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Sample records for 21s beta-tricalcium phosphate

  1. Experimental posterolateral spinal fusion with beta tricalcium phosphate ceramic and bone marrow aspirate composite graft

    PubMed Central

    Gupta, Ankit; Chauhan, Vijendra; Chauhan, Neena; Sharma, Sansar; Maheshwari, Rajesh; Agarwal, Atul

    2010-01-01

    Background: Beta tricalcium phosphate is commonly used in metaphyseal defects but its use in posterolateral spinal fusion remains controversial. There are very few published animal studies in which use of beta tricalcium phosphate has been evaluated in the posterolateral lumbar arthrodesis model. Hence we conducted a study to evaluate the potential of composite graft of beta tricalcium phosphate and bone marrow aspirate in comparison to autologous bone graft, when used for posterolateral spinal fusion. Materials and Methods: Single level posterolateral lumbar fusion was performed in 40 adult male Indian rabbits, which were assigned randomly into one of the four groups based on graft materials implanted; a) 3 gm beta tricalcium phosphate plus 3 ml bone marrow aspirate (Group I); b) 3 ml bone marrow aspirate alone (Group II); c) 3 gm beta tricalcium phosphate (Group III) and d) 3 gm autologous bone graft (Group IV). Each group had 10 rabbits. Half of the rabbits were sacrificed by injecting Phenobarbitone intraperitoneally after eight weeks and the remaining after 24 weeks, and were evaluated for fusion by X-rays, computed tomography (CT) scans, manual palpation test and histology. Results: Beta tricalcium phosphate used with bone marrow aspirate produced best results when compared to other groups (P =.0001). When beta tricalcium phosphate was used alone, fusion rates were better as compared to fusion achieved with autologous iliac crest bone graft though statistically not significant (P =0.07). Autologous bone graft showed signs of new bone formation. However, the rate of new bone formation was comparatively slow. Conclusion: Composite graft of beta tricalcium phosphate and bone marrow aspirate can be used as an alternative to autologous iliac crest bone graft. PMID:20924481

  2. Histological assessment in grafts of highly purified beta-tricalcium phosphate (OSferion) in human bones.

    PubMed

    Ogose, Akira; Kondo, Naoki; Umezu, Hajime; Hotta, Tetsuo; Kawashima, Hiroyuki; Tokunaga, Kunihiko; Ito, Tomoyuki; Kudo, Naoko; Hoshino, Makiko; Gu, Wenguang; Endo, Naoto

    2006-03-01

    Prominent osteoconductive activity and the biodegradable nature of commercially available beta-tricalcium phosphate (beta-TCP, OSferion) have been documented in animal experiments. We analyzed four cases of involving grafted OSferion in human bone with respect to histological features by routine hematoxylin and eosin staining, silver impregnation, immunohistochemistry and in situ hybridization. OSferion affords early bioresorption by osteoclasts, vascular invasion of macropores and osteoblastic cell attachment on the surface on the ceramic surface 14 days after grafting. Prominent bone formation and direct bone connection between preexisting bone and OSferion were evident 28 days after grafting. Nearly the entire TCP surface was covered by lamellar bone; additionally, active osteoblastic lining and attachment of the osteoclast-like giant cells were not observed 72 weeks after grafting. Silver impregnation revealed the presence of collagen fibrils within probable micropores of OSferion. PMID:16165205

  3. Sintering and robocasting of beta-tricalcium phosphate scaffoldsfor orthopaedic applications

    SciTech Connect

    Miranda, Pedro; Saiz, Eduardo; Gryn Karol; Tomsia, Antoni P.

    2005-11-01

    {beta}-tricalcium phosphate ({beta}-TCP) scaffolds with designed, three-dimensional (3-D) geometry and mesoscale porosity have been fabricated by direct-write assembly (robocasting) techniques. Concentrated {beta}-TCP inks with suitable viscoelastic properties were developed to enable the fabrication of the complex 3-D structures. A comprehensive study of the sintering behavior of TCP as a function of the calcium content in the starting powder was also carried out, and the optimal heat treatment for fabricating scaffolds with dense {beta}-TCP rods has been determined. Such analysis provides clues to controlling the microstructure of the fabricated structures and, therefore, enabling the fabrication by robocasting of TCP scaffolds with tailored performance for bone tissue engineering applications.

  4. Collagen/Beta-Tricalcium Phosphate Based Synthetic Bone Grafts via Dehydrothermal Processing.

    PubMed

    Sarikaya, Burcu; Aydin, Halil Murat

    2015-01-01

    Millions of patients worldwide remain inadequately treated for bone defects related to factors such as disease or trauma. The drawbacks of metallic implant and autograft/allograft use have steered therapeutic approaches towards tissue engineering solutions involving tissue regeneration scaffolds. This study proposes a composite scaffold with properties tailored to address the macro- and microenvironmental conditions deemed necessary for successful regeneration of bone in defect areas. The biodegradable scaffold composed of porous beta-tricalcium phosphate particles and collagen type I fibers is prepared from a mixture of collagen type-I and β-tricalcium phosphate (β-TCP) particles via lyophilization, followed by dehydrothermal (DHT) processing. The effects of both sterilization via gamma radiation and the use of DHT processing to achieve cross-linking were investigated. The impact of the chosen fabrication methods on scaffold microstructure and β-TCP particle-collagen fiber combinations were analyzed using X-ray diffractometry (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and microcomputerized tomography (µ-CT). Electron spinning resonance (ESR) analysis was used to investigate free radicals formation following sterilization. Results revealed that the highly porous (65% porosity at an average of 100 µm pore size), mechanically adequate, and biocompatible scaffolds can be utilized for bone defect repairs. PMID:26504812

  5. Collagen/Beta-Tricalcium Phosphate Based Synthetic Bone Grafts via Dehydrothermal Processing

    PubMed Central

    Sarikaya, Burcu; Aydin, Halil Murat

    2015-01-01

    Millions of patients worldwide remain inadequately treated for bone defects related to factors such as disease or trauma. The drawbacks of metallic implant and autograft/allograft use have steered therapeutic approaches towards tissue engineering solutions involving tissue regeneration scaffolds. This study proposes a composite scaffold with properties tailored to address the macro- and microenvironmental conditions deemed necessary for successful regeneration of bone in defect areas. The biodegradable scaffold composed of porous beta-tricalcium phosphate particles and collagen type I fibers is prepared from a mixture of collagen type-I and β-tricalcium phosphate (β-TCP) particles via lyophilization, followed by dehydrothermal (DHT) processing. The effects of both sterilization via gamma radiation and the use of DHT processing to achieve cross-linking were investigated. The impact of the chosen fabrication methods on scaffold microstructure and β-TCP particle-collagen fiber combinations were analyzed using X-ray diffractometry (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and microcomputerized tomography (µ-CT). Electron spinning resonance (ESR) analysis was used to investigate free radicals formation following sterilization. Results revealed that the highly porous (65% porosity at an average of 100 µm pore size), mechanically adequate, and biocompatible scaffolds can be utilized for bone defect repairs. PMID:26504812

  6. Synthesis and characterization of magnesium substituted biphasic mixtures of controlled hydroxyapatite/{beta}-tricalcium phosphate ratios

    SciTech Connect

    Kannan, S.; Lemos, I.A.F.; Rocha, J.H.G.; Ferreira, J.M.F. . E-mail: jmf@cv.ua.pt

    2005-10-15

    The present paper investigates the preparation of magnesium (Mg) substituted biphasic mixtures of different hydroxyapatite (HAP)/{beta}-tricalcium phosphate ({beta}-TCP) ratios through aqueous precipitation method. The concentrations of added magnesium (Mg) were varied with the calcium in order to obtain constant (Ca+Mg)/P ratios of 1.67 ranging from 1.62+0.05, 1.58+0.09 and 1.54+0.13, respectively. The as prepared powders were calcined at different temperatures to study the phase behaviour and thermal stability. The powders were characterized by the following analytical techniques: TG-DTA, X-ray diffraction and FT-IR. The results have shown that substitution of Mg in the calcium-deficient apatites resulted in the formation of biphasic mixtures of different HAP/{beta}-TCP ratios after heating above 700 deg. C. The ratios of the formation of phase mixtures were dependent on the calcium deficiency in the apatites with the higher deficiency having the strongest impact on the increased formation of {beta}-TCP and the substituted Mg was found to stabilize the {beta}-TCP phase. - Graphical abstract: Role of Mg in the behaviour of calcium-deficient apatites during calcination to form biphasic mixtures.

  7. Evaluation of suitable porosity for sintered porous {beta}-tricalcium phosphate as a bone substitute

    SciTech Connect

    Park, Jin-Hong; Bae, Ji-Yong; Shim, Jaebum; Jeon, Insu

    2012-09-15

    Structural and mechanical characterization is performed for sintered porous beta tricalcium phosphate ({beta}-TCP) to determine the appropriate porosity for use as a bone substitute. Four different types of porous {beta}-TCP specimen with different porosities are fabricated through a sintering process. For structural characterization, scanning electron microscopy and a Microfocus X-ray computed tomography system are used to investigate the pore openings on the specimen's surface, pore size, pore distribution, and pore interconnections. Compression tests of the specimens are performed, and mechanical properties such as the elastic modulus and compressive strength are obtained. Also, the geometric shape and volume of the {beta}-TCP around the contact region of two pores, which need to be initially resolved after implantation in order to increase the size of the pore openings, are evaluated through simple calculations. The results show that porous {beta}-TCP with 42.1% porosity may be a suitable bone substitute candidate in terms of sustaining external loads, and inducing and cultivating bone cells. - Highlights: Black-Right-Pointing-Pointer Structural and mechanical characterization was performed for sintered porous {beta}-TCP specimens. Black-Right-Pointing-Pointer For structural characterization, SEM and Microfocus X-ray CT system were used. Black-Right-Pointing-Pointer For mechanical characterization, compression tests were performed. Black-Right-Pointing-Pointer Porous {beta}-TCP with 42.1% porosity may be a suitable bone substitute.

  8. Microstereolithography-Based Fabrication of Anatomically Shaped Beta-Tricalcium Phosphate Scaffolds for Bone Tissue Engineering

    PubMed Central

    Du, Dajiang; Asaoka, Teruo; Shinohara, Makoto; Kageyama, Tomonori; Ushida, Takashi; Furukawa, Katsuko Sakai

    2015-01-01

    Porous ceramic scaffolds with shapes matching the bone defects may result in more efficient grafting and healing than the ones with simple geometries. Using computer-assisted microstereolithography (MSTL), we have developed a novel gelcasting indirect MSTL technology and successfully fabricated two scaffolds according to CT images of rabbit femur. Negative resin molds with outer 3D dimensions conforming to the femur and an internal structure consisting of stacked meshes with uniform interconnecting struts, 0.5 mm in diameter, were fabricated by MSTL. The second mold type was designed for cortical bone formation. A ceramic slurry of beta-tricalcium phosphate (β-TCP) with room temperature vulcanization (RTV) silicone as binder was cast into the molds. After the RTV silicone was completely cured, the composite was sintered at 1500°C for 5 h. Both gross anatomical shape and the interpenetrating internal network were preserved after sintering. Even cortical structure could be introduced into the customized scaffolds, which resulted in enhanced strength. Biocompatibility was confirmed by vital staining of rabbit bone marrow mesenchymal stromal cells cultured on the customized scaffolds for 5 days. This fabrication method could be useful for constructing bone substitutes specifically designed according to local anatomical defects. PMID:26504839

  9. Microstereolithography-Based Fabrication of Anatomically Shaped Beta-Tricalcium Phosphate Scaffolds for Bone Tissue Engineering.

    PubMed

    Du, Dajiang; Asaoka, Teruo; Shinohara, Makoto; Kageyama, Tomonori; Ushida, Takashi; Furukawa, Katsuko Sakai

    2015-01-01

    Porous ceramic scaffolds with shapes matching the bone defects may result in more efficient grafting and healing than the ones with simple geometries. Using computer-assisted microstereolithography (MSTL), we have developed a novel gelcasting indirect MSTL technology and successfully fabricated two scaffolds according to CT images of rabbit femur. Negative resin molds with outer 3D dimensions conforming to the femur and an internal structure consisting of stacked meshes with uniform interconnecting struts, 0.5 mm in diameter, were fabricated by MSTL. The second mold type was designed for cortical bone formation. A ceramic slurry of beta-tricalcium phosphate (β-TCP) with room temperature vulcanization (RTV) silicone as binder was cast into the molds. After the RTV silicone was completely cured, the composite was sintered at 1500°C for 5 h. Both gross anatomical shape and the interpenetrating internal network were preserved after sintering. Even cortical structure could be introduced into the customized scaffolds, which resulted in enhanced strength. Biocompatibility was confirmed by vital staining of rabbit bone marrow mesenchymal stromal cells cultured on the customized scaffolds for 5 days. This fabrication method could be useful for constructing bone substitutes specifically designed according to local anatomical defects. PMID:26504839

  10. Effect of Doping on beta-Tricalcium Phosphate Bioresorbable Bulk Material and Thin Film Coatings

    NASA Astrophysics Data System (ADS)

    Abdalla, Suhaila

    Magnesium has emerged as a revolutionary biodegradable metal for use as an orthopedic material, it has several advantages over the current metallic materials in use, including eliminating the effects of stress shielding, improving biocompatibility and inhibiting degradation rates, thus removing the requirement of a second surgery for implant removal. Due to the rapid degradation of magnesium, it is necessary to control the corrosion rates of the materials to match the rates of bone healing. This dissertation reports on the effect of doping on the properties of beta-tricalcium phosphate (beta-TCP). It also reports on its application as a thin film coating on magnesium alloys for implant applications. Adding various dopants to beta-TCP significantly influences critical properties. In this study, discs were fabricated in two compositions: (i) undoped beta-TCP, (ii) beta-TCP doped with 1.0 wt % MgO, 0.5 wt % ZnO, and 1.0 wt % TiO2. Films were fabricated from these compositions using the pulsed laser deposition (PLD) technique. These coatings were then characterized for corrosive, hardness, and cytocompatibility. The XRD patterns of the coating confirm the amorphous nature of the films. The presence of the metal oxides in beta-TCP improved ceramic densification. The application of these doped coatings was also found to increase the hardness by 88 %, the modulus of elasticity by 66 %, and improve corrosion resistance of the magnesium alloy substrate; with a 2.4 % improvement in Ecorr and 95 % decrease in icorr. Cell viability was studied using an osteoblast precursor cell line MC3T3-E1 to assure that the biocompatibility of these ceramics was not altered due to the dopants. Long-term biodegradation studies were conducted by measuring weight change and surface microstructure as a function of time in simulated body fluid. The results suggest that these coatings could be used for bioresorbable implants with improved corrosion resistance and increased hardness.

  11. Novel bioactive composite bone cements based on the beta-tricalcium phosphate-monocalcium phosphate monohydrate composite cement system.

    PubMed

    Huan, Zhiguang; Chang, Jiang

    2009-05-01

    Bioactive composite bone cements were obtained by incorporation of tricalcium silicate (Ca3SiO5, C3S) into a brushite bone cement composed of beta-tricalcium phosphate [beta-Ca3(PO4)2, beta-TCP] and monocalcium phosphate monohydrate [Ca(H2PO4)2.H2O, MCPM], and the properties of the new cements were studied and compared with pure brushite cement. The results indicated that the injectability, setting time and short- and long-term mechanical strength of the material are higher than those of pure brushite cement, and the compressive strength of the TCP/MCPM/C3S composite paste increased with increasing aging time. Moreover, the TCP/MCPM/C3S specimens showed significantly improved in vitro bioactivity in simulated body fluid and similar degradability in phosphate-buffered saline as compared with brushite cement. Additionally, the reacted TCP/MCPM/C3S paste possesses the ability to stimulate osteoblast proliferation and promote osteoblastic differentiation of the bone marrow stromal cells. The results indicated that the TCP/MCPM/C3S cements may be used as a bioactive material for bone regeneration, and might have significant clinical advantage over the traditional beta-TCP/MCPM brushite cement. PMID:18996779

  12. Coverage of gingival recession defects using acellular dermal matrix allograft with or without beta-tricalcium phosphate.

    PubMed

    Okubo, Nobuki; Fujita, Takahisa; Ishii, Yoshihito; Ota, Mikio; Shibukawa, Yoshihiro; Yamada, Satoru

    2013-01-01

    The aim of this study was to investigate the effect of beta-tricalcium phosphate (β-TCP) particles in combination with acellular dermal matrix (ADM) allograft in gingival recession. Experimental gingival recession defects were created in beagle dogs and randomly assigned to one of the following groups: ADM, ADM + β-TCP, or coronally positioned flap (CPF; control). Tissues were histologically examined at 4, 8, or 16 weeks following treatment. A greater thickness of gingiva was observed at the sites treated in both the ADM + β-TCP and ADM groups than in the CPF group. The ADM + β-TCP group showed a statistically significant increase in both new bone and cementum formations compared to the ADM group. The results suggest that the combination of β-TCP and ADM is more effective in promoting new bone and cementum formations than ADM graft alone. PMID:21862508

  13. Three-Dimensional Molding Based on Microstereolithography Using Beta-Tricalcium Phosphate Slurry for the Production of Bioceramic Scaffolds

    NASA Astrophysics Data System (ADS)

    Torii, Takashi; Inada, Makoto; Maruo, Shoji

    2011-06-01

    We report on a three-dimensional (3D) molding technique of fabricating bioceramic scaffolds. In this method, ceramic slurry is cast into a 3D polymer master mold, which is fabricated via microstereolithography, by a centrifugal casting method. The polymer master mold is thermally decomposed, so that a complex 3D bioceramic scaffold can be produced. In experiments, the decomposition process of the polymer model was optimized by the master decomposition curve theory to reduce harmful cracks in a green body. As a result, we could produce not only precise lattice models but also a sophisticated porous scaffold using beta-tricalcium phosphate (β-TCP) slurry. This bioceramic 3D molding technique based on microstereolithography will be useful for tailor-made tissue engineering and regeneration medicine.

  14. Synthesis and characterization of sintered beta-tricalcium phosphate: A comparative study on the effect of preparation route.

    PubMed

    Ghosh, Rupita; Sarkar, Ritwik

    2016-10-01

    Beta-tricalcium phosphate (β-TCP) was prepared by three different routes namely, wet chemical coprecipitation, sol-gel and solution combustion synthesis. The synthesized powders were calcined at different temperatures and characterized for phase evolution study, thermal analysis, Fourier transform infrared (FTIR) spectroscopy, microstructural study for comparative analysis. The optimal thermal treatment required to prepare pure β-TCP powders was determined and after calcination of the synthesize powders prepared by different routes, pure β-TCP was obtained. The sintering temperature required to prepare fully dense β-TCP completely free from α-form was identified. The powders were then used to make dense and compact bodies sintered at 1200 and 1250°C. The sintering behaviour of the dense bodies was analysed using dilatometry, densification and microstructural study. It was found that the pellet prepared from powder synthesized via co-precipitation route attained maximum density compared to the pellets prepared from powders synthesized via sol-gel and solution combustion route. PMID:27287130

  15. Regeneration of periodontal tissues in non-human primates with rhGDF-5 and beta-tricalcium phosphate.

    PubMed

    Emerton, K B; Drapeau, S J; Prasad, H; Rohrer, M; Roffe, P; Hopper, K; Schoolfield, J; Jones, A; Cochran, D L

    2011-12-01

    The application of growth factors has been advocated in support of periodontal regeneration. Recombinant human growth and differentiation factor-5 (rhGDF-5), a member of the bone morphogenetic protein family, has been used to encourage periodontal tissue regeneration. This study evaluated the dose response of rhGDF-5 lyophilized onto beta-tricalcium phosphate (bTCP) granules for periodontal tissue regeneration in a baboon model. Periodontal defects were created bilaterally in 12 baboons by a split-mouth design. Plaque was allowed to accumulate around wire ligatures to create chronic disease. After 2 mos, the ligatures were removed, and a notch was placed at the base of the defect. Two teeth on each side of the mouth were randomly treated with bTCP only, 0.5, 1.0, or 2.0 mg rhGDF-5/g bTCP. Animals were sacrificed 5 mos post-treatment, with micro-CT and histomorphometric analysis performed. After 5 mos, analysis showed alveolar bone, cementum, and periodontal ligament formation in all treatment groups, with a dose-dependent increase in rhGDF-5-treated groups. Height of periodontal tissues also increased with the addition of rhGDF-5, and the amount of residual graft material decreased with rhGDF-5 treatment. Therefore, rhGDF-5 delivered on bTCP demonstrated effective regeneration of all 3 tissues critical for periodontal repair. PMID:21940517

  16. Human Adipose-Derived Stem Cells on Rapid Prototyped Three-Dimensional Hydroxyapatite/Beta-Tricalcium Phosphate Scaffold.

    PubMed

    Canciani, Elena; Dellavia, Claudia; Ferreira, Lorena Maria; Giannasi, Chiara; Carmagnola, Daniela; Carrassi, Antonio; Brini, Anna Teresa

    2016-05-01

    In the study, we assess a rapid prototyped scaffold composed of 30/70 hydroxyapatite (HA) and beta-tricalcium-phosphate (β-TCP) loaded with human adipose-derived stem cells (hASCs) to determine cell proliferation, differentiation toward osteogenic lineage, adhesion and penetration on/into the scaffold.In this in vitro study, hASCs isolated from fat tissue discarded after plastic surgery were expanded, characterized, and then loaded onto the scaffold. Cells were tested for: viability assay (Alamar Blue at days 3, 7 and Live/Dead at day 32), differentiation index (alkaline phosphatase activity at day 14), scaffold adhesion (standard error of the mean analysis at days 5 and 18), and penetration (ground sections at day 32).All the hASC populations displayed stemness markers and the ability to differentiate toward adipogenic and osteogenic lineages.Cellular vitality increased between 3 and 7 days, and no inhibitory effect by HA/β-TCP was observed. Under osteogenic stimuli, scaffold increased alkaline phosphatase activity of +243% compared with undifferentiated samples. Human adipose-derived stem cells adhered on HA/β-TCP surface through citoplasmatic extensions that occupied the macropores and built networks among them. Human adipose derived stem cells were observed in the core of HA/β-TCP. The current combination of hASCs and HA/β-TCP scaffold provided encouraging results. If authors' data will be confirmed in preclinical models, the present engineering approach could represent an interesting tool in treating large bone defects. PMID:27092915

  17. Preparation and characterization of beta-tricalcium phosphate co-doped with monovalent and divalent antibacterial metal ions.

    PubMed

    Matsumoto, N; Sato, K; Yoshida, K; Hashimoto, K; Toda, Y

    2009-10-01

    Ag(+) and Zn(2+) or Cu(2+) ions were co-doped with beta-tricalcium phosphate (AgZn-TCP and AgCu-TCP), and their substitution models, antimicrobial activities, mechanisms and cytotoxicities were investigated. The lattice constants (a-axis and c-axis) of AgZn-TCP and AgCu-TCP decreased linearly with the amount of Zn(2+) or Cu(2+) ions up to 9.09 mol.%, which indicated that Ag(+) ions were doped at the Ca(4) site and a vacancy in the beta-TCP structure, and Zn(2+) or Cu(2+) ions were doped at the Ca(5) site. Antibacterial activities of AgZn-TCP and AgCu-TCP on Escherichia coli and Staphylococcus aureus were higher than those of Ag(+) ions-doped beta-TCP (Ag-TCP) and pure beta-TCP. These antimicrobial activities suggested that an interaction occurred between bacteria and Ag(+), Zn(2+) and Cu(2+) ions eluted from AgZn-TCP and AgCu-TCP and between bacteria and the free radicals generated by antibacterial agents or in bacterial cells. AgZn-TCP and AgCu-TCP can be used over long periods of time with high antimicrobial activity, because the rate at which Ag(+) ions are released from AgZn-TCP and AgCu-TCP is slower than that at which Ag(+) ions are released from Ag-TCP. However, it is necessary to determine the suitable amounts of Ag(+), Zn(2+) and Cu(2+) ions in AgZn-TCP and AgCu-TCP by considering both their antimicrobial activities and cytotoxicities, because beta-TCP doped with a large amount of these metal ions exhibits cytotoxicity. Furthermore, AgZn-TCP and AgCu-TCP are considered to be promising materials for use in various fields. PMID:19435618

  18. Biological responses of brushite-forming Zn- and ZnSr- substituted beta-tricalcium phosphate bone cements.

    PubMed

    Pina, S; Vieira, S I; Rego, P; Torres, P M C; da Cruz e Silva, O A B; da Cruz e Silva, E F; Ferreira, J M F

    2010-01-01

    The core aim of this study was to investigate zinc (Zn)- and zinc and strontium (ZnSr)-containing brushite-forming beta-tricalcium phosphate (TCP) cements for their effects on proliferation and differentiation of osteoblastic-like cells (MC3T3-E1 cell line) as well as for their in vivo behaviour in trabecular bone cylindrical defects in a pilot study. In vitro proliferation and maturation responses of MC3T3-E1 osteoblastic-like cells to bone cements were studied at the cellular and molecular levels. The Zn- and Sr-containing brushite cements were found to stimulate pre-osteoblastic proliferation and osteoblastic maturation. Indeed, MC3T3-E1 cells exposed to the powdered cements had increased proliferative rates and higher adhesiveness capacity, in comparison to control cells. Furthermore, they exhibited higher alkaline phosphatase (ALP) activity and increased Type-I collagen secretion and fibre deposition into the extracellular matrix. Proliferative and collagen deposition properties were more evident for cells grown in cements doped with Sr. The in vivo osteoconductive propertiesof the ZnCPC and ZnSrCPC cements were also pursued. Histological and histomorphometric analyses were performed at 1 and 2 months after implantation, using carbonated apatite cement (Norian SRS) as control. There was no evidence of cement-induced adverse foreign body reactions, and furthermore ZnCPC and ZnSrCPC cements revealed better in vivo performance in comparison to the control apatite cement. Additionally, the presence of both zinc and strontium resulted in the highest rate of new bone formation. These novel results indicate that the investigated ZnCPC and ZnSrCPC cements are both biocompatible and osteoconductive, being good candidate materials to use as bone substitutes. PMID:20821372

  19. The promotion of angiogenesis induced by three-dimensional porous beta-tricalcium phosphate scaffold with different interconnection sizes via activation of PI3K/Akt pathways

    PubMed Central

    Xiao, Xin; Wang, Wei; Liu, Dong; Zhang, Haoqiang; Gao, Peng; Geng, Lei; Yuan, Yulin; Lu, Jianxi; Wang, Zhen

    2015-01-01

    The porous architectural characteristics of biomaterials play an important role in scaffold revascularization. However, no consensus exists regarding optimal interconnection sizes for vascularization and its scaffold bioperformance with different interconnection sizes. Therefore, a series of disk-type beta-tricalcium phosphates with the same pore sizes and variable interconnections were produced to evaluate how the interconnection size influenced biomaterial vascularization in vitro and in vivo. We incubated human umbilical vein endothelial cells on scaffolds with interconnections of various sizes. Results showed that scaffolds with a 150 μm interconnection size ameliorated endothelial cell function evidenced by promoting cell adhesion and migration, increasing cell proliferation and enhancing expression of platelet-endothelial cell adhesion molecules and vascular endothelial growth factor. In vivo study was performed on rabbit implanted with scaffolds into the bone defect on femoral condyles. Implantation with scaffolds with 150 μm interconnection size significantly improved neovascularization as shown by micro-CT as compared to scaffolds with 100 and 120 μm interconnection sizes. Moreover, the aforementioned positive effects were abolished by blocking PI3K/Akt/eNOS pathway with LY-294002. Our study explicitly demonstrates that the scaffold with 150 μm interconnection size improves neovascularization via the PI3K/Akt pathway and provides a target for biomaterial inner structure modification to attain improved clinical performance in implant vascularization. PMID:25797242

  20. The promotion of angiogenesis induced by three-dimensional porous beta-tricalcium phosphate scaffold with different interconnection sizes via activation of PI3K/Akt pathways

    NASA Astrophysics Data System (ADS)

    Xiao, Xin; Wang, Wei; Liu, Dong; Zhang, Haoqiang; Gao, Peng; Geng, Lei; Yuan, Yulin; Lu, Jianxi; Wang, Zhen

    2015-03-01

    The porous architectural characteristics of biomaterials play an important role in scaffold revascularization. However, no consensus exists regarding optimal interconnection sizes for vascularization and its scaffold bioperformance with different interconnection sizes. Therefore, a series of disk-type beta-tricalcium phosphates with the same pore sizes and variable interconnections were produced to evaluate how the interconnection size influenced biomaterial vascularization in vitro and in vivo. We incubated human umbilical vein endothelial cells on scaffolds with interconnections of various sizes. Results showed that scaffolds with a 150 μm interconnection size ameliorated endothelial cell function evidenced by promoting cell adhesion and migration, increasing cell proliferation and enhancing expression of platelet-endothelial cell adhesion molecules and vascular endothelial growth factor. In vivo study was performed on rabbit implanted with scaffolds into the bone defect on femoral condyles. Implantation with scaffolds with 150 μm interconnection size significantly improved neovascularization as shown by micro-CT as compared to scaffolds with 100 and 120 μm interconnection sizes. Moreover, the aforementioned positive effects were abolished by blocking PI3K/Akt/eNOS pathway with LY-294002. Our study explicitly demonstrates that the scaffold with 150 μm interconnection size improves neovascularization via the PI3K/Akt pathway and provides a target for biomaterial inner structure modification to attain improved clinical performance in implant vascularization.

  1. A Comparison of the Process of Remodeling of Hydroxyapatite/Poly-D/L-Lactide and Beta-Tricalcium Phosphate in a Loading Site

    PubMed Central

    Akagi, Hiroyuki; Ochi, Hiroki; Soeta, Satoshi; Kanno, Nobuo; Yoshihara, Megumi; Okazaki, Kenshi; Yogo, Takuya; Harada, Yasuji; Amasaki, Hajime; Hara, Yasushi

    2015-01-01

    Currently, the most commonly used bioresorbable scaffold is made of beta-tricalcium phosphate (β-TCP); it is hoped that scaffolds made of a mixture of hydroxyapatite (HA) and poly-D/L-lactide (PDLLA) will be able to act as novel bioresorbable scaffolds. The aim of this study was to evaluate the utility of a HA/PDLLA scaffold compared to β-TCP, at a loading site. Dogs underwent surgery to replace a section of tibial bone with a bioresorbable scaffold. After the follow-up period, the scaffold was subjected to histological analysis. The HA/PDLLA scaffold showed similar bone formation and superior cell and tissue infiltration compared to the β-TCP scaffold, as seen after Villanueva Goldner staining. Moreover, silver staining and immunohistochemistry for Von Willebrand factor and cathepsin K demonstrated better cell infiltration in the HA/PDLLA scaffold. The fibrous tissue and cells that had infiltrated into the HA/PDLLA scaffold tested positive for collagen type I and RUNX2, respectively, indicating that the tissue and cells that had infiltrated into the HA/PDLLA scaffold had the potential to differentiate into bone. The HA/PDLLA scaffold is therefore likely to find clinical application as a new bioresorbable scaffold. PMID:26504825

  2. Combined treatment with parathyroid hormone (1-34) and beta-tricalcium phosphate had an additive effect on local bone formation in a rat defect model.

    PubMed

    Tao, Zhou-Shan; Tu, Kai-Kai; Huang, Zheng-Liang; Zhou, Qiang; Sun, Tao; Xu, Hong-Ming; Zhou, Yu-Long; Lv, Yang-Xun; Cui, Wei; Yang, Lei

    2016-09-01

    The objective of this study was to evaluate the effect of following combined treatment with parathyroid hormone (1-34) (PTH) and beta-tricalcium phosphate (β-TCP) on local bone formation in a rat 3-mm critical-size defect at distal femur. Twelve weeks after bilateral ovariectomy (OVX) and sham operation (sham), all animals were randomly divided into four groups: group OVX, group OVX + β-TCP, group sham, and group sham + β-TCP, then all rats underwent bone defect in the bilateral distal femurs, and β-TCP were implanted into critical-sized defects for group OVX + β-TCP and group sham + β-TCP. After defect operation, all animals were received following subcutaneous injections with PTH (60 μg/kg, three times a week) until death at 4 and 8 weeks. The defected area in distal femurs of rats was harvested for evaluation by histology, micro-CT, and biomechanics. The results of our study show that systemic usage of PTH or local usage of β-TCP can increase the healing of defects in OVX or sham rats. Furthermore, treatments with PTH and β-TCP showed a stronger effect on accelerating the local bone formation than used alone. Osteoporosis can limit the function of PTH and/or β-TCP. The results from our study demonstrate that combination of PTH and β-TCP had an additive effect on local bone formation in non-osteoporosis and/or osteoporosis rats. PMID:26429350

  3. Effects of concomitant use of fibroblast growth factor (FGF)-2 with beta-tricalcium phosphate ({beta}-TCP) on the beagle dog 1-wall periodontal defect model

    SciTech Connect

    Anzai, Jun; Kitamura, Masahiro; Nozaki, Takenori; Nagayasu, Toshie; Terashima, Akio; Asano, Taiji; Murakami, Shinya

    2010-12-17

    Research highlights: {yields} Concomitant use of FGF-2 and {beta}-TCP (an osteo-conductive scaffold) significantly promotes periodontal regeneration in the severe periodontitis model (1-wall defect model) of beagle dog. {yields} FGF-2 enhanced new bone formation via {beta}-TCP at the defects. {yields} In particular, FGF-2 dramatically regenerated new periodontal ligament and cementum formations at the defects, that is one of the most important healing outcomes during the process of periodontal regeneration. {yields} Epithelial downgrowth (undesirable wound healing) was decreased by administration of FGF-2. {yields} This manuscript indicates for the first time that concomitant use of FGF-2 and {beta}-TCP is efficacious in regenerating periodontal tissue following severe destruction of the tissue by progression of periodontitis. -- Abstract: The effects of concomitant use of fibroblast growth factor-2 (FGF-2) and beta-tricalcium phosphate ({beta}-TCP) on periodontal regeneration were investigated in the beagle dog 1-wall periodontal defect model. One-wall periodontal defects were created in the mesial portion of both sides of the mandibular first molars, and 0.3% FGF-2 plus {beta}-TCP or {beta}-TCP alone was administered. Radiographic evaluation was performed at 0, 3, and 6 weeks. At 6 weeks, the periodontium with the defect site was removed and histologically analyzed. Radiographic findings showed that co-administration of FGF-2 significantly increased bone mineral contents of the defect sites compared with {beta}-TCP alone. Histologic analysis revealed that the length of the regenerated periodontal ligament, the cementum, distance to the junctional epithelium, new bone height, and area of newly formed bone were significantly increased in the FGF-2 group. No abnormal inflammatory response or ankylosis was observed in either group. These findings indicate the efficacy of concomitant use of FGF-2 and {beta}-TCP as an osteoconductive material for periodontal

  4. Comparative study of biphasic calcium phosphate with beta-tricalcium phosphate in rat cranial defects--A molecular-biological and histological study.

    PubMed

    Kunert-Keil, Christiane; Scholz, Franziska; Gedrange, Tomasz; Gredes, Tomasz

    2015-05-01

    The aim of this study was to evaluate the in vivo biocompatibility of a biphasic calcium phosphate (BCP) bone graft substitute consisting of 60% hydroxyapatite and 40% β-tricalcium phosphate (β-TCP) in comparison to a pure β-TCP of identical shape and porosity. The materials were evaluated using an established rat cranial defect model in 24 animals. One bone defect with a diameter of 5mm was created per animal. The defects were filled with either BCP or β-TCP and left to heal for 4 weeks. Twelve samples (6 per material) were processed for histological evaluation and immunohistochemistry. The remaining 12 samples were processed for mRNA expression analysis. No signs of inflammation or adverse material reactions were detected. New bone formation in the former defect site did not differ between the two groups (BCP: 49.2%; β-TCP: 52.4%). Osteoblast-like and TRAP-positive osteoclast-like cells were found at the surface of the bone graft substitute granules. The β-TCP group showed significantly higher mRNA levels for the bone resorption marker Acp5 and osteogenic differentiation marker Runx2. The expression of IGF1, IGF2, VEGF, Phex, Alpl, Col1, Col2, Bglap and MMP8 did not differ between the groups. The in vivo biocompatibility of BCP is to a large part identical to those of TCP. Within the limitation of the animal model, the implantation study shows that BCP can be used as bone graft substitute, due to the fact that the material integrates into tissue, remains stable in the implantation bed and serves as an osteoconductive scaffold. PMID:24439994

  5. Beta-tricalcium phosphate granules improve osteogenesis in vitro and establish innovative osteo-regenerators for bone tissue engineering in vivo

    PubMed Central

    Gao, Peng; Zhang, Haoqiang; Liu, Yun; Fan, Bo; Li, Xiaokang; Xiao, Xin; Lan, Pingheng; Li, Minghui; Geng, Lei; Liu, Dong; Yuan, Yulin; Lian, Qin; Lu, Jianxi; Guo, Zheng; Wang, Zhen

    2016-01-01

    The drawbacks of traditional bone-defect treatments have prompted the exploration of bone tissue engineering. This study aimed to explore suitable β-tricalcium phosphate (β-TCP) granules for bone regeneration and identify an efficient method to establish β-TCP-based osteo-regenerators. β-TCP granules with diameters of 1 mm and 1–2.5 mm were evaluated in vitro. The β-TCP granules with superior osteogenic properties were used to establish in vivo bioreactors, referred to as osteo-regenerators, which were fabricated using two different methods. Improved proliferation of bone mesenchymal stem cells (BMSCs), glucose consumption and ALP activity were observed for 1–2.5 mm β-TCP compared with 1-mm granules (P < 0.05). In addition, BMSCs incubated with 1–2.5 mm β-TCP expressed significantly higher levels of the genes for runt-related transcription factor-2, alkaline phosphatase, osteocalcin, osteopontin, and collagen type-1 and the osteogenesis-related proteins alkaline phosphatase, collagen type-1 and runt-related transcription factor-2 compared with BMSCs incubated with 1 mm β-TCP (P < 0.05). Fluorochrome labelling, micro-computed tomography and histological staining analyses indicated that the osteo-regenerator with two holes perforating the femur promoted significantly greater bone regeneration compared with the osteo-regenerator with a periosteum incision (P < 0.05). This study provides an alternative to biofunctionalized bioreactors that exhibits improved osteogenesis. PMID:27000963

  6. A minimum 2-year comparative study of autologous cancellous bone grafting versus beta-tricalcium phosphate in anterior cervical discectomy and fusion using a rectangular titanium stand-alone cage.

    PubMed

    Yamagata, Toru; Naito, Kentaro; Arima, Hironori; Yoshimura, Masaki; Ohata, Kenji; Takami, Toshihiro

    2016-07-01

    Although titanium stand-alone cages are commonly used in anterior cervical discectomy and fusion (ACDF), there are several concerns such as cage subsidence after surgery. The efficacy of β-tricalcium phosphate (β-TCP) granules as a packing material in 1- or 2-level ACDF using a rectangular titanium stand-alone cage is not fully understood. The purpose of this study is to investigate the validity of rectangular titanium stand-alone cages in 1- and 2-level ACDF with β-TCP. This retrospective study included 55 consecutive patients who underwent ACDF with autologous iliac cancellous bone grafting and 45 consecutive patients with β-TCP grafting. All patients completed at least 2-year postoperative follow-up. Univariate and multivariate analyses were performed to examine the associations between study variables and nonunion after surgery. Significant neurological recovery after surgery was obtained in both groups. Cage subsidence was noted in 14 of 72 cages (19.4 %) in the autograft group and 12 of 64 cages (18.8 %) in the β-TCP group. A total of 66 cages (91.7 %) in the autograft group showed osseous or partial union, and 58 cages (90.6 %) in the β-TCP group showed osseous or partial union by 2 years after surgery. There were no significant differences in cage subsidence and the bony fusion rate between the two groups. Multivariate analysis using a logistic regression model showed that fusion level at C6/7, 2-level fusion, and cage subsidence of grades 2-3 were significantly associated with nonunion at 2 years after surgery. Although an acceptable surgical outcome with negligible complication appears to justify the use of rectangular titanium stand-alone cages in 1- and 2-level ACDF with β-TCP, cage subsidence after surgery needs to be avoided to achieve acceptable bony fusion at the fused segments. Fusion level at C6/7 or 2-level fusion may be another risk factor of nonunion. PMID:27098659

  7. Evaluation of Dense Polylactic Acid/Beta-Tricalcium Phosphate Scaffolds for Bone Tissue Engineering

    PubMed Central

    Yanoso-Scholl, Laura; Jacobson, Justin A.; Bradica, Gino; Lerner, Amy L.; O’Keefe, Regis J.; Schwarz, Edward M.; Zuscik, Michael J.; Awad, Hani A.

    2010-01-01

    Advances in biomaterial fabrication have introduced numerous innovations in designing scaffolds for bone tissue engineering. Often, the focus has been on fabricating scaffolds with high and interconnected porosity that would allow for cellular seeding and tissue ingrowth. However, such scaffolds typically lack the mechanical strength to sustain in vivo ambulatory stresses in models of load bearing cortical bone reconstruction. In this study, we investigated the microstructural and mechanical properties of dense PLA and PLA/beta-TCP (85:15) scaffolds fabricated using a rapid volume expansion phase separation technique, which embeds uncoated beta-TCP particles within the porous polymer. PLA scaffolds had a volumetric porosity in the range of 30 – 40%. With the embedding of beta-TCP mineral particles, the porosity of the scaffolds was reduced in half while the ultimate compressive and torsional strength were significantly increased. We also investigated the properties of the scaffolds as delivery vehicles for growth factors and gene delivery vectors in vitro and in vivo. The low surface porosity resulted in sub optimal retention efficiency of the growth factors, and burst release kinetics reflecting surface coating rather than volumetric entrapment, regardless of the scaffold used. When loaded with BMP2 and VEGF and implanted in the quadriceps muscle, PLA/beta-TCP scaffolds did not induce ectopic mineralization but induced a significant 1.8 fold increase in neo vessel formation. In conclusion, dense PLA/beta-TCP scaffolds can be engineered with enhanced mechanical properties and potentially be exploited for localized therapeutic factor delivery. PMID:20725979

  8. In vitro tobramycin elution analysis from a novel beta-tricalcium phosphate-silicate-xerogel biodegradable drug-delivery system.

    PubMed

    DiCicco, Michael; Goldfinger, Aaron; Guirand, Felix; Abdullah, Aquill; Jansen, Susan A

    2004-07-15

    This in vitro research analyzed local tobramycin elution characteristics from a novel, biodegradable drug delivery system, consisting of a beta-TCP bone substitute, VITOSS trade mark, encapsulated with silicate xerogel prepared by the sol-gel process. Tobramycin elution from silicate-xerogel-encapsulated VITOSS was compared directly with non-silicate-xerogel-encapsulated VITOSS to assess whether xerogels are effective in delivering greater tobramycin quantities in a controllable, sustained manner crucial for microbial inhibition. Tobramycin elution characteristics indicate an initial release maximum during the first 24 h that diminishes gradually several days after impregnation. The copious tobramycin quantity eluted from the VITOSS/silicate-xerogel systems is attributed to various factors: the intrinsic ultraporosity and hydrophilicity of VITOSS, the ability of tobramycin to completely dissolve in aqueous media, tobramycin complexation with highly polar SO(4) (2-) salts that further assist dissolution, and ionic exchanges between VITOSS and the environment. Silicate-xerogel-encapsulated VITOSS eluted 60.65 and 61.31% of impregnated tobramycin, whereas non-silicate-xerogel-encapsulated VITOSS eluted approximately one-third less impregnated tobramycin, at 21.53 and 23.60%. These results suggest that silicate xerogel optimizes tobramycin elution because of its apparent biodegradability. This mechanism occurs through xerogel superficial acidic sites undergoing exchanges with various ions present in the leaching buffer. Tobramycin elution kinetics were evaluated, and demonstrate that first-order elution rate constants are considerably less when silicate xerogels are employed, following a more uniform exponential decay-type mechanism, thus bolstering controlled release. Overall, tobramycin elution rates adhere to linear-type Higuchi release profiles. Elution rate constants are initially first order, and taper into zero-order elution kinetics in the latter stages of release. Because VITOSS and silicate xerogel are completely biodegradable, essentially all impregnated tobramycin will be delivered to the surgical site after implantation. PMID:15199578

  9. Interaction between hydroxypropyl methylcellulose and biphasic calcium phosphate after steam sterilisation: capillary gas chromatography studies.

    PubMed

    Bourges, X; Schmitt, M; Amouriq, Y; Daculsi, G; Legeay, G; Weiss, P

    2001-01-01

    The purpose of this study was to check the chemical stability of an injectable bone substitute (IBS) composed of a 50/50 w/w mixture of 2.92% hydroxypropyl methylcellulose (HPMC) solution in deionized water containing biphasic calcium phosphate (BCP) granules (60% hydroxyapatite/40% beta-tricalcium phosphate w/w). After separation of the organic and mineral phases, capillary gas chromatography (GC) was used to study the possible modification of HPMC due to the contact with BCP granules following steam sterilisation and 32 days storage at room temperature. HPMC was extracted from IBS in aqueous medium, and a dialytic method was then used to extract calcium phosphate salts from the HPMC. The percentage of HPMC extracted from BCP was 98.5%+/-0.5%, as measured by UV. GC showed no chemical modifications after steam sterilisation and storage. PMID:11556737

  10. Tethering of Epidermal Growth Factor (EGF) to Beta Tricalcium Phosphate (βTCP) via Fusion to a High Affinity, Multimeric βTCP-Binding Peptide: Effects on Human Multipotent Stromal Cells/Connective Tissue Progenitors

    PubMed Central

    Stockdale, Linda; Saini, Sunil; Lee, Richard T.; Griffith, Linda G.

    2015-01-01

    Transplantation of freshly-aspirated autologous bone marrow, together with a scaffold, is a promising clinical alternative to harvest and transplantation of autologous bone for treatment of large defects. However, survival proliferation, and osteogenic differentiation of the marrow-resident stem and progenitor cells with osteogenic potential can be limited in large defects by the inflammatory microenvironment. Previous studies using EGF tethered to synthetic polymer substrates have demonstrated that surface-tethered EGF can protect human bone marrow-derived osteogenic stem and progenitor cells from pro-death inflammatory cues and enhance their proliferation without detriment to subsequent osteogenic differentiation. The objective of this study was to identify a facile means of tethering EGF to clinically-relevant βTCP scaffolds and to demonstrate the bioactivity of EGF tethered to βTCP using stimulation of the proliferative response of human bone-marrow derived mesenchymal stem cells (hBMSC) as a phenotypic metric. We used a phage display library and panned against βTCP and composites of βTCP with a degradable polyester biomaterial, together with orthogonal blocking schemes, to identify a 12-amino acid consensus binding peptide sequence, LLADTTHHRPWT, with high affinity for βTCP. When a single copy of this βTCP-binding peptide sequence was fused to EGF via a flexible peptide tether domain and expressed recombinantly in E. coli together with a maltose-binding domain to aid purification, the resulting fusion protein exhibited modest affinity for βTCP. However, a fusion protein containing a linear concatamer containing 10 repeats of the binding motif the resulting fusion protein showed high affinity stable binding to βTCP, with only 25% of the protein released after 7 days at 37oC. The fusion protein was bioactive, as assessed by its abilities to activate kinase signaling pathways downstream of the EGF receptor when presented in soluble form, and to enhance the proliferation of hBMSC when presented in tethered form on commercial βTCP bone regeneration scaffolds. PMID:26121597

  11. Bacterial biosynthesis of a calcium phosphate bone-substitute material.

    PubMed

    Thackray, Aniac C; Sammons, Rachel L; Macaskie, Lynne E; Yong, Ping; Lugg, Harriet; Marquis, Peter M

    2004-04-01

    A species of Serratia bacteria produces nano-crystalline hydroxyapatite (HA) crystals by use of a cell-bound phosphatase enzyme, located both periplasmically and within extracellular polymeric materials. The enzyme functions in resting cells by cleaving glycerol-2-phosphate (G-2-P) to liberate free phosphate ions which combine with calcium in solution to produce a cell-bound calcium phosphate material. Bacteria grown as a biofilm on polyurethane reticulated foam cubes were challenged with calcium and G-2-P in a bioreactor to produce a 3-D porous bone-substitute material. The scaffold has 1 mm macropores and 1 microm micropores. XRD showed the crystallites to be 25-28 nm in size, resembling HA before sintering and beta-tricalcium phosphate (beta-TCP, whitlockite) after. When biofilm was grown on titanium discs and challenged with calcium and G-2-P, a calcium phosphate layer formed on the discs. Biomineralisation is therefore a potential route to production of precursor nanophase HA, which has the potential to improve strength. The scaffold material produced by this method could be used as a bone-filler or as an alternative method for coating implants with a layer of HA. PMID:15332607

  12. Bone Regeneration of Rat Tibial Defect by Zinc-Tricalcium Phosphate (Zn-TCP) Synthesized from Porous Foraminifera Carbonate Macrospheres

    PubMed Central

    Chou, Joshua; Hao, Jia; Kuroda, Shinji; Bishop, David; Ben-Nissan, Besim; Milthorpe, Bruce; Otsuka, Makoto

    2013-01-01

    Foraminifera carbonate exoskeleton was hydrothermally converted to biocompatible and biodegradable zinc-tricalcium phosphate (Zn-TCP) as an alternative biomimetic material for bone fracture repair. Zn-TCP samples implanted in a rat tibial defect model for eight weeks were compared with unfilled defect and beta-tricalcium phosphate showing accelerated bone regeneration compared with the control groups, with statistically significant bone mineral density and bone mineral content growth. CT images of the defect showed restoration of cancellous bone in Zn-TCP and only minimal growth in control group. Histological slices reveal bone in-growth within the pores and porous chamber of the material detailing good bone-material integration with the presence of blood vessels. These results exhibit the future potential of biomimetic Zn-TCP as bone grafts for bone fracture repair. PMID:24351911

  13. Premixed acidic calcium phosphate cement: characterization of strength and microstructure.

    PubMed

    Aberg, J; Brisby, H; Henriksson, H B; Lindahl, A; Thomsen, P; Engqvist, H

    2010-05-01

    By using a premixed calcium phosphate cement (CPC), the handling properties of the cement are drastically improved, which is a challenge for traditional injectable CPCs. Previously premixed cements have been based on apatitic cements. In this article, acidic cement has been developed and evaluated. Monocalcium phosphate monohydrate and beta-tricalcium phosphate were mixed with glycerol to form a paste. As the paste does not contain water, no setting reaction starts and thus the working time is indefinite. Powder/liquid ratios (P/L) of 2.25, 3.5 and 4.75 were evaluated. Setting time (ST) and compressive strength (CS) were measured after 1 day, 1 week and 4 weeks in phosphate buffered saline (PBS) solution, and the corresponding microstructure was evaluated using electron microscopy and X-ray diffraction. The ST started when the cements were placed in PBS and ranged from 28 to 75 min, higher P/L gave a lower ST. Higher P/L also gave a higher CS, which ranged from 2 to 16 MPa. The microstructure mainly consisted of monetite, 1-5 microm in grain size. After 4 weeks in PBS, the strength increased. As acidic cements are resorbed faster in vivo, this cement should allow faster bone regeneration than apatitic cements. Premixed cements show a great handling benefit when compared with normal CPCs and can be formulated with similar ST and mechanical properties. PMID:20127991

  14. Factors influencing calcium phosphate cement shelf-life.

    PubMed

    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. PMID:15621259

  15. beta-TCP/MCPM-based premixed calcium phosphate cements.

    PubMed

    Han, Bing; Ma, Peng-Wei; Zhang, Li-Li; Yin, Yu-Ji; Yao, Kang-De; Zhang, Fu-Jiang; Zhang, Yong-Dong; Li, Xiu-Lan; Nie, Wei

    2009-10-01

    Novel premixed calcium phosphate cements (CPCs) were prepared by combining cement liquids comprised of glycerol or polyethylene glycol with CPC powders that consisted of beta-tricalcium phosphate (beta-TCP) and monocalcium phosphate monohydrate (MCPM). Changing the powder to liquid mass ratio enabled the setting time to be regulated, and improved the compressive strength of the CPCs. Although some ratios of the new premixed CPCs had long setting times, these ranged from 12.4 to 27.8 min which is much shorter than the hour or more reported previously for a premixed CPC. The premixed CPCs had tolerable washout resistance before final setting, and the cements had strengths matching that of cancellous bone (5-10 MPa); their maximum compressive strength was up to 12 MPa. The inflammatory response around the premixed CPCs implanted in the subcutaneous tissue in rabbits was more prominent than that of apatite cement. These differences might be due to the much faster resorption rate of the premixed CPCs. PMID:19427931

  16. In vitro evaluation of a new injectable calcium phosphate material.

    PubMed

    Grimandi, G; Weiss, P; Millot, F; Daculsi, G

    1998-03-15

    The purpose of this study was to develop an injectable bone substitute (IBS) for percutaneous orthopedic surgery. The multiphasic material used was composed of a 2% aqueous solution of methylhydroxypropylcellulose (MHPC) and biphasic calcium phosphate (BCP, 60% hydroxyapatite and 40% beta-tricalcium phosphate) in which MHPC served as the carrier for 80-200 microm of BCP granules. The best BCP/polymer ratio was determined by the rheological properties and higher BCP content of the material. Steam sterilization was more effective than gamma irradiation in maintaining the stability of the mixture and conserving its physiochemical and mechanical properties. The in vitro biocompatibility of the composite was checked by direct-contact cytotoxicity and cell-proliferation assays. A preliminary in vivo test was performed in the rabbit using intraosseous implantations in the femoral epiphysis. Histological analysis was done after 1, 2, 4, and 10 weeks. Bone ingrowth into the IBS, in close association with BCP granules, was observed after 1 week and increased regularly from the surface inward at 2, 4, and 10 weeks. At the same time, smaller BCP granules (less than 80 microns in diameter) were degraded and resorbed. This injectable biomaterial proved suitable for cavity filling. The water solubility and viscosity of the polymer allow cells to recolonize, with in situ bonding of the mineral phase. PMID:9492229

  17. Analytical and mechanical testing of high velocity oxy-fuel thermal sprayed and plasma sprayed calcium phosphate coatings.

    PubMed

    Haman, J D; Chittur, K K; Crawmer, D E; Lucas, L C

    1999-01-01

    Plasma spraying (PS) is the most frequently used coating technique for implants; however, in other industries a cheaper, more efficient process, high-velocity oxy-fuel thermal spraying (HVOF), is in use. This process provides higher purity, denser, more adherent coatings than plasma spraying. The primary objective of this work was to determine if the use of HVOF could improve the mechanical properties of calcium phosphate coatings. Previous studies have shown that HVOF calcium phosphate coatings are more crystalline than plasma sprayed coatings. In addition, because the coatings are exposed to more complex loading profiles in vivo than standard ASTM tensile tests provide, a secondary objective of this study was to determine the applicability of four-point bend testing for these coatings. Coatings produced by HVOF and PS were analyzed by profilometry, diffuse reflectance Fourier transform infrared spectroscopy, X-ray diffraction, four-point bend, and ASTM C633 tensile testing. HVOF coatings were found to have lower amorphous calcium phosphate content, higher roughness values, and lower ASTM C633 bond strengths than PS coatings; however, both coatings had similar crystal unit cell sizes, phases present (including hydroxyapatite, beta-tricalcium phosphate, and tetracalcium phosphate), and four-point bend bond strengths. Thus, the chemical, structural, and mechanical results of this study, in general, indicate that the use of HVOF to produce calcium phosphate coatings is equivalent to those produced by plasma spraying. PMID:10556851

  18. Reinforcement of freeze-dried chitosan scaffolds with multiphasic calcium phosphate short fibers.

    PubMed

    Mohammadi, Zahra; Mesgar, Abdorreza Sheikh-Mehdi; Rasouli-Disfani, Fariba

    2016-08-01

    The composite scaffolds of the chitosan and multiphasic calcium phosphate (HW) short fibers were prepared by freeze drying and characterized by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM and FE-SEM). The mechanical properties of the scaffolds were assessed by compression test. The incorporation of HW fibers consisting three phases of hydroxyapatite (HA), beta-tricalcium phosphate (β-TCP) and calcium pyrophosphate (CPP) into the chitosan matrices was associated with an increase in pore size, density and compressive strength and modulus, and a decrease in porosity and swelling ratio of the scaffolds. The strongest composite scaffolds in this study with a chitosan: HW fibers weight ratio of 1:1 showed a mean porosity of 69% and a mean strength and modulus of 420kPa and 3.87MPa, respectively. The in vitro bioactivity of the composites was confirmed by the formation of a calcium phosphate rich layer on the surface of soaked scaffolds in simulated body fluid. The findings of this initial work indicate that the chitosan-multiphasic calcium phosphate short fibers may be a suitable material for bone scaffolding. PMID:27179144

  19. Loading and release of doxycycline hyclate from strontium-substituted calcium phosphate cement.

    PubMed

    Alkhraisat, M Hamdan; Rueda, C; Cabrejos-Azama, J; Lucas-Aparicio, J; Mariño, F Tamimi; Torres García-Denche, J; Jerez, L Blanco; Gbureck, U; Cabarcos, E Lopez

    2010-04-01

    Novel Sr-substituted calcium phosphate cement (CPC) loaded with doxycycline hyclate (DOXY-h) was employed to elucidate the effect of strontium substitution on antibiotic delivery. The cement was prepared using as reactants Sr-substituted beta-tricalcium phosphate (Sr-beta-TCP) and acidic monocalcium phosphate monohydrate. Two different methods were used to load DOXY-h: (i) the adsorption on CPC by incubating the set cement in drug-containing solutions; and (ii) the use of antibiotic solution as the cement liquid phase. The results revealed that the Sr-substituted cement efficiently adsorbs the antibiotic, which is attributed to an enhanced accessibility to the drug-binding sites within this CPC. DOXY-h desorption is influenced by the initial adsorbed amount and the cement matrix type. Furthermore, the fraction of drug released from CPCs set with DOXY-h solution was higher, and the release rate was faster for the CPC prepared with 26.7% Sr-beta-TCP. The analysis of releasing profiles points to Fickian diffusion as the mechanism responsible for antibiotic delivery. We can conclude that Sr substitution in secondary calcium phosphate cements improves their efficiency for DOXY-h adsorption and release. The antibiotic loading method provides a way to switch from rapid and complete to slower and prolonged drug release. PMID:19879982

  20. Reactive calcium-phosphate-containing poly(ester-co-ether) methacrylate bone adhesives: chemical, mechanical and biological considerations.

    PubMed

    Zhao, Xin; Olsen, Irwin; Li, Haoying; Gellynck, Kris; Buxton, Paul G; Knowles, Jonathan C; Salih, Vehid; Young, Anne M

    2010-03-01

    A poly(propylene glycol-co-lactide) dimethacrylate adhesive with monocalcium phosphate monohydrate (MCPM)/beta-tricalcium phosphate (beta-TCP) fillers in various levels has been investigated. Water sorption by the photo-polymerized materials catalyzed varying filler conversion to dicalcium phosphate (DCP). Polymer modulus was found to be enhanced upon raising total calcium phosphate content. With greater DCP levels, faster release of phosphate and calcium ions and improved buffering of polymer degradation products were observed. This could reduce the likelihood of pH-catalyzed bulk degradation and localized acid production and thereby may prevent adverse biological responses. Bone-like MG-63 cells were found to attach, spread and have normal morphology on both the polymer and composite surfaces. Moreover, composites implanted into chick embryo femurs became closely apposed to the host tissue and did not appear to induce adverse immunological reaction. The above results suggest that the new composite materials hold promise as clinical effective bone adhesives. PMID:19800424

  1. Characterization of dicalcium phosphate dihydrate cements prepared using a novel hydroxyapatite-based formulation.

    PubMed

    Alge, Daniel L; Santa Cruz, Grace; Goebel, W Scott; Chu, Tien-Min Gabriel

    2009-04-01

    Dicalcium phosphate dihydrate (DCPD) cements are typically prepared using beta-tricalcium phosphate (beta-TCP) as the base component. However, hydroxyapatite (HA) is an interesting alternative because of its potential for reducing cement acidity, as well as modulating cement properties via ionic substitutions. In the present study, we have characterized DCPD cements prepared with a novel formulation based on monocalcium phosphate monohydrate (MCPM) and HA. Cements were prepared using a 4:1 MCPM:HA molar ratio. The reactivity of HA in this system was verified by showing DCPD formation using poorly crystalline HA, as well as highly crystalline HA. Evaluation of cements prepared with poorly crystalline HA revealed that setting occurs rapidly in the MCPM/HA system, and that the use of a setting regulator is necessary to maintain workability of the cement paste. Compressive testing showed that MCPM/HA cements have strengths comparable to what has previously been published for DCPD cements. However, preliminary in vitro analysis of cement degradation revealed that conversion of DCPD to HA may occur much more rapidly in the MCPM/HA system compared to cements prepared with beta-TCP. Future studies should investigate this property further, as it could have important implications for the use of HA-based DCPD cement formulations. PMID:19349655

  2. In vitro elution of vancomycin from biodegradable osteoconductive calcium phosphate-polycaprolactone composite beads for treatment of osteomyelitis.

    PubMed

    Makarov, C; Cohen, V; Raz-Pasteur, A; Gotman, I

    2014-10-01

    In this work, osteoconductive composite materials comprising a large volume fraction of a bioresorbable calcium phosphate ceramic (CaP) and a smaller amount of a polycaprolactone polymer (PCL) were studied as a degradable antibiotic carrier material for treatment of osteomyelitis. Beads loaded with 1 and 4wt.% vancomycin were prepared by admixing dissolved drug to an in situ synthesized dicalcium phosphate (DCP)-PCL or solution-mixed beta-tricalcium phosphate (βTCP)-PCL composite powder followed by high pressure consolidation of the blend at room temperature. Vancomycin release was measured in phosphate-buffered saline (PBS) at 37°C. All the beads gradually released the drug over the period of 4-11weeks, depending on the composite matrix homogeneity and porosity. Mathematical modeling using the Peppas equation showed that vancomycin elution was diffusion controlled. The stability of the antibiotic after high pressure application at room temperature was demonstrated by high-performance liquid chromatography-mass spectrometry (HPLC-MS) studies and MIC testing. The preservation of the structure and activity of vancomycin during the processing of composite beads and its sustained in vitro release profile suggest that high pressure consolidated CaP-PCL beads may be useful in the treatment of chronic bone infections as resorbable delivery vehicles of vancomycin and even of thermally unstable drug substances. PMID:24859314

  3. Ionic modification of calcium phosphate cement viscosity. Part II: hypodermic injection and strength improvement of brushite cement.

    PubMed

    Barralet, J E; Grover, L M; Gbureck, U

    2004-05-01

    Brushite-forming calcium phosphate cements are of great interest as bone replacement materials because they are resorbable in physiological conditions. However, their short setting times, low mechanical strengths and limited injectability limit broad clinical application. In this study, we showed that a significant improvement of these properties of brushite cement could be achieved by the use of sodium citrate or citric acid as setting retardants, such that workable cement pastes with a powder to liquid ratio of up to 5 could be manufactured. The cement used in this study consisted of an equimolar powder mixture of beta-tricalcium phosphate and monocalcium phosphate hydrate The use of 500 mM-1M retardant solutions as liquid phase enabled initial setting times of 8-12 min. Wet compressive strength were found to be in the range between 12-18 MPa after immersion of uncompacted cement samples in serum for 24 h. A further strength improvement to 32 MPa was obtained by compaction of the cement paste during samples preparation. This is significant because high-temperature processes cannot be used to fabricate hydrated calcium phosphate materials. Cement pastes were injectable through a hypodermic needle at a powder to liquid ratio of 3.3 g/ml when a 1M citric acid was used as liquid phase, thus enabling precise controlled delivery to small defects. PMID:14741635

  4. Cytocompatibility of porous biphasic calcium phosphate granules with human mesenchymal cells by a multiparametric assay.

    PubMed

    Mitri, Fabio; Alves, Gutemberg; Fernandes, Gustavo; König, Bruno; Rossi, Alexandre J R; Granjeiro, Jose

    2012-06-01

    This work aims to evaluate the cytocompatibility of injectable and moldable restorative biomaterials based on granules of dense or porous biphasic calcium phosphates (BCPs) with human primary mesenchymal cells, in order to validate them as tools for stem cell-induced bone regeneration. Porous hydroxyapatite (HA) and HA/beta-tricalcium phosphate (β-TCP) (60:40) granules were obtained by the addition of wax spheres and pressing at 20 MPa, while dense materials were compacted by pressing at 100 MPa, followed by thermal treatment (1100°C), grinding, and sieving. Extracts were prepared by 24-h incubation of granules on culture media, with subsequent exposition of human primary mesenchymal cells. Three different cell viability parameters were evaluated on the same samples. Scanning electron microscopy analysis of the granules revealed distinct dense and porous surfaces. After cell exposition to extracts, no significant differences on mitochondrial activity (2,3-bis(2-methoxy-4-nitro-5-sulfophenly)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide) or cell density (Crystal Violet Dye Elution) were observed among groups. However, Neutral Red assay revealed that dense materials extracts induced lower levels of total viable cells to porous HA/β-TCP (P < 0.01). Calcium ion content was also significantly lower on the extracts of dense samples. Porogenic treatments on BCP composites do not affect cytocompatibility, as measured by three different parameters, indicating that these ceramics are well suited for further studies on future bioengineering applications. PMID:22372877

  5. A novel squid pen chitosan/hydroxyapatite/β-tricalcium phosphate composite for bone tissue engineering.

    PubMed

    Shavandi, Amin; Bekhit, Alaa El-Din A; Sun, Zhifa; Ali, Azam; Gould, Maree

    2015-10-01

    Squid pen chitosan was used in the fabrication of biocomposite scaffolds for bone tissue engineering. Hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) obtained from waste mussel shells were used as the calcium phosphate source. The composite was prepared using 2.5% tripolyphosphate (TPP) and 1% glycerol as a cross-linker and plasticizer, respectively. The weight percent (wt.%) ratios of the ceramic components in the composite were 20/10/70, 30/20/50 and 40/30/30 (HA/β-TCP/Chi). The biodegradation rate and structural properties of the scaffolds were investigated. Scanning electron microscopy (SEM) and microCT(μCT) results indicated that the composites have a well defined lamellar structure with an average pore size of 200 μm. The porosity of the composites decreased from 88 to 56% by increasing the ratio of HA/β-TCP from 30 to 70%. After 28 days of incubation in a physiological solution, the scaffolds were degraded by approximately 30%. In vitro investigations showed that the composites were cytocompatible and supported the growth of L929 and Saos-2 cells. The obtained data suggests that the squid pen chitosan composites are potential candidates for bone regeneration. PMID:26117768

  6. Hybrid composites of calcium phosphate granules, fibrin glue, and bone marrow for skeletal repair.

    PubMed

    Le Nihouannen, Damien; Goyenvalle, Eric; Aguado, Eric; Pilet, Paul; Bilban, Melitta; Daculsi, Guy; Layrolle, Pierre

    2007-05-01

    Synthetic bone substitutes, such as calcium phosphate ceramics, give good results in clinical applications. In order to adapt to surgical sites, bioceramics come in the form of blocks or granules, and are either dense or porous. Combining these bioceramics with fibrin glue provides a mouldable and self-hardening composite biomaterial with the biochemical properties of each component. Critical-sized defects in the femoral condyle of rabbits were filled with TricOs/fibrin glue/bone marrow hybrid/composite material. The TricOs granules (1-2 mm) were composed of hydroxyapatite and beta tricalcium phosphate (60/40 in weight). The fibrin glue was composed of fibrinogen, thrombin and other biological factors and mixed with MBCP granules either simultaneously or sequentially. Bone marrow was also added to the MBCP/fibrin composite prior to filling the defects. After 3, 6, 12, and 24 weeks of implantation, the newly-formed bone was analysed with histology, histomorphometry and mechanical tests. The newly-formed bone had grown centripetally. Simultaneous application of fibrin glue showed better results for mechanical properties than sequential application after 6 weeks. Around 40% of bone had formed after 24 weeks in the three groups. Although the addition of bone marrow did not improve bone formation, the MBCP/fibrin material could be used in clinical bone filling applications. PMID:17117470

  7. Laser engineered multilayer coating of biphasic calcium phosphate/titanium nanocomposite on metal substrates.

    PubMed

    Zhang, Martin Yi; Ye, Chang; Erasquin, Uriel Joseph; Huynh, Toan; Cai, Chengzhi; Cheng, Gary J

    2011-02-01

    In this work, laser coating of biphasic calcium phosphate/titanium (BCP/Ti) nanocomposite on Ti-6Al-4 V substrates was developed. A continuous wave neodymium-doped yttrium aluminium garnet (Nd:YAG) laser was used to form a robust multilayer of BCP/Ti nanocomposite starting from hydroxyapatite and titanium nanoparticles. In this process, low power coating is realized because of the strong laser-nanoparticle interaction and good sinterability of nanosized titanium. To guide the optimization of laser processing conditions for the coating process, a multiphysics model coupling electromagnetic module with heat transfer module was developed. This model was validated by laser coating experiments. Important features of the coated samples, including microstructures, chemical compositions, and interfacial bonding strength, were characterized. We found that a multilayer of BCP, consisting of 72% hydroxyapatite (HA) and 28% beta-tricalcium phosphate (β-TCP), and titanium nanocomposite was formed on Ti-6Al-4 V substrates. Significantly, the coating/substrate interfacial bonding strength was found to be two times higher than that of the commercial plasma sprayed coatings. Preliminary cell culture studies showed that the resultant BCP/Ti nanocomposite coating supported the adhesion and proliferation of osteoblast-like UMR-106 cells. PMID:21207950

  8. Biogenic Calcium Phosphate Transformation in Soils over Millennium Time Scales

    SciTech Connect

    Sato, S.; Neves, E; Solomon, D; Liang, B; Lehmann, J

    2009-01-01

    Changes in bioavailability of phosphorus (P) during pedogenesis and ecosystem development have been shown for geogenic calcium phosphate (Ca-P). However, very little is known about long-term changes of biogenic Ca-P in soil. Long-term transformation characteristics of biogenic Ca-P were examined using anthropogenic soils along a chronosequence from centennial to millennial time scales. Phosphorus fractionation of Anthrosols resulted in overall consistency with the Walker and Syers model of geogenic Ca-P transformation during pedogenesis. The biogenic Ca-P (e.g., animal and fish bones) disappeared to 3% of total P within the first ca. 2,000 years of soil development. This change concurred with increases in P adsorbed on metal-oxides surfaces, organic P, and occluded P at different pedogenic time. Phosphorus K-edge X-ray absorption near-edge structure (XANES) spectroscopy revealed that the crystalline and therefore thermodynamically most stable biogenic Ca-P was transformed into more soluble forms of Ca-P over time. While crystalline hydroxyapatite (34% of total P) dominated Ca-P species after about 600-1,000 years, {Beta}-tricalcium phosphate increased to 16% of total P after 900-1,100 years, after which both Ca-P species disappeared. Iron-associated P was observable concurrently with Ca-P disappearance. Soluble P and organic P determined by XANES maintained relatively constant (58-65%) across the time scale studied. Conclusions - Disappearance of crystalline biogenic Ca-P on a time scale of a few thousand years appears to be ten times faster than that of geogenic Ca-P.

  9. Osteoclastogenesis and Osteoclastic Resorption of Tricalcium Phosphate: Effect of Strontium and Magnesium Doping

    PubMed Central

    Roy, Mangal; Bose, Susmita

    2012-01-01

    Bone substitute materials are required to support the remodeling process, which consists of osteoclastic resorption and osteoblastic synthesis. Osteoclasts, the bone resorbing cells, generate from differentiation of hemopoietic mononuclear cells. In the present study we have evaluated the effects of 1.0 wt% strontium (Sr) and 1.0 wt% magnesium (Mg) doping in beta-tricalcium phosphate (β-TCP) on the differentiation of mononuclear cells into osteoclast-like cells and its resorptive activity. In vitro osteoclast-like cell formation, adhesion, and resorption were studied using osteoclast precursor RAW 264.7 cell, supplemented with receptor activator of nuclear factor κβ ligand (RANKL). Osteoclast-like cell formation was noticed on pure and Sr doped β-TCP samples at day 8 which was absent on Mg doped β-TCP samples indicating decrease in initial osteoclast differentiation due to Mg doping. After 21 days of culture, osteoclast-like cell formation was evident on all samples with osteoclastic markers such as actin ring, multiple nuclei, and presence of vitronectin receptor αvβ3 integrin. After osteoclast differentiation, all substrates showed osteoclast-like cell mediated degradation, however; significantly restricted for Mg doped β-TCP samples. Our present results indicated substrate chemistry controlled osteoclast differentiation and resorptive activity which can be used in designing TCP based resorbable bone substitutes with controlled degradation properties. PMID:22566212

  10. Microstructure, mechanical characteristics and cell compatibility of β-tricalcium phosphate reinforced with biodegradable Fe-Mg metal phase.

    PubMed

    Swain, Sanjaya K; Gotman, Irena; Unger, Ronald; Kirkpatrick, C James; Gutmanas, Elazar Y

    2016-01-01

    The use of beta-tricalcium phosphate (β-TCP) ceramic as a bioresorbable bone substitute is limited to non-load-bearing sites by the material׳s brittleness and low bending strength. In the present work, new biocompatible β-TCP-based composites with improved mechanical properties were developed via reinforcing the ceramic matrix with 30 vol% of a biodegradable iron-magnesium metallic phase. β-TCP-15Fe15Mg and β-TCP-24Fe6Mg (vol%) composites were fabricated using a combination of high energy attrition milling, cold sintering/high pressure consolidation of powders at room temperature and annealing at 400 °C. The materials synthesized had a hierarchical nanocomposite structure with a nanocrystalline β-TCP matrix toughened by a finely dispersed nanoscale metallic phase (largely Mg) alongside micron-scale metallic reinforcements (largely Fe). Both compositions exhibited high strength characteristics; in bending, they were about 3-fold stronger than β-TCP reinforced with 30 vol% PLA polymer. Immersion in Ringer׳s solution for 4 weeks resulted in formation of corrosion products on the specimens׳ surface, a few percent weight loss and about 50% decrease in bending strength. In vitro studies of β-TCP-15Fe15Mg composite with human osteoblast monocultures and human osteoblast-endothelial cell co-cultures indicated that the composition was biocompatible for the growth and survival of both cell types and cells exhibited tissue-specific markers for bone formation and angiogenesis, respectively. PMID:26409234

  11. Minimally Invasive Alveolar Ridge Preservation Utilizing an In Situ Hardening β-Tricalcium Phosphate Bone Substitute: A Multicenter Case Series.

    PubMed

    Leventis, Minas D; Fairbairn, Peter; Kakar, Ashish; Leventis, Angelos D; Margaritis, Vasileios; Lückerath, Walter; Horowitz, Robert A; Rao, Bappanadu H; Lindner, Annette; Nagursky, Heiner

    2016-01-01

    Ridge preservation measures, which include the filling of extraction sockets with bone substitutes, have been shown to reduce ridge resorption, while methods that do not require primary soft tissue closure minimize patient morbidity and decrease surgical time and cost. In a case series of 10 patients requiring single extraction, in situ hardening beta-tricalcium phosphate (β-TCP) granules coated with poly(lactic-co-glycolic acid) (PLGA) were utilized as a grafting material that does not necessitate primary wound closure. After 4 months, clinical observations revealed excellent soft tissue healing without loss of attached gingiva in all cases. At reentry for implant placement, bone core biopsies were obtained and primary implant stability was measured by final seating torque and resonance frequency analysis. Histological and histomorphometrical analysis revealed pronounced bone regeneration (24.4 ± 7.9% new bone) in parallel to the resorption of the grafting material (12.9 ± 7.7% graft material) while high levels of primary implant stability were recorded. Within the limits of this case series, the results suggest that β-TCP coated with polylactide can support new bone formation at postextraction sockets, while the properties of the material improve the handling and produce a stable and porous bone substitute scaffold in situ, facilitating the application of noninvasive surgical techniques. PMID:27190516

  12. Minimally Invasive Alveolar Ridge Preservation Utilizing an In Situ Hardening β-Tricalcium Phosphate Bone Substitute: A Multicenter Case Series

    PubMed Central

    Leventis, Minas D.; Fairbairn, Peter; Kakar, Ashish; Leventis, Angelos D.; Margaritis, Vasileios; Lückerath, Walter; Horowitz, Robert A.; Rao, Bappanadu H.; Lindner, Annette; Nagursky, Heiner

    2016-01-01

    Ridge preservation measures, which include the filling of extraction sockets with bone substitutes, have been shown to reduce ridge resorption, while methods that do not require primary soft tissue closure minimize patient morbidity and decrease surgical time and cost. In a case series of 10 patients requiring single extraction, in situ hardening beta-tricalcium phosphate (β-TCP) granules coated with poly(lactic-co-glycolic acid) (PLGA) were utilized as a grafting material that does not necessitate primary wound closure. After 4 months, clinical observations revealed excellent soft tissue healing without loss of attached gingiva in all cases. At reentry for implant placement, bone core biopsies were obtained and primary implant stability was measured by final seating torque and resonance frequency analysis. Histological and histomorphometrical analysis revealed pronounced bone regeneration (24.4 ± 7.9% new bone) in parallel to the resorption of the grafting material (12.9 ± 7.7% graft material) while high levels of primary implant stability were recorded. Within the limits of this case series, the results suggest that β-TCP coated with polylactide can support new bone formation at postextraction sockets, while the properties of the material improve the handling and produce a stable and porous bone substitute scaffold in situ, facilitating the application of noninvasive surgical techniques. PMID:27190516

  13. Resolution-enhanced Fourier transform infrared spectroscopy study of the environment of phosphate ions in the early deposits of a solid phase of calcium-phosphate in bone and enamel, and their evolution with age. I: Investigations in the upsilon 4 PO4 domain.

    PubMed

    Rey, C; Shimizu, M; Collins, B; Glimcher, M J

    1990-06-01

    In order to investigate the possible existence in biological and poorly crystalline synthetic apatites of local atomic organizations different from that of apatite, resolution-enhanced, Fourier transform infrared spectroscopy studies were carried out on chicken bone, pig enamel, and poorly crystalline synthetic apatites containing carbonate and HPO4(2-) groups. The spectra obtained were compared to those of synthetic well crystallized apatites (stoichiometric hydroxyapatite, HPO4(2-)-containing apatite, type B carbonate apatite) and nonapatitic calcium phosphates which have been suggested as precursors of the apatitic phase [octacalcium phosphate (OCP), brushite, and beta tricalcium phosphate and whitlockite]. The spectra of bone and enamel, as well as poorly crystalline, synthetic apatite in the upsilon 4 PO4 domain, exhibit, in addition to the three apatitic bands, three absorption bands that were shown to be independent of the organic matrix. Two low-wave number bands at 520-530 and 540-550 cm-1 are assigned to HPO4(2-). Reference to known calcium phosphates shows that bands in this domain also exist in HPO4(2-)-containing apatite, brushite, and OCP. However, the lack of specific absorption bands prevents a clear identification of these HPO4(2-) environments. The third absorption band (610-615 cm-1) is not related to HPO4(2-) or OH- ions. It appears to be due to a labile PO4(3-) environment which could not be identified with any phosphate environment existing in our reference samples, and thus seems specific of poorly crystalline apatites. Correlation of the variations in band intensities show that 610-615 cm-1 band is related to an absorption band at 560 cm-1 superimposed on an apatite band. All the nonapatitic phosphate environments were shown to decrease during aging of enamel, bone, and synthetic apatites. Moreover, EDTA etching show that the labile PO4(3-) environment exhibited a heterogeneous distribution in the insoluble precipitate. PMID:2364326

  14. Physical properties and cellular responses to calcium phosphate coating produced by laser rapid forming on titanium.

    PubMed

    Gao, Y; Hu, J; Guan, T H; Wu, J; Zhang, C B; Gao, B

    2014-01-01

    In order to improve the surface bioactivity of titanium implants, CaCO₃ and CaHPO₄·2H₂O powder was used to fabricate a calcium phosphate (CaP) coating using laser rapid forming (LRF) technology. The surface characterization showed that a porous and beta-tricalcium phosphate (beta-TCP) layer with small amount of alpha-TCP was formed on commercial pure titanium (Ti). The bonding strength between the coating and the Ti substrate was above 40.17 MPa measured by the means of pull-off test. The elastic modulus and the average microhardness of the coating were 117.61 GPa and 431.2 HV₀.₁, respectively. Through the static immersion test, it was proved that the coating could not only prevent the corrosion of Ti but also promote the redeposition of beta-TCP in artificial saliva. Osteoblasts possessed good attachment performance and strong proliferation ability on the surface of LRF coating (p < 0.05) in our cell experiments. This result demonstrated that the LRF coating could improve the surface cytocompatibility of titanium. Using scanning electron microscopy observation, it was found that osteoblasts grown on LRF coating formed multiple layers in pours. The result of reverse transcription PCR analysis demonstrated that the expressions of ITGβ1 and BMP-2 were significantly (p < 0.05) upregulated on the LRF coating in a time-dependent manner, compared with uncoated Ti. These findings suggested that the LRF technology might be a promising potential treatment for fabricating CaP coatings on titanium implants. PMID:23139072

  15. Chemical, modulus and cell attachment studies of reactive calcium phosphate filler-containing fast photo-curing, surface-degrading, polymeric bone adhesives.

    PubMed

    Abou Neel, E A; Palmer, G; Knowles, J C; Salih, V; Young, A M

    2010-07-01

    The initial structure, setting and degradation processes of a poly(lactide-co-propylene glycol-co-lactide) dimethacrylate adhesive filled with 50, 60 or 70 wt.% reactive calcium phosphates (monocalcium phosphate monohydrate (MCPM)/beta-tricalcium phosphate (beta-TCP)) have been assessed using nuclear magnetic resonance, Fourier transform infrared spectroscopy, Raman, X-ray powder diffraction and gravimetric studies. Filler incorporation reduced the rapid light-activated monomer polymerization rates slightly, but not the final levels. Upon immersion in water for 24h, the set composite mass and volume increased due to water sorption. This promoted initial soluble MCPM loss from the composite surfaces, but also its reaction and monetite precipitation within the specimen bulk. After 48 h, composite gravimetric and chemical studies were consistent with surface erosion of polymer with reacted/remaining filler. The filled formulations exhibited more rapid early water sorption and subsequent surface erosion than the unfilled polymer. Calcium and phosphate release profiles and solution pH measurements confirmed early loss of surface MCPM with protons from polymer degradation products. At later times, the slower release of monetite/beta-TCP buffered composite storage solutions at approximately 5 instead of 3.2 for the unfilled polymer. Incorporation of filler increased both the early and later time material modulus. At intermediate times this effect was lost, presumably as a result of enhanced water sorption. The early modulus values obtained fell within the range reported for cancellous bone. Despite surface degradation, initial human mesenchymal cell attachment to both composites and polymer could be comparable with a non-degrading positive Thermanox control. These studies indicate that the filled formulations may be good candidates for bone repair. Release of calcium and phosphate ions provides components essential for such repair. PMID:20085828

  16. Phosphate salts

    MedlinePlus

    ... taken by mouth or used as enemas. Indigestion. Aluminum phosphate and calcium phosphate are FDA-permitted ingredients ... Phosphate salts containing sodium, potassium, aluminum, or calcium are LIKELY SAFE for most people when taken by mouth short-term, when sodium phosphate is inserted into the ...

  17. Fabrication of blended polycaprolactone/poly(lactic-co-glycolic acid)/β-tricalcium phosphate thin membrane using solid freeform fabrication technology for guided bone regeneration.

    PubMed

    Shim, Jin-Hyung; Huh, Jung-Bo; Park, Ju Young; Jeon, Young-Chan; Kang, Seong Soo; Kim, Jong Young; Rhie, Jong-Won; Cho, Dong-Woo

    2013-02-01

    This study developed a bioabsorbable-guided bone regeneration membrane made of blended polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and beta-tricalcium phosphate (β-TCP) using solid freeform fabrication (SFF) technology. The chemical and physical properties of the membrane were evaluated using field emission scanning electron microscopy, energy dispersive spectroscopy, and a tensile test. In vitro cell activity assays revealed that the adhesion, proliferation, and osteogenic differentiation of seeded adipose-derived stem cells (ADSCs) were significantly promoted by the PCL/PLGA/β-TCP membranes compared with PCL/PLGA membranes. When the PCL/PLGA and PCL/PLGA/β-TCP membranes were implanted on rabbit calvaria bone defects without ADSCs, microcomputed tomography and histological analyses confirmed that the SFF-based PCL/PLGA/β-TCP membranes greatly increased bone formation without the need for bone substitute materials. Moreover, tight integration, which helps to prevent exposure of the membrane, between both membranes and the soft tissues was clearly observed histologically. The SFF-based PCL/PLGA and PCL/PLGA/β-TCP membranes retained their mechanical stability for up to 8 weeks without significant collapse. Furthermore, PCL/PLGA/β-TCP underwent adequate degradation without a significant immune response at 8 weeks. PMID:22934667

  18. Effects of Zinc and Strontium Substitution in Tricalcium Phosphate on Osteoclast Differentiation and Resorption

    PubMed Central

    Roy, Mangal; Fielding, Gary; Bandyopadhyay, Amit; Bose, Susmita

    2013-01-01

    Bone replacement materials must be able to regulate both osteoblastic synthesis of new bone and osteoclastic resorption process in order to maintain the balance of bone remodeling. Osteoclasts generate from differentiation of mononuclear cells. In the present study, we have studied the osteoclast-like-cells responses (differentiation from mononuclear cells and resorption) to beta tricalcium phosphate (β-TCP) doped with zinc (Zn) and strontium (Sr). Osteoclast-like-cells differentiation and resorption was studied in vitro using osteoclast-like-cells precursor RAW 264.7 cell, supplemented with receptor activator of nuclear factor κβ ligand (RANKL). Morphological and immunohistochemical analysis confirmed successful differentiation of osteoclast-like-cells on the doped and undoped β-TCP substrates after 8 days of culture. Cells on the substrate surface expressed specific osteoclast markers such as; actin ring, multiple nucleus, tartrate-resistant acid phosphatase (TRAP) synthesis, and vitronectin receptor. However, quantitative TRAP assay indicated the inhibiting effect of Zn on osteoclast differentiation. Although, Zn doped β-TCP restricted osteoclast-like-cells differentiation, the samples were resorbed much faster. An increased resorption pit volume was noticed on Zn doped β-TCP samples after 28 days of culture compared to pure and Sr doped β-TCP. In this work, we demonstrated that β-TCP bone substitute materials can be successfully resorbed by osteoclast-like-cells, where both osteoclast-like-cells differentiation and resorption were modulated by Zn and/or Sr doping- a much needed property for successful bone remodeling. PMID:24244866

  19. Evaluation of human recombinant bone morphogenetic protein-2-loaded tricalcium phosphate implants in rabbits' bone defects.

    PubMed

    Laffargue, P; Hildebrand, H F; Rtaimate, M; Frayssinet, P; Amoureux, J P; Marchandise, X

    1999-08-01

    Porous beta-tricalcium phosphate (betaTCP) has osteoconductive properties. The adsorption of human recombinant bone morphogenetic protein-2 (rhBMP-2) onto TCP could realize an osteoinductive bone substitute. We evaluated it on an animal model using dual-energy X-ray absorptiometry (DEXA) and solid-state 31P nuclear magnetic resonance (NMR) spectroscopy. BetaTCP cylinders loaded with rhBMP-2 were implanted into rabbits' femoral condyle bone defects, and betaTCP alone as control into the contralateral femur. We studied two different doses of rhBMP-2 (10 and 40 microg) on two groups of four animals. Evaluation consisted in radiography, histology, and histomorphometry, DEXA, and NMR spectroscopy using an original method of quantification. With both doses of rhBMP-2, we observed on radiographs an increase of trabecular bone around implants. Histology showed resorption of the ceramic, trabecular bone with osteoblasts and osteoid substance around the implants, and colonization inside the porous betaTCP by new bone formed. Histomorphometry showed that the osteoid surface (OS/BS) was greatest with the high dose of rhBMP-2. The difference was slight between the low dose of rhBMP-2 and control. DEXA showed a dose-dependent increase of bone mineral density of rhBMP-2-loaded betaTCP vs. control. NMR spectroscopy confirmed that the amount of new bone formed in betaTCP was greater when betaTCP carried rhBMP-2, and increased with the dose of rhBMP-2 used. We showed that betaTCP was a good matrix for rhBMP-2, which gave it osteoinductive properties in an orthotopic site, in a dose-dependent manner. Thus, such composite biomaterial seems to be of great interest in reconstructive bone surgery. Further studies are needed in clinical practice to determine optimal doses. PMID:10458276

  20. Phosphate salts

    MedlinePlus

    ... as a laxative to clean the bowels before surgery or intestinal tests. Healthcare providers sometimes give potassium phosphate intravenously (by IV) for treating low phosphate and high calcium levels in the blood, and for preventing low phosphate in patients who are being tube-fed.

  1. Equation of State for TI-BETA-21S

    NASA Astrophysics Data System (ADS)

    Honnell, Kevin G.; Velisavljevic, Nenad; Adams, Chris D.; Rigg, Paulo A.; Chesnut, Gary N.; Aikin, Robert M.; Boettger, Jonathan C.

    2007-12-01

    A new, tabular, SESAME equation of state, along with new diamond-anvil, Hugoniot, and thermal-expansion data, is presented for Ti-Beta-21S (TIMETAL® 21S), a high-strength, high-temperature, beta-stabilized alloy of Ti, Mo, Nb, Al and Si. The new equation of state combines an empirical, Vinet description of the cold curve with the Johnson ionic model and the Thomas-Fermi-Dirac model for the thermal electronic contributions. Two coexisting phases, HCP (α) and BCC (β), are observed at room temperature and pressure, with the α phase disappearing above 67 GPa. Predictions for the room-temperature isotherm, principal Hugoniot, thermal expansion, and heat capacity are compared to new and existing experimental results.

  2. Analysis of β-tricalcium phosphate granules prepared with different formulations by nano-computed tomography and scanning electron microscopy.

    PubMed

    Terranova, Lisa; Libouban, Hélène; Mallet, Romain; Chappard, Daniel

    2015-12-01

    Among biomaterials used for filling bone defects, beta-tricalcium phosphate (β-TCP) is suitable in non-bearing bones, particularly in dental implantology, oral and maxillofacial surgery. When β-TCP granules are placed in a bone defect, they occupy the void 3D volume. Little is known about the 3D arrangement of the granules, which depends on the nature and size of the granules. The aim of this study was to examine the 3D architecture of porous β-TCP granules. Granules were prepared with different concentrations of β-TCP powder in slurry (10, 11, 15, 18, 21, and 25 g of β-TCP powder in distilled water). Granules were prepared by the polyurethane foam method. They were analyzed by nano-computed tomography (nanoCT) and compared with scanning electron microscopy (SEM). Commercial granules of hydroxyapatite-β-TCP prepared by the same methodology were also used. The outer and inner architectures of the granules were shown by nanoCT which evidenced macroporosity, internal porosity and microporosity between the sintered grains. Macroporosity was reduced at high concentration and conversely, numerous concave surfaces were observed. Internal porosity, related to the sublimation of the polyurethane foam, was present in all the granules. Microporosity at the grain joints was evidenced by SEM and on 2D nanoCT sections. Granules presented a heterogeneous aspect due to the different mineralization degree of the sintered powder grains in the β-TCP granules; the difference between hydroxyapatite and β-TCP was also evidenced. NanoCT is an interesting method to analyze the fine morphology of biomaterials with a resolution close to synchrotron and better than microcomputed tomography. PMID:25899237

  3. Microscopic, crystallographic and adherence properties of plasma-sprayed calcium phosphate coatings on Ti-6Al-4V

    NASA Astrophysics Data System (ADS)

    Tufekci, Eser

    Recently, plasma-spayed titanium implants have become very popular in the dentistry because of their biocompatibility and ability of providing osseointegration with the surrounding bone. Although there are numerous published studies on these materials, information and standards are still lacking. This study investigated the miscrostructural, crystallographic and adherence properties of plasma-sprayed hydroxyapatite coatings on Ti-6Al-4V substrates. The microstructures of the coatings and the elemental interdiffusion near the coating/substrate interface were investigated using a scanning electron microscope (SEM) equipped with x-ray energy-dispersive spectroscopy (EDS). X-ray diffraction analyses performed on Ti-6Al-4V coupons prepared with different percent crystallinities have provided structural information such as degree of crystallinity, phases present, average crystallite size, as well as the residual stresses within the coating. For evaluation of the adherence of the coatings to the substrates, experimental rods were subjected to torsion. The fracture surfaces were analyzed using SEM/EDS to develop a new methodology to determine the percent adherence of the coatings. SEM studies indicated that the surface microstructures of commercial dental implants were consistent with the plasma-spraying. In cross-section, coatings exhibited minimal porosity and limited interdiffusion of titanium and calcium at the coating/substrate interface. X-ray diffraction analyses indicated that the highest crystallinity coatings consisted of almost entirely HA and an amorphous calcium phosphate phase. As the coating crystallinity decreased, increasing amounts of alpha- and beta-tricalcium phosphate and tetracalcium phosphate were detected. The mean percent crystallinity for the three sets of coatings ranged from 50-60%. The mean HA crystallite size for the three sets of coatings ranged from about 0.02-0.04 mum. Differences in mean interplanar spacings for three selected

  4. Mechanical properties and in vitro cellular behavior of zinc-containing nano-bioactive glass doped biphasic calcium phosphate bone substitutes.

    PubMed

    Badr-Mohammadi, Mohammad-Reza; Hesaraki, Saeed; Zamanian, Ali

    2014-01-01

    In the present study, different amounts (0.5-5 wt%) of a sol gel-derived zinc-containing nano-bioactive glass (NBG-Zn) powder were added to biphasic calcium phosphate (BCP). The mixtures were sintered at 1,100-1,300 °C and physical characteristics, mechanical properties, phase composition and morphology of them were studied. The samples were also soaked in human blood plasma for 15 days to evaluate variations in their surface morphologies. Rat calvarium-derived osteoblastic cells were seeded on tops of various samples and cell adhesion, proliferation, and alkaline phosphatase activity were evaluated at different culturing periods. The maximum bending strength (62 MPa) was obtained for BCP containing 0.5 wt% NBG-Zn at temperature 1,200 °C. This value was approximately 80% higher than that of pure BCP. The bending strength failed when both sintering temperature and amount of added NBG-Zn increased. At 1,100 °C, NBG-Zn additive did not change the phase composition of BCP. At temperatures 1,200 and 1,300 °C, both alpha-tricalcium calcium phosphate (α-TCP) and beta-tricalcium phosphate (β-TCP and) phases were detected. However, adding higher amount of NBG-Zn to BCP resulted in elevation of β-TCP at 1,200 °C and progression of α-TCP at 1,300 °C. Based on the microscopic observations, adding 0.5 wt% NBG-Zn to BCP led to disappearance of grain boundaries, reduction of micropores and formation of a monolithic microstructure. No calcium phosphate precipitation was observed on sample surfaces after soaking in blood plasma, but some pores were produced by phase dissolution. The size and volume of these pores were directly proportional to NBG-Zn content. Based on the cell studies, both BCP and NBG-Zn-added BCP samples supported attachment and proliferation of osteoblasts, but higher alkaline phosphatase enzyme was synthesized within the cells cultured on NBG-Zn-added BCP. Overall, biphasic calcium phosphate materials with improved mechanical and biological properties

  5. Next-generation resorbable polymer scaffolds with surface-precipitated calcium phosphate coatings

    PubMed Central

    Kim, Jinku; Magno, Maria Hanshella R.; Ortiz, Ophir; McBride, Sean; Darr, Aniq; Kohn, Joachim; Hollinger, Jeffrey O.

    2015-01-01

    Next-generation synthetic bone graft therapies will most likely be composed of resorbable polymers in combination with bioactive components. In this article, we continue our exploration of E1001(1k), a tyrosine-derived polycarbonate, as an orthopedic implant material. Specifically, we use E1001(1k), which is degradable, nontoxic, and osteoconductive, to fabricate porous bone regeneration scaffolds that were enhanced by two different types of calcium phosphate (CP) coatings: in one case, pure dicalcium phosphate dihydrate was precipitated on the scaffold surface and throughout its porous structure (E1001(1k) + CP). In the other case, bone matrix minerals (BMM) such as zinc, manganese and fluoride were co-precipitated within the dicalcium phosphate dihydrate coating (E1001(1k) + BMM). These scaffold compositions were compared against each other and against ChronOS (Synthes USA, West Chester, PA, USA), a clinically used bone graft substitute (BGS), which served as the positive control in our experimental design. This BGS is composed of poly(lactide co-ε-caprolactone) and beta-tricalcium phosphate. We used the established rabbit calvaria critical-sized defect model to determine bone regeneration within the defect for each of the three scaffold compositions. New bone formation was determined after 2, 4, 6, 8 and 12 weeks by micro-computerized tomography (μCT) and histology. The experimental tyrosine-derived polycarbonate, enhanced with dicalcium phosphate dihydrate, E1001(1k) + CP, supported significant bone formation within the defects and was superior to the same scaffold containing a mix of BMM, E1001(1k) + BMM. The comparison with the commercially available BGS was complicated by the large variability in bone formation observed for the laboratory preparations of E1001(1k) scaffolds. At all time points, there was a trend for E1001(1k) + CP to be superior to the commercial BGS. However, only at the 6-week time point did this trend reach statistical significance

  6. Microbial solubilization of phosphate

    DOEpatents

    Rogers, R.D.; Wolfram, J.H.

    1993-10-26

    A process is provided for solubilizing phosphate from phosphate containing ore by treatment with microorganisms which comprises forming an aqueous mixture of phosphate ore, microorganisms operable for solubilizing phosphate from the phosphate ore and maintaining the aqueous mixture for a period of time and under conditions operable to effect the microbial solubilization process. An aqueous solution containing soluble phosphorus can be separated from the reacted mixture by precipitation, solvent extraction, selective membrane, exchange resin or gravity methods to recover phosphate from the aqueous solution. 6 figures.

  7. Microbial solubilization of phosphate

    DOEpatents

    Rogers, Robert D.; Wolfram, James H.

    1993-01-01

    A process is provided for solubilizing phosphate from phosphate containing ore by treatment with microorganisms which comprises forming an aqueous mixture of phosphate ore, microorganisms operable for solubilizing phosphate from the phosphate ore and maintaining the aqueous mixture for a period of time and under conditions operable to effect the microbial solubilization process. An aqueous solution containing soluble phosphorous can be separated from the reacted mixture by precipitation, solvent extraction, selective membrane, exchange resin or gravity methods to recover phosphate from the aqueous solution.

  8. Glucose-6-phosphate dehydrogenase

    MedlinePlus

    ... this page: //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 type of ...

  9. Chloroquine Phosphate Oral

    MedlinePlus

    ... allergic to chloroquine phosphate, chloroquine hydrochloride (Aralen HCl), hydroxychloroquine (Plaquenil), or any other drugs.tell your doctor ... taking chloroquine phosphate, chloroquine hydrochloride (Aralen HCl), or hydroxychloroquine (Plaquenil).tell your doctor if you are pregnant ...

  10. Chloroquine Phosphate Oral

    MedlinePlus

    ... allergic to chloroquine phosphate, chloroquine hydrochloride (Aralen HCl), hydroxychloroquine (Plaquenil), or any other drugs.tell your doctor and ... taking chloroquine phosphate, chloroquine hydrochloride (Aralen HCl), or hydroxychloroquine (Plaquenil).tell your doctor if you are pregnant ...

  11. Uranium from phosphate ores

    SciTech Connect

    Hurst, F.J.

    1983-01-01

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

  12. To Your Health: NLM update transcript - Tobacco 21's health benefits

    MedlinePlus

    ... nih.gov/medlineplus/podcast/transcript051616.html To Your Health: NLM update Transcript Tobacco 21's health benefits : 05/16/2016 To use the sharing ... is what's new this week in To Your Health — a consumer health oriented podcast from NLM — that ...

  13. Phosphate, inositol and polyphosphates.

    PubMed

    Livermore, Thomas M; Azevedo, Cristina; Kolozsvari, Bernadett; Wilson, Miranda S C; Saiardi, Adolfo

    2016-02-15

    Eukaryotic cells have ubiquitously utilized the myo-inositol backbone to generate a diverse array of signalling molecules. This is achieved by arranging phosphate groups around the six-carbon inositol ring. There is virtually no biological process that does not take advantage of the uniquely variable architecture of phosphorylated inositol. In inositol biology, phosphates are able to form three distinct covalent bonds: phosphoester, phosphodiester and phosphoanhydride bonds, with each providing different properties. The phosphoester bond links phosphate groups to the inositol ring, the variable arrangement of which forms the basis of the signalling capacity of the inositol phosphates. Phosphate groups can also form the structural bridge between myo-inositol and diacylglycerol through the phosphodiester bond. The resulting lipid-bound inositol phosphates, or phosphoinositides, further expand the signalling potential of this family of molecules. Finally, inositol is also notable for its ability to host more phosphates than it has carbons. These unusual organic molecules are commonly referred to as the inositol pyrophosphates (PP-IPs), due to the presence of high-energy phosphoanhydride bonds (pyro- or diphospho-). PP-IPs themselves constitute a varied family of molecules with one or more pyrophosphate moiety/ies located around the inositol. Considering the relationship between phosphate and inositol, it is no surprise that members of the inositol phosphate family also regulate cellular phosphate homoeostasis. Notably, the PP-IPs play a fundamental role in controlling the metabolism of the ancient polymeric form of phosphate, inorganic polyphosphate (polyP). Here we explore the intimate links between phosphate, inositol phosphates and polyP, speculating on the evolution of these relationships. PMID:26862212

  14. Zinc phosphate conversion coatings

    DOEpatents

    Sugama, T.

    1997-02-18

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate {alpha}-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal. 33 figs.

  15. Zinc phosphate conversion coatings

    DOEpatents

    Sugama, Toshifumi

    1997-01-01

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

  16. CADMIUM PHOSPHATE GLASS

    DOEpatents

    Carpenter, H.W.; Johnson, P.D.

    1963-04-01

    A method of preparing a cadmium phosphate glass that comprises providing a mixture of solid inorganic compounds of cadmuim and phosphate having vaporizable components and heating the resulting composition to a temperature of at least 850 un. Concent 85% C is presented. (AEC)

  17. The effect of calcium phosphate composite scaffolds on the osteogenic differentiation of rabbit dental pulp stem cells.

    PubMed

    Ling, Ling E; Feng, Lin; Liu, Hong-Chen; Wang, Dong-Sheng; Shi, Zhan-Ping; Wang, Jun-Cheng; Luo, Wei; Lv, Yan

    2015-05-01

    The objective of this study is to compare the effects of the two calcium phosphate composite scaffolds on the attachment, proliferation, and osteogenic differentiation of rabbit dental pulp stem cells (DPSCs). One nano-hydroxyapatite/collagen/poly (l-lactide) (nHAC/PLA), imitating the composition and the micro-structure characteristics of the natural bone, was made by Beijing Allgens Medical Science & Technology Co., Ltd. (China). The other beta-tricalcium phosphate (β-TCP), being fully interoperability globular pore structure, was provided by Shanghai Bio-lu Biomaterials Co, Ltd. (China). We compared the absorption water rate and the protein adsorption rate of two scaffolds and the characterization of DPSCs cultured on the culture plate and both scaffolds under osteogenic differentiation media (ODM) treatment. The constructs were then implanted subcutaneously into the back of severely combined immunodeficient (SCID) mice for 8 and 12 weeks to compare their bone formation capacity. The results showed that the ODM-treated DPSCs expressed osteocalcin (OCN), bone sialoprotein (BSP), type I collagen (COLI) and osteopontin (OPN) by immunofluorescence staining. Positive alkaline phosphatase (ALP) staining, calcium deposition and calcium nodules were also observed on the ODM-treated DPSCs. The absorption water rate and protein adsorption rate of nHAC/PLA was significantly higher than β-TCP. The initial attachment of DPSCs seeded onto nHAC/PLA was significantly higher than that onto β-TCP; and the proliferation rate of the cells was also significantly higher than that of β-TCP on 1, 3, and 7 days of cell culture. The ALP activity, calcium/phosphorus content and mineral formation of DPSCs + β-TCP were significantly higher than DPSCs + nHAC/LA. When implanted into the back of SCID mice, nHAC/PLA alone had no new bone formation, newly formed mature bone and osteoid were only observed in β-TCP alone, DPSCs + nHAC/PLA and DPSCs + β-TCP, and this three

  18. PHOSPHATE MANAGEMENT: FY2010 RESULTS OF PHOSPHATE PRECIPITATION TESTS

    SciTech Connect

    Hay, M.; King, W.

    2011-04-04

    The Phosphate Management program seeks to develop treatment options for caustic phosphate solutions resulting from the caustic leaching of the bismuth phosphate sludge. The SRNL subtask investigated the precipitation of phosphate salts from caustic solutions through addition of fluoride and by crystallization. The scoping tests examined the: precipitation of phosphate by the addition of sodium fluoride to form the sodium fluorophosphate double salt, Na{sub 7}F(PO{sub 4}){sub 2} {center_dot} 19H{sub 2}O, crystallization of phosphate by reducing the temperature of saturated phosphate solutions, and combinations of precipitation and crystallization. A simplified leachate simulant was used in the study produced by dissolving sodium phosphate in 1 M to 3.5 M sodium hydroxide solutions. The results show that all three processes; precipitation with sodium fluoride, crystallization, and combined precipitation/crystallization can be effective for removing large amounts of phosphate from solution. The combined process of precipitation/crystallization showed >90% removal of phosphate at all hydroxide concentrations when cooling a non-saturated phosphate solution from 65 C to 25 C. Based on the measured solubility of sodium phosphate, pH adjustment/caustic addition will also remove large amounts of phosphate from solution (>80%). For all three processes, the phosphate concentration in the caustic solution must be managed to keep the phosphate from becoming too concentrated and thereby potentially forming a solid mass of sodium phosphate after an effective phosphate removal process.

  19. Biosynthesis of Dolichyl Phosphate

    PubMed Central

    Hopp, H. Esteban; Daleo, Gustavo R.; Romero, Pedro A.; Lezica, Rafael Pont

    1978-01-01

    This is the first report not only on the presence of polyprenyl phosphates and their site of synthesis in algae, but also on the formation of their sugar derivatives in this system. A glucose acceptor lipid was isolated from the nonphotosynthetic alga Prototheca zopfii. The lipid was acidic and resistant to mild acid and alkaline treatments. The glucosylated lipid was labile to mild acid hydrolysis and resistant to phenol treatment and catalytic hydrogenation, as dolichyl phosphate glucose is. These results are consistent with the properties of an α-saturated polyprenyl phosphate. The polyprenylic nature of the lipid was confirmed by biosynthesis from radioactive mevalonate. The [14C]lipid had the same chromatographic properties as dolichyl phosphate in DEAE-cellulose and Sephadex LH-20. Strong alkaline treatment and enzymic hydrolysis liberated free alcohols with chain lengths ranging from C90 to C105, C95 and C100 being the most abundant molecular forms. The glucose acceptor activity of the biosynthesized polyprenyl phosphate was confirmed. The ability of different subcellular fractions to synthesize dolichyl phosphate was studied. Mitochondria and the Golgi apparatus were the sites of dolichyl phosphate synthesis from mevalonate. PMID:16660269

  20. Metal-phosphate binders

    DOEpatents

    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.

  1. Phosphate control in dialysis

    PubMed Central

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

    2013-01-01

    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. PMID:24133374

  2. Modelling of calcium phosphates

    NASA Astrophysics Data System (ADS)

    Calderin Hidalgo, Lazaro Juan

    This work is a contribution to a large scale joint experimental and theoretical effort to understand the biological properties of silicon doped calcium phosphates undertaken by Queen's University and Millenium Biologix Corp. We have modeled calcium phosphates and silicon doped calcium phosphates in close relation to experiment in order to study possible location of silicon in the lattice. Density functional theory has been used to study the structural and dynamical properties of small systems of calcium phosphates to gain preliminary information on phosphates and the performance of the theoretical methods. The same methods were used to investigate structural and electronic properties of larger scale calcium phosphate systems, while a classical shell model was developed to investigate the dynamical properties of such large and complex systems. In the context of the shell model a method was devised to calculate the dynamical matrix corrected for the long range Coulomb interaction in the long wave length limit. It was necessary also to develop a theoretical expression for the dielectric function in the context of the shell model. Infrared spectra and thermal parameters were calculated based on these methods. We also propose some directions for future research.

  3. Glucose-6-phosphate isomerase.

    PubMed

    Achari, A; Marshall, S E; Muirhead, H; Palmieri, R H; Noltmann, E A

    1981-06-26

    Glucose-6-phosphate isomerase (EC 5.3.1.9) is a dimeric enzyme of molecular mass 132000 which catalyses the interconversion of D-glucose-6-phosphate and D-fructose-6-phosphate. The crystal structure of the enzyme from pig muscle has been determined at a nominal resolution of 2.6 A. The structure is of the alpha/beta type. Each subunit consists of two domains and the active site is in both the domain interface and the subunit interface (P.J. Shaw & H. Muirhead (1976), FEBS Lett. 65, 50-55). Each subunit contains 13 methionine residues so that cyanogen bromide cleavage will produce 14 fragments, most of which have been identified and at least partly purified. Sequence information is given for about one-third of the molecule from 5 cyanogen bromide fragments. One of the sequences includes a modified lysine residue. Modification of this residue leads to a parallel loss of enzymatic activity. A tentative fit of two of the peptides to the electron density map has been made. It seems possible that glucose-6-phosphate isomerase, triose phosphate isomerase and pyruvate kinase all contain a histidine and a glutamate residue at the active site. PMID:6115414

  4. Phosphate Mines, Jordan

    NASA Technical Reports Server (NTRS)

    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.

  5. Mechanical properties of coated titanium Beta-21S after exposure to air at 700 and 800 C

    NASA Technical Reports Server (NTRS)

    Wiedemann, Karl E.; Bird, R. Keith; Wallace, Terryl A.; Clark, Ronald K.

    1992-01-01

    Mechanical properties of Beta-21S (Ti-15Mo-3Al-2.7Nb-0.2Si, wt percent) with glass, aluminide, and glass-on-aluminide coatings less than 3-micron thick were studied. Coatings were deposited by sol-gel processing or electron-beam evaporation onto 4.5-mil (113-micron) thick Beta-21S sheet from which, after oxidizing in air at 700 or 800 C, tensile test specimens were machined. Plastic elongation was the most severely degraded of the tensile properties; the glass-on-aluminide coatings were the most effective in preventing degradation. It was found that oxygen trapping by forming oxides in the coating, and reactions between the coatings and the Beta-21S alloy played significant roles.

  6. Fatigue-life behavior and matrix fatigue crack spacing in unnotched SCS-6/Timetal 21S metal matrix composites

    NASA Technical Reports Server (NTRS)

    Ward, G. T.; Herrmann, D. J.; Hillberry, B. M.

    1993-01-01

    Fatigue tests of the SCS-6/Timetal 21S composite system were performed to characterize the fatigue behavior for unnotched conditions. The stress-life behavior of the unnotched (9/90)2s laminates was investigated for stress ratios of R = 0.1 and R = 0.3. The occurrence of matrix cracking was also examined in these specimens. This revealed multiple matrix crack initiation sites throughout the composite, as well as evenly spaced surface cracks along the length of the specimens. No difference in fatigue lives were observed for stress ratios of R = 0.1 and R = 0.3 when compared on a stress range basis. The unnotched SCS-6/Timetal 21S composites had shorter fatigue lives than the SCS-6/Ti-15-3 composites, however the neat Timetal 21S matrix material had a longer fatigue life than the neat Ti-15-3.

  7. Fatigue-life behavior and matrix fatigue crack spacing in unnotched SCS-6/Timetal 21S metal matrix composites

    NASA Astrophysics Data System (ADS)

    Ward, G. T.; Herrmann, D. J.; Hillberry, B. M.

    1993-07-01

    Fatigue tests of the SCS-6/Timetal 21S composite system were performed to characterize the fatigue behavior for unnotched conditions. The stress-life behavior of the unnotched (9/90)2s laminates was investigated for stress ratios of R = 0.1 and R = 0.3. The occurrence of matrix cracking was also examined in these specimens. This revealed multiple matrix crack initiation sites throughout the composite, as well as evenly spaced surface cracks along the length of the specimens. No difference in fatigue lives were observed for stress ratios of R = 0.1 and R = 0.3 when compared on a stress range basis. The unnotched SCS-6/Timetal 21S composites had shorter fatigue lives than the SCS-6/Ti-15-3 composites, however the neat Timetal 21S matrix material had a longer fatigue life than the neat Ti-15-3.

  8. Fundamentals of phosphate transfer.

    PubMed

    Kirby, Anthony J; Nome, Faruk

    2015-07-21

    Historically, the chemistry of phosphate transfer-a class of reactions fundamental to the chemistry of Life-has been discussed almost exclusively in terms of the nucleophile and the leaving group. Reactivity always depends significantly on both factors; but recent results for reactions of phosphate triesters have shown that it can also depend strongly on the nature of the nonleaving or "spectator" groups. The extreme stabilities of fully ionised mono- and dialkyl phosphate esters can be seen as extensions of the same effect, with one or two triester OR groups replaced by O(-). Our chosen lead reaction is hydrolysis-phosphate transfer to water: because water is the medium in which biological chemistry takes place; because the half-life of a system in water is an accepted basic index of stability; and because the typical mechanisms of hydrolysis, with solvent H2O providing specific molecules to act as nucleophiles and as general acids or bases, are models for reactions involving better nucleophiles and stronger general species catalysts. Not least those available in enzyme active sites. Alkyl monoester dianions compete with alkyl diester monoanions for the slowest estimated rates of spontaneous hydrolysis. High stability at physiological pH is a vital factor in the biological roles of organic phosphates, but a significant limitation for experimental investigations. Almost all kinetic measurements of phosphate transfer reactions involving mono- and diesters have been followed by UV-visible spectroscopy using activated systems, conveniently compounds with good leaving groups. (A "good leaving group" OR* is electron-withdrawing, and can be displaced to generate an anion R*O(-) in water near pH 7.) Reactivities at normal temperatures of P-O-alkyl derivatives-better models for typical biological substrates-have typically had to be estimated: by extended extrapolation from linear free energy relationships, or from rate measurements at high temperatures. Calculation is free

  9. In vivo administration of the frog skin peptide frenatin 2.1S induces immunostimulatory phenotypes of mouse mononuclear cells.

    PubMed

    Pantic, Jelena M; Radosavljevic, Gordana D; Jovanovic, Ivan P; Arsenijevic, Nebojsa N; Conlon, J Michael; Lukic, Miodrag L

    2015-09-01

    Host-defense peptides secreted by epithelial cells exhibit cytotoxic and immunoregulatory effects in order to protect the organism against invading microorganisms. Antimicrobial peptides derived from frog skin display both immunostimulatory and immunosuppressive actions as demonstrated by in vitro cytokine production by macrophages. Frenatin 2.1S, first isolated from skin secretions of the frog, Sphaenorhynchus lacteus (Hylidae), enhances the in vitro production of pro-inflammatory IL-1β, TNF-α and IL-23 by mouse peritoneal cells. In order to test whether the immunostimulatory action of frenatin 2.1S may be reproduced in vivo, effects of intraperitoneal injections of this peptide on mononuclear cells in the peritoneum and spleen were determined 24h after administration. The data indicate that frenatin 2.1S enhances the activation state and homing capacity of Th1 type lymphocytes and NKT cells in the mouse peritoneal cavity, as evaluated by increased expression of early activation marker CD69 among T and NKT cells and chemokine receptor CXCR3 among T cells. Frenatin 2.1S significantly increases the percentage of (F4/80(+)CD11c(+)CD206(+)) pro-inflammatory M1 macrophages and enhances the expression of MHC class II molecules on F4/80(+)CD11c(+) macrophages in the mouse peritoneal cavity. Additionally, injection of frenatin 2.1S, in the presence or absence of lipopolysaccharide, increases the percentage of peritoneal B cells of the (CD19(+)CD11b(+)CD5(+)) B1a phenotype thus contributing to an inflammatory milieu. We suggest that the immunostimulatory effect of frenatin 2.1S may have therapeutic relevance in disease states, such as certain types of cancer, in which an enhanced inflammatory response may be beneficial. PMID:25861850

  10. Environmental effects on the isothermal and thermomechanical fatigue of SCS-6/TIMETAL 21S unidirectional composites

    SciTech Connect

    Rosenberger, A.H.; Nicholas, T.

    1997-12-31

    The effect of environment on the fatigue behavior of SCS-6/TIMETAL 21S [0]{sub 4} composites is examined through a comparison of fatigue lives and damage progression for tests performed in air and high-purity helium. Isothermal and thermomechanical tests were conducted at 650 C and 150 to 650 C, respectively. Out-of-phase thermomechanical fatigue (TMF) lives of specimens tested in the inert environment show a {times}2 increase in life. In-phase TMF lives in inert and air environments, which are governed primarily by fiber bundle strength and matrix stress relaxation, are comparable. Isothermal fatigue tests in the inert environment performed at 1.0 Hz show that at high stresses the life is not affected by the environment but at lower stresses a {times}3.5 increase in life is observed. Reducing the fatigue frequency to 0.01 Hz causes no change in life at low stresses in the inert condition as compared to the low-frequency air condition. At high stresses, the behavior is governed primarily by the statistics of fiber bundle strength. Life fraction models that consider time-dependent and cycle-dependent behavior as well as fiber- and matrix-dominated failure modes are used to correlate observed behavior in these experiments.

  11. Corrosion behavior of titanium alloy Beta-21S coated with diamond like carbon in Hank's solution

    NASA Astrophysics Data System (ADS)

    Mohan, L.; Anandan, C.; Grips, V. K. William

    2012-06-01

    Diamond like carbon (DLC) coatings posses high hardness and low friction coefficient and also biocompatible, hence, they are of interest for enhancing the wear and corrosion resistance of bio-implant materials. Beta stabilized titanium alloys are attractive for biomedical applications because of their high specific strength and low modulus. In this work Beta-21S alloy (Ti-15Mo-3Nb-3Al-0.2Si) was implanted with carbon ions by plasma immersion ion implantation using methane and hydrogen gas mixture followed by DLC deposition by plasma enhanced chemical vapour deposition (PECVD). The implanted layers enabled deposition of adherent diamond-like carbon coatings on the titanium alloy which was otherwise not possible. The corrosion behavior of the treated and untreated samples was investigated through electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization studies in simulated body fluid (Hank's solution). XPS, micro Raman and EDAX investigation of the samples showed the formation of a thin oxide layer on the treated samples after corrosion experiments. Corrosion resistance of the DLC coated sample is comparable with that of the untreated samples. Electrochemical impedance data of the substrate and implanted samples were fitted with two time constant equivalent circuits and that of DLC coated samples with two-layer model.

  12. Infrared transient-liquid-phase joining of SCS-6/{beta}21S titanium matrix composite

    SciTech Connect

    Blue, C.A.; Sikka, V.K.; Blue, R.A.; Lin, R.Y.

    1996-02-01

    Fiber-reinforced titanium matrix composites (TMCs) are among the advanced materials being considered for use in the aerospace industry due to their light weight, high strength, and high modulus. A rapid infrared joining process has been developed for the joining of composites and advanced materials. Rapid infrared joining has been shown not to have many of the problems associated with conventional joining methods. Two models were utilized to predict the joint evolution and fiber reaction zone growth. TMC, 16-ply SCS-6/{beta}21S, has been successfully joined with total processing times of under 2 min utilizing the rapid infrared joining technique. The process utilizes a 50 C/sec ramping rate, 17-{micro}m Ti-15Cu-15Ni wt % filler material between the faying surfaces; a joining temperature of 1,100 C; and 120 sec of time to join the composite material. Joint shear strength testing of the rapid infrared joints at temperatures as high as 800 C has revealed no joint failures. Also, due to the rapid cooling of the process, no poststabilization of the matrix material is necessary to prevent the formation of a brittle omega phase during subsequent use of the TMC at intermediate temperatures, 270 to 430 C, for up to 20 h.

  13. 21 CFR 184.1434 - Magnesium phosphate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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 both magnesium phosphate, dibasic, and magnesium phosphate, tribasic. Magnesium phosphate, dibasic...

  14. Biomediated continuous release phosphate fertilizer

    DOEpatents

    Goldstein, A.H.; Rogers, R.D.

    1999-06-15

    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. 13 figs.

  15. Biomediated continuous release phosphate fertilizer

    SciTech Connect

    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.

  16. Dysregulation of phosphate metabolism and conditions associated with phosphate toxicity.

    PubMed

    Brown, Ronald B; Razzaque, Mohammed S

    2015-01-01

    Phosphate homeostasis is coordinated and regulated by complex cross-organ talk through delicate hormonal networks. Parathyroid hormone (PTH), secreted in response to low serum calcium, has an important role in maintaining phosphate homeostasis by influencing renal synthesis of 1,25-dihydroxyvitamin D, thereby increasing intestinal phosphate absorption. Moreover, PTH can increase phosphate efflux from bone and contribute to renal phosphate homeostasis through phosphaturic effects. In addition, PTH can induce skeletal synthesis of another potent phosphaturic hormone, fibroblast growth factor 23 (FGF23), which is able to inhibit renal tubular phosphate reabsorption, thereby increasing urinary phosphate excretion. FGF23 can also fine-tune vitamin D homeostasis by suppressing renal expression of 1-alpha hydroxylase (1α(OH)ase). This review briefly discusses how FGF23, by forming a bone-kidney axis, regulates phosphate homeostasis, and how its dysregulation can lead to phosphate toxicity that induces widespread tissue injury. We also provide evidence to explain how phosphate toxicity related to dietary phosphorus overload may facilitate incidence of noncommunicable diseases including kidney disease, cardiovascular disease, cancers and skeletal disorders. PMID:26131357

  17. Dysregulation of phosphate metabolism and conditions associated with phosphate toxicity

    PubMed Central

    Brown, Ronald B; Razzaque, Mohammed S

    2015-01-01

    Phosphate homeostasis is coordinated and regulated by complex cross-organ talk through delicate hormonal networks. Parathyroid hormone (PTH), secreted in response to low serum calcium, has an important role in maintaining phosphate homeostasis by influencing renal synthesis of 1,25-dihydroxyvitamin D, thereby increasing intestinal phosphate absorption. Moreover, PTH can increase phosphate efflux from bone and contribute to renal phosphate homeostasis through phosphaturic effects. In addition, PTH can induce skeletal synthesis of another potent phosphaturic hormone, fibroblast growth factor 23 (FGF23), which is able to inhibit renal tubular phosphate reabsorption, thereby increasing urinary phosphate excretion. FGF23 can also fine-tune vitamin D homeostasis by suppressing renal expression of 1-alpha hydroxylase (1α(OH)ase). This review briefly discusses how FGF23, by forming a bone–kidney axis, regulates phosphate homeostasis, and how its dysregulation can lead to phosphate toxicity that induces widespread tissue injury. We also provide evidence to explain how phosphate toxicity related to dietary phosphorus overload may facilitate incidence of noncommunicable diseases including kidney disease, cardiovascular disease, cancers and skeletal disorders. PMID:26131357

  18. Total Structure Determination of Au21(S-Adm)15 and Geometrical/Electronic Structure Evolution of Thiolated Gold Nanoclusters.

    PubMed

    Chen, Shuang; Xiong, Lin; Wang, Shuxin; Ma, Zhongyun; Jin, Shan; Sheng, Hongting; Pei, Yong; Zhu, Manzhou

    2016-08-31

    The larger size gold nanoparticles typically adopt a face-centered cubic (fcc) atomic packing, while in the ultrasmall nanoclusters the packing styles of Au atoms are diverse, including fcc, hexagonal close packing (hcp), and body-centered cubic (bcc), depending on the ligand protection. The possible conversion between these packing structures is largely unknown. Herein, we report the growth of a new Au21(S-Adm)15 nanocluster (S-Adm = adamantanethiolate) from Au18(SR)14 (SR = cyclohexylthiol), with the total structure determined by X-ray crystallography. It is discovered that the hcp Au9-core in Au18(SR)14 is transformed to a fcc Au10-core in Au21(S-Adm)15. Combining with density functional theory (DFT) calculations, we provide critical information about the growth mechanism (geometrical and electronic structure) and the origin of fcc-structure formation for the thiolate-protected gold nanoclusters. PMID:27552520

  19. Phosphonomethyl analogues of hexose phosphates.

    PubMed

    Webster, D; Jondorf, W R; Dixon, H B

    1976-05-01

    The analogue of fructose 1,6-bisphosphate in which the phosphate group, -O-PO3H2, on C-6 is replaced by the phosphonomethyl group, -CH2-PO3H2, was made enzymically from the corresponding analogue of 3-phosphoglycerate. It was a substrate for aldolase, which was used to form it, but not for fructose 1,6-bisphosphatase. It was hydrolysed chemically to yield the corresponding analogue of fructose 6-phosphate [i.e. 6-deoxy-6-(phosphonomethyl)-D-fructose, or, more strictly, 6,7-dideoxy-7-phosphono-D-arabino-2-heptulose]. This proved to be a substrate for the sequential actions of glucose 6-phosphate isomerase, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. Thus seven out of the nine enzymes of the glycolytic and pentose phosphate pathways so far tested catalyse the reactions of the phosphonomethyl isosteres of their substrates. PMID:7247

  20. Sphingosine 1-phosphate signalling.

    PubMed

    Mendelson, Karen; Evans, Todd; Hla, Timothy

    2014-01-01

    Sphingosine 1-phosphate (S1P) is a lipid mediator formed by the metabolism of sphingomyelin. In vertebrates, S1P is secreted into the extracellular environment and signals via G protein-coupled S1P receptors to regulate cell-cell and cell-matrix adhesion, and thereby influence cell migration, differentiation and survival. The expression and localization of S1P receptors is dynamically regulated and controls vascular development, vessel stability and immune cell trafficking. In addition, crucial events during embryogenesis, such as angiogenesis, cardiogenesis, limb development and neurogenesis, are regulated by S1P signalling. Here, and in the accompanying poster, we provide an overview of S1P signalling in development and in disease. PMID:24346695

  1. Templated, layered manganese phosphate

    DOEpatents

    Thoma, Steven G.; Bonhomme, Francois R.

    2004-08-17

    A new crystalline maganese phosphate composition having an empirical formula: O). The compound was determined to crystallize in the trigonal space group P-3c1 with a=8.8706(4) .ANG., c=26.1580(2) .ANG., and V (volume)=1783 .ANG..sup.3. The structure consists of sheets of corner sharing Mn(II)O.sub.4 and PO.sub.4 tetrahedra with layers of (H.sub.3 NCH.sub.2 CH.sub.2).sub.3 N and water molecules in-between. The pronated (H.sub.3 NCH.sub.2 CH.sub.2).sub.3 N molecules provide charge balancing for the inorganic sheets. A network of hydrogen bonds between water molecules and the inorganic sheets holds the structure together.

  2. Light weight phosphate cements

    DOEpatents

    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.

  3. 21 CFR 520.823 - Erythromycin phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... (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...

  4. 21 CFR 520.823 - Erythromycin phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... (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...

  5. Chemoenzymatic synthesis of polyprenyl phosphates.

    PubMed

    Hartley, Meredith D; Larkin, Angelyn; Imperiali, Barbara

    2008-05-01

    Polyprenyl phosphates, including undecaprenyl phosphate and dolichyl phosphate, are essential intermediates in several important biochemical pathways including N-linked protein glycosylation in eukaryotes and prokaryotes and prokaryotic cell wall biosynthesis. Herein, we describe the evaluation of three potential undecaprenol kinases as agents for the chemoenzymatic synthesis of polyprenyl phosphates. Target enzymes were expressed in crude cell envelope fractions and quantified via the use of luminescent lanthanide-binding tags (LBTs). The Streptococcus mutans diacylglycerol kinase (DGK) was shown to be a very useful agent for polyprenol phosphorylation using ATP as the phosphoryl transfer agent. In addition, the S. mutans DGK can be coupled with two Campylobacter jejuni glycosyltransferases involved in N-linked glycosylation to efficiently biosynthesize the undecaprenyl pyrophosphate-linked disaccharide needed for studies of PglB, the C. jejuni oligosaccharyl transferase. PMID:18374576

  6. SOURCE ASSESSMENT: PHOSPHATE FERTILIZER INDUSTRY

    EPA Science Inventory

    The report describes a study of air emissions, water effluents, and solid residues resulting from the manufacture of phosphate fertilizers. It includes the production of wet process phosphoric acid, superphosphoric acid, normal superphosphate, triple superphosphate, and ammonium ...

  7. 21 CFR 184.1301 - Ferric phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ferric chloride or ferric citrate. (b) The ingredient meets the specifications of the Food Chemicals... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ferric phosphate. 184.1301 Section 184.1301 Food... GRAS § 184.1301 Ferric phosphate. (a) Ferric phosphate (ferric orthophosphate, iron (III) phosphate,...

  8. 21 CFR 184.1301 - Ferric phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... reaction of sodium phosphate with ferric chloride or ferric citrate. (b) The ingredient meets the... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ferric phosphate. 184.1301 Section 184.1301 Food... Specific Substances Affirmed as GRAS § 184.1301 Ferric phosphate. (a) Ferric phosphate...

  9. 21 CFR 184.1301 - Ferric phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... reaction of sodium phosphate with ferric chloride or ferric citrate. (b) The ingredient meets the... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ferric phosphate. 184.1301 Section 184.1301 Food... Specific Substances Affirmed as GRAS § 184.1301 Ferric phosphate. (a) Ferric phosphate...

  10. 21 CFR 520.823 - Erythromycin phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Erythromycin phosphate. 520.823 Section 520.823... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.823 Erythromycin phosphate. (a) Specifications. Erythromycin phosphate is the phosphate salt of the antibiotic substance...

  11. 21 CFR 520.823 - Erythromycin phosphate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Erythromycin phosphate. 520.823 Section 520.823... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.823 Erythromycin phosphate. (a) Specifications. Erythromycin phosphate is the phosphate salt of the antibiotic substance...

  12. Responses to phosphate deprivation in yeast cells.

    PubMed

    Yadav, Kamlesh Kumar; Singh, Neelima; Rajasekharan, Ram

    2016-05-01

    Inorganic phosphate is an essential nutrient because it is required for the biosynthesis of nucleotides, phospholipids and metabolites in energy metabolism. During phosphate starvation, phosphatases play a major role in phosphate acquisition by hydrolyzing phosphorylated macromolecules. In Saccharomyces cerevisiae, PHM8 (YER037W), a lysophosphatidic acid phosphatase, plays an important role in phosphate acquisition by hydrolyzing lysophosphatidic acid and nucleotide monophosphate that results in accumulation of triacylglycerol and nucleotides under phosphate limiting conditions. Under phosphate limiting conditions, it is transcriptionally regulated by Pho4p, a phosphate-responsive transcription factor. In this review, we focus on triacylglycerol metabolism in transcription factors deletion mutants involved in phosphate metabolism and propose a link between phosphate and triacylglycerol metabolism. Deletion of these transcription factors results in an increase in triacylglycerol level. Based on these observations, we suggest that PHM8 is responsible for the increase in triacylglycerol in phosphate metabolising gene deletion mutants. PMID:26615590

  13. Biphasic calcium phosphate in periapical surgery

    PubMed Central

    Suneelkumar, Chinni; Datta, Krithika; Srinivasan, Manali R; Kumar, Sampath T

    2008-01-01

    Calcium phosphate ceramics like hydroxyapatite and β -tricalcium phosphate (β -TCP) possess mineral composition that closely resembles that of the bone. They can be good bone substitutes due to their excellent biocompatibility. Biphasic calcium phosphate is a bone substitute which is a mixture of hydroxyapatite and β -tricalcium phosphate in fixed ratios. Studies have demonstrated the osteoconductive potential of this composition. This paper highlights the clinical use of biphasic calcium phosphate as a bone substitute in periapical surgery. PMID:20142892

  14. Prediction of stress-strain response of SCS-6/Timetal-21S subjected to a hypersonic flight profile

    NASA Technical Reports Server (NTRS)

    Mirdamadi, Massoud; Johnson, W. Steven

    1994-01-01

    Thermomechanical response of a cross-ply SCS-6/Timetal-21S composite subjected to a generic hypersonic flight profile with the temperature ranging from -130 C to 816 C was evaluated experimentally and analytically. A two dimensional micromechanical anlaysis, VISCOPLY, was used to predict the stress-strain response of the laminate and of the constituents in each ply during thermomechanical loading conditions. In the analysis, the fiber was modeled as elastic with transverse orthotropic and temperature dependent properties and the matrix was modeled using a thermoviscoplastic constitutive relation. The fiber transverse modulus was reduced in the analysis to simulate fiber-matrix interface failure. Reasonable agreement was found between measured and predicted laminate stress-strain response when fiber-matrix debonding was modeled.

  15. Uranium phosphate biomineralization by fungi.

    PubMed

    Liang, Xinjin; Hillier, Stephen; Pendlowski, Helen; Gray, Nia; Ceci, Andrea; Gadd, Geoffrey Michael

    2015-06-01

    Geoactive soil fungi were investigated for phosphatase-mediated uranium precipitation during growth on an organic phosphorus source. Aspergillus niger and Paecilomyces javanicus were grown on modified Czapek-Dox medium amended with glycerol 2-phosphate (G2P) as sole P source and uranium nitrate. Both organisms showed reduced growth on uranium-containing media but were able to extensively precipitate uranium and phosphorus-containing minerals on hyphal surfaces, and these were identified by X-ray powder diffraction as uranyl phosphate species, including potassium uranyl phosphate hydrate (KPUO6 .3H2 O), meta-ankoleite [(K1.7 Ba0.2 )(UO2 )2 (PO4 )2 .6H2 O], uranyl phosphate hydrate [(UO2 )3 (PO4 )2 .4H2 O], meta-ankoleite (K(UO2 )(PO4 ).3H2 O), uramphite (NH4 UO2 PO4 .3H2 O) and chernikovite [(H3 O)2 (UO2 )2 (PO4 )2 .6H2 O]. Some minerals with a morphology similar to bacterial hydrogen uranyl phosphate were detected on A. niger biomass. Geochemical modelling confirmed the complexity of uranium speciation, and the presence of meta-ankoleite, uramphite and uranyl phosphate hydrate between pH 3 and 8 closely matched the experimental data, with potassium as the dominant cation. We have therefore demonstrated that fungi can precipitate U-containing phosphate biominerals when grown with an organic source of P, with the hyphal matrix serving to localize the resultant uranium minerals. The findings throw further light on potential fungal roles in U and P biogeochemistry as well as the application of these mechanisms for element recovery or bioremediation. PMID:25580878

  16. Clinical evaluation of GEM 21S® and a collagen membrane with a coronally advanced flap as a root coverage procedure in the treatment of gingival recession defects: A comparative study

    PubMed Central

    Singh, Preetinder; Suresh, D. K.

    2012-01-01

    Aim: Clinical evaluation of efficacy of rhPDGF-BB plus beta tricalcium phosphate (GEM 21S®) along with a collagen membrane in root coverage using a coronally advanced flap. Materials and Methods: This human case series evaluated the clinical outcome of rhPDGF-BB with beta-tricalcium phosphate (GEM 21S®) and a collagen membrane in the treatment of recession defects using a coronally advanced flap. Patients were followed postoperatively, and healing was evaluated at 1, 3, and 6 months, with recession depth as the primary outcome measure. Results: This pioneer case series revealed a favorable tissue response to GEM 21S® and collagen membrane from both clinical and esthetic point of view in regenerative periodontal surgery. PMID:23493720

  17. Uranium endowments in phosphate rock.

    PubMed

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

    2014-04-15

    This study seeks to identify and specify the components that make up the prospects of U recovery from phosphate rock. A systems approach is taken. The assessment includes i) reviewing past recovery experience and lessons learned; ii) identifying factors that determine recovery; and iii) establishing a contemporary evaluation of U endowments in phosphate rock reserves, as well as the available and recoverable amounts from phosphate rock and phosphoric acid production. We find that in the past, recovery did not fulfill its potential and that the breakup of the Soviet Union worsened then-favorable recovery market conditions in the 1990s. We find that an estimated 5.7 million tU may be recoverable from phosphate rock reserves. In 2010, the recoverable tU from phosphate rock and phosphoric acid production may have been 15,000 tU and 11,000 tU, respectively. This could have filled the world U supply-demand gap for nuclear energy production. The results suggest that the U.S., Morocco, Tunisia, and Russia would be particularly well-suited to recover U, taking infrastructural considerations into account. We demonstrate future research needs, as well as sustainability orientations. We conclude that in order to promote investment and production, it seems necessary to establish long-term contracts at guaranteed prices, ensuring profitability for phosphoric acid producers. PMID:24556272

  18. Detergent phosphate bans and eutrophication

    SciTech Connect

    Lee, G.F.; Jones, R.A.

    1986-04-01

    The Vollenweider-OECD eutrophication model has been expanded to approximately 400 lakes. It is possible to make a quantitative prediction of the effects of a detergent phosphate ban and thereby to ascertain the potential benefits of such a ban. In order to assess the effect of a detergent phosphate ban on water quality it is necessary to know the percentage of phosphorus in the domestic waste water that enters the water body, either directly or indirectly, and the percentage of the total phosphorus load that is derived from domestic wastewater. Although detergent phosphate bans generally will not result in an overall improvement to water quality, there may be some situations in which eutrophication-related water quality would be improved by a ban. 8 references, 1 figure, 1 table.

  19. [Phosphate metabolism and iron deficiency].

    PubMed

    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. PMID:26813504

  20. Genetics Home Reference: glucose phosphate isomerase deficiency

    MedlinePlus

    ... Me Understand Genetics Home Health Conditions GPI deficiency glucose phosphate isomerase deficiency Enable Javascript to view the ... boxes. Download PDF Open All Close All Description Glucose phosphate isomerase (GPI) deficiency is an inherited disorder ...

  1. Phosphate bonding to goethite and pyrolusite surfaces

    USGS Publications Warehouse

    Weiner, Eugene R.; Goldberg, M.C.; Boymel, P.M.

    1984-01-01

    Fourier transform infrared (FTIR) spectra were obtained from pure and phosphated goethite (??-FeOOH), and pyrolusite (MnO2). The nature of the phosphate-surface bond was determined to be binuclear for goethite and bidentate for pyrolusite.

  2. Long-Sought Vacuolar Phosphate Transporters Identified.

    PubMed

    Bucher, Marcel; Fabiańska, Izabela

    2016-06-01

    The vacuole is an important subcellular compartment that serves as main phosphate storage in plants among other functions. Three recent studies shed light on the underlying molecular mechanisms for vacuolar phosphate transport that had long remained unknown. PMID:27160805

  3. 21 CFR 184.1301 - Ferric phosphate.

    Code of Federal Regulations, 2010 CFR

    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...

  4. 21 CFR 184.1301 - Ferric phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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...

  5. In-Vitro Biocompatibility Studies of Plasma-Nitrided Titanium Alloy β-21S Using Fibroblast Cells

    NASA Astrophysics Data System (ADS)

    Mohan, L.; Raja, M. D.; Uma, T. S.; Rajendran, N.; Anandan, C.

    2016-04-01

    In the present work, titanium alloy β-21S was nitrided in a low-pressure RF plasma with 100% nitrogen and 20% hydrogen-diluted nitrogen at 800 °C for 4 h and the samples were evaluated for in-vitro biocompatibility by using NIH 3T3 fibroblast cell line. Cellular behavior was evaluated in terms of cell morphology and its viability. FESEM was exploited to observe the morphology of the cells fixed over the surface of the implant. Fibroblasts were seemed to be well distributed over the surface with its characteristic spindle-like shape. Over all, the results indicate that nitriding provided a compatible surface for cell attachment and cell growth. Cell viability and proliferation was assessed by using standard MTT assay. Compared with substrate, the nitrided samples exhibited high-percentage cell viability demonstrating their increased biocompatibility. In addition, the nitrided samples facilitate bone-like apatite formation and exhibited a gradual increase of apatite formation after immersion in Hanks' solution.

  6. Effect of gas composition on corrosion behavior and growth of apatite on plasma nitrided titanium alloy Beta-21S

    NASA Astrophysics Data System (ADS)

    Mohan, L.; Anandan, C.

    2013-03-01

    Titanium alloy beta 21S with composition Ti-15Mo-3Nb-3Al-0.2Si was plasma nitrided using inductively coupled RF Plasma with 100% N2 and 80% N2-20% H2 at 800 °C for 4 h. XRD and micro Raman studies show the formation of titanium nitrides. Potentiodynamic polarization studies in Hank's solution show the corrosion resistance of the 80-20% (N2-H2) treated samples to be better than the 100% N2 treated samples. However, untreated samples show better corrosion resistance than the treated samples. Electrochemical impedance spectroscopy (EIS) studies show higher charge transfer resistance and lower double layer capacitance for the substrate compared to the nitrided samples. FESEM images of samples immersed in SBF show that growth of apatite is more and the size of deposits are larger on nitrided samples, especially on those nitrided with hydrogen dilution, as compared to that on the untreated substrate. EDS results show a decrease in nitrogen content and increase in oxygen content after corrosion experiments. XPS spectra from the nitrided and corrosion tested samples show the presence of oxide, nitride and oxynitride on the surface and after corrosion studies the samples are covered with oxide. Nitrided samples immersed in Hank's solution for one day show higher amount of calcium, phosphorous and oxygen in hydroxide form than the substrate.

  7. 21 CFR 582.5434 - Magnesium phosphate.

    Code of Federal Regulations, 2010 CFR

    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)....

  8. 21 CFR 182.6290 - Disodium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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...

  9. 21 CFR 182.6285 - Dipotassium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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...

  10. 21 CFR 582.1217 - Calcium phosphate.

    Code of Federal Regulations, 2010 CFR

    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)....

  11. 21 CFR 182.1217 - Calcium phosphate.

    Code of Federal Regulations, 2010 CFR

    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)....

  12. 21 CFR 582.6285 - Dipotassium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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...

  13. 21 CFR 582.1217 - Calcium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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)....

  14. 21 CFR 182.6290 - Disodium phosphate.

    Code of Federal Regulations, 2010 CFR

    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...

  15. 21 CFR 582.6290 - Disodium phosphate.

    Code of Federal Regulations, 2010 CFR

    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...

  16. 21 CFR 582.5434 - Magnesium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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)....

  17. 40 CFR 721.5995 - Polyalkyl phosphate.

    Code of Federal Regulations, 2010 CFR

    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)...

  18. 21 CFR 582.6285 - Dipotassium phosphate.

    Code of Federal Regulations, 2010 CFR

    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...

  19. 21 CFR 182.6285 - Dipotassium phosphate.

    Code of Federal Regulations, 2010 CFR

    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...

  20. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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)...

  1. 21 CFR 582.6290 - Disodium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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...

  2. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2010 CFR

    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)...

  3. 21 CFR 182.1217 - Calcium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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)....

  4. Urea phosphate as granular or fluid fertilizers

    SciTech Connect

    Blouin, G.M.

    1984-01-01

    Studies are being conducted of the production and agronomic characteristics of the phosphoric acid-urea adduct, urea phosphate, and of the various granular and fluid fertilizers that can be produced from it. Flowsheets are given for the production of urea phosphate. Characteristics of unpurified and purified urea phosphate are also given. (DLC)

  5. 21 CFR 182.8217 - Calcium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium phosphate. 182.8217 Section 182.8217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8217 Calcium phosphate. (a) Product. Calcium phosphate...

  6. 21 CFR 182.8778 - Sodium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium phosphate. 182.8778 Section 182.8778 Food... HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  7. 21 CFR 582.5778 - Sodium phosphate.

    Code of Federal Regulations, 2010 CFR

    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)....

  8. 21 CFR 582.1778 - Sodium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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)....

  9. 21 CFR 582.6778 - Sodium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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....

  10. 21 CFR 182.6778 - Sodium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium phosphate. 182.6778 Section 182.6778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 1 § 182.6778 Sodium phosphate. (a) Product. Sodium phosphate...

  11. 21 CFR 582.5778 - Sodium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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)....

  12. 21 CFR 182.1778 - Sodium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium phosphate. 182.1778 Section 182.1778 Food... GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This substance is...

  13. 21 CFR 182.1778 - Sodium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 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)....

  14. 21 CFR 582.6778 - Sodium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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....

  15. 21 CFR 182.1778 - Sodium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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)....

  16. 21 CFR 182.8778 - Sodium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium phosphate. 182.8778 Section 182.8778 Food... HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  17. 21 CFR 582.5778 - Sodium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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)....

  18. 21 CFR 182.8778 - Sodium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium phosphate. 182.8778 Section 182.8778 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8778 Sodium phosphate. (a) Product. Sodium phosphate (mono-,...

  19. 21 CFR 582.1778 - Sodium phosphate.

    Code of Federal Regulations, 2010 CFR

    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)....

  20. 21 CFR 182.6778 - Sodium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium phosphate. 182.6778 Section 182.6778 Food... HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 1 § 182.6778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  1. 21 CFR 582.6778 - Sodium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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....

  2. 21 CFR 182.6778 - Sodium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium phosphate. 182.6778 Section 182.6778 Food... HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 1 § 182.6778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  3. 21 CFR 182.1778 - Sodium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 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)....

  4. 21 CFR 582.6778 - Sodium phosphate.

    Code of Federal Regulations, 2010 CFR

    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....

  5. 21 CFR 182.8778 - Sodium phosphate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium phosphate. 182.8778 Section 182.8778 Food... HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  6. 21 CFR 182.8778 - Sodium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium phosphate. 182.8778 Section 182.8778 Food... HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  7. 21 CFR 582.6778 - Sodium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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....

  8. 21 CFR 182.1778 - Sodium phosphate.

    Code of Federal Regulations, 2010 CFR

    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)....

  9. 21 CFR 582.1778 - Sodium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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)....

  10. 21 CFR 182.6778 - Sodium phosphate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium phosphate. 182.6778 Section 182.6778 Food... HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 1 § 182.6778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  11. 21 CFR 182.6778 - Sodium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium phosphate. 182.6778 Section 182.6778 Food... HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 1 § 182.6778 Sodium phosphate. (a) Product. Sodium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  12. 21 CFR 582.1778 - Sodium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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)....

  13. 21 CFR 582.5778 - Sodium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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)....

  14. 21 CFR 582.1778 - Sodium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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)....

  15. 21 CFR 582.5778 - Sodium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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)....

  16. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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)...

  17. 21 CFR 182.1217 - Calcium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 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)....

  18. 21 CFR 182.6285 - Dipotassium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Dipotassium phosphate. 182.6285 Section 182.6285...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 1 § 182.6285 Dipotassium phosphate. (a) Product. Dipotassium phosphate. (b) Conditions of use. This substance is generally recognized as safe when used...

  19. 21 CFR 582.1217 - Calcium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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)....

  20. 21 CFR 582.6285 - Dipotassium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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...

  1. 21 CFR 582.1217 - Calcium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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)....

  2. 21 CFR 582.1217 - Calcium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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)....

  3. 21 CFR 182.6290 - Disodium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 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...

  4. 21 CFR 582.5434 - Magnesium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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)....

  5. 21 CFR 182.6290 - Disodium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 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...

  6. 21 CFR 582.6285 - Dipotassium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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...

  7. 21 CFR 582.5434 - Magnesium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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)....

  8. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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)...

  9. 21 CFR 182.6285 - Dipotassium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 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...

  10. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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 582.6285 - Dipotassium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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...

  12. 21 CFR 582.6290 - Disodium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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 582.6290 - Disodium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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...

  14. 21 CFR 582.5434 - Magnesium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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 182.1217 - Calcium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium phosphate. 182.1217 Section 182.1217 Food... GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1217 Calcium phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This substance is...

  16. 21 CFR 182.1217 - Calcium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 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)....

  17. 21 CFR 182.6285 - Dipotassium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 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...

  18. 21 CFR 582.6290 - Disodium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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...

  19. Phosphatidylinositol 4-phosphate and phosphatidylinositol 3-phosphate regulate phagolysosome biogenesis

    PubMed Central

    Jeschke, Andreas; Zehethofer, Nicole; Lindner, Buko; Krupp, Jessica; Schwudke, Dominik; Haneburger, Ina; Jovic, Marko; Backer, Jonathan M.; Balla, Tamas; Hilbi, Hubert; Haas, Albert

    2015-01-01

    Professional phagocytic cells ingest microbial intruders by engulfing them into phagosomes, which subsequently mature into microbicidal phagolysosomes. Phagosome maturation requires sequential fusion of the phagosome with early endosomes, late endosomes, and lysosomes. Although various phosphoinositides (PIPs) have been detected on phagosomes, it remained unclear which PIPs actually govern phagosome maturation. Here, we analyzed the involvement of PIPs in fusion of phagosomes with various endocytic compartments and identified phosphatidylinositol 4-phosphate [PI(4)P], phosphatidylinositol 3-phosphate [PI(3)P], and the lipid kinases that generate these PIPs, as mediators of phagosome–lysosome fusion. Phagosome–early endosome fusion required PI(3)P, yet did not depend on PI(4)P. Thus, PI(3)P regulates phagosome maturation at early and late stages, whereas PI(4)P is selectively required late in the pathway. PMID:25825728

  20. Thermomechanical Fatigue Damage/Failure Mechanisms in SCS-6/Timetal 21S [0/90](Sub S) Composite

    NASA Technical Reports Server (NTRS)

    Castelli, Michael G.

    1994-01-01

    The thermomechanical fatigue (TMF) deformation, damage, and life behaviors of SCS6/Timetal 21S (0/90)s were investigated under zero-tension conditions. In-phase (IP) and out-of-phase (OP) loadings were investigated with a temperature cycle from 150 to 650 deg C. An advanced TMF test technique was used to quantify mechanically damage progression. The technique incorporated explicit measurements of the macroscopic (1) isothermal static moduli at the temperature extremes of the TMF cycle and (2) coefficient of thermal expansion (CTE) as functions of the TMF cycles. The importance of thermal property degradation and its relevance to accurate post-test data analysis and interpretation is briefly addressed. Extensive fractography and metallography were conducted on specimens from failed and interrupted tests to characterize the extent of damage at the microstructure level. Fatigue life results indicated trends analogous to those established for similar unidirectional(0) reinforced titanium matrix composite systems. High stress IP and mid to low stress OP loading conditions were life-limiting in comparison to maximum temperature isothermal conditions. Dominant damage mechanisms changed with cycle type. Damage resulting from IP TMF conditions produced measurable decreases in static moduli but only minimal changes in the CTE. Metallography on interrupted and failed specimens revealed extensive (0) fiber cracking with sparse matrix damage. No surface initiated matrix cracks were present. Comparable OP TMF conditions initiated environment enhanced surface cracking and matrix cracking initiated at (90) fiber/matrix (F/M) interfaces. Notable static moduli and CTE degradations were measured. Fractography and metallography revealed that the transverse cracks originating from the surface and (90) F/M interfaces tended to converge and coalesce at the (0) fibers.

  1. Impact damage resistance and residual property assessment of (0/+/-45/90)s SCS-6/Timetal 21S

    NASA Technical Reports Server (NTRS)

    Miller, Jennifer L.; Portanova, Marc A.; Johnson, W. Steven

    1995-01-01

    The impact damage resistance and residual mechanical properties of (0/ +/- 45/90)s SCS-6/Timetal 21S composites were evaluated. Both quasi-static indentation and drop-weight impact tests were used to investigate the impact behavior at two nominal energy levels (5.5 and 8.4 J) and determine the onset of internal damage. Through x-ray inspection, the extent of internal damage was characterized non-destructively. The composite strength and constant amplitude fatigue response were evaluated to assess the effects of the sustained damage. Scanning electron microscopy was used to characterize internal damage from impact in comparison to damage that occurs during mechanical loading alone. The effect of stacking sequence was examined by using specimens with the long dimension of the specimen both parallel (longitudinal) and perpendicular (transverse) to the 0 deg fiber direction. Damage in the form of longitudinal and transverse cracking occurred in all longitudinal specimens tested at energies greater than 6.3 J. Similar results occurred in the transverse specimens tested above 5.4 J. Initial load drop, characteristic of the onset of damage, occurred on average at 6.3 J in longitudinal specimens and at 5.0 J in transverse specimens. X-ray analysis showed broken fibers in the impacted region in specimens tested at the higher impact energies. At low impact energies, visible matrix cracking may occur, but broken fibers may not. Matrix cracking was noted along fiber swims and it appeared to depend on the surface quality of composite. At low impact energies, little damage has been incurred by the composite and the residual strength and residual life is not greatly reduced as compared to an undamaged composite. At higher impact energies, more damage occurred and a greater effect of the impact damage was observed.

  2. Impact damage resistance and residual property assessment of [0/{+-}45/90]{sub s} SCS-6/TIMETAL 21S

    SciTech Connect

    Miller, J.L.; Portanova, M.A.; Johnson, W.S.

    1997-12-31

    Titanium-matrix composites (TMCs) are candidate materials for high-temperature structural applications, such as gas turbine engines, where their high specific strength at elevated temperatures and good general corrosion resistance are beneficial. Here, the impact damage resistance and residual mechanical properties of [0/{+-}45/90]{sub s} SCS-6/TIMETAL 21S composites were evaluated.Both quasi-static indentation and drop-weight impact tests were used to investigate the impact behavior at two nominal energy levels and to determine the onset of internal damage. Through X-ray inspection, the extent of internal damage was characterized nondestructively. The composite strength and constant-amplitude fatigue response were evaluated to assess the effects of the sustained damage. SEM was used to characterize internal damage from impact in comparison to damage that occurs during mechanical loading alone. The effect of stacking sequence was examined by using specimens with the long dimension of the specimen both parallel and perpendicular to the 0{degree} fiber direction. Damage in the form of longitudinal and transverse cracking occurred in all longitudinal specimens tested at energies greater than 6.3 J. Similar results occurred in the transverse specimens tested above 5.4 J. Initial load drop, characteristic of the onset of damage, occurred on average at 6.3 J in longitudinal specimens and at 5.0 J in transverse specimens. X-ray analysis showed broken fibers in the impacted region in specimens tested at the higher impact energies. At low impact energies, visible matrix cracking may occur, but broken fibers may not. Matrix cracking was noted along fiber swims, and it appeared to depend on the surface quality of the composite. At low impact energies, little damage had been incurred by the composite and the residual strength and residual life was not greatly reduced as compared to an undamaged composite.

  3. Characterization of Damage Progression in SCS-6/timetal 21S (0)4 Under Thermomechanical Fatigue Loadings

    NASA Technical Reports Server (NTRS)

    Castelli, Michael G.

    1994-01-01

    A detailed experimental investigation was performed at a single maximum cyclic stress (sigma max) level to physically characterize the progression of thermomechanical fatigue (lW) damage in continuously reinforced (0 deg) SCS-6/Timetal 21S, a titanium matrix composite. In-phase (IP) and out of-phase (OP) loadings were investigated at sigma max = 1000 MPa with a temperature cycle from 150 to 6500 C. Damage progression, in terms of macroscopic property degradation, was experimentally quantified through an advanced TMF test methodology which incorporates explicit measurements of the isothermal static moduli at the TMF temperature extremes and the coefficient of thermal expansion (CTE) as functions of the TMF cycles. Detailed characterization of the physical damage progression at the microstructural level was performed by interrupting multiple TMF tests at various stages of mechanical property degradation and analyzing the microstructure through extensive destructive metallography. Further, the extent of damage was also quantified through residual static strength measurements. Results indicated that damage initiation occurred very early in cyclic life (N less than 0.1Nf) for both the IP and OP TMF loadings. IP TMF damage was found to be dominated by fiber breakage with a physical damage progression in the microstructure which was difficult to quantify. OP TMF loadings produced matrix cracking exclusively associated with surface initiations. Here, damage progression was easily distinguished in terms of both the number of cracks and their relative inward progressions toward the outer fiber rows with increased cycling. The point at which the leading cracks reached the outer fiber rows (when localized fiber/matrix de-bonding and matrix crack bridging occurred) appeared to be reflected in the macroscopic property degradation curves.

  4. [Regulatory mechanism of circulating inorganic phosphate].

    PubMed

    Michigami, Toshimi

    2016-02-01

    Circulating level of phosphate is altered by age and diet, and is also controlled by several hormones such as parathyroid hormone(PTH), 1,25-dihydroxyvitamin D[1,25(OH)2D]and fibroblast growth factor 23(FGF23). The main function of PTH and 1,25(OH)2D is maintaining calcium homeostasis, while FGF23 plays a central role in phosphate metabolism. PTH suppresses phosphate reabsorption in the proximal tubules to increase the renal phosphate wasting, while 1,25(OH)2D facilitates the intestinal phosphate absorption. FGF23 increases the renal phosphate wasting and reduces the production of 1,25(OH)2D. Of note, these hormones mutually regulate one another. The production of FGF23 is also regulated by various local factors. The mechanism for sensing the phosphate availability still remains unknown, and further investigation is required. PMID:26813498

  5. Phosphate uptake kinetics by Acinetobacter isolates.

    PubMed

    Pauli, A S; Kaitala, S

    1997-02-01

    Acinetobacter isolates from activated sludge treatment plants of forest industry were used as model organisms for polyphosphate accumulating bacteria to study excess phosphate uptake by the overplus phenomenon as well as luxury uptake of phosphate during growth. The initial, rapid phosphate uptake by the phosphorus-starved Acinetobacter isolates (the overplus phenomenon) followed the Michaelis-Menten model (maximum initial phosphate uptake rate 29 mg P g(-1) dry mass (DM) h(-1), half-saturation constant for excess phosphate uptake 17 mg P L(-1)). During the rapid uptake no growth was observed, but most cells contained polyphosphate granules. Also growth and luxury uptake of phosphate could be modeled with the Michaelis-Menten equation (maximum phosphate uptake rate 3.7-12 mg P g(-1) DM h(-1), half-saturation constant for growth 0.47-6.0 mg P L(-1), maximum specific growth rate 0.15-0.55 h(-1)). PMID:18633985

  6. Calcium phosphate in catheter encrustation.

    PubMed

    Cox, A J; Harries, J E; Hukins, D W; Kennedy, A P; Sutton, T M

    1987-02-01

    Encrusted catheters from nine female patients were the source of samples of deposits which were examined by X-ray diffraction, atomic absorption spectroscopy, infra-red spectroscopy and extended X-ray absorption fine structure (EXAFS) spectroscopy. In eight samples the only crystalline phase which could be clearly distinguished by X-ray diffraction was ammonium magnesium orthophosphate hexahydrate, NH4MgPO4 X 6H2O, which occurs naturally as the mineral struvite. However, atomic absorption spectroscopy revealed an appreciable concentration of calcium in all samples. Calcium phosphates have previously been detected in catheter deposits. Infra-red and EXAFS spectra were consistent with the calcium phosphate being present as a poorly crystalline hydroxyapatite. Thus the deposits appear to consist of a mixture of crystalline struvite and a form of hydroxyapatite which is not fully crystalline. PMID:3030487

  7. About Calcium Phosphate Cements (CPC)

    NASA Astrophysics Data System (ADS)

    Piñera, Silvia; Piña, Cristina

    2006-09-01

    Calcium phosphate cements (CPC) are used in orthopaedic surgery as bone substitution and fixation of metallic implants, showing advantages with respect to other materials like polymeric cements or ceramic blocks also used for bone repair. For example, they are easy to shape and fill bone defects, react at low temperature and their setting product is hydroxyapatite, mineral from it's composed the inorganic part of the bone, resulting a bioabsorbable material that can be replaced by new bone. Nevertheless there are still some complications like their low absorption rate, inyectability, setting times and their low strength that limits their use to only non load bearing applications. In this work we present a brief resume of some investigations that has been proposed to solve some of these problems, like the addition of phosphates solutions or seeds to increase the reaction rate, or fibers and hard particles to produce a composite material.

  8. Glucose-6-Phosphate Dehydrogenase Deficiency.

    PubMed

    Luzzatto, Lucio; Nannelli, Caterina; Notaro, Rosario

    2016-04-01

    G6PD is a housekeeping gene expressed in all cells. Glucose-6-phosphate dehydrogenase (G6PD) is part of the pentose phosphate pathway, and its main physiologic role is to provide NADPH. G6PD deficiency, one of the commonest inherited enzyme abnormalities in humans, arises through one of many possible mutations, most of which reduce the stability of the enzyme and its level as red cells age. G6PD-deficient persons are mostly asymptomatic, but they can develop severe jaundice during the neonatal period and acute hemolytic anemia when they ingest fava beans or when they are exposed to certain infections or drugs. G6PD deficiency is a global health issue. PMID:27040960

  9. Bioavailable dietary phosphate, a mediator of cardiovascular disease, may be decreased with plant-based diets, phosphate binders, niacin, and avoidance of phosphate additives.

    PubMed

    McCarty, Mark F; DiNicolantonio, James J

    2014-01-01

    Increased fasting serum phosphate within the normal physiological range has been linked to increased cardiovascular risk in prospective epidemiology; increased production of fibroblast growth factor 23, and direct vascular effects of phosphate, may mediate this risk. Although dietary phosphate intake does not clearly influence fasting serum phosphate in individuals with normal renal function, increased phosphate intake can provoke a rise in fibroblast growth factor 23, and in diurnal phosphate levels, and hence may adversely influence vascular health. Dietary phosphate absorption can be moderated by emphasizing plant-based dietary choices (which provide phosphate in less bioavailable forms); avoidance of processed foods containing inorganic phosphate food additives; and by ingestion of phosphate-binder drugs, magnesium supplements, or niacin, which precipitate phosphate or suppress its gastrointestinal absorption. The propensity of dietary phosphate to promote vascular calcification may be opposed by optimal intakes of magnesium, vitamin K, and vitamin D; the latter should also counter the tendency of phosphate to elevate parathyroid hormone. PMID:24984987

  10. Chloride- and alkali-containing calcium phosphates as basic materials to prepare calcium phosphate cements.

    PubMed

    Bermúdez, O; Boltong, M G; Driessens, F C; Ginebra, M P; Fernández, E; Planell, J A

    1994-10-01

    Combinations of an alkali-containing calcium phosphate-like rhenanite, sodium whitlockite or calcium potassium phosphate and a chloride-containing calcium phosphate-like spodiosite or chloroapatite with or without additions of other calcium phosphates like monocalcium phosphate monohydrate, dicalcium phosphate or dicalcium phosphate dihydrate were made and mixed with water into pastes. The setting time of these pastes was determined. After soaking for a day in Ringer's solution at 37 degrees C the compressive strength and the diametral tensile strength were determined. Two of the combinations tried in this study resulted in the formation of cements at room temperature. One cement was of the type dicalcium phosphate, whereas the other gave octocalcium phosphate as the solid reaction product. The byproducts formed were an aqueous solution of NaCl and one of K2HPO4, respectively. Applications for bone repair and augmentation are envisaged. PMID:7841290

  11. A vacuolar phosphate transporter essential for phosphate homeostasis in Arabidopsis

    PubMed Central

    Liu, Jinlong; Yang, Lei; Luan, Mingda; Wang, Yuan; Zhang, Chi; Zhang, Bin; Shi, Jisen; Zhao, Fu-Geng; Lan, Wenzhi; Luan, Sheng

    2015-01-01

    Inorganic phosphate (Pi) is stored in the vacuole, allowing plants to adapt to variable Pi availability in the soil. The transporters that mediate Pi sequestration into vacuole remain unknown, however. Here we report the functional characterization of Vacuolar Phosphate Transporter 1 (VPT1), an SPX domain protein that transports Pi into the vacuole in Arabidopsis. The vpt1 mutant plants were stunted and consistently retained less Pi than wild type plants, especially when grown in medium containing high levels of Pi. In seedlings, VPT1 was expressed primarily in younger tissues under normal conditions, but was strongly induced by high-Pi conditions in older tissues, suggesting that VPT1 functions in Pi storage in young tissues and in detoxification of high Pi in older tissues. As a result, disruption of VPT1 rendered plants hypersensitive to both low-Pi and high-Pi conditions, reducing the adaptability of plants to changing Pi availability. Patch-clamp analysis of isolated vacuoles showed that the Pi influx current was severely reduced in vpt1 compared with wild type plants. When ectopically expressed in Nicotiana benthamiana mesophyll cells, VPT1 mediates vacuolar influx of anions, including Pi, SO42−, NO3−, Cl−, and malate with Pi as that preferred anion. The VPT1-mediated Pi current amplitude was dependent on cytosolic phosphate concentration. Single-channel analysis showed that the open probability of VPT1 was increased with the increase in transtonoplast potential. We conclude that VPT1 is a transporter responsible for vacuolar Pi storage and is essential for Pi adaptation in Arabidopsis. PMID:26554016

  12. A vacuolar phosphate transporter essential for phosphate homeostasis in Arabidopsis.

    PubMed

    Liu, Jinlong; Yang, Lei; Luan, Mingda; Wang, Yuan; Zhang, Chi; Zhang, Bin; Shi, Jisen; Zhao, Fu-Geng; Lan, Wenzhi; Luan, Sheng

    2015-11-24

    Inorganic phosphate (Pi) is stored in the vacuole, allowing plants to adapt to variable Pi availability in the soil. The transporters that mediate Pi sequestration into vacuole remain unknown, however. Here we report the functional characterization of Vacuolar Phosphate Transporter 1 (VPT1), an SPX domain protein that transports Pi into the vacuole in Arabidopsis. The vpt1 mutant plants were stunted and consistently retained less Pi than wild type plants, especially when grown in medium containing high levels of Pi. In seedlings, VPT1 was expressed primarily in younger tissues under normal conditions, but was strongly induced by high-Pi conditions in older tissues, suggesting that VPT1 functions in Pi storage in young tissues and in detoxification of high Pi in older tissues. As a result, disruption of VPT1 rendered plants hypersensitive to both low-Pi and high-Pi conditions, reducing the adaptability of plants to changing Pi availability. Patch-clamp analysis of isolated vacuoles showed that the Pi influx current was severely reduced in vpt1 compared with wild type plants. When ectopically expressed in Nicotiana benthamiana mesophyll cells, VPT1 mediates vacuolar influx of anions, including Pi, SO4(2-), NO3(-), Cl(-), and malate with Pi as that preferred anion. The VPT1-mediated Pi current amplitude was dependent on cytosolic phosphate concentration. Single-channel analysis showed that the open probability of VPT1 was increased with the increase in transtonoplast potential. We conclude that VPT1 is a transporter responsible for vacuolar Pi storage and is essential for Pi adaptation in Arabidopsis. PMID:26554016

  13. Insight into biological phosphate recovery from sewage.

    PubMed

    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. PMID:27434305

  14. Phosphate-limited culture of Azotobacter vinelandii.

    PubMed Central

    Tsai, J C; Aladegbami, S L; Vela, G R

    1979-01-01

    Batch cultures of Azotobacter vinelandii grown in phosphate-deficient media were compared with control cultures grown in phosphate-sufficient media. Phosphate limitation was assessed by total cell yield and by growth kinetics. Although cell protein, nucleic acids, and early growth rate were unaffected by phosphate deficiency, cell wall structure, oxygen uptake, and cell viability were significantly affected. Also, phosphate-limited cells contained much larger amounts of poly-beta-hydroxybutyric acid but lower adenylate nucleotide energy charge than did control cells. The ratio of adenosine 5'-triphosphate to adenosine 5'-diphosphate was much lower in phosphate-deficient cells. The data indicate a substrate saving choice of three metabolic pathways available to this organism under different growth conditions. Images PMID:457614

  15. Application of Calcium Phosphate Materials in Dentistry

    PubMed Central

    Al-Sanabani, Jabr S.; Al-Sanabani, Fadhel A.

    2013-01-01

    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. PMID:23878541

  16. D21S418E identifies a cAMP-regulated gene located on chromosome 21q22. 3 that is expressed in placental syncytiotrophoblast and choriocarcinoma cells

    SciTech Connect

    Kido, S.; Sakuragi, N.; Bronner, M.P.; Sayegh, R.; Strauss, J.F. III ); Berger, R.; Patterson, D. )

    1993-07-01

    A partial cDNA (D21S418E) whose nucleotide sequence has no significant homologies with known mammalian DNA sequences was isolated from a human placental library. The cDNA hybridized with a 10-kb transcript present in term placenta. Messages of 10 and 7.5 kb were induced in BeWo and JEG-3 choriocarcinoma cells by treatment with 8-Br-cAMP. The mRNA was not detected in human brain, liver, lung, kidney, pancreas, heart, skeletal muscle, or myometrium. The D21S418E locus was assigned to a 3.5-Mb region of chromosome 21q22.3. 15 refs., 2 figs., 1 tab.

  17. Characterisation of variant alleles at the HumD21S11 locus implies unique Australasian genotypes and re-classification of nomenclature guidelines.

    PubMed

    Walsh, Simon J; Robinson, Sarah L; Turbett, Gavin R; Davies, Neil P; Wilton, Alan N

    2003-07-29

    Several variant alleles of the HumD21S11 locus have only been reported in Australasian population samples. Fifteen such alleles were observed in Caucasian and Australian Aborigine sub-population databases compiled from residents of the state of Western Australia. Each variant was sequenced to authenticate the allelic designation and determine the structural conformation. Nine novel structural variants are described. The structure of the repeat region of these rare alleles combined with the STR designation brings aspects of the HumD21S11 nomenclature guidelines into question, in particular the designation of common incomplete repeats (or "0.2's"). The conformation of the sequences provides evidence in support of a genetic relationship between the Australian Aborigine and the Papuan people. PMID:12893133

  18. Mineral induced formation of sugar phosphates

    NASA Astrophysics Data System (ADS)

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

    1995-08-01

    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-diphosphates 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 µm; 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.

  19. Preparation of porous lanthanum phosphate with templates

    SciTech Connect

    Onoda, Hiroaki; Ishima, Yuya; Takenaka, Atsushi; Tanaka, Isao

    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.

  20. Next generation calcium phosphate-based biomaterials

    PubMed Central

    LC, Chow

    2009-01-01

    It has been close to a century since calcium phosphate materials were first used as bone graft substitutes. Numerous studies conducted in the last two decades have produced a wealth of information on the chemistry, in vitro properties, and biological characteristics of granular calcium phosphates and calcium phosphate cement biomaterials. An in depth analysis of several key areas of calcium phosphate cement properties is presented with the aim of developing strategies that could lead to break-through improvements in the functional efficacies of these materials. PMID:19280963

  1. Mineral induced formation of sugar phosphates

    NASA Technical Reports Server (NTRS)

    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.

  2. Phosphate transporters and their function.

    PubMed

    Biber, Jürg; Hernando, Nati; Forster, Ian

    2013-01-01

    Plasma phosphate concentration is maintained within a relatively narrow range by control of renal reabsorption of filtered inorganic phosphate (P(i)). P(i) reabsorption is a transcellular process that occurs along the proximal tubule. P(i) flux at the apical (luminal) brush border membrane represents the rate-limiting step and is mediated by three Na(+)-dependent P(i) cotransporters (members of the SLC34 and SLC20 families). The putative proteins responsible for basolateral P(i) flux have not been identified. The transport mechanism of the two kidney-specific SLC34 proteins (NaPi-IIa and NaPi-IIc) and of the ubiquitously expressed SLC20 protein (PiT-2) has been studied by heterologous expression to reveal important differences in kinetics, stoichiometry, and substrate specificity. Studies on the regulation of the abundance of the respective proteins highlight significant differences in the temporal responses to various hormonal and nonhormonal factors that can influence P(i) homeostasis. The phenotypes of mice deficient in NaPi-IIa and NaPi-IIc indicate that NaPi-IIa is responsible for most P(i) renal reabsorption. In contrast, in the human kidney, NaPi-IIc appears to have a relatively greater role. The physiological relevance of PiT-2 to P(i) reabsorption remains to be elucidated. PMID:23398154

  3. Zirconium Phosphate Supported MOF Nanoplatelets.

    PubMed

    Kan, Yuwei; Clearfield, Abraham

    2016-06-01

    We report a rare example of the preparation of HKUST-1 metal-organic framework nanoplatelets through a step-by-step seeding procedure. Sodium ion exchanged zirconium phosphate, NaZrP, nanoplatelets were judiciously selected as support for layer-by-layer (LBL) assembly of Cu(II) and benzene-1,3,5-tricarboxylic acid (H3BTC) linkers. The first layer of Cu(II) is attached to the surface of zirconium phosphate through covalent interaction. The successive LBL growth of HKUST-1 film is then realized by soaking the NaZrP nanoplatelets in ethanolic solutions of cupric acetate and H3BTC, respectively. The amount of assembled HKUST-1 can be readily controlled by varying the number of growth cycles, which was characterized by powder X-ray diffraction and gas adsorption analyses. The successful construction of HKUST-1 on NaZrP was also supported by its catalytic performance for the oxidation of cyclohexene. PMID:27175935

  4. The SLC37 Family of Sugar-Phosphate/Phosphate Exchangers

    PubMed Central

    Chou, Janice Y.; Mansfield, Brian C.

    2014-01-01

    The SLC37 family members are endoplasmic reticulum (ER)-associated sugar-phosphate/phosphate (Pi) exchangers. Three of the four members, SLC37A1, SLC37A2, and SLC37A4, function as Pi-linked glucose-6-phosphate (G6P) antiporters catalyzing G6P:Pi and Pi:Pi exchanges. The activity of SLC37A3 is unknown. SLC37A4, better known as the G6P transporter (G6PT), has been extensively characterized, functionally and structurally, and is the best characterized family member. G6PT contains 10 transmembrane helices with both N and C termini facing the cytoplasm. The primary in vivo function of the G6PT protein is to translocate G6P from the cytoplasm into the ER lumen where it couples with either the liver/kidney/intestine-restricted glucose-6-phosphatase-α (G6Pase-α or G6PC) or the ubiquitously expressed G6Pase-β (or G6PC3) to hydrolyze G6P to glucose and Pi. The G6PT/G6Pase-α complex maintains interprandial glucose homeostasis, and the G6PT/G6Pase-β complex maintains neutro-phil energy homeostasis and functionality. G6PT is highly selective for G6P and is competitively inhibited by cholorogenic acid and its derivatives. Neither SLC37A1 nor SLC37A2 can couple functionally with G6Pase-α or G6Pase-β, and the antiporter activities of SLC37A1 or SLC37A2 are not inhibited by cholorogenic acid. Deficiencies in G6PT cause glycogen storage disease type Ib (GSD-Ib), a metabolic and immune disorder. To date, 91 separate SLC37A4 mutations, including 39 missense mutations, have been identified in GSD-Ib patients. Characterization of missense mutations has yielded valuable information on functionally important residues in the G6PT protein. The biological roles of the other SLC37 proteins remain to be determined and deficiencies have not yet been correlated to diseases. PMID:24745989

  5. 21 CFR 582.5301 - Ferric phosphate.

    Code of Federal Regulations, 2010 CFR

    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 DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5301 Ferric phosphate....

  6. 21 CFR 582.5217 - Calcium phosphate.

    Code of Federal Regulations, 2010 CFR

    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 DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5217 Calcium phosphate....

  7. 21 CFR 137.175 - Phosphated flour.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... requirements of this section allowance is made for the added monocalcium phosphate. ... label declaration of ingredients, prescribed for flour by § 137.105, except that: (a) Monocalcium phosphate is added in a quantity not less than 0.25 percent and not more than 0.75 percent of the weight...

  8. 21 CFR 137.175 - Phosphated flour.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... requirements of this section allowance is made for the added monocalcium phosphate. ... label declaration of ingredients, prescribed for flour by § 137.105, except that: (a) Monocalcium phosphate is added in a quantity not less than 0.25 percent and not more than 0.75 percent of the weight...

  9. 21 CFR 137.175 - Phosphated flour.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... requirements of this section allowance is made for the added monocalcium phosphate. ... label declaration of ingredients, prescribed for flour by § 137.105, except that: (a) Monocalcium phosphate is added in a quantity not less than 0.25 percent and not more than 0.75 percent of the weight...

  10. 21 CFR 137.175 - Phosphated flour.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... requirements of this section allowance is made for the added monocalcium phosphate. ... label declaration of ingredients, prescribed for flour by § 137.105, except that: (a) Monocalcium phosphate is added in a quantity not less than 0.25 percent and not more than 0.75 percent of the weight...

  11. 21 CFR 182.6290 - Disodium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Disodium phosphate. 182.6290 Section 182.6290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 1 § 182.6290 Disodium phosphate. (a) Product. Disodium...

  12. Drug-pyridoxal phosphate interactions.

    PubMed

    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) PMID:6087425

  13. Phosphate rock resources of the United States

    USGS Publications Warehouse

    Cathcart, James Bachelder; Sheldon, Richard Porter; Gulbrandsen, Robert A.

    1984-01-01

    In 1980, the United States produced about 54 million tons of phosphate rock, or about 40 percent of the world's production, of which a substantial amount was exported, both as phosphate rock and as chemical fertilizer. During the last decade, predictions have been made that easily ruinable, low-cost reserves of phosphate rock would be exhausted, and that by the end of this century, instead of being a major exporter of phosphate rock, the United States might become a net importer. Most analysts today, however, think that exports will indeed decline in the next one or two decades, but that resources of phosphate are sufficient to supply domestic needs for a long time into the future. What will happen in the future depends on the actual availability of low-cost phosphate rock reserves in the United States and in the world. A realistic understanding of future phosphate rock reserves is dependent on an accurate assessment, now, of national phosphate rock resources. Many different estimates of resources exist; none of them alike. The detailed analysis of past resource estimates presented in this report indicates that the estimates differ more in what is being estimated than in how much is thought to exist. The phosphate rock resource classification used herein is based on the two fundamental aspects of a mineral resource(l) the degree of certainty of existence and (2) the feasibility of economic recovery. The comparison of past estimates (including all available company data), combined with the writers' personal knowledge, indicates that 17 billion metric tons of identified, recoverable phosphate rock exist in the United States, of which about 7 billion metric tons are thought to be economic or marginally economic. The remaining 10 billion metric tons, mostly in the Northwestern phosphate district of Idaho, are considered to be subeconomic, ruinable when some increase in the price of phosphate occurs. More than 16 billion metric tons probably exist in the southeastern

  14. Phosphate transport and arsenate resistance in the cyanobacterium Anabaena variabilis

    SciTech Connect

    Thiel, T.

    1988-03-01

    Cells of the cyanobacterium Anabaena variabilis starved for phosphate for 3 days took up phosphate at about 100 times the rate of unstarved cells.Kinetic data suggested that a new transport system had been induced by starvation for phosphate. The inducible phosphate transport system was quickly repressed by addition of P/sub i/. Phosphate-starved cells were more sensitive to the toxic effects of arsenate than were unstarved cells, but phosphate could alleviate some of the toxicity. Arsenate was a noncompetitive inhibitor of phosphate transport; however, the apparent K/sub i/ values were high, particularly for phosphate-replete cells. Preincubation of phosphate-starved cells with arsenate caused subsequent inhibition of phosphate transport, suggesting that intracellular arsenate inhibited phosphate transport. This effect was not seen in phosphate-replete cells.

  15. Nanoporous sorbent material as an oral phosphate binder and for aqueous phosphate, chromate, and arsenate removal

    PubMed Central

    Sangvanich, Thanapon; Ngamcherdtrakul, Worapol; Lee, Richard; Morry, Jingga; Castro, David; Fryxell, Glen E.; Yantasee, Wassana

    2014-01-01

    Phosphate removal is both biologically and environmentally important. Biologically, hyperphosphatemia is a critical condition in end-stage chronic kidney disease patients. Patients with hyperphosphatemia are treated long-term with oral phosphate binders to prevent phosphate absorption to the body by capturing phosphate in the gastrointestinal (GI) tract followed by fecal excretion. Environmentally, phosphate levels in natural water resources must be regulated according to limits set forth by the US Environmental Protection Agency. By utilizing nanotechnology and ligand design, we developed a new material to overcome limitations of traditional sorbent materials such as low phosphate binding capacity, slow binding kinetics, and negative interference by other anions. A phosphate binder based on iron-ethylenediamine on nanoporous silica (Fe-EDA-SAMMS) has been optimized for substrates and Fe(III) deposition methods. The Fe-EDA-SAMMS material had a 4-fold increase in phosphate binding capacity and a broader operating pH window compared to other reports. The material had a faster phosphate binding rate and was significantly less affected by other anions than Sevelamer HCl, the gold standard oral phosphate binder, and AG® 1-X8, a commercially available anion exchanger. It had less cytotoxicity to Caco-2 cells than lanthanum carbonate, another prescribed oral phosphate binder. The Fe-EDA-SAMMS also had high capacity for arsenate and chromate, two of the most toxic anions in natural water. PMID:25554735

  16. Phosphate Biomineralization of Cambrian Microorganisms

    NASA Technical Reports Server (NTRS)

    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.

  17. Levels of Phosphate Esters in Spirodela

    PubMed Central

    Bieleski, R. L.

    1968-01-01

    The duckweed Spirodela oligorrhiza was grown in sterile nutrient solutions that contained 1 mm phosphate-32P at various specific activities. In solutions with activities higher than 2 μc per μmole per ml, plant growth was inhibited after a time, and the physical appearance of the plants was affected. The critical level of radiation, at which growth was first affected, corresponded to 5 kilorads. Plants were grown for 9 days (5 generations) in a culture solution containing phosphate at 0.5 μc per μmole per ml (radiation load approx 0.5 kilorads) so that all phosphorus-containing materials in the tissue became uniformly labeled. The various radioactive compounds were extracted, chromatographed, identified, and their radioactivity was measured. From this radioactivity plus the specific activity of the supplied phosphate, the amount of each compound was calculated. The data constitute a complete balance-sheet for phosphorus in a plant tissue. The identity of 98% of the phosphorus in the tissue was determined. Inorganic phosphate (32,700 mμmoles/g fr wt) was the predominant phosphorus-containing compound; RNA (5100 mμmoles P/g fr wt) was the main organic phosphate; phosphatidyl choline (1600 mμmoles/g fr wt) was the main phospholipid, and glucose-6-phosphate (500 mμmoles/g fr wt) the main acid-soluble phosphate ester. Amounts of other phosphorus compounds are given. Images PMID:16656910

  18. Are Polyphosphates or Phosphate Esters Prebiotic Reagents?

    NASA Technical Reports Server (NTRS)

    Keefe, Anthony D.; Miller, Stanley L.

    1995-01-01

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

  19. Aquatic Toxicity Assessment of Phosphate Compounds

    PubMed Central

    Kim, Eunju; Yoo, Sunkyoung; Ro, Hee-Young; Han, Hye-Jin; Baek, Yong-Wook; Eom, Ig-Chun; Kim, Pilje; Choi, Kyunghee

    2013-01-01

    Objectives Tricalcium phosphate and calcium hydrogenorthophosphate are high production volume chemicals, mainly used as foodstuff additives, pharmaceuticals, lubricants, synthetic resin, and disinfectants. Phosphate has the potential to cause increased algal growth leading to eutrophication in the aquatic environment. However, there is no adequate information available on risk assessment or acute and chronic toxicity. The aim of this research is to evaluate the toxic potential of phosphate compounds in the aquatic environment. Methods An aquatic toxicity test of phosphate was conducted, and its physico-chemical properties were obtained from a database recommended in the Organization for Economic Cooperation and Development (OECD) guidance manual. An ecotoxicity test using fish, Daphnia, and algae was conducted by the good laboratory practice facility according to the OECD TG guidelines for testing of chemicals, to secure reliable data. Results The results of the ecotoxicity tests of tricalcium phosphate and calcium hydrogenorthophosphate are as follows: In an acute toxicity test with Oryzias latipes, 96 hr 50% lethal concentration (LC50) was >100 (measured:>2.14) mg/L and >100 (measured: >13.5) mg/L, respectively. In the Daphnia test, 48 hr 50% effective concentration (EC50) was >100 (measured: >5.35) mg/L and >100 (measured: >2.9) mg/L, respectively. In a growth inhibition test with Pseudokirchneriella subcapitata, 72 hr EC50 was >100 (measured: >1.56) mg/L and >100 (measured: >4.4) mg/L, respectively. Conclusions Based on the results of the ecotoxicity test of phosphate using fish, Daphnia, and algae, L(E)C50 was above 100 mg/L (nominal), indicating no toxicity. In general, the total phosphorus concentration including phosphate in rivers and lakes reaches levels of several ppm, suggesting that phosphate has no toxic effects. However, excessive inflow of phosphate into aquatic ecosystems has the potential to cause eutrophication due to algal growth. PMID:23440935

  20. BISMUTH PHOSPHATE CARRIER PROCESS FOR Pu RECOVERY

    DOEpatents

    Finzel, T.G.

    1959-02-01

    An improvement in the bismuth phosphate carrier precipitation process for recovering plutonium is described. It has been found that a more granular and more easily filterable carrier precipitiite is formed if the addition of the bismuth and phosphate ions is effected by first adding 9/10 of the bismuth ions necessary, then slowly adding all of the source of the phosphate ions to be incorporated in the precipitate, while digesting at 75 C and afterwards incorporating the remainder of the total bismuth ions necessary

  1. Phosphate-bonded calcium aluminate cements

    DOEpatents

    Sugama, T.

    1993-09-21

    A method is described for making a rapid-setting phosphate-bonded cementitious material. A powdered aluminous cement is mixed with an aqueous solution of ammonium phosphate. The mixture is allowed to set to form an amorphous cementitious material which also may be hydrothermally treated at a temperature of from about 120 C to about 300 C to form a crystal-containing phosphate-bonded material. Also described are the cementitious products of this method and the cement composition which includes aluminous cement and ammonium polyphosphate. 10 figures.

  2. Phosphate-bonded calcium aluminate cements

    DOEpatents

    Sugama, Toshifumi

    1993-01-01

    A method is described for making a rapid-setting phosphate-bonded cementitious material. A powdered aluminous cement is mixed with an aqueous solution of ammonium phosphate. The mixture is allowed to set to form an amorphous cementitious material which also may be hydrothermally treated at a temperature of from about 120.degree. C. to about 300.degree. C. to form a crystal-containing phosphate-bonded material. Also described are the cementitious products of this method and the cement composition which includes aluminous cement and ammonium polyphosphate.

  3. [Adsorption of Phosphate by Lanthanum Hydroxide/Natural Zeolite Composites from Low Concentration Phosphate Solution].

    PubMed

    Lin, Jian-wei; Wang, Hong; Zhan, Yan-hui; Chen, Dong-mei

    2016-01-15

    A series of composites of lanthanum hydroxide/natural zeolite ( La( OH) 3/NZ composites) were prepared by co-precipitation method, and these composites were used as adsorbents to remove phosphate from aqueous solution. The phosphate adsorption capacities of different composites prepared with different precipitated pH values were compared in batch mode. The adsorption characteristics of phosphate from aqueous solution on the La(OH)3/NZ composite prepared with the precipitated pH value of 11 was investigated using batch experiments. The results showed that the La(OH)3/NZ composite prepared with the precipitated pH values of 5-7 and 13 had a low adsorption capacity for phosphate in aqueous solution, while the La( OH) 3/NZ composites prepared with the precipitated pH values of 9-12 exhibited much higher phosphate adsorption capacity. The phosphate adsorption capacity of the La (OH)3/NZ composite increased with the increase of the precipitated pH value from 9 to 11, but remained basically unchanged with the increase of the precipitated pH value from 11 to 12. The equilibrium adsorption data of phosphate from aqueous solution on the La ( OH ) 3/NZ composite prepared with the precipitated pH value of 11 could be described by the Langmuir isotherm model with the predicted maximum phosphate adsorption of 44 mg x g(-1) (phosphate solution pH 7 and 30 degrees C). The kinetic data of phosphate adsorption from low concentration phosphate solution on the La(OH)3/NZ composite prepared with the precipitated pH value of 11 well followed a pseudo-second-order model. The presence of Cl- and SO4(2-) in low concentration phosphate solution had no negative effect on phosphate adsorption onto the La(OH)3/NZ composite prepared with the precipitated pH value of 11, while the presence of HCO3- slightly inhibited the adsorption of phosphate. Coexisting humic acid had a negative effect on the adsorption of phosphate at low concentration on the La(OH)3/NZ composite prepared with the

  4. Phosphate stimulates CFTR Cl- channels.

    PubMed Central

    Carson, M R; Travis, S M; Winter, M C; Sheppard, D N; Welsh, M J

    1994-01-01

    Cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channels appear to be regulated by hydrolysis of ATP and are inhibited by a product of hydrolysis, ADP. We assessed the effect of the other product of hydrolysis, inorganic phosphate (P(i)), on CFTR Cl- channel activity using the excised inside-out configuration of the patch-clamp technique. Millimolar concentrations of P(i) caused a dose-dependent stimulation of CFTR Cl- channel activity. Single-channel analysis demonstrated that the increase in macroscopic current was due to an increase in single-channel open-state probability (po) and not single-channel conductance. Kinetic modeling of the effect of P(i) using a linear three-state model indicated that the effect on po was predominantly the result of an increase in the rate at which the channel passed from the long closed state to the bursting state. P(i) also potentiated activity of channels studied in the presence of 10 mM ATP and stimulated Cl- currents in CFTR mutants lacking much of the R domain. Binding studies with a photoactivatable ATP analog indicated that Pi decreased the amount of bound nucleotide. These results suggest that P(i) increased CFTR Cl- channel activity by stimulating a rate-limiting step in channel opening that may occur by an interaction of P(i) at one or both nucleotide-binding domains. Images FIGURE 8 PMID:7532021

  5. Phosphate Oxygen Isotopes as a Tracer for Sources and Cycling of Phosphate in San Francisco Bay

    NASA Astrophysics Data System (ADS)

    McLaughlin, K.; Paytan, A.; Kendall, C.; Silva, S.

    2004-12-01

    Phosphorous is an essential macro-nutrient for primary productivity, but tracing sources and cycling of P in marine systems has been difficult to assess because P has only one stable isotope and can not be used as an isotopic tracer. Recently a new technique (McLaughlin et al., 2004) has been developed to track sources and cycling of phosphate in aquatic systems. This approach takes advantage of the strong P-O bond in phosphate, which is resistant to inorganic hydrolysis. The exchange of oxygen isotopes therein only occurs due to intracellular biological cycling. Because the d18O of phosphate will largely be determined by the isotopic composition of the water in which it is being recycled and because the isotopic composition of rivers and oceans is significantly different, the d18O of phosphate may be used as a tracer for different sources of phosphate to an estuarine system which is not phosphate limited. Consequently, the d18O of phosphate may be useful for quantifying the mixing of different sources of phosphate in estuarine systems. We applied this method to enhance our understanding of P sources and cycling in the San Francisco Bay. To this end we conducted four sampling transects from Coyote Creek in the South Bay to the Sacramento and San Joaquin Rivers in the North between October 2002 and August 2004. Phosphate d18O ranged from 10.1 to 20.1 per mil, with highest values at the Golden Gate and lowest at the San Joaquin River. Most of the Bay samples showed strong positive correlations with salinity, water d18O, and the inverse of phosphate concentration, suggesting a simple two-component mixing of oceanic and riverine sources. These data suggest that phosphate d18O can be an effective tool for identifying P point sources and understanding phosphate dynamics in the ecosystem.

  6. The oxygen isotopic composition of phosphate in Elkhorn Slough, California: A tracer for phosphate sources

    NASA Astrophysics Data System (ADS)

    McLaughlin, Karen; Cade-Menun, Barbara J.; Paytan, Adina

    2006-11-01

    Elkhorn Slough, a small seasonal estuary in central California, has been subjected to increased nutrient loading from agricultural and other non-point sources. However, because nutrients do not behave conservatively, tracing nutrient sources and cycling in ecosystems like Elkhorn Slough has been difficult to assess. This is particularly true of phosphorus (P), which has only one stable isotope and cannot be used as an isotopic tracer. However, isotopic fractionation of oxygen in phosphate at surface water temperatures only occurs as a result of enzyme-mediated, biochemical reactions. Thus, if phosphate demand is low relative to input and is not heavily cycled within the ecosystem, the δ18O of phosphate will reflect the isotopic composition of phosphate sources to the system. We utilized the δ18O of dissolved inorganic phosphate (DIP) within the main channel of the slough and nearby Moss Landing Harbor and the δ18O of reactive phosphate from sediment and soil samples collected within the watershed to understand phosphate sources and cycling within Elkhorn Slough. Trends in the δ18O of DIP were seasonally consistent with high values near the mouth reflecting oceanic phosphate (19.1‰-20.3‰), dropping to a minimum value near Hummingbird Island in the central slough (point source, 14.1‰-14.4‰), and increasing again near the head of the slough, reflecting fertilizer input (18.9‰-19.3‰). Reactive phosphate δ18O values extracted from sediments and soils in the watershed range from 10.6‰ in a drainage ditch to 22.3‰ in creek sediments near agriculture fields. The wide range in phosphate δ18O values reflects the variations in land use and application of different fertilizers in this agriculturally dominated landscape. These data suggest that phosphate δ18O can be an effective tool for identifying P sources and understanding phosphate dynamics in estuarine ecosystems.

  7. Issues of natural radioactivity in phosphates

    SciTech Connect

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

    1996-12-31

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

  8. Enzyme activity in dialkyl phosphate ionic liquids.

    PubMed

    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. PMID:22001053

  9. Do osteocytes contribute to phosphate homeostasis?

    PubMed

    Feng, Jian Q; Ye, Ling; Schiavi, Susan

    2009-07-01

    Osteocytes, the terminally differentiated cell of the osteoblast lineage, account for over 90% of all bone cells. Due to their relative inaccessibility within mineralized matrix, little is known regarding their specific functions in comparison to the well studied surface bone cells, osteoblasts and osteoclasts. Furthermore, bone is often viewed as a mineral reservoir that passively releases calcium and phosphate in response to hormones secreted from remote organs. Noncollagenous matrix proteins produced in osteocytes, such as dentin matrix protein 1 (DMP1), have also been viewed as inert scaffolds for calcium-phosphate deposition. Recent discoveries of new genetic mutations in human diseases and development of genetically engineered animal models challenge these classic paradigms, suggesting that the osteocyte plays an active role in both mineralization and total systemic phosphate regulation. In this review, we will focus on roles of osteocytes in mineralization and particularly in phosphate regulation via the DMP1- FGF23 pathway. PMID:19448536

  10. Enzyme activity in dialkyl phosphate ionic liquids

    SciTech Connect

    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.

  11. Airborne radioactivity surveys for phosphate in Florida

    USGS Publications Warehouse

    Moxham, Robert M.

    1954-01-01

    Airborne radioactivity surveys totaling 5, 600 traverse miles were made in 10 areas in Florida, which were thought to be geologically favorable for deposits of uraniferous phosphate. Abnormal radioactivity was recorded in 8 of the 10 areas surveyed. The anomalies are located in Bradford, Clay, Columbia, DeSoto, Dixie, Lake, Marion, Orange, Sumter, Taylor, and Union Counties. Two of the anomalies were investigated briefly on the ground. One resulted from a deposit of river-pebble phosphate in the Peace River valley; the river-pebble samples contain an average of 0.013 percent equivalent uranium. The other anomaly resulted from outcrops of leached phosphatic rock containing as much as 0. 016 percent equivalent uranium. Several anomalies in other areas were recorded at or near localities where phosphate deposits have been reported.

  12. Airborne radioactivity surveys for phosphate in Florida

    USGS Publications Warehouse

    Moxham, Robert M.

    1953-01-01

    Airborne radioactivity surveys totalling 5,600 traverse miles were made in ten areas in Florida, which were thought to be geologically favorable for the occurrence of uraniferous phosphate deposits. Abnormal radioactivity was recorded in eight of the ten areas surveyed. The anomalies are located in Bradford, Clay, Columbia, DeSoto, Dixie, Lake, Marion, Orange, Sumter, Taylor, and Union Counties. Two of the anomalies were investigated briefly on the ground. One resulted from a deposit of river-pebble phosphate in the Peace River valley; samples of the river pebble contain an average of 0.013 percent equivalent uranium. The other anomaly resulted from outcrops of leached phosphate rock containing as much as 0.016 percent equivalent uranium. Several anomalies in other areas were recorded at or near localities where phosphate deposits have been reported to occur.

  13. 21 CFR 184.1434 - Magnesium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 179, which is incorporated by reference. Magnesium phosphate, tribasic, meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 180, which...

  14. 21 CFR 184.1434 - Magnesium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 179, which is incorporated by reference. Magnesium phosphate, tribasic, meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 180, which...

  15. 21 CFR 184.1434 - Magnesium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... phosphoric acid. (b) Magnesium phosphate, dibasic, meets the specifications of the Food Chemicals Codex, 3d... specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 180, which is incorporated by reference. Copies...

  16. 21 CFR 184.1434 - Magnesium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 179, which is incorporated by reference. Magnesium phosphate, tribasic, meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 180, which...

  17. Product inhibition of potato tuber pyrophosphate:fructose-6-phosphate phosphotransferase by phosphate and pyrophosphate.

    PubMed

    Stitt, M

    1989-02-01

    The product inhibition of potato (Solanum tuberosum) tuber pyrophosphate:fructose-6-phosphate phosphotransferase by inorganic pyrophosphate and inorganic phosphate has been studied. The binding of substrates for the forward (glycolytic) and the reverse (gluconeogenic) reaction is random order, and occurs with only weak competition between the substrate pair fructose-6-phosphate and pyrophosphate, and between the substrate pair fructose-1,6-bisphosphate and phosphate. Pyrophosphate is a powerful inhibitor of the reverse reaction, acting competitively to fructose-1,6-biphosphate and noncompetitively to phosphate. At the concentrations needed for catalysis of the reverse reaction, phosphate inhibits the forward reaction in a largely noncompetitive mode with respect to both fructose-6-phosphate and pyrophosphate. At higher concentrations, phosphate inhibits both the forward and the reverse reaction by decreasing the affinity for fructose-2,6-bisphosphate and thus, for the other three substrates. These results allow a model to be proposed, which describes the interactions between the substrates at the catalytic site. They also suggest the enzyme may be regulated in vivo by changes of the relation between metabolites and phosphate and could act as a means of controlling the cytosolic pyrophosphate concentration. PMID:16666593

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

    PubMed

    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. PMID:25909152

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

    PubMed

    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. PMID:24261118

  20. Gelatin manipulation of latent macropores formation in brushite cement.

    PubMed

    Yin, Yuji; Ye, Fen; Cai, Shu; Yao, Kangde; Cui, Junfeng; Song, Xuefeng

    2003-03-01

    Macroporous brushite cement was prepared from a mixture of beta-tricalcium phosphate (beta-TCP) and monocalcium phosphate monohydrate (MCPM) using gelatin powder as a latent templates. In a setting reaction coexisting with gelatin, closed packed, open-pore structure with 100-200 microm macropores are obtained after immersion of the set cement into PBS buffer (pH 7.4) at 37 degrees C for 1-4 weeks. The macroporous brushite cement has compressive strength of 15 MPa originally, which reducing to 5.5 MPa with macropore formation gradually in comparison to that of cancellous bone (5-10 MPa). PMID:15348472

  1. Disorders of phosphate homeostasis and tissue mineralisation.

    PubMed

    Bergwitz, Clemens; Jüppner, Harald

    2009-01-01

    Phosphate is absorbed from the diet in the gut, stored as hydroxyapatite in the skeleton, and excreted with the urine. The balance between these compartments determines the circulating phosphate concentration. Fibroblast growth factor 23 (FGF23) has recently been discovered and is part of a previously unrecognised hormonal bone-kidney axis. Phosphate-regulating gene with homologies to endopeptidases on the X chromosome, and dentin matrix protein 1 regulate the expression of FGF23 in osteocytes, which then is O-glycosylated by UDP-N-acetyl-alpha-D-galactosamine: polypeptide N-acetylgalactosaminyl-transferase 3 and secreted into the circulation. FGF23 binds with high affinity to fibroblast growth factor receptor 1c in the presence of its co-receptor Klotho. It inhibits, either directly or indirectly, reabsorption of phosphate and the synthesis of 1,25-dihydroxy-vitamin-D by the renal proximal tubule and the secretion of parathyroid hormone by the parathyroid glands. Acquired or inborn errors affecting this newly discovered hormonal system can lead to abnormal phosphate homeostasis and/or tissue mineralisation. This chapter will provide an update on the current knowledge of the pathophysiology, the clinical presentation, diagnostic evaluation and therapy of the disorders of phosphate homeostasis and tissue mineralisation. PMID:19494665

  2. The evolution of the marine phosphate reservoir.

    PubMed

    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. PMID:20981096

  3. Characterization of phosphate films on aluminum surfaces

    SciTech Connect

    Cheng, B.; Ramamurthy, S.; McIntyre, N.S.

    1997-08-01

    A thin layer of phosphate conversion coating was formed on pure aluminum in a commercial zinc-manganese phosphating bath. A number of surface analytical techniques were used to characterize the phosphate thin films formed after immersion times ranging from 30 s to 10 min. The coating contained mainly a crystalline structure with dispersed micrometer-scale cavities. The major constituents of the phosphate film were zinc, phosphorus, and oxygen; a small amount of manganese was also detected. Based on these results, a three-stage mechanism was proposed for the formation and the growth of phosphate conversion coatings on aluminum. Electrochemical impedance spectroscopy was used to evaluate the corrosion performance of phosphated and uncoated aluminum samples in 0.50 M Na{sub 2}SO{sub 4} and 0.10 M H{sub 2}SO{sub 4} solutions. Both types of samples exhibited a passive state in the neutral solution and general corrosion behavior in the acid solution.

  4. Disorders of Phosphate Homeostasis and Tissue Mineralisation

    PubMed Central

    Bergwitz, Clemens; Jüppner, Harald

    2013-01-01

    Phosphate is absorbed from the diet in the gut, stored as hydroxyapatite in the skeleton, and excreted with the urine. The balance between these compartments determines the circulating phosphate concentration. Fibroblast growth factor 23 (FGF23) has recently been discovered and is part of a previously unrecognised hormonal bone-kidney axis. Phosphate-regulating gene with homologies to endopeptidases on the X chromosome, and dentin matrix protein 1 regulate the expression of FGF23 in osteocytes, which then is O-glycosylated by UDP-N-acetyl-alpha-d-galactosamine: poly-peptide N-acetylgalactosaminyl-transferase 3 and secreted into the circulation. FGF23 binds with high affinity to fibroblast growth factor receptor 1c in the presence of its co-receptor Klotho. It inhibits, either directly or indirectly, reabsorption of phosphate and the synthesis of 1,25-dihydroxy-vita-min-D by the renal proximal tubule and the secretion of parathyroid hormone by the parathyroid glands. Acquired or inborn errors affecting this newly discovered hormonal system can lead to abnormal phosphate homeostasis and/or tissue mineralisation. This chapter will provide an update on the current knowledge of the pathophysiology, the clinical presentation, diagnostic evaluation and therapy of the disorders of phosphate homeostasis and tissue mineralisation. PMID:19494665

  5. Phosphate rock costs, prices and resources interaction.

    PubMed

    Mew, M C

    2016-01-15

    This article gives the author's views and opinions as someone who has spent his working life analyzing the international phosphate sector as an independent consultant. His career spanned two price hike events in the mid-1970's and in 2008, both of which sparked considerable popular and academic interest concerning adequacy of phosphate rock resources, the impact of rising mining costs and the ability of mankind to feed future populations. An analysis of phosphate rock production costs derived from two major industry studies performed in 1983 and 2013 shows that in nominal terms, global average cash production costs increased by 27% to $38 per tonne fob mine in the 30 year period. In real terms, the global average cost of production has fallen. Despite the lack of upward pressure from increasing costs, phosphate rock market prices have shown two major spikes in the 30 years to 2013, with periods of less volatility in between. These price spike events can be seen to be related to the escalating investment cost required by new mine capacity, and as such can be expected to be repeated in future. As such, phosphate rock price volatility is likely to have more impact on food prices than rising phosphate rock production costs. However, as mining costs rise, recycling of P will also become increasingly driven by economics rather than legislation. PMID:26412420

  6. Transport and signaling through the phosphate-binding site of the yeast Pho84 phosphate transceptor.

    PubMed

    Popova, Yulia; Thayumanavan, Palvannan; Lonati, Elena; Agrochão, Margarida; Thevelein, Johan M

    2010-02-16

    A novel concept in eukaryotic signal transduction is the use of nutrient transporters and closely related proteins as nutrient sensors. The action mechanism of these "transceptors" is unclear. The Pho84 phosphate transceptor in yeast transports phosphate and mediates rapid phosphate activation of the protein kinase A (PKA) pathway during growth induction. We have now identified several phosphate-containing compounds that act as nontransported signaling agonists of Pho84. This indicates that signaling does not require complete transport of the substrate. For the nontransported agonist glycerol-3-phosphate (Gly3P), we show that it is transported by two other carriers, Git1 and Pho91, without triggering signaling. Gly3P is a competitive inhibitor of transport through Pho84, indicating direct interaction with its phosphate-binding site. We also identified phosphonoacetic acid as a competitive inhibitor of transport without agonist function for signaling. This indicates that binding of a compound into the phosphate-binding site of Pho84 is not enough to trigger signaling. Apparently, signaling requires a specific conformational change that may be part of, but does not require, the complete transport cycle. Using Substituted Cysteine Accessibility Method (SCAM) we identified Phe(160) in TMD IV and Val(392) in TMD VIII as residues exposed with their side chain into the phosphate-binding site of Pho84. Inhibition of both transport and signaling by covalent modification of Pho84(F160C) or Pho84(V392C) showed that the same binding site is used for transport of phosphate and for signaling with both phosphate and Gly3P. Our results provide to the best of our knowledge the first insight into the molecular mechanism of a phosphate transceptor. PMID:20133652

  7. Phosphate separation and recovery from wastewater by novel electrodialysis.

    PubMed

    Zhang, Yang; Desmidt, Evelyn; Van Looveren, Arnaud; Pinoy, Luc; Meesschaert, Boudewijn; Van der Bruggen, Bart

    2013-06-01

    Stimulated by the depletion of phosphate resources, phosphate recovery systems have been studied in recent years. The use of struvite reactors has proven to be an effective phosphate recovery process. However, the struvite reactor effluent still consists of an excessive amount of phosphate that cannot be recovered nor can be directly discharged. In this study, selectrodialysis (SED) was used to improve the efficiency of phosphate recovery from a struvite reactor: SED was implemented in such a way that phosphate from the effluent of an USAB (upflow anaerobic sludge blanket) reactor was transferred to the recycled effluent of a struvite reactor. Prior to the experiments, synthetic water with chloride and phosphate was used to characterize the efficiency of SED for phosphate separation. Results indicate that SED was successful in concentrating phosphate from the feed stream. The initial current efficiency reached 72%, with a satisfying (9 mmol L(-1)) phosphate concentration. In the experiments with the anaerobic effluent as the phosphate source for enrichment of the effluent of the struvite reactor, the phosphate flux was 16 mmol m(-2) h(-1). A cost evaluation shows that 1 kWh electricity can produce 60 g of phosphate by using a full scale stack, with a desalination rate of 95% on the feed wastewater. Finally, a struvite precipitation experiment shows that 93% of phosphate can be recovered. Thus, an integrated SED-struvite reactor process can be used to improve phosphate recovery from wastewater. PMID:23651001

  8. Ureolytic phosphate precipitation from anaerobic effluents.

    PubMed

    Desmidt, E; Verstraete, W; Dick, J; Meesschaert, B D; Carballa, M

    2009-01-01

    In this work, the elimination of phosphate from industrial anaerobic effluents was evaluated at lab-scale. For that purpose, the ureolytic method previously developed for the precipitation of Ca(2 + ) from wastewater as calcite was adapted for the precipitation of phosphate as struvite. In the first part of the study, computer simulations using MAPLE and PHREEQC were performed to model phosphate precipitation from wastewater as struvite. The results obtained showed that relative high concentrations of ammonium and magnesium are needed to precipitate phosphate as struvite. The total molar concentrations ratio of Mg(2 + ):PO(4) (3-)-P:NH(4) (+) required to decrease PO(4) (3-)-P concentrations from 20 to 6 mg PO(4) (3-)-P/l at pH 8.4-8.5 was estimated on 4.6:1:8. In the second part of the study, lab-scale experiments with either synthetic wastewater or the anaerobic effluent from a vegetable processing industry were carried out in batch and continuous mode. Overall, the continuous operation at a hydraulic retention time (HRT) of 2.4 h and an added molar concentration [Mg(2 + )]:[PO(4) (3-)-P]:[NH(4) (+)] ratio of 1.6:1:2.3 resulted in a constant pH value in the reactor (around 8.5) and an efficient phosphate removal (>90%) to residual levels of 1-2 mg PO(4) (3-)-P/l. Different operational conditions, such as the initial phosphate concentration, HRT and the use of CaCl(2) or MgO instead of MgCl(2), were analysed and the performance of the reactor was satisfactory under a broad range of them. Yet, overall, optimal results (higher phosphate removal) were obtained with MgCl(2). PMID:19474493

  9. An autosomal glucose-6-phosphate dehydrogenase (hexose-6-phosphate dehydrogenase) polymorphism in human saliva.

    PubMed

    Tan, S G; Ashton, G C

    1976-01-01

    Glucose-6-phosphate dehydrogenase (hexose-6-phosphate dehydrogenase) from human saliva has been demonstrated by the zymogram technique. Three phenotypes were found. Family and population studies suggested that these phenotypes are the products of an autosomal locus with two alleles Sgd-1 and Sgd-2. PMID:950237

  10. COMPARATIVE KINETIC STUDIES OF PHOSPHATE-LIMITED GROWTH AND PHOSPHATE UPTAKE IN PHYTOPLANKTON IN CONTINUOUS CULTURE

    EPA Science Inventory

    A comparative kinetic study of phosphate-limited growth and phosphate uptake was carried out in chemostat cultures of Anabaena flos-aquae Lyng. Breb., Ankistrodesmus falcatus (Corda) Ralfs, Asterionella formosa Hass., Fragilaria crotonensis Kitt., and Microcystis sp. Lemm. For ea...

  11. Mechanism of glyceraldehyde-3-phosphate transfer from aldolase to glyceraldehyde-3-phosphate dehydrogenase.

    PubMed

    Kvassman, J; Pettersson, G; Ryde-Pettersson, U

    1988-03-01

    The catalytic interaction of glyceraldehyde-3-phosphate dehydrogenase with glyceraldehyde 3-phosphate has been examined by transient-state kinetic methods. The results confirm previous reports that the apparent Km for oxidative phosphorylation of glyceraldehyde 3-phosphate decreases at least 50-fold when the substrate is generated in a coupled reaction system through the action of aldolase on fructose 1,6-bisphosphate, but lend no support to the proposal that glyceraldehyde 3-phosphate is directly transferred between the two enzymes without prior release to the reaction medium. A theoretical analysis is presented which shows that the kinetic behaviour of the coupled two-enzyme system is compatible in all respects tested with a free-diffusion mechanism for the transfer of glyceraldehyde 3-phosphate from the producing enzyme to the consuming one. PMID:3350006

  12. Modulation of the interaction between aldolase and glycerol-phosphate dehydrogenase by fructose phosphates.

    PubMed

    Vértessy, B G; Orosz, F; Ovádi, J

    1991-06-24

    Kinetics of fructose-1,6-disphosphate aldolase (EC 4.1.2.13) catalyzed conversion of fructose phosphates was analyzed by coupling the aldolase reactions to the metabolically sequential enzyme, glycerol-3-phosphate dehydrogenase (EC 1.1.1.8), which interacts with aldolase. At low enzyme concentration poly(ethylene glycol) was added to promote complex formation of aldolase and glycerol-phosphate dehydrogenase resulting in a 3-fold increase in KM of fructose-1,6-bisphosphate and no change in Vmax. Kinetic parameters for fructose-1-phosphate conversion changed inversely upon complex formation: Vmax increased while KM remained unchanged. Gel penetration and ion-exchange chromatographic experiments showed positive modulation of the interaction of aldolase and dehydrogenase by fructose-1,6-bisphosphate. The dissociation constant of the heterologous enzyme complex decreased 10-fold in the presence of this substrate. Fructose-1-phosphate or dihydroxyacetone phosphate had no effect on the dissociation constant of the aldolase-dehydrogenase complex. In addition, titration of fluorescein-labelled glycerol-phosphate dehydrogenase with aldolase indicated that both fructose-1,6-bisphosphate and fructose-2,6-biphosphate enhanced the affinity of aldolase to glycerol-phosphate dehydrogenase. The results of the kinetic and binding experiments suggest that binding of the C-6 phosphate group of fructose-1,6-bisphosphate to aldolase complexed with dehydrogenase is sterically impeded while saturation of the C-6 phosphate group site increases the affinity of aldolase for dehydrogenase. The possible molecular mechanism of the fructose-1,6-bisphosphate modulated interaction is discussed. PMID:2065091

  13. Iron-based phosphate binders: do they offer advantages over currently available phosphate binders?

    PubMed Central

    Negri, Armando Luis; Ureña Torres, Pablo Antonio

    2015-01-01

    Increased cardiovascular morbidity and mortality has been associated with the hyperphosphatemia seen in patients with end-stage chronic kidney disease (CKD). Oral phosphate binders are prescribed in these patients to prevent intestinal absorption of dietary phosphate and reduce serum phosphate. In prospective observational cohorts they have shown to decrease all-cause and cardiovascular mortality risk. Different problems have been associated with currently available phosphate binders as positive calcium balance and impaired outcomes with calcium-based phosphate binders or increased costs with non-calcium-based phosphate binders. Iron-based phosphate binders represent a new class of phosphate binders. Several iron-based phosphate binders have undergone testing in clinical trials. Ferric citrate (JTT-751) and sucroferric oxyhydroxide (PA21) are the two iron-based binders that have passed to the clinical field after being found safe and effective in decreasing serum phosphate. Iron from ferric citrate is partially absorbed compared to sucroferric oxyhydroxide. Ferric citrate usage could result in an important reduction in erythropoiesis-stimulating agent (ESA) and IV iron usage, resulting in significant cost savings. Sucroferric oxyhydroxide was effective in lowering serum phosphorus in dialysis patients with similar efficacy to sevelamer carbonate, but with lower pill burden, and better adherence. Ferric citrate may be more suited for the treatment of chronic hyperphosphatemia in CKD patients requiring iron supplements but its use may have been hampered by potential aluminum overload, as citrate facilitates its absorption; sucroferric oxyhydroxide may be more suited for hyperphosphatemic CKD patients not requiring iron supplementation, with low pill burden. PMID:25815172

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

    PubMed

    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. PMID:25345061

  15. How versatile are inositol phosphate kinases?

    PubMed Central

    Shears, Stephen B

    2004-01-01

    This review assesses the extent and the significance of catalytic versatility shown by several inositol phosphate kinases: the inositol phosphate multikinase, the reversible Ins(1,3,4) P (3)/Ins(3,4,5,6) P (4) kinase, and the kinases that synthesize diphosphoinositol polyphosphates. Particular emphasis is placed upon data that are relevant to the situation in vivo. It will be shown that catalytic promiscuity towards different inositol phosphates is not typically an evolutionary compromise, but instead is sometimes exploited to facilitate tight regulation of physiological processes. This multifunctionality can add to the complexity with which inositol signalling pathways interact. This review also assesses some proposed additional functions for the catalytic domains, including transcriptional regulation, protein kinase activity and control by molecular 'switching', all in the context of growing interest in 'moonlighting' (gene-sharing) proteins. PMID:14567754

  16. Calcium phosphate cement scaffolds with PLGA fibers.

    PubMed

    Vasconcellos, Letícia Araújo; dos Santos, Luís Alberto

    2013-04-01

    The use of calcium phosphate-based biomaterials has revolutionized current orthopedics and dentistry in repairing damaged parts of the skeletal system. Among those biomaterials, the cement made of hydraulic grip calcium phosphate has attracted great interest due to its biocompatibility and hardening "in situ". However, these cements have low mechanical strength compared with the bones of the human body. In the present work, we have studied the attainment of calcium phosphate cement powders and their addition to poly (co-glycolide) (PLGA) fibers to increase mechanical properties of those cements. We have used a new method that obtains fibers by dripping different reagents. PLGA fibers were frozen after lyophilized. With this new method, which was patented, it was possible to obtain fibers and reinforcing matrix which furthered the increase of mechanical properties, thus allowing the attainment of more resistant materials. The obtained materials were used in the construction of composites and scaffolds for tissue growth, keeping a higher mechanical integrity. PMID:23827539

  17. Structural basis for phosphatidylinositol-phosphate biosynthesis

    PubMed Central

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

    2015-01-01

    Phosphatidylinositol is critical for intracellular signalling and anchoring of carbohydrates and proteins to outer cellular membranes. The defining step in phosphatidylinositol biosynthesis is catalysed by CDP-alcohol phosphotransferases, transmembrane enzymes that use CDP-diacylglycerol as donor substrate for this reaction, and either inositol in eukaryotes or inositol phosphate in prokaryotes as the acceptor alcohol. Here we report the structures of a related enzyme, the phosphatidylinositol-phosphate synthase from Renibacterium salmoninarum, with and without bound CDP-diacylglycerol to 3.6 and 2.5 Å resolution, respectively. These structures reveal the location of the acceptor site, and the molecular determinants of substrate specificity and catalysis. Functional characterization of the 40%-identical ortholog from Mycobacterium tuberculosis, a potential target for the development of novel anti-tuberculosis drugs, supports the proposed mechanism of substrate binding and catalysis. This work therefore provides a structural and functional framework to understand the mechanism of phosphatidylinositol-phosphate biosynthesis. PMID:26510127

  18. Phosphorylation of Kraft fibers with phosphate esters.

    PubMed

    Shi, Ying; Belosinschi, Dan; Brouillette, François; Belfkira, Ahmed; Chabot, Bruno

    2014-06-15

    Phosphate esters, derived from two different long-chain aliphatic alcohols, were used as phosphorylating reagents for Kraft pulp fibers. High phosphorus contents and almost non-degraded fibers were obtained by following this pathway. The phosphorylation efficiency was influenced by the alkyl chain length of PEs since the phosphorus content in modified fibers was higher for the shorter chain reagent. Due to the heterogeneous reaction environment, the amount of grafted phosphorus was found to be almost three times higher at the surface than in the bulk of the fibers. Analyses also indicated that the phosphorus was bonded to fibers as a phosphate-like structure. Furthermore, the situation seemed to be different for the fiber surface where significant amounts of phosphorus were present in more complex structures like pyrophosphate or even oligo-phosphate. PMID:24721058

  19. Structural basis for phosphatidylinositol-phosphate biosynthesis.

    PubMed

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

    2015-01-01

    Phosphatidylinositol is critical for intracellular signalling and anchoring of carbohydrates and proteins to outer cellular membranes. The defining step in phosphatidylinositol biosynthesis is catalysed by CDP-alcohol phosphotransferases, transmembrane enzymes that use CDP-diacylglycerol as donor substrate for this reaction, and either inositol in eukaryotes or inositol phosphate in prokaryotes as the acceptor alcohol. Here we report the structures of a related enzyme, the phosphatidylinositol-phosphate synthase from Renibacterium salmoninarum, with and without bound CDP-diacylglycerol to 3.6 and 2.5 Å resolution, respectively. These structures reveal the location of the acceptor site, and the molecular determinants of substrate specificity and catalysis. Functional characterization of the 40%-identical ortholog from Mycobacterium tuberculosis, a potential target for the development of novel anti-tuberculosis drugs, supports the proposed mechanism of substrate binding and catalysis. This work therefore provides a structural and functional framework to understand the mechanism of phosphatidylinositol-phosphate biosynthesis. PMID:26510127

  20. Structural basis for phosphatidylinositol-phosphate biosynthesis

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  1. Monte Carlo simulations of phosphate polyhedron connectivity in glasses

    SciTech Connect

    ALAM,TODD M.

    2000-01-01

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

  2. Monte Carlo Simulations of Phosphate Polyhedron Connectivity in Glasses

    SciTech Connect

    ALAM,TODD M.

    1999-12-21

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

  3. The inhibition of mitochondrial dicarboxylate transport by inorganic phosphate, some phosphate esters and some phosphonate compounds.

    PubMed

    Johnson, R N; Chappell, J B

    1974-02-01

    1. P(i) competitively inhibited succinate oxidation by intact uncoupled mitochondria in the presence of sufficient N-ethylmaleimide to block the phosphate carrier, with a K(i) of 2.5mm. 2. Of a large number of phosphate esters and phosphonate compounds, phenyl phosphate and phenylphosphonate were found to inhibit competitively uncoupled succinate oxidation by intact but not broken mitochondria. By comparison, benzoate was a relatively weak competitive inhibitor of succinate oxidation by intact mitochondria but a relatively potent inhibitor of succinate dehydrogenase. 3. Phenyl phosphate and phenylphosphonate were non-penetrant, and inhibited P(i)-dependent swelling of mitochondria suspended in isosmolar ammonium malate in a manner non-competitive with P(i). The inhibitors did not affect mitochondrial swelling when tested with P(i) alone. 4. It is concluded that: (i) phenyl phosphate and phenylphosphonate behaved as non-penetrant analogues of P(i), since their inhibitory properties were in strict contrast with those of benzoate; (ii) phenyl phosphate and phenylphosphonate interacted with the dicarboxylate carrier but not with the phosphate carrier; (iii) P(i) was effective as a competitive inhibitor of succinate oxidation because of its being either an alternative substrate for the dicarboxylate carrier or competitive with succinate for the intramitochondrial cations as proposed by Harris & Manger (1968). PMID:4822730

  4. Xenobiotic conjugation with phosphate - a metabolic rarity.

    PubMed

    Mitchell, Stephen C

    2016-08-01

    1. Although not unknown, the conjugation of a xenobiotic with phosphate appears a rarity amongst the routes available for foreign compound metabolism. This is especially true in mammals and may be somewhat surprising as conjugation with sulphate, a seemingly similar moiety, is commonplace. 2. Information from the literature, where xenobiotic phosphate conjugates have been described or suggested, has been collated and presented in this article. By bringing together this diverse material, hopefully interest will be generated in this unusual xenobiotic reaction, and perhaps further research undertaken to better understand and delineate the reasons for its relative absence from the xenobiotic scene. PMID:26611118

  5. Calcium phosphate ceramics in drug delivery

    NASA Astrophysics Data System (ADS)

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

    2011-04-01

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

  6. Pumpable/injectable phosphate-bonded ceramics

    DOEpatents

    Singh, Dileep; Wagh, Arun S.; Perry, Lamar; Jeong, Seung-Young

    2001-01-01

    A pumpable ceramic composition is provided comprising an inorganic oxide, potassium phosphate, and an oxide coating material. Also provided is a method for preparing pumpable ceramic-based waste forms comprising selecting inorganic oxides based on solubility, surface area and morphology criteria; mixing the selected oxides with phosphate solution and waste to form a first mixture; combining an additive to the first mixture to create a second mixture; adding water to the second mixture to create a reactive mixture; homogenizing the reactive mixture; and allowing the reactive mixture to cure.

  7. Potentially Prebiotic Syntheses of Condensed Phosphates

    NASA Technical Reports Server (NTRS)

    Keefe, Anthony D.; Miller, Stanley L.

    1996-01-01

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

  8. Evaluation of Intestinal Phosphate Binding to Improve the Safety Profile of Oral Sodium Phosphate Bowel Cleansing

    PubMed Central

    Robijn, Stef; Vervaet, Benjamin A.; D’Haese, Patrick C.; Verhulst, Anja

    2015-01-01

    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. PMID:25790436

  9. Phosphate application to firing range soils for Pb immobilization: the unclear role of phosphate.

    PubMed

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

    2007-06-01

    Phosphate treatment has emerged as a widely accepted approach to immobilize Pb in contaminated soils and waste media, relying on the formation of the highly insoluble mineral pyromorphite as solubility-controlling phase for Pb. As such, phosphate treatment has been proposed as a Best Management Practice (BMP) for firing ranges where Pb occurs in its metallic forms and several other phases (carbonates, oxides). While pyromorphite thermodynamically has the potential to control Pb solubility at low levels, its formation is kinetically controlled by pH, the solubility of the phosphate source, and the solubility of Pb species. Treatability studies have shown that excess quantities of soluble and acidic phosphate sources, such as phosphoric acid, are necessary for successful in situ treatment. Even under these conditions, Extended X-ray Absorption Fine Structure (EXAFS), the only reliable method to identify and quantify Pb speciation, showed that Pb conversion to pyromorphite in in situ treated soils was less than 45% after 32 months. Furthermore, the use of lime (CaO) to restore soil pH in acidified soil treatments inhibited further conversion. Additionally, phosphate treatment is known to reduce bioavailability through pyromorphite formation in the intestinal tract, and the phytoaccumulation of Pb; both desirable effects for Pb-impacted areas. Given the costs of phosphate treatment, the use of biogenic phosphate sources, such as bone meal, may be a more environmentally sustainable approach toward this end. In the many studies focusing on phosphate treatment, the attendant P leaching and eutrophication have been largely overlooked, along with other issues such as the enhanced leaching of oxyanionic contaminants, such as Se, As and W. The success and sustainability of applying phosphate as a BMP in firing range soils therefore remain questionable. PMID:17360110

  10. Attenuation of Phosphate Starvation Responses by Phosphite in Arabidopsis1

    PubMed Central

    Ticconi, Carla A.; Delatorre, Carla A.; Abel, Steffen

    2001-01-01

    When inorganic phosphate is limiting, Arabidopsis has the facultative ability to metabolize exogenous nucleic acid substrates, which we utilized previously to identify insensitive phosphate starvation response mutants in a conditional genetic screen. In this study, we examined the effect of the phosphate analog, phosphite (Phi), on molecular and morphological responses to phosphate starvation. Phi significantly inhibited plant growth on phosphate-sufficient (2 mm) and nucleic acid-containing (2 mm phosphorus) media at concentrations higher than 2.5 mm. However, with respect to suppressing typical responses to phosphate limitation, Phi effects were very similar to those of phosphate. Phosphate starvation responses, which we examined and found to be almost identically affected by both anions, included changes in: (a) the root-to-shoot ratio; (b) root hair formation; (c) anthocyanin accumulation; (d) the activities of phosphate starvation-inducible nucleolytic enzymes, including ribonuclease, phosphodiesterase, and acid phosphatase; and (e) steady-state mRNA levels of phosphate starvation-inducible genes. It is important that induction of primary auxin response genes by indole-3-acetic acid in the presence of growth-inhibitory Phi concentrations suggests that Phi selectively inhibits phosphate starvation responses. Thus, the use of Phi may allow further dissection of phosphate signaling by genetic selection for constitutive phosphate starvation response mutants on media containing organophosphates as the only source of phosphorus. PMID:11706178

  11. Enteral administration of monosodium phosphate, monopotassium phosphate and monocalcium phosphate for the treatment of hypophosphataemia in lactating dairy cattle.

    PubMed

    Idink, M J; Grünberg, W

    2015-05-01

    Hypohosphataemia is a frequent finding in early lactating and anorectic dairy cows. Sodium phosphate is commonly used for oral phosphorus (P) supplementation, although other phosphate salts may present useful treatment alternatives. Objectives of this study were to compare the efficacy of monopotassium phosphate (KH2PO4) and monocalcium phosphate (Ca(H2PO4)2) to monosodium phosphate (NaH2PO4) in P-depleted cows. Furthermore, the effect of concentrated NaH2PO4 on the reticular groove reflex was studied. Six healthy but P-depleted dairy cows underwent four treatments in randomised order. Treatments consisted of intraruminal administration of NaH2PO4, KH2PO4 and Ca(H2PO4)2 providing the equivalent of 60 g P. A fourth treatment consisting of concentrated NaH2PO4 combined with acetaminophen as a marker substance was administered orally to determine whether the reticular groove reflex could be induced. Intraruminal administration of NaH2PO4 and KH2PO4 resulted in similar increases in plasma Pi concentrations ([Pi]) while intraruminal Ca(H2PO4)2 resulted in lower increases in plasma [Pi]. Oral and intraruminal administration of NaH2PO4 resulted in similar times to peak plasma [Pi] and acetaminophen concentration, indicating that concentrated NaH2PO4 administered orally did not trigger the reticular groove reflex. These results suggest that oral administration of KH2PO4 is equally effective as NaH2PO4. Oral administration of Ca(H2PO4)2 in contrast has a less pronounced effect on the plasma [Pi]. PMID:25721509

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

    MedlinePlus

    ... Clayton PT, Baumgartner MR, Steinmann B, Bast T, Wolf NI, Zschocke J. Pyridoxal 5'-phosphate may be ... Clayton PT, Baumgartner MR, Steinmann B, Bast T, Wolf NI, Zschocke J. Pyridoxal 5'-phosphate may be ...

  13. Regulation of hormone-sensitive renal phosphate transport.

    PubMed

    Gattineni, Jyothsna; Friedman, Peter A

    2015-01-01

    Phosphate is essential for growth and maintenance of the skeleton and for generating high-energy phosphate compounds. Evolutionary adaptation to high dietary phosphorous in humans and other terrestrial vertebrates involves regulated mechanisms assuring the efficient renal elimination of excess phosphate. These mechanisms prominently include PTH, FGF23, and Vitamin D, which directly and indirectly regulate phosphate transport. Disordered phosphate homeostasis is associated with pathologies ranging from kidney stones to kidney failure. Chronic kidney disease results in hyperphosphatemia, an elevated calcium×phosphate product with considerable morbidity and mortality, mostly associated with adverse cardiovascular events. This chapter highlights recent findings and insights regarding the hormonal regulation of renal phosphate transport along with imbalances of phosphate balance due to acquired or inherited diseases states. PMID:25817872

  14. Insights from Genetic Disorders of Phosphate Homeostasis

    PubMed Central

    Christov, Marta; Jüppner, Harald

    2013-01-01

    The molecular identification and characterization of genetic defects leading to a number of rare inherited or acquired disorders affecting phosphate homeostasis has added tremendous detail to our understanding of the regulation of phosphate balance. The identification of the key phosphate-regulating hormone, fibroblast growth factor 23 (FGF23), as well as other molecules that control its production, such as the glycosyltransferase GALNT3, the endopeptidase PHEX and the matrix protein DMP1, and molecules that function as downstream effectors of FGF23, such as the longevity factor Klotho and the phosphate transporters NPT2a and NPT2c, has permitted us to understand the elegant and complex interplay that exists between the kidneys, bone, parathyroid, and gut. Such insights from genetic disorders have allowed not only the design of potent targeted therapies for some of these rare genetic disorders, such as using anti-FGF23 antibodies for treatment of X-linked hypophosphatemic rickets, but also have led to clinically relevant observations related to the dysregulation of mineral ion homeostasis in chronic kidney disease. Thus, we are able to leverage our knowledge of rare human disorders affecting only few individuals, to understand and potentially treat disease processes that affect millions of patients. PMID:23465501

  15. 21 CFR 137.175 - Phosphated flour.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Phosphated flour. 137.175 Section 137.175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized Cereal Flours...

  16. An Experiment to Quantitate Organically Bound Phosphate.

    ERIC Educational Resources Information Center

    Palmer, Richard E.

    1985-01-01

    Describes quick and easy experiments that yield quantitative information on a variety of levels, emphasize the concept of experimental controls, and integrate the experimental with the theoretical using the organic phosphates as the experimental system. Background information, list of materials needed, and procedures used are included. (JN)

  17. Interaction of cadmium with phosphate on goethite

    SciTech Connect

    Venema, P.; Hiemstra, T.; Riemsdijk, W.H. van

    1997-08-01

    Interactions between different ions are of importance in understanding chemical processes in natural systems. In this study simultaneous adsorption of phosphate and cadmium on goethite is studied in detail. The charge distribution (CD)-multisite complexation (MUSIC) model has been successful in describing extended data sets of cadmium adsorption and phosphate adsorption on goethite. In this study, the parameters of this model for these two data sets were combined to describe a new data set of simultaneous adsorption of cadmium and phosphate on goethite. Attention is focused on the surface speciation of cadmium. With the extra information that can be obtained from the interaction experiments, the cadmium adsorption model is refined. For a perfect description of the data, the singly coordinated surface groups at the 110 face of goethite were assumed to form both monodentate and bidentate surface species with cadmium. The CD-MUSIC model is able to describe data sets of both simultaneous and single adsorption of cadmium and phosphate with the same parameters. The model calculations confirmed the idea that only singly coordinated surface groups are reactive for specific ion binding.

  18. 21 CFR 582.5217 - Calcium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Calcium phosphate. 582.5217 Section 582.5217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  19. 21 CFR 182.8217 - Calcium phosphate.

    Code of Federal Regulations, 2010 CFR

    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 HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8217...

  20. 21 CFR 582.5217 - Calcium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Calcium phosphate. 582.5217 Section 582.5217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  1. 21 CFR 582.5301 - Ferric phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ferric phosphate. 582.5301 Section 582.5301 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  2. 21 CFR 182.8217 - Calcium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium phosphate. 182.8217 Section 182.8217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8217...

  3. 21 CFR 582.5301 - Ferric phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ferric phosphate. 582.5301 Section 582.5301 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  4. 21 CFR 582.5217 - Calcium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Calcium phosphate. 582.5217 Section 582.5217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  5. 21 CFR 182.8217 - Calcium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Calcium phosphate. 182.8217 Section 182.8217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8217...

  6. 21 CFR 182.8217 - Calcium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Calcium phosphate. 182.8217 Section 182.8217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8217...

  7. 21 CFR 582.5301 - Ferric phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ferric phosphate. 582.5301 Section 582.5301 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  8. 21 CFR 582.5301 - Ferric phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ferric phosphate. 582.5301 Section 582.5301 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  9. 21 CFR 582.5217 - Calcium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Calcium phosphate. 582.5217 Section 582.5217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  10. IN-SITU MINING OF PHOSPHATE ORES

    SciTech Connect

    H. El-Shall; R. Stana; A. El-Midany; S. Malekzadah

    2004-12-17

    Presently the mining of Florida phosphate requires the movement of over a 100-ton of materials (overburden, sand, clay) for every ton of phosphate concentrate recovered. Not only is this energy intensive, but it also causes significant stress on the environment. In 2003, the Department of Energy solicited ideas for innovative mining ideas that could significantly improve the efficiency of mining. An award was made to the University of Florida Engineering Research Center to evaluate the in situ mining of phosphates using an aqueous CO{sub 2} solution. Tests were carried out in a 15.2 cm (6-inch) diameter column, 1.83 meter (6 feet) long at pressures up to 117.2 kg/cm{sup 2} (40 psi). Results to date demonstrate that initially the MgO is leached from the ore and then the phosphate. While the tests are continuing, so far they have not demonstrated P{sub 2}O{sub 5} concentrations that are economically attractive.

  11. TUCS/phosphate mineralization of actinides

    SciTech Connect

    Nash, K.L.

    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.

  12. Psoriatic therapeutics and glucose-6-phosphate dehydrogenase.

    PubMed

    Cotton, D W; van Rossum, E

    1975-01-01

    The inhibitory effects of various agents on the enzyme glucose-6-phosphate dehydrogenase have been studied in vitro. Stress is laid on the calculation of kinetic parameters such as true K-I values. The most active inhibitor was methotrexate, closely followed by cGMP. The increase in inhibitory activity after incubation of methotrexate with liver slices is discussed. PMID:167665

  13. Phosphates in some missouri refractory clays

    USGS Publications Warehouse

    Hall, R.B.; Foord, E.E.; Keller, D.J.; Keller, W.D.

    1997-01-01

    This paper describes in detail phosphate minerals occurring in refractory clays of Missouri and their effect on the refractory degree of the clays. The minerals identified include carbonate-fluorapatite (francolite), crandallite, goyazite, wavellite, variscite and strengite. It is emphasized that these phosphates occur only in local isolated concentrations, and not generally in Missouri refractory clays. The Missouri fireclay region comprises 2 districts, northern and southern, separated by the Missouri River In this region, clay constitutes a major part of the Lower Pennsylvanian Cheltenham Formation. The original Cheltenham mud was an argillic residue derived from leaching and dissolution of pre-Pennsylvanian carbonates. The mud accumulated on a karstic erosion surface truncating the pre-Cheltenham rocks. Fireclays of the northern district consist mainly of poorly ordered kaolinite, with variable but minor amounts of illite, chlorite and fine-grained detrital quartz. Clays of the southern district were subjected to extreme leaching that produced well-ordered kaolinite flint clays. Local desilication formed pockets of diaspora, or more commonly, kaolinite, with oolite-like nubs or burls of diaspore ("burley" clay). The phosphate-bearing materials have been studied by X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectral analysis (SEM-EDS) and chemical analysis. Calcian goyazite was identified in a sample of diaspore, and francolite in a sample of flint clay. A veinlet of wavellite occurs in flint clay at one locality, and a veinlet of variscite-strengite at another locality. The Missouri flint-clay-hosted francolite could not have formed in the same manner as marine francolite The evidence suggests that the Cheltenham francolite precipitated from ion complexes in pore water nearly simultaneously with crystallization of kaolinite flint clay from an alumina-silica gel. Calcian goyazite is an early diagenetic addition to its diaspore host

  14. Analysis of phosphate esters in plant material

    PubMed Central

    Isherwood, F. A.; Barrett, F. C.

    1967-01-01

    1. A critical study was made of the quantitative extraction of nucleotide and sugar phosphates from plant tissue by either boiling aqueous ethanol or cold trichloroacetic acid. The effect of the extraction technique on the inactivation of the enzymes in the plant tissue and the possibility of adsorption of the phosphate esters on the cell wall were especially considered. 2. In the recommended method the plant tissue was frozen in liquid nitrogen, ground to a powder and then blended with cold aqueous trichloroacetic acid containing 8-hydroxyquinoline to prevent adsorption. 3. The extract contained large amounts of trichloroacetic acid, cations, chloride, sugars, amino acids, hydroxy organic acids, phytic acid, orthophosphoric acid and high-molecular-weight material including some phosphorus-containing compounds. All of these were removed as they were liable to interfere with the chromatographic or enzymic assay of the individual nucleotide or sugar phosphates. 4. The procedure was as follows: the last traces of trichloroacetic acid were extracted with ether after the solution had been passed through a column of Dowex AG 50 in the hydrogen form to remove all cations. High-molecular-weight compounds were removed by ultrafiltration and low-molecular-weight solutes by a two-stage chromatography on cellulose columns with organic solvents. In the first stage, sugars, amino acids, chloride and phytic acid were separated by using a basic solvent (propan-1-ol–water–aqueous ammonia) and, in the second stage, the organic acids and orthophosphoric acid were separated by using an acidic solvent (di-isopropyl ether–formic acid–2-methylpropan-2-ol–water). The final solution of nucleotide and sugar phosphates was substantially free from other solutes and was suitable for the detection of individual phosphate esters by either chromatography or enzymic assay. 5. The recovery of d-glucose 6-phosphate or adenosine 5′-triphosphate added to a trichloroacetic acid extract

  15. Hexose phosphate synthetase from Methylococcus capsulatus makes d-arabino-3-hexulose phosphate

    PubMed Central

    Kemp, M. B.

    1974-01-01

    The product of the reaction catalysed by hexose phosphate synthase prepared from Methylococcus capsulatus was dephosphorylated and the sugar moiety purified. The sugar and derivatives were compared by various chromatographic and other methods with authentic samples of allulose (psicose), d-erythro-l-glycero-3-hexulose and d-erythro-d-glycero-3-hexulose. The sugar is not allulose, as was previously thought on the basis of less extensive evidence (Kemp & Quayle, 1966), but is in fact d-erythro-l-glycero-3-hexulose (d-arabino-3-hexulose). This identification is consistent with recent studies which have shown that hexose phosphate synthase catalyses the condensation of formaldehyde with d-ribulose 5-phosphate rather than with d-ribose 5-phosphate (Kemp, 1972). PMID:4463938

  16. The low temperature formation of octacalcium phosphate

    NASA Astrophysics Data System (ADS)

    Graham, Stephan; Brown, Paul W.

    1993-09-01

    The low temperature formation of octacalcium phosphate (Ca 8(HPO 4) 2(PO 4) 4·5H 2O) was investigated. Octacalcium phosphate (OCP) was formed by the hydrolysis of α-tricalcium phosphate (α-TCP), and by reaction between monocalcium phosphate monohydrate (MCPM) and tetracalcium phosphate (TetCP). Relationships between phase formation, microstructural evolution, and variations in solution chemistry were examined. Hydrolysis of α-TCP to form OCP occurs more rapidly at elevated temperatures. At the highest temperature studied, 70°C, initial precipitation of OCP occurs in about one hour, but its inevitable hydrolysis to the more stable HAp phase takes place over several days. At room temperature, nearly three days are required to initiate OCP formation, yet remains a final product phase for well over a period of months. When the initial solution pH is less than 7, pure phase OCP is the final product, while HAp forms when initial pH values are higher than this. Furthermore, OCP precipitates faster at the highest initial pH values where its formation is observed. OCP formation by reaction between MCPM and TetCP is also dependent on temperature and time of reaction. For temperatures between 40 and 55°C and at reasonable times (less than four days) the product is phase pure OCP. After that time, inevitable hydrolysis of the OCP product to HAp occurs. Between 30 and 40°C, DCPD (CaHPO 4·2H 2O) is simultaneously present with OCP, and below 30°C, HAp and DCPD coexist within this aforementioned time span. Conversely, between 55 and 60°C, DCP (CaHPO 4) and OCP are the product phases (in the allowed time of reaction, before the eventual degradation of OCP), and above 60°C HAp and DCP are the final products.

  17. 40 CFR 422.60 - Applicability; description of the sodium phosphates subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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....

  18. 40 CFR 422.60 - Applicability; description of the sodium phosphates subcategory.

    Code of Federal Regulations, 2010 CFR

    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....

  19. 40 CFR 422.60 - Applicability; description of the sodium phosphates subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 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....

  20. 40 CFR 422.60 - Applicability; description of the sodium phosphates subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 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....

  1. Tetrathiafulvalene diindolylquinoxaline: a dual signaling anion receptor with phosphate selectivity†

    PubMed Central

    Bejger, Christopher; Park, Jung Su; Silver, Eric S.; Sessler, Jonathan L.

    2011-01-01

    Incorporation of tetrathiafulvalene into the backbone of a known neutral phosphate receptor, diindolylquinoxaline, yields a dual optical-electrochemical chemosensor for dihydrogen phosphate that functions in dichloromethane. This system shows selectivity for dihydrogen phosphate over other small anions and can be used to detect the presence of this analyte via fluorescence quenching or cyclic voltammetry. PMID:20856940

  2. Substitution of calcium by strontium within selected calcium phosphates

    NASA Astrophysics Data System (ADS)

    Rokita, E.; Hermes, C.; Nolting, H.-F.; Ryczek, J.

    1993-06-01

    Sr incorporation in the molecules of amorphous calcium phosphate, apatitic tricalcium phosphate, hydroxyapatite, octacalcium phosphate and dicalcium phosphate dihydrate was investigated. The concentration of Sr ranged from 225 to 1010 μ g / g, i.e. it overlapped with the physiological range of Sr concentrations in human bone. The leading experimental technique was extended X-ray absorption fine structure (EXAFS) at the Sr K edge. Results of these studies demonstrated the following: (1) Sr incorporation in the calcium phosphates is compound-dependent, (2) the coordination of incorporated Sr atoms in the Ca-P molecules is similar to that of Ca atoms, but interatomic distances are ≈0.015 nm larger, (3) in apatitic tricalcium phosphate, hydroxyapatite and octacalcium phosphate lattices Sr atoms may occupy selected Ca sites, which was not the case for dicalcium phosphate dihydrate, (4) in the apatite lattice Sr atoms are coordinated by 6 PO 4 tetrahedrals and (5) EXAFS spectra at the K edge of the incorporated Sr may be used to distinguish the structures of amorphous calcium phosphate, dicalcium phosphate dihydrate as well as apatite and its derivatives (apatitic tricalcium phosphate, octacalcium phosphate).

  3. Kinetic Characterization of Spinach Leaf Sucrose-Phosphate Synthase 1

    PubMed Central

    Amir, Jacob; Preiss, Jack

    1982-01-01

    The spinach (Spinacia oleracea) leaf sucrose-phosphate synthase was partially purified via DEAE-cellulose chromatography, and its kinetic properties were studied. Fructose-6-phosphate saturation curves were sigmoidal, while UDPglucose saturation curves were hyperbolic. At subsaturating concentrations of fructose-6-phosphate, 1,5 anhydroglucitol-6-phosphate had a stimulatory effect on enzyme activity, suggesting multiple and interacting fructose-6-phosphate sites on sucrose-phosphate synthase. The concentrations required for 50% of maximal activity were 3.0 millimolar and 1.3 millimolar, respectively, for fructose-6-phosphate and UDPglucose. The enzyme was not stimulated by divalent cations. Inorganic phosphate proved to be a potent inhibitor, particularly at low concentrations of substrate. Phosphate inhibition was competitive with UDPglucose, and its Ki was determined to be 1.75 millimolar. Sucrose phosphate, the product of the reaction, was also shown to be a competitive inhibitor towards UDPglucose concentration and had Ki of 0.4 millimolar. The kinetic results suggest that spinach leaf sucrose-phospahte synthase is a regulatory enzyme and that its activity is modulated by the concentrations of phosphate, fructose-6-phosphate, and UDPglucose occurring in the cytoplasm of the leaf cell. PMID:16662338

  4. 21 CFR 862.1720 - Triose phosphate isomerase test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... isomerase test system is a device intended to measure the activity of the enzyme triose phosphate isomerase in erythrocytes (red blood cells). Triose phosphate isomerase is an enzyme important in glycolysis... this device are used in the diagnosis and treatment of congenital triose phosphate isomerase...

  5. 21 CFR 862.1720 - Triose phosphate isomerase test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... isomerase test system is a device intended to measure the activity of the enzyme triose phosphate isomerase in erythrocytes (red blood cells). Triose phosphate isomerase is an enzyme important in glycolysis... this device are used in the diagnosis and treatment of congenital triose phosphate isomerase...

  6. 21 CFR 862.1720 - Triose phosphate isomerase test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... isomerase test system is a device intended to measure the activity of the enzyme triose phosphate isomerase in erythrocytes (red blood cells). Triose phosphate isomerase is an enzyme important in glycolysis... this device are used in the diagnosis and treatment of congenital triose phosphate isomerase...

  7. 21 CFR 862.1720 - Triose phosphate isomerase test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... isomerase test system is a device intended to measure the activity of the enzyme triose phosphate isomerase in erythrocytes (red blood cells). Triose phosphate isomerase is an enzyme important in glycolysis... this device are used in the diagnosis and treatment of congenital triose phosphate isomerase...

  8. 21 CFR 862.1720 - Triose phosphate isomerase test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... isomerase test system is a device intended to measure the activity of the enzyme triose phosphate isomerase in erythrocytes (red blood cells). Triose phosphate isomerase is an enzyme important in glycolysis... this device are used in the diagnosis and treatment of congenital triose phosphate isomerase...

  9. 40 CFR 721.10302 - Zinc ammonium phosphate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Zinc ammonium phosphate (generic). 721... Substances § 721.10302 Zinc ammonium phosphate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as zinc ammonium phosphate (PMN...

  10. 40 CFR 721.10302 - Zinc ammonium phosphate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Zinc ammonium phosphate (generic). 721... Substances § 721.10302 Zinc ammonium phosphate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as zinc ammonium phosphate (PMN...

  11. 40 CFR 721.10302 - Zinc ammonium phosphate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Zinc ammonium phosphate (generic). 721... Substances § 721.10302 Zinc ammonium phosphate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as zinc ammonium phosphate (PMN...

  12. 40 CFR 721.643 - Ethoxylated alcohol, phosphated, amine salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ethoxylated alcohol, phosphated, amine... 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...

  13. 40 CFR 721.643 - Ethoxylated alcohol, phosphated, amine salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ethoxylated alcohol, phosphated, amine... 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...

  14. 40 CFR 721.643 - Ethoxylated alcohol, phosphated, amine salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Ethoxylated alcohol, phosphated, amine... 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...

  15. 21 CFR 522.1244 - Levamisole phosphate injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Levamisole phosphate injection. 522.1244 Section... § 522.1244 Levamisole phosphate injection. (a) Specifications. Each milliliter of sterile aqueous solution contains levamisole phosphate equivalent to 136.5 or 182 milligrams of levamisole...

  16. 21 CFR 522.1883 - Prednisolone sodium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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...

  17. 40 CFR 721.3080 - Substituted phosphate ester (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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...

  18. Determination of Phosphates by the Gravimetric Quimociac Technique

    ERIC Educational Resources Information Center

    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…

  19. 21 CFR 520.1804 - Piperazine phosphate capsules.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Piperazine phosphate capsules. 520.1804 Section... phosphate capsules. (a) Specifications. Each capsule contains 120, 300, or 600 milligrams of piperazine phosphate monohydrate. (b) Sponsor. See No. 051311 in § 510.600(c) of this chapter. (c) Conditions of...

  20. 21 CFR 182.6215 - Monobasic calcium phosphate.

    Code of Federal Regulations, 2010 CFR

    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....

  1. 21 CFR 582.6215 - Monobasic calcium phosphate.

    Code of Federal Regulations, 2010 CFR

    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....

  2. 21 CFR 582.5697 - Riboflavin-5-phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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...

  3. 21 CFR 182.6215 - Monobasic calcium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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....

  4. 21 CFR 520.1804 - Piperazine phosphate capsules.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Piperazine phosphate capsules. 520.1804 Section... phosphate capsules. (a) Specifications. Each capsule contains 120, 300, or 600 milligrams of piperazine phosphate monohydrate. (b) Sponsor. See No. 051311 in § 510.600(c) of this chapter. (c) Conditions of...

  5. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ammonium phosphate, monobasic. 184.1141a Section... SAFE Listing of Specific Substances Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic (NH4H2PO4, CAS Reg. No. 7722-76-1) is manufactured by reacting ammonia...

  6. 40 CFR 721.10046 - Polyaromatic amine phosphate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyaromatic amine phosphate (generic... Specific Chemical Substances § 721.10046 Polyaromatic amine phosphate (generic). (a) Chemical substance and... amine phosphate (PMN P-02-747) is subject to reporting under this section for the significant new...

  7. 21 CFR 522.1244 - Levamisole phosphate injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Levamisole phosphate injection. 522.1244 Section... § 522.1244 Levamisole phosphate injection. (a) Specifications. Each milliliter of sterile aqueous solution contains levamisole phosphate equivalent to 136.5 or 182 milligrams of levamisole...

  8. 40 CFR 721.10213 - Polyether polyester copolymer phosphate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... phosphate (generic). 721.10213 Section 721.10213 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10213 Polyether polyester copolymer phosphate (generic). (a) Chemical... as polyether polyester copolymer phosphate (PMN P-09-253) is subject to reporting under this...

  9. 21 CFR 582.5697 - Riboflavin-5-phosphate.

    Code of Federal Regulations, 2010 CFR

    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...

  10. 40 CFR 721.10046 - Polyaromatic amine phosphate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polyaromatic amine phosphate (generic... Specific Chemical Substances § 721.10046 Polyaromatic amine phosphate (generic). (a) Chemical substance and... amine phosphate (PMN P-02-747) is subject to reporting under this section for the significant new...

  11. 21 CFR 582.6215 - Monobasic calcium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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....

  12. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium phosphate, monobasic. 184.1141a Section... SAFE Listing of Specific Substances Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic (NH4H2PO4, CAS Reg. No. 7722-76-1) is manufactured by reacting ammonia...

  13. 40 CFR 721.3080 - Substituted phosphate ester (generic).

    Code of Federal Regulations, 2010 CFR

    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...

  14. Phosphate Ions - Does Exposure Lead to Degradation of Cementitious Materials?

    SciTech Connect

    Naus, Dan J; Mattus, Catherine H; Dole, Leslie Robert

    2008-01-01

    An assessment of the potential effects of phosphate ions on cementitious materials was made through a review of the literature, contacts with concrete research personnel, and conduct of a "bench-scale" laboratory investigation. Results indicate that no harmful interactions occur between phosphate ions and cememtitious materials unless phosphates are present in form of phosphoric acid.

  15. 40 CFR 721.643 - Ethoxylated alcohol, phosphated, amine salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ethoxylated alcohol, phosphated, amine... 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...

  16. 40 CFR 721.643 - Ethoxylated alcohol, phosphated, amine salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethoxylated alcohol, phosphated, amine... 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...

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

    PubMed

    Zubkov, Mikhail V; Martin, Adrian P; Hartmann, Manuela; Grob, Carolina; Scanlan, David 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 (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. PMID:26198420

  18. 21 CFR 182.1781 - Sodium aluminum phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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....

  19. 21 CFR 182.1781 - Sodium aluminum phosphate.

    Code of Federal Regulations, 2010 CFR

    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....

  20. 21 CFR 582.1781 - Sodium aluminum phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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...

  1. 21 CFR 582.1781 - Sodium aluminum phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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...

  2. 21 CFR 582.1781 - Sodium aluminum phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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 582.1781 - Sodium aluminum phosphate.

    Code of Federal Regulations, 2010 CFR

    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...

  4. 21 CFR 182.1781 - Sodium aluminum phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 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....

  5. 21 CFR 182.1781 - Sodium aluminum phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium aluminum phosphate. 182.1781 Section 182...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1781 Sodium aluminum phosphate. (a) Product. Sodium aluminum phosphate. (b) Conditions of use. This substance is...

  6. 21 CFR 582.1781 - Sodium aluminum phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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...

  7. 21 CFR 182.1781 - Sodium aluminum phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 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....

  8. 40 CFR 721.10332 - Lithium metal phosphate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Lithium metal phosphate (generic). 721... Substances § 721.10332 Lithium metal phosphate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as lithium metal phosphate (PMN...

  9. 40 CFR 721.10332 - Lithium metal phosphate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Lithium metal phosphate (generic). 721... Substances § 721.10332 Lithium metal phosphate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as lithium metal phosphate (PMN...

  10. 40 CFR 721.10332 - Lithium metal phosphate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Lithium metal phosphate (generic). 721... Substances § 721.10332 Lithium metal phosphate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as lithium metal phosphate (PMN...

  11. 1. NORTH IDAHO PHOSPHATE COMPANY PLANTS. VIEW IS TO THE ...

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

    1. NORTH IDAHO PHOSPHATE COMPANY PLANTS. VIEW IS TO THE NORTHEAST, WITH THE SHIPPING AND STORAGE WAREHOUSE, AMMONIUM PHOSPHATE FERTILIZER PLANT, AND PHOSPHORIC ACID PLANT APPEARING IN SUCCESSION DOWN GOVERNMENT GULCH. - North Idaho Phosphate Company, Silver King Community, Kellogg, Shoshone County, ID

  12. 46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220 Section... § 148.220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to the stowage and transportation of uniform, nonsegregating mixtures of nitrogen/phosphate or nitrogen/potash type fertilizers,...

  13. 46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220 Section... § 148.220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to the stowage and transportation of uniform, nonsegregating mixtures of nitrogen/phosphate or nitrogen/potash type fertilizers,...

  14. 46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220 Section... § 148.220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to the stowage and transportation of uniform, nonsegregating mixtures of nitrogen/phosphate or nitrogen/potash type fertilizers,...

  15. 46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220 Section... § 148.220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to the stowage and transportation of uniform, nonsegregating mixtures of nitrogen/phosphate or nitrogen/potash type fertilizers,...

  16. 40 CFR 721.10357 - Iron, citrate phosphate potassium complexes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Iron, citrate phosphate potassium... Specific Chemical Substances § 721.10357 Iron, citrate phosphate potassium complexes. (a) Chemical..., citrate phosphate potassium complexes (PMN P-09-382; CAS No. 120579-31-9) is subject to reporting...

  17. 40 CFR 721.10357 - Iron, citrate phosphate potassium complexes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Iron, citrate phosphate potassium... Specific Chemical Substances § 721.10357 Iron, citrate phosphate potassium complexes. (a) Chemical..., citrate phosphate potassium complexes (PMN P-09-382; CAS No. 120579-31-9) is subject to reporting...

  18. 40 CFR 721.10357 - Iron, citrate phosphate potassium complexes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Iron, citrate phosphate potassium... Specific Chemical Substances § 721.10357 Iron, citrate phosphate potassium complexes. (a) Chemical..., citrate phosphate potassium complexes (PMN P-09-382; CAS No. 120579-31-9) is subject to reporting...

  19. 21 CFR 182.6085 - Sodium acid phosphate.

    Code of Federal Regulations, 2010 CFR

    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...

  20. 21 CFR 582.6085 - Sodium acid phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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...

  1. 21 CFR 182.6085 - Sodium acid phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium acid phosphate. 182.6085 Section 182.6085...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 1 § 182.6085 Sodium acid phosphate. (a) Product. Sodium acid phosphate. (b) Conditions of use. This substance is generally recognized as safe when used...

  2. 21 CFR 582.6085 - Sodium acid phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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...

  3. 21 CFR 182.6085 - Sodium acid phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 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...

  4. 21 CFR 582.6085 - Sodium acid phosphate.

    Code of Federal Regulations, 2010 CFR

    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...

  5. 21 CFR 182.6085 - Sodium acid phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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...

  6. 21 CFR 582.6085 - Sodium acid phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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...

  7. 21 CFR 522.1883 - Prednisolone sodium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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...

  8. 21 CFR 522.1883 - Prednisolone sodium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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...

  9. ASPECTS OF PHOSPHATE UTILIZATION BY BLUE-GREEN ALGAE

    EPA Science Inventory

    The effects of various external phosphate concentrations on physiological and cytological aspects of Plectonema boryanum have been studied. P. boryanum was found to tolerate a wide range of phosphate concentrations, from 1 to 1000 mg of phosphate per liter. Growth of the alga in ...

  10. 21 CFR 520.2380f - Thiabendazole, piperazine phosphate powder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Thiabendazole, piperazine phosphate powder. 520....2380f Thiabendazole, piperazine phosphate powder. (a) Specifications. Each ounce of water dispersible powder contains 6.67 grams of thiabendazole and 8.33 grams of piperazine (as piperazine phosphate)....

  11. 21 CFR 520.2380f - Thiabendazole, piperazine phosphate powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Thiabendazole, piperazine phosphate powder. 520....2380f Thiabendazole, piperazine phosphate powder. (a) Specifications. Each ounce of water dispersible powder contains 6.67 grams of thiabendazole and 8.33 grams of piperazine (as piperazine phosphate)....

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

    PubMed Central

    Zubkov, Mikhail V.; Martin, Adrian P.; Hartmann, Manuela; Grob, Carolina; Scanlan, David 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 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. PMID:26198420

  13. 21 CFR 522.1883 - Prednisolone sodium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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...

  14. 21 CFR 522.1883 - Prednisolone sodium phosphate.

    Code of Federal Regulations, 2010 CFR

    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...

  15. 21 CFR 182.6085 - Sodium acid phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 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...

  16. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ammonium phosphate, monobasic. 184.1141a Section... SAFE Listing of Specific Substances Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic (NH4H2PO4, CAS Reg. No. 7722-76-1) is manufactured by reacting ammonia...

  17. 40 CFR 721.10317 - Alkyl phosphate derivative (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl phosphate derivative (generic... Specific Chemical Substances § 721.10317 Alkyl phosphate derivative (generic). (a) Chemical substance and... phosphate derivative (PMN P-02-1040) is subject to reporting under this section for the significant new...

  18. 21 CFR 520.1804 - Piperazine phosphate capsules.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Piperazine phosphate capsules. 520.1804 Section... phosphate capsules. (a) Specifications. Each capsule contains 120, 300, or 600 milligrams of piperazine phosphate monohydrate. (b) Sponsor. See No. 051311 in § 510.600(c) of this chapter. (c) Conditions of...

  19. 21 CFR 582.6215 - Monobasic calcium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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....

  20. 21 CFR 522.1244 - Levamisole phosphate injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Levamisole phosphate injection. 522.1244 Section... § 522.1244 Levamisole phosphate injection. (a) Specifications. Each milliliter of sterile aqueous solution contains levamisole phosphate equivalent to 136.5 or 182 milligrams of levamisole...

  1. 21 CFR 522.1244 - Levamisole phosphate injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Levamisole phosphate injection. 522.1244 Section... § 522.1244 Levamisole phosphate injection. (a) Specifications. Each milliliter of sterile aqueous solution contains levamisole phosphate equivalent to 136.5 or 182 milligrams of levamisole...

  2. 40 CFR 721.10213 - Polyether polyester copolymer phosphate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... phosphate (generic). 721.10213 Section 721.10213 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10213 Polyether polyester copolymer phosphate (generic). (a) Chemical... as polyether polyester copolymer phosphate (PMN P-09-253) is subject to reporting under this...

  3. 40 CFR 721.3080 - Substituted phosphate ester (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  4. 21 CFR 582.6085 - Sodium acid phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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...

  5. 21 CFR 582.6215 - Monobasic calcium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ammonium phosphate, monobasic. 184.1141a Section... SAFE Listing of Specific Substances Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic (NH4H2PO4, CAS Reg. No. 7722-76-1) is manufactured by reacting ammonia...

  7. 21 CFR 582.5697 - Riboflavin-5-phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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...

  8. 40 CFR 721.3080 - Substituted phosphate ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

  9. 40 CFR 721.10317 - Alkyl phosphate derivative (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl phosphate derivative (generic... Specific Chemical Substances § 721.10317 Alkyl phosphate derivative (generic). (a) Chemical substance and... phosphate derivative (PMN P-02-1040) is subject to reporting under this section for the significant new...

  10. 40 CFR 721.10046 - Polyaromatic amine phosphate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyaromatic amine phosphate (generic... Specific Chemical Substances § 721.10046 Polyaromatic amine phosphate (generic). (a) Chemical substance and... amine phosphate (PMN P-02-747) is subject to reporting under this section for the significant new...

  11. 21 CFR 582.5697 - Riboflavin-5-phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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...

  12. 21 CFR 182.6215 - Monobasic calcium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 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....

  13. 40 CFR 721.10317 - Alkyl phosphate derivative (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl phosphate derivative (generic... Specific Chemical Substances § 721.10317 Alkyl phosphate derivative (generic). (a) Chemical substance and... phosphate derivative (PMN P-02-1040) is subject to reporting under this section for the significant new...

  14. 40 CFR 721.10046 - Polyaromatic amine phosphate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Polyaromatic amine phosphate (generic... Specific Chemical Substances § 721.10046 Polyaromatic amine phosphate (generic). (a) Chemical substance and... amine phosphate (PMN P-02-747) is subject to reporting under this section for the significant new...

  15. 21 CFR 582.6215 - Monobasic calcium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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....

  16. 21 CFR 182.6215 - Monobasic calcium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Monobasic calcium phosphate. 182.6215 Section 182...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 1 § 182.6215 Monobasic calcium phosphate. (a) Product. Monobasic calcium phosphate. (b) Conditions of use. This substance is generally recognized as safe when...

  17. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ammonium phosphate, monobasic. 184.1141a Section 184.1141a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic...

  18. 21 CFR 582.5697 - Riboflavin-5-phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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...

  19. 40 CFR 721.10213 - Polyether polyester copolymer phosphate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... phosphate (generic). 721.10213 Section 721.10213 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10213 Polyether polyester copolymer phosphate (generic). (a) Chemical... as polyether polyester copolymer phosphate (PMN P-09-253) is subject to reporting under this...

  20. 40 CFR 721.10213 - Polyether polyester copolymer phosphate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... phosphate (generic). 721.10213 Section 721.10213 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10213 Polyether polyester copolymer phosphate (generic). (a) Chemical... as polyether polyester copolymer phosphate (PMN P-09-253) is subject to reporting under this...

  1. 40 CFR 721.3080 - Substituted phosphate ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  2. 21 CFR 520.1804 - Piperazine phosphate capsules.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Piperazine phosphate capsules. 520.1804 Section... phosphate capsules. (a) Specifications. Each capsule contains 120, 300, or 600 milligrams of piperazine phosphate monohydrate. (b) Sponsor. See No. 051311 in § 510.600(c) of this chapter. (c) Conditions of...

  3. 40 CFR 721.10046 - Polyaromatic amine phosphate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polyaromatic amine phosphate (generic... Specific Chemical Substances § 721.10046 Polyaromatic amine phosphate (generic). (a) Chemical substance and... amine phosphate (PMN P-02-747) is subject to reporting under this section for the significant new...

  4. 21 CFR 520.1804 - Piperazine phosphate capsules.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Piperazine phosphate capsules. 520.1804 Section... phosphate capsules. (a) Specifications. Each capsule contains 120, 300, or 600 milligrams of piperazine phosphate monohydrate. (b) Sponsor. See No. 051311 in § 510.600(c) of this chapter. (c) Conditions of...

  5. 21 CFR 182.6215 - Monobasic calcium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 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....

  6. 21 CFR 184.1141b - Ammonium phosphate, dibasic.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ammonium phosphate, dibasic. 184.1141b Section 184.1141b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... as GRAS § 184.1141b Ammonium phosphate, dibasic. (a) Ammonium phosphate, dibasic ((NH4)2HPO4, CAS...

  7. Three-dimensional open-framework Co II and Zn II phosphates synthesized via the amine phosphate route

    NASA Astrophysics Data System (ADS)

    Natarajan, Srinivasan; Neeraj, S.; Rao, C. N. R.

    1998-01-01

    The reaction of amine phosphates with metal ions, under mild conditions, has been utilized for the synthesis of open-framework phosphates. Two new amine phosphates, DABCO-phosphate and imidazole-phosphate, synthesized for the first time, were employed for this purpose. Thus, DABCO-phosphate reacts with Co(II) and Zn(II) ions giving rise to open-framework structures, of which [C 6N 2H 14][Co 2(HPO 4) 3], I, is a new 3-dimensional structure. Reaction of imidazole phosphate with Zn(II) ions gave a new phosphate, II, [C 3N 2H 6][Zn 4(OH)((PO 4) 3]. Both I and II have linkages involving MO 4 (M=Co, Zn) and PO 4 tetrahedra giving rise to three-dimensional structures. While I has two distinct channels along the crystallographic directions, II possesses only one-dimensional channels along with one-dimensional infinite ZnOZn chains.

  8. Microbial electrolysis cell accelerates phosphate remobilisation from iron phosphate contained in sewage sludge.

    PubMed

    Fischer, Fabian; Zufferey, Géraldine; Sugnaux, Marc; Happe, Manuel

    2015-01-01

    Phosphate was remobilised from iron phosphate contained in digested sewage sludge using a bio-electric cell. A significant acceleration above former results was caused by strongly basic catholytes. For these experiments a dual chambered microbial electrolysis cell with a small cathode (40 mL) and an 80 times larger anode (2.5 L) was equipped with a platinum sputtered reticulated vitreous carbon cathode. Various applied voltages (0.2-6.0 V) generated moderate to strongly basic catholytes using artificial waste water with pH close to neutral. Phosphate from iron phosphate contained in digested sewage sludge was remobilised most effectively at pH ∼13 with up to 95% yield. Beside minor electrochemical reduction, hydroxyl substitution was the dominating remobilisation mechanism. Particle-fluid kinetics using the "shrinking core" model allowed us to determine the reaction controlling step. Reaction rates changed with temperature (15-40 °C) and an activation energy of Ea = 55 kJ mol(-1) was found. These analyses indicated chemical and physical reaction control, which is of interest for future scale-up work. Phosphate remobilisation rates increased significantly, yields doubled and recovered PO4(3-) concentrations increased four times using a task specific bio-electric system. The result is a sustainable process for decentralized phosphate mining and a green chemical base generator useful also for many other sustainable processing needs. PMID:25407335

  9. Reducing the genetic redundancy of Arabidopsis PHOSPHATE TRANSPORTER1 transporters to study phosphate uptake and signaling.

    PubMed

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

    2015-04-01

    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

  10. Isothermal Damage and Fatigue Behavior of SCS-6/Timetal 21S [0/90](Sub S) Composite at 650 Deg C

    NASA Technical Reports Server (NTRS)

    Castelli, Michael G.

    1994-01-01

    The isothermal fatigue damage and life behaviors of SCS-6/Timetal 21S (0/90)s were investigated at 650 C. Strain ratcheting and degradation of the composite's static elastic modulus were carefully monitored as functions of cycles to indicate damage progression. Extensive fractographic and metallographic analyses were conducted to determine damage/failure mechanisms. Resulting fatigue lives show considerable reductions in comparison to (0) reinforced titanium matrix composites subjected to comparable conditions. Notable stiffness degradations were found to occur after the first cycle of loading, even at relatively low maximum stress levels, where cyclic lives are greater than 25,000 cycles. This was attributed to the extremely weak fiber/matrix bond which fails under relatively low transverse loads. Stiffness degradations incurred on first cycle loadings and degradations thereafter were found to increase with increasing maximum stress. Environmental effects associated with oxidation of the (90) fiber interfaces clearly played a role in the damage mechanisms as fracture surfaces revealed environment assisted matrix cracking along the (90) fibers. Metallographic analysis indicated that all observable matrix fatigue cracks initiated at the (90) fiber/matrix interfaces. Global de-bonding in the loading direction was found along the (90) fibers. No surface initiated cracks were evident and minimal if any (0) fiber cracking was visible.

  11. Multiple Gingival Recession Defects Treated with Coronally Advanced Flap and Either the VISTA Technique Enhanced with GEM 21S or Periosteal Pedicle Graft: A 9-Month Clinical Study.

    PubMed

    Dandu, Shruti Raju; Murthy, K Raja

    2016-01-01

    The objective of this study was to clinically evaluate and compare the efficacy of the vestibular incision subperiosteal tunnel access (VISTA) technique using Bio-Gide (Geistlich) membrane enhanced with GEM 21S (Osteohealth) with periosteal pedicle graft (PPG) using a coronally advanced flap. Multiple gingival recession sites in 15 individuals were randomly assigned either to experimental site A (VISTA) or experimental site B (PPG) in a split-mouth design. The clinical parameters were recorded at baseline and 9 months postoperatively. Repeated measures analysis of variance with post hoc Bonferroni correction and paired t test were used to assess statistical significance (P < .05). Mean recession depth significantly decreased from 4.21 ± 1.08 mm (presurgery) to 0.61 ± 0.92 mm (9 months) with VISTA (87.37 ± 17.78% root coverage) and from 4.17 ± 1.18 mm (presurgery) to 1.16 ± 0.92 mm (9 months) with PPG (71.84 ± 19.25% root coverage). Width of keratinized tissue and clinical attachment gain were significantly higher in the VISTA group compared with the PPG group. Within the limits of the study both VISTA and PPG groups resulted in a significant amount of root coverage. The VISTA technique was less invasive and required minimal time and clinical maneuvering. It also resulted in a superior esthetic outcome. PMID:26901301

  12. Proton/Phosphate Stoichiometry in Uptake of Inorganic Phosphate by Cultured Cells of Catharanthus roseus (L.) G. Don

    PubMed Central

    Sakano, Katsuhiro

    1990-01-01

    Upon absorption of phosphate, cultured cells of Catharanthus roseus (L.) G. Don caused a rapid alkalinization of the medium in which they were suspended. The alkalinization continued until the added phosphate was completely exhausted from the medium, at which time the pH of the medium started to drop sharply toward the original pH value. Phosphate exposure caused the pH of the medium to increase from pH 3.5 to values as high as 5.8, while the rate of phosphate uptake was constant throughout (10-17 micromoles per hour per gram fresh weight). This indicates that no apparent pH optimum exists for the phosphate uptake by the cultured cells. The amount of protons cotransported with phosphate was calculated from the observed pH change up to the maximum alkalinization and the titration curve of the cell suspension. Proton/phosphate transport stoichiometry ranged from less than unity to 4 according to the amount of phosphate applied. At low phosphate doses, the stoichiometries were close to 4, while at high phosphate doses, smaller stoichiometries were observed. This suggests that, at high phosphate doses, activation of the proton pump is induced by the longer lasting proton influx acidifying the cytoplasm. The increased H+ efflux due to the proton pump could partially compensate protons taken up via the proton-phosphate cotransport system. Thus, the H+/H2PO4− stoichiometry of the cotransport is most likely to be 4. PMID:16667491

  13. [Iron-based Phosphate Binders for ESRD Patients].

    PubMed

    Cozzolino, Mario; Mangano, Michela; Magagnoli, Lorenza; Di Lullo, Luca; Galassi, Andrea; Brancaccio, Diego; Bellasi, Antonio

    2016-01-01

    Several factors influence the choice of phosphate binder for patients, including older age, male gender, post-menopause, diabetes, low bone turnover, vascular/valvular calcification and inflammation. Unlike calcium-based phosphate binders, non-calcium-based phosphate binders, such as sevelamer and lanthanum carbonate, have been able to reduce the progression of bone disease to adynamic bone among patients with CKD. New iron-based phosphate binders are now available. With multiple options available for the reduction of phosphate, the focus has been on agents that do not contain calcium. This is because it is thought that calcium itself functions as a substrate for calcification. PMID:27545638

  14. [Identification and determination of phosphates in dairy products].

    PubMed

    Kirst, E

    1985-01-01

    This paper outlines the thin-layer chromatographic separation of condensed phosphates on polyamide-starch layers with subsequent digestion of the spots and photometric identification of the phosphates. With cheese and condensed milk the preparation of samples is carried out by isolation of the phosphate solution after protein precipitation by trichloroacetic acid. With pure phosphate solutions a recovery rate of 95.9% +/- 3.1% was established, whereas the recovery rate of added phosphate from processed cheese and condensed milk was 82.7% +/- 5.9%. PMID:4022105

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

    PubMed

    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. PMID:24288473

  16. Dual Mechanism of Ion Permeation through VDAC Revealed with Inorganic Phosphate Ions and Phosphate Metabolites

    PubMed Central

    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. PMID:25860993

  17. [Removal of Phosphate by Calcite in Open-System].

    PubMed

    Li, Zhen-xuan; Diao, Jia-yong; Huang, Li-dong; Chen, Yan-fan; Liu, Da-gang; Xu, Zheng-wen

    2015-12-01

    Batch methods were deployed to study the removal of phosphate by calcite in an open-system. Results showed that: (1) The pre-equilibrium process of calcite in open system could be achieved within 24 hours (2) The kinetic results showed that, at initial concentration of 0.5 mg · L⁻¹, the phosphate removal was almost completed within 10 hours of the first phase. The observation may be attributed to surface adsorption. At initial concentration of 2.5 mg · L⁻¹, the phosphate removal was mainly carried out by the precipitation of phosphate at later stage of the process; (3) At initial concentration of ≤ 2.5 mg · L⁻¹ setting 10 h as reaction time, the phosphate removal process was described well by the Langmuir model. It is hypothesized that surface adsorption was the principal removal way of phosphate; (4) With the addition of phthalate, at initial concentration of < 2.5 mg · L⁻¹, the phosphate removal rate experienced a small decrease. That was because phosphate was mainly removed by surface adsorption, and thus, phthalate was a competitor to phosphate for the same adsorption site. The phosphate removal rate increased a little at initial concentration of > 2.5 mg · L⁻¹, this was because the phosphate precipitation was reinforced by the increase of calcium concentration, which was caused by phthalate addition. PMID:27011989

  18. Relationship between Nitrite Reduction and Active Phosphate Uptake in the Phosphate-Accumulating Denitrifier Pseudomonas sp. Strain JR 12

    PubMed Central

    Barak, Yoram; van Rijn, Jaap

    2000-01-01

    Phosphate uptake by the phosphate-accumulating denitrifier Pseudomonas sp. JR12 was examined with different combinations of electron and carbon donors and electron acceptors. Phosphate uptake in acetate-supplemented cells took place with either oxygen or nitrate but did not take place when nitrite served as the final electron acceptor. Furthermore, nitrite reduction rates by this denitrifier were shown to be significantly reduced in the presence of phosphate. Phosphate uptake assays in the presence of the H+-ATPase inhibitor N,N′-dicyclohexylcarbodiimide (DCCD), in the presence of the uncoupler carbonyl cyanide 3-chlorophenylhydrazone (CCCP), or with osmotic shock-treated cells indicated that phosphate transport over the cytoplasmic membrane of this bacterium was mediated by primary and secondary transport systems. By examining the redox transitions of whole cells at 553 nm we found that phosphate addition caused a significant oxidation of a c-type cytochrome. Based on these findings, we propose that this c-type cytochrome serves as an intermediate in the electron transfer to both nitrite reductase and the site responsible for active phosphate transport. In previous studies with this bacterium we found that the oxidation state of this c-type cytochrome was significantly higher in acetate-supplemented, nitrite-respiring cells (incapable of phosphate uptake) than in phosphate-accumulating cells incubated with different combinations of electron donors and acceptors. Based on the latter finding and results obtained in the present study it is suggested that phosphate uptake in this bacterium is subjected to a redox control of the active phosphate transport site. By means of this mechanism an explanation is provided for the observed absence of phosphate uptake in the presence of nitrite and inhibition of nitrite reduction by phosphate in this organism. The implications of these findings regarding denitrifying, phosphate removal wastewater plants is discussed. PMID

  19. Characteristics of phosphate adsorption onto granulated coal ash in seawater.

    PubMed

    Asaoka, Satoshi; Yamamoto, Tamiji

    2010-08-01

    The deterioration of sediments is a serious environmental problem. Controlling nutrient release fluxes from sediments is important to alleviating eutrophication and to reducing terrigenous nutrient loads. The purpose of this study was to evaluate the phosphate removal performance of granulated coal ash (GCA) from seawater, which is produced from coal thermal electric power generation. Batch experiments were carried out to investigate the removal kinetics of phosphate from seawater under both oxic and anoxic conditions. Phosphate was removed well from seawater under both oxic and anoxic conditions. The adsorption isotherm for phosphate revealed that GCA could remove phosphate effectively from seawater above a concentration of 1.7micromolL(-1). GCA can reduce the concentration of phosphate in seawater effectively under anoxic conditions where iron type adsorbents cannot be applied. Therefore, GCA could potentially be used to adsorb phosphate in the organically-enriched sediment, which generally occurs under highly reductive conditions. PMID:20403625

  20. The pentose phosphate pathway and cancer

    PubMed Central

    Patra, Krushna C.; Hay, Nissim

    2015-01-01

    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. 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 pentose phosphate pathway. This review summarizes the fundamental functions of the PPP, its regulation in cancer cells, and its importance in cancer cell metabolism and survival. PMID:25037503

  1. Aluminum phosphate ceramics for waste storage

    DOEpatents

    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.

  2. Si complexes in calcium phosphate biomaterials.

    PubMed

    Gillespie, P; Wu, Gang; Sayer, M; Stott, M J

    2010-01-01

    Silicon complexes in silicon doped calcium phosphate bioceramics have been studied using (29)Si magic angle spinning nuclear magnetic resonance spectroscopy with the objective of identifying the charge compensation mechanisms of silicon dopants. Three different materials have been studied: a multiphase material composed pre-dominantly of a silicon stabilized alpha-tricalcium phosphate(alpha-TCP) phase plus a hydroxyapatite (HA) phase, a single phase Si-HA material and a single phase silicon stabilized alpha-TCP material. NMR results showed that in all three materials the silicon dopants formed Q(1) structures in which two silicate tetrahedra share an oxygen, creating an oxygen vacancy which compensated the substitution of two silicon for phosphorus. This finding may explain the phase evolution previously found where silicon stabilized alpha-TCP is found at low temperature after sintering. PMID:19714301

  3. Biomedical monitoring of phosphate removal by hemodialysis.

    PubMed

    Michalec, Michał; Fiedoruk-Pogrebniak, Marta; Matuszkiewicz-Rowińska, Joanna; Tymecki, Łukasz; Koncki, Robert

    2016-07-15

    A compact flow analysis system for non-invasive, dialysate-side monitoring of phosphate removal in the course of clinical hemodialysis treatment is presented. The monitor is based on solenoid operated micro-pumps and extremely cheap optoelectronic flow-through detector allowing photometric determination of phosphate in spent dialysate using a molybdenum blue method. The monitor can operate in both, discrete and continuous modes of measurement. The analytical utility of monitor has been tested with samples of spent dialysate produced by artificial kidney in the course of real hemodialysis sessions. The results of monitoring are comparable with those obtained using reference off-line method recommended for clinical analysis. Additionally, the possibility of two-side (dialysate and blood) monitoring of hemodialysis treatments with optoelectronic flow-through detectors has been announced. PMID:27136282

  4. Phosphate bonded solidification of radioactive incinerator wastes

    SciTech Connect

    Walker, B. W.; Langton, C. A.; Singh, D.

    1999-12-03

    The incinerator at the Department of Energy Savannah River Site burns low level radioactive and hazardous waste. Ash and scrubber system waste streams are generated during the incineration process. Phosphate Ceramic technology is being tested to verify the ash and scrubber waste streams can be stabilized using this solidification method. Acceptance criteria for the solid waste forms include leachability, bleed water, compression testing, and permeability. Other testing on the waste forms include x-ray diffraction and scanning electron microscopy.

  5. Phosphate Barriers for Immobilization of Uranium Plumes

    SciTech Connect

    Burns, Peter C.

    2005-06-01

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

  6. Phosphate Barriers for Immobilization of Uranium Plumes

    SciTech Connect

    Burns, Peter C.

    2005-06-01

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

  7. Method for phosphate-accelerated bioremediation

    DOEpatents

    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.

  8. Modifier coordination and phosphate glass networks

    SciTech Connect

    Brow, R.; Click, C.A.; Alam, T.M.

    1999-11-30

    The addition of up to approximately 16 mole% Cs{sub 2}O to vitreous P{sub 2}O{sub 5} reduces the glass transition temperature (T{sub g}) by 150 K, whereas further additions up to 50 mole% produce little additional change in T{sub g}. {sup 31}P magic angle spinning nuclear magnetic resonance spectra indicate that the phosphate network is progressively dipolymerized over the entire range of compositions. The property trend is explained by a transition in the Cs{sup +} coordination environment, from isolated Cs-polyhedra below {approximately}16 mole% Cs{sub 2}O to a corner-sharing Cs-polyhedral sub-structure in the glasses with greater Cs{sub 2}O contents. This modifier transition does not occur in Al-phosphate glasses. {sup 27}Al MAS NMR spectra indicate that the average Al coordination number decreases with increasing Al{sub 2}O{sub 3} content to avoid the formation of Al-O-Al bonds in these binary phosphate glasses.

  9. Phosphate adsorption on lanthanum loaded biochar.

    PubMed

    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. PMID:26871732

  10. Nano-porous calcium phosphate balls.

    PubMed

    Kovach, Ildyko; Kosmella, Sabine; Prietzel, Claudia; Bagdahn, Christian; Koetz, Joachim

    2015-08-01

    By dropping a NaH2PO4·H2O precursor solution to a CaCl2 solution at 90°C under continuous stirring in presence of two biopolymers, i.e. gelatin (G) and chitosan (C), supramolecular calcium phosphate (CP) card house structures are formed. Light microscopic investigations in combination with scanning electron microscopy show that the GC-based flower-like structure is constructed from very thin CP platelets. Titration experiments indicate that H-bonding between both biopolymers is responsible for the synergistic effect in presence of both polymers. Gelatin-chitosan-water complexes play an important role with regard to supramolecular ordering. FTIR spectra in combination with powder X-ray diffraction show that after burning off all organic components (heating up >600°C) dicalcium and tricalcium phosphate crystallites are formed. From high resolution transmission electron microscopy (HR-TEM) it is obvious to conclude, that individual crystal platelets are dicalcium phosphates, which build up ball-like supramolecular structures. The results reveal that the GC guided crystal growth leads to nano-porous supramolecular structures, potentially attractive candidates for bone repair. PMID:26052107

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

    PubMed

    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. PMID:27460160

  12. Biostimulation by Glycerol Phosphate to Precipitate Recalcitrant Uranium(IV) Phosphate.

    PubMed

    Newsome, Laura; Morris, Katherine; Trivedi, Divyesh; Bewsher, Alastair; Lloyd, Jonathan R

    2015-09-15

    Stimulating the microbial reduction of aqueous uranium(VI) to insoluble U(IV) via electron donor addition has been proposed as a strategy to remediate uranium-contaminated groundwater in situ. However, concerns have been raised regarding the longevity of microbially precipitated U(IV) in the subsurface, particularly given that it may become remobilized if the conditions change to become oxidizing. An alternative mechanism is to stimulate the precipitation of poorly soluble uranium phosphates via the addition of an organophosphate and promote the development of reducing conditions. Here, we selected a sediment sample from a U.K. nuclear site and stimulated the microbial community with glycerol phosphate under anaerobic conditions to assess whether uranium phosphate precipitation was a viable bioremediation strategy. Results showed that U(VI) was rapidly removed from solution and precipitated as a reduced crystalline U(IV) phosphate mineral similar to ningyoite. This mineral was considerably more recalcitrant to oxidative remobilization than the products of microbial U(VI) reduction. Bacteria closely related to Pelosinus species may have played a key role in uranium removal in these experiments. This work has implications for the stewardship of uranium-contaminated groundwater, with the formation of U(IV) phosphates potentially offering a more effective strategy for maintaining low concentrations of uranium in groundwater over long time periods. PMID:26292021

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

    PubMed

    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. PMID:24090874

  14. Characterization of calcium phosphate cements modified by addition of amorphous calcium phosphate.

    PubMed

    Van den Vreken, Natasja M F; Pieters, Ilse Y; Declercq, Heidi A; Cornelissen, Maria J; Verbeeck, Ronald M H

    2010-02-01

    In this study the influence of amorphous calcium phosphate (ACP) on the setting of, and the formed apatite crystallite size in, a calcium phosphate cement (CPC) based on alpha-tricalcium phosphate (alpha-TCP) or tetracalcium phosphate (TTCP)/monocalcium phosphate monohydrate (MCPM) was investigated. Setting times at 22 degrees C were measured in air atmosphere; those at 37 degrees C were measured at 100% relative humidity. The phase composition of the set cements was investigated after 1 week using X-ray diffractometry and infrared spectroscopy and the morphology was investigated using scanning electron microscopy. The compressive strength (CS) of the set CPCs was measured after 1 day. Viability of MC3T3-E1 cells on the CPCs was analyzed after 7, 14 and 21 days of incubation using the CellTiter 96 Aqueous Non-Radioactive Cell Proliferation Assay. The alpha-TCP-based cement exhibited long setting times, a high CS and was converted to a calcium-deficient hydroxyapatite (CDHAp). The TTCP/MCPM-based CPC was only partly converted to CDHAp, produced acceptable setting times and had a low CS. Addition of ACP to these two CPCs resulted in cements that exhibited good setting times, CS suitable for non-load-bearing applications and a full conversion to nanocrystalline CDHAp. Moreover, the ACP containing CPCs demonstrated good cell viability, making them suitable candidates for bone substitute materials. PMID:19654057

  15. Double-blind comparison of the respiratory and sedative effects of codeine phosphate and (+/-)-glaucine phosphate in human volunteers.

    PubMed Central

    Redpath, J B; Pleuvry, B J

    1982-01-01

    1 Two antitussive agents (+/-)-glaucine phosphate and codeine phosphate have been compared with placebo with respect to ventilation, ventilatory response to carbon dioxide, pulse, blood pressure, digit symbol substitution, sedation score and the Zahlen-Verbindung test performance in ten healthy volunteers (22-36 years). The study was double-blind and the two doses of each antitussive agent and the placebo were administered as a syrup. 2 Both codeine phosphate and (+/-)-glaucine phosphate displaced the ventilatory response to carbon dioxide to the right. 3 The effect of codeine phosphate on the ventilatory response to carbon dioxide was not dose dependent: 30 mg produced greater effects than the 60 mg dose. 4 Only the highest dose of (+/-)-glaucine phosphate (60 mg) caused respiratory depression and this was associated with sedation and decreased performance in the digit symbol substitution test. 5 Neither antitussive agent had significant effects upon pulse or blood pressure and codeine phosphate had no detectable sedative activity. PMID:6814470

  16. A safer disposal of hazardous phosphate coating sludge by formation of an amorphous calcium phosphate matrix.

    PubMed

    Navarro-Blasco, I; Duran, A; Pérez-Nicolás, M; Fernández, J M; Sirera, R; Alvarez, J I

    2015-08-15

    Phosphate coating hazardous wastes originated from the automotive industry were efficiently encapsulated by an acid-base reaction between phosphates present in the sludge and calcium aluminate cement, yielding very inert and stable monolithic blocks of amorphous calcium phosphate (ACP). Two different compositions of industrial sludge were characterized and loaded in ratios ranging from 10 to 50 wt.%. Setting times and compressive strengths were recorded to establish the feasibility of this method to achieve a good handling and a safe landfilling of these samples. Short solidification periods were found and leaching tests showed an excellent retention for toxic metals (Zn, Ni, Cu, Cr and Mn) and for organic matter. Retentions over 99.9% for Zn and Mn were observed even for loadings as high as 50 wt.% of the wastes. The formation of ACP phase of low porosity and high stability accounted for the effective immobilization of the hazardous components of the wastes. PMID:26024992

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

    PubMed

    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. PMID:21190789

  18. Research and engineering assessment of biological solubilization of phosphate

    SciTech Connect

    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.

  19. Magnetic alginate-layered double hydroxide composites for phosphate removal.

    PubMed

    Lee, Chang-Gu; Kim, Song-Bae

    2013-01-01

    The objective of this study was to investigate phosphate removal using magnetic alginate-layered double hydroxide (LDH) composites. The magnetic composites were prepared by entrapping synthetic magnetic iron oxide and calcined Mg-Al LDH in polymer matrix (alginate). Results showed that the magnetic composites (2% magnetic iron oxide and 6% calcined Mg-Al LDH) were effective in the removal of phosphate with the sorption capacity of 5.0 +/- 0.1 mgP/g under given experimental conditions (adsorbent dose = 0.05 g in 30 ml solution; initial phosphate concentration = 10 mgP/l; reaction time = 24 h). Both magnetic iron oxide and calcined Mg-Al LDH have the ability to adsorb phosphate, with the latter having much higher sorption capacity. In the magnetic composites, calcined Mg-Al LDH functions as a phosphate adsorbent while magnetic iron oxide provides both magnetic and sorption properties. Results also demonstrated that phosphate sorption to the magnetic composites reached equilibrium at 24 h. The maximum phosphate sorption capacity was determined to be 39.1 mgP/g. In addition, phosphate removal was not sensitive to initial solution pH between 4.1 and 10.2. Only 9% of the phosphate sorption capacity was reduced as the solution pH increased from 4.1 to 10.2. This study demonstrated that magnetic alginate-LDH composites could be used for phosphate removal in combination with magnetic separation. PMID:24527638

  20. Phosphate sources and their suitability for remediation of contaminated soils.

    PubMed

    Knox, A S; Kaplan, D I; Paller, M H

    2006-03-15

    Phosphate minerals and specifically apatite show promise for environmental cleanup because they can form stable compounds with a wide range of cationic contaminants. However, phosphate minerals naturally accumulate some heavy metals that may cause additional contamination of the environment if used improperly. Nine commercially available phosphate materials were evaluated for remediation of contaminated soil based on solubility, concentration of metal/metalloid impurities, and leachability of impurity metal/metalloids. The phosphate materials consisted of three groups: processed (i.e., fertilizers), mined (rock phosphates from different formations), and biogenic (ground fish bone). Processed and mined rock phosphates contained relatively high total concentrations of As, Co, Cr, and Cu but did not exceed the RCRA toxicity characteristic leaching procedure (TCLP) limits. Biogenic apatite contained much lower metal concentrations than processed and mined rock phosphate and was appreciably more soluble. By combining biogenic and mined phosphate it is possible to obtain a wide range of phosphate release rates, permitting rapid immobilization of contaminants while providing a slow release of phosphate for continued long-term treatment. PMID:16150478

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

    PubMed

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

    2009-07-01

    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 < pH < 10). The L1 receptor system shows selectivity toward PPi over Pi, and on the contrary the L2 system exhibits opposite selectivity. This different selectivity is ascribed to the different Zn(II)-Zn(II) distances between the two metal centers which, showing a similar coordination requirement and binding 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. PMID:19432470

  2. Using oxygen isotopes of phosphate to investigate phosphate release from sediments and phosphate input from waste water treatment plants into Lake Erie

    NASA Astrophysics Data System (ADS)

    Roberts, K.; Klass, T.; Watson, S.; Mah, B.; Paytan, A.

    2010-12-01

    Phosphorus is often a limiting nutrient in freshwater systems; however increased inputs have been promoting eutrophication in many of these systems. Phosphate is one of the more bio-available forms of phosphate and it has been suggested by Elsbury et al., (2009) that in addition to riverin input some other yet unidentified phosphate source contributes to the phosphorous loading in Lake Erie. We are using the oxygen isotope of phosphate to identify two potential sources of phosphorus into Lake Erie. Specifically we determine the isotopic composition of oxygen in phosphate which is associated with various sedimentary phases at two sites in Lake Erie. The distinct sedimentary phases have different phosphate mobility and thus release potential to the lake. In addition we determine the isotopic signature of phosphate that is released into the lake from treated waste water effluent throughout the year. Results will be compared to the isotopic signature of phosphate in Lake water to evaluate the potential contribution form each of these sources.

  3. The aluminum phosphate zone in the Peace River area, land-pebble phosphate field, Florida

    USGS Publications Warehouse

    Cathcart, James B.

    1953-01-01

    The Peace River area, comprising T. 30 and 31 S., R. 24 and 25 E., contains a thicker and more persistent aluminum phosphate zone, and one that is higher in P2O5 and uranium content than is known elsewhere in the land-pebble phosphate district. This report has been prepared to bring together all of the information on the aluminum phosphate zone in the area where the first plant to treat this material will probably be located. The area may be divided into three physiographic units, (1) the ridge, (2) the flatwoods, and (3) the valley. Maps showing distribution and grade of the aluminum phosphate zone indicate that the zone is thin or absent in the ridge unit, thickest and most persistent, and of the best grade in P2O5 and uranium in the flatwoods unit, and absent or very low in grade in the valley unit. Maps of thickness and of chemical composition show that even in favorable areas there are places where the aluminum phosphate zone is missing or of questionable economic importance. The distribution maps also show that areas of high P2O5 and high uranium content coincide closely. Areas containing thick aluminum phosphate material usually have high uranium and P2O5 contents. It is estimated that an average of 13,000 tons per day of aluminum phosphate material might be mined from this area. This figure is based on the probable amount of time, per year, that mining would be in favorable ground. When all mines in the area are in favorable ground, the tonnage per day might be about 23,000 tons. Tonnages of aluminum phosphate material have been computed for about 36 percent of the area of T. 30 S., R. 25 E., and for 18 percent of the area of T. 31 S., R. 25 E. The total inferred tonnage is about 150,000,000 short tons, with an average grade of 0.012 percent U3O8.

  4. Integrated assessment of the phosphate industry. [Radiological impact of uranium extraction

    SciTech Connect

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

    1980-05-01

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

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

    PubMed

    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. PMID:27612721

  6. Synthesis and characterization of different nanostructures of cobalt phosphate

    SciTech Connect

    Badsar, M.; Edrissi, M.

    2010-09-15

    In this research, different nanostructures of cobalt phosphate were successfully prepared. Flowerlike cobalt phosphate and platelike ammonium cobalt phosphate were made by coprecipitation method without any use of surfactant or capping agent as structure directors. Reverse micelle route in water/CTAB/n-hexanol microemulsion system was used to synthesize cobalt phosphate nanoparticles. The synthesized nanostructures were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), chemical analysis, and BET. The SEM images showed that the flowerlike nanostructure is an arrangement of cobalt phosphate plates. TEM images revealed that the nanoparticles are spherical with the diameter of 30-50 nm. The purity of cobalt phosphate nanoparticles was confirmed by chemical analysis. Finally, the possible mechanisms which can describe the formation of these nanostructures were discussed.

  7. Plant tissue hybrid electrode for determination of phosphate and fluoride

    SciTech Connect

    Schubert, F.; Renneberg, R.; Scheller, F.W.; Kirstein, L.

    1984-08-01

    A biosensor for inorganic phosphate and fluoride has been developed by coupling a potato (Solanum tuberosum) tissue slice and immobilized glucose oxidase with a Clark oxygen electrode. Measurement is based on the inhibition by either ion of potato acid phosphates catalyzed glucose 6-phosphate hydrolysis. The precision is 1.7% and 6.5% and the lower detection limit 2.5 X 10/sup -5/ M and 1 X 10/sup -4/ M for phosphate and fluoride, respectively. For phosphate determination the hybrid sensor is stable for 28 days or 300 assays. With a higher limit of detection the sensor can be applied in a commercial enzyme electrode based device. Its application for phosphate determination in fertilizer and urine samples is described.

  8. Carbon Mineralization Using Phosphate and Silicate Ions

    NASA Astrophysics Data System (ADS)

    Gokturk, H.

    2013-12-01

    Carbon dioxide (CO2) reduction from combustion of fossil fuels has become an urgent concern for the society due to marked increase in weather related natural disasters and other negative consequences of global warming. CO2 is a highly stable molecule which does not readily interact with other neutral molecules. However it is more responsive to ions due to charge versus quadrupole interaction [1-2]. Ions can be created by dissolving a salt in water and then aerosolizing the solution. This approach gives CO2 molecules a chance to interact with the hydrated salt ions over the large surface area of the aerosol. Ion containing aerosols exist in nature, an example being sea spray particles generated by breaking waves. Such particles contain singly and doubly charged salt ions including Na+, Cl-, Mg++ and SO4--. Depending on the proximity of CO2 to the ion, interaction energy can be significantly higher than the thermal energy of the aerosol. For example, an interaction energy of 0.6 eV is obtained with the sulfate (SO4--) ion when CO2 is the nearest neighbor [2]. In this research interaction between CO2 and ions which carry higher charges are investigated. The molecules selected for the study are triply charged phosphate (PO4---) ions and quadruply charged silicate (SiO4----) ions. Examples of salts which contain such molecules are potassium phosphate (K3PO4) and sodium orthosilicate (Na4SiO4). The research has been carried out with first principle quantum mechanical calculations using the Density Functional Theory method with B3LYP functional and Pople type basis sets augmented with polarization and diffuse functions. Atomic models consist of the selected ions surrounded by water and CO2 molecules. Similar to the results obtained with singly and doubly charged ions [1-2], phosphate and silicate ions attract CO2 molecules. Energy of interaction between the ion and CO2 is 1.6 eV for the phosphate ion and 3.3 eV for the silicate ion. Hence one can expect that the selected

  9. PROCESS FOR THE RECOVERY OF URANIUM FROM PHOSPHATIC ORE

    DOEpatents

    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.

  10. Novel lead-iron phosphate glass

    DOEpatents

    Boatner, Lynn A.; Sales, Brian C.

    1989-01-01

    The invention described and claimed in the specification relates to the discovery that effective addition of Fe.sub.2 O.sub.3 to a lead phosphate glass results in a glass having enhanced chemical durability and physical stability, and consists essentially of the glass resulting from melting a mixture consisting essentially of, in weight percent, 40-66 percent PbO, 30-55 percent P.sub.2 O.sub.5 and an effective concentration up to 12 percent Fe.sub.2 O.sub.3.

  11. Novel lead-iron phosphate glass

    DOEpatents

    Boatner, L.A.; Sales, B.C.

    1989-07-11

    The invention described and claimed in the specification relates to the discovery that effective addition of Fe[sub 2]O[sub 3] to a lead phosphate glass results in a glass having enhanced chemical durability and physical stability, and consists essentially of the glass resulting from melting a mixture consisting essentially of, in weight percent, 40--66 percent PbO, 30--55 percent P[sub 2]O[sub 5] and an effective concentration up to 12 percent Fe[sub 2]O[sub 3].

  12. Intercalation of cyclic ketones into vanadyl phosphate

    SciTech Connect

    Zima, Vitezslav . E-mail: vitezslav.zima@upce.cz; Melanova, Klara; Benes, Ludvik; Trchova, Miroslava; Dybal, Jiri

    2005-01-15

    Intercalation compounds of vanadyl phosphate with cyclic ketones (cyclopentanone, cyclohexanone, 4-methylcyclohexanone, and 1,4-cyclohexanedione) were prepared from corresponding propanol or ethanol intercalates by a molecular exchange. The intercalates prepared were characterized using powder X-ray diffraction and thermogravimetric analysis. The intercalates are stable in dry environment and decompose slowly in humid air. Infrared and Raman spectra indicate that carbonyl oxygens of the guest molecules are coordinated to the vanadium atoms of the host layers. The local structure and interactions in the cyclopentanone intercalate have been suggested on the basis of quantum chemical calculations.

  13. Glycerophosphodiester phosphodiesterases play an important role in phosphate recycling and phosphate sensing in white lupin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    White lupin (Lupinus albus L.), a well adapted species to phosphate (Pi) impoverished soils, develops short, densely clustered lateral roots (cluster/proteoid roots) to increase Pi uptake. Here, we report two white lupin glycerophosphodiester phosphodiesterase (GPX-PDE) genes which share strong homo...

  14. Interactions between organic amendments and phosphate fertilizers modify phosphate sorption processes in an acid soil

    SciTech Connect

    Sckefe, C.R.; Patti, A.F.; Clune, T.S.; Jackson, W.R.

    2008-07-15

    To determine how organic amendments and phosphate fertilizers interact to modify P sorption processes, three phosphate fertilizers were applied to lignite- and compost-amended acid soil and incubated for either 3 or 26 days. The fertilizers applied were potassium dihydrogen phosphate, triple superphosphate, and diammonium phosphate (DAP). After 3 days of incubation, sorption of all three P sources was decreased in the lignite-amended treatments, whereas P sorption was increased in the compost-amended treatments. Increased incubation time (26 days) resulted in significantly decreased P sorption when DAP was added to lignite-amended treatments. Addition of triple superphosphate increased P sorption in lignite- and compost-amended treatments and decreased solution pH compared with DAP application. In addition to the effect of P source, differences in P sorption between the lignite- and compost-amended treatments were driven by differences in solution chemistry, predominantly solution pH and cation dynamics. Soil amendment and fertilizer addition also increased microbial activity in the incubation systems, as measured by carbon dioxide respiration. It is proposed that the combination of lignite and DAP may contribute to decreased P sorption in acid soils, with the positive effects likely caused by both chemical and biological processes, including the formation of soluble organic-metal complexes.

  15. Physiology of Calcium and Phosphate Metabolism: 1980 Refresher Course, Syllabus.

    ERIC Educational Resources Information Center

    Knox, Franklyn G., Ed.

    1980-01-01

    This syllabus reviews information concerning calcium and phosphate regulation. Topics of interest include the following: calcium metabolism, phosphorus metabolism, bone, parathyroid hormone, calcitonin, and vitamin D. (CS)

  16. Phosphatic fertiliser poisoning of sheep: experimental studies.

    PubMed

    O'Hara, P J; McCausland, I P; Coup, M R

    1982-11-01

    The toxicity of serpentine phosphate and superphosphate for non-pregnant dry ewes, pregnant ewes and lactating ewes was investigated by oral dosing. An attempt was made to reproduce a natural episode of poisoning by exposing pregnant and lactating ewes to topdressed pasture. A total dose in the range of 1200 to 1800 g of serpentine phosphate was required to kill two ewes and it was concluded that natural episodes of poisoning with this material are unlikely. The toxic process was similar to that caused by superphosphate. The LD50 of superphosphate was estimated to be in the range of 5 to 6 g/kg and a dose in the range of 200 to 300 g was sufficient to kill most sheep. The apparently greater susceptibility of pregnant and lactating sheep to poisoning suggested by the study of natural outbreaks was not demonstrated in these experiments, but the numbers of experimental animals may have been too small to detect differing susceptibility. The clinical disease resembled that seen in natural episodes; anorexia, diarrhoea, progressive depression and death in a period of 5 to 8 days after the start of dosing. Sublethal doses produced a transient diarrhoea and, in two sheep, a severe wool-break. The principal biochemical changes were hyperphosphataemia and evidence of renal failure (oliguria, uraemia, azotaemia). Gross lesions were not consistently present but included abomasal ulceration and renal cortical swelling and pallor. The histopathological evidence of renal tubular obstruction by flocculant eosinophilic casts was characteristic. PMID:16030836

  17. Leishmanial phosphatase hydrolyzes phosphoproteins and inositol phosphates

    SciTech Connect

    Saha, A.K.; Das, S.; Glew, R.H.

    1986-05-01

    An extensively purified preparation of the predominant, tartrate-resistant acid phosphatase (ACP) from the external surface of Leishmania donovani promastigotes form catalyzes the dephosphorylation of several phosphoproteins; these include: pyruvate kinase, phosphorylase kinase and histones. However, the protein phosphatase activity of ACP is very low compared with that of other protein phosphates known to be involved in regulating various metabolic pathways. /sup 32/P-labelled inositoltriphosphate (IP3), a well-established second messenger derived from phosphatidylinositol-4,5-diphosphate (PIP2), was a substrate for the leishmanial acid phosphatase; incubation of the IP3 preparation with 13.2 milliunits (1 unit equals 1 ..mu..mol 4-methylumbelliferyl phosphate (MUP) cleaved per min at pH 5.5) of ACP at pH 5.5 for 4 hr resulted in hydrolysis of 75% of the radiolabelled substrate resulting in a mixture of inositoldiphosphate and inositolmonophosphate. In addition PIP2 was hydrolyzed rapidly by ACP at pH 5.5 (V/sub max/, 71 units/mg protein; k/sub m/, 4.16 ..mu..M). In contrast, to MUP which is hydrolzyed most rapidly at pH 5.5, PIP2 hydrolysis was optimal at pH 6.8. These observations raise the possibility that ACP could play a role in the host-phagocyte interaction by degrading the precursor of the second messenger, PIP2 or the second messenger itself, IP3.

  18. Elemental analysis of Egyptian phosphate fertilizer components.

    PubMed

    El-Bahi, S M; El-Dine, N Walley; El-Shershaby, A; Sroor, A

    2004-03-01

    The accumulation of certain elements in vitally important media such as water, soil, and food is undesirable from the medical point of view. It is clear that the fertilizers vary widely in their heavy metals and uranium content. A shielded high purity germanium HPGe detector has been used to measure the natural concentration of 238U, 232Th, and 40K activities in the phosphate fertilizer and its components collected from Abu-Zaabal fertilizers and chemical industries in Egypt. The concentration ranges were 134.97-681.11 Bq kg(-1), 125.23-239.26 Bq kg(-1), and 446.11-882.45 Bq kg(-1) for 238U, 232Th, and 40K, respectively. The absorbed dose rate and external hazard index were found to be from 177.14 to 445.90 nGy h(-1) and 1.03 to 2.71 nGy y(-1), respectively. The concentrations of 22 elements (Be, Na, Mg, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Zr, Mo, Cd, Ba) in the samples under investigation were determined by inductively coupled plasma optical-emission spectrometry (ICP-OES). The results for the input raw materials (rock phosphate, limestone and sulfur) and the output product as final fertilizer are presented and discussed. PMID:14982231

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

    PubMed Central

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

    2014-01-01

    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 13C-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

  20. Silica-Supported Oligomeric Benzyl Phosphate (Si-OBP) and Triazole Phosphate (Si-OTP) Alkylating Reagents.

    PubMed

    Maity, Pradip K; Faisal, Saqib; Rolfe, Alan; Stoianova, Diana; Hanson, Paul R

    2015-10-16

    The syntheses of silica-supported oligomeric benzyl phosphates (Si-OBP(n)) and triazole phosphates (Si-OTP(n)) using ring-opening metathesis polymerization (ROMP) for use as efficient alkylating reagents is reported. Ease of synthesis and grafting onto the surface of norbornenyl-tagged (Nb-tagged) silica particles has been demonstrated for benzyl phosphate and triazole phosphate monomers. It is shown that these silica polymer hybrid reagents, Si-OBP(n) and Si-OTP(n), can be used to carry out alkylation reactions with an array of different nucleophiles to afford the corresponding benzylated and (triazolyl)methylated products in good yield and high purity. PMID:26430955

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

    PubMed

    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

  2. Stromal phosphate concentration is low during feedback limited photosynthesis

    SciTech Connect

    Sharkey, T.D.; Vanderveer, P.J. )

    1989-10-01

    It has been hypothesized that photosynthesis can be feedback limited when the phosphate concentration cannot be both low enough to allow starch and sucrose synthesis at the required rate and high enough for ATP synthesis at the required rate. We have measured the concentration of phosphate in the stroma and cytosol of leaves held under feedback conditions. We used nonaqueous fractionation techniques with freeze-clamped leaves of Phaseolus vulgaris plants grown on reduced phosphate nutrition. Feedback was induced by holding leaves in low O{sub 2} or high CO{sub 2} partial pressure. We found 7 millimolar phosphate in the stroma of leaves in normal oxygen but just 2.7 millimolar phosphate in leaves held in low oxygen. Because 1 to 2 millimolar phosphate in the stroma may be metabolically inactive, we estimate that in low oxygen, the metabolically active pool of phosphate is between negligible and 1.7 millimolar. We conclude that halfway between these extremes, 0.85 millimolar is a good estimate of the phosphate concentration in the stroma of feedback-limited leaves and that the true concentration could be even lower. The stromal phosphate concentration was also low when leaves were held in high CO{sub 2}, which also induces feedback-limited photosynthesis, indicating that the effect is related to feedback limitation, not to low oxygen per se. We conclude that the concentration of phosphate in the stroma is usually in excess and that it is sequestered to regulate photosynthesis, especially starch synthesis. The capacity for this regulation is limited by the coupling factor requirement for phosphate.

  3. Injectable and rapid-setting calcium phosphate bone cement with dicalcium phosphate dihydrate.

    PubMed

    Burguera, Elena F; Xu, Hockin H K; Weir, Michael D

    2006-04-01

    Calcium phosphate cement (CPC) sets in situ with intimate adaptation to the contours of defect surfaces, and forms an implant having a structure and composition similar to hydroxyapatite, the putative mineral in teeth and bones. The objective of the present study was to develop an injectable CPC using dicalcium phosphate dihydrate (DCPD) with a high solubility for rapid setting. Two agents were incorporated to impart injectability and fast-hardening to the cement: a hardening accelerator (sodium phosphate) and a gelling agent (hydroxypropyl methylcellulose, HPMC). The cement with DCPD was designated as CPC(D), and the conventional cement was referred to as CPC(A). Using water without sodium phosphate, CPC(A) had a setting time of 82 +/- 6 min. In contrast, CPC(D) exhibited rapid setting with a time of 17 +/- 1 min. At 0.2 mol/L sodium phosphate, setting time for CPC(D) was 15 +/- 1 min, significantly faster than 40 +/- 2 min for CPC(A) (Tukey's at 0.95). Sodium phosphate decreased the paste injectability (measured as the paste mass extruded from the syringe divided by the original paste mass inside the syringe). However, the addition of HPMC dramatically increased the paste injectability. For CPC(D), the injectability was increased from 65% +/- 12% without HPMC to 98% +/- 1% with 1% HPMC. Injectability of CPC(A) was also doubled to 99% +/- 1%. The injectable and rapid-setting CPC(D) possessed flexural strength and elastic modulus values overlapping the reported values for sintered porous hydroxyapatite implants and cancellous bone. In summary, the rapid setting and relatively high strength and elastic modulus of CPC(D) should help the graft to quickly attain strength and geometrical integrity within a short period of time postoperatively. Furthermore, the injectability of CPC(D) may have potential for procedures involving defects with limited accessibility or narrow cavities, when there is a need for precise placement of the paste, and when using minimally invasive

  4. Effects of inorganic phosphate on endothermic force generation in muscle.

    PubMed

    Ranatunga, K W

    1999-07-01

    Using a rapid (ca. 0.2 ms) laser temperature jump technique, the rate of endothermic force generation was examined in single-skinned (rabbit psoas) muscle fibres when they were exposed to different levels of inorganic phosphate (a product released during ATP hydrolysis in active muscle). The steady force is reduced by increased phosphate but the apparent rate constant of force generation induced by a standard temperature jump (from ca. 9 degrees C to ca. 12 degrees C) increases two- to threefold when the phosphate added is increased from zero to ca. 25 mM. The increase in the apparent rate constant also exhibits saturation at higher phosphate levels and the relation is hyperbolic. Detailed examination of the data, particularly in relation to our pressure release experiments, leads to a scheme for the molecular steps involved in phosphate release and force generation in active muscle fibres, where phosphate release from attached cross-bridges involves three reversible and sequentially faster molecular steps. Step one is a moderately slow, pre-force generation step that probably represents a transition of cross-bridges from non-specific to stereospecific attached states. Step two is moderately fast and represents endothermic cross-bridge force generation (temperature sensitive) and step three is a very rapid phosphate release. Such a scheme accommodates findings from a variety of different studies, including pressure perturbation experiments and other studies where the effect of phosphate on muscle force was studied. PMID:10445293

  5. Phosphate Toxicity in CKD: The Killer among Us.

    PubMed

    Ritter, Cynthia S; Slatopolsky, Eduardo

    2016-06-01

    Maintenance of a normal serum phosphate level depends on absorption in the gut, reabsorption and excretion by the kidney, and the flux between the extracellular and skeletal pools. Phosphate homeostasis is a coordinated, complex system of crosstalk between the bone, intestine, kidney, and parathyroid gland. Dysfunction of this system has serious clinical consequences in healthy individuals and those with conditions, such as CKD, in which hyperphosphatemia is associated with increased risks of cardiovascular morbidity and mortality. The last half-century of renal research has helped define the contribution of the parathyroid hormone, calcitriol, fibroblast growth factor 23, and Klotho in the regulation of phosphate. However, despite new discoveries and insights gained during this time, what remains unchanged is the recognition that phosphate retention is the initiating factor for the development of many of the complications observed in CKD, namely secondary hyperparathyroidism and bone and cardiovascular diseases. Controlling phosphate load remains the primary goal in the treatment of CKD. This review discusses the clinical effects of dysregulated phosphate metabolism, particularly in CKD, and its association with cardiovascular disease. The importance of early control of phosphate load in the treatment of CKD is emphasized, and the latest research in the treatment of phosphate retention is discussed. PMID:26912542

  6. 2. PHOSPHATE UNLOADING BUILDING. VIEW IS TO THE NORTH. THIS ...

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

    2. PHOSPHATE UNLOADING BUILDING. VIEW IS TO THE NORTH. THIS STRUCTURE WAS RELOCATED TO THE SOUTH OF ITS ORIGINAL SITE IN 1993 FOR USE AS A DECONTAMINATION FACILITY WITHIN THE BUNKER HILL SUPERFUND SITE. - North Idaho Phosphate Company, Silver King Community, Kellogg, Shoshone County, ID

  7. 40 CFR 721.6005 - Rare earth phosphate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Rare earth phosphate (generic). 721... Substances § 721.6005 Rare earth phosphate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as rare earth phophate (PMNs...

  8. 40 CFR 721.6005 - Rare earth phosphate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Rare earth phosphate (generic). 721... Substances § 721.6005 Rare earth phosphate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as rare earth phophate (PMNs...

  9. 40 CFR 721.6005 - Rare earth phosphate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Rare earth phosphate (generic). 721... Substances § 721.6005 Rare earth phosphate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as rare earth phophate (PMNs...

  10. BIOLOGICAL ELECTRODES SPECIFIC FOR PHOSPHATE AND NITRITE IONS

    EPA Science Inventory

    Biological electrodes have been developed for the selective analysis of phosphate and nitrate ions at micro-levels. A phosphate electrode was constructed by using two enzymes, alkaline phosphatase and glucose oxidase which were immobilized and mounted on the surface of the Platin...

  11. 40 CFR 721.5980 - Dialkyl phosphorodithioate phosphate compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... compounds. 721.5980 Section 721.5980 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.5980 Dialkyl phosphorodithioate phosphate compounds. (a) Chemical... as dialkyl phosphorodithioate phosphate compounds (P-90-1642 through 1649) are subject to...

  12. 40 CFR 721.5980 - Dialkyl phosphorodithioate phosphate compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... compounds. 721.5980 Section 721.5980 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.5980 Dialkyl phosphorodithioate phosphate compounds. (a) Chemical... as dialkyl phosphorodithioate phosphate compounds (P-90-1642 through 1649) are subject to...

  13. 40 CFR 721.5980 - Dialkyl phosphorodithioate phosphate compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... compounds. 721.5980 Section 721.5980 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.5980 Dialkyl phosphorodithioate phosphate compounds. (a) Chemical... as dialkyl phosphorodithioate phosphate compounds (P-90-1642 through 1649) are subject to...

  14. 40 CFR 721.5980 - Dialkyl phosphorodithioate phosphate compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... compounds. 721.5980 Section 721.5980 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.5980 Dialkyl phosphorodithioate phosphate compounds. (a) Chemical... as dialkyl phosphorodithioate phosphate compounds (P-90-1642 through 1649) are subject to...

  15. 40 CFR 721.5980 - Dialkyl phosphorodithioate phosphate compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... compounds. 721.5980 Section 721.5980 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.5980 Dialkyl phosphorodithioate phosphate compounds. (a) Chemical... as dialkyl phosphorodithioate phosphate compounds (P-90-1642 through 1649) are subject to...

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

    PubMed

    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. PMID:25161314

  17. Chemistry Misconceptions Associated with Understanding Calcium and Phosphate Homeostasis

    ERIC Educational Resources Information Center

    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…

  18. 40 CFR 721.10436 - Amine neutralized phosphated polyesters (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... polyesters (generic). 721.10436 Section 721.10436 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10436 Amine neutralized phosphated polyesters (generic). (a) Chemical... as amine neutralized phosphated polyesters (PMN P-99-1217 and P-99-1218) are subject to...

  19. 40 CFR 721.10436 - Amine neutralized phosphated polyesters (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... polyesters (generic). 721.10436 Section 721.10436 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10436 Amine neutralized phosphated polyesters (generic). (a) Chemical... as amine neutralized phosphated polyesters (PMN P-99-1217 and P-99-1218) are subject to...

  20. Sodium-Dependent Phosphate Transporters in Osteoclast Differentiation and Function

    PubMed Central

    Dolder, Silvia; Siegrist, Mark; Wagner, Carsten A.; Biber, Jürg; Hernando, Nati; Hofstetter, Willy

    2015-01-01

    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. PMID:25910236