WorldWideScience

Sample records for nitrate-nitric acid-water-tributyl phosphate

  1. Dietary Nitrate, Nitric Oxide, and Cardiovascular Health.

    Science.gov (United States)

    Bondonno, Catherine P; Croft, Kevin D; Hodgson, Jonathan M

    2016-09-09

    Emerging evidence strongly suggests that dietary nitrate, derived in the diet primarily from vegetables, could contribute to cardiovascular health via effects on nitric oxide (NO) status. NO plays an essential role in cardiovascular health. It is produced via the classical L-arginine-NO-synthase pathway and the recently discovered enterosalivary nitrate-nitrite-NO pathway. The discovery of this alternate pathway has highlighted dietary nitrate as a candidate for the cardioprotective effect of a diet rich in fruit and vegetables. Clinical trials with dietary nitrate have observed improvements in blood pressure, endothelial function, ischemia-reperfusion injury, arterial stiffness, platelet function, and exercise performance with a concomitant augmentation of markers of NO status. While these results are indicative of cardiovascular benefits with dietary nitrate intake, there is still a lingering concern about nitrate in relation to methemoglobinemia, cancer, and cardiovascular disease. It is the purpose of this review to present an overview of NO and its critical role in cardiovascular health; to detail the observed vascular benefits of dietary nitrate intake through effects on NO status as well as to discuss the controversy surrounding the possible toxic effects of nitrate.

  2. Sodium Phosphate

    Science.gov (United States)

    Sodium phosphate is used in adults 18 years of age or older to empty the colon (large intestine, bowel) ... view of the walls of the colon. Sodium phosphate is in a class of medications called saline ...

  3. Phosphate salts

    Science.gov (United States)

    ... levels that are too high, and for preventing kidney stones. They are also taken for treating osteomalacia (often ... But intravenous phosphate salts should not be used. Kidney stones (nephrolithiasis). Taking potassium phosphate by mouth might help ...

  4. Phosphate homeostasis and disorders.

    Science.gov (United States)

    Manghat, P; Sodi, R; Swaminathan, R

    2014-11-01

    Recent studies of inherited disorders of phosphate metabolism have shed new light on the understanding of phosphate metabolism. Phosphate has important functions in the body and several mechanisms have evolved to regulate phosphate balance including vitamin D, parathyroid hormone and phosphatonins such as fibroblast growth factor-23 (FGF23). Disorders of phosphate homeostasis leading to hypo- and hyperphosphataemia are common and have clinical and biochemical consequences. Notably, recent studies have linked hyperphosphataemia with an increased risk of cardiovascular disease. This review outlines the recent advances in the understanding of phosphate homeostasis and describes the causes, investigation and management of hypo- and hyperphosphataemia.

  5. Chloroquine Phosphate Oral

    Science.gov (United States)

    Chloroquine phosphate is in a class of drugs called antimalarials and amebicides. It is used to prevent and treat ... Chloroquine phosphate comes as a tablet to take by mouth. For prevention of malaria in adults, one dose is ...

  6. Glucose-6-phosphate dehydrogenase

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003671.htm Glucose-6-phosphate dehydrogenase test To use the sharing features on this page, please enable JavaScript. Glucose-6-phosphate dehydrogenase (G6PD) is a protein that helps red ...

  7. Why nature chose phosphates.

    Science.gov (United States)

    Westheimer, F H

    1987-03-06

    Phosphate esters and anhydrides dominate the living world but are seldom used as intermediates by organic chemists. Phosphoric acid is specially adapted for its role in nucleic acids because it can link two nucleotides and still ionize; the resulting negative charge serves both to stabilize the diesters against hydrolysis and to retain the molecules within a lipid membrane. A similar explanation for stability and retention also holds for phosphates that are intermediary metabolites and for phosphates that serve as energy sources. Phosphates with multiple negative charges can react by way of the monomeric metaphosphate ion PO3- as an intermediate. No other residue appears to fulfill the multiple roles of phosphate in biochemistry. Stable, negatively charged phosphates react under catalysis by enzymes; organic chemists, who can only rarely use enzymatic catalysis for their reactions, need more highly reactive intermediates than phosphates.

  8. Discussion about magnesium phosphating

    Directory of Open Access Journals (Sweden)

    P. Pokorny

    2016-07-01

    Full Text Available The paper describes results from recently published research focused on production of non-conventional magnesium phosphate Mg3(PO42・4H2O – bobierrite, or MgHPO4・3H2O – newberyite coating for both magnesium alloys and/or mild steel. This new kind of coating is categorized in the context of current state of phosphating technology and its potential advantages and crystal structure is discussed. At the same time, the suitable comparison techniques for magnesium phosphate coating and conventional zinc phosphate coating are discussed.

  9. Radioactivity of phosphate mineral products

    OpenAIRE

    Mitrović Branislava; Vitorović Gordana; Stojanović Mirjana; Vitorović Duško

    2011-01-01

    The phosphate industry is one of the biggest polluters of the environment with uranium. Different products are derived after processing phosphoric ore, such as mineral and phosphate fertilizers and phosphate mineral supplements (dicalcium-and monocalcium phosphate) for animal feeding. Phosphate mineral additives used in animal food may contain a high activity of uranium. Research in this study should provide an answer to the extent in which phosphate minera...

  10. Metal-phosphate binders

    Science.gov (United States)

    Howe, Beth Ann [Lewistown, IL; Chaps-Cabrera, Jesus Guadalupe [Coahuila, MX

    2009-05-12

    A metal-phosphate binder is provided. The binder may include an aqueous phosphoric acid solution, a metal-cation donor including a metal other than aluminum, an aluminum-cation donor, and a non-carbohydrate electron donor.

  11. Phosphate control in dialysis.

    Science.gov (United States)

    Cupisti, Adamasco; Gallieni, Maurizio; Rizzo, Maria Antonietta; Caria, Stefania; Meola, Mario; Bolasco, Piergiorgio

    2013-10-04

    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. Finally, boiling should be the preferred cooking procedure, because it induces food demineralization, including phosphate loss. The integrated approach outlined in this article should be actively adapted as a therapeutic alliance by clinicians, dieticians, and patients for an effective control of phosphate balance in dialysis patients.

  12. 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

  13. Phosphate Mines, Jordan

    Science.gov (United States)

    2008-01-01

    Jordan's leading industry and export commodities are phosphate and potash, ranked in the top three in the world. These are used to make fertilizer. The Jordan Phosphate Mines Company is the sole producer, having started operations in 1935. In addition to mining activities, the company produces phosphoric acid (for fertilizers, detergents, pharmaceuticals), diammonium phosphate (for fertilizer), sulphuric acid (many uses), and aluminum fluoride (a catalyst to make aluminum and magnesium). The image covers an area of 27.5 x 49.4 km, was acquired on September 17, 2005, and is located near 30.8 degrees north latitude, 36.1 degrees east longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  14. Research on Uncrystallized Phosphating Film

    Institute of Scientific and Technical Information of China (English)

    TANG En-jun; XING Ze-kuan

    2004-01-01

    This article excogitated a kind of uncrystallized phosphating film bears wearing capacity goodly by adding Ca2 + in normal phosphating solution. This technology is very useful to protect steel parts working in oil from abrasion.

  15. Glucose-6-phosphate dehydrogenase deficiency

    Science.gov (United States)

    ... medlineplus.gov/ency/article/000528.htm Glucose-6-phosphate dehydrogenase deficiency To use the sharing features on this page, please enable JavaScript. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a condition in which ...

  16. Practical application of phosphate treatment

    Energy Technology Data Exchange (ETDEWEB)

    Caravaggio, Mike [Integrated Chemistry Solutions Pte. Ltd., Singapore (Singapore)

    2011-05-15

    Phosphate treatment has been applied to subcritical fossil power boilers for well over half a century, as well as being used frequently in heat recovery steam generators. The use of this treatment has evolved over the decades, with the operating sodium to phosphate ratio being the defining factor for the evolution of the treatment. The evolving prescribed sodium to phosphate ratios have been based on the scientific research results and operating experience available at the time, and in the latest EPRI Guidelines issued in 2004 are set at a minimum sodium to phosphate ratio of 3:1, with provision to add up to 1 mg . L{sup -1} of additional free caustic. The ratio limitation has always been set in an effort to minimize the potential for corrosion caused by the potential misapplication of the treatment. Typically, the operating ranges for phosphate treatments are depicted on an x-y plot with the x-axis the phosphate concentration and the y-axis the corrected pH value based on the maximum sodium to phosphate ratio allowed for by the treatment. These operating range plots define the theoretical operating range of a phosphate treatment. This paper briefly discusses the origin of the current phosphate control limits in the EPRI Guidelines, discusses phosphate chemistry, outlines the limitations involved when applying a phosphate treatment and provides additional practical guidance for overcoming these limitations and minimizing the potential for corrosion induced by the incorrect application of a phosphate treatment. (orig.)

  17. Calcium Phosphate Biomaterials: An Update

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Current calcium phosphate (CaP) biomaterials for bone repair, substitution, augmentation and regeneration include hydroxyapatite ( HA ) from synthetic or biologic origin, beta-tricalcium phosphate ( β-TCP ) , biphasic calcium phosphate (BCP), and are available as granules, porous blocks, components of composites (CaP/polymer) cements, and as coatings on orthopedic and dental implants. Experimental calcium phosphate biomaterials include CO3- and F-substituted apatites, Mg-and Zn-substituted β-TCP, calcium phosphate glasses. This paper is a brief review of the different types of CaP biomaterials and their properties such as bioactivity, osteoconductivity, osteoinductivity.

  18. Biomediated continuous release phosphate fertilizer

    Science.gov (United States)

    Goldstein, Alan H.; Rogers, Robert D.

    1999-01-01

    A composition is disclosed for providing phosphate fertilizer to the root zone of plants. The composition comprises a microorganism capable of producing and secreting a solubilization agent, a carbon source for providing raw material for the microorganism to convert into the solubilization agent, and rock phosphate ore for providing a source of insoluble phosphate that is solubilized by the solubilization agent and released as soluble phosphate. The composition is provided in a physical form, such as a granule, that retains the microorganism, carbon source, and rock phosphate ore, but permits water and soluble phosphate to diffuse into the soil. A method of using the composition for providing phosphate fertilizer to plants is also disclosed.

  19. Hazards Analysis of Holston Ammonium Nitrate/Nitric Acid Storage and Transfer System

    Science.gov (United States)

    1974-07-01

    response of AN/NA matc-ial tested at the specific environ- mental conditions found in the process. Procese riska are determined and are provided to HRC m...tests were performed on the AN and AN/NA materials as part of the recently completed D-Buildiug analysis.(8) It was found that neither the AN nor...for the most part , operation of the process pumps where extreme in-process energies are capable of being generated. Under these coitditions, the

  20. Pyridoxal phosphate-dependent neonatal epileptic encephalopathy.

    Science.gov (United States)

    Bagci, S; Zschocke, J; Hoffmann, G F; Bast, T; Klepper, J; Müller, A; Heep, A; Bartmann, P; Franz, A R

    2008-03-01

    Pyridox(am)ine-5'-phosphate oxidase converts pyridoxine phosphate and pyridoxamine phosphate to pyridoxal phosphate, a cofactor in many metabolic reactions, including neurotransmitter synthesis. A family with a mutation in the pyridox(am)ine-5'-phosphate oxidase gene presenting with neonatal seizures unresponsive to pyridoxine and anticonvulsant treatment but responsive to pyridoxal phosphate is described. Pyridoxal phosphate should be considered in neonatal epileptic encephalopathy unresponsive to pyridoxine.

  1. Pyridoxal phosphate-dependent neonatal epileptic encephalopathy

    OpenAIRE

    2009-01-01

    Pyridox(am)ine-5′-phosphate oxidase converts pyridoxine phosphate and pyridoxamine phosphate to pyridoxal phosphate, a cofactor in many metabolic reactions, including neurotransmitter synthesis. A family with a mutation in the pyridox(am)ine-5′-phosphate oxidase gene presenting with neonatal seizures unresponsive to pyridoxine and anticonvulsant treatment but responsive to pyridoxal phosphate is described. Pyridoxal phosphate should be considered in neonatal epileptic encephalopathy unrespons...

  2. 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-cr...

  3. Light weight phosphate cements

    Science.gov (United States)

    Wagh, Arun S.; Natarajan, Ramkumar,; Kahn, David

    2010-03-09

    A sealant having a specific gravity in the range of from about 0.7 to about 1.6 for heavy oil and/or coal bed methane fields is disclosed. The sealant has a binder including an oxide or hydroxide of Al or of Fe and a phosphoric acid solution. The binder may have MgO or an oxide of Fe and/or an acid phosphate. The binder is present from about 20 to about 50% by weight of the sealant with a lightweight additive present in the range of from about 1 to about 10% by weight of said sealant, a filler, and water sufficient to provide chemically bound water present in the range of from about 9 to about 36% by weight of the sealant when set. A porous ceramic is also disclosed.

  4. Crystallo-chemical analyses of calcium phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Sakae, Toshiro; Hayakawa, Tohru; Maruyama, Fumiaki; Nemoto, Kimiya; Kozawa, Yukishige [Nihon Univ., Matsudo, Chiba (Japan). School of Dentistry

    1997-12-01

    Several analytical techniques, methodology and their practical data processing were briefly described to investigate the crystallographic properties of calcium phosphates which are encountered in the field of dental sciences. The applied analytical techniques were X-ray fluorescence spectrometry (XFS), energy dispersive spectrometry (EDS), Fourier transform infrared spectrometry (FT-IR) and X-ray diffraction (XRD). The used materials were tetracalcium phosphate, hydroxyapatite, fluorapatite, {alpha}-tricalcium phosphate, {beta}-tricalcium phosphate, octacalcium phosphate, monetite, brushite and monocalcium phosphate monohydrate. (author)

  5. Triphenyl phosphate allergy from spectacle frames

    DEFF Research Database (Denmark)

    Carlsen, Lars; Andersen, Klaus 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...... triphenyl phosphate allergy in our patient....

  6. 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)

  7. 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...

  8. Recent advances in phosphate biosensors.

    Science.gov (United States)

    Upadhyay, Lata Sheo Bachan; Verma, Nishant

    2015-07-01

    A number of biosensors have been developed for phosphate analysis particularly, concerning its negative impact within the environmental and biological systems. Enzymatic biosensors comprising either a single or multiple enzymatic system have been extensively used for the direct and indirect analysis of phosphate ions. Furthermore, some non-enzymatic biosensors, such as affinity-based biosensors, provide an alternative analytical approach with a higher selectivity. This article reviews the recent advances in the field of biosensor developed for phosphate estimation in clinical and environmental samples, concerning the techniques involved, and the sensitivity toward phosphate ions. The biosensors have been classified and discussed on the basis of the number of enzymes used to develop the analytical system, and a comparative analysis has been performed.

  9. 21 CFR 573.320 - Diammonium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Diammonium phosphate. 573.320 Section 573.320 Food... Additive Listing § 573.320 Diammonium phosphate. The food additive diammonium phosphate may be safely used... crude protein from diammonium phosphate, adequate directions for use and a prominent statement,...

  10. 21 CFR 184.1434 - Magnesium phosphate.

    Science.gov (United States)

    2010-04-01

    ... solution of magnesite with phosphoric acid. (b) Magnesium phosphate, dibasic, meets the specifications of... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium phosphate. 184.1434 Section 184.1434 Food... Specific Substances Affirmed as GRAS § 184.1434 Magnesium phosphate. (a) Magnesium phosphate includes...

  11. Formation of phosphatidylinositol 3-phosphate by isomerization from phosphatidylinositol 4-phosphate.

    OpenAIRE

    Walsh, J P; Caldwell, K K; Majerus, P W

    1991-01-01

    We have synthesized phosphatidylinositol 3-phosphate from phosphatidylinositol 4-phosphate by using diisopropylcarbodiimide to promote migration of the 4-phosphate via a cyclic phosphodiester intermediate. The product was isolated by a thin-layer chromatographic method that depends on the ability of phosphatidylinositol 4-phosphate, but not phosphatidylinositol 3-phosphate, to form complexes with boric acid. The final yield of the procedure was 8% phosphatidylinositol 3-phosphate, which was a...

  12. [Phosphate metabolism and iron deficiency].

    Science.gov (United States)

    Yokoyama, Keitaro

    2016-02-01

    Autosomal dominant hypophosphatemic rickets(ADHR)is caused by gain-of-function mutations in FGF23 that prevent its proteolytic cleavage. Fibroblast growth factor 23(FGF23)is a hormone that inhibits renal phosphate reabsorption and 1,25-dihydroxyvitamin D biosynthesis. Low iron status plays a role in the pathophysiology of ADHR. Iron deficiency is an environmental trigger that stimulates FGF23 expression and hypophosphatemia in ADHR. It was reported that FGF23 elevation in patients with CKD, who are often iron deficient. In patients with nondialysis-dependent CKD, treatment with ferric citrate hydrate resulted in significant reductions in serum phosphate and FGF23.

  13. Photorelease of phosphates: Mild methods for protecting phosphate derivatives

    Directory of Open Access Journals (Sweden)

    Sanjeewa N. Senadheera

    2014-08-01

    Full Text Available We have developed a new photoremovable protecting group for caging phosphates in the near UV. Diethyl 2-(4-hydroxy-1-naphthyl-2-oxoethyl phosphate (14a quantitatively releases diethyl phosphate upon irradiation in aq MeOH or aq MeCN at 350 nm, with quantum efficiencies ranging from 0.021 to 0.067 depending on the solvent composition. The deprotection reactions originate from the triplet excited state, are robust under ambient conditions and can be carried on to 100% conversion. Similar results were found with diethyl 2-(4-methoxy-1-naphthyl-2-oxoethyl phosphate (14b, although it was significantly less efficient compared with 14a. A key step in the deprotection reaction in aq MeOH is considered to be a Favorskii rearrangement of the naphthyl ketone motif of 14a,b to naphthylacetate esters 25 and 26. Disruption of the ketone-naphthyl ring conjugation significantly shifts the photoproduct absorption away from the effective incident wavelength for decaging of 14, driving the reaction to completion. The Favorskii rearrangement does not occur in aqueous acetonitrile although diethyl phosphate is released. Other substitution patterns on the naphthyl or quinolin-5-yl core, such as the 2,6-naphthyl 10 or 8-benzyloxyquinolin-5-yl 24 platforms, also do not rearrange by aryl migration upon photolysis and, therefore, do not proceed to completion. The 2,6-naphthyl ketone platform instead remains intact whereas the quinolin-5-yl ketone fragments to a much more complex, highly absorbing reaction mixture that competes for the incident light.

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

    Institute of Scientific and Technical Information of China (English)

    XU Ren-kou; ZHU Yong-guan; David Chittleborough

    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 Iow-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 not correlated with PKa. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearrly. 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.

  15. Phosphate Recognition in Structural Biology

    NARCIS (Netherlands)

    Hirsch, Anna K.H.; Fischer, Felix R.; Diederich, François

    2007-01-01

    Drug-discovery research in the past decade has seen an increased selection of targets with phosphate recognition sites, such as protein kinases and phosphatases, in the past decade. This review attempts, with the help of database-mining tools, to give an overview of the most important principles in

  16. Sintering of calcium phosphate bioceramics.

    Science.gov (United States)

    Champion, E

    2013-04-01

    Calcium phosphate ceramics have become of prime importance for biological applications in the field of bone tissue engineering. This paper reviews the sintering behaviour of these bioceramics. Conventional pressureless sintering of hydroxyapatite, Ca10(PO4)6(OH)2, a reference compound, has been extensively studied. Its physico-chemistry is detailed. It can be seen as a competition between two thermally activated phenomena that proceed by solid-state diffusion of matter: densification and grain growth. Usually, the objective is to promote the first and prevent the second. Literature data are analysed from sintering maps (i.e. grain growth vs. densification). Sintering trajectories of hydroxyapatite produced by conventional pressureless sintering and non-conventional techniques, including two-step sintering, liquid phase sintering, hot pressing, hot isostatic pressing, ultrahigh pressure, microwave and spark plasma sintering, are presented. Whatever the sintering technique may be, grain growth occurs mainly during the last step of sintering, when the relative bulk density reaches 95% of the maximum value. Though often considered very advantageous, most assisted sintering techniques do not appear very superior to conventional pressureless sintering. Sintering of tricalcium phosphate or biphasic calcium phosphates is also discussed. The chemical composition of calcium phosphate influences the behaviour. Similarly, ionic substitutions in hydroxyapatite or in tricalcium phosphate create lattice defects that modify the sintering rate. Depending on their nature, they can either accelerate or slow down the sintering rate. The thermal stability of compounds at the sintering temperature must also be taken into account. Controlled atmospheres may be required to prevent thermal decomposition, and flash sintering techniques, which allow consolidation at low temperature, can be helpful.

  17. Phosphate based oil well cements

    Science.gov (United States)

    Natarajan, Ramkumar

    The main application of the cement in an oil well is to stabilize the steel casing in the borehole and protect it from corrosion. The cement is pumped through the borehole and is pushed upwards through the annulus between the casing and the formation. The cement will be exposed to temperature and pressure gradients of the borehole. Modified Portland cement that is being used presently has several shortcomings for borehole sealant. The setting of the Portland cement in permafrost regions is poor because the water in it will freeze even before the cement sets and because of high porosity and calcium oxide, a major ingredient it gets easily affected by the down hole gases such as carbon dioxide. The concept of phosphate bonded cements was born out of considerable work at Argonne National Laboratory (ANL) on their use in stabilization of radioactive and hazardous wastes. Novel cements were synthesized by an acid base reaction between a metal oxide and acid phosphate solution. The major objective of this research is to develop phosphate based oil well cements. We have used thermodynamics along with solution chemistry principles to select calcined magnesium oxide as candidate metal oxide for temperatures up to 200°F (93.3°C) and alumina for temperatures greater than 200°F (93.3°C). Solution chemistry helped us in selecting mono potassium phosphate as the acid component for temperatures less than 200°F (93.3°C) and phosphoric acid solution greater than 200°F (93.3°C). These phosphate cements have performance superior to common Portland well cements in providing suitable thickening time, better mechanical and physical properties.

  18. 21 CFR 184.1301 - Ferric phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ferric phosphate. 184.1301 Section 184.1301 Food... Specific Substances Affirmed as GRAS § 184.1301 Ferric phosphate. (a) Ferric phosphate (ferric orthophosphate, iron (III) phosphate, FePO4·xH2O, CAS Reg. No. 10045-86-0) is an odorless, yellowish-white...

  19. 21 CFR 182.1778 - Sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium phosphate. 182.1778 Section 182.1778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic)....

  20. 21 CFR 582.5301 - Ferric phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ferric phosphate. 582.5301 Section 582.5301 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5301 Ferric phosphate. (a) Product. Ferric phosphate. (b) Conditions of use....

  1. 21 CFR 182.8778 - Sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium phosphate. 182.8778 Section 182.8778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  2. 21 CFR 582.6778 - Sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium phosphate. 582.6778 Section 582.6778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use....

  3. 21 CFR 582.1778 - Sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium phosphate. 582.1778 Section 582.1778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic)....

  4. 21 CFR 582.5778 - Sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium phosphate. 582.5778 Section 582.5778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic)....

  5. 21 CFR 182.6778 - Sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium phosphate. 182.6778 Section 182.6778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  6. 21 CFR 582.5217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium phosphate. 582.5217 Section 582.5217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5217 Calcium phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic)....

  7. 21 CFR 182.8217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium phosphate. 182.8217 Section 182.8217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  8. 40 CFR 721.5995 - Polyalkyl phosphate.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyalkyl phosphate. 721.5995 Section... Substances § 721.5995 Polyalkyl phosphate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polyalkyl phosphate (PMN P-95-1772)...

  9. 21 CFR 582.6285 - Dipotassium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Dipotassium phosphate. 582.6285 Section 582.6285 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Dipotassium phosphate. (a) Product. Dipotassium phosphate. (b) Conditions of use. This substance is...

  10. 21 CFR 582.1141 - Ammonium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  11. 21 CFR 582.1217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium phosphate. 582.1217 Section 582.1217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1217 Calcium phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic)....

  12. 21 CFR 582.6290 - Disodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Disodium phosphate. 582.6290 Section 582.6290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Disodium phosphate. (a) Product. Disodium phosphate. (b) Conditions of use. This substance is...

  13. 21 CFR 182.1217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium phosphate. 182.1217 Section 182.1217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1217 Calcium phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic)....

  14. 21 CFR 582.5434 - Magnesium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium phosphate. 582.5434 Section 582.5434 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5434 Magnesium phosphate. (a) Product. Magnesium phosphate (di- and tribasic)....

  15. 21 CFR 182.6285 - Dipotassium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Dipotassium phosphate. 182.6285 Section 182.6285 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Dipotassium phosphate. (a) Product. Dipotassium phosphate. (b) Conditions of use. This substance is...

  16. 21 CFR 182.6290 - Disodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Disodium phosphate. 182.6290 Section 182.6290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... phosphate. (a) Product. Disodium phosphate. (b) Conditions of use. This substance is generally recognized...

  17. 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 .... phosphate in gradient soils, there might be changes in ..... resistance properties, fatty acid profiling and nucleic acid.

  18. Calcium phosphate cements: study of the beta-tricalcium phosphate--monocalcium phosphate system.

    Science.gov (United States)

    Mirtchi, A A; Lemaitre, J; Terao, N

    1989-09-01

    The possibility of making cements based on beta-tricalcium phosphate (beta-TCP), a promising bone graft material, was investigated. Upon admixture with water, beta-TCP/monocalcium phosphate monohydrate (MCPM) mixtures were found to set and harden like conventional hydraulic cements. Beta-TCP powders with larger particle size, obtained by sintering at higher temperatures, increased the ultimate strength of the cement. Results show that setting occurs after dissolution of MCPM, as a result of the precipitation of dicalcium phosphate dihydrate (DCPD) in the paste. The ultimate tensile strength of the hardened cement is proportional to the amount of DCPD formed. Upon ageing above 40 degrees C, DCPD transforms progressively into anhydrous dicalcium phosphate (DCP), thereby decreasing the strength. Ageing of the pastes in 100% r.h. results in a decay of the mechanical properties. This can be ascribed to an intergranular dissolution of the beta-TCP aggregates as a result of the pH lowering brought about by the MCPM to DCPD conversion.

  19. [Phosphate sensing and parathyroid gland].

    Science.gov (United States)

    Mizobuchi, Masahide; Suzuki, Taihei

    2012-10-01

    In the latter 1990s, phosphate, as well as calcium, has been shown to have a direct action on parathyroid function. Since then although many researchers have tried to detect the phosphate sensor in parathyroid gland, none has found it yet. In 2000s, the importance of FGF23 was revealed in patients with autosomal dominant hypophosphatemic rickets and then investigating the role of FGF23 in mineral metabolism has spread. FGF23 target organs comprise those that express coreceptor Klotho, such as kidney and parathyroid glands. While associations of calcium sensing receptor or vitamin D receptor with parathyroid function have been mainly investigated for parathyroid dysfunction, many efforts recently have made to study the effects of FGF23 on parathyroid glands.

  20. Calcium phosphate polymer hybrid materials

    OpenAIRE

    2011-01-01

    Calcium phosphate (CaP) is of strong interest to the medical field because of its potential for bone repair, gene transfection, etc.1-3 Nowadays, the majority of the commercially available materials are fabricated via “classical” materials science approaches, i.e. via high temperature or high pressure approaches, from rather poorly defined slurries, or from organic solvents.3,4 Precipitation of inorganics with (polymeric) additives from aqueous solution on the other hand enables the synthesis...

  1. Phosphate: are we squandering a scarce commodity?

    Science.gov (United States)

    Ferro, Charles J; Ritz, Eberhard; Townend, Jonathan N

    2015-02-01

    Phosphorus is an essential element for life but is a rare element in the universe. On Earth, it occurs mostly in the form of phosphates that are widespread but predominantly at very low concentration. This relative rarity has resulted in a survival advantage, in evolutionary terms, to organisms that conserve phosphate. When phosphate is made available in excess it becomes a cause for disease, perhaps best recognized as a potential cardiovascular and renal risk factor. As a reaction to the emerging public health issue caused by phosphate additives to food items, there have been calls for a public education programme and regulation to bring about a reduction of phosphate additives to food. During the Paleoproterzoic era, an increase in the bioavailability of phosphate is thought to have contributed significantly to the oxygenation of our atmosphere and a dramatic increase in the evolution of new species. Currently, phosphate is used poorly and often wasted with phosphate fertilizers washing this scarce commodity into water bodies causing eutrophication and algal blooms. Ironically, this is leading to the extinction of hundreds of species. The unchecked exploitation of phosphate rock, which is an increasingly rare natural resource, and our dependence on it for agriculture may lead to a strange situation in which phosphate might become a commodity to be fought over whilst at the same time, health and environmental experts are likely to recommend reductions in its use.

  2. Can Phosphate Salts Recovered from Manure Replace Conventional Phosphate Fertilizer?

    Directory of Open Access Journals (Sweden)

    Andrea Ehmann

    2017-01-01

    Full Text Available Pig farming produces more manure than can reasonably be spread onto surrounding fields, particularly in regions with high livestock densities and limited land availability. Nutrient recycling offers an attractive solution for dealing with manure excesses and is one main objective of the European commission-funded project “BioEcoSIM”. Phosphate salts (“P-Salt” were recovered from the separated liquid manure fraction. The solid fraction was dried and carbonized to biochar. This study compared the fertilizing performance of P-Salt and conventional phosphate fertilizer and determined whether additional biochar application further increased biomass yields. The fertilizers and biochar were tested in pot experiments with spring barley and faba beans using two nutrient-poor soils. The crops were fertilized with P-Salt at three levels and biochar in two concentrations. Biomass yield was determined after six weeks. Plant and soil samples were analysed for nitrogen, phosphorus and potassium contents. The P-Salt had similar or even better effects than mineral fertilizer on growth in both crops and soils. Slow release of nutrients can prevent leaching, rendering P-Salt a particularly suitable fertilizer for light sandy soils. Biochar can enhance its fertilizing effect, but the underlying mechanisms need further investigation. These novel products are concluded to be promising candidates for efficient fertilization strategies.

  3. Tetracalcium phosphate: Synthesis, properties and biomedical applications.

    Science.gov (United States)

    Moseke, C; Gbureck, U

    2010-10-01

    Monoclinic tetracalcium phosphate (TTCP, Ca(4)(PO(4))(2)O), also known by the mineral name hilgenstockite, is formed in the (CaO-P(2)O(5)) system at temperatures>1300 degrees C. TTCP is the only calcium phosphate with a Ca/P ratio greater than hydroxyapatite (HA). It appears as a by-product in plasma-sprayed HA coatings and shows moderate reactivity and concurrent solubility when combined with acidic calcium phosphates such as dicalcium phosphate anhydrous (DCPA, monetite) or dicalcium phosphate dihydrate (DCPD, brushite). Therefore it is widely used in self-setting calcium phosphate bone cements, which form HA under physiological conditions. This paper aims to review the synthesis and properties of TTCP in biomaterials applications such as cements, sintered ceramics and coatings on implant metals.

  4. Insight into biological phosphate recovery from sewage.

    Science.gov (United States)

    Ye, Yuanyao; Ngo, Huu Hao; Guo, Wenshan; Liu, Yiwen; Zhang, Xinbo; Guo, Jianbo; Ni, Bing-Jie; Chang, Soon Woong; Nguyen, Dinh Duc

    2016-10-01

    The world's increasing population means that more food production is required. A more sustainable supply of fertilizers mainly consisting of phosphate is needed. Due to the rising consumption of scarce resources and limited natural supply of phosphate, the recovery of phosphate and their re-use has potentially high market value. Sewage has high potential to recover a large amount of phosphate in a circular economy approach. This paper focuses on utilization of biological process integrated with various subsequent processes to concentrate and recycle phosphate which are derived from liquid and sludge phases. The phosphate accumulation and recovery are discussed in terms of mechanism and governing parameters, recovery efficiency, application at plant-scale and economy.

  5. 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.

  6. Matrix Extracellular Phosphoglycoprotein Inhibits Phosphate Transport

    OpenAIRE

    Marks, J; Churchill, L J; Debnam, E. S.; Unwin, R J

    2008-01-01

    The role of putative humoral factors, known as phosphatonins, in phosphate homeostasis and the relationship between phosphate handling by the kidney and gastrointestinal tract are incompletely understood. Matrix extracellular phosphoglycoprotein (MEPE), one of several candidate phosphatonins, promotes phosphaturia, but whether it also affects intestinal phosphate absorption is unknown. Here, using the in situ intestinal loop technique, we demonstrated that short-term infusion of MEPE inhibits...

  7. Preparation of porous lanthanum phosphate with templates

    Energy Technology Data Exchange (ETDEWEB)

    Onoda, Hiroaki, E-mail: onoda@kpu.ac.jp [Department of Informatics and Environmental Sciences, Faculty of Life and Environmental Sciences, Kyoto Prefectural University, 1-5, Shimogamo Nakaragi-cyo, Sakyo-ku, Kyoto 606-8522 (Japan); Ishima, Yuya [Department of Applied Chemistry, Faculty of Life Sciences, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Takenaka, Atsushi [Department of Materials Science, Yonago National College of Technology, 4448, Hikona-cho, Yonago, Tottori 683-8502 (Japan); Tanaka, Isao [Department of Materials Science and Engineering, Faculty of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)

    2009-08-05

    Malonic acid, propionic acid, glycine, n-butylamine, and urea were added to the preparation of lanthanum phosphate from lanthanum nitrate and phosphoric acid solutions. All additives were taken into lanthanum phosphate particles. The additives that have a basic site were easy to contain in precipitates. The addition of templates improved the specific surface area of lanthanum phosphate. The amount of pore, with radius smaller than 4 nm, increased with the addition of templates. The remained additives had influence on the acidic properties of lanthanum phosphate.

  8. Mineral induced formation of sugar phosphates

    Science.gov (United States)

    Pitsch, S.; Eschenmoser, A.; Gedulin, B.; Hui, S.; Arrhenius, G.

    1995-01-01

    Glycolaldehyde phosphate, sorbed from highly dilute, weakly alkaline solution into the interlayer of common expanding sheet structure metal hydroxide minerals, condenses extensively to racemic aldotetrose-2, 4-diphophates, and aldohexose-2, 4, 6-triphosphates. The reaction proceeds mainly through racemic erythrose-2, 4-phosphate, and terminates with a large fraction of racemic altrose-2, 4, 6-phosphate. In the absence of an inductive mineral phase, no detectable homogeneous reaction takes place in the concentration- and pH range used. The reactant glycolaldehyde phosphate is practically completely sorbed within an hour from solutions with concentrations as low as 50 micron; the half-time for conversion to hexose phosphates is of the order of two days at room temperature and pH 9.5. Total production of sugar phosphates in the mineral interlayer is largely independent of the glycolaldehyde phosphate concentration in the external solution, but is determined by the total amount of GAP offered for sorption up to the capacity of the mineral. In the presence of equimolar amounts of rac-glyceraldehyde-2-phosphate, but under otherwise similar conditions, aldopentose-2, 4, -diphosphates also form, but only as a small fraction of the hexose-2, 4, 6-phosphates.

  9. Study of Viability of Phosphate Solubilizing Bacteria in Phosphate granules

    Directory of Open Access Journals (Sweden)

    hajar rajabi

    2017-06-01

    Full Text Available Introduction: sustainable development and the environment are interconnected. Sustainable agriculture is continuous utilization of a farm with respect to various aspects of environmental conditions by using fewer inputs (other than Bio-fertilizers. Phosphorus is one of the essential elements for the plants. Management of soil is possible by using biological fertilizers pillar of sustainable agriculture and providing some of the phosphorus needed by plants via bio-fertilizers. Phosphorus deficiency is extremely effective on the plant growth and productivity. The application of phosphorus fertilizers is expensive and dangerous. In addition, phosphorus in the soilmay become insoluble and will be unavailable to the plants. Studies showed that phosphate solubilizing bacteria in the soil rhizosphere are active and by root exudates solve insoluble phosphates such as tricalcium phosphate, and form absorbable P for plant. Consequently, the use of microbial fertilizers could reduce excessive use of chemical fertilizers and lead to decrease their harmful effects and protect the environment and conservation of available resources. The biological phosphate fertilizer industry uses sugar beet molasses as a binder and drying granules at high temperatures. Therefore, it is important to evaluate the durability of the bacteria in molasses at high temperature. Materials and Methods: This study was designed as completely randomized design in a factorial arrangement.10 isolates were selected and the ratios of 50%, 25%, 15% and 10% of the apatite, organic matter, sulfur and soluble granule (ratio 1: 1 and 2: 1 bacteria and molasses, respectively, for each isolate was prepared. The final product was dried at 28 and 40 °C and remained for 4 months and population counted at first day and 10, 20, 30, 60, 90 and 120 days after the preparing. The population was counted by the serial dilution technique and cultured at Sperber media. Results and Discussion:Comparing the

  10. Drug-pyridoxal phosphate interactions.

    Science.gov (United States)

    Ebadi, M; Gessert, C F; Al-Sayegh, A

    1982-01-01

    phosphate. Some interesting relationships are pointed out between vitamin B6, picolinic acid, and zinc. It is postulated that the intestinal absorption of zinc is facilitated by picolinic acid, a metabolite of tryptophan. The derivation of picolinic acid from tryptophan depends on the action of the enzyme kynureninase, which is dependent on pyridoxal phosphate; therefore, the adequate absorption of zinc is indirectly dependent on an adequate supply of vitamin B6. The formation of pyridoxal phosphate, on the other hand, appears to be indirectly dependent on Zn2++ which activates pyridoxal kinase.(ABSTRACT TRUNCATED AT 400 WORDS)

  11. 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 tre

  12. 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 forma

  13. Stable Development of Phosphate Fertilizer Sector

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ The rapid growth of China's economy in recent years gave rise to a sound external environment for the development of the phosphate fertilizer industry. With quite a few state agricultural incentives, the initiative of farmers in grain production is much higher, and consumption of phosphate fertilizers has increased constantly.

  14. Electrochemical phosphate recovery from nanofiltration concentrates

    NARCIS (Netherlands)

    Kappel, C.; Yasadi, K.; Temmink, B.G.; Metz, S.J.; Kemperman, A.J.B.; Nijmeijer, K.; Zwijnenburg, A.; Witkamp, G.J.; Rijnaarts, H.

    2013-01-01

    The high total phosphorus content of raw domestic wastewater with its significant eutrophication potential offers an excellent possibility for phosphate recovery. Continuous recirculation of NF concentrate to an MBR and simultaneous phosphate recovery from the NF concentrate can be applied to produc

  15. 21 CFR 520.823 - Erythromycin phosphate.

    Science.gov (United States)

    2010-04-01

    .... (a) Specifications. Erythromycin phosphate is the phosphate salt of the antibiotic substance produced by the growth of Streptomyces erythreus or the same antibiotic substance produced by any other means... chickens—(i) Amount. 0.500 gram per gallon. (ii) Indications for use. As an aid in the control of...

  16. Adsorption of Phosphate on Variable Charge Soils

    Institute of Scientific and Technical Information of China (English)

    HUGUO-SONG; ZHUZU-XIANG; 等

    1992-01-01

    The study about the adsorption of phosphate on four variable charge soils and some minerals revealed that two stage adsorption appeared in the adsorption isothems of phosphate on 4 soils and there was a maximum adsorption on Al-oxide-typed surfaces between pH 3.5 to pH 5.5 as suspension pH changed from 2 to 9,but the adsorption amount of phosphate decreased continually as pH rose on Fe-oxide typed surfaces.The adsorption amount of phosphate and the maximum phosphate adsorption pH decreased in the order of yellow-red soil> lateritic red soil> red soil> paddy soil,which was coincided with the content order of amorphous Al oxide.The removement of organic matter and Fe oxide made the maximum phosphate adsorption pH rise from 4.0 to 5.0 and 4.5,respectively.The desorption curves with pH of four soils showed that phosphate desorbed least at pH 5.Generally the desorption was contrary to the adsorption with pH changing.There was a good accordance between adsorption or desorption and the concentration of Al in the suspension.The possible mechanisms of phosphate adsorption are discussed.

  17. Phosphate Biomineralization of Cambrian Microorganisms

    Science.gov (United States)

    McKay, David S.; Rozanov, Alexei Yu.; Hoover, Richard B.; Westall, Frances

    1998-01-01

    As part of a long term study of biological markers (biomarkers), we are documenting a variety of features which reflect the previous presence of living organisms. As we study meteorites and samples returned from Mars, our main clue to recognizing possible microbial material may be the presence of biomarkers rather than the organisms themselves. One class of biomarkers consists of biominerals which have either been precipitated directly by microorganisms, or whose precipitation has been influenced by the organisms. Such microbe-mediated mineral formation may include important clues to the size, shape, and environment of the microorganisms. The process of fossilization or mineralization can cause major changes in morphologies and textures of the original organisms. The study of fossilized terrestrial organisms can help provide insight into the interpretation of mineral biomarkers. This paper describes the results of investigations of microfossils in Cambrian phosphate-rich rocks (phosphorites) that were found in Khubsugul, Northern Mongolia.

  18. Genetics Home Reference: pyridoxal 5'-phosphate-dependent epilepsy

    Science.gov (United States)

    ... 5'-phosphate-dependent epilepsy pyridoxal 5'-phosphate-dependent epilepsy Enable Javascript to view the expand/collapse boxes. ... All Close All Description Pyridoxal 5'-phosphate-dependent epilepsy is a condition that involves seizures beginning soon ...

  19. Hydrolysis of dicalcium phosphate dihydrate to hydroxyapatite.

    Science.gov (United States)

    Fulmer, M T; Brown, P W

    1998-04-01

    Dicalcium phosphate dihydrate (DCPD) was hydrolysed in water and in 1 M Na2HPO4 solution at temperatures from 25-60 degrees C. Hydrolysis was incomplete in water. At 25 degrees C, DCPD partially hydrolysed to hydroxyapatite (HAp). Formation of HAp is indicative of incongruent DCPD dissolution. At the higher temperatures, hydrolysis to HAp was more extensive and was accompanied by the formation of anhydrous dicalcium phosphate (DCP). Both of these processes are endothermic. When hydrolysis was carried out in 1 M Na2HPO4 solution, heat absorption was greater at any given temperature than for hydrolysis in water. Complete hydrolysis to HAp occurred in this solution. The hydrolysis of DCPD to HAp in sodium phosphate solution was also endothermic. The complete conversion of DCPD to HAp in sodium phosphate solution would not be expected if the only effect of this solution was to cause DCPD dissolution to become congruent. Because of the buffering capacity of a dibasic sodium phosphate solution, DCPD hydrolysed completely to HAp. Complete conversion to HAp was accompanied by the conversion of dibasic sodium phosphate to monobasic sodium phosphate. The formation of DCP was not observed indicating that the sodium phosphate solution precluded the DCPD-to-DCP dehydration reaction. In addition to affecting the extent of hydrolysis, reaction in the sodium phosphate solution also caused a morphological change in the HAp which formed. HAp formed by hydrolysis in water was needle-like to globular while that formed in the sodium phosphate solution exhibited a florette-like morphology.

  20. Dominant oceanic bacteria secure phosphate using a large extracellular buffer

    OpenAIRE

    M. V. Zubkov; Martin, A. P.; Hartmann, M.; Grob, C.; Scanlan, D.J.

    2015-01-01

    The ubiquitous SAR11 and Prochlorococcus bacteria manage to maintain a sufficient supply of phosphate in phosphate-poor surface waters of the North Atlantic subtropical gyre. Furthermore, it seems that their phosphate uptake may counter-intuitively be lower in more productive tropical waters, as if their cellular demand for phosphate decreases there. By flow sorting 33P-phosphate-pulsed 32P-phosphate-chased cells, we demonstrate that both Prochlorococcus and SAR11 cells exploit an extracellul...

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

    OpenAIRE

    Qurban Ali Panhwar; Shamshuddin Jusop; Umme Aminun Naher; Radziah Othman; Mohd Ismail Razi

    2013-01-01

    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 ...

  2. 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 Gq). 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, S1P2 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 S1P2 in promoting metastasis of cancer cells and which is dependent on the micro-environmental niche. Copyright © 2017. Published by Elsevier Ltd.

  3. Enzyme activity in dialkyl phosphate ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, M.F.; Dunn, J.; Li, L.-L.; Handley-Pendleton, J. M.; van der lelie, D.; Wishart, J. F.

    2011-12-01

    The activity of four metagenomic enzymes and an enzyme cloned from the straw mushroom, Volvariellavolvacea were studied in the following ionic liquids, 1,3-dimethylimidazolium dimethyl phosphate, [mmim][dmp], 1-ethyl-3-methylimidazolium dimethyl phosphate, [emim][dmp], 1-ethyl-3-methylimidazolium diethyl phosphate, [emim][dep] and 1-ethyl-3-methylimidazolium acetate, [emim][OAc]. Activity was determined by analyzing the hydrolysis of para-nitrobenzene carbohydrate derivatives. In general, the enzymes were most active in the dimethyl phosphate ionic liquids, followed by acetate. Generally speaking, activity decreased sharply for concentrations of [emim][dep] above 10% v/v, while the other ionic liquids showed less impact on activity up to 20% v/v.

  4. Enzyme activity in dialkyl phosphate ionic liquids.

    Science.gov (United States)

    Thomas, Marie F; Li, Luen-Luen; Handley-Pendleton, Jocelyn M; van der Lelie, Daniel; Dunn, John J; Wishart, James F

    2011-12-01

    The activity of four metagenomic enzymes and an enzyme cloned from the straw mushroom, Volvariella volvacea were studied in the following ionic liquids, 1,3-dimethylimidazolium dimethyl phosphate, [mmim][dmp], 1-ethyl-3-methylimidazolium dimethyl phosphate, [emim][dmp], 1-ethyl-3-methylimidazolium diethyl phosphate, [emim][dep] and 1-ethyl-3-methylimidazolium acetate, [emim][OAc]. Activity was determined by analyzing the hydrolysis of para-nitrobenzene carbohydrate derivatives. In general, the enzymes were most active in the dimethyl phosphate ionic liquids, followed by acetate. Generally speaking, activity decreased sharply for concentrations of [emim][dep] above 10% v/v, while the other ionic liquids showed less impact on activity up to 20% v/v.

  5. Synthesis of Caged Bicyclic Phosphate Derivatives

    Institute of Scientific and Technical Information of China (English)

    FANG Xiao-min; OU Yu-xiang; LUO Rui-bin; WANG Yong; LIAN Dan-jun; LI Xin

    2008-01-01

    Seven caged bicyclic phosphate compounds were synthesized by using 1-oxo-4-hydroxymethy1-2,6,7-trioxa-1-pho-sphabicyclo[2.2.2] octane (PEPA) as starting material. Within them were three PEPA derivatives containing single caged bicyclic phosphate structure(1a,2a,3a), another three PEPA deviratives containing two caged bicyclic phosphate structures(1b,2b,3b) and one devirative(1c) containing three caged bicyclic phosphate structures. Structures of the products were characterized by FTIR, 1H NMR, elemental analysis and TG analysis. The reaction conditions were also discussed. Thermal analysis showed they had high thermal stability and excellent char-forming ability. Besides, these compounds had pentaerythritol bone and flame retardant elements of phosphorus, bromine or nitrogen simultaneously in their molecules, endowed them with good fire retardancy, and made them can be used as intumescent flame retardant.

  6. Pyridoxal Phosphate vs Pyridoxine for Intractable Seizures

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2005-05-01

    Full Text Available The efficacy of pyridoxal phosphate (PLP compared to pyridoxine (PN in the control of idiopathic intractable epilepsy was studied in 94 children, aged 8 months to 15 years, at the National Taiwan University Hospital, Taipei, Taiwan.

  7. 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 ... all the sampling sites had phosphate level above the World Health Organization maximum contaminant ...

  8. 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...

  9. Physical Properties of Acidic Calcium Phosphate Cements

    OpenAIRE

    2014-01-01

    The gold standard for bone replacement today, autologous bone, suffers from several disadvantages, such as the increased risk of infection due to the need for two surgeries. Degradable synthetic materials with properties similar to bone, such as calcium phosphate cements, are a promising alternative. Calcium phosphate cements are suited for a limited amount of applications and improving their physical properties could extend their use into areas previously not considered possible. For example...

  10. An investigation of iron phosphate glasses

    Science.gov (United States)

    Fang, Xiangyu

    The effect of melting history on the iron redox equilibrium, structure, crystallization and properties of a binary iron phosphate glass with a 40Fe 2O3-60P2O5, mol%, batch composition were investigated. The structure and properties of single and mixed alkali iron phosphate glasses were also studied. Mossbauer, Raman and infrared spectroscopy were used to determine the changes in the concentration of iron ions and phosphate units in the structure. Differential thermal analysis, X-ray diffraction and thermogravimetric analysis were used to investigate crystallization. Density, molar volume, thermal expansion, dc electrical conductivity and dielectric constant and loss tangent were measured. The heat capacity and glass transition behavior of the glasses was also measured by the differential scanning calorimeter method. The effect of the melting temperature is stronger than the melting time on the concentration of Fe2+ ions in iron phosphate glasses. The pyrophosphate network in iron phosphate glasses and their general properties do not change either with melting temperature and time or with adding up to 20 mol% of single and mixed alkali oxides. The dissolution rate (in deionized water) of these glasses is generally very low (˜10-9 g/cm2/min) and nearly independent of the relative concentration of Fe 2+ or Fe3+ ions. The dissolution rate of the iron phosphate glasses containing 20 mol% of single or mixed alkali oxide can be comparable to that of window glass. There is no mixed alkali effect in the iron phosphate glasses. The crystallization tendency indicates that the glass structure becomes closer to that of crystalline Fe3(P2O 7)2 with increasing concentration of Fe2+ ions in the glass. The large fragility parameters indicates that the iron phosphate glasses belong in the category of the fragile glass-forming liquids.

  11. Isolation of phosphate-solubilizing fungus and its application in solubilization of rock phosphates.

    Science.gov (United States)

    Wu, Yingben; He, Yuelin; Yin, Hongmei; Chen, Wei; Wang, Zhen; Xu, Lijuan; Zhang, Aiqun

    2012-12-01

    Microorganisms have been obtained to improve the agronomic value of rock phosphates (RPs), but the phosphorus solubilizing rate by these approaches is very slow. It is important to explore a high-efficient phosphate-solubilizing approach with a kind of microorganisms. This study aimed to isolate a high-efficient level of phosphate-solubilizing fungus from rhizosphere soil samples phosphate mines (Liuyang County, Hunan province, China) and apply it in solubilization of RPs. The experiments were carried out by the conventional methodology for morphological and biochemical fungus characterization and the analysis of 18s rRNA sequence. Then the effects of time, temperature, initial pH, phosphorus (P) sources, RPs concentration, shaking speed and silver ion on the content of soluble P released by this isolate were investigated. The results showed this isolate was identified as Galactomyces geotrichum P14 (P14) in GeneBank and the maximum amount of soluble P was 1252.13 mg L(-1) within 40 h in a modified phosphate growth agar's medium (without agar) where contained tricalcium phosphate (TCP) as sole phosphate source. At the same time, it could release phosphate and solubilize various rock phosphates. The isolated fungus can convert RPs from insoluble form into plant available form and therefore it hold great potential for biofertilizers to enhance soil fertility and promote plant growth.

  12. Using phosphate supplementation to reverse hypophosphatemia and phosphate depletion in neurological disease and disturbance.

    Science.gov (United States)

    Håglin, Lena

    2016-06-01

    Hypophosphatemia (HP) with or without intracellular depletion of inorganic phosphate (Pi) and adenosine triphosphate has been associated with central and peripheral nervous system complications and can be observed in various diseases and conditions related to respiratory alkalosis, alcoholism (alcohol withdrawal), diabetic ketoacidosis, malnutrition, obesity, and parenteral and enteral nutrition. In addition, HP may explain serious muscular, neurological, and haematological disorders and may cause peripheral neuropathy with paresthesias and metabolic encephalopathy, resulting in confusion and seizures. The neuropathy may be improved quickly after proper phosphate replacement. Phosphate depletion has been corrected using potassium-phosphate infusion, a treatment that can restore consciousness. In severe ataxia and tetra paresis, complete recovery can occur after adequate replacement of phosphate. Patients with multiple risk factors, often with a chronic disease and severe HP that contribute to phosphate depletion, are at risk for neurologic alterations. To predict both risk and optimal phosphate replenishment requires assessing the nutritional status and risk for re-feeding hypophosphatemia. The strategy for correcting HP depends on the severity of the underlying disease and the goal for re-establishing a phosphate balance to limit the consequences of phosphate depletion.

  13. Capturing phosphates with iron enhanced sand filtration.

    Science.gov (United States)

    Erickson, Andrew J; Gulliver, John S; Weiss, Peter T

    2012-06-01

    Most treatment practices for urban runoff capture pollutants such as phosphorus by either settling or filtration while dissolved phosphorus, typically as phosphates, is untreated. Dissolved phosphorus, however, represents an average 45% of total phosphorus in stormwater runoff and can be more than 95%. In this study, a new stormwater treatment technology to capture phosphate, called the Minnesota Filter, is introduced. The filter comprises iron filings mixed with sand and is tested for phosphate removal from synthetic stormwater. Results indicate that sand mixed with 5% iron filings captures an average of 88% phosphate for at least 200 m of treated depth, which is significantly greater than a sand filter without iron filings. Neither incorporation of iron filings into a sand filter nor capture of phosphates onto iron filings in column experiments had a significant effect on the hydraulic conductivity of the filter at mixtures of 5% or less iron by weight. Field applications with up to 10.7% iron were operated over 1 year without detrimental effects upon hydraulic conductivity. A model is applied and fit to column studies to predict the field performance of iron-enhanced sand filters. The model predictions are verified through the predicted performance of the filters in removing phosphates in field applications. Practical applications of the technology, both existing and proposed, are presented so stormwater managers can begin implementation.

  14. The evolution of the marine phosphate reservoir.

    Science.gov (United States)

    Planavsky, Noah J; Rouxel, Olivier J; Bekker, Andrey; Lalonde, Stefan V; Konhauser, Kurt O; Reinhard, Christopher T; Lyons, Timothy W

    2010-10-28

    Phosphorus is a biolimiting nutrient that has an important role in regulating the burial of organic matter and the redox state of the ocean-atmosphere system. The ratio of phosphorus to iron in iron-oxide-rich sedimentary rocks can be used to track dissolved phosphate concentrations if the dissolved silica concentration of sea water is estimated. Here we present iron and phosphorus concentration ratios from distal hydrothermal sediments and iron formations through time to study the evolution of the marine phosphate reservoir. The data suggest that phosphate concentrations have been relatively constant over the Phanerozoic eon, the past 542 million years (Myr) of Earth's history. In contrast, phosphate concentrations seem to have been elevated in Precambrian oceans. Specifically, there is a peak in phosphorus-to-iron ratios in Neoproterozoic iron formations dating from ∼750 to ∼635 Myr ago, indicating unusually high dissolved phosphate concentrations in the aftermath of widespread, low-latitude 'snowball Earth' glaciations. An enhanced postglacial phosphate flux would have caused high rates of primary productivity and organic carbon burial and a transition to more oxidizing conditions in the ocean and atmosphere. The snowball Earth glaciations and Neoproterozoic oxidation are both suggested as triggers for the evolution and radiation of metazoans. We propose that these two factors are intimately linked; a glacially induced nutrient surplus could have led to an increase in atmospheric oxygen, paving the way for the rise of metazoan life.

  15. Effects of inositol phosphates on mineral utilization

    Energy Technology Data Exchange (ETDEWEB)

    Tao, S.H.; Fox, M.R.S.; Phillippy, B.Q.; Fry, B.E. Jr.; Johnson, M.L.; Johnston, M.R.

    1986-03-05

    The present study was designed to compare the effects of inositol tri-, tetra-, and pentaphosphate (IP3, IP4, and IP5) with those of phytic acid (IP6) on growth, development and mineral utilization of young quail. Day-old Japanese quail were fed a purified casein-gelatin control diet containing 20 ppm Zn with 0 or 8.33 mmoles/kg of each inositol phosphate, corresponding to 0.55% of IP6, for a week. As compared with controls, IP6 caused reduced body weight, poor feathering, severe perosis, decreased tibia Zn and ash, and decreased pancreas Zn and liver Mn. IP5 produced all the same adverse effects and tissue mineral changes as those by phytic acid, whereas birds fed IP3 or IP4 were normal. Moreover, IP3 and IP4 caused an increased tibia weight and ash. None of the above effects was produced by feeding inositol or inorganic phosphate. In a second experiment, the inositol phosphates were fed at either 8.33 or 16.66 mmoles/kg diet. Doubling inositol phosphate levels resulted in similar effects as those observed previously. Additionally, IP4 decreased pancreas Zn and IP3 increased tibia Zn. These results indicate that unlike IP6 and IP5, inositol phosphates with 4 or fewer phosphate groups, which can arise from hydrolysis of phytic acid during food processing, have very minor adverse effects but may be beneficial for bone mineralization.

  16. Maize endophytic bacteria as mineral phosphate solubilizers.

    Science.gov (United States)

    de Abreu, C S; Figueiredo, J E F; Oliveira, C A; Dos Santos, V L; Gomes, E A; Ribeiro, V P; Barros, B A; Lana, U G P; Marriel, I E

    2017-02-16

    In the present study, we demonstrated the in vitro activity of endophytic phosphate-solubilizing bacteria (PSB). Fifty-five endophytic PSB that were isolated from sap, leaves, and roots of maize were tested for their ability to solubilize tricalcium phosphate and produce organic acid. Partial sequencing of the 16S rRNA-encoding gene showed that the isolates were from the genus Bacillus and different species of Enterobacteriaceae. The phosphate solubilization index on solid medium and phosphate solubilization in liquid medium varied significantly among the isolates. There was a statistically significant difference (P ≤ 0.05) for both, the values of phosphate-solubilizing activity and pH of the growth medium, among the isolates. Pearson correlation was statistically significant (P ≤ 0.05) between P-solubilization and pH (R = -0.38), and between the gluconic acid production and the lowering of the pH of the liquid medium at 6 (R = 0.28) and 9 days (R = 0.39). Gluconic acid production was prevalent in all the PSB studied, and Bacillus species were most efficient in solubilizing phosphate. This is the first report on the characterization of bacterial endophytes from maize and their use as potential biofertilizers. In addition, this may provide an alternative strategy for improving the phosphorus acquisition efficiency of crop plants in tropical soils.

  17. Effect of the calcium to phosphate ratio of tetracalcium phosphate on the properties of calcium phosphate bone cement.

    Science.gov (United States)

    Burguera, Elena F; Guitian, Francisco; Chow, Laurence C

    2008-06-01

    Six different tetracalcium phosphate (TTCP) products were synthesized by solid state reaction at high temperature by varying the overall calcium to phosphate ratio of the synthesis mixture. The objective was to evaluate the effect of the calcium to phosphate ratio on a TTCP-dicalcium phosphate dihydrate (DCPD) cement. The resulting six TTCP-DCPD cement mixtures were characterized using X-ray diffraction analysis, scanning electron microscopy, and pH measurements. Setting times and compressive strength (CS) were also measured. Using the TTCP product with a Ca/P ratio of 2.0 resulted in low strength values (25.61 MPa) when distilled water was used as the setting liquid, even though conversion to hydroxyapatite was not prevented, as confirmed by X-ray diffraction. The suspected CaO presence in this TTCP may have affected the cohesiveness of the cement mixture but not the cement setting reaction, however no direct evidence of CaO presence was found. Lower Ca/P ratio products yielded cements with CS values ranging from 46.7 MPa for Ca/P ratio of 1.90 to 38.32 MPa for Ca/P ratio of 1.85. When a dilute sodium phosphate solution was used as the setting liquid, CS values were 15.3% lower than those obtained with water as the setting liquid. Setting times ranged from 18 to 22 min when water was the cement liquid and from 7 to 8 min when sodium phosphate solution was used, and the calcium to phosphate ratio did not have a marked effect on this property.

  18. Biological Removal of Phosphate Using Phosphate Solubilizing Bacterial Consortium from Synthetic Wastewater: A Laboratory Scale

    Directory of Open Access Journals (Sweden)

    Dipak Paul

    2015-01-01

    Full Text Available Biological phosphate removal is an important process having gained worldwide attention and widely used for removing phosphorus from wastewater. The present investigation was aimed to screen the efficient phosphate solubilizing bacterial isolates and used to remove phosphate from synthetic wastewater under shaking flasks conditions. Pseudomonas sp. JPSB12, Enterobacter sp. TPSB20, Flavobacterium sp. TPSB23 and mixed bacterial consortium (Pseudomonas sp. JPSB12+Enterobacter sp. TPSB20+Flavobacterium sp. TPSB23 were used for the removal of phosphate. Among the individual strains, Enterobacter sp. TPSB20 was removed maximum phosphate (61.75% from synthetic wastewater in presence of glucose as a carbon source. The consortium was effectively removed phosphate (74.15-82.50% in the synthetic wastewater when compared to individual strains. The pH changes in culture medium with time and extracellular phosphatase activity (acid and alkaline were also investigated. The efficient removal of phosphate by the consortium may be due to the synergistic activity among the individual strains and phosphatase enzyme activity. The use of bacterial consortium in the remediation of phosphate contaminated aquatic environments has been discussed.

  19. 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.

  20. Cloning and characterization of a glucose 6-phosphate/phosphate translocator from Oryza sativa

    Institute of Scientific and Technical Information of China (English)

    姜华武; 佃蔚敏; 刘非燕; 吴平

    2003-01-01

    Plastids of nongreen tissues import carbon as a source of biosynthetic pathways and energy, and glucose 6-phosphate is the preferred hexose phosphate taken up by nongreen plastids. A cDNA clone encoding glucose 6-phosphate/phosphate translocator (GPT) was isolated from a cDNA library of immature seeds of rice and named as OsGPT. The cDNA has one uninterrupted open reading frame encoding a 42 kDa polypeptide possessing transit peptide consisting of 70 amino acid residues. The OsGPT gene maps on chromosome 8 of rice and is linked to the quantitative trait locus for 1000-grain weight. The expression of OsGPT is mainly restricted to heterotrophic tissues. These results suggest that glucose 6-phosphate imported via GPT can be used for starch biosynthesis in rice nongreen plastids.

  1. Solid state 31NMR studies of the conversion of amorphous tricalcium phosphate to apatitic tricalcium phosphate.

    Science.gov (United States)

    Roberts, J E; Heughebaert, M; Heughebaert, J C; Bonar, L C; Glimcher, M J; Griffin, R G

    1991-12-01

    The hydrolytic conversion of a solid amorphous calcium phosphate of empirical formula Ca9 (PO4)6 to a poorly crystalline apatitic phase, under conditions where Ca2+ and PO4(3-) were conserved, was studied by means of solid-state magic-angle sample spinning 31P-NMR (nuclear magnetic resonance). Results showed a gradual decrease in hydrated amorphous calcium phosphate and the formation of two new PO4(3-)-containing components: an apatitic component similar to poorly crystalline hydroxyapatite and a protonated PO4(3-), probably HPO4(2-) in a dicalcium phosphate dihydrate (DCPD) brushite-like configuration. This latter component resembles the brushite-like HPO4(2-) component previously observed by 31P-NMR in apatitic calcium phosphates of biological origin. Results were consistent with previous studies by Heughebaert and Montel [18] of the kinetics of the conversion of amorphous calcium phosphate to hydroxyapatite under the same conditions.

  2. Solvothermal synthesis of strontium phosphate chloride nanowire

    Science.gov (United States)

    Lam, W. M.; Wong, C. T.; Li, Z. Y.; Luk, K. D. K.; Chan, W. K.; Yang, C.; Chiu, K. Y.; Xu, B.; Lu, W. W.

    2007-08-01

    Strontium phosphate chloride nanowire was synthesized via a solvothermal treatment of strontium tri-polyphosphate and Collin salt in 1,4-dioxane at 150 °C. The effects of 1,4-dioxane concentration on particle morphology, crystallinity and phase purity were investigated in this study. The specimen morphology was analyzed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). When the concentration of 1,4-dioxane was below 10%, micron-sized whisker was the dominant form. At 20-25% concentration of 1,4-dioxane, strontium phosphate chloride single-crystalline nanowire was 31±12 nm in diameter and 1.43±0.6 μm in length with an aspect ratio of 52.28±29.41. X-ray diffraction (XRD) pattern of this nanowire matched with that of strontium phosphate chloride (JCPDS #083-0973). When 1,4-dioxane concentration exceeded 25%, nanorod aggregate was the dominant form instead of nanowire. At 20-25% 1,4-dioxane concentration suitable strontium concentration combine with high chemical potential environment favors the formation of nanowires. By adding 1,4-dioxane impure phase such as β-strontium hydrogen phosphate, nanorod formation was suppressed. This method provides an efficient way to synthesize high aspect ratio strontium phosphate chloride nanowire. It has potential bioactive nanocomposite, high mechanical performance bioactive bone cement filler and fluorescent material applications.

  3. Sodium phosphate as an ergogenic aid.

    Science.gov (United States)

    Buck, Christopher L; Wallman, Karen E; Dawson, Brian; Guelfi, Kym J

    2013-06-01

    Legal nutritional ergogenic aids can offer athletes an additional avenue to enhance their performance beyond what they can achieve through training. Consequently, the investigation of new nutritional ergogenic aids is constantly being undertaken. One emerging nutritional supplement that has shown some positive benefits for sporting performance is sodium phosphate. For ergogenic purposes, sodium phosphate is supplemented orally in capsule form, at a dose of 3-5 g/day for a period of between 3 and 6 days. A number of exercise performance-enhancing alterations have been reported to occur with sodium phosphate supplementation, which include an increased aerobic capacity, increased peak power output, increased anaerobic threshold and improved myocardial and cardiovascular responses to exercise. A range of mechanisms have been posited to account for these ergogenic effects. These include enhancements in 2,3-Diphosphoglycerate (2,3-DPG) concentrations, myocardial efficiency, buffering capacity and adenosine triphosphate/phosphocreatine synthesis. Whilst there is evidence to support the ergogenic benefits of sodium phosphate, many studies researching this substance differ in terms of the administered dose and dosing protocol, the washout period employed and the fitness level of the participants recruited. Additionally, the effect of gender has received very little attention in the literature. Therefore, the purpose of this review is to critically examine the use of sodium phosphate as an ergogenic aid, with a focus on identifying relevant further research.

  4. Sodium ascorbyl phosphate in topical microemulsions.

    Science.gov (United States)

    Spiclin, Polona; Homar, Miha; Zupancic-Valant, Andreja; Gasperlin, Mirjana

    2003-04-30

    Sodium ascorbyl phosphate is a hydrophilic derivative of ascorbic acid, which has improved stability arising from its chemical structure. It is used in cosmetic and pharmaceutical preparations since it has many favorable effects in the skin, the most important being antioxidant action. In order to achieve this, it has to be converted into free ascorbic acid by enzymatic degradation in the skin. In the present work, o/w and w/o microemulsions composed of the same ingredients, were selected as carrier systems for topical delivery of sodium ascorbyl phosphate. We showed that sodium ascorbyl phosphate was stable in both types of microemulsion with no significant influence of its location in the carrier system. To obtain liquid microemulsions appropriate for topical application, their viscosity was increased by adding thickening agents. On the basis of rheological characterization, 4.00% (m/m) colloidal silica was chosen as a suitable thickening agent for w/o microemulsions and 0.50% (m/m) xanthan gum for the o/w type. The presence of thickening agent and the location of sodium ascorbyl phosphate in the microemulsion influenced the in vitro drug release profiles. When incorporated in the internal aqueous phase, sustained release profiles were observed. This study confirmed microemulsions as suitable carrier systems for topical application of sodium ascorbyl phosphate.

  5. [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.

  6. 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.

  7. Computational Design of Biomimetic Phosphate Scavengers

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...... that the conformational ensemble of the peptide is significantly changed, or stabilized, by the binding of phosphate anions and that binding does not take place purely as a result of a stable P-loop binding nest, but rather that multiple binding modes may be involved. Such small synthetic peptides capable of binding...... 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. Solid state NMR study calcium phosphate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Miquel, J.L.; Facchini, L.; Legrand, A.P. (Laboratoire de Physique Quantique, Paris (France). CNRS, URA421, ESPCI); Rey, C. (CNRS, Toulouse (France). ENSC. Laboratoire de Physico-chimie des Solides); Lemaitre, J. (EPF Lausanne (France). Laboratoire de Technologie des Poudres)

    1990-04-01

    High-resolution {sup 31}P and {sup 1}H NMR spectra at 40 and 121 MHz {sup 31}P and 300 MHz {sup 1}H of synthetic and biological samples of calcium phosphates have been obtained by magic angle spinning (MAS) at spinning speeds up to 6.5 kHz, and high power proton decoupling. The samples include crystalline hydroxyapatite, a deficient hydroxyapatite characterized by a Ca/P atomic ratio of 1.5, a poorly crystallized hydroxyapatite, monetite, brushite, octacalcium phosphate, {beta}-tricalcium phosphate and rabbit femoral bone. The interactions between nuclei in unlike structures and the mobility of acid protons are discussed. (author). 11 refs.; 2 figs.; 1 tab.

  9. Dicalcium phosphate cements: brushite and monetite.

    Science.gov (United States)

    Tamimi, Faleh; Sheikh, Zeeshan; Barralet, Jake

    2012-02-01

    Dicalcium phosphate cements were developed two decades ago and ever since there has been a substantial growth in research into improving their properties in order to satisfy the requirements needed for several clinical applications. The present paper presents an overview of the rapidly expanding research field of the two main dicalcium phosphate bioceramics: brushite and monetite. This review begins with a summary of all the different formulae developed to prepare dicalcium phosphate cements, and their setting reaction, in order to set the scene for the key cement physical and chemical properties, such as compressive and tensile strength, cohesion, injectability and shelf-life. We address the issue of brushite conversion into either monetite or apatite. Moreover, we discuss the in vivo behavior of the cements, including their ability to promote bone formation, biodegradation and potential clinical applications in drug delivery, orthopedics, craniofacial surgery, cancer therapy and biosensors.

  10. Zirconium phosphate binder for periclase refractories

    Energy Technology Data Exchange (ETDEWEB)

    Volceanov, E. [ICEM S.A., Bucharest (Romania). Metallurgical Research Inst.; Georgescu, M.; Volceanov, A. [Universitatea Politehnica, Bucharest (Romania). Faculty of Industrial Chemistry; Mihalache, F. [REAL S.A., Ploiesti (Romania)

    2002-07-01

    Present paper brings information concerning the physical-mechanical properties of some high thermal resistant composites with phosphate bonding obtained from periclase clinker as solid component and various zirconium phosphates solutions as liquid component: ZI, ZII and ZIII. All these solutions were prepared from hydrous zirconia and orthophosphoric acid. The batches corresponding to a weight ratio solid / liquid = 3 / 1, have shown a good hardening behavior at normal temperature, especially for the ZII binder. Such compositions exhibit a very good thermal-mechanical behavior in the temperature range 1400 C - 1750 C. X-ray diffraction and electronomicroscopy (TEM) analysis provided information concerning the evolution of phase composition and microstructure during heating of the thermal resistant specimens chemically bound with a zirconium phosphate binder. (orig.)

  11. Removal of Phosphate from Aqueous Solution with Modified Bentonite

    Institute of Scientific and Technical Information of China (English)

    唐艳葵; 童张法; 魏光涛; 李仲民; 梁达文

    2006-01-01

    Bentonite combined with sawdust and other metallic compounds was used to remove phosphate from aqueous solutions in this study. The adsorption characteristics of phosphate on the modified bentonite were investigated, including the effects of temperature, adsorbent dosage, initial concentration of phosphate and pH on removal of phosphate by conducting a series of batch adsorption experiments. The results showed that 98% of phosphate removal rate was obtained since sawdust and bentonite used in this investigation were abundantly and locally available. It is concluded that modified bentonite is a relatively efficient, low cost and easily available adsorbent for the removal of phosphate from aqueous solutions.

  12. Phosphate valorization by dry chlorination route

    OpenAIRE

    Kanari N.; Menad N.; Diot F.; Allain E.; Yvon J.

    2016-01-01

    International audience; This work deals with the extraction of phosphorus chlorinated compounds from phosphate materials using chlorination with gaseous chlorine. An industrial sample of dicalcium phosphate dihydrate, after transformation into calcium pyrophosphate (Ca 2 P 2 O 7), is subjected to reactions with Cl 2 +CO+N 2 and Cl 2 +C+N 2 at temperatures ranging from 625 to 950 °C using boat experiments. Gathering results of the thermodynamic predictions and TG/DT analysis with those of SEM ...

  13. 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... strengthening the fact that the isolates are of marine origin. Maximum activity of 5 ?mol.P.ml-1d-1 was observed for strain P6 in 4.5% NaCl Location Beaches Islands Coasts Offshore Table 1?Phosphate solubilizing bacteria in various niches. No. of cultures...

  14. Glusoce-6-phosphate dehydrogenase- History and diagnosis

    Directory of Open Access Journals (Sweden)

    K Gautam

    2016-09-01

    Full Text Available Glucose-6-phosphate dehydrogenase deficiency is the most common enzymatic defect of red blood cells, which increases the vulnerability of erythrocytes to oxidative stress leading to hemolytic anemia. Since its identification more than 60 years ago, much has been done with respect to its clinical diagnosis, laboratory diagnosis and treatment. Association of G6PD is not just limited to anti malarial drugs, but a vast number of other diseases. In this article, we aimed to review the history of Glucose-6-phosphate dehydrogenase, the diagnostic methods available along with its association with other noncommunicable diseases. 

  15. Dual mechanism of ion permeation through VDAC revealed with inorganic phosphate ions and phosphate metabolites.

    Science.gov (United States)

    Krammer, Eva-Maria; Vu, Giang Thi; Homblé, Fabrice; Prévost, Martine

    2015-01-01

    In the exchange of metabolites and ions between the mitochondrion and the cytosol, the voltage-dependent anion channel (VDAC) is a key element, as it forms the major transport pathway for these compounds through the mitochondrial outer membrane. Numerous experimental studies have promoted the idea that VDAC acts as a regulator of essential mitochondrial functions. In this study, using a combination of molecular dynamics simulations, free-energy calculations, and electrophysiological measurements, we investigated the transport of ions through VDAC, with a focus on phosphate ions and metabolites. We showed that selectivity of VDAC towards small anions including monovalent phosphates arises from short-lived interactions with positively charged residues scattered throughout the pore. In dramatic contrast, permeation of divalent phosphate ions and phosphate metabolites (AMP and ATP) involves binding sites along a specific translocation pathway. This permeation mechanism offers an explanation for the decrease in VDAC conductance measured in the presence of ATP or AMP at physiological salt concentration. The binding sites occur at similar locations for the divalent phosphate ions, AMP and ATP, and contain identical basic residues. ATP features a marked affinity for a central region of the pore lined by two lysines and one arginine of the N-terminal helix. This cluster of residues together with a few other basic amino acids forms a "charged brush" which facilitates the passage of the anionic metabolites through the pore. All of this reveals that VDAC controls the transport of the inorganic phosphates and phosphate metabolites studied here through two different mechanisms.

  16. 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.

  17. 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.

  18. Analysis of serum phosphate control and phosphate binder utilization in incident hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Farr

    2014-07-01

    Full Text Available Kimberly F Farrand,1 J Brian Copley,1 Jamie Heise,1 Moshe Fridman,2 Michael S Keith,1 Lynne Poole3 1Shire, Wayne, PA, USA; 2AMF Consulting, Los Angeles, CA, USA; 3Shire, Basingstoke, UK Abstract: The purpose of this study was to conduct a retrospective analysis of serum phosphate level variability in patients new to hemodialysis (HD and to identify patient characteristics associated with this variability. The medical records of 47,742 incident HD patients attending US outpatient dialysis centers between January 1, 2006 and March 31, 2009 were analyzed. Monthly mean serum phosphate levels determined over a 6-month evaluation period (months 4–9 after HD initiation were assigned to one of three strata: low (<1.13 mmol/L [<3.5 mg/dL]; target (1.13–1.78 mmol/L [3.5–5.5 mg/dL]; or high (>1.78 mmol/L [>5.5 mg/dL]. Patients were classified into one of six serum phosphate variability groups based on variability among monthly mean phosphate levels over the 6-month evaluation period: consistently target; consistently high; high-to-target; high-to-low; target-to-low; or consistently low. Only 15% of patients (consistently target group maintained monthly mean serum phosphate levels within the target range throughout the 6-month evaluation period. Age, Charlson comorbidity index, serum phosphate, and intact parathyroid hormone levels prior to HD initiation were strongly associated (P<0.001 with serum phosphate levels after HD initiation. Overall patient-reported phosphate binder usage increased from 35% at baseline to 52% at end of study. The low proportion of patients achieving target phosphate levels and low rates of phosphate binder usage observed during the study suggest that alternative strategies could be developed to control serum phosphate levels. Possible strategies that might be incorporated to help improve the management of hyperphosphatemia in incident HD patients include dietary modification, dialysis optimization, and earlier and sustained

  19. 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.

  20. Electrosprayed calcium phosphate coatings for biomedical purposes

    NARCIS (Netherlands)

    Leeuwenburgh, Sander Cornelis Gerardus

    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 wa

  1. Bismuth phosphates as intermediate temperature proton conductors

    DEFF Research Database (Denmark)

    Huang, Yunjie; Christensen, Erik; Shuai, Qin

    2017-01-01

    Proton conducting electrolyte materials operational in the intermediate temperature range of 200-400 °C are of special interest for applications in fuel cells and water electrolysers. Bismuth phosphates in forms of polycrystalline powders and amorphous glasses are synthesized and investigated...

  2. Superconducting oxides containing sulphate and phosphate groups

    Science.gov (United States)

    Scorzelli, R. B.; Baggio-Saitovitch, E.; Giordanengo, B.; Elmassalami, M.; Dominguez, A. B.; Bustamante Dominguez, A.

    1994-12-01

    The effects of partial substitution of Sr and Ca in Y-Ba-Cu-O related materials containing sulphate and phosphate groups have been investigated. e57Fe Mössbauer measurements were performed on samples doped with lat. % e57Fe and the spectral components related to different Cu sites and oxygen vacancies.

  3. FACTORS INFLUENCING FRICTION OF PHOSPHATE COATINGS,

    Science.gov (United States)

    surface roughness, crystalline structure , and velocity. The coefficients of friction for manganese phosphate coatings did not differ to any practical...The coefficient of friction was independent of the applied load. Velocity during dynamic testing, surface finish, and crystalline structure influenced

  4. Three-dimensionally Perforated Calcium Phosphate Ceramics

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Porous calcium phosphate ceramics were produced by compression molding using a special mold followed by sintering. The porous calcium phosphate ceramics have three-dimensional and penetrated open pores380-400μm in diameter spaced at intervals of 200μm. The layers of the linear penetration pores alternately lay perpendicular to pore direction. The porosity was 59%-65% . The Ca/P molar ratios of the porous calcium phosphate ceramics range from 1.5 to 1.85. A binder containing methyl cellulose was most effective for preparing the powder compact among vinyl acetate, polyvinyl alcohol, starch, stearic acid, methyl cellulose and their mixtures. Stainless steel, polystyrene, nylon and bamboo were used as the long columnar male dies for the penetrated open pores. When polystyrene, nylon and bamboo were used as the long columnar male dies, the dies were burned out during the sintering process. Using stainless steel as the male dies with the removal of the dies before heat treatment resulted in a higher level of densification of the calcium phosphate ceramic.

  5. Thermal stability of hydroxyapatite in biphasic calcium phosphate ceramics

    CSIR Research Space (South Africa)

    Nilen, RWN

    2008-04-01

    Full Text Available Biphasic calcium phosphate ceramics (BCP) comprising a mix of non-resorbable hydroxyapatite (HA) and resorbable b-tricalcium phosphate (b-TCP) are particularly suitable materials for synthetic bone substitute applications. In this study, HA...

  6. 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...

  7. Effect of aluminium phosphate as admixture on oxychloride cement

    Indian Academy of Sciences (India)

    M P S Chandrawat; R N Yadav

    2000-02-01

    The effect of admixing of aluminium phosphate on oxychloride cement in the matrix has been investigated. It is shown that aluminium phosphate retards the setting process of the cement and improves water-tightness.

  8. 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...

  9. MEASURED AND PREFORMED PHOSPHATE IN THE GULF OF MEXICO REGION.

    Science.gov (United States)

    Measured and preformed phosphate-phosphorous versus depth are presented for three recent cruises to the Gulf of Mexico region. Phosphate...are discussed for a hypothetical idealized station in the Gulf of Mexico . (Author)

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

    Science.gov (United States)

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

    2014-09-01

    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 Fe3+/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.

  11. Performance analysis of magnesium phosphate cement mortar containing grinding dust

    OpenAIRE

    2009-01-01

    Magnesium phosphate cement materials are formed by reacting magnesium oxide with water-soluble phosphates such as monoammonium dihydrogen phosphate (ADP), which solidifies at ambient temperature through the formation of hydrated phases in the material. Cylindrical specimens of magnesium phosphate cement were molded and varying amounts (0 to 30% weight) of grinding dust were added to the ceramic matrices. The influence of the addition of grinding dust on the characteristics of the mortars in t...

  12. Novel phosphate-based cements for clinical applications

    OpenAIRE

    2012-01-01

    This Thesis aims at the development of two novel families of inorganic phosphate cements with suitable characteristics for clinical applications in hard tissue regeneration or replacement. It is organized in two distinct parts. The first part focuses at the development of silicon-doped a-tricalcium phosphate and the subsequent preparation of a silicon-doped calcium phosphate cement for bone regeneration applications. For this purpose, silicon-doped a-tricalcium phosphate was synthesized b...

  13. Conversion of Marine Structures to Calcium Phosphate Materials: Mechanisms of Conversion Using Two Different Phosphate Solutions

    OpenAIRE

    Macha, Innocent J.; Grossin, David; Ben-Nissan, Besim

    2016-01-01

    International audience; Marine structure, coralline materials were converted to calcium phosphate using twodifferent phosphate solutions. The aim was to study the conversion mechanisms under acidic andbasic environment at moderate conditions of temperature. Crystal growth and morphology ofconverted corals were characterized by XRD and SEM respectively. The results suggested thatunder acidic conditions (H3PO4), dissolution and precipitation control and direct the crystalformation and morpholog...

  14. Phosphate Rock Fertilizer in Acid Soil:Comparing Phosphate Extraction Methods for Measuring Dissolution

    Institute of Scientific and Technical Information of China (English)

    T.S.ANSUMANA-KAWA; WANGGUANGHUO

    1998-01-01

    Three phosphate extraction methods were used to investigate the dissolution,availability and transfo-mation of Kunyang phosphate rock(KPR) in two surface acid soils.Dissolution was determined by measuring the increase in the amounts of soluble and adsorbed inorganic phosphate fractions,and did not differ signifi-cantly among the three methods.Significant correlations were obtained among P fractions got by the three extraction methods.Dissolution continued until the end of the 90-day incubation period.At the end of the period,much of the applied phosphate recovered in both soils were in the Al- and Fe-P or in the hydroxide-and bicarbonate-extractable inorganic P fractions.The dissolution of KPR in the two soils was also similar: increased addition of phosphate rock resulted in decreased dissolution.The similarity in the order and extent of dissolution in the two soils was probably due to the similarity in each soil of several factors that are known to influence phosphate rock dissolution,namely low CEC,pH,P level,and base status;and high clay and free iron and aluminum oxide contents.The results suggested that KPR could be an aternative P source in the soils are not limiting.

  15. Phosphate-responsive promoter of a Pichia pastoris sodium phosphate symporter.

    Science.gov (United States)

    Ahn, Jungoh; Hong, Jiyeon; Park, Myongsoo; Lee, Hyeokweon; Lee, Eungyo; Kim, Chunsuk; Lee, Joohwan; Choi, Eui-sung; Jung, Joon-ki; Lee, Hongweon

    2009-06-01

    To develop a functional phosphate-regulated promoter in Pichia pastoris, a phosphate-responsive gene, PHO89, which encodes a putative sodium (Na(+))-coupled phosphate symporter, was isolated. Sequencing analyses revealed a 1,731-bp open reading frame encoding a 576-amino-acid polypeptide with 12 putative transmembrane domains. The properties of the PHO89 promoter (P(PHO89)) were investigated using a bacterial lipase gene as a reporter in 5-liter jar fermentation experiments. P(PHO89) was tightly regulated by phosphate and was highly activated when the cells were grown in a phosphate-limited external environment. Compared to translation elongation factor 1alpha and the glyceraldehyde-3-phosphate dehydrogenase promoter, P(PHO89) exhibited strong transcriptional activity with higher specific productivity (amount of lipase produced/cell/h). Furthermore, a cost-effective and simple P(PHO89)-based fermentation process was developed for industrial application. These results demonstrate the potential for efficient use of P(PHO89) for controlled production of recombinant proteins in P. pastoris.

  16. Control of crystallinity and composition in calcium phosphate coatings

    Energy Technology Data Exchange (ETDEWEB)

    Cifuentes, M.; Cabanas, M.V.; Vallet-Regi, M. [Universidad Complutense de Madrid (Spain). Dept. de Quimica Inorganica y Bioinorganica

    2001-07-01

    Calcium phosphate coatings were prepared by the so-called pyrosol method. Both crystallinity and composition of obtained films can be controlled by modifying the composition of the precursor solution, surrounding atmosphere and substrate temperature. In this way, tricalcium phosphate, hydroxyapatite or biphasic hydroxyapatite/tricalcium phosphate with different crystallinity and microstructure have been prepared. (orig.)

  17. RAPID ASSOCIATION OF UNCONJUGATED BILIRUBIN WITH AMORPHOUS CALCIUM-PHOSPHATE

    NARCIS (Netherlands)

    VANDERVEERE, CN; SHOEMAKER, B; VANDERMEER, R; GROEN, AK; JANSEN, PLM; ELFERINK, RPJO

    1995-01-01

    The association of unconjugated bilirubin (UCB) with amorphous calcium phosphate was studied in vitro. To this end UCB, solubilized in different micellar bile salt solutions, was incubated with freshly prepared calcium phosphate precipitate. It was demonstrated that amorphous calcium phosphate (ACP)

  18. 40 CFR 721.3080 - Substituted phosphate ester (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted phosphate ester (generic... Substances § 721.3080 Substituted phosphate ester (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted phosphate...

  19. Osteoclastic resorption of biomimetic calcium phosphate coatings in vitro.

    NARCIS (Netherlands)

    Leeuwenburgh, S.C.G.; Layrolle, P.; Barrere, F.; Bruijn, J.G.M. de; Schoonman, J.; Blitterswijk, C.A. van; Groot, K. de

    2001-01-01

    A new biomimetic method for coating metal implants enables the fast formation of dense and homogeneous calcium phosphate coatings. Titanium alloy (Ti6Al4V) disks were coated with a thin, carbonated, amorphous calcium phosphate (ACP) by immersion in a saturated solution of calcium, phosphate, magnesi

  20. Determination of Phosphates by the Gravimetric Quimociac Technique

    Science.gov (United States)

    Shaver, Lee Alan

    2008-01-01

    The determination of phosphates by the classic quimociac gravimetric technique was used successfully as a laboratory experiment in our undergraduate analytical chemistry course. Phosphate-containing compounds are dissolved in acid and converted to soluble orthophosphate ion (PO[subscript 4][superscript 3-]). The soluble phosphate is easily…

  1. Phosphate-dependent root system architecture responses to salt stress

    NARCIS (Netherlands)

    Kawa, D.; Julkowska, M.M.; Montero Sommerfeld, H.; ter Horst, A.; Haring, M.A.; Testerink, C.

    2016-01-01

    Nutrient availability and salinity of the soil affect growth and development of plant roots. Here, we describe how phosphate availability affects root system architecture (RSA) of Arabidopsis and how phosphate levels modulate responses of the root to salt stress. Phosphate (Pi) starvation reduced ma

  2. 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...

  3. 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....

  4. 21 CFR 182.6085 - Sodium acid phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium acid phosphate. 182.6085 Section 182.6085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Sodium acid phosphate. (a) Product. Sodium acid phosphate. (b) Conditions of use. This substance...

  5. 21 CFR 582.6215 - Monobasic calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Monobasic calcium phosphate. 582.6215 Section 582.6215 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....6215 Monobasic calcium phosphate. (a) Product. Monobasic calcium phosphate. (b) Conditions of use....

  6. 21 CFR 522.1883 - Prednisolone sodium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Prednisolone sodium phosphate. 522.1883 Section... § 522.1883 Prednisolone sodium phosphate. (a) Specifications. Each milliliter of solution contains 20 milligrams (mg) prednisolone sodium phosphate (equivalent to 14.88 mg of prednisolone). (b) Sponsor. See...

  7. 21 CFR 582.6085 - Sodium acid phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium acid phosphate. 582.6085 Section 582.6085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium acid phosphate. (a) Product. Sodium acid phosphate. (b) Conditions of use. This substance...

  8. 21 CFR 184.1141b - Ammonium phosphate, dibasic.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium phosphate, dibasic. 184.1141b Section 184... Listing of Specific Substances Affirmed as GRAS § 184.1141b Ammonium phosphate, dibasic. (a) Ammonium phosphate, dibasic ((NH4)2HPO4, CAS Reg. No. 7783-28-0) is manufactured by reacting ammonia with...

  9. 21 CFR 182.6215 - Monobasic calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Monobasic calcium phosphate. 182.6215 Section 182.6215 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....6215 Monobasic calcium phosphate. (a) Product. Monobasic calcium phosphate. (b) Conditions of use....

  10. 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...

  11. Dominant oceanic bacteria secure phosphate using a large extracellular buffer.

    Science.gov (United States)

    Zubkov, Mikhail V; Martin, Adrian P; Hartmann, Manuela; Grob, Carolina; Scanlan, David J

    2015-07-22

    The ubiquitous SAR11 and Prochlorococcus bacteria manage to maintain a sufficient supply of phosphate in phosphate-poor surface waters of the North Atlantic subtropical gyre. Furthermore, it seems that their phosphate uptake may counter-intuitively be lower in more productive tropical waters, as if their cellular demand for phosphate decreases there. By flow sorting (33)P-phosphate-pulsed (32)P-phosphate-chased cells, we demonstrate that both Prochlorococcus and SAR11 cells exploit an extracellular buffer of labile phosphate up to 5-40 times larger than the amount of phosphate required to replicate their chromosomes. Mathematical modelling is shown to support this conclusion. The fuller the buffer the slower the cellular uptake of phosphate, to the point that in phosphate-replete tropical waters, cells can saturate their buffer and their phosphate uptake becomes marginal. Hence, buffer stocking is a generic, growth-securing adaptation for SAR11 and Prochlorococcus bacteria, which lack internal reserves to reduce their dependency on bioavailable ambient phosphate.

  12. 40 CFR 422.60 - Applicability; description of the sodium phosphates subcategory.

    Science.gov (United States)

    2010-07-01

    ... sodium phosphates subcategory. 422.60 Section 422.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS PHOSPHATE MANUFACTURING POINT SOURCE CATEGORY Sodium Phosphates Subcategory § 422.60 Applicability; description of the sodium phosphates subcategory....

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

    OpenAIRE

    Fernandes,Kirlene Salgado; Alvarenga,Evandro de Azevedo; Brandão, Paulo Roberto Gomes; 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 electropainting. 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 i...

  14. Kinetics of phosphate absorption in lactating dairy cows after enteral administration of sodium phosphate or calcium phosphate salts.

    Science.gov (United States)

    Grünberg, Walter; Dobbelaar, Paul; Breves, Gerhard

    2013-09-28

    Hypophosphataemia is frequently encountered in dairy cows during early lactation. Although supplementation of P is generally recommended, controversy exists over the suitability of oral P supplementation in animals with decreased or absent rumen motility. Since the effects of transruminal P absorption and the reticular groove reflex on the absorption kinetics of P are not well understood, it is unclear in how far treatment efficacy of oral P supplementation is affected by decreased rumen motility. Phosphate absorption was studied in six phosphate-depleted dairy cows fitted with rumen cannulas and treated with test solutions containing either NaH2PO4 or CaHPO4 with acetaminophen. Each animal was treated orally, intraruminally and intra-abomasally in randomised order. Absorption kinetics of P were studied and compared with the absorption kinetics of acetaminophen, a marker substance only absorbed from the small intestine. Intra-abomasal treatment with NaH2PO4 resulted in the most rapid and highest peaks in plasma inorganic P (Pi) concentration. Oral and intraruminal administration of NaH2PO4 resulted in similar increases in plasma Pi concentration from 4 to 7 h in both groups. Treatment with NaH2PO4 caused more pronounced peaks in plasma Pi concentration compared with CaHPO4. Neither transruminal P absorption nor the reticular groove reflex affected P absorption kinetics as determined by comparing plasma concentration–time curves of P and acetaminophen after administration of 1M-phosphate salt solutions. It is concluded that oral treatment with NaH2PO4 but not CaHPO4 is effective in supplementing P in hypophosphataemic cows with adequate rumen motility. Decreased rumen motility is likely to hamper the efficacy of oral phosphate treatment.

  15. Application of potential phosphate-solubilizing bacteria and organic acids on phosphate solubilization from phosphate rock in aerobic rice.

    Science.gov (United States)

    Panhwar, Qurban Ali; Jusop, Shamshuddin; Naher, Umme Aminun; Othman, Radziah; Razi, Mohd Ismail

    2013-01-01

    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.

  16. 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.

  17. The utilization of rock phosphate (natural defluorinated calcium phosphate or NDCP in laying hens diet to replace dicalcium phosphate

    Directory of Open Access Journals (Sweden)

    A.P Sinurat

    1996-06-01

    Full Text Available An experimentwas conducted to study the utilization of local rock phosphate or natural defluorinated calcium phosphate (NDCP as phosphorus source for layer chickens by using the imported dicalcium phosphate (DCP as a reference. Eight experimental diets consisted of 2 source of phosphorus (DCP and NDCP and 4 dietary total P levels (0.4, 0.5, 0.6 and 0.7% were formulated. Each diet was fed to 24 pullets (6 replicates with 4 birds each from 20 weeks of age to 14 weeks of egg production. Observations were made on feed consumption, egg production, egg weight, mortality, egg quality, Ca and P retention and ash content of tibial bones . Results showed no significant effect of different source and level of phosphorus tested on egg production (% HD, feed consumption, egg weight and mortality rates . Egg shell thickness was depressed in NDCP diet as compared with DCP, however this only occurred at firstmonth of production. It is concluded that the NDCP can be used in layers diet to replace DCP as phosphorus source. The relative biological value of phosphorus inNDCP is 96% for layers.

  18. Seed selections for crystallization of calcium phosphate for phosphorus recovery

    Institute of Scientific and Technical Information of China (English)

    SONG Yong-hui; Dietfried DONNERT; Ute BERG; Peter G. WEIDLER; Rolf NUEESCH

    2007-01-01

    Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus (P). In order to select suitable seed for P recovery from wastewater, three seeds including Apatite (AP), Juraperle (JP) and phosphate-modified Juraperle (M-JP) were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.

  19. Performance analysis of magnesium phosphate cement mortar containing grinding dust

    Directory of Open Access Journals (Sweden)

    Daniel Véras Ribeiro

    2009-03-01

    Full Text Available Magnesium phosphate cement materials are formed by reacting magnesium oxide with water-soluble phosphates such as monoammonium dihydrogen phosphate (ADP, which solidifies at ambient temperature through the formation of hydrated phases in the material. Cylindrical specimens of magnesium phosphate cement were molded and varying amounts (0 to 30% weight of grinding dust were added to the ceramic matrices. The influence of the addition of grinding dust on the characteristics of the mortars in terms of microstructure (SEM, mechanical strength and capillary water absorption was verified. The results obtained proved very satisfactory for the use of this waste as an additive in magnesium phosphate mortars.

  20. 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.

  1. Preparation and characterization of calcium phosphate biomaterials.

    Science.gov (United States)

    Calafiori, A R; Di Marco, G; Martino, G; Marotta, M

    2007-12-01

    Calcium phosphate cement (CPC) samples have been prepared with a mixture of monocalciumphosphate monohydrate (MCPM) and calcium carbonate (CC) powders, in stechiometric moles ratio 1:2.5 to obtain a Ca/P ratio of about 1.67 typical of hydroxyapatite (HAp), with or without addition of HAp. All specimens are incubated at 30 degrees C in a steam saturated air environment for 3, 6 and 15 days respectively, afterwards dried and stored under nitrogen. The calcium phosphate samples have been characterized by X-ray diffraction (XRD), Vickers hardness test (HV), diametral compression (d.c.), strength compression, and porosity evaluation. MCPM/CC mixture has a 30% HAp final concentration and is characterized by higher porosity (amount 78%) and mechanical properties useful as filler in bone segments without high mechanical stress.

  2. 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.

  3. Zinc phosphating of 6061-Al alloy using REN as additive

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shenglin; ZHANG Xiaolin; ZHANG Mingming

    2008-01-01

    Zinc phosphate coating formed on 6061-Al alloy was studied with the help of electrochemical measurements, Fourier Transform Infrared (FTIR), and Scanning Electron Microscopy (SEM), after dipping it in phosphating solutions containing different concentrations of Rare Earth Nitrate (REN). REN, which acted as an accelerator in the phosphating solution, could catalyze the surface reaction and accelerate the phosphating process. REN mainly enabled the P in the phosphate coating to exist in the form of PO43- and promoted the hydrolysis of phosphatic acid in a liquid layer at the cathodes. This resulted in the evolution of H2 at the cathodes, which increased the local pH value and in turn drove the precipitation of the phosphate coating. Additionally, REN was adsorbed on the surface of the aluminum substrates to form a gel during the phosphating process. These gel particles were good crystal seeds, which helped to form phosphate crystal nuclei and possess the function of a nucleation agent that could decrease the phosphate crystal size. The corrosion resistance of the formed zinc phosphate coatings was improved.

  4. Co-adsorption of perfluorooctane sulfonate and phosphate on boehmite: Influence of temperature, phosphate initial concentration and pH.

    Science.gov (United States)

    Qian, Jin; Shen, Mengmeng; Wang, Peifang; Wang, Chao; Hu, Jing; Hou, Jun; Ao, Yanhui; Zheng, Hao; Li, Kun; Liu, Jingjing

    2017-03-01

    The co-presence of perfluorooctane sulfonate (PFOS) and phosphate in wastewater of various industries has been detected. Removing PFOS and phosphate simultaneously before discharging sewage into natural water can decrease effectively the environmental risk caused by the combined pollution of PFOS and phosphate. In this study, laboratory batch experiments were conducted for investigating the co-adsorption of PFOS and phosphate on boehmite and the influences of temperature, phosphate initial concentration and pH on the co-adsorption. The adsorption thermodynamics and kinetics of PFOS and phosphate on boehmite were also investigated completely and systematically. The results showed that lower temperature favored the co-adsorptions of PFOS and phosphate. The adsorption of PFOS and phosphate on boehmite agreed well with the Langmuir isotherm and the adsorption parameters of thermodynamics are ΔH=-16.9 and -20.0kJmol(-1) (PFOS and phosphate), ΔS=-5.69 and -7.63Jmol(-1) K(-1) (PFOS and phosphate) and ΔG adsorption of PFOS and phosphate on boehmite is a spontaneously exothermic process. Moreover, the co-adsorption process can be described well by a pseudo-second-order kinetic model. With increasing phosphate initial concentration, more phosphate could be adsorbed on boehmite, while the adsorption of PFOS decreased at phosphate initial concentration of less than 30mgL(-1) and increased at that of larger than 30mgL(-1). In the co-adsorption process, the adsorption amount of PFOS decreased with pH increasing, but that of phosphate changed little.

  5. Removal of phosphate from aqueous solution with blast furnace slag.

    Science.gov (United States)

    Oguz, Ensar

    2004-10-18

    Blast furnace slag was used to remove phosphate from aqueous solutions. The influence of pH, temperature, agitation rate, and blast furnace slag dosage on phosphate removal was investigated by conducting a series of batch adsorption experiments. In addition, the yield and mechanisms of phosphate removal were explained on the basis of the results of X-ray spectroscopy, measurements of zeta potential of particles, specific surface area, and images of scanning electron microscopy (SEM) of the particles before and after adsorption. The specific surface area of the blast furnace slag was 0.4m(2)g(-1). The removal of phosphate predominantly has taken place by a precipitation mechanism and weak physical interactions between the surface of adsorbent and the metallic salts of phosphate. In this study, phosphate removal in excess of 99% was obtained, and it was concluded that blast furnace slag is an efficient adsorbent for the removal of phosphate from solution.

  6. Phosphate sensing and signalling in Arabidopsis thaliana

    OpenAIRE

    2013-01-01

    Phosphate (Pi) deficiency is a global problem for food production. Plants have evolved complex mechanisms to adapt to low Pi. We focused on the initial aspects of adaptation to low Pi - perception and immediate-early responses to changes in external Pi. To examine whether a labile repressor controls expression of the high affinity Pi transporter, Pht1;1, we performed electrophoretic mobility shift assays (EMSA) but observed only weak protein-DNA binding activity using extrac...

  7. Inositol phosphates induce DAPI fluorescence shift.

    Science.gov (United States)

    Kolozsvari, Bernadett; Parisi, Federica; Saiardi, Adolfo

    2014-06-15

    The polymer inorganic polyP (polyphosphate) and inositol phosphates, such as IP6 (inositol hexakisphosphate; also known as phytic acid), share many biophysical features. These similarities must be attributed to the phosphate groups present in these molecules. Given the ability of polyP to modify the excitation-emission spectra of DAPI we decided to investigate whether inositol phosphates possess the same property. We discovered that DAPI-IP6 complexes emit at approximately 550 nm when excited with light of wavelength 410-420 nm. IP5 (inositol pentakisphosphate) is also able to induce a similar shift in DAPI fluorescence. Conversely, IP3 (inositol trisphosphate) and IP4 (inositol tetrakisphosphate) are unable to shift DAPI fluorescence. We have employed this newly discovered feature of DAPI to study the enzymatic activity of the inositol polyphosphate multikinase and to monitor phytase phosphatase reactions. Finally, we used DAPI-IP6 fluorescence to determine the amount of IP6 in plant seeds. Using an IP6 standard curve this straight-forward analysis revealed that among the samples tested, borlotti beans possess the highest level of IP6 (9.4 mg/g of dry mass), whereas the Indian urad bean the lowest (3.2 mg/g of dry mass). The newly identified fluorescence properties of the DAPI-IP5 and DAPI-IP6 complexes allow the levels and enzymatic conversion of these two important messengers to be rapidly and reliably monitored.

  8. Frozen delivery of brushite calcium phosphate cements.

    Science.gov (United States)

    Grover, Liam M; Hofmann, Michael P; Gbureck, Uwe; Kumarasami, Balamurgan; Barralet, Jake E

    2008-11-01

    Calcium phosphate cements typically harden following the combination of a calcium phosphate powder component with an aqueous solution to form a matrix consisting of hydroxyapatite or brushite. The mixing process can be very important to the mechanical properties exhibited by cement materials and consequently when used clinically, since they are usually hand-mixed their mechanical properties are prone to operator-induced variability. It is possible to reduce this variability by pre-mixing the cement, e.g. by replacing the aqueous liquid component with non-reactive glycerol. Here, for the first time, we report the formation of three different pre-mixed brushite cement formulations formed by freezing the cement pastes following combination of the powder and liquid components. When frozen and stored at -80 degrees C or less, significant degradation in compression strength did not occur for the duration of the study (28 days). Interestingly, in the case of the brushite cement formed from the combination of beta-tricalcium phosphate with 2 M orthophosphoric acid solution, freezing the cement paste had the effect of increasing mean compressive strength fivefold (from 4 to 20 MPa). The increase in compression strength was accompanied by a reduction in the setting rate of the cement. As no differences in porosity or degree of reaction were observed, strength improvement was attributed to a modification of crystal morphology and a reduction in damage caused to the cement matrix during manipulation.

  9. 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.

  10. Phosphate valorization by dry chlorination route

    Directory of Open Access Journals (Sweden)

    Kanari N.

    2016-01-01

    Full Text Available This work deals with the extraction of phosphorus chlorinated compounds from phosphate materials using chlorination with gaseous chlorine. An industrial sample of dicalcium phosphate dihydrate, after transformation into calcium pyrophosphate (Ca2P2O7, is subjected to reactions with Cl2+CO+N2 and Cl2+C+N2 at temperatures ranging from 625 to 950°C using boat experiments. Gathering results of the thermodynamic predictions and TG/DT analysis with those of SEM and XRD examinations of the chlorinated residues allowed the interpretation of phenomena and reactions mechanism occurring during the calcium pyrophosphate carbochlorination. Reaction rate of Ca2P2O7 by Cl2+CO+N2 at 950°C is slowed down due to the formation of a CaCl2 liquid layer acting as a barrier for the diffusion of the reactive gases and further reaction progress. While, the carbochlorination with Cl2+C+N2 led to almost full chlorination of Ca2P2O7 at 750°C and the process proceeds with an apparent activation energy of about 104 kJ/mol between 625 and 750°C. Carbochlorination technique can be considered as an alternative and selective route for the valorization of low grade phosphates and for the phosphorus extraction from its bearing materials.

  11. Hydrothermal method for preparing calcium phosphate monoliths

    Directory of Open Access Journals (Sweden)

    García Carrodeguas Raúl

    2003-01-01

    Full Text Available A new hydrothermal route for preparing biphasic calcium phosphate monoliths is proposed. Firstly, a slurry of beta-tricalcium phosphate/ortho-phosphoric acid (b-TCP/H3PO4 is cast into the desired final shape and size to obtain a block composed of dicalcium phosphate dihydrate (DCPD and b-TCP. This block is then treated in 1.0 M Na2HPO4 at 60 °C in order to hydrolyze the DCPD into Ca10-x(HPO4x(PO4 6-x(OH2-x (CDHA and Ca8H2(PO46 .5H2O (OCP. The result is a monolithic piece which preserves the initial shape and size, but which is composed instead of CDHA, OCP, and b-TCP. During the initial stage, when the pH is slightly alkaline, the product of DCPD hydrolysis is CDHA. However, when a neutral or slightly acidic pH is reached OCP is formed. Test samples processed by this method showed complete conversion of DCPD into CDHA and OCP after 112 h of hydrolysis, and with a compressive strength of 16.2 MPa, similar to cancellous bone.

  12. Phosphate adsorption on lanthanum loaded biochar.

    Science.gov (United States)

    Wang, Zhanghong; Shen, Dekui; Shen, Fei; Li, Tianyu

    2016-05-01

    To attain a low-cost and high-efficient phosphate adsorbent, lanthanum (La) loaded biochar (La-BC) prepared by a chemical precipitation method was developed. La-BC and its pristine biochar (CK-BC) were comparatively characterized using zeta potential, BET surface area, scanning electron microscopy/energy dispersive spectrometer (SEM-EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The adsorption ability and the mechanisms during adsorption process for the La-BC samples were also investigated. La loaded on the surface of biochar can be termed as La-composites (such as LaOOH, LaONO3 and La(OH)3), leading to the decrease of negative charge and surface area of biochar. La-BC exhibited the high adsorption capacity to phosphate compared to CK-BC. Adsorption isotherm and adsorption kinetic studies showed that the Langmuir isotherm and second order model could well describe the adsorption process of La-BC, indicating that the adsorption was dominated by a homogeneous and chemical process. The calculated maximum adsorption capacity was as high as 46.37 mg g(-1) (computed in P). Thermodynamic analysis revealed that the adsorption was spontaneous and endothermic. SEM, XRD, XPS and FT-IR analysis suggested that the multi-adsorption mechanisms including precipitation, ligand exchange and complexation interactions can be evidenced during the phosphate adsorption process by La-composites in La-BC.

  13. Phosphate removal from wastewater using red mud.

    Science.gov (United States)

    Huang, Weiwei; Wang, Shaobin; Zhu, Zhonghua; Li, Li; Yao, Xiangdong; Rudolph, Victor; Haghseresht, Fouad

    2008-10-01

    Red mud, a waste residue of alumina refinery, has been used to develop effective adsorbents to remove phosphate from aqueous solution. Acid and acid-thermal treatments were employed to treat the raw red mud. The effects of different treatment methods, pH of solution and operating temperature on adsorption have been examined in batch experiments. It was found that all activated red mud samples show higher surface area and total pore volume as well as higher adsorption capacity for phosphate removal. The red mud with HCl treatment shows the highest adsorption capacity among all the red mud samples, giving adsorption capacity of 0.58 mg P/g at pH 5.5 and 40 degrees C. The adsorption capacity of the red mud adsorbents decreases with increase of pH. At pH 2, the red mud with HCl treatment exhibits adsorption of 0.8 mg P/g while the adsorption can be lowered to 0.05 mg P/g at pH 10. However, the adsorption is improved at higher temperature by increasing 25% from 30 to 40 degrees C. The kinetic studies of phosphate adsorption onto red mud indicate that the adsorption mainly follows the parallel first-order kinetics due to the presence of two acidic phosphorus species, H(2)PO(4)(-) and HPO(4)(2-). An analysis of the adsorption data indicates that the Freundlich isotherm provides a better fitting than the Langmuir model.

  14. Method for phosphate-accelerated bioremediation

    Science.gov (United States)

    Looney, Brian B.; Lombard, Kenneth H.; Hazen, Terry C.; Pfiffner, Susan M.; Phelps, Tommy J.; Borthen, James W.

    1996-01-01

    An apparatus and method for supplying a vapor-phase nutrient to contaminated soil for in situ bioremediation. The apparatus includes a housing adapted for containing a quantity of the liquid nutrient, a conduit in fluid communication with the interior of the housing, means for causing a gas to flow through the conduit, and means for contacting the gas with the liquid so that a portion thereof evaporates and mixes with the gas. The mixture of gas and nutrient vapor is delivered to the contaminated site via a system of injection and extraction wells configured to the site. The mixture has a partial pressure of vaporized nutrient that is no greater than the vapor pressure of the liquid. If desired, the nutrient and/or the gas may be heated to increase the vapor pressure and the nutrient concentration of the mixture. Preferably, the nutrient is a volatile, substantially nontoxic and nonflammable organic phosphate that is a liquid at environmental temperatures, such as triethyl phosphate or tributyl phosphate.

  15. Fabrications of zinc-releasing biocement combining zinc calcium phosphate to calcium phosphate cement.

    Science.gov (United States)

    Horiuchi, Shinya; Hiasa, Masahiro; Yasue, Akihiro; Sekine, Kazumitsu; Hamada, Kenichi; Asaoka, Kenzo; Tanaka, Eiji

    2014-01-01

    Recently, zinc-releasing bioceramics have been the focus of much attention owing to their bone-forming ability. Thus, some types of zinc-containing calcium phosphate (e.g., zinc-doped tricalcium phosphate and zinc-substituted hydroxyapatite) are examined and their osteoblastic cell responses determined. In this investigation, we studied the effects of zinc calcium phosphate (ZCP) derived from zinc phosphate incorporated into calcium phosphate cement (CPC) in terms of its setting reaction and MC3T3-E1 osteoblast-like cell responses. Compositional analysis by powder X-ray diffraction analysis revealed that HAP crystals were precipitated in the CPC containing 10 or 30wt% ZCP after successfully hardening. However, the crystal growth observed by scanning electron microscopy was delayed in the presence of additional ZCP. These findings indicate that the additional zinc inhibits crystal growth and the conversion of CPC to the HAP crystals. The proliferation of the cells and alkaline phosphatase (ALP) activity were enhanced when 10wt% ZCP was added to CPC. Taken together, ZCP added CPC at an appropriate fraction has a potent promotional effect on bone substitute biomaterials.

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

    Science.gov (United States)

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

    2017-05-01

    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 (235)U, (238)U, (226)Ra, (232)Th and (40)K was found as (45, 1031, 786, 85 and 765Bq/kg) for phosphate rocks, (28, 1234, 457, 123 and 819Bq/kg) for phosphate fertilizers, (47, 663, 550, 79 and 870Bq/kg) for phosphogypsum and (25, 543, 409, 54 and 897Bq/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.

  17. Apatite Formation from Amorphous Calcium Phosphate and Mixed Amorphous Calcium Phosphate/Amorphous Calcium Carbonate.

    Science.gov (United States)

    Ibsen, Casper J S; Chernyshov, Dmitry; Birkedal, Henrik

    2016-08-22

    Crystallization from amorphous phases is an emerging pathway for making advanced materials. Biology has made use of amorphous precursor phases for eons and used them to produce structures with remarkable properties. Herein, we show how the design of the amorphous phase greatly influences the nanocrystals formed therefrom. We investigate the transformation of mixed amorphous calcium phosphate/amorphous calcium carbonate phases into bone-like nanocrystalline apatite using in situ synchrotron X-ray diffraction and IR spectroscopy. The speciation of phosphate was controlled by pH to favor HPO4 (2-) . In a carbonate free system, the reaction produces anisotropic apatite crystallites with large aspect ratios. The first formed crystallites are highly calcium deficient and hydrogen phosphate rich, consistent with thin octacalcium phosphate (OCP)-like needles. During growth, the crystallites become increasingly stoichiometric, which indicates that the crystallites grow through addition of near-stoichiometric apatite to the OCP-like initial crystals through a process that involves either crystallite fusion/aggregation or Ostwald ripening. The mixed amorphous phases were found to be more stable against phase transformations, hence, the crystallization was inhibited. The resulting crystallites were smaller and less anisotropic. This is rationalized by the idea that a local phosphate-depletion zone formed around the growing crystal until it was surrounded by amorphous calcium carbonate, which stopped the crystallization.

  18. Proton transport properties of tin phosphate, chromotropic acid anchored onto tin phosphate and tin phenyl phosphonate

    Indian Academy of Sciences (India)

    Chithra Sumej; P P Sharmila; Nisha J Tharayil; S Suma

    2013-02-01

    Tin (IV) phosphates of the class of tetravalent metal acid (TMA) salts have been synthesized by sol–gel method. The functionalized materials of tin (IV) phosphate (SnP) like chromotropic acid anchored tin phosphate (SnPCA) and tin phenyl phosphonate (SnPP) were also synthesized. These materials have been characterized for elemental analysis (ICP–AES), thermal analysis, X-ray analysis and FTIR spectroscopy. Chemical resistivity of these materials has been accessed in acidic, basic and organic solvent media. The proton present in the structural hydroxyl groups indicates good potential for TMA salts to exhibit solid-state proton conduction. The transport properties of these materials have been explored by measuring specific proton conductance at different temperatures. Based on the specific conduction data and Arrhenius plots, a suitable mechanism has been proposed.

  19. Concomitant rock phosphate dissolution and lead immobilization by phosphate solubilizing bacteria (Enterobacter sp.).

    Science.gov (United States)

    Park, Jin Hee; Bolan, Nanthi; Megharaj, Mallavarapu; Naidu, Ravi

    2011-04-01

    This paper examines the potential value of phosphate solubilizing bacteria (Enterobacter cloacae) in the dissolution of rock phosphate (RP) and subsequent immobilization of lead (Pb) in both bacterial growth medium and soils. Enterobacter sp. showed resistance to Pb and the bacterium solubilized 17.5% of RP in the growth medium. Enterobacter sp. did not enhance Pb immobilization in solution because of acidification of bacterial medium, thereby inhibiting the formation of P-induced Pb precipitation. However, in the case of soil, Enterobacter sp. increased Pb immobilization by 6.98, 25.6 and 32.0% with the RP level of 200, 800 and 1600 mg P/kg, respectively. The immobilization of Pb in Pb-spiked soils was attributed to pyromorphite formation as indicated by XRD analysis. Inoculation of phosphate solubilizing bacteria with RP in soil can be used as an alternative technique to soluble P compounds which can cause eutrophication of surface water.

  20. Effectiveness of a rock phosphate solubilizing fungus to increase soil solution phosphate impaired by the soil phosphate sorption capacity

    Directory of Open Access Journals (Sweden)

    Nelson Walter Osorio Vega

    2015-06-01

    Full Text Available Available phosphate (P deficiency in tropical soils has been recognized as a major factor that limits soil quality and plant performance. To overcome this, it is necessary to add high amounts of soluble P-fertilizers; however, this is inefficient and costly. Alternatively, rock phosphates (RP can be used, but their low reactivity limits their use. Phosphate solubilizing microorganisms (PSM can enhance RP dissolution and, thus, improve the RP agronomic effectiveness as fertilizer. Nonetheless, their effectiveness may be impaired by the soil P fixation capacity. An experiment was carried out to assess the in vitro effectiveness of the fungus Mortierella sp. to dissolve RP in an axenic culture medium and, thus, enhance the solution P concentration in the presence of aliquots of soils with contrasting P fixation capacity. The results showed that the fungus was capable of lowering the medium pH from 7.7 to 3.0 and, thus, dissolving the RP. The presence of soil aliquots in the medium controlled the effectiveness of the fungus to increase the concentration of the soluble P. In the presence of soils with a low or medium P sorption capacity, the concentration of the soluble P was high (63.8-146.6 mg L-1 in comparison with the inoculated (soilless treatment (50.0 mg L-1 and the uninoculated control (0.7 mg L-1. By contrast, with very-high P fixing soil aliquots, the concentration of the soluble P was very low (3.6-33.1 mg L-1; in addition, in these soils, the fungus immobilized more P into its mycelia than in soils with a low or medium P fixation capacity. The capacity of a soil to fix P seems to be a good predictor for the effectiveness of this fungus to increase the soluble P concentration via RP dissolution.

  1. Phosphates sensing: two polyamino-phenolic zinc receptors able to discriminate and signal phosphates in water.

    Science.gov (United States)

    Ambrosi, Gianluca; Formica, Mauro; Fusi, Vieri; Giorgi, Luca; Guerri, Annalisa; Macedi, Eleonora; Micheloni, Mauro; Paoli, Paola; Pontellini, Roberto; Rossi, Patrizia

    2009-07-06

    Two Zn(II)-dinuclear systems were studied as receptors for phosphates; they were obtained by using the two polyamino-phenolic ligands 3,3'-bis[N,N-bis(2-aminoethyl)aminomethyl]-2,2'-dihydroxybiphenyl (L1) and 2,6-bis[N,N-bis(2-aminoethyl)aminomethyl]phenol (L2) in which the difference lies in the spacers between the two dien units, biphenol or phenol in L1 and L2, respectively. The metallo-receptors obtained are able to selectively discriminate phosphate (Pi) from pyrophosphate (PPi) and vice versa in aqueous solution in a wide range of pH (6 phosphate in a bridge disposition, fit in a different way with the different guests. Furthermore, NMR studies supported the model of interaction proposed between guests and receptors, highlighting that they are also able to bind biological phosphates such as G6P and ATP at physiological pH. Fluorescence studies showed that the receptor system based on L1 is able to signal the presence in solution of Pi and PPi at physiological pH; the presence of Pi is detected by a quenching of the emission, that of PPi by an enhancement of it. With the aid of an external colored sensor (PCV), the receptors were then used to produce simple signaling systems for phosphates based on the displacement method; the two chemosensors obtained are able to signal and quantify these anions at physiological pH, preserving the selectivity between phosphate and pyrophosphate and extending it to G6P and ATP.

  2. 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.

  3. How to assess the efficacy of phosphate binders.

    Science.gov (United States)

    Caravaca, Francisco; Caravaca-Fontán, Fernando; Azevedo, Lilia; Luna, Enrique

    The efficacy of phosphate binders is difficult to be estimated clinically. This study analyzes the changes in serum phosphate and urinary phosphate excretion after the prescription of phosphate binders (PB) in patients with chronic kidney disease stage 4-5 pre-dialysis, and the usefulness of the ratio between total urinary phosphate and protein catabolic rate (Pu/PCR) for estimating the efficacy of PB. This retrospective observational cohort study included adult chronic kidney disease patients. Biochemical parameters were determined baseline and after 45-60 days on a low phosphate diet plus PB ("binder" subgroup=260 patients) or only with dietary advice ("control" subgroup=79 patients). Phosphate load (total urinary excretion) per unit of renal function (Pu/GFR) was the best parameter correlated with serum phosphate levels (R(2)=0.61). Mean±SD level of Pu/PCR was 8.2±2.3mg of urinary phosphate per each g of estimated protein intake. After treatment with PB, serum phosphate levels decreased by 11%, urinary phosphate 22%, protein catabolic rate 7%, and Pu/PCR 15%. In the control subgroup, Pu/PCR increased by 20%. Urinary phosphate and urea nitrogen excretion correlated strongly, both baseline and after PB or dietary advice. 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. Copyright © 2016 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

  4. Deposition of calcium phosphate coatings using condensed phosphates (P2O7(4-) and P3O10(5-)) as phosphate source through induction heating.

    Science.gov (United States)

    Zhou, Huan; Hou, Saisai; Zhang, Mingjie; Yang, Mengmeng; Deng, Linhong; Xiong, Xinbo; Ni, Xinye

    2016-12-01

    In present work condensed phosphates (P2O7(4-) and P3O10(5-)) were used as phosphate source in induction heating to deposit calcium phosphate coatings. The phase, morphology, and composition of different phosphate-related coatings were characterized and compared using XRD, FTIR, and SEM analyses. Results showed that P2O7(4-)formed calcium pyrophosphate hydrate coatings with interconnected cuboid-like particles. The as-deposited calcium tripolyphosphate hydrate coating with P3O10(5-) was mainly composed of flower-like particles assembled by plate-like crystals. The bioactivity and cytocompatibility of the coatings were also studied. Moreover, the feasibility of using hybrid phosphate sources for preparing and depositing coatings onto magnesium alloy was investigated.

  5. Activation of pyrophosphate:fructose-6-phosphate 1-phosphotransferase by fructose 2,6-bisphosphate stimulates conversion of hexose phosphates to triose phosphates but does not influence accumulation of carbohydrates in phosphate-deficient tobacco cells.

    Science.gov (United States)

    Fernie, Alisdair R; Roscher, Albrecht; Ratcliffe, R. George; Kruger, Nicholas J

    2002-02-01

    The aim of this work was to investigate the contribution of fructose 2,6-bisphosphate to the regulation of carbohydrate metabolism under phosphate stress. The study exploited heterotrophic tobacco callus lines expressing a modified mammalian 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase that increased the fructose 2,6-bisphosphate content of the tissue. The phosphate status of two transgenic and one untransformed cell line was perturbed by incubation with 2-deoxyglucose, a phosphate-sequestering agent, and by growth of callus on phosphate-depleted media. 31P-NMR spectroscopy confirmed that both treatments decreased cellular levels of inorganic phosphate and phosphorylated metabolites. Despite large decreases in the amounts of phosphate esters, UDPglucose and adenylates in response to phosphate deficiency, the fructose 2,6-bisphosphate content of each line was unaffected by 2-deoxyglucose and increased during growth on phosphate-limited media. Short-term treatment of callus with 2-deoxyglucose had only minor effects on the carbohydrate status of each line, whereas long-term phosphate deficiency caused an increase in starch and a decrease in soluble sugar content in both transgenic and control lines. There were no consistent differences between the three callus lines in metabolism of [U-14C]glucose in response to incubation with 2-deoxyglucose. In contrast, there was a decrease in partitioning of label into glycolytic products (particularly organic acids) in untransformed callus during growth on phosphate-depleted medium. This decrease was greatly attenuated in the transgenic lines with increased fructose 2,6-bisphosphate content. This suggests that the conversion of hexose phosphates to triose phosphates is constrained under phosphate-deficient conditions, and that this restriction can be relieved by activation of pyrophosphate:fructose-6-phosphate 1-phosphotransferase. However, since the transgenic and control lines did not differ in the extent to which the

  6. Topotactic exchange and intercalation of calcium phosphate

    Science.gov (United States)

    Lima, Cicero B. A.; Airoldi, Claudio

    2004-11-01

    The precursor (NH 4) 2Ca(H 2PO 4) 2ṡH 2O (CaAP) compound was obtained by combining a calcium chloride solution with dibasic ammonium phosphate. After submitting it to a thermal treatment, crystalline calcium phosphate, Ca(H 2PO 4) 2ṡH 2O (CaP) was isolated. X-ray diffraction patterns for this compound indicated good crystallinity, with a peak at 2θ=12.8°, to give an interlamellar distance of 697 pm, which changed to 1550 pm, when the reaction employed phenylphosphonic acid, and to 1514 pm when intercalated with methylamine. Phosphorus and calcium analysis from colorimetric and gravimetric methods gave for CaP 24.2 and 15.8%, respectively, to yield a P:Ca molar ratio equal to two. The phosphorus nuclear magnetic resonance presented a peak centered at -1.23 ppm, in agreement with the existence of phosphate groups in protonated form. CaAP showed a mass loss of 21.2% in the 466 to 541 K interval due to ammonia and water elimination to yield Ca(PO 3) 3, and CaP can be dehydrated at 440 K for 6 h. A topotactical exchange occurred when CaP is intercalated with methylamine or reacted with phenylphosphonic acid to yield the phosphonate compound and the infrared spectrum of the resulting compound clearly showed the presence of PO 4 and PO 3 groups. The topotactic exchange was also demonstrated by X-ray diffractometry in following the stages of decomposition from 527 to 973 K.

  7. Nucleotides and inorganic phosphates as potential antioxidants.

    Science.gov (United States)

    Richter, Yael; Fischer, Bilha

    2006-11-01

    Highly reactive OH radicals, formed in an iron-ion catalyzed Fenton reaction, are implicated in many pathological conditions. The quest for Fenton reaction inhibitors, either radical scavenger or metal-ion chelator antioxidants, spans the previous decades. Purine nucleotides were previously studied as natural modulators of the Fenton reaction; however, the modulatory role of purine nucleotides remained in dispute. Here, we have resolved this long-standing dispute and demonstrated a concentration-dependent biphasic modulation of the Fenton reaction by nucleotides. By electron spin resonance measurements with 0.1 mM Fe(II), we observed an increase of *OH production at low purine nucleotide concentrations (up to 0.15 mM), while at higher nucleotide concentrations, an exponential decay of *OH concentration was observed. We found that the phosphate moiety, not the nucleoside, determines the pro/antioxidant properties of a nucleotide, suggesting a chelation-based modulation. Furthermore, the biphasic modulation mode is probably due to diverse nucleotide-Fe(II) complexes formed in a concentration-dependent manner. At ATP concentrations much greater than Fe(II) concentrations, multiligand chelates are formed which inhibit the Fenton reaction owing to a full Fe(II) coordination sphere. In addition to natural nucleotides, we investigated a series of base- or phosphate-modified nucleotides, dinucleotides, and inorganic phosphates, as potential biocompatible antioxidants. Ap5A, inorganic thiophosphate and ATP-gamma-S proved highly potent antioxidants with IC50 values of 40, 30, and 10 microM, respectively. ATP-gamma-S proved 100 and 20 times more active than ATP and the potent antioxidant Trolox, respectively. In the presence of 30 microM ATP-gamma-S no *OH was detected after 5 min in the Fenton reaction mixture. The most potent antioxidants identified inhibit the Fenton reaction by forming full coordination sphere chelates.

  8. Phosphate solubilizing bacteria and their role in plant growth promotion.

    Science.gov (United States)

    Rodríguez, H; Fraga, R

    1999-10-01

    The use of phosphate solubilizing bacteria as inoculants simultaneously increases P uptake by the plant and crop yield. Strains from the genera Pseudomonas, Bacillus and Rhizobium are among the most powerful phosphate solubilizers. The principal mechanism for mineral phosphate solubilization is the production of organic acids, and acid phosphatases play a major role in the mineralization of organic phosphorous in soil. Several phosphatase-encoding genes have been cloned and characterized and a few genes involved in mineral phosphate solubilization have been isolated. Therefore, genetic manipulation of phosphate-solubilizing bacteria to improve their ability to improve plant growth may include cloning genes involved in both mineral and organic phosphate solubilization, followed by their expression in selected rhizobacterial strains. Chromosomal insertion of these genes under appropriate promoters is an interesting approach.

  9. Factors determining rock phosphate solubilization by microorganisms isolated from soil.

    Science.gov (United States)

    Nahas, E

    1996-11-01

    Forty two soil isolates (31 bacteria and 11 fungi) were studied for their ability to solubilize rock phosphate and calcium phosphate in culture medium. Eight bacteria and 8 fungi possessed solubilizing ability. Pseudomonas cepacia and Penicillium purpurogenum showed the highest activity. There was a correlation between final pH value and titratable acidity (r=-0.29 to -0.87) and between titratable acidity and soluble phosphate (r=0.22 to 0.99). Correlation values were functions of insoluble phosphate and of the group of microorganisms considered. A high correlation was observed between final pH and soluble phosphate only for the rock phosphates inoculated with the highest concentration of solubilizing bacteria (r=-0.73 to -0.98).

  10. 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.

  11. Root architecture remodeling induced by phosphate starvation.

    Science.gov (United States)

    Sato, Aiko; Miura, Kenji

    2011-08-01

    Plants have evolved efficient strategies for utilizing nutrients in the soil in order to survive, grow, and reproduce. Inorganic phosphate (Pi) is a major macroelement source for plant growth; however, the availability and distribution of Pi are varying widely across locations. Thus, plants in many areas experience Pi deficiency. To maintain cellular Pi homeostasis, plants have developed a series of adaptive responses to facilitate external Pi acquisition, limit Pi consumption, and adjust Pi recycling internally under Pi starvation conditions. This review focuses on the molecular regulators that modulate Pi starvation-induced root architectural changes.

  12. The pentose phosphate pathway and cancer.

    Science.gov (United States)

    Patra, Krushna C; Hay, Nissim

    2014-08-01

    The pentose phosphate pathway (PPP), which branches from glycolysis at the first committed step of glucose metabolism, is required for the synthesis of ribonucleotides and is a major source of NADPH. NADPH is required for and consumed during fatty acid synthesis and the scavenging of reactive oxygen species (ROS). Therefore, the PPP plays a pivotal role in helping glycolytic cancer cells to meet their anabolic demands and combat oxidative stress. Recently, several neoplastic lesions were shown to have evolved to facilitate the flux of glucose into the PPP. This review summarizes the fundamental functions of the PPP, its regulation in cancer cells, and its importance in cancer cell metabolism and survival.

  13. Biogenesis of the mitochondrial phosphate carrier

    OpenAIRE

    Zara, Vincenzo; Rassow, Joachim; Wachter, Elmar; Tropschug, Maximilian; Palmieri, Ferdinando; Neupert, Walter; Pfanner, Nikolaus

    1991-01-01

    The mitochondrial phosphate carrier (PiC) is a member of the family of inner-membrane carrier proteins which are generally synthesized without a cleavable presequence. Surprisingly, the cDNA sequences of bovine and rat PiC suggested the existence of an amino-terminal extension sequence in the precursor of PiC. By expressing PiC in vitro, we found that PiC is indeed synthesized as a larger precursor. This precursor was imported and proteolytically processed by mitochondria, whereby the correct...

  14. 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.

  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. PROCESS FOR THE RECOVERY OF URANIUM FROM PHOSPHATIC ORE

    Science.gov (United States)

    Long, R.L.

    1959-04-14

    A proccss is described for the recovery of uranium from phosphatic products derived from phosphatic ores. It has been discovered that certain alkyl phosphatic, derivatives can be employed in a direct solvent extraction operation to recover uranium from solid products, such as superphosphates, without first dissolving such solids. The organic extractants found suitable include alkyl derivatives of phosphoric, pyrophosphoric, phosof the derivative contains from 4 to 7 carbon atoms. A diluent such as kerosene is also used.

  17. Sorbents for phosphate removal from agricultural drainage water

    DEFF Research Database (Denmark)

    Lyngsie, Gry

    -through cells. Further, in order to improve our understanding of phosphate sorption reactions and kinetics for different types of commercial available PSMs, three different types were studied by means of isothermal titration calorimetry, sorption isotherms, sequential extractions and SEM-EDS. In conclusion......, of the materials investigated the results from phosphate sorption and desorption studies clearly demonstrate that regarding phosphate sorption affinity, capacity and reactivity, iron oxide based PSM is superior as a filter material compared to the other tested materials....

  18. Enriching vermicompost by nitrogen fixing and phosphate solubilizing bacteria.

    Science.gov (United States)

    Kumar, V; Singh, K P

    2001-01-01

    The effect of inoculation of vermicompost with nitrogen-fixing Azotobacter chroococcum strains, Azospirillum lipoferum and the phosphate solubilizing Pseudomonas striata on N and P contents of the vermicompost was assessed. Inoculation of N2 fixing bacteria into vermicompost increased contents of N and P. Enriching vermicompost with rock phosphate improved significantly the available P when inoculated with P. striata. During the incubation period, the inoculated bacterial strains proliferated rapidly, fixed N and solubilized added and native phosphate.

  19. Calcium phosphate precipitation modeling in a pellet reactor

    OpenAIRE

    Montastruc, Ludovic; Azzaro-Pantel, Catherine; Cabassud, Michel; Biscans, Béatrice

    2002-01-01

    The calcium phosphate precipitation in a pellet reactor can be evaluated by two main parameters: the phosphate conversion ratio and the phosphate removal efficiency. The conversion ratio depends mainly on the pH. The pellet reactor efficiency depends not only on pH but also on the hydrodynamical conditions. An efficiency model based on a thermochemical precipitation approach and an orthokinetic aggregation model is presented. In this paper, the results show that optimal conditions for pellet ...

  20. THE EFFICACY OF USING PHOSPHATE SOLUBILIZING MICROORGANISMS IN GRANULAR BIOFERTILIZERS WITH PHOSPHATE ORE

    Directory of Open Access Journals (Sweden)

    Dunaitsev I. A.

    2016-03-01

    Full Text Available Two granular formulations of phosphorus biofertilizers combining rock phosphate and two highly active phosphate solubilizing strains: Acinetobacter species 305 and Pseudomonas species 181а have been investigated. Granules of about 3 mm in size were obtained by contact-convective drying of a mixture of ground ore, concentrated biomass of two different strains, starch and glucose. Micro granules with size of 0.1- 0.5 mm were obtained by spray drying the biomass of two different strains and application of dried cells on the particles of the ground ore. Starch was used as a binder. In the model liquid medium it was shown that the microorganisms have retained the ability to solubilize mineral phosphates in granular formulations prepared. In laboratory pot trial on marigold (Tagetes patula it was demonstrated that both formulations of biofertilizer increased the dry weight of the plants to the same level as that of chemical fertilizer - double superphosphate, but were inferior in the concentration of phosphorus in plants. Both formulations exceeded the effectiveness of rock phosphate and biomass used as biofertilizers both separately and jointly. No significant differences were noted between the two strains and the two granular formulations both for plant dry weight, and the content of phosphorus therein. Both granular formulations of biofertilizer retained their structure and avoided aggregating over a year of storage at 4 oC. The average persistence of living cells in the microbeads was about 1.5%, in granules - 32 %

  1. Phosphate acquisition efficiency and phosphate starvation tolerance locus (PSTOL1) in rice

    Indian Academy of Sciences (India)

    Arijit Mukherjee; Sutanu Sarkar; Amrita Sankar Chakraborty; Roshan Yelne; Vinay Kavishetty; Tirthankar Biswas; N. Mandal; Somnath Bhattacharyya

    2014-12-01

    Phosphate availability is a major factor limiting tillering, grain filling vis-à-vis productivity of rice. Rice is often cultivated in soil like red and lateritic or acid, with low soluble phosphate content. To identify the best genotype suitable for these types of soils, P acquisition efficiency was estimated from 108 genotypes. Gobindabhog, Tulaipanji, Radhunipagal and Raghusail accumulated almost equal amounts of phosphate even when they were grown on P-sufficient soil. Here, we have reported the presence as well as the expression of a previously characterized rice gene, phosphate starvation tolerance locus (PSTOL1) in a set of selected genotypes. Two of four genotypes did not show any detectable expression but carried the gene. One mega cultivar, Swarna did not possess this gene but showed high P-deficiency tolerance ability. Increase of root biomass, not length, in P-limiting situations might be considered as one of the selecting criteria at the seedling stage. Neither the presence of PSTOL1 gene nor its closely-linked SSR RM1261, showed any association with P-deficiency tolerance among the 108 genotypes. Not only this, but the presence of PSTOL1 in recombinant inbred line (RIL) developed from a cross between Gobindabhog and Satabdi, also did not show any linkage with P-deficiency tolerance ability. Thus, before considering PSTOL1 gene in MAB, its expression and role in P-deficiency tolerance in the donor parent must be ascertained.

  2. StMYB44 negatively regulates phosphate transport by suppressing expression of PHOSPHATE1 in potato

    Science.gov (United States)

    Phosphorus is an important macronutrient for plant growth, but often deficient in soil. To understand the molecular basis of the complex responses of potato (Solanum tuberosum L.) to phosphate (Pi) deficiency stress, the RNA-Seq approach was taken to identify genes responding to Pi starvation in pot...

  3. Dependence of Streptococcus lactis Phosphate Transport on Internal Phosphate Concentration and Internal pH

    NARCIS (Netherlands)

    POOLMAN, B; NIJSSEN, RMJ; KONINGS, WN

    1987-01-01

    Uptake of phosphate by Streptococcus lactis ML3 proceeds in the absence of a proton motive force, but requires the synthesis of ATP by either arginine or lactose metabolism. The appearance of free Pi internally in arginine-metabolizing cells corresponded quantitatively with the disappearance of extr

  4. The potential of phosphate solubilizing bacteria isolated from sugarcane wastes for solubilizing phosphate

    Directory of Open Access Journals (Sweden)

    Atekan

    2014-07-01

    Full Text Available Most of P in agricultural soils is in unavailable forms for plant growth. Phosphate solubilizing bacteria can increase soil P availability. This study was aimed to isolate phosphate solubilizing bacteria from sugarcane waste compost and to test ability of the isolated bacterial to dissolve phosphate. The bacteria were isolated from three types of sugarcane waste, i.e. filter cake compost, bagasse compost, and a mixture of filter cake + bagasse + trash biomass compost. The potential colony was further purified by the Pikovskaya method on selective media. Eight isolates of phosphate solubilizing bacteria were obtained from all wasted studied. Amongst them, T-K5 and T-K6 isolates were superior in dissolving P from Ca3(PO42 in the media studied. The two isolates were able to solubilize P with solubilizing index of 1.75 and 1.67 for T-K5 and T-K6, respectively. Quantitatively, T-K6 isolate showed the highest P solubilization (0.74 mg / L, followed by T-K5 isolate (0.56 mg / L, while the lowest P solubilization (0.41 mg / L was observed for T-K4 isolate. The increase of soluble P was not always followed by the decrease in pH.

  5. Lipid phosphate phosphohydrolase-1 degrades exogenous glycerolipid and sphingolipid phosphate esters.

    Science.gov (United States)

    Jasinska, R; Zhang, Q X; Pilquil, C; Singh, I; Xu, J; Dewald, J; Dillon, D A; Berthiaume, L G; Carman, G M; Waggoner, D W; Brindley, D N

    1999-06-15

    Lipid phosphate phosphohydrolase (LPP)-1 cDNA was cloned from a rat liver cDNA library. It codes for a 32-kDa protein that shares 87 and 82% amino acid sequence identities with putative products of murine and human LPP-1 cDNAs, respectively. Membrane fractions of rat2 fibroblasts that stably expressed mouse or rat LPP-1 exhibited 3.1-3. 6-fold higher specific activities for phosphatidate dephosphorylation compared with vector controls. Increases in the dephosphorylation of lysophosphatidate, ceramide 1-phosphate, sphingosine 1-phosphate and diacylglycerol pyrophosphate were similar to those for phosphatidate. Rat2 fibroblasts expressing mouse LPP-1 cDNA showed 1.6-2.3-fold increases in the hydrolysis of exogenous lysophosphatidate, phosphatidate and ceramide 1-phosphate compared with vector control cells. Recombinant LPP-1 was located partially in plasma membranes with its C-terminus on the cytosolic surface. Lysophosphatidate dephosphorylation was inhibited by extracellular Ca2+ and this inhibition was diminished by extracellular Mg2+. Changing intracellular Ca2+ concentrations did not alter exogenous lysophosphatidate dephosphorylation significantly. Permeabilized fibroblasts showed relatively little latency for the dephosphorylation of exogenous lysophosphatidate. LPP-1 expression decreased the activation of mitogen-activated protein kinase and DNA synthesis by exogenous lysophosphatidate. The product of LPP-1 cDNA is concluded to act partly to degrade exogenous lysophosphatidate and thereby regulate its effects on cell signalling.

  6. Phosphate Esters, Thiophosphate Esters and Metal Thiophosphates as Lubricant Additives

    Directory of Open Access Journals (Sweden)

    David W. Johnson

    2013-12-01

    Full Text Available Phosphate esters, thiophosphate esters and metal thiophosphates have been used as lubricant additives for over 50 years. While their use has been extensive, a detailed knowledge of how they work has been a much more recent development. In this paper, the use of phosphate esters and thiophosphate esters as anti-wear or extreme pressure additives is reviewed with an emphasis on their mechanism of action. The review includes the use of alkyl phosphates, triaryl phosphates and metal containing thiophosphate esters. The mechanisms of these materials interacting with a range of iron and steel based bearing material are examined.

  7. 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...

  8. REMOVAL OF PHOSPHATES FROM WATER BY PILLARED RECTORITE

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The presence of trace phosphates in treated wastewater from municipalities and industries is often responsible for eutrophication problems in lakes, rivers, and other water bodies. In this paper,we report the removal of PO43- from water by using a pillared rectorite that we synthesized recently. The results show that cross-linking can significantly increase the adsorbing capacity of Na-rectorite for phosphates. The pH, the concentrations of F, NH4+ and COD are main factors, which affect the results for pillared rectorite to adsorb phosphates from water. The OH-, and F- ions decrease the capacity to adsorb phosphates, while the COD and NH4+ ions increase it.

  9. Pathogenic Mineralization of Calcium Phosphate on Human Heart Valves

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    When calcium phosphate forms in soft tissues such as blood vessels and heart valves, it causes disease. The abnormal formation of calcium phosphate is called pathogenic mineralization or pathogenic calcification. Cases of rheumatic heart disease (RHD) always occur with fibrotic and calcified tissue of heart valve. In this article, samples taken from calcified human heart valves were studied. The characterization was performed by scanning electronic micrascope, X-ray Diffraction and transmission electron microscopy with selective diffraction patterns. It is found for the first time that calcium phosphate grains existing in the calcified human heart valves contain octacalcium phosphate (OCP).

  10. First continuous phosphate record from Greenland ice cores

    Directory of Open Access Journals (Sweden)

    H. A. Kjær

    2011-11-01

    Full Text Available A continuous and highly sensitive absorption method for detection of soluble phosphate in ice cores has been developed using a molybdate reagent and a 2 m liquid waveguide (LWCC. The method is optimized to meet the low concentrations of phosphate in Greenland ice, it has a detection limit of around 0.1 ppb and a depth resolution of approximately 2 cm. The new method has been applied to obtain phosphate concentrations from segments of two Northern Greenland ice cores: from a shallow firn core covering the most recent 120 yr and from the recently obtained deep NEEM ice core in which sections from the late glacial period have been analysed. Phosphate concentrations in 20th century ice are around 0.32 ppb with no indication of anthropogenic influence in the most recent ice. In the glacial part of the NEEM ice core concentrations in the cold stadial periods are significantly higher, in the range of 6–24 ppb, while interstadial ice concentrations are around 2 ppb. In the shallow firn core, a strong correlation between concentrations of phosphate and insoluble dust suggests a similar deposition pattern for phosphate and dust. In the glacial ice, phosphate and dust also correlate quite strongly, however it is most likely that this correlation originates from the phosphate binding to dust during transport, with only a fraction coming directly from dust. Additionally a constant ratio between phosphate and potassium concentrations shows evidence of a possible biogenic land source.

  11. Electron microscopy of some rock phosphate dissolving bacteria and fungi.

    Science.gov (United States)

    Gaur, A C; Arora, D; Prakash, N

    1979-01-01

    Bacteria Pseudomonas striata, Bacillus polymyxa, B. megaterium and B. pulvifaciens, and fungi Aspergillus awamori, A. niger and Penicillium digitatum dissolve tricalcium phosphate and, much less, Mussorie and Udaipur rock phosphate. The solubilizing power of fungi was higher than that of bacteria, the highest being with A. awamori and A. niger, and with P. striata. Electron microscopy of the various cultures showed an electron-dense layer on the bacterial surface after negative staining. The size of phosphate particles decreased by the microbial action, with tricalcium phosphate from 140--250 to 30--90 nm after three weeks of incubation.

  12. [The solubilization of four insoluble phosphates by some microorganisms].

    Science.gov (United States)

    Zhao, Xiaorong; Lin, Qimei; Li, Baoguo

    2002-04-01

    Four insoluble phosphates of ferric phosphate (Fe-P), aluminum phosphate (Al-P), fluorapatite (FAP) and rock phosphate (RP) were used as a sole phosphorus resource for some phosphate-solubilizing microorganisms. It was found that there was significant difference in solubilizing these phosphates by the tested isolates. The fungi normally were more powerful than the bacteria in dissolving the phsophates. The microorganisms generally solubilized more phosphate when supplied with NO3- than with NH4+. However, the isolates of 2TCiF2 and 4TCiF6 had much higher capacity to solubilize FAP and Al-P respectively in NH4+ medium. Most of the isolates solubilized readily FAP and RP, and then Al-P. Ferric phosphate was the least soluble to these isolates. Only isolate 2TCiF2 showed strong ability to solubilize Fe-P. In particular, two Aspergillus sp. had much higher capacity of dissolving Fe-P when suppled with NO3-. The isolates of Evwinia sp. 4TCRi22 and Enterobacter sp. 1TCRi15 had higher capacity of solubilizing FAP. But two Arthrobacter sp. showed the highest activity in RP medium. It is supposed that complexion of organic acids with metals may be the main reason for these isolates to solubilize the phosphates. However, other chelant substances may be much more important for Enterobacter sp. and Erwinia sp. to release phosphorus from the phsphates.

  13. [Synthetic calcium phosphate ceramics in secondary alveoloplasty].

    Science.gov (United States)

    Corre, P; Khonsari, R-H; Laure, B; Elamrani, K; Weiss, P; Mercier, J-M

    2012-04-01

    Bone substitutes are rarely used in the reconstruction of cleft lip and palate. The graft material of choice is cancellous bone, harvested in the hip or tibia. Tibial harvesting may lead to postoperative morbidity, or even complications. This has lead surgeons to develop alternative solution. We present a secondary alveolar bone grafting technique using synthetic calcium phosphate ceramics. A patient presenting with a complete unilateral cleft lip and palate was treated by alveolar bone grafting at the age of nine years, using a mixture of autologous bone, harvested on the operative field, and particles of biphasic calcium phosphate (BCP); the graft was included in a platelet rich plasma (PRP) gel. The patient was followed up for eight years after the procedure. No sign of early or late infection was observed. At the end of facial growth, the cuspid had erupted correctly in a safe periodontal environment. Sequential X-rays showed complete filling of the initial bone defect, progressive resorption of ceramics, and spontaneous eruption of the cuspid. In this long-term follow-up report, the use of BCP mixed with autologous bone did not interfere with dental eruption or maxilla growth. A second bone-harvesting site was thus avoided. BCP could be a suitable alternative to autologous bone graft for secondary alveoloplasty. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  14. Expanding sapphyrin: towards selective phosphate binding.

    Science.gov (United States)

    Katayev, Evgeny A; Boev, Nikolay V; Myshkovskaya, Ekaterina; Khrustalev, Victor N; Ustynyuk, Yu A

    2008-01-01

    The anion-templated syntheses and binding properties of novel macrocyclic oligopyrrole receptors in which pyrrole rings are linked through amide or imine bonds are described. The efficient synthesis was accomplished by anion-templated [1+1] Schiff-base condensation and acylation macrocyclization reactions. Free receptors and their host-guest complexes with hydrochloric acid, acetic acid, tetrabutylammonium chloride, and hydrogen sulfate were analyzed by single-crystal X-ray diffraction analysis. Stability constants with different tetrabutylammonium salts of inorganic acids were determined by standard 1H NMR and UV/Vis titration techniques in [D6]DMSO/0.5% water solution. According to the titration data, receptors containing three pyrrole rings (10 and 12) exhibit high affinity (log Ka=5-7) for bifluoride, acetate, and dihydrogen phosphate, and interact weakly with chloride and hydrogen sulfate. The amido-bipyrrole receptors 11 and 13 with four pyrrole rings exhibit 10(4)- and 10(2)-fold selectivity for dihydrogen phosphate, respectively, as inferred from competitive titrations in the presence of tetrabutylammonium acetate.

  15. Phosphoinositide 5-Phosphate and Phosphoinositide 4-Phosphate Trigger Distinct Specific Responses of Arabidopsis Genes: Genome-Wide Expression Analyses

    OpenAIRE

    2006-01-01

    Phosphoinositide phosphates, PtdInsP, are important components of the cell lipid pool that can function as messengers in diverse cellular processes. Lack of information on downstream targets, however, has impeded our understanding of the potential of lipid-signaling to influence gene activity. Our goals here were to identify genes that altered expression in the presence of two isomeric monophosphate lipid messengers (Phosphoinositide 5-Phosphate, PtdIns(5)P, and Phosphoinositide 4-Phosphate, ...

  16. Synthesis of a series of maltotriose phosphates with an evaluation of the utility of a fluorous phosphate protecting group.

    Science.gov (United States)

    Liu, Lin; Pohl, Nicola L B

    2013-03-22

    A series of methyl maltotrioside phosphates were synthesized for application in the determination of the actual molecular substrate of the Lafora enzyme involved in Lafora disease. Several different synthetic routes were applied for the successful synthesis of six methyl maltotrioside phosphate regioisomers. The utility of a new fluorous phosphate protecting group was also evaluated, but its utility was found to be limited in this particular late stage introduction.

  17. Erythritol feeds the pentose phosphate pathway via three new isomerases leading to D-erythrose-4-phosphate in Brucella.

    Science.gov (United States)

    Barbier, Thibault; Collard, François; Zúñiga-Ripa, Amaia; Moriyón, Ignacio; Godard, Thibault; Becker, Judith; Wittmann, Christoph; Van Schaftingen, Emile; Letesson, Jean-Jacques

    2014-12-16

    Erythritol is an important nutrient for several α-2 Proteobacteria, including N2-fixing plant endosymbionts and Brucella, a worldwide pathogen that finds this four-carbon polyol in genital tissues. Erythritol metabolism involves phosphorylation to L-erythritol-4-phosphate by the kinase EryA and oxidation of the latter to L-3-tetrulose 4-phosphate by the dehydrogenase EryB. It is accepted that further steps involve oxidation by the putative dehydrogenase EryC and subsequent decarboxylation to yield triose-phosphates. Accordingly, growth on erythritol as the sole C source should require aldolase and fructose-1,6-bisphosphatase to produce essential hexose-6-monophosphate. However, we observed that a mutant devoid of fructose-1,6-bisphosphatases grew normally on erythritol and that EryC, which was assumed to be a dehydrogenase, actually belongs to the xylose isomerase superfamily. Moreover, we found that TpiA2 and RpiB, distant homologs of triose phosphate isomerase and ribose 5-phosphate isomerase B, were necessary, as previously shown for Rhizobium. By using purified recombinant enzymes, we demonstrated that L-3-tetrulose-4-phosphate was converted to D-erythrose 4-phosphate through three previously unknown isomerization reactions catalyzed by EryC (tetrulose-4-phosphate racemase), TpiA2 (D-3-tetrulose-4-phosphate isomerase; renamed EryH), and RpiB (D-erythrose-4-phosphate isomerase; renamed EryI), a pathway fully consistent with the isotopomer distribution of the erythrose-4-phosphate-derived amino acids phenylalanine and tyrosine obtained from bacteria grown on (13)C-labeled erythritol. D-erythrose-4-phosphate is then converted by enzymes of the pentose phosphate pathway to glyceraldehyde 3-phosphate and fructose 6-phosphate, thus bypassing fructose-1,6-bisphosphatase. This is the first description to our knowledge of a route feeding carbohydrate metabolism exclusively via D-erythrose 4-phosphate, a pathway that may provide clues to the preferential metabolism of

  18. Characterization of three putative xylulose 5-phosphate/fructose 6-phosphate phosphoketolases in the cyanobacterium Anabaena sp. PCC 7120.

    Science.gov (United States)

    Moriyama, Takashi; Tajima, Naoyuki; Sekine, Kohsuke; Sato, Naoki

    2015-01-01

    Xylulose 5-phosphate/fructose 6-phosphate phosphoketolase (Xfp) is a key enzyme in the central carbohydrate metabolism in heterofermentative bacteria, in which enzymatic property of Xfps is well characterized. This is not the case in other microbes. The cyanobacterium Anabaena sp. PCC 7120 possesses three putative genes encoding Xfp, all1483, all2567, and alr1850. We purified three putative Xfps as recombinant proteins. The results of gel filtration indicated that these proteins form homomultimer complex. All1483 and All2567 showed phosphoketolase activity, whereas Alr1850 did not show the activity. Kinetic analyses demonstrated that substrates, fructose 6-phosphate and inorganic phosphate, are cooperatively bound to enzymes positively and negatively, respectively.

  19. Is parenteral phosphate replacement in the intensive care unit safe?

    Science.gov (United States)

    Agarwal, Banwari; Walecka, Agnieszka; Shaw, Steve; Davenport, Andrew

    2014-02-01

    Hypophosphatemia is well recognized in the intensive care setting, associated with refeeding and continuous forms of renal replacement therapy (CCRT). However, it is unclear as to when and how to administer intravenous phosphate supplementation in the general intensive care setting. There have been recent concerns regarding phosphate administration and development of acute kidney injury. We therefore audited our practice of parenteral phosphate administration. We prospectively audited parenteral phosphate administration (20 mmol) in 58 adult patients in a general intensive care unit in a University tertiary referral center. Fifty-eight patients were audited; mean age 57.2 ± 2.0 years, 70.7% male. The median duration of the infusion was 310 min (228-417), and 50% of the patients were on CRRT. 63.8% of patients were hypophosphatemic (phosphate infusion, and serum phosphate increased from 0.79 ± 0.02 to 1.07 ± 0.03 mmol/L, P 1.45 mmol/L). There was no correlation between the change in serum phosphate and the pre-infusion phosphate. Although there were no significant changes in serum urea, creatinine or other electrolytes, arterial ionized calcium fell from 1.15 ± 0.01 to 1.13 ± 0.01 mmol/L, P phosphate did not appear to adversely affect renal function and corrected hypophosphatemia in 67.7% of cases, we found that around 33% of patients who were given parenteral phosphate were not hypophosphatemic, and that the fall in ionized calcium raises the possibility of the formation of calcium-phosphate complexes and potential for soft tissue calcium deposition.

  20. Phosphate removal using sludge from fuller's earth production.

    Science.gov (United States)

    Moon, Yong Hee; Kim, Jae Gon; Ahn, Joo Sung; Lee, Gyoo Ho; Moon, Hi-Soo

    2007-05-08

    This study assesses the phosphate removal capacity and mechanism of precipitation or adsorption from aqueous solutions in batch experiments by an industrial sludge containing gypsum (CaSO(4).2H(2)O) obtained as a by-product from a fuller's earth process. The potential capacity for phosphate removal was tested using various solution concentrations, pH values, reaction times, and amount of sludge. The maximum phosphate adsorption capacity calculated using the Langmuir equation was 2.0 g kg(-1). The pH for the maximum adsorption by the sludge was neutral to alkaline (pH 7-12). Over 99% of phosphate was removed from a phosphate solution of 30 mg L(-1) using 0.15 g of sludge in a 9-h reaction. Sulfate (SO(4)(2-)) concentration increased with increasing initial phosphate concentration, possibly because of dissolution of gypsum and adsorption of both sulfate and phosphate. At high phosphate concentration (>1000 mg L(-1)), relative constant concentration of Ca(2+) was not consistent with adsorption of the most important phosphate removal mechanism. Results suggest that precipitation of calcium phosphate is principally responsible for phosphate removal under its high concentration. Agglomerated precipitate in the reaction sludge was observed by SEM and identified as brushite (CaHPO(4).2H(2)O) by XRD, FT-IR, and DTA. Based on thermodynamic considerations, it is suggested that the brushite will readily transform to more stable phases, such as hydroxyapatite (Ca(5)(PO(4))(3).OH).

  1. 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.

  2. Odontoblast phosphate and calcium transport in dentinogenesis.

    Science.gov (United States)

    Lundquist, Patrik

    2002-01-01

    It has been suggested that odontoblasts are instrumental in translocating Ca2+ and inorganic phosphate (Pi) ions during the mineralization of dentin. The aim of this thesis was, therefore, to study the expression of components of the transcellular ion transport system, Na+/Ca2+ exchangers and Na(+)-Pi contransporters, in odontoblastic and osteoblastic cells. Their activity was assayed in osteoblast-like cells and in the recently developed MRPC-1 odontoblast-like cell line. To assess the relationship between ion transport and mineralization, Ca2+ and Pi uptake activities were determined in mineralizing cultures of MRPC-1 cells. Osteoblastic and odontoblastic cells showed an identical expression pattern of Na+/Ca2+ exchanger splice-variants, NCX1.3, NCX1.7 and NCX1.10, derived from the NCX1 gene, while NCX2 was not expressed. The cells showed a high sodium-dependent calcium extrusion activity. Regarding Na(+)-Pi cotransporter expression, Glvr-1, Ram-1 and the two high capacity cotransporters Npt-2a and Npt-2b were found to be expressed in odontoblasts and MRPC-1 cells. Osteoblast-like cells differed from this in expressing the Npt-1 but not the Ram-1 gene but were otherwise identical to the odontoblastic cells. Odontoblast-like cells exhibited almost twice the sodium-dependent Pi uptake activity of osteoblast-like cells. The presence of NaPi-2a and NaPi-2b, gene products of Npt-2a and Npt-2b, was verified in vivo by immunohistochemistry on mouse teeth. Both cotransporters could be detected in fully differentiated, polarized odontoblasts but not in preodontoblasts prior to dentin formation. Both cotransporters were detected in adjacent bone and in ameloblasts. Studying ion uptake in mineralizing MRPC-1 cultures, large changes were detected concomitant with the onset of mineral formation, when phosphate uptake increased by 400% while calcium uptake started to decline. The increase in Pi uptake was found to be due to activation of the NaPi-2a cotransporter. MRPC-1 cells

  3. Radiological investigation of phosphate fertilizers: Leaching studies.

    Science.gov (United States)

    Hegedűs, Miklós; Tóth-Bodrogi, Edit; Németh, Szabolcs; Somlai, János; Kovács, Tibor

    2017-07-01

    The raw materials of the phosphate fertilizer industry are the various apatite minerals. Some of these have high levels of natural radionuclides, and thus phosphate fertilizers contain significant amounts of U-238, K-40 and Ra-226. These can leach out of the fertilizers used in large quantities for resupplying essential nutrients in the soil and can then enter the food chain through plants, thereby increasing the internal dose of the affected population. In the current study, the radiological risk of eight commercially available phosphate fertilizers (superphosphate, NPK, PK) and their leaching behaviours were investigated using different techniques (gamma and alpha spectrometry), and the dose contributions of using these fertilizers were estimated. To characterize the leaching behaviour, two leaching procedures were applied and compared -the MSZ 21470-50 (Hungarian standard) and the Tessier five-step sequential extraction method. Based on the evaluation of the gamma-spectra, it is found that the level of Th-232 in the samples was low (max.7 ± 6 Bq kg(-1)), the average Ra-226 activity concentration was 309 ± 39 Bq kg(-1) (min. 10 ± 8 Bq kg(-1), max. 570 ± 46 Bq kg(-1)), while the K-40 concentrations (average 3139 ± 188 Bq kg(-1), min. 51 ± 36 Bq kg(-1)) could be as high as 7057 ± 427 Bq kg(-1). The high K-40 can be explained by reference to the composition of the investigated fertilizers (NPK, PK). U concentrations were between 15 and 361 Bq kg(-1), with the average of 254 Bq kg(-1), measured using alpha spectrometry. The good correlation between P2O5 content and radioactivity reported previously is not found in our data. The leaching studies reveal that the mobility of the fertilizer's uranium content is greatly influenced by the parameters of the leaching methods. The availability of U to water ranged between 3 and 28 m/m%, while the Lakanen-Erviö solution mobilized between 10 and 100% of the U content. Copyright © 2016

  4. Surface chemistry studies of phosphate glasses

    Science.gov (United States)

    Barnes, Amy Suzanne

    This research examined the surface of an undoped and rare-earth doped sodium alumino metaphosphate glass after fracture or surface finishing and subsequent exposure to humid and aqueous environments. In addition, the adsorption of aminopropyl triethoxysilane (APS), and the dominant parameters controlling the structure of the deposited film, were studied. Typically, commercial glasses must be cut and polished into optical components for engineering applications. This process involves a series of aqueous treatments in both acidic and basic media. The experiments performed here on aluminophosphate glass showed that this results in dissolution, surface composition changes (depletion of Na) and surface pitting. In both alkaline detergent and acid etching solution, dissolution at a rate of approximately 4 x 10 -3 mol/m2/hr (0.2 mum/hr) occurs along with a drastic alteration of the surface morphology. When exposed to an environment of elevated humidity and temperature for an extended period of time, this aluminophosphate glass was observed to break down, forming a soluble phosphate gel that dissolves away from the surface. Simultaneously, the surface became enriched in silica, a trace contaminant in the glass, which eventually precipitated and coalesced into a dendritic pattern that covered the surface. The freshly powdered phosphate glass was found to contain surface hydroxyls weakly associated with one another, and some bound by a stronger hydrogen bond, likely to adjacent non-bridging oxygens. Most of these hydroxyls could be desorbed upon heating above the glass transition temperature to leave only a small concentration of weakly associated hydroxyls and free hydroxyls on the surface. The characterization of hydroxyls and water on the phosphate glass surface was used to understand the adsorption of aminopropyl tri-ethoxysilane (APS) also through the use of in-situ DRIFTS. The concentration of adsorbed APS was found to be independent of solution pH, but the measured

  5. 21 CFR 520.1804 - Piperazine phosphate capsules.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Piperazine phosphate capsules. 520.1804 Section 520.1804 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... phosphate capsules. (a) Specifications. Each capsule contains 120, 300, or 600 milligrams of piperazine...

  6. Biotemplate synthesis of monodispersed iron phosphate hollow microspheres.

    Science.gov (United States)

    Cao, Feng; Li, Dongxu

    2010-03-01

    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 degrees 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.

  7. 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 carbohydrate-bindi

  8. 21 CFR 522.1244 - Levamisole phosphate injection.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Levamisole phosphate injection. 522.1244 Section 522.1244 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1244 Levamisole phosphate injection....

  9. 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.

  10. Ecological aspects of the biological phosphate removal from waste waters.

    NARCIS (Netherlands)

    Appeldoorn, K.J.

    1993-01-01

    Phosphate emission into surface waters can be reduced by treating sewage in wastewater treatment plants which are run alternately anaerobic and aerobic. Under these conditions, sludge in wastewater treatment plants becomes enriched with polyphosphate accumulating bacteria. Phosphate is released by t

  11. A kinetic study of precipitation from supersaturated calcium phosphate solutions

    NARCIS (Netherlands)

    Kemenade, M.J.J.M. van; Bruyn, P.L. de

    The formation of three different crystalline calcium phosphates (DCPD, OCP, HAP) and an amorphous calcium phosphate was studied as a function of pH and supersaturation. Under the experimental conditions the formation of HAP is always found to be preceded by one or more precursors in a sequence that

  12. 75 FR 42783 - Certain Potassium Phosphate Salts From China

    Science.gov (United States)

    2010-07-22

    ... Phosphate Salts from China: Determinations, 74 FR 61173, November 23, 2009. The Commission transmitted its..., 75 FR 16509). The hearing was held in Washington, DC, on June 2, 2010, and all persons who requested... COMMISSION Certain Potassium Phosphate Salts From China Determinations On the basis of the record...

  13. Phosphate Sorption in Water by Several cationic Polyer flocculants

    Science.gov (United States)

    Although inorganic phosphate is an essential plant nutrient, elevated levels in surface waters may lead to adverse effects in the environment. These effects are attributed to runoff from rain or irrigation events that may cause the sorbed phosphate to move away from the application sites and move i...

  14. 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, o

  15. 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).

  16. 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.

  17. Phosphate inhibition on thermophilic acetoclastic methanogens: a warning

    NARCIS (Netherlands)

    Paulo, P.L.; Santos, dos A.B.; Ide, C.N.; Lettinga, G.

    2005-01-01

    The inhibitory effect of phosphate on acetoclastic-methanogens was investigated for three different thermophilic (55 degrees C) anaerobic consortia. When 70 mM of phosphate was tested, acetoclastic methanogens was completely inhibited in "Eerbeek" sludge which is dominated by Methanosaeta-like metha

  18. 40 CFR 721.643 - Ethoxylated alcohol, phosphated, amine salt.

    Science.gov (United States)

    2010-07-01

    ... salt. 721.643 Section 721.643 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.643 Ethoxylated alcohol, phosphated, amine salt. (a) Chemical substance... alcohol, phosphated, amine salt (PMN P-96-1478) is subject to reporting under this section for the...

  19. 40 CFR 721.5970 - Phosphated polyarylphenol ethoxylate, potassium salt.

    Science.gov (United States)

    2010-07-01

    ..., potassium salt. 721.5970 Section 721.5970 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5970 Phosphated polyarylphenol ethoxylate, potassium salt. (a) Chemical... as phosphated polyarylphenol ethoxylate, potassium salt (PMN P-93-1222) is subject to reporting under...

  20. Structure of RNA 3'-phosphate cyclase bound to substrate RNA.

    Science.gov (United States)

    Desai, Kevin K; Bingman, Craig A; Cheng, Chin L; Phillips, George N; Raines, Ronald T

    2014-10-01

    RNA 3'-phosphate cyclase (RtcA) catalyzes the ATP-dependent cyclization of a 3'-phosphate to form a 2',3'-cyclic phosphate at RNA termini. Cyclization proceeds through RtcA-AMP and RNA(3')pp(5')A covalent intermediates, which are analogous to intermediates formed during catalysis by the tRNA ligase RtcB. Here we present a crystal structure of Pyrococcus horikoshii RtcA in complex with a 3'-phosphate terminated RNA and adenosine in the AMP-binding pocket. Our data reveal that RtcA recognizes substrate RNA by ensuring that the terminal 3'-phosphate makes a large contribution to RNA binding. Furthermore, the RNA 3'-phosphate is poised for in-line attack on the P-N bond that links the phosphorous atom of AMP to N(ε) of His307. Thus, we provide the first insights into RNA 3'-phosphate termini recognition and the mechanism of 3'-phosphate activation by an Rtc enzyme.

  1. 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, o

  2. 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…

  3. Some remarks regarding the manometric determination of pyridoxal phosphate

    NARCIS (Netherlands)

    Donkerlo, Th.W.

    1964-01-01

    In the manometric determination of pyridoxal phosphate (Gunsalus And Smith) continuous careful protection of the solutions from light is required. Stock solutions can be kept for at least one month if stored in the dark. Pyridoxal phosphate added to alkaline extracts of myocardial tissue of rats co

  4. Sodium-dependent phosphate transporters in osteoclast differentiation and function.

    Directory of Open Access Journals (Sweden)

    Giuseppe Albano

    Full Text Available Osteoclasts are multinucleated bone degrading cells. Phosphate is an important constituent of mineralized bone and released in significant quantities during bone resorption. Molecular contributors to phosphate transport during the resorptive activity of osteoclasts have been controversially discussed. This study aimed at deciphering the role of sodium-dependent phosphate transporters during osteoclast differentiation and bone resorption. Our studies reveal RANKL-induced differential expression of sodium-dependent phosphate transport protein IIa (NaPi-IIa transcript and protein during osteoclast development, but no expression of the closely related NaPi-IIb and NaPi-IIc SLC34 family isoforms. In vitro studies employing NaPi-IIa-deficient osteoclast precursors and mature osteoclasts reveal that NaPi-IIa is dispensable for bone resorption and osteoclast differentiation. These results are supported by the analysis of structural bone parameters by high-resolution microcomputed tomography that yielded no differences between adult NaPi-IIa WT and KO mice. By contrast, both type III sodium-dependent phosphate transporters Pit-1 and Pit-2 were abundantly expressed throughout osteoclast differentiation, indicating that they are the relevant sodium-dependent phosphate transporters in osteoclasts and osteoclast precursors. We conclude that phosphate transporters of the SLC34 family have no role in osteoclast differentiation and function and propose that Pit-dependent phosphate transport could be pivotal for bone resorption and should be addressed in further studies.

  5. 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.

  6. The Pentose Phosphate Pathway in Parasitic Trypanosomatids.

    Science.gov (United States)

    Kovářová, Julie; Barrett, Michael P

    2016-08-01

    Parasitic trypanosomatids cause important diseases. Dissecting the biochemistry of these organisms offers a means of discovering targets against which inhibitors may be designed and developed as drugs. The pentose phosphate pathway is a key route of glucose metabolism in most organisms, providing NADPH for use as a cellular reductant and various carbohydrate intermediates used in cellular metabolism. The pathway and its enzymes have been studied in Trypanosoma brucei, Trypanosoma cruzi, and various Leishmania species. Its functions in these parasites are becoming clear. Some enzymes of the pathway are essential to the parasites and have structural features distinguishing them from their mammalian counterparts, and this has stimulated several programs of inhibitor discovery with a view to targeting the pathway with new drugs.

  7. Thermal Decomposition of Nitrated Tributyl Phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Paddleford, D.F. [Westinghouse Savannah River Company, Aiken, SC (United States); Hou, Y.; Barefield, E.K.; Tedder, D.W.; Abdel-Khalik, S.I. [Georgia Institute of Technology, GA (United States)

    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.

  8. Roles of sphingosine 1-phosphate on tumorigenesis

    Institute of Scientific and Technical Information of China (English)

    Hsinyu; Lee

    2011-01-01

    Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid with a variety of biological activities.It is generated from the conversion of ceramide to sphingosine by ceramidase and the subsequent conversion of sphingosine to S1P,which is catalyzed by sphingosine kinases.Through increasing its intracellular levels by sphingolipid metabolism and binding to its cell surface receptors,S1P regulates several physiological and pathological processes,including cell proliferation,migration,angiogenesis and autophagy.These processes are responsible for tumor growth,metastasis and invasion and promote tumor survival.Since ceramide and S1P have distinct functions in regulating in cell fate decision,the balance between the ceramide/sphingosine/S1P rheostat becomes a potent therapeutic target for cancer cells.Herein,we summarize our current understanding of S1P signaling on tumorigenesis and its potential as a target for cancer therapy.

  9. Molecular regulators of phosphate homeostasis in plants.

    Science.gov (United States)

    Lin, Wei-Yi; Lin, Shu-I; Chiou, Tzyy-Jen

    2009-01-01

    An appropriate cellular phosphate (Pi) concentration is indispensable for essential physiological and biochemical processes. To maintain cellular Pi homeostasis, plants have developed a series of adaptive responses to facilitate external Pi acquisition and to limit Pi consumption and to adjust Pi recycling internally when the Pi supply is inadequate. Over the past decade, significant progress has been made toward understanding such regulation at the molecular level. In this review, the focus is on the molecular regulators that mediate cellular Pi concentrations. The regulators are introduced and organized according to their original identification procedures, by the forward genetic approach of mutant screening or by reverse genetic analysis. These genes are involved in Pi uptake, allocation or remobilization or are upstream regulators, such as transcriptional factors or signalling molecules. In the future, integration of current knowledge and exploration of new technology is expected to offer new insights into molecular mechanisms that maintain Pi homeostasis.

  10. Improving the specifications of Syrian raw phosphate by thermal treatment

    Directory of Open Access Journals (Sweden)

    Abdullah Watti

    2016-09-01

    In this research we treated the Syrian raw phosphate by thermal way in order to: (1 Enriching of studied Syrian raw phosphate that contains proportions of 28.60% of phosphorus pentoxide P2O5, 6.12% of carbonate, which we got after treatment at 850 °C for 30 min on a phosphate containing proportion of 33.95% of phosphorus pentoxide P2O5, small amount of carbonate 0.75% and almost free of organic materials. (2 Preparing phosphate fertilizer by thermal treatment in the presence of sodium carbonate, where it was found that the best conditions are adding 40% of sodium carbonate by weight of phosphate ore; temperature 1100 °C; time 120 min.

  11. Injectable bioactive calcium-magnesium phosphate cement for bone regeneration.

    Science.gov (United States)

    Wu, Fan; Su, Jiacan; Wei, Jie; Guo, Han; Liu, Changsheng

    2008-12-01

    Novel injectable and degradable calcium-magnesium phosphate cement (CMPC) with rapid-setting characteristic was developed by the introduction of magnesium phosphate cement (MPC) into calcium phosphate cement (CPC). The calcium-magnesium phosphate cement prepared under the optimum P/L ratio exhibited good injectability and desired workability. It could set within 10 min at 37 degrees C in 100% relative humidity and the compressive strength could reach 47 MPa after setting for 48 h, indicating that the prepared cement has relatively high initial mechanical strength. The results of in vitro degradation experiments demonstrated the good degradability of the injectable CMPC, and its degradation rate occurred significantly faster than that of pure CPC in simulated body fluid (SBF) solution. It can be concluded that the novel injectable calcium-magnesium phosphate cement is highly promising for a wide variety of clinical applications, especially for the development of minimally invasive techniques.

  12. Determination of inorganic phosphate by electroanalytical methods: a review.

    Science.gov (United States)

    Berchmans, Sheela; Issa, Touma B; Singh, Pritam

    2012-06-01

    Determination of inorganic phosphate is of very high importance in environmental and health care applications. Hence knowledge of suitable analytical techniques available for phosphate sensing for different applications becomes essential. Electrochemical methods for determining inorganic phosphate have several advantages over other common techniques, including detection selectivity, stability and relative environmental insensitivity of electroactive labels. The different electrochemical sensing strategies adopted for the determination of phosphate using selective ionophores are discussed in this review. The various sensing strategies are classified based on the electrochemical detection techniques used viz., potentiometry, voltammetry, amperometry, unconventional electrochemical methods etc., The enzymatic sensing of phosphate coupled with electrochemical detection is also included. Various electroanalytical methods available in the literature are assessed for their merits in terms of selectivity, simplicity, miniaturisation, adaptability and suitability for field measurements.

  13. Comparative sorption properties of metal(III) phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa, S.; Naeem, A.; Murtaza, S.; Rehana, N.; Samad, H.Y.

    1999-12-01

    Sorption behavior of metal(III) phosphates toward Zn{sup 2+} was investigated using different concentrations, pHs, and temperatures. Ion exchange between protons from the surface and metal cations from solutions was found to be responsible for metal sorption by metal(III) phosphates. Dissociation constants of metal(III) phosphates and binding constants of the Zn{sup 2+} with metal(III) phosphates were determined using Henderson-Hasselbach and modified Langmuir equations, respectively. The sorption process in all the three metal phosphates was found to be endothermic in nature while the dissociation process was observed to be endothermic in AlPO{sub 4} and FePO{sub 4} and exothermic in CrPO{sub 4}.

  14. CE-MS of antihistamines using nonvolatile phosphate buffer.

    Science.gov (United States)

    Chien, Chiu-Tang; Li, Fu-An; Huang, Ju-Li; Her, Guor-Rong

    2007-05-01

    Antihistamines were analyzed by CE-ESI-MS using phosphate buffer. The separation was performed in an acidic environment so that phosphate ions had a net velocity flowing toward the inlet reservoir instead of the ESI source. To further reduce the effect of ion suppression, the sodium ion in sodium phosphate was replaced with an ammonium ion. Furthermore, with the combination of reducing the concentration of acid added to the sheath liquid and the use of a low-flow interface, phosphoric acid could be added to the sheath liquid. Because of the use of the same counterion (phosphate ion) in running buffer and in sheath liquid, the separation integrity (resolution, elution order, and peak shape) was preserved. In addition, ion suppression was also greatly alleviated because a minimal amount of phosphate flowed into the ESI source.

  15. Cathodic phosphate coating containing nano zinc particles on magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A technology for preparation of a cathodic phosphate coating mainly containing nano metallic zinc particles and phosphate compounds on magnesium alloy was developed.The influence of cathodic current density on the microstructure of the cathodic phosphate coating Was investigated.The results show that the crystals of the coating are finer and the microstructures of the outer surface of the coatings are zigzag at the cathodic density of 0.2-0.5 A/dm2.The content of nano metallic zinc particles in the coating decreases with the increase of the thickness of the coatings and tends to be zero when the coating thickness is 4.14 μm.The cathodic phosphate coating was applied to be a transition coating for improving the adhesion between the paints and the magnesium alloys.The formation mechanism of the cathodic phosphate coating was investigated as well.

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

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Wang; Jiang, Ji Zhi; Yang, Yang; Yan, Zhao Chun; Yan, Wang Xiao [China Building Materials Academy, Beijing (China); He, Shui Zhong [Wuhan University of Technology, Wuhan (China)

    2016-03-15

    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.

  17. Phytate (Inositol Hexakisphosphate) in Soil and Phosphate Acquisition from Inositol Phosphates by Higher Plants. A Review

    OpenAIRE

    2015-01-01

    Phosphate (P) fixation to the soil solid phase is considered to be important for P availability and is often attributed to the strong binding of orthophosphate anion species. However, the fixation and subsequent immobilization of inositolhexa and pentaphosphate isomers (phytate) in soil is often much stronger than that of the orthosphate anion species. The result is that phytate is a main organic P form in soil and the dominating form of identifiable organic P. The reasons for the accumulatio...

  18. Role of phosphate solubilizing bacteria on rock phosphate solubility and growth of aerobic rice.

    Science.gov (United States)

    Panhwar, Q A; Radziah, O; Zaharah, A R; Sariah, M; Razi, I Mohd

    2011-09-01

    Use of phosphate-solubilizing bacteria (PSB) as inoculants has concurrently increased phosphorous uptake in plants and improved yields in several crop species. The ability of PSB to improve growth of aerobic rice (Oryza sativa L.) through enhanced phosphorus (P) uptake from Christmas island rock phosphate (RP) was studied in glasshouse experiments. Two isolated PSB strains; Bacillus spp. PSB9 and PSB16, were evaluated with RP treatments at 0, 30 and 60 kg ha(-1). Surface sterilized seeds of aerobic rice were planted in plastic pots containing 3 kg soil and the effect of treatments incorporated at planting were observed over 60 days of growth. The isolated PSB strains (PSB9 and PSB16) solubilized significantly high amounts of P (20.05-24.08 mg kg(-1)) compared to non-inoculated (19-23.10 mg kg(-1)) treatments. Significantly higher P solubilization (24.08 mg kg(-1)) and plant P uptake (5.31 mg plant(-1)) was observed with the PSB16 strain at the highest P level of 60 kg ha(-1). The higher amounts of soluble P in the soil solution increased P uptake in plants and resulted in higher plant biomass (21.48 g plant(-1)). PSB strains also increased plant height (80 cm) and improved root morphology in aerobic rice. The results showed that inoculation of aerobic rice with PSB improved phosphate solubilizing activity of incorporated RP.

  19. Osteoregenerative capacities of dicalcium phosphate-rich calcium phosphate bone cement.

    Science.gov (United States)

    Ko, Chia-Ling; Chen, Jian-Chih; Tien, Yin-Chun; Hung, Chun-Cheng; Wang, Jen-Chyan; Chen, Wen-Cheng

    2015-01-01

    Calcium phosphate cement (CPC) is a widely used bone substitute. However, CPC application is limited by poor bioresorption, which is attributed to apatite, the stable product. This study aims to systematically survey the biological performance of dicalcium phosphate (DCP)-rich CPC. DCP-rich CPC exhibited a twofold, surface-modified DCP anhydrous (DCPA)-to-tetracalcium phosphate (TTCP) molar ratio, whereas conventional CPC (c-CPC) showed a onefold, surface unmodified DCPA-to-TTCP molar ratio. Cell adhesion, morphology, viability, and alkaline phosphatase (ALP) activity in the two CPCs were examined with bone cell progenitor D1 cultured in vitro. Microcomputed tomography and histological observation were conducted after CPC implantation in vivo to analyze the residual implant ratio and new bone formation rate. D1 cells cultured on DCP-rich CPC surfaces exhibited higher cell viability, ALP activity, and ALP quantity than c-CPC. Histological evaluation indicated that DCP-rich CPC showed lesser residual implant and higher new bone formation rate than c-CPC. Therefore, DCP-rich CPC can improve bioresorption. The newly developed DCP-rich CPC exhibited potential therapeutic applications for bone reconstruction.

  20. Multiple independent fusions of glucose-6-phosphate dehydrogenase with enzymes in the pentose phosphate pathway.

    Directory of Open Access Journals (Sweden)

    Nicholas A Stover

    Full Text Available Fusions of the first two enzymes in the pentose phosphate pathway, glucose-6-phosphate dehydrogenase (G6PD and 6-phosphogluconolactonase (6PGL, have been previously described in two distant clades, chordates and species of the malarial parasite Plasmodium. We have analyzed genome and expressed sequence data from a variety of organisms to identify the origins of these gene fusion events. Based on the orientation of the domains and range of species in which homologs can be found, the fusions appear to have occurred independently, near the base of the metazoan and apicomplexan lineages. Only one of the two metazoan paralogs of G6PD is fused, showing that the fusion occurred after a duplication event, which we have traced back to an ancestor of choanoflagellates and metazoans. The Plasmodium genes are known to contain a functionally important insertion that is not seen in the other apicomplexan fusions, highlighting this as a unique characteristic of this group. Surprisingly, our search revealed two additional fusion events, one that combined 6PGL and G6PD in an ancestor of the protozoan parasites Trichomonas and Giardia, and another fusing G6PD with phosphogluconate dehydrogenase (6PGD in a species of diatoms. This study extends the range of species known to contain fusions in the pentose phosphate pathway to many new medically and economically important organisms.

  1. Penggunaan batuan fosfat NDCP (natural defluorinated calcium phosphate sebagai pengganti dicalcium phosphate dalam ransom ayam broiler

    Directory of Open Access Journals (Sweden)

    Arnold P. Sinurat

    1995-08-01

    Full Text Available An experiment was conducted to study the utilization of local rock phosphate or natural defluorinated calcium phosphate (NDCP as phosphorus source for broilers by using the imported dicalcium phosphate (DCP as a reference. The study was designed by formulating 6 experimental diets which consist of 2 phosphorus sources (DCP dan NDCP and 3 dietary total P levels (0 .55 ; 0.65 and 0 .75%. Each diet was fed to 60 chickens (10 replicates with 6 birds each from three day old to 6 weeks of age. Parameters observed were feed consumption, body weight gain, mortality, Ca and P retention, and ash content of tibia bones. Results showed that dietary phosphorus levels (0.55 to 0.75% did not significantly affect body weight gain, feed consumption, and mortalities. However, better feed conversion ratio was obtained when dietary phosphorus level was 0.55%. The NDCP treated birds could significantly gain heavier weight compared with those received DCP, although this improvement was also followed by an increase in the feed consumption. The relative biological value of phosphorus in NDCP was 101 `7n. It is concluded that NDCP can he used in broilers diet to replace DCP as phosphorus source.

  2. 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...

  3. Two-component signal transduction in Synechocystis sp. PCC 6803 under phosphate limitation: role of acetyl phosphate.

    Science.gov (United States)

    Juntarajumnong, Waraporn; Eaton-Rye, Julian J; Incharoensakdi, Aran

    2007-09-30

    The two-component signal transduction, which typically consists of a histidine kinase and a response regulator, is used by bacterial cells to sense changes in their environment. Previously, the SphS-SphR histidine kinase and response regulator pair of phosphate sensing signal transduction has been identified in Synechocystis sp. PCC 6803. In addition, some response regulators in bacteria have been shown to be cross regulated by low molecular weight phosphorylated compounds in the absence of the cognate histidine kinase. The ability of an endogenous acetyl phosphate to phosphorylate the response regulator, SphR in the absence of the cognate histidine kinase, SphS was therefore tested in Synechocystis sp. PCC 6803. The mutant lacking functional SphS and acetate kinase showed no detectable alkaline phosphatase activity under phosphate-limiting growth conditions. The results suggested that the endogenous acetyl phosphate accumulated inside the mutants could not activate the SphR via phosphorylation. On the other hand, exogenous acetyl phosphate could allow the mutant lacking functional acetate kinase and phosphotransacetylase to grow under phosphate-limiting conditions suggesting the role of acetyl phosphate as an energy source. Reverse transcription PCR demonstrated that the transcripts of acetate kinase and phosphotransacetylase genes in Synechocystis sp. PCC 6803 is upregulated in response to phosphate limitation suggesting the importance of these two enzymes for energy metabolism in Synechocystis cells.

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

    NARCIS (Netherlands)

    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 th

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

    NARCIS (Netherlands)

    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

  6. Metal sulfide and rare-earth phosphate nanostructures and methods of making same

    Science.gov (United States)

    Wong, Stanislaus; Zhang, Fen

    2016-06-28

    The present invention provides a method of producing a crystalline rare earth phosphate nanostructure. The method comprising: providing a rare earth metal precursor solution and providing a phosphate precursor solution; placing a porous membrane between the metal precursor solution and the phosphate precursor solution, wherein metal cations of the metal precursor solution and phosphate ions of the phosphate precursor solution react, thereby producing a crystalline rare earth metal phosphate nanostructure.

  7. Diversity of Phosphate-Dissolving Microorganisms in Corn Rhizosphere

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiao-rong; LIN Qi-mei; LI Bao-guo

    2003-01-01

    Rhizosphere and nonrhizopshere soils were sampled during corn growth. Total, inorganic phosphate-dissolving and lecithin-mineralizing bacteria, fungi and actinomyctes were determined by plate counting method. Generally, the rhizosphere soil contained around 5 to 100 times more of these bacteria and fungi than the non-rhizosphere soil. However, the actinomycetes in the rhizosphere soil were significantly lower than those in the non-rhizosphere soil. The numbers of these microorganisms didnt significantly change during corn growth in the soils. However, the proportion of the phosphate-dissolving microorganisms in the total changed markedly during corn growth. Generally there were much higher percentages of phosphate-dissolving bacteria and phosphate-dissolving fungi in the rhizosphere soil than the nonrhizosphere soil. More than 90% of the fungi in rhizosphere dissolved inorganic phosphate at the seedling period, but this proportion declined to 20 %at the harvesting time. The community of phosphate-dissolving microorganisms also changed during corn growth. Bacillus was dominant in the nonrhizosphere soil. However, in the rhizosphere, Pseudomonas and Enterobacter became predominant. Penicillium and Streptomyces were the main fungi and actinomycetes capable of dissolving phosphate.

  8. Synthesis of aryl phosphates based on pyrimidine and triazine scaffolds.

    Science.gov (United States)

    Courme, Caroline; Gresh, Nohad; Vidal, Michel; Lenoir, Christine; Garbay, Christiane; Florent, Jean-Claude; Bertounesque, Emmanuel

    2010-01-01

    The syntheses of the triazinyl-based bis-aryl phosphates 2 and 3, and of the aminopyrimidyl-based aryl phosphate 4 are described. Each compound contains a diaryl ether-phosphate structural motif. The synthetic route to bis-aryl phosphates 2 and 3 consisted in two nucleophilic substitution reactions with amines from cyanuric chloride, followed by a Suzuki coupling with the resulting 2,4-diamino-6-chloro-1,3,5-triazine derivative 12 to introduce the diaryl ether functionality. Aryl phosphate 4 was obtained via condensation of aryl guanidine 34 with aryloxyphenyl butenone 31. These de novo-designed aryl phosphates were evaluated as potential inhibitors of the Grb2-SH2 domain using an ELISA assay. The water-soluble sodium salt 26 of 3 gave an IC(50) value in the high micromolar range. Molecular modeling studies were subsequently performed upon modifying the 1,3,5-trisubstituted triazine scaffold of 3. Non-phosphate derivatives encompassing cyclopropane, pyrrole, keto-acid, and IZD fragments were thus step-wise designed and their Grb2-SH2 complexes were modeled by molecular dynamics. Some derivatives gave rise to an enriched pattern of H-bonds and cation-pi interactions with Grb2-SH2.

  9. Synthesis of Nano-sized Boehmites for Optimum Phosphate Sorption

    DEFF Research Database (Denmark)

    Watanabe, Yujiro; Kasama, Takeshi; Fukushi, Keisuke;

    2011-01-01

    Nano-sized boehmites with different crystallinity were synthesized at the temperature range of 25 to 200°C in order to produce phosphate absorbents with high capacity. The physicochemical property of boehmites was depended on the synthesis temperature: the particle size was increased and the surf......Nano-sized boehmites with different crystallinity were synthesized at the temperature range of 25 to 200°C in order to produce phosphate absorbents with high capacity. The physicochemical property of boehmites was depended on the synthesis temperature: the particle size was increased...... and the surface area showed the maximum for the boehmite at 50°C. The phosphate sorptions into boehmites were analyzed at room temperature in the phosphoric acid solutions as a model of wastewater at the concentration of 0.1 to 3.0 mmol l-1 and the pH of 3 to 7. The boehmite synthesized at 50°C exhibited...... the highest amount of phosphate sorption (1.73 mmol g-1 at pH 3.3) compared with Al-bearing materials. The reaction mechanism during phosphate sorption was described by the anion exchange reaction between phosphate ions in sodium phosphate solution and hydroxide ions on boehmite surfaces. Therefore...

  10. Plant Growth Promotion Induced by Phosphate Solubilizing Endophytic Pseudomonas Isolates

    Directory of Open Access Journals (Sweden)

    Nicholas eOtieno

    2015-07-01

    Full Text Available The use of plant growth promoting bacterial inoculants as live microbial biofertilisers provides a promising alternative to chemical fertilisers and pesticides. Inorganic phosphate solubilisation is one of the major mechanisms of plant growth promotion by plant associated bacteria. This involves bacteria releasing organic acids into the soil which solubilise the phosphate complexes converting them into ortho-phosphate which is available for plant up-take and utilisation. The study presented here describes the ability of endophytic bacterial isolates to produce gluconic acid, solubilise insoluble phosphate and stimulate the growth of Pea plants (Pisum sativum. This study also describes the genetic systems within three of these endophyte isolates thought to be responsible for their effective phosphate solubilising abilities. The results showed that many of the endophytic isolates produced gluconic acid (14-169 mM and have moderate to high phosphate solubilisation capacities (~ 400-1300 mg L-1. When inoculated to Pea plants grown in sand/soil under soluble phosphate limiting conditions, the endophyte isolates that produced medium to high levels of gluconic acid also displayed enhanced plant growth promotion effects.

  11. Engineering Potato Starch with a Higher Phosphate Content

    Science.gov (United States)

    Xu, Xuan; Huang, Xing-Feng; Visser, Richard G. F.

    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 carbohydrate-binding module and a dual-specificity phosphatase domain, is involved in the dephosphorylation of glycogen. To modify phosphate content and better understand starch (de)phosphorylation 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. PMID:28056069

  12. Phosphate reduction in a hydroxyapatite fluoride removal system

    Science.gov (United States)

    Egner, A.

    2012-12-01

    Fluorosis is a widespread disease that occurs as a result of excess fluoride consumption and can cause severe tooth and bone deformations. To combat fluorosis, several previous studies have examined the potential to replace traditional bone char filters with synthetic hydroxyapatite. Calcite particles with a synthetic hydroxyapatite coating have been shown to effectively removed fluoride, yet the low-cost method for forming these particles leaves high amounts of phosphate both in synthesis waste-water and in filter effluent. High phosphate in filter effluent is problematic because consumption of extremely high phosphate can leach calcium from bones, further exacerbating the fluoride effect. This study examines ways of reducing and reusing waste. In particular, a method of fluoride removal is explored in which fluorapatite coatings may be formed directly. In preliminary studies, batches of 4.1g of Florida limestone (<710 μm) were equilibrated with 100 mL of 10ppm fluoride. In a control batch containing lime but no added phosphate, 14% treatment was achieved, but with added phosphate, 100% treatment was achieved in all batches. Batches with lower levels of phosphate took longer to reach 100% treatment, ranging from less than 24 hours in the highest phosphate batches to approximately 42 hours in the lowest batches. The lower levels tested were well within reasonable levels for drinking water and reached 0ppm fluoride in 42 hours or less.

  13. Serum electrolyte shifts following administration of sodium phosphates enema.

    Science.gov (United States)

    Jacobson, Robert M; Peery, Jessica; Thompson, William O; Kanapka, Joseph A; Caswell, Michael

    2010-01-01

    The misuse of sodium phosphates enemas has resulted in reports of potentially severe metabolic and hemodynamic disturbances. Despite their long availability, these products have not been fully characterized pharmacokinetically. This trial sought to evaluate changes in the metabolic and hemodynamic parameters following the administration of one of two standard sodium phosphates enemas. Enema Casen (250 ml) is available only in Spain, and Fleet Enema (133 ml) is available in 66 countries in six continents of the world. These changes were correlated with scientific literature reports of hyperphosphatemia following phosphate enema use. Forty-five adult participants aged 50 years or older enrolled in the trial. Twenty-five participants were given one Enema Casen, whereas 20 participants received one Fleet Enema. Blood pressure, pulse, and serum chemistries were evaluated at screening; baseline; and 10, 60, and 120 minutes after receiving the enema. Each participant had a bowel movement within 10 minutes of receiving his enema. Asymptomatic, transient hyperphosphatemia was associated with increase in retention time but not with increase in volume of sodium phosphates enemas. Increased serum phosphate concentration and increased area under the curve of serum phosphate were associated with increased enema retention time. The Enema Casen induced a greater mean AUC of serum sodium concentration than did the Fleet Enema. There were no drug-related adverse events. Transient hyperphosphatemia following the use of sodium phosphates enemas correlates with retention time but not with dose. A scientific literature review of serious adverse events revealed that overdose, concomitant use of oral and rectal sodium phosphates products, and use in a contraindicated patient were associated with sodium phosphates enema and hyperphosphatemia.

  14. Selective separation of phosphate and fluoride from semiconductor wastewater.

    Science.gov (United States)

    Warmadewanthi, B; Liu, J C

    2009-01-01

    Hydrofluoric acid (HF) and phosphoric acid (H(3)PO(4)) are widely used in semiconductor industry for etching and rinsing purposes. Consequently, significant amount of wastewater containing phosphate and fluoride is generated. Selective separation of phosphate and fluoride from the semiconductor wastewater, containing 936 mg/L of fluoride, 118 mg/L of phosphate, 640 mg/L of sulfate, and 26.7 mg/L of ammonia, was studied. Chemical precipitation and flotation reactions were utilized in the two-stage treatment processes. The first-stage reaction involved the addition of magnesium chloride (MgCl(2)) to induce selective precipitation of magnesium phosphate. The optimal condition was pH 10 and molar ratio, [Mg(2 + )]/[(PO(4) (3-))], of 3:1, and 66.2% of phosphate was removed and recovered as bobierrite (Mg(3)(PO(4))(2).8H(2)O). No reaction was found between MgCl(2) and fluoride. Calcium chloride (CaCl(2)) was used in the second-stage reaction to induce precipitation of calcium fluoride and calcium phosphate. The optimum molar ratio, [Ca(2 + )]/[F(-)], was 0.7 at pH 10, and residual fluoride concentration of 10.7 mg/L and phosphate concentration of lower than 0.5 mg/L was obtained. Thermodynamic equilibrium was modeled with PHREEQC and compared with experimental results. Sodium dodecylsulfate (SDS) was an effective collector for subsequent solid-liquid removal via dispersed air flotation (DiAF). The study demonstrated that phosphate can be selectively recovered from the wastewater. Potential benefits include recovery of phosphate for reuse, lower required dosage of calcium for fluoride removal, and less amount of CaF(2) sludge.

  15. Fluorescence sensor for sequential detection of zinc and phosphate ions

    Science.gov (United States)

    An, Miran; Kim, Bo-Yeon; Seo, Hansol; Helal, Aasif; Kim, Hong-Seok

    2016-12-01

    A new, highly selective turn-on fluorescent chemosensor based on 2-(2‧-tosylamidophenyl)thiazole (1) for the detection of zinc and phosphate ions in ethanol was synthesized and characterized. Sensor 1 showed a high selectivity for zinc compared to other cations and sequentially detected hydrogen pyrophosphate and hydrogen phosphate. The fluorescence mechanism can be explained by two different mechanisms: (i) the inhibition of excited-state intramolecular proton transfer (ESIPT) and (ii) chelation-induced enhanced fluorescence by binding with Zn2 +. The sequential detection of phosphate anions was achieved by the quenching and subsequent revival of ESIPT.

  16. 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

  17. Amine-intercalated α-zirconium phosphates as lubricant additives

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Huaping; Dai, Wei [Department of Mechanical Engineering, Texas A& M University, College Station, TX 77843 (United States); Kan, Yuwei; Clearfield, Abraham [Department of Chemistry, Texas A& M University, College Station, TX 77843 (United States); Liang, Hong, E-mail: hliang@tamu.edu [Department of Mechanical Engineering, Texas A& M University, College Station, TX 77843 (United States)

    2015-02-28

    In this study, three types of amines intercalated α-zirconium phosphate nanosheets with different interspaces were synthesized and examined as lubricant additives to a mineral oil. Results from tribological experiments illustrated that these additives improved lubricating performance. Results of rheological experiments showed that the viscosity of the mineral oil was effectively reduced with the addition of α-zirconium phosphate nanosheets. The two-dimensional structure, with larger interspaces, resulting from amine intercalation, exhibited improved effectiveness in reducing viscosity. This study demonstrates that the nanosheet structure of α-zirconium phosphates is effective in friction reduction. The manufacture of lubricants with tailored viscosity is possible by using different intercalators.

  18. Nickel phosphate molecular sieve as electrochemical capacitors material

    Science.gov (United States)

    Yang, Jing-He; Tan, Juan; Ma, Ding

    2014-08-01

    The nickel phosphate molecular sieve VSB-5 as an electrode material for supercapacitors is investigated by cyclic voltammetry (CV) and chronopotentiometry in alkaline media. The VSB-5 shows high specific capacitance and excellent cycling stability. The specific capacitance of VSB-5 is 2740 F g-1 at a current density of 3 A g-1 and there is no significant reduction in Coulombic efficiency after 3000 cycles at 30 A g-1. In comparison with mesoporous nickel phosphate NiPO, porous nickel hydroxide and mesoporous nickel oxide, this remarkable electrochemical performance of VSB-5 will make nickel phosphate material a promising new electrode material for high performance supercapacitors.

  19. Priapism and glucose-6-phosphate dehydrogenase deficiency: An underestimated correlation?

    Directory of Open Access Journals (Sweden)

    Aldo Franco De Rose

    2016-10-01

    Full Text Available Priapism is a rare clinical condition characterized by a persistent erection unrelated to sexual excitement. Often the etiology is idiopathic. Three cases of priapism in glucose-6-phosphate dehydrogenase (G6PD deficiency patients have been described in literature. We present the case of a 39-year-old man with glucose- 6-phosphate dehydrogenase deficiency, who reached out to our department for the arising of a non-ischemic priapism without arteriolacunar fistula. We suggest that the glucose-6-phosphate dehydrogenase deficiency could be an underestimated risk factor for priapism.

  20. Approaches to Computer Modeling of Phosphate Hide-Out.

    Science.gov (United States)

    1984-06-28

    phosphate acts as a buffer to keep pH at a value above which acid corrosion occurs . and below which caustic corrosion becomes significant. Difficulties are...ionization of dihydrogen phosphate : HIPO - + + 1PO, K (B-7) H+ + - £Iao 1/1, (B-8) H , PO4 - + O- - H0 4 + H20 K/Kw (0-9) 19 * Such zero heat...OF STANDARDS-1963-A +. .0 0 0 9t~ - 4 NRL Memorandum Report 5361 4 Approaches to Computer Modeling of Phosphate Hide-Out K. A. S. HARDY AND J. C

  1. Study of Acid Phosphatase in Solubilization of Inorganic Phosphates by Piriformospora indica.

    Science.gov (United States)

    Seshagiri, Swetha; Tallapragada, Padmavathi

    2017-01-02

    Phosphorus is an essential plant macronutrient present in the soil. Only a small portion of phosphorus in soil is taken up by plants and the rest of it becomes unavailable to plants as it is immobilized. Phosphate solubilizing microorganisms play a vital role in converting the insoluble form of phosphates to the soluble form. The present paper reports the solubilization of tricalcium phosphate, rock phosphate, single super phosphate, zinc phosphate and aluminum phosphate by Piriformospora indica with the production of organic acids as well as acid phosphatase. The amount of phosphate released (4.73 mg ml(-1)) and titratable acidity (0.12%) was found to be the highest in the case of single super phosphate as compared to other phosphate sources. High performance liquid chromatography (HPLC) revealed the presence of oxalic acid, lactic acid, citric acid and succinic acid in the media. Highest phosphatase activity was observed with the cell membrane extract of the organism in the presence of zinc phosphate.

  2. [Isolation and identification of a novel phosphate-dissolving strain P21].

    Science.gov (United States)

    Yang, Hui; Fan, Bingquan; Gong, Mingbo; Li, Quanxia

    2008-01-01

    Phosphate-dissolving microorganisms can be applied for better use of insoluble phosphorus as fertilizer., A phosphate-dissolving strain P21 was isolated from soil samples in China. The isolate was identified as Erwinia herbicola var. ananas, based on its 16Sr DNA sequence and physiological characteristics. Its activity was measured in solid media as well as liquid media using different phosphate sources including tricalium phosphate, hydroxyapatite, ferric phosphate, aluminium phosphate, zinc phosphate, and rock phosphates. E. herbicola could strongly dissolve 1206.20 mg tricalium phosphate and 529.67 mg hydroxyapatite in per liter liquid media. The strain showed high phosphate-dissolving ability for rock phosphates from Jinning and Kunyang in Yunnan province, Yaan in Sichuan province and Jinping in Jiangsu province with the capacity of 6.64 mg, 78.46 mg, 67.07 mg and 65.24 mg soluble phosphate respectively per liter medium, whereas the phosphate-dissolving ability to the rest of the eight rock phosphates was weak. According to the experiments, the phosphate-dissolving ability of E. herbicola was specific to different rock phosphates, and phosphate-dissolving ability of E. herbicola was not directly related to pH reduction of liquid media.

  3. Phosphate oxygen isotope ratios as a tracer for sources and cycling of phosphate in North San Francisco Bay, California

    Science.gov (United States)

    McLaughlin, Karen; Kendall, Carol; Silva, Steven R.; Young, Megan; Paytan, Adina

    2006-09-01

    A seasonal analysis assesing variations in the oxygen isotopic composition of dissolved inorganic phosphate (DIP) was conducted in the San Francisco Bay estuarine system, California. Isotopic fractionation of oxygen in DIP (exchange of oxygen between phosphate and environmental water) at surface water temperatures occurs only as a result of enzyme-mediated, biological reactions. Accordingly, if phospate demand is low relative to input and phosphate is not heavily cycled in the ecosystem, the oxygen isotopic composition of DIP (δ18Op) will reflect the isotopic composition of the source of phosphate to the system. Such is the case for the North San Francisco Bay, an anthropogenically impacted estuary with high surface water phosphate concentrations. Variability in the δ18Op in the bay is primarily controlled by mixing of water masses with different δ18Op signatures. The δ18Op values range from 11.4‰ at the Sacramento River to 20.1‰ at the Golden Gate. Deviations from the two-component mixing model for the North Bay reflect additional, local sources of phosphate to the estuary that vary seasonally. Most notably, deviations from the mixing model occur at the confluence of a major river into the bay during periods of high river discharge and near wastewater treatment outlets. These data suggest that δ18Op can be an effective tool for identifying P point sources and understanding phosphate dynamics in estuarine systems.

  4. Phosphate oxygen isotope ratios as a tracer for sources and cycling of phosphate in North San Francisco Bay, California

    Science.gov (United States)

    McLaughlin, K.; Kendall, C.; Silva, S.R.; Young, M.; Paytan, A.

    2006-01-01

    A seasonal analysis assesing variations in the oxygen isotopic composition of dissolved inorganic phosphate (DIP) was conducted in the San Francisco Bay estuarine system, California. Isotopic fractionation of oxygen in DIP (exchange of oxygen between phosphate and environmental water) at surface water temperatures occurs only as a result of enzyme-mediated, biological reactions. Accordingly, if phospate demand is low relative to input and phosphate is not heavily cycled in the ecosystem, the oxygen isotopic composition of DIP (?? 18Op) will reflect the isotopic composition of the source of phosphate to the system. Such is the case for the North San Francisco Bay, an anthropogenically impacted estuary with high surface water phosphate concentrations. Variability in the ?? 18Op in the bay is primarily controlled by mixing of water masses with different ??18Op signatures. The ??18Op values range from 11.4??? at the Sacramento River to 20.1??? at the Golden Gate. Deviations from the two-component mixing model for the North Bay reflect additional, local sources of phosphate to the estuary that vary seasonally. Most notably, deviations from the mixing model occur at the confluence of a major river into the bay during periods of high river discharge and near wastewater treatment outlets. These data suggest that ??18Op can be an effective tool for identifying P point sources and understanding phosphate dynamics in estuarine systems. Copyright 2006 by the American Geophysical Union.

  5. Phosphate Barriers for Immobilization of Uranium Plumes

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Peter C.

    2004-12-01

    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.

  6. Phosphate Barriers for Immobilization of Uranium Plumes

    Energy Technology Data Exchange (ETDEWEB)

    Icenhower, Jonathan P.; Burns, Peter C.

    2005-06-01

    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.

  7. Arsenate and phosphate interaction in Saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    GENG Chun-nu; ZHU Yong-guan

    2006-01-01

    In the present study, arsenate(As(Ⅴ)) and phosphate(P(Ⅴ)) interactions were investigated in growth, uptake and RNA content in yeast(Saccharomyces cerevisiae). Yeast grew slowly with As(Ⅴ) concentrations increasing in the medium. However, the maximal population density was almost the same among different As(Ⅴ) treatments. It was in the late log phase that yeast growth was augmented by low As(Ⅴ), which was maybe due to the fact that methionine metabolism was stressed by vitamin B6 deprivation, so As(Ⅴ)treatments did not affect maximal population density. However, with P (Ⅴ) concentrations increasing, the maximal population density increased. Therefore, the maximal population density was determined by P (Ⅴ) concentrations in the medium but not by As (Ⅴ)concentrations in the medium. Ycf1p(a tonoplast transpor) transports As(GS)3 into the vacuole, but arsenic(As) remaining in the thalli was 1.27% with As(Ⅴ) exposure for 60 h, from which it can be speculated that the percentage of As transported into vacuole should be lower than 1.27%. However, the percentage of As pumped out of cell was 71.49% with As (Ⅴ) exposure for 68 h. Although two pathways (extrusion and sequestration) were involved in As detoxification in yeast, the extrusion pathway played a major role in As detoxification. RNA content was the highest in the early-log phase and was reduced by As(Ⅴ).

  8. Antiferroelectric films of deuterated betaine phosphate

    Science.gov (United States)

    Balashova, E. V.; Krichevtsov, B. B.; Svinarev, F. B.; Zaitseva, N. V.

    2016-07-01

    Thin films of partially deuterated betaine phosphate have been grown by the evaporation on Al2O3(110) and NdGaO3(001) substrates with a preliminarily deposited structure of interdigitated electrodes. The grown films have a polycrystalline block structure with characteristic dimensions of blocks of the order of 0.1-1.5 mm. The degree of deuteration of the films D varies in the range of 20-50%. It has been found that, at the antiferroelectric phase transition temperature T c afe = 100-114 K, the fabricated structures exhibit an anomaly of the electrical capacitance C, which is not accompanied by a change in the dielectric loss tangent tanδ. The strong-signal dielectric response is characterized by the appearance of a ferroelectric nonlinearity at temperatures T > T c afe , which is transformed into an antiferroelectric nonlinearity at T < T c afe . With a further decrease in the temperature, double dielectric hysteresis loops appear in the antiferroelectric phase. The dielectric properties of the films have been described within the framework of the Landau-type thermodynamic model taking into account the biquadratic coupling ξ P 2η2 between the polar order parameter P and the nonpolar order parameter η with a positive coefficient ξ. The E-T phase diagram has been constructed.

  9. Characterization of the mineral phosphate solubilizing activity of Serratia marcescens CTM 50650 isolated from the phosphate mine of Gafsa.

    Science.gov (United States)

    Ben Farhat, Mounira; Farhat, Ameny; Bejar, Wacim; Kammoun, Radhouan; Bouchaala, Kameleddine; Fourati, Amin; Antoun, Hani; Bejar, Samir; Chouayekh, Hichem

    2009-11-01

    The mineral phosphate solubilizing (MPS) ability of a Serratia marcescens strain, namely CTM 50650, isolated from the phosphate mine of Gafsa, was characterized on a chemically defined medium (NBRIP broth). Various insoluble inorganic phosphates, including rock phosphate (RP), calcium phosphate (CaHPO(4)), tri-calcium phosphate (Ca(3)(PO(4))(2)) and hydroxyapatite were tested as sole sources of phosphate for bacterial growth. Solubilization of these phosphates by S. marcescens CTM 50650 was very efficient. Indeed, under optimal conditions, the soluble phosphorus (P) concentration it produced reached 967, 500, 595 and 326 mg/l from CaHPO(4), Ca(3)(PO(4))(2), hydroxyapatite and RP, respectively. Study of the mechanisms involved in the MPS activity of CTM 50650, showed that phosphate solubilization was concomitant with significant drop in pH. HPLC-analysis of culture supernatants revealed the secretion of gluconic acid (GA) resulting from direct oxidation pathway of glucose when the CTM 50650 cells were grown on NBRIP containing glucose as unique carbon source. This was correlated with the simultaneous detection by PCR for the first time in a S. marcescens strain producing GA, of a gene encoding glucose dehydrogenase responsible for GA production, as well as the genes pqqA, B, C and E involved in biosynthesis of its PQQ cofactor. This study is expected to lead to the development of an environmental-friendly process for fertilizer production considering the capacity of S. marcescens CTM 50650 to achieve yields of P extraction up to 75% from the Gafsa RP.

  10. Effects of Soluble Phosphate on Phosphate-Solubilizing Characteristics and Expression of gcd Gene in Pseudomonas frederiksbergensis JW-SD2.

    Science.gov (United States)

    Zeng, Qingwei; Wu, Xiaoqin; Wen, Xinyi

    2016-02-01

    Phosphate-solubilizing bacteria have the ability of solubilizing mineral phosphate in soil and promoting growth of plants, but the activity of phosphate solubilization is influenced by exogenous soluble phosphate. In the present study, the effects of soluble phosphate on the activity of phosphate solubilization, acidification of media, growth, and organic acid secretion of phosphate-solubilizing bacterium Pseudomonas frederiksbergensis JW-SD2 were investigated under six levels of soluble phosphate conditions. The activity of phosphate solubilization decreased with the increase of soluble phosphate concentration, accompanying with the increase of media pH. However, the growth was promoted by adding soluble phosphate. Production of gluconic, tartaric, and oxalic acids by the strain was reduced with the increase of concentration of soluble phosphate, while acetic and pyruvic acids showed a remarkable increase. Gluconic acid predominantly produced by the strain at low levels of soluble phosphate showed that this acid was the most efficient organic acid in phosphate solubilization. Pyrroloquinoline quinone-glucose dehydrogenase gene gcd (pg5SD2) was cloned from the strain, and the expressions of pg5SD2 gene were repressed gradually with the increase of concentration of soluble phosphate. The soluble phosphate regulating the transcription of the gcd gene is speculated to underlie the regulation of the secretion of gluconic acid and subsequently the regulation of the activity of phosphate solubilization. Future research needs to consider a molecular engineering strategy to reduce the sensitivity of PSB strain to soluble phosphate via modification of the regulatory mechanism of gcd gene, which could improve the scope of PSB strains' application.

  11. Formation of hydroxyapatite in hydrogels from tetracalcium phosphate/dicalcium phosphate mixtures.

    Science.gov (United States)

    Sugawara, A; Antonucci, J M; Takagi, S; Chow, L C; Ohashi, M

    1989-03-01

    Apatitic calcium phosphate cements, formed by the ambient reaction of tetracalcium phosphate (TTCP) with dicalcium phosphates (DCP), have been recently reported. H2O or dilute aq. H3PO4 (0.2%) is used as the liquid vehicle for this reaction. The aim of this study was to ascertain if hydroxyapatite (HAp) can form in self-cured hydrogel composites containing TTCP/DCP mixes. The setting times (ST) and diametral tensile strengths (DTS) of these hydrogel composites were also determined. The hydrogels were of two types: (1) vinyl thermosets derived from the copolymerization of HEMA (2-hydroxyethyl methacrylate) and cross-linking monomers, and (2) polyelectrolyte-based hydrogels formed from aq. poly(alkenoic acids), e.g., poly(acrylic acid). Cylindrical specimens 6 mm D x 3 mm H were prepared and stored in H2O for up to 30 days. The HEMA composites were hardened in 7-15 min by free radical initiation (benzoyl peroxide/tertiary aromatic amine). The polyelectrolyte cements were hardened in 6-8 min. After various periods of storage in H2O at 37 degrees C, some of the specimens were examined by X-ray spectroscopy for HAp. HAp formation was not observed in the HEMA composites even after 30 days of H2O storage but was detected in the polyacid cements. The 24-h DTS values of the HEMA composites (14-26 MPa) were higher than those of the polyacid cements (7-12 MPa). Both the H2O content and pH may thus be factors controlling the rate and extent of HAp formation in hydrogel composites containing TTCP/DCP mixtures.

  12. The active centre of rabbit muscle triose phosphate isomerase. The site that is labelled by glycidol phosphate.

    Science.gov (United States)

    Miller, J C; Waley, S G

    1971-06-01

    1. Glycidol (2,3-epoxypropanol) phosphate is a specific irreversible inhibitor of rabbit muscle triose phosphate isomerase (EC 5.3.1.1); the site of attachment has now been studied. 2. The labelled enzyme was digested with pepsin and a modified peptide isolated. The sequence of the peptide is: Ala-Tyr-Glu-Pro-Val-Trp. 3. It is the glutamic acid residue in this peptide that is labelled: the peptide is thus a gamma-glutamyl ester derived from glycerol phosphoric acid. The same site is labelled by a mixture of glycidol and inorganic phosphate. 4. Kinetic and stereochemical features of these reactions are discussed.

  13. Surfactant modified coir pith, an agricultural solid waste as adsorbent for phosphate removal and fertilizer carrier to control phosphate release.

    Science.gov (United States)

    Namasivayam, C; Kumar, M V Suresh

    2005-10-01

    The surface of coir pith, an agricultural solid waste was modified using a cationic surfactant, hexadecyltrimethylammonium bromide (HDTMA) and the modified coir pith was investigated to assess the capacity for the removal of phosphate from aqueous solution. Optimum pH for maximum phosphate adsorption was found to be 4.0. Langmuir and Freundlich isotherms were used to model the adsorption equilibrium data. Kinetic studies showed that the adsorption obeyed second order kinetics. Thermodynamic parameters were evaluated and the overall adsorption process was spontaneous and endothermic. Effect of coexisting anions has also been studied. The feasibility of using spent adsorbent as fertilizer carrier to control phosphate release was also investigated.

  14. Phosphate mineral formation on the supported dipalmitoylphosphatidylcholine (DPPC) layers.

    Science.gov (United States)

    Szcześ, Aleksandra

    2014-07-01

    Dipalmitoylphosphatidylcholine (DPPC) mono- and bilayers supported on mica surface were soaked for two weeks in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma. Two solutions were investigated: with and without Tris. The experiment was conducted at 20°C and at a physiological temperature equal to 37°C. Raman spectroscopy was used for the characterization of the precipitated phosphate minerals. These studies may provide information about the physiological mineralization of cell membranes that are mainly composed of phospholipids. Findings from these experiments suggest that the DPPC bilayers enhance the formation of less soluble phosphate forms especially at a temperature of 37°C. In the solution without Tris temperature increase gives more mineral deposits. It is probably the hydrogen interactions between phosphate groups of the phospholipid and hydroxyl groups from Tris that lower exposure of the phosphate group to interact with calcium ions.

  15. Hierarchical bismuth phosphate microspheres with high photocatalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Lizhai; Wei, Tian; Lin, Nan; Yu, Haiyun [Anhui University of Technology, Ma' anshan (China). Key Laboratory of Materials Science and Processing of Anhui Province

    2016-05-15

    Hierarchical bismuth phosphate microspheres have been prepared by a simple hydrothermal process with polyvinyl pyrrolidone. Scanning electron microscopy observations show that the hierarchical bismuth phosphate microspheres consist of nanosheets with a thickness of about 30 nm. The diameter of the microspheres is about 1 - 3 μm. X-ray diffraction analysis shows that the microspheres are comprised of triclinic Bi{sub 23}P{sub 4}O{sub 44.5} phase. The formation of the hierarchical microspheres depends on polyvinyl pyrrolidone concentration, hydrothermal temperature and reaction time. Gentian violet acts as the pollutant model for investigating the photocatalytic activity of the hierarchical bismuth phosphate microspheres under ultraviolet-visible light irradiation. Irradiation time, dosage of the hierarchical microspheres and initial gentian violet concentration on the photocatalytic efficiency are also discussed. The hierarchical bismuth phosphate microspheres show good photocatalytic performance for gentian violet removal in aqueous solution.

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

    Science.gov (United States)

    ... enzyme is involved in the normal processing of carbohydrates. It also protects red blood cells from the ... of glucose-6-phosphate dehydrogenase or alter its structure, this enzyme can no longer play its protective ...

  17. 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....

  18. 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...

  19. Preparation and fluorescence properties of crystalline gel rare earth phosphates.

    Science.gov (United States)

    Onoda, Hiroaki; Funamoto, Takehiro

    2015-03-01

    An aqueous solution of sodium dihydrogen phosphate was mixed with a aqueous solution of lanthanum nitrate and stirred for 24 h, and the pH was adjusted to 11 using ammonia. The obtained phosphates were analyzed using X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry-differential thermal analysis, and scanning electron microscopy. The lanthanum phosphate gel was obtained with a large amount of water. The fluorescence of the gels was investigated by substituting a part of the lanthanum cations with cerium, terbium, and europium cations. UV-vis reflectance and fluorescence spectra of these substituted materials were obtained and analyzed. Rrare-earth phosphate gels with large amounts of water exhibited bluish purple, green, and red fluorescence when cation ratios of La/Ce = 70/30, La/Ce/Tb = 55/30/15, and La/Eu = 95/5 were used, respectively.

  20. Effect of Phosphate on Zinc Transport in Lou Soil

    Institute of Scientific and Technical Information of China (English)

    LUJIALONG; DONGLINGIAO; 等

    1998-01-01

    A study on the transport characteristics of zinc in lou soil with phosphate at different concentrations was carried out by the method of step input.The effects of phosphate and temperature on zinc transport were studied through analysing the diffusion-dipsersion coefficients(D) and the retardation factor(R) obtained by the program CXTFIT.The results showed that D decreased and R increased with increasig concentration of phosphate so that iv was difficult for zinc to break through the soil column,and zinc stopped to break through the column at high temperature.One order equation,double constant equation and the Elovich equation were all suitable for the escription of zinc dynamics.Effects of phosphate and temperature on zinc transport were further confirmed by the analysis on pseudo-thermodynamic parameters of zinc transport.

  1. Prevalence of glucose-6-phosphate dehydrogenase deficiency in ...

    African Journals Online (AJOL)

    Pradeep Kumar

    2016-02-06

    Feb 6, 2016 ... for studies that investigated G6PD deficiency in Indian population. If any author studied .... analyses, (2) case reports, and (3) reviews and editorials. 2.3. ..... Beutler E, editors. Glucose-6-phosphate dehydrogenase. Orlando,.

  2. Phosphate uptake and growth characteristics of transgenic rice with ...

    African Journals Online (AJOL)

    Yomi

    2012-04-03

    Apr 3, 2012 ... accumulate in soil and causes soil and water pollution. We evaluated the .... issue of water and soil pollution as well as the phosphate deficient problem. ..... Texas. Jain A, Poling MD, Karthikeyan AS, Blakeslee JJ, Peer WA,.

  3. 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,

  4. Moroccan rock phosphate solubilization during a thermo-anaerobic ...

    African Journals Online (AJOL)

    SWEET

    2013-12-04

    Dec 4, 2013 ... thermo-anaerobic grassland waste biodegradation process. Moussa S. .... plating the nutrient agar isolate on the solid NBRIP medium. (Nautiyal, 1999) ..... solubilizing fungi isolated from phosphate mines. Ecol. Eng. 33:187-.

  5. Biomimetic calcium phosphate coatings on recombinant spider silk fibres

    NARCIS (Netherlands)

    Yang, Liang; Hedhammar, My; Blom, Tobias; Leifer, Klaus; Johansson, Jan; Habibovic, Pamela; Blitterswijk, van Clemens A.

    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,

  6. 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.

  7. Destruction of Tributyl Phosphate and Exchange Resin by Electrochemical Oxidation

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Spent tributyl phosphate and spent exchange resin are difficult to treat. It's important to develop an advanced treat method. Compared with traditional methods, electrochemical oxidation has obvious advantages, such as the operation can

  8. 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.

  9. THE USE OF METAL PHOSPHATE BINDER AND SAND IN FOUNDRIES

    Directory of Open Access Journals (Sweden)

    I. E. Illarionov

    2013-01-01

    Full Text Available Some features of the use of mixtures of metal phosphate binder and management principles of their properties for production of castings of ferrous and non-ferrous metals and alloys were shown.

  10. Adsorption of 2-mercaptobenzothiazole on copper surface from phosphate solutions

    Science.gov (United States)

    Kazansky, L. P.; Selyaninov, I. A.; Kuznetsov, Yu. I.

    2012-07-01

    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.

  11. 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

  12. 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.

  13. a comparison of the influence of catholyte vs phosphate detergent ...

    African Journals Online (AJOL)

    user

    ISSN 0378-5254 Journal of Family Ecology and Consumer Sciences, Vol 41, 2013. A COMPARISON OF ... the Canadian detergents contained phosphate. Furthermore, Latin ..... The Physics, Chemistry and Biology of Water 18. -21 October.

  14. Synthesis of phosphonate and phostone analogues of ribose-1-phosphates

    Directory of Open Access Journals (Sweden)

    Pitak Nasomjai

    2009-07-01

    Full Text Available The synthesis of phosphonate analogues of ribose-1-phosphate and 5-fluoro-5-deoxyribose-1-phosphate is described. Preparations of both the α- and β-phosphonate anomers are reported for the ribose and 5-fluoro-5-deoxyribose series and a synthesis of the corresponding cyclic phostones of each α-ribose is also reported. These compounds have been prepared as tools to probe the details of fluorometabolism in S. cattleya.

  15. Synthesis of phosphonate and phostone analogues of ribose-1-phosphates.

    Science.gov (United States)

    Nasomjai, Pitak; O'Hagan, David; Slawin, Alexandra M Z

    2009-07-27

    The synthesis of phosphonate analogues of ribose-1-phosphate and 5-fluoro-5-deoxyribose-1-phosphate is described. Preparations of both the alpha- and beta-phosphonate anomers are reported for the ribose and 5-fluoro-5-deoxyribose series and a synthesis of the corresponding cyclic phostones of each alpha-ribose is also reported. These compounds have been prepared as tools to probe the details of fluorometabolism in S. cattleya.

  16. [Bone and Nutrition. The relationship between iron and phosphate metabolism].

    Science.gov (United States)

    Takashi, Yuichi; Fukumoto, Seiji

    2015-07-01

    Fibroblast growth factor 23 (FGF23) is an essential hormone for phosphate metabolism. It has been shown that intravenous administration of some iron formulations including saccharated ferric oxide induces hypophosphatemic osteomalacia with high FGF23 levels. On the other hand, iron deficiency promotes FGF23 and induces hypophosphatemia in patients with autosomal dominant hypophosphatemic rickets (ADHR). While iron and phosphate metabolism is connected, the detailed mechanism of this connection remains to be clarified.

  17. Phosphate-Induced Immobilization of Uranium in Hanford Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Zezhen; Giammar, Daniel E.; Mehta, Vrajesh; Troyer, Lyndsay D.; Catalano, Jeffrey G.; Wang, Zheming

    2016-12-20

    Phosphate can be added to subsurface environments to immobilize U(VI) contamination. The efficacy of immobilization depends on the site-specific groundwater chemistry and aquifer sediment properties. Batch and column experiments were performed with sediments from the Hanford 300 Area in Washington State and artificial groundwater prepared to emulate the conditions at the site. Batch experiments revealed enhanced U(VI) sorption with increasing phosphate addition. X-ray absorption spectroscopy measurements of samples from the batch experiments found that U(VI) was predominantly adsorbed at conditions relevant to the column experiments and most field sites (low U(VI) loadings, <25 μM), and U(VI) phosphate precipitation occurred only at high initial U(VI) (>25 μM) and phosphate loadings. While batch experiments showed the transition of U(VI) uptake from adsorption to precipitation, the column study was more directly relevant to the subsurface environment because of the high solid:water ratio in the column and the advective flow of water. In column experiments, nearly six times more U(VI) was retained in sediments when phosphate-containing groundwater was introduced to U(VI)-loaded sediments than when the groundwater did not contain phosphate. This enhanced retention persisted for at least one month after cessation of phosphate addition to the influent fluid. Sequential extractions and laser-induced fluorescence spectroscopy of sediments from the columns suggested that the retained U(VI) was primarily in adsorbed forms. These results indicate that in situ remediation of groundwater by phosphate addition provides lasting benefit beyond the treatment period via enhanced U(VI) adsorption to sediments.

  18. Antibacterial effect of phosphates and polyphosphates with different chain length.

    Science.gov (United States)

    Lorencová, Eva; Vltavská, Pavlína; Budinský, Pavel; Koutný, Marek

    2012-01-01

    The aim of this study was to monitor the antibacterial effect of seven phosphate salts on selected strains of Gram-negative and Gram-positive bacteria, which could be considered responsible for food-borne diseases (Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Micrococcus luteus, Staphylococcus aureus, Citrobacter freundii, Escherichia coli, Proteus mirabilis, Salmonella enterica ser. Enteritidis and Pseudomonas aeruginosa). For these purposes, phosphates differing in chain length were used. The tested concentrations were in the range of 0.1-2.0% (wt v(-1)) applied at the model conditions. In the majority of cases the visible inhibitory effect on the growth of observed microorganisms could be seen. Due to the chemical structure of salts and their dissociation both the pH values of cultivation broth and similarly the growth characteristics of bacterial strains were affected. The inhibition of above mentioned bacteria was apparently supported by this dissociation. Phosphates obviously made the development of most Gram-positive bacteria impossible. Especially Micrococcus luteus was extremely sensitive to the presence of these substances. On the other hand, Gram-negative bacteria seemed to be resistant to the phosphate incidence. The exemption clause from the tested salts was represented by a high alkaline trisodium phosphate. It should be pointed out that generally the most significant antibacterial effects were shown by polyphosphates HEXA68 and HEXA70, trisodium phosphate undecahydrate, tetrasodium pyrophosphate and finally trisodium phosphate. By comparing the inhibitory effects of various phosphate salts can be concluded that the antibacterial activity was not determined only by the condensation degree but there was also proved the dependence on pH values.

  19. Molecular mechanisms of crystallization impacting calcium phosphate cements

    OpenAIRE

    2010-01-01

    The biomineral calcium hydrogen phosphate dihydrate (CaHPO4·2H2O), known as brushite, is a malleable material that both grows and dissolves faster than most other calcium minerals, including other calcium phosphate phases, calcium carbonates and calcium oxalates. Within the body, this ready formation and dissolution can play a role in certain diseases, such as kidney stone and plaque formation. However, these same properties, along with brushite’s excellent biocompatibility, can be used to gr...

  20. 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.

  1. Bypassing the Pentose Phosphate Pathway: Towards Modular Utilization of Xylose

    OpenAIRE

    Kulika Chomvong; Stefan Bauer; Daniel I Benjamin; Xin Li; Daniel K Nomura; Cate, Jamie H. D.

    2016-01-01

    The efficient use of hemicellulose in the plant cell wall is critical for the economic conversion of plant biomass to renewable fuels and chemicals. Previously, the yeast Saccharomyces cerevisiae has been engineered to convert the hemicellulose-derived pentose sugars xylose and arabinose to d-xylulose-5-phosphate for conversion via the pentose phosphate pathway (PPP). However, efficient pentose utilization requires PPP optimization and may interfere with its roles in NADPH and pentose product...

  2. 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

  3. Soil phosphate stable oxygen isotopes across rainfall and bedrock gradients.

    Science.gov (United States)

    Angert, Alon; Weiner, Tal; Mazeh, Shunit; Sternberg, Marcelo

    2012-02-21

    The stable oxygen isotope compositions of soil phosphate (δ(18)O(p)) were suggested recently to be a tracer of phosphorus cycling in soils and plants. Here we present a survey of bioavailable (resin-extractable or resin-P) inorganic phosphate δ(18)O(p) across natural and experimental rainfall gradients, and across soil formed on sedimentary and igneous bedrock. In addition, we analyzed the soil HCl-extractable inorganic δ(18)O(p), which mainly represents calcium-bound inorganic phosphate. The resin-P values were in the range 14.5-21.2‰. A similar range, 15.6-21.3‰, was found for the HCl-extractable inorganic δ(18)O(p), with the exception of samples from a soil of igneous origin that show lower values, 8.2-10.9‰, which indicate that a large fraction of the inorganic phosphate in this soil is still in the form of a primary mineral. The available-P δ(18)O(p) values are considerably higher than the values we calculated for extracellular hydrolysis of organic phosphate, based on the known fractionation from lab experiments. However, these values are close to the values expected for enzymatic-mediated phosphate equilibration with soil-water. The possible processes that can explain this observation are (1) extracellular equilibration of the inorganic phosphate in the soil; (2) fractionations in the soil are different than the ones measured at the lab; (3) effect of fractionation during uptake; and (4) a flux of intercellular-equilibrated inorganic phosphate from the soil microbiota, which is considerably larger than the flux of hydrolyzed organic-P.

  4. 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.

  5. 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.

  6. Radiation exposure due to agricultural uses of phosphate fertilizers

    Energy Technology Data Exchange (ETDEWEB)

    Khater, Ashraf E.M. [National Center for Nuclear Safety and Radiation Control, Atomic Energy Authority, Cairo (Egypt); Physics Department, College of Sciences, King Saud University, P.O. Box 2455, Riyadh 1145 (Saudi Arabia)], E-mail: khater_ashraf@yahoo.com; AL-Sewaidan, H.A. [Physics Department, College of Sciences, King Saud University, P.O. Box 2455, Riyadh 1145 (Saudi Arabia)

    2008-09-15

    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 {sup 238}U series, {sup 232}Th series and {sup 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 {sup 226}Ra, {sup 210}Po, {sup 232}Th and {sup 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.

  7. 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.

  8. Conductance based sensing and analysis of soluble phosphates in wastewater.

    Science.gov (United States)

    Warwick, Christopher; Guerreiro, Antonio; Gomez-Caballero, Alberto; Wood, Elizabeth; Kitson, James; Robinson, James; Soares, Ana

    2014-02-15

    The current standard method used for measuring soluble phosphate in environmental water samples is based on a colourimetric approach, developed in the early 1960s. In order to provide an alternative, label free sensing solution, a molecularly imprinted polymer (MIP) was designed to function as a phosphate receptor. A combination of functional monomer (N-allylthiourea), cross-linker and monomer/template ratios were optimised in order to maximise the binding capacity for phosphate. When produced in membrane format, the MIP's ability to produce a reversible change in conductance in the presence of phosphate was explored for fabrication of a sensor which was able to selectively detect the presence of phosphate compared to sulphate, nitrate and chloride. In wastewater samples the sensor had a limit of detection of 0.16 mg P/l, and a linear range between 0.66 and 8 mg P/l. This is below the minimum monitoring level (1 mg P/l) as required by current legislation for wastewater discharges, making the sensor as developed promising for direct quantification of phosphate in environmental monitoring applications.

  9. Phosphate starvation enhances the pathogenesis of Bacillus anthracis.

    Science.gov (United States)

    Aggarwal, Somya; Somani, Vikas Kumar; Bhatnagar, Rakesh

    2015-09-01

    Identifying the factors responsible for survival and virulence of Bacillus anthracis within the host is prerequisite for the development of therapeutics against anthrax. Host provides several stresses as well as many advantages to the invading pathogen. Inorganic phosphate (Pi) starvation within the host has been considered as one of the major contributing factors in the establishment of infection by pathogenic microorganisms. Here, we report for the first time that Pi fluctuation encountered by B. anthracis at different stages of its life cycle within the host, contributes significantly in its pathogenesis. In this study, Pi starvation was found to hasten the onset of infection cycle by promoting spore germination. After germination, it was found to impede cell growth. In addition, phosphate starved bacilli showed more antibiotic tolerance. Interestingly, phosphate starvation enhanced the pathogenicity of B. anthracis by augmenting its invasiveness in macrophages in vitro. B. anthracis grown under phosphate starvation were also found to be more efficient in establishing lethal infections in mouse model as well. Phosphate starvation increased B. anthracis virulence by promoting the secretion of primary virulence factors like protective antigen (PA), lethal factor (LF) and edema factor (EF). Thus, this study affirms that besides other host mediated factors, phosphate limitation may also contribute B. anthracis for successfully establishing itself within the host. This study is a step forward in delineating its pathophysiology that might help in understanding the pathogenesis of anthrax.

  10. Bioturbation-induced phosphorous release from an insoluble phosphate source.

    Science.gov (United States)

    Chakrabarty, D; Das, S K

    2007-01-01

    The influence of bioturbation caused by common carp fry in 5 L jars (5 L each) in the laboratory and in 150 L outdoor vats in increasing the fertilizer value of phosphate rock was evaluated. Soluble reactive phosphate (SRP) was determined to quantify the effects of bioturbation, fish excrements and soil. The level of SRP was always lowest in the control series. Introduction of common carp fry resulted in a net increase of 0.09-0.10 mg L(-1) of SRP attributable to the effect of fish excrement. Bioturbation caused by common carp resulted in a 64.8-90% influx of phosphate from bottom soil in the presence of phosphate rock but only about 6.3-7.2% in the absence of phosphate rock. The bioturbation that occurred in these treatments resulted in a significant release of phosphorous into the overlying water from the apatite source. The results confirm the benefits of the application of environmentally friendly phosphate rock in fish farming ponds at low cost.

  11. Phosphite disrupts the acclimation of Saccharomyces cerevisiae to phosphate starvation.

    Science.gov (United States)

    McDonald, A E; Niere, J O; Plaxton, W C

    2001-11-01

    The influence of phosphite (H2PO3-) on the response of Saccharomyces cerevisiae to orthophosphate (HPO4(2-); Pi) starvation was assessed. Phosphate-repressible acid phosphatase (rAPase) derepression and cell development were abolished when phosphate-sufficient (+Pi) yeast were subcultured into phosphate-deficient (-Pi) media containing 0.1 mM phosphite. By contrast, treatment with 0.1 mM phosphite exerted no influence on rAPase activity or growth of +Pi cells. 31P NMR spectroscopy revealed that phosphite is assimilated and concentrated by yeast cultured with 0.1 mM phosphite, and that the levels of sugar phosphates, pyrophosphate, and particularly polyphosphate were significantly reduced in the phosphite-treated -Pi cells. Examination of phosphite's effects on two PHO regulon mutants that constitutively express rAPase indicated that (i) a potential target for phosphite's action in -Pi yeast is Pho84 (plasmalemma high-affinity Pi transporter and component of a putative phosphate sensor-complex), and that (ii) an additional mechanism exists to control rAPase expression that is independent of Pho85 (cyclin-dependent protein kinase). Marked accumulation of polyphosphate in the delta pho85 mutant suggested that Pho85 contributes to the control of polyphosphate metabolism. Results are consistent with the hypothesis that phosphite obstructs the signaling pathway by which S. cerevisiae perceives and responds to phosphate deprivation at the molecular level.

  12. Mineralisation of two phosphate ceramics in HBSS: role of albumin.

    Science.gov (United States)

    Marques, P A A P; Serro, A P; Saramago, B J; Fernandes, A C; Magalhães, M C F; Correia, R N

    2003-02-01

    The role of albumin in the mineralisation process of commercial hydroxyapatite (HAp) and synthesised biphasic (HAp-tricalcium phosphate) ceramics in a bufferless simulated inorganic plasma (HBSS) was investigated by conventional in vitro tests and static and dynamic wettability measurements. Albumin was either pre-adsorbed or solubilised in HBSS. It was found that calcium complexation by albumin plays a key role in early mineralisation kinetics, so that mineralisation is favoured when albumin is pre-adsorbed and hindered when it is dissolved in HBSS. In the biphasic ceramic this picture is complicated by the fact that albumin, in solution, seems to promote the dissolution of tricalcium phosphate, and simultaneously compete for calcium with the ceramic. It also appears that albumin has a stabilising effect of octacalcium phosphate present in deposits on commercial HAp. The same effect may be present in the case of the biphasic ceramic, at earlier mineralisation times, when octacalcium phosphate appears as a precursor of HAp. Octacalcium phosphate formation on commercial apatite is accompanied by carbonate substitution in phosphate positions.

  13. 75 FR 22234 - Phosphate Ester, Tallowamine, Ethoxylated; Exemption from the Requirement of a Tolerance

    Science.gov (United States)

    2010-04-28

    ... AGENCY 40 CFR Part 180 Phosphate Ester, Tallowamine, Ethoxylated; Exemption from the Requirement of a... establishes an exemption from the requirement of a tolerance for residues of phosphate ester, tallowamine..., ethoxylated, mixture of dihydrogen phosphate and monohydrogen phosphate esters and the corresponding...

  14. 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.

  15. Phosphate availability in the soil-root system: integration of oxide surface chemistry, transport and uptake.

    NARCIS (Netherlands)

    Geelhoed, J.S.

    1998-01-01

    A study is presented on the adsorption of phosphate on goethite, the interaction of phosphate with other adsorbing ions at the goethite surface, and the resulting availability of phosphate to plants. The plant-availability of sorbed phosphate was determined from phosphorus uptake of plants growing o

  16. Thermally highly stable amorphous zinc phosphate intermediates during the formation of zinc phosphate hydrate.

    Science.gov (United States)

    Bach, Sven; Celinski, Vinicius R; Dietzsch, Michael; Panthöfer, Martin; Bienert, Ralf; Emmerling, Franziska; Schmedt auf der Günne, Jörn; Tremel, Wolfgang

    2015-02-18

    The mechanisms by which amorphous intermediates transform into crystalline materials are still poorly understood. Here we attempt to illuminate the formation of an amorphous precursor by investigating the crystallization process of zinc phosphate hydrate. This work shows that amorphous zinc phosphate (AZP) nanoparticles precipitate from aqueous solutions prior to the crystalline hopeite phase at low concentrations and in the absence of additives at room temperature. AZP nanoparticles are thermally stable against crystallization even at 400 °C (resulting in a high temperature AZP), but they crystallize rapidly in the presence of water if the reaction is not interrupted. X-ray powder diffraction with high-energy synchrotron radiation, scanning and transmission electron microscopy, selected area electron diffraction, and small-angle X-ray scattering showed the particle size (≈20 nm) and confirmed the noncrystallinity of the nanoparticle intermediates. Energy dispersive X-ray, infrared, and Raman spectroscopy, inductively coupled plasma mass spectrometry, and optical emission spectrometry as well as thermal analysis were used for further compositional characterization of the as synthesized nanomaterial. (1)H solid-state NMR allowed the quantification of the hydrogen content, while an analysis of (31)P{(1)H} C rotational echo double resonance spectra permitted a dynamic and structural analysis of the crystallization pathway to hopeite.

  17. Sphingosine 1-phosphate receptor agonist FTY720-phosphate causes marginal zone B cell displacement.

    Science.gov (United States)

    Vora, Kalpit A; Nichols, Elizabeth; Porter, Gene; Cui, Yan; Keohane, Carol Ann; Hajdu, Richard; Hale, Jeffery; Neway, William; Zaller, Dennis; Mandala, Suzanne

    2005-08-01

    FTY720 is an immunosuppressive agent that modulates lymphocyte trafficking. It is phosphorylated in vivo to FTY720-phosphate (FTY-P) and binds to a family of G protein-coupled receptors recognizing sphingosine 1-phosphate (S1P) as the natural ligand. It has previously been reported that FTY-P blocks egress of lymphocytes from the thymus and lymph nodes, resulting in peripheral blood lymphopenia. We now report that FTY-P also causes displacement of marginal zone (MZ) B cells to the splenic follicles, an effect that is similar to that observed after in vivo administration of lipopolysaccharide. This effect is specific to B cells in the MZ, as treatment with FTY-P does not cause redistribution of the resident macrophage population. A small but statistically significant decrease in the expression of beta1 integrin on MZ B cells was observed with FTY-P treatment. The redistribution of MZ B cells from the MZ sinuses does not abolish the ability of these cells to respond to the T-independent antigen, trinitrophenol-Ficoll. It has been proposed that the displacement of MZ B cells to the follicles is an indication of cell activation. Consistent with this, FTY-P caused an increase in percentage of MZ B cells expressing activation markers CD9, CD1d, and CD24. These results suggest that S1P receptors on MZ B cells are responsible for their mobilization to follicles.

  18. Dipentaerythritol penta-acrylate phosphate - an alternative phosphate ester monomer for bonding of methacrylates to zirconia

    Science.gov (United States)

    Chen, Ying; Tay, Franklin R.; Lu, Zhicen; Chen, Chen; Qian, Mengke; Zhang, Huaiqin; Tian, Fucong; Xie, Haifeng

    2016-12-01

    The present work examined the effects of dipentaerythritol penta-acrylate phosphate (PENTA) as an alternative phosphate ester monomer for bonding of methacrylate-based resins to yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) and further investigated the potential bonding mechanism involved. Shear bond strength testing was performed to evaluate the efficacy of experimental PENTA-containing primers (5, 10, 15, 20 or 30 wt% PENTA in acetone) in improving resin-Y-TZP bond strength. Bonding without the use of a PENTA-containing served as the negative control, and a Methacryloyloxidecyl dihydrogenphosphate(MDP)-containing primer was used as the positive control. Inductively coupled plasma-mass spectrometry (ICP-MS), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) were used to investigate the potential existence of chemical affinity between PENTA and Y-TZP. Shear bond strengths were significant higher in the 15 and 20 wt% PENTA groups. The ICP-MS, XPS and FTIR data indicated that the P content on the Y-TZP surface increased as the concentration of PENTA increased in the experimental primers, via the formation of Zr–O–P bond. Taken together, the results attest that PENTA improves resin bonding of Y-TZP through chemical reaction with Y-TZP. Increasing the concentration of PENTA augments its binding affinity but not its bonding efficacy with zirconia.

  19. Fungal rock phosphate solubilization using sugarcane bagasse.

    Science.gov (United States)

    Mendes, Gilberto O; Dias, Carla S; Silva, Ivo R; Júnior, José Ivo Ribeiro; Pereira, Olinto L; Costa, Maurício D

    2013-01-01

    The effects of different doses of rock phosphate (RP), sucrose, and (NH(4))(2)SO(4) on the solubilization of RP from Araxá and Catalão (Brazil) by Aspergillus niger, Penicillium canescens, Eupenicillium ludwigii, and Penicillium islandicum were evaluated in a solid-state fermentation (SSF) system with sugarcane bagasse. The factors evaluated were combined following a 2(3) + 1 factorial design to determine their optimum concentrations. The fitted response surfaces showed that higher doses of RP promoted higher phosphorus (P) solubilization. The addition of sucrose did not have effects on P solubilization in most treatments due to the presence of soluble sugars in the bagasse. Except for A. niger, all the fungi required high (NH(4))(2)SO(4) doses to achieve the highest level of P solubilization. Inversely, addition of (NH(4))(2)SO(4) was inhibitory to P solubilization by A. niger. Among the fungi tested, A. niger stood out, showing the highest solubilization capacity and for not requiring sucrose or (NH(4))(2)SO(4) supplementation. An additional experiment with A. niger showed that the content of soluble P can be increased by adding higher RP doses in the medium. However, P yield decreases with increasing RP doses. In this experiment, the maximal P yield (approximately 60 %) was achieved with the lower RP dose (3 g L(-1)). Our results show that SSF can be used to obtain a low cost biofertilizer rich in P combining RP, sugarcane bagasse, and A. niger. Moreover, sugarcane bagasse is a suitable substrate for SSF aiming at RP solubilization, since this residue can supply the C and N necessary for the metabolism of A. niger within a range that favors RP solubilization.

  20. Phosphate binders in chronic kidney disease: a systematic review of recent data.

    Science.gov (United States)

    Floege, Jürgen

    2016-06-01

    Hyperphosphatemia is common in chronic kidney disease (CKD) and is treated by dietary measures, dialysis techniques and/or phosphate binders. For the present review PubMed was searched for new publications on phosphate binders appearing between January 2010 and October 2015. This review summarizes the latest information on non-pharmacological measures and their problems in lowering phosphate in CKD patients, effects of phosphate binders on morbidity and mortality, adherence to phosphate binder therapy as well as new information on specific aspects of the various phosphate binders on the market: calcium acetate, calcium carbonate, magnesium-containing phosphate binders, polymeric phosphate binders (sevelamer, bixalomer, colestilan), lanthanum carbonate, ferric citrate, sucroferric oxyhydroxide, aluminum-containing phosphate binders, and new compounds in development. The review also briefly covers the emerging field of drugs targeting intestinal phosphate transporters.

  1. Distinct generation, pharmacology, and distribution of sphingosine 1-phosphate and dihydro-sphingosine 1-phosphate in human neural progenitor cells

    Science.gov (United States)

    In-vivo and in-vitro studies suggest a crucial role for Sphingosine 1-phosphate (S1P) and its receptors in the development of the nervous system. Dihydrosphingosine 1-phosphate (dhS1P), a reduced form of S1P, is an active ligand at S1P receptors, but the pharmacology and physiology of dhS1P has not...

  2. Isolation and identification of a phosphate solubilising fungus from soil of a phosphate mine in Chaluse, Iran

    Directory of Open Access Journals (Sweden)

    Raheleh Jamshidi

    2016-07-01

    Full Text Available Microbial solubilisation of phosphorus from insoluble phosphates is an environmental friendly and cost effective approach in sustainable soil management. Introducing the indigenous microorganisms to soil requires shorter adaptation period and causes fewer ecological distortions than exogenous microorganisms. This study was conducted to isolate and identify the indigenous fungi for phosphate solubilisation in Mazandaran, Iran. A potent phosphate solubilising fungus was isolated from an Iranian phosphate mine and selected for solubilisation of rock phosphate (RP. The identified fungus was characterised by calmodulin-based polymerase chain reaction method as Aspergillus tubingensis SANRU (Sari Agricultural Sciences and Natural Resources University. The phosphate solubilisation ability of the fungal strain was carried out in shake-flask leaching experiments containing various concentrations of RP (1%, 2%, 4%, or 8% w/v. The maximum P solubilisation rate of 347 mg/l was achieved at 1% of RP concentration on day 9. The regression analysis indicated that the P solubilised mainly through acidification. This study shows the possibility of using A. tubingensis SANRU for application in the management of P fertilisation.

  3. Characterization of a calcium phosphate cement based on alpha-tricalcium phosphate obtained by wet precipitation process

    Energy Technology Data Exchange (ETDEWEB)

    Thurmer, M.B.; Diehl, C.E.; Vieira, R.S.; Coelho, W.T.G.; Santos, L.A., E-mail: monicathurmer@yahoo.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Dept. de Engenharia de Materiais

    2012-07-01

    There are several systems of calcium phosphate cements being studied. Those based on alpha-tricalcium phosphate are of particular interest. After setting they produce calcium deficient hydroxyapatite similar to bone like hydroxyapatite. This work aims to obtain alpha-tricalcium phosphate powders by the wet precipitation process, using calcium nitrate and phosphoric acid as reagents. This powder was characterized by infrared spectroscopy, X-ray diffraction and particle size distribution. In order to prepare the calcium phosphate cement, the powder was mixed with an accelerator in an aqueous solution. The mechanical properties of the cement were assessed and it was evaluated by means of apparent density, X-ray diffraction and scanning electron microscopy. The described method produced crystalline alpha-tricalcium phosphate as the major phase. The calcium phosphate cement showed high values of compression strength (50 MPa). The soaking of the cement in a simulated body fluid (SBF) formed a layer of hydroxyapatite like crystals in the surface of the samples. (author)

  4. Reducing the Genetic Redundancy of Arabidopsis PHOSPHATE TRANSPORTER1 Transporters to Study Phosphate Uptake and Signaling1[OPEN

    Science.gov (United States)

    Ayadi, Amal; David, Pascale; Arrighi, Jean-François; Chiarenza, Serge; Thibaud, Marie-Christine; Nussaume, Laurent; Marin, Elena

    2015-01-01

    Arabidopsis (Arabidopsis thaliana) absorbs inorganic phosphate (Pi) from the soil through an active transport process mediated by the nine members of the PHOSPHATE TRANSPORTER1 (PHT1) family. These proteins share a high level of similarity (greater than 61%), with overlapping expression patterns. The resulting genetic and functional redundancy prevents the analysis of their specific roles. To overcome this difficulty, our approach combined several mutations with gene silencing to inactivate multiple members of the PHT1 family, including a cluster of genes localized on chromosome 5 (PHT1;1, PHT1;2, and PHT1;3). Physiological analyses of these lines established that these three genes, along with PHT1;4, are the main contributors to Pi uptake. Furthermore, PHT1;1 plays an important role in translocation from roots to leaves in high phosphate conditions. These genetic tools also revealed that some PHT1 transporters likely exhibit a dual affinity for phosphate, suggesting that their activity is posttranslationally controlled. These lines display significant phosphate deficiency-related phenotypes (e.g. biomass and yield) due to a massive (80%–96%) reduction in phosphate uptake activities. These defects limited the amount of internal Pi pool, inducing compensatory mechanisms triggered by the systemic Pi starvation response. Such reactions have been uncoupled from PHT1 activity, suggesting that systemic Pi sensing is most probably acting downstream of PHT1. PMID:25670816

  5. Encapsulation in alginate enhanced the plant growth promoting activities of two phosphate solubilizing bacteria isolated from the phosphate mine of Gafsa

    OpenAIRE

    Mounira Ben Farhat; Salma Taktek; Hichem Chouayekh

    2014-01-01

    To develop a maize inoculant allowing the use of sparingly soluble inorganic phosphates, the potential of two phosphate solubilizing bacteria isolated from the Gafsa rock phosphate mine, namely Serratia marcescens CTM 50650 and Enterobacter sp. US468 was assessed. At first, these phosphate solubilizing bacteria were analyzed for plant growth promoting activities like acid and alkaline phosphatase, and indole acetic acid production. Both isolates produced alkaline and acid phosphatase at 35.73...

  6. Phosphate binding protein as the biorecognition element in a biosensor for phosphate

    Science.gov (United States)

    Salins, Lyndon L E.; Deo, Sapna K.; Daunert, Sylvia

    2004-01-01

    This work explores the potential use of a member of the periplasmic family of binding proteins, the phosphate binding protein (PBP), as the biorecognition element in a sensing scheme for the detection of inorganic phosphate (Pi). The selectivity of this protein originates from its natural role which, in Escherichia coli, is to serve as the initial receptor for the highly specific translocation of Pi to the cytoplasm. The single polypeptide chain of PBP is folded into two similar domains connected by three short peptide linkages that serve as a hinge. The Pi binding site is located deep within the cleft between the two domains. In the presence of the ligand, the two globular domains engulf the former in a hinge-like manner. The resultant conformational change constitutes the basis of the sensor development. A mutant of PBP (MPBP), where an alanine was replaced by a cysteine residue, was prepared by site-directed mutagenesis using the polymerase chain reaction (PCR). The mutant was expressed, from plasmid pSD501, in the periplasmic space of E. coli and purified in a single chromatographic step on a perfusion anion-exchange column. Site-specific labeling was achieved by attaching the fluorophore, N-[2-(1-maleimidyl)ethyl]-7-(diethylamino)coumarin-3-carboxamide (MDCC), to the protein through the sulfhydryl group of the cysteine moiety. Steady-state fluorescence studies of the MPBP-MDCC conjugate showed a change in the intensity of the signal upon addition of Pi. Calibration curves for Pi were constructed by relating the intensity of the fluorescence signal with the amount of analyte present in the sample. The sensing system was first developed and optimized on a spectrofluorometer using ml volumes of sample. It was then adapted to be used on a microtiter plate arrangement with microliter sample volumes. The system's versatility was finally proven by developing a fiber optic fluorescence-based sensor for monitoring Pi. In all three cases the detection limits for the

  7. Soluble phosphate fertilizer production using acid effluent from metallurgical industry.

    Science.gov (United States)

    Mattiello, Edson M; Resende Filho, Itamar D P; Barreto, Matheus S; Soares, Aline R; Silva, Ivo R da; Vergütz, Leonardus; Melo, Leônidas C A; Soares, Emanuelle M B

    2016-01-15

    Preventive and effective waste management requires cleaner production strategies and technologies for recycling and reuse. Metallurgical industries produce a great amount of acid effluent that must be discarded in a responsible manner, protecting the environment. The focus of this study was to examine the use of this effluent to increase reactivity of some phosphate rocks, thus enabling soluble phosphate fertilizer production. The effluent was diluted in deionized water with the following concentrations 0; 12.5; 25; 50; 75% (v v(-1)), which were added to four natural phosphate rocks: Araxá, Patos, Bayovar and Catalão and then left to react for 1 h and 24 h. There was an increase in water (PW), neutral ammonium citrate (PNAC) and citric acid (PCA) soluble phosphorus fractions. Such increases were dependent of rock type while the reaction time had no significant effect (p < 0.05) on the chemical and mineralogical phosphate characteristics. Phosphate fertilizers with low toxic metal concentrations and a high level of micronutrients were produced compared to the original natural rocks. The minimum amount of total P2O5, PNAC and PW, required for national legislation for phosphate partially acidulated fertilizer, were met when using Catalão and the effluent at the concentration of 55% (v v(-1)). Fertilizer similar to partially acidulated phosphate was obtained when Bayovar with effluent at 37.5% (v v(-1)) was used. Even though fertilizers obtained from Araxá and Patos did not contain the minimum levels of total P2O5 required by legislation, they can be used as a nutrient source and for acid effluent recycling and reuse. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Bioreduction of U(VI) in the presence of phosphate

    Science.gov (United States)

    Boyanov, M. I.; Mishra, B.; Latta, D. E.; Rui, X.; Kwon, M.-J.; Fletcher, K. E.; Loeffler, F. E.; O'Loughlin, E. J.; Kemner, K. M.

    2012-04-01

    Phosphate/phosphoryl moieties are ubiquitous in biological and environmental systems and can potentially affect the speciation of uranium during natural attenuation or stimulated bioremediation processes. The reactivity between U(VI) and phosphate has been studied extensively, but the significant influence of phosphate groups on the formation of reduced U(IV) species has only recently been recognized. We will compare and contrast the bioreduction of dissolved and solid-phase U(VI) by Gram-positive and Gram-negative metal-reducing bacteria (Shewanella, Anaeromyxobacter, Geobacter, and Desulfitobacterium) in the presence and absence of phosphate, from the perspective of solid-phase U speciation as determined by U L-edge x-ray absorption spectroscopy (XANES and EXAFS). In all cases examined, the presence of phosphate at concentrations of P/U > 1 led to the formation of reduced, inner-sphere complexed U(IV)-phosphate species that prevented the lowest-solubility U(IV) mineral uraninite (UO2) from forming over at least several months. In the absence of phosphate, nanoparticulate uraninite or complexed non-uraninite U(IV) species were observed (depending on the system and conditions), suggesting that the interplay between the chemical conditions at the location of electron transfer to U(VI) control the U(IV) product and subsequently the stability of reduced U. The importance of non-uraninite U(IV) species will be discussed in the context of their predominance in biostimulated sediments from the Oak Ridge field site in the United States.

  9. Phosphate-enhanced cytotoxicity of zinc oxide nanoparticles and agglomerates.

    Science.gov (United States)

    Everett, W Neil; Chern, Christina; Sun, Dazhi; McMahon, Rebecca E; Zhang, Xi; Chen, Wei-Jung A; Hahn, Mariah S; Sue, H-J

    2014-02-10

    Zinc oxide (ZnO) nanoparticles (NPs) have been found to readily react with phosphate ions to form zinc phosphate (Zn3(PO4)2) crystallites. Because phosphates are ubiquitous in physiological fluids as well as waste water streams, it is important to examine the potential effects that the formation of Zn3(PO4)2 crystallites may have on cell viability. Thus, the cytotoxic response of NIH/3T3 fibroblast cells was assessed following 24h of exposure to ZnO NPs suspended in media with and without the standard phosphate salt supplement. Both particle dosage and size have been shown to impact the cytotoxic effects of ZnO NPs, so doses ranging from 5 to 50 μg/mL were examined and agglomerate size effects were investigated by using the bioinert amphiphilic polymer polyvinylpyrrolidone (PVP) to generate water-soluble ZnO ranging from individually dispersed 4 nm NPs up to micron-sized agglomerates. Cell metabolic activity measures indicated that the presence of phosphate in the suspension media can led to significantly reduced cell viability at all agglomerate sizes and at lower ZnO dosages. In addition, a reduction in cell viability was observed when agglomerate size was decreased, but only in the phosphate-containing media. These metabolic activity results were reflected in separate measures of cell death via the lactate dehydrogenase assay. Our results suggest that, while higher doses of water-soluble ZnO NPs are cytotoxic, the presence of phosphates in the surrounding fluid can lead to significantly elevated levels of cell death at lower ZnO NP doses. Moreover, the extent of this death can potentially be modulated or offset by tuning the agglomerate size. These findings underscore the importance of understanding how nanoscale materials can interact with the components of surrounding fluids so that potential adverse effects of such interactions can be controlled.

  10. Phosphate Solubilization Potentials of Rhizosphere Isolates from Central Anatolia (Turkey)

    Science.gov (United States)

    Ogut, M.; Er, F.

    2009-04-01

    Plant available-phosphorus (P) is usually low in Anatolian soils due mainly to the precipitation as calcium (Ca) and magnesium (Mg) phosphates in alkaline conditions. Phosphate solubilizing microorganisms (PSM) can enhance plant P-availability by dissolving the hardly soluble-P within the rhizosphere, which is the zone that surrounds the plant roots. PSM's can be used as seed- or soil-inocula to increase plant P-uptake and the overall growth. A total of 162 PSM's were isolated from the rhizosphere of wheat plants excavated from different fields located along a 75 km part of a highway in Turkey. The mean, the standart deviation, and the median for solubilized-P (ppm) in a 24 h culture in a tricalcium phosphate broth were 681, 427, and 400 for glucose; 358, 266, and 236 for sucrose; and 102, 117, and 50 for starch, respectively. There was not a linear relationship between the phosphate solubilized in the liquid cultures and the solubilization index obtained in the Pikovskaya's agar. Nine isolates representing both weak and strong solubilizers [Bacillus megaterium (5), Bacillus pumilis (1), Pseudomonas syringae pv. phaseolica (1), Pseudomonas fluorescens (1), Arthrobacter aurescens (1) as determined by the 16S rRNA gene sequence analysis] were further studied in a five day incubation. Pseudomonas syringae pv. phaseolica solubilized statistically (P<0.05) higher phosphate (409 ppm) than all the other strains did. There was not a statistically significant (P<0.05) difference in solubilized-P among the Bacillus strains. The pH of the medium fell to the levels between 4 and 5 from the initial neutrality. The phosphate solubilizing strains variably produced gluconic, 2-keto-D-gluconic, glycolic, acetic and butyric acids. The organic acids produced by these microorganisms seem to be the major source of phosphate solubilization in vitro.

  11. Expression of Phosphate Transporters during Dental Mineralization.

    Science.gov (United States)

    Merametdjian, L; Beck-Cormier, S; Bon, N; Couasnay, G; Sourice, S; Guicheux, J; Gaucher, C; Beck, L

    2017-09-01

    The importance of phosphate (Pi) as an essential component of hydroxyapatite crystals suggests a key role for membrane proteins controlling Pi uptake during mineralization in the tooth. To clarify the involvement of the currently known Pi transporters (Slc17a1, Slc34a1, Slc34a2, Slc34a3, Slc20a1, Slc20a2, and Xpr1) during tooth development and mineralization, we determined their spatiotemporal expression in murine tooth germs from embryonic day 14.5 to postnatal day 15 and in human dental samples from Nolla stages 6 to 9. Using real-time polymerase chain reaction, in situ hybridization, immunohistochemistry, and X-gal staining, we showed that the expression of Slc17a1, Slc34a1, and Slc34a3 in tooth germs from C57BL/6 mice were very low. In contrast, Slc34a2, Slc20a1, Slc20a2, and Xpr1 were highly expressed, mostly during the postnatal stages. The expression of Slc20a2 was 2- to 10-fold higher than the other transporters. Comparable results were obtained in human tooth germs. In mice, Slc34a2 and Slc20a1 were predominantly expressed in ameloblasts but not odontoblasts, while Slc20a2 was detected neither in ameloblasts nor in odontoblasts. Rather, Slc20a2 was highly expressed in the stratum intermedium and the subodontoblastic cell layer. Although Slc20a2 knockout mice did not show enamel defects, mutant mice showed a disrupted dentin mineralization, displaying unmerged calcospherites at the mineralization front. This latter phenotypical finding raises the possibility that Slc20a2 may play an indirect role in regulating the extracellular Pi availability for mineralizing cells rather than a direct role in mediating Pi transport through mineralizing plasma cell membranes. By documenting the spatiotemporal expression of Pi transporters in the tooth, our data support the possibility that the currently known Pi transporters may be dispensable for the initiation of dental mineralization and may rather be involved later during the tooth mineralization scheme.

  12. Pyridoxal-5'-phosphate-dependent catalytic antibodies.

    Science.gov (United States)

    Gramatikova, Svetlana; Mouratou, Barbara; Stetefeld, Jörg; Mehta, Perdeep K; Christen, Philipp

    2002-11-01

    Strategies for expanding the catalytic scope of antibodies include the incorporation of inorganic or organic cofactors into their binding sites. An obvious choice is pyridoxal-5'-phosphate (PLP), which is probably the most versatile organic cofactor of enzymes. Monoclonal antibodies against the hapten N(alpha)-(5'-phosphopyridoxyl)-L-lysine, a stable analog of the covalent coenzyme-substrate adducts were screened by a competition ELISA for binding of the PLP-amino acid Schiff base adduct. The Schiff base with its C4'-N alpha double bond is, in contrast to the hapten, a planar compound and is an obligatory intermediate in all PLP-dependent reactions of amino acids. This highly discriminating screening step eliminated all but 5 of 24 hapten-binding antibodies. The five remaining antibodies were tested for catalysis of the PLP-dependent alpha,beta-elimination reaction of beta-chloroalanine. Antibody 15A9 complied with this selection criterion and catalyzed in addition the cofactor-dependent transamination reaction of hydrophobic D-amino acids and oxo acids (k(cat)'=0.42 min(-1) with D-alanine at 25 degrees C). Homology modeling together with alanine scanning yielded a 3D model of Fab 15A9. The striking analogy between antibody 15A9 and PLP-dependent enzymes includes the following features: (1) The binding sites accommodate the planar coenzyme-amino acid adduct. (2) The bond at C alpha to be broken lies together with the C alpha-N bond in a plane orthogonal to the plane of coenzyme and imine bond. (3) The alpha-carboxylate group of the substrate is bound by an arginine residue. (4) The coenzyme-substrate adduct assumes a cisoid conformation. (5) PLP markedly contributes to catalytic efficiency, being a 10(4) times more efficient amino group acceptor than pyruvate. The protein moiety, however, ensures reaction as well as substrate specificity, and further accelerates the reaction (in 15A9 k(cat (Ab x PLP))'/k(cat (PLP))'=5 x 10(3)). The analogies of antibody 15A9 with

  13. Phosphate inhibits in vitro Fe3+ loading into transferrin by forming a soluble Fe(III)-phosphate complex: a potential non-transferrin bound iron species.

    Science.gov (United States)

    Hilton, Robert J; Seare, Matthew C; Andros, N David; Kenealey, Zachary; Orozco, Catalina Matias; Webb, Michael; Watt, Richard K

    2012-05-01

    In chronic kidney diseases, NTBI can occur even when total iron levels in serum are low and transferrin is not saturated. We postulated that elevated serum phosphate concentrations, present in CKD patients, might disrupt Fe(3+) loading into apo-transferrin by forming Fe(III)-phosphate species. We report that phosphate competes with apo-transferrin for Fe(3+) by forming a soluble Fe(III)-phosphate complex. Once formed, the Fe(III)-phosphate complex is not a substrate for donating Fe(3+) to apo-transferrin. Phosphate (1-10mM) does not chelate Fe(III) from diferric transferrin under the conditions examined. Complexed forms of Fe(3+), such as iron nitrilotriacetic acid (Fe(3+)-NTA), and Fe(III)-citrate are not susceptible to this phosphate complexation reaction and efficiently deliver Fe(3+) to apo-transferrin in the presence of phosphate. This reaction suggests that citrate might play an important role in protecting against Fe(III), phosphate interactions in vivo. In contrast to the reactions of Fe(3+) and phosphate, the addition of Fe(2+) to a solution of apo-transferrin and phosphate lead to rapid oxidation and deposition of Fe(3+) into apo-transferrin. These in vitro data suggest that, in principle, elevated phosphate concentrations can influence the ability of apo-transferrin to bind iron, depending on the oxidation state of the iron.

  14. Powder properties of binary mixtures of chloroquine phosphate with lactose and dicalcium phosphate

    Directory of Open Access Journals (Sweden)

    Michael Ayodele Odeniyi

    2010-09-01

    Full Text Available A study was conducted on the packing and cohesive properties of chloroquine phosphate in binary mixtures with lactose and dicalcium phosphate powders. The maximum volume reduction due to packing as expressed by the Kawakita constant, a, and the angle of internal flow, θ, were the assessment parameters. The individual powders were characterized for their particle size and shape using an optical microscope. Binary mixtures of various proportions of chloroquine phosphate with lactose and dicalcium phosphate powders were prepared. The bulk and tapped densities, angles of repose and internal flow, as well as compressibility index of the materials were determined using appropriate parameters. The calculated and determined values of maximum volume reduction for the binary mixtures were found to differ significantly (PRealizou-se estudo das propriedades de empacotamento e de coesão do fosfato de cloroquina em misturas binárias com lactose e fosfato dicálcico em pó. O volume máximo de redução devido ao empacotamento, segundo expresso pela constante de Kawakita, a, e o ângulo de fluxo interno, θ, foram os parâmetros de avaliação. Os pós individuais foram caracterizados por seu tamanho e forma de partículas, utilizando microscópio óptico. Prepararam-se misturas binárias de várias proporções de fosfato de cloroquine e lactose e fosfato dicálcico em pó. As densidades de bulk and tapped, os ângulos de repouso e de fluxo interno e o índice de compressibilidade dos materiais foram determinados utilizando-se parâmetros apropriados. Os valores calculados e determinados do volume máximo de redução para as misturas binárias mostraram-se significativamente diferentes (P< 0,05, sendo o traçado de Kawakita mais confiável na determinação das propriedades de empacotamento. O tipo de diluente influenciou as propriedades de fluxo das misturas com fosfato dicálcico, dando resultados previsíveis, enquanto as misturas contendo lactose

  15. Antimicrobial effects of silver zeolite, silver zirconium phosphate silicate and silver zirconium phosphate against oral microorganisms

    Institute of Scientific and Technical Information of China (English)

    Sirikamon Saengmee-anupharb; Toemsak Srikhirin; Boonyanit Thaweboon; Sroisiri Thaweboon; Taweechai Amornsakchai; Surachai Dechkunakorn; Theeralaksna Suddhasthira

    2013-01-01

    Objective: To evaluate the antimicrobial activities of silver inorganic materials, including silver zeolite (AgZ), silver zirconium phosphate silicate (AgZrPSi) and silver zirconium phosphate (AgZrP), against oral microorganisms. In line with this objective, the morphology and structure of each type of silver based powders were also investigated. Methods: The antimicrobial activities of AgZ, AgZrPSi and AgZrP were tested against Streptococcus mutans, Lactobacillus casei, Candidaalbicans and Staphylococcus aureus using disk diffusion assay as a screening test. The minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were determined using the modified membrane method. Scanning electron microscope and X-ray diffraction were used to investigate the morphology and structure of these silver materials. Results: All forms of silver inorganic materials could inhibit the growth of all test microorganisms. The MIC of AgZ, AgZrPSi and AgZrP was 10.0 g/L whereas MLC ranged between 10.0-60.0 g/L. In terms of morphology and structure, AgZrPSi and AgZrP had smaller sized particles (1.5-3.0 µm) and more uniformly shaped than AgZ. Conclusions: Silver inorganic materials in the form of AgZ, AgZrPSi and AgZrP had antimicrobial effects against all test oral microorganisms and those activities may be influenced by the crystal structure of carriers. These results suggest that these silver materials may be useful metals applied to oral hygiene products to provide antimicrobial activity against oral infection.

  16. Intermediates in the transformation of phosphonates to phosphate by bacteria.

    Science.gov (United States)

    Kamat, Siddhesh S; Williams, Howard J; Raushel, Frank M

    2011-11-16

    Phosphorus is an essential element for all known forms of life. In living systems, phosphorus is an integral component of nucleic acids, carbohydrates and phospholipids, where it is incorporated as a derivative of phosphate. However, most Gram-negative bacteria have the capability to use phosphonates as a nutritional source of phosphorus under conditions of phosphate starvation. In these organisms, methylphosphonate is converted to phosphate and methane. In a formal sense, this transformation is a hydrolytic cleavage of a carbon-phosphorus (C-P) bond, but a general enzymatic mechanism for the activation and conversion of alkylphosphonates to phosphate and an alkane has not been elucidated despite much effort for more than two decades. The actual mechanism for C-P bond cleavage is likely to be a radical-based transformation. In Escherichia coli, the catalytic machinery for the C-P lyase reaction has been localized to the phn gene cluster. This operon consists of the 14 genes phnC, phnD, …, phnP. Genetic and biochemical experiments have demonstrated that the genes phnG, phnH, …, phnM encode proteins that are essential for the conversion of phosphonates to phosphate and that the proteins encoded by the other genes in the operon have auxiliary functions. There are no functional annotations for any of the seven proteins considered essential for C-P bond cleavage. Here we show that methylphosphonate reacts with MgATP to form α-D-ribose-1-methylphosphonate-5-triphosphate (RPnTP) and adenine. The triphosphate moiety of RPnTP is hydrolysed to pyrophosphate and α-D-ribose-1-methylphosphonate-5-phosphate (PRPn). The C-P bond of PRPn is subsequently cleaved in a radical-based reaction producing α-D-ribose-1,2-cyclic-phosphate-5-phosphate and methane in the presence of S-adenosyl-L-methionine. Substantial quantities of phosphonates are produced worldwide for industrial processes, detergents, herbicides and pharmaceuticals. Our elucidation of the chemical steps for the

  17. Optimization of calcium phosphate fine ceramic powders preparation

    Science.gov (United States)

    Sezanova, K.; Tepavitcharova, S.; Rabadjieva, D.; Gergulova, R.; Ilieva, R.

    2013-12-01

    The effect of biomimetic synthesis method, reaction medium and further precursor treatments on the chemical and phase composition, crystal size and morphology of calcium phosphates was examined. Nanosized calcium phosphate precursors were biomimetically precipitated by the method of continuous precipitation in three types of reaction media at pH 8: (i) SBF as an inorganic electrolyte system; (ii) organic (glycerine) modified SBF (volume ratio of 1:1); (iii) polymer (10 g/l xanthan gum or 10 g/l guar gum) modified SBF (volume ratio of 1:1). After maturation (24 h) the samples were lyophilized, calcinated at 300°C for 3 hours, and washed with water, followed by new gelation, lyophilization and step-wise (200, 400, 600, 800, and 1000°C, each for 3 hours) sintering. The reaction medium influenced the chemical composition and particle size but not the morphology of the calcium phosphate powders. In all studied cases bi-phase calcium phosphate fine powders with well-shaped spherical grains, consisting of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA) with a Ca/P ratio of 1.3 - 1.6 were obtained. The SBF modifiers decreased the particle size of the product in the sequence guar gum ˜ xanthan gum < glycerin < SBF medium.

  18. Removal of nitrate and phosphate from aqueous solutions by microalgae

    Directory of Open Access Journals (Sweden)

    M.H. Sayadi

    2016-12-01

    Full Text Available The aim of this study was to evaluate the ability of microalgae Spirulina platensis and Chlorella vulgaris to remove nitrate and phosphate in aqueous solutions. Spirulina platensis and Chlorella vulgar is microalgae was collected in 1000 ml of municipal water and KNO3, K2HPO4 was added as sources of nitrate and phosphate in three different concentrations (0.25, 0.35 and 0.45g/L. During the growth period, the concentration of nitrate and phosphate was recorded at 1, 4, 6 and 8 days. The highest nitrate removal on the 8 day for Chlorella vulgaris was 89.80% at the treatment of 0.25g/L and for Spirulina platensis was 81.49% at the treatment of 0.25g/L. The highest phosphate removal for Spirulina platensis was 81.49% at the treatment of 0.45g/L and for Chlorella vulgaris was 88% at the treatment of 0.45g/L. The statistical results showed that the amount of phosphate and nitrate removal during different time periods by Chlorella vulgaris depicted a significant difference at P

  19. Amorphous calcium phosphate and its application in dentistry

    Directory of Open Access Journals (Sweden)

    Sun Wei-bin

    2011-07-01

    Full Text Available Abstract Amorphous Calcium Phosphate (ACP is an essential mineral phase formed in mineralized tissues and the first commercial product as artificial hydroxyapatite. ACP is unique among all forms of calcium phosphates in that it lacks long-range, periodic atomic scale order of crystalline calcium phosphates. The X-ray diffraction pattern is broad and diffuse with a maximum at 25 degree 2 theta, and no other different features compared with well-crystallized hydroxyapatite. Under electron microscopy, its morphological form is shown as small spheroidal particles in the scale of tenths nanometer. In aqueous media, ACP is easily transformed into crystalline phases such as octacalcium phosphate and apatite due to the growing of microcrystalline. It has been demonstrated that ACP has better osteoconductivity and biodegradability than tricalcium phosphate and hydroxyapatite in vivo. Moreover, it can increase alkaline phosphatase activities of mesoblasts, enhance cell proliferation and promote cell adhesion. The unique role of ACP during the formation of mineralized tissues makes it a promising candidate material for tissue repair and regeneration. ACP may also be a potential remineralizing agent in dental applications. Recently developed ACP-filled bioactive composites are believed to be effective anti-demineralizing/remineralizing agents for the preservation and repair of tooth structures. This review provides an overview of the development, structure, chemical composition, morphological characterization, phase transformation and biomedical application of ACP in dentistry.

  20. Bypassing the Pentose Phosphate Pathway: Towards Modular Utilization of Xylose.

    Science.gov (United States)

    Chomvong, Kulika; Bauer, Stefan; Benjamin, Daniel I; Li, Xin; Nomura, Daniel K; Cate, Jamie H D

    2016-01-01

    The efficient use of hemicellulose in the plant cell wall is critical for the economic conversion of plant biomass to renewable fuels and chemicals. Previously, the yeast Saccharomyces cerevisiae has been engineered to convert the hemicellulose-derived pentose sugars xylose and arabinose to d-xylulose-5-phosphate for conversion via the pentose phosphate pathway (PPP). However, efficient pentose utilization requires PPP optimization and may interfere with its roles in NADPH and pentose production. Here, we developed an alternative xylose utilization pathway that largely bypasses the PPP. In the new pathway, d-xylulose is converted to d-xylulose-1-phosphate, a novel metabolite to S. cerevisiae, which is then cleaved to glycolaldehyde and dihydroxyacetone phosphate. This synthetic pathway served as a platform for the biosynthesis of ethanol and ethylene glycol. The use of d-xylulose-1-phosphate as an entry point for xylose metabolism opens the way for optimizing chemical conversion of pentose sugars in S. cerevisiae in a modular fashion.

  1. [Tetany secondary to phosphate enema toxicity, case report].

    Science.gov (United States)

    Núñez Sánchez, María José; Leighton Swaneck, Sofía; Díaz, Franco

    2017-06-01

    Phosphate enemas are frequently used in the treatment of constipation. Errors in dosage and administration can lead to severe complications. To report a case of severe toxicity of phosphate enemas in a child with no risk factors. 2 years old female, with functional constipation, was brought to emergency department because abdominal pain. She was diagnosed with fecal impaction and received half a bottle of Fleet Adult® (Laboratorio Synthon, Chile) two times, with no clinical resolution, deciding to start proctoclisis in pediatric ward. Soon after admission, she presented painful tetany, but alert and oriented. Patient was transferred to PICU where severe hyperphosphatemia and secondary hypocalcemia were confirmed. Her treatment included electrolyte correction; removal of residual phosphate enema and hyperhydration. Tetany resolved over 2 hours after admission and no other complications. Proctoclisis was performed and patient was discharged three days after admission with pharmacological management of constipation. Phosphate enemas may cause serious complications in children with no risk factors. Errors in dosage, administration and removal of the enema are causes of toxicity in this group. Pediatricians and health personnel must be aware of risks and signs of toxicity of phosphate enema.

  2. Porosity prediction of calcium phosphate cements based on chemical composition.

    Science.gov (United States)

    Öhman, Caroline; Unosson, Johanna; Carlsson, Elin; Ginebra, Maria Pau; Persson, Cecilia; Engqvist, Håkan

    2015-07-01

    The porosity of calcium phosphate cements has an impact on several important parameters, such as strength, resorbability and bioactivity. A model to predict the porosity for biomedical cements would hence be a useful tool. At the moment such a model only exists for Portland cements. The aim of this study was to develop and validate a first porosity prediction model for calcium phosphate cements. On the basis of chemical reaction, molar weight and density of components, a volume-based model was developed and validated using calcium phosphate cement as model material. 60 mol% β-tricalcium phosphate and 40 mol% monocalcium phosphate monohydrate were mixed with deionized water, at different liquid-to-powder ratios. Samples were set for 24 h at 37°C and 100% relative humidity. Thereafter, samples were dried either under vacuum at room temperature for 24 h or in air at 37 °C for 7 days. Porosity and phase composition were determined. It was found that the two drying protocols led to the formation of brushite and monetite, respectively. The model was found to predict well the experimental values and also data reported in the literature for apatite cements, as deduced from the small absolute average residual errors (brushite, monetite and apatite cements. The model gives a good estimate of the final porosity and has the potential to be used as a porosity prediction tool in the biomedical cement field.

  3. The role of brushite and octacalcium phosphate in apatite formation.

    Science.gov (United States)

    Johnsson, M S; Nancollas, G H

    1992-01-01

    Studies of apatite mineral formation are complicated by the possibility of forming several calcium phosphate phases. The least soluble, hydroxyapatite (HAP), is preferentially formed under neutral or basic conditions. In more acidic solutions phases such as dicalcium phosphate dihydrate (Brushite, DCPD) and octacalcium phosphate (OCP) are often found. Even under ideal HAP precipitation conditions the precipitates are generally nonstoichiometric, suggesting the formation of calcium-deficient apatites. Both DCPD and OCP have been implicated as possible precursors to the formation of apatite. This may occur by the initial precipitation of DCPD and/or OCP followed by transformation to a more apatitic phase. Although DCPD and OCP are often detected during in vitro crystallization, in vivo studies of bone formation rarely show the presence of these acidic calcium phosphate phases. In the latter case the situation is more complicated, since a large number of ions and molecules are present that can be incorporated into the crystal lattice or adsorbed at the crystallite surfaces. In biological apatite, DCPD and OCP are usually detected only during pathological calcification where the pH is often relatively low. In normal in vivo calcifications these phases have not been found, suggesting the involvement of other precursors or the formation of an initial amorphous calcium phosphate phase (ACP) followed by transformation to apatite.

  4. Fabrication and cytocompatibility of spherical magnesium ammonium phosphate granules.

    Science.gov (United States)

    Christel, Theresa; Geffers, Martha; Klammert, Uwe; Nies, Berthold; Höß, Andreas; Groll, Jürgen; Kübler, Alexander C; Gbureck, Uwe

    2014-09-01

    Magnesium phosphate compounds, as for example struvite (MgNH4PO4·6H2O), have comparable characteristics to calcium phosphate bone substitutes, but degrade faster under physiological conditions. In the present work, we used a struvite forming calcium doped magnesium phosphate cement with the formulation Ca0.75Mg2.25(PO4)2 and an ammonium phosphate containing aqueous solution to produce round-shaped granules. For the fabrication of spherical granules, the cement paste was dispersed in a lipophilic liquid and stabilized by surfactants. The granules were characterized with respect to morphology, size distribution, phase composition, compressive strength, biocompatibility and solubility. In general, it was seen that small granules can hardly be produced by means of emulsification, when the raw material is a hydraulic paste, because long setting times promote coalescence of initially small unhardened cement droplets. Here, this problem was solved by using an aqueous solution containing both the secondary (NH4)2HPO4 and primary ammonium phosphates NH4H2PO4 to accelerate the setting reaction. This resulted in granules with 97 wt.% having a size in the range between 200 and 1,000 μm. The novel solution composition doubled the compressive strength of the cement to 37 ± 5 MPa without affecting either the conversion to struvite or the cytocompatibility using human fetal osteoblasts.

  5. Stability of Crushed Tedizolid Phosphate Tablets for Nasogastric Tube Administration.

    Science.gov (United States)

    Kennedy, Gerard; Osborn, Jim; Flanagan, Shawn; Alsayed, Najy; Bertolami, Shellie

    2015-12-01

    Tedizolid phosphate is approved for the treatment of acute bacterial skin and skin structure infections. To determine whether the expected dose of tedizolid phosphate can be delivered via nasogastric tube in patients who have difficulty swallowing and in whom venous access is not suitable, this in vitro study evaluated the recovery of tedizolid phosphate 200-mg tablets after crushing, dispersion in water, and passage through a nasogastric tube. To analyze the chemical stability of the crushed tablet dispersed in water, the aqueous preparation was assayed initially after dispersion and again after 4 h at room temperature. Recovery of tedizolid phosphate after the crushed tablets were dispersed in water and passed through nasogastric tubes ranged from 92.5 to 97.1 %, which is within the specified acceptance criteria of 90 to 110 %. There was no significant change in recovery values after 4 h of storage at room temperature (93.9 % initially and 94.7 % after 4 h). The stability and recovery findings support the feasibility of administering an aqueous dispersion of crushed tedizolid phosphate tablets through a nasogastric tube in patients who have difficulty swallowing and in whom intravenous administration is not possible.

  6. Biologically Analogous Calcium Phosphate Tubes from a Chemical Garden.

    Science.gov (United States)

    Hughes, Erik A B; Williams, Richard L; Cox, Sophie C; Grover, Liam M

    2017-02-28

    Calcium phosphate (CaPO4) tubes with features comparable to mineralized biological microstructures, such as Haversian canals, were grown from a calcium gel/phosphate solution chemical garden system. A significant difference in gel mass in response to high and low solute phosphate equivalent environments existed within 30 min of solution layering upon gel (p = 0.0067), suggesting that the nature of advective movement between gel and solution is dependent on the solution concentration. The transport of calcium cations (Ca(2+)) and phosphate anions (PO4(3-)) was quantified and changes in pH were monitored to explain the preferential formation of tubes within a PO4(3-) concentration range of 0.5-1.25 M. Ingress from the anionic solution phase into the gel followed by the liberation of Ca(2+) ions from the gel was found to be essential for acquiring self-assembled tubular CaPO4 structures. Tube analysis by scanning electron microscopy (SEM), X-ray diffraction (XRD), and micro X-ray florescence (μ-XRF) revealed hydroxyapatite (HA, Ca10(PO4)6(OH)2) and dicalcium phosphate dihydrate (DCPD, CaHPO4·2H2O) phases organized in a hierarchical manner. Notably, the tubule diameters ranged from 100 to 150 μm, an ideal size for the permeation of vasculature in biological hard tissue.

  7. Surface smoothness and marginal fit with phosphate-bonded investments.

    Science.gov (United States)

    Cooney, J P; Doyle, T M; Caputo, A A

    1979-04-01

    Two phosphate-bonded investments and one calcium sulfate investment were evaluated for the surface smoothness and marginal fit they impart to gold castings. A modified technique was also evaluated for each phosphate-bonded investment, where the silica sol was not diluted and the spatulation time was reduced. The results of this study lead to the following conclusions: 1. The marginal fits obtained with all four phosphate-bonded methods were comparable to each other and superior to that obtained with the calcium sulfate investment. 2. The presence of nodules on the surface of the castings was more prevalent with the phosphate-bonded investments. However, this effect was not statistically significant. 3. Clinical assessment of the roughness of the castings revealed that all the methods tested produced clinically acceptable castings. 4. Visual observation by five dentists revealed that both the recommended and modified techniques for one of the phosphate-bonded investments (Ceramigold) produced a smoother surface than any other investment tested. Rating of scanning electron microscope photographs (X600) revealed no difference in the surface roughness between any of the castings. Consequently, no definitive relation between investment type or technique and surface roughness was established. 5. No correlation was demonstrated between surface roughness, as evaluated by either clinical observation or scanning electron microscope photography, and marginal fit of the castings.

  8. Bypassing the Pentose Phosphate Pathway: Towards Modular Utilization of Xylose.

    Directory of Open Access Journals (Sweden)

    Kulika Chomvong

    Full Text Available The efficient use of hemicellulose in the plant cell wall is critical for the economic conversion of plant biomass to renewable fuels and chemicals. Previously, the yeast Saccharomyces cerevisiae has been engineered to convert the hemicellulose-derived pentose sugars xylose and arabinose to d-xylulose-5-phosphate for conversion via the pentose phosphate pathway (PPP. However, efficient pentose utilization requires PPP optimization and may interfere with its roles in NADPH and pentose production. Here, we developed an alternative xylose utilization pathway that largely bypasses the PPP. In the new pathway, d-xylulose is converted to d-xylulose-1-phosphate, a novel metabolite to S. cerevisiae, which is then cleaved to glycolaldehyde and dihydroxyacetone phosphate. This synthetic pathway served as a platform for the biosynthesis of ethanol and ethylene glycol. The use of d-xylulose-1-phosphate as an entry point for xylose metabolism opens the way for optimizing chemical conversion of pentose sugars in S. cerevisiae in a modular fashion.

  9. Gene Cloning of Iranian Leishmania major Mannose-1-Phosphate Guanyltransferase

    Directory of Open Access Journals (Sweden)

    R Salehi

    2009-07-01

    Full Text Available "nBackground: Leishmania is an obligatory intracellular protozoan parasite, which infects human be­ings when infected sand fly vector takes a blood meal.  Most efforts are towards designing an effective vaccine to prevent leishmaniasis. In this way, development of candidate antigen for vaccine has spe­cial im­portant. In this study, we cloned mannose-1-phosphate guanyltransferase gene of Iranian L .major in pET32a expression vector. "nMethods: Primers based on L. major mannose-1-phosphate guanyltransferase sequence gene was de­signed and synthesized. DNA of Leishmania promastigotes was extracted and PCR reaction was done. PCR product was cloned into pTZ57R and sub cloned into pET32a expression vector. "nResults: Recombinant plasmid containing 1140 bp as L. major mannose-1-phosphate guanyltrans­ferase gene was extracted and confirmed by restriction analysis. PCR product was sequenced and de­posited to GenBank. There were some differences in amino acid sequences between Iranian L. major mannose-1-phosphate guanyltransferase and others previously accepted in GenBank "nConclusion: We amplified and cloned Iranian L. major mannose-1-phosphate guanyltransferase successfully.

  10. Efficient uranium immobilization on red clay with phosphates.

    Science.gov (United States)

    Grabias, Ewelina; Gładysz-Płaska, Agnieszka; Książek, Anna; Majdan, Marek

    2014-01-01

    Uranium is a very toxic and radioactive element. Removal of uranium from wastewaters requires remediation technologies. Actual methods are costly and ineffective when uranium concentration is very low. Little is known about the enhancement of sorption of uranyl ions by phosphate ions on aluminosilicates. Here, we studied sorption of uranyl acetate on red clay in the presence of phosphates. The concentration of U(VI) ranged 0.0001-0.001 mol/L, whereas the concentration of PO4(3-) was constant at 0.0001 mol/L. We designed a new method for the analysis of ternary surface complexes. We observed for the first time a remarkable improvement of U(VI) sorption on red clay under the influence of phosphates. We also found that at least two different ternary surface complexes U(VI)-phosphate-clay are formed in the sorbent phase. The complexation of UO2(2+) cations by phosphate ligands in the sorbent phase was confirmed by the X-ray photoelectron spectra of U 4f electrons.

  11. Homogeneous Iron Phosphate Nanoparticles by Combustion of Sprays.

    Science.gov (United States)

    Rudin, Thomas; Pratsinis, Sotiris E

    2012-06-13

    Low-cost synthesis of iron phosphate nanostructured particles is attractive for large scale fortification of basic foods (rice, bread, etc.) as well as for Li-battery materials. This is achieved here by flame-assisted and flame spray pyrolysis (FASP and FSP) of inexpensive precursors (iron nitrate, phosphate), solvents (ethanol), and support gases (acetylene and methane). The iron phosphate powders produced here were mostly amorphous and exhibited excellent solubility in dilute acid, an indicator of relative iron bioavailability. The amorphous and crystalline fractions of such powders were determined by X-ray diffraction (XRD) and their cumulative size distribution by X-ray disk centrifuge. Fine and coarse size fractions were obtained also by sedimentation and characterized by microscopy and XRD. The coarse size fraction contained maghemite Fe(2)O(3) while the fine was amorphous iron phosphate. Furthermore, the effect of increased production rate (up to 11 g/h) on product morphology and solubility was explored. Using increased methane flow rates through the ignition/pilot flame of the FSP-burner and inexpensive powder precursors resulted in also homogeneous iron phosphate nanoparticles essentially converting the FSP to a FASP process. The powders produced by FSP at increased methane flow had excellent solubility in dilute acid as well. Such use of methane or even natural gas might be economically attractive for large scale flame-synthesis of nanoparticles.

  12. Mechanisms of phosphate removal from aqueous solution by blast furnace slag and steel furnace slag

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We report the adsorption of phosphate and discuss the mechanisms of phosphate removal from aqueous solution by burst furnace slag (BFS) and steel furnace slag (SFS). The results show that the adsorption of phosphate on the slag was rapid and the majority of adsorption was completed in 5~10 min. The adsorption capacity of phosphate by the slag was reduced dramatically by acid treatment. The relative contribution of adsorption to the total removal of phosphate was 26%~28%. Phosphate adsorption on BFS and SFS follows the Freundlich isotherm, with the related constants ofk 6.372 and 1/n 1.739 for BFS, and ofk 1.705 and 1/n 1.718 for SFS. The pH and Ca2+ concentration were decreased with the addition of phosphate, suggesting the formation of calcium phosphate precipitation. At pH 2.93 and 6.93, phosphate was desorbed by about 36%~43% and 9%~11%, respectively.These results indicate that the P adsorption on the slag is not completely reversible and that the bond between the slag particles and adsorbed phosphate is strong. The X-ray diffraction (XRD) patterns of BFS and SFS before and after phosphate adsorption verify SFS is related to the formation of phosphate calcium precipitation and the adsorption on hydroxylated oxides. The results show that BFS and SFS removed phosphate nearly 100%, indicating they are promising adsorbents for the phosphate removal in wastewater treatment and pollution control.

  13. A novel analytical method for in vivo phosphate tracking.

    Science.gov (United States)

    Gu, Hong; Lalonde, Sylvie; Okumoto, Sakiko; Looger, Loren L; Scharff-Poulsen, Anne Marie; Grossman, Arthur R; Kossmann, Jens; Jakobsen, Iver; Frommer, Wolf B

    2006-10-30

    Genetically-encoded fluorescence resonance energy transfer (FRET) sensors for phosphate (P(i)) (FLIPPi) were engineered by fusing a predicted Synechococcus phosphate-binding protein (PiBP) to eCFP and Venus. Purified fluorescent indicator protein for inorganic phosphate (FLIPPi), in which the fluorophores are attached to the same PiBP lobe, shows P(i)-dependent increases in FRET efficiency. FLIPPi affinity mutants cover P(i) changes over eight orders of magnitude. COS-7 cells co-expressing a low-affinity FLIPPi and a Na(+)/P(i) co-transporter exhibited FRET changes when perfused with 100 microM P(i), demonstrating concentrative P(i) uptake by PiT2. FLIPPi sensors are suitable for real-time monitoring of P(i) metabolism in living cells, providing a new tool for fluxomics, analysis of pathophysiology or changes of P(i) during cell migration.

  14. Phosphate solubilizing ability of two Arctic Aspergillus niger strains

    Directory of Open Access Journals (Sweden)

    Shiv Mohan Singh,

    2011-06-01

    Full Text Available Many filamentous fungi were isolated from the soils of Ny-Ålesund, Spitsbergen, Svalbard, and were screened in vitro for their phosphate solubilizing ability. Two strains of Aspergillus niger showed good tricalcium phosphate (TCP solubilizing ability in Pikovskaya's medium. The TCP solubilization index was calculated at varying levels of pH and temperatures. The ability of Aspergillus niger strain-1 to solubilize and release inorganic-P was 285 µg ml–1, while Aspergillus niger strain-2 solubilized 262 µg ml–1 from 0.5% TCP after seven days. This is the first report of TCP solubilization by Arctic strains that may serve as very good phosphate solubilizers in the form of biofertilizer.

  15. Uranium Extraction from Syrian Phosphate: A case Study

    Directory of Open Access Journals (Sweden)

    J.STAS, I. OTHMAN

    2010-12-01

    Full Text Available Uranium and trace elements were studied in few hundred samples from phosphatic formations in Syria. Uranium and trace elements were enriched in phosphorites facies compared to carbonate and siliceous facies. Uranium content of Syrian phosphorite by fission track method shows that uranium is related to the apatite mineral and organic matter. The concentration of uranium in phosphatic elements depends on the quality of these elements (grains, biogenic-elements. Further, uranium is relatively mobile during biomicritisation, coating and weathering. Investigation of uranium extraction from phosphoric acid produced at Homs plant (G.F.S by using phosphate concentrate from Khneifiss and Charquieh mines, have been carried out in a micro pilot and pilot plant scales. The result shows that the yield of uranium extraction from H3 PO4 is more than 95%.

  16. Cadmium extraction from phosphate ore. Effect of microwave

    Directory of Open Access Journals (Sweden)

    Zahia Benredjem

    2016-09-01

    Full Text Available This study discusses the operating variables for removal of cadmium from phosphate ore using Na2EDTA. These variables include the reaction time, Na2EDTA concentration, liquid/phosphate ore ratio, number of extractions and microwave extraction. Na2EDTA induced a two-step extraction process including a rapid extraction within the first hour, and a subsequent gradual release that occurred over the following hours. The cadmium extraction efficiency increased progressively with the increasing of Na2EDTA concentration. The extraction efficiency of cadmium increased with increasing liquid/phosphate ratio in the 5–200 range. Consecutive extractions using low concentrations were more effective than a single soil extraction with concentrated Na2EDTA. Microwave was beneficial to improve the removal in soil washing, and using microwave could partly substitute for agitation.

  17. Calcium-phosphate-osteopontin particles for caries control

    DEFF Research Database (Denmark)

    Schlafer, Sebastian

    Oftentimes caries lesions develop in protected sites that are difficult to access by self-performed mechanical tooth cleaning. At present, there is a growing interest in chemical adjuncts to mechanical procedures of oral hygiene that aim at biofilm control rather than biofilm eradication. Calcium......-phosphate-osteopontin particles are a new promising therapeutic approach to caries control. They are designed to bind to dental biofilms and interfere with biofilm build-up, lowering the bacterial burden on the tooth surface without affecting bacterial viability in the oral cavity. Moreover, they dissolve when pH in the biofilm...... drops to 6 or below and release buffering phosphate ions that stabilize biofilm pH above the critical level for enamel dissolution. With that twofold approach, calcium-phosphate-osteopontin particles may make a relevant contribution to clinical caries control....

  18. Non-Isothermal Calcination Kinetics of Phosphate Rock

    Directory of Open Access Journals (Sweden)

    Hatice Bayrakçeken

    2014-07-01

    Full Text Available The kinetics of thermal decomposition of the phosphate rock was studied by means of thermal analysis techniques (TG/DTG in inert nitrogen (N2 atmosphere at heating rates of 2, 5, 10, and 20 K min-1. TG and DTG measurements indicated that calcination of the phosphate rock has single-stage degradation in between 873-1173 K. Kissinger–Akahira–Sunose (KAS and Flynn-Wall-Ozawa (FWO isoconversional methods were applied to the data obtained from TG and DTG curves and the activation energies were found as 170 ve 187 kJmol-1, respectively. It was determined that the thermal decomposition mechanism of phosphate rock was occurred via nucleation and growth (-ln(1-α2/3 mechanism. Pre-exponentional factor (lnA was determined as 20.47.

  19. Characterization of iron-phosphate-silicate chemical garden structures.

    Science.gov (United States)

    Barge, Laura M; Doloboff, Ivria J; White, Lauren M; Stucky, Galen D; Russell, Michael J; Kanik, Isik

    2012-02-28

    Chemical gardens form when ferrous chloride hydrate seed crystals are added or concentrated solutions are injected into solutions of sodium silicate and potassium phosphate. Various precipitation morphologies are observed depending on silicate and phosphate concentrations, including hollow plumes, bulbs, and tubes. The growth of precipitates is controlled by the internal osmotic pressure, fluid buoyancy, and membrane strength. Additionally, rapid bubble-led growth is observed when silicate concentrations are high. ESEM/EDX analysis confirms compositional gradients within the membranes, and voltage measurements across the membranes during growth show a final potential of around 150-200 mV, indicating that electrochemical gradients are maintained across the membranes as growth proceeds. The characterization of chemical gardens formed with iron, silicate, and phosphate, three important components of an early earth prebiotic hydrothermal system, can help us understand the properties of analogous structures that likely formed at submarine alkaline hydrothermal vents in the Hadean-structures offering themselves as the hatchery of life.

  20. Renal control of calcium, phosphate, and magnesium homeostasis.

    Science.gov (United States)

    Blaine, Judith; Chonchol, Michel; Levi, Moshe

    2015-07-01

    Calcium, phosphate, and magnesium are multivalent cations that are important for many biologic and cellular functions. The kidneys play a central role in the homeostasis of these ions. Gastrointestinal absorption is balanced by renal excretion. When body stores of these ions decline significantly, gastrointestinal absorption, bone resorption, and renal tubular reabsorption increase to normalize their levels. Renal regulation of these ions occurs through glomerular filtration and tubular reabsorption and/or secretion and is therefore an important determinant of plasma ion concentration. Under physiologic conditions, the whole body balance of calcium, phosphate, and magnesium is maintained by fine adjustments of urinary excretion to equal the net intake. This review discusses how calcium, phosphate, and magnesium are handled by the kidneys.

  1. Calcium-phosphate-osteopontin particles for caries control

    DEFF Research Database (Denmark)

    Schlafer, Sebastian; Birkedal, Henrik; Olsen, Jakob

    2016-01-01

    Caries is caused by acid production in biofilms on dental surfaces. Preventing caries therefore involves control of microorganisms and/or the acid produced. Here, calcium-phosphate-osteopontin particles are presented as a new approach to caries control. The particles are made by co......-precipitation and designed to bind to bacteria in biofilms, impede biofilm build-up without killing the microflora, and release phosphate ions to buffer bacterial acid production if the pH decreases below 6. Analysis of biofilm formation and pH in a five-species biofilm model for dental caries showed that treatment......H always remained above 5.5. Hence, calcium-phosphate-osteopontin particles show potential for applications in caries control....

  2. Dihydrogen Phosphate Selective Anion Receptor Based on Acylhydrazone

    Energy Technology Data Exchange (ETDEWEB)

    Senthil Pandian, T.; Kang, Jongmin [Sejong Univ., Seoul (Korea, Republic of)

    2014-07-15

    Anion receptor based on acylhydrazone has been designed and synthesized. UV-vis and {sup 1}H NMR titration showed that receptor is selective receptor for dihydrogen phosphate (H{sub 2}PO{sub 4}{sup -}). Dihydrogen phosphate was complexed by the receptor via at least 4 hydrogen bonding interactions, contributing from two amide N-Hs and two imine C-Hs. In addition, nitrogen in the aromatic ring could make 2 additional hydrogen bondings with OH groups in the dihydrogen phosphate. However, the receptor could make only 4 hydrogen bonds with halides. Therefore, receptor could bind anions through hydrogen bonds with a selectivity in the order of H{sub 2}PO{sub 4}{sup -} > Br{sup -} > Cl{sup -} in highly polar solvent such as DMSO.

  3. Gain Characteristics of Er3+-Doped Phosphate Glass Fibres

    Institute of Scientific and Technical Information of China (English)

    XU Shan-Hui; YANG Zhong-Min; ZHANG Qin-Yuan; DENG Zai-De; JIANG Zhong-Hong

    2006-01-01

    @@ An erbium-doped phosphate glass fibre has been drawn by the rod-in-tube technique in our laboratory. The gain for the Er3+-doped phosphate glass fibre with different pump powers and with different input signal wavelengths is investigated. The 2.2-cm-long fibre, pumped by a single-mode 980-nm fibre-pigtailed laser diode, can provide a net gain per unit length greater than 1.8dB/cm. The pump threshold is about 50mW at the wavelength of 1534nm, and below 70mW at 1550nm. The gain linewidth of the Er3+-doped phosphate glass fibre is greater than 34 nm and can cover the C band in optical communication networks.

  4. ION EXCHANGE SUBSTANCES BY SAPONIFICATION OF ALLYL PHOSPHATE POLYMERS

    Science.gov (United States)

    Kennedy, J.

    1959-04-14

    An ion exchange resin having a relatively high adsorption capacity tor uranyl ion as compared with many common cations is reported. The resin comprises an alphyl-allyl hydrogen phosphate polymer, the alphyl group being either allyl or a lower alkyl group having up to 5 carbon atoins. The resin is prepared by polymerizing compounds such as alkyl-diallyl phosphate and triallyl phosphate in the presence of a free radical generating substance and then partially hydrolyzing the resulting polymer to cause partial replacement of organic radicals by cations. A preferred free radical gencrating agent is dibenzoyl peroxide. The partial hydrolysis is brought about by refluxing the polymer with concentrated aqueous NaOH for three or four hours.

  5. Revegetation of serpentine substrates: Response to phosphate application

    Science.gov (United States)

    Koide, Roger T.; Mooney, Harold A.

    1987-08-01

    Revegetation was studied on stockpiled serpentine substrate. The native vegetation surrounding the revegetation site is annual grassland. The seed mixture applied to both subsoil and topsoil plots was largely ineffective for revegetation. No growth occurred in the subsoil plots and most of the growth in the topsoil plots was from indigenous seed. Phosphate application (100 kg P ha-1 as NaH2PO4 · H2O) to the topsoil plots resulted in a significant increase in total above-ground productivity. Annual legumes (mostly Lotus subpinnatus Lag.) and, to a lesser degree, Plantago erecta Morris responded to the added phosphate with an increased above-ground productivity. Other annual forbs and annual grasses showed no significant response. The legumes also increased in abundance. Mycorrhizal root colonization for Plantago was not significantly affected by phosphate application, but was lower in this disturbed serpentine site compared to other undisturbed serpentine annual grassland sites nearby.

  6. Natural radioactivity assessment of a phosphate fertilizer plant area

    Directory of Open Access Journals (Sweden)

    S.K. Sahu

    2014-01-01

    Full Text Available Rock phosphate ore processing and disposal of phosphogypsum contribute to enhanced levels of natural radionuclides in the environment. The concentration of naturally occurring radionuclides in soil, rock phosphate and phosphogypsum samples collected around a phosphate fertilizer plant were determined. Also the external background gamma levels were surveyed.238U, 232Th, 226Ra and 40K activities in soil samples were 21–674 Bq/kg, 11–44 Bq/kg, 22–683 Bq/kg and 51–295 Bq/kg respectively. The external background gamma radiation levels in the plant premises were ranging from 48 to 133 nGy/h.

  7. Formation of calcium phosphate mineral materialcontrolled by microemulsion

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to prepare calcium phosphate-based material with nano-structure and bioactivity, natural lecithin and n-tetradecane were used as the amphipile and the oil phase respectively, along with the water phase, to form a microemulsion template. Phosphate mineralization was induced and controlled by the microemulsion. The products, characterized by scanning electronic microscopy, infrared spectroscopy and X-ray diffraction analysis, are composed of lecithin and hydroxyapatite, and possess the nano-structure of sticks, balls and three-dimensional nets connected by tubes. These results show that the microemulsion can be used to control calcium phosphate mineralization for the preparation of biomimetic mineral materials with various nano-structures.

  8. Teratogenicity studies of alkylaryl phosphate ester plasticizers in rats.

    Science.gov (United States)

    Robinson, E C; Hammond, B G; Johannsen, F R; Levinskas, G J; Rodwell, D E

    1986-07-01

    Santicizer 141 plasticizer (2-ethylhexyldiphenyl phosphate) and Santicizer 148 plasticizer (isodecyldiphenyl phosphate) were tested for teratogenic activity in Charles River COBS CD rats. Groups of 25 mated females were given 0, 300, 1000, or 3000 mg/kg/day by gavage on Days 6 through 15 (Santicizer 141) or 6 through 19 (Santicizer 148) of gestation. Mean maternal body weight gains were slightly and severely reduced at the mid- and high-dose levels of Santicizer 141, respectively. Body weights were not affected by treatment with Santicizer 148. Most malformations found in groups treated with either plasticizer occurred as single incidences and have been observed in historical controls. Thus, no teratogenic response was observed in rats after treatment with either of these two alkylaryl phosphates during the period of organogenesis.

  9. Associations between calcium-phosphate metabolism and coronary artery calcification

    DEFF Research Database (Denmark)

    Grønhøj, Mette H; Gerke, Oke; Mickley, Hans;

    2016-01-01

    calcium-phosphate metabolism is associated with the presence and extent of coronary artery calcification (CAC) in asymptomatic and apparently healthy individuals. METHODS: Serum samples from 1088 randomly recruited middle-aged men and women without known CVD and diabetes (DM), from the general population......, were analysed for total calcium, phosphate, parathyroid hormone (PTH) and 25-hydroxyvitamin D (25(OH)D). CAC was measured by a non-contrast cardiac CT scan and categorised into four groups: 0, 1-99, 100-399, ≥400 Agatston units. The association of calcium-phosphate metabolism with CAC was evaluated......)D values were placed within the normal range. In men, the odds of being in a higher CAC category, i.e. having more severe CAC, increased by 30% when serum calcium concentration increased by 0.1 mmol/l (95% CI: 1.04-1.61, p = 0.019), independently of traditional cardiovascular risk factors. In women...

  10. Phosphate-intercalated Ca-Fe-layered double hydroxides: Crystal structure, bonding character, and release kinetics of phosphate

    Science.gov (United States)

    Woo, Myong A.; Woo Kim, Tae; Paek, Mi-Jeong; Ha, Hyung-Wook; Choy, Jin-Ho; Hwang, Seong-Ju

    2011-01-01

    The nitrate-form of Ca-Fe-layered double hydroxide (Ca-Fe-LDH) was synthesized via co-precipitation method, and its phosphate-intercalates were prepared by ion-exchange reaction. According to X-ray diffraction analysis, the Ca-Fe-LDH-NO 3- compound and its H 2PO 4--intercalate showed hexagonal layered structures, whereas the ion-exchange reaction with HPO 42- caused a frustration of the layer ordering of LDH. Fe K-edge X-ray absorption spectroscopy clearly demonstrated that the Ca-Fe-LDH lattice with trivalent iron ions was well-maintained after the ion-exchange with HPO 42- and H 2PO 4-. Under acidic conditions, phosphate ions were slowly released from the Ca-Fe-LDH lattice and the simultaneous release of hydroxide caused the neutralization of acidic media. Fitting analysis based on kinetic models indicated a heterogeneous diffusion process of phosphates and a distinct dependence of release rate on the charge of phosphates. This study strongly suggested that Ca-Fe-LDH is applicable as bifunctional vector for slow release of phosphate fertilizer and for the neutralization of acid soil.

  11. Inducing Mineral Precipitation in Groundwater by Addition of Phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Karen E. Wright; Yoshiko Fujita; Thomas Hartmann; Mark Conrad

    2011-10-01

    Induced precipitation of phosphate minerals to scavenge trace metals and radionuclides from groundwater is a potential remediation approach for contaminated aquifers. Phosphate minerals can sequester trace elements by primary mineral formation, solid solution formation and/or adsorption, and they are poorly soluble under many environmental conditions, making them attractive for long-term sustainable remediation. The success of such engineered schemes will depend on the particular mineral phases generated, their rates of formation, and their long term stability. The purpose of this study was to examine the precipitation of calcium phosphate minerals under conditions representative of a natural groundwater. Because microorganisms are present in groundwater, and because some proposed schemes for induced phosphate mineral precipitation rely on the stimulation of native groundwater populations, we also tested the effect of bacterial cells (initial densities of 105 and 107 ml-1) within the precipitation medium. We also tested the effect of a trace mixture of propionic, isovaleric, formic and butyric acids (total concentration 0.035 mM). The experiments showed that the general progression of mineral precipitation was similar under all of the conditions, with initial formation of amorphous calcium carbonate, and transformation to poorly crystalline hydroxyapatite (HAP) by the end of the week-long experiments. The presence of the bacterial cells appeared to delay precipitation, although by the end of 7 days the overall extent of precipitation was similar for all of the treatments. The stoichiometry of the final precipitates as well as results of Rietveld refinement of x-ray diffraction data indicated that the treatments including organic acids and bacterial cells resulted in increased distortion of the HAP crystal lattice, with the higher concentration of cells resulting in the greatest distortion. Uptake of Sr into the phosphate minerals was decreased in the treatments

  12. Phosphate-Modified Nucleotides for Monitoring Enzyme Activity.

    Science.gov (United States)

    Ermert, Susanne; Marx, Andreas; Hacker, Stephan M

    2017-04-01

    Nucleotides modified at the terminal phosphate position have been proven to be interesting entities to study the activity of a variety of different protein classes. In this chapter, we present various types of modifications that were attached as reporter molecules to the phosphate chain of nucleotides and briefly describe the chemical reactions that are frequently used to synthesize them. Furthermore, we discuss a variety of applications of these molecules. Kinase activity, for instance, was studied by transfer of a phosphate modified with a reporter group to the target proteins. This allows not only studying the activity of kinases, but also identifying their target proteins. Moreover, kinases can also be directly labeled with a reporter at a conserved lysine using acyl-phosphate probes. Another important application for phosphate-modified nucleotides is the study of RNA and DNA polymerases. In this context, single-molecule sequencing is made possible using detection in zero-mode waveguides, nanopores or by a Förster resonance energy transfer (FRET)-based mechanism between the polymerase and a fluorophore-labeled nucleotide. Additionally, fluorogenic nucleotides that utilize an intramolecular interaction between a fluorophore and the nucleobase or an intramolecular FRET effect have been successfully developed to study a variety of different enzymes. Finally, also some novel techniques applying electron paramagnetic resonance (EPR)-based detection of nucleotide cleavage or the detection of the cleavage of fluorophosphates are discussed. Taken together, nucleotides modified at the terminal phosphate position have been applied to study the activity of a large diversity of proteins and are valuable tools to enhance the knowledge of biological systems.

  13. The geology of the Florida land-pebble phosphate deposits

    Science.gov (United States)

    Cathcart, J.B.; Blade, L.V.; Davidson, D.F.; Ketner, K.B.

    1952-01-01

    The land-pebble phosphate district is on the Gulf Coastal Plain of Florida. The phosphate deposits are in the Bone Valley formation, dated Pliocene by most writers. These strata overlie the Miocene Hawthorn formation and are overlain by consolidated sands 3 to 20 feet thick. The minable phosphate deposits, called “matrix” in the district, range from a featheredge to about 50 feet in thickness and consist of phosphatic pellets and nodules, quartz sand, and montmorillonitic clay in about equal proportions. Locally the matrix displays cross-bedding and horizontal laminations, but elsewhere it is structureless. The phosphorite particles, composed largely of carbonate-fluorapatite, range in diameter from less than 0.1 mm to about 60 cm and in P2O5 content from 30 to 36 percent. Coarse-pebble deposits, containing 30 to 34 percent P2O5 are found mainly on basement highs; and fine-pebble deposits, containing 32 to 36 percent P2O5 are, are found in basement lows. Deposits in the northern part of the field contain more phosphate particles and their P2O5 content is higher than those in the southern part. The upper part of the phosphatic strata is leached to an advanced degree and consists of quartz sand and clay-sized particules of pseudowavellite and wavellite. The leached zone ranges in thickness from a featheredge to 60 feet. The origin of the land-pebble deposits is incompletely known. Possible modes of origin are a residuum of Miocene age, or a reworked residuum of Pliocene or Quaternary age.

  14. Interaction between Nitrogen and Phosphate Stress Responses in Sinorhizobium meliloti

    Directory of Open Access Journals (Sweden)

    Kelly Lynn Hagberg

    2016-11-01

    Full Text Available Bacteria have developed various stress response pathways to improve their assimilation and allocation of limited nutrients, such as nitrogen and phosphate. While both the Nitrogen Stress Response (NSR and Phosphate Stress Response (PSR have been studied individually, there are few experiments reported that characterize effects of multiple stresses on one or more pathways in Sinorhizobium meliloti, a facultatively symbiotic, nitrogen-fixing bacteria. The PII proteins, GlnB and GlnK, regulate the NSR activity, but analysis of global transcription changes in a PII deficient mutant suggest that the S. meliloti PII proteins may also regulate the PSR. PII double deletion mutants grow very slowly and pseudoreversion of the slow growth phenotype is common. To understand this phenomenon better, transposon mutants were isolated that had a faster growing phenotype. One mutation was in phoB, the response regulator for a two component regulatory system that is important in the PSR. phoB::Tn5 mutants had different phenotypes in the wild type compared to a PII deficient background. This led to the hypothesis that phosphate stress affects the NSR and conversely, that nitrogen stress affects the PSR. Our results show that phosphate availability affects glutamine synthetase activity and expression, which are often used as indicators of NSR activity, but that nitrogen availability did not affect alkaline phosphatase activity and expression, which are indicators of PSR activity. We conclude that the NSR is co-regulated by nitrogen and phosphate, whereas the PSR does not appear to be co-regulated by nitrogen in addition to its known phosphate regulation.

  15. Interaction between Nitrogen and Phosphate Stress Responses in Sinorhizobium meliloti

    Science.gov (United States)

    Hagberg, Kelly L.; Yurgel, Svetlana N.; Mulder, Monika; Kahn, Michael L.

    2016-01-01

    Bacteria have developed various stress response pathways to improve their assimilation and allocation of limited nutrients, such as nitrogen and phosphate. While both the nitrogen stress response (NSR) and phosphate stress response (PSR) have been studied individually, there are few experiments reported that characterize effects of multiple stresses on one or more pathways in Sinorhizobium meliloti, a facultatively symbiotic, nitrogen-fixing bacteria. The PII proteins, GlnB and GlnK, regulate the NSR activity, but analysis of global transcription changes in a PII deficient mutant suggest that the S. meliloti PII proteins may also regulate the PSR. PII double deletion mutants grow very slowly and pseudoreversion of the slow growth phenotype is common. To understand this phenomenon better, transposon mutants were isolated that had a faster growing phenotype. One mutation was in phoB, the response regulator for a two component regulatory system that is important in the PSR. phoB::Tn5 mutants had different phenotypes in the wild type compared to a PII deficient background. This led to the hypothesis that phosphate stress affects the NSR and conversely, that nitrogen stress affects the PSR. Our results show that phosphate availability affects glutamine synthetase activity and expression, which are often used as indicators of NSR activity, but that nitrogen availability did not affect alkaline phosphatase activity and expression, which are indicators of PSR activity. We conclude that the NSR is co-regulated by nitrogen and phosphate, whereas the PSR does not appear to be co-regulated by nitrogen in addition to its known phosphate regulation. PMID:27965651

  16. Phosphate and iron limitation of phytoplankton biomass in Lake Tahoe

    Science.gov (United States)

    Chang, Cecily C.Y.; Kuwabara, J.S.; Pasilis, S.P.

    1992-01-01

    Bioassays were carried out to assess the response of inoculated, single-species diatom populations (Cyclotella meneghiniana and Aulocosiera italica) to additions of synthetic chelators and phosphate. A chemical speciation model along with the field data was also used to predict how trace metal speciation, and hence bioavailability, was affected by the chelator additions. Results suggest that phosphate was limiting to phytoplankton biomass. Other solutes, Fe in particular, may also exert controls on biomass. Nitrate limitation seems less likely, although Fe-limiting conditions may have led to an effective N limitation because algae require Fe to carry out nitrate reduction. -from Authors

  17. Cost of phosphate removal in municipal wastewater treatment plants

    Science.gov (United States)

    Schuessler, H.

    1983-01-01

    Construction and operating costs of advanced wastewater treatment for phosphate removal at municipal wastewater treatment plants have been investigated on orders from the Federal Environmental Bureau in Berlin. Particular attention has been paid to applicable kinds of precipitants for pre-, simultaneous and post-precipitation as well as to different phosphate influent and effluent concentrations. The article offers detailed comments on determination of technical data, investments, capital costs, operating costs and annual costs as well as potential cost reductions resulting from precipitation. Selected results of the cost investigation are shown in graphical form as specific investments, operating and annual costs depending on wastewater flow.

  18. Investigation of k-struvite formation in magnesium phosphate cements

    OpenAIRE

    LE ROUZIC, Mathieu; Chaussadent, Thierry; Stefan, Lavinia; PLATRET, Gérard

    2014-01-01

    Magnesium phosphate cements can be used as an alternative of Portland cements for the stabilization/solidification (S/S) process of specific wastes like mercury, lead, … These cements are based on the reaction between magnesium oxide (MgO) and monopotassium phosphate (KH2PO4) mixed with water which leads to the formation of the solid skeleton of the matrix: MgO + KH2PO4 + 5H2O  MgKPO4.6H2O. The development of k-struvite crystals (MgKPO4.6H2O) leads to the setting of these ...

  19. Phosphate Nd:glass materials for femtosecond pulse generation

    Science.gov (United States)

    Agnesi, Antonio; Carrà, Luca; Reali, Giancarlo

    2008-08-01

    Two different phosphate Nd-doped glasses have been investigated in a diode-pumped femtosecond laser. To our knowledge, only Schott's phosphate glasses were previously used in femtosecond oscillators. A slightly different behaviour was observed in our experiments, with respect to earlier reports: clean sech 2-pulses with duration <400 fs were routinely generated with wavelength corresponding to the fluorescence peak ≈1054 nm, whereas shorter pulses occurred at red-shifted wavelengths near 1067 nm. With a single 1-W pump diode (broad area emitter), cw slope efficiency as high as 32% and 139-fs pulse generation were demonstrated.

  20. Tin-phosphate glass anode for sodium ion batteries

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Honma

    2013-11-01

    Full Text Available The electrochemical property of tin-phosphate (designate as GSPO glass anode for the sodium ion battery was studied. During the first charge process, sodium ion diffused into GSPO glass matrix and due to the reduction of Sn2+ to Sn0 state sodiated tin metal nano-size particles are formed in oxide glass matrix. After the second cycle, we confirmed the steady reversible reaction ∼320 mAh/g at 0–1 V cutoff voltage condition by alloying process in NaxSn4. The tin-phosphate glass is a promising candidate of new anode active material that realizes high energy density sodium ion batteries.

  1. Mechanical properties of tricalcium phosphate-alumina composites

    Science.gov (United States)

    Sakka, S.; Ben Ayed, F.; Bouaziz, J.

    2012-02-01

    Tricalcium phosphate and alumina powder were mixed in order to elaborate biphasic ceramics composites. This study deals to produce bioceramics composites sintered at various temperatures for differents times. The characterization of samples, before and after the sintering process was investigated, using X-Ray diffraction, scanning electronic microscopy, 31P and 27Al nuclear magnetic resonance and differential thermal analysis. Mechanical properties of biphasic composites were studied using Brazilian test. The tricalcium phosphate - 75 wt% alumina composites mechanical resistance increased with sintered temperature. The mechanical resistance reach it's optimum value (8.6 MPa) at 1550°C for two hours.

  2. Vitrified chemically bonded phosphate ceramics for immobilization of radioisotopes

    Science.gov (United States)

    Wagh, Arun S.

    2016-04-05

    A method of immobilizing a radioisotope and vitrified chemically bonded phosphate ceramic (CBPC) articles formed by the method are described. The method comprises combining a radioisotope-containing material, MgO, a source of phosphate, and optionally, a reducing agent, in water at a temperature of less than 100.degree. C. to form a slurry; curing the slurry to form a solid intermediate CBPC article comprising the radioisotope therefrom; comminuting the intermediate CBPC article, mixing the comminuted material with glass frits, and heating the mixture at a temperature in the range of about 900 to about 1500.degree. C. to form a vitrified CBPC article comprising the radioisotope immobilized therein.

  3. Influence of glyphosate on the copper dissolution in phosphate buffer

    Science.gov (United States)

    Coutinho, C. F. B.; Silva, M. O.; Machado, S. A. S.; Mazo, L. H.

    2007-01-01

    The electrochemical behavior of copper microelectrode in phosphate buffer in the presence of glyphosate was investigated by electrochemical techniques. It was observed that the additions of glyphosate in the phosphate buffer increased the anodic current of copper microelectrode and the electrochemical dissolution was observed. This phenomenon could be associated with the Cu(II) complexation by glyphosate forming a soluble complex. Physical characterization of the surface showed that, in absence of glyphosate, an insoluble layer covered the copper surface; on the other hand, in presence of glyphosate, it was observed a corroded copper surface with the formation of glyphosate complex in solution.

  4. The radiological impact of the Belgian phosphate industry

    Energy Technology Data Exchange (ETDEWEB)

    Vanmarcke, H.; Paridaens, J. [Belgian Nuclear Research Centre, SCK.CEN, Boeretang 200, 2400 Mol (Belgium)

    2006-07-01

    The Belgian phosphate industry processes huge amounts of phosphate ore (1.5 to 2 Mton/year) for a wide range of applications, the most important being the production of phosphoric acid, fertilizers and cattle food. Marine phosphate ores show high specific activities of the natural uranium decay series (usually indicated by Ra-226) (e.g. 1200 to 1500 Bq/kg for Moroccan ore). Ores of magmatic origin generally contain less of the uranium and more of the thorium decay series (up to 500 Bq/kg). These radionuclides turn up in by-products, residues or product streams depending on the processing method and the acid used for the acidulation of the phosphate rock. Sulfuric acid is the most widely used, but also hydrochloric acid and nitric acid are applied in Belgium. For Flanders, the northern part of Belgium, we already have a clear idea of the production processes and waste streams. The five Flemish phosphate plants, from 1920 to 2000, handled 54 million ton of phosphate ore containing 65 TBq of radium-226 and 2.7 TBq of thorium- 232. The total surface area of the phosphogypsum and calcium fluoride sludge deposits amounts to almost 300 ha. There is also environmental contamination along two small rivers receiving the waste waters of the hydrochloric production process: the Winterbeek (> 200 ha) and the Grote Laak (12 ha). The data on the impact of the phosphate industry in the Walloon provinces in Belgium is less complete. A large plant produced in 2004 0.8 Mton of phosphogypsum, valorizing about 70 % of the gypsum in building materials (plaster, cement), in fertilizers, and in other products such as paper. The remainder was stored on a local disposal site. The radiological impact of the Belgian phosphate industry on the local population will be discussed. At present most contaminated areas are still recognizable as waste deposits and inaccessible to the population. However as gypsum deposits and other contaminated areas quickly blend in with the landscape, it is

  5. Essential fructosuria: increased levels of fructose 3-phosphate in erythrocytes.

    Science.gov (United States)

    Petersen, A; Steinmann, B; Gitzelmann, R

    1992-01-01

    Erythrocytes of 3 adult siblings with essential fructosuria contained 45-200 mumol/l fructose 3-phosphate (Fru-3-P), i.e. 3-15 times the concentration in normal controls. Sorbitol 3-phosphate was also increased, but to a lesser degree. An oral load with 50 g of fructose produced an additional 40 mumol/l increase of erythrocyte Fru-3-P after 5 h. The rate of Fru-3-P formation by red cells in vitro was normal. HbA1 and HbA1c were normal. The suspected pathogenetic role of Fru-3-P in diabetic complications is questioned.

  6. THERMODINAMIC PARAMETERS ON THE SORPTION OF PHOSPHATE IONS BY MONTMORILLONITE

    Directory of Open Access Journals (Sweden)

    Ikhsan Jaslin

    2016-04-01

    Full Text Available The sorption of phosphate by montmorillonite at 10, 30, and 50 oC were investigated aiming to mainly determine thermodynamic parameters for the formation of surface complexes in the adsorption of phosphate ions by montmorillonite. Data were collected by adsorption edge experiments investigating the effect of pH, adsorption isotherms enabling the effect of sorbate concentration, and acid-base titration calculating protons released or taken up by adsorption process. Data analysis was carried out using surface complexation model to fit the data collected in this study using the parameters obtained from previous study, as well as to calculate the values of ΔH and ΔS. Previous study reported that phosphate ions formed two outer-sphere surface complexes with active sites of montmorillonite through hydrogen bonding. In the first complex,  [(XH0– H2L─]─, the phosphate was held to permanent-charge X─ sites on the tetrahedral siloxane faces, and the second complex, [[(SO─(SOH]– – [H2L]─] 2─ was formed through the interaction between the phosphate and variable charge surface hydroxyl groups at the edges of montmorillonite crystals and on the octahedral alumina faces. The values of ΔH for the first and second reactions are 39.756 and 3.765x10-7 kJ mol‒1 respectively. Since both reactions have positive enthalpy values, it can be concluded that the reactions are endothermic. Large energy for the first reaction is needed by X─  sites (permanent negatively charge sites of montmorillonite to be partially desolvated, on which K+ or other surface cations are replaced by H+ ions in the surface protonated process, and are then ready to interact phosphate ions in the solution. Small values of ΔH for the second reactions indicates that hydrogen bonds formed by phosphate and SOH sites in the second reaction are easily broken out, and the phosphate can easily desorbed from the surface. The values of ΔS for the first and second reactions are

  7. The ferroxidase center is essential for ferritin iron loading in the presence of phosphate and minimizes side reactions that form Fe(III)-phosphate colloids.

    Science.gov (United States)

    Hilton, Robert J; David Andros, N; Watt, Richard K

    2012-04-01

    Ferritin iron loading was studied in the presence of physiological serum phosphate concentrations (1 mM), elevated serum concentrations (2-5 mM), and intracellular phosphate concentrations (10 mM). Experiments compared iron loading into homopolymers of H and L ferritin with horse spleen ferritin. Prior to studying the reactions with ferritin, a series of control reactions were performed to study the solution chemistry of Fe(2+) and phosphate. In the absence of ferritin, phosphate catalyzed Fe(2+) oxidation and formed soluble polymeric Fe(III)-phosphate complexes. The Fe(III)-phosphate complexes were characterized by electron microscopy and atomic force microscopy, which revealed spherical nanoparticles with diameters of 10-20 nm. The soluble Fe(III)-phosphate complexes also formed as competing reactions during iron loading into ferritin. Elemental analysis on ferritin samples separated from the Fe(III)-phosphate complexes showed that as the phosphate concentration increased, the iron loading into horse ferritin decreased. The composition of the mineral that does form inside horse ferritin has a higher iron/phosphate ratio (~1:1) than ferritin purified from tissue (~10:1). Phosphate significantly inhibited iron loading into L ferritin, due to the lack of the ferroxidase center in this homopolymer. Spectrophotometric assays of iron loading into H ferritin showed identical iron loading curves in the presence of phosphate, indicating that the ferroxidase center of H ferritin efficiently competes with phosphate for the binding and oxidation of Fe(2+). Additional studies demonstrated that H ferritin ferroxidase activity could be used to oxidize Fe(2+) and facilitate the transfer of the Fe(3+) into apo transferrin in the presence of phosphate.

  8. Determination of 14 monoalkyl phosphates, dialkyl phosphates and dialkyl thiophosphates by LC-MS/MS in human urinary samples.

    Science.gov (United States)

    Reemtsma, Thorsten; Lingott, Jana; Roegler, Stefanie

    2011-04-15

    Human urine was analyzed for nine dialkyl (DAP) and five monoalkyl phosphates (MAP) by LC-MS/MS. Some phosphoric acid esters are industrial chemicals and other hydrolysis products of trialkyl or triaryl phosphates, used as pesticides, flame retardants or plasticizers. Five MAP and two DAP were detected here for the first time in human urine. Monobutyl, diethyl, diphenyl and diethylhexyl phosphate were determined with median concentrations in the μg/L-range. The total urinary concentration of the 14 DAP and MAP summed up to a median of 20μg/L. Inclusion of MAP in future biomonitoring studies should provide a more comprehensive picture of the exposure of humans to organophosphorus compounds.

  9. Studies on the inhibition of sphingosine-1-phosphate lyase by stabilized reaction intermediates and stereodefined azido phosphates.

    Science.gov (United States)

    Sanllehí, Pol; Abad, José-Luís; Bujons, Jordi; Casas, Josefina; Delgado, Antonio

    2016-11-10

    Two kinds of inhibitors of the PLP-dependent enzyme sphingosine-1-phosphate lyase have been designed and tested on the bacterial (StS1PL) and the human (hS1PL) enzymes. Amino phosphates 1, 12, and 32, mimicking the intermediate aldimines of the catalytic process, were weak inhibitors on both enzyme sources. On the other hand, a series of stereodefined azido phosphates, resulting from the replacement of the amino group of the natural substrates with an azido group, afforded competitive inhibitors in the low micromolar range on both enzyme sources. This similar behavior represents an experimental evidence of the reported structural similarities for both enzymes at their active site level. Interestingly, the anti-isomers of the non-natural enantiomeric series where the most potent inhibitors on hS1PL.

  10. A study of the inhibiton of copper corrosion by triethyl phosphate and triphenyl phosphate self-assembled monolayers

    Directory of Open Access Journals (Sweden)

    HOUYI MA

    2006-02-01

    Full Text Available Two kinds of phosphates, triethyl phosphate (TEP and triphenyl phosphate (TPP, were used to form self-assembled monolayers for the inhibition of the corrosion of copper in 0.2 mol dm–3 NaCl solution. Electrochemical impedance spectroscopy (EIS was applied to investigate the inhibition effects. The results showed that their inhibition ability first increased with increasing immersion time in ethanolic solutions of the corresponding compounds. However, when the immersion time was increased over some critical point, the inhibition effect decreased. For the same immersion time, the inhibition effect of the TPP monolayer was more pronounced than that of the TEP monolayer. Thus, ab initio calculations were used to interpret the relationship between the inhibition effects and the structures of the compounds.

  11. Luminal fructose inhibits rat intestinal sodium-phosphate cotransporter gene expression and phosphate uptake24

    Science.gov (United States)

    Kirchner, Séverine; Muduli, Anjali; Casirola, Donatella; Prum, Kannitha; Douard, Véronique; Ferraris, Ronaldo P

    2008-01-01

    Background While searching by microarray for sugar-responsive genes, we inadvertently discovered that sodium-phosphate cotransporter 2B (NaPi-2b) mRNA concentrations were much lower in fructose-perfused than in glucose-perfused intestines of neonatal rats. Changes in NaPi-2b mRNA abundance by sugars were accompanied by similar changes in NaPi-2b protein abundance and in rates of inorganic phosphate (Pi) uptake. Objective We tested the hypothesis that luminal fructose regulates NaPi-2b. Design We perfused into the intestine fructose, glucose, and non-metabolizable or poorly transported glucose analogs as well as phlorizin. Results NaPi-2b mRNA concentrations and Pi uptake rates in fructose-perfused intestines were ≈30% of those in glucose and its analogs. NaPi-2b inhibition by fructose is specific because the mRNA abundance and activity of the fructose transporter GLUT5 (glucose transporter 5) increased with fructose perfusion, whereas those of other transporters were independent of the perfusate. Plasma Pi after 4 h of perfusion was independent of the perfusate, probably because normal kidneys can maintain normophosphatemia. Inhibiting glucose-6-phosphatase, another fructose-responsive gene, with tungstate or vanadate nonspecifically inhibited NaPi-2b mRNA expression and Pi uptake in both glucose- or fructose-perfused intestines. The AMP kinase (AMPK)–activator AICAR (5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside) enhanced and the fatty acid synthase–AMPK inhibitor C75 (3-carboxy-4-octyl-2-methylene-butyrolactone trans-4-carboxy-5-octyl-3-methylenebutyrolactone) prevented fructose inhibition of NaPi-2b but had no effect on expression of other transporters. NaPi-2b expression decreased markedly with age and was inhibited by fructose in all age groups. Conclusions Energy levels in enterocytes may play a role in NaPi-2b inhibition by luminal fructose. Consumption of fructose that supplies ≈10% of caloric intake by Americans clearly affects absorption of

  12. Magnesium substitution in the structure of orthopedic nanoparticles: A comparison between amorphous magnesium phosphates, calcium magnesium phosphates, and hydroxyapatites.

    Science.gov (United States)

    Nabiyouni, Maryam; Ren, Yufu; Bhaduri, Sarit B

    2015-01-01

    As biocompatible materials, magnesium phosphates have received a lot of attention for orthopedic applications. During the last decade multiple studies have shown advantages for magnesium phosphate such as lack of cytotoxicity, biocompatibility, strong mechanical properties, and high biodegradability. The present study investigates the role of Mg(+2) and Ca(+2) ions in the structure of magnesium phosphate and calcium phosphate nanoparticles. To directly compare the effect of Mg(+2) and Ca(+2) ions on structure of nanoparticles and their biological behavior, three groups of nanoparticles including amorphous magnesium phosphates (AMPs) which release Mg(+2), calcium magnesium phosphates (CMPs) which release Mg(+2) and Ca(+2), and hydroxyapatites (HAs) which release Ca(+2) were studied. SEM, TEM, XRD, and FTIR were used to evaluate the morphology, crystallinity, and chemical properties of the particles. AMP particles were homogeneous nanospheres, whereas CMPs were combinations of heterogeneous nanorods and nanospheres, and HAs which contained heterogeneous nanosphere particles. Cell compatibility was monitored in all groups to determine the cytotoxicity effect of particles on studied MC3T3-E1 preosteoblasts. AMPs showed significantly higher attachment rate than the HAs after 1 day and both AMPs and CMPs showed significantly higher proliferation rate when compared to HAs after 7days. Gene expression level of osteoblastic markers ALP, COL I, OCN, OPN, RUNX2 were monitored and they were normalized to GAPDH housekeeping gene. Beta actin expression level was monitored as the second housekeeping gene to confirm the accuracy of results. In general, AMPs and CMPs showed higher expression level of osteoblastic genes after 7 days which can further confirm the stimulating role of Mg(+2) and Ca(+2) ions in increasing the proliferation rate, differentiation, and mineralization of MC3T3-E1 preosteoblasts.

  13. Synthesis and characterization of uranium (IV) phosphate-hydrogenphosphate hydrate and cerium (IV) phosphate-hydrogenphosphate hydrate

    Science.gov (United States)

    Brandel, V.; Clavier, N.; Dacheux, N.

    2005-04-01

    A new uranium (IV) phosphate of proposed formula U 2(PO 4) 2HPO 4·H 2O, i.e. uranium phosphate-hydrogenphosphate hydrate (UPHPH), was synthesized in autoclave and/or in polytetrafluoroethylene closed containers at 150 °C by three ways: from uranium (IV) hydrochloric solution and phosphoric acid, from uranium dioxide and phosphoric acid and by transformation of the uranium hydrogenphosphate hydrate U(HPO 4) 2· nH 2O. The new product appears similar to the previously published thorium phosphate-hydrogenphosphate hydrate Th 2(PO 4) 2HPO 4·H 2O (TPHPH). From preliminary studies, it was found that UPHPH crystallizes in monoclinic system ( a=2.1148(7) nm, b=0.6611(2) nm, c=0.6990(3) nm, β=91.67(3)° and V=0.9768(10) nm). Heated under inert atmosphere, this compound is decomposed above 400 °C into uranium phosphate-triphosphate U 2(PO 4)P 3O 10, uranium diphosphate α-UP 2O 7 and diuranium oxide phosphate U 2O(PO 4) 2. Crystallized cerium (IV) phosphate-hydrogenphosphate hydrate Ce 2(PO 4) 2HPO 4·H 2O (CePHPH) was also synthesized from (NH 4) 2Ce(NO 3) 6 and phosphoric acid solutions by the same method (monoclinic system: a=2.1045(5) nm, b=0.6561(2) nm, c=0.6949(2) nm, β=91.98(1)° and V=0.9588(9) nm). When heating above 600 °C, cerium (IV) is reduced into Ce (III) and forms a mixture of CePO 4 (monazite structure) and CeP 3O 9.

  14. Study on phosphating treatment of aluminum alloy: role of yttrium oxide

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shenglin

    2009-01-01

    Zinc phosphate coatings formed on 6061-Al alloy, after dipping in phosphating solutions containing different amounts of Y2O3(yttrium oxide), were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and electrochemical measurements. Significant variations in the morphology and corrosion resistance afforded by zinc phosphate coating were especially observed as Y2O3 in phosphating solution varied from 0 to 40 mg/L. The addition of Y2O3 changed the initial potential of the interface between aluminum alloy substrate and phosphating solution and increased the number of nucleation sites. The phosphate coating thereby was less porous structure and covered the surface of aluminum alloy completely within short phosphating time. Phosphate coating was mainly composed of Zn3(PO4)2-4H2O (hopeite) and AIPO4(aluminum phosphate). Y2O3, as an additive of phosphatization, accelerated precipitation and refined the gain size of phosphate coating. The corrosion resistance of zinc phosphate coating in 3% NaCl solution was improved as shown by po-larization measurement. In the present research, the optimal amount of Y2O3 was 10-20 mg/L, and the optimal phosphating time was 600 s.

  15. Gastrointestinal phosphate handling in CKD and its association with cardiovascular disease.

    Science.gov (United States)

    Weinman, Edward J; Light, Paul D; Suki, Wadi N

    2013-11-01

    Increases in serum concentrations of parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF-23) and ultimately phosphate and decreases in 1,25-dihydroxyvitamin D level are thought to play a central role in the progressive nature of kidney disease and the development of cardiovascular disease in patients with chronic kidney disease. The initial changes in PTH and FGF-23 levels are adaptive to maintain serum phosphate concentration and phosphate load within defined levels by increasing urinary excretion of phosphate. Less well appreciated is the unanticipated finding that absorption of phosphate from the gastrointestinal tract is not downregulated in chronic kidney disease. This maladaptive response maintains higher levels of phosphate absorption, thereby contributing to the phosphate burden. Moreover, in response to a low-phosphate diet, as often is prescribed to such patients, gut phosphate absorption may be enhanced, undermining the potential beneficial effects of this intervention. Given the poor response to limiting phosphate intake and the use of phosphate binders, we suggest that research efforts be oriented toward better understanding of the factors that affect phosphate absorption in the gastrointestinal tract and the development of agents that directly inhibit phosphate transporters in the small intestine and/or their associated binding proteins.

  16. Cirrhosis Associated with Pyridoxal 5′-Phosphate Treatment of Pyridoxamine 5′-Phosphate Oxidase Deficiency

    OpenAIRE

    2014-01-01

    We report the case of an 8-year-old boy with pyridoxamine 5′-phosphate oxidase (PNPO) deficiency. He developed seizures at 24 h of age that were refractory to standard anticonvulsant therapy and a trial of pyridoxine but responded to pyridoxal phosphate (PLP) at 28 days of life. Genetic testing identified compound heterozygous mutations in the PNPO gene. Management of encephalopathic episodes required escalation of PLP dose to 100 mg/kg/day by 2 years of age. Routine blood tests at this time ...

  17. 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...... by solubilization temperature. An antiserum against Psi1 recognized a protein of M,55,000 in four other P. fluorescens strains among 24 tested strains representing Pseudomonas rRNA homology group I, showing antigenicheterogeneity within this group. A method for immunofluorescence microscopy involving cell...

  18. Distrontium trimanganese(II) bis-(hydro-gen-phosphate) bis-(ortho-phosphate).

    Science.gov (United States)

    Khmiyas, Jamal; Assani, Abderrazzak; Saadi, Mohamed; El Ammari, Lahcen

    2013-01-01

    The title compound, Sr2Mn3(HPO4)2(PO4)2, was synthesized under hydro-thermal conditions. In the structure, one of two Mn atoms is located on an inversion centre, whereas all others atoms are located in general positions. The framework structure is built up from two types of MnO6 octa-hedra (one almost undistorted, one considerably distorted), one PO3OH and one PO4 tetra-hedron. The centrosymmetric MnO6 octa-hedron is linked to two other MnO6 octa-hedra by edge-sharing, forming infinite zigzag chains parallel to [010]. The PO3OH and PO4 tetra-hedra connect these chains through common vertices or edges, resulting in the formation of sheets parallel to (100). The Sr(2+) cation is located in the inter-layer space and is bonded to nine O atoms in form of a distorted polyhedron and enhances the cohesion of the layers. Additional stabilization is achieved by a strong inter-layer O-H⋯O hydrogen bond between the PO3OH and PO4 units. The structure of the title phosphate is isotypic to that of Pb2Mn3(HPO4)2(PO4)2.

  19. Crystal structure of hydrazine iron(III) phosphate, the first transition metal phosphate containing hydrazine.

    Science.gov (United States)

    David, Renald

    2015-12-01

    The title compound, poly[(μ2-hydrazine)(μ4-phosphato)iron(III)], [Fe(PO4)(N2H4)] n , was prepared under hydro-thermal conditions. Its asymmetric unit contains one Fe(III) atom located on an inversion centre, one P atom located on a twofold rotation axis, and two O, one N and two H atoms located on general positions. The Fe(III) atom is bound to four O atoms of symmetry-related PO4 tetra-hedra and to two N atoms of two symmetry-related hydrazine ligands, resulting in a slightly distorted FeO4N2 octa-hedron. The crystal structure consists of a three-dimensional hydrazine/iron phoshate framework whereby each PO4 tetra-hedron bridges four Fe(III) atoms and each hydrazine ligand bridges two Fe(III) atoms. The H atoms of the hydrazine ligands are also involved in moderate N-H⋯O hydrogen bonding with phosphate O atoms. The crystal structure is isotypic with the sulfates [Co(SO4)(N2H4)] and [Mn(SO4)(N2H4)].

  20. Enhanced flux through the methylerythritol 4-phosphate pathway in Arabidopsis plants overexpressing deoxyxylulose 5-phosphate reductoisomerase.

    Science.gov (United States)

    Carretero-Paulet, Lorenzo; Cairó, Albert; Botella-Pavía, Patricia; Besumbes, Oscar; Campos, Narciso; Boronat, Albert; Rodríguez-Concepción, Manuel

    2006-11-01

    The methylerythritol 4-phosphate (MEP) pathway synthesizes the precursors for an astonishing diversity of plastid isoprenoids, including the major photosynthetic pigments chlorophylls and carotenoids. Since the identification of the first two enzymes of the pathway, deoxyxylulose 5-phoshate (DXP) synthase (DXS) and DXP reductoisomerase (DXR), they both were proposed as potential control points. Increased DXS activity has been shown to up-regulate the production of plastid isoprenoids in all systems tested, but the relative contribution of DXR to the supply of isoprenoid precursors is less clear. In this work, we have generated transgenic Arabidopsis thaliana plants with altered DXS and DXR enzyme levels, as estimated from their resistance to clomazone and fosmidomycin, respectively. The down-regulation of DXR resulted in variegation, reduced pigmentation and defects in chloroplast development, whereas DXR-overexpressing lines showed an increased accumulation of MEP- derived plastid isoprenoids such as chlorophylls, carotenoids, and taxadiene in transgenic plants engineered to produce this non-native isoprenoid. Changes in DXR levels in transgenic plants did not result in changes in DXS gene expression or enzyme accumulation, confirming that the observed effects on plastid isoprenoid levels in DXR-overexpressing lines were not an indirect consequence of altering DXS levels. The results indicate that the biosynthesis of MEP (the first committed intermediate of the pathway) limits the production of downstream isoprenoids in Arabidopsis chloroplasts, supporting a role for DXR in the control of the metabolic flux through the MEP pathway.

  1. Crystal structure of hydrazine iron(III phosphate, the first transition metal phosphate containing hydrazine

    Directory of Open Access Journals (Sweden)

    Renald David

    2015-12-01

    Full Text Available The title compound, poly[(μ2-hydrazine(μ4-phosphatoiron(III], [Fe(PO4(N2H4]n, was prepared under hydrothermal conditions. Its asymmetric unit contains one FeIII atom located on an inversion centre, one P atom located on a twofold rotation axis, and two O, one N and two H atoms located on general positions. The FeIII atom is bound to four O atoms of symmetry-related PO4 tetrahedra and to two N atoms of two symmetry-related hydrazine ligands, resulting in a slightly distorted FeO4N2 octahedron. The crystal structure consists of a three-dimensional hydrazine/iron phoshate framework whereby each PO4 tetrahedron bridges four FeIII atoms and each hydrazine ligand bridges two FeIII atoms. The H atoms of the hydrazine ligands are also involved in moderate N—H...O hydrogen bonding with phosphate O atoms. The crystal structure is isotypic with the sulfates [Co(SO4(N2H4] and [Mn(SO4(N2H4].

  2. Surface modification of layered zirconium phosphate with PNIPAM.

    Science.gov (United States)

    Wang, Xuezhen; Zhao, Di; Medina, Ilse B Nava; Diaz, Agustin; Wang, Huiliang; Clearfield, Abraham; Mannan, M Sam; Cheng, Zhengdong

    2016-04-04

    A new method was reported to modify layered zirconium phosphate (ZrP) with thermoresponsive polymer PNIPAM (poly N-isopropylacrylamide). PNIPAM was proved to be covalently grafted onto ZrP. (60)Co γ-rays irradiation produced peroxide groups on the surface which, upon heating, initiated free radical polymerization and subsequent attachment of PNIPAM.

  3. Calcium phosphate bioceramics prepared from wet chemically precipitated powders

    Directory of Open Access Journals (Sweden)

    Kristine Salma

    2010-03-01

    Full Text Available In this work calcium phosphates were synthesized by modified wet chemical precipitation route. Contrary to the conventional chemical precipitation route calcium hydroxide was homogenized with planetary mill. Milling calcium oxide and water in planetary ball mill as a first step of synthesis provides a highly dispersed calcium hydroxide suspension. The aim of this work was to study the influence of main processing parameters of wet chemical precipitation synthesis product and to control the morphology, phase and functional group composition and, consequently, thermal stability and microstructure of calcium phosphate bioceramics after thermal treatment. The results showed that it is possible to obtain calcium phosphates with different and reproducible phase compositions after thermal processing (hydroxyapatite [HAp], β-tricalcium phosphate [β-TCP] and HAp/β-TCP by modified wet-chemical precipitation route. The β-TCP phase content in sintered bioceramics samples is found to be highly dependent on the changes in technological parameters and it can be controlled with ending pH, synthesis temperature and thermal treatment. Pure, crystalline and highly thermally stable (up to 1300°C HAp bioceramics with homogenous grainy microstructure, grain size up to 200–250 nm and high open porosity can be successfully obtained by powder synthesized at elevated synthesis temperature of 70°C and stabilizing ending pH at 9.

  4. 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 ... further applied to determine the ALP content in healthy human serum and the results were in ... substrates to produce phenol or p-aminophenol, which is electroactive and can be ... bovine serum, human serum and untreated human blood with the linear ...

  5. Red Algal Bromophenols as Glucose 6-Phosphate Dehydrogenase Inhibitors

    Directory of Open Access Journals (Sweden)

    Koretaro Takahashi

    2013-10-01

    Full Text Available Five bromophenols isolated from three Rhodomelaceae algae (Laurencia nipponica, Polysiphonia morrowii, Odonthalia corymbifera showed inhibitory effects against glucose 6-phosphate dehydrogenase (G6PD. Among them, the symmetric bromophenol dimer (5 showed the highest inhibitory activity against G6PD.

  6. Pathogenic role of basic calcium phosphate crystals in destructive arthropathies

    NARCIS (Netherlands)

    Ea, H.K.; Chobaz, V.; Nguyen, C.; Nasi, S.; Lent, P.L. van; Daudon, M.; Dessombz, A.; Bazin, D.; McCarthy, G.; Jolles-Haeberli, B.; Ives, A.; Linthoudt, D. Van; So, A.; Liote, F.; Busso, N.

    2013-01-01

    BACKGROUND: basic calcium phosphate (BCP) crystals are commonly found in osteoarthritis (OA) and are associated with cartilage destruction. BCP crystals induce in vitro catabolic responses with the production of metalloproteases and inflammatory cytokines such as interleukin-1 (IL-1). In vivo, IL-1

  7. Polyfluorinated alkyl phosphate ester surfactants - current knowledge and knowledge gaps

    DEFF Research Database (Denmark)

    Taxvig, Camilla; Rosenmai, Anna Kjerstine; Vinggaard, Anne Marie

    2014-01-01

    information on fluorochemicals. Polyfluorinated alkyl phosphate ester surfactants (PAPs) belong to the group of polyfluorinated alkyl surfactants. They have been detected in indoor dust and are widely used in food-contact materials, from which they have the ability to migrate into food. Toxicological data...

  8. Flocculation of Kaolin by Waxy Maize Starch Phosphates

    Science.gov (United States)

    Waxy maize starch phosphates were tested as flocculants in order to determine if they have the potential to replace petroleum-based polymer flocculants currently used commercially. Phosphorylation was carried out by dry heating of starches and sodium orthophosphates at 140 degrees C for 4 hours. N...

  9. Iron-catalysed Negishi coupling of benzyl halides and phosphates.

    Science.gov (United States)

    Bedford, Robin B; Huwe, Michael; Wilkinson, Mark C

    2009-02-01

    Iron-based catalysts containing either 1,2-bis(diphenylphosphino)benzene or 1,3-bis(diphenylphosphino)propane give excellent activity and good selectivity in the Negishi coupling of aryl zinc reagents with a range of benzyl halides and phosphates.

  10. Immobilization of fission products in phosphate ceramic waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Singh, D. [Argonne National Lab., IL (United States)

    1996-10-01

    The goal of this project is to develop and demonstrate the feasibility of a novel low-temperature solidification/stabilization (S/S) technology for immobilizing waste streams containing fission products such as cesium, strontium, and technetium in a chemically bonded phosphate ceramic. This technology can immobilize partitioned tank wastes and decontaminate waste streams containing volatile fission products.

  11. Injectable calcium phosphate cement for bone repair and implant fixation.

    NARCIS (Netherlands)

    Jansen, J.; Ooms, E.M.; Verdonschot, N.J.J.; Wolke, J.G.C.

    2005-01-01

    The studies as described are aimed at determining the efficacy of newly developed calcium phosphate cement when this material is used as a bone defect filler or gap filler around metal implants. An overview is provided about bone graft substitutes and methods of metal implant fixation.

  12. Hydrogen Bonding in Phosphine Oxide/Phosphate-Phenol Complexes

    NARCIS (Netherlands)

    Cuypers, R.; Sudhölter, E.J.R.; Zuilhof, H.

    2010-01-01

    To develop a new solvent-impregnated resin (SIR) system for the removal of phenols and thiophenols from water, complex formation by hydrogen bonding of phosphine oxides and phosphates is studied using isothermal titration calorimetry (ITC) and quantum chemical modeling. Six different computational m

  13. Phosphates nanoparticles doped with zinc and manganese for sunscreens

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, T.S. de, E-mail: tatiana.araujo@ifs.edu.br [Departamento de Fisica, Universidade Federal de Sergipe, Sergipe (Brazil); Instituto Federal de Ciencias e Tecnologia de Sergipe, Sergipe (Brazil); Souza, S.O. de [Departamento de Fisica, Universidade Federal de Sergipe, Sergipe (Brazil); Miyakawa, W. [Divisao de Fotonica - Instituto de Estudos Avancados, Sao Jose dos Campos (Brazil); Sousa, E.M.B. de [Centro de Desenvolvimento de Tecnologia Nuclear - CDTN/CNEN, Minas Gerais (Brazil)

    2010-12-01

    The crescent number of skin cancer worldwide gives impulse to the development of sunscreen that can both prevent skin cancer and also permit gradual tanning. In this work, the synthesis of hydroxyapatite and tricalcium phosphate nanocrystalline powders was investigated in order to obtain materials with optical properties and appropriate size for sunscreen. Pure, Zn{sup 2+}-doped and Mn{sup 2+}-doped hydroxyapatite (HAP) and tricalcium phosphate ({beta}-TCP) were produced by the wet precipitation process using diammonium phosphate, calcium nitrate, ammonium hydroxide, zinc nitrate and manganese nitrate as reagents. The pure and doped HAP precipitates were calcined at 500 deg. C for 1 h, while the {beta}-TCP (pure and doped) were calcined at 800 deg. C for 2 h. The powder samples were characterized by X-ray diffraction (XRD), energy dispersive X-ray fluorescence (EDX), atomic force microscopy (AFM) and ultraviolet (UV)-vis spectroscopy. XRD and EDX showed the formation of the expected materials (HAP and {beta}-TCP) without toxic components. AFM micrographs showed aggregated ellipsoidal particles with dimensions smaller than 120 nm. Optical absorption spectra showed that the calcium phosphate produced in this work absorbs in the UV region. The obtained materials presented structural, morphological and optical properties that allow their use as the active centers in sunscreens.

  14. Calcium phosphate implants coatings as carriers for BMP-2

    NARCIS (Netherlands)

    Liu, Y.; He, J.F.; Hunziker, E.B.

    2009-01-01

    The osteoconductivity of dental implants can be improved by coating them with a layer of calcium phosphate (CaP), which can be rendered osteoinductive by functionalizing it with an osteogenic agent, such as bone morphogenetic protein 2 (BMP-2). In the present study, we wished to compare the osteoind

  15. Cellular response of Campylobacter jejuni to trisodium phosphate

    DEFF Research Database (Denmark)

    Riedel, Charlotte Tandrup; Cohn, M. T.; Stabler, R. A.

    2012-01-01

    The highly alkaline compound trisodium phosphate (TSP) is used as an intervention to reduce the load of Campylobacter on poultry meat in U.S. poultry slaughter plants. The aim of the present study was to investigate the cellular responses of Campylobacter jejuni NCTC11168 when exposed to sublethal...

  16. Role of phosphate and carboxylate ions in maillard browning.

    Science.gov (United States)

    Rizzi, George P

    2004-02-25

    The Maillard reaction of carbohydrates and amino acids is the underlying chemical basis for flavor and color formation in many processed foods. Phosphate and other polyatomic anions will accelerate the rate of Maillard browning, and this effect has been explained by invoking enhanced proton abstraction from intermediate Amadori compounds. In this work, the effect of phosphate and carboxylate ions on browning was measured for a series of reducing sugars with and without the presence of beta-alanine. Significant browning was observed for sugars alone suggesting that polyatomic anions contribute to Maillard browning by providing reactive intermediates directly from sugars. A mechanism is proposed for decomposition of sugars by polyatomic anions and efforts to trap reactive species using o-phenylenediamine (OPD) are described. The results of this study suggest how complications may arise from the popular usage of phosphate buffers in the study of Maillard reaction kinetics. In addition, the results imply how phosphates may be useful for enhancing browning during food processing.

  17. Oxygen isotope fractionation between human phosphate and water revisited

    DEFF Research Database (Denmark)

    Daux, Valérie; Lécuyer, Christophe; Héran, Marie-Anne;

    2008-01-01

    The oxygen isotope composition of human phosphatic tissues (delta18OP) has great potential for reconstructing climate and population migration, but this technique has not been applied to early human evolution. To facilitate this application we analyzed delta18OP values of modern human teeth...

  18. Synthesis, characterization and photocatalytic reactions of phosphated mesoporous titania

    Indian Academy of Sciences (India)

    Pallabi Goswami; Jatindra Nath Ganguli

    2012-10-01

    Mesoporous titania nanoparticles with a well-definedmesostructure was prepared by hydrothermal process, using nonionic triblock copolymer P123 as surfactant template, modified with phosphoric acid and followed by calcination at 600°C. The sol–gel titania was modified by in situ phosphorylation using phosphoric acid and thereby incorporating phosphorous directly into the framework of TiO2. The resulting materials were characterized by XRD, SEM, TEM, nitrogen adsorption, TGA and DRS. It was found that the structural and optical properties of titania samples are strongly influenced by their phosphate modification. In case of calcined samples a positive effect on the specific surface area for the in situ phosphated sample was found. Mesoporous structure of phosphated titania did not collapse even after calcination at 600°C. The enhanced photocatalytic activity of the synthesized phosphate nanomaterials were evaluated through a study of the decomposition of fluorescein under UV light excitation and compared with undoped titania nanomaterial as well as with commercial titania.

  19. Homolytic C-O cleavage in phosphates and sulfonates.

    Science.gov (United States)

    Ding, Lanlan; Zheng, Wenrui; Wang, Yingxing

    2015-04-09

    The C-O homolytic bond dissociation enthalpies(BDEs) were calculated by high-level ab initio including G4, G3B3, G3, CBS-QB3 and a series of density function theory (DFT) methods. It is found that the wB97 method gave the most reliable C-O BDEs and the root-mean-square deviation (RMSD) is 7.6 kJ/mol. Therefore, the C(sp(2))-O BDE predictions and the substituent effects of alkenyl phosphates/sulfonates and aryl phosphates/sulfonates were investigated in detail by using the wB97 method. Interestingly, there exist different substituent effects in α- and β-substituted alkenyl phosphates/sulfonates. Excellent linear relationships between the C-O BDEs of β-substituted alkenyl phosphates/sulfonates with substituent constant σp(+) were found. In addition, the NBO analysis further disclosed the essence of the substituent effects on C-O BDEs.

  20. A Selective and Mild Synthetic Route to Dialkyl Phosphates

    NARCIS (Netherlands)

    Kuiper, Johanna M.; Hulst, Ron; Engberts, Jan B.F.N.

    2003-01-01

    A very mild synthetic route to dialkyl phosphates is described. Reaction of the appropriate alcohol with PCl3 followed by treatment with pyridine and CCl4 afforded the corresponding trichloromethyl ester. Subsequent reaction with the triethylamine salt of acetic acid followed by hydrolysis of the fo

  1. An off-the-shelf sensing system for physiological phosphates.

    Science.gov (United States)

    Mallet, Alie M; Liu, Yuanli; Bonizzoni, Marco

    2014-05-21

    An off-the-shelf supramolecular sensing system was designed to discriminate biologically relevant phosphates in neutral water using multivariate data analysis. The system is based on an indicator displacement assay comprising only two unmodified commercially available components: a dendritic poly-electrolyte and a common fluorescent dye. Effective discrimination of nucleotide diphosphates and inorganic diphosphate was achieved through principal component analysis (PCA).

  2. Modelling aqueous corrosion of nuclear waste phosphate glass

    Science.gov (United States)

    Poluektov, Pavel P.; Schmidt, Olga V.; Kascheev, Vladimir A.; Ojovan, Michael I.

    2017-02-01

    A model is presented on nuclear sodium alumina phosphate (NAP) glass aqueous corrosion accounting for dissolution of radioactive glass and formation of corrosion products surface layer on the glass contacting ground water of a disposal environment. Modelling is used to process available experimental data demonstrating the generic inhibiting role of corrosion products on the NAP glass surface.

  3. Ionothermal synthesis and crystal structures of metal phosphate chains

    NARCIS (Netherlands)

    Wragg, D.; Le Ouay, B.; Beale, A.M.; O'Brien, M.G.; Slawin, A.M.Z.; Warren, J.E.; Prior, T.J.; Morris, R.E.

    2013-01-01

    We have prepared isostructural aluminium and gallium phosphate chains by ionothermal reactions in 1-ethyl-3-methylimidazolium bromide and 1-ethylpyridinium bromide under a variety of conditions. The chains can be prepared as pure phases or along with three dimensional framework phases. The chains ar

  4. Calcium phosphate nucleation on surface-modified PTFE membranes.

    Science.gov (United States)

    Grøndahl, Lisbeth; Cardona, Francisco; Chiem, Khang; Wentrup-Byrne, Edeline; Bostrom, Thor

    2003-06-01

    Highly porous PTFE membranes are currently being used in facial reconstructive surgery. The present study aims at improving this biomaterial through creating a more bioactive surface by introducing ionic groups onto the surface. The unmodified PTFE membrane does not induce inorganic growth after immersion in simulated body fluid (SBF) for up to 4 weeks. Copolymeric grafting with acrylic acid (AAc) by means of gamma irradiation and subsequent in vitro testing in SBF reveals that this copolymer initially acts as an ion-exchange material and subsequently induces growth of a calcium phosphate phase (Ca/P=2.7) when large amounts (15%) of pAAc are introduced onto the membrane surface. This copolymer is not expected to function well from a biomaterials perspective since SEM showed the pores on the surface to be partly blocked. In contrast, the surface of monoacryloxyethyl phosphate (MAEP)-modified samples is altered at a molecular level only. Yet the modified materials are able to induce calcium phosphate nucleation when the external surface coverage is 44% or above. The initial inorganic growth on these membranes in SBF has a (Ca+Mg)/P ratio of 1.1 (presumably Brushite or Monetite). The secondary growth, possibly calcium-deficient apatite or tricalcium phosphate, has a (Ca+Mg)/P ratio of 1.5. This result is a promising indicator of a bioactive biomaterial.

  5. Factors influencing calcium phosphate cement shelf-life.

    Science.gov (United States)

    Gbureck, Uwe; Dembski, Sofia; Thull, Roger; Barralet, Jake E

    2005-06-01

    Long-term stability during storage (shelf-life) is one major criterion for the use of a material as medical device. This study aimed to investigate the ageing process of beta-tricalcium phosphate/monocalcium phosphate cement powders when stored in sealed containers at ambient conditions. This kind of cement type is of interest because it is forming dicalcium phosphate dihydrate (brushite) when set, which is in contrast to hydroxyapatite resorbable in physiological conditions. The stability of cements was checked by either measuring the phase composition of powders as well as the setting time and compressive strength when mixed with sodium citrate as liquid. Critical factors influencing ageing were found to be temperature, humidity and the mixing regime of the powders. Mechanically mixed cement powders which were stored in normal laboratory atmosphere (22 degrees C, 60% rel. humidity) converted to dicalcium phosphate anhydrous (monetite) within a few days; this could be mechanistically related to a dissolution/precipitation process since humidity condensed on the particles' surfaces and acted as reaction medium. Various storage conditions were found to be effective in prolonging cement stability which were in order of effectiveness: adding solid citric acid retardant>dry argon atmosphere=gentle mixing (minimal mechanical energy input) low temperature.

  6. Osteoinduction of calcium phosphate biomaterials in small animals

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Lijia; Shi, Yujun [Key Laboratory of Transplant Engineering and Immunology, Ministry of Health, West China Hospital, Sichuan University, Chengdu (China); Ye, Feng [Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041 (China); Bu, Hong, E-mail: hongbu@scu.edu.cn [Key Laboratory of Transplant Engineering and Immunology, Ministry of Health, West China Hospital, Sichuan University, Chengdu (China); Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041 (China)

    2013-04-01

    Although osteoinduction mechanism of calcium phosphate (CP) ceramics is still unclear, several essential properties have been reported, such as chemical composition, pore size and porosity, etc. In this study, calcium phosphate powder (Ca{sub 3}(PO{sub 4}){sub 2}, CaP, group 1), biphasic calcium phosphate ceramic powder (BCP, group 2), and intact BCP rods (group 3) were implanted into leg muscles of mice and dorsal muscles of rabbits. One month and three months after implantation, samples were harvested for biological and histological analysis. New bone tissues were observed in 10/10 samples in group 1, 3/10 samples in group 2, and 9/10 samples in group 3 at 3rd month in mice, but not in rabbits. In vitro, human mesenchymal stem cells (hMSCs) were cultured with trace CaP and BCP powder, and osteogenic differentiation was observed at day 7. Our results suggested that chemical composition is the prerequisite in osteoinduction, and pore structure would contribute to more bone formation. - Highlights: ► Intrinsic osteoinduction of calcium phosphate biomaterials was observed implanted in muscles of mice. ► Biomaterials powder also has osteoinduction property. ► Osteogenic genes and protein could be detected by RT-PCR and Western blot in implanted biomaterials. ► Osteogenic phenomenon could be observed by electron microscopy. ► The chemical composition is the prerequisite in osteoinduction, and pore structure would contribute to more bone formation.

  7. In vivo bone response to porous calcium phosphate cement.

    NARCIS (Netherlands)

    Real, R.P. del; Ooms, E.M.; Wolke, J.G.C.; Vallet-Regi, M.; Jansen, J.A.

    2003-01-01

    We conducted an in vivo experiment to evaluate the resorption rate of a calcium phosphate cement (CPC) with macropores larger than 100 microm, using the CPC called Biocement D (Merck Biomaterial, Darmstadt, Germany), which after setting only shows pores smaller than 1 microm. The gas bubble method u

  8. Recent revisions of phosphate rock reserves and resources: a critique

    NARCIS (Netherlands)

    Edixhoven, J.D.; Gupta, J.; Savenije, H.H.G.

    2014-01-01

    Phosphate rock (PR) is a finite mineral indispensable for fertilizer production, while P (phosphorus) is a major pollutant if applied or discharged in excess, causing widespread eutrophication (Carpenter and Bennet, 2011). High-grade PR is obtained from deposits which took millions of years to form

  9. Mechanical properties of porous, electrosprayed calcium phosphate coatings

    NARCIS (Netherlands)

    Leeuwenburgh, S.C.G.; Wolke, J.G.C.; Lommen, L.; Pooters, T.; Schoonman, J.; Jansen, J.A.

    2006-01-01

    Mechanical properties of calcium phosphate coatings (CaP), deposited using the electrostatic spray deposition (ESD) technique, have been characterized using a range of analytical techniques, including tensile testing (ASTM C633), fatigue testing (ASTM E855), and scratch testing using blunt and sharp

  10. Transmission spectra study of sulfate substituted potassium dihydrogen phosphate

    KAUST Repository

    LI, LIANG

    2013-04-18

    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 in the ultraviolet region which confirms and agrees well with former results. © 2013 Astro Ltd.

  11. Ribose 5-Phosphate Isomerase Investigations for the Undergraduate Biochemistry Laboratory

    Science.gov (United States)

    Jewett, Kathy; Sandwick, Roger K.

    2011-01-01

    The enzyme ribose 5-phosphate isomerase (RpiA) has many features that make it attractive as a focal point of a semester-long, advanced biochemistry laboratory for undergraduate students. The protein can easily and inexpensively be isolated from spinach using traditional purification techniques. Characterization of RpiA enzyme activity can be…

  12. Novel inhibitors of mitochondrial sn-glycerol 3-phosphate dehydrogenase.

    Directory of Open Access Journals (Sweden)

    Adam L Orr

    Full Text Available Mitochondrial sn-glycerol 3-phosphate dehydrogenase (mGPDH is a ubiquinone-linked enzyme in the mitochondrial inner membrane best characterized as part of the glycerol phosphate shuttle that transfers reducing equivalents from cytosolic NADH into the mitochondrial electron transport chain. Despite the widespread expression of mGPDH and the availability of mGPDH-null mice, the physiological role of this enzyme remains poorly defined in many tissues, likely because of compensatory pathways for cytosolic regeneration of NAD⁺ and mechanisms for glycerol phosphate metabolism. Here we describe a novel class of cell-permeant small-molecule inhibitors of mGPDH (iGP discovered through small-molecule screening. Structure-activity analysis identified a core benzimidazole-phenyl-succinamide structure as being essential to inhibition of mGPDH while modifications to the benzimidazole ring system modulated both potency and off-target effects. Live-cell imaging provided evidence that iGPs penetrate cellular membranes. Two compounds (iGP-1 and iGP-5 were characterized further to determine potency and selectivity and found to be mixed inhibitors with IC₅₀ and K(i values between ∼1-15 µM. These novel mGPDH inhibitors are unique tools to investigate the role of glycerol 3-phosphate metabolism in both isolated and intact systems.

  13. Novel Inhibitors of Mitochondrial sn-Glycerol 3-phosphate Dehydrogenase

    Science.gov (United States)

    Orr, Adam L.; Ashok, Deepthi; Sarantos, Melissa R.; Ng, Ryan; Shi, Tong; Gerencser, Akos A.; Hughes, Robert E.; Brand, Martin D.

    2014-01-01

    Mitochondrial sn-glycerol 3-phosphate dehydrogenase (mGPDH) is a ubiquinone-linked enzyme in the mitochondrial inner membrane best characterized as part of the glycerol phosphate shuttle that transfers reducing equivalents from cytosolic NADH into the mitochondrial electron transport chain. Despite the widespread expression of mGPDH and the availability of mGPDH-null mice, the physiological role of this enzyme remains poorly defined in many tissues, likely because of compensatory pathways for cytosolic regeneration of NAD+ and mechanisms for glycerol phosphate metabolism. Here we describe a novel class of cell-permeant small-molecule inhibitors of mGPDH (iGP) discovered through small-molecule screening. Structure-activity analysis identified a core benzimidazole-phenyl-succinamide structure as being essential to inhibition of mGPDH while modifications to the benzimidazole ring system modulated both potency and off-target effects. Live-cell imaging provided evidence that iGPs penetrate cellular membranes. Two compounds (iGP-1 and iGP-5) were characterized further to determine potency and selectivity and found to be mixed inhibitors with IC50 and Ki values between ∼1–15 µM. These novel mGPDH inhibitors are unique tools to investigate the role of glycerol 3-phosphate metabolism in both isolated and intact systems. PMID:24587137

  14. Research of inhibitor properties of the modified polymeric phosphates

    Directory of Open Access Journals (Sweden)

    A. Rakhova

    2012-03-01

    Full Text Available Diversity of structures and properties of the functional dependence on the composition of polimernofosfatov allows their use as effective inhibitors of corrosion of steel. In this connection, systematic studies of the relationship between structure, composition and effectiveness of the protective phosphate inhibitory action.

  15. Improved Electrocoagulation Reactor for Rapid Removal of Phosphate from Wastewater

    KAUST Repository

    Tian, Yushi

    2016-11-01

    A new three-electrode electrocoagulation reactor was investigated to increase the rate of removal of phosphate from domestic wastewater. Initially, two electrodes (graphite plate and air cathode) were connected with 0.5 V of voltage applied for a short charging time (∼10 s). The direction of the electric field was then reversed, by switching the power supply lead from the anode to the cathode, and connecting the other lead to a sacrificial aluminum mesh anode for removal of phosphate by electrocoagulation. The performance of this process, called a reverse-electric field, air cathode electrocoagulation (REAEC) reactor, was tested using domestic wastewater as a function of charging time and electrocoagulation time. REAEC wastewater treatment removed up to 98% of phosphate in 15 min (inert electrode working time of 10 s, current density of 1 mA/cm2, and 15 min total electrocoagulation time), which was 6% higher than that of the control (no inert electrode). The energy demand varied from 0.05 kWh/m3 for 85% removal in 5 min, to 0.14 kwh/m3 for 98% removal in 15 min. These results indicate that the REAEC can reduce the energy demands and treatment times compared to conventional electrocoagulation processes for phosphate removal from wastewater.

  16. Optimizing conditions for calcium phosphate mediated transient transfection

    Directory of Open Access Journals (Sweden)

    Ling Guo

    2017-03-01

    Conclusions: Calcium phosphate mediated transfection is the most low-cost approach to introduce recombinant DNA into culture cells. However, the utility of this procedure is limited in highly-differentiated cells. Here we describe the specific HBS-buffered saline, PH, glycerol shock, vortex strength, transfection medium, and particle concentrations conditions necessary to optimize this transfection method in highly differentiated cells.

  17. Biomimetic calcium phosphate coatings on recombinant spider silk fibres

    Energy Technology Data Exchange (ETDEWEB)

    Yang Liang; Habibovic, Pamela; Van Blitterswijk, Clemens A [Department of Tissue Regeneration, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Hedhammar, My; Johansson, Jan [Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, the Biomedical Centre, Box 575, 751 23 Uppsala (Sweden); Blom, Tobias; Leifer, Klaus [Department of Engineering Sciences, Uppsala University, Box 534, S-751 21 Uppsala (Sweden)

    2010-08-01

    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, artificial spider silk, with mechanical and structural characteristics similar to those of native spider silk, has been produced from recombinant minispidroins. In the present study, supersaturated simulated body fluid was used to deposit calcium phosphate coatings on recombinant spider silk fibres. The mineralization process was followed in time using scanning electron microscopy equipped with an energy dispersive x-ray (EDX) detector and Raman spectroscope. Focused ion beam technology was used to produce a cross section of a coated fibre, which was further analysed by EDX. Preliminary in vitro experiments using a culture of bone marrow-derived human mesenchymal stem cells (hMSCs) on coated fibres were also performed. This study showed that recombinant spider silk fibres were successfully coated with a homogeneous and thick crystalline calcium phosphate layer. In the course of the mineralization process from modified simulated body fluid, sodium chloride crystals were first deposited on the silk surface, followed by the deposition of a calcium phosphate layer. The coated silk fibres supported the attachment and growth of hMSCs.

  18. Origin of Life and the Phosphate Transfer Catalyst

    Science.gov (United States)

    Piast, Radosław W.; Wieczorek, Rafał M.

    2017-03-01

    In this paper, we revisit several issues relevant to origin-of-life research and propose a Phosphate Transfer Catalyst hypothesis that furthers our understanding of some of the key events in prebiotic chemical evolution. In the Phosphate Transfer Catalyst hypothesis, we assume the existence of hypothetical metallopeptides with phosphate transfer activity that use abundant polyphosphates as both substrates and energy sources. Nonspecific catalysis by this phosphate transfer catalyst would provide a variety of different products such as phosphoryl amino acids, nucleosides, polyphosphate nucleotides, nucleic acids, and aminoacylated nucleic acids. Moreover, being an autocatalytic set and metabolic driver at the same time, it could possibly replicate itself and produce a collective system of two polymerases; a nucleic acid able to catalyze peptide bond formation and a peptide able to polymerize nucleic acids. The genetic code starts at first as a system that reduces the energy barrier by bringing substrates (2'/3' aminoacyl-nucleotides) together, an ancestral form of the catalysis performed by modern ribosomes.

  19. Effect of codeine phosphate, Lomotil, and Isogel on iileostomy function.

    Science.gov (United States)

    Newton, C R

    1978-05-01

    The effect on ileostomy function of codeine phosphate, Lomotil, or Isogel was tested in 20 subjects at home living a normal life, studied over two three-day periods on and off treatment. Codeine phosphate 60 mg three times daily was associated with a reduction in the mean total weight of ileostomy output and the ileostomy outputs of water, sodium, and potassium (p effluent appeared thicker but the output of faecal solids remained unchanged. Mean faecal fat increased on codeine. The transit rate from mouth to stoma was slower in four of the five subjects on codeine and a further two subjects withdrew from the trial with temporary intestinal obstruction while on the drug. Lomotil two tablets three times daily was associated with a small and statistically not quite significant fall in the mean total weight of ileostomy output and the ileostomy output of water. Sodium and potassium outputs in the effluent fell on Lomotil (p effluent looked more viscid on Isogel, the proportion of faecal solids was unchanged. These results suggest that codeine phosphate has a beneficial effect on ileostomy function, reducing the loss of water and electrolytes, while Lomotil has a similar but less effective action in the dosage tested. By contrast, Isogel increases the ileostomy loss of water and electrolytes and will aggravate their depletion in patients with excessive fluid effluents. The increase in faecal fat associated with taking codeine phosphate suggests that it should be stopped before collecting specimens for faecal fat estimations.

  20. Polaron effects in the protonic conductor hydrogen uranyl phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Lupu, D. (Inst. of Isotopic and Molecular Technology, Cluj-Napoca (Romania)); Grecu, R. (Inst. of Chemistry, Cluj-Napoca (Romania)); Biris, A.R. (Inst. of Isotopic and Molecular Technology, Cluj-Napoca (Romania))

    1993-08-01

    The isotope effects on the conductivity of hydrogen uranyl phosphate reveal ionic polaron effects in this solid protonic conductor, in agreement with the small polaron theory. An absorption band is observed at 0.67 eV, which can be correlated with the conduction mechanism consisting in both tunnelling and over-barrier hopping processes. (orig.)

  1. Does dental zinc phosphate cement really shrink in clinical applications?

    Science.gov (United States)

    Liu, Yang; Yu, Hai-Yang

    2009-08-01

    Crowns are cemented onto abutments with adhesives; and zinc phosphate cement is a routine permanent luting agent, which is believed to secure crowns to abutments by non-adhesive micro-mechanical interlocking. Because it has been proven, and the public widely accepts, that zinc phosphate cement forms no chemical bonds with either the crown or the tooth tissue; it is impossible for the cement to attain adequate retention force if it contracts in volume. Assuming that the cement contracts in volume after setting, the prosthesis tends to loose and is doomed to be hampered by fretting damage when it functions during the masticatory cycle; thus the prognosis for the prosthesis is questionable. However, zinc phosphate is popular because of its brilliant clinical record. This paradox between theory and practice indicates that something might be wrong with the standing theory. The most possible problem with previous studies is that their samples' dimensions differ from those that are used clinically, which causes the studies' results, which claim that the cement shrinks, to deviate from clinical results. The real rationale must be that the zinc phosphate cement tends to expand in volume, and thus mechanically fasten the crown to the abutment.

  2. A Novel Approach to Bioleach Soluble Phosphorus from Rock Phosphate

    Institute of Scientific and Technical Information of China (English)

    池汝安; 肖春桥; 黄晓慧; 王存文; 吴元欣

    2007-01-01

    A novel approach to bioleach soluble phosphorus from rock phosphate, involving the bio-oxidation of pyrite by adaptated Acidithiobacillus ferrooxidans (At. f) and the product of sulfuric acid to dissolve rock phosphate, has been proposed in this paper. The soluble phosphorus could be leached more effectively in the presence of pyrite by At. f than that leached directly by sulfuric acid. The optimal technological parameters are presented. The highest phosphorus leaching rate is 9.00% when the culture substrate is the mixture of FeSO4·7H2O and pyrite, the phosphorus leaching rate is 8.00% when the initial pH and culture time are 2.5 and 5 d, respectively. The optimal rock phosphate particle size is 0.05 mm for the leaching of phosphorus. The bigger the grains of pyrite, the lower the phosphorus leaching rate. The bacterium At. f should be appropriately adaptated, which makes it easier to bioleach soluble phosphorus from rock phosphate.

  3. Biochemistry and genetics of inositol phosphate metabolism in Dictyostelium

    NARCIS (Netherlands)

    vanHaastert, PJM; van Dijken, P.

    1997-01-01

    Biochemical and genetic data on the metabolism of inositol phosphates in the microorganism Dictyostelium are combined in a scheme composed of in five subroutes. The first subroute is the inositol cycle as found in other organisms:inositol is incorporated into phospholipids that are hydrolysed by PLC

  4. Adsorption of Phosphate on Goethite: An Undergraduate Research Laboratory Project

    Science.gov (United States)

    Tribe, Lorena; Barja, Beatriz C.

    2004-01-01

    A laboratory experiment on the adsorption of phosphate on goethite is presented, which also includes discussion on surface properties, interfaces, acid-base equilibrium, molecular structure and solid state chemistry. It was seen that many students were able to produce qualitatively correct results for a complex system of real interest and they…

  5. Microporous calcium phosphate ceramics driving osteogenesis through surface architecture

    NARCIS (Netherlands)

    Zhang, J.; Barbieri, D.; Hoopen, ten H.W.M.; Bruijn, de J.D.; Blitterswijk, van C.A.; Yuan, H.

    2015-01-01

    The presence of micropores in calcium phosphate (CaP) ceramics has shown its important role in initiating inductive bone formation in ectopic sites. To investigate how microporous CaP ceramics trigger osteoinduction, we optimized two biphasic CaP ceramics (i.e., BCP-R and BCP-S) to have the same che

  6. sphingosine-1-phosphate transport and its role in immunology

    NARCIS (Netherlands)

    Reitsema, V.; Bouma, Hjalmar; Kok, Jan

    2014-01-01

    Sphingosine-1-phosphate (S1P) is a sphingolipid metabolite with many important functions in cellular and systemic physiology, including the immune system. As it cannot traverse the membrane, it is exported from cells by transporters. Several members of the ATP-binding cassette (ABC) transporter fami

  7. A COMPARATIVE STUDY OF THE PHOSPHATE LEVELS IN SOME ...

    African Journals Online (AJOL)

    a

    both the surface and groundwater samples analyzed include industrial ... wastewater and septic system effluent, animal wastes, detergents, industrial discharge, phosphate mining, drinking water treatment, forest fires, synthetic material ... topography of the rainfall pattern, climate nature and frequency of sampling, biological ...

  8. OPTICALLY HOMOGENEOUS PHOSPHATE GLASSES DOPED WITH METAL NANOPARTICLES

    OpenAIRE

    Shakhgil'dyan, Georgiy; Savinkov, Vitaliy; Konev, Denis; Paleari, A.; Sigaev, Vladimir

    2013-01-01

    The technique of batch preparation, melting, glass working and nanoscale modification of the structure of phosphate glass doped with gold nanoparticles was developed. Glass samples containing different amounts of phosphorus oxide were synthesized. Heat treatments of the samples were held in a gradient furnace. Physical, spectral-luminescent and nonlinear optical properties of the samples were studied.

  9. Catalytic Kinetic Spectrophotometric Method for Determination of Phosphate Ion

    Institute of Scientific and Technical Information of China (English)

    MITIC,Snezana; ZIVANOVIC,Valentina; OBRADOVIC,Mirjana; TOSIC,Snezana; PAVLOVIC,Aleksandra

    2007-01-01

    The kinetic method for the determination of phosphate microamounts was described.The developed method is based on catalytic effect of phosphate on sodium pyrogallol-5-sulphonate(PS)by dissolved oxygen.The reaction was followed spectrophotometrically by measuring the rate of change in the values of the absorbance of the oxidation product at 437 nm.The optimum reaction conditions are PS(0.44×10-3 mol·L-1)and HClO4(3.6×10-6mol·L-1)at 25℃.Following this procedure,phosphate can be determined with a linear calibration graph up to 0.23 μg·mL-1.The interference effect of several species was also investigated and it was found that the most common cations and anions did not interfere with the determination.The developed procedure was successfully applied to the determination of phosphate in natural waters and soil.

  10. Atomic structure of intracellular amorphous calcium phosphate deposits.

    Science.gov (United States)

    Betts, F; Blumenthal, N C; Posner, A S; Becker, G L; Lehninger, A L

    1975-06-01

    The radial distribution function calculated from x-ray diffraction of mineralized cytoplasmic structures isolated from the hepatopancreas of the blue crab (Callinectes sapidus) is very similar to that previously found for synthetic amorphous calcium phosphate. Both types of mineral apparently have only short-range atomic order, represented as a neutral ion cluster of about 10 A in longest dimension, whose probable composition is expressed by the formula Ca9(PO4)6. The minor differences observed are attributed to the presence in the biological mineral of significant amounts of Mg-2+ and ATP. Synthetic amorphous calcium phosphate in contact with a solution containing an amount of ATP equivalent to that of the biological mineral failed to undergo conversion to the thermodynamically more stable hydroxyapatite. The amorphous calcium phosphate of the cytoplasmic mineral granules is similarly stable, and does not undergo conversion to hydroxyapatite, presumably owing to the presence of ATP and Mg-2+, known in inhibitors of the conversion process. The physiological implications of mineral deposits consisting of stabilized calcium phosphate ion clusters are discussed.

  11. lectrolytic deposition of lithium into calcium phosphate coatings

    NARCIS (Netherlands)

    Wang, Jiawei; Groot, de Klaas; Blitterswijk, van Clemens; Boer, de Jan

    2009-01-01

    Objectives: Lithium ions stimulate the Wnt signaling pathway and the authors previously demonstrated that lithium enhances the proliferation of tissue cultured human mesenchymal stem cells. The aim of this study was to prepare and characterize a calcium phosphate/lithium coating by means of electrol

  12. Durable phosphate-selective electrodes based on uranyl salophenes

    NARCIS (Netherlands)

    Wroblewski, Wojciech; Wojciechowski, Kamil; Dybko, Artur; Brzozka, Zbigniew; Egberink, Richard J.M.; Snellink-Ruel, Bianca H.M.; Reinhoudt, David N.

    2001-01-01

    Lipophilic uranyl salophenes derivatives were used as ionophores in durable phosphate-selective electrodes. The influence of the ionophore structure and membrane composition (polarity of plasticizer, the amount of incorporated ionic sites) on the electrode selectivity and long-term stability were st

  13. Study on Extraction Performance of Tri-iso-amyl Phosphate

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The distribution performance of HNO3, Pu(Ⅲ ), Pu(Ⅳ) and Np(Ⅳ) in the two phase system of Tri-iso-Amyl Phosphate(TiAP) and aqueous, the influence of the concentration of extractant, nitric acid and Al(NO3)3 on the distribution ratio of Pu(Ⅲ ),

  14. Recent revisions of phosphate rock reserves and resources: a critique

    NARCIS (Netherlands)

    Edixhoven, J.D.; Gupta, J.; Savenije, H.H.G.

    2014-01-01

    Phosphate rock (PR) is a finite mineral indispensable for fertilizer production, while P (phosphorus) is a major pollutant if applied or discharged in excess, causing widespread eutrophication (Carpenter and Bennet, 2011). High-grade PR is obtained from deposits which took millions of years to form

  15. Maxillary sinus augmentation with microstructured tricalcium phosphate ceramic in sheep.

    NARCIS (Netherlands)

    Klijn, R.J.; Hoekstra, J.W.M.; Beucken, J.J.J.P van den; Meijer, G.J.; Jansen, J.B.M.J.

    2012-01-01

    OBJECTIVE: The objective of this study was to evaluate the biological performance of osteoinductive microstructured tricalcium phosphate (MSTCP) particles in maxillary sinus floor augmentation surgery in sheep. MATERIAL AND METHODS: Sinus floor augmentation was performed in eight Swifter sheep. In e

  16. Resorption Rate Tunable Bioceramic: Si, Zn-Modified Tricalcium Phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Xiang [Iowa State Univ., Ames, IA (United States)

    2006-01-01

    This dissertation is organized in an alternate format. Several manuscripts which have already been published or are to be submitted for publication have been included as separate chapters. Chapter 1 is a general introduction which describes the dissertation organization and introduces the human bone and ceramic materials as bone substitute. Chapter 2 is the background and literature review on dissolution behavior of calcium phosphate, and discussion of motivation for this research. Chapter 3 is a manuscript entitled ''Si,Zn-modified tricalcium phosphate: a phase composition and crystal structure study'', which was published in ''Key Engineering Materials'' [1]. Chapter 4 gives more crystal structure details by neutron powder diffraction, which identifies the position for Si and Zn substitution and explains the stabilization mechanism of the structure. A manuscript entitled ''Crystal structure analysis of Si, Zn-modified Tricalcium phosphate by Neutron Powder Diffraction'' will be submitted to Biomaterials [2]. Chapter 5 is a manuscript, entitled ''Dissolution behavior and cytotoxicity test of Si, Zn-modified tricalcium phosphate'', which is to be submitted to Biomaterials [3]. This paper discusses the additives effect on the dissolution behavior of TCP, and cytotoxicity test result is also included. Chapter 6 is the study of hydrolysis process of {alpha}-tricalcium phosphate in the simulated body fluid, and the phase development during drying process is discussed. A manuscript entitled ''Hydrolysis of {alpha}-tricalcium phosphate in simulated body fluid and phase transformation during drying process'' is to be submitted to Biomaterials [4]. Ozan Ugurlu is included as co-authors in these two papers due to his TEM contributions. Appendix A is the general introduction of the materials synthesis, crystal structure and preliminary dissolution result. A manuscript entitled

  17. SCALEUP OF ALUMINUM PHOSPHATE CATALYST FOR PILOT PLANT LPDMEtm RUN

    Energy Technology Data Exchange (ETDEWEB)

    Andrew W. Wang

    2002-01-01

    The Liquid Phase Dimethyl Ether (LPDME{trademark}) process converts synthesis gas to dimethyl ether in a single slurry bubble column reactor. A mixed slurry of methanol synthesis catalyst and methanol dehydration catalyst in a neutral mineral oil simultaneously synthesizes methanol from syngas and converts some of it to dimethyl ether and water. The reaction scheme is shown below: 2H{sub 2} + CO = CH{sub 3}OH; 2CH{sub 3}OH = CH{sub 3}OCH{sub 3} + H{sub 2}O; H{sub 2}O + CO = CO{sub 2} + H{sub 2}. Most of the water produced in this reaction is converted to hydrogen by reduction with carbon monoxide (water gas shift reaction). This synergy permits higher per pass conversion than methanol synthesis alone. The enhancement in conversion occurs because dehydration of the methanol circumvents the equilibrium constraint of the syngas-to-methanol step. The slurry bubble column reactor provides the necessary heat transfer capacity to handle the greater heat duty associated with high conversion. In order to improve the stability of the catalyst system, non-stoichiometric aluminum phosphate was proposed as the dehydration catalyst for the LPDME{trademark} process. This aluminum phosphate material is a proprietary catalyst. This catalyst system of a standard methanol catalyst and the aluminum phosphate provided stable process performance that met the program targets under our standard test process conditions in the laboratory. These targets are (1) an initial methanol equivalent productivity of 28 gmol/kg/hr, (2) a CO{sub 2}-free, carbon selectivity of 80% to dimethyl ether and (3) stability of both catalysts equivalent to that of the methanol catalyst in the absence of the aluminum phosphate. A pilot plant trial of the LPDME{trademark} process using the aluminum phosphate catalyst was originally planned for March 1998 at the DOE-owned, Air Products (APCI)-operated facility at LaPorte, Texas. Because the aluminum phosphate catalyst is not commercially available, we initiated a

  18. SCALEUP OF ALUMINUM PHOSPHATE CATALYST FOR PILOT PLANT LPDMEtm RUN

    Energy Technology Data Exchange (ETDEWEB)

    Andrew W. Wang

    2002-05-15

    The Liquid Phase Dimethyl Ether (LPDME{trademark}) process converts synthesis gas to dimethyl ether in a single slurry bubble column reactor. A mixed slurry of methanol synthesis catalyst and methanol dehydration catalyst in a neutral mineral oil simultaneously synthesizes methanol from syngas and converts some of it to dimethyl ether and water. The reaction scheme is: 2H{sub 2} + CO = CH{sub 3}OH 2CH{sub 3}OH = CH{sub 3}OCH{sub 3} + H{sub 2}O H{sub 2}O + CO = CO{sub 2} + H{sub 2}. Most of the water produced in this reaction is converted to hydrogen by reduction with carbon monoxide (water gas shift reaction). This synergy permits higher per pass conversion than methanol synthesis alone. The enhancement in conversion occurs because dehydration of the methanol circumvents the equilibrium constraint of the syngas-to-methanol step. The slurry bubble column reactor provides the necessary heat transfer capacity to handle the greater heat duty associated with high conversion. In order to improve the stability of the catalyst system, non-stoichiometric aluminum phosphate was proposed as the dehydration catalyst for the LPDME{trademark} process. This aluminum phosphate material is a proprietary catalyst. This catalyst system of a standard methanol catalyst and the aluminum phosphate provided stable process performance that met the program targets under our standard test process conditions in the laboratory. These targets are (1) an initial methanol equivalent productivity of 28 gmol/kg/hr, (2) a CO{sub 2}-free, carbon selectivity of 80% to dimethyl ether and (3) stability of both catalysts equivalent to that of the methanol catalyst in the absence of the aluminum phosphate. A pilot plant trial of the LPDME{trademark} process using the aluminum phosphate catalyst was originally planned for March 1998 at the DOE-owned, Air Products (APCI)-operated facility at LaPorte, Texas. Because the aluminum phosphate catalyst is not commercially available, we initiated a scaleup project

  19. Miocene phosphate-rich sediments in Salento (southern Italy)

    Science.gov (United States)

    Föllmi, Karl B.; Hofmann, Hélène; Chiaradia, Massimo; de Kaenel, Eric; Frijia, Gianluca; Parente, Mariano

    2015-08-01

    The upper Middle to lower Upper Miocene (Serravallian to Tortonian) sedimentary succession in Salento (southern Italy) includes glauconite- and phosphate-rich deposits, which are associated with pelagic micrite. In Baia del Ciolo and Marittima (southern Salento), the succession is composed of shallow-water platform carbonates of Late Oligocene age (Chattian; Porto Badisco Formation), which are overlain by a 20- to 30-cm-thick level of glauconite-rich micrite with abundant reworked particles and fossils of the underlying Porto Badisco Formation. This interval is in turn covered by an up to 15 cm thick phosphatic crust ("Livello ad Aturia"), which itself is overlain either by a hemipelagic chalk-like carbonate of Middle to Late Miocene age ("Pietra Leccese"; Marittima) or directly by a micrite of Late Miocene age (Messinian; Novaglie Formation; Baia del Ciolo), which shallows upwards into a shallow-water platform carbonate. A large hiatus is present in this succession, which likely includes the Lower and lower Middle Miocene. In the region of Lecce, two discrete levels enriched in glauconite and phosphate-each associated with a major discontinuity-occur within the Pietra Leccese. The strontium-isotope ages derived on phosphate nodules and phosphatized and non-phosphatized fossils and calcareous nannofossil ages indicate a time interval of phosphogenesis between 13.5 and 7.5 Ma, with two clusters at 12 and 10.5 Ma. The glauconite and phosphate-rich sediments resulted from a current-dominated regime, which was characterized by low overall sedimentation rates, erosion and sediment reworking, and authigenesis. This regime was likely related to a generally westward-directed bottom current, which was forced to upwell once it arrived at the western border of the eastern Mediterranean basin. The timing of the principal phosphogenic phases can only partly be correlated to those of other occurrences in this part of the Mediterranean (Malta, Gozo, southern Sicily, Matese

  20. The Path of Carbon in Photosynthesis XIX. The Identification of Sucrose Phosphate in Sugar Beet Leaves

    Science.gov (United States)

    Buchanan, J. G.

    1952-09-01

    The recognition and characterization of a sucrose phosphate as an intermediate in sucrose by synthesis by green plants is described. A tentative structure for this phosphate is proposed and its mode of formation suggested.

  1. Method for Producing Chemically Bonded Phosphate Ceramics and for Stabilizing Contaminants Encapsulated therein Utilizing Reducing Agents

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Dileep; Wagh, Arun S.; Jeong, Seung-Young

    1999-05-05

    Known phosphate ceramic formulations are improved and the ability to produce iron-based phosphate ceramic systems is enabled by the addition of an oxidizing or reducing step during the acid-base reactions that form the phosphate ceramic products. The additives allow control of the rate of the acid-base reactions and concomitant heat generation. In an alternate embodiment, waste containing metal anions is stabilized in phosphate ceramic products by the addition of a reducing agent to the phosphate ceramic mixture. The reduced metal ions are more stable and/or reactive with the phosphate ions, resulting in the formation of insoluble metal species within the phosphate ceramic matrix, such that the resulting chemically bonded phosphate ceramic product has greater leach resistance.

  2. Phosphate DIstribution and Movement in Soil—Root Interface Zone:Ⅲ.Dynamics

    Institute of Scientific and Technical Information of China (English)

    XUMING-GANG; ZHANGYI-PING; 等

    1995-01-01

    The depletion rate of phosphate in the soil-root interface zone increased along with growth and phosphate uptske of wheat or maize,which indicated that the phosphate distribution in soil near the root surface agreed well with the phosphate movement in rhizosphere and phosphate uptake by plant,The relative accumulation zone of phosphate within 0.5mm apart from the root surface developed at the 15th day or so after cultivating wheat or maize since the root phosphate secretion increased gradually in this stage.The phosphate distribution in the soil-root interface zone against the growing time(t)and the distance from the root plane(x) could be described by the non-linear regression equation with the third powers of x and t.

  3. New agent to treat elevated phosphate levels: magnesium carbonate/calcium carbonate tablets.

    Science.gov (United States)

    Meyer, Caitlin; Cameron, Karen; Battistella, Marisa

    2012-01-01

    In summary, Binaphos CM, a magnesium carbonate/calcium carbonate combination phosphate binder, is marketed for treating elevated phosphate levels in dialysis patients. Although studies using magnesium/calcium carbonate as a phosphate binder are short term with small numbers of patients, this phosphate binder has shown some promising results and may provide clinicians with an alternative for phosphate binding. Using a combination phosphate binder may reduce pill burden and encourage patient compliance. In addition to calcium and phosphate, it is imperative to diligently monitor magnesium levels in patients started on this medication, as magnesium levels may increase with longer duration of use. Additional randomized controlled trials are necessary to evaluate long-term efficacy and safety of this combination phosphate binder.

  4. Fibroblast Growth Factor 23 (FGF23 and Disorders of Phosphate Metabolism

    Directory of Open Access Journals (Sweden)

    Tasuku Saito

    2009-01-01

    Full Text Available Derangements in serum phosphate level result in rickets/osteomalacia or ectopic calcification indicating that healthy people without these abnormalities maintain serum phosphate within certain ranges. These results indicate that there must be a regulatory mechanism of serum phosphate level. Fibroblast growth factor 23 (FGF23 was identified as the last member of FGF family. FGF23 is produced by bone and reduces serum phosphate level by suppressing phosphate reabsorption in proximal tubules and intestinal phosphate absorption through lowering 1,25-dihydroxyvitamin D level. It has been shown that excess and deficient actions of FGF23 result in hypophosphatemic rickets/osteomalacia and hyperphosphatemic tumoral calcinosis, respectively. These results indicate that FGF23 works as a hormone, and several disorders of phosphate metabolism can be viewed as endocrine diseases. It may become possible to treat patients with abnormal phosphate metabolism by pharmacologically modifying the activity of FGF23.

  5. Maillard Reactions of Ribose 5‐Phosphate and Amino Acids

    National Research Council Canada - National Science Library

    SANDWICK, ROGER; JOHANSON, MATTHEW; BREUER, ELIZABETH

    2005-01-01

    A bstract : An important metabolite in nucleotide synthesis, ribose 5‐phosphate (R5P) undergoes Maillard reactions at a rate significantly faster than most common sugars and sugar phosphates of its type...

  6. Interstitial and adsorbed phosphates in shelf sediments off Visakhapatnam, east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.; Raju, G.R.K.

    Spatial distribution of interstitial and adsorbed phosphates in the shelf sediments shows an increasing trend with distance from coastal to inshore region. Maximum concentration ranges of interstitial and adsorbed phosphates are 16-19 and 40-50 mu g...

  7. Comparison of efficacy of the phosphate binders nicotinic acid and sevelamer hydrochloride in hemodialysis patients

    National Research Council Canada - National Science Library

    Ahmadi, Farrokhlagha; Shamekhi, Fatemeh; Lessan-Pezeshki, Mahbob; Khatami, Mohammad Reza

    2012-01-01

    ...), and must be controlled with the use of phosphate binders. Studies comparing the effects of sevelamer and nicotinic acid, both similar non-calcium and non-aluminum phosphate binders, are not available...

  8. Radiological and chemical assessment of phosphate rocks in some countries

    Energy Technology Data Exchange (ETDEWEB)

    Cevik, U., E-mail: ugurc@ktu.edu.tr [Karadeniz Technical University, Department of Physics, Trabzon (Turkey); Baltas, H. [Rize University, Department of Physics, Rize (Turkey); Tabak, A. [Rize University, Department of Chemistry, Rize (Turkey); Damla, N. [Batman University, Department of Physics, Batman (Turkey)

    2010-10-15

    In this study, the radiological, structural and chemical characterizations of Mardin-Mazidagi phosphate rock, which is an important phosphate fertilizer source in Turkey were investigated and compared to those of several different phosphate rocks of Tunisia, Egypt, Morocco, Algeria and Syria using gamma spectrometry, X-ray diffraction (XRD) and X-ray fluorescence (XRF) measurement techniques. Elemental analysis results of phosphate samples showed that they were mainly composed of CaO, P{sub 2}O{sub 5}, SiO{sub 2}, Al{sub 2}O{sub 3}, SO{sub 3} and Fe{sub 2}O{sub 3}. Elemental concentrations of U and Th were calculated using {sup 226}Ra and {sup 232}Th activity concentrations, respectively. As a result of XRD analysis, the main peaks of the samples were found to be Fluorapatite (Ca{sub 5}(PO{sub 4}){sub 3}F). The radioactivity concentration levels for {sup 226}Ra, {sup 232}Th and {sup 40}K in all phosphate samples ranged from 250 to 1029 Bq kg{sup -1} with a mean of 535 Bq kg{sup -1}, from 5 to 50 Bq kg{sup -1} with a mean of 20 Bq kg{sup -1} and from 117 to 186 Bq kg{sup -1} with a mean of 148 Bq kg{sup -1}, respectively. The computed values of annual effective doses ranged from 0.17 to 0.59 mSv, with a mean value of 0.33 mSv, which is lower than the recommended limit of 1 mSv y{sup -1} by the International Commission on Radiological Protection.

  9. Decontamination of liquid radioactive waste by thorium phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Rousselle, J.; Grandjean, S.; Dacheux, N.; Genet, M

    2004-07-01

    In the field of the complete reexamination of the chemistry of thorium phosphate and of the improvement of the homogeneity of Thorium Phosphate Diphosphate (TPD, Th{sub 4}(PO{sub 4}){sub 4}P{sub 2}O{sub 7}) prepared at high temperature, several crystallized compounds were prepared as initial powdered precursors. Due to the very low solubility products associated to these phases, their use in the field of the efficient decontamination of high-level radioactive liquid waste containing actinides (An) was carefully considered. Two main processes (called 'oxalate' and 'hydrothermal' chemical routes) were developed through a new concept combining the decontamination of liquid waste and the immobilization of the actinides in a ceramic matrix (TPD). In phosphoric media ('hydrothermal route'), the key-precursor was the Thorium Phosphate Hydrogen Phosphate hydrate (Th{sub 2}(PO{sub 4}){sub 2}(HPO{sub 4}). H{sub 2}O, TPHP, solubility product log(K{sub S,0}{sup 0}) {approx} - 67). The replacement of thorium by other tetravalent actinides (U, Np, Pu) in the structure, leading to the preparation of Th{sub 2-x/2}An{sub x/2}(PO{sub 4}){sub 2}(HPO{sub 4}). H{sub 2}O solid solutions, was examined. A second method was also considered in parallel to illustrate this concept using the more well-known precipitation of oxalate as the initial decontamination step. For this method, the final transformation to single phase TPD containing actinides was purchased by heating a mixture of phosphate ions with the oxalate precipitate at high temperature. (authors)

  10. Uranium recovery from Uro area phosphate ore, Nuba Mountains, Sudan

    Directory of Open Access Journals (Sweden)

    Abdelmajid A. Adam

    2014-11-01

    Full Text Available This study was carried out in a laboratory scale to recover uranium from Uro area phosphate ore in the eastern part of Nuba Mountains in Sudan. Phosphate ore samples were collected, and analyzed for uranium abundance. The results showed that the samples contain a significant concentration of uranium with an average of 310.3 μg/g, which is 2.6 times higher than the world average of phosphate. The green phosphoric acid obtained from the samples was found to contain uranium in the range of 186–2049 μg/g, with an average of 603.3 μg/g, and about 98% of uranium content of the phosphate ore was rendered soluble in the phosphoric acid. An extraction process using 25% tributylphosphate, followed by stripping process using 0.5 M sodium carbonate reported that more than 98% of uranium in the green phosphoric acid exists as uranyl tricarbonate complex, moreover, sodic decomposition using 50% sodium hydroxide showed that about 98% of the uranium was precipitated as sodium diuranate concentrate that is known as the yellow cake (Na2U2O7. Further purification and calcinations of the yellow cake led to the formation of the orange powder of uranium trioxide (UO3. The chemical analysis of the obtained uranium concentrates; yellow cake and uranium trioxide proved their nuclear purity and that they meet the standard commercial specification. The obtained results proved that uranium from Uro phosphate ore was successfully recovered as uranium trioxide with an overall recovery percentage of 93%.

  11. Comparison of phosphate materials for immobilizing cadmium in soil.

    Science.gov (United States)

    Hong, Chang Oh; Chung, Doug Young; Lee, Do Kyoung; Kim, Pil Joo

    2010-02-01

    A study was conducted to compare the effects of phosphate (P) materials in reducing cadmium extractability. Seven P materials (commercial P fertilizers--fused phosphate (FP), 'fused and superphosphate' [FSP], and rock phosphate [RP]; P chemicals--Ca[H(2)PO(4)](2).H(2)O, [NH(4)](2)HPO(4), KH(2)PO(4), and K(2)HPO(4)) were selected for the test. The selected P source was mixed with Cd-contaminated soil at the rate of 0, 200, 400, 800, and 1,600 mg P kg(-1) under controlled moisture conditions at 70% of water holding capacity, then incubated for 8 weeks. FP, Ca(H(2)PO(4))(2) H(2)O, KH(2)PO(4), and K(2)HPO(4) significantly decreased NH(4)OAc-extractable Cd (plant-available form) concentrations with increasing application rates. Compared to other phosphate materials used, K(2)HPO(4) was found to be the most effective in reducing the plant-available Cd concentration in soil, mainly due to the negative charge increase caused by soil pH and phosphate adsorption. Contrary to the general information, FSP and (NH(4))(2)HPO(4) increased Cd extractability at low levels of P application (MINTEQ program were significantly increased by K(2)HPO(4) addition, but the effect of Cd-P compound formation on reducing Cd extractability was negligible. Conclusively, the P-induced alleviation of Cd extractability can be attributed primarily to Cd immobilization due to the increase in soil pH and negative charge rather than Cd-P precipitation, and therefore, alkaline P materials such as K(2)HPO(4) are effective for immobilizing soil Cd.

  12. Phosphate fertilizer impacts on glyphosate sorption by soil.

    Science.gov (United States)

    Munira, Sirajum; Farenhorst, Annemieke; Flaten, Don; Grant, Cynthia

    2016-06-01

    This research examined the impact of field-aged phosphate and cadmium (Cd) concentrations, and fresh phosphate co-applications, on glyphosate sorption by soil. Soil samples were collected in 2013 from research plots that had received, from 2002 to 2009, annual applications of mono ammonium phosphate (MAP) at 20, 40 and 80 kg P ha(-1) and from products containing 0.4, 70 or 210 mg Cd kg(-1) as an impurity. A series of batch equilibrium experiments were carried out to quantify the glyphosate sorption distribution constant, Kd. Extractable Cd concentrations in soil had no significant effect on glyphosate sorption. Glyphosate Kd values significantly decreased with increasing Olsen-P concentrations in soil, regardless of the pH conditions studied. Experiments repeated with a commercially available glyphosate formulation showed statistically similar results as the experiments performed with analytical-grade glyphosate. Co-applications of MAP with glyphosate also reduced the available sorption sites to retain glyphosate, but less so when soils already contain large amounts of phosphate. Glyphosate Kd values in soils ranged from 173 to 939 L kg(-1) under very strong to strongly acidic condition but the Kd was always alkaline conditions. The highest Olsen-P concentrations in soil reduced Kd values by 25-44% relative to control soils suggesting that, under moderately acidic to slightly alkaline conditions, glyphosate may become mobile by water in soils with high phosphate levels. Otherwise, glyphosate residues in agricultural soils are more likely to be transported off-site by wind and water-eroded sediments than by leaching or runoff.

  13. Internal loading of phosphate in Lake Erie Central Basin.

    Science.gov (United States)

    Paytan, Adina; Roberts, Kathryn; Watson, Sue; Peek, Sara; Chuang, Pei-Chuan; Defforey, Delphine; Kendall, Carol

    2017-02-01

    After significant reductions in external phosphorus (P) loads, and subsequent water quality improvements in the early 1980s, the water quality of Lake Erie has declined considerably over the past decade. The frequency and magnitude of harmful algal blooms (primarily in the western basin) and the extent of hypoxic bottom waters in the central basin have increased. The decline in ecosystem health, despite meeting goals for external P loads, has sparked a renewed effort to understand P cycling in the lake. We use pore-water P concentration profiles and sediment cores incubation experiments to quantify the P flux from Lake Erie central basin sediments. In addition, the oxygen isotopes of phosphate were investigated to assess the isotopic signature of sedimentary phosphate inputs relative to the isotopic signature of phosphate in lake water. Extrapolating the total P sediment flux based on the pore-water profiles to the whole area of the central basin ranged from 300 to 1250metric tons per year and using the flux based on core incubation experiments an annual flux of roughly 2400metric tons of P is calculated. These estimates amount to 8-20% of the total external input of P to Lake Erie. The isotopic signature of phosphate in the extractable fraction of the sediments (~18‰) can explain the non-equilibrium isotope values of dissolved phosphate in the deep water of the central basin of Lake Erie, and this is consistent with sediments as an important internal source of P in the Lake. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. ETUDE DES REMANIEMENTS LIPIDIQUES DES CELLULES VEGETALES EN CARENCE DE PHOSPHATE

    OpenAIRE

    Jouhet, Juliette

    2005-01-01

    Phosphate is often a limiting factor for plant growth in soil. In plant cell, phosphate deprivation induces a decrease of phospholipid amount, mobilizing phosphate present in theses molecules. This decrease is compensated by an increase of non phosphorous plastidic glycolipid amount such as digalactosyldiacylglycerol (DGDG). We have shown that under phosphate deprivation a part of phospholipids is transformed into phosphatidylcholine (PC), producing a transitory increase of PC in short time o...

  15. Phosphate-solubilizing microbes and their occurrence in the rhizospheres of Piper betel in Karnataka, India

    OpenAIRE

    TALLAPRAGADA, Padmavathi; SESHACHALA, Usha

    2012-01-01

    Low phosphate solubility is one of the most important factors limiting the plant growth in Indian soils. Many microorganisms can enhance phosphate solubility, but little is known about the magnitude of their phosphorus-solubilizing ability. The native populations of phosphate-solubilizing bacteria and fungi were studied in different rhizospheric soil samples obtained from betel vine plants (Piper betel L.) in order to compare the results. The present study focuses on the phosphate-solubilizin...

  16. Polymer Coating for Immobilizing Soluble Ions in a Phosphate Ceramic Product

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Dileep; Wagh, Arun S.; Patel, Kartikey D.

    1999-05-05

    A polymer coating is applied to the surface of a phosphate ceramic composite to effectively immobilize soluble salt anions encapsulated within the phosphate ceramic composite. The polymer coating is made from ceramic materials, including at least one inorganic metal compound, that wet and adhere to the surface structure of the phosphate ceramic composite, thereby isolating the soluble salt anions from the environment and ensuring long-term integrity of the phosphate ceramic composite.

  17. In vivo behavior of a novel injectable calcium phosphate cement compared with two other commercially available calcium phosphate cements.

    NARCIS (Netherlands)

    Hannink, G.; Wolke, J.G.C.; Schreurs, B.W.; Buma, P.

    2008-01-01

    The aim of this study was to investigate the physicochemical and biological properties of a newly developed calcium phosphate cement (CPC). The novel cement was compared with two other commercially available CPCs. After mixing the powder and liquid phase, the CPCs were injected as a paste into a rab

  18. From energy-rich phosphate compounds to warfare agents: A review on the chemistry of organic phosphate compounds

    Directory of Open Access Journals (Sweden)

    Luciano Albino Giusti

    2008-12-01

    Full Text Available The chemistry of the phosphorus-oxygen bond is widely used in biological systems in many processes, such as energy transduction and the storage, transmission and expression of genetic information, which are essential to living beings in relation to a wide variety of functions. Compounds containing this bond have been designed for many purposes, ranging from agricultural defense systems, in order to increase food production, to nerve agents, for complaining use in warfare. In this review, features related to the chemistry of organic phosphate compounds are discussed, with particular emphasis on the role of phosphate compounds in biochemical events and in nerve agents. To this aim, the energy-rich phosphate compounds are focused, particularly the mode of their use as energy currency in cells. Historical and recent studies carried out by research groups have tried to elucidate the mechanism of action of enzymes responsible for energy transduction through the use of biochemical studies, enzyme models, and artificial enzymes. Finally, recent studies on the detoxification of nerve agents based on phosphorous esters are presented, and on the utilization of chromogenic and fluorogenic chemosensors for the detection of these phosphate species.

  19. Structural Basis for Substrate Specificity in Phosphate Binding (beta/alpha)8-Barrels: D-Allulose 6-Phosphate 3-Epimerase from Escherichia coli K-12

    Energy Technology Data Exchange (ETDEWEB)

    Chan,K.; Fedorov, A.; Almo, S.; Gerlt, J.

    2008-01-01

    Enzymes that share the ({beta}/{alpha})8-barrel fold catalyze a diverse range of reactions. Many utilize phosphorylated substrates and share a conserved C-terminal ({beta}/a)2-quarter barrel subdomain that provides a binding motif for the dianionic phosphate group. We recently reported functional and structural studies of d-ribulose 5-phosphate 3-epimerase (RPE) from Streptococcus pyogenes that catalyzes the equilibration of the pentulose 5-phosphates d-ribulose 5-phosphate and d-xylulose 5-phosphate in the pentose phosphate pathway [J. Akana, A. A. Fedorov, E. Fedorov, W. R. P. Novack, P. C. Babbitt, S. C. Almo, and J. A. Gerlt (2006) Biochemistry 45, 2493-2503]. We now report functional and structural studies of d-allulose 6-phosphate 3-epimerase (ALSE) from Escherichia coli K-12 that catalyzes the equilibration of the hexulose 6-phosphates d-allulose 6-phosphate and d-fructose 6-phosphate in a catabolic pathway for d-allose. ALSE and RPE prefer their physiological substrates but are promiscuous for each other's substrate. The active sites (RPE complexed with d-xylitol 5-phosphate and ALSE complexed with d-glucitol 6-phosphate) are superimposable (as expected from their 39% sequence identity), with the exception of the phosphate binding motif. The loop following the eighth {beta}-strand in ALSE is one residue longer than the homologous loop in RPE, so the binding site for the hexulose 6-phosphate substrate/product in ALSE is elongated relative to that for the pentulose 5-phosphate substrate/product in RPE. We constructed three single-residue deletion mutants of the loop in ALSE, ?T196, ?S197 and ?G198, to investigate the structural bases for the differing substrate specificities; for each, the promiscuity is altered so that d-ribulose 5-phosphate is the preferred substrate. The changes in kcat/Km are dominated by changes in kcat, suggesting that substrate discrimination results from differential transition state stabilization. In both ALSE and RPE, the

  20. Characterization of Phosphate Solubilizing and Potassium Decomposing Strains and Study on their Effects on Tomato Cultivation

    OpenAIRE

    Tin Mar Lynn; Hlaing Swe Win; Ei Phyu Kyaw; Zaw Ko Latt; San San Yu

    2013-01-01

    Seven strains were collected for phosphate solubilizing and potassium decomposing activities from Microbiology Laboratory, Department of Biotechnology, Shweziwa Biofertilizer Plant. When phosphate solubilizing activity of selected strains was qualitatively determined, all strains except from B1 strain, gave clear zone formation on NBRIP media. But when quantitatively determined by spectrophotometric method, all strains solubilized insoluble tricalcium phosphate. Among seven strains, Ps strain...