mutation produces an alternate signal peptidase cleavage site in the variant proalbumin precursor of arginyl-albumin giving rise to two possible products, arginyl-albumin and the variant proalbumin. Another plasma from Bremen had an alloalbumin with a previously described substitution (1 Asp → Val), which also affects propeptide cleavage. Hypermutability of two CpG dinucleotides in the codons for the diarginyl sequence may account for the frequency of mutations in the propeptide. Mutation at these two sites results in a series of recurrent proalbumin variants that have arisen independently in diverse populations

  14. Amperometric cholesterol biosensor based on in situ reconstituted cholesterol oxidase on an immobilized monolayer of flavin adenine dinucleotide cofactor.

    Science.gov (United States)

    Vidal, Juan-C; Espuelas, Javier; Castillo, Juan-R

    2004-10-01

    A new amperometric biosensor for determining cholesterol based on deflavination of the enzyme cholesterol oxidase (ChOx) and subsequent reconstitution of the apo-protein with a complexed flavin adenine dinucleotide (FAD) monolayer is described. The charge transfer mediator pyrroquinoline quinone (PQQ) was covalently bound to a cystamine self-assembled monolayer (SAM) on an Au electrode. Boronic acid (BA) was then bound to PQQ using the carbodiimide procedure, and the BA ligand was complexed to the FAD molecules on which the apo-ChOx was subsequently reconstituted. The effective release of the FAD from the enzyme and the successful reconstitution were verified using molecular fluorescence and cyclic voltammetry. The optimal orientation of FAD toward the PQQ mediator and the distances between FAD and PQQ and between PQQ and electrode enhance the charge transfer, very high sensitivity (about 2,500 nAmM(-1)cm(-2)) being obtained for cholesterol determination. The biosensor is selective toward electroactive interferents (ascorbic acid and uric acid) and was tested in reference serum samples, demonstrating excellent accuracy (relative errors below 3% in all cases). The biosensor activity can be successfully regenerated in a simple process by successive reconstitution with batches of recently prepared apo-ChOx on the same immobilized Au/SAM-PQQ-BA-FAD monolayer (it was tested five times); the lifetime of the biosensor is about 45-60 days.

  15. Better prospects for phosphate production

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    The extraction of uranium as a by product of phosphate production is discussed. Techniques being commercially developed are described. The trend towards the wet process, in which sulphuric acid is used to dissolve the phosphate, producing phosphoric acid, is also the preferred method for uranium recovery. Recovery from a wet process phosphoric acid stream, integrated with phosphate fertilizer manufacture, is becoming increasingly commercially viable for the production of yellow-cake.

  16. on association of trialkyl phosphates

    International Nuclear Information System (INIS)

    Petkovic, D.M.; Maksimovic, Z.B.

    1976-01-01

    The association constants of tri-n-butyl (TBP), tri-n-propyl (TPP) and triethyl phosphate (TEP) with chloroform, carbon tetrachloride and benzene were determined by dielectric constant, proton magnetic resonance and vapor pressure measurements. Correlation of the trialkyl phosphate-chloroform association constants, using the Hammett equation, showed their increase with the number of carbon atoms in the aliphatic radicals. The change of trialkyl phosphate reactivity with temperature was used to determine the thermodynamic quantities. (author)

  17. Phosphate Recovery From Sewage Sludge Containing Iron Phosphate

    NARCIS (Netherlands)

    Wilfert, P.K.

    2018-01-01

    The scope of this thesis was to lay the basis for a phosphate recovery technology that can be applied on sewage sludge containing iron phosphate. Such a technology should come with minimal changes to the existing sludge treatment configuration while keeping the use of chemicals or energy as small as

  18. 21 CFR 137.175 - Phosphated flour.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Phosphated flour. 137.175 Section 137.175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Related Products § 137.175 Phosphated flour. Phosphated flour, phosphated white flour, and phosphated...

  19. Glucose-6-Phosphate Dehydrogenase: Update and Analysis of New Mutations around the World

    Science.gov (United States)

    Gómez-Manzo, Saúl; Marcial-Quino, Jaime; Vanoye-Carlo, America; Serrano-Posada, Hugo; Ortega-Cuellar, Daniel; González-Valdez, Abigail; Castillo-Rodríguez, Rosa Angélica; Hernández-Ochoa, Beatriz; Sierra-Palacios, Edgar; Rodríguez-Bustamante, Eduardo; Arreguin-Espinosa, Roberto

    2016-01-01

    Glucose-6-phosphate dehydrogenase (G6PD) is a key regulatory enzyme in the pentose phosphate pathway which produces nicotinamide adenine dinucleotide phosphate (NADPH) to maintain an adequate reducing environment in the cells and is especially important in red blood cells (RBC). Given its central role in the regulation of redox state, it is understandable that mutations in the gene encoding G6PD can cause deficiency of the protein activity leading to clinical manifestations such as neonatal jaundice and acute hemolytic anemia. Recently, an extensive review has been published about variants in the g6pd gene; recognizing 186 mutations. In this work, we review the state of the art in G6PD deficiency, describing 217 mutations in the g6pd gene; we also compile information about 31 new mutations, 16 that were not recognized and 15 more that have recently been reported. In order to get a better picture of the effects of new described mutations in g6pd gene, we locate the point mutations in the solved three-dimensional structure of the human G6PD protein. We found that class I mutations have the most deleterious effects on the structure and stability of the protein. PMID:27941691

  20. Ultrafast photo-initiated molecular quantum dynamics in the DNA dinucleotide d(ApG) revealed by broadband transient absorption spectroscopy.

    Science.gov (United States)

    Stuhldreier, Mayra C; Temps, Friedrich

    2013-01-01

    The ultrafast photo-initiated quantum dynamics of the adenine-guanine dinucleotide d(ApG) in aqueous solution (pH 7) has been studied by femtosecond time-resolved spectroscopy after excitation at lambda = 260 nm. The results reveal a hierarchy of processes on time scales from tau 100 ps. Characteristic spectro-temporal signatures are observed indicating the transformation of the molecules in the electronic relaxation from the photo-excited state to a long-lived exciplex. In particular, broadband UV/VIS excited-state absorption (ESA) measurements detected a distinctive absorption by the excited dinucleotide around lambda = 335 nm, approximately 0.5 eV to the blue compared to the maximum of the broad and unstructured ESA spectrum after excitation of an equimolar mixture of the mononucleotides dAMP and dGMP. A similar feature has been identified as signature of the excimer in the dynamics of the adenine dinucleotide d(ApA). The lifetime of the d(ApG) exciplex was found to be tau = 124 +/- 4 ps both from the ESA decay time and from the ground-state recovery time, far longer than the sub-picosecond lifetimes of excited dAMP or dGMP. Fluorescence-time profiles measured by the up-conversion technique indicate that the exciplex state is reached around approximately 6 ps after excitation. Very weak residual fluorescence at longer times red-shifted to the emission from the photo-excited state shows that the exciplex is almost optically dark, but still has enough oscillator strength to give rise to the dual fluorescence of the dinucleotide in the static fluorescence spectrum.

  1. Deficiency of the iron-sulfur clusters of mitochondrial reduced nicotinamide-adenine dinucleotide-ubiquinone oxidoreductase (complex I) in an infant with congenital lactic acidosis.

    OpenAIRE

    Moreadith, R W; Batshaw, M L; Ohnishi, T; Kerr, D; Knox, B; Jackson, D; Hruban, R; Olson, J; Reynafarje, B; Lehninger, A L

    1984-01-01

    We report the case of an infant with hypoglycemia, progressive lactic acidosis, an increased serum lactate/pyruvate ratio, and elevated plasma alanine, who had a moderate to profound decrease in the ability of mitochondria from four organs to oxidize pyruvate, malate plus glutamate, citrate, and other NAD+-linked respiratory substrates. The capacity to oxidize the flavin adenine dinucleotide-linked substrate, succinate, was normal. The most pronounced deficiency was in skeletal muscle, the le...

  2. Radioactivity in the phosphate field: actions undertaken by IMPHOS

    International Nuclear Information System (INIS)

    Mrabet, T.; Kotti, M.M.

    2008-01-01

    In order to prevent a potentially negative impact on the phosphate industry of the European Council Directive 96/29/Euratom, IMPHOS participated in several events where discussions were held on the issue of NORM and the consequences of the application of the Directive for the non-nuclear industries, including all the NORM symposia from September 1997 to May 2004. In addition, IMPHOS has undertaken actions to establish an ad hoc committee with members designated by member companies and to initiate a desktop study conducted by CEPN to review the implications of applying the Directive for the phosphate industry. This study is an important collection of data on radiological protection, including doses expected to be received by exposed individuals and monitoring considerations. The main conclusions of these actions are that the radioactivity in the phosphate industry is relatively insignificant, with the total annual exposure of a phosphate worker being less than three thousandths of the limit recommended by the ICRP. (author)

  3. Ambivalent participation

    DEFF Research Database (Denmark)

    Groes-Green, Christian

    2012-01-01

    Participation in young peoples' sexual cultures in Maputo, Mozambique led to reflections about the field dynamics of power, participation, desire, and discomfort. Structural inequalities of race, gender, and educational status resulted in informants seeing me as a morally righteous person to whom......' continued participation. I show how negotiating the risks of participation may simultaneously satisfy the desire for knowledge and curb erotic desires....

  4. A comparison of genetic map distance and linkage disequilibrium between 15 polymorphic dinucleotide repeat loci in two populations

    Energy Technology Data Exchange (ETDEWEB)

    Urbanek, M.; Goldman, D.; Long, J.C. [Lab. of Neurogenetics, Rockville, MD (United States)

    1994-09-01

    Linkage disequilibrium has recently been used to map the diastrophic dysplasia gene in a Finnish sample. One advantage of this method is that the large pedigrees required by some other methods are unnecessary. Another advantage is that linkage disequilibrium mapping capitalizes on the cumulative history of recombination events, rather than those occurring within the sampled individuals. A potential limitation of linkage disequilibrium mapping is that linkage equilibrium is likely to prevail in all but the most isolated populations, e.g., those which have recently experienced founder effects or severe population bottlenecks. In order to test the method`s generality, we examined patterns of linkage disequilibrium between pairs of loci within a known genetic map. Two populations were analyzed. The first population, Navajo Indians (N=45), is an isolate that experienced a severe bottleneck in the 1860`s. The second population, Maryland Caucasians (N=45), is cosmopolitan. We expected the Navajo sample to display more linkage disequilibrium than the Caucasian sample, and possibly that the Navajo disequilibrium pattern would reflect the genetic map. Linkage disequilibrium coefficients were estimated between pairs of alleles at different loci using maximum likelihood. The genetic isolate structure of Navajo Indians is confirmed by the DNA typings. Heterozygosity is lower than in the Caucasians, and fewer different alleles are observed. However, a relationship between genetic map distance and linkage disequilibrium could be discerned in neither the Navajo nor the Maryland samples. Slightly more linkage disequilibrium was observed in the Navajos, but both data sets were characterized by very low disequilibrium levels. We tentatively conclude that linkage disequilibrium mapping with dinucleotide repeats will only be useful with close linkage between markers and diseases, even in very isolated populations.

  5. Phosphate glasses, containing nitrogen

    International Nuclear Information System (INIS)

    Lisitsyna, E.A.; Khalilev, V.D.; Koryavin, A.A.; Goncharova, L.N.

    1987-01-01

    Possibilities of nitrogen-containing glass synthesis by the introduction into the charge of ammonium salts, as well as aluminium nitride, are studied. Zinc alumoyttrium phosphate glass (mol. %) Zn(PO 3 ) 2 - 4O, Al(PO 3 ) 3 - 3O, Y(PO 3 ) 3 -3O is suggested as a matrix. It is shown that the effect of amide and imide groups on the properties of the glass is less noticeable than the effect of nitride groups. Direct introduction of nitride constituent was realized using AlN, but aluminium introduction was taken into account so that the oxide was subtracted. The attempt to introduce more than 2.5 mass % of nitrogen into initial matrix by aluminium nitride has failed due to repeated restoration of glass with amorphous phosphorus isolation

  6. Electrochemical Reduction of Zinc Phosphate

    International Nuclear Information System (INIS)

    Kim, Chang Hwan; Lee, Jung Hyun; Shin, Woon Sup

    2010-01-01

    We demonstrated first that the electrochemical reduction of zinc phosphate in neutral phosphate buffer is possible and potentially applicable to bio-compatible rechargeable battery. The actual redox component is Zn(s)/Zn phosphate(s) and the future research about the control of crystal formation for the better cyclability is required. In lead-acid battery, the electrochemical redox reaction of Pb (s) /PbSO 4(s) is used by reducing Pb(II) and oxidizing Pb(0) in sulfate rich solution. Since both reduced form and oxidized form are insoluble, they cannot diffuse to the opposite electrodes and react. It is a very common strategy to make a stable battery electrode that a metal element is reduced and oxidized in solution containing an abundance of anion readily precipitating with the metal ion. For the application of this strategy to construction of rechargeable battery using bio-compatible electrode materials and electrolytes, the use of phosphate ion can be considered as anion readily precipitating with metal ions. If phosphate buffer with neutral pH is used as electrolyte, the better bio-compatibility will be achieved than most of rechargeable battery using strong acid, strong base or organic solvent as electrolyte solution. There are many metal ions readily precipitating with phos-phate ion, and zinc is one of them

  7. Hydrogen permeation resistant phosphate coatings

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1979-01-01

    A method for reducing hydrogen diffusion through metal wherein the metal is coated with a phosphate-radical-containing, phosphate-glass-forming material on at least one surface thereof. The coating is then heated to at least 350 0 C to form a phosphate glass. This method is especially applicable to nuclear reactors to minimize tritium diffusion. The coating is preferably formed with a solution of phosphoric acid which may also contain compounds such as MnSO 4 , SiO 2 and Na 2 Cr 2 0 7 . (author)

  8. Hydrogen permeation resistant phosphate coatings

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1979-01-01

    A method for reducing hydrogen diffusion through metal is described. The metal is coated with a phosphate-radical-containing, phosphate-glass-forming material on at least one surface. The coating is then heated to at least 350 0 C to form a phosphate glass. This method is especially applicable to nuclear reactors to minimize tritium diffusion. The coating is preferably formed with a solution of phosphoric acid which may also contain compounds such as MnSO 4 , SiO 2 and Na 2 Cr 2 O 7 . (author)

  9. Unfolding Participation

    DEFF Research Database (Denmark)

    Saad-Sulonen, Joanna; Halskov, Kim; Eriksson, Eva

    2015-01-01

    The aim of the Unfolding Participation workshop is to outline an agenda for the next 10 years of participatory design (PD) and participatory human computer interaction (HCI) research. We will do that through a double strategy: 1) by critically interrogating the concept of participation (unfolding...... the concept itself), while at the same time, 2) reflecting on the way that participation unfolds across different participatory configurations. We invite researchers and practitioners from PD and HCI and fields in which information technology mediated participation is embedded (e.g. in political studies......, urban planning, participatory arts, business, science and technology studies) to bring a plurality of perspectives and expertise related to participation....

  10. Calcium phosphates for biomedical applications

    Directory of Open Access Journals (Sweden)

    Maria Canillas

    2017-05-01

    Full Text Available The history of calcium phosphates in the medicine field starts in 1769 when the first evidence of its existence in the bone tissue is discovered. Since then, the interest for calcium phosphates has increased among the scientific community. Their study has been developed in parallel with new advances in materials sciences, medicine or tissue engineering areas. Bone tissue engineering is the field where calcium phosphates have had a great importance. While the first bioceramics are selected according to bioinert, biocompatibility and mechanical properties with the aim to replace bone tissue damaged, calcium phosphates open the way to the bone tissue regeneration challenge. Nowadays, they are present in the majority of commercial products directed to repair or regenerate damaged bone tissue. Finally, in the last few decades, they have been suggested and studied as drug delivering devices and as vehicles of DNA and RNA for the future generation therapies.

  11. Variability of nitrate and phosphate

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.; Sundar, D.

    Nitrate and phosphate are important elements of the biogeochemical system of an estuary. Observations carried out during the dry season April-May 2002, and March 2003 and wet season September 2002, show temporal and spatial variability of these two...

  12. Preparation of calcium phosphate paste

    International Nuclear Information System (INIS)

    Mohd Reusmaazran Yusof; Norzita Yaacob; Idris Besar; Che Seman Mahmood; Rusnah Mustafa

    2010-01-01

    Calcium phosphate paste were prepared by mixing between calcium sodium potassium phosphate, Ca 2 NaK (PO 4 ) 2 (CSPP) and monocalcium phosphate monohydrate, Ca(H 2 PO 4 ) 2 .H 2 O (MCPM). CSPP were obtained by reaction between calcium hydrogen phosphate (CaHPO 4 ), potassium carbonate (K 2 CO 3 ) and sodium carbonate (Na 2 CO 3 ) in solid state sintering process followed by quenching in air at 1000 degree Celsius. The paste was aging in simulated body fluid (SBF) for 0.5, 1, 3, 6, 12, 24, 48 hrs, 3, 7 and 14 days. The morphological investigation indicated the formation of apatite crystal were first growth after 24 hours. The obvious growth of apatite crystal was shown at 3 days. The obvious growth of apatite crystal was shown in 7 and 14 days indicated the prediction of paste would have rapid reaction with bone after implantation. (author)

  13. Calcium phosphates for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Canillas, M.; Pena, P.; Aza, A.H. de; Rodriguez, M.A.

    2017-07-01

    The history of calcium phosphates in the medicine field starts in 1769 when the first evidence of its existence in the bone tissue is discovered. Since then, the interest for calcium phosphates has increased among the scientific community. Their study has been developed in parallel with new advances in materials sciences, medicine or tissue engineering areas. Bone tissue engineering is the field where calcium phosphates have had a great importance. While the first bioceramics are selected according to bioinert, biocompatibility and mechanical properties with the aim to replace bone tissue damaged, calcium phosphates open the way to the bone tissue regeneration challenge. Nowadays, they are present in the majority of commercial products directed to repair or regenerate damaged bone tissue. Finally, in the last few decades, they have been suggested and studied as drug delivering devices and as vehicles of DNA and RNA for the future generation therapies. (Author)

  14. Phosphate solubilization and multiple plant growth promoting ...

    African Journals Online (AJOL)

    Phosphate solubilizing efficiencies of the strains were analyzed using different insoluble phosphorus sources and the results show that most isolates released a substantial amount of soluble phosphate from tricalcium phosphate, rock phosphate and bone meal. Screening for multiple plant growth promoting attributes ...

  15. Electrical properties of phosphate glasses

    International Nuclear Information System (INIS)

    Mogus-Milankovic, A; Santic, A; Reis, S T; Day, D E

    2009-01-01

    Investigation of the electrical properties of phosphate glasses where transition metal oxide such as iron oxide is the network former and network modifier is presented. Phosphate glasses containing iron are electronically conducting glasses where the polaronic conduction is due to the electron hopping from low to high iron valence state. The identification of structural defects caused by ion/polaron migration, the analysis of dipolar states and electrical conductivity in iron phosphate glasses containing various alkali and mixed alkali ions was performed on the basis of the impedance spectroscopy (IS). The changes in electrical conductivity from as-quenched phosphate glass to fully crystallized glass (glass-ceramics) by IS are analyzed. A change in the characteristic features of IS follows the changes in glass and crystallized glass network. Using IS, the contribution of glass matrix, crystallized grains and grain boundary to the total electrical conductivity for iron phosphate glasses was analyzed. It was shown that decrease in conductivity is caused by discontinuities in the conduction pathways as a result of the disruption of crystalline network where two or more crystalline phases are formed. Also, phosphate-based glasses offer a unique range of biomaterials, as they form direct chemical bonding with hard/soft tissue. The surface charges of bioactive glasses are recognized to be the most important factors in determining biological responses. The improved bioactivity of the bioactive glasses as a result of the effects of the surface charges generated by electrical polarization is discussed.

  16. Authoring Participation

    DEFF Research Database (Denmark)

    Papazu, Irina

    2016-01-01

    participation so central to the Renewable Energy Island project can be better understood as instances of material participation motivated first and foremost by a concern for the future of the island as a 'liveable' community; a community in which jobs and institutions are not constantly threatening to disappear...

  17. Comparative anatomy of the human APRT gene and enzyme: nucleotide sequence divergence and conservation of a nonrandom CpG dinucleotide arrangement

    International Nuclear Information System (INIS)

    Broderick, T.P.; Schaff, D.A.; Bertino, A.M.; Dush, M.K.; Tischfield, J.A.; Stambrook, P.J.

    1987-01-01

    The functional human adenine phosphoribosyltransferase (APRT) gene is <2.6 kilobases in length and contains five exons. The amino acid sequences of APRTs have been highly conserved throughout evolution. The human enzyme is 82%, 90%, and 40% identical to the mouse, hamster, and Escherichia coli enzymes, respectively. The promoter region of the human APRT gene, like that of several other housekeeping genes, lacks TATA and CCAAT boxes but contains five GC boxes that are potential binding sites for the Sp1 transcription factor. The distal three, however, are dispensable for gene expression. Comparison between human and mouse APRT gene nucleotide sequences reveals a high degree of homology within protein coding regions but an absence of significant homology in 5' flanking, 3' untranslated, and intron sequences, except for similarly positioned GC boxes in the promoter region and a 26-base-pair region in intron 3. This 26-base-pair sequence is 92% identical with a similarly positioned sequence in the mouse gene and is also found in intron 3 of the hamster gene, suggesting that its retention may be a consequence of stringent selection. The positions of all introns have been precisely retained in the human and both rodent genes. Retention of an elevated CpG dinucleotide content, despite loss of sequence homology, suggests that there may be selection for CpG dinucleotides in these regions and that their maintenance may be important for APRT gene function

  18. Uranium endowments in phosphate rock

    International Nuclear Information System (INIS)

    Ulrich, Andrea E.; Schnug, Ewald; Prasser, Horst-Michael; Frossard, Emmanuel

    2014-01-01

    This study seeks to identify and specify the components that make up the prospects of U recovery from phosphate rock. A systems approach is taken. The assessment includes i) reviewing past recovery experience and lessons learned; ii) identifying factors that determine recovery; and iii) establishing a contemporary evaluation of U endowments in phosphate rock reserves, as well as the available and recoverable amounts from phosphate rock and phosphoric acid production. We find that in the past, recovery did not fulfill its potential and that the breakup of the Soviet Union worsened then-favorable recovery market conditions in the 1990s. We find that an estimated 5.7 million tU may be recoverable from phosphate rock reserves. In 2010, the recoverable tU from phosphate rock and phosphoric acid production may have been 15,000 tU and 11,000 tU, respectively. This could have filled the world U supply-demand gap for nuclear energy production. The results suggest that the U.S., Morocco, Tunisia, and Russia would be particularly well-suited to recover U, taking infrastructural considerations into account. We demonstrate future research needs, as well as sustainability orientations. We conclude that in order to promote investment and production, it seems necessary to establish long-term contracts at guaranteed prices, ensuring profitability for phosphoric acid producers. - Highlights: • We identify components that underlie the recovery of uranium from phosphate rock. • We estimate that 11,000 tU may have been recoverable from phosphoric acid in 2010. • Recovery is a resource conservation and environmental pollution control strategy. • To ensure investment in recovery technology, profitability needs to be secured

  19. Uranium endowments in phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Ulrich, Andrea E., E-mail: andrea.ulrich@env.ethz.ch [Institute for Environmental Decisions (IED), Natural and Social Science Interface, ETH Zurich Universitässtrasse 22, 8092 Zurich (Switzerland); Institute for Agricultural Sciences, Plant Nutrition, ETH Zurich, Eschikon 33, 8315 Lindau (Switzerland); Schnug, Ewald, E-mail: e.schnug@tu-braunschweig.de [Department of Life Sciences, Technical University of Braunschweig, Pockelsstraße 14, D-38106 Braunschweig (Germany); Prasser, Horst-Michael, E-mail: prasser@lke.mavt.ethz.ch [Institute of Energy Technology, Laboratory of Nuclear Energy Systems, ETH Zurich, Sonneggstrasse 3, 8092 Zurich (Switzerland); Frossard, Emmanuel, E-mail: emmanuel.frossard@usys.ethz.ch [Institute for Agricultural Sciences, Plant Nutrition, ETH Zurich, Eschikon 33, 8315 Lindau (Switzerland)

    2014-04-01

    This study seeks to identify and specify the components that make up the prospects of U recovery from phosphate rock. A systems approach is taken. The assessment includes i) reviewing past recovery experience and lessons learned; ii) identifying factors that determine recovery; and iii) establishing a contemporary evaluation of U endowments in phosphate rock reserves, as well as the available and recoverable amounts from phosphate rock and phosphoric acid production. We find that in the past, recovery did not fulfill its potential and that the breakup of the Soviet Union worsened then-favorable recovery market conditions in the 1990s. We find that an estimated 5.7 million tU may be recoverable from phosphate rock reserves. In 2010, the recoverable tU from phosphate rock and phosphoric acid production may have been 15,000 tU and 11,000 tU, respectively. This could have filled the world U supply-demand gap for nuclear energy production. The results suggest that the U.S., Morocco, Tunisia, and Russia would be particularly well-suited to recover U, taking infrastructural considerations into account. We demonstrate future research needs, as well as sustainability orientations. We conclude that in order to promote investment and production, it seems necessary to establish long-term contracts at guaranteed prices, ensuring profitability for phosphoric acid producers. - Highlights: • We identify components that underlie the recovery of uranium from phosphate rock. • We estimate that 11,000 tU may have been recoverable from phosphoric acid in 2010. • Recovery is a resource conservation and environmental pollution control strategy. • To ensure investment in recovery technology, profitability needs to be secured.

  20. Phosphorus release from phosphate rock and iron phosphate by low-molecular-weight organic acids.

    Science.gov (United States)

    Xu, Ren-kou; Zhu, Yong-guan; Chittleborough, David

    2004-01-01

    Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phosphate by low-molecular-weight organic acids. Results showed that citric acid had the highest capacity to solubilize P from both rock and iron phosphate. P solubilization from rock phosphate and iron phosphate resulted in net proton consumption. P release from rock phosphate was positively correlated with the pKa values. P release from iron phosphate was positively correlated with Fe-organic acid stability constants except for aromatic acids, but was notcorrelated with pKa. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearly. Addition of phenolic compounds further increased the P release from iron phosphate. Initial solution pH had much more substantial effect on P release from rock phosphate than from iron phosphate.

  1. Politicising participation

    OpenAIRE

    Calderon, Camilo

    2013-01-01

    The involvement of local communities in public space planning and design processes is widely promoted as an essential element of landscape architecture and urban design practice. Despite this, there has been little theorisation of this topic within these fields. Furthermore, the implementation of ideals and principles commonly found in theory are far from becoming mainstream practice, indicating a significant gap between the theory and practice of participation. This thesis aims to contri...

  2. Uranium abundance in some sudanese phosphate ores

    International Nuclear Information System (INIS)

    Adam, A.A.; Eltayeb, M.A.H.

    2009-01-01

    This work was carried out mainly to analysis of some Sudanese phosphate ores, for their uranium abundance and total phosphorus content measured as P 2 O 5 %. For this purpose, 30 samples of two types of phosphate ore from Eastern Nuba Mountains, in Sudan namely, Kurun and Uro areas were examined. In addition, the relationship between uranium and major, and trace elements were obtained, also, the natural radioactivity of the phosphate samples was measured, in order to characterize and differentiate between the two types of phosphate ores. The uranium abundance in Uro phosphate with 20.3% P 2 O 5 is five time higher than in Kurun phosphate with 26.7% P 2 O 5 . The average of uranium content was found to be 56.6 and 310 mg/kg for Kurun and Uro phosphate ore, respectively. The main elements in Kurun and Uro phosphate ore are silicon, aluminum, and phosphorus, while the most abundant trace elements in these two ores are titanium, strontium and barium. Pearson correlation coefficient revealed that uranium in Kurun phosphate shows strong positive correlation with P 2 O 5 , and its distribution is essentially controlled by the variations of P2O5 concentration, whereas uranium in Uro phosphate shows strong positive correlation with strontium, and its distribution is controlled by the variations of Sr concentration. Uranium behaves in different ways in Kurun phosphate and in Uro phosphate. Uro phosphate shows higher concentrations of all the estimated radionuclides than Kurun phosphate. According to the obtained results, it can be concluded that Uro phosphate is consider as secondary uranium source, and is more suitable for uranium recovery, because it has high uranium abundance and low P 2 O 5 %, than Kurun phosphate. (authors) [es

  3. Occurrence and functioning of phosphate solubilizing ...

    African Journals Online (AJOL)

    Occurrence and functioning of phosphate solubilizing microorganisms from oil palm tree ( Elaeis guineensis ) rhizosphere in Cameroon. ... While the use of soluble mineral phosphate fertilizers is the obvious best means to combat phosphate ... in order to improve agricultural production, using low inputs technology. Isolates ...

  4. Energy hyperspace for stacking interaction in AU/AU dinucleotide step: Dispersion-corrected density functional theory study.

    Science.gov (United States)

    Mukherjee, Sanchita; Kailasam, Senthilkumar; Bansal, Manju; Bhattacharyya, Dhananjay

    2014-01-01

    Double helical structures of DNA and RNA are mostly determined by base pair stacking interactions, which give them the base sequence-directed features, such as small roll values for the purine-pyrimidine steps. Earlier attempts to characterize stacking interactions were mostly restricted to calculations on fiber diffraction geometries or optimized structure using ab initio calculations lacking variation in geometry to comment on rather unusual large roll values observed in AU/AU base pair step in crystal structures of RNA double helices. We have generated stacking energy hyperspace by modeling geometries with variations along the important degrees of freedom, roll, and slide, which were chosen via statistical analysis as maximally sequence dependent. Corresponding energy contours were constructed by several quantum chemical methods including dispersion corrections. This analysis established the most suitable methods for stacked base pair systems despite the limitation imparted by number of atom in a base pair step to employ very high level of theory. All the methods predict negative roll value and near-zero slide to be most favorable for the purine-pyrimidine steps, in agreement with Calladine's steric clash based rule. Successive base pairs in RNA are always linked by sugar-phosphate backbone with C3'-endo sugars and this demands C1'-C1' distance of about 5.4 Å along the chains. Consideration of an energy penalty term for deviation of C1'-C1' distance from the mean value, to the recent DFT-D functionals, specifically ωB97X-D appears to predict reliable energy contour for AU/AU step. Such distance-based penalty improves energy contours for the other purine-pyrimidine sequences also. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 107-120, 2014. Copyright © 2013 Wiley Periodicals, Inc.

  5. The role of complex formation between cytochrome c and nad in the manifestation of the protective effect of dinucleotide with respect to hemoprotein

    International Nuclear Information System (INIS)

    Artyukhov, V.G.; Loboda, T.

    1990-01-01

    UV-irradiation of free ferricytochrome solutions, pH 8, induces photorecovery of protein molecules. Hemoproteide photorecovery does not occur after irradiation of the ferricytochrome c/NAD mixture, pH 6 and 8: dinucleotide exerts a photoprotective effect with respect to ferricytochrome. This NAD effect is not observed afterexposure of the ferricytochrome c/NAD system, pH 4. With this pH value, each component of the above mixture is eluted from a gel-chromatogarphic column by its peak, whereas with pH 6 and 8, NAD and ferricytochrome c leave the column as one fraction. This indicates that the photoprotective effect of the coenzyme manifests itself upon formation of complex with hemoprotein

  6. Molecular diagnosis of Prader-Willi syndrome: Parent-of-origin dependent methylation sites and non-isotopic detection of (CA){sub n} dinucleotide repeat polymorphisms

    Energy Technology Data Exchange (ETDEWEB)

    Lerer, I.; Meiner, V.; Pashut-Lavon, I.; Abeliovich, D.

    1994-08-01

    We describe our experience in the molecular diagnosis of 22 patients suspected of Prader-Willi syndrome (PWS) using a DNA probe PW71 (D15S63) which detects a parent-of-origin specific methylated site in the PWS critical region. The cause of the syndrome was determined as deletion or uniparental disomy according to the segregation of (CA){sub n} dinucleotide repeat polymorphisms of the PWS/AS region and more distal markers of chromosome 15. In 10 patients the clinical diagnosis was confirmed by the segregation of (CA){sub n}, probably due to paternal microdeletion in the PWs critical region which did not include the loci D15S97, D15S113, GABRB3, and GABRA5. This case demonstrates the advantage of the DNA probe PW71 in the diagnosis of PWS. 31 refs., 2 figs., 3 tabs.

  7. Claiming Participation

    DEFF Research Database (Denmark)

    Fabian, Louise; Samson, Kristine

    2015-01-01

    The article discuss the conflicts, potentials and possible alliances of do-it-yourself (DIY) urbanism when it takes the form of spontaneous place appropriations, when it is performed as participatory urban design and when it is integrated strategically in planning. DIY urbanism and experimentation...... with participation are currently strong influential factors in Danish planning. The article explores the use of participatory DIY urban design in two cases: the relocation of beer drinkers in Enghave Square and the Carlsberg City development in Copenhagen, Denmark. Carlsberg City is the most thorough Danish example...

  8. Exploring the Link between Serum Phosphate Levels and Low Muscle Strength, Dynapenia, and Sarcopenia.

    Science.gov (United States)

    Chen, Yuan-Yuei; Kao, Tung-Wei; Chou, Cheng-Wai; Wu, Chen-Jung; Yang, Hui-Fang; Lai, Ching-Huang; Wu, Li-Wei; Chen, Wei-Liang

    2018-02-23

    Emerging evidences addressed an association between phosphate and muscle function. Because little attention was focused on this issue, the objective of our study was to explore the relationship of phosphate with muscle strength, dynapenia, and sarcopenia. From the National Health and Nutrition Examination Survey, a total of 7421 participants aged 20 years or older were included in our study with comprehensive examinations included anthropometric parameters, strength of the quadriceps muscle, and appendicular lean masses. Within the normal range of serum phosphate, we used quartile-based analyses to determine the potential relationships of serum phosphate with dynapenia, and sarcopenia through multivariate regression models. After adjusting for the pertinent variables, an inverse association between the serum phosphate quartiles and muscle strength was observed and the linear association was stronger than other anthropometric parameters. Notably, the significant association between phosphate and muscle strength was existed in >65 years old age group, not in 20-65 years old. The higher quartiles of phosphate had higher likelihood for predicting the presence of dynapenia rather than sarcopenia in entire population. Our study highlighted that higher quartiles of phosphate had significant association with lower muscle strength and higher risks for predicting the presence of dynapenia.

  9. Zirconium Phosphate Supported MOF Nanoplatelets.

    Science.gov (United States)

    Kan, Yuwei; Clearfield, Abraham

    2016-06-06

    We report a rare example of the preparation of HKUST-1 metal-organic framework nanoplatelets through a step-by-step seeding procedure. Sodium ion exchanged zirconium phosphate, NaZrP, nanoplatelets were judiciously selected as support for layer-by-layer (LBL) assembly of Cu(II) and benzene-1,3,5-tricarboxylic acid (H3BTC) linkers. The first layer of Cu(II) is attached to the surface of zirconium phosphate through covalent interaction. The successive LBL growth of HKUST-1 film is then realized by soaking the NaZrP nanoplatelets in ethanolic solutions of cupric acetate and H3BTC, respectively. The amount of assembled HKUST-1 can be readily controlled by varying the number of growth cycles, which was characterized by powder X-ray diffraction and gas adsorption analyses. The successful construction of HKUST-1 on NaZrP was also supported by its catalytic performance for the oxidation of cyclohexene.

  10. Phosphate-a poison for humans?

    Science.gov (United States)

    Komaba, Hirotaka; Fukagawa, Masafumi

    2016-10-01

    Maintenance of phosphate balance is essential for life, and mammals have developed a sophisticated system to regulate phosphate homeostasis over the course of evolution. However, due to the dependence of phosphate elimination on the kidney, humans with decreased kidney function are likely to be in a positive phosphate balance. Phosphate excess has been well recognized as a critical factor in the pathogenesis of mineral and bone disorders associated with chronic kidney disease, but recent investigations have also uncovered toxic effects of phosphate on the cardiovascular system and the aging process. Compelling evidence also suggests that increased fibroblastic growth factor 23 and parathyroid hormone levels in response to a positive phosphate balance contribute to adverse clinical outcomes. These insights support the current practice of managing serum phosphate in patients with advanced chronic kidney disease, although definitive evidence of these effects is lacking. Given the potential toxicity of excess phosphate, the general population may also be viewed as a target for phosphate management. However, the widespread implementation of dietary phosphate intervention in the general population may not be warranted due to the limited impact of increased phosphate intake on mineral metabolism and clinical outcomes. Nonetheless, the increasing incidence of kidney disease or injury in our aging society emphasizes the potential importance of this issue. Further work is needed to more completely characterize phosphate toxicity and to establish the optimal therapeutic strategy for managing phosphate in patients with chronic kidney disease and in the general population. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  11. Phosphate vibrations as reporters of DNA hydration

    Science.gov (United States)

    Corcelli, Steven

    The asymmetric phosphate stretch vibrational frequency is extraordinarily sensitive to its local solvent environment. Using density functional theory calculations on the model compound dimethyl phosphate, the asymmetric phosphate stretch vibrational frequency was found to shift linearly with the magnitude of an electric field along the symmetry axis of the PO2 moiety (i.e. the asymmetric phosphate stretch is an excellent linear vibrational Stark effect probe). With this linear relationship established, asymmetric phosphate stretch vibrational frequencies were computed during the course of a molecular dynamics simulation of fully hydrated DNA. Moreover, contributions to shifts in the frequencies from subpopulations of water molecules (e.g. backbone, minor groove, major groove, etc.) were calculated to reveal how phosphate vibrations report the onset of DNA hydration in experiments that vary the relative humidity of non-condensing (dry) DNA samples.

  12. Application of Calcium Phosphate Materials in Dentistry

    Directory of Open Access Journals (Sweden)

    Jabr S. Al-Sanabani

    2013-01-01

    Full Text Available Calcium phosphate materials are similar to bone in composition and in having bioactive and osteoconductive properties. Calcium phosphate materials in different forms, as cements, composites, and coatings, are used in many medical and dental applications. This paper reviews the applications of these materials in dentistry. It presents a brief history, dental applications, and methods for improving their mechanical properties. Notable research is highlighted regarding (1 application of calcium phosphate into various fields in dentistry; (2 improving mechanical properties of calcium phosphate; (3 biomimetic process and functionally graded materials. This paper deals with most common types of the calcium phosphate materials such as hydroxyapatite and tricalcium phosphate which are currently used in dental and medical fields.

  13. Protonation mechanism and location of rate-determining steps for the Ascaris suum nicotinamide adenine dinucleotide-malic enzyme reaction from isotope effects and pH studies

    International Nuclear Information System (INIS)

    Kiick, D.M.; Harris, B.G.; Cook, P.F.

    1986-01-01

    The pH dependence of the kinetic parameters and the primary deuterium isotope effects with nicotinamide adenine dinucleotide (NAD) and also thionicotinamide adenine dinucleotide (thio-NAD) as the nucleotide substrates were determined in order to obtain information about the chemical mechanism and location of rate-determining steps for the Ascaris suum NAD-malic enzyme reaction. The maximum velocity with thio-NAD as the nucleotide is pH-independent from pH 4.2 to 9.6, while with NAD, V decreases below a pK of 4.8. V/K for both nucleotides decreases below a pK of 5.6 and above a pK of 8.9. Both the tartronate pKi and V/Kmalate decrease below a pK of 4.8 and above a pK of 8.9. Oxalate is competitive vs. malate above pH 7 and noncompetitive below pH 7 with NAD as the nucleotide. The oxalate Kis increases from a constant value above a pK of 4.9 to another constant value above a pK of 6.7. The oxalate Kii also increases above a pK of 4.9, and this inhibition is enhanced by NADH. In the presence of thio-NAD the inhibition by oxalate is competitive vs. malate below pH 7. For thio-NAD, both DV and D(V/K) are pH-independent and equal to 1.7. With NAD as the nucleotide, DV decreases to 1.0 below a pK of 4.9, while D(V/KNAD) and D(V/Kmalate) are pH-independent. Above pH 7 the isotope effects on V and the V/K values for NAD and malate are equal to 1.45, the pH-independent value of DV above pH 7. Results indicate that substrates bind to only the correctly protonated form of the enzyme. Two enzyme groups are necessary for binding of substrates and catalysis. Both NAD and malate are released from the Michaelis complex at equal rates which are equal to the rate of NADH release from E-NADH above pH 7. Below pH 7 NADH release becomes more rate-determining as the pH decreases until at pH 4.0 it completely limits the overall rate of the reaction

  14. Crystalline cerium(IV) phosphates

    International Nuclear Information System (INIS)

    Herman, R.G.; Clearfield, A.

    1976-01-01

    The ion exchange behaviour of seven crystalline cerium(IV) phosphates towards some of the alkali metal cations is described. Only two of the compounds (A and C) possess ion exchange properties in acidic solutions. Four others show some ion exchange characteristics in basic media with some of the alkali cations. Compound G does not behave as an ion exchanger in solutions of pH + , but show very little Na + uptake. Compound E undergoes ion exchange with Na + and Cs + , but not with Li+. Both Li + and Na + are sorbed by compounds A and C. The results are indicative of structures which show steric exclusion phenomena. (author)

  15. Radiological impact of use of phosphate fertilizers

    International Nuclear Information System (INIS)

    Shukla, V.K.; Chinnaesakki, S.; Sartandel, S.J.; Shanbhag, A.A.; Puranik, V.D.

    2003-01-01

    The paper describes the results of gamma spectrometric measurements of 238 U, 233 Th, 226 Ra and 40 K in rock phosphates and various types of phosphate fertilizers and by-products. The increase in soil natural radioactivity has been assessed for major Indian crops. No significant increase in soil natural radioactivity is expected due to the application of phosphate fertilizers for agricultural productions. (author)

  16. Uranium and heavy metals in phosphate fertilizers

    International Nuclear Information System (INIS)

    Khater, Ashraf E.M.; King Saud University, Riyadh

    2008-01-01

    Full text: Agricultural applications of chemical fertilizers are a worldwide practice. The specific activity of uranium-238 and heavy metals in phosphate fertilizers depends on the phosphate ore from which the fertilizer produced and on the chemical processing of the ore. Composite phosphate fertilizers samples were collected and the uranium-238 specific activity, in Bq/kg, and As, Cd, Cu, Pb, Se concentration were measured. The annual addition of these elements in soil due to soil fertilization were calculated and discussed. (author)

  17. Calcium phosphates: what is the evidence?

    Science.gov (United States)

    Larsson, Sune

    2010-03-01

    A number of different calcium phosphate compounds such as calcium phosphate cements and solid beta-tricalcium phosphate products have been introduced during the last decade. The chemical composition mimics the mineral phase of bone and as a result of this likeness, the materials seem to be remodeled as for normal bone through a cell-mediated process that involves osteoclastic activity. This is a major difference when compared with, for instance, calcium sulphate compounds that after implantation dissolve irrespective of the new bone formation rate. Calcium phosphates are highly biocompatible and in addition, they act as synthetic osteoconductive scaffolds after implantation in bone. When placed adjacent to bone, osteoid is formed directly on the surface of the calcium phosphate with no soft tissue interposed. Remodeling is slow and incomplete, but by adding more and larger pores, like in ultraporous beta-tricalcium phosphate, complete or nearly complete resorption can be achieved. The indications explored so far include filling of metaphyseal fracture voids or bone cysts, a volume expander in conjunction with inductive products, and as a carrier for various growth factors and antibiotics. Calcium phosphate compounds such as calcium phosphate cement and beta-tricalcium phosphate will most certainly be part of the future armamentarium when dealing with fracture treatment. It is reasonable to believe that we have so far only seen the beginning when it comes to clinical applications.

  18. Biosynthesis and characterization of layered iron phosphate

    International Nuclear Information System (INIS)

    Zhou Weijia; He Wen; Wang Meiting; Zhang Xudong; Yan Shunpu; Tian Xiuying; Sun Xianan; Han Xiuxiu; Li Peng

    2008-01-01

    Layered iron phosphate with uniform morphology has been synthesized by a precipitation method with yeast cells as a biosurfactant. The yeast cells are used to regulate the nucleation and growth of layered iron phosphate. The uniform layered structure is characterized by small-angle x-ray diffraction (SAXD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses. Fourier transform infrared spectroscopy (FT-IR) is used to analyze the chemical bond linkages in organic–inorganic hybrid iron phosphate. The likely synthetic mechanism of nucleation and oriented growth is discussed. The electrical conductivity of hybrid iron phosphate heat-treated at different temperatures is presented

  19. [Phosphate-solubilizing activity of aerobic methylobacteria].

    Science.gov (United States)

    Agafonova, N V; Kaparullina, E N; Doronina, N V; Trotsenko, Iu A

    2014-01-01

    Phosphate-solubilizing activity was found in 14 strains of plant-associated aerobic methylobacteria belonging to the genera Methylophilus, Methylobacillus, Methylovorus, Methylopila, Methylobacterium, Delftia, and Ancyclobacter. The growth of methylobacteria on medium with methanol as the carbon and energy source and insoluble tricalcium phosphate as the phosphorus source was accompanied by a decrease in pH due to the accumulation of up to 7 mM formic acid as a methanol oxidation intermediate and by release of 120-280 μM phosphate ions, which can be used by both bacteria and plants. Phosphate-solubilizing activity is a newly revealed role of methylobacteria in phytosymbiosis.

  20. Synthesis of amorphous acid iron phosphate nanoparticles

    International Nuclear Information System (INIS)

    Palacios, E.; Leret, P.; Fernández, J. F.; Aza, A. H. De; Rodríguez, M. A.

    2012-01-01

    A simple method to precipitate nanoparticles of iron phosphate with acid character has been developed in which the control of pH allows to obtain amorphous nanoparticles. The acid aging of the precipitated amorphous nanoparticles favored the P–O bond strength that contributes to the surface reordering, the surface roughness and the increase of the phosphate acid character. The thermal behavior of the acid iron phosphate nanoparticles has been also studied and the phosphate polymerization at 400 °C produces strong compacts of amorphous nanoparticles with interconnected porosity.

  1. Method of stripping plutonium from tributyl phosphate solution which contains dibutyl phosphate-plutonium stable complexes

    International Nuclear Information System (INIS)

    Ochsenfeld, W.; Schmieder, H.

    1976-01-01

    Fast breeder fuel elements which have been highly burnt-up are reprocessed by extracting uranium and plutonium into an organic solution containing tributyl phosphate. The tributyl phosphate degenerates at least partially into dibutyl phosphate and monobutyl phosphate, which form stable complexes with tetravalent plutonium in the organic solution. This tetravalent plutonium is released from its complexed state and stripped into aqueous phase by contacting the organic solution with an aqueous phase containing tetravalent uranium. 6 claims, 1 drawing figure

  2. Bio-treatment of phosphate from synthetic wastewater using ...

    African Journals Online (AJOL)

    In this study, the efficient phosphate utilizing isolates were used to remove phosphate from synthetic phosphate wastewater was tested using batch scale process. Hence the objective of the present study was to examine the efficiency of bacterial species individually for the removal of phosphate from synthetic phosphate ...

  3. The rates of G:C[yields]T:A and G:C[yields]C:G transversions at CpG dinucleotides in the human factor IX gene

    Energy Technology Data Exchange (ETDEWEB)

    Ketterling, R.P.; Vielhaber, E.; Sommer, S.S. (Mayo Clinic/Foundation, Rochester, MN (United States))

    1994-05-01

    The authors have identified eight independent transversions at CpG in 290 consecutive families with hemophilia B. These eight transversions account for 16.3% of all independent transversions in the sample, yet the expected frequency of CpG transversions at random in the factor IX gene is only 2.6% (P<0.1). The aggregate data suggest that the two types of CpG transversions (G:C[yields]T:A and G:C[yields]C:G) possess similar mutation rates (24.8 [times] 10[sup [minus]10] and 20.6 [times] 10[sup [minus]10], respectively), which are about fivefold greater than the comparable rates for transversions at non-CpG dinucleotides. The enhancement of transversions at CpG suggest that the model by which mutations occur at CpG may need to be reevaluated. The relationship, if any, between deamination of 5-methyl cytosine and enhancement of transversions at CpG remains to be defined. 28 refs., 2 tabs.

  4. Protective effect of nicotinamide adenine dinucleotide (NAD+) against spinal cord ischemia-reperfusion injury via reducing oxidative stress-induced neuronal apoptosis.

    Science.gov (United States)

    Xie, Lei; Wang, Zhenfei; Li, Changwei; Yang, Kai; Liang, Yu

    2017-02-01

    As previous studies demonstrate that oxidative stress and apoptosis play crucial roles in ischemic pathogenesis and nicotinamide adenine dinucleotide (NAD + ) treatment attenuates oxidative stress-induced cell death among primary neurons and astrocytes as well as significantly reduce cerebral ischemic injury in rats. We used a spinal cord ischemia injury (SCII) model in rats to verify our hypothesis that NAD + could ameliorate oxidative stress-induced neuronal apoptosis. Adult male rats were subjected to transient spinal cord ischemia for 60min, and different doses of NAD + were administered intraperitoneally immediately after the start of reperfusion. Neurological function was determined by Basso, Beattie, Bresnahan (BBB) scores. The oxidative stress level was assessed by superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. The degree of apoptosis was analyzed by deoxyuridinetriphosphate nick-end labeling (TUNEL) staining and protein levels of cleaved caspase-3 and AIF (apoptosis inducing factor). The results showed that NAD + at 50 or 100mg/kg significantly decreased the oxidative stress level and neuronal apoptosis in the spinal cord of ischemia-reperfusion rats compared with saline, as accompanied with the decreased oxidative stress, NAD + administration significantly restrained the neuronal apoptosis after ischemia injury while improved the neurological and motor function. These findings suggested that NAD + might protect against spinal cord ischemia-reperfusion via reducing oxidative stress-induced neuronal apoptosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Nicotinamide nucleotide transhydrogenase from Rhodobacter capsulatus; the H+/H- ratio and the activation state of the enzyme during reduction of acetyl pyridine adenine dinucleotide.

    Science.gov (United States)

    Palmer, T; Jackson, J B

    1992-02-21

    Chromatophores from Rhodobacter capsulatus were incubated in the dark with NADPH and acetylpyridineadenine dinucleotide (AcPdAD+) in the presence of different concentrations of myxothiazol. The transhydrogenase activity was monitored until an appropriate mass action ratio, [AcPdAD+][NADPH]/[AcPdADH][NADP+], was reached. The sample was then illuminated and the initial rate of either AcPdAD+ reduction by NADPH or AcPdADH oxidation by NADP+ was recorded. The ratio of H+ translocated per H- equivalent transferred by transhydrogenase was calculated from the value of the membrane potential (delta pH = 0) at which illumination caused no net reaction in either direction. The mean value for the H+/H- ratio was 0.55. At greater values of [AcPdAD+][NADPH]/[AcPdADH][NADP+] than were employed in the above experiments and over a wider range of concentrations of myxothiazol, it was found that incremental increases in the membrane potential always gave rise to a decrease, never an increase in the rate of AcPdAD+ reduction. In contrast to the H(+)-ATP synthase, there is no evidence of any activation/deactivation of H(+)-transhydrogenase by the protonmotive force.

  6. Deficiency of the iron-sulfur clusters of mitochondrial reduced nicotinamide-adenine dinucleotide-ubiquinone oxidoreductase (complex I) in an infant with congenital lactic acidosis.

    Science.gov (United States)

    Moreadith, R W; Batshaw, M L; Ohnishi, T; Kerr, D; Knox, B; Jackson, D; Hruban, R; Olson, J; Reynafarje, B; Lehninger, A L

    1984-09-01

    We report the case of an infant with hypoglycemia, progressive lactic acidosis, an increased serum lactate/pyruvate ratio, and elevated plasma alanine, who had a moderate to profound decrease in the ability of mitochondria from four organs to oxidize pyruvate, malate plus glutamate, citrate, and other NAD+-linked respiratory substrates. The capacity to oxidize the flavin adenine dinucleotide-linked substrate, succinate, was normal. The most pronounced deficiency was in skeletal muscle, the least in kidney mitochondria. Enzymatic assays on isolated mitochondria ruled out defects in complexes II, III, and IV of the respiratory chain. Further studies showed that the defect was localized in the inner membrane mitochondrial NADH-ubiquinone oxidoreductase (complex I). When ferricyanide was used as an artificial electron acceptor, complex I activity was normal, indicating that electrons from NADH could reduce the flavin mononucleotide cofactor. However, electron paramagnetic resonance spectroscopy performed on liver submitochondrial particles showed an almost total loss of the iron-sulfur clusters characteristic of complex I, whereas normal signals were noted for other mitochondrial iron-sulfur clusters. This infant is presented as the first reported case of congenital lactic acidosis caused by a deficiency of the iron-sulfur clusters of complex I of the mitochondrial electron transport chain.

  7. Expansion of GA Dinucleotide Repeats Increases the Density of CLAMP Binding Sites on the X-Chromosome to Promote Drosophila Dosage Compensation.

    Directory of Open Access Journals (Sweden)

    Guray Kuzu

    2016-07-01

    Full Text Available Dosage compensation is an essential process that equalizes transcript levels of X-linked genes between sexes by forming a domain of coordinated gene expression. Throughout the evolution of Diptera, many different X-chromosomes acquired the ability to be dosage compensated. Once each newly evolved X-chromosome is targeted for dosage compensation in XY males, its active genes are upregulated two-fold to equalize gene expression with XX females. In Drosophila melanogaster, the CLAMP zinc finger protein links the dosage compensation complex to the X-chromosome. However, the mechanism for X-chromosome identification has remained unknown. Here, we combine biochemical, genomic and evolutionary approaches to reveal that expansion of GA-dinucleotide repeats likely accumulated on the X-chromosome over evolutionary time to increase the density of CLAMP binding sites, thereby driving the evolution of dosage compensation. Overall, we present new insight into how subtle changes in genomic architecture, such as expansions of a simple sequence repeat, promote the evolution of coordinated gene expression.

  8. Pentose phosphates in nucleoside interconversion and catabolism.

    Science.gov (United States)

    Tozzi, Maria G; Camici, Marcella; Mascia, Laura; Sgarrella, Francesco; Ipata, Piero L

    2006-03-01

    Ribose phosphates are either synthesized through the oxidative branch of the pentose phosphate pathway, or are supplied by nucleoside phosphorylases. The two main pentose phosphates, ribose-5-phosphate and ribose-1-phosphate, are readily interconverted by the action of phosphopentomutase. Ribose-5-phosphate is the direct precursor of 5-phosphoribosyl-1-pyrophosphate, for both de novo and 'salvage' synthesis of nucleotides. Phosphorolysis of deoxyribonucleosides is the main source of deoxyribose phosphates, which are interconvertible, through the action of phosphopentomutase. The pentose moiety of all nucleosides can serve as a carbon and energy source. During the past decade, extensive advances have been made in elucidating the pathways by which the pentose phosphates, arising from nucleoside phosphorolysis, are either recycled, without opening of their furanosidic ring, or catabolized as a carbon and energy source. We review herein the experimental knowledge on the molecular mechanisms by which (a) ribose-1-phosphate, produced by purine nucleoside phosphorylase acting catabolically, is either anabolized for pyrimidine salvage and 5-fluorouracil activation, with uridine phosphorylase acting anabolically, or recycled for nucleoside and base interconversion; (b) the nucleosides can be regarded, both in bacteria and in eukaryotic cells, as carriers of sugars, that are made available though the action of nucleoside phosphorylases. In bacteria, catabolism of nucleosides, when suitable carbon and energy sources are not available, is accomplished by a battery of nucleoside transporters and of inducible catabolic enzymes for purine and pyrimidine nucleosides and for pentose phosphates. In eukaryotic cells, the modulation of pentose phosphate production by nucleoside catabolism seems to be affected by developmental and physiological factors on enzyme levels.

  9. Lack of awareness among future medical professionals about the risk of consuming hidden phosphate-containing processed food and drinks.

    Directory of Open Access Journals (Sweden)

    Yoshiko Shutto

    Full Text Available Phosphate toxicity is an important determinant of mortality in patients with chronic kidney disease (CKD, particularly those undergoing hemodialysis treatments. CKD patients are advised to take a low phosphate-containing diet, and are additionally prescribed with phosphate-lowering drugs. Since these patients usually seek guidance from their physicians and nurses for their dietary options, we conducted a survey to determine the levels of awareness regarding the high phosphate content in commercially processed food and drinks among medical and nursing students at the Hirosaki University School of Medicine in Japan. For this survey, 190 medical and nursing students (average age 21.7±3 years were randomly selected, and provided with a list of questions aimed at evaluating their awareness of food and drinks containing artificially added phosphate ingredients. While 98.9% of these students were aware of the presence of sugar in commercially available soda drinks, only 6.9% were aware of the presence of phosphate (phosphoric acid. Similarly, only 11.6% of these students were aware of the presence of phosphate in commercially processed food, such as hamburgers and pizza. Moreover, around two thirds of the surveyed students (67.7% were unaware of the harmful effects of unrestricted consumption of phosphate-containing food and drinks. About 28% of the surveyed students consume such "fast food" once a week, while 40% drink at least 1∼5 cans of soda drinks/week. After realizing the potential long-term risks of consuming excessive phosphate-containing food and drinks, 40.5% of the survey participants considered reducing their phosphate intake by minimizing the consumption of commercially processed "fast food" items and soda drinks. Moreover, another 48.4% of students showed interest in obtaining more information on the negative health effects of consuming excessive amounts of phosphate. This survey emphasizes the need for educational initiative to raise

  10. [Intensity of pentose phosphate metabolism of carbohydrates in various brain areas in normal and starved animals].

    Science.gov (United States)

    Kerimov, B F

    2002-01-01

    The activities of key enzymes of pentose phosphate pathway, glucose-6-phosphate dehydrogenase (G-6 PD) and 6-phosphogluconate dehydrogenase (6-PGD), were studied in cytoplasmatic fractions of brain cortical (limbic, orbital, sensorimotor cortex) and subcortical (myelencefalon, mesencefalon, hypothalamus) structures of rats subjected to starvation for 1, 2, 3, 5 and 7 days. Short-term starvation (1-3 days) caused activation of 6-GPD and 6-PGD both in cortical and subcortical structures. Long-term starvation for 5-7 days caused a decrease of activities of the pentose phosphate pathway enzymes in all studied structures. It is suggested that enzymes of pentose phosphate pathway in nervous tissues are functionally and metabolically related to glutathione system and during starvation they indirectly participate in the regulation lipid peroxidation processes.

  11. Removal of phosphate from solution by adsorption and precipitation of calcium phosphate onto monohydrocalcite.

    Science.gov (United States)

    Yagi, Shintaro; Fukushi, Keisuke

    2012-10-15

    The sorption behavior and mechanism of phosphate on monohydrocalcite (CaCO(3)·H(2)O: MHC) were examined using batch sorption experiments as a function of phosphate concentrations, ionic strengths, temperatures, and reaction times. The mode of PO(4) sorption is divisible into three processes depending on the phosphate loading. At low phosphate concentrations, phosphate is removed by coprecipitation of phosphate during the transformation of MHC to calcite. The sorption mode at the low-to-moderate phosphate concentrations is most likely an adsorption process because the sorption isotherm at the conditions can be fitted reasonably with the Langmuir equation. The rapid sorption kinetics at the conditions is also consistent with the adsorption reaction. The adsorption of phosphate on MHC depends strongly on ionic strength, but slightly on temperature. The maximum adsorption capacities of MHC obtained from the regression of the experimental data to the Langmuir equation are higher than those reported for stable calcium carbonate (calcite or aragonite) in any conditions. At high phosphate concentrations, the amount of sorption deviates from the Langmuir isotherm, which can fit the low-to-moderate phosphate concentrations. Speciation-saturation analyses of the reacted solutions at the conditions indicated that the solution compositions which deviate from the Langmuir equation are supersaturated with respect to a certain calcium phosphate. The obtained calcium phosphate is most likely amorphous calcium phosphate (Ca(3)(PO(4))(2)·xH(2)O). The formation of the calcium phosphate depends strongly on ionic strength, temperature, and reaction times. The solubility of MHC is higher than calcite and aragonite because of its metastability. Therefore, the higher solubility of MHC facilitates the formation of the calcium phosphates more than with calcite and aragonite. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Cyanotoxins: a poison that frees phosphate.

    Science.gov (United States)

    Raven, John A

    2010-10-12

    Autotrophic organisms obtain phosphorus from the environment by secreting alkaline phosphatases that act on esters, resulting in inorganic phosphate that is then taken up. New work shows that the cyanobacterium Aphanizomenon ovalisporum obtains inorganic phosphate by secreting the cyanotoxin cylindrospermopsin, which induces alkaline phosphatase in other phytoplankton species. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Phosphate recycling in the phosphorus industry

    NARCIS (Netherlands)

    Schipper, W.J.; Klapwijk, A.; Potjer, A.; Rulkens, W.H.; Temmink, B.G.; Kiestra, F.D.G.; Lijmbach, A.C.M.

    2001-01-01

    The feasibility of phosphate recycling in the white phosphorus production process is discussed. Several types of materials may be recycled, provided they are dry inorganic materials, low in iron, copper and zinc. Sewage sludge ash may be used if no iron is used for phosphate precipitation in the

  14. Photoelectron spectroscopy of phosphites and phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Chattopadhyay, S.; Findley, G.L.; McGlynn, S.P.

    1981-01-01

    The ultraviolet photoelectron spectra (UPS) of trimethyl and triethyl phosphite, trimethyl and triethyl phosphate and four substituted phosphates are presented. Assignments are based on analogies to the UPS of phosphorus trichloride and phosphoryl trichloride and are substantiated by CNDO/2 computations. The mechanisms of P-O (axial) bond formation is discussed.

  15. Phosphate recycling in the phosphorus industry

    NARCIS (Netherlands)

    Schipper, W.J.; Klapwijk, A.; Potjer, B.; Rulkens, W.H.; Temmink, B.G.; Kiestra, F.D.G.; Lijmbach, A.C.M.

    2004-01-01

    The article describes the potential and limitations for recovery of phosphate from secondary materials in the production process for white phosphorus. This thermal process involves the feeding of phosphate rock, cokes and pebbles to a furnace. The reducing conditions in the furnace promote the

  16. Rock phosphate solubilization by the ectomycorrhizal fungus ...

    African Journals Online (AJOL)

    SAM

    2014-06-18

    Jun 18, 2014 ... To evaluate phosphate solubilization of ... and MHB had the potential to solubilize these phosphates by decreasing the pH and confirmed that ... Minerals like N, P, K, Ca, S, Zn, Cu and Sr are ... sterile distilled water, chopped, homogenized in 10 ml sterile .... The role of carbon source is important in mineral.

  17. Genetics Home Reference: glucose phosphate isomerase deficiency

    Science.gov (United States)

    ... glycolytic pathway; in this step, a molecule called glucose-6-phosphate is converted to another molecule called fructose-6-phosphate. When GPI remains a single molecule (a monomer) it is involved in the development and maintenance of nerve cells ( neurons ). In this context, it is often known as ...

  18. Mineral phosphate solubilizing bacterial community in agro-ecosystem

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-15

    Dec 15, 2009 ... patterns. Four insoluble phosphate sources; purulia rock phosphate (PRP), mussourie rock phosphate. (MRP) ... community composition analysis (Garland, 1996a) and ..... the threshold level that enabled only a few species to.

  19. Sonochemical precipitation of amorphous uranium phosphates from trialkyl phosphate solutions and their thermal conversion to UP2O7

    Czech Academy of Sciences Publication Activity Database

    Doroshenko, I.; Žurková, J.; Moravec, Z.; Bezdička, Petr; Pinkas, J.

    2015-01-01

    Roč. 26, SEP (2015), s. 157-162 ISSN 1350-4177 Institutional support: RVO:61388980 Keywords : Uranium * Phosphates * Sonochemistry * Nuclear waste * Trimethyl phosphate * Triethyl phosphate Subject RIV: CA - Inorganic Chemistry Impact factor: 4.556, year: 2015

  20. Sodium Phosphate Supplementation and Time Trial Performance in Female Cyclists

    Directory of Open Access Journals (Sweden)

    Christopher L. Buck

    2014-09-01

    Full Text Available This study investigated the effects of three doses of sodium phosphate (SP supplementation on cycling 500 kJ (119.5 Kcal time trial (TT performance in female cyclists. Thirteen cyclists participated in a randomised, Latin-square design study where they completed four separate trials after ingesting either a placebo, or one of three different doses (25, 50 or 75 mg·kg-1 fat free mass: FFM of trisodium phosphate dodecahydrate which was split into four equal doses a day for six days. On the day after the loading phase, the TT was performed on a cycle ergometer. Serum phosphate blood samples were taken at rest both before and after each loading protocol, while a ~21 day washout period separated each loading phase. No significant differences in TT performance were observed between any of the supplementation protocols (p = 0.73 with average completion times for the 25, 50 or 75 mg·kg-1 FFM being, 42:21 ± 07:53, 40:55 ± 07:33 and 40:38 ± 07:20 min respectively, and 40:39 ± 07:51 min for the placebo. Likewise, average and peak power output did not significantly differ between trials (p = 0.06 and p = 0.46, respectively. Consequently, 500 kJ cycling TT performance was not different in any of the supplementation protocols in female cyclists.

  1. Glucose and fructose 6-phosphate cycle in humans

    International Nuclear Information System (INIS)

    Karlander, S.; Roovete, A.; Vranic, M.; Efendic, S.

    1986-01-01

    We have determined the rate of glucose cycling by comparing turnovers of [2- 3 H]- and [6- 3 H]glucose under basal conditions and during a glucose infusion. Moreover, the activity of the fructose 6-phosphate cycle was assessed by comparing [3- 3 H]- and [6- 3 H]glucose. The study included eight lean subjects with normal glucose tolerance. They participated in two randomly performed investigations. In one experiment [2- 3 H]- and [6- 3 H]glucose were given simultaneously, while in the other only [3- 3 H]glucose was given. The basal rate of glucose cycling was 0.32 +/- 0.08 mg X kg-1 X min-1 or 17% of basal glucose production (P less than 0.005). During glucose infusion the activity of endogenous glucose cycling did not change but since glucose production was suppressed it amounted to 130% of glucose production. The basal fructose 6-phosphate cycle could be detected only in three subjects and was suppressed during glucose infusion. In conclusion, the glucose cycle is active in healthy humans both in basal conditions and during moderate hyperglycemia. In some subjects, the fructose 6-phosphate cycle also appears to be active. Thus it is preferable to use [6- 3 H]glucose rather than [3- 3 H]glucose when measuring glucose production and particularly when assessing glucose cycle

  2. Pyridine nucleotide cycle of Salmonella typhimurium: isolation and characterization of pncA, pncB, and pncC mutants and utilization of exogenous nicotinamide adenine dinucleotide.

    Science.gov (United States)

    Foster, J W; Kinney, D M; Moat, A G

    1979-03-01

    Mutants of Salmonella typhimurium LT-2 deficient in nicotinamidase activity (pncA) or nicotinic acid phosphoribosyltransferase activity (pncB) were isolated as resistant to analogs of nicotinic acid and nicotinamide. Information obtained from interrupted mating experiments placed the pncA gene at 27 units and the pncB gene at 25 units on the S. typhimurium LT-2 linkage map. A major difference in the location of the pncA gene was found between the S. typhimurium and Escherichia coli linkage maps. The pncA gene is located in a region in which there is a major inversion of the gene order in S. typhimurium as compared to that in E. coli. Growth experiments using double mutants blocked in the de novo pathway to nicotinamide adenine dinucleotide (NAD) (nad) and in the pyridine nucleotide cycle (pnc) at either the pncA or pncB locus, or both, have provided evidence for the existence of an alternate recycling pathway in this organism. Mutants lacking this alternate cycle, pncC, have been isolated and mapped via cotransduction at 0 units. Utilization of exogenous NAD was examined through the use of [14C]carbonyl-labeled NAD and [14C]adenine-labeled NAD. The results of these experiments suggest that NAD is degraded to nicotinamide mononucleotide at the cell surface. A portion of this extracellular nicotinamide mononucleotide is then transported across the cell membrane by nicotinamide mononucleotide glycohydrolase and degraded to nicotinamide in the process. The remaining nicotinamide mononucleotide accumulates extracellularly and will support the growth of nadA pncB mutants which cannot utilize the nicotinamide resulting from the major pathway of NAD degradation. A model is presented for the utilization of exogenous NAD by S. typhimurium LT-2.

  3. β-Nicotinamide adenine dinucleotide acts at prejunctional adenosine A1 receptors to suppress inhibitory musculomotor neurotransmission in guinea pig colon and human jejunum

    Science.gov (United States)

    Wang, Guo-Du; Wang, Xi-Yu; Liu, Sumei; Xia, Yun; Zou, Fei; Qu, Meihua; Needleman, Bradley J.; Mikami, Dean J.

    2015-01-01

    Intracellular microelectrodes were used to record neurogenic inhibitory junction potentials in the intestinal circular muscle coat. Electrical field stimulation was used to stimulate intramural neurons and evoke contraction of the smooth musculature. Exposure to β-nicotinamide adenine dinucleotide (β-NAD) did not alter smooth muscle membrane potential in guinea pig colon or human jejunum. ATP, ADP, β-NAD, and adenosine, as well as the purinergic P2Y1 receptor antagonists MRS 2179 and MRS 2500 and the adenosine A1 receptor agonist 2-chloro-N6-cyclopentyladenosine, each suppressed inhibitory junction potentials in guinea pig and human preparations. β-NAD suppressed contractile force of twitch-like contractions evoked by electrical field stimulation in guinea pig and human preparations. P2Y1 receptor antagonists did not reverse this action. Stimulation of adenosine A1 receptors with 2-chloro-N6-cyclopentyladenosine suppressed the force of twitch contractions evoked by electrical field stimulation in like manner to the action of β-NAD. Blockade of adenosine A1 receptors with 8-cyclopentyl-1,3-dipropylxanthine suppressed the inhibitory action of β-NAD on the force of electrically evoked contractions. The results do not support an inhibitory neurotransmitter role for β-NAD at intestinal neuromuscular junctions. The data suggest that β-NAD is a ligand for the adenosine A1 receptor subtype expressed by neurons in the enteric nervous system. The influence of β-NAD on intestinal motility emerges from adenosine A1 receptor-mediated suppression of neurotransmitter release at inhibitory neuromuscular junctions. PMID:25813057

  4. Are Polyphosphates or Phosphate Esters Prebiotic Reagents?

    Science.gov (United States)

    Keefe, Anthony D.; Miller, Stanley L.

    1995-01-01

    It is widely held that there was a phosphate compound in prebiotic chemistry that played the role of adenosine triphosphate and that the first living organisms had ribose-phosphate in the backbone of their genetic material. However, there are no known efficient prebiotic synthesis of high-energy phosphates or phosphate esters. We review the occurrence of phosphates in nature, the efficiency of the volcanic synthesis of P4O10, the efficiency of polyphosphate synthesis by heating phosphate minerals under geological conditions, and the use of high-energy organic compounds such as cyanamide or hydrogen cyanide. These are shown to be inefficient processes especially when the hydrolysis of the polyphosphates is taken into account. For example, if a whole atmosphere of methane or carbon monoxide were converted to cyanide which somehow synthesized polyphosphates quantitatively, the polyphosphate concentration in the ocean would still have been insignificant. We also attempted to find more efficient high-energy polymerizing agents by spark discharge syntheses, but without success. There may still be undiscovered robust prebiotic syntheses of polyphosphates, or mechanisms for concentrating them, but we conclude that phosphate esters may not have been constituents of the first genetic material. Phosphoanhydrides are also unlikely as prebiotic energy sources.

  5. How do arbuscular mycorrhizal fungi handle phosphate? New insight into fine-tuning of phosphate metabolism.

    Science.gov (United States)

    Ezawa, Tatsuhiro; Saito, Katsuharu

    2018-04-27

    Contents Summary I. Introduction II. Foraging for phosphate III. Fine-tuning of phosphate homeostasis IV. The frontiers: phosphate translocation and export V. Conclusions and outlook Acknowledgements References SUMMARY: Arbuscular mycorrhizal fungi form symbiotic associations with most land plants and deliver mineral nutrients, in particular phosphate, to the host. Therefore, understanding the mechanisms of phosphate acquisition and delivery in the fungi is critical for full appreciation of the mutualism in this association. Here, we provide updates on physical, chemical, and biological strategies of the fungi for phosphate acquisition, including interactions with phosphate-solubilizing bacteria, and those on the regulatory mechanisms of phosphate homeostasis based on resurveys of published genome sequences and a transcriptome with reference to the latest findings in a model fungus. For the mechanisms underlying phosphate translocation and export to the host, which are major research frontiers in this field, not only recent advances but also testable hypotheses are proposed. Lastly, we briefly discuss applicability of the latest tools to gene silencing in the fungi, which will be breakthrough techniques for comprehensive understanding of the molecular basis of fungal phosphate metabolism. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

  6. Titrimetric determination of uranium in tributyl phosphate

    International Nuclear Information System (INIS)

    Sobkowska, A.

    1978-01-01

    The titrimetric method involving the reduction of U(VI) to uranium(IV) by iron(II) in phosphoric acid, selective oxidation of the excess of iron(II) and potentiometric titration with dichromate was directly used for the determination of uranium in tributyl phosphate mixtures. The procedure was applied to solutions containing more than 2 mg of uranium in the sample but the highest precision and accuracy were obtained in the range from 20 to 200 mg of uranium. Dibutyl phosphate and monobutyl phosphate as well as the other radiolysis products of TBP had no influence on the results of determinations. (author)

  7. Uranium and heavy metals in phosphate fertilizers

    International Nuclear Information System (INIS)

    Khater, A.E.M.

    2008-01-01

    Agricultural applications of chemical fertilizers are a worldwide practice. The specific activity of uranium-238 and heavy metals in phosphate fertilizers depends on the phosphate ore from which the fertilizer produced and on the chemical processing of the ore. Composite phosphate fertilizers samples where collected and the uranium-238 specific activity, in Bq/kg, and As, Cd, Cu, Pb, Se concentration, in ppm, were measured. The annual addition of these elements in soil due to fertilization were calculated and discussed. (author)(tk)

  8. Global radiological impact of the phosphate fertilizers

    International Nuclear Information System (INIS)

    Morales, Rudnei Karam; Alves, Rex Nazare

    1996-01-01

    About ninety percent of the products obtained in the phosphate industry are directly used in agriculture as fertilizers. The uranium, thorium and radium content in phosphate fertilizers pollute the soil, water and air, creating risks due to associated natural radiation. This work shows the concentration of radionuclides present in various products of the national and American phosphate fertilizers industry, and compared them with worldwide mean values. The radiological impact of the products on the environment is evaluated and suggestions are presented in order to minimize the risks due to radioactivity. (author)

  9. Serum phosphate is associated with aortic valve calcification in the Multi-ethnic Study of Atherosclerosis (MESA).

    Science.gov (United States)

    Linefsky, Jason P; O'Brien, Kevin D; Sachs, Michael; Katz, Ronit; Eng, John; Michos, Erin D; Budoff, Matthew J; de Boer, Ian; Kestenbaum, Bryan

    2014-04-01

    This study sought to investigate associations of phosphate metabolism biomarkers with aortic valve calcification (AVC). Calcific aortic valve disease (CAVD) is a common progressive condition that involves inflammatory and calcification mediators. Currently there are no effective medical treatments, but mineral metabolism pathways may be important in the development and progression of disease. We examined associations of phosphate metabolism biomarkers, including serum phosphate, urine phosphate, parathyroid hormone (PTH) and serum fibroblast growth factor (FGF)-23, with CT-assessed AVC at study baseline and in short-term follow-up in 6814 participants of the Multi-Ethnic Study of Atherosclerosis (MESA). At baseline, AVC prevalence was 13.2%. Higher serum phosphate levels were associated with significantly greater AVC prevalence (relative risk 1.3 per 1 mg/dL increment, 95% confidence incidence: 1.1 to 1.5, pAVC. Average follow-up CT evaluation was 2.4 years (range 0.9-4.9 years) with an AVC incidence of 4.1%. Overall, phosphate metabolism biomarkers were not associated with incident AVC except in the top FGF-23 quartile. Serum phosphate levels are significantly associated with AVC prevalence. Further study of phosphate metabolism as a modifiable risk factor for AVC is warranted. Published by Elsevier Ireland Ltd.

  10. Sphingosine 1-phosphate and cancer.

    Science.gov (United States)

    Pyne, Nigel J; El Buri, Ashref; Adams, David R; Pyne, Susan

    2017-09-15

    The bioactive lipid, sphingosine 1-phosphate (S1P) is produced by phosphorylation of sphingosine and this is catalysed by two sphingosine kinase isoforms (SK1 and SK2). Here we discuss structural functional aspects of SK1 (which is a dimeric quaternary enzyme) that relate to coordinated coupling of membrane association with phosphorylation of Ser225 in the 'so-called' R-loop, catalytic activity and protein-protein interactions (e.g. TRAF2, PP2A and G q ). S1P formed by SK1 at the plasma-membrane is released from cells via S1P transporters to act on S1P receptors to promote tumorigenesis. We discuss here an additional novel mechanism that can operate between cancer cells and fibroblasts and which involves the release of the S1P receptor, S1P 2 in exosomes from breast cancer cells that regulates ERK-1/2 signalling in fibroblasts. This novel mechanism of signalling might provide an explanation for the role of S1P 2 in promoting metastasis of cancer cells and which is dependent on the micro-environmental niche. Copyright © 2017. Published by Elsevier Ltd.

  11. Radiation doses from phosphate fertilizers

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The activity concentrations determined of 226 Ra, 232 Th and 40 K in nCi/kg P 2 O 5 for the five most important kinds of fertilizer as well as their percent share in the economy year 1973/74 in the FRG are compiled in a table. From these values, the consumption of 0.917 million tons P 2 O 5 and from an average annual fertilizer coverage of 68.3 kg/ha, one can calculate a distribution of 32 Ci 226 Ra, 1 Ci 232 Th and 543 Ci 40 K over the total agriculturally used area, in other words, a deposit of 2.4 μCi 226 Ra, 0.07 μCi 232 Th and 40.5 μCi 40 K per ha. Taking a pessimistic view, an external radiation exposure of 0.11 mrad/a was calculated for gonads and bone marrow. If the total accumulation of 226 Ra (38% of the radiation exposure) from phosphate fertilizers from the ground during the last 80 years is assumed, then there is an exposure of 1.7 mrad/a for individual members of the population and 2.0 mrad/a for those occupied in agriculture. (HP/LH) [de

  12. Natural radioactivity in phosphate fertilizers

    International Nuclear Information System (INIS)

    Arndt, J.; Aurand, K.; Ruehle, H.; Schmier, H.; Wolter, R.

    1974-12-01

    The activity concentrations determined of 226 Ra, 232 Th and 40 K in nCi/kg P 2 O 5 for the five most important kinds of fertilizer as well as their percent share in the economy year 1973/74 in the FRG are compiled in a table. From these values, the consumption of 0.917 million tons P 2 O 5 and from an average annual fertilizer covering of 68.3 kg/ha, one can calculate a distribution of 32 Ci 226 Ra, 1 Ci 232 Th and 543 Ci 40 K over the total agriculturally used area, in other words a deposit of 2.4 μCi 226 Ra, 0.07 μCi 232 Th and 40.5 μCi 40 K per ha. Taking a pessimistic view, an external radiation exposure of 0.11 mrad/a was calculated for gonads and bone marrow. If the total accumulation of 226 Ra (38% of the radiation exposure) from phosphate fertilizers from the ground during the last 80 years is assumed, then there is an exposure of 1.7 mrad/a for individual members of the population and 2.0 mrad/a for those occupied in agriculture. (HP/LH) [de

  13. Hemodialysis for near-fatal sodium phosphate toxicity in a child receiving sodium phosphate enemas.

    Science.gov (United States)

    Becknell, Brian; Smoyer, William E; O'Brien, Nicole F

    2014-11-01

    This study aimed to demonstrate the importance of considering hemodialysis as a treatment option in the management of sodium phosphate toxicity. This is a case report of a 4-year-old who presented to the emergency department with shock, decreased mental status, seizures, and tetany due to sodium phosphate toxicity from sodium phosphate enemas. Traditional management of hyperphosphatemia with aggressive hydration and diuretics was insufficient to reverse the hemodynamic and neurological abnormalities in this child. This is the first report of the use of hemodialysis in a child without preexisting renal failure for the successful management of near-fatal sodium phosphate toxicity. Hemodialysis can safely be used as an adjunctive therapy in sodium phosphate toxicity to rapidly reduce serum phosphate levels and increase serum calcium levels in children not responding to conventional management.

  14. Performance of pineapple slips inoculated with diazotrophic phosphate-solubilizing bacteria and rock phosphate

    OpenAIRE

    Lílian Estrela Borges Baldotto; Marihus Altoé Baldotto; Fábio Lopes Olivares; Adriane Nunes de Souza

    2014-01-01

    Besides fixing N2, some diazotrophic bacteria or diazotrophs, also synthesize organic acids and are able to solubilize rock phosphates, increasing the availability of P for plants. The application of these bacteria to pineapple leaf axils in combination with rock phosphate could increase N and P availability for the crop, due to the bacterial activity of biological nitrogen fixation and phosphate solubilization. The objectives of this study were: (i) to select and characterize diazotrophs abl...

  15. Uranium recovery from phosphate rocks concentrated

    International Nuclear Information System (INIS)

    Azevedo, M.F. de.

    1986-01-01

    The reserves, geological data, chemical data and technical flowsheet from COPEBRAS and Goiasfertil ores are described, including the process of mining ore concentration. Samples of Goiasfertil ores are analysed by gravimetric analysis, for phosphate, and spectrofluorimetry for uranium. (author)

  16. Hanford phosphate precipitation filtration process evaluation

    International Nuclear Information System (INIS)

    Walker, B.W.; McCabe, D.J.

    1997-01-01

    The purpose of this filter study was to evaluate cross-flow filtration as effective solid-liquid separation technology for treating Hanford wastes, outline operating conditions for equipment, examine the expected filter flow rates, and determine proper cleaning. A proposed Hanford waste pre-treatment process uses sodium hydroxide at high temperature to remove aluminum from sludge. This process also dissolves phosphates. Upon cooling to 40 degrees centigrade the phosphates form a Na7(PO4)2F9H2O precipitate which must be removed prior to further treatment. Filter studies were conducted with a phosphate slurry simulant to evaluate whether 0.5 micron cross-flow sintered metal Mott filters can separate the phosphate precipitate from the wash solutions. The simulant was recirculated through the filters at room temperature and filtration performance data was collected

  17. short communication agronomic effectiveness of novel phosphate

    African Journals Online (AJOL)

    igneous Dorowa (Zimbabwe) phosphate rock was investigated in a greenhouse ... are higher than the levels considered desirable for acidulation was selected based on proportions ... The analysis for dry matter yield of and P uptake by maize ...

  18. Phosphate coating on stainless steel 304 sensitized

    International Nuclear Information System (INIS)

    Cruz V, J. P.; Vite T, J.; Castillo S, M.; Vite T, M.

    2009-01-01

    The stainless steel 304 can be sensitized when welding processes are applied, that causes the precipitation of chromium carbide in the grain limits, being promoted in this way the formation of galvanic cells and consequently the corrosion process. Using a phosphate coating is possible to retard the physiochemical damages that can to happen in the corrosion process. The stainless steel 304 substrate sensitized it is phosphate to base of Zn-Mn, in a immersion cell very hot. During the process was considered optimization values, for the characterization equipment of X-rays diffraction and scanning electron microscopy was used. The XRD technique confirmed the presence of the phases of manganese phosphate, zinc phosphate, as well as the phase of the stainless steel 304. When increasing the temperature from 60 to 90 C in the immersion process a homogeneous coating is obtained. (Author)

  19. Issues of natural radioactivity in phosphates

    International Nuclear Information System (INIS)

    Schnug, E.; Haneklaus, S.; Schnier, C.; Scholten, L.C.

    1996-01-01

    The fertilization of phosphorus (P) fertilizers is essential in agricultural production, but phosphates contain in dependence on their origin different amounts of trace elements. The problem of cadmium (Cd) loads and other heavy metals is well known. However, only a limited number of investigations examined the contamination of phosphates with the two heaviest metals, uranium (U) and thorium (Th), which are radioactive. Also potassium (K) is lightly radioactive. Measurements are done n the radioactivity content of phosphates, P fertilizers and soils. The radiation doses to workers and public as well as possible contamination of soils from phosphate rock or fertilizer caused by these elements or their daughter products is of interest with regard to radiation protection. The use of P fertilizers is necessary for a sustainable agriculture, but it involves radioactive contamination of soils. The consequences of the use of P fertilizers is discussed, also with regard to existing and proposed legislation. 11 refs., 2 figs., 7 tabs

  20. Geochemistry and mineralogy of Ogun phosphate rock

    African Journals Online (AJOL)

    user

    m deep) within the same location. The pellets ... diffracted rays are collected by a detector and the information relayed to a ... Ogun phosphate deposits were formed in shallow marine ... process thus confirming the earlier work done by Jones.

  1. Rock phosphate solubilization by the ectomycorrhizal fungus ...

    African Journals Online (AJOL)

    SAM

    2014-06-18

    Jun 18, 2014 ... phosphate solubilization is accompanied by acid production. Thus, the evidence ..... of organic acids. (Khan et al., 2010) such as acetate, lactate, oxalate, ... (2014) also observed that oxalic acid was secreted by L. fraterna to ...

  2. Thermal stability of phosphate coatings on steel

    Czech Academy of Sciences Publication Activity Database

    Pokorný, P.; Szelag, P.; Novák, M.; Mastný, L.; Brožek, Vlastimil

    2015-01-01

    Roč. 54, č. 3 (2015), s. 489-492 ISSN 0543-5846 Institutional support: RVO:61389021 Keywords : Steel * phosphates * coatings * structure Subject RIV: CA - Inorganic Chemistry Impact factor: 0.959, year: 2014

  3. Corrosion inhibition by lithium zinc phosphate pigment

    International Nuclear Information System (INIS)

    Alibakhshi, E.; Ghasemi, E.; Mahdavian, M.

    2013-01-01

    Highlights: •Synthesis of lithium zinc phosphate (LZP) by chemical co-precipitation method. •Corrosion inhibition activity of pigments compare with zinc phosphate (ZP). •LZP showed superior corrosion inhibition effect in EIS measurements. •Evaluation of adhesion strength and dispersion stability. -- Abstract: Lithium zinc phosphate (LZP) has been synthesized through a co-precipitation process and characterized by XRD and IR spectroscopy. The inhibitive performances of this pigment for corrosion of mild steel have been discussed in comparison with the zinc phosphate (ZP) in the pigment extract solution by means of EIS and in the epoxy coating by means of salt spray. The EIS and salt spray results revealed the superior corrosion inhibitive effect of LZP compared to ZP. Moreover, adhesion strength and dispersion stability of the pigmented epoxy coating showed the advantage of LZP compared to ZP

  4. Synthesis and characterization of porous calcium phosphate

    International Nuclear Information System (INIS)

    Granados C, F.; Serrano G, J.; Bonifacio M, J.

    2007-01-01

    The porous calcium phosphate was prepared by the continuous precipitation method using Ca(NO 3 ) 2 .4H 2 O and NH 4 H 2 PO 4 salts. The synthesized material was structurally and superficially characterized using the XRD, BET, IR TGA and SEM techniques. The obtained inorganic material was identified as calcium phosphate that presents a great specific area for what can be efficiently used as adsorbent material for adsorption studies in the radioactive wastes treatment present in aqueous solution. (Author)

  5. Removal of organic wastes containing tributyl phosphate

    International Nuclear Information System (INIS)

    Drobnik, S.

    TBP in dodecane and kerosene is one of the waste solutions from the reprocessing of spent nuclear fuels by the Purex process. The following methods were investigated for removing the organic solvents: adsorption on suitable solids, extraction, reaction with neutral salts, and saponification with acids or alkalis. Results showed that the best method of TBP removal is saponification with alkali hydroxides, either with dibutyl phosphate or with ortho-phosphate

  6. Kinetics of strontium sorption in calcium phosphate

    International Nuclear Information System (INIS)

    Bacic, S.; Komarov, V.F.; Vukovic, Z.

    1989-01-01

    Kinetics of strontium sorption by highly dispersed solids: tricalcium phosphate (Ca 3 (PO 4 ) 2 , TCP) and hydroxyapatite (Ca 5 (PO 4 ) 3 )H, HAP) were investigated. Analysis of sorption data was made taking into consideration composition and morphology of ultra micro particles. Conclusion is that the isomorphous strontium impurity is structurally sensitive element for calcium phosphate. It was determined that the beginning of strontium desorption corresponds to the beginning of transformation of the TCP - HAP (author)

  7. Phosphate transporter mediated lipid accumulation in Saccharomyces cerevisiae under phosphate starvation conditions.

    Science.gov (United States)

    James, Antoni W; Nachiappan, Vasanthi

    2014-01-01

    In the current study, when phosphate transporters pho88 and pho86 were knocked out they resulted in significant accumulation (84% and 43%) of triacylglycerol (TAG) during phosphate starvation. However in the presence of phosphate, TAG accumulation was only around 45% in both pho88 and pho86 mutant cells. These observations were confirmed by radio-labeling, fluorescent microscope and RT-PCR studies. The TAG synthesizing genes encoding for acyltransferases namely LRO1 and DGA1 were up regulated. This is the first report for accumulation of TAG in pho88Δ and pho86Δ cells under phosphate starvation conditions. Copyright © 2013. Published by Elsevier Ltd.

  8. Phosphate rock costs, prices and resources interaction.

    Science.gov (United States)

    Mew, M C

    2016-01-15

    This article gives the author's views and opinions as someone who has spent his working life analyzing the international phosphate sector as an independent consultant. His career spanned two price hike events in the mid-1970's and in 2008, both of which sparked considerable popular and academic interest concerning adequacy of phosphate rock resources, the impact of rising mining costs and the ability of mankind to feed future populations. An analysis of phosphate rock production costs derived from two major industry studies performed in 1983 and 2013 shows that in nominal terms, global average cash production costs increased by 27% to $38 per tonne fob mine in the 30 year period. In real terms, the global average cost of production has fallen. Despite the lack of upward pressure from increasing costs, phosphate rock market prices have shown two major spikes in the 30 years to 2013, with periods of less volatility in between. These price spike events can be seen to be related to the escalating investment cost required by new mine capacity, and as such can be expected to be repeated in future. As such, phosphate rock price volatility is likely to have more impact on food prices than rising phosphate rock production costs. However, as mining costs rise, recycling of P will also become increasingly driven by economics rather than legislation. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Sphingosine 1-Phosphate and Atherosclerosis

    Science.gov (United States)

    Yatomi, Yutaka

    2018-01-01

    Sphingosine 1-phosphate (S1P) is a potent lipid mediator that works on five kinds of S1P receptors located on the cell membrane. In the circulation, S1P is distributed to HDL, followed by albumin. Since S1P and HDL share several bioactivities, S1P is believed to be responsible for the pleiotropic effects of HDL. Plasma S1P levels are reportedly lower in subjects with coronary artery disease, suggesting that S1P might be deeply involved in the pathogenesis of atherosclerosis. In basic experiments, however, S1P appears to possess both pro-atherosclerotic and anti-atherosclerotic properties; for example, S1P possesses anti-apoptosis, anti-inflammation, and vaso-relaxation properties and maintains the barrier function of endothelial cells, while S1P also promotes the egress and activation of lymphocytes and exhibits pro-thrombotic properties. Recently, the mechanism for the biased distribution of S1P on HDL has been elucidated; apolipoprotein M (apoM) carries S1P on HDL. ApoM is also a modulator of S1P, and the metabolism of apoM-containing lipoproteins largely affects the plasma S1P level. Moreover, apoM modulates the biological properties of S1P. S1P bound to albumin exerts both beneficial and harmful effects in the pathogenesis of atherosclerosis, while S1P bound to apoM strengthens anti-atherosclerotic properties and might weaken the pro-atherosclerotic properties of S1P. Although the detailed mechanisms remain to be elucidated, apoM and S1P might be novel targets for the alleviation of atherosclerotic diseases in the future. PMID:28724841

  10. Role of Phosphate Transport System Component PstB1 in Phosphate Internalization by Nostoc punctiforme.

    Science.gov (United States)

    Hudek, L; Premachandra, D; Webster, W A J; Bräu, L

    2016-11-01

    In bacteria, limited phosphate availability promotes the synthesis of active uptake systems, such as the Pst phosphate transport system. To understand the mechanisms that facilitate phosphate accumulation in the cyanobacterium Nostoc punctiforme, phosphate transport systems were identified, revealing a redundancy of Pst phosphate uptake systems that exists across three distinct operons. Four separate PstB system components were identified. pstB1 was determined to be a suitable target for creating phenotypic mutations that could result in the accumulation of excessive levels of phosphate through its overexpression or in a reduction of the capacity to accumulate phosphate through its deletion. Using quantitative real-time PCR (qPCR), it was determined that pstB1 mRNA levels increased significantly over 64 h in cells cultured in 0 mM added phosphate and decreased significantly in cells exposed to high (12.8 mM) phosphate concentrations compared to the level in cells cultured under normal (0.8 mM) conditions. Possible compensation for the loss of PstB1 was observed when pstB2, pstB3, and pstB4 mRNA levels increased, particularly in cells starved of phosphate. The overexpression of pstB1 increased phosphate uptake by N. punctiforme and was shown to functionally complement the loss of PstB in E. coli PstB knockout (PstB - ) mutants. The knockout of pstB1 in N. punctiforme did not have a significant effect on cellular phosphate accumulation or growth for the most part, which is attributed to the compensation for the loss of PstB1 by alterations in the pstB2, pstB3, and pstB4 mRNA levels. This study provides novel in vivo evidence that PstB1 plays a functional role in phosphate uptake in N. punctiforme IMPORTANCE: Cyanobacteria have been evolving over 3.5 billion years and have become highly adept at growing under limiting nutrient levels. Phosphate is crucial for the survival and prosperity of all organisms. In bacteria, limited phosphate availability promotes the

  11. Translocation of metal phosphate via the phosphate inorganic transport system of Escherichia coli

    NARCIS (Netherlands)

    van Veen, H.W; Abee, T.; Kortstee, G.J J; Konings, W.N; Zehnder, A.J B

    1994-01-01

    P-i transport via the phosphate inorganic transport system (Pit) of Escherichia coil was studied in natural and artificial membranes. P-i uptake via Pit is dependent on the presence of divalent cations, like Mg2+, Ca2+, Co2+, or Mn2+, which form a soluble, neutral metal phosphate (MeHPO(4)) complex.

  12. Isolation and screening phosphate solubilizers from composts as biofertilizer

    International Nuclear Information System (INIS)

    Phua Choo Kwai Hoe; Khairuddin Abdul Rahim; Latiffah Norddin; Abdul Razak Ruslan

    2006-01-01

    Phosphate solubilizers are miroorganisms that able to solubilize insoluble inorganic phosphate compounds or hydrolyze organic phosphate to inorganic P. Therefore make the P to be available for plant and consequently enhance plant growth and yield. Recently, phosphate solubilizing microorganisms has been shown to play an important role in the biofertilizer industry. Fifty-one bacterial were isolated from eleven composts. Most of the phosphate solubilizers were isolated from natural farming composted compost and normal composting compost. This shows that both of these composts are more suitable to use for phosphate solubilizer isolation compare commercial composts. Fourteen of the isolates were found to be phosphate solubilizers. These isolates produced a clear zone on the phosphate agar plates, showing their potential as biofertilizer. AP3 was significantly produced the largest clear zone compared with other isolates. This indicates that isolate AP 3 could be a good phosphate solubilizer. Thus, their effectiveness in the greenhouse and field should be evaluated. (Author)

  13. [Phosphate solubilization of Aureobasidium pullulan F4 and its mechanism].

    Science.gov (United States)

    Wang, Dan; Zhan, Jing; Sun, Qing-Ye

    2014-07-01

    The Aureobasidium pullulans F4 was isolated from the rhizosphere of Hippochaete ramosissimum in Tongguanshan mine wasteland in Tongling City, Anhui Province. Liquid culture was conducted with four kinds of phosphorus sources, calcium phosphate, aluminum phosphate, ferric phosphate and rock phosphate to determine the pH, dissolved phosphorus, phosphorus in the bacteria and organic acid in the solution. The results showed that the phosphate solubilization by A. pullulans F4 varied with phosphorus sources, which decreased in order of aluminum phosphate > ferric phosphate, calcium phosphate > rock phosphate. The amounts of dissolved phosphorus in the different treatments were all higher than 200 mg x L(-1). The pH of the medium dropped immediately in 48 h, and the aluminum phosphate and ferric phosphate treatments showed a greater decrease in pH than the calcium phosphate and rock phosphate treatments. The organic acid synthesized by A. pullulans F4 included oxalic acid, citric acid and tartaric acid, and oxalic acid, among which oxalic acid was the dominated component. The phosphate dissolving capacity of A. pullulans F4 showed no significant correlation with organic acid, but significantly correlated with the pH. The available phosphorus was significantly improved with the combined application of A. pullulans F4 and glucose, suggesting A. pullulans F4 was a potent candidate for remediation of copper mine wastelands.

  14. Removal mechanism of phosphate from aqueous solution by fly ash.

    Science.gov (United States)

    Lu, S G; Bai, S Q; Zhu, L; Shan, H D

    2009-01-15

    This work studied the effectiveness of fly ash in removing phosphate from aqueous solution and its related removal mechanism. The adsorption and precipitation of phosphate by fly ash were investigated separately in order to evaluate their role in the removal of phosphate. Results showed that the removal of phosphate by fly ash was rapid. The removal percentage of phosphate in the first 5min reached 68-96% of the maximum removal of phosphate by fly ash. The removal processes of phosphate by fly ash included a fast and large removal representing precipitation, then a slower and longer removal due to adsorption. The adsorption of phosphate on fly ash could be described well by Freundlich isotherm equation. The pH and Ca2+ concentration of fly ash suspension were decreased with the addition of phosphate, which suggests that calcium phosphate precipitation is a major mechanism of the phosphate removal. Comparison of the relative contribution of the adsorption and precipitation to the total removal of phosphate by fly ash showed that the adsorption accounted for 30-34% of the total removal of phosphate, depending on the content of CaO in fly ash. XRD patterns of the fly ash before and after phosphate adsorption revealed that phosphate salt (CaHPO4 x 2H2O) was formed in the adsorption process. Therefore, the removal of phosphate by fly ash can be attributed to the formation of phosphate precipitation as a brushite and the adsorption on hydroxylated oxides. The results suggested that the use of fly ash could be a promising solution to the removal of phosphate in the wastewater treatment and pollution control.

  15. Structural basis for phosphatidylinositol-phosphate biosynthesis

    Science.gov (United States)

    Clarke, Oliver B.; Tomasek, David; Jorge, Carla D.; Dufrisne, Meagan Belcher; Kim, Minah; Banerjee, Surajit; Rajashankar, Kanagalaghatta R.; Shapiro, Lawrence; Hendrickson, Wayne A.; Santos, Helena; Mancia, Filippo

    2015-10-01

    Phosphatidylinositol is critical for intracellular signalling and anchoring of carbohydrates and proteins to outer cellular membranes. The defining step in phosphatidylinositol biosynthesis is catalysed by CDP-alcohol phosphotransferases, transmembrane enzymes that use CDP-diacylglycerol as donor substrate for this reaction, and either inositol in eukaryotes or inositol phosphate in prokaryotes as the acceptor alcohol. Here we report the structures of a related enzyme, the phosphatidylinositol-phosphate synthase from Renibacterium salmoninarum, with and without bound CDP-diacylglycerol to 3.6 and 2.5 Å resolution, respectively. These structures reveal the location of the acceptor site, and the molecular determinants of substrate specificity and catalysis. Functional characterization of the 40%-identical ortholog from Mycobacterium tuberculosis, a potential target for the development of novel anti-tuberculosis drugs, supports the proposed mechanism of substrate binding and catalysis. This work therefore provides a structural and functional framework to understand the mechanism of phosphatidylinositol-phosphate biosynthesis.

  16. Radionuclide containment in soil by phosphate treatment

    International Nuclear Information System (INIS)

    Lee, S.Y.; Francis, C.W.; Timpson, M.E.; Elless, M.P.

    1995-01-01

    Radionuclide transport from a contaminant source to groundwater and surface water is a common problem faced by most US Department of Energy (DOE) facilities. Containment of the radionuclide plume, including strontium-90 and uranium, is possible using phosphate treatment as a chemical stabilizer. Such a chemical process occurs in soils under natural environmental conditions. Therefore, the concept of phosphate amendment for radiostrontium and uranium immobilization is already a proven principle. In this presentation, results of bench-scale experiments and the concept of a field-scale demonstration are discussed. The phosphate treatment is possible at the source or near the advancing contaminant plume. Cleanup is still the ideal concept; however, containment through stabilization is a more practical and costeffective concept that should be examined by DOE Environmental Restoration programs

  17. Phosphate Phosphors for Solid-State Lighting

    CERN Document Server

    Shinde, Kartik N; Swart, H C; Park, Kyeongsoon

    2012-01-01

    The idea for this book arose out of the realization that, although excellent surveys and a phosphor handbook are available, there is no single source covering the area of phosphate based phosphors especially for lamp industry. Moreover, as this field gets only limited attention in most general books on luminescence, there is a clear need for a book in which attention is specifically directed toward this rapidly growing field of solid state lighting and its many applications. This book is aimed at providing a sound introduction to the synthesis and optical characterization of phosphate phosphor for undergraduate and graduate students as well as teachers and researchers. The book provides guidance through the multidisciplinary field of solid state lighting specially phosphate phosphors for beginners, scientists and engineers from universities, research organizations, and especially industry. In order to make it useful for a wide audience, both fundamentals and applications are discussed, together.

  18. Phosphate Favors the Biosynthesis of CdS Quantum Dots in Acidithiobacillus thiooxidans ATCC 19703 by Improving Metal Uptake and Tolerance

    Directory of Open Access Journals (Sweden)

    Giovanni Ulloa

    2018-02-01

    Full Text Available Recently, we reported the production of Cadmium sulfide (CdS fluorescent semiconductor nanoparticles (quantum dots, QDs by acidophilic bacteria of the Acidithiobacillus genus. Here, we report that the addition of inorganic phosphate to Acidithiobacillus thiooxidans ATCC 19703 cultures favors the biosynthesis of CdS QDs at acidic conditions (pH 3.5. The effect of pH, phosphate and cadmium concentrations on QDs biosynthesis was studied by using Response Surface Methodology (RSM, a multivariate technique for analytical optimization scarcely used in microbiological studies to date. To address how phosphate affects intracellular biosynthesis of CdS QDs, the effect of inorganic phosphate on bacterial cadmium-uptake was evaluated. By measuring intracellular levels of cadmium we determined that phosphate influences the capacity of cells to incorporate this metal. A relation between cadmium tolerance and phosphate concentrations was also determined, suggesting that phosphate participates in the adaptation of bacteria to toxic levels of this metal. In addition, QDs-biosynthesis was also favored by the degradation of intracellular polyphosphates. Altogether, our results indicate that phosphate contributes to A. thiooxidans CdS QDs biosynthesis by influencing cadmium uptake and cadmium tolerance. These QDs may also be acting as a nucleation point for QDs formation at acidic pH. This is the first study reporting the effect of phosphates on QDs biosynthesis and describes a new cadmium-response pathway present in A. thiooxidans and most probably in other bacterial species.

  19. Phosphate Favors the Biosynthesis of CdS Quantum Dots in Acidithiobacillus thiooxidans ATCC 19703 by Improving Metal Uptake and Tolerance

    Science.gov (United States)

    Ulloa, Giovanni; Quezada, Carolina P.; Araneda, Mabel; Escobar, Blanca; Fuentes, Edwar; Álvarez, Sergio A.; Castro, Matías; Bruna, Nicolás; Espinoza-González, Rodrigo; Bravo, Denisse; Pérez-Donoso, José M.

    2018-01-01

    Recently, we reported the production of Cadmium sulfide (CdS) fluorescent semiconductor nanoparticles (quantum dots, QDs) by acidophilic bacteria of the Acidithiobacillus genus. Here, we report that the addition of inorganic phosphate to Acidithiobacillus thiooxidans ATCC 19703 cultures favors the biosynthesis of CdS QDs at acidic conditions (pH 3.5). The effect of pH, phosphate and cadmium concentrations on QDs biosynthesis was studied by using Response Surface Methodology (RSM), a multivariate technique for analytical optimization scarcely used in microbiological studies to date. To address how phosphate affects intracellular biosynthesis of CdS QDs, the effect of inorganic phosphate on bacterial cadmium-uptake was evaluated. By measuring intracellular levels of cadmium we determined that phosphate influences the capacity of cells to incorporate this metal. A relation between cadmium tolerance and phosphate concentrations was also determined, suggesting that phosphate participates in the adaptation of bacteria to toxic levels of this metal. In addition, QDs-biosynthesis was also favored by the degradation of intracellular polyphosphates. Altogether, our results indicate that phosphate contributes to A. thiooxidans CdS QDs biosynthesis by influencing cadmium uptake and cadmium tolerance. These QDs may also be acting as a nucleation point for QDs formation at acidic pH. This is the first study reporting the effect of phosphates on QDs biosynthesis and describes a new cadmium-response pathway present in A. thiooxidans and most probably in other bacterial species. PMID:29515535

  20. Monte Carlo Simulations of Phosphate Polyhedron Connectivity in Glasses

    Energy Technology Data Exchange (ETDEWEB)

    ALAM,TODD M.

    1999-12-21

    Monte Carlo simulations of phosphate tetrahedron connectivity distributions in alkali and alkaline earth phosphate glasses are reported. By utilizing a discrete bond model, the distribution of next-nearest neighbor connectivities between phosphate polyhedron for random, alternating and clustering bonding scenarios was evaluated as a function of the relative bond energy difference. The simulated distributions are compared to experimentally observed connectivities reported for solid-state two-dimensional exchange and double-quantum NMR experiments of phosphate glasses. These Monte Carlo simulations demonstrate that the polyhedron connectivity is best described by a random distribution in lithium phosphate and calcium phosphate glasses.

  1. Method of decomposing treatment for radioactive organic phosphate wastes

    International Nuclear Information System (INIS)

    Uki, Kazuo; Ichihashi, Toshio; Hasegawa, Akira; Sato, Tatsuaki

    1985-01-01

    Purpose: To decompose the organic phosphoric-acid ester wastes containing radioactive material, which is produced from spent fuel reprocessing facilities, into inorganic materials using a simple device, under moderate conditions and at high decomposing ratio. Method: Radioactive organic phosphate wates are oxidatively decomposed by H 2 O 2 in an aqueous phosphoric-acid solution of metal phosphate salts. Copper phosphates are used as the metal phosphate salts and the decomposed solution of the radioactive organic phosphate wastes is used as the aqueous solution of the copper phosphate. The temperature used for the oxidizing decomposition ranges from 80 to 100 0 C. (Ikeda, J.)

  2. Synthesis of β-tricalcium phosphate.

    Science.gov (United States)

    Chaair, H; Labjar, H; Britel, O

    2017-09-01

    Ceramics play a key role in several biomedical applications. One of them is bone grafting, which is used for treating bone defects caused by injuries or osteoporosis. Calcium-phosphate based ceramic are preferred as bone graft biomaterials in hard tissue surgery because their chemical composition is close to the composition of human bone. They also have a marked bioresorbability and bioactivity. In this work, we have developed methods for synthesis of β-tricalcium phosphate apatite (β-TCP). These products were characterized by different techniques such as X-ray diffraction, infrared spectroscopy, scanning electron microscopy and chemical analysis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Potentially Prebiotic Syntheses of Condensed Phosphates

    Science.gov (United States)

    Keefe, Anthony D.; Miller, Stanley L.

    1996-01-01

    In view of the importance of a prebiotic source of high energy phosphates, we have investigated a number of potentially prebiotic processes to produce condensed phosphates from orthophosphate and cyclic trimetaphosphate from tripolyphosphate. The reagents investigated include polymerizing nitriles, acid anhydrides, lactones, hexamethylene tetramine and carbon suboxide. A number of these processes give substantial yields of pyrophosphate from orthophosphate and trimetaphosphate from tripolyphosphate. Although these reactions may have been applicable in local areas, they are not sufficiently robust to have been of importance in the prebiotic open ocean.

  4. Automated back titration method to measure phosphate

    International Nuclear Information System (INIS)

    Comer, J.; Tehrani, M.; Avdeef, A.; Ross, J. Jr.

    1987-01-01

    Phosphate was measured in soda drinks and as an additive in flour, by a back titration method in which phosphate was precipitated with lanthanum, and the excess lanthanum was titrated with fluoride. All measurements were performed using the Orion fluoride electrode and the Orion 960 Autochemistry System. In most commercial automatic titrators, the inflection point of the titration curve, calculated from the first derivative of the curve, is used to find the equivalence polar of the titration. The inflection technique is compared with a technique based on Gran functions, which uses data collected after the end point and predicts the equivalence point accordingly

  5. Calcium phosphate ceramics in drug delivery

    Science.gov (United States)

    Bose, Susmita; Tarafder, Solaiman; Edgington, Joe; Bandyopadhyay, Amit

    2011-04-01

    Calcium phosphate (CaP) particulates, cements and scaffolds have attracted significant interest as drug delivery vehicles. CaP systems, including both hydroxyapaptite and tricalcium phosphates, possess variable stoichiometry, functionality and dissolution properties which make them suitable for cellular delivery. Their chemical similarity to bone and thus biocompatibility, as well as variable surface charge density contribute to their controlled release properties. Among specific research areas, nanoparticle size, morphology, surface area due to porosity, and chemistry controlled release kinetics are the most active. This article discusses CaP systems in their particulate, cements, and scaffold forms for drug, protein, and growth factor delivery toward orthopedic and dental applications.

  6. Performance of pineapple slips inoculated with diazotrophic phosphate-solubilizing bacteria and rock phosphate

    Directory of Open Access Journals (Sweden)

    Lílian Estrela Borges Baldotto

    2014-06-01

    Full Text Available Besides fixing N2, some diazotrophic bacteria or diazotrophs, also synthesize organic acids and are able to solubilize rock phosphates, increasing the availability of P for plants. The application of these bacteria to pineapple leaf axils in combination with rock phosphate could increase N and P availability for the crop, due to the bacterial activity of biological nitrogen fixation and phosphate solubilization. The objectives of this study were: (i to select and characterize diazotrophs able to solubilize phosphates in vitro and (ii evaluate the initial performance of the pineapple cultivars Imperial and Pérola in response to inoculation with selected bacteria in combination with rock phosphate. The experiments were conducted at Universidade Estadual do Norte Fluminense Darcy Ribeiro, in 2009. In the treatments with bacteria the leaf contents of N, P and K were higher than those of the controls, followed by an increase in plant growth. These results indicate that the combined application of diazotrophic phosphate-solubilizing bacteria Burkholderia together with Araxá rock phosphate can be used to improve the initial performance of pineapple slips.

  7. D-Ribulose 5-Phosphate 3-Epimerase: Functional and Structural Relationships to Members of the Ribulose-Phosphate Binding (beta/alpha)8-Barrel Superfamily

    International Nuclear Information System (INIS)

    Akana, J.; Federov, A.; Federov, E.; Novak, W.; Babbitt, P.; Almo, S.; Gerlt, J.

    2006-01-01

    The 'ribulose phosphate binding' superfamily defined by the Structural Classification of Proteins (SCOP) database is considered the result of divergent evolution from a common (β/α) 8 -barrel ancestor. The superfamily includes D-ribulose 5-phosphate 3-epimerase (RPE), orotidine 5'-monophosphate decarboxylase (OMPDC), and 3-keto-L-gulonate 6-phosphate decarboxylase (KGPDC), members of the OMPDC suprafamily, as well as enzymes involved in histidine and tryptophan biosynthesis that utilize phosphorylated metabolites as substrates. We now report studies of the functional and structural relationships of RPE to the members of the superfamily. As suggested by the results of crystallographic studies of the RPEs from rice and Plasmodium falciparum, the RPE from Streptococcus pyogenes is activated by Zn 2+ which binds with a stoichiometry of one ion per polypeptide. Although wild type RPE has a high affinity for Zn 2+ and inactive apoenzyme cannot be prepared, the affinity for Zn 2+ is decreased by alanine substitutions for the two histidine residues that coordinate the Zn 2+ ion (H34A and H67A); these mutant proteins can be prepared in an inactive, metal-free form and activated by exogenous Zn 2+ . The crystal structure of the RPE was solved at 1.8 Angstroms resolution in the presence of D-xylitol 5-phosphate, an inert analogue of the D-xylulose 5-phosphate substrate. This structure suggests that the 2,3-enediolate intermediate in the 1,1-proton transfer reaction is stabilized by bidentate coordination to the Zn 2+ that also is liganded to His 34, Asp 36, His 67, and Asp 176; the carboxylate groups of the Asp residues are positioned also to function as the acid/base catalysts. Although the conformation of the bound analogue resembles those of ligands bound in the active sites of OMPDC and KGPDC, the identities of the active site residues that coordinate the essential Zn 2+ and participate as acid/base catalysts are not conserved. We conclude that only the phosphate

  8. Formulation of single super phosphate fertilizer from rock phosphate of Hazara, Pakistan

    Directory of Open Access Journals (Sweden)

    Matiullah Khan

    2012-05-01

    Full Text Available Phosphorus deficiency is wide spread in soils of Pakistan. It is imperative to explore the potential and economics of indigenous Hazara rock phosphate for preparation of single super phosphate fertilizer. For the subject study rock phosphate was collected from Hazara area ground at 160 mesh level with 26% total P2O5 content for manual preparation of single super phosphate fertilizer. The rock phosphate was treated with various concentrations of sulfuric acid (98.9%, diluted or pure in the field. The treatments comprised of 20 and 35% pure acid and diluted with acid-water ratios of 1:5, 1:2, 1:1 and 2:1 v/v for acidulation at the rate of 60 liters 100 kg-1 rock phosphate. The amount was prior calculated in the laboratory for complete wetting of rock phosphate. A quantity of 150 kg rock phosphate was taken as treatment. The respective amount of acid was applied with the spray pump of stainless steel or poured with bucket. After proper processing, chemical analysis of the products showed a range of available P2O5 content from 9.56 to 19.24% depending upon the amount of acid and its dilution. The results reveal at that 1:1 dilutions gave the highest P2O5 content (19.24%, lowest free acid (6 % and 32% weight increase. The application of acid beyond or below this combination either pure or diluted gave hygroscopic product and higher free acids. The cost incurred upon the manual processing was almost half the prevailing rates in the market. These results lead to conclude that application of sulfuric acid at the rate of 60 liters 100 kg-1 with the dilution of 50% (v/v can yield better kind of SSP from Hazara rock phosphate at lower prices.

  9. Evaluation of intestinal phosphate binding to improve the safety profile of oral sodium phosphate bowel cleansing.

    Directory of Open Access Journals (Sweden)

    Stef Robijn

    Full Text Available Prior to colonoscopy, bowel cleansing is performed for which frequently oral sodium phosphate (OSP is used. OSP results in significant hyperphosphatemia and cases of acute kidney injury (AKI referred to as acute phosphate nephropathy (APN; characterized by nephrocalcinosis are reported after OSP use, which led to a US-FDA warning. To improve the safety profile of OSP, it was evaluated whether the side-effects of OSP could be prevented with intestinal phosphate binders. Hereto a Wistar rat model of APN was developed. OSP administration (2 times 1.2 g phosphate by gavage with a 12h time interval induced bowel cleansing (severe diarrhea and significant hyperphosphatemia (21.79 ± 5.07 mg/dl 6h after the second OSP dose versus 8.44 ± 0.97 mg/dl at baseline. Concomitantly, serum PTH levels increased fivefold and FGF-23 levels showed a threefold increase, while serum calcium levels significantly decreased from 11.29 ± 0.53 mg/dl at baseline to 8.68 ± 0.79 mg/dl after OSP. OSP administration induced weaker NaPi-2a staining along the apical proximal tubular membrane. APN was induced: serum creatinine increased (1.5 times baseline and nephrocalcinosis developed (increased renal calcium and phosphate content and calcium phosphate deposits on Von Kossa stained kidney sections. Intestinal phosphate binding (lanthanum carbonate or aluminum hydroxide was not able to attenuate the OSP induced side-effects. In conclusion, a clinically relevant rat model of APN was developed. Animals showed increased serum phosphate levels similar to those reported in humans and developed APN. No evidence was found for an improved safety profile of OSP by using intestinal phosphate binders.

  10. Phosphate application to firing range soils for Pb immobilization: The unclear role of phosphate

    International Nuclear Information System (INIS)

    Chrysochoou, Maria; Dermatas, Dimitris; Grubb, Dennis G.

    2007-01-01

    Phosphate treatment has emerged as a widely accepted approach to immobilize Pb in contaminated soils and waste media, relying on the formation of the highly insoluble mineral pyromorphite as solubility-controlling phase for Pb. As such, phosphate treatment has been proposed as a Best Management Practice (BMP) for firing ranges where Pb occurs in its metallic forms and several other phases (carbonates, oxides). While pyromorphite thermodynamically has the potential to control Pb solubility at low levels, its formation is kinetically controlled by pH, the solubility of the phosphate source, and the solubility of Pb species. Treatability studies have shown that excess quantities of soluble and acidic phosphate sources, such as phosphoric acid, are necessary for successful in situ treatment. Even under these conditions, Extended X-ray Absorption Fine Structure (EXAFS), the only reliable method to identify and quantify Pb speciation, showed that Pb conversion to pyromorphite in in situ treated soils was less than 45% after 32 months. Furthermore, the use of lime (CaO) to restore soil pH in acidified soil treatments inhibited further conversion. Additionally, phosphate treatment is known to reduce bioavailability through pyromorphite formation in the intestinal tract, and the phytoaccumulation of Pb; both desirable effects for Pb-impacted areas. Given the costs of phosphate treatment, the use of biogenic phosphate sources, such as bone meal, may be a more environmentally sustainable approach toward this end. In the many studies focusing on phosphate treatment, the attendant P leaching and eutrophication have been largely overlooked, along with other issues such as the enhanced leaching of oxyanionic contaminants, such as Se, As and W. The success and sustainability of applying phosphate as a BMP in firing range soils therefore remain questionable

  11. Observing participating observation

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2011-01-01

    Current methodology concerning participating observation in general leaves the act of observation unobserved. Approaching participating observation from systems theory offers fundamental new insights into the topic. Observation is always participation. There is no way to escape becoming...

  12. Observing participating observation

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2010-01-01

    Current methodology concerning participating observation in general leaves the act of observation unobserved. Approaching participating observation from systems theory offers fundamental new insights into the topic. Observation is always participation. There is no way to escape becoming...

  13. Uranium-phosphate relationship in phosphated chalks of the Mons and Picardie Bassins

    Energy Technology Data Exchange (ETDEWEB)

    Quinif, Y; Charlet, J M; Dupuis, C; Robaszynski, F [Faculte Polytechnique de Mons (Belgium)

    1981-11-30

    The lithological and geochemical conditions relative to the ''Senonian'' phosphatic chalks are relatively simple in the Basins of Mons (Belgium) and of Picardy (France). Their characteristics permit us to study chiefly the uranium-phosphate relation. It appears a very good linear correlation between the phosphate and the uranium. The coefficient U/P/sub 2/O/sub 5/ remains a constant from the bottom to the top of the same section, but changes in space for synchronic formations (lateral variation of geochemical facies) and in time for two separated basins.

  14. Worker participation - the Netherlands

    OpenAIRE

    Kwantes, J.H.

    2014-01-01

    Worker participation relates to the involvement of workers in the management decision-making processes. In this article attention is focused on worker participation related to occupational safety and health in the Netherlands. Worker participation can refer either to direct or indirect participation by the worker. Indirect participation involves employee representation, while direct participation relates to individual involvement in management’s decision-making processes. In the Framework Dir...

  15. Uranium from phosphates in the United Arab Republic

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1959-04-15

    In response to a request from the UAR Government, the IAEA sent a Soviet expert, to make an on-the-spot study of data on the mining and processing of phosphates in the UAR and to examine the possibility of recovering uranium from the phosphate ores. In his report to the IAEA Director General, he has listed the following conclusions: 1.The uranium content of run-of-the-mine phosphoric ores in the United Arab Republic is very low and the recovery of uranium from them is therefore hardly likely to be an economic proposition. 2. It is essential to press on with prospecting work in order to discover richer uranium deposits and regions of phosphoritic ores. 3. It is essential to organize scientific research work on the recovery of uranium from the various types of uranium-bearing phosphoritic ores in the United Arab Republic, using mechanical concentrating methods and chemical processing methods. 4. The Agency could assist in carrying out this work either by sending as many technicians as a required to help in planning and undertaking the research work in the UAR or by getting appropriate Member States to carry out this work on preliminary samples of ore with the participation of representatives of the UAR

  16. Molecular identification of phosphate solubilizing bacterium ...

    African Journals Online (AJOL)

    A phosphate solubilizing bacterium was isolated from the rhizosphere soil of upland rice and identified by 16S rRNA gene sequencing. The gene sequence showed 99% homology with Alcaligenes faecalis. Based on the gene sequence homology, it was identified as A. faecalis. Interaction effect of this bacterium on growth ...

  17. Biodegradation of tert-butylphenyl diphenyl phosphate

    International Nuclear Information System (INIS)

    Heitkamp, M.A.; Freeman, J.P.; Cerniglia, C.E.

    1986-01-01

    The biodegradation of tert-butylphenyl diphenyl phosphate (BPDP) was examined in microcosms containing sediment and water from five different ecosystems as part of studies to elucidate the environmental fate of phosphate ester flame retardants. Biodegradation of [ 14 C]BPDP was monitored in the environmental microcosms by measuring the evolution of 14 CO 2 . Over 37% of BPDP was mineralized after 8 weeks in microcosms from an ecosystem which had chronic exposure to agricultural chemicals. In contrast, only 1.7% of BPDP was degraded to 14 CO 2 in samples collected from a noncontaminated site. The exposure concentration of BPDP affected the percentage which was degraded to 14 CO 2 in microcosms from the two most active ecosystems. Mineralization was highest at a concentration of 0.1 mg of BPDP and was inhibited with 10- and 100-fold higher concentrations of BPDP. The authors observed adaptive increases in both microbial populations and phosphoesterase enzymes in some sediments acclimated to BPDP. Chemical analyses of the residues in the microcosms indicated undegraded BPDP and minor amounts of phenol, tert-butylphenol, diphenyl phosphate, and triphenyl phosphate as biodegradation products. These data suggest that the microbial degradation of BPDP results from at least three catabolic processes and is highest when low concentrations of BPDP are exposed to sediment microorganisms of eutrophic ecosystems which have high phosphotri- and diesterase activities and previous exposure to anthropogenic chemicals

  18. Cadmium versus phosphate in the world ocean

    NARCIS (Netherlands)

    Baar, Hein J.W. de; Saager, Paul M.; Nolting, Rob F.; Meer, Jaap van der

    1994-01-01

    Cadmium (Cd) is one of the best studied trace metals in seawater and at individual stations exhibits a more or less linear relation with phosphate. The compilation of all data from all oceans taken from over 30 different published sources into one global dataset yields only a broad scatterplot of Cd

  19. Characterization of Fe -doped silver phosphate glasses

    Indian Academy of Sciences (India)

    ... to their several spe- cial properties such as large thermal expansion coefficients, ... increase the conductivity of these glasses is to increase the modifier or dopant ... phosphate glasses were measured by the a.c. impedance spectroscopic .... and Fe2O3-doped Ag2O–P2O5 glasses were determined from. DSC curves and ...

  20. Metal complex derivatives of hydrogen uranyl phosphate

    International Nuclear Information System (INIS)

    Grohol, D.; Blinn, E.L.

    1994-01-01

    Derivatives of hydrogen uranyl phosphate were prepared by incorporating transition metal complexes into the uranyl phosphate matrix. The transition metal complexes employed include bis(ethylenediamine)copper(II), bis(1,3-propanediamine)copper(II) chloride, (triethylenetetramine)copper(II), (1,4,8,11-tetraazacyclotetradecane)copper(II), (1,4,8,12-tetraazacyclopentadecane)copper(II), (1,4,8,11-tetraazacyclotetradecane)nickel(II) chloride, (triethylenetetramine)nickel(II) and others. The chemical analyses of these derivatives indicated that the incorporation of the transition metal complexes into the uranyl phosphate matrix via ion exchange was not stoichiometric. The extent of ion exchange is dependent on the size and structure of the transition metal complex. All complexes were characterized by X-ray powder diffractometry, electronic and infrared spectra, thermal analyses and chemical analysis. An attempt was made to correlate the degree of quenching of the luminescence of the uranyl ion to the spacing between the uranyl phosphate layers in the derivatives

  1. (VAM) and phosphate solubilizing bacteria (PSB)

    African Journals Online (AJOL)

    User

    2013-09-18

    Sep 18, 2013 ... mycorrhiza (VAM), and phosphate solubilising bacteria (PSB) individually and in .... Two-way analysis of variance (ANOVA) was carried out at a 0.05 level of significance on the data and SPSS version 13.0 was used.

  2. Bismuth phosphates as intermediate temperature proton conductors

    DEFF Research Database (Denmark)

    Huang, Yunjie; Christensen, Erik; Shuai, Qin

    2017-01-01

    by scanning electron microscopy, X-ray diffraction, FT-IR, thermogravimetric analysis and AC impedance. Under dry atmosphere the pure crystalline and amorphous phosphates exhibit an intrinsic conductivity of up to 10-5 S cm-1 at 250 °C. In the presence of atmospheric humidity the conductivity of both types...

  3. Nuclear waste immobilization in iron phosphate glasses

    International Nuclear Information System (INIS)

    Garcia, D.A.; Rodriguez, Diego A.; Menghini, Jorge E.; Bevilacqua, Arturo

    2007-01-01

    Iron-phosphate glasses have become important in the nuclear waste immobilization area because they have some advantages over silicate-based glasses, such as a lower processing temperature and a higher nuclear waste load without losing chemical and mechanical properties. Structure and chemical properties of iron-phosphate glasses are determined in terms of the main components, in this case, phosphate oxide along with the other oxides that are added to improve some of the characteristics of the glasses. For example, Iron oxide improves chemical durability, lead oxide lowers fusion temperature and sodium oxide reduces viscosity at high temperature. In this work a study based on the composition-property relations was made. We used different techniques to characterize a series of iron-lead-phosphate glasses with uranium and aluminium oxide as simulated nuclear waste. We used the Arquimedes method to determine the bulk density, differential temperature analysis (DTA) to determine both glass transition temperature and crystallization temperature, dilatometric analysis to calculate the linear thermal expansion coefficient, chemical durability (MCC-1 test) and X-ray diffraction (XRD). We also applied some theoretic models to calculate activation energies associated with the glass transition temperature and crystallization processes. (author)

  4. Spectrophotometric Determination of Nitrate and Phosphate Levels ...

    African Journals Online (AJOL)

    Twelve drinking water samples from boreholes were collected from various sampling sites around the vicinity of Kura irrigated farmlands using polythene plastic containers and were analysed for the nitrate and phosphate levels using uV – visible spectrophotometer. From the results, it was found that all the samples had ...

  5. Mesoporous titanium phosphates and related molecular sieves ...

    Indian Academy of Sciences (India)

    Unknown

    phosphate using a dilute H2O2 oxidant supports the tetrahedral coordination of Ti in ... production of H2 by photo-reduction of water under UV light irradiation. ... have been extensively studied and used as acid catalysts, adsorbents and ion ... mesoporous silica materials is also of outstanding interest because of their ...

  6. Electrosprayed calcium phosphate coatings for biomedical purposes.

    NARCIS (Netherlands)

    Leeuwenburgh, S.C.G.

    2006-01-01

    In this thesis, the suitability of the Electrostatic Spray Deposition (ESD) technique was studied for biomedical purposes, i.e., deposition of calcium phosphate (CaP) coatings onto titanium substrates. Using ESD, which is a simple and cheap deposition method for inorganic and organic coatings, it

  7. Serum Calcium, Inorganic Phosphates and some Haematological ...

    African Journals Online (AJOL)

    Objectives: Sickle cell disease has long been associated with bone deformities and pain. Mineral salts such as calcium and inorganic phosphate are critical in bone formation and metabolism. This investigation was designed to study the serum concentration of these minerals as well as some haematological parameters in ...

  8. Isolation and Characterization of Efficient Phosphate Solubilizing ...

    African Journals Online (AJOL)

    Vostro154032bit

    ABSTRACT. Applications of biofertilizer have great practical importance for increasing fertility of the soil and reducing environmental pollution. Screening and characterizing phosphate solubilizing Bacillus. (PSB) strains from different agroecologies of Tigray soil and in vitro assessment for the adaptability under different ...

  9. Isolation and characterization of efficient Phosphate Solubilizing ...

    African Journals Online (AJOL)

    Applications of biofertilizer have great practical importance for increasing fertility of the soil and reducing environmental pollution. Screening and characterizing phosphate solubilizing Bacillus (PSB) strains from different agroecologies of Tigray soil and in vitro assessment for the adaptability under different abiotic stress ...

  10. Thermochemical investigations on uranyl phosphates and arsenates

    International Nuclear Information System (INIS)

    Barten, H.

    1986-01-01

    Results are described of a study of the thermochemical stability of anhydrous phosphates and arsenates. The results of phase studies deal with compound formation and characterization, coexisting phases and limiting physical or chemical properties. The uranyl phosphates evolve oxygen at higher temperatures and the arsenates lose arsenic oxide vapour. These phenomena give the possibility to describe their thermodynamic stabilities. Thus oxygen pressures of uranyl phosphates have been measured using a static, non-isothermal method. Having made available the pure anhydrous compounds in the course of this investigation, molar thermodynamic quantities have been measured as well. These include standard enthalpies of formation from solution calorimetry and high-temperature heat-capacity functions derived from enthalpy increments measured. Some attention is given to compounds with uranium in valencies lower than six which have been met during the investigation. An evaluation is made of the thermodynamics of the compounds studied, to result in tabulized high-temperature thermodynamic functions. Relative stabilities within the systems are discussed and comparisons of the uranyl phosphates and the arsenates are made. (Auth.)

  11. Thermochemical investigations on uranyl phosphates and arsenates

    International Nuclear Information System (INIS)

    Barten, H.

    1986-11-01

    The results are described of a study of the thermochemical stability of anhydrous uranyl phosphates and arsenates. A number of aspects of chemical technological importance are indicated in detail. The synthesized anhydrous uranyl phosphates and arsenates were very hygroscopic, so that experiments on these compounds had to be carried out under moisture-free conditions. Further characterisation of these compounds are given, including a study of their thermal stabilities and phase relations. The uranyl phosphates reduced reversibly at temperatures of the order of 1100 to 1600 0 C. This makes it possible to express their relative stabilities quantitatively, in terms of the oxygen pressures of the reduction reactions. The thermal decomposition of uranyl arsenates did not occur by reduction, as for the phosphates, but by giving off arsenic oxide vapour. The results of measurements of enthalpies of solution led to the determination of the enthalpies of formation, heat capacity and the standard entropies of the uranyl arsenates. The thermochemical functions at high-temperatures could consequently be calculated. Attention is paid to the possible formation of uranium arsenates, whose uranium has a valency lower than six, hitherto not reported in literature. It was not possible to prepare arsenates of tetravalent uranium. However, three new compounds were observed, one of these, UAsO 5 , was studied in some detail. (Auth.)

  12. Spectrophotometric Determination of Nitrate and Phosphate Levels ...

    African Journals Online (AJOL)

    MBI

    2013-04-09

    Apr 9, 2013 ... may help in the growth of algae (Beavington,. 1977). Determination of phosphate ion in drinking water. 50cm3 of water sample was pipetted into a 500cm3 volumetric flask, 5cm3 of Ammonium molybdate solution and 3.0cm3 of ascorbic acid were added with swirling, the mixture was diluted to the mark with ...

  13. PREVENTION OF PHOSPHATE - INDUCED MITOCHONDRIAL SWELLING

    Science.gov (United States)

    Kroll, Arnold J.; Kuwabara, Toichiro

    1962-01-01

    The prevention of phosphate-induced mitochondrial swelling in the whole retina of the rabbit was studied with the electron microscope. It was found that a mixture of ATP, Mg++, and bovine serum albumin protected the mitochondria in vitro. This finding confirmed the results obtained spectrophotometrically with isolated rat liver mitochondria by Lehninger. PMID:13927020

  14. Substoichiometric determination of uranium in phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, N; Hanzawa, K; Imura, H

    1986-01-01

    The substoichiometric isotope dilution analysis for U(VI) in a synergic extraction system of an excess amount of a chelating agent hexafluoroacetylacetone (HHFA) and a substoichiometric amount of U(VI) can be precisely extracted, and U down to ppm levels can be accurately determined by the present method. This method was applied to the analysis of a phosphate rock.

  15. TUCS/phosphate mineralization of actinides

    Energy Technology Data Exchange (ETDEWEB)

    Nash, K.L. [Argonne National Lab., IL (United States)

    1997-10-01

    This program has as its objective the development of a new technology that combines cation exchange and mineralization to reduce the concentration of heavy metals (in particular actinides) in groundwaters. The treatment regimen must be compatible with the groundwater and soil, potentially using groundwater/soil components to aid in the immobilization process. The delivery system (probably a water-soluble chelating agent) should first concentrate the radionuclides then release the precipitating anion, which forms thermodynamically stable mineral phases, either with the target metal ions alone or in combination with matrix cations. This approach should generate thermodynamically stable mineral phases resistant to weathering. The chelating agent should decompose spontaneously with time, release the mineralizing agent, and leave a residue that does not interfere with mineral formation. For the actinides, the ideal compound probably will release phosphate, as actinide phosphate mineral phases are among the least soluble species for these metals. The most promising means of delivering the precipitant would be to use a water-soluble, hydrolytically unstable complexant that functions in the initial stages as a cation exchanger to concentrate the metal ions. As it decomposes, the chelating agent releases phosphate to foster formation of crystalline mineral phases. Because it involves only the application of inexpensive reagents, the method of phosphate mineralization promises to be an economical alternative for in situ immobilization of radionuclides (actinides in particular). The method relies on the inherent (thermodynamic) stability of actinide mineral phases.

  16. Isolation and Characterization of Efficient Phosphate Solubilizing ...

    African Journals Online (AJOL)

    Vostro154032bit

    Research Article http://dx.doi.org/10.4314/mejs.v9i2.9. Momona Ethiopian Journal of Science (MEJS), V9(2):262-273,2017 ©CNCS, Mekelle University, ISSN:2220-184X. Isolation and Characterization of Efficient Phosphate Solubilizing Bacillus (PSB) from Different Agro-ecological Zones of Tigray Soil, Ethiopia. Kibrom, F.G.

  17. Intercalation of cyclic ketones into vanadyl phosphate

    Czech Academy of Sciences Publication Activity Database

    Zima, Vítězslav; Melánová, Klára; Beneš, L.; Trchová, Miroslava; Dybal, Jiří

    2005-01-01

    Roč. 178, č. 1 (2005), s. 314-320 ISSN 0022-4596 R&D Projects: GA AV ČR KSK4050111 Institutional research plan: CEZ:AV0Z40500505 Keywords : vanadyl phosphate Subject RIV: CA - Inorganic Chemistry Impact factor: 1.725, year: 2005

  18. Calcium phosphate saturation in seawater around the Andaman Island

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, S.; Reddy, C.V.G.

    Ionic product (IP) of calcium phosphate is calculated at some stations around Andaman Island. The depthwise variations of the ionic product of calcium phosphate seem to follow a normal trend with maximum saturation value between 100 to 200 m. Using...

  19. Genetics Home Reference: glucose-6-phosphate dehydrogenase deficiency

    Science.gov (United States)

    ... deficiency Encyclopedia: Glucose-6-phosphate dehydrogenase test Encyclopedia: Hemolytic anemia Encyclopedia: Newborn jaundice Health Topic: Anemia Health Topic: G6PD Deficiency Health Topic: Newborn Screening Genetic and Rare Diseases Information Center (1 link) Glucose-6-phosphate dehydrogenase ...

  20. Preparation of Edible Corn Starch Phosphate with Highly Reactive ...

    African Journals Online (AJOL)

    1Food & Bioengineering Department, Henan University of Science and Technology, Luoyang, Henan 471003 ... Purpose: To prepare edible corn starch phosphate under optimized experimental conditions. ... In food industry, starch phosphate.

  1. Calcium phosphate saturation in the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, S.; Reddy, C.V.G.

    Temperature, inorganic phosphate concentration and pH seem to be the major factors influencing the degree of saturation of calcium phosphate in sea water. Two water regions can be demarcated in the study area based on the saturation patterns...

  2. Analyses of uranium in some phosphate commercial products

    International Nuclear Information System (INIS)

    Kamel, N.H.M.; Sohsah, M.; Mohammad, H.M.; Sadek, M.

    2005-01-01

    The raw materials used in manufacturing of phosphate fertilizer products were derived from rocks. Rocks contain a remarkable of natural radioactivity. Uranium and phosphorous were originally initiated at the same time of the initiated rocks. The purpose of this research is to investigate solubility of uranium phosphate species at the phosphate fertilizer samples, samples including; raw phosphate material, single super phosphates (SSP) granules and powdered, triple super phosphates (TSP) and phosphogypsum samples were obtained from Abu-Zabal factory in Egypt. Solubility of uranium phosphate species was estimated. It was found that, less than half of the uranium phosphate species are soluble in water. The soluble uranium may be enter into the food chains by plant. Therefore, restriction should be done in order to limit contamination of land and the public

  3. Recovery of uranium and the lanthanides from phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Habashi, F; Awadalla, F T; Zailaf, M

    1986-06-01

    A process is proposed for the treatment of phosphate rock for the recovery of uranium and lanthanides. The process assures the production of phosphatic fertilisers without polluting the environment with radioactive material.

  4. Cloning and expression of pineapple sucrose- phosphate synthase ...

    African Journals Online (AJOL)

    hope&shola

    2010-12-06

    Dec 6, 2010 ... phosphate; EDTA, ethylene diamine tetraacetic acid; Ivr, invertase; SS .... phenolics, tannins and artifacts due to differences of tissue composition ..... Banana sucrose-phosphate synthase gene expression during fruit ripening.

  5. Iron phosphate glass containing simulated fast reactor waste: Characterization and comparison with pristine iron phosphate glass

    International Nuclear Information System (INIS)

    Joseph, Kitheri; Asuvathraman, R.; Venkata Krishnan, R.; Ravindran, T.R.; Govindaraj, R.; Govindan Kutty, K.V.; Vasudeva Rao, P.R.

    2014-01-01

    Detailed characterization was carried out on an iron phosphate glass waste form containing 20 wt.% of a simulated nuclear waste. High temperature viscosity measurement was carried out by the rotating spindle method. The Fe 3+ /Fe ratio and structure of this waste loaded iron phosphate glass was investigated using Mössbauer and Raman spectroscopy respectively. Specific heat measurement was carried out in the temperature range of 300–700 K using differential scanning calorimeter. Isoconversional kinetic analysis was employed to understand the crystallization behavior of the waste loaded iron phosphate glass. The glass forming ability and glass stability of the waste loaded glass were also evaluated. All the measured properties of the waste loaded glass were compared with the characteristics of pristine iron phosphate glass

  6. Transfer of Some Major and Trace Elements From Phosphate Rock to Super-Phosphate Fertilizers

    International Nuclear Information System (INIS)

    El-Reefya, H.I.; Bin-Jaz, A.A.; Zaied, M.E.; Badran, H.M.; Badran, H.M.

    2014-01-01

    This study assesses the transfer of some major and trace elements from phosphate rock (PR) to single (SSP) and triple (TSP) superphosphate fertilizers. Samples from a fertilizer plant and local market were collected and analyzed using inductively coupled plasma spectrometer. Cluster analysis indicated that the inner-relationship among the concentration of the elements in PR, SSP, and TSP are different. Only one element (Mo) has concentration in SSP higher than phosphate rock. The production process of these two types of superphosphate leads to transfer higher portion of Mn, B, Cu, Mo, Sr, and V present in the phosphate rock to SSP than TSP. The potentially hazardous element Cd is also transmitted more to SSP than TSP, and Cr is equally transferred to both types. The mean elemental concentrations normalized to the percentage of P 2 O 5 demonstrate that for most elements they are the higher concentrations in SSP are linked to the phosphate contents

  7. Radioactivity of phosphate ores from Karatas-Mazidag phosphate deposit of Turkey

    International Nuclear Information System (INIS)

    Akyuez, T.; Varinlioglu, A.; Kose, A.; Akyuez, S.

    2000-01-01

    The specific activities of 238 U, 226 Ra, 232 Th and 40 K in the composite samples of phosphate ores of type I (grey-coloured ore, with high P 2 O 5 (21-35%) and low calcite content) and of type II (grey coloured calcite ore, with low P 2 O 5 content (5-17%)) of Karatas-Mazidag phosphate deposit, Turkey, have been determined by gamma spectrometry together with phosphatic animal feed ingredients. The concentrations of 238 U, 226 Ra, 232 Th and 40 K were found to be up to 557, 625, 26 and 297 Bq x kg -1 , respectively. Radium equivalent activities of samples were calculated and compared with those given in the literature. Uranium concentration of the individual phosphate samples, from which composite samples of ores of type I and II have been prepared, were found to show and increasing trend with increasing P 2 O 5 and F concentrations. (author)

  8. Glucose-6-phosphate dehydrogenase deficiency does not increase the susceptibility of sperm to oxidative stress induced by H2O2.

    Science.gov (United States)

    Roshankhah, Shiva; Rostami-Far, Zahra; Shaveisi-Zadeh, Farhad; Movafagh, Abolfazl; Bakhtiari, Mitra; Shaveisi-Zadeh, Jila

    2016-12-01

    Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect. G6PD plays a key role in the pentose phosphate pathway, which is a major source of nicotinamide adenine dinucleotide phosphate (NADPH). NADPH provides the reducing equivalents for oxidation-reduction reductions involved in protecting against the toxicity of reactive oxygen species such as H 2 O 2 . We hypothesized that G6PD deficiency may reduce the amount of NADPH in sperms, thereby inhibiting the detoxification of H 2 O 2 , which could potentially affect their motility and viability, resulting in an increased susceptibility to infertility. Semen samples were obtained from four males with G6PD deficiency and eight healthy males as a control. In both groups, motile sperms were isolated from the seminal fluid and incubated with 0, 10, 20, 40, 60, 80, and 120 µM concentrations of H 2 O 2 . After 1 hour incubation at 37℃, sperms were evaluated for motility and viability. Incubation of sperms with 10 and 20 µM H 2 O 2 led to very little decrease in motility and viability, but motility decreased notably in both groups in 40, 60, and 80 µM H 2 O 2 , and viability decreased in both groups in 40, 60, 80, and 120 µM H 2 O 2 . However, no statistically significant differences were found between the G6PD-deficient group and controls. G6PD deficiency does not increase the susceptibility of sperm to oxidative stress induced by H 2 O 2 , and the reducing equivalents necessary for protection against H 2 O 2 are most likely produced by other pathways. Therefore, G6PD deficiency cannot be considered as major risk factor for male infertility.

  9. Worker participation - the Netherlands

    NARCIS (Netherlands)

    Kwantes, J.H.

    2014-01-01

    Worker participation relates to the involvement of workers in the management decision-making processes. In this article attention is focused on worker participation related to occupational safety and health in the Netherlands. Worker participation can refer either to direct or indirect participation

  10. Sorption of cesium on titanium and zirconium phosphates

    International Nuclear Information System (INIS)

    Lebedev, V.N.; Mel'nik, N.A.; Rudenko, A.V.

    2003-01-01

    Titanium and zirconium phosphates were prepared from mineral raw materials of the Kola Peninsula. Their capability to recover cesium cations from the model solutions and liquid radioactive waste (LRW) was studied. Titanium phosphate prepared from solutions formed by titanite breakdown demonstrates greater distribution coefficients of cesium as compared to zirconium phosphate. Titanium phosphate as a cheaper agent featuring greater sorption capacity was recommended for treatment of LRW to remove cesium [ru

  11. Bacterial formation of phosphatic laminites off Peru.

    Science.gov (United States)

    Arning, E T; Birgel, D; Brunner, B; Peckmann, J

    2009-06-01

    Authigenic phosphatic laminites enclosed in phosphorite crusts from the shelf off Peru (10 degrees 01' S and 10 degrees 24' S) consist of carbonate fluorapatite layers, which contain abundant sulfide minerals including pyrite (FeS(2)) and sphalerite (ZnS). Low delta(34)S(pyrite) values (average -28.8 per thousand) agree with bacterial sulfate reduction and subsequent pyrite formation. Stable sulfur isotopic compositions of sulfate bound in carbonate fluorapatite are lower than that of sulfate from ambient sea water, suggesting bacterial reoxidation of sulfide by sulfide-oxidizing bacteria. The release of phosphorus and subsequent formation of the autochthonous phosphatic laminites are apparently caused by the activity of sulfate-reducing bacteria and associated sulfide-oxidizing bacteria. Following an extraction-phosphorite dissolution-extraction procedure, molecular fossils of sulfate-reducing bacteria (mono-O-alkyl glycerol ethers, di-O-alkyl glycerol ethers, as well as the short-chain branched fatty acids i/ai-C(15:0), i/ai-C(17:0) and 10MeC(16:0)) are found to be among the most abundant compounds. The fact that these molecular fossils of sulfate-reducing bacteria are distinctly more abundant after dissolution of the phosphatic laminite reveals that the lipids are tightly bound to the mineral lattice of carbonate fluorapatite. Moreover, compared with the autochthonous laminite, molecular fossils of sulfate-reducing bacteria are: (1) significantly less abundant and (2) not as tightly bound to the mineral lattice in the other, allochthonous facies of the Peruvian crusts consisting of phosphatic coated grains. These observations confirm the importance of sulfate-reducing bacteria in the formation of the phosphatic laminite. Model calculations highlight that organic matter degradation by sulfate-reducing bacteria has the potential to liberate sufficient phosphorus for phosphogenesis.

  12. Comparative study on in vitro biocompatibility of synthetic octacalcium phosphate and calcium phosphate ceramics used clinically.

    Science.gov (United States)

    Morimoto, Shinji; Anada, Takahisa; Honda, Yoshitomo; Suzuki, Osamu

    2012-08-01

    The present study was designed to investigate the extent to which calcium phosphate bone substitute materials, including osteoconductive octacalcium phosphate (OCP), display cytotoxic and inflammatory responses based on their dissolution in vitro. Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) ceramics, which are clinically used, as well as dicalcium phosphate dihydrate (DCPD) and synthesized OCP were compared. The materials were well characterized by chemical analysis, x-ray diffraction and Fourier transform infrared spectroscopy. Calcium and phosphate ion concentrations and the pH of culture media after immersion of the materials were determined. The colony forming rate of Chinese hamster lung fibroblasts was estimated with extraction of the materials. Proliferation of bone marrow stromal ST-2 cells and inflammatory cytokine TNF-α production by THP-1 cells grown on the material-coated plates were examined. The materials had characteristics that corresponded to those reported. DCPD was shown to dissolve the most in the culture media, with a marked increase in phosphate ion concentration and a reduction in pH. ST-2 cells proliferated well on the materials, with the exception of DCPD, which markedly inhibited cellular growth. The colony forming capacity was the lowest on DCPD, while that of the other calcium phosphates was not altered. In contrast, TNF-α was not detected even in cells grown on DCPD, suggesting that calcium phosphate materials are essentially non-inflammatory, while the solubility of the materials can affect osteoblastic and fibroblastic cellular attachment. These results indicate that OCP is biocompatible, which is similar to the materials used clinically, such as HA. Therefore, OCP could be clinically used as a biocompatible bone substitute material.

  13. Phosphate and phosphate fertilizer sector: structure and future prospects. [Uranium recovery

    Energy Technology Data Exchange (ETDEWEB)

    Zenaidi, B

    1981-12-01

    A statement of the past evolution of this sector's structure is given. Various prospective studies which have been made are reviewed and lead to the precision of the phosphate requirement in the year 2000 which is between 200 and 250 Mt. Only a small section p. 696-697 is devoted to recovery of uranium contained in phosphate and prospects in this field are given.

  14. Physico-chemical characterization of Ogun and Sokoto phosphate ...

    African Journals Online (AJOL)

    Gypsum, calcite and lime were associated with both rock phosphates indicating their liming potential in the soil. ORP was more soluble in water, probably because it ... fertilizers and direct application in crop production. Keywords: Phosphorus, apatite, crop production, fertilizer, Ogun rock phosphate, Sokoto rock phosphate ...

  15. The phosphate balance : current developments and future outlook

    NARCIS (Netherlands)

    Enk, van R.J.; Vee, van der G.; Acera, L.K.; Schuiling, R.; Ehlert, P.A.I.

    2011-01-01

    Phosphate is essential for agricultural production and therefore plays a key role in the global production of food and biofuels. There are no agricultural alternatives for phosphate, and a substantial fraction of our annual phosphate consumption is dispersed into the environment where it is largely

  16. The phosphate balance : Current developments and future outlook

    NARCIS (Netherlands)

    Enk, R.J. van; Acera, L.K.; Schuiling, R.D.; Ehlert, P.; de Wilt, J.G.; van Haren, R.J.F.

    2011-01-01

    Phosphate is essential for agricultural production and therefore plays a key role in the global production of food and biofuels. There are no agricultural alternatives for phosphate, and a substantial fraction of our annual phosphate consumption is dispersed into the environment where it is largely

  17. 21 CFR 582.5697 - Riboflavin-5-phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Riboflavin-5-phosphate. 582.5697 Section 582.5697 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5697 Riboflavin-5-phosphate. (a) Product. Riboflavin-5-phosphate. (b) Conditions of use...

  18. 21 CFR 582.1781 - Sodium aluminum phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium aluminum phosphate. 582.1781 Section 582.1781 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1781 Sodium aluminum phosphate. (a) Product. Sodium aluminum phosphate. (b) Conditions of...

  19. 21 CFR 182.1781 - Sodium aluminum phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium aluminum phosphate. 182.1781 Section 182.1781 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1781 Sodium aluminum phosphate. (a) Product. Sodium aluminum phosphate. (b...

  20. Radiological impact of natural radioactivity in Egyptian phosphate rocks, phosphogypsum and phosphate fertilizers

    International Nuclear Information System (INIS)

    El-Bahi, S.M.; Sroor, A.; Mohamed, Gehan Y.; El-Gendy, N.S.

    2017-01-01

    In this study, the activity concentrations of the natural radionuclides in phosphate rocks and its products were measured using a high- purity germanium detector (HPGe). The obtained activity results show remarkable wide variation in the radioactive contents for the different phosphate samples. The average activity concentration of "2"3"5U, "2"3"8U, "2"2"6Ra, "2"3"2Th and "4"0K was found as (45, 1031, 786, 85 and 765 Bq/kg) for phosphate rocks, (28, 1234, 457, 123 and 819 Bq/kg) for phosphate fertilizers, (47, 663, 550, 79 and 870 Bq/kg) for phosphogypsum and (25, 543, 409, 54 and 897 Bq/kg) for single super phosphate respectively. Based on the measured activities, the radiological parameters (activity concentration index, absorbed gamma dose rate in outdoor and indoor and the corresponding annual effective dose rates and total excess lifetime cancer risk) were estimated to assess the radiological hazards. The total excess lifetime cancer risk (ELCR) has been calculated and found to be high in all samples, which related to high radioactivity, representing radiological risk for the health of the population. - Highlights: • Level of radioactivity of phosphate rocks and by-products samples. • The radiological health hazard parameters. • Radiological risk to the health of the population. • The excess lifetime cancer risk factor.

  1. Phosphate uptake kinetics for four species of submerged freshwater macrophytes measured by a 33P phosphate radioisotope technique

    DEFF Research Database (Denmark)

    Christiansen, Nina Høj; Andersen, Frede Østergaard; Jensen, Henning S.

    2016-01-01

    Phosphate (Pi) uptake kinetics were determined in shoot and root tissues for four freshwater macrophyte species, Littorella uniflora, Potamogeton perfoliatus, Myriophyllum alterniflorum and Elodea canadensis, using a radioactive 33P phosphate technique. Collection of plant material in the oligotr...

  2. Infrared-spectroscopy analysis of zinc phosphate and nickel and manganese modified zinc phosphate coatings on electrogalvanized steel

    International Nuclear Information System (INIS)

    Fernandes, Kirlene Salgado; Alvarenga, Evandro de Azevedo; Lins, Vanessa de Freitas Cunha

    2011-01-01

    Hopeite-type phosphate coatings in which zinc is partially replaced by other metals like manganese and nickel are of great interest for the automotive and home appliance industries. Such industries use phosphate conversion coatings on galvanized steels in association with cataphoretic electro painting. Zinc phosphates modified with manganese and nickel are isomorphic with the hopeite, and the phase identification using X-ray diffraction is difficult. In this paper, the phosphate coatings are identified using the Fourier transform infrared spectroscopy (FTIR). (author)

  3. Phosphate additives in food--a health risk.

    Science.gov (United States)

    Ritz, Eberhard; Hahn, Kai; Ketteler, Markus; Kuhlmann, Martin K; Mann, Johannes

    2012-01-01

    Hyperphosphatemia has been identified in the past decade as a strong predictor of mortality in advanced chronic kidney disease (CKD). For example, a study of patients in stage CKD 5 (with an annual mortality of about 20%) revealed that 12% of all deaths in this group were attributable to an elevated serum phosphate concentration. Recently, a high-normal serum phosphate concentration has also been found to be an independent predictor of cardiovascular events and mortality in the general population. Therefore, phosphate additives in food are a matter of concern, and their potential impact on health may well have been underappreciated. We reviewed pertinent literature retrieved by a selective search of the PubMed and EU databases (www.zusatzstoffe-online.de, www.codexalimentarius.de), with the search terms "phosphate additives" and "hyperphosphatemia." There is no need to lower the content of natural phosphate, i.e. organic esters, in food, because this type of phosphate is incompletely absorbed; restricting its intake might even lead to protein malnutrition. On the other hand, inorganic phosphate in food additives is effectively absorbed and can measurably elevate the serum phosphate concentration in patients with advanced CKD. Foods with added phosphate tend to be eaten by persons at the lower end of the socioeconomic scale, who consume more processed and "fast" food. The main pathophysiological effect of phosphate is vascular damage, e.g. endothelial dysfunction and vascular calcification. Aside from the quality of phosphate in the diet (which also requires attention), the quantity of phosphate consumed by patients with advanced renal failure should not exceed 1000 mg per day, according to the guidelines. Prospective controlled trials are currently unavailable. In view of the high prevalence of CKD and the potential harm caused by phosphate additives to food, the public should be informed that added phosphate is damaging to health. Furthermore, calls for labeling

  4. Impaired Phosphate Tolerance Revealed With an Acute Oral Challenge.

    Science.gov (United States)

    Turner, Mandy E; White, Christine A; Hopman, Wilma M; Ward, Emilie C; Jeronimo, Paul S; Adams, Michael A; Holden, Rachel M

    2018-01-01

    Elevated serum phosphate is consistently linked with cardiovascular disease (CVD) events and mortality in the setting of normal and impaired kidney function. However, serum phosphate does not often exceed the upper limit of normal until glomerular filtration rate (GFR) falls below 30 mL/min/m 2 . It was hypothesized that the response to an oral, bioavailable phosphate load will unmask impaired phosphate tolerance, a maladaptation not revealed by baseline serum phosphate concentrations. In this study, rats with varying kidney function as well as normo-phosphatemic human subjects, with inulin-measured GFR (13.2 to 128.3mL/min), received an oral phosphate load. Hormonal and urinary responses were evaluated over 2 hours. Results revealed that the more rapid elevation of serum phosphate was associated with subjects and rats with higher levels of kidney function, greater responsiveness to acute changes in parathyroid hormone (PTH), and significantly more urinary phosphate at 2 hours. In humans, increases in urinary phosphate to creatinine ratio did not correlate with baseline serum phosphate concentrations but did correlate strongly to early increase of serum phosphate. The blunted rise in serum phosphate in rats with CKD was not the result of altered absorption. This result suggests acute tissue deposition may be altered in the setting of kidney function impairment. Early recognition of impaired phosphate tolerance could translate to important interventions, such as dietary phosphate restriction or phosphate binders, being initiated at much higher levels of kidney function than is current practice. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

  5. Connecting Participant Observation Positions

    DEFF Research Database (Denmark)

    McCurdy, Patrick; Uldam, Julie

    2014-01-01

    In this article, we argue for the importance of considering participant observation roles in relation to both insider/outsider and overt/covert roles. Through combining key academic debates on participant observation, which have separately considered insider/outsider and overt/covert participant...... observation, we develop a reflexive framework to assist researchers in (1) locating the type of participant observation research; (2) identifying implications of participant observation for both the research and the subjects under study; and (3) reflecting on how one’s role as participant observer shifts over...

  6. Application of Potential Phosphate-Solubilizing Bacteria and Organic Acids on Phosphate Solubilization from Phosphate Rock in Aerobic Rice

    Directory of Open Access Journals (Sweden)

    Qurban Ali Panhwar

    2013-01-01

    Full Text Available A study was conducted at Universiti Putra Malaysia to determine the effect of phosphate-solubilizing bacteria (PSB and organic acids (oxalic & malic on phosphate (P solubilization from phosphate rock (PR and growth of aerobic rice. Four rates of each organic acid (0, 10, 20, and 30 mM, and PSB strain (Bacillus sp. were applied to aerobic rice. Total bacterial populations, amount of P solubilization, P uptake, soil pH, and root morphology were determined. The results of the study showed significantly high P solubilization in PSB with organic acid treatments. Among the two organic acids, oxalic acid was found more effective compared to malic acid. Application of oxalic acid at 20 mM along with PSB16 significantly increased soluble soil P (28.39 mg kg−1, plant P uptake (0.78 P pot−1, and plant biomass (33.26 mg. Addition of organic acids with PSB and PR had no influence on soil pH during the planting period. A higher bacterial population was found in rhizosphere (8.78 log10 cfu g−1 compared to the nonrhizosphere and endosphere regions. The application of organic acids along with PSB enhanced soluble P in the soil solution, improved root growth, and increased plant biomass of aerobic rice seedlings without affecting soil pH.

  7. Prevention of radioactive contamination in the manufacture of phosphate fertilizers

    International Nuclear Information System (INIS)

    Romero G, E.T.

    1995-01-01

    In this work was studied the separation of uranium from the phosphate rock to decrease the level of radioactivity in the phosphate fertilizers, this prevents the redistribution of uranium in the environment. The uranium leaching conditions from phosphate rock were estimated using alkaline solutions. The changes in the natural phosphate rock after leaching were studied. The amenability to separate the uranium from phosphate rock with ammonium carbonate / bicarbonate solution was determined. The uranium extraction was approximately 40%. The leaching conditions showed high selectivity for uranium without changes in the ore structure. The bulk ore was not dissolved. (Author)

  8. Labor Force Participation Rate

    Data.gov (United States)

    City and County of Durham, North Carolina — This thematic map presents the labor force participation rate of working-age people in the United States in 2010. The 2010 Labor Force Participation Rate shows the...

  9. Radical-induced dephosphorylation of fructose phosphates in aqueous solution

    International Nuclear Information System (INIS)

    Zegota, H.; Sonntag, C. von

    1981-01-01

    Oxygen free N 2 O-saturated aqueous solutions of D-fructose-1-phosphate and D-fructose-6-phosphate were γ-irradiated. Inorganic phosphate and phosphate free sugars (containing four to six carbon atoms) were identified and their G-values measured. D-Fructose-1-phosphate yields (G-values in parentheses) inorganic phosphate (1.6), hexos-2-ulose (0.12), 6-deoxy-2,5-hexodiulose (0.16), tetrulose (0.05) and 3-deoxytetrulose (0.15). D-Fructose-6-phosphate yields inorganic phosphate (1.7), hexos-5-ulose (0.1), 6-deoxy-2,5-hexodiulose (0.36), 3-deoxy-2,5-hexodiulose and 2-deoxyhexos-5-ulose (together 0.18). On treatment with alkaline phosphatase further deoxy sugars were recognized and in fructose-1-phosphate G(6-deoxy-2,5-hexodiulose) was increased to a G-value of 0.4. Dephosphorylation is considered to occur mainly after OH attack at C-5 and C-1 in fructose-1-phosphate and at C-5 and C-6 in fructose-6-phosphate. Reaction mechanisms are discussed. (orig.)

  10. Radiophotoluminescence from silver-doped phosphate glass

    International Nuclear Information System (INIS)

    Miyamoto, Y.; Takei, Y.; Nanto, H.; Kurobori, T.; Konnai, A.; Yanagida, T.; Yoshikawa, A.; Shimotsuma, Y.; Sakakura, M.

    2011-01-01

    Glass dosimeter utilizing radiophotoluminescence (RPL) is one of accumulation type solid state dosimeters, which is based on luminescence phenomenon of silver (Ag + ions)-doped phosphate glass exposed to ionizing radiation. In this study, to clarify the emission mechanism of yellow and blue RPL peaks, optical properties of Ag + -doped glass, such as optical absorption spectrum, RPL excitation spectrum before and after X-ray irradiation as well as the lifetime of both RPL peaks are measured. From the results, we discuss the emission mechanism of yellow (peaked at 2.21 eV) and blue (peaked at 2.70 eV) RPL using a proposed energy band diagram for RPL emission and excitation in Ag + -doped phosphate glass. It is found that the radiative lifetime of blue RPL is three orders of magnitude faster than that of yellow RPL.

  11. Sphingosine-1-phosphate and renal vasoconstriction

    DEFF Research Database (Denmark)

    Jensen, Boye L

    2018-01-01

    ) and in conjunction with increased S1P release in pathophysiological situations like sepsis and ischemia-reperfusion incidents, this effect could be relevant in acute kidney injury with parallel decreases in renal blood flow and GFR. This article is protected by copyright. All rights reserved.......In the present issue of Acta Physiologica, Guan et al. in their article "Mechanisms of sphingosine-1-phosphate-mediated vasoconstriction of rat afferent arterioles" (1) address the signaling events associated with sphingosine-1-phosphate (S1P)-mediated renal afferent vasoconstriction and show in......, technically demanding, blood-perfused juxtamedullary nephron preparation that S1P signaling relies predominantly on transmembrane calcium influx from the extracellular fluid through L-type calcium channels with contribution from oxidative stress metabolites(1) . So not only is new information on S1P signaling...

  12. Radon Progeny in Egyptian Underground Phosphate Mines

    International Nuclear Information System (INIS)

    El-Hady, M.A.; Mohammed, A.; El-Hussein, A.; Ali, A.E.; Ahmed, A.A.

    2001-01-01

    In addition to the workers in uranium mines, the staff of other underground mines, such as workers in underground phosphate mines, can be exposed to 222 Rn and its progeny. In this study the individual radon progeny concentrations were measured in three Egyptian underground phosphate mines to estimate the occupational exposure of the workers at those sites. A filter method was used to measure individual radon progeny concentrations ( 218 Po, 214 Pb and 214 Po). The reported mean values of radon progeny concentrations exceed the action levels which are recommended by ICRP 65 (1993). Based on the measured individual radon progeny concentrations ( 218 Po, 214 Pb and 214 Po) in these mines, the annual effective dose for the workers has been calculated using the lung dose model of ICRP 66 (1994). According to the obtained results, some countermeasures were recommended in this study to minimise these exposure levels. (author)

  13. Environmental prospects of uranium from mineral phosphates

    International Nuclear Information System (INIS)

    Schnug, Ewald; Haneklaus, Nils

    2012-01-01

    Uranium (U) is a natural resource that is found in rock phosphates (P). Each year farmers apply unwittingly 167 t/yr U to their soils by P fertilisation. If extracted and used for electricity generation with state of the art nuclear power plants this amount of U could cover the energy demand of 2.4 x 10 6 average German households. Otherwise this finite resource is wasted. U from P fertilisers is an uncommon contribution of agriculture to climate protection. Using the key to calculate the CO 2 depending German car tax band, 1 kilogram P would be valued with 1.8 Euro. More than that the extraction of U from rock phosphates is an efficient measure to avoid U entering the food chain. In particular translocation processes in soils of fertiliser-applied U by run-off and leaching which result in the contamination of surface waters and finally drinking water can be impeded efficiently. (orig.)

  14. Infrared spectroscopy of different phosphates structures.

    Science.gov (United States)

    Jastrzębski, W; Sitarz, M; Rokita, M; Bułat, K

    2011-08-15

    Infrared (IR) spectroscopic studies of mineral and synthetic phosphates have been presented. The interpretation of the spectra has been preceded by the isolated [PO(4)](3-) tetrahedron spectra analyse. The K(3)PO(4) saturated aqueous solution was measured in the special cell for liquids. The obtained IR results have been compared with the theoretical number of IR-active modes. The number and positions of the bands due to P-O vibrations have been established. The phase composition of the phosphates has been determined using XRD and IR spectroscopy methods. The influence of non-tetrahedral cations on the shape of the spectra and the positions of bands has been analysed and the crystalline field splitting effect has been discussed. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. TTPIXE analysis of phosphate rocks and phosphogypsum

    International Nuclear Information System (INIS)

    Martin, J.E.; Respaldiza, M.A.; Ontalba, M.A.; Garcia-Tenorio, R.; Bolivar, J.P.; Silva, M.F. da

    1999-01-01

    The TTPIXE technique was used for the determination of the concentrations of major, minor and trace elements in phosphate rock and phosphogypsum samples. All the samples came from a fertilizer industry site in Huelva (SW of Spain). The analyses were done using proton beams from the 3 MV Van de Graaff accelerator of the 'Instituto Tecnologico e Nuclear' (ITN), Sacavem (Portugal). The aim was to obtain data about the distribution of the different elements in the process of P 2 O 5 production in the factory. The information obtained allowed evaluation of the effectiveness of the chemical treatment employed, and gave a detailed information about the elemental composition of phosphogypsum, the main by-product of phosphate fertilizer production. These data can be useful to define the phosphogypsum management and to evaluate its environmental impact

  16. Aluminum phosphate ceramics for waste storage

    Science.gov (United States)

    Wagh, Arun; Maloney, Martin D

    2014-06-03

    The present disclosure describes solid waste forms and methods of processing waste. In one particular implementation, the invention provides a method of processing waste that may be particularly suitable for processing hazardous waste. In this method, a waste component is combined with an aluminum oxide and an acidic phosphate component in a slurry. A molar ratio of aluminum to phosphorus in the slurry is greater than one. Water in the slurry may be evaporated while mixing the slurry at a temperature of about 140-200.degree. C. The mixed slurry may be allowed to cure into a solid waste form. This solid waste form includes an anhydrous aluminum phosphate with at least a residual portion of the waste component bound therein.

  17. Participation in adult learning

    DEFF Research Database (Denmark)

    Desjardins, Richard

    2010-01-01

    This entry presents an internationally comparative overview of adult learning patterns. Emphasis is placed on who is participating in adult learning and the observed unequal chances to participate. The entry covers three overarching questions that are central to participation research: a) What...

  18. Phosphate sorption characteristics of European alpine soils

    Czech Academy of Sciences Publication Activity Database

    Kaňa, Jiří; Kopáček, Jiří; Camarero, L.; Garcia-Pausas, J.

    2011-01-01

    Roč. 75, č. 3 (2011), s. 862-870 ISSN 0361-5995 R&D Projects: GA ČR(CZ) GA526/09/0567; GA AV ČR(CZ) KJB600960907 Grant - others:EU EMERGE(CZ) EVK1-CT-1999-00032 Institutional research plan: CEZ:AV0Z60170517 Keywords : phosphate sorption * alpine soil s * acidification Subject RIV: DJ - Water Pollution ; Quality Impact factor: 1.979, year: 2011

  19. Phosphate solubilizing bacteria around Indian peninsula

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, M.J.B.D.; Nair, S.; Chandramohan, D.

    nitrophenylphosphate by the culture. One mole of nitrophenol is equivalent to 1 atom of phosphorus. The absorbance was read at 418 nm using DU-6 Beckmann spectrophotometer. The activity was expressed as ?mol.Pml-1d-1. The cultures which showed good phosphate... suitable controls. Growth was measured at 600 nm using DU-6 Beckmann spectrophotometer and phosphatase activity was measured as described earlier. For testing the rate of survival of PSB on various carriers 2 g of finely powdered sediment, rice...

  20. Phosphate Barriers for Immobilization of Uranium Plumes

    International Nuclear Information System (INIS)

    Burns, Peter C.

    2005-01-01

    Uranium contamination of the subsurface has remained a persistent problem plaguing remedial design at sites across the U.S. that were involved with production, handling, storage, milling, and reprocessing of fissile uranium for both civilian and defense related purposes. Remediation efforts to date have relied upon excavation, pump-and-treat, or passive remediation barriers (PRB's) to remove or attenuate uranium mobility. Documented cases convincingly demonstrate that excavation and pump-and-treat methods are ineffective for a number of highly contaminated sites. There is growing concern that use of conventional PRB?s, such as zero-valent iron, are a temporary solution to a problem that will persist for thousands of years. Alternatives to the standard treatment methods are therefore warranted. The core objective of our research is to demonstrate that a phosphorus amendment strategy will result in a reduction of dissolved uranium to below the proposed drinking water standard. Our hypothesis is that long-chain polyphosphate compounds forestall precipitation of sparingly soluble uranyl phosphate compounds, which is key to preventing fouling of wells at the point of injection. Our other fundamental objective is to synthesize and correctly characterize the uranyl phosphate phases that form in the geochemical conditions under consideration. This report summarizes work conducted at the University of Notre Dame through November of 2003 under DOE grant DE-FG07-02ER63489, which has been funded since September, 2002. The objectives at Notre Dame are development of synthesis techniques for uranyl phosphate phases, together with detailed structural and chemical characterization of the myriad of uranyl phosphate phases that may form under geochemical conditions under consideration

  1. Electrosprayed calcium phosphate coatings for biomedical purposes.

    OpenAIRE

    Leeuwenburgh, S.C.G.

    2006-01-01

    In this thesis, the suitability of the Electrostatic Spray Deposition (ESD) technique was studied for biomedical purposes, i.e., deposition of calcium phosphate (CaP) coatings onto titanium substrates. Using ESD, which is a simple and cheap deposition method for inorganic and organic coatings, it was possible to obtain thin CaP layers with an extremely wide range of chemical and morphological characteristics. Various CaP phases and phase mixtures were deposited and a broad diversity of coatin...

  2. Biodiesel production over copper vanadium phosphate

    International Nuclear Information System (INIS)

    Chen, Lei; Yin, Ping; Liu, Xiguang; Yang, Lixia; Yu, Zhongxi; Guo, Xin; Xin, Xinquan

    2011-01-01

    In the present study, copper vanadium phosphate (CuVOP) with three-dimensional network structure was synthesized by hydrothermal method, and was characterized by Infrared spectrum (IR), elemental analysis (EA), EDXRF (energy dispersive X ray fluorescence) etc. Moreover, soybean oil was used as feedstock for producing biodiesel, and biodiesel was produced by CuVOP-catalyzed transesterification process. Response surface methodology was employed to statistically evaluate and optimize the conditions for the maximum conversion to biodiesel, and the effects of amount of catalyst, ratio of methanol to oil, reaction time and reaction temperature were investigated by the 2 4 full-factorial central composite design. The maximum conversion is obtained at amount of catalyst of 1.5%, methanol/oil molar ratio of 6.75, reaction temperature of 65 o C and reaction time of 5 h. Copper vanadium phosphate CuVOP resulted very active in the transesterification reaction for biodiesel production. -- Research highlights: → Copper vanadium phosphate CuVOP with three-dimensional network structure was prepared successfully. Moreover, for the transesterification reaction of soybean oil with methanol under atmospheric pressure, CuVOP had higher catalytic activity and the effects of production conditions such as amount of catalysts etc. were analyzed by response surface methodology.

  3. Trehalose 6-phosphate phosphatases of Pseudomonas aeruginosa.

    Science.gov (United States)

    Cross, Megan; Biberacher, Sonja; Park, Suk-Youl; Rajan, Siji; Korhonen, Pasi; Gasser, Robin B; Kim, Jeong-Sun; Coster, Mark J; Hofmann, Andreas

    2018-04-24

    The opportunistic bacterium Pseudomonas aeruginosa has been recognized as an important pathogen of clinical relevance and is a leading cause of hospital-acquired infections. The presence of a glycolytic enzyme in Pseudomonas, which is known to be inhibited by trehalose 6-phosphate (T6P) in other organisms, suggests that these bacteria may be vulnerable to the detrimental effects of intracellular T6P accumulation. In the present study, we explored the structural and functional properties of trehalose 6-phosphate phosphatase (TPP) in P. aeruginosa in support of future target-based drug discovery. A survey of genomes revealed the existence of 2 TPP genes with either chromosomal or extrachromosomal location. Both TPPs were produced as recombinant proteins, and characterization of their enzymatic properties confirmed specific, magnesium-dependent catalytic hydrolysis of T6P. The 3-dimensional crystal structure of the chromosomal TPP revealed a protein dimer arising through β-sheet expansion of the individual monomers, which possess the overall fold of halo-acid dehydrogenases.-Cross, M., Biberacher, S., Park, S.-Y., Rajan, S., Korhonen, P., Gasser, R. B., Kim, J.-S., Coster, M. J., Hofmann, A. Trehalose 6-phosphate phosphatases of Pseudomonas aeruginosa.

  4. Phosphate phosphors for solid-state lighting

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, Kartik N. [N.S. Science and Arts College, Bhadrawati (India). Dept. of Physics; Swart, H.C. [University of the Orange Free State, Bloemfontein (South Africa). Dept. of Physics; Dhoble, S.J. [R.T.M. Nagpur Univ. (India). Dept. of Physics; Park, Kyeongsoon [Sejong Univ., Seoul (Korea, Republic of). Faculty of Nanotechnology and Advanced Materials Engineering

    2012-07-01

    Essential information for students in researchers working towards new and more efficient solid-state lighting. Comprehensive survey based on the authors' long experience. Useful both for teaching and reference. The idea for this book arose out of the realization that, although excellent surveys and a phosphor handbook are available, there is no single source covering the area of phosphate based phosphors especially for lamp industry. Moreover, as this field gets only limited attention in most general books on luminescence, there is a clear need for a book in which attention is specifically directed toward this rapidly growing field of solid state lighting and its many applications. This book is aimed at providing a sound introduction to the synthesis and optical characterization of phosphate phosphor for undergraduate and graduate students as well as teachers and researchers. The book provides guidance through the multidisciplinary field of solid state lighting specially phosphate phosphors for beginners, scientists and engineers from universities, research organizations, and especially industry. In order to make it useful for a wide audience, both fundamentals and applications are discussed, together.

  5. Radiochemical studies on amorphous zirconium phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, A; Moores, G E [Salford Univ. (UK). Dept. of Chemistry and Applied Chemistry

    1981-01-01

    Amorphous zirconium phosphate (ZrP) is used in some hemodialysis machines for the regeneration of dialysate. Its function is to adsorb ammonium ions formed by the pretreatment of urea by urease. It also adsorbs Ca, Mg and K ions but leaches phosphate ions which are then removed (along with F/sup -/ ions) by a bed of hydrous zirconium oxide. The sodium form of ZrP is used although other forms have been suggested for use. The work reported here describes some preliminary radiochemical studies on the mechanism of release of phosphate ions and its possible relationship to sodium ion-exchange. /sup 32/P labelled material (HHZrP) was used for elution experiments with deionized water and buffer solutions having the pH's 4.2, 7.0 and 9.2. Buffer solutions used were as supplied by BDH. Elution was at four different temperatures in the range 293 to 363/sup 0/C. In the second series of experiments HHZrP was suspended in a NaCl solution labelled with /sup 22/Na. From this, /sup 22/Na labelled ZrP (NaHZrP) was prepared and eluted in the same way as the HHZrP. Results are given and discussed.

  6. Calcium phosphate cement scaffolds with PLGA fibers.

    Science.gov (United States)

    Vasconcellos, Letícia Araújo; dos Santos, Luís Alberto

    2013-04-01

    The use of calcium phosphate-based biomaterials has revolutionized current orthopedics and dentistry in repairing damaged parts of the skeletal system. Among those biomaterials, the cement made of hydraulic grip calcium phosphate has attracted great interest due to its biocompatibility and hardening "in situ". However, these cements have low mechanical strength compared with the bones of the human body. In the present work, we have studied the attainment of calcium phosphate cement powders and their addition to poly (co-glycolide) (PLGA) fibers to increase mechanical properties of those cements. We have used a new method that obtains fibers by dripping different reagents. PLGA fibers were frozen after lyophilized. With this new method, which was patented, it was possible to obtain fibers and reinforcing matrix which furthered the increase of mechanical properties, thus allowing the attainment of more resistant materials. The obtained materials were used in the construction of composites and scaffolds for tissue growth, keeping a higher mechanical integrity. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Phosphine from rocks: mechanically driven phosphate reduction?

    Science.gov (United States)

    Glindemann, Dietmar; Edwards, Marc; Morgenstern, Peter

    2005-11-01

    Natural rock and mineral samples released trace amounts of phosphine during dissolution in mineral acid. An order of magnitude more phosphine (average 1982 ng PH3 kg rock and maximum 6673 ng PH3/kg rock) is released from pulverized rock samples (basalt, gneiss, granite, clay, quartzitic pebbles, or marble). Phosphine was correlated to hardness and mechanical pulverization energy of the rocks. The yield of PH3 ranged from 0 to 0.01% of the total P content of the dissolved rock. Strong circumstantial evidence was gathered for reduction of phosphate in the rock via mechanochemical or "tribochemical" weathering at quartz and calcite/marble inclusions. Artificial reproduction of this mechanism by rubbing quartz rods coated with apatite-phosphate to the point of visible triboluminescence, led to detection of more than 70 000 ng/kg PH3 in the apatite. This reaction pathway may be considered a mechano-chemical analogue of phosphate reduction from lightning or electrical discharges and may contribute to phosphine production via tectonic forces and processing of rocks.

  8. Fourier transform Raman spectroscopy of synthetic and biological calcium phosphates.

    Science.gov (United States)

    Sauer, G R; Zunic, W B; Durig, J R; Wuthier, R E

    1994-05-01

    Fourier-transform (FT) Raman spectroscopy was used to characterize the organic and mineral components of biological and synthetic calcium phosphate minerals. Raman spectroscopy provides information on biological minerals that is complimentary to more widely used infrared methodologies as some infrared-inactive vibrational modes are Raman-active. The application of FT-Raman technology has, for the first time, enabled the problems of high sample fluorescence and low signal-to-noise that are inherent in calcified tissues to be overcome. Raman spectra of calcium phosphates are dominated by a very strong band near 960 cm-1 that arises from the symmetric stretching mode (v1) of the phosphate group. Other Raman-active phosphate vibrational bands are seen at approximately 1075 (v3), 590 (v4), and 435 cm-1 (v2). Minerals containing acidic phosphate groups show additional vibrational modes. The different calcium phosphate mineral phases can be distinguished from one another by the relative positions and shapes of these bands in the Raman spectra. FT-Raman spectra of nascent, nonmineralized matrix vesicles (MV) show a distinct absence of the phosphate v1 band even though these structures are rich in calcium and phosphate. Similar results were seen with milk casein and synthetic Ca-phosphatidyl-serine-PO4 complexes. Hence, the phosphate and/or acidic phosphate ions in these noncrystalline biological calcium phosphates is in a molecular environment that differs from that in synthetic amorphous calcium phosphate. In MV, the first distinct mineral phase to form contained acidic phosphate bands similar to those seen in octacalcium phosphate. The mineral phase present in fully mineralized MV was much more apatitic, resembling that found in bones and teeth.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. User participation in implementation

    DEFF Research Database (Denmark)

    Fleron, Benedicte; Rasmussen, Rasmus; Simonsen, Jesper

    2012-01-01

    Systems development has been claimed to benefit from user participation, yet user participation in implementation activities may be more common and is a growing focus of participatory-design work. We investigate the effect of the extensive user participation in the implementation of a clinical...... experienced more uncertainty and frustration than management and non-participating staff, especially concerning how to run an implementation process and how to understand and utilize the configuration possibilities of the system. This suggests that user participation in implementation introduces a need...

  10. Phosphate Reduction in Emulsifi ed Meat Products: Impact of Phosphate Type and Dosage on Quality Characteristics

    Directory of Open Access Journals (Sweden)

    Seline Glorieux

    2017-01-01

    Full Text Available Phosphate reduction is of important industrial relevance in the manufacturing of emulsifi ed meat products because it may give rise to a healthier product. The eff ect of seven diff erent phosphate types was tested on the physicochemical and quality characteristics to select the most promising phosphate type for further cooked sausage manufacturing. Next, phosphate mass fraction was gradually reduced. Tetrasodium di- or pyrophosphate (TSPP and sodium tripolyphosphate (STPP increased pH, reduced structural properties, resulted in the highest emulsion stability, lowest cooking loss and had litt le eff ect on hardness. Based on the viscoelastic properties, a minimum mass fraction of 0.06 % TSPP was suffi cient to obtain an acceptable quality product. Rheology proved to be a very useful tool to evaluate the quality of meat products, as it gives insight in the structure of the meat product and especially the functional properties of meat proteins. Based on the obtained results, it can be concluded that the current amount of phosphate added to emulsifi ed meat products can be signifi cantly reduced with minimal loss of product quality.

  11. Phosphate Reduction in Emulsified Meat Products: Impact of Phosphate Type and Dosage on Quality Characteristics.

    Science.gov (United States)

    Glorieux, Seline; Goemaere, Olivier; Steen, Liselot; Fraeye, Ilse

    2017-09-01

    Phosphate reduction is of important industrial relevance in the manufacturing of emulsified meat products because it may give rise to a healthier product. The effect of seven different phosphate types was tested on the physicochemical and quality characteristics to select the most promising phosphate type for further cooked sausage manufacturing. Next, phosphate mass fraction was gradually reduced. Tetrasodium di- or pyrophosphate (TSPP) and sodium tripolyphosphate (STPP) increased pH, reduced structural properties, resulted in the highest emulsion stability, lowest cooking loss and had little effect on hardness. Based on the viscoelastic properties, a minimum mass fraction of 0.06% TSPP was sufficient to obtain an acceptable quality product. Rheology proved to be a very useful tool to evaluate the quality of meat products, as it gives insight in the structure of the meat product and especially the functional properties of meat proteins. Based on the obtained results, it can be concluded that the current amount of phosphate added to emulsified meat products can be significantly reduced with minimal loss of product quality.

  12. The variable charge of andisols as affected by nanoparticles of rock phosphate and phosphate solubilizing bacteria

    Science.gov (United States)

    Arifin, M.; Nurlaeny, N.; Devnita, R.; Fitriatin, B. N.; Sandrawati, A.; Supriatna, Y.

    2018-02-01

    Andisols has a great potential as agriculture land, however, it has a high phosphorus retention, variable charge characteristics and high value of zero net charge or pH0. The research is aimed to study the effects of nanoparticles of rock phosphate (NPRP) and biofertilizer (phosphate solubilizing bacteria/PSB) on soil pH, pHo (zero point of charge, ZPC) and organic-C in one subgroup of Andisols, namely Acrudoxic Durudands, Ciater Region West Java. The research was conducted from October 2016 to February 2017 in Soil Physics Laboratory and Laboratory of Soil Chemistry and Fertility, Soil Science Department, Faculty of Agriculture, Universitas Padjadjaran. This experiment used a completely randomized factorial design, consisting of two factors and three replications. The first factor was nanoparticles of rock phosphate consist of 4 doses 0; 25; 50 and 75 g/1 kg soil and the second factor was biofertilizer dose consist of g/1 kg soil and without biofertilizer. Total treatment combinations were 8 with 3 replications, so there were 24 experimental plots. The results showed that in general NPRR and biofertilizer will decrease the value of soil pH throughout the incubation periods. There is an interaction between nanoparticles of rock phosphate and biofertilizer in decreasing pHo in the first month of incubation, but after 4-month incubation period, NPRP increased. Interaction between 75 g nanoparticles of rock phosphate with 1 g biofertilizer/1 kg soil in fourth months of incubation decreased soil organic-C to 3.35%.

  13. Serum Phosphate Predicts Early Mortality among Underweight Adults Starting ART in Zambia: A Novel Context for Refeeding Syndrome?

    Directory of Open Access Journals (Sweden)

    John R. Koethe

    2013-01-01

    Full Text Available Background. Low body mass index (BMI at antiretroviral therapy (ART initiation is associated with early mortality, but the etiology is not well understood. We hypothesized that low pretreatment serum phosphate, a critical cellular metabolism intermediate primarily stored in skeletal muscle, may predict mortality within the first 12 weeks of ART. Methods. We prospectively studied 352 HIV-infected adults initiating ART in Lusaka, Zambia to estimate the odds of death for each 0.1 mmol/L decrease in baseline phosphate after adjusting for established predictors of mortality. Results. The distribution of phosphate values was similar across BMI categories (median value 1.2 mmol/L. Among the 145 participants with BMI <18.5 kg/m2, 28 (19% died within 12 weeks. Lower pretreatment serum phosphate was associated with increased mortality (odds ratio (OR 1.24 per 0.1 mmol/L decrement, 95% CI: 1.05 to 1.47; P=0.01 after adjusting for sex, age, and CD4+ lymphocyte count. A similar relationship was not observed among participants with BMI ≥18.5 kg/m2 (OR 0.96, 95% CI: 0.76 to 1.21; P=0.74. Conclusions. The association of low pretreatment serum phosphate level and early ART mortality among undernourished individuals may represent a variant of the refeeding syndrome. Further studies of cellular metabolism in this population are needed.

  14. Effects of education on low-phosphate diet and phosphate binder intake to control serum phosphate among maintenance hemodialysis patients: A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Eunsoo Lim

    2018-03-01

    Full Text Available Background : For phosphate control, patient education is essential due to the limited clearance of phosphate by dialysis. However, well-designed randomized controlled trials about dietary and phosphate binder education have been scarce. Methods : We enrolled maintenance hemodialysis patients and randomized them into an education group (n = 48 or a control group (n = 22. We assessed the patients' drug compliance and their knowledge about the phosphate binder using a questionnaire. Results : The primary goal was to increase the number of patients who reached a calcium-phosphorus product of lower than 55. In the education group, 36 (75.0% patients achieved the primary goal, as compared with 16 (72.7% in the control group (P = 0.430. The education increased the proportion of patients who properly took the phosphate binder (22.9% vs. 3.5%, P = 0.087, but not to statistical significance. Education did not affect the amount of dietary phosphate intake per body weight (education vs. control: -1.18 ± 3.54 vs. -0.88 ± 2.04 mg/kg, P = 0.851. However, the dietary phosphate-to-protein ratio tended to be lower in the education group (-0.64 ± 2.04 vs. 0.65 ± 3.55, P = 0.193. The education on phosphate restriction affected neither the Patient-Generated Subjective Global Assessment score (0.17 ± 4.58 vs. -0.86 ± 3.86, P = 0.363 nor the level of dietary protein intake (-0.03 ± 0.33 vs. -0.09 ± 0.18, P = 0.569. Conclusion : Education did not affect the calcium-phosphate product. Education on the proper timing of phosphate binder intake and the dietary phosphate-to-protein ratio showed marginal efficacy.

  15. Infrared and Raman Spectra of Magnesium Ammonium Phosphate Hexahydrate (Struvite) and its Isomorphous Analogues. VIII. Spectra of Protiated and Partially Deuterated Magnesium Rubidium Phosphate Hexahydrate and Magnesium Thallium Phosphate Hexahydrate.

    Science.gov (United States)

    Soptrajanov, Bojan; Cahil, Adnan; Najdoski, Metodija; Koleva, Violeta; Stefov, Viktor

    2011-09-01

    The infrared and Raman spectra of magnesium rubidium phosphate hexahydrate MgRbPO4 • 6H2O and magnesium thallium phosphate hexahydrate, MgTlPO4 • 6H2O were recorded at room temperature (RT) and the boiling temperature of liquid nitrogen (LNT). To facilitate their analysis, also recorded were the spectra of partially deuterated analogues with varying content of deuterium. The effects of deuteration and those of lowering the temperature were the basis of the conclusions drawn regarding the origin of the observed bands which were assigned to vibrations which are predominantly localized in the water molecules (four crystallographically different types of such molecules exist in the structures) and those with PO43- character. It was concluded that in some cases coupling of phosphate and water vibrations is likely to take place. The appearance of the infrared spectra in the O-H stretching regions of the infrared spectra is explained as being the result of an extensive overlap of bands due to components of the fundamental stretching modes of the H2O units with a possible participation of bands due to second-order transitions. A broad band reminiscent of the B band of the well-known ABC trio characteristic of spectra of substances containing strong hydrogen bonds in their structure was found around 2400 cm-1 in the infrared spectra of the two studied compounds.

  16. Research and engineering assessment of biological solubilization of phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, R.D.; McIlwain, M.E.; Losinski, S.J.; Taylor, D.D.

    1993-03-01

    This research and engineering assessment examined a microbial phosphate solubilization process as a method of recovering phosphate from phosphorus containing ore compared to the existing wet acid and electric arc methods. A total of 860 microbial isolates, collected from a range of natural environments were tested for their ability to solubilize phosphate from rock phosphate. A bacterium (Pseudomonas cepacia) was selected for extensive characterization and evaluation of the mechanism of phosphate solubilization and of process engineering parameters necessary to recover phosphate from rock phosphate. These studies found that concentration of hydrogen ion and production of organic acids arising from oxidation of the carbon source facilitated microbial solubilization of both pure chemical insoluble phosphate compounds and phosphate rock. Genetic studies found that phosphate solubilization was linked to an enzyme system (glucose dehydrogenase). Process-related studies found that a critical solids density of 1% by weight (ore to liquid) was necessary for optimal solubilization. An engineering analysis evaluated the cost and energy requirements for a 2 million ton per year sized plant, whose size was selected to be comparable to existing wet acid plants.

  17. The Oxygen Isotopic Composition of Phosphate: A Tracer for Phosphate Sources and Cycling

    Energy Technology Data Exchange (ETDEWEB)

    Mclaughlin, K. [Southern California Coastal Water Research Project, Costa Mesa, University of California, CA (United States); Young, M. B.; Paytan, A.; Kendall, C. [U.S. Geological Survey, University of California, CA (United States)

    2013-05-15

    Phosphorus (P) is a limiting macro-nutrient for primary productivity and anthropogenic P-loading to aquatic ecosystems is one of the leading causes of eutrophication in many ecosystems throughout the world. Because P has only one stable isotope, traditional isotope techniques are not possible for tracing sources and cycling of P in aquatic systems. However, much of the P in nature is bonded to four oxygen (O) atoms as orthophosphate (PO{sub 4}{sup 3-}). The P-O bonds in orthophosphate are strongly resistant to inorganic hydrolysis and do not exchange oxygen with water without biological mediation (enzyme-mediated recycling). Thus, the oxygen isotopic composition of dissolved inorganic phosphate ({delta}{sup 18}O{sub p}) may be used as a tracer for phosphate sources and cycling in aquatic ecosystems. Recently, several studies have been conducted utilizing {delta}{sup 18}O{sub p} as a tracer for phosphate sources and cycling in various aquatic environments. Specifically, work to date indicates that {delta}{sup 18}O{sub p} is useful for determining sources of phosphate to aquatic systems if these sources have unique isotopic signatures and phosphate cycling within the system is limited compared to input fluxes. In addition, because various processes imprint specific fractionation effects, the {delta}{sup 18}O{sub p} tracer can be utilized to determine the degree of phosphorous cycling and processing through the biomass. This chapter reviews several of these studies and discusses the potential to utilize the {delta}{sup 18}O{sub p} of phosphate in rivers and streams. (author)

  18. Associations between urinary diphenyl phosphate and thyroid function.

    Science.gov (United States)

    Preston, Emma V; McClean, Michael D; Claus Henn, Birgit; Stapleton, Heather M; Braverman, Lewis E; Pearce, Elizabeth N; Makey, Colleen M; Webster, Thomas F

    2017-04-01

    Triphenyl phosphate (TPHP) is a commonly used organophosphate flame retardant and plasticizer with widespread human exposure. Data on health effects of TPHP are limited. Recent toxicological studies suggest TPHP may alter thyroid function. We used repeated measures to assess the temporal variability in urinary concentrations of the TPHP metabolite, diphenyl phosphate (DPHP), and to examine relationships between DPHP concentrations and thyroid hormones. We sampled 51 adults at months 1, 6, and 12 from 2010 to 2011. Urine samples were analyzed for DPHP. Serum samples were analyzed for free and total thyroxine (fT 4 , TT 4 ), total triiodothyronine (TT 3 ), and thyroid stimulating hormone (TSH). We assessed variability in DPHP using intraclass correlation coefficients (ICCs) and kappa statistics. We used linear mixed-effects models to examine associations between DPHP and thyroid hormones. DPHP was detected in 95% of urine samples. Mean DPHP concentrations were 43% higher in women than men. DPHP showed high within-subject variability (ICC range, 0.13-0.39; kappa range, 0.16-0.39). High versus low (≥2.65 vs. <2.65ng/mL) DPHP in all participants was associated with a 0.43μg/dL (95% confidence interval: 0.15, 0.72) increase in mean TT 4 levels. In sex-stratified analyses, high versus low DPHP was associated with a 0.91μg/dL (95% CI: 0.47, 1.36) increase in mean TT 4 in women. The association was attenuated in men (βeta=0.19; 95% CI: -0.15, 0.52). We found no significant associations between DPHP and fT 4 , TT 3 , or TSH. We found evidence that TPHP exposure may be associated with increased TT 4 levels, especially in women. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Dielectric aluminium phosphate thin films. Couches minces dielectriques de phosphate d'aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Daviero, S. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Avinens, C. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Ibanez, A. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Giuntini, J.C. (Lab. Physicochimie des Materiaux Solides, 34 -Montpellier (France)); Philippot, E. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France))

    1993-04-01

    Aluminium phosphate thin films on silicium substrate have been carried out from tributylphosphate and aluminium acetylacetonate precursors in solution through the ''pyrosol'' process. It can be observed a large range of chemical analysis in terms of experimental conditions. These thin films have been characterized by X-ray diffraction and infrared spectrometry. Their electrical characteristics, defined from direct current and alternative current measurements, are quite different to those of the crystallized phosphate and can be explained by P-O and Al-O ''dangling bond'' existence. (orig.).

  20. Reduction of nucleotides by ionizing radiation: uridine 5' phosphate, and cytidine 3' phosphate

    International Nuclear Information System (INIS)

    Box, H.C.; Potter, W.R.; Budzinski, E.E.

    1974-01-01

    Anions formed by the addition of an electron to the uracil base were observed in single crystals of the barium salt of uridine 5' phosphate x irradiated at 4.2 0 K. The hyperfine coupling tensor for the C 6 -H proton was deduced from ENDOR measurements; the principal values are -59.12, -32.92 and -16.24 MHz. Similar measurements were made on single crystals of cytidine 3' phosphate. The principal values for the C 6 -H proton hyperfine coupling in the anion formed on the cytosine base are -59.26, -33.98 and -14.68 MHz. (U.S.)

  1. The reduction of nucleotides by ionizing radiation: uridine 5' phosphate and cytidine 3' phosphate

    International Nuclear Information System (INIS)

    Box, H.C.; Potter, W.R.; Budzinski, E.E.

    1975-01-01

    Anions formed by the addition of an electron to the uracil base were observed in single crystals of the barium salt of uridine 5' phosphate x-irradiated at 4.2 degreeK. The hyperfine coupling tensor for the C 6 --H proton was deduced from ENDOR measurements; the principal values are -59.12, -32.92, and -16.24 MHz. Similar measurements were made on single crystals of cytidine 3' phosphate. The principal values for the C 6 --H proton hyperfine coupling in the anion formed on the cytosine base are -59.26, -33.98, and -14.68 MHz

  2. Public Participation Plan

    International Nuclear Information System (INIS)

    1993-07-01

    The purpose of this Public Participation Plan is to describe the US Department of Energy's (DOE) plan for involving the public in the decision-making process for the Uranium Mill Tailings Remedial Action (UMTRA) Project. The plan describes how the DOE will meet the public participation requirements of the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, as amended, and of the National Environmental Policy Act (NEPA) of 1969. It includes the UMTRA Project Office plans for complying with DOE Order 5440.1D and for implementing the DOE's Public Participation Policy for Environmental Restoration and Waste Management (1992) and Public Participation Guidance for Environmental Restoration and Waste Management (1993)

  3. 31P-Nuclear Magnetic Resonance Determination of Phosphate Compartmentation in Leaves of Reproductive Soybeans (Glycine max L.) as Affected by Phosphate Nutrition 1

    Science.gov (United States)

    Lauer, Michael J.; Blevins, Dale G.; Sierzputowska-Gracz, Hanna

    1989-01-01

    Most leaf phosphorus is remobilized to the seed during reproductive development in soybean. We determined, using 31P-NMR, the effect phosphorus remobilization has on vacuolar inorganic phosphate pool size in soybean (Glycine max [L.] Merr.) leaves with respect to phosphorus nutrition and plant development. Phosphate compartmentation between cytoplasmic and vacuolar pools was observed and followed in intact tissue grown hydroponically, at the R2, R4, and R6 growth stages. As phosphorus in the nutrient solution decreased from 0.45 to 0.05 millimolar, the vacuolar phosphate peak became less prominent relative to cytoplasmic phosphate and hexose monophosphate peaks. At a nutrient phosphate concentration of 0.05 millimolar, the vacuolar phosphate peak was not detectable. At higher levels of nutrient phosphate, as plants progressed from the R2 to the R6 growth stage, the vacuolar phosphate peak was the first to disappear, suggesting that storage phosphate was remobilized to a greater extent than metabolic phosphate. Under suboptimal phosphate nutrition (≤ 0.20 millimolar), the hexose monophosphate and cytoplasmic phosphate peaks declined earlier in reproductive development than when phosphate was present in optimal amounts. Under low phosphate concentrations (0.05 millimolar) cytoplasmic phosphate was greatly reduced. Carbon metabolism was coincidently disrupted under low phosphate nutrition as shown by the appearance of large, prominent starch grains in the leaves. Cytoplasmic phosphate, and leaf carbon metabolism dependent on it, are buffered by vacuolar phosphate until late stages of reproductive growth. Images Figure 4 PMID:16666705

  4. Occupational radiation risks in conveyance of bulk phosphate and potash

    International Nuclear Information System (INIS)

    Grof, Y.; Even, O.; Schlesinger, T.; Margaliot, M.

    1996-01-01

    The issue of occupational ionizing radiation risks encountered in the conveyance and storage of Phosphates and Potash as loose cargo got very minor attention from the national health and occupational safety authorities in the world. In Israel, the Phosphates include an average 100- 150 ppm of Uranium in equilibrium with its daughters, while in Phosphates produced in most other countries the inaction reaches regularly only few ppm up to 50 ppm. Because of the high content of the Uranium in the Phosphate in Israel we must take into consideration the radiological implications involved in the handling of this mineral. The radiological implications of handling Potash are less significant but can not be neglected as we demonstrate bellow In this presentation we will estimate the occupational radiological risks involved in the storing and transportation of Phosphate and Potash. Note, that the main risk in working with Phosphate and Potash is the risk from the dust itself (authors)

  5. Phosphate removal from digested sludge supernatant using modified fly ash.

    Science.gov (United States)

    Xu, Ke; Deng, Tong; Liu, Juntan; Peng, Weigong

    2012-05-01

    The removal of phosphate in digested sludge supernatant by modified coal fly ash was investigated in this study. Modification of the fly ash by the addition of sulfuric acid could significantly enhance its immobilization ability. The experimental results also showed that adsorption of phosphate by the modified fly ash was rapid with the removal percentage of phosphate reaching an equilibrium of 98.62% in less than 5 minutes. The optimum pH for phosphate removal was 9 and the removal percentage increased with increasing adsorbent dosage. The effect of temperature on phosphate removal efficiency was not significant from 20 to 40 degrees C. X-ray diffraction and scanning electron microscope analyses showed that phosphate formed an amorphous precipitate with water-soluble calcium, aluminum, and iron ions in the modified fly ash.

  6. Occupational radiation risks in conveyance of bulk phosphate and potash

    Energy Technology Data Exchange (ETDEWEB)

    Grof, Y; Even, O; Schlesinger, T; Margaliot, M [Israel Atomic Energy Commission, Yavne (Israel). Soreq Nuclear Research Center

    1996-12-01

    The issue of occupational ionizing radiation risks encountered in the conveyance and storage of Phosphates and Potash as loose cargo got very minor attention from the national health and occupational safety authorities in the world. In Israel, the Phosphates include an average 100- 150 ppm of Uranium in equilibrium with its daughters, while in Phosphates produced in most other countries the inaction reaches regularly only few ppm up to 50 ppm. Because of the high content of the Uranium in the Phosphate in Israel we must take into consideration the radiological implications involved in the handling of this mineral. The radiological implications of handling Potash are less significant but can not be neglected as we demonstrate bellow In this presentation we will estimate the occupational radiological risks involved in the storing and transportation of Phosphate and Potash. Note, that the main risk in working with Phosphate and Potash is the risk from the dust itself (authors).

  7. Reducing the cadmium content of crude phosphates and mineral fertilizers

    Energy Technology Data Exchange (ETDEWEB)

    Plessen, H von; Schimmel, G

    1987-10-01

    Crude sedimentary phosphates generally contain cadmium together with traces of other heavy metals. These Cd traces generally end up in fertilizers produced from the crude phosphates. Processes have therefore been developed to separate the Cd from the crude phosphate or from the crude phosphoric acids arising therefrom as intermediates. In this way, the Cd content of the crude phosphate can be reduced to less the 10% of its original value, and to 50% thereof by extractive treatment with acidic calcium nitrate solution. Older calcination processes for crude phosphate have been improved to give residual Cd contents of 10 to 50% at temperatures of 800 to 1000/sup 0/C. Cadmium can be removed almost quantitatively from crude phosphate by means of dialkyl dithiophosphoric acid esters by extraction, binding to adsorbents, or ion flotation. Cadmium can be extracted from crude acids in high yield by long-chained amines. After partial neutralization of the crude acids, precipitation as cadmium sulphide is also possible.

  8. Extent of local participation

    International Nuclear Information System (INIS)

    Albisu, F.

    1977-01-01

    After a brief historical comment on national participation on past nuclear projects, a description is made of the desirable situation to be achieved as regards local content. The reasons, the procedures and the areas for that participation (i.e., the why, how and where) are suggested, as well as the means to promote it. (orig.) [de

  9. Characterizing eParticipation

    DEFF Research Database (Denmark)

    Sanford, Clive Carlton; Rose, Jeremy

    2007-01-01

    that are considered to be highly relevant to eParticipation. We develop a definitional schema that suggests different ways of understanding an emerging research area, and use this schema to identify key academic articles that help to define eParticipation. We adapt Deetz's [(1996). Describing differences...

  10. Children's participation in research

    DEFF Research Database (Denmark)

    Broström professor m.so., Stig

    2012-01-01

    In (post) modern society children are seen as active subjects and participants who have a legitimate basis in the United Nations Convention of the Rights of the Child. As a consequence of this, children are able to play an active role in the 10 planning of/and participation in both education...

  11. Contact Quality in Participation

    DEFF Research Database (Denmark)

    Simonsen, Jesper; Jensen, Olav Storm

    2016-01-01

    We investigate the concept of participation from the perspective of quality of the contact in the communicative interactions between participants. We argue for the need for an academic-personal competence that qualifies the human contact central in all Participatory Design (PD) activities as a way...

  12. Preparation of Porous Calcium Phosphate Bioceramic

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Porous calcium phosphate ceramics were prepared by slip casting and molding method respectively. By these two different methods, different microstructures can be got. By slip casting method, the pore size was 100- 350μm and 20- 80μm; pores were opened, interconnected and ball-like; the grain size was 2- 4 μm.By molding method, the pore size was 100-500 μm and 1-10μm; the grain size was 2-8μm. By slip casting method regular and interconnected pores can be got. By molding method the porosity and strength can be adjusted easily.

  13. Neonatal jaundice and glucose-6-phosphate dehydrogenase

    OpenAIRE

    Leite, Amauri Antiquera [UNESP

    2010-01-01

    A deficiência de glicose-6-fosfato desidrogenase em neonatos pode ser a responsável pela icterícia neonatal. Este comentário científico é decorrente do relato sobre o tema publicado neste fascículo e que preocupa diversos autores de outros países em relação às complicações em neonatos de hiperbilirrubinemia, existindo inclusive proposições de alguns autores em incluir o teste para identificar a deficiência de glicose-6-fosfato desidrogenase nos recém-nascidos.Glucose-6-phosphate dehydrogenase...

  14. Mapping eParticipation

    DEFF Research Database (Denmark)

    Rose, Jeremy; Sanford, Clive Carlton

    2007-01-01

    The emerging research area of eParticipation can be characterized as the study of technology-facilitated citizen participation in (democratic) deliberation and decision-making. Using conventional literature study techniques, we identify 105 articles that are considered to be highly relevant to e......Participation. We develop a definitional schema that suggests different ways of understanding an emerging socio-technical research area and use this schema to map the research contributions identified. This allows us make an initial sketch of the scientific character of the area and its central concerns, theories......, and methods. We extend the analysis to define four central research challenges for the field: understanding technology and participation; the strategic challenge; the design challenge; and the evaluation challenge. This article thus contributes to a developing account of eParticipation, which will help future...

  15. Preparation and characterization of bioceramics produced from calcium phosphate cements

    Energy Technology Data Exchange (ETDEWEB)

    Andriotis, O.; Katsamenis, O.L. [Department of Materials Science, University of Patras, 26504, Patras (Greece); Mouzakis, D.E. [Technological Educational Institute of Larisa, Department of Mechanical Engineering, T.E.I of Larissa, 411 10, Larissa (Greece); Bouropoulos, N. [Foundation for Research and Technology, Hellas, Institute of Chemical Engineering and High Temperature Chemical Processes, FORTH/ICE-HT, P.O. Box 1414, 26504 Rio Patras (Greece)

    2010-03-15

    The present work reports a method for preparing calcium phosphate ceramics by calcination of calcium phosphate cements composed mainly of calcium deficient hydroxyapatite (CDHA). It was found that hardened cements calcinied at temperatures from to 600 to 1300 C were transformed to tricalcium phosphates. Moreover the compressive strength was determined and porosity was estimated as a function of the calcination temperature. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Preparation and Characterization of Porous Calcium Phosphate Bioceramics

    Institute of Scientific and Technical Information of China (English)

    Honglian Dai; Xinyu Wang; Yinchao Han; Xin Jiang; Shipu Li

    2011-01-01

    β-tricalcium phosphate (β-TCP) powder and Na2O-CaO-MgO-P2O5 glass binder were synthesized and mixed, and then the biodegradable porous calcium phosphate ceramics were successfully prepared by foaming and sintering at 850℃. The as-prepared ceramics possess a high porosity with partial three-dimension interconnected macro- and micro-pores. As in vitro experiment testified, the calcium phosphate ceramics (CPCs) has good degradability.

  17. Immobilization of transition metal ions on zirconium phosphate monolayers

    International Nuclear Information System (INIS)

    Melezhik, A.V.; Brej, V.V.

    1998-01-01

    It is shown that ions of transition metals (copper, iron, vanadyl, titanium) are adsorbed on zirconium phosphate monolayers. The zirconium phosphate threshold capacity corresponds to substitution of all protons of hydroxyphosphate groups by equivalent amounts of copper, iron or vanadyl. Adsorption of polynuclear ions is possible in case of titanium. The layered substance with specific surface up to 300 m 2 /g, wherein ultradispersed titanium dioxide particles are intercalirated between zirconium-phosphate layers, is synthesized

  18. Characterization of the denitrifying fraction of phosphate accumulating organisms in biological phosphate removal

    DEFF Research Database (Denmark)

    Meinhold, Jens; Filipe, Carlos D.M.; Daigger, Glen T.

    1999-01-01

    fractions of PAO are performed and compared. This study extends on previously reported results (Kerrn-Jespersen and Henze, 1993) in that the pH was controlled to around pH 7 to assure that phosphate precipitation was minimal, and in the measurement of PHB and PHV. With regards to the latter, the paper also...

  19. Immunoassays for riboflavin and flavin mononucleotide using antibodies specific to d-ribitol and d-ribitol-5-phosphate.

    Science.gov (United States)

    Ravi, G; Venkatesh, Yeldur P

    2017-06-01

    Riboflavin (vitamin B 2 ), a water-soluble vitamin, plays a key role in maintaining human health. Though, numerous methods have been reported for the determination of total riboflavin (TRF) content in foods and biological samples, very few methods are reported for quantifying riboflavin and its coenzymes [flavin mononucleotide (FMN); flavin adenine dinucleotide (FAD)] individually. Recently, we have demonstrated that antibodies specific to d-ribitol and d-ribitol-5-phosphate also recognize riboflavin and FMN, respectively, and not vice-versa. In this study, we have evaluated these two antibodies for the analysis of riboflavin and FMN by indirect competitive ELISA (icELISA) in selected foods and pharmaceuticals. Under the optimal assay conditions, 50% inhibition concentration (IC 50 ) and limit of detection (LOD, IC 10 ) were 3.41ng/mL and 0.02ng/mL for riboflavin, and 7.84ng/mL and 0.24ng/mL for FMN, respectively, with detectable concentration range between 0.1 and 100ng of analytes and riboflavin and FMN) from the same food samples showed variation in their values compared to TRF, and were in good agreement with values obtained from HPLC and AOAC methods. Further, spiking and recovery analysis of food samples and pharmaceuticals showed no significant matrix effects. The immunoassays were validated in terms of accuracy and precision using inter- and intra-assays. The immunoassays developed in this study are sensitive and appears feasible for screening a large number of samples in the quantification of riboflavin and FMN in various biological samples, pharmaceuticals and natural/processed foods. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Determination of radioactivity in Chinese phosphate rock and fertilizer

    International Nuclear Information System (INIS)

    Chen Jingjian; Zhu Yongyi; Yang Juncheng

    1993-01-01

    The presented paper reported the radioactivity of U-238, Ra-226, Th-232 and K-40 in Chinese phosphate rocks by gamma spectrographic analysis during 1985-1990. The results showed that the decay chain of U-238-Ra-226 was the main source of radionuclides in phosphate rocks. The radionuclides in phosphate fertilizer differed from the forms of phosphate fertilizer. U-238 was the most important radionuclide in phosphoric compound fertilizer. The transfer rate of radionuclides was also estimated. (2 figs., 1 tab.)

  1. Aqueous phosphate removal using nanoscale zero-valent iron

    International Nuclear Information System (INIS)

    Almeelbi, Talal; Bezbaruah, Achintya

    2012-01-01

    Nanoscale zero-valent iron (NZVI) particles have been used for the remediation of a wide variety of contaminants. NZVI particles have high reactivity because of high reactive surface area. In this study, NZVI slurry was successfully used for phosphate removal and recovery. Batch studies conducted using different concentrations of phosphate (1, 5, and 10 mg PO 4 3− -P/L with 400 mg NZVI/L) removed ∼96 to 100 % phosphate in 30 min. Efficacy of the NZVI in phosphate removal was found to 13.9 times higher than micro-ZVI (MZVI) particles with same NZVI and MZVI surface area concentrations used in batch reactors. Ionic strength, sulfate, nitrate, and humic substances present in the water affected in phosphate removal by NZVI but they may not have any practical significance in phosphate removal in the field. Phosphate recovery batch study indicated that better recovery is achieved at higher pH and it decreased with lowering of the pH of the aqueous solution. Maximum phosphate recovery of ∼78 % was achieved in 30 min at pH 12. The successful rapid removal of phosphate by NZVI from aqueous solution is expected to have great ramification for cleaning up nutrient rich waters.

  2. Phosphate analysis of natural sausage casings preserved in brines with phosphate additives as inactivating agent - Method validation.

    Science.gov (United States)

    Wijnker, J J; Tjeerdsma-van Bokhoven, J L M; Veldhuizen, E J A

    2009-01-01

    Certain phosphates have been identified as suitable additives for the improvement of the microbial and mechanical properties of processed natural sausage casings. When mixed with NaCl (sodium chloride) and used under specific treatment and storage conditions, these phosphates are found to prevent the spread of foot-and-mouth disease and classical swine fever via treated casings. The commercially available Quantichrom™ phosphate assay kit has been evaluated as to whether it can serve as a reliable and low-tech method for routine analysis of casings treated with phosphate. The outcome of this study indicates that this particular assay kit has sufficient sensitivity to qualitatively determine the presence of phosphate in treated casings without interference of naturally occurring phosphate in salt used for brines in which casings are preserved.

  3. Final report of the FAO/IAEA co-ordinated research project on the use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphate fertilisers, in particular rock phosphates

    International Nuclear Information System (INIS)

    Zapata, F.

    1999-02-01

    Soils in developing countries are often deficient in available P, and therefore require inputs of P fertiliser for optimum plant growth and production of food and fibre. Due to economic considerations, the cost of applying imported or locally produced water-soluble P fertilisers is often more expensive than utilising indigenous phosphate rock. Phosphate rocks show large differences in their suitability for direct application and several factors influence their capability to supply phosphorus to crops. Therefore, quantifying the P availability of soils amended with phosphate rocks in a variety of crop management and environmental conditions in developing countries is imperative for making recommendations on the best type and rate of P fertiliser sources for maximum agronomic and economic benefits. P-32 isotope techniques are very useful for such studies. The background situation of phosphate research and the topics to be investigated using isotope techniques were critically examined in a Consultants Meeting held at the IAEA Headquarters, Vienna, Austria, from 10 to 12 May 1993. For detailed information please refer to IAEA Report CT-1112. Based on the recommendations of this Consultants' Meeting, the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture with the generous support of the French Government decided to implement the Co-ordinated Research Project (CRP) on 'The Use of Nuclear and Related Techniques for Evaluating the Agronomic Effectiveness of Phosphate Fertilisers, in particular Rock Phosphates'. This final report describes the Fourth and Final RCM of the CRP which was held in Vienna, 16-20 November 1998. It also contains a full description of the project and the conclusions and recommendations of the CRP. The programme of the meeting, list of participants, summaries submitted by the participants and list of publications are included as annexes

  4. Final report of the FAO/IAEA co-ordinated research project on the use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphate fertilisers, in particular rock phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, F

    1999-02-01

    Soils in developing countries are often deficient in available P, and therefore require inputs of P fertiliser for optimum plant growth and production of food and fibre. Due to economic considerations, the cost of applying imported or locally produced water-soluble P fertilisers is often more expensive than utilising indigenous phosphate rock. Phosphate rocks show large differences in their suitability for direct application and several factors influence their capability to supply phosphorus to crops. Therefore, quantifying the P availability of soils amended with phosphate rocks in a variety of crop management and environmental conditions in developing countries is imperative for making recommendations on the best type and rate of P fertiliser sources for maximum agronomic and economic benefits. P-32 isotope techniques are very useful for such studies. The background situation of phosphate research and the topics to be investigated using isotope techniques were critically examined in a Consultants Meeting held at the IAEA Headquarters, Vienna, Austria, from 10 to 12 May 1993. For detailed information please refer to IAEA Report CT-1112. Based on the recommendations of this Consultants' Meeting, the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture with the generous support of the French Government decided to implement the Co-ordinated Research Project (CRP) on 'The Use of Nuclear and Related Techniques for Evaluating the Agronomic Effectiveness of Phosphate Fertilisers, in particular Rock Phosphates'. This final report describes the Fourth and Final RCM of the CRP which was held in Vienna, 16-20 November 1998. It also contains a full description of the project and the conclusions and recommendations of the CRP. The programme of the meeting, list of participants, summaries submitted by the participants and list of publications are included as annexes.

  5. Serum Phosphate Predicts Early Mortality among Underweight Adults Starting ART in Zambia: A Novel Context for Refeeding Syndrome?

    Science.gov (United States)

    Koethe, John R.; Blevins, Meridith; Nyirenda, Christopher K.; Kabagambe, Edmond K.; Chiasera, Janelle M.; Shepherd, Bryan E.; Zulu, Isaac; Heimburger, Douglas C.

    2013-01-01

    Background. Low body mass index (BMI) at antiretroviral therapy (ART) initiation is associated with early mortality, but the etiology is not well understood. We hypothesized that low pretreatment serum phosphate, a critical cellular metabolism intermediate primarily stored in skeletal muscle, may predict mortality within the first 12 weeks of ART. Methods. We prospectively studied 352 HIV-infected adults initiating ART in Lusaka, Zambia to estimate the odds of death for each 0.1 mmol/L decrease in baseline phosphate after adjusting for established predictors of mortality. Results. The distribution of phosphate values was similar across BMI categories (median value 1.2 mmol/L). Among the 145 participants with BMI refeeding syndrome. Further studies of cellular metabolism in this population are needed. PMID:23691292

  6. Water diffusion in phosphate-containing hydrogels

    International Nuclear Information System (INIS)

    George, K.A.; Wentrup-Byrne, E.; Hill, D.J.T.; Whittaker, A.K.

    2003-01-01

    An understanding of the kinetics and diffusion of liquids through polymeric hydrogels is critical for the successful design and application of these materials in biomedical field, particularly as controlled drug delivery systems. In this study, the mechanisms of water transport and parameters that describe the diffusion process in crosslinked poly(2-hydroxyethylmethacrylate-co-methyloxyethylene phosphate), poly(HEMA-co-MOEP) polymers were investigated. The copolymerisation of HEMA with MOEP was initiated by γ radiolysis with full conversion of monomer to polymer. The sorption of water into the polymers with 0 - 30 mol% MOEP was monitored gravimetrically over a period of 2 - 3 weeks. This study provided an insight into the diffusion mechanism and showed that the PHEMA hydrogel displayed concentration-independent Fickian diffusion. As the concentration of MOEP in the network increased, the diffusion rate and the rigidity of the network also increased in a linear fashion. NMR imaging was used in conjunction with the gravimetric study to elucidate the transport mechanisms, diffusion coefficients and proportionality constants governing the water diffusion in the phosphate-containing polymers. The hydrogels with 3 - 20 mol% MOEP exhibited exponential concentration-dependent Fickian diffusion and the transport mechanism in the system with 30 mol% MOEP was shown to be anomalous. The systems with greater concentrations of MOEP displayed a high degree of fracturing during water sorption and resulted in the ultimate destruction of the cylindrical geometry

  7. Computational Design of Biomimetic Phosphate Scavengers

    DEFF Research Database (Denmark)

    Gruber, Mathias Felix; Wood, Elizabeth Baker; Truelsen, Sigurd Friis

    2015-01-01

    Phosphorus has long been the target of much research, but in recent years the focus has shifted from being limited only to reducing its detrimental environmental impact, to also looking at how it is linked to the global food security. Therefore, the interest in finding novel techniques for phosph......Phosphorus has long been the target of much research, but in recent years the focus has shifted from being limited only to reducing its detrimental environmental impact, to also looking at how it is linked to the global food security. Therefore, the interest in finding novel techniques...... for phosphorus recovery, as well as improving existing techniques, has increased. In this study we apply a hybrid simulation approach of molecular dynamics and quantum mechanics to investigate the binding modes of phosphate anions by a small intrinsically disordered peptide. Our results confirm...... phosphate could be the starting point of new novel technological approaches toward phosphorus recovery, and they represent an excellent model system for investigating the nature and dynamics of functional de novo designed intrinsically disordered proteins....

  8. Environmental prospects of uranium from mineral phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Schnug, Ewald [Technische Univ. Braunschweig (Germany). Faculty 2 - Life Sciences; Haneklaus, Nils [Stuttgart Univ. (Germany). Inst. fuer Kernenergetik und Energiesysteme

    2012-12-15

    Uranium (U) is a natural resource that is found in rock phosphates (P). Each year farmers apply unwittingly 167 t/yr U to their soils by P fertilisation. If extracted and used for electricity generation with state of the art nuclear power plants this amount of U could cover the energy demand of 2.4 x 10{sup 6} average German households. Otherwise this finite resource is wasted. U from P fertilisers is an uncommon contribution of agriculture to climate protection. Using the key to calculate the CO{sub 2} depending German car tax band, 1 kilogram P would be valued with 1.8 Euro. More than that the extraction of U from rock phosphates is an efficient measure to avoid U entering the food chain. In particular translocation processes in soils of fertiliser-applied U by run-off and leaching which result in the contamination of surface waters and finally drinking water can be impeded efficiently. (orig.)

  9. Glucose-6-Phosphate Dehydrogenase Enhances Antiviral Response through Downregulation of NADPH Sensor HSCARG and Upregulation of NF-κB Signaling

    Directory of Open Access Journals (Sweden)

    Yi-Hsuan Wu

    2015-12-01

    Full Text Available Glucose-6-phosphate dehydrogenase (G6PD-deficient cells are highly susceptible to viral infection. This study examined the mechanism underlying this phenomenon by measuring the expression of antiviral genes—tumor necrosis factor alpha (TNF-α and GTPase myxovirus resistance 1 (MX1—in G6PD-knockdown cells upon human coronavirus 229E (HCoV-229E and enterovirus 71 (EV71 infection. Molecular analysis revealed that the promoter activities of TNF-α and MX1 were downregulated in G6PD-knockdown cells, and that the IκB degradation and DNA binding activity of NF-κB were decreased. The HSCARG protein, a nicotinamide adenine dinucleotide phosphate (NADPH sensor and negative regulator of NF-κB, was upregulated in G6PD-knockdown cells with decreased NADPH/NADP+ ratio. Treatment of G6PD-knockdown cells with siRNA against HSCARG enhanced the DNA binding activity of NF-κB and the expression of TNF-α and MX1, but suppressed the expression of viral genes; however, the overexpression of HSCARG inhibited the antiviral response. Exogenous G6PD or IDH1 expression inhibited the expression of HSCARG, resulting in increased expression of TNF-α and MX1 and reduced viral gene expression upon virus infection. Our findings suggest that the increased susceptibility of the G6PD-knockdown cells to viral infection was due to impaired NF-κB signaling and antiviral response mediated by HSCARG.

  10. Clinical safety and efficacy of implantation of octacalcium phosphate collagen composites in tooth extraction sockets and cyst holes

    Directory of Open Access Journals (Sweden)

    Tadashi Kawai

    2016-09-01

    Full Text Available It was demonstrated that octacalcium phosphate collagen composite achieved notable bone regeneration in bone defects in preclinical studies. On the basis of the research results, an investigator-initiated exploratory clinical trial was conducted after approval from a local Institutional Review Board. This clinical study was performed as a single-arm non-randomized intervention study. Octacalcium phosphate collagen composite was implanted into a total of 10 cases of alveolar bone defects after tooth extractions and cystectomy. Safety assessment was performed in terms of the clinical course and several consecutive laboratory examinations, and sequential radiographs were used for efficacy assessment. All participants uneventfully completed the clinical trial without major problems in their general condition. Postoperative wound swelling was observed, as also commonly seen in tooth extraction or cystectomy. Although no serious liver dysfunction, renal dysfunction, electrolyte imbalance, or abnormal urinalysis results were recognized, the number of white blood cells and C-reactive protein level temporarily increased after the operation. An increase in radiopacity in the octacalcium phosphate collagen composite–implanted site was observed in all cases. Finally, the border between the original bone and the octacalcium phosphate collagen composite–implanted site became indistinguishable. These results suggest that octacalcium phosphate collagen composite could be utilized safely in clinical situations in the future.

  11. Limited Denial of Participation

    Data.gov (United States)

    Department of Housing and Urban Development — A Limited Denial of Participation (LDP) is an action taken by a HUD Field Office or the Deputy Assistant Secretary for Single Family (DASSF) or Multifamily (DASMF)...

  12. Understanding Participation in Programs.

    Science.gov (United States)

    Hanson, Alan L.

    1991-01-01

    Adherence to program planning principles does not guarantee participation. Attention must be paid to characteristics that make a program responsive: target audience, promotion and marketing, competition, and logistics. (SK)

  13. The effect of different phosphate ion concentrations and ph of the phosphate buffer on lipase bioproduction by rhizopus oligosporus

    International Nuclear Information System (INIS)

    Haq, I.; Ali, S.; Awan, U.F.; Javed, W.; Mirza, S.

    2005-01-01

    In the present investigation, we report the effect of phosphate ion concentration and different ph of the phosphate buffer (as diluent) on lipase bioproduction by Rhizopus oligosporus. For this purpose, solid state fermentation was employed. Different agricultural by-products such as wheat bran, rice husk, almond meal, soybean meal and sunflower meal were used as substrate. The maximum lipase activity (72.60 U/g) was observed with the almond meal. Addition of phosphate ions (K/sub 2/HPO/sub 4/) influenced the lipase production. The ph of the phosphate buffer (7.0) was found to be effective for higher yield of lipase. (author)

  14. From spectator to participant

    DEFF Research Database (Denmark)

    Hoffmann, Birgitte; Kofoed, Jens

    The book collects experiences and methods for citizens’ participation in order to strengthen the local Agenda 21 process. 5 different types of methods is presented: Methods of analyses and evaluation, methods of dialogue, methods for action, methods for networking, and finely methods for involving...... local institutions. In the opening part the book deals with fundamental themes in participation processes such as planning of changes and changes and conflicts....

  15. Effect of submarine groundwater discharge containing phosphate on coral calcification

    Science.gov (United States)

    Yasumoto, J.; Yasumoto, K.; Iijima, M.; Nozaki, M.; Asai, K.; Yasumoto, M. H.

    2017-12-01

    It is well known that the anthropogenic eutrophication enriched with various substances including phosphate in coastal waters has resulted in coral degradation. However, to the best of our knowledge, the phosphate threshold value to inhibit the coral calcification has been unclear, due to the unknown mechanisms involved in the inhibition of the calcification by phosphate. In island regions, groundwater is one of the most important clues to transport the nutrients contained in livestock or agricultural wastewaters. However, the actual conditions of coastal pollution with such nutrients have not been understood because of unperceived submarine groundwater discharge (SGD). In this study, to quantify of extremely rapid and localized SGD from Ryukyu limestone aquifer, we investigated the rate and concentration of phosphate of SGD using automated seepage mater in Yoron Island, which is located southern part of Japan. And, to elucidate the inhibition mechanisms for phosphate against coral calcification, we examined its effect on the bottom skeleton formation in primary polyps of Acropora digitifera by using the fluorescence derivatizing reagent having phosphate group (FITC-AA). As a result, the SGD was found to contain 1 to 2 µM of phosphate as much as the concentration in the coastal ground water under agricultural land. Moreover, the amount of phosphate contained in the surface layers of bottom calcareous sands close to the region of SGD were about 5 µmol/g. When the primary polyps were treated with 50 µM of FITC-AA, the bottom skeleton of the primary polyps showed the fluorescence from FITC-AA within a few minutes, suggesting the phosphate binding. Furthermore, when the polyps were treated with 10 µM of FITC-AA, irregular patterns of the elongated skeleton were observed. These results led us to conclude that phosphate is transported via a paracellular pathway to the subcalicoblastic extracellular calcifying medium. These results indicate that the phosphate adsorbed

  16. New Insights into the Cyclic Di-adenosine Monophosphate (c-di-AMP) Degradation Pathway and the Requirement of the Cyclic Dinucleotide for Acid Stress Resistance in Staphylococcus aureus.

    Science.gov (United States)

    Bowman, Lisa; Zeden, Merve S; Schuster, Christopher F; Kaever, Volkhard; Gründling, Angelika

    2016-12-30

    Nucleotide signaling networks are key to facilitate alterations in gene expression, protein function, and enzyme activity in response to diverse stimuli. Cyclic di-adenosine monophosphate (c-di-AMP) is an important secondary messenger molecule produced by the human pathogen Staphylococcus aureus and is involved in regulating a number of physiological processes including potassium transport. S. aureus must ensure tight control over its cellular levels as both high levels of the dinucleotide and its absence result in a number of detrimental phenotypes. Here we show that in addition to the membrane-bound Asp-His-His and Asp-His-His-associated (DHH/DHHA1) domain-containing phosphodiesterase (PDE) GdpP, S. aureus produces a second cytoplasmic DHH/DHHA1 PDE Pde2. Although capable of hydrolyzing c-di-AMP, Pde2 preferentially converts linear 5'-phosphadenylyl-adenosine (pApA) to AMP. Using a pde2 mutant strain, pApA was detected for the first time in S. aureus, leading us to speculate that this dinucleotide may have a regulatory role under certain conditions. Moreover, pApA is involved in a feedback inhibition loop that limits GdpP-dependent c-di-AMP hydrolysis. Another protein linked to the regulation of c-di-AMP levels in bacteria is the predicted regulator protein YbbR. Here, it is shown that a ybbR mutant S. aureus strain has increased acid sensitivity that can be bypassed by the acquisition of mutations in a number of genes, including the gene coding for the diadenylate cyclase DacA. We further show that c-di-AMP levels are slightly elevated in the ybbR suppressor strains tested as compared with the wild-type strain. With this, we not only identified a new role for YbbR in acid stress resistance in S. aureus but also provide further insight into how c-di-AMP levels impact acid tolerance in this organism. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Methylation-mediated deamination of 5-methylcytosine appears to give rise to mutations causing human inherited disease in CpNpG trinucleotides, as well as in CpG dinucleotides

    Directory of Open Access Journals (Sweden)

    Cooper David N

    2010-08-01

    Full Text Available Abstract The cytosine-guanine (CpG dinucleotide has long been known to be a hotspot for pathological mutation in the human genome. This hypermutability is related to its role as the major site of cytosine methylation with the attendant risk of spontaneous deamination of 5-methylcytosine (5mC to yield thymine. Cytosine methylation, however, also occurs in the context of CpNpG sites in the human genome, an unsurprising finding since the intrinsic symmetry of CpNpG renders it capable of supporting a semi-conservative model of replication of the methylation pattern. Recently, it has become clear that significant DNA methylation occurs in a CpHpG context (where H = A, C or T in a variety of human somatic tissues. If we assume that CpHpG methylation also occurs in the germline, and that 5mC deamination can occur within a CpHpG context, then we might surmise that methylated CpHpG sites could also constitute mutation hotspots causing human genetic disease. To test this postulate, 54,625 missense and nonsense mutations from 2,113 genes causing inherited disease were retrieved from the Human Gene Mutation Database http://www.hgmd.org. Some 18.2 per cent of these pathological lesions were found to be C → T and G → A transitions located in CpG dinucleotides (compatible with a model of methylation-mediated deamination of 5mC, an approximately ten-fold higher proportion than would have been expected by chance alone. The corresponding proportion for the CpHpG trinucleotide was 9.9 per cent, an approximately two-fold higher proportion than would have been expected by chance. We therefore estimate that ~5 per cent of missense/nonsense mutations causing human inherited disease may be attributable to methylation-mediated deamination of 5mC within a CpHpG context.

  18. Standard characterization of phosphate rock samples from the FAO/IAEA phosphate project

    International Nuclear Information System (INIS)

    Binh, Truong; Zapata, F.

    2002-01-01

    Phosphate rocks (PR) are phosphate-bearing minerals that vary widely in their inherent characteristics and consequently their agronomic potential. In the framework of a FAO/IAEA networked research project, the evaluation of the agronomic effectiveness of natural and modified PR products under a variety of soil climate and crop management conditions was carried out. The characterization of phosphate rocks is the first and essential step in evaluating their suitability for direct application. If several PR sources are utilized, standardized methods should be used for comparison purposes to determine their agronomic potential. This paper describes the standard characterization of phosphate rock products utilized in the project, in particular the mineralogical and crystallographic analyses, physical analyses, chemical composition and solubility in conventional reagents. A total of 28 phosphate rock samples from 15 countries were collected and analyzed in specialized laboratories. The data on mineralogy, chemical composition and solubility in conventional reagents are closely interrelated. An arbitrary classification of the reactivity of the PR samples was made based on the solubility indices in conventional reagents. On another hand, the results of the crystallographic parameters, calculated indices of absolute solubility, specific surface and porosity reflect the variability of the physical state and the sample pre-conditioning treatment of the analyzed products. A proper characterization of phosphate rock samples should provide the maximum of basic information that can be obtained in a cost-effective manner in normal chemical laboratories. Based on the results of this characterization, the following determinations are recommended: a description of the sample, major elemental (total P, Ca, Mg) composition, solubility in conventional reagents (neutral ammonium citrate, citric and formic acid) and particle size analysis. The classification of PR samples for direct

  19. D-Ribulose 5-Phosphate 3-Epimerase: Functional and Structural Relationships to Members of the Ribulose-Phosphate Binding (beta/alpha)8-Barrel Superfamily

    Energy Technology Data Exchange (ETDEWEB)

    Akana,J.; Federov, A.; Federov, E.; Novak, W.; Babbitt, P.; Almo, S.; Gerlt, J.

    2006-01-01

    The 'ribulose phosphate binding' superfamily defined by the Structural Classification of Proteins (SCOP) database is considered the result of divergent evolution from a common ({beta}/{alpha}){sub 8}-barrel ancestor. The superfamily includes D-ribulose 5-phosphate 3-epimerase (RPE), orotidine 5'-monophosphate decarboxylase (OMPDC), and 3-keto-L-gulonate 6-phosphate decarboxylase (KGPDC), members of the OMPDC suprafamily, as well as enzymes involved in histidine and tryptophan biosynthesis that utilize phosphorylated metabolites as substrates. We now report studies of the functional and structural relationships of RPE to the members of the superfamily. As suggested by the results of crystallographic studies of the RPEs from rice and Plasmodium falciparum, the RPE from Streptococcus pyogenes is activated by Zn{sup 2+} which binds with a stoichiometry of one ion per polypeptide. Although wild type RPE has a high affinity for Zn{sup 2+} and inactive apoenzyme cannot be prepared, the affinity for Zn{sup 2+} is decreased by alanine substitutions for the two histidine residues that coordinate the Zn{sup 2+} ion (H34A and H67A); these mutant proteins can be prepared in an inactive, metal-free form and activated by exogenous Zn{sup 2+}. The crystal structure of the RPE was solved at 1.8 Angstroms resolution in the presence of D-xylitol 5-phosphate, an inert analogue of the D-xylulose 5-phosphate substrate. This structure suggests that the 2,3-enediolate intermediate in the 1,1-proton transfer reaction is stabilized by bidentate coordination to the Zn{sup 2+} that also is liganded to His 34, Asp 36, His 67, and Asp 176; the carboxylate groups of the Asp residues are positioned also to function as the acid/base catalysts. Although the conformation of the bound analogue resembles those of ligands bound in the active sites of OMPDC and KGPDC, the identities of the active site residues that coordinate the essential Zn{sup 2+} and participate as acid/base catalysts

  20. Hybrid calcium phosphate coatings for implants

    Science.gov (United States)

    Malchikhina, Alena I.; Shesterikov, Evgeny V.; Bolbasov, Evgeny N.; Ignatov, Viktor P.; Tverdokhlebov, Sergei I.

    2016-08-01

    Monophasic biomaterials cannot provide all the necessary functions of bones or other calcined tissues. It is necessary to create for cancer patients the multiphase materials with the structure and composition simulating the natural bone. Such materials are classified as hybrid, obtained by a combination of chemically different components. The paper presents the physical, chemical and biological studies of coatings produced by hybrid technologies (HT), which combine primer layer and calcium phosphate (CaP) coating. The first HT type combines the method of vacuum arc titanium primer layer deposition on a stainless steel substrate with the following micro-arc oxidation (MAO) in phosphoric acid solution with addition of calcium compounds to achieve high supersaturated state. MAO CaP coatings feature high porosity (2-8%, pore size 5-7 µm) and surface morphology with the thickness greater than 5 µm. The thickness of Ti primer layer is 5-40 µm. Amorphous MAO CaP coating micro-hardness was measured at maximum normal load Fmax = 300 mN. It was 3.1 ± 0.8 GPa, surface layer elasticity modulus E = 110 ± 20 GPa, roughness Ra = 0.9 ± 0.1 µm, Rz = 7.5 ± 0.2 µm, which is less than the titanium primer layer roughness. Hybrid MAO CaP coating is biocompatible, able to form calcium phosphates from supersaturated body fluid (SBF) solution and also stimulates osteoinduction processes. The second HT type includes the oxide layer formation by thermal oxidation and then CaP target radio frequency magnetron sputtering (RFMS). Oxide-RFMS CaP coating is a thin dense coating with good adhesion to the substrate material, which can be used for metal implants. The RFMS CaP coating has thickness 1.6 ± 0.1 µm and consists of main target elements calcium and phosphorus and Ca/P ratio 2.4. The second HT type can form calcium phosphates from SBF solution. In vivo study shows that hybrid RFMS CaP coating is biocompatible and produces fibrointegration processes.

  1. Mercury stabilization in chemically bonded phosphate ceramics

    International Nuclear Information System (INIS)

    Wagh, A. S.; Singh, D.; Jeong, S. Y.

    2000-01-01

    Mercury stabilization and solidification is a significant challenge for conventional stabilization technologies. This is because of the stringent regulatory limits on leaching of its stabilized products. In a conventional cement stabilization process, Hg is converted at high pH to its hydroxide, which is not a very insoluble compound; hence the preferred route for Hg sulfidation to convert it into insoluble cinnabar (HgS). Unfortunately, efficient formation of this compound is pH-dependent. At a high pH, one obtains a more soluble Hg sulfate, in a very low pH range, insufficient immobilization occurs because of the escape of hydrogen sulfide, while efficient formation of HgS occurs only in a moderately acidic region. Thus, the pH range of 4 to 8 is where stabilization with Chemically Bonded Phosphate Ceramics (CBPC) is carried out. This paper discusses the authors experience on bench-scale stabilization of various US Department of Energy (DOE) waste streams containing Hg in the CBPC process. This process was developed to treat DOE's mixed waste streams. It is a room-temperature-setting process based on an acid-base reaction between magnesium oxide and monopotassium phosphate solution that forms a dense ceramic within hours. For Hg stabilization, addition of a small amount ( 2 S or K 2 S is sufficient in the binder composition. Here the Toxicity Characteristic Leaching Procedure (TCLP) results on CBPC waste forms of surrogate waste streams representing secondary Hg containing wastes such as combustion residues and Delphi DETOXtrademark residues are presented. The results show that although the current limit on leaching of Hg is 0.2 mg/L, the results from the CBPC waste forms are at least one order lower than this stringent limit. Encouraged by these results on surrogate wastes, they treated actual low-level Hg-containing mixed waste from their facility at Idaho. TCLP results on this waste are presented here. The efficient stabilization in all these cases is

  2. Phosphate retention by soil in relation to waste disposal

    NARCIS (Netherlands)

    Beek, J.

    1979-01-01

    The disposal of large amounts of domestic sewage water and liquid manure, both containing dissolved phosphates, is often problematic. Discharge of these into (shallow and standing) surface waters is highly undesirable, as phosphate is considered to be one of the prime causes of eutrophication. If,

  3. Development of a fully injectable calcium phosphate cement

    Indian Academy of Sciences (India)

    Permanent link: https://www.ias.ac.in/article/fulltext/boms/026/04/0415-0422. Keywords. Calcium phosphate cements; hydroxyapatite; bioceramics; bone substitute; orthopedic; dental. Abstract. A study on the development of a fully injectable calcium phosphate cement for orthopedic and dental applications is presented.

  4. Radiological impacts of uranium recovery in the phosphate industry

    International Nuclear Information System (INIS)

    Ryan, M.T.

    1981-01-01

    This article characterizes the occupational and public radiological health impacts associated with phosphate mining and milling. These impacts are related to the phosphate industry's uranium production potential and are compared with those associated with conventional uranium mining and milling. The radiological impacts resulting from occupational and nonoccupational exposures are assessed. Occupational exposures in phosphate facilities are compared to background exposures and radiological population dose assessments, which characterize important radionuclides and exposure pathways. The following conclusions were reached: (1) public consequences of phosphate mining will occur whether or not uranium is recovered as a by-product, (2) radiological consequences of phosphate mining may be comparable to those associated with uranium mining and milling per unit uranium production, (3) radiological impacts via surface waterways and crops fertilized with uranium-bearing phosphates are of minor consequence, and (4) major radiological public health problems associated with phosphate mining are related to radon and radon progeny exposures in structures built on reclaimed lands or with phosphate mining residues, although the magnitudes of these impacts are difficult to evaluate with current data

  5. Removal of phosphate and nitrate from aqueous solution using ...

    African Journals Online (AJOL)

    The aim of the present study was the removal of phosphate and nitrate by sodium alginate seagrass (Cymodocea rotundata) beads from aqueous solutions. The adsorption characteristics of phosphate and nitrate on the seagrass beads were optimized under different operational parameters like adsorbent dosage, initial ...

  6. Engineering potato starch with a higher phosphate content

    NARCIS (Netherlands)

    Xu, Xuan; Huang, Xing Feng; Visser, Richard G.F.; Trindade, Luisa M.

    2017-01-01

    Phosphate esters are responsible for valuable and unique functionalities of starch for industrial applications. Also in the cell phosphate esters play a role in starch metabolism, which so far has not been well characterized in storage starch. Laforin, a human enzyme composed of a

  7. Biotemplate synthesis of monodispersed iron phosphate hollow microspheres

    International Nuclear Information System (INIS)

    Cao Feng; Li Dongxu

    2010-01-01

    Monodispersed iron phosphate hollow microspheres with a high degree of crystallization were prepared through a facile in situ deposition method using rape pollen grains as a biotemplate. The functional group on the surface of the pollen grains could adsorb Fe 3+ , which provided the nucleation sites for growth of iron phosphate nanoparticles. After being sintered at 600 deg. C for 10 h, the pollen grains were removed and iron phosphate hollow microspheres were obtained. A scanning electron microscope and x-ray diffraction were applied to characterize the morphology and crystalline structure of the pollen grains, iron phosphate-coated pollen grains and iron phosphate hollow microspheres. Differential scanning calorimetry and thermogravity analyses were performed to investigate the thermal behavior of the iron phosphate-coated pollen grains during the calcinations. Energy dispersive spectroscopy and Fourier transform infrared spectroscopy were utilized to investigate the interaction between the pollen grains and iron phosphate. The effect of the pollen wall on the surface morphology of these iron phosphate hollow microspheres was also proven in this work.

  8. Biotemplate synthesis of monodispersed iron phosphate hollow microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Cao Feng; Li Dongxu, E-mail: dongxuli@njut.edu.c [College of Materials Science and Engineering, Nanjing University of Technology, Jiangsu Nanjing 210009 (China)

    2010-03-15

    Monodispersed iron phosphate hollow microspheres with a high degree of crystallization were prepared through a facile in situ deposition method using rape pollen grains as a biotemplate. The functional group on the surface of the pollen grains could adsorb Fe{sup 3+}, which provided the nucleation sites for growth of iron phosphate nanoparticles. After being sintered at 600 deg. C for 10 h, the pollen grains were removed and iron phosphate hollow microspheres were obtained. A scanning electron microscope and x-ray diffraction were applied to characterize the morphology and crystalline structure of the pollen grains, iron phosphate-coated pollen grains and iron phosphate hollow microspheres. Differential scanning calorimetry and thermogravity analyses were performed to investigate the thermal behavior of the iron phosphate-coated pollen grains during the calcinations. Energy dispersive spectroscopy and Fourier transform infrared spectroscopy were utilized to investigate the interaction between the pollen grains and iron phosphate. The effect of the pollen wall on the surface morphology of these iron phosphate hollow microspheres was also proven in this work.

  9. Osteogenecity of octacalcium phosphate coatings applied on porous metal implants

    NARCIS (Netherlands)

    Barrère, F.; van der Valk, Chantal M.; Dalmeijer, Remco A.J.; Meijer, Gert; van Blitterswijk, Clemens; de Groot, K.; Layrolle, Pierre

    2003-01-01

    The biomimetic route allows the homogeneous deposition of calcium phosphate (Ca-P) coatings on porous implants by immersion in simulated physiologic solution. In addition, various Ca-P phases, such as octacalcium phosphate (OCP) or bone-like carbonated apatite (BCA), which are stable only at low

  10. Aluminum and iron contents in phosphate treated swamp rice farm ...

    African Journals Online (AJOL)

    In 2006 aluminum and iron contents were determined in phosphate treated swamp rice farm of Mbiabet, Akwa Ibom State. The objectives were to determine the aluminum and iron contents, the effect of drying, phosphate and lime application in an acid sulphate soil grown to rice in Nigeria. The soil samples used were ...

  11. Evaluation methods used for phosphate-solubilizing bacteria ...

    African Journals Online (AJOL)

    This work aimed to evaluate the different selection methods and select inorganic phosphorus-solubilizing bacteria as potential plant-growth promoters. Bacterial isolates obtained from sugarcane roots and soil were tested using solid growth media containing bicalcium phosphate and Irecê Apatite ground rock phosphate as ...

  12. Chemistry Misconceptions Associated with Understanding Calcium and Phosphate Homeostasis

    Science.gov (United States)

    Cliff, William H.

    2009-01-01

    Successful learning of many aspects in physiology depends on a meaningful understanding of fundamental chemistry concepts. Two conceptual diagnostic questions measured student understanding of the chemical equilibrium underlying calcium and phosphate homeostasis. One question assessed the ability to predict the change in phosphate concentration…

  13. Effect of nitrogen and phosphate limitation on utilization of bitumen ...

    African Journals Online (AJOL)

    The degradation of bitumen was found to be associated with the production of carbon (IV) oxide, natural gas and oil. As a result of using nitrogen limited and phosphate limited media, 1750 and 1250 cm3 of gas and 0.95 and 0.85 g/l of oil were obtained respectively. Nitrogen and phosphate limitation have profound effect on ...

  14. Effect of humic substances on the precipitation of calcium phosphate

    Institute of Scientific and Technical Information of China (English)

    SONG Yong-hui; Hermann H. HAHN; Erhard HOFFMANN; Peter G. WEIDLER

    2006-01-01

    For phosphorus (P) recovery from wastewater, the effect of humic substances (HS) on the precipitation of calcium phosphate was studied. Batch experiments of calcium phosphate precipitation were undertaken with synthetic water that contained 20 mg/L phosphate (as P) and 20 mg/L HS (as dissolved organic carbon, DOC) at a constant pH value in the range of 8.0-10.0. The concentration variations of phosphate, calcium (Ca) and HS were measured in the precipitation process; the crystalline state and compositions of the precipitates were analysed by powder X-ray diffraction (XRD) and chemical methods, respectively. It showed that at solution pH 8.0, the precipitation rate and removal efficiency of phosphate were greatly reduced by HS, but at solution pH ≥9.0,the effect of HS was very small. The Ca consumption for the precipitation of phosphate increased when HS was added; HS was also removed from solution with the precipitation of calcium phosphate. At solution pH 8.0 and HS concentrations ≤ 3.5 mg/L, and at pH ≥ 9.0 and HS concentrations ≤ 10 mg/L, the final precipitates were proved to be hydroxyapatite (HAP) by XRD. The increases of solution pH value and initial Ca/P ratio helped reduce the influence of HS on the precipitation of phosphate.

  15. Interaction between calcium and phosphate adsorption on goethite

    NARCIS (Netherlands)

    Rietra, R.P.J.J.; Hiemstra, T.; Riemsdijk, van W.H.

    2001-01-01

    Quantitatively, little is known about the ion interaction processes that are responsible for the binding of phosphate in soil, water, and sediment, which determine the bioavailability and mobility of phosphate. Studies have shown that metal hydroxides are often responsible for the binding of PO4 in

  16. Cerebrospinal Fluid Phosphate in Delirium after Hip Fracture

    Directory of Open Access Journals (Sweden)

    Ane-Victoria Idland

    2017-09-01

    Full Text Available Aims: Phosphate is essential for neuronal activity. We aimed to investigate whether delirium is associated with altered phosphate concentrations in cerebrospinal fluid (CSF and serum. Methods: Seventy-seven patients with hip fracture were assessed for delirium before and after acute surgery. Prefracture dementia was diagnosed by an expert panel. Phosphate was measured in CSF obtained immediately before spinal anesthesia (n = 77 and in serum (n = 47. CSF from 23 cognitively healthy elderly patients undergoing spinal anesthesia was also analyzed. Results: Hip fracture patients with prevalent delirium had higher CSF phosphate concentrations than those without delirium (median 0.63 vs. 0.55 mmol/L, p = 0.001. In analyses stratified on dementia status, this difference was only significant in patients with dementia. Serum phosphate was ∼1 mmol/L; there was no association between serum phosphate concentration and delirium status. CSF phosphate did not correlate with serum levels. Conclusion: Patients with delirium superimposed on dementia have elevated phosphate levels.

  17. Mineral phosphate solubilizing bacterial community in agro-ecosystem

    African Journals Online (AJOL)

    Mineral phosphate solubilizing bacterial community in agro-ecosystem. N Saha, S Biswas. Abstract. The present communication deals with the assessment of phosphate solubilizing bacterial community structure across artificially created fertility gradient with regards to N, P and K status of soil in the experimental site.

  18. Influence of octacalcium phosphate coating on osteoinductive properties of biomaterials

    NARCIS (Netherlands)

    Habibovic, Pamela; van der Valk, C.M.; van Blitterswijk, Clemens; de Groot, K.

    2004-01-01

    In this study, we investigated the influence of octacalcium phosphate (OCP) coating on osteoinductive behaviour of the biomaterials. Porous titanium alloy (Ti6Al4V), hydroxyapatite (HA), biphasic calcium phosphate (BCP) and polyethylene glyco terephtalate/polybuthylene terephtalate (PEGT–PBT)

  19. Phosphate adsorption using modified iron oxide-based sorbents

    Science.gov (United States)

    Phosphate RemovalThis dataset is associated with the following publication:Lalley , J., C. Han , G. RamMohan , T. Speth , J. Garland , M. Nadagouda , and D. Dionysiou. Phosphate Removal using Modified Bayoxide®E33 Adsorption Media. WATER RESEARCH. Elsevier Science Ltd, New York, NY, USA, issue}: 96-107, (2015).

  20. Uranium determination in phosphatized materials by drop electrode polarography

    International Nuclear Information System (INIS)

    Sequeira, F.M.C. de; Abrao, A.

    1987-01-01

    An uranium determination procedure in phosphate rocks and crude phosphoric acid is outlined polarography is used. Uranium is previously separedted by extraction with tri-n-byte phosphate 10%-petroleum ether using aluminium nitrate as salting out agent. (M.L.J.) [pt

  1. From understanding to participation

    DEFF Research Database (Denmark)

    Raudaskoski, Pirkko Liisa

    2013-01-01

    The paper presents some methodological considerations around the topic of the AFinLA 2012 Autumn Symposium: Multimodal discourses of participation. The aim is to shed theoretical and analytical light on embodied participation in material settings. The research is placed in a relational perspective...... in which entities (for example, the world, culture, society, organization and identities) emerge through entangled, layered practices in concrete circumstances. Understanding is not treated as a philosophical puzzle or as a purely linguistic phenomenon. Rather, it is conceptualized as an embodied......, multimodal process in which language together with bodily senses (vision, hearing, touch, smell and taste) and a sense of place contribute to a phenomenon being recognized (as shared). Participation can result in inclusion or exclusion, a claim which is discussed with the help of a pilot study from...

  2. eParticipation Research

    DEFF Research Database (Denmark)

    Medaglia, Rony

    2012-01-01

    Research on the use of information technology to support democratic decision-making (eParticipation) is experiencing ongoing growth, stimulated by an increasing attention from both practitioner and research communities. This study provides the first longitudinal analysis of the development of the e......Participation field based on a shared framework, capturing the directions that the research field of eParticipation is taking in recent developments. Drawing on a literature search covering the period from April 2006 to March 2011, this study identifies, analyzes, and classifies 122 research articles within...... also suggests new analytical categories of research. Drawing on the analysis, inputs for a research agenda are suggested. These include the need to move beyond a technological perspective, encouraging the ongoing shift of research focus from government to citizens and other stakeholders, and the need...

  3. Participation under Compulsion

    Directory of Open Access Journals (Sweden)

    Franco Rau

    2010-12-01

    Full Text Available Benefits of Social Software in teaching and learning are a research subject of great interest, especially in higher education. Even though the opportunities to encourage students’ participation are promising, there is a neglected area we intend to illuminate: heteronomy. Compulsion and external control are used to foster participation. In our study we examined 16 international evaluation and research papers which describe the implementation of Social Software to enhance students’ participation within courses. Several contradictions within these descriptions were revealed. One may realise that students pretend to “play the game” due to assessment regulations. The tension between students’ self-responsibility and external control in education needs to be reflected systematically.

  4. Public Participation GIS

    DEFF Research Database (Denmark)

    Hansen, Henning Sten

    2004-01-01

    The protection and enhancement of the environment is the main aim of most environmental planning, and the use of geographic information as well as public participation can improve the quality of both the processes and the decisions. The current paper describes the role of web-based geographic...... information in environmental planning and gives an overview over the various approaches to public participation. The current advances in Web-based GIS in many countries contain great possibilities for supporting good governance based on information and knowledge on the one hand and active involvement...... of the citizens on the other hand. One important precondition for success in this field is a well-informed population with access to the Internet. The overall purpose of this paper is to give en overview of how to utilise geographic information and public participation as natural components in environmental...

  5. The participating researcher

    DEFF Research Database (Denmark)

    Hansen, Louise Ejgod

    2014-01-01

    and abilities. The cases will be analyzed with focus on the strategy of participation and the value implications of this for each of them. The second part of the paper will address the role of the researcher as a part of each of these participatory cultural projects as designer, applied researcher, consultant......My paper will focus on the self-reflection of my role as participating researcher in three different art projects all of which have participation as a key element. The paper will begin with a presentation of the three cases: Theatre Talks (Teatersamtaler), Stepping Stones (Trædesten) and Art...... or evaluator. The role of me as a researcher with regard to the development and evaluation of the projects will be analyzed, trying to answer the question: What are the methodological differences between the approaches and how does that affect the research process and results. These differences...

  6. EFFECT OF SODIUM PHOSPHATES ON SELECTED FOOD GRADE BACTERIA

    Directory of Open Access Journals (Sweden)

    Stanislav Kráčmar

    2011-04-01

    Full Text Available The aim of this study was to examine the inhibitory effect in vitro of selected sodium phosphates (under the corporate names Hexa 68, Hexa 70, Trikrystal, FST, Pyro 52, KPS, Didi on selected gram-positive and gram-negative bacteria. Seven different concentrations of each phosphate were used. Sensitivity of the bacterial strains to phosphates was observed in broth supplemented with salts. In vitro was showed a negative effect of various phosphates on growth of selected gram-positive bacteria. Orthophosphates and diphosphates (pyrophosphates did not have significant inhibitory effect on tested bacteria at neutral pH. With the exception of phosphate Trikrystal has not been found in vitro significant inhibitory effects on gram-negative bacteria.doi:10.5219/141

  7. Isolation of phosphate solubiliser fungi from Araza rhizosphere

    International Nuclear Information System (INIS)

    Vera, Diana Fernanda; Perez, Hernando; Valencia Hernando

    2002-01-01

    Araza is an eatable plant, original from the Amazon region, which has been described as a promising species for commercialization (Quevedo 1995). This plant has high productivity even in low content phosphate soil but the presence of phosphate solubilizing microorganisms may contribute to increase this element availability. In this study we report the isolation and characterization of solubilizing fungi processed using the soil washing method, from soil samples were araza is cultivated at two regions in Guaviare, Colombia. Eighteen isolates of fungi capable of solubilizing phosphate were obtained from 2 different sources. The most important species that solubilized phosphate from calcium were Trichoderma aureoviride, Aspergillus aculeatus, Trichoderma strain 1 y Trichoderma strain 2 and for phosphate from iron: Aspergillus oryzae, Paecilomyces strain 3, Gongronella butleri and Fusarium oxysporum

  8. Magnesium-phosphate-glass cements with ceramic-type properties

    Science.gov (United States)

    Sugama, T.; Kukacka, L.E.

    1982-09-23

    Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate, exhibits rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

  9. Magnesium phosphate glass cements with ceramic-type properties

    Science.gov (United States)

    Sugama, Toshifumi; Kukacka, Lawrence E.

    1984-03-13

    Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate exhibiting rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

  10. A Phosphate Starvation-Inducible Ribonuclease of Bacillus licheniformis.

    Science.gov (United States)

    Nguyen, Thanh Trung; Nguyen, Minh Hung; Nguyen, Huy Thuan; Nguyen, Hoang Anh; Le, Thi Hoi; Schweder, Thomas; Jürgen, Britta

    2016-08-28

    The BLi03719 protein of Bacillus licheniformis DSM13 belongs to the most abundant extracellular proteins under phosphate starvation conditions. In this study, the function of this phosphate starvation inducible protein was determined. An amino-acid sequence analysis of the BLi03719-encoding gene showed a high similarity with genes encoding the barnase of Bacillus amyloliquefaciens FZB42 and binase-like RNase of Bacillus pumilus SARF-032. The comparison of the control strain and a BLi03719-deficient strain revealed a strongly reduced extracellular ribonuclease activity of the mutant. Furthermore, this knockout mutant exhibited delayed growth with yeast RNA as an alternative phosphate and carbon source. These results suggest that BLi03719 is an extracellular ribonuclease expressed in B. licheniformis under phosphate starvation conditions. Finally, a BLi03719 mutant showed an advantageous effect on the overexpression of the heterologous amyE gene under phosphate-limited growth conditions.

  11. A study of phosphate absorption by magnesium iron hydroxycarbonate.

    Science.gov (United States)

    Du, Yi; Rees, Nicholas; O'Hare, Dermot

    2009-10-21

    A study of the mechanism of phosphate adsorption by magnesium iron hydroxycarbonate, [Mg(2.25)Fe(0.75)(OH)(6)](CO(3))(0.37).0.65H(2)O over a range of pH has been carried out. The efficiency of the phosphate removal from aqueous solution has been investigated between pH 3-9 and the resulting solid phases have been studied by elemental analysis, XRD, FT-IR, Raman, HRTEM, EDX and solid-state MAS (31)P NMR. The analytical and spectroscopic data suggest that phosphate removal from solution occurs not by anion intercalation of the relevant phosphorous oxyanion (H(2)PO(4)(-) or HPO(4)(2-)) into the LDH but by the precipitation of either an insoluble iron hydrogen phosphate hydrate and/or a magnesium phosphate hydrate.

  12. Uranyl phosphate mineral in Gapyeong area

    International Nuclear Information System (INIS)

    Chung, S.J.

    1980-01-01

    An uranyl phosphate crystal from Gapeong area is studied by means of single crystal x-ray diffraction and electron microscopic qualitative analysis of chemical contents. The crystal is identified as meta-ankoleite which has a unit cell of super structure with a=b=6.99 A, c=17.69 A and space group P4 2 22. There exists some indication in the total fluorescent spectrum of the sample that potassium may be partially substituted by calcium. The chemical formula of this meta-ankoleite may be expressed by Ksub(1-2x)Casub(x)(UO 2 PO 4 ) (H 2 O)sub(3-x). (Author)

  13. Radiation exposure levels in phosphate mining activities

    International Nuclear Information System (INIS)

    Othman, I.; Al-Hushari, M.; Raja, G.

    1992-01-01

    Radon, radon daughter concentration and gamma ray exposure rate were measured at different places in the phosphate mining areas of Syria. The grab sampling method was used. For radon measurements, discrete air samples without progeny were collected over short periods of time, whereas daughters were collected on filter paper. A three-count procedure was used for the measurement of radon daughter concentrations to improve accuracy. The measurements were carried out at 37 locations selected in the mines, factories, offices and homes in the mining area. The sampling was repeated monthly for a full calendar year. Workers and their families were classified in different categories according to the nature of their jobs. The doses were estimated using proper occupancy factors. The dose equivalent from radon daughters varies from 1 mSv.y -1 to a maximum of 10 mSv.y -1 . Radon concentrations vary from 100 Bq.m -3 to several hundreds. (author)

  14. Measurements of natural radioactivity in phosphate fertilizers

    International Nuclear Information System (INIS)

    Ioannides, K.G.; Mertzimekis, T.J.; Papachristodoulou, C.A.; Tzialla, C.E.

    1997-01-01

    The natural radioactivity, mainly due to radium ( 226 Ra), in phosphate fertilizers used in north-western Greece has been measured by γ-spectroscopy. Also radioactivity measurements were performed in soil samples and were compared to samples from undisturbed soils. 226 Ra belongs to the 238 U chain and is the precursor of radon gas ( 222 Rn). The radon concentrations in warehouses, where large quantities of fertilizers are kept, were measured with CR-39 SSNTDs. The radium concentrations in the fertilizers ranged from 0 to 4584 Bq kg -1 and the radon concentrations in warehouses were measured 540-3320 Bq m -3 . The results are discussed from the radiation protection point of view

  15. Study of some properties of zirconium phosphate

    International Nuclear Information System (INIS)

    Prospert, J.

    1963-05-01

    Zirconium phosphate has been studied with a view to using it as an ion exchanger: the first objective was to develop a method of preparation easy to apply and also reproducible. To this end, several tests were carried out varying the molar ratios of phosphorus and of zirconium. Some physical properties such as the diffraction of X-rays were examined. The work then involved certain chemical properties, particularly the percentages of free water and structural water given by the loss on calcination, the Karl-Fisher method and the weight losses by thermogravimetry. Finally an attempts was made to apply the exchanger to the separation of alkaline ions. The static tests showed that the order of fixation of these ions was Cs + > Rb + >> K + > Na + . Tests with columns showed that Na + and K + were easily separable, as was the Rb + -Cs + mixture, this last pair being fairly difficult to dissociate. (author) [fr

  16. Bioavailabilty of deposit phosphates in animal feeding

    International Nuclear Information System (INIS)

    Godoy, Susmira; Chicco, C.F.

    1997-01-01

    In order to evaluate the growth, the absorption and the dynamics of phosphorus and calcium phosphates of high fluorine content , triple superphosphates (TSP) and two sedimentary phosphates Riecito (RIO) and Monte Fresco (MONTE) vs dicalcium phosphate (DICAL), they were carried out two experiments with sheep. In the first one, with a duration of 360 days, the group (six animals) consumed DICAL, and at the 330 day of feeding it was divided in two groups, one under the same treatment and to the other one it was added 500 ppm of fluorine like NaF (DICAL+F). In this experiment the growth was evaluated, and at the end of the period, it was determined the phosphorus and calcium absorption and kinetics, the retention of fluorine in different sources, as well as the bony mineralization. In the second experiment, with a duration of 30 days, the phosphorus absorption and kinetics, as and the retention of fluorine in the sources under study, were determined. In both experiments, for the dynamic studies it was used the isotopic dilution technique, by means of the dosage, through jugular injection, of 200 uCi 3 2P and, for via oral, 200 uCi 4 5Ca. The weight gained (g / animal /day ) was 75, 87, 56 and 53 for DICAL, RIO, MONTE and TSP, respectively, with significant differences (P'0.05) in favor of DICAL and RIO. The true absorption of phosphorus (%), for the fed animals during 30 and 360 days, respectively, was 73 and 76 for DICAL, 40 and 57 for RIO, 36 and 57 for MONTE and, 79 and 71 for TSP, being significantly higher (P'0.05), for both periods, the values of DICAL and TSP. The evaluation of 12 months of absorption of RIVER and MONTE was higher than during the period of 30 days. The absorption of calcium at the 362 days was higher for DICAL and RIO in relation to MONTE and TSP. The addition of fluorine during 30 days didn't affect the calcium and phosphorus absorption. The run time to reach the maximum level of specific activity of calcium in blood was higher for RIO, MONTE

  17. Use of phosphate rocks for sustainable agriculture

    International Nuclear Information System (INIS)

    Zapata, F.; Roy, R.N.

    2004-01-01

    This publication deals with the direct application of phosphate rock (PR) sources to agriculture. Phosphorus (P) is an essential plant nutrient and its deficiency restricts crop yields severely. Tropical and subtropical soils are predominantly acidic, and often extremely P deficient with high P-sorption (fixation) capacities. Therefore, substantial P inputs are required for optimum plant growth and adequate food and fibre production. Manufactured water-soluble P fertilizers such as superphosphates are commonly recommended to correct P deficiencies, but most developing countries import these fertilizers, which are often in limited supply and represent a major outlay for resource-poor farmers. In addition, intensification of agricultural production in these countries necessitates the addition of P not only to increase crop production but also to improve soil P status in order to avoid further soil degradation. Hence, it is imperative to explore alternative P sources. Under certain soil and climate conditions, the direct application of PR, especially where available locally, has proved to be an agronomically and economically sound alternative to the more expensive superphosphates. PR deposits occur worldwide, but few are mined (for use mainly as raw materials to manufacture water-soluble P fertilizers). The Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture initiated a Coordinated Research Project called 'The use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphatic fertilizers, in particular rock phosphates'. This was implemented by institutes of developing and industrialized countries from 1993 to 1998. The results obtained yielded new information on: chemistry of soil P; tests for available soil P; phosphate nutrition of crops; agronomic effectiveness of PR products; and P fertilizer recommendations with particular emphasis on PR use. Within the framework of the integrated plant nutrition systems promoted by

  18. Phagocytosis in phosphate chromium (III) suspensions

    International Nuclear Information System (INIS)

    Cruz-Arencibia, Jorge; Fano Machín, Yoiz; Cruz-Morales, Ahmed; Tamayo Fuente, Radamés; Morín-Zorrilla, José

    2015-01-01

    Phagocytosis in vivo and in vitro of a suspension of chromic phosphate (III) labeled with 51 Cr and 32 P is studied. The radioactive particles dispersed in a media of 2 % gelatin in acetate buffer pH 4-4.5 have a predominant size of 0.8 μm and 5 μm. According with biodistribution experiments in rats after 30 minutes near the 80 % of radioactivity is registered in the liver, probably associated with phagocytosis of the particles by liver Kupffer cells. Is also showed that the suspension particles are phagocytized in vitro by mouse peritoneal macrophages. This facts indicate that the studied suspension have appropriate characteristics to be used in radiosynoviorthesis according to the principal action mechanism described for this procedure, particles phagocytosis by cells present in the inflamed synovium. (author)

  19. Inorganic phosphate uptake in unicellular eukaryotes.

    Science.gov (United States)

    Dick, Claudia F; Dos-Santos, André L A; Meyer-Fernandes, José R

    2014-07-01

    Inorganic phosphate (Pi) is an essential nutrient for all organisms. The route of Pi utilization begins with Pi transport across the plasma membrane. Here, we analyzed the gene sequences and compared the biochemical profiles, including kinetic and modulator parameters, of Pi transporters in unicellular eukaryotes. The objective of this review is to evaluate the recent findings regarding Pi uptake mechanisms in microorganisms, such as the fungi Neurospora crassa and Saccharomyces cerevisiae and the parasite protozoans Trypanosoma cruzi, Trypanosoma rangeli, Leishmania infantum and Plasmodium falciparum. Pi uptake is the key step of Pi homeostasis and in the subsequent signaling event in eukaryotic microorganisms. Biochemical and structural studies are important for clarifying mechanisms of Pi homeostasis, as well as Pi sensor and downstream pathways, and raise possibilities for future studies in this field. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Thermal Decomposition of Nitrated Tributyl Phosphate

    International Nuclear Information System (INIS)

    Paddleford, D.F.; Hou, Y.; Barefield, E.K.; Tedder, D.W.; Abdel-Khalik, S.I.

    1995-01-01

    Contact between tributyl phosphate and aqueous solutions of nitric acid and/or heavy metal nitrate salts at elevated temperatures can lead to exothermic reactions of explosive violence. Even though such operations have been routinely performed safely for decades as an intrinsic part of the Purex separation processes, several so-called ''red oil'' explosions are known to have occurred in the United States, Canada, and the former Soviet Union. The most recent red oil explosion occurred at the Tomsk-7 separations facility in Siberia, in April 1993. That explosion destroyed part of the unreinforced masonry walls of the canyon-type building in which the process was housed, and allowed the release of a significant quantity of radioactive material

  1. Phosphate Solubilizing Bacteria Adaptive to Vinasse

    Directory of Open Access Journals (Sweden)

    Kahar Muzakhar

    2015-06-01

    Full Text Available Microorganisms identified as phosphate solubilizing bacteria (PSB adaptive to vinasse were successfully screened from sugarcane soil from an agriculatural estate in Jatiroto. By conducting a screening on Pikovskaya’s agar medium (PAM, we found that five different isolates were detected as PSB (pvk-5a, pvk-5b, pvk-6b, pvk-7a, and pvk-8a. Of the five isolates only three could be grown and were found to be adaptive to vinasse based medium without any nutrients added (pvk-5a, pvk-5b and pvk-7a. The three isolates were characterized as coccus and Gram negative with no endospores detected. We suggest that these three isolates can be used as biofertilizer agent to support organic farming.

  2. Potential for phosphate mitigation from agricultural runoff by three aquatic macrophytes

    Science.gov (United States)

    Phosphate from agricultural runoff is considered a contributor to eutrophication. Three aquatic macrophyte species, Leersia oryzoides, Typha latifolia, and Sparganium americanum, were investigated for their phosphate mitigation ability. Mesocosms were exposed to flowing phosphate enriched water (1...

  3. Chemistry of tetravalent actinides phosphates. The thorium phosphate-diphosphate as immobilisation matrix of actinides

    International Nuclear Information System (INIS)

    Dacheux, N.

    2002-01-01

    The author presents in this document its scientific works from 1992 to 2001, in order to obtain the enabling to manage scientific and chemical researches at the university Paris Sud Orsay. The first part gives an abstract of the thesis on the characterizations, lixiviation and synthesis of uranium and thorium based phosphate matrix in the framework of the search for a ceramic material usable in the radioactive waste storage. The second part presents briefly the researches realized at the CEA, devoted to a reliable, independent and accurate measure of some isotopes activity. The last part presents the abstracts of researches activities from 1996 to 2001 on the tetravalent actinides phosphates chemistry, the sintering of PDT and solid solutions of PDTU and the kinetic and thermodynamical studies of the PDT dissolution. Many references and some publication in full text are provided. (A.L.B.)

  4. Study of the tributyl phosphate - 30% dodecane solvent; Etude du solvant phosphate tributylique - 30 % dodecane

    Energy Technology Data Exchange (ETDEWEB)

    Leroy, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses. Centre d' Etudes Nucleaires, 92 (France)

    1967-07-01

    This study, originating mainly from a literature survey, gives the principal chemical and physical features of the tributyl-phosphate (TBP) agent diluted at 30 volumes per cent in dodecane. The mixture is a very commonly used extractant in nuclear fuel processing. In this paper, the main following points are reported: -) the components (TBP and diluents) -) the TBP-diluents systems (non-loaded), -) the TBP-diluents-water systems, -) TBP-diluents-water-nitric acid systems, and -) industrial solvents. (author) [French] Cette etude, d'origine bibliographique, regroupe les caracteristiques physico-chimiques essentielles du phosphate tributylique (TBP) dilue a 30% en volume dans du dodecane. Ce melange constitue un agent d'extraction tres utilise dans le traitement des combustibles nucleaires. Les principaux points traites sont les suivants: -) les constituants (TBP et diluants), -) les systemes TBP-diluants non charges, -) les systemes TBP-diluants-eau, -) les systemes TBP-diluants-eau-acide nitrique, et -) les solvants industriels. (auteur)

  5. The antimicrobial activity of as-prepared silver-loaded phosphate glasses and zirconium phosphate

    International Nuclear Information System (INIS)

    Jing, Wang; Jiang, Ji Zhi; Yang, Yang; Yan, Zhao Chun; Yan, Wang Xiao; He, Shui Zhong

    2016-01-01

    The antimicrobial activities of silver-loaded zirconium phosphate (JDG) and silver-loaded phosphate glasses (ZZB) against Escherichia coli were studied. Although the silver content in JDG was higher than that in ZZB, ZZB suspensions showed better antimicrobial property than JDG suspensions, especially at low concentrations. The antimicrobial activity was analyzed using minimum inhibitory concentrations, bacterial inhibition ring tests, and detection of silver ions in the suspensions. Furthermore, the amounts of silver ions in suspensions with/without bacterial cells were analyzed. Results revealed that only a portion of released silver ions could be adsorbed by E. coli cells, which are critical to cell death. The damaged microstructures of E. coli cells observed by transmission electron microscopy may further prove that the adsorbed silver ions play an important role in the antimicrobial process.

  6. The use of phosphates in forestry

    Directory of Open Access Journals (Sweden)

    Tkaczyk Miłosz

    2016-03-01

    Full Text Available Phosphite preparations are now an important alternative in plant protection against new, invasive pathogens of the genus Phytophthora and/or Pythium. It is crucial to intervene when alien, invasive oomycetes are carried to plantations or forest stands and attack fine roots via zoospores. The aim of this paper was to demonstrate the possibility of phosphite application to induce resistance to tree pathogens. Phosphate-based fertilizers have been used successfully in nurseries, where application is relatively easy by means of foliar sprays. the traditional fungicides, which are effective in combating fungi, however, fail to control oomycetes. Instead, they mask the disease, which, in turn, causes serious damage to seedlings after they have been planted in a suitable environment. Moreover, the number of effective fungicides available for forest plant protection has continued to decrease in the last decade. The effectiveness of the chemicals is reduced due to their frequent use and their similarity in terms of the active compound or the mechanism of action. Given the low diversity of active compounds, it is necessary to monitor the development of resistance of pathogens to fungicides by means of molecular biology (sequencing and quantitative PCR. Minimising the undesired side effects of chemicals on both, mycorrhizal fungi and pathogens can be achieved by strict adherence to rigorous security measures and, where possible, frequently changing the active compounds to alternatives such as phosphites. The significance of phosphate and phosphite uptake by trees is still a matter of debate, especially under field conditions. Nevertheless, phosphites are environmentally friendly compounds, which constitute an alternative or complement to the traditional chemicals (in accordance with the Directive on Integrated Plant management.

  7. eParticipation Research

    DEFF Research Database (Denmark)

    Medaglia, Rony

    2011-01-01

    This paper provides an update of the existing eParticipation research state of the art, and a longitudinal analysis of the development of the eParticipation field based on a shared framework of analysis. Drawing on a literature search covering the period from April 2006 to March 2011 included, 123......, sometimes in counterintuitive directions. Drawing on the analysis, the conclusion section provides inputs for a research agenda. These include the need to move beyond a technological perspective, and encouraging the ongoing shift of research focus from government to citizens and other stakeholders....

  8. Participation and power

    DEFF Research Database (Denmark)

    We would like to welcome you to a series of dialogues within the framework of action research (AR) and participatory research (PR), which will be focused on the relationship between participation and power. The basic question in this anthology is ‘What are the possibilities and barriers to partic......We would like to welcome you to a series of dialogues within the framework of action research (AR) and participatory research (PR), which will be focused on the relationship between participation and power. The basic question in this anthology is ‘What are the possibilities and barriers...

  9. The Subjectivity of Participation

    DEFF Research Database (Denmark)

    Nissen, Morten

    of a community of social/youth workers in Copenhagen between 1987 and 2003, who developed a pedagogy through creating collectives and mobilizing young people as participants. The theoretical and practical traditions are combined in a unique methodology viewing research as a contentious modeling of prototypical......What is a 'we' – a collective – and how can we use such communal self-knowledge to help people? This book is about collectivity, participation, and subjectivity – and about the social theories that may help us understand these matters. It also seeks to learn from the innovative practices and ideas...

  10. Unsymmetrical phosphate as extractant for the extraction of nitric acid

    International Nuclear Information System (INIS)

    Gaikwad, R.H.; Jayaram, R.V.

    2016-01-01

    Tri-n-butyl phosphate (TBP) was first used as an extractant in 1944, during Manhattan project for the separation of actinides and further explored by Warf in 1949 for the extraction of Ce(IV) from aqueous nitric acid. TBP was further used as an extractant in the Plutonium Uranium Recovery by Extraction (PUREX) process. To meet the stringent requirements of the nuclear industry TBP has been extensively investigated. In spite of its wide applicability, TBP suffers from various disadvantages such as high aqueous solubility, third phase formation, chemical and radiation degradation leading to the formation of undesired products. It also suffers from incomplete decontamination of the actinides from fission products. Various attempts have been made to overcome the problems associated with TBP by way of using higher homologues of TBP such as Tri-iso amyl phosphate (TiAP), Tri-secondary butyl phosphate (TsBP), Tri amyl phosphate (TAP). It was found that in some cases the results were considerably better than those obtained with TBP for uranium/thorium extraction. The extraction of nitric acid by TBP and its higher homologues which are symmetrical are well documented. However, no solvent has emerged clearly superior than TBP. Here in we report the extraction of nitric acid with neutral unsymmetrical phosphates and study them as extractants for the extraction of nitric acid. Dibutyl secbutyl phosphate, dibutyl pentyl phosphate and dibutyl heptyl phosphate were synthesised for this purpose and the extraction of nitric acid was studied in n-dodecane. The results indicate that the substitution of one of the alkyl groups of the symmetrical phosphate adjacent to the phosphoryl (P=O) group of the phosphate does not have any pronounced effect on the extraction capacity of nitric acid. (author)

  11. The role of Val-265 for flavin adenine dinucleotide (FAD) binding in pyruvate oxidase: FTIR, kinetic, and crystallographic studies on the enzyme variant V265A.

    Science.gov (United States)

    Wille, Georg; Ritter, Michaela; Weiss, Manfred S; König, Stephan; Mäntele, Werner; Hübner, Gerhard

    2005-04-05

    In pyruvate oxidase (POX) from Lactobacillus plantarum, valine 265 participates in binding the cofactor FAD and is responsible for the strained conformation of its isoalloxazine moiety that is visible in the crystal structure of POX. The contrasting effects of the conservative amino acid exchange V265A on the enzyme's catalytic properties, cofactor affinity, and protein structure were investigated. The most prominent effect of the exchange was observed in the 2.2 A crystal structure of the mutant POX. While the overall structures of the wild-type and the variant are similar, flavin binding in particular is clearly different. Local disorder at the isoalloxazine binding site prevents modeling of the complete FAD cofactor and two protein loops of the binding site. Only the ADP moiety shows well-defined electron density, indicating an "anchor" function for this part of the molecule. This notion is corroborated by competition experiments where ADP was used to displace FAD from the variant enzyme. Despite the fact that the affinity of FAD binding in the variant is reduced, the catalytic properties are very similar to the wild-type, and the redox potential of the bound flavin is the same for both proteins. The rate of electron transfer toward the flavin during turnover is reduced to one-third compared to the wild-type, but k(cat) remains unchanged. Redox-triggered FTIR difference spectroscopy of free FAD shows the nu(C(10a)=N(1)) band at 1548 cm(-)(1). In POX-V265A, this band is found at 1538 cm(-)(1) and thus shifted less strongly than in wild-type POX where it is found at 1534 cm(-)(1). Taking these observations together, the conservative exchange V265A in POX has a surprisingly small effect on the catalytic properties of the enzyme, whereas the effect on the three-dimensional structure is rather big.

  12. Effect of Casein Phosphopeptide-Amorphous Calcium Phosphate and Three Calcium Phosphate on Enamel Microhardness.

    Science.gov (United States)

    Haghgou, En Hr; Haghgoo, Roza; Roholahi, Mohamad R; Ghorbani, Zahra

    2017-07-01

    This study aims to investigate the effect of casein phos-phopeptide-amorphous calcium phosphate and three calcium phosphate (CPP-ACP and TCP) on increasing the microhardness of human enamel after induction of erosion. A total of 26 healthy human-impacted third molar teeth were chosen, and their hardness measured using a microhardness testing machine. The samples were immersed in Coca Cola (pH = 4.7) for 8 minutes. Then, micro-hardness was measured again, and these samples were randomly divided into four groups (two control groups and two experimental groups). (1) Negative control group: Artificial saliva was used for 10 minutes, (2) positive control group: Fluoride gel was used for 10 minutes, (3) β-TCP group: TCP was used for 10 minutes, (4) CCP-ACP group: CCP-ACP was used for 10 minutes. The final microhardness of those samples was measured, and the changes in microhardness of teeth within group and between groups were analyzed using the paired and analysis of variance tests respectively. Results were considered statistically significant at a level of p < 0.05. No significant difference was observed in microhard-ness between CPP-ACP group and TCP group (p = 0.368) during the time microhardness significantly dropped after soaking in soda. Casein phosphopeptide-amorphous calcium phosphate and TCP increased the microhardness of teeth. The increase in hardness in the TCP group was higher than in the CPP-ACP group, but this difference was not significant (p = 0.36). Casein phosphopeptide-amorphous calcium phosphate and TCP can affect the remineralization of erosive lesions.

  13. Cultural participation in Europe

    DEFF Research Database (Denmark)

    Stevenson, David; Kann-Rasmussen, Nanna; Balling, Gitte

    2015-01-01

    Europe has a ‘problem’; it is becoming a ‘less cultural continent’ as fewer Europeans are ‘engaging in cultural activities’. This conclusion has been reached due to the findings of the latest cross national cultural participation survey. This paper questions the existence of this ‘problem...

  14. List of participants

    Indian Academy of Sciences (India)

    List of participants. Abbas Sohrab, BARC, Mumbai, India. Achary S N, BARC, Mumbai, India. Acharya Prashant G, JMS College, Ahmedabad, India. Aggarwal S K, BARC, Mumbai, India. Agrawal Ashish, BARC, Mumbai, India. Alam Md Sayem, AMU, Aligarh, India. Alamelu D, BARC, Mumbai, India. Aldona Rajewska, IAE ...

  15. Total design of participation

    DEFF Research Database (Denmark)

    Munch, Anders V.

    2016-01-01

    The idea of design as an art made not only for the people, but also by the people is an old dream going back at least to William Morris. It is, however, reappearing vigoriously in many kinds of design activism and grows out of the visions of a Total Design of society. The ideas of participation b...

  16. European Patterns of Participation

    DEFF Research Database (Denmark)

    Harrebye, Silas Fehmerling; Ejrnæs, Anders

    2015-01-01

    Social Survey (ESS) Round 4 (2008), the article finds that satisfaction/dissatisfaction with the government is an important predictor alongside the institutional macro-level variable. The article combines a critical tradition, which suggests that political participation is motivated by a feeling...

  17. The body participating:

    DEFF Research Database (Denmark)

    Pallesen, Hanne; Lund, Lone Blak; Jensen, Marianne

    2017-01-01

    -based analyses. The results were theoretically stated and supported. Results: In an effort to achieve patient participation, the following four themes seemed to be significant: 1) consciously encountering the patient in the moment, 2) the employment of concepts surrounding the interaction between body...

  18. Communication Games: Participant's Manual.

    Science.gov (United States)

    Krupar, Karen R.

    Using a series of communicational games, the author leads the participant through self-awareness, verbal and nonverbal communication, decision-making, problem-solving, and skills in perception, listening, and small group, organizational, and cultural communications. The thesis behind the book is that model-making, role-playing, or other forms of…

  19. BURNOUT AND OCCUPATIONAL PARTICIPATION

    Science.gov (United States)

    Eren, Hakan; Huri, Meral; Bağış, Nilsun; Başıbüyük, Onur; Şahin, Sedef; Umaroğlu, Mutlu; Orhan, Kaan

    2016-11-01

    The aim of the present study was to investigate the prevalence of burnout and occupational participation limitation among dental students in a dental school in Turkey. Four hundred fifty-eight dental students (females=153; males=305) were included in the study. The age range varied from 17-to-38 years. Maslach Burnout Inventory-Student Version (MBI-SV) and Canadian Occupational Performance Measure (COPM) were used to gather data. Descriptive analyses, t-test, and Kruskall-Wallis test for independent groups were used for data analyses. The results indicated that 26% of all the students have burnout in terms of emotional exhaustion (25%), cynicism (18%), and academic efficacy (14%). The results showed that burnout is statistically significant in relation to demographics (pstudents showed considerably decreased occupational performance and satisfaction scores, which suggested occupational participation limitations. Occupational performance and satisfaction scores were inversely correlated with emotional exhaustion and cynicism, while directly correlated with reduced academic efficacy (pburnout and occupational participation limitation can be seen among dental students. Students with burnout may also have occupational participation limitation. Enriching dental education programs with different psychological strategies may be useful for education of healthy dentists and improve the quality of oral and dental health services.

  20. Participation, Care and Support

    NARCIS (Netherlands)

    Prof. dr. Jean Pierre Wilken

    2017-01-01

    The research group Participation, Care and Support is part of the Research Centre for Social Innovation of Utrecht University for Applied Sciences. This is a transdisciplinary research centre, doing practice based research focused on relevant social issues, connecting different fields like social

  1. Participation of Youth

    OpenAIRE

    UNCTAD; World Bank

    2018-01-01

    This note provides examples that investors, civil society, and governments can follow to engage youth in participating in agriculture. Young people can be the driving force for the inclusive rural transformation needed to address the many challenges posed by growing populations, urbanization, and youth unemployment. Yet, many young people are frustrated by the lifestylesand opportunities a...

  2. Participation under Uncertainty

    International Nuclear Information System (INIS)

    Boudourides, Moses A.

    2003-01-01

    This essay reviews a number of theoretical perspectives about uncertainty and participation in the present-day knowledge-based society. After discussing the on-going reconfigurations of science, technology and society, we examine how appropriate for policy studies are various theories of social complexity. Post-normal science is such an example of a complexity-motivated approach, which justifies civic participation as a policy response to an increasing uncertainty. But there are different categories and models of uncertainties implying a variety of configurations of policy processes. A particular role in all of them is played by expertise whose democratization is an often-claimed imperative nowadays. Moreover, we discuss how different participatory arrangements are shaped into instruments of policy-making and framing regulatory processes. As participation necessitates and triggers deliberation, we proceed to examine the role and the barriers of deliberativeness. Finally, we conclude by referring to some critical views about the ultimate assumptions of recent European policy frameworks and the conceptions of civic participation and politicization that they invoke

  3. Student Participation in Governance

    Science.gov (United States)

    Deegan, William L.; And Others

    1970-01-01

    The success of student government activities on any campus is significantly affected by the amount of student participation permitted in the institution's decision-making processes. The traditional" model of government--characterized by tokenism--often results in the separate jurisdictions" model-- characterized by fragmentation and interest…

  4. Participation in decision making

    Directory of Open Access Journals (Sweden)

    EG Valoyi

    2000-06-01

    Full Text Available The aim of the present study was to determine the extent to which employees would like to participate in decision making concerning various organisational issues, especially those concerning: the work itself, working conditions, human resources issues, and corporate policy and planning. The sample consisted of 146 participants, including managers, middle managers, and junior officials from a South African development corporation. A questionnaire to measure employees' desire to participate in decision making was specially constructed for this investigation. It has found that employees with higher academic qualifications were more desirous to participate in decision-making at all levels than employees with lower academic qualifications. This was also true for employees in higher job grades than in lower job grades. Men were more desirous to participate in decision making than women. The implications of the findings are discussed. Opsomming Die doel van die huidige studie was om vas te stel in watter mate werknemers sal wil deelneem aan die besluit- nameproses van organisasies, veral rakende die volgende sake: die werk self, werksomstandighede, menslike hulpbronaangeleenthede en korporatiewe beleid en beplanning. Die steekproef het uit 146 deelnemers, insluitende bestuurders, middelvlakbestuurders en junior amptenare van'n Suid Afrikaanse ontwikkelingskorporasie, bestaan. nVraelys wat die begeerte van werknemers meet om aan die besluitnameproses deel te neem, is spesiaal vir die doel van hierdie ondersoek, ontwerp. Dit is bevind dat werknemers met hoer akademiese kwalifikasies meer begerig is om aan die besluitnameproses op alle vlakke deel te neem as werknemers met laer akademiese kwalifikasies. Dit was ook waar vir werknemers in hoervlakposte vergeleke met werknemers in laervlakposte. Mans was ook meer begerig om aan die besluitnameproses deel te neem as vroue. Die implikasies van die studie word bespreek.

  5. Phosphate ions as inhibiting agents for copper corrosion in chlorinated tap water

    Energy Technology Data Exchange (ETDEWEB)

    Yohai, L. [División Electroquímica y Corrosión, INTEMA, CONICET, UNMdP, Juan B. Justo 4302, B7608FDQ Mar del Plata (Argentina); Schreiner, W.H. [Laboratório de Superfícies e Interfases, Departamento de Física, Universidade Federal do Paraná, 81531-990 Curitiba, PR (Brazil); Vázquez, M., E-mail: mvazquez@fi.mdp.edu.ar [División Electroquímica y Corrosión, INTEMA, CONICET, UNMdP, Juan B. Justo 4302, B7608FDQ Mar del Plata (Argentina); Valcarce, M.B. [División Electroquímica y Corrosión, INTEMA, CONICET, UNMdP, Juan B. Justo 4302, B7608FDQ Mar del Plata (Argentina)

    2013-05-15

    PO{sub 4}{sup 3−} ions as corrosion inhibitor were investigated on copper in tap water in the presence of NaClO. The inhibitor was evaluated by electrochemical techniques and weight loss tests. Raman spectroscopy and X-ray photoelectron spectroscopy were used to study the passive layer. In inhibited tap water, the passive layer is thick and compact if NaClO is present. Weight-loss tests showed the inhibition of uniform dissolution and no pitting attack. When adding NaClO, Cu{sub 3}(PO{sub 4}){sub 2} is incorporated to the passive film. Thus, phosphate ions are effective as inhibitors for copper in tap water, even when using high dosages of biocides. - Highlights: ► Changes in the copper corrosion after adding phosphate to tap water were analyzed. ► When NaClO and phosphates are present, Cu{sub 3}(PO{sub 4}){sub 2} participates of the surface film. ► In the absence of biocide the surface film contains a mixture of Cu{sub 2}O, CuO and Cu(OH){sub 2}. ► PO{sub 4}{sup 3−} is an effective inhibitor for Cu in tap water containing high NaClO dosages.

  6. Phosphate ions as inhibiting agents for copper corrosion in chlorinated tap water

    International Nuclear Information System (INIS)

    Yohai, L.; Schreiner, W.H.; Vázquez, M.; Valcarce, M.B.

    2013-01-01

    PO 4 3− ions as corrosion inhibitor were investigated on copper in tap water in the presence of NaClO. The inhibitor was evaluated by electrochemical techniques and weight loss tests. Raman spectroscopy and X-ray photoelectron spectroscopy were used to study the passive layer. In inhibited tap water, the passive layer is thick and compact if NaClO is present. Weight-loss tests showed the inhibition of uniform dissolution and no pitting attack. When adding NaClO, Cu 3 (PO 4 ) 2 is incorporated to the passive film. Thus, phosphate ions are effective as inhibitors for copper in tap water, even when using high dosages of biocides. - Highlights: ► Changes in the copper corrosion after adding phosphate to tap water were analyzed. ► When NaClO and phosphates are present, Cu 3 (PO 4 ) 2 participates of the surface film. ► In the absence of biocide the surface film contains a mixture of Cu 2 O, CuO and Cu(OH) 2 . ► PO 4 3− is an effective inhibitor for Cu in tap water containing high NaClO dosages

  7. Towards Phosphate Detection in Hydroponics Using Molecularly Imprinted Polymer Sensors.

    Science.gov (United States)

    Storer, Christopher S; Coldrick, Zachary; Tate, Daniel J; Donoghue, Jack Marsden; Grieve, Bruce

    2018-02-10

    An interdigitated electrode sensor was designed and microfabricated for measuring the changes in the capacitance of three phosphate selective molecularly imprinted polymer (MIP) formulations, in order to provide hydroponics users with a portable nutrient sensing tool. The MIPs investigated were synthesised using different combinations of the functional monomers methacrylic acid (MAA) and N -allylthiourea, against the template molecules diphenyl phosphate, triethyl phosphate, and trimethyl phosphate. A cross-interference study between phosphate, nitrate, and sulfate was carried out for the MIP materials using an inductance, capacitance, and resistance (LCR) meter. Capacitance measurements were taken by applying an alternating current (AC) with a potential difference of 1 V root mean square (RMS) at a frequency of 1 kHz. The cross-interference study demonstrated a strong binding preference to phosphate over the other nutrient salts tested for each formulation. The size of template molecule and length of the functional monomer side groups also determined that a short chain functional monomer in combination with a template containing large R-groups produced the optimal binding site conditions when synthesising a phosphate selective MIP.

  8. Phosphate limitation induces sporulation in the chytridiomycete Blastocladiella emersonii.

    Science.gov (United States)

    Bongiorno, Vagner Alexandre; Ferreira da Cruz, Angela; Nunis da Silva, Antonio; Corrêa, Luiz Carlos

    2012-09-01

    The cell cycle is controlled by numerous mechanisms that ensure correct cell division. If growth is not possible, cells may eventually promote autophagy, differentiation, or apoptosis. Microorganisms interrupt their growth and differentiate under general nutrient limitation. We analyzed the effects of phosphate limitation on growth and sporulation in the chytridiomycete Blastocladiella emersonii using kinetic data, phase-contrast, and laser confocal microscopy. Under phosphate limitation, zoospores germinated and subsequently formed 2-4 spores, regardless of the nutritional content of the medium. The removal of phosphate at any time during growth induced sporulation of vegetative cells. If phosphate was later added to the same cultures, growth was restored if the cells were not yet committed to sporulation. The cycles of addition and withdrawal of phosphate from growth medium resulted in cycles of germination-growth, germination-sporulation, or germination-growth-sporulation. These results show that phosphate limitation is sufficient to interrupt cell growth and to induce complete sporulation in B. emersonii. We concluded that the determination of growth or sporulation in this microorganism is linked to phosphate availability when other nutrients are not limiting. This result provides a new tool for the dissection of nutrient-energy and signal pathways in cell growth and differentiation.

  9. Engineering Potato Starch with a Higher Phosphate Content.

    Directory of Open Access Journals (Sweden)

    Xuan Xu

    Full Text Available Phosphate esters are responsible for valuable and unique functionalities of starch for industrial applications. Also in the cell phosphate esters play a role in starch metabolism, which so far has not been well characterized in storage starch. Laforin, a human enzyme composed of a carbohydrate-binding module and a dual-specificity phosphatase domain, is involved in the dephosphorylation of glycogen. To modify phosphate content and better understand starch (dephosphorylation in storage starch, laforin was engineered and introduced into potato (cultivar Kardal. Interestingly, expression of an (engineered laforin in potato resulted in significantly higher phosphate content of starch, and this result was confirmed in amylose-free potato genetic background (amf. Modified starches exhibited altered granule morphology and size compared to the control. About 20-30% of the transgenic lines of each series showed red-staining granules upon incubation with iodine, and contained higher phosphate content than the blue-stained starch granules. Moreover, low amylose content and altered gelatinization properties were observed in these red-stained starches. Principle component and correlation analysis disclosed a complex correlation between starch composition and starch physico-chemical properties. Ultimately, the expression level of endogenous genes involved in starch metabolism was analysed, revealing a compensatory response to the decrease of phosphate content in potato starch. This study provides a new perspective for engineering starch phosphate content in planta by making use of the compensatory mechanism in the plant itself.

  10. Availability of native and added phosphates for the soil

    International Nuclear Information System (INIS)

    Scivittaro, W.B.; Boaretto, A.E.; Muraoka, T.

    1995-01-01

    In superficial composite samples of two Red-Yellow Latosols with different physical and chemical properties, analyses were carried out on inorganic form of phosphorus as well as the availability of native and added phosphates. The method applied was soil phosphorus fractionation associated with isotopic dilution technique ( 32 P). The samples were taken from pots containing soils incubated for a month with fluid phosphatic fertilizers (phosphoric acid and 10-30-00 suspension) and solid phosphatic fertilizers (mono ammonium phosphate and triple superphosphate), at the rate of 210 mg P 2 O 5 /kg of soil. A control treatment was included. In both soils the availability of inorganic phosphorus fractions decreased at the following order: H 2 O-P > Al-P > Fe-P > CA-P > occluded-P. The water soluble and aluminium phosphates represented the main source of available P for the newly fertilizer, the iron phosphates were also an important source of available phosphorus. The soil phosphorus fixing capacity influenced the availability of native and added phosphates. (author). 17 refs, 3 tabs

  11. Immobilization of radioactive strontium in contaminated soils by phosphate treatment

    International Nuclear Information System (INIS)

    Kim, K.H.; Ammons, J.T.

    1990-01-01

    The feasibility of in situ phosphate- and metal- (calcium, aluminum, and iron) solution treatment for 90 Sr immobilization was investigated. Batch and column experiments were performed to find optimum conditions for coprecipitation of 90 Sr with Ca-, Al-, and Fe-phosphate compounds in contaminated soils. Separate columns were packed with artificially 85 Sr-contaminated acid soil as well as 90 Sr-contaminated soil from the Oak Ridge Reservation. After metal-phosphate treatment, the columns were then leached successively with either tapwater or 0.001 M CaCl 2 solution. Most of the 85 Sr coprecipitated with the metal phosphate compounds. Immobilization of 85 Sr and 90 Sr was affected by such factors as solution pH, metal and phosphate concentration, metal-to-phosphate ratio, and soil characteristics. Equilibration time after treatments also affected 85 Sr immobilization. Many technology aspects still need to be investigated before field applications are feasible, but these experiments indicate that phosphate-based in situ immobilization should prevent groundwater contamination and will be useful as a treatment technology for 90 Sr-contaminated sites. 15 refs., 3 figs., 1 tab

  12. Participating in patient education

    DEFF Research Database (Denmark)

    Kristiansen, Tine Mechlenborg; Antoft, Rasmus

    2015-01-01

    point is applied in order to illustrate two central status passages taking place at the locally developed patient education programme: 1) The status passage from novice to an experienced person with chronic illness, and 2) The transformation from adolescence to adulthood living with a chronic illness......The paper builds on previous ethnographic research in Denmark focusing on the significance of participating in a locally developed patient education programme for everyday life (Kristiansen et.al. 2015). It presents a secondary analysis. Group based patient education can be understood as a health...... studies within the field of patient education and how it can enhance our understanding of the social practices at play and the identity transitions occurring as a result of the chronic illness itself and the participation at the programme. Further we reflect on potential practical implications of our...

  13. Walking - Sensing - Participation

    DEFF Research Database (Denmark)

    Bødker, Mads; Meinhardt, Nina Dam; Browning, David

    2014-01-01

    Building on ethnographic research and social theory in the field of ‘mobilities’, this workshop paper suggests that field work based on simply walking with people entails a form of embodied participation that informs technological interventions by creating a space within which to address a wider ...... set of experiential or ‘felt’ qualities of living with mobile technologies. Moving from reflections on the value of walking with people, the paper outlines some affordances of a smartphone application built to capture place experiences through walking.......Building on ethnographic research and social theory in the field of ‘mobilities’, this workshop paper suggests that field work based on simply walking with people entails a form of embodied participation that informs technological interventions by creating a space within which to address a wider...

  14. Planning and participation

    International Nuclear Information System (INIS)

    Rucht, D.

    1982-01-01

    This study is trying to give a vast survey of the political and administrative system. It is to demonstrate the relations between its secular development trends, the necessity and the limits of political planning under the present conditions and, finally, the increasing demands for participation as expressed especially by citizens' initiatives. These stages, however, are certainly not presented in a smooth manner. Yet the author claims to have kept a certain continuity and inner logic of presentation and argumentation. (orig./DG) [de

  15. Effect of lysine to alanine mutations on the phosphate activation and BPTES inhibition of glutaminase.

    Science.gov (United States)

    McDonald, Charles J; Acheff, Eric; Kennedy, Ryan; Taylor, Lynn; Curthoys, Norman P

    2015-09-01

    The GLS1 gene encodes a mitochondrial glutaminase that is highly expressed in brain, kidney, small intestine and many transformed cells. Recent studies have identified multiple lysine residues in glutaminase that are sites of N-acetylation. Interestingly, these sites are located within either a loop segment that regulates access of glutamine to the active site or the dimer:dimer interface that participates in the phosphate-dependent oligomerization and activation of the enzyme. These two segments also contain the binding sites for bis-2[5-phenylacetamido-1,2,4-thiadiazol-2-yl]ethylsulfide (BPTES), a highly specific and potent uncompetitive inhibitor of this glutaminase. BPTES is also the lead compound for development of novel cancer chemotherapeutic agents. To provide a preliminary assessment of the potential effects of N-acetylation, the corresponding lysine to alanine mutations were constructed in the hGACΔ1 plasmid. The wild type and mutated proteins were purified by Ni(+)-affinity chromatography and their phosphate activation and BPTES inhibition profiles were analyzed. Two of the alanine substitutions in the loop segment (K311A and K328A) and the one in the dimer:dimer interface (K396A) form enzymes that require greater concentrations of phosphate to produce half-maximal activation and exhibit greater sensitivity to BPTES inhibition. By contrast, the K320A mutation results in a glutaminase that exhibits near maximal activity in the absence of phosphate and is not inhibited by BPTES. Thus, lysine N-acetylation may contribute to the acute regulation of glutaminase activity in various tissues and alter the efficacy of BPTES-type inhibitors. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Sanitation and Civic Participation

    Directory of Open Access Journals (Sweden)

    José Antonio Peña Barreto

    2016-08-01

    Full Text Available This research is proposed in order to propose an action plan for environmental sanitation citizen participation in the "Manuela Sáenz" Concentrating National Basic School Parish Municipality City Bolivia Pedraza Barinas state. It is part of the qualitative approach in the form of participatory action research and supported by a narrative descriptive design. The selected scenario for performance of work was the Concentrating National School "Manuela Sáenz" key informants consist of 1 member of the community, 1 member of the community council and one teacher of the institution. The techniques used are observation and depth interview, using as instruments a field notebook and an interview script. For the presentation and analysis of results he was categorized, triangulated and theorized the information obtained, performing a thorough and detailed report on the integrated management of solid waste diagnosis. Subsequently, the proposal called Action Plan for environmental sanitation was developed with citizen participation in concentrated Manuela Saenz National Basic School. Then the proposal where participants expressed the view that activities allowed to obtain very important basic knowledge on environmental sanitation was run.

  17. Biodegradation of tributyl phosphate by granular biofilms

    International Nuclear Information System (INIS)

    Joshi, Hiren M.; Nancharaiah, Y.V.; Venugopalan, V.P.

    2009-01-01

    Full text: Tributyl phosphate (TBP) is used as plasticizer for cellulose esters, lacquers, plastic and vinyl resins and as a solvent extractant of rare earth metals. In nuclear power industry, it is used as a solvent for the extraction of uranium and plutonium salts during fuel reprocessing. TBP does not occur naturally in the environment. It is sparingly soluble in water and once released into soil or aquatic systems, is only moderately biodegradable. There are many proposed mechanisms for TBP biodegradation, which involve stepwise enzymatic hydrolysis to orthophosphate and n-butanol and mono-oxygenase based transformation and then degradation. Microbial processes involving multispecies consortia offer better choice over monoculture processes for degradation of complex wastes. Processes based on immobilized microbial consortia are characterized by significantly reduced settling time, high stability in presence of varying organic load, effective mineralization and amenability to bioaugmentation, which make them a good choice for bioremediation and waste water treatment. The objective of this study was to investigate the suitability of aerobic microbial granules (also known as granular biofilms) for efficient biodegradation of TBP. For this purpose, we set up 4 litre cylindrical sequencing batch reactors (SBR) in triplicates and inoculated them with sludge (mean sludge size ∼ 60 mm) obtained from an operating wastewater treatment plant. The SBRs were operated on a 6h cycle with 66% volumetric exchange ratio. The reactors were fed with synthetic waste water along with 90 mM acetate and 0.5 mM TBP. The concentration of TBP was slowly raised to 2mM. After 3 months of operation, microbial granules (mean size: 2.05 mm) capable of TBP degradation were observed in the reactors. Gas chromatographic analysis of samples showed that after 6h of operational cycle 2 mM initial concentration of TBP was reduced to 0.2 mM, after which there was no further degradation. Cessation

  18. Metal cation controls phosphate release in the myosin ATPase.

    Science.gov (United States)

    Ge, Jinghua; Huang, Furong; Nesmelov, Yuri E

    2017-11-01

    Myosin is an enzyme that utilizes ATP to produce a conformational change generating a force. The kinetics of the myosin reverse recovery stroke depends on the metal cation complexed with ATP. The reverse recovery stroke is slow for MgATP and fast for MnATP. The metal ion coordinates the γ phosphate of ATP in the myosin active site. It is accepted that the reverse recovery stroke is correlated with the phosphate release; therefore, magnesium "holds" phosphate tighter than manganese. Magnesium and manganese are similar ions in terms of their chemical properties and the shell complexation; hence, we propose to use these ions to study the mechanism of the phosphate release. Analysis of octahedral complexes of magnesium and manganese show that the partial charge of magnesium is higher than that of manganese and the slightly larger size of manganese ion makes its ionic potential smaller. We hypothesize that electrostatics play a role in keeping and releasing the abstracted γ phosphate in the active site, and the stronger electric charge of magnesium ion holds γ phosphate tighter. We used stable myosin-nucleotide analog complex and Raman spectroscopy to examine the effect of the metal cation on the relative position of γ phosphate analog in the active site. We found that in the manganese complex, the γ phosphate analog is 0.01 nm further away from ADP than in the magnesium complex. We conclude that the ionic potential of the metal cation plays a role in the retention of the abstracted phosphate. © 2017 The Protein Society.

  19. Industrial hygiene survey. IMC, Phosphate Chemical Complex, New Wales, Florida

    International Nuclear Information System (INIS)

    Stephenson, F.; Cassady, M.

    1977-10-01

    An industrial hygiene survey was conducted by NIOSH at IMC Phosphate Chemical Complex, New Wales, Florida, on June 7-11, 1976, as part of a study of the phosphate industry. Phosphate fertilizer manufacturing, the plant, and the medical, safety, and industrial hygiene programs are described. During the study 8-hour time weighted averages were determined for exposure to arsenic, cadmium, chromium, vanadium, phosphoric acid, and sulfuric acid for workers involved in cleaning out phosphoric acid reactor vessels. General area samples were collected for fluorides, radon, and uranium. Several samples were above the NIOSH recommended levels for arsenic and chromium

  20. Iron phosphate materials as cathodes for lithium batteries

    CERN Document Server

    Prosini, Pier Paolo

    2011-01-01

    ""Iron Phosphate Materials as Cathodes for Lithium Batteries"" describes the synthesis and the chemical-physical characteristics of iron phosphates, and presents methods of making LiFePO4 a suitable cathode material for lithium-ion batteries. The author studies carbon's ability to increase conductivity and to decrease material grain size, as well as investigating the electrochemical behaviour of the materials obtained. ""Iron Phosphate Materials as Cathodes for Lithium Batteries"" also proposes a model to explain lithium insertion/extraction in LiFePO4 and to predict voltage profiles at variou

  1. Serum phosphate predicts early mortality in adults starting antiretroviral therapy in Lusaka, Zambia: a prospective cohort study.

    Directory of Open Access Journals (Sweden)

    Douglas C Heimburger

    Full Text Available BACKGROUND: Patients starting antiretroviral therapy (ART for acquired immunodeficiency syndrome (AIDS in sub-Saharan Africa have high rates of mortality in the initial weeks of treatment. We assessed the association of serum phosphate with early mortality among HIV-infected adults with severe malnutrition and/or advanced immunosuppression. METHODOLOGY/PRINCIPAL FINDINGS: An observational cohort of 142 HIV-infected adults initiating ART in Lusaka, Zambia with body mass index (BMI <16 kg/m(2 or CD4(+ lymphocyte count <50 cells/microL, or both, was followed prospectively during the first 12 weeks of ART. Detailed health and dietary intake history, review of systems, physical examination, serum metabolic panel including phosphate, and serum ferritin and high-sensitivity C-reactive protein (hsCRP were monitored. The primary outcome was mortality. Baseline serum phosphate was a significant predictor of mortality; participants alive at 12 weeks had a median value of 1.30 mmol/L (interquartile range [IQR]: 1.04, 1.43, compared to 1.06 mmol/L (IQR: 0.89, 1.27 among those who died (p<0.01. Each 0.1 mmol/L increase in baseline phosphate was associated with an incremental decrease in mortality (AHR 0.83; 95% CI 0.72 to 0.95. The association was independent of other metabolic parameters and known risk factors for early ART-associated mortality in sub-Saharan Africa. While participant attrition represented a limitation, it was consistent with local program experience. CONCLUSIONS/SIGNIFICANCE: Low serum phosphate at ART initiation was an independent predictor of early mortality among HIV patients starting ART with severe malnutrition or advanced immunosuppression. This may represent a physiologic phenomenon similar to refeeding syndrome, and may lead to therapeutic interventions that could reduce mortality.

  2. Flotation separation of strontium via phosphate precipitation.

    Science.gov (United States)

    Thanh, Luong H V; Liu, J C

    2017-06-01

    Flotation separation of strontium (Sr) from wastewater via phosphate precipitation was investigated. While 37.33% of Sr precipitated at highly alkaline pH in the absence of PO 4 3- , it completely precipitated as Sr 3 (PO 4 ) 2 at a molar ratio ([PO 4 3- ]:[Sr 2+ ]) of 0.62 at a lower pH value. The presence of Ca 2+ hindered Sr precipitation, yet it could be overcome by increasing the PO 4 3- dose. Sodium dodecyl sulfate (SDS) was a better collector for dispersed air flotation of Sr 3 (PO 4 ) 2 than cetyl trimethyl ammonium bromide, or mixed collector systems of SDS and saponin. The highest separation efficiency of 97.5% was achieved at an SDS dose of 40 mg/L. The main mechanism in the precipitate flotation is adsorption of anionic SDS on the positively charged surface of colloidal Sr 3 (PO 4 ) 2 via electrostatic interaction. SDS enhanced the aggregation of Sr 3 (PO 4 ) 2 precipitates as the size increased from 1.65 to 28.0 μm, which was beneficial to separation as well.

  3. Phosphate Barriers for Immobilization of Uranium Plumes

    International Nuclear Information System (INIS)

    Burns, Peter C.

    2004-01-01

    Uranium contamination of the subsurface remains a persistent problem plaguing remedial design at sites across the U.S. that were involved with production, handling, storage, milling, and reprocessing of uranium for both civilian and defense related purposes. Remediation efforts to date have relied upon excavation, pump-and-treat, or passive remediation barriers (PRB?s) to remove or attenuate uranium mobility. Documented cases convincingly demonstrate that excavation and pump-and-treat methods are ineffective for a number of highly contaminated sites. There is growing concern that use of conventional PRB?s, such as zero-valent iron, may be a temporary solution to a problem that will persist for thousands of years. Alternatives to the standard treatment methods are therefore warranted. The core objective of our research is to demonstrate that a phosphorus amendment strategy will result in a reduction of dissolved uranium to below the proposed drinking water standard. Our hypothesis is that long-chain sodium polyphosphate compounds forestall precipitation of sparingly soluble uranyl phosphate compounds, which is paramount to preventing fouling of wells at the point of injection

  4. Phosphate Barriers for Immobilization of Uranium Plumes

    International Nuclear Information System (INIS)

    Icenhower, Jonathan P.; Burns, Peter C.

    2005-01-01

    Uranium contamination of the subsurface remains a persistent problem plaguing remedial design at sites across the U.S. that were involved with production, handling, storage, milling, and reprocessing of uranium for both civilian and defense related purposes. Remediation efforts to date have relied upon excavation, pump-and-treat, or passive remediation barriers (PRB?s) to remove or attenuate uranium mobility. Documented cases convincingly demonstrate that excavation and pump-and-treat methods are ineffective for a number of highly contaminated sites. There is growing concern that use of conventional PRB's, such as zero-valent iron, may be a temporary solution to a problem that will persist for thousands of years. Alternatives to the standard treatment methods are therefore warranted. The core objective of our research is to demonstrate that a phosphorous amendment strategy will result in a reduction of dissolved uranium to below the proposed drinking water standard. Our hypothesis is that long-chain sodium polyphosphate compounds forestall precipitation of sparingly soluble uranyl phosphate compounds, which is paramount to preventing fouling of wells at the point of injection

  5. Glucose-6-phosphate dehydrogenase deficiency in Singapore.

    Science.gov (United States)

    Quak, S H; Saha, N; Tay, J S

    1996-01-01

    Glucose-6-phosphate dehydrogenase (G6PD) in man is an X-linked enzyme. The deficiency of this enzyme is one of the most common inherited metabolic disorders in man. In Singapore, three clinical syndromes associated with G6PD deficiency had been described: severe haemolysis in neonates with kernicterus, haemoglobinuria and "viral hepatitis"-like syndrome. The human G6PD monomer consists of 515 amino acids. Only the tetrameric or dimeric forms composed of a single type subunit are catylitically active. The complete amino acid sequence of G6PD had been elucidated in man and various other animals. The region of high homology among the enzymes of various animals is presumably functionally active. Among the Chinese in Singapore, three common molecular variants had been identified: Canton (nt 1376 G --> T), Kaiping (nt 1388 G --> A) and Mediterranean (nt 563 C --> T) in frequencies of 24%, 21% and 10% respectively. In addition, two common mutants (Gaozhou, nt 95 A --> G and Chinese 5, nt 1024 C --> T) have been detected in Singapore Chinese in low frequencies. In Malays, 6 different deficient variants are known in Singapore (3 new, 1 Mahidol, 1 Indonesian and 1 Mediterranean).

  6. Separation of tributyl phosphate from degraded solvents

    International Nuclear Information System (INIS)

    Kumar, S.V.; Nadkarni, M.N.; Ramanujam, A.; Venkatesan, M.; Gopalakrishnan, V.; Kazi, J.A.

    1977-01-01

    A solvent extraction method is described for the recovery of tributyl phosphate (TBP) from degraded process solvents. The method involves the separation of TBP and shell solT(SST) from 30% TBP/SSP mixture by thorium nitrate extraction leading to the formation of a heavy phase (third phase) which contains essentially TBP. The equilibrium experiments revealed that by utilizing thorium feeds of concentrations above 525 g/L in water at 1:1 ratio, a 30% TBP/SST mixture can be effectively separated into TBP and SST fractions with light SST phase having about 3% TBP. Using single stage mixer settler experiments, the feasibility of continuous separation of the three phases was assessed. Since there is a tendency for the degraded products of the diluent to seek the TBP phase, additional treatment steps would be necessary for their removal if the TBP is to be reused. Activated charcoal was investigated for this purpose. If purification of the TBP is not envisaged the volume of the organic waste generated in processing plants could be reduced by separating the diluent and TBP and only the TBP could be sent as concentrated waste. (author)

  7. Glucose 6 phosphate dehydrogenase deficiency in adults

    International Nuclear Information System (INIS)

    Khan, M.

    2004-01-01

    Objective: To determine the frequency of glucose-6-phosphate dehydrogenase (G6PD) deficiency in adults presented with anemia. Subjects and Methods: Eighteen months admission data was reviewed for G6PD deficiency as a cause of anemia. Anemia was defined by world health organization (WHO) criteria as haemoglobin less than 11.3 gm%. G6PD activity was measured by Sigma dye decolorisation method. All patients were screened for complications of hemolysis and its possible cause. Patients with more than 13 years of age were included in the study. Results: Out of 3600 patients admitted, 1440 were found anaemic and 49 as G6PD deficient. So the frequency of G6PD deficiency in anaemic patients was 3.4% and the overall frequency is 1.36%. G6PD deficiency among males and females was three and six percent respectively. Antimalarials and antibiotics containing sulphonamide group were the most common precipitating factors for hemolysis. Anemia and jaundice were the most common presentations while malaria was the most common associated disease. Acute renal failure was the most severe complication occurring in five patients with two deaths. Conclusion: G6PD deficiency is a fairly common cause of anemia with medicine as common precipitating factor for hemolysis. Such complications can be avoided with early recognition of the disease and avoiding indiscriminate use of medicine. (author)

  8. Glucose 6-phosphate dehydrogenase variants in Japan.

    Science.gov (United States)

    Miwa, S

    1980-01-01

    Fifty-four cases of glucose 6-phosphate dehydrogenase (G6PD) deficiency have so far been reported in Japan. Among them, 21 G6PD variants have been characterized. Nineteen out of the 21 variants were characterized in our laboratory and G6PD Heian and "Kyoto" by others. G6PD Tokyo, Tokushima, Ogikubo, Kurume, Fukushima, Yokohama, Yamaguchi, Wakayama, Akita, Heian and "Kyoto" were classified as Class 1, because all these cases showed chronic hemolytic anemia and severe enzyme deficiency. All these variants showed thermal instability. G6PD Mediterranean-like, Ogori, Gifu and Fukuoka were classified as Class 2, whereas G6PD Hofu, B(-) Chinese, Ube, Konan, Kamiube and Kiwa belonged to Class 3. All the 6 Class 3 variants were found as the results of the screening tests. The incidence of the deficiency in Japanese seems to be 0.1-0.5% but that of the cases which may slow drug-induced hemolysis would be much less. G6PD Ube and Konan appear to be relatively common in Japan.

  9. Cesium immobilization into potassium magnesium phosphate matrix

    International Nuclear Information System (INIS)

    Sayenko, S.Y.; Shkuropatenko, V.A.; Bereznyak, O.P.; Hodyreva, Y.S.; Tarasov, R.V.; Virych, V.D.; Ulybkina, E.A.; Pylypenko, O.V.; Kholomeev, G.O.; Zykova, A.V.; Wagh, Arun S.

    2017-01-01

    The possibility of isomorphous substitution of potassium ions by cesium ions in the structure of potassium magnesium phosphate KMgPO 4 centred dot 6H 2 O (PMP) was shown. It was established, that the Cs included into the PMP matrix does not transfer to the environment during high temperatures heating process (1176 deg C, 3 hours). Analysis of the IR absorption spectrum of the PMP sample has demonstrated that an increase in the amount of additive of the cesium chloride resulted in the shift of the main bands in the spectrum to the low-frequency region with average shift value 10 cm -1 , which indicates the strengthening of bonds in the crystal lattice of matter. The calculated degree of substitution of potassium by cesium during energy release process in the PMP matrix at the level of vitrified high level wastes is about 4%, i. e. the PMP matrix should correspond to the formula K 0.96 Cs 0.04 MgPO 4 centred dot 6H 2 O.

  10. Acceptance, Tolerance, Participation

    International Nuclear Information System (INIS)

    1993-01-01

    The problem of radioactive waste management from an ethical and societal viewpoint was treated in this seminar, which had participants from universities (social, theological, philosophical and science institutes), waste management industry, and regulatory and controlling authorities. After initial reviews on repository technology, policies and schedules, knowledge gaps, and ethical aspects on decision making under uncertainty, four subjects were treated in lectures and discussions: Democratic collective responsibility, Handling threats in democratic decision making, Waste management - a technological operation with a social dimension, Acceptance and legitimity. Lectures with comments and discussions are collected in this report

  11. Invited to Participate?

    DEFF Research Database (Denmark)

    Nielsen, Karen Dam

    paper show the specific challenges patients, and subsequently clinicians, encounter when engaging with an e-health system that is vested with multiple ideas about what patient participation involves. Each of these three papers proposes an analytical concept for opening up the workings of patient......-involving e-health: ‘participatory scopic devices‘, ‘dialogic filtration work‘, and ‘participatory tactics‘. In particular, these concepts add to the analytics of STS and CSCW for studying sociotechnical reconfigurations of healthcare. However, the concepts may also inform the wider field of research into e...

  12. Oral antibodies to human intestinal alkaline phosphatase reduce dietary phytate phosphate bioavailability in the presence of dietary 1α-hydroxycholecalciferol.

    Science.gov (United States)

    Bobeck, Elizabeth A; Hellestad, Erica M; Helvig, Christian F; Petkovich, P Martin; Cook, Mark E

    2016-03-01

    While it is well established that active vitamin D treatment increases dietary phytate phosphate utilization, the mechanism by which intestinal alkaline phosphatase (IAP) participates in phytate phosphate use is less clear. The ability of human IAP (hIAP) oral antibodies to prevent dietary phytate phosphate utilization in the presence of 1α-hydroxycholecalciferol (1α-(OH) D3) in a chick model was investigated. hIAP specific chicken immunoglobulin Y (IgY) antibodies were generated by inoculating laying hens with 17 synthetic peptides derived from the human IAP amino acid sequence and harvesting egg yolk. Western blot analysis showed all antibodies recognized hIAP and 6 of the 8 antibodies selected showed modest inhibition of hIAP activity in vitro (6 to 33% inhibition). In chicks where dietary phosphate was primarily in the form of phytate, 4 selected hIAP antibodies inhibited 1α-(OH) D3-induced increases in blood phosphate, one of which, generated against selected peptide (MFPMGTPD), was as effective as sevelamer hydrochloride in preventing the 1α-(OH) D3-induced increase in blood phosphate, but ineffective in preventing an increase in body weight gain and bone ash induced by 1α-(OH) D3. These studies demonstrated that orally-delivered antibodies to IAP limit dietary phytate-phosphate utilization in chicks treated with 1α-(OH) D3, and implicate IAP as an important host enzyme in increasing phytate phosphate bioavailability in 1α-(OH) D3 fed chicks. © 2015 Poultry Science Association Inc.

  13. Characterization and in vitro evaluation of biphasic α-tricalcium phosphate/β-tricalcium phosphate cement

    Energy Technology Data Exchange (ETDEWEB)

    Arahira, Takaaki; Maruta, Michito, E-mail: maruta@college.fdcnet.ac.jp; Matsuya, Shigeki

    2017-05-01

    Biphasic calcium phosphate consisting of hydroxyapatite (HA) and β-tricalcium phosphate(β-TCP) is an excellent bone substitute with controllable bioresorbability. Fabrication of biphasic calcium phosphate with self-setting ability is expected to enhance its potential application as bone substitute. In this study, mixtures of α-TCP and β-TCP with various compositions were prepared through α-β phase transition of α-TCP powder at 1000 °C for various periods. These powders were mixed with 0.25 M Na{sub 2}HPO{sub 4} at a P/L ratio of 2, and then hardened at 37 °C at 100% RH for up to 24 h. Material properties of biphasic HA/β-TCP cement with different α-TCP/β-TCP composition were characterized. These cements were also evaluated with respect to cell response in vitro using MC3T3-E1 cell lines. In conclusion, mechanical and biological properties of HA/β-TCP cement could be controlled by changing the heat treatment time of α-TCP powder at 1000 °C. In vitro results indicated that cell proliferation and ALP activity increased with increase β-TCP content. - Highlights: • We could fabricate biphasic HA/β-TCP cements using heat treated α-TCP powder. • It is easy to control the ratio of α-TCP to β-TCP changing the heat treatment time up to 48 h. • Both cell number and ALP activity increased with increase in β-TCP content. • In vitro results showed that β-TCP has superior cell affinity to HA.

  14. Iron-phosphate-based chemically bonded phosphate ceramics for mixed waste stabilization

    International Nuclear Information System (INIS)

    Wagh, A.S.; Jeong, S.Y.; Singh, D.

    1997-01-01

    In an effort to develop chemically bonded phosphate ceramics for mixed waste stabilization, a collaborative project to develop iron-phosphate based ceramics has been initiated between Argonne National Laboratory and the V. G. Khlopin Radium Institute in St. Petersburg, Russia. The starter powders are oxides of iron that are generated as inexpensive byproduct materials in the iron and steel industry. They contain iron oxides as a mixture of magnetite (Fe 3 O 4 ) and haematite (Fe 2 O 3 ). In this initial phase of this project, both of these compounds were investigated independently. Each was reacted with phosphoric acid solution to form iron phosphate ceramics. In the case of magnetite, the reaction was rapid. Adding ash as the waste component containing hazardous contaminants resulted in a dense and hard ceramic rich in glassy phase. On the other hand, the reaction of phosphoric acid solution with a mixture of haematite and ash waste contaminated with cesium and americium was too slow. Samples had to be molded under pressure. They were cured for 2-3 weeks and then hardened by heating at 350 degrees C for 3 h. The resulting ceramics in both cases were subjected to physical tests for measurement of density, open porosity, compression strength, phase analyses using X-ray diffraction and differential thermal analysis, and leaching tests using toxicity characteristic leaching procedure (TCLP) and ANS 16.1 with 7 days of leaching. Using the preliminary information obtained from these tests, we evaluated these materials for stabilization of Department of Energy's mixed waste streams

  15. A phosphate-starvation-inducible outermembrane protein of Pseudomonas fluorescens Ag1 as an immunological phosphate-starvation marker

    DEFF Research Database (Denmark)

    Leopold, Kristine; Jacobsen, Susanne; Nybroe, Ole

    1997-01-01

    A phosphate-starvation-inducible outer-membrane protein of Pseudomonas fluorescens Ag1, expressed at phosphate concentrations below0.08-0.13 mM, was purified and characterized. The purification method involved separation of outer-membrane proteins by SDS-PAGE andextraction of the protein from...... nitrocellulose or PVDF membranes after electrotransfer of proteins to the membranes. The N-terminal amino acidsequence of the purified protein, called Psi1, did not show homology to any known proteins, and in contrast to the phosphate-specific porin OprP ofP. aeruginosa its mobility in SDS-PAGE was not affected...

  16. Spaceflight participant visits CERN!

    CERN Multimedia

    Kathryn Coldham

    2016-01-01

    On 15 July, CERN welcomed spaceflight participant Anousheh Ansari.   Anousheh Ansari’s grin stretches from ear to ear, during an intriguing conversation with Nobel laureate Samuel C.C. Ting at AMS POCC. (Image: Maximilien Brice/CERN) Iranian-American Anousheh Ansari was the first-ever female spaceflight participant, spending eight days on the International Space Station (ISS) in 2006. She now has a new addition to her list of extraordinary sights ­– the home of the world’s largest particle accelerator: CERN.   On 15 July, Anousheh Ansari came to CERN and, unsurprisingly, visited the control room of the experiment attached to the ISS: the AMS. At the AMS Payload Operations Control Centre (AMS POCC) on CERN’s Prévessin site, she met the Nobel laureate Samuel Ting, spokesperson of the AMS experiment. Ansari and her accompanying guests were thrilled to expand their knowledge about CERN, its research and its...

  17. PARTICIPANTS IN INSOLVENCY

    Directory of Open Access Journals (Sweden)

    RARES-SEBASTIAN PUIU-NAN

    2012-05-01

    Full Text Available The article examines the officials and other participants in insolvency. The main purpose of the insolvency procedure is to cover all the debts of the debtor side, in favor of his creditor side. The most important regulations regarding this issue consist in Law no. 85/2006, according to it in the insolvency procedure are to be appointed the following officials: insolvency courts of justice, insolvency judge, receiver, liquidator. All these officials have to act in celerity, in order to promptly perform acts and operations provided by law and to respect and provide other participants’ rights and obligations. My article present in the beginning the insolvency courts of justice, their material and territorial competence and the procedure rules. Next chapters are dedicated to the insolvency judge, receiver and liquidator and analyze the following issues: their appointment, their powers, their auxiliary officials and their ceasing of the powers. Some regards on the British law and French law are also included. The next chapter is dedicated to the participants to the insolvency procedure: the creditors general assembly, creditors committee and special administrator, followed by conclusions and recommendations.

  18. Metal Phosphates as Intermediate Temperature Proton Conducting Electrolytes

    DEFF Research Database (Denmark)

    Huang, Yunjie; Li, Q.F.; Pan, Chao

    2012-01-01

    A series of metal phosphates were synthesized and screened as potential proton conductor electrolytes for fuel cells and electrolysers operational at intermediate temperatures. Among the selected, niobium and bismuth phosphates exhibited a proton conductivity of 10-2 and 10-7 S cm-1, respectively......, under the anhydrous atmosphere at 250 °C, showing close correlation with the presence of hydroxyl groups in the phosphate phases. At the water partial pressure of above 0.6 atm, both phosphates possessed a proton conductivity to a level of above 3 x 10-2 S cm-1. Reasonable stability of the proton...... conductivity was observed under either a constant low water partial pressure or under a humidity cycling test within a period of more than 80 hours....

  19. Development of a fully injectable calcium phosphate cement for ...

    Indian Academy of Sciences (India)

    Unknown

    2003-01-27

    Jan 27, 2003 ... excellent alloplastic material for osseous augmentation because of the ... and basic calcium phosphate compounds on wetting with an aqueous ... ment of acute fracture of the radius through percutaneous administration of ...

  20. Transmission spectra study of sulfate substituted potassium dihydrogen phosphate

    KAUST Repository

    LI, LIANG; Zhang, Jianqin; Sun, Xun; Zhang, Qiang; Zhao, Xian; Zhang, Xixiang

    2013-01-01

    Potassium dihydrogen phosphate (KDP) crystals with different amounts of sulfate concentration were grown and the transmittance spectrum was studied. A crystal with high sulfate replacement density exhibits heavy absorption property

  1. Root developmental adaptation to phosphate starvation: better safe than sorry.

    Science.gov (United States)

    Péret, Benjamin; Clément, Mathilde; Nussaume, Laurent; Desnos, Thierry

    2011-08-01

    Phosphorus is a crucial component of major organic molecules such as nucleic acids, ATP and membrane phospholipids. It is present in soils in the form of inorganic phosphate (Pi), which has low availability and poor mobility. To cope with Pi limitations, plants have evolved complex adaptive responses that include morphological and physiological modifications. This review describes how the model plant Arabidopsis thaliana adapts its root system architecture to phosphate deficiency through inhibition of primary root growth, increase in lateral root formation and growth and production of root hairs, which all promote topsoil foraging. A better understanding of plant adaptation to low phosphate will open the way to increased phosphorus use efficiency by crops. Such an improvement is needed in order to adjust how we manage limited phosphorus stocks and to reduce the disastrous environmental effects of phosphate fertilizers overuse. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. [Phosphate binders in chronic kidney disease: the positions of sevelamer].

    Science.gov (United States)

    Fomin, V V; Shilov, E M; Svistunov, A A; Milovanov, Iu S

    2013-01-01

    The paper shows the role of phosphate binders in the correction of phosphorus and calcium metabolic disturbances in chronic kidney disease. The results of clinical trials demonstrating the efficacy and safety of sevelamer are discussed.

  3. Phosphate Rock Dissolution and Availability in Some Soils of Semi ...

    African Journals Online (AJOL)

    Fiifi Baidoo

    crop production with less expensive indigenous phosphate rocks (PRs) merits the attention of ... spectrophoto-meter at 712 nm following the procedure of Murphy & Riley (1962). Laboratory analyses ..... L. M. and Goh K. M. (1989). Effects of ...

  4. physico-chemical characterization of ogun and sokoto phosphate ...

    African Journals Online (AJOL)

    indicating their liming potential in the soil. ORP was more soluble in ... industry as a source of uranium and rare earth metals, ... limestones; and primary phosphatic shales, limestones ..... may help to reduce P leaching and run off losses after.

  5. Effectiveness and cost-efficiency of phosphate binders in hemodialysis

    Directory of Open Access Journals (Sweden)

    Zsifkovits, Johannes

    2009-06-01

    Full Text Available Health political background: In 2006, the prevalence of chronic renal insufficiency in Germany was 91,718, of which 66,508 patients were on dialysis. The tendency is clearly growing. Scientific background: Chronic renal insufficiency results in a disturbance of the mineral balance. It leads to hyperphosphataemia, which is the strongest independent risk factor for mortality in renal patients. Usually, a reduction in the phosphate intake through nutrition and the amount of phosphate filtered out during dialysis are not sufficient to reduce the serum phosphate values to the recommended value. Therefore, phosphate binders are used to bind ingested phosphate in the digestive tract in order to lower the phosphate concentration in the serum. Four different groups of phosphate binders are available: calcium- and aluminium salts are the traditional therapies. Sevelamer and Lanthanum are recent developments on the market. In varying doses, all phosphate binders are able to effectively lower phosphate concentrations. However, drug therapies have achieved recommended phosphate levels in only 50 percent of patients during the last years. Research questions: How effective and efficient are the different phosphate binders in chronic renal insufficient patients? Methods: The systematic literature search yielded 1,251 abstracts. Following a two-part selection process with predefined criteria 18 publications were included in the assessment. Results: All studies evaluated conclude that serum phosphate, serum calcium and intact parathyroid hormone can be controlled effectively with all phosphate binders. Only the number of episodes of hypercalcaemia is higher when using calcium-containing phosphatebinders compared to Sevelamer and Lanthanum. Regarding the mortality rate, the cardiovascular artery calcification and bone metabolism no definite conclusions can be drawn. In any case, the amount of calcification at study start seems to be crucial for the further

  6. Adsorption of 2-mercaptobenzothiazole on copper surface from phosphate solutions

    International Nuclear Information System (INIS)

    Kazansky, L.P.; Selyaninov, I.A.; Kuznetsov, Yu.I.

    2012-01-01

    Analysis of the electrochemical and XPS results has shown that adsorption of 2-mercaptobenzothiazole (MBT) on copper electrodes in neutral phosphate solutions proceeds through the formation of the chemical bonds by copper (I) cations with exo-sulfur and nitrogen atoms. A protection layer formed of Cu(I)MBT complex prevents precipitation of copper (II) phosphate on a copper surface. The thickness of the surface film consisting of a complex [Cu(I)MBT] n (having probably polymeric nature), where MBT acts as at least three-dentate ligand, increases depending on the exposure time, reaching 8-9 nm after immersing for 12 h in test solution. Even in a case of the preliminary formation of copper (II) phosphate on the copper electrode at the anodic potential addition of small amounts of MBT results in complete removal of copper (II) phosphate from the surface.

  7. Characterization of cement calcium phosphate for use dental

    International Nuclear Information System (INIS)

    Barros, C.M.B.; Oliveira, S.V.; Silva, M.C.; Marques, J.B.; Fook, M.V.L.

    2011-01-01

    Calcium phosphates are interesting biological and medical attention due to its occurrence in different animal species and humans. Ceramics based on calcium phosphate in the form of implants or porous particulate materials, have proven to be suitable replacements for bone tissue when they are only subjected to small mechanical stresses. Was obtained research laboratory DEMA/UFCG a calcium phosphate phase. The goal is to characterize the material by X-ray diffraction (XRD) in order to analyze what the phases and infrared spectroscopy (FTIR) to identify the absorption bands of the bonding characteristic. Was identified by XRD phase present in the sample is hydroxyapatite Ca/P 1.67. In infrared spectroscopy has absorption bands characteristic of the phosphate group at 1032 cm1 region. (author)

  8. Favourable uranium–phosphate exploration trends guided by the ...

    Indian Academy of Sciences (India)

    by the application of statistical factor analysis technique ... Keywords. Phosphate and uranium prospecting; aerial spectrometry survey; stratigraphic–structural traps; Syrian desert;. Syria. ... level, this linearity was not as good (Jubeli 1997).

  9. Proton transport properties of tin phosphate, chromotropic acid ...

    Indian Academy of Sciences (India)

    The functionalized materials of tin (IV) phosphate (SnP) like chromotropic acid anchored tin ... elemental analysis (ICP–AES), thermal analysis, X-ray analysis and FTIR spectroscopy. .... nal level below 1 V, interfaced to a minicomputer for data.

  10. Investigation of Wear Coefficient of Manganese Phosphate Coated Tool Steel

    Directory of Open Access Journals (Sweden)

    S. Ilaiyavel

    2013-03-01

    Full Text Available In recent years the properties of the coating in terms of wear resistance is of paramount importance in order to prevent the formation of severe damages. In this study, Wear coefficient of uncoated, Manganese Phosphate coated, Manganese Phosphate coated with oil lubricant, Heat treated Manganese Phosphate coated with oil lubricant on AISI D2 steels was investigated using Archard’s equation. The wear tests were performed in a pin on disk apparatus as per ASTM G-99 Standard. The volumetric wear loss and wear coefficient were evaluated through pin on disc test using a sliding velocity of 3.0 m/s under normal load of 40 N and controlled condition of temperature and humidity. Based on the results of the wear test, the Heat treated Manganese Phosphate with oil lubricant exhibited the lowest average wear coefficient and the lowest wear loss under 40 N load.

  11. Phosphate bonded ceramics as candidate final-waste-form materials

    International Nuclear Information System (INIS)

    Singh, D.; Wagh, A.S.; Cunnane, J.; Sutaria, M.; Kurokawa, S.; Mayberry, J.

    1994-04-01

    Room-temperature setting phosphate-bonded ceramics were studied as candidate materials for stabilization of DOE low-level problem mixed wastes which cannot be treated by other established stabilization techniques. Phosphates of Mg, Mg-Na, Al and Zr were studied to stabilize ash surrogate waste containing RCRA metals as nitrates and RCRA organics. We show that for a typical loading of 35 wt.% of the ash waste, the phosphate ceramics pass the TCLP test. The waste forms have high compression strength exceeding ASTM recommendations for final waste forms. Detailed X-ray diffraction studies and differential thermal analyses of the waste forms show evidence of chemical reaction of the waste with phosphoric acid and the host matrix. The SEM studies show evidence of physical bonding. The excellent performance in the leaching tests is attributed to a chemical solidification and physical as well as chemical bonding of ash wastes in these phosphate ceramics

  12. application of ascorbic acid 2-phosphate as a new voltammetric

    African Journals Online (AJOL)

    a

    acid 2-phosphate (AAP) as a new voltammetric substrate has been described in this paper. In the alkaline buffer .... ALP labeled goat anti-rabbit ..... Classical Michaelis-Menten kinetic experiments were carried out to measure the maximum.

  13. Intercomparison of radon emanation in Moroccan and Tunisian phosphate rocks

    International Nuclear Information System (INIS)

    Khalil, A.; Membrey, F.; Klein, D.; Chambaudet, A.; Iraqui, R.

    1992-01-01

    We suggest a method for measuring the emanation of radon gas of phosphates mineral from different origins using solid state track nuclear detectors (CR39 and LR115) with the aim to determinate radioactivity effects on the human. (author)

  14. Preparation and Characterization of Apatitic Biphasic Calcium Phosphate

    International Nuclear Information System (INIS)

    Thin Thin Nwe; Kyaw Naing; Khin Mar Tun; Nyunt Wynn

    2005-09-01

    The apatitic biphasic calcium phosphate (ABcp) consisting of hydroxyapatite (HA) and -tricalcium phosphate ( -Tcp) has been prepared by precipitation technique using slaked lime and orthophosphoric acid. The X-ray diffraction analysis of the product I (hydroxyapatite) revealed that ABcp was partially crystalline state. However, on heating at 800 C for 8 hrs, XRD pattern indicated a perfectly crystalline form of ABcp. This observation was supported by FT-IR measurement. The change in morphology regarding in the functional nature was infered by the shift in the FT-IR frequency. The optimization of the apatitic biphasic calcium phosphate was done by the variation of disodium hydrogen phosphate concentration, setting time, hardening time as well as compressive strength. The perpared cement may be used as an artificial substitution bone

  15. Regularities in Low-Temperature Phosphatization of Silicates

    Science.gov (United States)

    Savenko, A. V.

    2018-01-01

    The regularities in low-temperature phosphatization of silicates are defined from long-term experiments on the interaction between different silicate minerals and phosphate-bearing solutions in a wide range of medium acidity. It is shown that the parameters of the reaction of phosphatization of hornblende, orthoclase, and labradorite have the same values as for clayey minerals (kaolinite and montmorillonite). This effect may appear, if phosphotization proceeds, not after silicate minerals with a different structure and composition, but after a secondary silicate phase formed upon interaction between silicates and water and stable in a certain pH range. Variation in the parameters of the reaction of phosphatization at pH ≈ 1.8 is due to the stability of the silicate phase different from that at higher pH values.

  16. 3D printing of octacalcium phosphate bone substitutes

    Directory of Open Access Journals (Sweden)

    Vladimir S. Komlev

    2015-06-01

    Full Text Available Biocompatible calcium phosphate ceramic grafts are able of supporting new bone formation in appropriate environment. The major limitation of these materials usage for medical implants is the absence of accessible methods for their patient-specific fabrication. 3D printing methodology is an excellent approach to overcome the limitation supporting effective and fast fabrication of individual complex bone substitutes. Here we proposed a relatively simple route for 3D printing of octacalcium phosphates in complexly shaped structures by the combination of inkjet printing with post-treatment methodology. The printed octacalcium phosphate blocks were further implanted in the developed cranial bone defect followed by histological evaluation. The obtained result confirmed the potential of the developed octacalcium phosphates bone substitutes, which allowed 2.5-time reducing of defect’s diameter at 6.5 months in a region where native bone repair is extremely inefficient.

  17. Evaluation of the influence of nitrogen fixing, phosphate solubilizing ...

    African Journals Online (AJOL)

    Three biofertilizers nitrobein, phosphorein, and potash, containing nitrogen fixing, phosphate solubilizing, and potash mobilizing microorganisms, respectively were studied in peanut (Arachis hypogea L.) and sunflower (Helianthus annuus L.). Amendment with each of these biofertilizers enhanced different growth ...

  18. Hydrogen-bonding patterns involving a cyclic phosphate

    Indian Academy of Sciences (India)

    Administrator

    Phosphates, which always have electronegative oxygen atoms, bear no exception in their involvement in ... water makes the study of structural patterns due to H-bonding much too complicated. We ... H-bonding features found in all the above.

  19. Biomimetic calcium phosphate coatings on recombinant spider silk fibres

    NARCIS (Netherlands)

    Yang, Liang; Hedhammar, My; Blom, Tobias; Leifer, Klaus; Johansson, Jan; Habibovic, Pamela; van Blitterswijk, Clemens

    2010-01-01

    Calcium phosphate ceramic coatings, applied on surfaces of metallic and polymeric biomaterials, can improve their performance in bone repair and regeneration. Spider silk is biocompatible, strong and elastic, and hence an attractive biomaterial for applications in connective tissue repair. Recently,

  20. Oxidation of caffeine by phosphate radical anion in aqueous ...

    Indian Academy of Sciences (India)

    Unknown

    reactions in our body generate reactive oxygen species mainly comprising free radicals .... caffeine might be acting as a sensitizer to transfer energy to PDP to produce phosphate ... The lifetime of the excited singlet 21 state of caffeine is of the.

  1. Crude oil degradation by phosphate-solubilizing bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, M.J.B.D.; Nair, S.; David, J.J.; Chandramohan, D.

    Phosphate-solubilizing bacteria were isolated from tropical areas around the Indian peninsula. Two of the isolates showed high phosphatase activity. The isolates were identified as Klebsiella pneumoniae and Bacillus pumilus, and they showed high...

  2. Structural Isosteres of Phosphate Groups in the Protein Data Bank.

    Science.gov (United States)

    Zhang, Yuezhou; Borrel, Alexandre; Ghemtio, Leo; Regad, Leslie; Boije Af Gennäs, Gustav; Camproux, Anne-Claude; Yli-Kauhaluoma, Jari; Xhaard, Henri

    2017-03-27

    We developed a computational workflow to mine the Protein Data Bank for isosteric replacements that exist in different binding site environments but have not necessarily been identified and exploited in compound design. Taking phosphate groups as examples, the workflow was used to construct 157 data sets, each composed of a reference protein complexed with AMP, ADP, ATP, or pyrophosphate as well other ligands. Phosphate binding sites appear to have a high hydration content and large size, resulting in U-shaped bioactive conformations recurrently found across unrelated protein families. A total of 16 413 replacements were extracted, filtered for a significant structural overlap on phosphate groups, and sorted according to their SMILES codes. In addition to the classical isosteres of phosphate, such as carboxylate, sulfone, or sulfonamide, unexpected replacements that do not conserve charge or polarity, such as aryl, aliphatic, or positively charged groups, were found.

  3. Phosphate adsorption using modified iron oxide-based sorbents

    Data.gov (United States)

    U.S. Environmental Protection Agency — Phosphate Removal. This dataset is associated with the following publication: Lalley , J., C. Han , G. RamMohan , T. Speth , J. Garland , M. Nadagouda , and D....

  4. A review paper on biomimetic calcium phosphate coatings

    NARCIS (Netherlands)

    Lin, X.; de Groot, K.; Wang, D.; Hu, Q.; Wismeijer, D.; Liu, Y.

    2015-01-01

    Biomimetic calcium phosphate coatings have been developed for bone regeneration and repair because of their biocompatibility, osteoconductivity, and easy preparation. They can be rendered osteoinductive by incorporating an osteogenic agent, such as bone morphogenetic protein 2 (BMP-2), into the

  5. Phosphate homeostasis in Bartter syndrome: a case-control study.

    Science.gov (United States)

    Bettinelli, Alberto; Viganò, Cristina; Provero, Maria Cristina; Barretta, Francesco; Albisetti, Alessandra; Tedeschi, Silvana; Scicchitano, Barbara; Bianchetti, Mario G

    2014-11-01

    Bartter patients may be hypercalciuric. Additional abnormalities in the metabolism of calcium, phosphate, and calciotropic hormones have occasionally been reported. The metabolism of calcium, phosphate, and calciotropic hormones was investigated in 15 patients with Bartter syndrome and 15 healthy subjects. Compared to the controls, Bartter patients had significantly reduced plasma phosphate {mean [interquartile range]:1.29 [1.16-1.46] vs. 1.61 [1.54-1.67] mmol/L} and maximal tubular phosphate reabsorption (1.16 [1.00-1.35] vs. 1.41 [1.37-1.47] mmol/L) and significantly increased parathyroid hormone (PTH) level (6.1 [4.5-7.7] vs. 2.8 [2.2-4.4] pmol/L). However, patients and controls did not differ in blood calcium, 25-hydroxyvitamin D, alkaline phosphatase, and osteocalcin levels. In patients, an inverse correlation (P Bartter patients.

  6. How to assess the efficacy of phosphate binders

    Directory of Open Access Journals (Sweden)

    Francisco Caravaca

    2017-05-01

    Conclusions: The proposed parameter Pu/PCR may reflect the rate of intestinal phosphate absorption, and therefore, its variations after PB prescription may be a useful tool for estimating the pharmacological efficacy of these drugs.

  7. Genetics Home Reference: pyridoxal 5'-phosphate-dependent epilepsy

    Science.gov (United States)

    ... phosphate oxidase. This enzyme is involved in the conversion (metabolism) of vitamin B6 derived from food (in ... Related Information What does it mean if a disorder seems to run in my family? What are ...

  8. Reaction of Thymidine with Hypobromous Acid in Phosphate Buffer.

    Science.gov (United States)

    Suzuki, Toshinori; Kitabatake, Akihiko; Koide, Yuki

    2016-01-01

    When thymidine was treated with hypobromous acid (HOBr) in 100 mM phosphate buffer at pH 7.2, two major product peaks appeared in the HPLC chromatogram. The products in each peak were identified by NMR and MS as two isomers of 5-hydroxy-5,6-dihydrothymidine-6-phosphate (a novel compound) and two isomers of 5,6-dihydroxy-5,6-dihydrothymidine (thymidine glycol) with comparable yields. 5-Hydroxy-5,6-dihydrothymidine-6-phosphate was relatively stable, and decomposed with a half-life of 32 h at pH 7.2 and 37°C generating thymidine glycol. The results suggest that 5-hydroxy-5,6-dihydrothymidine-6-phosphate in addition to thymidine glycol may have importance for mutagenesis by the reaction of HOBr with thymine residues in nucleotides and DNA.

  9. Investigation of the benzotriazole as addictive for carbon steel phosphating

    International Nuclear Information System (INIS)

    Annies, V.; Cunha, M.T.; Rodrigues, P.R.P.; Banczek, E.P.; Terada, M.

    2010-01-01

    This work studied the viability of substitution of sodium nitrite (NaNO 2 ) for benzotriazole (BTAH) in the zinc phosphate bath (PZn+NaNO 2 ) for phosphating of carbon steel (SAE 1010). The characterization of the samples was carried out by Scanning Electron Microscopy, Optical Microscopy and X-ray diffraction. The chemical composition was evaluated by Energy Dispersive Spectroscopy. The corrosion behavior of the samples was investigated by Open Circuit Potential, Electrochemical Impedance Spectroscopy and Anodic Potentiodynamic Polarization Curves in a 0.5 mol L -1 NaCl electrolyte. The experimental results showed that the phosphate layer obtained in the solution with benzotriazole (PZn+BTAH) presented better corrosion resistance properties than that obtained in sodium nitrite. The results demonstrated that the sodium nitrite NaNO 2 can be replaced by benzotriazole (BTAH) in zinc phosphate baths. (author)

  10. Stimulation of Suicidal Erythrocyte Death by Increased Extracellular Phosphate Concentrations

    Directory of Open Access Journals (Sweden)

    Jakob Voelkl

    2014-02-01

    Full Text Available Background/Aim: Anemia in renal insufficiency results in part from impaired erythrocyte formation due to erythropoietin and iron deficiency. Beyond that, renal insufficiency enhances eryptosis, the suicidal erythrocyte death characterized by phosphatidylserine-exposure at the erythrocyte surface. Eryptosis may be stimulated by increase of cytosolic Ca2+-activity ([Ca2+]i. Several uremic toxins have previously been shown to stimulate eryptosis. Renal insufficiency is further paralleled by increase of plasma phosphate concentration. The present study thus explored the effect of phosphate on erythrocyte death. Methods: Cell volume was estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, and [Ca2+]i from Fluo3-fluorescence. Results: Following a 48 hours incubation, the percentage of phosphatidylserine exposing erythrocytes markedly increased as a function of extracellular phosphate concentration (from 0-5 mM. The exposure to 2 mM or 5 mM phosphate was followed by slight but significant hemolysis. [Ca2+]i did not change significantly up to 2 mM phosphate but significantly decreased at 5 mM phosphate. The effect of 2 mM phosphate on phosphatidylserine exposure was significantly augmented by increase of extracellular Ca2+ to 1.7 mM, and significantly blunted by nominal absence of extracellular Ca2+, by additional presence of pyrophosphate as well as by presence of p38 inhibitor SB203580. Conclusion: Increasing phosphate concentration stimulates erythrocyte membrane scrambling, an effect depending on extracellular but not intracellular Ca2+ concentration. It is hypothesized that suicidal erythrocyte death is triggered by complexed CaHPO4.

  11. Dental Composites with Calcium / Strontium Phosphates and Polylysine.

    Directory of Open Access Journals (Sweden)

    Piyaphong Panpisut

    Full Text Available This study developed light cured dental composites with added monocalcium phosphate monohydrate (MCPM, tristrontium phosphate (TSrP and antimicrobial polylysine (PLS. The aim was to produce composites that have enhanced water sorption induced expansion, can promote apatite precipitation and release polylysine.Experimental composite formulations consisted of light activated dimethacrylate monomers combined with 80 wt% powder. The powder phase contained a dental glass with and without PLS (2.5 wt% and/or reactive phosphate fillers (15 wt% TSrP and 10 wt% MCPM. The commercial composite, Z250, was used as a control. Monomer conversion and calculated polymerization shrinkage were assessed using FTIR. Subsequent mass or volume changes in water versus simulated body fluid (SBF were quantified using gravimetric studies. These were used, along with Raman and SEM, to assess apatite precipitation on the composite surface. PLS release was determined using UV spectroscopy. Furthermore, biaxial flexural strengths after 24 hours of SBF immersion were obtained.Monomer conversion of the composites decreased upon the addition of phosphate fillers (from 76 to 64% but was always higher than that of Z250 (54%. Phosphate addition increased water sorption induced expansion from 2 to 4% helping to balance the calculated polymerization shrinkage of ~ 3.4%. Phosphate addition promoted apatite precipitation from SBF. Polylysine increased the apatite layer thickness from ~ 10 to 20 μm after 4 weeks. The novel composites showed a burst release of PLS (3.7% followed by diffusion-controlled release irrespective of phosphate addition. PLS and phosphates decreased strength from 154 MPa on average by 17% and 18%, respectively. All formulations, however, had greater strength than the ISO 4049 requirement of > 80 MPa.The addition of MCPM with TSrP promoted hygroscopic expansion, and apatite formation. These properties are expected to help compensate polymerization shrinkage and

  12. Serum phosphate and cognitive function in older men.

    Science.gov (United States)

    Slinin, Yelena; Vo, Tien; Taylor, Brent C; Murray, Anne M; Schousboe, John; Langsetmo, Lisa; Ensrud, Kristine

    2018-01-01

    Determine whether serum phosphate is associated with concurrent cognitive impairment and subsequent cognitive decline in older men independent of demographic covariates and atherosclerotic risk factors. In a prospective study of 5529 men enrolled in the Osteoporotic Fractures in Men study, we measured baseline serum phosphate, baseline cognitive function, and change in cognitive function between baseline and follow-up exams an average of 4.6 years later using the Modified Mini-Mental State (3MS) Examination and Trails B. There was no association between serum phosphate and odds of cognitive impairment as assessed by baseline 3MS score or risk of cognitive decline as assessed by longitudinal change in 3MS score. Higher baseline serum phosphate was associated with higher odds of poor executive function as assessed by Trails B with fully adjusted odds ratios 1.12 (95% confidence interval: 0.83-1.52), 1.31 (0.97-1.77), and 1.45 (1.08-1.94) for men in the second, third, and fourth versus the bottom quartile (referent group) of serum phosphate (p-trend 0.007). However, higher phosphate level was not associated with risk of decline in executive function as assessed by longitudinal change in Trails B score with fully adjusted odds ratios 0.94 (95% confidence interval 0.69-1.28), 0.96 (0.70-1.32), and 1.21 (0.89-1.66) for men in the second, third, and fourth versus the bottom quartile (referent group) of serum phosphate (p-trend 0.22). Higher serum phosphate in older men was associated with a higher likelihood of poor executive function, but not with impaired global cognitive function or decline in executive or global cognition. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  13. Phosphate binding therapy in dialysis patients: focus on lanthanum carbonate

    Directory of Open Access Journals (Sweden)

    Ismail A Mohammed

    2008-11-01

    Full Text Available Ismail A Mohammed, Alastair J HutchisonManchester Institute of Nephrology and Transplantation, Manchester Royal Infirmary, Oxford Road, Manchester, UKAbstract: Hyperphosphatemia is an inevitable consequence of end stage chronic kidney disease and is present in the majority of dialysis patients. Recent observational data has associated hyperphosphatemia with increased cardiovascular mortality among dialysis patients. Dietary restriction of phosphate and current dialysis prescription practices are not enough to maintain serum phosphate levels within the recommended range so that the majority of dialysis patients require oral phosphate binders. Unfortunately, conventional phosphate binders are not reliably effective and are associated with a range of limitations and side effects. Aluminium-containing agents are highly efficient but no longer widely used because of well established and proven toxicity. Calcium based salts are inexpensive, effective and most widely used but there is now concern about their association with hypercalcemia and vascular calcification. Sevelamer hydrochloride is associated with fewer adverse effects, but a large pill burden and high cost are limiting factors to its wider use. In addition, the efficacy of sevelamer as a monotherapy in lowering phosphate to target levels in severe hyperphosphatemia remains debatable. Lanthanum carbonate is a promising new non-aluminium, calcium-free phosphate binder. Preclinical and clinical studies have demonstrated a good safety profile, and it appears well tolerated and effective in reducing phosphate levels in dialysis patients. Its identified adverse events are apparently mild to moderate in severity and mostly GI related. It appears to be effective as a monotherapy, with a reduced pill burden, but like sevelamer, it is significantly more expensive than calcium-based binders. Data on its safety profile over 6 years of treatment are now available.Keywords: hyperphosphatemia, lanthanum

  14. Study of electrochemical phosphate conversion coating of metallic surfaces

    International Nuclear Information System (INIS)

    Gougelin, Patrick

    1985-01-01

    After an overview on phosphate conversion coating processes, on models of iron electrochemical dissolution, on the passivation phenomenon, and on the phosphate conversion coating treatment, this research thesis reports a detailed study of this last process. The author presents the experimental method, reports the study of this process and of passivation under constant polarization. He reports the use of various techniques and conditions: chrono-amperometry, chrono-potentiometry, cyclic volt-amperometry

  15. Intercalation compounds of vanadium(5) phosphates with glycerol

    International Nuclear Information System (INIS)

    Yakovleva, T.N.; Vykhodtseva, K.I.; Tarasova, D.V.; Soderzhinova, M.M.

    1997-01-01

    Interaction products of glycerol aqueous solutions with vanadium(5) phosphates were investigated by the methods of ESR, X-ray phase and thermal analyses. It is shown that glycerol molecules enter the interlayer space of VOPO 4 · 2H 2 O lattice with formation of disordered intercalated compounds with glycerol on the basis of partially reduced vanadium phosphate form when using α-VOPO 4 . 16 refs., 4 figs., 1 tab

  16. Democracy and shareholder's participation

    Directory of Open Access Journals (Sweden)

    Radulović Vuk

    2014-01-01

    Full Text Available Democracy and participation of shareholders or the demand for their active participation in the meetings of the Assemblyhas increasingly gained in importance in modern conditions. This is because, negative trends of passivation, the limitations of democratic potential of shareholders and shareholders' rights abuse by the management body, especially in the work control and compensation policy of shareholders, have been observed in a detailed analysis of the application and results of the Shareholder Rights Directive. The passivity of shareholders, as one of the most striking features of their position in the joint stock company today, is the biggest problem and threat to democratic processes within the company. If we bear in mind that the most common definition of shareholder democracy is 'ability of shareholders to influence the management of the company', we can notice a clear picture of the seriousness and importance of the lack of shareholder participation. This is the reason why the author of this paper gradually examines the causes and consequences of the passivity of shareholders, the proposed changes in this context in the Law of the European Union and the practical implications of such solutions in practice. In addition, the author examines contemporary forms and conditions for shareholder democracy and the legal framework in the European Union and the Republic of Serbia. In this way, we analyze the situation in this area and point out shortcomings of certain solutions, as well as the implications they cause in practice. The main thesis from which starts the scientific work and which will be gradually proven through theoretical and practical analysis is that the wider social processes directly reflect on the state of the joint-stock companies, or the state of corporate governance. This means that the negative trends of modern democracy (in the constitutional sense are almost mirrored in economic capital (EC and our attempt in this paper

  17. International symposium on cellular and molecular biology of phosphate and phosphorylated compounds in microorganisms: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    This report contains the abstracts of papers presented at the conference. Attention is focused on the following topics: regulation of phosphate metabolism in bacteria; structure-function of alkaline phosphatase; regulation of phosphate metabolism in yeast; transport of phosphate and phosphorylated compounds; and phosphate regulation in pathogenesis and secondary metabolism.

  18. 40 CFR 422.40 - Applicability; description of the defluorinated phosphate rock subcategory.

    Science.gov (United States)

    2010-07-01

    ... defluorinated phosphate rock subcategory. 422.40 Section 422.40 Protection of Environment ENVIRONMENTAL... Defluorinated Phosphate Rock Subcategory § 422.40 Applicability; description of the defluorinated phosphate rock... phosphate rock by application of high temperature treatment along with wet process phosphoric acid, silica...

  19. Exploring the challenges associated with the greening of supply chains in the South African manganese and phosphate mining industry

    Directory of Open Access Journals (Sweden)

    R.I. David Pooe

    2014-11-01

    Full Text Available As with most mining activities, the mining of manganese and phosphate has serious consequences for the environment. Despite a largely adequate and progressive framework for environmental governance developed since 1994, few mines have integrated systems into their supply chain processes to minimise environmental risks and ensure the achievement of acceptable standards. Indeed, few mines have been able to implement green supply chain management (GrSCM. The purpose of this article was to explore challenges related to the implementation of GrSCM and to provide insight into how GrSCM can be implemented in the South African manganese and phosphate industry. This article reported findings of a qualitative study involving interviews with 12 participants from the manganese and phosphate industry in South Africa. Purposive sampling techniques were used. Emerging from the study were six themes, all of which were identified as key challenges in the implementation of GrSCM in the manganese and phosphate mining industry. From the findings, these challenges include the operationalisation of environmental issues, lack of collaboration and knowledge sharing, proper application of monitoring and control systems,lack of clear policy and legislative direction, the cost of implementing GrSCM practices, and the need for strong leadership and management of change. On the basis of the literature reviewed and empirical findings, conclusions were drawn and policy and management recommendations were accordingly made.

  20. Phosphate solubilization as a microbial strategy for promoting plant growth

    Directory of Open Access Journals (Sweden)

    Mayra Eleonora Beltrán Pineda

    2014-01-01

    Full Text Available Because of the constant application of chemical inputs in Agroecosystem, the cost of crop production and environmental quality of soil and water have been affected. Microorganisms carry out most biogeochemical cycles; therefore, their role is essential for agro ecosystem balance. One such functional group is the phosphate solubilizing microorganisms, which are recognized plant growth promoters. These microbial populations perform an important activity, since in many soils there are large reserves of insoluble phosphorus, as a result of fixing much of the phosphorus fertilizer applied, which cannot be assimilated by the plant. The phosphate solubilizing microorganisms use different solubilization mechanisms such as the production of organic acids, which solubilize theses insoluble phosphates in the rhizosphere region. Soluble phosphates are absorbed by the plant, which enhances their growth and productivity. By using these phosphate reserves in soils, application of chemical fertilizers is decreased, on the one hand, can again be fixed by ions Ca, Al or Fe making them insoluble and, by the other hand, increase the costs of crop production. Microbial populations have been widely studied in different types of ecosystems, both natural and Agroecosystem. Thanks to its effectiveness, in laboratory and field studies, the phosphate solubilizing phenotype is of great interest to microbial ecologists who have begun to establish the molecular basis of the traitr.

  1. Role of magnesium on the biomimetic deposition of calcium phosphate

    Science.gov (United States)

    Sarma, Bimal K.; Sarma, Bikash

    2016-10-01

    Biomimetic depositions of calcium phosphate (CaP) are carried out using simulated body fluid (SBF), calcifying solution and newly developed magnesium containing calcifying solution. Calcium phosphate has a rich phase diagram and is well known for its excellent biocompatibility and bioactivity. The most common phase is hydroxyapatite (HAp), an integral component of human bone and tooth, widely used in orthopedic and dental applications. In addition, calcium phosphate nanoparticles show promise for the targeted drug delivery. The doping of calcium phosphate by magnesium, zinc, strontium etc. can change the protein uptake by CaP nanocrystals. This work describes the role of magnesium on the nucleation and growth of CaP on Ti and its oxide substrates. X-ray diffraction studies confirm formation of HAp nanocrystals which closely resemble the structure of bone apatite when grown using SBF and calcifying solution. It has been observed that magnesium plays crucial role in the nucleation and growth of calcium phosphate. A low magnesium level enhances the crystallinity of HAp while higher magnesium content leads to the formation of amorphous calcium phosphate (ACP) phase. Interestingly, the deposition of ACP phase is rapid when magnesium ion concentration in the solution is 40% of calcium plus magnesium ions concentration. Moreover, high magnesium content alters the morphology of CaP films.

  2. PHOSPHATES REMOVAL FROM REJECT WATER FROM DIGESTION OF SLUDGE

    Directory of Open Access Journals (Sweden)

    Elżbieta Sperczyńska

    2016-06-01

    Full Text Available The aim of the research work was to evaluate if coagulants used on technical scale are useful in phosphates removal from reject water. Effectiveness of phosphorus compounds removal from reject water from digestion of sewage sludge was examined. Selected prehydrolysed alkaline aluminium polychlorides were used. The results were compared to the ones obtained with aluminium sulphate. Reject water from digestion of sewage sludge form WWTP of 100 000 PE were examined. Commercial agents – prehydrolysed PAX 18, PAX XL10, PAX-XL1905 as well as aluminium sulphate were used. Various doses of coagulants: 0.7; 1.0; 1.5 – time higher than stoichiometric dose were applied. Stoichiometric dose was calculated based on chemical reaction of insoluble aluminium phosphate formation. Concentrations of Kiejdahl nitrogen (891 mgNKj/dm3, phosphates (125 mgPO43-/dm3 and organic compounds - COD (592 mgO2/dm3 in reject water were very high. The effectiveness of coagulation process increased as the doses of chemical agents increased. The most effective doses were the highest ones used during the experiment. The most effective agent was PAX 18 (96% removal efficiency. As the phosphates concentration decreased COD content declined simultaneously. Maximum COD removal (47% was obtained when highly alkaline PAX XL 1905 was used. Use of the lowest dose of Al2(SO43 allowed for 50% phosphates removal, whereas the lowest dose of PAX 18 decreased phosphates concentration by 83%.

  3. Immobilization of fission products in phosphate ceramic waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Singh, D.; Wagh, A. [Argonne National Lab., IL (United States)

    1997-10-01

    Chemically bonded phosphate ceramics (CBPCs) have several advantages that make them ideal candidates for containing radioactive and hazardous wastes. In general, phosphates have high solid-solution capacities for incorporating radionuclides, as evidenced by several phosphates (e.g., monazites and apatites) that are natural analogs of radioactive and rare-earth elements. The phosphates have high radiation stability, are refractory, and will not degrade in the presence of internal heating by fission products. Dense and hard CBPCs can be fabricated inexpensively and at low temperature by acid-base reactions between an inorganic oxide/hydroxide powder and either phosphoric acid or an acid-phosphate solution. The resulting phosphates are extremely insoluble in aqueous media and have excellent long-term durability. CBPCs offer the dual stabilization mechanisms of chemical fixation and physical encapsulation, resulting in superior waste forms. The goal of this task is develop and demonstrate the feasibility of CBPCs for S/S of wastes containing fission products. The focus of this work is to develop a low-temperature CBPC immobilization system for eluted {sup 99}Tc wastes from sorption processes.

  4. Phosphate Framework Electrode Materials for Sodium Ion Batteries.

    Science.gov (United States)

    Fang, Yongjin; Zhang, Jiexin; Xiao, Lifen; Ai, Xinping; Cao, Yuliang; Yang, Hanxi

    2017-05-01

    Sodium ion batteries (SIBs) have been considered as a promising alternative for the next generation of electric storage systems due to their similar electrochemistry to Li-ion batteries and the low cost of sodium resources. Exploring appropriate electrode materials with decent electrochemical performance is the key issue for development of sodium ion batteries. Due to the high structural stability, facile reaction mechanism and rich structural diversity, phosphate framework materials have attracted increasing attention as promising electrode materials for sodium ion batteries. Herein, we review the latest advances and progresses in the exploration of phosphate framework materials especially related to single-phosphates, pyrophosphates and mixed-phosphates. We provide the detailed and comprehensive understanding of structure-composition-performance relationship of materials and try to show the advantages and disadvantages of the materials for use in SIBs. In addition, some new perspectives about phosphate framework materials for SIBs are also discussed. Phosphate framework materials will be a competitive and attractive choice for use as electrodes in the next-generation of energy storage devices.

  5. Synthesis and Characterization of Metal Phosphates for Photocatalytic Applications

    KAUST Repository

    Al-Sabban, Bedour

    2012-07-01

    Solar energy is the most abundant efficient and important source of renewable energy. The objective of this study is to develop highly efficient visible light responsive photocatalysts for overall water splitting. This is done by using silver or copper containing materials. Phosphate compounds have caught much attention due to their rigid structure, thermal stability and resistance to chemical attacks. Solid phosphates can be prepared by direct solid-state reaction between metal cations and phosphate anions at high temperatures. Double metal phosphates of the Nasion-type structure had shown further technological importance. It has been reported that well-crystallized double metal phosphate particles have excellent ordering and cationic conduction channels in the Nasicon framework. In this study, several Nasion-type structured materials have been synthesized by solid-state method (e.g. CuTi2(PO4)3 and AgTi2(PO4)3) heated up under different temperatures (400–1100C) in N2 or air atmosphere. These materials were characterized by XRD, SEM, DR-UV-Vis spectroscopy and tested for photocatalytic applications. A new method for direct synthesis of photoelectrode on Ti Plate had been demonstrated. Further investigations on controlling the size and morphology for better performance of single and double metal phosphates will be done.

  6. Adherence to phosphate binders in hemodialysis patients: prevalence and determinants.

    Science.gov (United States)

    Van Camp, Yoleen P M; Vrijens, Bernard; Abraham, Ivo; Van Rompaey, Bart; Elseviers, Monique M

    2014-12-01

    Phosphate control is a crucial treatment goal in end-stage renal disease, but poor patient adherence to phosphate binder therapy remains a challenge. This study aimed to estimate the extent of phosphate binder adherence in hemodialysis patients and to identify potential determinants. Phosphate binder adherence was measured blindly in 135 hemodialysis patients for 2 months using the medication event monitoring system. Patient data, gathered at inclusion through medical records, ad hoc questionnaires and the short form (SF)-36 health survey, included: (1) demographics, (2) perceived side-effects, belief in benefit, self-reported adherence to the therapy, (3) knowledge about phosphate binder therapy, (4) social support, and (5) quality of life (SF-36). Phosphatemia data was collected from charts. 'Being adherent' was defined as missing adherent' as missing adherent. Over the entire 8-week period, 22 % of patients were totally adherent. Mean phosphatemia levels were 0.55 mg/dl lower in adherent than nonadherent patients (4.76 vs. 5.31 mg/dl). Determinants for being totally adherent were living with a partner, higher social support (both were interrelated) and higher physical quality of life. Experiencing intake-related inconvenience negatively affected adherence. The social support and quality of life physical score explained 26 % of the variance in adherence. Phosphate binder nonadherence remains a major problem. Interventions should aim, at least, to improve social support. With few associated factors found and yet low adherence, an individualized approach seems indicated.

  7. Metal Phosphides and Phosphates-based Electrodes for Electrochemical Supercapacitors.

    Science.gov (United States)

    Li, Xin; Elshahawy, Abdelnaby M; Guan, Cao; Wang, John

    2017-10-01

    Phosphorus compounds, such as metal phosphides and phosphates have shown excellent performances and great potential in electrochemical energy storage, which are demonstrated by research works published in recent years. Some of these metal phosphides and phosphates and their hybrids compare favorably with transition metal oxides/hydroxides, which have been studied extensively as a class of electrode materials for supercapacitor applications, where they have limitations in terms of electrical and ion conductivity and device stability. To be specific, metal phosphides have both metalloid characteristics and good electric conductivity. For metal phosphates, the open-framework structures with large channels and cavities endow them with good ion conductivity and charge storage capacity. In this review, we present the recent progress on metal phosphides and phosphates, by focusing on their advantages/disadvantages and potential applications as a new class of electrode materials in supercapacitors. The synthesis methods to prepare these metal phosphides/phosphates are looked into, together with the scientific insights involved, as they strongly affect the electrochemical energy storage performance. Particular attentions are paid to those hybrid-type materials, where strong synergistic effects exist. In the summary, the future perspectives and challenges for the metal phosphides, phosphates and hybrid-types are proposed and discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Effect of phosphate supplementation on oxygen delivery at high altitude

    Science.gov (United States)

    Jain, S. C.; Singh, M. V.; Rawal, S. B.; Sharma, V. M.; Divekar, H. M.; Tyagi, A. K.; Panwar, M. R.; Swamy, Y. V.

    1987-09-01

    In the present communication, effect of low doses of phosphate supplementation on short-term high altitude adaptation has been examined. Studies were carried out in 36 healthy, male, sea-level residents divided in a double blind fashion into drug and placebo treated groups. 3.2 mmol of phosphate were given orally to each subject of the drug treated group once a day for 4 days on arrival at an altitude of 3,500 m. Sequential studies were done in the subjects in both groups on the 3rd, 7th, 14th and 21st day of their altitude stay. Haemoglobin, haematocrit, erythrocyte and reticulocyte counts increased to the similar extent in both groups. Blood pH, pO2 and adenosine tri-phosphate (ATP) did not differ between the two groups. On 3rd day of the altitude stay, inorganic phosphate and 2,3-diphosphoglycerate (2,3 DPG) levels in the drug treated group increased significantly as compared to the placebo group. No significant difference in inorganic phosphate and 2,3 DPG was observed later on in the two groups. Psychological and clinical tests also indicated that the drug treated subjects felt better as compared to the placebo treated subjects. The present study suggests that low doses of phosphate increases circulating 2,3-DPG concentration which in turn brings about beneficial effect towards short term high altitude adaptation.

  9. Effect of Phosphate levels on vegetables irrigated with wastewater

    Science.gov (United States)

    Oladeji, S. O.; Saeed, M. D.

    2018-04-01

    This study examined accumulation of phosphate ions in wastewater and vegetables through man-made activities. Phosphate level was determined in wastewater and vegetables collected on seasonal basis along Kubanni stream in Zaria using UV/Visible and Smart Spectro Spectrophotometers for their analyses. Results obtained show that phosphate concentrations ranged from 3.85 – 42.33 mg/L in the first year and 15.60 – 72.80 mg/L in the second year for wastewater whereas the vegetable had levels of 3.80 – 23.65 mg/kg in the year I and 7.48 – 27.15 mg/kg in the year II. Further statistical tests indicated no significant difference in phosphate levels across the locations and seasons for wastewater and vegetables evaluated. Correlation results for these two years indicated negative (r = -0.062) relationship for wastewater while low (r = 0.339) relationship noticed for vegetables planted in year I to that of year II. Phosphate concentrations obtained in this study was higher than Maximum Contaminant Levels set by Standard Organization such as WHO and FAO for wastewater whereas vegetables of the sampling sites were not contaminated with phosphate ions. Irrigating farmland with untreated wastewater has negative consequence on the crops grown with it.

  10. A phosphate transporter from the mycorrhizal fungus Glomus versiforme.

    Science.gov (United States)

    Harrison, M J; van Buuren, M L

    1995-12-07

    Vesicular-arbuscular (VA) mycorrhizal fungi form symbiotic associations with the roots of most terrestrial plants, including many agriculturally important crop species. The fungi colonize the cortex of the root to obtain carbon from their plant host, while assisting the plant with the uptake of phosphate and other mineral nutrients from the soil. This association is beneficial to the plant, because phosphate is essential for plant growth and development, especially during growth under nutrient-limiting conditions. Molecular genetic studies of these fungi and their interaction with plants have been limited owing to the obligate symbiotic nature of the VA fungi, so the molecular mechanisms underlying fungal-mediated uptake and translocation of phosphate from the soil to the plant remain unknown. Here we begin to investigate this process by identifying a complementary DNA that encodes a transmembrane phosphate transporter (GvPT) from Glomus versiforme, a VA mycorrhizal fungus. The function of the protein encoded by GvPT was confirmed by complementation of a yeast phosphate transport mutant. Expression of GvPT was localized to the external hyphae of G. versiforme during mycorrhizal associations, these being the initial site of phosphate uptake from the soil.

  11. Radiation exposure due to agricultural uses of phosphate fertilizers

    International Nuclear Information System (INIS)

    Khater, Ashraf E.M.; AL-Sewaidan, H.A.

    2008-01-01

    Radiological impacts of phosphate rocks mining and manufacture could be significant due to the elevated radioactivity contents of the naturally occurring radioactive materials (NORM), such as 238 U series, 232 Th series and 40 K, in some phosphate deposits. Over the last decades, the land reclamation and agriculture activities in Saudi Arabia and other countries have been widely expanded. Therefore, the usage of chemical fertilizers is increased. Selected phosphate fertilizers samples were collected and the specific activities of NORM were measured using a gamma ray spectrometer based on a hyper pure germanium detector and alpha spectrometer based on surface barrier detector. The obtained results show remarkable wide variations in the radioactivity contents of the different phosphate fertilizer samples. The mean (ranges) of specific activities for 226 Ra, 210 Po, 232 Th and 40 K, and radium equivalent activity are 75 (3-283), 25 (0.5-110), 23 (2-74), 2818 (9-6501) Bq/kg and 283 (7-589) Bq/kg, respectively. Based on dose calculations, the increment of the public radiation exposure due to the regular agricultural usage of phosphate fertilizers is negligible. Its average value 1 m above the ground is about 0.12 nGy/h where the world average value due to the NORM in soil is 51 nGy/h. Direct radiation exposures of the farmers due to phosphate fertilizers application was not considered in our study

  12. A novel biphasic calcium phosphate derived from fish otoliths

    Science.gov (United States)

    Montañez-Supelano, N. D.; Sandoval-Amador, A.; Estupiñan-Durán, H. A.; Y Peña-Ballesteros, D.

    2017-12-01

    Calcium phosphates are bioceramics that have been widely used as bone substitutes because they encourage the formation of bone on their surface and can improve the healing of the bone. Hydroxyapatite HA (calcium/phosphorus ratio of 1.67) and tricalcium phosphate TCP (calcium/phosphorus ratio of 1.50) are the most common calcium phosphates. Natural materials have begun to be tested to make HA or TCP such as shells of cardiidae (family of mollusks) and eggshells. The calcium phosphate obtained has a high ability to precipitate apatite. In this work, the mixed phase ceramic of beta-Tri-calcium phosphate / hydroxyapatite (β-TCP/HA) was synthesized by aqueous precipitation from fish otoliths, which are monomineralic species composed of aragonite. Otoliths of the specie Plagioscion squamosissimus, commonly called the river croaker, were used. Techniques such as DRX, Raman spectroscopy and SEM-EDS were used to characterize the raw material and the obtained material. X-ray diffraction analysis revealed the presence of two crystalline phases of calcium phosphates with 86.2% crystallinity. SEM micrographs showed agglomeration of particles with porous structure and submicron particle sizes.

  13. Public education and participation

    International Nuclear Information System (INIS)

    Kelly, J.E.

    1982-01-01

    As prescribed in Step 1 of the Public Education and Participation Process (attachment 1), industry, public interest groups, and decision-makers were briefed about the Subseabed Disposal Program. In regard to public interest groups, Drs. Hollister and Kelly were invited to present the technical and policy aspects of the Subseabed Program at a public forum in Hawaii sponsored by the Hawaii League of Women Voters, the Health Physics Society, and the East-West Center. The sponsors videotaped the forum for a film, entitled Slowly Dying Embers: Radioactive Waste and the Pacific, which will be shown on television in Hawaii. In response to requests for information about the Subseabed Program, Congressional Staff, Representatives, and Senators (attachment 2) were briefed about the Subseabed Program as legislation related to the Program moved through Congress (attachment 3). Science oriented publications also were contacted about the Program

  14. Lifelong learning and participation

    DEFF Research Database (Denmark)

    Rothuizen, Jan Jaap; Molpeceres, Mariangeles; Hansen, Helle Krogh

    2014-01-01

    in involvement of older people in voluntary social work as mentors for young people. The challenge of the ageing societies is quite often discussed as the ‘burden of the elderly’ and discussed as an economic problem. However, the challenge is not only economical. It is also a social and cultural challenge, among...... other things because a unilateral focus on the economic aspects may cause dissolution of the social cohesion and decrease in well-being for far too many people. The HEAR ME project aimed at developing strategies for lifelong learning and new roles for older people based on their competences, network...... and an assumed desire of generativity. Action learning seems to be an appropriate learning concept in relation to keeping older people engaged in the community. The authors thus point at participating and lifelong learning as part of the answers to the demographic challenges, and they suggest what you might call...

  15. Public Participation Plan

    International Nuclear Information System (INIS)

    1984-06-01

    The purpose of this Public Participation Plan is to describe the Department of Energy's plan for involving the public in the decision-making process required by the National Environmental Policy Act (NEPA) of 1969 as related to the Uranium Mill Tailings Remedial Action (UMTRA) Project. This project was authorized by congress in the Uranium Mill Tailings Radiation Control Act of 1978, PL95-604. The Act provides for a cooperative effort with affected states and Indian tribes for the cleanup of designated inactive uranium mill tailings sites and associated vicinity properties, which are located in ten western states and in Pennsylvania. The Act was amended in 1982 to also include vicinity properties contaminated with residual radioactive material in Edgemont, South Dakota

  16. Barriers to public participation

    International Nuclear Information System (INIS)

    Patten, E.

    1986-01-01

    When one talks of public involvement, one immediately thinks of a public hearing. Six problems with the public hearing system are listed and discussed. The constraints involved in the public hearing process are: 1) asking for technical information from general folks; 2) overwhelming the public with complex information; 3) having a format that intimidates the speaker and allows no opportunity for useful dialogue; 4) obtaining a skewed picture of an issue because one hasn't had truly representative comments; 5) citizens having overblown expectations of what public involvement means, and becoming frustrated and cynical when their advice isn't heeded; and 6) convincing the powers that be that a comprehensive program is a wise investment. The second half of this paper lists 21 other forms of public participation, giving a description of each form, its purpose, and brief comments on its advantages

  17. (Radio)active participation

    CERN Multimedia

    Anaïs Schaeffer

    2014-01-01

    This year, for the first time, CERN hosted the Rencontres internationales lycéennes de la radioprotection: a three-day event in which some 200 students from 16 schools in France and elsewhere came together to discuss the topic of radiation protection and to deepen their understanding of the field.   Participants of the Rencontres internationales lycéennes de la radioprotection 2014. Each year since 2008, the Centre d’étude sur l’évaluation de la protection dans le domaine nucléaire français (CEPN, the French centre for studies of the evaluation of nuclear protection) and the Institut de radioprotection et de sûreté nucléaire français (IRSN, the French institute for radiation protection and nuclear safety), in partnership with various other bodies*, have been organising radiation protection workshops. Aimed at students between the ages of 15 and 18 from France and beyo...

  18. Participation for Development

    DEFF Research Database (Denmark)

    Dittrich, Yvonne; De La Harpe, Retha; Korpela, Mikko

    2014-01-01

    Information and Communication Technology (ICT) is more and more promoted as a driver and facilitator of economic growth and development in low and middle income countries. ICT for Development (ICT4D) though has mixed successes. Sustainability of solutions and usability respectively usefulness...... is rare. The workshop aims at bringing together the PD researchers working with under-privileged communities and attracting researchers from the ICT4D communities to the PD conference. The goal is to share experiences and start a discussion on how participation, ICT and development might relate....... for the intended beneficiaries have been reported as causes. Participatory approaches to development have been proposed to address these causes. Participatory Design (PD) seems like a perfect fit. However, at the Participatory Design Conferences, research that addresses PD in low and middle income countries...

  19. Participation beyond observation

    DEFF Research Database (Denmark)

    Chimirri, Niklas Alexander

    The past decades of child research have seen a rising number of practice-based studies which investigate the children’s perspectives on a multitude of everyday life phenomena. Researchers accompany children around and across contexts, become part of their sociomaterial interactions with peers......, however, the researchers typically uphold the notion that all they methodically engage in is participant observation. The paper argues that important aspects of children’s living and understanding may be lost when considering them mere objects of one’s visual and verbal research practices. First I delve...... into empirical material from my own participatory study in a daycare center in order to discuss how the child researcher ineluctably contributes to co-arranging the children’s lives under scrutiny and thereby the respective study’s insights. Then I draw on Svend Brinkmann & Lene Tanggaard’s critique...

  20. Use of osmolytes during solubilization and reconstitution of phosphate: sugar phosphate antiport from bacteria

    International Nuclear Information System (INIS)

    Ambudkar, S.V.; Sonna, L.A.; Maloney, P.C.

    1986-01-01

    Phosphate:2-deoxyglucose 6-phosphate (Pi:2DG6P) antiport was extracted from Streptococcus lactis or Staphylococcus aureus with 1.1% octylglucoside in the presence of 0.37% E. coli lipid and reconstituted by detergent dilution. Because previous work suggested inactivation at an early stage, the authors introduced protein stabilants during solubilization. When 20% glycerol was used, proteoliposomes showed a 20-fold increase in 32 Pi transport. This enhanced recovery required phospholipid plus glycerol, and was found only when both were added together with the detergent. Glycerol protection yielded proteoliposomes in which antiporters retained their normal kinetic properties, and Pi exchange by the streptococcal example gave a maximal rate (200-400 nmol/min per mg protein) and a turnover number (30-50/s) which suggested that inactivation had been avoided. Further study showed that 20% glycerol could be replaced by equally high concentrations of compounds classified as osmolytes polyols (erythritol, xylitol, sorbitol), sugars (glucose, trehalose) and certain amino acids (glycine, proline, but not valine). The authors suggest that osmolytes may be used to fully stabilize chemiosmotic transporters during reconstitution